bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Human Epineural Conduit of Different Size Diameters on Efficacy of Nerve Regeneration and Functional Outcomes
Authors: Strojny Marcin Michal , Kozlowska Katarzyna , Brodowska Sonia , Różczka Klaudia , Siemionow Maria
Published: November 2022

Background Different types of nerve conduits are used to bridge peripheral nerve gaps when a tension-free repair is unattainable. To best support nerve regeneration, naturally occurring conduits have been tested. Since allografts offer an unlimited source of epineurium, we have developed human epineural conduit (hEC) as a novel technology to bridge nerve gaps. Considering acellular properties, and lack of immunogenic response, epineurium-derived conduits represent an attractive material, when compared with nerve allografts that require systemic immunosuppression. In this study, we introduce the hEC as a novel naturally occurring material applied for repair of nerve gaps after trauma.

Methods We tested the application of hEC created from human sciatic nerve in the restoration of 20 mm sciatic nerve defects in the nude rat model. Four experimental groups were studied: group 1: no repair control (n = 6), group 2: autograft control (n = 6), group 3: matched diameter hEC (n = 6), and group 4: large diameter hEC (n = 6). Functional tests of toe-spread and pin prick were performed at 1, 3, 6, 9, 12 weeks after repair. At 12 weeks, nerve samples were collected for immunostaining of Laminin B, S-100, glial fibrillary acidic protein (GFAP), nerve growth factor (NGF), vascular endothelial growth factor (VEGF), von Willebrand factor, and histomorphometric analysis of myelin thickness, axonal density, fiber diameter, and percentage of the myelinated nerve fibers. Muscle samples were gathered for gastrocnemius muscle index (GMI) and muscle fiber area ratio measurements.

Results Best functional recovery, as well as GMI, was revealed for the autograft group, and was comparable to the matched hEC group. Significant differences were revealed between matched and large hEC groups in expression of S100 (p = 0.0423), NGF (p = 0.269), VEGF (p = 0.0003) as well as in percentage of myelinated fibers (p < 0.001) and axonal density (p = 0.0003).

Conclusion We established the feasibility of hEC creation. The innovative method introduces an alternative technique to autograft repair of nerve defects.
Spectrum of Neurodegeneration with Brain Iron Accumulation with PLA2G6 Variation: A Report of Three Cases from Two Families
Authors: Puri Shivangi , Agrawal Ritesh K. , Singh Ankur , Verma Ashish , Mishra Arpita , Singh Ashok , Narayan Raghvendra , Mishra Om P.
Published: November 2022

Neurodegeneration with brain iron accumulation consists of disorders characterized by progressive neuronal degeneration, cognitive decline, brain iron accumulation in extrapyramidal system, dentate nucleus, and gray and white matters boundary. We present a case series of PLA2G6-associated neurodegeneration (PLAN), with definite PLA2G6 gene mutations in two cases and suspected in one case. Diagnosis was based on clinical presentations, brain magnetic resonance imaging (MRI) findings, and detection of PLA2G6 mutations. Case 1: An 8-year-old boy presented with weakness of lower limbs, subnormal intelligence, scanning speech, spasticity, dysdiadochokinesia, pendular knee jerk, and extensor plantar reflex. MRI of the brain showed diffuse cerebellar atrophy and white matter T2 hyperintensity with iron deposition in bilateral globus pallidi. Case 2: Elder sister of Case 1, who developed ataxia at the age of 6 years and became bedridden at 14 years. She had nocturnal enuresis, seizures, cervical dystonia, dysphagia, and died at 23 years of age. MRI showed cerebral and cerebellar atrophies and iron deposition in basal ganglia and substantia nigra. Case 3 had infantile onset with quadriparesis, optic atrophy, developmental delay, cerebral and cerebellar atrophies, and brain iron accumulation in basal ganglia. Case 1 revealed two heterozygous mutations of PLA2G6 gene in exons 16 (c.2264G > A, p. Arg755Gln) and 12 (c.1637G > A, p. Arg546Gln), classified as likely pathogenic. Elder sister (Case 2) could not be tested for this mutation. Case 3 showed homozygous silent splice site point variation in exon 7 (c.1077 G > A; p. Ser 359 Ser) of PLA2G6 gene. Thus, in patients presenting with neurodegeneration and imaging findings of brain iron accumulation, diagnosis can be established by PLA2G6 gene mutation analysis.
Improving the study of atoms under pressure
Authors: Lim Alane
Published: November 2022

Instrumentation to probe muon rotation and relaxation under hydrostatic pressure proposed.
Iron nanoparticles boost magnetocaloric effect
Authors: Thompson Avery
Published: November 2022

Common materials could result in efficient, environmentally friendly refrigeration cycles
Ultraintense few-cycle infrared laser generation by fast-extending plasma grating
Authors: Li Zhaoli , Zuo Yanlei , Zeng Xiaoming , Wu Zhaohui , Wang Xiaodong , Wang Xiao , Mu Jie , Hu Bilong
Published: November 2022

