883 research outputs found
Adaptive identification and control of structural dynamics systems using recursive lattice filters
A new approach for adaptive identification and control of structural dynamic systems by using least squares lattice filters thar are widely used in the signal processing area is presented. Testing procedures for interfacing the lattice filter identification methods and modal control method for stable closed loop adaptive control are presented. The methods are illustrated for a free-free beam and for a complex flexible grid, with the basic control objective being vibration suppression. The approach is validated by using both simulations and experimental facilities available at the Langley Research Center
Towards in-flow monitoring of fat content and fluid composition of dairy milk using microfluidic confocal Raman spectroscopy
Accurate time-domain gravitational waveforms for extreme-mass-ratio binaries
The accuracy of time-domain solutions of the inhomogeneous Teukolsky equation
is improved significantly. Comparing energy fluxes in gravitational waves with
highly accurate frequency-domain results for circular equatorial orbits in
Schwarzschild and Kerr, we find agreement to within 1% or better, which we
believe can be even further improved. We apply our method to orbits for which
frequency-domain calculations have a relative disadvantage, specifically
high-eccentricity (elliptical and parabolic) "zoom-whirl" orbits, and find the
energy fluxes, waveforms, and characteristic strain in gravitational waves.Comment: 6 pages, 9 figures, 2 tables; Changes: some errors corrected.
Comparison with Frequency-domain now done in stronger fiel
Measuring the quantum efficiency of single radiating dipoles using a scanning mirror
Using scanning probe techniques, we show the controlled manipulation of the
radiation from single dipoles. In one experiment we study the modification of
the fluorescence lifetime of a single molecular dipole in front of a movable
silver mirror. A second experiment demonstrates the changing plasmon spectrum
of a gold nanoparticle in front of a dielectric mirror. Comparison of our data
with theoretical models allows determination of the quantum efficiency of each
radiating dipole.Comment: 4 pages, 4 figure
Distribution and exploitation of oyster resources along the southeast and southwest coasts of India
The oysters are sedentary bivalve molluscs
which are gregarious and found in aggregates
attached by their right shell valve to hard
substrata, forming oyster beds or oyster banks
in varied environments, intertidal and subtidal
zones in shallow coastal waters, bays, creeks,
lagoons, backwaters and estuarine environment.
In India, natural stocks of oysters are exploited
on a small scale at a number of places as a
subsistence fishery and oysters are not cultured
commercially
Nanoscale surface roughness affects low Reynolds number flow: Experiments and modeling
Most micro-channel fabrication strategies generate nano-to-micro-scale, stochastic surface roughness. This inherent stochasticity can potentially be harnessed to direct microfluidic operations such as self-cleaning behavior and localized mixing. This work investigates the effect of stochastic nanoscale roughness on low to moderate Reynolds number Newtonian flow using concurrent modeling and experiments. We fabricate a microscopic channel with tailored hydrofluoric-acid-etched rough surfaces. Optical profilometry and micro-particle-image-velocimetry (micro-PIV) are used to characterize the surface roughness and flow field and is integrated with direct numerical simulation that resolves effects of nanoscale roughness. Results indicate that nanoscale roughness causes flow perturbations that extend up to the mid-plane and is insensitive to flow-rates
Untersuchungen zur Stabilisierung der frühen postnatalen Adaptationsvorgänge bei Kälbern in Mutterkuhhaltung - ein Beitrag zur Charakterisierung postnataler Anpassungsreaktionen
Ziel dieser Arbeit war es, die sensible Phase der ersten und frühen zweiten Adaptationsphase, von der Geburt bis zur 72. Lebensstunde, bei Kälbern fleischbetonter Rassen in einem geschlossenen Mutterkuhbestand zu untersuchen, um daraus folgend einen Beitrag zur Erstellung von nicht parametrischen Referenzbereichen für klinische und labordiagnostische Parameter für diese Zeitspanne zu leisten. Korrelationen zwischen klinischen und labordiagnostischen Parametern sollten aufgedeckt werden, um so klinisch relevante Beziehungen herstellen zu können
Eine Einschätzung der Vitalität anhand leicht zu erhebender ethologischer Befunde, wie erstes Kopfheben post natum, erstes sicheres Stehen und erste Kolostrumaufnahme wurde durchgeführt. Als Probanden standen insgesamt 115 mature Kälber verschiedener Rassen aus einem geschlossenen Mutterkuhbestand zur Verfügung. Die Untersuchung erstreckte sich von der Geburt bis zu 72 Stunden p. n.. Folgende 20 Parameter kamen dabei zur Auswertung: pH, Base Excess, Kohlendioxidpartialdruck, Hä¡tokrit, Gesamtprotein, Glukose, Triglyzeride, Cholesterin, Harnstoff, Kreatinin, Natrium, Kalium, Chlorid, Magnesium, AST, ALT, AP, GGT, GLDH und CK.
