In order to obtain a better understanding of the non-ideal detonation behaviour of ammonium nitrate based explosives, detonation velocities of ANFO (ammonium nitrate and fuel oil) prepared with different kinds of ammonium nitrate (AN) were measured in steel tubes. In this series of test six kinds of AN were used and the influence of the pore diameter, the pore volume and the particle diameter of the AN particle on the detonation velocity of ANFO was investigated.
It was found that the pore diameter and the pore volume had a strong influence on the detonation velocities of ANFO. In the case of ANFO samples which were prepared with AN that had the same pore diameter and the pore volume, when tested the highest detonation velocity (3.85 km/s) was observed when the smallest particle diameter (<0.85 mm) was used. This value corresponded to 75% of the ideal detonation velocity, which was theoretically predicted by the CHEETAH code with the JCZ3-EOS.
The 12 months aging showed the change of the detonation velocities of ANFO and the reaction of ANFO was influenced both by the physical and the chemical properties of AN particles and oil during the storage period. 相似文献
Soybean protein is a potential material for manufacturing of biodegradable plastics. The objective of this investigation was to characterize the thermal and mechanical properties of plastics made from sodium dodecyl sulfate (SDS)-modified soy proteins. Soy protein isolate (SPI) was prepared from defatted soy flour, modified with various concentrations of SDS, and then molded into plastics. The temperatures of denaturation of the modified soy protein increased at low SDS concentration and then decreased at high SDS concentration. At the same SDS concentration, the plastics molded from the modified soy proteins showed a similar temperature of denaturation, but a lower enthalpy of denaturation compared to the modified soy protein. Young's modulus of the plastics decreased as SDS concentration increased, and the tensile strength and strain at break of the plastics reached a maximum value at 1% SDS modification. Two glass transition temperatures were identified corresponding to the 7S and 11S globulins in SPI by dynamic mechanical analysis, and they decreased as SDS concentration increased. The SDS modification increased the water absorption of the plastics. 相似文献
The crucial parameter used to calculate turbulence effects upon light waves propagating through the atmosphere is known as
the structure constant, . As Tatarski has shown, this parameter depends upon the “outer scale” of the inertial sub-range of the turbulence. Recently
there have been successful predictions of astronomical “seeing” conditions at Mauna Kea Astronomical Observatory which have
increased interest in this subject and in the use of the so-called “Dewan Optical Turbulence Model”. In the case of the Air
Force, there has been a longstanding need for such optical turbulence prediction, especially in the stratosphere. In the past
researchers have used a relation due to Tatarski, (which plays a prominent role in this model) in order to deduce values of
the “outer scale” from measurements. When doing this, they have been surprised to find values very much smaller than expected. The goal of the paper
is to explain this unexpected result. As we will show, this result can be explained by two factors: (a) the average turbulent
layer thicknesses are smaller than originally believed, and, more importantly, (b) only a minor fraction of the stratosphere
is turbulent. In order to arrive at this conclusion, we used the high-resolution (10 m) wind profiles that were originally
used to formulate the previously mentioned optical turbulence model.
The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged. 相似文献
‘Metal ash’ presents a waste disposal problem in most of the developing countries as the industries employ obsolete technologies.
In this paper we describe analysis of tin ash, zinc ash and aluminium ash by means of optical methods, such as X-ray diffraction
(XRD), inductively coupled plasma mass spectrometry (ICP-MS), electron probe micro analysis (EPMA), scanning electron microscopy
(SEM) and chemical methods. The results of tin ash obtained by XRD method matched well with the cassiterite, a naturally occurring
mineral of tin. ICP-MS studies reveal the presence of a large number of tracer metals, which may cause pollution by tertiary
dispersion and this aspect is discussed. Conversely, the data generated by chemical methods are limited. However, the methods
are simple and cost-effective. Then, they can easily be adopted by low-budget industries. Simple and cost-effective process
to recover tin from tin ash is described. It is based on heating tin ash with sodium cyanide to about 900°C to separate tin
component from the metal ash. The process recovers good quality tin and offers a very high yield. The process can be scaled
up to small pilot plant. 相似文献