Heat transfer enhancement in superheated hydrocarbon fluids due to traces of water

For the specific mode of pulse heating of a wire probe immersed in a test liquid (saturated hydrocarbon), the effect of enhancement of the heat transfer through the probe surface has been revealed. The characteristic heating time is from 10 to 20 ms. The objects of research are n-hexane, n-decane, and n-hexadecane. It is shown that the addition of 0.003% water increases the heat transfer to 10% in the course of approaching the boiling-up temperature of liquid. Simulation of the experimental conditions shows the possibility of microconvection in the most heated boundary layer of a liquid about 10 μm thick.

Validation and optimization of a new instrument for measuring the performances of ultrafiltration membranes

In this study, we introduce the current situation of the membrane inspection industry. We have developed a new integrated rapid membrane inspection machine (MIM) to test the performances of nanofiltration or ultrafiltration membranes by measuring Silt Density Index (SDI) value (i.e., the key performance indicator) of the water filtered. This study optimizes many key conditions include temperature, pH value and pressures, then establishes an SDI detection new method of ultrafiltration membranes by using MIM. We set the temperature of the test liquid to 25 °C, pH in the range of 7–8, and pressure to approximately 0.10 MPa. The results reflect that MIM can be used to effectively determine the SDI of ultrafiltration membranes used the new method and the results of the method validation are satisfactory.

Ist die Expression des GP88-Proteins (Progranulin) ein klinisch relevanter Prognosefaktor für Prostatakarzinompatienten?

ZusammenfassungProgranulin (GP88), ein autokriner Wachstumsfaktor, stellt einen für zahlreiche Tumorentitäten vielversprechenden Biomarker dar. Da sich GP88 sowohl im Tumorgewebe als auch im Serum von Tumorpatienten nachweisen lässt, ist ein minimal-invasiver Test („liquid biopsy“) zum Nachweis von GP88 möglich. Im Prostatakarzinom (PCa) wurde dieser Marker bisher nur in wenigen Voruntersuchungen auf seine diagnostische Aussagekraft hin charakterisiert. In unseren eigenen Arbeiten analysierten wir die Proteinlevel von GP88 im Serum (ELISA-Test) und im Tumorgewebe (Immunhistochemie) in 2 Prostatakarzinompatientenkohorten. Dabei erwies sich der verstärkte Proteinnachweis sowohl im Serum als auch im Tumorgewebe als negativer Prognosefaktor. Interessanterweise traf dies nur auf die jüngeren PCa-Patienten zu. Es sind weitere Untersuchungen erforderlich, um diese Ergebnisse zu bestätigen bzw. eine Eignung von GP88 auch für die Diagnose und das Therapiemonitoring von PCa-Patienten einzuschätzen.

The study of cracking of sheet polycarbonate by the method of exposure to its surface of adsorption active liquid media

The effect of the composition of a liquid mixture of n-propanol with toluene on the rate of cracking in stressed polycarbonate sheets was studied. It is shown that the dependence of cracking time on stress can be described using equations in which the coefficient values depend on the ratio of the components of this test mixture. The method of wetting the surface of a sheet of monolithic polycarbonate with a test adsorption-active mixture (n-propanol with toluene) can be used not only to assess the quality of polycarbonate products, but also to measure the residual stresses in them. The conclusion is made that the influence of the investigated test liquid mixtures on the cracking of polycarbonate is multifactorial.

Research: Comparing ASTM F1671 with a Modified Dot-Blot Method to Evaluate Personal Protective Materials

Effective personal protective equipment (PPE) is critical in preventing the spread of infectious diseases. Appropriate test systems and test soils are needed to adequately evaluate PPE. ASTM test method F903, which specifies the test method setup also used in ASTM F1670 and F1671, has been used for decades to test liquid (ASTM F1670) or viral (ASTM F1671) penetration resistance of PPE fabrics. However, an alteration of the bacteriophage propagation method detailed in the standard was necessary to obtain consistent titers of virus. In this study, modification of the nutrient broth provided consistently higher titers of virus and the use of the top agar in smaller increments prevented premature solidification. This study then compared the standard ASTM F1671 (using bacteriophage φχ174) with a modified dot-blot method to assess viral penetration of PPE materials. The results indicated that ASTM F1671 and the dot-blot apparatus methods were equivalent. The dot-blot method described here is less labor intensive and faster than the ASTM F1671 method. However, using the dot-blot system, which uses antibodies to detect the bacteriophage and signal amplification, does not indicate if virus viability or infectivity is retained, whereas the ASTM F1671 method indicates both. Nonetheless, the method presented in this investigation is a substantial improvement of a standard method for viral challenge testing of PPE materials.

Substantial drag reduction in turbulent flow using liquid-infused surfaces

Experiments are presented that demonstrate how liquid-infused surfaces can reduce turbulent drag significantly in Taylor–Couette flow. The test liquid was water, and the test surface was composed of square microscopic grooves measuring $100~\unicode[STIX]{x03BC}\text{m}$ to $800~\unicode[STIX]{x03BC}\text{m}$, filled with alkane liquids with viscosities from 0.3 to 1.4 times that of water. We achieve drag reduction exceeding 35 %, four times higher than previously reported for liquid-infused surfaces in turbulent flow. The level of drag reduction increased with viscosity ratio, groove width, fluid area fraction and Reynolds number. The optimum groove width was given by $w^{+}\approx 35$.

Quasi Two-Dimensional Evaporation and Boiling Under Reduced Pressure

To study the washing mechanism of laminated plates with solvent vapor, we have experimentally investigated evaporation dynamics of liquid confined between solid plates under reduced pressure. As the test liquid, we use deionized water and several organic compounds. To visualize the fluid motion in the thin gaps, we adopt glass plates. When a test liquid is sandwiched between a normal (float) glass plate and a ground (sand-blasted) one, vertically incident light passes through the plates without much scattering; once the liquid starts to evaporate, dried rough surface of the ground glass scatters the light and we can monitor the flow pattern. Based on the transmitted light intensity, the whole plate area is categorized into three regions; completely wet, completely dry, and semi-dry one; the last one is supposed to be the state that thin liquid film spreads on the plate. In the case of water, many tiny spots of semi-dry region appear and expand at the initial stage, which is probably cavitation of dissolved gas. In organic liquid cases, evaporation seems to start from the edges of the plates. At a later stage, the semi-dry region expands with complicated branching patterns. In all cases, occasional rapid motions of liquid were observed, which correspond to two-dimensional flash boiling. We also investigated the influence of the control pressure, the surface roughness, and the plate deformation.