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Deng Y.,Shandong University | Tong X.,Shandong University | Liang Z.,Shandong University | Zhao J.,Shandong Marine Resource and Environment Research Institute
Proceedings of the International Offshore and Polar Engineering Conference | Year: 2015

The dynamic mesh technique are used to simulate the circular cylinder motion. An Elastically supported cylinder placed in uniform flow and also in combination of uniform and oscillating flows at low Reynolds number values are simulated. The uniform and oscillating flows are both in the x direction. SIMPLE algorithm is used to solve the Navier-Stokes equations. In the paper, we compute the lift and oscillating motion amplitude as functions of Reynolds number and time at different mass ratios. Simulations show the vortex induced vibration process of an elastically supported circular cylinder in uniform flow and compare the oscillating motion amplitude of cylinder and lift coefficient in combination of uniform and oscillating flow at high and low mass ratio. Copyright © 2015 by the International Society of Offshore and Polar Engineers (ISOPE). Source

Wang Y.,Shandong Normal University | Wang Y.,Shandong Marine Resource and Environment Research Institute | Hou S.,Nanjing University | Sun W.,Shandong Normal University | And 3 more authors.
Climate Dynamics | Year: 2015

Stake measurements at 2 km intervals are used to determine the spatial and temporal surface mass balance (SMB) in recent decades along the Japanese Antarctic Research Expedition traverse route from Syowa Station to Dome F. To determine SMB variability at regional scales, this traverse route is divided into four regions, i.e., coastal, lower katabatic, upper katabatic and inland plateau. We also perform a regional evaluation of large scale SMB simulated by the regional atmospheric climate model versions 2.1 and 2.3 (RACMO2.1 and RACMO2.3), and the four more recent global reanalyses. Large-scale spatial variability in the multi-year averaged SMB reveals robust relationships with continentality and surface elevation. In the katabatic regions, SMB variability is also highly associated with surface slope, which in turn is affected by bedrock topography. Stake observation records show large inter-annual variability in SMB, but did not indicate any significant trends over both the last 40 years for the coastal and lower katabatic regions, and the last 20 years record for the upper katabatic and inland plateau regions. The four reanalyses and the regional climate model reproduce the macro-scale spatial pattern well for the multi-year averaged SMB, but fail to capture the mesoscale SMB increase at the distance interval ~300 to ~400 km from Syowa station. Thanks to the updated scheme in the cloud microphysics, RACMO2.3 shows the best spatial agreement with stake measurements over the inland plateau region. ERA-interim, JRA-55 and MERRA exhibit high agreement with the inter-annual variability of observed SMB in the coastal, upper katabatic and inland plateau regions, and moderate agreement in the lower katabatic region, while NCEP2 and RACMO2.1 inter-annual variability shows no significant correlation with the observations for the inland plateau region. © 2015 Springer-Verlag Berlin Heidelberg Source

Feng J.,Zhejiang University | Chen Y.,Zhejiang University | Liu X.,Shandong Marine Resource and Environment Research Institute | Liu S.,Zhejiang University
Food Chemistry | Year: 2014

Novel strategy of Gemini-like modification has been applied in development of new nonionic surfactants, tea saponin esters, with enhanced surface activity by simple esterification. Tea saponin was treated with acyl chlorides of different chain length and different ratio of tea saponin and acyl chloride under alkaline condition. The structures of tea saponin esters were analysed and confirmed by FT-IR, NMR and ESI-MS. Surface activity investigation revealed that esterification with the chain length of C12 and C14 and the ratio of 1:4 to 1:6 produced superior surface activity compared with tea saponin. The exceptional surface activity of the new surfactants suggested their great potential application in food industry as green surfactants due to their environmental benign nature as well as simple and inexpensive preparation. The strategy of Gemini-like modification will facilitate development of green surfactants based on natural resources. © 2014 Elsevier Ltd. All rights reserved. Source

Wang J.,Shandong Marine Resource and Environment Research Institute | Zhang D.,Shandong Marine Resource and Environment Research Institute | Sun Y.,Shandong Marine Resource and Environment Research Institute | Wang S.,Shandong Marine Resource and Environment Research Institute | And 2 more authors.
Aquaculture Research | Year: 2016

