bluuebunny/crossref_metadata_2025 huggingface dataset:
Bio–Based Lubricants for Numerical Solution of Elastohydrodynamic Lubrication
Authors: Putra Cupu Dedi Rosa , Md Sheriff Jamaluddin , Osman Kahar
Published: October 2019

This paper presents a numerical solution of elastohydrodynamic lubrication (EHL) problem in line contacts which is modeled through an infinite cylinder on a plane to represent the application of cylindrical roller bearing. In this work, the contact between roller element and raceway of outer ring of the cylindrical roller bearing is simulated using vegetable oils as bio-based lubricants. Temperature is assumed to be constant at 40oC. The results show that the EHL pressure for all vegetable oils was increasing from inlet flow until the center, then decrease a bit and rise to the peak pressure. The shapes of EHL film thickness for all tested vegetable oils are almost flat at contact region.
Partially Textured Slider and Journal Bearing Analysis
Authors: Rao T. V. V. L. N. , Rani A. M. A. , Nagarajan T. , Hashim F. M.
Published: October 2019

The present study examines the influence of partial texturing of bearing surfaces on improvement in load capacity and reduction in friction coefficient for slider and journal bearing. The geometry of partially textured slider and journal bearing considered in this work composed of a number of successive regions of groove and land configurations. The nondimensional pressure expressions for the partially textured slider and journal bearing are derived taking into consideration of texture geometry and extent of partial texture. Partial texturing has a potential to generate load carrying capacity and reduce coefficient of friction, even for nominally parallel bearing surfaces.
EFFECTS OF PERCEPTIONS ON BIM ADOPTION IN MALAYSIAN CONSTRUCTION INDUSTRY
Authors: Enegbuma Wallace Imoudu , Aliagha Godwin Uche , Ali Kherun Nita
Published: October 2019

Building information modelling (BIM) continually presents transformation opportunities and strengthening collaboration within the construction industry. People, process and technology are largely discussed factors affecting BIM adoption across the global construction industry. The unsettling precedence envisaged by construction professionals with the onset of BIM in Malaysia has garnered more research focus on this soft issues to technology adoption. Therefore, this paper focuses on the relationship between people, process and technology perception of construction professionals. The overall causal relationship is examined towards effects on BIM adoption in addition to the degree of influence. Quantitative data was derived through a survey of 352 construction professionals (Architects, Quantity Surveyors, Engineers and Contractors) which was further anlysed using SPSS and Amos v20. The results revealed a high correlation between people, process and technology (>0.50) while process significantly affected BIM adoption (0.35). Overall, the model explored validated the conceptual framework on the impact of BIM perception of construction industry professionals in Malaysia on the adoption rate of BIM. The results denote grey areas for construction industry stakeholders to direct more efforts towards improving knowledge on BIM technology.
PERCEIVED RESTORATIVE BENEFITS OF OBUDU MOUNTAIN LANDSCAPE, NIGERIA
Authors: Ojobo Henry , Said Ismail , Mohamad Sapura , Abdullah Aldrin , Ujang Norsidah
Published: October 2019

Specific natural environments evoke restorative potentials for the amelioration of stress necessary for human wellbeing. However, studies focusing on the evaluation of this phenomenon have covered mainly forests, wilderness and urban landscape features, while mountain landscape features have not been adequately explored. This study examined the perception of individuals regarding the benefits of contact with the features of a mountain landscape environment in relation to human wellbeing. A direct rating scale questionnaire was administered to 200 respondents drawn from a population of lecturers and students. Overall findings suggest that the multi-stimulus Obudu mountain landscape environment possesses the potential to enhance wellbeing through excitement, calmness and stress relief. This finding will inform policy makers and landscape architects in decision-making concerning the development of mountain landscape environments and provision of landscape features for specific environments.
COMPARISON OF AN X4-AUV PERFORMANCE USING A BACKSTEPPING AND INTEGRAL BACKSTEPPING APPROACH
Authors: Harun Nur Fadzillah , Md. Zain Zainah
Published: October 2019

X4-AUV is a type of an autonomous underwater vehicle (AUV) which has 4 inputs with six degrees of freedoms (6-DOFs) in motion and is classified under an underactuated system. Controlling an underactuated system is difficult tasks because of the highly nonlinear dynamic, uncertainties in hydrodynamics behaviour and mostly those systems fails to satisfy Brockett’s Theorem. It usually required nonlinear control technique and this paper proposed an integral backstepping controller for stabilizing an underactuated X4-AUV. A control law is designed for the system in new state space using integral backstepping. The performance of the proposed control method is examined through simulation and results demonstrate all motion is stabilized and convergence into desired point. We also compared the results with backstepping approach to see the effectiveness of the propose control system.
STRUCTURAL CHARACTERIZATION OF SULFOBORATE GLASSES CONTAINING MAGNESIUM OXIDE
Authors: Dalhatu S. A. , Hussin R. , Deraman Karim
Published: October 2019

