22,817 research outputs found
Self-protecting solid state isolated switch
Solid state switch has following capabilities: (1) Hybrid or IC from compatible with direct mounting on solar array substrate; (2) Continuous signal is not required to hold it in either on or off state; (3) Separate signal lines for on and off control; (4) Electrically isolated from input signals; and (5) Current surges will not cause switch failure
Pyrolysis of Wastewater Biosolids Significantly Reduces Estrogenicity
Most wastewater treatment processes are not specifically designed to remove micropollutants. Many micropollutants are hydrophobic so they remain in the biosolids and are discharged to the environment through land-application of biosolids. Micropollutants encompass a broad range of organic chemicals, including estrogenic compounds (natural and synthetic) that reside in the environment, a.k.a. environmental estrogens. Public concern over land application of biosolids stemming from the occurrence of micropollutants hampers the value of biosolids which are important to wastewater treatment plants as a valuable by-product. This research evaluated pyrolysis, the partial decomposition of organic material in an oxygen-deprived system under high temperatures, as a biosolids treatment process that could remove estrogenic compounds from solids while producing a less hormonally active biochar for soil amendment. The estrogenicity, measured in estradiol equivalents (EEQ) by the yeast estrogen screen (YES) assay, of pyrolyzed biosolids was compared to primary and anaerobically digested biosolids. The estrogenic responses from primary solids and anaerobically digested solids were not statistically significantly different, but pyrolysis of anaerobically digested solids resulted in a significant reduction in EEQ; increasing pyrolysis temperature from 100 °C to 500 °C increased the removal of EEQ with greater than 95% removal occurring at or above 400 °C. This research demonstrates that biosolids treatment with pyrolysis would substantially decrease (removal \u3e 95%) the estrogens associated with this biosolids product. Thus, pyrolysis of biosolids can be used to produce a valuable soil amendment product, biochar, that minimizes discharge of estrogens to the environment
Tunable cavity resonator with ramp shaped supports
A cavity for a hydrogen maser is described consisting of three parts which provide highly stable mechanical and thermal expansion characteristics for the cavity and ease of tuning. The three parts which are made of a glass ceramic material having a very small thermal expansion coefficient (1) a top plate, (2) a cylinder with three interrupted helical ramps at its bottom, and (3) a base which includes a bottom plate and three ramp lugs on which the helical ramps of the cylinder rest when the cylinder is placed on the base with the bottom plate in the cylinder. Cavity tuning is achieved by rotating the cylinder and thereby raising or lowering it on the base, which results in changing the cylinder volume by changing the distance between the bottom and top plates
A spacecraft digital stabilization and control system study
Digital techniques to increase reliability and accuracy of spacecraft control and stabilization system
Off-lattice Monte Carlo Simulation of Supramolecular Polymer Architectures
We introduce an efficient, scalable Monte Carlo algorithm to simulate
cross-linked architectures of freely-jointed and discrete worm-like chains.
Bond movement is based on the discrete tractrix construction, which effects
conformational changes that exactly preserve fixed-length constraints of all
bonds. The algorithm reproduces known end-to-end distance distributions for
simple, analytically tractable systems of cross-linked stiff and freely jointed
polymers flawlessly, and is used to determine the effective persistence length
of short bundles of semi-flexible worm-like chains, cross-linked to each other.
It reveals a possible regulatory mechanism in bundled networks: the effective
persistence of bundles is controlled by the linker density.Comment: 4 pages, 4 figure
Contemporary splinting practice in the UK for adults with neurological dysfunction: A cross-sectional survey
This article is made available through the Brunel Open Access Publishing Fund.Aim: To explore the contemporary splinting practice of UK occupational therapists and physiotherapists for adults with neurological dysfunction.
Method: Cross-sectional online survey of members of the Association of Chartered Physiotherapists in Neurology and College of Occupational Therapists Specialist Section Neurological Practice.
Results: Four hundred and twenty therapists completed the survey. Contracture management is the most common rationale for therapists splinting adults with neurological dysfunction. Other shared therapeutic goals of splinting include maintaining muscle and joint alignment, spasticity management, function, pain management and control of oedema. Considerable clinical uncertainty was uncovered in practice particularly around wearing regimens of splints. Most therapists have access to locally-derived splinting guidelines, which may contribute to this diversity of practice.
Conclusions: This study provides a unique insight into aspects of contemporary splinting practice among UK therapists, who belong to a specialist neurological professional network and work in a number of different health-care settings with adults who have a neurological condition. Study findings show a wide variation in splinting practice, thereby indicating a potential need for national guidance to assist therapists in this area of clinical uncertainty. Further research is required to establish best practice parameters for splinting in neurological rehabilitation
Risk Assessment of Grape Berry Moth and Guidelines for Management of the Eastern Grape Leafhopper
Several factors have prompted the reevaluation of control
recommendations for key pests of grapes in recent years.
