scholarly journals Methodical approach to determining permissible time limits of intermittent carbon monoxide exposure in rescuers

2021 ◽  
pp. 82-88
Author(s):  
D. V. Myasnikov ◽  
P. V. Avitisov ◽  
A. V. Zolotukhin ◽  
M. F. Barinov
Keyword(s):  
Carbon Monoxide ◽  
Large Scale ◽  
Operation Time ◽  
Theoretical Data ◽  
Combustion Products ◽  
Research Area ◽  
Time Limits ◽  
Emergency Rescue ◽  
Functional Relationships ◽  
Methodical Approach

Relevance. Current operation time limits under hazardous chemical conditions (“emergency regulations”) have been developed mainly for a limited number of emergency situations occurring in spacecraft, submarines or other specific objects. At the same time, many emergencies accompanied by large-scale releases of toxic combustion products from various materials and compounds into the environment are not limited to these facilities. Therefore, risks associated with toxic effects of chemicals should be predicted, since permissible time limits with adequate performance of personnel under certain chemical exposures are used for individual protection (time-based protection).Intention: On the basis of physiological aspects, the peculiarities of the work performed by rescuers and the requirements for organizing and conducting emergency rescue operations, to propose a methodical approach to determining the permissible time for rescuers in conditions of intermittent carbon monoxide release.Methodology. The scientific works and results of experiments in the research area were analyzed. Systematization and generalization of empirical and theoretical data, traditional analysis of documents and publications were used with the least squares approximation.Results and Discussion. Specific effects of various carbon monoxide concentrations are shown for different exposure times. Critical concentrations and exposure times are revealed, functional relationships between permissible time of operation and carbon monoxide concentrations are determined. Carboxyhemoglobin formation and effects were taken into account.Conclusion. The data given in the article are an important basis for organizing and conducting emergency rescue operations at increased concentrations of carbon monoxide.

scholarly journals Development and evaluation of a monoclonal antibody-based competitive ELISA for the detection of antibodies against H7 avian influenza virus

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Yuan Li ◽  
Hongliu Ye ◽  
Meng Liu ◽  
Suquan Song ◽  
Jin Chen ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Large Scale ◽  
Operation Time ◽  
Reference Method ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Concentration

Abstract Background H7 subtype avian influenza has caused great concern in the global poultry industry and public health. The conventional serological subtype-specific diagnostics is implemented by hemagglutination inhibition (HI) assay despite lengthy operation time. In this study, an efficient, rapid and high-throughput competitive enzyme-linked immunosorbent assay (cELISA) was developed for detection of antibodies against H7 avian influenza virus (AIV) based on a novel monoclonal antibody specific to the hemagglutinin (HA) protein of H7 AIV. Results The reaction parameters including antigen coating concentration, monoclonal antibody concentration and serum dilution ratio were optimized for H7 antibody detection. The specificity of the cELISA was tested using antisera against H1 ~ H9, H11 ~ H14 AIVs and other avian viruses. The selected cut-off values of inhibition rates for chicken, duck and peacock sera were 30.11, 26.85 and 45.66% by receiver-operating characteristic (ROC) curve analysis, respectively. With HI test as the reference method, the minimum detection limits for chicken, duck and peacock positive serum reached 20, 21 and 2− 1 HI titer, respectively. Compared to HI test, the diagnostic accuracy reached 100, 98.6, and 99.3% for chicken, duck and peacock by testing a total of 400 clinical serum samples, respectively. Conclusions In summary, the cELISA assay developed in this study provided a reliable, specific, sensitive and species-independent serological technique for rapid detection of H7 antibody, which was applicable for large-scale serological surveillance and vaccination efficacy evaluation programs.

A Simple, Large-Scale Overexpression Method of Deriving Carbon Monoxide Dehydrogenase II from Thermophilic BacteriumCarboxydothermus hydrogenoformans

2011 ◽  
Vol 75 (7) ◽  
pp. 1392-1394 ◽  
Author(s):  
Takahiro INOUE ◽  
Takashi YOSHIDA ◽  
Kei WADA ◽  
Takashi DAIFUKU ◽  
Keiichi FUKUYAMA ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Large Scale ◽  
Carbon Monoxide Dehydrogenase

Advances in Water Treatment Application of Sepiolite Mineral Materials

2013 ◽  
Vol 710 ◽  
pp. 217-220 ◽  
Author(s):  
Fei Wang ◽  
Lei Feng ◽  
Meng Ran Tang ◽  
Ji Yuan Li ◽  
Qing Guo Tang
Keyword(s):  
Water Treatment ◽  
Size Effect ◽  
Large Scale ◽  
Surface Effect ◽  
Development Trend ◽  
High Energy ◽  
Research Area ◽  
Group Mineral ◽  
Active Research ◽  
Treatment Application

Synthetic nanomaterials have the disadvantages of large-scale investment, high energy consumption, complex production process and heavy environmental load. Mineral nanomaterials such as sepiolite group mineral nanomaterials are characterized by small size effect, quantum size effect and surface effect. Water treatment application of sepiolite group mineral nanomaterials has become an active research area and showed good development and application prospects. Based on the above reasons, this paper systematically summarizes the water treatment application of sepiolite group mineral nanomaterials, and development trend related to water treatment application of sepiolite group mineral nanomaterials were also proposed.

