bluuebunny/crossref_metadata_2025_split huggingface dataset:
Railway track monitoring using drones
Authors: El-Sayed M.F. , Riad H.S. , Zohny H.N. , Zahran M.S. 
Published: December 2023

Abstract
In recent times, the use of drones to monitor various types of transportation lines has attracted more attention. Unmanned aerial vehicles (UAVs) have a number of potential benefits over manual methods for inspecting transportation lines due to its permit scalable, quick, and affordable solutions to tasks that would otherwise be unsuitable for individuals who are subject to fatigue and measurement uncertainty. Therefore, the current study investigates the use of drones in image processing, early warning and situation assessment in the transportation sector. Due to their ability to capture aerial images in extremely high resolution at a low cost and while also covering large areas, drones are a very important source of visual data. The main goal of this work is to collect and analyse drone-shot images using MATLAB software in order to locate the line’s fault and take the necessary corrective action to prevent accidents and save lives. The results of the current work concluded that the using of aerial image processing is very effective to increase and maximize the capacities of the transportation lines. Moreover, it gives more safety for the lines. UAV can survey and take pictures of the railway line for a distance of about 8.4 km in one hour, whereas a worker would need a full day to cover the same distance (a worker scans a distance of 7 km per day), so it saved time and effort.
Numerical investigation of model Francis turbine for performance enhancement with geometrical modification
Authors: Kayastha A , Ghimire A , Bijukchhe P L , Neopane H P , Dahlhaug O G 
Published: December 2023

Abstract
Most of the hydropower plants in Nepal are run-of-river type and over 60% of them are operating with Francis turbines. There are huge fluctuations in flow during the dry and wet seasons, which force the power plant owner to operate the turbines at off-design conditions which can induce cavitation and fatigue loads on the turbines. This study focuses on numerical analysis of a model turbine designed for the Jhimruk hydropower plant in Nepal. A geometrical modification is made to the model turbine runner blades by attaching two pairs of vortex generators (VGs) to each blade surface on the pressure side at 0.5% span, at the leading edge. The flow on the blade breaks off and separates from the surface during the off-design conditions so VGs are introduced to mitigate swirls generated at the inlet of the turbine. VGs can help to reattach the flow and improve off-design performance of the turbine. The performance of model turbine is analyzed at different guide vane openings to simulate different operating conditions by keeping the operating head constant and varying the rotational speed of the turbine from 500 to 1500 rpm. Performance curves and hill diagrams of the turbine are generated for each case with and without VGs. The results show that VGs at off-design conditions show a maximum increment in efficiency by 12% and 1 to 5% on average. The power output is also boosted by 1 to 6 kW at off-design conditions. This objective has been achieved when compared to efficiency and power at low-discharge and high-speed regions. In conclusion, VGs are simple but effective tools to enhance the performance of hydraulic turbines as well.
Review on erosion phenomenon, maintenance, and financial calculation of lifetime as an asset for Pelton turbines
Authors: Abregu Jim , Acharya Nirmal , Solemslie Bjørn W. 
Published: December 2023

Abstract
Prevention of greenhouse emissions is the top priority for all countries, which urges them to switch to renewable energy as much as possible. Hydropower is one of the renewables that have high flexibility and at the same time compatibility to be used with any other renewable sources. Moreover, hydropower plants operating in the Himalayas, Andes, and Alps are facing operational challenges due to the high concentration of sediment loads in rivers. Although the arrangement of traditional sediment control mechanisms like dams and sand traps, the erosion tendency of hydro-turbine components operating in this sediment-laden water increases with the increased concentration of sediments. Much past research has been directed towards understanding sediment behaviors, investigation of flow, and effect of concentration, shape, and size, especially with Francis turbines. However, there are very fewer studies regarding sediment erosion and flow behavior in the case of the Pelton turbine. Hence, delving deeper into the flow characteristics, sediment behavior, and performance of the Pelton turbine is important to better understand the flow and sediment pattern of these types of turbines. The paper consists of the evaluation of studies conducted on the flow pattern in the Pelton turbine buckets and its validation with the numerical analysis models using image processing. It is being used in the Waterpower Laboratory at the Norwegian University of Science and Technology, NTNU. This paper also evaluates the scope of investigations about erosion by sediments in Pelton buckets using image analysis and state-of-the-art technology in the hydropower sector. In addition, a review is done about the predictability of erosion based on the measurements of the quantity of sediments that passes through the turbine. This research paper can build a background for quantifying sediment erosion in Pelton turbines with a certain degree of error, which can be utilized as a reference in future studies. The life cycle estimation of a turbine is also analyzed with the consideration of its location and financial return requirements together with the type of maintenance that it may have and the repair that is foreseen, in the case of a non-coated surface.
Numerical Simulation of Erosion in Pelton Spear Valve at Different Openings
Authors: Pandey A , Ghimire A , Bijukchhe P L , Pokharel N , Kapali A , Chitrakar S 
Published: December 2023

