The Process of Becoming a Blue Ribbon School: Perceptions of Participating Teachers And Principals

The purpose of this study was to examine and analyze the shared experiences of teachers and principals within selected schools in their quest of achieving the United States Department of Education Blue Ribbon School of Excellence Award in Georgia. In one sense, these schools are already successful. They were required to document five consecutive years of high and improving test scores as a prerequisite for consideration. Therefore, an attempt to better understand a process that could lead to continuous improvement and change in schools, as deemed necessary, was the fulcrum upon which this study rests. The researcher applied a theoretical framework to help explicate narratives drawn from participants. Principals were interviewed and collaborative school teams participated in focus groups. Research protocol questions guided the interviews to elicit responses relating to the seven research sub-questions to derive rich narratives. The qualitative data from the taped interviews were analyzed using the QSR NUD.IST 5 software program, which aided the researcher in categorizing the interviewees\u27 responses to the interview questions and, more importantly, identifying recurring themes, related ideas and responses pertinent to the purpose of the study. Narratives resulting from these procedures became the primary sources of data within this design. Several conclusions emerged from this study. In all cases, the Blue Ribbon School process reduced isolation and strengthened teamwork, collegiality and school pride within the group of interviewees. These attributes were closely akin to discussions of school climate and were reinforced through the retelling of stories. The process encouraged an integrated, holistic view of the school, particularly for team members who actively participated in preparing the application. Principals and school teams believed that by working together in a goal-oriented process such as the one found in the Blue Ribbon School program, they were able to glean a broader, more meaningful view of their school and agreed that a student focus was the driving force for the school\u27s aims and actions

Background optimization for the neutron Ttime of flight spectrometer NEAT

The neutron time of flight spectrometer NEAT at BER II is currently undergoing a major upgrade where an important aspect is the prevention of parasitic scattering to enhance the signal to noise ratio. Here, we discuss the impact of shielding to suppress parasitic scattering from two identified sources of background the sample environment and detector tubes. By means of Monte Carlo simulations and a modification of the analytical model of Copley et al. [Copley and Cook, 1994], the visibility functions of instrument parts are computed for different shielding configurations. According to three selection criteria, namely suppression of background, transmission and detection limit, the parameters of an oscillating radial collimator are optimized for NEAT s default setup. Moreover, different configurations of detector shielding are discussed to prevent cross talk within the radial detector syste

From soft harmonic phonons to fast relaxational dynamics in CH3_{3}NH3_{3}PbBr3_{3}

The lead-halide perovskites, including CH$_{3}$NH$_{3}$PbBr$_{3}$, are components in cost effective, highly efficient photovoltaics, where the interactions of the molecular cations with the inorganic framework are suggested to influence the electronic and ferroelectric properties. CH$_{3}$NH$_{3}$PbBr$_{3}$ undergoes a series of structural transitions associated with orientational order of the CH$_{3}$NH$_{3}$ (MA) molecular cation and tilting of the PbBr$_{3}$ host framework. We apply high-resolution neutron scattering to study the soft harmonic phonons associated with these transitions, and find a strong coupling between the PbBr$_{3}$ framework and the quasistatic CH$_{3}$NH$_{3}$ dynamics at low energy transfers. At higher energy transfers, we observe a PbBr$_{6}$ octahedra soft mode driving a transition at 150 K from bound molecular excitations at low temperatures to relatively fast relaxational excitations that extend up to $\sim$ 50-100 meV. We suggest that these temporally overdamped dynamics enables possible indirect band gap processes in these materials that are related to the enhanced photovoltaic properties.Comment: (main text - 5 pages, 4 figures; supplementary information - 3 pages, 3 figures

Triphilic ionic-liquid mixtures: fluorinated and non-fluorinated aprotic ionic-liquid mixtures

We present here the possibility of forming triphilic mixtures from alkyl- and fluoroalkylimidazolium ionic liquids, thus, macroscopically homogeneous mixtures for which instead of the often observed two domainspolar and nonpolarthree stable microphases are present: polar, lipophilic, and fluorous ones. The fluorinated side chains of the cations indeed self-associate and form domains that are segregated from those of the polar and alkyl domains. To enable miscibility, despite the generally preferred macroscopic separation between fluorous and alkyl moieties, the importance of strong hydrogen bonding is shown. As the long-range structure in the alkyl and fluoroalkyl domains is dependent on the composition of the liquid, we propose that the heterogeneous, triphilic structure can be easily tuned by the molar ratio of the components. We believe that further development may allow the design of switchable, smart liquids that change their properties in a predictable way according to their composition or even their environment

Liquid Structure Scenario of the Archetypal Supramolecular Deep Eutectic Solvent: Heptakis(2,6-di-O-methyl)-β-cyclodextrin/levulinic Acid

