Top PDF Characteristics of tropospheric ozone depletion events in the Arctic spring: analysis of the ARCTAS, ARCPAC, and ARCIONS measurements and satellite BrO observations

Characteristics of tropospheric ozone depletion events in the Arctic spring: analysis of the ARCTAS, ARCPAC, and ARCIONS measurements and satellite BrO observations

Characteristics of tropospheric ozone depletion events in the Arctic spring: analysis of the ARCTAS, ARCPAC, and ARCIONS measurements and satellite BrO observations

Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D., Gandin, L., Iredell, M., Saha, S., White, G., Woollen, J., Zhu, Y., Chelliah, M., Ebisuzaki, W., Higgins, W., Janowiak, J., Mo, K. C., Ropelewski, C., Wang, J., Leetmaa, A., Reynolds, R., Jenne, R., and Joseph, D.: The NCEP/NCAR 40-year reanalysis project, Bull. Am. Meteorol. Soc., 77, 437–471, 1996. Kaleschke, L., Richter, A., Burrows, J., Afe, O., Heygster, G., Notholt, J., Rankin, A. M.,

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Source attribution and interannual variability of Arctic pollution in spring constrained by aircraft (ARCTAS, ARCPAC) and satellite (AIRS) observations of carbon monoxide

Source attribution and interannual variability of Arctic pollution in spring constrained by aircraft (ARCTAS, ARCPAC) and satellite (AIRS) observations of carbon monoxide

The Arctic is a major receptor for mid-latitudes pollution (Shaw, 1995; Quinn et al., 2007). Radiative forcing by pollu- tants in the Arctic including ozone, aerosols, and black car- bon deposited on snow could make a major contribution to regional and global warming (Koch and Hansen, 2005; Shin- dell et al., 2006a; McConnell et al., 2007; Quinn et al., 2008; Shindell and Faluvegi, 2009). Several studies have identi- fied pollution transport pathways to the Arctic on the basis of model simulations and meteorological analyses (Eckhardt et al., 2003; Klonecki et al., 2003; Koch and Hansen, 2005; Stohl, 2006; Shindell et al., 2008), but our ability to ver- ify these pathways through chemical observations has been limited. Polar-orbiting satellites offer unique platforms for this purpose. We present here an analysis of the sources and transport of Arctic pollution in spring using the GEOS-Chem chemical transport model (CTM) to interpret satellite obser- vations of carbon monoxide (CO) from the Atmospheric In- fraRed Sounder (AIRS) together with aircraft measurements from the NASA ARCTAS (Arctic Research of the Compo- sition of the Troposphere from Aircraft and Satellites) and NOAA ARCPAC (Aerosol, Radiation, and Cloud Processes affecting Arctic Climate) campaigns.
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Vertical structure of Antarctic tropospheric ozone depletion events: characteristics and broader implications

Vertical structure of Antarctic tropospheric ozone depletion events: characteristics and broader implications

Abstract. The majority of tropospheric ozone depletion event (ODE) studies have focussed on time-series measure- ments, with comparatively few studies of the vertical com- ponent. Those that exist have almost exclusively used free- flying balloon-borne ozonesondes and almost all have been conducted in the Arctic. Here we use measurements from two separate Antarctic field experiments to examine the ver- tical profile of ozone during Antarctic ODEs. We use tether- sonde data to probe details in the lowest few hundred me- ters and find considerable structure in the profiles associ- ated with complex atmospheric layering. The profiles were all measured at wind speeds less than 7 ms −1 , and on each occasion the lowest inversion height lay between 10 m and 40 m. We also use data from a free-flying ozonesonde study to select events where ozone depletion was recorded at alti- tudes >1 km above ground level. Using ERA-40 meteoro- logical charts, we find that on every occasion the high alti- tude depletion was preceded by an atmospheric low pressure system. An examination of limited published ozonesonde data from other Antarctic stations shows this to be a con- sistent feature. Given the link between BrO and ODEs, we also examine ground-based and satellite BrO measurements and find a strong association between atmospheric low pres- sure systems and enhanced BrO that must arise in the tropo- sphere. The results suggest that, in Antarctica, such depres- sions are responsible for driving high altitude ODEs and for generating the large-scale BrO clouds observed from satel- lites. In the Arctic, the prevailing meteorology differs from
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Analysis of satellite-derived Arctic tropospheric BrO columns in conjunction with aircraft measurements during ARCTAS and ARCPAC

