Search for gravitational waves associated with the gamma ray burst GRB030329 using the LIGO detectors

We have performed a search for bursts of gravitational waves associated with the very bright gamma ray burst GRB030329, using the two detectors at the LIGO Hanford Observatory. Our search covered the most sensitive frequency range of the LIGO detectors (approximately 80 - 2048 Hz), and we specifically targeted signals shorter than 150ms. Our search algorithm looks for excess correlated power between the two interferometers and thus makes minimal assumptions about the gravitational waveform. We observed no candidates with gravitational-wave signal strength larger than a predetermined threshold. We report frequency-dependent upper limits on the strength of the gravitational waves associated with GRB030329. Near the most sensitive frequency region, around 250Hz, our root-sum-square (RSS) gravitational-wave strain sensitivity for optimally polarized bursts was better than hRSS 6×10-21Hz-1/2. Our result is comparable to the best published results searching for association between gravitational waves and gamma ray bursts. © 2005 The American Physical Society

Limits on gravitational-wave emission from selected pulsars using LIGO data

We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10-24. These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10-5 for the four closest pulsars. © 2005 The American Physical Society

Níveis de energia digestível sobre os desempenhos reprodutivo e zootécnico e a deposição de lipídios nos hepatócitos de machos de tilápia-do-nilo

O experimento foi conduzido com o objetivo de avaliar o desempenho reprodutivo e zootécnico e a deposição de lipídios no tecido hepático de machos de tilápia-do-nilo alimentados com rações contendo diferentes níveis de energia digestível, obtidos com a inclusão de óleo de soja. Foram utilizados 400 reprodutores (300 fêmeas e 100 machos) distribuídos em delineamento inteiramente casualizado, composto de cinco níveis de energia digestível (2.700, 2.950, 3.200, 3.450 e 3.700 kcal.kg de ração-1) e quatro repetições. Os reprodutores foram alimentados com rações contendo 35% de proteína bruta e submetidos ao manejo reprodutivo em hapas por 101 dias. O melhor resultado de concentração espermática e percentual de espermatozoides normais foram obtidos para reprodutores alimentados com rações contendo 3.465,56 e 3.443,43 kcal. kg de ração-1, que produziram 7,98 × 10(9) espermatozoides.mL de sêmen-1 e 38,98% de espermatozoides normais, respectivamente. A produção de sêmen, o pH seminal, o índice de sobrevivência espermática e o tempo de ativação espermática não foram afetados pelos níveis energéticos das rações. Os níveis de energia das rações não influenciaram o desempenho zootécnico dos peixes, mas promoveram aumento linear na deposição de lipídios nos hepatócitos e afetaram a qualidade seminal, estimulando a produção de espermatozoides e a melhora dos índices de normalidade da morfologia espermática em níveis energéticos próximos a 3.450 kcal. kg de ração-1.This experiment was carried out to evaluate the reproductive and zootechnical performance, and lipid deposition in the liver tissue of the Nile tilapia males fed diets containing different levels of digestible energy obtained from inclusion of soybean oil. Four hundred 400 broodfish (300 females and 100 males) were assigned to a completely randomized design composed of five levels of digestible energy (2,700, 2,950, 3,200, 3,450 and 3,700 kcal digestible energy.kg of feed-1) and four replications. The breeding were fed diets containing 35% of crude protein and submitted to hapas reproductive management for 101 days. The model adjusted by multiple regression analysis suggests the best result for sperm concentration and percentage of normal sperm for breeding fed diets containing 3.465.56 and 3.443.43 kcal digetible energy.kg of feed-1, producing 7.98 × 10(9) sperm.mL of semen-1 and 38.98% of normal sperm, respectively. The diet energy levels also caused an increase of lipid inclusion in the hepatocytes. The sperm production, seminal pH, sperm survival index and sperm activation time were not affected by energetic levels of the diets. The zootechnical performance was not affected by the energy levels of the diets either. The energy levels in the diets caused a linear increase in the lipid inclusion in the hepatocytes and affected the sperm quality by stimulating the spermatozoa production and the improving of normality indices of sperm morphology in energy levels around 3,450 kcal digestible energy.kg of feed-1

Egyptian LNG - The Value of Standardisation

This reference is for an abstract only. A full paper was not submitted for this conference. Abstract Key decisions at the beginning of any grassroots LNG project critically impact the ultimate success of the project. The variables to consider are numerous but from a high-level perspective, commercial variables such as available gas reserves, finance ability, corporate objectives and market penetration must be considered in combination with project related variables such as schedule, capital expenditures, and life cycle costs. The ultimate objective is to develop a strategy providing the highest rate of return to the owners whilst taking full account of the risks that can be managed by the owners. Shipping logistics, pre-investment for expansion trains, safety and environmental impact, technology selection and EPC contracting strategy all come into consideration early on in the process. One of the factors that most shape a LNG project is train capacity. Given the importance of economies of scale, the LNG train size that is chosen, along with the associated refrigeration turbine/compressor configuration, is a key decision that impacts almost all other variables. However, since the train capacity impacts so many project factors, the correct choice for one project is not necessarily the correct choice for another. The unique challenges that each project faces must be considered in order to arrive at the best decision for a given project. This paper draws on the experience of the Egyptian LNG project which is one of several grassroots projects started in the 2000's that remained with the nominal train size of 3.6 MTPA that became standard in the last half of the1990's. It should be noted that 3.6 MTPA is an annualized FOB rate - the actual PFD rate or design rate of the facility is over 4 MTPA. Some other contemporary projects have designed at 5 MTPA and one recent project has announced a 7.5MTPA train. Is it possible for smaller trains to compete in today's LNG business? The overall strategy for the Egyptian LNG project has been to standardize on the design developed for Atlantic LNG Trains 1–3. In this paper, we will provide an evaluation of the key considerations leading to this strategy and show that highly competitive capital costs can be achieved with smaller trains whilst also significantly reducing project schedule and minimizing owner risk. </jats:sec