scholarly journals Novel estimation of aerosol processes with particle size distribution measurements: a case study with TOMAS algorithm

2020 ◽  
Author(s):  
Dana L. McGuffin ◽  
Yuanlong Huang ◽  
Richard C. Flagan ◽  
Tuukka Petäjä ◽  
B. Erik Ydstie ◽  
...  
Keyword(s):  
Size Distribution ◽  
Growth Rates ◽  
Measurement Bias ◽  
Size Distributions ◽  
Inverse Technique ◽  
Microphysical Processes ◽  
Aerosol Emissions ◽  
Model Measurement ◽  
Aerosol Properties

Abstract. Atmospheric aerosol microphysical processes are a significant source of uncertainty in predicting climate change. Specifically, aerosol nucleation, emissions, and growth rates, which are simulated in chemical transport models to predict the particle size distribution, are not understood well. However, long-term size distribution measurements made at several ground-based sites across Europe implicitly contain information about the processes that created those size distributions. This work aims to extract that information by developing and applying an inverse technique to constrain aerosol emissions as well as nucleation and growth rates based on hourly size distribution measurements. We developed an inverse method based upon process control theory into an online estimation technique to scale aerosol emissions, growth, and nucleation so that the model-measurement bias in three measured aerosol properties exponentially decays. The properties, which are calculated from the measured and predicted size distributions, used to constrain aerosol nucleation, emission, and growth rates are the number of particles with diameter between 3 nm and 6 nm, the number with diameter greater than 10 nm, and the total dry volume of aerosol (N3-6, N10, Vdry), respectively. In this paper, we focus on developing and applying the estimation methodology in a zero-dimensional "box" model as a proof-of-concept before applying it to a three-dimensional simulation in subsequent work. The methodology is first tested on a dataset of synthetic and perfect measurements that span diverse environments in which the true particle emissions, growth, and nucleation rates are known. The inverse technique accurately estimates the aerosol microphysical process rates with an average and maximum error of 2 % and 13 %, respectively. Next, we investigate the effect that measurement noise has on the estimated rates. The method is robust to typical instrument noise in the aerosol properties as there is a negligible increase in bias of the estimated process rates. Finally, the methodology is applied to long-term datasets of in-situ size distribution measurements in Western Europe from May 2006 through June 2007. At Melpitz, Germany and Hyytiälä, Finland, the average diurnal profiles of estimated 3 nm particle formation rates are reasonable, having peaks near noon local time with average peak values of 1 and 0.15 cm−3 s−1, respectively. The normalized absolute error in estimated N3-6, N10, and Vdry at three European measurement sites is less than 15 %, showing that the estimation framework developed here has potential to decrease model-measurement bias while constraining uncertain aerosol microphysical processes.

scholarly journals Novel estimation of aerosol processes with particle size distribution measurements: a case study with the TOMAS algorithm v1.0.0

2021 ◽  
Vol 14 (3) ◽  
pp. 1821-1839
Author(s):  
Dana L. McGuffin ◽  
Yuanlong Huang ◽  
Richard C. Flagan ◽  
Tuukka Petäjä ◽  
B. Erik Ydstie ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Growth Rates ◽  
Measurement Bias ◽  
Size Distributions ◽  
Inverse Technique ◽  
Microphysical Processes ◽  
Model Measurement ◽  
Aerosol Properties

Abstract. Atmospheric aerosol microphysical processes are a significant source of uncertainty in predicting climate change. Specifically, aerosol nucleation, emissions, and growth rates, which are simulated in chemical transport models to predict the particle size distribution, are not understood well. However, long-term size distribution measurements made at several ground-based sites across Europe implicitly contain information about the processes that created those size distributions. This work aims to extract that information by developing and applying an inverse technique to constrain aerosol emissions as well as nucleation and growth rates based on hourly size distribution measurements. We developed an inverse method based upon process control theory into an online estimation technique to scale aerosol nucleation, emissions, and growth so that the model–measurement bias in three measured aerosol properties exponentially decays. The properties, which are calculated from the measured and predicted size distributions, used to constrain aerosol nucleation, emission, and growth rates are the number of particles with a diameter between 3 and 6 nm, the number with a diameter greater than 10 nm, and the total dry volume of aerosol (N3–6, N10, Vdry), respectively. In this paper, we focus on developing and applying the estimation methodology in a zero-dimensional “box” model as a proof of concept before applying it to a three-dimensional simulation in subsequent work. The methodology is first tested on a dataset of synthetic and perfect measurements that span diverse environments in which the true particle emissions, growth, and nucleation rates are known. The inverse technique accurately estimates the aerosol microphysical process rates with an average and maximum error of 2 % and 13 %, respectively. Next, we investigate the effect that measurement noise has on the estimated rates. The method is robust to typical instrument noise in the aerosol properties as there is a negligible increase in the bias of the estimated process rates. Finally, the methodology is applied to long-term datasets of in situ size distribution measurements in western Europe from May 2006 through June 2007. At Melpitz, Germany, and Hyytiälä, Finland, the average diurnal profiles of estimated 3 nm particle formation rates are reasonable, having peaks near noon local time with average peak values of 1 and 0.15 cm−3 s−1, respectively. The normalized absolute error in estimated N3–6, N10, and Vdry at three European measurement sites is less than 15 %, showing that the estimation framework developed here has potential to decrease model–measurement bias while constraining uncertain aerosol microphysical processes.

