خيارات البحث
النتائج 2511 - 2520 من 4,896
Games Strategy Study of Power Generation and Carbon Emission Rights Trading
2019
Kun Xiao and Jingdong Zhang
It is of great significance to reduce carbon emissions from electric power generation for green development. In addition to technical measures, two trading mechanisms are built to optimize China’s electric power generation: generation rights trading, and carbon emission rights trading. However, as the carbon emission rights trading are initiated, the issues of how to choose the right trading mechanism, and determining the appropriate strategy under the corresponding trading mechanism continue to confuse generation enterprises. In order to clarify these issues, the game theory was used to identify the proper trading strategies for generation enterprises under the two highly similar trade mechanisms. Results show that the two trading mechanisms are complementary to each other to some extent, and the generation enterprises should choose a proper trade strategy according to the endowment of generation prices, the technical abilities, the grid-loss price and the ratio of carbon-electricity conversion. The equilibrium solutions of trading scales and prices for the two trading mechanisms are mostly related to the endowments of generation prices. Generally, the buyers with higher endowments of generation prices should choose the carbon emission rights trading, and the buyers with lower endowments of generation prices can only benefit in generation rights trading. The bigger gaps between the endowments of generation prices of buyers and sellers are, the more likely the trade can be made and further result in a better environmental consequence. The conclusions provide suggestions to the government that, the grid-loss pricing and the ratio of carbon-electricity conversion could be used as key tools to regulate the market for both of the trade mechanisms.
اظهر المزيد [+] اقل [-]Effects of Flax Straw Biochar on Soil Properties, Fractions and Maize Availability of Lead and Cadmium in Light Sierozem
2019
Baowei Zhao, Renzhi Xu, Fengfeng Ma, Yewei Li and Lu Wang
Bioavailability of heavy metals can be reduced in acidic soils with biochar amendment but the situation in alkaline soils is not much clear. Effects of four rates (1%, 5%, 10% and 15% w/w) of flax (Linum usitatissimum L.) straw biochar (FBC) prepared at 600oC on the properties of soil, fraction and phytoavailability of Pb and Cd, and plant growth in the simulated Pb (1000 mg.kg-1) or Cd (20 mg.kg-1) contaminated light sierozem were assessed with pot experiments using maize (Zea mays L.) as an indicator plant. The amendment of FBC significantly enhanced the pH value, cationic exchange capacity (CEC) and organic matter of soil (P < 0.05). The BCR sequential extraction results indicated that the acid extractable fraction of Pb or Cd only decreased by 12.80% or 5.56% when FBC was added with the high rate of 15%. The uptake of Pb or Cd by maize shoots scarcely decreased with 1% and 5% of FBC amendment. Significant inhibitory effects of FBC on the growth of maize shoots were observed with FBC amendment at the rates of 10% and 15%. The results could provide a different implication for immobilization remediation of loess soils (e.g., light sierozem) contaminated with heavy metals.
اظهر المزيد [+] اقل [-]In-Situ Water Quality Improvement by Hypolimnion Oxygenation and Artificially Induced Mixing in a Drinking Water Reservoir
2019
Zhou Zi-zhen, Huang Ting-lin, Gong Wei-jin, Li Yang, Liu Yue, Zhao Fu-wang, Bai Yang, Dou Yan-yan, Lv Jing-jing and Liu Hai-fang
Faced with the problems of hypolimnion dissolved oxygen (DO) depletion and water quality deterioration, a newly designed water quality improvement technology named water-lifting aerators (WLAs) was put into utilization to solve these problems in Jinpen Reservoir. During the hypolimnion oxygenation period, after 20 days operation of 8 WLAs with compressed air volume of 10 m3/h, the thickness of anaerobic layer was compressed from 17 m to 3.2 m. As for artificially induced mixing, after 18 days operation of 8 WLAs with compressed air volume of 50 m3/h (full capacity), the reservoir was mixed, and DO of the bottom water increased to more than 8 mg/L. Removal rates of TN, TP, NH4-N and TOC reached 25.5%, 50%, 29.8% and 19.4% respectively. Results of Biolog method showed that the activity of microbes and carbon source utilization were improved in the water of the controlled area compared with the uncontrolled area during the operation. WLAs have been proved to be an efficient technology in water quality improvement especially in hypolimnion oxygenation and artificially induced mixing.
