Modeling health care facility location for moving population groups

Locating public services for nomadic population groups is a difficult challenge as the locations of the targeted populations seasonally change. In this paper, the population groups are assumed to occupy different locations according to the time of the year, i.e., winter and summer. A binary integer programming model is formulated to determine the optimal number and locations of primary health units for satisfying a seasonally varying demand. This model is successfully applied to the actual locations of 17 seasonally varying nomadic groups in the Middle East. Computational tests are performed on different versions of the model in order analyze the tradeoffs among different performance measures.     

Solubility of Core Materials in Aqueous Polymeric Solution Effect on Microencapsulation of Curcumin

Curcumin, the main active constituent of turmeric herb (Curcuma longa L.) have been reported to possess many medicinal values. The application of curcumin in dermatological preparations is limited by their intense yellow color property, which stains the fabric and skin. The objectives of this study were to reduce the color staining effect and enhance the stability of curcumin via microencapsulation using gelatin simple coacervation method. As for curcumin, ethanol and acetone were used as coacervating solvents. Curcumin was dispersed in ethanol while dissolved in acetone. Irrespective of the types of coacervating solvents used, microencapsulation resolved the color-staining problem and enhanced the flow properties and photo-stability of curcumin. Nevertheless, it was found that more spherical curcumin microcapsules with higher yield, higher curcumin loading, and higher entrapment efficiency were obtained with acetone than ethanol. The in vitro release of curcumin after microencapsulation was slightly prolonged. Further evaluation of the effects of solubility of core materials in coacervating solvent or polymeric aqueous solution using six different drug compounds, namely, ketoconazole, ketoprofen, magnesium stearate, pseudoephedrine HCl, diclofenac sodium, and paracetamol, suggested that the solubility of core materials in aqueous polymeric solution determined the successful formation of microcapsules. Microcapsules could only be formed if the core materials were not dissolved in the aqueous polymeric solution while the core materials could either be dissolved or dispersed in the coacervating solvent. In summary, microencapsulation not only circumvents the color-staining problem but also improved the stability and flowability of curcumin. The solubility of core material in aqueous polymeric solution plays a pivotal role in determining the successful formation of microcapsules.     

Chelating polymer granules prepared by radiation‐induced homopolymerization. II. Characterizations

Characterizations of chelating polymer adsorbent granules, incorporating amidoxime groups based on polyacrylonitrile (PAN), prepared for selective adsorption of uranium and likely other transition metals were studied. PAN was prepared by radiation‐induced polymerization technique and followed by amidoximation reaction. Conversion of PAN into polyacrylamidoxime (PAO) was studied by fourier transform infrared (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Morphology and thermal properties were also investigated. PAO was investigated in the separation of uranium from iron‐rich silicate rock samples and subjected to x‐ray fluorescence analysis (XRF). Selective adsorption for uranium and low affinity for alkali and alkaline earth metals were observed. The order of selectivity was found to be U ? Cu > Fe > Ni > Cr > V ? Ca > K. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1180–1187, 2006     

Development of Co-Culture Sourdough Systems for Improving Bread Quality and Delaying Staling

Six different blends of lactic acid bacterial cultures (Lactobacillus plantarum or Pediococcus cerevisiae) combined with Saccharomyces cerevisiae were used as co-culture for preparing sourdoughs. These prefermented sourdoughs were applied for producing pan breads. Acidification power, leavening ability, and microbial counts were conducted at different sour fermentation intervals. The highest acidification power in sourdoughs were recorded when 2% w_d/w_d (dry weight of cells/dry weight of flour) of either L. plantarum or P. cerevisiae was used in combination with 2% w_d/w_d S. cerevisiae. The leavening ability of sourdoughs was significantly (p < 0.05) enhanced by increasing the addition percentage of the studied LAB. According to staling rate, physical, and sensory characteristics, the best two treatments were obtained when the co-culture of 2% w_d/w_d S. cerevisiae with 4% w_d/w_d L. plantarum or 4% w_d/w_d P. cerevisiae were used. These two treatments were successfully applied in production of the flat bread. According to staling rate, physical and sensory characteristics, sourdough prefermented with 2% w_d/w_d S. cerevisiae combined with 4% w_d/w_d L. plantarum was the best treatment for preparing of flat bread. Overall the co-culture of L. plantarum and with S. cerevisiae might be a useful tool for preparing sourdough starter that was most effective for improving sensory and physical properties of both pan and flat bread. In addition it can help extend the shelf life by delaying bread staling and inhibiting mold spoilage.     

