bluuebunny/crossref_metadata_2025 huggingface dataset:
Anchoring Monodispersed NiSe@Ni Particles on Graphene for Energy Storage in Supercapacitors
Authors: Xiao Xianbin , Jin Fangzhou , Pu Zhongsheng , Zhu Peng , Wei Zhiqiang , Yang Hua , Jiang Jinlong
Published: May 2023

In this study, monodispersed NiSe@Ni particles were successfully anchored on graphene sheets by electroless nickel plating combined with a chemical-vapor-reaction process, in which the nickel particles were first deposited onto graphene sheets and subsequently transformed in situ into NiSe@Ni at an elevated temperature. The obtained product showed a unique multi-dimensional coupling structure, namely, monodispersed NiSe@Ni particles (0 D) anchored on graphene sheets (2 D), which enabled maximum synergy on the specific surface area, conductivity, and the electrochemical activity of NiSe, Ni, and graphene multi-phases. The NiSe@Ni/graphene composite showed a specific capacity of 302 mAh g−1 at a current density of 1 A g−1 in a potassium-hydroxide-electrolyte solution. Meanwhile, the hybrid supercapacitor of NiSe@Ni/graphene//AC exhibited a high energy density of 68.0 Wh kg−1 at 803.0 W kg−1 and maintained 72.53% of the initial capacity after 10,000 cycles at a current density of 10 A g−1.
Achieving Ultralow-Density, High-Purity Au Foam Hohlraum with Hierarchical Porous Structure
Authors: Tan Xiulan , Wang Jian , Luo Jiangshan , Niu Gao , Wang Chaoyang
Published: May 2023

High Z (atomic number) metallic foams with a low density and high purity are urgent demands in high energy-density physical experiments. They suppress plasma expansion and convert the laser pulses to X-rays more uniformly and efficiently. Thus, we synthesized an ultralow-density and high-purity Au foam hohlraum with a hierarchical porous structure via a template-dealloying method in this paper. Silica (SiO2) beads were introduced as the sacrificial templates due to their high stability at an elevated temperature. The Au and Ag nanoparticles were successively deposited onto the SiO2 templates via an electroless deposition process to form an Ag@Au@SiO2 core-shell structure. Cylindrical Ag@Au@SiO2 hohlraum was achieved using a filter-casting technique with a patented mold. Afterward, an Au-Ag alloy was generated during 36 h of calcination at 400 °C. Self-supported Au foam hohlraum with the hierarchical porous structure was gained after the SiO2 templates were removed, followed by the dealloying of the Ag from the Au-Ag alloy. A self-supporting Au foam hohlraum with a density as low as 0.2 g/cm3 and a purity of 99.37% was achieved, and the density decreased by about 44.5% when compared with our previous Au foam (density: 0.36 g/cm3, purity: less than 96%) using microspherical polystyrene as the sacrificial template. Thus, the ultralow-density, high-purity Au foam hohlraum may exhibit profound application in high-energy physical experiments in the near future.
Tribological Behavior of Doped DLC Coatings in the Presence of Ionic Liquid Additive under Different Lubrication Regimes
Authors: Sadeghi Mohammadamin , Omiya Takeru , Fernandes Filipe , Vilhena Luís , Ramalho Amilcar , Ferreira Fábio
Published: May 2023

Diamond-like carbon (DLC) coatings are widely used in industries that require high durability and wear resistance, and low friction. The unique characteristics of DLC coatings allow for the possibility of creating adsorption sites for lubricant additives through the doping process. In this study, the combined use of europium-doped diamond-like carbon (Eu-DLC), gadolinium-doped diamond-like carbon (Gd-DLC), and pure DLC coatings and an ionic liquid (IL) additive, namely, trihexyltetradecylphosphonium bis (2-ethylhexyl) phosphate [P66614] [DEHP], with a 1 wt.% concentration in polyalphaolefin (PAO) 8 as a base lubricant was investigated. Higher hardness, higher thin-film adhesion, a higher ratio of hardness to elastic modulus, and a higher plastic deformation resistance factor were achieved with the Gd-DLC coating. The CoF of the Gd-DLC coating paired with the IL was superior compared to the other pairs in all lubrication regimes, and the pure DLC coating had a better performance than the Eu-DLC coating. The wear could not be quantified due to the low wear on the surface of the DLC coatings. The friction reduction demonstrates that tribological systems combining Gd-DLC thin films with an IL can be a potential candidate for future research and development efforts to reduce friction and increase the efficiency of moving parts in internal combustion engines, for instance.
Longitudinal Principal Component and Cluster Analysis of Azerbaijan’s Agricultural Productivity in Crop Commodities
Authors: Niftiyev Ibrahim , Ibadoghlu Gubad
Published: May 2023

