A thermodynamic model for cellular glass pore-formation has been developed on the basis of natural volcanic silicate and aluminosilicate glasses. The energy expenses for heating the materials, chemical reactions, breaking the structural bonds of water hydrates, evaporation of the released water, and pore formation of the glass mass are determined sequentially. The enthalpy and Gibbs energy of the complex gas-forming agent HNO3 + SiC are calculated.
{"title":"The Energy Potential of Glassy Volcanic Rock for Cellular Glass Production","authors":"E. Sahakyan, M. Kalantaryan","doi":"10.4028/p-k7qq41","DOIUrl":"https://doi.org/10.4028/p-k7qq41","url":null,"abstract":"A thermodynamic model for cellular glass pore-formation has been developed on the basis of natural volcanic silicate and aluminosilicate glasses. The energy expenses for heating the materials, chemical reactions, breaking the structural bonds of water hydrates, evaporation of the released water, and pore formation of the glass mass are determined sequentially. The enthalpy and Gibbs energy of the complex gas-forming agent HNO3 + SiC are calculated.","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"20 1","pages":"3 - 8"},"PeriodicalIF":0.0,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81567050","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}
M. Najim, A. Jabur, Ahmed Majeed Al-Shammari, Emad S. Al Hassani, Waleed A. H. Al Nasir, Khansaa Raad
In this study, a synthetic scaffold was prepared from polycaprolactone (PCL) and polyurethane (PU) blend, in a ratio of [2:1] [PCL: PU], using electrospinning technique. Electrospun scaffolds from native PCL and PU were also prepared for comparison, using the same polymer concentration 15% weight/ volume w/v. The detailed microstructure and other properties, like mechanical properties, porosity, and contact angle were investigated and compared between the three prepared scaffolds. Then, the survival, adhesion, proliferation and penetration of rat embryonic fibroblast (REF) cells were evaluated on these three prepared scaffolds after being in vitro cultured with these cells for 21 days, using scanning electron microscope (SEM) analysis and histological analysis. The results showed that, all the studied properties, including mechanical properties and contact angle were enhanced by combining PU with PCL in the [PCL: PU] scaffold. The average diameter of fiber and the average size of pore were suitable and proper for cell attachment, cell proliferation, and also the big average pore size in [PCL: PU] scaffold was enough for cell penetration to form a three- dimension 3-D structure, which is the aim of this study.
{"title":"Preparation and Characterization of an Electrospun Polycaprolactone/Polyurethane Scaffold for Soft Tissue Applications","authors":"M. Najim, A. Jabur, Ahmed Majeed Al-Shammari, Emad S. Al Hassani, Waleed A. H. Al Nasir, Khansaa Raad","doi":"10.4028/p-ez646s","DOIUrl":"https://doi.org/10.4028/p-ez646s","url":null,"abstract":"In this study, a synthetic scaffold was prepared from polycaprolactone (PCL) and polyurethane (PU) blend, in a ratio of [2:1] [PCL: PU], using electrospinning technique. Electrospun scaffolds from native PCL and PU were also prepared for comparison, using the same polymer concentration 15% weight/ volume w/v. The detailed microstructure and other properties, like mechanical properties, porosity, and contact angle were investigated and compared between the three prepared scaffolds. Then, the survival, adhesion, proliferation and penetration of rat embryonic fibroblast (REF) cells were evaluated on these three prepared scaffolds after being in vitro cultured with these cells for 21 days, using scanning electron microscope (SEM) analysis and histological analysis. The results showed that, all the studied properties, including mechanical properties and contact angle were enhanced by combining PU with PCL in the [PCL: PU] scaffold. The average diameter of fiber and the average size of pore were suitable and proper for cell attachment, cell proliferation, and also the big average pore size in [PCL: PU] scaffold was enough for cell penetration to form a three- dimension 3-D structure, which is the aim of this study.","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"1 1","pages":"75 - 87"},"PeriodicalIF":0.0,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81845896","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}
In this study, high-cost Cr and Ni components of 202 austenitic stainless steel were reduced, low-cost Mn was added, and the amount of martensite and the mechanical properties were evaluated according to the rolling temperature and rolling degree. Part of the austenite was deformed by rolling into α′-martensite. As the rolling degree was increased, more martensite was generated; and at the same rolling degree, as the rolling temperature decreased, more martensite was generated. Up to a rolling degree of 33 %, the amount of martensite rapidly increased; thereafter, it gradually increased. In particular, the amount of martensite at a rolling temperature of-196 °C was similar to that after the rolling degree of 33 %. As the rolling temperature decreased and the rolling degree increased, both the Vickers hardness and tensile (yield) strength increased, while the elongation rapidly decreased.
