784 research outputs found
Aluminum base alloy powder metallurgy process and product
A metallurgical method including cooling molten aluminum particles and consolidating resulting solidified particles into a multiparticle body, wherein the improvement comprises the provision of greater than 0.15% of a metal which diffuses in the aluminum solid state at a rate less than that of Mn. Aluminum containing greater than 0.15% of a metal which diffuses in the aluminum solid state at a rate less than that of Mn
Assessment of impact damage of composite rocket motor cases
This contract reviewed the available literature on mechanisms of low velocity impact damage in filament wound rocket motor cases, MDE methods to quantify damage, critical coupon level test methods, manufacturing and material process variables and empirical and analytical modeling off impact damage. The critical design properties for rocket motor cases are biaxial hoop and axial tensile strength. Low velocity impact damage is insidious because it can create serious nonvisible damage at very low impact velocities. In thick rocket motor cases the prevalent low velocity impact damage is fiber fracture and matrix cracking adjacent to the front face. In contrast, low velocity loading of thin wall cylinders induces flexure, depending on span length and the flexure induces delamination and tensile cracking on the back face wall opposed to impact occurs due to flexural stresses imposed by impact loading. Important NDE methods for rocket motor cases are non-contacting methods that allow inspection from one side. Among these are vibrothermography, and pulse-echo methods based on acoustic-ultrasonic methods. High resolution techniques such as x-ray computed tomography appear to have merit for accurate geometrical characterization of local damage to support development of analytical models of micromechanics. The challenge of coupon level testing is to reproduce the biaxial stress state that the full scale article experiences, and to determine how to scale the composite structure to model full sized behavior. Biaxial tensile testing has been performed by uniaxially tensile loading internally pressurized cylinders. This is experimentally difficult due to gripping problems and pressure containment. Much prior work focused on uniaxial tensile testing of model filament wound cylinders. Interpretation of the results of some studies is complicated by the fact that the fabrication process did not duplicate full scale manufacturing. It is difficult to scale results from testing subscale cylinders since there are significant differences in out time of the resins relative to full scale cylinder fabrication, differences in hoop fiber tensioning and unsatisfactory coupon configurations. It appears that development of a new test method for subscale cylinders is merited. Damage tolerance may be improved by material optimization that uses fiber treatments and matrix modifications to control the fiber matrix interface bonding. It is difficult to develop process optimization in subscale cylinders without also modeling the longer out times resins experience in full scale testing. A major breakthrough in characterizing the effect of impact damage on residual strength, and understanding how to scale results of subscale evaluations, will be a sound micromechanical model that described progressive failure of the composite. Such models will utilize a three dimensional stress analysis due to the complex nature of low velocity impact stresses in thick composites. When these models are coupled with non-contact NDE methods that geometrically characterize the damage and acoustic methods that characterize the effective local elastic properties, accurate assessment of residual strength from impact damage may be possible. Directions for further development are suggested
A DR4:tBID axis drives the p53 apoptotic response by promoting oligomerization of poised BAX
The cellular response to p53 activation varies greatly in a stimulus‐ and cell type‐specific manner. Dissecting the molecular mechanisms defining these cell fate choices will assist the development of effective p53‐based cancer therapies and also illuminate fundamental processes by which gene networks control cellular behaviour. Using an experimental system wherein stimulus‐specific p53 responses are elicited by non‐genotoxic versus genotoxic agents, we discovered a novel mechanism that determines whether cells undergo proliferation arrest or cell death. Strikingly, we observe that key mediators of cell‐cycle arrest (p21, 14‐3‐3σ) and apoptosis (PUMA, BAX) are equally activated regardless of outcome. In fact, arresting cells display strong translocation of PUMA and BAX to the mitochondria, yet fail to release cytochrome C or activate caspases. Surprisingly, the key differential events in apoptotic cells are p53‐dependent activation of the DR4 death receptor pathway, caspase 8‐mediated cleavage of BID, and BID‐dependent activation of poised BAX at the mitochondria. These results reveal a previously unappreciated role for DR4 and the extrinsic apoptotic pathway in cell fate choice following p53 activation.Fil: Henry, Ryan E. State University Of Colorado-boulder; Estados UnidosFil: Andrysik, Zdenek. State University Of Colorado-boulder; Estados UnidosFil: Paris, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentina. State University Of Colorado-boulder; Estados UnidosFil: Galbraith, Matthew D.. State University Of Colorado-boulder; Estados UnidosFil: Espinosa, Joaquín M.. State University Of Colorado-boulder; Estados Unido
The case for retaining borderline personality disorder as a psychiatric diagnosis
No AbstractPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62138/1/73_ftp.pd
Improvement of Thermal Insulation of Residential Buildings’ Facades Via Acoustic Insulation.
