bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electron–neutral bremsstrahlung radiation fingerprints the initial stage of nanosecond discharge in liquid water
Authors: Bílek Petr , Tungli Ján , Hoder Tomáš , Šimek Milan , Bonaventura Zdeněk 
Published: March 2021

Abstract
We postulate that basic radiative signatures observed during the initial phases of nanosecond discharge in liquid water can be attributed to the electron–neutral bremsstrahlung process. Principal characteristics of the radiation collected from developing luminous filaments consist of a sharp decrease in the emission intensity at the short-wavelength side of the spectra, followed by a maximum and subsequent decrease in intensity towards near-infrared wavelengths. All these radiative features can be attributed to the electron–neutral bremsstrahlung produced by a bell-like energy distribution of the electrons. Such an electron energy distribution function is coherent with the concept of electric field emission into electrostriction-induced nanovoids. The findings of this work help in elucidating the hitherto unclear mechanism(s) of plasma generation in liquid water.
Obtaining the unperturbed plasma potential in low-density, low-temperature plasmas
Authors: Causa Federica , Gervasini Gabriele , Uccello Andrea , Granucci Gustavo , Ricci Daria , Rispoli Natale 
Published: March 2021

Abstract
A method is proposed to effectively obtain plasma parameters in low-density, low-temperature plasmas that are easily perturbed by Langmuir probes. The methodology is based on the perimeter sheath expansion method because it provides a simple, but effective interpretation of the Langmuir probe characteristics and, in particular, of the non-saturating trend of the ion saturation due to the expansion of the probe sheath. However, the perimeter sheath expansion method is proposed here in a modified version with a dual purpose: to permit the verification of the Child–Langmuir dependence of the sheath thickness from the potential and, most importantly, to properly assess the plasma potential. When probe perturbation is significant the proposed method provides an effective correction term for the plasma potential. The resulting sheath voltage is consistent in all analysed cases and in close agreement with the expected value for cylindrical probes in Ar. The method is applied to Ar plasmas here, but because no specific assumption was made on the atomic species, it may be applicable to other situations of interest.
Electron power absorption in radio frequency driven capacitively coupled chlorine discharge
Authors: Proto A , Gudmundsson J T 
Published: March 2021

Abstract
Particle-in-cell Monte Carlo collision simulations and Boltzmann term analysis are applied to study the origination and properties of the electric field and the electron power absorption within the electronegative core of a capacitively coupled discharge in chlorine as the pressure is varied from 1 to 50 Pa. The capacitively coupled chlorine discharge exhibits high electronegativity and high electric field develops within the electronegative core. It is found that the electron power absorption increases and the ion power absorption decreases as the pressure is increased. At 1 Pa the electron power absorption is due to both the pressure and ohmic terms. At the higher pressures >10 Pa the ohmic term dominates and all the other contributions to the electron power absorption become negligible. Therefore, the discharge becomes increasingly ohmic with increased pressure and eventually behaves as a resistive load.
Analysis of temperature dependent dark current mechanisms for long-wavelength infrared p-on-n HgCdTe detectors
Authors: Li Xun , Wang Xi , Lin Chun , Wei Yanfeng , Zhou Songmin , Sun Quanzhi 
Published: March 2021

Abstract
The dark current density versus voltage (J–V) curve of long-wavelength infrared (LWIR) p-on-n mercury cadmium telluride (HgCdTe, MCT) photodiode is measured in the temperature range of 40 K–130 K in this study. The dark current mechanisms, namely diffusion, generation–recombination (GR), trap-assisted tunneling, band-to-band tunneling (BBT) and shunt current, are investigated for LWIR p-on-n MCT diode at different temperatures. The results show that the dark current is dominated by diffusion current at low reverse bias when the operating temperature is above 65 K. As the operating temperature decreases, GR current and shunt current gradually become the main ingredient of dark current. In the high reverse bias region, the contribution of BBT mechanism accounts for the largest proportion when the operating temperature is below 75 K. The extracted fitting parameters show that the donor concentration in the n-type region of p-on-n MCT diode display better temperature stability compared with that of n-on-p diodes. Because the thermal excitation effect increases with the increase of temperature, the equivalent trap level moves from shallow acceptor level to deep acceptor level, and the trap density increases from 1.1 × 1010 to 6.0 × 1012 cm−3 when the operating temperature is increased from 80 K to 130 K.
Liquid vaporization actuated soft structures with active cooling and heat loss control
Authors: Lee Han-Joo , Loh Kenneth J 
Published: March 2021

