bluuebunny/crossref_metadata_2025 huggingface dataset:
Fire and legacy effects of logging on understorey assemblages in wet-sclerophyll forests
Authors: White Daniel J. , Vesk Peter A.
Published: August 2019

Wet sclerophyll forests of south-eastern Australia typically experience wildfire once or twice a century. However, disturbance regimes have changed drastically in recent decades due to clear-fell logging and altered fire regimes. To date, botanical research on disturbances in wet-forests has focussed on individual elements of disturbance regimes, such as intensity, at single points in time, largely neglecting past disturbance history. Studies of the impact of previous disturbance history on plant responses to successive disturbance events are important to our understanding of vegetation dynamics. Here we investigate the response of wet-forest understorey species to two important elements of disturbance regimes – timing and type – and trajectories of change in these vegetation communities. In surveys separated by 15 years over 128 sites, we recorded the frequency of occurrence of 21 understorey species from stands with disturbance histories ranging from 4 years post clear-fell logging to 150 years post wildfire. Approximately half our sites were burnt in the 2009 Black Saturday wildfires. This provided an opportunity to examine the effects of inter-fire interval and the legacy effects of clear-fell logging. Generalised linear mixed modelling showed that many of the species studied appear to be at risk of population decline as a result of clear-fell logging. Unlike wildfire, clear-fell logging led to changes in the understorey, having a long-lasting impact on the presence of key wet-forest taxa that rely on vegetative regeneration. These include large shade-bearing shrubs like Hedycarya angustifolia R.Cunn., Bedfordia arborescens Hochr. and Olearia argophylla (Labill.) Benth., which were resilient to recurrent wildfire but responded negatively to recent wildfire in sites with a history of clear-fell logging. Negative effects of a short inter-fire interval were limited to a few species.
Five-coordinate Mn
IV
intermediate in the activation of nature’s water splitting cofactor
Authors: Chrysina Maria , Heyno Eiri , Kutin Yury , Reus Michael , Nilsson Håkan , Nowaczyk Marc M. , DeBeer Serena , Neese Frank , Messinger Johannes , Lubitz Wolfgang , Cox Nicholas
Published: August 2019

Significance

Recent results have shown that nature’s water splitting catalyst inserts an additional water molecule into what appears to be a solvent inaccessible site late in its reaction cycle. The emerging consensus of the field is that this water molecule is one of the substrates of the reaction. Here, we show that this water molecule does not come directly from solvent. It instead represents an earlier bound water, which is inserted into this site via facile structural tautomerism. The trigger for this process is cofactor oxidation. This then allows an additional water to bind from solvent to a more open site of the cofactor. In this way the cofactor carefully regulates water uptake, preventing water insertion earlier in the reaction cycle.
Two types of magnetic shape-memory effects from twinned microstructure and magneto-structural coupling in Fe1+yTe
Authors: Rößler Sahana , Koz Cevriye , Wang Zhaosheng , Skourski Yurii , Doerr Mathias , Kasinathan Deepa , Rosner Helge , Schmidt Marcus , Schwarz Ulrich , Rößler Ulrich K. , Wirth Steffen
Published: August 2019

Significance

Magnetic shape memory (MSM) refers to a change in shape and/or size of a magnetic material upon applying a magnetic field. There are 2 types of MSM effects; the first one occurs in a twinned magnetically ordered material, in which the crystallographic axes are irreversibly reoriented by the applied magnetic field. In the second type, the applied field drives a magnetoelastic phase transition. In certain iron tellurides Fe1+yTe, both types of MSM occur. Notably, the first antiferromagnetic compound found to display an MSM effect is a parent material to the well-studied high-Tccuprate superconductor La2−xSrxCuO4. Observation of MSM effects in 2 known material families related to high-Tcsuperconductors points to a prominent role of electron–phonon coupling arising through the spin–orbit interactions.
Quantum effects in bi-dust plasmas
Authors: Puerta J , Martin P , Maass F , Blanco F
Published: August 2019

In this paper a theoretical approach has been carried out using a fluid model on a bi-dust plasma which consist of two dusts negative charged different particles in an electron–ion plasma. In such system, this fluid model describe a dense strong coupled heavy dust grain together with a weak coupled light dusty particle. The bulk is immersed in a system of electrons and ions dominated by a Thomas–Fermi density distribution, where interaction and propagation of solitary dust acoustic solitary waves will be analyzed. This investigation will be carried out for arbitrary amplitude of solitary dust acoustic waves. These are originated through the presence of both dust grains in the plasma system. Therefore, it is used a set of fluid equation which determine general expressions for the concentrations of different dust particles. The onset of the Sagdeev method is then employed in order to look for influence of the light component on the quantum system. In this way there is an increasing or decreasing in the Sagdeev potential. This is a quantum effect phenomena.
Homogenization of Grewia Optiva Fiber Reinforced Epoxy Composite Using Higher Order Shear Deformation Theory
Authors: Bhatt Piyush , Gadade Appaso M
Published: August 2019