Ultraintense short-period infrared laser pulses play an important role in frontier scientific research, but their power is quite low when generated using current technology. This paper demonstrates a scheme for generating an ultraintense few-cycle infrared pulse by directly compressing a long infrared pulse. In this scheme, an infrared picosecond-to-nanosecond laser pulse counterpropagates with a rapidly extending plasma grating that is created by ionizing an undulated gas by a short laser pulse, and the infrared laser pulse is reflected by the rapidly extending plasma grating. Because of the high expansion velocity of the latter, the infrared laser pulse is compressed in the reflection process. One- and two-dimensional particle-in-cell simulations show that by this method, a pulse with a duration of tens of picoseconds in the mid- to far-infrared range can be compressed to a few cycles with an efficiency exceeding 60%, thereby making ultraintense few-cycle infrared pulses possible.
Photo-induced charge transfer in composition-tuned halide perovskite nanocrystals with quinone and its impact on conduction current
Authors: Mishra Leepsa , Panigrahi Aradhana , Dubey Priyanka , Sarangi Manas Kumar
Published: November 2022

A facile interfacial charge transfer (CT) with a reduced inter-layer energy band regulates the charge transport mechanism in any optoelectronic device. The enhancement in semiconductor-based device performance often demands improved CT dynamics and collection of free carriers with reduced charge recombination. In this work, we present a detailed inspection of the photo-induced CT between inorganic lead halide perovskite nanocrystals (PNCs) with varied compositions and their consequence on the charge transport process. The superior CT rate in mixed halide CsPbBr2Cl PNCs with naphthoquinone (NPQ) is revealed when compared with the parent CsPbBr3 PNCs and its anion-exchanged counterpart CsPbCl3. The glimpses of hole transfer contribution along with electron transfer are detected for CsPbBr2Cl with superior CT efficiency. The enhanced conduction current after the insertion of NPQ into the PNCs with a reduced hysteresis suggests an improved charge transport in the fabricated device compared to the pristine PNCs. These findings can contribute to a better understanding of multiple ways of engineering optoelectronic devices to boost performance and efficiencies and the concurrent role of the CT process in the conduction mechanism.
Numerical simulation of bubble rising in porous media using lattice Boltzmann method
Authors: Lou Qin , Yan Yu , Xu Hongtao
Published: November 2022

Rising bubble systems in porous media exist in a variety of industrial processes. However, the flow characteristics of the issue are not well understood. In this work, the rising of bubble/bubbles through two types of porous structures, namely, in-line structured pore and staggered structured pore, are studied using a large density ratio lattice Boltzmann model. The effects of Eötvös number, pore shape, viscosity ratio, initial bubble number, and arrangement manner of the initial bubbles on the bubble deformation, bubble rising velocity, residual bubble mass, bubble perimeter, and the number of bubble breakups are investigated. It is found that as the Eötvös number increases, the bubbles are more easily broken during the process of passing through the porous media, the shapes of the sub-bubbles deviate from the original ones more and more, the bubble perimeter increases, and the difference between the bubble dynamics obtained by the in-line and staggered porous media decreases. Compared to the results of circular and rectangular pores, the bubble rising through the diamondoid pore has a more considerable deformation, which causes a slower rising speed. Furthermore, in the case that two bubbles are originally placed under the porous medium, the bubble deformation is greater and the bubble fracture times increase if the initial bubbles are aligned vertically. The findings of this work can contribute to the understanding of gas–liquid two-phase flow in porous media.
THz detection and amplification using plasmonic field effect transistors driven by DC drain currents
Authors: Zhang Yuhui , Shur Michael
Published: November 2022

We report on the numerical and theoretical results of sub-THz and THz detection by a current-driven InGaAs/GaAs plasmonic field-effect transistor (TeraFET). New equations are developed to account for the channel length dependence of the drain voltage and saturation current. Numerical simulation results demonstrate that the effect of drain bias current on the source-to-drain response voltage (dU) varies with the device channel length. In a long-channel TeraFET where plasmonic oscillations cannot reach the drain, dU is always positive and rises rapidly with increasing drain current. For a short device in which plasmonic oscillations reach the drain, the current-induced nonuniform electric field leads to a negative response, agreeing with previous observations. At negative dU, the amplitude of the small-signal voltage at the drain side becomes larger than that at the source side. Thus, the device effectively serves as a THz amplifier in this condition. Under the resonant mode, the negative response can be further amplified near the resonant peaks. A new expression of dU is proposed to account for this resonant effect. Based on those expressions, a current-driven TeraFET spectrometer is proposed. The ease of implementation and simplified calibration procedures make it competitive or superior compared with other TeraFET-based spectrometers.
Mitochondrial nucleoid trafficking regulated by the inner-membrane AAA-ATPase ATAD3A modulates respiratory complex formation
Authors: Ishihara Takaya , Ban-Ishihara Reiko , Ota Azusa , Ishihara Naotada
Published: November 2022

Mitochondria have their own DNA (mtDNA), which encodes essential respiratory subunits. Under live imaging, mitochondrial nucleoids, composed of several copies of mtDNA and DNA-binding proteins, such as mitochondrial transcription factor A (TFAM), actively move inside mitochondria and change the morphology, in concert with mitochondrial membrane fission. Here we found the mitochondrial inner membrane-anchored AAA-ATPase protein ATAD3A mediates the nucleoid dynamics. Its ATPase domain exposed to the matrix binds directly to TFAM and mediates nucleoid trafficking along mitochondria by ATP hydrolysis. Nucleoid trafficking also required ATAD3A oligomerization via an interaction between the coiled-coil domains in intermembrane space. In ATAD3A deficiency, impaired nucleoid trafficking repressed the clustered and enlarged nucleoids observed in mitochondrial fission-deficient cells resulted in dispersed distribution of small nucleoids observed throughout the mitochondrial network, and this enhanced respiratory complex formation. Thus, mitochondrial fission and nucleoid trafficking cooperatively determine the size, number, and distribution of nucleoids in mitochondrial network, which should modulate respiratory complex formation.
Mitochondrial dysfunction compromises ciliary homeostasis in astrocytes
Authors: Ignatenko Olesia , Malinen Satu , Rybas Sofiia , Vihinen Helena , Nikkanen Joni , Kononov Aleksander , Jokitalo Eija S. , Ince-Dunn Gulayse , Suomalainen Anu
Published: November 2022

