bluuebunny/crossref_metadata_2025 huggingface dataset:
Mode demultiplexing of vector beams using crossed-fork-shaped polarization grating fabricated by photoalignment of photo-crosslinkable liquid crystal polymer
Authors: Sakamoto Moritsugu , Kaneko Yusuke , Nakamoto Yuki , Noda Kohei , Sasaki Tomoyuki , Kawatsuki Nobuhiro , Ono Hiroshi
Published: August 2019

A crossed-fork-shaped polarization grating (crossed-FPG) is presented for use in vector beam division demultiplexing. The crossed-FPG was fabricated in a thin photocrosslinkable liquid crystal polymer film by recording multiple polarization holograms between optical vortices and Gaussian beams that have opposite circular polarizations to each other. The recorded holograms work individually to act as FPG with a polarization-dependent topological charge conversion property that corresponds to a recorded pair of vortices. The feasibility of mode demultiplexing was demonstrated experimentally. The proposed crossed-FPG should be used as a mode demultiplexer for optical communications based on vector beam division multiplexing.
Piezo-electrical control of gyration dynamics of magnetic vortices
Authors: Filianina M. , Baldrati L. , Hajiri T. , Litzius K. , Foerster M. , Aballe L. , Kläui M.
Published: August 2019

In this work, we first statically image the electrically controlled magnetostatic configuration of magnetic vortex states and then we dynamically image the time-resolved vortex core gyration tuned by electric fields. We demonstrate the manipulation of the vortex core gyration orbit by engineering the magnetic anisotropies. We achieve this by electric fields in a synthetic heterostructure consisting of a piezoelement coupled with magnetostrictive microstructures, where the magnetic anisotropy can be controlled by strain. We directly show the strong impact of the tailored anisotropy on the static shape of the vortex state and the dynamic vortex core orbit. The results demonstrate the possibility of using electric field induced strain as a low-power approach to tune the dynamical response of magnetic vortices.
Two-site versus continuum diffusion model of blocker dynamics in a membrane channel: Comparative analysis of escape kinetics
Authors: Berezhkovskii Alexander M. , Dagdug Leonardo , Bezrukov Sergey M.
Published: August 2019

This paper deals with the escape of a charged blocker molecule from a voltage-biased membrane channel with a constriction zone which the molecule cannot pass through. Recently, we developed a two-site model of the blocker dynamics in such a system and applied it to analyze the escape kinetics. Here, we compare the decay of the blocker survival probability predicted by the two-site model with that for the survival probability given by a more accurate model which assumes continuum diffusion of the blocker molecule inside the channel. The main finding of the present work is that both models predict the same decay of the survival probability at long times. This result is of practical importance since only the long-time tail of the survival probability can be studied in single-channel experiments in which, due to a limited time resolution, only long-lasting individual events of channel blockades can be measured.
Kinetic and dynamic studies of the H3+ + CO → H2 + HCO+/HOC+ reaction on a high-level ab initio potential energy surface
Authors: Zhu Yongfa , Tian Li , Song Hongwei , Yang Minghui
Published: August 2019

The proton transfer reaction H3+ + CO → H2 + HCO+/HOC+ is of great importance in interstellar and circumstellar environments. The dynamics and kinetics of the reaction were studied using the quasiclassical trajectory approach on a newly developed ab initio potential energy surface (PES) for the ground electronic state. The PES was constructed by fitting 46 462 ab initio points at the level of CCSD(T)-F12a/aug-cc-pVTZ using the fundamental invariant-neural network method. The calculated product branching ratio, scattering angular distribution, and thermal rate coefficient agreed reasonably well with the experimental measurements, which were rationalized by the underlying reaction mechanisms.
The evolution of dispersal traits based on diaspore features in South American populations of Senecio madagascariensis (Asteraceae)
Authors: Dematteis Bruno , Ferrucci María S. , Coulleri Juan P.
Published: August 2019

Plant invasion success is influenced by several driving factors such as the dispersal, environmental conditions and the species characteristics. In wind dispersed plants, the dispersal traits and the altitude are key for predicting dispersal ability. In this work, we estimated this feature in Senecio madagascariensis invasive populations from Argentina and Brazil using diaspore traits to understand its dynamics. Our results show that dispersal is strongly affected by the geographic conditions. We observed that in Argentinian populations growing at higher altitudes, selection favours larger seeds, which might favour seedling establishment over of longer dispersal distance. Conversely, populations grouped in lower altitudes show higher dispersal ability, probably due to the adaptation to environment and assortment of the better dispersal genotypes. In contrast, the Brazilian populations display rapid dispersal ability due to recent colonisation and multiple introductions. The variability in the gene pool could facilitate the occurrence of genotypes with greater dispersal, which could explain why these populations display greater dispersal ability than the Argentine ones. In conclusion, the phenotypic response to geographic conditions and the population density play an important role in the dispersion strategies in S. madagascariensis.
Dichotomy of the photo-induced 2-dimensional electron gas on SrTiO
3
surface terminations
Authors: Rebec Slavko N. , Jia Tao , Sohail Hafiz M. , Hashimoto Makoto , Lu Donghui , Shen Zhi-Xun , Moore Robert G.
Published: August 2019

