Implications of the Low-frequency Turnover in the Spectrum of Radio Knot C in DG Tau

The synchrotron spectrum of radio knot C in the protostellar object DG Tau has a low-frequency turnover. This is used to show that its magnetic field strength is likely to be at least 10 mG, which is roughly two orders of magnitude larger than previously estimated. The earlier, lower value is due to an overestimate of the emission volume together with an omission of the dependence of the minimum magnetic field on the synchrotron spectral index. Since the source is partially resolved, this implies a low volume-filling factor for the synchrotron emission. It is argued that the high pressure needed to account for the observations is due to shocks. In addition, cooling of the thermal gas is probably necessary in order to further enhance the magnetic field strength as well as the density of relativistic electrons. It is suggested that the observed spectral index implies that the energy of the radio-emitting electrons is below that needed to take part in first-order Fermi acceleration. Hence, the radio emission gives insights to the properties of its pre-acceleration phase. Attention is also drawn to the similarities between the properties of radio knot C and the shock-induced radio emission in supernovae.

The Characteristics of PM2.5 Pollution and Policy Implications in Chungcheong Region

Objectives : This study aims to discuss air quality policy improvement that reflect regional characteristics through analyzing recent PM2.5 concentration, air pollutant emission sources and those contributions to annual PM2.5 concentration in Chungcheong region (Daejeon Metropolitan City, Sejong Metropolitan Autonomous City, the Province of Chungcheongnam-do, and Chungcheongbuk-do) in South Korea. In addition, we identified the characteristics of the PM2.5 pollution at the level of fundamental local government, and demonstrated the number of vulnerable population exposed to high level of PM2.5 concentration in order to propose policy implications in Chungcheong region.Methods : Based on the national emissions estimates (CAPSS: Clean Air Policy Support System) and air quality modelling system, major sectors/sources of air pollutants emission and national contributions of PM2.5 concentrations in Chungcheong region were analyzed. Furthermore, the study identified the number of people exposed to the higher PM2.5 concentrations (>25 µg/m3) by the measurement data and demographics available in 2019.Results and Discussion : The national air pollutants emissions in Chungcheong region were emitted from Chungnam (about 59% of NOx emission volume, 89% of SOx, 70% of NH3, 54% of VOCs, 79% of PM2.5, and 68% of TSP respectively), mainly from industry, domestic, energy, and road sector. According to the results of the air quality modelling, Chungcheong region also had the largest contribution on the average annual PM2.5 concentration in South Korea (27%). Chungnam emitted the largest emission volume of air pollutants, mainly from industry and power generation sectors (especially in Dangjin, Seosan, and Boryeong), while Asan, Yesan, Hongseong, and Cheongyang were classified as the areas with higher PM2.5 concentrations (>25 µg/m3), showing a gap between the areas with large emission volume and high concentration. Chungbuk and Sejong had higher annual PM2.5 concentration due to the influence of external sources and their geographical characteristics. The largest vulnerable population (over 65 years old and under 18 years old) exposed to high PM2.5 concentrations annually lived in Cheongju. Chungbuk had about 40% more air pollutant emission volume than Chungnam, but about 17% more vulnerable population.Conclusions : At the current stage of “master plan” in Chungcheong region, it is important to mitigate air pollutants emissions on the basis of the local emissions characteristic at the level of fundamental local government (such as industry sector in Dangjin, Seosan, and Danyang/ Domestic buring in Cheongju, Cheonan, and Daejeon/power generation in Boryeong, Taean and Dangjin/ road in Daejeon, Cheongju, and Cheoan). In addition, Chungbuk requires management of the areas with higher PM2.5 concentration such as Goesan, Boeun, Okcheon, and Yeongdong located outside “air control zone”. To reduce high level of PM2.5 concentration in Chungcheong region, cooperation with neighboring local governments such as Gyeonggi Province is crucial, and policy solutions are needed between the stakeholders to resolve the disparity issues between areas with larger emission volume and higher PM2.5 concentration.

