Physical Methods Research Articles

An innovative thermal simulation study of microstructure improvement by delay forging during solidification

The solid fraction at the beginning of the forging process is an important factor affecting the performance of the casting-forging integrated forming, which is an innovative and efficient process. The solid fraction depends on the delayed forging time during the casting-forging integrated forming. This paper investigates the effect of delayed forging time on the microstructure of aluminum alloy forged during solidification using an innovative physical simulation method. In this work, a solidification-forging device compatible with the Gleeble system has been developed. Then, experiments were conducted at various delayed forging time. Temperature and force data were collected using the Gleeble system for analysis. Microstructural evolution was investigated using methods including Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Electron Backscattered Diffraction (EBSD), and Three Dimensional Computed Tomography (3D-CT). The results demonstrate that with the extension of the delayed forging time, the grain size of the alloy decreases gradually, and the coarse dendrite structure changes to the rose-shaped grains, and the local misorientation in the grain increases. Moreover, the effect of forging under different forging time on the casting defects of the alloy is studied. When the forging delay is extended to 8 s, the forging promotes the porosity caused by the liquid phase convection. However, with further extension of forging delay, the reduction of the liquid phase and the fracture of dendrites lead to the complexity of liquid phase channels, resulting in the increase of porosity. Additionally, forging near solidification can close shrinkage porosity.

Recycling of activated carbons from spent supercapacitors to refabricate improved supercapacitors

The growing market of commercial electric double-layer capacitors (EDLCs) will lead to a vast accumulation of waste as they arrive out of operation. Recycling the spent electrode activated carbon is a closed-loop solution to provide environmental and economic advantages for EDLC use. However, effectively regenerated methods of high-purity activated carbons are still lacked despite their considerable expense. Herein, a simple steam physical activation method is developed to regenerate high-class activated carbons from spent EDLCs. The process is first demonstrated that can effectively eliminate few electrolytes and complex organics as well as regenerate electrode carbon materials. The activation-recycled carbon materials preserve the physicochemical properties of fresh activated carbons and enhance their mesopore ratios, which contributes to improved EDLC performance, obviously surpassing recycled carbon materials by calcination method, including superior specific capacitance of 103.3 F g−1 at 0.5 A g−1, rate performance and cycling stability, equal to fresh activated carbons. Moreover, the assembled activation-recycled carbon material EDLC delivers low self-discharge rate (89 % of initial voltage after 72 h), wide temperature range (−40 to 85 °C), excellent cycling stability (92.2 % capacitance retention after 10,000 cycles) even at elevated voltages (3.0 V) and temperature (65 °C) test. The present work provides an effective and economic method of recycling high-grade activated carbons for sustainable EDLCs.

Isolation, Antibacterial Activity and Molecular Identification of Avocado Rhizosphere Actinobacteria as Potential Biocontrol Agents of Xanthomonas sp.

Actinobacteria, especially the genus Streptomyces, have been shown to be potential biocontrol agents for phytopathogenic bacteria. Bacteria spot disease caused by Xanthomonas spp. may severely affect chili pepper (Capsicum annuum) crops with a subsequent decrease in productivity. Therefore, the objective of the study was to isolate rhizospheric actinobacteria from soil samples treated by physical methods and evaluate the inhibitory activity of the isolates over Xanthomonas. Initially, soil samples collected from avocado tree orchards were treated by dry heat air and microwave irradiation; thereafter, isolation was implemented. Then, antibacterial activity (AA) of isolates was evaluated by the double-layer agar method. Furthermore, the positive/negative effect on AA for selected isolates was evaluated on three culture media (potato-dextrose agar, PDA; yeast malt extract agar, YME; and oat agar, OA). Isolates were identified by 16S rRNA sequence analysis. A total of 198 isolates were obtained; 76 (series BVEZ) correspond to samples treated by dry heat and 122 strains (series BVEZMW) were isolated from samples irradiated with microwaves. A total of 19 dry heat and 25 microwave-irradiated isolates showed AA with inhibition zones (IZ, diameter in mm) ranging from 12.7 to 82.3 mm and from 11.4 to 55.4 mm, respectively. An increment for the AA was registered for isolates cultured on PDA and YME, with an IZ from 21.1 to 80.2 mm and 14.1 to 69.6 mm, respectively. A lower AA was detected when isolates were cultured on OA media (15.0 to 38.1 mm). Based on the 16S rRNA gene sequencing analysis, the actinobacteria belong to the Streptomyces (6) and Amycolatopsis (2) genera. Therefore, the study showed that microwave irradiation is a suitable method to increase the isolation of soil bacteria with AA against Xanthomonas sp. In addition, Streptomyces sp. BVEZ 50 was the isolate with the highest IZ (80.2 mm).

