bluuebunny/crossref_metadata_2025 huggingface dataset:
Rady społeczne jako instrument rozliczalności społecznej na poziomie lokalnym?
Authors: Kołomycew Anna
Published: February 2023

The article aimed to examine to what extent the social (advisory) councils operating in Poland can be considered a social accountability mechanism. The author refers to the theoretical assumptions of social accountability, which constitutes one of the forms of accountability of public authorities. Additionally, the paper presents the peculiarities of social councils, which are well-known, highly institutionalized, and formalized collegial bodies operating worldwide for many years. The article presents the results of qualitative research (semi-structured interviews) among members of three types of social councils, i.e., youth councils, senior citizens’ councils, and councils for people with disabilities. The analysis included 46 interviews with their members conducted in selected cities with county (districts) rights in Poland.
Przywództwo w wielkich miastach – próba konceptualizacji
Authors: Baran Katarzyna , Mazur Stanisław
Published: February 2023

The aim of this article is to examine the multidimensional issue of urban leadership and to identify the key theoretical approaches in the study of this fascinating phenomenon. The importance of big cities in both the socioeconomic and political spheres is growing rapidly. The article discusses four leadership trends (political, systemic, community, and global), highlighting their key assumptions and characteristics. The author’s original way of organising deliberations on urban leadership constitutes an attempt to give structure to multithreaded theoretical research in this field
A Review of Working Fluids and Flow State Effects on Thermal Performance of Micro-Channel Oscillating Heat Pipe for Aerospace Heat Dissipation
Authors: Zhao Xiaohuan , Su Limin , Jiang Jiang , Deng Wenyu , Zhao Dan
Published: February 2023

A MCOHP (micro-channel oscillating heat pipe) can provide lightweight and efficient temperature control capabilities for aerospace spacecraft with a high power and small size. The research about the heat flow effects on the thermal performance of MCOHPs is both necessary and essential for aerospace heat dissipation. In this paper, the heat flow effects on the thermal performance of MCOHPs are summarized and studied. The flow thermal performance enhancement changes of MCOHPs are given, which are caused by the heat flow work fluids of nano-fluids, gases, single liquids, mixed liquids, surfactants, and self-humidifying fluids. The use of graphene nano-fluids as the heat flow work medium can reduce the thermal resistance by 83.6%, which can enhance the maximum thermal conductivity by 105%. The influences of gravity and flow characteristics are also discussed. The heat flow pattern changes with the work stage, which affects the flow mode and the heat and mass transfer efficiency of OHP. The effective thermal conductivity varies from 4.8 kW/(m·K) to 70 kW/(m·K) when different gases are selected as the working fluid in OHP. The study of heat flow effects on the thermal performance of MCOHPs is conducive to exploring in-depth aerospace applications.
Design and Experimental Study of a Novel Semi-Physical Unmanned-Aerial-Vehicle Simulation Platform for Optical-Flow-Based Navigation
Authors: Lin Zhonglin , Wang Weixiong , Li Yufeng , Zhang Xinglong , Zhang Tianhong , Wang Haitao , Wu Xianyu , Huang Feng
Published: February 2023

In the process of unmanned aerial vehicle (UAV) visual-navigation-algorithm design and accuracy verification, the question of how to develop a high-precision and high-reliability semi-physical simulation platform has become a significant engineering problem. In this study, a new UAV semi-physical-simulation-platform architecture is proposed, which includes a six-degree-of-freedom mechanical structure, a real-time control system and real-time animation-simulation software. The mechanical structure can realistically simulate the flight attitude of a UAV in a three-dimensional space of 4 × 2 × 1.4 m. Based on the designed mechanical structure and its dynamics, the control system and the UAV real-time flight-animation simulation were designed. Compared with the conventional simulation system, this system enables real-time flight-attitude simulation in a real physical environment and simultaneous flight-attitude simulation in virtual-animation space. The test results show that the repeated positioning accuracy of the three-axis rotary table reaches 0.006°, the repeated positioning accuracy of the three-axis translation table reaches 0.033 mm, and the dynamic-positioning accuracy reaches 0.04° and 0.4 mm, which meets the simulation requirements of high-precision visual UAV navigation.
Analyzing Emerging Challenges for Data-Driven Predictive Aircraft Maintenance Using Agent-Based Modeling and Hazard Identification
Authors: Lee Juseong , Mitici Mihaela , Blom Henk A. P. , Bieber Pierre , Freeman Floris
Published: February 2023

The increasing use of on-board sensor monitoring and data-driven algorithms has stimulated the recent shift to data-driven predictive maintenance for aircraft. This paper discusses emerging challenges for data-driven predictive aircraft maintenance. We identify new hazards associated with the introduction of data-driven technologies into aircraft maintenance using a structured brainstorming conducted with a panel of maintenance experts. This brainstorming is facilitated by a prior modeling of the aircraft maintenance process as an agent-based model. As a result, we identify 20 hazards associated with data-driven predictive aircraft maintenance. We validate these hazards in the context of maintenance-related aircraft incidents that occurred between 2008 and 2013. Based on our findings, the main challenges identified for data-driven predictive maintenance are: (i) improving the reliability of the condition monitoring systems and diagnostics/prognostics algorithms, (ii) ensuring timely and accurate communication between the agents, and (iii) building the stakeholders’ trust in the new data-driven technologies.
Epoxy-Functionalized POSS and Glass Fiber for Improving Thermal and Mechanical Properties of Epoxy Resins
Authors: Jiang Jianliang , Shen Jingbo , Yang Xiao , Zhao Dongqi , Feng Yakai
Published: February 2023