Analysis of satellite-derived Arctic tropospheric BrO columns in conjunction with aircraft measurements during ARCTAS and ARCPAC

stronger for a partial ozone depletion event (ODE) than a major ODE. Tropospheric column BrO from OMI does show an enhancement, near Alert, 36 h prior to the major ODE. The aircraft may have been capturing very small scale variability (several nearby profiles showed large differences) compared to space-based observations. Finally, air- craft observations generally did not sample the altitude region where stratosphere to

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The influence of the arc plasma treatment on the structure and microhardness C120U carbon tool steel

The influence of the arc plasma treatment on the structure and microhardness C120U carbon tool steel

The material used in this study was C120U steel. Chemical composition of this steel is presented in Table 1. Specimens as cuboids about dimensions 7,5 x 30 x 30 mm were conventional hardened (temperature austenitization – 770 o C, quenching in oil) and tempered (in temperature 250 o C). Temperatures hardening and tempering were chosen on the basis EN ISO 4957:1999 norms to obtain a structure with a relatively high toughness. Remelting surface was carried out using gas tungsten arc welding method. The surface of the samples were remelted by means of
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Satellite observations of long range transport of a large BrO cloud in the Arctic

Satellite observations of long range transport of a large BrO cloud in the Arctic

time and should vanish quickly from the atmosphere by consecutive reactions. Ground- based observations of ODEs are often limited to a few hours. However, BrO plumes can be observed in satellite data for many days and over large areas, indicating addi- tional chemical mechanisms and the transport of the involved air masses. To date it is not clear whether these large-scale plumes indicate continuous generation of BrO

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Fields of study and the earnings gap by race in Brazil

Fields of study and the earnings gap by race in Brazil

The detailed questionnaire of the Census provides individual information about education, age, gender, race, employment status, labor earnings and occupation in the main job, and place of residence, among many other variables. Based on the information about race, which is self-reported, the sample is divided into white and black workers, where individuals who reported themselves as black or colored are included in the latter group. Asian and indigenous are excluded. For individuals who completed tertiary education, the Census has information about their fields of study. However, the classification system in 2000 is not the same as that in 2010. The appendix A describes how codes from different Census years are matched in this paper. As also shown in the appendix, the detailed categories for fields of study are aggregated into 10 broader groups, which are used in most of the analysis presented here. The Census questionnaire also allows identifying whether an individual has a graduate degree, although the 2000 survey does not distinguish between master ’s and doctoral degrees. In both periods, fields of study refer to the individuals’ highest degrees.
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White and gray solidification of the Fe-C eutectic

White and gray solidification of the Fe-C eutectic

This means that branching of graphite, which is needed for growth at the optimum-lamellar spacing, is difficult. The lamella of graphite will then grow straight in a converging or diverging way, leading to a whole range of lamellar spacing (corresponding to a range of undercooling given by eq. (1)). It has been shown that growth cannot be achieved with a spacing lower than the extreme one. Growth of converging lamella will then stop when this spacing is reached. At the opposite, growth of diverging lamella will be stable only as long as is less than a critical spacing br where branching occurs, as shown in fig. 3.
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Synthesis Of Arts In Architecture Of Uzbekistan Of The Ancient Period

