COMMENTS ON THE DETERMINATION OF FRIABILITY AND UNMODIFIED GRAINS

The Analysis Committee of the European Brewery Convention is aware that the Friabilimeter sometimes is used on samples that do not comply with the field of application. The precision of the method is also overlooked by some users. The field of application, precision of the method as well as the need for frequent testing of the instrument is therefore stressed in more detail than in the earlier published method by the EBC Analysis Committee.     

Canadian hydrogen safety program

The Canadian hydrogen safety program (CHSP) is a project initiative of the Codes & Standards Working Group of the Canadian transportation fuel cell alliance (CTFCA) that represents industry, academia, government, and regulators. The Program rationale, structure and contents contribute to acceptance of the products, services and systems of the Canadian Hydrogen Industry into the Canadian hydrogen stakeholder community. It facilitates trade through fair insurance policies and rates, effective and efficient regulatory approval procedures and accommodation of the interests of the general public. The Program integrates a consistent quantitative risk assessment methodology with experimental (destructive and non-destructive) failure rates and consequence-of-release data for key hydrogen components and systems into risk assessment of commercial application scenarios. Its current and past six projects include Intelligent Virtual Hydrogen Filling Station (IVHFS), Hydrogen clearance distances, comparative quantitative risk comparison of hydrogen and compressed natural gas (CNG) refuelling options; computational fluid dynamics (CFD) modeling validation, calibration and enhancement; enhancement of frequency and probability analysis, and Consequence analysis of key component failures of hydrogen systems; and fuel cell oxidant outlet hydrogen sensor project. The Program projects are tightly linked with the content of the International Energy Agency (IEA) Task 19 Hydrogen Safety.     

C_2对称茂金属配合物催化丙烯均聚及丙烯与高级α-烯烃共聚

研究了C2对称的[Me2Si(2-Me-4-Ph-Ind)2]Zr Cl2双茂锆催化剂在不同条件下对丙烯均聚及丙烯与高级α-烯烃共聚反应的催化特性。研究结果表明:配合物的催化活性随着铝锆比、温度、压力的增加而提高;聚合物数均相对分子质量随着温度的提高而降低,在25℃、1 MPa丙烯压力下,可以获得数均相对分子质量高达40万的等规聚丙烯。该催化体系具有良好的共聚活性,共单体的侧链长度并不影响聚合活性。通过改变共单体的投料比,可控制共聚物中共单体的含量。     

Blood and tissue distribution of gamma glutamyl transferase in calves.

In five male and five female calves, we studied the tissue distribution of gamma-glutamyl transferase. The enzyme was mainly in kidney, pancreas, and liver; there was no sex-related difference. The relative hepatic and pancreatic specificity of the enzyme indicated that the measure of its activity in serum could be a test of hepatic or pancreatic damage in the calf. Serum activity measured within 159 samples of apparently healthy calves was 15.3 +/- 3.7 U/liter, not differing significantly from that of adult cow.     

Experimental comparison of latent and sensible heat thermal walls

Three thermal walls have been examined with the same test-cell. The complete experiment, for the three walls, lasted 3 yr. The test-cell was thoroughly instrumented to permit the energy balance on the various parts of the cell (thermal wall, inner room, front glazing) to be checked against real data. Moreover the dynamical loading of the test-cell was varied to simulate various couplings between the wall and the enclosure. This simulation was made with the help of two flat plate air-air heat exchangers covering totally the top and opposite inside walls of the cell. The simulation allowed the performance of thermal walls coupled to a back room to be assessed.

The energy yield of the walls and the temperature variations of the inside room are compared for a 40 cm thick concrete wall, an 8 cm thick hard paraffin wall, and an 8 cm thick soft paraffin wall. The advantage of the paraffin walls over the concrete is a mass, -including containers, one-twelfth smaller, thus much better suited to a retrofit.     

