bluuebunny/crossref_metadata_2025_split huggingface dataset:
INTERMODULATION MEASUREMENT
Authors: Abuelma'atti Muhammad T. 
Published: December 2024

AbstractWhenever a number of signals of differing frequencies pass through a nonlinear device, energy is transferred to frequencies that are sums and differences of the original frequencies, that is, intermodulation products. This article presents a simple intermodulation theory and discusses its limitations and extensions. Methods of characterizing and measuring the intermodulation performance of nonlinear devices are presented, and their merits and demerits are discussed.
VOLTAGE‐TO‐FREQUENCY CONVERTERS
Authors: Vidal‐Verdú Fernando , Navas‐González Rafael , Delgado‐Restituto Manuel , Rodríguez‐Vázquez Angel 
Published: December 2024

AbstractVoltage‐to‐frequency converters (VFCs) typically employ relaxation oscillators to generate an output signal whose frequency depends linearly on an input voltage. VFCs are data converters; that is, they are designed to codify the input voltage by means of the output frequency. Hence, they have strong requirements regarding linearity, dynamic range, and stability. On the other hand, compared to other converters, they have the advantage of low cost, particularly for large resolutions; 13‐bit resolution is typical, and more than 20 bits are feasible. However, in such a case, several milliseconds may be necessary to complete the conversion—the smaller the resolution, the shorter the conversion time.The serial frequency modulated output provided by VFCs is particularly well suited for telemetry, to send the outcome of a measurement by wire, radio, or fiber optic links. After the frequency‐modulated signal is received, it can be easily codified into a digital word, or converted back into a voltage by a frequency‐to‐voltage converter (FVC). This type of output simplifies galvanic isolation through the use of either an optocoupler or a magnetic coupler.This chapter deals first with the concepts behind voltage‐to‐frequency conversion and then describes the main types of VFCs on the market, their limitations, and main applications. FVCs are also briefly described in the chapter.
SAFETY OF RF ENERGY TO HUMANS
Authors: Foster Kenneth R. 
Published: December 2024

AbstractThis article reviews considerations related to exposure assessment and biological effects of radiofrequency energy with emphasis on health and safety. The rationale for two major exposure limits is described. Major areas of controversy about health effects of low‐level radiofrequency energy are described, both as related to uncertainties in the scientific data and in large variations in exposure limits around the world.
MULTIPHYSICS MODELING WITH COMPUTATIONAL ELECTROMAGNETICS
Authors: Jin Jian‐Ming , Yan Su 
Published: December 2024

AbstractAs computational methods for solving Maxwell's equations become rather mature, the time has come to tackle much more challenging multiphysics problems, which have a great range of applications in science and technology. In this chapter, we use four examples to illustrate the challenges and resolutions of multiphysics modeling. The first example is related to electromagnetic hyperthermia for cancer treatment, which requires solving electromagnetic and bioheat transfer equation for the planning and optimization of the treatment process. The second example concerns the heat problem in integrated circuits due to electromagnetic dissipated power and its effects and a potential cooling solution, which requires an electrical–thermal–fluid–mechanical co‐simulation. The third example considers modeling of monolithic microwave integrated circuits, which consist of both distributive and lumped circuit components. The fourth example simulates the air and dielectric breakdown in high‐power microwave devices by coupling electromagnetic modeling with various plasma models. With these examples, we discuss in detail some of the technical challenges typically encountered in multiphysics modeling and their potential solutions.
HIGH‐POWER MICROWAVE SOURCES
Authors: Prasad Sarita 
Published: December 2024

AbstractHigh‐power microwave (HPM) sources are at the heart of an HPM‐directed energy weapons (DEWs) system. Based on recent defense news articles seen in online magazines such asThe Warzone, it is becoming more and more apparent that in the future the survival of a nation may depend on its DEW capability.This chapter provides a brief synopsis of a wide range of microwave tubes which are used for the generation of HPM signals. The chapter starts with a brief introduction on DEWs and their applications followed by a discussion on the basic building blocks of an HPM system. The sections that follow contain generalized physics of operation, frequency range, and output power capability of the following HPM tubes: magnetrons, backward wave oscillators (BWOs), klystrons, traveling wave tubes (TWTs), gyrotrons, virtual cathode oscillators (VCOs), magnetically insulated line oscillators (MILOs), transit time oscillators (TTOs), split cavity oscillators (SCOs), and reltrons. Of all the microwave tubes, the magnetron has been discussed in a little more detail because of its rich history. References have been provided for readers who wish to gain further knowledge in each area.
Tuning Hydrophilic Segments to Achieve Acid‐Free Proton Conduction in COF
Authors: Zhang Kun , Wu Lei , Zhang Yanting , Zhang Hong , Wu Dongshuang 
Published: December 2024

