Payload crew utilization for spacelab missions

Planned payload crew utilization on Spacelab mission are analyzed to establish trends and guidelines. The study included missions that have flow to date as well as those in planning. Available data were analyzed on the basis of four major timeline iterations that occur during mission design. Data were categorized and assessed by crewmember, flight day, and mission. Based on the results of this analysis, it was recommended that for the Requirements Review and Preliminary Design Review iterations the maximum utilization per shift should be 75 percent for the Payload Specialist (PS) and 65 percent for the Mission Specialist (MS); and for the basic and final iterations, the maximum utilization shift should be 85 percent for the PS and 75 percent for the MS. Additional recommendations include limiting the amount of activity during the first two shifts whenever possible and establishing a common set of guidelines for the calculations of crew utilization

One-loop Neutron Electric Dipole Moment from Supersymmetry without R-parity

We present a detailed analysis together with exact numerical calculations on one-loop contributions to neutron electric dipole moment from supersymmetry without R-parity, focusing on the gluino, chargino, and neutralino contributions. Apart from the neglected family mixing among quarks, complete formulae are given for the various contributions, through the quark dipole operators, to which the present study is restricted. We discuss the structure and main features of the R-parity violating contributions and the interplay between the R-parity conserving and violating parameters. In particular, the parameter combination $\mu_i^*\lambda^{\prime}_{i11}$, under the optimal parametrization adopted, is shown to be solely responsible for the R-parity violating contributions in the supersymmetric loop diagrams. While $\mu_i^*\lambda^{\prime}_{i11}$ could bear a complex phase, the latter is not necessary to have a R-parity violating contribution.Comment: 43 pages Revtex with 15 eps- and 4 ps- figure files incoporated; proofread version to be published in Phys. Rev.

Resource envelope concepts for mission planning

Seven proposed methods for creating resource envelopes for Space Station Freedom mission planning are detailed. Four reference science activity models are used to illustrate the effect of adding operational flexibility to mission timelines. For each method, a brief explanation is given along with graphs to illustrate the application of the envelopes to the power and crew resources. The benefits and costs of each method are analyzed in terms of resource utilization. In addition to the effect on individual activities, resource envelopes are analyzed at the experiment level

Analysis and Derivation of Allocations for Fiber Contaminants in Liquid Bipropellant Systems

An analysis was performed to identify the engineering rationale for the existing particulate limits in MSFC-SPEC-164, Cleanliness of Components for Use in Oxygen, Fuel, and Pneumatic Systems, determine the applicability of this rationale to fibers, identify potential risks that may result from fiber contamination in liquid oxygen/fuel bipropellant systems, and bound each of these risks. The objective of this analysis was to determine whether fiber contamination exceeding the established quantitative limits for particulate can be tolerated in these systems and, if so, to derive and recommend quantitative allocations for fibers beyond the limits established for other particulate. Knowledge gaps were identified that limit a complete understanding of the risk of promoted ignition from an accumulation of fibers in a gaseous oxygen system

Inferring gene regulatory networks from gene expression data by a dynamic Bayesian network-based model

Enabled by recent advances in bioinformatics, the inference of gene regulatory networks (GRNs) from gene expression data has garnered much interest from researchers. This is due to the need of researchers to understand the dynamic behavior and uncover the vast information lay hidden within the networks. In this regard, dynamic Bayesian network (DBN) is extensively used to infer GRNs due to its ability to handle time-series microarray data and modeling feedback loops. However, the efficiency of DBN in inferring GRNs is often hampered by missing values in expression data, and excessive computation time due to the large search space whereby DBN treats all genes as potential regulators for a target gene. In this paper, we proposed a DBN-based model with missing values imputation to improve inference efficiency, and potential regulators detection which aims to lessen computation time by limiting potential regulators based on expression changes. The performance of the proposed model is assessed by using time-series expression data of yeast cell cycle. The experimental results showed reduced computation time and improved efficiency in detecting gene-gene relationships

Inferring gene regulatory networks from gene expression data by a dynamic Bayesian network-based model

Enabled by recent advances in bioinformatics, the inference of gene regulatory networks (GRNs) from gene expression data has garnered much interest from researchers. This is due to the need of researchers to understand the dynamic behavior and uncover the vast information lay hidden within the networks. In this regard, dynamic Bayesian network (DBN) is extensively used to infer GRNs due to its ability to handle time-series microarray data and modeling feedback loops. However, the efficiency of DBN in inferring GRNs is often hampered by missing values in expression data, and excessive computation time due to the large search space whereby DBN treats all genes as potential regulators for a target gene. In this paper, we proposed a DBN-based model with missing values imputation to improve inference efficiency, and potential regulators detection which aims to lessen computation time by limiting potential regulators based on expression changes. The performance of the proposed model is assessed by using time-series expression data of yeast cell cycle. The experimental results showed reduced computation time and improved efficiency in detecting gene-gene relationships

Karakterisasi Asam Lemak Hasil Hidrolisis pada Minyak Biji Kelor (Moringa Oleifera) dengan Metode Kromatografi Gas-Spektroskopi Massa

