bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyzing vocational school students’ error in solving mathematics problems involving higher order thinking skills
Authors: Baskoro I , Retnawati H 
Published: November 2019

Abstract
Higher-order thinking skill is conceived as the top end of Bloom’s cognitive taxonomy. Cognitive domain of higher order thinking skill consists of analyzing, evaluating, and creating. The study aimed to describe the type of error made by vocational school students in solving problems involving higher order thinking skills based on Newman, Lai, Subanji & Mulyoto. This study employed a qualitative descriptive approach with a test as data collecting technique. The respondents are 12 students of vocational school. The skill domain of analyzing contributes reading & decoding error, comprehension error, conceptual error, process skills error, and encoding error. The highest percentage of students’ error in this domain is conceptual error (33%). The skill domain of evaluating contributes decoding & reading error, comprehension error, language interpretation error, process skills error, and encoding error. The highest percentage of students’ error in this domain is encoding error (25%). The skill domain of creating contributes conceptual error, comprehension error, and process skill error. The highest percentage of students’ error in this domain is conceptual error (42%). The results suggest mathematics teacher to explore deeply about their students’ skill of analyzing, skill of evaluating, and skill of creating.
Numerical study on air-core vortex in a dual port cylindrical tank for lower speed of rotations
Authors: Sooraj PV , Joshy PJ 
Published: November 2019

Abstract
Rotating cylindrical tank filled with liquid engendered an air core during draining. The extension of the air-core into the drain port reduces the flow area and consequently the flow rate. The ongoing study focuses on the numerical simulation results of such vortex formation in a rotating cylindrical tank with dual ports in which speed of rotation as the variable parameter here by keeping centre to centre distance fixed.
Simulation of effect of bed temperature over producer gas composition using ASPEN PLUS, its experimental validation and emission characteristics of an IC engine
Authors: Vishnu A R , Kodakkattu Saijal Kizhakke , Fahd Syed Muhammed 
Published: November 2019

Abstract
Biomass is the source of energy that is generated from organic materials, which has the capacity to generate power in different means. Gasification is the technique that converts biomass materials into combustible gas by undergoing chemical reactions at high temperature with a controlled oxygen availability. The objective of this study is to determine the performance of downdraft gasifier and emission characteristics of IC engine using producer gases at various bed temperatures. The satisfactory performance of gasification, is theoretically attaining at a gasification temperature range of 500°c to 750°c. The temperature dependency of gasification process in the performance of downdraft gasifier is studied for different types of feed stocks. The downdraft gasifier is simulated using process simulation software ASPEN PLUS. PLUS. It is found that at higher gasification temperatures the quality of producer gas increases considerably. The exhaust emission characteristics and efficiencies of engine with producer gas are comparable with normal gasoline exhaust characteristics.
Numerical investigations on the heat transfer characteristics of tube in tube helical coil heat exchanger
Authors: Sheeba A , Mathew P , Jose Prakash M 
Published: November 2019

Abstract
Heat transfer characteristics of a tube in tube helical heat exchanger in the laminar flow regime is analysed numerically. Numerical scheme is validated with the experimental results reported in literature. The effect of helix angle on the overall heat transfer coefficient is analysed. The overall heat transfer coefficient increases with Dean number and its rate of increase at higher Dean number is low. The rate of heat transfer is maximum at a helix angle of 27°. Simulation studies show that the secondary flows that originate in a coiled tube due to curvature and torsion produce an additional transport of the fluid over the cross section of the pipe. The overall heat transfer coefficient increases with increase in inner diameter.
CFD analysis of the performance of different airfoils in ground effect
Authors: Zaheer Zubin , Roy K E Reby , Nair Gopakumar S , Ragipathi Vineeth , Niranjan U V 
Published: November 2019

