38 research outputs found
Analyzing the Technology of Using Ash and Slag Waste from Thermal Power Plants in the Production of Building Ceramics
The work describes the problem of impounding and storing ash and slag waste at coal thermal power plants in Russia. Recovery and recycling of ash and slag waste are analyzed. Activity of radionuclides, the chemical composition and particle sizes of ash and slag waste were determined; the acidity index, the basicity and the class of material were defined. The technology for making ceramic products with the addition of ash and slag waste was proposed. The dependencies relative to the percentage of ash and slag waste and the optimal parameters for baking were established. The obtained materials were tested for physical and mechanical properties, namely for water absorption, thermal conductivity and compression strength. Based on the findings, future prospects for use of ash and slag waste were identified
Dispersion of the G-type coal dust of the Vorgashorskoe field and its influence on the thermal destruction process
Results of a comprehensive study of coal dust obtained from the G-type coal of Vorgashorskoe field are presented. The main research methods used in the work are granulometric, thermogravimetric and differential thermal analysis.
The granulometric sieving carried out confirmed the heterogeneity of the sample with size of 0-200 μm fraction for a technical analysis. It is established that fractions of less than 100 μm size account for more than 50 % of the total sample mass. The results obtained suggested that result can be different depending on the content of a fraction in the overall technical sample sent for an analysis. However, this is probably acceptable in a technical analysis of coal dust samples but not for determination of explosive and fire hazard indicators. In order to study the effect of the dispersion composition of dust on a pyrolysis process in the air (oxidizing) medium for each of the fractions of 0-200 μm and additionally for larger fractions studies were carried out using thermogravimetry and a differential thermal analysis.
The thermogravimetric analysis confirmed the hypothesis about the ambiguous behavior of coal dust during its pyrolysis depending on the dispersion composition. Two fractions showed the same behaviont during the thermal pyrolysis. The fraction of 63-94 μm is the boundary one between 0-45 and 45-63 μm and remaining fractions of larger than 94 μm in size. That fact indicates that during determination of the explosive fire hazard properties it is necessary to investigate dust samples of dispersive composition from 0 to 100 μm, i.е. a narrower fraction than in the technical analysis of samples from 0 to 200 μm. Express analysis of the obtained data of differential thermal analysis showed a difference in thermal degradation between the fractions of interest at the initial stage (250-330 °C). The results obtained allowed to draw a conclusion about the expediency of the study of coal dust of dispersive composition from 0-100 μm. It also showed the necessity of using methods considered in the paper for a detailed study of physical and chemical parameters of coal dust and an assessment of its explosive and fire hazard properties
Comparative Genomics And Functional Analysis Of Rhamnose Catabolic Pathways And Regulons In Bacteria
L-rhamnose (Rha) is a deoxy-hexose sugar commonly found in nature. L-Rha catabolic pathways were previously characterized in various bacteria including Escherichia coli. Nevertheless, homology searches failed to recognize all the genes for the complete L Rha utilization pathways in diverse microbial species involved in biomass decomposition. Moreover, the regulatory mechanisms of L-Rha catabolism have remained unclear in most species. A comparative genomics approach was used to reconstruct the L-Rha catabolic pathways and transcriptional regulons in the phyla Actinobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Proteobacteria, and Thermotogae. The reconstructed pathways include multiple novel enzymes and transporters involved in the utilization of L-Rha and L-Rha-containing polymers. Large-scale regulon inference using bioinformatics revealed remarkable variations in transcriptional regulators for L-Rha utilization genes among bacteria. A novel bifunctional enzyme, L-rhamnulose-phosphate aldolase (RhaE) fused to L-lactaldehyde dehydrogenase (RhaW), which is not homologous to previously characterized L-Rha catabolic enzymes, was identified in diverse bacteria including Chloroflexi, Bacilli, and Alphaproteobacteria. By using in vitro biochemical assays we validated both enzymatic activities of the purified recombinant RhaEW proteins from Chloroflexus aurantiacus and Bacillus subtilis. Another novel enzyme of the L-Rha catabolism, L-lactaldehyde reductase (RhaZ), was identified in Gammaproteobacteria and experimentally validated by in vitro enzymatic assays using the recombinant protein from Salmonella typhimurium. C. aurantiacus induced transcription of the predicted L-Rha utilization genes when L-Rha was present in the growth medium and consumed L-Rha from the medium. This study provided comprehensive insights to L-Rha catabolism and its regulation in diverse Bacteria
Premalignant changes in the bronchial epithelium are prognostic factors of distant metastasis in non-small cell lung cancer patients
