19,289 research outputs found

    Mobile Bay turbidity study

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    The termination of studies carried on for almost three years in the Mobile Bay area and adjacent continental shelf are reported. The initial results concentrating on the shelf and lower bay were presented in the interim report. The continued scope of work was designed to attempt a refinement of the mathematical model, assess the effectiveness of optical measurement of suspended particulate material and disseminate the acquired information. The optical characteristics of particulate solutions are affected by density gradients within the medium, density of the suspended particles, particle size, particle shape, particle quality, albedo, and the angle of refracted light. Several of these are discussed in detail

    Chromatographic separation and identification of some peptides in partial hydroylsates of gelatin

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    Recently we have been engaged in a study of the chemical structure of collagen and gelatin with the object of determining the sequence of the amino acid residues in the polypeptide chains of these proteins. In the course of this study we have made considerable progress in the chromatographic analysis of complex mixtures of peptides and we have isolated and identified several simple peptides which occur in partial hydrolysates of gelatin. The initial separation of the mixture into zones of one or more peptides has been made on a column of ion exchange resin; further separation of the peptides in each zone has been achieved by chromatographing in the form of dinitrophenyl (DNP) peptides on columns of silicic acid-Celite. It is to be hoped that the particular combination of chromatographic methods which has been successfully used in the present study will be helpful in the resolution of the complex mixtures which result from the partial hydrolysis of other proteins

    Reflexepileptische Phänomene bei Patienten mit Juveniler Myoklonischer Epilepsie

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    Reflexepileptische Phänomene scheinen bei JME häufig zu sein. 25 JME-Patienten nahmen an einer Video-EEG-Aufzeichnung mit neuropsychologischer Testung (Lesen, Sprechen, Schreiben, Rechnen, Praxis) teil und wurden mit einer Kontrollgruppe verglichen. Bei 10 JME-Patienten wurden epilepsietypische Veränderungen (ETP) oder Anfälle durch Lesen- oder Sprechen induziert. 5 Patienten erlitten ETP oder Anfälle während der Praxis-Induktion, darunter versteht man Anfälle, die durch eine Kombination aus mentalen und manuellen Tätigkeiten ausgelöst werden. Reflexepileptische Phänomene, besonders lese- und sprechausgelöste Anfälle traten gehäuft bei JME-Patienten auf und deuten möglicherweise auf eine genetische Verwandtschaft zu anderen Reflexepilepsien wie der Leseepilepsie hin. Patienten mit JME und reflexepileptischen Anfällen unterscheiden sich nicht wesentlich von den allgemeinen JME-Charakteristika

    Solution of nonlinear algebraic equations characteristic of filter circuits Summary technical report

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    Digital computer program developed for solving nonlinear algebraic equations characteristic of filter circuit

    Optical links in the angle-data assembly of the 70-meter antennas

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    In the precision-pointing mode the 70 meter antennas utilize an optical link provided by an autocollimator. In an effort to improve reliability and performance, commercial instruments were evaluated as replacement candidates, and upgraded versions of the existing instruments were designed and tested. The latter were selected for the Neptune encounter, but commercial instruments with digital output show promise of significant performance improvement for the post-encounter period

    Optical signatures of quantum delocalization over extended domains in photosynthetic membranes

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    The prospect of coherent dynamics and excitonic delocalization across several light-harvesting structures in photosynthetic membranes is of considerable interest, but challenging to explore experimentally. Here we demonstrate theoretically that the excitonic delocalization across extended domains involving several light-harvesting complexes can lead to unambiguous signatures in the optical response, specifically, linear absorption spectra. We characterize, under experimentally established conditions of molecular assembly and protein-induced inhomogeneities, the optical absorption in these arrays from polarized and unpolarized excitation, and demonstrate that it can be used as a diagnostic tool to determine the coherent coupling among iso-energetic light-harvesting structures. The knowledge of these couplings would then provide further insight into the dynamical properties of transfer, such as facilitating the accurate determination of F\"orster rates.Comment: 4 figures and Supplementary information with 7 figures. To appear in Journal of physical chemistry A, 201

    Noninteracting Fermions in infinite dimensions

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    Usually, we study the statistical behaviours of noninteracting Fermions in finite (mainly two and three) dimensions. For a fixed number of fermions, the average energy per fermion is calculated in two and in three dimensions and it becomes equal to 50 and 60 per cent of the fermi energy respectively. However, in the higher dimensions this percentage increases as the dimensionality increases and in infinite dimensions it becomes 100 per cent. This is an intersting result, at least pedagogically. Which implies all fermions are moving with Fermi momentum. This result is not yet discussed in standard text books of quantum statistics. In this paper, this fact is discussed and explained. I hope, this article will be helpful for graduate students to study the behaviours of free fermions in generalised dimensionality.Comment: To appear in European Journal of Physics (2010

    Regular Education Teacher\u27s Perceptions of Inclusion in Virginia

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    Forty regular education teachers responded to a questionnaire concerning regular education teachers·beliefs and perceptions about the benefits. attitudes, and effectiveness of inclusion. The results were analyzed by calculating percentages and means for each item of the questionnaire and by calculating mean scores for each respondent\u27s questionnaire to examine positive or negative reactions to inclusion. In addition. a t-test was computed. The results indicated that regular education teachers who responded were not strongly positive towards _the inclusion of students with disabilities into regular education classrooms. The t-test showed no significant difference between regular education teachers who have students with disabilities included in their classrooms and those teachers who do not have students with disabilities included in their classrooms 60% or more of the day
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