Pub Date : 2020-06-30DOI: 10.15587/1729-4061.2020.205347
Y. Kovalenko, V. Tokarchuk, V. Poliuha
The effect of a methyl hydroxyethyl cellulose additive on the technical and physical-mechanical properties of the cement matrix has been investigated. The study involved cellulose ether of low (11,000–16,000 MPa∙s), medium (17,000–23,000 MPa∙s), and high (20,000–30,000 MPa) viscosity. The additives were introduced into cement in the amount of 0.25, 0.5, and 0.75 % by weight. It has been established that the introduction of cellulose ether in cement leads to an increase in the normal density of the slurry and extends the duration of the mortar setting. The normal density of cement slurry increases with the introduction of cellulose ethers of low viscosity (LV) and medium viscosity (MV) by 5.4‒16.8 %; when introducing the ether of high viscosity (HV), by 21.3–41.4 %. This confirms the high water-retaining capacity of methyl hydroxyethyl cellulose, which increases with increasing viscosity of the additives. The setting duration of cement slurry increases, depending on the concentration and viscosity of the additives, by 2‒4 times, compared with an additive-free material. There is also a significant reduction in the strength of the cement matrix in the early periods of hardening (1–7 days) depending on the concentration of the additives, by 2.2–4.2 times. The strength of the samples is least affected by the cellulose ether of low viscosity, largest – by that of high viscosity. The reduction of strength is observed at the age of 28 days, although not very much pronounced. Compared to the additive-free cement, the strength amount to: for the ester of low viscosity at concentrations: 0.25 % by weight – 14.3 %, 0.50 % by weight – 23.9 %, 0.75 % by weight – 40.5 %; for the ether of medium viscosity, respectively, 23.8, 26.2, and 33.3 %; for the ether of high viscosity, 28.6; 45.2, and 61.0 %. The corrosion resistance of the cement matrix with methyl hydroxyethyl cellulose additives is increased at a concentration of up to 0.25 % by weight and then gradually decreases. The above results make it possible to recommend using, in the production of dry construction mixtures, the cellulose ethers of low and medium viscosity, which would ensure the required time to maintain the solution mobility and the sufficient strength of the resulting material
{"title":"The Effect of Methyl Hydroxyethyl Cellulose on the Cement Matrix Properties","authors":"Y. Kovalenko, V. Tokarchuk, V. Poliuha","doi":"10.15587/1729-4061.2020.205347","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.205347","url":null,"abstract":"The effect of a methyl hydroxyethyl cellulose additive on the technical and physical-mechanical properties of the cement matrix has been investigated. The study involved cellulose ether of low (11,000–16,000 MPa∙s), medium (17,000–23,000 MPa∙s), and high (20,000–30,000 MPa) viscosity. The additives were introduced into cement in the amount of 0.25, 0.5, and 0.75 % by weight. It has been established that the introduction of cellulose ether in cement leads to an increase in the normal density of the slurry and extends the duration of the mortar setting. The normal density of cement slurry increases with the introduction of cellulose ethers of low viscosity (LV) and medium viscosity (MV) by 5.4‒16.8 %; when introducing the ether of high viscosity (HV), by 21.3–41.4 %. This confirms the high water-retaining capacity of methyl hydroxyethyl cellulose, which increases with increasing viscosity of the additives. The setting duration of cement slurry increases, depending on the concentration and viscosity of the additives, by 2‒4 times, compared with an additive-free material. There is also a significant reduction in the strength of the cement matrix in the early periods of hardening (1–7 days) depending on the concentration of the additives, by 2.2–4.2 times. The strength of the samples is least affected by the cellulose ether of low viscosity, largest – by that of high viscosity. The reduction of strength is observed at the age of 28 days, although not very much pronounced. Compared to the additive-free cement, the strength amount to: for the ester of low viscosity at concentrations: 0.25 % by weight – 14.3 %, 0.50 % by weight – 23.9 %, 0.75 % by weight – 40.5 %; for the ether of medium viscosity, respectively, 23.8, 26.2, and 33.3 %; for the ether of high viscosity, 28.6; 45.2, and 61.0 %. The corrosion resistance of the cement matrix with methyl hydroxyethyl cellulose additives is increased at a concentration of up to 0.25 % by weight and then gradually decreases. The above results make it possible to recommend using, in the production of dry construction mixtures, the cellulose ethers of low and medium viscosity, which would ensure the required time to maintain the solution mobility and the sufficient strength of the resulting material","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"113 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83582822","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}
Pub Date : 2020-06-30DOI: 10.15587/1729-4061.2020.202501
K. Kasabova, S. Sabadash, V. Mohutova, Vadym Volokh, A. Poliakov, T. Lazarieva, O. Blahyi, Oleg Radchuk, Vladyslav Lavruk
