Optimization of wool mothproofing with nano TiO2 using statistical analysis

Wool, with excellent characteristics, has the problem of being fed on by the moth. Until now several chemicals have been introduced for mothproofing with some limitations. In this research, an optimized mothproofing of wool has been proposed with nano TiO₂ and citric acid by using Design-Expert software. Mothproofing was statistically investigated by measuring wool weight loss during feeding by the larvae of carpet beetle, Anthrenus verbasci. The analysis of variance was applied to obtain the optimum conditions for mothproofing. The damage intensity of wool fabrics was also observed with a digital camera. Further, the dyeing properties of the treated wool fabrics were examined through evaluating exhaustion of CI Acid Blue 113. Finally, the wool fabrics treated with optimized concentration of CA and 1.2% TiO₂ nanoparticles indicated the best protection against moths.     

Geometry of plain weave fabric under shear deformation. Part I: measurement of exterior positions of yarns

Behaviour of woven fabrics in all directions is important in some fabric applications. Dealing with geometrical deformation of fabric under shear stress is the main attempt of this paper. A method for detecting exterior positions of yarns in fabric, namely variation in warp-weft yarns angle and sett of yarns is developed in the present part. For this purpose, the fast Fourier transform (FFT) method is modified for detecting exterior position of yarns in sheared fabric. In an empirical work, two kinds of plain weave fabrics, cotton and polypropylene, are considered and specimens are prepared in different dimensions with identical aspect ration. Exterior positions of yarns in certain elongations are computed by proposed method for each specimen. It was found that the modified FFT technique is valid for evaluating exterior positions of yarns in sheared fabric. Moreover, it is observed that there is a critical state in behaviour of woven fabric under shear deformation. In subsequent parts, the treatment of fabric under shear deformation will be simulated and compared with results of present part.     

A new 1.4-GHz soil moisture sensor

Moisture content determination in agriculture and civil engineering is a common process which needs special sensors with high accuracy, durability and compatibility with the measurement environment. A new 1.4-GHz soil moisture sensor using microstrip transmission line is presented. The proposed sensor consists of two separate parts: (1) A sensor head, which is a microstrip transmission line to be placed in the soil, and (2) an electronic transceiver which sends a sinusoidal wave into the sensor head at one end of the transmission line, and receives the traveled wave from the other end. Transmitter is basically a Colpitts oscillator, and the receiver is a phase detector that measures the phase shift due to velocity variation caused by the moisture content of soil. At a certain frequency, the velocity of a microwave traveling through a media depends on the permittivity of that media. The proposed sensor is implemented and tested on one sample of typical soil. The main advantages of the proposed sensor are its high accuracy, quickness of measurement, its low cost and ease of implementation. Since the sensor has low power consumption, it can be recommended for low-power applications such as wireless sensor network.     

Prediction of mass transfer coefficients in a pulsed disc and doughnut extraction column

A study of the mass transfer performance for a pulsed disc and doughnut extraction column has been presented for a range of operating conditions. The mass transfer performance has been investigated for both directions of mass transfer. This study has examined the mass transfer coefficients which has incorporated the effects of back‐mixing in the continuous phase. The effect of operating variables including pulsation intensity and dispersed and continuous phase velocities on volumetric overall mass transfer coefficient has been investigated. The experiments showed that mixer‐settler, transition and emulsion regimes exist in the column depending on the pulse characteristics. In the present work, effective diffusivity is substituted for molecular diffusivity in the Gröber equation for estimation of overall mass transfer coefficients. The enhancement factor is determined experimentally and there from a single empirical correlation is derived for prediction of enhancement factor in terms of Reynolds number, holdup and Eötvös number for all operating regimes and each mass transfer direction. The experimental results are in very good agreement with the values calculated by the proposed equation. © 2011 Canadian Society for Chemical Engineering     

Optimisation of a chromatographic procedure for determining biogenic amine concentrations in meat and meat products employing a cation-exchange column with a post-column system

The aim of this study was to optimise and validate a chromatographic method for determining biogenic amine (BA) in meat and meat products separated by a cation-exchange column with a post-column system, using o-phthalaldehyde as a derivatising reagent. A perfect separation of nine BA (tyramine, histamine, β-phenylethylamine, putrescine, cadaverine, tryptamine, agmatine, spermidine and spermine) was obtained in 22 min. The conditions were: column Tª 40 °C and coil Tª 45 °C, pump flow rate 0.8 mL/min, pH phase A 6.33, B 5.63 and C 13.00. The method was adjusted linearly in a range of 0.10–12 mg/L with a correlation coefficient superior to 0.998. Detection and quantification limits were between 0.03–0.10 mg/L and 0.10–0.20 mg/L, respectively. Precision studies were satisfactory, with RSD less than 2% and meat extracts recovering over 98%. This method showed an appropriate, precise, fast and versatile procedure for determining nine BA simultaneously in different meat product matrices.     