Widely tunable low-power high-linearity current-mode integrator built using DG-MOSFETs

A novel tunable current-mode integrator for low-voltage low-power applications is presented using mixed-mode TCAD simulations. The design is based on independently driven double-gate (IDDG) MOSFETs, a nano-scale four-terminal device, where one gate can be used to change the characteristics of the other. Using current-mirrors built with IDDG-MOSFETs, we show that the number of active devices in the tunable current-mode integrator, 16 in bulk CMOS design, may be halved, i.e. considerable savings in both total area and power dissipation. The integrator operates with single supply voltage of 1 V and a wide range of tunable bandwidth (~2 decades) and gain (~30 dB). This linear circuit has third-order harmonic distortion as low as ?70 dB in appropriate bias conditions, which can be set via the back-gates. The impact of tuning on the IDDG integrator and conventional design using symmetrically driven (SDDG) MOSFETs is comparatively studied. The proposed design is a good example for performance leverage through IDDG MOSFET architectures in analog circuits integral to future mixed-signal systems.     

Sintering and characterization of bismuth-oxide-containing zinc oxide varistors

Zinc oxide with different contents of Bi₂O₃ was prepared via a solid-state reaction to be used as varistors. Sintering was performed at 1200 and 1300 °C. Densification was achieved through liquid-phase sintering. A zincite phase, together with bismuth zinc oxide (Bi_7.65Zn_0.35O_11.83) and zinc bismuth oxide (Bi_25.33Zn_0.667O₄₀) phases, was formed at 1200 °C. A free Bi₂O₃ phase was still present at 1200 °C. Only the zincite phase was developed, and the other phases disappeared at 1300 °C. I–V characteristics show nonlinear behavior in all samples. The behavior was expected to be a result of the development of intergranular phases that crystallized from the Bi-rich liquid phase.     

Biological Performance of Calcium Pyrophosphate‐coated Porous Alumina Scaffolds

The present work aims at synthesis and study the bioactivity of porous alumina scaffolds coated with calcium pyrophosphate. Characterization of the formed calcium pyrophosphate and the coated scaffolds was assessed by X‐ray diffraction analysis and scanning electron microscope examinations. The in vivo studies revealed the ability of the porous scaffolds to regenerate bone tissue in femur defects of albino rats. Histological analysis showed that the defect is almost entirely filled with new bone. The formed bone is characterized as a mature bone. The produced bone grafts are intended to be used as bone substitute or bone filler.     

Effect of some thermal and chemical pre-treatments on smoked oyster mushroom quality

The effect of different thermal and chemical pre-treatments on quality and enzyme activities of smoked mushroom was investigated. Mushrooms were blanched (water and steam) and dipped in different concentrations of SO₂, H₂O₂, ethylenediaminetetraacetic acid (EDTA) and citric acid for 10 min before smoking. Enzyme activities, colour characteristics, microbiological and sensory examinations were carried out every 2 weeks up to 8 weeks of storage at 4 °C. Smoked mushroom pre-treated with sulphites (SO₂), H₂O₂ and steam blanching had the best colour values, better scores for all sensory characteristics and lower non-enzymatic browning compared with the other pre-treatments. Pre-treatment against total aerobic bacteria, yeast and moulds was the most effective when using citric acid, EDTA and steam, followed by smoking of mushroom. The most effective pre-treatments on quality and safety of smoked mushrooms were those using H₂O₂ and steam. It can be concluded that thermal and chemical treatments followed by smoking of mushroom reduce enzyme activities and are suitable for preserving mushrooms.     

Comparison of Statistical Deterioration Models for Water Distribution Networks

The use of water main break history as a proxy for condition has become common practice because of the high costs associated with direct assessments. Statistical deterioration models predict future water main breaks on the basis of historical patterns. Many municipalities are beginning to understand the value of utilizing water pipe break histories to manage their noncritical distribution networks via deterioration models. This paper presents a generic IDEF0 process model for developing water main deterioration models. Two common statistical deterioration models for water pipes are compared: rate-of-failure models (ROF) and transition-state (TS) models. ROF models extrapolate the breakage rate for a particular cohort of pipes and do not differentiate between the times between successive failures. On the other hand, transition-state models attempt to model the time between successive failures for pipes. This paper presents a comparison and analysis of ROF models and transition-state models by using a single data set for cast- and ductile-iron pipes in the City of Hamilton, Ontario, Canada. The paper compares the models’ ability to support breakage forecasting, long-term strategic planning, and short-term tactical planning. Best practices for pipe segmentation in support of water main deterioration models are presented.