Change of evaporation rate of single monocomponent droplet with temperature using time-resolved phase rainbow refractometry

Droplet evaporation characterization, although of great significance, is still challenging. The recently developed phase rainbow refractometry (PRR) is proposed as an approach to measuring the droplet temperature, size as well as evaporation rate simultaneously, and is applied to a single flowing n-heptane droplet produced by a droplet-on-demand generator. The changes of droplet temperature and evaporation rate after a transient spark heating are reflected in the time-resolved PRR image. Results show that droplet evaporation rate increases with temperature, from ?1.28$\times {10}^{?8}$ m²/s at atmospheric 293 K to a range of (?1.5, ?8)$\times {10}^{?8}$ m²/s when heated to (294, 315) K, agreeing well with the Maxwell and Stefan–Fuchs model predictions. Uncertainty analysis suggests that the main source is the indeterminate gradient inside droplet, resulting in an underestimation of droplet temperature and evaporation rate. With the demonstration on simultaneous measurements of droplet refractive index as well as droplet transient and local evaporation rate in this work, PRR is a promising tool to investigate single droplet evaporation in real engine conditions.     

折光计法测定酱油中可溶性无盐固形物的含量

基于可溶性固形物的折射原理，用折光计法测定酱油中可溶性无盐固形物的含量，取得了与重量法基本一致的结果。该方法不需要对样品进行预处理，操作简便、快速，10—20s即可测定1份样品。     

苯-氯苯二元系的折射分析

研究了液体二元系的折射分析法。发现苯-氯苯的折射率和组成间有良好的线性关系。得出了线性方程。利用方程测得的结果和实际值十分吻合。     

Differential refractometry of molecular complexes: A reinvestigation

A modified plot method is used to calculate equilibrium constants of molecular complexes. This method (Sahai andSingh's plot) is compared with the method ofYoshida andOsawa.

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Differentielle Refraktometrie von Molekülkomplexen: Eine Neuuntersuchung (Kurze Mitteilung)

Zusammenfassung Eine modifizierte refraktometrische Methode zur Berechnung von Gleichgewichtskonstanten von Molekülkomplexen wird verwendet und diese mit der Methode vonYoshida undOsawa verglichen.

     

两组分糖快速测定中计算方法的研究

利用糖的旋光和折光性分别测定两种糖，方法简捷，所需时间仅几分钟。利用作推导的定量关系方程，并由此设计的计算用列线图，可使计算工作在１０ｓ内完成。     

A device for measuring the velocity of ultrasonic waves: An application to stress analysis

In this paper we present a device for the practical application of an ultrasonic critical-angle refractometry (UCRfr) technique. UCRfr is a technique for measuring the velocity of longitudinal, shear and Rayleight waves, developed to improve the traditional ultrasonic methods for measuring the stress level in materials by means of acousto-elasticity. The technique consists of relating the variations in wave propagation velocity to variations in the angle of refraction at the interface with a second medium. Variations in the angle of refraction are determined on the basis of delay in receiving of the same wave at two different points. The study deals with the measurements of velocity changes of longitudinal wave due to uniaxial stress. In the present work the effects of stress on aluminum and steel specimens have been studied. Experimentation has show the potential of the technique for stress measurement; on the other hand, when the applied stress is known, it allows the measurement of the acoustoelastic constants of longitudinal waves. As regards measuring variations in velocity induced by stress, using this method it is possible, with a suitable choice of the material the device is made of, to isolate the effects of stress on velocity from the possible effects of temperature.     

Studies of Image Processing and Refractive Index in Blue Phase

The isotropic - blue phases - cholesteric phase transitions are studied in a thermotropic (COC) by image processing and refractive index measurements. Textures of blue phases are optically characterized as well as their transition points. The experimental investigation employed here is sensitive to detect changes in the structural configuration of blue phases as a consequence of our refractive index data. In this context the experimental results are presented and discussed.     

The rapid quantitative determination of aromatic-type groups in gas oils by high-performance liquid chromatography

Summary A rapid method is described for the quantitative determination of aromatic-type groups in gas oil petroleum fractions. The method involves separation by high-performance liquid chromatography followed by detection with a differential refractometer, whose response to aromatic-type groups is more predictable than an ultra violet absorbance detector. A primary standard is used for calibration, and the precision and accuracy of the method have been investigated and are discussed.