Background: The study assessed the possibility of dividing patients into groups based on the assessment of morphological changes in the epithelium of small-caliber bronchi located near the primary tumor in order to predict high and low risks of distant metastasis of non-small cell lung cancer. Methods: In 171 patients with non-small cell lung cancer (T1-4N0-3M0) in small-caliber bronchi taken at a distance of 3–5 cm from the tumor, various variants of morphological changes in the bronchial epithelium (basal cell hyperplasia (BCH), squamous cell metaplasia (SM), and dysplasia (D)) were assessed. Long-term results of treatment, namely, distant metastasis, were assessed after 2 and 5 years. Results: During the follow-up period, distant metastases were found in 35.1% (60/171) of patients. Most often, they were observed in patients of the high-risk group: BCH+SM−D−(51.6%, 40/95) and BCH−SM+D+ (54.4%, 6/11). Less often, distant metastases were observed in low-risk group patients: BCH+SM+D− (6.7%, 3/45) and BCH−SM−D−(10.0%, 2/20). Tumor size, grade, and stage were significant predictors of metastasis only in the high-risk group. The 5-year metastasis-free survival was better in the low-risk group of distant metastases. Conclusions: Isolated BCH or dysplasia in small bronchi distant from foci of tumor isassociated with a high-risk distant metastasis and less 5-year metastasis-free survival
Protonation and Photocatalytic Activity of the Rb 2
The Rb2La2Ti3O10 layered oxide was synthesized by the solid-state method. Three phases with different protonation degrees and intercalated water contents were obtained from the initial compound by the treatment with distilled water and hydrochloric acid. The obtained samples were characterized by powder X-ray diffraction, SEM, X-ray microanalysis, BET, DRS, and TG. It was found that the complete ion exchange of Rb+ for H+ in the layered oxide Rb2La2Ti3O10 proceeds through the formation of two metastable intermediate phases with average protonation degrees of 0.5 and 0.75, which successively transform from one to another. Each of these phase transformations is accompanied not only by the contraction of the interlayer distance but also by the displacement of adjacent perovskite layers by 1/2 of the cell parameter which results in the change in the space group. The photocatalytic activity of obtained samples decreases with the increase in the protonation degree, which correlates with the decrease in the intercalated water content
Cavity-QED simulation of a quantum metamaterial with tunable disorder
We explore experimentally a quantum metamaterial based on a superconducting chip with 25 frequency-tunable transmon qubits coupled to a common coplanar resonator. The collective bright and dark modes are probed via the microwave response, i.e., by measuring the transmission amplitude of an external microwave signal. All qubits have individual control and readout lines. Their frequency tunability allows to change the number N of resonantly coupled qubits and also to introduce a disorder in their excitation frequencies with preassigned distributions. While increasing N, we demonstrate the expected N scaling law for the energy gap (Rabi splitting) between bright modes around the cavity frequency. By introducing a controllable disorder and averaging the transmission amplitude over a large number of realizations, we demonstrate a decay of mesoscopic fluctuations which mimics an approach towards the thermodynamic limit. The collective bright states survive in the presence of disorder when the strength of individual qubit coupling to the cavity dominates over the disorder strength
Пульмональный Лангергансоклеточный гистиоцитоз легких: клиническое наблюдение в стадии раннего поражения
Histocytosis X is a rare disease of unknown etiology involving the reticuloendothelial system. We present a case of a 32 year-old man diagnosed with Pulmonary Histocytisis X. The CT image of the lungs showed disseminated disease with the formation of cyst-like cavities, which were histologically verified using lung biopsy. Лангергансоклеточный гистиоцитоз (гистиоцитоз Х) – заболевание ретикулогистиоцитарной системы неизвестной этиологии. Представлен клинический случай данной патологии у мужчины 32 лет с характерной компьютерно-томографической картиной легких в виде диссеминированного процесса с формированием кистозных полостей, который верифицирован морфологически с помощью биопсии легких.
Genetic diversity in the Orenburg goat breed revealed by single-nucleotide polymorphism (SNP) analysis: Initial steps in saving a threatened population
Background/Objectives: For genomic selection to enhance the efficiency of broiler production, finding SNPs and candidate genes that define the manifestation of main selected traits is essential. We conducted a genome-wide association study (GWAS) for growth and meat productivity traits of roosters from a chicken F2 resource population (n = 152). Methods: The population was obtained by crossing two breeds with contrasting phenotypes for performance indicators, i.e., Russian White (slow-growing) and Cornish White (fast-growing). The birds were genotyped using the Illumina Chicken 60K SNP iSelect BeadChip. After LD filtering of the data, 54,188 SNPs were employed for the GWAS analysis that allowed us to reveal significant specific associations for phenotypic traits of interest and economic importance. Results: At the threshold value of p < 9.2 × 10−7, 83 SNPs associated with body weight at the age of 28, 42, and 63 days were identified, as well as 171 SNPs associated with meat qualities (average daily gain, slaughter yield, and dressed carcass weight and its components). Moreover, 34 SNPs were associated with a group of three or more traits, including 15 SNPs significant for a group of growth traits and 5 SNPs for a group of meat productivity indicators. Relevant to these detected SNPs, nine prioritized candidate genes associated with the studied traits were revealed, including WNT2, DEPTOR, PPA2, UNC80, DDX51, PAPPA, SSC4D, PTPRU, and TLK2. Conclusions: The found SNPs and candidate genes can serve as genetic markers for growth and meat performance characteristics in chicken breeding in order to achieve genetic improvement in broiler production