Strain Hardening and Recovery in High-Temperature Deformation by Pure-Metal Mode

By a new method using the stress relaxation test, the coefficient of strain hardening without recovery (h) and the rate of recovery without strain hardening (r) are estimated in high-temperature deformation of fcc aluminum and b c c iron, where the internal stress is confirmed to be nearly 100% of the flow stress. Both h and r are dependent on applied stress σ and temperature T in a steady-state deformation, and are represented by h=h_0(σ/E)^m exp(-Q_h/RT) and r=r_0 (σ/E)^l exp (-Q_r/RT), where h_0 and r_0 are constants, E is Young\u27s modulus and m=-0.88(-1.5), l=4.3(3.2), Q_h=-22(-76) kJ/mol, Q_r=88(132) kJ/mol for aluminum(iron). During a transient state of tensile deformation in the constant strain-rate test, h and r are nearly independent of strain. The activation energy for recovery (Q_r) is found to be appreciably smaller than that of self-diffusion, and then possible roles of pipe-diffusion and strain-enhanced diffusion in dynamic recovery are discussed

Thermal Reformation of Polystyrene Using Metal Oxide as Redox Catalyst

While plastic has been regarded as a useful and cost-effective material, there is growing global concern about its disposal. Chemical recycling presents a promising solution to this issue. This study explores the utilization of vanadium oxide as a redox catalyst to effectively decompose polystyrene into industrially useful CO. By heating polystyrene with V2O5 under an inert gas atmosphere, CO was successfully produced accompanied with CO2 as the primary by-product. Adding 5 wt% iron to V2O5 improved the selectivity of CO production without compromising gas yield. X-ray diffraction analysis indicated that V2O5 acted as an oxygen source and turned into V2O4 and V6O13 after the reaction. This process enables polymer reformation at lower temperatures than conventional methods, making it an energy-efficient chemical recycling strategy. Additionally, V2O4 and V6O13 generated during the process were easily oxidized to V2O5 through heating under atmospheric conditions. As both polymer reformation and oxidation are exothermic reactions, the proposed reaction scheme can be used as a thermally efficient chemical recycling process

Biological mechanism and clinical effect of protein-bound polysaccharide K (KRESTIN®): review of development and future perspectives

The mechanism of action of protein-bound polysaccharide K (PSK; KRESTIN®) involves the following actions: (1) recovery from immunosuppression induced by humoral factors such as transforming growth factor (TGF)-β or as a result of surgery and chemotherapy; (2) activation of antitumor immune responses including maturation of dendritic cells, correction of Th1/Th2 imbalance, and promotion of interleukin-15 production by monocytes; and (3) enhancement of the antitumor effect of chemotherapy by induction of apoptosis and inhibition of metastasis through direct actions on tumor cells. The clinical effectiveness of PSK has been demonstrated for various cancers. In patients with gastric or colorectal cancer, combined use of PSK with postoperative adjuvant chemotherapy prolongs survival, and this effect has been confirmed in multiple meta-analyses. For small-cell lung carcinoma, PSK in conjunction with chemotherapy prolongs the remission period. In addition, PSK has been shown to be effective against various other cancers, reduce the adverse effects of chemotherapy, and improve quality of life. Future studies should examine the effects of PSK under different host immune conditions and tumor properties, elucidate the mechanism of action exhibited in each situation, and identify biomarkers