1,106 research outputs found
Heterogeneity Index of Trade and Actual Heterogeneity Index - the case of maximum residue levels (MRLs) for pesticides
Second Round Of Studies On Advanced Power Generation Based On Combined Cycle Using A Single High-pressure Fluidized Bed Boiler And Consuming Biomass
Following a preliminary study of power generation processes consuming sugar-cane bagasse; this second round indicates the possibility of almost doubling the current efficiency presently obtained in conventional mills. A combined cycle uses highly pressurized fluidized bed boiler to provide steam above critical temperature to drive steam-turbine cycle while the flue-gas is injected into gas turbines. The present round also shows that gains over usual BIG/GT (Biomass In-tegrated Gasification/Gas Turbine) are very likely mainly due to the practicality of feeding the biomass as slurry that can be pumped into the pressurized boiler chamber. Such would avoid the cumbersome cascade feeding of the fibrous bio-mass, usually required by other processes. The present stage assumes slurry with 50% added water. Future works will concentrate on thicker slurries, if those could be achieved. All studies apply a comprehensive simulator for boilers and gasifiers [CSFMB© or CeSFaMB™] and a process simulator (IPES) to predict the main features of the steam and gas tur-bine branches. © Souza-Santos and Chávez.614147Williams, R.H., Biomass Gasifier/Gas Turbine Power and Green-house Warming (1989) IEA/OECD Expert Seminar on Energy Tech-nologies for Reducing Emissions of Greenhouse Gases, OECD Headquarters, , Paris, 12th-14th AprilOgden, J.M., Williams, R.H., Fulmer, M.E., Cogeneration Applications of Biomass Gasifier/Gas Turbine Technologies in the Cane Sugar and Alcohol Industries (1990) Conference on Energy and Environment in the 21st Century, Massachusetts Institute of Tech-nology, , March 26-28, Cambridge, MALarson, E.D., Biomass-Gasifier/Gas-Turbine Cogeneration in the Pulp and Paper Industry (1991) 36th ASME International Gas Turbine and Aeroengine Congress and Exhibition, , June 3-6, Orlando, FloridaLarson, E.D., Marrison, C.I., Economic Scales for First-Generation Biomass-Gasifier/Gas Turbine Combined Cycles Fu-eled from Energy Plantations (1996) Turbo Expo' 96, the 41st ASME Gas Turbine and Aeroderivative Congress, , 10-13 June, Birming-ham, EnglandLarson, E.D., Hughes, W.E.M., (1996) Performance modeling of aeroderivative steam-injected gas turbines and combined cycles Fueled from Fixed or Fluid-bed Biomass Gasifiers, , Turbo expo'96, the 41st asme gas turbine and aeroengine congress, 10-13 June, Birmingham, EnglandConsonni, S., Larson, E.D., Biomass-gasifier/aeroderivative gas turbine combined cyclespart a: Technologies and performance modeling (1994) 8th congress & exposition on gas turbines in cogeneration and utility, industrial and independent power genera-tion, , Cogen turbo power'94, the american society of me-chanical engineers', Portland, Oregon, 25-27 OctoberConsonni, S., Larson, E.D., Biomass-Gasifier/Aeroderivative Gas Turbine Combined CyclesPart B: Performance Calculations and Economic Assessment (1994) Cogen turbo power'94, the American society of mechanical engineers' 8th congress & exposition on gas turbines in cogeneration and utility, industrial and independent power generation, , 25-27 October, Portland, OregonLarson, E.D., Williams, R.H., Leal, M.R.L.V., A review of bio-mass integrated-gasifier/gas turbine combined cycle technology and its application in sugarcane industries, with an analysis for Cuba (2001) Energy Sustainable Development, 5 (1). , MarchOakey, J., Simms, N., Kilgallon, P., Gas turbines: Gas cleaning requirements for biomass-fired systems (2004) Materials Research, 7 (1), pp. 17-25de Souza-Santos, M.L., (2010) Solid Fuels Combustion and Gasification: Modeling, Simulation, and Equipment Operation, , 2nd ed. CRC Press: New York, NY, USAde Souza-Santos, M.L., (2004) Solid Fuels Combustion and Gasifica-tion: Modeling, Simulation, and Equipment Operation, , Marcel Dekker: New