Papers by Keyword: Performance

Abstract: An effective and ecologically plastic waste (PW) management system that is either directly or indirectly related to the Sustainable Development Goals (SDGs) and waste to clean energy initiatives like SDGs 7, 11, 12, 13, and 14 can be achieved through the innovative and sustainable process of pyrolysis. The aim of this study is to evaluate the effectiveness of a miniature pyrolysis pilot plant developed to manage plastic waste generated in Ovia North-East, Nigeria. The PW utilized in this study was collected daily from residences, businesses, marketplaces, and hospitals. At the collecting location, it was categorized using plastic identification code into PET, HDPE, PVC, LDPE, PP, and PS. A bomb calorimeter (ASTM D 5865-85) was used to experimentally establish the sorted PW's heating value (HV). A thermogravimetric analyzer (SII 6300 EXSTAR, Seiko Instruments) was used to evaluate the mass loss of PW in order to ascertain how its composition varied with temperature and time. After being shredded to smaller pieces, the PW was put into the reactor both independently and in combination. To ascertain the pyrolysis oil yield (POY) from known masses of distinct PWs (0.5 kg, 1.5 kg----5 kg), a performance test was conducted. According to the results obtained, PET PW had the lowest hydrogen carbon (H/C) ratio when compared to other PW samples. The performance of the H/C ratio is arranged as follows: HDPE (0.2034) > LDPE (0.1971) > PP (0.1737) > PS (0.1290) > PVC (0.1278) >PET (0.1188). Additionally, the PWs with the highest heating values used in this study were HDPE (44.57 MJ/kg), LDPE (44.44 MJ/kg), PS (41.22 MJ/kg), PVC (41.01 MJ/kg), PP (44.53 MJ/kg), and PET (22.87 MJ/kg). Besides, the mixed plastic waste stream (MPWs) produces the most pyrolysis oil, although the POY yield potential varies according to the PWs' composition. Furthermore, the least amount of POY was recorded by PVC. The following is the order of the PW POY: MPWs > PS > HDPE > LDPE > PP > PET > PVC. This study has demonstrated that generated plastic waste in Ovia North-East LGA, Nigeria, can be processed into solid char and pyrolysis oil using the developed Miniature Pyrolysis Pilot Plant, thereby protecting the ecosystems, human health, resources, and the climate, which are in line with SDGs 3, 6, 14, and 15.

Abstract: Health monitoring systems for industry workers are needed to maintain their safety, health, productivity, and to prevent accidents using technologies to measure workers' physiological and environmental variables could predict and prevent potential human risk in industry. This study aimed to review several health monitoring systems to get information about their system designs, methods, requirements, and performances. Scoping keywords of industrial subjects, actions, health, and devices, along with their synonyms, are used to retrieve articles from the Scopus database from 2009 to June 2023. The screening results in 18 papers. The health monitoring system comprised of several types of personal health and environmental sensors, comprised of EEG, ECG, EMG, PPG, IMU, camera, FMCW, PIR, USR, and sensors of heart rate, body and environment temperature, respiratory rate, relative humidity, dust or particulate matters, noise, hazardous gases, air pressure, and UV. The supporting systems comprised processors, network infrastructures, servers, databases, software and algorithms, actuators, displays and websites, validators, and surveys. Those studies are done either by field or laboratory experiments, software simulations, secondary data analysis, or concept designs. The requirement insights are grouped into ten aspects: validity, effectivity, connectivity, functionality, reliability, safety and security, compatibility, economy, user-friendliness, and supportiveness. The system results and performances varied through the objective and sensor data used, from monitoring purposes to fatigue and health issue detection such as drowsiness, falling, stress depression, and distress. Fatigue and other health issues could be detected by camera image analysis, EMG, IMU, and HRV signals, not by HR or %HRR.

Abstract: This study aims to experimentally analyze the performance of a forced wet cooling tower (WCT) using a multi-level inclined perforated splash fill. The hot water temperature adjusts to 60 °C; Packing has inclination angles of 15^o, 20^o, 25^o and a perforation ratio of 2.6%, consisting of five levels of galvanized plate fill. Water flow rate ± 0.0917 kg/s, five variations of air flow rate are 0.02033, 0.02631, 0.02995, 0.03770, and 0.04261 kg/s. The inlet hot water temperature is 60 °C. In this study, the best WCT performance occurred at an inclination angle of 15^o.

Abstract: A wet cooling tower is an apparatus for transferring heat and mass that directly links hot water and air movement. Because the wet cooling tower provides a large surface area for heat and mass transfer, fill is essential to the tower. This study uses experiments to investigate the performance of a multi-level inclined perforated splash fill in a forced wet cooling tower (WTC). The packing has a 2.6%, 3%, and 3.6% perforation ratio and an inclination angle of 15 degrees, with five layers of galvanized plate fill. The hot water temperature is adjusted to 60 degrees Celsius. The airflow rate varies five times: 0.02033, 0.02631, 0.02995, 0.03770, and 0.04261 kg/s. The water flow rate is ± 0.0917 kg/s. The hot water at the inflow is 60 degrees Celsius. The findings of this study indicate that the cooling efficiency of cooling towers may be significantly improved by raising the mass airflow rate and adopting the suitable perforation ratio.

