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Efficiency of a solar collector system for the public building depending on its location Полный текст
2020
Krawczyk, Dorota Anna | Żukowski, Mirosław | Rodero Franganillo, Antonio
Due to a technologic progress, a growth in the renewable energy markets including a high number of manufactures coming to being, the Renewable Energy Sources (RES) are both a tool for mitigating climate changes and investments that can provide direct economic profits and reduce a political or economic dependence resulting from import of fossil fuels. One of the many key solutions toward fulfilling the global increasing demand for energy and reduction of CO₂ emissions is applying solar technologies. This paper presents the results of the analysis conducted for a small public office building located in Bialystok (Poland), where solar collectors were considered as the RES for domestic hot water (DHW) system, on the understanding that existing oil boiler would be an additional source. Low values of recommended water consumption in office buildings resulted in a low energy demand. However, concerning a potential of all office governmental buildings in Poland, it would be possible to reduce CO₂ emission by 17,248 tonnes. In the comprehensive analysis, the same building in two more locations (Cordoba (Spain) and Kaunas (Lithuania)) was considered using simulation tools delivered within the framework of VIPSKILLS project as well as EnegyPlus software. The results allow to compare the mean monthly efficiency of systems or number of collectors necessary to deliver similar amount of solar energy.
Показать больше [+] Меньше [-]Modulatory role of dietary Thymus vulgaris essential oil and Bacillus subtilis against thiamethoxam-induced hepatorenal damage, oxidative stress, and immunotoxicity in African catfish (Clarias garipenus) Полный текст
2020
El Euony, Omnia I. | Elblehi, Samar S. | Abdel-Latif, Hany M. | Abdel-Daim, Mohamed M. | El-Sayed, Yasser S.
Thiamethoxam (TMX) is a widely used neonicotinoid insecticide for its effective potential for controlling insects from the agricultural field, which might induce toxicity to the aquatic biota. In this study, the role of the probiotic Bacillus subtilis (BS) and a phytogenic oil extract of Thymus vulgaris essential oil (TVEO) in the modulation of thiamethoxam (TMX)-induced hepatorenal damage, oxidative stress, and immunotoxicity in African catfish (Clarias garipenus) has been evaluated. Fish were subjected to TMX (5 mg L⁻¹) and fed with a diet either supplemented with BS (1000 ppm) or TVEO (500 ppm). The experiment lasted for 1 month. By the end of the experiment, blood was sampled for biochemical analysis and fish organs and tissues were collected for histopathological and immunohistochemical examinations. Results showed a substantial increase of serum markers of hepatorenal damage such as the activities of aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) and levels of blood urea nitrogen (BUN) and creatinine with an obvious decrease of serum protein levels in the TMX-intoxicated group. Also, there was a considerable increase in malondialdehyde (MDA) levels and glutathione-S-transferase (GST) activity. TMX remarkably suppressed serum lysozyme activity, respiratory burst activity, and phagocytosis with a conspicuous elevation of the levels of interleukins (interleukin-1 beta (IL-1β) and interleukin-6 IL-6). The histopathological findings showed that TMX induced degenerative changes and necrosis in the gills, liver, head kidneys, and spleen of the intoxicated fish. Significant alterations of frequency, size, and area percentage of melanomacrophage centers (MMCs), decreased splenocyte proliferation, and increased number of caspase-3 immunopositive cells were also observed. Contrariwise, the concurrent supplementation of either BS or TVEO in the diets of catfish partially mitigated both the histopathological and histomorphometric lesions of the examined tissues. Correspondingly, they improved the counts of proliferating cell nuclear antigen (PCNA) and caspase-3 immunopositive splenocytes. In conclusion, the co-administration of either BS or TVEO in catfish diets partially diminished the toxic impacts of TMX. Nonetheless, the inclusion of TVEO in the diets of catfish elicited better protection than BS against TMX-induced toxicity in response to its potential anti-inflammatory, antioxidant, anti-apoptotic, and immune-stimulant effects.
