scholarly journals Investigation on particulate matter and gas motion processes in the advanced multi-channel cyclone-separator with secondary gas inlets

2021 ◽  
Vol 27 (1) ◽  
pp. 200550-0
Author(s):  
Pranas Baltrėnas ◽  
Andrea Crivellini ◽  
Terese Leonavičienė ◽  
Aleksandras Chlebnikovas
Keyword(s):  
Particulate Matter ◽  
Gas Flow ◽  
Experimental Studies ◽  
Flow Conditions ◽  
Computational Accuracy ◽  
Flow Motion ◽  
The Impact ◽  
Omega Model ◽  
Principal Elements

Research into gas flow motion as a transported phase and pollutant – particulate matter (PM) is of crucial importance, their changes in particular areas of the object require knowledge of improving the apparatus. A cyclone is considered one of the most popular devices due to the new modified multi-channel design that involves combined separation and filtration phenomena. The findings of an accurate numerical model provide an opportunity to verify long-term experimental studies. In addition, it is possible to determine the impact of the designed principal elements of the structure comprising secondary gas inlets, inner slits and the convex bottom on gas and PM motion through verification conducting experimental research. The study focuses on simulating the upgraded cyclone using the SST k-omega model. The research has been conducted under the specified gas flow conditions such as high temperature and relative humidity (aggressive) gas and presents the results of the physical model to compare with. To achieve greater computational accuracy, a digital model of the cyclone made of specific volumetric elements has been developed thus expanding the grid and stepping to form the boundary zone. As a result, numerical simulation results differ by no more than 12.8% compared to the experimental studies results.

scholarly journals Dietary Pattern and Long-Term Effects of Particulate Matter on Blood Pressure: A Large Cross-Sectional Study in Chinese Adults

Hypertension ◽  
2021 ◽  
Author(s):  
Huan Xu ◽  
Bing Guo ◽  
Wen Qian ◽  
Zhuoga Ciren ◽  
Wei Guo ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Particulate Matter ◽  
Dietary Pattern ◽  
Regression Models ◽  
Experimental Studies ◽  
Dash Score ◽  
Odds Ratios ◽  
Chinese Adults ◽  
Dash Diet

Previous experimental studies have identified specific foods or nutrients are capable of mitigating adverse effects induced by air pollution. However, whether the dietary pattern can modify the associations between long-term particulate matter (PM) and increasing blood pressure (BP) among adults has not yet been assessed. We assessed whether the dietary pattern and various foods modify the associations between long-term exposure to PM (PM 1 , PM 2.5 , and PM 10 ), hypertensive BP (BP≥140/90 mm Hg, HBP), and BP in Chinese adults. This study included 61 081 participants from China Multi-Ethnic Cohort. PM was assessed through satellite-based random forest approaches. Outcomes were analyzed with logistic regression models and linear regression models. The dietary approaches to stop hypertension (DASH) diet was calculated for each participant. This study founds long-term exposure to PM was associated with HBP, systolic BP, and pulse pressure. The DASH diet modified the associations between PM, HBP, and some BP components. For each 10 μg/m 3 increase in PM 1 , PM 2.5 , and PM 10 , the participants with the lowest quintile of DASH score had HBP risks with odds ratios (95% CI) of 1.196 (1.084–1.319), 1.145 (1.09–1.202), and 1.080 (1.045–1.117), whereas those with the highest quintile of DASH score had lower HBP risks with odds ratios (95% CI) of 1.063 (0.953–1.185), 1.074 (1.017–1.133), and 1.038 (1.000–1.077). Consuming more fresh fruits, vegetables, dairy, and whole grains would reduce the risk of raised BP caused by PM. In conclusion, the DASH diet rich in antioxidant compounds may be a wide-reaching intervention to reduce the deleterious impact of PM.

scholarly journals Numerical and Experimental Investigations on Optimized 3D Compressor Airfoils

