4,424 research outputs found
Checklist of good contamination control practices from a manufacturing viewpoint
Contamination control checklists for manufacturing or assembly plant
Operations research investigations of satellite power stations
A systems model reflecting the design concepts of Satellite Power Stations (SPS) was developed. The model is of sufficient scope to include the interrelationships of the following major design parameters: the transportation to and between orbits; assembly of the SPS; and maintenance of the SPS. The systems model is composed of a set of equations that are nonlinear with respect to the system parameters and decision variables. The model determines a figure of merit from which alternative concepts concerning transportation, assembly, and maintenance of satellite power stations are studied. A hybrid optimization model was developed to optimize the system's decision variables. The optimization model consists of a random search procedure and the optimal-steepest descent method. A FORTRAN computer program was developed to enable the user to optimize nonlinear functions using the model. Specifically, the computer program was used to optimize Satellite Power Station system components
Investigation of Force Decay in Aesthetic, Fibre-Reinforced Composite Orthodontic Archwires
Background/Objectives: Because polymer-based materials typically exhibit viscoelastic properties, the objective was to determine if commercially available, aesthetic, fibre-reinforced composite archwires maintain continuous forces without undergoing force decay when deflected continuously.
Materials/Methods: Quasi force decay was evaluated by comparing three-point bending profiles of nickelātitanium (NiTi) and fibre-reinforced composite archwires (BioMers) prior to and after 30 days of continuous deflection of either 1 or 2mm. Paired t-tests or non-parametric signed rank tests were used to statistically compare pre- and post-deflection bending forces. A control group consisting of wires not subject to the 30-day constant deflection was tested to check whether the initial testing altered the second three-point bend test.
Results: Significant (P \u3c 0.01) differences in the pre- and post-deflection deactivation force delivery were most evident in the composite 2mm deflection group and all of the NiTi groups. The composite 2mm deflection group failed to deliver consistent forces as the majority of the wires experienced crazing during the 30-day deflection period. The decrease in force delivery in the NiTi groups may be attributed to the small standard deviations.
Conclusions: The composite 1mm deflection group demonstrated that fibre-reinforced composite archwires are able to deliver a consistent force after 30 days of deflection. However, the clinical applicability of these fibre-reinforced composite archwires may be limited as they are unable to sustain deflections of 2mm without experiencing crazing and loss of force delivery.
Limitations: Clinical efficacy of the aesthetic, fibre-reinforced composite orthodontic archwires remains to be observed
The Effect of Water Storage on the Bending Properties of Esthetic, Fiber-Reinforced Composite Orthodontic Archwires
Objective: To study the effect of water storage on the bending properties of fiber-reinforced composite archwires and compare it to nickel-titanium (NiTi), stainless steel (SS), and beta-titanium archwires.
Materials and Methods: Align A, B, and C and TorQ A and B composite wires from BioMers Products, 0.014-, 0.016, and 0.018-inch, and 0.019 Ć 0.025-inch NiTi, 0.016-inch SS, and 0.019 Ć 0.025-inch beta-titanium archwires were tested (n ā=ā 10/type/size/condition). A 20-mm segment was cut from each end of the archwire; one end was then stored in water at 37Ā°C for 30 days, while the other was stored dry. The segments were tested using three-point bending to a maximum deflection of 3.1 mm with force monitored during loading (activation) and unloading (deactivation). Statistical analysis was completed via two-way analysis of variance with wire and condition (dry and water-stored) as factors.
Results: In terms of stiffness and force delivery during activation, in general: beta-titanium was \u3e TorQ B \u3e TorQ A \u3e 0.019 Ć 0.025-inch NiTi and 0.016-inch SS \u3e Align C \u3e 0.018-inch NiTi \u3e Align B \u3e 0.016-inch NiTi \u3e Align A \u3e 0.014-inch NiTi. Water exposure was detrimental to the larger translucent wires (Align B and C, TorQ A and B) because they were more likely to craze during bending, resulting in decreased forces applied at a given deflection. Align A and the alloy wires were not significantly (P\u3e .05) affected by water storage. Overall, the alloy wires possessed more consistent force values compared to the composite wires
Criteria for treatment selection of adult male public offenders
Thesis (M.S.)--Boston Universit
Introducing new diagnostics into STI control programmes: the importance of programme science.
Many innovative diagnostic technologies will become commercially available over the next 5-10 years. These tests can potentially transform the diagnosis of sexually transmitted infections but their introduction into control programmes can be hampered by health system constraints, and political, cultural, socioeconomic and behavioural factors. We used the introduction of syphilis rapid tests to illustrate the importance of programme science to address the gap between accruing evidence of acceptable test performance and the complexity of programme design, implementation and evaluation of test deployment to address public health needs and improve patient-important outcomes
Corporate Policy Management for a Financial Organization
A large financial organization has intent of deploying a framework to support Corporate and Business Policies and Procedures. Internally, the policies and procedures lack the standardization and consistency necessary to publish policies across a large diverse organization. Additionally, the organization needs to ensure quality in the protocols and templates, products and practices as well as provide a framework to automate the support of policy and procedure administrative aspects related to content management, document retention and destruction and increased search efficiencies. Additional challenges exist external to the organization in the form of Office of the Comptroller of the Currency (OCC) requirements to comply with the Sarbanes-Oxley Act
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