bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on transition corridor boundary of distributed propulsion VTOL fixed wing
Authors: Cheng Yuxuan , Zhou Zhou , Wang Kelei
Published: February 2023

The transition state is the most critical and dangerous state of the VTOL fixed wing aircraft in the whole flight process. In this paper, a transition corridor for a distributed propulsion VTOL fixed-wing aircraft is studied based on the lift characteristics of the wing and the power constraints of the power unit. Firstly, according to the sliding flow theory, the dynamic characteristics models of the lift fan system in the front part of the fuselage and the distributed duct system in the rear part of the fuselage were established by introducing the influence factor of the duct, and verified with the test data. Secondly, according to the lift characteristics of the wing, the transition curves of the aircraft at different angles of attack are calculated, in which the transition curves corresponding to the zero-lift attack angle and stall attack angle constitute the lift characteristics transition corridor of the distributed propulsion VTOL fixed-wing aircraft. Finally based on the dynamic performance of the power unit model, calculate the lift characteristic transition each state point in corridor corresponding power demand, according to the power limit of the lift fan system, distributed duct system and power unit total power limitation, get distributed to promote vertical take-off and landing a fixed wing aircraft power limitation in lifting features and power unit under the condition of complete transition corridor. The final results show that the minimum forward velocity is inversely proportional to the attack angle. The power required by the tail distributed duct system will exceed the limit when the aircraft is in low speed and small dip angle transition. For the power limit boundary required, the power limit condition of individual component is stricter than the total power limit condition. The research results of this paper can provide some reference for the transition corridor research of such VTOL fixed-wing aircraft, and on this basis, the subsequent work such as parameter sensitivity analysis and control system design of transition corridor can be carried out.
Image enhancement method based on exposure fusion for UAV aerial photography
Authors: LI Liangliang , REN Jia , WANG Peng , LYU Zhigang , SUN Mengyu , LI Xiaoyan , GAO Wuqi
Published: February 2023

针对无人机航拍图像光照不均匀及自然雾导致影像质量退化问题, 提出了一种无人机航拍图像增强算法。利用改进的低照度图像增强算法均衡亮度对比度; 为了解决均衡后图像过增强问题, 提出了联合去雾及曝光融合的色彩矫正增强方法; 为了保留增强图像的边缘纹理信息, 设计了一种效果更佳的细节增强算法, 处理后统计直方图更为平滑, 可在一定程度上抑制部分噪声, 细节纹理信息更强。实验结果表明, 所提的航拍图像增强算法, 能够有效解决因光照不均或自然雾引起的影像退化现象, 提高了无人机航拍图像的质量, 主客观图像质量评价指标优于现有绝大多数主流算法, 性能更佳。
State estimation of power grid under smart grid integration based on FFCD-SOGI-PLL
Authors: ZHOU Xiangyu , ZHANG Zhen , MA Ruiqing , WU Chunling , LU Yong , XIANGLI Kang , WANG Danqing
Published: February 2023

在智能电网与新能源发电融合背景下, 电力电子接口装置的大量使用将给系统引入额外的直流偏置。因此, 电网电压信息获取算法的直流偏置抑制能力变得至关重要。二阶广义积分器锁相环(SOGI-PLL)广泛应用于电网信息的同步与提取, 可以有效抑制频率波动和相位跳变对电网状态估计精度的影响, 但其自适应频率反馈环节在实现谐波抑制的同时, 对于电网中含有的直流偏置非常敏感。针对这一问题, 提出了一种固定频率反馈的级联SOGI-PLL(FFCD-SOGI-PLL), 使用级联结构输入固定电网标称频率, 实现信号直流分量滤除, 增强了谐波抑制性能。通过小信号模型给出其稳定性分析和参数设计方法。实验结果表明, 在电网电压含有直流分量、谐波以及电网电压跌落时, 设计的FFCD-SOGI-PLL可以快速稳定地对电网电压状态信息进行精确估计。
Trainee Perspectives of Private Equity's Impact on Ophthalmology
Authors: Portney David S. , Goldstein Jenna , Berkowitz Sean T. , Novice Taylor S. , Patel Shriji , Law Janice , Tannen Bradford
Published: February 2023

Objective The accelerated involvement of private equity (PE) in ophthalmology has many potential implications for the future of the field. The aim of this study was to evaluate trainee perspectives on PE's impact on ophthalmology.

Methods An electronic survey was sent to trainees via an online ophthalmology research newsletter. The survey assessed for career goals and perspectives on the involvement of PE and its impact across a variety of attributes.

Results A total of 41 United States-based respondents responded to the survey, 68% were medical students and 32% were residents or fellows. Seventy-eight percent of respondents reported they would not consider working for a PE-owned practice. There was a negative perceived impact of PE for physician autonomy, long-term physician income, career advancement, and quality of care. There was a positive perceived impact for the number of physician extenders, more referral sources, financial support, bargaining with insurance companies, starting physician salary, and administrative burden. All respondents agreed (76% strongly agree, 24% somewhat agree) that education about practice options and ownership structures is important to include in residency program education, with preferred modalities of small group discussions and on-site learning.