To improve the thermal and mechanical properties of epoxy resins, epoxy-functionalized POSS (E-POSS) and glass fiber (GF) were used to reinforce epoxy resin (E51) composites. The tensile, thermo-mechanical, fractured, and thermal tests were carried out to characterize these hybrid materials. The results show that E-POSS and GF could significantly improve the mechanical and thermal properties of epoxy resins due to high crosslink density of resin matrix and synergistic interaction between the epoxy resin, E-POSS, and GF. Compared with the pure E51 resin, the tensile strength of the E51 + E-POSS (10%) + GF (16%) sample increased by 257.6%, and the thermal decomposition temperature (Td5%) of the E51 + E-POSS (10%) + GF (16%) sample increased by 32 °C to 378 °C.
Grey-Box Fuzzing Based on Reinforcement Learning for XSS Vulnerabilities
Authors: Song Xuyan , Zhang Ruxian , Dong Qingqing , Cui Baojiang
Published: February 2023

Cross-site scripting (XSS) vulnerabilities are significant threats to web applications. The number of XSS vulnerabilities reported has increased annually for the past three years, posing a considerable challenge to web application maintainers. Black-box scanners are mainstream tools for security engineers to perform penetration testing and detect XSS vulnerabilities. Unfortunately, black-box scanners rely on crawlers to find input points of web applications and cannot guarantee all input points are tested. To this end, we propose a grey-box fuzzing method based on reinforcement learning, which can detect reflected and stored XSS vulnerabilities for Java web applications. We first use static analysis to identify potential input points from components (i.e., Java code, configuration files, and HTML files) of the Java web application. Then, an XSS vulnerability payload generation method is proposed, which is used together with the reinforcement learning model. We define the state, action, and reward functions of three reinforcement learning models for XSS vulnerability detection scenarios so that the fuzz loop can be performed automatically. To demonstrate the effectiveness of the proposed method, we compare it against four state-of-the-art web scanners. Experimental results show that our method finds all XSS vulnerabilities and has no false positives.
Ari Folman’s Made in Israel (2001): Traces of Trauma in the Israeli Cinema Landscape
Authors: Munk Yael
Published: February 2023

In the Israeli collective memory, the Yom Kippur’s battles in the Golan Heights have become synonymous with a long lasting national scar that fails to disappear. Interestingly, until the release of Yaron Zilberman’s recent television series Valley of Tears (She’at Ne’Ila, 2020), this war, which was traditionally associated with the pictured northern landscape, had appeared in few documentaries, but was almost absent from Israeli feature films. This article analyzes one of the very few attempts to deal with this memory, Ari Folman’s feature film Made in Israel (2001). Using a science fiction narrative structure, Folman adopts historian Anita Shapira’s contention about the link between this war and the Holocaust, because both confronted the Jewish people with its fear of extermination. His narrative invites the viewer to participate imaginatively in a road movie set against the snow-covered landscapes of the Golan Heights, where a number of hitmen attempt to catch the last surviving Nazi and bring him to trial in Jerusalem. Interestingly, what begins as a Zionist mission in the hegemonic spaces of the State of Israel gradually transforms into various European landscapes as the snow piles up and the Nazi feels increasingly at home.
On the Structure of Coisometric Extensions
Authors: Popovici Dan
Published: February 2023

If T is a bounded linear operator on a Hilbert space H and V is a given linear isometry on a Hilbert space K, we present necessary and sufficient conditions on T in order to ensure the existence of a linear isometry π:H→K such that πT=V*π (i.e., (π,V*) extends T). We parametrize the set of all solutions π of this equation. We show, for example, that for a given unitary operator U on a Hilbert space E and for the multiplication operator by the independent variable Mz on the Hardy space HD2(D), there exists an isometric operator π:H→E⊕HD2(D) such that (π,(U⊕Mz)*) extends T if and only if T is a contraction, the defect index δT≤dimD and, for some Y:AT→E, (Y,U*) extends the isometric operator AT1/2h↦AT1/2Th on the space AT=ATH¯, where AT is the asymptotic limit associated with T. We also prove that if T is isometric and V is unitary, there exists an isometric operator π:H→K such that (π,V) extends T if and only if (a) the spectral measures of the unitary part of T (in its Wold decomposition) and the restriction of V to one of its reducing subspaces K0 possess identical multiplicity functions and (b) dim(kerT*)=dim(K1⊖VK1) for a certain subspace K1 of K that contains K0 and is invariant under V. The precise form of π, in each situation, and characterizations of the minimality conditions are also included. Several examples are given for illustrative purposes.
Charge Storage Mechanism of LixWO3 Hexagonal Tungsten Bronze in Aqueous Electrolytes
Authors: Espinosa-Angeles Julio César , Quarez Eric , Mvele Eyé’a Louis-Béni , Douard Camille , Iadecola Antonella , Shao Hui , Taberna Pierre-Louis , Simon Patrice , Crosnier Olivier , Brousse Thierry
Published: February 2023

