Effect of blend ratio and elongation flow on the morphology and properties of epoxy resin‐poly(trimethylene terephthalate) blends

The effect of processing conditions on the morphology of polymer blends is a topic of tremendous practical interest especially for thermoset–thermoplastic blends. The effect of blend ratio and the nature of the flow field (shear flow vs. elongation flow) on the morphology is followed here using blends of diglycidyl ether of bisphenol A (DGEBA)‐poly(trimethylene terephthalate) (PTT). Morphology of the blends prepared by the conventional melt mixing technique is compared with that prepared by using an elongation mixer (RMX device invented by Muller et al.). The blends prepared by the elongation mixer showed excellent transparency and higher storage modulus at room temperature than the conventional mixer. In the case of samples prepared by the RMX device T_g of the epoxy phase has been shifted to lower temperatures indicating a molecular level mixing between PTT and DGEBA. However the conventional melt mixed samples showed only a marginal shift in T_g to low temperatures indicating that the system is not as miscible as that prepared by the RMX device. The use of RMX device for thermoset–thermoplastic blends is novel and no work has been reported in this relation. The properties of the blends were strongly affected by the composition and the crystallization of the semicrystalline PTT phase. POLYM. ENG. SCI., 55:1679–1688, 2015. © 2014 Society of Plastics Engineers     

An adsorptive transfer technique coupled with brdicka reaction to reveal the importance of metallothionein in chemotherapy with platinum based cytostatics

The drugs based on platinum metals represent one of the oldest, but also one of the most effective groups of chemotherapeutic agents. Thanks to many clinical studies it is known that resistance of tumor cells to drugs is a frequent cause of chemotherapy failure. With regard to platinum based drugs, multidrug resistance can also be connected with increased expression of low-molecular weight protein metallothionein (MT). This study aimed at investigating the interactions of MT with cisplatin or carboplatin, using the adsorptive transfer technique coupled with differential pulse voltammetry Brdicka reaction (AdTS DPV Brdicka reaction), and a comparison of in vitro results with results obtained in vivo. The results obtained from the in vitro study show a strong affinity between platinum based drugs and MT. Further, we analyzed extracts of neuroblastoma cell lines treated with cisplatin or carboplatin. It is clear that neuroblastoma UKF-NB-4 cisplatin-resistant and cisplatin-sensitive cell lines unlikely respond to the presence of the platinum-based cytostatics cisplatin and carboplatin. Finally, we determined the level of MT in samples from rabbits treated with carboplatin and patients with retinoblastoma treated with the same drug.     

Simulation Based Investigation of Triple Heterojunction TFET (THJ-TFET) for Low Power Applications

Silicon - We designed a new model tunnel field-effect transistor (TFET) based on Triple Heterojunction Tunnel Field Effect Transistor (THJ-TFET) is investigated and designed in this paper. This...     

Potassium Lactate and Fresh-Pork-Sausage Formulation Effects on Shelf Life in Lighted and Unlighted Display

ABSTRACT:  The objective was to examine the effects of potassium lactate (KL) and raw-meat blend on the shelf-life of fresh-pork-sausage patties in lighted and unlighted display. Four fresh-pork-sausage blends (70% prerigor meat, 30% fresh-pork trim; 80%/20%; 90%/10%; and 100%/0%) were formulated ( n = 3) with 0% and 3% KL, and patties were displayed for 10 d at 4 °C in lighted display or for 7 d in unlighted display followed by 3 d in lighted display. Patties with KL had lower aerobic plate counts (APC), more stable color (greater a* and chroma, less visual discoloration), and less lipid oxidation ( P < 0.05) during display than did patties without KL. Patties in the light for 10 d were more discolored and had more lipid oxidation ( P < 0.05) than those in the dark for 7 d followed by the light for 3 d. Patties with KL in the light for 10 d had similar color ( P > 0.05) to patties without KL that were in the dark for the first 7 d. Adding KL resulted in similar color stability ( P > 0.05) among patties made from 80, 90, and 100% prerigor meat and greater color stability ( P < 0.05) than similarly formulated patties without KL. By using 3% KL, fresh-pork-sausage patty color stability was maximized, APC and lipid oxidation were minimized, and formulation costs can be decreased by using less-expensive fresh-pork trim for up to 20% of the blend. Adding KL also minimized the effects of display lighting on myoglobin and lipid oxidation.     

