Earticle

This study evaluates the analytical performance of a newly developed miniaturized disposable U-tube for an automated blood viscometer and compares it to conventional viscometers. Whole blood viscosity (WBV), essential for circulatory function, exhibits non-Newtonian behavior, posing challenges for measurement at low shear rates. The blood viscometer, based on a scanning capillary tube method, used disposable U-tubes to measure viscosities across a shear rate range of 1s⁻¹ to 1,000s⁻¹. Precision evaluation showed stable coefficients of variation (CV) across different viscosity levels. Repeatability assessment indicated consistent CV values, demonstrating the reliability of the device. The agreement with the LV-III Brookfield viscometer and MCR 92 Rheometer was analyzed using Bland-Altman plots, which revealed minor systematic biases and consistent differences across the measurement range. Correlation analysis using Passing-Bablok regression showed high correlation coefficients (R > 0.96) with regression slopes close to 1. The newly developed miniaturized disposable U-tube exhibits excellent precision, reliable repeatability, and high correlation with established methods, enhancing laboratory productivity and offering potential for clinical applications. Further studies with human blood samples are recommended to confirm its clinical applicability.

In this study, we analyzed the The rheological properties of high flowability paste mixing cellulose type viscosity agent. and we suggest that the algorism of a mixing plan in the high flowability concrete and from this, we show the basic report for the right mixing plan. From the results, the yield value and the plastic viscosity is increased in proportion to the added amount of viscosity agent. among the Viscosity Agent, 50us is better than 40us in the plastic viscosity, but is less than in the yield value. this is the fact of the low yield value of the high flowability paste and the flowing Properties with the right Plastic Viscosity. so we concluded that 50us is better than 40us as a viscosity agent of the high flowability concrete.

Objective To compare fluid thickeners composed of starch polysaccharide (STA), guar gum-based polysaccharide (UA), and xanthan gum-based polysaccharide (XAN) with the use of a viscometer and a line spread test (LST) under various measurement conditions.Methods The viscosity of thickened fluid with various concentrations (range, UA 1%-4%, XAN 1%-6%, STA 1%-7%, at intervals of 1%) was measured with a rotational viscometer with various shear rates (1.29 s-1, 5.16 s-1, 51.6 s-1, and 103 s-1) at a temperature of 35°C, representing body temperature. The viscosity of STA showed time dependent alteration. So STA was excluded. Viscosities of UA and XAN (range of concentration, UA 1%-3%, XAN 1%-6%, at intervals of 1%) were measured at a room temperature of 20°C. LST was conducted to compare UA and XAN (concentration, 1.5%, 2.0%, and 3.0%) at temperatures of 20°C and 35°C.Results The viscosities of 1% UA and XAN were similar. However, viscosity differences between UA and XAN were gradually larger as concentration increased. The shear thinning effect, the inverse relationship between the viscosity and the shear rate, was more predominant in XAN than in UA. The results of LST were not substantially different from UA and XAN, in spite of the difference in viscosity. However manufacturers’ instructions do not demonstrate the rheological properties of thickeners.Conclusion The viscosities of thickened fluid were different when the measurement conditions changed. Any single measurement might not be sufficient to determine comparable viscosity with different thickeners. Clinical decision for the use of a specific thickener seems to necessitate cautious consideration of results from a viscometer, LST, and an expert’s opinion.

This study aims to design a real-time system on STM32F4 to measure the density of liquid flow in construction building materials, which can be manually tested in laboratories or construction sites. The study provides an embedded system capable of sequentially and real-time measuring the velocity profile and pressure drop. Existing devices such as rheometers, which are expensive and require calibration, are used to measure fluid flows. However, this study presents a domestically developed device at a lower cost.

