bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-Dose Paclitaxel-Coated Balloon Angioplasty versus Uncoated Percutaneous Transluminal Balloon Angioplasty for Femoropopliteal Peripheral Artery Disease: 6-Month Results in a Tertiary Care Hospital of Central India
Authors: Rathod Jawahar , Gour Prajwaleet , Saha Subinay , Jaybhay Shivprasad , Verma Rohit
Published: July 2019

Introduction Superficial femoral and popliteal arteries are the most common locations of peripheral vascular disease (PVD). Endovascular interventional therapy including drug-coated balloon (DEB) angioplasty or percutaneous transluminal angioplasty (PTA) and stenting are important options for treatment of PVD.

Aims and Objectives The main objective is to compare the efficacy of DEB over PTA with optional stenting in management of obstructive femoropopliteal lesions in terms of 6-month patency rate.

Materials and Methods The clinical experimental study was carried out in a tertiary care center over duration of 2 years. All symptomatic patients having lower limb PVD in femoropopliteal segment were included. Total 37 patients were included in this study in which 16 underwent plain balloon angioplasty (with 3 patients undergoing bare metal stenting [BMS]) and 21 additional underwent DEB angioplasty. Patients with previously intervened lesions, primary lesion failure, major ischemic tissue loss, poor aortoiliac or common femoral inflow, or end-stage kidney disorders were excluded.

Result At 1-month follow-up, patency rates in DEB and conventional PTA ± BMS were 85.71% and 87.5%, respectively. On 6-month follow-up, patency rates were found to be 71.4% versus 37.5%, respectively (p = 0.039; significant). In case of occluded lesions, on 6-month follow-up, patency rate in DEB group was higher than that in plain balloon group (66.7% vs. 25%). In both the cohorts, success rate, i.e., patency rates were more in short and intermediate length lesions than long segment lesions. DEB was found to be superior to plain angioplasty with optional stenting in terms of 6-month patency rate.
Intrinsic current overshoot during thermal-runaway threshold switching events in TaOx devices
Authors: Goodwill Jonathan M. , Skowronski Marek
Published: July 2019

The response of a TiN/TaOx/TiN S-type threshold switching device to a rectangular source voltage pulse was simulated using an electrothermal finite element model. At the start of the pulse, the current density within the device was uniform. As the device transitioned to the steady state, the current followed the load line of the series resistor and the current density became increasingly more constricted. Unexpectedly, the temperature and current density evolution was not monotonic. At low values of the load resistor, the current density constricted more during the transition than at the steady state. The temperature at the point of maximum constriction can exceed the steady state temperature by 100 °C if the time of the threshold switching event is shorter than the thermal time constant of the device. The magnitude of the overshoot decreases with decreasing device size. The reported effect can have a significant impact on the reliability of threshold switches and the electroformation of memory devices.
Acoustic birefringence via non-Eulerian metamaterials
Authors: Zangeneh-Nejad Farzad , Fleury Romain
Published: July 2019

The recently proposed concept of metamaterials has opened exciting venues to control wave-matter interactions in unprecedented ways. Here, we demonstrate the relevance of metamaterials for inducing acoustic birefringence, a phenomenon which has already found its versatile applications in optics in designing light modulators or filters, and nonlinear optic components. This is achieved in a suitably designed acoustic metamaterial which is non-Eulerian, in the sense that at low frequencies, it cannot be homogenized to a uniform acoustic medium whose behavior is characterized by the Euler equation. Thanks to the feasibility of engineering its subwavelength structure, such a non-Eulerian metamaterial allows one to desirably manipulate the birefringence process. Our findings may give rise to the generation of novel devices such as tunable acoustic splitters and filters.
Stacking order-dependent sign-change of microwave phase due to eddy currents in nanometer-scale NiFe/Cu heterostructures
Authors: Gladii O. , Seeger R. L. , Frangou L. , Forestier G. , Ebels U. , Auffret S. , Baltz V.
Published: July 2019

In the field of spintronics, ferromagnetic/nonmagnetic metallic multilayers are core building blocks for emerging technologies. Resonance experiments using stripline transducers are commonly used to characterize and engineer these stacks for applications. Up to now in these experiments, the influence of eddy currents on the excitation of the dynamics of ferromagnetic magnetization below the skin-depth limit was most often neglected. Here, using a coplanar stripline transducer, we experimentally investigated the broadband ferromagnetic resonance response of NiFe/Cu bilayers a few nanometers thick in the sub-skin-depth regime. Asymmetry in the absorption spectrum gradually built up as the excitation frequency and Cu-layer thickness increased. Most significantly, the sign of the asymmetry depended on the stacking order. Experimental data were consistent with a quantitative analysis considering the eddy currents generated in the Cu layers and the subsequent phase shift of the feedback magnetic field generated by the eddy currents. These results extend our understanding of the impact of eddy currents below the microwave magnetic skin-depth and explain the line shape asymmetry and phase lags reported in stripline experiments.
Ultrafast saturable absorption dynamics in hybrid graphene/Si3N4 waveguides
Authors: Demongodin Pierre , El Dirani Houssein , Lhuillier Jérémy , Crochemore Romain , Kemiche Malik , Wood Thomas , Callard Ségolène , Rojo-Romeo Pedro , Sciancalepore Corrado , Grillet Christian , Monat Christelle
Published: July 2019

