3,089 research outputs found
Techno-Economic Assessment of a Biomass-Based Cogeneration Plant with CO2 Capture and Storage
Reduction of CO2 emissions from energy systems could be achieved through: CO2 capture and storage, energy savings, fuel switching among fossil fuels, increased use of renewable energy sources, and nuclear power. In addition, atmospheric CO2 reduction could also be achieved through increasing the carbon stock in soils and standing biomass. The CO2 capture and storage option for mitigating CO2 emissions from biomass-based cogeneration plants, considering critical aspects such future development of technologies, economies of scale. carbon price, site-specific analysis, and future energy systems has received little attention in scientific studies. With the overall objective of improved understanding of the potential scope for its large-scale implementation, a techno-economic assessment of biomass-based cogeneration plants with CO2 capture and storage was carried out. Most of the above-mentioned critical aspects have been considered for the techno-economic assessment of cogeneration plants with CO2 capture and storage technology.
The results show the optimal scale of the conversion systems with respect to cost of electricity (COE). The optimal size for steam turbine-based cogeneration (CHP-ST) technologies without CO2 capture lies in the range 98-106 MWe (COE is 5.7 USD/MWh) when fueled by forest/logging residues, but the optimal size increases to 200-227 MWe for integrated gasification combined cycle based cogeneration (CHP-IGCC) (COE is 16.73 USD/MWh). The optimal size increases considerably to 249-288 MWe (COE 15.70 USD/MWh) for Salix fueled CHP-ST technology without CO2 capture and 441-504 MWe (COE 27.52 USD/MWh) for CHP-IGCC technology. With the additional feature of CO2 capture, transport, and storage (here we assume 100 km CO2 transport distance from the plant site) the unit capital cost for CHP-ST and CHP-IGCC technology increases around 70 and 30 percent, respectively.
If one considers revenues from trading emission quotas earned through negative emissions one can estimate a market price of CO2 (PC) at which the COE becomes negative (i.e. all capital and operating costs are covered by revenues from heat and negative emissions delivered). Scale effects significantly influence the economic feasibility of CO2 capture. According to the model calculation, the PC at which the COE becomes negative significantly drops from 75 USD/tCO2 for 10 MWe CHP-ST plants to 32 USD/tCO2 for 90 MWe CHP-ST plants when fueled by Salix. The PC drop from 65 USD/tCO2 for 10 MWe CHP-ST plants to 25 USD/tCO2 for 90 MWe CHP-ST plants when fueled by forest/logging residues. For CHP-IGCC plants, the PC decreases from 72.5 USD/tCO2 for 30 MWe to 37.5 USD/tCO2 for 170 MWe when fueled by Salix. When fueled by forest/logging residue, the PC decreases from 62.5 USD/tCO2 for 30 MWe plants to 30 USD/tCO2 for 170 MWe.
The techno-economic assessment was based on electrical capacity of the plants and revenues from cogenerated heat and captured CO2 were credited. In practice, the implementation of any cogeneration should be optimized based on site-specific context
Participatory rural appraisal approaches: an overview and an exemplary application of focus group discussion in climate change adaptation and mitigation strategies
Different tools and techniques of participatory approaches are the basic way of conducting qualitative research especially in the field of applied social science. Focus Group Discussion (FGD) is one of the main Participatory Rural Appraisal (PRA) technique often used in combination with others to achieve desired goals. Considering this concept, this paper attempts to review the PRA approach and then application of FGD, in combination with matrix scoring and ranking to identify problems and causes of climate change along with possible mitigation and adaptation strategies. A group of 20 students at post graduate level under the faculty of Agriculture and Horticulture at Humboldt University of Berlin, Germany those from different corner of the world was considered as target people of the study. The results concluded that unpredictable weather events was ranked as the present outstanding visible climate change problem caused by human activities. However, it was noted that if alternative renewable energy sources are exploited, this could contribute to solving the present climate change problem. This finding might have the good reference for the policy makers in the same line not only for developing countries but also for developed countries. DOI: http://dx.doi.org/10.3329/ijarit.v3i2.17848 Int. J. Agril. Res. Innov. & Tech. 3 (2): 72-78, December, 201
Formation of a rotating jet during the filament eruption on 10-11 April 2013
We analyze multi-wavelength and multi-viewpoint observations of a helically
twisted plasma jet formed during a confined filament eruption on 10-11 April
2013. Given a rather large scale event with its high spatial and temporal
resolution observations, it allows us to clearly understand some new physical
details about the formation and triggering mechanism of twisting jet. We
identify a pre-existing flux rope associated with a sinistral filament, which
was observed several days before the event. The confined eruption of the
filament within a null point topology, also known as an Eiffel tower (or
inverted-Y) magnetic field configuration results in the formation of a twisted
jet after the magnetic reconnection near a null point. The sign of helicity in
the jet is found to be the same as that of the sign of helicity in the
filament. Untwisting motion of the reconnected magnetic field lines gives rise
to the accelerating plasma along the jet axis. The event clearly shows the
