Application of new measurement techniques and strategies to measure ammonia emissions from agricultural activities

Agriculture is the main contributor to the ammonia emissions in the Netherlands. In order to comply with the ammonia emission reduction assigned to the Netherlands, new techniques have been implemented to reduce the ammonia emissions from animal houses, and after application of slurry into the field

Examining the relationship between Supplemental Instruction (SI) and student retention at a doctoral extensive institution

This study tracked 3,286 students over a five-year period who were enrolled in entry-level biology, chemistry, mathematics, and physics courses offering SI in the fall 1999 to see if they were retained or graduated at a Midwestern doctoral extensive institution and identified which predictor variables (demographic, achievement, and level of SI participation) most significantly predicted student retention or graduation. Chi-square analysis, based on two-way contingency tables indicated that SI participants are retained at higher rates than non-SI participants while having lower mean ACT composite scores and fewer semesters of high school preparation in calculus, chemistry, and physics. Backward stepwise multiple logistic regression analysis was used to determine that the most significant predictor of student retention/graduation was high school rank. Positive predictors for the various disciplines across the five year period included the number of SI sessions attended the number of transfer credits earned, and the number of semesters of high school calculus, chemistry, or physics. Negative predictors of student retention or graduation included Pell Grant eligibility and being a member of ethnic minority group.;The results of this study, in addition to making a significant contribution to literature on retention and SI, also have implications for institutional practice. Specifically, this study provides a model for evaluating SI programs or other academic support programs to demonstrate how the program helps retain students. The findings also may be used to inform institutional leaders, policymakers, and the public about how SI is a useful tool to retain students and encourage the expansion of SI programs to meet the needs of additional learners

Anisotropic Strong Coupling Calculation of the Local Electromagnetic Response of High-Tc Superconductors

The electromagnetic response of the CuO2-planes is calculated within a strong coupling theory using model tight binding bands and momentum dependent pairing interactions representing spin fluctuations and phonon exchange. The superconducting state resulting from these interactions has d-wave symmetry. With phonon exchange included the order parameter amplitude grows rapidly below Tc at elevated frequencies which leads to improved agreement with the observed temperature dependence of the penetration depth. Good agreement between theory and experiment can only be achieved if it is assumed that the strength of the quasiparticle interaction decreases with temperature in the superconducting state. The amount of this reduction depends sensitively on the momentum dependence of the interactions, the energy dispersion and the position of the Fermi line.Comment: 3 pages, LaTex, to be published in J.Phys.Chem.Solids, 1997, SNS Conf., Cape Co

Integration of IT in building design and technology: a systems engineering framework

Most concepts of systems engineering (SE) offer a systematic approach to the adaptation of procedures, tools, and standards toward an information-oriented problem in order to analyze, to design, to develop, to manage and to finally implement an effective and a pragmatic integrated information technology solution. This paper proposes a systems engineering framework for integrating information technology (IT) in building design and development. The system view is based on SE good practice and corresponding SE standards. All lifecycle for systems development is covered ranging from the operational concept to operation and maintenance and disposal. The paper is focused mainly at the requirement engineering levels and validation verification issues. In addition, this paper involves a case-study with an important setup where the simulated results are obtained within the use of distributed control and building performance simulation software by run-time coupling. The case-study is also developed in an effective way to illustrate the integration of IT in building design

Development of sets of simplified building models for building simulation

This work proposes a method to manage the complexity of variables involved in building simulation studies and to identify groups of simplified building models suitable to have statistically significant results. The method is described by means of an applicative example, whose aim is the definition of a set of configurations appropriate for the analysis of TRNSYS and EnergyPlus discrepancies in monthly energy needs, hourly peak loads and time of occurrences of hourly peak loads – for both heating and cooling. The proposed procedure for the definition of a reference set of building configurations moves on from the selection of a set of candidate variables describing the building envelope characteristics, paying attention to implications of each choice and to cross-correlations among variables. This is obtained by means of a screening analysis with a simple statistical index (Spearman’s rank correlation coefficient). Two sample sizes are considered in order to evaluate the effects on the selection procedure. For each of the six considered outputs, the most significant group of configuration variables is identified, and the differences among those groups are described