bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis for Soluble Solid Contents in Pineapples using NIR Spectroscopy
Authors: Abdul Rahim Herlina , Kim Seng Chia , Abdul Rahim Ruzairi
Published: August 2014

This research investigates the use of predictive models and a low cost spectroscopy in non-invasive Soluble Solids Content (SSC) assessment. The challenge is to model complex and high-dimensional spectral data.  Results indicate that the SSC prediction of pineapples harvested on different days using the proposed approach is promising. The second study evaluates common pre-processing practices. Findings indicate that the best accuracy would be achieved when visible spectrum was excluded, second order Savitzky-Golay derivative with the optimal filter length was used, and the absorbance transformation was avoided.
Interchangeable Range of Ozone Concentration Simulation for Low Cost Reconfigurable Brass Gas Cell
Authors: En Marcus Tay Ching , David Michael , Yaacob Maslina , Salim Mohd Rashidi , Ibrahim Mohd Haniff , Ngajikin Nor Hafizah , Azmi Asrul Izam , Idrus Sevia Mahdaliza , Buntat Zolkafle
Published: August 2014

Ultraviolet absorption spectroscopy is reliable for ozone concentration measurement. Concentration range and optical path length are inversely related based on theoretical calculation and observation of previous work. However, gas cells for ozone application are typically not expandable. In addition, they incur cost for custom fabrication. Here we design a reconfigurable brass gas cell that may interchange optical path length between 5.6 cm and 10.8 cm. Components are available at low cost, easy to joint and ready to use. Theoretical background and gas cell structure are discussed. Practical transmittance values between e-0.65 and e-0.05 are proposed for theoretical calculation of concentration via Beer-Lambert law. The concentration values are used in SpectralCalc.com gas cell simulation to obtain transmittance. Both approaches yield comparable result. Simulation result shows concentration range of 5.6 cm optical path length gas cell (31.82 ppm to 413.67 ppm) is wider than concentration range of 10.8 cm optical path length gas cell (16.50 ppm to 214.49 ppm). Simulation condition is at transmittance from 0.5291 to 0.9522, sampling wavelength 253.65 nm, temperature 300 K and pressure 1 atm. Thus, we strongly recommend short optical path length gas cell (5.6 cm) for wide range of concentration measurement (31.82 ppm to 413.67 ppm).
Evolution of Frequency Composition for Atrial Arrhythmias
Authors: A. Ahmad, , S. Buyamin, , J. H. Tuan, , Andre´ Ng G. , F. S. Schlindwein,
Published: August 2014

In the United States of America, cardiac arrhythmias remain the leading cause of sudden death with more than 300,000 cases per year [1, 2]. The majority of sustained cardiac arrhythmias are atrial fibrillation and these contribute a major cause of stroke[3-6]. Irregular electrical pulses can be determined inside the atria. Frequency analysis is used to measure changes in the dominant frequency (DF). Welch method is used here to obtain the frequency spectrum of the signals. The 2D frequency strength plotting allows us to identify the evolution of the frequency composition of the signal with time.In physiological studies, we should see a general frequency increase during stimulation. That means the frequency at pre-stimulation should be lower than during stimulation and this should return to pre-stimulation state after simulation stops. The reason is that stimulation of the ganglia is supposed to promote atrial conduction in AF. The initiation and maintenance of AF is significantly enhanced by simultaneous parasympathetic stimulation In physiological studies, we should see a general frequency increase during stimulation. That means the frequency at pre-stimulation should be lower than during stimulation and this should return to pre-stimulation state after simulation stops. The reason is that stimulation of the ganglia is supposed to promote atrial conduction in AF. The initiation and maintenance of AF is significantly enhanced by simultaneous parasympathetic stimulation.
Edge Detection Algorithm For Enhancement of Linear Back Projection Tomographic Images
Authors: Pusppanathan Jaysuman , Faramarzi Mahdi , Yunus Fazlul Rahman , Nor Ayob Nor Muzakkir , Abdul Rahim Ruzairi , Phang Fatin Aliah , Sheikh Usman Ullah , Pei Ling Leow , Abas Khairul Hamimah , Rahiman Mohd Hafiz Fazalul , Sahlan Shafishuaza
Published: August 2014

Process tomography (PT) is a leading technique for multiphase flow measurement and flow monitoring systems in various fields. PT has the advantage of interpreting acquired measurement data and transforming it into visual tomographic images. The most common method of image reconstruction uses the linear back projection algorithm which often results in blurry images. This paper proposes an enhancement of the reconstructed images using an edge detection image processing technique to convolve with the original image. This filtering technique calculates approximation changes of the horizontal and vertical image derivatives, thus further enhancing image accuracy. Several ultrasonic tomography images were put into a simulation test to validate it. Hence, the image results are being assessed for its performance.
Enhancement of the Response time of a Reflective Type Sensor for Ozone Measurements
Authors: David Michael , En Marcus Tay Ching , Yaacob Maslina , Salim Mohd Rashidi , Hussin Nabihah , Ibrahim Mohd Haniff , Idrus Sevia Mahdaliza , Ngajikin Nor Hafizah , Azmi Asrul Izam
Published: August 2014

