GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    An Investigation of Two Kinds of Magnetic Chitosan Composite Microspheres
    SAGE Publications ; 2007
    In:  Journal of Bioactive and Compatible Polymers Vol. 22, No. 4 ( 2007-07), p. 429-441
    Details
    In: Journal of Bioactive and Compatible Polymers, SAGE Publications, Vol. 22, No. 4 ( 2007-07), p. 429-441
    Abstract: In this study, two composite magnetic microspheres made of tamarind gum with chitosan and artemisia seed gum with chitosan were prepared by suspension cross-linking for magnetic carrier applications. The magnetic material used in the preparation of the microspheres was prepared by precipitating FeCl3 and FeSO4 solutions in a basic medium. The morphological, thermal stability, and magnetic properties of the two composite magnetic microspheres were characterized by scanning electron microscope, magnetometry, and differential scanning calorimeter (DSC). The swelling kinetics and pH responsive behavior of the two microspheres were also studied.
    Type of Medium: Online Resource
    ISSN: 0883-9115 , 1530-8030
    URL: Article
    DOI: 10.1177/0883911507079967
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2007
    detail.hit.zdb_id: 2073790-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Theory and preliminary experimental verification of the directional difference of overland flow resistance in distributed hydrological models
    IWA Publishing ; 2018
    In:  Water Supply Vol. 18, No. 6 ( 2018-12-01), p. 2142-2150
    Details
    In: Water Supply, IWA Publishing, Vol. 18, No. 6 ( 2018-12-01), p. 2142-2150
    Abstract: Overland flow is influenced by the spatial variability of the watershed surface and the distribution of vegetation in the process of confluence. Thus, Manning's roughness coefficient, in different directions on the slope, has different values. This causes different effects on the resistance to flow in the downstream direction of each grid cell, affecting the flow distribution among the grid cells of a distributed hydrological model. To show that the spatial variation of the overland vegetation had the effect of directional difference resistance to the overland flow, this study used an indoor fixed-bed test. We used a cylinder to simulate the stems of the vegetation used in the study. We modeled the relationship between Manning's roughness coefficient and flow depth and studied this relationship for three types of vegetation distributed at three different slopes of 0.0%, 0.5%, and 1.0%. The slopes were based on three angles of 30°, 45°, and 90° between the vegetation rows and flow. The results showed that the resistance of overland flow had directional differences caused by the spatial variability of the vegetation distribution. At the same slope and flow depth, Manning's roughness coefficient decreased as the angle between flow and vegetation rows increased. At the same slope, the angle between flow and vegetation rows and Manning's roughness coefficient increased as flow depth increased. The slope did not affect the law of Manning's roughness coefficient with changes in the angle between flow and vegetation rows.
    Type of Medium: Online Resource
    ISSN: 1606-9749 , 1607-0798
    URL: Article
    DOI: 10.2166/ws.2018.040
    RVK:
    ZI 6705
    Language: English
    Publisher: IWA Publishing
    Publication Date: 2018
    detail.hit.zdb_id: 2967640-X
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Overland Flow Resistance Law under Sparse Stem Vegetation Coverage
    MDPI AG ; 2021
    In:  Water Vol. 13, No. 12 ( 2021-06-14), p. 1657-
    Details
    In: Water, MDPI AG, Vol. 13, No. 12 ( 2021-06-14), p. 1657-
    Abstract: To explore the characteristics of overland flow resistance under the condition of sparse vegetative stem coverage and improve the basic theoretical research of overland flow, the resistance characteristics of overland flow were systematically investigated under four slope gradients (S), seven flow discharges (Q), and six degrees of vegetation coverage (Cr). The results show that the Manning roughness coefficient (n) changes with the ratio of water depth to vegetation height (h/hv) while the Reynolds number (Re), Froude number (Fr), and slope (S) are closely related to vegetation coverage. Meanwhile, h/hv, Re, and Cr have strong positive correlations with n, while Fr and S have strong negative correlations with n. Through data regression analysis, a power function relationship between n and hydraulic parameters was observed and sensitivity analysis was performed. It was concluded that the relationship between n and h/hv, Re, Cr, Q, and S shows the same law; in particular, for sparse stem vegetation coverage, Cr is the dominant factor affecting overland flow resistance under zero slope condition, while Cr is no longer the first dominant factor affecting overland flow resistance under non-zero slope condition. In the relationship between n and Fr, Cr has the least effect on overland flow resistance. This indicates that when Manning roughness coefficient is correlated with different hydraulic parameters, the same vegetation coverage has different effects on overland flow resistance. Therefore, it is necessary to study overland flow resistance under the condition of sparse stalk vegetation coverage.
