期刊文献+
共找到16篇文章
< 1 >
每页显示 20 50 100
Effect of Gum Arabic from Acacia senegal var. kerensis as an Improver on the Rheological Properties of Wheat Flour Dough
1
作者 Roseline Mwihaki Kiama Mary Omwamba +1 位作者 George Wafula Wanjala Symon Maina Mahungu 《Food and Nutrition Sciences》 CAS 2024年第4期298-312,共15页
Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to incre... Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to increasing consumer awareness, thus contributing to the rising demand for natural hydrocolloids. Gum Arabic from Acacia senegal var. kerensis is a natural gum exhibiting excellent water binding and emulsification capacity. However, very little is reported on how it affects the rheological properties of wheat dough. The aim of this study was therefore, to determine the rheological properties of wheat dough with partial additions of gum Arabic as an improver. Six treatments were analyzed comprising of: flour-gum blends prepared by adding gum Arabic to wheat flour at different levels (1%, 2% and 3%), plain wheat flour (negative control), commercial bread flour and commercial chapati flour (positive controls). The rheological properties were determined using Brabender Farinograph, Brabender Extensograph and Brabender Viscograph. Results showed that addition of gum Arabic significantly (p chapati. These findings support the need to utilize gum Arabic from Acacia senegal var. kerensis as a dough improver. 展开更多
关键词 Gum Arabic IMPROVER RHEOLOGY HYDROCOLLOIDS Wheat Dough
下载PDF
Poly-Acrylic Acid Derivatives as Diesel Flow Improver for Paraffin-Based Daqing Diesel 被引量:9
2
作者 Cuiyu Jiang Ming Xu +2 位作者 Xiaoli Xi Panlun Qi Hongyan Shang 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2006年第3期217-222,共6页
Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant (PPDs) that resulted from the high content of paraffin, certain poly-acrylic a... Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant (PPDs) that resulted from the high content of paraffin, certain poly-acrylic acid derivatives (PADE) with-COOR, -COOH,-CONHR, and -COO-NH3^+R groups by molecular design on the mechanics of diesel; PPDs were synthesized and evaluated as cold flow improver for Daqing 0^# diesel in this paper. The pure PADE was superior to the commercial PPDs and displayed a substantial ability of wax crystals dispersion. There was a synergistic effect among the PADE and T1804 and secondary amine. The synergism clearly improved the low temperature performance of Daqing diesel products and could reduce the cold filter plugging point of 0^# diesel by 6-7 ℃. 展开更多
关键词 DIESEL cold flow improver acrylic acid cold filter plugging point
下载PDF
A new alternating copolymerized derivative as a cold flow improver for diesel fuel 被引量:3
3
作者 ZHANG Haikuan LIU Hongyan WANG Shujun 《Petroleum Science》 SCIE CAS CSCD 2009年第1期82-85,共4页
Synthesis of a cold flow improver (MAVA-a) for diesel fuel and its effect on solidifying point (SP) and cold filter plugging point (CFPP) of diesel fuels were investigated, The cold flow improver was prepared by... Synthesis of a cold flow improver (MAVA-a) for diesel fuel and its effect on solidifying point (SP) and cold filter plugging point (CFPP) of diesel fuels were investigated, The cold flow improver was prepared by using maleic anhydride (MA) and vinyl acetate (VA) as raw materials, toluene as solvent, dibenzoyl peroxide (BPO) as initiator, through alternating polymerization under nitrogen to obtain a binary-polymer and then through aminolysis by using a higher carbon amine as aminating agent at a temperature of 80 ℃. A cold flow improver was designed and prepared for No. 0 diesel fuel from Zhang Jia-Gang Petrochemical Company according to the contents of n-paraffin and its carbon number distribution in the No. 0 diesel fuel. It was also used together with two kinds of ethene-vinyl acetate copolymer improvers (EVA) separately. The test result showed that the CFPP of the No. 0 diesel fuel could be lowered by 3-5 ℃ when the improver MAVA-a was used. The CFPP was lowered by 8℃ when the improver MAVA-a was used together with EVA-2. 展开更多
关键词 Cold flow improver solidifying point cold filter plugging point COPOLYMER AMINATION
下载PDF
Co-adsorption behaviors of asphaltenes and different flow improvers and their impacts on the interfacial viscoelasticity 被引量:2
4
