Thermal study of injection moulded ring

Application of CAD/CAM techniques to injection mould design is feasible and required now in view of the low cost of computers and the need to develop moulds in the shortest possible time. For this purpose a simpler thermal analysis of an injection mould is desirable, as most of the mould makers in Asia are in the category of small manufacturing units. This paper presents a thermal model of injection moulds for axisymmetric components using polar co-ordinates. This model could be utilised for studying the shrinkages, thermal residual stresses and cooling channels. A design example is presented to explain the method of application of the developed model.     

Influence of different maceration times on the anthocyanin composition of wines made from Vitis vinifera L. cvs. Boğazkere and Öküzgözü

The effect of three different maceration times (3, 6, and 10 days) on the anthocyanin composition of Boğazkere and Öküzgözü red wines produced in Turkey was studied. A high-performance liquid chromatographic method coupled with diode-array detection was used to identify and quantify anthocyanin compounds of the wines. Fourteen different anthocyanin compounds were detected in Boğazkere wines while the Öküzgözü wines had thirteen compounds. It was observed that the concentration of anthocyanin compounds of the Boğazkere wines was much higher compared to the Öküzgözü wines. Malvidin-3-glucoside and its acylated esters were the major anthocyanins in both wines. It was observed that the amount of the total anthocyanin compounds in both wines increased to the maximum value within 6 days of the skin maceration time.     

Bile salt deconjugation and cholesterol removal from media by Lactobacillus strains used as probiotics in chickens

BACKGROUND: Bile salt deconjugation by Lactobacillus strains is often closely linked to bile tolerance and survival of the strains in the gut and lowering of cholesterol in the host. The present study investigated the deconjugation of bile salts and removal of cholesterol by 12 Lactobacillus strains in vitro. The 12 strains were previously isolated from the gastrointestinal tract of chickens. RESULTS: The 12 Lactobacillus strains could deconjugate sodium glycocholate (GCA, 16.87–100%) and sodium taurocholate (TCA, 1.69–57.43%) bile salts to varying degrees, with all strains except L. salivarius I 24 having a higher affinity for GCA. The 12 Lactobacillus strains also showed significant (P < 0.05) differences in their ability to remove cholesterol from the growth medium (26.74–85.41%). Significant (P < 0.05) correlations were observed between cholesterol removal and deconjugation of TCA (r = 0.83) among the L. reuteri strains (C1, C10 and C16) and between cholesterol removal and deconjugation of TCA (r = 0.38) and GCA (r = 0.70) among the L. brevis strains (I 12, I 23, I 25, I 211 and I 218). In contrast, although L. gallinarum I 16 and I 26 and L. panis C 17 showed high deconjugating activity, there was no correlation between cholesterol removal and deconjugation of bile salts in these strains. CONCLUSION: The results showed that the 12 Lactobacillus strains were able to deconjugate bile salts and remove cholesterol in vitro, but not all strains with high deconjugating activity removed cholesterol effectively. Copyright © 2009 Society of Chemical Industry     

Palladium stripping rates in PGM refining

This study investigates the stripping (back-extraction) of palladium from the perspective of mixer–settler hydrodynamics. A hydroxyoxime extractant and hydrochloric acid medium are used. Firstly, the palladium stripping rate (chemistry) is determined using a vigorously stirred laboratory unit cell. This increases with operating temperature and stripping acid concentration. At optimal chemical conditions (25 °C, 6 N HCl), the stripping rate is sufficiently fast for equilibrium to be reached within 5–10 minutes. Secondly, the palladium stripping rate (hydrodynamics) is determined using a pilot-scale mixer–settler. The mixer–settler is operated with a 4-bladed radial disc and a 6-bladed Rushton turbine impeller, over a range of impeller speeds corresponding to power intensities of 2 to 5 kW/m³. The palladium stripping rate increases with increasing impeller speed for both the radial disc and Rushton turbine impellers. The overall mass transfer coefficient also increases with increasing power intensity, up to power intensities 100% higher than those used in typical plant stripping mixer vessels. When benchmarked against the power intensity, not much difference between the two impellers is noted. The study concludes that the stripping of palladium by solvent extraction as used in the PGM industry can be improved by operating at higher power intensities.     

EFFECT of SALT, SUGAR and MONOSODIUM GLUTAMATE ON the VISCOELASTIC PROPERTIES of FISH CRACKER ("KEROPOK") GEL

Rheological and microscopic studies were carried out on the fish cracker ('keropok') gels. A hard gel is very important for the production of uniform, round, and thin slices of dried 'keropok' and easier for mechanical slicing. the addition of 2% salt in the 'keropok' gel increased the storage modulus (G'), and reduced loss tangent (tan ×= G/G'). an increase in the fish content in 'keropok' also increased the G' and reduced tan γ. Gels having higher values of storage modulus G' and lower tan × values, indicative of a strong elastic network, showed well crosslinked fish muscle bundles in the microscopy studies. In the absence of salt, the fish protein appeared to be in lumps and this has resulted in low storage modulus G' and higher tan × values. Lower the temperature of the gel to 5C will result in 5–6 fold increase in the G' value.     