Sources of Greenhouse Gas Emissions in Agriculture, with Particular Emphasis on Emissions from Energy Used

The relationship between agriculture and climate change is two-sided. Agriculture is the branch of the economy most affected by the ongoing processes. It is also a large emitter of greenhouse gases and there are more and more voices about the need to reduce emissions. The purpose of the study was, based on FADN (Farm Accountancy Data Network) data, to determine the structure of greenhouse gas emissions in farms and to identify types of farms where it is possible to reduce GHG (greenhouse gas) emissions through better energy use. The emission volume was determined on the basis of the IPCC (Intergovernmental Panel on Climate Change) methodology modified for the FADN data. The emissions related to the production of energy were found to be of minor importance compared to other emission sources. Only in the horticultural crop type is the emission from the Energy section the dominant stream of GHG emission. The greatest emissions come from livestock production. Therefore, the emphasis on reducing emissions should not be placed on the Energy sector because, except for the type of horticultural farm, there is not much potential for reduction. The introduction of taxes for GHG emissions at the level of 27.31 EUR/t would reduce farm income from 21% for the type of field crops to 40% for the type of herbivorous animals. The exception is low-emission permanent crops, where the decrease in income would be only 3.85%.

On nuclear coalescence in small interacting systems

The formation of light nuclei can be described as the coalescence of clusters of nucleons into nuclei. In the case of small interacting systems, such as dark matter and $$e^+e^-$$ e + e - annihilations or pp collisions, the coalescence condition is often imposed only in momentum space and hence the size of the interaction region is neglected. On the other hand, in most coalescence models used for heavy ion collisions, the coalescence probability is controlled mainly by the size of the interaction region, while two-nucleon momentum correlations are either neglected or treated as collective flow. Recent experimental data from pp collisions at LHC have been interpreted as evidence for such collective behaviour, even in small interacting systems. We argue that these data are naturally explained in the framework of conventional QCD inspired event generators when both two-nucleon momentum correlations and the size of the hadronic emission volume are taken into account. To include both effects, we employ a per-event coalescence model based on the Wigner function representation of the produced nuclei states. This model reproduces well the source size for baryon emission and the coalescence factor $$B_2$$ B 2 measured recently by the ALICE collaboration in pp collisions.

Impact of carbon emission on financial performance: empirical evidence from India

PurposeThe purpose of this study is to examine the effect of carbon emission on accounting and market-based financial performance of Indian companies.Design/methodology/approachFirms reporting emission data on Carbon Disclosure Project (CDP) are considered for empirical analysis and the data have been collected for the period from 2013 to 2019. The study adopts Heckman's regression model to control for self-selection bias and it also examines the moderating role of environmental sensitivity through industry-wise analysis. The results are also checked for potential endogeneity using generalized methods of moments estimation.FindingsPrimarily, the findings postulate a significant negative impact of carbon emissions on both measures of financial performance. Further, it also determines that environmentally sensitive firms are more exposed to such negative influence of emission compared to nonsensitive companies.Research limitations/implicationsCurrent research will enhance the understanding of managers about the economic impact of carbon emission, especially in an economy where emissions are not completely regulated. The study provides an economic rationale to the industries to reduce emission volume. It will also assist regulators to draft environmental policies by considering environmental sensitivity. It should be noted that the study is based on the Indian firms that have reported emission data on the CDP during the study period.Originality/valueThe present study addresses one of the most important but less explored issues of environmental research in one of the largest emerging economies of the South Asian region. The study presents a comprehensive view by covering accounting as well as market-based indicators along with the moderating effect of environmental sensitivity.

