Physics Access最新文献

{"title":"Exploring the Physical Properties of Tungsten Diselenide (WSe2): A First Principle Approach","authors":"Mohammed Adamu, Shuaibu Alhassan, Sadiq G Abdu, Muhammed M Aliyu","doi":"10.47514/phyaccess.2023.3.2.005","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.2.005","url":null,"abstract":"The physical properties of crystalline compounds are highly essential for predicting their applications in various nanodevices. Density functional theory is very useful in that regard. Herein, some physical properties such as structural stability, and electronic, optical and mechanical properties of two-phase bulk WSe2 have been comparatively investigated by first principle calculations. Band structure calculations elucidate that the materials are indirect band gap semiconductors having band gap energy in the range 1-1.5 eV. It was observed that the hexagonal crystal has higher absorption coefficients compared to the trigonal phase. Analysis of elastic constants of the materials carried out using the Born criteria method indicates that all systems are mechanically stable at room temperature. Our findings are in close agreement with the previous experimental and theoretical results, this further suggests that the materials are promising in optoelectronics applications.","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136048991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dielectric Application of Agro-waste Reinforced Polymer Composites: A Review","authors":"Ishaya Iliyasu, Hussaini Yahaya, Mbaka Stephen","doi":"10.47514/phyaccess.2023.3.1.010","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.1.010","url":null,"abstract":"Proper disposal of agricultural waste and polymers after use has long been one of the toughest environmental problems. Since it solves the majority of environmental issues, this has resulted in the development of commercial materials made from biodegradable and renewable sources, a focus of research around the globe. To make composites that are recyclable and degradable, natural fibres have been developed as reinforcing materials. Composite technology is a successful method to enhance the performance of insulating materials used in power system applications as part of the endeavour to optimize materials for industrial applications. The trend in the development of dielectric materials from agricultural waste (agro-waste) reinforced polymeric composites for use in electrical and electronic power systems is the main focus of this study. This article's objective is to provide a brief overview of the many kinds, best practices, and most often used biodegradable polymer matrix reinforcements in eco-composites for dielectric applications. Dielectric constants, dielectric loss factor, volume resistivity, and other properties of composites made with agro-waste as filler, at various frequencies and filler contents, with and without chemical modifications, have been discussed, as well as their prevails and prospects for the future.","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"273 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136053200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First-principles Study on the Structural, Electronic, and Elastic Properties of Transition Metal Dichalcogenides","authors":"Shehu A Yamusa, Amiruddin Shaari, Ibrahim Isah, Basima Farzan, Magaji Ismail, Summanuwa T Ahams, Yahaya S Itas","doi":"10.47514/phyaccess.2023.3.1.007","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.1.007","url":null,"abstract":"In this paper, the structural, electronic, and elastic properties of molybdenum disulfide (MoS2) in hexagonal and trigonal phases were investigated using first-principles calculations based on density functional theory (DFT) as implemented in the Quantum ESPRESSO package. Our findings from the structural and electronic properties of MoS2 show that bulk hexagonal and trigonal MoS2 phases have a calculated bandgap of 1.37 and 1.56 eV respectively, which is in good agreement with available theoretical and experimental results. The elastic properties show that both space groups of MoS2 are brittle at zero pressure and they also agree with Born's mechanical stability condition. The overall results place our new optimized MoS2 as a potential candidate for optoelectronic application.","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135783865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Leachate Plume and Groundwater Pollution using Geophysical and Physio-chemical Methods in an Open Dumpsite at Idugosa, Federal Capital Territory (FCT), Abuja, Nigeria","authors":"Rita C Agu, Abu Mallam","doi":"10.47514/phyaccess.2023.3.2.004","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.2.004","url":null,"abstract":"A geophysical study has been carried out using the electrical resistivity method, Very LowFrequency Electromagnetic (VLF-EM) and physiochemical analysis to investigate the effects of groundwater contamination in the vicinity of an open dumpsite at Idugosa. A Vertical Electrical sounding was carried out at 100 m away from the dumpsite and the results revealed an H-type curve with 3- layers, with a low resistivity value of 90.0 Ωm, thickness of 9.8 m and depth of 11.3 m at the weathered basement. The control VES revealed 5 –layers of HK-type curve. The resistivity of the weathered and fractured basement ranged from 241.8 Ωm to 2908.4 Ωm with a thickness range of 3.5 m to 13.6 m and a depth range of 5.6 m to 19.1 m. Results of the horizontal profiling using Wenner profiling revealed a low resistivity value of 1.6 Ωm to 3.8 Ωm at a depth of 15 m to 30 m, concentrated at stations 20 to 100. The bottom of the western part showed that the leachate plume had infiltrated and contaminated the groundwater in the zone. The VLF-EM with the three profiles revealed high current density values on the KarousHjelt filter plot at distances of 20 m to 38 m for