scholarly journals Long-term cloud condensation nuclei number concentration, particle number size distribution and chemical composition measurements at regionally representative observatories

2018 ◽  
Vol 18 (4) ◽  
pp. 2853-2881 ◽  
Author(s):  
Julia Schmale ◽  
Silvia Henning ◽  
Stefano Decesari ◽  
Bas Henzing ◽  
Helmi Keskinen ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Size Distribution ◽  
Radiative Forcing ◽  
Particle Number ◽  
Cloud Condensation Nuclei ◽  
Number Concentration ◽  
Size Distributions ◽  
Number Size Distribution ◽  
Particle Number Size Distribution

Abstract. Aerosol–cloud interactions (ACI) constitute the single largest uncertainty in anthropogenic radiative forcing. To reduce the uncertainties and gain more confidence in the simulation of ACI, models need to be evaluated against observations, in particular against measurements of cloud condensation nuclei (CCN). Here we present a data set – ready to be used for model validation – of long-term observations of CCN number concentrations, particle number size distributions and chemical composition from 12 sites on 3 continents. Studied environments include coastal background, rural background, alpine sites, remote forests and an urban surrounding. Expectedly, CCN characteristics are highly variable across site categories. However, they also vary within them, most strongly in the coastal background group, where CCN number concentrations can vary by up to a factor of 30 within one season. In terms of particle activation behaviour, most continental stations exhibit very similar activation ratios (relative to particles > 20 nm) across the range of 0.1 to 1.0 % supersaturation. At the coastal sites the transition from particles being CCN inactive to becoming CCN active occurs over a wider range of the supersaturation spectrum. Several stations show strong seasonal cycles of CCN number concentrations and particle number size distributions, e.g. at Barrow (Arctic haze in spring), at the alpine stations (stronger influence of polluted boundary layer air masses in summer), the rain forest (wet and dry season) or Finokalia (wildfire influence in autumn). The rural background and urban sites exhibit relatively little variability throughout the year, while short-term variability can be high especially at the urban site. The average hygroscopicity parameter, κ, calculated from the chemical composition of submicron particles was highest at the coastal site of Mace Head (0.6) and lowest at the rain forest station ATTO (0.2–0.3). We performed closure studies based on κ–Köhler theory to predict CCN number concentrations. The ratio of predicted to measured CCN concentrations is between 0.87 and 1.4 for five different types of κ. The temporal variability is also well captured, with Pearson correlation coefficients exceeding 0.87. Information on CCN number concentrations at many locations is important to better characterise ACI and their radiative forcing. But long-term comprehensive aerosol particle characterisations are labour intensive and costly. Hence, we recommend operating “migrating-CCNCs” to conduct collocated CCN number concentration and particle number size distribution measurements at individual locations throughout one year at least to derive a seasonally resolved hygroscopicity parameter. This way, CCN number concentrations can only be calculated based on continued particle number size distribution information and greater spatial coverage of long-term measurements can be achieved.

scholarly journals Particle mobility size spectrometers: harmonization of technical standards and data structure to facilitate high quality long-term observations of atmospheric particle number size distributions

