bluuebunny/crossref_metadata_2025 huggingface dataset:
A water-stable copper-based nanosized metal–organic framework for discriminative sensing of amines
Authors: Álvarez García Pablo , Álvarez Rubiera Enrique , Gutiérrez Armayor David , Melendreras Candela , Soldado Ana Belen , Costa José Manuel , Lastra Elena , García Alonso Fco. J.
Published: June 2024

A novel crystalline Cu-based MOF has been prepared with a nanometer size. This nanomaterial has proven to be useful as a discriminative sensor of amines either in vapor phase via colorimetric detection or in water solution via luminescence analysis.
Machine learning-based epoxy resin property prediction
Authors: Jang Huiwon , Ryu Dayoung , Lee Wonseok , Park Geunyeong , Kim Jihan
Published: June 2024

This study accelerates the discovery of epoxy resins by effectively predicting their properties and unraveling intricate structure–property relationships, based on molecular simulation data and machine learning techniques.
Divergent pentafluoroethylation of styrene derivatives using CuCF2CF3
Authors: Fu Zhengjie , Tsui Gavin Chit
Published: June 2024

One reagent, the [CuCF2CF3] prepared from HCF2CF3, is capable of diverse pentafluoroethylation reactions of styrene derivatives.
Nickel-catalyzed arylative cyclization of 1,6-enynes: arylation of unactivated alkene moieties
Authors: Gao Jian , Wei Qi , Zhang Zeqing , Su Zhishan , Ming Jialin , Zhang Yongmin
Published: June 2024

We developed catalytic cyclization of 1,6-enynes, whereby an aryl group is introduced at an unactivated alkene moiety.
Insights into the mechanism and origin of solvent-controlled chemodivergence in the synthesis of Au-catalyzed bicyclo[2.2.1]heptanes from 3-alkoxy-1,6-diynes: a DFT perspective
Authors: Feng Aili , Zhang Dongju
Published: June 2024

DFT calculations proposed a new mechanism for the formation of the bridged ring and elucidated the solvent-controlled chemodivergence of the reaction, with the involvement of a key allyl-gold species.
Photocatalytic C–P bond formation based on the reaction of carbon-centered radicals with phosphides
Authors: Zhao Shi-Yi , Huang Yi-Yun , Deng Shi-Hao , Guan Zhi-Peng , Dong Zhi-Bing
Published: June 2024

This review focuses on the synthesis of C–P bonds using carbon-centered radicals with phosphorous compounds of different valence states (PIII, PV, P4) under photocatalysis.
Synthesis of surfactant-assisted nickel ferrite nanoparticles (NFNPs@surfactant) to amplify their application as an advanced electrode material for high-performance supercapacitors
Authors: Mushtaq Muhammad Waheed , Shahbaz Muhammad , Naeem Rabia , Bashir Shahid , Sharif Shahzad , Ali Kainat , Dogar Naveed Aslam
Published: June 2024

Nickel ferrite nanoparticles (NFNPs) were synthesized in an alkaline medium (pH ∼ 11) using a wet chemical co-precipitation technique.
Environment-friendly acids for leaching transition metals from spent-NMC532 cathode and sustainable conversion to potential anodes
Authors: Nair Anjali V. , Jayasree Silpasree S. , Baji Dona Susan , Nair Shantikumar , Santhanagopalan Dhamodaran
Published: June 2024

For a clean and sustainable world, energy storage systems like Li-ion batteries (LIBs) developed from recycled materials will play a vital role due to their wide range of applications.
MEchain—A novel mode to improve blockchain's real‐time and throughput
Authors: Cao Yunwei , Yang Ting , Wang Yu , Mao Gang
Published: June 2024

Blockchain trilemma is a considerable obstacle for today's decentralized systems. It is hard to achieve a perfect balance among decentralization, security, and scalability. Many popular blockchain platforms sacrifice scalability to preserve decentralization and security, resulting in low speed, reduced throughput, and poor real‐time performance (the time from transaction initiation to confirmation). Currently, there are several technologies, such as sharding, directed acyclic graph technology, sidechains, off‐chain state channels etc., that aim to improve throughput and real‐time performance. However, most of these solutions compromise the core feature of blockchain, which is decentralization, and introduce new security risks. In this paper, the authors propose a novel method, called MEchain, based on the Proof of Time Series Algorithm. MEchain consists of two models: the multi‐chain model and the elastic‐chain model. The authors’ experimental results show that these two models can enhance real‐time performance and throughput to a higher level in the industry.
Event‐triggered adaptive output feedback control of unmanned aerial vehicles under hybrid attacks
Authors: Li Rui , Zhang Lei , Lu Yufeng , Yi Chenying , Chen Liangyuan , Su Yi
Published: June 2024

This study addresses the adaptive dynamic output feedback (DOF) control for unmanned aerial vehicle systems subjected to hybrid attacks. These attacks are delineated by two Bernoulli variables, signifying denial‐of‐service (DoS) and deception attacks, respectively. In an effort to enhance energy efficiency and reduce communication costs in the presence of network delays, the study introduces an innovative probability event‐triggering mechanism (PETM). Subsequently, it crafts a DOF controller that operates based on the available measurement outputs. By harnessing Lyapunov stability theory, the study identifies sufficient conditions that guarantee the stability of the system's augmented dynamics. Finally, the efficacy and applicability of the proposed method are underscored through a case study on an unmanned aerial vehicle.
Stereo sample generation‐based domain generalization network for stereo matching
Authors: Xu Liying , Zhu Jie , Peng Bo , Liu Bingzheng , Zhang Zhe , Lei Jianjun
Published: June 2024

