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

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

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

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

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

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

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

MATRIX CALCULATIONS OF CROATIAN NATIONAL ACCOUNTS

Prediction of amounts for Croatian National Accounts in this paper was made based on Indirect Rates of Growth and clearly shows that GDP is going to be the leader. The second largest amount will be Import as a National Account. This data has to be warning for the Croatian government, because Croatia will not be able to balance her deficit in international trade. Personal Consumption is the third largest amount and it means that Import will be higher than Personal Consumption. The fourth largest amount is Export, which will be more than 24 thousands B of Kunas behind the Import. Currently the foreign debt in Croatia came to $25 B, and a further increase of foreign debt is not a very positive sign. The only positive sign is coverage of Import with Export will be increased from 84% in 2003 to 88% in 2006. Gross Fixed Capital will not make extraordinary results and Government Consumption will be a very small amount