Astrocytes, often considered as secondary responders to neurodegeneration, are emerging as primary drivers of brain disease. Here we show that mitochondrial DNA depletion in astrocytes affects their primary cilium, the signaling organelle of a cell. The progressive oxidative phosphorylation deficiency in astrocytes induces FOXJ1 and RFX transcription factors, known as master regulators of motile ciliogenesis. Consequently, a robust gene expression program involving motile cilia components and multiciliated cell differentiation factors are induced. While the affected astrocytes still retain a single cilium, these organelles elongate and become remarkably distorted. The data suggest that chronic activation of the mitochondrial integrated stress response (ISRmt) in astrocytes drives anabolic metabolism and promotes ciliary elongation. Collectively, our evidence indicates that an active signaling axis involving mitochondria and primary cilia exists and that ciliary signaling is part of ISRmt in astrocytes. We propose that metabolic ciliopathy is a novel pathomechanism for mitochondria-related neurodegenerative diseases.
cAMP-PKA signaling modulates the automaticity of human iPSC-derived cardiomyocytes
Authors: Mazgaoker Savyon , Weiser-Bitoun Ido , Brosh Inbar , Binah Ofer , Yaniv Yael
Published: November 2022

Human-induced pluripotent stem cell–derived cardiomyocytes (hiPSC-CMs) have been used to screen and characterize drugs and to reveal mechanisms underlying cardiac diseases. However, before hiPSC-CMs can be used as a reliable experimental model, the physiological mechanisms underlying their normal function should be further explored. Accordingly, a major feature of hiPSC-CMs is automaticity, which is regulated by both Ca2+ and membrane clocks. To investigate the mechanisms coupling these clocks, we tested three hypotheses: (1) normal automaticity of spontaneously beating hiPSC-CMs is regulated by local Ca2+ releases (LCRs) and cAMP/PKA-dependent coupling of Ca2+ clock to M clock; (2) the LCR period indicates the level of crosstalk within the coupled-clock system; and (3) perturbing the activity of even one clock can lead to hiPSC-CM–altered automaticity due to diminished crosstalk within the coupled-clock system. By measuring the local and global Ca2+ transients, we found that the LCRs properties are correlated with the spontaneous beat interval. Changes in cAMP-dependent coupling of the Ca2+ and M clocks, caused by a pharmacological intervention that either activates the β-adrenergic or cholinergic receptor or upregulates/downregulates PKA signaling, affected LCR properties, which in turn altered hiPSC-CMs automaticity. Clocks’ uncoupling by attenuating the pacemaker current If or the sarcoplasmic reticulum Ca2+ kinetics, decreased hiPSC-CMs beating rate, and prolonged the LCR period. Finally, LCR characteristics of spontaneously beating (at comparable rates) hiPSC-CMs and rabbit SAN are similar. In conclusion, hiPSC-CM automaticity is controlled by the coupled-clock system whose function is mediated by Ca2+-cAMP-PKA signaling.
Regularizing dual-frame generalized harmonic gauge at null infinity
Authors: Duarte Miguel , C Feng Justin , Gasperín Edgar , Hilditch David
Published: November 2022

The dual-frame formalism leads to an approach to extend numerical relativity simulations in generalized harmonic gauge (GHG) all the way to null infinity. A major setback is that without care, even simple choices of initial data give rise to logarithmically divergent terms that would result in irregular variables and equations on the compactified domain, which would in turn prevent accurate numerical approximation. It has been shown, however, that a suitable choice of gauge and constraint addition can be used to prevent their appearance. Presently we give a first order symmetric hyperbolic reduction of general relativity in GHG on compactified hyperboloidal slices that exploits this knowledge and eradicates these log-terms at leading orders. Because of their effect on the asymptotic solution space, specific formally singular terms are systematically chosen to remain. Such formally singular terms have been successfully treated numerically in toy models and result in a formulation with the desirable property that unphysical radiation content near infinity is suppressed.
Gauge-fixing and spacetime reconstruction in the Hamiltonian theory of cosmological perturbations
Authors: Boldrin Alice , Małkiewicz Przemysław
Published: November 2022

We develop a complete Hamiltonian approach to the theory of perturbations around any spatially homogeneous spacetime. We employ the Dirac method for constrained systems which is well-suited to cosmological perturbations. We refine the method via the so-called Kuchař parametrization of the kinematical phase space. We separate the gauge-invariant dynamics of the three-surfaces from the three-surface deformations induced by linear coordinate transformations. The canonical group of the three-surface deformations and the complete space of gauge-fixing conditions are explicit in our approach. We introduce a frame in the space of gauge-fixing conditions and use it to considerably simplify the prescription for gauge-fixing, partial gauge-fixing and spacetime reconstruction. Finally, we illustrate our approach by considering the perturbed Kasner Universe, for which we discuss two kinds of gauges that correspond respectively to the Coulomb-like and the Lorenz-like gauge in electrodynamics.
Out-of-plane and in-plane magnetic phases of a FeGe slab detected by dynamic cantilever magnetometry
Authors: Xu Feng , Wang Ning , Zhu Wanli , Zhang ChangJin , Tian Mingliang , Xue Fei
Published: November 2022

