042753   DANISH P, ASHRAF P M , GANESH S , ANITA JESSIE J , SEIN W (Civil Engineering Dep, Model Institute of Engineering and Technology, Jammu, Email: danish.civ@mietjammu.in) : Performance evaluation of students using online courses. Indian J Sci Technol 2020, 13(13), 1440–9.

The present study was aimed to find the effective method to assess the performance of students and their interest towards e-learning. Questionnaire survey was conducted among Indian students and their response were identified on various aspects; assessment, interaction, evaluation and feedback. The responses were collected and the data were analyzed with statistical software. Interaction and evaluation aspects had high impact; signifying 40 % of the students agree that online learning is more effective, innovative and convenient than the conventional way of learning. Assessment and interaction showed the highest positive correlation (0.564) when compared to the evaluation and feedback (0.440). The evaluation has attained significant value in the statistical analysis of ANOVA.

7 illus, 2 tables, 37 ref

042746   ASWATHA R, SEETHALAKSHMI V , MURUGAN K , SATHISHKUMAR N , REETHIKA A , GUNANANDHINI S (Electronics and Communication Engineering Dep, Institute of Engineering and Technology, Coimbatore - 641 407, Email: aswathajrkrishnan@gmail.com) : Implementation of cooperative spectrum sensing using cognitive radio testbed. Indian J Sci Technol 2020, 13(13), 1355–66.

To implement energy detection and eigenvalue based cooperative spectrum sensing in NI-USRP hardware platform and to obtain its performance.Cooperative spectrum sensing is to be implemented using OR and AND fusion rules. The hardware is implemented using one primary user transmitter and two cognitive radio users. The implementation is done using LABVIEW and detection performance is analyzed. In cooperative spectrum sensing (CSS), CR system shares its own sensing information with other sensing nodes and utilizes the sensing outcomes of others to give a decision. Energy detection performs well in high SNR region and eigenvalue based detection performs well even with low SNR region. Energy detector detects the signal completely with SNR greater than 10dB. Eigenvalue detector detects signal completely at SNR of -9dB. Detection probability with OR Cooperative rule is better than AND rule. It increases with number of samples and signal-to-noise ratio. It is found that cooperative spectrum sensing performs well than the noncooperative sensing by decreasing the chances of miss detection. CSS is robust in sensing errors due to hidden node or fading channels and also it decreases the probabilities of false alarm as well as probabilities of miss detection.

9 illus, 18 ref

042743   SIVASWAMY S, SAMBANDAN S , RAMASAMY P , SURIANARAYANAN M (Environmental Health Engineering Dep, Sri Ramachandra Institute of Higher Education and Research (Deemed to be Univ), Porur - 600 116, Chennai) : Prevalence and risk factors associated with wheezing among children and adolescents from Chennai, South India. Indian J Sci Technol 2020, 13(12), 1342–6.

To investigate the prevalence and associated risk factors that influence wheezing and asthma in children and adolescents. A total of 135 male children and adolescents were selected from various schools. Information about family history, dietary pattern, respiratory symptoms and environmental risk factors were obtained using questionnaire survey. The prevalence of wheezing in the past 12 months was 31.85 %. The prevalence of asthma was 2.2 %. Consumption of fast food, overweight and obesity and exposure to traffic fumes were observed to be important risk factors with increased risk among the children. The impact of environmental factors such as air pollution must be quantitatively established with exposure assessments supplemented with questionnaire surveys to reduce the burden of disease. This study provides a cross-sectional outlook on modifiable risk factors that can be targeted to reduce the impact of asthma and wheezing in children.

3 tables, 20 ref

042740   SIVASWAMY S, SAMBANDAN S , PUTTUSAMY N , RAMASAMY P , SURIANARAYANAN M , SAIDAM S R (Environmental Health Engineering Dep, Sri Ramachandra Institute of Higher Education and Research, Porur - 600 116, Chennai, Email: samantha_1412@yahoo.com) : Urinary 1-Hydroxypyrene levels among children with asthma in Chennai, South India. Indian J Sci Technol 2020, 13(12), 1316–20.

To explore the potential relationship between exposure to Polycyclic Aromatic Hydrocarbons (PAHs) and asthma exacerbation among children and also to explore the potential exposure sources of PAHs at the household level. Case-control study was conducted at a tertiary care hospital in Chennai among 60 participants after obtaining approval from the Institutional Ethics Committee. The study was conducted from March till May 2018. Informed consent was obtained from the participants. The participants were included based on their clinical diagnosis of asthma and few participants were as used as control based on no documented history of wheeze and PEFR levels. All the participants were male children aged between 9-12 years and exclusion was done if they were reported to having congenital heart disease, surgery or chronic lung disease. They were interviewed with a standardized questionnaire to ascertain their exposure to PAHs sources. Urinary 1-OHP levels were analyzed using HPLC to determine their exposure. Participants with asthma showed a higher concentration of 1-OHP (7.56µg/g) in their urine. Second hand exposure to tobacco smoke, consumption of charred or grilled foods, use of indoor air pollutants and exposure to traffic fumes were identified as contributive factors to elevated 1-OHP levels. Exposure sources at household levels may play a major role in exacerbating asthma. Significant PAHs exposure was contributed through dietary habits. Further exposure monitoring studies are needed to quantify the impact of PAH exposure on respiratory health.

2 illus, 2 tables, 18 ref

042738   SOWPARNIKA G C, THIRUMARIMURUGAN M , VINOTH N (Biomedical Engineering Dep, Sri Shakthi Institute of Engineering and Technology, Coimbatore - 641 062, Tamil Nadu, Email: csowparnikabm@siet.ac.in) : Modeling and optimized controller for cardiac drug infusion system. Indian J Sci Technol 2020, 13(12), 1347–54.

Manual drug infusion during surgeries is inaccurate and timeconsuming which has been adopted technique in most of the hospitals. Based on clinical data, it is evident that the manual control is inaccurate and takes prolonged time to bring into effect, if any change in infusion rate is required during clinical practice. Considering this drawback, the modeling of cardiovascular system (CVS) and baroreceptor (BR) is developed using miscellaneous differential equations based on compartmental approach. The control variables are mean arterial pressure (MAP) and cardiac output (CO) obtained from CVS-BR model. The manipulated variables are noradrenaline (NAR) and nitroglycerine (NG) infusion rate which is modeled using the relationship between volume and drug mass effect equations on CVS-BR model. For the open loop transfer function derived from the model, relative gain array (RGA) analysis is performed to identify the influence of maximum effect of manipulated variables on the physiological parameters. The simulation results obtained from MATLAB are correlated using time domain specifications and error criteria. The performance index reveals the least error and facilitates in accurate infusion of drugs to the patient during cardiovascular surgeries. The automatic controller during surgery provides safe operating condition and speedy recovery of the patients and also helps the anaesthetist to monitor and regulate the physiological variables.

5 illus, 3 tables, 18 ref

042725   TUPE D H, DAHAKE A G, GANDHE G R (Civil Engineering Dep, PES Coll of Engineering, Aurangabad, MS 431005) : Static examination of simply supported laminated composite beam with varying load using trigonometric shear deformation theory. Indian J Sci Technol 2020, 13(10), 1188 – 99.

To study the trigonometric shear deformation theory for the evolution of displacements and stresses of crossply simply supported laminated beam subjected to varying load. A trigonometric shear deformation is used. The inplain displacement field uses a sinusoidal function in terms of the thickness coordinate to include the shear deformation effect. The theory satisfies the shear stress free boundary conditions on the top and bottom surfaces of the plate. The present theory obviates the need of a shear correction factor. Governing equations and boundary conditions of the theory are obtained using the principle of virtual work. Stresses and displacements for orthotropic, single-layer, three-layer symmetric square cross-ply laminated beam subjected to varying load. The numerical results of the present theory for displacement and stresses are compared with those of classical (ETB), first-order (FSDT), and higher-order shear deformation beam theories.

2 illus, 1 tables, 12 ref

040952   GHOSH P, GHOSH U (Food Technology & Biochemical Engineering Dep, Jadavpur Univ, Kolkata - 700 032, West Bengal, Email: ughoshftbe@yahoo.co.in) : Statistical optimisation of laccase production by isolated strain Aspergillus flavus PUF5 utilising ribbed gourd peels as the substrate and enzyme application on apple juice clarification. Indian Chem Eng 2020, 62(4), 427–38.