Recently, deep learning‐based stereo matching has achieved great success. However, models trained on the source domain dataset encounter substantial performance degradation when directly tested on an unseen target domain dataset because of neglecting the generalization to out‐of‐distribution (OOD) stereo samples. This paper proposes a stereo sample generation‐based domain generalization network (SGDG‐Net) for stereo matching. Specifically, to expand the distribution span of training samples, OOD stereo samples are generated to assist training. To effectively generate OOD left samples, a style transfer‐based generation mechanism is proposed to transmit perturbations to the source left samples. In addition, to generate the OOD right samples, a disparity‐assisted generation strategy is proposed by using disparity map labels as auxiliary information. Experimental results demonstrate that the proposed SGDG‐Net produces remarkable results on four benchmark datasets.
Probabilistic optimal power flow computation for power grid including correlated wind sources
Authors: Xiao Qing , Tan Zhuangxi , Du Min
Published: June 2024

This paper sets out to develop an efficient probabilistic optimal power flow (POPF) algorithm to assess the influence of wind power on power grid. Given a set of wind data at multiple sites, their marginal distributions are fitted by a newly developed generalized Johnson system, whose parameters are specified by a percentile matching method. The correlation of wind speeds is characterized by a flexible Liouville copula, which allows to model the asymmetric dependence structure. In order to improve the efficiency for solving POPF problem, a lattice sampling method is developed to generate wind samples at multiple sites, and a logistic mixture model is proposed to fit distributions of POPF outputs. Finally, case studies are performed, the generalized Johnson system is compared with Weibull distribution and the original Johnson system for fitting wind samples, Liouville copula is compared against Archimedean copula for modelling correlated wind samples, and lattice sampling method is compared with Sobol sequence and Latin hypercube sampling for solving POPF problem on IEEE 118‐bus system, the results indicate the higher accuracy of the proposed methods for recovering the joint cumulative distribution function of correlated wind samples, as well as the higher efficiency for calculating statistical information of POPF outputs.
An adaptive coupled control method based on vehicles platooning for intersection controller and vehicle trajectories in mixed traffic
Authors: Feng Lei , Zhao Xin , Chen Zhijun , Song Li
Published: June 2024

Connected and autonomous driving technologies offer a novel solution for intersection control optimization. Connected and autonomous vehicles (CAVs) can access signal plans and optimize trajectories to minimize delays and reduce fuel consumption. However, optimizing trajectories for individual vehicles significantly increases complexity, especially for joint optimization of traffic signals and vehicle trajectories. Given the current technical, regulatory, and policy constraints, a superior intersection management approach is necessary before fully automated driving is achieved. This paper introduces an adaptive coupling control (ACC) method based on vehicle platooning to optimize signal timings and vehicle trajectories in mixed traffic. Initially, vehicle platoon segmentation is conducted, led by CAVs. The study then proposes a single‐layer coupled optimization model based on vehicle platoons, simplifying the joint optimization model. To address logistic constraint difficulties, a linearization of the coupled model (LCM) method is developed. Numerical experiments demonstrate that the ACC method significantly reduces vehicle delay and fuel consumption. At high CAV penetration rates (0.8 < R <1) and high traffic volumes (over 900 pcu/h), vehicle platoon control delivers excellent performance, with delays and fuel consumption even lower than in a fully automated environment (R = 1). This surprising result suggests that the mixed platoon system (ACC method) positively impacts mixed traffic.
A novel nine‐level inverter, applicable in air plane ground power unit
Authors: Ebrahimi Reza , Kojabadi Hossein Madadi
Published: June 2024

In this study, a novel nine‐level inverter using one voltage source, 10 unidirectional and one bidirectional power switches, and two capacitors has been proposed to utilize in ground power units (GPUs). Selective harmonic elimination method has been applied to reduce the output voltage's THD to less than 3% with 115/200 V and 400 Hz. The proposed converter utilized a lower number of devices to output a nine‐level staircase in comparison to existing converters. Also, the proposed converter uses inherent self‐voltage balancing for capacitors' voltage. So, the control algorithm gets simpler. In this study, the topology analysis, modulation algorithm, capacitor calculation, loss, efficiency, and performance analysis of the proposed topology have been presented. The proposed circuit has been compared to recently published papers in terms of efficiency, switch, capacitor, diode, and source numbers. The theoretical and experimental performance of the topology has been verified by simulation on PSCAD and PSIM software and 350 W experimental setup.
Modal ordered shape factors as radar feature set
Authors: Salamah Salem , Aldhubaib Faisal
Published: June 2024

