Improper Installation Research Articles

Pelton turbine needle eccentricity leading to asymmetric hydro-abrasive erosion

Abstract Hydropower generation of turbines located near geologically young mountain ranges like the Himalayas is challenged by incoming sediment particles. Pelton turbines installed at high heads are significantly affected by hydro-abrasive erosion due to high flow and erosion velocities. The injector of the Pelton turbine is one of the major components of the Pelton turbine affected by hydro-abrasive erosion. Improper installation or manufacturing defect leads to needle eccentricity causing an asymmetric erosion pattern of the injector, thereby reducing jet quality. Here, the effect of needle eccentricity on hydro-abrasive erosion of the injector is numerically investigated by tracking the sediment particles using the Discrete Phase Model (DPM). The intensity and asymmetricity in the erosion of the needle increases with an increase in needle eccentricity. Similar behaviour in the erosion of the needle is observed in reducing the nozzle opening of the eccentrically displaced needle. For a perfectly aligned needle, the average erosion rate in both the upper and lower half region of the needle was identical. However, with 8% of needle eccentricity, the average erosion rate in the upper half region of the needle i.e., towards the displaced side was 89% more compared with the lower half region of the needle. The study emphasises the necessity of inspecting the needle alignment, particularly post-maintenance to mitigate the detrimental effects of hydro-abrasive erosion on Pelton turbine performance.

Power Loss Minimization and Voltage Profile Improvement on Nigeria Distribution Network Using Whale Optimization Algorithm

The power grid has significant power losses, unstable voltage, and large voltage drops during high demand due to its high resistance. One way to reduce power loss is by strategically placing and sizing Distributed Generation (DG) within the distribution network. However, improper installation of DG can increase power loss. To address this issue, various optimization techniques have been used, but finding the best solution and dealing with complex issues has been challenging. It is important to make efforts to optimally place and size DG in the distribution network to minimize power loss. To this end, a research study aimed to minimize power loss and improve the voltage profile on the DG network using the Whale Optimization Algorithm (WOA) was done. Objective functions were formulated and integrated into WOA, and power flow analysis on the standard IEEE 33-bus and 33-bus Ilorin industrial distribution feeder with and without DG was conducted using the forward and backward sweep distribution load flow algorithm. The optimal size and location of DG for power network loss reduction using sensitivity analysis (SA) and the whale optimization algorithm were determined. The results of the power flow analysis indicated that the total active losses and reactive power losses were reduced to varying extents with the integration of DG using both SA and WOA. The validation results showed that WOA is more efficient and provides high-quality solutions in terms of system loss reduction and best placement for DG in power systems compared to the application of SA. Additionally, WOA was found to offer accurate and high-quality solutions for power loss reduction compared to other existing techniques such as Loss Sensitivity Analysis (LSA), Grey Wolf Optimizer (GWO), Adaptive Shuffled Frogs Leaping Algorithm (ASFLA), and One Rank Cuckoo Search Algorithm (ORCSA). Keywords: Optimization, Distributed Generation (DG), Whale Optimization Algorithm (WOA), Sensitivity Analysis (SA)

Stakeholder perceptions, challenges, and sustainable solutions for achieving safely managed sanitation in Kazakhstan: a case study from a cold region

ABSTRACT In this paper, we present survey results from 30 sanitation stakeholders across the public and private sectors, professional associations, non-governmental organisations (NGOs), and households in the two coldest cities of Kazakhstan. The objectives were to identify the perceived sanitation challenges, document innovative, and traditional solutions employed by the stakeholders to manage sanitation challenges during the cold season, and to propose initiatives and policy interventions to alleviate pressing sanitation issues. Commonly encountered problems included improper installation of septic tanks (e.g. above the frost line) by non-professionals and the difficulty of households to access latrines during heavy snowfall events. Ninety-three percent of respondents expressed that foul odours and sewage overflows were their primary concerns, with only 7% reporting health impacts as a primary concern. There were significant differences in the viewpoints of the respondents regarding the extent of sanitation infrastructure maintenance or upgrades needed in the two cities, suggesting regional differences across the country rather than a uniform national situation. In the context of Kazakhstan, local NGOs were identified as playing a key role in engaging with households to co-devise affordable and sustainable sanitation solutions that are suitable for cold regions, which can then be communicated to other sanitation stakeholders, including the public sector.

