bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in the range of electric vehicles during operation
Authors: Dobrzycki Arkadiusz , Filipiak Michał , Jajczyk Jarosław
Published: July 2019

This paper describes the trends in growth of the number of electrical vehicles in Europe. The most popular electric cars available on the market were presented, with the capacity of their batteries, energy consumption and range declared by the manufacturer. These data were confronted with the results of road tests. Assuming an average annual mileage, the number of charging cycles was estimated, and on this basis the decrease of battery capacity. The results of calculations were compared with the observations of electric vehicle users. The calculations showed a mileage, after which the user should consider battery packs replacing.
The use of Delfino digital signal controller in power inverter
Authors: Górecki Krzysztof
Published: July 2019

This article analyzes the implementation of control algorithm for a single-phase power inverter using digital signal controller (DSC). For this purpose, a floating-point digital signal controller with a trigonometric math unit was used. The controller’s task was to control the H-bridge through a dedicated driver for power MOSFET transistors. For this task, transistors made in NexFET technology with low channel resistance were used. The H-bridge is the main power device of a single-phase, two-level power inverter powered by a 12V battery. As a modulation method, regular modulation with carrier signal using a triangular signal was used. The main aim was to show the digital signal controller’s performance in real-time control of power inverters and to present the maximum sampling frequency of the inverter that can be obtained for the example having been analyzed.
Project of a universal inverter used to control and supply both AC and DC electric motors
Authors: Ludowicz Wojciech , Danielczyk Dawid , Wojciechowski Rafał M.
Published: July 2019

The paper presents the new approach for motor driver constructions and control systems. Authors of the work proposed the device that can control both AC and DC electric motors without any additional hardware modification. In order to meet this goal the universal motor driver has been constructed and some improvements in output waveform modulation system have been introduced. In the paper the three different method of a motor control have been discussed briefly and a hardware setup has been presented. Tests have been carried out for three types of electric motors, i.e. a magnetoelectric DC motor, single-phase and three-phase induction motor. The obtained results in form of output waveforms of current and voltage have been analyzed in terms of harmonic distortion using a popular Fast Fourier Transform FFT and discussed in the paper.
Analysis and optimization of ultrasonic copper wires using fuzzy logic approach
Authors: Zawadzki Jacek , Jędryczka Cezary
Published: July 2019

Ultrasonic welding has been used in the market over the past thirty years and offer to the manufacturing industries like automotive, aviation, medical and many more due to various hurdles faced by conventional fusion welding or crimp processes. Very short time (less than 1 second) and no additional material during the connection process are very key advantages. Due to this fact this technology can be used for mass production. Plenty of times, the problems faced by industry due to this process are the poor weld quality and strength of the joints surface. In presented study, the process parameters like vibration amplitude, weld pressure and weld time are considered in analysis of the welding of copper wires (Cu- ETP1). Experiment is conducted according to the fractional design with replications to get the responses like tensile shear stress and T-peel stress of the weld. Measured data are utilized next to develop fuzzy logic model between responses and predictors. As a quality is an very important issue in these manufacturing industries, the optimal combinations of studied process parameters are found using fuzzy logic approach.
Didactic means in knowledge and practical skills shaping in the technical education processes
Authors: Bednarek Karol , Bugała Artur , Budzińska Natalia , Wielogórski Mateusz
Published: July 2019

The article deals with the didactic and technical aspects of the information media selection and organization in educational processes in the field of operation and testing the electrical components and systems. The aim was to develop a presentation means that enable the acquisition of practical skills and understanding of the theoretical aspects of the issues under consideration. The practical part presents propositions of original stands for testing and presenting the functioning of rotational speed sensors as well as linear and angular position sensors, used in electrical and IT systems in industry and vehicles. The design, physical implementation and the possibilities of applications were described.
Immunity of photovoltaic installation on electromagnetic surge disturbances
Authors: Bugała Dorota , Bugała Artur , Janczak Damian
Published: July 2019

The work analyzes the correctness of the functioning of the photovoltaic system with a rated electrical power of 3500 W, consisting of 14 photovoltaic modules and a power electronic converter in the form of a single phase voltage inverter equipped with a maximum power point tracking system, disturbed by voltage stroke. The voltage surge with the parameters 1.2/50 µs, simulating a lightning discharge, was introduced into the system from the power grid side. For the purpose of computer simulation performed in Matlab/Simulink, the recommendations included in the PN-EN 61000-4-5 standard "Immunity of the surge disturbances" were used. Significant changes in the voltage and current on the AC side, related to the system of energy return to the power grid were shown.
Non-isolated load sharing direct current system operation with use of the auctioneering diodes
Authors: Kozak Maciej
Published: July 2019

The paper presents the background and results of numerical simulation and experimental research of a system using auctioneering diodes used to distribute the electrical power between two power converters connected with intermediate circuits in parallel, direct connection. Presented non-isolated power distribution system which utilizes blocking diodes placed in DC branches are used in the selected ship's electrical systems, however, they create problems related to control and handling ground faults. Another issue occurring during the operation of this type of systems is increased heat dissipation while diodes switching. Selected problems related to the operation of experimental system have been identified by means of simulation studies and experiments carried out in a 11 kVA laboratory system and the theoretical basis along with results are provided in the article.
The measurement stand with DAQ card for recording a bioelectric signal from human muscles
Authors: Krawiecki Zbigniew , Hulewicz Arkadiusz , Dziarski Krzysztof
Published: July 2019