Comprehensive SummaryRapid dynamics and remarkable proton conduction induced by confined water in nanospaces have attracted much attentions from researchers, which is crucial for advancing the development of innovative proton conductors and deepening comprehension of proton and water transport mechanisms within biological systems. In this aspect, carbon nanotubes (CNTs) are frequently employed as a research platform. However, they possess certain limitations, such as their inherent electronic conductivity and extreme hydrophobicity, which can impede the accurate assessment and precise regulation of proton conduction. We herein prepared two 2D COFs with different hydrophilic fragment, and obtained maximum acid‐free proton conductivity of 3.04 × 10–4 S·cm–1 at 70 °C and 100% RH with Grotthuss type activation energy of 0.14 eV. This is mainly due to that the water molecules in the center of channel form strong hydrogen bonds, enhancing proton dissociation and guiding fast directional diffusion.
Alternating and Pulsed Current Electrolysis for Atom Transfer Radical Polymerization
Authors: De Bon Francesco , Vaz Simões Alexandre , Serra Armenio C. , Coelho Jorge F. J. 
Published: December 2024

AbstractThis concept focuses on the application of alternating current (AC) and pulsed electrolysis in Atom Transfer Radical Polymerization (ATRP) for polymer synthesis. AC electrolysis, which oscillates between reduction and oxidation, can be tuned to increase selectivity for a specific reaction pathway, minimize side reactions, and improve product selectivity and reagent conversion. Pulsed electrolysis can also be used to sustain electrochemical reactions in ATRP. The challenges and limitations associated with AC electrolysis are discussed along with an outlook on future developments in polymer synthesis and related applications. A concise overview of recent developments in electro‐organic synthesis using AC electrolysis will be provided.
What lessons, if any, do students infer from their studies of the Holocaust?
Authors: Nuttall Dan 
Published: December 2024

AbstractThis paper reports on a study analysing the lessons that 15 A Level (aged 17–18) students inferred from their studies of the Holocaust. All the participants had studied the Holocaust at an advanced level. The participants were interviewed in small groups (three to five participants), with the transcriptions of those interviews being iteratively coded, adopting an inductive grounded theory approach. Results were highly varied, with many different types of lessons being considered, though the most common concerned antiracist lessons, lessons about state systems and lessons about human nature. There was a tendency amongst participants to focus less on moral/deontological lessons from the Holocaust, and more on ontological lessons. Participants independently identified the types of lessons that Holocaust education organisations (IHRA, 2022) and some theorists (Short, 1999, 2003) suggested/hoped that they might. The small sample size and dominance of certain participants should be noted as barriers to the generalisability of the findings reported here.
Flow cytometry‐based method to detect and separate Mycoplasma hyorhinis in cell cultures
Authors: Liu Chunzhuo , Wang Hui , Liu Shan , Li Mengyuan 
Published: December 2024

AbstractMycoplasma hyorhinis is a frequently observed contaminant in cell cultures, and its detection and purification pose considerable challenges. Fragments or other cell components are similar in size to those of Mycoplasma; therefore, distinguishing them is difficult. In this study, we used Hoechst staining in combination with carboxyfluorescein succinimidyl ester (CFSE) to label Mycoplasma. The trigger threshold was set in the Hoechst Blue channel rather than in the default forward scatter channel, utilizing the differences in DNA content between Mycoplasma and fragments. Subsequently, we identified and isolated it at single‐cell resolution via flow cytometry and successfully sorted infectious Mycoplasma in cell culture. Simultaneously, we validated the accuracy and feasibility of this approach using polymerase chain reaction, fluorescence confocal microscopy, and cryo‐electron microscopy. This methodology enabled the diagnosis of Mycoplasma at extremely low concentrations, significantly enhancing the detection efficiency and facilitating the isolation and purification of parasitic Mycoplasma in cell culture instead of pure Mycoplasma culture in artificial media for subsequent studies.
Diuretic efficiency of a single dose of subcutaneous versus oral furosemide after heart failure hospitalization across diuretic resistance strata: A pilot randomized controlled trial
Authors: Keshvani Neil , Rizvi Syed , Segar Matthew W. , Miller James W. , Coellar Juan David , Patel Kershaw V. , Roehm Bethany , Tang W.H. Wilson , Pandey Ambarish 
Published: December 2024

