bluuebunny/crossref_metadata_2025 huggingface dataset:
Remodeling beim equinen Asthma – Einfluss von Haltungsoptimierung und pharmakologischer Therapie
Authors: Barton Ann Kristin , Gehlen Heidrun
Published: September 2021

Der Begriff Remodeling beschreibt den Prozess, der zu Veränderungen in Struktur und Aufbau im Vergleich zu gesundem Gewebe führt. Zumindest beim schweren equinen Asthma kommt es hauptsächlich, aber nicht ausschließlich, infolge der neutrophilen Entzündung zu einer Hypertrophie der glatten Bronchial- und arteriellen Gefäßmuskulatur sowie zu einer Fibrosierung der luftführenden Wege, aber auch des pulmonalen Interstitiums. Zur milden bis moderaten Form des equinen Asthmas ist bislang deutlich weniger bekannt. Lange wurde davon ausgegangen, dass das Remodeling irreversibel ist. Während dies für die glatte Bronchialmuskulatur weitgehend bis >heute gilt, gibt es beim Remodeling der extrazellulären Matrix der Lamina propria der Atemwege neue Erkenntnisse. Sowohl eine langfristige Remission durch konsequente Haltungsoptimierung als auch Glukokortikoide können den Kollagengehalt hier annähernd normalisieren. Das Remodeling der arteriellen Gefäßmuskulatur ist durch langfristige Haltungsoptimierung über mindestens 12 Monate und Bronchodilatatoren, nicht aber alleinig durch inhalative Glukokortikoide ebenfalls reversibel. Obwohl noch nicht abschließend geklärt, könnte die mit guter Prognose oft ausheilende milde bis moderate Form des equinen Asthmas eine Vorläuferform der schweren Form sein, bei der auch in der Phase der Remission Einschränkungen der Lungenfunktion nachweisbar sind, selbst wenn keine offensichtlichen klinischen Symptome vorliegen. Somit sind die frühzeitige Diagnosestellung des equinen Asthmas und ein früher Therapiebeginn entscheidend, damit zu Beginn der Behandlung möglichst wenige irreversible Veränderungen vorliegen. Der konsequenten Haltungsoptimierung kommt therapeutisch die größte Bedeutung zu, daneben sollten Glukokortikoide und Bronchodilatatoren eingesetzt werden.
Internal Pudendal Artery Angioplasty to Rescue Penile Gangrene.
Authors: Shah Pratik , Someshwar Vimal , Mundada Krishna , Waigankar Santosh
Published: September 2021

Internal pudendal artery (IPA) is a branch of internal iliac artery that mainly supplies the perineal organs and external genitalia. Any obstruction in the artery seen in diabetics, hypertensives, or chronic kidney disease-induced calciphylaxis leads to decreased blood flow and may cause gangrene. IPA angioplasty is a known therapeutic procedure for erectile dysfunction and has shown promising results. However, similar procedure to relieve arterial blockade may be used to stop spread of penile gangrene and save the anatomical and physiological functions of the penis. We report a novel case of IPA angioplasty in patient of penile gangrene to circumvent total penectomy.
Contaminated Toothbrushes and Potential COVID-19 Transmission: Concerns and Recommendations
Authors: Vergara-Buenaventura Andrea , Castro-Ruiz Carmen
Published: September 2021

Substantial past evidence has demonstrated microbial contamination of oral devices and possible transmission of viral diseases, drawing attention to habits related to using and storing toothbrushes. Since toothbrushes are in intimate contact with the oral cavity, the question arises as to whether they can transmit COVID-19.

An electronic search was performed in four databases to identify relevant literature about the possible contamination or transmission of SARS-CoV-2 through toothbrushes until May 2021. Forty-five records were retrieved, and after a thorough search, we found no articles reporting significant evidence. However, studies with other viral diseases have indicated that improper use and storage of toothbrushes could contribute to indirect disease transmission.

Therefore, this narrative review supports the implementation of toothbrush disinfection and storage measures to minimize the risk of SARS-CoV-2 infection among cohabitants and community settings. Finally, recommendations and a suggested protocol to reduce the potential risk of transmission between cohabitants are provided.
Intersectionality as a Framework for Understanding Adolescent Vulnerabilities in Low and Middle Income Countries: Expanding Our Commitment to Leave No One Behind
Authors: Baird Sarah , Camfield Laura , Ghimire Anita , Hamad Bassam Abu , Jones Nicola , Pincock Kate , Woldehanna Tassew
Published: September 2021

Given increasing policy attention to the consequences of youth marginalisation for development processes, engaging with the experiences of socially marginalised adolescents in low- and middle-income countries (including those who are out of school, refugees, married, with disabilities or adolescent parents) is a pressing priority. To understand how these disadvantages—and adolescents’ abilities to respond to them—intersect to shape opportunities and outcomes, this Special Issue draws on the Gender and Adolescence: Global Evidence conceptual framework which accounts for gender roles and norms, family, community and political economy contexts in shaping adolescents’ capabilities. Implicitly critiquing a focus within youth studies on individual agency, the articles advance our understanding of how adolescents’ marginalisation is shaped by their experiences, social identities and the contexts in which they are growing up. An analytical framework foregrounding intersectionality and collective capabilities offers a means to politicise these findings and challenge uncritical academic celebration of individual agency as the means to address structural problems.
A dual-band power divider based on higher-order modes of spoof surface plasmon polaritons
Authors: Mirhadi Salma , Komjani Nader
Published: September 2021