York, NY, USAde Souza-Santos, M.L., A Study on Pressurized Fluidized-Bed Gasification of Biomass through the Use of Comprehensive Simula-tion (1998) Combustion Technologies for a Clean Environment, 4. , Gordon and Breach Publishers: Amsterdam, Hollandde Souza-Santos, M.L., (1987) Modelling and Simulation of Fluid-ized-Bed Boilers and Gasifiers for Carbonaceous Solids, , Ph.D. Thesis presented at the University of Sheffield, Department of Chemical Engineer and Fuel Technology, England, United King-dom, Julyde Souza-Santos, M.L., Comprehensive Modelling and Simulation of Fluidized-Bed Boilers and Gasifiers (1989) Fuel, 68, pp. 1507-1521de Souza-Santos, M.L., Application of Comprehensive Simulation to Pressurized Fluidized Bed Hydroretorting of Shale (1994) Fuel, 73, pp. 1459-1465de Souza-Santos, M.L., Application of Comprehensive Simulation of Fluidized-Bed Reactors to the Pressurized Gasification of Bio-mass (1994) Journal of the Brazilian Society of Mechanical Sciences, 16, pp. 376-383de Souza-Santos, M.L., A Study on Thermo-chemically Recuper-ated Power Generation Systems Using Natural Gas (1997) Fuel, 76, pp. 593-601de Souza-Santos, M.L., A Feasibility Study on an Alternative Power Generation System Based on Biomass Gasification/Gas Turbine Concept (1999) Fuel, 78, pp. 529-538Costa, A.M.S., de Souza-Santos, M.L., Studies on the mathe-matical modeling of circulation rate of particles in bubbling fluid-ized beds (1999) Powder Technology, 103, pp. 110-116de Souza-Santos, M.L., Two trial models for the rate of combus-tion and gasification of liquid fuels sprayed on inert fluidized parti-cles (2001) Sixth International Conference on Technologies and Com-bustion for a Clean Environment, , 9-12 July, Porto, PortugalRabi, J.A., de Souza-Santos, M.L., Incorporation of a two-flux model for radiative heat transfer in a comprehensive fluidized bed simulator. Part I: Preliminary theoretical investigations (2003) Thermal Engineering, 3, pp. 64-70Rabi, J.A., de Souza-Santos, M.L., Incorporation of a two-flux model for radiative heat transfer in a comprehensive fluidized bed simulator. Part II: Numerical results and assessment (2004) Thermal En-gineering, 4, pp. 49-54Costa, A.M.S., de Souza-Santos, M.L., A Novel Mechanism for Bubble Formation in Fluidized Systems: The Effects of Granu-lar Temperature on the Stability in Fluidization (2004) Brazilian Journal of Chemical Engineering, 21, pp. 479-486de Souza-Santos, M.L., A New Version of CSFB, Comprehensive Simulator for Fluidized Bed Equipment (2007) Fuel, 86, pp. 1684-1709de Souza-Santos, M.L., Comprehensive Simulator (CSFMB) Applied to Circulating Fluidized Bed Boilers and Gasifiers (2008) The Open Chemical Engineering Journal, 2, pp. 106-118Rabi, J.A., de Souza-Santos, M.L., Comparison of Two Model Approaches Implemented in a Comprehensive Fluidized-Bed Simulator to Predict Radiative Heat Transfer: Results for a Coal-Fed Boiler (2008) Computer and Experimental Simulations in Engineer-ing and Science, 3, pp. 87-105de Souza-Santos, M.L., CSFB Applied to Fluidized-bed Gasifica-tion of Special Fuels (2009) Fuel, 88, pp. 826-833Bastos-Netto, D., Riehl, R., de Souza-Santos, M.L., Conceptual Design of a Sugar Cane Bagasse Gasifier (2010) ICCEU2010-10th In-ternational Conference on Combustion and Energy Utilization, Mugla, , 4-8 May, Turke
Environmental Services Associated With The Reclamation Of Areas Degraded By Mining: Potential For Payments For Environmental Services
