110 research outputs found

    Experimental Study of Natural Convective Flow over a Hot Horizontal Rhombus Cylinder Immersed in Water via PIV Technique

    Get PDF
    Natural convective flow over a horizontal cylinder is a phenomenon used in many industries such as heat transfer from an electrical wire, heat exchanger, pipe heat transfer, etc. In this research, fluid dynamics of natural convective flow over a horizontal rhombus cylinder, with uniform heat flux, is investigated by using two-dimensional Particle Image Velocimetry (PIV) Technique. Experiments are carried out in a cubical tank full of water having an interface with air and the cylinder is placed horizontally inside the tank. The heater is turned on for 40s and the effects of heater's power and the height of water above the cylinder are surveyed. The experiments are carried out in three different heights of water and two different heater’s powers in which Rayleigh number changes from 1.33×107 to 1.76×107. The emitted heat flux causes the buoyancy force to be made and the main branch of flow to be formed. Then, moving up the main branch flow through the stationary water generates two equal anti-direction vortexes. These vortexes are developed when they reach the free surface. The results indicate that the flow pattern changes for different values of water height and heater’s power

    Comparative study of the functional properties of three legume seed isolates: adzuki, pea and soy bean

    Get PDF
    The aim of this work was to compare functional properties including solubility, emulsifying and foaming properties of native and thermally treated adzuki, soy and pea protein isolates prepared under the same conditions. These functional properties were tested at four pH values: pH 3.0, pH 5.0, pH 7.0 and pH 8.0. The lowest solubility at all pH values were obtained for isolate of adzuki whereas isolates of soybean had the highest values at almost all pHs. Thermal treatment reduced solubility of soy and pea isolates at all pH values, whereas solubility of adzuki isolate was unchanged, except at pH 8. Native isolate of adzuki had the best emulsifying properties at pH 7.0 whereas at the other pH values some of native pea and soybean protein isolates were superior. After thermal treatment, depending on tested pH and selected variety all of three species could be a good emulsifier. Native soy protein isolates formed the most stable foams at all pHs. Thermal treatment significantly improved foaming properties of adzuki isolate, whereas reduced foaming capacity of soy and pea isolates, but could improve foam stability of these isolates at specific pH. Appropriate selection of legume seed as well as variety could have great importance in achievement of desirable functional properties of final products. All three tested species could find specific application in wide range of food products

    Outcomes of chronic total occlusion percutaneous coronary intervention from the RAIAN (RAjaie - Iran) registry

    Get PDF
    Objective: While most of the evidence in CTO interventions emerge from Western and Japanese studies, few data have been published up today from the Middle East. Objective of this study was to evaluate technical success rates and clinical outcomes of an Iranian population undergoing CTO PCI in a tertiary referral hospital. Moreover, we sought to evaluate the efficacy of our CTO teaching program. Methods: This is a retrospective single-center cohort study including 790 patients who underwent CTO PCI performed by operators with different volumes of CTOs PCI performed per year. According to PCI result, all patients have been divided into successful (n = 555, 70.3 %) and unsuccessful (n = 235, 29.7 %) groups. Study endpoints were Major Adverse Cardiovascular Events and Health Status Improvement evaluated using the Seattle Angina Questionnaire at one year. Results: A global success rate of 70 % for antegrade and 80 % for retrograde approach was shown despite the lack of some CTO-dedicated devices. During the enrollment period, the success rate increased significantly among operators with a lower number of CTO procedures per year. One-year MACE rate was similar in both successful and unsuccessful groups (13.5 % in successful and 10.6 % in unsuccessful group, p = 0.173). One year patients' health status improved significantly only in successful group. Conclusions: No significant differences of in-hospital and one-year MACE were found between the successful and unsuccessful groups. Angina symptoms and quality of life significantly improved after successful CTO PCI. The RAIAN registry confirmed the importance of operator expertise for CTO PCI success

    More mentoring needed? A cross-sectional study of mentoring programs for medical students in Germany

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Despite increasing recognition that mentoring is essential early in medical careers, little is known about the prevalence of mentoring programs for medical students. We conducted this study to survey all medical schools in Germany regarding the prevalence of mentoring programs for medical students as well as the characteristics, goals and effectiveness of these programs.</p> <p>Methods</p> <p>A definition of mentoring was established and program inclusion criteria were determined based on a review of the literature. The literature defined mentoring as a steady, long-lasting relationship designed to promote the mentee's overall development. We developed a questionnaire to assess key characteristics of mentoring programs: the advocated mentoring model, the number of participating mentees and mentors, funding and staff, and characteristics of mentees and mentors (e.g., level of training). In addition, the survey characterized the mentee-mentor relationship regarding the frequency of meetings, forms of communication, incentives for mentors, the mode of matching mentors and mentees, and results of program evaluations. Furthermore, participants were asked to characterize the aims of their programs. The questionnaire consisted of 34 questions total, in multiple-choice (17), numeric (7) and free-text (10) format. This questionnaire was sent to deans and medical education faculty in Germany between June and September 2009. For numeric answers, mean, median, and standard deviation were determined. For free-text items, responses were coded into categories using qualitative free text analysis.</p> <p>Results</p> <p>We received responses from all 36 medical schools in Germany. We found that 20 out of 36 medical schools in Germany offer 22 active mentoring programs with a median of 125 and a total of 5,843 medical students (6.9 - 7.4% of all German medical students) enrolled as mentees at the time of the survey. 14 out of 22 programs (63%) have been established within the last 2 years. Six programs (27%) offer mentoring in a one-on-one setting. 18 programs (82%) feature faculty physicians as mentors. Nine programs (41%) involve students as mentors in a peer-mentoring setting. The most commonly reported goals of the mentoring programs include: establishing the mentee's professional network (13 programs, 59%), enhancement of academic performance (11 programs, 50%) and counseling students in difficulties (10 programs, 45%).</p> <p>Conclusions</p> <p>Despite a clear upsurge of mentoring programs for German medical students over recent years, the overall availability of mentoring is still limited. The mentoring models and goals of the existing programs vary considerably. Outcome data from controlled studies are needed to compare the efficiency and effectiveness of different forms of mentoring for medical students.</p

