2,291 research outputs found

    Hysteresis Motor Driven One Axis Magnetically Suspended Reaction Sphere

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    The Attitude and Orbit Control System (AOCS) plays an essential role in the flight control of a spacecraft. This system usually contains a minimum of three reaction wheels (often 4-5 wheels are used for optimization and redundancy). By accelerating the appropriate wheels, the system can produce a zero-mean reaction torque about any axis to the spacecraft, which enables the spacecraft to maneuver on orbit. Meanwhile, the momentum generated by acceleration can be stored in the wheels.Lincoln Laboratory. Advanced Concepts Committe

    Comparing of emotional intelligence in bright talents and non-talented students in Golestan university of medical sciences

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    هوش هیجانی دیدگاه جدیدی درباره پیش‏بینی عوامل مؤثر بر موفقیت افراددرجامعه را فراهم میسازد. هوش عمومی دربهترین شرایط، تنهاعامل بیست درصدازموفقیت‏های زندگی است. هشتاد درصد موفقیت‏ها به عوامل دیگر از جمله هوش هیجانی وابسته است. درنظام آموزشي ما، اين مشكل وجود دارد كه برهوش شناختی تأكيد و هوش هيجاني كه بي اندازه درسرنوشت افراد اهميت دارند، ناديده گرفته مي شود. این مطالعه به مقایسه هوش هیجانی دانشجویان استعداددرخشان وغیراستعداددرخشان می پردازد. Background and Objective: Emotional Intelligence provides a new perspective to anticipate effective factors on people's success in a society. Cognitive Intelligence, in its best context, is the cause of 20 percent of people's success in their life. 80 percent of success depends on other factors like Emotional Intelligence.In our educational system there is more emphasis on cognitive intelligence than emotional intelligence. Therefore, as EQ is of paramount importance in people's future, this study investigated a comparison between talented and normal students regarding Emotional Intelligence. Materials and Methods: This sectional descriptive study had an analytical approach between two groups and was conducted in 1392 on students of Golestan University of Medical Sciences. 152 students, including 41talented and 111 normal students participated in this study. Instrument of collecting data included a questionnaire with 133 Questions about Emotional Intelligence with N-bar normalization and demographic and educational specification. Analysis of data was performed by ANOVA, T-test and Kruskal Wallis. Results: Findings showed that an average EQ of talented students was 77.103 and that of normal ones was 41.98. Comparison test and T-test showed that there was no significant difference in EQ of students between the two groups (P= 00085). In self-actualization component, there was a meaningful significance between talented and normal students (P=0.004). As a whole, it was worth to note that there was a meaningful difference regarding EQ among talented students with educated fathers (P=0.046). It was also shown that there was a meaningful difference regarding EQ among normal students with educated fathers (P=0.04). Conclusion: Results showed that there was no significant difference regarding EQ between talented and normal students. So it can be said that being talented could not be the only factor to have higher abilities. It is proposed that in measuring talented students' abilities, not only cognitive intelligence but also EQ which causes more than 80 percent of peoples' success in a society should be considered

    فراوانی مصرف داروهای بدون نسخه و عوامل مرتبط در دانشجویان علوم پزشکی گلستان

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    The Prevalence of Non-Prescription Drugs and Related Factors in Students of Medical Sciences In this descriptive cross- sectional study using convince sampling 262 of the students were participated. The data collected by valid and reliable questionnaire consisted two parts; demographic and specific questions related to medication consumption. The data analyzed using SPSS.16 and interpreted by Chi-Square and T-Test

    Evaluation methods used on health information systems (HISs) in Iran and the effects of HISs on Iranian healthcare: a systematic review.

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    OBJECTIVES: The most important goal of a health information system (HIS) is improvement of quality, effectiveness and efficiency of health services. To achieve this goal, health care systems should be evaluated continuously. The aim of this paper was to study the impacts of HISs in Iran and the methods used for their evaluation. METHODS: We systematically searched all English and Persian papers evaluating health information systems in Iran that were indexed in SID, Magiran, Iran medex, PubMed and Embase databases until June 2013. A data collection form was designed to extract required data such as types of systems evaluated, evaluation methods and tools. RESULTS: In this study, 53 out of 1103 retrieved articles were selected as relevant and reviewed by the authors. This study indicated that 28 studies used questionnaires to evaluate the system and in 27 studies the study instruments were distributed within a research population. In 26 papers the researchers collected the information by means of interviews, observations, heuristic evaluation and the review of documents and records. The main effects of the evaluated systems in health care settings were improving quality of services, reducing time, increasing accessibility to information, reducing costs and decreasing medical errors. CONCLUSION: Evaluation of health information systems is central to their development and enhancement, and to understanding their effect on health and health services. Despite numerous evaluation methods available, the reviewed studies used a limited number of methods to evaluate HIS. Additionally, the studies mainly discussed the positive effects of HIS on health care services

    Prioritizing barriers to successful implementation of hospital information systems.