作者 Hao Zhang Daiwei Liu +5 位作者 Jiangbo Wen Guangyu Sun Chuanxian Li Xinya Chen Huihui Zhang Ze Duan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第8期149-157,共9页
Commonly used flow improvers in oilfields,such as ethylene–vinyl acetate copolymer(EVA),poly(octadecyl acrylate)(POA),and polymethylsilsesquioxane(PMSQ)are proven to be effective to enhance the flowability of crude o... Commonly used flow improvers in oilfields,such as ethylene–vinyl acetate copolymer(EVA),poly(octadecyl acrylate)(POA),and polymethylsilsesquioxane(PMSQ)are proven to be effective to enhance the flowability of crude oil.However,the addition of these flow improvers may change the stability of the emulsion and make the crude oil treatment process challenging.In this research,the impacts of different flow improvers on the interfacial properties of the emulsions containing asphaltenes are systematically investigated.The co-adsorption behaviors of the flow improvers and asphaltenes are analyzed through dynamic interfacial tension(DIFT).The rheological properties of the interfacial layer after the adsorption are explored via dilational viscoelasticity.Significant difference is observed in the structural properties of the interface adsorbed by different flow improvers,which is attributed to different interactions between the flow improvers and asphaltenes.To investigate these interactions,conductivity,asphaltenes precipitation,dynamic light scattering(DLS),and contact angle experiments are conducted systematically.Results show that EVA and POA can alter the interfacial properties by changing the asphaltene dispersion state.The interaction between EVA and asphaltenes is stronger than that between POA and asphaltenes due to the difference in molecular structures.Unlike EVA and POA,the change of interfacial property with the addition of PMSQ is attributed to the partial adsorption of asphaltenes on PMSQ. 展开更多
关键词 ASPHALTENE Flow improver Interfacial tension Interfacial rheology Emulsions Adsorption
下载PDF
Chloroaluminate ionic liquid catalyzed isomerization of n-pentane in the presence of product distribution improver 被引量:1
5
作者 Xia Rong'an Zhang Rui Meng Xianghai Liu Zhichang Meng Jiaying Xu Chunming 《Petroleum Science》 SCIE CAS CSCD 2011年第2期219-223,共5页
The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an ... The ionic liquid Et3NHC1-2AIC13 can catalyze the isomerization of n-pentane. This paper investigates the ionic liquid catalyzed isomerization performance of n-pentane with several product distribution improvers in an autoclave. The product distribution of n-pentane isomerization could be improved by such improvers as benzene, cyelohexane, and methyl cyclohexane at the expense of conversion of n-pentane. The optimal product distribution improver was determined to be cyclohexane. The yield of isomerate and the selectivity of liquid isoalkanes increased, whereas the conversion of n-pentane decreased, with increasing cyclohexane amount. At the same conversion of n-pentane, the research octane number (RON) of liquid product, with cyclohexane amount of 0.5 wt%, was about 1.3 higher than that without cyclohexane. At the same reaction conditions, the presence of cyclohexane enhanced the yield of isomerate, the selectivity of liquid isoalkanes, and the RON of the liquid product, but reduced the conversion of n-pentane. 展开更多
关键词 ISOMERIZATION ionic liquid IMPROVER PENTANE cyclohexane
下载PDF
How Polymers Behave as Viscosity Index Improvers in Lubricating Oils 被引量:4
6
作者 Michael J. Covitch Kieran J. Trickett 《Advances in Chemical Engineering and Science》 2015年第2期134-151,共18页
One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearin... One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearing characteristics. Viscosity Index (VI) is one approach used widely in the lubricating field to assess the variation of viscosity with temperature. The VI of both mineral and synthetic base oils can be improved by the addition of polymeric viscosity modifiers (VMs). VI improvement by VMs is widely attributed to the polymer coil size expanding with increasing temperature. However, there is very little physical data supporting this generally accepted mechanism. To address this issue, intrinsic viscosity measurements and Small-Angle Neutron Scattering (SANS) have been used to study the variation of polymer coil size with changing temperature and concentration in a selection of solvents. The results will show that coil size expansion with temperature is not necessary to achieve significant elevation of viscosity index. 展开更多