The present work proposes a computational procedure for evaluating the homogenized property of laminated composite plate. This type of model is beneficial for determining the basic mechanical properties of a laminated composite with significantly lesser computational effort. In this work a formulation is presented which is based on Reddy’s higher-order shear deformation plate theory which takes into account the effect of transverse shear deformation in composite laminates. This method is capable of finding equivalent homogenized properties for the laminated composite having any type of lamination scheme. Further this formulation is used to homogenized property of Grewia optiva fiber reinforced epoxy composite with different volume fraction and lamina scheme are calculated by using the proposed formulation. The accuracy and validity of the present computational algorithm is ensured by comparing the results with the available literature which provides good results.
Estimation of interlaminar shear strength in glass epoxy composites by experimental and finite element method
Authors: Lakshmi P Rama , Devi P Anjani , Reddy P Ravinder , Yamuna K , Bharathi Y
Published: August 2019

The objective of the present work is to estimate interlaminar shear strength in glass epoxy composite by experimental and finite element method. A woven glass fabric (0°- 90°) and epoxy are used in the preparation of the composite. Interlaminar shear strength (ILSS) is estimated experimentally by ASTM D 2344 and ASTM C 1425 for thin and thick laminates. While adopting the procedure mentioned in ASTM D 2344, the sample dimensions of thin and thick laminate are 32 X 10 X 2 mm3 and 80 X 10 X 10 mm3 respectively. Three-point bend test is conducted on Universal testing machine made by United Calibration Corporation with model No. STM 50 kN at a loading rate of 1.5 mm/minute. For the standard ASTM C 1425, the sample dimensions of thin and thick laminate are 30 X 15 X 2 mm3 and 30 X 15 X 10mm3 respectively. The fixture is fabricated for both thick and thin laminate for estimating interlaminar shear strength. The obtained experimental results are compared with interlaminar shear strength estimated in ANSYS, and the correctness of finite element analysis is verified. The results interpreted in the present work are also compared with the published results available in the literature, and it is noticed that the deviation is agreeable. From the available literature, it is also suggested that ASTM C 1425 is recommended over the other methods since the sustainability of the material is achieved while examining the interlaminar shear strength.
Estimation and Analysis of Cooling Load for Indian Subcontinent by CLD/SCL/CLF method at part load conditions
Authors: Acharya K G , Yewale G P , Tendolkar M V , Kulkarni S H
Published: August 2019

A total equivalent temperature difference (TETD) and cooling load temperature difference (CLTD) methods are developed in the excel spread sheets using Visual Basic Programming for calculating the cooling load for a building. The spread sheets are developed to eradicate the human error and time consuming task of manual calculations. TETD and CLTD methods programmed in spread sheets are easiest and fastest way to estimate the cooling loads as compared to that of the commercially available software’s. The TETD method estimates the peak value of the cooling load and CLTD is used to estimate the cooling load on an hourly basis. Cooling loads estimated using TETD method and CLTD method are validated against CARRIER software HAPv4.9. However, there is a marginal difference in the obtained cooling load values of the spread sheets and HAPv4.9. For selecting the air conditioning equipment for a building, the accurate cooling load calculations are required. For peak cooling load, the solar peak time at a given location is required. The present work deals with the analysis of Solar Peak Time for Indian Sub-Continent, by varying the solar time and geographical directions. The variation patterns as a result of heat gains due to occupants, equipment and lighting in the building are analysed on hourly basis using the CLTD method. Similarly, the variation patterns of cooling load due to variation in outdoor dry bulb temperature and relative humidity are obtained for different cities across India by considering the same room psychometric conditions, internal loads and maximum solar peak time. The TETD method always over predicts the estimated cooling load.
Maintenance priorities determination for a repairable unit of a sugar plant
Authors: Sharma Gaurav , Tewari P C
Published: August 2019

In the present study, a repairable unit of a sugar plant has been considered to determine the maintenance priorities of various subsystems of the unit. The selected repairable unit is crushing unit and it comprises of crusher, inter carrier and pump subsystems. Performance modeling of the unit is based on Markov approach. From the transition diagram of the unit, Chapman-Kolmogorov differential equations are derived. The equations are then solved to get the availability in steady state. It is assumed that all subsystems have constant rates of failure and repair. After that, development of decision matrices has been done for all subsystems. For various permutations of failure rates as well as repair rates, these decision matrices present different levels of availability for all the subsystems. On the basis of various values of availabilities and the graphs of failure and repair rates of subsystems, the optimum values of failure and repair rates are selected for maximum availability of each subsystem. Accordingly, priorities for maintenance are determined for various subsystems of repairable crushing unit. This will ensure maximum availability level of the crushing unit and will finally lead to the overall performance enhancement thereby maximizing the profitability of the plant.
Numerical analysis of gasoline fuel with laser ignited spark ignition
Authors: Patil S S , Nandgaonkar M R
Published: August 2019