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    Hospital information systems (HIS) are often implemented to enhance the quality of care, as well as to improve the efficiency and safety of health care services. However, there are various barriers for their successful implementation. The aim of this paper is to prioritize these barriers. This research is a cross sectional analytic-descriptive study. The study populations were hospital managers, IT department administrators, and clinical supervisors at the academic and non-academic hospitals of two cities in Iran. The data was collected by a questionnaire that its content validity was confirmed by three specialists. Its reliability was confirmed using Cronbach's alpha (α = 0.78). Questionnaire contained five dimensions and 39 implementation barriers. The collected data was analyzed by descriptive and analytical statistics using the Kendall Rank Correlation Coefficient and Chi2 tests. The findings of the study revealed that lack of powerful information networks, error in data entry, technical problems related to system design, lack of organizational training, lack of users' knowledge about system and working with it, and negative attitudes of providers and patients toward systems are the most important barriers of HIS implementation. Prioritizing of these barriers helps policy makers to decide what to do when planning for HIS utilization

    The ortho-to-para ratio of ammonia in the L1157 outflow

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    We have measured the ortho-to-para ratio of ammonia in the blueshifted gas of the L1157 outflow by observing the six metastable inversion lines from (J, K) = (1, 1) to (6, 6). The highly excited (5, 5) and (6, 6) lines were first detected in the low-mass star forming regions. The rotational temperature derived from the ratio of four transition lines from (3, 3) to (6, 6) is 130-140 K, suggesting that the blueshifted gas is heated by a factor of ~10 as compared to the quiescent gas. The ortho-to-para ratio of the NH3 molecules in the blueshifted gas is estimated to be 1.3--1.7, which is higher than the statistical equilibrium value. This ratio provides us with evidence that the NH3 molecules have been evaporated from dust grains with the formation temperature between 18 and 25 K. It is most likely that the NH3 molecules on dust grains have been released into the gas phase through the passage of strong shock waves produced by the outflow. Such a scenario is supported by the fact that the ammonia abundance in the blueshifted gas is enhanced by a factor of ~5 with respect to the dense quiescent gas.Comment: 16 pages, including 3 PS figures. To appear in the ApJ (Letters). aastex macro

    Formation of Small-Scale Condensations in the Molecular Clouds via Thermal Instability

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    A systematic study of the linear thermal instability of a self-gravitating magnetic molecular cloud is carried out for the case when the unperturbed background is subject to local expansion or contraction. We consider the ambipolar diffusion, or ion-neutral friction on the perturbed states. In this way, we obtain a non-dimensional characteristic equation that reduces to the prior characteristic equation in the non-gravitating stationary background. By parametric manipulation of this characteristic equation, we conclude that there are, not only oblate condensation forming solutions, but also prolate solutions according to local expansion or contraction of the background. We obtain the conditions for existence of the Field lengths that thermal instability in the molecular clouds can occur. If these conditions establish, small-scale condensations in the form of spherical, oblate, or prolate may be produced via thermal instability.Comment: 16 page, accepted by Ap&S