Chemical compositions of the marine algae Gracilaria salicornia (Rhodophyta) and Ulva lactuca (Chlorophyta) as a potential food source

BACKGROUND: The nutritional compositions of two edible red (Gracilaria salicornia) and green (Ulva lactuca) seaweeds were determined to evaluate their possible uses as potential food ingredients. RESULTS: In general, these species contained limited amounts of lipids ranging between 0.99 and 2.00 g 100 g^?1 dry weight) and considerably high amount of minerals, especially in G. salicornia (38.91 g 100 g^?1 d.w.). The crude protein values varied between 9.58 and 10.69 g 100 g^?1 d.w. Amounts for total amino acids were 889.78 ± 22.64 mg g^?1 protein d.w. in G. salicornia and 543.3 ± 15.14 mg g^?1 protein d.w. in U. lactuca. The most abundant fatty acids were C12:0, C16:0, C20:4 ω6 and C22:5 ω3, in addition to C18:1 in G. salicornia. Both seaweed species were balanced sources of ω3 and ω6 fatty acids with a ratio of ω6/ω3 that varied between 1.2 and 1.17. Between the seaweeds investigated, high levels of K (2414.02‐11 380.06 mg 100 g^?1 d.w.) were observed and the amounts of Ca, Na and Fe were higher than those reported for land plants. CONCLUSIONS: Thus, G. salicornia and U. lactuca may be utilised as value‐added products for human nutrition purposes. Copyright © 2012 Society of Chemical Industry     

Seasonal prevalence of Vibrio species in retail shrimps with an emphasis on Vibrio parahaemolyticus

Seasonal prevalence of Vibrio species in shrimp samples from retail outlets in the South-western part of Iran was studied. A total of 300 samples were analyzed (75 samples in each season). Special attention was paid to the prevalence of total and pathogenic Vibrio parahaemolyticus. All the TCBS isolates were first identified to the genus level with PCR and then identified to the species level using a battery of biochemical reactions and tests. To investigate the pathogenicity of the isolated V. parahaemolyticus, multiplex PCR (tl, tdh and trh genes) was performed. Vibrios were detected during the whole investigation period, depending on the sampling season. They were detected in 18.6% of the winter samples, 64% of the spring samples, 70.6% of the summer samples and 41.3% of the autumn samples. Vibrio calviensis and Vibrio alginolyticus were dominant in samples of different seasons, with the average prevalence of 18.6% and 17.6%, respectively. V. parahaemolyticus was found in 4.0% of the winter samples, 13.3% of the spring samples, 18.6% of the summer samples and 8% of the autumn samples. During the period of this study, two tdh-positive strains were isolated, while no trh-positive V. parahaemolyticus strain was detected in samples of different seasons.     

Effect of Geometry, Joule Heating, and Critical Current on the Responsivity of MOD Superconducting Transition Edge Sensors

By fabrication of several bolometric detectors on the YBCO film made of Metal-Organic Deposition (MOD) and the effect of pattering and film parameters on the optical responsivity of transition edge sensors is investigated. The low cost nonfluorine (MOD) method has been applied to fabricate YBCO thin films with different patterning parameters. The measurement results of the optical responsivity versus modulation frequency up to 100 KHz for these devices are reported.     

A case study on suspended particles in a natural gas urban transmission and distribution network

Suspended particles in the natural gas transmission and distribution network of the city of Kerman, Iran were investigated. Particle concentration and size distribution were measured in different locations of the natural gas pipeline network. Particle samplings were carried out in two seasons: summer, when there is the lowest consumption, and winter, when there is the highest consumption of natural gas. Additional particle characterization was carried out by scanning electron microscopy coupled with energy dispersion X-ray (SEM/EDX) and X-ray diffraction(XRD) analyses. Particle concentration was found to be significantly higher in winter as compared to summer. The range of particle concentrations in summer was from 0.12 mg/Nm³ at the end of the pipeline to 4.7 mg/Nm³ at the network entrance, and from 0.30 mg/Nm³ to 22.1 mg/Nm³ in winter. Particle size distribution showed a higher frequency of smaller particles in winter than in summer. Larger particles were more likely to exist at the network entrance as compared to the exit. The average particle size ranged from 181 μm at the network end to 253 μm at the entrance in summer, and from 74 μm to 209 μm in winter. Particle characterization confirmed the presence of corrosion products in the suspended particles.