    Type of Medium: Online Resource
    ISSN: 2073-4441
    URL: Article
    DOI: 10.3390/w13121657
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2521238-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Immobilized β-galactosidase: Preparation and Characterization
    SAGE Publications ; 2006
    In:  Polymers and Polymer Composites Vol. 14, No. 8 ( 2006-11), p. 813-823
    Details
    In: Polymers and Polymer Composites, SAGE Publications, Vol. 14, No. 8 ( 2006-11), p. 813-823
    Abstract: A new enzyme support consisting of magnetic composite microspheres was prepared using artemisia seed gum, chitosan and magnetic fluid as a source, and characterized. The microspheres contained reactive aldehyde groups that react with the free amino groups of the enzymes. The β-galactosidase was largely immobilized by covalent binding to the surface of the activated magnetic carriers. The factors controlling the relative activity and the enzymic properties of the immobilized β-galactosidase were compared with those of its soluble counterpart, for which ONPG (o-nitrophenol β-D-galactopyranoside) was chosen as a substrate. The pH and thermal stability of the immobilized β-galactosidase were higher than those of the soluble one. The Michaelis constant, Km, was evaluated both for the immobilized β-galactosidase and for the soluble enzyme. The immobilized type exhibited better environmental adaptability and re-usability than the soluble one.
    Type of Medium: Online Resource
    ISSN: 0967-3911 , 1478-2391
    URL: Article
    DOI: 10.1177/096739110601400806
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2006
    detail.hit.zdb_id: 2099644-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    Irisin participates in the beneficial effects of exercise in preventing gestational diabetes mellitus in overweight and obese pregnant women and a mouse model
    Frontiers Media SA ; 2023
    In:  Frontiers in Nutrition Vol. 9 ( 2023-1-19)
    Details
    In: Frontiers in Nutrition, Frontiers Media SA, Vol. 9 ( 2023-1-19)
    Abstract: We aimed to explore whether irisin participates in the beneficial effects of exercise in preventing gestational diabetes mellitus (GDM) in overweight and obese pregnant women. Study design Sixty overweight and obese pregnant women each in the exercise and control groups were randomly selected from our previous randomized controlled trial. Eighteen obese model mice were generated and divided into exercise and control groups in which body weight, abdominal circumference, anal temperature, glucose tolerance test, and insulin tolerance test were recorded. The plasma irisin level, the expression of PGC-1 α /FNDC5 and brown ( UCP1 ) and beige adipose ( CD137 , TMEM26 , and TBX-1 ) marker genes were detected in muscle and adipose tissue. Results In the human study, women in the exercise group had a significantly higher irisin level and lower insulin resistance level than those in the control group. Enhanced expression of beige adipose tissue marker genes ( CD137 , TMEM26 , and TBX-1 ) in omental adipose tissue and the CD137 gene in subcutaneous adipose tissue were found in the exercise group compared to the control group. In a mouse model, body weight and abdominal circumference were decreased, while glucose homeostasis and insulin sensitivity were significantly improved, and anal temperature was elevated after exercise intervention. A significantly higher level of irisin was revealed in the exercise group after undergoing exercise treatment. The expression of the beige adipose marker genes CD137 and TBX-1 was significantly higher in the exercise group than in the control group in posterior subcutaneous adipose tissue from the inguinal area and interscapular adipose tissue respectively. Conclusion Our observations show that regular exercise during pregnancy can increase irisin levels, promote white fat beiging/browning, improve glucose homeostasis and enhance body energy expenditure, which may be one of the mechanisms by which exercise prevents GDM.