{"title":"Mechanical Properties of 202 Austenitic Stainless Steel Depending on Rolling Temperature and Rolling Degree","authors":"Gum-Hwa Lee, Hyun-Bae Jeon, K. Nam","doi":"10.4028/p-or148u","DOIUrl":"https://doi.org/10.4028/p-or148u","url":null,"abstract":"In this study, high-cost Cr and Ni components of 202 austenitic stainless steel were reduced, low-cost Mn was added, and the amount of martensite and the mechanical properties were evaluated according to the rolling temperature and rolling degree. Part of the austenite was deformed by rolling into α′-martensite. As the rolling degree was increased, more martensite was generated; and at the same rolling degree, as the rolling temperature decreased, more martensite was generated. Up to a rolling degree of 33 %, the amount of martensite rapidly increased; thereafter, it gradually increased. In particular, the amount of martensite at a rolling temperature of-196 °C was similar to that after the rolling degree of 33 %. As the rolling temperature decreased and the rolling degree increased, both the Vickers hardness and tensile (yield) strength increased, while the elongation rapidly decreased.","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"53 18 1","pages":"99 - 106"},"PeriodicalIF":0.0,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75408199","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}
Nair Khiloun, N. Elmeiche, Hichem Abbad, I. Mechab
The present study aims to carry out a parametric investigation on a pile made of different materials, and subjected to static and dynamic loading resulting from the weight of the structure and the shear force acting on the head of the pile. It is worth specifying that the pile is anchored in the ground on a Winkler-Pasternak elastic foundation that is made up of five different layers. In this study, the equilibrium equations were treated using the high-order theory with a new shear deformation shape function of a cylindrical pile made of an isotropic material and a sandwich functionally graded material.The results obtained with a numerical study based on the minimization of energies by the Rayleigh-Ritz method was carried out in order to highlight the influence of the geometric ratio, the volume fraction of the functionally graded material, and the type of loading on the vibration frequencies and the admissible stresses in order to determine the most appropriate material for the pile so that extreme stresses can be absorbed. The precision and the applicability of the method with new solution of the transverse shear deformation are demonstrated through this study with modeling of the layered property of the soil, were then compared with those reported in previous work available in the literature. It turned out that these results are in good agreement with each other, for the different materials of pile and for all boundary conditions considered. The results of pile with sandwich functionally graded material, it is revealed that the role of this material has an influence on the type of loading, especially, in the case statique of a pile subjected to a compound bending weight and the shear effect, in case dynamique the pile with vibration flexible or rigid .
{"title":"Bending and Free Vibration Analysis of Functionally Graded Sandwich Pile on Elastic Foundation Using Rayleigh-Ritz Method","authors":"Nair Khiloun, N. Elmeiche, Hichem Abbad, I. Mechab","doi":"10.4028/p-5h29l1","DOIUrl":"https://doi.org/10.4028/p-5h29l1","url":null,"abstract":"The present study aims to carry out a parametric investigation on a pile made of different materials, and subjected to static and dynamic loading resulting from the weight of the structure and the shear force acting on the head of the pile. It is worth specifying that the pile is anchored in the ground on a Winkler-Pasternak elastic foundation that is made up of five different layers. In this study, the equilibrium equations were treated using the high-order theory with a new shear deformation shape function of a cylindrical pile made of an isotropic material and a sandwich functionally graded material.The results obtained with a numerical study based on the minimization of energies by the Rayleigh-Ritz method was carried out in order to highlight the influence of the geometric ratio, the volume fraction of the functionally graded material, and the type of loading on the vibration frequencies and the admissible stresses in order to determine the most appropriate material for the pile so that extreme stresses can be absorbed. The precision and the applicability of the method with new solution of the transverse shear deformation are demonstrated through this study with modeling of the layered property of the soil, were then compared with those reported in previous work available in the literature. It turned out that these results are in good agreement with each other, for the different materials of pile and for all boundary conditions considered. The results of pile with sandwich functionally graded material, it is revealed that the role of this material has an influence on the type of loading, especially, in the case statique of a pile subjected to a compound bending weight and the shear effect, in case dynamique the pile with vibration flexible or rigid .","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"6 1","pages":"47 - 64"},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80287734","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}