Understanding long-term agricultural productivity is essential for designing agricultural policies, planning and targeting other economic policies (e.g., industrial policy), and managing agricultural business models. In a developing and oil-rich country such as Azerbaijan, agriculture is among the limited opportunities to diversify oil-based value added and address broad welfare issues, as farmers and agricultural workers account for a large share of total employment and the labor force. However, previous studies have not focused on an empirical assessment of the long-term and subsectoral productivity of crop commodities. Rather, they have used a highly aggregated and short-run perspective, focusing mainly on the impact of the oil sector on agricultural sectors. Here, we applied principal component analysis and hierarchical cluster analysis to identify similarities and differences in the productivity of specific crop commodities (e.g., cotton, tea, grains, tobacco, hay, fruits, and vegetables) between 1950 and 2021. We show that some crops are similar in terms of their variation, growth rates, and transition from the Soviet era to the post-Soviet period. Although the dynamics of change are different for food and non-food crops and for high- and low-productive commodities, it is still possible to narrow down specific subsectors that could reach the same productivity levels. This helps map out the productivity levels of crop commodities over time and across different subsectors, allowing for better policy decisions and resource allocation in the agricultural sector. In addition, we argue about some outlier commodities and their backward status despite extensive government support. Our results provide a common basis for policymakers and businesses to focus specifically on productivity and profitability from an economic standpoint.
Hydrogen-Terminated Single Crystal Diamond MOSFET with a Bilayer Dielectric of Gd2O3/Al2O3
Authors: Lv Xiaoyong , Wang Wei , Wang Yanfeng , Chen Genqiang , He Shi , Zhang Minghui , Wang Hongxing
Published: May 2023

In this paper, two dielectric layers of Al2O3 and Gd2O3 were prepared by an atomic layer deposition (ALD) and magnetron sputtering deposition (SD), respectively. Based on this, a metal-oxide-semiconductor field-effect transistor (MOSFET) was successfully prepared on a hydrogen-terminated single-crystal diamond (H-diamond), and its related properties were studied. The results showed that this device had typical p-type channel MOSFET output and transfer characteristics. In addition, the maximum current was 15.3 mA/mm, and the dielectric constant of Gd2O3 was 24.8. The effective mobility of MOSFET with Gd2O3/Al2O3 was evaluated to be 182.1 cm2/Vs. To the best of our knowledge, the bilayer dielectric of Gd2O3/Al2O3 was first used in a hydrogen-terminated diamond MOSFET and had the potential for application.
Preparation of Thiadiazole Modified UiO-68-CdS Composites for RhB Degradation under Visible Light Irradiation
Authors: Wei Lian-Qiang , Wei Jiu-Bin , Yang Fei , Li Zhi-Wei , Lai Hong-Fang
Published: May 2023

In this paper, the photosensitive Zr-MOF material Thiadiazole-modified UiO-68 (UiO-68N2S) was used to prepare CdS@UiO-68N2S composites by MOF post-reaction. The chemical composition is characterized using PXRD, FT-IR, XPS, SEM, and TGA. Rhodamine B was used as the model dye for photocatalytic degradation to evaluate the performance of CdS@UiO-68N2S under visible light irradiation. Experimental results show that the degradation rate of a 25 mg/L RhB solution (10 mL) reached 94% with 10 mg CdS@UiO-68N2S as a photocatalyst under blue light irradiation in 13 h at room temperature. The mechanism study revealed that O2•− is the reactive oxygen species for the degradation of Rhodamine B. Recycle experiments showed that CdS@UiO-68N2S can be reused for three rounds without a significant reduction of its catalytic function.
Multichromic Behavior of Liquid Crystalline Composite Polymeric Films
Authors: Kondo Mizuho , Yanai Satoka , Shirata Syouma , Kakibe Takeshi , Nishida Jun-ichi , Kawatsuki Nobuhiro
Published: May 2023

In this study, we describe the synthesis of a cholesterol-linked cyanostilobazole salt dye and the tuning of its luminescence by physical stimuli such as electricity and grinding. The dyes exhibited liquid-crystalline properties at temperatures above 170 °C. Some of the solutions were transformed into orange luminescent gels upon the addition of poor solvents. When the solvent was evaporated, the resulting solid xerogel exhibited mechanochromism, its color changed, and its luminescent color changed from orange to red. Furthermore, we investigated the construction of functional gels (mechanochromic gels) that can respond to two stimuli, damage detection by abrasive responsiveness, and electrical response using ionic liquid complexes of polymers as dispersing media. This study provides a new strategy for tuning and switching luminescence using non-chemical stimuli in a single-component system using aggregation.
Cryoablation and Immunotherapy: An Enthralling Synergy for Cancer Treatment
Authors: Medlej Zain al Abidine , Medlej Wassim , Slaba Sami , Torrecillas Pedro , Cueto Antonio , Urbaneja Alberto , Garrido Adolfo Jimenes , Lugnani Franco
Published: May 2023

As less invasive options for surgical tumor removal, minimally invasive ablative techniques have gained popularity. Several solid tumors are being treated with cryoablation, a non-heat-based ablation technique. Cryoablation data in comparison over time demonstrates better tumor response and faster recovery. Combining cryosurgery with other cancer therapies has been explored to improve the cancer-killing process. Cryoablation with the combination of immunotherapy, results in a robust and efficient attack on the cancer cells. This article focuses on investigating the ability of cryosurgery to create a strong antitumor response when combined with immunologic agents resulting in a synergetic effect. To achieve this objective, we combined cryosurgery with immunotherapy using Nivolumab and lpilimumab. Five clinical cases of lymph node, lung cancer, bone, and lung metastasis were followed and analyzed. In this series of patients, percutaneous cryoablation and addressing immunity agents were technically feasible. In the follow-ups, there appeared to be no radiological evidence of new tumor development.
Outcomes of a Multidisciplinary Team in the Management of Patients with Early-Stage Breast Cancer Undergoing Neoadjuvant Chemotherapy at a Community Cancer Center
Authors: Bhardwaj Prarthna V. , Mason Holly , Kaufman Seth A. , Visintainer Paul , Makari-Judson Grace
Published: May 2023