Magnesium sulfoborate glasses of different compositions were prepared using melt quenching method with the purpose of using it for optical properties. The Fourier Transform Infra-red (FTIR) Spectroscopy, Nuclear Magnetic Resonance (NMR) and X-Ray Diffraction (XRD) have been carried out. Density and molar volume have been evaluated and analysed. From the results of XRD, the absent of discrete and continuous sharp peaks confirmed the amorphous nature of the glass compositions while the results from both FTIR and NMR revealed the existence of BO3, BO4 units. Addition of MgO to sulfoborate influenced the conversion of the dominant BO3 groups to BO4 groups. The BO4 groups are known for creating complex defects that transform into that stable trap good for optical phenomena. It was observed that the density of glass increases while the molar volume is decreases with respect to increase in concentration of alkaline earth oxide in the glass compositions.
RESPONSE OF FBG–BONDED PLASTIC PLATE AT DIFFERENT LOCATIONS OF APPLIED STRESS
Authors: Mohammed Salih Younis , Munajat Yusof , Ismail Abd Khamim , Bakhtiar Hazri
Published: October 2019

Fiber Bragg Grating sensing (FBG) has been intensively studied in the application of smart structures because of its immense advantages offered over those of the conventional sensors. In these researches unique characteristics of FBG, like its high sensitive resonance frequency spectrum and its resonant behavior were reported when FBG was coated by a ring-shaped material and used as an underwater acoustic sensor. In this study, the response of a FBG-bonded plastic plate at different locations of applied stress is demonstrated. The sensing element utilized for this purpose is a 10 mm FBG sensor bonded onto the surface of a plastic plate. Results of reflection spectrum showed that the output power increased randomly when the location of applied stress approached the location of FBG. This was assured from the increment of the area of reflection spectrum. The random increase in the output voltage was attributed to the insufficient stiffness of the plastic ruler, suggesting the implement of graphene plate instead of plastic ruler and increasing the grating length of FBG. The results showed an increase in the output power as detected by the photodiode. Consequently, a clear correlation between the optical and electrical outputs was observed.
FIRING BEHAVIOUR OF CERAMIC WHITEWARE BODIES INCORPORATED WITH LOCAL FELDSPATHIC SOURCES
Authors: Othman Radzali , Mohamad Mahizar
Published: October 2019

Quarry dust is a by-product of granite quarrying activities. Granite fragments, that are normally obtained from blasting granite rocks in a particular quarry, are subjected to a number of machineries of decreasing crushing aperture sizes and each attendant sieving to obtain granite aggregates of the desired size, normally 20 mm, 10 mm, etc.  These are to be used in the construction of buildings as coarse aggregates in concrete mixes, as well as in the laying of tarred roads. The finest fraction, nominally below 7 mm or 5 mm in size depending on the practice of the quarrying company, is normally dumped on site. It is considered to be a waste that needs to be disposed of. Apart from attending to the environmental issue, the reuse of such waste material in the development of new products would be an attractive commercial proposition. In this work, granite quarry dust was incorporated into a clay-based ceramic body to replace the use of feldspar (an expensive component) as the fluxing agent in such triaxial clay whiteware compositions. A fluxing agent is the component in a ceramic body composition that melts first and functions as the component that binds together all the other solid particles into a rigid body. Initially, the quarry dust was chemically and mineralogically characterized before mixing with clay at a fixed 45:55 weight ratio. The mixtures were then pressed and fired at various temperatures before testing the properties of the fired products. A comparison was made with a local feldspathic source from Gua Musang to ascertain the feasibility of such replacement to produce high quality ceramic bodies. It was found that mineralogically the granite quarry dust consists of K-feldspar (or orthoclase) as compared to Na-feldspar (or albite) found in the Gua Musang feldspar. This led to melting at a lower temperature of the former but exhibited a much more viscous melt. At the same time, the higher iron content in the granite quarry dust led to a much darker colourisation of the body upon firing. In conclusion, the granite quarry dust has been found to be successful in lowering the maturing temperature of ceramic bodies compared to the Gua Musang feldspar beside conferring stability of the low porosity property over a wider firing temperature.
A NOVEL MICROWAVE SENSOR WITH HIGH-Q SYMMETRICAL SPLIT RING RESONATOR FOR MATERIAL PROPERTIES MEASUREMENT
Authors: A. Alahnomi Rammah , Zakaria Z. , Ruslan E. , Mohd Bahar Amyrul Azuan , Shairi Noor Azwan
Published: October 2019

A new sensor based on symmetrical split ring resonator (SSRR) functioning at microwave frequencies has been proposed in order to detect and characterize the properties of the materials. This sensor is based on perturbation theory, in which the dielectric properties of the material affect the quality factor and resonance frequency of the microwave resonator. Conventionally, coaxial cavity, waveguide, dielectric resonator techniques have been used for characterizing materials. However, these techniques are often large, and expensive to build, which restricts their use in many important applications. Thus, the proposed bio-sensing technique presents advantages such as high measurement sensitivity (around 400 Q-factor) with the capability of suppressing undesired harmonic spurious and permits potentially material characterization and determination.  Hence, using a specific experimental methodology, tests performed have demonstrated the biosensor ability to characterize at least four references materials with known permittivity (Air, Roger Duriod RT 5880, Roger Duriod RT 4530, FR4) and one material with unknown permittivity (Beef). Accordingly, the numerically established relations are experimentally verified for these reference materials and the results indicated that the average estimation error of measuring the permittivity was 2.56 % at resonant of around 2.2 GHz.  The proposed design is useful for various applications such as food industry, medicine, pharmacy, bio-sensing and quality control
La reforma a la ley inglesa de seguros – The Insurance Act 2015- comentarios preliminares con especial referencia a las modificaciones en materia de garantías (Warranties)
Authors: Signorino Barbat Andrea
Published: October 2019

