期刊文献+
共找到11篇文章
< 1 >
每页显示 20 50 100
Exciton-polaritons in a 2D hybrid organic-inorganic perovskite microcavity with the presence of optical Stark effect
1
作者 Kenneth Coker 郑楚媛 +2 位作者 Joseph Roger Arhin Kwame Opuni-Boachie Obour Agyekum 张伟利 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期551-555,共5页
This study investigates the properties of exciton-polaritons in a two-dimensional(2D)hybrid organic-inorganic perovskite microcavity in the presence of optical Stark effect.Through both steady and dynamic state analys... This study investigates the properties of exciton-polaritons in a two-dimensional(2D)hybrid organic-inorganic perovskite microcavity in the presence of optical Stark effect.Through both steady and dynamic state analyses,strong coupling between excitons of perovskite and cavity photons is revealed,indicating the formation of polaritons in the perovskite microcavity.Besides,it is found that an external optical Stark pulse can induce energy shifts of excitons proportional to the pulse intensity,which modifies the dispersion characteristics of the polaritons. 展开更多
关键词 EXCITON-POLARITONS PEROVSKITE MICROCAVITY optical Stark effect
下载PDF
Assessment of Axial Power Peaking Factors in GHARR-1 LEU Core: A Decadal Simulation Analysis
2
作者 Emmanuel Kwame Ahiave Emmanuel Ampomah-Amoako +1 位作者 Rex Gyeabour Abrefah Mathew Asamoah 《World Journal of Nuclear Science and Technology》 CAS 2024年第1期72-85,共14页
This study aims to thoroughly investigate the axial power peaking factors (PPF) within the low-enriched uranium (LEU) core of the Ghana Research Reactor-1 (GHARR-1). This study uses advanced simulation tools, like the... This study aims to thoroughly investigate the axial power peaking factors (PPF) within the low-enriched uranium (LEU) core of the Ghana Research Reactor-1 (GHARR-1). This study uses advanced simulation tools, like the MCNPX code for analysing neutron behavior and the PARET/ANL code for understanding power variations, to get a clearer picture of the reactor’s performance. The analysis covers the initial six years of GHARR-1’s operation and includes projections for its whole 60-year lifespan. We closely observed the patterns of both the highest and average PPFs at 21 axial nodes, with measurements taken every ten years. The findings of this study reveal important patterns in power distribution within the core, which are essential for improving the safety regulations and fuel management techniques of the reactor. We provide a meticulous approach, extensive data, and an analysis of the findings, highlighting the significance of continuous monitoring and analysis for proactive management of nuclear reactors. The findings of this study not only enhance our comprehension of nuclear reactor safety but also carry significant ramifications for sustainable energy progress in Ghana and the wider global context. Nuclear engineering is essential in tackling global concerns, such as the demand for clean and dependable energy sources. Research on optimising nuclear reactors, particularly in terms of safety and efficiency, is crucial for the ongoing advancement and acceptance of nuclear energy. 展开更多
关键词 GHARR-1 Power Peaking Factor Nuclear Reactor Safety Low Enriched Uranium Core Operational Longevity Thermal Hydraulics
下载PDF
Electrical Installation Safety Assessment of Buildings in Kumasi, Ghana
3
作者 Bismark Mante Francois Sekyere +2 位作者 Prince Asabere Isaac Prempeh Willie K. Ofosu 《Journal of Power and Energy Engineering》 2024年第9期84-101,共18页
This study aims to evaluate the safety status of electrical installations in residential and commercial buildings within the Suame ECG strategic business unit, Ghana, focusing on compliance with international and Ghan... This study aims to evaluate the safety status of electrical installations in residential and commercial buildings within the Suame ECG strategic business unit, Ghana, focusing on compliance with international and Ghanaian wiring standards. The research assesses key factors influencing safety, including the certification of electricians, the quality of cable brands used, proper cable sizing, adherence to wiring color codes, the awareness and use of Residual Current Circuit Breakers (RCCBs), and the protection of earth electrodes. A descriptive research design was utilized, involving extensive field surveys and electrical installation audits. Data were collected using standardized tools and analyzed with SPSS software to evaluate the professional competencies of artisans and their adherence to safety standards. The findings indicate significant safety risks, with 69.7% of electricians lacking proper certification, leading to the widespread use of non-approved cable brands, improper cable sizing, and deviations from wiring color codes. Additionally, deficiencies were found in the awareness and use of RCCBs and the protection of earth electrodes. The study concludes with recommendations to enhance electrical safety, including mandatory certification for electricians, public awareness campaigns, regular inspections, and ongoing training and development programs. These measures are crucial for improving the overall safety and quality of electrical installations in the Suame area, Ghana. 展开更多
关键词 Earthing System Energy Commission Ghana Wiring Code Residual Current Circuit Breaker Safety
下载PDF
Review of Dimension Reduction Methods