profile 1, 25 m to 50 m and 75 m to 95 m for profile 2, revealing the presence of contaminants which is mainly from decayed organic matter from waste bodies and heavy metals from the dumpsite. Profile 3 which is further away from profile 1 revealed that the contamination is reduced as we move further away from the dumpsite at about 10 m to 20 m, 50 m to 60 m and 90 m respectively. The physio-chemical analysis results showed a pH range of 6.73 – 7.17 which is within the World Health Organization (WHO) standard (6.5 - 8.5). The Electrical Conductivity (EC) value of the Idugosa dumpsite was found to be 804.9 μS/cm, which is above the WHO standard for EC values, which should not exceed 400 μS/cm. This high value can be attributed to the infiltration of the leachate plume from the dumpsite. The EC for Idugosa control which is 188.0 μS/cm is within the WHO limit for groundwater, thus its safe for consumption.","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"2020 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136048992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Fractures on Buildings and Road Construction: A Case Study of Area BZ, Ahmadu Bello University, Zaria, Nigeria","authors":"Inalegwu A Ngbede, Onum S Adikwu, Matthew I Amanyi, Adukwu G Obinna, Cyril G Afuwai","doi":"10.47514/phyaccess.2023.3.1.005","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.1.005","url":null,"abstract":"Structural collapse due to the absence of geophysical information has become a major concern in the construction and building industries today. In this research, we reported the effect of fracture on some selected buildings in Area BZ, Ahmadu Bello University, Zaria. Reflex W software was used to analyze the vertical and horizontal profiles of the subsurface features in two-dimensional (2D) tomography of seismically related regions. The data were collected using MK6 Terraloc seismograph. Seismic refraction method was used to obtain relevant information about the subsurface strata. The velocities of different layers were obtained from the distance-time graph to generate the tomography of the four profiles of 115 m distance each. Results revealed that there are fractures beneath the surface, starting from the depth of 10 m into the basement region as evident in the four (4) profiles with variations in the seismic velocities of 1652 to 2086 m/s and 2521 to 2955 m/s for given strata. The 2D tomography of the study area also revealed that the eastern parts of profiles 1-3 may not be safe for the erection of buildings and other structures without excavation, while profile 4 revealed high levels of structural deformation and it is recommended as a high-risk region that will not support engineering structure. We, however, recommend that further geophysical surveys should be carried out in the area, using Electrical Resistivity Tomography (ERT).","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136052971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of an Automated Admission Ranking Information System (AARISYS)","authors":"Yamusa J Samuel, Rabi Mustapha","doi":"10.47514/phyaccess.2023.3.1.003","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.1.003","url":null,"abstract":"A Decision Support System (DSS) is a useful information systems tool that supports decision-making as it aids institutional admission committees in effective and efficient decision-making. Several types of admission DSS are said to have existed over time. However, for most of the admission DSS as seen from the literature reviewed, soft copies of data are obtained from a source and uploaded onto the system, whereas, the DSS can be made to obtain data directly from the source into itself, thereby speeding up system procedures. The objectives of this study, are to develop an Application Programming Interface (API) and use mathematical methods of weighted grade points for ranking and provision of information for sensitive admission analysis and decision-making. The method of inquiry used in this study was inductive, geared majorly towards consultations of research papers, relevant materials such as educational journals, publications, websites etc., and resource persons through oral interviews. This study adopts a qualitative approach, by studying admission DSS with the aim of improving the existing systems. A Use-case scenario was used as a design model and the system architectural model and program flow were demonstrated as well. Thus, the DSS developed in this study referred to as AARISYS (Automated Admission Ranking System), was implemented using scripting (PHP & JavaScript) and markup languages (HTML & CSS) with MySQL. The web-based system fetches Applicants' data from an external Database (source) via an API, store and assign rank scores. Validation and defect tests were also used and the system results were displayed. Thus, with the aid of API, admission DSS can now obtain data from sources by itself, in contrast to the methods of inputting soft copied data, as used by other DSS.","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"2020 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136053198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First principle study on the Structural and Electronic Properties of Lead-Free Double Halide Perovskite Cs2InSbCl6","authors":"Zainab Ahmad, Magaji Ismail, Alhassan Shuaibu, Bashiru K Sodipo","doi":"10.47514/phyaccess.2023.3.1.008","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.1.008","url":null,"abstract":"The structural and electronic characteristics of Cs2InSbCl6 were investigated using first principle density functional theory (DFT) within local density approximation (LDA) and generalized gradient approximation (GGA) as implemented in the Quantum ESPRESSO package. A supercell with 40 atoms was used in carrying out the calculations, using the optimized lattice parameters of the Cs2InSbCl6 (a = b = c =11.342 