Foam Filters Used in Gravity Casting

Ceramic foam filters are normally used for reducing the velocity of liquid metal in the design of runner systems. In this study, four designs of the runner system with various orientations of foam filters were explored, and their effect on the velocity of the melt was estimated by a casting experiment and computational modeling. In the casting experiment, the free-fall trajectory and metal weighing methods were employed for measuring apparent velocity and flow rate, respectively. Using Forchheimer’s equation, a porous material such as a foam filter was simulated. The modeling result was validated by the experiment. For the efficient use of a foam filter in a running system with a high flow rate but low exit velocity, an optimized design is recommended.     

GMI,an Immunomodulatory Peptide from Ganoderma microsporum,Restrains Periprosthetic Joint Infections via Modulating the Functions of Myeloid-Derived Suppressor Cells and Effector T Cells

Periprosthetic joint infections (PJIs) caused by Staphylococcus aureus infection are difficult to treat due to antibiotic resistance. It is known that the biofilms from methicillin-resistant S. aureus (MRSA) promote expansion of myeloid-derived suppressor cells (MDSCs) to suppress T-cell proliferation and benefit bacterial infections. This study finds that GMI, a fungal immunomodulatory peptide isolated from Ganoderma microsporum, suppresses MDSC expansion to promote the proliferation of cytotoxic T cells. The enhancement is likely attributed to increased expression of IL-6 and TNF-α and reduction in ROS expression. Similar beneficial effects of GMI on the suppression of MDSC expansion and IL-6 expression are also observed in the whole blood and reduces the accumulation of MDSCs in the infected bone region in a mouse PJI infection model. This study shows that GMI is potentially useful for treating S. aureus-induced PJIs.     

A polynomial regression model for the response of various accelerating techniques on maize wine maturation

Statistical analysis was conducted to interpret the recently observed effects of various accelerating techniques on maize wine maturation (Chang, A. C. (2004). The effects of different accelerating techniques on maize wine maturation. Food Chemistry, 86, 61). Instead of the previously reported simple linear relationship between the concentrations of the key components of maize wine in the final product and the number of treatments or the dosage, various types of non-linear behaviours were observed. A general polynomial regression model is used to describe these behaviours, and the adjustable parameters were estimated from the experimental data. The performance of the proposed regression model, which plays a key role in the design of an efficient accelerating process, was satisfactory. Some specific variations of the key components of maize wine, as a function of the number of treatments or the dosage, were observed.     

Influence of fruit variety, harvest technique, quality sorting, and storage on the native microflora of unpasteurized apple cider

Apple variety, harvest, quality sorting, and storage practices were assessed to determine their impact on the microflora of unpasteurized cider. Seven apple varieties were harvested from the tree or the ground. The apples were used fresh or were stored at 0 to 4 degrees C for < or = 5 months and were pressed with or without quality selection. Cider yield, pH, Brix value, and titratable acidity were measured. Apples, postpressing apple pomace, and cider samples were analyzed for aerobic bacteria, yeasts, and molds. Aerobic bacterial plate counts (APCs) of ciders from fresh ground-picked apples (4.89 log CFU/ml) were higher than those of ciders made from fresh, tree-picked apples (3.45 log CFU/ml). Quality sorting further reduced the average APC to 2.88 log CFU/ml. Differences among all three treatment groups were significant (P < 0.0001). Apple and pomace microbial concentrations revealed harvest and postharvest treatment-dependent differences similar to those found in cider. There were significant differences in APC among apple varieties (P = 0.0001). Lower counts were associated with varieties exhibiting higher Brix values and higher titratable acidity. Differences in APC for stored and fresh apples used for cider production were not significant (P > 0.05). Yeast and mold counts revealed relationships similar to those for APCs. The relationship between initial microbial load found on incoming fruit and final cider microbial population was curvilinear, with the weakest correlations for the lowest apple microflora concentrations. The lack of linearity suggests that processing equipment contributed to cider contamination. Tree-picked quality fruit should be used for unpasteurized cider production, and careful manufacturing practices at cider plants can impact both safety and quality of the final product.     

Enhanced airborne polychlorinated biphenyl (PCB) concentrations and chlorination downwind of Lake Ontario

Air samples were collected simultaneously at three sites downwind of Lake Ontario and at a control site near Lake Erie from March to July of 1999. The Lake Erie site (Stockton, NY) had PCB concentrations similar to rural Integrated Atmospheric Deposition Network (IADN) sampling sites across the Great Lakes, exhibited limited seasonal variation, and approximates regional background. Samples taken along Lake Ontario's southeastern shore (Rice Creek and Sterling, NY) had elevated PCB concentrations averaging approximately 1 ng/m3 and were more chlorinated than air collected at IADN sites and at Stockton. Air samples from Potsdam (approximately 75 km inland) had similar concentrations but were less chlorinated. Clausius-Clapeyron plots revealed a strong correlation between PCB fugacity and temperature near Lake Ontario; however, the extent of chlorination of the air samples rules out volatilization from the lake as a major source. It is hypothesized that volatilization from local surfaces, enriched in higher chlorinated congeners by meteorological or geographic factors, drives both the concentration and composition of airborne PCBs along Lake Ontario's southeastern shore.     

