Journal articles: 'Air Blasts'

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Bartelt, Perry, Peter Bebi, Thomas Feistl, Othmar Buser, and Andrin Caviezel. "Dynamic magnification factors for tree blow-down by powder snow avalanche air blasts." Natural Hazards and Earth System Sciences 18, no. 3 (March 7, 2018): 759–64. http://dx.doi.org/10.5194/nhess-18-759-2018.

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Abstract. We study how short duration powder avalanche blasts can break and overturn tall trees. Tree blow-down is often used to back-calculate avalanche pressure and therefore constrain avalanche flow velocity and motion. We find that tall trees are susceptible to avalanche air blasts because the duration of the air blast is near to the period of vibration of tall trees, both in bending and root-plate overturning. Dynamic magnification factors for bending and overturning failures should therefore be considered when back-calculating avalanche impact pressures.

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Zhuang, Yu, Aiguo Xing, Perry Bartelt, Muhammad Bilal, and Zhaowei Ding. "Dynamic response and breakage of trees subject to a landslide-induced air blast." Natural Hazards and Earth System Sciences 23, no. 4 (April 4, 2023): 1257–66. http://dx.doi.org/10.5194/nhess-23-1257-2023.

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Abstract. Landslides have been known to generate powerful air blasts capable of causing destruction and casualties far beyond the runout of sliding mass. The extent of tree damage provides valuable information on air blast intensity and impact region. However, little attention has been paid to the air blast–tree interaction. In this study, we proposed a framework to assess the tree destruction caused by powerful air blasts, including the eigenfrequency prediction method, tree motion equations and the breakage conditions. The tree is modeled as a flexible beam with variable cross-sections, and the anchorage stiffness is introduced to describe the tilt of the tree base. Large tree deflection is regarded when calculating the air blast loading, and two failure modes (bending and overturning) and the associated failure criteria are defined. Modeling results indicate that although the anchorage properties are of importance to the tree eigenfrequency, tree eigenfrequency is always close to the air blast frequency, causing a dynamic magnification effect for the tree deformation. This magnification effect is significant in cases with a low air blast velocity, while the large tree deflection caused by strong air blast loading would weaken this effect. Furthermore, failure modes of a specific forest subject to a powerful air blast depend heavily on the trunk bending strength and anchorage characteristics. The large variation in biometric and mechanical properties of trees necessitates the establishment of a regional database of tree parameters. Our work and the proposed method are expected to provide a better understanding of air blast power and to be of great use for air blast risk assessment in mountainous regions worldwide.

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Chandra, N., S. Ganpule, N. N. Kleinschmit, R. Feng, A. D. Holmberg, A. Sundaramurthy, V. Selvan, and A. Alai. "Evolution of blast wave profiles in simulated air blasts: experiment and computational modeling." Shock Waves 22, no. 5 (July 24, 2012): 403–15. http://dx.doi.org/10.1007/s00193-012-0399-2.

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Currin, Tina Haver. "Sound Politics: The Air Horn Orchestra Blasts HB2." Southern Cultures 24, no. 3 (2018): 107–24. http://dx.doi.org/10.1353/scu.2018.0036.

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HANSON, DAVID. "Business group blasts changes in clean air bill." Chemical & Engineering News 66, no. 11 (March 14, 1988): 5. http://dx.doi.org/10.1021/cen-v066n011.p005.

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Monjezi, Masoud, Hamed Amiri, Mir Naser Seyed Mousavi, Jafar Khademi Hamidi, and Manoj Khandelwal. "Comparison and application of top and bottom air decks to improve blasting operations." AIMS Geosciences 9, no. 1 (2022): 16–33. http://dx.doi.org/10.3934/geosci.2023002.

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<abstract> The blasting operation is an integral part of mines, and it is still being used as the most economical tool to fragment and displace rock mass. Appropriate blast optimization alleviates undesirable side effects, such as ground vibration, air blasts and flyrock, and it and enhances rock fragmentation. Blast optimization can also be effective in reducing the overall mining cost. One way of reducing blasting side effects is to use deck charges instead of continuous ones. The location of the deck(s) is still considered an unanswered question for many researchers. In this study, an investigation was carried out to find an appropriate air deck position(s) within the blast hole. For this, air decks were placed at three different positions (top, middle and bottom) within a blast hole at Cheshmeh-Parvar gypsum and Chah-Gaz iron ore mines to understand and evaluate air deck location impact on blast fragmentation and blast nuisances. The results were compared based on the existing blasting practices at both mines, as well as the air-deck blasting results. The results obtained from the blasting were very satisfactory; it was found that charging with a top air deck, as compared to current blasting practices, causes a decrement in the specific charge, as well as a decrement of 38% in the back break and 50% in flyrock; the average size of fragments obtained from blasting was increased by 26%. Thus, it can be said that the top air deck is more advantageous than the bottom air deck in terms of reducing undesired blasting consequences. </abstract>

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Anas, S. M., Mehtab Alam, and Mohammad Umair. "Air-blast and ground shockwave parameters, shallow underground blasting, on the ground and buried shallow underground blast-resistant shelters: A review." International Journal of Protective Structures 13, no. 1 (October 7, 2021): 99–139. http://dx.doi.org/10.1177/20414196211048910.