Evaluation of the impact of shockwave therapy on the functioning of a patient with a lower calcaneal spur

Introduction. A common cause of heel pain is the presence of a calcaneal spur. This condition may disrupt the posterior superficial fascia chain and can also lead to problems in distant areas of the body. Among the physical methods used, shockwave therapy is often applied. The aim of the study was to assess the effectiveness of shockwave therapy and its effect on the tension of the gastrocnemius muscle, which is part of the posterior fascia chain. Materials and Methods. A 52-year-old female patient diagnosed with a left lower calcaneal spur underwent a series of six radial shockwave therapy sessions, performed twice a week. The method for assessing the therapy’s effectiveness involved measuring pain on the Visual Analogue Scale (VAS) and changes in tissue temperature before, immediately after, and five minutes post-therapy. Electromyographic (EMG) examination was used to assess the tension of the gastrocnemius muscle. Results. An average decrease in temperature was observed immediately after the treatment (from 25.3°C to 24.45°C). After five minutes, the temperature increased to 27.05°C compared to the initial measurement. The resting tension of the gastrocnemius muscle, as measured by EMG, decreased as follows: channel 1: from 0.6 µV to 0.4 µV, channel 2: from 4.3 µV to 3.2 µV. Pain decreased from a level of 7 to 2 on the VAS scale. Conclusions. Shockwave therapy is an effective solution for alleviating pain in the case of a calcaneal spur. The reduction of resting tension in the gastrocnemius muscle leads to a decrease in elevated tension within the posterior myofascial chain, which may help reduce the risk of secondary pathologies in distant areas along the chain.

Grey-Box Method for Urban Building Energy Modelling: Advancements and Potentials

Urban building energy modelling (UBEM) has consistently been a pivotal tool to evaluate and control a building stock’s energy consumption. There are two main approaches to build up UBEM: top-down and bottom-up. The latter is the most commonly used in engineering. The bottom-up approach includes three methods: the physical-based method, the data-driven method, and the grey-box method. The first two methods have previously received ample attention and research. The grey-box method is a modelling method that has emerged in recent years that combines the traditional physical method with the data-driven method while it aims to avoid their problems and merge their advantages. Nowadays, there are several approaches for modelling the grey-box model. However, the majority of existing reviews on grey-box methods concentrate on a specific technical approach and thus lack a comprehensive overview of modelling method perspectives. Accordingly, by conducting a comprehensive review of the literature on grey-box research in recent years, this paper classifies grey-box models into three categories from the perspective of modelling methods and provides a detailed summary of each, concluding with a synthesis of potential research opportunities in this area. The aim of this paper is to provide a foundational understanding of grey-box modelling methods for similar research, thereby removing potential barriers in the field of research methods.

Physical Training Methods to Improve the Physical Condition Components of Elite Taekwondo Athletes in The Kyorugi Category: A Systematic Review

Objectives. The study aimed to provide a systematic review of physical training methods to improve the physical condition components of elite taekwondo athletes in the kyorugi category. Materials and methods. An extensive literature assessment of earlier research was carried out. The objective was to examine articles published between 2020 and 2024 that describe strategies for improving the physical condition component of taekwondo athletes. The electronic search was conducted using Google Scholar, PubMed, Web of Science, and Scopus. The articles that addressed methods for enhancing physical condition through exercise were compiled. Results. Sixty publications used training approaches to enhance the physical condition component of elite taekwondo athletes in the kyorugi category. Based on the physical state that is assessed and improved, items are categorized. Among the physical training methods that can be applied in the Taekwondo category of kyorugi are plyometric training, circuit training methods, speed, agility, and quickness (SAQ) training; strength training, endurance training, flexibility training, reaction training, power training, coordination training, balance training, resistance training, and functional training. Conclusions. After thorough analysis, several training techniques have been shown to be effective in enhancing the physical attributes of elite taekwondo athletes in the kyorugi category. These attributes include flexibility, response, strength, power, coordination, agility, speed, balance, and VO₂max.