El presente artículo busca acercar al lector comentarios preliminares sobre ciertos aspectos destacados de la nueva o última Ley inglesa de seguros, la Insurance Act 2015, en vigencia desde agosto de 2016, en especial las modificaciones que la misma imprime al régimen de garantías, o warranties. La icónica Ley marítima inglesa de 1906 ha quedado en consecuencia reformada y estas novedades no pueden pasar desapercibidas. Esto ya que las leyes inglesas de seguros, aplicables en su medida a los seguros marítimos, son siempre un referente no solo de derecho comparado, sino por influir en sistemas tan aparentemente distantes como los de Argentina y Uruguay, dada la fidelidad de los mercados mundiales de seguros marítimos a la legislación inglesa en la materia.
Piezoelectric Actuated Nonlinear Energy Sink With Tunable Attenuation Efficiency
Authors: Zhao Jian , Lyu Ming , Wang Hongxi , Kacem Najib , Huang Yu , Liu Pengbo
Published: October 2019

Comparing to linear vibration absorbers, nonlinear energy sinks (NESs) have attracted worldwide attention for their intrinsic characteristics of targeted energy transfer or energy pumping in a relatively wide frequency range. Unfortunately, they are highly dependent on the vibration amplitude to be attenuated and will play its role only if the external load exceeds a specific threshold value. Different from the passive bistable NES, a novel piezoelectric nonlinear energy sink (PNES) is designed by introducing in-phase actuation to compensate or enhance the external vibration loads, thus triggering the NES operating in high attenuation efficiency. The nonlinear mathematic model of the PNES is established for investigating the dynamic response and determining the threshold compensation strategy. And the results show that the maximum attenuation efficiency can be improved by 58.16% compared to the traditional passive NES. Also, the amplitude-dependent coefficient (ADC) can be significantly reduced to 0.33 from 1.0, which means that the PNES can effectively mitigate vibrations even when the excitation amplitude is 67% smaller than the original threshold value. Finally, the feasibility of the in-phase compensation method is experimentally validated, which can further expand the application range of NES.
Two- and Three-Dimensional Failure Criteria for Laminate Composites
Authors: Mega Mor , Dolev Orly , Banks-Sills Leslie
Published: October 2019

Several two- and three-dimensional mixed-mode interface failure criteria are proposed for predicting delamination failure in multidirectional, laminate composites. The proposed criteria, based on the stress intensity factors K1, K2, and KIII, as well as the critical interface energy release rate Gic and phase angles ψ and ϕ, are examined using results obtained from Brazilian disk mixed-mode fracture toughness tests. Two material systems are considered. The first contains a delamination along an interface between a unidirectional fabric and a plain woven fabric. The second is composed of a plain woven fabric with fibers oriented in different directions in succeeding plies. The former was manufactured by means of a wet-layup and the latter is a prepreg. Finally, a statistical analysis is carried out to obtain a failure curve or surface with a 10% probability of unexpected failure and a 95% confidence. These curves or surfaces may be used to predict failure of structures containing these laminates and to assist in composite design.
Development of a Global Design Education Experience in Bioengineering Through International Partnerships
Authors: McCullough Melissa , Msafiri Nicodemus , Richardson William J. , Harman Melinda K. , DesJardins John D. , Dean Delphine
Published: October 2019

The field of engineering is increasingly appreciating the value of diversity for innovative design solutions. Successful engineering depends on our ability to explore constrained parameter spaces for finding the best solutions, and more diverse minds and experiences enable us to explore the entire potential solution space more thoroughly, more quickly, and more creatively. With a goal to expand the diversity of experiences and mindsets in our undergraduate bioengineering curricula, Arusha Technical College (ATC) in Arusha, Tanzania and Clemson University (CU) in Clemson, South Carolina, U.S., have partnered together over the past 5 years to provide intercontinental educational opportunities for undergraduate students, graduate assistants, and faculty. In 2018, CU and ATC collaborated on an international design course targeting undergraduate students in biomedical engineering focused on global health solutions for resource poor communities. Undergraduate students from ATC and CU collaborated on design projects through formal videoconferenced group meetings, e-mail, and various social media platforms. The year ended with a joint design symposium in Arusha where the students presented on their work in a public poster forum. This successful ATC-CU Global Health Design Collaboration pilot year provides a solid model upon which to build. Students reported overall positive experiences and plans to continue in their curriculum to graduation, as well as some ATC and CU students changing their career direction to include global health initiatives.
Selective Thermal Stimulation Delays the Progression of Vasoconstriction During Body Cooling
Authors: Namisnak Laura H. , Khoshnevis Sepideh , Diller Kenneth R.
Published: October 2019

