scholarly journals Application of chemometrics to identifying solid fuels and their origin

2013 ◽  
Vol 11 (2) ◽  
pp. 151-159 ◽  
Author(s):  
Marcin Sajdak

AbstractThe aim of this work was to implement a chemometric analysis to detect the relationships between the analysed variables in samples of solid fuels. Efforts are being made to apply chemometrics methods in environmental issues by developing methods for the rapid assessment of solid fuels and their compliance with the required emission characteristics regulations. In the present investigation, two clustering techniques—hierarchical clustering analysis (HCA) and principal components analysis (PCA)—are used to obtain the linkage between solid fuel properties and the type of sample. These analyses allowed us to detect the relationships between the studied parameters of the investigated solid fuels. Furthermore, the usefulness of chemometrics methods for identification of the origin of biofuels is shown. These methods will enable control of the degree of contamination.

2019 ◽  
Vol 12 (1) ◽  
pp. 22-28
Author(s):  
V. Ye. Mikhailov ◽  
S. P. Kolpakov ◽  
L. A. Khomenok ◽  
N. S. Shestakov

One of the most important issues for modern domestic power industry is the creation and further widespread introduction of solid propellant energy units for super-critical steam parameters with high efficiency (43–46%) and improved environmental parameters. This will significantly reduce the use of natural gas.At the same time, one of the major drawbacks of the operation of pulverized coal power units is the need to use a significant amount of fuel oil during start-up and shutdown of boilers to stabilize the burning of the coal torch in the variable boiler operating modes.In this regard, solid fuel TPPs need to be provided with fuel oil facilities, with all the associated problems to ensure the performance (heating of fuel oil in winter), reliability and safety. All of the above problems increase both the TPP capital construction costs, and the electricity generating cost.A practical solution to the above problems at present is the use of a plasma technology for coal torch ignition based on thermochemical preparation of fuel for combustion. The materials of the developments of JSC “NPO CKTI” on application of plasmatrons in boilers of thermal power plants at metallurgical complexes of the Russian Federation are also considered.Plasma ignition systems for solid fuels in boilers were developed by Russian specialists and were introduced at a number of coal-fi red power plants in the Russian Federation, Mongolia, North Korea, and Kazakhstan. Plasma ignition of solid fuels is widely used in China for almost 30% of power boilers.The introduction of plasma-energy technologies will improve the energy efficiency of domestic solid-fuel thermal power plants and can be widely implemented in the modernization of boilers.During the construction of new TPPs, the construction of fuel oil facilities can be abandoned altogether, which will reduce the capital costs of the construction of thermal power plants, reduce the construction footprint, and increase the TPP safety.


Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 764
Author(s):  
Bohu Pan ◽  
Zuowei Ji ◽  
Sugunadevi Sakkiah ◽  
Wenjing Guo ◽  
Jie Liu ◽  
...  

Severe acute respiratory syndrome coronavirus 2 (SARS−CoV−2) has caused the ongoing global COVID-19 pandemic that began in late December 2019. The rapid spread of SARS−CoV−2 is primarily due to person-to-person transmission. To understand the epidemiological traits of SARS−CoV−2 transmission, we conducted phylogenetic analysis on genome sequences from >54K SARS−CoV−2 cases obtained from two public databases. Hierarchical clustering analysis on geographic patterns in the resulting phylogenetic trees revealed a co-expansion tendency of the virus among neighboring countries with diverse sources and transmission routes for SARS−CoV−2. Pairwise sequence similarity analysis demonstrated that SARS−CoV−2 is transmitted locally and evolves during transmission. However, no significant differences were seen among SARS−CoV−2 genomes grouped by host age or sex. Here, our identified epidemiological traits provide information to better prevent transmission of SARS−CoV−2 and to facilitate the development of effective vaccines and therapeutics against the virus.


Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S69-S85
Author(s):  
Tugra Erol ◽  
Cyriel Diels ◽  
James Shippen ◽  
Dale Richards

BACKGROUND: The role of appearance of automotive seats on perceived comfort and comfort expectancy has been acknowledged in previous research but it has not been investigated in depth. OBJECTIVE: To identify the effects of the appearance of production automotive seats, based on the hypothesis that visual design differentiations are affective in creating comfort expectations. The significance of the descriptors Sporty, Luxurious and Comfortable and the associated visual design attributes was of interest. METHOD: Images from 38 automotive production seats were used in an image-based card sorting app (qCard) with a total of 24 participants. Participants were asked to categorize the different seat designs varying from 1: least, to 9: most for all three descriptors.The resulting data was analyzed using hierarchical clustering analysis. RESULTS: The results indicated that the perceived Sporty, Luxurious and Comfortable were descriptor items that significantly differentiated seats with certain design attributes. It was found that for the Sporty perception the integrated headrest design and angular shapes were key. On the other hand, the Comfort perception was characterised by seating with a separate headrest and rounded seat back/cushion shapes. CONCLUSIONS: For seat design processes, the method enables a practical way to identify elements conveying Sporty, Comfortable and Luxurious perception.


Microbiology ◽  
2009 ◽  
Vol 155 (4) ◽  
pp. 1093-1102 ◽  
Author(s):  
Roberta Provvedi ◽  
Francesca Boldrin ◽  
Francesco Falciani ◽  
Giorgio Palù ◽  
Riccardo Manganelli

In order to gain additional understanding of the physiological mechanisms used by bacteria to maintain surface homeostasis and to identify potential targets for new antibacterial drugs, we analysed the variation of the Mycobacterium tuberculosis transcriptional profile in response to inhibitory and subinhibitory concentrations of vancomycin. Our analysis identified 153 genes differentially regulated after exposing bacteria to a concentration of the drug ten times higher than the MIC, and 141 genes differentially expressed when bacteria were growing in a concentration of the drug eightfold lower than the MIC. Hierarchical clustering analysis indicated that the response to these different conditions is different, although with some overlap. This approach allowed us to identify several genes whose products could be involved in the protection from antibiotic stress targeting the envelope and help to confer the basal level of M. tuberculosis resistance to antibacterial drugs, such as Rv2623 (UspA-like), Rv0116c, PE20-PPE31, PspA and proteins related to toxin–antitoxin systems. Moreover, we also demonstrated that the alternative sigma factor σ E confers basal resistance to vancomycin, once again underlining its importance in the physiology of the mycobacterial surface stress response.


Author(s):  
M.M. Nekhamin ◽  
D.L. Bondzyk

The existing difference in the models used to describe the burning rate of solid fuel particles, and, accordingly, the difference in the constants appearing in them, determines the relevance of the formulation of the relation between the constants known from the literature and the parameters that must be set in programs for CFD modeling of heat and power processes. This, in particular, relates to modeling the combustion of solid fuels in the well-known program ANSYS FLUENT. The paper outlines a possible approach to solving this problem. Bibl. 5, Fig. 3.


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