Thermal Kinetic Parameters of Lead Azide and Lead Styphnate with Antistatic Additives

2015 ◽  
Vol 41 (2) ◽  
pp. 267-272 ◽  
Author(s):  
Jianchao Liu ◽  
Yutong Jiang ◽  
Wenchao Tong ◽  
Tonglai Zhang ◽  
Li Yang
Keyword(s):  
Kinetic Parameters ◽  
Lead Azide ◽  
Thermal Kinetic Parameters ◽  
Antistatic Additives ◽  
Lead Styphnate

Ignition characteristics of semiconductor bridge based on lead styphnate and lead azide charges under capacitor discharge conditions

2016 ◽  
Vol 241 ◽  
pp. 27-33 ◽  
Author(s):  
Hanjian Li ◽  
Qing Zhou ◽  
Hui Ren ◽  
Qingjie Jiao ◽  
Shujing Du ◽  
...  
Keyword(s):  
Lead Azide ◽  
Capacitor Discharge ◽  
Ignition Characteristics ◽  
Lead Styphnate

Note. Kinetic parameters of Bacillus stearothermophilus spores under isothermal and non-isothermal heating conditions Nota. Parámetros cinéticos del tratamiento isotérmico y no isotérmico de esporas de Bacillus stearothermophilus

1998 ◽  
Vol 4 (6) ◽  
pp. 443-447 ◽  
Author(s):  
P.M. Periago ◽  
S. Leontidis ◽  
P.S. Fernández ◽  
C. Rodrigo ◽  
A. Martínez
Keyword(s):  
Kinetic Parameters ◽  
Nonlinear Regression ◽  
Bacillus Stearothermophilus ◽  
Confidence Regions ◽  
Regression Method ◽  
Isothermal Heating ◽  
One Step ◽  
Nonlinear Regression Method ◽  
Thermal Kinetic Parameters ◽  
The One

Thermobacteriological studies using Bacillus stearotherrnophilus spores were carried out by heating the spores under isothermal and non-isothermal conditions followed by an isothermal period. Ex perimental data obtained after isothermal heating were analyzed using a two-step linear regression procedure and a one-step nonlinear regression method. Results obtained using both analytical tech niques were close, but the 90% interval of confidence for predictions was lower when the one-step nonlinear regression was used. These results indicated the convenience of using the one-step nonlin ear regression method to obtain thermal kinetic parameters for bacterial spores. Also, the parameters obtained by a non-isothermal program followed by an isothermal heating period were similar to those obtained after isothermal heating. Nevertheless, the joint confidence regions at 90% did not overlap, indicating that there are significant differences. The z values obtained under isothermal (7.0 °C) and non-isothermal (8.5 °C) conditions are close and characteristic for this microorganisms.

scholarly journals The sensitiveness of explosives - Delay to ignition and its temperature coefficient

1948 ◽  
Vol 241 (831) ◽  
pp. 204-222 ◽  
Keyword(s):  
Activation Energy ◽  
Induction Period ◽  
Absolute Temperature ◽  
Lead Azide ◽  
Predominant Role ◽  
Mixed Composition ◽  
X Ray ◽  
Physico Chemical ◽  
The Difference ◽  
Lead Styphnate