The measurement stand for recording a bioelectric signal from human muscles has been described in the paper. A DAQ card with a USB bus has been used in the measuring channel. The acquisition of the electromyography signal is carried out using the non-invasive method using gel electrodes. The bioelectric signal is amplified, filtered and processed in hardware and software. The tests of system operation in the measurement laboratory have been carried out. The presented results relate to the measurement of the electromyography signal from the forearm muscles of the upper limb of a human.
The problem of “spectrum leakage” in the measurement of harmonics
Authors: Kuwalek Piotr
Published: July 2019

The paper presents the results of a simulation research showing the problem of "spectrum leakage" in harmonic measurements. At the beginning, the paper discusses issues related to the need to analyze the power quality and the phenomenon of "spectrum leakage". Subsequently, for the test signals, measurement of harmonics in accordance with the applicable standard, was performed. During the simulation research, the frequency of the tested signal was changed in the range of acceptable deviations of the frequency of the voltage in the power grid determined by the appropriate standard. The harmonic measurement error was determined, with the known spectrum of test signals. Metrological interpretation of the obtained results, and formulations of conclusions were presented in the paper.
The prototype of a wireless measurement card
Authors: Jesko Waldemar , Kuwalek Piotr
Published: July 2019

This publication contains the description of the prototype of wireless measurement card that share measurement data via global Internet network. The created measurement card aims to improving the process of obtaining measurement results by enabling remote measurement and sharing results via the Internet. At the beginning of the article, discussed issues are generally presented, which solution is presented device. In the next sections presented the main functional assumptions, describe the most important components included in the prototype and present the algorithm of the main loop of the device program.
Lighting of public spaces at nodal points
Authors: Graczyk Rafał , Nawrowski Artur , Nawrowski Ryszard
Published: July 2019

The publication deals with the issue of lighting public spaces in small towns near the impact of a large urban agglomeration. Indicated the possibility of shaping the illumination of the space based on nodal points. The illumination of a representative example of the city of Lubon located in the Greater Poland was analyzed. The work summarizes the conclusions in the field of lighting and urban problems in the area of shaping public spaces, including nodal points.
Efficiency of public-private co-regulation in the food sector: the French voluntary agreements for nutritional improvements
Authors: Sebillotte Clementina
Published: July 2019

This article analyzes co-regulation as a policy instrument that makes it possible to achieve synergy between public support and private efforts in the food sector to improve the nutritional quality of the food offer. Our objective is to demonstrate the interest and the limits, as well as the conditions of the efficiency of this instrument, through the empirical analysis of the French voluntary agreements for nutritional improvements (charters) implemented in the framework of the French National Nutrition and Health Program (PNNS). We propose an interpretative model of the policy action on the nutritional quality of the food offer set out in the PNNS and we carry out new indicators of success to assess the efficiency of voluntary agreements in the food sector.
On strict sub-Gaussianity, optimal proxy variance and symmetry for bounded random variables
Authors: Arbel Julyan , Marchal Olivier , Nguyen Hien D.
Published: July 2019

We investigate the sub-Gaussian property for almost surely bounded random variables. If sub-Gaussianity per se is de facto ensured by the bounded support of said random variables, then exciting research avenues remain open. Among these questions is how to characterize the optimal sub-Gaussian proxy variance? Another question is how to characterize strict sub-Gaussianity, defined by a proxy variance equal to the (standard) variance? We address the questions in proposing conditions based on the study of functions variations. A particular focus is given to the relationship between strict sub-Gaussianity and symmetry of the distribution. In particular, we demonstrate that symmetry is neither sufficient nor necessary for strict sub-Gaussianity. In contrast, simple necessary conditions on the one hand, and simple sufficient conditions on the other hand, for strict sub-Gaussianity are provided. These results are illustrated via various applications to a number of bounded random variables, including Bernoulli, beta, binomial, Kumaraswamy, triangular, and uniform distributions.
Regularity conditions and Farkas-type results for systems with fractional functions
Authors: Sun Xiangkai , Long Xian-Jun , Tang Liping
Published: July 2019

This paper deals with some new versions of Farkas-type results for a system involving cone convex constraint, a geometrical constraint as well as a fractional function. We first introduce some new notions of regularity conditions in terms of the epigraphs of the conjugate functions. By using these regularity conditions, we obtain some new Farkas-type results for this system using an approach based on the theory of conjugate duality for convex or DC optimization problems. Moreover, we also show that some recently obtained results in the literature can be rediscovered as special cases of our main results.
Ernährung
Authors: Schmid Eva C.
Published: July 2019

In dieser Ausgabe beschäftigen sich alle Prüfungsfragen mit Ernährung.
Allogene Knochenmarktransplantation
Authors: Krome Susanne
Published: July 2019

Die US-amerikanische Food and Drug Administration (FDA) erließ eine Warnung vor Immuncheckpoint-Inhibitoren, wenn sie als Bridging-Therapie vor einer allogenen Knochenmarktransplantation eingesetzt werden. Grund waren Hinweise auf häufigere immunassoziierte Komplikationen nach der Übertragung. Eine aktuelle retrospektive Studie mit 14 transplantierten Patienten bestätigte diese Befürchtung nicht.
Neu diagnostiziertes Ovarialkarzinom
Authors: Krome Susanne
Published: July 2019