Significance

Titanates are a group of oxide materials which are heavily studied due to their wide array of interesting physical properties. Here, we study the origin of one particular property, the 2-dimensional electron gas (2DEG), by growing SrTiO
3
and other titanate films with different surface terminations, using atomic layer-by-layer growth and probing their electronic structures. Surprisingly, we only observe the 2DEG on the A-site termination and not on the B-site termination. We use this dichotomy to help understand the origin of the 2DEG and suggest how this same methodology could be applied to other oxide systems.
Protective Factors in Violence Risk Assessment: Predictive Validity of the SAPROF and HCR-20V3
Authors: Neil Clare , O’Rourke Suzanne , Ferreira Nuno , Flynn Liz
Published: August 2019

Research and practice in violence risk assessment in forensic mental health primarily focuses on risk factors; however consideration of protective factors may improve the accuracy and utility of assessments. Using a pseudo-prospective design, the predictive and incremental validity of protective factors was explored using the Structured Assessment of Protective Factors (SAPROF) and Historical Clinical Risk Management-20 (HCR-20V3) in 75 male inpatients in a secure setting. Over a 12-month period, protective factors significantly predicted the absence of inpatient (institutional) violence and risk factors, particularly dynamic factors, predicted the presence of violence. Hierarchical logistic regression did not establish the incremental validity of the SAPROF. Preliminary evidence for the predictive and incremental validity of the Integrative Final Risk Judgment was found with individuals judged high risk being almost seven times more likely to engage in violence than those assessed as moderate risk. High risk ratings were associated with fewer protective factors and more risk factors. Therefore, whilst dynamic risk factors are clear targets for risk management, consideration of protective factors may contribute to overall estimates of risk and provide additional targets for intervention.
Results of the CCRI(II)-S12.H-3 supplementary comparison: Comparison of methods for the calculation of the activity and standard uncertainty of a tritiated-water source measured using the LSC-TDCR method
Authors: Cassette Philippe , Altzitzoglou Timotheos , Antohe Andrei , Rossi Mario , Arinc Arzu , Capogni Marco , Felice Pierino de , Galea Raphael , Gudelis Arunas , Kossert Karsten , Lee K B , Liang Juncheng , Nedjadi Youcef , Verdecia Pilar Oropesa , Shilnikova Tanya , Wyngaardt Winifred van , Ziemek Tomasz , Zimmerman Brian
Published: August 2019

A comparison of calculations of the activity of a 3H2O liquid scintillation source using the same experimental data set collected at the LNE-LNHB with a triple-to-double coincidence ratio (TDCR) counter was completed. A total of 17 laboratories calculated the activity and standard uncertainty of the LS source, using the files with experimental data. The results, as well as relevant information on the computation techniques are presented and analysed in this paper. All results are compatible, even if there is a significant dispersion between the reported uncertainties. An output of this comparison is the estimation of the dispersion of TDCR measurement results when measurement conditions are well defined.

KEY WORDS FOR SEARCH

Radionuclide metrology, supplementary comparison, tritium, liquid scintillation

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Effect of sequencing rules on order release policies in a stochastic and dynamic job shop with sequence-dependent setup times – a simulation study
Authors: Rani Sushma , Jain Ajai , Angra Surjit
Published: August 2019

Order review and release in job shop with sequence-dependent setup times is one of the most complex job shop scheduling problems. This article analyses the effect of sequencing rules on different order release policies for performance measures i.e. mean throughput time, total setups, mean setup time, number of tardy jobs and makespan in a stochastic and dynamic job shop with sequence-dependent setup time. Four sequencing rules, viz. first-come-first-serve, planned release date, earliest due date, shortest processing time and five order review and release policies i.e. aggregate workload trigger, workcentre workload trigger, corrected workload trigger, upper bound release and lancaster university management school corrected order release are taken into consideration. A simulation model using Promodel®is developed for experimental purpose. Results indicate that for a given order review and release policy, there is an effect of sequencing rule in a stochastic and dynamic environment with consideration of sequence-dependent setup time and the best performing sequencing rule is different for different order review and release policies for a given performance measure.
Effect of piston ring geometries on lubrication and friction in diesel engine
Authors: Pachaiyappan Ilanthirayan , Thamildorai Nobel , Mani Kalayarasan
Published: August 2019

