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Shear Strength Reduction Analysis of Slope by Numerical Modelling Based on Finite Element Method
Mahendra Acharya,
Asim Timalsina,
Ujjan Paudel
Issue:
Volume 8, Issue 3, September 2023
Pages:
125-132
Received:
20 May 2023
Accepted:
26 June 2023
Published:
11 July 2023
Abstract: The stability of the slope is the crucial factor in geotechnical engineering, particularly when the slopes are composed of soils. The purpose of this research is to analyze the shear strength reduction of glacial till slope using phase 2 software. Where, conclusive analysis is based on two methods, Limit equilibrium and the Mohr-Colomb criterion Finite Element (FE) Shear Strength Reduction (SSR). The methodology embodied the major laboratory test results such as Atterberg limits, Direct Shear Strength test, unconfined compression strength. The experimental results were than used in phase 2 software, where 2D plane strain model of the slope was created. The impact of modifications in shear strength parameters on the factor of safety is then examined. The analysis showed that the glacial till slope experienced a significant reduction in strength, with the Limit Equilibrium method FOS ranging from 0.94 to 1.54, while Mohr’s criterion Finite Elements Shear Strength Reduction ranged from 0.31 to 0.61. The analysis results, in conclusion, the shear strength reduction of slope is reliable and efficient for determining the stability of slopes. The use of both aforementioned methods provides accurate and consistent results that can aid in making effective engineering decisions.
Abstract: The stability of the slope is the crucial factor in geotechnical engineering, particularly when the slopes are composed of soils. The purpose of this research is to analyze the shear strength reduction of glacial till slope using phase 2 software. Where, conclusive analysis is based on two methods, Limit equilibrium and the Mohr-Colomb criterion Fi...
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Electrical Power Generation from Heat Recovered at the Throat of a Downdraft Biomass Gasifier
Nzihou Jean Fidele,
Hamidou Salou,
Imbga Kossi,
Segda Bila Gerard,
Ouattara Frederic,
Tiemtore Hamadou
Issue:
Volume 8, Issue 3, September 2023
Pages:
133-140
Received:
9 June 2023
Accepted:
10 July 2023
Published:
20 July 2023
Abstract: Gasification, a thermochemical process that takes place in gasifiers, is now understood as a process of transforming the solid components of biomass into combustible gases essentially consisting of carbon monoxide (CO) and dihydrogen (H2). This technology is relatively old and was widely used during the Second World War to deal with the shortage of fossil fuels in Europe. Although gasification was abandoned in favor of oil after the Second World War, this process is experiencing a great revival of interest today for the decentralized production of energy and for covering the energy needs of the disadvantaged strata in the developing countries. We aim to experiment with small-scale gasifiers with three objectives: to produce electrical energy, to improve the energy efficiency of biomass gasifiers and to do so essentially with materials accessible on the market in developing countries at affordable costs. In this study, we successfully designed, fabricated and tested a heat recovery system from a downdraft gasifier fueled with wood chunks. The gasifier use material finds at an affordable cost. Our downdraft gasifiers have a throat which is the hottest part of the apparatus. Almost all designers insulate the throat mainly for safety, environmental protection and efficiency considerations. Instead of insulating the throat, we designed a heat recovery system surrounding the throat and generated electrical power from high pressure water vapor produced from that throat. This recovered energy is a bonus energy from a downdraft gasifier and should be added to the gasifier energy balance, thus increase the overall efficiency This led us to supplemental electrical power generation from this type of gasifiers.
Abstract: Gasification, a thermochemical process that takes place in gasifiers, is now understood as a process of transforming the solid components of biomass into combustible gases essentially consisting of carbon monoxide (CO) and dihydrogen (H2). This technology is relatively old and was widely used during the Second World War to deal with the shortage of...
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The Relationship Between Noise and Temperature to the Level of Work Fatigue in Workers in the Cutting Section
Tri Budiyanto,
M. Yusuf,
Bintang Panjiwani Kusuma As’ari
Issue:
Volume 8, Issue 3, September 2023
Pages:
141-145
Received:
20 June 2023
Accepted:
6 July 2023
Published:
20 July 2023
Abstract: Work fatigue is a decrease in or inability for a person to carry out work activities. Fatigue can occur due to factors in an unsupportive work environment. Workers in the cutting section at Small and medium-sized enterprises (SMEs) Gunungkidul Yogyakarta, Indonesia, carry out the production process in the form of cutting natural stone every day, which is at risk of being exposed to noise and rather high temperatures. Based on the results of the initial measurements, it was found that the level of noise intensity and temperature in the production area exceeded the allowable threshold value. This study aims to determine the relationship between the physical work environment, including noise and temperature, and worker fatigue and then analyze how much influence these factors have and which factors have the most dominant influence on worker fatigue. This study used multiple linear regression methods with randomly selected samples from several SMEs in Gunung Kidul, Yogyakarta. The results showed that the noise factor with a t test value of (4,086 > 2,093) indicated that noise had a positive and significant effect on work fatigue, while the temperature factor, based on the results of the T test, had a calculated T value of (1,787 < 2,093), which means that the temperature has no significant effect on work fatigue. With a coefficient of determination of 0.508 or an effect of 50.8% on worker fatigue.