We study the nonlinear optical properties of graphene integrated onto Si3N4 waveguides under picosecond and subpicosecond pulsed excitation at telecom wavelength. Saturable absorption of graphene under guided-mode excitation is measured, and the temporal effects related to the photoexcited carrier dynamics in graphene are highlighted. Thereafter, a model of photoexcited carriers in graphene is implemented into the nonlinear Schrödinger equation in order to simulate the pulse propagation across the hybrid graphene/Si3N4 waveguide. This allows us to extract phenomenological parameters of graphene saturable absorption in chip-based devices, which could provide some guidelines for the design of nonlinear elements in photonic integrated circuits.
Using SCF metadynamics to extend density matrix embedding theory to excited states
Authors: Tran Henry K. , Van Voorhis Troy , Thom Alex J. W.
Published: July 2019

A new framework based on density matrix embedding theory (DMET) capable of directly targeting excited electronic states is proposed and implemented. DMET has previously been shown to be an effective method of calculating the ground state energies of systems exhibiting strong static correlation but has never been applied to calculate excited state energies. In this work, the Schmidt decomposition is applied directly on excited states, approximated by higher lying self-consistent field solutions. The DMET prescription is applied following this Schmidt decomposition allowing for a direct embedding of excited states. Initial results are obtained for a system of multiple hydrogen dimers and the lithium hydride dissociation. We analyze the nature of each part of the excited state DMET calculation and identify challenges. These challenges to the implementation of excited state DMET are discussed, and potential suggestions moving forward are recommended.
Heat capacity and electrical conductivity of plasmon excitations
Authors: Akbari-Moghanjoughi M.
Published: July 2019

In this research, we calculate the heat capacity and electrical conductivity of plasmon excitations in an arbitrary degenerate electron gas by using the linearized Schrödinger-Poisson model. It is shown that the large heat capacity of electron fluid such as in metals can be attributed to the collective excitations. These excitations unlike those for low energy fermion excitations dominant at low temperatures follow the Bose-Einstein statistics and contribute significantly at higher temperatures where a significant number of electrons excite to energy levels beyond twice the plasmon energy of electron fluid. The current density and electrical conductivity of plasmon excitations in the current model show unique features for characteristic current-voltage and their temperature dependence. It is found that a single electron fermion excitation model such as the one used in free electron assumption is not appropriate for a full description of electron contribution to the physical properties of metals and plasmas at very high temperatures. The coupled pseudoforce system with a periodic density structure in the presence of a uniform electric field is also considered with appropriate boundary conditions to evaluate the characteristic aspects of collective excitations in a one dimensional plasmonic crystal. The application of the lattice periodicity on the wavefunction and the electrostatic potential results in singularities for the probability current due to plasmon excitations. It is shown that such an effect persists with an arbitrary ion core potential function which obeys the lattice periodicity. The current model clearly demonstrates the importance of collective electronic excitation in the physical properties of electron gas with an arbitrary degree of degeneracy.
Simulation of Io’s plumes and Jupiter’s plasma torus
Authors: McDoniel William J. , Goldstein David B. , Varghese Philip L. , Trafton Laurence M.
Published: July 2019

Io is a highly volcanic satellite of Jupiter. Its giant plumes rise hundreds of kilometers, creating large targets for incoming ions as Jupiter’s plasma torus overtakes Io in its orbit. Neutral material from Io’s sublimation atmosphere and volcanic plumes supplies the plasma torus, but the details of the interaction between neutral gas at Io and ions in the torus are not well understood. This paper suggests a process by which plume material is energized and ionized so as to supply the torus. We present three-dimensional direct simulation Monte Carlo simulations of giant plumes being bombarded by S+ and O+ ions which are moved based on precomputed electric and magnetic fields. The dependence of the plume/plasma interaction on the plume’s location on Io is investigated. The plume/plasma interaction is seen to be asymmetric even for a plume at the subplasma point because of the electric field that arises in an Io-fixed reference frame. Plasma is found to inflate and heat plume canopies and to give rise to a large, diffuse neutral cloud over the plume’s entire hemisphere. We also find that plasma can explain the thickness of red deposition rings observed on Io.
Atomistic modelling of diamond-type SixGeyCzSn1−x−y−z crystals for realistic transmission electron microscopy image simulations
Authors: Jaillet Leonard , Guedj Cyril , Redon Stephane
Published: July 2019

The realistic simulation of transmission electron microscopy (TEM) images requires an accurate definition of the positions of all atoms, which are linked to the mechanical properties of the material. This paper proposes an optimized atomistic modeling approach to model the lattice parameters and elastic properties of Si, Ge, diamond, alpha-tin, and related diamond alloys, with an approach compatible with systems bigger than 50000 atoms. In order to compute precisely the elastically strained SixGeyCzSn1−x−y−z diamond crystals, a dedicated parameterization of the Keating force field is provided. An original periodic boundary strategy is provided. Our tool is successfully used to interpret experimental TEM data with a reasonable accuracy and precision in a time scale about 10000 times faster than ab initio methods. The method predicts the correct lattice parameters and elastic constants of elementary compounds and alloys with a deviation inferior to 8.1%. We show that subsequent Monte-Carlo simulations predict original self-ordering effects in C in good agreement with the theory. An original approach is used to quantify the short-range and long-range order in comparison with high-resolution cross-sectional TEM experiments: the projected radial distribution function (p-RDF) appears to be a universal and very sensitive analytical tool to quantify the matching between our atomistic model and the experimental HR(S)TEM results. For our reference Si-Ge multilayer with 20 millions of atoms, a maximum broadening of 100 pm is obtained for the third-nearest neighbor (3nn) simulated peak of the p-RDF compared to the experimental one. The same value is obtained from a template matching analysis of the maximum local displacements between the projected experimental atomic positions and the corresponding simulation.
Biophysical phenotyping of cells via impedance spectroscopy in parallel cyclic deformability channels
Authors: Ren Xiang , Ghassemi Parham , Strobl Jeannine S. , Agah Masoud
Published: July 2019