The objective of this study was to test the feasibility of selective thermal stimulation (STS) as a method to upregulate glabrous skin blood flow. STS is accomplished by mild surface heating along the spinal cord. Four healthy subjects were tested in this study. Each participated in a control experiment and an intervention experiment (STS). Both experiments included establishing a maximum level of vasodilation, considered unique to a subject on a test day, and then cooling to a maximum level of vasoconstriction. Perfusion was measured by a laser Doppler flow probe on the index fingertip. The percent of perfusion in the range of minimum to maximum was the primary outcome variable. The data were fit to a linear mixed effects model to determine if STS had a significant influence on perfusion during whole body cooling. STS had a statistically significant effect on perfusion and increased glabrous skin blood flow by 16.3% (P < 0.001, CI (13.1%, 19.5%)) as skin temperature was decreased. This study supports the theory that STS improves the heat exchanger efficiency of palmar and plantar surfaces by increasing the blood flow.
A Two-Dimensional Model of Hypertension-Induced Arterial Remodeling With Account for Stress Interaction Between Elastin and Collagen
Authors: Rachev Alexander , Shazly Tarek
Published: October 2019

We propose a novel structure-based two-dimensional (2D) mathematical model of hypertension-induced arterial remodeling. The model is built in the framework of the constrained mixture theory and global growth approach, utilizing a recently proposed structure-based constitutive model of arterial tissue that accounts for the individual natural configurations of and stress interaction between elastin and collagen. The basic novel predictive result is that provided remodeling causes a change in the elastin/collagen mass fraction ratio, it leads to a structural reorganization of collagen that manifests as an altered fiber undulation and a change in direction of the helically oriented fibers in the tissue natural state. Results obtained from the illustrative simulations for a porcine renal artery show that when remodeling is complete the collagen reorganization might have significant effects on the initial arterial geometry and mechanical properties of the arterial tissue. The proposed model has potential to describe and advance mechanistic understanding of adaptive arterial remodeling, promote the continual refinement of mathematical models of arterial remodeling, and provide motivation for new avenues of experimental investigation.
Heat Transfer Characteristics and Kinetics of Camellia oleifera Seeds During Hot-Air Drying
Authors: Huang Dan , Tao Yuchao , Li Wei , Sherif S. A. , Tang Xiaohong
Published: October 2019

The heat transfer characteristics and kinetics of Camellia oleifera seeds under hot-air drying were investigated at different temperatures (40, 60, and 80 °C) and loading densities (0.92, 1.22, and 1.52 g/cm2) with a constant air velocity of 1 m/s. Twelve common drying kinetic models were selected to fit the experimental data. The most suitable model was chosen to describe the hot-air drying process of C. oleifera seeds and help in its optimization. The results showed that the drying temperature has a significant influence on the hot-air drying characteristics of C. oleifera seeds. As the drying air temperature increases, the drying time decreases. The effect of the loading density on the drying characteristics of C. oleifera seeds is much smaller than that of temperature. With the increase in the loading density, the drying time slightly increases. The hot-air drying curve of C. oleifera seeds consists of a very short acceleration rate period at the beginning and a long falling rate period, indicating that the drying of C. oleifera seeds is mainly controlled by the diffusion of moisture inside the material. An effective moisture diffusion coefficient of C. oleifera seeds was estimated to range from 0.81256 × 10−9 to 3.28496 × 10−9 m2/s within the temperature range studied. The average activation energy was 28.27979 kJ/mol. The logarithmic model was found to be the best model to describe the kinetics of hot-air drying of C. oleifera seeds.
Thermo-Convective Flow of a Yield-Stress Fluid Between Two Horizontal Plates for Rayleigh Numbers Greater Than the Critical Value
Authors: Mkacher Hakim , Ayadi Abdelhak
Published: October 2019

In this paper, two-dimensional unsteady simulations of yield-stress fluids in the Poiseuille–Rayleigh–Bénard flow between two horizontal plates were performed. The laminar flow of these fluids is characterized by the existence of high- and low-viscous zones. The thermal and hydrodynamic behaviors were studied in the case where the convective instability was developed, and the high-viscous zones were minimized. The commercial computational fluid dynamics (CFD) package fluent was adopted to perform the different simulations. The average Nusselt number over time of the two plates was chosen to characterize the thermal transport, while the average of the maximum vertical velocity component over time in the horizontal mid-plane described the hydrodynamics of the flow. It was found that the fluid behaved according to a range of viscosities with the same order of magnitude as the plastic viscosity. The effect of the dimensionless numbers on the flow showed that the yield-stress fluid could mimic a Newtonian behavior in the pre-described conditions. Although, the fluid still held the non-Newtonian character distinguished by the dependency on the Bingham number Bn. This returned to the increase of the apparent viscosity with Bn which contributed to the weakening of the convective streams, and consequently, reduced convective thermal transport.
Exploring Synergy Among New Generation Technologies—Small Modular Reactor, Energy Storage, and Distributed Generation: A Strong Case for Remote Communities
Authors: Joshi K. A. , Poudel B. , Gokaraju R.
Published: October 2019