Nach einer zytoreduktiven Operation und Chemotherapie erleiden 70 % der Patientinnen mit Ovarialkarzinomen innerhalb von 3 Jahren ein Rezidiv. Der PARP-Inhibitor Olaparib war bei Frauen mit BRCA1/2-Mutation und platinsensitiven Rückfällen eine effektive Erhaltungstherapie. Die SOLO1-Studie belegt die Wirksamkeit von Olaparib nun auch bei neu diagnostizierten Karzinomen.
Akute myeloische Leukämie
Authors: Krome Susanne
Published: July 2019

Die Epigenetik steuert das individuelle genetische Muster durch die Regulation der Genaktivität. Als Angriffspunkte für die Therapie der akuten myeloischen Leukämie waren epigenetische Monotherapien bisher nur begrenzt effektiv. Der Review gibt einen Überblick zu kombinierten Behandlungen und sieht ein Potenzial insbesondere für ältere Erkrankte, bei denen die aggressive Standardtherapie nicht möglich ist.
Desmoidtumoren
Authors: Krome Susanne
Published: July 2019

Desmoide sind benigne Weichteiltumoren, die durch ein aggressives Wachstum, ihre Lokalisation und Rezidivneigung symptomatisch werden können. Neben der chirurgischen Entfernung stehen verschiedene systemische Behandlungen zur Verfügung, einen Standard gibt es nicht. Die Studie belegt die Wirksamkeit des Multikinase-Inhibitors Sorafenib.
Leichtigkeit durch Fünf-Elemente-Ernährung
Authors: Fernkäse Uta
Published: July 2019

Die Fünf-Elemente-Ernährung der TCM ordnet den Elementen - Holz, Feuer, Erde, Metall und Wasser - spezifische Geschmackseigenschaften und Nahrungsmittel zu. Im vorliegenden Fall führte der Lebensstil der Patientin zu Hypertonie, Stress und einer deutlichen Beeinträchtigung der Lebensqualität. Durch Reduktion von Brot, Milch(-Produkten), Kaffee und Süßem sowie einem höheren Anteil an gegartem Gemüse und erwärmten Mahlzeiten in Verbindung mit Bewegung konnte sie wieder Lebensfreude aufbauen und ihre Blutdruckwerte normalisieren.
Zuckerbremse Intervallfasten
Authors: Nebel Gudrun
Published: July 2019

Mit einer rasch wachsenden Zahl von aktuell rund sechs Millionen Betroffenen in Deutschland zählt Diabetes mellitus heute zu den großen Volkskrankheiten und häufigsten Todesursachen. Martin W. zeigte eine bislang unentdeckte, fortgeschrittene Typ-2-Form mit den typischen Ursachen: hochkalorische Ernährung, Übergewicht und Bewegungsmangel. Eine Kombination aus Intervallfasten, Bewegung, Mikronährstoffen und Flohsamen konnte die Zuckerwerte wieder in den Normbereich senken, das Gewicht deutlich reduzieren und die Einnahme von Antidiabetika abwenden.
Verschlingende Leere
Authors: Uta Bammel Psych
Published: July 2019

Betroffene der Binge-Eating-Störung haben regelmäßige Essattacken, bei denen sie nicht selten innerhalb von kurzer Zeit bis zu 10 000 Kalorien zu sich nehmen. Wie bei allen anderen Formen der Essstörung sind meist psychische Konflikte die Ursache, hier häufig begleitet von einem nagenden Gefühl der inneren Leere. Wie das Fallbeispiel demonstriert, sollte die Psychotherapie mit einer Ernährungsberatung kombiniert werden, die Betroffenen hilft, physischen von emotionalem Hunger zu unterscheiden.
Nahrung als Entzündungsmotor
Authors: Koch Simone
Published: July 2019

Autoimmunerkrankungen stehen in engem Zusammenhang mit einer proinflammatorischen Ernährung, unter anderem durch zunehmende Durchlässigkeit des Darms und Aktivierung seines Immunsystems. Alkohol, Gluten, Histamin und Omega-6-Fettsäuren zählen zu den wichtigsten Entzündungstriggern und verursachen neben körperlichen auch psychische Symptome bis hin zu Depression und Angstzuständen. Mit achtwöchiger Restriktionsdiät, gefolgt von einer stufenweisen Wiedereinführung von Nahrungsmitteln können Verursacher identifiziert und bei unklaren immunologischen und psychischen Geschehen überraschende Verbesserungen erzielt werden, wie ein Fallbeispiel verdeutlicht.
Metabolomics in the Diagnosis of Pheochromocytoma and Paraganglioma
Authors: Dwight Trisha , Kim Edward , Novos Talia , Clifton-Bligh Roderick J.
Published: July 2019