Abstract
The spear valve is one of the most eroded hydro-mechanical components of the Pelton turbine operating in sediment-laden conditions. The spear valve is used to regulate or control the flow. In a multi-nozzle system, though having the same design, the spear valves show varying erosion patterns and intensities. The only difference was found to be the openings of the nozzle/spear valve. This demonstrates that there is some sort of connection between the nozzle opening and the erosion of the spear valve. The difference in erosion intensity in different spear valves can be seen on the site but the underlying phenomenon behind the erosion needed to be studied numerically. In this research, erosion patterns were numerically investigated using an open-source CFD tool, OpenFOAM. For this simulation, the sediment particles and their properties were incorporated into the flow using the built-in Lagrangian library of the OpenFOAM. To investigate the erosion in real time, a transient simulation was undertaken for various nozzle openings. This study only focuses on the erosion at the tip of the spear valve neglecting other parts of the nozzle. This study demonstrates that the erosion in the tip of the spear valve increases with the restriction in flow.
Rotational Speed Measurement of a Shaft Using Infrared Sensor with NI Data Acquisition system and LabVIEW
Authors: Sapkota P , Pokharel N , Silwal R , Chitrakar S , Neopane H P , Thapa B 
Published: December 2023

Abstract
Rotational speed measurement is the process of determining the number of rotations completed in a unit time. Generally, it is measured in Hertz, radians per second and rotations per minute (RPM). Rotational speed measurement is very critical parameter in condition monitoring, speed control, and supervision of rotational equipment like generators and turbines. This paper presents an alternate method of measuring the speed of a shaft using one of the cheapest infrared sensors available in Nepalese market. The principle of measurement of speed is on the basis of reflected and absorbed infrared light which is acquired using data acquisition unit of National Instrument. The signal processing has been carried out in a LabVIEW program and speed of shaft has been verified using the other optical sensors.
Numerical study of erosion on labyrinth seals of Francis turbine
Authors: Rijal Mamata , Neopane Hari Prasad , Chitrakar Sailesh , Pandey Arun , Dev Jwala Prasad 
Published: December 2023

Abstract
Sediment erosion is one of the most challenging problems in hydropower plants in Nepal. The sediments like quartz erode the turbine components like runner blades, labyrinth seals and others. This study has focused on the erosion effects in different labyrinth seals of the Francis turbine. Labyrinth seals are non-contact seals used for minimizing unwanted leaks between stationary and rotating parts. The labyrinth consists of two parts: a static seal connected to the turbine covers and a rotating part connected to the runner. The labyrinth gap is small for a new turbine and so the leakage is low. The leakage grows as the gap widens due to erosion in the seals. This causes a reduction in the efficiency of the turbine. Thus, numerical analysis performed on 2-dimensional straight-through (unilateral and bilateral), stepped, and full-length labyrinth seals of Francis turbine have been covered in this research paper. The numerical models were constructed with a structured grid using ICEM. CFD simulation in OpenFOAM was carried out to understand the flow with sediment particles in different labyrinth seals. The volume eroded was evaluated using the Finnie erosion model. The pressure, velocity profile and volume eroded in labyrinth seals were investigated. The study showed stepped labyrinth seal had a maximum volume eroded on both the stator wall and rotor wall compared to other seals. Similarly, the study revealed that the rotating part of the labyrinth seal is more affected by sediment erosion than the stationary part of the seal. This is due to the high accumulation of sediment particles in the rotor wall of the labyrinth seal.
Numerical Investigation of Compatibility of Synthetic Natural Gas with Conventional Liquefied Petroleum Gas Burners
Authors: Pandey B , Ghimire R , Sapkota N , Dev A 
Published: December 2023

Abstract
Nepal is seeking carbon-free alternative fuels due to environmental concerns and economic issues resulting from fossil fuel usage. Carbon-neutral SNG has the potential as an alternative to LPG gas in domestic cooking, but traditional LPG equipment may not be compatible with SNG. Computational Fluid Dynamics (CFD) was used to study the compatibility of traditional LPG equipment with SNG, and it was found that essential optimization is needed to obtain optimal cooking conditions by SNG combustion. Engineering Equation Solver (EES) was used to determine the optimum inlet pressure for varying nozzle sizes. Based on the results of the study, it was determined that the optimal nozzle size for the selected type of burner is 1.15 mm. This particular nozzle size was found to provide better uniformity of flame temperature and complete combustion, resulting in an average temperature of 1700 K at a fuel inlet pressure of 2.75 kPa. This makes it a potentially better option for cooking compared to LPG, as it could potentially provide faster cooking times. The results were verified using the Python CANTERA model. A 40-50% increase in the nozzle orifice size from the traditional LPG nozzle orifice size is suggested for such conversions.
Based on Gradient Algorithm for the Inverse Source Problem of a Class of Time-space Fractional Diffusion Equations
Authors: Qin Xianru , Li Yushan 
Published: December 2023

