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51.

Purpose

Cohesive sediment is able to flocculate and create flocs, which are larger than individual particles and less dense. The phenomenon of flocculation has an important role in sediment transport processes such as settling, deposition and erosion. In this study, laboratory experiments were performed to investigate the effect of key hydrodynamic parameters such as suspended sediment concentration and salinity on floc size and settling velocity. Results were compared with previous laboratory and field studies at different estuaries.

Materials and methods

Experimental tests were conducted in a 1-L glass beaker of 11-cm diameter using suspended sediment samples from the Severn Estuary. A particle image velocimetry system and image processing routine were used to measure the floc size distribution and settling velocity.

Results and discussion

The settling velocity was found to range from 0.2 to 1.2 mm s?1. Settling velocity changed in the case of increasing suspended sediment concentration and was controlled by the salinity. The faster settling velocity occurred when sediment concentration is higher or the salinity is lower than 2.5. On the other hand, at salinities higher than 20, in addition to increasing SSC, it was found that the situation was reversed, i.e. the lower the sediment concentration, the faster the settling velocity.

Conclusions

Sediment flocculation is enhanced with increasing sediment concentration but not with increasing salinity.
  相似文献   
52.
Pomegranate peel is inherited with diverse functional properties that improve storage stability and nutritional quality of edible goods. This research was aimed at evaluating antioxidant and antimicrobial properties of pomegranate peel hydro-alcoholic extracts and to determine in situ efficacy of extracts in controlling microbial growth and lipid oxidation of shrimp meat. The results suggest that pomegranate peel ethanolic extracts (PoPetx) have significantly higher (p < 0.05) phenolic contents, 169 mg GAE/100 g accompanied with 90% free radical scavenging activities. Contrary to the normal control, incorporation of PoPetx @ 2.0% (w/w) in minced shrimp meat increased thiobarbituric acid reactive species generation by 10% during 28 days of storage at 4°C. Supplementing PoPetx @ 0.5–2.0% (w/w) to shrimp meat has shown a comparable microbial inhibitory action against total plate counts and Staphylococcus spp. The study concludes that application of pomegranate peel extracts in minced shrimp is a viable strategy to preserve chemical and microbiological quality of shrimp and products of sea origin.  相似文献   
53.
ABSTRACT

Breading and battering of fish results in a physically superior product with a higher economic value from low-value fish. The present work was undertaken to evaluate three conventional breading materials for fish cutlets. Standard sized fish cutlets were molded with and dipped in a batter mix, followed by breading with bread crumbs (CB), pressed rice (PR), or noodle vermicelli (NS). The products were evaluated for coating parameters such as pickup, adhesion degree, cooking loss, and frying yield. The coating pickup ranged from 10.95% to 36.00%, and a maximum pickup was found with pressed rice (PR). Similarly, the adhesion degree in PR was 26.47%, which was highest among the three. Cooking loss was highest with control (conventional breadcrumb) at 15.92%. After analyzing the frying yield, it was found that PR yielded the maximum at 16.75% and less oil absorption. PR also had significantly (p < .05) higher hue angle value than both the NS and CB. Maximum browning and tough texture was observed in the NS sample. Frying tolerance was better with PR breading, which maintained better color during deep frying operations. This study can help industries to utilze low-cost breading material in preparing enrobed snack products.  相似文献   
54.
Abstract

