1,366 research outputs found
Distribution and Demographics of Marine Mammals in SOCAL Through Photo-Identification, Genetics, and Satellite Telemetry: A Summary of Surveys Conducted 1 July 2011-15 June 2012
Prepared for: Chief of Naval Operations, Energy and Environmental Readiness Division, Washington, D.C.Results from the second year of a three-year project investigating the distribution, demographics, and behavior of cetaceans
in the US Navy’s Southern California operational area are summarized. Eighteen small vessel surveys for cetaceans, which
included species verification tests in conjunction with M3R (Marine Mammal Monitoring on Navy Undersea Ranges) acoustic
monitoring at the Southern California Anti-submarine Warfare Range (SOAR), as well as photo-identification, satellite
tagging, and biopsy sampling of species of interest, were conducted in July 2011 and January and March 2012. 112 groups of
14 cetacean species were encountered. Twenty-one satellite tags, some depth reporting, were deployed on four species, with
an emphasis on Cuvier’s beaked and fin whales. Among other findings, preliminary results of photo-identification studies
combined with results from satellite tag data suggest that both Cuvier’s beaked whales and fin whales may have population
sub-units with higher than expected residency to the Southern California Bight. Beaked whales particularly show this higher
than expected residency to SOAR.N00244-10-1-005
Distribution and Demographics of Marine Mammals in SOCAL Through Photo-Identification, Genetics, and Satellite Telemetry: A Summary of Surveys Conducted 1 July 2011-15 June 2012
Prepared for: Chief of Naval Operations, Energy and Environmental Readiness Division, Washington, D.C.Results from the second year of a three-year project investigating the distribution, demographics, and behavior of cetaceans
in the US Navy’s Southern California operational area are summarized. Eighteen small vessel surveys for cetaceans, which
included species verification tests in conjunction with M3R (Marine Mammal Monitoring on Navy Undersea Ranges) acoustic
monitoring at the Southern California Anti-submarine Warfare Range (SOAR), as well as photo-identification, satellite
tagging, and biopsy sampling of species of interest, were conducted in July 2011 and January and March 2012. 112 groups of
14 cetacean species were encountered. Twenty-one satellite tags, some depth reporting, were deployed on four species, with
an emphasis on Cuvier’s beaked and fin whales. Among other findings, preliminary results of photo-identification studies
combined with results from satellite tag data suggest that both Cuvier’s beaked whales and fin whales may have population
sub-units with higher than expected residency to the Southern California Bight. Beaked whales particularly show this higher
than expected residency to SOAR.N00244-10-1-005
Role of the iodide–methylammonium interaction in the ferroelectricity of CH3NH3PbI3
Excellent conversion efficiencies of over 20 % and facile cell production have placed hybrid perovskites at the forefront of novel solar cell materials, with CH3NH3PbI3 being an archetypal compound. The question why CH3NH3PbI3 has such extraordinary characteristics, particularly a very efficient power conversion from absorbed light to electrical power, is hotly debated, with ferroelectricity being a promising candidate. This does, however, require the crystal structure to be non‐centrosymmetric and we herein present crystallographic evidence as to how the symmetry breaking occurs on a crystallographic and, therefore, long‐range level. Although the molecular cation CH3NH3+ is intrinsically polar, it is heavily disordered and this cannot be the sole reason for the ferroelectricity. We show that it, nonetheless, plays an important role, as it distorts the neighboring iodide positions from their centrosymmetric positions
The incidence of metabolic syndrome and its reversal in a cohort of schizophrenic patients followed for one year
Cross-sectional studies showed a high prevalence of metabolic syndrome in patients with schizophrenia. This study aimed to identify the incidence of metabolic syndrome and its reversal in a non-preselected cohort of chronic psychotic patients in routine practice in one year follow-up and to find variables to describe development and reversal of metabolic syndrome. This cohort study was conducted as part of a disease management program and patients were included if they had two complete assessments in a one year follow-up. We conducted two logistic regressions to find variables to describe the development of metabolic syndrome and the reversal of metabolic syndrome. At the time of the first assessment 35% (n = 92) of the 260 included patients had metabolic syndrome. Within one year 21 patients developed metabolic syndrome and 30 patients had it reversed. This was an incidence of 13% (21/168) and a reversal of 33% (30/92). Smoking, family history of cardiovascular diseases, and duration of disease >6 years was associated with a higher risk of developing metabolic syndrome as well as abdominal obesity and dyslipidemia. Patients with abdominal obesity had a smaller chance of reversing metabolic syndrome. Other variables included in the logistic regression such as receiving cardiovascular/antidiabetic drug treatment or duration of disease >6 years did not alter the risk of reversing the metabolic syndrome. Our study showed that the natural course of metabolic syndrome is dynamic. A considerable number of patients developed or reversed the metabolic syndrome in one year follow-up. (C) 2009 Elsevier Ltd. All rights reserved
Reusability Studies for Ares I and Ares V Propulsion