Die statistische Auswertung der Ergebnisse wurde unter Berücksichtigung der Faktoren Alter, Rasse, Geschlecht und Geburtsart der Kälber sowie Geburtsziffer des Muttertieres vorgenommen. Die einzelnen Messgrössen bis auf das Plasmachlorid wurden über den Untersuchungszeitraum hochsignifikant (p < 0,001) durch das Alter beeinflusst. Einflí²í³¥ der Rasse zeigten sich im Verlauf des Blut-pH-Wertes (p <= 0,01), des Base Excess (p <= 0,05) sowie der Enzyme ALT (p <= 0,05) und GLDH (p <= 0,05).
Das erste sichere Stehen post natum wurde schwach signifikant durch das Geschlecht (p <= 0,05) beeinflusst. Die Parameter pH-Wert (p <= 0,05) und Kohlendioxidpartialdruck (p <= 0,01) im venösen Blut sowie die Blutglukose (p <= 0,01) zeigten bis zum dritten Lebenstag ebenfalls Einflüsse durch das Geschlecht der Kälber.
Die Geburtsart übte einen signifikanten Einfluss auf die ethologischen Parameter des ersten Stehens (p <= 0,01) und des ersten Saugens post natum (p <= 0,01) aus, die Einstufung nach APGAR wurde sogar hoch signifikant (p <= 0,001) durch die Geburtsart beeinflusst. Labordiagnostisch konnte ein signifikanter Einfluss auf die CK-Aktivität (p <= 0,01) ermittelt werden. pH-Wert, Kaliumkonzentration und AST-Aktivität erfuhren schwach signifikante (p <= 0,05) Beeinflussungen durch die Art der Geburt.
Die Parität der Muttertiere, beeinflusste die Geburtsart signifikant (p <= 0,01). Ebenso wiesen die Serumspiegel des Gesamtproteins (p <= 0,05), von Harnstoff (p <= 0,01), Kalium (p <= 0,05), ALT (p <= 0,05) und GLDH (p <= 0,05) Einflüsse der die Geburtsziffer auf.
Im Verlauf der AP-Aktivitäten zeigten sich hoch signifikante Wechselwirkungen (p <= 0,001) mit den verschiedenen Rassen. Das Geschlecht der Kälber wies ebenso hoch signifikante Wechselwirkungen (p <= 0,001) zur GLDH-Aktivität auf. Wechselwirkungen der Geburtsart und der Zeit waren bei den Messgrössen pH-Wert (p <= 0,001), Kohlendioxidpartialdruck (p <= 0,01), Base Excess (p <= 0,001), Hämatokrit (p <= 0,001), Harnstoff (p <= 0,05) und AST-Aktivität (p <= 0,05) statistisch nachweisbar. Auf die Parameter Harnstoff (p <= 0,001), Natrium (p <= 0,05), Kalium (p <= 0,05), Chlorid (p <= 0,05) und ALT-Aktivität (p <= 0,05) waren Wechselwirkungen der Geburtsziffer der Muttertiere von der Geburt bis zur 72. Lebensstunde darstellbar.
Die Körpertemperatur der Kälber korrelierte unmittelbar nach der Geburt signifikant (p <= 0,01) mit dem Blut-pH-Wert (r = -0,283) und dem Kohlendioxidpartialdruck (r = +0,284). Zum Base Excess bestand postnatal eine schwach signifikante (p <= 0,05) Korrelation (r = -0,193). Die Blutglukosewerte korrelierten unmittelbar post natum schwach signifikant (p <= 0,05) mit dem Blut-pH (r = -0,207), dem Kohlendioxidpartialdruck (r = +0,089) und dem Base Excess (r = 0,210). Das erste Kopfheben post natum stand in hoch signifikantem (p <= 0,001) Zusammenhang mit der Vitalitätseinschätzung nach APGAR. Das erste Stehen zeigte einen signifikante (p <= 0,01) und der Zeitpunkt der ersten Kolostrumaufnahme noch einen schwach signifikanten (p <= 0,05) Zusammenhang. Zur exakten Einschätzung der labordiagnostisch ermittelten Blutwerte bei neugeborenen Kälbern ist eine vom genauen Alter abhängige Erstellung von Referenzbereichen unter Berücksichtigung nicht parametrischer Referenzbereiche notwendig.The aim of the present study was to illustrate the sensitive time of the first and the early second adaptation period from birth to the 72. hour of life in different races of beef cattle in one herd. Furthermore non parametric reference values for clinical and laboratory diagnostic parameters for this period of adaptation were described. Another aim was to find correlations between clinical and laboratory parameters to show relations of clinical relevance.
