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

Adsorption Cooling System Employing Activated Carbon/R32 Adsorption Pair

This paper reports the performance of an adsorption cooling system employing activated carbon powder (Maxsorb III)/R32 adsorption pair. The system has been modeled and simulated numerically and the effect of changing the operating conditions has been studied. The system has been simulated to driven by a low-grade heat source temperature below 90ºC and effectively employs solar heat and/or waste sources to drive the system

Experimental study on Egyptian biomass combustion in circulating fluidized bed

The present study investigates the combustion of four kinds of biomass in a circulating fluidized bed. The combustion chamber is a steel cylinder with 145 mm inner diameter and 2 m height. Tests were conducted on wheat straw, sawdust-wood, cottonseed burs, and corncobs. Excess air was varied for each fuel. Temperature, heat flux and gas emissions were measured along the combustion chamber and at the chimney inlet. Results showed that sawdust-wood produces the highest values of CO emissions (about 3000 mg/Nm3). On the other hand, cottonseed burs produce the lowest values of CO emissions (about 250 mg/Nm3). The SO2 emissions were very low in all tests (less than 20 mg/Nm3). The lowest emission value occurred at an excess air ratio (EA) of 1.24 except for cottonseed burs where it was 1.4.Biomass Fluidized bed combustion Pollutant emissions Renewable energy

Immediate, short-term, and long-term effects of balloon mitral valvuloplasty on the left atrial global longitudinal strain and its correlation to the outcomes in patients with severe rheumatic mitral stenosis

Abstract Background Left atrial global longitudinal strain (LA GLS) has been used as a new assessment tool for left atrial function. This article aims to investigate the effect of balloon mitral valvuloplasty (BMV) in patients with severe rheumatic mitral stenosis on LA GLS and its relation to the mitral valve area achieved after the procedure. The study included 95 patients with severe mitral stenosis who fulfilled the criteria for BMV (case group) and 80 normal healthy subjects (control group). All included participants underwent complete echocardiographic examinations. For the case group, LA GLS was assessed by 2D speckle-tracking Echocardiography before valvuloplasty, immediately after, within 24 h, at 6 months, and at 12 months, and the results were compared. Results The impaired left-atrium strain in patients with severe mitral stenosis was improved immediately after BMV, and the improvement continued at 6 and 12 months post-BMV (23.1% ± 4.2 vs. 36.0% ± 4.9, 36.2% ± 4.5, and 40.1% ± 9.5, respectively p < 0.01). After BMV, there was a significant decrease in left atrial volume (76.3 ± 12.4 ml/m2 vs. 68.6 ± 10.4 ml/m2, p < 0.01) and a significant increase in the area occupied by the mitral valve (1.02 ± 0.18 cm2 vs. 1.60 ± 0.31 cm, p < 0.01). The immediate LA GLS and the mitral valve area were positively correlated (r = 0.64, p < 0.01). Furthermore, the immediate LA GLS was associated with significantly improved function class (p < 0.01). Conclusions LA GLS can indicate left atrial (mainly reservoir) function. The improvement observed in patients after BMV may indicate that LA GLS can be used to evaluate the progress after BMV. Trial registration: The study was approved by the local ethics committee of the Faculty of Medicine in Minia University (Registration No. MUFMIRB 324-4-2022). Institutional Review Board, Faculty of Medicine, Minia University, Egypt. 324-4-2022, 24 18 April, 2022

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