3D Energy Harvester Evaluation

This paper discusses the characterization and evaluation of an MEMS based electrostatic generator, a part of the power supply unit of the self-powered microsystem[1,2,3]. The designed generator is based on electrostatic converter and uses the principle of conversion of non-electric energy into electrical energy by periodical modification of gap between electrodes of a capacitor [4]. The structure is designed and modeled as three-dimensional silicon based MEMS. Innovative approach involving the achievement of very low resonant frequency of the structure (about 100Hz) by usage of modified long cantilever spring design, minimum area of the chip, 3D work mode, the ability to be tuned to reach desired parameters, proves promising directions of possible further development

Design and Fabrication of 3D Electrostatic Energy Harvester

This paper discusses the design of an electrostatic generator, power supply component of the self-powered microsystem, which is able to provide enough energy to power smart sensor chains or if necessary also other electronic monitoring devices. One of the requirements for this analyzer is the mobility, so designing the power supply expects use of an alternative way of getting electricity to power the device, rather than rely on periodic supply of external energy in the form of charging batteries, etc. In this case the most suitable method to use is so-called energy harvesting – a way how to gather energy. This uses the principle of non-electric conversion of energy into electrical energy in the form of converters. The present study describes the topology design of such structures of electrostatic generator. Structure is designed and modeled as a three-dimensional silicon based MEMS. Innovative approach involving the achievement of very low resonant frequency of the structure, while the minimum area of the chip, the ability to work in all 3 axes of coordinate system and ability to be tuned to reach desired parameters proves promising directions of possible further development of this issue. The work includes simulation of electro-mechanical and electrical properties of the structure, description of its behavior in different operating modes and phases of activity. Simulation results were compared with measured values of the produced prototype chip. These results can suggest possible modifications to the proposed structure for further optimization and application environment adaptation

High Power Solid State Retrofit Lamp Thermal Characterization and Modeling

Thermal and thermo-mechanical modeling and characterization of solid state lightening (SSL) retrofit LED lamp are presented in this paper. Paramount importance is to design SSL lamps for reliability, in which thermal and thermo-mechanical aspects are key points. The main goal is to get a precise 3D thermal lamp model for further thermal optimization. Simulations are performed with ANSYS and CoventorWare software tools to compere different simulation approaches. Simulated thermal distribution has been validated with thermal measurement on a commercial 8W LED lamp. Materials parametric study has been carried out to discover problematic parts for heat transfer from power LEDs to ambient and future solutions are proposed. The objectives are to predict the thermal management by simulation of LED lamp, get more understanding in the effect of lamp shape and used materials in order to design more effective LED lamps and predict light quality, life time and reliability

In vitro three dimensional biomechanical comparison of two internal fixation methods in equine adult radii

"August 2007"The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Includes bibliographical references.Thesis (M.S.) University of Missouri-Columbia 2007.Dissertations, Academic -- University of Missouri--Columbia -- Veterinary medicine and surgery.Radius fracture configurations conducive to internal fixation most often contain a spiral or oblique fracture of the distal diaphysis. The location and fracture configurations are biomechanically challenging because of the limited amount of bone available distally for screw purchase and the complex three dimensional (3D) loading and unconstrained motions that occur in the distal radius. Development of an in vitro loading-measurement system that mimics in vivo unconstrained 3D relative motion of long bones, applies uniform load components over the entire length of a test specimen, and measures 3D relative motion to directly determine construct stiffness was verified. Stiffness results were comparable in magnitude to those theoretically predicted, and were consistently higher than results in the literature due to elimination of potting-fixture-test machine finite stiffness. Construct failure configurations were always reproducible with theoretical failure modes for bone. Biomechanical properties of the dynamic condylar screw (DCS) implant system and the double broad dynamic compression plate (bDCP) construct used to repair distal oblique diaphyseal osteotomies and ostectomies in adult cadaveric radii were compared. No statistical difference was observed between the DCS implant system and the bDCP construct stiffness during axial compression, torsion, or four-point bending; intact radii displayed the greatest stiffness. Torsion and four-point bending failure loads were not statistically different for the DCS implant system when compared to the bDCP construct

RyR1-targeted drug discovery pipeline integrating FRET-based high-throughput screening and human myofiber dynamic Ca2+ assays.

Elevated cytoplasmic [Ca2+] is characteristic in severe skeletal and cardiac myopathies, diabetes, and neurodegeneration, and partly results from increased Ca2+ leak from sarcoplasmic reticulum stores via dysregulated ryanodine receptor (RyR) channels. Consequently, RyR is recognized as a high-value target for drug discovery to treat such pathologies. Using a FRET-based high-throughput screening assay that we previously reported, we identified small-molecule compounds that modulate the skeletal muscle channel isoform (RyR1) interaction with calmodulin and FK506 binding protein 12.6. Two such compounds, chloroxine and myricetin, increase FRET and inhibit [3H]ryanodine binding to RyR1 at nanomolar Ca2+. Both compounds also decrease RyR1 Ca2+ leak in human skinned skeletal muscle fibers. Furthermore, we identified compound concentrations that reduced leak by > 50% but only slightly affected Ca2+ release in excitation-contraction coupling, which is essential for normal muscle contraction. This report demonstrates a pipeline that effectively filters small-molecule RyR1 modulators towards clinical relevance

Culture of equine fibroblast-like synoviocytes on synthetic tissue scaffolds towards meniscal tissue engineering: a preliminary cell-seeding study

