Windfalls for whom? The evolving notion of ‘community’ in community benefit provisions from wind farms

This paper investigates the increasing provision of ‘community benefits’ – i.e. financial or material benefits to communities affected by wind energy development – with a focus on on-shore wind projects in Wales. The paper argues that as community benefits are becoming more significant in scale, so pressures are mounting on what have hitherto been largely ad hoc arrangements for their disbursement. The paper finds that previously dominant definitions of communities as places directly affected by and within close proximity to wind farm development, are being challenged by the tendency to define ‘affected’ communities as broader entities characterised by more indirect and widely dispersed claims to benefit entitlement. This redefinition of the recipient community is causing conflict, much of it focused on debates about how community benefits should be governed. Evidence suggests that any re-scaling of relations around community benefits – from local compensation towards wider development goals – may be more consensually achieved in communities with previous experience in handling these funds, and where growing income streams allow multiple constituencies to be satisfied.     

Modeling methane emissions and methane inventories for cattle production systems in Mexico

Anaerobic fermentation of structural carbohydrates in the rumen of bovines produces waste products such as volatile fatty acids, fermentation heat, carbon dioxide and methane gas. Methane is a greenhouse gas having several times the global warming potential of CO₂. The purpose of the present paper is to provide a realistic estimate of the national inventory of methane produced by the enteric fermentation of cattle, based on a simulation model and to provide estimates of CH₄ produced by cattle fed typical diets from the tropical and temperate climates of Mexico. Predicted total emission of methane produced by the 23.3 million heads of cattle in Mexico is approximately 2.02 Tg/yr. It was concluded that the modeling approach was suitable in producing a better estimate of the national methane inventory for cattle. It is flexible enough to incorporate more cattle groups or classification schemes, productivity levels and a variety feed ingredients for cattle. The model could also be used to evaluate different mitigation strategies and serve as a tool to design mitigation policies.     

Kinetics analysis of the enzymatic hydrolysis of cellulose from straw stalk

The effects of several parameters on the simultaneous saccharification and fermentation of straw stalk for ethanol fuel production were investigated on the basis of orthogonal experiments. The parameters include temperature and time of fermentation, quantity and proportion of yeast inoculation, as well as cellulase dosage. An ethanol yield of 0.183 g/g was obtained from the straw stalk pretreated with diluted acid under determined optimum conditions. These conditions were: fermentation temperature: 38℃; fermentation time: 72 h; yeast inoculation quantity: 15%; yeast inoculation proportion: 2:1; and cellulose enzyme dosage: 20 U/g. The relationship between ethanol concentration c and fermentation time t is presented as follows, c=abt/(1+bt). The rate constant k of straw stalk hydrolysis by the cellulose enzyme depends on hydrolysis time, as described by k=k1t-h. Therefore, straw stalk hydrolysis reaction by the cellulose enzyme is fractal-like.     

Nitrogen and xenon in acid residues of iron meteorites

Total nitrogen, measured by neutron activation analysis, is highly enriched in residues from iron meteorites obtained by dissolution of the metal in dilute H₂SO₄, relative to the bulk value. On the average, the residues, representing 3% mass, contain 22% of total N. Group IA has more dissolved N than IIIA. Lithium and Ir show a distribution pattern parallel to N. Total Xe has been measured in several residues and its isotopic composition is, similar to atmospheric Xe for mass numbers 131 to 136 but not for ¹²⁴Xe and ¹²⁶Xe which are strongly depleted in the non-magnetic residues. It is suggested that iron meteorites have trapped in their micro-inclusions, some pre-solar nebular matter which is isotopically heterogeneous.     

