Advances in Science and Technology最新文献

{"title":"Comparison of Organic and Inorganic - Modified Halloysite Nanotube for Improved Drug Delivery of Aspirin","authors":"Kryzel Maire E. Piolo, Cristella Andrea J. Samonte, Carlo S. Emolaga, J. C. Millare","doi":"10.4028/p-h0cjwf","DOIUrl":"https://doi.org/10.4028/p-h0cjwf","url":null,"abstract":"Halloysite nanotubes (HNTs), the naturally formed mineral clays with hollow tubular structures, have found promising applications as nanocarriers for drug delivery systems due to their biocompatibility and nontoxicity. By modifying the lumen of HNT, drug delivery of various types of sensitive and low-dissolution drugs could be enhanced. This study presents a comparison of the properties of modified HNTs containing an organic modifier (Sodium Laureth Sulfate, SLES) and an inorganic modifier (Sodium Thiosulfate, STS) as carriers of a slightly water-soluble drug, aspirin. HNTs modified by STS showed higher negative zeta potential than those modified by SLES, indicating that STS-modified HNTs are relatively more stable. The negative zeta potential of STS-modified HNT however decreased upon aspirin loading while that of SLES-modified HNT increased, implying that aspirin interacts with the modifiers differently. In terms of drug release, both modified HNTs showed an improved aspirin release rate compared with pure HNT. Moreover, the STS-modified HNT showed a higher aspirin release (21.5%) in the first hour but the SLES-modified HNT showed the highest cumulative release of 62.5% after 6 hours. These results therefore show that the developed modified HNTs improve the release of aspirin and demonstrate how the nature of the modifier (organic or inorganic) on the HNT lumen affects the behaviour of the drug release of aspirin. This also gives an avenue for modulating drug release based on certain requirements such as time and quantity of drug released.","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":"115 48","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381280","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":"7th International Conference on Nanomaterials and Biomaterials (ICNB) and 5th Asia Conference on Material and Manufacturing Technology (ACMMT)","authors":"Steven Y. Liang","doi":"10.4028/b-qt7ius","DOIUrl":"https://doi.org/10.4028/b-qt7ius","url":null,"abstract":"","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":" 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140382054","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":"Study on the Influence of Tool Runout on the Stability of Chatter Vibration Based on Image Estimation of Machined Surface Pattern after Side-End Milling","authors":"Toma Taniguchi, T. Hirogaki, E. Aoyama, Nobutoshi Ozaki","doi":"10.4028/p-yu3jpf","DOIUrl":"https://doi.org/10.4028/p-yu3jpf","url":null,"abstract":"This study investigated the effects of tool runout on chatter vibration taking images of a machined surface to assess the vibration strength, number of vibrations, and phase difference depending on the spindle speed and axial depth of the cut. This study obtained significant results regarding the stability pocket represented by the spindle speed. We observed that the stability limit changed depending on tool runout.","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":" 32","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140385034","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":"Passing through the Vicinity of a Singularity on Off-Line Teaching for End-Milling by Industrial Robot","authors":"D. Kato, Takeuchi Ayumu, Sekioka Masataka, T. Hirogaki, E. Aoyama","doi":"10.4028/p-t0jikm","DOIUrl":"https://doi.org/10.4028/p-t0jikm","url":null,"abstract":"This study proposes a method for passing through the singularity and its vicinity, the biggest challenge on off-line teaching for end-milling by industrial robots. When passing through the singularity and its vicinity, some joints rotate rapidly. However, by changing the wrist configuration: NONFLIP and FLIP, when passing through the singularity, the robot motion can be stabilized. This was verified with a six-degree-of-freedom manipulator. This robot was moved in a linear path such that the end-effector passed through the wrist singularity and its vicinity, and the encoder values were measured simultaneously. The results showed that the commanded rotational speed of the wrist joint exceeded the maximum rotational speed of the servomotor when passing through the wrist singularity and its vicinity, resulting in a trajectory tracking error. However, by changing the wrist configuration, the robot could pass through the singularity and its vicinity without decreasing the trajectory tracking accuracy.","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":" 