Abstract: Work fatigue is a decrease in or inability for a person to carry out work activities. Fatigue can occur due to factors in an unsupportive work environment. Workers in the cutting section at Small and medium-sized enterprises (SMEs) Gunungkidul Yogyakarta, Indonesia, carry out the production process in the form of cutting natural stone every day, wh...
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A Modified Approach of Dijkstra’s Method for Finding Shortest Path in a Weighted Directed Graph
Md. Mehedi Hassan,
Md. Asadujjaman,
Md. Golam Robbani
Issue:
Volume 8, Issue 3, September 2023
Pages:
146-151
Received:
8 June 2023
Accepted:
25 June 2023
Published:
31 July 2023
Abstract: The shortest route technique is a fundamental problem in various fields, including transportation, logistics, network routing, and robotics. In this paper, we have discussed a prominent algorithm, namely Dijkstra's algorithm, and propose an alternative method for addressing these problems. A thorough comparison is conducted between the proposed algorithm and Dijkstra's algorithm, considering factors such as solution accuracy and computational efficiency. The experimental results indicate that our proposed method yields identical results to the existing method but with significantly reduced computation time. By leveraging advancements in computational power and algorithmic design, our proposed technique addresses the limitations of existing methods and offers new avenues for optimizing route planning processes. We begin by reviewing the classical algorithms commonly used for solving the shortest route problem, such as Dijkstra's algorithm. While this algorithm has proven its effectiveness over the years, it faces challenges when applied to large-scale networks and real-time applications due to its computational complexity. Our approach incorporates advanced data structures and optimization strategies to efficiently handle massive network graphs. Additionally, we integrate machine learning models to learn from historical data, allowing for the prediction of traffic patterns and considering dynamic factors in route planning.
Abstract: The shortest route technique is a fundamental problem in various fields, including transportation, logistics, network routing, and robotics. In this paper, we have discussed a prominent algorithm, namely Dijkstra's algorithm, and propose an alternative method for addressing these problems. A thorough comparison is conducted between the proposed alg...
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Hydraulic Performance Evaluation of Diversion Weir and Canal Structures: Case Study of Basaka Small Scale Irrigation Scheme, Wayu Tuka, East Wallaga, Oromia, Ethiopia
Gemechu Mosisa,
Dereje Adeba
Issue:
Volume 8, Issue 3, September 2023
Pages:
152-161
Received:
14 July 2023
Accepted:
8 August 2023
Published:
22 August 2023
Abstract: Hydraulic Performance evaluation of the irrigation system is important to conserve scarce water resources by improving the performance of the existing irrigation structure. However, there was no study in the past performance evaluation of the Basaka scheme, which is used for irrigation purposes. This study was to evaluate the hydraulic performance of the diversion weir and the canal structures by using hydraulic performance indicators, conveyance indicators, and maintenance indicators. The primary data collected were direct field measurements in the canals and direct field observations of function & mal-function structures. The secondary data was also taken from the designed document scheme and the journals. The study was carried out during the one irrigation season from February to April 2023. The data collected was analyzed using empirical equations. A diversion weir structure is unsafe for the passage of high floods because the discharge capacity of the weir (227.8m3/s) is relatively lower than the peak design discharge (234m3/s) that is generated from catchment areas. The current intake gate water withdrawal to the main canal was 97%. The discharge measurement was performed at three measuring stations at the head, middle, and tail on the main and secondary canals respectively by using the area-velocity method. Also, the velocity of discharge flow through both canals was examined by using floating material (tennis ball). The causes of malfunctioning structures were investigated through field observation. And also, there is a sedimentation problem in the diversion weir due to the under-sluice gate structure is not constructed at diversion head-work, whereas seepage problems in the main and secondary canals due to the many parts of the canals are unlined. The overall average main and secondary canal's conveyance efficiency was 57% & 59%, and water conveyance loss was 43% and 41% respectively, which is below recommended values. This conveyance efficiency is reduced due to breakage occurring on the main canal, seepage, siltation and vegetation growth within the canal interfere. The maintenance indicators investigation of the scheme was examined. This means that; the value of the effectiveness of infrastructure was 58%, the sustainability of the irrigated area was 71%, the delivery duration ratio was 200%, and the water surface elevation ratio (58% for MC and 62% for SC) respectively. Based on the results of the maintenance and conveyance indicators, Basaka small irrigation scheme requires a high level of maintenance.
