فهرست مقالات Liquefaction

• دسترسی آزاد مقاله
  • صفحه چکیده
  • متن کامل
  
  1 - Optimization of Process Parameters on Hydrothermal Liquefaction of Sambucus Ebulus for Bio-oil Production
  Amir Hosein Mohseni Hadi Baseri
  Nowadays, the production of bio-oil and chemical intermediates from renewable energy sources isvery important because of growing concerns about climate and environmental changes. In thiswork, the thermal liquefaction of Sambucus ebulus (Danewort plant) is studied with a چکیده کامل

  Nowadays, the production of bio-oil and chemical intermediates from renewable energy sources isvery important because of growing concerns about climate and environmental changes. In thiswork, the thermal liquefaction of Sambucus ebulus (Danewort plant) is studied with a focus on theyield and composition of the produced bio-oil. The produced bio-oil was characterized by FTIR,GC, and GC-MS analyses, and more than 35 different chemical components were identified in it.About 60 w% of the produced bio-oil is composed of five chemical components of acetic acid(21.29%), pentanoic acid (19%), acetone (10.64%), neophytadiene (5%), and α-pinene (4.4%). Theeffects of various process parameters of reaction temperature, time, and concentration of solutionmedia on the yield and composition of products were studied. The maximum yield of the producedbio-oil is about 42% in a temperature of 160°C, a reaction time of 2 h, and 0.75 V% of ethyl acetatein the solution media. پرونده مقاله
• دسترسی آزاد مقاله
  • صفحه چکیده
  • متن کامل
  
  2 - Soil Liquefaction Hazard Zonation Map for Kordkuy County, Golsetan Province Using Model SWM
  Mahtab Forootan Esmaeil Silakhori Ehsan Alvandi
  Liquefaction is one of the most determinant factors in the collapse of transportation infrastructures. This is especially true for roads and railroads located on saturated, fine-sand substrates under seismic conditions. The damage and human casualties resulting from liq چکیده کامل

  Liquefaction is one of the most determinant factors in the collapse of transportation infrastructures. This is especially true for roads and railroads located on saturated, fine-sand substrates under seismic conditions. The damage and human casualties resulting from liquefaction highlight the importance of understanding and mapping this phenomenon. Soil liquefaction occurs as a natural hazard in saturated, loose sand due to increased pore pressure and low shear strength. The purpose of this study was to prepare a soil liquefaction hazard zonation map for Kordkuy County, located in Golsetan Province, using data collection, basic digital mapping (soil deposits map, ground water depth and earthquake acceleration map), three parametric Stanford Watershed Models (SWM) and ArcGIS software . An empirical liquefaction model as a function of the three studied variables was used to model liquefaction in four hazard classes using ArcGIS software. According to the results, most areas fall into the nonhazardous and moderately hazardous risk classes. A portion of the Eastern County was classified as highly hazardous due mostly to its close proximity to an earthquake focal point. پرونده مقاله
• دسترسی آزاد مقاله
  • صفحه چکیده
  • متن کامل
  
  3 - Liquefaction Hazard assessment using Horizontal-to-Vertical Spectral Ratio of Microtremor
  Mehdi Mokhberi Sadegh Yazdanpanah Fard
  In this paper, the spectral ratio of mmicrotremor, HSVR, is presented for estimating the liquefaction potential of layered soil in the coastal area of the Persian Gulf, which consists of a hard sandstone layer situated between two saturated sandy layers. The surface lay چکیده کامل

  In this paper, the spectral ratio of mmicrotremor, HSVR, is presented for estimating the liquefaction potential of layered soil in the coastal area of the Persian Gulf, which consists of a hard sandstone layer situated between two saturated sandy layers. The surface layer is thin, with a thickness between 2 and 5 meters. The purpose of this paper is to identify the relation between the liquefaction potential, the natural frequency and the amplification factor values using microtremors. Liquefaction assessment was done at 27 stations using the HVSR approach provided by Nakamura [1]. HVSR analysis was carried out using the Geopsy software. According to the results of the analysis, the predominant frequency values range from about 0.8 Hz to 2.4 Hz and the amplification factor values range from 1.1 to 2.8. Based on these parameters, the vulnerability index Kg is determined, which can be used as a parameter in calculating the liquefaction potential of an area. The results show that the vulnerability index is related to the sedimentary depth as well as the frequency and amplification factor. Furthermore, the calculated results confirm that the southern area of Bushehr City, which is larger than other areas, has a high liquefaction potential. Furthermore, it is possible to determine the limit of Kg to estimate the liquefaction hazard. Comparing the results confirms that in Bushehr, a soil layer is liquefiable if its related Kg value is over 1.7. This value may change with the conditions of the layer and the soil specification. پرونده مقاله
• دسترسی آزاد مقاله
  • صفحه چکیده
  • متن کامل
  
  4 - Multi-Objective Optimization of the Depth and Cementation of Liquefiable Soil Surrounding Tunnels
  Mohammad Shabani Soltan Moradi Mohammad Azadi Homayoun Jahanian
  Designing tunnels in liquefiable sandy soils presents a significant challenge in determining the optimal depth and extent of soil cementation around them. Reducing the depth of the tunnel decreases both the bending anchor force and the axial load on the tunnel's shell, چکیده کامل

  Designing tunnels in liquefiable sandy soils presents a significant challenge in determining the optimal depth and extent of soil cementation around them. Reducing the depth of the tunnel decreases both the bending anchor force and the axial load on the tunnel's shell, yet it leads to an increase in ground surface settlement, and the opposite is true when depth is increased. Enhancing the cementation level at the tunnel's optimal depth reduces both structural uplift and shear forces exerted on the tunnel lining, but it also leads to an increase in axial loads and vice versa. Given the contradictory nature of these outcomes, the FLAC software was employed to simulate tunnels in liquefiable soils to address this dilemma. Subsequently, a neural network was utilized to identify correlations between the inputs and outputs of the simulation. This network was the objective function for identifying optimal values by applying a genetic algorithm. Optimal design parameters were derived using the NSGA-II modified algorithm, a multi-objective optimization technique based on the objective functions. Ultimately, Pareto charts generated from the multi-objective optimization process enabled designers to select the most suitable tunnel location according to their specific requirements concerning depth and soil cementation in liquefied soils. پرونده مقاله