Background: The utilization of neoadjuvant chemotherapy (NAC) remains highly variable in clinical practice. The implementation of NAC requires coordination of handoffs between a multidisciplinary team (MDT). This study aims to assess the outcomes of an MDT in the management of early-stage breast cancer patients undergoing neoadjuvant chemotherapy at a community cancer center. Methods: We conducted a retrospective case series on patients receiving NAC for early-stage operable or locally advanced breast cancer coordinated by an MDT. Outcomes of interest included the rate of downstaging of cancer in the breast and axilla, time from biopsy to NAC, time from completion of NAC to surgery, and time from surgery to radiation therapy (RT). Results: Ninety-four patients underwent NAC; 84% were White and mean age was 56.5 yrs. Of them, 87 (92.5%) had clinical stage II or III cancer, and 43 (45.8%) had positive lymph nodes. Thirty-nine patients (42.9%) were triple negative, 28 (30.8%) were human epidermal growth factor receptor (HER-2)+, and 24 (26.2%) were estrogen receptor (ER) +HER-2−. Of 91 patients, 23 (25.3%) achieved pCR; 84 patients (91.4%) had downstaging of the breast tumor, and 30 (33%) had axillary downstaging. The median time from diagnosis to NAC was 37.5 days, the time from completion of NAC to surgery was 29 days, and the time from surgery to RT was 49.5 days. Conclusions: Our MDT provided timely, coordinated, and consistent care for patients with early-stage breast cancer undergoing NAC as evidenced by time to treatment outcomes consistent with recommended national trends.
Biomonitoring for Watershed Protection from a Multiscale Land-Use Perspective
Authors: de Mello Kaline , Taniwaki Ricardo Hideo , Macedo Diego Rodrigues , Leal Cecília Gontijo , Randhir Timothy O.
Published: May 2023

The types and intensification of land use in the watershed affect the living organisms in aquatic ecosystems differently; this impact will also vary according to temporal and spatial scales. Understanding these interactions is crucial in the design of biomonitoring programs to detect the effect of different pollutants in freshwater ecosystems and improve watershed management and conservation strategies. Therefore, this paper qualitatively reviews biomonitoring studies in freshwater ecosystems to evaluate the impact of different land use types on multiple scales in watersheds. The paper is organized into four sections. The first section presents biomonitoring in different freshwater systems (streams, rivers, lakes, and reservoirs). In the second section, we describe the biomonitoring characteristics of the main land use types. In the third section, we explain how spatial and temporal scales affect biomonitoring. Finally, in the fourth section, we focus on biomonitoring planning and future prediction and discuss how to design biomonitoring programs and how to use models and eDNA in biomonitoring. Our review will assist in decision-making regarding biomonitoring programs in watersheds and will guide future studies on the different bioindicators for various land use types in diverse ecosystems worldwide.
Zonal Patterns of Changes in the Taxonomic Composition of Culturable Microfungi Isolated from Permafrost Peatlands of the European Northeast
Authors: Vinogradova Yulia A. , Kovaleva Vera A. , Perminova Evgenia M. , Shakhtarova Olga V. , Lapteva Elena M.
Published: May 2023

This paper provides the results of a study on fungal species diversity in the active and permafrost layers of peatlands within frozen peatbogs in the flatland areas of the cryolitozone, European Northeast of Russia (forest-tundra zone, southern and northern tundra subzones). Fungal taxonomic list includes eighty-three species from seventeen genera and two forms of Mycelia sterilia. The phylum Mucoromycota is represented by fifteen species (18% of total isolate number), and these species exhibit the following distribution by genus: Mucor (four), Mortierella (seven), Umbelopsis (three), Podila (one). Ascomycota is represented by sixty-eight species from thirteen genera. The genus Penicillium dominates the species saturation (thirty-seven species, 44%). Soil microfungal complex is represented by rare species (51%), random species (32%), frequent species (15%), and dominant species (2%). In peat soils, dominant species are Penicillium canescens (72%) and non-pigmented (albino) Mycelia sterilia (61%); abundant species are Talaromyces funiculosus (41%), Pseudogymnoascus pannorum (36%), albino Mycelia sterilia (29%), Umbelopsis vinacea (25%), Mortierella alpina (17%), Penicillium decumbens (21%), P. spinulosum (20%), and P. canescens (17%). In active layers of peat soils, abundant species are Penicillium thomii (14%), Mycelia sterilia (13%), Penicillium spinulosum (13%), Penicillium simplicissimum (13%) in forest-tundra; Talaromyces funiculosus (21%), albino Mycelia sterilia (15%), Umbelopsis vinacea (14%) in southern tundra; Penicillium decumbens (23%), P. canescens (17%), P. thomii (13%) in northern tundra. In permafrost peat layers, abundant species are Penicillium spinulosum (17%), Talaromyces funiculosus (34%), and Umbelopsis vinacea (15%) in forest-tundra; Pseudogymnoascus pannorum (30%) and Mortierella alpina (28%) in southern tundra; Pseudogymnoascus pannorum (80%) in northern tundra.
Control over Grid Reactive Power by Using a Powerful Regenerative Controlled-Speed Synchronous Motor Drive
Authors: Maklakov Aleksandr S. , Nikolaev Aleksandr A. , Lisovskaya Tatyana A.
Published: May 2023

