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Leakage of CO2 from geological storage and its impacts on fresh soil–water systems: a review Полный текст
2020
Gupta, Pankaj Kumar | Yadav, Basant
Leakage of CO2 from geological storage and its impacts on fresh soil–water systems: a review Полный текст
2020
Gupta, Pankaj Kumar | Yadav, Basant
Leakage of CO₂ from the geological storage is a serious issue for the sustainability of the receiving fresh soil–water systems. Subsurface water quality issues are no longer related to one type of pollution in many regions around the globe. Thus, an effort has been made to review studies performed to investigate supercritical CO₂ (scCO₂) and CO₂ enrich brine migration and it's leakage from geological storage formations. Further, the study also reviewed it's impacts on fresh soil–water systems, soil microbes, and vegetation. The first part of the study discussed scCO₂/CO₂ enrich brine migration and its leakage from storage formations along with it's impact on pore dynamics of hydrological regimes. Later, a state-of-the-art literature survey has been performed to understand the role of CO₂–brine leakage on groundwater dynamics and its quality along with soil microbes and plants. It is observed in the literature survey that most of the studies on CO₂–brine migration in storage formations reported significant CO₂–brine leakage due to over-pressurization through wells (injections and abandoned), fracture, and faults during CO₂ injection. Thus, changes in the groundwater flow and water table dynamics can be the first impact of the CO₂–brine leakage. Subsequently, three major alterations may also occur—(i) drop in pH of subsurface water, (ii) enhancement of organic compounds, and (iii) mobilization of metals and metalloids. Geochemical alteration depends on the amount of CO₂ leaked and interactions with host rocks. Therefore, such alteration may significantly affect soil microbial dynamics and vegetation in and around CO₂ leakage sites. In-depth analysis of the available literature fortifies that a proper subsurface characterization along with the bio-geochemical analysis is extremely important and should be mandatory to predict the more accurate risk of CO₂ capture and storage activities on soil–water systems.
Показать больше [+] Меньше [-]Leakage of CO2 from geological storage and its impacts on fresh soil–water systems: a review Полный текст
2020
Gupta, Pankaj Kumar | Yadav, Basant
Leakage of CO2 from the geological storage is a serious issue for the sustainability of the receiving fresh soil–water systems. Subsurface water quality issues are no longer related to one type of pollution in many regions around the globe. Thus, an effort has been made to review studies performed to investigate supercritical CO2 (scCO2) and CO2 enrich brine migration and it's leakage from geological storage formations. Further, the study also reviewed it's impacts on fresh soil–water systems, soil microbes, and vegetation. The first part of the study discussed scCO2/CO2 enrich brine migration and its leakage from storage formations along with it's impact on pore dynamics of hydrological regimes. Later, a state-of-the-art literature survey has been performed to understand the role of CO2–brine leakage on groundwater dynamics and its quality along with soil microbes and plants. It is observed in the literature survey that most of the studies on CO2–brine migration in storage formations reported significant CO2–brine leakage due to over-pressurization through wells (injections and abandoned), fracture, and faults during CO2 injection. Thus, changes in the groundwater flow and water table dynamics can be the first impact of the CO2–brine leakage. Subsequently, three major alterations may also occur—(i) drop in pH of subsurface water, (ii) enhancement of organic compounds, and (iii) mobilization of metals and metalloids. Geochemical alteration depends on the amount of CO2 leaked and interactions with host rocks. Therefore, such alteration may significantly affect soil microbial dynamics and vegetation in and around CO2 leakage sites. In-depth analysis of the available literature fortifies that a proper subsurface characterization along with the bio-geochemical analysis is extremely important and should be mandatory to predict the more accurate risk of CO2 capture and storage activities on soil–water systems.
Показать больше [+] Меньше [-]A state of the art on solar-powered vapor absorption cooling systems integrated with thermal energy storage Полный текст
2020
Sharma, Dinesh Kumar | Sharma, Dilip | Ali, Ahmed Hamza H.
The intermittent nature of solar energy is a dominant factor in exploring well-designed thermal energy storages for consistent operation of solar thermal-powered vapor absorption systems. Thermal energy storage acts as a buffer and moderator between solar thermal collectors and generators of absorption chillers and significantly improves the system performance. Vapor absorption chillers are available in half, single, double, and triple-effect modes of operation and operate at temperatures ranging from 75 to 220 °C to produce a cooling effect with COPs ranging from 0.3 to 1.8. Thus, the selection of appropriate solar collectors and thermal energy storages are two significant decisions affecting the consistency of output of a vapor absorption refrigeration system. The present review of state of the art is focused on the appropriate selection, from among different types of solar collectors available to meet the demand of capacity and degree of thermal energy required in operating absorption chillers at optimum performance. Characteristics of various thermal energy storage systems and their integration with solar thermal collectors and absorption chillers are also investigated to meet the demand for heat during non-sunshine hours or periods of low solar intensity. In the latter section, economic feasibility is explored so that a sustainable solar cooling system can be proposed which can work consistently with the best performance throughout its entire life.
