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1.
Identifying new uses for residues of industries that process large quantities of biomass, as in bioethanol production, is essential for a sustainable development with reduced impact on the environment, which is the reason why many efforts have been devoted to find noble uses for lignins. In this study, a lignin obtained from sugarcane bagasse in a bioethanol producing plant was carboxymethylated to yield the water-soluble carboxymethyl lignin (CML), which was then used as stabilizing agent in aqueous alumina (Al2O3) suspensions. CML had a degree of substitution 0.46 ± 0.01, in relation to the C9 unit of lignin, and behaved as a polyelectrolyte in a large pH range owing to the dissociation of carboxylic groups. The action of CML as stabilizing agent of alumina aqueous suspensions was investigated using viscometry, zeta potential, and photon correlation spectroscopy (PCS) measurements, mainly as a function of pH and time. Overall, the results showed that CML had a good performance as a deflocculating agent, because it led to dispersions with low viscosity and small change in particle size as a function of time. The positive effect from the addition of CML was confirmed in the morphological features of the material obtained from the alumina suspensions after elimination of water, as indicated by scanning electron microscopy. The stabilization of alumina suspensions afforded by CML opens the way for similar applications of modified lignins, whose electrical and structural properties may be tuned for specific uses in various industries, including the ceramic industry.  相似文献   

2.
Fortified date bars were prepared from some of the commonly grown date cultivars in the United Arab Emirates. The average ash, fat and protein contents in the control date bar sample were 1.78, 6.09 and 7.83%, respectively. The ash and protein contents increased, but the fat content decreased slightly with the inclusion of skim milk powder in the remaining date bar formulations. All the date bar samples were found to be free from Enterobacteriaceae and coliforms. Date fruit, which usually supplies only calories, can thus be turned into a product having significant amounts of other valuable nutrients.  相似文献   

3.
In the flow of turbulent fiber suspensions flowing through a contraction with rectangular cross-section, the Reynolds averaged Navier-Stokes equation with the term of additional stress resulting from fibers was solved with the Reynolds stress model to get distributions of the mean velocity, mean pressure, turbulent kinetic energy and turbulent dissipation. It is found that the mean velocities at exit are small around the center and large near the wall for higher concentration. Fibers reduce turbulent intensity and turbulent dissipation at central line, but enhance them over the cross section at exit. Fibers have no effect of restraint on the turbulence in the contraction flow. The additional stress resulting from fibers plays a role in the increase of drag.  相似文献   

4.
目的观察人参超微粉对大鼠实验性低血压模型的升压作用。方法 40只Wistar大鼠随机选取10只作为正常组,其余30只灌胃(ig)复方利血平混悬液(10m L/kg每日2次)制备低血压模型,连续7周,将收缩压≤80mm Hg的大鼠选入实验。24只造模成功大鼠结合血压、体重随机分为3组:模型组、人参超微粉0.5、1.0g/kg组,每组8只。模型组大鼠ig 0.5%羧甲基纤维素钠10m L/kg,人参超微粉组分别ig相应药物,每日1次,连续4周。采用尾套法于造模前、造模过程中及给药后每周测量大鼠血压1次,观察人参超微粉对大鼠实验性低血压的升压作用。结果与正常组比较,模型组大鼠于造模第5~7周可见SBP、DBP及MAP均明显下降(P0.01或P0.001)。与模型组比较,人参超微粉0.5g/kg于给药第3~4周可见SBP、DBP及MAP均明显升高,人参超微粉1.0g/kg于给药第2~4周可见SBP、DBP及MAP均明显升高(P0.05或P0.01)。结论人参超微粉对大鼠实验性低血压模型具有升压作用。  相似文献   

5.
采用邻二氮菲分光光度法对豆奶粉中铁的测定进行了研究,并对其影响因素进行了分析和探讨.通过单因素实验确定其最佳测量条件为:最大吸收波长510 nm、有色配合物的反应时间 10 min、邻二氮菲溶液添加量2.00 mL、1.0 mol/L NaOH溶液1.50 mL.通过原子吸收分光光度法验证,该方法简单方便、精确度高,可广泛用于豆奶粉中铁的测定.  相似文献   

