004735   PANDEY A K, PANDEY K, PANDEY A , MORYA V K, SINGH L K (Biochemical Engineering Dep, Harcourt Butler Technical Univ, Kanpur- 208 002, Uttar Pradesh, Email: lalitdbtiitr@gmail.com) : Response surface and artificial neural network simulation for process design to produce L-lysine by Corynebacterium glutamicum NCIM 2168. Indian J Biotechnol 2019, 18(3), 269-79.

The L-lysine is one of the most important essential amino acid used in food and pharmaceutical industries. The present investigation was conducted to optimize the L-lysine production by Corynebacterium glutamicum (NCIM 2168). The production parameters such as the temperature, pH and glucose concentration (g/l) were optimised and evaluated by simulation method to develop a suitable model. The experimental design was done using central composite design (CCD). Total 20 set of experiments were performed according to the CCD. The factors and their responses were analysed by using the statistical tools: response surface methodology (RSM) and artificial neural network (ANN) linked with genetic algorithm (GA). The predicted optimum production of L-lysine was 19.003 g/l and 28.363 g/l by CCD-RSM and ANN-GA respectively. During validation by GA under optimized conditions, the L-lysine production was found to be 27.25 ± 1.15 g/l, which was significantly high than that obtained using CCD-RSM optimization method. The ANN coupled with GA was found to be a powerful tool for optimizing production parameters with high level of accuracy. This technique may be used for other fermentation products to optimize the important process parameters before scaling up the process to industrial level.

9 illus, 7 tables, 30 ref

004705   AKSOZ S (Metallurgy and Materials Engineering Dep, Pamukkale Univ, Denizli, Turkey, Email: saksoz@pau.edu.tr) : Wear behavior of hot forged NiTi parts produced by PM technique. Trans Indian Inst Met 2019, 72(7), 1949-57.

Pre-alloyed NiTi powders were pressed at 400 °C, sintered at 1250 °C for 2 h and then cooled down at the rate of 5 °C/min to room temperature inside oxygen-free furnace. Later these sintered parts were forged at ~ 1050 °C [(± 25 °C) (Forged.1: 15% and Forged.2: 30%)]. Wear behaviors of the un-forged and hot forged parts were investigated. Wear tests were carried out via a pin-on-disk wear testing device according to ASTM G132-96 standard. The wear tests were performed for various sliding distances (200 m, 400 m and 600 m) at the speed of 1.2 m/s and under different loads of 5 N, 10 N and 15 N. Vickers macro-hardness values were measured at HV2. The samples were analyzed via SEM, EDS and MAP to determine the microstructure. Wear losses, wear rates and friction coefficients were measured in detail. The results showed that the best values in terms of wear and friction coefficient were obtained for 30% hot forged sample which had a hardness value of 612 HV and a density of 5.94 g/cm³.

8 illus, 36 ref

004712   BHAT J, SATYANARAYAN (Mechanical Engineering Dep, Alva’s Institute of Engineering and Technology, Moodbidri- 574 225, Email: satyan.nitk@gmail.com) : Effect of cooling medium on microstructure, impact and hardness properties of Al–15Sn alloy. Trans Indian Inst Met 2019, 72(7), 1941-47.

In the present study, effect of quenching/cooling conditions on microstructure, impact and hardness properties of custom-made Al–15Sn alloy were investigated. Heat-treated Charpy V-notch rectangular bar specimens were suddenly quenched in normal water (28 °C), cold water (6 °C) and ice bath (0 °C). Further, experiments were repeated and allowed to cool in an open atmosphere (air) and furnace to achieve different cooling conditions. Impact and hardness properties were assessed for the alloy quenched/cooled in different conditions. Microstructures revealed that alloy quenched in cold water showed finest (4.9 µm) Sn phase particles compared to other cooling conditions. Specimen quenched in cold water exhibited highest impact energy (77 Joules) and hardness number (RHN 90.7) whereas as-received sample showed least impact strength (32 J) and hardness (RHN 73.5).

7 illus, 1 table, 21 ref

004723   KUMAR D (Mechanical Engineering Dep, Raj Kumar Goel Institute Of Technology, Uttar Pradesh- 201 003, Email: dipakmnnit@gmail.com) : Comparison of thermal fatigue of superni 718 SGTBCs and APSTBCs. Trans Indian Inst Met 2019, 72(7), 1927-39.

This paper presents a comparison of thermal fatigue behavior of sol–gel-derived dip-coated nanostructured nonconventional and conventional air plasma-sprayed seven percent weight of yttria-stabilized zirconia thermal barrier coatings (TBCs). The thermal fatigue test was performed on the thermal cyclic furnace in the temperature range of room temperature and 1100 °C. Microstructural evaluation and elemental analysis were done by using scanning electron microscopy/energy-dispersive spectroscopy, respectively. It was observed that the failure of both nanostructured and conventional TBCs ensured the crack-induced spallation of ceramic top coat. The results demonstrated that spinel oxide (mixed oxide of Cr, Co, Ni) formation over thermally grown oxides layer played a crucial role in both of the case of conventional TBCs and sol–gel-coated nonconventional TBCs. The thermal cyclic fatigue life of the sol–gel coatings was found to be 1.31 times higher than the conventional air plasma. The AFM images also confirmed the coating consisting of nanostructure as well as the surface irregularities which increased with rising temperature.

9 illus, 2 tables, 54 ref

004726   MAIDEEN A H, DURAISELVAM M, VARATHARAJULU M (Mechanical Engineering Dep, A. V. C. Coll of Engineering, Tamilnadu- 609 305, Email: hajamaideen2001@gmail.com) : Application of desirability function approach for optimized process parameters of electrical discharge alloying of Al 7075 with nickel powder. Trans Indian Inst Met 2019, 72(7), 1901-16.

Electrical discharge alloying was performed on Al 7075 alloy with nickel powder mixed dielectric fluid to enhance wear resistance and to examine the self-lubricating properties. The present work highlights the concept of alloying of Al 7075 with nickel as a constituent material. Material characteristics such as powder concentration and alloyed layer thickness were analyzed through scanning electron microscope, electron-dispersive spectroscopy, optical microscopy and wear analysis was done using a pin-on-disc apparatus. The influence of machine peak current (I), pulse on time (P_on) and pulse off time (P_off) on wear performance of electrical discharge alloyed Al 7075 structural material was studied using response surface methodology technique. Analysis of variance was used to identify the vital contribution of input parameters on the performance characteristics.

17 illus, 6 tables, 23 ref

004734   PAN C, SHI J, WEI J, ZHAO C, HE P, WANG H (Wuhan Univ of Science and Technology, Wuhan- 430 081, Email: panchenggang@wust.edu.cn) : Effect of preheating temperature on the microstructure and corrosion resistance of TiC–Ni Coating by CS/PHIP. Trans Indian Inst Met 2019, 72(7), 1869-79.

TiC–Ni composite coatings with different preheating temperatures were fabricated in situ on the H13 steel substrate by combustion synthesis combined with pseudo-heat isostatic press. The effects of preheating temperature on microstructure, surface porosity, mechanical properties and corrosion behaviour were investigated. The coatings were characterized by XRD, SEM–EDS and microhardness tester. The in situ composite coatings prepared at different preheating temperatures consisted of a network of Ni binder phase (white) and a spheroidal TiC phase (dark) embedded therein. The grain size of TiC, the proportion of the TiC-reinforced phase, surface hardness and interfacial bonding strength increased with increasing preheating temperature. The density and dimension of the AlNi₃ phase after the immersion test decreased with an increase in preheating temperature. The corrosion mechanism of the coating was that the Ni binder phase was corroded by aluminium and the TiC phase got oxidized.

15 illus, 52 ref

004722   KHANNA N, SURI N M, AGRAWAL C, SHAH P, KROLCZYK G M (Mechanical Engineering Dep, Institute of Infrastructure Technology Research and Management, Ahmedabad- 380 026, Email: chetanagrawal@iitram.ac.in) : Effect of hybrid machining techniques on machining performance of in-house developed Mg-PMMC. Trans Indian Inst Met 2019, 72(7), 1799-1807.

