Mathematical Model of Biofiltration of VOCs: Effect of Nitrate Concentration and Backwashing

The affect of nitrate concentration and reactor backwashing on biofilter performance is evaluated using a dynamic mathematical model of the biodegradation process of volatile organic compounds in a trickle bed biofilter packed with uniform synthetic solids. Experimental observations from a bench-scale biofilter system treating ether were used to develop and validate the model. Experience acquired in biofiltration of volatile organic compounds has demonstrated that although these two factors—nitrate and backwashing—are secondary when organic packing material is used, they are essential when the packing media is synthetic. The operation of a synthetic media packed reactor requires the addition of nutrients necessary for biodegradation. Since nitrate was utilized as the nitrogen source in this system, it was included in the model as a limiting substrate (nutrient). A negative affect of excessive accumulation of biomass in the reactor on biofilter performance has also been observed in highly loaded synthetic media biofilters. This problem was solved by removing excessive biomass via full media fluidization and backwashing of the reactor. The affect of periodic backwashing was included in the model as a reduction in the biofilm thickness and a new approach to calculate the reactor specific surface area after backwashing. The unknown model parameters that correspond to nitrate limitations were estimated. The mathematical model was then used for simulation and analyses of the affect of these two factors on the biodegradation process.     

Association of protein kinase CK2 with nuclear matrix: influence of method of preparation of nuclear matrix

The cDNA for the mouse bone morphogenetic protein type II receptor (BMPR-II) was isolated using the human counterpart as a probe and its genomic structure was determined. The cDNA encodes a protein of 1,038 amino acids with a single transmembrane domain, a serine/threonine kinase domain, and a long carboxy-terminal tail. The overall amino acid sequence identity between the mouse and the human BMPR-II is 96.6%. mRNA is widely distributed in various adult tissues. The gene is encoded by 13 exons spanning over 80 kb. Two large introns (intron 1 and 3) contribute to the majority of the gene size, as in the mouse activin type II receptor gene. The intron/exon boundaries were sequenced. The results suggest that alternative splicing can yield a shorter form of BMPR-II of 530 amino acids, as reported previously. Knowledge of the structure of the BMPR-II gene is essential for the understanding of the role of bone morphogenetic proteins in the developmental and physiological processes of animals.     

An automated study of EEG: a method of detection of non-stationary points

The purpose of this paper is to present an automatic method of signal analysis. To help physicians in their diagnostics, this method is implemented on a minicomputer in order to detect non-stationary points in electroencephalograms. The signal is modelled with an autoregressive filter. The parameters of this filter are adapted at each step. Identification gives the best model in the sense of a cost function representing the mean square error of noise, which is estimated during the optimisation time-window. The cost function is expressed by a quadratic formula. This allows the use of a fast algorithm, the 'conjugate gradient method'. An original statistical test is developed to detect non-stationary points in the signal. The performance of this method is tested with artificial data to determine the sensitivity of method parameters. Detection using real data is presented.     

Differentiation between chondroma and squamous cell carcinoma: evaluation of subtraction image of MRI

The image processing procedure has become widely applied as a visual aid in imaging diagnosis. The subtraction image of MRI obtained by digitally subtracting an unenhanced image from a contrast-enhanced image, depicted a discrete distribution of the contrast agent. Subtraction images in the clinical cases were compared. The subtraction image in a case of chondroma demonstrated a relatively uniform distribution of a contrast agent, with a well delineated neoplastic lesion. The subtraction image in a case of squamous cell carcinoma, the contrast agent was distributed heterogeneously in the carcinoma and well permeated into the muscle. Different patterns of subtraction image were obtained in the clinical cases of chondroma and squamous cell carcinoma in this study. The findings suggest the potential usefulness of the subtraction image for diagnosing the degree of malignancy.     

Evaluation of the electrical resistivity of steels

Literature data on the physical properties of steels have been collected and put into a database. The resistivity of steels has been analyzed as a function of composition and microstructure. An overview over former studies is given. The steels have been investigated in two groups, ferritic steels and austenitic steels. A thermodynamic analysis with ThermoCalc has been performed. Regression analysis on the influence of composition on the resistivity was then carried out. The results for ferritic steels are: Si and Al have the highest elemental resistivity, followed by Mn, Cu, Ni, Mo, and Cr. C precipitated in cementite shows a high coefficient in the analysis when the amount of Fe bound in cementite is not considered separately. C in solution with ferrite shows no significant effect. Cr bound in cementite shows a significant effect but Mn, though present in cementite in comparable amounts, has no significant effect on the resistivity. N and C have the highest elemental resistivity in austenite, followed by the substitutional solutes Nb, Si, Ti, Cu, Ni, Mo, and Cr. The carbides NbC and TiC appear with a higher coefficient in the regression model than can be explained by phase‐mixture models providing upper and lower bounds for the resistivity of two‐phase alloys. Cr₂₃C₆ shows no significant effect. The regression results can be used to predict the resistivity of steels with known composition. The model predicts the resistivity of ferritic steels with a maximum deviation between experimental and computed value of 12 nōm and a standard deviation of 5.6 nōm. For austenitic steels, the model prediction shows a maximum deviation of 52 μōcm and a standard deviation of 20 nōm.     

