An automated tool for the design and assessment of space systems

Space systems can be characterized as both large and complex but they often rely on reusable subcomponents. One problem in the design of such systems is the representation and validation of the system, particularly at the higher levels of management. An automated tool is described for the representation, refinement, and validation of such complex systems based on a formal design theory, the Theory of Plausible Design. In particular, the steps necessary to automate the tool and make it a competent, usable assistant, are described

Do Modern Japanese Inventory Methods Apply To Hong Kong?

The ability to achieve higher standards of productivity without sacrificing quality is an important goal of a manufacturing firm. A primary reason offered to explain Japanese firms’ successes has been the dominant role of the use of the Just-In-Time (JIT) operational philosophy (Mehra & Inman, 1992). If successfully implemented, JIT reduces inventory and ultimately results in reduction in manufacturing costs along with improvement in profitability (James, 1994).  There are three main manufacturing objectives for JIT (Suzaki, 1987).  One is increasing the organization's ability to compete with rival firms and remain competitive over the long run. JIT allows companies to develop optimal processes for manufacturing their products.  A second is increasing the degree of efficiency within the production process.  JIT allows greater level of productivity and minimizes the associated costs of production.  The third is reducing the level of wasted materials, time, and effort involved in the production process.  Elimination of unnecessary waste can significantly reduce costs of production.  Much of the literature concerned with the implementation of JIT deals specifically with elements that are crucial to successful implementation (Karen & Anthony, 1993).  This study looked at three of those elements; namely, management commitment, JIT production strategy, and JIT vendor strategy. If these "critical" elements are not present, the potential level of JIT implementation may be low.  The Hong Kong electronics/electrical manufacturing industry was chosen as the context for this study. A survey questionnaire based on the three main prerequisites of JIT implementation was developed and sent out in order to investigate whether JIT implementation could be carried out in Hong Kong. Both inferential analysis and descriptive analysis were used to interpret the results.  The study found (1) No significant relationship existed between management commitment and the potential level of JIT implementation, and (2) A significant relationship did exist between JIT production strategy and JIT vendor strategy and the potential level of JIT implementation

Alien Registration- Landry, Joseph P. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/28691/thumbnail.jp

Alien Registration- Landry, Joseph P. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/28691/thumbnail.jp

Alien Registration- Landry, Joseph P. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/28691/thumbnail.jp

Cholesterol-directed nanoparticle assemblies based on single amino acid peptide mutations activate cellular uptake and decrease tumor volume.

Peptide drugs have been difficult to translate into effective therapies due to their low in vivo stability. Here, we report a strategy to develop peptide-based therapeutic nanoparticles by screening a peptide library differing by single-site amino acid mutations of lysine-modified cholesterol. Certain cholesterol-modified peptides are found to promote and stabilize peptide α-helix formation, resulting in selectively cell-permeable peptides. One cholesterol-modified peptide self-assembles into stable nanoparticles with considerable α-helix propensity stabilized by intermolecular van der Waals interactions between inter-peptide cholesterol molecules, and shows 68.3% stability after incubation with serum for 16 h. The nanoparticles in turn interact with cell membrane cholesterols that are disproportionately present in cancer cell membranes, inducing lipid raft-mediated endocytosis and cancer cell death. Our results introduce a strategy to identify peptide nanoparticles that can effectively reduce tumor volumes when administered to in in vivo mice models. Our results also provide a simple platform for developing peptide-based anticancer drugs

Redox control of human mitochondrial outer membrane protein mitoneet [2FE-2S] clusters by biological thiols and hydrogen peroxide

Background: MitoNEET is a target of the type II diabetes drug pioglitazone and contains a [2Fe-2S] cluster. Results: The mitoNEET [2Fe-2S] cluster can be reduced by biological thiols and reversibly oxidized by hydrogen peroxide. Conclusion: The redox state of mitoNEET [2Fe-2S] clusters can be regulated by thiols and oxidative signals. Significance: MitoNEET may act as a redox sensor to modulate mitochondrial functions. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

The N-Terminal Domain of Human DNA Helicase Rtel1 Contains a Redox Active Iron-Sulfur Cluster

© 2014 Aaron P. Landry and Huangen Ding. Human telomere length regulator Rtel1 is a superfamily II DNA helicase and is essential for maintaining proper length of telomeres in chromosomes. Here we report that the N-terminal domain of human Rtel1 (RtelN) expressed in Escherichia coli cells produces a protein that contains a redox active iron-sulfur cluster with the redox midpoint potential of -248 ± 10 mV (pH 8.0). The iron-sulfur cluster in RtelN is sensitive to hydrogen peroxide and nitric oxide, indicating that reactive oxygen/nitrogen species may modulate the DNA helicase activity of Rtel1 via modification of its iron-sulfur cluster. Purified RtelN retains a weak binding affinity for the single-stranded (ss) and double-stranded (ds) DNA in vitro. However, modification of the iron-sulfur cluster by hydrogen peroxide or nitric oxide does not significantly affect the DNA binding activity of RtelN, suggesting that the iron-sulfur cluster is not directly involved in the DNA interaction in the N-terminal domain of Rtel1

A Cost Analysis Case Study Of A Small Chinese Manufacturer

This study investigated whether a small firm, China Umbrella Factory Limited (CUFL), and in fact any firm in a developing country (mainland China), could benefit from a formal, activity-based costing system. Many small firms, even more so than larger firms, find themselves particularly vulnerable to competitive challenges because the smaller firms lack the know-how and resources to know their true costs and profit margins. Smaller firms tend to use heuristics, or rules-of-thumb, in their estimation of costs as opposed to the bonafide use of more sophisticated and validated costing systems, whether traditional or activity-based costing (ABC). Comparisons of this firm’s current estimations of costs were made using both of these costing systems. Results indicated differences across the three methods. It was discovered that cost distortions that disfavored the estimation and traditional methods favored the ABC method. Notwithstanding the benefits found with using ABC, the firm decided not to adopt this method. A major constraining factor rested with the limitation of human resources – particularly with training in ABC as well as general management accounting. Furthermore since ABC, in a greater fundamental sense, benefits firms with significant overhead (when measured as a proportion of total cost), ABC would only provide limited benefits relative to the cost of implementation given the low-tech, primarily labor-based nature of this firm and its products

Granular packings with moving side walls

The effects of movement of the side walls of a confined granular packing are studied by discrete element, molecular dynamics simulations. The dynamical evolution of the stress is studied as a function of wall movement both in the direction of gravity as well as opposite to it. For all wall velocities explored, the stress in the final state of the system after wall movement is fundamentally different from the original state obtained by pouring particles into the container and letting them settle under the influence of gravity. The original packing possesses a hydrostatic-like region at the top of the container which crosses over to a depth-independent stress. As the walls are moved in the direction opposite to gravity, the saturation stress first reaches a minimum value independent of the wall velocity, then increases to a steady-state value dependent on the wall-velocity. After wall movement ceases and the packing reaches equilibrium, the stress profile fits the classic Janssen form for high wall velocities, while it has some deviations for low wall velocities. The wall movement greatly increases the number of particle-wall and particle-particle forces at the Coulomb criterion. Varying the wall velocity has only small effects on the particle structure of the final packing so long as the walls travel a similar distance.Comment: 11 pages, 10 figures, some figures in colo