The European community has been undertaking noise mapping of major cities and transportation routes over the last decade. Implementation of the action plan to achieve reduction in people noise exposure is a key aim of the European Noise Directive (END) action planning.The French Environment and Energy Management Agency (ADEME) and Réseau Ferré de France (RFF) combine their resources to reduce the noise exposure of noise sensitive receivers (NSRs) near railway lines. The acoustic insulation of façades near railway lines is quantified and improved if necessary. As part of these operations, a parallel improvement to the thermal performance of the façades is often possible, and may be incorporated into the acoustic mitigation designs.This paper aims to evaluate the acoustic and thermal improvements achieved during an EU pilot project concerned with the mitigation of freight train noise in three towns in the Rhône-Alpes region of France. Calculations of both the energy consumption and sound insulation of NSR façades prior to mitigation work are compared with measurements undertaken following the façade upgrades. This study focuses on a sampling of typical buildings built prior to 1978 (over 900 properties)
The prevalence and clinical associations of mood instability in adults living in England : results from the Adult Psychiatric Morbidity Survey 2007
Mood instability is underinvestigated but potentially clinically important. This study aimed to describe the prevalence of mood instability in adults living in England and test whether it is important in explaining the extent of symptoms of common mental disorders, suicidality and healthcare use. An analysis of data from the Adult Psychiatric Morbidity Survey 2007, a household survey of private households in England (N=7403), was completed. The prevalence of mood instability was 13.9%. In univariate analysis it was strongly associated with socio-demographic and clinical variables. In regression modelling mood instability was independently associated with non-psychotic psychopathology, increasing the odds by 9.89. It was also linked with suicidal ideas (odds ratios (OR): 2.04) but not suicidal acts, and associated with being in receipt of medication, counselling or therapy for mental health problems (OR: 1.88), independent of a diagnosis of borderline personality disorder. Mood instability is relatively common in the adult population, occurs frequently in common mental disorders and appears to be an important symptom in its own right. It is associated with two important measures in psychiatry, namely suicidal thinking and healthcare service use. It warrants more widespread recognition and further research is required to understand if, when and how to intervene
Palaeomagnetism of the Ordovician dolerites of the Crozon Peninsula (France)
In order to obtain a Lower Palaeozoic pole for the Armorican Massif and to test the origin of the Ibero-Armorican arc, the Ordovician dolerites of the Crozon peninsula have been palaeomagnetically studied. The samples show a multicomponent magnetization which has been revealed by AF and thermal demagnetization and thoroughly investigated with rock magnetic experiments, polished section examinations and K/Ar dating. Four groups of directions have been recognized, often superimposed on each other in an individual sample. One component (D) has always the lowest blocking temperatures and coercivities and is considered to be of viscous origin, acquired recently in situ or in the laboratory during storage. Two components (A and B) are interpreted to be of secondary origin and to correspond to the observed K/Ar age distribution between 300 and 190 Myr. These ages represent the time interval between two regional thermo-tectonic events, associated with the Hercynian orogeny and the intrusion of dykes related to the early opening of the Central Atlantic Ocean and the Bay of Biscay. A fourth component (C) could be of Ordovician or younger Palaeozoic age; it is not clear whether the age of the magnetization is pre- or post-folding, but a pre-folding age would yield a direction of magnetization similar to Ordovician results from the Iberian peninsula. The latter interpretation suggests a fairly high palaeolatitude, which is in agreement with a glacio-marine postulated for sediments overlying the dolerite sills.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73214/1/j.1365-246X.1983.tb03785.x.pd
Ecological and behavioural risk factors of scrub typhus in central Vietnam: a case‑control study
Background: The risk factors for scrub typhus in Vietnam remain unknown. Scrub typhus caused by Orientia tsutsugamushi often presents as an undifferentiated febrile illness and remains under appreciated due to the limited availability of diagnostic tests. This tropical rickettsial illness is increasingly recognized as an important cause of non-malaria acute undifferentiated fever in Asia. This study aimed to investigate behavioural and ecological related risk factors of scrub typhus to prevent this potentially life-threatening disease in Vietnam. Methods: We conducted a clinical hospital-based active surveillance study, and a retrospective residence-enrolment date-age-matched case-control study in Khanh Hoa province, Vietnam, from August 2018 to March 2020. Clinical examinations, polymerase chain reaction and enzyme-linked immunosorbent assay IgM tests were applied to define cases and controls. All enrolled participants filled out a questionnaire including demographic socio-economic status, personal behaviors/protective equipment, habitat connections, land use, and possible exposure to the vector. Multivariable conditional logistic regression was used to define the scrub typhus associated risk factors. Results: We identified 44 confirmed cases and matched them with 152 controls. Among cases and controls, the largest age group was the 41-50 years old and males accounted for 61.4% and 42.8%, respectively. There were similarities in demographic characteristics between the two groups, with the exception of occupation. Several factors were significantly associated with acquisition of scrub typhus, including sitting/laying directly on household floor [adjusted OR (aOR) = 4.9, 95% CI: 1.6-15.1, P = 0.006], household with poor sanitation/conditions (aOR = 7.9, 95% CI: 1.9-32.9, P = 0.005), workplace environment with risk (aOR = 3.0, 95% CI: 1.2-7.6, P = 0.020), always observing mice around home (aOR = 3.7, 95% CI: 1.4-9.9, P = 0.008), and use of personal protective equipment in the field (aOR = 0.4, 95% CI: 0.1-1.1, P = 0.076). Conclusions: Ecological and household hygiene-related factors were more associated with scrub typhus infection,than individual-level exposure activities in the hyper-endemic area. These findings support local education and allow people to protect themselves from scrub typhus, especially in areas with limitations in diagnostic capacit
Catalogue des faïences anciennes françaises et européennes ... faïences orientales ... porcelaines de Chine, médaillons en terre cuite ... composant la collection de feu M. Manzi
Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201
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