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  • 신개념 Tube Rheometer for Bio and Industrial Fluids
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  • MCIK
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  • 2010-11-26 (금) 14:16

    저희  MCIK는 최근 미국 Texas 주의 Austin에  위치하고 있는 Vilastic Scientific Inc.  사와   

     Official Exclusive Distributor in Korea 로써  공식 대리점 계약을 체결하여  2008년 7월부터 한국내에서도 Vilastic Scientific Inc. 사의  정밀 기기 판매가  가능 해졌습니다. 

           


     미국 Vilastic Scientific Inc.  사의 주력 품목들은   극소량 (1~3ml)  및 초저점도  (0.5 mPas / 물보다 낮은 점도 측정 가능)    의  다양한  점탄성 유체 시료 및  Bio-Fluids 의  Rheological characterization  용도로 (점도 및 G'  탄성 계수 및  Tangent delta 등 측정 가능)  사용되고  있습니다.   현재 코팅액, 젤, 고분자 용액 및 미네랄오일 등 다양한  분야에서 사용되고 있으나 특히 혈액 및 생체액의 유변 물성 측정 관련 의과대,  약학대 및 인공 심장등을 개발하고 있는 기계공학과 등에서 많은 수요가 있는 품목 입니다.
    Controlled oscillatory flow in a cylindrical tube 를 기초로 측정하여 일반 회전 레오미터에서 문제가 되는  Rotational inertia, surface tension effects, dimensional reproducibility of fixtures, messy fluid handling,  difficulty of controlling temperature and lack of sensitivity 등의 영향을 받지않고 정확하고 재현성높은  측정을 수행 하실수 있습니다. 

    VSIbanner3.GIF (15325 bytes)


     

    "Vilastic Viscoelasticity Analyzers are the most sensitive instruments
    available for rheological analysis of a wide range of viscous
    and viscoelastic liquids--even fluids as thin as water--

    with unparalleled precision."


    Vilastic Scientific  provides exceptional technical backup
    and unmatched rheological expertise.




     

    V-E System for Industrial Rheology
    Designed for a broad range of fluids including inks, polymers, thickeners and hydrocolloids. System Enhancements are available for extensional viscoelasticity, electrorheology, porous media and microcapillaries.

    VE System

    ??? INTRODUCING ???

    BioProfiler for Blood and Plasma Rheology
    An innovative system dedicated to the measurement of blood viscoelasticity and plasma viscosity. 

    Biosm.jpg (15422 bytes)

    Vilastic-3 for Biofluid Rheology
    Simple, rapid, precautionary handling of blood, synovial fluid, biopolymers, protein solutions and other biofluids.  System Enhancements are available for extensional viscoelasticity, porous media and microcapillaries.

    Vilastic-3

     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
    Instruments from Vilastic Scientific have unique sensitivity and precision that go beyond the c onventional rotational rheometers.  
    The VE System is designed for commercial fluids. 
    The Vilastic-3 is designed for biological fluids and aqueous fluids
    and the BioProfiler is designed specifically for blood and plasma.  
     
    Instruments from Vilastic Scientific  have found wide use in a variety of companies and institutions such as Fuji, Procter & Gamble, Penn State University, University of Birmingham and many others. 
     

     
     
    PRINCIPLE OF MEASUREMENT

    Vilastic measurements are based on controlled oscillatory flow in a cylindrical tube. The steady rotational method invented by M. Couette in the 19th century was sufficient for simple fluids. However, with the need to understand complex viscoelastic fluids, sensitive dynamic methods are required. Vilastic has developed the tube flow method to provide the sensitivity necessary to make these measurements.
    Tube flow overcomes many problems of rotational instruments that have been adapted to oscillatory flow, such as rotational inertia, surface tension effects, dimensional reproducibility of fixtures, messy fluid handling, difficulty of controlling temperature and lack of sensitivity. The cylindrical tube is an ideal sample confinement geometry because of its unvarying dimensions. It also provides a maximum sample volume with the theoretically desired flow and a wide selection of confinement materials, including glass. The Vilastic system is so sensitive that water is used as a rheological standard for instrument calibration.
    Measurements are performed using oscillatory flow generated at a selected frequency in a precision measurement tube. Sensors monitor the pressure drop across the tube and volume flow through the tube. Resolution of magnitude and phase of the pressure and volume flow allows calculation of the viscous and elastic components of the shear stress, shear rate and shear strain at the tube wall. From these values the viscosity, elasticity and storage and loss moduli are obtained. In addition, many applications are directly concerned with tube flow of rheologically important fluids and the Vilastic instruments provide direct information on pressure, volume flow, and impedance.  
     

    Vilastic V-E SYSTEM

    A unique instrument with the ability to perform precise measurements of viscosity and elasticity of ultra thin fluids--the consistency of water--as well as thicker fluids.

    Small footprint, small sample size, controlled thermal environment and portability all add versatility and power to this instrument.