Abstract: Hydraulic Performance evaluation of the irrigation system is important to conserve scarce water resources by improving the performance of the existing irrigation structure. However, there was no study in the past performance evaluation of the Basaka scheme, which is used for irrigation purposes. This study was to evaluate the hydraulic performance ...
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Using Mechanical Vibration to Enhance Heat Transfer on an Extended Surface: A Review Study
Furqan Haider Mohammed Ali,
Ehsan Fadhil Abbas,
Iesam Jondi Hasan,
Shahen Mohammed Fakhraldin
Issue:
Volume 8, Issue 3, September 2023
Pages:
162-172
Received:
28 July 2023
Accepted:
15 August 2023
Published:
28 August 2023
Abstract: Given the significance of improving heat transfer in thermal engineering equipment, researchers in this field have developed numerous methods for heat transfer improvement. These methods are classified as active and passive. Several researchers consider the use of forced vibration in improving heat transfer to be one of the most significant topics in the applied field. This is because some thermal equipment has this feature due to its nature. As a result, the current study emphasizes research dealing with mechanical vibration in enhancing heat transfer in free convection conditions. The results of these studies agreed that heat transfer by free convection and vibration contributed to improving the thermal performance of thermal equipment compared to its at-rest condition. These studies' findings indicate an increased heat transfer coefficient as frequency is raised, particularly in forced convection heat transfer. However, the limited vibration amplitude has an impact on heat transfer. In some studies, the fin slope was studied in addition to vibration. These studies showed that fin tilting reduces heat transfer optimization value with fin tendencies that produce vibrations. Furthermore, while the vibration process does enhance heat transfer capacity, it is accompanied by certain drawbacks. These include the generation of noise, which can disturbance to humans, as well as potential damage to mechanical components of the equipment.
Abstract: Given the significance of improving heat transfer in thermal engineering equipment, researchers in this field have developed numerous methods for heat transfer improvement. These methods are classified as active and passive. Several researchers consider the use of forced vibration in improving heat transfer to be one of the most significant topics ...
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Optimization Study of Methyl Ester (Biodiesel) Synthesis from Chicken Tallow Using Polyoxomolybdate Catalyst
Ibrahim Garba Wawata,
Abubakar Umar Birnin Yauri,
Aliyu Muhammed,
Babayemi Wasiu
Issue:
Volume 8, Issue 3, September 2023
Pages:
173-183
Received:
9 August 2023
Accepted:
25 August 2023
Published:
6 September 2023
Abstract: Biodiesel, which consists of fatty acid alkyl esters, is currently accepted as a potential alternative to petro-diesel due to its low carbon footprint and environmental advantages. This study synthesized a polyoxomolybdate catalyst in an organic-aqueous phase at a pH of 2, using Ammonium Molybdate ((NH4)6Mo7O24.4H2O) salt. The catalyst underwent characterization through a UV-visible spectrophotometer method. The physicochemical properties of the chicken tallow were determined using standard methods from AOCS and other established techniques. The transesterification of chicken tallow utilizing polyoxomolybdate was optimized using a three-level, four-factorial Box-Behnken experimental Design with 27 runs of Response Surface Methodology (RSM). Furthermore, the produced biodiesel was characterized using FTIR, while the profiles of fatty acid methyl esters were determined using the Gas chromatography-mass spectrometry (GC-MS) technique. The fuel properties of the biodiesel were analyzed using ASTM methods. The spectroscopic studies of the catalyst unveiled the presence of predominantly (Mo2O22+) and H2MoO4 species. The chicken tallow reveals low acid and free fatty acid values, with a moderate degree of unsaturation (iodine value) and saponification value. The experimental results and surface response plot indicated an optimal biodiesel yield of 96.9% at 60°C for 60 minutes, using an oil-to-methanol ratio of 1: 6 with a catalyst loading of 1.2g. Additionally, the FTIR and GC-MS analyses demonstrate the successful conversion of chicken tallow into methyl ester, exhibiting favorable fuel properties that fall within the acceptable limits set by ASTM. The polyoxomolydate catalyst showcases exceptional activity, good reusability (up to 3 cycle run), and ease of separation from the product mixture.
Abstract: Biodiesel, which consists of fatty acid alkyl esters, is currently accepted as a potential alternative to petro-diesel due to its low carbon footprint and environmental advantages. This study synthesized a polyoxomolybdate catalyst in an organic-aqueous phase at a pH of 2, using Ammonium Molybdate ((NH4)6Mo7O24.4H2O) salt. The catalyst underwent ch...
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