اظهر المزيد [+] اقل [-]Effect of Population Density and Surroundings on the Environmental RF Radiation
2019
Jagbir Kaur, A. K. Dhami and S. A. Khan
The cell-phone radiation is a potential health hazard not only to the singular user but to the whole population through the environmental pollution. The environmental radiation density may vary from place to place depending upon its absorption or reflection by surroundings, e.g., trees, buildings, human population, water bodies, etc. The present work was taken to study the effect of population density and surroundings on the environmental radiation. The power density values of radiation were measured using a hand-held portable power density meter TES 593, and specific absorption rates (SAR) were estimated from the measured values. The SAR values were compared with the safe limit of 1 mW/kg above which biological system of humans and animals starts getting affected. The studies indicated that the average environmental radiation power density values were higher in unpopulated and open areas than densely populated regions by 300%.
اظهر المزيد [+] اقل [-]Solar Thermal Pyrolysis of Karanja Seeds for a Sustainable Approach for Liquid Biofuel Utilization
2019
Surajit Mondal, Jitendra K. Pandey and Suresh Kumar
The present study is based on the conversion from biomass to biofuels of karanja (Pongamia glabra) seeds via solar thermochemical pyrolysis process. Karanja seeds were pyrolysed at a cavity type reactor temperature of 280-340°C. The pyrolysis process was occurring in the range of 210-550°C. The ultimate and proximate analysis of the pyrolysed bio-oil was performed based on ASTM standards. The FTIR (Fourier transform infrared spectroscopy) analysis of the liquid product indicated the presence of alkenes, alkanes, ketones, carboxylic acids and aromatic rings. GC-MS (gas chromatography-mass spectrometry) demonstrated the presence of hydrocarbons having between 15 and 34 carbon atoms in a chain.
اظهر المزيد [+] اقل [-]HPTLC Based Screening of -Sitosterol from Andrographis paniculata
2019
Rajeshwari Prabha Lahare and Anil Kumar
Sterols are secondary metabolites of plants known for their inhibitory effects on cancer cell growth, lower cholesterol and enhance immunity. b-sitosterol belongs to phytosterol which enhances antioxidant enzymes and thus reduces the oxidative stress. In present experiment, b-sitosterol was detected from Andrographis paniculata belonging to family Acanthaceae by using HPTLC. The plant is popularly known as Kalmegha having multiple pharmacological properties used for treatment of several diseases. Leaf, stem and root extracts prepared in chloroform, methanol and petroleum ether were used for detection of b-sitosterol from the plant. The chromatography was performed on TLC plates coated with Al silica gel 60 F254 and solvents used for mobile phase was toluene:ethyl acetate:formic acid (15:4.5:1.5). After development, the plates were derivatized with 10% methanolic sulphuric acid, scanned and quantified at 510 nm. The results showed the presence of b-sitosterol in all the parts with Rf value 0.62. Calibration curve was prepared and the amount of b-sitosterol was quantified in the extracts by comparing the respective peak areas with that of the standard. The correlation coefficient for b-sitosterol against reference sample was found significant (r= 99.769057%) for the concentration range of 0.5 to 4.0 µg. Leaf methanol extract showed the highest concentration of b-sitosterol, i.e., 147.6 µg/mL. The extraction efficiency of b-sitosterol was found higher in methanol followed by petroleum ether and chloroform extract. Thus, our finding shows that Andrographis paniculata has a significant concentration of b-sitosterol, which may be useful for pharmacological application against cancer, hypercholesterolemia, inflammation and for angiogenesis process.
اظهر المزيد [+] اقل [-]Effect of the Olive Mill Wastewater on Corrosion Behaviour of Carbon Steel
2019
Zineb Yahia, Mounir Ziati, Nabila Aissiou and Moussa Bounoughaz
Olive mill wastewater (OMW) is a major problem in the olive oil producing countries, because of its highly polluting power. Its physico-chemical characterization showed that this effluent has an acidic character (pH = 4.9) and it is rich in organic and mineral matter (chemical and biochemical oxygen demands, polyphenols, chlorides, sulphates, nitrites, nitrates, etc.). In this work, the corrosion behaviour of carbon steel (X70) immersed in olive mill wastewater sample solution, collected from an agro-industry, was studied. The obtained results show that the rate of corrosion increases because of the attack of acids exist in the OMW (Cl-, polyphenols, Ni, Fe). For two days of immersion, the potential stretches toward more positive values due to the oxidization of carbon steel. After the extension of the immersion until 7 days, we recorded the formation of the corrosion product on the surface of the working electrode. On the other hand, the analysis of surface samples by scanning electron microscope coupled with EDX confirms the formation of a layer obtained after the corrosion process.