Synthesis Of Arts In Architecture Of Uzbekistan Of The Ancient Period

was based on plastic contrast. For example, to emphasize the central part among the other composition, the architect 'in the middle third of the main wall had arranged an extensive (5.60 m) but shallow (75 cm) niche‖ [16, 46p]. The building itself was small in scale, and to emphasize its monumentality and visually to expand its interior, the sculptors correlated the height of zofor (1.40 m) to 6-meter span of the building. Frieze made with account of the angle of perspective, was decorated with garlands, supported by frames of children. The images of the frieze were original in the "very understanding of the ideal of human beauty and its artistic expression in plastic forms" [44, 61p]. Often in these images there was observed a deliberate asymmetry (in the faces), the disproportion (in the figures), aimed to correct the visual angle. For the sculpture in Toprak-kala "a rhythmic repetition of similar sculptural groups, determining architectonic division of interior, was characteristic" [45]. The style and the manner of sculpture, for example, of friezes were the same as of acanthus, volutes. So, it can be assumed that the ancient sculptors have been actively involved not only in the development of sculptures, but in architectural and decorative compositions (especially of capitals), and the connection between the latters was very tight. In general, the nature of decoration of the premises depended on the functions of the latter: "household and service rooms were modestly furnished, as for residential and ceremonial rooms they were finished with the appropriate splendor‖ [46, 67p]. The sculpture, obeying the architecture, served as an element of its design. In Bactria a monumental sculpture "was designed primarily to be installed in the temples" [22, 901p]. In architectural
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Influence of tungsten and titanium on the structure of chromium cast iron

Influence of tungsten and titanium on the structure of chromium cast iron

Studies were conducted using a T-01M Tester with a ball-on- disc system, designed to evaluate the tribological properties of materials used for parts of machinery and equipment constituting the friction pairs. With this device it is possible to determine the wear resistance and friction coefficient of the material in sliding pairs, depending on the sliding velocity, surface pressure, presence and type of lubricant, contamination and other factors. The study was conducted in accordance with the methods set out in the ASTM G99 and DIN 50324 standards.
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Human Capital and the Recent Fall of Earnings Inequality in Brazil

Human Capital and the Recent Fall of Earnings Inequality in Brazil

Brazil has the world’s eighth largest economy (IMF, 2008). Nevertheless, 21.4 % of the country’s people live in poverty, and 7.3% in misery (IPEADATA, 2009). This contradiction is the result of the country’s glaring income inequality (UNDP, 2010) 1 . But, after decades remaining at a very high and stable level, inequality has recently started to decline in Brazil and in several other Latin- American countries (Lopez-Calva and Lustig, 2010). The aim of this paper is to understand the reasons behind the fall of the Brazilian inequality, using a flexible econometric approach and focusing on the role played by education and age.
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Determinants and Consequences of   the Website Perceived Value

Determinants and Consequences of the Website Perceived Value

rich in value. Experiential value perceptions are based upon interactions involving either direct usage or distanced appreciation of goods and services. These interactions provide the basis for relativistic preferences held by the individual involved (Holbrook and Coffman, 1995). These preferences may be intrinsic_when the experience helps the shopper to realize some of his purposes_ or extrinsic when the experience is enjoyed for its own sake (Babin and Darden, 1995; Batra and Ahtola, 1991). Besides, they may be experienced as the consequence of active (the consumer assumes the role of co- producer) or reactive (that occurs when the individual simply apprehends, appreciate, or responds to an object) interactions with the product/service. The following experiential value matrix developed by Malhotra et al (2001) represents an integration of the intrinsic/extrinsic and active/reactive dimensions.
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Explicit and implicit approach of sensitivity analysis in numerical modelling of solidification

Explicit and implicit approach of sensitivity analysis in numerical modelling of solidification

Keywords: Application of Information Technology to the Foundry Industry: Solidification Process: Numerical Tcchniqucs: Sensitivity Analysis; Borzndary Elcmcnt Mcthod.. Introd[r]

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The quality of castings obtained during lost-wax and Replicast CS processes in aspect of ecology

The quality of castings obtained during lost-wax and Replicast CS processes in aspect of ecology

