Technical Journal

Design and Thermal Analysis of Diesel Engine Piston

Chiranjivi Dahal — 2023-12-31

The piston of an IC engine bears the number of forces before transferring the force to the crankshaft. The main objective of this study to find out the temperature distribution and deformation in diesel engine piston when it is acted upon by gas pressure and high temperature from burning gas. Aluminum alloy has been chosen for the analysis purpose. Suitable data has been assumed to design the geometry of piston. The analysis of the temperature and deformation due to temperature are performed on FEA based software. The boundary conditions include temperature from burning gases and pressure exerted by gas in piston. The results show the crown of piston has the maximum temperature with value of 196°C and maximum deformation of 0.198mm.

Issues and Challenges of Class C Contractors in Pokhara

Hem Prasad Gurung — 2023-12-31

This study entitled “Issues and Challenges of Class C Contractors in Pokhara” was carried out for all Class C Contractors registered in Contractors’ Association of Nepal (CAN) Kaski. This study aims to investigate the issues and challenges faced by Class C contractors in Pokhara. Expert interview were conducted after thoroughly reviewing the literature and reports of the Nepalese construction industry to identify the major problems of Nepalese contractors. The data were collection through questionnaire surveys and interviews. The main objective was to identify the burning issues and challenges of Class C contractors of Pokhara.The findings revealed that most of the construction firms in Pokhara are engaged in different sectors of constructions and few firms are specialized in particular construction work i.e. Road construction and maintenance. These firms meet equipment capacity as per CBA 2055 & CBR 2056 and are financially and technically viable for bidding process as per Qualification Criteria of PPA 2063 & PPR 2064. The results indicated that the major issues and challenges of contractors in Pokhara are competitive pre-qualification process during bidding, low bidding and corruption, hiring qualified human resources, work experience, delay in payment, political intervention, job insecurity, price escalation and inflation, insecurity due to hooliganism in construction site, revenue and taxation, government rules and regulations, contract documents, etc. Based on the findings of the study, it is concluded that the government and concerned authorities should implement flexible and appropriate policies and laws with standard guidelines for prequalification criteria and formulate amendments in standard bidding documents containing clauses under new procurement act. Amendments like bidding capacity of classified contractors, price escalation and inflation, JV prequalification criteria, duty privilege for construction equipment, high rate of registration, renewable fee and vehicle tax, VAT system, present income tax assessment procedure, etc. should be revised under new procurement act. The study can also be useful for benchmarking the status of Class C Contractors in Pokhara.

The Assessment of the Quality of Existing Parks along Phewa Lake, Pokhara, Nepal

Luna Thapa — 2023-12-31

This paper aims to identify the quality criteria to assess the quality of parks and examines the quality of urban parks along Phewa Lake in Lakeside, Pokhara. After a comprehensive study of relevant literature, six criteria are selected for the quality assessment of the urban parks under study; Accessibility, Distinctive Characteristics, Activities, Condition of landscape elements, Condition of utilities and services, and Cleanliness. The criteria are further divided into sub-criteria for the study. Field visits, observation, and key informants’ interviews were conducted to collect data and triangulate results. The findings revealed the existing quality of the urban parks in terms of the selected criteria of assessment. The quality condition of a park differs from one criterion to another and also differs from one park to another. The results from the study will be beneficial in improving the quality of the parks by focusing on the criteria where the park is lagging.

Green and Sustainable Pyrolysis: Conversion of Plastic Solid Waste into Liquid Fuel

Manish Dhakal — 2023-12-31

Excessive use of fossil fuel like gasoline and increasing number of automobiles has led to extensive scientific research in the field of alternative fuel sources. Also due to the vast range of uses of plastics across many industries, Plastic Waste in landfills and global production of plastic increased over time. The conversion of Waste plastic into liquid and gaseous fuels and value-added chemicals by pyrolysis followed by fractional distillation is explained as a practical and sustainable solution for recycling plastics because the calorific value of plastic is almost identical to that of hydrocarbon fuel. This research work is focused on converting high density plastic into liquid fuel by pyrolysis at temperature 200-400℃. The obtained liquid fuel was subjected to distillation at different temperature ranges. The density and viscosity of distilled sample was measured and was found to be close to that of petrol.