In this paper, a dual-band power divider is presented based on the propagation of the higher-order modes of spoof surface plasmon polaritons (SSPPs). A hollow rectangular groove is introduced as a unit cell, and its dispersion characteristics for higher modes and the fundamental mode are examined. Compared with the traditional rectangular groove unit cell, the proposed unit cell provides extreme electromagnetic wave confinement for higher-order modes. In addition, the second and fourth modes are even and can be excited by a coplanar waveguide. By utilizing the even modes of the proposed unit cell, a dual-band transmission line and a dual-band power divider are designed so that the operating bands can be controlled by the inner and outer depth of the grooves. The dual-band SSPP transmission line and the dual-band power divider are manufactured and tested to validate the design procedure. Finally, the measurement results show good agreement with the simulations, demonstrating the effectiveness and robustness of the design procedure.
Effect of ion motion on breaking of longitudinal relativistically strong plasma waves: Khachatryan mode revisited
Authors: Bera Ratan Kumar , Mukherjee Arghya , Sengupta Sudip , Das Amita
Published: September 2021

The effect of ion motion on the spatiotemporal evolution of a relativistically strong space charge wave is studied using a 1D fluid simulation code. In our simulation, these waves are excited in the wake of a rigid electron beam propagating through a cold homogeneous plasma with a speed close to the speed of light. It is observed that the excited wave is a mode as described by Khachatryan [Phys. Rev. E 58, 7799–7804 (1998)] whose profile gradually sharpens and the wave eventually breaks after several plasma periods exhibiting explosive behavior. It is found that breaking occurs at amplitudes, which is far below the breaking limit analytically derived by Khachatryan [Phys. Rev. E 58, 7799–7804 (1998)]. This phenomenon of wave breaking, at amplitudes well below the breaking limit, is understood in terms of phase mixing of the excited wave. It is further found that the phase mixing time (wave breaking time) inversely scales with the energy density of the wave.
Ultra-high adsorption behavior of zeolitic imidazole framework-67 nanoparticles for removing brilliant green dye
Authors: Wang Hongxin , Cheng Zhenbang , Zhang Peng , Ye Jian , Ding Lin , Jia Weijian
Published: September 2021

Metal–organic frameworks have been a new type of adsorbent in environmental remediation due to their simple preparation processes and stable chemical properties in water. However, they are limited by their low adsorption capacities to some organic pollutants. Herein, ZIF-67 nanoparticles with a high Brunauer, Emmett and Teller (BET) surface area were designed and successfully synthesized by a time-saving, low cost, and environment liquid phase synthesis method at room temperature. The physicochemical properties of ZIF-67 nanoparticles were well studied by various measurements, such as x-ray diffraction, BET analysis, and scanning transmission microscopy. Meanwhile, the ZIF-67 nanoparticles with the stable structure are introduced as the adsorbent for trapping brilliant green in pollutant water, exhibiting the ultra-high adsorption capacity of 1989 mg g−1 due to their high specific surface area (425 m2 g−1) and the interaction between π–π and the benzene ring. Moreover, the ZIF-67 showed acceptable reusability after regeneration with ethanol. Evidently, the ZIF-67 nanoparticles show excellent adsorption performances for organic dyes. This work can give a new application to zeolite imidazole framework materials in water treatment.
Enhanced photon emission from free electron excitation of a nanowell
Authors: Nussupbekov Ayan , Adamo Giorgio , So Jin-Kyu , Wu Lin , Chong Y. D. , Wong Liang Jie
Published: September 2021

Efficient nanoscale light sources are sought after for applications such as sensing, imaging, and the development of photonic circuits. In particular, free electron light sources have gained much attention due to their ability to tune and direct light emission. Here, we show that radiation from free electrons passing through a 100 nm wide nanohole can reach as high as 90% of the theoretical limit. This is accomplished through the introduction of a circular nanoridge around the hole to form a structure we call the nanowell. The power radiated from the nanowell exceeds that of a regular nanohole by over 100 times and that of nanoholes surrounded by other features, such as bullseyes, by similar enhancement factors. Upon varying the structural parameters of the nanowell, the peak output wavelength can be tuned over a broad frequency range from the visible to the near-infrared. This reveals a route to extracting power from free electrons via material nanopatterning.
Parallel propagating modes: A transition from electromagnetic proton cyclotron to electron firehose instability
Authors: Ali Z. , Sarfraz M.
Published: September 2021

Expansion of solar wind into the interplanetary space generates temperature anisotropy that cannot be justified by adiabatic fluid theory. Kinetic instabilities driven by the interplay between electrons and protons temperature anisotropy may be operative in order to explain the actual state of solar wind reported by satellite observations. Based on the temperature anisotropy, T⊥/T∥, and alternative different plasma beta, β, regimes of solar wind species, we investigate the unified wave spectrum where left-hand polarized electromagnetic proton cyclotron and electron firehose instabilities may co-exist or transit with each other. Linear stability analysis catches the co-existence/transition of these instabilities in the different propagation domain. A moment-based quasilinear approach is adopted to highlight the feedback effects of these instabilities on the initial distributions and also to validate the transition during the non-linear (or quasilinear) time-evolution of the instabilities. Looking at the solar wind observations, we assume a bi-Maxwellian dual core-halo electron and proton model that allows solar wind species temperatures to vary in time t in addition. By incorporating the radial expansion effects and inhomogeneities, our present findings may be applicable to the First Solar Parker Probe observations.
Rapid droplet spreading on a hot substrate
Authors: Cheng Yongpan , Li Erqiang , Wang Jinxin , Yu Peng , Sui Yi
Published: September 2021