Reconstructing Sixteenth-Century Istanbul: The Use of Digital Modelling as an Heuristic Tool in Architectural History Research

In this paper, we draw upon digital 2D and 3D modelling techniques to analyse two sixteenth-century visual records of the city of Istanbul at that time: the Prospect of Constantinople by Melchior Lorichs (or Lorck) held at the University of Leiden, and the view of the Hippodrome and Hagia Sophia in the Freshfield Folio held at Trinity College, Cambridge. We propose that, through digitally-based analysis of these sources that matches aspect ratios and viewpoints, it is possible to extract new evidence for the topography and structures of the city during this period.     

Boiling characteristics of ternary mixtures inside enhanced surface tubing

Two phase flow characteristics such as coefficient of heat transfer and pressure drop observed during boiling of ternary azeotropic refrigerant mixtures R-404A (R-125/RR--134a/R-143a:44/4/52), R-407B (R-32/R-125/R-134a: 10/70/20), R-407C (R-32/R-125/R-134a:23/25/52) and R-408A (R-22/R-125/R-143a:46/7/47) are presented and analyzed in this paper.Experiments showed that for Reynolds numbers higher than 4.5 E04, R-408A and R-404A appear to have greater heat transfer rates than the other blends under investigation. Furthermore, it is quite evident from this data that at higher Reynolds number R-404A and R-408A have the highest pressure drop while R-407 experiences the lowest pressure drop among the refrigerants under investigation.     

Oxidation of Silicon Carbide Fibers During Static Fatigue in Air at Intermediate Temperatures

The static fatigue of SiC-based fiber bundles and single fibers has been examined in previous papers, with emphasis placed on the analysis of the stress–rupture time data, and on the modelling of delayed failure from slow crack growth. The present paper investigates the oxidation of the fibers during static fatigue, at temperatures in the intermediate temperature range (500°–800°C). Two oxidation-induced phenomena have been evidenced: the formation of a thin silica film at the surface of fibers and the delayed failure of fiber bundles and single filaments. The stress–rupture time data are interpreted with respect to the chemical and structural characteristics of fibers, and to the oxide film growth rate. The structural analysis of the fibers was carried out using scanning electron microscopy and Auger electron spectroscopy. Delayed failure was found to result from slow crack propagation from surface defects, as a result of the consumption of the free carbon at grain boundaries and the local stresses induced by the SiC→SiO₂ transformation at the crack tip. The respective contributions of these phenomena to static fatigue are discussed.     

Inhibition of phagolysosomal biogenesis by the Leishmania lipophosphoglycan

Whereas amastigotes of the protozoan parasite Leishmania proliferate inside acidic phagolysosomal vacuoles of the macrophage, vacuoles induced by Leishmania donovani promastigotes during initiation of infection are poorly characterized. Here, evidence is presented that interaction of these parasitophorous vacuoles with endocytic organelles is very limited. In contrast, vacuoles formed around L. donovani mutants lacking the cell surface lipophosphoglycan (LPG) fuse extensively with endosomes and lysosomes. The role of LPG repeating units in the inhibition of phagosome-endosome fusion was demonstrated using two different approaches. First, genetic complementation of the LPG-defective C3PO mutant restored its ability to inhibit phagosome-endosome fusion to a degree similar to that of wild-type promastigotes. Second, opsonization of C3PO mutant cells with purified L. donovani LPG also conferred to this mutant the ability to inhibit phagosome-endosome fusion. Inasmuch as LPG is essential for infecting macrophages, these results suggest that inhibition of phagolysosomal biogenesis by LPG repeating units represents an intramacrophage survival strategy used by promastigotes to establish infection.