Reliability and criticality analysis of a large-scale solar photovoltaic system using fuzzy-fault tree analysis approach

Over time, solar Photovoltaic (PV) systems experience a decline in performance and reliability due to various environmental factors. Fault Tree Analysis (FTA) can be used to assess the reliability of these systems and identify faults and failure modes that can significantly impact the entire PV system’s performance. However, in practice, obtaining accurate failure probability values for the components of a solar PV system is challenging since systems operate in an ever-changing environment, resulting in a scarcity of data for statistical estimation. This paper proposes a fuzzy theory-based FTA approach to obtain the failure probabilities of the faults more accurately. The Fuzzy-FTA methodology converts experts’ subjective opinions expressed in linguistic terms into a Failure Possibility Score (FPS), which is then converted into a failure probability value. The results of the proposed approach are compared to those obtained through the conventional FTA to assess its effectiveness, applicability, feasibility, and efficiency. Soiling, dust accumulation, inadequate system maintenance, bad system configuration, bird dropping, delamination, improper installation, shading, grounding, and discoloration are the most critical faults and impact on the performance and reliability of solar PV systems.

Simulation Study on Mechanical Vibration Characteristics of GIS Bus Misalignment

Abstract Gas-insulated switchgear (GIS) has been widely used in power grid systems. The busbar is a crucial element within a GIS system, responsible for facilitating electrical connections between different GIS components. Any defects during manufacturing or improper installation procedures can lead to busbar misalignment, resulting in abnormal vibrations within the GIS. This study focuses on analyzing the mechanical vibration characteristics of GIS bus misalignment using a simulation model based on the finite element method for a 252kV GIS. When the busbar is misaligned and the conductor experiences an unbalanced force, it undergoes Coulomb forces at double the voltage frequency. Under normal or misaligned conditions, the conductor exhibits forced vibrations at the power frequency of 100Hz. However, when misalignment occurs, there is a coupling effect between electrodynamics and vibrations, causing the shell to display integer frequency vibration components.

Designing an artificial intelligence-based model for electric motor fault diagnosis to support maintenance decision-making

Motors play a crucial role in production systems. However, not everything always goes smoothly, and motor failures are one of the common challenges in the production process. Misalignment of the drive shaft is a frequent motor fault caused by improper installation or damage to machine components. This study proposes the design of a monitoring and fault diagnosis model for DC motors, which includes: (i) a PID controller for motor speed control; (ii) a vibration signal acquisition unit; and (iii) a motor monitoring unit via Blynk and signal processing for fault diagnosis. In the model, motor faults are classified using a convolutional neural network (CNN) based on analog signals that have been transformed to the frequency domain and denoised. Experimental results demonstrate that classification using the convolutional neural network is highly accurate and stable.

Optimizing Maintenance Strategies for Public Fire Doors in Apartment Buildings: Study on Deterioration Patterns and Replacement Timing

This study aimed to identify factors contributing to the performance degradation of aging fire doors and determine their appropriate replacement time by analyzing the probability of operation of fire doors using building statistics and expert surveys. Aged fire doors with degraded performance should be repaired or replaced quickly; however, there is no clear standard for fire door repair or replacement. Therefore, we analyzed the operation probability of fire doors and conducted expert surveys to determine the proper replacement timing of fire doors and identify the performance degradation factors. The fire door operation probability survey results showed that fire doors operating for those more than 15 years had more than 20% probability of operation failure, and the main causes of operation failure improper installation, insufficient management, or poor performance. The expert survey results indicated that the optimal replacement period for fire doors is 10 to 15 years. The primary factors contributing to performance deterioration were identified as twisting and corrosion (27%), dents (24%), and damage (20%).

Sistem Monitoring Beban Tiga Fasa pada Gardu Distribusi berbasis Internet of Things

To achieve optimal results in distributing electrical loads, maintaining load balance among phases in a three phase installation system is essential, as any imbalance can lead to electrical power losses. One of the factors contributing to load imbalances is the improper installation of electrical equipment across the phases, deviating from the existing installation design. This research aims to develop a system, known as the Load Monitoring System, capable of storing and providing information about the load conditions installed on a three-phase transformer loading system. This system aims to facilitate the process of adding customers, dividing the load on each phase, avoiding load imbalances, and serving as a reference for routine maintenance of distribution substations annually. The methodology employed in this research is a quantitative method based on testing Internet of Things (IoT) monitoring system tools. The results show that the system effectively monitors load current and voltage at the distribution substation. Additionally, the device enables remote monitoring with the Transmitter capable of sending data to the Receiver from distances ranging from 50 m to 100 m and with the TX Max position in dense environmental conditions and full of obstacles such as buildings and trees or in rural areas with limited internet connectivity.