Abstract
Ground effect is a phenomenon caused by the presence of a fixed boundary layer below the wing when it moves close to a fixed surface. This results in an effective increase in lift to drag ratio of the airfoil. In this paper, the performance of three airfoils used in general aviation is analysed in ground effect using ANSYS FLUENT at different operating conditions namely, the angle of attack and the height above the fixed surface. The main objectives are to are evaluate the performance of these airfoils in ground effect at different ground clearances and angles of attack and find the most suitable airfoil which can be used to exploit the advantages of ground effect. It was found that all the airfoils experienced an increase in lift and decrease in drag as distance from the ground reduced thus validating ground effect. The aerodynamic efficiency increases, reaches a maximum, and then decreased as the angle of attack increased due to the onset of flow separation at the top surface of the airfoil. It was also noted that the symmetric airfoil experienced negative lift at very low ground clearances which was attributed to the formation of a venturi effect between the airfoil and ground
Memory Effect in Methane Hydrate Formation
Authors: Pallipurath Mohamed Iqbal , Nagarajan Nandakishore , Vahid Yahiya 
Published: November 2019

Abstract
Memory effect of formation water in methane hydrate formation and reformation is investigated in a high pressure reactor. Methane hydrate formation rates in fresh water and reacted water are measured at different pressures and temperatures. A significant reduction in formation time and incubation period is found with reused water. In the context of transportation of natural gas from distant gas fields as hydrate, this information can be utilized to reduce reduce the transportation cost of natural gas.
Experimental and Numerical Investigations of Synthetic Jet Used for Electronic Cooling
Authors: Jacob Arun , Anandhu R , Leena R , Shafi K A 
Published: November 2019

Abstract
Cooling of electronics and micro-electronics devices is an important task in our present world. Synthetic jet is a relatively new technique for electronic chip cooling which synthesizes stagnant air to form a jet resulted from periodic oscillations of a diaphragm in a cavity. Synthetic jet cooling increases the rate of heat transfer as compared to other cooling techniques. The impingement heat transfer characteristics of a synthetic jet is studying in this work. Synthetic jet is driven by a piston-cylinder arrangement a through circular nozzle for the impingement of jet on the heated surface. Air is considered as the cooling medium. Heat flux is taken as 8000W/m2. Numerical simulations and experimental methods are conducted to study the effect of various distance between the orifice and the heated plated(Z). A circular orifice is used to study the characteristics of convective heat transfer. The results are verified by the time history of convective heat transfer characteristic and validated with experimental results. The model was simulated to investigate the dispersion of heat flow on the walls using a mathematical turbulent model of k- ω SST. The Reynolds number (Re) is in the range of 4000-8000 based on average velocity, while the normalized impinging distance varies between 2D to 10 D The results shows the significant influence of Z/D ratio and sinusoidal wave frequencies to the heat transfer rate obtained. Experimental and numerical investigations is carried out to study the variation of Nusselt number with jet velocity. It is found that the Z/D ratio at 6 gives the maximum amount of cooling for a flat plate.
Simulation of Stratified Two-phase Flow Regime using Air-Water Model in ANSYS Fluent®
Authors: Monachan Binet , Thomas Rijo J. , Steaphen Deepak , Skaria Mathew , Shafi K.A. 
Published: November 2019

Abstract
Two-phase flow has widely grown in importance in various fields of science and engineering system such as nuclear reactors, heat exchangers, transport system, chemical processing plants etc. One of the major issues faced by these sectors is the development of an accurate and reliable multiphase flow measurement system. At present there is no single system which could measure the two phase flow parameters irrespective of its incoming conditions. Characterization of the single phase flow parameter is easier when compared with two phase flow as the velocity distribution, mass flow rate and void fraction of each component phases are not easily measurable. The other factors that add to these difficulties are the prediction of flow regimes and the effect of pipe or channel orientation on the flow properties in the two phase flow. The hold-up of the individual phases and their relative velocity along with pressure drop needs to be taken care while dealing with these flows. Various researches have clearly shown that no correlation can be used for predicting the flow regimes in a two phase flow satisfactorily. By using volume of fluid multiphase flow model air water two phase flow was simulated for inlet velocities of water and air as 0.121 m/s and 6.56 m/s respectively. Stratified laminar flow was obtained from the CFD simulation. Variation in volume fraction of both air and water, mass flow rate and pressure drop with respect to change in time are investigated using the simulation.
A study of factors affecting supply chain performance
Authors: George Joby , Pillai V. Madhusudanan 
Published: November 2019