With a steady rise in power demand in the remote communities in Canada, utilities are looking for new options to provide a reliable supply of electricity. While distributed generation is a promising option, scaling and firming up the capacity of distributed generators is essential. Alternatively, small modular reactors (SMRs) can be used as a prime local source of electricity for remote feeders provided they are flexible enough to respond to the fluctuations in demand. Electrical energy storage (EES) can be used as a buffer to absorb fluctuations in demand and generation, and as a critical back-up for the SMR on-site power supply system by replacing the diesel-generator sets. The synergy of SMR-EES-distributed generation can be an all-inclusive alternative with win-win situation for both the utility and remote communities. This paper discusses the technical feasibility of the proposed synergy using an example of an existing remote feeder in Saskatchewan, Canada. The integral pressurized water reactor is considered along with the photovoltaic (PV) generation in an existing remote feeder in Northwest Saskatchewan to estimate the plant load factor (LF) of the SMR with and without the PV generation and EES. The results quantify the benefit of having EES to support the SMR in hosting more PV generation in remote communities. EES when used in support of the SMR to host 60% PV penetration, the plant load factor improves by as much as 5%.
High Spatial Resolution Crack Monitoring in Concrete Structures Using a Distributed Fiber Optic Sensor
Authors: Li Kevin (Wenhai) , Gaudet Michel
Published: October 2019

A method to monitor the mechanical behavior and identify crack location and growth in a concrete structure element using a distributed fiber optic sensor (FOS) system is demonstrated experimentally by testing concrete specimens in four-point bending. The sensor system consisted of an optical frequency domain reflectometry (OFDR) interrogator unit paired with an all-grating sensing fiber that was bonded to the surface of the concrete test specimen. Strain measurements with high spatial resolution of <10 mm were obtained at various points along a single fiber cable. Large strain values at the crack locations indicated strain concentrations that could be used to assess the crack growth. The distributed sensing system demonstrated the capability to detect localized, early stage cracks, with crack width smaller than 0.1 mm, well before they become observable by visual inspection.
Experimental Investigation on Flash Evaporation Related to Pipe Leakage
Authors: Cai Benan , Zhang Qi , Weng Yu , Gu Hongfang , Wang Haijun
Published: October 2019

Pipelines such as the surge line and main pipe are easily subjected to thermal stratification and thermal fatigue as a result of the nonuniform temperature distribution in the nuclear power plants. When the surge line or main pipe subjected to thermal stratification and thermal fatigue keeps operating for long time, the pipe leakage may happen due to the existence of pipeline crack. When the fluids with high temperature and pressure leak in the crack, the water will evaporate quickly, which means this process belongs to spray flash evaporation process. The flash evaporation related to pipe leak was experimentally studied in the paper. The experiment was carried out under high temperature and high pressure with low spray rate. The temperature and relative humidity (T&H) variations over time were monitored in the experiment with installing T&H detectors. The T&H variations at different measurement positions and with different spray rates were analyzed, respectively. In addition, the effect of the dimensionless parameters including the Weber number and Jakob number was also investigated. Results indicated that the response speed increased with the increase of the spray flow rate. Higher Weber number and higher Jakob number led to higher evaporation rate. The slight pipe leakage can be predicted by using the (T&H) in the hazardous areas.
Complex Solutions for Complex Problems? Exploring the Role of Design Task Choice on Learning, Design for Additive Manufacturing Use, and Creativity
Authors: Prabhu Rohan , Miller Scarlett R. , Simpson Timothy W. , Meisel Nicholas A.
Published: October 2019

The integration of additive manufacturing (AM) processes in many industries has led to the need for AM education and training, particularly on design for AM (DfAM). To meet this growing need, several academic institutions have implemented educational interventions, especially project- and problem-based, for AM education; however, limited research has explored how the choice of the problem statement influences the design outcomes of a task-based AM/DfAM intervention. This research explores this gap in the literature through an experimental study with 175 undergraduate engineering students. Specifically, the study compared the effects of restrictive and dual (restrictive and opportunistic) DfAM education, when introduced through design tasks that differed in the explicit use of design objectives and functional and manufacturing constraints in defining them. The effects of the intervention were measured through (1) changes in participant DfAM self-efficacy, (2) participants' self-reported emphasis on DfAM, and (3) the creativity of participants' design outcomes. The results show that the choice of the design task has a significant effect on the participants' self-efficacy with, and their self-reported emphasis on, certain DfAM concepts. The results also show that the design task containing explicit constraints and objectives results in participants generating ideas with greater uniqueness compared with the design task with fewer explicit constraints and objectives. These findings highlight the importance of the chosen problem statement on the outcomes of a DfAM educational intervention, and future work is also discussed.
Computational Design of a Single Heater Convective Polymerase Chain Reaction for Point-of-Care
Authors: Shu Jung Il , Baysal Oktay , Qian Shizhi , Qiu Xianbo
Published: October 2019

