1,583 research outputs found
Application and validation of the notch master curve in medium and high strength structural steels
This paper applies and validates the Notch master curve in two ferritic steels with medium (steel S460M) and high (steel S690Q) strength. The Notch master curve is an engineering tool that allows the fracture resistance of notched ferritic steels operating within their corresponding ductile-to-brittle transition zone to be estimated. It combines the Master curve and the Theory of critical distances in order to take into account the temperature and the notch effect respectively, assuming that both effects are independent. The results, derived from 168 fracture tests on notched specimens, demonstrate the capability of the Notch master curve for the prediction of the fracture resistance of medium and high strength ferritic steels operating within their ductile-to-brittle transition zone and containing notches
Active shape correction of a thin glass/plastic X-ray mirror
Optics for future X-ray telescopes will be characterized by very large
aperture and focal length, and will be made of lightweight materials like glass
or plastic in order to keep the total mass within acceptable limits. Optics
based on thin slumped glass foils are currently in use in the NuSTAR telescope
and are being developed at various institutes like INAF/OAB, aiming at
improving the angular resolution to a few arcsec HEW. Another possibility would
be the use of thin plastic foils, being developed at SAO and the Palermo
University. Even if relevant progresses in the achieved angular resolution were
recently made, a viable possibility to further improve the mirror figure would
be the application of piezoelectric actuators onto the non-optical side of the
mirrors. In fact, thin mirrors are prone to deform, so they require a careful
integration to avoid deformations and even correct forming errors. This however
offers the possibility to actively correct the residual deformation. Even if
other groups are already at work on this idea, we are pursuing the concept of
active integration of thin glass or plastic foils with piezoelectric patches,
fed by voltages driven by the feedback provided by X-rays, in intra-focal setup
at the XACT facility at INAF/OAPA. In this work, we show the preliminary
simulations and the first steps taken in this project
Optimising intervention implementation in the DCM (TM) epic trial (dementia care mapping (TM) : to enable person-centred care in care homes)
The Changing Face of Heroin Use in the United States: A Retrospective Analysis of the Past 50 Years
IMPORTANCE: Over the past several years, there have been a number of mainstream media reports that the abuse of heroin has migrated from low-income urban areas with large minority populations to more affluent suburban and rural areas with primarily white populations.
OBJECTIVE: To examine the veracity of these anecdotal reports and define the relationship between the abuse of prescription opioids and the abuse of heroin.
DESIGN, SETTING, AND PARTICIPANTS: Using a mixed-methods approach, we analyzed (1) data from an ongoing study that uses structured, self-administered surveys to gather retrospective data on past drug use patterns among patients entering substance abuse treatment programs across the country who received a primary (DSM-IV) diagnosis of heroin use/dependence (n = 2797) and (2) data from unstructured qualitative interviews with a subset of patients (n = 54) who completed the structured interview.
MAIN OUTCOMES AND MEASURES: In addition to data on population demographics and current residential location, we used cross-tabulations to assess prevalence rates as a function of the decade of the initiation of abuse for (1) first opioid used (prescription opioid or heroin), (2) sex, (3) race/ethnicity, and (4) age at first use. Respondents indicated in an open-ended format why they chose heroin as their primary drug and the interrelationship between their use of heroin and their use of prescription opioids.
RESULTS: Approximately 85% of treatment-seeking patients approached to complete the Survey of Key Informants\u27 Patients Program did so. Respondents who began using heroin in the 1960s were predominantly young men (82.8%; mean age, 16.5 years) whose first opioid of abuse was heroin (80%). However, more recent users were older (mean age, 22.9 years) men and women living in less urban areas (75.2%) who were introduced to opioids through prescription drugs (75.0%). Whites and nonwhites were equally represented in those initiating use prior to the 1980s, but nearly 90% of respondents who began use in the last decade were white. Although the high produced by heroin was described as a significant factor in its selection, it was often used because it was more readily accessible and much less expensive than prescription opioids.
CONCLUSION AND RELEVANCE: Our data show that the demographic composition of heroin users entering treatment has shifted over the last 50 years such that heroin use has changed from an inner-city, minority-centered problem to one that has a more widespread geographical distribution, involving primarily white men and women in their late 20s living outside of large urban areas
Consequências fisiológicas da dessecação em sementes de açaí (Euterpe oleracea Mart.).
O presente trabalho foi realizado com o objetivo de verificar os efeitos imediatos da desidratação sobre a qualidade fisiológica de sementes de açaí. Anteriormente à secagem das sementes da cultivar BRS Pará foi determinado o teor de água das mesmas e selecionado o lote daquelas que apresentavam o maior teor de água, que foi de 43,4%. As sementes foram submetidas à secagem, em equipamento com circulação forçada de ar (30±2ºC), até atingirem o teor de água de 37,4%, 30,3% 26,1%, 21,0%, 15,% e 11,9%, constituindo os demais tratamentos. O efeito da secagem sobre a qualidade das sementes foi avaliado por meio das determinações de germinação, tempo médio de germinação, velocidade de emergência, comprimento e massa da matéria seca de plântulas. A secagem até 37,4% de água não produz efeitos fisiológicos prejudiciais imediatos sobre as sementes de açaí, contudo, abaixo de 30,3% há redução progressiva da germinação e do vigor das sementes e ao atingirem 15,1% de teor de água, o desempenho fisiológico é anulado.Título em inglês: Physiological consequences of desiccation in Euterpe oleracea Mart. seeds. Disponível também on-line
Conservação de sementes de açaí (Euterpe oleracea Mart.).