Laser ignition overcomes the problem of faster degradation of electrodes using high energy required for lean burn and reduced heat loss to the electrodes. A number of investigations have been carried out on laser ignition of gaseous fuels but the work, on laser ignition of liquid fuels is indeed very limited. In present work, a Multi-dimensional CFD model using ANSYS Fluent 17.2 was developed for constant volume combustion chamber (CVCC) to characterize laser ignition combustion phenomenon from the start of plasma formation to end of combustion. The combustion and emission characteristics of gasoline-air mixture ignited by laser-induced spark were studied using numerical simulation. It was predicted from results obtained from numerical results that peak pressure goes on increasing with the increase in equivalence ratios from 0.8 to 1.4. The numerical simulation results obtained were in good agreement with experimental results of literature with 10.6 % percentage error, which demonstrates that the model developed is valid for the combustion process. The trends of the NOX, CO, CO2, emissions were analyzed using a numerical model.
Optimization of process parameters of microwave processed PLLA/coir composites for enhanced mechanical behavior
Authors: Singh Manoj Kumar , Verma Nishant , Zafar Sunny
Published: August 2019

In the present work, poly-L-lactide (PLLA)/coir-based polymer composites were fabricated by a novel manufacturing route of microwave processing. Microwave processing is faster and cleaner process as compare to conventional manufacturing processes. The effect of microwave temperature, time and fibre weight reinforcement was evaluated for their mechanical behaviour using uniaxial tension and flexural tests. The full factorial design was used to optimize the process parameters for enhanced mechanical performance of the composites. The analysis of results was done on Design Expert V.10 software. PLLA/coir composite processed at 140 °C for 12 min having fibre weight percentage of 30% has maximum tensile strength of 18 MPa. The maximum flexural strength 48 MPa reported was for the same specimen having maximum tensile strength. The optimized value of process parameters obtained was, processing temperature: 140°C, time 12 min and coir reinforcement percentage of 30%. The fractured specimens were characterised using scanning electron microscopy to support the results.
Experimental heat transfer coefficient during condensation of R-410A in horizontal micro-fin tubes
Authors: Singh S , Kukreja R
Published: August 2019

Condensation heat transfer coefficient has been calculated experimentally in microfin tubes of outer diameter 9.52mm with helix angles 15° and 18°. Condensation of refrigerant R-410A include mass fluxes from 200 to 600 kg/m2s, vapour qualities between 0.1 to 0.9 and saturation temperature at 35 °C and 40°C. The experimental results indicate that the average heat transfer coefficients of R-410A in micro-fin (MF) tubes were increased 1.15-1.47 times larger than those of smooth tube (ST). The experimental results are compared with the existing correlations of heat transfer coefficient proposed by other authors. The comparison indicated good agreement with these existing correlations within ±30%. A correlation has also been developed for predicting condensation heat transfer coefficient in micro-fin tubes.
Design and analysis of progressive tool for an automobile component
Authors: Chavan Harshal A , Wani Vijay P
Published: August 2019

Dies are used in forming industries from several years, especially for sheet metal. Progressive dies are forming tool which involve in performing more than two different operations at working stations. The finished product is obtained from the raw material by forming from first station to last station. To design and develop various components in metal forming is very complicated task. Current study is focused on design and develop a progressive die to manufacture tail gate striker used in head lamp assembly, which previously manufactured using different dies. Progressive die uses low cost standardise tools for improvement in production. Progressive die leads to various uncertainties, which results in manufacturing loss of component. Based on the experience of the designer, it is require to identify the risk and resolve the same at the time of design. Use of CAE in designing and developing the progressive die for automobile component is discussed in brief with analysis. Use of progressive die results in maximum usage of raw material to manufacture the desired component. With use of progressive die, overall rate of production increases with less labour cost.
Elastohydrostatic simulation of thrust bearing Compensated with orifice restrictor operation with non-Newtonian lubricant
Authors: Yadav Saurabh K , Ram Nathi , Sharma Satish C
Published: August 2019

In the present work influence of elastohydrostaic lubrication on orifice compensated bearing has been shown. The thrust pad has been modeled by using three-dimensional mesh and lubrication domain has been modeled by using two dimensional mesh. The analysis of Reynold equation is coupled with the analysis of solution of equilibrium equation of thrust pad domain. The Present results shows that elasticity of thrust pad results a significant decrement in the fluid film Elasticity and it results an increase in fluid film stiffness. In the present case Circular, Elliptical, square and rectangular shape of recess has been taken from the analysis.
Integration of solar charged PCM storage with VAR system for low capacity vegetable cold storage
Authors: Awasthi Rajeev , Chattopadhyay Suman , Ghosh Sudip
Published: August 2019

In this work a solar-assisted vapour absorption refrigeration (VAR) system, suitable for 10 MT vegetable cold storage for a small village, has been modelled and analysed for day-night operation. Solar parabolic trough collector (PTC) has been considered for integration with a LiBr-H2O based VAR system. Thermal energy from solar thermal system is stored in a phase change material (PCM) energy storage, which is integrated with the VAR system. Apart from system integration, operational strategy of the storage based system has been evolved and performance of the system on hourly basis for representative days has been reported. The PCM quantity and the number of PTC modules have been decided based on the cooling demand. Hitec salt has been considered as PCM material. The study reveals that 5 PTC modules, each of 30 m2aperture area, and a PCM mass of 12.5 ton can effectively cater the energy demand of the VAR system to successfully maintain the 10 MT cold room at 6 °C.
A Level Set Approach for Dynamics of Flow in Accelerating Rectangular Container
Authors: Senapati J R , Moulic S Ghosh , Roy S
Published: August 2019

