Carbon emission fluctuations of Chinese inter-regional interaction: a network multi-hub diffusion perspective.

The "double-carbon" policy is a new opportunity for the transformation of China's production sector. With steady economic growth, each province has proposed specific policies aimed at cleaner production. However, the interactions between regions and the complex linkages between industries have hindered the implementation of the "double-carbon" policy. In order to address this issue, we introduced a complex network framework with multiple industries at a national level. The framework aimed to clarify whether there is fluctuation diffusion in China's multi-province multi-industry carbon emission system, to identify key industries and regions, and to answer the question of "who" is the most effective in governance. The results showed that the fluctuations of industrial carbon emissions had a cross-regional diffusion effect in China indeed. The diffusion capacity of industry fluctuation depends on whether the industry is located at a "hub" position in the network. Hub industries with strong capacity can spread the carbon emission fluctuation of themselves and upstream or downstream industries to the whole country through regional interactions. This characteristic of the hub industry should be taken into account in governance to maximize the effectiveness of emission reduction. Shandong and Inner Mongolia, as important provinces for the production of intermediate products and energy chemicals in China, had a greater role to play in global carbon supply push from their hub industries than in the demand pull. The pulling capacity of Beijing-Tianjin-Hebei region to the national carbon demand side was greater than that of Yangtze River Delta and Pearl River Delta. These findings might have implications for environmental and economic policymaking, particularly with regard to cross-provincial coordinated systemic solutions and policy anchors for synergy with industries.

Can new energy demonstration city policy reduce carbon emissions? A quasi-natural experiment from China.

Against achieving carbon peaking by 2030 and carbon neutrality by 2060 context in China, the new energy demonstration city policy (NEDCP) has a crucial function to perform in promoting resource utilization efficiency, building the green development policy system, and facilitating carbon emission reduction. However, existing research has rarely investigated the contribution of NEDCP on carbon reduction. To investigate the policy effect of NEDCP, the differences-in-differences (DID) model is introduced to quantify the influence of NEDCP on carbon reduction, taking a statistical sample of 285 Chinese cities over the period 2005-2017 on the basis of exploring the intrinsic mechanism of NEDCP on carbon emissions. The statistical results reveal that NEDCP significantly inhibits carbon emissions. NEDCP's dampening impact on carbon reduction is more pronounced in the eastern area but not in other areas. City size and resource endowment heterogeneity results suggest that NEDCP significantly inhibits the output of carbon emissions in non-resource-based and large cities but insignificantly in resource-based and small- and medium-sized cities. Finally, we conclude that policy-makers should not only broaden the scope of NEDCP implementation continuously but also design relevant policy combination tools following the basic characteristics of each city to provide institutional guarantees for achieving carbon emission reduction.

A simple predictive model for estimating relative e-cigarette toxic carbonyl levels.

E-cigarette devices are wide ranging, leading to significant differences in levels of toxic carbonyls in their respective aerosols. Power can be a useful method in predicting relative toxin concentrations within the same device, but does not correlate well to inter-device levels. Herein, we have developed a simple mathematical model utilizing parameters of an e-cigarette's coil and wick in order to predict relative levels of e-liquid solvent degradation. Model 1, which is coil length/(wick surface area*wraps), performed in the moderate-to-substantial range as a predictive tool (R2 = 0.69). Twelve devices, spanning a range of coil and wick styles, were analyzed. Model 1 was evaluated against twelve alternative models and displayed the best predictability. Relationships that included power settings displayed weak predictability, validating that power levels cannot be reliably compared between devices due to differing wicking and coil components and heat transfer efficiencies.

Determining Inorganic and Organic Carbon.

Carbon is the element which makes up the major fraction of lipids and carbohydrates, which could be used for making biofuel. It is therefore important to provide enough carbon and also follow the flow into particulate organic carbon and potential loss to dissolved organic forms of carbon. Here we present methods for determining dissolved inorganic carbon, dissolved organic carbon, and particulate organic carbon.