Sementes de Euterpe oleracea são consideradas recalcitrantes e demandam ampliação do conhecimento sobre os fatores que interferem na sua conservação. Diante disso, o presente trabalho foi realizado com o objetivo de verificar os efeitos do teor de água da semente e da temperatura do ambiente na manutenção da qualidade das mesmas. Sementes da cultivar BRS Pará, com diferentes teores de água (43,4; 37,4; 30,3; 26,1; 21,0; 15,1 e 11,9%) e acondicionadas em sacos de polietileno foram armazenadas sob temperaturas de 20, 15 e 10 ºC durante 360 dias e submetidas a avaliações periódicas do teor de água, da germinação e do vigor. A secagem parcial até 37,4% de água não produz efeitos imediatos sobre a germinação e o vigor das sementes, a partir daí a secagem favorece, progressivamente, a deterioração das sementes e, ao atingirem 15,1% as sementes não germinam. Após o armazenamento, sementes com 21,0% de água ou menos não germinam independentemente da temperatura. A associação de 43,4% de água na semente e o armazenamento em ambiente a 20 ºC favorece a conservação das sementes por até 270 dias
A Sustainable Hydroxypropyl Cellulose-Nanodiamond Composite for Flexible Electronic Applications
Designing fully green materials for flexible electronics is an urgent need due to the growing awareness of an environmental crisis. With the aim of developing a sustainable, printable, and biocompatible material to be exploited in flexible electronics, the rheological, structural and charge transport properties of water-based hydroxypropyl cellulose (HPC)-detonation nanodiamond (DND) viscous dispersions are investigated. A rheological investigation disclosed that the presence of the DND affects the orientation and entanglement of cellulose chains in the aqueous medium. In line with rheological analyses, the NMR diffusion experiments pointed out that the presence of DND modifies the hydrodynamic behavior of the cellulose molecules. Despite the increased rigidity of the system, the presence of DND slightly enhances the ionic conductivity of the dispersion, suggesting a modification in the charge transport properties of the material. The electrochemical analyses, performed through Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS), revealed that the HPC-DND system is remarkably stable in the explored voltage range (−0.1 to +0.4 V) and characterized by a lowered bulk resistance with respect to HPC. Such features, coupled with the printability and filmability of the material, represent good requirements for the exploitation of such systems in flexible electronic applications
An Expert Opinion on the Role of the Rosuvastatin/Amlodipine Single Pill Fixed Dose Combination in Cardiovascular Prevention
Current cardiovascular disease prevention strategies are based on the management of cardiovascular risk as a continuum, redefining the therapeutic goals for each individual based on the estimated global risk profile. Given the frequent clustering of the principal cardiovascular risk factors, such as hypertension, diabetes and dyslipidaemia, in the same individual, patients are required to take multiple drugs to achieve therapeutic targets. The adoption of single pill fixed dose combinations may contribute to achieve better control of blood pressure and cholesterol compared to the separate administration of the individual drugs, mostly due to better adherence related to therapeutic simplicities. This paper reports the outcomes of an Expert multidisciplinary Roundtable. In particular, the rational and potential clinical use of the single pill fixed dose combination "Rosuvastatin-Amlodipine" for the management of concomitant hypertension/hypercholesterolemia in different clinical fields are discussed. This Expert Opinion also illustrates the importance of an early and effective management of total cardiovascular risk, highlights the substantial benefits of combining blood pressure and lipid-lowering treatments in a single-pill fixed dose combination and attempts to identify and overcome the barriers to the implementation in clinical practice of the fixed dose combinations with dual targets. This Expert Panel identifies and proposes the categories of patients who may benefit the most from this fixed dose combination
High-speed data transfer with FPGAs and QSFP+ modules
We present test results and characterization of a data transmission system
based on a last generation FPGA and a commercial QSFP+ (Quad Small Form
Pluggable +) module. QSFP+ standard defines a hot-pluggable transceiver
available in copper or optical cable assemblies for an aggregated bandwidth of
up to 40 Gbps. We implemented a complete testbench based on a commercial
development card mounting an Altera Stratix IV FPGA with 24 serial transceivers
at 8.5 Gbps, together with a custom mezzanine hosting three QSFP+ modules. We
present test results and signal integrity measurements up to an aggregated
bandwidth of 12 Gbps.Comment: 5 pages, 3 figures, Published on JINST Journal of Instrumentation
proceedings of Topical Workshop on Electronics for Particle Physics 2010,
20-24 September 2010, Aachen, Germany(R Ammendola et al 2010 JINST 5 C12019
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