The level set approach is a numerical technique to capture the interface for a system of two immiscible fluids separated by a sharp interface. Since the interface is captured by an implicit function using this approach, this is a Eulerian formulation of the evolution of interface. The different fluids must be identified by using a marker function, called the level set function that takes different values in the various fluids. The present work uses a level set approach for modeling the dynamics of flow and the shape of the liquid free surface in a partly filled rectangular tank which is subjected to an impulsive motion from rest. The governing equations are written about a non-inertial frame attached to the container in motion. Extremely high viscosity and density ratios of the two immiscible fluids make the problem more challenging. The surface tension forces are ignored in this study. The signed distance property of the level set function is retained by using the reinitialization algorithm. In the present study, we have compared the computed shapes of equilibrium free surface with theoretically predicted shapes at equilibrium.
Design and Development of Spin Welding Machine for Thermoplastics
Authors: Bindal Tarun , Saxena Ravindra K. , Pandey Sunil
Published: August 2019

A new indigenous spin welding machine for thermoplastics with advanced mechatronic controls is conceptualised, designed in detail and a prototype is developed for joining of two thermoplastic parts in axis-symmetrical fashion. Manual spin welding machines for joining thermoplastic parts in axis-symmetrical manner are generally obtained by modifying drill type machines which causes the relative frictional rotation of parts under contact pressure exerted manually through a lever. The contact under relative motion causes the heat generation and results into fusion of parts. The joints from such machines exhibit inconsistency inherent in the manual process. The indigenous prototype machine is able to perform spin welding process with consistency. It enables the operator to choose and control the process parameters such as rotation velocity, time of rotation, spin pressure and cooling pressure.
Heat transfer studies for the design and optimisation of a distillation column to separate an automotive fuel
Authors: Iqbal A , Ahmad S A
Published: August 2019

Methylal, an automotive fuel has been noticed as a diesel alteration additive with relatively high hydrogen-to-carbon ratio. Methylal is more volatile than diesel fuel but it is used as a diesel fuel component because of its 100% miscibility with diesel fuel. An attractive feature of methylal is the reduction of particulate emissions of toxic pollutants without affecting the energy density. Unfortunately, methylal is found to form a minimum boiling azeotrope with methanol whose separation by conventional distillation is impossible. Here, we have introduced an enhanced technique of pressure swing distillation which separates methylal and methanol by exploiting its pressure sensitivity. This work has addressed the design and optimisation of a pressure swing distillation column to separate the azeotropic mixture of methylal-methanol. A novel technique of pressure swing distillation has resulted in the production of pure methylal and pure methanol. The pressure in high pressure column of pressure swing distillation process has been optimised in such a way that there is minimization of overall cost of the process with maximization of product purities. Later on, a process intensification technique of heat integration has been developed which has resulted in 55.2% savings in energy by reducing the overall load of reboiler.
Analysis of frictional heating and thermal expansion in a disc brake using COMSOL
Authors: Bashir Masrat , Qayoum Adnan , Saleem Shahid
Published: August 2019

This work illustrates the modeling of frictional heating in a disc brake of a car using COMSOL Multiphysics software. Finite element analysis technique is used to predict the frictional heat, temperature distribution and variation in disc thickness of the disc brake. The parameters for the disc and pad were selected from the existing literature. A three dimensional model of disc brake has been created and simulated. The model simulates the dynamics and frictional heating between pad and disc. The frictional heat is computed in the multibody dynamics module of the COMSOL while as temperature distribution is computed by the heat transfer module. Also stresses and disc thickness variation is computed utilizing solid mechanics module. The results obtained from the simulation provide a clear justification of the use of the COMSOL Multiphysics for the evaluation of frictional heat and thermal expansion.
Influence of cutting fluid conditions on tool wear and surface roughness in hard turning AISI-D2 Steel using mixed ceramic tools
Authors: Junaid Mir M. , Wani M.F , Banday Summera , Parveez Bisma
Published: August 2019

In the present work, the effects of machining factors and cutting fluid flow conditions on tool wear and surface roughness were studied. Response surface methodology technique with Face centered composite design was employed to minimize the number of experiments. The experiments were performed on a hardened AISI D2 rod using mixed ceramic (Al2O3/TiC) inserts in turning process. The effect of machining time was found to be the most influential parameter affecting tool wear, followed by cutting speed. However, machining time followed by feed rate were the most significant parameters on surface roughness. Moreover, cutting fluid condition showed substantial contribution towards decreasing tool wear rate and increasing surface finish.
Investigation of thermal and electrical performance in a salt gradient solar pond
Authors: Goswami Rohtash , Das Ranjan
Published: August 2019