This paper describes a new microfluidic biosensor with capabilities of studying single cell biophysical properties. The chip contains four parallel sensing channels, where each channel includes two constriction regions separated by a relaxation region. All channels share a pair of electrodes to record the electrical impedance. Single cell impedance magnitudes and phases at different frequencies were obtained. The deformation and transition time information of cells passing through two sequential constriction regions were gained from the time points on impedance magnitude variations. Constriction channels separated by relaxation regions have been proven to improve the sensitivity of distinguishing single cells. The relaxation region between two sequential constriction channels provides extra time stamps that can be identified in the impedance plots. The new chip allows simultaneous measurement of the biophysical attributes of multiple cells in different channels, thereby increasing the overall throughput of the chip. Using the biomechanical parameters represented by the time stamps in the impedance results, breast cancer cells (MDA-MB-231) and the normal epithelial cells (MCF-10A) could be distinguished by 85%. The prediction accuracy at the single-cell level reached 97% when both biomechanical and bioelectrical parameters were utilized. While the new label-free assay has been tested to distinguish between normal and cancer cells, its application can be extended to include cell–drug interactions and circulating tumor cell detection in blood.
Tunable elastic metamaterials using rotatable coupled dual-beam resonators
Authors: Lv Xu-Feng , Chuang Kuo-Chih , Erturk Alper
Published: July 2019

We present the theoretical background, finite element and spectral element analyses, and experimental validation of a new class of tunable elastic metamaterials which leverage coupled dual-beam resonators that cancel in-phase bending vibration of each beam section. For a metamaterial with an array of rotatable single-beam resonators, we first show that the orthogonal bending modes of each resonator merely cause the shrinkage of one bandgap and the expansion of the other with changing resonator angle. Then, by simply rotating the coupled dual beams while keeping the joint tip mass stationary, we demonstrate that the bandgap of the host elastic metamaterial with an array of coupled dual-beam resonators can be continuously tuned over a wide range of frequencies. While canceling the undesired lateral bending motions, we enable tunable elastic metamaterials through altering the moment of inertia of the beam-type resonator attachments. Continuous bandgap tuning over a broad frequency range is validated experimentally, yielding a 42% change in the starting frequency of the bandgap as the coupled dual-beam resonators are rotated from 0° to 90°. Although passive tuning is considered in our work, active components can be incorporated in the proposed design to enable adaptive tuning as well as time-varying behavior.
Self-heating of relaxor and ferroelectric ceramics during electrocaloric field cycling
Authors: Bradeško Andraž , Hedl Ana , Fulanović Lovro , Novak Nikola , Rojac Tadej
Published: July 2019

Electrocaloric (EC) materials are prominent candidates for new generations of scalable and green refrigeration devices. While most often the research on EC materials has been focused on achieving high magnitudes of the EC temperature change, little is known about electrical losses and self-heating effects, despite playing a critical role in the cooling performance of these materials. Here, we analyzed the behavior of a set of ceramic materials under EC-device-like electric-field-driving conditions. The EC temperature response was studied focusing on the contributions to the self-heating in three different compositions: relaxor Pb(Mg1/3Nb2/3)O3 and two different (undoped and Nb-doped) rhombohedral ferroelectric Pb(Zr,Ti)O3 compositions. The specific relaxor and ferroelectric nature of the analyzed materials enabled us to separate the different contributions, such as domain switching and electrical conductivity, to their EC responses. We show that besides having a large EC temperature change, low electrical losses, leading to reduced self-heating effects, are another key parameter to be considered in the engineering of materials for future EC cooling devices.
Charge carrier injection and transport in QLED layer with dynamic equilibrium of trapping/de-trapping carriers
Authors: Kim Sun-Kyo , Kim Yong-Seog
Published: July 2019

A theoretical analysis on carrier injection and transport through layers of quantum dot light emitting display (QLED) device was attempted assuming dynamic equilibrium of trapping and detrapping charge carriers. Assuming traps in exponential or Gaussian energy distribution, the effect of parameters on the current-voltage relationship for the device was investigated. The energy level and distribution of charge traps, a Schottky barrier, and the ratio of detrapping rate constant to the trapping rate constant were found to affect the current-voltage relationship significantly in the charge transport layer. The results suggest that the parameters must be modulated simultaneously in order to achieve a charge balance in the quantum dot layer of the QLED device.
Insights into the interfacial bonding strength of TiB/Ti: A first principles study
Authors: Fan Rui , Zheng Qiwen , Liu Yue , Fan Tongxiang
Published: July 2019