The aim of this study was to evaluate the analytical performance of a curved capillary configurations on a U-tube structure used in a tabletop fully automated blood viscometer. Precision was assessed using normal and abnormal quality control materials measured repeatedly over 20 days across shear rates of 1–1000 s⁻1. Correlation between straight and curved capillary configurations was evaluated. Sample stability was also assessed at shear rates of 1 s⁻1 and 300 s⁻1 over three consecutive days. The curved capillary system demonstrated robust precision, with total coefficients of variation decreasing with increasing shear rate. Strong correlations were observed between straight and curved capillary measurements across all shear rates. Passing– Bablok regression showed slopes close to unity and intercepts near zero, while Bland–Altman analysis revealed minimal bias without shear-dependent trends. Whole blood viscosity remained stable over three days at both low and high shear rates (all p > 0.98). The curved capillary–based U-tube configuration provides analytically equivalent and stable whole blood viscosity measurements compared with conventional straight capillary systems, supporting its suitability for fully automated blood viscometer.

혈액의 점도가 높아질수록 혈액은 더 끈적하고 흐름이 어려워지므로 혈전의 발생 가능성이 높아져 허혈성 뇌 경색의 발생 확률이 증가한다. 혈액 점도 측정은 최근 순환기계 질환의 예방을 위하여 그 중요성이 강조되고 있으며 혈액의 점도를 쉽고 정확하게 측정할 수 있는 점도계의 필요성이 대두되고 있다. 본 연구에서는 평행판 점도계 ARS-Medi에 의한 점도표준액과 인공혈액의 측정값들을 국제적으로 정확성과 신뢰성을 인정받는 TA instrument의 Ares-G2로 측정한 값들과 비교하였다.. 뉴턴성 용액인 N44 표준용액의 점도는 모든 전단율에서 두 기기 간에 거의 완벽하게 일치하였다, 비뉴턴성 용액인 인공혈액의 경우 가장 낮은 전단율인 1 rad/s 에서는 약 10%의 차이를 보였 으나, 임상적으로 유의한 전단율인 10 rad/s 이상에서는 두 기기간의 측정값이 오차범위 내에서 모두 일치하였다. 우 리는 새로 개발한 혈액 전용 평행판형 점도계 ARS-Medi가 1회용 평행판을 사용하므로 혈액 점도 측정의 편의성과 위생성이 향상되어 임상에 매우 유용할 것으로 기대한다.

As the viscosity of the blood increases, the blood becomes more sticky and difficult to flow, so the possibility of thrombosis increases and the probability of ischemic cerebral infarction increases. The importance of measuring blood viscosity has recently been emphasized for the prevention of circulatory system diseases, and the need for a viscometer capable of easily and accurately measuring blood viscosity has emerged. In this study, the measured values of a viscosity standard solution and an artificial blood by a parallel-plate viscometer ARS-Medi were compared with the those by Ares-G2 of TA instrument, which is internationally recognized for its accuracy and reliability. The viscosity of N44 standard solution, which is a Newtonian solution, was almost perfectly matched between the two instruments at all shear rates. In the case of an artificial blood, which is a non-Newtonian solution, the measured values between the two instruments showed a difference of about 10% at the lowest shear rate 1 rad/s; however, at a clinically significant shear rate of 10 rad/s or higher, the measured values between them were consistent within the error range. We expect that ARS-Medi, a newly developed parallel-plate viscometer for blood, using disposable plates, will be very useful in clinical practice as it improves the convenience and hygiene of blood viscosity measurement.

Rheological property and apparent viscosity(η)of several semi-solid foods were measured with extrusion capillary viscometer. Apparent viscosities of several semi-solid foods ranged from 0.2714 Pa.s to 2.6453 Pa.s Rheological property of spread type semi-solid foods was pseudoplastic (with yield value). Especially, as the moisture content and temperature of Chungkook-jang spread increased, apparent viscosity decreased. On the contrary, as the added soybean oil content of Chungkook-jang spread increased, apparent viscosity also increased.

