CDN网络分发算法的研究

CDN(Content Delivery Network)网络技术为解决网络信息传递性能的日益恶化而提出的一种改善Internet性能的方案。本文对几种主要的分发算法WRR、URL Hashing和LARD的性能在仿真实验的基础上进行了比较研究,对上述算法在系统吞吐量、缓存命中率、平均请求延时以及节点未利用率等四个方面的性能进行比较,以加深对分发算法的理解。

Studies on the Flavonoids and Antioxidant Activities in Leaves of Black Currant

The fresh leaves and oven dried leaves from three varieties of black currant (Brodtrop,liangye,Risager)were analysed for the total contents of flavonoids by spectrophotometric methods in terms of rutin equivalent.In addition,antioxidant activities of different addition amounts of extracts of black currant (Brodtrop)leaves in lard were measured by the Oven-Storage Test,and compared with the synthetic antioxidants.The results showed the contents of the flavonoids were very rich in the leaves of three varieties from black currant.Among them the leaves of Brodtrop had the highest contents of flavonoids followed by liangye and Risager.The total contents of flavonoids in fresh leaves reach 231 70 mg/100 g,170 01 mg/100 g and 78 07 mg/100 g respectively.In the same circumstance the oven dried leaves were 397 82 mg/100 g,275 89 mg/100 g and 169 73 mg/100 g.The extracts of the leaves from Brodtrop exhibited strong antioxidant activities on lard,which increased with the addition amount of the flavonoid extracts.The antioxidant activities decreased in the order of 0 02% quercetin >0 02% BHT(butylated hydroxy toluene)>0 40% extracts>0 20% extracts>0 10% extracts>0 05% extracts>0 02% extracts>control.

Optimization and kinetic modeling of waste lard methanolysis in a continuous reciprocating plate reactor

Continuous biodiesel production from a waste pig-roasting lard,methanol and KOH was carried out in a reciprocating plate reactor(RPR)using a factorial design containing three process factors,namely methanol/lard molar ratio,catalyst loading,and normalized height of the reactor.The main goals were to optimize the influential process factors with respect to biodiesel purity using the response surface methodology and to model the kinetics of the transesterification reaction in order to describe the change of triacylglycerols(TAG)and fatty acid methyl esters(FAME)concentrations along the RPR height.The first-order rate law was proved for both the reaction and the mass transfer.The model of the changing reaction mechanism and mass transfer of TAG was also applicable.Both kinetic models agreed with the experimental concentrations of TAG and FAME determined along the RPR height.

Effects of Lard Enriched with n-3 Polyunsaturated Fatty Acids on Serum Lipid Composition in Rats

This study evaluated the lard enriched with n-3 polyunsaturated fatty acids(PUFAs)on serum lipid composition in rats.The experiment contained two parts:(A)20 crossed pigs(Landrace×Min,60±2 kg)were assigned randomly into two dietary groups:a control group and a group fed the diet added 10%linseed based on the control diet.This part lasted 56 days and the results showed that the levels of the total n-3 PUFA in lard were improved approximately 2-fold(p<0.05),when pigs were fed 10% flaxseed compared to a control diet of corn.The lard taken from pigs was melted and preserved for rat experiment;(B)45 Sprague-Dawley rats at day 36 were randomly fed one of three diets for 42 days:the diet without added fat,the diet contained 10% common lard from pigs fed a conventional corn ration and the diet contained 10% lard enriched with n-3 PUFA from pigs fed 10% flaxseed.Rats fed lard significantly increased(p<0.05)serum cholesterol levels compared with rats maintained on a diet without lard.However,rats fed the lard enriched with n-3 PUFA significantly decreased the level of low-density lipoprotein cholesterol in serum(p<0.05)and better hepatic antioxidant defense capacities,when compared with rats fed common lard(p<0.05).The results showed that pigs fed diet with n-3 PUFA produced lard enriched with n-3 PUFA and thus provided positive health benefits to the consumers.