The electrochemical behavior of the lithium hexagonal tungsten bronze, LixWO3, is investigated herein. The material was synthesized at a low temperature under hydrothermal conditions, yielding nanorod-like particles with growth along the c-axis. Upon cycling in a 5 M LiNO3 aqueous electrolyte, a specific capacity of 71 C.g−1 was obtained at 2 mV.s−1, corresponding to a charge/discharge cycle of 10 min. The charge storage mechanism was elucidated using various complementary techniques, such as electrochemical quartz crystal microbalance (EQCM) and synchrotron operando X-ray absorption spectroscopy (XAS). A desolvation process upon Li+ intercalation into the lattice of the material was evidenced, accompanied by a reversible reduction/oxidation of tungsten cations in the crystal structure upon charge/discharge cycling.
Mesenchymal and Neural Stem Cell-Derived Exosomes in Treating Alzheimer’s Disease
Authors: Wang Hongmin , Huber Christa C. , Li Xiao-Ping
Published: February 2023

As the most common form of dementia and a progressive neurodegenerative disorder, Alzheimer’s disease (AD) affects over 10% world population with age 65 and older. The disease is neuropathologically associated with progressive loss of neurons and synapses in specific brain regions, deposition of amyloid plaques and neurofibrillary tangles, neuroinflammation, blood–brain barrier (BBB) breakdown, mitochondrial dysfunction, and oxidative stress. Despite the intensive effort, there is still no cure for the disorder. Stem cell-derived exosomes hold great promise in treating various diseases, including AD, as they contain a variety of anti-apoptotic, anti-inflammatory, and antioxidant components. Moreover, stem cell-derived exosomes also promote neurogenesis and angiogenesis and can repair damaged BBB. In this review, we will first outline the major neuropathological features associated with AD; subsequently, a discussion of stem cells, stem cell-secreted exosomes, and the major exosome isolation methods will follow. We will then summarize the recent data involving the use of mesenchymal stem cell- or neural stem cell-derived exosomes in treating AD. Finally, we will briefly discuss the challenges, perspectives, and clinical trials using stem cell-derived exosomes for AD therapy.
Bronchopulmonary Dysplasia in Extremely Premature Infants: A Scoping Review for Identifying Risk Factors
Authors: Ito Masato , Kato Shin , Saito Makoto , Miyahara Naoyuki , Arai Hirokazu , Namba Fumihiko , Ota Erika , Nakanishi Hidehiko
Published: February 2023

Background: Over the years, bronchopulmonary dysplasia (BPD) affects the pulmonary function of infants, resulting in chronic health burdens for infants and their families. The aim of this scoping review was to screen available evidence regarding perinatal risk factors associated with the development and severity of BPD. Methods: The eligibility criteria of the studies were year of publication between 2016 and 2021; setting of a developed country; English or Japanese as the study language; and randomized controlled, cohort, or case-control design. The titles and abstracts of the studies were screened by independent reviewers. Results: Of 8189 eligible studies, 3 were included for severe BPD and 26 were included for moderate BPD. The risk factors for severe BPD were male sex, iatrogenic preterm birth, maternal hypertensive disorders of pregnancy (HDP), low gestational age, small-for-gestational-age (SGA) birth weight, mechanical ventilation on day 1, and need for patent ductus arteriosus (PDA) management. The risk factors for moderate or severe BPD included male sex, premature rupture of membranes, clinical chorioamnionitis, maternal HDP, SGA birth weight, bubbly/cystic appearance on X-ray, and PDA management. Conclusions: We identified several risk factors for BPD. We plan to confirm the validity of the new classification using the existing dataset.
No Association between Gastrointestinal Rebleeding and DOAC Therapy Resumption: A Systematic Review and Meta-Analysis
Authors: Pálinkás Dániel , Teutsch Brigitta , Gagyi Endre Botond , Engh Marie Anne , Kalló Patrícia , Veres Dániel S. , Földvári-Nagy László , Hosszúfalusi Nóra , Hegyi Péter , Erőss Bálint
Published: February 2023

Background: There are recommendations for anticoagulation resumption after gastrointestinal bleeding (GIB), although data addressing this topic by direct oral anticoagulants (DOACs)-treated patients is lacking. We aim to determine the safety and efficacy of restarting DOACs after GIB. Methods: Studies that reported rebleeding, thromboembolic events, and mortality after restarting or withholding DOACs were selected. The systematic research was conducted in five databases (MEDLINE, EMBASE, CENTRAL, Web of Science, and Scopus). The random effect model was implemented to calculate the pooled odds ratio (OR). The ROBINS-I tool was used for risk of bias assessment, and the certainty of the evidence was evaluated with the GRADE approach. Results: Four retrospective cohort studies (1722 patients) were included in the meta-analysis. We did not find a significant increase in the risk of rebleeding in patients restarting DOACs after index GIB (OR = 1.12; 95% CI: 0.74–1.68). The outcomes of thromboembolic events and mortality data were not suitable for meta-analytic calculations. Single studies did not show statistically significant differences. Data quality assessment showed a serious overall risk of bias and very low quality of evidence (GRADE D). Conclusion: DOAC resumption after a GIB episode may not elevate the risk of rebleeding. However, the need for high-quality randomized clinical trials is crucial.
Biomedical Advances in ABCA1 Transporter: From Bench to Bedside
Authors: Choi Hong Y. , Choi Senna , Iatan Iulia , Ruel Isabelle , Genest Jacques
Published: February 2023