High demand of lightweight material makes magnesium alloys and composites more suitable to aerospace and automotive industries. However, poor corrosion resistance and fatigue resistance make its applications limited. Due to inherent capability of machining processes, the surface characteristics of the component can be improved. Many articles reported improvement in machinability of different difficult-to-machine materials while using ultrasonic-assisted turning (UAT) process and cryogenic-assisted turning individually. In this paper, the newly developed cryogenic–ultrasonic-assisted turning (CUAT) technique is used for the machining of in-house developed magnesium AZ91/SiC particulate metal matrix composite (PMMC). In this study, surface roughness and chip breakability index are measured under different machining methods, i.e. conventional turning (CT), UAT and CUAT. The full factorial method is used to design the experiments. A regression model of surface roughness is developed for CT and UAT processes and optimized using Jaya algorithm. Our results provide evidence of improvement in surface finish for UAT of magnesium AZ91/SiC PMMC in comparison with CT. An improvement up to 36.50% and 15% has been observed in surface roughness and chip breakability index, respectively, with CUAT process as compared to UAT process at optimized cutting parameters of the UAT process.

8 illus, 6 tables, 27 ref

004725   LUO X, FANG C, YAO F, ZHAO H, YAN S (Southwest Petroleum Univ, Chengdu- 610 500, Email: winifreed@163.com) : Effect of sintering parameters on the microstructure and mechanical properties of medical Mg–3Mn and Mg–3Zn prepared by powder metallurgy. Trans Indian Inst Met 2019, 72(7), 1791-8.

Magnesium alloys as the lightest commercial structural materials have wide application prospects such as in the medical application. However, it is difficult to sinter Mg alloys dense when powder metallurgy was used because of the oxide layers covered by the surface of Mg powders. To solve this problem, Mg–3Zn and Mg–3Mn alloys were sintered under vacuum system in this study. Mg–3Zn and Mg–3Mn compactions were sintered at different temperatures for 2 h based on their phase diagrams in the vacuum furnace. The results show that when sintered at 560 °C, the highest microhardness and relative density of Mg–3Zn alloy are 74.3 HV and 98.4%, respectively. For Mg–3Mn alloy, its highest corresponding value is 46.08 HV and 86.6%, respectively, when sintered at 600 °C. Mg–3Mn is more difficult to be sintered because it is denser than Mg–3Zn. The microstructure of sintered Mg–3Zn and Mg–3Mn mainly is composed of α-Mg and MgZn₂, and α-Mn, α-Mg and MnO₂, respectively.

10 illus, 2 tables, 14 ref

004714   CHEN X, LI Q, ZHU L, WANG S, ZHANG S, GUAN H (Xi’an Univ of Technology, Shanxi- 740 048, Email: liquanan2016@163.com) : Effect of Sm on microstructure, mechanical property and lattice constant of as-cast Mg–11Gd–2Y–0.6Al alloy. Trans Indian Inst Met 2019, 72(7), 1783-9.

Mg–11Gd–2Y–xSm–0.6Al (x = 0, 1, 3, 5) alloys were prepared in electromagnetic induction furnace by gas protection. The crystal structure, microstructure and mechanical properties of as-cast Mg–11Gd–2Y–xSm–0.6Al alloys were studied by X-ray diffraction, metallographic microscope, scanning electron microscopy and tensile testing. The results show that the main phases of Mg–11Gd–2Y–xSm–0.6Al alloys are α-Mg matrix, Mg₅Gd, Mg₂₄Y₅ and Mg₄₁Sm₅. The addition of Sm refines the microstructure and increases the number of second phase in the grain boundary. The diffraction peaks of the cylindrical plane (100)_α-Mg, base plane (002)_α-Mg and conical plane (101)_α-Mg are shifted to a low angle. The offset of diffraction peak and the lattice constant of α-Mg increase with the increase in Sm content. The crystal axis ratio decreases with the increase in Sm content. When the addition of Sm is 3%, the ultimate tensile strength reaches to 240 MPa, which increases by 17.07%. The improvement in mechanical properties is mainly attributed to the grain refinement and the decrease in the crystal axis ratio of α-Mg.

7 illus, 4 tables, 23 ref

004704   AGHAMOHAMMADI H, HOSSEINIPOUR S .J, RABIEE S M, JAMAATI R (Materials Engineering Dep, Babol Noshirvani Univ, Babol, Iran, Email: jamaati@nit.ac.ir) : Texture–microstructure correlation in hot-rolled AZ31. Trans Indian Inst Met 2019, 72(7), 1775-81.

The paper presents a correlation between microstructure and crystallographic texture in hot-rolled AZ31 magnesium alloy. The microstructure and texture evolution are investigated using optical microscopy, field emission scanning electron microscopy, X-ray diffraction, respectively. The results indicated discontinuous dynamic recrystallization, twinning dynamic recrystallization, and particle stimulated nucleation as the main mechanisms during hot deformation. The average size of grains decreased from 19 to 1 μm as the rolling reduction increased from 0 to 60%. A large area fraction of new grains was observed at 40% thickness reduction. At the beginning of plastic deformation, basal slip and extension twinning increased the intensity of {0001} basal fiber texture. Dynamic recrystallization had a considerable effect on weakening the basal texture. Interestingly, some unusual highly stable components including (011¯3)[78¯13],(011¯3)[2¯110],(011¯3)[78¯13],(011¯3)[2¯110], and (011¯3)[145¯3¯](011¯3)[145¯3¯] existed at all deformation conditions and their intensity remained nearly unchanged.

5 illus, 10 ref

004736   PATEL S K, SINGH V P, KURIACHEN B (Mechanical Engineering Dep, National Institute of Technology Mizoram, Mizoram- 796 012, Email: basilkuriachen@gmail.com) : Microstructural, tribological and mechanical properties evolution of ZrSiO₄/A4047 surface composite fabricated through friction stir processing. Trans Indian Inst Met 2019, 72(7), 1765-74.

In this study, zircon sand (ZrSiO₄)-reinforced aluminum surface composite up to 15 vol % of microparticles with an average diameter of 3 µm was prepared through multi-pass FSP. The microstructural, mechanical and tribological characterizations of the friction stir-processed ZrSiO₄/A4047 surface composite were evaluated. The effects of FSP passes (2, 4 and 6) were evaluated, and it suggests that the surface composite after 6-pass reveals better homogeneous distribution of reinforcement (ZrSiO₄) particle in the matrix. The tensile test showed 16, 24 and 44% with increase in FSP passes, respectively, compared to the base metal. Similarly, the microhardness of the surface composite produced through 6-pass FSP was increased to 112 HV while that produced through base metal increased to 74 HV. Also, it was observed that erosion–corrosion resistance and abrasion wear performance were significantly improved with increase in FSP passes.

8 illus, 3 tables, 47 ref

004728   MENG Z, ZHOU C, LIU X (Jiangsu Univ of Science and Technology, Zhangjiagang- 215 600, Email: chaoyang_zhou@163.com) : Effect of self-tempering temperature on precipitation of secondary phase in V–TI–N high-strength seismic bars. Trans Indian Inst Met 2019, 72(7), 1757-63.

The effect of self-tempering temperature on precipitation of secondary phase is studied by using a V–Ti–N hot-rolled anti-seismic reinforced bar (HRB500E) at 800–900 °C. The results show that the secondary phase precipitated in steel is mainly square titanium nitride and elliptical vanadium carbonitride, and the size of TiN is above 50 nm, while that of V(C, N) is below 20 nm. As the self-tempering temperature decreases, the size of V(C, N) decreases, but the amount of precipitates at 850 °C is close to 900 °C, and the size is slightly less than that at 800 °C. With the decrease in self-tempering temperature, ferrite grains are gradually refined, yield strength increases, and strength ratio and elongation decrease. By controlling self-tempering temperature at 850 °C, the excellent comprehensive performance can be acquired with matched strength and toughness simultaneously.

6 illus, 4 tables, 17 ref

004717   GAIROLA S, JOSHI A, GANGIL B, RAWAT P, VERMA R (Mechanical Engineering Dep, Govind Ballabh Pant Institute of Engineering and Technology, Pauri- 246 194, Email: amitj4765@gmail.com) : Correlation of tensile properties and fracture toughness with microstructural features for Al–Li 8090 alloy processed by cryorolling and post-rolled annealing. Trans Indian Inst Met 2019, 72(7), 1743-55.