Using dynamic cantilever magnetometry (DCM), the magnetic phases in
H
-out-of-plane and
H
-in-plane configurations of a FeGe slab were investigated. We recorded magnetic field-dependent frequency shifts with static temperature (f
-H
measurements) and temperature-dependent frequency shifts with static magnetic field (f-
T
measurements). Based on these data, we constructed the
H
–
T
phase diagrams in both configurations. Skyrmion phase (SkX) can be recognized in
H
-out-of-plane configuration. While no signature of SkX can be recognized in
H
-in-plane configuration. Meanwhile, the critical magnetic field for the transition from conical phase to field-polarized phase in
H
-out-of-plane configuration is higher than in
H
-in-plane configuration. We attribute these two differences to signal-to-noise ratio and demagnetizing field in two configurations, respectively. This work demonstrated the ability of DCM to probe magnetizations of thick or tilted magnetic films, which are difficult to measure using Lorentz transmission electron microscopy or vibrating sample microscopy.
Controllable growth of wafer-scale monolayer transition metal dichalcogenides ternary alloys with tunable band gap
Authors: Li Rongsheng , Yu Junyao , Yao Bing , Huang Xianlei , Fu Zihao , Zhou Zhenjia , Yuan Guowen , Xu Jie , Gao Libo
Published: November 2022

The tuning of band gap is very important for the application of two-dimensional (2D) materials in optoelectronic devices. Alloying of 2D transition metal dichalcogenides (TMDCs) is an important way to tune the wide band gap. In this study, we report a multi-step vapor deposition method to grow monolayer TMDC ternary alloy films with wafer scale, including Mo1−x
W
x
S2, Mo1−x
W
x
Se2 and MoS2x
Se2(1−x), which are accurately controllable in the elemental proportion (x is from 0 to 1). The band gap of the three 2D ternary alloy materials are continuously tuned for the whole range of metal and chalcogen compositions. The metal compositions are controlled by the as-deposited thickness. Raman, photoluminescence, elemental maps and TEM show the high spatial homogeneity in the compositions and optical properties across the whole wafer. The band gap can be continuously tuned from 1.86 to 1.99 eV for Mo1−x
W
x
S2, 1.56 to 1.65 eV for Mo1−x
W
x
Se2, 1.56 to 1.86 eV for MoS2x
Se2(1−x). Electrical transport measurements indicate that Mo1−x
W
x
S2 and MoS2x
Se2(1−x) monolayers show n-type semiconductor behaviors, and the carrier types of Mo1−x
W
x
Se2 can be tuned as n-type, bipolar and p-type. Moreover, this control process can be easily generalized to other 2D alloy films, even to quaternary or multi-element alloy materials. Our study presents a promising route for the preparation of large-scale homogeneous monolayer TMDC alloys and the application for future functional devices.
Ensemble learning for glioma patients overall survival prediction using pre-operative MRIs
Authors: Yang Zi , Chen Mingli , Kazemimoghadam Mahdieh , Ma Lin , Stojadinovic Strahinja , Wardak Zabi , Timmerman Robert , Dan Tu , Lu Weiguo , Gu Xuejun
Published: November 2022

Objective: Gliomas are the most common primary brain tumors. Approximately 70% of the glioma patients diagnosed with glioblastoma have an averaged overall survival (OS) of only ∼16 months. Early survival prediction is essential for treatment decision-making in glioma patients. Here we proposed an ensemble learning approach to predict the post-operative OS of glioma patients using only pre-operative MRIs. Approach: Our dataset was from the Medical Image Computing and Computer Assisted Intervention Brain Tumor Segmentation challenge 2020, which consists of multimodal pre-operative MRI scans of 235 glioma patients with survival days recorded. The backbone of our approach was a Siamese network consisting of twinned ResNet-based feature extractors followed by a 3-layer classifier. During training, the feature extractors explored traits of intra and inter-class by minimizing contrastive loss of randomly paired 2D pre-operative MRIs, and the classifier utilized the extracted features to generate labels with cost defined by cross-entropy loss. During testing, the extracted features were also utilized to define distance between the test sample and the reference composed of training data, to generate an additional predictor via K-NN classification. The final label was the ensemble classification from both the Siamese model and the K-NN model. Main results: Our approach classifies the glioma patients into 3 OS classes: long-survivors (>15 months), mid-survivors (between 10 and 15 months) and short-survivors (<10 months). The performance is assessed by the accuracy (ACC) and the area under the curve (AUC) of 3-class classification. The final result achieved an ACC of 65.22% and AUC of 0.81. Significance: Our Siamese network based ensemble learning approach demonstrated promising ability in mining discriminative features with minimal manual processing and generalization requirement. This prediction strategy can be potentially applied to assist timely clinical decision-making.
Overview of L- to H-mode transition experiments at ASDEX Upgrade
Authors: Plank U , McDermott R M , Birkenmeier G , Bonanomi N , Cavedon M , Conway G D , Eich T , Griener M , Grover O , Schneider P A , Willensdorfer M
Published: November 2022

