Selection for novel, acid-tolerant Desulfovibrio spp. from a closed Transbaikal mine site in a temporal pH- gradient bioreactor

Almost all the known isolates of acidophilic or acid-tolerant sulphate-reducing bacteria (SRB) belong to the spore-forming genus Desulfosporosinus in the Firmicutes. The objective of this study was to isolate acidophilic/acid-tolerant members of the genus Desulfovibrio belonging to deltaproteobacterial SRB. The sample material originated from microbial mat biomass submerged in mine water and was enriched for sulphate reducers by cultivation in anaerobic medium with lactate as an electron donor. A stirred tank bioreactor with the same medium composition was inoculated with the sulphidogenic enrichment. The bioreactor was operated with a temporal pH gradient, changing daily, from an initial pH of 7.3 to a final pH of 3.7. Among the bacteria in the bioreactor culture, Desulfovibrio was the only SRB group retrieved from the bioreactor consortium as observed by 16S rRNA-targeted denaturing gradient gel electrophoresis. Moderately acidophilic/acid-tolerant isolates belonged to Desulfovibrio aerotolerans - Desulfovibrio carbinophilus - Desulfovibrio magneticus and Desulfovibrio idahonensis - Desulfovibrio mexicanus clades within the genus Desulfovibrio. A moderately acidophilic strain, Desulfovibrio sp. VK (pH optimum 5.7) and acid-tolerant Desulfovibrio sp. ED (pH optimum 6.6) dominated in the bioreactor consortium at different time points and were isolated in pure cultur

Study of Perceived Accessibility in Daily Travel within the Metropolis

The growth of metropolises and the number of vehicles cruising within their boundaries creates a permanent problem of dissatisfaction with transport accessibility. This study aims to identify the difference between perceived (PA) and objective (OA) transport accessibility. For its implementation, it was necessary: to explore PA between different residential areas and travel modes, reveal the influence of the travel regime on the PA, compare the impact of social-demographic factors on the individuals' PA. The research methodology is based on a large cross-sectional study with 2,275 respondents. A quota sample was used for 12 administrative districts of the Moscow metropolis. The data was processed by IBM SPSS Statistics 20 statistical program to obtain descriptive statistics indicators. Correlation analysis of the respondent's answers to the four items for PA assessment was performed to assess the relationship between the results of the solutions. Next, a synthetic index of PA was calculated and analyzed differences using the integral index PA. The relationship significance was assessed using F-criterion-based one-way ANOVA. The novelty of our study is as follows: it contributes to previous research on the possibility of measuring perceived affordability in metropolitan areas and benchmarking OA and RA. Doi: 10.28991/esj-2021-01316 Full Text: PD

A New Combined Model for Assessing the Perceived Accessibility of Public Transport by Consumers in the Megapolis

This research aims to create and test a new combined model to identify causal relationships between the perceived accessibility of the non-rail urban ground public transport (UGPT) route network and consumer experience in megacities. The methods used in the research are based on a combination of two models for assessing the perceived accessibility of UGPT passengers and the frequency of UGPT use. An online survey of 1,500 megapolis residents based on the quota sample was organized. Contingency tables were used to test the hypothesis, with the result reliability at a significance level of 5%, which was checked using the chi-square test. The impact of consumer experience on passengers’ perceived accessibility of the UGPT route network was identified. The relationship between the attributes of transport accessibility and the passengers’ frequency of using UGPT highlights significant differences between the perceived accessibility of transport and the frequency of using UGPT. Practical recommendations were formulated for developing transport accessibility for residents of megacities. The novelty of the research lies in the combined approach, which provides a deep understanding of causal relationships between customer experience (frequency of using UGPT) and the residents’ perceived accessibility of UGPT services. This helps to develop a theoretical model and practical recommendations for the improvement of the public UGPT system and transport services. Doi: 10.28991/ESJ-2023-07-06-023 Full Text: PD

Rational structural solutions for triangular trusses

Wooden rafter structures have undoubted advantages, which determine their wide application. The object of the study is triangular rafter structures. The purpose of the research is to find the dependence of force values in the elements of the studied structure on the magnitude of its lifting boom. The calculation of a triangular truss using the Maxwell - Cremona diagram is presented. The efficiency of the proposed method was estimated on the basis of a study of the structure of a wooden truss of the “scissors” type. The following pattern has been established: the change in the coordinates of the points (abscissas) of the force diagram is inversely proportional to the change in f . It is determined the area of rational values of the lift (roof slope) at which the values of internal forces tend to a minimum. It was revealed that the values of force increments in the truss elements at each step increase from 27% to 2 times when the roof slope de-creases. Based on the graphical analysis of the obtained data the range of effective values of the roof slope at which the forces in the elements of the truss take minimum values was found. Using a graphic method of determining the forces, it is possible to check variants of the roof slope in the search for a rational solution of the “scissor” type truss structure. It follows that the proposed method contributes to the choice of the most economical structural solutions

The low-temperature germinating spores of the thermophilic Desulfofundulus contribute to an extremely high sulfate reduction in burning coal seams