The influence of cryorolling and post-deformation annealing on the tensile and fracture behaviour of aluminium–lithium (Al 8090) alloy is reported in the present investigation. The solution-treated (ST) alloy was cryorolled (CR) up to the true strain of 2.3 to achieve ultrafine-grained (UFG) microstructure and then annealed at different temperature ranging from 100 to 350 °C. CR samples showed a significant increase in tensile strength (~ 373 MPa), hardness (~ 120 HV), and fracture toughness [K_Q (21.9 MPa √m√m), K_ee [27.9 MPa √m√m), J integral (21.8 kJ/m²)], while huge drop in ductility of CR alloy is observed as compared to coarser grain ST alloy. After annealing in the temperature ranging from 100 to 350 °C, the significant changes in the tensile and fracture behaviour of bulk UFG Al 8090 alloy were noticed. The tensile strength and fracture toughness were gradually improved up to the temperature 150 °C and observed to be maximum (~ 561 MPa) at 150 °C, while beyond this temperature, a significant drop in these properties was observed. The improved tensile and fracture properties of cryorolled followed by annealed alloy at 150 °C could be attributed to the precipitation of S′ (Al₂CuMg) and δδ (Al₃Li) phase as observed from XRD and TEM studies.

12 illus, 4 tables, 27 ref

004739   RAYAPUDI V, DHAWAN N (Metallurgical and Materials Engineering Dep, Indian Institute of Technology Roorkee, Uttarakhand- 247 667, Email: ndhawan.fmt@iitr.ac.in) : Microwave processing of banded magnetite quartzite ore for iron recovery. Trans Indian Inst Met 2019, 72(7), 1697-1705.

The effective utilization of low-grade banded iron ores is inevitable to meet India Steel Vision 2030 of producing 300 MT steel. In this study, banded magnetite quartzite iron ore (Fe ~ 41%) is physically beneficiated and microwave-treated followed by low-intensity magnetic separation. The appearance of massive random cracks during microwave treatment assisted the release of iron values from the matrix. Magnetite phase is strongly receptive to microwave exposure, thereby enhancing the separation characteristics. The Box–Behnken statistical design yielded an optimum concentrate with 60.1% Fe, 99% Fe recovery and 71% yield without any chemical additive. The single-step microwave exposure and low-intensity magnetic separation can be employed for the beneficiation of other low-grade iron ores.

9 illus, 3 tables, 17 ref

004733   PAMBUK C I A, MUHAMMAD F M (Tikrit Univ, Tikrit, Iraq, Email: dr.chatin2@yahoo.com) : Nanorobots or antitumor nanotanks : The new cancer termination strategies from reality to meth. Biosci Biotech Res Asia 2019, 16(3), 533-5.

Nanorobotics is a technology for making machines, robots in nanometer scale. More specifically, nanorobotics largely refer to the still-hypothetical technique of nanotechnology in the design and construction of nanoparticles and devices that range in size from 0.1-10 micrometers and are constructed from own molecular components or the molecules like DNA . However, it is still a hypothetical idea. Terminology such as nanobots, nanoids, nanites, nanomachines, or nanomites are also being circulated to describe these devices under research and development. A new technique in medicine will open up new avenues of hope for cancer patients. This technique relies on cell differentiation And the destruction of cancer cells without destroying body cells in less than 24 hours Unlike destructive chemotherapy, this technique is based on a new science called “Nanotherapy”, specifically Nano robots. The aim of this descriptive minireview, generally, is to shed light on the main Applications of Nanorobotics as Antitumornew strategies.

15 ref

004708   AZIMI H, BONAKDARI H, EBTEHAJ I, SHABANLOU S, TALESH S H A, JAMALI A (Civil Engineering Dep, Razi Univ, Kermanshah, Iran, Email: azimi86hamed@gmail.com) : A pareto design of evolutionary hybrid optimization of ANFIS model in prediction abutment scour depth. Sadhana 2019, 44(7), 169.

In this paper, a novel pareto evolutionary structure of adaptive neuro-fuzzy inference system (ANFIS) network is presented for abutment scour depth predicting. The genetic algorithm (GA) and singular value decomposition (SVD) is utilized in optimizing design of nonlinear antecedent parts and linear consequent parts of TSK-type of fuzzy rules simultaneously in ANFIS design for the first time. To this end, first the parameters affecting the scour in the vicinity of abutments are detected. After that, 11 ANFIS-GA/SVD models are introduced through the combination of the parameters affecting the scour. Based on the modeling results, the ANFIS-GA/SVD models predict the scour around abutments with a reasonable accuracy. The superior model forecasts more than 63% of scours with an error of less than 8%. The correlation coefficient (R) for the model is computed roughly 0.978. The value of the average discrepancy ratio for the model is obtained 0.981. In addition, the results of the sensitivity analysis demonstrate that the Froude number (Fr) and the ratio of the flow depth to the radius of the scour hole (h/L) are the most noticeable parameters affecting the scour depth in the vicinity of the abutments. Ultimately, a comparison between the superior model and the previous studies are presented which reveal that the current study has better performance to predict scour depth around abutments.

8 illus, 5 tables, 40 ref

004710   BALL A K, DAS R, ROY S S, KISKU D R, MURMU N C (National Institute of Technology Durgapur, Durgapur- 713 209, Email: amit.ball@yahoo.com) : Experimentation modelling and optimization of electrohydrodynamic inkjet microfabrication approach: A Taguchi regression analysis. Sadhana 2019, 44(7), 167.

Electrohydrodynamic (EHD) inkjet is a modern non-contact printing approach, which uses a direct writing technology of functional materials to achieve micro/nanoscale of printing resolution. As an alternative to conventional inkjet technology, the goal of the EHD inkjet printing is to generate uniformly minimized droplets on a substrate. In this study, the effects of applied voltage, standoff height and ink flow rate on droplet diameter formation in EHD inkjet printing process were analysed using Taguchi methodology and regression analysis. Several experiments were carried out using an L₂₇ (3¹³) orthogonal array. Based on signal to noise (S/N) ratio and mean response, optimal droplet diameter was achieved. The analysis of variance (ANOVA) was used to find the significance and percentage of contribution of each input parameter along with their interaction on the output droplet diameter. Analysis of the results revealed that the ink flow rate was the dominant factor that affected the droplet diameter mostly. The effect of the applied voltage is significant until regular ejection starts. It helps reduce droplet diameter more than five times compared with its initial droplet diameter in the absence of the electric field. A confirmation test was carried out with a 90% confidence level to illustrate the effectiveness of the Taguchi optimization method. Both linear and quadratic regression analysis were applied to predict the output droplet diameter. The predicted result from the model and actual test results are very close to each other, justifying the significance of the models.

7 illus, 10 tables, 61 ref

004730   NAGARE M B, PATIL B D, HOLAMBE R S (Instrumentation Engineering Dep, Ramrao Adik Institute of Technology, Navi Mumbai- 400 706, Email: nagaremukund@gmail.com) : Design of two-dimensional PR quincunx filter banks with Euler– Frobenius polynomial and lifting scheme. Sadhana 2019, 44(7), 165.

Two-dimensional (2-D) filter banks (FBs) have played a significant role in retrieving the directional information of images. In this paper, we propose a technique to design 2-D two-channel perfect reconstruction (PR) FBs with quincunx sampling. The proposed design method comprises two stages. In the first stage, we propose the design of a new halfband polynomial using Euler–Frobenius polynomial (EFP). This is constructed by imposing vanishing moment and PR constraints on EFP. The resulting new polynomial is a maximally flat Euler–Frobenius halfband polynomial (EFHBP). Later, in the second stage, EFHBP is used in a modified 2-D lifting scheme to design 2-D filters. The design examples for 2-D filters are presented and compared to existing filters. The performance shows that proposed filters have better regularity, symmetry and less energy of the error compared with existing FBs. Finally, performance of designed filters is evaluated in image denoising application.

6 illus, 2 tables, 6 ref

004724   KUSHWAH A K, WADHVANI R (Computer Science and Engineering Dep, Maulana Azad National Institute of Technology, Bhopal- 462 003, Email: akushwah190@gmail.com) : Performance monitoring of wind turbines using advanced statistical methods. Sadhana 2019, 44(7), 163.

Estimation of wind power generation for grid interface helps in calculation of the annual energy production, which maintains the balance between electricity production and its consumption. For this purpose, accurate wind speed forecasting plays an important role. In this paper, linear statistical predictive models such as autoregressive integrated moving average (ARIMA), generalized autoregressive score (GAS) model and a GAS model with exogenous variable x (GASX) have been applied for accurate wind speed forecasting. Along with this, a non-linear statistical predictive modelling technique called non-linear GASX (NLGASX) has been proposed and applied to model non-linear time-series data. Furthermore, the proposed NLGASX model is optimized using modelling techniques based on neural networks, namely Sigmoid, TANH, Softmax and RELU. The proposed optimized NLGASX model performs far better as compared with other models. Wind speed is also used as an input to wind power curve model for predicting the wind power. According to the predicted wind power the annual energy has been calculated.