Silver nanoparticles in medicine and technology: Synthesis, functionality and future prospects

Nanomaterials, particularly nanoparticles (NPs), have emerged as forefront materials of the 21st century due to their unique properties and potential applications. Silver nanoparticles (AgNPs) are among the most attractive inorganic nanomaterials, widely used due to their significant antibacterial properties, broad-spectrum activity, and potential applications across various fields, including health, food storage, textiles, and environmental solutions. AgNPs exhibit a large surface-area-to-volume ratio, enabling enhanced interaction with bacterial cells, making them effective in medical and industrial applications. Despite concerns over their toxicity, AgNP-based products have been approved by multiple regulatory bodies. Nanoparticle synthesis methods are generally divided into physical, chemical, and biological approaches. Although physical and chemical methods are efficient, they involve toxic chemicals and energy-intensive processes. Biosynthesis, particularly plant-based, offers an eco-friendly alternative, reducing the environmental and health risks associated with chemical agents. The review also explores the therapeutic potential of AgNPs in drug delivery systems, especially in topical formulations like nanoemulsions, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs). These nanocarriers enhance drug stability, skin penetration, and controlled release, making them ideal for dermal and transdermal delivery. Moreover, the use of AgNPs in dentistry is highlighted for their bactericidal properties, which help prevent infections and implant failure, with the potential for enhancing therapeutic outcomes without common drawbacks like tooth staining. Overall, AgNPs exhibit promising applications in biomedical, pharmaceutical, and dental fields, and their novel functionalities continue to advance the development of nanotechnology-driven solutions.

Altering the Solid Electrolyte Interface Through Surface-Modification of Lithium Metal Anode for High-Voltage Lithium Battery

Abstract The physical structure and chemical composition of the solid electrolyte interphase (SEI) affect the performance of the lithium metal anode. The tuning of the chemical composition and structure of the SEI through the surface modification of the lithium metal anode has been conducted. A series of dicarboxylic acids, oxalic acid, malonic acid, succinic acid, glutaric acid, and adipic acid have been utilized to modify the surface of the lithium anode. Physical characterization methods have been employed to study the surface morphology and chemical composition of the SEI. Symmetrical (Li/Li) and asymmetrical (NMC622/Li) cells with pristine lithium and surface modified lithium electrodes have been assembled and tested. NMC622/Li cell with surface modified lithium shows improved performance compared to that of pristine lithium. Malonic acid-treated lithium outperforms all the electrodes by retaining 141 mAh/g specific capacity even after 100 cycles of charge-discharge. XPS depth profiling analysis reveals that the SEI on the MA-Li contains evenly distributed organic and inorganic components which are responsible for the performance of MA-Li.

Composites based on cellulose and metal-organic frameworks for dye removal from wastewater

Industrial effluents from enterprises using dyes are among the main production wastes polluting the environment and surface waters. In order to solve this problem, much attention has recently been paid to innovative processes for their removal. The review considers research works over the past 10 years on various biological, chemical and physical methods for dye removal and assesses their effectiveness. The possibility of using cellulose and cellulose-based materials for dye removal from aqueous solutions is shown. The main attention is paid to composites based on cellulose and metal-organic frameworks (Cell-MOF). The main approaches to the creation of Cell-MOF materials and the possibility of regulating their properties are considered. Examples of using Cell-MOF materials for removing dyes from aqueous solutions by adsorption and catalytic methods are given. Prospects and problems of their practical use are discussed.