Due to its high efficiency, droplet spray cooling is widely used in various industrial and scientific applications. The spreading of droplets can greatly affect heat transfer, and temperature can also affect the dynamics of droplet spreading. In this study, both experiment and numerical simulations are used to investigate the effects of temperature on droplet spreading on a hot substrate from the nanoscale dynamics of moving contact lines to macroscale thermo-capillary flows. It is found that with increasing substrate temperature, during fast droplet spreading, satellite droplets transit from first-stage pinch-off to second-stage pinch-off and then to no pinch-off. These phenomena can be attributed to the effects of temperature at different scales. In the nanoscale region of moving contact lines, temperature and corresponding viscosity can alter the dynamic wetting angle of the moving contact lines. At the microscale interface region, temperature can change the viscosity near droplet interfaces, leading to variation in the viscous force. At the macroscale droplet region, the temperature of a droplet can change its surface tension, leading to thermo-capillary flow along the droplet interface. The pinch-off dynamics of droplet spreading on hot substrate can be analyzed according to the propagation of interfacial capillary waves at different temperatures and the resultant neck dynamics. These findings provide insight into droplet-spreading regimes on hot substrates under different temperatures.
A large-eddy simulation study on vortex-ring collisions upon round cylinders
Authors: New T. H. , Gotama G. J. , Vevek U S
Published: September 2021

A large-eddy simulation based numerical study was conducted on head-on collisions between vortex-rings and round cylinders. The vortex-ring Reynolds number was Re = 4000, while the ratio of the cylinder diameter to vortex-ring diameter (i.e., diameter ratio, D/d) was varied from 4 to 1. Vortical behavior predicted by the present simulations is observed to agree well with an earlier experimental study [New, T. H., and Zang, B., “Head-on collisions of vortex rings upon round cylinders,” J. Fluid Mech. 833, 648 (2017)]. The present simulations also reveal additional flow details on the vortex dynamics and vortex-core trajectories, which have not been observed previously. First, vortex-dipoles produced by D/d ≤ 2 cylinders are cross sections of elliptic vortex-ringlets formed via vortex disconnection/reconnection of secondary vortex-ring segments. Second, the aspect ratio of the elliptic vortex-ringlets increases when a smaller diameter-ratio cylinder is used, and finally, they undergo axis-switching behavior. Furthermore, up to three sets of tertiary vortex-ring cores are formed along the D/d = 2 and 1 cylinder straight-edges where they subsequently merge with the secondary vortex-ring cores within the confines of the primary vortex-ring cores. This merged vortex core moves toward the collision axis and forms an inner vortex-dipole with a wall separated vortex. Along the convex surface, up to two sets of tertiary vortex-ring cores are observed for D/d = 2 and 1 cylinders, and trajectories of the vortex-dipoles agree well with the past experimental results. These observations support the notion that higher vortex-stretching levels resulting from the use of small diameter-ratio cylinders with higher surface curvatures underpin the wide range of vortical behavior observed here.
Measurement of thermal conductivity and thermal diffusivity of one-dimensional-system material by scanning electron microscopy and infrared thermography
Authors: Baskaran Palanisamy , Nanao Ryo , Yamanashi Yojiro , Sakaida Masaki , Suzuki Yuhei , Navaneethan Mani , Nisha Kuruvankatil Dharmajan , Hayakawa Yasuhiro , Inokawa Hiroshi , Shimomura Masaru , Murakami Kenji , Ikeda Hiroya
Published: September 2021

A novel measurement system consisting of scanning electron microscopy and infrared (IR) thermography has been constructed to measure the thermal conductivity and the thermal diffusivity on a micro-/nanometer scale. In this study, we measured them for a stainless-steel wire with a diameter of 50 μm to demonstrate the validity of our system. The time evolution of temperature distribution on the whole of the stainless-steel wire was recorded by the IR thermograph when the wire was irradiated by the electron beam (EB). A time response of the wire temperature corresponding to the on/off of the EB irradiation was clearly observed, indicating that local EB heating was realized. In addition, the experimental time evolution of temperature at its transient phenomena was in good agreement with the theoretical calculation based on a one-dimensional (1D) equivalent-circuit model of heat flow coupled with electric current, where the thermal parameters, such as thermal conductivity and heat capacitance, were set to bulk values. Therefore, it can be concluded that our system is valid to evaluate the thermal conductivity of the 1D wire sample. For evaluating the thermal diffusivity of the wire sample, we applied a periodic EB irradiation by a rectangular wave with a frequency of 0.25 Hz. The thermal diffusivity was evaluated to be (2.8 ± 0.6) × 10−5 m2 s−1, which was seven times as large as that of bulk stainless steel. Our system can be applied to an AC calorimetry method for a 1D system sample after the analysis procedure is further modified.
An extended slowing down distribution function of alpha particles with non-uniform ion and electron temperature
Authors: Jhang Hogun
Published: September 2021