17 illus, 5 tables, 28 ref

004743   SEN S (Airplane Airframe and Engine Maintenance Dep, Selcuk Univ, Konya- 42250, Email: sensoner@selcuk.edu.tr) : Numerical investigation of the effect of second order slip flow conditions on interfacial heat transfer in micro pipes. Sadhana 2019, 44(7), 159.

Heat transfer that occurs in micro scale devices has a very important place among the engineering applications that cooling or heating. This heat transfer mechanism in devices having dimensions at micron level is a completely different problem in the macro level analysis. Therefore, in the calculations made, the flow events and heat transfer in micron scale pipes are calculated by using more realistic expressions. For this reason, in this study heat transfer in a circular micro pipe with wall and fluid conjugation for laminar rarefied gas flow in transient regime is investigated under the second order slip boundary conditions at the interface. Patankar’s control volume method is used here to solve the problem numerically. This analysis includes of axial conduction, viscous dissipation and rarefaction effects which are indispensable in micro-flow structure. From the results, it is seen that the values that are indicating heat transfer are excessively affected by wall thickness, viscous heating and gas rarefaction especially in transient regime.

8 illus, 5 tables, 36 ref

004751   SRIDAR S, AWIN E W, KOUSAALYA A B, KUMAR R (Metallurgical and Materials Engineering Dep, Indian Institute of Technology Madras, Chennai– 600 036, Email: nvrk@iitm.ac.in) : Thermal shock resistance of precursor derived Si-Hf-C-N(O) foams. Trans Indian Ceram Soc 2019, 78(2), 78-82.

Thermal shock resistance of precursor derived Si-Hf-C-N(O) foams at temperatures varying from 800 ^o -1000 ^oC subjected to multiple thermal cycles was investigated. The as-synthesized foams possessed interconnected pores with an average cell size of 1.09 mm. The X-ray diffractograms of the foams before and after thermal cycling showed that the amorphous nature of the foams was retained. FTIR spectra exhibited that there was no change in the bonding characteristics due to thermal shock. A damage parameter (DS) based on the compressive strength was used to quantify the extent of damage. Densification was expected to occur in the first thermal cycle and the strut structures did not show any sign of cracking. However, cracking of struts occurred in the third thermal cycle which caused severe damage.

10 illus, 15 ref

004752   THULASIRAM R, MANI S, MURUGESAN M, PALANISAMY C, KALIARAJ G S (Mechanical Engineering Dep, Dr Mahalingam Coll of Engineering and Technology, Pollachi– 642 003, Email: ramkimech89@gmail.com) : Effect of TiB addition on corrosion behavior of titanium composites under neutral chloride solution. Trans Indian Ceram Soc 2019, 78(3), 155-60.

In this work, the corrosion behavior of titanium composites of titanium-titanium boride composites for marine applications was investigated by conducting electrochemical polarization experiments in neutral chloride (3.5% NaCl) at room temperature. The composites with two different volume fractions (20% and 40%) of TiB were processed by three powder metallurgical techniques such as spark plasma sintering, hot isostatic pressing and vacuum sintering. Corrosion rate for all the processed composites was calculated from corrosion current density determined by extrapolation of Tafel curves. Further, electrochemical impedance spectroscopy analysis was also carried out for the composites. The results revealed that the composite with 38.3 vol% titanium boride processed by hot isostatic pressing exhibited improved corrosion resistance in neutral chloride solution compared to the other two techniques. Microstructure of the corroded composites showed the pit formation in the exposed surface.

4 illus, 3 tables, 30 ref

004729   MOHAMMED S, BIRRU A K (Mechanical Engineering Dep, National Institute of Technology, Manipur- 795 004, Email: anilbirru@gmail.com) : Friction stir welding of AA6082 thin aluminium alloy reinforced with Al₂O₃ nanoparticles. Trans Indian Ceram Soc 2019, 78(3), 137-46.

In this present investigation, AA6082-T6 thin aluminium alloy plates of 2 mm thickness were friction stir welded using fine ceramic Al₂O₃ nanoparticles as the reinforcing materials between the adjoining plates. The joining was done by hexagonal pin profile tool of tungsten carbide material with tool rotational speeds 710 rpm and 900 rpm. The number of passes of the welds was 2 and 3 with constant tool traverse speed of 40 mm/min. Microstructural study was done by employing an optical microscope and electron microscopy. The microstructural results show that the weld produced with tool rotational speed of 710 rpm, tool traverse speed of 40 mm/min and the number of passes 3 has the good distribution of the alumina nanoparticles in the stir zone leading to grain refinement. The reinforced sample welded with 3 passes achieved the highest average grain size number of 16.02 and highest ultimate tensile strength of 227.61 MPa, yield strength of 154.9 MPa and elongation percentage of 10.5%. The reinforcement-included welded sample exhibited highest hardness value of 74 Hv in the weld nugget zone.

15 illus, 2 tables, 40 ref

004720   JADHAV A L, YADAV G D (Chemical Engineering Dep, Institute of Chemical Technology, Maharashtra- 400 019) : Clean synthesis of benzylidenemalononitrile by knoevenagel condensation of benzaldehyde and malononitrile: Effect of combustion fuel on activity and selectivity of Ti-hydrotalcite and Zn-hydrotalcite catalysts. J Chem Sci 2019, 131(8), 79.

Benzylidene malononitrile find applications in pharmaceutical industries, pharmacology, biotech, specialty chemicals, perfumery, and for fluorescence-based assay to determine methane and is produced by polluting routes. Hydrotalcites (HT) have been very effective as solid bases in different reactions and their properties can be changed by using different synthetic methods. In this work, the effect of additional metal in the synthesis of Al-Mg hydrotalcite was systematically studied to prepare Ti-Al-Mg (Ti modified hydrotalcite) and Zn-Al-Mg HT (Zn modified hydrotalcite) using combustion method with glycine as well as glycerol as a fuel. All synthesized catalysts were evaluated in Knoevenagel condensation of benzaldehyde with malononitrile to give benzylidene malononitrile. The catalysts were completely characterized by SEM, EDXS, N₂ Adsorption, CO₂-TPD and NH_3-TPD and XRD techniques. Ti-Al-Mg hydrotalcite using glycine as a fuel was found to be the most active, selective and reusable catalyst. Langmuir-Hinshelwood-Hougen-Watson (LHHW) model was used to establish the reaction mechanism and kinetics. All species were weakly adsorbed leading to the second order power law model. Using mole ratio of 1:3 of benzaldehyde to malononitrile with ethyl acetate as a solvent and 2.5×10−42.5×10⁻⁴g/cm³ catalyst loading, 67.1 % conversion of benzaldehyde and 97.6 % selectivity to benzylidene malononitrile were achieved in 4 h at 60 ^∘C. The apparent activation energy was 10.01 kcal/mol. The process is green. 

12 illus, 6 tables, 41 ref

004711   BASU S, SEN A K, MUKHERJEE M (Chemical Engineering Dep, Birla Institute of Technology Mesra, Ranchi, Jharkhand) : Synthesis and performance evaluation of silica-supported copper chromite catalyst for glycerol dehydration to acetol. J Chem Sci 2019, 131(8), 82.

Sol-gel technique was used to prepare silica-supported copper chromite catalyst from acid hydrolysis of sodium silicate. The catalyst was characterized by BET surface area, FESEM, XRD, H₂-TPR and pyridine adsorption by FTIR. The catalyst was activated in a hydrogen atmosphere based on H₂-TPR result. The surface acidity of the catalyst was evaluated by NH₃-TPD and pyridine adsorption. XRD result of reduced catalyst showed the presence of Cu⁰, Cu¹⁺ and Cr₂O₃ in the catalyst. Glycerol dehydration was carried out at different temperature (180 °C to 240 °C) from aqueous glycerol solution with the reduced catalyst in a batch reactor. The glycerol conversion was reached 100 % with maximum acetol selectivity of 70 % for highest Copper chromite loaded (40 wt %) on silica at 220 °C in atmospheric pressure. The distilled liquid product was analyzed by high-performance liquid chromatography. Oxidized catalyst and spent catalyst showed lower glycerol conversion with low acetol selectivity than the reduced form of the catalyst. This is due to the cuprous ion in the reduced form of the catalyst, which acts as Lewis acid sites in glycerol dehydration.