In § ( a ), details are given of a method of determining the delay to ignition at various temperatures, for initiators. The heat sensitiveness of an initiator can be characterized by an equation log F = £ /4 -5 7 r + 5 , where Y is the induction period before ignition, E is the activation energy of the physico-chemical process controlling it, in kcal./mol., and B is a constant. T is the absolute temperature. Values of E and B are listed for lead azide, mercury fulminate, basic lead di-nitroresorcinate (L. D. N. R.), lead styphnate and barium styphnate. From an extrapolation, ignition temperatures have been calculated corresponding with delays of 10<super>~3</super> and 10<super>~5</super> sec., to link these up with certain aspects of sensitiveness and detonation. Experiments are described which show that initiators such as lead azide can be more or less permanently sensitized by heat treatment, and by photochemical action. In § ( b ), experiments are described on the failure to detonate below a certain temperature, and on the ignition times, of lead azide, lead styphnate and mercury fulminate. The behaviour of mixed initiators, and of simple initiators admixed with inert diluents, has also been investigated. The results show that detonation is built up from the co-operation of a number of centres of reactivity. It is shown that in the mixed composition ‘ A.S.A.’ the lead styphnate plays the predominant role in the heat sensitiveness, improving the thermal pick-up and lessening the tendency of lead azide to fail to detonate on heating. In § ( c ), X-ray measurements and determinations of the heat sensitiveness are described for Service and dextrin azides. It is shown that the grains of Service azide consist largely of single crystals, whereas the grains of dextrinated azide each contain about 10<super>6</super> crystallites. The lattice crystal structure in the two azides is the same. With the samples investigated, the activation energy controlling the length of the induction period is about 41.3 kcal./mol. for Service azide and 23.4 kcal./mol. for dextrinated azide. The large difference between these values is correlated with the difference in initiating power of the two types of azide. In § ( d ), sensitiveness to heat, percussion and friction are compared for Service and dextrin azides. General sensitiveness of Service azide is somewhat greater. Particular attention is drawn to the grit sensitiveness of Service azide.

Antistatic Modification of Lead Styphnate and Lead Azide for Surfactant Applications

2013 ◽  
Vol 38 (4) ◽  
pp. 569-576 ◽  
Author(s):  
Mingrui Zhou ◽  
Zhimin Li ◽  
Zunning Zhou ◽  
Tonglai Zhang ◽  
Bidong Wu ◽  
...  
Keyword(s):  
Lead Azide ◽  
Lead Styphnate

The sensitiveness of explosives - The sensitiveness of initiators to friction. Apparatus for measuring relative sensitiveness to grazing friction with or without grit

1948 ◽  
Vol 241 (831) ◽  
pp. 265-271
Keyword(s):  
Lead Azide ◽  
Smooth Surfaces ◽  
Break Up ◽  
Lead Styphnate

Apparatus is described for subjecting explosive compositions to grazing friction between surfaces of various materials, which can be made to move at various relative velocities up to about 15 ft./sec. Conditions for obtaining reproducible results are detailed. Tests on a number of initiators by means of this apparatus give an order of relative sensitiveness to rubbing between smooth surfaces of steel. When the rubbing occurs in the presence of grit, it is found that certain initiators such as lead azide and lead styphnate have their sensitiveness notably enhanced compared with others, such as mercury fulminate. Photomicrographs of the explosives after rubbing show very considerable break-up of the crystals even when no detonation has occurred.

Treatment of military primary explosives wastewater containing lead styphnate (LS) and lead azide (LA) by mFe 0 -PS-O 3 process

2018 ◽  
Vol 188 ◽  
pp. 860-870 ◽  
Author(s):  
Fangzhou Ji ◽  
Haoxiang Yin ◽  
Heng Zhang ◽  
Yunhong Zhang ◽  
Bo Lai
Keyword(s):  
Lead Azide ◽  
Lead Styphnate

scholarly journals The sensitiveness of explosives - Mechanical and thermal processes of initiation

1948 ◽  
Vol 241 (831) ◽  
pp. 280-286 ◽  
Keyword(s):  
Melting Point ◽  
Detonation Wave ◽  
Hot Spots ◽  
Mechanical Energy ◽  
Local Heating ◽  
High Hardness ◽  
Mechanical Action ◽  
Lead Azide ◽  
Lower Melting Point ◽  
Lead Styphnate

