Operation of marine diesel engines on biogenic fuels: modification of emissions and resulting climate effects

The modification of emissions of climate-sensitive exhaust compounds such as CO(2), NO(x), hydrocarbons, and particulate matter from medium-speed marine diesel engines was studied for a set of fossil and biogenic fuels. Applied fossil fuels were the reference heavy fuel oil (HFO) and the low-sulfur marine gas oil (MGO); biogenic fuels were palm oil, soybean oil, sunflower oil, and animal fat. Greenhouse gas (GHG) emissions related to the production of biogenic fuels were treated by means of a fuel life cycle analysis which included land use changes associated with the growth of energy plants. Emissions of CO(2) and NO(x) per kWh were found to be similar for fossil fuels and biogenic fuels. PM mass emission was reduced to 10-15% of HFO emissions for all low-sulfur fuels including MGO as a fossil fuel. Black carbon emissions were reduced significantly to 13-30% of HFO. Changes in emissions were predominantly related to particulate sulfate, while differences between low-sulfur fossil fuels and low-sulfur biogenic fuels were of minor significance. GHG emissions from the biogenic fuel life cycle (FLC) depend crucially on energy plant production conditions and have the potential of shifting the overall GHG budget from positive to negative compared to fossil fuels.     

Saccharomyces cerevisiae strains AWRI 838, Lalvin EC1118 and Maurivin PDM do not produce excessive sulfur dioxide in white wine fermentations

The formation of sulfur dioxide (SO₂) by the related Saccharomyces cerevisiae strains AWRI 838, Lalvin EC11 18 and Maurivin PDM has been determined in white wines produced by laboratory-scale fermentation. Three different preparations of these strains, available for vinification in 1995, were indistinguishable based on production of SO₂. None of the physico-chemical factors investigated could stimulate an over-production of SO₂, and any changes in its concentration were independent of juice pH, sugar content, exposure to air, clarity, initial concentration of SO₂, and grape variety. Only fermentation without exposure to air could affect the concentration of SO₂, reducing it by 13–15% in the final wines. Under the conditions tested, changes in the concentration of SO₂ in wines produced with AWRI 838 and related strains would not account for wines which resist malolactic fermentation.     

Effects of variation of dietary sulfur on movement of sulfur in sheep rumen

Effects of variations in dietary sulfur on rumen sulfur dynamics were studied under steady state conditions. In the first experimental period, three sheep were given 33.3 g of a pelleted diet hourly containing 1.59 g sulfur/kg (low) and in the second period the sulfur content was increased to 3.21 g/kg (high) by the addition of sodium sulfate. The daily sulfur intake was 1.158 g on the low sulfur diet and .545 g of this passed from the rumen in protein, .614 g was calculated to be absorbed from the rumen as sulfide, and .052 g was estimated to be recycled to the rumen. For sheep with daily intakes of 2.317 g sulfur, 1.212 g passed from the rumen in protein, 1.078 g was absorbed from the rumen, and .093 g was estimated to be recycled. It was estimated that 127 and 165 g microbial protein were synthesized/kg organic matter "truly digested" in the rumen for low and high sulfur diets, respectively. A simple model using simultaneous equations was proposed to describe rumen sulfur metabolism.     

Nitrite and nitrate in fresh meats: a contribution to the estimation of admissible maximum limits to introduce in directive 95/2/EC

Nitrite and nitrate are food preservatives not allowed in fresh meat preparations. Two hundred fresh meat samples were analysed to evaluate the natural presence of nitrite and nitrate and estimate the maximum concentrations to considerate as ‘natural’ and to admit in fresh meat preparations. The analyses were carried out by a validated ion chromatography method, and the ‘positive’ samples were confirmed by an alternative ion chromatography method. Nitrite residues were not detected. Quantifiable nitrate concentrations, ranging from 10.2 to 36.5 mg kg^?1, were found in nineteen samples. In chicken meat samples, nitrate residues were not detected. Taking into account the distribution of nitrate concentrations, it is possible to suggest a maximum admissible limit of 30.0 mg kg^?1 in beef and pork meats; in equine meats, this limit may be increased to 40.0 mg kg^?1. Below these values, the samples can be considered as ‘compliant’.     