Показать больше [+] Меньше [-]Evaluation of groundwater sustainable development considering seawater intrusion in Beihai City, China Полный текст
2020
Ma, Chuangming | Li, Yonggang | Li, Xuan | Gao, Lin
The overmining of groundwater makes the aquifer in a coastal area prone to seawater intrusion and further leads to deterioration of water quality and ecosystem degradation. However, the vulnerability evaluation of seawater intrusion can provide a scientific basis for the prevention of seawater intrusion, and then ensure the sustainable use of groundwater. In this paper, Baihai City was taken as the study area, and the analytic hierarchy process (AHP), variable power theory, and fuzzy comprehensive evaluation method were used synthetically. The vulnerability of seawater intrusion in the study area was divided into lowest vulnerability, low vulnerability, medium vulnerability, and high vulnerability, and these correspond to 1739.98, 133.88, 664.32, and 737.55 km². On this basis, combined with the groundwater quality and quantity and ecosystem of the study area, the groundwater is divided into concentrated groundwater supply area (8.16%), decentralized groundwater supply area (12.44%), protected area (78.94%), and reserved zone (0.45%), which can provide the basis for the rational exploitation and management of groundwater. By analyzing the results of constant right and variable weight evaluation, combined with the history of seawater intrusion, it is proved that the variable weight evaluation model can effectively solve the unreasonable situation caused by the internal differences of the indicator, so that the evaluation results are more in line with reality. In addition, the application of the fuzzy comprehensive evaluation method makes the evaluation results clearer.
Показать больше [+] Меньше [-]Research on the relationship between energy consumption and air quality in the Yangtze River Delta of China: an empirical analysis based on 20 sample cities Полный текст
2020
He, Lingyun | Yin, Fang | Wang, Deqing | Yang, Xiaolei | Xie, Fengmin
This paper uses static and dynamic panel regression to measure the effect of energy consumption on air quality of 20 heavily polluted cities in the Yangtze River Delta of China. Further, the influence of the relevant policies on the relationship between energy consumption and air quality is tested with the method of regression discontinuity. This study concluded the following: (1) When energy consumption structure, industrial structure, and energy efficiency are taken into account, the effect coefficient of energy consumption on air quality is 0.4579, meaning that controlling energy consumption tends to improve the air quality positively. (2) The emission of sulfur dioxide is characterized by inertia; the annual increase in sulfur dioxide emissions in the previous year will lead to an increase of 0.427% in the annual emissions. (3) The relationship between energy consumption and air quality of different cities varies, and these cities can be divided into four categories. (4) The relevant policies for improving air quality are effective to some extent. This study indicates that the Yangtze River Delta should focus on actively changing the mode of energy development.
Показать больше [+] Меньше [-]Impact of environmental contaminants on reproductive health of male domestic ruminants: a review Полный текст
2020
Guvvala, Pushpa Rani | Ravindra, Janivara Parameswaraiah | Selvaraju, Sellappan
Environmental contaminants are gaining more attention in the livestock sector lately due to their harmful effects on productivity and fertility of livestock. Recent research indicates that many domestic ruminants are becoming subfertile/infertile due to confounding reasons associated with management. Contaminants like metals, metalloids, herbicides, pesticides, insecticides, chemicals, or natural contaminants are present everywhere in day to day life and are becoming a threat to the livestock. Studies on a broad-spectrum of animals suggest that high doses of acute or low doses of chronic exposure to the contaminants lead to disruption of multi-organs/systems including reproductive function. The lowered reproductive efficiency in animals is attributed to the endocrine disruptor activities of the environmental contaminants on the gonads, affecting gametogenesis and steroidogenesis. In vitro studies on testicular cells and the semen suggest that spermatozoa are more susceptible to damage by environmental contaminants. The quality of the semen happens to be a critical factor in the livestock industry. Contaminants affecting gametogenesis and steroidogenesis may lead to devastating consequences to the livestock reproduction, and thus the production. However, there is a lack of collective data on the effect of such environmental contaminants on the fertility of male domestic ruminants. This review discusses the studies related to the impact of environmental contaminants on male fertility in large (bull and buffalo) and small (sheep and goat) ruminants by focusing on the underlying molecular interactions between the contaminants and gonads.
