Ranging Accuracy in Dynamic Spectrum Access Networks

Theoretical analysis of time-of-arrival (TOA)-based high-precision ranging algorithm for the dynamic spectrum access networks (DSANs) is performed. The asymptotic frequency-domain Cramer-Rao bound (CRB) of the ranging algorithm that takes the frequency-dependent feature (FDF) and phase of multipath components (MPCs) into account is derived through Whittle formula. The effects of FDF-MPCs and related parameters such as absolute bandwidth and operating center frequency on the ranging accuracy are investigated. The results show that the impacts of the FDF-MPCs on the ranging accuracy can be significant and it is recommended utilizing as large absolute bandwidth as possible at low operating center frequencies to obtain high-precision distance information of the users in the DSANs     

Power Doppler findings in nasopharingeal angiofibroma

Three fractions of polysaccharides that have high biological activity were extracted from Chinese bamboo leaves (Indocalamus Tesselatus) with 0.9% sodium chloride, 1% ammonium oxalate and 85% ethanol. Their component sugars were investigated by paper chromatography developed with n-butanol-pyridine-water (6:4:3 by vol), and by gas chromatography with crown ester stationary-phase-fused silica capillary column. Their monosaccharide compositions are different from each other with glucuronic acid, galactose, arabinose, mannose, glucose, and xylose (52, 18, 9, 7 and 6%, respectively) in one fraction, only glucuronic acid in another and glucuronic acid, fucose, arabinose and xylose (36, 31, 24 and 9%, respectively) in the third fraction. The protection effect of two polysaccharides against experimental hepatitis was studied in mice.     

The effect of etomidate induction on plasma cortisol levels in children undergoing cardiac surgery

Loyalty to one's extended family, a well-known Japanese tradition, has broken down following World War II. Child rearing in Japan, therefore, has been changing gradually and clearly. Traditionally, child rearing was taught to young mothers by the grandmothers. However, recently young couples are no longer living with their parents. Therefore, there are no advisers nor consultants available at home for their child rearing. Commercialism has certainly invaded the field of child rearing, including too many guidebooks and even baby-sitting companies. Children's lives have become much more competitive, busy and unnatural in comparison with those of 20-30 years ago. This might be one cause of the increased incidence of bullying, school phobia and psychological disorders in children.     

Ozonation of synthetic versus natural textile tannins: recalcitrance and toxicity towards Phaeodactylum tricornutum.

A sound in-plant pollution control strategy can only be defined by paying due attention to bio-recalcitrance and toxicity. In this context the levels of toxicity and inert COD introduced to textile dyebath discharges by two alternative auxiliary chemicals, namely natural tannin (NT) and synthetic tannin (ST), were investigated. The effect of 40 minutes ozonation at 1,000 mg h(-1) at pH 3.5 on the segregated effluent streams containing the above-mentioned tannin formulations was evaluated in terms of changes in toxicity and recalcitrance. The effect of ozonation on the COD distribution of raw and ozonated NT and ST samples according to their molecular weight cut-offs was also assessed. Both untreated tannin formulations exerted high acute toxicity towards marine microalgae Phaeodactylum tricornutum. Moderate decrease in the toxicity levels of both tannins was observed upon ozonation. The raw NT formulation with a COD content more than twice that of its alternative raw ST had an initially inert soluble COD content of only 25 mg/L, while the initially inert COD was 135 mg/L for ST. As the initially inert soluble COD content of NT was considerably lower, this textile auxiliary did not need chemical pretreatment to improve its biodegradability. On the other hand, the initially inert soluble COD content of ST was reduced by 70% by ozone pretreatment. In terms of residual COD contents achievable after passing through a biological treatment system, raw NT and pretreated ST formulations yielded 100 and 95 mg/L COD, respectively. The highest proportion of COD (46% for NT and 88% for ST) was found in the <1 kDa range. The same fraction increased to 93% for NT after ozonation, while for ST no significant change was observed in the COD distribution of the molecular weight cut-offs after ozonation.     

