Water footprint of U.S. transportation fuels

In the modern global economy, water and energy are fundamentally connected. Water already plays a major role in electricity generation and, with biofuels and electricity poised to gain a significant share of the transportation fuel market, water will become significantly more important for transportation energy as well. This research provides insight into the potential changes in water use resulting from increased biofuel or electricity production for transportation energy, as well as the greenhouse gas and freshwater implications. It is shown that when characterizing the water impact of transportation energy, incorporating indirect water use and defensible allocation techniques have a major impact on the final results, with anywhere between an 82% increase and a 250% decrease in the water footprint if evaporative losses from hydroelectric power are excluded. The greenhouse gas impact results indicate that placing cellulosic biorefineries in areas where water must be supplied using alternative means, such as desalination, wastewater recycling, or importation can increase the fuel's total greenhouse gas footprint by up to 47%. The results also show that the production of ethanol and petroleum fuels burden already overpumped aquifers, whereas electricity production is far less dependent on groundwater.     

Inventory development and input-output model of U.S. land use: relating land in production to consumption

As populations and demands for land-intensive products, e.g., cattle and biofuels, increase the need to understand the relationship between land use and consumption grows. This paper develops a production-based inventory of land use (i.e., the land used to produce goods) in the U.S. With this inventory an input-output analysis is used to create a consumption-based inventory of land use. This allows for exploration of links between land used in production to the consumption of particular goods. For example, it is possible to estimate the amount of cropland embodied in processed foods or healthcare services. As would be expected, agricultural and forestry industries are the largest users of land in the production-based inventory. Similarly, we find that processed foods and forest products are the largest users of land in the consumption-based inventory. Somewhat less expectedly this work finds that the majority of manufacturing and service industries, not typically associated with land use, require substantial amounts of land to produce output due to the purchase of food and other agricultural and wood-based products in the supply chain. The quantitative land use results of this analysis could be integrated with qualitative metrics such as weighting schemes designed to reflect environmental impact or life cycle impact assessment methods.     

美国肯塔基白肋烟生产过程中的保护耕作法应用进展

肯塔基大学长期以来一直在研究并推动中耕作物生产的保护耕作法。肯塔基的农民是世界上接受保护耕作大规模种植玉米和大豆的首批农户之一。保护耕作用于白肋烟生产的研究始于二十世纪七十年代早期,但此前烟农的兴趣始终不高。烟农不愿放弃传统的耕作方式,缺乏合适的移植机技术,对于控制杂草的担忧以及更多的是近来对于未来生产水平的不确定性使得采用保护耕作的进展减缓。二十世纪九十年代中期关于烟草的保护耕作研究再度恢复,引发了关于移植机,杂草控制的新概念的产生,包括作物的管理。本文将以一个个独立的研究结果演示考虑采用保护耕作的…     

Changing chemical composition of precipitation in Wilmington, North Carolina, U.S.A.: implications for the Continental U.S.A

The H+(aq) concentration in Wilmington, NC, precipitation has decreased by approximately 50% during the preceding two decades, similar to trends seen nationwide. The decrease in acidity is important because solution pH plays a key role in atmospheric reactions, and because the change is so large. This study presents the first long-range study of dissolved organic carbon (DOC) levels in precipitation which demonstrates that DOC concentrations have decreased by approximately half in Wilmington, NC, precipitation. The concentrations of H+(aq) and DOC are highly correlated primarily because small organic acids contribute to both DOC and H+(aq) in precipitation. Ammonium ion concentrations in precipitation have increased due to increased agricultural activities, and this also affects precipitation pH. The reduction of SO2 emissions in 1995 imposed by the Clean Air Act Amendment, better control of emissions of volatile organic compounds, and the increase in ammonia emissions all contribute to the decreasing H+(aq) in precipitation nationwide. These compositional changes in precipitation have many environmental implications, such as decreased acid deposition to lakes, changing speciation for trace metals in precipitation, increased ammonium deposition to coastal waters, and decreased DOC transport to the open ocean.     

Analysis of energy use and CO2 emissions in the U.S. refining sector, with projections for 2025

This analysis uses linear programming modeling of the U.S. refining sector to estimate total annual energy consumption and CO(2) emissions in 2025, for four projected U.S. crude oil slates. The baseline is similar to the current U.S. crude slate; the other three contain larger proportions of higher density, higher sulfur crudes than the current or any previous U.S. crude slates. The latter cases reflect aggressive assumptions regarding the volumes of Canadian crudes in the U.S. crude slate in 2025. The analysis projects U.S. refinery energy use 3.7%-6.3% (≈ 0.13-0.22 quads/year) higher and refinery CO(2) emissions 5.4%-9.3% (≈ 0.014-0.024 gigatons/year) higher in the study cases than in the baseline. Refining heavier crude slates would require significant investments in new refinery processing capability, especially coking and hydrotreating units. These findings differ substantially from a recent estimate asserting that processing heavy oil or bitumen blends could increase industry CO(2) emissions by 1.6-3.7 gigatons/year.     