This paper presents an overview of results from L–H transition experiments that were performed at ASDEX Upgrade (AUG) with the aim of identifying the underlying mechanisms leading to H-mode confinement. With a broad variety of experiments and new diagnostic techniques, as well as modeling efforts, AUG has contributed substantially to improving our understanding of the L–H transition over the past years. In this review, the important roles of the ion heat channel and the edge radial electric field (E

r
) in the L–H transition physics are brought into context with known dependencies of the H-mode power threshold (

P

L
H

), such as the impact of wall material, magnetic perturbations, and the magnetic configuration. Furthermore, experimental and theoretical results obtained at AUG on the L-mode edge turbulence are connected to the mean-field E

r
and its related shear flow. This led to a deeper understanding of the I-phase plasma regime, has resolved the so-called isotope effect of

P

L
H

, and led to the development of a semi-analytical model that can describe AUG’s experimental observations of the L–H transition together with the L- and H-mode density limits.
Investigation of the compatibility of pellet fueling with ELM-free H-mode plasmas in EAST tokamak
Authors: Hou Jilei , Zuo Guizhong , Xu Liqing , Hu Jiansheng , Chen Yue , Yuan Xiaolin , Chu Yuqi , Wu Mingfu , Zhong Fubin , Li Pan , Wang Shouxin , Zhao Hailin , Zhou Chu , Ye Yang , Zhao Weikuan , Zhang Ling , Lu Dian , Yang Xiuda , Li Jiangang
Published: November 2022

Experiments on pellet fueling have been carried out in edge localized mode (ELM)-free high-confinement mode (H-mode) plasmas with q
95 ∼ 6 in the EAST tokamak. Cryogenic deuterium pellets were injected into the ELM-free plasmas at a frequency of 10 or 5 Hz from ∼45 cm above the mid-plane on the low-field side. It is found that the ELM-free H-mode plasmas are still sustained even if both the edge and core plasma are impacted by the pellet injections (PIs). Several small ELMs would appear and the edge coherent mode accompanying the ELM-free phase fades or even disappears just after the pellet events, but the plasma would rapidly recover to the ELM-free state. Although the ELMing phase is very short, it may be an issue that still needs to be resolved in the future. Meanwhile, the 3/2 tearing mode often appearing in ELM-free discharges would be stabilized by the PIs, and the high-Z impurity concentration would be reduced during the PIs. All these results will be meaningful to International Thermonuclear Experimental Reactor and future fusion reactors.
(Ba1−x
Na
x
)F(Zn1−x
Mnx)Sb: A novel fluoride-antimonide magnetic semiconductor with decoupled charge and spin doping
Authors: Zhao Xueqin , Dong Jinou , Fu Licheng , Gu Yilun , Zhang Rufei , Yang Qiaolin , Xie Lingfeng , Tang Yinsong , Ning Fanlong
Published: November 2022

We report the successful synthesis and characterization of a novel 1111-type magnetic semiconductor (Ba1−x
Na
x
)F(Zn1−x
Mn
x
)Sb (0.05 ≤ x ≤ 0.175) with tetragonal ZrSiCuAs-type structure, which is isostructural to the layered iron-based superconductor La(O,F)FeAs. Na substitutions for Ba and Mn substitutions for Zn introduce carriers and local magnetic moments, respectively. Ferromagnetic interaction is formed when Na and Mn are codoped, demonstrating that local magnetic moments are mediated by carriers. Iso-thermal magnetization shows that the coercive field is as large as ~ 12 000 Oe, which is also reflected in the large split between the temperature-dependent magnetization in zero-field-cooling and field-cooling condition. AC susceptibility under zero field demonstrates that samples evolve into spin-glass state below spin freezing temperature T
f. The measurements of temperature-dependent resistivity indicate that (Ba1−x
Na
x
)F(Zn1−x
Mn
x
)Sb exhibits semiconducting behaviour.
High-power microwaves response characteristics of silicon and GaAs solar cells
Authors: Meng Xiangrui , Chai Changchun , Li Fuxing , Sun Yi , Yang Yintang
Published: November 2022

The high-power microwave (HPM) effect heats solar cells, which is an important component of a satellite. This creates a serious reliability problem and affects the normal operation of a satellite. In this paper, the different HPM response characteristics of two kinds of solar cells are comparatively researched by simulation. The results show that there are similarities and differences in hot spot distribution and damage mechanisms between both kinds of solar cell, which are related to the amplitude of HPM. In addition, the duty cycle of repetition frequency contributes more to the temperature accumulation of the solar cells than the carrier frequency. These results will help future research of damage assessment technology, reliability enhancement and the selection of materials for solar cells.
Clarifying the atomic origin of electron killers in β-Ga2O3 from the first-principles study of electron capture rates
Authors: Suo Zhaojun , Wang Linwang , Li Shushen , Luo Junwei
Published: November 2022

The emerging wide bandgap semiconductor

-Ga2O3 has attracted great interest due to its promising applications for high-power electronic devices and solar-blind ultraviolet photodetectors. Deep-level defects in