2010 ◽  
Vol 3 (6) ◽  
pp. 5521-5587 ◽  
Author(s):  
A. Wiedensohler ◽  
W. Birmili ◽  
A. Nowak ◽  
A. Sonntag ◽  
K. Weinhold ◽  
...  
Keyword(s):  
Data Structure ◽  
Size Distribution ◽  
Atmospheric Aerosol ◽  
Size Distributions ◽  
Atmospheric Measurements ◽  
Differential Mobility ◽  
Technical Standards ◽  
Raw Data ◽  
Particle Mobility

Abstract. Particle mobility size spectrometers often referred to as DMPS (Differential Mobility Particle Sizers) or SMPS (Scanning Mobility Particle Sizers) have found a wide application in atmospheric aerosol research. However, comparability of measurements conducted world-wide is hampered by lack of generally accepted technical standards with respect to the instrumental set-up, measurement mode, data evaluation as well as quality control. This article results from several instrument intercomparison workshops conducted within the European infrastructure project EUSAAR (European Supersites for Atmospheric Aerosol Research). Under controlled laboratory conditions, the number size distribution from 20 to 200 nm determined by mobility size spectrometers of different design are within an uncertainty range of ±10% after correcting internal particle losses, while below and above this size range the discrepancies increased. Instruments with identical design agreed within ±3% in the peak number concentration when all settings were done carefully. Technical standards were developed for a minimum requirement of mobility size spectrometry for atmospheric aerosol measurements. Technical recommendations are given for atmospheric measurements including continuous monitoring of flow rates, temperature, pressure, and relative humidity for the sheath and sample air in the differential mobility analyser. In cooperation with EMEP (European Monitoring and Evaluation Program), a new uniform data structure was introduced for saving and disseminating the data within EMEP. This structure contains three levels: raw data, processed data, and final particle size distributions. Importantly, we recommend reporting raw measurements including all relevant instrument parameters as well as a complete documentation on all data transformation and correction steps. These technical and data structure standards aim to enhance the quality of long-term size distribution measurements, their comparability between different networks and sites, and their transparency and traceability back to raw data.

scholarly journals Long-term observations of aerosol size distributions in semi-clean and polluted savannah in South Africa

2013 ◽  
Vol 13 (4) ◽  
pp. 1751-1770 ◽  
Author(s):  
V. Vakkari ◽  
J. P. Beukes ◽  
H. Laakso ◽  
D. Mabaso ◽  
J. J. Pienaar ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Diurnal Variation ◽  
Size Distribution ◽  
Aerosol Particles ◽  
Informal Settlements ◽  
Particle Formation ◽  
Dry Season ◽  
Size Distributions ◽  
New Particle Formation

Abstract. This study presents a total of four years of sub-micron aerosol particle size distribution measurements in the southern African savannah, an environment with few previous observations covering a full seasonal cycle and the size range below 100 nm. During the first 19 months, July 2006–January 2008, the measurements were carried out at Botsalano, a semi-clean location, whereas during the latter part, February 2008–May 2010, the measurements were carried out at Marikana (approximately 150 km east of Botsalano), which is a more polluted location with both pyrometallurgical industries and informal settlements nearby. The median total concentration of aerosol particles was more than four times as high at Marikana than at Botsalano. In the size ranges of 12–840 nm, 50–840 nm and 100–840 nm the median concentrations were 1856, 1278 and 698 particles cm−3 at Botsalano and 7805, 3843 and 1634 particles cm−3 at Marikana, respectively. The diurnal variation of the size distribution for Botsalano arose as a result of frequent regional new particle formation. However, for Marikana the diurnal variation was dominated by the morning and evening household burning in the informal settlements, although regional new particle formation was even more frequent than at Botsalano. The effect of the industrial emissions was not discernible in the size distribution at Marikana although it was clear in the sulphur dioxide diurnal pattern, indicating the emissions to be mostly gaseous. Seasonal variation was strongest in the concentration of particles larger than 100 nm, which was clearly elevated at both locations during the dry season from May to September. In the absence of wet removal during the dry season, the concentration of particles larger than 100 nm had a correlation above 0.7 with CO for both locations, which implies incomplete burning to be an important source of aerosol particles during the dry season. However, the sources of burning differ: at Botsalano the rise in concentration originates from regional wild fires, while at Marikana domestic heating in the informal settlements is the main source. Air mass history analysis for Botsalano identified four regional scale source areas in southern Africa and enabled the differentiation between fresh and aged rural background aerosol originating from the clean sector, i.e., western sector with very few large anthropogenic sources. Comparison to size distributions published for other comparable environments in Northern Hemisphere shows southern African savannah to have a unique combination of sources and meteorological parameters. The observed strong link between combustion and seasonal variation is comparable only to the Amazon basin; however, the lack of long-term observations in the Amazonas does not allow a quantitative comparison. All the data presented in the figures, as well as the time series of monthly mean and median size distributions are included in numeric form as a Supplement to provide a reference point for the aerosol modelling community.