In this work, the adhesion and corrosion resistance of TiN coating by magnetron sputtering on stainless steel substrates under different bias voltages conditions (-50 V and-100 V) was investigated. AFM was used for surface roughness and grain size analysis, XRD for phase identification, Rockwell C for adhesion and nanoindentation for hardness and elastic modulus. According to AFM the coating deposited at-100V bias had decreased surface roughness, the value decreased from 2.7 nm (for-50V sample) to 1.8 nm, this was due to an etching like process which occurs when ions with higher energies start hitting the surface. The coated samples came under HF1 adhesion parameter which is the highest class of adhesion in the model on the basis of Rockwell C adhesion test. nanoindentation hardness and elastic modulus results of-50 V and-100V were found to be 224 GPa and 182 GPa, respectively and the value of hardness, 16 GPa and 22 GPa, respectively. The corrosion behavior of TiN coatings were studied in 3.5wt. % NaCl solutions using Tafel Extrapolation, Cyclic Polarization and Open Circuit Potential. It was noted on the basis of these corrosion tests that, as bias voltage is increased, it leads to the formation of more densely packed, fine grained columnar structures with less pores, which decreases the chances of corrosion. .
{"title":"Effect of Bias Voltage on Adhesion and Corrosion Resistance of Titanium Nitride Coated Stainless Steel Substrate","authors":"Talha Faizi, Abdullah Khan, R. Ali","doi":"10.4028/p-nf315p","DOIUrl":"https://doi.org/10.4028/p-nf315p","url":null,"abstract":"In this work, the adhesion and corrosion resistance of TiN coating by magnetron sputtering on stainless steel substrates under different bias voltages conditions (-50 V and-100 V) was investigated. AFM was used for surface roughness and grain size analysis, XRD for phase identification, Rockwell C for adhesion and nanoindentation for hardness and elastic modulus. According to AFM the coating deposited at-100V bias had decreased surface roughness, the value decreased from 2.7 nm (for-50V sample) to 1.8 nm, this was due to an etching like process which occurs when ions with higher energies start hitting the surface. The coated samples came under HF1 adhesion parameter which is the highest class of adhesion in the model on the basis of Rockwell C adhesion test. nanoindentation hardness and elastic modulus results of-50 V and-100V were found to be 224 GPa and 182 GPa, respectively and the value of hardness, 16 GPa and 22 GPa, respectively. The corrosion behavior of TiN coatings were studied in 3.5wt. % NaCl solutions using Tafel Extrapolation, Cyclic Polarization and Open Circuit Potential. It was noted on the basis of these corrosion tests that, as bias voltage is increased, it leads to the formation of more densely packed, fine grained columnar structures with less pores, which decreases the chances of corrosion. .","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"15 1","pages":"103 - 112"},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88464357","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}
The main objective of this study was to investigate the influence of using magnetized water on the mechanical properties and durability behavior in terms of freeze-thaw resistance of recycled aggregate concrete. In addition to the effect of different numbers of water rounds in the magnetic field, other variables including steel fibers, super-plasticizers and silica-fume were considered in the concrete production in order to achieve the ideal possible performance for recycled aggregate concrete made with 100% coarse aggregates replacements. For this purpose, a total of 11 concrete mixes were prepared and tested. At the first step, the effects of the mentioned variables on the basic properties, including workability, water absorption, compressive strength, splitting tensile strength, flexural strength and freeze-thaw durability test were investigated. Additionally, flexural toughness was evaluated in accordance with the post-crack strength (PCS) method and the microstructure of concrete specimens was also observed by using scanning electron microscope (SEM). The results of most experiments indicated that magnetized water, although highly effective on the mechanical properties of concrete, should not be solely utilized as a compensating factor for the defects caused by recycled coarse aggregates. The optimum toughness and durability results regarding the fiber-reinforced concrete mixes produced with recycled coarse aggregates, were related to samples containing silica-fume and 10-rounds magnetized water. Furthermore, the existence of cement replaced by 10% of silica-fume and 10-rounds magnetized water in the concrete mix MW-SF2, increased the durability of the recycled aggregate concrete by an average of approximately 63%.