Показать больше [+] Меньше [-]Concrete with Shirasu aggregates for sustainability: a review on research progress and application in Japan Полный текст
2020
Cai, Gaochuang | Noguchi, Takafumi
This paper presents a critical review of the main research progress and application of Shirasu concretes in Japan recently. As a kind of pyroclastic-flow deposits, Shirasu aggregate was considered as one kind of nonstandard aggregates for modern concrete industries because it usually has a low density and a high water content rate, and also contains a large amount of fine powder on its surface. However, with the considerations that Shirasu has a high level of pozzolanic activity and can be available widely and easily in Japan, many studies had been performed in Japan in the last two decades. The key concerns in the paper focus on the basic fresh properties of Shirasu raw material, the mix design, and the basic material properties of Shirasu concretes. Based on this review, several recommendations were provided for future works. Through the review, Shirasu concrete considered as a construction material could present accepted material properties compared with traditional concrete, including basic fresh and mechanical, and durability properties. It was suggested to apply concrete structures with careful concerns and recommended to structures under several special environments. Using this aggregate, several kinds of high-performance concrete also could be produced.
Показать больше [+] Меньше [-]Effects of juvenile crucian carp (Carassius carassius) removal on submerged macrophyte growth—implications for subtropical shallow lake restoration Полный текст
2020
Rapid expansion of juvenile fish after biomanipulation can delay the successful restoration of submerged macrophytes, leading to a turbid water status in subtropical shallow lakes. Aimed to test the effects of direct removal of juvenile crucian carp (Carassius carassius) on water quality and growth of two submerged macrophytes Vallisneria natans and Hydrilla verticillate, a short-term outdoor mesocosm experiment was conducted in the Taihu Laboratory for Lake Ecosystem Research (TLLER). The results indicated that the concentrations of TN, TP, suspended solids, and chlorophyll a decreased significantly with increasing removal density of juvenile crucian carp, thus resulting in a clear status of the water. Additionally, the mean relative growth rate of V. natans and H. verticillata in the low- and high-density removal treatments were higher than that in the controls. Moreover, the removal of juvenile crucian carp also significantly increased the stem length of V. natans, but no significant effect on that of H. verticillata. Meanwhile, the total number of V. natans and H. verticillata in the low- and high-density removal treatments was higher than that in the controls, but all of H. verticillata were lower than the initials. Our results indicated that removing juvenile crucian carp could improve the water quality, increasing relative growth rate, height, and reproduction of V. natans, and improving the survival rate of H. verticillata. The promotion of fish removal on the V. natans growth was greater than H. verticillata. The results also implied that it was necessary to continuously remove the juvenile benthivorous fish several times for restoring the submerged macrophytes in shallow lakes.
Показать больше [+] Меньше [-]Examining the spatiotemporal change of forest resource carrying capacity of the Yangtze River Economic Belt in China Полный текст
2020
Tang, Xu | Guan, Xingliang | Lu, Shasha | Qin, Fan | Liu, Xu | Zhang, Dahong
Rapid urbanization and the excessive human harvesting of forests have led to a continuous decline in the carrying capacity of forests in China. As a result, quantitative means of measuring forest resource carrying capacity are greatly needed, with a view to identifying problem areas and their causes and formulating effective response strategies. This paper puts forward a framework and methodology for constructing a forest resource carrying capacity index (FRCCI). To do this, we first calculate a forest ecological security index (FESI), using an evaluation index system. Ideal FESI values are then simulated by introducing a forest ecological location coefficient (FELC), and the FRCCI is obtained as the difference between the ideal FESI and the FESI. The study considers the 1086 counties that compose the Yangtze River Economic Belt in China, using forest and socioeconomic data for 2015. The resulting FRCCI values indicate that the forests of Yunnan province are generally in a state of “no overload,” while Sichuan, Guizhou, Chongqing, Hunan, Hubei, Jiangxi, and Zhejiang provinces occupied a state of “critical overload” and Anhui and Jiangsu provinces experienced “general overload.” The spatial pattern of the FRCCI in the study region presented significant centralization, with high FRCCI values mainly clustered in areas in the upper reaches of the Yangtze River and low FRCCI values mainly clustered in areas in the midstream and downstream reaches of the River. The study identifies 416 counties identified as forest carrying capacity problem areas (38.31% of the study area); these areas were mainly concentrated in Shanghai and Anhui province. We argue that a number of measures would be helpful in improving FRCCI values, including promoting the forest state index by strengthening reforestation as well as afforestation, reducing the external pressure on forests by means of energy saving and emission reduction strategies, and formulating comprehensive policy measures to promote the carrying capacity of forests in the whole study area and in the problem areas.