ATP-binding cassette transporter A1 (ABCA1) has been identified as the molecular defect in Tangier disease. It is biochemically characterized by absence of high-density lipoprotein cholesterol (HDL-C) in the circulation, resulting in the accumulation of cholesterol in lymphoid tissues. Accumulation of cholesterol in arteries is an underlying cause of atherosclerosis, and HDL-C levels are inversely associated with the presence of atherosclerotic cardiovascular disease (ASCVD). ABCA1 increases HDL-C levels by driving the generation of new HDL particles in cells, and cellular cholesterol is removed in the process of HDL generation. Therefore, pharmacological strategies that promote the HDL biogenic process by increasing ABCA1 expression and activity have been intensively studied to reduce ASCVD. Many ABCA1-upregulating agents have been developed, and some have shown promising effects in pre-clinical studies, but no clinical trials have met success yet. ABCA1 has long been an attractive drug target, but the failed clinical trials have indicated the difficulty of therapeutic upregulation of ABCA1, as well as driving us to: improve our understanding of the ABCA1 regulatory system; to develop more specific and sophisticated strategies to upregulate ABCA1 expression; and to search for novel druggable targets in the ABCA1-dependent HDL biogenic process. In this review, we discuss the beginning, recent advances, challenges and future directions in ABCA1 research aimed at developing ABCA1-directed therapies for ASCVD.
A Panel of Circulating Non-Coding RNAs in the Diagnosis and Monitoring of Therapy in Egyptian Patients with Breast Cancer
Authors: Wehida Nadine , Abdel-Rehim Wafaa , El Mansy Hazem , Karmouty Ahmed , Kamel Maher A.
Published: February 2023

Background: Non-coding RNAs (ncRNAs) have recently been identified to have a pivotal role in many diseases, including breast cancer (BC). This study aims to investigate the relative quantification of long non-coding RNA (lncRNA) H19, microRNA (miR) 675-5p, 675-3p, and miR-let 7 in breast cancer patients. Methods: The study was performed on three groups: Group 1: 30 non-intervened BC female patients about to undergo breast surgery; group 2: 30 postoperative female BC patients about to receive adjuvant anthracycline chemotherapy; and group 3: 30 apparently healthy female volunteers as the control group. Plasma samples were drawn before and after the intervention in groups 1 and 2, with a single sample drawn from group 3. The relative quantification levels were compared with healthy control subjects and were related with the clinicopathological statuses of these patients. Results: There was a statistically significant increase in H19, miR-675-5p, miR-675-3p, and miR-let 7 in the non-intervened BC patients when compared to the control group. Surgery resulted in a significant reduction in all four ncRNAs under investigation. Chemotherapy brought about a significant increase in the level of miR-let 7, with no significant effect on the remaining parameters measured. The assay discriminated normal from BC where a receiver operating characteristic for the area under the curve (ROCAUC) of miR-675-3p showed the maximal AUC of 1.000. The diagnostic sensitivity and specificity were also 100% when CA 15-3 and H19 were combined. Conclusion: The results strongly indicate that the panel of ncRNAs in this study can all potentially act as novel biomarkers whether alone or combined in the diagnosis of BC.
The Effect of a Digital Manufacturing Technique, Preparation Taper, and Finish Line Design on the Marginal Fit of Temporary Molar Crowns: An In-Vitro Study
Authors: Mugri Maryam H. , Dewan Harisha , Sayed Mohammed E. , Shaabi Fawzia Ibraheem , Hakami Hanan Ibrahim , Jokhadar Hossam F. , Alqahtani Nasser M. , Alshahrani Ahid Amer , Alabdullah Abdullah S. , Alshehri Abdullah Hasan , Wadei Mohammed Hussain Dafer Al , Arif Fatimah Yahya , Adawi Ebtihag H. , Al-Makramani Bandar M. A. , Chohan Hitesh
Published: February 2023

The aim of this study is to investigate the combined effect of a digital manufacturing technique (subtractive vs. additive), preparation taper (10° vs. 20° TOC), and finish line (chamfer vs. shoulder) on the marginal adaptation of temporary crowns following cementation with a compatible temporary cement. Four mandibular first molar typodont teeth were prepared for full coverage crowns with standard 4 mm preparation height as follows: 10° TOC with the chamfer finish line, 10° TOC with the shoulder finish line, 20° TOC with the chamfer finish line and 20° TOC with the shoulder finish line. Each of the four preparation designs were subdivided into two subgroups to receive CAD/CAM milled and 3D-printed crowns (n = 10). A total of 80 temporary crowns (40 CAD/CAM milled and 40 3D-printed) were cemented to their respective die using clear temporary recement in the standard cementation technique. The samples were examined under a stereomicroscope at ×100 magnification following calibration. Linear measurements were performed at seven equidistant points on each axial surface and five equidistant points on each proximal surface. One-way ANOVA analysis and Tukey HSD (Honestly Significance Difference) were performed. The best marginal fit was seen in group 8, while the poorest fit was noted in group 2. Shoulder finish lines and 10° TOC resulted in higher marginal gaps, especially in CAD/CAM milled group. The selection of 3D-printed crowns may provide a better marginal fit within the range of clinical acceptability. Marginal gaps were within clinical acceptability (50 and 120 µm) in all groups except group 2.
Soft Robotic Glove with Sensing and Force Feedback for Rehabilitation in Virtual Reality
Authors: Li Fengguan , Chen Jiahong , Ye Guanpeng , Dong Siwei , Gao Zishu , Zhou Yitong
Published: February 2023