Carbon emissions from U.S. ethylene production under climate change policies

This paper presents the results from a dynamic computer model of U.S. ethylene production, designed to explore implications of alternative climate change policies for the industry's energy use and carbon emissions profiles. The model applies to the aggregate ethylene industry but distinguishes its main cracker types, fuels used as feedstocks and for process energy, as well as the industry's capital vintage structure and vintage-specific efficiencies. Results indicate that policies which increase the cost of carbon of process energy-such as carbon taxes or carbon permit systems-are relatively blunt instruments for cutting carbon emissions from ethylene production. In contrast, policies directly affecting the relative efficiencies of new to old capital-such as R&D stimuli or accelerated depreciation schedules-may be more effective in leveraging the industry's potential for carbon emissions reductions.     

卷土重来的美国纺织投资热

新年伊始,日本东丽株式会社宣布,将向美国南卡州投资10亿美元,开发新型碳纤维材料.截至今日,成百亿上千亿的资金引发了美国纺织投资热.美国纺织权威比尔＆#183;史密斯先生深感诧异.他说,美国固然是世界上最大的纺织品贸易市场,又何以引发大量亚洲公司蜂拥而入？     

Distribution of Campylobacter spp. in selected U.S. poultry production and processing operations.

A study was conducted of 32 broiler flocks on eight different farms, belonging to four major U.S. producers. The farms were studied over I complete calendar year. Overall, 28 (87.5%) of the flocks became Campylobacter positive, and only four (12.5%) remained negative throughout the 6- to 8-week rearing period. In the majority of flocks, sampled every 2 weeks throughout production, Campylobacter-positive fecal and cecal samples were not detected until 4 to 8 weeks of age. In only six of the flocks were environmental samples found to be positive before shedding of Campylobacter was detected in the birds. Even in some of the Campylobacter-negative flocks, contamination of the rearing environment was positive for Campylobacter but did not result in the birds subsequently excreting the organism. These findings are discussed in relation to U.S. husbandry practices and present uncertainty about sources of Campylobacter infection for poultry flocks. Birds were often transported to the processing plant in coops that were already contaminated with Campylobacter, and the organisms were sometimes found in samples of scald water and chill water. After chilling, the proportions of Campylobacter-positive carcasses from different producers ranged from 21.0 to 40.9%, which is lower than in other studies, and possible reasons are considered.     

美国以100％废纸，利用“ATMOS”技术生产高档擦手纸产品

Wausau Paper公司推出了其新的Artisan高档擦手纸系列产品,产品的原纸来自该公司位于肯塔基州Harrodsburg纸厂的ATMOS（卫生纸先进成形系统）新技术纸机。Artisan擦手纸采用100％回用纤维,呈亮白色,非常结实,同时又很柔软且能彻底把手擦干。这种擦手纸外观洁净卫生,有似布的耐用性和强度,性能非常高。Artisan擦手纸产品质量上乘,同时还是绿色环保的。     

蜜汁山药

随着媒体与政府将关注点集中摆在肥胖症与健康议题上,某些人认为糖果工厂所蒙上的阴影更胜于巧克力工厂.但是美国人并不能、也并不会就此将糖果隔绝于生活之外.     

美国大豆食品

大豆是一种重要的农产品，近年来，其产量在美国和全世界都稳定增长。它具有很高的营养价值，其蛋白质和脂肪的含量很高，而且质量也很好。大豆还含有许多微量成分，其健康价值也是独一无二的。总体上讲，美国市场上的大豆食品可分为六个主要部分：豆油、传统大豆食品、大豆蛋白制品中，新一代大豆食品、大豆强化食品和功能性大豆成分。由于意识到了大豆食品的市场潜力，越来越多的大豆食品生产厂家和大豆的相关产品出现了，大豆食品有望成为21世纪世界上最普遍流行的食品。     

引进美国Mead OPAS公司无碳复写纸生产线生产实践

介绍了引进的美国Mead OPAS无碳复写纸涂布生产线的特点，技术规范，工作原理以及针对生产中出现的问题所采取的切实可行的措施。     

Perfluorinated compounds in human milk from Massachusetts, U.S.A

Perfluorinated compounds (PFCs), notably perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), have been reported in human blood. Furthermore, the occurrence of PFCs in the blood of newborn babies, coupled with the need to study the potential association of PFC exposure with birth outcomes in neonates, suggests the need for determining the sources and magnitude of exposure in infants. In this study, nine PFCs were measured in 45 human breast milk samples collected in 2004 from Massachusetts, U.S.A. PFOS and PFOA were the predominant PFCs found at mean concentrations of 131 and 43.8 pg/mL, respectively. Comparison of the ratio of PFOS to PFOA in human milk with the ratios published for human serum from the U.S. female population suggested preferential partitioning of PFOA to milk. Concentrations of PFOA were significantly higher in the milk of mothers nursing for the first time (n = 34) than in the milk of mothers who have previously nursed (n = 8). Based on the estimated body weight and milk intake, the average and highest daily intakes of total PFCs by infants were 23.5 and 87.1 ng/kg bw, respectively. We found that the daily ingestion rates of PFOS and PFOA did not exceed the tolerable daily intake recommended by the U.K. Food Standards Agency. This is the first study to measure the occurrence of PFCs in human milk from the U.S.A.