407","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383315","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":"Positive Valve Overlap as an Effective Conversion Energy System Using Biodiesel","authors":"Alpha Chukwumela Ajie, M. Ojapah, O. Diemuodeke","doi":"10.4028/p-p68nva","DOIUrl":"https://doi.org/10.4028/p-p68nva","url":null,"abstract":"Biodiesel, with the potential to reduce emissions, is an attractive source of renewable energy in the transportation sector, which supports blending of diverse sources such as soybean oil, coconut oil, groundnut oil, palm oil and waste cooking oil. This study presents an analysis of using positive valve overlap of 32 degrees on the performance and emission of a diesel engine fired by biodiesel from two sources (waste cooking oil biodiesel and palm oil biodiesel). The waste cooking oil (WC) and palm oil (PO) biodiesel were blended with diesel fuel in varying proportion of B5, B10, B15, B20, B50, B85, B100. A 2-cylinder diesel engine model was created in Ricardo Wave software environment where simulations were conducted to evaluate brake specific fuel consumption, brake thermal efficiency, brake torque, exhaust gas temperature, CO, HC, and NOx emission. Performance results shows that at 1200 rpm, brake specific fuel consumption of 0.28798 kg/kWh for B100 and 0.27895 kg/kWh for PO100, brake thermal efficiency of 32.55% for B100 and 32.66% for PO100, and brake torque of 33.51N.m for B100 and 34.60 N.m for PO100. Emission results shows that CO emission of 15.10 ppm for B100 and 18.03 ppm for PO100, HC of 45.36ppm for B100 and 45.24 ppm for PO100; NOx of 154.03 ppm for B100 and 167.53 ppm for PO100. The implication is that the palm oil derived biodiesel uses less fuel and produces more brake power and brake torque as compared to waste cooking oil biodiesel. Conversely, emission results show that the palm oil derived biodiesel produces more emissions than waste cooking oil biodiesel.","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":"25 99","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140236895","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 and Simulation of the Major Units of Acetone Plant from Isopropyl Alcohol (IPA) Route","authors":"Elias Ojong Ojong, Victor Ita Etim, G. Aquah, R. I. Uzono","doi":"10.4028/p-nmaxr7","DOIUrl":"https://doi.org/10.4028/p-nmaxr7","url":null,"abstract":"A design of 225[metric tons per year] of an acetone plant from isopropanol alcohol (IPA) was developed. The design considers the fundamental principles of mass and energy balance to size the units of the acetone plant, particularly the Gibbs reactor, separator, absorber, and distillation columns. The beauty of plant design is to account for the material and energy conservation principles interactions and specify the dimensions of the main unit operations of the plant. The HYSYS simulation software was used to design the acetone plant, and the properties of the fluid were used to manually size the plant. The four components resulting from the reaction of IPA and water (acting as a catalyst) to obtain acetone and hydrogen are 2-propanol, acetone, hydrogen, and water. The balance of how these components is heated, reacted, cooled, separated, absorbed, and distilled of acetone from a mixture of IPA/water is shown logically with sketches for the material and energy values of the key unit operations of the plant. The mechanical design of the units was performed to determine the thickness of the columns. In addition, a cost-plus-economic analysis of acetone was carried out. The results indicate that, the sizing of the units gave the following results viz: manually, the reactor with sized 5.4 [m3], 1.56[m] and 2.34[m] as the diameter and height respectively, the separator was sized to 1.78[m] diameter and 2.67[m] height with 6.631[m3] volume, the absorber column gave 0.085[m] diameter, 1.1[m] height, and the distillation column design values are 0.202[m] column diameter, 10.8[m] height and the weir length of 0.154[m]. The overall cost, including the cost of utilities for the entire plant, was [$]7.792million; the equivalent annual operating cost was [$]4.408million; and the thicknesses of the reactor, separator, absorber, and dilation columns are respectively 2.42[mm], 11.71[mm], 1.99[mm] and 3.36[mm]. Validation of the manual design was carried out with HYSYS simulation results, which indicated that the design models were reliable and could be adopted for the design because the deviation values on the specifications of the units are small ranges from 0.04 – 0.4. The result of the design showed that acetone production from the IPA route was recommended and that the HYSYS simulation formed part of the entire design