Conclusions Trainees broadly perceive PE to negatively impact the practice of ophthalmology. While there were attributes perceived to be positively impacted by PE, these were not felt to be as important as those which may be negatively affected. New modalities for education about practice ownership options are necessary, and small group discussions and on-site learning may be of the highest yield for trainees.
A Case of Generalized Myasthenia Gravis Exacerbated by COVID-19
Authors: Kanatani Shingo , Yamaguchi Hiroshi , Oikawa Shizuka , Tokumoto Shoichi , Tomioka Kazumi , Nishiyama Masahiro , Nozu Kandai , Nagase Hiroaki
Published: February 2023

Myasthenia gravis (MG) is a rare, long-term neuromuscular disorder that can affect individuals of any age. In Japan, the Omicron variant of coronavirus disease 2019 (COVID-19) began spreading in 2022, and many cases of neurological symptoms caused by the virus have been reported. Although COVID-19 has been reported to exacerbate MG in adults, there are no reports on the effects of COVID-19 on the MG symptoms of pediatric patients. We report the case of a 6-year-old girl with a 3-year history of MG who presented to our hospital with symptom exacerbation after COVID-19 infection. Four days before admission, she developed fever with a runny nose and cough. Three days before admission, she developed severe bilateral blepharoptosis and progressive limb weakness, and 2 days before admission, she was diagnosed with COVID-19 by SARS-CoV-2 antigen test. Physical examination revealed moderate blepharoptosis and mild bilateral upper and lower limb weakness. We diagnosed her with worsening MG due to COVID-19, and she was administered 400 mg/kg intravenous immunoglobulin (IVIG) daily for 5 days with continued oral corticosteroids and tacrolimus. The patient's symptoms improved promptly after admission and, at discharge 7 days after admission, her symptoms had significantly improved. During the 1-month outpatient follow-up period, she remained stable and the anti-acetylcholine receptor (AchR) antibody level was reduced to 14.6 nmol/L (from 18.5 nmol/L on admission). Our case suggests that COVID-19 exacerbates MG in both children and adults.
On the effects of suitably designed space microstructures in the propagation of waves in time modulated composites
Authors: Mattei O. , Gulizzi V.
Published: February 2023

In the one-dimensional case, the amplitude of a pulse that propagates in a homogeneous material whose properties are instantaneously changed in time will undergo an exponential increase due to the interference between the reflected and transmitted pulses generated at each sudden switch. Here, we resolve the issue by designing suitable reciprocal PT-symmetric space-time microstructures so that the interference between the scattered waves is such that the overall amplitude of the wave will be constant in time in each constituent material. Remarkably, for the geometries proposed here, a pulse will propagate with constant amplitude regardless of the impedance between the constituent materials, and for some, regardless of the wave speed mismatch. We extend, then, these results to the two-dimensional case, by proposing suitable geometries that avoid the blow up of the wave amplitude at the source point due to the scattering associated with time modulation. Given that the energy associated with the wave will increase exponentially in time, this creates the possibility to exploit the stable propagation of the pulse to accumulate energy for harvesting.
A quasi-one-dimensional model for the stagnation streamline in hypersonic magnetohydrodynamic flows
Authors: Luo Kai , Wang Qiu , Li Jinping , Zhao Wei , Gu Sangdi
Published: February 2023

The flow near the stagnation streamline of a blunt body is often attracted and analyzed by using the approximation of local similarity, which reduces the equations of motion to a system of ordinary differential equations. To efficiently calculate the stagnation-streamline parameters in hypersonic magnetohydrodynamic (MHD) flows, an improved quasi-one-dimensional model for MHD flows is developed in the present paper. The Lorentz force is first incorporated into the original dimensionally reduced Navier–Stokes equations to compensate for its effect. Detailed comparisons about the shock standoff distance and the stagnation point heat flux are conducted with the two-dimensional Navier–Stokes calculations for flows around the orbital reentry experiment model, including gas flows in thermochemical nonequilibrium under different magnetic field strengths. Results show that the shock curvature should be considered in the quasi-one-dimensional model to prevent accuracy reduction due to the deviation from the local similarity assumption, particularly for hypersonic MHD flows, where the shock standoff distance will increase with larger magnetic strength. Then, the shock curvature parameter is introduced to compensate for the shock curvature effect. A good agreement between the improved quasi-one-dimensional and the two-dimensional full-field simulations is achieved, indicating that the proposed model enables an efficient and reliable evaluation of stagnation-streamline quantities under hypersonic MHD flows.
Inertial amplified topological metamaterial beams
Authors: Ni Anchen , Shi Zhifei
Published: February 2023

To break the limitation of large mass required for low-frequency topologically protected interface modes (TPIMs), a novel inertial amplified topological metamaterial beam is proposed in this work. Detailed analytical and numerical studies are conducted to investigate the dynamic characteristic of this system. The Dirac cone (DC) is formed at the boundary of the Brillouin zone through the zone-folding method. Thanks to the inertial amplification mechanism, the lower-frequency DC and wider local resonance bandgaps (LRBGs) are obtained without sacrificing total stiffness or increasing total mass. Besides, the DC and LRBG can be tuned effectively by the arm length ratio of the lever. In order to realize the TPIM, two topologically distinct supercells are constructed by space modulation of resonators. Transmission simulation confirms the existence of TPIM between two domains with different topological properties. The energy concentration of TPIM is quantified by the quality factor. Moreover, the tunability and robustness of TPIM are also verified. Besides, to further enlarge the response area of TPIM, the sandwich structure is proposed. Although the peak displacement is reduced with the enlargement of response area, the displacement is still well confined within the sandwich layers. This novel inertial amplified topological metamaterial beam is expected to promote the application of topological devices, especially in the low-frequency lightweight challenging conditions.
Advanced materials engineering in historical gypsum plaster formulations
Authors: Mishmastnehi Moslem , Van Driessche Alexander E. S. , Smales Glen J. , Moya Alicia , Stawski Tomasz M.
Published: February 2023