Fractionation of stable carbon isotopes during anaerobic production and degradation of propionate in defined microbial cultures

In many anoxic environments propionate is, after acetate, the second most important fermentation product, being degraded further to finally result in CH₄ production. In principle, isotope discrimination can be used to assess the path of organic matter degradation to acetate, CO₂ and CH₄. However, nothing is known about the isotope fractionation in primary and secondary fermentation steps involving propionate, although it is an important precursor of acetate. We therefore studied the degradation of propionate with a syntrophic coculture of Syntrophobacter fumaroxidans and Methanobacterium formicicum. The isotope enrichment factor for propionate degradation to acetate, CO₂ and CH₄ was almost negligible (ε_prop 0.9‰). The fermentative production of propionate was studied in cultures with Opitutus terrae growing on pectin, xylan and starch. These polysaccharides were fermented to acetate, succinate, propionate, H₂ and CO₂. While the δ¹³C value of the initially produced propionate was similar to that of the organic substrates (ca. −28 to −25‰), the δ¹³C value of the other fermentation products was higher. The δ¹³C values of all products generally decreased during the course of fermentation. Finally, a small depletion in ¹³C (ca. 6‰) with respect to the organic substrate was observed for propionate, while the other fermentation products where slightly enriched. Overall, stable carbon isotope discrimination was small during both fermentative production and consumption of propionate in the anaerobic microbial cultures, so that propionate turnover probably only marginally affects isotope fractionation during anaerobic degradation of organic matter.     

Estimation of the local financial costs of flood damage with different methodologies in Unye (Ordu), Turkey

The aim of this study was to conduct flood analysis with digital modeling systems and estimate the total flood damage in a built-up area. The Ceviz Stream basin, which is located in Unye (Ordu) district in the Eastern Black Sea region of Turkey, was selected as the study area. A 1D/2D coupled flood modeling software MIKE FLOOD was used in flood analysis. According to the modeling results, water depth and velocity maps are produced for maximum Q₅₀, Q₁₀₀, Q₅₀₀ and Q₁₀₀₀ discharge scenarios in the most downstream section of the Ceviz Stream. At the projected Q_50, Q₁₀₀, Q₅₀₀ and Q₁₀₀₀ maximum flow rates, approximately 9.75%, 23.0%, 30.0% and 32.25% of that section of the study area were estimated to be negatively affected by floodwaters. In order to examine the financial magnitude of the effects of flooding, the Huizinga, van Eck and Kok, ICBR and Pistrika and Jonkman damage estimation methodologies were applied, with the highest financial costs estimated with the Pistrika and Jonkman method.

     

Investigation of zinc extraction from different leach residues by acid leaching

With different properties, zinc is one of the most important non-ferrous metals and it is used in various application areas, especially as an anti-corrosion agent. In Turkey, zinc production was based on zinc carbonate ores (ZnCO₃), at Çinkur plant from establishment to 1997 due to high reserves of zinc carbonate. After that, zinc concentrate coming from Iran was used in this plant over the last two decades. Thus, two different leach residues called as Turkish leach residue (TLR) and Iranian leach residue (ILR) were accumulated more than one million ton in Çinkur stock piles. In this study, it is aimed to investigate zinc recovery for each leach residue by use of sulphuric acid (H₂SO₄) and to compare the TLR and the ILR. Initially, detailed chemical, mineralogical and thermal analyses of these different leach residues were carried out. In order to investigate the effect of acid concentration and reaction duration on zinc recovery, leaching experiments were carried out at following conditions: 95 °C, 100 g/L pulp density and 600 rpm stirring rate. According to the characterization results, the chemical compositions for both residues are nearly similar; however, experimental results show that zinc recovery per cent of the ILR was higher than that of TLR for all experimental durations and acid concentrations. This may be due to the presence of Zn-containing compounds in the both residues at different percentages.     