In the current study laccase was produced by the isolated strain Aspergillus flavus PUF5 through solid-state fermentation (SSF) using waste ribbed gourd peels as substrate. During the statistical optimisation process, influencing fermentation factors among eleven selected variables were identified using Plackett–Burman design. Among them, fermentation time (144–192 h), medium pH (3.0–7.0), concentration of starch (0.5–1 %) and concentration of peptone (0.2–0.8 %) were vital influencing parameters. Furthermore, the shared effects of those variables were studied following Box–Behnken design. Optimised states of selected variables were fermentation time (168 h), medium pH (4.9), concentration of starch (0.61 %) and peptone (0.51 %) with predicted and observed activity of laccase 174.3 and 168.9 U/g, respectively. This laccase production under optimised condition was about 3.5-fold more that the unoptimised medium. The laccase obtained through SSF was tested for its suitability in the clarification of apple juice. During enzymatic oxidation, the changes in colour, turbidity, phenolics and flavonoids in apple juice were estimated and compared with untreated sample. Results showed a significant reduction in phenolic and flavonoid content in the fruit juice during the oxidation process. The turbidity in the juice was also decreased, which indicated the suitability of the laccase form A. flavus PUF5 in fruit juice clarification.

5 illus, 3 tables, 27 ref

040950   PONMANI S, GUPTA P, JADHAWAR P, NAGARAJAN R, SANGWAI J (Ocean Engineering Dep, Indian Institute of Technology Madras, Chennai - 600 036, Tamilnadu, Email: jitendrasangwai@iitm.ac.in) : Investigations on the thermal and electrical conductivity of polyethylene glycol-based CuO and ZnO nanofluids. Indian Chem Eng 2020, 62(4), 402–12.

In this experimental work, three different types of nanofluids were evaluated for their stability using dynamic light scattering and particle morphological study using scanning electron microscopy. The nanofluids used in this study are zinc oxide (ZnO) nanoparticle in water and 5 wt % polyvinylpyrrolidone (PVP) as a dispersant, and ZnO with polyethylene glycol (PEG 600) and CuO with PEG 600 with 5 wt % PVP at different concentration of 0.1, 0.3 and 0.5 wt %. Thermal and electrical conductivities were determined by KD-2 Pro® and PC 700 Eutech®. The result shows better enhancement in the thermal and electrical conductivity in the ZnO+PVP+Water system, followed by the CuO+PVP +PEG and ZnO+PEG systems. The highest percentage enhancement in thermal conductivity found to be 35.5 % of ZnO+ PVP+water systems. The thermal conductivity results were compared with a theoretical model and show good agreement with results predicted by the model. The proposed model of Nan et al. (1997) is based on a hypothesis regarding the physical mechanism in heat transfer for nanofluids. This study is expected to form the basis for the development of nanofluidbased technologies with PEG as the primary additive in the upstream oil and gas industry especially in gas hydrates and drilling technology.

6 illus, 3 tables, 32 ref

040946   SHUKLA H K, BARSHILIA H, SUNIL S, PORKODI P, GHOSH P, VIJU, KAMALESHAIAH M S, JADHAV J J (CSIR-NAL, Bengaluru, Karnataka - 560 017, Email: hemant@nal.res.in ) : Development of indigenous personal protective equipment coverall by CSIR-NAL. Indian Chem-Sect A 2020, 62(4), 367–73.

Personal protective equipment (PPE) Coverall is an essential protective garment for frontline healthcare workers involved in mitigation of COVID-19. Comfort and safety are the prime theme of design and development of coverall. The fabric selection, stitching and seam sealing are the major challenges in the development of PPE coverall. The technical information along with qualification/approval procedure involved in the manufacturing of PPE coverall is described in this article.

5 illus, 2 tables, 5 ref

042717   GILANI E, SOOMRO M A, ALI T, SAHITO A A, BULLER A S (Civil Engineering Dep, Quaid-e-Awam Univ, Sindh, 67450, Pakistan, Email: eramgilani1995@ gmail.com ) : Effect of stress relief on pile capacity in soft clay. Indian J Sci Technol 2020, 13(9), 1089 – 97.

Pile load test is commonly carried out at ground level assuming that using sleeve eliminates shaft resistance within the planned excavation area. But these tests do not capture the effect of stress relief due to excavation. So to study its effect on pile behavior, three numerical simulations were carried out using finite element method. The first simulation (L_Ground) was carried out at the ground level. The second simulation (L_Sleeve) was conducted using sleeve in the planned excavation area. The length of sleeve was taken equal to the depth of basement. The third simulation (L_ Excavation) was carried out after excavation at the formation level. It was found that Q_LE is 85 % of Q_LS so when tests are conducted by using sleeve, pile capacity is over estimated. Q_LG is 74 % of Q_LS which is less than Q_LE. Because after excavation, soil particles around the pile are stiffer so capacity is increased. At ground level, at working load shaft carries about 77 % load. When the load is increased and reaches the ultimate value end bearing contributes more than the shaft resistance. On the other hand, for sleeved pile, at working load shaft and end bearing carries about 80 and 20 % load, respectively. But at ultimate load, shaft carries 55 % load which is still greater than that carried by end bearing. While after excavation, at working load shaft carries about 86 % load. When ultimate load is reached the load distribution is similar to sleeved pile. In the case of ground level and excavation, the shaft resistance has been fully mobilized at the load less than Q_LS that is about 74 and 86 % of Q_LS, respectively. These results will help to estimate the pile capacity in a better way.

5 illus, 2 tables, 14 ref

040938   SANCHEZ G, APERADOR W, CERÓN A (Militar Nueva Granada Univ, Bogotá, Colombia, Email: alexander.ceron@unimilitar.edu.co) : Corrosion grade classification: A machine learning approach. Indian Chem Eng 2020, 62(3), 277–86.

Corrosion tests allow to have information to indicate the state of materials in certain applications when environmental specifications are not met. It allows developing new material coatings to improve resistance to degradation. The area of materials inspection has relevance in construction, manufacture and medicine. In this work, we present an image corrosion classification method based on visual features and SVM (support vector machine). The feature extraction procedure includes SIFT (scale invariant transform features) and BOW (bag of words) approaches. The performance of classifiers is compared over the kernel function and the involved parameters. The experimental methodology known as the Tafel extrapolation method performed on each corrosion sample to find the corrosion rate and the corrosion current and voltage. A comparison between the Tafel test and the developed vision-based approach allows to see the high potential of the developed process to differentiate between pitting and general corrosion.

4 illus, 4 tables, 22 ref

040935   ADENIYI A G, IGHALO J O, ODETOYE T E (Chemical Engineering Dep, Ilorin Univ, Ilorin P. M. B. 1515, Nigeria) : Response surface modelling and optimisation of biodiesel production from Avocado plant (Persea americana) oil. Indian Chem Eng 2020, 62(3), 243–50.

Avocado (Persea americana) is a plant native to tropical America but available in most other tropical areas of the world. In comparison to other fruits, the avocado contains a significant amount of oils which are highly rich in fatty acids. This study considered the response surface modelling and optimisation of the production of biodiesel from Avocado plant (P. americana) oil using methanol and NaOH catalyst. The basis of this work was a reliable dataset already presented in the open literature. An empirical correlation was developed from the available dataset to predict the biodiesel yield of Avocado plant (P. americana) oil based on known levels of the key process parameters and an ANOVA showed it to be significant. It was also observed that temperature, methanol–oil ratio and time are the more significant process factors. Numerical optimisation revealed that the optimal values of the factors are 61.63°C temperature, methanol–oil ratio of 7.21 mol/mol, catalyst loading of 1.15 %w/w and process time of 88.61 min to give a predicted optimal biodiesel yield of 97.32 %.

3 illus, 4 tables, 17 ref

040933   KOSHTA N R, BHANVASE B A, CHAWHAN S S, BARAIA D P, SONAWANE S H (Chemical Engineering Dep, RTM Nagpur Univ, Nagpur, Maharashtra - 440 033) : Investigation on the thermal conductivity and convective heat transfer enhancement in helical coiled heat exchanger using ultrasonically prepared rGO–TiO₂ nanocomposite-based nanofluids. Indian Chem Eng 2020, 62(2), 202–15.

This work deals with sonochemical synthesis of finely dispersed reduced graphene oxide–TiO₂ (rGO/TiO₂) nanocomposites with successful immobilisation of TiO₂ nanoparticles on rGO. Structural and morphological analysis of prepared rGO/TiO₂ nanocomposite was done with the use of UV/VIS, TEM, XRD and FTIR analysis that confirms the formation of finely dispersed rGO/TiO₂ nanocomposite. A helical coiled heat exchanger was used for examining convective heat transfer enhancement exhibited by the prepared rGO/TiO₂ nanocomposite-based nanofluid. Thermal conductivity enhancement of rGO/TiO₂ nanocomposite-based nanofluids with the nanocomposite loading of 0.1–0.5 volume % in water was investigated. An investigation on improvement in the heat transfer coefficient was carried out at different loading of rGO/TiO₂ nanocomposite in base fluid at various Reynolds number values. Percentage enhancement in the heat transfer coefficient was around 35.7 % for 0.25 volume % concentration of rGO/TiO₂ nanocomposite in base fluid.

