7,443 research outputs found
EVALUATION OF ACCIDENTS WITH DOMINO EFFECT IN LPG STORAGE AREAS
The term domino effect denotes a chain of accidents, or situations, in which a fire/explosion
load generated by an accident in one unit in an industry causes secondary and higher order
accidents in other units. Such chains of accidents have a greater propensity to cause damage
than stand-alone accidents. Most of the past risk assessment studies deal with accident in
a single industry, more so in one of the units of an industry. But, often, accident in one unit
causes a secondary accident in a nearby unit, which in turn may trigger a tertiary accident,
and so on. The probability of occurrence and adverse impacts of such domino or
cascading effects are increasing due to increasing congestion in industrial complexes
and increasing density of human population around such complexes. Accidents with domino
effect are seldom studied. LPG storage areas could produce the worst possible consequences
in the event of an unforeseen incident. This work illustrates the application of models to
evaluate the impacts of events with fire and explosion in LPG tanks on other similar units
in the park and the possibility of occurrence of a domino effect. The criteria for occurrence
of accidents with domino effect adopted in this work were 37.5 kW/m2 in case of fire
radiation and an overpressure of 0.7 atm in explosion cases in a receptor body. The spacing
between LPG tanks was evaluated. The results show that such spacing is minimal and
does not represent, as it should, a parameter indicating a safe distance able to prevent the
propagation of an accident with domino effect
Effect of antibodies to intercellular adhesion molecule type 1 on the protection of distant organs during reperfusion syndrome in rats
We investigated kidney and lung alterations caused by intercellular adhesion molecule type 1 (ICAM-1) blockade after ischemia and reperfusion of hind limb skeletal muscles. Rats were submitted to ligature of the infrarenal aorta for 6 h. The animals were randomized into three groups of 6 rats each: group I, sacrificed after ischemia; group II, reperfusion for 24 h, and group III, reperfusion for 24 h after receiving monoclonal anti-ICAM-1 antibodies. At the end of the experiment, blood samples were collected for creatinine, lactate dehydrogenase, creatine phosphokinase, potassium, pH and leukocyte counts. Samples were taken from the muscles of the hind limbs and from the kidneys and lungs for histological analysis and measurement of the neutrophil infiltrate by myeloperoxidase staining. The groups did not differ significantly with regard to the laboratory tests. There were no major histological alterations in the kidneys. An intense neutrophil infiltrate in the lungs, similar in all groups, was detected. Myeloperoxidase determination showed that after reperfusion there was significantly less retention of polymorphonuclear neutrophils in the muscles (352 ± 70 vs 1451 ± 235 × 10² neutrophils/mg; P<0.01) and in the kidneys (526 ± 89 vs 852 ± 73 × 10² neutrophils/mg; P<0.01) of the animals that received anti-ICAM-1 before perfusion compared to the group that did not. The use of anti-ICAM-1 antibodies in this experimental model minimized neutrophil influx, thus reducing the inflammatory process, in the muscles and kidneys after ischemia and reperfusion of the hind limbs.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de CirurgiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de ClínicaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PatologiaUNIFESP, EPM, Depto. de CirurgiaUNIFESP, EPM, Depto. de ClínicaUNIFESP, EPM, Depto. de PatologiaSciEL
Inverting Time-Dependent Harmonic Oscillator Potential by a Unitary Transformation and a New Class of Exactly Solvable Oscillators
A time-dependent unitary (canonical) transformation is found which maps the
Hamiltonian for a harmonic oscillator with time-dependent real mass and real
frequency to that of a generalized harmonic oscillator with time-dependent real
mass and imaginary frequency. The latter may be reduced to an ordinary harmonic
oscillator by means of another unitary (canonical) transformation. A simple
analysis of the resulting system leads to the identification of a previously
unknown class of exactly solvable time-dependent oscillators. Furthermore, it
is shown how one can apply these results to establish a canonical equivalence
between some real and imaginary frequency oscillators. In particular it is
shown that a harmonic oscillator whose frequency is constant and whose mass
grows linearly in time is canonically equivalent with an oscillator whose
frequency changes from being real to imaginary and vice versa repeatedly.Comment: 7 pages, 1 figure include
Management Effect on Rainfall Use Efficiency and Growth Rate of Spineless Cactus \u3cem\u3ecv.\u3c/em\u3e Miúda in Northeast Brazil
Spineless cactus has a high rainfall use efficiency. Under water deficit, they open their stomata during the night to capture atmospheric carbon dioxide when the air temperature is lower and relative humidity higher (Taiz and Zeiger, 2009), losing less water to the atmosphere. The rainfall use efficiency (RUE) can be expressed as the amount of water used by the crop to produce dry matter (Han and Felker, 1997). The RUE showed by spineless cactus, a CAM plant, is three to five times greater than the one observed in C3 and C4 plants (Felker and Russel, 1988; Nobel, 1991). Therefore, spineless cacti (Nopaleae opuntia) are important forage resource in northeast Brazil. Management practices, however, can affect the RUE and growth of spineless cactus, especially organic and mineral fertilization. Thus, the objective of this research was to evaluate the effect of organic and nitrogen fertilization and harvest frequency on rainfall use efficiency and growth rate of spineless cactus cv. Miúda (Nopalea cochenillifera Salm Dyck)