Hard iron boride (Fe2B) on 99.97 wt% pure iron

Some properties such as hardness and fracture toughness of boride formed on the 99.97 wt% pure iron were investigated. Boronizing was carried out in a solid medium, consisting of Ekabor powders of 5% B₄C as donor, 5% KBF₄ as an activator and 90% SiC as diluent at 800 °C for 2, 4 and 8 h. The dominant phase formed on the substrate was found to be Fe₂B that had a finger-like shape morphology. The hardness of boride on the 99.97% pure iron was over 1700HVN, while the hardness of pure iron was about 130HVN. It was found that the fracture toughness of boride formed on surfaces of 99.97% pure iron, depending on the process time, ranged from 3.59 to 3.83 MPa m^1/2. Depending on process time and temperature, the depth of the boride layer ranges from 22 to 43 μm, leading to a diffusion-controlled process.     

Scheme for reducing size of coefficient memory in FFT processor

Long fast Fourier transforms (FFTs) are required in applications such as orthogonal frequency division multiplexing, radars and sonars. It is highly desirable to reduce the size and power requirements of the FFT so as to realise single chip long FFT-based systems targeting portable applications. Presented here is a novel technique to reduce the coefficient memory almost by a factor of four by exploiting the relationships among the coefficient values thereby significantly reducing the area and power requirements of the hardware     

Castleman's disease. A case report

Angiofollicular lymph node hyperplasia or Castleman's Disease (CD) is a rare lymphoproliferative disorder that manifests itself as a local or generalized tumor-like condition affecting both lymph nodes and non-nodal tissues, usually in the chest and abdomen. Hyaline vascular and plasma cell types have been identified histologically. A new clinical form of CD with multisystemic involvement has been defined as multicentric Castleman's disease. It is very rare in childhood. In this paper we present an eight-year-old boy with multicentric Castleman's disease.     

Mixed-mode fracture performance of fibre reinforced concrete under impact loading

A test procedure developed to determine the mixed-mode impact resistance of fibre reinforced concrete materials is described. Results are presented from a series of experiments using a repeated drop-weight impact apparatus for the impact resistance of both polypropylene and steel fibre reinforced concrete. The behaviour of the mixed-mode specimen geometry was investigated under impact loading condition. The effect of the fibre types and contents on the impact fracture energy of the specimens was investigated. A close investigation was made of the positions and formations of the crack patterns. The fracture performance of the plain and fibre reinforced concrete was investigated with the proposed geometry using 1.0, 2.0 and 3.0% by weight in the case of steel fibre, and 0.1, 0.2 and 0.3% by weight in the case of polypropylene fibre.

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Resume Aux charges statiques auxquelles les structures en béton sont soumises s'ajoutent souvent des charges dynamiques, parfois significatives, qu'il convient de prendre en compte dans le calcul. Cet article décrit un mode opératoire visant à déterminer la résistance au choc en mode mixte de béton renforcé de fibres (FRC). On y présente les résultats d'une série d'essais utilisant une machine d'essai au choc à répétition (mouton) pour évaluer la résistance de béton renforcé de fibres d'acier et de fibres de polypropylène. On a mis au point une géométrie d'éprouvettes en mode mixte qu'on a soumises à des essais au choc, et on a étudié l'effet des types et des pourcentages de fibres sur la résistance des éprouvettes à la rupture par choc. On s'est aussi livré à une étude précise des emplacements et de la formation des fissures. On a examiné la résistance à la rupture de béton ordinaire et de béton de fibres dans la géométrie proposée avec des pourcentages de 1, 2 et 3% en poids de fibres d'acier, et de 0,1, 0,2 et 0,3% pour les fibres de polypropylène.

     

Appraisal of self, social environment, and state authority as a possible mediator of posttraumatic stress disorder in tortured political activists.

This study examined appraisal of self and others, as measured by semantic differential ratings of Police, State, Society, Family, Friend, Myself as a Man/Woman, and Myself as a Political Person, in 55 tortured political activists in Turkey, 55 nontortured political activists, and 55 nontortured, politically noninvolved controls. There were no remarkable differences between tortured and nontortured political activists; both groups differed from controls in having a more negative appraisal of the police and the state and stronger perceptions of danger, mistrust, and injustice in relation to state authority. Lack of beliefs concerning a "benevolent state" may have protected the survivors from the traumatic effects of state-perpetrated torture. Further research into the possible protective role of belief systems in posttraumatic stress disorder is needed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)