Sensor response time T (90) or speed of response is mathematically a function of the rate of diffusion of a gas sample in an absorption spectroscopic gas cell. Increasing the rate of diffusion increases the speed of response and vice versa. In this article, we present the design and analytical results on the response time of a reflective type ozone gas sensor. The variables of length and cross sectional area were interplayed to optimise the rate of diffusion. Two optical reflectors were employed in increasing the path length of the sensor; this resulted in the simultaneous reduction of the effective cell length and an increase in the diameter of the gas cell (cylindrical structure). Ozone diffusion in the 30 cm length of gas cell has been simulated to be 0.01713 ppm cm3/secs in comparison to 0.01023 ppm cm3/sec for a single reflector gas cell, which shows an enhancement of the sensor response time.
Gas Hold-Up Profiles Determination by means of Ultrasonic Transducer
Authors: Rahiman Mohd Hafiz Fazalul , Abdul Rahim Ruzairi , Abdul Rahim Herlina , Zakaria Zulkarnay , Pusppanathan Muhammad Jaysuman , Chiew Loon Goh , Ahmad Nasarudin , Abdul Wahab Yasmin , Rahman Fazlul
Published: August 2014

This paper details a work carried out to measure gas hold-up profiles in a liquid column using a pair of ultrasonic transducer. The gas hold-up profiles from 1.85 mm to 7.7 mm diameter are of interest in this investigation. The measurement setup consist of ultrasonic transducer, an experimental column, signal conditioning circuit, and a digital storage oscilloscope. The experiment was conducted using several gas hold-up profiles and the relationship between the ultrasonic amplitude and the profile were deduced. A finite element analysis was carried out to further verify the results. This paper explains how one could use ultrasonic transducer to estimate the gas hold-up profiles in a liquid column.
Lab-on-Chip Microfluidics System for Single Cell Mass Measurement: A Comprehensive Review
Authors: Rahman Md. Habibur , Ahmad Mohd Ridzuan
Published: August 2014

Single cell mass (SCM) is one of the intrinsic properties of cell and is a vital part of single cell analysis (SCA). To date, a myriad numbers of works has been successfully reported for single cell mass measurement but the reported information are scattered, consequently a comprehensive review becomes mandatory to bring them together. Lab-on-chip microfluidics system integrated with micro-resonator provided an excellent platform to measure single cell mass directly (in presence of cells). On-chip microfluidics system like suspended micro channel resonator (SMR) was reported for non-adherent single yeast cell mass while ‘living cantilever arrays’ (LCA) was proposed to measure adherent HeLa cell mass. On the other hand, cantilever based resonant mass measurement system has non-uniform mass sensitivity; this issue has been overcome by pedestal mass measurement system (PMMS). PMMS has a unique geometrical structure that provided uniform mass sensitivity to the sensing surface. Moreover, we presented a comprehensive discussion of each of the available methods of SCM elaborating the sensing mechanism, geometry of the sensor and governing equations. It is hoped that, information presented in this comprehensive review paper will be a valuable source for the single cell mass analysers and biological researchers.
Miniaturized Planar Sensor Development
Authors: Azmi Aizat , Abdul Rahim Ruzairi , Song Chee Pei , Mohammad Din Shahrulnizahani , Ayob Nor Muzakkir Nor , Ling Leow Pei
Published: August 2014

This paper describes the process of developing a miniature device with planar sensors utilizing electrical capacitance measurement. The project investigates the feasibility and characterization of a miniaturized planar sensor integrated on a polydimethylsiloxane (PDMS) chamber. A 16-planar-electrodes array, with each dimension of the electrode, 4 mm × 2 mm (length × width) was fabricated using a printed circuit board (PCB) technology due to its low cost advantage. The measurement chamber for the sensing area was fabricated using PDMS. The PDMS chamber was bonded on the PCB with a semi cured PDMS to create a round sensing area for sample loading. The mould to develop the PDMS chamber was designed using AutoCAD 2010 and was fabricated using a 3D printer. Capacitance measurement of the planar electrodes was carried out using water as the sample and was validated using a theoretical calculation.  Experimental result shows that the distance of the measured electrodes is inversely proportional to the capacitance value. The range of the measured capacitances of the measurement varies from 10 pF to 20 pF. The result shows that the planar sensors are able to provide capacitance measurement within the miniaturized platform where the measured capacitance showed good agreement with the theoretical calculation.
Rigid and Conductive Dual Nanoprobe for Single Cell Analysis
Authors: Mat Sulaiman Abdul Hafiz , Ahmad Mohd Ridzuan
Published: August 2014

Electrical property characterization of a single cell can be used to infer about its physiological condition, e.g. cell viability.  Due to that, a dual nanoprobe-microfluidic system for electrical properties measurement of single cells has been proposed. This paper is concerned about the mechanical and electrical characterizations of the dual nanoprobe. Electrical and mechanical characterizations were conducted to measure the resistance and the strength of the dual nanoprobe for five different metals i.e. Aluminium, Copper, Silver, Tungsten, and Zinc using finite element approach. From the findings, Tungsten’s nanoprobe has the highest strength while the resistance values for the five materials are not significantly different. Therefore, Tungsten is selected as the most recommended metal for the dual nanoprobe. We also performed single cell electrical measurement to test the functionality of the sensor. This work provides general information of the nanoprobe which can be used as a framework in other applications involving Nano devices i.e. cell surgery and drug delivery.
A Computational Intelligence Approach to Solve the Inverse Problem of Electrical DC Resistivity Sounding
Authors: Wahid H. , Ahmad A.
Published: August 2014