-Ga2O3 have been intensively studied towards improving device performance. Deep-level signatures E
1, E
2, and E
3 with energy positions of 0.55–0.63, 0.74–0.81, and 1.01–1.10 eV below the conduction band minimum have frequently been observed and extensively investigated, but their atomic origins are still under debate. In this work, we attempt to clarify these deep-level signatures from the comparison of theoretically predicted electron capture cross-sections of suggested candidates, Ti and Fe substituting Ga on a tetrahedral site (TiGaI and FeGaI) and an octahedral site (TiGaII and FeGaII), to experimentally measured results. The first-principles approach predicted electron capture cross-sections of TiGaI and TiGaII defects are 8.56 × 10–14 and 2.97 × 10–13 cm2, in good agreement with the experimental values of E
1 and E
3 centers, respectively. We, therefore, confirmed that E
1 and E
3 centers are indeed associated with TiGaI and TiGaII defects, respectively. Whereas the predicted electron capture cross-sections of FeGa defect are two orders of magnitude larger than the experimental value of the E
2, indicating E
2 may have other origins like CGa and Gai, rather than common believed FeGa.
Bulk GaN-based SAW resonators with high quality factors for wireless temperature sensor
Authors: Lv Hongrui , Shi Xianglong , Ai Yujie , Liu Zhe , Lin Defeng , Jia Lifang , Cheng Zhe , Yang Jie , Zhang Yun
Published: November 2022

Surface acoustic wave (SAW) resonator with outstanding quality factors of 4829/6775 at the resonant/anti-resonant frequencies has been demonstrated on C-doped semi-insulating bulk GaN. The impact of device parameters including aspect ratio of length to width of resonators, number of interdigital transducers, and acoustic propagation direction on resonator performance have been studied. For the first time, we demonstrate wireless temperature sensing from 21.6 to 120 °C with a stable temperature coefficient of frequency of –24.3 ppm/°C on bulk GaN-based SAW resonators.
The impact of disposable mask waste pollution in peat soil
Authors: Mentari Alvi Eka , Khoironi Adian , Hadiyanto
Published: November 2022

The abundance of plastic waste in Indonesia has increased due to the contribution of disposable masks waste during the COVID-19 pandemic. The improper waste management causes the habit of dumping waste in the soil system to still frequently occur. The secondary microplastics from disposable mask waste has the potential to damage soil quality and soil capillary water. Therefore, this study was conducted with the aim of understanding the effects of disposable mask waste in peat soil. The research was conducted by setting up 3 reactors containing peat soil with disposable mask waste buried in it and some plants being grown on it. For 45 days, observations and samples were taken, both filtrate water and soil for analysis. The analysis results showed significant changes in soil properties with changes in the concentration of inorganic matter, organic matter, porosity, bulk density, and water content. Further research needs to be done to see the effects of disposable mask waste in the soil system in real conditions where several confounding variables cannot be controlled.
Upcycle strategy on tree branches to improve eco-efficiency towards a circular economy using life cycle assessment
Authors: Hartini Sri , Rumita Rani , Huda Muhammad Hafidz Al
Published: November 2022

A circular economy (CE) is considered capable of being a solution to reduce the use of natural resources and reduce waste without harm. A circular economy system uses products and materials at maximum value and function. Various strategies were developed for this purpose. However, these efforts often require additional energy and materials to create more valuable products. Does the increase in value-creation mean more than the energy consumption and materials to make it happen? This study conducted a study of efforts to increase wood branch waste, which is usually only used for firewood, which is processed into hanger products with an upcycle strategy. This study uses the eco-efficiency method to determine the increase in value in the economic aspect compared to the environmental impact it causes. The cost of environmental impact is calculated using a life cycle assessment with Simapro software. The findings from this study are that upcycle efforts can increase product eco-efficiency. The eco-efficiency index (EEI) of hanger products is 4.512 and the EEI of firewood is 3.816.
Quality of surface water due to sand mining activity: a case study from the Progo River, Daerah Istimewa Yogyakarta Province, Indonesia
Authors: Trisnaning P T , Zamroni A , Sugarbo O , Prasetya H N E , Sagala S T , Hardiansyah M Y
Published: November 2022

Due to sand mining, the study objective is to assess water quality in the Progo River, Daerah Istimewa Yogyakarta Province. It is beneficial to evaluate the physicochemical parameters of the Progo River and to appraise water quality for drinking purposes based on the Indonesia Minister of Health regulation No: 492/ Menkes/Per/IV/2010. The physicochemical parameters used in this study included pH, EC, TDS, DO, SO42-, NO3-, and PO43-. The pH decrease is thought to be due to the opening of sand deposits around the river so that minerals such as feldspar, hornblende, and quartz dissolve and mix in water. The TDS increase was estimated due to the increase in the riverbed and bank erosion associated with sand mining at the mining and downstream sites. In addition, sand mining activities affect higher DO because bubbles aerate flowing water in fast-moving water as it churns over rocks and falls into hundreds of tiny waterfalls. Meanwhile, other parameters, such as EC, SO42-, NO3-, and PO43-are influenced by natural factors, such as seawater mixing and soil erosion. Almost all parameters are permissible for drinking purposes, except for Station 3 at the downstream which TDS and SO42-- values are.
An environmental impact assessment of geothermal tourism: A case study of Awit Sinar Alam Darajat, Garut-Indonesia
Authors: Munfarida I , Nilandita W , Auvaria S W
Published: November 2022