Haratym, Dok ł adno ć wymiarowa odlewów wykona- nych w procesie Replicast CS, Archiwum Odlewnictwa rocznik 3, nr 9, Katowice 2003.. Arendarski, Niepewno ć pomiarów, Oficyna Wydaw- nic[r]

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Buying Behavior Of Organic Vegetables Product The Effects Of Perceptions Of Quality And Risk

Buying Behavior Of Organic Vegetables Product The Effects Of Perceptions Of Quality And Risk

Quality is defined as the degree of excellence or superiority that an organization’s product possesses (Khan, 2005:28). Consumers judge or perceive the quality of the products and it also called perception of quality, because perception of quality derived from the analysis of consumers on product quality (Sanyal & Datta, 2011:605). Customer perceived value of product quality is a consumer opinion as ability of the product who suitable with expectation of consumer (Terenggana et al., 2013:326). Perception of quality is formed on consumers can be affected by several things including past experience, education, purchasing and consumer community (Yaseen et al., 2011:834), and perception of quality is important in improving the quality of products in the view of consumers (Parrol et al., 2013:603). Since knowledge and consumer needs change time by time, it taken an understanding related consumer perception of quality in evaluated to be known how big influence on purchase intention (Sanyal & Datta, 2011:607). Reviewing consumer behavior in foods, in previous research is often studied through perception of quality (Carrasco et al., 2012:1414). On last studied, perceived quality is the consumer’s judgment about a product’s overall excellence or superiority (Zeithaml, 1988). Meanwhile perceived quality is the judgment a consumer of product which refers to the physical characteristics of the product, and is related more to engineering and food technology (Carrasco et al., 2012). Several things that concern on perception of quality, first are spoke on the advantages related to the assessment of consumer products and the second on the technology applied to products that are both better than similar products. That matter is a critical element for consumer decision making, consequently, consumers will compare the
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Vortex-averaged Arctic ozone depletion in the winter 2002/2003

Vortex-averaged Arctic ozone depletion in the winter 2002/2003

Schauffler, S. M., Atlas, E. L., Herman, R. L., Webster, C. R., Bui, T. P., Moore, F. L., Ray, E. A., Oltmans, S. J., V ¨omel, H., Blavier, J.-F., Sen, B., Stachnik, R. A., Toon, G. C., Engel, A., M ¨uller, M., Schmidt, U., Bremer, H., Pierce, R. B., Sinnhuber, B.-M., Chipperfield, M., and Lef `evre, F.: Tracer-based determination of vortex descent in the 1999/2000 Arctic win- ter, J. Geophys. Res., 107, doi:10.1029/2001JD000937, (Erratum: J. Geophys. Res., 108,

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Evaluation And Characterization Of Trace Metals Contamination In The Surface Sediment Using Pollution Load Index PLI And Geo-Accumulation Index Igeo Of Ona River Western Nigeria

Evaluation And Characterization Of Trace Metals Contamination In The Surface Sediment Using Pollution Load Index PLI And Geo-Accumulation Index Igeo Of Ona River Western Nigeria

Table 1 shows the summary of the mean concentrations for the metals of sediments at the study stations, Table 2 shows the Calculated F-values of one way analysis of variance measured in Ona River and Table 3. Summary of Pollution Load Index (PLI) and Geo-accumulation Index (Igeo) on Sediment Quality of Ona River. The heavy metals determined in this study include lead, chromium, iron and copper. Spatial variations in their mean values are shown in Figure 3. The mean values of lead ranged between 0.004 mg/kg and 0.330 mg/kg, while the mean iron was highest (5.05 mg/kg) in station 4 and lowest (2.26 mg/kg) in station 5. The mean chromium value ranged from 0.007 mg/kg (station 1 and 2) to 0.021 mg/kg (station 3 and 4). The mean copper was highest (3.97 mg/kg) in station 1 and lowest (0.008 mg/kg) in station 2. Analysis of variance (ANOVA) revealed the same trend in spatial variation of these heavy metals (Table 2). There was a significant difference (P< 0.05) in lead, chromium and copper among the study sampling stations and insignificant difference (P>0.05) in iron among the study sampling station (Table 2).
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Impact of sampling frequency in the analysis of tropospheric ozone observations