Recently, researchers have started working to develop polymerase chain reaction (PCR) devices as a means for point-of-care (POC) applications. Among the requirements are portability, affordability, and performing reliably and quickly. Proposed by the present study is a process to design a convective-PCR (CPCR) device with only a single heater. It is assumed that such a design developed using microfluidics and capillary tube should help make a CPCR to be portable and more economical for POC use. One of the challenges is to achieve steadily the prerequisite three temperature zones with a single heater. It is demonstrated that this can be done with the present methodology. The underlying physics of the convection driving the CPCR function is mathematically modeled, then verified by our experimental results. In search of better designs, the following parameters that affect the CPCR performance are considered: the heater's height, and the diameter, the height, and the wall thickness of the capillary tube. A large design space consisting of design candidates is defined by combining the values within the range of each of these parameters. The results of the corresponding design cases are obtained from our mathematical model, and the performance of each case is evaluated by their deoxyribonucleic acid (DNA) doubling time. The two best CPCR performing reactors are selected and discussed. It is, therefore, demonstrated that the present methodology is capable of enhancing the CPCR reactor performance with a single heater.
Shell-Side Condensation Characteristics of R410A on Horizontal Enhanced Tubes
Authors: Tang Weiyu , Li Wei
Published: October 2019

An experimental investigation into heat transfer characteristics during condensation on two horizontal enhanced tubes (EHTs) was conducted. All the tested EHTs s have similar geometries with an outer diameter of 12.7 mm, and a plain tube was also tested for comparison. Investigated enhanced surfaces consist of dimples, protrusions, and grooves, which may produce more flow turbulence and enhanced the liquid drainage effect. The effects of mass fluxes and vapor quality were compared and analyzed. Test conditions were as follows: saturation temperature fixed at 45 °C, mass flux varying from 100 to 200 kg m−2 s−1, and vapor quality ranging from 0.3 to 0.8. The heat transfer coefficient was presented, and the results show that the proposed enhanced surfaces seem to have worse performance than the conventional tubes when the mass flux is less than 150 kg m−2 s−1, while one of the enhanced tubes (2EHT-1) produce an enhanced ratio of 1.03–1.14 when G = 200 kg m−2 s−1. Besides, it was found that the heat transfer coefficient increases with increasing vapor quality, which can be attributed to the increasing diffusion resistance. Mass flux seems to have little effect on the heat transfer performance of smooth tubes, while that of 1EHT increases obviously with increasing mass flux, especially for high vapor qualities.
Particle-Based Modeling of Electron–Phonon Interactions
Authors: Sabatti Flavio F. M. , Goodnick Stephen M. , Saraniti Marco
Published: October 2019

An important challenge in particle-based modeling of electron–phonon interactions is the large difference in the statistical weight of the particles in the two simulated populations. Each change in the state of a simulated phonon during scattering is statistically representative of an interaction with multiple simulated electrons, which results in a large numerical burden accurately represent both populations. We developed two stochastic approaches to mitigate this numerical problem. The first approach is based on Poisson modeling of the scattering processes coupled with a thinning algorithm, which works effectively at steady-state, but it is prone to statistical errors in the energy during the transient regime. The second approach is based on point process (PP) modeling of the scattering, allowing stochastical book-keeping, which corrects the energy error. Here, we present a mathematical description of the problem and the two stochastic approaches along with the numerical results we obtained for the synchronous transient simulation of the electron and phonon populations.
Heat Transfer Prediction From Large Eddy Simulation of a Rotating Cavity With Radial Inflow
Authors: Onori Michel , Amirante Dario , Hills Nicholas J. , Chew John W.
Published: October 2019

This paper describes a large eddy simulation (LES) conducted for a nonadiabatic rotating cavity with a radial inflow introduced from the shroud. The dimensionless mass flowrate of the radial inflow is Cw = 3500 and the rotational Reynolds number, based on the cavity outer radius, is equal to Reθ=1.2×106. The time-averaged local Nusselt number on the heated wall is compared with the experimental data available from the literature, and with those derived from the solution of two unsteady Reynolds-averaged Navier–Stokes (URANS) eddy viscosity models, namely, the Spalart–Allmaras and the k−ω shear stress transport (SST) model. It is shown that the Nusselt number is underpredicted in the lower part of the disk and overpredicted in the outer region by both URANS models, whereas the LES provides a much better agreement with the measurements. The behavior results primarily from a different flow structure in the source region, which, in the LES, is found to be considerably more extended and show localized buoyancy phenomena that the URANS models investigated do not capture.
Hydraulic Simulation for Calcasieu Lake Area With Small Rivers Using an Immersed Boundary Method
Authors: Yadav Arun , Zhang Ning
Published: October 2019