Turbulent Three-Dimensional Air Flow and Trace Gas Distribution in an Inhalation Test Chamber

2000 ◽  
Vol 122 (2) ◽  
pp. 403-411 ◽  
Author(s):  
P. W. Longest, ◽  
C. Kleinstreuer ◽  
J. S. Kinsey
Keyword(s):  
Carbon Monoxide ◽  
Large Scale ◽  
Air Flow ◽  
Test Chamber ◽  
Secondary Flows ◽  
Vortical Flow ◽  
Trace Gas ◽  
Inlet Section ◽  
Height Range ◽  
Co Concentrations

Steady incompressible turbulent air flow and transient carbon monoxide transport in an empty Rochester-style human exposure chamber have been numerically simulated and compared with experimental data sets. The system consisted of an inlet duct with a continuous carbon monoxide point source, 45- and 90-degree bends, a round diffuser, a round-to-square transition, a rectangular diffuser, the test chamber, a perforated floor, and again transition pieces from the chamber to an outlet duct. Such a configuration induced highly nonuniform vortical flow patterns in the chamber test area where a pollutant concentration is required to be constant at breathing level for safe and accurate inhalation studies. Presented are validated momentum and mass transfer results for this large-scale system with the main goals of determining the development of tracer gas (CO) distributions in the chamber and analyzing the contributions to CO-mixing. Numerical simulations were conducted employing a k-ε model and the latest available RNG k-ε model for air and CO-mixing. Both models predict similar velocity fields and are in good agreement with measured steady and transient CO-concentrations. It was found that secondary flows in the inlet section and strong vortical flow in the chamber with perforated flooring contributed to effective mixing of the trace gas at breathing levels. Specifically, in the height range of 1.4 m<h<2.0 m above the chamber floor, predicted CO-concentrations rapidly reached a near constant value which agrees well with experimental results. This work can be extended to analyze trace gas mixing as well as aerosol dispersion in occupied test chambers with or without flow redirection devices installed in the upstream section. A complementary application is particle transport and deposition in clean rooms of the electronic, pharmaceutical, and health care industries. [S0098-2202(00)01702-8]

scholarly journals Carbon monoxide and related trace gases and aerosols over the Amazon Basin during the wet and dry seasons

2012 ◽  
Vol 12 (13) ◽  
pp. 6041-6065 ◽  
Author(s):  
M. O. Andreae ◽  
P. Artaxo ◽  
V. Beck ◽  
M. Bela ◽  
S. Freitas ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Southern Hemisphere ◽  
Biomass Burning ◽  
Large Scale ◽  
Amazon Basin ◽  
Photochemical Degradation ◽  
Wet Season ◽  
Biomass Smoke ◽  
Airborne Measurements ◽  
Basin Scale

Abstract. We present the results of airborne measurements of carbon monoxide (CO) and aerosol particle number concentration (CN) made during the Balanço Atmosférico Regional de Carbono na Amazônia (BARCA) program. The primary goal of BARCA is to address the question of basin-scale sources and sinks of CO2 and other atmospheric carbon species, a central issue of the Large-scale Biosphere-Atmosphere (LBA) program. The experiment consisted of two aircraft campaigns during November–December 2008 (BARCA-A) and May–June 2009 (BARCA-B), which covered the altitude range from the surface up to about 4500 m, and spanned most of the Amazon Basin. Based on meteorological analysis and measurements of the tracer, SF6, we found that airmasses over the Amazon Basin during the late dry season (BARCA-A, November 2008) originated predominantly from the Southern Hemisphere, while during the late wet season (BARCA-B, May 2009) low-level airmasses were dominated by northern-hemispheric inflow and mid-tropospheric airmasses were of mixed origin. In BARCA-A we found strong influence of biomass burning emissions on the composition of the atmosphere over much of the Amazon Basin, with CO enhancements up to 300 ppb and CN concentrations approaching 10 000 cm−3; the highest values were in the southern part of the Basin at altitudes of 1–3 km. The ΔCN/ΔCO ratios were diagnostic for biomass burning emissions, and were lower in aged than in fresh smoke. Fresh emissions indicated CO/CO2 and CN/CO emission ratios in good agreement with previous work, but our results also highlight the need to consider the residual smoldering combustion that takes place after the active flaming phase of deforestation fires. During the late wet season, in contrast, there was little evidence for a significant presence of biomass smoke. Low CN concentrations (300–500 cm−3) prevailed basinwide, and CO mixing ratios were enhanced by only ~10 ppb above the mixing line between Northern and Southern Hemisphere air. There was no detectable trend in CO with distance from the coast, but there was a small enhancement of CO in the boundary layer suggesting diffuse biogenic sources from photochemical degradation of biogenic volatile organic compounds or direct biological emission. Simulations of CO distributions during BARCA-A using a range of models yielded general agreement in spatial distribution and confirm the important contribution from biomass burning emissions, but the models evidence some systematic quantitative differences compared to observed CO concentrations. These mismatches appear to be related to problems with the accuracy of the global background fields, the role of vertical transport and biomass smoke injection height, the choice of model resolution, and reliability and temporal resolution of the emissions data base.