Abstract
In the present global market, the competition is not between the companies but between the supply chains. The comparison of performance measures of supply chains helps to identify a good supply chain. The best performing supply chains may survive over a long period. The performance of a supply chain is affected by various internal and external factors. The objective of this paper is to identify and conduct a detailed study of the major factors affecting the supply chain performance. The factors are identified by reviewing various literature in the supply chain field. In this respect, a total of 54 literature are reviewed. The major factors identified as supply chain structure, inventory control policy, information sharing, customer demand, forecasting method, lead time and review period length. The optimum selection of parameters of these factors improves the supply chain performance.
POGO Stability Analysis of a typical Launch vehicle for studying the effectiveness of POGO corrector in cryo stage
Authors: Raji R , Jancy Rose K , Murali P R , Neetha R 
Published: November 2019

Abstract
POGO is the longitudinal instability of liquid propellant launch vehicles due to the interaction of structural dynamics with the propulsion system. This interaction may give rise to the initiation of vibrations of large magnitudes when the propulsion and structural frequencies are nearer. This can be avoided by the separation of structural and propulsion frequencies by means of a POGO corrector. The present paper describes the propulsion structural interaction studies for the cryo stage of a typical launch vehicle to avoid POGO oscillations. The propulsion systems are represented as discrete elements described by a set of second order equation and the structure is represented by the normal mode parameters. Assembly of propulsion elements along with structural equations will define the structure propulsion system. Stability of system is studied by evaluating the roots of the assembled equation. The analysis showed that there will not be any POGO oscillations during the flight.
Managing Iterations in Product Development Process Using Dependency Structure Matrix
Authors: Shajahan C A , Firoz N , Sadhikh Mohammed , Pramod N V R , Ashim  
Published: November 2019

Abstract
The market is highly challenging with customers demanding a variety of products at competitive prices. To make a product competitive, it needs to be introduced quickly without compromising on its performance or quality. Thus, reduction of product development cycle time has become essential for companies to thrive and sustain in the market. Product Development (PD) is the set of activities beginning with the perception of a market opportunity and ending in the production, sale and delivery of a product. Companies are forced to develop a well-coordinated development plan to organize their processes and resources to develop competitive products. Today PD confronts complex development challenges. The difficulties in developing complex engineering products do not only arise from their technical complexity but also from the managerial complexity necessary to coordinate the interactions between the different engineering disciplines, which impose additional challenges on the development process. Traditional Project Management techniques are limited in application. Researchers and design managers are constantly searching for the effective and efficient methods for managing PD process. To address the limitations of traditional project management tools, Design Structure Matrix (DSM) has been identified as a sensible tool to represent PD process. In this work, the capability of DSM is demonstrated with a real life case example .The necessity of reducing iterations in PD process using PSM 32 software is also demonstrated
Effect of Strut thickness on the Inflation Behaviour of Coronary Artery Stent using FEM
Authors: Hashim V. , Resmi S.L. , Dr. Dileep P.N. 
Published: November 2019