Many diseases, such as stroke, arthritis, and spinal cord injury, can cause severe hand impairment. Treatment options for these patients are limited by expensive hand rehabilitation devices and dull treatment procedures. In this study, we present an inexpensive soft robotic glove for hand rehabilitation in virtual reality (VR). Fifteen inertial measurement units are placed on the glove for finger motion tracking, and a motor—tendon actuation system is mounted onto the arm and exerts forces on fingertips via finger-anchoring points, providing force feedback to fingers so that the users can feel the force of a virtual object. A static threshold correction and complementary filter are used to calculate the finger attitude angles, hence computing the postures of five fingers simultaneously. Both static and dynamic tests are performed to validate the accuracy of the finger-motion-tracking algorithm. A field-oriented-control-based angular closed-loop torque control algorithm is adopted to control the force applied to the fingers. It is found that each motor can provide a maximum force of 3.14 N within the tested current limit. Finally, we present an application of the haptic glove in a Unity-based VR interface to provide the operator with haptic feedback while squeezing a soft virtual ball.
Anatomic Region of Cutaneous Melanoma Impacts Survival and Clinical Outcomes: A Population-Based Analysis
Authors: Shannon Christian M. , Mehta Neil K. , Li Hong , Nguyen Shaun A. , Koochakzadeh Sina , Elston Dirk M. , Kaczmar John M. , Day Terry A.
Published: February 2023

Purpose: The objective was to determine the effects of the anatomic site of a cutaneous melanoma on the survival outcomes of diagnosed individuals. Methods: We conducted a cross-sectional study using data from the Surveillance, Epidemiology, and End Results Program (SEER) Database from 2004–2014 and included 178,892 cases of individuals diagnosed with cutaneous melanoma. Overall survival (OS) for each anatomic site as well as associated demographics, primary site, stage, and pathologic prognostic factors (Breslow’s depth of invasion (DOI), level of mitoses, and ulceration), were analyzed. Results: Lower extremity melanoma (LEM) was the most likely to have locoregional nodal spread, yet head and neck melanoma (HNM) was the most likely to present at the most advanced stage of disease (IV). Independent of other factors, HNM was associated with the greatest risk of death (HR 1.90 [95% CI, 1.85–1.96]) compared to other sites, and males experienced worse overall survival (OS) (HR 1.74 [95% CI, 1.70–1.78]) compared to females. The last and greatest risk of death is associated with LEM and HNM, respectively. Conclusion: Given these survival differences, consideration should be given to incorporating the primary site of melanoma into staging to ensure treatment is efficacious as possible.
Effects of Low-Level Laser Therapy on Orthodontic Tooth Movement: Evaluation of Bony Changes via 3DCBCT
Authors: Alam Mohammad Khursheed
Published: February 2023

Objective: The prime objective of this research was to study the effect of low-level laser therapy (LLLT) with an evaluation of bony changes via pre- and post-treatment 3DCBCT in orthodontic malocclusion cases treated with fixed orthodontic appliances. Materials and Methods: Subjects who attended the Orthodontic Clinic, were diagnosed with orthodontic malocclusion, treated with fixed orthodontic appliances, and had pre- and post-management CBCT were included in the study. Patients aged 14 to 25 years who met the inclusion criteria were assigned to two groups, group A (LLLT) and group B (non-LLLT). Group A participants were treated with LLLT therapy as per standard protocol after explaining the nature of the treatment. Group B (non-LLLT) participants were not treated with LLLT therapy and therefore served as the control. LLLT was used in the experimental group after placing each archwire. Interradicular bony changes at depth levels of 1 to 4 (2, 5, 8, and 11 mm) using 3DCBCT were measured as outcome parameters. Results: The information collected was analyzed using SPSS computer software. Mostly insignificant differences were noted among groups for the different parameters (p < 0.05). Student’s t-tests and paired t-tests were used to investigate the differences. Experimental Hypothesis: There will be significant differences in the interradicular width (IRW) measurements between the LLLT and non-LLLT groups. Conclusions: The hypothesis was rejected. Upon investigation of prospective changes, most of the measured parameters showed insignificant differences.
Performance Analysis of SiGe-Cladded Silicon MMI Coupler in Presence of Stress
Authors: Kumari Sneha , Pathak Akhilesh Kumar , Gangwar Rahul Kumar , Gupta Sumanta
Published: February 2023