Isolation and Characterization of Microorganisms for Degradation of Minimal Oils and Fats at Low Temperatures

The isolation of microorganisms for biodegradation of minimal fats and oils at low temperatures was reported. By using rapeseed oil as a sole carbon source, six strains were isolated from five kinds of oils/fats-contaminated wastewater, soil, and active sludge. Among them, two strains which show the highest oil removal ratios were identified as Pseudomonas pseudoalcaligenes and Pseudomonas mendocina, respectively. The experiments of orthogonal impact conditions show that the optimal oil degradation condition is at pH 8.0, 5 ℃ and 100 mg/L oil. Under this condition, the rapeseed oil degradation ratios of two strains after 24 hours amount to 92.6% and 92.0% respectively, whereas the removal ratios of lard decrease to 39.5% and 54.3%.

Principal Component Analysis （PCA） on Multivariate Data of Lard Analysis in Cooking Oil

Discrimination of fatty acids （FAs） of lard in used cooking oil is important in halal determination. The aim of this study was to find the information related to the changes FAs of lard when frying in cooking oil. Quantitative analysis of FAs composition extracted from a series of experiments which involving frying cooking oil spiked with lard at three different parameters; concentration of spiked lard, heating temperatures and period of frying. The samples were analyzed using Gas Chromatography （GC） and Principal Components Analysis （PCA） technique. Multivariate data from chromatograms of FAs were standardized and computed using Unscrambler X10 into covariance matrix and eigenvectors correspond to Principal Components （PCs）. Results have shown that the first and second PCs contribute to the FAs mapping which can be visualized by scores and loading plots to discriminate FAs of lard in used cooking oil

Infrared Spectroscopy-Based Chemometric Analysis for Lard Differentiation in Meat Samples

One of the most pressing concerns for the consumer market is the detection of adulteration in meat products due to their preciousness.The rapid and accurate identification mechanism for lard adulteration in meat products is highly necessary,for developing a mechanism trusted by consumers and that can be used to make a definitive diagnosis.Fourier Transform Infrared Spectroscopy(FTIR)is used in this work to identify lard adulteration in cow,lamb,and chicken samples.A simplified extraction method was implied to obtain the lipids from pure and adulterated meat.Adulterated samples were obtained by mixing lard with chicken,lamb,and beef with different concentrations(10%–50%v/v).Principal component analysis(PCA)and partial least square(PLS)were used to develop a calibration model at 800–3500 cm^(−1).Three-dimension PCA was successfully used by dividing the spectrum in three regions to classify lard meat adulteration in chicken,lamb,and beef samples.The corresponding FTIR peaks for the lard have been observed at 1159.6,1743.4,2853.1,and 2922.5 cm−1,which differentiate chicken,lamb,and beef samples.The wavenumbers offer the highest determination coefficient R2 value of 0.846 and lowest root mean square error of calibration(RMSEC)and root mean square error prediction(RMSEP)with an accuracy of 84.6%.Even the tiniest fat adulteration up to 10%can be reliably discovered using this methodology.

Napier Grass Rumen Degradability in Sacco in Goats (<i>Capra hircus aegagrus</i>) Supplemented with Different Sources and Amount of Dietary Fats