7 illus, 1 table, 46 ref

040932   RANGANAYAKULU R, RAO A S, BABU G U B (Chemical Engineering Dep, National Institute of Technology, Warangal - 506 004) : Improved fractional filter IMC–PID controller design for enhanced performance of integrating plus time delay processes. Indian Chem Eng 2020, 62(2), 184–201.

In this paper, an improved fractional filter IMC–PID controller was proposed to enhance the performance of integrating processes after identifying the optimum higher order fractional IMC filter structure. The identification involves a systematic procedure based on the minimisation of integral absolute error (IAE). The present design also considers different approximations for time delay. The tuning parameters are obtained based on the prefixed robustness (maximum sensitivity, M_s). The present method is compared with recent methods in the literature and its superiority is demonstrated with performance measures IAE and total variation (TV). Enhanced output performance is obtained for nominal process conditions; for process parameter variations and for noise in the measurement. Robustness analysis is performed using complementary sensitivity function and parametric uncertainty bounds. Also, the fragility analysis is carried out to check the sensitivity of closed loop system for variation in controller parameters.

6 illus, 4 tables, 27 ref

042707   MEMON M A, BHUTTO G M (Electrical Engineering Dep, Quaid-e-Awam Univ of Engineering Science and Technology, Pakistan 67480, Email: engr. mam@quest.edu.pk ) : Effect of optimum sized solar pv inverter on energy injected to ac grid and energy loss in Pakistan. Indian J Sci Technol 2020, 13(8), 954 – 65.

To analyze the effect of optimized size inverter for Nawabshah Sindh Pakistan on the annual energy injected to ac grid and energy loss. Using the optimized sizing ratio of 1.4664, which is the ratio of rated photovoltaic system to the rated inverter size the simulations are carried out in MATLAB for 3 kW and 50 kW photovoltaic systems. A comparison between the conventional sized system that is the photovoltaic system and inverter of the same size and optimized system where the photovoltaic inverter is connected with respect to the sizing ratio are taken and simulations are carried out using real time data of solar irradiation and ambient temperature of Nawabshah Sindh Pakistan in MATLAB for one year. It is seen that 5830 kWh and 97,162 kWh energy is annually injected to the utility grid or load and annual power loss of 274 kWh and 4568 kWh from conventional sized 3 kW and 50 kW PV systems, respectively. While the annual energy injected to the ac grid is 5852 kWh and 97,529 kWh and annual power loss of 252 kWh and 4201 kWh from optimized sized 3 kW and 50 kW PV systems, respectively. Thus, we can say that the optimized system not only reduces the size of the inverter but also improves the system efficiency and reduces the losses which eventually decreases the capital cost of the PV system and energy production.

8 illus, 5 tables, 26 ref

042706   ÖRNEK A, ESNAF S (Industrial Engineering Dep, stanbul Univ-Cerrahpa?a, Kampusu, Istanbul, Turkey, Email: ali.ornek@ogr.iu.edu.tr) : Revenue management focused capacitated vehicle routing model in supply chain management. Indian J Sci Technol 2020, 13(8), 941 – 53.

To propose revenue management focused model for Capacitated Vehicle Routing Problem with Simultaneous Pickup and Delivery and pursue a solution to it. In some industries, customer demand for delivery and pickup fluctuates and the vehicle capacities are limited. Existing research focuses on either Revenue Maximization or Transportation Cost Minimization. To be able to run such businesses profitably, it is necessary to consider both objectives by the help of the proposed model. Dynamic pricing will be used for revenue maximization, by booking early reservations for a lower price. Vehicle Routing Problem will determine the route to minimize the total transportation cost. The capacitated vehicle routing model with simultaneous pickup and delivery is combined with a revenue management model in which low price early reservations are allowed. In case the customer orders cannot be handled with existing vehicle capacities, some of the early reservation orders are canceled and a cancellation fee is incurred. The model is solved with a mixed-integer linear programming (MILP) solver. The proposed model is tested against a real-world data set. The result shows that unprofitable customer orders are determined by the model and rejected despite there is a cancellation fee. By applying the revenue management model, it is observed that there is an increase in the total profit. To the best of our knowledge, this study proposed a revenue management focused MILP model for VRP with simultaneous pickup and delivery for the first time.

4 tables, 19 ref

042705   HIDAYANTI F (Engineering Physics Dep, Nasional Univ, Jalan Sawo Manila No. 61, Jakarta 12520, Indonesia, Email: fitriahidayanti@ gmail.com) : Design an internet of things simulator of fluid volume monitoring system for petrol station underground tank. Indian J Sci Technol 2020, 13(8), 934 – 40.

This study aims to design an internet of things simulator of fluid volume monitoring system. The method used in this research includes simulator design and simulator testing. Monitoring system using an ultrasonic sensor, nodeMCU, ThingSpeak, and Virtuino. The value of ultrasonic sensors will be processed in the NodeMCU program resulting liquid level in the buried tank then sent through the internet to ThingSpeak. The result of monitoring the liquid level in a buried petrol station simulator uses ultrasonic sensor HCSR04P and NodeMCU v.1.0 from 08.00 pm to 02.00 am displayed on the site ThingSpeak with value 17.42 L.Setting alarm on Virtuino at 50 % of maximum volume of 8.8 L. The experimental results the volume of fluid reduction 8.09 L has managed to activate alarm on the application Virtuino. This internet of things simulator of fluid volume monitoring system applicated for the petrol station underground tank.

4 illus, 8 tables, 12 ref

042702   YITAYIH K A (Electrical and Electronic Engineering Dep, Federal Univ of Technology, Owerri, Imo State, Nigeria, Email: kebebew. ababu@ju.edu.et ) : Adaptive group-based qos aware link state proactive multipath routing for large-scale MANETs (GMP-OLSR). Indian J Sci Technol 2020, 13(8), 893 – 906.

To propose a group-based QoS aware proactive multipath routing based on OLSR protocol. This work proposes a group-based proactive multipath routing based on the OLSR protocol, which is designed to be adaptive for a big crowded Mobile Ad-hoc Network to satisfy the desire for real-time multimedia applications. This approach will restrict mobile nodes to be participated in the cluster head selection process based on the mobility and energy of a node. It uses a grouping strategy to manage the network topology and performing route maintenance, and preserve multiple prioritized routes with the support of Quality of Service (QoS) aware computation. The study evaluated the performance of the proposed group-based QoS aware multipath Optimal Link State Routing (GMP-OLSR) routing through the OMNET++ network simulation environment. Within different network density, the proposed approach offered a significant reduction in end to end delay, overhead and an increment in data packet delivery ratio. Using an appropriate groupbased QoS aware multipath routing strategy for mobile ad hoc networks provides better performance and improves the services of mobile applications.

7 illus, 2 tables, 18 ref

040930   GUPTA K N (Chemical Engineering Dep, Jaypee Univ of Engineering & Technology, Guna - 473226, Madhya Pradesh) : Modelling, simulation, and experimental validation for toluene removal from gas phase in a fixed bed adsorption column. Indian Chem Eng 2020, 62(2), 150–69.

In this study, an adsorption technique was explored for the removal of toluene present in the gas phase by taking granular activated carbon as an adsorbent in a fixed bed adsorption column. Breakthrough curves were experimentally found out at varying bed height (0.015–0.025 m) and inlet concentration (7000–11500 ppm). Modelling and simulation studies were subsequently carried out to enable the comparison between predicted and experimental breakthrough curves. Here orthogonal collocation technique was employed to solve the model equations by discretising non-linear coupled partial differential equations into set of ordinary differential equations which were solved by using ODE15s solver of Matlab. The discretisation procedure has been described in detail. Finally, the flow rate was found out to be the most sensitive parameter after carrying out sensitivity analysis.

9 illus, 7 tables, 35 ref

042699   ONUEKWUSI NNAEMEKA C, NWABUDE GERALDINE C, OKOZI SAMUEL O, EZEMA LONGINUS S (Electrical and Electronics Engineering Dep, Federal Univ of Technology, Owerri, Imo State, Nigeria, Email: nnaemeka. onuekwusi@futo.edu.ng ) : An Integrated presence detection sensor and android mobile application system for energy management and control. Indian J Sci Technol 2020, 13(7), 860 – 9.

It is a common responsibility for individuals and organizations to effectively manage energy in buildings for economic and environmental concerns. In this study, the development of an energy management system integrated with a presence detecting sensor and an android mobile application for remote control of electrical appliances is undertaken. The integrated system is basically composed of a human presence detecting Passive Infrared (PIR) sensor mounted on a WeMos D1 microcontroller and remotely monitored and controlled from a web server using an android mobile application via a wireless network. The developed system provides multiple benefits. It eliminates human involvement and manpower often required to manually toggle power outlets and appliances on/off. Furthermore, it conserves electrical energy and prevents wastages by ensuring that energy is only consumed when needed. The developed system is recommended for residential and small office applications.