Electrical methods have been widely used in geophysical surveying to obtain high-resolution information about subsurface conditions, since the last few decades. Resistivity is an important parameter in judging the ground properties, especially detecting buried objects of anomalous conductivity. Electrical DC (i.e. Direct Current) resistivity sounding is the commonly used technique to obtain the apparent 2-D resistivity of the region under investigation. Acquiring the true resistivity from collected data remains a complex task due to nonlinearity particularly due to contrasts distributed in the region. In this work, a radial basis function neural network (RBFNN) metamodelling approach is proposed to solve the 2-D resistivity inverse problem. The model was trained with synthetic data samples obtained for a homogeneous medium of 100Ω.m. The neural network was then tested on another set of synthetic data. The results show the ability of the proposed approach to estimate the true resistivity from the 2-D apparent resistivity sounding data with high correlation. The proposed technique, when executed, appears to be computationally-efficient, as it requires less processing time and produces less error than conventional method.
Simulation of Single Cell Trapping Via Hydrodynamic Manipulation
Authors: Ahmad Khalili Amelia , Mohd Basri Mohd Ariffanan , Ahmad Mohd Ridzuan
Published: August 2014

Microfluidic devices are important for the single cell analysis such as cell mechanical and electrical characterization. Single cell characterization could be related to many significant applications including early disease diagnosis. However to perform the single cell manipulation, firstly a single cell have to be isolated and a platform for the cell manipulation have to be provided. One of the methods to trap a single cell is by using hydrodynamic trapping in the microfluidic channel. This study provides a finite element model for single cell trapping for a yeast cell model. The objectives of the simulations are to obtain the appropriate channels’ geometry and optimized ratio of the fluid’s inlet and suction flow rate to trap a single yeast cell. Trap channel was designed to trap a 5μm yeast cell with a suction hole placed in the end of the trap channel. Design geometry and the ratio of fluid flow rates for the cell trapping model were studied using the hydrodynamic resistance concept. The analysis was carried out using numerical solutions from the finite element ABAQUS-FEA software. Using the cell trapping model, a single yeast cell able to be trapped into the trap channel with optimized channel’s suction hole’s geometry and appropriate fluid’s inlet and suction flow rate ratio. The appropriate QTrap/QMain ratio to perform cell trapping using hydrodynamic resistance concept is the ratio value above 1. A 5 μm yeast cell model able to be trap inside a trap channel with the height, width and length of 7 μm by manipulating the suction hole’s flow rate of  1.5 and 2.0 μm of height, 7 and 3 μm of length and width, respectively which situated at the centre edge of the trap channel.
Machining Pits on the Curvature Surface Cup Using Spark Process
Authors: Samion Syahrullail , Daud Md Razak , Yahya Azli , Sapawe Norzahir , Mahmud Nazriah , Hashim Nor Liyana Safura , Nugroho Kartiko
Published: August 2014

In this study, investigations have been conducted using electrical discharge process (die-sinker) to obtain new surface in metal hip implant, which place pit on the surface of curvature cup. A circular array of pit in circle shape was successfully created on the surface of acetabular. There are 8 pits that have been embedded on the surface area of the acetabular by each diameter machine and the depths are 1.1 mm and 0.5 mm respectively. This new surface improvement will prolong the life span of the implant due to lubrication activities in hip tribology.
Utilization and Evaluation of Betalain Pigment from Red Dragon Fruit (Hylocereus Polyrhizus) as a Natural Colorant for Lipstick
Authors: Azwanida N. N. , Normasarah Normasarah , Afandi Asrul
Published: August 2014

Lipstick formulations are most widely used to enhance the beauty of lips. However, current lipcare products are often caused irritation (dry lips, chapped lips and wrinkled lips) to the consumers. The use of synthetic ingredients has also raised safety concern due to adverse health effects in the long term use. The objective of this study was to formulate natural lipsticks by using betalain pigments extracted from Hylocereuspolyrhizus and the lipsticks were evaluated for their organoleptic properties (spreading, hardness, shine and gloss), antimicrobial and antioxidant potential. The organoleptic properties of the formulated lipsticks were found to be satisfactory in order to give attractive beauty to the lips. The antimicrobial activities of the formulated lipstick showed significant inhibition compared to commercial lipsticks and the betalain pigment was proved to have antimicrobial effect. The formulated lipstick showed to have significant antioxidant activities compared to the reference ascorbic acid. In DPPH radical scavenging assay, the IC50 value of the formulated lipstick was 54.29 μg/mL, whereas IC50 value for the reference ascorbic acid was 14.56 μg/mL. As the lipsticks were prepared using natural ingredients like dragon fruit, olive oil and vegetable fat, additional medicinal values were added to the product. Adverse health risk effects as concerned by the consumers was minimized and the product can be used without hesitation and confidence. The lipsticks with the natural ingredients like vegetable fat and olive oil is an alternative to synthetic product and serves as an economical and effective cosmoseutical product.
Preparation and Characterization of Graphene Membrane Electrode Assembly
Authors: Aziz Madzlan , Abdul Halim Farah Syuhada , Jaafar Juhana
Published: August 2014