Lubrication and friction in piston rings are of a greater importance which has been receiving significant attention from tribologists for a long time. The main subsystems which contribute to friction include the ring-pack/liner, piston-skirt/liner, piston-pin/connecting-rod and connecting rod-crankshaft bearings. Piston rings are used in engines mainly to reduce leakage of gas in the combustion chamber and simultaneously provide a lubrication film in order to reduce friction during its motion. Wear between piston rings and liner is inevitable and therefore in order to reduce it, different types of ring geometries are being used which has its own advantages and disadvantages. Another major problem being faced during operation is that oil from the liner gets transported by pumping, reverse blow by, inertia and squeezing of oil due to ring dynamics into the combustion chamber. The present work focuses on to investigate different ring geometries and their effects on friction and lubrication oil consumption. It was found that Tangential force has an inverse relationship with Oil Film Thickness and Oil filling ratio. Top ring friction is high at Top dead centres due to boundary lubrication. Ring Barrel height has a direct relationship with asperity friction and an inverse relationship with Oil Film Thickness. Axial width is directly proportional to the wear of rings, which is due to the area exposed to back pressure on the rings exerted by gases from combustion chamber. Second ring closed gap has a direct relationship with Inter-ring pressure thus increasing reverse blowby. Rings with a Positive twist are found to be stable during operation. For this analysis, AVL Excite software is being used and results are validated with an experimental model.
Response of Laminated Composite Cylindrical Shell Using Higher Order Shear Deformation Theory
Authors: Suryawanshi Aniket A , Gadade Appaso M
Published: August 2019

The present work proposes the response of composite laminated cylindrical shell using higher order shear deformation theory (HSDT). For the finite element formulation a displacement field having five degrees of freedom is considered and a nine noded isoparametric element is used. The finite element model is developed using MATLAB code. The numerical results are obtained for the deflection of cylindrical shell for arbitrary boundary condition, stacking angle and radius to thickness ratio. The results are validated using literature and it shows good agreement
Simulation and Experimentation of Single Point Incremental Forming of Different Geometries
Authors: Gaira Sukrit , Theja V Sai , Karthikeyan G.
Published: August 2019

Incremental Sheet Forming is a rather new forming process which is used to obtain complex three dimensional parts by stretching the sheet with a pin tool whose path is controlled by a CNC machine. This study presents a new fixture design for Single Point Incremental Forming (SPIF) and experiments conducted for two profiles. Single Point Incremental Forming is used for small and batch production. The fixture presented in this study was made using mild steel which can be used for performing multiple forming purposes. The circular profile and a square profile were generated using a spherical head tool of 5mm diameter made of Stainless steel and the results were compared with that of Simulations for the same profiles using the analysis software, ABAQUS. The experiments were carried out using Computer Numerical Control (CNC) machine.
Starting Characteristic of Supersonic Mixed Compression Air Intake with Cowl Porosity
Authors: Gahlot N K , Singh N K
Published: August 2019

The present study is aimed towards the investigation of starting characteristic of supersonic air intake by adopting the cowl porosity. A computational study has been performed with k-omega turbulence model adopting the RANS solver. Air Intake shows the unstart phenomenon for the clean model case and this could be due to large shock wave boundary layer interaction near the throat. After implementing the cowl porosity, intake shows the starting behavior and there after a compression in the flow is observed. It also improves the quality of flow and performance of supersonic air intake. The obtained result have been validated with the previously published data. All the calculations were performed at design Mach no of 2.2 for free flow conditions.
Process parameter optimization of dmls process to produce AlSi10Mg components
Authors: Shah R K , Dey P P
Published: August 2019

AlSi10Mg components were produced by Direct Metal Laser Sintering (DMLS) and its physical properties like density and mechanical properties ultimate tensile strength were measured.The experimental analysis showed that energy density and hatch spacing are the vital factors influencing the density of the components, the range of energy density for obtaining the best result was 42.40-63.25 J/mm3.The most important parameter effecting the Ultimate Tensile Strength (UTS) was Laser Power but Hatch Spacing also had an equal importance on the tensile strength but energy density analysis revealed that the highest energy density did not gave the least value of UTS as it was in the case of density.The optimum process parameter for both density and UTS was found to be a Laser Power of 330 W,Scan Speed of 1200 mm/s and Hatch Spacing of 0.15 mm.
Sustainable supplier selection for battery manufacturing industry: A MOORA and WASPAS Based Approach
Authors: Jayant Arvind , Chandan Aditya Kumar , Singh Shweta
Published: August 2019

The aim of present research work is to hybrid the “MOORA and WASPAS” MCDM methods in the sustainable vendor’s selection & evaluation decision. It also considers the feedback impact of the decision on strategic variables that determine the future viability of the case company in the competitive business environment. MCDM strategic decision framework is applied that considers simultaneously the influence of criteria and sub-criteria on the sustainable vendor evaluation decision. The developed framework is evaluated, and criteria weight is determined using the step-wise weight assessment ratio (SWARA) method. The MOORA & WASPAS consider the influence of criteria, sub-criteria and their interdependencies simultaneously in the system. The results of the model is the relative priorities ad ranking developed for the suppliers. The present research has been conducted in a battery manufacturing company of Punjab state of India. The influence of dimension of sustainability dimensions would be widespread due to the big market in which the case company operates. The outcome the present work can provide support to the managers who are decision makers in the industries. The framework present in the research arriving at an optimal sound decision considering all sustainability applicable dimensions. The novelty of the approach lies in the use of different MCDM model integrating the dimension of sustainability with a feedback effect for vendor selection. The industry would be benefited by showing its commitment toward social responsibility, environment management, and economic aspects leading to improved market image and profitable business with sustainability.
Multi-response Optimization using TGRA for End Milling of AISI H11 Steel Alloy Using Carbide End Mill
Authors: Singh Pradeep K , Saini Pardeep , Kumar and Kanish
Published: August 2019