4
作者 Salifu Nanga Ahmed Tijani Bawah +5 位作者 Benjamin Ansah Acquaye Mac-Issaka Billa Francis Delali Baeta Nii Afotey Odai Samuel Kwaku Obeng Ampem Darko Nsiah 《Journal of Data Analysis and Information Processing》 2021年第3期189-231,共43页
<strong>Purpose:</strong><span style="font-family:;" "=""><span style="font-family:Verdana;"> This study sought to review the characteristics, strengths, weak... <strong>Purpose:</strong><span style="font-family:;" "=""><span style="font-family:Verdana;"> This study sought to review the characteristics, strengths, weaknesses variants, applications areas and data types applied on the various </span><span><span style="font-family:Verdana;">Dimension Reduction techniques. </span><b><span style="font-family:Verdana;">Methodology: </span></b><span style="font-family:Verdana;">The most commonly used databases employed to search for the papers were ScienceDirect, Scopus, Google Scholar, IEEE Xplore and Mendeley. An integrative review was used for the study where </span></span></span><span style="font-family:Verdana;">341</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> papers were reviewed. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The linear techniques considered were Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), Singular Value Decomposition (SVD), Latent Semantic Analysis (LSA), Locality Preserving Projections (LPP), Independent Component Analysis (ICA) and Project Pursuit (PP). The non-linear techniques which were developed to work with applications that ha</span></span><span style="font-family:Verdana;">ve</span><span style="font-family:Verdana;"> complex non-linear structures considered were Kernel Principal Component Analysis (KPC</span><span style="font-family:Verdana;">A), Multi</span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">dimensional Scaling (MDS), Isomap, Locally Linear Embedding (LLE), Self-Organizing Map (SOM), Latent Vector Quantization (LVQ), t-Stochastic </span><span style="font-family:Verdana;">neighbor embedding (t-SNE) and Uniform Manifold Approximation and Projection (UMAP). DR techniques can further be categorized into supervised, unsupervised and more recently semi-supervised learning methods. The supervised versions are the LDA and LVQ. All the other techniques are unsupervised. Supervised variants of PCA, LPP, KPCA and MDS have </span><span style="font-family:Verdana;">been developed. Supervised and semi-supervised variants of PP and t-SNE have also been developed and a semi supervised version of the LDA has been developed. </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> The various application areas, strengths, weaknesses and variants of the DR techniques were explored. The different data types that have been applied on the various DR techniques were also explored.</span></span> 展开更多
关键词 Dimension Reduction Machine Learning Linear Dimension Reduction Techniques Non-Linear Reduction Techniques
下载PDF
Design Intervention: An Artistic Strategy (A Strategy) to Minimize Text Fading and Metal Commemorative Plaque Theft in Ghana
5
作者 Ansah-Asiedu Junior Mensah Fiifi Ebenezer +3 位作者 Vicku Charles Samuel Nii Adamah Sampah Henrietta Meakoa Barfi-Mensah Anita Akwaa Toffah 《Open Journal of Metal》 CAS 2023年第1期1-17,共17页
The Commemorative Plaque Industry thrives at the hands of the local craftsmen in Ghana. Techniques, methods, tools, and materials used as handed to them by their previous masters have remained the same over the years.... The Commemorative Plaque Industry thrives at the hands of the local craftsmen in Ghana. Techniques, methods, tools, and materials used as handed to them by their previous masters have remained the same over the years. As a result, plaques produced had peculiar problems such as text fading, degrading the actual effect of the plaques. Additionally, metals once widely used for making plaques devoid of text fading in the industry seem to have lost their relevance due to metal plaque theft, rust on metal plaques, and the continuous rise in metal prices. This research uses descriptive, experimental, and case studies of the qualitative research method to examine the problems associated with locally produced commemorative plaques. A total of hundred (100) artisans, including metal scrap dealers, and plaque buyers, were selected for the study. Direct observation and face-to-face interviews were conducted with the local craftsmen, art lecturers and students, scrap dealers, and plaque buyers who were purposively sampled for the study. The study revealed that existing materials like ceramic and aluminium could be integrated innovatively to produce commemorative plaques devoid of text fading;a corrosion-resistant text could be made using anodized or coated metals used in smaller quantities to reduce costs while also making them unattractive for theft and lastly, silicone sealant was found to be a viable option for permanently inscribing text on porcelain bases. The results clarify and underline the necessity to grow the local plaque industry in terms of plaque production as another essential basis to assure high-quality plaques with no text fading that will survive for generations to serve their intended purpose. 展开更多
关键词 Commemorative Plaques STRATEGY Porcelain Silicone Sealant Anodized Metal
下载PDF
Display of Third Wave Feminism in Chungking Express: A Chinese Film Review
