We present experimental measurements and analysis of RF interference between a passive RFID system and a generic frequency hopping communications system in the 902 MHz to 928 MHz ISM radio band. ...Interference in both directions is considered, RFID to communications and vice-versa, and interference mitigation strategies are assessed. Variables of interest include transmission power, antenna locations and polarization, and frequency hopping channel bandwidth and dwell time. Among the findings are the susceptibility of the RFID backscatter link to sources operating within regulatory limits, characterization of the performance asymmetry between the systems, and the constructive effect of interference to RFID at low powers.
Abstract
This paper deals with the use of calcinated clay and micronized limestone as supplementary cementitious materials (SMCs) for preparation of blended Portland cement CEM II/B-M (Q-LL). Clay ...used in this study was calcinated at 700°C and pozzolanic activity after calcination was assessed using accelerated R3 pozzolanic test and modified Chapelle test. The influence of calcinated clay and limestone addition on mechanical properties and hydration process was investigated and an optimal ratio for 35% clinker replacement was found. Initial decrease of mechanical strength at early ages, caused by SCM addition, was almost compensated during maturation of the binder.
Differences in bone among racial/ethnic groups may be explained by differences in body size and shape. Previous studies have not completely explained differences among white, Asian, and Hispanic ...groups during growth. To determine racial/ethnic differences and predictors of bone mass in early pubertal girls, we measured bone mineral content (BMC) in white, Hispanic, and Asian sixth-grade girls across six states in the United States. We developed models for predicting BMC for the total-body, distal radius, total-hip, and lumbar spine for 748 subjects. For each of the bone sites, the corresponding area from dual-energy X-ray absorptiometry (DXA) was a strong predictor of BMC, with correlations ranging 0.78-0.98, confirming that larger subjects have more BMC. Anthropometric measures of bone area were nearly as effective as bone area from DXA at predicting BMC. For total-body, distal radius, lumbar spine, and total-hip BMC, racial/ethnic differences were explained by differences in bone area, sexual maturity, physical activity, and dairy calcium intake. Bone size explained most of the racial/ethnic differences in BMC, although behavioral indicators were also significant predictors of BMC.
High-quality PWO crystals for the PANDA-EMC Novotny, R W; Bremer, D; Dormenev, V ...
Journal of physics. Conference series,
01/2011, Letnik:
293, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The paper provides a status report on the crystal production and quality control of a major part of the PbWO4 crystals for the PANDA-EMC. The results confirm the excellent performance of the new ...generation of PWO-II. The mechanism of stimulated recovery provides an additional tool to recover radiation damage at room and low temperatures by applying an external infrared light source. Even on-line recovery can be considered if the photo sensor is insensitive in that particular wavelength region.
This paper deals with possibilities of application brick-grind-dust which is a secondary product from manufacturing of grinded bricks. This product is usually partially returned to brick ...manufacturing or buried on a land field site. The basic idea of using this material in systems based on cement comes from their mineral composition, origin and particle size. These materials are potentially pozzolan active, which is interesting for use in hydraulic binders. Also red colour of brick dust can be interesting for visual application. First physical and chemical properties of brick-grind-dust was studied, then binders based on the material and Portland cement were prepared. Mechanical properties of prepared binders were studied over time. Hydration of the selected binders was analysed with isothermal calorimetry.
Photoproduction of πmesons from nuclei Krusche, B.; Lehr, J.; Ahrens, J. ...
European physical journal. A, Hadrons and nuclei,
11/2004, Letnik:
22, Številka:
2
Journal Article
PDF