Metabolomics refers to the detection and measurement of small molecules (metabolites) within biological systems, and is therefore a powerful tool for identifying dysfunctional cellular physiologies. For pheochromocytomas and paragangliomas (PPGLs), metabolomics has the potential to become a routine addition to histology and genomics for precise diagnostic evaluation. Initial metabolomic studies of ex vivo tumors confirmed, as expected, succinate accumulation in PPGLs associated with pathogenic variants in genes encoding succinate dehydrogenase subunits or their assembly factors (SDHx). Metabolomics has now shown utility in clarifying SDHx variants of uncertain significance, as well as the accurate diagnosis of PPGLs associated with fumarate hydratase (FH), isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH2) and aspartate transaminase (GOT2). The emergence of metabolomics resembles the advent of genetic testing in this field, which began with single-gene discoveries in research laboratories but is now done by standardized massively parallel sequencing (targeted panel/exome/genome testing) in pathology laboratories governed by strict credentialing and governance requirements. In this setting, metabolomics is poised for rapid translation as it can utilize existing infrastructure, namely liquid chromatography-tandem mass spectrometry (LC-MS/MS), for the measurement of catecholamine metabolites. Metabolomics has also proven tractable to in vivo diagnosis of SDH-deficient PPGLs using magnetic resonance spectroscopy (MRS). The future of metabolomics – embedded as a diagnostic tool – will require adoption by pathologists to shepherd development of standardized assays and sample preparation, reference ranges, gold standards, and credentialing.
Synthesis of Phosphaproline Derivatives: A Short Overview
Authors: Gazizov Almir S. , Smolobochkin Andrey V. , Turmanov Rahimjan A. , Pudovik Michail A. , Burilov Alexander R. , Sinyashin Oleg G.
Published: July 2019

Pyrrolidine-based phosphonates, analogues of the natural amino acid proline, possess a diverse set of biological activity. The goal of this short review is to summarize the major developments in the synthesis of phosphaproline derivatives reported since 2004 with special emphasis on the mechanisms and limitations of the methods presented.

1 Introduction

2 Phosphorylation of Pyrrolidine Derivatives

2.1 Syntheses via Pudovik Reaction

2.2 Syntheses via Arbuzov Reaction

2.3 Decarboxylative Phosphorylation of Proline

2.4 Direct C–H Bond Phosphorylation

2.5 Other Reactions

2.6 Overview of Phosphorylation Methods

3 Synthesis of 2-Phosphorylpyrrolidines from Acyclic Precursors

3.1 Cyclization of 4-Substituted Butylamine Derivatives

3.2 [3+2]-Dipolar Cycloaddition of α-Iminophosphonates

3.3 Cyclization of Aminoalkynes and 4-Aminocarbonyl Compounds

4 Conclusions
Synthesis of Acetaminophen Analogues Containing α-Amino Acids and Fatty Acids for Inhibiting Hepatotoxicity
Authors: Jung Seunghee , Kawashima Yuya , Noguchi Takuya , Imai Nobuyuki
Published: July 2019

Acetaminophen is a popular antipyretic analgesic medicine that has weaker anti-inflammatory properties and lower incidence of side effects than nonsteroidal anti-inflammatory drugs (NSAIDs). However, acetaminophen causes hepatotoxicity due to the reactive metabolite N-acetyl-p-benzoquinone imine (NAPQI). We have obtained acetaminophen analogues in 57–99% yields by using aniline derivatives with protected α-amino acids and fatty acids via the corresponding mixed carbonic carboxylic anhydrides in aqueous MeCN. We have also succeeded in synthesizing AM404 analogues in 76–97% yields, which are expected to be promising candidates for reducing hepatotoxicity.
Synthesis of N-Sulfonyl- and N-Acylpyrroles via a Ring-Closing Metathesis/Dehydrogenation Tandem Reaction
Authors: Chen Weiqiang , Zhang Yin-Lin , Li Hui-Jing , Nan Xiang , Liu Ying , Wu Yan-Chao
Published: July 2019

N-Sulfonyl- and N-acylpyrroles were synthesized via olefin ring-closing metathesis of diallylamines and in situ oxidative aromatization in the presence of the ruthenium Grubbs catalyst and a suitable copper catalyst. In the presence of Cu(OTf)2 and CuBr2, the reaction afforded N-sulfonyl- and N-acylpyrroles, respectively, in one pot. Under an oxygen atmosphere, the reaction went smoothly without the need of hydroperoxide oxidants. This protocol possesses many advantages, such as using a nonhazardous oxidant and readily available starting materials, operating in one pot, and showing a broad substrate scope.
Massive Thymic Hyperplasia Mimicking Anterior Mediastinal Neoplasia in Occult Graves' Disease
Authors: Kennedy Christopher James , Paton David James William
Published: July 2019

Background Thymic hyperplasia is a recognized complication of Graves' disease that can present radiologically as an anterior mediastinal mass.

Case Description We present a unique case of massive thymic hyperplasia occurring in a 24-year-old female without a known history of thyroid or other systemic disease in whom Graves' disease first manifested intraoperatively during thymectomy for presumed neoplasia.

Conclusion We suggest that the work-up of all anterior mediastinal masses should include a comprehensive search for medical causes of reversible thymic enlargement.
Effect of Injectable Platelet-Rich Fibrin on Diced Cartilage's Viability in Rhinoplasty
Authors: Gode Sercan , Ozturk Arin , Berber Veysel , Kısmalı Erkan
Published: July 2019

Diced cartilage is one of the most widely used camouflage technique in rhinoplasty. Its variable resorption rate creates issues in postoperative time period. Platelet-rich fibrin is an autologous concentrated blood derivative containing growth factors that accelerate tissue healing. The authors evaluate the effect of injectable platelet-rich fibrin (I-PRF) on the viability of diced cartilage, which has been used for dorsum camouflage in rhinoplasty. Forty patients were randomly divided into two groups based on dorsal camouflage grafts: diced cartilage with I-PRF (study group) and diced cartilage without I-PRF (control group). Cartilage graft thickness was measured by linear superficial tissue ultrasound at the postoperative first week and the third month in both groups. The mean cartilage graft thickness loss between the first-week and third-month ultrasound measurements was 0.58 ± 0.21 mm in the study group and 0.82 ± 0.35 mm in the control group. There was significant volume loss in the control group. I-PRF was successful in reducing the resorption rate of diced cartilage on nasal dorsum by either increasing the viability or keeping its form. Sticky cartilage is an easily applicable and reliable technique that may be used to camouflage dorsal irregularities in rhinoplasty.
The Effect of Platelet-Rich Fibrin on Nasal Skin Thickness in Rhinoplasty
Authors: Gode Sercan , Ozturk Arin , Kısmalı Erkan , Berber Veysel , Turhal Goksel
Published: July 2019

