3,860 research outputs found
Dynamic upper atmospheric force model on stabilized vehicles for a high-precision trajectory computer program
The upper atmosphere model draws heavily on the behavior of the earth's upper atmosphere which exhibits cyclic as well as irregular variations in density profile, temperature, pressure, and composition in unison with solar activities as deduced from the more recent land-based and satellite observations. The lift and drag model is designed specifically for inertially stabilized vehicles of the Mariner class, with possible extension to gravity gradient stabilized vehicles of the GEOS class. The model considers operation in the free molecular flow regimes with large Knudsen numbers. The vehicle is considered a composite structure with basic components having well-defined shapes, each with its own surface characteristics in terms of temperature, reflectivity, and accommodation of free stream molecules. The model takes into account both the calculation of precise aerodynamic force coefficients in terms of expansion of modified Bessel functions in speed ratios and angle of attack, and approximate force coefficients when the speed ratios approach infinity. Other considerations include specular and diffused reflectivity, shielding, and shadow effects
Delay in DOTS for new pulmonary tuberculosis patient from rural area of Wardha District, India
Vast majority of active tuberculosis patients seeks treatment, do so promptly, still many patients spend a great deal of time and money “shopping for health” and too often they do not receive either accurate diagnosis or effective treatment, despite spending considerable resources. Objective: To find out the time taken to, for diagnosis of tuberculosis and to put patient on DOTS from the onset of symptoms and pattern of health seeking behavior of new pulmonary tuberculosis patients. A cross-sectional rapid assessment using qualitative (FGD) and quantitative (Interview) methods conducted at DOTS center of tertiary care hospital from rural Wardha. Participants: 53 pulmonary tuberculosis patients already on DOTS, in intensive phase. Main outcome measure: Delay in initiation of DOTS & health seeking behavior Results: Median total delay for starting DOTS was 111 days, (range: 10 to 321 days). Patient delay was more than provider delay. Patients delay was more in patients above 60 years, illiterate, per-capita income below 650 Rupees and HIV TB co-infection. Pattern of health seeking behavior was complex. Family physician was the preferred health care provider. Patient visited on an average four providers and spent around 1450 rupees (only direct cost) before DOTS begin. Time taken from the onset of symptoms and start of DOT is a cause of concern for the tuberculosis control program. Early case detection is important rather than mere achieving target of 70% new case detection. Program manager needs to implement locally relevant & focused strategies for early case detection to improve the treatment success, especially in rural area of India
Packaging of RF Mems Switching Functions on Alumina Substrate
Recently the strong demands in wireless communication requires expanding
development for the application of RF MEMS (Radio Frequency micro electro
mechanical systems) sensing devices such as micro-switches, tunable capacitors
because it offers lower power consumption, lower losses, higher linearity and
higher Q factors compared with conventional communications components. To
accelerate commercialisation of RF MEMS products, development for packaging
technologies is one of the most critical issues should be solved beforehand.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Do Health Workers' Preferences Influence their Practices? Assessment of Providers' Attitude and Personal use of new Treatment Recommendations for Management of Uncomplicated Malaria, Tanzania.
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Due to growing antimalarial drug resistance, Tanzania changed malaria treatment policies twice within a decade. First in 2001 chloroquine (CQ) was replaced by sulfadoxine-pyrimethamine (SP) for management of uncomplicated malaria and by late 2006, SP was replaced by artemether-lumefantrine (AL). We assessed health workers' attitudes and personal practices following the first treatment policy change, at six months post-change and two years later. Two cross-sectional surveys were conducted in 2002 and 2004 among healthcare workers in three districts in South-East Tanzania using semi-structured questionnaires. Attitudes were assessed by enquiring which antimalarial was considered most suitable for the management of uncomplicated malaria for the three patient categories: i) children below 5; ii) older children and adults; and iii) pregnant women. Practice was ascertained by asking which antimalarial was used in the last malaria episode by the health worker him/herself and/or dependants. Univariate and multivariate logistic regression was used to identify factors associated with reported attitudes and practices towards the new treatment recommendations. A total of 400 health workers were interviewed; 254 and 146 in the first and second surveys, respectively. SP was less preferred antimalarial in hospitals and private health facilities (p<0.01) in the first round, and the preference worsened in the second round. In the first round, clinicians did not prefer SP for children below age of 5 and pregnant women (p<0.01), but two years later, they did not prefer it for all patient scenarios. SP was the most commonly used antimalarial for management of the last malaria episode for health workers and their dependants in both rounds, in the public sector (p<0.01). Health workers in the dispensaries had the highest odds of using SP for their own treatment [adjusted OR- first round: 6.7 (95%CI: 1.9-23.4); crude OR- second round: 4.5 (1.5-13.3)]. Following changes in malaria treatment recommendations, most health workers did not prefer the new antimalarial drug, and their preferences worsened over time. However, many of them still used the newly recommended drug for management of their own or family members' malaria episode. This indicates that, other factors than providers' attitude may have more influence in their personal treatment practices
Doctors who pilot the GMC's Tests of Competence: who volunteers and why?