黄柠乳油在烤烟上的应用研究：Ⅰ.对烤烟某些生理效应的影响

在田间和盆栽条件下，研究了稀释浓度为４００、６００和８００倍黄柠乳油液在烤烟的光合速率、蒸腾速率、叶绿素含量和根系活力等方面的生理效应。结果表明，３种浓度都能提高叶片的光合速率和蒸腾速率，增加叶绿素含量和根鲜、干重，增强根系活力。以上生理效应在３种浓度之间存在显著或极显著差异，其中以６００倍液表现最佳，而４００倍液在烟株生长后期有一定的负效应。     

β-葡聚糖酶[EC. 3. 2. 1. 73]的研究 Ⅰ.产酶菌种的筛选和培养

β-葡聚糖酶主要用于啤酒工业,它能专一地分解粘度很高的各种大麦β-葡聚糖中β-1.3和β-1.4糖苷键,使麦汁粘度降低,从而缩短麦汁和啤酒的过滤时间,增加产量,并改善啤酒的质量。 试验所用菌种Bacillus Subtilis是从34株细菌中筛选并经诱变获得,它具有较高的产β-葡聚糖酶的能力。 在以淀粉、蔗糖和硫酸铵为主的培养基、pH7.2～7.5、温度为37℃条件下,进行搅拌通风培养两天。酶活力约为30U/ml。 发酵液采用絮凝剂处理,经硅藻土过滤,再将滤液经超滤或真空低温浓缩,即获得了深棕色的液体酶制剂。若进一步用酒精沉淀或进行喷雾干燥,即可制得粉末状酶制剂产品。 β-葡聚糖酶应用于啤酒糖化,对加速麦汁过滤、提高麦汁收得率,均有明显效果。     

A study on carbothermal reduction of sulfur dioxide to elemental sulfur using oilsands fluid coke

Experiments and reaction equilibrium calculations were carried out for the SO2 gas and oilsands fluid coke system. The goal was to develop a coke-based sulfur-producing flue gas desulfurization (SP-FGD) process that removes SO2 from flue gases and converts it into elemental sulfur. The conversion of SO2 to elemental sulfur proceeded efficiently at temperatures higher than 600 degrees C, and the sulfur yield reached a maximum (> 95%) at about 700 degrees C. An increase of temperature beyond 700 degrees C enhanced the reduction of product elemental sulfur, resulting in the formation of reduced sulfur species (COS and CS2), which lowered the sulfur yield at 900 degrees C to 90%. Although equilibrium calculations suggest that a lower temperature favors the conversion of SO2 as well as the yield of elemental sulfur, experiments showed no formation of elemental sulfur at 600 degrees C and below, likely due to hindered kinetics. Faster reduction of SO2 was observed at a higher temperature in the range of 700-1000 degrees C. A complete conversion of SO2 was achieved in about 8 s at 700 degrees C. Prolonging the product gas--coke contact, the yield of elemental sulfur decreased due to the formation of COS and CS2 while the SO2 conversion remained complete. Equilibrium calculations suggest that the ultimate yield of elemental sulfur maximizes at the C/SO2 ratio of 1, which represents the stoichiometry of SO2 + C-->CO2 + S. For the C/SO2 ratio < 1, equilibrium calculations predict elemental sulfur and CO2 being major products, suggesting that SO2 + C-->CO2 + S is the predominant reaction if SO2 is in excess. Experiments revealed that elemental sulfur and CO2 were only major products if the conversion of SO2 was incomplete, which is in agreement with the result of the equilibrium modeling.     

SO2对啤酒老化的影响

啤酒贮存过程中,易老化,测定SO2的变化情况,并对TBA值以及乙醛、双乙酰等风味物质的变化进行测定,经过分析发现,向啤酒中添加30mg/L SO2,啤酒TBA值降低了16.5%,啤酒RSV值与没有添加二氧化硫的啤酒相比提高了82.6%.说明添加二氧化硫可以有效地降低TBA值,提高啤酒的风味稳定性.     