On the Origin of Petroleum Hydrocarbon Gases

The compositional variation of oil-soluble gaseous hydrocarbons in high-pressure in-place oil from more than 40 oil wells in the Northern Jiangsu oil field, China, was studied. Samples in which the effects of the factors of pressure and biodegradation had been got rid of were chosen as the representatives that could really reflect the original composition of hydrocarbon gases. Such samples were compared compositionally with their corresponding hydrocarbons formed by decarboxylation of volatile low-molecular fatty acids. Thus highly correlative regularities were found to exist between them. The numerical values of both are graphically expressed. The two curves on the diagram are very similar. These two sets of values have a simple correlation coefficient of 0.9935, which presents their genetic relation.Based on the study of the formation of gaseous hydrocarbons from decarboxylation of volatile fatty acids, the following regularities of the isomers are revealed:1) n-butyric acid + isobutyric acid = propane:2) 1 2 isopentanoic acid(2-methyl-butyric acid) + n-pentanoic acid = n-butane; and3) 1 2 isopentanoic acid(3-methyl-butyric acid) = isobutane.The thermodynamics of decarboxylation was analysed and the enthalpy change △H, entropy change △S and Gibbs free energy change △G in the following reaction were calculated:CH_3COOH(1)--CH_4(g) + CO_2(g).Thus the author considers that the reaction for the formation of hydrocarbons due to the decarboxylation of fatty acids is an exothermic one with increased entropy and decreased free energy as well as a spontaneous one. According to the CRC rule, the resultant Gibbs free energy change △G is approximately-41.84 kJ/mol, which is well within the range of the energy levels of biophysiological changes.According to the changes in odd-carbon preference in n-alkanes of petroleum and sediments and the analysis of fatty acids and amino acids, it is considered that hydrocarbon gases do not originate from pyrolysis or thermal degradation but from decarboxylation of organisms. But this biological reaction is not ordinary biochemical reaction in the artificial fermentation for generating marsh gas. On the basis of the change tendency of the fatty acid content in the fermentation liquor for marsh gas generation and the change tendency of the carbon isotopes in methane and carbon dioxide in the marsh gas, it can be judged that the biochemical reaction for forming hydrocarbon gases is a special biological one occurring after the fermentation.     

王水溶样-氢醌容量法测定碳酸盐地质样品中的金

应用王水溶样-活性炭富集金-氢醌容量法测定岩石、土壤等一般地质样品中的金时,王水溶样后经布氏漏斗抽滤后剩余的不溶物残渣中金含量小于金总量的4%,通常不计入分析结果。而碳酸盐地质样品经焙烧后在王水溶解过程中因为钙和镁的硅酸盐含量较高,形成了不溶于王水的二氧化硅凝胶及大量钙镁胶状物,包裹和吸附样品溶液中的金,造成分析过程中金的损失。本文将抽滤后的滤液和不溶物残渣分别处理,收集王水分解样品抽滤步骤后的不溶物残渣,用氢氟酸-硫酸除硅,王水溶解测定残渣中的金含量,滤液和残渣两次测试合量为样品中金含量。实验研究了不溶物残渣中的金量、金的来源以及样品中硅钙镁的含量对金测定的影响。结果表明,不溶物残渣吸附和包裹的金量占样品金总量的18%~22%,残渣中金的主要来源是已被王水溶解但被二氧化硅等胶状物包裹吸附而未进入溶液的金,其次是未被王水溶解的单质金。胶状物的形成与样品中钙镁硅含量有直接的关系,当CaCO₃、MgCO₃含量达到30%以上时,必须考虑残渣中的金,以保证金的测试结果准确。     

