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101.
M. A. Ali M. A. Gafur M. S. Rahman G. M. Ahmed 《Journal of the American Oil Chemists' Society》1985,62(3):520-523
The kernels of 10 different mango varieties were extracted. The physico-chemical characteristics and lipid class composition
of fats were studied. The fat content of mango kernels grown under the soil and climatic conditions of Bangladesh varied from
7.1% to 10%, depending on the variety. The total lipid extracts were fractionated into lipid classes by a combination of column
and thin layer chromatography (TLC). The hydrocarbon and sterol esters varied from 0.3% to 0.7%, triglycerides from 55.6%
to 91.5%, partial glycerides from 2.3% to 4% and free sterol from 0.3% to 0.6%. Free fatty acids amounted to 3.0–37% as oleic;
glycolipids were 0.6–1.2% and phospholipids 0.11–0.8%. The fatty acid composition of triglyceride (TG) fractions was analyzed
by gas liquid chromatography (GLC). Palmitic acid varied from 7.9 molar % to 10.0 molar %, stearic from 38.2% to 40.2%, oleic
from 41.1% to 43.8%, linoleic from 6.0% to 7.6%, linolenic from 0.6% to 1.0% and arachidic acid from 1.7% to 2.6%. TLC revealed
the presence of lyso-phosphatidylcholine, phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine and phosphatidic
acid in the phospholipid fraction. 相似文献
102.
A Flavanone and Two Phenolic Acids from Chrysanthemum morifolium with Phytotoxic and Insect Growth Regulating Activity 总被引:2,自引:0,他引:2
Beninger CW Abou-Zaid MM Kistner AL Hallett RH Iqbal MJ Grodzinski B Hall JC 《Journal of chemical ecology》2004,30(3):589-606
Leaves of Chrysanthemum morifolium cv. Ramat were extracted sequentially with hexane, ethyl acetate, and methanol. The methanol fraction, when incorporated into artificial diet was found to reduce the growth of cabbage looper (Trichoplusia ni Hubner) larvae at concentrations between 500 and 5000 ppm of diet. Fractionation of the methanol extract on a Sephadex column yielded five fractions, three of which reduced the weight of larvae relative to the control. One fraction was analyzed using high performance liquid chromatography (HPLC) and found to contain three main constituents. These compounds were purified using a combination of gel permeation chromatography on Sephadex LH20 and HPLC, and analyzed by 1H and 13CNMR as well as undergoing chemical and physical analyses. The compounds were identified as: 1, chlorogenic acid (5-O-caffeoylquinic acid); 2, 3,5-O-dicaffeoylquinic acid; and 3, 3', 4',5-trihydroxyflavanone7-O-glucuronide (eriodictyol7-O-glucuronide). At concentrations between 100 to 1000 ppm these compounds reduced both growth and photosynthesis of Lemna gibba L. with the order of efficacy being: flavanone > chlorogenic acid > 3,5-O-dicaffeoylquinic acid. Furthermore, when incorporated separately into artificial diet these compounds, at 10 to 1000 ppm, enhanced or reduced growth of the cabbage looper (Trichoplusia ni) and gypsy moth (Lymantria dispar L.). 相似文献
103.
104.
Load balancing is a crucial factor in IPTV delivery networks. Load balancing aims at utilizing the resources efficiently, maximizing the throughput, and minimizing the request rejection rate. The peer-service area is the recent architecture for IPTV delivery networks that overcomes the flaws of the previous architectures. However, it still suffers from the load imbalance problem. This paper investigates the load imbalance problem, and tries to augment the peer-service area architecture to overcome this problem. To achieve the load balancing over the proposed architecture, we suggest a new load-balancing algorithm that considers both the expected and the current load of both contents and servers. The proposed load-balancing algorithm consists of two stages. The first stage is the contents replication according to their expected load, while the second stage is the content-aware request distribution. To test the effectiveness of the proposed algorithm, we have compared it with both the traditional Round Robin algorithm and Cho algorithm. The experimental results depict that the proposed algorithm outperforms the two other algorithms in terms of load balance, throughput, and request rejection rate. 相似文献
105.