Background: Doctors who are investigated by the General Medical Council (GMC) for performance concerns may be required to take a Test of Competence (ToC). The tests are piloted on volunteer doctors before they are used in Fitness to Practise (FtP) investigations. Objectives: To find out who volunteers to take a pilot ToC and why. Methods: This was a retrospective cohort study. Between February 2011 and October 2012 we asked doctors who volunteered for a test to complete a questionnaire about their reasons for volunteering and recruitment. We analysed the data using descriptive statistics and Pearson’s chi-square test. Results: 301 doctors completed the questionnaire. Doctors who took a ToC voluntarily were mostly women, of white ethnicity, of junior grades, working in general practice and who held a Primary Medical Qualification from the UK. This was a different population to doctors under investigation and all registered doctors in the UK. Most volunteers heard about the GMC’s pilot events through email from a colleague and used the experience to gain exam practice for forthcoming postgraduate exams. Conclusions: The reference group of volunteers are not representative of doctors under FtP investigation. Our findings will be used to inform future recruitment strategies with the aim to encourage better matching of groups who voluntarily pilot a ToC with those under FtP investigation
Arab Americans’ Perceptions of Police Post 9/11 in Metropolitan Milwaukee
Arab Americans as individuals tend to avoid any contact with the police because many Arabs shun from contacting police that may lead to community marginalization and alienation. The current literature fails to examine in-depth Arab Americans’ perceptions towards police. The literature typically reflects how police officers view Arab Americans but it is silent regarding how Arab Americans view American police
Theoretical study of photorefractive effect in reduced potassium niobate crystals
Study of photorefractive properties for reduced potassium niobate was performed with using a band model for one impurity center, Which is allowed to study the photoconductivity, to calculate the light induced absorption, to study the space charge field and the exponential gain in the absence of the applied field, as function of the light intensity, the wavelength and the grating spacing. It also allows to study the exponential gain and the phase appear between the space charge field and the illumination as function of the applied field.Study of photorefractive properties for reduced potassium niobate was performed with using a band model for one impurity center, Which is allowed to study the photoconductivity, to calculate the light induced absorption, to study the space charge field and the exponential gain in the absence of the applied field, as function of the light intensity, the wavelength and the grating spacing. It also allows to study the exponential gain and the phase appear between the space charge field and the illumination as function of the applied field
Small Footprint Multilayered Millimeter-Wave Antennas and Feeding Networks for Multi-Dimensional Scanning and High-Density Integrated Systems
This paper overviews the state-of-the-art of substrate integrated waveguide (SIW) techniques in the design and realization of innovative low-cost, low-profile and low-loss (L3) millimeter-wave antenna elements, feeding networks and arrays for various wireless applications. Novel classes of multilayered antenna structures and systems are proposed and studied to exploit the vertical dimension of planar structures to overcome certain limita-tions in standard two-dimensional (2-D) topologies. The developed structures are based on two techniques, namely multi-layer stacked structures and E-plane corners. Differ-ent E-plane structures realised with SIW waveguide are presented, thereby demonstrating the potential of the proposed techniques as in multi-polarization antenna feeding. An array of 128 elements shows low SLL and height gain with just 200g of the total weight. Two versions of 2-D scanning multi-beam are presented, which effectively combine frequency scanning with beam forming networks. Adding the benefits of wide band performance to the multilayer structure, two bi-layer structures are investigated. Different stacked antennas and arrays are demonstrated to optimise the targeted antenna performances in the smallest footprint possible. These structures meet the requirement for developing inexpensive compact millimeter-wave antennas and antenna systems. Different structures and architectures are theoretically and experimentally studied and discussed for specific space- and ground-based appli-cations. Practical issues such as high-density integration and high-volume manufacturability are also addressed
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Vibrational exciton nanoimaging of phases and domains in porphyrin nanocrystals.
Much of the electronic transport, photophysical, or biological functions of molecular materials emerge from intermolecular interactions and associated nanoscale structure and morphology. However, competing phases, defects, and disorder give rise to confinement and many-body localization of the associated wavefunction, disturbing the performance of the material. Here, we employ vibrational excitons as a sensitive local probe of intermolecular coupling in hyperspectral infrared scattering scanning near-field optical microscopy (IR s-SNOM) with complementary small-angle X-ray scattering to map multiscale structure from molecular coupling to long-range order. In the model organic electronic material octaethyl porphyrin ruthenium(II) carbonyl (RuOEP), we observe the evolution of competing ordered and disordered phases, in nucleation, growth, and ripening of porphyrin nanocrystals. From measurement of vibrational exciton delocalization, we identify coexistence of ordered and disordered phases in RuOEP that extend down to the molecular scale. Even when reaching a high degree of macroscopic crystallinity, identify significant local disorder with correlation lengths of only a few nanometers. This minimally invasive approach of vibrational exciton nanospectroscopy and -imaging is generally applicable to provide the molecular-level insight into photoresponse and energy transport in organic photovoltaics, electronics, or proteins
Double precision trajectory program /DPTRAJ 2.2C/
Four part program computes trajectory of space probe moving in solar system and subject to variety of forces
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