Optimized and low-complexity power allocation and beamforming with full duplex in massive MIMO and small-cell networks

The Journal of Supercomputing - By combining massive multiple-input and multiple-output (Ma-MIMO) and small-cell approaches, it is possible to improve the capacity of the network, with the features...     

Thermopower of YBa2Cu3O7-δ–Ag Composites

The percolation behavior of normal-state thermopower, resistivity, and superconductivity have been studied in YBa₂Cu₃O_7-δ─Ag (YBCO─Ag) composite systems. The normal-state resistivity and thermopower show a percolation threshold at a Ag volume fraction ( V _Ag) of 20% to 30%, whereas the superconducting network shows a threshold at a V _Ag of ≅70% to 80%. The results obtained from this study show that the YBCO─Ag composite obtained from Ag₂O and YBCO powders is uniformly distributed with Ag and YBCO remaining as separate phases without changing their characteristics. The measurements of thermopower indicate that the normal-state thermopower and phonon-drag thermopower are affected by the Ag addition. The stability of YBCO is increased when it is in composite form.     

β-Cyclodextrin-Mediated Removal of Soy Phospholipids from the Air–Water Interface

Binding of soy phosphatidylcholine (PC) and phosphatidylinositol (PI) with β-cyclodextrin (βCD) was studied using a spread monolayer technique at the air–water interface. First, surface pressure (π) versus surface concentration (Γ) isotherms of both PC and PI were characterized by forming spread monolayers on an aqueous subphase. PC and PI monolayers reached saturation at Γ of 1.98 and 3.24 μmol/m², respectively, at 25 °C. Subsequently, desorption of PC or PI from the spread monolayer in the presence of 2–14 mM βCD in the subphase was studied by measuring changes in π of monolayer. This desorption was indicative of a complex formation between βCD and PC or PI. The amount of PC or PI bound to βCD was determined by converting the net change in π to Γ by using π–Γ isotherms. From the saturated monolayers at the air water-interface, approximately 30% of PC and 50% of PI could be removed by 14 mM βCD. It was calculated that the free energy change required to transfer a PL from the monolayer at air–water interface to the aqueous phase in presence of βCD was decreased by 6–7 kcal/mol. Hydrolysis of PC in the monolayer by phospholipase A₂ (PLA₂) improved extraction efficiency of βCD. By incorporating 2.29 μM PLA₂ and 10 mM βCD in subphase, up to 80% of PC monolayer could be desorbed from the air–water interface. These results are discussed in terms of the potential use of βCD to remove PLs bound to soy protein.     

Effect of nonprotein polymers on water‐uptake properties of fish protein‐based hydrogel

The effects of nonprotein polymers on the water‐swelling properties of fish protein‐based hydrogel were studied. Inclusion of carboxymethyl cellulose (CMC), poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA), or guar gum at a 2.5% (w/w) level in an 80% ethylenediaminetetraacetic dianhydide (EDTAD)‐modified fish protein hydrogel (10% monomer concentration) significantly decreased the extent of water uptake of the hydrogel. Among these polymers, PVA exhibited the greatest inhibitory effect. The inhibitory effect of these polymers on the water uptake of fish protein hydrogel was apparently due to the thermodynamic incompatibility of these polymers with the fish protein gel network and the consequent effect on the extent of relaxation of the crosslinked polypeptide network. In contrast, inclusion of 60% EDTAD‐modified soy protein up to a level of 40% of the total protein in the gel did not affect the extent of the equilibrium water uptake of the gel. At higher levels, however, soy protein also decreased the amount of water uptake by the gel. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 45–51, 2002     

Prediction of axial velocity profiles and solids hold-up in a rotary kiln

Axial bed depth profiles were experimentally measured in a rotary kiln containing ilmenite particles under steady state and transient conditions. The variables include feed rate of solids, inclination and rotational speed of the kiln. and dam height. The variation of the axial velocity with kiln axis was estimated. The semi-experimental model proposed by Perron and Bui (1990) was modified to include the effect of the variables of the present study. The mean residence time of solids was estimated from the fractional hold-up and expressed in terms of the process variables. The transients induced by a step change in any of the operating conditions were measured as variation of discharge rate of solids with time.     

The lost-wax casting of icons, utensils, bells, and other items in South India

Indian artisans and craftsmen have long been masters at extracting and shaping metals and alloys, as proven by archaeological finds from the 2nd—3rd millennia B.C. For example, two well-known artifacts, castings of the dancing girl of Mohenjo Daro and the Mother Goddess of Adichanallur, Tamilnadu, depict a high degree of metallurgical knowledge. Those castings were formed by the lost wax process, which later was modified and became known as investment casting. In various parts of India, this age-old casting process is still being practiced, without any major modifications. This paper discusses details of the process used by the Indian artisans of Swamimalai, Tamilnadu, and Mannar, Kerala, South India in shaping copper-base alloys into icons and utensils, bells, and lamps.     

Myeloid Lineage Ablation of Phlpp1 Regulates M-CSF Signaling and Tempers Bone Resorption in Female Mice

Prior work demonstrated that Phlpp1 deficiency alters trabecular bone mass and enhances M-CSF responsiveness, but the cell types and requirement of Phlpp1 for this effect were unclear. To understand the function of Phlpp1 within myeloid lineage cells, we crossed Phlpp1 floxed mice with mice harboring LysM-Cre. Micro-computed tomography of the distal femur of 12-week-old mice revealed a 30% increase in bone volume per total volume of Phlpp1 female conditional knockouts, but we did not observe significant changes within male Phlpp1 cKO_LysM mice. Bone histomorphmetry of the proximal tibia further revealed that Phlpp1 cKO_LysM females exhibited elevated osteoclast numbers, but conversely had reduced levels of serum markers of bone resorption as compared to littermate controls. Osteoblast number and serum markers of bone formation were unchanged. In vitro assays confirmed that Phlpp1 ablation enhanced osteoclast number and area, but limited bone resorption. Additionally, reconstitution with exogenous Phlpp1 suppressed osteoclast numbers. Dose response assays demonstrated that Phlpp1^−/− cells are more responsive to M-CSF, but reconstitution with Phlpp1 abrogated this effect. Furthermore, small molecule-mediated Phlpp inhibition enhanced osteoclast numbers and size. Enhanced phosphorylation of Phlpp substrates—including Akt, ERK1/2, and PKCζ—accompanied these observations. In contrast, actin cytoskeleton disruption occurred within Phlpp inhibitor treated osteoclasts. Moreover, Phlpp inhibition reduced resorption of cells cultured on bovine bone slices in vitro. Our results demonstrate that Phlpp1 deficiency within myeloid lineage cells enhances bone mass by limiting bone resorption while leaving osteoclast numbers intact; moreover, we show that Phlpp1 represses osteoclastogenesis and controls responses to M-CSF.     

Elastic properties of phosphotungstate glasses

Elastic properties of potassium and lead phosphotungstate glasses have been investigated using ultrasonic velocity measurements. The composition dependence of elastic moduli in WO₃-K₂O-P₂O₅ glasses suggests that at low alkali oxide concentrations the atomic ring size increases by network modification, which results in the decrease of elastic moduli. In the highly modified regime, due to the presence of coulombic interaction, the rate of decrease of elastic moduli is reduced. In the WO₃-PbO-P₂O₅ glasses the behaviour of elastic moduli suggests that PbO behaves both as a network former and network modifier. The incorporation of PbO into the network is quantitatively determined by the concentration of P₂O₅ in the system. The results are consistent with the structural model proposed earlier, based on characterization studies.