Alginate biopolymer production by Azotobacter chroococcum from whey degradation

The potential of three Azotobacter chroococcum strains for whey degradation and alginate production were investigated. After dilution, samples were spread plated on isolation agar and Manitol agar and incubated at 30 °C for 24 h. Microorganisms were screened for their ability to whey degradation and alginate production based on colony morphology, negative and capsule staining, ability to decrease the apparent turbidity of the fermentation broths in batch and semi continuous culture by spectrophotometer assay at 400 nanometer and tensiometer assay. Of the three strains tested for whey degradation, only Azotobacter chroococcum 1723 produced significant apparent growth on whey broth and could decrease about 70 % of turbidity in fermentation broth during 6 days in batch culture. Colonies of this strain was characteristically yellow, large, moucoid and slimy on whey agar than Manitol agar after 24 h at 30 °C. Transmission electron microscopy assay and Carbazole reagent were used to recognize the alginate biopolymer. After optimizing environmental factors such as pH, salt concentration and temperature, this strain was able to produce exopolysaccharide greater than 5 mg/mL. Optimum results were obtained when using whey broth as a fermentation medium without extra salt, temperature at 35 °C and pH 7. Increasing inorganic and organic nitrogen sources (yeast extract and NH₄NO₃) reduced whey degradation at least 30%. Transmission electron microscopy assay showed a net-structured polysaccharide capsule around the cells. Semi-continuous culture results demonstrated that, alginate production as well as whey degradation was decreased (1 mg/mL and 30 %).     

Degradation of dissolved organic monomers and short-chain fatty acids in sandy marine sediment by fermentation and sulfate reduction

The decay of a wide range of organic monomers (short-chain volatile fatty acids (VFA’s), amino acids, glucose and a pyrimidine) was studied in marine sediments using experimental plug flow-through reactors. The reactions were followed in the presence and absence of 10 mM SO₄²⁻. Degradation stoichiometry of individual monomers (inflow concentration of 6 mM organic C) was traced by measuring organic (VFA’s, amino acids) and inorganic (CO₂, NH₄⁺, SO₄²⁻) compounds in the outflow. Fermentation of amino acids was efficient and complete during passage through anoxic sediment reactors. Aliphatic amino acids (alanine, serine and glutamate) were primarily recovered as CO₂ (24-34%), formate (3-22%) and acetate (41-83%), whereas only ∼1/3 of the aromatic amino acid (tyrosine) was recovered as CO₂ (13%) and acetate (20%). Fermentation of glucose and cytosine was also efficient (78-86%) with CO₂ (30-35%), formate (3%) and acetate (28-33%) as the primary products. Fermentation of VFA’s (acetate, propionate and butyrate), on the other hand, appeared to be product inhibited. The presence of SO₄²⁻ markedly stimulated VFA degradation (29-45% efficiency), and these compounds were recovered as CO₂ (17% for butyrate to 100% for acetate) and acetate (51% and 82% for propionate and butyrate, respectively). When reaction stoichiometry during fermentation is compared with compound depletion during sulfate reduction, the higher proportion CO₂ recovery is consistent with lower acetate and formate accumulation. Our results therefore suggest that fermentation reactions mediate the initial degradation of added organic compounds, even during active sulfate reduction. Fermentative degradation stoichiometry also suggested significant H₂ production, and >50% of sulfate reduction appeared to be fuelled by H₂. Furthermore, our results suggest that fermentation was the primary deamination step during degradation of the amino acids and cytosine.     

Carbon isotope effects associated with mixed-acid fermentation of saccharides by Clostridium papyrosolvens