The electrochemical intercalation of H2SO4 into graphite leads to the well known graphite salts C+n HSO−4. χH2SO4 (with n → 20), χ ≈ 2.5). The potential—charge relations observed during intercalation agree well with a model involving the extended graphene layer-intercalate interfacial capacitance. The components of this capacitance are studied, including the effect of Fermi level lowering. A computed electrocapillary curve is compared to the separation work of graphene layers. 相似文献
106.
Yasmin AlNoamany Ahmed AlSum Michele C. Weigle Michael L. Nelson 《International Journal on Digital Libraries》2014,14(3-4):101-115
The Internet Archive’s (IA) Wayback Machine is the largest and oldest public Web archive and has become a significant repository of our recent history and cultural heritage. Despite its importance, there has been little research about how it is discovered and used. Based on Web access logs, we analyze what users are looking for, why they come to IA, where they come from, and how pages link to IA. We find that users request English pages the most, followed by the European languages. Most human users come to Web archives because they do not find the requested pages on the live Web. About 65 % of the requested archived pages no longer exist on the live Web. We find that more than 82 % of human sessions connect to the Wayback Machine via referrals from other Web sites, while only 15 % of robots have referrers. Most of the links (86 %) from Websites are to individual archived pages at specific points in time, and of those 83 % no longer exist on the live Web. Finally, we find that users who come from search engines browse more pages than users who come from external Web sites. 相似文献
107.
Lluís-Pere de las Heras Sheraz Ahmed Marcus Liwicki Ernest Valveny Gemma Sánchez 《International Journal on Document Analysis and Recognition》2014,17(3):221-237
A generic method for floor plan analysis and interpretation is presented in this article. The method, which is mainly inspired by the way engineers draw and interpret floor plans, applies two recognition steps in a bottom-up manner. First, basic building blocks, i.e., walls, doors, and windows are detected using a statistical patch-based segmentation approach. Second, a graph is generated, and structural pattern recognition techniques are applied to further locate the main entities, i.e., rooms of the building. The proposed approach is able to analyze any type of floor plan regardless of the notation used. We have evaluated our method on different publicly available datasets of real architectural floor plans with different notations. The overall detection and recognition accuracy is about 95 %, which is significantly better than any other state-of-the-art method. Our approach is generic enough such that it could be easily adopted to the recognition and interpretation of any other printed machine-generated structured documents. 相似文献
108.
In recent years there have been many reported cases of corrosion failure in cement concrete pipelines. In the majority of cases, the failures have been attributed to rebar corrosion which is caused by the permeability of chloride from low resistivity soil and subsequent attack on a passive layer on an iron bar in the structure. As a possible alternative to cementitious materials, some organic coatings based on olefin, vinyl or epoxy-based polymers have been considered. However, due to a paucity of data on the behavior of these coatings in aqueous media— particularly product water—the possibility of their application in water transmission systems in the Kingdom has not been fully exploited. This paper deals with the studies carried out on the corrosion and mechanical behavior of fusion bonded epoxy (FBE) coating on steel in aqueous media which include product water, distilled water and saline water. The mechanical testings on coating include adhesion, bending and cathodic disbondment testings. The corrosion studies include immersion testing under static and dynamic conditions, autoclave tests and accelerated (salt-fog) tests. The analysis of results indicates chemical inertness of FBE coating in either of the aforementioned water used during testing, good adhesion and no damage to the coating during bending. Cathodic disbondment tests indicate that FBE coating sustains under cathodic protection (CP) conditions. In general, the results of mechanical and corrosion tests indicate that FBE is a promising material for internal coating on steel in water transmission systems. 相似文献
109.
Ahmed A. Elkhateeb 《Nexus Network Journal》2014,16(1):219-232
This work presents four mathematical remarks concluded from the mathematical analysis for the interrelationships between the dependent and independent variables that control the measures: perimeter, floor area, walls surface area and total surface area in the regular forms that have a given volume. Such forms include prismatic and pyramidal forms. The work consists of four parts, of which this first part presents the remarks of the isosceles triangular right prism. The first remark examines the effect of θ, the angle of the triangular base, on the total surface area. The second remark calculates the minimum total surface area in two cases, depending on whether angle θ is constant or variable. The third remark calculates the walls ratio and the critical walls ratio. The last remark studies the required conditions for the numerical equality in two cases, where the perimeter is equal to the area, and where the total surface area is equal to the volume. 相似文献
110.