First-principles calculations are performed to study the strength and nature of interfacial bonding at TiB/Ti interfaces. Sixteen (100)TiB/(101¯0)α-Ti interface models considering different (100)TiB terminations and stacking sites are investigated to determine their influence on the interfacial bonding strength and thermodynamic stability. The L bridge-site-B1-termination interface exhibits the strongest interfacial bonding and the most stable structure, forming strong Ti–B polar covalent bonds and maintaining the same epitaxial stacking sequence as bulk TiB at the interface. Moreover, seven alloying elements commonly used in titanium alloys are investigated to tailor the interfacial bonding strength of TiB/Ti interfaces. The calculated results indicate that the alloying elements of V, Cr, and Mo form stronger chemical bonds with B atoms than with Ti and have the tendency to aggregate at the TiB/Ti interface region, while improving its interfacial bonding strength. The alloying elements of Al, Si, Zr, and Sn generate weaker chemical bonds with B atoms and preferentially aggregate at sites away from the TiB/Ti interface. This tends to maintain or even lower the interfacial bonding strength of the interface. The calculated results, especially for V, are in good agreement with previous experimental observations. It is believed that the calculated results can provide theoretical evidence to guide experimental designs and improve the interfacial and macromechanical properties of TiB-reinforced titanium matrix composites.
Resolving the three-dimensional structure of particles that are aerodynamically clustered by a turbulent flow
Authors: Lau Timothy C. W. , Frank Jonathan H. , Nathan Graham J.
Published: July 2019

We report the first definitive experimental measurement of the four-dimensional (three spatial and one temporal) structure of particles that are aerodynamically clustered. High-speed tomographic imaging of a particle-laden turbulent flow was utilized to detect the temporal evolution of particle clusters at the exit of a long pipe. The measurements confirm that the particle clusters are coherent and ropelike in shape, rather than sheetlike, resolving a question that was not possible to address from previous two-dimensional measurements. These clusters are present right from the exit plane, where they are preferentially located near the jet edge, suggesting that they are generated inside the pipe close to the pipe wall.
Bond energy of ThN+: A guided ion beam and quantum chemical investigation of the reactions of thorium cation with N2 and NO
Authors: Cox Richard M. , Kafle Arjun , Armentrout P. B. , Peterson Kirk A.
Published: July 2019

Kinetic-energy dependent reactions of Th+ with N2 and NO are studied using a guided ion beam tandem mass spectrometer. The formation of ThO+ in the reaction of Th+ with NO is observed to be exothermic and barrierless with a reaction efficiency at low energies of 0.91 ± 0.18. Formation of ThN+ in the reactions of Th+ with N2 and NO is endothermic in both cases. The kinetic-energy dependent cross sections for formation of this product ion were evaluated to determine a 0 K bond dissociation energy (BDE) of D0(Th+–N) = 6.51 ± 0.08 eV, the first direct measurement of this BDE. Additionally, the reactions were explored by quantum chemical calculations, including a full Feller-Peterson-Dixon composite approach with correlation contributions up to CCSDTQ for ThN and ThN+, as well as more approximate CCSD(T) calculations where a semiempirical model was used to estimate spin-orbit energy contributions. The ThN+ BDE is found to be larger than those of the transition metal congeners, TiN+ along with estimated values for ZrN+ and HfN+, believed to be a result of the actinide contraction.
Credit assignment to state-independent task representations and its relationship with model-based decision making
Authors: Shahar Nitzan , Moran Rani , Hauser Tobias U. , Kievit Rogier A. , McNamee Daniel , Moutoussis Michael ,   NSPN Consortium, Dolan Raymond J. , Bullmore Edward , Dolan Raymond , Goodyer Ian , Fonagy Peter , Jones Peter , Moutoussis Michael , Hauser Tobias , Neufeld Sharon , Romero-Garcia Rafael , St Clair Michelle , Vértes Petra , Whitaker Kirstie , Inkster Becky , Prabhu Gita , Ooi Cinly , Toseeb Umar , Widmer Barry , Bhatti Junaid , Villis Laura , Alrumaithi Ayesha , Birt Sarah , Bowler Aislinn , Cleridou Kalia , Dadabhoy Hina , Davies Emma , Firkins Ashlyn , Granville Sian , Harding Elizabeth , Hopkins Alexandra , Isaacs Daniel , King Janchai , Kokorikou Danae , Maurice Christina , McIntosh Cleo , Memarzia Jessica , Mills Harriet , O’Donnell Ciara , Pantaleone Sara , Scott Jenny , Fearon Pasco , Suckling John , van Harmelen Anne-Laura , Kievit Rogier
Published: July 2019

Model-free learning enables an agent to make better decisions based on prior experience while representing only minimal knowledge about an environment’s structure. It is generally assumed that model-free state representations are based on outcome-relevant features of the environment. Here, we challenge this assumption by providing evidence that a putative model-free system assigns credit to task representations that are irrelevant to an outcome. We examined data from 769 individuals performing a well-described 2-step reward decision task where stimulus identity but not spatial-motor aspects of the task predicted reward. We show that participants assigned value to spatial-motor representations despite it being outcome irrelevant. Strikingly, spatial-motor value associations affected behavior across all outcome-relevant features and stages of the task, consistent with credit assignment to low-level state-independent task representations. Individual difference analyses suggested that the impact of spatial-motor value formation was attenuated for individuals who showed greater deployment of goal-directed (model-based) strategies. Our findings highlight a need for a reconsideration of how model-free representations are formed and regulated according to the structure of the environment.
Exosomes regulate neurogenesis and circuit assembly
Authors: Sharma Pranav , Mesci Pinar , Carromeu Cassiano , McClatchy Daniel R. , Schiapparelli Lucio , Yates John R. , Muotri Alysson R. , Cline Hollis T.
Published: July 2019

