Journal of Engineering and Sustainable Development (JEASD)

Piano key weirs (PKWs) are a new type of labyrinth weirs. They have a longer crest length within a limited width and, unlike linear weirs, ultimately have a higher discharge coefficient. The higher energy loss in PKWs can reduce scour. Therefore, this study used flow splitters on the weir crest and two C-type PKWs with heights of 0.18 m and 0.20 m. The splitters had rectangular and circular cross-sections. They were arranged in three configurations: two-by-two, four-by-four, and six-by-six in each cycle. The results showed that the presence of a flow splitter increases energy loss. Additionally, as the number of splitters increases, energy loss increases, and the discharge coefficient decreases. Adding six rectangular flow splitters to the weir per cycle resulted in an average increase in energy loss of approximately 10.40% and a decrease in the discharge coefficient of 18.60%. On average, rectangular flow splitters had 1.24% higher energy loss than circular ones. The energy loss in weirs with rectangular and circular flow splitters increased by about 6.89% and 5.72%, respectively, compared to those without flow splitters. A 10% increase in weir height led to a decrease in both the discharge coefficient (by about 9.20%) and the energy loss (by about 1.68%).

Sluice gates control water levels and discharge them into small irrigation canals. This study examined a modified stilling basin incorporating submerged baffle piers downstream. The study analyzed hydraulic-jump characteristics, energy-dissipation efficiency, velocity distribution patterns, water-level fluctuations, and bed configurations resulting from flow downstream of the sluice gate. The experimental program comprised ninety runs using ten stilling basin models. These models involve various stilling basins with different baffle pier heights and angles, tested under a range of flow conditions. A smooth apron without baffle piers served as the reference case for comparison. Results showed that baffle piers with a height of 12 cm and a 45° angle oriented against the flow optimized stilling basin performance, improving flow characteristics and minimizing bed configuration. This optimal design decreased dimensionless jump length by 45-47%, increased energy dissipation efficiency by 46-60%, and reduced maximum velocity by 33% compared to the smooth apron across the tested Froude number range. Based on these results, a multiple regression analysis was conducted to develop an empirical equation to predict energy dissipation in the modified stilling basins. These findings provide practical design guidelines for optimizing the performance of stilling basins in small irrigation canal systems.

Despite high solar irradiance in southern Peru, the adoption of photovoltaic technology in rural areas remains limited. This study examines the application of an isolated solar photovoltaic system for the ventilation of a livestock farm in southern Peru. First, the analysis parameters were identified, including geographical location, local solar irradiance, and the ventilation equipment's operating time and energy requirements. A technical–economic analysis was conducted to size the photovoltaic system and assess its feasibility. As a result, the characteristics and specifications of the system components were defined. Additionally, three economic indicators were evaluated: net present value (NPV), levelized cost of energy (LCOE), and payback period. Over five years of operation, the proposed photovoltaic system shows potential for implementation, yielding favorable economic results, including a positive NPV, a moderately competitive LCOE, and a payback period of 3.8 years. The system also avoids approximately 0.165 metric tons of CO₂ emissions per year, demonstrating the environmental viability of using renewable energy for ventilation systems.

This paper presents a small-sized multilayer ultra-wideband (UWB) patch antenna for satellite communication applications in the X band, Ku band, and K band. The antenna consists of two stacked rectangular patches on the ground plane driven by H-shaped slots with miniaturized dimensions of 40 × 40 × 5.51 mm3. The multilayer structure utilizes RT/Duroid®5880 and FR4 substrates, and simulation results show that the operational bandwidth is 15 GHz (8-23 GHz) with a reflection coefficient less than -10 dB. The proposed design exhibits stable omnidirectional radiation patterns, a peak gain of 8.3 dB, and an excellent VSWR across the entire operating band. The comparison of the proposed antenna against existing literature shows that the proposed antenna has a lot of benefits, as it achieves size reduction while maintaining broader bandwidth and higher gain than comparable designs. This antenna has a compact structure, coupled with high impedance matching and radiation properties, which makes this antenna convenient for the current generation of satellite communication systems that need miniaturized broadband components.