We show how historical gypsum plaster preparation methods affect the microstructure and the wettability properties of the final stucco materials. We reproduced a traditional Persian recipe (Gach-e Koshteh,~14th century AD), which involves a continuous mechanical treatment during plaster hydration. These samples were compared with a laboratory-replicated historical recipe from Renaissance Italy (Gesso Sottile,~15th century AD) and contemporary low-strength plaster. TheKoshtehrecipe induces the formation of gypsum platelets, which exhibit preferential orientation in the plaster bulk. In contrast, the Italian and low-strength plasters comprise a typical needle-like morphology of gypsum crystals. The platelets inKoshtehexpose the more hydrophilic {010} face of gypsum in a much more pronounced manner than needles. Consequently, the Iranian plaster displays enhanced wettability, enabling its direct use for water-based decoration purposes, or as a fine finishing thin layer, without the need of mixing it with a binder material. Contrary, inSottile, gypsum crystals are left to equilibrate in large excess of water, which promotes the growth of long needles at the expense of smaller crystals. Typically, such needles are several times longer than those found in a control regular plaster. For this crystal habit, the total surface of hydrophilic faces is minimized. Consequently, such plaster layers tend to repel water, which can then be used, e.g., as a substrate for oil-based panel paintings. These findings highlight the development of advanced functional materials, by tuning their microtexture, already during the premodern era.
The human proton pump inhibitors inhibit
Mycobacterium tuberculosis
rifampicin efflux and macrophage-induced rifampicin tolerance
Authors: Lake M. Alexandra , Adams Kristin N. , Nie Feilin , Fowler Elaine , Verma Amit K. , Dei Silvia , Teodori Elisabetta , Sherman David R. , Edelstein Paul H. , Spring David R. , Troll Mark , Ramakrishnan Lalita
Published: February 2023

Tuberculosis treatment requires months-long combination chemotherapy with multiple drugs, with shorter treatments leading to relapses. A major impediment to shortening treatment is that
Mycobacterium tuberculosis
becomes tolerant to the administered drugs, starting early after infection and within days of infecting macrophages. Multiple lines of evidence suggest that macrophage-induced drug tolerance is mediated by mycobacterial drug efflux pumps. Here, using assays to directly measure drug efflux, we find that
M. tuberculosis
transports the first-line antitubercular drug rifampicin through a proton gradient-dependent mechanism. We show that verapamil, a known efflux pump inhibitor, which inhibits macrophage-induced rifampicin tolerance, also inhibits
M.tuberculosis
rifampicin efflux. As with macrophage-induced tolerance, the calcium channel-inhibiting property of verapamil is not required for its inhibition of rifampicin efflux. By testing verapamil analogs, we show that verapamil directly inhibits
M. tuberculosis
drug efflux pumps through its human P-glycoprotein (PGP)-like inhibitory activity. Screening commonly used drugs with incidental PGP inhibitory activity, we find many inhibit rifampicin efflux, including the proton pump inhibitors (PPIs) such as omeprazole. Like verapamil, the PPIs inhibit macrophage-induced rifampicin tolerance as well as intramacrophage growth, which has also been linked to mycobacterial efflux pump activity. Our assays provide a facile screening platform for
M. tuberculosis
efflux pump inhibitors that inhibit in vivo drug tolerance and growth.
A memristive autapse-synapse neural network: application to image encryption
Authors: Zhang Xi , Jiang Donghua , De Dieu Nkapkop Jean , Njitacke Zeric Tabekoueng , Ahmad Musheer , Zhu Liya , Tsafack Nestor
Published: February 2023

With the advent of the physical memristor, various memristive neural network models have been designed and analyzed to mimic some human brain functions. However, there is a realistic issue because many works reported the coupling of neuron models using either memristive synapse or memristive autapse, whereas in the real brain, a neuron can interact with both another neuron (memristive synapse) and with itself (memristive autapse). Two main ideas are developed in this work. First, we investigate the dynamics of two different neurons coupled via memristive synapse and memristive autapse. The analyses indicate that the global dynamics of this highly relies on the neuron’s coupling strength. Second, a cryptographic scheme based on both S-Box driven block compressive sensing and the memristive autapse synapse model is proposed. Performance analyses indicate that the coupling strength of the proposed neural network model can be adjusted to increase or decrease the security of medical data.
Lorentz transformation of three dimensional gravitational wave tensor
Authors: He Xiaokai , Cao Zhoujian
Published: February 2023