twist injection from the pre-eruptive magnetic field to the jet.Comment: 14 pages, 12 figures, to appear in MNRA
Role of non-timber forest products in sustaining forest-based livelihoods and rural households' resilience capacity in and around protected area- a Bangladesh study
People in developing world derive a significant part of their livelihoods
from various forest products, particularly non-timber forest products. This
article attempts to explore the contribution of NTFPs in sustaining
forest-based rural livelihood in and around a protected area of Bangladesh, and
their potential role in enhancing households resilience capacity. Based on
empirical investigation our study revealed that, local communities gather a
substantial amount of NTFPs from national park despite the official
restrictions. 27 percent households of the area received at least some cash
benefit from the collection, processing and selling of NTFPs, and NTFPs
contribute as HHs primary, supplementary and emergency sources of income. NTFPs
also constituted an estimated 19 percent of HHs net annual income, and were the
primary occupation for about 18 percent of the HHs. HHs dependency on nearby
forests for various NTFPs varied vis-a-vis their socio-economic condition as
well as with their location from the park. Based on our case study the article
also offers some clues for improving the situation in PA.Comment: To appear in Journal of Environmental Planning and Management, 201
Islamic Banking and Green Banking for Sustainable Development: Evidence From Bangladesh
Green banking is an integral part of Islamic banking that makes a basis of environmental protection. This study attempts to examine the relationship between Islamic banking and green banking that contribute to sustainable development. The study has used the primary data through a structural questionnaire that includes various dimensions on green banking of Islamic banking in Bangladesh. The investigation revealed that Islamic banks had made a significant contribution to green banking that improves the environment as means of cost and energy savings, preservation of natural resources and the need to respect all living things. The study seems to carry an enormous academic value since a few studies have undertaken in this areaDOI: 10.15408/aiq.v10i1.456
Arsenite-Induced Alterations of DNA Photodamage Repair and Apoptosis After Solar-Simulation UVR in Mouse Keratinocytes in Vitro
Our laboratory has shown that arsenite markedly increased the cancer rate caused by solar-simulation ultraviolet radiation (UVR) in the hairless mouse skin model. In the present study, we investigated how arsenite affected DNA photodamage repair and apoptosis after solar-simulation UVR in the mouse keratinocyte cell line 291.03C. The keratinocytes were treated with different concentrations of sodium arsenite (0.0, 2.5, 5.0 μM) for 24 hr and then were immediately irradiated with a single dose of 0.30 kJ/m(2) UVR. At 24 hr after UVR, DNA photoproducts [cyclobutane pyrimidine dimers (CPDs) and 6–4 photoproducts (6-4PPs)] and apoptosis were measured using the enzyme-linked immunosorbent assay and the two-color TUNEL (terminal deoxynucleotide transferase dUTP nick end labeling) assay, respectively. The results showed that arsenite reduced the repair rate of 6-4PPs by about a factor of 2 at 5.0 μM and had no effect at 2.5 μM. UVR-induced apoptosis at 24 hr was decreased by 22.64% at 2.5 μM arsenite and by 61.90% at 5.0 μM arsenite. Arsenite decreased the UVR-induced caspase-3/7 activity in parallel with the inhibition of apoptosis. Colony survival assays of the 291.03C cells demonstrate a median lethal concentration (LC(50)) of arsenite of 0.9 μM and a median lethal dose (LD(50)) of UVR of 0.05 kJ/m(2). If the present results are applicable in vivo, inhibition of UVR-induced apoptosis may contribute to arsenite’s enhancement of UVR-induced skin carcinogenesis
Independent higher education educators in England: Tutors behavioural characteristics preferred by mature students on business management courses
This research study focuses on identifying the behavioral characteristics desired by mature students from their educators/lecturers/tutors in an Independent Higher Education provider within the UK. The study utilises a mixed-method approach, employing a nonexperimental and sequential explanatory design consisting of two phases. The first phase involves a questionnaire survey, while the second phase comprises semi-structured interviews with the students, aiming to gather both detailed and general insights into the students’ perspectives on the expected behavioral characteristics of their educators. The findings of this study reveal both commonalities and differences in the attributes of lecturers as identified in the quantitative and qualitative findings. In both sets of findings, it is evident that students prefer personalised learning experiences, with an emphasis on lecturers recognising their unique strengths, valuing individuality and providing positive feedback. Additionally, the qualitative findings highlight the significance of patience, empathy, and problem-centered teaching as highly valued traits of a lecturer according to the students. This research contributes to the existing body of knowledge by addressing the complexities involved in educating mature students within the UK Higher Education sector. It emphasises the importance for Higher Education practitioners to comprehend the expected behavioral characteristics of these mature students from their educators. The study also highlights the scarcity of research in this area, as existing literature on adult education and andragogy is often generic and independent of specific contexts
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