In anoxic environments, microbial fermentation is the first metabolic process in the path of organic matter degradation. Since little is known about carbon isotope fractionation during microbial fermentation, we studied mixed-acid fermentation of different saccharides (glucose, cellobiose, and cellulose) in Clostridium papyrosolvens. The bacterium was grown anaerobically in batch under different growth conditions, both in pure culture and in co-culture with Methanobacterium bryantii utilizing H₂/CO₂ or Methanospirillum hungatei utilizing both H₂/CO₂ and formate. Fermentation products were acetate, lactate, ethanol, formate, H₂, and CO₂ (and CH₄ in methanogenic co-culture), with acetate becoming dominant at low H₂ partial pressures. After complete conversion of the saccharides, acetate was ¹³C-enriched (α_sacc/ac = 0.991-0.997), whereas lactate (α_sacc/lac = 1.001-1.006), ethanol (α_sacc/etoh = 1.007-1.013), and formate (α_sacc/form = 1.007-1.011) were ¹³C-depleted. The total inorganic carbon produced was only slightly enriched in ¹³C, but was more enriched, when formate was produced in large amounts, as ¹²CO₂ was preferentially converted with H₂ to formate. During biomass formation, ¹²C was slightly preferred (α_sacc/biom ≈ 1.002). The observations in batch culture were confirmed in glucose-limited chemostat culture at growth rates of 0.02-0.15 h⁻¹ at both low and high hydrogen partial pressures. Our experiments showed that the carbon flow at metabolic branch points in the fermentation path governed carbon isotope fractionation to the accumulated products. During production of pyruvate, C isotopes were not fractionated when using cellulose, but were fractionated to different extents depending on growth conditions when using cellobiose or glucose. At the first catabolic branch point (pyruvate), the produced lactate was depleted in ¹³C, whereas the alternative product acetyl-CoA was ¹³C enriched. At the second branch point (acetyl-CoA), the ethanol formed was 15.6-18.6‰ depleted in ¹³C compared to the alternative product acetate. At low hydrogen partial pressures, as normally observed under environmental conditions, fermentation of saccharides should mainly result in the production of acetate that is only slightly enriched in ¹³C (<3‰).     

Financially Efficient Ore Selections Incorporating Grade Uncertainty

Traditional mining selection methods focus on local estimates or loss functions that do not take into account the potential diversification benefits of financial risk that is unique to each location. A constrained efficient set model with a downside risk function is formulated as a solution. Estimates of this nonlinear mixed-integer combinatorial optimization problem are provided by a simulated annealing heuristic. A utility framework that is congruent with the proposed efficiency model is then used to choose the optimal set of local mining selections for a decision-maker with specific risk-averse characteristics. The methodology is demonstrated in a grade control environment. The results show that downside financial risk can be reduced by around 33% while the expected payoff is only reduced by 1% when compared to ore selections generated by traditional cut-off grade techniques.     

The concentration and isotopic composition of hydrogen,carbon and nitrogen in carbonaceous meteorites

Concentrations and isotopic compositions were determined for H₂, N₂ and C extracted by stepwise pyrolysis from powdered meteorites, from residues of meteorites partially dissolved with aqueous HF, and from residues of meteorites reacted with HF-HCl solutions. The meteorites treated were the carbonaceous chondrites, Orgueil, Murray, Murchison, Renazzo and Cold Bokkeveld. Data determined for whole rock samples are in approximate agreement with previously published data. Acidification of the meteorites removed the inorganic sources of H₂, so that H₂ in the HF-HCl acid residues came primarily from insoluble organic matter, which makes up 70–80% fraction of the total carbon in carbonaceous meteorites. The δD in the organic matter differs markedly from previously determined values in organic matter in meteorites. The δD values of organic matter from acid residues of C1 and C2 carbonaceous chondrites range from +650 to + 1150%. The acid residues of the Renazzo meteorite, whose total H₂ has a δD of +930‰, gave a δD value of +2500‰. Oxidation of the HF-HCl residue with H₂O₂ solution removes the high δD and the low δ¹⁵N components. The δ¹³C values range between ?10 and ?21 and δ¹⁵N values range between +40 and ?11. The δ¹⁵N of Renazzo is unusual; its values range between +150 and ?190.There is good correlation between δD and the concentration of H₂ in the acid residues, but no correlation exists between δD, δ¹³C and δ¹⁵N in them. A simple model is proposed to explain the high δD values, and the relationships between δD values and the concentration of H₂. This model depends on the irradiation of gaseous molecules facilitating reaction between ionic molecules, and indicates that an increase in the rate of polymerization and accumulation of organic matter on grains would produce an increase in the deuterium concentration in organic matter.     