关键词 VISCOSITY Index IMPROVER VISCOSITY MODIFIER Polymer SMALL-ANGLE NEUTRON Scattering RHEOLOGY
下载PDF
Aminated Copolymers as Flow Improvers for Super-viscous Crude Oils 被引量:1
7
作者 Zhang Hong Shen Benxian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2007年第3期43-49,共7页
The new flow improvers for super-viscous crude oils were developed via esterification of polybasic high carbon alcohol with methacrylate and copolymerizafion of monomers followed by amination of copolymers. The struct... The new flow improvers for super-viscous crude oils were developed via esterification of polybasic high carbon alcohol with methacrylate and copolymerizafion of monomers followed by amination of copolymers. The structure of the synthesized polymer flow improver additive was confirmed by IR spectroscopy and the crystal structure of the flow improver additives were determined by X-ray diffrac- tion analysis. The structure of wax crystals was also studied at the same time. The results showed that the wax crystal structure was closely related with the crystal structure of the flow improver, which could change the pour point depression and viscosity reduction behavior of the crude oil. When the wax crystal structure matched well with that of the additive, the wax crystals were dispersed satisfactorily, resulting in favorable effects in terms of pour point depression and viscosity reduction. The new synthe- sized aminated polymer flow improver additive was most efficient for treating super-viscous crude oils. The super-viscous crude oil had a high content of resins and asphaltenes, which might aggregate onto the surface of wax crystals to form blocks to limit the crude oil fluidity. However, amination of copolymers having similar structure with the resins and asphaltenes contained in crude oil could dissolve the huge polar groups to make the deposit formation difficult. 展开更多
关键词 aminated copolymers flow improver super-viscous crude oil
下载PDF
Synthesis and Properties of Dendritic Long-Chain Esters as Crude Oil Flow Improver Additives 被引量:1
8
作者 Li Cuiqin Sun Peng +1 位作者 Shi Weiguang Wang Jun 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2016年第1期83-91,共9页
The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amid... The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl longchain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efficiencies of dendritic long-chain esters were not only influenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efficiencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efficiencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil. 展开更多
关键词 dendrimer flow improver dendritic long-chain ester pour point depressant
下载PDF
Ecological functions of biochar
9
作者 TAN Wen-feng LIN Qi-mei 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第7期1473-1473,共1页
Biochar has been widely applied as a soil amendment in many parts of the world,which can enhance soil organic carbon (SOC) sequestration and nutrient availability beyond the fertilizer effect.Enriched in poly-condense... Biochar has been widely applied as a soil amendment in many parts of the world,which can enhance soil organic carbon (SOC) sequestration and nutrient availability beyond the fertilizer effect.Enriched in poly-condensed aromatic C forms,biochar-C is difficult to be degraded and can hold carbon in soils for hundreds to thousands of years. 展开更多
关键词 NUTRIENT AVAILABILITY Biocharcoal SOIL IMPROVER
下载PDF
Effect of equalising ignition delay on combustion and soot emission characteristics of model fuel blends
10
作者 Hamisu Adamu Dandajeh Nicos Ladommatos Paul Hellier 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第1期89-101,共13页
