A Note on 1-Edge Balance Index Set

A graph labeling is an assignment of integers to the vertices or edges or both, subject to certain conditions. Varieties of graph labeling have been investigated by many authors [2], [3] [5] and they serve as useful models for broad range of applications

Formulation of Sustained-Release Diltiazem Matrix Tablets Using Hydrophilic Gum Blends

Purpose: To develop sustained release matrix tablets of diltiazem hydrochloride (DTZ) using karaya gum (K) alone or in combination with locust bean gum (LB) and hydroxypropyl methylcellulose (H).Methods: Matrix tablets of DTZ were prepared at different ratios of drug:gum (1:1, 1:2, and 1:4) and of the gum blends (K, K/LB, K/H and K/LB/H) by direct compression. The matrix tablets were evaluated for hardness, friability, in vitro release and drug content. The formulations were also characterised by scanning electron microscopy (SEM), Fourier transform infra-red spectroscopy (FTIR) and differential scanning calorimetry (DSC). A commercial diltiazem hydrochloride product Dilzem SR, was used as a reference for comparison Results: Tablets with only K or K/H had the highest mean dissolution time (MDT), the least dissolution efficiency (DE, 12 %), and released drug by swelling, diffusion and erosion mechanisms. Karaya gum or combinations with locust bean gum sufficiently controlled drug release, while combinations of KH and KLBH exhibited high and low drug release efficiency, respectively. SEM images of the tablets before and after dissolution showed morphological changes on the tablet surface while FTIR and DSC studies indicate that there was no chemical interaction between the drug and the polymers. Three of the formulations compared well with the reference (p < 0.05) in terms of release characteristics. Conclusion: The results of the study demonstrate that karaya gum alone or in suitable combination with locust bean gum and hydroxypropyl methylcellulose is suitable for formulating sustained-release matrix tablets of diltiazem.Key words: Karaya gum, Locust bean gum, Diltiazem hydrochloride, Sustained release, Hydroxypropyl methylcellulos

Effects of T-tabs and large deflections in DCB specimen tests

A simple strength of materials analysis was developed for a double-cantilever beam (DCB) specimen to account for geometric nonlinearity effects due to large deflections and T-tabs. A new DCB data analysis procedure was developed to include the effects of these nonlinearities. The results of the analysis were evaluated by DCB tests performed for materials having a wide range of toughnesses. The materials used in the present study were T300/5208, IM7/8551-7, and AS4/PEEK. Based on the present analysis, for a typical deflection/crack length ratio of 0.3 (for AS4/PEEK), T-tabs and large deflections cause a 15 percent and 3 percent error, respectively, in the computer Mode 1 strain energy release rate. Design guidelines for DCB specimen thickness and T-tab height were also developed in order to keep errors due to these nonlinearities within 2 percent. Based on the test results, for both hinged and tabbed specimens, the effects of large deflection on the Mode 1 fracture toughness (G sub Ic) were almost negligible (less than 1 percent) in the case of T300/5208 and IM7/8551-7; however, AS4/PEEK showed a 2 to 3 percent effect. The effects of T-tabs G sub Ic were more significant for all the materials with T300/5208 showing a 5 percent error, IM7/8551-7 a 15 percent error, and, AS4/PEEK a 20 percent error

Three-dimensional elastic-plastic finite-element analyses of constraint variations in cracked bodies

Three-dimensional elastic-plastic (small-strain) finite-element analyses were used to study the stresses, deformations, and constraint variations around a straight-through crack in finite-thickness plates for an elastic-perfectly plastic material under monotonic and cyclic loading. Middle-crack tension specimens were analyzed for thicknesses ranging from 1.25 to 20 mm with various crack lengths. Three local constraint parameters, related to the normal, tangential, and hydrostatic stresses, showed similar variations along the crack front for a given thickness and applied stress level. Numerical analyses indicated that cyclic stress history and crack growth reduced the local constraint parameters in the interior of a plate, especially at high applied stress levels. A global constraint factor alpha(sub g) was defined to simulate three-dimensional effects in two-dimensional crack analyses. The global constraint factor was calculated as an average through-the-thickness value over the crack-front plastic region. Values of alpha(sub g) were found to be nearly independent of crack length and were related to the stress-intensity factor for a given thickness

Cryptococcal immune reconstitution syndrome during steroid withdrawal treated with hydroxychloroquine

SummaryWe present a case report of cryptococcal immune reconstitution syndrome (IRS), in a non HIV infected patient, which we treated with hydroxychloroquine with successful results. We briefly review cryptococcal IRS, possible mechanisms of action of hydroxychloroquine as an immunomodulatory agent, and its potential role in management of IRS

Failure Detectors for Wireless Sensor-Actuator Systems

Wireless sensor-actuator systems (WSAS) offer exciting opportunities for emerging applications by facilitating fine-grained monitoring and control, and dense instrumentation. The large scale of such systems increases the need for such systems to tolerate and cope with failures, in a localized and decentralized manner. We present abstractions for detecting node failures and link failures caused by topology changes in a WSAS. These abstractions were designed and implemented as a set of reusable components in nesC under TinyOS. Results, which demonstrate the performance and viability of the abstractions, based on experiments on an 80 node testbed are presented. In the future, these abstractions can be extended to detect and cope with larger classes of failures in WSAS

Failure Detectors for Wireless Sensor-Actuator Systems

Wireless sensor-actuator systems (WSAS) offer exciting opportunities for emerging applications by facilitating fine-grained monitoring and control, and dense instrumentation. The large scale of such systems increases the need for such systems to tolerate and cope with failures, in a localized and decentralized manner. We present abstractions for detecting node failures and link failures caused by topology changes in a WSAS. These abstractions were designed and implemented as a set of reusable components in nesC under TinyOS. Results, which demonstrate the performance and viability of the abstractions, based on experiments on an 80 node testbed are presented. In the future, these abstractions can be extended to detect and cope with larger classes of failures in WSAS