Показать больше [+] Меньше [-]Knowledge, attitudes, and practices of Egypt’s future physicians towards antimicrobial resistance (KAP-AMR study): a multicenter cross-sectional study Полный текст
2020
Assar, Ahmed | Abdelraoof, Mohamed Ibrahim | Abdel-Maboud, Mohamed | Shaker, Kerollos H. | Menshawy, Amr | Swelam, Asia Hamdy | Eid, Muhammad | Khalid, Radwa | Mogahed, Mohamed | Abushouk, Abdelrahman I. | Aleya, Lotfi | Abdel-Daim, Mohamed
Antimicrobial resistance (AMR) is a growing threat that causes over 700,000 deaths per year worldwide. The goal of the current multicenter, cross-sectional study was to identify the knowledge and practice gaps in antimicrobial stewardship among Egypt’s undergraduate medical students. Nine-hundred and sixty-three participants (375 male) from 25 medical schools responded to our self-administered questionnaire. Overall, the majority of students (96%) exhibited fair/satisfactory knowledge and attitude scores towards AMR. However, the most common misconceptions were that skipping one or two antimicrobial doses does not contribute to AMR (43%) and that antimicrobials are the drug of choice for the treatment of sore throat (38.8%). About 36% of the students thought that bacteria cause common cold and influenza. In terms of practices, about 62% of the students reported taking antibiotics when they have cough or sore throat and saving the remaining antibiotic for the next time. About 48% of the students reported that when they start feeling better, they stop the antibiotic course, and 41% stated that they often/sometimes discard the remaining leftover or share the leftover antibiotics with their friends. Interestingly, males had more frequently poorer levels of knowledge than females (p = 0.02). Moreover, students in the clinical science years (p < 0.001), living in urban areas (p = 0.02) or Cairo (p < 0.01) reported better practices than their counterparts. Educational programs about antimicrobial stewardship and the role of healthcare professionals in preventing AMR should be introduced early in medical curricula. Further, active educational techniques as clinical scenarios that simulate clinical settings and interactive learning workshops would be more efficient teaching methods.
Показать больше [+] Меньше [-]A case-control study of arsenic exposure with the risk of primary ovarian insufficiency in women Полный текст
2020
Pan, Wuye | Ye, Xiaoqing | Zhu, Zheying | Li, Chunming | Zhou, Jianhong | Liu, Jing
Arsenic, a well-known toxic metalloid, is ubiquitously existed in environment. Arsenic exposure has been associated with female reproductive health. However, a potential association between arsenic exposure and primary ovarian insufficiency (POI) in women has not been recognized yet. In this case-control study, a total of 169 POI cases and 209 healthy controls were recruited to determine urinary concentrations of arsenic and serum levels of reproductive hormones (follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Mullerian hormone (AMH) and estradiol). The median concentration of urinary arsenic in cases (21.5 μg/L, 28.0 μg/g for creatinine adjustment) was significantly higher than that of controls (13.8 μg/L, 19.3 μg/g for creatinine adjustment). Urinary arsenic concentrations were significantly positively associated with the risk of POI (adjusted odds ratio (OR) = 2.66, 95% CI: 1.43–4.95 for the highest vs lowest tertile of arsenic, p = 0.002; p for trend = 0.004). We also assessed the associations between arsenic exposure and reproductive hormones that are important for ovarian functions. FSH and LH levels were positively associated with urinary arsenic, whereas AMH and estradiol levels were negatively correlated with this element. This study provided evidence that arsenic exposure could be the potential risk factor for POI in women.