The characteristic polarisation states form a second layer feature set by reflecting shape attributes about that target, enabling better identification performance of the resonance signature. These shape factors reflect a structure's curvature extent, dihedral degree between corners, and the axial ratio between principal axes by determining two characteristic angles associated with the null polarisation state and a ratio of the optimum maximum and minimum received powers, respectively. However, the accuracy of the shape factors degrades with a poorly estimated resonance signature caused by noise, missing resonance due to occlusion or ambiguity in late time onset. Thus, the authors aim to reduce the effect of these problems using an ensemble average to filter noise and enhance the signal strength, properly selecting a modal order to ensure modal consistency of the signature and decay sum (DS) to select the late time onset properly to avoid missing resonance within the polarisation matrix. Finally, a paradigm of two jetfighters validated the factors' discriminative potential across an azimuth plane of low depression angle. The results showed that a DS around 0.4 improves the estimated factors over most resonance modes and azimuth directions. At most target aspects, the first‐order shape factors consistently predicted a dominant parallel wedge‐shaped structure, while the second‐order shape factors consistently predicted a trough‐shaped structure; finally, the third‐order factors revealed wedge‐shape attributes at forward look aspects but trough‐shaped attributes at backward look aspects.
Adaptive Takagi–Sugeno (T–S) fuzzy observer based fault tolerant control for DC–DC converters with robustness against uncertainties
Authors: Raja Muneeb Masood , Zhao Qing
Published: June 2024

This paper proposes a Takagi–Sugeno fuzzy system model based fault tolerant control scheme for DC–DC converters, which is robust against parameter uncertainties and achieves the output voltage of an ideal converter. The control involves estimating the duty cycle change in the form of a fault parameter required to track the output voltage, in the presence of several uncertain conditions including converter losses, variation in input voltage, and unknown and changing output load. An adaptive law is designed to estimate the fault parameter that guarantees state and parameter error convergence. The adaptive law is derived using the Lyapunov stability theorem and the required parameters are evaluated by solving a linear matrix inequalities optimization problem. The load resistance is estimated in parallel by using a Kalman filter and fed to the fault parameter estimation scheme. Furthermore, a fast and robust method to detect short and open circuit switch faults is also presented. The proposed technique offers a simple, yet effective method to regulate the output voltage under several faulty and uncertain conditions. The proposed technique is tested on a DC–DC boost converter simulation model and the demonstrated MATLAB/Simulink results show the effectiveness of the proposed algorithm.
The impact of soil erosion on environments: A case study of the Oued Beht Watershed (Morocco)
Authors: Moutaoikil Nassima , Benzougagh Brahim , Mastere Mohamed , El Fellah Bouchta , Lamrani Hind
Published: June 2024

Soil erosion poses a significant environmental challenge in the Oued Beht watershed, Morocco, impacting local ecosystems and water quality. This study investigates the causes and effects of soil erosion in this region, utilizing Geographic Information System (GIS) tools and field techniques to analyze land use changes, agricultural practices, soil properties, and precipitation patterns. The findings establish a clear link between soil degradation and declining water quality in nearby aquatic environments. Major contributors to soil erosion include intensive agriculture, climate change, deforestation, vegetation degradation, and steep terrain. To predict future erosion rates, models were used, emphasizing the need for proactive management strategies. To address these issues, the study suggests implementing sustainable agricultural practices and soil conservation measures like agroforestry, vegetative buffer strips, and slope management. These measures can effectively reduce soil erosion and its adverse effects on water quality. The study underscores the importance of integrated management approaches to preserve biodiversity and soil fertility in the region. The findings provide crucial information for policymakers to adopt sustainable land conservation and management policies, ensuring the protection of aquatic ecosystems and environmental sustainability in the Oued Beht watershed.
Comparative assessment of the state of growth and bioaccumulation of manganese in Poaceae growing on the Mbembele manganese mine in Gabon
Authors: Bekoung Assoumou Rudy , Ondo Zue Abaga Norbert , Tayebi Mohamed
Published: June 2024

The study conducted at the Mbembele manganese mine in Ndjolé, central Gabon, aimed to evaluate the manganese (Mn) levels in soil from the tailings dam and assess the phytoremediation potential of selected Poaceae species. Four species, namely Phacelurus gabonensis, Cenchrus setosus, Panicum sp, and an undetermined gramineae species, were chosen for their rapid growth, high biomass production, and adaptation to the mine's soil conditions. Soil analysis revealed elevated Mn concentrations, surpassing the average composition of the upper continental crust (UCC), indicating significant Mn contamination. The Poaceae species exhibited substantial biomass growth after six months, suggesting their adaptation to high Mn levels in the soil. Mn accumulation was generally higher in the roots than in the leaves, except for Phacelurus gabonensis, which showed higher Mn concentrations in the leaves. Interestingly, Mn concentrations in plant tissues were higher at three months than at six months, implying a limited biological uptake capacity over time for these species. While the bioconcentration factor (BCF) was less than 1 for all plants, only Phacelurus gabonensis demonstrated a translocation factor (TF) greater than 1, indicating its potential for moving Mn from roots to shoots. The findings suggest that, among the studied Poaceae species, Phacelurus gabonensis could be a promising candidate for phytoremediation of Mn-contaminated soils in Gabon. Renewing this species every three months may enhance its effectiveness in rehabilitating mining soils impacted by Mn contamination. The study provides valuable insights into the potential use of indigenous plant species for sustainable environmental remediation efforts in the region.
Anaerobic digestates from cow dung and food waste as fertilizers: Effect on tomato growth and yield
Authors: Erraji Hassan , Tallou Anas , Laiche Hayat , Asehraou Abdeslam
Published: June 2024