scholarly journals A 10-Year Follow-Up of Two-Incision and Modified Watson-Jones Total Hip Arthroplasty in Patients with Osteonecrosis of the Femoral Head

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Shih-Jie Lin ◽  
Tsan-Wen Huang ◽  
Po-Chun Lin ◽  
Feng-Chih Kuo ◽  
Kuo-Ti Peng ◽  
...  
Keyword(s):  
Femoral Head ◽  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Functional Outcomes ◽  
Large Scale ◽  
Operation Time ◽  
Harris Hip Score ◽  
Total Hip ◽  
Radiographic Parameters

Long-term data and information indicating whether minimally invasive surgery (MIS) approaches are safe and effective with total hip arthroplasty (THA) are lacking. Between 2004 and 2006, 75 patients with alcohol-related osteonecrosis of the femoral head (ONFH) who underwent 75 THAs with the two-incision approach were studied. The medical records, radiographic parameters, and functional outcomes were collected prospectively. All data were compared with those for matched patients who underwent a modified Watson-Jones (WJ) approach. THA using the two-incision approach was associated with longer operation time, more blood loss, more lateral femoral cutaneous nerve injury, and more periprosthetic femoral fractures (p<0.05for all four) than the modified WJ approach. The Harris Hip Score (HHS) and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) increased significantly from the period preoperatively to 6 weeks postoperatively and thereafter up to the last follow-up in both groups. However, there were no significant differences in terms of radiographic parameters and functional outcomes between the two groups throughout the study period. Both the two-incision and the modified WJ approach provided satisfactory results and survival rates at a mean follow-up of 10.8 years. A prospective, randomized, large-scale cohort study is still warranted for evidence-based recommendations.

Wavelet analysis of the temporal-spatial distribution in the Eurasia seismic belt

2017 ◽  
Vol 15 (03) ◽  
pp. 1750018 ◽  
Author(s):  
Wenfeng Zheng ◽  
Xiaolu Li ◽  
Lirong Yin ◽  
Zhengtong Yin ◽  
Bo Yang ◽  
...  
Keyword(s):  
Fault Zone ◽  
Compact Support ◽  
Large Scale ◽  
Temporal Distribution ◽  
Seismic Energy ◽  
Research Area ◽  
Earthquake Activity ◽  
Seismic Zone ◽  
Seismic Belt ◽  
Earthquake Fault

Due to the growing frequency of earthquakes, safeties of human lives and properties are facing serious threats. However, the research in the field of spatial-temporal distribution of earthquake is quite a few. In this paper, we use wavelet model to analyze the spatial-temporal distribution of earthquakes. Because the spatial-temporal distribution of earthquake activity is closely related to the distribution of the earthquake fault zone, we analyze large-scale earthquake clusters by selecting the Eurasia seismic belt and the surrounding region as the research area. From the perspective of the time domain, the results show that the seismic energy of the earthquake fault zone presences compact support or similar compact support distribution, suggesting that the seismic zone exists a relatively quiet period and active stage. This indicate that the seismic zone is periodical. The period of strong earthquakes above normal and less than normal is different by time changes. The cycles of earthquakes are different due to different regions and different geological and geographical environment.

