Book Review: Heterogeneous Agent Systems

Autonomous Agents and Multi-Agent Systems -     

Thermal conductivity,heat capacity,and thermal diffusivity of selected commercial AlN substrates

The thermal transport properties of four commercially available AlN substrates have been investigated using a combination of steady-state and transient techniques. Measurements of thermal conductivity using a guarded longitudinal heat flow apparatus are in good agreement with published room temperature data (in the range 130–170 W · m^–1 · K^–1). Laser flash diffusivity measurements combined with heat capacity data yielded anomalously low results. This was determined to be an experimental effect for which a method of correction is presented. Low-temperature measurements of thermal conductivity and heat capacity are used to probe the mechanisms that limit the thermal conductivity in AlN.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

Electron injection into dense neon: A comparison with hydrogen and helium

As a probe of the electron-neon fluid surface barrier, hot electrons (~1 eV) obtained from thin-film cold-cathode emitters were injected into neon liquid and dense neon gas at temperatures below 77 K. In neon, at all densities including the liquid, we find a universal characteristic shape for the current attenuationi/i ₀ vs. E/N, in contrast to the cases of helium and hydrogen. The neon results are discussed in terms of various injection models and interpreted to imply a very long electron thermalization distance and an upper limit for the electron-neon surface barrier of 0.1 eV.Research supported through National Science Foundation Grant No. GH-37278.     

Three-ways crossover bioequivalence study of cephalexin in healthy Malay volunteers

Context: Although the general pharmacokinetics of cephalexin is quite established up-to-date, however, no population-based study on Cephalexin pharmacokinetics profile in Malay population has been reported yet in the literature.

Objective: The objective of this study was to investigate the pharmacokinetics and to compare the bioavailability of three cephalexin products, Ospexin® versus MPI Cephalexin® tablet and MPI Cephalexin® capsule, in healthy Malay ethnic male volunteers in Malaysia.

Material and method: A single dose, randomized, fasting, three-period, three-treatment, three-sequence crossover, open label bioequivalence study was conducted in 24 healthy Malay adult male volunteers, with 1 week washout period. The drug concentration in the sample was analyzed using high performance liquid chromatography.

Result: The mean (SD) pharmacokinetic parameter results of Ospexin® were C_max, 17.39 (4.15) μg/mL; AUC_0–6, 28.90 (5.70) µg/mL?*?h; AUC_0–∞, 30.07 (5.94) µg/mL?*?h; while, those of MPI Cephalexin® tablet were C_max, 18.29 (3.01) μg/mL; AUC_0–6, 30.02 (4.80) µg/mL?*?h; AUC0_0–∞, 31.33 (5.18) µg/mL?*?h and MPI Cephalexin® capsule were C_max, 18.25 (3.92) μg/mL; AUC_0–6, 30.04 (5.13) µg/mL?*?h; AUC_0–∞, 31.22 (5.29) µg/mL?*?h.

Conclusion: The 90% confidence intervals for the logarithmic transformed C_max, AUC_0–6 and AUC_0–∞, of Ospexin® versus MPI Cephalexin® tablet and Ospexin® versus MPI Cephalexin® capsule were between 0.80 and 1.25. Both C_max and AUC met the predetermined criteria for assuming bioequivalence. The pharmacokinetic profile of cephalexin in Malay population does not vary much from other world population.     

An evaluation of lignocellulosic solutions from OPEFB pulping process as demulsifiers for crude oil emulsion demulsification

Lignocellulosic solutions from oil palm empty fruit bunch (OPEFB) organosolv pulping process are used as demulsifiers for demulsification of crude oil emulsion using a model of water-in-oil emulsion of crude oil and brine solution. The results indicate that the demulsification performance was favored when only lignin compound was contained in the demulsifier. The phase separation capacity and rate were strongly affected by brine pH values, temperatures and demulsifier dosages. Complete phase separation capacity was achieved at the optimum conditions. The separated oil and water are qualified for refining process and water treatment, respectively, making it promising as a demulsifier.