Abstract
Stent implantation is one of the most accepted method in treating coronary artery diseases due to their simplicity and faster patient recovery. Coronary stents are highly patient specific and the implantation success greatly relies on the design and clinical procedure. Studies confirm that, performance characteristics like radial strength, maximum expansion, stress concentration, recoil etc. are highly governed by the physical design of the stent. This paper focuses on finite element analysis using ABAQUS package to investigate the effect of varying strut thickness on the expansion behavior of a commercially available coronary stent. Envision Scientific Coronary Stent was adopted for this study. Total of five stent designs, one with actual size, two models with a strut thickness lesser than actual thickness and two with higher values were considered. The expansion behavior of the models under consideration was compared to the model with original dimensions. It may be noted that the thickness is one of important design parameter that affects the expansion and stress directly. With 15% reduction in thickness, the expansion increases by 10%. While, for an increase of 15% in thickness resulted in decrease in expansion by 10%. It may be noted that the percentage of increment in stress is linear and inversely proportional. Whereas, the increment in expansion is non linear and is minimal for low thickness. The present approach can be used for selecting the design parameters of stent to arrive in an optimum design.
Design Process Sequencing in Product Development Process Using Design Structure Matrix and Particle Swarm Optimisation Techniques
Authors: Shajahan C A , Subramanyan Embranthiri E , Kumanan S , Firoz N 
Published: November 2019

Abstract
Product development (PD) is a complex business process of transforming new ideas into marketable new products, processes or services. PD process is characterized by information flow and iteration. Traditional project management techniques are limited in representing interdependent activities. Design Structure Matrix (DSM) is a powerful tool for identifying and managing information exchange and iterations. In this work the process is modeled with DSM and the design activities are optimally sequenced using a Particle Swarm Optimization (PSO) technique. The methodology is exemplified with a case example
Experimental study on the influence of hydrophilicity on bacterial adhesion in bioimplants
Authors: Shiju V P , Abhijith N V , Sudeep U 
Published: November 2019

Abstract
Titanium and its alloys are widely used as dental and orthopaedic implants because of their desirable mechanical properties and biocompatibility. However, implant failures due to bacterial infections occur in many cases unexpectedly. Formation of a biofilm on the implant surfaces facilitates growth of colony of bacteria which in turn reduces the effectiveness of antibacterial drugs. Hydrophilicity of implant surfaces diminishes the chances of biofilm formation. Micro surface features are created on the Ti6Al4V implant surface using a pulsed Nd-YAG laser and its influence on water wettability (and thus on hydrophilicity) has been studied and compared with a polished surface. Strains of Staphylococcus aureus have been inoculated on the test specimens and the bacterial adherence have been compared. The results show that micro-textured surfaces of Ti6Al4V have improved water wettability and thus are more hydrophilic than polished surface. This has reduced the formation of biofilm and bacterial growth.
Effect of heat treatment on mechanical and tribological characteristics of Electroless Ni-P deposits
Authors: Arora Abhishek , Kiran K Uday Venkat , Ramakrishnan Bijoy , Sunil B. Ratna , Dumpala Ravikumar 
Published: November 2019

Abstract
In the present paper, mechanical and tribological characteristics of as-deposited and heat-treated Electroless Ni-P coatings were investigated. Medium phosphorus Ni-P coatings were deposited on mild steel substrate using an acidic bath and subjected to heat treatment at 400°C in a tubular furnace. Surface morphology and elemental analysis of the coatings were carried out using Scanning electron microscope (SEM) and Energy dispersive X-ray spectroscopy (EDS) analysis respectively. Dry sliding wear characteristics of the coatings were investigated by linear reciprocating ball on flat tribometer using AISI E52100 Steel ball as a counter body at room (25±2°C) and elevated temperature (300°C). Hardness results showed significant improvement in the surface hardness of coatings on heat treatment. Low friction coefficient and high wear rate were observed at elevated temperature in comparison of those of tests conducted at room temperature for both as-deposited and heat-treated coatings. Best tribological performance is observed for heat-treated coating tested at room temperature.
Investigation of Magnetostriction in Second Generation High Temperature Superconductors
Authors: Ashok K.B. , Thomas R. J. , Prakash M. Jose 
Published: November 2019