The authors propose a technique for reactive power compensation using a powerful regenerative controlled-speed synchronous motor drive (SMD) based on a three-level (3L) neutral point clamped (NPC) active front-end rectifier (AFE) and a voltage source inverter (VSI). The review of technical solutions for reactive power compensation showed that the limitations on the transmitted reactive power in the system under consideration still have not been studied. The paper provides a mathematical description and proposes synthesis-friendly block diagrams of the mathematical 3L-NPC-AFE-VSI and SMD models. The developed models allow defining the instantaneous values of the total 3L-NPC-AFE power consumed from the grid depending on the SMD load diagram. It is noted that the 3L-NPC-AFE-VSI-SMD system is designed without considering the opportunities for reactive power generation. It was determined that the limit value of reactive power generated by a 3L-NPC-AFE depends on the DC link voltage, the grid current consumption and the modulation index. The possibility of reactive power compensation by the SMD system through a 3L-NPC-AFE was experimentally tested on the main drive of a metal plate hot rolling mill. The analysis of the results obtained showed that during the breakdown, an SMD can generate reactive power equal to 16% of the total rated power using a 3L-NPC-AFE at a rated DC link voltage and without overcurrent. It was shown that generating reactive power is expedient in low-load SMD operation modes or at idle. Research in this area is promising due to the widespread use of high-power SMD based on a 3L-NPC-AFE-VSI and the tightening of requirements for energy saving and efficiency and supply voltage quality. The proposed reactive power control technique can be used as part of an industrial smart grid.
An Efficient and Robust Method for Chest X-ray Rib Suppression That Improves Pulmonary Abnormality Diagnosis
Authors: Xu Di , Xu Qifan , Nhieu Kevin , Ruan Dan , Sheng Ke
Published: May 2023

Background: Suppression of thoracic bone shadows on chest X-rays (CXRs) can improve the diagnosis of pulmonary disease. Previous approaches can be categorized as either unsupervised physical models or supervised deep learning models. Physical models can remove the entire ribcage and preserve the morphological lung details but are impractical due to the extremely long processing time. Machine learning (ML) methods are computationally efficient but are limited by the available ground truth (GT) for effective and robust training, resulting in suboptimal results. Purpose: To improve bone shadow suppression, we propose a generalizable yet efficient workflow for CXR rib suppression by combining physical and ML methods. Materials and Method: Our pipeline consists of two stages: (1) pair generation with GT bone shadows eliminated by a physical model in spatially transformed gradient fields; and (2) a fully supervised image denoising network trained on stage-one datasets for fast rib removal from incoming CXRs. For stage two, we designed a densely connected network called SADXNet, combined with a peak signal-to-noise ratio and a multi-scale structure similarity index measure as the loss function to suppress the bony structures. SADXNet organizes the spatial filters in a U shape and preserves the feature map dimension throughout the network flow. Results: Visually, SADXNet can suppress the rib edges near the lung wall/vertebra without compromising the vessel/abnormality conspicuity. Quantitively, it achieves an RMSE of ~0 compared with the physical model generated GTs, during testing with one prediction in <1 s. Downstream tasks, including lung nodule detection as well as common lung disease classification and localization, are used to provide task-specific evaluations of our rib suppression mechanism. We observed a 3.23% and 6.62% AUC increase, as well as 203 (1273 to 1070) and 385 (3029 to 2644) absolute false positive decreases for lung nodule detection and common lung disease localization, respectively. Conclusion: Through learning from image pairs generated from the physical model, the proposed SADXNet can make a robust sub-second prediction without losing fidelity. Quantitative outcomes from downstream validation further underpin the superiority of SADXNet and the training ML-based rib suppression approaches from the physical model yielded dataset. The training images and SADXNet are provided in the manuscript.
SAA-UNet: Spatial Attention and Attention Gate UNet for COVID-19 Pneumonia Segmentation from Computed Tomography
Authors: Alshomrani Shroog , Arif Muhammad , Al Ghamdi Mohammed A.
Published: May 2023

