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[en] On the one hand energy, respectively electricity based on conventional and renewable, energy sources nationwide, are crucial for economic and social development. Considered globally, they are in continuous progress and the pace of their growth outpaced that of industry and other economic sectors. On the other hand the development of the energy sector in many cases creates problems associated with the environment, which become increasingly relevant, particularly with regard to global warming in recent decades. Subject of this report is an overview of the use of conventional and renewable energy sources concerning the safety and environmental impact. From this point of view is a brief overview is made on the main advantages and disadvantages of conventional power plants and power generation facilities based on solar, wind and biomass, which have high energy potential in Bulgaria. After analysis of selected basic principles of European and national legislation are presented the opportunities and dynamics of the use of various sources of energy in the country, now and in the larger time interval.
[en] Aim of the study: The aim of the study was to assess the seasonal dynamics of microbial biomass and its contribution to soil system along a fragment size gradient in subtropical humid forest of Meghalaya. Area of study: The study was conducted in forest fragments located at Jarain and adjoining areas in Jaintia Hills of Meghalaya, northeast India. Material and Methods: Forest fragments of sizes ranging from 3.8 to 105 ha were selected for the study and grouped into Small (< 5 ha), Medium (> 5 and < 15 ha), Large (>15 and < 50 ha) and Very Large (105 ha) classes. Three experimental plots each of 20 x 20 m were established at the forest edge and at 50 m distance assigned as ‘interior’ microsite in each of the fragments for sampling of soil. Soil samples (0-10 cm depth) from each of the experimental plots were collected in replicates on seasonal interval and microbial biomass was estimated by the fumigation extraction method. Important findings: Microbial biomass- C, -N and -P varied significantly (p< 0.05) between the fragment sizes, microsites and seasons. The microbial biomass was higher in the interior as compared to the edge. It was also high during the winter season. Overall, soil microbial biomass -C, -N and -P ranged from 260 to 969; 25 to 95 and 8 to 67 µg g-1 respectively. The contribution of microbial biomass -C, -N and -P to soil organic carbon, total Kjeldahl nitrogen and phosphorus ranged from 1.48 to 1.81 %, 2.54 to 4.54 % and 3.41 to 5.22 % respectively. Fragmentation alters the microenvironmental conditions and soil properties that in turn affect the microbial biomass. Highlights: This interaction of plant, soil and microbial community would gradually degrade in the fragments due to change in vegetation composition and structure, microclimatic conditions and soil physical and chemical properties. Our results suggests that microbial mediated ecosystem processes such as nutrient cycling are more susceptible to variation at the edge which may become unstable and unpredictable in forest fragments exposed to various human disturbances.
[en] Nitrogen concentration is an essential parameter in cyanobacterial cultures to produce enriched biomass with biotechnological purposes. Growth and biochemical composition of Nostoc LAUN0015, Nostoc UAM206, Anabaenasp.1 and Anabaena sp.2 were compared at 0, 4.25, 8.5 and 17 mM NaNO3. Cultures under laboratory conditions were maintained for 30 days at a volume of 500 mL. Anabaena sp.1 yielded the highest value of dry mass of 0.26 ± 2.49 mg mL-1 at 8.5 mM NaNO3. For chlorophyll, phycocyanin and phycoerythrins, maximum values were achieved at 17 mm NaNO3 with 18.09 ± 1.74, 102.90 ± 6.73 and 53.47 ± 2.40 ?g mL-1, respectively. Nostoc LAUN0015 produced its maximum value of protein 644.86 ± 19.77 mug mL-1, and 890 mg mL-1 of carbohydrates in the absence of nitrogen. This comparative study shows that the most efficient strain for the production of protein, carbohydrates and lipids in diazotrophic conditions corresponded to Nostoc LAUN0015. However, Anabaena sp.1 and Anabaena sp.2 required high nitrogen concentrations to achieve higher values of metabolites, comparing with Nostoc strains. Nitrogen dependence for the production of pigments and high protein production in strains of Anabaena and in diazotrophic conditions for Nostoc was demonstrated. Nostoc can be cultured under nitrogen deficiency and Anabaena in sufficiency, for biomass production enriched with proteins and carbohydrates.
[en] Highlights: • Raft-attaching green algae can be detected by NGRDI generated from UAV images. • An initial biomass estimation model of green algae in the South Yellow Sea based UAV and S2A Data was proposed. • Long-term initial biomass monitoring would provide a scientific basis for green tide control and forecast in the Yellow Sea. - Abstract: Previous studies have shown that the initial biomass of green tide was the green algae attaching to Pyropia aquaculture rafts in the Southern Yellow Sea. In this study, the green algae was identified with unmanned aerial vehicle (UAV), an biomass estimation model was proposed for green algae biomass in the radial sand ridge area based on Sentinel-2A image (S2A) and UAV images. The result showed that the green algae was detected highly accurately with the normalized green-red difference index (NGRDI); approximately 1340 tons and 700 tons of green algae were attached to rafts and raft ropes respectively, and the lower biomass might be the main cause for the smaller scale of green tide in 2017. In addition, UAV play an important role in raft-attaching green algae monitoring and long-term research of its biomass would provide a scientific basis for the control and forecast of green tide in the Yellow Sea.
