Renewable energy scenario and environmental aspects of soil emission measurements

European Commission has set clear targets for 2020 regarding energy and environment policy; these targets include 20% cut in greenhouse gas emissions against the 1990 levels. It is believed that adopted strategy has encouraged the renewable energy applications during the last two decades. Moreover, measurement deviations of carbon dioxide flux occurring in respiration chambers has been seen of a great importance to explain the biochemical parameters affecting the climate change issue. This is attributed on many occasions to chamber design constraints and the way they are coupled with the studied site location. This is illustrated by external disturbances whereby when they happen while gas measurements are taken measurement deviations become more evident. This paper surveys the different soil physical, biological and geotechnical parameters and links them to meteorological ones. Consequently it explores their direct and indirect effects to the produced soil efflux. Furthermore this paper proposes several soil temperature models according to the studied case constraints to see what affects soil efflux production. Moreover a clear understanding of what affects the measurement process was achieved through surveying all the internal and external pressure parameters and how they influence the chamber in relation to time. The conclusion is that respiration chamber designers need to preserve chamber internal temperature and pressure to be equal to the outer atmosphere for the case of stabile external conditions. For the case of unstable external conditions design counter measures are incorporated. Furthermore the appropriate gas sensor needs to be selected professionally with emphasis on the importance of installation location inside the chamber. Likewise soil bacterial type and soil temperature also has an influence on efflux production

Prediction of the gas emission from porous media with the concern of energy and environment

Measuring soil carbon dioxide efflux is a challenging task even when it is performed using respiration chambers. While gas samples are taken, measurement deviations become more evident according to the used chamber design especially when external disturbances occur. This paper studies the carbon dioxide concentration profiles within the top soil layers, and investigates the controlling factors affecting the process. The considered factors are diffusion, temperature and viscosity. The efflux equation is discussed and then it is linked with the soils geotechnical parameters, while a relationship between the Reynolds number within the soil and efflux is found. Emphasis on the importance of the external geometrical design considerations is shown through studying external boundary layer effects due to the chamber outer shell shape and how it interacts with blowing winds. Chamber stability on site of deployment is also of a significant importance considering external blowing winds. Internal geometrical considerations are linked with the flow turbulence within the dynamic chambers. It is highly recommended that respiration chamber designers need to work in parallel with a multidisciplinary team in order to make a chamber design that ensures the least disturbance to occur at the location of study

A numerical and experimental study of a new design of closed dynamic respiration chamber

Carbon dioxide soil efflux modelling in closed dynamic respiration chambers is a challenging task. This is attributed on many occasions to the very small concentrations of carbon dioxide being transported between soil and the atmosphere. This paper describes a portable device which was made exclusively to accurately measure carbon dioxide efflux from soil locations. The blowing fan creates a forced convective flow to occur in the chamber making the K-Epsilon turbulence model a necessity to model the occurring flow in the respiration chamber gas domain. Furthermore the Darcy model is applied on the porous domain to model the flow pattern within the soil. The measurement process was achieved through measuring carbon dioxide concentration, temperature and relative humidity inside the chamber in relation to time. Simulation and experimental data is obtained using ANSYS and MATLAB. A significant agreement between the experimental and numerical results was achieved

Developments in fuel cell technologies in the transport sector

The demand for clean power source which can be used to run the various types of vehicles on the road is increasing on a daily basis due to the fact that high emissions released from internal combustion engine play a significant role in air pollution and climate change. Fuel cell devices, particularly Proton Exchange Membrane (PEM) type, are strong candidates to replace the internal combustion engines in the transport industry. The PEMFC technology still has many challenges including high cost, low durability and hydrogen storage problems which limit the wide-world commercialization of this technology. In this paper, the fuel cell cost, durability and performances challenges which are associated with using of fuel cell technology for transport applications are detailed and reviewed. Recent developments that deal with the proposed challenges are reported. Furthermore, problems of hydrogen infrastructure and hydrogen storage in the fuel cell vehicle are discussed

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

The Use of Moringa Oleifera Seed as a Natural Coagulant for Wastewater Treatment and Heavy Metals Removal