Organic farming systems aim to reduce chemical inputs including fertilizers and ensure sustainable and eco-friendly production while recycling local renewable resources such as organic wastes. The aim of this study is to investigate the effect of two anaerobic digestates on tomato yield and growth in open field conditions. Digestates consisting of cattle dung and food waste from a 15 m3 demountable digester and fixed-dome digester, respectively, were applied to tomato cultivation using tree fertilization treatments: 1) raw (PD100) and 2) diluted up to 50% (PD50) cattle dung digestate, 3) food waste digestate (DD), and an unfertilized treatment (control) for 21 weeks. The results showed that tomato plants fertilized with PD50 and DD were significantly higher (+34% and +33%, respectively) compared to the control and PD100 (p<0.05), and all digestate treatments significantly (p<0.05) enhanced plant elongation compared to the control. This study suggests that anaerobic digestates can be a helpful alternative in the perspective of partial substitution of chemical fertilizers for sustainable tomato production.
Antibacterial activity of Lactic acid bacteria strains Isolated from Marine Algae against Pathogenic Bacteria
Authors: Belasla Nouhaila , Brahimi Imane , Benyamane Meryem , Errachidi Faouzi , El Adlouni Chakib , Zinedine Abdellah
Published: June 2024

This work aims at evaluating the antibacterial activity of 14 lactic acid bacteria (LAB) strains isolated from two species of marine algae (Sargassum muticum and Ulva lactuca) against six pathogenic bacteria, including Escherichia coli ATCC 10536, Staphylococcus aureus ATCC 9144, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 33019, Bacillus sp. CIP 104717, and Salmonella sp. LAB inhibitory capacity was assessed by using agar well diffusion test. Results showed that significant inhibitory zones of 30.33, 23.33, 13, 12, 9, and 8 mm were obtained against E. coli, B. subtilis, B. cereus, Bacillus sp., Salmonella sp. and S. aureus, respectively. These findings underscore the potential use of marine LAB for producing antibacterial substances, suggesting their applications in biotechnological processes targeting food spoilage and human infections.
Patterns of infectious disease in ancient Brazilian groups: The role of different environments and demographic parameters
Authors: Okumura Mercedes
Published: June 2024

In the last 200ka, humans have explored and adapted to a changing world. Environmental challenges faced by humans today, like emergent pathogens and overpopulation, are not that different from the ones in the past. This article aims to discuss the patterns of disease observed in ancient human populations from southeastern and southern Brazil (hunter-gatherer groups associated to riverine and coastal shellmounds and agriculturalists associated to the Tupiguarani archaeological Tradition). The role of new pathogens and high demographic density will be discussed, as well as the interpretations regarding the frequencies of chronic infectious diseases that affect bones. We will also present the importance of understanding patterns of health and disease in past human populations in order to address present day scenarios related to climate change, vulnerable populations, and disease. Warning: This article discusses and presents images of ancient human remains. While we acknowledge that this can be a sensitive topic, we would like to stress the importance of studying and generating knowledge about past human populations which otherwise would be completely unknown and forgotten.
City of Stones in the Moroccan Middle Atlas: Special Funeral Rites
Authors: Benabdelhadi Mohammed , Benlamine Lalla Khadouje , Oujaa Aïcha
Published: June 2024

The Middle Atlas and particularly the Boulmane region is full of pre-Islamic funerary monuments. The overwhelming majority of them are circular tumuli. However, two burials from the “City of Stones” are completely different from this common pattern and are exceptional in many respects. They are an extension of each other. Each is topped by an imposing horizontal sandstone slab which gives it a megalithic appearance although they are natural formations in reality. The underlying cavity was used as a burial chamber. The first CPSI site displayed the incomplete skeleton of 3 individuals. One of them, found in lateral decubitus, is relatively complete in anatomical connection up to the pelvis. The remains of two incomplete skeletons without any anatomical connection are also present. The second burial of the CPSII monument, however, does not contain any anatomically connected skeleton but bones belonging to 4 different individuals. The pre-Islamic populations of the Moroccan Middle Atlas erected tumulus-type funerary monuments to accommodate primary burials which could be single or multiple. And at the same time they could desecrate some by exhuming the skeletons to redeposit them in natural rock cavities which serve as burial chambers for a secondary burial or a deposit.
Effect of Nozzle Shape on Fluid Flow and Heat Transfer characteristics of an Impinging Jet System – A Numerical Study
Authors: Allauddin Usman , Naeemullah  , Verdin Patrick G.
Published: June 2024

Impinging jet is one of the most efficient techniques to achieve a high heat transfer coefficient and is used in many engineering applications. The present study focuses on the effect of nozzle shape on fluid behavior and heat transfer characteristics. For the current investigation, circular, square, rectangular, and elliptical nozzles with identical hydraulic diameters are used with Reynolds number Re ranging from 15,000–35,000. The circular nozzle results are validated with the published numerical and experimental data. In the current study, it is found that as the Reynolds number increases, the value of the averaged Nusselt number increases in all circumstances. When examining the different nozzle shapes, the value of the averaged Nusselt number is higher when an elliptical nozzle is used. The contours of the surface Nusselt number and velocity streamlines are also presented. The contour shows that the heat flux is highest in the stagnation zone and gradually decreases to the sides because they are outside the impingent coverage. Moreover, the area between the jets has a low heat flux. The heat transfer in the impinging zone is initially raised as the jet-induced crossflow increases and achieves a peak value, and then reduced stream-wise because of the crossflow effect.
Design, fabrication and thermal analysis of parabolic trough collector
Authors: Behram Saqib , Mehmood Mariam , Ali Majid , Nazir Hassan , Waqas Adeel , Ud Din Qamar
Published: June 2024