Ethological findings such as: first raising of the head post natum, first firm standing and colostrum intake were evaluated. For tests, a total of 115 mature calves of different races out of a close suckler cow management system herd was available. The evaluation was made from immediately after birth to 72 hours p. n.. The following 20 parameters were evaluated: pH, base excess, carbondioxide partial pressure, hematocrit, total protein, glucose, triglyceride, cholesterol, uric acid, creatinin, sodium, calium, potassium, chloride, magnesium, AST, ALT, AP, GGT, GLDH and CK.
When doing the statistical evaluation of the results factors such as: age, race, sex, kind of birth of the calves as well as the number of births given by the mother cow were considered.
The development of the single values over the time period of the research was highly influenced by the age (p <= 0.001). Influence of the race was found during the course of the blood-pH-value (p <= 0.01), of the base excess (p <= 0.05) and also of the enzymes ALT (p <= 0.05) and GLDH (p <= 0.05).
The time of first firm standing post natum as a qualifying factor was only weak significantly (p <= 0.05) influenced by the sex. The parameter blood-pH (p <= 0.05), blood glycose (p <= 0.01) and carbondioxide partial pressure (p <= 0.01) also proved influence of the sex of the calves during the first 3 days after birth.
The kind of birth had a significant influence on the ethological parameter of the first standing (p <= 0.01) and the first suckling post natum (p <= 0.01). When judging according to APGAR the correlation was even highly significant (p <= 0.001). In the laboratory diagnostics a significant influence on the CK-activity (p <= 0.01) could be found. pH-value, potassium concentration and AST-activity were weak significantly influenced (p <= 0.05) by the kind of birth.
The kind of birth was significantly influenced (p <= 0.01) by the fact how often a mother cow already had given birth to calves. The serum level of the total protein (p <= 0.05), of the uric acid (p <= 0.01), potassium (p <=0.05), ALT (p <= 0.05) and GLDH (p <= 0.05) also showed their correlation to the number of birth.
During the course of the AP activities of the different races significant interactions became obvious (p <= 0.001). The sex of the calves also showed highly significant interactions (p <= 0.001) towards the GLDH activity. Interactions of the kind and time of birth could also statistically be proven for the parameters: pH value (p <= 0.001), carbondioxide partial pressure (p <= 0.01), base excess (p <= 0.001), hematocrit (p <= 0.001), uric acid (p <= 0.05) and AST activity (p <= 0.05). For the parameters uric acid (p <= 0.001), sodium (p <= 0.05), potassium (p <= 0.05), chloride (p <= 0.05) and AST activity (p <= 0.05), an interaction could be found to the number of births given by the mother cow from the date of birth till the 72nd hour after birth.
Correlation was discovered between body temprature and blood glycose to pH, carbondioxide partial pressure and base excess. The body temperature of the calves correlated after birth directly and significantly (p <= 0.01) with the blood-pH-value (r = -0.283) and the carbondioxide partial pressure (r = +0.284). There existed a slightly significant (p <= 0.05) correlation (r = -0.193) to the base excess. The blood glycose values correlated directly post natum slightly significantly (p <= 0.05) with the blood-pH (r = -0.207) with the carbondioxide partial pressure (r = +0.089) and with the base excess (r = 0.210). The first raising of the head post natum was in a highly significant connection (p <= 0.001) with the judgement of the vitality by APGAR. The first standing up showed a significant (p <= 0.01) and the time of first intake of cholostrum still a weak significant (p <=0.05) correlation.
For the exact evaluation of the blood values derived from laboratory diagnostics for newly born calves, a table with values referring to the exact age and also considering the non-parameter values must be created
Ideal Spin Filters: Theoretical Study of Electron Transmission Through Ordered and Disordered Interfaces Between Ferromagnetic Metals and Semiconductors
It is predicted that certain atomically ordered interfaces between some
ferromagnetic metals (F) and semiconductors (S) should act as ideal spin
filters that transmit electrons only from the majority spin bands or only from
the minority spin bands of the F to the S at the Fermi energy, even for F with
both majority and minority bands at the Fermi level. Criteria for determining
which combinations of F, S and interface should be ideal spin filters are
formulated. The criteria depend only on the bulk band structures of the S and F
and on the translational symmetries of the S, F and interface. Several examples
of systems that meet these criteria to a high degree of precision are
identified. Disordered interfaces between F and S are also studied and it is
found that intermixing between the S and F can result in interfaces with spin
anti-filtering properties, the transmitted electrons being much less spin
polarized than those in the ferromagnetic metal at the Fermi energy. A patent
application based on this work has been commenced by Simon Fraser University.Comment: RevTeX, 12 pages, 5 figure
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