Burning coal seams, characterized by massive carbon monoxide (CO) emissions, the presence of secondary sulfates, and high temperatures, represent suitable environments for thermophilic sulfate reduction. The diversity and activity of dissimilatory sulfate reducers in these environments remain unexplored. In this study, using metagenomic approaches, in situ activity measurements with a radioactive tracer, and cultivation we have shown that members of the genus Desulfofundulus are responsible for the extremely high sulfate reduction rate (SRR) in burning lignite seams in the Altai Mountains. The maximum SRR reached 564 ± 21.9 nmol S cm−3 day−1 at 60°C and was of the same order of magnitude for both thermophilic (60°C) and mesophilic (23°C) incubations. The 16S rRNA profiles and the search for dsr gene sequences in the metagenome revealed members of the genus Desulfofundulus as the main sulfate reducers. The thermophilic Desulfofundulus sp. strain Al36 isolated in pure culture, did not grow at temperatures below 50°C, but produced spores that germinated into metabolically active cells at 20 and 15°C. Vegetative cells germinating from spores produced up to 0.738 ± 0.026 mM H2S at 20°C and up to 0.629 ± 0.007 mM H2S at 15°C when CO was used as the sole electron donor. The Al36 strain maintains significant production of H2S from sulfate over a wide temperature range from 15°C to 65°C, which is important in variable temperature biotopes such as lignite burning seams. Burning coal seams producing CO are ubiquitous throughout the world, and biogenic H2S may represent an overlooked significant flux to the atmosphere. The thermophilic spore outgrowth and their metabolic activity at temperatures below the growth minimum may be important for other spore-forming bacteria of environmental, industrial and clinical importance

Bose-Einstein correlations of charged hadrons in proton-proton collisions at s\sqrt s = 13 TeV

Bose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at $\sqrt{s}$ = 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at $\sqrt{s}$ = 7 TeV, as well as with theoretical predictions.[graphic not available: see fulltext]Bose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at $\sqrt{s} =$ 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at $\sqrt{s} =$ 7 TeV, as well as with theoretical predictions

BUYING BEHAVIOUR OF MILLENNIALS CHANGING TRADITIONAL MARKETING PRACTICES

People born roughly between 1980 and 2000 are commonly known as Millennial generation or Generation Y, who in the modern day they are entering adulthood. Millennial young adults are becoming of sharper social, academic and marketing focus due to the vastness of the generation, its growing impact on the society and increasing buying power. Identifying general definitive features of the chosen generation was made one of the thesis objectives. As a main objective of the study, the thesis sought to reveal the necessity and subsequently the nature of the marketing approach change in response to the chosen demographic phenomena in Western countries. Semi-structured in-depth interview was chosen as a data acquisition method. Interviews were conducted with 6 Millennial representatives from both entrepreneur and consumer side of marketing communication; all the interviews were conducted in spring 2016 in Helsinki Finland. Respondents from different countries residing in Helsinki had been chosen. Through collaboration of literature review and empirical study results generalised portraiture of Generation Y was developed and the importance of the Millennial customer was successfully revealed. Marketing communication adjustments through alternative to traditional channels use and tools application as well as the nature of the marketing message revision in order to establish quality relationship with the chosen demographics were discovered. Not to name one, the extensive list of suggested approach transformations were proposed by listing in the conclusion chapter of the thesis

Access to the Rail Station as a Customer Value: Simulation of Passenger Flows in Rail Stations with Disinfection Gateway Installations

This research applied secondary data collection methods to predict passenger flows, which involved analyzing traffic flows at rail stations and statistical methods, which involved assessing the relationship between variables and regression. Observation methods were used to measure current passenger flows at the rail station entrances. Passengers’ safety perception was assessed to understand the customer value of transport services. This assessment was based on an online survey, an analysis of official requests from passengers to the station directorates, and feedback from passengers and station visitors posted on the Internet. Traditional and content analysis methods were used to study passengers’ requests and feedbacks. It was substantiated that due to the COVID-19 pandemic, the concept of transportation security and the role of health safety as a customer value in passenger service have become more prominent. The possibility for passenger flow simulation to ensure people’s safe passage through a disinfection gateway is clearly shown. Public space management structures in transportation hubs can use the simulation results of this paper to solve the problem of passenger flow control along with installation of disinfection gateways at the station entrances for additional security. This is one of the few studies that explores the impact of using disinfection gateways to manage passenger flows in train stations

Access to the Rail Station as a Customer Value: Simulation of Passenger Flows in Rail Stations with Disinfection Gateway Installations

This research applied secondary data collection methods to predict passenger flows, which involved analyzing traffic flows at rail stations and statistical methods, which involved assessing the relationship between variables and regression. Observation methods were used to measure current passenger flows at the rail station entrances. Passengers’ safety perception was assessed to understand the customer value of transport services. This assessment was based on an online survey, an analysis of official requests from passengers to the station directorates, and feedback from passengers and station visitors posted on the Internet. Traditional and content analysis methods were used to study passengers’ requests and feedbacks. It was substantiated that due to the COVID-19 pandemic, the concept of transportation security and the role of health safety as a customer value in passenger service have become more prominent. The possibility for passenger flow simulation to ensure people’s safe passage through a disinfection gateway is clearly shown. Public space management structures in transportation hubs can use the simulation results of this paper to solve the problem of passenger flow control along with installation of disinfection gateways at the station entrances for additional security. This is one of the few studies that explores the impact of using disinfection gateways to manage passenger flows in train stations