    Molecular Tracers of the Central 12 pc of the Galactic Center

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    We have used the BIMA array to image the Galactic Center with a 19-pointing mosaic in HCN(1-0), HCO+(1-0), and H 42-alpha emission with 5 km/s velocity resolution and 13'' x 4'' angular resolution. The 5' field includes the circumnuclear ring (CND) and parts of the 20 and 50 km/s clouds. HCN(1-0) and HCO+ trace the CND and nearby giant molecular clouds while the H 42-alpha emission traces the ionized gas in Sgr A West. We find that the CND has a definite outer edge in HCN and HCO+ emission at ~45'' radius and appears to be composed of two or three distinct streams of molecular gas rotating around the nucleus. Outside the CND, HCN and HCO+ trace dense clumps of high-velocity gas in addition to optically thick emission from the 20 and 50 km/s clouds. A molecular ridge of compressed gas and dust, traced in NH3 emission and self-absorbed HCN and HCO+, wraps around the eastern edge of Sgr A East. Just inside this ridge are several arcs of gas which have been accelerated by the impact of Sgr A East with the 50 km/s cloud. HCN and HCO+ emission trace the extension of the northern arm of Sgr A West which appears to be an independent stream of neutral and ionized gas and dust originating outside the CND. Broad line widths and OH maser emission mark the intersection of the northern arm and the CND. Comparison to previous NH3 and 1.2mm dust observations shows that HCN and HCO+ preferentially trace the CND and are weaker tracers of the GMCs than NH3 and dust. We discuss possible scenarios for the emission mechanisms and environment at the Galactic center which could explain the differences in these images.Comment: 24 pages, including 17 figures; to appear in The Astrophysical Journa

    Probing the structure of a birthplace of intermediate-mass stars: Ammonia cores in Lynds 1340

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    Lynds 1340, a molecular cloud forming intermediate-mass stars, has been mapped in the NH_3(1,1) and (2,2) transitions with the Effelsberg 100m telescope. We observed the whole area of the cloud where C18O emission was detected earlier, at a 40 arcsec grid, with additional positions towards the C18O peaks and optically invisible IRAS point sources. Our observations covered an area of 170 arcmin^2, corresponding to about 5.15 pc^2 at a distance of 600 pc, and revealed 10 ammonia cores. The cores, occupying some 7% of the mapped area, probably represent the highest density regions of L1340. Their total mass is 80 solar mass, about 6% of the mass traced by C18O. Six cores are associated with optically invisible IRAS point sources. Their average nonthermal line width is 0.78 kms^{-1}, while the same quantity for the four starless cores is 0.28 kms^{-1}. We suggest that the narrow-line cores are destined to form low-mass stars, whereas small groups of intermediate-mass stars are being formed in the turbulent cores. The features traced by NH_3, 13CO, C18O and HI obey the line width-size relation log Delta v_{NT} = 0.41(0.06)log R_{1/2}+ 0.12(0.06). Comparison of sizes, densities and nonthermal line widths of ammonia cores with those of C18O and 13CO structures supports the scenario in which core formation has been induced by turbulent fragmentation. The typical physical properties of the ammonia cores of L1340, R_{1/2} =0.08 pc, T_{kin}=13.8 K, Delta v_{total}=0.64 kms^{-1}, and M =9 solar mass are close to those of the high-mass star forming Perseus and Orion B clouds.Comment: 13 pages, 11 figures. Accepted by A&

    Systematic Molecular Differentiation in Starless Cores

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    (Abridged) We present evidence that low-mass starless cores, the simplest units of star formation, are systematically differentiated in their chemical composition. Molecules including CO and CS almost vanish near the core centers, where the abundance decreases by one or two orders of magnitude. At the same time, N2H+ has a constant abundance, and the fraction of NH3 increases toward the core center. Our conclusions are based on a study of 5 mostly-round starless cores (L1498, L1495, L1400K, L1517B, and L1544), which we have mappedin C18O(1-0), C17O(1-0), CS(2-1), C34S(2-1), N2H+(1-0), NH3(1,1) and (2,2), and the 1.2 mm continuum. For each core we have built a model that fits simultaneously the radial profile of all observed emission and the central spectrum for the molecular lines. The observed abundance drops of CO and CS are naturally explained by the depletion of these molecules onto dust grains at densities of 2-6 10^4 cm-3. N2H+ seems unaffected by this process up to densities of several 10^5, while the NH3 abundance may be enhanced by reactions triggered by the disappearance of CO from the gas phase. With the help of our models, we show that chemical differentiation automatically explains the discrepancy between the sizes of CS and NH3 maps, a problem which has remained unexplained for more than a decade. Our models, in addition, show that a combination of radiative transfer effects can give rise to the previously observed discrepancy in the linewidth of these two tracers. Although this discrepancy has been traditionally interpreted as resulting from a systematic increase of the turbulent linewidth with radius, our models show that it can arise in conditions of constant gas turbulence.Comment: 25 pages, 9 figures, accepted by Ap
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