The study hypothesized the potential positive effects of platelet-rich fibrin (PRF) in postoperative rhinoplasty patients, such as better wound healing, less dead space, and less edema. The authors assessed PRF for nasal dorsum camouflage and studied its potential effects on nasal dorsal skin in rhinoplasty. Thirty-eight patients who underwent open approach primary rhinoplasty were categorized into two groups: nasal dorsal PRF group and control group. PRF membrane was used for nasal dorsum camouflage and laid over the bony dorsum and cartilage framework of the supratip area. Skin and subcutaneous soft tissue thickness were measured by linear superficial tissue ultrasound at the pre- and postoperative first week and the third month in both groups. Mean skin thickness over the supratip area was significantly higher in the control group in the first-week control. There were no significant differences in both first-week and third-month controls' nasal dorsum mean skin thickness measurements between the two groups. Regarding PRF complications, we encountered no complications in either group, including scarring, hematoma, infection, skin discoloration, and acne. The authors present the application of PRF membrane over the bony dorsum and cartilage framework of the supratip area. They observed its positive effect on postoperative edema, especially in the early postoperative period. Long-term investigations have to be performed to evaluate its potential effect on the rhinoplasty procedure. This was a level of evidence 3 study.
First-principle investigation of the charge injection barriers of polyethylene and polytetrafluoroethylene oligomers
Authors: Chen Xi , Zhao Aixuan , Li Jiaming , Deng Junbo , Zhang Guanjun , Zhao Xuefeng
Published: July 2019

Experimental research has shown that much less charge injection occurs in polytetrafluoroethylene (PTFE) compared to polyethylene (PE). To clarify the mechanisms of charge injection from metals into polymer insulators, we comparatively studied charge injection in PE and PTFE oligomers using first-principles calculations. Two different models were studied: chemisorption (bonding) and physisorption (nonbonding). The results show that the electron injection barrier of the metal/PTFE interface is larger than that of the metal/PE interface only in the case of chemisorption. The larger electron injection barrier of the metal/PTFE oligomer interface is mainly affected by the positive vacuum level shift of the metal/PTFE interface induced by electron transfer from the metal to PTFE along the chemical bonds. In the case of physisorption, the hole injection barrier of the metal/PTFE interface is larger than that of the metal/PE interface. This is attributed to the larger ionization potential of PTFE compared to PE. The calculated results reasonably explain the experimental phenomena. The agreement between the experimental and calculated results verifies the rationality of our calculation models. The models used herein can likely be applied in other metal/polymer interfacial systems with acceptable accuracy.
High performance In0.83Ga0.17As SWIR photodiode passivated by Al2O3/SiNx stacks with low-stress SiNx films
Authors: Wan Luhong , Cao Gaoqi , Shao Xiumei , Deng Shuangyan , Cheng Jifeng , Gu Yi , Li Xue
Published: July 2019

To develop extended InGaAs photodiode focal plane arrays with large scale and small pixels, a surface passivation film with low stress is necessary. To study the surface bowing of SiNx passivation film deposited with different conditions by inductively coupled plasma chemical vapor deposition, 2-in. InP samples were first utilized to obtain statistical results. As can be seen from the result, the bowing introduced by the passivation film is reduced to less than 10 μm when applying optimized film deposition conditions, which is a significant optimization. In the further investigation of the passivation effect on the InGaAs photodiode, Al2O3/SiNx stacks were proposed as the passivation layer, and Al2O3 was deposited by atomic layer deposition (ALD). Results demonstrate that the photodiodes passivated by the Al2O3/SiNx stacks have lower dark current density, especially at lower temperatures. At 180 K, the contribution of perimeter dark current is reduced by more than one order of magnitude. Theoretical analysis shows that the composite passivation film effectively suppresses tunneling current at 180 K.
Multiplexed readout of kinetic inductance bolometer arrays
Authors: Sipola Hannu , Luomahaara Juho , Timofeev Andrey , Grönberg Leif , Rautiainen Anssi , Luukanen Arttu , Hassel Juha
Published: July 2019

Kinetic inductance bolometer technology is a candidate for passive submillimeter wave and terahertz imaging systems. Its benefits include scalability into large 2D arrays and operation with intermediate cryogenics in the temperature range of 5–10 K. We have previously demonstrated the scalability in terms of device fabrication, optics integration, and cryogenics. In this article, we address the last missing ingredient, the readout. The concept, serial addressed frequency excitation, is an alternative to full frequency-division multiplexing at microwave frequencies conventionally used to read out kinetic inductance detectors. We introduce the concept and analyze the criteria of the multiplexed readout avoiding the degradation of the signal-to-noise ratio in the presence of a thermal anti-alias filter inherent to thermal detectors. We present a practical scalable realization of a readout system integrated into a prototype imager with 8712 detectors. This is used for demonstrating the noise properties of the readout. Furthermore, we present practical detection experiments with a stand-off laboratory-scale imager.
Effects of non-pairwise repulsion on nanoparticle assembly
Authors: Hopkins Sawyer S. , Chakrabarti Amitabha , Schmit Jeremy D.
Published: July 2019