Significance

Exosomes have been implicated in intercellular communication in cancer and neurodegenerative disorders. We explored their function in brain development. Proteomic analysis demonstrated that exosomes from isogenic control cultures contain neurodevelopmental signaling proteins, which are lacking in exosomes from MECP2 loss-of-function (MECP2LOF) cultures. Treating MECP2LOF neural cultures with control exosomes rescues neurodevelopmental deficits, increasing neurogenesis, synaptogenesis, and network activity. Exosomes function similarly in vivo: injecting purified exosomes into the lateral ventricles of P4 mouse brains increased hippocampal neurogenesis. These findings significantly advance the field by demonstrating that neural exosomes contain diverse protein cargo predicted to affect multiple outcome measures of neural development and that exosomes signal between cells in developing neural circuits to promote neural circuit development and function.
Genetic control of male production in
Daphnia pulex
Authors: Ye Zhiqiang , Molinier Cécile , Zhao Chaoxian , Haag Christoph R. , Lynch Michael
Published: July 2019

Daphnia
normally reproduce by cyclical parthenogenesis, with offspring sex being determined by environmental cues. However, some females have lost the ability to produce males. Our results demonstrate that this loss of male-producing ability is controlled by a dominant allele at a single locus. We identified the locus by comparing whole-genome sequences of 67 nonmale-producing (NMP) and 100 male-producing (MP) clones from 5
Daphnia pulex
populations, revealing 132 NMP-linked SNPs and 59 NMP-linked indels within a single 1.1-Mb nonrecombining region on chromosome I. These markers include 7 nonsynonymous mutations, all of which are located within one unannotated protein-coding gene (gene 8960). Within this single gene, all of the marker-linked NMP haplotypes from different populations form a monophyletic clade, suggesting a single origin of the NMP phenotype, with the NMP haplotype originating by introgression from a sister species,
Daphnia pulicaria
. Methyl farnesoate (MF) is the innate juvenile hormone in daphnids, which induces the production of males and whose inhibition results in female-only production. Gene 8960 is sensitive to treatment by MF in MP clones, but such responsiveness is greatly reduced in NMP clones. Thus, we hypothesize that gene 8960 is located downstream of the MF-signaling pathway in
D. pulex
, with the NMP phenotype being caused by expression change of gene 8960.
Refractive index sensor based on high-order surface plasmon resonance in gold nanofilm coated photonic crystal fiber*
Authors: Fan Zhen-Kai , Fang Shao-Bo , Li Shu-Guang , Wei Zhi-Yi
Published: July 2019

We propose a novel kind of wide-range refractive index optical sensor based on photonic crystal fiber (PCF) covered with nano-ring gold film. The refractive index sensing performance of the PCF sensor is analyzed and simulated by the finite element method (FEM). The refractive index liquid is infiltrated into the cladding air hole of the PCF. By comparing the sensing performance of two kinds of photonic crystal fiber structures, a wide range and high sensitivity structure is optimized. The surface plasmon resonance (SPR) excitation material is chose as gold, and large gold nanorings are embedded around the first cladding air hole of the PCF. The higher order surface plasmon modes are generated in this designed optical fiber structure. The resonance coupling between the fundamental mode and the 5th order surface plasmon polariton (SPP) modes is excited when the phase matching condition is matched. Therefore, the 3rd loss peaks appear obvious red-shift with the increase of the analyte refractive index, which shows a remarkable polynomial fitting law. The fitnesses of two structures are 0.99 and 0.98, respectively. When the range of refractive indices is from 1.40 to 1.43, the two kinds of sensors have high linear sensitivities of 1604 nm/RIU and 3978 nm/RIU, respectively.
Estimation of fuel temperature reactivity coefficient of a research reactor using ANFIS
Authors: Mohd Ali Nur Syazwani , Hamzah Khaidzir , Idris Faridah Mohamad , Alang Md Rashid Nahrul Khair , Minhat Mohamad Sabri , Rabir Mohamad Hairie
Published: July 2019

Fuel Temperature reactivity coefficient is one of the important operational and safety parameters in nuclear reactors to monitor for normal operation and transient safety analysis in research as well as in power reactors. The aim of this work is to estimate the temperature reactivity coefficient by using adaptive neuro-fuzzy inference system (ANFIS) as a preliminary assessment for developing an online monitoring system in research reactors such as the Reactor TRIGA PUSPATI (RTP). The input for the learning mechanism is the fuel temperature recorded at Ch A of the instrumented fuel element (IFE) and control rod positions with the fuel temperature reactivity coefficient as the targeted output. The ANFIS model was validated using testing data that consisted of fuel temperature measured at Ch B and results on -0.00571 $°C−1 (-3.997 pcm°C−1) of actual output and -0.00592 $°C−1 (4.144 pcm°C−1) of predicted output. Through the developed model, it showed that the ANFIS also can be used as a tool to estimate the fuel temperature reactivity coefficient with good prediction and accuracy shown from the calculation of mean absolute error (MAE) of 0.00349.
Performance analysis of random sampling algorithms on GNU Octave
Authors: Bin Yazid Mohd Syahmi , Lemaire Matthieu , Mohd Sies Mohsin bin , Lee Deokjung
Published: July 2019