2018 ◽  
Author(s):  
Jan Mihalyovics ◽  
Christian Brück ◽  
Dieter Peitsch ◽  
Ilias Vasilopoulos ◽  
Marcus Meyer
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Experimental Studies ◽  
Total Pressure Loss ◽  
Design Parameters ◽  
Flow Conditions ◽  
Flow Angle ◽  
Flow Phenomena ◽  
The Impact ◽  
Stator Design

The objective of the presented work is to perform numerical and experimental studies on compressor stators. This paper presents the modification of a baseline stator design using numerical optimization resulting in a new 3D stator. The Rolls Royce in-house compressible flow solver HYDRA was employed to predict the 3D flow, solving the steady RANS equations with the Spalart-Allmaras turbulence model, and its corresponding discrete adjoint solver. The performance gradients with respect to the input design parameters were used to optimize the stator blade with respect to the total pressure loss over a prescribed incidence range, while additionally minimizing the flow deviation from the axial direction at the stator exit. Non-uniform profile boundary conditions, being derived from the experimental measurements, have been defined at the inlet of the CFD domain. The presented results show a remarkable decrease in the axial exit flow angle deviation and a minor decrease in the total pressure loss. Experiments were conducted on two compressor blade sets investigating the three-dimensional flow in an annular compressor stator cascade. Comparing the baseline flow of the 42° turning stator shows that the optimized stator design minimizes the secondary flow phenomena. The experimental investigation discusses the impact of steady flow conditions on each stator design while focusing on the comparison of the 3D optimized design to the baseline case. The flow conditions were investigated using five-hole probe pressure measurements in the wake of the blades. Furthermore, oil-flow visualization was applied to characterize flow phenomena. These experimental results are compared with the CFD calculations.

scholarly journals Plasmodium falciparum schizont stage transcriptome variation among clinical isolates and laboratory-adapted clones

2018 ◽  
Author(s):  
Sarah J Tarr ◽  
Ofelia Díaz-Ingelmo ◽  
Lindsay B Stewart ◽  
Suzanne E Hocking ◽  
Lee Murray ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Vaccine Development ◽  
Ex Vivo ◽  
Experimental Studies ◽  
Differentially Expressed ◽  
Clinical Isolates ◽  
Schizont Stage ◽  
Variable Expression ◽  
The Impact

AbstractMalaria parasite genes exhibit variation in both sequence and expression level. There is much information on sequence polymorphism, but less resolution on natural variation in transcriptomes of parasites at specific developmental stages. This is largely because it is challenging to obtain highly replicated sampling of transcriptomes to overcome potentially confounding technical and biological variation. We address the issue in the major human parasite Plasmodium falciparum by obtaining RNA-seq profiles of multiple independent replicate preparations of mature schizont-stage parasites from a panel of clinical isolates recently established in culture and from long-term laboratory-adapted clones. With a goal of robustly identifying variably expressed genes, we show that increasing the numbers of biological sample replicates greatly improves the discovery rate. Generally, six independent replicates of each parasite culture is recommendable as being significantly to lower numbers, although for highly expressed genes variable expression can be detected when fewer replicates are available. A broad comparison identifies genes differing in relative expression between cultured clinical isolates and laboratory-adapted clones. Genes more highly expressed in the laboratory-adapted clones include an AP2 transcription factor gene Pf3D7_0420300 and putative methyl transferase genes. The variable expression of several known merozoite invasion ligands is confirmed, and previously uncharacterised genes are shown to be differentially expressed among clinical isolates. New RT-qPCR assays validate the variation in transcript levels of these genes, and allow quantitation of expression to be extended to a wider panel of clinical isolate samples. These variably expressed genes are new candidates for investigation as potential determinants of alternative parasite developmental pathways or targets of immunity.Author summaryUnderstanding parasite diversity and adaptation may require characterisation of gene expression variation, and is vital if chemotherapeutic or vaccine development is to consider new candidate targets, but it is technically challenging to generate precise data on clinical isolates. Here, we analyse the transcriptomes of mature Plasmodium falciparum schizonts using RNA-sequencing, using large numbers of biological replicate samples to minimise the impact of inter-replicate variation on observed patterns of differential expression. This identifies genes that are differentially expressed in long term laboratory-adapted parasites and recently cultured clinical isolates, as well as among different clinical isolates. In additional samples of schizonts grown in the first cycle ex vivo prior to any erythrocyte invasion, expression levels of a selected panel of these genes vary among isolates, but mean levels are similar to those in the continuously cultured clinical isolates, indicating that the latter are useful for experimental studies requiring biological replication.

