222 research outputs found

    On the dimension of the space of integrals on coalgebras

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    We study the injective envelopes of the simple right CC-comodules, and their duals, where CC is a coalgebra. This is used to give a short proof and to extend a result of Iovanov on the dimension of the space of integrals on coalgebras. We show that if CC is right co-Frobenius, then the dimension of the space of left MM-integrals on CC is ≀dimM\leq {\rm dim}M for any left CC-comodule MM of finite support, and the dimension of the space of right NN-integrals on CC is ≄dimN\geq {\rm dim}N for any right CC-comodule NN of finite support. If CC is a coalgebra, it is discussed how far is the dual algebra C∗C^* from being semiperfect. Some examples of integrals are computed for incidence coalgebras

    Detection of holes in an elastic body based on eigenvalues and traces of eigenmodes

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    We consider the numerical solution of an inverse problem of finding the shape and location of holes in an elastic body. The problem is solved by minimizing a functional depending on the eigenvalues and traces of corresponding eigenmodes. We use the adjoint method to calculate the shape derivative of this functional. The optimization is performed by BFGS, using a genetic algorithm as a preprocessor and the Method of Fundamental Solutions as a solver for the direct problem. We address several numerical simulations that illustrate the good performance of the method.info:eu-repo/semantics/publishedVersio

    SENSOR ARRAY ABLE TO DETECT AND RECOGNISE CHEMICAL WARFARE AGENTS

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    In this paper we studied a device based on array of six different sensors with surface acoustic wave for detections and recognition of three chemical warfare agents (chloropicrin, soman and lewisite). The sensors are “delay line” type with a center frequency of 69.4 MHz. It presents an original algorithm to identify the nature and concentration of gas from a finite range of possible gases. Numerical program developed to implement this algorithm, provides to operators all the particulars of gas and an indicator of credibility of the results provided as a measure of the degree of disturbance of the signals received from sensors.SAW, chemical warfare agent, array of sensors, algorithm

    The Influence of Selected Meteorological Factors on Microbial Biomass and Mineralization of Two Organic Fertilizers

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    A mesocosm study was conducted in order to evaluate the effects of short-term rainfall and temperature variation on soil microbial biomass and bacteria to fungi ratio. In addition, the relation between the decomposition process of two organic fertilizers, cattle manure and barley straw, and the activity of soil microbial biomass was also studied. In order to assess the effect of biological activity on soil fertility the dynamics of soil pH, N-NO3-, N-NH4+, Corg and Nt during plant growing season was measured. The results suggest that short-term variation of climate had a significant effect on microbial biomass with dry periods distinguished by a reduced microbial biomass compared to wet periods. The ratio bacteria to fungi seems also to be sensitive to variations in rainfall and temperature regime, however further studies are required to draw a definitive conclusion. Regarding the type of fertilizer used, the straw treatments showed higher microbial biomass than the manure treatments, but higher decomposition rate was observed in manure fertilized soil. The effect of soil biological activity on soil pH was limited for both manure and straw treatments while the changes of the soil nitrate amounts are related to the microbial biomass. The study indicates that nitrate immobilization and mineralization processes are influenced by meteorological conditions and microbial biomass dynamics. In contrast, soil organic carbon and total nitrogen did not seem to be affected by variations in temperature, rainfall and microbial activity

    A high intensity radiation effects facility

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    The facility of the Michigan Ion Beam Laboratory at the University of Michigan has been upgraded to conduct high intensity radiation effects studies on materials. This upgrade is necessary to pursue higher radiation damage levels than the studies previously conducted. To achieve this capability a new volume ion source was installed which can produce several times more H−H− current than the previous duoplasmatron. We will describe the objectives of the research and the facility as well as applications to a variety of radiation damage problems. © 2001 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87674/2/687_1.pd

    Remote Monitoring and Control of Irradiation Experiments

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    As computer technology plays an increasing important role in particle accelerator facilities, instrumentation systems can be expected to include web connections and other remote capability features. The Michigan Ion Beam Laboratory at the University of Michigan in Ann Arbor has developed remote monitor and control capability by using a combination of commercial software packages and in‐house software development. Irradiation parameters such as ion current on the samples and apertures, sample temperature read from an optical pyrometer, and chamber pressure can all be accessed and monitored remotely through a web site, as can ion source parameters such as power supply currents and voltages or feed gas pressure. With administrator permission, the control parameters of the ion source or the readouts from the irradiation stage can be modified in real time during an experiment. A description will be given of the various ways in which this type of remote monitoring and control has been accomplished at the Michigan Ion Beam Laboratory. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87309/2/1046_1.pd
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