Comparison of hazes in freshly bottled and aged beers by multiple angle turbidimetry

The hazes of freshly bottled and aged pale lager beers determined with the 12° and 90° dual angle laboratory hazemeters and 10° to 90° range photogoniometer were compared and evaluated. The instruments were standardised in EBC formazin units. In freshly bottled beer, the forward (12°–25°) haze values were smaller approximately by a factor of three than the nephelometric (90°) values which yielded 0.33 EBC units. In aged beer, the forward haze was greater than the nephelometric one. Whereas the aged beer showed the greatest and the fresh beer the lowest intensity of scattered light, the formazin suspension intensity was in between. Due to the standardisation of the beer scattered intensities by relation to that of formazin, the standardised nephelometric haze in non-aged beer was greater than the forward haze, and vice versa in aged beer. The greater forward than the nephelometric haze in aged beer was caused by the growth of haze particles above the mean size of formazin particles which was larger than 2 μm as confirmed by the particle size distribution measurement.

Download Full-text

Batch Precipitation of Lead Iodide

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19941301 ◽

1994 ◽

Vol 59 (6) ◽

pp. 1301-1304

Author(s):

Jaroslav Nývlt ◽

Stanislav Žáček

Keyword(s):

Aqueous Solution ◽

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Crystal Size ◽

Lead Nitrate ◽

Lead Iodide ◽

Constant Rate ◽

Mean Size ◽

The Mean

Lead iodide was precipitated by a procedure in which an aqueous solution of potassium iodide at a concentration of 0.03, 0.10 or 0.20 mol l-1 was stirred while an aqueous solution of lead nitrate at one-half concentration was added at a constant rate. The mean size of the PbI2 crystals was determined by evaluating the particle size distribution, which was measured sedimentometrically. The dependence of the mean crystal size on the duration of the experiment exhibited a minimum for any of the concentrations applied. The reason for this is discussed.

Download Full-text

Application of artificial bee colony algorithm for particle size distribution measurement of suspended sediment based on focused ultrasonic sensor

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331221989115 ◽

2021 ◽

pp. 014233122198911

Author(s):

Yeming Li ◽

Yidan Xia ◽

Dailiang Xie ◽

Ya Xu ◽

Zhipeng Xu ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Suspended Sediment ◽

Artificial Bee Colony ◽

Ultrasonic Sensor ◽

Inversion Algorithm ◽

Distribution Measurement ◽

Bee Colony ◽

Particle Size Distribution Measurement

A new focused ultrasonic sensor is proposed, based on which the measurement system for particle size distribution measurement of suspended sediment is established. Compared with the traditional ultrasonic sensors, the one used in this paper is equipped with piezoelectric transducer (PZT) on an arc-shaped shell, to concentrate ultrasonic beams on one measurement point. The sensor is used to measure the particle size distribution of suspended sediment. The experiments were carried out on water-sediment mixtures with different particle size distribution. Due to multiple parameters and non-linearity of the ultrasonic attenuation model, the artificial bee colony (ABC) inversion algorithm is used to estimate particle size distribution, thus improving measurement accuracy. The particle sizes obtained by sieving method are seen as reference values. The results indicate that whether the suspended particles are subject to a unimodal distribution, uniform distribution or random distribution, the particle size distribution obtained by ABC inversion algorithm is consistent with the result obtained by the sieve method. The results demonstrate that the method has good utility and accuracy within the low concentration range.

Download Full-text