Development of the process of electric steel production and methods for improving the technical-and-economic indices of electric arc furnaces

The structure of the metal losses during melting of a low-carbon semiproduct in EAF is analyzed. It is shown that a further increase in the capacity of a modern superpower EAF can degrade the technical-and-economic indices of its operation. The increase in the metal losses in melting in EAF is caused by a high oxygen flow rate and a number of other technological factors. The rational methods of increasing the technical-and-economic indices of EAF are a decrease in the metal losses in melting and processing of the semiproduct, a decrease in the primary energy consumption, and the recycling of dust and waste slags.     

The reliability and validity of a measure of self-understanding of interpersonal patterns.

Change in self-understanding of maladaptive interpersonal patterns has been an important mechanism of symptom change in theories of dynamic psychotherapy and has been specified as an important treatment outcome by psychotherapy clients. The current investigation evaluated the reliability and validity of a new self-report measure of Self-Understanding of Interpersonal Patterns (SUIP). The measure was administered to 3 clinical samples and a student sample. The measure demonstrated good internal consistency, test-retest reliability, and discriminant validity. The SUIP further demonstrated convergent validity with measures of analytical and self-improving personality traits in a clinical sample. Finally, there was significantly greater change in self-understanding in a dynamic psychotherapy as compared with a medication treatment condition, despite comparable symptom change across both treatment conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Density and surface tension of the melt of an amorphous alloy as a function of the structure of the initial sample

The structural and physicochemical properties of a melt of a new bulk amorphous alloy produced from a metal with various initial structures, such as cast, ingot, and melt quenched, have been studied. The most favorable initial structure for producing the bulk amorphous alloy forms in the metal quenched from a melt into iced water. On melting the ingot metal, an excess phase stable at a substantial superheating precipitates. The dissolution of the excess phase is accommodated by a sharp increase in the density. The melt-quenched alloy has a critical quenching temperature determined by the superposition of structure and temperature factors: the glass-forming ability of the alloy increases sharply near the critical temperature.     

Electrochemical measurement of lateral diffusion coefficients of ubiquinones and plastoquinones of various isoprenoid chain lengths incorporated in model bilayers

The long-range diffusion coefficients of isoprenoid quinones in a model of lipid bilayer were determined by a method avoiding fluorescent probe labeling of the molecules. The quinone electron carriers were incorporated in supported dimyristoylphosphatidylcholine layers at physiological molar fractions (<3 mol%). The elaborate bilayer template contained a built-in gold electrode at which the redox molecules solubilized in the bilayer were reduced or oxidized. The lateral diffusion coefficient of a natural quinone like UQ10 or PQ9 was 2.0 +/- 0.4 x 10(-8) cm2 s(-1) at 30 degrees C, two to three times smaller than the diffusion coefficient of a lipid analog in the same artificial bilayer. The lateral mobilities of the oxidized or reduced forms could be determined separately and were found to be identical in the 4-13 pH range. For a series of isoprenoid quinones, UQ2 or PQ2 to UQ10, the diffusion coefficient exhibited a marked dependence on the length of the isoprenoid chain. The data fit very well the quantitative behavior predicted by a continuum fluid model in which the isoprenoid chains are taken as rigid particles moving in the less viscous part of the bilayer and rubbing against the more viscous layers of lipid heads. The present study supports the concept of a homogeneous pool of quinone located in the less viscous region of the bilayer.     

Prolonged symptoms of brain dysfunction--adverse effect of levodopa

Symptoms of brain dysfunction occurred in a 67-year-old woman with idiopathic parkinsonism on treatment with levodopa. The adverse effect reappeared in a more severe and prolonged form when she was treated one year later with levodopa in combination with the peripheral decarboxylase inhibitor Ro-4-4602. The symptoms were associated with a markedly altered level of HMPG (a noradrenaline metabolite) in the cerebrospinal fluid.     

Investigation of regularities of ion flotation of copper with the use of sodium diethyldithiocarbamate

The regularities of the ion flotation of copper are investigated with the use of sodium diethyldithiocarbamate (DEDTK) in an apparatus designed at the Moscow Institute of Steel and Alloys. The results of investigation into the structure of the obtained precipitates of copper DEDTK are presented. The distribution over the size of air bubbles in a new flotation apparatus is analyzed. The effect that a series of factors have on the degree of removal of copper ions from model solutions is shown.     