When heating liquid and paste-type products, enterprises in the food industry commonly use scraper heat exchangers, which, given their high heat treatment intensity, make it possible to retain the original properties of the treated raw materials. Most heat exchangers demonstrate an unstable stabilizing effect: the vapor pressure ‒ the temperature that leads to damage to raw materials, under conditions of significant energy- and metal capacity. It is possible to eliminate these drawbacks by using a temperature-stable flexible film resistive electric heater of the radiating type as a heater in an improved scraper heat exchanger. We have proposed applying a hinged blade with a cutting edge (with a reflective heating surface) as a stirring element of the heat exchanger to obtain the uniform distribution of a product layer thickness at the working surface and to additionally heat by the blade's reflective surface. The heat exchanger can be supplemented with a cooling shell with ring channels to pass the refrigerant, which is placed on the outer surface of the non-thermally insulated flexible electric heater. Such a solution provides the possibility of cooling to −15 °C and it simultaneously serves the additional air thermal insulation in the absence of the carrier in it. We have determined the uniformity of heat flow distribution over the heating surface of the model design of the improved unit (60.3...60.5 °C) and at the reflective surface of the hinged blade with a cutting edge (60.0...60.3 °C). The total thickness of a liquid layer has been established depending on the shaft rotation frequency of the proposed hinged blade with a cutting edge: at 50 min –1 – 1–2.65 mm, at 350 min –1 –1.5 mm, compared with a standard hinge blade (a layer thickness is from 5.0 mm to 1.5 mm), in terms of product consumption W=50 l/h. The improved scraper heat exchanger is characterized by a 1.48-time decrease in the specific energy consumption (170.4 kJ/kg), used to heat a product volume unit, compared to the heater with a steam shell – 252.6 kJ/kg. The research result is the confirmed efficiency of using the improved scraper heat exchanger, as well as its proposed structural scheme
{"title":"Improvement of a Scraper Heat Exchanger for Pre-Heating Plant-Based Raw Materials Before Concentration","authors":"K. Kasabova, S. Sabadash, V. Mohutova, Vadym Volokh, A. Poliakov, T. Lazarieva, O. Blahyi, Oleg Radchuk, Vladyslav Lavruk","doi":"10.15587/1729-4061.2020.202501","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.202501","url":null,"abstract":"When heating liquid and paste-type products, enterprises in the food industry commonly use scraper heat exchangers, which, given their high heat treatment intensity, make it possible to retain the original properties of the treated raw materials. Most heat exchangers demonstrate an unstable stabilizing effect: the vapor pressure ‒ the temperature that leads to damage to raw materials, under conditions of significant energy- and metal capacity. It is possible to eliminate these drawbacks by using a temperature-stable flexible film resistive electric heater of the radiating type as a heater in an improved scraper heat exchanger. We have proposed applying a hinged blade with a cutting edge (with a reflective heating surface) as a stirring element of the heat exchanger to obtain the uniform distribution of a product layer thickness at the working surface and to additionally heat by the blade's reflective surface. The heat exchanger can be supplemented with a cooling shell with ring channels to pass the refrigerant, which is placed on the outer surface of the non-thermally insulated flexible electric heater. Such a solution provides the possibility of cooling to −15 °C and it simultaneously serves the additional air thermal insulation in the absence of the carrier in it. We have determined the uniformity of heat flow distribution over the heating surface of the model design of the improved unit (60.3...60.5 °C) and at the reflective surface of the hinged blade with a cutting edge (60.0...60.3 °C). The total thickness of a liquid layer has been established depending on the shaft rotation frequency of the proposed hinged blade with a cutting edge: at 50 min –1 – 1–2.65 mm, at 350 min –1 –1.5 mm, compared with a standard hinge blade (a layer thickness is from 5.0 mm to 1.5 mm), in terms of product consumption W=50 l/h. The improved scraper heat exchanger is characterized by a 1.48-time decrease in the specific energy consumption (170.4 kJ/kg), used to heat a product volume unit, compared to the heater with a steam shell – 252.6 kJ/kg. The research result is the confirmed efficiency of using the improved scraper heat exchanger, as well as its proposed structural scheme","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89051333","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}
Pub Date : 2020-06-30DOI: 10.15587/2706-5448.2020.200897
V. Lyashenko, O. Khomenko, Fedor Topolnij, O. Helevera
The object of research is environmental and resource-saving technologies in underground mining of mineral deposits with the laying of the developed space. One of the most problematic places is the delivery of hardening filling mixtures to the place of their installation and the lack of components for their preparation. This increases the importance of managing the state of ore-bearing massifs and the preservation of the earth’s surface.
