2,360 research outputs found
The problem of managing a strategic reserve
AbstractWe develop a method of managing strategic reserves, in this case, the U.S. Strategic Cobalt Reserve. A rationale for the stockpiling of cobalt is presented, followed by a method for bringing the stockpiled amount from any level to a desired goal, in this case an amount determined by the Federal Emergency Management Agency to last through three years of conventional warfare. The method involves solving a stochastic programming problem in order to balance the expected values of the social benefit and the social cost of building the stockpile—Social benefit is accrued by decreasing the impact and the probability of a war or a major supply disruption occuring before the stockpile goal is realized; social cost is determined from the additional amount U.S. cobalt consumers must pay due to the increase in world demand brought about by stockpiling. The management of the filled stockpile is then discussed, introducing the idea of using the stockpile to assure stability in the world price of cobalt and of defraying maintenance costs by market speculation. Least-squares fitting is used to determine whether prices are high or low and how much to sell or buy, respectively, to bring prices back into line. Then the conditions under which the stockpile should be drawn down are considered, with the proper rate and total amount of released stockpile material determined for two cases, that of a major supply disruption and that of actual warfare. Finally, generalization of the method to cover other strategic stockpiles is discussed
Mount Carmel Area Community Center Strategic Plan
This document outlines various strategic planning areas for the Mount Carmel Area Community Center located in Mount Carmel, Pennsylvania, to consider, including: building repairs, partners, funding, operations, and marketing. The project builds on prior Bucknell University student reports conducted in partnership with the Mount Carmel Area Community Center (MCACC).
This project was completed as a course requirement for MORS 400: Management Consulting at Bucknell University in Spring 2023, taught by Prof. Eric Martin. The project was in partnership with the Mount Carmel Area Community Center
A critical review of the epidemiology of Agent Orange/TCDD and prostate cancer
To inform risk assessment and regulatory decision-making, the relationship between 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and prostate cancer requires clarification. This article systematically and critically reviews the epidemiologic evidence on the association between exposure to TCDD or Agent Orange, a TCDD-contaminated herbicide used during the Vietnam War, and prostate cancer risk. Articles evaluated include 11 studies of three cohorts, four case–control or cross-sectional studies, and three case-only studies of military veterans with information on estimated Agent Orange or TCDD exposure; 13 studies of seven cohorts, one case–control study, and eight proportionate morbidity or mortality studies of Vietnam veterans without information on Agent Orange exposure; 11 cohort studies of workers with occupational exposure to TCDD; and two studies of one community cohort with environmental exposure to TCDD. The most informative studies, including those of Vietnam veterans involved in Agent Orange spraying or other handling, herbicide manufacturing or spraying workers with occupational TCDD exposure, and community members exposed to TCDD through an industrial accident, consistently reported no significant increase in prostate cancer incidence or mortality. Only some potentially confounded studies of Vietnam veterans compared with the general population, studies with unreliable estimates of Agent Orange exposure, and analyses of selected subgroups of Vietnam veterans reported positive associations. Overall, epidemiologic research offers no consistent or convincing evidence of a causal relationship between exposure to Agent Orange or TCDD and prostate cancer. More accurate exposure assessment is needed in large epidemiologic studies to rule out a causal association more conclusively. Electronic supplementary material The online version of this article (doi:10.1007/s10654-014-9931-2) contains supplementary material, which is available to authorized users
Blockchain Application Within a Multi-Sensor Satellite Architecture
With the thrust towards multi-sensor satellite architectures for earth and space exploration, such as constellations and swarms, new technologies are required to enable the transition to this future capability. One of the areas of interest is establishing secure, efficient and prioritized data and command communication pathways among ground and space-based sources for such systems. This paper presents early research results on the potential role, capabilities and value of blockchain usage within constellation and swarm satellite architectures. It demonstrates the use of blockchain's smart contract and distributed ledger capabilities for secure and prioritized multi-sensor satellite collaborative data exchanges, as well as the logging and tracking of command and control events. Adapting and utilizing this emerging technology will aid in addressing technology gaps expected from future constellation flight architectures, such as managing collective computational operations (correlation), dynamic and autonomous observation planning, time-critical events, and provenance tied to ground and space-based autonomous operations and control recordkeeping. In this scenario blockchain is applied in encrypted command transmittal to multiple, yet specific, entities enabling acknowledgement transmittals, performance scalability, and automatic event-based triggering