    V-E System Photo

    Use the V-E SYSTEM to explore the properties of your liquid by measuring both the viscosity and elasticity over a wide range of values of frequency, shear stress, shear rate, shear strain, time and temperature. Once you select a measurement protocol, you can repeat it at any time with high precision because the unvarying geometry of the V-E SYSTEM eliminates the mechanical adjustments and dimensional inaccuracies of traditional rotational instruments.

    Computer controlled protocols and data processing mean precisely timed measurement sequences, high volume of measurements and disk storage of all results.

    FEATURES

    • Uses water as calibration fluid, a universal standard readily available at no cost
    • Fixed tube sample geometry provides superior reproducibility
    • Resident temperature sensor and clock provide record of thermal conditions and time of measurement
    • Printed data tables together with screen and printer graphics give instantaneous visual presentation of results and hard copy suitable for publication
    • All measurements are subjected to diagnostics for proper instrument operation
    • Each measurement produces 29 parameters for rheological functions, pressure to flow relations, energy storage and loss, and thermal conditions
    • ASCII files can be produced for moving selected data into third party spreadsheet and graphics software for further analysis

      Broaden and deepen your view of rheology with System Enhancements  for   extensional viscoelasticity, electrorheology, porous media and microcapillaries.
      TYPICAL INDUSTRIAL FLUIDS:
      Ink Paper Coatings Paint Beverages
      Shampoo Hair Spray Foams EOR fluids
      Ice Cream Melts Yogurt Gels Microemulsions
      Motor Oil Colloidal Suspensions Polymer Solutions Drilling Muds
      SPECIFICATIONS:

      Shear stress range 0.001 to 1000 dynes/cm2 (0.0001 to 100 Pa) Temperature range 1 to 95 ?C
      Shear rate range 0.01 to 10000/second Frequency range 0.01 to 100 Hertz
      Shear strain range 0.001 to 100 Sample volume 3 ml
      Nominal viscosity 0.005 to 500 Poise (0.0005 to 50 Pa sec) Units selection CGS or SI

      Case size (6" wide by 13 1/2" deep by 8" high)
      Note: specifications vary with the computer and accessories selected.




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      BioProfiler.jpg (20363 bytes)


      *** HIGH PRECISION AT LOW COST ***


      Vilastic Scientific presents the BioProfiler, the only rheometer dedicated to measurements of blood viscoelasticity and plasma viscosity with the sensitivity beyond the capability of conventional rotational rheometers. By measuring both the viscosity and elasticity, the BioProfiler gives physiologically significant characterization of the dynamic flow properties of blood*.


      The BioProfiler fulfills the critical demands of hemorheology with:

      • Measurements performed near the pulse rate
      • Precise vessel-like geometery
      • Simple sample handling and rapid measurements
      • Small sample sizes of 0.5 ml to 1.0 ml
      • Operating temperatures from 10 ?C to 40
      • Automated data analysis
      • Standardized measurement protocols
      • Portability
      making it the first choice for advanced research.

      BLOOD VISCOELASTICITY

      Because blood flow in the circulation is pulsatile, the heart pumps energy into the blood with each beat. Portions of this energy are either dissipated or stored as the blood cells rearrange, orient and deform in order to pass through the circulation. Viscosity is an assessment of the rate of energy dissipation due to cell deformation and sliding. Elasticity is an assessment of the elastic storage of energy primarily in the kinetic deformability of the red blood cells. Together, the viscosity and elasticity determine the pressure required to produce blood flow.

      The relative influence of aggregation tendency and kinetic elastic cell deformability on blood viscoelasticity changes with shear rate (see our Tech Note). The viscosity and elasticity of blood are direct indicators of how these parameters affect the ability of the blood to flow under the shear conditions imposed by the pulsatility of the circulation. Therefore, in order to provide a complete picture of hemorheology, the BioProfiler measures the viscoelasticity for oscillatory flow over a range of shear rates.

      Verticle branch.GIF (9612 bytes)

      Under tightly controlled conditions, the BioProfiler measures the shear rate dependence of blood viscoelasticity utilizing two measurement protocols:

      Shear Rate Sweep Protocol for Comprehensive Characterization

      Critical Three Point Protocol for Simple and Rapid Characterization
      These protocols are governed by Vilatic Software, which controls the timing of flow activation and measurement in order to stabilize the effects of thixotopy.   All measured values undergo complete analysis to give values of the viscosity and elasticity as well as the relaxation time of the blood structure.


      SHEAR RATE SWEEP PROTOCOL


      The Shear Rate Sweep Protocol automatically measures the viscosity and elasticity of blood at a frequency of 2 Hz over a range of shear rates. The timing of each measurement is precisely controlled so that conditions can be duplicated.  Plots of viscosity and elasticity versus shear rate give a profile of the viscoelasticity of the blood in varying structural states. Optional plots of shear stress and relaxation time versus strain or shear rate are also available.  The ASCII output option exports data from several samples into one file, which is compatible with most spreadsheet programs.