Electrostatic interactions provide a convenient way to modulate interactions between nanoparticles, colloids, and biomolecules because they can be adjusted by the solution pH or salt concentration. While the presence of salt provides an easy method to control the net interparticle interaction, the nonlinearities arising from electrostatic screening make it difficult to quantify the strength of the interaction. In particular, when charged particles assemble into clusters or aggregates, nonlinear effects render the interactions strongly non-pairwise. Here, we report Brownian dynamics simulations to investigate the effect that the non-pairwise nature of electrostatic interactions has on nanoparticle assembly. We compare these simulations to a system in which the electrostatics are modeled by a strictly pairwise Yukawa potential. We find that both systems show a narrow range in parameter space where the particles form well-ordered crystals. Bordering this range are regions where the net interactions are too weak to stabilize aggregated structures or strong enough that the system becomes kinetically trapped in a gel. The non-pairwise potential differs from the pairwise system in the appearance of an amorphous state for strongly charged particles. This state appears because the many-body electrostatic interactions limit the maximum density achievable in an assembly.
Five gaseous reactive oxygen and nitrogen species (RONS) density generated by microwave plasma jet
Authors: Zhao Jingcheng , Nie Lanlan
Published: July 2019

Microwave plasma jets based on a coaxial transmission line resonator show outstanding advantages such as portability, lower power consumption, and low-temperature operation. In this manuscript, the most important of the five gaseous reactive oxygen and nitrogen species (RONS) densities including OH, O, O3, NO, and NO2 densities are measured synchronously, while the plasma jet is treating a biological tissue under different discharge parameters (gas composition, gas flow, skin humidity, and output power). It has been found that the gas composition and the output power are two key factors to regulate the dose of RONS concentrations. For the OH concentration, water vapor in the gas flow plays an important role. By changing the microwave power and the gas composition, the OH concentration changes from 0.4 × 1014 cm−3 to 5.54 × 1014 cm−3. O is mostly affected by the O2 percentage in Ar, and 1% percentage is the optimal value. O3 is proportional to the O2 percentage in Ar, and 2% O2 can get a maximum O3 density of 6.9 × 1016 cm−3. NO is in the range of 2 × 1013 cm−3 to 5.4 × 1014 cm−3, and NO2 is in the range of 5.5 × 1014 cm−3 to 5 × 1015 cm−3. The increase in the humidity of the skin has a positive effect on the concentration of OH, O3, and NO while a negative effect on the O and NO2 concentration. For the normal skin with a humidity of 40%, the concentrations of the long lifetime species like O3 and NO2 are almost 101–2 times those of the other reactive species. This research provides parameter setting guidance for different RONS requirements.
Integrated photonics for low transverse emittance, ultrafast negative electron affinity GaAs photoemitters
Authors: Blankemeier L. , Rezaeifar F. , Garg A. , Kapadia R.
Published: July 2019

Photocathodes exhibiting simultaneous high quantum efficiency, low mean transverse energy (MTE), and fast temporal response are critical for next generation electron sources. Currently, caesiated negative electron affinity GaAs photocathodes have demonstrated good overall results [Bell and Spicer, Proc. IEEE 58, 1788 (1970); Pierce et al., Appl. Phys. Lett. 26, 670 (1975)]. However, due to the nature of the photoemission process and the details of the Cs surface structure, a tradeoff exists. A low mean transverse energy of ∼25 meV can be obtained by using photons with near bandgap energy, at the cost of an unacceptably high response time, or higher energy photons can be used with a mean transverse energy of ∼60 meV with acceptable response times of 2–5 ps [Karkare et al., J. Appl. Phys. 113, 104904 (2013); Honda et al., Jpn. J. Appl. Phys. 52, 086401 (2013); Pastuszka et al. Appl. Phys. Lett. 71, 2967 (1997)]. Here, it is shown through a calibrated simulation that a thin layer of caesiated GaAs on a waveguide can potentially exhibit photoemission with MTEs ∼30 meV, ultrafast response times of ∼0.2–1 ps, and quantum efficiency of 1%–10%, breaking the traditional tradeoffs associated with bulk negative electron affinity photoemitters.
A scintillator-based soft X-ray streak camera system for Z-pinch experiments on the Primary Test Stand
Authors: Zhou Shaotong , Xie Weiping , Huang Xianbin , Ren Xiaodong , Wang Kunlun , Xu Qiang
Published: July 2019

A soft x-ray streak camera system based on the conversion of fast scintillator has been developed to diagnose 10-MA Z-pinch implosions on the Primary Test Stand facility. The streak camera system is used to measure the continuous time history of the 0.2–10 keV x-ray emission from pinch plasmas and proved to be free from the intense electromagnetic environment effectively during the discharge of the Primary Test Stand. The spatial resolution of the streak camera system is estimated to be less than 120 μm, and its temporal resolution has been calibrated to be about 1 ns. X-ray streak images of aluminum wire-array plasmas have been obtained successfully in experiments, and the nonuniformity of the x-ray emission along the axial direction has been observed.
Instability-enhanced transport in low temperature magnetized plasma
Authors: Lucken R. , Bourdon A. , Lieberman M. A. , Chabert P.
Published: July 2019