The disaster of the COVID-19 pandemic has claimed numerous lives and wreaked havoc on the entire world due to its transmissible nature. One of the complications of COVID-19 is pneumonia. Different radiography methods, particularly computed tomography (CT), have shown outstanding performance in effectively diagnosing pneumonia. In this paper, we propose a spatial attention and attention gate UNet model (SAA-UNet) inspired by spatial attention UNet (SA-UNet) and attention UNet (Att-UNet) to deal with the problem of infection segmentation in the lungs. The proposed method was applied to the MedSeg, Radiopaedia 9P, combination of MedSeg and Radiopaedia 9P, and Zenodo 20P datasets. The proposed method showed good infection segmentation results (two classes: infection and background) with an average Dice similarity coefficient of 0.85, 0.94, 0.91, and 0.93 and a mean intersection over union (IOU) of 0.78, 0.90, 0.86, and 0.87, respectively, on the four datasets mentioned above. Moreover, it also performed well in multi-class segmentation with average Dice similarity coefficients of 0.693, 0.89, 0.87, and 0.93 and IOU scores of 0.68, 0.87, 0.78, and 0.89 on the four datasets, respectively. Classification accuracies of more than 97% were achieved for all four datasets. The F1-scores for the MedSeg, Radiopaedia P9, combination of MedSeg and Radiopaedia P9, and Zenodo 20P datasets were 0.865, 0.943, 0.917, and 0.926, respectively, for the binary classification. For multi-class classification, accuracies of more than 96% were achieved on all four datasets. The experimental results showed that the framework proposed can effectively and efficiently segment COVID-19 infection on CT images with different contrast and utilize this to aid in diagnosing and treating pneumonia caused by COVID-19.
Radiofrequency Echographic Multi Spectrometry (R.E.M.S.): New Frontiers for Ultrasound Use in the Assessment of Bone Status—A Current Picture
Authors: Al Refaie Antonella , Baldassini Leonardo , Mondillo Caterina , Giglio Elisa , De Vita Michela , Tomai Pitinca Maria Dea , Gonnelli Stefano , Caffarelli Carla
Published: May 2023

Osteoporosis is a frequently occurring skeletal disease, and osteoporosis-related fractures represent a significant burden for healthcare systems. Dual-Energy X-ray Absorptiometry (DXA) is the most commonly used method for assessing bone mineral density (BMD). Today, particular attention is being directed towards new technologies, especially those that do not use radiation, for the early diagnosis of altered bone status. Radiofrequency Echographic Multi Spectrometry (REMS) is a non-ionizing technology that evaluates the bone status at axial skeletal sites by analyzing raw ultrasound signals. In this review, we evaluated the data on the REMS technique present in the literature. The literature data confirmed diagnostic concordance between BMD values obtained using DXA and REMS. Furthermore, REMS has adequate precision and repeatability characteristics, is able to predict the risk of fragility fractures, and may be able to overcome some of the limitations of DXA. In conclusion, REMS could become the method of choice for the assessment of bone status in children, in women of childbearing age or who are pregnant, and in several secondary osteoporosis conditions due to its good precision and replicability, its transportability, and the absence of ionizing radiation. Finally, REMS may allow qualitative and not just quantitative assessments of bone status.
Does Sterilization Affect the Performance of Single-Step Resin Composite Polishers?
Authors: Papadopoulou Christina , Anagnostou Maria , Masouras Konstantinos , Margaritis Vasileios , Paximada Charikleia
Published: May 2023

(1) Background: Single-step polishers are used extensively for resin-composite polishing. The purpose of this study was to evaluate the effect of sterilization on their performance. (2) Methods: Optrapol Next Generation/Ivoclar-Vivadent, Jazz Supreme/SS White, Optishine Brush/Kerr and Jiffy Polishing Brush/Ultradent were used for polishing a nanohybrid resin composite (IPS Empress Direct/Ivoclar-Vivadent). Polishers (n = 40) were microscopically inspected before use. After polishing, surface roughness (Sa, Sz, Sdr, Sci) and gloss were determined. Polishers were subsequently sterilized and microscopically re-examined. The process was repeated four times on new samples (n = 200). Data were analyzed using the Friedman test and Wilcoxon post hoc test, at α = 0.05. (3) Results: Optrapol’s performance improved after the first sterilization for Sa and gloss, whereas it declined after the fourth sterilization for Sa. Jazz’s, improved after the second sterilization for Sa and gloss and after the third sterilization for Sdr. An improvement trend was observed for Optishine after the first sterilization, but not statistically significant. Sa, Sz, and gloss declined after the fourth sterilization. Jiffy’s performance was inconsistent, with a trend of performance loss after the fourth sterilization. (4) Conclusions: Performance of all polishing systems improved after the initial sterilization, but deteriorated after the fourth sterilization cycle. However, their performance can be considered clinically acceptable for a longer period of use.
Accelerating Use of Drones and Robotics in Post-Pandemic Project Supply Chain
Authors: AlRushood Musaab A. , Rahbar Fred , Selim Shokri Z. , Dweiri Fikri
Published: May 2023

The global COVID-19 pandemic forced the construction industry to a standstill. In the wake of the pandemic, this sector must be prepared to make bold, innovative moves to prepare for the future. Over the past few years, the use of drones and robotics has expanded with many commercial uses, including in the construction industry. Drone-driven automation has an enormous impact in improving productivity and reducing cost and schedule overruns. The use of drones, along with the application of Internet of Things (IoT) and robotics, can make a significant impact on the supply chain and improve inventory accuracy, leading to faster and more cost-effective building projects. This paper will propose and statistically substantiate an optimization model for supply chain management through the accelerated use of drones and Artificial Intelligence (AI) in the post-pandemic era. The use of smart devices and IoT will allow warehouse managers to have real-time visibility of the location and inventory tracking, as well as enabling warehouse workers to access information without being physically present. Cutting-edge drone technology can quickly perform inspections to make inventory control more economical and efficient. While they are certainly not a perfect fit for every building surveillance task, drones have many advantages for probing buildings in search of leaks, performing aerial surveys, and dealing with security issues more cost-effectively than manual procedures, thereby leading to improved communication and collaboration between different stakeholders. This paper includes a real-life case study and dynamic mathematical model to demonstrate how this approach results in a project’s materials becoming visible, traceable, and easily tracked from end to end.
Noise Impact Assessment of UAS Operation in Urbanised Areas: Field Measurements and a Simulation
Authors: Škultéty Filip , Bujna Erik , Janovec Michal , Kandera Branislav
Published: May 2023