of the acetone plant.","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":"85 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140239676","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":"Hydrogen in Africa: Navigating the Continent’s Unique Energy Transition Landscape and Unsustainable Energy Supply Backbone","authors":"Maryam Tijjani Saleh","doi":"10.4028/p-rm7yhe","DOIUrl":"https://doi.org/10.4028/p-rm7yhe","url":null,"abstract":"Africa's energy dynamics are marked by a blend of rapid urbanization, burgeoning populations, and growing industrialization, all against the backdrop of limited and often unreliable conventional energy infrastructure. This complex scenario prompts an exploration of the viability of hydrogen as a transformative energy solution. The continent's diverse renewable resources, from abundant solar and wind potential to hydropower capabilities, provide fertile ground for hydrogen production. However, Africa's energy transition journey is further complicated by the challenge of retrofitting or establishing sustainable energy systems in regions heavily reliant on fossil fuels. The tension between these established energy supply backbones and the imperatives of reducing carbon emissions necessitates innovative solutions. Hydrogen, with its potential for clean energy storage, emissions-free power generation, and industrial applications, offers a promising bridge between the need for modern energy access and environmental stewardship Drawing from case studies, the study delves the technological feasibility of harnessing hydrogen, considering existing energy infrastructure and emerging renewable technologies, the infrastructural challenges and opportunities presented by establishing hydrogen supply chains across diverse African regions. In conclusion, this paper underscores the significance of hydrogen as a pivotal pillar of Africa's sustainable energy future. This study aims to support policymakers, researchers, and industry stakeholders in navigating the path towards a hydrogen-powered Africa.","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":"125 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140237675","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":"The Design and Energy Simulation of CO2 Capture Process (CCP) for a Liquefied Natural Gas (LNG) Plant","authors":"Wilson Dadet, Elias Ojong Ojong, K. Dagde","doi":"10.4028/p-fd9c5r","DOIUrl":"https://doi.org/10.4028/p-fd9c5r","url":null,"abstract":"The design and energy simulation of carbon dioxide captured process through which Liquefied Natural Gas (LNG) plant has been achieved using Monoethanolamine (MEA) as a solvent. An optimization and technical parameter study for which CO2 captured process (CCP) from the flue gas of a natural gas liquefaction plant was formed based on absorption/desorption process with MEA solutions, using ASPEN HYSYS. This optimization was aimed at reducing the energy requirement for solvent regeneration, by investigating the effects of CO2 removal percentage, stripper operating pressure and cooling water flow. Also, the study showed that major energy savings can be realized by optimizing the lean solvent loading the CO2 transmission phase as well as the stripper operating pressure through the compression and pumping process in the CCP. The specifications, equipment thickness, and cost models were developed based on the principles of conservation of mass and energy, and thermodynamic principles. Aspen HYSYS simulation was carried out on the entire CCP using flue gas of composition carbon dioxide (8.7%), water (17.8%), nitrogen (73.3%), oxygen (0.2%), sulphur dioxide (0.0017%), and nitrox (0.0097%) with input process conditions of pressure 101.6kPa, temperature 150°C and flow rate of 500tons per day. During the study, a minimum thermal energy requirement was found at a lean MEA loading of 0.13, using a 40 wt.% MEA solution and a stripper operating pressure of 130 kPa, resulting in a thermal energy requirement of 1.025 GJ/ton CO2. Recoveries were done at 75%, 80%, 85%, 90%, 95% and 99% of the simulation process. Suitable correlation models were developed relating to the energy consumption rate per stripper operating pressure and specific thermal energy consumption per solvent flow rate with percentage recoveries. When compared to the simulation result, minimum errors of 0.05% and 2% respectively were obtained. The relationship between the compressor power and CO2 recovery was linear at a minimum power consumption of 130 kW at 75% recovery while a maximum consumption of 175 kW was obtained at 99% recovery. It was observed that the specific thermal energy consumption per solvent is linearly related to the extent of recoveries, as higher energy was required to