scholarly journals Measurements of CFC-11, CFC-12, and HCFC-22 total columns in the atmosphere at the St. Petersburg site in 2009–2019

2020 ◽  
Author(s):  
Alexander Polyakov ◽  
Anatoly Poberovsky ◽  
Maria Makarova ◽  
Yana Virolainen ◽  
Yuri Timofeyev
Keyword(s):  
Seasonal Variability ◽  
Climate Model ◽  
Independent Data ◽  
Mean Values ◽  
Absolute Value ◽  
Qualitative And Quantitative ◽  
Observational Site ◽  
Retrieval Strategies ◽  
The Mean ◽  
The Absolute

Abstract. The retrieval strategies for deriving the atmospheric total columns (TCs) of CFC-11 (CCl3F), CFC-12 (CCl2F2), and HCFC-22 (CHClF2) from ground–based measurements of IR solar radiation have been improved. We demonstrate the advantage of using the Tikhonov-Phillips regularization approach for solving the inverse problem of the retrieval of these gases and give the optimized values of regularization parameters. The estimates of relative systematic and random errors amount to 7.61 % and 3.08 %, 2.24 % and 2.40 %, 5.75 % and 3.70 %, for CFC-11, CFC-12, and HCFC-22, respectively. We analyze the time series of the TCs and mean molar fractions (MMFs) of CFC-11, CFC-12, and HCFC-22 measured at the NDACC site St. Petersburg located near Saint Petersburg, Russia for the period of 2009–2019. Mean values of the MMFs for CFC-11, CFC-12, and HCFC-22 total 225, 493, and 238 pptv, respectively. Estimates of the MMFs trends for CFC-11, CFC-12, and HCFC-22 account for −0.40 ± 0.07 %/yr, -0.49  ±0.05 %/yr, and 2.12±0.13 %/yr, respectively. We have compared the mean values, trends and seasonal variability of CFC-11, CFC-12, and HCFC-22 MMFs measured at the St. Petersburg site in 2009–2019 to that of 1) near–ground volume mixing ratios (VMRs) measured at the observational site Mace Head, Ireland (GVMR); 2) the mean in the 8–12 km layer VMRs measured by ACE–FTS and averaged over 55–65° N latitudes (SVMR); and the MMFs of the Whole Atmosphere Community Climate Model for the St. Petersburg site (WMMF). The means of the MMFs are less than that of the GVMR for CFC-11 by 9 pptv (3.8 %), for CFC-12 by 24 pptv (4.6 %); for HCFC-22, the mean MMFs does not differ significantly from the mean GVMR. The absolute value of the trend estimates of the MMFs is less than that of the GVMR for CFC-11 (−0.40 vs −0.53 %/yr) and CFC-12 (−0.49 vs −0.59 %yr); the trend estimate of the HCFC-22 MMFs does not differ significantly from that of the GVMR. The seasonal variability of the GVMR for all three gases is much lower than the MMFs variability. The means of the MMFs are less than that of the SVMR for CFC-11 by 10 pptv (4.3 %), for CFC-12 by 33 pptv (6.3 %), and for HCFC-22 by 2 pptv (0.8 %). The absolute value of the trend estimates of the MMFs is less than that of the SVMR for CFC-11 (−0.40 vs −0.63 %/yr) and CFC-12 (−0.49 vs −0.58 %/yr); the trend estimate of the HCFC-22 MMFs does not differ significantly from that of the SVMR. The MMF and SVMR values show nearly the same qualitative and quantitative seasonal variability for all three gases. The means of the MMFs are greater than that of the WMMF for CFC-11 by 22 pptv (10 %), for CFC-12 by 15 pptv (3.1 %), and for HCFC-22 by 23 pptv (10 %). The absolute value of the trend estimates of the MMFs is less than that of the WMMF for CFC-11 (−0.40 vs −1.68 %/yr), CFC-12 (−0.49 vs −0.84 %/yr), and HCFC-22 (2.12 %/yr vs 3.40 %/yr). The MMFs and WMMF values show nearly the same qualitative and quantitative seasonal variability for CFC-11 and CFC-12, whereas the seasonal variability of the WMMF for HCFC-22 is essentially less than that of the MMFs. In general, the comparison of the MMFs with the independent data shows a good agreement of their means within the systematic error of considered measurements. The observed trends over the St. Petersburg site demonstrate the smaller decrease rates for CFC-11 and CFC-12 TCs than that of the independent data, and the same decrease rate for HCFC-22. The suggested retrieval strategies can be used for analysis of the IR solar spectra measurements using Bruker FS125HR spectrometers, e.g. at other IRWG sites of the NDACC observational network.