This article’s main topic is an assessment of unmanned aircraft system (UAS) noise pollution in several weight categories according to Regulation (EU) 2019/947 and its impact on the urban environment during regular operation. The necessity of solving the given problem is caused by an increasing occurrence of UASs in airspace and the prospect of introducing unmanned aircraft into broader commercial operations. This work aims to provide an overview of noise measurements of two UAS weight categories under natural atmospheric conditions to assess their impact on the surrounding environment. On top of that, modelling and simulations were used to observe and assess the noise emission characteristics. The quantitative results contain an assessment of the given noise restrictions based on the psychoacoustic impact and actual measured values inserted into the urban simulation scenario of the Zilina case study located in northwest Slovakia. It was preceded by a study of noise levels in certain areas to evaluate the variation level after UAS integration into the corresponding airspace. Following a model simulation of the C2 category, it was concluded that there was a marginal rise in the level of noise exposure, which would not exceed the prescribed standards of the Environmental Noise Directive.
Gender Differences in the New Interdisciplinary Subject Informatik, Mathematik, Physik (IMP)—Sticking with STEM?
Authors: Bahr Tobias , Zinn Bernd
Published: May 2023

The current state of research in computer science education outlines gender differences in motivation, interest, and elective subject decisions in favor of male students. This study takes an exploratory approach to examine the gender differences in the interdisciplinary STEM profile subject Informatik, Mathematik, Physik (in short: subject IMP), which combines the three subjects of computer science, mathematics, and physics. A survey was conducted involving n = 336 (m = 236, f = 88, o = 12) subject IMP students in the 10th grade attending a Gymnasium in Baden-Württemberg, Germany. The deciding factors for choosing the subject, subject interest, motivation, and more were measured using a questionnaire. Overall, the subject IMP is most chosen by male students. For those students choosing the subject IMP, no statistically significant gender differences in subject interest in IMP, mathematics, and the STEM area or in motivation and vocational orientation in natural science and engineering were found in contrast to the state of research. The interdisciplinary character of the subject IMP could be more appealing to girls than computer science by itself. We conclude that, with a higher participation rate of female students, the subject IMP could be a first step in getting more women into STEM fields.
A 237 GHz Traveling Wave Tube for Cloud Radar
Authors: Li Ying , Pan Pan , Song Bowen , Zhang Lin , Feng Jinjun
Published: May 2023

In this article, the first 237 GHz traveling wave tube (TWT) is presented as a high-power amplifier for the terahertz (THz) cloud radar. As is common with previous G-band traveling wave tubes developed at Beijing Vacuum Electronics Research Institute, the 237 GHz traveling wave tube employs a 20 kV, 50 mA pencil electron beam focused using periodic permanent magnets (PPMs) to achieve compactness. A folded waveguide (FWG) slow-wave structure (SWS) with modified circular bends is optimized to provide high impedance and eliminate sideband oscillations. Limited by insufficient drive power, this device is not saturated. The measured maximum output power and gain are 8.9 W and 35.7 dB, and the 3 dB gain bandwidth achieves 4 GHz.
Wideband Circularly Polarized Magneto-Electric Dipole Antenna Array with Metallic Walls for Millimeter-Wave Applications
Authors: Shi Binlong , Cao Xiaowei , Deng Changjiang
Published: May 2023

This work proposes a new circularly polarized (CP) 4 × 4 magneto-electric (ME) dipole antenna array using metallic walls for 28 GHz band applications. The ME dipole element is surrounded by eight metallic walls and is excited fed by microstrip line. By introducing metallic walls, the 3-dB axial ratio (AR) bandwidth of the element is increased from 23% to 36.5%. The 4 × 4 array is fed by a simple 1-to-16 microstrip power divider. In contrast to the conventional substrate integrated waveguide (SIW) power divider using two layers, the proposed microstrip divider only needs one substrate layer. The experimental 3-dB AR bandwidth of the array achieves 30.1%, ranging from 22.5 to 30.5 GHz, which falls inside the −10 dB impendence bandwidth. The measured maximum gain is 19.2 dBic.
Energy Management Strategies of Grid-Connected Microgrids under Different Reliability Conditions
Authors: Alshehri Mohammed Abdullah H. , Guo Youguang , Lei Gang
Published: May 2023