6
作者 Ivy Agyekum 《Journal of Literature and Art Studies》 2023年第6期449-456,共8页
Chungking Express is a Hong Kong film directed by Wong Kar-Wai in 1994.The film consists of two unrelated story lines,with vibrant scenes and unforgettable music.Chungking Express can be discussed from different angle... Chungking Express is a Hong Kong film directed by Wong Kar-Wai in 1994.The film consists of two unrelated story lines,with vibrant scenes and unforgettable music.Chungking Express can be discussed from different angles,however,it is the perhaps unintentional and sometimes subdued portrayal of third wave feminism,which is the focal point of this review.This review compares the depiction of female characters in Chungking and other Chinese female led classics.Finally,this review juxtaposes the male and female characters to actual social gender norms. 展开更多
关键词 Chungking Express FEMINISM SOCIETY
下载PDF
Analysis of Extreme Rainfall Events (Drought and Flood) over Tordzie Watershed in the Volta Region of Ghana 被引量:1
7
作者 Mexoese Nyatuame Sampson Agodzo 《Journal of Geoscience and Environment Protection》 2017年第9期275-295,共21页
In regional water resources management and disaster preparedness, the analysis of extreme rainfall events is essential. The need to investigate drought and flood conditions is now heightened within the context of clim... In regional water resources management and disaster preparedness, the analysis of extreme rainfall events is essential. The need to investigate drought and flood conditions is now heightened within the context of climate change and variability. The Standardised Precipitation Index (SPI) was employed to assess the extreme rainfall event on Tordzie watershed using precipitation data from 1984-2014. The SPI on the time scale of 3, 6, 9 and 12 months were determined using “DrinC” software. The drought was characterised into magnitude, duration, intensity, frequency, commencement and termination at the time scales of SPI-3, SPI-6, SPI-9 and SPI-12. Results indicated that the middle reaches (Kpetoe) of the watershed experienced less severe drought condition compared to the lower reaches (Tordzinu). Mann-Kendall (MK) test and Sen’s slope (SS) revealed general increasing drought trend but insignificant at 95% confidence interval. The SS indicated change in magnitude of 0.016 mm/year, 0.012 mm/year, 0.026 mm/year and 0.016 mm/year respectively at the mentioned time scales at 95% confidence interval at the Tordzinu and that of Kpetoe were 0.006 mm/year, 0.009 mm/year, 0.014 mm/year and 0.003 mm/year. These changes could have implication for agriculture and water resources management and engender food insecurity among smallholder farmers. 展开更多
关键词 Extreme RAINFALL Characteristics Standardised Precipitation Index (SPI) TREND ANALYSIS Tordzie WATERSHED Volta REGION Ghana
下载PDF
Comparative Study of Polypropylene Non-Woven Surgical Mask and Locally Manufactured Woven and Knitted Fabrics Facial Masks 被引量:1
8
作者 Edem Kwami Buami Charles Kumah +2 位作者 Divine Vigbedor Rejoice Makafui Tsotorvor Ruru Pan 《Journal of Textile Science and Technology》 2021年第3期131-141,共11页
The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing... The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing population has brought about the manufacturing of locally fabrics masks to augment or substitute standard medical class facemasks. The study aims at analyzing airflow of these locally manufactured fabrics to determine possible means of transmitting the virus as well as establish comfort of the user of these masks. Standard polypropylene non-woven, woven and knitted fabrics were considered for the study. Air permeability test was conducted on these fabrics using Frazier Air permeability tester. Depending on the property significant variation in the textile fabrics, polypropylene non-woven is widely accepted for facial masks. Nevertheless, this study illustrates that woven and knitted fabrics have more open structures, which allow a high rate of air penetration and so may require two or three layers to prevent antimicrobial or antiviral potential. 展开更多
关键词 Polypropylene Non-Woven Fabric Woven Fabric Knitted Fabric Facial Mask Air Permeability
下载PDF
Use of the Appropriate Fabric for Cloth Face Mask: A Necessity in the Fight against COVID-19
9
作者 Richard Selase Gbadegbe Edem Kwami Buami +1 位作者 Charles Kumah Divine Vigbedor 《Journal of Textile Science and Technology》 2021年第4期172-187,共16页
The outbreak of coronavirus disease (COVID-19) has created a global health crisis that has had a deep impact on the way we perceive our world and our everyday lives. The call for the wearing of face masks as one of th... The outbreak of coronavirus disease (COVID-19) has created a global health crisis that has had a deep impact on the way we perceive our world and our everyday lives. The call for the wearing of face masks as one of the ways of curbing the disease has resulted in the proliferation of cloth face masks on our markets. In the desperation to cash in on the season and make money at all costs, some manufacturers use inferior fabrics to produce face masks. Some of these fabrics do not meet the basic performance requirements of cloth face masks. This study was therefore carried out to research into the appropriate fabrics that will be suitable for the production of cloth