15 illus, 5 tables, 53 ref

004745   SHAHRIARI M H, SHOKRGOZAR M A, BONAKDAR S, YOUSEFI F, NEGAHDARI B, YEGANEH H (National Cell Bank Dep, Pasteur Institute of Iran, Tehran, Iran, Email: mashokrgozar@pasteur.ac.ir) : In situ forming hydrogels based on polyethylene glycol itaconate for tissue engineering application. Bull Mater Sci 2019, 42(4), 193.

Novel strategies have been proposed to enhance the quality of surgery by scheming noninvasive methods. For this reason, photo-curable in situ forming hydrogels have been well developed during advancements in the regenerative medicine. In this study, polyethylene glycol itaconate (PEGI) was synthesized by reacting polyethylene glycol (PEG) with different molecular weights (1000, 4000 and 8000 g mol⁻¹) and itaconyl chloride. The synthesized PEGIs were fully characterized and employed as a macromonomer for the preparation of in situ forming hydrogels using a combination of camphorquinone and dimethylaminoethyl methacrylate as a reactive photoinitiator system, and hydroxyethyl methacrylate as a reactive diluent. The physical properties of the hydrogels including gel yield, equilibrium swelling and compressive strength were determined. The hydrogel based on PEG 4000 with a gel yield of 86 %, a water uptake of 103 %, a compressive modulus of 11.2 MPa, an elongation at break of 9 % and a curing time of 4 min was selected for the encapsulation of rabbit articular chondrocyte cells. The cytocompatibility of the in situ formed hydrogels was evaluated using 3[4,5-dimethylthiazol-2-yl]- 2,5-diphenyltetrazolium bromide, live-dead fluorescence assays and optical microscopy observations. Glycosaminoglycans were quantified by dimethylmethylene blue staining from the encapsulated chondrocytes after 14 days. The proposed in situ forming hydrogel can be considered as an injectable and photocurable carrier for cell delivery in cartilage tissue engineering.

4 illus, 2 tables, 41 ref

004755   ZHAO L, CHU S, CHEN X, CHU G (Sun Yat-Sen Univ, Guangzhou- 510 275, People’s Republic of China, Email: 15198872657@126.com) : Efficient heat conducting liquid metal/CNT pads with thermal interface materials. Bull Mater Sci 2019, 42(4), 192.

Ga-Based thermal interface material (TIM) pads/sheets with high thermal conductivity (κ) are indispensable components in thermal management systems. Here, we present a feasible method to fabricate heat conduction pads, which are composed of carbon nanotubes embedded into a liquid metal (LM). This setup has resulted in a large increase of κ reaching ∼14.2 W mK⁻¹, greater than that of most of the commercial thermal silicone pads (∼5 W mK⁻¹). In addition, a series of experiments were conducted on smartphones to evaluate the heat dissipation performance of the CPU. It turned out that LM/nanotube pads with TIMs show distinguish thermal conductivity performance.

4 illus, 1 table, 43 ref

004715   DERIN O, KARAASLAN M, UNAL E, KARADAG F, ALTINTAS O, AKGOL O (Electrical and Electronics Engineering Dep, Iskenderun Technical Univ, Hatay- 31200, Turkey, Email: muharrem.karaaslan@iste.edu.tr) : Exhibition of polarization conversions with asymmetric transmission theory, natural like chiral, artificial chiral nihility and retrieval studies for K- and C-band radar applications. Bull Mater Sci 2019, 42(4), 191.

In this study, asymmetric transmission, natural chirality phenomena and a retrieval study with chiral metamaterials (MTMs) are numerically and experimentally focussed, investigated and discussed by examining the polarization conversion effect. Suggested multi-functional designs have simple geometries (π-shaped), low losses and huge optical activities. In addition, these new designs are numerically and experimentally retrieved in the study. The proposed model has many advantages with respect to the asymmetric transmission and chiral MTM studies in the literature. These advantages are having simple geometries (π-shaped), large asymmetric transmissions, small chirality like natural materials and also huge chirality can also be provided by rotating one of the resonators. Besides, the proposed structure can be easily reconfigured for other frequency regimes to provide new chiral MTMs or can be adopted for different application areas from defence systems to stealth technology which will be examined in our future studies.

8 illus, 32 ref

004740   RHAMAN M M, MATIN M A, HOSSAIN M N, MOZAHID F A, HAKIM M A, ISLAM M F (Glass and Ceramic Engineering Dep, Bangladesh Univ of Engineering and Technology, Dhaka, Bangladesh, Email: mizan.eee@aust.edu) : Bandgap engineering of cobalt-doped bismuth ferrite nanoparticles for photovoltaic applications. Bull Mater Sci 2019, 42(4), 190.

The bandgap energy range of multiferroic bismuth ferrite is 2.2–2.7 eV, making it a promising candidate for photovoltaic (PV) applications. But its efficiency is still very low (<2 %). This report thus focusses on the application of bismuth ferrite (BFO) engineered with cobalt (Co) doping and on the tuning of its bandgap energy (Eg). BiFeO₃ is a unique multiferroic material that simultaneously displays both ferromagnetic and ferroelectric properties at room temperature. Co doped with pure BiFeO₃ (BiFe_(1−x)Co_xO₃; x = 0, 0.05, 0.1 and 0.15) was synthesized by the sol–gel method and annealed at 600 ^◦C. X-ray diffraction shows the well-arranged crystalline structure and peaks of pure and doped-BiFeO₃ nanoparticles. A suitable reduction of Eg has been observed for Co-doped BiFeO₃, which may be appropriate for the effective use in PV solar cells. Thermogravimetric analysis and differential scanning calorimetry were used to investigate the thermal decomposition character of the xerogel powder and the pattern of pure and doped BiFeO₃ phases. Field emission scanning electron microscopy images show the surface crystallography of pure and Co-doped BiFeO₃. Co-doped BiFeO₃  has considerably reduced the crystallite and particle size of the samples. We have calculated the E_g of pure and doped BiFeO₃ using a UV–Vis–NIR spectrophotometer and the results show the important reduction of E_g (1.60 eV) of the Co-doped samples, which may have potential applications in PV solar cells.

4 illus, 3 tables, 29 ref

004748   SINGH H, SOHI B S, GUPTA A (ECE Dep, Chandigarh Univ, Ajitgarh, Punjab, Email: harbinder.ece@cumail.in) : A compact CRLH metamaterial with wide band negative index characteristics. Bull Mater Sci 2019, 42(4), 186.

Metamaterials are the artificial materials that may have a negative refractive index and results in extraordinary properties which are not found in nature. This research focusses on designing a compact-sized artificial material for negative characteristics of permittivity, permeability and refractive index over the wide range of frequencies. The metamaterial design is evaluated for single negative, double negative and double positive behaviours over a broad range of frequencies to investigate the gap and gapless transitions from backward to forward wave propagation. The dispersion diagram of the material is also investigated for left or right hand behaviour of the material. The equivalent circuit diagrams along with circuit simulations of the parameters are also presented for detailed analysis and understanding. The designed metamaterial behaves like a double negative material for low frequencies and double positive material for high frequencies. The approach is verified using CST microwave studio simulation and the results obtained are validated using the rectangular waveguide measurement method.

25 illus, 46 ref

004721   JAZDZEWSKA M, SLIWINSKA-BARTKOWIAK M, DOMIN K, CHUDOBA D M, BESKROVNYI A I, NEOV D S, GUBBINS K E (Adam Mickiewicz Univ, Poznan, Poland, Email: msb@amu.edu.pl) : Structure of ice confined in carbon and silica nanopores. Bull Mater Sci 2019, 42(4), 184.

In this work, water confined in silica and carbon nanopores has been examined. The purpose of this study is to describe the melting behaviour and structure of ice confined in silica nanopores, KIT-6 and ordered carbon nanopores, CMK-3, having pore diameters of 5.9 and 5.2 nm, respectively. To determine the melting temperature of ice inside the nanopores, we performed differential scanning calorimetry measurements of the systems studied. We found that the melting temperature of confined ice is reduced relative to the bulk melting point and this shift is 16 K for water confined in KIT-6 and 21 K for water confined in CMK-3. The structural properties of water at the interfaces were analysed by using the neutron diffraction method (ND). The ND measurements for all the systems studied, showed the features of both hexagonal ice, I_h, and cubic ice, I_c. However, we show that the ice confined in nanopores does not have a structure corresponding to the typical hexagonal form or the metastable cubic form. The ice confined in nanopores has a structure made up of cubic sequences interlaced with hexagonal sequences, which produce the stacking disordered ice (ice I_sd).