We present an approximate expression for an isotropic alpha particle slowing down distribution function that is applicable down to the lowest velocity limit. The effect of non-uniform electron and ion temperature, i.e., the different rate of energy equilibration, is retained in this expression. Application of the extended slowing down distribution function shows that keeping the non-uniformity effect may have an influence on the alpha particle–background plasma interaction by the modification of the energetic particle contents in comparison with the conventional slowing down distribution function.
The centrifugal viscometer
Authors: Shih Chih-Hsin , Chang Chia-Chin , Liu Chung-Yi , Wu Ho-Chin
Published: September 2021

In this study, a viscometer, which can measure the viscosity of low-volume liquids (25 μl) within 30 s, was developed on a centrifugal platform. The centrifugal viscometer consists of a disk platform and a motor. Under disk rotation, centrifugal, Coriolis, and viscosity-induced drag forces result in deflection of liquid flow. The viscosity of the liquid sample is determined by the deflection angle of the liquid, which can be examined through image analysis or visual inspection. The viscosities of a series of Newtonian model fluids were tested by the centrifugal viscometer and the results showed good agreement with the ones tested by a conventional rotational viscometer. Since the centrifugal viscometer only requires a motor to function, the microfluidic disk can be produced in large quantities at a low cost through injection molding, and the deflection angle can be detected through visual inspection, it provides an inexpensive, easy to operate, and portable approach to measure low-volume liquid viscosity.
Energy conversion efficiency of electrical exploding foil accelerators
Authors: Ichihara D. , Fukushima G. , Kuwabara D. , Sasoh A.
Published: September 2021

We evaluate the energy conversion efficiency of an electrical exploding foil accelerator that accelerates a thin dielectric foil (called the flyer) to more than 1 km/s, which is propelled by electrically exploded bridge material. The effective flyer mass ejected from the accelerator is estimated by impulse measurements obtained using a gravity pendulum as well as by time-resolving flyer velocity measurements obtained using a photonic Doppler velocimetry system. For two different bridge sizes (0.2 and 0.4 mm), the flyer velocity and impulse increase with the input energy at the bridge section. The maximum flyer velocity and impulse, that is, 4.0 km/s and 67 µN s, respectively, are obtained by supplying 0.33 J of input energy. Upon increasing the input energy, the effective flyer mass also increases and exceeds the designed-bridge mass for both bridge sizes. The energy conversion efficiency from input electrical energy to flyer kinetic energy is calculated based on the effective flyer mass, velocity, and input energy. Both bridge sizes show comparable efficiencies: 27% and 30% for 0.2 and 0.4 mm bridges, respectively. The efficiency increases with increasing specific input energy at least up to 15 MJ/kg for the 0.4 mm bridge, whereas the efficiency of the 0.2 mm bridge above 30 MJ/kg decreases. This is owing to the excessively high input energy density in the 0.2 mm bridge, which causes the effective flyer mass to increase by including surrounding materials. These results indicate that the specific input energy should be optimized for obtaining maximum efficiency.
Immersed boundary conditions for moving objects in turbulent flows with the lattice-Boltzmann method
Authors: Cheylan Isabelle , Favier Julien , Sagaut Pierre
Published: September 2021

An immersed boundary method is coupled to a turbulent wall model and Large Eddy Simulation, within the Lattice-Boltzmann framework. The method is able to handle arbitrarily moving objects immersed in a high Reynolds number flow and to accurately capture the shear layer and near wall effects. We perform a thorough numerical study which validates the numerical method on a set of test-cases of increasing complexity, in order to demonstrate the application of this method to industrial conditions. The robustness and accuracy of the method are assessed first in a static laminar configuration, then in a mobile laminar case, and finally in a static and oscillating turbulent simulation. In all cases, the proposed method shows good results compared to the available data in the literature.
Replacing high-risk radioactive materials remains a challenge
Authors: Lopatka Alex
Published: September 2021

The medical industry is substituting x-ray sources for cesium-based blood irradiators. Other industries are also exploring alternative technologies.
Thermodynamic mechanism of the high magnetic-field-induced morphology of ferrite
Authors: Zhang Dong , Hou Tingping , Wu Kaiming , Wang Yu , Lin Hengfu
Published: September 2021

The stability of the ferrite morphology under a high magnetic field has been investigated according to the combination of the extended Weiss molecular field theory and the principle of minimum energy. The results showed that the ferromagnetic phase region decreases significantly with the increase of total angular momentum, whereas the paramagnetic phase region has the opposite tendency. The magnetic-field-induced morphology is noted to be closely related to the angular momentum, magnetic moment and interfacial energy. Based on the principle of minimum energy, the magnetic-field-induced aspect ratio (2.48:1) of the ferrite grains is in good agreement with the previous experimental data.
Topological theory of inversion-breaking charge-density-wave monolayer 1T-TiSe2
Authors: Hsu Ming-Chien , Singh Bahadur , Hsu Chuang-Han , Xu Su-Yang , Lin Hsin , Huang Shin-Ming
Published: September 2021

A charge density wave (CDW) of a nonzero ordering vector q couple electronic states at k and k + q statically, giving rise to a reduced Brillouin zone due to the band folding effect. Its structure, referred to an irreducible representation of the little group of q, would change the symmetry of the system and electronic structure accompanying possible change of band inversion, offering a chance of the topological phase transition. Monolayer 1T-TiSe2 is investigated for it shows an unconventional CDW phase having a triple-q