In this study, we demonstrate the influence of operating temperature variation and stress-induced effects on a silicon-on-insulator (SOI)-based multi-mode interference coupler (MMI). Here, SiGe is introduced as the cladding layer to analyze its effect on the optical performance of the MMI coupler. SiGe cladding thickness is varied from 5 nm to 40 nm. Characterization of the MMI coupler for ridge waveguides with both rectangular and trapezoidal sidewall slope angle cross-sections is reviewed in terms of power splitting ratio and birefringence. Stress-induced birefringence as a function of operating temperature and cladding thickness for fundamental mode have been calculated. A trapezoidal waveguide with 40 nm of cladding thickness induces more stress and, therefore, affects birefringence more than a rectangular waveguide of any thickness. Simulation results using the finite element method (FEM) confirmed that operating temperature variation, upper cladding thickness, and its stress effect are significant parameters that drastically modify the performance of an MMI coupler.
Algorithm for Determining Three Components of the Velocity Vector of Highly Maneuverable Aircraft
Authors: Pavlikov Volodymyr , Tserne Eduard , Odokiienko Oleksii , Sydorenko Nataliia , Peretiatko Maksym , Kosolapova Olha , Prokofiiev Ihor , Humennyi Andrii , Belousov Konstantin
Published: February 2023

We developed a signal processing algorithm to determine three components of the velocity vector of a highly maneuverable aircraft. We developed an equation of the distance from an aircraft to an underlying surface. This equation describes a general case of random spatial aircraft positions. Particularly, this equation considers distance changes according to an aircraft flight velocity variation. We also determined the relationship between radial velocity measured within the radiation pattern beam, the signal frequency Doppler shift, and the law of the range changing within the irradiated surface area. The models of the emitted and received signals were substantiated. The proposed equation of the received signal assumes that a reflection occurs not from a point object, but from a spatial area of an underlying surface. It fully corresponds to the real interaction process between an electromagnetic field and surface. The considered solution allowed us to synthesize the optimal algorithm to estimate the current range and three components {Vx,Vy,Vz} of the aircraft’s velocity vector V→. In accordance with the synthesized algorithm, we propose a radar structural diagram. The developed radar structural diagram consists of three channels for transmitting and receiving signals. This number of channels is necessary to estimate the full set of the velocity and altitude vector components. We studied several aircraft flight trajectories via simulations. We analyzed straight-line uniform flights; flights with changes in yaw, roll, and attack angles; vertical rises; and landings on a glide path and lining up with the correct yaw, pitch, and roll angles. The simulation results confirmed the correctness of the obtained solution.
Skin Capacitive Image Stitching and Occlusion Measurements
Authors: Ciortea Lorelai I. , Chen Daqing , Xiao Perry
Published: February 2023

The aim of this study is to develop new analysis techniques for skin capacitive image stitching and occlusion measurements. Through image stitching, small skin capacitive images can be stitched into large skin capacitive images and, therefore, provide more skin image information. Through occlusion, e.g., keeping the measurement device on skin for a period of time, the skin health status can be studied through time-dependent response curves. Results show that time-dependent skin capacitive imaging curves can tell us the information about transdermal water loss (TEWL) as well as skin surface profiles. By using the structural similarity index measure (SSIM), the TEWL map can be constructed, which shows the water loss map on the skin surface. We first present the theoretical background and then the experimental results.
High-Fidelity Dynamics Modelling for the Design of a High-Altitude Supersonic Sounding Rocket
Authors: Milne Benjamin , Samson Sean , Carrese Robert , Gardi Alessandro , Sabatini Roberto
Published: February 2023

The accurate modelling and simulation of vehicle dynamics is a fundamental prerequisite for the design and experimental flight testing of aerospace vehicles. In the case of high-altitude supersonic sounding rockets, it is critically important to produce realistic trajectory predictions in a representative range of operational and environmental conditions as well as to produce reliable probability distributions of terminal locations. This article proposes a methodology to develop high-fidelity flight dynamics models that accurately capture aeroelastic, turbulence, atmospheric and other effects relevant to sounding rockets. The significance of establishing a high-fidelity model and of addressing such a problem in the context of developing a digital twin are discussed upfront, together with the key tools utilised in the analysis. In addition to state-of-the-art computational methods to determine the aerodynamic forces, moments and mass changes in various flight regimes (including parachute release), a detailed methodology for incorporating the dynamic aeroelastic response of the rocket is presented. The validity of the proposed method is demonstrated through a simulation case study, which utilises data from an existing rocket prototype. Results corroborate the correct implementation of the proposed algorithms and provide foundations for future research on virtual sensing and digital twin for autonomous navigation and guidance.
Influence of Thermochemical Conversion Technologies on Biochar Characteristics from Extensive Grassland for Safe Soil Application
Authors: Heinrich Thomas , Kaetzl Korbinian , Libra Judy A. , Hoffmann Thomas
Published: February 2023

Grass and other herbaceous biomass are abundant, but often under- or not utilized as a renewable resource. Here, the production of biochar from extensive late-harvest grass via multiple thermochemical conversion technologies was investigated at lab and farm scale for use in soil applications. While biochar is a product with highly diverse potential applications, it has a multitude of benefits for agricultural usage as a soil amendment, if the quality adheres to certain limit values of potentially toxic constituents. The results show that the biochar can adhere to all limit values of the European Biochar Certificate (EBC) for utilization in agriculture. Generally, the contents of heavy metals were well below the proposed EBC limits and very low PAH concentrations in the biochar were achieved. The high ash content in the grass of 7.71 wt%db resulted in high nutrient concentrations in the biochar, of benefit in soil applications, but the ash also contains chlorine, nitrogen and sulphur, which presents a challenge for the operation of the thermochemical processes themselves due to corrosion and emission limits. In the farm-scale processes, ash retention ranged from 53.7 wt%db for an autothermal batch process, reaching up to 93.7 wt%db for a batch allothermal process. The release of Cl, N and S was found to differ substantially between processes. Retention ranged from 41.7%, 22.9% and 27.6%, respectively, in a continuous allothermal farm-scale pyrolysis process, to 71.7%, 49.7% and 73.9%, with controlled lab-scale pyrolysis at 450 °C, demonstrating that process optimization may be possible.
Sector Coupling and Migration towards Carbon-Neutral Power Systems
Authors: Son Minjae , Kim Minsoo , Kim Hongseok
Published: February 2023

