41 research outputs found
A state of the art of required techniques for employing activated carbon in renewable energy powered adsorption applications
This paper reviews, for the first time, the measurement adsorption characteristics techniques to facilitate optimal testing of the validity of adsorbent materials in adsorption applications. Thermo-physical properties, adsorption characteristics and modelling techniques are presented. The characterisation of material thermo-physical properties includes true and bulk densities, specific heat capacity, surface area, pore volume distribution and thermal conductivity. The adsorption characteristics were categorized into adsorption isotherms and kinetics including experimental and theoretical equations. A range of models used in the simulation of adsorption cooling systems is presented and discussed. The paper highlights the conditions for which each measurement technique is most suitable and the limitations of modelling techniques, which is a vital element in the robust assessment of the performance of adsorption cooling units
Experimental and computational study on utilising graphene oxide for adsorption cooling and water desalination
The adsorbent materialâs thermal and sorption characteristics are the critical criteria that affect the adsorption systemsâ overall performance. Therefore, this paper experimentally and computationally studies the utilisation of graphene oxide of a few atomic layers as a parent adsorbent material owing to its reported high thermal performance potential. Graphene oxide performance was benchmarked against the widely investigated silica gel adsorbent, emphasising adsorption cooling cum desalination application as the most needed to address the lack of sustainable cooling and clean water scarcity. Quantitative and qualitative analyses were undertaken to determine the influence of the evaporator temperature, cycle time and heat source temperature on the material and system levels. The results showed that graphene oxide enhances thermal performance by 44% compared to silica gel and adsorption by up to 57%. Furthermore, graphene oxide, compared to silica gel as a parent adsorbent, enhanced the systemâs specific daily water production by up to 44.4%, the specific cooling power by up to 29.5%, the coefficient of performance by up to 17.2% and the exergy efficiency by up to 15.8%
Comparative study to determine the proper sequence of simulation training, pelvic trainer versus virtual reality simulator: a pilot study
Abstract Background Increased surgical efficacy has led to a remarkable increase in the usage of minimally invasive surgical procedures since their inception. The use of simulation in surgical teaching has grown significantly during the past 10Â years. Several laparoscopic simulators have been built. Virtual reality (VR) simulators and box trainers (BTs), often known as pelvic trainers, are the two primary training modalities used in hospitals and clinical training institutes for the development and acquisition of laparoscopic skills. Our study aimed to evaluate the proper sequence of pelvic trainers and VR simulator training to improve laparoscopic gynecological skills. Methodology We carried out this pilot study at the Virtual Endoscopic Simulation and Skills Acquisition Laboratory at the Obstetrics and Gynecology Department in the Kasr Al Ainy Hospital, Faculty of Medicine, Cairo University, Egypt, from February to August 2022. All residents with minimal or without laparoscopic experience (twenty residents) were divided into two groups and classified as (group A versus group B). Group Aâs training began with a pelvic trainer, which was tested using a checklist. Later, the group trained on a virtual reality simulator, which tested them using an electronic autoassessment. After training on a virtual reality simulator and passing an electronic autoassessment test, group B moved on to pelvic trainers and had a checklist-based assessment. Results We compared pelvic trainer tasks between the training groups, and detected no significant differences in camera navigation, cutting pattern, peg transfer, or running stitches (P values 0.646, 0.341, 0.179, and 0.939 respectively); when we compared VR simulator tasks between the training groups, there were no significant differences in camera navigation, cutting pattern, peg transfer, or running stitches (P values 0.79, 0.3, 0.33, and 0.06, respectively). Conclusion There was no difference in training, between residents who started on a pelvic trainer or the VR simulator; therefore, both could be used in laparoscopic training with no preferred order. Trial registration The trial was registered at clinicaltrials.gov with the name âPelvic trainer vs VRSâ and the identifier âNCT05255614.â The registration date was January 19, 2022, and the trial was prospectively registered. URL: https://register.clinicaltrials.gov/prs/app/action/ViewOrUnrelease?uid=U0004GED&ts=22&sid=S000BR5D&cx=t6mc1
A state of the art of required techniques for employing activated carbon in renewable energy powered adsorption applications
This paper reviews, for the first time, the measurement adsorption characteristics techniques to facilitate optimal testing of the validity of adsorbent materials in adsorption applications. Thermo-physical properties, adsorption characteristics and modelling techniques are presented. The characterisation of material thermo-physical properties includes true and bulk densities, specific heat capacity, surface area, pore volume distribution and thermal conductivity. The adsorption characteristics were categorized into adsorption isotherms and kinetics including experimental and theoretical equations. A range of models used in the simulation of adsorption cooling systems is presented and discussed. The paper highlights the conditions for which each measurement technique is most suitable and the limitations of modelling techniques, which is a vital element in the robust assessment of the performance of adsorption cooling units.</p