{"title":"Influence of Magnetized Water on Mechanical Properties and Durability of Recycled Aggregate Concrete","authors":"A. Youssef, M. Esfahani","doi":"10.4028/p-s2t9nl","DOIUrl":"https://doi.org/10.4028/p-s2t9nl","url":null,"abstract":"The main objective of this study was to investigate the influence of using magnetized water on the mechanical properties and durability behavior in terms of freeze-thaw resistance of recycled aggregate concrete. In addition to the effect of different numbers of water rounds in the magnetic field, other variables including steel fibers, super-plasticizers and silica-fume were considered in the concrete production in order to achieve the ideal possible performance for recycled aggregate concrete made with 100% coarse aggregates replacements. For this purpose, a total of 11 concrete mixes were prepared and tested. At the first step, the effects of the mentioned variables on the basic properties, including workability, water absorption, compressive strength, splitting tensile strength, flexural strength and freeze-thaw durability test were investigated. Additionally, flexural toughness was evaluated in accordance with the post-crack strength (PCS) method and the microstructure of concrete specimens was also observed by using scanning electron microscope (SEM). The results of most experiments indicated that magnetized water, although highly effective on the mechanical properties of concrete, should not be solely utilized as a compensating factor for the defects caused by recycled coarse aggregates. The optimum toughness and durability results regarding the fiber-reinforced concrete mixes produced with recycled coarse aggregates, were related to samples containing silica-fume and 10-rounds magnetized water. Furthermore, the existence of cement replaced by 10% of silica-fume and 10-rounds magnetized water in the concrete mix MW-SF2, increased the durability of the recycled aggregate concrete by an average of approximately 63%.","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"5 1","pages":"25 - 46"},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79182623","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}
Hicham Elidrissi, Wafaa Borja, L. Daoudi, N. Fagel, R. Hakkou, Y. Taha, Y. Tamraoui
Fired bricks have shown tremendous potential as a construction material due to their properties. However, their use required some specifications in terms of quality, resistance, and durability. In developing countries, the lack of tools to make test specimens leads to many defects in these brick specimens responsible for low durability and weak precision during mechanical tests and shrinkage. In this study, a simple and traditional method of making test bricks is presented. This simple method allows the production of bricks with the required properties. This method is especially efficient for semi-soft consistency pastes. The elaborated handmade pastes present a very different particle-size distribution < 2 mm (clay: 18-66%; silt: 12-53%; sand: 5-65%). The pastes do not stick to the walls of the mould like in the case of steel moulds, and it gives specimens with standard shape, smooth surface, and sharp edges. The resulting fired bricks exhibit high mechanical strength (up to 102 MPa for the compressive strength, and up to 28 MPa for the flexural strength) comparable to and even better than those of conventional methods. The elaborated bricks allowed also the measurement of very important parameters such as drying and firing shrinkage, drying, and firing weight loss, and porosity.
{"title":"An Easy Way for Ceramic Bricks Elaboration to Carry out Basic Technical Measurements","authors":"Hicham Elidrissi, Wafaa Borja, L. Daoudi, N. Fagel, R. Hakkou, Y. Taha, Y. Tamraoui","doi":"10.4028/p-e218c0","DOIUrl":"https://doi.org/10.4028/p-e218c0","url":null,"abstract":"Fired bricks have shown tremendous potential as a construction material due to their properties. However, their use required some specifications in terms of quality, resistance, and durability. In developing countries, the lack of tools to make test specimens leads to many defects in these brick specimens responsible for low durability and weak precision during mechanical tests and shrinkage. In this study, a simple and traditional method of making test bricks is presented. This simple method allows the production of bricks with the required properties. This method is especially efficient for semi-soft consistency pastes. The elaborated handmade pastes present a very different particle-size distribution < 2 mm (clay: 18-66%; silt: 12-53%; sand: 5-65%). The pastes do not stick to the walls of the mould like in the case of steel moulds, and it gives specimens with standard shape, smooth surface, and sharp edges. The resulting fired bricks exhibit high mechanical strength (up to 102 MPa for the compressive strength, and up to 28 MPa for the flexural strength) comparable to and even better than those of conventional methods. The elaborated bricks allowed also the measurement of very important parameters such as drying and firing shrinkage, drying, and firing weight loss, and porosity.","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"101 1","pages":"3 - 14"},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73850112","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}
Plastic waste disposal is among the most challenging problems of the current era. Therefore, new methods and applications for the utilization of waste plastics are increasingly needed. To find them, it is essential to research and develop the material properties of recycled plastics. The effect of different ultraviolet light (UV) stabilizers on the color stability, melt properties and tensile properties of mixed waste plastics blends was studied in this paper. The mixed waste plastics collected from two different waste sources were prepared as specimens by injection molding, and studied with two different types and loading amounts of UV stabilizers. UV absorbers (UVAs) and hindered amine light stabilizers (HALS) were used as UV stabilizers. A specimen produced without the addition of a UV stabilizer was used as a reference specimen of both the blends. After the accelerated weathering, the addition of a UVA provided an improved, smaller change in color than the addition of HALS. Among the tensile properties, the addition of UV stabilizers clearly improved the tensile strength and tensile modulus for almost all the studied specimens. Additionally, the melt properties of both the studied plastic blends were found to be increased by the addition of UV stabilizers.