    Type of Medium: Online Resource
    ISSN: 2296-861X
    URL: Article
    DOI: 10.3389/fnut.2022.1034443
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2023
    detail.hit.zdb_id: 2776676-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 6
    Online Resource
    Online Resource
    Preparation and Characterization of Composite Magnetic Microspheres
    SAGE Publications ; 2007
    In:  Journal of Composite Materials Vol. 41, No. 14 ( 2007-07), p. 1703-1712
    Details
    In: Journal of Composite Materials, SAGE Publications, Vol. 41, No. 14 ( 2007-07), p. 1703-1712
    Abstract: In this study, composite magnetic microspheres of tamarind gum and chitosan were prepared in a well-shaped spherical form with a size range of 230—46 0 μm by the suspension cross-linking technique for use in the application of magnetic carrier technology. The magnetic material used in the preparation of the microspheres was prepared by precipitation from FeCl 3 and FeSO 4 solutions in basic medium. The morphological, magnetic properties and the functional groups of the microspheres were characterized by different techniques (i.e., Scanning Electron Microscope (SEM), magnetometry, and FT-IR). The results demonstrated that the stirring rate of the suspension and the Fe 3 O 4 /chitosan ratio are the most effective parameters for the size/size distribution and the magnetic quality of the microspheres, while the amount of tamarind gum has no significant effect on these properties. The best magnetic quality of the microspheres is around 4.11 emu/g microspheres at 8 KG magnetic field intensity. The thermal stability was measured by using DSC methods.
    Type of Medium: Online Resource
    ISSN: 0021-9983 , 1530-793X
    URL: Article
    DOI: 10.1177/0021998306069887
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2007
    detail.hit.zdb_id: 160490-9
    detail.hit.zdb_id: 2081924-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 7
    Online Resource
    Online Resource
    Influence of vegetation lodging on the flow regime and resistance characteristic of overland flow
    Wiley ; 2023
    In:  Hydrological Processes Vol. 37, No. 3 ( 2023-03)
    Details
    In: Hydrological Processes, Wiley, Vol. 37, No. 3 ( 2023-03)
    Abstract: Vegetation lodging downstream under overland flow is a common phenomenon; it changes the characteristics of the overland flow regime and causes the resistance effect. At present, there are few studies on the hydraulic characteristics of the slope flow caused by vegetation lodging, and the problem of the flow resistance of the vegetation morphology has been neglected or simplified, which is likely to cause large deviations in overland flow forecast. To clarify the effect of vegetation lodging on overland flow, under the conditions of slope (0.0%–3.0%) and flow discharge (0.0005–0.008 m 3 /s), an indoor flume experiment of vegetation gradient lodging combination and lodging angle was carried out, and the resistance mechanism and flow regime characteristics were compared and discussed. The results show that it is reasonable to use a uniform lodging angle to simulate the influence of gradient lodging on the overland flow resistance. The slope and vegetation lodging states are important factors that affect the evolution of flow patterns and turbulence changes. It was found that, as the slope or degree of vegetation lodging increased, the flow patterns evolved from slow to rapid. Under the same flow discharge, the resistance of overland flow decreased with an increase in the vegetation lodging angle. Under unsubmerged conditions, the resistance coefficient f was found to be positively correlated with the Reynolds number Re and the cosine of the lodging angle θ , and negatively correlated with the slope S . Compared with vertical vegetation, the morphological resistance of vegetation with lodging angles of 20°, 40°, 60°, and 80° decreased by 10.28%, 32.53%, 52.45%, and 61.37%, respectively. The morphology of vegetation lodging is the main influencing factor that constitutes flow resistance and controls hydraulic erosion. This study provides a theoretical basis for the prediction of overland flow and soil erosion control.