The AISI H11 steel is an important material used for making tools & dies. Machining is a very important activity in manufacture of tools & dies where the surface finish and metal removal rate play a very vital role. This paper presents the influence of the cutting speed, feed rate and depth of cut in end milling onto the surface roughness (SR) and metal removal rate (MRR). The machining experiments have been carried out on CNC vertical milling machine. Taguchi grey relational analysis (TGRA) with standard L27 orthogonal array has been selected to investigate the connection for studying surface roughness and metal removal rate (MRR). Both the responses viz. surface roughness and material removal rate are assumed to have equal weightage (W1 = W2 = 0.5) considering general machining conditions. The model significance tests have been conducted using ANOVA to find out which factors are statistically significant. The percentage contribution of cutting speed, feed rate and depth of cut are 29.13 %, 40.93 % and 17.4 % respectively. Optimization has been carried out to get optimum combination of SR and MRR.
Numerical experiments of flux difference splitting methods with high resolution scheme for supersonic flows
Authors: Rajput Uttam Singh , Singh Krishna Mohan
Published: August 2019

In this work, we have carried out the assessment of a high resolution scheme for unsteady compressible flow. For high order spatial accuracy, we have used fifth order weighted essentially non oscillatory (WENO) scheme. This scheme is applied to four flux difference splitting (FDS) methods: Harten-Lax-van-Leer (HLL), Roe solver, Harten-Lax-van Leer-Contact (HLLC), and Rusanov methods. We have compared results of these flux schemes with each other. WENO scheme is used for the reconstruction of left and right state variable across the cell interface for high resolution. The reconstruction procedure is performed in terms of primitive variables instead of conservative variable, in order to avoid spurious oscillation. We have considered two test cases: shock wave reflection and supersonic viscous flow over a flat plate, to access the performance of FDS schemes. An explicit third order TVD Runge-Kutta method is used for advancement of solution in time. The present results are compared with available numerical solutions. WENO-HLLC has good shock capturing capabilities as compare to WENO-Roe, WENO-HLL and WENO-Rusanov methods. It also provides best results inside and outside the boundary layer.
Improvement in Manufacturing System by Rearrangement in Layout Design – A Case Study
Authors: Singh Shivam , Khanduja Dinesh
Published: August 2019

Market demands are rising deliberately. Continuous modification in design with improved features has become a necessity to survive in the present competitive market. This throughout adaptation of new features and techniques is a great challenge to the manufacturing system. It is tough call for any firm to organise its layout against the change in design and type of product. The change in layout is tedious and costly for small scale industries with job shop system. Thus, improvement in facility layout should be such that it is easily flexible to the changed scenario. Also it should enhance productivity by reducing the distance flow, lead time and wastage. A case study was carried out at a job shop production industry- Bluebird Lights Pvt. Ltd. Delhi, India. After the analysis of the present layout, a revised layout plan was optimised for its variety of products being manufactured.
An Intelligent Simulation based case study of Indian Micro Small Medium Enterprise (MSME) of farm equipment manufacturing
Authors: Sharma Janpriy , Jayant Arvind
Published: August 2019

The manufacturing field is the area where application of simulation is an essential tool for validating the methods and architecture before applying them to factory shop floor. In this paper an Indian Micro Small Medium Enterprise (MSME) is taken into consideration, which manufactures agricultural equipment’s with aim to mechanise the Indian farming techniques. Presented case study is authentic and adopted for Gahir Agro Industries situated in agricultural hub, state of Punjab. Proposed company is all set to launch a new farm equipment called ‘Laser Land Leveller’ which got approval from governing body and ready for its batch production because of seasonal demand. Present study encapsulates the modelling and simulation as tool for analysis of manufacturing process of laser land leveller and its predicted production levels under actual working conditions. Tool used for modelling and simulation is ARENA 15.1 by Rockwell Automation Studio.
A pilot study on thermal comfort in Indian Railway pantry car chefs
Authors: Alam M S , Arunachalam M , Salve U R
Published: August 2019

An Indian railway pantry car kitchen is a typical kitchen, where involves various kinds of thermal environment factors. Till now, the research related to pantry car kitchen is rarely reported. Therefore, this pilot study explores the thermal environmental factors and its impact on the chef’s comfort in two different pantry car kitchen (Non-AC and AC) using a subjective and physical measurement technique. The thermal comfort level was quantified by Predicted Mean Vote (PMV) Index and Predicted Percentage Dissatisfied (PPD) Index. The thermal sensation of non-air-conditioned pantry cars was hot with PMV and PPD values are 2.93 and 99% respectively. Whereas, air-conditioned pantry cars was a warm thermal sensation with PMV and PPD values are 2.17 and 84% respectively. Moreover, most of the chef (86%) are perceived thermal discomfort in both pantry car kitchens. The result concluded that both types of pantry car kitchens are having thermal sensation effect of hot and warm. A further detail study is necessary and a possible design intervention may require to enhance thermal comfort of chefs.
Empirical modeling of cutting speed during WEDM of nimonic 263
Authors: Singh B , Misra J P
Published: August 2019