This paper discusses the potential of associating environmental services (ES) with techniques for reclaiming degraded areas (RDA) used in the mining sector, considering the current trends in payments for environmental services (PES) in Brazil. A literature review with content analysis generated results which identified the ES generated for eight cases of RDA in mining. As an example, ES related to soil enhancement were found. A more extended review of general RDA techniques confirmed the potential for associating other ES to RDA techniques used in mining, an example here is the enhancement of carbon stocks. Support for actions could come from existing PES schemes, particularly for cases where the ES identified as associated with an RDA technique are related to soil and water conservation. Concluding remarks indicate that there is a potential scenario for ES diversification in the reclamation stage of mining operations. A first step towards accomplishing this diversification envisages the creation of a PES scheme specific to the mining sector. Further studies are needed to develop criteria for fostering a PES scheme specifically for the reclamation phase of mining operations in Brazil.19213716
Origin and main ramifications of coeliac artery in Cerdocyon thous
Background: Cerdocyon thous is the canid with the greatest geographical coverage in South America. The aim of this study was to describe the origin, skeletopy, length and main branches of the coeliac artery in C. thous. Materials and methods: The dissections were performed on 14 cadavers of adult specimens, 6 males and 8 females, with a rostrosacral length average of 67.00 ± 4.7 cm and 62.09 ± 5.7 cm, respectively. The specimens were collected dead on highways on the banks of the Atlantic Forest (Rio de Janeiro) and the Pampa biome (Rio Grande do Sul) in Brazil. The cadavers were fixed and preserved in a formaldehyde solution until dissection. The coeliac artery was dissected, the length was measured “in situ” and its main branches were recorded. The coeliac artery emerged as a single artery in all dissected animals. Results: The average length of the coeliac artery was 1.43 ± 0.17 cm in males and 1.39 mm ± 0.24 cm in females, with no significant difference in this measurement between sexes. The predominant skeletopy was at the level of the second lumbar vertebra (57.1%), positioned on average 1.43 cm cranially to the cranial mesenteric artery. In most individuals (92.9%), the classic trifurcation was formed: the coeliac artery branched into the hepatic, left gastric, and lienal arteries. Only 1 male animal presented a bifurcation formed between the hepatic artery and a gastrolienal trunk. Conclusions: These anatomical characteristics are similar to those of other species of the Canidae family, possibly due to their phylogenetic proximity
The Use of Autoscopy From the Epistemological Perspective of Action Research for Self-Analysis and Reflection of Teacher Practice
The video recording of lessons allows the analysis results to provide data about the teaching practice. Analyzing the pedagogical practice itself allows the teacher an exercise of self-reflection, as they become aware of their behavior in the classroom, leading to the revitalization of their teaching model. This study aims to present the use of autoscopy as a stimulus to reflection, to a new understanding of the pedagogical practice of teachers, in an action research. This is a case study, with a qualitative and descriptive approach, performed with a new nursing teacher. The data were initially collected through a semistructured biographical interview and subsequent video recording of the classes, characterizing nonparticipant observations. The application of autoscopy followed the proposal of action research, with its phases: exploratory phase, in-depth research, action phase, and evaluation phase. The autoscopy was a useful strategy to stimulate teacher reflection because during the projection of the sketches selected for the video of the autoscopy session, the teacher can see himself or herself in action and self-analyze and discuss the selected pedagogical moments, stimulating reflection and generating a new understanding about his or her teaching practice. In this way, the use of autoscopy under the epistemological perspective of action research stimulates the self-analysis and reflection of the teaching practice
Nuevas formas farmacéuticas para el tratamiento de enfermedades alérgicas
