2,096 research outputs found
Parametric study of transport aircraft systems cost and weight
The results of a NASA study to develop production cost estimating relationships (CERs) and weight estimating relationships (WERs) for commercial and military transport aircraft at the system level are presented. The systems considered correspond to the standard weight groups defined in Military Standard 1374 and are listed. These systems make up a complete aircraft exclusive of engines. The CER for each system (or CERs in several cases) utilize weight as the key parameter. Weights may be determined from detailed weight statements, if available, or by using the WERs developed, which are based on technical and performance characteristics generally available during preliminary design. The CERs that were developed provide a very useful tool for making preliminary estimates of the production cost of an aircraft. Likewise, the WERs provide a very useful tool for making preliminary estimates of the weight of aircraft based on conceptual design information
Economic Crisis in Argentina and no way out?
Argentina has made the headlines of international media not only for its successful return to democratic political rules in December 1983 but also for its renewed slump into economic crisis. The country is no longer able to meet the debt servicing requirements and to repay loans due this year while auspices for rescheduling and extending foreign debt are bleak. As a corollary tovexternal problems, there are high public sector deficits, inflation is accelerating at a galopping pace, and net private investment has turned negative. Up to now, the new democratic government has not lived up to expectations since it did not present a reform package designed to overcome the severe economic problems of the country. Rather, the government has relied on some ad-hoc emergency measures in an attempt to prevent the crisis from turning into catastrophy
Reconstructing 3D x-ray CT images of polymer gel dosimeters using the zero-scan method
In this study x-ray CT has been used to produce a 3D image of an irradiated PAGAT gel sample, with noise-reduction achieved using the ‘zero-scan’ method. The gel was repeatedly CT scanned and a linear fit to the varying Hounsfield unit of each pixel in the 3D volume was evaluated across the repeated scans, allowing a zero-scan extrapolation of the image to be obtained. To minimise heating of the CT scanner’s x-ray tube, this study used a large slice thickness (1 cm), to provide image slices across the irradiated region of the gel, and a relatively small number of CT scans (63), to extrapolate the zero-scan image. The resulting set of transverse images shows reduced noise compared to images from the initial CT scan of the gel, without being degraded by the additional radiation dose delivered to the gel during the repeated scanning. The full, 3D image of the gel has a low spatial resolution in the longitudinal direction, due to the selected scan parameters. Nonetheless, important features of the dose distribution are apparent in the 3D x-ray CT scan of the gel. The results of this study demonstrate that the zero-scan extrapolation method can be applied to the reconstruction of multiple x-ray CT slices, to provide useful 2D and 3D images of irradiated dosimetry gels
Germinação de Eragrostis plana Nees sob efeito do extrato de Achyrocline satureioides (Lam.) DC.
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Review: ‘Gimme five’: future challenges in multiple sclerosis. ECTRIMS Lecture 2009
This article is based on the ECTRIMS lecture given at the 25th ECTRIMS meeting which was held in Düsseldorf, Germany, from 9 to 12 September 2009. Five challenges have been identified: (1) safeguarding the principles of medical ethics; (2) optimizing the risk/benefit ratio; (3) bridging the gap between multiple sclerosis and experimental autoimmune encephalitis; (4) promoting neuroprotection and repair; and (5) tailoring multiple sclerosis therapy to the individual patient. Each of these challenges will be discussed and placed in the context of current research into the pathogenesis and treatment of multiple sclerosis
Lixiviação de nitrogênio em um Cambissolo cultivado com pessegueiro e submetido à aplicação de composto orgânico.