With a mission to continue to support the goals of the International Space Station (ISS) and explore beyond Earth orbit, the United States National Aeronautics and Space Administration (NASA) is in the process of launching an entirely new space exploration initiative, the Constellation Program. Even as the Space Shuttle moves toward its final voyage, Constellation is building from nearly half a century of NASA spaceflight experience, and technological advances, including the legacy of Shuttle and earlier programs such as Apollo and the Saturn V rocket. Out of Constellation will come two new launch vehicles: the Ares I crew launch vehicle and the Ares V cargo launch vehicle. With the initial goal to seamlessly continue where the Space Shuttle leaves off, Ares will firstly service the Space Station. Ultimately, however, the intent is to push further: to establish an outpost on the Moon, and then to explore other destinations. With significant experience and a strong foundation in aerospace, NASA is now progressing toward the final design of the First Stage propulsion system for the Ares I. The new launch vehicle design will considerably increase safety and reliability, reduce the cost of accessing space, and provide a viable growth path for human space exploration. To achieve these goals, NASA is taking advantage of Space Shuttle hardware, safety, reliability, and experience. With efforts to minimize technical risk and life-cycle costs, the First Stage office is again pulling from NASA s strong legacy in aerospace exploration and development, most specifically the Space Shuttle Program. Trade studies have been conducted to evaluate life-cycle costs, expendability, and risk reduction. While many first stage features have already been determined, these trade studies are helping to resolve the operational requisites and configuration of the first stage element. This paper first presents an overview of the Ares missions and the genesis of the Ares vehicle design. It then looks at one of the most important trade studies to date, the "Ares I First Stage Expendability Trade Study." The purpose of this study was to determine the utility of flying the first stage as an expendable booster rather than making it reusable. To lower the study complexity, four operational scenarios (or cases) were defined. This assessment then included an evaluation of the development, reliability, performance, and transition impacts associated with an expendable solution. This paper looks at these scenarios from the perspectives of cost, reliability, and performance
Temperature dependent transient surface photovoltage spectroscopy of a Cu1.95Zn1.1Sn0.96Se4 kesterite single phase powder
An off-stoichiometric but single phase Cu1.95Zn1.1Sn0.96Se4 kesterite powder
was investigated by temperature dependent transient surface photovoltage (SPV)
spectroscopy. SPV signals excited at different wavelengths were transformed
into SPV spectra that depended on the response time of measurement. Shallow
electronic states and states with transition energies at 0.83 eV or 0.78… 0.9
eV were distinguished. The temperature dependence of the band gap of
Cu1.95Zn1.1Sn0.96Se4 was obtained. Results were discussed on the basis of
defects in Cu-poor and Zn-rich kesterite
Zinc germanium nitrides and oxide nitrides the influence of oxygen on electronic and structural properties
Zinc containing ternary nitrides, in particular ZnSnN 2 and ZnGeN 2 , have great potential as earth abundant and low toxicity light absorbing materials. The incorporation of oxygen in this system may it be intentional or unintentional affects the crystal structure of the materials as well as their optical band gaps. Herein, we explore the origins of structural changes between the wurtzite type and its hettotype, the b NaFeO 2 type, and highlight the effect of oxygen. Furthermore, we study the electronic structure and bonding in order to understand the reason for the narrower band gap of zinc germanium oxide nitrides as opposed to pure zinc germanium nitrid
NASA's Space Launch System and Deep Space Opportunities for Smallsats
Designed to provide the significant capability required for human deep-space exploration, the National Aeronautics and Space Administration's Space Launch System (SLS) also provides an exceptional opportunity for lower-cost deep-space science in the form of small-satellite (smallsat) secondary payloads. This opportunity will be leveraged beginning with the rocket's first flight; a launch of the SLS's Block 1 configuration, capable of delivering greater than 26 metric tons (t) to Trans-Lunar Injection (TLI), which will see the Orion crew vehicle travel around the Moon and return to Earth. On that flight, SLS will also deploy 13 6U-class CubeSat secondary payloads to multiple destinations including deep space. Preparations are already under way for future vehicle configurations, with the more capable Block 1B, able to deliver 40 metric tons to TLI. That configuration will have the capability to carry large payloads co-manifested with the Orion spacecraft, or to utilize an 8.4-meter (m) fairing to carry payloads several times larger than are currently possible. SLS will evolve to its full Block 2 configuration, with a TLI capability of greater than 45 metric tons. This paper will provide a status of the SLS development and outline the progress being made toward flying smallsats on SLS, and discuss future opportunities for smallsats
Intrinsic point defects in off stoichiometric Cu2ZnSnSe4 A neutron diffraction study
This work is an experimental study of intrinsic point defects in off stoichiometric kesterite type CZTSe by means of neutron powder diffraction. We revealed the existence of copper vacancies VCu , various cation anti site defects CuZn, ZnCu, ZnSn, SnZn, and CuZn , as well as interstitials Cui, Zni in a wide range of off stoichiometric polycrystalline powder samples synthesized by the solid state reaction. The results show that the point defects present in off stoichiometric CZTSe agree with the off stoichiometry type model, assuming certain cation substitutions accounting for charge balance. In addition to the known off stoichiometry types A H, new types I L have been introduced. For the very first time, a correlation between the chemical composition of the CZTSe kesterite type phase and the occurring intrinsic point defects is presented. In addition to the offstoichiometry type specific defects, the Cu Zn disorder is always present in the CZTSe phase. In Cu poor Zn rich CZTSe, a composition considered as the one that delivers the best photovoltaic performance, mainly copper vacancies, ZnCu and ZnSn anti sites are present. Also, this compositional region shows the lowest degree of Cu Zn disorde
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