10 illus, 1 table, 14 ref

040928   NAIK R H, KUMAR D V A, RAO P V G (RGM Coll of Engineering and Technology, Nandyala, Andhra Pradesh - 518 501) : Improved centralised control system for rejection of loop interaction in coupled tank system. Indian Chem Eng 2020, 62(2), 118–37.

In practice, majority of the processes are multivariable in nature and control of these processes is very intricate, due to the presence of nonzero diagonal elements in the system. This problem is addressed in the paper with the proposal of a centralised PI controller for controlling the interactive Two Input and Two Output processes. The proposed controller includes a diagonal PI controller and a decoupler element in off diagonal. To design PI controller, a well-known SISO tuning technique SIMC is considered and decoupler elements of off diagonal are designed using coefficient matching principle. The main diagonal controller improves the system performance, while the decoupler rejects the interaction; this improves the overall system. The designed controller performance is evaluated practically on a coupled tank system. The designed control system performance for both servo and regulatory operation is studied. The robustness analysis of the proposed method was analysed using inverse maximum singular value versus frequency plot by incorporating the multiplicative uncertainty in both input and output of the system.

17 illus, 5 tables, 26 ref

040927   MAHMOOD L H, ABID M F (Chemical Engineering Dep, Technology Univ, Baghdad, Iraq) : Dmetallization of Iraqi Crude oil by using zeolite a. Indian Chem Eng 2020, 62(1), 92–102.

In present work, the removal of vanadium (V) from Iraqi crude oil using zeolite A was investigated. Different operating parameters such as adsorbent loading, vanadium loading, and operating time were studied for their effects on metal removal efficiency. Results of the adsorption test showed that the Langmuir isotherm predicted well the experimental data and the maximum zeolite A uptake was 30 mg V/1 g zeolite. XRD, SEM, and EDX analyses revealed the noticeable uptake of zeolite for V. In crude oil, experimental results indicated that for zeolite loading at 1 g/100 mL oil and within approximately 5 h, the removal efficiencies of V were 60, 45, and 33 % at vanadium loadings of 75, 85, and 95 ppm respectively. While at 10, 20, 40, and 50 h the removal efficiency was 68, 75, 78 and 78 % at 75 ppm of vanadium loading. At vanadium loading of 75 ppm, the equilibrium concentration of V in crude oil was obtained after 40 h of operation. Long-term tests revealed the high stability of zeolite A for vanadium removal. Experimental results depicted that zeolite A could be advantageous for the removal of V in the crude oil hydrotreating units.

8 illus, 2 tables, 27 ref

040925   REDDY S N, CHIDAMBARAM M (Chemical Engineering Dep, National Institute of Technology Warangal, Warangal - 506 004) : Model identification of critically damped second order plus time delay systems. Indian Chem Eng 2020, 62(1), 67–77.

In the present work, a simple method is proposed to calculate the parameters of a critically damped second-order transfer function model [k_Pexp(−Ls)/(ts + 1)²] from the fractional step response of higher order systems. Five simulation examples are given to show the simplicity of the proposed method. The method makes use of a unique property of a critically damped second order plus time delay system (Harriott, Process Control, McGraw Hill, New Delhi), that, a time of 2.58τ is required to reach a fractional step response of 0.73. The time required to reach 0.35 (or any value) of fractional step response is also required. The derivation of the equations for the model parameters is simpler than that proposed by Rangaiah and Krishnaswamy (Ind. Engg. Chemistry Research, V 33, 1994, 1867–1871). The ISE and IAE values for the present method are compared with that of Rangaiah and Krishnaswamy. The method is also modified to get the model parameters of a FOPTD system: [k_Pexp(−Ls)/(ts + 1)].

11 illus, 5 tables, 10 ref

040924   OGUNLEYEA O O, ARINKOOLAA A O, ALAGBEA S O, AGBEDEA O O, OMODELEC A E, MORAKINYOA A F, OSHOA Y A (Chemical Engineering Dep, Ladoke Akintola Univ of Technology, Ogbomoso PMB 4000, Nigeria) : Synthesis of green corrosion inhibitor for mild steel in acidic environment. Indian Chem Eng 2020, 62(1), 52–66.

The inhibitive potential of Mondia whittei roots extract (MWE) on corrosion of Mild Steel coupons in 0.5 M HCl solution was investigated by weight loss, depth of attack and surface analysis. Effect of various parameters, such as concentration of MWE, immersion time and temperature on inhibition efficiency was studied. The identification of the constituents of MWE and characteristics of the test solution and adsorbed film on the test coupon were evaluated by Gas Chromatography/Mass Spectrophotometer (GC-MS) and Fourier Transform Infra-Red (FTIR) Spectrophotometer. The surface morphology and topographical features of the corroded mild steels were done by the scanning electron microscope (SEM). The main constituents responsible for corrosion inhibition properties of MS were found to be guaiacol, vanillin, 9, 12- octadecadienoic acid and phenol, 2, 6-dimethoxyl among many other components which contain C, H and O. A maximum corrosion inhibition efficiency of 89.47 % was obtained with 1.0 g/L in 0.5M HCl at 60°C after 9 h and volume – area ratio of 40 mL/cm² . Polarisation curves reveal that the inhibition efficiency according to depth of attack given by R_a and R_z increased with increasing inhibitor concentration, temperature, time and volume – area ratio.

6 illus, 6 tables, 47 ref

042687   TIWARI G, CHAUHAN R C S (Electronics Engineering Dep, Institute of Engineering & Technology, Lucknow, Email: gayatri.10nov@ gmail.com ) : A review on inter-satellite links free space optical communication. Indian J Sci Technol 2020, 13(6), 712 – 24.

The need for constricting, lightweight, low-power electronics-aggravated by the thriving demand for large data flow rate and bandwidth is urging the use of optical technologies in defense and space. Free space optical (FSO) communication links have promising eminence over microwave communication links with high speed, low weight, and increased security so that they can be boarded conveniently on the satellite. The advancement of the optical components and systems has made it very predominant along with its acceptability in space and defense. Yet a couple of significant components to be dealt with are tracking problems with misalignment of the transmitter and receiver apertures and the progressions because of barometrical conditions. Efficiency of the FSO communication system is seriously rotted due to the angle of arrival (AoA) variance and including error pointing. The optical transmitter can be perfectly coordinated with the receiver by utilizing the pointing, acquisition, and tracking (PAT). However, this method is to be carried out under the airborne platform with required restrictions namely size, weight, and power. An overview of promising inter-satellite applications with the challenges have been discussed which sway the performance of the system and make the communication link unattainable. The FSO communication possesses an advantage over two existing technologies optical fiber communication and wireless communication. Hence, the significant use of FSO is intersatellite optical wireless communication (Is OWC) links, which will be deployed in the future in space.

5 illus, 1 table, 45 ref

042686   ESPINOSA F H T (Industrial Engineering Dep, del Bío-Bío Univ, Concepción 4030000, Chile, Email: ftroncos@ubiobio.cl ) : Prediction of recidivism in thefts and burglaries using machine learning. Indian J Sci Technol 2020, 13(6), 696 – 711.

Theft and burglary are two crimes against property that have a great social impact. Their prevention drastically lowers victimization rates and the feeling of insecurity in the population. The objective of this investigation is to obtain an index that allows the prediction of repeat offenses by criminals in these types of crimes, in order to support decision-making with respect to preventative actions. In order to obtain the index, a group of machines learning was trained, with information provided by the Criminal Analysis and Investigative Focus System (CAIFS) from the Regional Public Prosecutor’s Office in Biobío, Chile. The information provided was from thefts and burglaries committed between 2012 and 2017 in the city of Concepción. The results show a characterization of repeat offenders in these types of crime and a recurrence index that allows for a greater assertiveness in the prediction of recidivism than the method that is currently being used.

3 illus, 6 tables, 41 ref

042681   MAHESAR M R, MAHA M AR, LARIK A S, SOLANGI M H (Electrical Engineering Dep, Mehran Univ of Engineering Technology Jamshoro, Pakistan, Email: mahesar85@gmail.com D) : Comparative analysis of three-phase single active bridge dc-dc converter with different mode of conduction with transformer vector groups. Indian J Sci Technol 2020, 13(6), 630 – 45.

