Isolation of protein from Chlorella sorokiniana CY1 using liquid biphasic flotation assisted with sonication through sugaring-out effect     

Chia  Shir Reen  Chew  Kit Wayne  Show  Pau Loke  Sivakumar  Manickam  Ling  Tau Chuan  Tao  Yang 《中国海洋湖沼学报》2019,37(3):898-908

Microalgae, a sustainable source of multi beneficial components has been discovered and could be utilised in pharmaceutical, bioenergy and food applications. This study aims to investigate the sugaring-out effect on the recovery of protein from wet green microalga, Chlorella sorokiniana CY1 which was assisted with sonication. A comparison of monosaccharides and disaccharides as one of the phaseforming constituents shows that the monosaccharides, glucose was the most suitable sugar in forming the phases with acetonitrile to enhance the production of protein(52% of protein). The protein productivity of microalgae was found to be significantly influenced by the volume ratio of both phases, as the yield of protein increased to 77%. The interval time between the sonication as well as the sonication modes were influencing the protein productivity as well. The optimum protein productivity was obtained with 10 s of resting time in between sonication. Pulse mode of sonication was suitable to break down the cell wall of microalgae compared to continuous mode as a lower protein yield was obtained with the application of continuous mode. The optimum condition for protein extraction were found as followed: 200 g/L glucose as bottom phase with volume ratio of I:1.25, 10 s of resting time for ultrasonication, 5 s of ultrasonication in pulse mode and 0.25 g of biomass weight. The high yield of protein about 81% could be obtained from microalgae which demonstrates the potential of this source and expected to play an important role in the future.  相似文献   

Limit states and failure mechanisms of viscous dampers and the implications for large earthquakes     

H. Kit Miyamoto  Amir S. J. Gilani  Akira Wada  Christopher Ariyaratana 《地震工程与结构动力学》2010,39(11):1279-1297

Fluid viscous dampers are used to control story drifts and member forces in structures during earthquake events. These elements provide satisfactory performance at the design‐level or maximum considered earthquake. However, buildings using fluid viscous dampers have not been subjected to very large earthquakes with intensities greater than the design and maximum considered events. Furthermore, an extensive database of viscous damper performance during large seismic events does not exist. To address these issues, a comprehensive analytical and experimental investigation was conducted to determine the performance of damped structures subjected to large earthquakes. A critical component of this research was the development and verification of a detailed viscous damper mathematical model that incorporates limit states. The development of this model and the laboratory and simulation results conclude good correlation with the new model and the damper limit states and provide superior results compared with the typical damper model when considering near collapse evaluation of structures. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Spring diet of ringed seals (Phoca hispida) from northwestern Spitsbergen, Norway     

Labansen  Aili L.; Lydersen  Christian; Haug  Tore; Kovacs  Kit M. 《ICES Journal of Marine Science》2007,64(6):1246-1256

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Calibration of JASON-1 Altimeter over Lake Erie     

C. Shum  Y. Yi  K. Cheng  C. Kuo  A. Braun  S. Calmant  D. Chambers 《Marine Geodesy》2003,26(3):335-354

This article describes absolute calibration results for both JASON-1 and TOPEX Side B (TSB) altimeters obtained at the Lake Erie calibration site, Marblehead, Ohio, USA. Using 15 overflights, the estimated JASON altimeter bias at Marblehead is 58 ± 38 mm, with an uncertainty of 19 mm based on detailed error analysis. Assuming that the TSB bias is negligible, relative bias estimates using both data from the TSB-JASON formation flight period and data from 48 water level gauges around the entire Great Lakes confirmed the Marblehead results. Global analyses using both the formation flight data and dual-satellite (TSB and JASON) crossovers yield a similar relative bias estimate of 146 ± 59 mm, which agrees well with open ocean absolute calibration results obtained at Harvest, Corsica, and Bass Strait (e.g., Watson et al. 2003). We find that there is a strong dependence of bias estimates on the choice of sea state bias (SSB) models. Results indicate that the invariant JASON instrument bias estimated oceanwide is 71 mm, with additional biases of 76 mm or 28 mm contributed by the choice of Collecte Localisation Satellites (CLS) SSB or Center for Space Research (CSR) SSB model, respectively. Similar analysis in the Great Lakes yields the invariant JASON instrument bias at 19 mm, with the SSB contributed biases at 58 mm or 13 mm, respectively. The reason for the discrepancy is currently unknown and warrants further investigation. Finally, comparison of the TOPEX/POSEIDON mission (1992-2002) data with the Great Lakes water level gauge measurements yields a negligible TOPEX altimeter drift of 0.1 mm/yr.  相似文献   

Bromide as a conservative tracer for soil-water studies     

B. S. Levy  R. M. Chambers 《水文研究》1987,1(4):385-389

The assumption that potassium bromide is a conservative tracer for soil-water studies was tested in a series of batch sorption experiments. Sorption experiments were conducted on soil samples collected from the O, E, and A horizons of the Albemarle soil series near Charlottesville, VA. The experiments were conducted under conditions of differing bromide concentration and filter treatments. Bromide concentrations in soil-solution mixtures were measured through time using an Orion bromide-specific electrode. An analysis of variance of results showed no significant sorption of bromide through time under any concentration level or filter treatment (α = 0·01). No sorption of bromide between different soil horizons could be determined. This work clearly indicates that bromide is conservative under the conditions examined.  相似文献   

