5,201 research outputs found
Parametric analysis of microwave and laser systems for communication and tracking. Volume 2 - System selection
System selection criteria of microwave and laser systems for communication and tracking - Vol.
Monte Carlo aided design of the inner muon veto detectors for the Double Chooz experiment
The Double Chooz neutrino experiment aims to measure the last unknown
neutrino mixing angle theta_13 using two identical detectors positioned at
sites both near and far from the reactor cores of the Chooz nuclear power
plant. To suppress correlated background induced by cosmic muons in the
detectors, they are protected by veto detector systems. One of these systems is
the inner muon veto. It is an active liquid scintillator based detector and
instrumented with encapsulated photomultiplier tubes. In this paper we describe
the Monte Carlo aided design process of the inner muon veto, that resulted in a
detector configuration with 78 PMTs yielding an efficiency of 99.978 +- 0.004%
for rejecting muon events and an efficiency of >98.98% for rejecting correlated
events induced by muons. A veto detector of this design is currently used at
the far detector site and will be built and incorporated as the muon
identification system at the near site of the Double Chooz experiment
Experiment definition phase shuttle laboratory (LDRL-10.6 experiment): Shuttle sortie to elliptical orbit satellite
The following topics were reviewed: (1) design options for shuttle terminal, (2) elliptical orbit satellite design options, (3) shuttle terminal details, (4) technology status and development requirements, (5) transmitter technology, and (6) carbon dioxide laser life studies
Experiment definition phase shuttle laboratory, LDRL-10.6 experiment. Shuttle sortie to ground receiver terminal
System development and technology are described for a carbon dioxide laser data transmitter capable of transmitting 400 Mbps over a shuttle to ground station link
Thermoelectric properties of Bi2Sr2Co2O9 whiskers under hydrostatic pressure
We report the temperature dependence of thermopower (S) in the ab plane of Bi2Sr2Co2O9 {BC-222} single crystalline whiskers under high pressure up to 1.2 GPa. Special modifications were made to our high-pressure transport measurement system to improve the measurement accuracy of S for whiskers with high resistance. Pressure improved the contact resistance dramatically. We observed a slight decrease of S and four-wire electrical conductivity (sigma) under high pressure. As a result, the power factor (S2sigma) was decreased less than 20% by pressure. From the temperature dependence of sigma, the band gap of BC-222 whiskers increase very slightly under high pressure
Thermoelectric properties of Bi2Sr2Co2O9 whiskers under hydrostatic pressure
We report the temperature dependence of thermopower (S) in the ab plane of Bi2Sr2Co2O9 {BC-222} single crystalline whiskers under high pressure up to 1.2 GPa. Special modifications were made to our high-pressure transport measurement system to improve the measurement accuracy of S for whiskers with high resistance. Pressure improved the contact resistance dramatically. We observed a slight decrease of S and four-wire electrical conductivity (sigma) under high pressure. As a result, the power factor (S2sigma) was decreased less than 20% by pressure. From the temperature dependence of sigma, the band gap of BC-222 whiskers increase very slightly under high pressure
Parametric analysis of microwave and laser systems for communication and tracking. Volume 3 - Reference data for advanced space communication and tracking systems
Reference data for advanced microwave and laser communication and tracking systems - Vol.
Development and initial validation of the Northwick Park Therapy Dependency Assessment
Objectives: To describe the development and initial validation of the Northwick Park Therapy Dependency Assessment (NPTDA) as a measure of therapy interventions in neurorehabilitation
Literacy skills of Australian Indigenous school children with and without otitis media and hearing loss
This study examined the relationship between reading, spelling, and the presence of otitis media (OM) and co-occurring hearing loss (HL) in metropolitan Indigenous Australian children, and compared their reading and spelling outcomes with those of their non-Indigenous peers. OM and HL may hinder language development and phonological awareness skills, but there is little empirical evidence to link OM/HL and literacy in this population. Eighty-six Indigenous and non-Indigenous children attending pre-primary, year one and year two at primary schools in the Perth metropolitan area participated in the study. The ear health of the participants was screened by Telethon Speech and Hearing Centre EarBus in 2011/2012. Participants’ reading and spelling skills were tested with culturally modifi ed sub-tests of the Queensland University Inventory of Literacy. Of the 46 Indigenous children, 18 presented with at least one episode of OM and one episode of HL. Results indicated that Indigenous participants had significantly poorer non-word and real word reading and spelling skills than their non-Indigenous peers. There was no significant difference between the groups of Indigenous participants with OM and HL and those with normal ear health on either measure. This research provides evidence to suggest that Indigenous children have ongoing literacy development difficulties and discusses the possibility of OM as one of many impacting factors
Calibration of optical tweezers with positional detection in the back-focal-plane
We explain and demonstrate a new method of force- and position-calibration
for optical tweezers with back-focal-plane photo detection. The method combines
power spectral measurements of thermal motion and the response to a sinusoidal
motion of a translation stage. It consequently does not use the drag
coefficient of the trapped ob ject as an input. Thus, neither the viscosity,
nor the size of the trapped ob ject, nor its distance to nearby surfaces need
to be known. The method requires only a low level of instrumentation and can be
applied in situ in all spatial dimensions. It is both accurate and precise:
true values are returned, with small error-bars. We tested this experimentally,
near and far from surfaces. Both position- and force-calibration were accurate
to within 3%. To calibrate, we moved the sample with a piezo-electric
translation stage, but the laser beam could be moved instead, e.g. by
acousto-optic deflectors. Near surfaces, this precision requires an improved
formula for the hydrodynamical interaction between an infinite plane and a
micro-sphere in non-constant motion parallel to it. We give such a formula.Comment: Submitted to: Review of Scientific Instruments. 13 pages, 5 figures.
Appendix added (hydrodynamically correct calibration
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