This research study compares the performance of a three-phase single active bridge DC-DC converter with several operating modes along with vector groups in order to present the importance and applications of transformer vector groups in the electrical network system. In order to analyze and compare the operating characteristics of three-phase single active bridge converter with vector groups of transformer. Initially, we made a detailed study of vector groups of transformers through literature review. Then the development of simulation model of three-phase single active bridge DC-DC converter with transformer vector groups while operating with different operating modes of three-phase inverter by using MATLAB/SIMULINK software was made. We investigated Total Harmonic Distortion (THD) in terms of voltage and current waveforms with both resistive and inductive load of SAB3 converter with the different transformer vector group while operating with different modes of conduction, i.e., 120, 150, and 180. Undoubtedly, today’s world is moving towards replacing fossil fuels with renewable energy resources. Three-phase single active bridge DC-DC converters are widely advantageous. From the simulated results, it is clear that at 150-operating mode, the SAB3 generated fewer harmonics in terms of voltage and current for both resistive and inductive load as compared to other operating modes.

18 illus, 7 tables, 17 ref

042679   KHAN A N, BHEEL N, AHMED M, ABBASI R A, SOHU S (Civil Engineering Dep, H.C.S.T Hyderabad, Sindh, Pakistan, Email: udasinarain@ gmail.com ) : Use of styrene butadiene rubber (SBR) polymer in cement concrete. Indian J Sci Technol 2020, 13(5), 606 – 16.

This research work was adopted to have the maximum strength of concrete mixed with styrene-butadiene rubber (SBR) and to know the effect of SBR on the fresh and hardened concrete. The concrete samples were prepared to achieve targeted strength of 3000 lb/in². In this experimental work, the mixture of concrete was prepared by adding 0 %, 5 %, 10 %, 15 %, and 20 % of SBR polymer–cement ratio to check the properties of fresh concrete (slump test and compaction factor test), while rebound hammer test, ultrasonic pulse velocity test (UPV), compressive strength test, and tensile strength test were observed at 7th, 14th, and 28th days, respectively. Resultantly, the compressive strength and indirect tensile strength boosted by 16 % and 13 % blended with 15 % of SBR polymer in concrete as compared to control concrete after 28th days, respectively. The workability of fresh concrete plummeted with a rise in the amount of SBR polymer in concrete. Both the quality and high strength of concrete is improved by adding 15 % of SBR in concrete.

7 illus, 2 tables, 28 ref

040923   ALALWAN H A, ABBAS M N, ALMINSHID A H (Mechanical Technical Dep, Middle Technical Univ, Baghdad, Iraq) : Uptake of cyanide compounds from aqueous solutions by lemon peel with utilising the residue absorbent as rodenticide. Indian Chem Eng 2020, 62(1), 40–51.

Lemon peel was examined in this work as innovative inexpensive biosorption material for cyanide (CN⁻) removal from aqueous solution. The influence of adsorbent amount, feed flow rate, CN⁻ concentration, and solution pH on the breakthrough and saturation points was determined. To determine the design parameters required to scale-up the system, this work explores six different kinetics models. The data showed that the breakthrough curve is highly dependent on the investigated parameters. The system showed perfect performance, achieving more than 99 % removal of CN⁻ at the optimum conditions for the first 25 min. Furthermore, this work examined utilising the used adsorbent, saturated lemon peel with cyanide, as inexpensive rodent pesticide by tested on an outbred multi-purpose breed of albino rats and compare the results with the median lethal dose (LD₅₀) for those rats. The test results showed a foetal effect of the adsorption residue on the rats. This step will assure a safe method to dispose of the adsorption residue, as well as provide an inexpensive rodent pesticide, which increases the economic feasibility of this removal technique.

6 illus, 1 table, 46 ref

042677   HEKMATIPOUR F, JALALI M, MAROUFI A, HEKMATIPOUR F (Hydraulics and Heat Engineering Dep, Don State Technical Univ, Rostov on Don, Russia, Email: farhad. hekmatipour@gmail.com) : Rostov on Don, RussiaEnergetic and exergetic analysis of the lowtemperature heating system in a model library. Indian J Sci Technol 2020, 13(5), 587 – 96.

Energetic and exergetic analysis of the low-temperature heating system in a model library are conducted numerically in this research. The method of numerical investigation and simulation are employed to compute the energetic and exergetic analysis of the low-temperature heating system in a model library. The use of C++ programming and Hourly Analysis Program software were done the simulation and optimization. The results of this investigation are presented in this article. Simulation presents that the most of energy which is required for heating is capable to be declined using low-temperature heating system in a model library. It is shown that gas consumption decreases when lowtemperature radiators are applied and the value which is obtained is about 61,458,480 m³/yr. This means that the performance of the lowtemperature radiation is better than high-temperature radiator and it is about 57,150,000 m³/yr. The use of low-temperature radiators and high-temperature radiators are compared in this article. The radiator quality factor of the low-temperature radiators and hightemperature radiators are obtained 0.13 and 0.22, respectively. By using the low-temperature method, radiator quality factor is able to be declined 7 % of the energy efficiency. Based on these cases, using the low-temperature system can be used in some regions in Iran. The economic investigation shows that the IRR is evaluated based on discount 30 %, and interest rate 22 % in 20 years. The declination of energy consumption in building is significant. Therefore, a method which can use to reduce energy consumption is low-temperature heating in winter.

2 illus, 2 tables, 22 ref

040920   UTTARAVALLI A N, DINDA S (Chemical Engineering Dep, BITS-Pilani Hyderabad Campus, Hyderabad - 500 078) : Studies on synthesis of environment-friendly products for paint and coating applications. Indian Chem Eng 2020, 62(1), 1–14.

In the study, environment-friendly products, such as ketonic resins were prepared by self-polymerisation of ketonic monomers in the presence of a base catalyst using a high-pressure batch reactor. The crosspolymerisation reactions of ketonic monomers were also examined in the work. The effects of reaction parameters, such as reaction time, temperature, catalyst concentration and monomer concentration on physico-chemical properties of the product, such as physical state, hydroxyl value, iodine value, acid value, viscosity, average molecular weight, solubility, softening temperature and thermal stability have been studied. From the results, it was observed that the polymerisation reactions with methylcyclohexanone (MCH) or cyclopentanone (CP) monomers offered high viscous liquid resins. However, addition of small proportion (5–10 wt %) of MCH or CP along with cyclohexanone (CH) can play a significant role in obtaining a better quality product. It was also observed that CH and MCH monomers offered white colour resins, whereas CP monomer offered brown colour resins. The in-housedeveloped resins are thermally stable up to a temperature of around 180°C. From the overall investigation, it can be concluded that the inhouse-developed ketonic resin products can be a suitable substitute of alkyd, ketone−aldehyde or phenol−aldehyde resins for paint and coating applications.

9 illus, 7 tables, 24 ref

042673   TAPCHE R W, KENGNE J, NJITACKE Z T, PELAP F B (Electrical Engineering Dep, Dschang Univ, Cameroon, Email: wafotapche@gmail. com) : Uncertain destination of a 4D autonomous system with five line equilibria. Indian J Sci Technol 2020, 13(5), 519 – 38.

This paper introduces a novel 4D autonomous dynamic system with five line equilibria and a smooth nonlinearity. The new model is obtained by adding one more freedom degree to the 3D jerk system recently introduced by Kengne and Mogue, 2018. To analyze and study the model, Ruth criterion principle is used for the stability of different lines equilibria. Using traditional dynamics tools such as bifurcation diagrams, phase portraits, Poincare section, power spectrum, and Pspice software, the dynamic of the system is carried out. The new elegant system has an extremely rich dynamics predominated by the phenomenon of extreme multistability. The various sequences of coexisting route to chaos (coexisting bifurcation) confirm the uncertain destination of our novel elegant system. Note that, for the best of author’s knowledge, this is one of the best reproducible extreme multistable system because is not a flux control memristorbased system. The results obtained in this investigation enrich the literature and being used to improve the extreme multistability application in many research domains such as Random Number Generation (RNG) and image encryption.

10 illus, 1 table, 30 ref

042672   ONONOGBO C, NWUFO O C, OKORONKWO C A, OGUEKE N V, IGBOKWE J O, ANYANWU E E (Mechanical Engineering Technology Dep, Imo State Polytechnic, Umuagwo, Owerri, Imo State, Nigeria, Email: petermaryco@yahoo. com ) : Equipment sizing and method for the application of exhaust gas waste heat to food crops drying using a hot air tray dryer. Indian J Sci Technol 2020, 13(5), 502 – 18.