Показать больше [+] Меньше [-]In vivo protective effects of Ginkgo biloba L. leaf extract against hydrogen peroxide toxicity: cytogenetic and biochemical evaluation Полный текст
2020
Yalçın, Emine | Çavuşoğlu, Kültiğin | Acar, Ali | Yapar, Kürşad
In this study, the protective effects of Ginkgo biloba leaf extract (GbE) against toxicity induced by hydrogen peroxide (H₂O₂) in Swiss albino mice were investigated. Abnormal metaphase number (AMn), mitotic index (MI), micronucleus (MN), and chromosomal abnormalities (CAs) were analyzed for cytogenetic effects. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), blood urea nitrogen (BUN), creatinine, glutathione (GSH), and malondialdehyde (MDA) levels in liver and kidney organs were investigated as indicators of biochemical toxicity. Six experimental groups were formed as a control and treatment group, each containing six animals. The mice in the control group were given tap water, while the mice in the administration group received two different doses of GbE and H₂O₂ for 45 consecutive days. It was observed that H₂O₂ administration caused a significant decrease in MI compared to the control group and caused a significant decrease in the frequency of AMn, MN, and CAs. Chromatid break was the most common type of CAs induced by H₂O₂, and the other CAs types observed in this study were chromosome break, fragment, dicentric, gap, and ring. It has been determined that GbE treatment decreases the clastogenic effects of H₂O₂ and reduces the MN and CAs frequency and causes a re-increase in mitotic cell numbers. It was determined that H₂O₂ administration caused changes in biochemical parameters and resulted in significant increases in serum AST, ALP, ALT, BUN, and creatinine levels. However, the level of MDA, which is an indicator of oxidative damage, increased, and GSH level decreased in liver and kidney tissues. Oxidative damage caused by H₂O₂ in liver and kidney tissues was improved, and all biochemical parameters tested were found to be ameliorated after GbE treatment. This improvement was dependent on the dose of GbE, and improvement in 150 mg/kg bw GbE was found to be more prominent. As a result, the GbE can be used as an antioxidant nutritional supplement to protect against the toxic effects of environmental agents such as H₂O₂.
Показать больше [+] Меньше [-]Evaluation of Culex quinquefasciatus wings asymmetry after exposure of larvae to sublethal concentration of ivermectin Полный текст
2020
Alves, Stênio Nunes | Pujoni, Diego G. F. | Mocelin, Giovani | Melo, Alan L. | Serrão, José E.
The surviving insects submitted to chemical control have morphological alterations that impact on their mechanisms of resistance and their final development. Those changes are detected and measured using physical features related to symmetry, specifically named fluctuating asymmetry. This is detected when deviations from the perfect bilateral symmetry for specific morphological characteristic is influenced by genetics or environmental stress. Thus, in this paper we analyze the wing in adult of Culex quinquefasciatus (Diptera - Culicidae) after larvae exposure to ivermectin LC₅₀. Three hundred larvae of C. quinquefasciatus were exposed to ivermectin in 1.5 μg/L (LC₅₀) concentration during 30 min, and three hundred larvae were exposed to distilled pure water as control group. For fluctuating asymmetry, adult males and adult females were selected from each group (n = 83) from the untreated group and (n = 79) from treated group. Wings from adults of each group were mounted in glass microscope slides and coverslip in Canada’s balsam and analyzed with a stereomicroscope with a video camera attached. The treatment effect on M₃ ₊ ₄ was marginally significant with higher asymmetry values in the control group. The data obtained here suggest the importance of future experiments to elucidate the mechanisms associated with FA. Moreover, according to the results obtained, it may be suggested that FA is present in females in ornaments, or secondary sexual characters, as an indicator of phenotypic quality of the partners.
Показать больше [+] Меньше [-]Regional differential decomposition and convergence of rural green development efficiency: evidence from China Полный текст
2020
Yu, Cui | Wenxin, Liu | Khan, Sufyan Ullah | Yu, Cai | Jun, Zhu | Yue, Deng | Zhao, Minjuan
An objective understanding of the current situation and influencing factors of rural green development in China is an important prerequisite for effective formulation making of green development policies. Based on the panel data of 31 provinces of China from the year 1997 to 2017, this paper constructs and measures the rural green development efficiency (RGDE) based on Driving-Force, Pressure, State, Influence, Response (DPSIR) model and super-efficiency slacks-based measure (SBM) model. The results show that, the overall RGDE in China is fluctuating and rising from 1997 to 2017, and there are some differences between and within regions. The RGDE in developed areas is higher than that in developing areas, and coastal areas are higher than that in inland areas. The entire country, eastern, central, and western regions show σ convergence, which indicates that the RGDE is getting better, but there is no absolute β convergence, that means there is no “catch-up effect” between regions, but the gradient divergence showed central > eastern > western. At the same time, there is no conditional β convergence; the initial RGDE has a positive impact on the growth rate of RGDE, and the financial self-sufficiency rate promotes the growth of RGDE of the whole country and the western region, but inhibits the improvement of RGDE of the eastern region. The per capita GDP, mechanization degree, and agricultural industrial structure in rural areas did not promote the growth of RGDE. Based on the results, this paper puts forward some policy suggestions, such as promoting the classified implementation of rural green development policies, strengthening the top-level design, optimizing the existing agricultural mechanism and system, and guiding and standardizing the farmers’ green production behavior.
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