Discrimination of three Ephedra species and their geographical origins based on multi-element fingerprinting by inductively coupled plasma mass spectrometry.

Discrimination of species and geographical origins of traditional Chinese medicine (TCM) is essential to prevent adulteration and inferior problems. We studied Ephedra sinica Stapf, Ephedra intermedia Schrenk et C.A.Mey. and Ephedra przewalskii Bge. to investigate the relationship between inorganic element content and these three species and their geographical origins. 38 elemental fingerprints from six major Ephedra-producing regions, namely, Inner Mongolia, Ningxia, Gansu, Shanxi, Shaanxi, and Sinkiang, were determined to evaluate the importance of inorganic elements to three species and their geographical origins. The contents of 15 elements, namely, N, P, K, S, Ca, Mg, Fe, Mn, Na, Cl, Sr, Cu, Zn, B, and Mo, of Ephedra samples were measured using inductively coupled plasma mass spectroscopy. Elemental contents were used as chemical indicators to classify species and origins of Ephedra samples using a radar plot and multivariate data analysis, including hierarchical cluster analysis (HCA), principal component analysis (PCA), and discriminant analysis (DA). Ephedra samples from different species and geographical origins could be differentiated. This study showed that inorganic elemental fingerprint combined with multivariate statistical analysis is a promising tool for distinguishing three Ephedra species and their geographical origins, and this strategy might be an effective method for authenticity discrimination of TCM.

δ13CDIC tracing of dissolved inorganic carbon sources at Three Gorges Reservoir, China.

In order to understand water chemistry after impoundment of the Three Gorges Reservoir (TGR), the authors assessed the hydrogeochemical parameters (water temperature, pH, conductivity, dissolved O2), major element composition, and the carbon stable isotopic value of dissolved inorganic carbon (δ13CDIC) in summer and winter at various depths in the water column at TGR in 2009. In reservoir water, the DO values are lower in winter than in summer, but the pH values and conductivity values are higher. Ca2+ and Na+ are the dominant cations and HCO3- and SO42- are the dominant anions. In surface waters, the δ13CDIC values are more negative in summer than they are in winter, whereas the dissolved inorganic carbon (DIC) concentrations are relatively lower. In the water column, the DIC and δ13CDIC values do not change significantly with water depth or seasons. The DIC content shows a dilution effect in summer and is not modified by phytoplanktonic activity or photosynthesis. Even after the dam obstructed flow, the chemical profile of water in TGR is similar to that of the natural rivers before impoundment. Therefore, in this study, the water at TGR still had riverine characteristics and was still a heterotrophic system.

Real-Time Measurements and Characterization of Airborne Particulate Matter from a Primary Silicon Carbide Production Plant.

Airborne particulate matter in the silicon carbide (SiC) industry is a known health hazard. The aims of this study were to elucidate whether the particulate matter generated inside the Acheson furnace during active operation is representative of the overall particulate matter in the furnace hall, and whether the Acheson furnaces are the main sources of ultrafine particles (UFP) in primary SiC production. The number concentration of ultrafine particles was evaluated using an Electrical Low Pressure Impactor (ELPITM, Dekati Ltd., Tampere, Finland), a Fast Mobility Particle Sizer (FMPSTM, TSI, Shoreview, MN, USA) and a Condensation Particle Counter (CPC, TSI, Shoreview, MN, USA). The results are discussed in terms of particle number concentration, particle size distribution and are also characterized by means of electron microscopy (TEM/SEM). Two locations were investigated; the industrial Acheson process furnace hall and a pilot furnace hall; both of which represent an active operating furnace. The geometric mean of the particle number concentration in the Acheson process furnace hall was 7.7 × 104 particles/cm³ for the UFP fraction and 1.0 × 105 particles/cm³ for the submicrometre fraction. Particulate matter collected at the two sites was analysed by electron microscopy. The PM from the Acheson process furnace hall is dominated by carbonaceous particles while the samples collected near the pilot furnace are primarily rich in silicon.