Parabolic trough collector (PTC) is considered environmentally friendly and one of the green technologies with net-zero emissions. In this study, performance evaluation of a developed solar PTC system is performed by conducting a series of experimentation. The study focuses on the design, development, and thermal evaluation of a PTC prototype, under hot and humid climatic conditions of Islamabad, Pakistan. Thermal efficiency of the solar PTC system is determined and effect of solar irradiance on thermal efficiency and heat gain is evaluated. Energy and exergy efficiency of the PTC systems are determined 66%, and 38%, respectively.
Optimization of Impact Resistant Throwable Unmanned Ground Vehicle Using Mathematical Modeling Techniques
Authors: Sohail Hamza , Hamza Amir , Rashid Nasir , Ali Muhammad Saad , Ghani Taha
Published: June 2024

Unmanned Ground Vehicles are used for various reasons. One of them is used in search and rescue operations which are known as Throwable Unmanned Ground Vehicles. It is a type of Unmanned Ground Vehicle which can sustain falls from several meters. Such vehicles are easily deployable, lightweight and impact resistant. Wheels play an important role since they absorb most of the impact. To optimize the performance of such vehicle, mathematical modeling is necessary. In this research paper, the main goal is to model the system mathematically. Parameters like impact forces, elasticity, Young’s modulus and duration of impact depend highly on material properties and structure of wheels. Results show the effect of certain parameters on wheel’s design and materials. For that purpose three materials are chosen PCTPE, carbon fiber, and vulcanized rubber for wheels. Impact forces, and duration of time are plotted against height of fall and diameter of the wheel for these materials.
Parametric analysis of various design factors on characteristic performance of Non-Pneumatic Tyres
Authors: Naveed Ahmad , Saqib Muhammad Ali , Azeem Moiz Bin
Published: June 2024

Non-pneumatic tires (NPTs) have emerged as a promising alternative to conventional pneumatic tires. In this study, a systematic parametric analysis was conducted to assess the influence of various design factors, including cell size, cell wall thickness, cell round radius, and spoke band thickness on the performance of NPTs. The Taguchi method, in conjunction with ANOVA, was employed to leverage the design of experiments (DOE) approach for identifying optimal settings for the examined factors. This investigation on sets revealed that both cell size and cell round radius have a significant impact on the mechanical performance of NPT. Specifically, cell size was shown to significantly affect the deformation and strain, with respective contributions of 48.74% and 45.16%. Meanwhile, cell round radius exhibited a substantial impact on the von Mises stress and strain energy, with respective contributions of 44.02% and 45.30%. Moreover, spoke band thickness was observed to significantly influence the mass of airless tires, with a contribution of 44.75%. The findings of this study furnish valuable insights into the design and optimization of NPTs for diverse applications.
Energy and Exergy Analysis of Forced Convection Solar Drying of Allium Sativum With and With Out Sensible Heat Storage
Authors: Aqib Muhammad , Shah Mansoor Ul Hassan , Arbab Muhammad Saddique , Rehman Waheed Ur
Published: June 2024

In this article the energy & exergy analysis of forced convection solar dryer for drying of garlic has been investigated. The exergy parameter, air velocity has been taken to conduct the experiments and its effect on thermal efficiency. Forced draft fans were used in all the two working conditions. During the two conditions, with and without sensible heat storage system, the average air-velocities were 4.5, 9.5 and 11.4 m/s selected as ideal and subsequently its entire effect on thermal efficiency and outlet. The ambient temperatures were between (17-25) °C during the month of October and November. A DC fan is directly connected to the photovoltaic cell in the solar dryer. The thermal energy storage bed was packed with gravels with 1.5 in of thickness up to the surface of flat plate collector, the storage system becomes space-efficient. The average thermal efficiency with sensible heat storage materials was high as compared to system without sensible heat storage. The highest thermal efficiency of 61% was achieved. The maximum collector temperature obtained was 55 °C, with a mean temperature of 42 °C in the drying chamber. The collector’s greatest exergy loss was 30.38 kJ/kg and highest exergy efficiency was 70%.
Design and analysis of X-band metamaterial absorber
Authors: Jan Ziaullah , Razzaq Aneesa , Rahim Arbab Abdur , Rahman Khalid
Published: June 2024

This study introduces a novel metamaterial absorber operating in X-band frequency range, characterized by two resonating peaks. The proposed structure consist of four circular sectors connected by two cross resonators enclosed by a circular strip with the dielectric between them. FR4 is used as a substrate backed by a copper ground plane. Simulation results reveal that the reflection co-efficient remains consistently below -10dB across the entire X-band, ensuring effective absorption of incident electromagnetic waves. Moreover, the absorber achieves 100% absorptivity with the gain of -25dB under normal incidence. The validity of absorber performance is confirmed through impedance plot and Voltage Stand Waving Ration (VSWR) analysis, verifying the accuracy of S11 parameter. Furthermore, the proposed structure has a compact size of 0.1666 λ. The absorber’s robust performance validated through numerical analysis, positions it as a compelling candidate for various X-band applications, including radar systems, communication devices, and stealth technology. This research establishes the proposed metamaterial absorber as a promising solution for X-band electromagnetic wave attenuation needs, offering both superior performance and compact design.
Experimental Investigation of Vacuum Membrane Distillation (VMD) Performance Based on Operational Parameters for Clean Water Production
Authors: Iqbal Faisal , Asif Muhammad , Jafry Ali Turab , Bibi Wajeeha
Published: June 2024