6.
A theoretical model is proposed in order to investigate rheological behavior of bubble suspension with large deformation. Theoretical constitutive equations for dilute bubble suspensions are derived by applying a deformation theory of ellipsoidal droplet [1] to a phenomenological suspension theory [2]. The rate of deformation tensor within the bubble and the time evolution of interface tensor are predicted by applying the proposed constitutive equations, which have two free fitting parameters. The transient and steady rheological properties of dilute bubble suspensions are studied for several capillary numbers (Ca) under simple shear flow and uniaxial elongational flow fields. The retraction force of the bubble caused by the interfacial tension increases as bubbles undergo deformation. The transient and steady relative viscosity decreases asCa increases. The normal stress difference (NSD) under the simple shear has the largest value whenCa is around 1 and the ratio of the first NSD to the second NSD has the value of 3/4 for largeCa but 2 for smallCa. In the uniaxial elongational flow, the elongational viscosity is three times as large as the shear viscosity like the Newtonian fluid.  相似文献   

7.
婴儿配方奶粉生产中部分应用大豆分离蛋白的研究   总被引:1,自引:0,他引:1  
通过对人乳和牛乳蛋白质组分的差异比较,利用大豆分离蛋白中的优质氨基酸与乳蛋白混合后的营养互补,提高营养价值.同时与乳糖配合可以达到部分替代脱盐乳清粉D90的目的,进而提升产品营养,做到婴儿配方奶粉的国产化.  相似文献   

8.
The equation of Reynolds averaged Navier-Stokes with the term of additional stress resulted from fibers and the equation of probability distribution function for mean fiber orientation are derived and solved numerically to explore the characteristics of fiber suspension flow in a channel. The mathematical model and numerical code are validated by comparing the computational results with the corresponding experimental ones. The effect of Reynolds number, fiber concentration and fiber aspect-ratio on the velocity profile, turbulent intensity, and turbulent dissipation rate is analyzed. The results show that the effect of fibers on turbulent channel flow is equivalent to an additional viscosity, but at this range of fiber concentration, the effect of the presence of fibers was small. The turbulent velocity profiles of fiber suspension become gradually sharper in the central region of channel by increasing the fiber concentration and/or decreasing the Reynolds number. The velocity gradient near the wall decreases gradually as the fiber aspect-ratio increased. The turbulent kinetic energy will increase with increasing Reynolds number, fiber concentration, and fiber aspect-ratio. The turbulent dissipation rate will increase with increasing fiber concentration or decreasing fiber aspect-ratio. Finally, the equation of velocity profile for turbulent fiber suspension channel flow, involving the effect of Reynolds number, fiber concentration, and aspect-ratio, is derived.  相似文献   

9.
大豆分离蛋白在婴幼儿配方乳粉中的应用   总被引:2,自引:0,他引:2  
利用大豆分离蛋白为优质的蛋白质,将其应用到婴幼儿配方乳粉中,并研究了添加比例及杀菌温度等因素对产品不溶度指数的影响,摸索出大豆分离蛋白在婴幼儿配方乳粉中的最佳添加比例,提高婴幼儿配方乳粉的优质蛋白质的含量。  相似文献   

10.
Composites of Natural rubber (NR) Peanut shell powder (PSP) were prepared and their morphology, transport behavior at different temperatures in chlorinated solvent were studied. The PSP used in compounding the natural rubber was processed in two particle sizes. The effect of modification by alkali treatment of PSP on polymer properties was also investigated. The computed solvent properties were discussed in terms of PSP content, particle size, nature of solvent, and temperature. All the NR-PSP composites were found to decrease with the uptake of chlorinated solvents than NR, but the effect was more significant in the case of alkali treated PSP composites. Furthermore, the uptake of solvent decreased with increase in penetrant size; being the highest for dichloromethane, and the lowest for carbon tetrachloride. Activation energy was found to be maximum for highest in dichloromethane at the filler contents investigated. The thermodynamic parameters of the sorption process were also evaluated. The results showed that PSP filler acts as functional additives capable of manipulating and tailoring the transport of chlorinated solvents through elastomeric membranes even at concentrations as low as 10 parts per hundred (phr). The relationship between the transport behaviour and the morphology of the system was also examined.  相似文献   

