Method for forming hermetic seals

The firmly adherent film of bondable metal, such as silver, is applied to the surface of glass or other substrate by decomposing a layer of solution of a thermally decomposable metallo-organic deposition (MOD) compound such as silver neodecanoate in xylene. The MOD compound thermally decomposes into metal and gaseous by-products. Sealing is accomplished by depositing a layer of bonding metal, such as solder or a brazing alloy, on the metal film and then forming an assembly with another high melting point metal surface such as a layer of Kovar. When the assembly is heated above the temperature of the solder, the solder flows, wets the adjacent surfaces and forms a hermetic seal between the metal film and metal surface when the assembly cools

Methods of Science Vocabulary Instruction with a Focus on the Inclusive Classroom

Language and its use is the key to communicating to others the world around us. Science, like many other subjects has a language all its own. Language in the science classroom is fi lied with words that the students may never hear outside of that classroom. This study employed lesson study to find and implement a vocabulary strategy that would work for the students. The literature was reviewed for common strategies that are in use today and what possible modifications cou ld be used to enhance student learning. Throughout the study, student achievement and confidence rose as a result of the implementation of the strategies

The Applicability of the Distribution Coefficient, KD, Based on Non-Aggregated Particulate Samples from Lakes with Low Suspended Solids Concentrations

Separate phases of metal partitioning behaviour in freshwater lakes that receive varying degrees of atmospheric contamination and have low concentrations of suspended solids were investigated to determine the applicability of the distribution coefficient, KD. Concentrations of Pb, Ni, Co, Cu, Cd, Cr, Hg and Mn were determined using a combination of filtration methods, bulk sample collection and digestion and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Phytoplankton biomass, suspended solids concentrations and the organic content of the sediment were also analysed. By distinguishing between the phytoplankton and (inorganic) lake sediment, transient variations in KD were observed. Suspended solids concentrations over the 6-month sampling campaign showed no correlation with the KD (n = 15 for each metal, p > 0.05) for Mn (r2 = 0.0063), Cu (r2 = 0.0002, Cr (r2 = 0.021), Ni (r2 = 0.0023), Cd (r2 = 0.00001), Co (r2 = 0.096), Hg (r2 = 0.116) or Pb (r2 = 0.164). The results implied that colloidal matter had less opportunity to increase the dissolved (filter passing) fraction, which inhibited the spurious lowering of KD. The findings conform to the increasingly documented theory that the use of KD in modelling may mask true information on metal partitioning behaviour. The root mean square error of prediction between the directly measured total metal concentrations and those modelled based on the separate phase fractions were ± 3.40, 0.06, 0.02, 0.03, 0.44, 484.31, 80.97 and 0.1 μg/L for Pb, Cd, Mn, Cu, Hg, Ni, Cr and Co respectively. The magnitude of error suggests that the separate phase models for Mn and Cu can be used in distribution or partitioning models for these metals in lake water

Using operational risk to increase systems engineering effectiveness

Includes bibliographical references.2016 Summer.A key activity in the systems engineering process is managing risk. Systems engineers transform end-user needs into requirements that then drive design, development, and deployment activities. Experienced systems engineers are aware of both programmatic risk and technical risk and how these risks impact program outcomes. A programmatic change to cost, schedule, process, team structure, or a wide variety of other elements may impact the engineering effort and increase the risk of failing to deliver a product or capability when needed, with all required functionality, at the promised cost. Technical challenges may introduce risk as well. If a subcomponent or element of the design is immature or doesn’t perform as expected, additional effort may be required to redesign the element or may even necessitate a change in requirements or a complete system re-design. Anticipating programmatic and technical risks and implementing plans to mitigate these risks is part of the systems engineering process. Even with a potent risk management process in place, end-users reject new capabilities when the iii delivered capabilities fail to perform to their expectations or fail to address the end-user’s operational need. The time between the identification of an operational need and the delivery of the resulting capability may be months or even years. When delivered, the new capability either does not fulfil the original need or the need has evolved over time. This disconnect increases operational risk to the end-user’s mission or business objectives. When systems engineers explicitly identify and mitigate operational risk, in addition to programmatic and technical risk, program outcomes are more likely to meet the end-user’s real operational need. The purpose of this research is first to define the activities that could be used by systems engineers to ensure that engineering activities are influenced by operational risk considerations. Secondly, to determine if a focus on operational risk during the systems engineering lifecycle has a positive impact on program outcomes. A structured approach to addressing operational risk during the systems engineering process, Operational Risk-Driven Engineering Requirements/Engineering Development (ORDERED), is introduced. ORDERED includes an exhaustive operational risk taxonomy designed to assist systems engineers with incorporating the end-user’s evolving operational risk considerations into systems engineering activities. iv To examine the relationship between operational risk considerations during the systems engineering process and program outcomes, a survey instrument was developed and administered. In addition, a system dynamics model was developed to examine the relationship between operational risk and technical debt. Finally, case studies of successful and challenged programs were evaluated against characteristics of successfully addressing operational risk during the program lifecycle. These activities lead to the conclusion that a focus on operational risk during the systems engineering lifecycle has a positive impact on program outcomes