scholarly journals RESEARCH OF EFFICIENCY ECOLOGICAL DIAGNOSTICS SYSTEM OF HEAT ENGINES AND BOILER PLANTS

2019 ◽  
Vol 6 (152) ◽  
pp. 73-78
Author(s):  
A. Polivyanchuk ◽  
M. Smirny ◽  
S. Romanenko ◽  
R. Semenenko ◽  
R. Plotnikova ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Measurement Errors ◽  
Experimental Studies ◽  
Diagnostic System ◽  
Measuring System ◽  
Methodological Error ◽  
Heat Engines ◽  
Accuracy Of Measurements ◽  
Diagnostics System ◽  
The Impact

A universal, multifunctional system of environmental diagnostics of heat engines and boiler plants has been created, which allows one to determine indicators characterizing the chemical and physical effect of these objects on the environment: concentrations, mass, specific and average operational emissions of pollutants, noise, thermal pollution, vibration. This measuring system consists of instrumental, testing, demonstration and laboratory modules, which allows you to use it as a diagnostic tool, training and test bench and laboratory; as well as apply it in various fields: transport, energy, environmental and educational fields. The diagnostic system implements methods for monitoring and improving the accuracy of measurements of average operating emissions of pollutants: method for determining the resulting measurement errors of the average operational emissions of gaseous pollutants and particulate matter – GAS and РT indicators, which allows you to evaluate the impact on the data of the value of the errors of the measuring equipment of the diagnostic system; a method for increasing the accuracy of measurements of the normalized РT index by taking into account the methodological error of measurements of a given value due to the influence of the temperature of the sample in the tunnel on the measured emission of particulate matter - δРТt. Experimental studies of the diagnostic system and methods for increasing its accuracyon full-scale objects were carried out: diesel engines: tractor 4CHN12/14 tractor D65M, diesel locomotive diesel engine DEL-01 and boiler units: gas - DKVR-20/13 and AOGV-100E, solid fuel - KCHM-2M-4. Transport diesels were tested according to the cycles established by the UNECE Regulations R-49, R-96 and the international standard ISO-8178. As a result of tests of these engines, the coefficients KРi, KMgasi and KMрmi were determined, which are used to assess the accuracy of measurements of GAS and РT indicators, the resulting measurement errors of these values were investigated and the range of variation of the methodical error δРТt was determined.

scholarly journals Spatio-Temporal Variation in the Concentration of Inhalable Particulate Matter (PM10) in Uganda

2019 ◽  
Vol 16 (10) ◽  
pp. 1752 ◽  
Author(s):  
Silver Onyango ◽  
Beth Parks ◽  
Simon Anguma ◽  
Qingyu Meng
Keyword(s):  
Particulate Matter ◽  
Sampling Period ◽  
Ambient Air ◽  
Average Density ◽  
Diurnal Variations ◽  
Time Data ◽  
Seasonal Differences ◽  
Wide Range ◽  
The Impact

Long-term particulate matter (PM10) measurements were conducted during the period January 2016 to September 2017 at three sites in Uganda (Mbarara, Kyebando, and Rubindi) representing a wide range of urbanization. Spatial, temporal and diurnal variations are assessed in this paper. Particulate matter (PM10) samples were collected for 24-h periods on PTFE filters using a calibrated pump and analyzed gravimetrically to determine the average density. Particulate levels were monitored simultaneously using a light scattering instrument to acquire real time data from which diurnal variations were assessed. The PM10 levels averaged over the sampling period at Mbarara, Kyebando, and Rubindi were 5.8, 8.4, and 6.5 times higher than the WHO annual air quality guideline of 20 µg·m−3, and values exceeded the 24-h mean PM10 guideline of 50 µg·m−3 on 83, 100, and 86% of the sampling days. Higher concentrations were observed during dry seasons at all sites. Seasonal differences were statistically significant at Rubindi and Kyebando. Bimodal peaks were observed in the diurnal analysis with higher morning peaks at Mbarara and Kyebando, which points to the impact of traffic sources, while the higher evening peak at Rubindi points to the influence of dust suspension, roadside cooking and open-air waste burning. Long-term measurement showed unhealthy ambient air in all three locations tested in Uganda, with significant spatial and seasonal differences.

