Abstract
Many effort is exhausted lately in Egypt for adjusting data used to be introduced in a water distribution modeling software. One of these parameters that were very impressive in changing the results totally is the roughness coefficient (Hazen Williams C). The effect is seen obviously if the flows are increased so leads to higher head losses. These head losses would appear lower due to the fact that we are using uncertain value for roughness especially if we are using the standard roughness for new pipes.
The outcome from precise determination of roughness coefficient is adjusting water distribution network models to cope with real field values. The aim of this research is to relate C factor to head loss gradient so engineers can find a way to estimate C factor for aged pipes based in head loss gradient whatever was the network configuration.
The relationship of C factor to water quality parameters as chlorine decay is also discussed. Polynomial Equations relating chlorine concentration and Hazen Williams C factor is deduced.
A validation of Watergems leakage detection module (Darwin calibrator module) makes up a part of this research. And it is concluded that leak location can be found in a range of circle with a radius of 0.25km around point detected by Darwin Calibrator.
Equations of Colebrook and White are inserted in Watergems tables using user data extension tool to enter formulas to be calculated by software engine. This is a way provided to help get a fast estimate for roughness coefficient.
Keywords
C factor, leakage, chlorine decay, head loss gradient and aged pipes.

Recent trends indicate that dosage form drug delivery systems are especially suitable for achieving sustained or delayed release oral formulations with low risk of dose dumping, flexibility of blending to attain different release patterns as well as reproducibility. One of the approaches toward this goal was to develop and formulate extended release matrix oral tablets of itopride hydrochloride (ITO) as a highly water soluble drug and to increase its gastric retention time. Matrix tablets of (ITO) were developed using different methods such as: (wetting granulation, direct compression, and coating compression), by using different types of polymers (hydroxypropyl methyl cellulose (HPMC) K15M, hydroxypropyl cellulose (HPC) low viscosity, Eudragit ® RL100, and Carnauba wax). The prepared tablets were evaluated according to various physicochemical characteristics such as: weight and thickness variation, drug content, hardness, friability, and in vitro drug release. Tablet weight variation ranged from 395 ± 0.34 to 409 ± 1.78 mg, thickness ranged from 3.16 ± 1.37 to 3.74 mm, drug content ranged from 94.5 ± 1.01% to 106.2 ± 0.08%, friability ranged from 0.04 ± 0.69 to 0.84 ± 0.45, and hardness ranged from 5.25 ± 0.25 to 8.80 ± 0.4 Kg/cm 2. Results indicated that drug release depended upon method of preparation and polymer type. Furthermore, in vivo testing of the optimum sustained release tablet formulation (F23) using coating compression by HPMC as coat was performed in human subjects, and determined and compared to that of a commercial oral tablet (Ganaton ®) as a reference formulation. The obtained the maximum plasma concentration (C max) and the area under the curve from zero to infinity (AUC ( 0-∞) values were higher following formulated tablet administration than after Ganaton ® administration. The percentage relative bioavailability of ITO from the selected formula in human volunteers was found to be 243% compared to Ganaton ®.

The purpose of this study is to increase the lag time and prevent release of budesonide, a corticosteroid drug used in Crohn's disease for the first 5h and efficiently deliver it to the colon. Eudragit S100 spray-coated capsules and pulsatile systems using tablet plugs of cellulose acetate butyrate (CAB), HPMC K4M, guar gum, and pectin were prepared. Eudragit S100-coated capsules released 80.62% after 5h. In pulsatile systems, decreasing the ratio of the polymer significantly increased the rate and extent of drug release. Spray-coating with EUD S100 decreased the extent of drug release to 48.41%, 69.94%, 80.58%, and 45.23% in CAB, HPMC K4M, pectin, and guar gum, respectively; however, the entire amount was released in the target area. In the presence of bacterial enzymes, selected formulas showed nearly 100% release. X-ray imaging performed to monitor the capsules throughout the GIT in human volunteers of the capsules and spray-coated pulsatile systems with 25% guar gum in the plug showed bursting in the transverse and ascending colon, respectively. Both formulations showed marked reduction in induced rabbit colitis model. © 2011 Informa Healthcare USA, Inc.

Context: Fexofenadine hydrochloride (FXD) is a slightly soluble, bitter-tasting, drug having an oral bioavailability of 35%. The maximum plasma concentration is reached 2.6h (Tmax) post-dose. Objective: Developing taste-masked FXD orodispersible tablets (ODTs) to increase extent of drug absorption and reduce Tmax. Methods: Taste masking was achieved via solid dispersion (SD) with chitosan (CS) or sodium alginate (ALG). Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffraction were performed to identify physicochemical interactions and FXD crystallinity. Taste-masked FXD-ODTs were developed via addition of superdisintegrants (croscarmellose sodium or sodium starch glycolate, 5% and 10%, w/w) or sublimable agents (camphor, menthol or thymol; 10% and 20%, w/w) to FXD-SDs. ODTs were evaluated for weight variation, drug-content, friability, wetting, disintegration and drug release. Camphor-based (20%, w/w) FXD-ODT (F12) was optimized (F23) by incorporation of a more hydrophilic lubricant (Pruv®), visualized via scanning electron microscopy and evaluated for FXD pharmacokinetics in healthy volunteers relative to Allegra® tablets. Results: Based on gustatory sensation test, FXD-CS (1:1) and FXD-ALG (1:0.5) SDs were selected. Taste-masked FXD-ODTs had appropriate physicochemical properties. Drug release profiles of F23 and the phenylalanine-containing Allegra® ODT were similar (f2=96). Pores were observed following camphor sublimation. The pharmacokinetic studies proved F23 ability to increase extent of FXD absorption and reduce Tmax. © 2015 Informa Healthcare USA, Inc.

The purpose of this study is to increase the lag time and prevent release of budesonide, a corticosteroid drug used in Crohn's disease for the first 5h and efficiently deliver it to the colon. Eudragit S100 spray-coated capsules and pulsatile systems using tablet plugs of cellulose acetate butyrate (CAB), HPMC K4M, guar gum, and pectin were prepared. Eudragit S100-coated capsules released 80.62% after 5h. In pulsatile systems, decreasing the ratio of the polymer significantly increased the rate and extent of drug release. Spray-coating with EUD S100 decreased the extent of drug release to 48.41%, 69.94%, 80.58%, and 45.23% in CAB, HPMC K4M, pectin, and guar gum, respectively; however, the entire amount was released in the target area. In the presence of bacterial enzymes, selected formulas showed nearly 100% release. X-ray imaging performed to monitor the capsules throughout the GIT in human volunteers of the capsules and spray-coated pulsatile systems with 25% guar gum in the plug showed bursting in the transverse and ascending colon, respectively. Both formulations showed marked reduction in induced rabbit colitis model. © 2011 Informa Healthcare USA, Inc.

Map exploration is a fundamental problem in mobile robots. This paper presents a distributed algorithm that coordinates a team of autonomous mobile robots to explore an unknown environment. The proposed strategy is based on frontiers which are the regions on the boundary between open and unexplored space. With this strategy, robots are guided to move constantly to the nearest frontier to reduce the size of unknown region. Based on the PSO model incorporated in the algorithm, robots are navigated towards remote frontier after exploring the local area. The exploration completes when there is no frontier cell in the environment. The experiments implemented on both simulated and real robot scenarios show that the proposed algorithm is capable of completing the exploration task. Compared to the conventional method of randomly selecting frontier, the proposed algorithm proves its efficiency by the decreased 60% exploration time at least. Additional experimental results show the decreased coverage time when the number of robots increases, which further suggests the validity, efficiency and scalability.