      Sweep Plot.GIF (19684 bytes)


      The viscoelastic profile produced by the Shear Rate Sweep Protocol characterizes the changes in viscosity and elasticity due to the alteration of the arrangement, orientation and stretching of the red blood cells in shear.  The viscoelastic profile of normal human blood can be divided into three regions: Low-Shear Region, Mid-Shear Region and High-Shear Region.

       

      rolleux box.jpg (34487 bytes)

      Low-Shear Region

      Here the aggregation tendency of the red cells has its full effect in producing large clusters. As the shear rate increases the shear stress begins to produce some disaggregation and overall reduces the size of aggregates. Cell deformability also affects the character of the aggregates. In this region the character of the aggregates dominates the viscoelasticity.

      Strain 1 box.jpg (36196 bytes)

      Mid-Shear Region

      Cell aggregates are largely destroyed by the stress levels present at these shear rates. Shear flow demands that red cells orient and deform in order to pass adjacent cells. In this region the influence of aggregation on viscoelasticity sharply diminishes and the relative influence of cell deformability begins to increase.

      RBC layer box.jpg (29255 bytes)

      High-Shear Region

      The red cells are strongly aligned to form layers that slide on adjacent plasma layers. The viscoelasticity is strongly influenced by cell deformability because this property limits the ability of the cell to conform to layers. Less deformable cells form thicker cell layers with thinner plasma layers, thus increasing both viscosity and elasticity.


      CRITICAL THREE POINT PROTOCOL

      The Critical Three Point Protocol simplifies the viscoelastic profile using three rapid measurements at fixed strains in the low, mid and high shear region.  By sampling the viscoelastic properties of the blood in each region, simple numberical characterization of the effects of aggregation and dynamic deformability can be used for statistical studies and montiroing progressive hemorheological changes.  These critical measurements are automatically tabulated at the native hematocrit and projected to a hematocrit of 45%, with temperature projections to 25 ?C and 37 ?C.   The ASCII output option exports data from several samples into one file, which is compatible with most spreadsheet programs. 

      Critical Plot.GIF (9678 bytes)


      PLASMA VISCOSITY


      The same precision and reproducibility that makes the BioProfiler ideal for blood viscoelasticity measurements makes it the perfect tool for the measurement of plasma viscosity. With the Vilastic software, quick and simple measurements of plasma viscosity are made, displayed and printed. Viscosity values are provided at the temperature of measurement and automatically projected to 25 ?C and 37 ?C. The ASCII output option exports data from several samples into one file, which is compatible with most spreadsheet programs.

       


    VILASTIC-3 Viscoelasticity Analyzer

    Explore the properties of your bio-fluid by measuring both the viscosity and elasticity over a wide range of values of frequency, shear stress, shear rate and shear strain.

    Rapid sample change with minimal possible contact between the fluid and operator.
    The Vilastic-3 provides the extreme sensitivity and sample handling required for measuring fundamental viscoelastic properties of biological fluids under exquisitely controlled frequency, stress, strain, shear rate, time, and temperature. Once you select a measurement protocol, you can repeat it at any time with high precision because the unvarying geometry of the VILASTIC-3 eliminates the mechanical adjustments and dimensional inaccuracies of traditional rotational instruments. Computer controlled protocols and data processing mean precisely timed measurement sequences, high volume of measurements and disk storage of all results

    Uses water as calibration fluid, a universal standard readily available at no cost

    FEATURES

    • Small sample volume and easy sample handling
    • Fixed tube geometry provides superior reproducibility
    • Resident temperature sensor and clock provide record of thermal conditions and time of measurement
    • Printed data tables together with screen and printer graphics give instantaneous visual presentation of results and hard copy suitable for publication
    • All measurements are subjected to diagnostics for proper instrument operation
    • Each measurement produces 29 parameters for rheological functions, pressure-to-flow relations, energy storage and loss, and thermal conditions
    • ASCII files can be produced for moving selected data into third party spreadsheet and graphics software for further analysis
    TYPICAL BIO-FLUIDS:
    Blood Aqueous suspensions Hyaluronic acid Pharmaceuticals
    Plasma Biopolymers Saliva Plasma proteins
    Synovial Fluid Xanthan Gum Blood and Plasma Clots Dextran solutions
    Mucus Guar Gum Blood volume expanders Semen
    SPECIFICATIONS:
    Shear stress range 0.001 to 1000 dynes/cm2 (0.0001 to 100 Pa) Temperature range 1 to 95 ?C
    Shear rate range 0.1 to 10000/second Frequency range 0.01 to 100 Hertz
    Shear strain range 0.001 to 100 Sample volume 1 ml
    Nominal viscosity 0.005 to 500 Poise (0.0005 to 50 Pa sec) Units selection
    CGS or SI  

    Case size (6" wide by 13 1/2" deep by 11 1/2" high)

    Note: specifications vary with the computer and accessories selected.