5 illus, 1 table, 56 ref

004727   MAJUMDER S, MATIN M A, SHARIF A, ARAFAT M T (Biomedical Engineering Dep, Bangladesh Univ of Engineering and Technology (BUET), Dhaka 1205, Bangladesh, Email: tarikarafat@bme.buet.ac.bd) : Understanding solubility, spinnability and electrospinning behaviour of cellulose acetate using different solvent systems. Bull Mater Sci 2019, 42(4), 171.

The purpose of this study is to understand the solubility and spinnability of cellulose acetate (CA) and its electrospinning behaviour in different solvents. As the process of electrospinning and the corresponding fibre properties are primarily governed by the solvents used, a systematic study of the selection of solvent systems using the solubility parameters of Hildebrand and Hansen along with a Teas chart for a particular polymer is essential for the better optimization of the process. It appeared from the Teas chart that higher dispersion force ( f_d) and lower hydrogen bonding force ( f_h) are convenient for both the solubility and spinnability of CA in single solvent of acetone and binary solvent of 2:1 acetone/N,Ndimethylacetamide (DMAc). The viscosity of the solutions escalated with increasing concentration of CA due to polymer chain entanglement which in turn favoured fibre formation. Among the solvent systems used in this work, field emission scanning electron microscopy arrayed the electrospun CA fibres using pure acetone as a solvent produced both cylindricaland ribbon-shaped fibres of a diameter of 1 μm, whereas CA in 2:1 acetone/DMAc yielded smooth bead-free cylindrical fibres of diameter in the range of 250–350 nm and CA in 3:1 acetic acid/water formed fibres with beads. Rheological analysis showed that fibre formation improved with increasing viscosity of CA solution. Electrical conductivity measurement of the CA solutions depicted that with an increase in CA concentration, fibre diameters were increased, whereas the conductivity decreased. Also, attenuated total reflectance–Fourier transform infrared spectroscopy confirmed the major peaks of CA for all the electrospun samples.

7 illus, 2 tables, 42 ref

004742   SATYANARAYANA G, NARAYANA K L, RAO B N (Mechanical Engineering Dep, Koneru Lakshmaiah Education Foundation, Green Fields, Vaddeswaram, Guntur 522 502, Email: bnrao52@rediffmail.com) : Numerical investigation of temperature distribution and melt pool geometry in laser beam welding of a Zr–1 % Nb alloy nuclear fuel rod end cap. Bull Mater Sci 2019, 42(4), 170.

Zr–Nb alloys are used in the nuclear and chemical industries, in which the welding of an end cap to a fuel rod is a critical issue in manufacturing processes. To identify the optimal process parameters for achieving good-quality welds, it is necessary to investigate the thermal environment in the fusion and heat-affected zones. A three-dimensional computational fluid dynamics analysis is performed with a volumetric heat source by simulating the interaction of the heat source and the material and by accounting for the phase change during welding. The model incorporates the buoyancy force and Marangoni stress and generates the temperature distribution, weld bead geometry and fluid flow in the weld pool during the laser welding process.

22 illus, 2 tables, 37 ref

004741   SADEGHI F, ANSARI R (Mechanical Engineering Dep, Guilan Univ, Rasht, Iran, Email: Fatemeh_sadeghi_64@yahoo.com) : A detailed parametric study on the operating frequency of chloride ion-electrically charged carbon nanotube oscillators. Bull Mater Sci 2019, 42(4), 165.

Fabrication of new types of nanoscale oscillators with enhanced operating frequency has become the focal centre of interest. The aim of this paper is to explore the mechanical oscillatory behaviour of chloride ion tunnelling through carbon nanotubes (CNTs) decorated with identical functional groups at both ends. To this end, our previously proposed analytical expression for total potential energy between an ion and a functionalized CNT is used to derive a new semi-analytical expression for the accurate evaluation of oscillation frequency. With respect to the proposed frequency formula obtained from the conservation of mechanical energy principle, a comprehensive study is conducted to gain an insight into the effects of different parameters such as, sign and magnitude of functional group charge, nanotube length and initial conditions on the operating frequency of chloride ion-electrically charged CNT oscillators. It is revealed that the presence of functional groups, especially ones with the opposite charges to the chloride ion, leads to enhancement of the maximum achievable frequency. It is further observed that optimal frequency is attained when the ion oscillates near the ends of a positively charged nanotube.

11 illus, 1 table, 55 ref

004750   SOULEYMANOU A, ALI K K, REZAZADEH H, ESLAMI M, MIRZAZADEH M, KORKMAZ A (Amol Univ of Special Modern Technologies, Amol, Iran, Email: H.rezazadeh@ausmt.ac.ir) : The propagation of waves in thin-film ferroelectric materials. Pramana – J Phys 2019, 93(2), 27.

The nonlinear evolution equation describing the propagation of waves in thin-film ferrroelectric materials is investigated in detail. The modified extended tanh method is used for the purpose and, as a result, novel soliton solutions are derived analytically which show the shape and the width of the waves. In the construction of the solutions obtained, it appears that bright and singular waves can be propagated in thin-film ferroelectric materials.

1 illus, 32 ref

004706   ASKIN A, DAL M (Mechatronics Engineering Dep, Munzur Univ, Tunceli, Turkey, Email: aliaskin@munzur.edu.tr) : Assessment of the mass attenuation coefficients of granite, basalt, andesite and tuff stones with the Geant4 model of a high-purity germanium detector. Pramana – J Phys 2019, 93(1), 14.

In this work, the radiation shielding properties of various natural stones, such as granite, basalt, andesite and tuff, were determined by using Monte-Carlo simulations performed with the Geant4 model of a high-purity germanium (HPGe) detector. Mass attenuation coefficients were calculated for γ -ray energies of 80.9, 140.5, 356.5, 661.6, 1173.2 and 1332.5 keV and for the sample thicknesses between 1 and 7 cm. The results of this study indicate that the stone samples have lower mass attenuation values varying in the range from −28.8 % to −3.7 % compared to lead. Among the measured stone samples, the mass attenuation values of tuff stone are closest to lead (above 661.6 keV).

3 illus, 3 tables, 19 ref

004732   PALASKAR J N, SINGH S, MITTAL S (Prosthodontics Dep, Sinhgad Dental Coll and Hospital, Pune - 411 041, Maharashtra, Email: jpalaskar@yahoo.com) : Evaluation and comparison of different polymerization techniques, curing cycles, and thicknesses of two denture base materials. Indian J Dent Res 2019, 30(4), 583-9.

The study aimed to compare the effect of different materials, thicknesses, and polymerization methods and cycles, on the surface porosity of acrylic denture base resins. Conventional heat‑polymerized polymethyl methacrylate (PMMA) and specially designed acrylic resin (Acron MC) were used to make 84 rectangular samples. They were divided into three groups to evaluate and compare the polymerization techniques, curing cycles, and thicknesses of the two denture base materials (28 samples each). Group A contained PMMA samples polymerized using water bath method (control group); Group B contained Acron MC samples polymerized by microwave method, and Group C contained PMMA samples polymerized by microwave method. Each group was further divided based on sample thickness and polymerization cycles. Each sample was scanned for surface porosity and area of each pore was measured using optical microscope. Data was analyzed using ANOVA, Bonferroni, and student t‑tests. Unpaired student t‑test was performed to compare the means of surface porosity with polymerization cycles and thicknesses among the groups. The power of study was kept at 80 %. Group C showed highest mean % of porosity depending on method of polymerization, different polymerization cycles (short and long) and polymerization cycles within the group. Group B showed the highest mean % of porosity depending on thickness and thickness within the groups. Microwavable acrylic resin polymerized by microwave energy exhibited statistically insignificant increase in porosity when compared to conventional heat cured acrylic resin by water bath method. Conventional acrylic resin polymerized by microwave energy exhibited high statistically significant porosity irrespective of sample thickness. There was statistically insignificant increase in porosity depending on sample thickness irrespective of material and method of polymerization.