The Ronda high temperature peridotite: Geochemistry and petrogenesis

The Ronda peridotite in southern Spain is a large (~300 km²) exposure of upper mantle which provides direct information about mantle processes on a scale much larger than that provided by mantle xenoliths in basalt. Ronda peridotites range from harzburgite to lherzolite, and vary considerably in major element content, e.g., Al₂O₃ from 0.9 to 4.8%, and trace element abundances, e.g., Sr, Zr and La abundances vary by factors of 20 to 40. These compositional variations are systematic and correlate with (pyroxene + garnet)/olivine ratios and olivine compositions. The data are consistent with formation of residual peridotites by variable degrees of melting (~0 to 30%) of a compositionally homogeneous peridotite. None of the peridotites have geochemical characteristics of residues formed by extensive (?5%) fractional melting and the data can be explained by equilibrium (batch) melting, possibly with incomplete melt segregation in some samples. Based on compositional differences between Ronda peridotites, the segregated melts were picritic (12–22% MgO) with relative rare earth element abundances similar to mid-ocean ridge basalt (MORB). Prior to the melting event the Ronda peridotite body was a suitable source for MORB. The compositional characteristics of Ronda peridotites are consistent with diapiric rise of a fertile mantle peridotite with relatively small degrees of melting near the diapir-wall rock interface yielding residues of garnet iherzolite, and larger degrees of melting in the diapir interior yielding residues of garnet-free peridotite. Subsequently these residual rocks were recrystallized at sub-solidus conditions (Obata, 1980), and emplaced in the crust by thrusting (Lundeen, 1978).     

Groundwater in-situ generation of aquatic humic and fulvic acids and the mineralization of sedimentary organic carbon

In this paper the groundwater in-situ generation of dissolved organic carbon (DOC) is discussed based on the origin of groundwaters, their physico-chemical and isotopic properties, chemical composition and the dissolved inorganic carbon (DIC) concentration and its ¹³C content. Three aquifer systems are investigated. Two of these have relatively well defined hydrological and geochemical conditions (Fuhrberg and Munich) and are used as reference systems. The third aquifer (Gorleben) is a complex system containing DOC concentrations up to 200 mg C/L in deep groundwaters. From this aquifer system 19 groundwaters from different hydrogeochemical conditions are analyzed. The in-situ generation of DOC is found to occur in conjunction with the microbiologically mediated mineralization of sedimentary organic carbon (SOC). Thereby, SO₄ is reduced and phosphate is released into the groundwater. Where SO₄ is depleted, the mineralization of SOC occurs via fermentation, resulting in CH₄ generation.     

Energetics of potential heterotrophic metabolisms in the marine hydrothermal system of Vulcano Island, Italy

Values of overall Gibbs free energy of 144 organic oxidation (respiration) and disproportionation (fermentation) reactions are calculated at the temperatures and chemical compositions that exist in nine submarine vents, sediment seeps and geothermal wells in the hydrothermal system of Vulcano Island, Italy. The organic compounds considered here include four carboxylic acids (formic, acetic, propanoic and lactic), two C₅ aldoses (arabinose and xylose), three C₆ aldoses (galactose, glucose and mannose), and 15 protein-forming amino acids (Ala, Arg, Asp, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Ser, Thr, Tyr, and Val). Oxidation of these compounds is coupled to five redox pairs: O₂/H₂O, , S⁰/H₂S, and Fe₃O₄/Fe²⁺. Energy yields from potential respiration reactions range from 6 to 118 kJ/mol of electrons transferred and show systematic behavior with respect to the terminal electron acceptor. Overall, respiration with O₂ yields the most energy (98–118 kJ/mol e⁻), followed by reactions with (53– 86 kJ/mol e⁻), magnetite (29–91 kJ/mol e⁻), S⁰ (11–33 kJ/mol e⁻) and (6–34 kJ/mol e⁻). Energy yields show little correlation with organic compound family, but are correlated with fluid pH. Variability in energy yields across the nine sites is greatest for Fe(III) reduction and is primarily influenced by pH and the activity of Fe²⁺. In addition to the potential respiration reactions, the energetics of 24 potential fermentation reactions are also calculated. As expected, fermentation reactions generally yield much less energy than respiration. Normalized to the number of moles of carbon transferred, fermentation yields−8 to 71 kJ/mol C, compared with 16 to 531 kJ/mol C for respiration reactions. All respiration and fermentation reactions, except for methionine (Met) fermentation, are exergonic under the in situ hydrothermal conditions and represent a plethora of potential metabolisms for Vulcano’s diverse thermophilic heterotrophs.     