An 8-week feeding trial was conducted to evaluate the effects of a dairy-yeast prebiotic (Grobiotic®-A) on growth performance, body composition, antioxidant capacity and immune functions of juvenile starry flounder, Platichtahys stellatus. Three triplicates of starry flounder (average initial weight of 15.05 ± 0.04 g) were fed one of six diets formulated to supplement dairy-yeast prebiotic at 0%, 0.4%, 0.8%, 1.2%, 1.6% or 2.0% respectively. Results showed that weight gain, daily feed intake, protein efficiency rate and condition factor increased significantly (P < 0.05) whereas feed conversion ratio decreased significantly with the increasing level of the dairy-yeast prebiotic supplement. Crude lipid content in dorsal muscle and liver decreased significantly (P < 0.05). No significant differences occurred in moisture and crude protein content of dorsal muscle and liver with the increasing level of the dairy-yeast prebiotic supplement. Compared with fish feed the basal diet, the activity of catalase and total antioxidant capability in serum and liver, as well as total superoxide dismutase in serum all significantly increased with high level of the prebiotic, while the malondialdehyde content in serum and liver decreased significantly. In serum, the activity of alkaline phosphatase, lysozyme, complement and the content of nitric oxide were significantly increased at higher level of prebiotic supplementation while no significant differences were found in total protein, albumin, globulin, albumin to globulin ratio, haemoglobin, acid phosphatase and myeloperoxidase. Based on weight gain response using the quadratic regression, combine the antioxidant and immune indices, the optimum dietary dairy-yeast prebiotic level for juvenile starry flounder was estimated to be 1.33% under these experimental conditions. © 2016 John Wiley & Sons Ltd. Source

Qiao H.,Shandong Marine Resource and Environment Research Institute | Cong C.,Shandong Marine Resource and Environment Research Institute | Cong C.,Shanghai Ocean University | Sun C.,Shandong Marine Resource and Environment Research Institute | And 3 more authors.
Aquaculture | Year: 2016

The effect of growth phase and environmental factors on growth, fatty acid composition and DHA/EPA ratio of Phaeodactylum tricornutum Bohlin was studied. Microalgae were grown in laboratory batch cultures in f/2 medium. Cultures were grown at different salinities (15, 20, 28, and 35ppt), nitrogen (N) concentrations (1.24, 12.35, 24.70 and 49.40mgL-1), light intensities (50, 100 and 150μmolm-2s-1; 14:10h light:dark cycle) and temperatures (15, 20 and 25°C), and sampled at different points of the respective growth phases (inoculums, early-linear, middle-linear and late-linear phases). Samples were analyzed for biomass weight, fatty acid composition and total fatty acid content (TFAC). The main fatty acids in all culture conditions were C14:0 (5.25%-6.04%), C16:0 (13.96%-14.78%), C16:1n-7 (19.09%-35.73%), C18:1n-9 (5.56%-9.01%) and eicosapentaenoic acid (EPA, 22.81%-30.72%). The percentage of polyunsaturated fatty acids (PUFAs) was reduced while that of monounsaturated fatty acid acids (MUFAs) and TFACs increased with culture time. Salinity had no serious effect on fatty acid composition, however, a significant decline of TFAC was observed at the lowest salinity (p<0.05). Significant (p<0.05) increases of the relative contents of SFAs and MUFAs and a decrease of PUFAs were observed under N-limitation condition. The percentage of docosahexaenoic acid (DHA) was significantly enhanced with increasing light intensity (p<0.05), while that of DHA, EPA and PUFA decreased significantly with increasing temperature (p<0.05). DHA/EPA ratio tended to rise initially and fall later with increasing growth time, and reached the highest level with the lowest salinity, and the lowest temperature and initial N concentration, revealing a possible cell response to the stress brought from the unfavorable conditions. In conclusion, this study demonstrates the variation of growth, fatty acid composition and DHA/EPA ratio with growth phase and environmental factors in P. tricornutum, benefiting the production of PUFA-rich microalgae, with a DHA/EPA ratio optimal for aquaculture live food. Statement of relevance: We conducted detailed analysis on the effect of the culture conditions on growth, fatty acid composition and DHA/EPA ratio in Phaeodactylum tricornutum, a widely used microalga for aquaculture feedstuff in China. We found that the environmental stress conditions increased DHA/EPA ratio. The research will benefit the production of PUFA-rich and DHA/EPA-ratio-optimal microalgae for aquaculture feedstuff. © 2015 Elsevier B.V. Source

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