    Type of Medium: Online Resource
    ISSN: 0885-6087 , 1099-1085
    URL: Issue
    URL: Article
    DOI: 10.1002/hyp.v37.3
    DOI: 10.1002/hyp.14848
    Language: English
    Publisher: Wiley
    Publication Date: 2023
    detail.hit.zdb_id: 1479953-4
    SSG: 14
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 8
    Online Resource
    Online Resource
    Numerical study of the effects of vegetation stem thickness on the flow characteristics of curved channels
    IWA Publishing ; 2024
    In:  Water Supply ( 2024-06-26)
    Details
    In: Water Supply, IWA Publishing, ( 2024-06-26)
    Abstract: A curved channel is a common flow form in nature, often hosting aquatic vegetation along rivers. The stem thickness of this vegetation affects its resistance to flow and subsequently influences flow characteristics. To explore the impact of stem thickness on river flow in curved channels, we developed a Reynolds stress model based on real river flow conditions and vegetation data. The flow characteristics were analyzed in terms of flow velocity, Reynolds stress and turbulence intensity by varying the stem thickness of the vegetation in the vegetated area. The results of the study reveal that: (1) Water velocity in the vegetated area is significantly reduced compared to the non-vegetated area, with a greater reduction observed for thicker stems. Increasing the vegetation diameter by 3 mm resulted in a velocity decrease of 2.31–26.55%. (2) Thicker vegetation stems lead to more intense energy exchange in water flow. A 3 mm increase in vegetation diameter increased Reynolds stress by 91.81–139.70%. (3) Turbulent kinetic energy in the vegetated area is significantly higher than in the non-vegetated area, with greater turbulence intensity observed for thicker vegetation stems. Increasing the vegetation diameter by 3 mm resulted in a turbulent kinetic energy increase of 115.19–218.55%.
    Type of Medium: Online Resource
    ISSN: 1606-9749 , 1607-0798
    URL: Article
    DOI: 10.2166/ws.2024.153
    RVK:
    ZI 6705
    Language: English
    Publisher: IWA Publishing
    Publication Date: 2024
    detail.hit.zdb_id: 2967640-X
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 9
    Online Resource
    Online Resource
    Immobilization of β-galactosidase on Tamarind Gum and Chitosan Composite Microspheres
    SAGE Publications ; 2006
    In:  Journal of Bioactive and Compatible Polymers Vol. 21, No. 5 ( 2006-09), p. 415-432
    Details
    In: Journal of Bioactive and Compatible Polymers, SAGE Publications, Vol. 21, No. 5 ( 2006-09), p. 415-432
    Abstract: A new composite microsphere support was prepared and characterized using tamarind gum and chitosan as a source. These new composite microspheres were prepared as well-shaped spheres in range of 230 to 460 m by suspension cross-linking technique. The composite microspheres had better stability in acid and alkaline environments with a swelling volume of 2.34mL/g; the thermal stability of the spheres was better than pure chitosan microspheres. The optimal pH of the immobilized enzyme is pH 8.3 and the optimal temperature is 42°C. The specific activity was 1.6u/g of microspheres and the Michaelis constant was 6.62 10 4. A modified and immobilized enzyme was characterized by means of infrared spectrometry, X-ray photoelectron spectroscopy, and elementary analysis.
    Type of Medium: Online Resource
    ISSN: 0883-9115 , 1530-8030
    URL: Article
    DOI: 10.1177/0883911506068553
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2006
    detail.hit.zdb_id: 2073790-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 10
    Online Resource
    Online Resource
    Synthesis and characterization of composite magnetic microspheres of artemisia seed gum and chitosan
    Wiley ; 2007
    In:  Journal of Applied Polymer Science Vol. 103, No. 5 ( 2007-03-05), p. 3045-3049
    Details
    In: Journal of Applied Polymer Science, Wiley, Vol. 103, No. 5 ( 2007-03-05), p. 3045-3049
    Type of Medium: Online Resource
    ISSN: 0021-8995 , 1097-4628
    URL: Issue
    URL: Journal
    URL: Article
    DOI: 10.1002/app.v103:5
    DOI: 10.1002/(ISSN)1097-4628
    DOI: 10.1002/app.25438
    Language: English
    Publisher: Wiley
    Publication Date: 2007
    detail.hit.zdb_id: 1491105-X
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...