Cutting speed (CS) is a main process performance measure parameter of WEDM process. CS is mainly affected by input process parameters of WEDM and hence production and machining efficacy. Therefore, it is essential to pick the optimal combination of input parameters to get better CS. In this study, four parameters; Spark on (Son), Spark off (Soff), servo voltage (Sv), and peak-current (Ip) were selected for developing an empirical model of CS during WEDM of nimonic 263. Total 81 samples were machined on different WEDM parametric conditions based on three level full-factorial design of experiment with one replication of each run. This paper describes user-defined RSM based mathematical modeling for predicting optimal parametric setting for cutting speed. Furthermore, analysis of variance (ANOVA) was applied to find significant parameters and it was depicted that Son and Ip were the key parameters affecting average CS.
Design, Modelling and Manufacturing of 16 Cylinder Hydraulic Fixture with Automated Clamping System
Authors: Dhulia Jaykumar K , Maniar Nirav P
Published: August 2019

The function of a jig and/or fixture (fixturing system) is to hold a workpiece firmly in position during a manufacturing process. It is seeming that almost all the literature of fixture is focused on principles and theoretical aspects of fixture design. This raises a question of the practical value of fixture research. There is a clear demand for designing and manufacturing fixture for real industrial component and more research in computerized fixture design in such fields. The present research work satisfies this demand by deploying the fixture design task into an overall manufacturing process to obtain best fixture design solution for real industrial component. The component is rear flange of gear case widely used in automobile industry, made up of cast iron. The major operations to be performed are drilling and milling. The research includes design and manufacturing of a fixture with automated clamping system, which provides location and clamping arrangement for machining 4 components in one cycle on VMC 640 of pallet size 800 mm x 500 mm. Machine tools, material handling devices, transport and other mobile equipment, aviation systems, etc. do use hydraulic systems, butapplication of hydraulic principles in fixture is of uncovered area till now. This paper includes designing and manufacturing 16-cylinder hydraulic fixture with automated clamping system for machining rear flange on VMC. The important details of the part and fixture are included in each section along with 2D drawing and 3D view of finished component and fixture assembly using Creo 2.0.Fixture is not only designed but manufactured also, it sets the classical example of design for manufacturing.
Tribological Behaviour of Graphene Coated Bearing Steel (EN31)
Authors: Moharana R , Sengar S S , Badhan B , Rao U S , Gautam R K , Tyagi R
Published: August 2019

The present investigation is on the tribological behaviour of graphene coated bearing steel (EN31). Though bearing steel has excellent mechanical properties but its wear properties are inadequate. To enhance its wear properties, bearing steel was coated by graphene. Graphene is a very unique and peculiar material. It has excellent mechanical, chemical, electrical, magnetic and optical properties. Furthermore, it is light in weight which makes it one of the most sought after materials in the research world. To improve the adhesion property between graphene and bearing steel, bearing steel was first coated with nickel using electroplating technique. Then graphene was coated by CVD technique. To analyse the characteristics of graphene, Raman spectroscopy was carried out. The friction and wear tests were performed at constant load of 1 N and different speeds of 0.05 m/s, 0.075 m/s and 0.1 m/s for the tribological analysis of the materials. After wear, the worn out surfaces were further investigated by using scanning electron microscope (SEM). From the present investigation it has been observed that coated bearing steel shows improved tribological characteristics.
Process Parameter Optimization of Ultrasonic Assisted Electrochemical Magnetic Abrasive Finishing of 316L Stainless Steel
Authors: Farwaha Harnam Singh , Deepak Dharmpal , Brar Gurinder Singh
Published: August 2019

There is requirement of advancements in the machining processes able to achieve better surface finish in tight tolerances. It is not always easy to produce work piece characteristics in order to fulfill the listed requirements by only using the traditional finishing processes. Ultrasonic assisted electrochemical magnetic abrasive finishing (UEMAF) is a hybrid micro machining process and finish surfaces of hard and brittle materials up to nano meter scale. UEMAF integrates the use of electrochemical machining, ultrasonic vibrations and magnetic abrasive finishing. Taguchi technique is used to find optimal process parameters of Ultrasonic assisted electrochemical magnetic abrasive finishing (UEMAF). A L9 Orthogonal array, applied to analyze the effect of ultrasonic assisted electrochemical magnetic abrasive finishing process parameters (rpm of work piece, % wt. of abrasive and ultrasonic frequency time) on percentage improvement in surface finish (PISF).
Experimental investigations of TIG welding based additive manufacturing process for improved geometrical and mechanical properties
Authors: Gokhale Nitish P. , Kala Prateek , Sharma Varun
Published: August 2019