The primary objective of this work is to develop and evaluate a computational model to predict the fluid-flow and heat-transfer properties of a reverse-flow corrugated solar air heater collector, with or without a thermal storage unit. ANSYS 19.0 is used for many applications. This study also included an analysis of digital systems and their application to solving the continuity, momentum, and energy equations. These equations were solved numerically using the finite volume method. In this work, the thermal performance of a flat-plate solar collector with fixed dimensions (length = 1.8 m, width = 0.7 m, channel height = 0.07 m) was evaluated, using air as the working fluid. Temperature differences were measured and plotted against air mass flow rates. The results showed temperature differences across air mass flow rates (0.03-0.06 kg/s) at a solar irradiance of 1000 W/m². For each increase in air mass flow rate, a corresponding decrease in the air temperature difference was observed, ranging from 26.9 °C to 14 °C for mass flow rates of 0.03 and 0.06 kg/s, respectively. This was based on numerical analysis of the solar collector; it has been shown that the thermal efficiency increases with the air mass flow rate.

The prosthetic socket is the primary component of a lower-limb prosthesis and must be replaced when the patient's stump size changes. This study aims to design an adjustable socket that can be adjusted to the required size without manufacturing a new socket. In this study, the model was developed in SolidWorks and analyzed numerically using ANSYS. A tensile and fatigue test was performed for the materials used in manufacturing the socket, as well as an F-Socket test on an amputated person to measure the interface pressure between the stump and the socket to be used as a boundary condition during the numerical analysis process. The results demonstrated key achievements: the model was designed to serve as an alternative to the traditional model, thereby reducing costs in socket manufacturing due to growth or changes in stump size. The results also indicated the feasibility of using carbon fiber filament as an alternative to polypropylene and of employing additive manufacturing instead of the currently expensive methods.

Evaluating the effect of acid attack on concrete performance in harsh environments has been interesting for many researchers. This study investigated the effect of supplementary cementitious materials (SCMs) on improving the acid resistance of reactive powder concrete (RPC). Three RPC mixes, including a control, a mixture with 25% replacement of cement by fly ash, and a mixture with 25% replacement of cement with slag, were exposed to a 3% sulfuric acid solution. The deterioration of RPC was evaluated based on mechanical properties and weight loss. The results indicate that RPC mixtures containing fly ash or slag could improve their acid resistance. Slag induced the best acid resistance among 3-day cured mixtures, with 28% and 26% compressive and tensile strength loss, respectively. At the same time, fly ash induced the best acid resistance among 28-day cured mixtures, with a 29% compressive and tensile strength loss. The control mixture exhibited the highest weight loss after 56 days of exposure, with 22% and 14% for 3 and 28 days of curing, respectively, compared to other mixtures containing fly ash or slag, indicating that the use of SCMs can improve the resistance of RPC to sulfuric acid and enhance its durability.

The study aims to assess how a locally constructed enclosure affects a portable generator's noise generation and heat buildup, to address the risks posed by generator noise. This study compares working conditions with respect to sound level and engine temperature across three enclosure models and non-closure cases. The first model uses an air cavity between the plywood panels; the second model uses reeds as the insertion material; and the third model uses shredded plastics as the insertion material. The sound intensity (dB) at 3 and 5 m is obtained. In addition, the generator engine temperatures are also recorded. These recordings were obtained for generator loads of 0%, 25%, 50%, 75%, and 100%, both during the day and at night. The results show that the third model (i.e., the shredded-plastics model) achieves the most significant noise reduction. In contrast, the first model (i.e., the best in thermal performance) achieves the best thermal performance.

Human locomotion is achieved through a series of gait cycles. The kinetic analysis of human walking indicates repeated cycles of ground reaction force GRF at the stance phase for each foot. Such a cyclic excitation force can induce vibration that can be transmitted to the human body. In patients using a prosthesis, such as a below-knee Bk prosthesis, the vibration response can cause undesirable effects, leading to discomfort and abnormal gait. In this work, a mathematical model is derived to analyze periodic vibration induced by GRF in the BK prosthesis. In this model, the transfer function of the prosthesis device was evaluated from experimental data with the aid of System Identification SID found in MATLAB software. Fast Fourier transform FFT is used to decompose the periodic GRF excitation and evaluate natural frequencies and responses. It has been found that the excitation frequencies of periodic GRF can affect prosthesis vibration at higher walking speeds and the vibration levels of human organs, including the abdominal, shoulder, lung, and spinal cord regions.