11.
12.
In the work described, seed oils rich in linolenic acid were used for the synthesis of aliphatic oxiranes. The oils studied were linseed (Linum usitatissimum) oil, Canadian linseed oil and the oil of Lallemantia iberica. The oils contained 54.1, 60.2 and 68.0% of linolenic acid, respectively, and showed high theoretical iodine values of 211, 226 and 236 g/hg. Unsaturations in the oils were used to introduce epoxides by epoxidation with in situ generated peroxyacetic acid. The epoxidized oils, showing high percentages of oxirane oxygen (9.4, 10.0 and 10.7%), were applied as crosslinkers in powder-coating formulations. The major advantage of these types of crosslinkers is that they are neither toxic nor mutagenic, in contrast with the widely applied synthetic triglycidyl isocyanurate (TGIC) crosslinkers. However, two potential problems exist when aliphatic oxiranes are compared with conventional TGIC systems. A decrease in glass transition temperature (Tg) of the powder formulation and a higher degree of yellowing of the coating are often observed. In this paper the effects of using oils containing high linolenic acid contents on the yellowing of the coating and the Tg of the powder, are studied. It appeared that aliphatic oxiranes are suitable as environment-friendly crosslinkers in powder-coating systems.  相似文献   

13.
Tulasi leaf powder was fed at the 1% level in normal and diabetic rats for a period of one month to explore the effect on fasting blood sugar, uronic acid, total amino acids, and the lipid profile in serum and tissue lipids. The results indicated a significant reduction in fasting blood sugar, uronic acid, total amino acids, total cholesterol, triglyceride, phospholipids and total lipids. In liver, total cholesterol, triglyceride and total lipids were significantly lowered. Total lipids were significantly reduced in kidney. In heart, a significant fall in total cholesterol and phospholipids was observed. All these observations indicate the hypoglycemic and hypolipidemic effect of Tulasi in diabetic rats.  相似文献   

14.
The effect of dry Sundakai powder supplementation (7 g providing 1.23 g of crude fibre) on glycemic control, lipidemic control, total amino acids and uronic acid was studied on 30 non-insulin dependent diabetes mellitus patients. All the patients were on hypoglycemic drugs. The above parameters were monitored at day 1, 15 and 30 days. After one month of fibre supplementation, no significant changes were observed with respect to glucose, lipid profile, glycated proteins, total amino acids and uronic acid levels in these subjects.  相似文献   

15.
详细说明了在大豆粉状制品自动化生产线中所使用的数据处理方法和控制方法,通过将数据处理和系统控制交付给计算机处理,有效避免了人为控制的主观性和不准确性。所研制大豆粉状制品自动化生产线在实际生产中显著提高了产品质量和生产效率。  相似文献   

16.
在培养日本曲霉(Aspergillus japonicus-FCL)和黑曲霉(Aspergillus niger ATCC 20611)的过程中,研究了培养基中不同浓度的蔗糖(3~25%w/v)和蛋白胨(2~5%w/v)对曲霉的影响以探索较优配方。此外,甘蔗糖蜜(3.5~17.5%w/v总糖量)和酵母粉(1.5~5%w/v)被当作两种菌株的营养素替代品用于研究。探索这些培养基的目的是用来分析细胞生长趋、果糖基转移酶产酶和低聚果糖(FOS)产物。果糖基转移酶活性和低聚果糖产量利用高效液相色谱进行检测分析。两种菌株在3%(w/v)蔗糖和3%(w/v)蛋白胨的培养基中酶反应产物含量最高,或者在含总糖3.5%(w/v)的甘蔗糖蜜和1.5%(w/v)酵母粉的培养基中可以达到同等效果。研究表明,甘蔗糖蜜和酵母粉在酶和低聚果糖(约60%w/w)的生产中与蔗糖和蛋白胨的效果一样好。  相似文献   

