While carbon capture and storage (CCS) is considered to be critical to achieving long-term climate-protection goals, public concerns about the CCS practice could pose significant obstacles to its deployment. This study reports findings from the first state-wide survey of public perceptions of CCS in a coal-intensive state, with an analysis of which factors predict early attitudes toward CCS. Nearly three-quarters of an Indiana sample (N = 1001) agree that storing carbon underground is a good approach to protecting the environment, despite 80% of the sample being unaware of CCS prior to participation in the two-wave survey. The majority of respondents do not hold strong opinions about CCS technology. Multivariate analyses indicate that support for CCS is predicted by a belief that humankind contributes to climate change, a preference for increased use of renewable energy, and egalitarian and individualistic worldviews, while opposition to CCS is predicted by self-identified political conservatism and by selective attitudes regarding energy and climate change. Knowledge about early impressions of CCS can help inform near-term technology decisions at state regulatory agencies, utilities, and pipeline companies, but follow-up surveys are necessary to assess how public sentiments evolve in response to image-building efforts with different positions on coal and CCS. 相似文献
The catabolism by human faecal microbiota of (–)‐epicatechin ( 1 ) (2, 3‐cis stereochemistry) and its dimer pure procyanidin B2 ( 2 ), has been compared using a static in vitro culture model. The catabolites were characterised by LC‐MSn, UV absorption and relative retention time, and quantified relative to standards. No more than ~10% of procyanidin B2 ( 2 ) was converted to epicatechin ( 1 ) by scission of the interflavan bond. Five phenolic acid catabolites (Mr<290) were unique to 2 , and ten phenolic acid catabolites (Mr<290) were common to both substrates. The dominant catabolites (≥24 h incubation) were 5‐(3′‐hydroxy phenyl) valeric acid ( 9 ), 3‐(3′‐hydroxyphenyl) propionic acid ( 10 ) and phenyl acetic acid ( 12 ) (maximum yields 27.4±4.2, 38.2±4.2, 22.7±2.9%, respectively, from 1 and 9.4±1.2, 52.8±2.1, 28.8±1.6%, respectively, from 2 ). Substrate 2 was degraded twice as rapidly as 1 . Evidence is presented for the production of previously unreported catabolites of 2 that retain the flavanol A‐ring and the C4→C8 interflavan bond. It was confirmed that catabolism favoured removal of the 4′‐hydroxyl rather than the 3′‐hydroxyl group and that both β‐oxidation and α‐oxidation occurred. 相似文献
Sources and risk factors for contamination, survival, persistence, and heat resistance of Salmonella in low-moisture foods are reviewed. Processed products such as peanut butter, infant formula, chocolate, cereal products, and dried milk are characteristically low-water-activity foods and do not support growth of vegetative pathogens such as Salmonella. Significant food safety risk might occur when contamination takes place after a lethal processing step. Salmonella cross-contamination in low-moisture foods has been traced to factors such as poor sanitation practices, poor equipment design, and poor ingredient control. It is well recognized that Salmonella can survive for long periods in low-moisture food products. Although some die-off occurs in low-moisture foods during storage, the degree of reduction depends on factors such as storage temperature and product formulation. The heat resistance of Salmonella is affected by many factors, mostly by strain and serotypes tested, previous growth and storage conditions, the physical and chemical food composition, test media, and the media used to recover heat-damaged cells. Salmonella heat resistance generally increases with reducing moisture. Care must be taken when applying published D- and z-values to a specific food process. The product composition and heating medium and conditions should not be significantly different from the product and process parameters used by the processors. 相似文献
Chemical and mechanical experiments are reported to elucidate the macroscopic effects of crosslinker length and composition on the thermomechanical response of acrylate‐based SMPs. To this end, EGA‐based formulations underwent a battery of basic tests which revealed that by increasing crosslinker chain length, polymer Tg can be decreased but there will be increases in compliance, step recoverability, and damping in a glassy state. Addition of methacrylate groups can cause increases in swelling, Tg, storage modulus in shorter chains, and greater damping at a rubbery state. All tested polymers exhibited mild hydrophilicity. PEGDA formulations exhibited good recoverability and could be an option for vascular applications.
