Microbiological,physico-chemical and organoleptic attributes of a country tomato salad and fate of Salmonella enteritidis during storage under aerobic or modified atmosphere packaging conditions at 4°C and 10°C

The effect of initial head spaces of air and 5%CO₂/95%N₂, on the microbial flora of tomato salad (Greek style) was studied at 4°C and 10°C. The microbial flora of tomatoes comprised of lactic acid bacteria, pseudomonads and yeasts. Lactic acid bacteria were the predominant organisms in all samples. The pH dropped during the storage of country salad and this was more pronounced at 10°C. The concentration of different organic acids such as lactic, acetic, formic and propionic increased in all samples stored under modified atmosphere (MA) packaging conditions at both temperatures. The spoilage of tomatoes stored under 5%CO₂/95%N₂ was delayed, as indicated by the changes in their texture, color and odor, compared with those samples stored under air. When country salad was inoculated with Salmonella enteritidis, the pathogen survived but did not grow regardless of the packaging system used at both temperatures.     

Effect of gamma-ray and microwave treatment on the shelf-life of beef products stored at 5°C

The effect of gamma radiation and microwave treatments of different beef products were investigated with respect to survival and growth of bacteria, shelf-life, chemical content and sensory quality. When beef samples with an initial bacterial count of 4.9×10⁶ CFU/g were exposed to gamma rays at a dose level of 5.0 kGy, counts of bacteria were reduced by 2–3 log cycles and when heated in a microwave oven, bacterial counts were reduced by 1 log cycle in 20 s and by 2 log cycles in 30 s exposure. Untreated samples had a shelf-life of less than 7 days, whereas samples that were irradiated at a dose level of 3 kGy, then heated in microwave oven for 20 s had a shelf-life of at least 2 weeks at 5°C. Gamma-rays treatment had a very little effect on the odor and flavor of the pretreated sample. The combined treatment shows either no change or loss of thiamine levels and free fatty acids but increased the peroxide values during storage at 5°C. It was concluded that the combined treatment of gamma ray and microwave at lower levels can greatly enhance the microbial safety of beef products.     

Interaction of Chloride Salts and Kaolin Clay in the Hydrolysis of Emulsified Chloride Salts at 200–350°C

Abstract

The hydrolysis of chloride salts is an increasing problem in the refining of heavy crude oils and bitumens. The contributions of kaolin clay as a potential contaminant were evaluated by steaming mixed chloride salts and kaolin clay in a base oil. The amount of chloride released from the oil mixture increased from 1.21% to 4.50% with addition of clay. The same trends were observed with pure salts. By providing a large surface for deposition of salts from emulsified brine droplets, the fine solids in the oil increased the extent of reaction of chloride salts with steam.     

Development and Commercial Application of Supported Palladium Catalyst for Isomerization of C5/C6 Hydrocarbons

1 Introduction. China has enforced a new gasoline standard starting 2003 to limit the olefins, aromatics and benzene contents in gasoline. The isomcrate is the cleanest gasoline component because it does not contain the above-mentioned components, and is also an excellent gasoline blending component because of its higher RON and MON ratings. Currently the FCC naphtha accounts for 81.4% of gasoline pool, reformate accounts for 12.6% of gasoline pool, MTBE makes up 4% of gasoline pool.     

GENERALIZED KINEMATIC VISCOSITY-TEMPERATURECORRELATION FOR UNDEFINED PETROLEUM FRACTIONS OF IBP – 95°C TO 455°C+ BOILING RANGES

ABSTRACT

A generalized kinematic viscosity-temperature correlation for undefined petroleum fractions of all boiling ranges including 455^+°C fractions have been developed to represent the data for a wide range of temperature from 30 to 200°C. The correlation is based on experimental kinematic viscosity data for twenty TBP fractions of Arab heavy, Arab medium, Arab light and Arab extra-light crude oils. The proposed correlation has been found to fit all the eperimental data consisting of 248 measurements of the kinematic viscosity with an overall average absolute deviation of 9.07% compared to 15.47% given by ASTM method.     

煤制气工程用－60°C多功能塔的试制

介绍了煤制气工程用－６０℃低温多功能塔的技术参数、结构特点、材料选用及制造技术等。     

Analysis of Causes Leading to High Bromine Number of C8^＋ Aromatics and Short Clay Service Life and Countermeasures Proposed

After comparing the operating status of other catalytic reforming units and evaluation of the side-cut stream tests, the refinery investigated the influence of the feedstock property, clay types, and operating regime of the clay tower and catalytic reforming unit on the service life of the clay. Test results had revealed that the low potential aromatic content of the reformer feed and high operating severity were the critical causes leading to high bromine number of the C8^＋ aromatics feed for the PX unit and the shortened service life of clay. This article also puts forward the corresponding remedial measures.     

THE EXTRACTION OF COALS WITH PYRIDINE AND TOLUENE AT 350°C

ABSTRACT

The extraction of three coals with mixtures of toluene and pyridine at 350^°C were compared. The conversion of both the bituminous and sub-bituminous coals Increased as the amount of pyridine in the mixture Increased up to ca 60% pyridine at a constant gas density of 0.64 g/ml. However, there was no Improvement in conversion for the brown coal when toluene was replaced with pyridine. The difference between pyridine and toluene conversion decreased as the gas density decreased. The high solvent efficiency of pyridine is probably due to the unshared pair of electrons on the nitrogen atom. Addition of other compounds with an unshared pair of electrons on a nitrogen or an oxygen atom also Increased conversion In toluene supercritical gas extraction of a bituminous coal at 350^°C and a constant solvent density.     