Abstract
Soft robotic systems that are inspired by nature utilize soft materials to perform various tasks in diverse environments. One promising method to control their movement is by utilizing liquid vaporization. In most cases, liquid with high vapor pressure is injected into hollow cavities inside the elastomer. Heating the system vaporizes the liquid, and the structure is inflated by the generated gas. However, there is a significant time lag between powering the system and structural actuation due to the slow increase in temperature that is exacerbated by heat loss. Simply using materials with low thermal conductivity can improve actuation, but the reduced heat loss concurrently increases cooling time during the reversing process. Furthermore, underwater actuation through vaporization remains a challenge, since heat loss becomes even more significant. To address these issues, this study aims to develop a system that can actively control heat loss to enhance both actuation and cooling while performing consistently even in extreme environments. First, double-walled structures were fabricated with silicone elastomer to drastically lower thermal conductivity. Next, a thermoelectric device was installed on the bottom layer to heat and cool the sealed liquid by reversing current flow. The low thermal conductivity of the double-walled structure enhanced actuation performance, while actively cooling the system with the thermoelectric device accelerated the reversing process. Structures with single- and double-layered walls were tested underwater to validate their performance. Finite element models verified the effects of wall designs on heat transfer and structural mechanics. Demonstration of enhanced reversible actuation of the system was performed using a soft anemone-like structure operated underwater.
An ultrawide-zero-frequency bandgap metamaterial with negative moment of inertia and stiffness
Authors: Yang Leiyu , Wang Lifeng 
Published: March 2021

Abstract
Metamaterials have demonstrated great potential for controlling wave propagation since they are flexibly adjustable. A new one-dimensional metamaterial model with both a negative effective moment of inertia and negative effective stiffness is proposed. A negative effective moment of inertia and negative effective stiffness can be achieved by adjusting the structural parameters in certain frequency ranges. Bandgaps in the low-frequency range with exponential wave attenuation can be generated in the metamaterial. A flat band is obtained that couples two Bragg bandgaps to achieve a wide bandgap in the low-frequency range, where the effective moment of inertia and effective stiffness are both infinite. A zero-frequency bandgap can be achieved by adjusting the structural parameters. Quick attenuation of wave is observed in the zero-frequency ranges with single-negative parameters. Furthermore, an ultrawide-zero-frequency bandgap is obtained by optimizing the structural parameters of the system. In addition, it is easy to switch between the Bragg and locally resonant bandgaps. This new metamaterial can be applied to ultralow-frequency-vibration isolation.
Modified MIT bag Models—part I: Thermodynamic consistency, stability windows and symmetry group
Authors: Lopes Luiz L , Biesdorf Carline , Menezes Débora P 
Published: March 2021

Abstract
In this work we study different variations of the MIT bag model. We start with the so called non-ideal bag model and discuss it in detail. Then we implement a vector interaction in the MIT bag model that simulates a meson exchange interaction and fix the quark-meson coupling constants via symmetry group theory. At the end we propose an original model, inspired by the Boguta-Bodmer models, which allows us to control the repulsion interaction at high densities. For each version of the model we obtain a stability window as predicted by the Bodmer-Witten conjecture and discuss its thermodynamic consistency.
Corrosion behavior of aluminum-Fiber Glass composite fabricated through surface mechanical alloying in alkaline media
Authors: Shehata O S , Mohamed Ebrahim Mohamed Refaat , Abdel Fatah Amr H 
Published: March 2021