scholarly journals Measurements of CFC-11, CFC-12, and HCFC-22 total columns in the atmosphere at the St. Petersburg site in 2009–2019

2021 ◽  
Vol 14 (8) ◽  
pp. 5349-5368
Author(s):  
Alexander Polyakov ◽  
Anatoly Poberovsky ◽  
Maria Makarova ◽  
Yana Virolainen ◽  
Yuri Timofeyev ◽  
...  
Keyword(s):  
Climate Model ◽  
Global Scale ◽  
Atmospheric Composition ◽  
Independent Data ◽  
Mean Values ◽  
Mixing Ratios ◽  
Radiation Spectra ◽  
Observational Site ◽  
Ozone Depleting Substances ◽  
Atmospheric Concentrations

Abstract. Monitoring atmospheric anthropogenic halocarbons plays an important role in tracking their atmospheric concentrations in accordance with international agreements on emissions of ozone-depleting substances and, thus, in estimating the ozone layer recovery. Within the Network for the Detection of Atmospheric Composition Change (NDACC), regular Fourier transform infrared (FTIR) measurements can provide information on the abundancies of halocarbons on a global scale. We improved retrieval strategies for deriving the CFC-11 (CCl3F), CFC-12 (CCl2F2), and HCFC-22 (CHClF2) atmospheric columns from IR solar radiation spectra measured by the Bruker IFS125HR spectrometer at the St. Petersburg site (Russia). We used the Tikhonov–Phillips regularization approach for solving the inverse problem with optimized values of regularization parameters. We tested the strategies developed by comparison of the FTIR measurements with independent data. The analysis of the time series of column-averaged dry air mole fractions (Xgas) measured in 2009–2019 gives mean values of 225 pptv (parts per trillion by volume; CFC-11), 493 pptv (CFC-12), and 238 pptv (HCFC-22). Trend values total −0.40 % yr−1 (CFC-11), −0.49 % yr−1 (CFC-12), and 2.12 % yr−1 (HCFC-22). We compared the means, trends, and seasonal variability in XCFC-11, XCFC-12, and XHCFC-22 to that of (1) near-ground volume mixing ratios (VMRs), measured at the observational site Mace Head, Ireland (GVMR), (2) the mean in the 8–12 km layer VMRs, measured by ACE-FTS and averaged over 55–65∘ N latitudes (SVMR), and (3) Xgas values of the Whole Atmosphere Community Climate Model (WACCM) for the St. Petersburg site (WXgas). In general, the comparison of Xgas with the independent data showed a good agreement of their means within the systematic errors of the measurements considered. The trends observed over the St. Petersburg site demonstrate the smaller decrease rates for XCFC-11 and XCFC-12 than that of the independent data and the same increase rate for XHCFC-22. As a whole, Xgas, SVMR, and WXgas showed qualitatively similar seasonal variations, while the GVMR variability is significantly less, and only the WXHCFC-22 variations are essentially smaller than that of XHCFC-22 and SVMRHCFC-22.

Fitting straight lines to experimental data

1977 ◽  
Vol 233 (3) ◽  
pp. R94-R99 ◽  
Author(s):  
R. A. Brace
Keyword(s):  
Standard Error ◽  
Least Squares Regression ◽  
Simple Method ◽  
Mean Values ◽  
Absolute Value ◽  
Best Value ◽  
The Mean ◽  
Straight Lines ◽  
Relationship Of ◽  
Conventional Regression

The problem associated with use of statistical methods for determining a best linear relationship of the form Y = AX +B have been examined for a condition quite prevalent with experimental research, i.e., when the values of both variables are subject to essentially unknown errors. Under this condition standard least-squares regression analysis underestimates the value of the slope A. A very simple method for determining the best value of the slope and intercept has been introduced which can be used when errors are present in both variables. With this proposed method, the calculated slope is equal to the standard error of Y divided by the standard error of X (with the appropriate sign) and the intercept is found from the mean values of X and Y, i.e., B = Y - AX. The best estimate of the slope is also equal to the slope found with the conventional regression method divided by the absolute value of the correlation coefficient. The line determined with the suggested method can be considered to be a line of symmetry through the data.

scholarly journals Assessment of the TMJ Dysfunction Using the Computerized Facebow Analysis of Selected Parameters

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Edward Kijak ◽  
Danuta Lietz-Kijak ◽  
Bogumiła Frączak ◽  
Zbigniew Śliwiński ◽  
Jerzy Margielewicz
Keyword(s):  
Age Groups ◽  
Mouth Opening ◽  
Mean Value ◽  
Qualitative And Quantitative Analysis ◽  
Temporomandibular Joint Dysfunction ◽  
Mean Values ◽  
Qualitative And Quantitative ◽  
Maximum Value ◽  
Function Test ◽  
The Mean