The concept of supramolecular solvents has been recently introduced, and the extended liquid-state window accessible for mixtures of functionalized cyclodextrins (CDs) with hydrogen bond (HB) donor species, e.g., levulinic acid, led to the debut of supramolecular deep eutectic solvents (SUPRA-DES). These solvents retain CD’s inclusion ability and complement it with enhanced solvation effectiveness due to an extended HB network. However, so far, these promising features were not rationalized in terms of a microscopic description, thus hindering a more complete capitalization. This is the first joint experimental and computational study on the archetypal SUPRA-DES: heptakis- (2,6-di-O-methyl)-β-CD/levulinic acid (1:27). We used X-ray scattering to probe CD’s aggregation level and molecular dynamics simulation to determine the nature of interactions between SUPRA-DES components. We discover that CDs are homogeneously distributed in bulk and that HB interactions, together with the electrostatic ones, play a major role in determining mutual interaction between components. However, dispersive forces act in synergy with HB to accomplish a fundamental task in hindering hydrophobic interactions between neighbor CDs and maintaining the system homogeneity. The mechanism of mutual solvation of CD and levulinic acid is fully described, providing fundamental indications on how to extend the spectrum of SUPRA-DES combinations. Overall, this study provides the key to interpreting structural organization and solvation tunability in SUPRA-DES to extend the range of sustainable applications for these new, unique solvents

Ready to Use Detector Modules for the NEAT Spectrometer Concept, Design, First Results

The paper presents the detector system developed by Datalist Systems, Ltd. previously ANTE Innovative Technologies for the NEAT II spectrometer at HZB. We present initial concept, design and implementation highlights as well as the first results of measurements such as position resolution. The initial concept called for modular architecture with 416 3He detector tubes organized into thirteen 32 tube modules that can be independently installed and removed to and from the detector vacuum chamber for ease of maintenance. The unalloyed aluminum mechanical support modules for four 8 tube units each also house the air boxes that contain the front end electronics preamplifiers that need to be on atmospheric pressure. The modules have been manufactured and partly assembled in Hungary and then fully assembled and installed on site by Datalist Systems crew. The signal processing and data acquisition solution is based on low time constant 60 ns preamplifier electronics and sampling ADC s running at 50 MS s i.e. a sample every 20 ns for all 832 data channels. The preamplifiers are proprietary, developed specifically for the NEAT spectrometer, while the ADC s and the FPGA s that further process the data are based on National Instruments products. The data acquisition system comprises 26 FPGA modules each serving 16 tubes providing for up to 50 kHz count rate per individual tube and it is organized into two PXI chassis and two data acquisition computers that perform post processing, event classification and provide appropriate preview of the collected data. The data acquisition software based on Event Recording principles provides a single point of contact for the scientific software with an Event Record List with absolute timestamps of 100ns resolution, timing data of 100 ns resolution for the seven discs chopper system as well as classification data that can be used for flexible data filtering in off line analysis of the gathered data. A unique 3 tier system of filtering criteria of events is in operation a hard threshold in the FPGA s to reduce the effect of noise, a pulse shape based classification to eliminate gamma sensitivity and an additional flexible feature based classification to filter out pileup and other unwanted phenomena. This ensures high count rates 50kHz per tube, 1MHz overall while maintaining good quality of measurements e.g. position resolution .The first measurement results show that the delivered detector system meets the initial requirements of 20 mm position resolution along the 2000mm long detector tubes. This is partly due to the innovative event classification system that provides vital pulse shape data that can be used for sophisticated position resolution algorithms implemented on the DAQ computer

Потоковый и эластичный трафик в сетях с топологией Клоса

Rapid progress in telecommunications which started in the end of 20th century raises new teletraffic problems. The result of the convergence of different networks stems that set of different traffic types should be served by the system. These types differ by their characteristics, in network bandwidth and Quality of Service (QoS) requirements. Diverse consumer needs, variety of on-line services and high-speed Internet access joined in the same system generate large amount of traffic most part of which includes elastic traffic. Multi-rate communication systems, developed at the beginning of 21th century as a result of engineering progress, are able to serve elastic traffic with variable rate depending on the number of prioritized streaming requests being processed in parallel. Specific characteristics of elastic traffic do not allow us to use Erlang multi-rate loss model for simulation of modern telecommunication systems. This paper concerns Erlang-like multi-service loss model of an adaptive multi-rate system for streaming and elastic traffic, where a set of bandwidth requirements corresponds to each type of elastic traffic. A bandwidth requirement is assigned to an entered elastic request depending on occupied bandwidth. The results obtained in the paper are applied to calculation of QoS parameters of the Closs network topology which is widely used in modern switching networks.Быстрый прогресс высоких технологий в сфере телекоммуникаций, начавшийся с конца 20 в., ставит перед теорией телетрафика новые задачи. Конвергенция сетей различных типов породила множество классов сетевого трафика, которые различаются своими характеристиками, объемом необходимых сетевых ресурсов, а также требованиями к качеству обслуживания. Наличие разнородных потребительских запросов в сочетании с множеством предоставляемых интерактивных услуг и высокоскоростным доступом в интернет приводит к необходимости совместного обслуживания различных классов трафика, большую долю которого составляет эластичный трафик. На рубеже 20 и 21 вв. технический прогресс привел к появлению многоскоростных систем передачи, позволяющих обслуживать эластичные потоки заявок с переменной скоростью, зависящей от того, сколько на данном отрезке времени одновременно с этим обслуживается приоритетных потоковых заявок. Применение классической мультисервисной модели Эрланга для расчетов параметров качества обслуживания в современных системах становится затруднительным в силу специфических особенностей эластичного трафика. В работе представлена мультисервисная модель адаптивной многоскоростной системы типа Эрланга с потоковым и эластичным трафиком, где последнему соответствует целый набор требований к ширине полосы пропускания (ШПП). Требование к ШПП устанавливается при поступлении эластичной заявки в зависимости от занятого передаточного ресурса. Результаты модели применяются в анализе ВВХ сети с топологией Клоса, которая находит широкое применение в современных сетях телекоммуникаций