The paper presents the main scientific and practical results of the substantiation of technologies and technical means for the disposal of mining and metallurgical production wastes into underground mined spaces (man-made voids) as components of hardening filling mixtures. Methods of theoretical generalizations are described using mathematical statistics, physical and mathematical modeling, with calculations and feasibility studies, laboratory and field experimental studies, industrial tests in operating enterprises. It is established that the use of vibration, mechanical and electroactivation of the components of the hardening filling mixture in mining enterprises leads to an increase in the activity of substandard materials by up to 10–40 % for each device. In particular, the enrichment of substandard inert materials at the vibrating screen GV-1.2/3.2 (Ukraine) increases the activity by 15–20 %. It is proved that the activation of binders (blast furnace granulated slag) in the DU-65 disintegrator (Disintegrator, Estonia) increases the activity of the binder by 20–25 %, with the output of the active class of fractions of 0.074 mm in size – by 55 % versus 40 % in ball mills. Vibration transport unit are recommended, which increase the activity of the solid components of the hardening filling mixture by 10–15 %, and electrodialysis apparatus for activating mixing water increase its activity by 30–40 %. It is shown that the use of vibration gravity transport systems ensures the filling of the filling mixture at a distance exceeding the height of the vertical stand by 15–20 times. A set of technical means is proposed for activating the components of hardening filling mixtures (binder, inert aggregate and electrochemically purified mine mixing water) during the manufacture and transportation of them to the installation site. This complex was introduced at such mining enterprises as:
– State Enterprise «Eastern Mining and Processing Plant» and Balaklava Mining Administration (Ukraine);
– Joint-stock company «Tselinnyi Mining and Chemical Combine» (Republic of Kazakhstan);
– Public Joint-Stock Company «Priargunsky Industrial Mining and Chemical Association» and Closed Joint-Stock Company «Uralzoloto» (Russian Federation) in other developed mining countries.