Introduction. Tissue engineering is a new methodology for addressing meniscal injury or loss. Synovium may be an ideal source of cells for in vitro meniscal fibrocartilage formation, however, favorable in vitro culture conditions for synovium must be established in order to achieve this goal. The objective of this study was to determine cellularity, cell distribution, and extracellular matrix (ECM) formation of equine fibroblast-like synoviocytes (FLS) cultured on synthetic scaffolds, for potential application in synovium-based meniscal tissue engineering. Scaffolds included open-cell poly-L-lactic acid (OPLA) sponges and polyglycolic acid (PGA) scaffolds cultured in static and dynamic culture conditions, and PGA scaffolds coated in poly-L-lactic (PLLA) in dynamic culture conditions.Materials and Methods. Equine FLS were seeded on OPLA and PGA scaffolds, and cultured in a static environment or in a rotating bioreactor for 12 days. Equine FLS were also seeded on PGA scaffolds coated in 2% or 4% PLLA and cultured in a rotating bioreactor for 14 and 21 days. Three scaffolds from each group were fixed, sectioned and stained with Masson’s Trichrome, Safranin-O, and Hematoxylin and Eosin, and cell numbers and distribution were analyzed using computer image analysis. Three PGA and OPLA scaffolds from each culture condition were also analyzed for extracellular matrix (ECM) production via dimethylmethylene blue (sulfated glycosaminoglycan) assay and hydroxyproline (collagen) assay. PLLA coated PGA scaffolds were analyzed using double stranded DNA quantification as areflection of cellularity and confocal laser microscopy in a fluorescent cell viability assay.Results. The highest cellularity occurred in PGA constructs cultured in a rotating bioreactor, which also had a mean sulfated glycosaminoglycan content of 22.3 µg per scaffold. PGA constructs cultured in static conditions had the lowest cellularity. Cells had difficulty adhering to OPLA and the PLLA coating of PGA scaffolds; cellularity was inversely proportional to the concentration of PLLA used. PLLA coating did not prevent dissolution of the PGA scaffolds. All cell scaffold types and culture conditions produced non-uniform cellular distribution.Discussion/Conclusion. FLS-seeding of PGA scaffolds cultured in a rotating bioreactor resulted in the most optimal cell and matrix characteristics seen in this study. Cells grew only in the pores of the OPLA sponge, and could not adhere to the PLLA coating of PGA scaffold, due to the hydrophobic property of PLA. While PGA culture in a bioreactor produced measureable GAG, no culture technique produced visible collagen. For this reason, and due to the dissolution of PGA scaffolds, the culture conditions and scaffolds described here are not recommended for inducing fibrochondrogenesis in equine FLS for meniscal tissue engineering

SPECIFIC SPECULATIVE TYPE OF INVESTMENT

This research work has been concentrated on impact of social learning on the investment intensity. The investors can be faced with expected short-run profitability of new investment what can make inadequate influence on investor’s incentive to invest. The model what has bee used, supposed social environment of high investment activity thankfully to the speculative motive

Climate Change Has Beef with Federal Cattle Grazing

Increased emissions of greenhouse gases are causing the Earths climate to change producing extreme temperatures and dangerous conditions for mankind. Livestock is positioned at a unique juncture of the current and future fight against atmospheric temperature rise. These animals produce the very nutrients a growing world population needs to survive, and the meat they yield plays an important role in all world cultures. Unfortunately, the production of livestock is considered one of the most significant emitters of greenhouse gases, of which cattle is the largest contributor. Therefore, a balance must be struck between livestock production and preservation of the Earth. One way to rebalance this relationship would be to reform the federal cattle grazing permit system. Federal land in the Western United States contains hundreds of millions of acres and makes up over half the landmass of some states. The Bureau of Land Management and Forestry Service oversee most of the federal land in the West. On this land, these agencies operate grazing programs in which they allow private ranchers to apply for permits to graze cattle on the lands for a fee. The fee is based on an archaic formula that has not been updated in decades and is based on outdated economics of cattle grazing. As a result, the permit fee is far below market value, and the government operates the cattle grazing programs at a deficit of tens of millions of dollars annually. The subsidizing of cattle grazing on land owned by the American people, which directly exacerbates climate change, is wrong. Action should be taken to redress the impacts on the climate and the costs to the federal government. Modernizing the permit fee can be accomplished by a two-fold change. First, the minimum rate has to be raised to make certain the government is at least getting close to a fair price. This avenue was pursued but ultimately not accomplished in the Obama Administration. Second, the permits should be auctioned to the public for a price in excess of the minimum rate, and the permit length shortened to allow more frequent fee adjustment through auctions. Additionally, the increased revenue resulting from these changes should be allocated to efforts to mitigate cattle production\u27s effect on climate change

A Risk-Based Approach for Examining Vertical Separation Distances in On-Site Wastewater Treatment Sytems

Regulations regarding the use of on-site wastewater treatment systems in many states lack a sufficient scientific basis, which in many cases restricts the use of on-site systems, drives up cost, and restricts innovation of new treatment technologies. Of particular regulatory concern is the minimum vertical separation distance (VSD) located in the area between the trench bottom of the subsurface soil absorption system and any restricting or limiting layer. The minimum VSD needed for proper effluent treatment is based on many complex and interrelated factors regarding physical, chemical, and biological soil conditions at a particular site. Research has shown that depending on soil type and conditions, VSD between 1.5 feet and 4 feet is enough to adequately treat effluent yet many states use a one size fits all approach when setting regulations for on-site treatment systems. A stochastic mathematical model has been developed that provides an estimation of the probability that a contaminant concentration will reach a certain point below the trench bottom of the subsurface soil absorption system. This model has been incorporated into a simple, easy-to-use, Excel® based computer program that allows the user to evaluate the potential range of fecal coliform concentrations that may reach a specified groundwater or surface water location. This model has been developed to aid regulators, land use planners, and designers to quickly evaluate the associated risks of contamination from a specified on-site wastewater treatment system in a specified soi