We investigated the effect of foliar application of potassium nitrate (KNO3) and zinc sulfate (ZnSO4) on the fruit quality of pomegranate (Punica granatum L. cv. Malas-E–Torsh in Saveh). Potassium was applied as KNO3 at concentrations of 0%, 0.25%, and 0.5% and zinc was applied as ZnSO4 at concentrations of 0%, 0.5%, and 1% in a completely randomized block design. To determine the effect of the treatments on fruit quality, we measured fruit weight, peel thickness, aril diameter, phenol content of the juice, pH, total soluble solids (TSS), titratable acidity (TA), and antioxidant capacity. Foliar application of KNO3 significantly increased fruit weight, 100 aril weight, peel weight, peel thickness, TTS, and antioxidant capacity. In contrast, pH, TA, TSS/TA, and phenol content of the juice were not influenced by foliar application of KNO3. ZnSO4 significantly increased fruit weight, aril diameter, and phenol content of the juice. KNO3 1% and ZnSO4 0.5% were identified as the most appropriate treatments in improving quality and quantity of pomegranate. The fatty acid profile of the pomegranate oil was primarily composed of punicic acid, linoleic acid, oleic acid, palmitic acid, and stearic acid.  相似文献   
55.
56.
Research studies on the corelation of growth and yield as affected by different levels of Nitrogen in Feutrell's Early revealed that the yield is directly responsible for growth. Increasing nitrogen level increase the growth and yield of plants upto a certain limit but when this limit is cro ssed, the growth of tree may increase in terms of girth and height but the spread and yield of the tree is decreased. This indicates the effect of nitrogen in relation of growth and yield.  相似文献   
57.
Inter‐accession variation for salt tolerance of Panicum miliaceum (proso millet) was appraised using leaf proline content and activities of antioxidant enzymes as selection criteria. Eighteen accessions of proso millet were grown under control conditions and after 14 days subjected to saline (120 mm NaCl) stress for 4 weeks. Salt stress substantially decreased relative water content (RWC), while increased leaf free proline and malondialdehyde (MDA) and activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) of all accessions of proso millet. The difference among the accessions of P. miliaceum was significant in yield as well as in the activities of antioxidant enzymes analyses. On the basis of seed yield (expressed as per cent of control), of 18 accessions, three were categorised as salt‐tolerant (008211, 008214 and 008226), seven as moderately tolerant (008210, 008213, 008216, 008220, 008222, 008223 and 008242) and eight as salt‐sensitive (008208, 008215, 008217, 008218, 008221, 008225, 008230 and 008236). Of all P. miliaceum accessions, 008211, 008226, 008215 and 008218 were relatively higher in proline, 008214 and 008221 in MDA contents, 00812, 008225, 008236, 008222 and 008242 in SOD activity and 008218, 008220, 008211 and 008226 in POD and CAT enzyme activities. Thus, because of differential response of high or low seed yielded accessions in accumulation of proline and antioxidant enzyme activities, these variables were not found effective criteria for discriminating the P. miliaceum accessions for salt tolerance.  相似文献   
58.
Irrigated trials were conducted during the dry seasons of 2004, 2005 and 2006 at the Irrigation Research Station of the Institute for Agricultural Research (IAR), Nigeria, to study the performance of three groundnut (Arachis hypogaea L.) varieties as affected by basin size and plant population. Treatments consisting of three basin sizes (3 × 3, 3 × 4 and 3 × 5 m), three plant populations (50,000, 100,000 and 200,000 plants ha?1) and three varieties (Samnut 11, Samnut 21 and Samnut 23), were laid out in a split-plot design with factorial combination of population and variety assigned to the main plots and basin sizes to the subplots. Plant height exhibited the highest positive (p ≤ 0.05) effect of 0.3993, 0.5124, 0.6296 and 0.5897, followed by total dry matter (0.2339, 0.3329, 0.4040 and 0.4197) and number of branches (0.1118, 0.0181, 0.0416 and 0.1541) in the three years and when combined. Path coefficient analysis revealed that among the growth characters selected, plant height made the highest positive contribution of 34.77% to pod yield of groundnut, followed by total dry matter with a positive contribution of 17.46%, suggesting plant height was the most critical growth parameter for determining yield of groundnut under irrigation.  相似文献   
59.
In the present study, 48 crossbred does (Nubian × Baladi) were used to investigate physiological (mucus and hormonal) traits as affected by gestation pattern (pre‐, full‐ and post‐term parturitions). The incidence of full‐term (does with a gestation length of 146–152 days) was the highest (54.5%), followed by pre‐term (does with a gestation length of 140–145 days; 36.9%) and post‐term (does with a gestation length of 153 days; 8.9%), respectively. Prediction of gestation pattern by using some body measurements was also studied. Cervical mucus samples were collected during estrus to determine spinnbarkeit (i.e. strength, viscosity or stretchability) and pH values of the mucus. Mucus was also collected pre‐parturition daily from day 140 of gestation until delivery, to evaluate the ferning arborization. Blood samples were collected on the day before mating (0 time), 1 (at mating), 30, 60, 90 and 145 days after mating. The results showed that spinnbarkeit and pH in cervical mucus at estrus, serum estradiol‐17α (E2) at day 5 before delivery, and progesterone (P4) levels differed insignificantly according to gestation pattern. The fern degree between day 140 of gestation and day of delivery was the highest in pre‐term does, while it was the lowest in post‐ and full‐term does. The gestation length was the highest in post‐term does (157.5 days), and the lowest in pre‐term does (141.5 days). During winter, the incidence of pre‐term deliveries was the highest (54.5%), but in spring, full‐term deliveries were the most common (58.3%). Most of the traits studied were insignificantly affected by season of birth. Post‐term delivery can be estimated by doe weight and wither height, while full‐term delivery can be anticipated using by hip height and abdomen girth. Pre‐term does can be detected by cervical mucus fern between day 140 of gestation and day of delivery. Post‐term does can be defined by doe weight and wither height, while full‐term deliveries can be defined by hip height and abdomen girth, during pregnancy.  相似文献   
60.
Milk yield (MY), composition, and fatty acid profiles of purebred Holstein (HO) cows, Brown Swiss (BS), and their F1 crossbreds (HS) were compared under subtropical climate in Egypt. Pure HO had significantly greater 305-MY, total-MY, and daily-MY (p?<?0.05) than pure BS and crossbred HS. Furthermore, HO and HS had significantly higher peak-MY (44.2 and 43.3 kg, respectively) than BS (36.1 kg). In comparison with HO, BS had significantly higher milk fat, protein, total solids, and solid-not-fat % (p?<?0.05); however, no significant differences were observed between BS and HS for milk fat %. The milk fat of BS had higher concentrations of saturated (C17:0 and C18:0) fatty acids (FA) than that of the HO and HS (p?=?0.001 and 0.008, respectively). Content of C4:0, C6:0, C8:0, C12:0, and C15.0 FA did not differ between genotypes. Milk from HO and BS had significantly higher concentrations of unsaturated (C20:1 and C20:5) FA than that from HS (p?<?0.05). C14:1 (myristoleic), C16:1 (palmitoleic), and C18:2 (linoleic) FA contents were similar for all genotypes. In conclusion, BS surpassed HO for all milk composition traits and some FA components; however, HS had comparable milk fat percentage with BS. There appears to be an opportunity to modify the concentration of certain FA by breeding.  相似文献   
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