{"title":"Substantiation of Technologies and Technical Means for Disposal of Mining and Metallurgical Waste in Mines","authors":"V. Lyashenko, O. Khomenko, Fedor Topolnij, O. Helevera","doi":"10.15587/2706-5448.2020.200897","DOIUrl":"https://doi.org/10.15587/2706-5448.2020.200897","url":null,"abstract":"The object of research is environmental and resource-saving technologies in underground mining of mineral deposits with the laying of the developed space. One of the most problematic places is the delivery of hardening filling mixtures to the place of their installation and the lack of components for their preparation. This increases the importance of managing the state of ore-bearing massifs and the preservation of the earth’s surface.<br><br>The paper presents the main scientific and practical results of the substantiation of technologies and technical means for the disposal of mining and metallurgical production wastes into underground mined spaces (man-made voids) as components of hardening filling mixtures. Methods of theoretical generalizations are described using mathematical statistics, physical and mathematical modeling, with calculations and feasibility studies, laboratory and field experimental studies, industrial tests in operating enterprises. It is established that the use of vibration, mechanical and electroactivation of the components of the hardening filling mixture in mining enterprises leads to an increase in the activity of substandard materials by up to 10–40 % for each device. In particular, the enrichment of substandard inert materials at the vibrating screen GV-1.2/3.2 (Ukraine) increases the activity by 15–20 %. It is proved that the activation of binders (blast furnace granulated slag) in the DU-65 disintegrator (Disintegrator, Estonia) increases the activity of the binder by 20–25 %, with the output of the active class of fractions of 0.074 mm in size – by 55 % versus 40 % in ball mills. Vibration transport unit are recommended, which increase the activity of the solid components of the hardening filling mixture by 10–15 %, and electrodialysis apparatus for activating mixing water increase its activity by 30–40 %. It is shown that the use of vibration gravity transport systems ensures the filling of the filling mixture at a distance exceeding the height of the vertical stand by 15–20 times. A set of technical means is proposed for activating the components of hardening filling mixtures (binder, inert aggregate and electrochemically purified mine mixing water) during the manufacture and transportation of them to the installation site. This complex was introduced at such mining enterprises as:<br><br>– State Enterprise «Eastern Mining and Processing Plant» and Balaklava Mining Administration (Ukraine);<br><br>– Joint-stock company «Tselinnyi Mining and Chemical Combine» (Republic of Kazakhstan);<br><br>– Public Joint-Stock Company «Priargunsky Industrial Mining and Chemical Association» and Closed Joint-Stock Company «Uralzoloto» (Russian Federation) in other developed mining countries.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74938098","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}
Reasoned fertilization is a major concern for sustainable agriculture and requires a major increase in the number of fertilizer formulas that cannot be achieved cost-effectively with current production models. We propose therefore a new approach, called reverse blending, based on a delayed differentiation performed nearby end-users, consisting in defining the composition of inputs that do not pre-exist, whose number must be as small as possible and whose blends will meet the exact requirements of a very wide variety of customized fertilizers. This approach is demonstrated through a case study that has identified the optimal composition of 8 inputs, whose blends enable the production of 700 fertilizers that are customized for some Moroccan provinces.
{"title":"Reverse Blending as a Strategy for Purely Customizing Fertilizers While Considerably Reducing the Diversity to Be Produced: A Case Study","authors":"L. Benhamou, P. Féniès, F. Fontane, V. Giard","doi":"10.2139/ssrn.3636066","DOIUrl":"https://doi.org/10.2139/ssrn.3636066","url":null,"abstract":"Reasoned fertilization is a major concern for sustainable agriculture and requires a major increase in the number of fertilizer formulas that cannot be achieved cost-effectively with current production models. We propose therefore a new approach, called reverse blending, based on a delayed differentiation performed nearby end-users, consisting in defining the composition of inputs that do not pre-exist, whose number must be as small as possible and whose blends will meet the exact requirements of a very wide variety of customized fertilizers. This approach is demonstrated through a case study that has identified the optimal composition of 8 inputs, whose blends enable the production of 700 fertilizers that are customized for some Moroccan provinces.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82791595","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}
Pub Date : 2020-06-19DOI: 10.15587/1729-4061.2020.203279
A. Salenko, O. Chencheva, V. Glukhova, V. Shchetynin, Mohamed R. F. Budar, S. Klimenko, E. Lashko