Equipment sizing and method of utilizing exhaust gas waste heat for food crops drying are presented. The sizing of the components of the equipment was achieved using known design principles. The system uses an axial flow turbine and a heat exchanger to harness the energy of the exhaust gas of a diesel engine generator. A 250 kVA generator with measured exhaust gas flow rate and temperature of 44.5 m³/min and 382.7 °C was selected for this work. The purpose of the recovered energy is for the drying of food crops. An arduino platform was used to control the operation of the components of the dryer. The drying chamber consists of three trays whose calculated total volume per batch is 0.0463 m³. Weight losses across the trays, drying air temperature and humidity in the chamber are monitored by sensors. The test rig of the sized and fabricated equipment is currently undergoing extensive experimentation. Preliminary investigation of the dryer showed that the drying air in the chamber initially at the temperature and humidity of 31 ºC and 71.2 % was heated to 88 ºC and 22.3 % when the dryer operated without load for 45 min at an air speed of 2.0 m/s. After cooling and maintaining the drying chamber averagely at 59 ºC, each tray was loaded with 400 g of the grains of freshly harvested maize. The dryer was allowed to run for 30 min and the results obtained showed weight losses of 127.81 g, 118.36 g, and 116.91 g for the grains in trays 1, 2, and 3, respectively. The application of this energy recovery system to the drying of food products, would help to save a considerable amount of primary fuel which is considered a viable means of cost saving and amelioration of environmental degradation. 

6 illus, 3 tables, 22 ref

042669   BHEEL V M, SHAIKH A A, MEMON A A, AWAN S K, TALPOOR M A (Basic Engineering Dep, Sindh Agriculture Univ, Tando Jam, Sindh, Pakistan, Email: veeromal@ sau.edu.pk) : Development of inverse mathematical model of rouse formula to estimate suspended sediment concentration along width of channel. Indian J Sci Technol 2020, 13(4), 460 – 74.

The sedimentation is a burning issue all around the world; hence this research will help the irrigation engineers to solve the sedimentation problems related to irrigation channels, hydraulic structures as well as in the field of agriculture. In this present research study, the inverse mathematical model of Rouse formula is developed to calculate the suspended sediment concentration along the width of an open channel. For derivation of the model, a well-known differential advection–diffusion equation is solved analytically with respect to x-axis along the width of channel. The model is also validated and checked with experimental results and calculated results by the newly developed model. A mathematical model has been developed for suspended sediment concentration along the width of channel. Furthermore, this model applied and compared with experimental results and observations which were conducted in open channel. Finally, for more validation and reliability of a newly developed model, the average maximum and minimum percentage errors are computed. These errors indicate that the proposed model has the best accuracy and resemblance when percentage errors of the newly developed model are computed. A newly developed model can be applied to estimate suspended sediments concentration from open channels. This model is also useful for irrigation engineers to find out suspended sediments concentration profiles along the horizontal direction from the centre to channel banks at the mid-depth of water. 

5 illus, 6 tables, 11 ref

042648   GHANIM A A J (Civil Engineering Dep, Najran Univ, Najran, Saudia Arabia, Email: aaghanim@nu.edu.com ) : Modeling rainfall runoff relations at arid catchments using conceptual hydrological modeling approach. Indian J Sci Technol 2020, 13(3), 329 – 39.

To develop a simple deterministic lumped conceptual rainfall-runoff model. This study developed a model based on the water balance, in which the model tracks precipitation, simulated soil water content, surface runoff, evapotranspiration, percolation, and return streamflow. The major input requirements for this model are hourly rainfall, hourly potential evaporation and the average daily streamflow record. The model is calibrated and tested using the available data collected from only one semi-arid ephemeral catchment located in the central part of Jordan. The model was optimized using Shuffle Complex Evolution (SCE.UA) optimization method. The performance of the model was evaluated using the goodness of fit measures. The simulation results obtained show that the proposed model has a good match between observed and simulated streamflow for both optimization and validation stages. The good simulation results obtained indicate that the model will be useful in design of hydraulic structures and for effective management of water resources at arid and semi-arid catchments. In order to strengthen the validation and applicability of the proposed model, empirical research needs to be conducted. Further research is required to assess the predictive uncertainty associated with model parameters and other inputs.

4 illus, 1 table, 14 ref

042646   ZAHEER M O, SHAIKH A A, SHAIKH F (Mehran Univ of Engineering and Technology, Jamshoro - 76090, Pakistan, Email: Osama.mth.st@gmail.com ) : Analysis of unsteady mhd thin layer flow of fourth-order fluid through a vertical belt. Indian J Sci Technol 2020, 13(3), 299 – 315.

To study the unsteady magneto-hydro-dynamic (MHD) thin layer flow of a fourth-order fluid through a moving and oscillating belt. The well-known analytical technique, namely Adomian decomposition method (ADM) is used to solve the non-linear partial differential equation for governing equations of velocity profile with subjects to initial and boundary conditions for both lift and drainage problems. The solution is found in excellent agreement. The basic purpose to study the effect of MHD on velocity field and understand the behavior of this physical problem and the effects of different non-dimensional parameters the graphical results are provided.

12 illus, 12 ref

040870   GUPTA N, VEMPATI V, AGARWAL A (Aviation Pathology & Toxicology Dep, Institute of Aerospace Medicine IAF, Bengaluru - 560 017, Karnataka, Email: nehagupta17sep@gmail.com) : Dietary deficiencies among families of air warriors: Use of iron deficiency anemia as an index. Indian J Aerosp Med 2020, 64(1), 27-31.

Anemia is a prevalent health problem in India affecting all age groups. It has shown the highest prevalence among preschool children and occurs more commonly in the lower socioeconomic group. Observationally, it was noticed at an Air Force station that preschool children of air warriors had iron deficiency anemia at levels similar to those seen in lower socioeconomic groups. This prompted us to evaluate dietary practices among families of air warriors as a contributory factor to iron deficiency in these children. All anemic children diagnosed of iron deficiency in the age group of 6–59 months were included in the study. Data were compiled from the clinical history, dietary habits and laboratory parameters obtained. The dietary habits were analyzed based on parameters defined in the current infant and young child feeding guidelines such as exclusive breastfeeding, minimum meal frequency, minimum dietary diversity, and minimum acceptable diet. Mann–Whitney U-test was used to determine statistical significance of difference between means of two independent groups. Spearman correlation analysis between two independent variables was done and multiple linear regression analysis was performed to identify predictor variables for iron deficiency anemia. About 74.1 % of the anemic children fell into age group of 6–23 months (infants and young children). 75 % of children of the age group of 6–23 months were started on cow’s milk at the time of weaning. The average amount of cow’s milk consumed in a day was 0.7 L. In this age group, the minimum dietary diversity was observed in 11.1 %, minimum acceptable diet in 5.5 % and minimum meal frequency in 22.2 % of the children. In the same age group, a statistically significant negative correlation was observed between cow’s milk quantity given per day and hemoglobin (ρ = ‒0.77). A significant negative correlation was found between cow’s milk quantity and variables such as age and number of solid meals received in a day (ρ = ‒0.553 and –0.526, respectively). In multiple regression analysis with hemoglobin as the dependent variable, a significant negative association was observed with cow’s milk quantity. Age showed statistically significant positive correlation with hemoglobin (ρ = 0.762) which was also seen on linear regression analysis. Serum ferritin was low in 44.5 % while total iron-binding capacity was raised in 100 % of the cases. Iron deficiency anemia was disproportionately distributed among infants and young children (age group 6–23 months). Copious consumption of cow’s milk in this age group led to fewer solid feeds per day and lack of dietary diversity which led to an iron deficient state in these children. This probably resulted in manifestation of anemia in this population. The study brings out the need for dietary counseling for air warriors and their families to ensure better health and lower disease burden.

4 tables, 10 ref

040869   NARAYANAPPA D, SOWGANDHI C N, TRIPATHY N K, AGARWAL A (SMC, Chabua, Assam, Email: drdivya.n22@gmail.com) : An appraisal of happiness in civil aircrew. Indian J Aerosp Med 2020, 64(1), 23-6.

Commercial aviation is a unique occupation, where the professional responsibility to ensure the safety of the aircraft and its occupants lies with the pilot, making civil aviation a stressful and demanding job. Psychological fitness plays a crucial role in helping aircrew adapt to and deal with these occupational demands. In the past few years, the awareness and interest in mental health among civil aviators and the aviation industry have been on the rise. Happiness is characterized as a lasting state with positive emotions and life satisfaction. It is known to improve performance and reduce stress. Based on this, the main objective of this study was to conduct a survey to appreciate the level of happiness among civil aircrew. A widely used scale for assessment of happiness called Oxford Happiness Questionnaire (OHQ) was administered to both male and female civil aircrew (n = 100). OHQ is a 29-item self-reporting questionnaire. Internal consistency was calculated using Cronbach’s alpha which was found to be 0.97 on the current sample. Data collected were also studied to find a correlation between demographic variables and happiness index. A mean score of 4.87 was obtained in the OHQ which indicated that the civil aircrew perceived themselves to be quite happy. No significant relationship was found between age, experience, marital status, and happiness scores. This was a unique survey in which civil pilots flying both domestic and international flights from India were assessed in terms of their happiness level as a measure of psychological well-being. The participants consisted of a total of 100 aircrew, consisting of 87 males and 13 females. The happiness index in this sample was found to be moderate to high. Most of them perceived their lives and work to be meaningful, which led to high motivation and increased performance. The results also revealed that flying hours of civil aircrew had no significant relationship to happiness level, further indicating that age and experience of the pilots did not predict their happiness, which was akin to a number of researches conducted on the general population. Although the aircrew were found to be moderately happy, the happiness level could still be increased. Small and modest actions by both the aircrew and the airline industry may make a big difference to the happiness state of aircrew.