Use of a variable parameter test-cell for the study of latent-heat solar walls

A paraffin Trombe wall with double glazing, is studied experimentally with the help of a test-cell allowing several working conditions to be checked. The efficiency of the wall itself is shown to be very similar whether thermocirculation is on or not. But an important additional contribution comes from the glazing in the first case. The analysis of the results points out that a controlled air circulation would give much better results than the two cases considered. Indeed the overheating due to thermocirculation can be cancelled by some controlled air circulation only, and the important convective front losses observed at the begining of the night have to be decreased by getting the heat back to the room through forced air circulation.     

Tip‐vortex breakdown of wind turbines subject to shear

Sheared velocity profiles pervade all wind‐turbine applications, thus making it important to understand their effect on the wake. In this study, a single wind turbine is modeled using the actuator‐line method in the incompressible Navier–Stokes equations. The tip vortices are perturbed harmonically, and the growth rate of the response is evaluated under uniform inflow and a linear velocity profile. Whereas previous investigations of this kind were conducted in the rotating frame of reference, this study evaluates the excitation response in the fixed frame of reference, thus necessitating a frequency transformation. It is shown that increasing the shear decreases the spatial growth rate in the upper half of the wake while increasing it in the lower half. When scaled with the local tip vortex parameters, the growth rate along the entire azimuth collapses to a single value for the investigated wavenumbers. We conclude that even though the tip‐vortex breakdown is asymmetric in sheared flow, the scaled growth rates follow the behavior of axisymmetric helical vortices. An excitation amplitude reduction by an order of magnitude extends the linear growth region of the wake by one radius for uniform inflow. In the sheared setup, the linear growth region is extended further in the top half than in the bottom half because of the progressive distortion of the helical tip vortices. An existing model to determine the stable wake length was shown to be in close agreement with the observed numerical results when adjusted for shear.     

Analysis of volatile compounds in L. edodes blanched by hot water and microwave

The comprehensive flavour characterisation and volatile compounds of raw L. edodes, hot water blanching (HB) sample and microwave blanching (MB) sample were comparatively analysed by electronic nose technology and headspace solid‐phase micro‐extraction combined with gas chromatography‐mass spectrometry (HS‐SPME‐GC‐MS). Results indicated that volatile components in L. edodes markedly changed after HB and MB. Volatile compounds of raw L. edodes consisted mainly ketones, sulphide and alcohols, and 3‐octanone, as well as 1‐octen‐3‐one, were the major compounds. The content of ketones and sulphides in blanched samples markedly decreased, while the relative content of aldehydes, hydrocarbons and esters increased, which became the major volatile compounds of treatment samples. In addition, the percentage contents of esters, alcohols and sulphides in MB samples were significantly (P < 0.05) higher than that in HB samples, especially 1‐octen‐3‐ol, which contributes more to mushroom flavour. Therefore, MB is a better pretreatment method of L. edodes processing and cooking according to the results of experiment.     

Condenser performance in a cylindrical humidification and dehumidification (HDH) system

In recent years, humidification and dehumidification (HDH) systems have garnered significant attention due to their enhanced effectiveness with packed beds, particularly for high-salinity waters. The direct-contact packed beds HDH system offers a more convenient and efficient installation compared with conventional HDH systems. This paper introduces a novel, compact cylindrical crossflow HDH system design that is easily constructed and scalable for industrial and residential applications. The compact crossflow-packed bed condenser employs perforated air tubes to distribute humidified air radially while cooling water drips vertically through the packed bed, coming into direct contact with the humidified air. To evaluate the system's performance, two-dimensional steady-state energy, and mass conservation equations were developed solving enthalpies instead of temperatures as dependents. The coupled partial differential equations were numerically solved to predict water temperature, air/vapor temperature, humidity ratio, and condenser effectiveness. Multiple designs were proposed, demonstrating that the proposed configuration can achieve effectiveness above 0.80 and a water production rate of 3.85 g/s under ideal operating conditions.