Results of theoretical and experimental studies aimed at establishing features of micro-cutting with abrasive grains characterized by active emission of slime and dust particles were presented. The slime particles are just partially withdrawn from the interaction zone and partially change surfaces of the tool and the workpiece of a carbon composite material, in particular, of carbon-carbon and carbon-polymer groups. The above materials possessing a complex of unique physical and mechanical properties are used in high-tech production though composites remain difficult to process materials. The problems manifest themselves to their utmost in making various apertures, shoulders, cutting of holes, processing edges. The study has shown that the phenomenon of dust and slime emission in abrasive processing of carbon-based non-dense composites and plastics results from sliding fracture and cyclic weakening of the surface non-dense layer which exhibits quasi-brittle properties under the action of fast-moving micro-indenters. Conditionality of the average slime particle sizes by normal stresses in the cutting zone and the magnitude of protrusion of diamond grains above the cutting surface of the tool was revealed. Since it was found that the particles formed during cutting are only partially withdrawn outside the cutting zone and the degree of removal decreases with an increase in the processing time, a conclusion on the cause of change in the state of the tool surface was drawn. The remaining slime and dirt change topography of the surface which results in the cutting zone temperature rise to critical values. It was shown that the use of tools with cyclic advance makes it possible to partially improve the condition of material processing which is relevant for the implementation of the processes of ring diamond drilling, processing with diamond saw blades. It was proved that the intermittent application of areas of the diamond-bearing layer reduces the phenomenon of dirt particle sticking to the surface of the working tool. Thus, the tool stays free of dirt for longer and the machining process is more efficient
{"title":"Effect of Slime and Dust Emission on Micro-Cutting When Processing Carbon-Carbon Composites","authors":"A. Salenko, O. Chencheva, V. Glukhova, V. Shchetynin, Mohamed R. F. Budar, S. Klimenko, E. Lashko","doi":"10.15587/1729-4061.2020.203279","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.203279","url":null,"abstract":"Results of theoretical and experimental studies aimed at establishing features of micro-cutting with abrasive grains characterized by active emission of slime and dust particles were presented. The slime particles are just partially withdrawn from the interaction zone and partially change surfaces of the tool and the workpiece of a carbon composite material, in particular, of carbon-carbon and carbon-polymer groups. The above materials possessing a complex of unique physical and mechanical properties are used in high-tech production though composites remain difficult to process materials. The problems manifest themselves to their utmost in making various apertures, shoulders, cutting of holes, processing edges. The study has shown that the phenomenon of dust and slime emission in abrasive processing of carbon-based non-dense composites and plastics results from sliding fracture and cyclic weakening of the surface non-dense layer which exhibits quasi-brittle properties under the action of fast-moving micro-indenters. Conditionality of the average slime particle sizes by normal stresses in the cutting zone and the magnitude of protrusion of diamond grains above the cutting surface of the tool was revealed. Since it was found that the particles formed during cutting are only partially withdrawn outside the cutting zone and the degree of removal decreases with an increase in the processing time, a conclusion on the cause of change in the state of the tool surface was drawn. The remaining slime and dirt change topography of the surface which results in the cutting zone temperature rise to critical values. It was shown that the use of tools with cyclic advance makes it possible to partially improve the condition of material processing which is relevant for the implementation of the processes of ring diamond drilling, processing with diamond saw blades. It was proved that the intermittent application of areas of the diamond-bearing layer reduces the phenomenon of dirt particle sticking to the surface of the working tool. Thus, the tool stays free of dirt for longer and the machining process is more efficient","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89501114","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}
Pub Date : 2020-06-19DOI: 10.15587/1729-4061.2020.203245
A. Lovska, O. Fomin, Anna Chechet, O. Soloviova