3 illus, 1 table, 12 ref

040868   BISWAL P, SWAMY S G (Human Engineering and Human Factors Dep, Institute of Aerospace Medicine IAF, Bengaluru - 560 017, Karnataka, Email: drpunyashlok@gmail.com) : Optimizing sizing schedules of aircrew helmets using machine learning techniques. Indian J Aerosp Med 2020, 64(1), 18-22.

Aircrew equipment assemblies are life critical equipment worn by the aircrew to ensure protection from various life-threatening environmental conditions that may occur in nominal or off-nominal flight conditions. It is important for the sizing system of body worn aircrew equipment to be divided into different size classes such that it is as representative of existing groups in the population as feasible. Machine learning techniques provide a powerful tool to develop efficient sizing systems that are representative of actual body types existing in the population. The objective of the study was to use machine learning clustering techniques to identify naturally existing body types to formulate an optimal sizing system for an aircrew helmet. The standard sizing schedule of an aircrew helmet using head length and head breadth was studied. An iterative semi-supervised machine learning protocol called K-means clustering was used to identify naturally occurring clusters of head types within the population. The cluster boundaries were identified to develop the final sizing schedule. Analysis of variance (ANOVA) with post hoc analysis was carried out on the four head lengths and head breadths. Four clusters of head type were identified using K-means clustering. This led to a sizing schedule which can be descriptively called “Short-Narrow,” “Short-Broad,” “Long-Narrow,” “Long-Broad.” ANOVA showed a statistically significant difference between the four clusters for both head length and head breadth. Consideration of several variables in sizing schedules often fails to meet desired fitment. Standard sizing methods use linear partitions on individual control parameters. In reality, the proportional variation between parameters is not linear. Machine learning tools help in identification of naturally occurring clusters within the database considering several variables at the same time. This study uses machine learning techniques to identify existing groups in a population and develop a final sizing schedule. Similar analysis for other aircrew equipment assemblies can be carried out to determine sizing schedules which assist in design and fitment.

3 illus, 1 table, 14 ref

042632   ULLAH N, KHAN F, KHAN A A, KHAN S, TAREEN A W, SAEED M, KHAN A (Balochistan Univ of Information Technology Engineering and Management Sciences (BUITEMS), Quetta, Pakistan, Email: najeebullah.hasni@ gmail.com ) : Optimal real-time static and dynamic air quality monitoring system. Indian J Sci Technol 2020, 13(1), 91 – 102.

The objective of this study is to design and implement an effective low-cost air quality monitoring system that has the ability to monitor real-time air quality over a wide geographical area. The proposed system is developed for CO and NO₂. As a test case, our developed system is deployed in Quetta city, both in static and dynamic situations and the concentration level of CO and NO₂ in the air are measured and stored, along with their time, date, and location. In order to analyze this information, the stored data are then transferred to a data collection center via short-range wireless communication. Many air quality monitoring systems exits in the market; however, most of these systems have several design limitations such as size, cost, inability to move, and demand for continuous internet connectivity. Therefore, in this study, we have designed and implemented an effective low-cost air quality monitoring system that has the ability to monitor real-time air quality over a wide geographical area. Moreover, unlike existing air quality monitoring systems, the proposed system does not require any continuous internet connection and it can monitor the concentration level of pollutants in the air both in a static position and in mobile situations. The test results show that our proposed system can perform very well in both static and mobile situations. The proposed monitoring mechanism can help environmental experts and the general public to develop a more robust strategy against the adverse effects of air pollution. 

9 illus, 2 tables, 22 ref

042552   SHARMA R P, RAJU M C , GHOSH S K , MISHRA S R, TINKER S (Mechanical Engineering Dep, National Institute of Technology Arunachal Pradesh, Arunachal Pradesh -791 112, Email: rpsharma@nitap.ac.in) : Time-dependent oscillatory MHD flow over a porous vertical sheet with heat source and chemical reaction effects. Indian J Pure Appl Phys 2020, 58(12), 877-84.

The current investigation focuses on unsteady, natural convection viscous incompressible, electrically conducting liquid motion over a vertical plane sheet flooded with permeable media with heat source and chemical reaction. A uniform magnetic field is applied in the transverse direction; the liquid augment in the water way determined by identical pressure, the transport of heat is inclined by radiation. The governing equations are solved by applying the perturbation method. The velocity, heat, and mass profiles are shown on graphs for different physical parameters.

9 illus, 3 tables, 12 ref

042544   SHARMA A, SINGH R C, SINGARI R M, BHANDARKAR S L (Mechanical Engineering Dep, Delhi Technological Univ, Delhi-110 042, Email: ranganath@dce.ac.in) : Force and temperature analysis during distinct machining environment using an optimization approach. Indian J Pure Appl Phys 2020, 58(11), 804-11.

Cryogenic cooling with liquid nitrogen has a wide field of scientific and engineering applications. The aim of the presented research work is to analyze the impact on cutting force and temperature during the LN₂ single supply at (i) rake face and double supply (ii) rake and flank face of TiN coated carbide cutting tool during turning of AISI D3 steel. Taguchi based S/N ratio was used for Design of Experiments (DoE) of L₁₈ orthogonal array. The four control factors were selected. The three factors like speed, feed and depth of cut were varied to three levels. The fourth factor was the machining condition which was varied to two levels. The cutting force and temperature were declined by 32-48 % and 34-46 % during the double supply of LN₂ at rake and flank face as compared to single supply at rake face. The influence and percentage of contribution of each factor were found out by Analysis of Variance (ANOVA). The double supply method with LN₂ supply at rake and flank face had the highest effect of contribution in the percentage as 77.13 % and 87.42 % for cutting force and temperature respectively. The values obtained during confirmatory runs were very close to the optimized results within the limits.

5 illus, 5 tables, 23 ref

042542   KUMAR G, KUMAR S (Electronics & Communication Engineering Dep, National Institute of Technology, Delhi-110 040, Email: gkumar3c@gmail.com) : Performance evaluation of a novel dense hybrid passive optical network for acceptable modulation technique using EDFA amplifiers. Indian J Pure Appl Phys 2020, 58(11), 787-94.

Good rating services in terms of high speed data rate, good quality video signal and high speed telecommunication is the prime requirement for the current customers which have resolved in this research work for the first time best of our knowledge for 200 customers with the power amplification from EDFA optical amplifiers. Further, transmission of three play services signals have carried out from different modulation techniques (RZ, NRZ, Manchester, DBPSK and DQPSK modulator) to get the best outcomes. Furthermore, analysis of recommended dense hybrid passive optical network (DHPON) has also done in terms of bit error rate (BER), quality factor (Q-factor), and jitter. Final evaluation has recommended that RZ modulation technique is the acceptable choice to deliver the best services for the customers end.

5 illus, 10 tables, 16 ref

042522   SINGH R, PRASAD D (Electronics & Communication Engineering Dep, Jamia Millia Islamia, New Delhi - 110 025, Email: dprasad@jmi.ac.in) : Novel current-mode universal filter using single FTFNTA. Indian J Pure Appl Phys 2020, 58(8), 599-604.

In this paper, a novel universal filter using single Four Terminal Floating Nullor Transconductance Amplifier (FTFNTA), two capacitors and one/two resistor has been proposed. Sensitivity of pole frequency (ω₀) and quality factor (Q₀) is analysed. Workability of proposed filter has been demonstrated by PSPICE simulations in 0.18µm TSMC CMOS technology.

9 illus, 3 tables, 13 ref

044593   SITHARA S, PRAMADA S K, THAMPI S G (Civil Engineering Dep, National Institute of Technology Calicut, Kozhikode- 673 601, Kerala) : Impact of projected climate change on seawater intrusion on a regional coastal aquifer. J Earth Syst Sci 2020, 129(1), 10.1007/s12040-020-01485-y.