The Purpose of the Paper.Qualitative and quantitative analysis of selected parameters of mandible movements, electronically registered in patients with temporomandibular joint dysfunction and healthy ones.Material. Function test of the mandible movements was conducted in 175 patients. Gender distribution was 143 women and 32 men, aged 9 to 84.Methods. The studied population, after accurate clinical examination, was divided into age groups with the range of five years. All the patients had Zebris JMA computerized facebow examination done, according to the generally accepted principles and procedures.Results.Mean values of mouth opening calculated to 45.6 mm in healthy group and 37.6 mm in TMJ dysfunction group. Mean length of condylar path amounted to39±7% of the maximum value of mouth opening in the group of healthy people,44±11% in the case of muscle-based disorders, and35±11% with joint-based. The mean value of the condylar path inclination oscillated in the range of 25° to 45°.Conclusions. The ratio of length of the condylar path to the size of mouth opening may be a significant value characterising the type and degree of intensification of the TMJ dysfunctions.

Physiological roles of thyrotrophin-releasing hormone and vasoactive intestinal peptide on the pulsatile secretory patterns of prolactin in pituitary-grafted female rats

1994 ◽  
Vol 142 (3) ◽  
pp. 581-586 ◽  
Author(s):  
A Lafuente ◽  
J Marcó ◽  
A I Esquifino
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Prolactin Secretion ◽  
Female Rats ◽  
Thyrotrophin Releasing Hormone ◽  
Mean Values ◽  
Pulsatile Secretion ◽  
Releasing Hormone ◽  
Absolute Amplitude ◽  
The Mean ◽  
The Absolute

Abstract Much is known about the fact that thyrotrophin-releasing hormone (TRH) and vasoactive intestinal peptide (VIP) stimulate prolactin secretion but areas of uncertainty remain. This work was undertaken to describe the effects of TRH and VIP on the pulsatile secretion pattern of prolactin, in adult sham-operated and pituitary-grafted hyperprolactinaemic female rats. Two pulses of TRH (1 μg/rat) or one pulse of VIP (20 μg/rat) were given 60 or 120 min after the period of blood sampling. Pituitary grafting increased the mean values of prolactin, absolute amplitude and duration of the peaks and decreased their frequency, compared with control animals. In sham-operated rats, TRH elevated prolactin levels by increasing the absolute and relative amplitudes and duration of the pulses, along with a decrease in their frequency. No priming effects of TRH were observed in this study. Hyperprolactinaemia blunted TRH effects on the pulsatile secretion pattern of prolactin. In sham-operated rats, VIP administration increased the absolute and relative amplitudes of the prolactin peaks. None of the other parameters studied were changed. In pituitary-grafted animals, VIP administration increased the absolute and relative amplitudes of the prolactin peaks but to a lesser extent compared with controls. These data suggest that TRH and VIP affect prolactin pulsatility differentially. The effects of TRH and VIP were blunted to some extent by exposure to previously elevated circulating prolactin levels. Journal of Endocrinology (1994) 142, 581–586

scholarly journals The Heritability of Some Qualitative and Quantitative Traits at One Set of Spring Barley Genotypes

2018 ◽  
Vol 75 (2) ◽  
pp. 93-100
Author(s):  
Ioana PORUMB ◽  
Florin RUSSU ◽  
Ioan ROTAR
Keyword(s):  
Quantitative Traits ◽  
Starch Content ◽  
Spring Barley ◽  
Mean Values ◽  
Qualitative And Quantitative ◽  
Chemical Trait ◽  
The Subject ◽  
The Mean ◽  
Barley Genotypes ◽  
Collection Level

Work collections are subjected to a renewal process, therefore a regular evaluation is needed inorder to appreciate the genetic advance of the existing variability at collection level and further to identify valuable genotypes in terms of morphoproductive and qualitative traits (protein, starch). The barley intended for brewing must correspond to some qualitative parameters, of which proteins and starch content are of major importance. For this purpose, a study was conducted to assess the variability and heritability indicators corresponding to the two traits at 48 barley genotypes. The genotypes that were the subject of this study were sown in three experimental years 2013, 2014 and 2016. The mean values of 2013 year was 13.71 compared with only 10.77, and 11.27 in 2014 and 2016. The significant value of the heritability coefficient along with the genetic advantage of 0.81 indicates the success of selection work for this important chemical trait.