The paper reports the improvement in the bearing structure of a platform wagon that transports military equipment and is involved in artillery fire. A special feature of the platform wagon is the presence of rotary sectors made from a composite material with viscous or elastic-viscous links, which makes it possible to absorb the kinetic energy that is transmitted to the frame when firing from the wagon, as well as enables the loading/unloading of military equipment from its side. We have investigated the dynamic loading of the bearing structure of a platform wagon for military equipment transportation and combat operations. A mathematical model has been constructed, which takes into consideration the movement of the bearing structure of a platform wagon when firing from it. It has been considered that the platform wagon is loaded with two anti-aircraft guns. The mathematical model was solved in the Mathcad programming environment. The study was conducted in a flat coordinate system. We have determined the accelerations that act on the bearing structure of a platform wagon. The maximum acceleration rate, in this case, is about 3.6 m/s 2 at bouncing oscillations and 4.0 m/s 2 at galloping oscillations. In other words, considering the proposed technical solutions, the dynamic loading of the bearing structure of a platform wagon in the vertical plane at firing decreases by almost 30 %. The magnitude of the acceleration is almost independent of the firing angle in this case. The derived acceleration values have been taken into consideration in determining the strength indicators for the bearing structure of a platform wagon. Calculation was carried out by the method of finite elements in the CosmosWorks programming environment. The maximum equivalent stresses in the bearing structure of a platform wagon amounted to about 285 MPa; they are concentrated in the region where the bearing structure rests on the trolley. Consequently, the durability of the bearing structure of a platform wagon is ensured. Modal analysis of the bearing structure of a platform wagon has been conducted. The values of the natural oscillation frequencies are within allowable limits. Our research would contribute to designing innovative structures for platform wagons
本文报道了一种用于运输军事装备和参与火炮射击的平台车的轴承结构的改进。平台车的一个特殊功能是由具有粘性或弹性粘性链接的复合材料制成的旋转部分的存在，这使得从马车发射时吸收传递到框架的动能成为可能，并且能够从其侧面装载/卸载军事装备。对军用装备运输和作战用平台式货车承载结构的动载荷进行了研究。建立了考虑平台车射击时轴承结构运动的数学模型。有人认为，平台车装载了两门高射炮。在Mathcad编程环境下求解数学模型。这项研究是在平面坐标系下进行的。我们已经确定了作用在平台式货车的轴承结构上的加速度。在这种情况下，最大加速度在弹跳振荡时约为3.6 m/s 2，在飞奔振荡时约为4.0 m/s 2。换句话说，考虑到所提出的技术解决方案，平台车在垂直平面上的轴承结构在射击时的动载荷降低了近30%。在这种情况下，加速度的大小几乎与发射角度无关。在确定平台式货车承载结构的强度指标时，考虑了推导出的加速度值。在CosmosWorks编程环境下，采用有限元法进行计算。平台式货车承载结构的最大等效应力约为285 MPa;它们集中在承载结构支承在小车上的区域。从而保证了平台车承载结构的耐久性。对平台式货车的轴承结构进行了模态分析。固有振荡频率值在允许范围内。我们的研究将有助于设计出新颖的平台式货车结构
{"title":"Determining the Features of Loading the Improved Bearing Structure of a Platform Wagon for the Transportation of Military Equipment","authors":"A. Lovska, O. Fomin, Anna Chechet, O. Soloviova","doi":"10.15587/1729-4061.2020.203245","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.203245","url":null,"abstract":"The paper reports the improvement in the bearing structure of a platform wagon that transports military equipment and is involved in artillery fire. A special feature of the platform wagon is the presence of rotary sectors made from a composite material with viscous or elastic-viscous links, which makes it possible to absorb the kinetic energy that is transmitted to the frame when firing from the wagon, as well as enables the loading/unloading of military equipment from its side. We have investigated the dynamic loading of the bearing structure of a platform wagon for military equipment transportation and combat operations. A mathematical model has been constructed, which takes into consideration the movement of the bearing structure of a platform wagon when firing from it. It has been considered that the platform wagon is loaded with two anti-aircraft guns. The mathematical model was solved in the Mathcad programming environment. The study was conducted in a flat coordinate system. We have determined the accelerations that act on the bearing structure of a platform wagon. The maximum acceleration rate, in this case, is about 3.6 m/s 2 at bouncing oscillations and 4.0 m/s 2 at galloping oscillations. In other words, considering the proposed technical solutions, the dynamic loading of the bearing structure of a platform wagon in the vertical plane at firing decreases by almost 30 %. The magnitude of the acceleration is almost independent of the firing angle in this case. The derived acceleration values have been taken into consideration in determining the strength indicators for the bearing structure of a platform wagon. Calculation was carried out by the method of finite elements in the CosmosWorks programming environment. The maximum equivalent stresses in the bearing structure of a platform wagon amounted to about 285 MPa; they are concentrated in the region where the bearing structure rests on the trolley. Consequently, the durability of the bearing structure of a platform wagon is ensured. Modal analysis of the bearing structure of a platform wagon has been conducted. The values of the natural oscillation frequencies are within allowable limits. Our research would contribute to designing innovative structures for platform wagons","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84653104","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}
Y. Sasaki, K. Morita, Takahisa Yamamoto, K. Soga, H. Masuda, H. Yoshida
Electric DC current dependence on the superplastic flow in densified, fine-grained tetragonal ZrO2 polycrystal was systematically investigated. An optimal current density for large tensile ductility existed; the maximum elongation of 135% was achieved under the current density of 250 mA∙mm-2 at a furnace temperature of 1000 oC and an initial strain rate of 1×10-3 s-1. Application of DC current decreased the flow stress, while that simultaneously accelerated the grain growth in tetragonal ZrO2 polycrystal. The reduced flow stress and improved ductility can be explained not only by Joule heating but also by enhanced atomic diffusion or accelerated grain boundary sliding.