The performance of a salt gradient solar pond (SGSP) invariably depends on the properties across its various zones. This paper presents an experimental study of salt diffusion, electrical and thermal performance of a trapezoidal-shaped SGSP. The variations of various parameters such as salt concentration, temperature gain, electrical conductivity (EC), thermal conductivity, density, specific heat and total dissolved solids (TDS) are studied across different zones of SGSP. This study reveals that for a given level of solar insolation, the rate of temperature gain within the lower convective heat zone (LCHZ) is high during the initial stages of operation where the salt diffusion rate is slow. Temperature gain of 16.06° is observed during a month comprising both rainy and sunny days. Within LCHZ, it is found that thermal conductivity, density and specific heat depend strongly on the salinity and their dependence on the temperature is relatively weaker. However, the effect of temperature on these three parameters is observed in the upper convective cold zone (UCCZ). Additionally, in UCCZ and LCHZ, TDS and EC depend on both salinity and temperature. The present observations are proposed to be useful in applications related to solar pond based desalination and energy generation.
Influence of eccentricity ratio on stability performance of hydrodynamic conical journal bearing
Authors: Gangrade A. K. , Phalle V. M. , Mantha S. S. , Siddiquee A. N.
Published: August 2019

Due to growing need of conical journal bearings for combined axial and radial load application, efforts are being made to explore suitability of various shapes of hydrodynamic conical journal bearings. The combined load carrying ability of conical journal bearings appear as a better option to employ in rotary-machines and added applications. Thus, in this research work, efforts have been made to explore the stability performance of hydrodynamic conical journal bearing by finite element analysis. The bearing performance have been examined for semi-cone angle (γ= 5°, 10°, 20°) and eccentricity ratio (ε) up to 0.6 for rotor speed (v= 2.6, 5.2m/s). Results are presented for axial and radial load capacity, stiffness and damping constants and rotor threshold speed. Load carrying capacity is improved with semicone angles and journal operating speed. Stability performance of bearing as a threshold speed(ω¯th)decreases with increase of semi cone angle. Hence, selection of journal operating speed and semi-cone angle is significant for dynamic stability of conical journal bearing.
An evaluation of tactile frictional behavior of the wooden material
Authors: Jain P , Srivastava A K , Rathore J S , Shrivastava S
Published: August 2019

Skin tribology and contact mechanics have emerged as a recent topic of research, intended to unveil the behavior of human skin. There have been variegated efforts to calculate the coefficient of friction with respect to various parameters such as sliding speed, normal load, and surface roughness. Wood and other timber products have their importance considering the ergonomically designs that have gained importance nowadays. This article shows the relation between normal load, average sliding speed and coefficient of friction (μ) of various types of woods (Rosewood, Sunmica, Teak wood and Pine wood). An experimental investigation is conducted to understand frictional behavior between human skin and different types of woods. Wooden material has been tested with the normal load having the range of 6.5N to 13N. The variation of μ has been remarked as μrosewood>μpine>μteak>μsunmica. Experimental observation shows that the rosewood has the highest COF which suggests its application where grip and strength of high order are required.With decreasing sliding speed, the relation between normal load and μ become more significant.
Friction and Wear Properties of Si3N4/TiC Ceramic Composite under Nano Lubrication
Authors: Kumar Sanjay , Wani M. F. , Sehgal Rakesh , Mushtaq S.
Published: August 2019

The present research evaluated the tribological behavior of Silicon Nitride based composite reinforced with 1 wt. % of Titanium Carbide under dry and lubrication conditions. The lubricant base oil used in this study is 85W140; with nanoparticles additives poly tetra flouro ethylene and Copper (PTFE & Cu) Nanoparticles were added in the base oil to review the performance of the nanoparticles as additives. Ball-on-disc wear tests were conducted to explore the effects of Nano additive in lubricant for ceramic-ceramic tribo-pair. Results showed that friction and wear decreased using nanoparticle in the lubricant oil, as compared to, dry as well as base lubricant oil conditions. It was reported that 0.1 wt. % of PTFE Nano particles and 0.3 wt. % of Cu Nano particles shows minimum value for the coefficient of friction (COF). Rheological studies were also done on these lubricants samples. The findings from the present work encourage the modification of nanoparticle based lubricant to improve the friction and wear properties and to improve the life of the component.
ASSESEMENT OF MACHINING PARAMETERS ON EN-24 STEEL UNDER DRY, WET AND MQL CONDITION USING MULTI COATED INSERTS
Authors: Gupta Shrajal , Chandra Vaibhav , Kumar Praveen
Published: August 2019

The minimum quantity lubrication is an interesting possibility for an economical and environmentally compatible production, which unifies the functionality of coolants and lubricants with mightily less consumption of lubricants. In this experiment, minimum quantity lubrication setup on turning machine was design and developed for comparison between dry and wet conditions and their effects are considered under different parameters. This setup uses mist/flood formation of lubricants with the help of minimum quantity lubrication. This strategy is used to improve machining of the product surface quality during turning operation. The surface roughness value has been taken as an output response; the surface roughness value of the machined part was evaluated using Talysurf surface roughness tester. The design of experiment was enacted on Taguchi’s orthogonal array L9 to optimize the selected process parameters during turning of EN-24 under different conditions. The Grey relational method was also applied for optimizing purposes. The optimum conditions include a cut 0.6 mm deep, a nose radius of 0.8mm and a cutting speed of 575 rpm and the depth of cut was found out to be most dominant parameter. MQL shows better results in terms of surface roughness as compared to dry and wet conditions.
Evaluating the grinding ratio and surface quality of Ti-6Al-4V under varying grinding pass count and depth of cut
Authors: Raj Rai Bishan , Mukhopadhyay Manish , Kumar Kundu Pranab
Published: August 2019