AimsDiuretic resistance (DR) in heart failure (HF) is associated with worse outcomes. Furoscix®, a self‐administered subcutaneous (sc) furosemide injection administered via on‐body infusor, is approved for HF congestion relief. However, its efficacy in patients with DR post‐HF hospitalization remains unknown.Methods and resultsIn this open‐label pilot randomized controlled trial, 70 participants were randomized within 14 days post‐HF hospitalization to receive a single dose of 80 mg sc furosemide or home oral dose furosemide. Enrolment was stratified by presence of DR (admission BAN‐ADHF score ≥12) with a 2:1 enrolment of those with versus without DR. Key outcomes included diuretic efficiency, the total urine output per mg of diuretic administered, and peak urine sodium within 8 h of dose administration. Treatment effects were calculated as the difference in estimated marginal means across study groups and DR strata using linear mixed‐effect models. Overall, 70 participants were enrolled (57 years, 27% female, 70% Black, 79% with HF with reduced ejection fraction). Participants with DR (n = 46) had worse kidney function, higher N‐terminal pro‐B‐type natriuretic peptide, and higher home diuretic dose. Among participants with DR, sc furosemide versus oral furosemide led to significantly greater diuretic efficiency (34.0 vs. 22.6 ml/mg, p = 0.002) and peak urine sodium (100 vs. 83 mmol/L, p = 0.029), while participants without DR had similar diuretic efficiency (29.8 vs. 30.1 ml/mg, p = 0.94) and peak urine sodium (96 vs. 95 mmol/L, p = 0.93) across both treatments. DR significantly modified the effect of sc versus oral furosemide on diuretic efficiency (pinteraction: treatment × diuretic resistance = 0.022).ConclusionSingle‐dose sc furosemide was associated with greater diuretic efficiency and peak urine sodium than oral furosemide in participants with DR discharged following recent HF hospitalization.
Amorphous Metal Metaphosphate for Oxygen Reduction
Authors: Zhou Min , Guo Jinghui , Lu Ruihu , Li Jiantao , Lee Sungsik , Han Chunhua , Liao Xiaobin , Luo Ping , Zhao Yan , Wang Zhaoyang 
Published: December 2024

ABSTRACTEfficient and cost‐effective catalysts for oxygen reduction reaction (ORR) are crucial for the commercialization of metal‐air batteries. In this study, we utilized theoretical calculations to guide the material synthesis strategy for preparing catalysts. Using density functional theory (DFT) calculations, we systematically explored the ORR performance of metal metaphosphates (A‐M(PO3)2, B‐M(PO3)2, M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) with both amorphous and crystalline structures. Amorphous A‐Mn(PO3)2 showed optimal adsorption energy and the lowest ORR overpotential of 0.32 eV. Phytic acid was employed as a phosphorus source, and the chelating structure of phytic acid molecules and metal ions was broken through the “metal ion pre‐adsorption and spatial confinement strategy” of carbon materials with electron‐rich centers. Following high‐temperature calcination, we successfully prepared a series of amorphous metal metaphosphate composite catalysts for the first time. In 0.1 M KOH electrolyte, both amorphous Mn(PO3)2‐C/C3N4/CQDs (carbon quantum dots) and Mn(PO3)2‐C/C3N4/CNTs (carbon nanotubes) exhibited excellent ORR catalytic activity, with half‐wave potentials of 0.85 V and 0.80 V, respectively. A linear correlation between theoretical overpotentials and experimental half‐wave potentials was discovered through comparison. This work could open a new avenue to the discovery of highly efficient non‐precious metal‐based catalysts with amorphous structures.
Serotype‐Specific Dengue Virus IgG Assay Using EDIII‐Based Recombinant Proteins and Its Application in an Endemic Population in Northeast Brazil
Authors: Pereira Samuel Santos , Machado Rafael Rahal Guaragna , Farias Jéssica Pires , Adreata‐Santos Robert , Rodrigues‐Jesus Mônica Josiane , Fogaça Mayanna Moreira Costa , Souza Milena Silva , Martins Eduardo Gimenes , Romano Camila Malta , Durigon Edison Luiz , Amorim Jaime Henrique , Ferreira Luís Carlos de Souza 
Published: December 2024

