Acta Polytechnica最新文献_第10页

Determination of bond model for 7-wire strands in pretensioned concrete beam 预应力混凝土梁中7股绞线粘结模型的确定

IF 0.8

Acta Polytechnica Pub Date : 2021-12-31 DOI: 10.14311/ap.2021.61.0740

Vadzim Parkhats, R. Krzywoń, Jacek Hulimka, J. Kubica

引用次数: 0

Delamination of polyimide in hydrofluoric acid 聚酰亚胺在氢氟酸中的分层

IF 0.8

Acta Polytechnica Pub Date : 2021-12-31 DOI: 10.14311/ap.2021.61.0684

A. K. Al-mashaal, R. Cheung

引用次数: 0

Cavitation wear of Eurofer 97, Cr18Ni10Ti and 42HNM alloys Eurofer 97、Cr18Ni10Ti和42HNM合金的空化磨损

IF 0.8

Acta Polytechnica Pub Date : 2021-12-31 DOI: 10.14311/ap.2021.61.0762

H. Rostova, V. Voyevodin, R. Vasilenko, I. Kolodiy, V. Kovalenko, V. Marinin, V. Zuyok, A. Kuprin

引用次数: 1

Water-air ejector with conical-cylindrical mixing chamber 带锥形圆柱形混合室的水-空气喷射器

IF 0.8

Acta Polytechnica Pub Date : 2021-12-31 DOI: 10.14311/ap.2021.61.0768

A. Sliusenko, V. Ponomarenko, Inna Forostiuk

{"title":"Water-air ejector with conical-cylindrical mixing chamber","authors":"A. Sliusenko, V. Ponomarenko, Inna Forostiuk","doi":"10.14311/ap.2021.61.0768","DOIUrl":"https://doi.org/10.14311/ap.2021.61.0768","url":null,"abstract":"In the paper, the hydrodynamics of the liquid-gas mixture in the mixing chamber of the ejectors at different spatial positions was analyzed and the comparative study of such ejectors was carried out. It was found that a more ordered mode of movement of the mixture in the mixing chamber is created as a result of the coincidence of the velocity vector of liquid drops and the direction of gravity in the vertical position of the ejectors. This leads to increasing the volume entrainment ratio almost twice. The analysis of the liquid-gas mixture flow in the mixing chamber, evaluation calculations and research allowed to develop and to patent a jet apparatus with a conical-cylindrical (combined) mixing chamber. It was also found that for such ejectors, the volume entrainment ratio is 15–55% higher than for a jet apparatus with a cylindrical mixing chamber due to the reduction of the resistance of the passive flow into the mixing chamber and prevention of the formation of reverse-circulating flows. A study has been conducted on liquid-gas ejectors in the range of the main geometric parameter m (ratio of the mixing chamber area to the nozzle area) 9.4–126.5, which allowed to establish its rational values at which the maximum volume entrainment ratio is achieved (m = 25–40).","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41351195","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}

引用次数: 0

Design of Potential Rainwater Harvesting Structures for Environmental Adoption Measures in India 印度采用环保措施的潜在雨水收集结构设计

IF 0.8

Acta Polytechnica Pub Date : 2021-12-01 DOI: 10.1007/s41050-021-00035-9

Pallavi Uppala, S. Dey

引用次数: 2

On reducing CO2 concentration in buildings by using plants 利用植物降低建筑物中二氧化碳浓度的研究

IF 0.8

Acta Polytechnica Pub Date : 2021-10-31 DOI: 10.14311/ap.2021.61.0617

O. Franek, Č. Jarský

{"title":"On reducing CO2 concentration in buildings by using plants","authors":"O. Franek, Č. Jarský","doi":"10.14311/ap.2021.61.0617","DOIUrl":"https://doi.org/10.14311/ap.2021.61.0617","url":null,"abstract":"The article deals with the implementation of plants in the indoor environment of buildings to reduce the concentration of CO2. Based on a specified model representing the internal environment of an office space, it was studied whether the requirement for the total amount of ventilated air could be reduced by using plants, thereby achieving savings of operating costs in the building ventilation sector. The present research describes the effect of plant implementation according to different levels of CO2 concentration of the supply air, specifically with values of 410 ppm corresponding to the year 2020, 550 ppm to the year 2050 and 670 ppm to the year 2100, as well as according to different levels of CO2 concentration in the indoor environment, namely 1000 ppm and 1500 ppm, the illumination of plants in the indoor environment is constant in the model, PPFD equals to 200 μmolm−2 s−1. Based on the computational model, it was found that the implemented plants can positively influence the requirement for the total amount of ventilated air, the most significant effect is in the case of a low indoor environment quality, with the CO2 concentration of 1500 ppm, and a high supply air quality 410 p˙pm. The simulation also showed that compared to 2020, by the year 2100, it will be necessary to increase the ventilation of the indoor environment by 25.1% to ensure the same quality of the indoorenvironment.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48950409","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}