Показать больше [+] Меньше [-]The relationship between climate change and political instability: the case of MENA countries (1985:01–2016:12) Полный текст
2020
Sofuoğlu, Emrah | Ay, Ahmet
The aim of this study is to examine the relationship between climate change and political instability in the MENA region. To this extent, 18 Middle East and North African (MENA) countries are analyzed covering the period 1985:01–2016:12 with monthly data. In econometric analysis, at first cross-sectional dependency analysis is applied, and existence of cross-sectional dependency among countries is found. Therefore, CADF-second generation panel unit root test applied, and finally, Dumitrescu and Hurlin (2012) panel causality test that consider the cross-sectional dependency are utilized. For empirical analysis, temperature and precipitation data representing climate change, political instability, and conflict data are employed. According to the findings, there is a causal relationship from climate change to political instability in 16 countries and to conflict in 15 countries. In addition to this, at least one causal relationship is determined from climate change to political instability or conflict in all MENA countries. Therefore, empirical results support the assumption that climate change acts as a threat multiplier in MENA countries since it triggers, accelerates, and deepens the current instabilities.
Показать больше [+] Меньше [-]Protective effects of dietary mannan oligosaccharide on heat stress–induced hepatic damage in broilers Полный текст
2020
Chen, Yueping | Cheng, Yefei | Wen, Zhao | Zhou, Yanmin
Heat stress is a major concern in broiler’s production, which can damage liver of broilers. This study investigated the protective effects of mannan oligosaccharide (MOS) on heat stress–induced hepatic injury in broilers. A total of 144 day-old male chicks were allocated into three treatment groups. Broilers raised under normal ambient temperature were fed a basal diet (control group), and broilers under heat stress (32–33 °C for 8 h daily) were given the basal diet supplemented without MOS (heat stress group) or with 1 g/kg MOS (MOS group) for 42 days. Compared with the control group, heat stress reduced liver weight, whereas increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in the serum. It also reduced glutathione peroxidase (GSH-Px) activity in the serum and liver, GSH content, and superoxide dismutase (SOD) activity in the liver, but increased malondialdehyde (MDA) concentration in the serum and liver. Dietary MOS decreased serum ALT activity in heat-stressed broilers. MOS inclusion also decreased serum MDA content, but elevated hepatic GSH-Px and SOD activities, with MDA content and GSH-Px activity still being different from the control group, and SOD activity being similar to the control group. Heat stress increased concentrations of tumor necrosis factor α (TNF-α) in the serum and liver, interleukin-1β (IL-1β) in the liver, and mRNA abundances of HSP70, TLR4, MyD88, TNF-α, and IL-1β in the liver of broilers. Serum TNF-α content and mRNA abundances of hepatic TLR4 and TNF-α in MOS group were lower than the heat stress group, whereas these indexes were still higher than the control group. Our results indicated that dietary MOS ameliorated hepatic damage in heat-stressed broilers through alleviation of oxidative stress and inflammation.
Показать больше [+] Меньше [-]Tanning process promotes abiotic humification: separation and characterization of humic acid-like polymers complex Полный текст
2020
Zhu, Chao | Wang, Huiqin | Ma, Hongrui | Yang, Yonglin | Li, Fan
Humic-like substances are essential components of soluble organic matter in tannery wastewater. However, the tannery process can promote the abiotic humification in wastewater. Therefore, it is of great significance to clarify the pathway and degree of abiotic humification and the properties of the as-derived humic acid-like (HAL) complex polymers in the tannery process in order to control the refractory organic compounds. In the present study, considering the catechol-Maillard system and commercial humic acid (HA) as control, the polyphenol-Maillard humification in the tannery process was simulated under the catalysis of MnO₂. Moreover, physicochemical and spectroscopic techniques were used to characterize the separated fractions of HAL further. As a result, it was found that the catechol-Maillard system with small molecule organic matter as precursor had higher humification degree. Furthermore, the ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), and excitation-emission matrix (EEM) fluorescence spectrum of humic acid-like 0 (HAL0) derived from it was different from those of humic acid-like 1 and 2 (HAL1 and HAL2) of polyphenol-Maillard system, indicating the differences of polymer structure between them. In the polyphenol-Maillard system, tannin was the skeleton of polymerization or polycondensation reaction, and the high content of N and the H/C value of HAL2 indicated that in adding to amino acids, proteins promoted the humification, forming industry-specific HAL polymers with a high degree of aliphatic nature. Therefore, it can be concluded that controlling the raw materials in the tannery process (especially tannins), in order to reduce the occurrence of abiotic humification may be the key to improve the efficiency of wastewater treatment.
