Microstructure of mechanically alloyed Nd16Fe76B8-magnets

High resolution electron microscopy and analytical electron microscopy wereused to characterize mechanically alloyed Nd₁₆Fe₇₆B₈ which were previously identified as isotropic and anisotropic magnets. In both samples, two rare earth-oxide phases, NdO and Nd₂O₃, and a boron-rich phase were observed. Two grain boundary phases, the NdFe₂-phase and a non-equilibrium Nd-rich phase, were clearly identified in the isotropic samples and seem to be responsible for their higher coercivity. Due to the alignment of the grains, the anisotropic materials possess a better squareness of the B-H loop and a higher energy product.     

A new, precharged, low-power logic family for GaAs circuits

We present a new precharged, low-power logic family in GaAs that operates at speeds comparable to DCFL and consumes about one-fourth the power of DCFL. It uses a 2 V power supply for operation and can be used in conjunction with the widely used DCFL circuits. The logic family allows us to build complex gates in one gate delay, provides better noise margins, and is less susceptible to load capacitances than an unbuffered DCFL gate, thus making it useful for standard-cell based designs. To verify the approach, we have designed and fabricated a fully functional test chip containing a precharged full adder     

Thermodynamic properties of binary liquid mixtures involving weak interactions Part 1. Excess volumes of binary mixtures of 1-chlorobutane with normal alkanols at 303.15 K

Chandramouli, J., Choudary, N.V., Krishnaiah, A. and Naidu, P.R., 1982. Thermodynamic properties of binary liquid mixtures involving weak interactions. Part 1. Excess volumes of binary mixtures of 1-chlorobutane with normal alkanols at 303.15 K. Fluid Phase Equilibria, 8: 87–92Excess volumes for binary mixtures of 1-chlorobutane with 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol have been determined at 303.15 K. V^E is positive over the whole range of composition for the mixtures of 1-chlorobutane with 1-propanol and 1-butanol. An inversion in the sign of V^E is observed over certain ranges of concentration of the halogenated alkane in the remaining four mixtures. The results are explained in terms of depolymerisation of hydrogen-bonded alcohol aggregates, decrease in dipolar association, and weak hydrogen-bonding interaction of the type Cl- - - HO between unlike molecules.     

Price dynamics in competitive agile spectrum access markets

We explore the price dynamics in a competitive market consisting of spectrum agile network service providers and users. Here, multiple self interested spectrum providers operating with different technologies and costs compete for potential customers. Different buyers or consumers may evaluate the same seller differently depending on their applications, operating technologies and locations. Two different buyer populations, the quality-sensitive and the price-sensitive are investigated, and the resulting collective price dynamics are studied using a combination of analysis and simulations. Various scenarios are considered regarding the nature and accuracy of information available to the sellers. A myopically optimal strategy is studied when full information is available, while a stochastic learning based strategy is considered when the information is limited. Cooperating groups may be formed among the sellers which will in-turn influence the group profit for those participants. Free riding phenomenon is observed under certain circumstances     

Synthesis of new 1,2-dideoxy C-linked carbo-β-amino acids and α/β-peptides with 11/9-helix,helix-turn and helix-turn-helix structures

The present study describes the synthesis of new C-linked carbo-β-amino acids [β-Caa_(1,2-ddx)], with a 1,2-dideoxy D-xylo furanoside side chain (a tetrahydro furan derivative). The stereochemistry at the newly created amine centers was determined by modified Mosher method. The (S)-β-Caa_(1,2-ddx) prepared from d-mannose diacetonide were utilized for the synthesis of 1:1 α/β-peptides with L-Ala. The conformational analysis (NMR, MD and CD) revealed the presence of 11/9-helix, helix induced helix-turn (HT) and helix-turn-helix (HTH) in these peptides. These side chains with tetrahydrofuran ring facilitated the formation of robust helix, unlike some other side chains from earlier studies.     

A study of the thermal properties of single jersey fabrics of cotton, bamboo and cotton/bamboo blended-yarn vis-a-vis bamboo fibre presence and yarn count

In this study, the thermal properties of 100% cotton, 50/50 cotton/bamboo and 100% bamboo single jersey fabrics with differing yarn linear density are evaluated and analysed. The linear densities of the yarns composing the fabrics are 20^s, 25^s, 30^s Ne_c and the twist level in the yarns is kept the same. An increasing the presence of bamboo fibre in the fabric causes a reduction in fabric thickness and GSM for all linear densities of yarn. Air permeability and water-vapour permeability also increase with increase in bamboo fibre content while both thermal conductivity and thermal resistance show a decreasing trend. As the constituent yarn gets finer, fabric air and water-vapour permeability both increase in value while the thermal conductivity falls.