7 illus, 4 tables, 19 ref

003368   ESKI H, KOCABICAK U, GELEN E (Computer Engineering Dep, Sakarya Univ, Sakarya, Turkey, Email: heski@sakarya.edu.tr) : Improving estimation of body lengths using extended Kalman filter for squat movement. Indian J Chem Technol 2019, 26(3), 274-8.

Modeling and analyzing of human movements has become easier with the development of sensor technologies. Human movements can be modeled using image processing software with depth and motion sensors in 3D. Measurement errors are also observed in motion detection sensors as in most systems. Special filters have to be developed for each system in order to minimize this error rate and obtain more realistic measurements. Kalman Filter is a well-known method that is commonly used to minimize this type of measurement errors. In this study, the actual body lengths (upper arm, forearm, lower leg, upper leg) are measured and obtained from the human motion sensor. Kalman Filter and Extended Kalman Filter are applied to the obtained data from human motion sensor. All measurements are compared with the actual body lengths and error rate is calculated as using Mean Absolute Percentage Error (MAPE). Kinect data are compared with actual lengths and error rates were calculated at 20%, when the Kalman Filter is applied, the error rate decreased to 14%, while when the Extended Kalman filter is applied, it dropped to 8%. Human motion sensor data have been improved with using Extended Kalman Filter. Thus, actual measurements of candidates can be easily obtained with only one useful sensor without taking any actual measurements by saving time and budget.

4 illus, 1 table, 22 ref

003369   EVCIN A, AKPINAR S, ERSOY B, OZGUL M, YAZICI Z O, UCAR M (Material Science and Engineering Dep, Afyon Kocatepe Univ, Afyon, Turkey, Email: evein@aku.edu.tr) : Surface modification of marble wastes in the silicone matrix using various carboxylic acids. Indian J Chem Technol 2019, 26(3), 270-3.

The effects of carboxylic acid type surfactants with different hydrocarbon chain lengths and molecular structures such as benzoic acid, oleic acid, acrylic acid and stearic acid on the surface modification of marble waste powder (MWP) have been investigated. For this purpose, composites have been produced in different compositions by using unmodified MWP and 5 to 10 wt% modified (surface coated) MWP containing silicons and then the hydrophobicity grades of the surfaces of these composites have been evaluated by determining the changes in the water-contact angle values. The results obtained show that the most suitable surfactant is steric acid to produce MWP powders having hydrophobic surfaces.

1 illus, 22 ref

003398   OZBEYAZ K, KAYA H, KENTLI A, SAHBAZ M, OGUT S (Mechanical Engineering Dep, Marmara Univ, Istanbul, Turkey, Email: kerim.ozbeyaz@marmara.edu.tr) : Mechanical properties and electrical conductivity performance of ECAP processed AA2024 alloy. Indian J Chem Technol 2019, 26(3), 266-9.

This paper presents an experimental examination of AA2024 aluminium alloy through Equal Channel Angular Pressing (ECAP), annealing, and ECAPed plus aging applications. The aim of this study is to compare and observe the effects of the a forecited processes in terms of hardness and electrical conductivity. ECAP is one of the frequently used methods for Severe Plastic Deformation (SPD). SPD give rises to obtain stronger mechanical properties of materials as an improvement technique in material science. Four AA2024 specimens are prepared. One is as received sample, second is annealed AA2024, third one is ECAP processed and the last one is ECAP and then aging processed form. Hardness measurement is done as mechanical properties investigation. In addition, microstructure behaviour with SEM is studied. Once again, electrical conductivity of all four specimens are examined. All parameters are compared with each other. After annealing process the hardness of AA2024 is reduced according to as received form. ECAP increased the hardness, despite this, the highest hardness value is observed on ECAPed plus aging processed sample. The electrical conductivity of AA2024 is increased after annealing process according to as received form. However, it reduced after ECAPed plus aging process. Nevertheless, ECAPed sample gained more conductivity and has the least resistivity.

5 illus, 21 ref

003366   ERGIN M F (Chemical Engineering Dep, Istanbul Univ, Avcilar- 343 20, Turkey, Email: mfergin@istanbul.edu.tr) : Performance optimization of a single-screw extruder with transparent barrel using mixture design method. Indian J Chem Technol 2019, 26(3), 261-5.

Extrusion is an inexpensive process in terms of production costs used to produce continuous shapes of plastic materials. The mixture design method and regression analysis have been applied to evaluate the performance of the single screw extruder. The performance values of the single-screw extruder system with a glass barrel are calculated by the residence time distribution results of the tracers. Then calculated particle distributions are compared with visual data. Ethylene vinyl acetate (EVA 210W) is used as the polymeric material. In the study, the EVA 210W is studied with various screw configurations and also process conditions. Optimization is fulfilled using the response optimizer to determine the optimum screw configuration. This method is aimed at feeding and metering zones in screw design and focuses on the search for a solution for optimum screw selection. In addition, the robustness of solutions in process conditions has been redefined.

6 illus, 5 tables, 15 ref

003357   CHEN W, SHEN M, LI G (Ocean Univ of China, Qingdao 266 100, China) : Highly-efficient adsorptive removal of tetracycline using magnetic sugarcane bagasse biochar modified by lanthanum. Nat Environ Pollut Technol 2019, 18(2), 639-43.

As one of the agricultural wastes, sugarcane bagasse was easily pyrolyzed under low temperature to obtain bagasse biochar. Lanthanum-modified Fe₃O₄ particles were immobilized on the bagasse biochar to prepare La-modified magnetic biochar. The magnetic biochar was characterized by scanning electron microscope and X-ray photoelectron spectroscopy. It was found that the sizes of these biochar flakes were predominantly within 50 µm. At the same time, La species and magnetic particles are well combined with the biochar substrate. The magnetic biochar with a presumed molar ratio of La/Fe₃O₄ at 1:100 demonstrated a higher adsorption capability, which was enhanced by 69.8% compared to the raw bagasse biochar. The experimental points were quite close to curves simulated by both Langmuir and Freundlich isotherm models. From Langmuir model, the R₂ values were 0.984, 0.980 and 0.983 at 288, 298 and 308 K, respectively. The maximum adsorption capacity (q_max ) for tetracycline reached 122.5 mg/g at 298 K and q_max increased with a rise in the reaction temperature, indicating the adsorption process was endothermic.

4 illus, 1 table, 19 ref

003387   LI G, YUAN Q, KHAN A A (Environmental and Municipal Engineering Dep, North China Univ of Water Resources and Electric Power, Zhengzhou- 450 011, China) : Effect of solution pH on the kinetic adsorption of tetracycline by La-modified magnetic bagasse biochar. Nat Environ Pollut Technol 2019, 18(2), 623-7.

Lanthanum-modified Fe₃O₄ nano-particles were innovatively immobilized on the bagasse biochar to prepare La-modified magnetic biochar, which demonstrated an especially high adsorption capability for the removal of tetracycline. The magnetic adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and zeta potential analysis. Through the FTIR analysis, it could be observed that La/Fe₃O₄ articles were successfully immobilized on the surface of the bagasse biochar. Zeta potential analysis showed that biochar surface became more negatively charged. Near neutral pH was more favourable for the removal of tetracycline. Elovich and pseudo-second-order kinetic models were better to fit the experimental data, indicating a chemisorption occurred in the adsorption process.

4 illus, 1 table, 21 ref

003390   LIU X, YUAN L, YUAN Y, LIU S (North China Univ of Science and Technology, Tangshan 063 210, China) : Phosphorus removal from wastewater by steel slag ceramsite filter. Nat Environ Pollut Technol 2019, 18(2), 579-85.

Ceramsite made from steel slag was used as filter material in a packed column to remove phosphorus (P) from wastewater. Influences of both contact time and P concentration on reactor performance were investigated. Additionally, chemical and mineralogical analyses were conducted to determine the mechanism of phosphorus removal. Results showed that Ca²⁺ and OH^- were released from ceramsite to remove phosphorus from liquid phase under alkaline condition. Nevertheless, suitable retention time facilitated the efficient use of Ca²⁺ for phosphorus removal. Under the optimal contact time (4h), P removal capacity of ceramsite media was 7.9 mg/g for 140 days (at influent concentration of 10 mg/L), and the impact of influent concentration (0.5~10 mg/L) on P removal was neglectable. The mechanism for P removal included solid dissolution, precipitation and surface adsorption, among which the dissolution of calcium and Ca-P precipitation were overwhelming. The Ca-P products proved to be poorly crystalline tricalcium phosphate (TCP) and carbonated apatite.

