Equilibrium adsorption studies on removal of diclofenac sodium from aqueous solution using sawdust–polyaniline (SD–PAn) composites

In this work, equilibrium adsorption studies were carried out for the removal of antiinflamatory drug diclofenac sodium (DS) from aqueous solutions using sawdust–polyaniline(SD-PAn) composite as a potential sorbent at 20, 30, and 40°C. The composite sorbent was characterized by FTIR and SEM analysis. The particles exhibited porous and rough surface. The equilibrium uptake data was interpreted by the Langmuir, the Freundlic, the Temkin, and the Dubinin–Redushkevich (D -R) isotherm models. The maximum adsorption capacity was found to decrease with increase in temperature, thus indicating exothermic nature of the adsorption process. The thermodynamic parameters were evaluated using Langmuir, Flory–Huggins, Frumkin, and modified-Frumkin models. The negative values of ΔG_ads⁰ and ΔH⁰ indicated spontaneous and exothermic nature of the adsorption process, respectively. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci 125:1382–1390, 2012     

Photodechlorination of Aroclor 1254 in a Pilot-Scale Flow through Photoreactor

A novel pilot-scale flow through photoreactor has been designed with the intent to apply it in the field. The photoreactor uses a new plastic coil, instead of the conventional quartz tube. The photoreactor consists of six ultraviolet (UV) lamps with five around the coil and one at the center. Laboratory investigations were conducted using the photoreactor to treat neat Aroclor 1254 in alkaline isopropanol (IPA). The photoreaction is fast and efficient, even though the UV transmittances of the three plastic tubes investigated were lower than that of quartz. The reaction kinetics of the practical mixtures are explored. An analysis of five different constituent congeners of Aroclor 1254 indicated that higher congeners dechlorinate producing some of the lower ones, which are subsequently dechlorinated. The dechlorination of Aroclor 1254 was faster when water was added to the alkaline IPA–Aroclor solution.     

Performability modeling with UltraSAN

The utility of stochastic activity networks (SANs) for performability evaluation is discussed. UltraSAN, a new graphical, X-Windows-based software package that uses SANs, is described. UltraSAN incorporates three innovations: a class of SAN-level performability variables common to both analytical and simulation solution methods, methods that use the performability-variable choice and the SAN structure to greatly reduce the size of the stochastic process required for an analytical solution, and methods that use the performability-variable choice and the SAN structure to reduce the number of activities checked on each state change, thus speeding the simulation. The UltraSAN modeling framework, organization, and user interface are examined. Model construction and solution are described     

Dependent and multimode failures in reliability evaluation ofextra-stage shuffle-exchange MINs

Previous reliability evaluations for multistage interconnection networks (MINs) assumed that “all failures are statistically-independent and that no degraded operational modes exist for switches”, though these assumptions are not realistic. For example, researchers have described instances of statistically-dependent failures, or fault side-effects, in some MINs. This paper presents efficient algorithms for terminal, broadcast, and K-terminal reliability evaluation of the shuffle-exchange network with an extra stage (SENE), a redundant-path MIN, under assumptions that allow statistical-dependence between failures and degraded operational modes for switches. A modified shock-model incorporates failure statistical-dependency and multiple operational modes into the reliability evaluation. For an N×N SENE, the reliability algorithms and their run-times are: terminal and broadcast →O(log(N)), and K-terminal→O(|K|·log(N))     

On computer communication network reliability under programexecution constraints

The authors propose a technique to compute software system reliability (SSR). The method, called FARE (fast algorithm for reliability evaluation), does not require a priori knowledge of multiterminal connections (MCs) for computing the reliability expression. An effort is made to sole the problem of N-version programming by using the FARE approach. Owing to its short execution time and low memory requirement, FARE can be used to calculate the SSR of fairly large distributed systems     

Average lattices and aperiodic structures

Statistically averaged lattices provide a common basis to understand the diffraction properties of structures displaying deviations from regular crystal structures. An average lattice is defined and examples are given in one and two dimensions along with their diffraction patterns. The absence of periodicity in reciprocal space corresponding to aperiodic structures is shown to arise out of different projected spacings that are irrationally related, when the grid points are projected along the chosen coordinate axes. It is shown that the projected length scales are important factors which determine the existence or absence of observable periodicity in the diffraction pattern more than the sequence of arrangement.     

Pancreatic and duodenal injuries. Considerations on 40 observed cases

4-hydroxyandrostenedione is a steroidal, suicide substrate inhibitor of aromatase, which has been widely tested in postmenopausal breast cancer patients. It is highly specific with the only notable endocrine changes other than oestrogen suppression being a dose-related suppression of sex-hormone binding globulin when the drug is given orally (a reflection of the drug's minor androgenic activity). Intramuscular administration of 250 mg every second week is the schedule of choice. This achieves peripheral aromatase inhibition of about 85% and oestradiol suppression of about 65%. The drug is usually used second-line, after tamoxifen, with an overall response rate in unselected patients of 26%. Side-effects are minimal and consist almost entirely of local reactions at the site of injection. 4-hydroxyandrostenedione is therefore a useful new treatment option as the first selective aromatase inhibitor to have wide clinical availability.