Freshwater shortage is an ongoing concern across the world, due to increasing populations and climate change. Vacuum membrane distillation (VMD) is a viable approach for producing fresh water to meet the needs of society. In the current study, an experimental investigation has been conducted on a laboratory-scale single-stage module to explore the impact of operational parameters such as feed temperature, vacuum pressure, and feed salinity on the performance of vacuum membrane distillation (VMD), including permeate flux, gained output ratio, and specific thermal energy consumption. Results show that increasing the feed temperature and feed flow rate, and reducing the salinity, increases the permeate flux. As the feed temperature rises from 60 to 70°C, the permeate flux increases from 1.90 to 4.36 kg/m²h at a permeate pressure of 12 kPa and salinity of 30 g/L. Similarly, increasing the vacuum pressure from 12 to 18 kPa reduces the permeate flux. As a result, the specific thermal energy consumption increases from 728 to 803 kWh/m³. From experimental findings, it was observed that the rejected brine from VMD retains sufficient energy that could be utilized in another desalination system.
Development of Self-Compacting Geopolymer Concrete Using Fayalite Slag Aggregates
Authors: Ahmed Bushra , Rubab Rimsha , Abbasi Iqra , Abbas Zaheer , Yasir Hiba , Raza Ali
Published: June 2024

Because of its high cement consumption, which limits its use in concrete construction, self-compacting concrete requires a higher cement content and various admixtures. Therefore, it is prudent to explore alternative options to minimize environmental impacts while creating environmentally friendly self-compacting concrete. This study examines the use of fly ash (FA) and ultrafine slag (UFS) in self-compacting geopolymer concrete (SGC), supplemented with fayalite slag aggregates (FSA). These aggregates, in varying quantities up to 60%, were used instead of traditional sand. The rheological properties and compressive strength of SGC were investigated. The analysis revealed that the addition of FSA improved the flowability of SGC. Notably, using a combination comprising 60% FSA, the largest slump measurement of 683.5 mm was achieved. Substituting up to 20% of FSA generally improved the properties of SGC at all ages. After one year, the mixture containing 20% FSA outperformed other compositions, with a maximum compressive strength of 49.38 MPa.
Physique de la morphogenèse des coquilles de mollusques
Authors: Moulton Derek E. , Goriely Alain , Chirat Régis
Published: June 2024

Les mollusques sécrètent des coquilles, dont le développement soulève des questions déroutantes. Comment les bivalves produisent-ils une coquille dont les deux valves s’emboitent parfaitement l’une dans l’autre comme les pièces d’un puzzle ? Comment certaines ammonites, des céphalopodes fossiles, ont-elles formé de surprenantes coquilles asymétriques malgré une symétrie bilatérale de leur corps ?

Des modèles mathématiques fournissent une explication physique : la coquille enregistre l’histoire des déformations mécaniques de la membrane élastique qui la sécrète et de l’ensemble du corps de l’animal qu’elle contient.
Effondrement de châteaux de sable dans l’eau : des tsunamis de laboratoire
Authors: Sarlin Wladimir , Morize Cyprien , Sauret Alban , Gondret Philippe
Published: June 2024

Les tsunamis générés par des glissements de terrains ou la chute de pans de montagnes dans les océans, lacs ou fleuves, peuvent être particulièrement destructeurs et meurtriers pour les côtes avoisinantes.

Ces évènements ont été dernièrement reproduits en laboratoire, dans une configuration modèle semblable à celle d’un château de sable s’écroulant dans l’eau sous l’effet de la gravité.
Rückkehr in das Erwerbsleben nach Krebs – eine systematische
Übersichtsarbeit zu Prädiktoren in Deutschland
Authors: Breidenbach Clara , Ernstmann Nicole , Schellack Sophie , Degenhardt Marie , Heidkamp Paula , Heier Lina , Hiltrop Kati , Rick Oliver , Soff Johannes , Kowalski Christoph
Published: June 2024

Einleitung Mehr als ein Drittel der Krebsüberlebenden befinden sich im
erwerbsfähigen Alter. Die Rückkehr ins Erwerbsleben (englisch: return to work –
RTW) mit und nach Krebs ist für diese Gruppe deshalb ein wichtiges Thema –
häufig jedoch mit vielen Herausforderungen verbunden. Ziel dieser systematischen
Übersichtsarbeit ist es, die Prädiktoren für RTW nach Krebs spezifisch für
Deutschland aus der Literatur zu identifizieren sowie diese Faktoren zeitlich in
den onkologischen Behandlungsverlauf einzuordnen.

Methode Die systematische Recherche wurde im Juni 2022 mit PubMed
durchgeführt. Eingeschlossen wurden alle deutsch- oder englischsprachigen
Originalarbeiten, die zwischen den Jahren 2000 und 2022 unabhängig vom
Studiendesign veröffentlicht wurden, und die sich auf ein/e deutsche/s
Stichprobe/Sample beziehen.