Carbon based electrodes are widely used for in vivo and in vitro electrochemical studies. In particular, monoamine neurochemistry has been investigated using carbon microfibre electrodes. Similarly, glassy carbon (GC) is the preferred material for many biochemical applications, such as electrochemical detection in chromatography. More recently, boron doped diamond (BDD) has been utilized for biosensing, as its carbon sp3 structure is expected to provide better resistance to analyte fouling. However, the main factor limiting the use of electrochemical sensors for biological studies is the effect of the biological matrix. Indeed, in vivo or in situ measurements expose the sensor to a complex matrix of proteins, which adsorb on the sensing surface and interfere with the electrochemical measurements.Here, we compare the performance of three carbon based electrodes: GC, GC with low surface oxides and BDD. The redox species ruthenium(III) hexaammine (outer-sphere), ferrocyanide (surface sensitive) and the biologically significant dopamine have been investigated in protein and blood-mimicking matrices. Cyclic voltammetry and electrochemical impedance spectroscopy have been used to examine the effect of spectator molecules and reaction products on electrode mechanisms.Our results show that BDD generally exhibits the best performance for most conditions and reactions and should therefore be preferred for measurements in biologically fouling environments. Furthermore, surface oxides seem also to improve resistance of the GC electrode to biofouling. 相似文献
Survival rates and productive herd life were examined for 13.8 million US dairy cows that calved from January 1, 1980, through March 2, 2005. Cows that left the herd for dairy purposes or were from herds that discontinued Dairy Herd Improvement testing were excluded from any calculations to prevent underestimation of population longevity. Mean lactation length for cows without subsequently recorded lactations ranged from 205 to 235 d across breed-parity subsets and were 4 to 29 d longer for parities 2 through 7 than for parity 1. Mean survival rates were 73% to parity 2; 50% to parity 3; 32% to parity 4; and 19, 10, 5, and 2% to parities 5 through 8, respectively. The mean number of parities for Holsteins declined from 3.2 for those first calving in 1980 to 2.8 for those first calving in 1994. Mean numbers of parities for other breeds first calving in 1994 were 2.9 for Ayrshires and Brown Swiss, 2.4 for Guernseys, and 3.2 for Jerseys. Breed means for productive herd life (through parity 8) ranged from 28 to 36 mo. All regressions of mean number of parities or mean productive herd life on year were negative. The trend for decline of many of those indicators of longevity slowed or ended after the early 1990s. Between 31 (Jersey) and 39% (Guernsey) of herds were made up of first-calf heifers. 相似文献
Batteries, fuel cells and solar cells, among many other high-current-density devices, could benefit from the precise meso- to macroscopic structure control afforded by the silica sol-gel process. The porous materials made by silica sol-gel chemistry are typically insulators, however, which has restricted their application. Here we present a simple, yet highly versatile silica sol-gel process built around a multifunctional sol-gel precursor that is derived from the following: amino acids, hydroxy acids or peptides; a silicon alkoxide; and a metal acetate. This approach allows a wide range of biological functionalities and metals--including noble metals--to be combined into a library of sol-gel materials with a high degree of control over composition and structure. We demonstrate that the sol-gel process based on these precursors is compatible with block-copolymer self-assembly, colloidal crystal templating and the St?ber process. As a result of the exceptionally high metal content, these materials can be thermally processed to make porous nanocomposites with metallic percolation networks that have an electrical conductivity of over 1,000 S cm(-1). This improves the electrical conductivity of porous silica sol-gel nanocomposites by three orders of magnitude over existing approaches, opening applications to high-current-density devices. 相似文献
Quantum dots that contain cadmium, selenium and zinc are not toxic to monkeys for periods of up to 90 days, but longer-term studies are needed to determine the ultimate fate of the heavy metals that accumulate in the organs. 相似文献