It is shown that the transport in low temperature, collisional, bound plasma is enhanced by instabilities at a high magnetic field. While the magnetic field confines the electrons in a stable plasma, the instability completely destroys the confinement such that the transport becomes independent of the magnetic field in the highly magnetized limit. An analytical expression of the instability-enhanced collision frequency is proposed, based on a magnetic field independent edge-to-center density ratio.
Facility for calibration of optical and condensation particle counters based on a turbulent aerosol mixing tube and a reference optical particle counter
Authors: Horender Stefan , Auderset Kevin , Vasilatou Konstantina
Published: July 2019

In this study, we present a custom-made facility developed for evaluating the measurement efficiency of optical particle counters and other common aerosol instrumentation. The facility consists of an aerosol generation setup, a turbulent flow tube for particle homogenization, isokinetic sampling ports, and a home-built particle counter that serves as a reference instrument. Stable and reproducible aerosols of polystyrene latex particles can be produced in the size range 100 nm–10 μm and at concentrations between 0.5 cm−3 and a few thousand submicron particles per cm3 or a few tens of 10 µm particles per cm3. The flow characteristics in the homogenizer were investigated with laser Doppler velocimetry measurements and computational fluid dynamics simulations indicating a plug (turbulent) flow at the aerosol sampling location. The particle mixing characteristics were determined experimentally at various heights of the flow tube by parallel measurements with two condensation particle counters. A spatial homogeneity within 1.1% was found across the sampling area. The measurement uncertainties in the determination of the particle number concentration have been evaluated in detail and amount typically to 5.4% at 1 cm−3 and 2.1% at 100 cm−3 (95% confidence level).
Finite-sample bias in free energy bridge estimators
Authors: Radak Brian K.
Published: July 2019

In practical free energy estimation, the bias is often neglected once it has been shown to vanish in the large-sample limit. Yet finite-sample bias always exists and ought to be considered in any rigorous study. This work develops a metric for bias in a broad class of free energy “bridge estimators” (e.g., Bennett’s method). The framework complements existing variance estimation methods and provides a means for comparing systematic and statistical errors. Examples show that, contrary to what is often assumed, the bias can be quite substantial when the sample size is modest.
Ferroelectricity in YO1.5-HfO2 films around 1 μm in thickness
Authors: Mimura Takanori , Shimizu Takao , Funakubo Hiroshi
Published: July 2019

Ferroelectricity has been demonstrated in polycrystalline 7%Y-doped HfO2 (YHO7) films with thicknesses ranging from 10 to 930 nm, which were grown on (111)Pt/TiOx/SiO2/(001)Si substrates by pulsed laser deposition at room temperature and subsequent annealing at 1000 °C. The X-ray diffraction pattern suggested that the major crystal phase consists of orthorhombic/tetragonal phases with a small amount of monoclinic phase even for the 930-nm-thick film despite its thickness. Moreover, the hysteresis loops associated with the ferroelectric orthorhombic phase were clearly observed for all samples including even the 930-nm-thick film. The remnant polarization (Pr) and the coercive field (Ec) are 14–17 μC/cm2 and 1300–1600 kV/cm, respectively, at max applied electric fields of ∼4000 kV/cm for all YHO7 films within the present study. These results indicate that the ferroelectric structure and properties of YHO7 films are insensitive to the film thickness.
Observation of charge density wave transition in TaSe3 mesowires
Authors: Yang J. , Wang Y. Q. , Zhang R. R. , Ma L. , Liu W. , Qu Z. , Zhang L. , Zhang S. L. , Tong W. , Pi L. , Zhu W. K. , Zhang C. J.
Published: July 2019

Quasi-one-dimensional (quasi-1D) TaSe3 is attracting considerable attention due to its intriguing superconductivity and possible interplay with nontrivial topology and the charge density wave (CDW) state. However, unlike the isostructural analogs, CDW has not been observed for TaSe3 despite its quasi-1D character that is supposed to promote Peierls instabilities and CDW. Here, we synthesize TaSe3 mesowires (MWs) using a one-step approach. For the MW of ∼300 nm thickness, a distinct CDW transition occurs at 65 K in the resistivity measurement, which is further evidenced by the Raman characterization and the susceptibility measurement. For comparison, we have also prepared bulk single crystal TaSe3. Although no anomaly appears in the resistivity and magnetoresistance measurements, the carrier type detected by the Hall effect varies from n-type to p-type below 50 K, suggesting a reconstruction of the Fermi surface that could be associated with CDW. The enhancement of CDW in the MWs is attributed to the reduced dimensionality. TaSe3 is demonstrated to be a promising platform to study the correlation and competition of CDW and superconductivity in the quasi-1D systems.
The electromagnetic ion cyclotron instabilities of a plasma with parallel sheared current
Authors: Mikhailenko V. V. , Mikhailenko V. S. , Lee H. J.
Published: July 2019