A coupled one-dimensional (1D) and two-dimensional (2D) hydrodynamic model for small rivers and streams on a large background area using an immersed boundary method (IBM) was developed and implemented for a simple flooding case in a previously published study. In this study, the IBM model was applied for simulations on a real geographical area, the Calcasieu Lake and its surrounding area in Southwest Louisiana. The simulation area ranges from the city of Lake Charles on the north to Gulf of Mexico on the south, and two National Wildlife Refuges (NWR) on the east and west side of Calcasieu Lake. A small change in the natural state of Calcasieu Lake, i.e., the change in the water surface elevation or flooding, can have a drastic impact on the ecosystem of its surrounding wetlands. The flooding to the wetlands is mainly through small rivers connected to the lake. In order to study the effects of coastal flooding to the wetlands, the IBM 1D–2D coupled model was implemented in the simulation package. The main purposes of this study are to: (1) determine the appropriate number of immersed boundary points to be used for this simulation and (2) test the applicability and validate the IBM model for an actual geographical region. Due to the lack of measurement data for the small rivers, the validation was conducted by comparing simulated results from IBM to the results from a non-IBM approach (i.e., manually carved rivers). Data from NOAA and USGS were used for the boundary conditions for the 2D model.
Pakiwaitara - social work sense for supervision
Authors: Elkington Jacquelyn
Published: October 2019

Pakiwaitara (Elkington, 2001) came about as a gap identified in social service delivery between western, middle class, dominant culture and the healing of Māori whānau in crisis. While education has responded to this gap by offering bicultural training, ensuring more Māori components within degree programmes, etc, social services statistics are still high for Māori and indigenous peoples. It has helped to shift the definition of cultural supervision to inside the definition of specialised professional supervision (Elkington, 2014), but now continued invisibility of values and beliefs, particularly that of Tauiwi, exacerbate the problem. The challenge must still be asserted so that same-culture practitioners are strengthened in same-culture social work practice (eg, by Māori, for Māori), and to avoid when possible, or otherwise by choice, white dominant-culture practice, for all-and-every-culture social work practice (eg, by Pākehā, for everyone).
Mātauranga-ā-whānau – He Kōnae Aronui
Authors: Whakaatere Pohatu Taina
Published: October 2019

Many initiatives stem from simple and humble beginnings. ‘He kōnae aronui’ is therefore drawn from Reweti Kohere’2 book of the same name, published in 1951. In explaining the title of his book, Kohere said, ‘mine is only a kōnae, a rourou, a little bit of wisdom, so that it humbly announces itself as he kōnae aronui’ (Kohere, 1951, p. 10). The same slant guides this article; that of a small piece of writing on mātauranga-ā-whānau. How mātauranga-ā-whānau influences behaviour and the way we engage in kaupapa and relationships is explored. Whānau images, voices, stories and thoughts will be brought forward then talked back to. Processes and patterns will be identified, offering a view of what mātauranga-ā-whānau is and how it has and may guide practice through time. When asking the question, ‘where is the first place that we would go to, to draw experience of mātauranga from?’, this small piece proposes that whānau is an obvious ‘first place’ to turn to. It proposes that for Māori, whānau is an acknowledged rich source of applied knowing and experience to draw from, where there is a willingness to invite it as a highly valued companion (hoa-haere) in kaupapa, no matter what it is, where we are and who we are with. A conscientising internalised lens is what it offers Māori in all of our journeys, collectively or individually.
New wine from old wineskins, a fresh look at Freire
Authors: Walker Shayne
Published: October 2019

Recently, I re-read Freire’s (1972) Pedagogy of the oppressed and found his emphasis on love inspiring. I was left wondering why this is not often quoted regarding Freire. As an educator (University of Otago), regulator (SWRB), whānau worker and supervisor (NGO staff), I believe my work here in Aotearoa New Zealand is about creating contexts within which it is easier to love. I view love broadly as a set of attitudes, actions and thoughts. It produces a professional set of skills that is a personal journey of completion. I am not patient, tolerant or fair all the time, but I should at least try to be. Perhaps love in the context of professional relationships within the social work process is at the heart of a 21st century emancipation and liberation of Māori and other oppressed groups in Aotearoa. Freire understood that treating people as ‘fully human’ in the social work process was in itself an act of love, otherwise it would be dehumanising.In this article I will be discussing:conscientisation, colonisation, dehumanisation, historical trauma and intergenerational trauma;Freire’s (1972) notion of a ‘culture of silence’;identity;transformative relationships;love in social work;Freire’s virtues and qualities for social workers; andfully human practice.
Courageous conversations in supervision
Authors: Davys Allyson
Published: October 2019

INTRODUCTION: Courageous conversations, commonly identified as conversations which are associated with some form of emotion, are features of many social workers’ daily routine. In supervision, such conversations are typically required to address issues of supervisee professional competence, ethical issues or the supervision relationship and/or process. These conversations, which are challenging, are at times avoided and, at other times, may be poorly handled.APPROACH: Following identification of the obstacles which may impede addressing challenging issues in professional practice, this article focuses the supervisor’s role in courageous conversations. The importance of building a supervision environment which can support robust conversations is highlighted. Here the contracting process, where the expectations of supervision are negotiated and the power inherent in the supervision relationship can be identified, is considered foundational. The skills and attributes needed by the supervisor to manage these difficult encounters are explored and three kinds of interventions are identified as helpful: relational, reflective, and confrontational. A framework for a courageous conversation is provided which highlights the need for clarity about the motivation, purpose and desired goals. Finally, a structure for the proposed conversations is presented.IMPLICATIONS: With an understanding of the dynamics and of the skills required, supervisors can better prepare themselves for courageous conversations. When supervision relationships are based on negotiation and shared understanding about power, difference and expectations, hard issues can be raised and honestly confronted and at the same time the integrity of all involved can be maintained.
Implementing the integrated model of supervision: A view from the training room
Authors: Sturt Penny , Rothwell Bridget
Published: October 2019