There is increasing interest in migrating to a carbon-neutral power system that relies on renewable energy due to concerns about greenhouse gas emissions, energy shortages, and global warming. However, the increasing share of renewable energy has added volatility and uncertainty to power system operations. Introducing new devices and using flexible resources may help solve the problem, but expanding the domain of the problem can be another solution. Sector coupling, which integrates production, consumption, conversion, and storage by connecting various energy domains, could potentially meet the needs of each energy sector. It can also reduce the generation of surplus energy and unnecessary carbon emissions. As a result, sector coupling, an integrated energy system, increases the acceptance of renewable energy in the traditional power system and makes it carbon neutral. However, difficulties in large-scale integration, low conversion efficiency and economic feasibility remain obstacles. This perspective paper discusses the background, definition, and components of sector coupling, as well as its functions and examples in rendering power systems carbon-neutral. The current limitations and outlook of sector coupling are also examined.
A Fractional Order Controller for Sensorless Speed Control of an Induction Motor
Authors: Nosheen Tayyaba , Ali Ahsan , Chaudhry Muhammad Umar , Nazarenko Dmitry , Shaikh Inam ul Hasan , Bolshev Vadim , Iqbal Muhammad Munwar , Khalid Sohail , Panchenko Vladimir
Published: February 2023

Agriculture activities are completely dependent upon energy production worldwide. This research presents sensorless speed control of a three-phase induction motor aided with an extended Kalman filter (EKF). Although a proportional integral (PI) controller can ensure tracking of the rotor speed, a considerable magnitude of ripples is present in the torque generated by a motor. Adding a simple derivative to have a proportional integral derivative (PID) action can cause a further increase in ripple magnitude, as it allows the addition of high-frequency noise in the system. Therefore, a fractional-order-based PID control is presented. The proposed control scheme is applied in a closed loop with the system, and simulation results are compared with the PID controller. It is evident from the results that the fractional order control not only ensures 20 times faster tracking, but ripple magnitude in torque was also reduced by a factor of 50% compared to that while using PID and ensures the effectiveness of the proposed strategy.
Fulfillment of EU Goals in the Field of Waste Management through Energy Recovery from Waste
Authors: Tauš Peter , Šimková Zuzana , Cehlár Michal , Krajňáková Ivana , Drozda Július
Published: February 2023

Is it really necessary for the more than 200 million tons of municipal waste produced by the EU to end up in landfills? Nowadays, there are many methods for using the raw materials and energy potential of waste in ways that are economical and environmentally acceptable. But first it is necessary to understand what waste is being produced, the possibilities for recycling, and the amount of waste deposited in landfills. Many studies show that, with the ever-increasing standard of living, which is accompanied by increasing consumption as well as increasing waste production, increasing separation of waste is a positive trend. However, it is essential to realize that many materials cannot be recycled indefinitely. Therefore, in our research, we focused on reducing the share of waste that goes into landfill with the goal of zero waste to landfill, so as to increase recycling and the amount of energy obtained from waste. We focused on the analysis of waste production in individual EU states, using the available data for the years 1995–2019. For a more detailed analysis, EU countries were evaluated in terms of individual waste management processes, according to available statistical data. We found that Switzerland, Germany, Sweden, Belgium, the Netherlands, Norway, Denmark, and Austria put the least amount of waste into landfills, which means that they obtain the most energy and raw materials from waste.
A Review on Fullerene Derivatives with Reduced Electron Affinity as Acceptor Materials for Organic Solar Cells
Authors: Mumyatov Alexander V. , Troshin Pavel A.
Published: February 2023

Organic solar cells (OSCs) represent a promising emerging photovoltaic technology offering such benefits as light weight, mechanical flexibility, semitransparency, environmental friendliness and aesthetic design of solar panels. Furthermore, organic solar cells can be produced using scalable and high-throughput solution-based printing and coating technologies, which are expected to lead to very low product costs. Fullerene derivatives have been used as acceptor materials in virtually all efficient organic solar cells for more than two decades, following the demonstration of the first proof-of-concept devices in the middle of 1990s. Still, the power conversion efficiencies of fullerene-based organic solar cells became stuck at around 12% due to the suboptimal optoelectronic properties of conventional fullerene acceptors. Therefore, the latest efficiency records (>18%) for organic solar cells were set using different types of non-fullerene acceptor (NFA) materials with tailorable properties. However, NFA materials appeared to be very sensitive to light, thus impairing the operational stability of OSCs. On the contrary, there is growing evidence that rationally designed fullerene-based acceptors enhance the photostability of conjugated polymers and also NFAs, when used in ternary blends. Hence, a renaissance of fullerene-based materials is currently expected in the context of their use in multicomponent organic solar cells (e.g., as stabilizers) and also lead halide perovskite solar cells, where they play an important role of electron transport materials. The success in both of these applications requires the tunability of optoelectronic characteristics of fullerene derivatives. In particular, electron affinity of the fullerene cage has to be reduced in many cases to match the energy levels of other absorber material(s). Herein, we present a systematic review of different strategies implemented to reduce the acceptor strength of the fullerene derivatives and the results of their performance evaluation in OSCs with model conjugated polymers. Particular attention is paid to correlations between the chemical structure of organic addends and their influence on the electronic properties of the fullerene core. We believe this review would be valuable to researchers working on the rational design of new fullerene-based materials with tailored properties for photovoltaic and other electronic applications.
Sizing Design for a Hybrid Renewable Power System Using HOMER and iHOGA Simulators
Authors: Hoarcă Ioan Cristian , Bizon Nicu , Șorlei Ioan Sorin , Thounthong Phatiphat
Published: February 2023

