Brazilian Journal of Physics最新文献_第9页

Study of Time-Fractional Dust Ion Acoustic Waves Propagation in Collisionless Unmagnetized Dusty Plasmas 无碰撞非磁化含尘等离子体中时间分数尘离子声波传播研究

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-08-08 DOI: 10.1007/s13538-024-01562-3

M. M. Alam, M. S. Alam

{"title":"Study of Time-Fractional Dust Ion Acoustic Waves Propagation in Collisionless Unmagnetized Dusty Plasmas","authors":"M. M. Alam, M. S. Alam","doi":"10.1007/s13538-024-01562-3","DOIUrl":"10.1007/s13538-024-01562-3","url":null,"abstract":"<div>The unmagnetized collisionless dusty plasmas consisting of Maxwell-distributed electrons, inertial ions, and negatively charged dust grains are taken into consideration in order to study the propagation characteristics of time fractional dust ion acoustic waves (DIAWs). The dust grains under consideration are believed to be extremely massive point charges with sizes far smaller than the plasma Debye length and collisional mean free path. The well-known reductive perturbation method is used to derive the Korteweg-de Vries (KdV) equation and then converted the KdV equation into time fractional (TF) KdV (TFKdV) equation using the procedure of El-Wakil et al. (AIP Adv 13:105012 2023). It is found that in the case of the first approximation solution, the amplitude and width of the TFKdV soliton increases with the increasing effect of the time fractional parameter (both in the limit (xi <0) and (xi >0)) and travelling wave velocity (in the range (-50000<xi <25000)). In addition, the amplitude and width of TFKdV soliton are increasing charged dust number and travelling wave velocity in the case of the second approximation solution. The electric field decreases with the time-fractional parameter, while it increases with travelling wave velocity in the case of the second approximation solution.</div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"54 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Generation of Chemically Active Species in Hydrogen Peroxide (H2O2) Discharge Plasma and Their Role in the Eradication of Microorganisms 过氧化氢（H2O2）放电等离子体中化学活性物质的生成及其在消灭微生物中的作用

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-08-05 DOI: 10.1007/s13538-024-01550-7

Ali Akbar Khan, N. A. D. Khattak, Muhammad Khalid, Haifa A. Alyousef, Ali O. Al-Ghamdi, S. A. El-Tantawy

{"title":"Generation of Chemically Active Species in Hydrogen Peroxide (H2O2) Discharge Plasma and Their Role in the Eradication of Microorganisms","authors":"Ali Akbar Khan, N. A. D. Khattak, Muhammad Khalid, Haifa A. Alyousef, Ali O. Al-Ghamdi, S. A. El-Tantawy","doi":"10.1007/s13538-024-01550-7","DOIUrl":"10.1007/s13538-024-01550-7","url":null,"abstract":"<div>Electrical impulse voltage discharges using hydrogen peroxide (H2O2) are of increasing interest for eradicating biological species. Pulsed power is beneficial in addressing the problem of overheating the cathode surface due to successive collisions of energetic plasma species. The present study demonstrates the generation of active species of oxygen (O, O-, and O2), hydrogen (H-α, H-β), and hydroxyl radicals (OH−) in pulsed hydrogen peroxide discharge. The level of active species is directly or indirectly related to the emission intensity by varying the applied current and filling pressure. The discharge is generated between two annular electrodes powered by a 50-Hz pulsed direct current source. The aqueous hydrogen peroxide solution is sucked into the stainless steel reactor by creating a pressure gradient. The experiment is carried out for different discharge currents (0.2–0.5 A) and filling pressures (0.1–0.5 mbar). Optical emission spectroscopy (OES) is performed using McPherson (0.01 nm) and Ocean (0.75 nm) spectrometers to record spectra. Following the optimal discharge conditions, Pseudomonas aeruginosa samples (N × 104 CFU/0.1 ml per sheet) are treated at a filling pressure of 0.5 mbar and a current density of 2.2 mA/cm2 for different treatment times. Inactivation is achieved by counting the viable number of colonies before and after plasma treatment using the serial dilution method. Scanning electron microscopy (SEM) was accomplished for Pseudomonas aeruginosa, which confirms the inactivation of the pathogens.</div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"54 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced Electron-accepting Properties in Polyaniline, Tungsten, and Polymer Nanocomposites 增强聚苯胺、钨和聚合物纳米复合材料的电子接收性能