Abstract
Superconductors help to drastically improve the efficiency in every field by making the transmission losses of electrical energy to minimum. Superconductors show special properties only when their parameters like temperature, magnetic field, current density, mechanical strain are within their critical limits. Effect of magnetic field on second generation high temperature superconducting compounds have been studied in past few years. In this paper, the numerical simulation of the magnetostriction effect of second generation superconductor REBCO is discussed. The results obtained from numerical studies is compared with the experimental results reported in literature. The findings show that there is good agreement and all the three samples are showing rapid change in magnetostriction when the magnetic field is above 106 A/m.
Homogenization of Mechanical Properties of Unidirectional Fibre Reinforced Composites with Matrix and Interface Defects: A Finite Element Approach
Authors: Siddharth S , Ramesh Ajith 
Published: November 2019

Abstract
Fiber Reinforced Composites find increasing applications in the areas of Aerospace, Military Armours, Bullet-proof vests, etc. As the composites are composed of two different constituents, there arises a need to determine the effective properties of the homogenous composites. Experimental determination of the effective properties is very expensive considering the amount of experiments that are required to be conducted, the time and cost to be incurred for each experiment, and the permutations and combinations of the optimal fiber volume fraction. The effective properties are essential for modeling of composites with reference to real-time applications. The micro-mechanics approach reduces most of the above mentioned complexities and helps in accurately evaluating the effective properties. In the presented paper, the properties like Young’s Modulus, Poisson Ratio, and Shear modulus of a healthy (defect free) composite is obtained by modeling a Representative Volume Element (RVE) using the commercial Finite Element Analysis (FEA) solver – Abaqus, with application of Periodic Boundary Conditions (PBC). The presented research focuses on Fiber-Reinforced Metal-Matrix composites like AA2024-Al2O3 and the Ceramic-Matrix composites like ZrB2-SiC. In general, defects in composites arise during the manufacturing process. Matrix Crack, Interfacial De-bonding and Fiber Crack are the major defects which degrade the mechanical properties of composites. This paper presents the modeling of Interfacial de-bonding using the Cohesive-Zone Modelling (CZM) technique for every 90° variation in the fiber-matrix interface and the subsequent evaluation of the corresponding homogenous properties. Matrix Crack is modelled as a matrix defect with a ‘V’ notch for varying a/w ratios. For every variation in matrix crack, the corresponding properties are estimated. Numerical evaluation of the individual effects of interfacial de-bonding and fully grown matrix cracks are followed by the modelling of the coupled effects.
High-end sensors: challenges for the future
Authors: Yurish Sergey Y. 
Published: November 2019

Abstract
The paper describes the coming challenges in high-end sensors and transducers design. These challenges are coming from the recent technological limitations in microelectronics. The proposed approach to overcome such limitations is based on programmable parameter-to-frequency converters as a digital sensor’s core and advanced method of measurement in order to move from a traditional analog-to-digital conversion to alternative frequency (period, duty-cycle, time interval)-to-digital conversion. Working in the frequency-time signal domain simplifies design, and obviates some technical and technological problems, due to the properties of frequency as informative parameter of sensors and transducers. The major benefits offered by such approach are high reliability, high metrological performance, wide functionality, cost effectiveness and scalability. The perspectives, which will bring such approach to various sensors and transducers for physical and chemical, electrical and non-electrical quantities are illustrated by examples of multivariable sensors, sensors for smart health care and wearable sensors.
Novel multidimensional biomarkers for non-invasive medical diagnostics
Authors: Vonsky M S , Runov A L , Moiseeva O M 
Published: November 2019

Abstract
Value of clinical laboratory diagnostics results are often underestimated in medical practice due to the fact that result of laboratory analysis in most cases represents a single biomarker of the organism homeostasis complex pathological alteration. New systemic approaches emerging on the basis of Omic’s knowledge and techniques allow development of multidimensional biomarkers, reflecting multiple pathobiological axes which characterize defined pathological condition. Combination of liquid biopsy technology with multidimensional biomarkers allows to obtain clinically valuable personalized information on the patient by non-invasive approach even for hard-to-reach organs and tissues.