M

1

−

structure. Moreover, the coupling between the triple-q component of the

M

1

−

CDW will inevitably produces a small

M

1

+

CDW. The CDW yields a band inversion in 1T-TiSe2 but different types of CDW can affect the electronic structure and system topology differently. The impact of CDW of different types was studied by utilizing a symmetrization–antisymmetrization technique to extract the

M

1

−

and

M

1

+

CDW contributions in the density functional theory-based tight-binding model and study their effects. The results are consistent with the parity consideration, improving understanding of topology for a CDW system with and without parity.
Hyperonic neutron stars: reconciliation between nuclear properties and NICER and LIGO/VIRGO results
Authors: Lopes Luiz L
Published: September 2021

Using an extended version of quantum hadrodynamics, I propose a new microscopic equation of state (EoS) that is able to correctly reproduce the main properties of symmetric nuclear matter at the saturation density, as well as produce massive neutron stars and satisfactory results for the radius and the tidal parameter. I show that this EoS can reproduce at least a 2.00 solar mass neutron star, even when hyperons are present. The constraints about the radius of a 2.00 M
⊙ and the minimum mass that enables a direct Urca effect are also checked.
Influence of various shapes of nanoparticles on unsteady stagnation-point flow of Cu-H2O nanofluid on a flat surface in a porous medium: A stability analysis
Authors: Banerjee Astick , Bhattacharyya Krishnendu , Mahato Sanat Kumar , Chamkha Ali J.
Published: September 2021

The nanofluid and porous medium together are able to fulfill the requirement of high cooling rate in many engineering problems. So, here the impact of various shapes of nanoparticles on unsteady stagnation-point flow of Cu–H2O nanofluid on a flat surface in a porous medium is examined. Moreover, the thermal radiation and viscous dissipation effects are considered. The problem governing partial differential equations are converted into self-similar coupled ordinary differential equations and those are numerically solved by the shooting method. The computed results can reveal many vital findings of practical importance. Firstly, dual solutions exist for decelerating unsteady flow and for accelerating unsteady and steady flows, the solution is unique. The presence of nanoparticles affects the existence of dual solution in decelerating unsteady flow only when the medium of the flow is a porous medium. But different shapes of nanoparticles are not disturbing the dual solution existence range, though it has a considerable impact on thermal conductivity of the mixture. Different shapes of nanoparticles act differently to enhance the heat transfer characteristics of the base fluid, i.e., the water here. On the other hand, the existence range of dual solutions becomes wider for a larger permeability parameter related to the porous medium. Regarding the cooling rate of the heated surface, it rises with the permeability parameter, shape factor (related to various shapes of Cu-nanoparticles), and radiation parameter. The surface drag force becomes stronger with the permeability parameter. Also, with growing values of nanoparticle volume fraction, the boundary layer thickness (BLT) increases and the thermal BLT becomes thicker with larger values of shape factor. For decelerating unsteady flow, the nanofluid velocity rises with permeability parameter in the case of upper branch solution and an opposite trend for the lower branch is witnessed. The thermal BLT is thicker with radiation parameter. Due to the existence of dual solutions, a linear stability analysis is made and it is concluded that the upper branch and unique solutions are stable solutions.
Demonstration of Faraday anomalous dispersion optical filter with reflection configuration
Authors: Liu Yi , Yang Baodong , Wang Junmin , Huang Wenyi , Gou Zhiyu , Zhou Haitao
Published: September 2021

A narrow linewidth Faraday anomalous dispersion optical filter (FADOF) with reflection configuration is achieved for the first time based on the cesium (Cs) ground state 6S1/2 to the excited state 6P3/2 transition at 852 nm. Compared with the conventional FADOF with transmission configuration, reflection-type FADOF can greatly improve the transmittance of optical filter under the same experimental parameters, because it allows signal light to go and return through the atomic vapor cell. In our experiment, peak transmittance at Cs 6S1/2
F = 4–6P3/2 transition is 81% for the reflection-type FADOF, and while 54% for the transmission-type FADOF when the temperature of Cs vapor cell and the axial magnetic field are 60 °C and 19 G. The idea of this reflection-type FADOF design has the potential to be applied to the FADOF operating between two excited states to obtain higher transmittance.
Electron-impact ionization cross section calculations for lithium-like ions
Authors: Bian Guo-Jie , Chang Jyh-Ching , Huang Ke-Ning , Wu Chen-Sheng , Cheng Yong-Jun , Wang Kai , Wu Yong
Published: September 2021

The electron-impact ionization of lithium-like ions C3+, N4+, O5+, Ne7+, and Fe23+ is studied using a combination of two-potential distorted-wave and R-matrix methods with a relativistic correction. Total cross sections are computed for incident energies from 1 to 10 times of ionization energy and better agreements with the experimental results are obtained in comparison with the theoretical data available. It is found that the indirect ionization processes become significant for the incident energy larger than about four times of the ionization energy. Contributions from the exchange effects along the isoelectronic sequence are also discussed and found to be important. The present method can be used to obtain systematic ionization cross sections for highly charged ions across a wide incident energy range.
Numerical simulation of two droplets impacting upon a dynamic liquid film
Authors: Zeng Quan-Yuan , Zhang Xiao-Hua , Ji Dao-Bin
Published: September 2021