Decoupling between the response of coral calcifying fluid pH and calcification to ocean acidification.

Evaluating the factors responsible for differing species-specific sensitivities to declining seawater pH is central to understanding the mechanisms via which ocean acidification (OA) affects coral calcification. We report here the results of an experiment comparing the responses of the coral Acropora yongei and Pocillopora damicornis to differing pH levels (8.09, 7.81, and 7.63) over an 8-week period. Calcification of A. youngei was reduced by 35% at pH 7.63, while calcification of P. damicornis was unaffected. The pH in the calcifying fluid (pHcf) was determined using δ11B systematics, and for both species pHcf declined slightly with seawater pH, with the decrease being more pronounced in P. damicornis. The dissolved inorganic carbon concentration at the site of calcification (DICcf) was estimated using geochemical proxies (B/Ca and δ11B) and found to be double that of seawater DIC, and increased in both species as seawater pH decreased. As a consequence, the decline of the saturation state at the site of calcification (Ωcf) with OA was partially moderated by the DICcf increase. These results highlight that while pHcf, DICcf and Ωcf are important in the mineralization process, some corals are able to maintain their calcification rates despite shifts in their calcifying fluid carbonate chemistry.

Low-smoke chulha in Indian slums: study protocol for a randomised controlled trial.

BACKGROUND: Biomass fuel is used as a primary cooking source by more than half of the world's population, contributing to a high burden of disease. Although cleaner fuels are available, some households continue using solid fuels because of financial constraints and absence of infrastructure, especially in non-notified slums. The present study documents a randomised controlled study investigating the efficacy of improved cookstove on the personal exposure to air pollution and the respiratory health of women and children in an Indian slum. The improved cookstove was based on co-creation of a low-smoke chulha with local communities in order to support adaption and sustained uptake. METHODS: The study will be conducted in a non-notified slum called Ashrayanagar in Bangalore, India. The study design will be a 1:1 randomised controlled intervention trial, including 250 households. The intervention group will receive an improved cookstove (low-smoke chulha) and the control group will continue using either the traditional cookstove (chulha) or a combination of the traditional stove and the kerosene/diesel stove. Follow-up time is 1 year. Outcomes include change in lung function (FEV1/FVC), incidence of pneumonia, change in personal PM2.5 and CO exposure, incidence of respiratory symptoms (cough, phlegm, wheeze and shortness of breath), prevalence of other related symptoms (headache and burning eyes), change in behaviour and adoption of the stove. Ethical clearance was obtained from the Institutional Ethics Committee of the Indian Institute of Public Health Hyderabad- Bengaluru Campus. DISCUSSION: The findings from this study aim to provide insight into the effects of improved cookstoves in urban slums. Results can give evidence for the decrease of indoor air pollution and the improvement of respiratory health for children and women. TRIAL REGISTRATION: The trial was registered with clinicaltrials.gov on 21 June 2016 with the identifier NCT02821650 ; A Study to Test the Impact of an Improved Chulha on the Respiratory Health of Women and Children in Indian Slums.

Stable isotope mass balances versus concentration differences of dissolved inorganic carbon - implications for tracing carbon turnover in reservoirs.

The aim of this study was to identify sources of carbon turnover using stable isotope mass balances. For this purpose, two pre-reservoirs in the Harz Mountains (Germany) were investigated for their dissolved and particulate carbon contents (dissolved inorganic carbon (DIC), dissolved organic carbon, particulate organic carbon) together with their stable carbon isotope ratios. DIC concentration depth profiles from March 2012 had an average of 0.33 mmol L-1. Increases in DIC concentrations later on in the year often corresponded with decreases in its carbon isotope composition (δ13CDIC) with the most negative value of -18.4 ‰ in September. This led to a carbon isotope mass balance with carbon isotope inputs of -28.5 ‰ from DOC and -23.4, -31.8 and -30.7 ‰ from algae, terrestrial and sedimentary matter, respectively. Best matches between calculated and measured DIC gains were achieved when using the isotope composition of algae. This shows that this type of organic material is most likely responsible for carbon additions to the DIC pool when its concentrations and δ13CDIC values correlate negatively. The presented isotope mass balance is transferable to other surface water and groundwater systems for quantification of organic matter turnover.

Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice.

The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m-2. Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean.

Nano-scale elastic-plastic properties and indentation-induced deformation of single crystal 4H-SiC.

The nanoscale elastic-plastic response of single crystal 4H-SiC has been investigated by nanoindentationwith a Berkovich tip. The hardness (H) and elastic modulus (E) determined in the load-independent region were 36±2GPa and 413±8GPa, respectively. The indentation size effect (ISE) of hardness within an indentation depth of 60nm was systematically analyzed by the Nix-Gao model. Pop-in events occurring at a depth of ~23nm with indentation loads of 0.60-0.65mN were confirmed to indicate the elastic-plastic transition of the crystal, on the basis of the Hertzian contact theory and Johnson's cavity model. Theoritically calculated maximum tensile strength (13.5GPa) and cleavage strength (33GPa) also affirms the deformation due to the first pop-in rather than tensile stresses. Further analyses of deformation behavior across the indent was done in 4H-SiC by a combined technique of focused ion beam and transmission electron microscope, revealing that slippage occurred in the (0001) plane after indentation.

Application of δ(18)O, δ(13)CDIC, and major ions to evaluate micropollutant sources in the Bay of Vidy, Lake Geneva.

Waters were sampled monthly from a profile at the wastewater outlet and a reference point in the Bay of Vidy (Lake Geneva) for a year. The samples were analyzed for (18)O/(16)O of water, (13)C/(12)C of dissolved inorganic carbon (DIC), major ions, and selected micropollutant concentrations. δ(18)O values, combined with the major ion concentrations, allowed discharged waste and storm-drainage water to be traced within the water column. On the basis of δ(18)O values, mole fractions of wastewater (up to 45 %), storm-drainage (up to 16 %), and interflowing Rhône River water (up to 34 %) could be determined. The results suggest that the stormwater fractions do not influence micropollutant concentrations in a measurable way. In contrast, the Rhône River interflow coincides with elevated concentrations of Rhône River-derived micropollutants in some profiles. δ(13)C values of DIC suggest that an increase in micropollutant concentrations at the sediment-water interface could be related to remineralization processes or resuspension.

Toxic metal (Pb, Cd, Cr, and Hg) levels in Rapana venosa (Valenciennes, 1846), Eriphia verrucosa (Forskal, 1775), and sediment samples from the Black Sea littoral (Thrace, Turkey).

Rapana venosa (Valenciennes, 1846) and Eriphia verrucosa (Forskal, 1775) are the dominant benthic invertebrate species along the Thrace Coast of the western Black Sea. The aim of this study was to determine toxic metal (Hg, Cr, Cd, and Pb) accumulation levels in these species, as well as within littoral sediments from this area. Our results showed that all of the metals, except for Cd, were below that in average shale. The measured accumulation levels were mostly within the range of what is naturally found within the earth's crust. However, some study stations did have increased concentrations, indicating anthropogenic pollution in these areas. The Cd contents of E. verrucosa collected from all our study stations were well above the limits set by the Turkish Food Codex, especially in Kiyiköy, whereas Pb content was close to the limit at all stations and exceeded the limit in Kiyiköy, but Hg content was below the limit at all stations. Cd content of R. venosa exceeded the limit only in Kumköy. Pb content was below the limit, and Hg was at or slightly above the limit at all stations.

Determination of the origin of dissolved inorganic carbon in groundwater around a reclaimed landfill in Otwock using stable carbon isotopes.