Design and Fabrication of a Spiked-Shaft Maize Seed Separato

Prabhat Kiran Bhandari — 2023-12-31

Maize shelling in developing and underdeveloped nations has been and remains a severe problem to its processing as it is tedious and requires more labour hours. This study aims to design and fabricate a motor-powered spike-shaft type Maize Seed Separator (MSS) machine. The design and selection of components like the motor, belt, frame, bearing, and shaft were made based on general design considerations. After the complete fabrication of the MSS machine, it was tested to find its shelling capacity and efficiency. The shelling capacity was found to be 220 kg/hr, which is 80 times faster than manual shelling and the maximum shelling efficiency was found to be 97 % at the feeding rate of 4 kg at a time. The machine consumes 1.28 kW of electricity, which, when operated for one hour,would cost about Rs. 14 per hour.

Transient Analysis of 9-Bus System using ETAP

Rahul Kumar Jha — 2023-12-31

This research paper presents a transient analysis of a 9-bus power system using ETAP software. The simulation results obtained from ETAP are analyzed in terms of voltage and current waveforms, fault current magnitudes. However, the system experiences voltage and current fluctuations during fault conditions, which can lead to instability if not properly addressed.

Assessment on Quality of Coarse and Fine Aggregate of Riverbed Quarry as Construction Material Used in Kaski District of Nepal

Ramesh Banstola — 2023-12-31

Quality of the composite material and ingredient of the materials in composite material plays a vital role in the sustainable infrastructure development. The quality of concrete is conformance to technical requirements as per specification or fitness for uses having minimum acceptance level to use the products. Among the various properties of fine and coarse aggregate of sampled quarry, only physical and mechanical properties of coarse and fine aggregates were tested in the laboratory, analyzed and compared with IS code and Standard Specification for Road and Bridges Works-2073 (with second amendment-2078) of Department of Roads (DoR), Nepal. Results revealed that physical properties of all the sampled quarry on gradation of coarse and fine aggregate lies within the IS code provision, whereas only source of Rato Pairo Mishi Tunda Shanik Ghat and Gahara Ghat comply the specifications defined by Standard Specification for Road and Bridge Works -2073 (with second amendment-2078), The specific gravity and water absorption of all the sampled quarry satisfied as per the Standard Specifications for Road and Bridge Works-2073 (with second amendment-2078). The mechanical properties such as crushing value of coarse aggregate of all sampled quarry satisfied standard value, impact value of sampled aggregate from Babya Tara, Mahari Ghat and Chuina Pahara Ghat dosen't comply within standard value, and abrasion value of sampled aggregate from Mahari Ghat and Chuina Pahara Pasupati Ghumari Ghat does not meet the standards as defined by the Standard Specifications for Road and Bridge Works-2073 (with second amendment-2078). The properties of fine and coarse aggregate have significant influence on performance, quality and serviceability of concrete mix & finally influence durability of the engineering structures.

Study of Space Layout of Museum; A Case of International Mountain Museum at Pokhara, Nepal

Samikshya Kandel — 2023-12-31

Currently, the museum is one of the learning and pass time activities space for the public. A good layout of a museum can bring a wonderful visiting experience to the visitors. Overall, museums play an important role in preserving a town's cultural heritage, providing educational opportunities, attracting tourism, and promoting community engagement. Effective space distribution in a museum is critical for creating an engaging and informative experience for visitors. By carefully considering the needs and interests of different types of visitors, museums can create spaces that are both functional and aesthetically pleasing. But there are very few designed museums in Pokhara, one of the growing cities of Nepal. Also, it is one of the tourist attracting places in Nepal. This paper explains the spatial layout of one of the designed museums of Pokhara. For this purpose, a well-known International Mountain Museum is taken as a case area by using observation and questionnaire survey methods. This museum displays a wide range of exhibits related to the Himalayan mountains, mountaineering, and the culture of the people who call the region home. In addition to the mountaineering exhibits, the museum also features displays of the history, culture, geology, flora, and fauna of the Himalayas. Overall, space distribution in a museum is designed to facilitate the flow of visitors through the space, while also highlighting the key messages and themes of the exhibits.