Yam affects the antioxidative and gel‐forming properties of surimi gels

The antioxidative activities and textural properties of pollock surimi gels containing four different yams were determined to evaluate the potential of using yam as a health ingredient and an alternative source for starch in surimi‐based seafoods. Surimi gels containing 20% fresh yam showed higher α,α‐diphenyl‐β‐pricryl‐hydrazyl (DPPH) radicals scavenging activities and total phenolic contents than the gels without yam. Two tested cultivars, 70W34 and 70W35, did not show significant reductions in antioxidative activities when used in surimi gel while three other cultivars revealed species‐dependant declines in both the DPPH scavenging activities and total phenolic contents. The surimi gel containing the cultivar 70R20 showed the highest breaking forces and deformations. In general, 20% fresh yam could be used to form a yam‐containing surimi gel having similar textural properties with a potato starch containing pollock surimi gel. The dried yam powders might be used at the amount of 30% fresh yam equivalent without causing significant losses of the textural properties of pollock surimi gels. Copyright © 2005 Society of Chemical Industry     

Solid oxide fuel cells with YSZ-BNO Bi-layer electrolyte film deposited by magnetron sputtering

Bi-layer electrolyte films of Zr_0.84Y_0.16O_1.92 (YSZ)- 0.79Bi₂O₃-0.21Nb₂O₅ (BNO) were deposited by RF magnetron sputtering on NiO-SDC anode substrates. The stoichiometry of the BNO electrolyte film was found strongly dependent on the ratio of Ar and O₂ during sputtering, and the BNO film deposited at a mixture of 31 sccm Ar and 7 sccm O₂ appeared to be the closest to the target composition. When deposited at 300 °C and subsequently annealed at 700 °C, the BNO electrolyte emerged to be crack free and dense with some scattering closed pores. The XRD patterns of the film are indexed to the cubic Fm m structure of Bi₃NbO₇. The as-deposited film was well-crystalline and consisted of fine grains and random orientation microstructures. For electrolyte thicknesses of approximately 4.0 μm YSZ and 1.5 μm BNO layers, the open circuit voltage (OCV) and the maximum power density of the single cell with Ag cathode read respectively 0.94 V and 10 mW/cm² at 600 °C. These OCV values are lower than the expected theoretical value due to the high partial electronic conductivity.     

How to manipulate the electrospinning jet with controlled properties to obtain uniform fibers with the smallest diameter?—a brief discussion of solution electrospinning process

Solutions of five different polymers, namely, polystyrene (PS), polyacrylonitrile (PAN), polyhydroxybutrate (PHB), poly(D-L-lactic acid) (PLA), and Nylon6, were used to investigate their rheological properties on the electrospinnability. In order to effectively reduce the diameter of electrospun fibers, polymers with higher molecular weights (MW) were needed to develop entangled solutions at much lower concentrations and with viscosities as low as that of a pure solvent. A minimum polymer concentration 1.0–2.0 times larger than the entanglement concentration was required to prepare the bead-free fibers. Using this strategy, uniform PS fibers with the lowest ever diameter of ∼15 nm were successfully obtained using an MW of 3 × 10⁷ g/mol at a concentration of 0.1 vol.%. For a given electrospinning solution, processing variables of low flow-rate (Q) and high voltage (V) were desirable in obtaining fibers with small diameters. However, Q and V were correlated by a power law relation: V∼Q ^a, wherein the exponent a had a value of 0.1–0.4, which was relevant with the solution types. Based on the finite element analysis (FEA), a significant measure of electric field (E) occurred around the needle tip used in the experiment, and its magnitude decayed with increasing distance from the needle end (z): E∼z ⁻ⁿ. The exponent n was 1.0–2.0, depending on the needle–plate geometry, i.e., needle length, needle diameter (D _o ), plate diameter, and tip-to-plate distance (H). According to FEA results, H exhibited negligible effects on the electric field in the region of interest, i.e., z/D _o ∼1 to 10. Due to the presence of high measures of E at the needle end, approaches to render a shorter and thinner straight jet issuing from the Taylor cone to yield thinner fibers were sought because a more significant jet stretching in the “jet whipping region” can take place. A feasible route to predict the as-spun fiber diameter produced by the manipulation of the electrified jet is provided by experimentally measuring the jet diameter and numerically calculating the electric field for the jet whipping process.     

Anti-UVC Irradiation and Metal Chelation Properties of 6-Benzoyl-5,7-dihydroxy-4-phenyl-chromen-2-one: An Implications for Anti-Cataract Agent

Coumarin derivative 1, 5,7-dihydroxy-6-(3-methyl-1-butyryl)-4-phenyl-chromen- 2-one, has been reported to possess radical scavenging activity and DNA protection. We have synthesized a series of coumarins with structural modifications at positions C4, C5, C6 and C7 and evaluated them for their anti-UVC properties. Coumarin 7, 6-benzoyl-5,6-dihydroxy-4-phenyl-chromen-2-one, was found to have the most potent activity in protecting porcine γ-crystallin against UVC insults. Results of fluorescence assays indicated that compound 7 was capable of decreasing the loss of intensity while lens crystallins and DNA PUC19 were irradiated with UVC. Presence of compound 7 decreased hydroxyl radical levels determined by probe 1b and the free iron concentrations determined by Ferrozine reagent. The chelation assay showed that compound 7 was chelated to metal via 6-CO and 5-OH on the benzopyrone ring. The observed protective effects of compound 7 towards crystallins from insults of UVC and free radicals may be due to its iron-chelating activity and its peak absorption at 254 nm.