Fuel cell has been of great demand as power sources for electronic devices. However this has been delayed by the deficiency of catalyst material properties. The aim of this research is to design and synthesis graphene membrane electrode assembly (MEA) as catalyst support in direct methanol fuel cell (DMFC). Graphene was produced from pure graphite powder using chemical reduction method of graphene oxide aqueous solution with a reducing agent. The modified membrane electrode assembly of graphene sulfonated poly (ether ether ketone) (SPEEK) was fabricated for DMFC testing. After the reduction process, the FTIR spectrum showed the disappearance of the carbonyl group of graphene oxide.  XRD spectrum showed a sharp peak at 2θ = 26.4o whichcan be assigned as 002 indexed peak with hexagonal crystal structure. The morphology of graphene observed is a uniform multi layer with crumple flakes and the product has conductivity of as high as 1.36 x 104 S/m. The characteristic of the synthesized graphene membrane electrode assembly suggest potential application in direct methanol fuel cell.
CO2 Absorption in Membrane Contactor using Piperazine, Monoethanolamine and Diethanolamine: A Mass Transfer and Performance Study
Authors: Mohammed H. N. , Ahmad A. L. , Ooi B. S. , Leo C. P.
Published: August 2014

Carbone dioxide has been demonstrated to be the largest component of greenhouse gases, which increases the temperature of the earth’s surface. Therefore, much effort has been endeavor to recover CO2. Recently, polymeric micro-porous membrane contactors have been proposed as an alternative technology for the conventional gas absorption equipments such as bubble column, packed tower and sieve trays column. In this work, three concentrations of aqueous piperazine (PZ) solutions namely 0.2 M, 0.6 M and 1 M in contact with polyvinylidene fluoride (PVDF) capillary membrane. Moreover, the absorption performances were compared with the aqueous solution of 1M monoethanolamine (MEA) and 1 M diethanolamine (DEA). The results revealed that the efficiency of amine solutions in CO2 absorption were according to the order of 1 M PZ > 1 M MEA > 0.6 M PZ > 1 M DEA > 0.2 M PZ. It was found that the efficiency of the system was controlled by the liquid phase resistance which could be improved with the increased of the liquid flow rate.
Removal of Bulk CO2 from Methane with the Presenceof Heavy Hydrocarbon using Polyimide Membrane
Authors: Jusoh N. , Lau K. K. , Shariff A. M.
Published: August 2014

The membrane process has advanced rapidly and continued to progress due to its advantages. Polyimide membrane has been widely applied for gas separation due to their promising permeability and selectivity. In this paper, the effect of heavy hydrocarbon (pentane) in removing bulk CO2 from methane using polyimide membrane was studied. Higher operating pressure and temperature demonstrated the increment of CO2 and CH4 permeance while CO2/CH4 selectivity decreased for both dry and wet conditions. As CO2 concentration increased, CO2 and CH4 permeance as well as CO2/CH4 selectivity enhanced. The presence of pentane in membrane separation contributed to the loss of CO2/CH4 selectivity.
γ-Ray Pre-Irradiated Grafting of Polytetrafluoroethylene Film Membrane
Authors: Idris Alamin , Rahmanian Nejat
Published: August 2014

The changes induced by γ-ray pre-irradiated grafting of polytetrafluoroethylene (PTFE) with alkalo-amines such as Monoethanolamine (MEA), Diethanolamine (DEA) and Methyldiethanolamine (MDEA) solvents were investigated. Samples of the commercially available fluoropolymer, i.e. PTFE film membranes were irradiated with 60Co source γ-radiation with absorbed doses of 30 to 90 kGy. Effects of the grafting conditions of the amines onto the pre-irradiated PTFE, such as grafting time, reaction temperature and pre-irradiation doses on the resulting grafting yield are reported. The grafted PTFE was characterized by the FT-IR spectroscopy and FESEM.The gravimeteric analysis showed that the maximum grafting yield obtained is 2.9% for the 30 kGy irradiated MDEA grafted PTFE (MDEA-g-PTFE)  at 10 min grafting time. However, at 60 min grafting time the maximum grafting yield reduced to 1.05% for the same sample. Consequently, therefore, for the low dose γ-ray pre-irradiated samples, the effects of applied dose and grafting time were found to be remarkably insignificant.
Preparation and Characterization of PVDF-TiO2 Composite Membranes Blended with Different Mw of PVP for Oily Wastewater Treatment using Submerged Membrane System
Authors: Ong C. S. , Lau W. J. , Goh P. S. , Ismail A. F. Ismail
Published: August 2014

Polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration (UF) membranes consisted of TiO2 and different molecular weight (Mw) of polyvinylpyrrolidone (PVP) (i.e. 10, 24, 40 and 360 kDa) were prepared to treat synthesized oily wastewater. The membrane performances were characterized in terms of pure water flux, permeate flux and oil rejection while the membrane morphological properties were studied using SEM and AFM. PVDF-TiO2 composite membrane prepared from PVP40k was found as the optimum membrane due to its high flux and high rejection during filtration process, recording      45 L/m2.h and 80% respectively, when tested using 250 ppm oily solution under submerged condition. The experimental results demonstrated that with increasing Mw of PVP, PVDF-TiO2 membrane had higher protein rejection, smaller porosity and smoother surface layer. With increasing oil concentration from 250 to 1000 ppm, the permeate flux of the PVDF-PVP40k was obviously decreased while the oil rejection was gradually increased due to the additional selective layer formed on the membrane surface.  Based on the findings, the PVDF-TiO2 membrane with PVP40k can be considered as a potential membrane for oily wastewater industry due to the high permeate flux and oil rejection.
Carbon Dioxide (CO2) Separation from Natural Gas using Single-layer and Dual-layer Mixed-matrix Membranes (MMMs)
Authors: Ahmad Siti Halimah , Othman Mohd Hafiz Dzarfan , A Rahman Mukhlis , Jaafar Juhana , Ismail A. F.
Published: August 2014