Surface finishing of advanced difficult-to-machine materials through grinding is posing a significant challenge to the manufacturing industries. However, one of these materials, Ti-6Al-4V has a significantly high usage in several cutting-edge sectors. Thus, finding optimum grinding conditions for processing of this material becomes critical. Present article represents an experimental investigation dedicated towards analysing the effects of varying grinding pass counts and infeed values on the surface roughness, hardness, visible surface burns and grinding ratio of Ti-6Al-4V applying alumina wheel. Experiments are performed to reveal the trend of the surface properties and hardness of Ti-6Al-4V, ground at 10 μm and 20 μm infeed values with different sets of grinding passes. The results indicate that grinding at 15 pass count under 10 μm and 20 μm infeed values are the ideal set of parameters for the operating ranges considered herein.
Stability Analysis of Dual-rate Haptics Controller Using Two Control Architectures
Authors: Ganiny Suhail , Koul Majid H , Ahmad Babar
Published: August 2019

Digital implementation of uniform-rate haptics controller limits the range of virtual environment parameters that can be stably implemented, particularly at higher sampling rates. Dual-rate sampling scheme alleviates this limitation and enlarges the range of these parameters that can be stably implemented. In this paper, theoretical stability analysis of the dual-rate haptics controller is presented using two control architectures. Analytical conditions that guarantee the closed-loop stability of the system are developed using linear control theory tools. The stability criteria constrains the virtual environment parameters as a function of the ratio of sampling periods of the controller, and thereby establish limits on the performance of these controllers. The developed criteria can be seen as the generalization of existing criterion available in the literature.
Finite Element Modelling of Cutting Forces in Face Milling of Duplex Stainless Steel 2205
Authors: Sambedana Soumya , Jagadeesha T
Published: August 2019

Duplex Stainless Steels are one of the newest pioneers in the world of super alloys. They exhibit a unique combination of high strength and corrosion resistance and hence are currently giving a strong competition to other nickel based alloys and titanium alloys. Due to the excessive alloying of DSSs, they have a very poor machinability, as result of which the cutting forces associated with machining is very high. In this work, a 3D Finite Element Modelling of cutting forces in milling of DSS 2205 has been developed using FEM software package ABAQUS Oblique cutting has been used so that inaccuracies due to the assumptions in orthogonal machining are avoided. The developed FEM model has been validated experimentally by conduction a series of milling tests. The model results showed close agreement with the experimental results and the forces values were found to be affected most by feed rate. As feed rate per tooth increases, the forces components were also found to be increasing both for experimental and model values.
Knee torque estimation in sit to stand transfer
Authors: Bhardwaj S , Khan A A , Muzammil M
Published: August 2019

Multi-body formulations of human body has been a major approach in biomechanics to study the kinematics and dynamics of human movements. This paper discuss an inverse dynamics model of human body for the estimation of knee torque requirement during a sit to stand (STS) transfer. The study was carried out in two parts. In the first part of the study, angular deviations of trunk and knee were recorded in the sagittal plane, while one participant performed STS transfer. In the second part of the study, a five segment human model was designed in SolidWorks and later analysed in MSC/ADAMS for computation of knee torque in STS transfer. The maximum knee torque was found to be 1.34 Nm/kg at 59.2° knee extension.
Mechanical suitability of carbon fiber based composite for chopart prosthetic socket
Authors: Abdulsadah F H , Murtaza Q , Hasan F , Bhardwaj S
Published: August 2019

Material selection has important role in the design of prosthetics. Presently, polyethylene (PE) has been majorly used in the manufacture of chopart prosthetic socket due to it mouldability and low cost, but suffers from large weight to strength ratio. In the present study, carbon fiber composite (CF) is compared with PE for its usability in chopart prosthetic sockets. 3 perlon layers-2 carbon fiber layer-3 perlon layers (3P-2C-3P) lamination was developed and tested for the mechanical properties. Later, the tested mechanical properties of PE and CF were used in finite element modelling to analyze stresses and deformation in the Chopart prosthetic socket. The study showed that use of CF in chopart prosthetic sockets reduces stress by 70.6% as compared to PE, and could be suggested as mechanically superior material in design of chopart prosthetic socket compared to PE.
Multi-Optimization of Process parameters for Inconel 718 While Die-Sink EDM Using Multi-Criterion Decision Making Methods
Authors: Sharma Vikas , Prakash Misra Joy , Singhal Piyush
Published: August 2019