The study aimed to explore the potential of dietary fats supplementation on the overall goat performance. Three (3) mature rumen-cannulated goats weighting 27.33 ± 1.53 kg housed in individual elevated metabolism stalls with customized fecal and urine collection tools with treatments replicated three times over time following the Complete Randomized Design (CRD). Animals were randomly selected on different dietary treatment at different cycle. For each cycle, animals were provided with 30% concentrate on the morning based on feed requirements {3% of their body weight (BW) dry matter (DM) basis} of the animals. Ad libitum feeding of Napier grass will follow thereafter. Clean drinking water were made available all the times in the respective animal watering troughs. The rumen-cannulated goats were supplemented with different levels of two dietary fats (VCO and Lard) with dietary treatment combinations as follows, Control and VCO and Lard at 3% & 5%. Degradability of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were collected sequentially in every cycle of the study. There were seven (7) days lag period in every cycle for the animals to return to each natural state. On the 8th day of every cycle, animals were given different dietary treatment. Sequential insertion of nylon bag was done on the 15th to 16th day (7 days after treatment). The results showed that degradability of the dry matter (DM) was noticed degraded exponentially on the first twelve hours of incubation and slower down in the next few hours until 48 hours. Crude protein, acid and neutral detergent fiber showed breakdown of components was observed in the first 48 hours of incubation. No significant difference (P > 0.05) among treatment means was observed in all parameters gathered. This implies that mature female goat diet cannot be influenced by dietary fats from two different sources (VCO and Lard) at 3% to 5% supplementation. Based on the study conducted, dietary fats supplementation on goats such as VCO and lard given at the maximum level of 5% level did not influence the nutrient degradability of Napier grass in the rumen until it reaches at 48 hours of incubation. Supplementing ruminant diets with dietary fat in goats could increase the energy density of the animal’s diet without adverse effect on rumen degradability. This simple, easy, and basic technique could also be applied to other animal species in pursuit of finding ways to formulate indigenous feedstuff materials that have potential nutritive values. Given the limitations such as the climatic and environmental constraints, this particular study would somehow serve as benchmark in conducting related researches in optimizing the conditions with respect to animal nutrition and feedstuff utilization. Thus, this study was done to augment productivity and to provide new opportunities for achieving enhanced growth performance in a way that alleviates poverty, improves food security and nutrition and promotes sustainable use of natural resources.

Moderate quantity of lard mixed with sunflower oil attenuate lipid accumulation in mice

Lard,a fat rich in saturated fatty acids(SFAs),is regarded as a risk factor for metabolic diseases.In the present study,effect of different lard blended with sunflower oil diets on lipid accumulation in adipose tissue,liver,and serum by mouse model was researched.Body weight,body fat percentage,cross-sectional area of adipocytes,liver triglycerides(TGs),and oil red stained area in mice liver of lard blend sunflower oil(L-SFO)group were significantly lower than those of sunflower oil(SFO)group,whereas no significant differences were observed between mice of lard and L-SFO groups.Serum TG and free fatty acid levels were significantly lower in L-SFO group than in other two groups.Furthermore,data showed that sunflower oil decreased contents of hormonesensitive lipase and carnitine palmitoyl transferase 1(CPT-1)and increased fatty acid synthase activity in liver tissue.A mixture of lard and sunflower oil rather than only sunflower oil or lard might promote body fat loss and reduce lipid accumulation in adipose tissue,serum,and liver by promoting hydrolysis of TG,increasingβ-oxidation of fatty acids.These data suggested that mixing lard and vegetable oil(e.g.sunflower oil)for cooking,or alternate using lard and vegetable oil could be beneficial for reducing body fat.

Effect of mixing lard with soybean oil in cooking on hepatic antioxidative ability and renal metabolic activity

A simulate daily oriental dietary pattern(a blend of lard and soybean oil)was performed in this research to investigate influence on liver and kidney function.Sixty mice were randomly divided into 6 groups with diets of different fat added oils respectively for 12 weeks.Malondialdehyde and uric acid contents in mice fed with blended oil were significantly lower than in those fed only with soybean oil and lard due to the improved activities of antioxidant enzymes.Daily use of a blend of lard with soybean oil significantly increased antioxidant capacity,reduced lipid peroxidation of liver and serum uric acid production,thus protected liver and renal function.It also suggests that the oriental dietary pattern might reduce the risk of gout.

Physicochemical properties of lard oil and rubber seed oil blends and their comprehensive characterization

This research investigates the potential of blending complementary lard oil with rubber seed oil as feedstock for biodiesel production.Rubber seed oil,obtained through hexane extraction using the Soxhlet method,contains the major fatty acids of oleic acid(C_(18:1)),palmitic acid(C_(16:0)),linoleic acid(C_(18:2)),and stearic acid(C_(18:0)),while rubber seed oil primarily consists of linoleic acid(C_(18:2)),oleic acid(C_(18:1)),linolenic acid(C_(18:3)),palmitic acid(C_(16:0)),and stearic acid(C_(18:0)).The least acid value of lard oil(0.55 mg KOH/g)can benefit of reducing soap formation of rubber seed oil during transesterification process in biodiesel production due to its substantial-high acid value(16.28 mg KOH/g).Blending at ratios below 80:20 volume ratio produced biodiesel exceeding 85%,utilizing CaO as a catalyst.Lard oil demonstrated a higher reaction rate constant(11.88×10^(-3)min^(-1))than rubber seed oil(2.11×10^(-3)min^(-1)),indicating a significant difference in performance.High acid value and free fatty acids in rubber seed oil correlated with lower reaction rates.Maintaining a mixture ratio below 80:20 volume ratio optimized reaction rates during biodiesel production.Biodiesel obtained from blends below 80:20 volume ratio met ASTM D6751 and EN 14214 standards,demonstrating suitability for bio-auto fuel.The drawbacks of using rubber seed oil as a raw material for biodiesel production are overcome by blending with lard oil,giving rise to expanding renewable energy options for rural communities,community enterprises,and large-scale biodiesel production.