The demand for a reliable, cheap and environmentally friendly source of energy makes the integration of renewable energy into power networks a global challenge. Furthermore, reliability, as one of the core elements of efficient and cost-effective energy management options, is still among the dominant factors/techniques that receive more attention for realistic penetrations of renewable energy into the electricity grid. This paper proposes an efficient way of energy management for a grid-connected microgrid. The grid-connected microgrid used in the analysis consists of solar photovoltaic (P.V.) and battery. In this microgrid configuration, oftentimes, the output power might not be equal to the system demand; in this regard, it is expected that the mismatch between these output powers is not zero. However, to reduce the mismatch between demand and supply to be close to zero, this paper proposes strategies of increasing the rated power of solar, battery and grid separately and combining them with a view of finding the cheapest option among these strategies. The results have shown that the cost increment for different options is USD 280.792, 84.48 and 48.204 for storage, P.V. and grid, respectively. These have shown that the storage option is the most expansive option for improving P.V. grid-connected microgrids. This is followed immediately by the P.V. option, which is weather dependent. On the other hand, the grid option is the cheapest option for system reliability improvement. This paper is expected to be useful to both new researchers and experts who are working in energy management with an emphasis on the reliability aspect.
Economic Dispatch Optimization of a Microgrid with Wind–Photovoltaic-Load-Storage in Multiple Scenarios
Authors: Wang Haipeng , Wu Xuewei , Sun Kai , Du Xiaodong , He Yuling , Li Kaiwen
Published: May 2023

The optimal economic power dispatching of a microgrid is an important part of the new power system optimization, which is of great significance to reduce energy consumption and environmental pollution. The microgrid should not only meet the basic demand of power supply but also improve the economic benefit. Considering the generation cost, the discharge cost, the power purchase cost, the electricity sales revenue, the battery charging and discharging power constraints, and the charging and discharging time constraints, a joint optimization model for a multi-scenario microgrid with wind–photovoltaic-load storage is proposed in our study. Additionally, the corresponding model solving algorithm based on particle swarm optimization is also given. In addition, taking the Wangjiazhai project in Baiyangdian region as a case study, the effectiveness of the proposed model and algorithm is verified. The joint optimization model for a microgrid with wind–photovoltaic-load storage in multiple scenarios is discussed and investigated, and the optimal economic power dispatching schemes in multiple scenarios are also provided. Our research shows that: (1) the battery can play a role in peak shaving and valley filling, which can make microgrids more economical; (2) when the power purchase price is lower than the cost of renewable energy power generation, if the wind turbine and the photovoltaics are allowed to be discarded the microgrid will produce higher economic benefits; and (3) restricting the exchange power between the microgrid and the main power network will lead to a negative impact on the economy for the microgrid.
Innovative Approaches to Solar Desalination: A Comprehensive Review of Recent Research
Authors: Abu El-Maaty Ahmed E. , Awad Mohamed M. , Sultan Gamal I. , Hamed Ahmed M.
Published: May 2023

Solar desalination systems are a promising solution to the water scarcity problem since the majority of the earth’s water resources are salty. With the increasing focus on desalination research, many innovative methods are being developed to extract salts from saline water. Energy consumption is a significant concern in desalination, and renewable energy, particularly solar energy, is considered a viable alternative to fossil fuel energy. In this review, we will focus on direct and indirect solar desalination methods, specifically traditional direct solar desalination methods such as solar still and humidification dehumidification (HDH) desalination systems. We will also briefly discuss a recent advancement in the desalination method known as the fogging process, which is a development of the HDH desalination system.
The Fuel Flexibility of Gas Turbines: A Review and Retrospective Outlook
Authors: Molière Michel
Published: May 2023

Land-based gas turbines (GTs) are continuous-flow engines that run with permanent flames once started and at stationary pressure, temperature, and flows at stabilized load. Combustors operate without any moving parts and their substantial air excess enables complete combustion. These features provide significant space for designing efficient and versatile combustion systems. In particular, as heavy-duty gas turbines have moderate compression ratios and ample stall margins, they can burn not only high- and medium-BTU fuels but also low-BTU ones. As a result, these machines have gained remarkable fuel flexibility. Dry Low Emissions combustors, which were initially confined to burning standard natural gas, have been gradually adapted to an increasing number of alternative gaseous fuels. The paper first delivers essential technical considerations that underlie this important fuel portfolio. It then reviews the spectrum of alternative GT fuels which currently extends from lean gases (coal bed, coke oven, blast furnace gases…) to rich refinery streams (LPG, olefins) and from volatile liquids (naphtha) to heavy hydrocarbons. This “fuel diet” also includes biogenic products (biogas, biodiesel, and ethanol) and especially blended and pure hydrogen, the fuel of the future. The paper also outlines how, historically, land-based GTs have gradually gained new fuel territories thanks to continuous engineering work, lab testing, experience extrapolation, and validation on the field.
Risk Assessment of a Hydrogen Refueling Station in an Urban Area
Authors: Kwak Jongbeom , Lee Haktae , Park Somin , Park Jaehyuk , Jung Seungho
Published: May 2023