This paper presents the performance analysis of two random sampling algorithms, the inverse-transform method and the Vose aliasing method, on GNU Octave. The Monte Carlo code MCS developed by UNIST uses random sampling methods to simulate the physics of neutron and photon transport [1]. The goal is to optimize the sampling time of MCS for cases when the probability density function is a constant function throughout the simulation. For this purpose, the runtime of the inverse-transform method and Vose aliasing method are compared for increasing input size with scripts developed on GNU Octave. To compare the execution time, the initialization and generation time of both methods are determined and discussed.
Preliminary quantitative feasibility analysis of proposed Thorium-based nuclear reactor
Authors: Muhamad Pauzi Anas , Abdul Wahid Azril Wasim , Md Saad Juniza
Published: July 2019

In the beginning of the 21st century, several research institutions and also private companies had proposed various design of thorium-based nuclear reactor, ranging from solid fuel to molten fuel, fast and thermal neutron spectrum and also various path of waste management. This paper studies 10 of the proposed reactor designs by 10 different organizations, three key aspects analysed quantitatively namely price per kilowatt, safety features and spent fuel managements. Corresponding factors contributing to the key aspects mentioned above were gathered, weighted based on evidence available and analysed using decision matrix. Based on the information collected, preliminary ranking were constructed based on trends between various factors.
Identifying the possible source regions of elevated concentrations of Xenon-133 detected at the Takasaki Radionuclide Monitoring Station (JPX38) on 2 October 2017: Malaysian CTBT National Data Centre (MY-NDC) findings
Authors: Rashid F I A , Zolkaffly M Z
Published: July 2019

A couple of elevated concentrations of noble gas Xenon-133 were detected at the Takasaki Radionuclide Monitoring Station (JPX38) on 2 October 2017. Xenon-133 is among four relevant radioxenon isotopes that are used for monitoring and verification of nuclear explosions including Xenon-13, Xenon-133m and Xenon-131m. These radioxenon gases could be emitted either from nuclear explosion or civil nuclear facilities including medical isotopes production facilities, nuclear power reactors and nuclear research reactors. This paper presents the Malaysian CTBT National Data Centre (MY-NDC) findings in identifying the possible source regions for elevated concentrations of Xenon-133 detected at JPX38 on 2 October 2017. The findings will be useful in understanding the possible source of release for such Xenon-133 detection, whether coming from a late release of the 3 September 2017 North Korea nuclear test site or from civil nuclear facilities.
The Comprehensive Nuclear-Test-Ban Treaty (CTBT): seismic monitoring
Authors: Zolkaffly M Z , Rashid F I A
Published: July 2019

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is briefly characterized as a global arms control and disarmament initiative, which complements the goal of the Non-Proliferation Treaty (NPT). The verification regime of the CTBT is designed to monitor countries’ compliance with the CTBT by detecting any nuclear explosion conducted on Earth - underground, underwater or in the atmosphere. This paper briefly goes through the International Monitoring System (IMS) of CTBT’s verification regime that uses four different technologies - seismic, hydroacoustic, infrasound and radionuclide - to monitor the planet for nuclear explosions. It pays particular attention to the seismology monitoring techniques of CTBT IMS, including the practical steps in discriminating underground explosions and earthquakes using data mainly from the IMS seismic network. It also highlights the seismic analyses performed by the Malaysian CTBT National Data Centre (MY-NDC) that in principle, applies the practical steps of CTBT nuclear explosion seismology monitoring. In summary underground explosions produced seismic waves with unique characteristics which allowed the discrimination between explosions and earthquakes.
Biochar-coated aluminium electrodes for Cr, Mn and Fe removal in electrochemical treatment for polluted river water remediation
Authors: Mohd Yussuf Nabiha , Embong Zaidi , Mohd Masirin Mohd Idrus , Zainorabidin Adnan , Ahmad Tajudin SaifulAzhar , Mohamed Sunar Norshuhaila , Ahmad Salawati , Maxwell Omeje , Emmanuel Joel
Published: July 2019

Biochar (a by-product of biomass pyrolysis) is developed as a renewable, low-cost, and promising carbon-based electrode for electrochemical remediation of Cr, Mn and Fe in polluted river water. The biochar - electrode were prepared with two types of tailored sieved size medium (2.0 mm) and fine (150 µm). The effect of the different sieved size on the electrochemical reactor was set at 60V of voltage supply, 6 cm inter-electrode distance within 105 minutes electrolysis operational time. The results indicated that the highest removal efficiency for Cr was achieved at 95% after 105 minutes followed by Mn at 99.9% in 65 minutes and Fe at 92.76% in 105 minutes. Interestingly, the electrode with larger sieved size showed the highest removal efficiency for all three elements. These results emphasize the importance of tailoring the porous structure of the biochar electrode material as a function of the specific size of adsorbate ions to improve the electrochemical water treatment performance for polluted river water.
A study on detection water leakage of underground metal and PVC pipes using ground penetrating radar
Authors: Amran T S T , Amin M S M , Ahmad M R , Sani S , Masenwat N A , Bundak C E A , Singoi C J
Published: July 2019