Ergebnisse Von insgesamt 8.381 Treffern in der Meta-Datenbank wurden
schließlich 30 Publikationen bei der Synthese der Ergebnisse berücksichtigt. Ein
höheres Alter, niedrigere Bildung, niedrigerer sozioökonomischer Status, ein
höheres Erkrankungsstadium, ein progressiverer Krankheitsverlauf, stärkere
Nebenwirkungen der Behandlung, (schwerere) Fatigue, höhere psychische Belastung,
ein schlechterer Gesundheitsstatus, die berufliche Stellung als Arbeiter*in und
handwerkliche Tätigkeiten, Erwerbslosigkeit vor der Diagnose, eine negativere
Wahrnehmung der Arbeits(platz)umgebung und eine geringere Intention zur Arbeit
und geringere Arbeitsfähigkeit/subjektive Erwerbsprognose gingen in der
Literatur mit einer geringeren Wahrscheinlichkeit zum RTW nach Krebs einher.
Auch die Behandlungsart und Inanspruchnahme einer Rehabilitation wurden mit der
Wahrscheinlichkeit zum RTW in Verbindung gebracht.

Diskussion Es wurden soziodemografische, krankheitsbezogene und
psychosoziale sowie arbeits-bezogene Prädiktoren für RTW nach Krebs in
Deutschland identifiziert. Die Ergebnisse können dazu beitragen, zielgerichtete
Unterstützungsmaßnahmen zu entwickeln, die in konkreten Phasen der Behandlung
angewendet werden können. Die Vergleichbarkeit und Bewertungsmöglichkeiten der
Literatur zu den Prädiktoren für RTW sind aufgrund einer hohen Heterogenität bei
der Operationalisierung von RTW und dem methodischen Vorgehen eingeschränkt. Es
bedarf hier weiterer Vereinheitlichung.
New Dephenylated Analogues of (–)-Goniofufurone: Optimization of Synthesis from l-Xylose
Authors: Zelenović Bojana Srećo , Stanisavljević Sladjana , Popsavin Mirjana , Kojić Vesna , Benedeković Goran , Popsavin Velimir
Published: June 2024

Natural products containing highly oxygenated furanofuranone fragments are known for their potent biological activity, but also for their challenging total synthesis. In this study, the synthesis of five novel dephenylated (–)-goniofufurone analogues was completed and their cytotoxic activity against eight malignant and one normal human cell line was evaluated. Compared with previous syntheses of similar analogues, the synthesis was carried out starting from l-xylose, resulting in improved yields and a reduced number of synthetic steps for three divergent intermediates.
Feeding Practices of Colombian Families with Minors Younger than 18 Years during the Initial Phase of COVID-19 Quarantine
Authors: Dadán Silvana , Higuera-Carrillo Michelle , Camacho-Cruz Jhon , Daza-Carreño Wilson
Published: June 2024

The coronavirus disease 2019 (COVID-19) pandemic has raised concerns regarding food availability and access. The aim of this study is to describe feeding practices and associated factors in Colombian families with members younger than 18 years at the beginning of the 2020 quarantine. This is an observational, descriptive, cross-sectional study. An online survey was administered to parents or caregivers of minors younger than 18 years in Colombia, focusing on feeding practices. The analysis consisted of three steps: first, estimation of descriptive statistics; second, multiple correspondence analysis to derive an index for each main meal; and finally, generalized linear models were applied to each main meal index, incorporating predictors to explain changes in food consumption. A total of 1,419 participants were included. Among them, 654 (46%) indicated changes in their feeding practices during the quarantine due to reasons such as lack of funds, portion reduction to stretch food, difficulty in shopping, and perception of limited variety in the market. The perceived lack of variety while shopping significantly affected the breakfast index (p = 0.037), lunch index (p = 0.037), and dinner index (p = 0.001). Socioeconomic level influenced the breakfast index (p = 0.012) and lunch index (p = 0.012) but not the dinner index. Nearly half of the surveyed families perceived changes in their feeding practices during the COVID-19 pandemic, which were linked to socioeconomic status and the perceived lack of variety while shopping.
Floating Thrombus in the Aortic Arch: Rare Images
Authors: Cherkaoui Jaouad Mohamed Reda , Egueh Nour Abdoulrazak , Miqdadi Amal , Mahi Mohamed , Bouknani Nawal
Published: June 2024

Aortic floating thrombus is a rare, life-threatening disease. Most cases of aortic thrombus are diagnosed after embolic events; however, on rare occasion we may diagnose this condition incidentally during routine examinations as in our case.
Do Sleep Time and Duration Affect the Development of Prehypertension in Undergraduate Medical Students? An Experience from a Tertiary Care Hospital in Kolkata
Authors: Ali Sayan , Karmakar Samit , Chakraborty Arup , Ghosh Saptarshi
Published: June 2024

Introduction and Objective Hypertension is an evolving public health challenge at present, and it is preceded by a prehypertensive stage. Irregular sleep duration and pattern have been found to be linked with cardiovascular diseases. Medical students are highly vulnerable to low quality sleep due to pressure regarding the academic curriculum and poor lifestyle. The present study aimed to estimate the prevalence of prehypertension, describe the risk factors and sleep patterns of undergraduate medical students, and determine the association, if any, involving sleep time and duration and prehypertension.