The welding based additive manufacturing process has a potential for producing functional 3D metallic component in a cost effective manner. Out of many welding based alternatives available TIG (Tungsten Inert Gas) based additive manufacturing process is one of the efficient processes. This article aims at developing TIG welding based additive manufacturing process for producing metallic parts with improved geometrical and mechanical properties. In this work authors have identified a process parameter condition by which components with good geometrical properties can be produced. The work reports least bead width deposited, for 1.2 mm filler wire, using wire arc based additive manufacturing system. The study performed on residual stress analysis of the deposited material showed compressive residual stresses throughout the sample. Usually welding process produces tensile stresses in the specimen which may reduce the product life. The compressive stresses reported in this study are considered good as they tend to increase product life. Authors have also addressed the reason for this unusual but favourable behaviour. This work would also help to develop automated TIG welding based metal deposition system to produce thin walled structures with improved mechanical and geometrical properties.
In-plane vibration of curved beams subjected to moving loads using finite element method
Authors: Poojary Jatin , Roy Sankar K
Published: August 2019

In-plane vibration of curved beams caused by loads moving at constant velocity is studied by means of finite element method. Curved beam elements incorporating shear effects by means of first order shear deformation beam theory are used for this purpose. Damping effects are assumed to be negligible. The vibration response of the curved beam under loads moving at a constant velocity along the beam is found and compared with that obtained using ANSYS to validate the study.
Barium titanate particle filled silicone elastomer composite: Preparation and evaluation of morphology and mechanical behaviour
Authors: Kumar Ajeet , Ahmad Dilshad , Patra Karali
Published: August 2019

Barium titanate (BaTiO3) nano particles with different percentage by weight were added in silicone rubber as a filler to develop silicone elastomer composites. The morphology of the fractured surface of the prepared silicone elastomer composite film was investigated to see the distribution of BaTiO3 nano filler in the polymer matrix. The obtained results showed good distribution of BaTiO3 up to 10% by weight in silicon elastomer composite. Beyond this 10% weight percentage, agglomeration of BaTiO3 particles occurs. The mechanical characterizations of silicone elastomer composites with different weight % of BaTiO3 particles were performed through uniaxial tensile testing. Elastic modulus of composite increases when filler content increases up to 10%. However, further increase in the filler content results agglomeration of particles in the composite and decrease in elastic modulus of the silicone elastomer composite. The results show that the optimum value of filler content in the prepared composite is between 5% to 10%.
Numerical study on the thermal behavior of polymer nano-composites
Authors: Arora Gaurav , Pathak Himanshu
Published: August 2019

In this work, Mori-Tanaka (MT) scheme has been implemented to predict effective thermal properties of polymer nano-composites composed of high-density polyethylene (HDPE) and single-walled carbon nano-tubes (SWCNTs) as matrix and nano-fillers, respectively. The technique uses the fourth order tensor to effectively determine the thermal conductivities, specific heat and global density of the composites. Effect of constituent’s volume fraction and orientation have been investigated for effective thermal conductivities of composites. The composite fillers are numerically simulated as aligned, 2-D and 3-D random orientation in the polymer matrix. Numerical results show that in-plane and out-of-plane thermal conductivities have a linear relation with increasing volume fraction. The specific heat capacity of a composite decrease as the volume fraction of SWCNTs increases. The randomly distributed SWCNTs decreases the heat flux whereas the alignment of SWCNTs has shown a maximum heat flux.
Experimental analysis of WEDM machined surface of Inconel 825 using single objective PSO
Authors: Kumar P , Gupta M , Kumar V
Published: August 2019

The present research focuses on the analysis of surface topography of Inconel 825 superalloy, machined with Wire Electrical Discharge Machining. Surface texture analysis includes cracks, craters, pockmarks, heat affected zone and recast layer thickness. Particle swarm optimization used response surface methodology (RSM) to find the optimum combination of WEDM characteristics viz. pulse on time, pulse off time, gap voltage, peak current, wire tension and wire feed. Surface crack density (SCD) and recast layer thickness (RCLt) are the output responses. The results manifest that pulse on time, peak current and gap voltage are the most influential parameters for surface topography. At optimum combination of process parameters, the value obtained for SCD is 0.000423 μm/μm2 and RCLt is 8.044 μm. Under optimized conditions, surface topography of the machined specimen is improved that makes it suitable for implementation in industry.
Experimental modelling of powder metallurgical processed copper foams using acrawax as a space holder material
Authors: Sharma Mohit , Angra Surjit
Published: August 2019

Copper foams have various uses in applications such as electrode for fuel cells and batteries, filters for water purification, thermal conductivity enhancer for phase change materials, etc. This study shows the process of processing copper foams with an average pore size of 200-300 μm with 40 and 70 volume % porosity through a powder metallurgy route. Space holder technique has been employed to process the copper foams. A lubricant space holder material acrawax has been used which possesses superior properties compared to all the previously used space holders. Copper foam’s physical and mechanical properties have been studied with the change in compaction pressure. Simple mathematical models have also been developed in this work using 2N factorial method. The models can be used to get the values of pore size and porosity present in the foams according to the changing parameters like amount of space holder, compaction pressure, sintering time and temperature.
Three-Dimensional Unsteady Wake Characteristics of Rectangular Cylinder
Authors: Kumar Prashant , Tiwari Shaligram
Published: August 2019