Ground Penetrating Radar (GPR) is a high resolution electromagnetic techniques that is designed primarily to investigate the shallow subsurface of the earth, building material, roads and bridges. GPR was also able to detect water leaks in the underground distribution system. A series of laboratory experiments were conducted to determine the validity and effectives of GPR technology in detecting water leakage using two different types of pipes which are metal and polyvinyl chloride (PVC) pipes. Experiment was conducted using GPR 800 MHz antenna using 4 inch pipe with diameter of hole is ¼ inch to stimulate the leakage. GPR identify leaks in buried water pipes either by detecting underground voids created by the leaking water as it erodes the material around the pipe or by detecting anomalous change in the properties of the materials around pipes due to the water saturation.
Monte Carlo simulation for designing collimator of neutron diffractometer facility in Malaysia
Authors: Ashraff Rosdi Muhammad Aliff , Goh Pei Sean , Shalbi Safwan , Idris Faridah , Jamro Rafhayudi , Isa Norriza Mohd
Published: July 2019

Neutron diffraction (ND) is an application of non-destructive test which involves the process of interference between neutron and atoms within materials. This technique has drawn many attentions especially in industrial, metallurgical and nuclear sectors. Neutron diffractometer system (NDS) is a system which includes all the instrumentation to perform ND technique. One of the most important instruments in NDS set-up is neutron collimator which is used to reduce the size and steer the direction of the beam. Generally, neutron collimator used in NDS is based on step convergent collimator type. Currently, the NDS facility is planned to be built at one of the radial beam port of TRIGA MARK II PUSPATI research reactor (RTP) in Malaysia. The aim of this research is to characterize the materials suitable for neutron collimator and to obtain the ideal geometry for neutron collimator design. In order to achieve these aims, several neutron collimators with different geometries have been designed using Monte Carlo Simulation Codes MCNPX. The results are then compared to obtain the best design with high thermal neutron flux and low gamma contamination at the object plane. This research may be useful in the selection of neutron collimator design for NDS facility at TRIGA research reactor.
Angle resolve x-ray photoelectron spectroscopy analysis of La2O3thin film of mixed carbon-glass and carbon-silicon substrate for micro-flexographic printing process
Authors: Hassan S. , Yusof M.S. , Embong Z.
Published: July 2019

Adhesive property could be described as an interchangeably with some ink and substrate which was applied to one surface of two separate items that bonded together. Lanthanum oxide (La2O3) had been used as a rare earth metal candidate as printing ink. This metal deposit was printed on carbon-silicon substrate and carbon-glass substrate using Magnetron Sputtering technique. The choose of Lanthanum Oxide as a target is due to its wide application in producing micro-electronic devices such as thin film battery, electronic circuit and printed circuit board. The La2O3was deposited on the surface of carbon-silicon and carbon-glass substrate were then analyzed using Angle Resolve X-Ray Photoelectron Spectroscopy (ARXPS). The position for each synthetic component in the narrow scan of Lanthanum (La) 3d and O 1s were referred to the electron binding energy (eV). This research was focused on the narrow scan regions which were O 1s and La 3d. Further discussion of the spectrum evaluation was discussed in detail. Here, it was proposed that from the adhesive and surface chemical properties of La was suitable as an alternative medium for micro-flexographic printing technique in printing multiple fine solid lines image at micro to nano scale feature. Micro-flexographic printing was developed in patterning technique from micron to nano scale range to be used for graphic, electronic and bio-medical device on variable substrates. Hence, this paper will describe the capability of this particular metal as rare earth metal in a practice of micro-flexographic printing process.
Measurement of mass attenuation coefficients of the fabricated Rhizophora spp. particleboards at high energy photons by using Compton scattering method
Authors: Mohd Yusof M F , Abd Hamid P N K , Mohd Isa N , Abd Kadir A B , Salleh H
Published: July 2019

The mass attenuation coefficients of the fabricated Rhizophora spp. particleboards were measured by using the Compton scattering technique and Ludlum configurations. The mass attenuation coefficents of the particleboards were measured at scattered gamma energies of 137Cs between 337.72 and 564.09 keV and compared to the its theoretical values and the values of water by using XCOM calculation. The results showed that the measured mass attenuation coefficients of the fabricated Rhizophora spp. particleboards were in good agreement to its theoretical values and water (XCOM) within 3.8 and 5.9% discrepancies. The results showed the near attenuation properties of the fabricated Rhizophora spp. particleboards to water at scattered gamma energies and the suitability of the Ludlum configuration for the measurement of mass attenuation coefficients of materials.
Using informatics and mobile health to improve medication safety monitoring in kidney transplant recipients
Authors: Taber David J , Pilch Nicole A , McGillicuddy John W , Mardis Caitlin , Treiber Frank , Fleming James N
Published: July 2019

Purpose

The development, testing, and preliminary validation of a technology-enabled, pharmacist-led intervention aimed at improving medication safety and outcomes in kidney transplant recipients are described.