The integrated model remains fit for purpose as a framework for supervision which is under significant pressure in an environment of austerity and heightened demand. It will only realise its potential if the power of integration is understood and the influence of context is sufficiently recognised. Successful implementation relies fundamentally on two things: the capacity of both supervisor and supervisee to engage in a relationship, and the availability of systemic support for both that relationship and what it is designed to do.This viewpoint explains the model, how we use it as trainers and some of the challenges to effective supervision practice we hear being discussed. Social work in the United Kingdom (UK) seems to be grappling with retaining the social when so much focus is on individualised approaches or, as we see them, fragmentary, partial understanding of context. We have summarised this fragmentation as being symbolised by 4Rs, and it remains our view that these elements need to be, and can be, integrated within the supervisory model. In the UK there has been a resurgence in strengths-based approaches, most recently, restorative practice. Arguably, being restorative has always been part of supervisory intention: we think the model supports this quite explicitly. Much emphasis is currently given to the (sometimes misunderstood concept of) resilience of practitioners and we believe the extrinsic elements of this need reiterating. The ability to reflect on the impact practitioners have on others, particularly those using their services, remains key. Finally, the issue of recording needs re-examination.
A manager’s challenge: Is external supervision more valuable than increased training money for staff?
Authors: Holz Craig
Published: October 2019

INTRODUCTION: Supervision is regarded as an integral necessity for the development and maintenance of professional standards in social workers and is also common practice in other health professions. There is debate, however, about the relative strengths of external and internal supervision. External supervision is recommended but there is a significant financial cost in contracting external supervisors. Also, some argue that internal supervision better manages staff and simplifies communication.METHODS: This article provides a case study of an agency considering changing its supervision systems and the relative benefits and risks that need to be considered.FINDINGS: Each agency needs to consider how to get the best from staff development resources considering the time or finances available. External supervision can offer wider choice to staff with more ethical issues debated. However, this may limit other staff development funding.CONCLUSION: It is recommended that every agency regularly review how to get the best supervision for its staff.
Newly-qualified social workers: A practice guide to the Assessed and Supported Year in Employment (3rd ed.)
Authors: Appleby Joanna
Published: October 2019

Book review
Effect of annealing of NbLaO dielectric on the electrical properties of ZnO thin-film transistor
Authors: Liu Yurong , Xiang Yinxue
Published: October 2019

ZnO thin-film transistors (ZnO TFTs) with high-k NbLaO as a gate dielectric were fabricated on an indium tin oxide (ITO)-coated glass substrate. The NbLaO film was prepared by the sputtering method at room temperature and then annealed in N2 at 200, 300, and 400 °C. The effect of annealing temperature on the quality of NbLaO and ZnO films, especially on the electrical properties and the bias-stress stability of the ZnO TFT, was investigated. The AFM images reveal that the NbLaO film annealed at 300 °C exhibits a relatively smooth surface morphology with a root mean square roughness of 0.31 nm. AFM and x-ray diffraction measurements confirmed that the grain size of ZnO thin films slightly decreases with the increase of the annealing temperature. Except the mobility of slightly less than that of the device annealed 200 °C, the other electrical properties (off-state current, on/off current ratio, and subthreshold slope) of the ZnO TFT annealed at 300 °C are better than those of the samples annealed at 200 and 400 °C and show excellent gate-bias stress stability, which is due to a combination effect of a smoother interface, a denser structure, and the absence of indium doping in the NbLaO gate dielectric, thus resulting in a lower interfacial trap density.
Theoretical and experiment analysis on the sound absorption characteristics of a layer of fine lightweight powder
Authors: Sakamoto Shuichi , Yamaguchi Kohei , Ii Kohei , Takakura Rikuya , Nakamura Yuya , Suzuki Ryusuke
Published: October 2019

In this study, the sound absorption characteristics of lightweight powders with a particle size on the order of tens of micrometers have been investigated. Herein, to theoretically determine the sound absorption coefficient of a fine lightweight powder in the longitudinal vibration mode, it was assumed that the powder was continuum and could be treated as a multiple degree-of-freedom damping vibration system. In addition, the acoustic impedance was calculated by assuming proportional viscous damping to determine the sound absorption coefficient. Finally, the theoretical and experimental values were compared. With the presented theoretical analysis, values close to the experimental results were obtained. Among the three calculated values based on proportional viscous damping, i.e., Rayleigh damping, rigidity proportional damping, and mass proportional damping, the results for Rayleigh damping were the closest to the experimental values.