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-08-03 DOI: 10.1007/s13538-024-01557-0

Jesbin Jebarshia J., Ashokan S., Senthil K.

{"title":"Enhanced Electron-accepting Properties in Polyaniline, Tungsten, and Polymer Nanocomposites","authors":"Jesbin Jebarshia J., Ashokan S., Senthil K.","doi":"10.1007/s13538-024-01557-0","DOIUrl":"10.1007/s13538-024-01557-0","url":null,"abstract":"Polyaniline (PANI), Tungsten oxide (WO3), and PANI:WO3 nanocomposites are prepared by a simple chemical synthesis method and samples are characterized by various characterization. techniques. SEM analysis showed that the WO3 nanoparticles have a strong effect on the morphology of the nanocomposites. The PANI composite exhibited distinctive spherical, granular, and organism-like structures, indicating successful synergistic interactions between PANI and WO3. Elemental analysis confirmed the formation of pure WO3 nanoparticles. The XRD pattern exhibits distinct peaks at 27.6° and 32.5°, which correspond to the (2 0 1) and (0 2 2) planes of WO3, respectively. These peaks indicate an anorthic crystal structure. The observed peak positions are in good agreement with the standard values provided in JCPDS Card nos. 83–0947 and 72–0677, confirming the accurate determination of the crystal structures. Optical emission and UV–Vis spectroscopy revealed changes in electronic transitions and band structures, indicating semiconducting behavior of the PANI nanocomposites. Notably, the direct band gap energy of the PANI composite was found to be 3.84 eV, compared to the band gap energies of pure PANI and WO3 at 4.26 eV. This observed decrease in band gap energy further suggests enhanced semiconducting properties of the composite. FT-IR spectroscopy highlighted common bonding characteristics, affirming the effective integration of PANI and WO3. Electrical studies unveiled enhanced charge carrier mobility, promising advanced electronic applications. The synthesized samples are evaluated for their antibacterial properties against Bacillus subtilis, a Gram-positive bacterium. The results demonstrate significant bactericidal activity, as evidenced by the clear zones of inhibition measuring approximately 11–13 mm in diameter.","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"54 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Semiconductor Nanowire Metamaterial for Tunable Enhanced Absorption 用于可调增强吸收的半导体纳米线超材料

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-08-03 DOI: 10.1007/s13538-024-01570-3

Tatjana Gric

引用次数: 0

The Growth of V5S8 Single Crystals by Chemical Vapour Transport 通过化学气相传输生长 V5S8 单晶体

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-08-01 DOI: 10.1007/s13538-024-01554-3

C. A. Sonego, H. Li, P. Einarsson Nielsen, J. C. Lashley, M. A. Avila, S. E. Rowley

{"title":"The Growth of V5S8 Single Crystals by Chemical Vapour Transport","authors":"C. A. Sonego, H. Li, P. Einarsson Nielsen, J. C. Lashley, M. A. Avila, S. E. Rowley","doi":"10.1007/s13538-024-01554-3","DOIUrl":"10.1007/s13538-024-01554-3","url":null,"abstract":"<div>Single crystals of the d-electron antiferromagnetic metal V5S8 can be prepared by chemical vapour transport with gaseous iodine as a transport agent. We present the outcomes of an endeavour to synthesise high-purity single crystals of V5S8 with reduced crystalline disorder, important to the formation of novel quantum orders. We report results on the residual resistivity ratio of the single crystals as growth parameters are varied including growth temperature, temperature gradient and pre-growth processing of the initial apparatus and reagents. We demonstrate that single crystals of at least a few mm in size can be successfully grown at relatively low temperatures in the range 550–600 °C. The optimisation of this method may imply a better crystallographic organisation, reducing sulphur vacancies and increasing vanadium positional order. The resulting longer electron mean free paths may enhance the probability of finding exotic quantum states of matter at low temperatures. The results presented here may also be of relevance to the development of vanadium sulphide-based energy storage and spintronic devices.\u0000</div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"54 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13538-024-01554-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessment of the Thermoluminescent Properties of Epidote 评估表土的热发光特性