8 illus, 1 table, 16 ref

003426   YU R, HUANG X, XU G (Nanjing Univ, Nanjing- 210 093, China) : Towards a theory of decoupling: the relationship of carbon emission and construction land expansion between 1997 and 2012 in Hefei City, China. Nat Environ Pollut Technol 2019, 18(2), 569-77.

Low carbon has been one of the hottest research topics on global change and sustainable development field, and land use carbon emission is a leading research subject. Taking Hefei City as an example, this paper uses the Decoupling Theory to analyse the relationship of carbon emission and construction land expansion between 1997 and 2012. Based on the decoupling analysis, the Trend Index is established to judge the development direction of the relationship. This study focuses on solving two questions: on the one hand, the strict classification provides an accurate approach for calculating the carbon emission carried by construction land; on the other hand, the paper re-analyses the decoupling states of the two research objects that have same expected development direction, which is falling at the same time. The results show that the ideal decoupling relationship between carbon emission and construction land expansion is in the order of strong decoupling

2 illus, 6 tables, 35 ref

003380   JOSE J, SRIMURUGANANDAM B, NAGENDRA S M S (Vellore Institute of Technology (VIT), Vellore-632 014, Tamil Nadu) : Characterization of PM₁₀ and PM_2.5 emission sources at Chennai, India. Nat Environ Pollut Technol 2019, 18(2), 555-62.

Deteriorating ambient air quality is a substantial problem of concern for many urban agglomerations throughout the world. Particulate matter (PM) is a criteria pollutant that is of high interest in urban locations. The precise characteristics of PM in a given locale depend on the source origin, which in turn is a function of economic, social and technological factors. In order to effectively manage PM and thereby, the exposure risk to humans, it is very essential to identify the main sources and their contributions from source emissions. Receptor modelling plays a major role in identifying and apportioning sources of airborne PM across the world. Unmix model is a multivariate receptor model developed by the United States Environmental Protection Agency (U.S.EPA) based on factor analysis, which estimates the number of sources using a singular value decomposition method to reduce the dimensionality of data. In this study, Unmix receptor model version 6.0 is used to identify and quantify the sources of PM at Chennai; a metropolis in southern India. A total of 29 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Se, Sr, Te, Tl, V and Zn) and ten ions (Na⁺ , NH₄ ⁺ , K⁺ , Ca²⁺  , Mg²⁺, F^– , Cl^–  NO₂^– , NO₃ ^– and SO₄ ^2–) were analysed to find the chemical characteristics of PM₁₀ and PM_2.5. Four sources were identified for both PM₁₀ and PM_2.5. Vehicular pollution (11%), crustal source (27%), marine aerosol (40%) and industrial source (22%) are the sources identified for PM10. Vehicular emissions (32%), secondary aerosol (13%), marine aerosol (33%) and industrial source (22%) are the sources identified for PM_2.5.

5 illus, 21 ref

003348   ADATHODI L, MURUGADOSS J R, GADDAM K (Civil Engineering Dep, GMR Institute of Technology, Rajam-532127) : Characterization and feasible applications of waste tyre rubber deposits from airfield runway. Nat Environ Pollut Technol 2019, 18(2), 517-23.

The contribution of aviation industry in managing the time of travel around the world is overwhelming. Though its services are highly needed, the serious threat posed by the deposition of rubber during take-off and landing has to be addressed in the airfield runway to mitigate the ground-based accidents. As rubber is non-degradable in nature, the present work aims to study the use of aircraft tyre rubber waste in the removal of toxic metals like chromium from wastewaters and for partial replacement of sand in the production of rubberized concrete. The characterization of vehicular and aircraft tyre rubber waste shows that the siliceous material is equal and the presence of oxygen is observed in the aircraft tyre rubber waste compared to vehicular tyre rubber waste. The utilization of the aircraft tyre rubber waste for partial replacement of sand in the production of rubberized concrete showed that the slump values and compressive strength are decreased with an increase in the percentage of the tyre rubber waste and the acceptable limits are within 5% range. The removal efficiency of chromium from wastewaters using aircraft tyre rubber waste carbon (ATRWC) was obtained at 67.56% in a batch study for various parameters. From the results, it can be observed that ATRWC can be used as a low cost adsorbent for removal of chromium from wastewaters.

22 illus, 1 table, 17 ref

003406   QIN J Y, MA H H (Civil Engineering Dep, Henan Technical Coll of Construction, Zhengzhou 450064, China) : Ecological environmental pollution caused by construction engineering in china and relevant energy-saving and cost-reducing measures. Nat Environ Pollut Technol 2019, 18(2), 485-90.

Construction volume has been increasing significantly in the rapid urbanization in China, which causes evident ecological environmental pollution. Moreover, the construction industry is characterized by high energy consumption and high pollution. Therefore, the energy consumption of construction causes a considerably high proportion of the total energy consumption in the industry. Building energy efficiency is also key in the construction industry in China. In this study, ecological environmental pollution caused by construction engineering was further analysed. Results could provide reliable theoretical bases for the government to develop relevant policies on building energy efficiency. First, research on energy-saving and cost-reducing measures of construction engineering in foreign developed countries was reviewed. Second, types of ecological environmental pollution caused by construction engineering were summarized. Factors that could influence energy-saving and costreducing processes of construction engineering in China were also discussed. Finally, specific measures for energy-saving and cost-reducing processes of construction engineering were proposed. Results showed that foreign developed countries generally establish energy-saving and cost-reducing measures at the national level, thereby strengthening policy implementation. Ecological environmental pollution caused by construction engineering is caused by the large consumption of energy resources, contamination of urban public environment, occupation of land resources, damages to biodiversity, and influences to the normal living environment of residents. Faulty laws, regulations, and local policies on building energy efficiency; poor promotion and implementation of the government’s incentive measures; and lack of evaluation system and inadequate consciousness of building energy efficiency contribute to the energy conservation and cost reduction of construction engineering. This study suggests the development of policies on building energy efficiency, reduction of building energy consumption, promotion of building energy efficiency projects in China, and facilitating of new urbanization.

1 illus, 15 ref

003365   EMETERE M E, SANNI S E, OKORO E E (Mechanical Engineering and Science Dep, Johannesburg Univ, APK, South Africa) : Analysing the dangerous trends of air pollution over bo-sierra leone using fourteen years of aerosol optical depth data. Nat Environ Pollut Technol 2019, 18(2), 349-58.

The atmospheric air quality of a given location gives an indication of the health risks or exposures of the inhabitants of such a place. One major parameter for determining the amount of aerosols in an atmospheric region is the aerosol optical depth (AOD). It is a vital tool for predicting the air quality over a geographic enclave. In this paper, the pollution state of Bo-Sierra Leone was considered. Fifteen years primary (aerosol optical depth) dataset was obtained from a Multi-angle Imaging SpectroRadiometer (MISR). The secondary datasets that were generated from the primary data were aerosol loading, particle sizes, Angstrom parameter and the statistics of the primary dataset. The results obtained from the investigation are relevant for tackling the excesses that result from errors emanating from the instruments mounted on the ground for data generation. The years October 2001 and 2004 show similar Angstrom value (0.25) in the month of March 2008 but was highest (0.31) in the month of May 2009 followed by the value estimated (0.29) for October 2012; however, it was either lower or somewhat insignificant for other years. Aerosol loading was found to be constant and highest (0.9442) for the months of January-February, and May-November (2000). Years with higher aerosol loading were indicative of higher potentials for pollution relative to years of lower aerosol distribution/ concentration.

2 illus, 15 tables, 13 ref

003359   DARDOURI S, SGHAIER J (National Engineering Dep, School of Monastir, Tunisia, Monastir, Email: sanadardouri_en@yahoo.fr) : Modeling atmospheric emissions during olive husk drying and study of meteorological factors effect in the vicinity of urban areas. J Ind Pollut Control 2019, 35(1), 2236-43.

In this work, we present field measurement data and modeling of air pollutant during one season at an urban area in Sousse, east Tunisia. We analyzed the average pollutant emission and we used our data to evaluate a dispersion model. The impact of various meteorological factors on pollutants concentrations has been studied. The model predicts that the concentrations of CO and CO₂ in an urban area can reach 50 mg.m^-3 and 185 mg.m^-3 respectively. The height of the chimney, the wind velocity, the fuel nature, the air excess and the combustion temperature have an influence on the concentrations of pollutants and their dispersion.

7 illus, 4 tables, 37 ref