Distribution and nutrient status of haplotypes of the marsh grassPhragmites australis along the Rappahannock River in Virginia     

C. Rebekah Packett  Randolph M. Chambers 《Estuaries and Coasts》2006,29(6):1222-1225

We compared the distribution and nutrient status of native haplotype F ofPhragmites australis along the freshwater to mesohaline tidal marsh gradient of the Rappahannock River, Virginia, for comparison with the nonnative, invasive haploty M. Using GIS analysis of aerial photography and GPS-based ground truthing, we identified 55 separate clones of native haplotype F comprising a total of 3.68 ha (range 0.002–0.734 ha), all found in tidal wetlands where surface water salinity was 0 psu. We identified 219 separate clones of the invasive haplotype M covering 68.3 ha along the same stretch of river (range 0.004–11.86 ha), found in wetlands where salinity ranged from 0 to 11 psu. From 15 separate clones for each haplotype, average carbon content in leaves of the native was significantly higher than the invasive (43.90±0.08% versus 42.82±0.15%, F_1,28=20.938, p<0.01), and nitrogen content was significantly lower (2.22±0.03% versus 2.58±0.07%, F_1,28=11.972, p<0.01). The average C:N:P ratio for leaf tissue was 1100∶48∶1 for haplotype F and 1084∶56∶1 for haplotype M. Relative to the native, the invasive haplotype forms larger stands distributed throughout a broader estuarine reach and incorporates more nitrogen in leaf tissue. From a management standpoint, nativePhragmites protection should focus on deterring nonnative haplotype invasion through the minimization of both adjacent upland disturbance and nutrient enrichment in tidal freshwater marshes.  相似文献   

Investigating the lowermost mantle using migrations of long-period S–ScS data     

K. Chambers  J. H. Woodhouse 《Geophysical Journal International》2006,166(2):667-678

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Relative importance of the Hercynian and post-Jurassic tectonic phases in the Saharan platform: a palaeomagnetic study of Jurassic sills in the Reggane Basin (Algeria)   总被引：2，自引：0，他引：2  

B. Smith  M. E. M. Derder  B. Henry  B. Bayou  A. K. Yelles  H. Djellit  M. Amenna  M. Garces  E. Beamud  J. P. Callot  R. Eschard  A. Chambers  T. Aifa  R. Ait Ouali  H. Gandriche 《Geophysical Journal International》2006,167(1):380-396

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Integrated Approaches,Multiple Scales: Snag Dynamics in Burned Versus Unburned Landscapes*     

Joy Nystrom Mast  Carol L. Chambers 《The Professional geographer》2006,58(4):397-405

By studying landscape form and patterns, we can study processes at multiple scales and determine how collectively those processes inform us about function(s). Integrating landscape ecology from a biogeographical perspective with geographic information science (GIScience) practices offers new ways to study how landscapes change over time and space, including how they can be measured, analyzed, and modeled for management needs. This article presents methodologies and selected results of analyzing spatial patterns from field data across multiple scales by examining standing dead tree (snag) processes across wildfire‐disturbed landscapes in Arizona. Our primary motivation was to illustrate a particular type of work benefiting from the coalescing of landscape ecology and GIScience, functioning at the methodological and practical overlap of these two contributing fields. Our management goals were to (1) describe spatial patterns and characteristics of snags in pairs of burned and unburned ponderosa pine forests of Arizona in four recent (within the past ten years) wildfires, (2) document bird response to wildfires by combining landscape ecology and GIScience methods, and (3) link these patterns to snag monitoring plots and cavity‐nesting bird use to predict the probability of snag use by birds and cavity nesters based on snag characteristics (snag use model). The methods and results demonstrate how integration of landscape ecology with both GIS and GIScience improves the ways to study landscapes and land management issues, in this case offering guidelines for retention of snags that provide habitat for wildlife.  相似文献   

GGM02 – An improved Earth gravity field model from GRACE     

B. Tapley  J. Ries  S. Bettadpur  D. Chambers  M. Cheng  F. Condi  B. Gunter  Z. Kang  P. Nagel  R. Pastor  T. Pekker  S. Poole  F. Wang 《Journal of Geodesy》2005,79(8):467-478

A new generation of Earth gravity field models called GGM02 are derived using approximately 14 months of data spanning from April 2002 to December 2003 from the Gravity Recovery And Climate Experiment (GRACE). Relative to the preceding generation, GGM01, there have been improvements to the data products, the gravity estimation methods and the background models. Based on the calibrated covariances, GGM02 (both the GRACE-only model GGM02S and the combination model GGM02C) represents an improvement greater than a factor of two over the previous GGM01 models. Error estimates indicate a cumulative error less than 1 cm geoid height to spherical harmonic degree 70, which can be said to have met the GRACE minimum mission goals. Electronic Supplementary Material Supplementary material is available in the online version of this article at  相似文献