Chemical and isotopic analyses of groundwater from piezometers located around a reclaimed landfill in Otwock (Poland) were performed in order to trace the origin of dissolved inorganic carbon (DIC) in the groundwater. Due to differences in the isotopic composition of carbon from different sources, an analysis of stable carbon isotopes in the groundwater, together with the Keeling plot approach and a two-component mixing model allow us to evaluate the relative contributions of carbon from these sources in the groundwater. In the natural (background) groundwater, DIC concentrations and the isotopic composition of DIC (δ(13)CDIC) comes from two sources: decomposition of organic matter and carbonate dissolution within the aquifer sediments, whereas in the leachate-contaminated groundwater, DIC concentrations and δ(13)CDIC values depend on the degradation of organic matter within the aquifer sediments and biodegradation of organic matter stored in the landfill. From the mixing model, about 4-54% of the DIC pool is derived from organic matter degradation and 96-46% from carbonate dissolution in natural conditions. In the leachate-contaminated groundwater, about 20-53% of the DIC is derived from organic matter degradation of natural origin and 80-47% from biodegradation of organic matter stored in the landfill. Partial pressure of CO2 (P CO2) was generally above the atmospheric, hence atmospheric CO2 as a source of carbon in DIC pool was negligible in the aquifer. P CO2 values in the aquifer in Otwock were always one to two orders of magnitude above the atmospheric P CO2, and thus CO2 escaped directly into the vadose zone.

Artificial soil studies reveal domain-specific preferences of microorganisms for the colonisation of different soil minerals and particle size fractions.

Artificial soils were used in this study to analyse the importance of different mineral compositions for the diversity of soil microorganisms. Variants containing montmorillonite (MT), illite (IL) and illite + ferrihydrite (IL+FH) were compared to each other. Bulk material and their particle size fractions, as obtained by ultracentrifugation and wet-sieving, were characterised for abundance and diversity of Bacteria, Archaea and Fungi. Samples were analysed 6 and 18 months after inoculation with sterilised manure and a soil-extracted microbial community. Generally, IL, and even more pronouncedly IL+FH, supported the growth of more Bacteria, Archaea and Fungi, than MT. This trend was most pronounced in the finest fraction (< 20 µm). The structural diversity of Fungi responded more strongly to the different mineral compositions than the Bacteria, for which particle size fractions were more important. Archaea established a specific community in the finest fraction and showed no response to the different mineral compositions. Overall, this study demonstrates that the mineral composition and the particle size fractions have specific and different selective effects on the three domains and, thus, suggests that these factors strongly contribute to niche separation and the high diversity of microbial communities in natural soils with complex mineral compositions.

Changes in the bacterial community structure in stored wormbed leachate.

Organic wastes, such as cow manure, are often composted with earthworms (vermicomposting) while excess water is drained and collected. This wormbed leachate is nutrient-rich and it has been extensively used to fertilize plants. However, it is derived partially from a not yet finished compost process and could exhibit phytotoxicity or contain potentially hazardous microorganisms. The bacterial community in wormbed leachate derived from vermicomposting of cow manure was studied by pyrosequencing the 16S rRNA gene. The fresh wormbed leachate was rich in Mollicutes, particularly the genus Acholeplasma which contain phytopathogen species. The abundance of the Mollicutes decreased when the leachate was stored, while that of the Rhizobiales and the genus Pseudomonas increased. The bacterial communities changed rapidly in the leachate during storage. The changes in ammonium, nitrate and inorganic carbon content of the wormbed leachate when stored were correlated to changes in the bacterial community structure. It was found that storage of the wormbed leachate might be required before it can be applied to crops as large proportions of potentially plant pathogens were found in the fresh leachate.

Ultrasonic sensor based defect detection and characterisation of ceramics.