Revolutionizing Natural Language Processing with GPT-based Chatbots: A Review

Smita Adhikari — 2023-12-31

OpenAI introduced a language model called GPT (Generative Pre-trained Transformer model. The algorithm learns to predict the following word in a phrase based on the context of the preceding words after being trained on a large text dataset. GPT employs a transformer architecture, a class of neural networks that have been demonstrated to perform exceptionally well on tasks involving natural language understanding. Pre-training was one of the fundamental advances of GPT, allowing the model to learn a variety of broad language representations from a vast amount of text input before being fine-tuned on tasks. Through this pre-training phase, the model can recognize pertinent information from the data that could be used for various upcoming tasks, such as information extraction, language translation, summarization, etc. Since its initial release, GPT has undergone several iterations since its initial release, including GPT-1, GPT-2, and GPT-3. GPT-1 was the model's first version, followed by GPT-2 and GPT-3. With a significantly larger model performance and a broader dataset, GPT-2, launched in 2019, performed better on various tasks. GPT-3,the most recent version of the model, was released in 2020. With 175 billion parameters, it is the largest model to date and could generalize across various domains. The GPT language model has a variation called ChatGPT that was created exclusively for conversational AI challenges. It is pre-trained on conversational data and tailored to tasks such as generating conversational responses and comprehending conversations. In general, ChatGPT is a powerful conversational AI technology that has demonstrated promising outcomes in various use cases and industries, including customer service, e-commerce, and entertainment.

Predicting Chronic Kidney Disease using ML algorithms and LIME

Tara Bahadur Thapa — 2023-12-31

Numerous researchers have implemented machine learning (ML), and deep learning (DL) to predict chronic kidney diseases (CKD). But these studies have succeeded in early diagnosis, they lack transparency. Such ambiguity has raised red flags in adopting AI in the critical domain of healthcare and medical analyses. This paper aims at interpreting the outcome of predictive models by proposing an explainable AI (XAI) interface using local interpretable model-agnostic explanation (LIME). The intended model aims to hold the system accountable for its projections, which will assist efficient decision-making in the field of clinical research and therapeutic practice.

Fracture Mechanics Induced by Drilling and Blasting in Underground Openings: Prevailing Practices and Studies

Tek Bahadur Katuwal — 2023-12-31

This article presents the prevailing practices and literature review on the study of fracture mechanics of rock mass, during the construction of underground openings, by drill and blast method (DBM). The paper makes an introductory discussion on basic fracture and failure mechanics on the rock, followed by a review due to the blast-induced failure mechanism. The damage zone in drill and blast openings is discussed which is followed by the conclusions of the literature. DBM is a widely acceptable and broadly applicable approach in the underground construction method. The blasting damaged zones are classified as the borehole expansion zone, crushed zone, nonlinear fracture zone, and radial crack propagation zone. Blasting activities create stress waves in construction work, which fundamentally influence the fracture and failure mechanics of rock with pre-existing discontinuities, in-situ stress, and groundwater conditions. On the other hand, the cumulative action of subsequent explosion gas and stress waves defines the final damage limit and crack pattern map. Thus, it is of utmost importance to investigate the blast-induced fracture and failure mechanism to mitigate the instability in the underground openings.

Hybrid Energy Storage with PV for Islanded DC Microgrid

Yam Krishna Poudel — 2023-12-31

Cogitating the present national as well as global context, renewable energy sources are becoming increasingly popular as a source of electricity in places, where connecting to the utility grid is either impossible or excessively costly. Several trends that have emerged as electrical distribution technology in the twenty-first century will change the requirements for energy transmission. Green power generating methods are receiving more attention due to the world's deteriorating environmental conditions, rowing prices, the limited nature of fossil fuels, and rising energy demand. The increasing depletion of fossil fuels and the escalating need for energy has made renewable energy sources a global topic of discussion. The incredible advancement of renewable energy has allowed us to address environmental problems. However, the production from these sources could be more predictable which requires an appropriate energy storage system. The main aim of this research paper is to study the hybrid energy storage with solar photovoltaic for islanded DC microgrid. This research study simulates, analyzes, and presents an islanded mode DC microgrid with solar PV, battery, and supercapacitor through the use of MATLAB Simulink. The MPPT (Maximum Power Point Tracking) system uses a twin-stage DC converter. The regulated Battery Energy Storage System (BESS), coupled through a bidirectional converter, helps to maintain a steady dc bus voltage. The transient and steady-state characteristics of the storage systems are examined. This study demonstrates how quickly hybrid energy storage can adapt to sudden changes in the load.