Humidity effects on adhesion of nickel-zinc ferrite in elastic contact with magnetic tape and itself

The effects of humidity on the adhesion of Ni-Zn ferrite and magnetic tape in elastic contact with a Ni-Zn ferrite hemispherical pin in moist nitrogen were studied. Adhesion was independent of normal load in dry, humid, and saturated nitrogen. Ferrites adhere to ferrites in a saturated atmosphere primarily from the surface tension effects of a thin film of water adsorbed on the ferrite surfaces. The surface tension of the water film calculated from the adhesion results was 48 times 0.00001 to 56 times 0.00001 N/cm; the accepted value for water is 72.7 x 0.00001 N/cm. The adhesion of ferrite-ferrite contacts increased gradually with increases in relative humidity to 80 percent, but rose rapidly above 80 percent. The adhesion at saturation was 30 times or more greater than that below 80 percent relative humidity. Although the adhesion of magnetic tape - ferrite contacts remained low below 40 percent relative humidity and the effect of humidity was small, the adhesion increased considerably with increasing relative humidity above 40 percent. The changes in adhesion of elastic contacts were reversible on humidifying and dehumidifying

Solving the Bethe-Salpeter equation for bound states of scalar theories in Minkowski space

We apply the perturbation theory integral representation (PTIR) to solve for the bound state Bethe-Salpeter (BS) vertex for an arbitrary scattering kernel, without the need for any Wick rotation. The results derived are applicable to any scalar field theory (without derivative coupling). It is shown that solving directly for the BS vertex, rather than the BS amplitude, has several major advantages, notably its relative simplicity and superior numerical accuracy. In order to illustrate the generality of the approach we obtain numerical solutions using this formalism for a number of scattering kernels, including cases where the Wick rotation is not possible.Comment: 28 pages of LaTeX, uses psfig.sty with 5 figures. Also available via WWW at http://www.physics.adelaide.edu.au/theory/papers/ADP-97-10.T248-abs.html or via anonymous ftp at ftp://bragg.physics.adelaide.edu.au/pub/theory/ADP-97-10.T248.ps A number of (crucial) typographical errors in Appendix C corrected. To be published in Phys. Rev. D, October 199