In order to compare the diagnosis values the Rolling Ball Viscometer(RBV) and the California Mastitis Test(CMT) for detection of bovine subclinical mastitis, A total of 2204 quarter milk samples from 565 heads of Holstein in Gyeongnam area were examined d

This study introduces a new approach to a falling ball viscometer by using a high speed motion camera to measure the viscosity of both Newtonian and non-Newtonian fluids from the velocity-time data. This method involves capturing continuous photographs of the entire falling motion of the ball as the ball accelerates from the rest to the terminal velocity state. The velocity of a falling ball was determined from the distance traversed by the ball by examining video tape frame by frame using the marked graduations on the surface of the cylinder. Each frame was pre-set at 0.01. Glycerin 74% was used for Newtonian solution, while aqueous solutions of Polyacrylamide and Carboxymethyl Cellulose were for non-Newtonian solutions. The experimental viscosity data were in good agreements with the results obtained from a rotating Brookfield viscometer.

A newly designed pressure-scanning slit viscometer is developed to combine an optical device without refraction while measuring blood viscosity over a range of shear rates. The capillary tube in a previously designed capillary viscometer was replaced with a transparent slit, which is affordable to mount optical measurement of flowing blood cells. Using a pressure transducer, we measured the change of pressure in a collecting chamber with respect to the time, p(t), from which the viscosity and shear rate were mathematically calculated. For water, standard oil and whole blood, excellent agreement was found between the results from the pressure-scanning slit viscometer and those from a commercially available rotating viscometer. This new viscometer overcomes the drawbacks of the previously designed capillary viscometer in the measuring whole blood viscosity. First, the pressure-scanning slit viscometer can combine an optical instrument such as a microscope. Second, this design is low cost and simple (i.e., ease of operation, no moving parts, and disposable).

Viscosity index improver (VII) is one of the major additives to the modern multigrade lubricants for the viscosity stability against temperature rise. However, it causes shear thinning effects which make the film thickness lessened very delicately at high shear rate $(over\;10^5\;s^{-1})$ of general EHL contact regime. In order to exactly verify the VII's performance of viscosity stability at such high shear rate, it is necessary to make the measurement of EHL film thickness down to $\~100nm$ with fine resolution for the preliminary study of viscosity control. In this work, EHL film thickness of VII added lubricant is measured with the resolution of $\~5nm$, which will give very informative design tool for the synthesis of lubricants regarding the matter of load carrying capacity at high shear rate condition.

Accurate interpretation of whole-blood viscosity (WBV) requires population-specific refer- ence intervals (RIs), as WBV is influenced by sex, age, and Hct. This study is the first to es- tablish RIs for WBV using a fully automated scanning capillary tube viscometer, RHEOVIS 200 (Biorheologics, Jeonju, Republic of Korea), in Korean adults. WBV was measured in 438 adults at shear rates of 1 s?1 (diastolic WBV) and 300 s?1 (systolic WBV). RIs were de- termined using the non-parametric method according to CLSI guideline EP28-A3c, and median WBV values were compared by sex and age. At 1 s?1, the RIs were 20.83?38.50 millipascal-second (mPa·s) in all adults, 25.97?39.26 mPa·s in men, and 20.14?35.08 mPa·s in women. At 300 s?1, these were 3.74?5.50 mPa·s in all adults, 4.16?5.60 mPa·s in men, and 3.64?5.05 mPa·s in women. The median WBV was significantly higher in men than in women (P <0.01) and lower in the 20?30-yr group than in other groups (P ≤0.03). Sex-specific RIs are required for accurate WBV interpretation in Korean adults, and age- specific RIs require further validation. For WBV measurements using RHEOVIS 200, clini- cal laboratories should establish and continually verify their own RIs.

