The alpha-glycerolphosphate dehydrogenase and adenosinetriphosphatase activity of the peripheral blood lymphocytes in diabetics (a cytochemical determination)

Decrease in activity of alpha-GPDG and ATP-ase observed in peripheral lymphocytes of patients with diabetes mellitus correlated well severity of the disease. The lowest indices of enzymatic activity were registered in patients with grave diabetes complicated by angiopathies, foot gangrene, and purulent inflammatory processes. Compensation of carbohydrates metabolism and improvement of clinical picture were accompanied by the trend to normalization of enzymes' activity. Dynamic study of alpha-GPDG and ATP-ase in patients with diabetes mellitus allows to evaluate degree of hypoxia, comprehend the nature of compensation mechanisms and assess effectiveness of the treatment.     

Service characteristics of steel after grinding in a polymer-containing medium

Translated from Fiziko-Khimicheskaya Mekhanika Materialov, No. 5, pp. 101–103, September–October, 1989.     

Simulating organic aerosol formation during the photooxidation of toluene/NOx mixtures: comparing the equilibrium and kinetic assumption

Organic compounds contribute an appreciable mass to particulate matter and thus impact the hygroscopic and radiative properties of an aerosol distribution. Being able to predict the chemical and physical properties of aerosols based on their size and composition is critical to assessing their impact on air quality, visibility, and climate change. In this study, a comparison was performed between an equilibrium and a kinetic model for simulating organic aerosol formation during the photooxidation of toluene/NO/isopropyl nitrite mixtures. Both models used an explicit gas-phase toluene scheme (University of Leeds Master Chemical Mechanism version 3.0) and provided a prediction of individual products partitioned to the aerosol phase. After incorporating a heterogeneous wall reaction scheme regenerating NOx from HNO3 and HNO2, the gas-phase scheme was able to simulate the observed toluene decay within 5% and NO decay within 30% for all of the chamber experiments. The models reproduced the general magnitude of the aerosol yields but suggest a weaker trend dependence on aerosol mass loading. A few nonvolatile compounds were predicted to compose the majority of the aerosol-phase mass with multifunctional organic nitrates being the dominant organic aerosol functional group. The hygroscopic diameter growth factor for the organic phase was predicted to be 1.1 at a relative humidity of 79%. We conclude with a list of recommended laboratory experiments to help constrain and validate aerosol process models.     

End of the Induction Period in Ordinary Portland Cement as Examined by High-Resolution Scanning Electron Microscopy

The early stages of ordinary Portland cement (OPC) hydration were studied by cold field emission scanning electron microscopy and isothermal conduction calorimetry. Particular attention was paid to samples from the end of the induction period, where an additional peak in the tricalcium silicate hydration reaction has recently been discovered. Higher resolution images were obtained than is possible with current in situ imaging techniques, allowing for the observation of features on the 5-nm scale. The peak in the hydration at the end of the induction period was associated with both the formation of pores in the surface of the cement grains and the formation of nanoscale calcium silicate hydrate (C–S–H) structures on those surfaces. The effects of grinding of OPC and additions of tricalcium aluminate and tetracalcium aluminoferrite on the peak at the end of the induction period were also examined. The results of the study were compared with the models in the literature used to describe the causes of the induction period and its end.     

The effect of stresses approaching and exceeding the yield point on the magnetic properties of high strength pearlitic steels

The results of a study of the effects of stresses that approach and exceed the yield point on the magnetic properties of a sample of 50D pearlitic steel are reported. Unlike previous work which has only examined residual stress behaviour, measurements were made in-situ while sample remained under stress. Hysteresis loops, permeability curves and magnetostriction loops are presented and a variety of magnetic parameters analysed. The implications of this analysis for the application of non-destructive evaluation techniques such as magnetic flux leakage, magnetic Barkhausen noise and magnetoacoustic emission are discussed. Key changes in magnetic behaviour occur well before yield and this raises the possibility of developing magnetic NDE methods of predicting when a sample is approaching the yield point.     

Depression of ammonia uptake to sulfuric acid aerosols by competing uptake of ambient organic gases

The neutralization of acidic aerosols by ammonia has been studied through experiments which combine ambient air with laboratory generated sulfuric acid aerosol. Results indicated that acidic aerosol mixed with organic free air and ammonia was neutralized on a time scale<1 min, consistent with expectations. However, in the presence of ambient organic gases and ammonia, the rate of aerosol neutralization is significantly reduced. This reduction in ammonia uptake was concurrent with an increase in the amount of particle phase organics. A steady state in the NH4+/SO4(2-) in the presence of organic gases was established on time scales of 10 min to several hours, corresponding to NH3 uptake coefficients in the range of 4×10(-3)-2×10(-4). The degree to which neutralization was slowed was dependent upon the initial ammonia concentration and the organic mass added to the aerosols. These results suggest that inorganic equilibrium thermodynamic models may overestimate the rate of ammonia uptake and that ambient particles may remain acidic for longer than previously expected.     

Estimation of atmospheric emissions of six semivolatile polycyclic aromatic hydrocarbons in southern canada and the United States by use of an emissions processing system

Polycyclic aromatic hydrocarbons (PAHs) are toxic compounds that are ubiquitous in the atmospheric environment. The input for an emissions processing system that was originally configured forthe study of criteria air pollutants was updated to calculate emissions of six semivolatile PAHs. The goal of the work was to produce emissions estimates with the spatial and temporal resolution needed to serve as input to a regional air quality model for southern Canada and the U.S. Such modeling is helpful in determining reductions in PAH emissions that may be necessary to protect human and ecosystem health. The total annual emission of the six PAHs (sigma6PAH) for both countries was estimated at 18 273 Mg/year. A total of 90% of these emissions arise from U.S. sources. The top six source types account for 73% of emissions and are related to metal production, open burning, incineration, and forest fires. The emission factors used in this study were derived from published compilations. Although this approach has the advantage of quality control during the compilation process, some compilations include factors from older studies that may overestimate emissions since they do not account for recent improvements in emission control technology. When compared to estimates published in the National Emissions Inventory (NEI) for 2002, the U.S. emissions in this study are higher by a factor of 4 (16 424 vs 4102 Mg/year). The cause of this difference has been investigated, and much of it is likely due to our use of data unavailable in the 2002 NEI but inferred here on the basis of the PAH emissions literature. Augmenting the 2002 NEI with this additional information would bring its reported annual emissions to 8213 Mg/year, which is within a factor of 2 of the estimates herein. The results presented for southern Canada are the first published values for all known PAH sources in that country.