AbstractDissolution reaction control of aluminum in 2M KOH alkaline media was achieved through surface mechanical alloying SMA with dielectric Fiber glass ‘FG’ powder. A significant decrease corrosion rate from 0.867 for blank Al to 0.0002 mm y−1for SMA Al with FG powder previously etched after 15 min; surface mechanical attrition treatment ‘SMAT’; Formed surface metal matrix Al/FG composites layers on Al anodes have attractive electrical properties. Its analysis obtained using X-Rays Diffraction XRD, scanning electron microscopy SEM. Used three electrochemical techniques EIS, CV and PDP indicate corrosion resistance improvement in 2M KOH correspond to inhibition efficiency reaches 99.81%. Such inhibition encourage for forming efficient and safe air batteries for interesting applications using Al anodes after consecutive SMAT & SMA processing.
Multiple adjustable Fano resonance based on double half ring resonator and its application
Authors: He Qian , Huo Yiping , Guo Yiyuan , Niu Qiqiang , Hao Xiangxiang , Cui Pengfei , Wang Yunyan , Song Meina 
Published: March 2021

Abstract
In this paper, a compact nanostructure is proposed that includes a metal insulator metal (MIM) waveguide with a metal wall and a side-coupled half-ring resonator. The transmission characteristics of the system are studied numerically by using the finite element method (FEM). The simulation results show that double Fano resonances can be produced in the structure, and the two Fano resonances can be controlled independently by two different half rings. The position and intensity of the Fano resonance peaks can be adjusted flexibly and easily by changing the refractive index of the filling medium. The waveguide is sensitive to the refractive index of the filling medium inside the resonator and the maximum sensitivity and figure of merit (FOM) are 1260 nm/RIU and 26,000 respectively. By adding two more half-rings below, four independently adjustable Fano resonances are obtained. The structure of this paper can be used as a sensor which can detect the glucose concentration, so it has a broad application prospect in biomedical and chemical sensing fields.
Cosmological bubble friction in local equilibrium
Authors: Balaji Shyam , Spannowsky Michael , Tamarit Carlos 
Published: March 2021

Abstract
In first-order cosmological phase transitions, the
asymptotic velocity of expanding bubbles is of crucial relevance for
predicting observables like the spectrum of stochastic gravitational
waves, or for establishing the viability of mechanisms explaining
fundamental properties of the universe such as the observed baryon
asymmetry. In these dynamic phase transitions, it is generally
accepted that subluminal bubble expansion requires
out-of-equilibrium interactions with the plasma which are captured
by friction terms in the equations of motion for the scalar
field. This has been disputed in works pointing out subluminal
velocities in local equilibrium arising either from hydrodynamic
effects in deflagrations or from the entropy change across the
bubble wall in general situations. We argue that both effects are
related and can be understood from the conservation of the entropy
of the degrees of freedom in local equilibrium, leading to
subluminal speeds for both deflagrations and detonations. The
friction effect arises from the background field dependence of the
entropy density in the plasma, and can be accounted for by simply
imposing local conservation of stress-energy and including field
dependent thermal contributions to the effective potential. We
illustrate this with explicit calculations of dynamic and static
bubbles for a first-order electroweak transition in a Standard Model
extension with additional scalar fields.
Cascading attack on trusted-relay quantum key distribution networks
Authors: Wang Jian , Liu Xing-tong 
Published: March 2021

Abstract
Trusted relays are the main state-of-the-art way to realize quantum key distribution networks. However, it is hard to require that all nodes in the network are fully trusted. In a multipath key-transmission mechanism, the nodes can be weakly trusted because the secret key can be split into many parts and each part is transmitted to the receiver through a different path. However, if the capacity of a node’s quantum key pool is poorly designed, an attacker, Eve may eavesdrop on the communicating parties’ secret message by initiating a redirection attack. In this paper, we show that Eve can trigger a cascading collapse effect by collapsing one of the edges in the network and forcing the communication parties to transmit the message through the nodes controlled by Eve. The influence of the traffic transfer ratio and the control parameters of the edge load on the breakdown probability of the edge are analyzed using a simulation. In order to effectively defend against the cascading attack, it is important for the designer to handle the relationship between the traffic and the capacity of the quantum key pool of each node in the network.
Numerical and Experimental Analysis in the Production of a Solar Still
Authors: Chávez S , Terres H , Lizardi A , López R , Lara A , Vaca M 
Published: March 2021