Impact of sampling frequency in the analysis of tropospheric ozone observations

Surface stations give the lowest uncertainty in the slope due to their large amount of data. Most of them suggest a positive trend in all seasons, except in summer when trends are more scattered around zero. The seasonal trends vary with the altitude of the stations (not shown). Above 1 km, the results suggest a negative trend in summer, positive in winter and spring and a near-zero trend during the fall season, in agreement

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Analysis of quality and cost of FeSiMg treatment master alloy vs. cored wire in production of ductile cast iron

Analysis of quality and cost of FeSiMg treatment master alloy vs. cored wire in production of ductile cast iron

The results of studies on the use of FeSi5%Mg magnesium alloy in modern cored wire injection method for production of nodular and vermicular graphite cast irons were described. The injection of Mg cored wire length is a treatment method which can be used to process The injection of Mg cored wire length is a treatment method which can be used to process iron melted in an electric induction furnace. This paper describes the results of using a high-magnesium ferrosilicon alloy in cored wire (Mg recovery 47-70%) for the production of vermicular and nodular graphite cast irons at in at least 13 foundries. The results of calculations and experiments have indicated the length of the cored wire to be injected basing on the initial sulfur content and weight of the treated melt. The results of numerous trials have shown that the magnesium cored wire process can produce high quality nodular and vermicular graphite irons under the specific industrial conditions of the above mentioned foundries. It has also been proved that in the manufacture of nodular graphite iron, the cost of the nodulariser in the form of elastic cored wire is lower than the cost of the FeSiMg5 master alloys.
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Assessment Of Some Acceleration Schemes In The Solution Of Systems Of Linear Equations.

Assessment Of Some Acceleration Schemes In The Solution Of Systems Of Linear Equations.

Many practical problems can be reduced to systems of linear equations Ax = b, where A, b are known matrices and x is a vector of unknowns. Systems of linear equations play a prominent role in economics, engineering, physics, chemistry, computer science and other fields of Pure and Applied Sciences [2]. A solution to a system of linear equations is a set of numerical values ….. that satisfies all the equations in a system [1]. There are two classes of iterative methods [3]: linear stationary and linear nonstationary. The stationary iterative methods are the Jacobi, Gauss-Seidel and SOR and Nonstationary include Krylov subspace methods: Conjugate Gradient, Minimal Residual, Quasi-Minimal Residual, Generalizes Minimal Residual and Biconjugate gradient methods. The choice of a method for solving linear systems will often depend on the structure of the matrix A. According to [8] ideally, iterative methods should have the property that for any starting vector , it converges to a solution Ax = b. [5] is of the view that examination of the Jacobi iterative method shows that in general one must save all the components of the vector while computing the components of the vector for an iterative method. According to Hadjidimos [6], the first step in the construction of solution of stationary iterative methods usually begins with splitting of matrix A. Thus, A = M – N where det M and M is easily invertible so that A = b is equivalent to = T + C , where T = and C = giving the iterative scheme = T + C , (k = 0,1,2……). [2] noted that for systems of linear equation A the splitting matrix may be chosen in a different way; that is, one can split matrix A as A = D L U where D is the diagonal matrix, L and U are strictly lower and strictly upper triangular matrices respectively. In solving the systems of linear equations Ax = b, therefore, we consider any convergent method which produces a sequence of iterates { [7] .Quite often the convergence is too slow and it has to be accelerated. According to [9] to improve the convergence rate of the basic iterative methods, one may transform the original system A = b into the preconditioned form PA = Pb, where � is called the preconditioned or a preconditioning matrix. Convergent numerical sequences occur quite often in natural Science and Engineering. Some of such sequences converge very slowly and their limits are not available without suitable convergent acceleration method. Some known acceleration schemes are: Chebyshev Extrapolation scheme [4] and residual Smoothing.
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