17.
对60 %环·敌可湿性粉剂进行了田间小区药效试验 ,结果表明该药剂防除蔗地杂草效果优良。每667m2 施药100 -225克防效达90 %以上。在杂草充分萌芽后5叶期左右施药能有效防除一年生单、双子叶杂草 ,对甘蔗相对安全。但不同甘蔗品种对其敏感性有差异。推荐使用剂量为每667m2 施100-160克  相似文献   

18.
Powders prepared from sweetflag Acorus calamus rhizomes collected at both high (1700 m) and low (900 m) altitude in Eastern Nepal were admixed with wheat at concentrations in the range 0.05–2% w/w and the wheat infested with Sitophilus oryzae or S. granarius adults. Following a 7 day incubation, the mortality of both species was significantly lower at 20 °C than at 30 °C, and the material collected from high altitude was slightly less toxic than that from low altitude. The moisture content of the wheat (14 or 17%) and the part of the rhizome used to prepare the powder (young or mature growth) had no apparent effect on the toxicity of the preparation. Sitophilus granarius (L.) adults were more tolerant of the material than S. oryzae (L.), while the converse was true for larvae developing in treated grain. An admixture rate of approximately 2% w/w admixed rhizome powder was required to give complete kill of adults of both species following 7 days exposure at 20 °C, while a concentration of 1% w/w either prevented the emergence of adults or killed them rapidly following emergence when wheat containing eggs of either species was incubated for 7–8 weeks at 30 °C.

The β-asarone content of the rhizome powders was determined by GC-MS as 6.4 and 4.7% w/w (mature section of rhizomes collected at high and low altitudes, respectively) and 3.6 and 4.0% w/w (young sections of rhizomes collected at high and low altitudes, respectively). It is anticipated that, under field conditions and in the temperature range 20–30 °C, the initial residue of approximately 1300 mg/kg β-asarone required to disinfest wheat containing these weevil species would decline rapidly due to evaporation.  相似文献   


19.
Abstract Because of the morphological and morphometric variation of testicular follicles in different genera of the subfamily Triatominae, it was of interest to associate those parameters with the different medial pronotal band patterns (wide and narrow) found in Rhodnius brethesi (Matta) (Hemiptera: Reduviidae). This is a wild species often associated with Leopoldina piassaba Wallace (Arecales: Arecaceae) palm, with a geographical distribution restricted to the Amazon region. The specimens used were from the state of Amazonas, and were kept under conditions of 29 ± 1 (°)C, 80 ± 5% RH, 12:12 L:D photoperiod, and were fed weekly on blood from Swiss mice. Three-day-old fasting males were separated in accordance with the patterns of the medial pronotal band, dissected, and the testicles removed. After removal of the testicular membrane, the follicles were spread, drawn by camera lucida, and measured. The results showed that the testis of R. brethesi consists of seven follicles, divided into two groups by length; two long and five short. In specimens with a wide medial pronotal band, the long follicles were 5.4 mm in length, but in specimens with a narrow medial band, the long follicles were 5.64 mm in length. The difference was significant. The short follicles were not different in length, suggesting the presence of a possible complex "brethesi" in the Amazon region.  相似文献   

20.
Endogenous gibberellins were measured in extracts of ‘Red Pontiac’ potato tubers sampled during tuber ontogeny. Stolons contained high levels of activity and developing tubers low activity, as indicated by elongation in the dwarf pea and maize mutant bioassays. However, dilution of the extracts of young tubers revealed that low gibberellin-like activity may have been due to the presence of an inhibitor. Based on co-chromatography this inhibitor was found not to be abscisic acid nor did abscisic acid induce tuber formation after treatment of the intact plant, treatment of the developing stolons or after addition to potato stolons grown in tissue culture medium.  相似文献   

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