引用次数: 1

Subjective approach to optimal cross-sectional design of biodegradable magnesium alloy stent undergoing heterogeneous corrosion 异质腐蚀下可生物降解镁合金支架截面优化设计的主观方法

IF 0.8

Acta Polytechnica Pub Date : 2021-10-31 DOI: 10.14311/ap.2021.61.0661

N. Zarei, S. Anvar, S. Goenezen

{"title":"Subjective approach to optimal cross-sectional design of biodegradable magnesium alloy stent undergoing heterogeneous corrosion","authors":"N. Zarei, S. Anvar, S. Goenezen","doi":"10.14311/ap.2021.61.0661","DOIUrl":"https://doi.org/10.14311/ap.2021.61.0661","url":null,"abstract":"Existing biodegradable Magnesium Alloy Stents (MAS) have several drawbacks, such as high restenosis, hasty degradation, and bulky cross-section, that limit their widespread application in a current clinical practice. To find the optimum stent with the smallest possible cross-section and adequate scaffolding ability, a 3D finite element model of 25 MAS stents of different cross-sectional dimensions were analysed while localized corrosion was underway. For the stent geometric design, a generic sine-wave ring of biodegradable magnesium alloy (AZ31) was selected. Previous studies have shown that the long-term performance of MAS was characterized by two key features: Stent Recoil Percent (SRP) and Stent Radial Stiffness (SRS). In this research, the variation with time of these two features during the corrosion phase was monitored for the 25 stents. To find the optimum profile design of the stent subjectively (without using optimization codes and with much less computational costs), radial recoil was limited to 27 % (corresponding to about 10 % probability of in-stent diameter stenosis after an almost complete degradation) and the stent with the highest radial stiffness was selected.The comparison of the recoil performance of 25 stents during the heterogeneous corrosion phase showed that four stents would satisfy the recoil criterion and among these four, the one having a width of 0.161 mm and a thickness of 0.110 mm, showed a 24 % – 49 % higher radial stiffness at the end of the corrosion phase. Accordingly, this stent, which also showed a 23.28 % mass loss, was selected as the optimum choice and it has a thinner cross-sectional profile than commercially available MAS, which leads to a greater deliverability and lower rates of restenosis.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45386768","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}

引用次数: 0

Application of additional insulation to ETICS on surfaces with biocorrosion ETICS在生物腐蚀表面的附加绝缘应用

IF 0.8

Acta Polytechnica Pub Date : 2021-10-31 DOI: 10.14311/ap.2021.61.0590

N. Antošová, P. Šťastný, M. Petro, Štefan Krištofič

引用次数: 2

Design development and study of an elastic sectional screw operating tool 一种弹性分段螺杆操作工具的设计开发与研究

IF 0.8

Acta Polytechnica Pub Date : 2021-10-31 DOI: 10.14311/ap.2021.61.0624

R. Hevko, S. Zalutskyi, I. Tkachenko, O. Lyashuk, O. Trokhaniak

引用次数: 3

Process optimization and performance evaluation of a downdraft gasifier for energy generation from wood biomass 木材生物质发电下吸式气化炉工艺优化及性能评价

IF 0.8

Acta Polytechnica Pub Date : 2021-10-31 DOI: 10.14311/ap.2021.61.0601

I. Daniyan, Felix Ale, I. Uchegbu, K. Bello, Momoh Osazele

{"title":"Process optimization and performance evaluation of a downdraft gasifier for energy generation from wood biomass","authors":"I. Daniyan, Felix Ale, I. Uchegbu, K. Bello, Momoh Osazele","doi":"10.14311/ap.2021.61.0601","DOIUrl":"https://doi.org/10.14311/ap.2021.61.0601","url":null,"abstract":"In recent time, due to the increasing demand for energy and the need to address environment-related issues, a great deal of focus has been given to alternative sources of energy, which are green, sustainable and safe. This work considers the process optimization and performance evaluation of a downdraft gasifier, suitable for energy generation using wood biomass. The assessment of the performance of the downdraft gasifier was based on the amount of output energy generated as well as the emission characteristics of the output. The Response Surface Methodology (RSM) was employed for the determination of the optimum range of the process parameters that will yield the optimum conversion of the biomass to energy. The optimum process parameters that produced the highest rate of conversion of biomass to energy (2.55 Nm3/kg) during the physical experiments were: temperature (1000 °C), particle size (6.0 mm) and residence time (35 min). The produced gas indicated an appreciable generation of methane gas (10.04 % vol.), but with a significant amount of CO (19.20 % vol.) and CO2 (22.68 % vol.). From the numerical results obtained, the gas yield was observed to increase from 1.86908 Nm3/kg to 2.40324 Nm3/kg as the temperature increased from 800 °C to 1200 °C. The obtained results indicate the feasibility for the production of combustible gases from the developed system using wood chips. It is envisaged that the findings of this work will assist in the development of an alternative and renewable energy source in an effort to meet the growing energy requirements.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43895628","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}

引用次数: 1