Sea level rise (SLR) is one of the prime consequences of global warming as pointed out by the Intergovernmental Panel on Climate Change (IPCC). SLR adversely affects coastal regions; triggers coastal erosion, inundation, and affects the freshwater–seawater interface as well. This paper presents the results of a study in which a coastal aquifer under changing climate was simulated using a three-dimensional groundwater model. The study area covers a part of the coastal aquifer in Ernakulam district in the State of Kerala, India. Support Vector Machine (SVM) was used for projection of future sea levels under the representative concentration pathways (RCPs) 4.5 and 8.5, based on the projections of Phase 5 of the Coupled Model Intercomparison Project (CMIP5). Both thermosteric and halosteric components were taken into account in the projection of sea level. It was observed that sea level changes are significantly influenced by the halosteric effect. Results indicate that SLR in the year 2050 with respect to the levels in 2014 will be about 8.64 cm and 12.96 cm under RCPs 4.5 and 8.5, respectively. The repercussions of this rise in sea level on seawater intrusion into the coastal aquifer were evaluated by performing simulations with SEAWAT. Results of the study indicate that the effect of this SLR on seawater intrusion is negligible.

40 ref

044591   KAISSASSOU S, LENOUO A, TANESSONG R S, TAMO K, VONDOU A, POKAM W, KANKO J (Electrical and Telecommunication Engineering Dep, Yaoundé Univ, Yaoundé, Cameroon) : Investigation of anomalous propagation conditions in Central and West African stations using high-resolution GPS radiosonde observations. J Earth Syst Sci 2020, 129(1), 10.1007/s12040-020-01477-y.

A comprehensive study on the anomalous propagation (AP) conditions occurring over the central and west African stations was made from 2 years (January 2005–December 2006) high-resolution data measured by GPS (Global Positioning System) radio survey observations. Through data quality control and diagnostic analysis, the probability of AP occurrence and characteristic quantities of the three typical anomalous propagation conditions were given. The sub-refraction, super-refraction and ducting cases were investigated statistically using the vertical profile of modified refractivity gradient. Strong diurnal variation in the percentage occurrence of the AP had its peak during the wet months, while the dry months had the lowest values. From 0600 to 1800 local time (LT) at day (1800–0600 LT at night), the total percentage occurrence of super-refraction, sub-refraction and ducting were 82.5 % (78.5 %), 11% (15.5 %) and 6.5 % (6 %), respectively. Besides statistical results, local meteorological conditions prevailing over central and west Africa have also been discussed.

28 ref

044590   DEEPIKA B V, RAMAKRISHNAIAH C R, NAGANNA S R (Civil Engineering Dep, Shri Madhwa Vadiraja Institute of Technology and Management, Bantakal- 574 115, Udupi) : Spatial variability of ground water quality: A case study of Udupi district, Karnataka State, India. J Earth Syst Sci 2020, 129(1), 10.1007/s12040-020-01471-4.

Groundwater is a reliable source of fresh water for domestic and agricultural water users. It supports subsurface ecosystem by balancing the geo-biological and bio-geochemical processes at micro- and macro-scales of the ecosystem. Overexploitation, anthropogenic activities and improper agricultural practices have contributed to the pollution of groundwater sources all around the globe. The water quality index (WQI) is the most extensively used indicator which transforms the water quality information derived from several parameters into a single value/rating to categorize and provide a general perception of water quality standard. Groundwater quality analysis and mapping via geographical information system (GIS) proves to be beneficial in identifying the locations where the groundwater quality is deteriorating. In the current study, the WQI of groundwater was determined for the samples collected from open and tube wells located within the Udupi district of Karnataka state, India. The groundwater quality parameters such as pH, hardness, calcium, chlorides, nitrates, iron, fluoride, sulfates, manganese, sodium, magnesium, potassium, turbidity, and phosphate were analyzed for water samples collected from 112 randomly chosen open/tube wells in order to determine the WQI. Interpolation approaches such as inverse distance weighting (IDW) and kriging were adopted in the GIS environment to quantify the spatial variability of groundwater quality over the entire geographical area. The groundwater quality maps were generated using the best fit models. The results portray that, the accuracy of interpolation using IDW and kriging methods was dependent on the measures of central tendency and variability of water quality data of different parameters. The kriging interpolation was much accurate for most of the groundwater quality parameters compared to IDW maps. The WQI maps, perhaps signposted the poor quality of groundwater quality in about 1.88 % of the geographical area of Udupi district. Further, about 21.69 % of the area was affected by poor quality of groundwater where suitable strategies for replenishment of groundwater resources should be taken up by the concerned authorities. The spatial distribution maps of groundwater quality aid to locate vulnerable places where immediate action is required.

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044588   ANAND V, OINAM B, PARIDA B R (Civil Engineering Dep, National Institute of Technology, Manipur) : Uncertainty in hydrological analysis using multi-GCM predictions and multi-parameters under RCP 2.6 and 8.5 scenarios in Manipur River basin, India. J Earth Syst Sci 2020, 129(1), 10.1007/s12040-020-01492-z.

Climate change is likely to have adverse impacts on hydrological processes in a river basin, by altered runoff due to modifications in land use/land cover (LULC) and catchment hydrology. Substantial uncertainty exists to evaluate impacts of climate change on river catchment due to uncertainty in general circulation model (GCM) projections. In this study, impact of climate change on water balance and hydrological regime of Manipur River basin was investigated using SWAT model. A comprehensive semi-distributed soil and water assessment tool (SWAT) was used for future projection of changes in hydrological regime of Manipur River basin based on two representative concentration pathways (RCP 2.6 and RCP 8.5). A coupled model intercomparison project’s (CMIP5) based GCM downscaled outputs and future LULC projected data were used in the analysis. The projected temperature is likely to be increased by 2.84 °C and increase of 836 mm in annual average precipitation is projected under RCP 8.5 by 2090s. Change in meteorological condition and LULC will lead to increase in runoff, evapotranspiration and water yield by 57.79 m³/s (38.32 %), 318.7 mm (54.59 %) and 629.72 mm (89.82 %), respectively, by the end of 21st century. This study demonstrates the importance of water balance components and its spatial and temporal variation in the Manipur River basin. The key findings of this study reveals that the runoff, evapotranspiration and water yield will increase in the coming decades. Increase in water yield may lead to landslides in the hilly region and flooding in low lying areas in future.

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044582   NENGZOUZAM G, HODAM S, BANDYOPADHYAY A, BHADRA A (Agricultural Engineering Dep, North Eastern Regional Institute of Science and Technology, Nirjuli- 791 109, Arunachal Pradesh) : Spatial and temporal trends in high resolution gridded rainfall data over India. J Earth Syst Sci 2020, 129(1), 10.1007/s12040-020-01494-x.

A high resolution (0.25 °×0.25 °) daily gridded dataset was analysed to study the spatial and temporal trend in various regions of India during the period of 1901–2013. The non-parametric Mann–Kendall (MK) test has been applied to the time series (1901–2013) rainfall data in order to detect the trends for both rainfall depth and number of rainy days. Sen slope estimator test was also used to find out the magnitude of the trend. In addition, Pettitt–Mann–Whitney (PMW) test was employed so as to determine the probable change year. The results of trend analysis of rainfall depth showed maximum number of grid points having increasing trend in summer months, while the dry months showed higher grid points with significant decreasing trend. Jammu and Kashmir, in particular, was found to have increasing trend in all months for all three levels of significances, i.e., 1 %, 5 %, and 10 %, while NE (northeastern) region continuously reported significant decreasing trends. The annual trend analysis of the 30-year moving window of rainfall depth showed higher number of grid points with significant increasing trend during 1901–1950, decreasing trend during 1931–1980, and increasing trend again during 1961–2013. The PMW test for the rainfall depth and number of rainy days for 1901–2010 showed 1961 and 1974 as the most probable change point years with about 339 and 284 grid points agreeing upon it, respectively. The maximum increasing significant trends in rainfall was observed during south-west monsoon months. Recent years also reported an increase in rainfall intensity leading to probable increase of extreme events like floods and droughts.

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040616   BALAMURUGAN P, VINNILAVU G (Civil Engineering Dep, M.Kumarasamy Coll of Engineering, Karur - 639 113, Email: balamurugan.phd10@gmail.com) : Removal of methyl violet dye from industrial waste water using neem leaf powder. Indian J Ecol 2020, 47(2), 442-5.

The purpose of this study is to remove the dye from the paper mill industry waste water and to use neem leaf powder as an adsorbent. Bath adsorption parameters such as the effect of adsorbent dosage, contact time, agitation speed, pH, are studied. The maximum removal percentage by varying the pH of MV is 80.39 %, The maximum amount of adsorption using neem leaf powder was found to be 0.12 g for MV. Maximum removal percentage of MV is 74.2 %. Freundlich and Langmuir Isotherms were plotted and that concludes neem leaf powder is a good adsorbent for the removal of dye from the waste water.

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