The present research investigated the utilizing of single and dual-layer flat sheet mixed-matrix membranes (MMMs) for carbon dioxide (CO2) separation. In this research, zeolite 4A is incorporated into a processable polymeric material, polyethersulfone (PES) of MMMs to get the high selectivity and permeability of membrane. Single-layer flat sheet MMMs have been successfully fabricated by adjusting the weight percent of zeolite loading in total solid as the effect of zeolite loading on the performance of MMMs were investigated. It shows that the higher the zeolite loadings, the higher the CO2/CH4 selectivity which is from 1.54 at 0wt % zeolite loading to 3.20 at 20wt % zeolite loading. Besides that, dual-layer flat sheet MMMs was also successfully fabricated with blending of PES and zeolite as selective top-layer and neat PES as sub-layer. Comparison of the results of permeability and selectivity between single and dual layer MMMs with same zeolite loading were studied. The performance of these newly developed dual-layer flat sheet of MMMs gives the best result with CO2/CH4 selectivity for dual layer MMMs is 9.63, tripled of the selectivity of single layer MMMs, 3.20.
Effect of Starch Addition on Microstructure and Strength of Ball Clay Membrane
Authors: Mohamed Bazin Maisarah , Ahmat Muhd Amirudin , Zaidan Nurhanna , Ismail Ahmad Fauzi , Ahmad Norhayati
Published: August 2014

The use of starch as pore-forming agent is one of the frequently used methods to produce porous ceramics membrane with controlled microstructure (porosity and pore size) because corn starch are cheap, non- toxic and environmental friendly. A membrane with the mixture 0–35 wt% of corn starch and ball clay were prepared by compaction process and sintered at 1200°C. Thermal analysis has been done to identify the minimum sintering temperature for ball clay. The sintered membranes show the range value of shrinkage is 4.5–22.76 % and apparent porosity of 9.14–31.83 % depending on the starch content. The pore structures were analyzed by FESEM. The strength of sintered samples was tested by 3-point bending test. The flexural strength reduced from 21–7 MPa. These clay membrane are promising porous ceramic structure for water filtration applications due to their excellent combination physical and mechanical properties.
Separability of embedded surfaces in 3-manifolds
Authors: Przytycki Piotr , Wise Daniel T.
Published: August 2014

We prove that if$\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}S$is a properly embedded$\pi _1$-injective surface in a compact 3-manifold$M$, then$\pi _1S$is separable in$\pi _1M$.
The real Chevalley involution
Authors: Adams Jeffrey
Published: August 2014

The Chevalley involution of a connected, reductive algebraic group over an algebraically closed field takes every semisimple element to a conjugate of its inverse, and this involution is unique up to conjugacy. In the case of the reals we prove the existence of a real Chevalley involution, which is defined over$\mathbb{R}$, takes every semisimple element of$G(\mathbb{R})$to a$G(\mathbb{R})$-conjugate of its inverse, and is unique up to conjugacy by$G(\mathbb{R})$. We derive some consequences, including an analysis of groups for which every irreducible representation is self-dual, and a calculation of the Frobenius Schur indicator for such groups.
Numerical Modeling of Distributed Inhomogeneities and Their Effect on Rolling-Contact Fatigue Life
Authors: Zhou Qinghua , Xie Lechun , Jin Xiaoqing , Wang Zhanjiang , Wang Jiaxu , Keer Leon M. , Wang Qian
Published: August 2014

The present work proposes a new efficient numerical solution method based on Eshelby's equivalent inclusion method (EIM) to study the influence of distributed inhomogeneities on the contact of inhomogeneous materials. Benchmark comparisons with the results obtained with an existing numerical method and the finite element method (FEM) demonstrate the accuracy and efficiency of the proposed solution method. An effective influence radius is defined to quantify the scope of influence for inhomogeneities, and the biconjugate gradient stabilized method (Bi-CGSTAB) is introduced to determine the eigenstrains of a large number of inclusions efficiently. Integrated with a rolling-contact fatigue (RCF) life prediction model, the proposed numerical solution is applied to investigate the RCF life of (TiB + TiC)/Ti-6Al-4V composites, and the results are compared with those of a group of RCF tests, revealing that the presence of the reinforcements causes reduction in the RCF lives of the composites. The comparison illustrates the capability of the proposed solution method on RCF life prediction for inhomogeneous materials.
A Review of Biotransport Education in the 21st Century: Lessons Learned From Experts
Authors: Banerjee Rupak K. , D'Souza Gavin A. , Rylander Christopher , Devireddy Ram
Published: August 2014

