Structural and Textural States of Steel 06G2MB Strips After Controlled Thermomechanical Treatment

Metal Science and Heat Treatment - Orientation microscopy (EBSD) is used to study structural and textural states through the thickness of pipe steel strips after a controlled thermomechanical...     

Irreversible deformation and the superplasticity of a TN-1 alloy during thermal cycling through the martensitic transformations ranges under loading

The influence of the thermal cycling conditions on the thermal-cycling creep of a TN-1 alloy and the related irreversible deformations is studied. The conditions under which an anomalous increase in the irreversible deformations begins are determined. The structural mechanism of the irreversible deformations of an equiatomic alloy is shown to be analogous to the structural mechanism of metal creep at high temperatures: it predominantly has a dislocation character. It is proposed to use the effect of anomalous increase in the deformation of materials with reversible martensitic transformations for forming parts made of these materials at low temperatures.     

Treatment of a colored groundwater by ozone-biofiltration: pilot studies and modeling interpretation

Pilot studies investigated the fates of color, dissolved organic carbon (DOC), and biodegradable organic matter (BOM) by the tandem of ozone plus biofiltration for treating a source water having significant color (50 cu) and DOC (3.2 mg/l). Transferred ozone doses were from 1.0 to 1.8 g O3/g C. Rapid biofilters used sand, anthracite, or granular activated carbon as media with empty-bed contact time (EBCT) up to 9 min. The pilot studies demonstrated that ozonation plus biofiltration removed most color and substantial DOC, and increasing the transferred ozone dose enhanced the removals. For the highest ozone dose, removals were as high as 90% for color and 38% for DOC. While most of the color removal took place during ozonation, most DOC removal occurred in the biofilters, particularly when the ozone dose was high. Compared to sand and anthracite biofilters, the GAC biofilter gave the best performance for color and DOC removal, but some of this enhanced performance was caused by adsorption, since the GAC was virgin at the beginning of the pilot studies. Backwashing events had no noticeable impact of the performance of the biofilters. The Transient-State, Multiple-Species Biofilm Model (TSMSBM) was used to interpret the experimental results. Model simulations show that soluble microbial products, which comprised a significant part of the effluent BOM, offset the removal of original BOM, a factor that kept the removal of DOC relatively constant over the range of EBCTs of 3.5-9 min. Although improved biofilm retention, represented by a small detachment rate, allowed more total biofilm accumulation and greater removal of original BOM, it also caused more release of soluble microbial products and the build up of inert biomass in the biofilm. Backwashing had little impact on biofilter performance, because it did not remove more than 25% of the biofilm under any condition simulated.     

Finding Forces Required to Change Air Hammer Path in Soil

The authors solve the problem on forces required to change drilling path of air hammers in soil. Soil mass is assumed a rigid–plastic medium with the Mohr–Coulomb yield, and the air hammer deviator is considered as a nondeformable body. The problem is solved in two stages: introduction of the deviator in soil and travel of the air hammer in soil with the rear deviated at a certain angle. The loads applied to the rear, the forces and the moment required to changing the path of an air hammer in soil are calculated.     

Aluminum (Iron) Phosphate Glasses Containing Rare Earth and Transuranium Elements: Phase Composition,Oxidation State of Np and Pu,and Hydrolytic Durability

Samples of aluminum (iron) phosphate glasses containing weighable amounts of rare earth and transuranium elements were synthesized. The quenched glasses obtained are X-ray amorphous, and in the course of annealing they undergo partial crystallization with segregation of a poorly soluble phase of monazite structure. However, the hydrolytic durability of the glasses remains on the level meeting the requirements to immobilized high-level waste (no more than 10^–7 g cm^–2 day^–1). Plutonium in the surface layer of the glass samples occurs in oxidation state IV, and neptunium, mainly in oxidation states IV and V.     

Portable Microwave Reflection Coefficient Meter of Coatings

Journal of Communications Technology and Electronics - In this study, we propose a new design of a portable meter of reflection coefficients of radar absorbing coatings. An experimental comparison...     

Distribution of luminescence centers in the bulk of undoped,Fe-doped,and Cr-doped CVD ZnSe polycrystals studied by two-photon confocal microscopy

Edge and defective-impurity luminescence in polycrystalline CVD ZnSe has been studied in the range 0.46–0.73 μm by two-photon confocal microscopy. We have obtained luminescence intensity distribution maps for undoped, iron-doped, and chromium-doped ZnSe samples at depths of up to 1 mm with a spatial resolution of a few microns. It has been shown that crystal regions with low dopant concentrations contain centers that luminesce in the ranges 520–580 and >670 nm. The parts of the crystals with high iron and chromium concentrations contain centers that suppress the edge and defective-impurity (520–580 nm) luminescence. We discuss the nature of these centers and demonstrate the possibility of assessing the luminescence characteristics of grain boundaries in CVD ZnSe.     

Determination of length of horizontal pneumatic transport line in drilling machine for mud removal by negative pressure

Under discussion is soil transport by negative pressure generated in horizontal rotating pipeline. Based on the relations between soil batch velocity, soil batch mass and diameter of the pipeline, the authors have developed procedure to determine the limit pipeline length. The rotary velocity of the pipeline is related with its diameter. Reliability of the proposed procedure results is experimentally proved.