Flavonoids from mulberry leaves inhibit fat production and improve fatty acid distribution in adipose tissue in finishing pigs

This study evaluated the effects of flavonoids from mulberry leaves(FML)on plasma biochemical indices,serum activities of lipid metabolism-related enzymes,fat morphology,fatty acid composition,and lipid metabolism in different adipose tissues of finishing pigs.We used 120 Chinese hybrid barrows of Berkshire and Bama mini-pigs with an average initial body weight of 45.11±4.23 kg.The pigs were randomly assigned to five treatment groups and fed a control diet based on corn,soybean meal,and wheat bran or a control diet supplemented with 0.02%,0.04%,0.08%,or 0.16%FML.Each experimental group had six replicates(pens),with four pigs per pen.After a 7-d adaptation period,the feeding trial was conducted for 58 d.Blood and adipose tissue samples were collected from 30 pigs(one pig per pen)at the end of the test.The results showed that FML supplementation significantly decreased the feed intake to body gain ratio,the plasma concentrations of total cholesterol and free fatty acids,and the serum activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase(linear or quadratic effects,P<0.05),and decreased the plasma triglyceride concentration(quadratic,P=0.07).Increasing FML supplementation increased the average daily gain and serum activities of lipoprotein lipase(linear and quadratic effects,P<0.05)and adipose triglyceride lipase(linear,P<0.05).Dietary FML supplementation decreased the adipocyte area in the dorsal subcutaneous adipose(DSA)tissue of finishing pigs(linear,P=0.05)and increased the adipocyte area in the visceral adipose tissue(quadratic,P<0.01).Increasing FML supplementation decreased the C20:1 content in DSA,abdominal subcutaneous adipose,and visceral adipose tissues of finishing pigs(P<0.05)and increased the C18:3n3 and n-3 PUFA contents(P<0.05).The lipid metabolism genes were regulated by the PPARγ-LXRa-ABCA1 signaling pathway,and their expressions differed in different adipose tissues.These findings suggest that FML improved growth performance,regulated lipid metabolism,inhibited fat production,and improved fatty acid distribution in the adipose tissue of finishing pigs,thereby improving pig fat's nutritional quality and health value.

Graphene-and Multi-Walled Carbon Nanotubes-Coated Tapered Plastic Optical Fiber for Detection of Lard Adulteration in Olive Oil

A rapid and high-performance sensor for lard adulterant in edible oil was developed using the tapered plastic optical fiber(POF)coated with graphene and multi-walled carbon nanotubes.The coating material was deposited onto a tapered POF with a taper waist diameter and a taper length of 0.45 mm and 1 cm,respectively.The addition of the coating material was used to increase the sensitivity and selectivity coefficient of the tapered POF toward the lard substance.The sensing mechanism is based on a simultaneous interaction of lard substance and an evanescent wave of tapered POF with the coating layers.The results showed that graphene coating on the tapered POF increased the selectivity coefficient of the tapered POF towards lard substance from 33.54 to 324.19,and it gave a sensitivity of 0.427 dBm/%.In comparison,multi-walled carbon nanotubes coating increased the selectivity coefficient to 71.65 and increased its sensitivity to 1.189 dBm/%.Thus,the proposed configuration of the tapered POF with the coating material offered a simple configuration for a rapid,high sensitivity and selectivity detection of lard adulterant in edible oils.