Recently there has been more and more interest in the gravitational wave (GW) of moving sources. This paper introduces a Lorentz transformation problem of GWs. Although the Bondi-Metzner-Sachs (BMS) theory has in principle already included the Lorentz transformation of GWs, the transformation of the three-dimensional GW tensor has not been explicitly calculated before. Within four-dimensional spacetime, GWs have the properties of ‘boost weight zero’ and ‘spin weight 2’. This fact makes the Lorentz transformation of GWs difficult to understand. In the current paper, we adopt the traditional three-dimensional tensor description of a GW. Such a transverse-traceless tensor describes the GW freedom directly. We derive the explicit Lorentz transformation of the GW tensor. The transformation is similar to the Lorentz transformation for an electric field vector and a magnetic field vector which are three-dimensional vectors. Based on the deduced Lorentz transformation of the GW three-dimensional tensor, we can construct the gravitational waveform of a moving source with high speed if only the waveform of the corresponding rest waveform is given.
Stability of the topological quantum critical point between multi-Weyl semimetal and band insulator
Authors: Yang Zhao-Kun , Wang Jing-Rong , Liu Guo-Zhu
Published: February 2023

One could tune a topological double-Weyl semimetal or a topological triple-Weyl semimetal to become a topologically trivial insulator by opening a band gap. This kind of quantum phase transition is characterized by the change of certain topological invariant. A new gapless semimetallic state emerges at each topological quantum critical point. Here we perform a renormalization group analysis to investigate the stability of such critical points against perturbations induced by random scalar potential and random vector potential. We find that the quantum critical point between double-Weyl semimetal and band insulator is unstable and can be easily turned into a compressible diffusive metal by any type of weak disorder. The quantum critical point between triple-Weyl semimetal and band insulator flows to a stable strong-coupling fixed point if the system contains a random vector potential merely along the z-axis, but becomes a compressible diffusive metal when other types of disorders exist.
Resonance contributions from χ

c0 in charmless three-body hadronic B meson decays*
Authors: Zhang Ya-Lan , Wang Chao , Lin Yi , Xiao Zhen-Jun
Published: February 2023

Within the framework of perturbative QCD factorization, we investigate the nonfactorizable contributions to the factorization-forbidden quasi-two-body decays

with

. We compare our predicted branching ratios for the

decay with available experiment data as well as predictions by other theoretical studies. The branching ratios of these decays are consistent with data and other theoretical predictions. However, in the Cabibbo-suppressed decays

with

, the values of the branching ratios are of the order of

and

. The ratio

between the decays

and

and the distribution of branching ratios for different decay modes in invariant mass are considered in this study.
The Restricted Boltzmann Machine Ansatz through Adiabiatic Routes
Authors: Korutcheva Elka , Korutchev Kostadin , Santalla Silvia N. , Rodríguez-Laguna Javier , Chamati Hassan
Published: February 2023

We discuss the expressive power of the quantum restricted Boltzmann machine Ansatz in order to represent faithfully the operation process of a quantum spin-glass system undergoing an adiabatic quantum computation process. We address both the representability and the trainability problems associated to the restricted Boltzmann machine Ansatz when we try to describe the ground state of a quantum Ising spin-glass in a transverse field. In our approach, we obtain the ground state of the system using exact diagonalization and find the optimal restricted Boltzman machine. Our preliminary results show that due to the complex spin-glass landscape, for some topologies of the restricted Bolztmann machine, the parameters of the representation are hard to be found.
Comparative study of protective coating properties of CR-39-based spectacle lenses
Authors: Mihova Gergana , Andreeva Andreana , Zografov Nikolay
Published: February 2023

This research aimed to study and compare the mechanical durability and contamination resistance of organic spectacle lenses for everyday use, based on CR-39 poly(allyl diglycol carbonate) (PADC), from different manufacturers. The objects of this research are selected corrective lenses from three different manufacturers. Each examined brand is represented by a reference uncoated lens and three other lenses with different types of protective coating. Each sample has been characterized experimentally in our laboratory conditions according to three indicators of the surface: microhardness, roughness, and wetting properties. The results of this study are targeted to the eye specialists to compare the surface properties, essential for the daily usage of the spectacles, as well as the differences depending on the lens manufacturer.
Strain tunable conductivity and reflectivity of low dimensional systems within the Hubbard model
Authors: Celebonovic Vladan
Published: February 2023

The aim of this paper is to investigate the conductivity and reflectivity of 1D and 2D systems under strain, within the Hubbard model. The calculations discussed here are a distinct improvement compared to a previous paper on the same subject by the present author, where only the real component of the conductivity was taken into account. In the calculations discussed here, both the real and imaginary components are taken into account. The final result is that the reflectivity is strain dependent. Details depend on the material parameters. Some hints on the possible practical applicability of the results are briefly mentioned.
Dynamic simulation of the quasiparticle excitations spectra in the magnetic bcc iron
Authors: Angelova Elena , Chamati Hassan
Published: February 2023

We used the LAMMPS algorithm for spin-lattice dynamics to model the coupled relaxation processes of the spin and lattice subsystems in bcc Fe with the aim to investigate the relevant phonon and magnon dispersion laws at T = 300 K. The atomic interactions were modeled via the semi-empirical many-body Chamati EAM potential, while the distance-dependent spin coupling relied on the Heisenberg-type Hamiltonian. In the state of mutual equilibrium of the spin and lattice ensembles, we have calculated the dynamic matrix of the phonons, the intermediate scattering function, the dynamical structure factor and finally the phonon spectra in bcc-iron. We found that the experimental data could be described best by the elastic [100] and [110] modes calculated in the dynamic structure factor approach for all wavevector absolute values q. Moreover, the impact of magnons on the phonon spectra is pronounced for all investigated directions, but there are elastic vibrations which remain unaltered by interaction with magnons.
Interfaces in ALD very thin Al2O3/HfO2 stacks studied by ellipsometry
Authors: Karmakov Y , Paskaleva A , Spassov D
Published: February 2023