Geothermal as one of the potential environmental services in conservation areas is increasingly being taken into account. According to the Government Regulation No. 25 of 2021 on the Implementation of the Energy and Mineral Resources Sector, geothermal can be used directly or indirectly. The geothermal tourism of Awit Sinar Alam Darajat is an example of the direct utilization of geothermal energy for tourism. This study aims to assess the impact of geothermal tourism on the environment and develop environmental management and monitoring. The analysis was carried out utilizing a qualitative and quantitative methods approach. Data were collected from secondary data and analyzed to develop environmental management and monitoring. The result showed that the environmental impact of geothermal tourism includes the change of land use, the decrease in geothermal quantity and the generation of quality, and solid waste. We recommend environmental management, such as setting the minimum standard for the Green Base Coefficient of 70%, geothermal conservation, providing the geothermal treatment plant, and solid waste management. Environmental monitoring should be applied when calculating the Green Base Coefficient and the quantity and quality of geothermal and solid waste generation to achieve the standard.
Learning from Contextual Material Practices in Architecture: Exploring Nature-Based Materials in Indonesia and Thailand
Authors: Paramita Kristanti Dewi , Atmodiwirjo Paramita , Sinuraibhan Soranart
Published: November 2022

This paper outlines pedagogical strategies in architectural design studio to construct awareness of local material practices towards architecture which rooted in its environmental context. Current architectural discourse perceives the notion of material as something separate from its environmental context. Through a joint design workshop conducted between Universitas Indonesia and Kasetsart University, this paper explores existing material practices happening in the local context of Indonesia and Thailand and how it informs material-driven architectural programming. In a group, students were tasked to reconstruct their understanding of materiality, and develop collections of material practices from both countries which revealed various local knowledge, spatiality, and environmental understanding. The workshop then demonstrates important lessons in the ways material triggers programmatic relation between architecture and its surrounding environment. Among these relations are shown in the way nature-driven community events triggers specific material craftsmanship, the connection between material utilisation in the community’s spaces and natural cycles of seasons, and the interdependence between material practices and different geographical positions. Strategies in reconstructing the material knowledge towards material-based programming cross-culturally enables students to reflect on the unique material possibilities, as well as build awareness of local community strategies toward sustainable and material-driven architecture.
A comparison of rap-tourism method and multi attribute aggregation in sustainability assessment of tourist destination
Authors: Putri A A A , Purwaningsih R , Hartini S
Published: November 2022

The development of the tourism industry causes emergence of positive and negative impacts on tourist destinations. The development of the tourism industry has led the government to implement the concept of sustainable tourism. To assist the implementation of sustainable tourism, it is important to know the sustainability status of tourist destinations. The measuring tools used for calculated sustainability index values and identification of sensitive indicators. The method used must be easy to use and provide accurate results. This study compares between the rap-tourism and the multi attribute aggregation method. The aim is to choose which method better in measuring sustainability status when the objects of measurement are a lot of tourist destinations, better means easy to use and represent indicators condition briefly. The results of the assessment using both methods obtain the same sustainability status but there are differences in the sustainability index value. These two methods also use different approaches in determining sensitive indicators that should be improved to increase the sustainability index of tourist destinations.
Tracing flow directions of the Pentung Allogenic River in Gunungsewu Karst Area, Gunungkidul, using artificial tracer test
Authors: Cahyadi A , Adji T N , Haryono E , Widyastuti M , Agniy R F
Published: November 2022

Previous studies in the Gunungsewu Karst Area categorized the Pentung Allogenic River catchment that drains to the Sawah Ombo Pond as the upper part of the Bribin Karst Drainage Basin (KDB). However, more detailed results from natural isotope studies after 2010 have provided reasons to postulate that the groundwater does not flow from the catchment to Bribin KDB. Therefore, the research aimed to trace the direction of Pentung’s groundwater flows in Gunungsewu’s karstic hydrogeological system. To achieve this, an artificial tracer test was used. There were two fluorescent dye injection namely uranine and tinopal. The results confirmed that the allogenic river’s catchment supplied groundwater to Beton KDB instead of Bribin KDB. While the artificial tracers were not detected in the water at Gilap Cave and Bribin Underground River, they appeared in Jomblangan Cave and Sriti Spring, parts of Beton KDB.
The Seafarer’s Level of Understanding on Ballast Water Management Convention
Authors: el Husna Iksiroh , Wahdiana Dian , Nasri  , Wijinurhayati Anissofiah Azise , Putri Widya
Published: November 2022

Due to practical and economic considerations, the sea transportation is increasingly in demand as a means of transporting world trade activities. The ships without cargo will use ballast water as a stabilizer. Ballast water is often carried by various foreign microorganisms that harm the ecosystem. IMO promulgated the 8 September 2017 Ballast Water Management (BWM) Convention to prevent the spread of harmful pathogenic microbes. This study aims to determine the understanding of seafarers of the provisions of BWM. The descriptive-analytical method used a cross-sectional approach using questionnaires and in-depth interviews. The sample consisted of 47 seafarers; 3 samples were removed because they did not meet the requirements. The results show that most respondents do not understand the provisions of BWM correctly. None of the respondents knew when the BWM was enacted. In some questions, less than 10% of the answers are correct. However, on the importance of handling ballast water, there is 43.18% answered correctly, meaning that there is a concern for respondents about the dangers of it, and it is essential to address it immediately. We suggest that socialization among seafarers can be through seminars or special training on ballast water.
Study of environmental carrying capacity in Pemalang Regency
Authors: Kahfi A H , Samadikun B P , Sarminingsih A
Published: November 2022

