418 research outputs found

    Residual circulations calculated from satellite data: Their relations to observed temperature and ozone distributions

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    Monthly mean residual circulations were calculated from eight years of satellite data. The diabatic circulation is usually found to give a good approximation to the residual circulation, but this is not always the case. In particular, an example is shown at 60 deg S and 30 mbar where the diabatic and residual circulations show very different annual variations. Correlations between the vertical component of the residual circulation and temperature and ozone were computed. The computations indicate that yearly variations of temperatures in the tropics are under radiative control, except during stratospheric warmings. Interannual variations in seasonal mean temperatures are shown to be under dynamical control everywhere. Correlations between seasonal means of the vertical component of the residual circulation and ozone mixing ratios are consistent with what would be expected from the ozone variations being due to differences in the ozone transport, although transport effects cannot easily be distinguished from photochemical effects above the altitude of the ozone mixing ratio peak. Finally, variations in total ozone are examined in comparison with residual circulation variations. A one to two month phase lag is seen in the annual variation in the total ozone at 60 deg N with respect to the maximum downward residual motions. This phase lag is greater at 60 deg N than at 60 deg S. There is evidence at 60 deg S of a greater downward trend in the mean zonal ozone maxima than there is in the minima. A decreasing trend in the maximum descending motion is seen to accompany the ozone trend at 60 deg S

    Comparison of the poleward transport of ozone in the Northern and Southern Hemispheres

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    Six and one-half years of ozone data and temperature data are used to extend Geller et al.'s (1988) study comparing the transport of ozone to high latitudes in the Northern and Southern Hemispheres. In this earlier study, it was pointed out that the poleward transport of ozone varies annually in the Northern Hemisphere but has a marked semiannual behavior in the Southern Hemisphere. This earlier study covered the period from December 1978 to November 1982. Two and one-half additional years have now been analyzed so that the analysis now extends to July 1986. With this extended data set, the maximum rate of increase in total ozone is seen to occur in January in the Northern Hemisphere for all of the years investigated. In the Southern Hemisphere, the maximum rate of increase is seen in September for almost all of the years with a secondary maximum in the rate of increase in total ozone often being seen during March-April period. The nature of the seasonal variation in total ozone is found to be much more variable in the Southern Hemisphere than in the Northern Hemisphere

    Designing Teacher Professional Development for Mathematics Teaching with Variation Theory

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    In this study, we aimed at demonstrating the power of Variation Theory in exploring the local situation of Indonesian teachers and Teacher Professional Development program. The projection of Variation theory regarding the enterprise of teaching results on the need of sensitivity of students and exemplary teaching strategy that differ with teachers teaching style. Besides, It requires more opportunities for teachers to understand the critical feature of object of learning. By sequence of activity that elaborating variation theory and regards the local situation might imply the improvement of students learning

    A Review of Dynamic Datasets for Facial Expression Research

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    Temporal dynamics have been increasingly recognized as an important component of facial expressions. With the need for appropriate stimuli in research and application, a range of databases of dynamic facial stimuli has been developed. The present article reviews the existing corpora and describes the key dimensions and properties of the available sets. This includes a discussion of conceptual features in terms of thematic issues in dataset construction as well as practical features which are of applied interest to stimulus usage. To identify the most influential sets, we further examine their citation rates and usage frequencies in existing studies. General limitations and implications for emotion research are noted and future directions for stimulus generation are outlined

    Portable Domestic Refrigerator: A Design Approach

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    This project work is designed mainly for the preservation of foodstuffs, storing of medicines and the cooling of water and drinking fluids in our homes and offices. In the choice of the necessary parameters for the design, Dichlorodifluoromethane, Freone (R12) is used as the refrigerant. An evaporating pressure of 1.237 bar and condensing pressure of 13.66 bar and corresponding temperatures of -25°c and 55°c was considered and the volume of the inside of the refrigerator was fixed at O.2m3 (200litres). The power of the compressor of the refrigerator is 46W. The cooling load as estimated has been assumed and coefficient of performance was calculated arid the various design components such as the compressor, condenser, capillary tube were analyzed. The parameters have indeed facilitated the successful design of this refrigerator. Keywords: Refrigerator, Compressor, Condenser, Evaporator, Expansion devic

    Similarities and divegences of six giant clams Tridacna maxima populations from two French Polynesia archipelagoes.

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    国際共同シンポジウム: International Joint Symposium: Tropical Island Ecosystems and Sustainable Development (Moorea, French Polynesia), DATE:December 2-7, 2006, PLACE: Moorea, French Polynesia, CO-SPONSORS: Centre de Recherches Insulaires et Observatoire de l’Environnement (CRIOBE) / Richard B. Gump South Pacific Research Station (University of California Berkeley) / 21st COE Program of University of the Ryukyus論文http://purl.org/coar/resource_type/c_579

    Topside ionosphere electron density concentration: observation and theory.

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    Thesis (Ph D.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1970.Vita.Bibliography: leaves 188-197.Ph D

    Design, fabrication, and characterization of complex, multilayer heterostructures of conjugated and non-conjugated polymers via molecular self-assembly

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1995.Includes bibliographical references.by Augustine Che-Tsung Fou.Ph.D

    Extra-corporeal membrane oxygenation for refractory cardiogenic shock after adult cardiac surgery:a systematic review and meta-analysis

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    Background - Postcardiotomy cardiogenic shock (PCCS) refractory to inotropic support and intra-aortic balloon pump (IABP) occurs rarely but is almost universally fatal without mechanical circulatory support. In this systematic review and meta-analysis we looked at the evidence behind the use of veno-arterial extra-corporeal membrane oxygenation (VA ECMO) in refractory PCCS from a patient survival rate and determinants of outcome viewpoint. Methods - A systematic review was performed in January 2017 using PubMed (with no defined time period) using the keywords “postcardiotomy”, “cardiogenic shock”, “extracorporeal membrane oxygenation” and “cardiac surgery”. We excluded papers pertaining to ECMO following paediatric cardiac surgery, medical causes of cardiogenic shock, as well as case reports, review articles, expert opinions, and letters to the editor. Once the studies were collated, a meta-analysis was performed on the proportion of survivors in those papers that met the inclusion criteria. Meta-regression was performed for the most commonly reported adverse prognostic indicators (API). Results - We identified 24 studies and a cumulative pool of 1926 patients from 1992 to 2016. We tabulated the demographic data, including the strengths and weaknesses for each of the studies, outcomes of VA ECMO for refractory PCCS, complications, and APIs. All the studies were retrospective cohort studies. Meta-analysis of the moderately heterogeneous data (95% CI 0.29 to 0.34, p 70 years, 95% CI −0.057 to 0.001, P = 0.058), and long ECMO support (95% CI −0.068 to 0.166, P = 0.412). Postoperative renal failure, high EuroSCORE (>20%), diabetes mellitus, obesity, rising lactate whilst on ECMO, gastrointestinal complications had also been reported. Conclusion - Haemodynamic support with VA ECMO provides a survival benefit with reasonable intermediate and long-term outcomes. Many studies had reported advanced age, renal failure and prolonged VA ECMO support as the most likely APIs for VA ECMO in PCCS. EuroSCORE can be utilized to anticipate the need for prophylactic perioperative VA ECMO in the high-risk category. APIs can be used to aid decision-making regarding both the institution and weaning of ECMO for refractory PCCS
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