Characterisation of mechanical and thermal properties of epoxy grouts for composite repair of steel pipelines

The mechanical and thermal properties of the grouts are critical to their potential application as infill materials in structural repair. In this paper, the mechanical and thermal behaviour of five epoxy based grouts were investigated to identify their prospects as a component of the composite repair for steel pipelines. The compressive strength and stiffness of the grouts are found to be 52–120 MPa and 1.7–11 GPa, respectively. The tensile, flexural and shear strengths of the grouts are found to be within the ranges of 11–32, 27–53, and 13–30 MPa, respectively. The tensile and flexural moduli range within 3–17, and 4–13 GPa, respectively. Thermal analysis of the grouts suggests that the glass transition temperature (T_g) within 60 and 90 °C which also provide the thermal applicability limits for the grouts in the composite repair of steel pipes. The development of compressive properties of three selected grouts over 28 days period was also investigated as well as the effect of the addition of coarse fillers.     

A novel chemometric strategy for the estimation of extra virgin olive oil adulteration with edible oils

A useful procedure for the qualitative and quantitative determination of vegetable oils (canola, hazelnut, pomace and high linoleic/oleic sunflower) as adulterants in commercial samples of extra virgin olive oil, has been developed. Partial least squares (PLS) was employed for the analysis of Fourier transform infrared spectroscopy (FTIR) spectral data of the blend oil samples. Calibration models were constructed for extra virgin olive oil purity, with wavelength selection in the infrared region, according to their predictive ability, with first derivative and mean centering used as data pretreatment. PLS models were internally validated by the leave-one-out procedure. The method developed was very suitable for the determination of modeled adulterants but it may also reveal an adulteration even if it does not derive from the adulterants employed in this study.     

Adsorptive capacity of spray-dried pH-treated bentonite and kaolin powders for ammonium removal

The effectiveness of ammonium (NH₄⁺) adsorption was investigated, using spray-dried, pH-treated bentonite, and kaolin as adsorbents. Each powder's adsorption capacity towards NH₄⁺ was examined after up to 120 min of sample exposure, and results were compared. The zeta potential values for bentonite samples were between ?1.1 and ?19.4 mV, while for kaolin samples, they were between ?35.7 and ?40.9 mV (pH range examined was 2–10). The adsorption isotherm for bentonite showed a fit with the Langmuir model. The pH 10-treated bentonite and as-received bentonite (dispersed as pH 10 in distilled water) showed the highest adsorption capacity towards NH₄⁺. Meanwhile, for kaolin, the adsorption capacity was low and observed only at low NH₄⁺ concentration (100 mg/L and 200 mg/L), with pH 10-treated kaolin showed the highest adsorption capacity.     

Adaptive Neuro-Fuzzy Inference System for diagnosis risk in dengue patients

Dengue disease is considered as one of the life threatening disease that has no vaccine to reduce its case fatality. In clinical practice the case fatality of dengue disease can be reduced to 1% if the dengue patients are hospitalized and prompt intravenous fluid therapy is administrated. Yet, it has been a great challenge to the physicians to decide whether to hospitalize the dengue patients or not due to the overlapping of the medical diagnosis criteria of the disease. Beside that physicians cannot decide to admit all patients because this will have major impact on health care cost saving due to the huge incident of dengue disease in the country. Even if the physicians managed to identify the critical cases to be hospitalized, most of the tools that have been used for monitoring those patients are invasive. Therefore, this study was conducted to develop a non-invasive accurate diagnostic system that can assist the physicians to diagnose the risk in dengue patients and therefore attain the correct decision. Bioelectrical Impedance Analysis measurements, Symptoms and Signs presented with dengue patients were incorporated with Adaptive Neuro-Fuzzy Inference System (ANFIS) to construct two diagnostic models. The first model was developed by systematically optimizing the initial ANFIS model parameters while the second model was developed by employing the subtractive clustering algorithm to optimize the initial ANFIS model parameters. The results showed that the ANFIS model based on subtractive clustering technique has superior performance compared with the other model. Overall diagnostic accuracy of the proposed system is 86.13% with 87.5% sensitivity and 86.7% specificity.     

Information transformation in a supply chain: a simulation study

We study the information transformation by simulating a multi-stage supply chain when the end customer's demand is a general autoregressive integrated moving average (ARIMA) process, and the information, represented in the form of orders, is propagated from downstream to upstream in the supply chain. Our simulation results indicate several important and novel phenomena that need further theoretical analysis: (1) the anti-bullwhip effect and the transition from the regular bullwhip effect; (2) the trend of information transformation at higher stages of a supply chain; (3) the impact of lead-time on information transformation and the so-called ‘lead-time paradox’. In this paper, we will demonstrate these aspects via extensive computational experiments.