Consequences of UK and EC Environmental Legislation on Textile Finishing

This paper considers the impact of textile products and processes on the environment, reviews previous UK legislation and regulation and considers how effective it was in controlling the environment, assesses the threats and opportunities that new UK and EC legislation pose to the finishing sector and suggests approaches that may be beneficial, both in environmental and commercial terms. This paper augments previous articles and papers written by the author on the impact of new environmental legislation on the UK Textile sector.     

48%"地乐辛醇"乳油对烟草腋芽的抑制效果

为验证 4 8 %“地乐辛醇”的抑芽效果 ,进行了田间药效试验。结果表明 :“地乐辛醇”乳油 10 0倍液在烟草上使用 1次 ,对腋芽有较好的抑制效果 ,抑芽率可达 95 2 3% ,与对照药剂“止芽素”相当 ,是一种经济高效的烟草抑芽剂。     

即食食品微生物限量标准比较分析

本文通过比较我国香港地区与国际食品法典委员会、欧盟、澳大利亚、新西兰、英国即食食品微生物限量标准,为制定我国的食品安全微生物标准提供技术依据.     

食品中挥发性硫化物的研究进展

挥发性硫化合物对食品中的特征风味或异味的产生具有重要的影响。该文综述了食品中挥发性硫化物的主要结构类型、性质、生成路径、提取方法和分析检测技术及其感官特性,为食品的风味特性、异味的研究及硫化物的深度开发利用提供参考。     

发酵火腿中微生物限量的问题探讨

确定发酵火腿中微生物的限量,对于保障其食用安全性和促进发酵火腿工业的发展具有重要意义.发酵火腿与中国传统的火腿不同之处在于发酵火腿可以生食.因而,发酵火腿必须设立微生物的限量.由于发酵火腿未经加热处理,其微生物限量应与熟肉制品有所区别.文章以熟肉制品中微生物的限量为参考,讨论发酵火腿中微生物限量的设定问题.食品中少量金黄色葡萄球菌的存在不会产生食品安全问题;发酵火腿中金黄色葡萄球菌的限量宜设为100 CFU/g,但不应设立菌落总数的限量.     

食物致敏原限量确定方法研究进展

食物中致敏原的管理是食品安全的重要内容之一,而食物致敏原限量对消费者、食品监管部门、企业都有着重要的实际意义,但食物致敏原限量却难以被严格、科学地确定。本文综述了欧盟、美国、澳大利亚以及日本等国家和组织食物致敏原限量的确定方法,并提出了我国食物致敏原限量确定的建议。     

20%安克力乳油在烟草和土壤中的残留研究

介绍了安克力(丙硫克百威)及其代谢物克百威、3-羟基克百威在烟草和土壤中的残留分析方法以及安克力在烟草中的消解动态和最终残留量.最终残留试验结果表明每667m2烟田施用安克力60ml(有效成分12g),设2次、3次施药,施药后15d时,干烟叶中安克力残留量均在2.44mg/kg以下.根据试验结果,建议在常量条件下,施药后的安全间隔期为15d.     

山楂片中二氧化硫脱除方法的研究

该试验以含硫山楂片为对象,研究了碱液浸泡、过氧化氢溶液浸泡、热水浸泡以及超声波处理对试样中二氧化硫脱除效果的影响。试验结果显示四种方法的脱硫效果均优于对照。频率40kHz,声强0.48w/cm^2的超声波处理的效果尤为显著,处理1h可使试样中二氧化硫残留量降至国家标准限量要求以下,并且对感官品质无不良影响;热水浸泡也可以显著加快脱硫速度,并与温度呈正相关,80℃浸泡2h或60℃浸泡4h,二氧化硫残留量符合国标要求,无明显煮熟味;过氧化氢溶液浸泡脱硫效果显著,但对其可能带来的潜在危害本实验未能做进一步的评估。