Effect of tensile strain rate on the mechanical properties of constrained-uniaxially and simultaneous-biaxially drawn poly(ethylene terephthalate) sheets

The dependency of the mechanical properties (Young's modulus, yield strength, breaking strain, and breaking energy) of preoriented poly(ethylene terephthalate) (PET) sheets on the tensile deformation speeds was examined and discussed in relation to changes of density and birefringence. The procedures for preorientation were constrained-uniaxially (CU) and simultaneous-biaxially (SB) drawings at 65°C. The performance characteristics of the present tensile testing at room temperature were obtained over a wide range of extension rates (1.7 × 10^?4?13.1 m/s = 0.29–2.3 × 10⁴%/s) without changing the mode of deformation and the shape of the test pieces. The CU drawn PET is strain-rate-independent and mechanically superior in structure in the preextended direction with draw ratio λ > 2.5. In the SB drawn PET such a structure comes into existence at λ > 3, which has, furthermore, no dependency on draw direction (mechanically isotropic). The draw ratio of the latter case corresponded to the birefringence (?Δn/d) of about 5 × 10^?2. These results imply a possibility of producing the strain rate (from low to impact speeds) independent, anisotropy-free, and mechanically superior molded products of PET if adequate extrusion or blow molding methods which induce multiaxial orientation with ?Δn/d > 5 × 10^?2 are developed.     

Proposal for quantum-dot electroabsorption modulator

Quantum-dot, electroabsorption materials are proposed to obtain low internal loss, large absorption modulation, and negative alpha parameters (blue chirped pulses). These characteristics come from the discrete state absorption associated with three dimensional confinement in quantum dots compared to the band absorption of quantum well, quantum wire, and bulk materials. In addition, type II quantum-dot structures are also proposed to obtain the same optical modulation characteristics with the potential for greater immunity to saturation effects.     

Influences of atomic hydrogen on porous low-k dielectric for 45-nm node

Atomic hydrogen generated by a heated tungsten catalyzer has been investigated in terms of the damage-less ash and restoration of damaged low-k dielectric. No difference of damaged thickness of low-k dielectric between before and after the ash by HF dip using patterned porous methyl silsesquioxane (MSQ) film was found. Moreover atomic hydrogen exposure slightly reduced capacitance of the micro-structured capacitor with the Cu wire and the CVD porous low-k dielectric.     

Adjunct cultures: recent developments and potential significance to the cheese industry

Several previous reviews have described different ways to enhance the flavor and texture of cheese, including use of live cells and nonviable attenuated cells as adjunct cultures. However, comparisons between viable and nonviable cultures were never discussed in these reviews. In addition, recent publications on adjunct cultures have not been covered in previous reviews. This article will survey the more recent work on adjunct cultures--with particular attention to whether the adjuncts contained viable or nonviable cells--and propose areas where additional research is needed.     

Pore development in carbonized hemoglobin by concurrently generated MgO template for activity enhancement as fuel cell cathode catalyst

Various carbon materials with a characteristic morphology and pore structure have been produced using template methods in which a carbon-template composite is once formed and the characteristic features derived from the template are generated after the template removal. In this study, hemoglobin, which is a natural compound that could be abundantly and inexpensively obtained, was used as the carbon material source to produce a carbonaceous noble-metal-free fuel cell cathode catalyst. Magnesium oxide was used as the template concurrently generated with the hemoglobin carbonization from magnesium acetate mixed with hemoglobin as the starting material mixture to enable pore development for improving the activity of the carbonized hemoglobin for the cathodic oxygen reduction. After removal of the MgO template, the substantially developed pores were generated in the carbonized hemoglobin with an amorphous structure observed by total-electron-yield X-ray absorption. The extended X-ray absorption fine structure at the Fe-K edge indicated that Fe was coordinated with four nitrogen atoms (Fe-N(4) moiety) in the carbonized hemoglobin. The oxygen reduction activity of the carbonized hemoglobin evaluated using rotating disk electrodes was dependent on the pore structure. The highly developed pores led to an improved activity.     

Toward Personalized Nanomedicine: The Critical Evaluation of Micro and Nanodevices for Cancer Biomarker Analysis in Liquid Biopsy

Liquid biopsy for the analysis of circulating cancer biomarkers (CBs) is a major advancement toward the early detection of cancer. In comparison to tissue biopsy techniques, liquid biopsy is relatively painless, offering multiple sampling opportunities across easily accessible bodily fluids such as blood, urine, and saliva. Liquid biopsy is also relatively inexpensive and simple, avoiding the requirement for specialized laboratory equipment or trained medical staff. Major advances in the field of liquid biopsy are attributed largely to developments in nanotechnology and microfabrication that enables the creation of highly precise chip-based platforms. These devices can overcome detection limitations of an individual biomarker by detecting multiple markers simultaneously on the same chip, or by featuring integrated and combined target separation techniques. In this review, the major advances in the field of portable and semi-portable micro, nano, and multiplexed platforms for CB detection for the early diagnosis of cancer are highlighted. A comparative discussion is also provided, noting merits and drawbacks of the platforms, especially in terms of portability. Finally, key challenges toward device portability and possible solutions, as well as discussing the future direction of the field are highlighted.