Discovery of novel NLRP3 inhibitors based on machine learning and physical methods

Discovery of novel NLRP3 inhibitors based on machine learning and physical methods

Correction of methods for calculating the single-phase short circuit current in a rural 0.4 kv electric grid

The relevance of the study lies in the consideration and correction of the results of calculations of the single-phase short circuit current in a rural 0.4 kV electric network obtained using existing physical, computer and mathematical methods that give different results. Purpose. Development of correction coefficients for different methods of calculating the single-phase short circuit current in a rural 0.4 kV electrical network. Materials and research methods. During the calculations of the single-phase short circuit current in the 0.4 kV rural electric grid, using different methods, general initial conditions were set: power was supplied from a TM-250 transformer and using A-35 wire. Results. It was revealed that the error between the results obtained using different methods reaches 35.9%. In the work, correction coefficients with values from 0.93 to 1.47 relative units were proposed in order to increase the reliability of calculations. These coefficients made it possible to increase the reliability of the considered methods for determining the current of a single-phase short circuit in a rural 0.4 kV electrical network by 2.9-6.1 times compared with the initial values.

Prevalence and social determinants of anxiety and depression among adults in Ghana systematic review

Abstract Background Anxiety and depression are major public health concerns, yet their prevalence and social determinants contributing to mental health disparities remain underexplored. This review, to our knowledge, is the first of its kind, aiming to examine the prevalence of anxiety and depression symptoms and disorders among adults in Ghana, along with social determinants associated with their occurrence. Methods A search of nine electronic databases and seven grey literature sources was conducted up to September 25, 2023. Two reviewers independently screened and appraised the studies. Forty-six studies were included. Prevalence estimates were pooled using a random-effects model. Subgroup analysis and meta-regression explored potential moderators. A narrative synthesis explored social determinants associated with anxiety and depression. Results Preliminary results showed a high prevalence of anxiety (43.7%, 95% CI: 35.6-54.4%) and depression (37.8%, 95% CI; 32.5% to 46%), with regional variations. There were significant differences in the prevalence of anxiety and depression across chronic physical conditions and method of condition assessment. Meta-regression showed significant association between average age and anxiety prevalence. Social determinants associated with anxiety included being female, non-Christian, low income, self-employed, limited social support, and basic education, while that for depression included being young (< 25yr), low income, government employed, childhood physical and sexual abuse, gender-based violence and urban residence. Protective factors for both were male gender, strong social support and higher education. Conclusions Preliminary results indicate a high prevalence of anxiety and depression linked to social determinants. While methodological limitations exist (eg, study heterogeneity), findings highlight a need for evidence-based interventions targeting social determinants to reduce the burden of anxiety and depression among adults in Ghana. Key messages • Our review suggests addressing the social determinants of mental health, aligned with sustainable developmental goals, may reduce the burden of anxiety and depression. • While Ghana is working towards improving mental health via its revised 12year Mental Health Policy launched in 2021, this review can facilitate planning and resource allocation for mental healthcare.

Disinfection in Archives—A Short Review of the Sustainable Approaches and Green Perspectives of Using Radiation for Mass Disinfection

The conservation of the immense archival heritage of a country like Italy presents scholars with the enormous challenge of finding techniques and procedures that enable rapid and large-scale interventions, especially in cases of biodeterioration. The volume of material to be preserved and often the inadequacy of the storage conditions constitute crucial factors that promote microbial growth on substrates such as paper, leather, and parchment. These materials serve as primary sources of sustenance for fungi and bacteria which can infect the collections, and so it is frequently necessary to adopt chemical mass-disinfection treatments. These treatments are often expensive, polluting, and hazardous to the assets, the operators, and the environment. The use of ionizing radiation can provide an environmentally sustainable alternative to the traditional mass disinfection treatments of library and archive materials, which currently involve chemical agents (such as ethylene oxide) that impact the environment and human health. The use of such chemicals is increasingly subject to stringent restrictions. In this work, we report and discuss the advantages and disadvantages of physical disinfection methods, focusing on the use of radiation for disinfection treatments and their effects.