Thermal degradation of rye and maize straw: Lipid pattern changes as a function of temperature

Future climatic conditions may coincide with an increased potential for wildfires in grassland and forest ecosystems, whereby charred biomass would be incorporated into soils. Molecular changes in biomass upon charring have been frequently analysed with a focus on black carbon. Aliphatic and aromatic hydrocarbons, known to be liberated during incomplete combustion of biomass have been preferentially analysed in soot particles, whereas determinations of these compounds in charred biomass residues are scarce. We discuss the influence of increasing charring temperature on the aliphatic and aromatic hydrocarbon composition of crop grass combustion residues. Straw from rye, representing C₃ grasses and maize, representing C₄ grasses, was charred in the presence of limited oxygen at 300, 400 and 500 °C. Typical n-alkane distribution patterns with a strong predominance of long chain odd-numbered n-alkanes maximising at C₃₁ were observed in raw straw. Upon combustion at 300 °C aliphatic hydrocarbons in char were dominated by sterenes, whereas at 400 °C sterenes disappeared and medium chain length n-alkanes, maximising around n-C₂₀, with a balanced odd/even distribution were present. At a charring temperature of 500 °C n-alkane chain length shifted to short chain homologues, maximising at C₁₈ with a pronounced predominance of even homologues. Even numbered, short chain n-alkanes in soils may thus serve as a marker for residues of charred biomass. Aromatic hydrocarbons indicate an onset of aromatization of biomass already at 300 °C, followed by severe aromatization upon incomplete combustion at 400–500 °C. The diagnostic composition of aliphatic and aromatic hydrocarbons from charred biomass affords potential for identifying residues from burned vegetation in recent and fossil soils and sediments.     

In-use energy and CO<Subscript>2</Subscript> emissions impact of a plug-in hybrid and battery electric vehicle based on real-world driving

Facilitated by fuel economy, climate legislation and government policy, sales of light-duty plug-in hybrid and battery electric vehicles are rapidly increasing during the last decade. But their energy and emissions impact have not been fully investigated, particularly accounting for energy and emissions during electricity generation. In this study, we conducted in-use energy consumption and emissions measurements of a plug-in and a battery electric vehicle under real-world city and highway driving conditions. We further compare them with energy consumption and emissions from counterpart conventional vehicles under the same driving conditions, to exclude benefits due to different vehicle specifications. Our results show that both the plug-in hybrid and battery electric vehicles can achieve about 50% energy benefits compared with their counterpart conventional vehicles, mainly through capturing regenerative energy. But when vehicles are tested in high-speed or high-acceleration driving conditions, the distance-normalized life-cycle CO₂ emissions of plug-in hybrid and battery electric vehicles are higher to their counterpart gasoline powered vehicles. The CO₂ emissions comparison results can vary based on the location and time of electricity generation. Therefore, our results confirm that benefits of promoting electric vehicles should consider temporal and spatial aspects of electricity generation.     

Variable190Os/184Os ratio in acid residues of iron meteorites

In residual materials obtained on dissolution of iron meteorites in 2M H₂SO₄, the ratio of¹⁹⁰Os/¹⁸⁴Os has been measured by radiochemical neutron activation analysis. Most residues have a normal isotopic ratio (to within ±2%). However, in some residues both positive and negative deviations in the isotopic ratio are seen. The most spectacular deviations are in the insoluble fragments (nuggets) from Sikhote Alin iron meteorite where the¹⁹⁰Os/¹⁸⁴Os ratio is about 50% of the normal value. The new results confirm our earlier observations that iron meteorites contain pre-solar grains.