The field of bioengineering is relatively new and complex including multiple disciplines encompassing areas in science and engineering. Efforts including the National Science Foundation (NSF) sponsored Integrative Graduate Education and Research Traineeship (IGERT) and VaNTH Engineering Research Center in Bioengineering Educational Technologies have been made to establish and disseminate knowledge and proven methods for teaching bioengineering concepts. Further, the summer bioengineering conference (SBC), sponsored by the American Society of Mechanical Engineers' (ASME) Bioengineering Division, was established to provide a meeting place for engineering educators and students having common interests in biological systems. Of the many subdisciplines of bioengineering, biotransport is a key subject that has wide applicability to many issues in engineering, biology, medicine, pharmacology, and environmental science, among others. The absence of standard content, guidelines, and texts needed for teaching biotransport courses to students motivated the Biotransport committee of ASME's Bioengineering Division to establish a biotransport education initiative. Biotransport education workshop sessions were conducted during the SBC 2011, 2012, and 2013 as part of this initiative. The workshop sessions included presentations from experienced faculty covering a spectrum of information from general descriptions of undergraduate biotransport courses to very detailed outlines of graduate courses to successful teaching techniques. A list of texts and references available for teaching biotransport courses at undergraduate and graduate levels has been collated and documented based on the workshop presentations. Further, based on individual teaching experiences and methodologies shared by the presenters, it was noted that active learning techniques, including cooperative and collaborative learning, can be useful for teaching undergraduate courses while problem based learning (PBL) can be a beneficial method for graduate courses. The outcomes of the education initiative will help produce students who are knowledgeable in the subject of biotransport, facile in applying biotransport concepts for solving problems in various application areas, and comfortable with their own abilities as life-long learners.
Finite-Element Study of the Performance Characteristics of an Intradural Spinal Cord Stimulator
Authors: Grosland Nicole M. , Gillies George T. , Shurig Robert , Stoner Kirsten , Viljoen Stephanus , Dalm Brian D. , Oya Hiroyuki , Fredericks Douglas C. , Gibson-Corley Katherine , Reddy Chandan , Wilson Saul , Howard Matthew A.
Published: August 2014

We have used finite-element (FE) modeling to investigate the mechanical compliance, positional stability and contact pressures associated with a novel type of spinal cord stimulator that is placed directly on the pial surface of the spinal cord in order to more selectively activate neural structures for relief of intractable pain. The properties used in the model are those of the actual prototype devices employed in recent in vitro and chronic in vivo tests. The agreement between predictions and experimental observations serves to validate our FE approach, which can now be used to further optimize the device's design and performance.
Underground Corrosion Model of Steel Pipelines Using In Situ Parameters of Soil
Authors: Mohd Tahir Siti Nor Fariza Mior , Yahaya Nordin , Md Noor Norhazilan , Kar Sing Lim , Abdul Rahman Azlan
Published: August 2014

A simple yet practical model to estimate the time dependence of metal loss (ML) in underground pipelines has been developed considering the in situ soil parameters. These parameters are soil resistivity, pH, moisture content, chloride content, and salinity. The time dependence of the ML was modeled as Pmax = ktn, where t is the time exposure, k is ML constant, and n is the corrosion growth pattern. The results of ML and in situ parameters were analyzed using statistical methods such as data screening, linear correlation analysis, principal component analysis, and multiple linear regressions. The best model revealed that k is principally influenced by ressistivity, and n appears to be correlated with chloride content. Model optimization was carried out by introducing several observation criteria, namely, water access, soil color, and soil texture. The addition of these factors has improved the initial accuracy of model to an R2 score of 0.960. As a conclusion, the developed model can provide immediate assessment of corrosion growth experienced by underground structures.
High Resolution Heat Transfer Measurements on the Stator Endwall of an Axial Turbine
Authors: Laveau Benoit , Abhari Reza S. , Crawford Michael E. , Lutum Ewald
Published: August 2014

In order to continue increasing the efficiency of gas turbines, an important effort is made on the thermal management of the turbine stage. In particular, understanding and accurately estimating the thermal loads in a vane passage is of primary interest to engine designers looking to optimize the cooling requirements and ensure the integrity of the components. This paper focuses on the measurement of endwall heat transfer in a vane passage with a three-dimensional (3D) airfoil shape and cylindrical endwalls. It also presents a comparison with predictions performed using an in-house developed Reynolds-Averaged Navier–Stokes (RANS) solver featuring a specific treatment of the numerical smoothing using a flow adaptive scheme. The measurements have been performed in a steady state axial turbine facility on a novel platform developed for heat transfer measurements and integrated to the nozzle guide vane (NGV) row of the turbine. A quasi-isothermal boundary condition is used to obtain both the heat transfer coefficient and the adiabatic wall temperature within a single measurement day. The surface temperature is measured using infrared thermography through small view ports. The infrared camera is mounted on a robot arm with six degrees of freedom to provide high resolution surface temperature and a full coverage of the vane passage. The paper presents results from experiments with two different flow conditions obtained by varying the mass flow through the turbine: measurements at the design point (ReCax=7.2×105) and at a reduced mass flow rate (ReCax=5.2×105). The heat transfer quantities, namely the heat transfer coefficient and the adiabatic wall temperature, are derived from measurements at 14 different isothermal temperatures. The experimental data are supplemented with numerical predictions that are deduced from a set of adiabatic and diabatic simulations. In addition, the predicted flow field in the passage is used to highlight the link between the heat transfer patterns measured and the vortical structures present in the passage.
Constitutive Relations for Modeling Single Crystal GaN at Elevated Temperatures
Authors: Maniatty Antoinette , Karvani Payman
Published: August 2014