Abstract 3133: Impact of Post-stroke Isolation on Stroke Outcome

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Venugopal R Venna ◽  
Yan Xu ◽  
Jun Li ◽  
Fudong Liu ◽  
Louise D McCullough
Keyword(s):  
Infarct Size ◽  
Functional Recovery ◽  
Forced Swim Test ◽  
Statistical Significance ◽  
Experimental Studies ◽  
Stroke Recovery ◽  
Stroke Outcome ◽  
Post Stroke ◽  
The Impact

Background: Psychosocial factors are increasingly accepted as critical factors in post-stroke recovery, mortality and morbidity. Although, emerging data from clinical and population based studies support the role of social support in improved functional recovery and reducing the risk of mortality, to date no experimental studies have investigated such effects in post-stroke animal models. The aim of this study is to investigate for the impact of post stroke housing and the effects of long-term social isolation and pair housing with either a healthy or a stroked partner, and explored for the mechanisms. Methods: Male mice (20-25g; C57BL/6N, Charles River Labs), all initially pair housed, were subjected to right middle cerebral artery occlusion (MCAO - 60min) and then randomly assigned to a specific housing condition - isolated, paired with a stroke partner or paired with a healthy partner. Infarct size was quantified with TTC 72h after stroke (n=8/grp). We then investigated the effects of housing on long-term functional recovery using corner test, cylinder test, forced swim test (FST) and tail suspension test (TST). We further explored the mechanisms underlying the improved behavioral recovery by injecting BrDU 150mg/kg/day i.p. for 5 days starting from day 3 post-stroke (n=8/grp), and assessing changes in BDNF levels by western-blot analysis (n=4/grp). Data were expressed as mean±sem. Two-way ANOVA was performed and P value < .05 was set for statistical significance. Results: Post-stroke housing conditions can significantly impact infarct size; we observed that mice isolated after stroke had increased infarct volume compared to pair housed mice in all three brain regions (Cortex: 63.2±2.5 vs 40.0±6.2; p<0.01); (Striatum: 86.6±2.2 vs 67.7±2.9; p<0.01); (Total: 60.9±1.3 vs 32.6±4.3; p<0.01). Although post-stroke housing with healthy vs a stroked partner did not influenced infarct size (p>0.05), animals pair housed with healthy partner showed a significantly improved functional recovery by as early as day 15 in the cylinder and corner tests (p<0.05). Increased mobility was observed in FST and TST in PH mice compared to SI mice at day 90 (p<0.05). Consistently, housing with a healthy partner increased BrDU positive cells (p<0.05) and enhanced BDNF expression compared to other cohorts (SI 1±0.1; PH with stroke partner 1.9±0.2; PH with healthy partner 2.6±0.1; n=4/grp), no changes were seen in sham mice. Conclusions: Post-stroke housing has an important impact on stroke outcome; isolation has a detrimental effect on infarct size compared to pair housed cohorts. Interestingly, independent of infarct size, housing with a healthy partner hastened recovery compared to those stroke mice housed with partner that had also been subjected to stroke. Molecular analysis indicates the involvement of BDNF and neurogenesis may be important regulators of post-stroke housing induced functional recovery.