DNA-viivakoodaus elintarvikkeiden aitoustutkimuksissa

Opinnäytetyön tarkoituksena oli ottaa käyttöön ja validoida DNA-viivakoodaus-menetelmä Elintarviketurvallisuusvirasto Eviralle. DNA-viivakoodaus oli alun perin ekologisiin tutkimuksiin kehitelty menetelmä, mutta pian siitä huomattiin olevan hyötyä myös muilla tutkimusalueilla, kuten elintarvikkeiden aitoustutkimuksissa. Elintarvikepetoksia ja etenkin mereneläviin kohdistuvia väärennöksiä paljastuu yhä enemmän maailmalla. Suomessa näitä väärennöksiä ei ole kovinkaan paljoa tutkittu aikaisemmin. DNA-viivakoodaus-menetelmä perustuu siihen, että genomista on valittu alue, jossa lajin sisällä emäsjärjestys vaihtelee mahdollisimman vähän ja eri lajien välillä suuresti. Lajit voidaan erottaa toisistaan viivakoodialueen sekvenssien perusteella. Eläinlajeilla käytetään usein mitokondriaalisen DNA:n sytokromi c oksidaasi 1 -geeniä (CO1) ja kasveilla kloroplastin maturaasi K (matK)- ja ribuloosi bisfosfaatti karboksylaasi iso alayksikkö (rbcL) -geenejä. Opinnäytetyön laboratorio-osuus suoritettiin pääosin Yhdysvaltain elintarvike- ja lääkevirasto FDA:n laatiman työohjeen mukaisesti. Kalanäytteestä eristettiin DNA, josta monistettiin PCR:llä tietty nukleotidijakso. PCR-tuote puhdistettiin ja sekvensoitiin. Sekvensoinnin tulokset käsiteltiin bioinformatiikan työkaluin ja saatuja sekvenssejä verrattiin sekvenssitietokantoihin, jolloin saatiin selville näytteen kalalaji. Menetelmän käyttöönotto onnistui hyvin. DNA-eristys onnistui, mikäli näytemäärä ei ollut liian suuri. Erilaiset matriisit, kuten savustettu tai suolattu kala, eivät aiheuttaneet ongelmia. Poikkeuksena olivat ainoastaan liian prosessoidut tuotteet, kuten öljyyn säilötty purkkikala. Työssä käytetyt alukkeet toimivat usealle lajille, ja lajintunnistus onnistui vähintään sukutasolle asti. Alustavien tutkimusten perusteella samat alukkeet ja menetelmä soveltuvat myös eläinlajien määritykseen.The purpose of this Bachelor’s thesis was to implement and validate a DNA barcoding method for Finnish Food Safety Authority Evira. DNA barcoding method was originally developed for ecological studies, but soon it was found to be useful in other areas of research as well, such as food authenticity studies. Increasing amount of food frauds, especially seafood forgeries have been found around the world. In Finland, these forgeries have not been studied intensively until recently. DNA barcoding method is based on analysis of a selected area in the genome. The selected genome area should have as little sequence variety as possible within a species and as much as possible between different species. Species can be identified by the sequences of the barcode region. The cytochrome c oxidase subunit 1 gene (CO1) from mitochondrial DNA is often used with animal identification, and maturase K (matK) and ribulose bisphosphate carboxylase large chain (rbcL) genes from the chloroplast are used when researching plants. The laboratory work in this thesis was carried out mainly in accordance with the standard operating procedure made by the U.S. Food and Drug Administration FDA. The DNA was extracted from the fish sample, and a specific nucleotide sequence was amplified from the DNA. The PCR product was purified and sequenced. The results of the sequencing were processed with bioinformatics tools, and the gained sequences were compared to sequence databases to identify the species of the fish sample. The implementation of this method was successful. DNA extraction succeeded if the sample was not too large. Different matrices, such as smoked or salted fish, did not cause problems. The only exceptions were too far processed products, such as fish canned in oil. The primers used in this thesis were functional in many species and the identification of the species was successful until the family level at least. On the bases of the preliminary studies, the same primers and method are also suitable for the identification of several animal species

Real-time Loss Estimation for Instrumented Buildings

Motivation. A growing number of buildings have been instrumented to measure and record earthquake motions and to transmit these records to seismic-network data centers to be archived and disseminated for research purposes. At the same time, sensors are growing smaller, less expensive to install, and capable of sensing and transmitting other environmental parameters in addition to acceleration. Finally, recently developed performance-based earthquake engineering methodologies employ structural-response information to estimate probabilistic repair costs, repair durations, and other metrics of seismic performance. The opportunity presents itself therefore to combine these developments into the capability to estimate automatically in near-real-time the probabilistic seismic performance of an instrumented building, shortly after the cessation of strong motion. We refer to this opportunity as (near-) real-time loss estimation (RTLE). Methodology. This report presents a methodology for RTLE for instrumented buildings. Seismic performance is to be measured in terms of probabilistic repair cost, precise location of likely physical damage, operability, and life-safety. The methodology uses the instrument recordings and a Bayesian state-estimation algorithm called a particle filter to estimate the probabilistic structural response of the system, in terms of member forces and deformations. The structural response estimate is then used as input to component fragility functions to estimate the probabilistic damage state of structural and nonstructural components. The probabilistic damage state can be used to direct structural engineers to likely locations of physical damage, even if they are concealed behind architectural finishes. The damage state is used with construction cost-estimation principles to estimate probabilistic repair cost. It is also used as input to a quantified, fuzzy-set version of the FEMA-356 performance-level descriptions to estimate probabilistic safety and operability levels. CUREE demonstration building. The procedure for estimating damage locations, repair costs, and post-earthquake safety and operability is illustrated in parallel demonstrations by CUREE and Kajima research teams. The CUREE demonstration is performed using a real 1960s-era, 7-story, nonductile reinforced-concrete moment-frame building located in Van Nuys, California. The building is instrumented with 16 channels at five levels: ground level, floors 2, 3, 6, and the roof. We used the records obtained after the 1994 Northridge earthquake to hindcast performance in that earthquake. The building is analyzed in its condition prior to the 1994 Northridge Earthquake. It is found that, while hindcasting of the overall system performance level was excellent, prediction of detailed damage locations was poor, implying that either actual conditions differed substantially from those shown on the structural drawings, or inappropriate fragility functions were employed, or both. We also found that Bayesian updating of the structural model using observed structural response above the base of the building adds little information to the performance prediction. The reason is probably that Real-Time Loss Estimation for Instrumented Buildings ii structural uncertainties have only secondary effect on performance uncertainty, compared with the uncertainty in assembly damageability as quantified by their fragility functions. The implication is that real-time loss estimation is not sensitive to structural uncertainties (saving costly multiple simulations of structural response), and that real-time loss estimation does not benefit significantly from installing measuring instruments other than those at the base of the building. Kajima demonstration building. The Kajima demonstration is performed using a real 1960s-era office building in Kobe, Japan. The building, a 7-story reinforced-concrete shearwall building, was not instrumented in the 1995 Kobe earthquake, so instrument recordings are simulated. The building is analyzed in its condition prior to the earthquake. It is found that, while hindcasting of the overall repair cost was excellent, prediction of detailed damage locations was poor, again implying either that as-built conditions differ substantially from those shown on structural drawings, or that inappropriate fragility functions were used, or both. We find that the parameters of the detailed particle filter needed significant tuning, which would be impractical in actual application. Work is needed to prescribe values of these parameters in general. Opportunities for implementation and further research. Because much of the cost of applying this RTLE algorithm results from the cost of instrumentation and the effort of setting up a structural model, the readiest application would be to instrumented buildings whose structural models are already available, and to apply the methodology to important facilities. It would be useful to study under what conditions RTLE would be economically justified. Two other interesting possibilities for further study are (1) to update performance using readily observable damage; and (2) to quantify the value of information for expensive inspections, e.g., if one inspects a connection with a modeled 50% failure probability and finds that the connect is undamaged, is it necessary to examine one with 10% failure probability