Elastohydrodynamic lubrication (EHL) film is measured under the condition of viscosity index improver added to base oil. In-situ optical contact method using the interference principle make the measuring resolution of ~5 nm possible and enables the measuring range all over the contact area of up to ~300 $\mu\textrm{m}$ diameter. What is more important to the developed method by the author is that the measurement of EHL film thickness is possible in the range from 100 nm to 2 $\mu\textrm{m}$, which is the regime of worst contact failures in precision machinery. Viscosity index improver (VII) is one of the major additives to the modem multigrade lubricants for the viscosity stability against temperature rise. However, it causes shear thinning effects which make the film thickness lessened very delicately at high shear rate (over $10^5 s^{-1}$) of general EHL contact regime. In order to exactly verify the VIIs performance of viscosity stability at such high shear rate, it is necessary to make the measurement of EHL film thickness down to ~100 nm with fine resolution for the preliminary study of viscosity control. In this work, EHL film thickness of VII added lubricant is measured with the resolution of ~5 nm, which will give very informative design tool for the synthesis of lubricants regarding the matter of load carrying capacity at high shear rate condition.

레이저와 타이머장치를 설치한 낙구식 점도계에서 구와 니들이 주어진 구간을 통과 하는 시간을 측정하여 종말속도를 정확히 결정하였고 점성이 작은유체와 낮은 전단률 점성 과 영전단률 점성은 속이 빈 알루미늄 구와 니들이 이용하여 측정하였다. 알루미늄 구와 니 들의 속에 철분을 삽입하여 밀도를 다양하게 변화시켰다. 낙구식 점도계에서 측정한 낮은 전단률 점성과 영 전단률 점성 그리고 모세관점도계에서 측정한 높은전단률 점성과 무한 전 단률 점성을 이용하여 점탄성 유체의 특성이완시간을 결정하였다. 실린더 속의 시험용 유체 를 교란시키지 않고 밑면에 떨어진 구를 회수하는 장치를 설치하였다. 이 장치는 하나의 구 로써 점탄성유체의 특성확산시간을 측정하는데 대단히 효과적이었다. Polyacrylamide Separan AP-273 용액(농도 500-200 wppm)의 특성이안시간과 특성화산시간을 낙구식 점도 계와 모세관 점도계의 실험결과를 이용하여 결정하고 폴리며 용액의 퇴화 현상을 실험적으 로 분석하였다.

The objective of the present study were to measure the viscosities of non-Newtonian fluids by the transient flow concept in a capillary tube and to apply to hemodynamic studies and pump performance evaluations. The developed capillary tube viscometer could be used to measure the viscosities of the non-Newtonian fluids for a wide range of the shear rate by a run of experiment in a very short time interval. The measured viscosities of water and blood fur different shear rates were good agreement with those of the well established data. The measured viscosities for muddy water varied with the shear rates.

The objective of the present study is to develop a new device that the viscous characteristics of fluids are determined by applying the unsteady flow concept to the traditional capillary tube viscometer. The capillary tube viscometer consists of a small cylindrical reservoir, capillary tube, a load celt system oat measures the mass flow rate, interfacers, and computer. Due to the small size of the reservoir the height of liquid in the reservoir decreases as soon as the liquid in the reservoir drains out through the capillary and the mass flow rate in the capillary decreases as the hydrostatic pressure in the reservoir decreases resulting in a decrease of the shear rate in the capillary tube. The instantaneous shear rate and. driving force in the capillary tube are determined by measuring the mass flow rate through the capillary, and the fluid viscosity is determined from the measured flow rate and the driving force.