Release of a New Forage Bermudagrass Cultivar from the USDA-NPGS Cynodon Collection
Warm-season perennial grasses are the backbone of the pasture-based livestock industry in the southeastern USA. In Florida specifically, bahiagrass (Paspalum notatum Flugge) and bermudagrass (Cynodon spp.) support 1 million head of cattle and 15,000 beef cattle operations. Bermudagrass is the most widely planted forage species in the southeastern USA, planted in approximately 15 million ha and used for grazing, hay and silage. The genus Cynodon is native to southern Africa and germplasm collections have revealed a high degree of genetic variability within the genus. The United States Department of Agriculture National Plant Germplasm System (USDA-NPGS) maintains a collection of bermudagrass plant introduction (PIs) in Griffin, GA, USA and the USDA Georgia Coastal Plains Experiment Station, Tifton, GA, maintains additional forage germplasm. Multi-location trials were established in 2014 in four states (FL, GA, NC and OK) to screen the collection for herbage accumulation (HA) and nutritive value (NV). Due to the large genotype by environment interaction for HA across states, we focused on selecting accessions adapted to South Georgia and Florida. Several PIs showed improved HA and NV compared to ‘Tifton 85’ across several trials and years. Particularly, PI 316510 produced high HA in Citra, FL and Tifton, GA, had improved NV traits, and faster establishment compared to Tifton 85. We confirmed that PI 316510 is tetraploid by chromosome counts and flow cytometry. The PI 316510 has been released by the University of Florida under the name “Newell”
Cinética ruminal de espécies forrageiras nativas da caatinga
This study aimed at evaluating the kinetics of in situ ruminal degradation of the dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) of five local forage species from the semi-arid region of Paraíba (Brazil): “Orelha de Onça” (Macroptilium Martii Benth), “Amor de Vaqueiro” (Desmodium canum), “Feijão Bravo” (Capparis Flexuosa), “Maniçoba” (Manihot Epruinosa) and “Imburana de Cambão” (Camniphora leptophloes). Four two-year-old male sheep, castrated, belonging to the breed Santa Inês, with an average weight of 40 kg, previously rumen-fistulated, were distributed in an entirely randomized statistical design, with subdivided portion. The animals were housed in individual stalls and fed ad libitum with diets containing hays of the studied forages and a mineral supplementation. The foods were ground, put into nylon bags and incubated during 0, 6, 12, 24, 48 and 96 hours. Chemical-bromatological analyses of the forages were carried out to determine in situ ruminal degradation. The solubility of DM was larger for “Feijão Bravo” hay. For the potentially degradable fraction of DM, "Maniçoba" hay presented the highest average value. Compared to the other forages, "Maniçoba" and “Feijão Bravo” hays showed the lowest percentage of the undegradable fraction (P <0,01), but the highest PD and ED (2-5%/h) of DM (P <0,01). “Feijão Bravo” hay presented the highest rates of PD and ED (2-5%/h) of CP. Among the forages examined, "Maniçoba" and “Feijão Bravo” hays presented the best potential for feeding. The degradability in the DM, CP and NDF indicated the best potential of use for “Feijão Bravo” and "Maniçoba", since the nutritional quality and efficiency of utilization in the rumen was higher for these forages.Este trabalho tem como objetivo avaliar a cinética da degradação ruminal in situ da matéria seca (MS), proteína bruta (PB) e fibra em detergente neutro (FDN) de cinco espécies forrageiras nativas: orelha de onça (Macroptilium Martii Benth), amor de vaqueiro (Desmodium canum), feijão bravo (Capparis Flexuosa), maniçoba (Manihot Epruinosa) e imburana de cambão (Camniphora leptophloes) do semi-árido paraibano. Quatro ovinos machos castrados, de dois anos de idade, da raça Santa Inês, com peso médio de 40 kg previamente canulados no rúmen, foram distribuídos em um delineamento experimental inteiramente casualizado, com parcela subdividida. Os animais foram alojados em baias individuais e alimentados à vontade com dietas contendo os fenos das forrageiras estudadas e suplementação mineral. Os alimentos foram moídos, colocados em sacos de náilon e incubados nos tempos 0, 6, 12, 24, 48 e 96 horas. Foram realizadas análises químico-bromatológicas (MS, PB e FDN) das forrageiras para determinação da degradação ruminal in situ. A solubilidade da MS foi maior (P>0,01) para o feno de feijão bravo. Quanto à fração potencialmente degradável da MS, o feno de maniçoba apresentou o maior valor médio. Os fenos de maniçoba e de feijão bravo apresentaram um menor percentual da fração não degradável entre as forrageiras avaliadas (P<0,01). O feno de maniçoba e feijão bravo apresentaram DP e DE (2-5%/h) da MS superior (P<0,01) às demais forrageiras. O feijão bravo apresentou as maiores taxas de DP e DE (2-5%/h) da PB. Os fenos das forrageiras, maniçoba e feijão-bravo, apresentaram o melhor potencial para arraçoamento dentre as forragens estudadas. A degradabilidade da MS, PB e FDN indicaram para os fenos de maniçoba e feijão bravo melhor potencial de utilização, visto que a qualidade nutritiva e a eficiência de aproveitamento no rúmen foram superiores para estas forragens
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