Mcclureegeberg1972

Net primary productivity (NPP) has been widely used as the indicator of vegetation function and exhibits large spatial and temporal variations caused by numerous factors. Northwest China (NWC) is one of the driest regions in China, and water supply is the key determinant of NPP here. However, studies on the effects of water stress on NPP in NWC at the regional scale are still relatively lacking. Thus, in this study, based on a set of Moderate-Resolution Imaging Spectroradiometer (MODIS) NPP and evapotranspiration (ET) datasets, we quantified the response of NPP to water stress, which is indicated by crop water stress index (CWSI). Regional average of annual NPP in NWC showed an increasing trend during the study period, at a rate of 0.84 g C m-2 yr-1. At the province level, the NPP increase rates increased in the order of Ningxia (7.7%), Shaanxi (6.5%), Gansu (4.5%), Qinghai (3.8%), and Xinjiang (1.7%). NPP was negatively correlated with CWSI (p less then 0.05) in 73% of areas, indicating the key role of water stress in constraining NPP over this arid region. The effect of water stress on NPP changes with elevation. Water stress has the strongest negative impact on NPP in areas with elevations around 2000 m. In elevations above 5000 m, NPP is not limited by water stress, mostly positively correlated with CWSI. Our findings further clarify the importance of water stress in dryland ecosystems, while highlighting that elevation gradients can significantly affect the correlation between NPP and water stress.We study the pricing strategies of supply chains of green products under behaviour-based pricing. Considering consumer preferences for green product functional attributes and environmental attributes, we construct a two-stage supply chain. The optimal behaviour pricing of green products is solved, and the effects of green sensitivity and the cost coefficient on the optimal price are analysed. We find that when consumers are less sensitive to the greenness, with the increase in the market share of green products, green product retailers will increase the loyalty price. An increase in greenness sensitivity and a decrease in the greenness cost coefficient will increase the wholesale prices and retail prices of green products. Consumer attention to the greenness and a decrease in the initial market share of green products will be conducive to promoting the greenness and improving the environment. Consumers' emphasis on the greenness of their products will lead to higher profits for the manufacturers and retailers of green products.The occurrence of silver (Ag) in urban effluents is partly associated with the increasing use of silver nanoparticles (Ag NPs) as an antiseptic agent in various consumer products. Distinction among Ag forms must be taken into account in the assessment of exposure and toxicological effects to aquatic organisms. Wastewater treatment processes effectively remove Ag particles and colloids (mostly > 95%), but this still leaves notable concentrations (in order of ng/L) escaping to effluent-receiving waters. Total suspended Ag concentrations in various studied effluents ranged from 0.1 to 6 ng/L. The purpose of this study was then to measure and characterize Ag NPs in urban effluents for their concentrations and size distribution using the single particle ICP-MS technique (SP-ICP-MS). Wastewater influents and effluents from various treatment plants-from aerated lagoons to advanced treatment technology-were collected for three sampling days. Our results showed the presence of Ag NP in all samples with concentrations reaching 0.5 ng/L on a mass basis. However, on a particle number basis, Ag NP concentrations (expressed in particle/mL) in the 20-34-nm fraction (up to 3400 particles/mL) were much more abundant (> 700%) than in the > 35-nm larger fraction. The proportion of Ag at the nanoscale (1-100 nm) represents less than 8% of the total suspended Ag for all effluent samples, regardless of their origins. A significant correlation (linear regression r2 > 0.7) was observed between Ag NP and total suspended Ag concentrations in investigated effluents. Because Ag nanotoxicity is size dependent, the determination of size distribution and exposure concentration on a particle number basis is urgently needed for risk assessment of this class of nanoparticles.Ghana suffers from inadequate power supply due to increasing demand though it is amongst the African nations with the highest access to electricity. This research aims to assess the techno-economic potential of wind and solar energy potential for Ghana's northern part. We employ the Weibull distribution function, levelized cost of energy, and net present cost metrics for the economic study. The wind and solar energy resource's structure generated 72,284 kWh yearly. selleck Both systems were identified to be too expensive if implemented under the current financing conditions in the country. The PV systems generated 38,859 kWh/year, representing 53.76% of the total electricity generated in a year, generating renewable hydrogen in the country. The findings show that sizing and management of renewable plants will fulfill the basic annual cooking demands of the populations, which are 785 kg H2 in Ghana. The countries' capacity for developing solar hydrogen plants is further suggested by generating new solar hydrogen opportunity charts. Considering the significance of hydrogen energy under the renewable energy output, we recommend using hybrid systems for hydrogen production. The findings reveal which flexibility options are critical in key stages of the energy transition to a 70, 80, 90, and 100% renewable energy system.The nanometer effect in the process of arsenic ions removal on α-MnO2 nano-surface is studied by the first-principle method through microfacet models. Several parameters, such as adhesion energy, electrostatic potential, and Mulliken population were calculated to illuminate the internal mechanism. The results show that the adsorption energies of