Control of Crystal Size and Morphology of Mordenite

The shape and size of the crystals of mordenite, as well as the Si/Al ratio, have implications as regards industrial applications in hydrocarbon conversion and separation. The ratio between the incorporation yields of silicon and aluminum is inversely proportional to the alkalinity level. The size of mordenite crystals can be modified by a factor of 10 by appropriate aging of the silica source. The alkalinity of the synthesis system is an important factor affecting the morphology of the mordenite crystals, with flatter crystals being formed at low alkalinity.     

Modeling and Management of Batteries and Ultracapacitors for Renewable Energy Support in Electric Power Systems–An Overview

Abstract—Energy storage devices and systems are playing a major role in all electrical systems from small electronics devices and automotive systems to the utility grid. The main objective of this article is to review energy storage devices, management, control, interface, and demonstrations for electrical power systems. Various types of energy storage systems are discussed, but the main focus is on batteries and ultracapacitors. Different types of batteries and their electrical models are explained. Three major types of ultracapcitors are also discussed. The battery management system and its functions, controls, and hardware are discussed. Various power electronics-based interface systems for battery and ultracapcitor charging and discharging are presented. Applications of energy storage systems for utility applications, including renewable firming, power shifting, and ancillary services, are discussed.     

Short communication: A countrywide survey of antimicrobial-resistant indicator bacteria in Kosovo's dairy farms

The World Health Organization recently recognized the Republic of Kosovo as one of the highest consumers per capita of antibiotics for human use among non-European Union Eastern European countries; however, data are limited regarding antimicrobial usage and antimicrobial resistance in the livestock sector for this recently formed country. The objective of this study was to conduct the first nationwide survey of antimicrobial resistance phenotypes in indicator bacteria collected from dairy farms in Kosovo. Composite fecal samples were collected from 52 farms located within all 7 administrative districts of Kosovo in the summer of 2014. Isolation and characterization of the indicator bacteria Escherichia coli (n = 165) and Enterococcus spp. (n = 153) from these samples was achieved by culturing on selective/differential media with and without select antibiotics, followed by MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry-based identification and antimicrobial susceptibility testing using the disk diffusion method. When no selective pressure was applied in culture-based isolation, the majority of E. coli and Enterococcus spp. collected were resistant to ≤1 of 16 and ≤2 of 12 antibiotics tested, respectively. In contrast, E. coli and Enterococcus spp. isolated using sub-minimum inhibitory concentrations of cefoxitin, ciprofloxacin, or erythromycin were typically resistant to at least one and often multiple antibiotic types, which primarily consisted of certain β-lactams, quinolones, sulfonamides, phenicols, and tetracyclines for E. coli isolates and macrolides, tetracyclines, and rifamycins for enterococci isolates.     

Applying Minimum Night Flow to Estimate Water Loss Using Statistical Modeling: A Case Study in Kinta Valley, Malaysia

Minimum night flow (MNF) is a common method used to evaluate water loss in a water network. In 2010, the average percentage of non-revenue water for the state of Perak in Malaysia was 29.4 %, a figure which resulted in major financial, supply, and pressure losses, as well as excessive energy consumption. In this study, a statistical analysis of the water distribution network and a modeling of MNF were carried out to estimate water loss in Kinta Valley, Perak. Flow and pressure for 361 zones were monitored for 24 h using PrimeWorks software (version: 1.5.57.0). Thirty study zones were randomly selected from 361 zones. MNF was screened within the time band of 1:00 am to 5:00 am. A total of 20 factors for physical, hydraulic, and operational variables were selected and correlated with MNF (L/s). Multiple linear regression was used as a statistical technique to determine factors that contributed to MNF (L/s). Consequently, pipe length (m) and pipe age (year) were the main contributors to MNF (L/s). The statistical model was finalized with R-Sq 0.706 and then improved to R-Sq 0.779. Results of the study revealed that 84.9 % of MNF frequencies for the 30 study areas were found at the time band 2:15 am to 4:15 am; therefore, the mean MNF for each zone in 2010 was determined to be between 1:00 am and 5:00 am. Statistical analyses showed that number of connections, total length of pipe, weighted mean of age of pipe, and type of pipe (100 mm asbestos cement) contributed to MNF. Moreover, approximately 97.5 % of registered repairs were conducted on pipes with small diameters of less than or equal to 50 mm. Pipes within this size range are usually used as service pipes and service connections.     

Fluorescent multi-responsive cross-linked P(N-isopropylacrylamide)-based nanocomposites for cisplatin delivery

Magnetic, pH and temperature-sensitive, poly(N-isopropylacrylamide) (PNIPAM)-based nanocomposites with fluorescent properties were synthesized by free radical copolymerization-cross linking of NIPAM, N,N-dimethylaminoethyl methacrylate (DMAEMA) and 4-acrylamidofluorescein (AFA). The model anti-cancer drug, cisplatin (CDDP), was loaded into the resulted nanogel. For the production of CDDP-loaded nanocomposite, Fe₃O₄ magnetic nanoparticles (MNPs) and CDDP were loaded into the nanogel. Field-emission scanning electron microscopy (FE-SEM) indicated that the size of nanogel and CDDP-loaded nanocomposite were about 90 and 160?nm, respectively. The encapsulation efficiency of CCDP was found up to 65%. The loaded CCDP showed sustained thermal and pH-responsive drug release. A high level of drug release was observed under the conditions of low pH and high temperature. The lower critical solution temperature (LCST) of synthesized nanogel was about 40?°C. CDDP-loaded nanocomposite showed a volume phase transition from 282 to 128?nm at its LCST. Accordingly, in this study, the synthesized nanocomposite can be employed as a stimuli-responsive anti-cancer drug delivery system and the pH and temperature of solution have the potential to monitor the drug release.     

Factorial design analysis and optimisation of chitosan‐based nanogels as controlled release system for gentamicin

The aim of this study was preparation and optimisation of a controlled‐release delivery system to decrease the dose‐dependent side effects of gentamicin. Hydrogel nanoparticles composed of a polycationic polymer (chitosan) and an inorganic polyanion (sodium tripolyphosphate) were fabricated in the presence of gentamicin. An experimental design was drawn upon to determine the optimum condition of nanoparticle preparation. Various features of the nanoparticles including drug loading parameters, particle size distribution, zeta potential and in vitro drug release profile were evaluated. Ultimately, the antimicrobial activity of the gentamicin‐loaded nanoparticles was analysed by determination of the minimum inhibitory concentration (MIC) and the potency test. As a result, the nanocarriers with an average size of about 250 nm (unloaded) and 493 nm (gentamicin‐loaded) were obtained with unimodal distribution and a notable polydispersity index (≤0.3). The drug loading efficiency was between 28 and 32%. The gradual and sustained releases (∼90%) of gentamicin were achieved in 24 h. The MIC and potency test showed no significant decrease in the antibacterial activity of gentamicin‐loaded nanoparticles. The outcomes demonstrated that the optimised chitosan nanogels prepared in this study can be considered as a suitable carrier for a controlled release system.Inspec keywords: hydrogels, nanoparticles, drug delivery systems, particle size, electrokinetic effects, antibacterial activity, nanomedicineOther keywords: factorial design analysis, chitosan‐based nanogels, gentamicin, controlled‐release delivery system, hydrogel nanoparticles, polycationic polymer, inorganic polyanion, sodium tripolyphosphate, particle size distribution, drug loading parameters, zeta potential, in vitro drug release profile, antimicrobial activity, minimum inhibitory concentration, polydispersity index, drug loading efficiency, antibacterial activity