To achieve sustainable development goals, the environment is one of the aspects that is taken into account. Environmental problems such as population growth, changes in land use, climate change lead to a decrease in the carrying capacity of the environment for the community. Pemalang Regency is included in the administrative area of Central Java Province, Indonesia. This writing aims to determine the extent of the Environmental Carrying Capacity in Pemalang Regency in the sector of water resources and land availability, as well as the resilience of the Environmental Carrying Capacity to the projected population growth in Pemalang Regency. This study found that the water resources sector has deficit since the first year of projected population growth in 2020. While in the land availability sector, it was found that the surplus condition occurred in the first year of projected population growth from 2020 to 2022
Business Model Innovation: Lesson Learned From EV Ecosystem In Indonesia
Authors: Amir M T , Prabawani B
Published: November 2022

Although relatively developed in advanced countries, the electric vehicle (EV) industry in Indonesia is still in the early stages of development. Designing a business model with an ecosystem perspective is critical for relevant stakeholders because there are still many uncertainties to be faced, including the unclear structure of the industry. This study examines the case of how an e-bus company creates a business model by taking into account the important role of stakeholders in their ecosystem. Top management of a manufacturing company and its parent company were in-depth interviewed. The roles and critical challenges of regulators, battery manufacturers, and assembly plants are explored. The practice of creating business models will be compared with applying business models in the literature. The discussion will focus on the need of the focal company in creating value through approaching regulators, collaborating with battery manufacturer, and creating communication as the innovations. The findings in this study are expected to be input for e-bus business actors for sustaining the development stage and stakeholders in the existing ecosystem, including the government or regulators.
Adaptation Strategies of Grobogan Regency Farmers in Face of Climate Change
Authors: Esariti L , Nida R S , Handayani W , Rudiarto I
Published: November 2022

The advent of climate change in Grobogan Regency is marked by the lengthy dry season, prevalence of rat attacks and changes in the growing season due to weather instability. This article aims to explore adaptation strategies for farmers in dealing with the problem of declining crop productivity due to climate change. Based on observations, expert interviews, and questionnaires delivered to the population, it was concluded that the strategies implemented among the farmers were aimed at maintaining livelihoods. The survey results indicated that there were different agricultural patterns in the western and eastern parts of Grobogan Regency and, as such, the farmers employed different adaptation strategies respective to their locations. In West Grobogan, focus was put on managing farmland with irrigation sourced from the Glapan dam. Meanwhile, in East Grobogan, rainfed agriculture, particularly for corn and soybean commodities, was customary. Analysis of the exploratory research suggested that 2 adaptation strategies are implemented by the farmers. First, the farmers commonly migrate and seek supplementary jobs to ensure income stability. Second, the farmers use planting techniques and seeds with superior quality and short harvest periods, which they invented.
Comparative study of upconversion and photoacoustic measurements of Er3+/Yb3+ doped La2O3 phosphor under 980 nm
Authors: Sarkar Minarul I , Mishra Neeraj Kumar , Kumar Kaushal
Published: November 2022

The Er3+/Yb3+doped La2O3 phosphor samples were synthesized by the combustion method and then photoluminescence and photoacoustic spectroscopic studies were done. Prepared samples were annealed at 800 °C, 1000 °C and 1300 °C and all samples were found in pure hexagonal phase as confirmed by XRD analysis. From FE-SEM images it is found that particle size increases with increase in annealing temperature. The frequency upconversion emission spectra of samples were recorded by exciting the sample with 980 nm diode laser and maximum emission intensity is obtained for the sample annealed at 1000 °C for 2 h. A photoacoustic cell was designed and wavelength dependent photoacoustic spectra were measured. The effect of sample storage time on radiative and non-radiative emission properties of sample was checked by measuring upconversion emission and photoacoustic spectra, simultaneously. It is observed that the emission intensity and photoacoustic signal both decreases with time. The maximum photoacoustic signal is obtained around 974 nm wavelength and it indicates its potential for photo-thermal therapy using infrared excitation.
A study of the processing and characterization of RSM optimized YSZ-Inconel625 wear-resistant TIG weld cladding
Authors: Kamboj Neeraj , Thakur Lalit
Published: November 2022

The present investigation focuses on developing a wear-resistant Yttria Stabilized Zirconia (YSZ) reinforced Inconel-625 (IN625) based TIG weld composite cladding on the AISI 304 stainless steel substrate. TIG welding current, scanning speed, standoff distance and YSZ reinforcement % were the primary input process parameters for cladding deposition. For the optimization of process parameters, cladding was deposited at different parametric settings, and their microhardness and sliding wear resistance was calculated as the output responses, according to Box Behnken Design (BBD) under Response Surface Methodology (RSM). Feedstock powders, developed claddings and worn samples were examined to study their surface morphology, microstructure, element composition and different phases using the SEM, Optical Microscopy, EDS, and XRD techniques. The result revealed that welding current and scanning speed are the most significant factors which govern the mechanical and tribological properties of cladding. The cladding was deposited at an optimized welding current 70 A, scanning speed of 192 mm min−1, standoff distance of 2 mm, and 25 wt.% YSZ reinforcement concentration revealed the fine and dense microstructure, resulting in maximum hardness and minimum wear. The microstructure was observed to be columnar dendrites, which grew epitaxially from the substrate. The addition of YSZ particles into the IN625 matrix resulted in the formation of Cr2O3 and ZrO2 stable oxides along with γ-Ni (FCC) phases. The wear test showed that the weight loss in claddings was mainly due to abrasive wear.