A aplicação de composto orgânico em solos cultivados com pessegueiro pode potencializar a transferência de N por lixiviação. O trabalho objetivou avaliar a lixiviação de N em um solo cultivado com pessegueiro e submetido à aplicação de composto orgânico. Em um pomar comercial de pessegueiro no município de Bento Gonçalves (RS) foram instalados lisímetros a 20 cm de profundidade. O solo recebeu a aplicação de 0 e 144 litros de composto orgânico por planta-1 ano-1 nas safras de 2010, 2011 e 2012. A solução do solo foi coletada no período de julho a outubro de 2012 e submetida à análise de nitrato, amônio e N mineral. As maiores concentrações de N lixiviado foram encontradas no tratamento com 144 litros de composto orgânico por planta-1. A adubação com composto orgânico apresentou baixas concentrações de N lixiviado, o que pode contribuir com a redução de contaminação ambiental.Resumo expandido
Epidemiología de la Urgencia Psiquiátrica en el Instituto Psiquiátrico "Dr. José Horwitz": Un nuevo estudio comparativo
Indexación: ScieloUna urgencia psiquiátrica es cualquier alteración del afecto, conducta o pensamiento que puede producir daños a terceros o al consultante. La consulta de urgencia ido en aumento en los últimos años. Objetivos: Determinar laprevalencia de las distintas patologías, describir su distribución según sexo, edad, sector de residencia, estado civil, ocupación, previsión y derivación en las consultas de urgencia psiquiátrica en el Hospital Psiquiátrico "Dr. JoséHorwitz" de Santiago y comparar estos resultados con publicaciones previas de estudios en el mismo centro. Material y Método: Muestra representativa de 1999 casos, escogidos aleatoriamente de las consultas realizadas entre el Io de julio de 2005 y el 30 de junio de 2006. Se agruparon los diagnósticos de acuerdo a la nomenclatura CIÉ-10. Resultados: 48,7% de las consultas fueron realizadas por pacientes de sexo masculino. La media de edad fue 39 años. 76,7% de las consultas fueron realizadas en horario diurno. El 48,3% de los pacientes no tiene ocupación. 48% eran solteros. Abuso de sustancias y alcohol, trastornos esquizoides, afectivos y neuróticos congregan el 73,9% de las consultas. La más prevalente fue la de trastornos asociados al abuso de sustancias y alcohol con un 19,7% del total. Conductas autoagresivas (74%) y trastornos afectivos (74%) se asoció más a mujeres, en cambio el abuso de sustancias y alcohol más con hombres (76%). Discusión: Las consultas por trastornos esquizoides han disminuido a lo largo de los años. En cambio las consultas por el abuso de sustancias y alcohol y los trastornos afectivos han aumentado. Se hacen sugerencias para enfrentar el nuevo perfil epidemiológico.A psychiatric emergency is any alteration of affection, thought or behavior that may cause harm to others or to the same consultant. These consultations have increased over the last years. Objectives: Determine the prevalence of the various pathologies, describing their distribution according to sex, age, area of residence, marital status, occupation, health insurance, and referral in psychiatric emergency consultations at "Dr. José Horwitz" Hospital of Santiago, and to compare these results with previously published studies in the same center. Material and Method: We used a representative sample of 1999 cases, chosen randomly from consultations held between July 1,2005 and June 30,2006. Diagnoses were grouped according to the nomenclature of the ICD-10. Results: 48.7% of the consultations were carried out by male patients and. Average age of consultation was 39. 76.7% of consultations were carried out in daytime. The 48.3% of people who consulted didn't have any occupation. 48% were singles. Abuse of substances and alcohol, schizoid, afective and neurotic disorders congregate 73.9% of total consultations. The most prevalent were the disorders associated with abuse of substances and alcohols with a 19.7% overall. Autoagressive behaviors (74%) and affective disorders (74%) were associated with females, while abuse of substances and alcohol was associated with males (76%). Discussion: Schizoid disorders have proportionally declined in importance over the years. In contrast, abuse of substances and alcohol, and affective disorders have increased their frecuency. Suggestions are made to FACE the new epidemiological profile.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-92272010000400002&nrm=is
Physico-chemical foundations underpinning microarray and next-generation sequencing experiments
Hybridization of nucleic acids on solid surfaces is a key process involved in high-throughput technologies such as microarrays and, in some cases, next-generation sequencing (NGS). A physical understanding of the hybridization process helps to determine the accuracy of these technologies. The goal of a widespread research program is to develop reliable transformations between the raw signals reported by the technologies and individual molecular concentrations from an ensemble of nucleic acids. This research has inputs from many areas, from bioinformatics and biostatistics, to theoretical and experimental biochemistry and biophysics, to computer simulations. A group of leading researchers met in Ploen Germany in 2011 to discuss present knowledge and limitations of our physico-chemical understanding of high-throughput nucleic acid technologies. This meeting inspired us to write this summary, which provides an overview of the state-of-the-art approaches based on physico-chemical foundation to modeling of the nucleic acids hybridization process on solid surfaces. In addition, practical application of current knowledge is emphasized
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