Application of transparent microperforated panels to acrylic partitions for desktop use: A case study by prototyping

There are various measures currently in place to prevent the spread of coronavirus (COVID-19); however, in some cases, these can have an adverse effect on the acoustic environment in buildings. For example, transparent acrylic partitions are often used in eating establishments, meeting rooms, offices, etc., to prevent droplet infection. However, acrylic partitions are acoustically reflective; therefore, reflected sounds may cause acoustic problems such as difficulties in conversation or the leakage of conversation. In this study, we performed a prototyping of transparent acrylic partitions to which a microperforated panel (MPP) was applied for sound absorption while maintaining transparency. The proposed partition is a triple-leaf acrylic partition with a single acrylic sheet without holes between two MPP sheets, as including a hole-free panel is important to prevent possible droplet penetration. The sound absorption characteristics were investigated by measuring the sound absorption in a reverberation room. As the original prototype showed sound absorption characteristics with a gentle peak and low values due to the openings on the periphery, it was modified by closing the openings on the top and sides. The sound absorption performance was improved to some extent when the top and sides were closed, although there remains the possibility of further improvement. For this study, only the sound absorption characteristics were examined in the prototype experiments. The effects during actual use will be the subject of future study

Characterizing Atacama B-mode Search Detectors with a Half-Wave Plate

The Atacama B-Mode Search (ABS) instrument is a cryogenic ($\sim$10 K) crossed-Dragone telescope located at an elevation of 5190 m in the Atacama Desert in Chile that observed for three seasons between February 2012 and October 2014. ABS observed the Cosmic Microwave Background (CMB) at large angular scales ($40<\ell<500$) to limit the B-mode polarization spectrum around the primordial B-mode peak from inflationary gravity waves at $\ell \sim100$. The ABS focal plane consists of 480 transition-edge sensor (TES) bolometers. They are coupled to orthogonal polarizations from a planar ortho-mode transducer (OMT) and observe at 145 GHz. ABS employs an ambient-temperature, rapidly rotating half-wave plate (HWP) to mitigate systematic effects and move the signal band away from atmospheric $1/f$ noise, allowing for the recovery of large angular scales. We discuss how the signal at the second harmonic of the HWP rotation frequency can be used for data selection and for monitoring the detector responsivities.Comment: 7 pages, 3 figures, conference proceedings submitted to the Journal of Low Temperature Detector