从北纬53°到45°

漠大线管道寄托着管理者的无限眷恋。他们常年在寂寞中坚守，在特殊的地理环境中建起一座精神家园，成为我国管道运行中的独特风景。     

Synergistic effect of a combination of ultraviolet–C irradiation and sodium hypochlorite to reduce Listeria monocytogenes biofilms on stainless steel and eggshell surfaces

The present study demonstrates the synergistic effect of treatment with a combination of ultraviolet (UV)C (300, 600, 1200, and 1800 mWs/cm²) irradiation and sodium hypochlorite (NaOCl) (50, 100, 150, and 200 ppm) on Listeria monocytogenes ATCC 19113 biofilms formed on stainless steel and eggshell surfaces. The synergistic effect was not dependent on the dose of UV–C irradiation or the concentration of NaOCl. Synergistic reductions of biofilms after UV–C/NaOCl treatment on stainless steel and eggshells were 0.95–3.68 log CFU/cm² and –0.22 to 1.02 log CFU/cm², respectively. The largest synergistic reductions of biofilms were 3.68 log CFU/cm² using 1800 mWs/cm² UV–C and 200 ppm NaOCl on stainless steel, and 1.02 CFU/cm² using 600 mWs/cm² UV–C and 50 ppm NaOCl on eggshells. The Hunter colors of L*, a*, and b* were not significantly (P > 0.05) changed on eggshell surfaces treated with all single and combined treatments. The results in this study indicate that the combination treatment of 1800 mWs/cm² UV–C/200 ppm NaOCl could be feasible for use on stainless steel surfaces in industrial kitchens, facilities, and restaurants. In addition, the combination of 600 mWs/cm² UV–C/500 ppm NaOCl could possibly be used in egg production, processing, and distribution processes to enhance food safety without causing changes to the eggshell surface color.     

0°～60°定向井测井工艺

石明贤．０°～６０°定向井测井工艺．测井技术，１９９４，１８（ｌ）：２６～２９对常规测井工艺在定向斜井中遇到的问题进行分析．针对如何在０°～６０°的定向井中取全取准资料进行了研究。介绍了定向井测井工艺装备的技术指标，适用范围及使用效果。     

Current State and Future of Supply and Demand of Natural Gas in China

The implementation of the Twelfth-Five-Year-Plan of China has been halfway through by now and it iS thne for uS toprepare for the formulation of the next five-year-plan by clecking on how tire previous one has been going on and wltether it will be fulfilled in time. This arlicle tries to answer the question by choosing natural gas as a research subject. By analyzing the state quo of gas supply and demand, I am trying to predict how the plan for natural gas wiU be implemented by the end of the period so as to provide a reference for drafiing the Thirteenth-Five-Year-Plan.     

The Three-layer Structure and Systems of Petroleum Migration and Accumulation of Continental Basins

The concept of the three-layer structure of continental basins is presented based on the characteristics of layered structure of basins.The reservoir could be classified into accumulation system assemblage,accumulation system,accumulation assemblage and reservoir.This paper discusses the characteristics of hydrocarbon accumulation system assemblages of the Zhanhua Depression,which include four kinds of genetic patterns:(1)buried-hill hydrocarbon accumulation system assemblage; (2)self-sourced accumulation system assemblage from the upper interval of member 4 to member 1 of Shahejie formation;(3) transition accumulation system assemblage from member 1 of the Shahejie formation to Dongying formation and(4)externally sourced accumulation system assemblage in the late Tertiary.The hydrocarbon-source transport network layer consisted of faults and unconformities,which connected with the reservoir layer.     

6°带和3°带图形的叠加

文中阐述了高斯投影的原理,介绍了6°带和3°带分带情况、不同分带投影图形在AutoCAD中的叠加方法,以及具体的操作实例。     

KINEMATIC VISCOSITY-TEMPERATURE BEHAVIOR OF HEAVY TBP-FRACTIONS (455°C+) OF ARABIAN CRUDE OILS

ABSTRACT

A generalized kinematic viscosity-temperature correlation for undefined liquid heavy petroleum fractions has been developed to represent the data for a wide range of temperature from 100°C to 200°C. The correlation is based on the experimental kinematic viscosity data of true boiling point fractions of four Arabian crude oils. The characterization property required for estimation is 50% boiling point. The proposed correlation fits the experimental data with an overall absolute error of 6.1%. Experimental measurements of kinematic viscosity of heavy true boiling point fractions of Arabian crude oils were also obtained in order to develop the proposed correlation.     

The Combination Process for Manufacture of MTBE and Diisobutene Through C4 Olefins Polymerization Followed by Etherification

On March 3, 2006 the project ＂Combination Process for Manufacture of MTBE and Di-isobutylene through Ca Olefins Polymerization Followed by Etherification＂ performed jointly by RIPP and the Shijiazhuang Refining and Chemical Stock Company had passed in Beijing the technical appraisal organized by the Technology Development Division of Sinopec Corp.