Medication safety issues, encompassing medication errors (MEs), medication nonadherence, and adverse drug events (ADEs), are a predominant cause of poor outcomes after kidney transplantation. However, a limited number of clinical trials assessing the effectiveness of technology in improving medication safety and outcomes in transplant recipients have been conducted. Through an iterative, evidence-based approach, a technology-enabled intervention aimed at improving posttransplant medication safety outcomes was developed, tested, and preliminarily validated. Early acceptability and feasibility results from a prospective, randomized controlled trial assessing the effectiveness of this system are reported here. Of the 120 patients enrolled into the trial at the time of writing, 60 were randomly assigned to receive the intervention. At a mean ± S.D. follow-up of 5.8 ± 4.0 months, there were 2 patient dropouts in the intervention group, resulting in a retention rate of 98%, which was higher than the expected 90% retention rate.

Conclusion

The development and deployment of a comprehensive medication safety monitoring dashboard for kidney transplant recipients is feasible and acceptable to patients in the current healthcare environment. An ongoing randomized controlled clinical trial is assessing whether such a system reduces MEs and ADRs, leading to improved patient outcomes.
Association of luteal cell degeneration and progesterone deficiency with lysosomal storage disorder mucolipidosis type IV in Mcoln1−/− mouse model†
Authors: Wang Zidao , El Zowalaty Ahmed E , Li Yuehuan , Andersen Christian L , Ye Xiaoqin
Published: July 2019

Transient receptor potential cation channel, mucolipin subfamily, member 1 (TRPML1) (MCOLN1/Mcoln1) is a lysosomal counter ion channel. Mutations in MCOLN1 cause mucolipidosis type IV (MLIV), a progressive and severe lysosomal storage disorder with a slow onset. Mcoln1−/− mice recapitulate typical MLIV phenotypes but roles of TRPML1 in female reproduction are unknown. Despite normal mating activities, Mcoln1−/− female mice had reduced fertility at 2 months old and quickly became infertile at 5 months old. Progesterone deficiency was detected on 4.5 days post coitum/gestation day 4.5 (D4.5). Immunohistochemistry revealed TRPML1 expression in luteal cells of wild type corpus luteum (CL). Corpus luteum formation was not impaired in 5–6 months old Mcoln1−/− females indicated by comparable CL numbers in control and Mcoln1−/− ovaries on both D1.5 and D4.5. In the 5–6 months old Mcoln1−/− ovaries, histology revealed less defined corpus luteal cord formation, extensive luteal cell vacuolization and degeneration; immunofluorescence revealed disorganized staining of collagen IV, a basal lamina marker for endothelial cells; Nile Red staining detected lipid droplet accumulation, a typical phenotype of MLIV; immunofluorescence of heat shock protein 60 (HSP60, a mitochondrial marker) and in situ hybridization of steroidogenic acute regulatory protein (StAR, for the rate-limiting step of steroidogenesis) showed reduced expression of HSP60 and StAR, indicating impaired mitochondrial functions. Luteal cell degeneration and impaired mitochondrial functions can both contribute to progesterone deficiency in the Mcoln1−/− mice. This study demonstrates a novel function of TRPML1 in maintaining CL luteal cell integrity and function.
Endometrial luminal epithelial cells sense embryo elongation in the roe deer independent of interferon-tau†
Authors: van der Weijden Vera A , Puntar Brina , Rudolf Vegas Alba , Milojevic Vladimir , Schanzenbach Corina I , Kowalewski Mariusz P , Drews Barbara , Ulbrich Susanne E
Published: July 2019

Numerous intrauterine changes take place across species during embryo development. Following fertilization in July/August, the European roe deer (Capreolus capreolus) embryo undergoes diapause until embryonic elongation in December/January. Embryonic elongation prior to implantation is a common feature among ungulates. Unlike many other ruminants, the roe deer embryo does not secrete interferon-tau (IFNτ). This provides the unique opportunity to unravel IFNτ-independent signaling pathways associated with maternal recognition of pregnancy (MRP). This study aimed at identifying the cell-type–specific endometrial gene expression changes associated with the MRP at the time of embryo elongation that are independent of IFNτ in roe deer. The messenger RNA (mRNA) expression of genes known to be involved in embryo–maternal communication in cattle, pig, sheep, and mice was analyzed in laser capture microdissected (LMD) endometrial luminal, glandular epithelial, as well as stromal cells. The mRNA transcript abundances of the estrogen (ESR1), progesterone receptor (PGR), and IFNτ-stimulated genes were lower in the luminal epithelium in the presence of an elongated embryo compared to diapause. Retinol Binding Protein-4 (RBP4), a key factor involved in placentation, was more abundant in the luminal epithelium in the presence of an elongated embryo. The progesterone receptor localization was visualized by immunohistochemistry, showing an absence in the luminal epithelium and an overall lower abundance with time and thus prolonged progesterone exposure. Our data show a developmental stage-specific mRNA expression pattern in the luminal epithelium, indicating that these cells sense the presence of an elongated embryo in an IFNτ-independent manner.
Why Child Health and Mortality Prevention Surveillance?
Authors: Dowell Scott F , Zaidi Anita , Heaton Penny
Published: July 2019

Recognizing the need for better primary data on the causes of global child mortality, the Bill & Melinda Gates Foundation made an unusually long funding commitment toward a surveillance system using pathology to identify opportunities to prevent child deaths and promote equity.