The impact of droplets on the liquid film is widely involved in industrial and agricultural fields. In recent years, plenty of works are limited to dry walls or stationary liquid films, and the research of multi-droplet impact dynamic films is not sufficient. Based on this, this paper employs a coupled level set and volume of fluid (CLSVOF) method to numerically simulate two-droplet impingement on a dynamic liquid film. In our work, the dynamic film thickness, horizontal central distance between the droplets, droplets’ initial impact speed, and simultaneously the flow velocity of the moving film are analyzed. The evolution phenomenon and mechanism caused by the collision are analyzed in detail. We find that within a certain period of time, the droplet spacing does not affect the peripheral crown height; when the droplet spacing decreases or the initial impact velocity increases, the height of the peripheral crown increases at the beginning, and then, because the crown splashed under Rayleigh–Plateau instability, this results in the reduction of the crown height. At the same time, it is found that when the initial impact velocity increases, the angle between the upstream peripheral jet and the dynamic film becomes larger. The more obvious the horizontal movement characteristics, the more restrained the crown height; the spread length increases with the increase of the dynamic film speed, droplet spacing and the initial impact velocity. When the liquid film is thicker, more fluid enters the crown, due to the crown being unstable, the surface tension is not enough to overcome the weight of the rim at the end of the crown, resulting in droplets falling off.
High-confinement ultra-wideband bandpass filter using compact folded slotline spoof surface plasmon polaritons
Authors: Zhang Xue-Wei , Liu Shao-Bin , Wang Ling-Ling , Yu Qi-Ming , Jian-Lou 健 , Sun Shi-Ning
Published: September 2021

A novel bandpass filter (BPF) based on spoof surface plasmon polaritons (SSPPs) using a compact folded slotline structure is proposed and experimentally demonstrated. The proposed novel SSPPs structure compared with a conventional plasmonic waveguide with slot line SSPPs unit structure at the same size, the considerable advantages in much lower asymptotic frequency with tight field confinement, which enable the proposed filter to be more miniaturization. A high-efficient mode conversion structure is designed to transition from TE-mode to SSPPs-mode by gradient slotline lengths. The low-frequency stop-band can be committed with microstrip to slotline evolution on both sides of the dielectric, while the high-frequency cutoff band is realized by the proposed SSPPs structure. The influence of dispersion relation, electric field distribution, surface current, and structural parameters on the transmission characteristics of the proposed BPF are analyzed by finite difference time domain (FDTD). To validate the design concept, the prototype of the miniaturized SSPPs BPF has been manufactured and measured. The experimental results show high performance of the fabricated sample, in which the working in a range of 0.9 GHz–5.2 GHz with the relative bandwidth is 142%, the insertion loss less than 0.5 dB, the reflection coefficient less than −10 dB, and the group delay is less than one ns. This works provides a mirror for realizing the miniaturization of waveguides, and the application and development of high-confinement SSPPs functional devices in the microwave and THz regimes.
Improved blue quantum dot light-emitting diodes via chlorine passivated ZnO nanoparticle layer*
Authors: Qu Xiangwei , Ma Jingrui , Jia Siqi , Wu Zhenghui , Liu Pai , Wang Kai , Sun Xiao-Wei
Published: September 2021

In blue quantum dot light emitting diodes (QLEDs), electron injection is insufficient, which would degrade device efficiency and stability. Herein, we employ chlorine passivated ZnO nanoparticles as electron transport layer to facilitate electron injection into QDs effectively. Moreover, it suppresses exciton quenching at the QD/ZnO interface by blocking charge transfer channel. As a result, the maximum external quantum efficiency of blue QLED was increased from 2.55% to 4.60%, and the operation lifetime of blue QLED was nearly 4 times longer than that of the control device. Our work indicates that election injection plays an important role in blue QLED efficiency and stability.
Rural institutions, social networks, and self-organized adaptation to climate change
Authors: Fischer Harry W , Chhatre Ashwini , Devalkar Sripad , Sohoni Milind
Published: September 2021

Support for rural livelihoods to adapt to climate change is a top policy priority around the world. We advance the concept of ‘self-organized adaptation’ to analyze how long-term pathways of transformation come about as the organic outcome of farmers’ incremental and continuous responses to climate and other challenges. Through an analysis of four decades’ responses to changing climate conditions in an agricultural system of the Indian Himalayas, we show how several key policy interventions—institutional support for the dissemination of agricultural knowledge, investments in infrastructure, and strengthening of market linkages—have produced favorable conditions for successful, long-term self-organized adaptation to climate change. This has led to the transformation of an agricultural system specialized in apple production to one with a great diversity of fruit, vegetable, and food grain crops. We find that farmers growing these crops cluster into five distinct agricultural portfolios that reflect the constraints and opportunities that different farmers face, and which are patterned by interaction with rural institutions and household social networks. We highlight the role of distributed decision-making in shaping broader trajectories of systemic transformation, and we argue for the need to move beyond pre-defined climate interventions toward the identification of policy mechanisms that can support more effective self-organization over the long-term.
Optimization, modelling and simulation to scale-up the production of rice bran extract and defatted rice bran
Authors: Fitriyano G , Fithriyah N H , Nugrahani R A , Syamsudin A B , Kosasih M
Published: September 2021