Abstract
Since entering the 21st century, the establishment of fractional-order diffusion equations in various fields has been of great value and has garnered widespread attention. This study focuses on inverse source term problem for time-space fractional diffusion equation (TSFDE) using given boundary data. First, the identification source problem is transformed into a functional minimization problem utilize the Tikhonov-type regularization method. Then, the sensitivity and the adjoint problem are derived, and the gradient of functional is obtained. The conjugate gradient algorithm is used to solve the minimization problem. Finally, three xamplel with different types of source terms are used to stated the effectiveness and stability, the impact of various parameters on the numerical results is analyzed.
The Discrete Grey Power Model Based on the New Information Priority and its Application
Authors: Yang Baohua , Li Kegang , Zhao Jinshuai 
Published: December 2023

Abstract
How to upgrade the performance and suitability of the forecasting method and reduce the modelling error for nonlinear small sample data series has been one of the most key problems in grey system theoretical exploration. The main work of this study, a discrete grey power model is formulated that can not only simulate the development of exponential and power function systems but can also reflect the interaction between them. The new model not only ensures that the more recent information is given some priority but exhibits a lower simulation error and greater prediction accuracy. The findings indicated that the presented model minimizes the average relative error in theory, with better adaptability than previous models in simulation and prediction. The case study demonstrates that the new model is more appropriate for predicting small sample data than the previous grey power model. This research addresses limitations in existing grey models and expands the grey model system.
Positive Definiteness of the Sample Covariance Matrix of Multi-poisson Distribution
Authors: Miao Jianqun , Wu Jianq 
Published: December 2023

Abstract
Studying the positive definiteness of the covariance matrix of discrete samples helps to determine whether the dimensionality of the samples can be reduced, which is beneficial for optimizing the number of samples and designing optimal plans for sampling surveys. This paper aims to provide a method to determine the variable numbers of the sample subjecting to Poisson distribution. Methods. It is based on the theory of I-linear combination and its properties which are the author’s previous studying results. Results. study shows the covariance matrix of multi-Poisson distribution is positively defined and the probability of the sample covariance matrix of multi-poisson distribution is about 1 when the sample capacity is very large. Conclusion. The dimension size of the sample data matrix of multi-poisson distribution can be reduced when the sample capacity n is no more than the dimension size p.
An Improved Multi-dimensional Uncertainty Quantification Method Based on DNN-DRM
Authors: Zhao Yingge , Wang Lingyue , Li Ying , Jin Ruixia , Yang Zihan 
Published: December 2023

Abstract
Mathematical modeling is a method that uses mathematical methods to solve problems in real life. In the process of modeling, the inherent properties of the parameters and the change of the model design conditions will bring great uncertainty to the simulation results. In this paper, a deep neural network and dimension reduction method (DNN-DRM) is proposed to quantify the impact of parameter uncertainty on simulation results in modeling systems with multi-dimensional uncertainty, and reduce the risk caused by uncertainty. Firstly, the methods for training DNN substitute model and testing the generalization ability of models were investigated. Then the DRM based on DNN was constructed to solve the uncertain parameters in the system. In the experiments, three mathematical models with different types of complexity were modeled. Finally, the performance of the method was evaluated by probability distribution, mean and standard deviation of output values. The results show that compared with Monte Carlo simulation (MCS), the DNN-DRM can efficiently and accurately calculate the multi-dimensional uncertainty problem with a strong interaction, and effectively alleviate the “curse of dimensionality” difficulty, which provides a reference for the analysis of problems encountered in real life.
Predicting Forming Defects in Thin-walled Circular Tubes Made of A286 Based on Deform-3D
Authors: Jiang Yulian , Feng Zhiguo 
Published: December 2023

Abstract
We conduct a study on the thin-wall characteristics of a certain type of A286 thin-walled pipe fittings during the swaging forming process, focusing on the issues of folding and incomplete filling. In order to explore the forming mechanism of defects in thin-wall pipe fittings, the Deform-3D finite element software is utilized for numerical simulations. Through analysis of the forming results, equivalent stress, equivalent strain, material flow lines, and material flow patterns during the swaging forming process, it is found that the occurrence of defects in the thin-wall pipe fittings during the forming process is closely related to the material flow behavior. When the material flows in a positive extrusion manner during the thin-wall feature forming process, the specimen exhibits obvious folding defects. Moreover, there is significant stress concentration occurs in the transition region between the rod and the head.
Implementation of TOD Concept on Gondangdia Station Area and the Influence on Menteng Heritage Area
Authors: Tohjiwa A D , Amartya M H P P 
Published: December 2023