Simulation analysis and prevention strategies for fatigue fracture of the swivel shaft in concrete pump trucks

During the pumping operation of concrete pump trucks, the swivel shaft primarily withstands a series of complex loads such as bidirectional bending moments and torque (stemming from the self-weight of the boom in the amplitude plane, the self-weight of the concrete; wind load and rotational inertia force in the rotation plane; torque from the delivery pipe and the concrete inside), as well as lateral wind load on the concrete and the impact vibration caused by the flow of concrete. These factors can easily lead to fractures due to the loads exceeding the material load limit of the swivel shaft. This study targets the swivel shaft fracture accidents during the construction process of concrete pump trucks, hypothesizing that the accidents occur due to improper installation angles of the swivel shaft (angle between the oil channel hole and the cylinder axis). Firstly, numerical simulation of the onsite conditions is conducted and compared with the results observed from the actual accidents. Secondly, by fixing the onsite conditions (keeping the boom posture unchanged), a 360° rotational simulation calculation of the fractured swivel shaft is performed to identify the relationship between high stress intervals and the swivel shaft rotation angle and the angle between the second variable oil cylinder axis. Finally, a full-condition calculation is conducted for the boom and the swivel shaft. The results indicate that the high stress area of the swivel shaft does not change with the swivel shaft rotation angle (when the boom is fixed) but is related to the position of the second variable oil cylinder axis and is symmetrically distributed around it. Therefore, adjusting the swivel shaft rotation angle to avoid the high stress area near the symmetry axis of the second variable oil cylinder can prevent the fracture accidents of the swivel shaft.

Enhanced complex wire fault diagnosis via integration of time domain reflectometry and particle swarm optimization with least square support vector machine

AbstractUrban power systems rely on intricate wire networks, known as the power grid, which form the essential electric infrastructure in cities. While these networks transmit electricity from power plants to consumers, they are vulnerable to faults caused by manufacturing errors and improper installation, posing risks to system integrity. Thus, accurate identification and assessment of these faults are crucial to prevent damage and maintain system reliability. The objective of this research is to present an innovative and efficient methodology for diagnosing complex wire networks through the application of time domain reflectometry (TDR) combined with the particle swarm optimization (PSO) and least squares support vector machine (LSSVM) algorithm. This research addresses the imperative need to accurately locate and assess breakage faults within wire networks, emphasizing their role in both power transmission and communication infrastructure. To model the TDR answer of a specific complex wire network, a forward model is established utilizing resistance, inductance, capacitance and conductance (RLCG) parameters and the finite difference time domain (FDTD) method. Subsequently, the PSO‐LSSVM approach is used to solve the inverse problem of localizing faults in complex wire networks. The experimental results validate the practicality of this approach in real‐world systems.

A new optimal PV installation angle model in high-latitude cold regions based on historical weather big data

PV technologies are regarded as one of the most promising renewable options for the transition towards Net Zero. Despite the rapid development of PV systems in recent years, achieving the necessary goals requires more than a threefold increase in annual capacity deployment by 2030. However, current PV systems often fall short of optimal performance due to improper installation angles. In high-latitude cold regions, the actual PV generation capacity is frequently overestimated due to the omission of snow conditions. This study introduces a novel model designed for high-latitude regions to predict local optimal PV installation angle that maximizes PV power generation, utilizing historical weather big data, including snowfall and melting effects. A case study is presented within a Swedish context to demonstrate the implementation of these methods. The results highlight the crucial role snow conditions play in determining PV performance, resulting in an average reduction of 14.7% in annual PV power generation. Optimal installation angle could yield approximately a 4.8% improvement compared to common installation angles. The study also explores the application of snow removal agents, which could potentially increase PV generation by 0.1–2.3%. Additionally, the new PV installation angle successfully captures the impact of the local weather changes on PV power generation, potentially serving as a bridge between climate change adaptation and future PV power generation endeavors.

Kajian Kes: Kebocoran Antara Tingkat di Bangunan Kediaman Bertingkat Malaysia

Building defects are a common issue in the construction industry. Defects of high-rise buildings, such as cracks and leaks, are often caused by poor workmanship, and insufficient and low-quality building materials. Other contributing factors to building defects are inadequate cooperation during construction, poor design and improper installation. Inter-floor leakage is a widespread matter in new homes, leaks are detected late and repeated leaks occur even after repairs have been carried out. Inter-floor leakage often occurs in new homes. Leaks are detected late and repeated ones occur even after repairs are carried out. This study aims to diagnose buildings with inter-floor leakage problems by using several diagnostic tools and techniques like visual, destructive and non-destructive tests. Experts use testing equipment to determine moisture and appropriate maintenance or repair. A case study is carried out on a residential unit with a leak in the ceiling due to a crack on the rooftop. The findings of the study can provide knowledge about building diagnosis to property owners and property managers, identifying the cause of leaks and enabling early detection of building defects and suggested repairs to prevent similar leaks from occurring. By utilizing diagnostic tools and techniques, owners and property managers can detect problems early, minimizing damage and expenses in the long run. Based on the study, existing cracks can be converted into expansion joints, white paint can be used on the walls to control heat, installed thermal insulation to control solar energy stress and waterproof membrane can be applied to prevent moisture penetration.