Ceramic tiles, used in body armour systems, are currently inspected visually offline using an X-ray technique that is both time consuming and very expensive. The aim of this research is to develop a methodology to detect, locate and classify various manufacturing defects in Reaction Sintered Silicon Carbide (RSSC) ceramic tiles, using an ultrasonic sensing technique. Defects such as free silicon, un-sintered silicon carbide material and conventional porosity are often difficult to detect using conventional X-radiography. An alternative inspection system was developed to detect defects in ceramic components using an Artificial Neural Network (ANN) based signal processing technique. The inspection methodology proposed focuses on pre-processing of signals, de-noising, wavelet decomposition, feature extraction and post-processing of the signals for classification purposes. This research contributes to developing an on-line inspection system that would be far more cost effective than present methods and, moreover, assist manufacturers in checking the location of high density areas, defects and enable real time quality control, including the implementation of accept/reject criteria.

[Transported fluxes of the riverine carbon and seasonal variation in Pearl River basin].

The riverine carbon flux is a critical component of global carbon cycle. Riverine water samples were collected from eleven hydrometric stations in the main stream of Pearl River and its tributaries during April and July, 2012. The samples were analyzed for the space and seasonal distribution characteristics of the riverine suspended substance and carbon compositions. Carbon fluxes and erosion modulus of Pearl River basin were also estimated in Boluo, Shijiao, Gaoyao, namely Dongjiang, Beijiang, Xijiang, in these two hydrological seasons. The results showed that the total suspended substance (TSS) and organic carbon, including total particulate organic carbon (POC) and dissolved organic carbon (DOC) have higher concentration in the high-water season than that in the normal-water season. Dissolved inorganic carbon (DIC) has an overwhelming concentration compared to other carbon compositions in Pearl River basin. The DIC concentration shows an order of Xijiang, Beijiang and Dongjiang from high to low. The percentage of allogenic POC in Xijiang, Beijiang and Dongjiang are 78%, 72%, 26%, respectively, and C3 plants are the main sources of allogenic POC in those three tributaries. The transported fluxes of TSS, total carbon (TC), POC, particulate inorganic carbon (PIC), DOC, DIC, total particulate carbon (TPC) and total organic carbon (TOC) are 134 x 10(12),12.69 x 10(12), 2.50 x 10(12), 1.01 x 10(12), 1.13 x 10(12), 8.05 x 10(12), 3.51 x 10(12) and 3.65 x 10(12) g x a(-1), respectively, and the erosion modulus of those compositions are 309 x 10(6), 28.98 x 10(6), 5.75 x 10(6), 2.27 x 10(6), 2.56 x 10(6), 18.4 x 10(6), 8.02 x 10(6) and 8.31 x 10(6) g x (km2 x a)(-1), respectively. Compared with average values of global large rivers, the erosion modulus of DOC, POC, and TOC in Pearl River basin are higher than the corresponding values.

Isotopic imprints of mountaintop mining contaminants.

Mountaintop mining (MTM) is the primary procedure for surface coal exploration within the central Appalachian region of the eastern United States, and it is known to contaminate streams in local watersheds. In this study, we measured the chemical and isotopic compositions of water samples from MTM-impacted tributaries and streams in the Mud River watershed in West Virginia. We systematically document the isotopic compositions of three major constituents: sulfur isotopes in sulfate (δ(34)SSO4), carbon isotopes in dissolved inorganic carbon (δ(13)CDIC), and strontium isotopes ((87)Sr/(86)Sr). The data show that δ(34)SSO4, δ(13)CDIC, Sr/Ca, and (87)Sr/(86)Sr measured in saline- and selenium-rich MTM impacted tributaries are distinguishable from those of the surface water upstream of mining impacts. These tracers can therefore be used to delineate and quantify the impact of MTM in watersheds. High Sr/Ca and low (87)Sr/(86)Sr characterize tributaries that originated from active MTM areas, while tributaries from reclaimed MTM areas had low Sr/Ca and high (87)Sr/(86)Sr. Leaching experiments of rocks from the watershed show that pyrite oxidation and carbonate dissolution control the solute chemistry with distinct (87)Sr/(86)Sr ratios characterizing different rock sources. We propose that MTM operations that access the deeper Kanawha Formation generate residual mined rocks in valley fills from which effluents with distinctive (87)Sr/(86)Sr and Sr/Ca imprints affect the quality of the Appalachian watersheds.