Transporting oil products by truck has many issues, including increased accident risk, adverse environmental effects, and increased congestion in traffic. This study aims to compare trucks and trains for transporting fuel oil between intercity locations and to develop freight mode-choice models using an artificial neural network and statistical software. Freight trips collected in this study are (277) collected by a tracking device, questionnaires, and personal interviews. The data included the delivery time, average speed, quantity transported per trip, and transportation cost. According to the findings, the average speed of trucks and trains is (48.79) km/h and (24.13) km/h, respectively. This indicates that the average speed of a truck is nearly twice that of a train. Trucks and trains have average delivery times of (12.40) h and (25.92) h, respectively. This indicates that the average delivery time for a truck is half that of a train. The quantity transported each trip is (993.16) tons/trip for trains and (30.47) tons/trip for trucks. Train transportation is approximately 33 times as costly per trip as truck transportation. Transportation by train is a cheaper option than transportation by truck. Establishing an effective schedule can reduce delays at freight train intersections and during railway maintenance, potentially reducing delivery time by approximately 20 hours.

Data mining is concerned with revealing valuable patterns and insights out of big data sets, and machine learning forms a critical part in streamlining this effort. In any supervised classification task, decision tree algorithms become particularly beneficial since they provide understandable models and can be used to evaluate the significance of features. This paper assesses the work of YaDT as an example of a decision-making algorithm that uses the famous Titanic dataset. Provided a stringent statistical analysis to explore how the model behaves in different evaluation conditions. The findings reveal that YaDT builds a highly organized decision tree with strong generalization abilities, hence showing high classification ability. However, there was also a significant reduction in predictive reliability in some classes with very limited amounts of predictable data, indicating poor representation in the dataset. Additional evaluation of model performance using ROC analysis, based on cross-validation results, demonstrated comparable discriminative ability. Overall, it can be concluded that the findings favor the hypothesis that YaDT is a resilient, interpretable classifier, and as such, it can be competitive with the alternative machine-learning algorithms.

In this paper, a frequency-hopping orthogonal frequency-division multiplexing (FH-OFDM)- based differential chaos shift keying (FH-OFDM-DCSK) system under the effect of a sweep jammer is proposed. The wavelet packet jammer estimation algorithm (WPJE) is employed to enhance system performance by estimating jamming signals and mitigating them. Different wavelet filters and different filter lengths are considered. The threshold value was estimated using the threshold equation to produce an educated estimate of the jammer signal. As a result, we made an estimate as accurate as possible. The simulation results show that the proposed receiver substantially outperforms the standard receiver in system performance. In contrast, the BER performance difference between the presented system and the system without a jammer was 3 dB. The proposed receiver 5 end superscript with the parameters Eb/N0 = 20 dB, JSR = 5 dB, and beta = 100. The best outcomes were achieved by employing Daubechies of length 24 (db12).

This research aims to develop a spatiotemporal visualization of travel speed on urban streets to predict traffic conditions. Three segments of major streets and eight minor collector streets within Palestine Street in Baghdad were selected to examine the distribution of average travel speed. This road network comprises three primary links and six minor collector streets: link 1 (Al-Mawal to Al-Nakhala intersection), link 2 (Al-Nakhala intersection to Al-Sakhara intersection), and link 3 (Al-Sakhara intersection to Beirut intersection). The temporary congestion periods are (12 p.m. to 1 p.m.) and (5 p.m. to 7 p.m.) for Link 1, with speeds ranging from 34 to 35 km/hr, whereas Link 3 is more congested, with speeds of about 29 km/hr. Link 2 indicated moderated congestion. Most of the spatial congestion is either on links 1 and 3, which are the major distributors for production and attraction trips on Palestine’s urban streets. The visualization method based on field data reflects the actual traffic status of speed values. It reveals the temporal and spatial aggregation characteristics of urban travel speed as an integral part of understanding traffic operation behavior.

The durability of reinforced concrete columns can be compromised by steel bar corrosion, leading to weakening and an inability to withstand design loads. The current research investigates the combined effect of longitudinal and confining reinforcement corrosion on the axial capacity of RC columns. Nine column samples (110 x 110 x 1160 mm) were tested and subjected to an artificial electrical corrosion process to expedite mass loss in both longitudinal steel and tie bars. The columns experienced a significant reduction in ultimate load-bearing capacity due to the weakened bond between the concrete and the reinforcement steel. Corrosion of the reinforcing steel and the formation of iron oxide layers negatively impacted the columns' load capacity. According to the findings, the average crack widths are 0.38 mm at 10% mass loss and 0.49 mm at 20% mass loss, with maximum crack widths ranging from 0.37 mm to 0.64 mm. The ultimate loading capacity decreased by 18.5% to 51% for a 10% mass loss and 25% to 65% for a 20% mass loss compared to the reference column without corrosion.