After the Paris Agreement was signed in 2015, many countries worldwide focused on the hydrogen economy, aiming for eco-friendly and renewable energy by moving away from the existing carbon economy, which has been the primary source of global warming. Hydrogen is the most common element on Earth. As a light substance, hydrogen can diffuse quickly; however, it also has a small risk of explosion. Representative explosion accidents have included the Muskingum River Power Plant Vapor Cloud Explosion accident in 2007 and the Silver Eagle Refinery Vapor Cloud Explosion accident in 2009. In addition, there was an explosion in a hydrogen tank in Gangneung, Korea, in May 2019, and a hydrogen refueling station (HRS) in Norway exploded in 2018. Despite this risk, Korea is promoting the establishment of HRSs in major urban centers, including downtown areas and public buildings, by using the Regulatory Sandbox to install HRSs. This paper employed the Hydrogen Risk Assessment Model (HyRAM) of Sandia National Laboratories (SNL), a quantitative risk assessment (QRA) program specialized in hydrogen energy for HRSs installed in major urban hubs. A feasibility evaluation of the site conditions of an HRS was conducted using the French land use planning method based on the results obtained through evaluation using the HyRAM and the overpressure results of PHAST 8.0. After a risk assessment, we confirmed that an HRS would be considered safe, even if it was installed in the city center within a radius of influence of jet fires and overpressure.
Adaptive Control Strategy for Stationary Electric Battery Storage Systems with Reliable Peak Load Limitation at Maximum Self-Consumption of Locally Generated Energy
Authors: Klausmann Florian , Klingler Anna-Lena
Published: May 2023

Nowadays, stationary battery storage systems are generally used to optimize the self-consumption of electricity generated locally or to limit the peak load of the local grid connection. Self-consumption optimization aims to achieve economic benefits by using more of the self-generated electricity within the local grid. Batteries used for the optimization of self-consumption tend to present low states of charge and, therefore, normally do not contribute to peak load limitation. Peak load limitation is used to minimize the grid connection power to enable more cost-efficient grid connections. However, this function can only be achieved year-round if there is sufficient surplus electricity production or if the battery can be charged from the grid. In the latter case, the batteries are often fully charged and do not significantly optimize the self-consumption. This study presents a new operating strategy that combines all the advantages of the previous operating modes with none of the disadvantages. This can be accomplished by combining the operation modes depending on the particular situation, together with a variable battery charging process. Furthermore, a simulation-based optimization procedure is introduced for the optimal configuration of the parameters. The potential of this operating strategy is demonstrated based on application examples. As a result, the operating strategy enables reliable peak load limitation all year round while simultaneously optimizing self-consumption. The operating strategy can easily be adapted to meet changing requirements such as the increasing charging power demands of electric vehicles. Thanks to a simple process based on common measured variables, the operating strategy can be integrated smoothly into practical applications.
Novel Harmonic Distortion Prediction Methods for Meshed Transmission Grids with Large Amount of Underground Cables
Authors: Akhmatov Vladislav , Søndergaard Bukh Bjarne , Liberty Skovgaard Chris , Gellert Bjarne Christian
Published: May 2023

The tremendous and fast green transition in Denmark has initiated the large-scale grid-integration of renewable energy sources, electrification of energy consumption, and establishment of PtX and Energy Islands, setting goals for transmission grid development—such as the establishment of new connections—and for grid reconstruction—such as the extensive substitution of overhead lines (OHLs) with underground cables (UGCs). The share of UGCs in the Danish transmission grid is increasing. Presence of UGC has resulted in that resonances of the harmonic impedance characteristics of the transmission grid are brought within the harmonic order range coinciding with the harmonic emission sources and causing systemwide increase of the harmonic voltage distortion in the 400 kV transmission grid. The transformation of the 400 kV transmission grid has given rise to the need to predict harmonic voltage distortion using simulation models to secure an adequate power quality and support investment decisions and harmonic mitigation for the grid stage, which has not yet been established and which differs from the present grid. This paper presents the experiences of Energinet, the Transmission System Operator (TSO) in Denmark, with harmonic distortion in the Danish transmission grid due to the establishment of 400 kV UGCs, and the development of measurement-validated methods for harmonic distortion simulation and prediction. The paper also presents ongoing developments within, and research addressing, the prediction of harmonic distortion in meshed grids; for example, it explores where and how an analytical approach can replace observational studies with many numerical simulations. The methods shall make it possible to predict whether, where in the transmission grid, and for which harmonic orders connections that have not yet been commissioned may cause the violation of the planning levels, and which mitigations are necessary for bringing the harmonic distortion below the planning levels with respect to a given margin.
A Review on Flame Stabilization Technologies for UAV Engine Micro-Meso Scale Combustors: Progress and Challenges
Authors: Velidi Gurunadh , Yoo Chun Sang
Published: May 2023

Unmanned aerial vehicles (UAV)s have unique requirements that demand engines with high power-to-weight ratios, fuel efficiency, and reliability. As such, combustion engines used in UAVs are specialized to meet these requirements. There are several types of combustion engines used in UAVs, including reciprocating engines, turbine engines, and Wankel engines. Recent advancements in engine design, such as the use of ceramic materials and microscale combustion, have the potential to enhance engine performance and durability. This article explores the potential use of combustion-based engines, particularly microjet engines, as an alternative to electrically powered unmanned aerial vehicle (UAV) systems. It provides a review of recent developments in UAV engines and micro combustors, as well as studies on flame stabilization techniques aimed at enhancing engine performance. Heat recirculation methods have been proposed to minimize heat loss to the combustor walls. It has been demonstrated that employing both bluff-body stabilization and heat recirculation methods in narrow channels can significantly improve combustion efficiency. The combination of flame stabilization and heat recirculation methods has been observed to significantly improve the performance of micro and mesoscale combustors. As a result, these technologies hold great promise for enhancing the performance of UAV engines.