Moringa oleifera is a multipurpose tree of considerable potential and its cultivation is currently being actively promoted in many developing countries. The various uses and products of the tree are given. Seeds of this pan tropical tree contain water soluble, positively charged proteins that act as an effective coagulant for water and wastewater treatment. Water quality of Gebeng River (GR) was examined before and after the treatment. The preliminary laboratory results showed great potential of MO seed in the wastewater treatment applications. MO seed oil was extracted using ethanol up to 12.78% yield. MO seed has exhibited high efficiency in the reducing and preventing the bacterial growth in both Wastewater (WW) and Gebeng River (GR) samples. The turbidity was removed up to 85-94 % and dissolved oxygen (DO) was improved from 2.58±0.01 to 4.00±0.00mg/L. The chemical oxygen demand (COD) and biological oxygen demand (BOD) were increased after the treatment from 99.5±0.71 to 164.0±2.83mg/L for COD and from 48.00±0.42 to 76.65±2.33 mg/L for BOD. Nevertheless, there was no significant alteration of pH, conductivity, salinity and total dissolved solid (TDS) after the treatment. Heavy metals such as Fe were fully eliminated whereas Cu and Cd were successfully removed up to 98%. The reduction of Pb also has been achieved up to78.1%. Overall, 1% of MO seed cake was enough to curtail heavy metals from the water samples

Microbial Utilization Of Waste for Nanoparticles Production

The synthesis of silver nanoparticles (SNPs) extensively studied by using chemical and physical methods. Here, the biological methods were used and give benefits in research field in the aspect of very low cost (from waste to wealth) and safe time as well. The study aims to isolate and exploit the microbial power in the production of industrially important by-products in nano-size with high economic value, to extract highly valuable materials from hazardous waste, to quantify nanoparticle size, and characterization of SNPs by X-Ray Diffraction (XRD) analysis. Disposal X-ray films were used as substrate because it consumes about 1000 tons of total silver chemically produced worldwide annually. This silver is being wasted when these films are used and disposed. Different bacterial isolates were obtained from various sources. Silver was extracted as nanoparticles by microbial power degradation from disposal X-ray film as the sole carbon source for ten days incubation period in darkness. The protein content was done and all the samples were analyzed using XRD, to characterize of silver (Ag) nanoparticles size in the form of silver nitrite. Bacterial isolates CL4C showed the average size of SNPs about 19.53 nm, GL7 showed average size about 52.35 nm and JF Outer 2A (PDA) showed 13.52 nm. All bacterial isolates partially identified using Gram’s reaction and the results obtained exhibited that belonging to Bacillus sp. There are few reports on SNP synthesis by bacteria. In this paper, we report the synthesis of SNPs by Bacillus isolate. This is also the first report on production of SNPs from disposal X-ray film as the sole carbon source using bacterial power in darkness. According to (Table 1), the protein content of all the most potent bacterial isolates were higher than the control. The protein content exhibited the highest in case of JF Outer 2A PDA isolate than other samples

The role of nanoparticles in the inhibition of multidrug-resistant bacteria and biofilms

Until recently, one of the main reasons for mortality has been infectious diseases, and bacteria that are drug-resistant have emerged as a result of the wide application, as well as the misuse of antibacterial medications. Having multidrug-resistance, bacteria present a great problem for the efficient management of bacterial infections and this challenge has resulted in the creation of other means of dealing with bacterial diseases. Of late, metallic nanoparticles (NPs), employed as antibacterial agents, have the potential for use against resistance to bacterial drugs

Bioremediation of Hazardous Waste for Silver Nanoparticles Production

The synthesis of silver nanoparticles (SNPs) was extensively studied by using chemical and physical methods. In this study, the biological methods were used as it gave benefits in research field in the aspect of very low production cost (from waste to wealth) and time saving as well. The study aims to isolate and exploit the microbial power in the production of industrial important by-products in nano-size form with high economic value. It is also to extract the highly valuable materials from hazardous waste, to quantify nanoparticle size and characterization of SNPs by X-Ray Diffraction (XRD) analysis. Disposed X-ray films were used as substrate because it consumes about 1000 tons of total silver, which is chemically produced worldwide annually. The silver was wasted when these films were used and then disposed. Different bacterial isolates were obtained from various sources. Silver was extracted as nanoparticles by microbial power degradation from disposed Xray film as the sole carbon source for ten days incubation period in darkness. The protein content was added to all the samples and analyse using XRD to characterize the silver (Ag) nanoparticles size in the form of silver nitrite. Bacterial isolates labelled CL4C (isolated from rotten chicken liver) showed the average size of SNPs of about 19.53 nm, GL7 (isolated from Gambang Lake, Kuantan) showed about 52.35 nm and JF Outer 2A (PDA) (isolated from rotten jackfruit) showed 13.52 nm. All bacterial isolates partially identified using Gram s reaction and the results obtained exhibited that belonging to Bacillus sp