Evaluation of physical and chemical isolation methods to extract and purify Campylobacter jejuni extracellular polymeric substances

The pathogenic bacterium Campylobacter jejuni is a major food safety concern as it can form biofilms that increase its survival and infective potential. Biofilms consist of microbial cells and extracellular matrix (ECM), which is made of water and extracellular polymeric substances (EPS), which are critical for structural integrity and pathogenicity. The aim of this study was to optimize a protocol for the isolation of C. jejuni ECM. We employed eight physical and chemical isolation methods to extract and purify ECM, followed by different qualitative and quantitative analyses using gel electrophoresis and spectroscopy. This comprehensive approach enabled the evaluation of ECM composition in terms of polysaccharides, proteins, and extracellular DNA. The isolation methods resulted in different yields and purities of the extracted ECM components. Centrifugation in combination with chemical treatments proved to be most effective, isolating higher concentrations of polysaccharides and proteins. Additionally, extraction with ether solution facilitated the recovery of high-molecular-weight extracellular DNA. Overall, we provide a refined methodology for ECM extraction from C. jejuni. As polysaccharides and proteins participate in biofilm stability and microbial communication, and extracellular DNA participates in genetic exchange and virulence, our study contributes towards a better understanding of the persistence of this pathogen in the food industry.

Microbial remediation of heavy metal-polluted water

Heavy metal pollution in water has become a global environmental problem, threatening aquatic ecosystems and human health. Physical and chemical methods can effectively remove heavy metal pollutants, while their applications are limited due to the high costs, complex operation, and susceptibility to secondary pollution. Bioremediation is the most promising method for eliminating toxic pollutants. Microorganisms including bacteria, fungi, and algae can convert toxic heavy metals into less toxic forms, which has become an effective and environmentally friendly solution for the remediation of heavy metal pollution in water environments. This paper expounds the toxicity and mechanism of heavy metal pollution, microbial remediation mechanisms, and primary microbial remediation strategies, providing a reference for the removal or reduction of metal pollutants in water environments as well as the development of related technologies.

Spectroscopic and biological studies of Pd(II) complexes of 5-(p-tolyl)-1,3,4-oxadiazole-2-thiol

Reactions of Na2PdCl4 with two equivalents of 5-(p-tolyl)-1,3,4-oxadiazole-2-thiol (MoxSH), afford complex of the type [Pd(MoxS)2] (1). Further reaction with equivalent mole of diphosphine ligand {Ph2P(CH2)nPPh2} ( where n = 1 dppm, 2 dppe, 3 dppp, 4 dppb, (CH2)n = dppf ) or two equivalents of triphenyl phosphine or triphenyl phosphine sulfide affords mixed-ligand complexes of the type [Pd(MoxS)2(Ph2P(CH2)nPPh2)] (2-6), [Pd(MoxS)2(PPh3)2] (7) and [Pd(MoxS)2(SPPh3)2](8). The prepared complexes were characterized using different physical and spectroscopic methods. The results indicated that the MoxS ligand behave as coordinate in a anion monodentate fashion sulfur atom to give a square planer around the metal ion. Preliminary anti-bacterial activity has been assessed against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis bacteria. The prepared complexes show good activity in compared with standard drug. [Pd(MoxS)2(dppf)] (6) displays good activity (18, 22 and 20 mm) against certain tested microbes Escherichia coli, Staphylococcus aureus and Bacillus subtilis, respectively. KEY WORDS: Complexes, Palladium, Thione, Anti-bacteria, Phosphine Bull. Chem. Soc. Ethiop. 2025, 39(1), 79-90. DOI: https://dx.doi.org/10.4314/bcse.v39i1.6

Endophytic Bacteria Improve Bio- and Phytoremediation of Heavy Metals

Currently, the problem of heavy metal pollution in China is becoming increasingly serious, which poses grave threats to the environment and human health. Owing to the non-biodegradability and toxicity of heavy metals, a more sustainable and ecological approach to remediate heavy metal pollution has always been a focus of attention for environmental researchers. In recent years, many scientists have found that phytoremediation aided by endophytes has high potential to remediate heavy metals owing to its low cost, effectiveness, environmental friendliness, and sustainability compared with physical and chemical methods. Indeed, the mechanism of interaction between endophytes, plants, and heavy metals in the soil is pivotal for plants to tolerate metal toxicity and thrive. In this review, we focus on the mechanism of how endophytic bacteria resist heavy metals, and the direct and indirect mechanisms employed by endophytic bacteria to promote the growth of plants and enhance phytoextraction and phytostabilization. Moreover, we also discuss the application of combinations of endophytic bacteria and plants that have been used to remediate heavy metal pollution. Finally, it is pointed out that although there have been many studies on phytoremediation systems that have been assisted by endophytes, large-scale field trials are important to deliver “real” results to evaluate and improve phytoremediation assisted with microorganisms in polluted natural environments.