    The do's, don't and don't knows of supporting transition to more independent practice

    Get PDF
    Introduction: Transitions are traditionally viewed as challenging for clinicians. Throughout medical career pathways, clinicians need to successfully navigate successive transitions as they become progressively more independent practitioners. In these guidelines, we aim to synthesize the evidence from the literature to provide guidance for supporting clinicians in their development of independence, and highlight areas for further research. Methods: Drawing upon D3 method guidance, four key themes universal to medical career transitions and progressive independence were identified by all authors through discussion and consensus from our own experience and expertise: workplace learning, independence and responsibility, mentoring and coaching, and patient perspectives. A scoping review of the literature was conducted using Medline database searches in addition to the authors’ personal archives and reference snowballing searches. Results: 387 articles were identified and screened. 210 were excluded as not relevant to medical transitions (50 at title screen; 160 at abstract screen). 177 full-text articles were assessed for eligibility; a further 107 were rejected (97 did not include career transitions in their study design; 10 were review articles; the primary references of these were screened for inclusion). 70 articles were included of which 60 provided extractable data for the final qualitative synthesis. Across the four key themes, seven do’s, two don’ts and seven don’t knows were identified, and the strength of evidence was graded for each of these recommendations. Conclusion: The two strongest messages arising from current literature are first, transitions should not be viewed as one moment in time: career trajectories are a continuum with valuable opportunities for personal and professional development throughout. Second, learning needs to be embedded in practice and learners provided with authentic and meaningful learning opportunities. In this paper, we propose evidence-based guidelines aimed at facilitating such transitions through the fostering of progressive independence

    The hidden curriculum and integrating cure- and care-based approaches to medicine

    Get PDF
    Although current literature about the “cure versus care” issue tends to promote a patient-centered approach, the disease-centered approach remains the prevailing model in practice. The perceived dichotomy between the two approaches has created a barrier that could make it difficult for medical students and physicians to integrate psychosocial aspects of patient care into the prevailing disease-based model. This article examines the influence of the formal and hidden curricula on the perception of these two approaches and finds that the hidden curriculum perpetuates the notion that “cure” and “care” based approaches are dichotomous despite significant changes in formal curricula that promote a more integrated approach. The authors argue that it is detrimental for clinicians to view the two approaches as oppositional rather than complementary and attempt to give recommendations on how the influence of the hidden curriculum can be reduced to get a both-cure-and-care-approach, rather than an either-cure-or-care-approach

    Medicinal plants – prophylactic and therapeutic options for gastrointestinal and respiratory diseases in calves and piglets? A systematic review

    Full text link

    DETECTION OF THE L2ΦL'^{2}\Phi STATE OF NO

    No full text
    1^{1}M. Chergul, V. Chandrasekharan, W. Bohmer, R. Haensel, H. Wilcke, and N. Schwentner, Chem. Phys. Lett. 105, 386 (1984). 2^{2}M. Huber, Helv. Phys. Acta, 37, 329 (1964).Author Institution: Chemical Physics Laboratory, SRI International; Chemical Physics Laboratory, SRI InternationalBy using the techniques of stimulated emission pumping combined with fluorescence dip spectroscopy it has been possible to characterize the getastable NO(L^{\prime}^{2}\Phi) state. The spectroscopic parameters are: Te=53740.81±0.20cm1re=1.4204±0.0037A˚ωe=999.36±0.18cm1ωexe=9.92±0.03cm1Be=1.1189±0.0029cm1αe=0.019±0.0027cm1A=42.480±0.0320.310±0.035(v+1/2)cm1 \begin{array}{ll} T_{e}=53740.81\pm0.20 cm^{-1} & r_{e} = 1.4204\pm 0.0037 \textrm{\AA}\\ \omega_{e} = 999.36\pm 0.18 cm^{-1} & \omega_{e} x_{e} = 9.92\pm 0.03 cm^{-1}\\ B_{e} = 1.1189 \pm 0.0029 cm^{-1} & \alpha_{e} = 0.019\pm 0.0027 cm^{-1}\\ A = -42.480\pm 0.032-0.310\pm 0.035(v+1/2) cm^{-1} & \end{array} The state is produced by initially populating NO(B^{\prime}^{2}_{\Delta_{5/2}}, v = 3, J= 7.5) with 157.630 on radiation from an F2F_{2} laser. While observing the BXB^{\prime}-X fluocescence emission, a Raman-shifted dye laser is tuned through the appropriate spectral regions (950-1300 nm), and intensity decreases are observed at the positions of the J = 6.5, 7.5, and 8.5 rotational levels of the 2Φ^{2}\Phi state (as well as other states). The first four vibrational levels have been detected in this manner, with the numbering being confirmed by the recent matrix isolation detection of v=0 by Chergui et al.1al.^{1} Perturbations in the v=1 level of the B^{\prime}^{2}\Delta state, postulated by Huber2Huber^{2} as being due to the L^{\prime}^{2}\Phi state, are shown to involve the v=9 level. Supported by the National Science Foundatio
    corecore