Penelitian ini bertujuan untuk mengetahui karakterisasi asam lemak hasil hidrolisis pada biji kelor (Moringa oleifera) dengan metode kromatografi gas-spektroskopi massa. Sampel yang digunakan dalam penelitian ini adalah biji kelor kering dan basah. Sampel biji kelor diekstraksi menggunakan n-heksan untuk memperoleh minyak. Ditentukan bilangan asam dan bilangan penyabunan. Menghidrolisis minyak hasil ekstraksi dengan larutan KOH dan katalis H2SO4 menjadi asam lemak bebas, analisis asam lemak kemudian dikonversi menjadi metil ester dengan menggunakan pelarut CH3OH dan H2SO4 sebagai katalis. Penelitian ini menggunakan Kromatografi Gas-Spektroskopi Massa untuk mengidentifikasi asam lemak dalam sampel. Dari analisa Kromatografi Gas-Spektroskopi Massa yang telah dilakukan, asam lemak minyak biji kelor kering yang dihasilkan adalah asam laurat, asam palmitoleat, asam palmitat, asam oleat, asam stearat, dan asam arakidat. Sedangkan untuk asam lemak minyak biji kelor basah yang dihasilkan adalah asam palmitoleat, asam palmitat, asam oleat, asam stearat, asam eikosenat, asam arakidat, asam behenat, dan asam lignoserat. Dimana komponen terbesar metil ester pada biji kelor kering dan biji kelor basah adalah metil oleat dengan persentasi masing-masing 38,08% dan 38,84%

A web-based course assessment tool with direct mapping to student outcomes

The assessment of curriculum outcomes is an essential element for continuous academic improvement. However, the collection, aggregation and analysis of assessment data are notoriously complex and time-consuming processes. At the same time, only few developments of supporting electronic processes and tools for continuous academic program assessment and curriculum performance feedback have emerged. In this paper, we introduce a novel course assessment process supported by a Web based interface that articulates and streamlines the assessment data collection, performance evaluation and tracking of remedial recommendations. To close the assessment loop, the Web interface provides also a mechanism to follow up on the implementation of remedial recommendations and analyzes their associated reflective actions during the subsequent course assessment cycle. A guide to map assessment instruments to the course and overall program outcomes is advocated by the proposed tool to propagate the course assessment results towards higher educational objectives (e.g., student outcomes) in a dashboard-like assessment interface. This approach streamlines improvements in education through reflecting the achievement of course outcomes on the achievement of higher educational objectives.In addition, the tool maps the course outcomes to the corresponding course outlines to facilitate the detection of areas where revisions in the instruction and content is needed, and to best respond to recommendations and remedial actions. We provide a methodical approach as well as a Web-based automation of the assessment process, which we evaluate in the context of our regular academic assessment cycles that have eventually led to a successful international accreditation experience. The collected assessment data shows a significant improvement in the achievement rate of the student outcomes after deploying the tool

CP-odd Phase Correlations and Electric Dipole Moments

We revisit the constraints imposed by electric dipole moments (EDMs) of nucleons and heavy atoms on new CP-violating sources within supersymmetric theories. We point out that certain two-loop renormalization group corrections induce significant mixing between the basis-invariant CP-odd phases. In the framework of the constrained minimal supersymmetric standard model (CMSSM), the CP-odd invariant related to the soft trilinear A-phase at the GUT scale, theta_A, induces non-trivial and distinct CP-odd phases for the three gaugino masses at the weak scale. The latter give one-loop contributions to EDMs enhanced by tan beta, and can provide the dominant contribution to the electron EDM induced by theta_A. We perform a detailed analysis of the EDM constraints within the CMSSM, exhibiting the reach, in terms of sparticle spectra, which may be obtained assuming generic phases, as well as the limits on the CP-odd phases for some specific parameter points where detailed phenomenological studies are available. We also illustrate how this reach will expand with results from the next generation of experiments which are currently in development.Comment: 31 pages, 21 eps figures; v2: additional remarks on 2-loop threshold corrections and references added; v3: typos corrected, to appear in Phys. Rev.

Critical Drivers and Consequences of Poor Facility Management in the Kumasi Metropolis of Ghana

Facilities require massive sums of financial resources to construct and maintain. Available statistics shows that facilities constitute about 80% of the financial resources of established organizations. It also provides an enclosed atmosphere within which organizations operate. However, despite the financial composition and the inextricable link between facilities and achievement of the goals of every organization, it is very unwelcomed that they are poorly managed in many institutions in Ghana. This paper sought to fill the knowledge gap by identifying and ranking the critical drivers and consequences of poor facility management in the Kumasi Metropolis. The study employed case study as a research design within quantitative research methodological paradigm and gathered primary data from 102 respondents comprising of hostel caretakers, facility managers and maintenance teams using questionnaires. It was established the all the 11 drivers and 9 consequences of poor facility management in the study were considered critical because they scored mean values above the conventional mean of 3.5. The study contributed to existing literature by ranking the drivers and consequences of poor facility management. It was consequently recommended among others that rent escalator clauses should be used to regulate indisciplinary conduct of facility users and that facility management should be made one of the top priorities of institutional management. Keywords: Consequences, drivers, facilities, organizations, poor facility managemen