Abstract
The Gondangdia Station area is one of the areas where the TOD concept development has been implemented in Jakarta. This station is located in the Menteng area which is a cultural heritage area. This study aims to explain the application of the TOD concept in the Gondangdia Station area physically and see its impact on the Menteng cultural heritage area. Search data using a field survey method by observing the urban environment along a radius of 1 kilometer from Gondangdia Station. The data analysis is based on the evaluation of 8 aspects of TOD from ITDP and looks at the effect of the implementation of the TOD on the Menteng cultural heritage area. The results showed that of the eight aspects of TOD that were evaluated, most of them were available, but not all aspects met the existing provisions. Aspects that need to be completed and improved are transit facilities, bicycle lanes, and activity zoning integration (mixed land use). The existence of TOD-based development in the Menteng cultural heritage area generally has a positive impact on accessibility and environmental improvement. Unfortunately, the historical buildings there are less integrated with other TOD elements.
Analysis of flooding and nature-based solutions in the improvement of urban drainage system
Authors: Wijayanti Yureana , Julianto Andreas , Cahyono Christian , Juliastuti  , Setyandito Oki 
Published: December 2023

AbstractThis paper studies the drainage system performance of a conventional system with concrete channels and a retention pond. Also, the analysis of runoff reduction by implementing a nature-based solutions (NBSs) technique of rainwater harvesting and recharge well. The case study site is located in an industrial area in West Karawang City, West Java. The analysis was carried out by simulating the flood event using rainfall data from the site for a 10-year return period. The flood simulation was performed using the Storm Water Management Model (SWMM). The model consists of the analysis of flooding events in the drainage system and retention pond and the analysis of flooding prevention scenarios. The result reveals that the cause of the flooding is an extreme rainfall event which leads to the large accumulation of water at one junction point. Moreover, although the capacity of the retention pond is sufficient, the discharge rate is way larger than the infiltration rate, so the overflow occurred and resulted in flooding. The scenario of widening the drainage channel and installing a pump in the retention pond provides a good solution scenario to prevent flooding. The implementation of rainwater harvesting and recharge well could reduce the surface runoff volume of 21%. Further study should be conducted to analyze the combination of conventional and NBSs drainage system performance under the highest daily rainfall of the series.
Clayshale Stabilization Using Liquid Calcium Carbonate to Increase Soil Shear Strength
Authors: Agung P A M , Lutfiyani H , Hasan M F R , Salimah A’isyah 
Published: December 2023

Abstract
Clayshale is a material that often causes various stability and bearing capacity problems in geotechnical engineering structures because it tends to weather and slake relatively quickly. This causes clayshale to be often not used during construction. Therefore, it is necessary to stabilize the clayshale. This study aims to determine the effect of adding variations in the levels of liquid calcium carbonate to the clayshale shear parameters. Physical and mechanical properties were tested on the original remoulded clayshale and samples with additional variations of 1M and 2M liquid CaCO3. Based on laboratory testing, the original clayshale samples had LL values of 37.9%, PL 14.6%, IP 23.3%, Gs 2.617, OMC 13.67%, γdry 1.762 gr/cm3. The addition of CaCO3 has been proven to increase the Gs value and reduce the plasticity index of the clayshale. After the Triaxial UU test, the clayshale sample in remoulded condition has a c value of 0.171 kg/cm2 and φ 8.33°. While the clayshale sample with 2M CaCO3 substitution as much as 80% OMC value which has been cured for three days increased the most optimum c and φ values, respectively 0.289 kg/cm2 and 11.13°. This shows that the addition of liquid CaCO3 can be used as a clayshale stabilization agent because it can increase the value of the shear parameter and improve the clayshale properties.
Artificial Lighting’s Relation to Visitors’ Activity Place in Coffee Shops: An Analysis
Authors: Novrial  , Hidayat H F , Affif A M 
Published: December 2023

Abstract
Artificial lighting is lighting that comes from manufactured light sources such as lamps. To make the room comfortable and function properly, the lighting must be able to accommodate various activities in the space. This study aimed to determine the relationship of artificial lighting to the visitor’s activity in coffee shops. The artificial lighting studied included light intensity, light color temperature, and lighting distribution. The results of the data collected were then analyzed using descriptive analysis methods. The study’s results indicate that artificial lighting affects the visitor’s activity. Areas with higher light intensity, light color within the white spectrum, and a more even light distribution have more activity variety.