Stacks and laminates of high-k binary oxides as Al2O3/HfO2 deposited by Atomic Layer Deposition (ALD) recently are intensively investigated not only for optical applications and micro/nano- electronics devices but also for replacing the conventional single dielectric layers in charge trapping flash memories. The efforts are focused on low cycle numbers of HfO2 to Al2O3 ALD and the way the sublayers alternate as blocks. Although the growth of the both HfO2 and Al2O3 sublayers in ALD stacks is a result of fixed cycles and intended refractive index dispersions in combination whit fixed optical band gaps, the stack parameters frequently show some flexibility in regard to the thickness in case of low dimensions. Ellipsometry is a known optical method with powerful algorithms for experimental data interpretations. Here the ellipsometric data on very thin Al2O3/HfO2 stacks as active unites in charge trapping memory devices were processed by suitable algorithms in order to determine the individual thickness of HfO2 and Al2O3 sublayers, their variation in stack depth and deviations from the nominal thicknesses. Interface regions were determined in the stack beginning and in an initial growth of every block. Interfaces were identified as Al2O3-HfO2 mixtures with a changeable composition and thickness in the stack depth.
Charge trapping effects in nonvolatile memory cells with HfO2/Al2O3 nanolaminated trapping layer
Authors: Spassov D , Paskaleva A , Guziewicz E , Stanchev T , Ivanov Tz
Published: February 2023

The charge trapping effects in memory cells with HfO2/Al2O3 nanolaminated stacks with two different thicknesses (2.4 and 3.5 nm) of the tunnel SiO2 layer were investigated. The HfO2/Al2O3 stacks were fabricated by atomic layer deposition and received post deposition annealing in O2. The structures with 3.5 nm tunnel oxide were found to provide higher density of trapped charges. The obtained trapped negative charge density is -3.56×10−6 C/cm2 and the positive one is 4.03×10−6 C/cm2. It is demonstrated that the electron trapping is significantly influenced by the amount of available electrons in the inversion layer. Under illumination, pulses with duration of 1 ms could provide trapped negative charge density equal to ~60% the value obtained at 10 s duration, where a saturation of the trapped charge is found. The hole trapping is not influenced by the illumination of capacitors and it is found to be slower than the electron one. Some aspects of the trapping process as well as some of the peculiarities in the capacitance-voltage curves obtained in the course of the measurements are briefly discussed.
Investigation of porous ZnSe thin films prepared by thermal evaporation
Authors: Dzhurkov V , Levi Z , Nesheva D , Hristova-Vasileva T , Terziyska P , Miloushev I , Tenev T
Published: February 2023

ZnSe films with thickness of 50, 70 and 100 nm were prepared on Corning 7059 glass substrates at room temperature by applying continuous or periodically interrupted physical vapour deposition at very low deposition rates (0.2 and 0.5 nm s−1). Part of the films was annealed at 200 °C after deposition. Optical absorption spectra determined from spectroscopic ellipsometry data show direct allowed transitions, which indicate that the films have microcrystalline structure. This is in agreement with scanning electron microscopy and atomic force microscopy results. The spectroscopic ellipsometry results also show that the porosity of the films is strongly affected by both manner of deposition and deposition rate; the annealing causes some porosity decrease. Optical transmission spectra reveal that the transmittance of as-deposited films, obtained by periodically interrupted manner is significantly influenced by their porosity.
Interactions between hard corals and reef fish communities in the Komodo National Park, East Nusa Tenggara Timur
Authors: Hadi T A , Sujono P A W , Clarita C , Budiyanto A , Edrus N I , Sulha S , Kefi A , Giyanto
Published: February 2023

The Komodo National Park is one of the largest National Parks in Indonesia that conserves not only terrestrial to protect the habitat of Komodo dragons but also marine areas. The marine ecosystems play important roles in protecting the shoreline from abrasion and supporting sustainability of seafood supplies for local communities. This study presents observed interactions between hard corals (number of species and coverage) and reef fish communities (number of species, abundance, and biomass). Coral monitoring was conducted at 12 stations in 2019. The study found 211 species of hard corals with an average hard coral cover of 30.84%. There is no significant correlation between the number of coral species with the fish communities. However, the branching coral cover shows a significant correlation with herbivorous fish communities (the number of species, abundance, and biomass. Such correlation may be attributed to the structural complexity of branching corals which provides shelters that prevent herbivorous fish from predation. Although branching corals are physically vulnerable to destruction and bleaching, their existence can promote herbivorous fish population sustainability and reef resilience.
Valorization of emperor fish (Lethrinus lentjan) skin for collagen isolation: effect of acetic acid ratio and extraction time
Authors: Firdayanti W , Trilaksani W , Purwaningsih S
Published: February 2023

