The Regional Sensitivity of Chondrocyte Gene Expression to Coactive Mechanical Load and Exogenous TNF-a Stimuli

Both mechanical load and elevated levels of proinflammatory cytokines have been associated with the risk for developing osteoarthritis (OA), yet the potential interaction of these mechanical and biological factors is not well understood. The purpose of this study was to evaluate the response of chondrocytes to the effects of dynamic unconfined compression, TNF-a, and the simultaneous effects of dynamic unconfined compression and TNF-a. The response to these three treatments was markedly different and, taken together, the response in the gene expression of chondrocytes to the different treatment conditions suggest a complex interaction between structure, biology, and mechanical loading

The thermal contact conductance of hard and soft coat anodized aluminium

An experimental investigation of the thermal contact conductance of anodized coatings Introduction The thermal performance of microelectronic components has become increasingly important as systems are miniaturized. The dense packaging on standard electronic modules (SEM), widely used in military applications, often leads to thermally induced failures because of the thermal resistance occurring between the module guide fibs and the chassis card rails. This thermal resistance results from the limited contact area at the interface, the uneven contact pressure, surface characteristics, and the bulk resistance of the coatings on the card rails and guide ribs. As circuit densities have increased, cooling schemes have been developed to maintain device temperatures within their optimum design specification. However, other techniques that help reduce the temperature change across component interfaces must also be investigated. Many electronic systems incorporate anodized surfaces, which contribute to the thermal resistance at component interfaces. This paper reports the results of an experimental investigation of anodized films grown at different temperatures and in different electrolyte solutions, and compares these results with previously published information

Probabilistic optimization of multitool machining operations

[4] . These models can be used to develop optimal tool change intervals for a given tool replacement policy. In the past, attempts were made to develop optimal policies and optimal tool change intervals, primarily using Monte Carlo Simulation technique

Comparison of profiles and fluxes of heat and momentum above and below an air–water interface

The velocity and temperature fields on both sides of an air-water interface were examined experimentally in order to understand better the physical processes of momentum and heat transfer through the surface layers about the interface. An examination of temperature and velocity profiles plotted in "law-of-the-wall" coordinates leads to the conclusion that, both in the air and in the water, the mechanism of momentum transfer is affected by surface roughness changes, but the mechanism of heat transfer is not. In the water surface layer the velocity fluctuations due to the wave-related motions are of the same order as the purely turbulent motions. The turbulent components closely resemble those found in boundary layers over solid walls. The measured total energy flux from the interface agrees well with the measured single-phase, vertical heat transport through the water surface layer. Introduction The velocity and temperature fields on both sides of an airwater interface have been examined experimentally in order to understand better the physical processes related to momentum and heat transfer through a water surface layer and a mobile boundary. These data will be ultimately used to calibrate a numerical model which couples the air and water boundary layers across the interface

Non-Ideal Isentropic Gas Flow Through Converging-Diverging Nozzles

(14) were all set to zero. This reduced the gas to an ideal gas with constant specific heats. The program was then run at the same p u T x and P2/p\ values as those given in In conclusion, a program has been developed to determine the expansion factor of a nonideal gas through a venturi meter. The program accounts for nonideal gas behavior as described by the Redlich-Kwong equation of state. For gas flows that are nonideal, the use of the ideal expansion factor in determining m, underestimates the true value. For the example given in this paper, a relative error as much as 6.58 percent was obtained when p 2 /p\ = 0.6 and d 2 /di = 0.8. The program also provides the means for determining the critical pressure ratio as well as the maximum flow rate per unit throat area. For the example given in this paper the maximum percent difference in the critical pressure ratio between the nonideal and ideal gases was 5.81 percent while the maximum percent difference in the maximum flow rate per unit throat area was 7.62 percent. An important aspect of the venturi flow problem that has not been treated in this paper is the nonideal gas effects on the discharge coefficient, C D . If these effects are minimal, then the procedure outlined in this paper would provide an accurate method for determining the mass flow rate of a nonideal gas through a venturi meter

Review and Evaluation of the J100â 10 Risk and Resilience Management Standard for Water and Wastewater Systems

Risk analysis standards are often employed to protect critical infrastructures, which are vital to a nation’s security, economy, and safety of its citizens. We present an analysis framework for evaluating such standards and apply it to the J100â 10 risk analysis standard for water and wastewater systems. In doing so, we identify gaps between practices recommended in the standard and the state of the art. While individual processes found within infrastructure risk analysis standards have been evaluated in the past, we present a foundational review and focus specifically on water systems. By highlighting both the conceptual shortcomings and practical limitations, we aim to prioritize the shortcomings needed to be addressed. Key findings from this study include (1) risk definitions fail to address notions of uncertainty, (2) the sole use of â worst reasonable caseâ assumptions can lead to mischaracterizations of risk, (3) analysis of risk and resilience at the threatâ asset resolution ignores dependencies within the system, and (4) stakeholder values need to be assessed when balancing the tradeoffs between risk reduction and resilience enhancement.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154262/1/risa13421_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154262/2/risa13421.pd

Cable Kinking Analysis and Pretention

Kinking of electromechanical cables in underwater application