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-08-01 DOI: 10.1007/s13538-024-01565-0

Mendes Farias Letícia, Diniz Chubaci José Fernando, Lucente Campos Letícia, Watanabe Shigueo

{"title":"Assessment of the Thermoluminescent Properties of Epidote","authors":"Mendes Farias Letícia, Diniz Chubaci José Fernando, Lucente Campos Letícia, Watanabe Shigueo","doi":"10.1007/s13538-024-01565-0","DOIUrl":"10.1007/s13538-024-01565-0","url":null,"abstract":"<div>In the literature, little information is found about the crystal structure of epidote; however, there is limited knowledge about the thermoluminescent properties of this mineral. The mineral epidote has the chemical formula Ca({_2})Al({_2})Fe(^{3+})[Si({_2})O({_7})][SiO({_4})]O(OH) and exhibits a dark green coloration. A sample of the mineral epidote, collected in Peru, was investigated. As these are naturally occurring samples, the crystallography of each mineral may vary due to damage caused by natural radiation and the climatic conditions of pressure and temperature to which this mineral has been exposed. Therefore, to determine if the thermoluminescent behavior of different epidote samples would be similar, a mineral collected in Brazil was investigated. The samples were pulverized, and grain sizes ranging from 80 to 180 (mu)m in dimension were utilized. The experiments were conducted employing different thermal treatments and gamma radiation doses aiming identifying the best thermal treatment that allows the obtention of an intense and distinct TL signal. Preliminary TL results demonstrated a clear response of samples irradiated with high doses, exceeding 10 kGy, and thermally treated at 900 °C for 1 h, indicating its potential as a dosimeter for industrial applications. The results of the Thermoluminescence (TL) analysis conducted on the epidote sample from Brazil revealed similarities when compared to the TL analyses of the epidote sample from Peru.</div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"54 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Impact of Varying the Number of Layers Deposited Using the Spin-Coating Technique on the Structural, Optical, and Photocatalytic Properties of Polyvinyl Chloride/Zinc Oxide Nanocomposite Films 利用自旋涂布技术改变沉积层数对聚氯乙烯/氧化锌纳米复合薄膜的结构、光学和光催化性能的影响

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-07-31 DOI: 10.1007/s13538-024-01567-y

Aimane Guedri, Mourad Zaabat, Boubekeur Boudine, Okba Guedri, Abdelkader Hafdallah

{"title":"The Impact of Varying the Number of Layers Deposited Using the Spin-Coating Technique on the Structural, Optical, and Photocatalytic Properties of Polyvinyl Chloride/Zinc Oxide Nanocomposite Films","authors":"Aimane Guedri, Mourad Zaabat, Boubekeur Boudine, Okba Guedri, Abdelkader Hafdallah","doi":"10.1007/s13538-024-01567-y","DOIUrl":"10.1007/s13538-024-01567-y","url":null,"abstract":"<div>Spin coating is a key method for thin film preparation due to its simplicity and cost-effectiveness, relying on the number of layers deposited. This study investigates the impact of sample thickness on polyvinyl chloride (PVC) nanocomposites doped with zinc oxide (ZnO) nanoparticles, focusing on structural, optical properties, and photocatalytic activity. Different numbers of layers (15, 20, 25, and 30) were synthesized via sol–gel spin coating using tetrahydrofuran as a solvent. X-ray diffraction revealed ZnO crystallites in 30-layer films, with a wurtzite structure and 32 nm crystallite size. Raman and infrared spectra confirmed ZnO incorporation. Optical transmittance ranged from 75 to 86%, with band gap energies between 3.45 and 3.94 eV. Photoluminescence spectra indicated ultraviolet and green luminescence attributed to ZnO defects. Photocatalytic efficiency, tested with methylene blue under UV irradiation, showed the 30-layer sample achieving 79% removal efficiency at 60 min, outperforming others.</div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"54 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Regularity for a Fractional Liquid Crystal Model with Anomalous Dissipation and Thermal Effects 具有反常耗散和热效应的分数液晶模型的正则性