The objective of the paper is to apply Multi-criterion Decision Making methods in manufacturing specially in machining using EDM and to obtain an optimal setting of process parameters resulting in an optimal value of the material removal rate and tool wear rate while EDM for Inconel 718 using copper cadmium as electrode Taguchi L9 array has been used to design the experiments, the results are further analyzed using Multi-criterion Decision Making techniques named Technique for order preference by similarity to ideal solution TOPSIS and Preference Ranking Organization Method for Enrichment of Evaluations (PROMETHEE) to investigate the multi-optimization of response characteristics for Inconel 718.
Experimental investigation of an ejector refrigeration system using R-134a
Authors: Kumar Vikas , Sachdeva Gulshan
Published: August 2019

In the present study, the performance of ejector refrigeration system is investigated using R-134a as working fluid. Six ejectors of different geometries are used to experimentally evaluate the coefficient of performance, cooling capacity, pressure lift and critical condenser pressure for fixed generator and evaporator temperature, while varying the condenser temperature. It is observed that an optimum area ratio of the ejector is required to obtain better performance and is found that a higher value of area ratio gives maximum COP for the specified conditions but for a lower value of critical condenser pressure. The critical condenser pressure for the ejector of area ratio 10.08 comes out to be 778.9 kPa whereas it is 916.72 kPa for the ejector of area ratio 6.451 while working at generator and evaporator temperature of 80 °C and 15 °C respectively. Further, the ejector having a shorter length of constant area section is found to excel. It is also concluded that for lower evaporator pressure, higher pressure lift is obtained from the same ejector.
Soil degradation determines release of nitrous oxide and dissolved organic carbon from peatlands
Authors: Liu H , Zak D , Rezanezhad F , Lennartz B
Published: August 2019

Carbon (C) and nitrogen (N) release from peatlands are closely related to water management and soil degradation. However, peat degradation has not been explicitly accounted for when estimating national greenhouse gas inventories. Here, we assembled a comprehensive dataset covering European, Russian and Canadian peatlands and introduced soil bulk density (BD) as a proxy for peat degradation to estimate nitrous oxide (N2O) and dissolved organic carbon (DOC) release. The results show that physical and biogeochemical properties of peat are sensitive to soil degradation. The BD is superior to other parameters (C/N, pH) to estimate annual N2O emissions and DOC pore water concentrations. The more a peat soil is degraded, the higher the risk of air/water pollution in peaty landscapes. Even after rewetting, highly degraded soils may exhibit high N2O release rates. The estimated annual N2O–N emissions from European, Russian and Canadian degraded peatlands sum up to approximately 81.0 Gg. The derived BD-based functions can assist in computing global matter fluxes from peatlands.
A global decarbonisation bond
Authors: Leiss William
Published: August 2019

The 2018 IPCC Special Report, Global Warming of
1.5
°C, calls attention to the inadequacy of ‘the current nationally stated mitigation ambitions as submitted under the Paris Agreement’ to control global warming within acceptable parameters. A strategy of decarbonisation is urgently required in this context, and where that strategy is most needed is in developing countries, which are, however, constrained by a shortage of capital to carry it out. This paper proposes that developed countries implement their promised $100 billion annual assistance to developing nations by issuing, by 2023, a $2.5 trillion Global Decarbonization Bond that will front-load the provision of appropriate technologies for this purpose.
Egg production and quality of local female chicken by dietary self-selection reared under semi-scavenging system in the tropics
Authors: Syafwan  , Noferdiman
Published: August 2019

The feeding standard for local chicken breeds in Indonesia has not been published yet. The present study were aimed to measure egg production and quality while estimating the ME and CP needs during production for local female chickens reared under semi-scavenging system in the tropics (Indonesia) through dietary self-selection. A total of 138 twenty two week-old chicks were randomly distributed into 12 sheltered pens, 10-14 birds each. Two feeding methods (control and self-selection) were assigned to pens, so each treatment consisted of 6 replicates. The control group received a control diet complying with the Hy-line Brown Nutrient Requirements Standard, whereas the self-selection group had access to the control and four other diets (high energy-high protein, low protein-high energy, high protein-low energy, and low protein-low energy diet). Feeds and drinking water were provided ad libitum to 53 weeks of age. Feed consumption (FC), CP intake, ME intake, concentration of dietary CP and ME and egg production were recorded weekly. Egg quality was measured three times. Daily temperature and relative humidity in the morning (07:00), noon (12:00), and afternoon (17:00) were 21.8 to 28.1°C and 46 to 88%; 24.7 to 34.5°C and 35 to 72%; and 23.5 to 34.5°C and 36 to 80%, respectively. Data were analyzed using Proc Mixed of SAS, but egg quality was analyzed by ANOVA. The results showed that feeding method had apparent effect on CP intake (P=0.018) and ME intake, dietary concentration of CP and ME, egg production (P<0.001) but not on FC. The effect of week and feeding method by week interaction were also very significant for all performance, except egg production was not affected with feeding method by week interaction. Weekly CP and ME intake of the self-selection group were greater than those of the control (105.8 vs. 101.3 g/bird; P=0.018 and 1,709 vs. 1,575 kcal/bird; (P<0.001), respectively). Dietary concentrations of CP and ME in the self-selection group was higher (P<0.001) than those in the control group (189.3 vs. 180.7 g/kg and 3,053 vs. 2,810 kcal/kg, respectively). Egg production of the self-selection group was higher (P<0.001) than those of the control (60.5% vs. 55%). Over all, egg quality (eggshell thickness, shell strength, shell weight, egg weight, Hmm, color, compare, HU, and yolk weight) was similar, except color and compare were higher in choice-fed birds when they grew older. Local female chickens were able to select diets to adjust their nutrient requirements by selecting more of an energy-rich diet and less of a protein-rich diet. CP and ME requirement by local female chickens were more likely greater than the current formulated for them in order to increase egg production.
Physicochemical properties and total plate count of raw salted eggs with blanching and different concentration of aloe vera solution during the salting process
Authors: Novia D , Juliyarsi I
Published: August 2019