Materials and Methods Data was collected from 254 undergraduate medical students via the Pittsburgh Sleep Quality Index (PSQI) questionnaire and a self-structured questionnaire. The frequency of events was established and the Chi-squared and t-tests were applied to determine the association. Finally, regression analysis was performed to determine the correlation.

Results Male sex, high body mass index (BMI), poor sleep quality, and night sleep duration shorter than 5 hours were found to be significant risk factors for the development of prehypertensive condition (prevalence of 42.5%). However, there were no statistically significant associations regarding prehypertension and family history, junk food and salt intake, physical activity and daytime napping, bedtime, and wake-up time. Night sleep duration shorter than 5 hours presented an odds ratio of 4.713 (p = 0.010) for the development of prehypertension after adjusting for other risk factors, such as male sex, sleep quality, and high BMI.

Discussion and Conclusion A high prevalence of prehypertension (42.5%) was noted among undergraduate medical students. Night sleep duration shorter than 5 hours was a significant risk factor for the development of prehypertension, whereas sleep time was not significantly associated with prehypertension.
Chinization of social education: a lifelong exploration of Ma Zongrong’s educational theory and practice
Authors: Liu Jinrong , Wang Xiaoxuan
Published: June 2024

As an outstanding scholar in social education research in the Republican period, Ma Zongrong devotes his life to promoting the “Chinization of social education.” Ma Zongrong believes that for social education to truly save the country and the people in China, the prerequisite is to localize social education. This study finds that the Chinization of social education advocated by Ma Zongrong refers to adapting the theory and practice of social education to China’s national conditions and manifesting Chinese characteristics. The specific connotations of Ma Zongrong’s Chinization of social education include the Chinization of social education objects, the Chinization of social education definitions, and the Chinization of social education goals. From a Chinese perspective, he introduces the advanced social education concepts of Japan and the West and combines them with China’s unique national conditions to form a form of social education with Chinese characteristics; from a global perspective, Ma Zongrong’s combination of Japanese and Western social education with China’s local education system provides a successful case worthy of study by the world.
Impact of CEO’s scientific research background on the enterprise digital level
Authors: Luo Yi , Cui Rongda , Ma Jian , Jin Yukun , Li Mengheng , Lin Shu
Published: June 2024

Leveraging the Chinese capital market, we investigate the relationship between a CEO’s scientific research background and the level of digitalization within enterprises. Our results demonstrate robust findings indicating that a CEO’s scientific research background significantly enhances the level of enterprise digitalization. Moreover, we observe that this correlation is more pronounced in companies controlled by non-state-owned enterprises, those operating within a more advanced digital economy, and those engaged in high levels of regional integration. Furthermore, we establish that the positive impact of a CEO’s research background on a company’s digitalization level is primarily driven by fostering the organization’s innovation drive. Overall, our research suggests that CEOs with scientific research backgrounds are instrumental in encouraging a culture of innovation within their firms, thereby enhancing enterprise digitalization performance. This study contributes to the literature by exploring the factors influencing enterprise digitalization levels through the lens of managerial experience and analyzing the economic implications of management experience on enterprise digital transformation. Methodologically, we have refined and enhanced the measurement approach for assessing enterprise digitalization levels. Practically, our findings underscore the importance of promoting cross-industry and cross-regional exchanges of high-caliber talent for executives, enterprises, and governmental entities alike.
Online training programs for adults with disabilities: a systematic review
Authors: González Desirée , Del Prete Annachiara
Published: June 2024

In the last decade, there has been an increase in online or digital technology-based training. Online training offers promising, accessible learning opportunities for everyone. However, few studies have specifically evaluated the scope of this training for adults with disabilities. The primary aim of this study is to conduct a systematic review of this topic. This involves evaluating the literature, including the methodology used, the variables analyzed, and the characteristics of the training program, as well as identifying gaps in the research. Our findings show that the number of publications is low, although there has been an increase in recent years. Furthermore, it is critical to highlight the importance of an intervention methodology grounded in scientific research and the evaluation of implementation fidelity. In general, online programs improve a variety of trained skills. Expanding interventions within this population, mainly targeting adult women with disabilities, is essential to promote equity and inclusivity in lifelong learning.
U.S.–China trade conflicts and R&D investment: evidence from the BIS entity lists
Authors: Hu Han , Yang Shihui , Zeng Lin , Zhang Xuesi
Published: June 2024

The economic outcomes of U.S.–China trade conflicts on Chinese enterprises remain ambiguous. Using the staggered export control lists released by the Bureau of Industry and Security (BIS) of the U.S. Department of Commerce in conjunction with data from Chinese publicly listed manufacturing firms, we identify Chinese entities subjected to these export controls. Our Difference-in-Differences (DID) estimates show that export restrictions induced by the entity lists enhance the R&D investment intensity among Chinese firms by 16.58% in the next year. The mechanism is that controls increase firms’ R&D investment through government subsidies, firms’ inventory adjustment and firms’ risk-taking. Heterogeneity tests show that the policy effect is more significant for State-owned enterprises (SOEs), firms with executives with foreign experience. In addition, the R&D promotion of firms supported by China’s industrial policy is more pronounced. Although controls significantly increase R&D inputs, they have little or negative effect on firms’ innovation outputs. Our study provides micro-level causal evidence on the economic impacts of the U.S.–China trade war.