This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank ... This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank angle degree(CAD)before top dead center(BTDC)and a set of constant ignition timing tests while also keeping the 10℃AD BTDC injection and adding ignition improver(2-ethylhexylnitrate-,2-EHN)to the fuel mixtures.Soot particles were characterized using DMS-500 instrument in terms of mass,size,and number.The experimental results showed that adding 2-EHN to the model fuel blends reduced the soot surface area,soot mass concentration and soot mean size.Replacing 20 vol%of a C 7-heptane with 20 vol%methyl-decanoate(an oxygenated C 11 molecule)did not affect the ignition delay or rate of fuel air premixing,the peak in-cylinder pressure or heat release rates.Toluene addition(0−22.5 vol%)to heptane increased the mean size of the soot particles generated by only 3%while also resulted in a slight increase in the peak cylinder pressure and peak heat release rates.Blending toluene and methyl-decanoate into heptane without adding 2-EHN increased the premix phase fraction by at least 13%.However,by adding 2-EHN(4×10^(−4)−1.5×10^(−3)),the premixed phase fraction decreased by at least 11%. 展开更多
关键词 combustion characteristics soot emission compression ignition engine ignition improver premixed phase
下载PDF
Study on Dibehenyl Fumarate-Vinyl Acetate Copolymer for Lowering Cold Filter Plugging Point of Diesel Fuel
11
作者 Du Tao Wang Shujun +1 位作者 Liu Hongyan Zhang Ying 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2010年第4期52-56,共5页
In the practice of petroleum industry, adding cold flow improver (CFI) to lower the fuel's cold filter plugging point (CFPP) is an effective and economic way for improving the cold flow performance of diesel fuel... In the practice of petroleum industry, adding cold flow improver (CFI) to lower the fuel's cold filter plugging point (CFPP) is an effective and economic way for improving the cold flow performance of diesel fuel. This paper described the synthesis and evaluation of the performance of dibehenyl fumarate-vinyl acetate (FV) copolymer for improving the cold flow performance of the tested diesel fuels. The carbon distribution in n-alkanes of the tested diesel samples were analyzed by gas phase chromatography. The structure of the copolymer was confirmed by the 1H NMR spectroscopy. The wax crystals morphologies with and without adding the FV additive were investigated by means of polarizing microscope. The test results indicated that the FV additive could depress CFPP of the tested diesel samples by 2℃ and 4℃, respectively, when dosage of the additive was 0.08 m%. The additive can modify the size and shape of the wax crystals and inhibit the formation of larger wax crystal lattices. 展开更多
关键词 diesel fuel cold flow improver cold filter plugging point COPOLYMER wax crystal
下载PDF
Effects of Soil Improver on Wheat in Saline-Alkali Lands in the Yellow River Delta
12
作者 Liang DONG Shenzhong TIAN +6 位作者 Zeqiang SUN Xuejun WANG Zhaohui LIU Ruiqin LI Ye TIAN Deshui TAN Jiafa LUO 《Agricultural Biotechnology》 CAS 2019年第2期133-136,共4页
Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil ... Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil bulk density, soil pH and soil salt content, increase soil organic matter and 1 000-grain weight, thereby enhancing wheat yield. With the increase of soil improver application amount, soil physical-chemical properties became better and wheat yield increased. However, there was no significant difference in the treatments with the application amounts of 3%, 4% and 5%. In addition, the treatment of reducing nitrogen showed no superiority in soil physical-chemical properties and wheat yield, indicating that sufficient nitrogen was essential for the growth of wheat. 展开更多
关键词 SOIL improver SALINE-ALKALI LAND WHEAT
下载PDF
Mechanism of La2O3 as combustion improver in blast furnace coal injection
13
作者 Yanqin Sun Bing Hu +1 位作者 Qing Lü Shuhui Zhang 《International Journal of Coal Science & Technology》 EI 2016年第1期47-52,共6页
La2O3 is a combustion improver suitable for burning pulverized coal in blast furnace. La2O3 forms the active species La3+(CO-)3 that weakens the bridge adhesion of carbon structural units and alters the lattice str... La2O3 is a combustion improver suitable for burning pulverized coal in blast furnace. La2O3 forms the active species La3+(CO-)3 that weakens the bridge adhesion of carbon structural units and alters the lattice structures, thus reducing the activation energy of the pulverized coal and accelerating the burning process. Research shows that La2O3 can form the active species La3+(CO-)3, which weakens the bridge adhesion of carbon structural units and alters the lattice structures of the fixed carbon, hence decreasing the activation energy of the pulverized coal and accelerating the burning process. 展开更多