In this study, a comparative sizing design for renewable power systems was developed based on HOMER (Hybrid Optimization of Multiple Energy Resources) and iHOGA (improved Hybrid Optimization by Genetic Algorithms) simulators. A comparative analysis of the solutions obtained with iHOGA and HOMER simulators for the same hybrid renewable power system (HRPS) is presented in detail. The system contained a new hybrid configuration that used fuel cell (FC) as a green energy source, replacing the polluting diesel generator system, as well as other renewable energy sources, namely, photovoltaic panels, wind turbine, a battery stack, power converters, and electric load. The same case study was carried out for the design of the hybrid system using HOMER and iHOGA simulators to perform a comparative analysis of the solutions obtained for potential investment. The analysis showed a higher share of renewable energy for iHOGA (92%) compared to HOMER (81%), so the first design produced 51.61 kg/year less carbon dioxide. Moreover, the operating costs (2134 RON/year for HOMER and 70.56 RON/year for iHOGA) and the cost of electricity were higher by 96% and 2.5%, respectively, for HOMER compared to iHOGA. Taking into account the need for high reliability, safe operation, and lower operation/exploitation costs, the design implemented in iHOGA is clearly more efficient and useful in practice, and this is supported by the three iHOGA case studies.
The Barriers Analysis for Waste-to-Energy Project Development in Thailand: Using an Interpretive Structural Modeling Approach
Authors: Jaisue Nitad , Ketjoy Nipon , Kaewpanha Malinee , Thanarak Prapita
Published: February 2023

Waste-to-energy (WtE) is national policy. From this view, WtE technology has been promoted. Many WtE projects in Thailand were unsuccessful due to several problems. This research aimed to analyze the key barriers impacting the WtE project development in Thailand. The Interpretive Structural Model (ISM) and Cross-Impact Matrix Multiplication Applied to Classification (MICMAC) analysis tool have been used to evaluate the barriers that significantly in the development of WtE projects. In this study, WtE projects focused on electricity power generation in order to correspond to the Alternative Energy Development Plan (AEDP) target and power purchase agreement constrain of the government. The barriers were obtained from six sections consisting of social issues, environment, national policy, technology, economy, and project management. From six sections, there are 20 barriers that were identified. The ISM and MICMAC analysis showed that the key barriers impacting the WtE projects development were insufficient amount of waste and poor waste management planning. These two barriers correspond with many studies in Thailand and other countries. The project developers or investors must take these two barriers and other barriers with less impact mentioned in this study into account before developing the WtE projects in Thailand.
Effective and Efficient DDoS Attack Detection Using Deep Learning Algorithm, Multi-Layer Perceptron
Authors: Ahmed Sheeraz , Khan Zahoor Ali , Mohsin Syed Muhammad , Latif Shahid , Aslam Sheraz , Mujlid Hana , Adil Muhammad , Najam Zeeshan
Published: February 2023

Distributed denial of service (DDoS) attacks pose an increasing threat to businesses and government agencies. They harm internet businesses, limit access to information and services, and damage corporate brands. Attackers use application layer DDoS attacks that are not easily detectable because of impersonating authentic users. In this study, we address novel application layer DDoS attacks by analyzing the characteristics of incoming packets, including the size of HTTP frame packets, the number of Internet Protocol (IP) addresses sent, constant mappings of ports, and the number of IP addresses using proxy IP. We analyzed client behavior in public attacks using standard datasets, the CTU-13 dataset, real weblogs (dataset) from our organization, and experimentally created datasets from DDoS attack tools: Slow Lairs, Hulk, Golden Eyes, and Xerex. A multilayer perceptron (MLP), a deep learning algorithm, is used to evaluate the effectiveness of metrics-based attack detection. Simulation results show that the proposed MLP classification algorithm has an efficiency of 98.99% in detecting DDoS attacks. The performance of our proposed technique provided the lowest value of false positives of 2.11% compared to conventional classifiers, i.e., Naïve Bayes, Decision Stump, Logistic Model Tree, Naïve Bayes Updateable, Naïve Bayes Multinomial Text, AdaBoostM1, Attribute Selected Classifier, Iterative Classifier, and OneR.
Genetics and Biotechnology—The Section Editor-in-Chief’s View
Authors: Hallerman Eric M.
Published: February 2023

Genetics and biotechnology make increasingly important contributions to fishery science, fishery management, aquaculture, and related fields [...]