{"title":"Electric Current Dependence on Superplastic Tensile Flow in Tetragonal Zirconia Polycrystal Under a DC Field","authors":"Y. Sasaki, K. Morita, Takahisa Yamamoto, K. Soga, H. Masuda, H. Yoshida","doi":"10.2139/ssrn.3622581","DOIUrl":"https://doi.org/10.2139/ssrn.3622581","url":null,"abstract":"Electric DC current dependence on the superplastic flow in densified, fine-grained tetragonal ZrO2 polycrystal was systematically investigated. An optimal current density for large tensile ductility existed; the maximum elongation of 135% was achieved under the current density of 250 mA∙mm-2 at a furnace temperature of 1000 oC and an initial strain rate of 1×10-3 s-1. Application of DC current decreased the flow stress, while that simultaneously accelerated the grain growth in tetragonal ZrO2 polycrystal. The reduced flow stress and improved ductility can be explained not only by Joule heating but also by enhanced atomic diffusion or accelerated grain boundary sliding.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75306180","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}
Pub Date : 2020-06-15DOI: 10.48216/9788269203325ch5
J. Lamb
Biomass is a generic word used to characterise all matter created naturally. Therefore, it contains all sorts of materials and substances extracted from living organisms. Forest and farm biomass, commercial and urban residues and waste are the sources of biomass used as a bioenergy feedstock. Biomass resources suitable as biogas feedstocks, usually referred to as anaerobic digestion feedstocks, are represented by a wide variety of renewable organic materials available, ranging from simple compounds to complex high-solid substrates. They usually have a high content of sugar, starch, proteins or fats, and their ability to be easily decomposed through anaerobic digestion is a common feature. This chapter gives an overview of biomass sources for anaerobic digestion as well as their important characteristics.
{"title":"Feedstocks for AD","authors":"J. Lamb","doi":"10.48216/9788269203325ch5","DOIUrl":"https://doi.org/10.48216/9788269203325ch5","url":null,"abstract":"Biomass is a generic word used to characterise all matter created naturally. Therefore, it contains all sorts of materials and substances extracted from living organisms. Forest and farm biomass, commercial and urban residues and waste are the sources of biomass used as a bioenergy feedstock. Biomass resources suitable as biogas feedstocks, usually referred to as anaerobic digestion feedstocks, are represented by a wide variety of renewable organic materials available, ranging from simple compounds to complex high-solid substrates. They usually have a high content of sugar, starch, proteins or fats, and their ability to be easily decomposed through anaerobic digestion is a common feature. This chapter gives an overview of biomass sources for anaerobic digestion as well as their important characteristics.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76299903","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}
Su-Qin Zhu, H. Shih, Xiangyuan Cui, Chung-Yi Yu, S. Ringer
Solute clustering is a technologically important microstructural process in Al alloys. Exerting control over this process in order to enhance the alloy properties and reduce the energy costs of production is a major scientific and technological focus, with automotive sheet applications serving as a key driver. In this work, we detail changes in the state of clustering arising from the insertion of a thermomechanical pre-ageing process, via a coiling step, immediately after solution treatment. This pre-ageing step effectively mitigates the negative effects of the natural ageing on the mechanical properties that would otherwise occur after solution treatment and ahead of the final paint-bake step. Our work sought to raise the strength of AA6016, which nominally contains little or no Cu, to levels equivalent to the higher Cu-bearing 6xxx grade alloys, whilst preserving excellent ductility. This novel combination of process design and alloy selection has been studied in detail using a combination of atom probe tomography (APT) and first principles density functional theory (DFT) simulations. The thermomechanical process described here invokes a strong cluster strengthening phenomenon. We report on the details of the single-species Si-Si and Mg-Mg clusters and those of the Mg-Si co-clusters and relate the APT observations to our DFT calculations. Mg-Si co-clusters ≥ 20 solute atoms are found to be responsible for the excellent properties in the material exposed to the pre-ageing and paint-baking process. Our results revealed that vacancies can effectively stabilise single-species Si clusters enabling them to attract further solute and serving as a pathway to formation of the larger Mg-Si co-clusters that are so beneficial to alloy properties.