Thermal–mechanical constitutive relations for bulk, single-crystal, wurtzite gallium nitride (GaN) at elevated temperatures, suitable for modeling crystal growth processes, are presented. A crystal plasticity model that considers slip and the evolution of mobile and immobile dislocation densities on the prismatic and basal slip systems is developed. The experimental stress–strain data from Yonenaga and Motoki (2001, “Yield Strength and Dislocation Mobility in Plastically Deformed Bulk Single-Crystal GaN,” J. Appl. Phys., 90(12), pp. 6539–6541) for GaN is analyzed in detail and used to define model parameters for prismatic slip. The sensitivity to the model parameters is discussed and ranges for parameters are given. Estimates for basal slip are also provided.
Aldehyde dehydrogenase-2 regulates nociception in rodent models of acute inflammatory pain
Authors: Zambelli Vanessa O. , Gross Eric R. , Chen Che-Hong , Gutierrez Vanessa P. , Cury Yara , Mochly-Rosen Daria
Published: August 2014

Pain sensitivity can be modulated by an enzyme that degrades aldehydes in rodents, pointing to a promising therapeutic target.
Adult human neural crest–derived cells for articular cartilage repair
Authors: Pelttari Karoliina , Pippenger Benjamin , Mumme Marcus , Feliciano Sandra , Scotti Celeste , Mainil-Varlet Pierre , Procino Alfredo , von Rechenberg Brigitte , Schwamborn Thomas , Jakob Marcel , Cillo Clemente , Barbero Andrea , Martin Ivan
Published: August 2014

HOX
-negative, differentiated neural crest–derived adult cells from the nasal septum display self-renewal capacity and environmental plasticity and are compatible for articular cartilage repair.
Meta-Analyze This
Authors: Kolandaivelu Kumaran
Published: August 2014

Justifying the translation of new findings into practice requires that specified levels of evidence be reached—easier said than done.
Cracking the Metastatic Code
Authors: Lathia Justin D.
Published: August 2014

A comparative analysis reveals a role for cathepsin S in brain metastasis.
A Case of Mistaken Identity: Commensal Bacteria Direct the Antibody Response to HIV
Authors: Round June L.
Published: August 2014

Commensal bacteria induce the production of cross-reactive antibodies against HIV in uninfected individuals.
A Nutrient-Tunable Bistable Switch Controls Motility in Salmonella enterica Serovar Typhimurium
Authors: Koirala Santosh , Mears Patrick , Sim Martin , Golding Ido , Chemla Yann R. , Aldridge Phillip D. , Rao Christopher V.
Published: August 2014

Many bacteria are motile only when nutrients are scarce. In contrast,
Salmonella enterica
serovar Typhimurium is motile only when nutrients are plentiful, suggesting that this bacterium uses motility for purposes other than foraging, most likely for host colonization. In this study, we investigated how nutrients affect motility in
S. enterica
and found that they tune the fraction of motile cells. In particular, we observed coexisting populations of motile and nonmotile cells, with the distribution being determined by the concentration of nutrients in the growth medium. Interestingly,
S. enterica
responds not to a single nutrient but apparently to a complex mixture of them. Using a combination of experimentation and mathematical modeling, we investigated the mechanism governing this behavior and found that it results from two antagonizing regulatory proteins, FliZ and YdiV. We also found that a positive feedback loop involving the alternate sigma factor FliA is required, although its role appears solely to amplify FliZ expression. We further demonstrate that the response is bistable: that is, genetically identical cells can exhibit different phenotypes under identical growth conditions. Together, these results uncover a new facet of the regulation of the flagellar genes in
S. enterica
and further demonstrate how bacteria employ phenotypic diversity as a general mechanism for adapting to change in their environment.

IMPORTANCE
Many bacteria employ flagella for motility. These bacteria are often not constitutively motile but become so only in response to specific environmental cues. The most common is nutrient starvation. Interestingly, in
Salmonella enterica
serovar Typhimurium, nutrients enhance the expression of flagella, suggesting that motility is used for purposes other than foraging. In this work, we investigated how nutrients affect motility in
S. enterica
and found that nutrients tune the fraction of motile cells within a population. Using both experimental and mathematical analysis, we determined the mechanism governing this tunable response. We further demonstrated that the response is bistable: that is, genetically identical cells can exhibit different phenotypes under identical growth conditions. These results reveal a new facet of motility in
S. enterica
and demonstrate that nutrients determine not only where these bacteria swim but also the fraction of them that do so.
Human Factor H (FH) Impairs Protective Meningococcal Anti-FHbp Antibody Responses and the Antibodies Enhance FH Binding
Authors: Costa Isabella , Pajon Rolando , Granoff Dan M.
Published: August 2014

The meningococcal 4CMenB vaccine (Bexsero; Novartis) contains four antigens that can elicit serum bactericidal activity, one of which is factor H (FH)-binding protein (FHbp). FHbp specifically binds human complement FH. When humans are immunized, FHbp is expected to form a complex with FH, which could affect immunogenicity and safety. Wild-type mice (whose FH does not bind to FHbp) and human FH transgenic mice were immunized with three doses of 4CMenB, and their responses were compared. There were no significant differences between the serum bactericidal responses of transgenic and wild-type mice to strains with all of the antigens mismatched for 4CMenB except PorA or NadA. In contrast, against a strain mismatched for all of the antigens except FHbp, the transgenic mice had 15-fold weaker serum bactericidal antibody responses (P= 0.0006). Binding of FH downregulates complement. One explanation for the lower anti-FHbp serum bactericidal activity in the transgenic mice is that their postimmunization serum samples enhanced the binding of FH to FHbp, whereas the serum samples from the wild-type mice inhibited FH binding. Control antiserum from transgenic mice immunized with a low-FH-binding mutant FHbp (R41S) vaccine inhibited FH binding. Two 4CMenB-vaccinated transgenic mice developed serum IgM autoantibodies to human FH. Thus, human FH impairs protective serum anti-FHbp antibody responses, in part by skewing the antibody repertoire to FHbp epitopes outside the FH binding site. FHbp vaccines that bind FH may elicit FH autoantibodies. Mutant FHbp antigens with low FH binding could improve protection and, potentially, vaccine safety in humans.