The sensitiveness of initiators to mechanical action has been examined in relation to heat, for lead azide, mercury fulminate, and in some cases lead styphnate, in order to see how far mechanical action could be equated with local heating. Previous information on mechanical sensitiveness has been extended by measuring friction sensitiveness with grit of varying hardness, and by varying the melting point and hardness of the rubbing surface. The percussion sensitiveness has been compared using as confining metals nickel and tin, as well as the brass normally used. The relation between sensitiveness to heat and sensitiveness to mechanical action has been investigated by determining the percussion sensitiveness of initiators partly sensitized by heating, and also by studying the delay to ignition as a function of the quantity of initiator accessible to the growth of the detonation wave. In these tests, lead azide was found to build up to limiting detonation conditions in considerably smaller quantities than mercury fulminate. It is found that grit does not appreciably sensitize initiators to friction unless it is harder than about 3.5 to 4 on Moh’s scale, and unless the rubbing surfaces have a high hardness and melting point. It is confirmed that mercury fulminate is not appreciably sensitized by grit. Percussion sensitiveness depends to some extent on the confining metal used, being rather lower for the metals of lower melting point. Extension of previous observations confirms that if lead azide or mercury fulminate is heated during half the induction period at any one temperature, and then cooled, these heat sensitized initiators will detonate in approximately half the normal time at any other temperature. However, sensitization of initiators to heat in this way has only a secondary effect on their sensitiveness to percussion. These observations together with previous work indicate the following relationships between mechanical and thermal sensitiveness. (i) In grit sensitveness , the mechanical action involves mainly the formation of 'hot spots’ between the grit and a hard surface. These hot spots acting on the initiator generate the detonation wave more easily with lead azide than with mercury fulminate, so that lead azide is more sensitive to grit than mercury fulminate. Other mechanical effects may be present in a subordinate degree. (ii) Percussion sensitiveness appears to be more complex, and may involve a tribo-chemical ‘trigger’ reaction as well as the formation of hot spots through friction. Tribo-chemical or other mechanical 'trigger reactions' are only indirectly related to the sensitiveness to heat since they involve a more direct transfer between mechanical energy and activation energy, than is involved if the mechanical energy is first converted into heat.

Experimental Determination of Thermal Kinetic Parameters in Case Study of Tubes with Smooth and Structured Surface

2015 ◽  
Vol 729 ◽  
pp. 125-128
Author(s):  
Milan Kubín ◽  
Jiří Hirš
Keyword(s):  
Kinetic Parameters ◽  
Heat Exchangers ◽  
Hot Water ◽  
Engineering Practice ◽  
Experimental Measurements ◽  
Water Steam ◽  
Structured Surface ◽  
Thermal Kinetic Parameters

Thermal kinetic parameters are very often used in the engineering practice for the simplified design of the heat exchangers. These thermal kinetic parameters must be determined from the experimental measurement. This contribution is aimed on the calculation of thermal kinetic parameters from the experimental measurements of heat exchanger water steam / hot water. In this case study are tested and compared tubes with the smooth and structured surface. Obtained results can be directly used in the engineering practice.

Energy requirements for the ignition of seven solid explosives

1958 ◽  
Vol 246 (1245) ◽  
pp. 167-175 ◽  
Keyword(s):  
Experimental Data ◽  
Minimum Energy ◽  
Analytical Techniques ◽  
Adiabatic Compression ◽  
Energy Requirements ◽  
Lead Azide ◽  
Hot Gas ◽  
Solid Explosives ◽  
Lead Styphnate

The minimum energy, delivered in a 3 ms interval, just sufficient to ignite 1 cm 2 of explosive has been investigated for the cases of trinitrotoluene, tetryl, cyclo-trimethylene trinitramine (RDX), pentaerythritol trinitrate (PETN), blasting gelatin, lead azide, and lead styphnate. Absolute values, which may be somewhat in error due to extensive corrections necessary in interpreting experimental data, range from greater than 0·4 cal/cm 2 for TNT to less than 0·1 cal/cm 2 for lead styphnate. Relative values are considered more reliable since errors in data analysis tend to cancel. A device is described for generating hot gas by adiabatic compression, together with experimental and analytical techniques for determination of ignition energies.

Environmentally Acceptable Alternatives to Lead Azide and Lead Styphnate

2007 ◽  
Author(s):  
John Fronabarger ◽  
Michael Williams ◽  
Magdy Bichay
Keyword(s):  
Lead Azide ◽  
Lead Styphnate
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