{"title":"Design of Solute Clustering During Thermomechanical Processing of AA6016 Al-Mg-Si Alloy","authors":"Su-Qin Zhu, H. Shih, Xiangyuan Cui, Chung-Yi Yu, S. Ringer","doi":"10.2139/ssrn.3614851","DOIUrl":"https://doi.org/10.2139/ssrn.3614851","url":null,"abstract":"Solute clustering is a technologically important microstructural process in Al alloys. Exerting control over this process in order to enhance the alloy properties and reduce the energy costs of production is a major scientific and technological focus, with automotive sheet applications serving as a key driver. In this work, we detail changes in the state of clustering arising from the insertion of a thermomechanical pre-ageing process, via a coiling step, immediately after solution treatment. This pre-ageing step effectively mitigates the negative effects of the natural ageing on the mechanical properties that would otherwise occur after solution treatment and ahead of the final paint-bake step. Our work sought to raise the strength of AA6016, which nominally contains little or no Cu, to levels equivalent to the higher Cu-bearing 6xxx grade alloys, whilst preserving excellent ductility. This novel combination of process design and alloy selection has been studied in detail using a combination of atom probe tomography (APT) and first principles density functional theory (DFT) simulations. The thermomechanical process described here invokes a strong cluster strengthening phenomenon. We report on the details of the single-species Si-Si and Mg-Mg clusters and those of the Mg-Si co-clusters and relate the APT observations to our DFT calculations. Mg-Si co-clusters ≥ 20 solute atoms are found to be responsible for the excellent properties in the material exposed to the pre-ageing and paint-baking process. Our results revealed that vacancies can effectively stabilise single-species Si clusters enabling them to attract further solute and serving as a pathway to formation of the larger Mg-Si co-clusters that are so beneficial to alloy properties.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84794407","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}
Lei Tang, Zemin Li, Kepi Chen, Cuiwei Li, Xiaowen Zhang, L. An
High-entropy oxides (HEOs) are a new class of materials that are promising for a wide range of applications. Designing HEOs needs to consider both geometric compatibility and electrical equilibrium. However, there is currently no available method to systematically consider these two factors when selecting constituent materials for making HEOs. Here we propose a two-step strategy, where a HEO system to be explored is first partitioned into multiple subsystems based on the valence combinations of substituted cations; the geometric compatibility is then considered in selecting suitable substituted cations. We demonstrate this strategy by using A(5B0.2)O3 perovskite as a model system. We show that the system can be partitioned into 12 subsystems. Ten of the subsystems have formed a single-phase cubic perovskite, while two have partially ordering structure. The formation of single phases is correlated to Goldschmidt's tolerance factor, while the formation of the ordering structure is mainly correlated to cation-valence difference. We anticipate that this strategy is applicable to exploring HEOs in other systems.
{"title":"High-Entropy Oxides Based on Valence Combinations: Design and Practice","authors":"Lei Tang, Zemin Li, Kepi Chen, Cuiwei Li, Xiaowen Zhang, L. An","doi":"10.2139/ssrn.3656143","DOIUrl":"https://doi.org/10.2139/ssrn.3656143","url":null,"abstract":"High-entropy oxides (HEOs) are a new class of materials that are promising for a wide range of applications. Designing HEOs needs to consider both geometric compatibility and electrical equilibrium. However, there is currently no available method to systematically consider these two factors when selecting constituent materials for making HEOs. Here we propose a two-step strategy, where a HEO system to be explored is first partitioned into multiple subsystems based on the valence combinations of substituted cations; the geometric compatibility is then considered in selecting suitable substituted cations. We demonstrate this strategy by using A(5B0.2)O3 perovskite as a model system. We show that the system can be partitioned into 12 subsystems. Ten of the subsystems have formed a single-phase cubic perovskite, while two have partially ordering structure. The formation of single phases is correlated to Goldschmidt's tolerance factor, while the formation of the ordering structure is mainly correlated to cation-valence difference. We anticipate that this strategy is applicable to exploring HEOs in other systems.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91183974","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}
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