Salted egg is a typical popular snack in some societies in Indonesia. However, it contains high NaCl and cholesterol. One way to cope with it is by utilizing aloe vera which has the chemical composition of a complete and well-known traditional medicine. The purpose of this study is to determine the physicochemical properties and the bacterial colonies forming raw salted eggs with different temperature and concentration of aloe solution for 5 days salting process. This study used 2×3 factorial design with three replications, factor A (without blanching and blanching) and factor B concentration of aloe vera solution (2, 8 and 14%). According to the research, there was an interaction between the process of the different heating and concentrations on NaCl, yolk and albumen pH, cholesterol and total plate count raw salted eggs were produced. The heating process of aloe vera increases the content of NaCl, albumin pH, cholesterol and bacterial colonies formed. Treatment with blanching at 14% concentration effectively produced lowest moisture content, yolk pH, cholesterol, and highest ash content, NaCl content, Albumen pH, total solids and total plate count the best raw salted eggs.
Vibration Characteristics Analysis and Optimization of Trawler Propulsion Shafting System
Authors: Sial T R , Jin Y , Juan Z
Published: August 2019

The propulsion shafting system enables power delivery from the main engine to the propeller and plays a vital role in promoting the motion of the ship. The increase in demand for trawlers in coastal areas has led to the increase in the need for an improvement in its performance. Therefore, while trawling at sea, vibration characteristics are essential in analyzing for the safe and efficient functioning of the propulsion shafting of trawler ship. The primary objective of this paper is to model, analyze and reduce the vibration characteristics of trawler propulsion shafting. A computational model has been modeled and analyzed by Modal Analysis using Finite Element Method, focusing on the Lateral Vibrations. The natural frequencies, mode shapes, and the maximum deformation with affected zones of trawler propulsion shafting are evaluated. The attempt has been made to reduce the vibration characteristics of trawler propulsion shafting by the optimization process considering the design parameters whereby, it comes in the acceptable range for normal operation. The results of analysis and optimization have been computed and discussed.
A New Type of Energy Absorbing Structural Component: Spiral Thin-Walled Tube
Authors: Zuo Qiyang , Zhang Feifei , He Kai
Published: August 2019

Various thin-walled (TW) tubular components have been widely applied to absorb impact energy due to their sound crashworthiness and long stroke. This paper presents a novel spiral TW tubular component used for absorbing energy. The presented TW structural component is easily prepared and cost-effective because it can be handily manufactured by sheet metal rolling. Its geometry structure on cross section is spiral so it is called spiral TW tube in this work, which was studied by formulation method. Furthermore, its dynamic crushing and energy absorbing characteristics under impact loading was investigated by means of simulation analysis. The analysis result shows that the presented spiral TW tube has a superior energy absorbing performance and is promising used in passive safety area.
Remaining Useful Life Prediction of Cutting Tools Based on Support Vector Regression
Authors: Liu Y C , Hu X F , Sun S X
Published: August 2019

Remaining useful life (RUL) prediction of cutting tools is critical to effective condition based maintenance for reducing downtime, ensuring quality and avoiding accidents. In this paper, a RUL prognostic method based on support vector regression (SVR) is proposed for predicting cutting tool’s life. The proposed method consists of two main phases: an off-line phase and an on-line phase. In the first phase, the signal features are extracted from raw data, and then the SVR models with considering different length of signals at past times are established to reflect the relationship between monitoring data and tool life. In the second phase, the constructed models are used to predict cutting tool’s RUL, and the best signal length for accurate prediction result is obtained. The proposed method is applied on experimental data taken from a computer numerical control (CNC) rotor slot machine in a factory. The result shows the validity and practicability of this method.
The Irrigation Uniformity Analysis Based on Translation Variable-Rate Sprinkler
Authors: Run Yan
Published: August 2019

Research and compare various modeling of three-dimensional model, the paper chooses CATIA software to model the translation irrigation machine, and analyzes its working principle, structure, mode of operation and obtains to various parts of the structure size parameters, organize and remove redundant parameters, to facilitate the establishment of the model. We proposed here two indexes which were spray shape and water distribution uniformity to evaluate hydraulic performance of variable-rate sprinkler. And analyzed the influence of the throw radius caused by working pressure, nozzle area and trajectory angle. By calculating instantaneous application rate, it is indicated that the irrigation uniformity will go bad when change single factor to accomplish variable-rate irrigation.