Study and Development of the Components of Gas Generator Compositions Based on the Ammonium Nitrate to Improve Blasting Operations Safety

2021 ◽  
pp. 47-52
Author(s):  
D.A. Bayseytov ◽  
◽  
M.I. Tulepov ◽  
Zh.A. Amir ◽  
A.Ye. Orazbayev ◽  
...  
Keyword(s):  
Ammonium Nitrate ◽  
Aluminum Powder ◽  
High Explosive ◽  
Low Cost ◽  
Combustion Products ◽  
Gas Generator ◽  
Toxic Gases ◽  
Carbon Black Powder ◽  
Urgent Task ◽  
Low Sensitivity

The article is devoted to the study and development of the components of gas generator compositions based on the ammonium nitrate to improve safety of blasting operations. This is primarily due to the low cost of ammonium nitrate, low sensitivity to mechanical and detonation effects and a significantly lower content of harmful compounds in the combustion products compared to the analogues. PA-4 aluminum powder was used as fuel, carbon black powder — as a gas-forming agent. The effect was studied concerning different amounts of aluminum powder on the combustion characteristics of a gas generator composition based on the ammonium nitrate. Calculated and experimental data showed that it is unreasonable to introduce more than 5 % of aluminum into the composition. According to the results of the conducted study, a gas generator composition based on the ammonium nitrate was developed to increase blasting operations efficiency and safety. Laboratory and polygon studies confirmed the efficiency and safety of using gas generator compositions at the destruction of stone. Destruction of the stone occurred without scattering of individual fragments, formation, and propagation of an air shock wave. Thus, the urgent task is to ensure blasting operations safety using gas generator compositions, which will allow to eliminate the formation of harmful, toxic gases and the high explosive effect.

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

scholarly journals Molecular Dynamics Simulation of the Influence of RDX Internal Defects on Sensitivity

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 329
Author(s):  
Pengmin Yan ◽  
Xue Zhao ◽  
Jiuhou Rui ◽  
Juan Zhao ◽  
Min Xu ◽  
...  
Keyword(s):  
Energetic Materials ◽  
Low Cost ◽  
Relative Sensitivity ◽  
Dynamics Simulation ◽  
Safety Properties ◽  
Internal Defects ◽  
X Ray ◽  
X Ray Computed ◽  
Low Sensitivity ◽  
Higher Sensitivity

The internal defect is an important factor that could influence the energy and safety properties of energetic materials. RDX samples of two qualities were characterized and simulated to reveal the influence of different defects on sensitivity. The internal defects were characterized with optical microscopy, Raman spectroscopy and microfocus X-ray computed tomography technology. The results show that high-density RDX has fewer defects and a more uniform distribution. Based on the characterization results, defect models with different defect rates and distribution were established. The simulation results show that the models with fewer internal defects lead to shorter N-NO2 maximum bond lengths and greater cohesive energy density (CED). The maximum bond length and CED can be used as the criterion for the relative sensitivity of RDX, and therefore defect models doped with different solvents are established. The results show that the models doped with propylene carbonate and acetone lead to higher sensitivity. This may help to select the solvent to prepare low-sensitivity RDX. The results reported in this paper are aiming at the development of a more convenient and low-cost method for studying the influence of internal defects on the sensitivity of energetic materials.

An analytical and experimental study of a hybrid rocket motor

2014 ◽  
Vol 228 (13) ◽  
pp. 2475-2486 ◽  
Author(s):  
Hadi Rezaei ◽  
Mohammad Reza Soltani
Keyword(s):  
Flow Rate ◽  
Low Cost ◽  
Specific Impulse ◽  
Combustion Products ◽  
Rocket Motor ◽  
Chamber Pressure ◽  
Hybrid Rocket ◽  
Hybrid Rocket Motor ◽  
Chemical Propulsion ◽  
Rate Case

The hybrid rocket motor is a kind of chemical propulsion system that has been recently given serious attention by various industries and research centers. The relative simplicity, safety and low cost of this motor, in comparison with other chemical propulsion motors, are the most important reasons for such interest. Moreover, throttle-ability and thrust variability on demand are additional advantages of this type of motor. In this paper, the result of an internal ballistic simulation of hybrid rocket motor in a zero-dimensional form is presented. Further to validate the code, an experimental setup was designed and manufactured. The simulation results are compared with the experimental data and good agreement is achieved. The effect of various parameters on the motor performance and on the combustion products is also investigated. It is found that increasing the oxidizer flow rate, increases the pressure and specific impulse of the motor; however, the slope of the specific impulse for the high flow rate case reduces. In addition, by increasing the combustion chamber pressure, the specific impulse is increased considerably. The initial diameter of the fuel port does not have significant effect on the pressure chamber and on the specific impulse. Addition of a percentage of an oxidizer like ammonium perchlorate to the fuel increases the specific impulse linearly.

scholarly journals APPLICATION OF METHODS OF ASSOCIATED PETROLEUM GAS UTILIZATION FOR THE EASTERN SIBERIA

2016 ◽  
pp. 93-97
Author(s):  
D. G. Lapin ◽  
D. A. Fomin ◽  
B. B. Kvesko
Keyword(s):  
Oil And Gas ◽  
Combustion Products ◽  
Oil Reservoir ◽  
Eastern Siberia ◽  
Gas Generator ◽  
Associated Petroleum Gas ◽  
Associated Gas ◽  
Gas Utilization ◽  
Oil And Gas Companies ◽  
Theoretical Amount

The article considers the most effective and environmentally friendly methods of utilization of associated petroleum gas (APG) for advanced oil and gas companies, as well as the developed method of utilization of associated gas using downhole steam-gas generator. The downhole steamgas generator burns APG at the bottomhole in the combustion chamber, and the combustion products - nitrogen and carbon dioxide - are supplied to the oil reservoir. A method for calculating the theoretical amount of air and combustion products is proposed.

scholarly journals Cadmium-Sensitive Measurement Using a Nano-Copper-Enhanced Carbon Fiber Electrode

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4901
Author(s):  
Jian Wu ◽  
Zhipeng Xu ◽  
Xian Wang ◽  
Li Wang ◽  
Huadong Qiu ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Low Cost ◽  
Mass Transfer Rate ◽  
Linear Range ◽  
The Body ◽  
Detection Sensitivity ◽  
Cadmium Ion ◽  
Low Sensitivity ◽  
Carbon Fiber Electrode ◽  
Fiber Electrode

Enrichment of cadmium ion (Cd2+) from the environment may lead to kidney disease and weakened immunity in the body. Current techniques are not convenient enough to measure Cd2+ concentration in the environment due to low sensitivity and poor linear range. In this paper, a new measurement technique is proposed using a new sensing electrode made of nano-copper-enhanced carbon fiber. Nano-copper was deposited onto the surface of carbon fiber to enhance the current concentration and mass transfer rate of Cd2+ during measurement, which improved the electrochemical detection sensitivity significantly (by up to 3.7 × 108 nA/nM) and broadened the linear range to 10~105 nM. This device provides a low-cost solution for measuring Cd2+ concentration in the environment.

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