Abstract
In this work, a numerical and experimental study is shown for a single slope solar still with internal reflectors and a finned system at the absorber plate, in it 30 experimental tests were made with 3 L of water, for which temperature measurements were obtained, mainly at the glass cover, the absorber plate, fluid and at the environment, as well as the incident solar radiation, the experimental information was obtained through ADAMS modules, type K thermocouples and a pyranometer, besides the distillate volume was measured with measuring cylinders. From the experimental data, a model was constructed to understand the effect of solar radiation and fluid temperature on distillate production. As a result, for this experiment a cubic function that describes de distillate volume behaviour was found, which only depends on the solar radiation and the official time, this equation has at least a 6% error on average regarding to the experimental distillate volume.
Speed PID controller simulation of a reaction wheel for CubeSat orientation applications
Authors: Medina I , Santiago L , Hernández-Gómez J J , Castillo R , Couder-Castañeda C 
Published: March 2021

Abstract
CubeSat technology is a low-cost alternative for space research in universities worldwide, promoting research areas in tele-detection, Earth and space observation, telecommunications, meteorology, etc. In this sense, Attitude and Determination Control Subsystem (ADCS) plays a key role in order to achieve a fast and precise orientation of the satellite, aiding the system by acquiring the specific and critical angles they require to accomplish the space mission. Therefore, choosing adequate actuators is key for the correct manipulation of the CubeSat, and it must consider size, weight and electrical power usage limitations of the CubeSat Standard. ADCS actuators must generate a quick response to generate an active momentum that modifies the satellite attitude. This work proposes a speed PID controller for a reaction wheel using low-cost materials for its implementation in 1U CubeSats.
Evaluation of a microinjection system for severe dry eye treatment
Authors: Meni-Babakidi Narcisse , Viramontes-Gamboa Gonzalo , Ibarra-Bracamontes Laura Alicia , Luna-Reyes Israel 
Published: March 2021

Abstract
This article presents the experimental results of a series of analysis and validation tests carried out on a microinjection system designed to deliver artifitial tears to patients suffering of severe dry eye. The microinjector has the following characteristics: high efficiency and precision, user friendly, portable (8.5 × 4.5 × 2.5 cm) and low manufacturing and assembling costs. The microinjector overcomes many of the shortcomings inherent to the manual method drip, it has a syringe reservoir to keep and deliver the artifitial tears. An electronically driven plunger pushes the solution into a capillary that transfer it to the patient’s eyes. The programmed time to deliver the tears fluid is set by the ptient through a “C” program in an Android based device. The real delivering time differs slightly from the programmed one due to frictional effects between the plunger and the syringe walls. The validation tests had the objective to quantify the time difference between the programmed and real delivering times, using as artifitial tears the Lagricel Ofteno brand, whis is the most used in Mexico. Two differentiable tests were done, in one test the plunger was lubricated with silicon oil (Ardes brand) for its compararation with the case where no lubricant is used. All test were done with an operating flow rate range of 0.13 - 60 µL/min). The results show that the microinjection system has the ability to offer high performance and precision with ± 0.191 and ± 0.137 % average error respectively for non-lubricated vs. lubricated tests.
The microinjection system can also be used for another compatible biomedical applications like chemotherapy, insulin administration, liquid drug delivery, among others adapting certain injection characteristics (flow rates and time).
Theoretical study of the open circuit voltage decay on Organic Photovoltaic (OPV) solar cells based on space radiation ionizing damage
Authors: Piña-López I , García-Ruiz K M , Barrueta-Flores C , Amador-Bedolla C 
Published: March 2021