First, the costs of insecticides and their application have risen
substantially. Growers who improve the efficiency of their
use of pesticides can realize significant savings in production
costs. Second, grape processors have responded to consumer
desires to minimize pesticide residues in food by promoting
judicious use of pesticides. Finally, increased governmental
restrictions regarding what pesticides can be used in vineyards
and how they may be used may increase the overall
difficulty that growers encounter when using pesticides. The
result of these factors is that while producers and processors
continue to require control of economically-damaging pests,
this now must be achieved with the least amount of pesticide
possible. The Grape Berry Moth Risk Assessment Program
was developed to address these concerns. In this publication
we describe how Risk Assessment can be used to maintain
acceptable control of grape berry moth and the Eastern grape
leafhopper while minimizing use of insecticides
Phase operators, phase states and vector phase states for SU(3) and SU(2,1)
This paper focuses on phase operators, phase states and vector phase states
for the sl(3) Lie algebra. We introduce a one-parameter generalized oscillator
algebra A(k,2) which provides a unified scheme for dealing with su(3) (for k <
0), su(2,1) (for k > 0) and h(4) x h(4) (for k = 0) symmetries. Finite- and
infinite-dimensional representations of A(k,2) are constructed for k < 0 and k
> 0 or = 0, respectively. Phase operators associated with A(k,2) are defined
and temporally stable phase states (as well as vector phase states) are
constructed as eigenstates of these operators. Finally, we discuss a relation
between quantized phase states and a quadratic discrete Fourier transform and
show how to use these states for constructing mutually unbiased bases
Anti-nutritional factors in canola produced in the Western and Southern Cape areas of South Africa
The development of low erucic acid, low glucosinolate cultivars of canola seed has led to the availability of a feed ingredient with considerable potential to replace soyabean meal in diets for all classes of farm animals. The sinapine and glucosinolate content of various canola cultivars cultivated in two areas of the Western Cape, South Africa were compared. There were no significant differences in sinapine content between the canola produced in the Western and Southern Cape (mean value of 9.95 mg sinapine/g grain). There were cultivar differences, with Varola 54 and Rainbow cultivars having significantly higher sinapine concentrations than Varola 50. There were no significant differences between the aliphatic, indolyl or aromatic glucosinolate content of the canola originating from either the Swartland or the Rûens areas in South Africa (mean value of 17.84 μmol total glucosinolates/g grain). There were significant differences in the total glucosinolate content of the various canola cultivars. Varola 44 and Hylite 200TT had the lowest total glucosinolate concentration and Varola 50 had the highest glucosinolate concentration. The results obtained seem to indicate a maximum dietary inclusion level of up to 14% for South African produced canola with an average of 17.83 μmol glucosinolates per gram to ensure optimal animal production. Keywords: Canola, anti-nutritional factors, sinapine, glucosinolate South African Journal of Animal Science Vol. 37 (1) 2007: pp. 45-5
OH (1720 MHz) Masers: A Multiwavelength Study of the Interaction between the W51C Supernova Remnant and the W51B Star Forming Region
We present a comprehensive view of the W51B HII region complex and the W51C
supernova remnant (SNR) using new radio observations from the VLA, VLBA,
MERLIN, JCMT, and CSO along with archival data from Spitzer, ROSAT, ASCA, and
Chandra. Our VLA data include the first 400 cm (74 MHz) continuum image of W51
at high resolution (88 arcsec). The 400 cm image shows non-thermal emission
surrounding the G49.2-0.3 HII region, and a compact source of non-thermal
emission (W51B_NT) coincident with the previously-identified OH (1720 MHz)
maser spots, non-thermal 21 and 90 cm emission, and a hard X-ray source.
W51B_NT falls within the region of high likelihood for the position of TeV
gamma-ray emission. Using the VLBA three OH (1720 MHz) maser spots are detected
in the vicinity of W51B_NT with sizes of 60 to 300 AU and Zeeman effect
magnetic field strengths of 1.5 to 2.2 mG. The multiwavelength data demonstrate
that the northern end of the W51B HII region complex has been partly enveloped
by the advancing W51C SNR and this interaction explains the presence of W51B_NT
and the OH masers. This interaction also appears in the thermal molecular gas
which partially encircles W51B_NT and exhibits narrow pre-shock (DeltaV 5 km/s)
and broad post-shock (DeltaV 20 km/s) velocity components. RADEX radiative
transfer modeling of these two components yield physical conditions consistent
with the passage of a non-dissociative C-type shock. Confirmation of the
W51B/W51C interaction provides additional evidence in favor of this region
being one of the best candidates for hadronic particle acceleration known thus
far.Comment: Accepted to Ap
- …