Asymptotic Analysis of Wave Resistance of a Submerged Body Moving with an Oscillating Velocity

1993 ◽  
Vol 37 (02) ◽  
pp. 119-125
Author(s):  
N. G. Kuznetsov
Keyword(s):  
Perturbation Technique ◽  
Mean Value ◽  
Wave Resistance ◽  
The Body ◽  
Singular Perturbation Technique ◽  
Mean Values ◽  
Absolute Value ◽  
Submerged Body ◽  
Short Period ◽  
The Mean

An asymptotic study is made of potential and tree-surface elevation due to forward motion of a submerged body with an oscillating velocity. The latter is supposed to be a short period. As the nondimensional period ε 1, the singular perturbation technique is applied. Using two-term expansion for the potential, the principal terms of asymptotics for instant and mean values of wave resistance are obtained. The mean value (up to a term 0(e)) is the sum of two addends, the first of which is the wave resistance of the same body moving at the mean speed. The second addend is proportional to the dispersion of velocity with the coefficient depending on the form of the body. This coefficient vanishes if the body is symmetric with respect to the mid-section. Numerical examples for the two-dimensional problem show that there exist cylinders with the following property: the absolute value of wave resistance decreases when passing from motion at the mean speed to motion with oscillating velocity.

scholarly journals Size and Charge Stability of Oil Bodies from Peanut

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lihua Hao ◽  
Fusheng Chen ◽  
Yimiao Xia ◽  
Lifen Zhang ◽  
Ying Xin
Keyword(s):  
Salt Concentration ◽  
Aqueous Extraction ◽  
Diameter Distribution ◽  
Oil Bodies ◽  
Absolute Value ◽  
Mean Diameter ◽  
Median Diameter ◽  
Charge Stability ◽  
The Mean ◽  
The Absolute

In order to offer scientific bases for the application of oil bodies from peanut in food, this research was undertaken to study the size and charge stability of oil bodies from five peanut varieties. It showed that the mean diameter of oil bodies fromyuhua9719andyuhua9830is obviously larger thanyuhua23,yuhua27, andyuhua9502in the peanut cell. Moreover, the analysis of diameter distribution of oil bodies also showed that the median diameter of oil bodies increased dramatically in the order ofyuhua9719>yuhua9830>yuhua23>yuhua27>yuhua9502after aqueous extraction. The charge stability of oil bodies from peanut was observed with zeta (ζ) potential measurements, which indicated that charge properties and the absolute value of oil bodies from five peanut varieties were significantly affected by pH and salt concentration, but the degree of influence is different. Of the five peanut varieties,yuhua27andyuhua9830possessed excellent charge stability (ζ-potential>35 mV) in neutral microenvironment without salt concentration.

scholarly journals Analysis of Thermodynamic Parameter Variability in a Chamber of a Furnace for Thermo-Chemical Treatment

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2903
Author(s):  
Magda Joachimiak
Keyword(s):  
Boundary Conditions ◽  
Chemical Treatment ◽  
Mean Value ◽  
Mean Values ◽  
Cylinder Length ◽  
Unsteady Heat Conduction ◽  
The Mean ◽  
The Absolute ◽  
The Difference ◽  
Relative Differences

This paper presents results of research on unevenness of cylinder heating in a furnace for thermo-chemical treatment. Experimental research was conducted with respect to nitriding. Various heating speeds and settings of the fan operation in the furnace were considered. Boundary conditions were calculated in the form of temperature and the heat transfer coefficient (HTC) on the cylinder boundary in four planes along the cylinder length. Calculations were performed with the use of the inverse problem for non-linear and unsteady heat conduction equations. Boundary conditions from individual planes were compared with the mean value of them all. The variability of the calculated boundary conditions (temperature and HTC) along the cylinder length was investigated based on values of the absolute and relative differences for temperature and HTC. Estimates: mean value, mean value from the absolute value and the maximum values for the absolute and the relative differences of temperature and HTC were also calculated. Estimates were the measurements of the unevenness of cylinder heating in a furnace for thermo-chemical treatment. Based on the results of our research, it was found that an increase of the fan rotational speed from 50% to 100%, with the same heating speed, resulted in a significant leveling of temperature in the analyzed planes. The difference in temperature along the cylinder length was reduced from 6.8 °C to 3.3 °C. The increase of the heating speed from 5 °C/min to 10 °C/min resulted in an increase of the unevenness of the cylinder heating. Values of the absolute differences of temperature in the analyzed planes with reference to the mean temperature changed from an interval from −2.7 °C to 2.3 °C to a range from −4 °C to 5 °C. In processes with a heating speed greater than 5 °C/min, more intensive heating in the end part of the cylinder (close to the cylinder) was achieved than it was in other planes. It was proven by temperature values, which were higher, even, by 5.4 °C, and by HTC values, higher by 11.4 W/m2K, when compared with mean values. Obtained results can form the basis for nitriding process optimization.

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