scholarly journals Long-term observations of aerosol size distributions in semi-clean and polluted savannah in South Africa

2012 ◽  
Vol 12 (9) ◽  
pp. 24043-24093
Author(s):  
V. Vakkari ◽  
J. P. Beukes ◽  
H. Laakso ◽  
D. Mabaso ◽  
J. J. Pienaar ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Diurnal Variation ◽  
Size Distribution ◽  
Aerosol Particles ◽  
Informal Settlements ◽  
Particle Formation ◽  
Dry Season ◽  
Size Distributions ◽  
New Particle Formation

Abstract. This study presents a total of four years of sub-micron aerosol particle size distribution measurements in the Southern African savannah, an environment with few previous observations covering a full seasonal cycle and the size range below 100 nm. During the first 19 months, July 2006–January 2008, the measurements were carried out at Botsalano, a semi-clean location, whereas during the latter part, February 2008–May 2010, the measurements were carried out at Marikana (approximately 150 km east of Botsalano), which is a more polluted location with both pyrometallurgical industries and informal settlements nearby. The median total concentration of aerosol particles was more than four times as high at Marikana than at Botsalano. In the size ranges of 12–840 nm, 50–840 nm and 100–840 nm the median concentrations were 1850, 1280 and 700 particles cm−3 at Botsalano and 7800, 3800 and 1600 particles cm−3 at Marikana, respectively. The diurnal variation of the size distribution for Botsalano arose as a result of frequent regional new particle formation. However, for Marikana the diurnal variation was dominated by the morning and evening household burning in the informal settlements, although regional new particle formation was even more frequent than at Botsalano. The effect of the industrial emissions was not discernible in the size distribution at Marikana although it was clear in the sulphur dioxide diurnal pattern, indicating the emissions to be mostly gaseous. Seasonal variation was strongest in the concentration of particles larger than 100 nm, which was clearly elevated at both locations during the dry season from May to September. In the absence of wet removal during the dry season the concentration of particles larger than 100 nm had a correlation above 0.7 with CO for both locations, which implies incomplete burning to be an important source of aerosol particles during the dry season. However, the sources of burning differ: at Botsalano the rise in concentration originates from regional wild fires, while at Marikana domestic heating in the informal settlements is the main source. Air mass history analysis for Botsalano identified four regional scale source areas in Southern Africa and enabled the differentiation between fresh and aged rural background aerosol originating from the clean sector, i.e., western sector with very few large anthropogenic sources. Comparison to size distributions published for other comparable environments in Northern Hemisphere shows Southern African savannah to have a unique combination of sources and meteorological parameters. The observed strong link between combustion and seasonal variation is comparable only to the Amazon basin; however the lack of long-term observations in the Amazonas does not allow a quantitative comparison. All the data presented in the figures, as well as the time series of monthly mean and median size distributions are included in numeric form as a Supplement to provide a reference point for the aerosol modelling community.

scholarly journals What do we learn from long-term cloud condensation nuclei number concentration, particle number size distribution, and chemical composition measurements at regionally representative observatories?

2017 ◽  
Author(s):  
Julia Schmale ◽  
Silvia Henning ◽  
Stefano Decesari ◽  
Bas Henzing ◽  
Helmi Keskinen ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Size Distribution ◽  
Radiative Forcing ◽  
Particle Number ◽  
Number Concentration ◽  
Size Distributions ◽  
Number Size Distribution ◽  
Particle Number Size Distribution ◽  
Composition Measurements