Analysis and Verification of Airborne Instrument Electromagnetic Emission Test

Electromagnetic compatibility is an important factor affecting aircraft performance and safety. With the increase in the number and type of airborne electronic equipment, the requirements for electromagnetic compatibility (EMC) of airborne equipment are increasingly high [1]. Taking airborne equipment as an example, this paper introduces in detail the problem locating method and rectification method of GJB151A standard CE102 and RE102 test exceeding the standard. It analyzes and summarizes the improper design and installation of EMI filters leading to tests exceeding the standard and gives the interference suppression method. Finally, the correctness of the method is verified by the EMC test.

Calibration of Waveplate Retardance Fluctuation Due to Field-of-View Effect in Mueller Matrix Ellipsometer

Leveraging their unique phase modulation characteristics, birefringent waveplates have been widely used in various optical systems. With the development of material science and manufacturing techniques, the polarization properties of waveplates have become increasingly complex and diverse. Among these properties, the field-of-view effect of the waveplate caused due to manufacturing defects or improper installation procedures is extremely difficult to calibrate and seriously affects the precision and accuracy of the relevant optical systems. In this paper, a calibration method that can compensate for the field-of-view effect of waveplates installed in the instrument is proposed. Moreover, to approve the fidelity of the proposed calibration method, a series of film thickness measurement experiments are carried out. The results show that under different installation conditions of the waveplates, the precision and accuracy of the film thickness measured with the proposed method significantly improved. This method can be expected to reduce the assembly difficulty of such optical systems, while also improving their accuracy and stability.

Experiences in assessment, replacement and repair of external tendons

AbstractThe paper presents experiences with damages that occurred when using external tendons. Reason for these damages could be both technical deficiencies of a tendon system (system = components, design, corrosion protection, installation, stressing etc.) or simply human mistakes. Damages often could occur at deviators and anchorages, since forces are transferred to the structure there and the tendon is loaded in transverse direction. Damages will be presented, explained (why it is a damage), which measure had been taken and of course also advice for the future (lessons learned). The damages occurred on site or during testing of external tendon systems. Hence, the paper shall help the reader/attendant to understand sensitivity of external tendons. Furthermore, to these damages experiences with replacement (mainly cutting of the old tendon) of external tendons with flexible filler mass are shared. “Experience” focusses mainly on the de‐installation, re‐installation, grouting and stressing process. Topics that will be covered are:‐ Improper design and/or installation of deviators and subsequent damages to the tendon sheath‐ Torsional strand failure due to improper deviation at stressing anchor‐ Limitations of the tendon path‐ Deficient encapsulation of the prestressing steel‐ Tendon force measurement options

LoRaWAN-based Petroleum Pipeline Leakage Detection System Using Pressure Profile under a Pump Proximity Effect Condition

Leakages in pipeline is an important problem that can occur at any stage of the pipeline lifespan due to ageing, improper installation, or human related factors like bunkering or vandalization. Several invasive and non-invasive techniques are being used which have proven to be successful. However, this study focuses on leakage in an area of the pipeline network that is most often overlooked. This area is within the first 100 meters of the pipeline network to the excitation pump and is often prone to leakages due to high pressure. This study shows that even at no leak conditions pressure profile of a short pipeline in a closed loop configuration can vary by as much 59.93 percent. The study also examined the impact of single leak, double leaks, and triple leaks on the pipeline network with pressure loss compared to the no leak condition ranging from about 10 percent to as high as 60 percent.