Micro-engineered Nanowire Electron Source for Atomic Resolution Imaging

The size tunability and chemical versatility of nanostructures provide attractive engineering potential to realize an electron source of high brightness and spatial temporal coherence, which is a characteristic ever pursued by high resolution electron microscopy. (1–3) Regardless of the intensive research efforts, electron sources that have ever produced atomic resolution images are still limited to the conventional field emitters based on a bulk W needle. It is due to the lack of fabrication precision for nanostructured sources, that is required to align a nanometric emission volume along a macroscopic emitter axis with sub-degree angular deviation. (4) In this work, we produced a LaB6 nanowire electron source which was micro-engineered to ensure a highly collimated electron beam with perfect lateral and angular alignment. Such electron source was validated by installing in an aberration-corrected transmission electron microscope, where atomic resolution in both broad-beam and probe-forming modes were demonstrated at 60kV beam energy. The recorded un-monochromated 0.20eV electron energy loss spectroscopy (EELS) resolution, together with 20% probe forming efficiency and 0.4% probe current peak-to-peak noise ratio under a wide vacuum range, presented the unique advantages of nanotechnology and promised high performance low-cost electron beam instruments.

Economic Aspects of Ecological Problems Solving for Russian Cities

The subject of the research is the ecological situation in 12 selected cities: Bratsk, Krasnoyarsk, Lipetsk, Magnitogorsk, Mednogorsk, Nizhniy Tagil, Novokuznetsk, Norilsk, Omsk, Chelyabinsk, Cherepovets and Chita. The purposes of the work are to analyze the structure, subjects, goals and objectives of the project “Pure Air” that is a part of a large-scale national project “Ecology”, as well as to evaluate the concrete character level of the proposed actions and their prospective effectiveness. In the course of the research only open sources of information, data of statistical organizations and relevant Ministries Departments were used. A conclusion is made about the large scale of the declared investment programmes of industrial enterprises (including heat-andpower enterprises) that will highly likely be fulfilled as they are carried out at the sole cost and expense of the enterprises. It is concluded in the article that complex plans to reduce emission of pollutants appear to be quite consequent and well-developed and they should lead to the achievement of the main project goal that is to reduce the total emission volume by at least 20%, and to change the load status of the cities under consideration from “very high” to “high”. If the majority of the actions planned is realized, the ecological situation in the selected cities will change significantly, which will allow to use the obtained experience in other Russian cities.

EMISSION EFFICIENCY OF EUROPEAN UNION COUNTRIES

The aim of the study was to compare the total greenhouse gas emissions in the European Union countries and their emission efficiency. Emission efficiency was calculated as the ratio of emission volume and value to gross value added generated by the economy of a given country (size of the economy). The necessary statistical data was obtained from Eurostat. It was found that in 2015 most of greenhouse gases were emitted by: Germany, United Kingdom, Poland, France and Italy. At the same time, France and the United Kingdom were characterized by one of the best emission efficiency in the European Union, Germany and Italy obtained average results, while Poland was in the group of countries with the lowest emission efficiency. Therefore, it can be concluded, that the volume of emissions is significantly affected by the size of the economy. Some large emitters have economies based on relatively “clean” technologies and thus their potential to further reduction is not very high. The reverse is true for some low-emission countries, such as Estonia and Bulgaria. This indicates the need for a more comprehensive look at the problem of reducing greenhouse gas emissions.

Roadway Lighting Retrofit: Environmental and Economic Impact of Greenhouse Gases Footprint Reduction

Roadway lighting retrofit is a process continuously developed in urban environments due to both installation aging and technical upgrades. The spectacular example is replacing the high intensity discharge (HID) lamps, usually high pressure sodium (HPS) ones, with the sources based on light-emitting diodes (LED). The main focus in the related research was put on energy efficiency of installations and corresponding financial benefits. In this work, we extend those considerations analyzing how lighting optimization impacts greenhouse gas (GHG) emission reduction and what are the resultant financial benefits expressed in terms of emission allowances prices. Our goal is twofold: (i) obtaining a quantitative assessment of how a GHG footprint depends on a technological scope of modernization of a city HPS-based lighting system; and (ii) showing that the costs of such a modernization can be decreased by up to 10% thanks to a lowered CO 2 emission volume. Moreover, we identify retrofit patterns yielding the most substantial environmental impact.