The electromagnetic (EM) ion cyclotron (IC) instability of a plasma with parallel sheared current is investigated analytically with numerical solutions. This instability is the electromagnetic counterpart of the electrostatic current-driven ion cyclotron instability, which is renowned as the Drummond-Rosenbluth (DR) instability. Considered is the case with the current velocity shearing rate less than the ion cyclotron frequency, which corresponds to the tokamak and space plasmas. We found two new EM DR instabilities: the modified EM DR instability by the current shear and the subcritical EM DR instability which develops above the upper and below the lower critical velocities of the EM DR instability driven by the uniform current, respectively. The modified EM DR instability by the current shear develops due to the inverse electron Landau damping, whereas the subcritical EM DR instability develops due to the coupled effect of the IC damping and the current shear jointly with the inverse electron Landau damping. We also found the shear-flow-driven EM IC instability of the current-free sheared flow which develops by virtue of the coupled action of the IC damping and flow velocity shear.
A customized instrument with laser interferometry for measuring electrospun mat thickness
Authors: Zhou Jianyu , Roberts O. Steven , Goldwasser Samuel M. , Lei Xia , Bokka Sreevalli , Chase George G.
Published: July 2019

Thickness is an important characteristic parameter of electrospun submicron of fiber mats and membranes. The thickness of the mats directly influences performance properties such as permeability and is necessary when determining volumetric parameters such as porosity. Typical electrospun mats are very thin (less than 1 mm) and highly compressive due to the small diameter fibers, both of which make accurate measurements difficult when using conventional methods. An accurate measure of the thickness is desired for characterizing and comparing membrane performances. In this work, a thickness measurement instrument using laser interferometry has been designed to measure electrospun fiber mat thickness. A small disk is used to apply a small (reproducible) force applied across a reasonably small area of the fiber mat. A traversing pin moves to contact the disk and completes an electrical circuit to stop movement and determine the location of the disk relative to a reference plane. The fiber mat thickness is determined by measuring the difference in locations of the disk with and without the fiber mat between the disk and the reference plane. The prototype is simple to operate and user-friendly. Precision and accuracy of the prototype are discussed.
Influence of antiphase and ferroelastic domain boundaries on ferromagnetic domain wall width in multiferroic Ni-Mn-Ga compound
Authors: Vronka Marek , Heczko Oleg , De Graef Marc
Published: July 2019

This paper reports on the experimental measurements of magnetic domain wall (DW) widths by Lorentz transmission electron microscopy in Ni-Mn-Ga ferromagnetic shape memory alloys. The wall widths were measured and compared in both austenitic and martensitic states, at positions pinned on antiphase boundaries (APB) or coinciding with the twin boundaries (TB) together with walls at APB-free and TB-free positions. The thickest DW widths of about 28 nm were measured in APB-free positions in austenite. DW in APB-free and TB-free positions in martensite had widths of about 10 nm for in-plane and 13 nm for perpendicular easy axis orientation. The narrowest DWs with widths about 7–8 nm were measured for walls pinned on APBs in austenite or for walls coinciding with the TBs in martensite. The measurements are broadly in agreement with theoretical wall width predictions in thin foil.
Unveiling diffusive states from center-of-mass trajectories in glassy dynamics
Authors: Hachiya Yuto , Uneyama Takashi , Kaneko Toshihiro , Akimoto Takuma
Published: July 2019

We propose a method to detect alternating diffusive states undergoing a free diffusive state and a trapped state described by the Ornstein-Uhlenbeck process. Using a stochastic model with alternating diffusive states, a phenomenological model of glassy dynamics, we show that control parameters in the method may be determined by the mean square displacement and the non-Gaussianity parameter. Our method works when diffusivities for the two states are clearly distinct and all the states last longer than a specified relaxation time. Applying our method to molecular dynamics simulation data of supercooled liquids, we show that trapped states last for a long time and the sojourn-time distribution for trapped states becomes a power-law form as the temperature approaches the glass temperature.
Generating the conformational properties of a polymer by the restricted Boltzmann machine
Authors: Yu Wancheng , Liu Yuan , Chen Yuguo , Jiang Ying , Chen Jeff Z. Y.
Published: July 2019

In polymer theory, computer-generated polymer configurations, by either Monte Carlo simulations or molecular dynamics simulations, help us to establish the fundamental understanding of the conformational properties of polymers. Here, we introduce a different method, exploiting the properties of a machine-learning algorithm, the restricted Boltzmann machine network, to generate independent polymer configurations for self-avoiding walks (SAWs), for studying the conformational properties of polymers. We show that with adequate training data and network size, this method can capture the underlying polymer physics simply from learning the statistics in the training data without explicit information on the physical model itself. We critically examine how the trained Boltzmann machine can generate independent configurations that are not in the original training data set of SAWs.
Orientational relaxation of a quantum linear rotor in a dissipative environment: Simulations with the hierarchical equations-of-motion method
Authors: Chen Lipeng , Gelin Maxim F. , Domcke Wolfgang
Published: July 2019

We study the effect of a dissipative environment on the orientational relaxation of a three-dimensional quantum linear rotor. We provide a derivation of the Hamiltonian of a linear rotor coupled to a harmonic bath from first principles, confirming earlier conjectures. The dynamics generated by this Hamiltonian is investigated by the hierarchical equations-of-motion method assuming a Drude spectral density of the bath. We perform numerically accurate simulations and analyze the behavior of orientational correlation functions and the rotational structures of infrared absorption and Raman scattering spectra. We explore the features of orientational correlation functions and their spectra for a wide range of system-bath couplings, bath memory times, and temperatures. We discuss the signatures of the orientational relaxation in the underdamped regime, the strongly damped regime, and the librational regime. We show that the behavior of orientational correlation functions and their spectra can conveniently be analyzed in terms of three characteristic times, which are explicitly expressed in terms of the parameters of the Hamiltonian.