Phase imaging with the scanning acoustic microscope

A new mode of operation for the acoustic microscope is described whereby the phase shift through the object is displayed in the form of an image. Experimental results are presented at an acoustic frequency of 1000 MHz. It is hoped that the `phase-only? images obtained with this technique will complement the conventional amplitude transmission images by providing additional information about the acoustic properties of the object.     

A novel synthetic route for high-index faceted iron oxide concave nanocubes with high T<Subscript>2</Subscript> relaxivity for <Emphasis Type="Italic">in vivo</Emphasis> MRI applications

Iron oxide nanoparticles (IONPs) with high-index facets have shown great potential as high performance T₂ contrast agents for MRI. Previous synthetic approaches focused mainly on ion-directed or oxidative etching methods. Herein, we report a new synthetic route for preparing high-index faceted iron oxide concave nanocubes using a bulky coordinating solvent. Through the systematic replacement of a non-coordinating solvent, 1-octadecene, with trioctylamine, the solvent interaction with the nanoparticle surface is modified, thereby, promoting the growth evolution of the IONPs from spherical to concave cubic morphology. The presence of the bulky trioctylamine solvent results in particle size increase and the formation of nanoparticles with enhanced shape anisotropy. A well-defined concave nanocube structure was evident from the early stages of particle growth, further confirming the important role of bulky coordinating solvents in nanoparticle structural development. The unique concave nanocube morphology has a direct influence on the magnetic properties of the IONPs, ultimately leading to an ultra-high T₂ relaxivity (862.2?mM^?1?s^?1), and a 2-fold enhancement in T₂^*-weighted in vivo MRI contrast compared to spherical IONP analogs.

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Back-extraction Of Pu4 From 20% Tributyl Phosphate - 20% Mixed Trialkyl Phosphine Oxides/kerosene In The Presence Of

Back-extraction of Pu^4 +  from a mixture of 20% tributyl phosphate (TBP) and 20% mixed trialkyl phosphine oxides (TRPO) in kerosene in the presence of UO²⁺₂was studied. The back-extractants investigated may be divided into three groups: carboxylic acids and salts, amino polycarboxylates, and phosphonic acid. The distribution coefficients of both Pu^4 +  and UO²⁺₂using a number of different back-extractants were measured and compared. The results obtained suggest that the only practical back-extractants are carboxylic acids. Among the carboxylic acids tested, oxalic acid is suitable when the UO²⁺₂ concentration in the organic phase is less than 2 g/L. For UO²⁺₂concentrations between 2 and 10 g/L, oxalic acid-nitric acid mixtures may be used. For UO²⁺₂concentrations greater than 10 g/L, the only practical back-extractant is glycolic acid. The results obtained here may be used to further develop a new process for separation of Pu^4 +  and UO²⁺₂ from TBP-TRPO/kerosene mixture.     

Preparation of liquid-core hydrogel beads using antioxidant-rich Syzygium caryophyllatum fruit pulp as a healthy snack

Reverse spherification is a common technique used in molecular gastronomy to produce innovative products with an improved texture by shaping a liquid into an edible semisolid sphere that gives a burst in the mouth sensation. In this study, liquid-core hydrogel beads (LHBs) were prepared using Syzygium caryophyllatum fruit pulp adapting reverse-phase molecular gastronomy as a minimal processing technique to promote it as a healthy snack. Three types of hydrogel beads were formulated while considering the stability of LHBs. Long-term hardening of fruit juice in sodium alginate solution and the addition of plasticizer was used as two methods to increase the textural stability of LHBs. Results revealed that the addition of the plasticizer imparted to improve all the physical and textural properties of beads; however, it affects the transparency of the hydrogel membrane as well. Although the plasticizer increased the textural stability of LHBs, prolong inlaying them in it (the plasticizer) contribute to occur adverse consequences on the quality. Hence, the inlaying of LHBs in glycerol for 2 min was selected as the best treatment (HBP1). Since HBP1 had a low hardness (125.00 g) and high resilience (0.21), it imparted a chewing gum-like texture to LHBs. Hence, it (HBP1) can be used as a healthy snack. While HBP1 was capable of retained 90% antioxidant activity of fresh fruit of S. caryophyllatum, total polyphenolic content, 2,2-diphenyl-2-picryl-hydrazyl scavenging activity %, and ferric reducing antioxidant power value of this formulation were 59.50 GAE/g of dried LHBs, 68.96% and 139.69 TE/g of dried LHBs, respectively.     

Effects of gender on work-related attitudes: study of lean implemented textile and apparel manufacturing firms

Work related attitudes, such as perceived organizational support, turnover intention, job satisfaction, affective commitment, and job involvement, have received much attention by academics and practitioners for a number of reasons. Previous research indicates that such attitudes have important organizational consequences. However, little attention has been given to investigate the differential effect of gender on the work-related attitudes, in particular shop-floor employees of the textile and apparel manufacturing sector. In this study, using a sample of 616 employees in the textile and apparel manufacturing industry, the effects of gender on work-related attitudes was investigated. The results suggested that women perceived more organizational support, job satisfaction, affective commitment, and job involvement than men. However, despite the above positive work attitudes, women perceive higher turnover intention than men. This contradicts the general findings of organizational behavior theory that higher work attitudes lead to lower turnover intention.     

Smart PTFE Membrane with Hydrophilicity and pH Sensitivity through MAA-grafting

In this article, the microporous membrane of stretched polytetrafluoroethylene (S-PTFE) film was modified through grafting hydrophilic methacrylic acid (MAA). SEM image showed that the grafted poly(methacrylic acid) (PMAA) covered uniquely on regular nanofiber-frame in S-PTFE. The surface contact angle of the membrane minishes rapidly with the increase of grafting ratio and falls down to the minimum point at 57° when the grafting ratio is about 4.7%. The water flux of the PTFE-g-PMAA membrane is very sensitive to pH values. At lower pH, the larger water flux was obtained. This contribution indicate the possibility of adjustable water flux by pH.     

Effect of nozzle size on texturing performance: comparison between air-jet and steam-jet texturing

The objectives of this research work were to investigate the use of steam in order to replace air in the production of spun-like textured yarn and to investigate the optimum nozzle size for steam-jet textured yarn for the application of sewing thread. An existing air-jet texturing machine was modified to supply either air or steam to the texturing nozzle. Using four texturing nozzles, both air-jet and steam-jet textured yarns were manufactured. The effect of nozzle size on process and yarn parameters has been studied and compared with air-jet textured yarns. The results show that spun-like textured yarn manufactured using steam has lower loop instability and higher tensile properties than air at comparable fluid pressures. SEM image analysis shows that the entangled structure of the steam-jet textured yarns is similar to air-jet textured yarns. Further, sewability results show that steam-jet textured yarns are suitable to manufacture sewing threads.