ABSTRACTDengue is the most prevalent arboviral disease globally, with Brazil currently experiencing a significant rise in cases. Dengue virus (DENV) typically co‐circulates with other clinically and antigenically similar flaviviruses, such as Zika virus (ZIKV). The clinical diagnosis is difficult and accurate serological analysis represents an unmet challenge. Traditionally, serological analysis of DENV infection focuses on the acute phase via detection of NS1 or IgM. Developing IgG DENV‐specific assays has been defiant due to the co‐circulation of four antigenically distinct serotypes and a strong cross‐reactivity with other arboviruses, particularly with ZIKV. The goal of this study was to produce recombinant domain III of the Envelope (EDIII) proteins of each DENV serotype and ZIKV and evaluate the ability to detect specific IgG antibodies. The antigens were tested on the ELISA platform to measure DENV‐specific IgG in mice and patients infected with ZIKV and DENV. The assay differentiated serotype‐specific IgG responses in susceptible mice (AG129) experimentally infected with DENV or ZIKV. In addition, the test demonstrated a robust performance achieving 87.8% sensitivity and 91.4% specificity when tested against 648 well‐characterized sera collected from humans infected with DENV and/or ZIKV. The test was further applied to serum samples collected from 318 healthy individuals from an endemic region in Northwest/Central Brazil, without a previous diagnosis of DENV, and revealed that 65% of the samples reacted with at least one DENV serotype antigen, including 123 monotypic samples (88 for DENV‐1) and 90 samples reacting with multiple antigens. Collectively, these results indicate that the IgG DENV‐EDIII ELISA is a valuable tool for assessing the serological status of populations in endemic areas, particularly in regions where other flaviviruses, particularly ZIKV, co‐circulate and offer support to establish public health policies against the disease.
Rapid Characterization of the Constituents in Shenhua Tablets by UHPLC‐Q‐Orbitrap‐LTQ‐MS
Authors: Wang Mengmeng , Li Ping , Yin Fengting , Liu Huiqiang , Sun Hui , Zheng Ying , Liu Chang , Wang Yuhang , Chen Xiangmei , Guan Shihan , Wang Xijun 
Published: December 2024

ABSTRACTShenhua Tablet (SHT), a Chinese herbal medicine comprising seven crude drugs, is utilized in the treatment of immunoglobulin A nephropathy (IgAN). However, due to its complex composition, the chemical constituents of SHT in vitro are still incompletely known, which has restricted the comprehensive development and utilization of SHT in clinical practice. In the present study based on ultra‐high performance liquid chromatography‐quadrupole‐orbitrap‐linear ion trap mass spectrometry (UHPLC‐Q‐Orbitrap‐LTQ‐MS) in data dependent acquisition mode, combining the accurate mass and structural information, the profiling and characterization of chemical constituents in SHT were carried out. The automated spectral matching (of experimental MS2 spectra against library spectra of mzCloud) method with a high mass accuracy (within 5 ppm) was used for the rapid identification of compounds. A total of 183 compounds, consisting of 64 flavonoids, 52 terpenoids, 37 organic acids, 6 phenylpropanoids, 5 phenols, and 19 other phytochemicals, were successfully characterized. In addition, the fragmentation pathways and characteristic fragments of some representative compounds were elucidated. The results offered clear insights into its chemical profile, thereby facilitating quality control and advancing pharmacological research.
Digital light processing printed resin based conductive composites with CF@Ag and HGMs@Ag as fillers for metamaterial absorbers
Authors: Li Chenyang , Wang Quandai , He Senao , Zhang Jize , Zhu Bingyang , Yuan Qilong , Li Shujuan 
Published: December 2024