The impact of corporate social responsibility (CSR) priming on consumers’ consumption and lifestyle choices with intertemporal tradeoffs

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hajar Fatemi ◽  
Laurette Dube
Keyword(s):  
Corporate Social Responsibility ◽  
Social Responsibility ◽  
Experimental Studies ◽  
Unhealthy Food ◽  
Content Type ◽  
Trade Offs ◽  
Lifestyle Choices ◽  
Corporate Social ◽  
The Impact

Purpose This paper aims to study the unexplored possibility that priming firms’ corporate social responsibility (CSR) activity in consumers’ minds may impact consumers’ preference for non-firm related consumption and lifestyle choice options with intertemporal trade-offs. Design/methodology/approach Across four experimental studies, the authors looked at the impact of CSR priming on the preference of participants for later larger versus sooner smaller money (Study 1), saving versus spending (Study 2) and healthy versus unhealthy food choices (Studies 3 and 4). These choice options were not related to the focal firm that practiced CSR. The authors measured the changes in participants’ consideration of future consequences (CFC) as a potential mediator for the results. Findings The participants in the CSR condition showed a higher CFC and a higher preference for the options with long-term benefits and immediate costs over the ones with long-term costs and immediate benefits, i.e. later larger over sooner smaller money, saving over spending and healthy over unhealthy food. The authors documented a mediation role for CFC. Research limitations/implications All the participants in the studies were from the USA. Looking at the cultural differences can enrich the understanding of the impact of CSR on preference for the options with intertemporal trade-offs. Furthermore, this paper builds its theoretical justification based on the assumption of individuals’ acceptance of CSR activities. Nevertheless, consumers may have skepticism about these activities. Future studies may investigate the effect of CSR skepticism of individuals on the proposed effects. Additionally, investigating the moderating roles of individuals’ characteristics like their prosocial concern or their knowledge about choice options might be an avenue for future research. Practical implications The findings highlight the benefits of CSR priming on consumers’ welfare and normative behavior. Firms may use the findings to understand and manage the impact of other firms’ CSR communications on the evaluation of their own products. Originality/value This research is the first to highlight the impact of CSR priming on consumers’ non-firm-related consumption and lifestyle choices with intertemporal trade-offs. The results showed the positive effect of priming firms’ CSR activities on consumers’ CFC and the mediating role of CFC.

Impact of long-term experimental water level drawdown on vegetation and carbon gas dynamics of boreal mire ecosystems

2020 ◽  
Author(s):  
Eeva-Stiina Tuittila ◽  
Aino Korrensalo ◽  
Anna Laine ◽  
Nicola Kokkonen ◽  
Lauri Mehtätalo ◽  
...  
Keyword(s):  
Water Level ◽  
Gas Dynamics ◽  
Experimental Studies ◽  
Net Ecosystem Exchange ◽  
Woody Species ◽  
Long Term Results ◽  
Moss Species ◽  
Poor Fen ◽  
The Impact

&lt;p&gt;Recent paleoecological studies have demonstrated an ongoing drying trend in temperate and boreal peatlands in Europe and in Canada. This drying is likely to alter vegetation and carbon gas exchange with atmosphere. However, to revel the expected change in carbon gas dynamics associated with decrease in water level experimental studies and long-term monitoring are needed. In here we present results from long term experiment in Finland where the impact of water level drawdown (WLD) of ~10 cm on three different peatland sites, two fens and a bog, has been studied since year 2000.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Response to WLD differed between the three ecosystem types. In the nutrient rich fen WLD initiated rapid directional succession from sedge dominated system to the dominance of woody species. In the poor fen changes were less drastic: Initially WLD benefitted dwarf scrubs already present at the site, later they were overtaken by pines.&amp;#160; Sedges as a group hold their position but Carex species were replaced by Eriophorum. Similarly to sedges, in the moss layer proportions of different Sphagnum moss species changed. Bog vegetation was more stable than fen vegetation.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;In all the ecosystems methane emissions decreased directly after WLD. In contrast, the response of CO2 dynamics was more complex. While long term net ecosystem exchange decreased to lower level than in controls in all studied ecosystems, the response of photosynthesis and respiration differed between the three ecosystems and between short term and long term. Results show how the response of peatlands to climate change is diverse and emphasize the need to understand what factors regulate the stability and resilience of peatland functioning.&lt;/p&gt;

scholarly journals Avoidable Mortality Attributable to Anthropogenic Fine Particulate Matter (PM2.5) in Australia