Present study investigates three-dimensional flow field characteristics for flow past surface mounted finite height rectangular cylinder using Open Source Field Operation and Manipulation (OpenFOAM). Wake characteristics have been examined for different values of Reynolds number (Re) ranging from 140 to 200 and fixed height of the cylinder. Different values of side ratio (SR, ratio of longitudinal dimension to transverse dimension of the cylinder) have been considered varying from 0.5 to 3.0 for Re = 180. Effect of Re on unsteady wake flow has been presented using iso λ
2 -surfaces. Unsteady periodic oscillation and effects of Re and SR on wake transition have been illustrated using Hilbert spectra of the transverse velocity signals in the wake. Wake shedding frequency and its distribution in energy frequency domain have been presented and analysed using marginal and Fourier spectra. Comparison between the two spectra reveals that marginal spectra extract lowest frequency which is not captured by Fourier spectra. Extent of nonlinear fluctuations in the wake and its distribution with the associated frequency have been analysed and quantified in terms of degree of stationarity. Variation in mean drag coefficient with change in Re and SR has also been reported.
Household LPG Cylinder: Effects of different heads and Impact analysis using ANSYS
Authors: Mahraur Nikhil Kumar , Singh Nilamber Kumar
Published: August 2019

The aim of this paper is to study the behaviour of a gas-filled LPG (liquefied petroleum gas) cylinder having dissimilar heads (hemispherical, semi-ellipsoidal and tori-spherical) and its responses subjected to vertical (at the top) and horizontal (side) normal impacts by a solid spherical steel ball of mass 4 kg at different velocities 5, 25 and 50 m/sec using ANSYS. The technical specifications of the gas cylinder necessary for its design calculations are referred from Hindustan Petroleum Corporation Limited (HPCL). The conventional steel is considered as the material for both the cylinder and the impacting ball under the critical gas pressure of 2.5 MPa as per Indian standard, IS 6240. Effects of the critical gas pressure on the cylinders are studied based on the thickness as well as the strength for above heads. The simulated results of ANSYS have good agreement with the theoretical results.
Selection of optimum Cutting Parameters for Minimization of Specific Energy Consumption during Machining of Al 6061
Authors: Pawanr Shailendra , Garg Girish Kant
Published: August 2019

Manufacturing sector consumes a significant amount of energy globally. Machine tools are one of the major equipment in manufacturing sector and hence major consumer of energy. The electrical energy consumed by the machine tools results in emission of harmful gases and substantial stress on environmental. This work focuses on selection of optimum cutting parameters to minimize specific energy consumption (SEC) during turning of Al 6061 with tungsten carbide inserts in dry condition. Experiment are planned using L27 orthogonal array and Taguchi method is applied to determine optimum and most influencing cutting parameters for minimizing SEC. Results shows that feed is the dominating factor followed by cutting speed and depth of cut. The optimum value of feed (mm/rev), cutting speed (m/min) and depth of cut (mm) are found 0.12, 46.2 and 1.0 respectively. Further the energy consumption maps are developed to analyse the influence of cutting parameters on specific energy consumption. The developed energy consumption maps can be used for correlating the region of minimum SEC with selected cutting parameters.
Sensor fusion model for defect identification in friction stir welding process
Authors: Das Manabendra , Meena Ashish , Das Bipul
Published: August 2019

Defect identification in friction stir welding process is a challenging task as most of the defects formed at subsurface level. The available non destructive approaches are limited only to offline assessment of the defects. In automated environment defect identification methodologies with online monitoring possibilities are gaining significant attention. In this research work sensor fusion based model has been developed for identification of tunnel defect in friction stir welding samples. Real time signal information acquired from tool main spindle motor current signal, rotational speed and vertical force signal have been fused to estimate a quantitative indicator for defect detection within the welded samples. Real time signals are acquired using a force measurement system and a speed sensor with a sampling frequency of 10 kHz. Feature level fusion modeling is incorporated to develop a methodology for defect detection in friction stir welding process. The estimate can be used for identifying defective samples from defect free samples which is advantageous in automated production environment.
Comparative analysis of Silica-gel/Water and Zeolite/water Pair on adsorption Refrigeration System
Authors: Soni Palash , Gaba Vivek Kumar
Published: August 2019

The current work presents a comparative investigation on the execution of closed cycle adsorption refrigeration systems with Zeolite as adsorbent and water as adsorbet in one system and silica-gel as adsorbent and water as adsorbate in another system. In the present analysis, the effect of variation of the regeneration temperature on the coefficient of performance (COP) along with specific cooling power (SCP) for both the pairs has been studied and compared. From the analysis, it was found that specific cooling power (SCP) and coefficient of performance (COP) for Zeolite/water pair are better at a lower range of regeneration temperature while it is not that good for silica-gel/water pair. Both the pairs perform well at higher regeneration temperature. This being a theoretical study the results may vary practically.
Mathematical Modelling and Comparative Study of Elliptical and Circular Capacitive Pressure Microsensor
Authors: Mishra Rishabh Bhooshan , Santosh Kumar S.
Published: August 2019