[en] Mexico City Metropolitan Area (MCMA) is the most populated urban area in the country. In 2010, MCMA required 14.8% of total energy domestic demand, but greenhouse gas emissions accounted for 7.7% of domestic emissions. Mexico has massive renewable energy potential that could be harnessed through solar photovoltaic (PV) technology. The problem to explore is the relationship between local and federal public strategies in MCMA and their stance on energy transition concern, social empowerment, new technology appropriation, and the will to boost social development and urban sustainability. A public policy typology was conducted through instruments of State intervention approach, based on political agenda articulation and environmental local interactions. Social equality is encouraged by means of forthright funding and in-kind support and energy policies focus on non-renewable energy subsidies and electric transmission infrastructure investment. There is a lack of vision for using PV technology as a guiding axis for marginalized population development. It is essential to promote economic and political rearrangement in order to level and structure environmental governance. It is essential to understand people’s representation about their own needs along with renewable energy.
[en] Highlights: • Does the way models are developed affect their subsequent use in decision-making? • The iterative, collaboratively-developed model became a core tool for negotiations. • The consultation-based model was not used. • Collaborative model development helped build the model’s salience and credibility. - Abstract: While science matters for environmental management, creating science that is credible, salient to decision-makers, and deemed legitimate by stakeholders is challenging. Collaborative modeling is an increasingly-used approach to enable effective science-based decision-making. This work evaluates the modeling process conducted for two hydropower dam licensing negotiations, to explore how differences in the collaborative development of hydrological models affected differences in their use in subsequent decision-making. In one case, the model was developed iteratively through deliberation with stakeholders. Consequently, stakeholders understood the model and its limitations and trusted the model and modelers; the model itself was also better designed to evaluate resource managers’ questions. The collaboratively-developed model became the focal point for subsequent negotiations and enabled creative group problem-solving. Conversely, in the case with less engagement during model development, the model was not used subsequently by decision-makers. These differences are argued to result from trust built during the modeling process, applicability of the model to test real management scenarios, and the broader social context in which the models were used.
[en] Heavy metals (HMs) contamination of soils is a major problem occurring worldwide. Utility of energy crops for biofuel feedstock production systems offers a feasible solution for a commercial exploitation of an arable land contaminated with HMs. Experiments involved field testing of Miscanthus x giganteus and Spartina pectinata cultivated on HMs-contaminated soil with standard NPK fertilizers and commercially available microbial inoculum. Biomass yield, water content, macronutrients (N, P, K, Mg, Ca), and heavy metal (Cd, Pb, Zn) concentrations in plant shoots were assessed at the end of the first and the second growing season. Independently of the applied fertilizers, Miscanthus x giganteus produced higher biomass yield while contrary results were obtained for S. pectinata. Higher HMs content in plants influenced the status of the mineral macronutrients in particular N and K. Occurrence of hasted senescence induced by drought in the second growing season caused reduction in the concentrations of all elements (except Pb), due to earlier rhizomes relocation.
[en] Seaweeds are widely used as an alternate source of livelihood for coastal communities in different countries. Submerged habitats with nutrient-rich coastal waters along the Pakistan coast have rich algal stocks. With few exceptions, studies on seaweeds in Pakistan are mostly confined to intertidal areas. We have conducted preliminary surveys at Buleji, along the Karachi coast to access existing standing stocks of seaweeds. Samples were collected by SCUBA diving. Relative species abundances were determined using quadrat techniques. Overall, 17 species of macroalgae were recorded belonging to 2 major groups (Phaeophyceae 12, Rhodophyceae 5) and 6 families. Except diving site 6, the communities were dominated by Sargassum species. The majority of the recorded species had wide distribution ranges. Distribution patterns were mainly controlled by habitat type, depth, oceanographic conditions, and the nature of the sites. Many of the recorded species are commercially important. It is expected that further underwater surveys will help in exploring more algal beds along this coastline. A sustainable use of this algal biomass can provide an alternative source of income for coastal communities. Moreover, Pakistan has a long coastline with different geomorphic features; in this regard seaweed aquaculture in coastal areas especially near big cities can insert positive ecological impacts on coastal ecosystems as well as on the economic conditions of the coastal communities. (author)
[en] The global carbon budget is finite and dwindling. As the world moves to curb its addiction to fossil fuels, both consumption and supply are going to decline. Producing countries face an inflection point: do they embrace the inevitable and proactively manage the decline of the sector, or continue on a status quo trajectory? The former offers opportunities for leadership and innovation in defining the course for a post-carbon economy, while the latter threatens workers, communities, and finance that have become dependent on the fossil fuel-based economy.
[en] If in the 19th-century scientific knowledge moved from a generalist perspective to a growing specialization, in recent decades, problems that transcend disciplinary and political boundaries have required solutions based on interdisciplinary research and global actions, which led to the establishment of the Sustainable Development Goals (SDGs) in 2015. In the same perspective, studies on ecosystem services emerged as an area of transdisciplinary knowledge in rapid growth, while advances in the nuclear field enabled applications in industry, health, agriculture and the environment. Considering the development of these two spheres of knowledge, the objective of this study is to evaluate the correlation between the areas of Ecosystem Services and Nuclear Science and Technology, through category building and content analysis applied to articles listed in the Web of Science. From 1980 to June 2019, 22,751 records (article and review) were listed for the term ecosystem service*. When refining the result with the application of descriptors related to the nuclear area, correspondences were found for Uranium=13; Nuclear Power=6; Nuclear Energy=1; Nuclear technolog*=1; Nuclear fuel*=1; Nuclear material*=1, in a total of 23 correspondences only. On the other hand, the search using key descriptors of the nuclear area, plus the terms nature or ecosystem* or environment for the same period, totaled 9,328 papers (articles and reviews). While the NST is broadly convergent with SE, this correlation needs to be made more explicit in the studies, expanding the prospects for the conservation, preservation and recovery of the ecosystem services and their contribution to human wellbeing. (author)