Quantitative method of assessing the effectiveness of radiotherapy of malignant neoplasms based on computerized tomography data

Computed tomography assesses the linear coefficient of X-ray radiation decrease in the tissue and hence determines changes in its density thus allowing one to control the destruction of tumor cells and tissues during treatment. The paper proposes a procedure for determining the sizes and density of a tumor along the chosen linear direction crossing the image of a pathological focus. The whole procedure is performed by the special computer programme "Diaglmag". The equations that characterize the dynamics of using the parameters used before, during, and after treatment are presented. Baseline information on the optic image densities on a computer tomogram is obtained with a graphic scanner. The examples presented in the paper show it feasible to solve a difficult task to determine the effect of treatment. This enables a treatment regimen to be corrected in time or modified.     

Improvement of biliary excretion of ioglycamide by pretreatment with phenobarbital

The influence of a phenobarbital pretreatment on the distribution and biliary excretion of Ioglycamide was studied in 6 experiments in the anaesthetized minipig. The phenobarbital pretreatment led to a significant increase of the biliary transportmaximum and the biliary concentration of Ioglycamide. A detailed analysis suggests a phenobarbital induced stimulation of the hepatocellular excretion. The applicability of a pretreatment with phenobarbital in order to improve the opacification of the biliary system during x-ray-examinations with Ioglycamide is discussed.     

Three-dimensional structure of human protein kinase C interacting protein 1, a member of the HIT family of proteins

The three-dimensional structure of protein kinase C interacting protein 1 (PKCI-1) has been solved to high resolution by x-ray crystallography using single isomorphous replacement with anomalous scattering. The gene encoding human PKCI-1 was cloned from a cDNA library by using a partial sequence obtained from interactions identified in the yeast two-hybrid system between PKCI-1 and the regulatory domain of protein kinase C-beta. The PKCI-1 protein was expressed in Pichia pastoris as a dimer of two 13.7-kDa polypeptides. PKCI-1 is a member of the HIT family of proteins, shown by sequence identity to be conserved in a broad range of organisms including mycoplasma, plants, and humans. Despite the ubiquity of this protein sequence in nature, no distinct function has been shown for the protein product in vitro or in vivo. The PKCI-1 protomer has an alpha+beta meander fold containing a five-stranded antiparallel sheet and two helices. Two protomers come together to form a 10-stranded antiparallel sheet with extensive contacts between a helix and carboxy terminal amino acids of a protomer with the corresponding amino acids in the other protomer. PKCI-1 has been shown to interact specifically with zinc. The three-dimensional structure has been solved in the presence and absence of zinc and in two crystal forms. The structure of human PKCI-1 provides a model of this family of proteins which suggests a stable fold conserved throughout nature.     

Effects of potassium chloride and temperature on the kinetics of recombination of heavy and light chains of a human IgGl myeloma protein

The effects of KCl and temperature on the kinetics of the recombination reaction of alkylated H and L chains of a human myeloma protein were studied by means of circular dichroism (CD). The recombination rate was considerably reduced by the presence of KCl. The results of the difference spectra showed that tryptophyl residue(s) in L chains are perturbed by KCl. No changes in the CD and absorption spectra with KCl concentration were observed for H chains and recombined H2L2. The change in the rate constant with KCl concentration paralleled the changes in the CD at 235 nm and the difference in molar extinction coefficient at 293 nm. These facts suggest that the reduction of the recombination rate in the presence of KCl is due to a change in the conformation of L chains as a result of specific interaction with chloride ions or by a shift to the dimer form in the monomer-dimer equilibrium of L chains. The rate constant showed a temperature dependence with an activation energy of 17.4 kcal/mole.     

Molecular-dynamic simulations of martensitic transformation of cobalt

With a potential-energy function of Co described by the embedded-atom method (EAM), molecular-dynamics (MD) simulations were performed for a series of initial fcc configurations with different types of dislocations or preset hcp embryos. The gliding process of a Shockley dislocation on a closepacked plane has been observed, which starts from the origin of the dislocation and proceeds at a high speed of 280 m/s toward a certain direction. An atom which has been swept by the dislocation line was detected to contribute a displacement close to the Burgers vector of a Shockley dislocation. It is in this way that a new stacking sequence is produced and an hcp lamella grows in the fcc structure. A similar gliding process has been observed in the case where an intrinsic stacking fault is preexisting in the fcc structure. The transformation is, again, toward forming a local hcp region. These results prove that a special dislocation in the fcc structure can act as an embryo of the hcp, as described in many dislocation mechanisms of the martensitic transformation. The fcc → hcp phase-tranformation process of Co has been further reproduced by a simulation initiated from an fcc/hcp two-phase configuration. It yields a single hcp crystal as the final transformed product.     

Kinetics of biochemical leaching of sphalerite concentrate

The paper deals with bacterial leaching of sphalerite. The data include progress curves for leaching of the concentrate in terms of Zn, Cu, and Cd solubilization. Plots of the Zn and Cu data followed a relationship predicted by a chemical rate equation. Reaction rates for Zn and Cu were inversely related to initial particle size of the concentrate. A pulp density in excess of 2 pct caused a decrease in percent Zn leached in 31 days, presumably due to oxygen limitation. The leaching of Zn and Cu followed first order kinetics.