Abstract. Aerosol-cloud interactions (ACI) constitute the single largest uncertainty in anthropogenic radiative forcing. To reduce the uncertainties and gain more confidence in the simulation of ACI, models need to be evaluated against observations, in particular against measurements of cloud condensation nuclei (CCN). Numerous observations of CCN number concentration exist, and many closure studies have been performed to predict CCN number concentrations based on particle number size distributions, chemical composition, and the κ-Köhler theory. Most of these studies provide details for short time periods or focus on special environmental conditions. These observations, however, cannot address questions of large-scale temporal and spatial CCN variability. Here we analyze long-term observations of CCN number concentrations, particle number size distributions and chemical composition from twelve sites on three continents. Eight of these stations are part of the European Aerosols, Clouds, and Trace gases Research InfraStructure (ACTRIS). We group the observatories into categories according to their official classification: coastal background (Barrow, Alaska; Mace Head, Ireland; Finokalia, Crete; Noto Peninsula, Japan), rural background (Melpitz, Germany; Cabauw, the Netherlands; Vavihill, Sweden), alpine sites (Puy de Dôme, France; Jungfraujoch, Switzerland), remote forest sites (ATTO, Brazil; SMEAR, Finland) and the urban environment (Seoul, South Korea). Expectedly, CCN characteristics are highly variable across regions. However, they also vary within categories, most strongly in the coastal background group, where CCN number concentrations can vary by up to a factor of 30 within one season. In terms of particle activation behavior, most continental stations exhibit very similar relative activation ratios across the range of 0.1 to 1.0 % supersaturation. At the coastal sites the activation ratios spread more widely across the SS spectrum. Several stations show strong seasonal cycles of CCN number concentrations and particle number size distributions, e.g., at Barrow (Arctic Haze in spring), at the alpine stations (stronger influence of polluted boundary layer air masses in summer), the rain forest (wet and dry season), or Finokalia (forest fire influence in fall). The rural background and urban sites exhibit relatively little variability throughout the year while short-term variability can be high especially at the urban site. The average hygroscopicity parameter, κ, calculated from the chemical composition of submicron particles, was highest at the coastal site of Mace Head (0.6) and the lowest at the rain forest station ATTO (0.2–0.3). We performed closure studies to predict CCN number concentrations from the particle number size distribution and chemical composition measurements. The prediction accuracy for the average concentrations is high. The ratio between predicted and measured CCN concentrations is between 0.87 and 1.4. The temporal variability is also well represented, as reflected by Pearson correlation coefficients > 0.87. We also conducted a series of sensitivity studies for the ratio of predicted versus measured CCN concentration, where we varied the hygroscopicity parameter κ, and made simple assumptions for aerosol particle number concentrations and size distributions. Uncertain particle number concentrations and their size distributions significantly impair the accuracy in predicting temporal variability and hence of absolute concentrations, while the effect of uncertain κ values is limited to the predicted CCN number concentration. Information on CCN number concentrations at many locations is important to better characterize ACI and their radiative forcing. Long-term comprehensive aerosol particle characterizations are labor intensive and costly. For observatories where such efforts are out of scope to obtain nevertheless long-term information of CCN number concentrations, we recommend conducting collocated CCN number concentration and particle number size distribution measurements at individual locations throughout one year at least to derive a seasonally resolved hygroscopicity parameter. This way, CCN number concentrations can be calculated based on continued particle number size distribution information only. This approach is a good alternative to deriving kappa from time-resolved chemical composition measurements which are costly and may still not cover the appropriate size range. Additionally, given the variability in observations at sites of the same category, a certain density in spatial coverage of observations is needed, especially along coastlines. We recommend operating "migrating-CCNCs" at priority locations, identified by model evaluation, around the globe where long-term particle number size distribution data are already available.

Long-term aerosol number size distributions down to 1 nm in urban Beijing

2021 ◽  
Author(s):  
Chenjuan Deng ◽  
Yiran Li ◽  
Xiaotong Chen ◽  
Jingkun Jiang
Keyword(s):  
Size Distribution ◽  
Size Range ◽  
Particle Diameter ◽  
Small Diameter ◽  
Aerosol Size Distribution ◽  
Size Distributions ◽  
Diurnal Patterns ◽  
The Mean ◽  
Meteorological Analysis

<p>To reveal the characteristics of aerosols in polluted environments, we measured aerosol number size distributions in the size range of ~1 nm – 10 μm during 2018- 2020 in urban Beijing. As a vital process influencing the aerosol size distributions, new particle formation (NPF) events were frequently observed in urban Beijing. We classified NPF days into typical NPF days with a burst of sub‑3 nm particles and those with few sub‑3 nm particles. We examined their characteristics and possible reasons. The mean aerosol number size distributions were clearly different and the peak particle diameter was ~1.5 nm and 12 nm, respectively. For those with a burst of sub-3 nm particles, however, the peak diameter shifts from small diameter to larger particle diameters as the aerosol size distribution evolves during the NPF process and then becomes similar to those with few sub-3 nm particles. Meteorological analysis indicates that airmass movement may account for these observations. Despite these differences, similar diurnal patterns were observed on most days in urban Beijing, i.e., drastic change in aerosol size distributions happens around 4:00 a.m. and 4:00 p.m.</p>