اظهر المزيد [+] اقل [-]Factors Affecting Carbon Emissions in the Construction Industry based on STIRPAT Model: Taking Henan Province of China as an Example
2019
Jun Jie Peng
The construction industry of China is characterized by its huge consumption and carbon emissions, thereby making this industry one of the most important areas that require energy conservation efforts. Identifying those factors that affect carbon emissions in the construction industry carries great significance in reducing building carbon emissions, promoting low-carbon cities, and achieving China’s emission reduction goals. This paper firstly reviews the literature on those factors that affect the carbon emissions in the construction industries of developed countries. Second, by using Henan Province as an example, those factors that influence carbon emissions are measured by using the classical STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology) model. Third, some measures for reducing carbon emissions in the construction industry are developed. Those factors that influence the carbon emissions of buildings are multi-dimensional and diversified. Resident population, urbanization rate, building carbon emission intensity, per capita GDP (Gross Domestic Product), and per capita added value of the tertiary industry all have significant effects on the carbon emissions of buildings in Henan Province. Some policy suggestions can be derived from the findings of this work, such as encouraging building energy conservation, improving the energy efficiency of the construction industry, adjusting the use of building materials, and improving the extant policies for building emission reduction. The results also provide a theoretical basis for identifying those factors that affect the carbon emissions in the construction industry and for formulating and implementing strategies for the low-carbon development of this industry.
اظهر المزيد [+] اقل [-]Application of Geospatial Technology in Evaluating the Impact of Mining Associated Urbanization on Agricultural Lands
2019
M. Prasad, Y. Sudharshan Reddy, E. Balaji, V. Sunitha and M. Ramakrishna Reddy
In this study an attempt was made to assess the mining associated urbanization impact on rural agricultural lands due to expansion of mining dump yards, pulverizing mills and beneficiation plants in and around Govindampalle village, YSR District, A.P by using Geospatial technologies. Various land use and land cover (LULC) classes, mainly, cropland, plantation, fallow land, mining/industrial, water body, settlements and scrub lands were recognized and their impact on the environment has been discussed. Google earth historical imagery during 2010 and 2017 are used to map and assess these land use and land cover changes in the ArcGIS flat form. LULC change detection analysis data showed that cropland, water bodies and scrublands were decreased by 10, 2, 14 and 20 percent, respectively from 2010 to 2017. On the other hand industrial areas and agricultural plantations showed an increasing trend with 14 and 20 percent growth rate respectively.
اظهر المزيد [+] اقل [-]Modelling of Chlorophyll-a Concentration Patterns from Satellite Data Using Cubic Spline Function in Pattani Bay, Thailand
2019
Pratistha Sharma, Attachai Ueranantasun†, Phattrawan Tongkumchum and Mayuening Eso
The modelling of chlorophyll-a concentration helps to restrict the harmful effects in marine species caused by increased nutrient loads. The derived satellite data are often used for the monitoring of marine ecology. The common usage of satellite data is monthly average data to avoid the problem of missing values. In order to reduce the effect of missing data, this study employed the cubic spline model by using a satellite data for investigating seasonal variations of chlorophyll-a mapped in an eight-day interval consisting of missing values in Pattani Bay, Thailand from the year 2003 to 2017. This study further used the spline-fitted data for creating the baseline model of chlorophyll-a in Pattani Bay, and for examining the difference between spline fitted and monthly average data. This study revealed that the cubic spline method was able to handle the missing values in satellite data to gain the smoothness in data. When both models were compared, the spline-fitted observation yielded a smoother curve pattern than the monthly average observation. The spline fitted model was also able to display the chlorophyll-a data at any particular day of the year. It was also shown that the chlorophyll-a concentration level in the coastal area of Pattani Bay was higher in the inshore pixels, especially in rainy season.
اظهر المزيد [+] اقل [-]