{"title":"The Effect of Ultraviolet Light Stabilizers on Color Stability, Melt Properties and Tensile Properties of Mixed Waste Plastics Blends","authors":"M. Hyvärinen, Viktor Lagern, T. Kärki","doi":"10.4028/p-c8f808","DOIUrl":"https://doi.org/10.4028/p-c8f808","url":null,"abstract":"Plastic waste disposal is among the most challenging problems of the current era. Therefore, new methods and applications for the utilization of waste plastics are increasingly needed. To find them, it is essential to research and develop the material properties of recycled plastics. The effect of different ultraviolet light (UV) stabilizers on the color stability, melt properties and tensile properties of mixed waste plastics blends was studied in this paper. The mixed waste plastics collected from two different waste sources were prepared as specimens by injection molding, and studied with two different types and loading amounts of UV stabilizers. UV absorbers (UVAs) and hindered amine light stabilizers (HALS) were used as UV stabilizers. A specimen produced without the addition of a UV stabilizer was used as a reference specimen of both the blends. After the accelerated weathering, the addition of a UVA provided an improved, smaller change in color than the addition of HALS. Among the tensile properties, the addition of UV stabilizers clearly improved the tensile strength and tensile modulus for almost all the studied specimens. Additionally, the melt properties of both the studied plastic blends were found to be increased by the addition of UV stabilizers.","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"19 1","pages":"91 - 102"},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76487117","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}
This study employs 2D finite element modeling using Plaxis to investigate the behavior of the railway embankment constructed on the active Ganges-Bramhaputra floodplain. The parametric study considers three different train speeds, 100, 120, and 170 km/hr, and two different soil profiles along different chainages, chainage 82 km+183 m (Ch1) and 84 km+102 m (Ch2) of Padma Bridge Rail Link. Pseudo-static trainloads have been applied and the settlement of the ballast bottom (BB) and embankment bottom (EB) have been determined and compared along with the factor of safety (FS). From the obtained results, the maximum settlement of EB in Ch1 ranged between 27.45 cm to 29.2 cm which is lower by 9.2 cm from Ch2 on average. For BB, greater settlements have been observed as they varied between 33.25 cm to 36.20 cm for Ch1 and 42.80 cm to 45.31 cm for Ch2. Thus in both cases, Ch2 shows greater settlements. Also in both chainages, the settlements exceed the allowable range. As the train speed increases from 100 to 170 km/hr, the increase in the settlement is noticeable for the ballast bottom but not for the embankment bottom. Considering the FS, the embankments are assessed to be safe in all considered cases with an FS> 1.2, without any significant effect of train speeds.