Abstract
Organic photovoltaic (OPV) solar cells have progressed quite significantly as an affordable energy technology, with high-throughput roll-to-roll solution processing driving down costs to the point of competitiveness with current technologies. They potentially offer significant advantages over classical inorganic semiconductor cells; specifically, down costs, lightness, flexibility and controlled donor-acceptor film composition. Our specific interest is based on the applicability of organic photovoltaics cells for use in space based solar panels. The present work is a theoretical study of ionizing radiation effects in the organic photovoltaic structure P3HT: PCBM for total accumulated doses up to 1kGy (SiO2). We find that the open circuit voltage (Voc) varies with the accumulation of irradiation; however, other parameters such as relaxation time, short circuit current, and charge carrier density remain to first order constant. At the interface, the energetic mismatch of the molecular orbitals provides enough driving force to split the exciton in order to create free charge carriers (an electron (e-) and the corresponding hole (h+)). This is consistent with observations on preirradiation cases that depend directly on the Voc, due to carriers and quasi states; this leads to a linear recombination according to the Dose Damage Displacement (Dd) and Non-Ionizing Energy Loss (NIEL). Finally, we conclude that the organic photovoltaics will survive in a space environment up to 1 kGy (SiO2), contrary to popular belief that organics would be radiation “soft.”
Evaluation of heat transfer during the process of heating water in containers using a solar cooker box-type
Authors: Terres H , Chávez S , Lizardi A , Alvarez E 
Published: March 2021

Abstract
This work presents the experimental results and the evaluation of the heat transfer mechanisms by conduction, convection, and radiation that occur during the water heating process inside four containers with volumes of 250, 500, 750, and 1000 ml. using as for this process a box-type solar cooker. For the experimental measurements, a type k thermocouple arrangement was used, located in the water, the exterior surfaces of the containers, and the glass that forms part of the solar cooker cover. For the acquisition of the data perceived by the thermocouples, a Compact Field Point from National Instruments was implemented and for the measurement of global solar radiation, an Eppley 8-48 radiometer was used. The results obtained from the evaluation show that the most important heat transfer mechanism is by conduction located in the exterior glass of the solar cooker cover and the convection heat transfer in this same glass is the one with the lowest values. The evaluation of the results achieved contributes to the knowledge of the operation of solar cookers, which can contribute to the design and improvements of these solar energy devices.
LaAlO3:Pr3+ as photon radiotherapy dosimeter
Authors: Barrera-Angeles A A , Ugalde M A , Nolasco D , Gutiérrez-Márquez J G , Morales-Hernández A , Zarate-Medina J , Rivera-Montalvo T 
Published: March 2021

Abstract
The intention of radiotherapy is to control and cure tumor while avoiding late effects caused by radiation. High energy photon beam dose can be determined by different modalities. In this paper, dosimetric properties of praseodymium doped lanthanum aluminate exited by X-ray beams are reported. LaAlO3:Pr3+ powders samples were prepared using modified Pechinis’s method. The formations of the obtained samples were confirmed by an X-ray diffraction patterns. TL glow curve and dosimetric characteristics of LaAlO3:Pr3+ powder samples were investigated under X-ray irradiation effects. All TL measurements were made using an automated Harshaw TL reader 5500. TL glow curves were obtained using a constant heating rate 10 °C/s from room temperature up to 350°C in a nitrogen atmosphere. The dose response and minimum detectable dose (MDD) values of the samples were determined. Dosimetric characteristics of the samples were carefully analyzed. Experimental results of TL dosimetric characteristics of the powder samples appear to have potential application for high energy photon beam dose measurements.
Thermoluminescence properties of high-dose gamma-irradiated diamond films
Authors: Cruz-Zaragoza E , Marcazzó J , Pérez Ramírez E , Meléndrez R , Barboza-Flores M 
Published: March 2021

Abstract
Thermoluminescence (TL) properties of gamma-irradiated chemical vapor deposition (CVD) diamond films at high doses are presented. Samples of undoped and nitrogen-doped CVD diamonds were exposed to 60Co gamma sources and TL intensity as a function of the dose was analyzed. To evaluate the feasibility of using these materials as TL high-dose dosimeters, reproducibility of the TL signal, and the TL response as a function of absorbed dose from 100 Gy up to 10 kGy were studied. Furthermore, the fading of the TL glow curve was analyzed. Finally, to estimate the kinetics parameter values associated with the trap distribution in the CVD diamond, a computerized deconvolution was carried out by using the general order kinetics (GOK) model.