IMPORTANCETwo serogroup B meningococcal vaccines contain a novel antigen called factor H (FH)-binding protein (FHbp). FHbp specifically binds human FH, a plasma protein that downregulates complement. One vaccine (4CMenB; Novartis) is licensed in Europe, Canada, and Australia. When humans are immunized, FHbp can complex with FH. We compared the immunogenicity of 4CMenB vaccine in wild-type mice, whose own FH does not bind to FHbp, and human FH transgenic mice. Transgenic mice had respective antibody responses similar to those of wild-type mice to 4CMenB antigens that do not bind FH. However, the protective antibody responses of the transgenic mice to FHbp were impaired, largely because the antibodies did not inhibit but rather enhanced the binding of FH to FHbp. Two transgenic mice developed serum IgM autoantibodies to FH. Mutant FHbp antigens with low FH binding likely will elicit greater protection in humans than FHbp vaccines that bind FH and have a lower risk of FH autoantibodies.
Vitamin D supplementation in neonates
Authors: Wu Zhe
Published: August 2014

Vitamin D deficiency may lead to the development of rickets. In our paediatrics department in a major London hospital, we audited the number of babies with low vitamin D levels attending our prolonged jaundice clinic. Prior to our newly designed intervention, those babies with low vitamin D levels would be given a letter to encourage collection of supplementation from their GP. The GP would receive a letter which included a 14-page guideline on vitamin D supplementation.

For this project, we included all breastfed babies that attended our prolonged jaundice clinic between August 2012 and December 2012. Those babies that were either vitamin D deficient or insufficient were identified. We then followed up these patients and asked them whether they were being prescribed the correct supplementation after being identified as vitamin deficient. For our intervention, we designed a leaflet to simplify guidelines that was then distributed to mothers and their GPs. Following this intervention, we re-audited the new cohort of patients who received the leaflet between August and November 2013.

The study found 71% of babies to be vitamin D deficient. Moreover, almost two in five mothers had less than the recommended six months of vitamin supplementation during pregnancy. After identifying a deficiency, one would expect that uptake of vitamin supplementation would increase dramatically. However, only four in 10 babies went on to receive the correct dose and preparation of supplements. A marked increase in uptake was seen during the re-audit post intervention, with 71% of babies receiving correct supplementation.

While an increase in government advertising would have contributed to the rise in uptake of vitamin D supplementation, a leaflet proved to be a simple yet effective intervention in improving vitamin uptake in babies. As a result, this was then implemented as part of trust guidelines.
Some minisuperspace model for the Faddeev formulation of gravity
Authors: Khatsymovsky V. M.
Published: August 2014

We consider Faddeev formulation of General Relativity (GR) in which the metric is composed of ten vector fields or a 4 ×10 tetrad. This formulation reduces to the usual GR upon partial use of the field equations.

A distinctive feature of the Faddeev action is its finiteness on the discontinuous fields. This allows to introduce its minisuperspace formulation where the vector fields are constant everywhere on ℝ4 with exception of a measure zero set (the piecewise constant fields). The fields are parametrized by their constant values independently chosen in, e.g. the 4-simplices or, say, parallelepipeds into which ℝ4 can be decomposed. The form of the action for the vector fields of this type is found.

We also consider the piecewise constant vector fields approximating the fixed smooth ones. We check that if the regions in which the vector fields are constant are made arbitrarily small, the minisuperspace action and equations of motion tend to the continuum Faddeev ones.
Compiling CSPs: A Complexity Map of (Non-Deterministic) Multivalued Decision Diagrams
Authors: Amilhastre Jérôme , Fargier Hélène , Niveau Alexandre , Pralet Cédric
Published: August 2014

Constraint Satisfaction Problems (CSPs) offer a powerful framework for representing a great variety of problems. The difficulty is that most of the requests associated with CSPs are NP-hard. When these requests have to be addressed online, Multivalued Decision Diagrams (MDDs) have been proposed as a way to compile CSPs.

In the present paper, we draw a compilation map of MDDs, in the spirit of the NNF compilation map, analyzing MDDs according to their succinctness and to their tractable transformations and queries. Deterministic ordered MDDs are a generalization of ordered binary decision diagrams to non-Boolean domains: unsurprisingly, they have similar capabilities. More interestingly, our study puts forward the interest of non-deterministic ordered MDDs: when restricted to Boolean domains, they capture OBDDs and DNFs as proper subsets and have performances close to those of DNNFs. The comparison to classical, deterministic MDDs shows that relaxing the determinism requirement leads to an increase in succinctness and allows more transformations to be satisfied in polynomial time (typically, the disjunctive ones). Experiments on random problems confirm the gain in succinctness.