Pressure compensated variable displacement internal gear pumps
Describes a pump that has a fixed gear axis eccentricity and varies displacement by moving controlling elements linearly along the drive shaft. A pressure compensator may be employed to displace the controlling elements. It includes a housing penetrated by a drive shaft rotating internal elements. The internal components slide along the longitudinal axis established by the drive shaft to vary the fluid displacement. The axially-moving elements include the drive shaft, inner gerotor element, port plug, thrust bearing and retainer sleeve. The drive shaft includes an internal flanged forming a piston. The outward face of the piston is in contact with fluid at system pressure. The internal gerotor element and port plug are retained against the piston by a thrust bearing that slides over the drive shaft and is held in place by a retainer sleeve. The port plug has a rear face that also functions as a piston and this face is the same size as the flanged piston. Thus, the outward piston face and rear face of the port plug can push the assembly in the housing along the longitudinal axis established by the driveshaft. A pressure compensator senses the system pressure and then displaces the axially-moving elements to produce the required displacement. The compensator is controlled by pressure operating against a return spring. The pressure compensator may either be external or integral with the pump
Superconductivity up to 29 K in SrFe2As2 and BaFe2As2 at high pressures
We report the discovery of superconductivity at high pressure in SrFe2As2 and
BaFe2As2. The superconducting transition temperatures are up to 27 K in
SrFe2As2 and 29 K in BaFe2As2, making these the highest pressure-induced
superconducting materials discovered thus far.Comment: Accepted in Journal of Physics: Condensed Matte
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Zebrafish behavioural profiling identifies GABA and serotonin receptor ligands related to sedation and paradoxical excitation.
Anesthetics are generally associated with sedation, but some anesthetics can also increase brain and motor activity-a phenomenon known as paradoxical excitation. Previous studies have identified GABAA receptors as the primary targets of most anesthetic drugs, but how these compounds produce paradoxical excitation is poorly understood. To identify and understand such compounds, we applied a behavior-based drug profiling approach. Here, we show that a subset of central nervous system depressants cause paradoxical excitation in zebrafish. Using this behavior as a readout, we screened thousands of compounds and identified dozens of hits that caused paradoxical excitation. Many hit compounds modulated human GABAA receptors, while others appeared to modulate different neuronal targets, including the human serotonin-6 receptor. Ligands at these receptors generally decreased neuronal activity, but paradoxically increased activity in the caudal hindbrain. Together, these studies identify ligands, targets, and neurons affecting sedation and paradoxical excitation in vivo in zebrafish
GECKO: a complete large-scale gene expression analysis platform
BACKGROUND: Gecko (Gene Expression: Computation and Knowledge Organization) is a complete, high-capacity centralized gene expression analysis system, developed in response to the needs of a distributed user community. RESULTS: Based on a client-server architecture, with a centralized repository of typically many tens of thousands of Affymetrix scans, Gecko includes automatic processing pipelines for uploading data from remote sites, a data base, a computational engine implementing ~ 50 different analysis tools, and a client application. Among available analysis tools are clustering methods, principal component analysis, supervised classification including feature selection and cross-validation, multi-factorial ANOVA, statistical contrast calculations, and various post-processing tools for extracting data at given error rates or significance levels. On account of its open architecture, Gecko also allows for the integration of new algorithms. The Gecko framework is very general: non-Affymetrix and non-gene expression data can be analyzed as well. A unique feature of the Gecko architecture is the concept of the Analysis Tree (actually, a directed acyclic graph), in which all successive results in ongoing analyses are saved. This approach has proven invaluable in allowing a large (~ 100 users) and distributed community to share results, and to repeatedly return over a span of years to older and potentially very complex analyses of gene expression data. CONCLUSIONS: The Gecko system is being made publicly available as free software . In totality or in parts, the Gecko framework should prove useful to users and system developers with a broad range of analysis needs
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