As(OH)3 molecules on MnO2[(100×110)] nanostructure are smaller than that on the bulk surface with the same concentration, which means the nanometer effect is beneficial to enhance the adsorption ability of MnO2 nano-surface. In an aqueous solution, there exist two possible removal ways of As ions. One is the direct reaction of As(OH)3→As(OH)6-, which occurs both in bulk surface and nano-surface. However, to nanomaterials, there exists another removal way of As(OH)3→As(OH)4→As(OH)6- through an intermediate As(OH)4 molecule produced by nanometer effect. Furthermore the smaller electrostatic potential of As ions on [(100×110)] nano-surface is beneficial to enhance the removal capability of As ions. Then the reason why MnO2 nanomaterials have better catalytic activity than the bulk materials is originated from its much less adhesion energy, much more removal ways, and much smaller electrostatic potential. So this research provides a detailed understanding of the removal capability of toxic ions influenced by a nanometer effect.Contamination of nine heavy metals (HMs) Zn, Pb, Cu, Cd, As, Co, Cr, Mo, and Ni in agricultural, urban, and wetland soils from Western and Rift Valley parts of Kenya was assessed using improved weighted index (IWI) and pollution loading index (PLI). Non-carcinogenic risks posed by the HMs were assessed using hazard quotients (HQ) and hazard index (HI), while carcinogenic risks were assessed using cancer risks (CR) and total cancer risks (TCR). The average concentration of Zn, Cr, Ni, Pb, Co, Cu, As, Mo, and Cd was 94.7 mg/kg, 43.6 mg/kg, 22.3 mg/kg, 21.0 mg/kg, 19.8 mg/kg, 18.0 mg/kg, 16.3 mg/kg, 1.83 mg/kg, and 1.16 mg/kg, respectively. IWI ranged from 0.57 to 6.04 and categorized 6.82% of the study sites as not polluted, 27.3% as slightly polluted, 43.2% as moderately polluted, and 22.7% as seriously polluted. PLI ranged from 0.38 to 3.95 and classified 15.9% of the sites as not polluted, 61.4% as slightly polluted, 20.5% as moderately polluted, and only 2.3% as seriously polluted. Wetlands retained more HMs from both urban and agricultural runoff and were therefore the most polluted. The heavy metals did not pose any risks via inhalation and dermal contact, but HQingestion for As for children was >1 in 2.3% of the sites studied. CR via ingestion and TCR for As were above the allowable limits for children and adults indicating high risks of cancer. Intensive agriculture and urbanization should be closely monitored to prevent further HM pollution.Regular monitoring and measurement of Legionella in tower water and preventive measures against contamination are particularly important in hospitals. This study aimed at risk assessment and disease burden because of legionella presence in cooling towers of Iran's central hospitals. Then its correlation with temperature, pH, turbidity, residual chlorine, and EC was investigated by the Pearson test. The health risk and burden of diseases caused by Legionella exposure were determined using QMRA and DALY models. Statistical analysis and modeling were performed in MATLAB2018. Of the total samples, 30-43% was infected with Legionella. The mean concentrations in hospital A and B were 5-102.5 ± 10 and 5-89.7 ± 0.7 CFU/L, respectively. Among environmental factors, turbidity and pH were the most effective factors in increasing and decreasing Legionella concentration, respectively. According to the QMRA model, the risks of Legionella infections and annual mortality in both hospitals were 0.2-0.3, 0-0.19, 2-2.9 × 10-5, and 0-0.7 × 10-5, respectively, which was higher than the acceptable risk range for Legionella (10-4-10-7). However, the trend of its change was negatively correlated with time (RB = - 0.77). According to the results, the concentration of Legionella and the exposure risk in both hospitals were higher than the permissible range, which is necessary to decrease to 0.1 current concentrations.In the current research, the energy and economic performance in single-slope solar still using ball marbles (BMSS) has been investigated and compared the results with conventional solar still (CSS) under the similar weather conditions of Karaikal (10.92° N, 79.83° E), India, during October 2020. The experiments have been conducted on both sunny and cloudy day to evaluate the performance of solar still. The BMSS has increased the evaporation rate and productivity when compared to CSS due to the sensible heat energy stored by the ball marbles in the absorber basin. The potable water yield of the BMSS is improved by 21.23% and 22.86%, respectively, during sunny and cloudy days. The maximum cumulative productivity obtained in the BMSS is 2950 mL/m2.day and 2150 mL/m2.day, respectively, on sunny and cloudy days. In economic analysis, the payback period (PBP) of the BMSS is 5.7 months, whereas the PBP of the CSS is 6.5 months, respectively. Furthermore, the cost per litre (CPL) potable water produced by BMSS is 8% lower than the CPL of CSS.This paper proposes a greener approach to the intensification of base oil recovery for truck engines (32,500 km of use) using ethanol, propan-2-ol, 2-methylpropan-1-ol, and butan-1-ol as solvents for the extraction of base oil, combining mechanical stirring (220 rpm) and ultrasound (25 °C, 24 kHz, and 400 W). The results indicated that the recovery yields of the base oil, using the mechanical stirring and ultrasound (MS-US) system, for ethanol, propan-2-ol, 2-methylpropan-1-ol, and butan-1-ol were approximately 3.1, 25.6, 71.6, and 85.5%, respectively. By contrast, the recovery yields using only mechanical stirring were 8.8, 28.9, 58.9, and 76.1%, respectively. The system with pre-extraction could effectively remove Ca (85.3-93.0%), Mg (67.2-82.9%), Na (31.7-62.5%), and Zn (0.0-71.7%). Finally, the results showed a reduction of almost 100% for the concentrations of Al, Cr, Fe, and Mo in the pre-extraction system. The mechanical stirring (5 min) and ultrasound (5 min) system were able to intensify the extraction process using environmentally friendly solvents.