face masks in terms of comfort, breathability and protection. To do this, 1225 participants were conveniently drawn for the study. The main research instrument employed for the study was the survey approach in which well-structured questionnaires were administered to solicit information from the participants. To determine the reliability and validity of data, the Cronbach’s Alpha test was conducted. Data were analyzed using the Stata statistical software to perform a multinomial logistic regression to estimate Odds Ratios (ORs) with 95% CIs. A multinomial logit model was constructed to determine the nominal variables. A major finding of the study was that people’s choice of fabric for cloth face masks is determined to a larger extent by their professions. The study also revealed that cotton, silk and linen possess good properties for the production of cloth face masks. Based on the findings, the study concludes that cloth face masks made from two-layered fabrics or three-layered fabrics are the best in terms of comfort and full protection of the wearer. It is recommended that the outer layer should be made from cotton and the inner layer made from linen, cotton-polyester blend or silk. 展开更多
关键词 Air Permeability Breathability COVID-19 FABRIC Cloth Face Mask
下载PDF
Exploitation and Excavation of Land for Clay as Raw Material for Potters in Vume in the Volta Region of Ghana
10
作者 Kofi Asante-Kyei Charles Dogbeda Melos Vicku Henrietta Barfi-Mensah Barfi 《Journal of Geoscience and Environment Protection》 2022年第10期83-91,共9页
Clay is a precious natural resource that is used in practically every aspect of life. It has a wide range of applications, including utilitarian and aesthetic items as well as electrical and electronic gadgets. Vume i... Clay is a precious natural resource that is used in practically every aspect of life. It has a wide range of applications, including utilitarian and aesthetic items as well as electrical and electronic gadgets. Vume is rich in clay types, which may be found in vast concentrations. In Vume, the commonest way of clay winning is the open pit method. Most clay winners usually abandoned the sites after their clay winning activities without any effort to reclaim it. As a result, the study was designed to investigate the causes of such clay over exploitation and its consequences in Vume. The study employed qualitative research method with phenomenological approach to investigate the problem. The convenience sampling as non-probabilty sampling method was adopted to select six (6) clay winners from two (2) sampling sites of clay winning, making a total sampling size of twelve (12) for this research. The justification was that these clay winners were available at the clay sites and also engaging in unsystematic clay winning activities during the visits by the researchers. The main instruments used for data collection were interviews and direct observation of sites. The study showed that if this rapid clay depletion was not addressed, it would have a negative impact on the pottery and ceramic centers in Vume. The study recommended among others that, there could be proper mechanism to organize clay winners into Small Scale Enterprises and become official distributors of clay to potters in Vume and other industries as well as institutions within the catchment area so that government could get tax revenue from the clay winning activities to develop Vume and the country at large. 展开更多
关键词 CLAY Clay Winning EXCAVATION Potters and Pottery Making
下载PDF
Design, manufacture and testing of a prototype obstacle-detection device at blind corners: an automated highway system technology
11
作者 Charles Atombo Emmanuel Gbey Apevienyeku Kwami Holali 《Transportation Safety and Environment》 EI 2021年第1期10-20,共11页
Traffic accidents on highways are attributed mostly to the”invisibility”of oncoming traffic and road signs.”Speeding”also causes drivers to reduce the effective radius of the vehicle path in the curve,thus trespas... Traffic accidents on highways are attributed mostly to the”invisibility”of oncoming traffic and road signs.”Speeding”also causes drivers to reduce the effective radius of the vehicle path in the curve,thus trespassing into the lane of the oncoming traffic.The main aim of this paper was to develop a multisensory obstacle-detection device that is affordable,easy to implement and easy to maintain to reduce the risk of road accidents at blind corners.An ultrasonic sensor module with a maximum measuring angle of 15◦was used to ensure that a significant portion of the lane was detected at the blind corner.The sensor covered a minimum effective area of 0.5 m2 of the road for obstacle detection.Yellow light was employed to signify caution while negotiating the blind corner.Two photoresistors(PRs)were used as sensors because of the limited number of pins on the microcontroller(Arduino Uno).However,the device developed for this project achieved obstacle detection at blind corners at relatively low cost and can be accessed by all road users.In real-world applications,the use of piezoelectric accelerometers(vibration sensors)instead of PR sensors would be more desirable in order to detect not only cars but also two-wheelers. 展开更多
关键词 Arduino blind corner MICROCONTROLLER obstacle detection road accidents
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部