A lot of work on clamped circular, square and rectangular shaped capacitive pressure sensor has been carried out. However, to the best of our knowledge, no elaborate work has been performed on mathematical formulation and simulation of clamped elliptical shaped capacitive pressure sensor in literature. This paper describes the mathematical modelling and simulation of normal mode clamped elliptical shaped capacitive pressure sensor. The study of various performance parameters like maximum diaphragm deflection, capacitance variation, mechanical sensitivity, capacitive sensitivity and non-linearity is also carried out for operating pressure range of 0kPa – 18 kPa. For circular capacitive pressure sensor, the operating pressure range is modified according to physical dimensions i.e. thickness and radius of diaphragm, separation gap between plates and maximum deflection. For same overlapping area between plates (10000π mm2), the comparison of elliptical shapes of different eccentricities with circular shape diaphragm is carried out. The thickness of diaphragm is taken as2 μm and separation gap is 1 μm in all the designs which are used in this work. In this comparative study, it is observed that elliptical shaped capacitive pressure sensors have better linearity than circular diaphragm pressure sensor.
Experimental investigation on performance and emission characteristics of single cylinder CI engine using waste cooking oil (WCO) with diethyl ether (DEE)
Authors: Jagotra A , Singh D K , Sandhu S S , Kango S , Bhadauria S S
Published: August 2019

The objective of this paper is to investigate the performance and emission characteristics of WCOME (waste cooking oil methyl ester) blended with DEE (diethyl ether). The present work deals with the utilization of waste cooking oil (WCO) as feedstock for biodiesel production via transesterification process by using an alkali catalyst (KOH – 1.5 wt. %) with alcohol (methanol) under molar ratio (1:6). The concluding properties of WCOME like viscosity, density, flash point and cv were fitured by ASTM/EN standard and were resulted to be equivalent to ASTM/EN standard for diesel. Various test fuels were prepared for the engine trials by blending 10%, 20% and 30% of WCO biodiesel in diesel on volumetric basis and cognominated as diesel-biodiesel blends (B10,B20&B30 respectively) and also added 5% DEE (as an additive) in same diesel-biodiesel blends on volumetric basis and designated as diesel-biodiesel-DEE blends (B10DEE5, B20DEE5 & B30DEE05 respectively). Among all the tested blends in this study, it was observed that addition of 20% WCO biodiesel (i.e. B20 & B20DEE5 blends) spectacle the best-improved results at the full load as compared to diesel fuel, with and without the addition of 5% DEE. For 20% biodiesel blends (i.e. B20 & B20DEE5 blends) at the full load, BTE was found to be increased by 3.50 % without DEE and 0.5 % with 5% DEE addition respectively, BSFC decreased by 20.83% & no change with 5% DEE, EGT decreased by 13.33% & 8.13% with 5% DEE, NOx decreased by 9.69% & 8.59% with 5% DEE, HC decreased by 27.59% but increased by 17.24% with 5% DEE, CO does not show any change at full load, SO decreased by 49.24% & 64.89% with 5% DEE & decreased by 98.04% using DPF with 5% DEE and the CO2 was increased by 1.89% & 3.77% with 5% DEE as compared to diesel fuel. Hence, 20% biodiesel blending shows the best performance and emissions results as compared to diesel fuel.
Optimizing pulsed fiber laser welding process parameters of thin Ti6Al4V sheet to control angular distortion
Authors: Maji Kuntal
Published: August 2019

The present study deals with angular distortions generated in fiber laser welding of Ti6Al4V sheets performed utilizing pulsed mode of laser irradiations. Experiments were conducted considering laser power, scan speed, pulse frequency and duty cycle as input process parameters, and angular distortion measured in terms of out of plane bending was taken as the process output. A central composite design was employed for carrying out pulsed laser welding experiments. The angular distortion was modelled using the response surface methodology for correlating with the input process parameters. Angular distortion was observed to increase with the laser power and scan speed. Optimum values of laser pulse frequency and duty cycle were found for obtaining least angular distortion. The prediction accuracy of the developed model of angular distortion was found to be good. Then, the desirability function approach of optimization technique was used to determine the optimum process parameters for obtaining the minimum distortion. Optimal distortion value was verified by conducting experiments and results were found satisfactory.
Effect of Mast Modification in Ingress Problem in Gas Turbine of Naval Ship
Authors: Yadav P S , Saxena V , Pali H S , Kumar N , Singh S N
Published: August 2019

Over the years, these funnels which were tallest structure on ships are no more the tallest structures and are now dominated by masts which have various electronics and antenna’s. This change has resulted in to smoke ingress problem. The gas turbine intake is located close to the funnels. The smoke entrapped in the wake of masts gets sucked in the intake of the turbine thereby raising the temperature at the intake resulting in lowering the efficiency of gas turbine. The flow and performance characteristics for a simplified model are carried out by providing opening in mast structure of different shapes to see the effect on smoke ingress problem.