recover more CO2. Compression and pumping with supercritical liquefaction taking the CO2 above critical pressure of 100bar through three compression sections, inter-cooled to 40°C with water at ambient conditions. Thus, enhancing the high efficiency of the system. The HYSYS simulation results, the process conditions and the characterized flue gas were used for the manual computations to determine the efficiency of the CO2, the size and specifications of the absorber and the amine regenerator columns. The HYSYS results obtained from the simulation of the entire CCP gave a recovery of 99% of the CO2 removed from its initial content (8.7%). The energy and thermodynamic analysis of the CCP carried out gave result with","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":"30 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140238975","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":"Africa International Conference on Clean Energy and Energy Storage","authors":"Roland Uhunmwangho, S. O. Oyedepo, O. Diemuodeke, Fidelis Abam, Veronica Edeminam, Anthony Akpasoh","doi":"10.4028/b-bor73v","DOIUrl":"https://doi.org/10.4028/b-bor73v","url":null,"abstract":"","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":"9 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140241107","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":"Regulating Green and Low-Carbon Hydrogen in Africa: A Case Study of South Africa","authors":"Jaqueline Pinto, Kennedy Chege","doi":"10.4028/p-pv7uh9","DOIUrl":"https://doi.org/10.4028/p-pv7uh9","url":null,"abstract":"The production of the most abundant chemical element in the atmosphere, hydrogen, particularly green hydrogen (i.e. hydrogen in its cleanest and most sustainable form), is quickly becoming a priority for nations worldwide. This interest is mainly attributed to, among other factors, its potential to serve as a cornerstone of the global energy transition to low-carbon economies. Green hydrogen possesses the potential to decarbonize the so-called “hard-to-abate,” sectors i.e., energy-intensive sectors, such as heavy industries, iron and steel production, and transportation - including aviation and shipping, among other economic sectors.The growing focus on the adoption of green hydrogen as a viable decarbonization pathway must be viewed against the backdrop of global commitments and international imperatives to address the adverse effects of climate change. Such commitments emanate from instruments such as the Paris Agreement of 2015 and obligations towards meeting the United Nation's Sustainable Development Goals (SDGs). Further, the “Just Energy Transition\" journey towards decarbonization must also be contextualized within different jurisdictions, in line with their situations and context-specific goals, geographic locations, and policy frameworks.Much like other nations worldwide, the South African regulatory framework for hydrogen is still emerging, as it is presently dominated by soft law instruments such as roadmaps, strategies and guiding documents, as opposed to binding and enforceable hard law instruments. For example, the South African Hydrogen Society Roadmap of 2022, the Integrated Resource Plan, the Integrated Energy Plan, and the Renewable Energy Policy, among other significant policy documents, highlight the fundamental role that green hydrogen would play in South Africa’s energy transition. Whilst other legal and policy documents may apply to the hydrogen value chain, such as the various safety requirements in the Occupational Health and Safety Act, 1996, there is a lacuna of hydrogen-specific hard law regulation, including, importantly, regulations regarding certification (which will need to be aligned internationally).In light of the above, this paper discusses the potential of green hydrogen in the context of South Africa and explores the current position in the country. It further canvasses emerging developments within the hydrogen space. This analysis aims to identify gaps or lacunas in the law, risks, and challenges for South Africa’s hydrogen economy. The article proceeds to provide recommendations for a policy and regulatory regime for hydrogen in Southern Africa. It draws on examples from countries and regions such as the European Union (EU), which are further along in terms of regulating hydrogen, but contextualizing this discussion within the African, and specifically Southern African context. This budding industry provides an opportunity to learn from past energy mistakes and create an appropriate regulatory and policy fr","PeriodicalId":511802,"journal":{"name":"Advances in Science and Technology","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140241020","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}