Rice bran is the source of rice bran oil, but much of it is used as livestock feed without being extracted for oil. Some food industries utilize the stabilized rice bran as a source of fiber, protein, and cooking oil. It contains lipase that catalyzes triglyceride hydrolyzation into glycerol and fatty acids, which leads to rancidity. A stabilization process must therefore be introduced to increase oxidation resistance in rice bran and oil hydrolysis. Defatted rice bran still contains protein, fiber, vitamins, and minerals. There has not been much research on integrated production process of crude rice bran oil and defatted rice bran. This research aimed to study the procedures to optimize, model, and simulate, generate Process Engineering Flow Diagram (PEFD). The phases in this study included laboratory-scale extraction with rice bran feed capacities of 10g, 25g, 100g, dan 500g; optimization using mathematical computations, simulations of mass-balance scale up and generation of PEFD from the pilot plant of 5kg rice bran capacity. The results of this research, including optimization, modelling, and simulation showed that to increase production scale from a number of raw materials of 57.690g to 5kg in a single batch required 5kg rice bran and 23.121kg n-hexane and produced 0.671kg oil and 4.121kg defatted rice bran, 13.212kg of reusable n-hexane and this study also provided a PEFD of the rice bran oil production process for a 5 kg rice bran capacity.
Reservoir properties prediction using seismic inversion and geostatistical integration
Authors: Dewanto O , Mulyatno B S , Ordas P R , Wibowo R C
Published: September 2021

Exploration and production in the sand reservoir still have their challenges due to the low porosity and permeability characteristics. This study was conducted to analyse the characteristics of a tight sand reservoir based on a log property distribution map, using acoustic impedance inversion and multi-attribute analysis. Stepwise regression multi-attribute analysis is a method that uses the best attributes to predict the target log by going through a trial and error process. Choosing the right seismic attributes can provide a better depiction of the target zone. This research was conducted to obtain a map of subsurface geological structures, acoustic impedance volumes. Then, we performed a multi-attribute analysis to obtain a prediction of volume log properties such as pseudo gamma-ray, density and porosity using the stepwise regression method. The results of acoustic impedance seismic inversion and stepwise regression multi-attribute analysis shows that the reservoir is a gas with tight sand lithology, which has a range of acoustic impedance values of 15,000 ((ft/s)*(g/cc)) up to 30,000 ((ft/s)*(g/cc)), porosity of 12% to 24%, and the distribution of Sw of 8-13%. The density and porosity maps obtained from the multi-attributes analysis can help in the long-term exploration and production stages. Its aims are to improve primary recovery and tertiary recovery, understanding the stratigraphic traps, and continuity of reservoir layers.
Spectrophotometric analysis of caffeine in local product of Arabica: observed at different roasted temperatures
Authors: Misto  , Alawiyah K , Rohman L , Supriyadi  , Mutmainnah  , Purwandari E
Published: September 2021

Indonesia’s geographical location supports the existence of various coffee commodities. As a plantation commodity, coffee has a high economic value. Coffee has a lot of substance that is beneficial to the body, one of is caffeine that serve to increase the stamina. Caffeine is naturally present in many types of plants as secondary metabolism. This research was done to know the content of caffeine in a local Arabica pure coffee with their variation of roasted temperatures. Coffee roasting is a stage of processing coffee beans into ready to grind, which can produce variations in the taste and content of coffee. The roasting process uses a roasting machine that automatically adjusts the roast temperature. Variations of roasted coffee are ground and used as a solution to determine the caffeine content. The determination of the coffee content is carried out using the spectrophotometric method, which measures the absorbance of caffeine in solution when it is passed by electromagnetic waves in the UV-Vis spectrum. The test results showed that the highest caffeine content was on samples of pure Arabica coffee with a roasted temperature of 195°C to 215°C with five levels of coffee roast. Caffeine content in sequential 3.217% and 2.597%.
Reservoir properties modelling using multi-attribute seismic analysis in south Sumatra basin, Indonesia
Authors: Mulyatno B S , Parameswari F S , Hikmah N , Dewanto O , Wibowo R C
Published: September 2021

Seismic inversion and multi-attribute analysis method are used in this research to characterize the reservoir properties. Where both of these methods will be resulted an acoustic impedance volume and log property volumes. The property log volumes were created from density, porosity, Gamma-Ray (GR) and Water Saturation (Sw) log. There are 4 wells that are used in this research, they are EM-31, EM-32, EM-33 and EM-34 and a 3D seismic data post-stack time migration. Based on a map of acoustic impedance distribution, the reservoir target has an acoustic impedance value of 6.000 ((m/s)*(g/cc)) to 8.000 ((m/s)*(g/cc)). Furthermore, based on the map of the distribution of the log property, the reservoir has a density value with a range of 2.3 g/cc up to 2.4 g/cc, porosity value > 10%, the GR value of less than 100 API and Sw 50% to 55%. Thus, it can be concluded that reservoir has a lithology of sandstones, has a fairly good porosity and contains oil fluids.
The effect of preloaded on delamination of composite laminate subjected to low energy impact
Authors: Sabli A S A , Morni M , Ahmad M Z H , Noorhalidi A H , Aminanda Y
Published: September 2021