배경: 전혈 점도는 혈액이 혈관을 통과할 때 발생하는 내부 저항을 의미한다. 이러한 전혈 점도는 기존의 연구를 통해 심혈관 및 뇌혈관질환을 비롯한 많은 질병과 관련이 있는 것으로 밝혀졌다. 본연구에서는 전혈 점도 측정을 위해 새로 개발된 미세유체역학 혈액점도계 Viscore-300 (NanoBiz, Korea)의 분석적 성능 평가와 참고범위를 설정하였다. 방법: 세 가지 정도관리물질을 사용하여 20일 동안 240번의 측정을 통하여 정밀도 평가를 수행하였다. 재현성 평가를 위해 3개의전혈 검체를 하루 동안 60번 측정하였다. 또한 정확도 평가를 위해CLSI 가이드라인에 따라 100개의 전혈 검체를 이용하여 회전식 점도계 DV3T (Brookeld, USA)와 비교하였다. 전혈 점도의 참고범위를 122명의 건강인을 대상으로 설정하였다. 결과: 정밀도 및 재현성 평가 결과 세 가지 물질과 두 전단율 모두에서 5% 미만의 변이 계수를 보였다. 정확도 평가 결과, 평가장비와비교장비의 평균 차이는 10 s–1과 300 s–1의 전단율에서 각각 0.09 cP 및 –0.07 cP이었다. 전혈 점도의 참고범위는 남자에서 저전단율10 s–1하에서 6.88–13.52 cP, 고전단율 300 s–1하에서 4.32–6.43 cP로측정되었다. 여자에서는 저전단율 10 s–1하에서 5.74–13.29 cP, 고전단율 300 s–1하에서 3.60–6.12 cP로 측정되었다. 결론: Viscore-300은 기존 회전식 점도계 DV3T와 비교했을 때 정밀도가 우수하였고, 정확한 점도 측정 결과를 보였다. 따라서 본연구에서 평가한 새로운 혈액점도계는 임상검사실에서 임상 진료과의 요구에 맞춰 정확하고 신속하게 전혈 점도를 보고할 수 있을것으로 판단되었다.

Background: Whole blood viscosity (WBV) refers to the internal resistance that occurs when blood flows through blood vessels. WBV is known to be related to many diseases including cardiovascular and neurovascular diseases. We have investigated the analytical performance and established reference intervals for a newly developed microfluidic viscometer, Viscore-300 (NanoBiz, Korea), used for the measurement of WBV. Methods: We performed a precision test of 240 measurements over 20 days using three control materials. For evaluation of repeatability, a total of 60 WBV measurements were made in 3 whole blood samples 20 times a day. A total of 100 whole blood samples were used to evaluate the accuracy of the Viscore-300 in comparison to a rotating viscometer, DV3T (Brookfield, USA), in accordance with the the Clinical and Laboratory Standards Institute’s guidelines. To establish the reference intervals, 122 healthy individuals were enrolled in this study. Results: The precision and repeatability results showed that the CV was less than 5% for three samples and two shear rates. In the accuracy test, the mean differences between two viscometers were 0.09 cP (0.9%) and ?0.07 cP (?1.4%) at shear rates of 10 s?1 and 300 s?1, respectively. The reference intervals of WBV for men were 6.88?13.52 cP at 10 s?1 and 4.32?6.43 cP at 300 s?1; those of women were 5.74?13.29 cP at 10 s?1 and 3.60?6.12 cP at 300 s?1. Conclusions: Viscore-300 showed excellent precision and accuracy and it might be a good instrument for reporting WBV quickly and accurately.

Electro-Rheological(ER) fluids change their apparent viscosity according to the electric field strength. Therefore, there are many practical applications using the ER fluids. ER effect on the dispersive system of polarizable fine powder/dielectric oil has been investigated. The electrical and rheological properties of starch based ER fluid were reported. Yield stress of the fluids were measured on the couette cell type rheometer as a function of electric fields, particle concetrations, and temperatures. The electric field is applied by high voltage DC power supply, The outer cup is connected to positive electrode(+) and the bob becomes ground(-). And the temperatures the viscosity(or shear stress) versus shear rates were measured. In this experiment shear rates were increased from 0 to 200s$^{-1}$ in 2 minutes. This thesis presents Bingham properties of ER fluids subjected to temperature variations. The temperature dependence of the viscosity was determined for ER fluids consisting of 35 weight % starch particles in automatic transmission oil.