Skill Enhancement Through Electronics Installation and Maintenance Training For Forum Jamaah Mushola Al-Hidayah Members

At present, electronic equipment is one of the most important means for the smooth implementation of worship. One of them is a sound system, which is very commonly used during events such as recitations, sermons, and other religious activities. Over time, the influence of environmental factors, usage age, poor installation, and poor maintenance can cause the quality of electronic devices to decrease and even the components to deteriorate quickly. This is generally due to improper installation, poor operation, or poor maintenance. This service is planned to partner with the Jamaah Forum and Takmir Musala Al Hidayah in Kragilan Hamlet, Sidoluhur, Godean, where there is a problem with the lack of an optimal indoor sound system in the prayer room. The solutions offered to overcome these problems are development, installation, and operational training, as well as maintenance of indoor prayer sound systems and procurement of portable sound systems. The output targets of this program are publications in scientific forums and mass media, videos of community service activities, and the transfer of technology applications to partners. In order for the service objectives to be achieved, the service team uses several stages, namely the initial stage in the form of analyzing the needs of partners by discussing with them, preparing service proposals, the program implementation stage, making publication outputs and final reports, and the evaluation stage of service activities. All of the series of service activities have been carried out according to plan and are running well. Members of the Al Hidayah Jamaah forum participated in the activity, which was training for electronics installation and maintenance. At the end of the activity, a partner satisfaction survey was conducted with satisfactory results.

AFFORDABILITY AND EFFECTIVENESS OF SOLAR PHOTOVOLTAIC SYSTEM’S AS A PANACEA FOR CLIMATE CHANGE MITIGATION AND SUSTAINABLE DEVELOPMENT IN KANO METROPOLIS

The study assessed affordability and effectiveness of solar photovoltaic (PV) energy technologies for electricity generation in Kano Metropolis. Three local government areas were selected purposively namely Tarauni, Nassarawa and Ungogo. Household and Small-Scale Business users of solar PV energy and technicians were selected using snowball sampling, while marketers of the PV facilities were selected purposively. Data was analysed using SPSS software version 23 by IBM. The findings revealed that most of the users of solar PV systems considered the prices that was mostly within the range of $487-$973 for households and $292-$487 for small-scale businesses as affordable. Almost all users adjudged their systems as being efficient, durable and enhanced their profit in the investments. A significant number of users, technicians and sellers of the facilities were optimistic that there is widespread use of PV system consequently reduce the use of generator sets and therefore the greenhouse gases emitted by generator will also be reduce. However, high initial investment cost, improper installation, lack of awareness, sub-standard products, lack of government support were the major factors militating against the utilization of the solar PV energy around Kano Metropolis. Governments, International NGOs and Banks should provide low interest loans and grants to solar products producers, importers and users in the country. Subsidy and tax incentives to solar equipment producers, importers and users should be provided.

ESCALATOR STEP DISPLACEMENT’S ACCIDENT: FORENSIC ENGINEERING APPROACH

In Malaysia, escalator accidents caused injuries or fatalities. As a result, a forensic engineering technique was employed to look into the real causes of an escalator malfunction. There was escalator that occurred in 2016, KL Sentral. The escalator accident in 2016. The escalator step displacement is the clearance of a step along the vertical and lateral axes. According to BS EN 115-2017, a step's clearance shall be measured. Step alignment of the escalator steps pass through the comb will be affected by step displacement that is outside of the permitted range, either the lateral or vertical direction that led to collision. The alignment of the escalator steps that moving through the comb will be hampered by step displacement that is more than the standard and it may result in a collision between the two parts on either the upper landing platform or lower landing platform. The impact from the collision of steps and combs may also injured escalator passengers. Hence, the clearance of the step in the vertical and lateral direction at any time. It is crucial to inspect and measure the step displacement parameter for both lateral and vertical step displacement. Improper installation of the step axle slot component on the step shaft; lateral step displacement is caused by clearance between a bush and stopper ring component, while vertical step displacement is caused by clearance between an axle slot and bush component. Prior, installation of those steps must be done carefully to avoid any clearance to prevent step displacement’s accident occurred.

Stochastic Performance of Journal Bearing With Two-Layered Porous Bush—A Machine Learning Approach

Abstract This investigation presents the deterministic and stochastic responses of the journal bearing with a two-layered porous bush. Pressure equations in the porous layers and modified Reynolds equations in the clearance region are governed by the finite difference method (FDM). Stochastic analysis based on Monte Carlo simulation (MCS) is used to investigate the effect of random variation in input parameters caused by uncertain operating conditions, improper installations, and manufacturing imperfections. In order to enhance computational efficiency, this probabilistic study is conducted in conjunction with the machine learning (ML) model based on the support vector machine (SVM) algorithm. The uncertainty in the bearing responses is presented in the form of the probability density function (PDF), considering both the independent and combined effect of the stochastically varied input parameters. Graphical illustration of the data-driven sensitivity represents the relative significance of each input parameter affecting the steady-state responses of the journal bearing with two-layered porous bush. The findings of the present study reveal that the stochastic variations in the input parameters have a profound influence on the operational characteristics of the porous bearing. The outcome of the present study will be helpful in deciding the operational regime of the porous bearing under the practically relevant stochastic environment.