Показать больше [+] Меньше [-]Toxicity of the herbicide flurochloridone to the aquatic plants Ceratophyllum demersum and Lemna minor Полный текст
2020
Zhou, Jianan | Wu, Zhonghua | Yu, Dan | Yang, Lu
As a new and efficient selective pre-emergence herbicide, flurochloridone (FLC) has been widely promoted in recent years but readily results in residues in nature. As the primary producers and restorers of the water environment, aquatic plants are at risk of FLC exposure. In the present research, we studied the phytotoxicity of FLC in Lemna minor and Ceratophyllum demersum. The physiological and growth responses of these two aquatic plants exposed to different concentrations of FLC (0, 20, 100, 300, 1000, and 2000 μg/L) were measured. The results showed that FLC (≥ 20 μg/L) could cause serious photosynthesis pigment damage and bleaching in C. demersum and L. minor. Significant oxidative damage was observed in L. minor at 20 μg/L FLC, while there was no severe oxidative damage in C. demersum. At 100–300 μg/L FLC, peroxidase (POD) and superoxide dismutase (SOD) were activated to scavenge free radicals in L. minor, while POD acted as a protective enzyme in C. demersum. At higher concentrations of FLC (≥ 1000–2000 μg/L), L. minor reached less than healthy stability through the regulation of the antioxidant enzyme system and the chlorophyll a/b value. POD, SOD, and protein content returned to normal levels, and the growth parameters increased. However, in C. demersum, the enzymes POD and SOD and soluble protein were damaged, and oxidative stress reached the highest level at 1000–2000 μg/L FLC. Taken together, our results suggested that when treated with FLC, L. minor was more sensitive at lower doses (20 μg/L) and more adaptive at higher doses (1000–2000 μg/L) than C. demersum.
Показать больше [+] Меньше [-]Qualitative and quantitative analysis of the relationship between water pollution and economic growth: a case study in Nansi Lake catchment, China Полный текст
2020
Liu, Yi | Yang, Liyuan | Jiang, Wei
Investigation of water pollution–economic growth nexus is an important component for the sustainable development of eco-environment and socio-economy. This study combined the improved Grey relational degree (GRD) model with the environmental Kuznets curve (EKC) to quantitatively and qualitatively investigate the relationships between water pollution and economic growth in Nansi Lake catchment (Jining, Zaozhuang, and Heze) under the context of the Five-Year Plan in Shandong. Results showed that the relational degree of industrial wastewater and economic growth was Heze (0.652) > Zaozhuang (0.581) > Jining (0.538), and of domestic wastewater and economic growth was Jining (0.722) > Heze (0.721) > Zaozhuang (0.650). Meanwhile, the EKC of industrial wastewater rose and then declined, whereas that of domestic wastewater increased upwards. Overall, coordinated development had been gradually obtained between industrial wastewater emissions and economic growth. And, uncoordinated development between domestic wastewater emissions and economic growth still existed, indeed, in recent years it had intensified. Further, domestic wastewater emissions continue to rise, to the point where they now constitute one of the main sources of water pollution in Nansi Lake catchment. Results of this study indicated that combining the improved GRD model with the EKC provides a new approach to comprehensive investigation of the water pollution–economic growth nexus from a qualitative and quantitative perspective.
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