About 30% of all the proteins in an animal’s body are found in the extracellular matrix, the major consisting of collagen. Industries that process emperor fish (Lethrinus lentjan) produce fish skin that can be utilized to produce collagen sustainably. The objective of this research is to determine the effect of various ratios acetic acid to fish skin and extraction times on the characteristics of collagen. Collagen from the skin of emperor fish was extracted and treated first. For the pretreatment, the skin was immersed in 0.1 M NaOH tenfold (w/v) and replaced after 2 hours for 24 hours at 4 °C. The soaking solution’s proteins, amino acids, and lipid content were all examined. A pre-treated sample was extracted in 0.5 M acetic acid for 24, 36, and 48 hours at 4°C in ratios of 1:10, 1:20, and 1:30. (w:v). The optimum treatment involved extracting for 48 hours at 1:30 (w/v) in acetic acid. The extracted collagen has a yield of 7.70±35% and a whiteness value of 66.76±0.2. The primary amino acids were glycine, proline, and alanine, according to the peptide patterns of the collagen from the skin of emperor fish, which showed α1 and α2 chains with molecular weights of 150-177 kDa. Additionally, this collagen was type 1, and its FTIR spectra and protein pattern were comparable.
Occurrence of emerging contaminants in Jakarta Bay, Indonesia: pharmaceuticals and personal care products
Authors: Sudaryanto A , Witama R O , Nosaki K , Tanoue R , Suciati F , Sachoemar S I , Hayami Y , Morimoto A , Nomiyama K , Kunisue T
Published: February 2023

Contamination by emerging contaminants of pharmaceutical and personal care products (PPCPs) has been a matter of global concern due to increasing their occurrence in the environment and their potential toxic effect. Despite the increasing number of publications on PPCPs in aquatic environments worldwide, only very few data are available in Indonesia. This study aims to determine PPCPs in the surface water of Jakarta Bay to understand their occurrence and distribution. Surface water was collected from 17 stations in September 2018. Samples were analyzed for 74 compounds of PPCPs using Ultra-fast Liquid Chromatography coupled with mass spectrometry. In general, among PPCPs analyzed, 20 compounds occur in seawater from Jakarta Bay, of which 15 PPCPs were detected in 50% of the sampling stations. Among PPCPs detected, N,N-diethyl-3-toluamide (DEET), Ibuprofen, O-desmethyl tramadol, Mefenamic acid, Sulfamethoxazole and Tramadol were the predominant with mean and range concentrations of 51(nd-170), 6.9(nd-22), 6.5(nd-31), 4.8(nd-13), 2.2(nd-6.1), and 131.9(nd-4.8) ng/l, respectively. Whereas the other PPCPs were one or more orders of magnitude lower. Generally, concentrations of PPCPs were higher in the inner bay than outer bays. Another study from freshwater rivers which flow to Jakarta Bay showed a high concentration of DEET indicating that the environment was an essential source of PPCPs.
Analysis of environmental carrying capacity and load capacity for bagan fisheries in the coastal waters of Donggala Regency, Central Sulawesi
Authors: Kalaba Y , Darman S , Hamzens W P S , Erny  , Yusuf R , Putera F H A , Walalangi J Y
Published: February 2023

Carrying capacity and environmental loads of coastal waters may have received less attention from development planners. Lift net fisheries, locally named bagan, has been growing rapidly in the coastal waters of Donggala Regency, Province of Central Sulawesi. This research was carried out to analyze the carrying capacity and environmental loads for controlling the expansion of bagan fisheries. This research was focused on the coastal waters of 19.53 km2 adjacent to Labean Village, Balaesang District. Measurements of aquatic environmental parameters were performed in-situ and water samples were collected in August to September 2018 for laboratory analysis. Analysis was carried out to determine locations that are environmentally suitable for bagan fisheries. and to calculate the maximum number of bagan that can be accommodated accordingly. All locations inside the study area are suitable for the fisheries. The maximum number of bagan varies with bagan sizes and their minimum gaps between the bagans (150m, 250m and 350m); 629 units for bagan of 7m x 7m with gaps od 150m or 231 units for bagan on 10m x 10m with gaps of 250m and 114 units for bagan of 20m x 20m with gaps of 350m.
Study of mechanisms and income differences of octopus fishermen on the Bhanto Bhenta’s local wisdom application in small islands areas
Authors: Hidrawati  , Sahari S , Limi M A , Surni  , Rosna
Published: February 2023

Bhenta-bhanto is local wisdom in catching octopus by fishermen from small islands in the Wakatobi Archipelago. This study aims to explain the mechanism of the bhenta-bhanto’s local wisdom and to find out the differences in fisherman income before and after the local wisdom is applied. The research occurred in Darawa Village, South Kaledupa District, Wakatobi Regency, Southeast Sulawesi, Indonesia. The research was conducted in March-December 2021. Research data were collected through observation, interviews, and literature study. Data were analyzed qualitatively and quantitatively using income analysis and Paired Sample T-Test. Based on the results of this study, it is known that the bhenta-bhanto is local wisdom in the form of an open and closed system for octopus fishing areas. The paired sample T-Test analysis shows differences in the income of octopus fishermen when the local wisdom of bhenta-bhanto is applied and when the local wisdom is not.
Development of the essential ecosystem area of Taman Kili-Kili Beach Trenggalek as a center for turtle conservation and ecotourism activities
Authors: Antriyandarti E , Ihsannudin
Published: February 2023