关键词 Combustion improver La2O3 - Microcrystalline parameter - Average particle diameter Morphologicalappearance
下载PDF
Effects of Cereal Malts Used as Improver on Physico-Chemical, Nutritional and Sensory Characteristics of Wheat and Millet Composites Breads
14
作者 Fidèle Wend-Bénédo Tapsoba Diarra Compaore-Sereme +4 位作者 Clarisse Sidbéwendé Compaore Thomas Jean Ndig-Yenouba Wendkuni Anne Christelle Yaogho Ndegwa Henri Maina Hagrétou Sawadogo-Lingani 《Food and Nutrition Sciences》 CAS 2022年第7期669-689,共21页
The aim of this study was to optimize composite breads of wheat and whole millet flour by the use of natural improvers. Three types of local malted cereals were used as natural improvers. The millet flour was fermente... The aim of this study was to optimize composite breads of wheat and whole millet flour by the use of natural improvers. Three types of local malted cereals were used as natural improvers. The millet flour was fermented with EPSs producing LAB strain prior to use. The technological characteristics of the composite flours were determined using an alveograph. The physico-chemical and nutritional characteristics of the composite breads were determined using standard methods and their sensory profiles were evaluated by a panel of 35 consumers. The alveograph results showed an increase in dough resistance, deformation and a decrease in extensibility and elasticity with the level of incorporation of millet flour. From the results of physico-chemical analyses of composite breads, no significant difference (p > 0.05) was observed in the use of the three types of local cereal malts except for the incorporation of 50% of the millet flour. The control sample presented the lowest acidity and dry matter value, the highest water content and pH value. No significant difference (p > 0.05) was observed in the use of the three types of cereal malts for the macronutrient contents of the composite bread samples. However, differences were observed according to the levels of incorporation. Macronutrients results showed an increase in protein content (11.17% ± 0.28% - 14.01% ± 0.10%/DM);crude fat content (1.86% ± 0.05% - 2.48% ± 0.20%/DM) and a decrease in carbohydrates content (85.36% ± 0.54% - 81.06% ± 0.36%/ DM). Regarding the content of mineral elements, significant differences (p < 0.05) were observed in the use of the three types of cereal malts for the incorporation of 15% (Mg and Fe content), 30% (Fe, Zn and K) and 50% (content of Zn, K, Na and Mg) of millet flour. The free amino acid profile revealed three essential amino acids such as valine, isoleucine and lysine. Breads incorporated with 30% of whole millet flour were the most appreciated by consumers. 展开更多
关键词 Composite Bread Cereal Malts IMPROVER MILLET Sensorial Characteristics
下载PDF
New PAMA Technology Helps Tackle the New Challenges of China Automotive Sector
15
作者 Alex Tsay 《润滑油》 CAS 2010年第1期31-38,共8页
Polyalkylmethacrylate (PAMA) based viscosity index improver (VII) and pour point depressant (PPD), with the versatile chemistry and unique performance characteristics, are widely used in advanced formulations, enablin... Polyalkylmethacrylate (PAMA) based viscosity index improver (VII) and pour point depressant (PPD), with the versatile chemistry and unique performance characteristics, are widely used in advanced formulations, enabling fluids to meet rheological requirement of modern specifications. This paper will be dedicated to the application of PAMA in helping China automotive lubricant formulators tackle the challenges of improving fuel economics from using lower viscosity fluids, of better protection strengthten in transmission performance and meeting new global specifications for low temperature performance. 展开更多
关键词 polyalkylmethacrylate viscosity index improver pour point depressant automatic transmission fluid gear oil ROBO test
下载PDF
KMnO_4助燃高炉喷吹煤粉的机制 被引量:2
16
作者 冯帅 吕庆 +3 位作者 孙艳芹 吴玮楠 王瑞哲 毕耜友 《钢铁研究学报》 CAS CSCD 北大核心 2013年第9期11-15,共5页
KMnO4是一种适合高炉生产的煤粉助燃剂,通过热重-差热分析其助燃机制是Mn7+(CO-)7削弱了碳结构单元间的桥键结合力以及改变了晶格结构,使煤粉活化能降低,加速燃烧。通过模拟高炉风口的燃烧条件并收集未燃煤粉,采用XRD和SEM方法检测,可... KMnO4是一种适合高炉生产的煤粉助燃剂,通过热重-差热分析其助燃机制是Mn7+(CO-)7削弱了碳结构单元间的桥键结合力以及改变了晶格结构,使煤粉活化能降低,加速燃烧。通过模拟高炉风口的燃烧条件并收集未燃煤粉,采用XRD和SEM方法检测,可知随着助燃剂KMnO4的加入,未燃煤粉的微晶参数增大,芳香片层的堆砌高度升高0.001 3nm,层片直径增大0.036 6nm;KMnO4使未燃煤粉颗粒的平均粒径减小2.62μm。 展开更多
关键词 助燃剂KMnO4 未燃煤粉 微晶参数 平均粒径 COMBUSTION IMPROVER adding KMNO4
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部