Prediction of CO and NOx Pollutants in a Stratified Bluff Body Burner

2017 ◽  
Author(s):  
Pascal Gruhlke ◽  
Fabian Proch ◽  
Andreas M. Kempf ◽  
Enric Illana Mahiques ◽  
Stefan Dederichs ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Bluff Body ◽  
Combustion Products ◽  
Combustion Model ◽  
Wide Range ◽  
Flame Region ◽  
Numerical Grid ◽  
Nitric Oxide Emissions ◽  
Heavy Duty Gas Turbine

The major exhaust gas pollutants from heavy duty gas turbine engines are CO and NOx. The difficulty of predicting the concentration of these combustion products originates from their wide range of chemical time scales. In this paper, a combustion model that includes the prediction of the carbon monoxide and nitric oxide emissions is tested. Large eddy simulations (LES) are performed using a compressible code (OpenFOAM). A modified flamelet generated manifolds (FGM) approach is applied with a thickened flame approach (ATF) to resolve the flame on the numerical grid, with a flame sensor to ensure that the flame is only thickened in the flame region. For the prediction of the CO and NOx emissions, pollutant species transport equations and a second, CO based, progress variable are introduced for the flame burnout zone to account for slow chemistry effects. For the validation of the models, the Cambridge burner of Sweeney and Hochgreb [1, 2] is employed, as both carbon monoxide and nitric oxide [3] data is available.

scholarly journals Tropical troposphere to stratosphere transport of carbon monoxide and long-lived trace species in the Chemical Lagrangian Model of the Stratosphere (CLaMS)

2014 ◽  
Vol 7 (4) ◽  
pp. 5087-5139 ◽  
Author(s):  
R. Pommrich ◽  
R. Müller ◽  
J.-U. Grooß ◽  
P. Konopka ◽  
F. Ploeger ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Large Scale ◽  
Lower Stratosphere ◽  
Lagrangian Model ◽  
Quasi Biennial Oscillation ◽  
Data Set ◽  
Model Version ◽  
The Tropics ◽  
The Impact ◽  
Good Agreement

Abstract. Variations in the mixing ratio of trace gases of tropospheric origin entering the stratosphere in the tropics are of interest for assessing both troposphere to stratosphere transport fluxes in the tropics and the impact of these transport fluxes on the composition of the tropical lower stratosphere. Anomaly patterns of carbon monoxide (CO) and long-lived tracers in the lower tropical stratosphere allow conclusions about the rate and the variability of tropical upwelling to be drawn. Here, we present a simplified chemistry scheme for the Chemical Lagrangian Model of the Stratosphere (CLaMS) for the simulation, at comparatively low numerical cost, of CO, ozone, and long-lived trace substances (CH4, N2O, CCl3F (CFC-11), CCl2F2 (CFC-12), and CO2) in the lower tropical stratosphere. For the long-lived trace substances, the boundary conditions at the surface are prescribed based on ground-based measurements in the lowest model level. The boundary condition for CO in the free troposphere is deduced from MOPITT measurements (at &amp;approx; 700–200 hPa). Due to the lack of a specific representation of mixing and convective uplift in the troposphere in this model version, enhanced CO values, in particular those resulting from convective outflow are underestimated. However, in the tropical tropopause layer and the lower tropical stratosphere, there is relatively good agreement of simulated CO with in-situ measurements (with the exception of the TROCCINOX campaign, where CO in the simulation is biased low &amp;approx; 10–20 ppbv). Further, the model results are of sufficient quality to describe large scale anomaly patterns of CO in the lower stratosphere. In particular, the zonally averaged tropical CO anomaly patterns (the so called "tape recorder" patterns) simulated by this model version of CLaMS are in good agreement with observations. The simulations show a too rapid upwelling compared to observations as a consequence of the overestimated vertical velocities in the ERA-interim reanalysis data set. Moreover, the simulated tropical anomaly patterns of N2O are in good agreement with observations. In the simulations, anomaly patterns for CH4 and CFC-11 were found to be consistent with those of N2O; for all long-lived tracers, positive anomalies are simulated because of the enhanced tropical upwelling in the easterly phase of the quasi-biennial oscillation.

scholarly journals Investigation of unsteady combustion of methane-air flame in a model combustion chamber with swirling flow

2021 ◽  
Vol 2119 (1) ◽  
pp. 012015
Author(s):  
A S Lobasov
Keyword(s):  
Combustion Chamber ◽  
Large Scale ◽  
Recirculation Zone ◽  
Swirling Flow ◽  
Heating Temperature ◽  
Combustion Products ◽  
Flow Dynamics ◽  
Unsteady Combustion ◽  
Stereoscopic Piv ◽  
Large Scale Vortex

Abstract The present paper reports on the investigation of unsteady combustion of a methane-air mixture, including combustion at increased pressure in the combustion chamber and increased temperature of mixture heating for a model gas-turbine swirl burner based on a design by Turbomeca. To measure the velocity and OH fluorescence fields in the flows a combination of stereoscopic PIV and acetone PLIF systems is used. In all cases, the flow dynamics is associated with the movement of large-scale vortex structures in the inner and outer mixing layers and the flow structure corresponds to a swirling jet with a central recirculation zone containing combustion products. An increase in the heating temperature of the mixture and pressure in the combustion chamber leads to a periodic partial separation of the flame from the model swirl nozzle. However, the flow of fuel through the central channel will stabilize the flame.

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