The Essential Ecosystem Area (EEA) of Taman Kili-Kili Beach, located in Trenggalek District (East Java), plays an essential role in preserving the biodiversity of protected animals, namely turtles, who play a significant role in maintaining the balance of marine ecosystems, starting from maintaining productive coral reef ecosystems to bringing essential nutrients from the ocean to the coast. This study aims to develop the EEA of Taman Kili-Kili Beach as a center for turtle conservation and an ecotourism destination to improve the community’s welfare while preserving the coastal and marine environment and the biodiversity of protected animals, especially turtles. This study uses a descriptive method to analyze the five forces model. The results show that the existence of turtle conservation will be a strength and attraction for tourists to visit EEA, especially for educational purposes and tourism on the beach. The main weakness is the lack of management of ecotourism support units such as souvenir centers, restaurants, and adequate rest areas. EEA of Taman Kili-Kili Beach can be developed by improving service and quality as an ecotourism destination and a turtle conservation center. This improvement also faces the threat of new entrants and substitutes and competes with competitors.
Comparison of the wear behavior and surface properties of zirconia and resin-based CAD/CAM restorative materials after different sandblasting procedures
Authors: Alper Seval Başpınar , Tekçe Neslihan , Fidan Sinan , Balcı Sibel
Published: February 2023

Objective: To evaluate the effects of different sandblasting procedures on the wear and surface properties of zirconia and resin-based CAD/CAM restorative materials and to evaluate the relationships among materials and procedures. Materials and Methods: A total of 160 specimens of 2 mm thickness were prepared from Cerasmart, Vita-Enamic, Tetric-CAD, and Katana-Zirconia CAD/CAM materials. Each material was divided into four groups. Group-1: Control; Group-2: 29 μm Al2O3; Group-3: 30 μm CoJet; and Group-4: 50 μm Al2O3. Sandblasting procedures were applied from a distance of 10 mm for 15 s at 2 bar pressure. The volume loss resulting from sandblasting was calculated. The samples were then scanned with a Nanovea-PS50 non-contact profilometer. The Ra, Rz, and Sa values were recorded. The data were analyzed with the Shapiro-Wilk test and two-way ANOVA. Results: Group-4 showed the highest Ra and Rz values in all materials. The highest Sa and volume differences values were observed for Cerasmart, Vita-Enamic, and Tetric-CAD in Group-4; similar values were obtained for Katana-Zirconia. When the materials were compared, Cerasmart exhibited the highest volume differences, Ra, Rz, and Sa values in Group-4, while Katana-Zirconia demonstrated the lowest. Conclusions: Sandblasting procedure and material type showed a significant impact on the wear and surface properties. The abrasive effect increased with the increasing Al2O3 particle sizes for resin-matrix materials. Sandblasting with 50 μm Al2O3 exhibited the lowest wear and surface roughness values for Katana-Zirconia and the highest for Cerasmart.
The mechanical and physical properties of microcrystalline cellulose (MCC)/sisal/PMMA hybrid composites for dental applications
Authors: Sosiati Harini , Rizky Arif Muhammad , Latief Aldi Lukman Maulana , Adi Rahmad Kuncoro , Hamdan Sinin
Published: February 2023

The study on polymethyl methacrylate (PMMA)-based composites in dental applications has gained much interest in recent years, resulting in many exciting studies worldwide. In those research, various filler types of reinforcing PMMA have been studied extensively. This study combines the microcrystalline cellulose (MCC) particles (0, 1, 2, 3, 5 vol.%) and sisal fiber to strengthen PMMA. We investigate their effects on the flexural, impact, hardness, compressive strength, water absorption, and thermal properties of (MCC)/sisal/PMMA hybrid composites. Scanning electron microscopy (SEM), universal testing machine (UTM), hardness Vickers, thermogravimetry analysis (TGA), and ANSYS Workbench 2022 R1 software are utilized to characterize the properties of the composites. X-ray diffraction (XRD) is used to characterize the degree of crystallinity of MCC and sisal fiber. Adding MCC to alkali-treated sisal/PMMA decreases the flexural and impact strengths but increases the hardness. Adding 1 and 2 vol.% MCC produces maximum flexural and impact strength and hardness values. Simulation on a composite added with 1% MCC by applying a full force load of 14.4 N yields compressive strength of 42.56 MPa. Thermal stability of all composites with and without MCC shows similarity until 250 °C but gradually degrades at over 250 °C, particularly for composites with MCC. Besides, as the addition of MCC increases, the water absorption also increases, with the lowest value of 37.54μg mm−3obtained by the composite added with 1 vol.% MCC, which is within the range of the standard dental materials.
Improved electrothermal performance of graphene-carbon nanotubes composite films utilizing AgNWs coating method
Authors: Zhang Yongqing , Jiang Yizhou , Ge Feng , Li Yunbo
Published: February 2023