Ǻ). The findings revealed that Cs2InSbCl6 is a direct band gap material with gaps of 0.74 eV and 0.99 eV for LDA/PZ and GGA/PBE respectively, in which the GGA/PBE gap shows consistency within the literature range. The calculated densities of states highlight the contributions of the constituent atoms within the valence and the conduction bands.","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136053205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of Heavy Metals in Fish Tissues of Tilapia and Catfish from River Hadejia, Northern Nigeria","authors":"Lawan M Yalwa, Sani G Durumin Iya, Haruna Ahmad","doi":"10.47514/phyaccess.2023.3.2.003","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.2.003","url":null,"abstract":"Kidney failure has become a growing problem at Hadejia Emirates over the last decade. This can be attributed to water pollution, possibly due to heavy metal contamination of River Hadejia that affects organisms living in it, such as fish. This study is aimed to determine the concentration of heavy metals (As, Cd, Cr, Pb) in two fish muscles. The research was conducted on tilapia and catfish where two samples of both fishes were used. The fish tissues were cut and oven-dried at 110 °C, and then a motor and pestle were used to powder the dried fish sample. A wet digestion method was used based on the analytical methods for Atomic Absorption Spectrometry (AAS). The result obtained shows that the concentrations of heavy metals (Cr, Cd, As and Pb) in both fishes were found to be 0.3220 ± 0.0028; 0.1656 ± 0.002 (𝑚𝑔/𝑘𝑔), 0.0319 ± 0.0018; 0.0333 ± 0.0018 (𝑀𝑔/𝑘𝑔), 0.0697 ± 0.0011; 0.1035 ± 0.0015 (𝑚𝑔/𝑘𝑔) and 1.008 ± 0.0035; 0.600 ± 0.002 (𝑚𝑔/𝑘𝑔) respectively. The mean concentration value of the two samples of both tilapia and catfish were found to be above WHO standard limit except for cadmium in tilapia which is below WHO standard limit.","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136049000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the Occurrence of the First Most Intense Geomagnetic Storm (G4) to Hit the Earth in Solar Cycle 25; A Multiple-Step Geomagnetic Storm","authors":"Hammed A Lawal, Mukhtar I Muhammed","doi":"10.47514/phyaccess.2023.3.2.001","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.2.001","url":null,"abstract":"A study of the occurrence of the first intense Geomagnetic storm (G4) to hit the Earth since the start of the Solar Cycle 25 is carried out. This study analyzed the Geomagnetic Storm that occurred between the 28th of October and the 7th of November 2021. The values of the Disturbance storm time (Dst) index of the storm reach -115 nT (G4) which occurred on the 4th of November at 1300UT. The storm is the first intense magnetic storm that occurred in the solar cycle 25. It is also a multiple-step storm with moderate two-step storm occurrence which occurred on the 5th and 6th of November at 1500UT and 0600UT respectively towards the recovery phase after the intense storm. The interplanetary magnetic field (IMF) Bz (nT) during these storm events decreases. Our analysis shows that the rise in solar wind speed, temperature and the enhancement of pressure plays a significant role in the occurrence of the first intense Geomagnetic storm of Solar Cycle 25.","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136049001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural and Electronic Properties of Cu2+ Doped LiMn2O4 Cathode Material for Rechargeable Lithium Ion Battery: A DFT Study","authors":"Owolabi J Adeyemi, Muhammad Y Onimisi, Victor A Odoh, Hassan G Muhammad, Mohammad L Madugu","doi":"10.47514/phyaccess.2023.3.1.002","DOIUrl":"https://doi.org/10.47514/phyaccess.2023.3.1.002","url":null,"abstract":"Spinel LiMn2O4 offers a potentially attractive alternative to the commercialized LiCoO2 because of its low cost, non-toxicity, good rate performance and superior safety, but experiences severe capacity fading as a result of Jahn-Teller cubic phase transition to unstable tetragonal phase especially when operated at elevated temperature (>55oC). Among the various techniques carried out to overcome these setbacks is doping with cations to raise the oxidation state of Mn thereby decreasing the amount of unstable Mn3+. This study focuses on the investigation of the structural and electronic properties of Cu2+ doped LiMn2O4 using ab-initio computational method. The structural properties of both un-doped LiMn2O4 and Cu2+ doped LiMn2O4 were collectively obtained using both generalized gradient approximation (GGA) employing pseudo-potentials, plane wave basis sets and XcryDen. From the electronic properties of undoped LiMn2O4, it was revealed that in LiMn2O4, only Mn3+ ions contribute to conduction, even though Mn3+ ions and Mn4+ ions exist together. Increasing the number of Mn3+ brings it a unique challenge of instability. Due to this instability, avoiding the Mn3+ state of manganese prevents Jahn-teller distortion, resulting in a reduced phase transition. Based on the results from the first-principles calculation of Cu2+ doped LiMn2O4, the Cu valence in doped spinel LiCu0.25Mn0.75O4 is Cu2+ at a fully lithiated state. When half of the Li ions are extracted, the Cu2+ ions oxidized to Cu3+ ions. Since Cu2+ is a di-valent element, the dopant act as electrochemically active centres for valence change, leaving two trivalent ions to only take on +4 oxidation states stably, thus increasing Mn-O bonding strength which ultimately suppressed Jahn-Teller distortions. However, previous studies show that Cu2+ substitution shrinks the lattice because the ionic radius of Cu2+ is smaller than that of the host Mn3+ ions, thereby the reversible capacity of Cu-doped spinel may be reduced as Cu ions can only provide one electron per ion.","PeriodicalId":474567,"journal":{"name":"Physics Access","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136053196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}