scholarly journals Establishment Size Dynamics in the Aggregate Economy

2007 ◽  
Vol 97 (5) ◽  
pp. 1639-1666 ◽  
Author(s):  
Esteban Rossi-Hansberg ◽  
Mark L. J Wright
Keyword(s):  
Human Capital ◽  
Size Distribution ◽  
Growth Rates ◽  
Size Distributions ◽  
Establishment Size ◽  
Specific Human Capital ◽  
Relative Factor ◽  
Factor Intensities ◽  
Aggregate Economy

This paper presents a theory of establishment size dynamics based on the accumulation of industry-specific human capital that simultaneously rationalizes the economy-wide facts on establishment growth rates, exit rates, and size distributions. The theory predicts that establishment growth and net exit rates should decline faster with size, and that the establishment size distribution should have thinner tails, in sectors that use specific human capital less intensively. We establish that there is substantial cross-sector heterogeneity in US establishment size dynamics and distributions, which is well explained by relative factor intensities. (JEL L11, L16, L25).

scholarly journals A clinical observational analysis of aerosol emissions from dental procedures.

2021 ◽  
Author(s):  
Tom Dudding ◽  
Sadiyah Sheikh ◽  
Florence Gregson ◽  
Jennifer Haworth ◽  
Simon Haworth ◽  
...  
Keyword(s):  
Size Distribution ◽  
Oral Surgery ◽  
Aerosol Size Distribution ◽  
Size Distributions ◽  
Dental Procedures ◽  
Ethical Approval ◽  
Head Control ◽  
Particle Sizer ◽  
Aerosol Emissions ◽  
Phantom Head

There remains uncertainty as to which dental procedures constitute aerosol generating procedures. We aimed to quantify aerosol concentration produced during different dental procedures. Where aerosol was detected, we assessed whether the aerosol size distribution from patient procedures was explained by the non-salivary contaminated instrument source, using phantom head controls. This study obtained ethical approval within the AERATOR grant. Patients were recruited consecutively, and written consent was obtained. Both an optical and an aerodynamic particle sizer were used to measure aerosol, attached to a 3D-printed polylactide funnel 22cm from the patients face. A range of periodontal, oral surgery and orthodontic procedures were captured using time-stamped protocols. High-fidelity phantom head control experiments for each procedure were performed, under the same conditions. Aerosol was measured for each procedure. Where aerosol was detected, phantom head control and patient procedure aerosol size distributions were compared, with the assumption that if the distributions were the same, aerosol detected from the patient could be explained by the instrument source. 41 patients underwent fifteen different dental procedures. For nine procedures, no aerosol was detected. Where aerosol was detected, the percentage of procedure time that aerosol was observed above background ranged from 12.7% for ultrasonic scaling to 42.9% for 3-in-1 air + water syringe. For ultrasonic scaling, 3-in-1 syringe use and surgical drilling, the aerosol size distribution matched the non-salivary contaminated instrument source. High and slow speed drilling produced aerosol from patient procedures which appear to have different size distributions from a phantom head control and so may pose a greater risk of (potentially infected) salivary contamination. Ultrasonic scaling does not appear to generate additional aerosol above that of the instrument itself and therefore does not increase the risk to dental teams, relative to the risk from being in close proximity to the patient.

The Reproduction Vector of the Russian Economy: 1999-2007

2008 ◽  
pp. 94-109 ◽  
Author(s):  
D. Sorokin
Keyword(s):  
Economic Policy ◽  
Human Capital ◽  
Growth Rates ◽  
Developed Countries ◽  
Gdp Per Capita ◽  
Real Sector ◽  
Russian Economy ◽  
Per Capita ◽  
The Developed Countries

The problem of the Russian economy’s growth rates is considered in the article in the context of Russia’s backwardness regarding GDP per capita in comparison with the developed countries. The author stresses the urgency of modernization of the real sector of the economy and the recovery of the country’s human capital. For reaching these goals short- or mid-term programs are not sufficient. Economic policy needs a long-term (15-20 years) strategy, otherwise Russia will be condemned to economic inertia and multiplying structural disproportions.

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