Abstract: Fire produces unique effects on steel structures which can compromise the residual capacity and therefore the structural response if they impact jointly with other natural hazards, such as earthquakes. This work presents a procedure that allows for the extension of the analysis method introduced in the 1990s by Fajfar and Gaspersic and outlined in EC8 (referred to as the N2 method) for the case of Multi-Hazard (MH) analysis, specifically for hazard-chain scenarios involving earthquake and fire. The goal is to assess the structural performance at the end of the sequence of considered events. By appropriately modeling the structure considering elasto-plastic behaviour, it becomes possible to observe the structural response as the plasticization of structural elements progresses: in this context, accounting for material and geometric nonlinearities has proven essential, since the material and structure's behaviour under fire are governed by complex phenomena, due to the significant deformations and distortions involved. The hazard-chain scenario here discussed is characterised by the consecutiveness of main earthquake event and fire; the proposed procedure is then applied to a 2D steel structure. Results highlight that neglecting possible hazard interactions could lead to an erroneous evaluation of the residual structural capacity.

Abstract: Due to the demeaning character of fossil fuels and their detrimental harmful effects on the ecosystem, studies have focused on finding appropriate non-edible replacements. In the present research, the emissions and performance features of the blends of biodiesel generated from the chosen raw materials (flamboyant seed), which includes B25, B50, B75, and B100, were evaluated in the early stages of the research. A diesel engine continues to operate at an authorized rate of 1500 rpm. In the following phase of the research, the focus is on defining the appropriate blend's performance as well as its emission characteristics under the ideal operating circumstances. The FME blend B25 is found to be satisfactory, and the optimal parameters to stated standards have been CR 18.5.With the exception of NOX emission, the ideal blend surpassed alternatives in terms of BSFC and BTHE associated with reduced CO and HC outputs. The optimum fuel's BSFC and BTHE at the maximum load, for CR 18.5, are 0.257 kg/kW-hr and 31.47%, respectively. The emission levels of CO, HC, and NO_X are 0.08%, 51 ppm, and 1029 ppm.

Abstract: With the development of radar-detecting technology, stealth technology is important for military weapons and equipment. As a typical structural stealth material, wave absorption honeycomb has a wide range of application prospects and research value. The light and high absorption wave absorption honeycomb that uses electromagnetic-modified aramid paper as a raw material has the advantages of light density and good absorption performance, making it suitable for the lightweight requirements of the new equipment. Here, the electromagnetic-modified aramid was the raw material of the honeycomb. The hexagon honeycomb and overexpanded honeycomb were prepared. We also analyzed the influence of the cell shapes on the honeycomb properties. The results showed that cell shapes had little effect on the plane compression and shear performance of L. The overexpanded honeycomb’s L and W shear performance was basically the same. The hexagon and overexpanded honeycomb have good electromagnetic wave absorption performance in 1 GHz ~ 18 GHz frequency band.

Abstract: In the comparative study of single mixed PVA fiber (0,1%, 2%, 3%) and basalt fiber (0,0.1%, 0.2%, 0.3%) on the polymer mortar fluidity and mechanical properties, the results show that: PVA fiber and basalt fiber under the appropriate amount can improve mortar water retention, basically will not appear water phenomenon, which makes the construction more convenient. When the basalt and PVA fibers were 0.2%, the 28-d folding resistance was 5.60 MPa and 5.72 MPa, respectively. The results of the compressive strength test showed the same pattern as the folding strength. When the amount of PVA and basalt fiber was 0.2%, the 28-d folding strength was the greatest, which is 44.91 MPa and 41.92 MPa, respectively.

Abstract: The properties and the performance of Thermally Stable Diamond Composite (TSDC) directly affect the applications of TSDC in engineering. The failure risk of the TSDC cutting tips during a cutting process is affected by many factors, including the Depth of Cut (DOC) of the pick with the TSDC tip. The DOC is an important indicator in mining and construction industries because it directly affects productivity and pick failures. In existing studies, DOC is usually treated as a deterministic variable. However, due to the drum vibration during a cutting process, the DOC during production often varies randomly around its nominal value. This study investigates the influence of the randomly varied DOC on the performance and failure characteristics of TSDC tipped rock cutting picks, in combination with random resultant angle. Monte Carlo simulation method is applied. It is found that the variation in DOC can have considerable influence on the failure characteristics of the TSDC cutting tips, although this influence is affected by the resultant angle and attack angle. This characteristic is important for optimising the design and application of the TSDC tipped picks.

Abstract: This paper presents a comprehensive investigation into the thermal performance of microchannel heatsinks featuring varying geometries. The investigation was carried out utilizing computational fluid dynamics (CFD) simulations. Computational Fluid Dynamics (CFD) simulations have demonstrated potential as a viable method for prognosticating system performance. This study involved the modeling and analysis of three primary microchannel heatsink configurations, namely uniform, convergence, and divergence, utilizing ANSYS package v.22.1. The study examined the various parameters that affect microchannel heatsinks and evaluated their thermal performance. The investigated case involved laminar flow through microchannels of varying cross sections in a heat sink, where the Reynolds number is equal to 129. Steady state flow, incompressible fluid, neglecting radiation and natural convection, constant characteristics, and negligible viscous dissipation were assumed in the study. The results emphasize the significance of microchannel geometry and flow configurations in augmenting heat dissipation. The results were subjected to numerical validation, which demonstrated a high level of concurrence with prior research. The reliability of the numerical model was validated, thereby substantiating its suitability for utilization in simulations. The convergence microchannel, specifically in Case no.2, and the divergence microchannel, specifically in Case no.7, exhibited optimal performance. In the second case, there was a notable average improvement rate of 35%, which suggests that the heat dissipation capabilities were superior. Cases 3 through 11 demonstrated favorable outcomes, with improvement rates varying from 2.7% to 30%. Conversely, Cases 12 and 13 exhibited less satisfactory results. In conclusion, this research highlights the importance of microchannel heatsinks in effectively addressing thermal issues in electronic systems. The utilization of convergence and divergence microchannel configurations, in conjunction with carefully selected geometric parameters, exhibits the potential for efficient heat dissipation.