Facile and Environmentally Friendly Synthesis of Ga2O3/MFI Catalysts for Propane Dehydrogenation.

A GaOx-based catalyst is recognized as a promising catalyst for dehydrogenation of light alkanes. Conventionally, impregnation and calcination are necessary processes for the loading of GaOx. However, the incomplete impregnation of gallium salt solution would generate wastewater, and the calcination for the dissociation of gallium salt would release harmful gases, such as SOx, NOx, and HCl. Meanwhile, the high temperature results in an excessive energy cost and undesired GaOx particle aggregation. Here, we report a facile and environmentally friendly method for the synthesis of GaOx-based catalysts. The gallium salt solution was replaced directly with liquid gallium (LG). Through a simple physical mixing method at room temperature, uniform GaOx nanoparticles with diameters of around 3.5 nm were loaded onto the surface of silicalite-1 (S-1). With the optimal GaOx/MFI catalyst, the propane conversion and propylene selectivity reached 22.9 and 90.1%, respectively, in the propane dehydrogenation reaction. The work offers a clean and economical strategy utilizing liquid metal (LM) as an impregnation solution for the preparation of GaOx-based catalysts.

A Review on Green Synthesized Metal Nanoparticles Applications

Nanotechnology pertains to the manipulation of materials at exceedingly small scales, specifically between 1 and 100 nanometers. Materials at this scale exhibit significantly different properties compared to the same materials at larger scales. An emerging trend is the utilization of nanoparticles (NPs) to address environmental issues. Metallic nanoparticles are among the several nanoparticles that are extensively utilized in environmentally sustainable endeavors. A sustainable, economical, and enduring approach is to synthesize nanoparticles through a more ecologically friendly procedure instead of a physical or chemical method. Plant components primarily function as reducing and capping agents in eco-friendly synthesis. Diverse metallic nanoparticles of various sizes and shapes have been created utilizing extracts from plant materials, including leaves, bark, fruits, and flowers. The synthesis of Nobel laureate metal nanoparticles is essential to the medical sector. A diverse array of glycosides and phenolic compounds constitutes numerous organic constituents in plants, facilitating the synthesis of metal nanoparticles. The absence of detrimental by-products in metal nanoparticle synthesis is the primary significance of green synthesis. The nanoparticles generated by an eco-friendly approach demonstrate several significant biological activity. A substantial body of literature demonstrates that the synthesized nanoparticles are efficacious against both gram-positive and gram-negative bacteria, including E. coli, Bacillus subtilis, Klebsiella pneumoniae, and Pseudomonas fluorescens. The synthesized nanoparticles not only display antifungal efficacy against several cancer cell lines, including those of breast cancer, but also demonstrate antifungal activity against Trichophyton simii, Trichophyton mentagrophytes, and Trichophyton rubrum. Moreover, they exhibit potent antioxidant properties. The dimensions and morphology of these metal nanoparticles substantially influence their functionalities. Particles characterized by a large surface area and diminutive size provide significant potential for medical applications. This paper aims to provide a comprehensive summary of current advancements in the synthesis of nanoparticles utilizing biological entities and their numerous potential applications.

Annealing Temperature Effect on TeO2 Thin Films for Optical Detection Devices

Physical vapor deposition method was used for the preparation of nanostructured TeO2. Different morphologies of TeO2 are synthesized using a physical evaporation method with Te powder as the source material and quartz SiO2 as the growth substrates. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and ultraviolet-visible (UV–Vis) analyses are used to characterize the structural, morphological, and optical properties of the TeO2 products obtained. By varying the annealing temperature, different morphology of TeO2 structures is investigated. TeO2 nanostructure progress is initiated by the crystallization of particles. Different temperatures have different effects on structures, which are discussed. The films as deposited nature was amorphous; crystallization occurred at a higher annealing temperature (175 oC). With an increase in annealing temperature, the TeO2 films grain size increased. The research also points to the impact of post-deposition thermal annealing temperatures in excess of 100 °C in enhancing TeO2 film characteristics.