2020 ◽  
Vol 18 (1) ◽  
pp. 254
Author(s):  
Ivan C. Hanigan ◽  
Richard A. Broome ◽  
Timothy B. Chaston ◽  
Martin Cope ◽  
Martine Dennekamp ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Fine Particulate Matter ◽  
Weighted Average ◽  
Attributable Mortality ◽  
Years Of Life Lost ◽  
Avoidable Mortality ◽  
Death Rates ◽  
Fine Particulate ◽  
The Impact

Ambient fine particulate matter <2.5 µm (PM2.5) air pollution increases premature mortality globally. Some PM2.5 is natural, but anthropogenic PM2.5 is comparatively avoidable. We determined the impact of long-term exposures to the anthropogenic PM component on mortality in Australia. PM2.5-attributable deaths were calculated for all Australian Statistical Area 2 (SA2; n = 2310) regions. All-cause death rates from Australian mortality and population databases were combined with annual anthropogenic PM2.5 exposures for the years 2006–2016. Relative risk estimates were derived from the literature. Population-weighted average PM2.5 concentrations were estimated in each SA2 using a satellite and land use regression model for Australia. PM2.5-attributable mortality was calculated using a health-impact assessment methodology with life tables and all-cause death rates. The changes in life expectancy (LE) from birth, years of life lost (YLL), and economic cost of lost life years were calculated using the 2019 value of a statistical life. Nationally, long-term population-weighted average total and anthropogenic PM2.5 concentrations were 6.5 µg/m3 (min 1.2–max 14.2) and 3.2 µg/m3 (min 0–max 9.5), respectively. Annually, anthropogenic PM2.5-pollution is associated with 2616 (95% confidence intervals 1712, 3455) deaths, corresponding to a 0.2-year (95% CI 0.14, 0.28) reduction in LE for children aged 0–4 years, 38,962 (95%CI 25,391, 51,669) YLL and an average annual economic burden of $6.2 billion (95%CI $4.0 billion, $8.1 billion). We conclude that the anthropogenic PM2.5-related costs of mortality in Australia are higher than community standards should allow, and reductions in emissions are recommended to achieve avoidable mortality.

scholarly journals Vision of the role of long-term social stress in the formation of "diseases of civilization". mechanisms of adaptation to stressor situations and factors of its failure

2021 ◽  
Vol 11 (10) ◽  
pp. 325-331
Author(s):  
O. Hancheva ◽  
K. Romanova
Keyword(s):  
Social Stress ◽  
Experimental Studies ◽  
Human Diseases ◽  
Stress Reactions ◽  
Sources Of Information ◽  
Negative Effects ◽  
Scientific Publications ◽  
The Impact

Today, the issue of studying the mechanisms of the impact of social stress on public health and its role in the formation of key human diseases is relevant and necessary. A large number of works, both clinical observations and experimental studies, are devoted to this problem. However, despite the high interest in this problem, there are still "white spots". Therefore, the purpose of our study was to analyze modern sources of information that highlight current issues of long-term social stress and its role in the formation of "diseases of civilization." Matherials and methods: analysis of scientific publications from the following databases: Google Scholar, Web of Science, Pub Med, by keywords: rats, social stress, diseases of civilization, neuroendocrine regulation, hypothalamus, supraoptic nucleus, paravetricular nucleus. Conclusions: Thus, the analysis of resources shows the undoubted role of stress in the formation of human diseases. Many articles are devoted to the description and analysis of the negative effects of environmental factors and peculiarities of living conditions on human health. Most researchers agree on the key role of the hypothalamus in regulating the body's stress response and the presence of morphofunctional changes associated with stress. It is important to note that scientists have paid much attention to the study of individual models of stress, namely pain, immobilization and hypoxic over the past 20 years. Unfortunately, there are few facts concerning the analysis of the influence of long-term negative social factors that do not cause stereotyped reactions, but form latent changes that are inherent in classical stress reactions.

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