The mathematical theory of resonant transducers in a spherical gravity wave antenna

The rigoruos mathematical theory of the coupling and response of a spherical gravitational wave detector endowed with a set of resonant transducers is presented and developed. A perturbative series in ascending powers of the square root of the ratio of the resonator to the sphere mass is seen to be the key to the solution of the problem. General layouts of arbitrary numbers of transducers can be assessed, and a specific proposal (PHC), alternative to the highly symmetric TIGA of Merkowitz and Johnson, is described in detail. Frequency spectra of the coupled system are seen to be theoretically recovered in full agreement with experimental determinations.Comment: 31 pages, 7 figures, LaTeX2e, \usepackage{graphicx,deleq

How to overcome limitations of analytic solutions when determining the direction of a gravitational wave using experimental data: an example with the schenberg detector

It has been commonly assumed that analytic solutions can efficiently provide the direction of a gravitational wave (GW) once sufficient data is available from gravitational wave detectors. Nevertheless, we identified that such analytic solutions (based on the GW matrix reconstruction) present unforeseen theoretical and practical limitations (indeterminacies) and that for certain incoming directions they are unable to recover the latter. We present here important indeterminacy cases as well as a mathematical procedure that reduces such indeterminacies. Also, we developed a method that requires the least computational power to retrieve GW directions and which can be applied to any system of detectors able to reconstruct the GW matrix. As a test for the method, we used simulated data of the spherical, resonant mass GW detector Schenberg, which involves five oscillating modes and six transducer readouts. The results show that this method canceled indeterminacies out satisfactorily.University of Florida, Department of Physics 2001 Museum Road, 32611-8440 Gainesville, FL, USAFederal University of Sao Paulo, Department of Exact and Earth Sciences Rua Sao Nicolau 120, 09913-030 Diadema, SP, BrazilFederal University of Sao Paulo, Department of Exact and Earth Sciences Rua Sao Nicolau 120, 09913-030 Diadema, SP, BrazilWeb of Scienc

Computation of schenberg response function by using finite element modelling

Schenberg is a detector of gravitational waves resonant mass type, with a central frequency of operation of 3200 Hz. Transducers located on the surface of the resonating sphere, according to a distribution half-dodecahedron, are used to monitor a strain amplitude. The development of mechanical impedance matchers that act by increasing the coupling of the transducers with the sphere is a major challenge because of the high frequency and small in size. The objective of this work is to study the Schenberg response function obtained by finite element modeling (FEM). Finnaly, the result is compared with the result of the simplified model for mass spring type system modeling verifying if that is suitable for the determination of sensitivity detector, as the conclusion the both modeling give the same results.Sao Paulo Federal Institute Rua Pedro Vicente 625, 01109-010 Sao Paulo, SP, BrazilFederal University of Sao Paulo, Department of Exact and Earth Sciences Rua Sao Nicolau 120, 09913-030 Diadema, SP, BrazilFederal University of Sao Paulo, Department of Exact and Earth Sciences Rua Sao Nicolau 120, 09913-030 Diadema, SP, BrazilWeb of Scienc

Is zoning the solution to the UK housing crisis?

Although housing crises are rooted in both demand-side pressures and supply-side blockages, perceived regulatory impediments to building new homes are the softest target for policy reform. Critics argue that the English planning system’s case-by-case consideration of development applications hands excessive power to existing homeowners, who regularly veto those applications, thereby generating uncertainty for the development sector, impeding supply, and amplifying wealth inequalities. Drawing on interviews with planning and development actors, this paper explores the potential of rules-based zoning, in which consultation is restricted to plan-making and compliant applications proceed ‘automatically’, to address the supply sub-component of the housing crisis

Of Protein Size and Genomes

An approach for approximately calculating the number of genes in a genome is presented, which takes into account the average protein length expected for the species. A number of virus, bacterial and eukaryotic genomes are scrutinized. Genome figures are presented, which support the average protein size of a species as a criterion for assessing life complexity. The human gene distribution in the 23 chromosomes is investigated emphasizing the genomic rate, the mean 'exon' length, and the mean 'exons per gene'. It is shown that storing all genes of a single human definitely requires less than 12 MB.Comment: 6 pages, 1 figure, 5 table

Thermal connection and vibrational isolation: an elegant solution for two problems

Schenberg is a detector of gravitational waves resonant mass type, with a central frequency of operation of 3200 Hz. Transducers located on the surface of the resonating sphere, according to a distribution half-dodecahedron, are used to monitor a strain amplitude. To improve the performance of the detector it is essential to decrease the temperature, then it will be cooled down, this temperature could reach as low as 50 mK. This refrigerator produces vibration noise that could compromise the performance of Schenberg detector. In this work we the study such vibration noise and how it could be minimized proposing a new connection from the dilution refrigerator to the sphere suspension. The vibration attenuation is studied by finite element modeling (FEM) and an attenuation higher than 1024 is found, higher enough to note compromise the performance of Schenberg detector.Sao Paulo Federal Institute Rua Pedro Vicente 625, 01109-010 Sao Paulo, SP, BrazilFederal University of Sao Paulo, Department of Exact and Earth Sciences Rua Sao Nicolau 120, 09913-030 Diadema, SP, BrazilINPE Astrophysics Division, Sao Jose dos Campos, SP, 12227-010, BrazilFederal University of Sao Paulo, Department of Exact and Earth Sciences Rua Sao Nicolau 120, 09913-030 Diadema, SP, BrazilWeb of Scienc

Caracterização molecular de milho e sorgo para aplicação nos programas de melhoramento da Embrapa.

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