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-07-31 DOI: 10.1007/s13538-024-01563-2

José Luis Díaz Palencia

引用次数: 0

Optimizing Spacecraft Re-entry Communication: Plasma Electron Depletion Through Controlled Particulate Injection and Fresnel Coefficients Analysis 优化航天器再入大气层通信：通过受控微粒注入和菲涅尔系数分析实现等离子体电子耗尽

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-07-27 DOI: 10.1007/s13538-024-01568-x

Sima Alilou, Laya Shahrassai, Samad Sobhanian

引用次数: 0

Advanced Terahertz Waveguide Biosensing: Blood Component Detection with a Pentagonal Cladding and Decagonal Core Fiber Design 先进的太赫兹波导生物传感技术：利用五边形包层和十边形芯光纤设计检测血液成分

IF 1.5 4区物理与天体物理

Brazilian Journal of Physics Pub Date : 2024-07-26 DOI: 10.1007/s13538-024-01560-5

A. H. M. Iftekharul Ferdous, Sakhawat Hossain, Perumal Kalpana Devi, Aranganathan Anandan, Benjir Newaz Sathi, Khalid Sifulla Noor, Md.Sabbir Hossain, Kayab Khandakar, Ahmed Nabih Zaki Rashed, Mahmoud M. A. Eid

{"title":"Advanced Terahertz Waveguide Biosensing: Blood Component Detection with a Pentagonal Cladding and Decagonal Core Fiber Design","authors":"A. H. M. Iftekharul Ferdous, Sakhawat Hossain, Perumal Kalpana Devi, Aranganathan Anandan, Benjir Newaz Sathi, Khalid Sifulla Noor, Md.Sabbir Hossain, Kayab Khandakar, Ahmed Nabih Zaki Rashed, Mahmoud M. A. Eid","doi":"10.1007/s13538-024-01560-5","DOIUrl":"10.1007/s13538-024-01560-5","url":null,"abstract":"<div>An optical sensor that recognizes various blood constituent types is demonstrated in this work and is based on a pentagonal-shaped cladding photonic crystal fiber (PCF) model with a decagonal core. The terahertz frequency, which spans from 1.2 to 3 THz, has been examined with the goal of improving relative sensitivity with minimal confinement loss. COMSOL Multiphysics software is used to analyze the sensor’s sensing and guiding properties through an implementation of the finite element method (FEM) technique. Regarding the chosen analytes, comprising red blood cells (RBCs), hemoglobin (HB), white blood cells (WBCs), plasma, and water, notable relative sensitivity responses of 97.26%, 96.52%, 95.62%, 95.08%, and 93.84% are attained at a frequency of 2.2 THz. In order the same analytes and THz frequency in y-polarization mode, small confinement loss (CL) of 2.92 × 10−11 dB/m and effective material loss (EML) of 0.0052 cm−1 are also acquired respectively. All of these typical values for the optical characteristics show the biosensor’s potential because they assure higher sensitivity for detecting blood components while minimizing confinement and material loss.</div>","PeriodicalId":499,"journal":{"name":"Brazilian Journal of Physics","volume":"54 5","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0