本研究采用Plaxis的二维有限元模型来研究在活跃的恒河-布拉马普特拉河漫滩上建造的铁路路堤的行为。参数化研究考虑了三种不同的列车速度，分别为100、120和170 km/hr，以及沿Padma大桥铁路线82 km+183 m (Ch1)和84 km+102 m (Ch2)不同路段的两种不同土壤剖面。采用列车拟静力载荷，测定了路基底部和道砟底部的沉降量，并与安全系数进行了比较。结果表明，EB在Ch1中的最大沉降在27.45 ~ 29.2 cm之间，比Ch2平均低9.2 cm。对于BB, Ch1的沉降量在33.25 cm到36.20 cm之间，Ch2的沉降量在42.80 cm到45.31 cm之间。因此在这两种情况下，Ch2都表现出更大的沉降。而且在两个链中，沉降都超过了允许的范围。当列车速度从100 km/hr增加到170 km/hr时，道砟底部沉降增加明显，而路堤底部沉降增加不明显。考虑到FS，在所有考虑的FS> 1.2的情况下，路堤被评估为安全的，没有任何列车速度的显着影响。
{"title":"Behavior of Railway Embankment Constructed on Soft Deltaic Deposits under Varying Train Speeds","authors":"Shamontee Aziz, Joyashree Mallick, Iram Lamiya Hoque, Md. Arifuzzaman Nayeem, A. Amin","doi":"10.4028/p-j7627z","DOIUrl":"https://doi.org/10.4028/p-j7627z","url":null,"abstract":"This study employs 2D finite element modeling using Plaxis to investigate the behavior of the railway embankment constructed on the active Ganges-Bramhaputra floodplain. The parametric study considers three different train speeds, 100, 120, and 170 km/hr, and two different soil profiles along different chainages, chainage 82 km+183 m (Ch1) and 84 km+102 m (Ch2) of Padma Bridge Rail Link. Pseudo-static trainloads have been applied and the settlement of the ballast bottom (BB) and embankment bottom (EB) have been determined and compared along with the factor of safety (FS). From the obtained results, the maximum settlement of EB in Ch1 ranged between 27.45 cm to 29.2 cm which is lower by 9.2 cm from Ch2 on average. For BB, greater settlements have been observed as they varied between 33.25 cm to 36.20 cm for Ch1 and 42.80 cm to 45.31 cm for Ch2. Thus in both cases, Ch2 shows greater settlements. Also in both chainages, the settlements exceed the allowable range. As the train speed increases from 100 to 170 km/hr, the increase in the settlement is noticeable for the ballast bottom but not for the embankment bottom. Considering the FS, the embankments are assessed to be safe in all considered cases with an FS> 1.2, without any significant effect of train speeds.","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"17 1","pages":"81 - 88"},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86102201","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}
The elastic and structural properties of Aluminum-doped Gallium Arsenide at different pressure have been investigated by using the first-principles density functional theory. In order to calculate the exchange correlation potentials, the exchange and correlation potential is determined by the generalized gradient approximation parameterized by Perdew Burke Ernzerhof and local density approximation. The results showed the decrease of the lattice constants with increasing pressure and the bulk modulus increase from increasing pressure of binary Gallium Arsenide and their ternary alloy by both the approximations mentioned above. This results show a good agreement is found between the theoretical and the experimental available data. The elastic constants, Young modulus, Bulk modulus, Shear modulus, Poisson’s ratio and Debye temperatures of Gallium Arsenide binary and their ternary alloy as function of pressure have been calculated for the first time. The results provide a theoretical reference for doping of Gallium Arsenide with Aluminum atom at different pressures.
{"title":"Pressure Effects on the Structural, Elastic Properties and Mechanical Parameters of Al-Doped GaAs","authors":"F. Okbi, K. Almi, S. Lakel","doi":"10.4028/p-26n0r9","DOIUrl":"https://doi.org/10.4028/p-26n0r9","url":null,"abstract":"The elastic and structural properties of Aluminum-doped Gallium Arsenide at different pressure have been investigated by using the first-principles density functional theory. In order to calculate the exchange correlation potentials, the exchange and correlation potential is determined by the generalized gradient approximation parameterized by Perdew Burke Ernzerhof and local density approximation. The results showed the decrease of the lattice constants with increasing pressure and the bulk modulus increase from increasing pressure of binary Gallium Arsenide and their ternary alloy by both the approximations mentioned above. This results show a good agreement is found between the theoretical and the experimental available data. The elastic constants, Young modulus, Bulk modulus, Shear modulus, Poisson’s ratio and Debye temperatures of Gallium Arsenide binary and their ternary alloy as function of pressure have been calculated for the first time. The results provide a theoretical reference for doping of Gallium Arsenide with Aluminum atom at different pressures.","PeriodicalId":7271,"journal":{"name":"Advanced Materials Research","volume":"76 1","pages":"113 - 122"},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75713541","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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