The CFRP laminate composite is used widely especially in aerospace industry. The design concern of this type of structure is on its strength under impact loading even under low energy impact. Under low impact loading, delamination occurs and reduce the residual strength of laminate, therefore the necessity to predict this phenomena prior to its utilization. In practice the aircraft structure is subjected to pre-stress loading such as due to aerodynamics loading while in the same time loaded under impact loading due to, for example, birds impact. This paper deals with the investigation on the delamination trend of pre-stressed CFRP composite laminate subjected to low energy and low speed impact. A FE model is proposed and validated using published data. After validation confirmation, 2 types of pre-stressed; compression and tension are used to vary the pre-stress parameter. The pre-stress is modelled by prescribe displacement at both edge of the laminate with 5 different values of −0.01, −0.05, −0.1, −0.15, −0.2 mm for compression and 0.01, 0.05, 0.1, 0.3, 0.5 mm for tension. The FE shows that maximum force during impact increases with pre-stress in compression and decreases in tension. The contact time between impactor and laminate remains constant for pre-stress in tension and increases in compression. The impactor displacement during impact is lower for tension and higher for compression. Delamination area increases regardless whether in pre-stress tension or compression. The same trend of delamination shape evolution during impact is observed both for compression and tension; ellipse evolution in transverse or perpendicular direction to the prestress direction.
Study of kinetic and thermal decomposition from municipal solid waste pellets using model-fitting methods
Authors: Siregar S R H , Nursani D , Setyawan M I B , Surjosatyo A
Published: September 2021

Reaction rate model could be determined from kinetic characteristics. Kinetic and thermal decomposition of municipal solid waste (MSW) pellets, consist of organic material, plastic, paper and leaves, with tapioca flour as binder (0%, 3% and 6%) were studied in thermogravimetric analyzer from temperature 50°C to 800°C at heating rate 10 0C/min in N2 atmospheres. The kinetic parameter were determined by Model Fitting or Coats Redfern Methods with different kinetic reaction model. Results of this study have shown that MSW pellets in various binder has activation energy values 64.64 kJ/mol and 22.06 kJ/mol for 0%, 68.83 kJ/mol and 21.99 kJ/mol for 3%, and 69.29 kJ/mol and 22.62 kJ/mol for 6% at temperature ranges between 200°C-400°C and 400°C-500°C respectively in typical three dimensional diffusion (D3) mechanism kinetic reaction model.
Growth inhibition of tropical fungi by silver nanoparticles incorporated polyurethane coating
Authors: Said K M , Yunus W M Z W , Hidayah A , Ong K K , Shazwani A L N , Shakira M S N N , Nurnadia A
Published: September 2021

Polyurethanes (PUs) have been widely used in the coating industry due to their high flexibility and good UV resistance. Extensive formulations of PU coatings have been reported previously in the literature. Scientists nowadays improvise products whereby nanomaterial additives such as silver nanoparticles are incorporated to obtain antibacterial and antifungal properties. In this study, spherical shaped silver nanoparticles with an average size of 46 nm were added into polyol (polypropylene glycol) which was cross-linked with toluene isocyanate to obtain PU nanocomposite coating films. Characterizations of the coating film were carried out using Fourier transform infrared (FTIR) spectroscopy to observe the urethane linkage that was formed during the cross-linking and Field Emission Scanning Electron Microscope with Energy Dispersive X-Ray (FESEM-EDX) Spectroscopy analysis to determine size, shape and distribution of the nanoparticles. The antifungal activity of the nanocomposite coating was studied against Cladosporium cladosporiodes, Penicillium oxalicum and Aspergillus aculaetus. The results showed that the AgNPs-incorporated PU coating film has the ability to inhibit the tropical fungi growth.
Biodegradation of low-density polyethylene (LDPE) and starch – based plastic (SBP) by thermophiles Bacillus subtilis and Candida tropicalis
Authors: Zahari N Z , Abdullah S N , Tuah P M , Cleophas F N
Published: September 2021

This project was carried out to study the biodegradation of low-density polyethylene (LDPE) and starch-based plastics (SBP) by two types of thermophiles microorganisms namely B.subtilis and C. tropicalis in a lab scale method. A few specific objectives were set to identify the growth curve of both strains on LDPE and SBP films, changes in physical and chemical properties by weight loss, carbon dioxide (CO2) evolved, topography changes of plastics surfaces and the efficiency on biodegradation rate of LDPE and SBP. The results showed that after 49 days incubation period, the optimum growth of B. subtilis for both LDPE and SBP is at week 5 of incubation with 8.9 x 108 CFU/mL and 9.1 x 108 CFU/mL respectively. While for C. tropicalis the highest growth was recorded at week 4 of incubation with 9.6 x 108 for both LDPE and SBP. The weight loss reduction percentage of LDPE and SBP by C.tropicalis was 3.2% and 22.3% respectively while for B. subtilis the results recorded were 4.6% and 12.9% respectively. SEM analysis revealed that there are topography changes for LDPE with bubbling on surface while cracks and holes formed on SBP surface. The strum test used to identify CO2 evolved in SBP by C. tropicalis is 2.7 g/L which was 5-fold higher as compared to LDPE while in SBP by B. subtilis the results is 2.5 g/L which 5-fold higher compared to LDPE. Based on this study, it can be concluded that C. tropicalis have great potential in degrading SBP as compared to LDPE.