AbstractAn integrated fabrication process based on multi‐material Digital Light Processing (DLP) technique for metamaterial absorbers (MMAs) is proposed. Considering the requirements of the DLP process for the rheological properties and photocuring properties of the slurry, a photopolymer resin slurry was developed using silver‐plated carbon fiber (CF@Ag) and silver‐plated hollow glass microspheres (HGMs@Ag) as conductive fillers. To meet the conductivity requirements of resistive films in MMAs, the study systematically investigated the influence of material parameters and DLP process parameters on the conductivity and precision of the fabricated patterns. Optimized DLP parameters for isotropic photocurable conductive composites with high conductivity and low percolation thresholds were obtained. Additionally, a MMAs was designed to achieve effective absorption in the wavelength range of 7 to 28 GHz. The absorber utilized a resistive film with a thickness of 30 μm and an average surface resistivity of 23 ohm/sq., prepared using a photocurable resin filled with a total mass fraction of 35 wt% CF@Ag and HGMs@Ag in a 2:1 mass ratio. This work shows that it is feasible to fabricate resistive film patterns with prescribed surface resistivity and geometric shapes through DLP printing directly without sintering, providing a promising process for the integrated manufacturing of high‐performance MMAs.Highlights
Developed a conductive slurry using the synergy between CF@Ag and HGMs@Ag.
Proposed the preparation process of resistance controllable resistive film.
The first demonstration of manufacturing resistive film‐type MMAs via DLP.
Preparation and characterization of PA66 composites by waste printed circuit board non‐metallic fractions
Authors: Ning Yue , Li Yugang , Yuan Wenyi , Song Xiaolong , Guan Chuanjin , Huang Qing 
Published: December 2024

AbstractWith the rapid advancement of contemporary technology, there has been a significant increase in electronic waste (e‐waste). The recycling of waste printed circuit board (WPCB) plays a crucial role in this context. The non‐metallic fractions (NMFs) derived from waste PCBs primarily consist of cured resin and fiber. In this study, NMF material from a PCB was ground into a powder and incorporated into a matrix of PA66 to produce PCB‐NMFs‐modified PA66. NMFs treated with inorganic acids are designated as I‐NMFs, while those treated with decanoic acid are referred to as DA‐NMFs. The results indicated that the use of reactive compatibilizers, specifically POE‐g‐MAH (15 parts), significantly enhances the properties of the composites. Among the chemical treatments applied to the NMFs, decanoic acid and n‐heptanoic acid were found to most effectively improve the impact strength of PA66 composites. In this study, decanoic acid was selected as the organic reagent for the treatment of NMFs, with an application amount of 6% relative to the mass of the NMFs. Notably, when DA‐NPCB was filled with 20% and the particle size was reduced to below 100 mesh, its impact strength reached 92.73 kJ/m2, representing an increase of 103.36%. Overall, utilizing PCB‐NMFs as a modifier for PA66 presents a promising and sustainable approach that not only reduces the processing costs associated with electronics but also enhances the performance of the plastic.Highlights
PP‐g‐MAH can increase the bending and tensile stresses of composites.
POE‐g‐MAH improves toughness and impact strength of composites.
Twice as much increase in impact strength of decanoic acid‐treated composites.
Realization of circuit board non‐metallic fractions resource utilization.
Modifying and enhancing the properties of PA66 composites.
Incorporation of Bimetallic Nanoparticles in Zeolitic Imidazolate Framework‐67 (ZIF‐67) for Use as a Catalyst for Ethanol Oxidation
Authors: Bhavani Kalli Sai , Anusha Tummala , Shareef Shaik Nagul , Babu Mattupalli Bujji 
Published: December 2024

AbstractRecently, direct ethanol fuel cells (DEFCs) have been attaining a crucial role in energy resources and transportable devices. Many of the researchers in DEFCs has begin to engage considerable focus due to their high electrocatalytic activity, enormous stability, portability, and inexpensive. In this study, we present an anchoring of bimetallic Pd‐Cu nanoparticles supported ZIF‐67 catalyst (Pd‐Cu@ZIF‐67) for high‐performance electro‐oxidation of ethanol for direct alcohol fuel cells (DAFCs) applications. Structural, morphological, and elemental composition of the proposed catalyst were examined by using UV–vis spectroscopy, XRD, FE‐SEM, and EDX. Further, the electrochemical properties of Pd‐Cu@ZIF‐67 catalyst for ethanol oxidation in basic media were explored by using various electrochemical techniques. According to the results, the suggested catalyst showed maximum ECSA (128.7 m2g−1), higher current density (894.06 mA cm−2), durability (750s), and improved long‐term stability (230 cycles) than the other controlled catalysts towards ethanol oxidation reaction. This enhanced of the Pd‐Cu@ZIF‐67 catalyst is to the synergistic effects of Pd‐Cu nanoparticles and outstanding support material (ZIF‐67). These findings highly suggest the Pd‐Cu@ZIF‐67 catalyst as an anodic potential material in fuel cell applications.