Specific immunotherapy involves certain drawbacks which could be minimized by the use of appropriate adjuvants, capable of amplifying the right immune response with minimal side effects. In this context, we review different types of immunotherapy vehicles and coadyuvants. We describe previous studies by our group in which we demonstrated the adjuvant capacity of Gantrez® AN nanoparticles, which can effectively enhance the immune response. We employed two types of nanoparticles (with and without LPS of Brucella ovis as immunomodulator) within capsulated ovoalbumin and Lollium perenne extract, tested on a model of mice sensitized to this allergenic mixture. In the challenge experiment involving the sensitized mice, differences in the mortality rate and in the MCP-1 levels were found between the treated groups and the control. Under the experimental conditions of this model of mice pre-sensitized to L. perenne, Gantrez®AN nanoparticles appeared to be a good strategy for immunotherapy. We finally tested these carriers administered by the oral route and found that they were able to protect a model of mice sensitized to ovalbumin from anaphylactic shock
Nanoparticulate adjuvants and delivery systems for allergen immunotherapy
In the last decades, significant progress in research and clinics has been made to offer possible innovative therapeutics for the management of allergic diseases. However, current allergen immunotherapy shows limitations concerning the long-term efficacy and safety due to local side effects and risk of anaphylaxis. Thus, effective and safe vaccines with reduced dose of allergen have been developed using adjuvants. Nevertheless, the use of adjuvants still has several disadvantages, which limits its use in human vaccines. In this context, several novel adjuvants for allergen immunotherapy are currently being investigated and developed. Currently, nanoparticles-based allergen-delivery systems have received much interest as potential adjuvants for allergen immunotherapy. It has been demonstrated that the incorporation of allergens into a delivery system plays an important role in the efficacy of allergy vaccines. Several nanoparticles-based delivery systems have been described, including biodegradable and nondegradable polymeric carriers. Therefore, this paper provides an overview of the current adjuvants used for allergen immunotherapy. Furthermore, nanoparticles-based allergen-delivery systems are focused as a novel and promising strategy for allergy vaccines
Structure and Mechanism of Dimer-Monomer Transition of a Plant Poly(A)-Binding Protein upon RNA Interaction: Insights into Its Poly(A) Tail Assembly
Poly(A)-binding proteins (PABPs) play crucial roles in mRNA biogenesis, stability, transport and translational control in most eukaryotic cells. Although animal PABPs are well-studied proteins, the biological role, three-dimensional structure and RNA-binding mode of plant PABPs remain largely uncharacterized. Here, we report the structural features and RNA-binding mode of a Citrus sinensis PABP (CsPABPN1). CsPABPN1 has a domain architecture of nuclear PABPs (PABPNs) with a single RNA recognition motif (RRM) flanked by an acidic N-terminus and a GRPF-rich C-terminus. The RRM domain of CsPABPN1 displays virtually the same three-dimensional structure and poly(A)-binding mode of animal PABPNs. However, while the CsPABPN1 RRM domain specifically binds poly(A), the full-length protein also binds poly(U). CsPABPN1 localizes to the nucleus of plant cells and undergoes a dimer–monomer transition upon poly(A) interaction. We show that poly(A) binding by CsPABPN1 begins with the recognition of the RNA-binding sites RNP1 and RNP2, followed by interactions with residues of the β2 strands, which stabilize the dimer, thus leading to dimer dissociation. Like human PABPN1, CsPABPN1 also seems to form filaments in the presence of poly(A). Based on these data, we propose a structural model in which contiguous CsPABPN1 RRM monomers wrap around the RNA molecule creating a superhelical structure that could not only shield the poly(A) tail but also serve as a scaffold for the assembly of additional mRNA processing factors
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