A safe and high-performance electrothermal heater needs a lower operating voltage to produce heat for a long time and with high efficiency. The graphene-carbon nanotubes composite films and the AgNWs (siliver nanowires) dispersions were prepared and the AgNWs were successfully coated on to the composite films. The electrothermal performance of composite films with different carbon nanotubes (CNTs) contents, polymer additions and coating AgNWs were investigated. The maximum heating temperature decreases when the content of the polymer increases. In addition, the maximum temperature increases with the addition of CNTs. The sheet resistance gradually decreases with improving AgNWs coated amount and the sheet resistance changes little with the bending times on the whole. The microstructure of composite films coated with AgNWs revealed that AgNWs filled the holes on the surface of the composite films. Besides, the electrothermal efficiency, heating rate and cooling rate were significantly improved. For the electrothermal performance of the composite film coated with AgNWs only on the contact surface, the electrothermal efficiency, heating rate and cooling rate were also significantly improved compared with those of the composite films without an AgNWs coating. Therefore, composite film coating with AgNWs is one effective method to significantly improve the electrothermal performance for Gr composite film.
Numerical simulation of materials-oriented ultra-precision diamond cutting: review and outlook
Authors: Zhao Liang , Zhang Junjie , Zhang Jianguo , Dai Houfu , Hartmaier Alexander , Sun Tao
Published: February 2023

Ultra-precision diamond cutting is a promising machining technique for realizing ultra-smooth surface of different kinds of materials. While fundamental understanding of the impact of workpiece material properties on cutting mechanisms is crucial for promoting the capability of the machining technique, numerical simulation methods at different length and time scales act as important supplements to experimental investigations. In this work, we present a compact review on recent advancements in the numerical simulations of material-oriented diamond cutting, in which representative machining phenomena are systematically summarized and discussed by multiscale simulations such as molecular dynamics simulation and finite element simulation: the anisotropy cutting behavior of polycrystalline material, the thermo-mechanical coupling tool-chip friction states, the synergetic cutting responses of individual phase in composite materials, and the impact of various external energetic fields on cutting processes. In particular, the novel physics-based numerical models, which involve the high precision constitutive law associated with heterogeneous deformation behavior, the thermo-mechanical coupling algorithm associated with tool-chip friction, the configurations of individual phases in line with real microstructural characteristics of composite materials, and the integration of external energetic fields into cutting models, are highlighted. Finally, insights into the future development of advanced numerical simulation techniques for diamond cutting of advanced structured materials are also provided. The aspects reported in this review present guidelines for the numerical simulations of ultra-precision mechanical machining responses for a variety of materials.
Improved inter-protein contact prediction using dimensional hybrid residual networks and protein language models
Authors: Si Yunda , Yan Chengfei
Published: February 2023

The knowledge of contacting residue pairs between interacting proteins is very useful for the structural characterization of protein–protein interactions (PPIs). However, accurately identifying the tens of contacting ones from hundreds of thousands of inter-protein residue pairs is extremely challenging, and performances of the state-of-the-art inter-protein contact prediction methods are still quite limited. In this study, we developed a deep learning method for inter-protein contact prediction, which is referred to as DRN-1D2D_Inter. Specifically, we employed pretrained protein language models to generate structural information-enriched input features to residual networks formed by dimensional hybrid residual blocks to perform inter-protein contact prediction. Extensively bechmarking DRN-1D2D_Inter on multiple datasets, including both heteromeric PPIs and homomeric PPIs, we show DRN-1D2D_Inter consistently and significantly outperformed two state-of-the-art inter-protein contact prediction methods, including GLINTER and DeepHomo, although both the latter two methods leveraged the native structures of interacting proteins in the prediction, and DRN-1D2D_Inter made the prediction purely from sequences. We further show that applying the predicted contacts as constraints for protein–protein docking can significantly improve its performance for protein complex structure prediction.
The Role of Social Work Education in Relation to Empathy and Self-Reported Resilience: Results from Entry to Exit of Social Work Education on the Island of Ireland during the COVID-19 Pandemic
Authors: McFadden Paula , Ross Jana , Byrne Julie , Flanagan Niamh , Dolan Rose , Kirwan Gloria , Kelly Eleanor , Shore Caroline , McDonald Orla , Wilson Elaine , Slavin Paula , Roulston Audrey , McCartan Claire , Ketola Markus
Published: February 2023

The COVID-19 pandemic has affected all aspects of people’s lives worldwide, including the work of social workers and the education of social work students. Field placements are a significant part of social work education, but during the pandemic they were cut short and most teachings moved online. The current mixed methods study examined the effects of social work education on social work students’ empathy and resilience during the COVID-19 pandemic on the island of Ireland. A matched sample of forty-nine students completed an online survey at the start (T1) of their degree and at the end (T2). A further 229 students who only completed the T1 survey were compared to 70 others who only completed the T2 survey. The results showed improved resilience in the cohort comparison. There were no differences in empathy in the matched sample nor between the cohorts. Thematic analysis of students’ narratives showed that they found the switch to online learning difficult, with some reporting negative impacts on their mental health and the abrupt ending of placements impacting their feelings of preparedness for practice. Implications of this study and future research areas are discussed.
The racialized celebrity other in perfume advertisements
Authors: McAllister Matthew P , Beykont Yasemin , Forde Sydney L
Published: February 2023

Despite significant scholarship on the semiotics and ideology of perfume advertising, its racialized nature is underexamined. This is surprising given perfume-ad characteristics that incentivize racialized representations, especially ads using celebrities, and racist constructions of smell and scent. Using critical advertising studies, sensory studies, and bell hooks’ concept of the racialized Other, this article argues that perfume ads are markedly racialized. The racial semiotics of 10 print ads—five with BIPOC celebrities and five with White—are critiqued, with BIPOC celebrities essentialized as inherently exotic, wild, and primitively sexual, while White celebrities symbolize elegance, classic beauty, and uniqueness.