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Weak political systems and poor governance in certain developing countries are found to have a war-like environment where structures are being targeted by blasts and bombs. Industrial blasts due to frail know-how and mishandlings are also quite common. Recent accidental explosions like that occurred at the Beirut Port, Lebanon (August 2020); ammunition depot in the outskirt of the Ryazan City of Russia (November 2020) are of concern for the safety of adjacent building infrastructure and their users. Such intense loading events cause damage to certain elements of a structure which may result in disproportionate or progressive collapse. It necessitates a clear understanding of the phenomenon of the blast and extreme loads induced out of it, and response of the target structure under such loadings. In this study, the state of research on air-blast and ground shockwave parameters, shallow underground blasting, and on the ground and buried shallow blast-resistant shelters are presented. The phenomenon of the self-Mach-reflection of the explosion, loading parameters and empirical blast models available in the open literature followed by the damage criteria for the buildings subjected to the underground blasting and available peak particle velocity (PPV) prediction models have been discussed. To make the application of advanced materials such as fibrous concrete, ultra-high performance concrete, FRP composites, etc., it is important to comprehend the existing blast/shock-resistant shelters and their response under such loading. The shelters are primarily designed by incorporating features of the materials like high degree of deformability/ductility, use of the shock-isolation panels and the mechanism for controlling crack formations. Finally, conclusions and recommendations for future studies are summarised. This paper presents prospects to engineers, town planners, researchers, policymakers and members of the core drafting sectional committees to understand the phenomenon of the blast and extreme loads induced out of it.

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Hoo Fatt, Michelle S., and Dushyanth Sirivolu. "Marine composite sandwich plates under air and water blasts." Marine Structures 56 (November 2017): 163–85. http://dx.doi.org/10.1016/j.marstruc.2017.08.004.

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Stokstad, E. "TOXIC AIR POLLUTANTS: Inspector General Blasts EPA Mercury Analysis." Science 307, no. 5711 (February 11, 2005): 829a—831a. http://dx.doi.org/10.1126/science.307.5711.829a.

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Fernández, Pablo R., Rafael Rodríguez, and Marc Bascompta. "Holistic Approach to Define the Blast Design in Quarrying." Minerals 12, no. 2 (January 31, 2022): 191. http://dx.doi.org/10.3390/min12020191.

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A new approach to determine the most efficient blast design was proposed, taking the peak particle velocity (PPV) as the main constraint, while including costs, production, granulometry, air blast and carbon footprint as relevant characteristics. The research was based on a case study that registered and analyzed 548 blasts over more than 10 years, while the vibration of the blast was recorded in 32% of them. A general attenuation law and several local laws were determined based on the geological conditions of the quarry. The blast design improvement allowed one to reduce the specific consumption by almost 30%, 26% of the blast cost in terms of explosive consumption and 18% of the CO2 emissions. This allowed for the achievement of a more environmentally friendly extraction system while complying with the legal standards, the quality requirements and the production and productivity conditions established.

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Tanapornraweekit, Ganchai, Nicholas Haritos, and Priyan Mendis. "Behavior of FRP-RC Slabs under Multiple Independent Air Blasts." Journal of Performance of Constructed Facilities 25, no. 5 (October 2011): 433–40. http://dx.doi.org/10.1061/(asce)cf.1943-5509.0000191.

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Wadley, H. N. G., K. P. Dharmasena, M. Y. He, R. M. McMeeking, A. G. Evans, T. Bui-Thanh, and R. Radovitzky. "An active concept for limiting injuries caused by air blasts." International Journal of Impact Engineering 37, no. 3 (March 2010): 317–23. http://dx.doi.org/10.1016/j.ijimpeng.2009.06.006.

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Tibbetts, John H. "Air-Gun Blasts Harm Marine Life across the Food Web." BioScience 68, no. 12 (November 3, 2018): 1024. http://dx.doi.org/10.1093/biosci/biy123.

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DENG, RONG-BING, and XIAN-LONG JIN. "THREE-DIMENSIONAL SIMULATION OF CONDENSED EXPLOSIVE-INDUCED FLOW PROPAGATION AND INTERACTION WITH GLASS CURTAIN WALL." Modern Physics Letters B 24, no. 09 (April 10, 2010): 833–48. http://dx.doi.org/10.1142/s0217984910022895.

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In order to carry out blast response of curtain wall, the first step is to understand the complex flow of the air blasts around the structures and predict the blast loads acting on the structures. But in earlier studies related to blast resistant design of glass curtain wall, blast flow induced by condensed explosive is not taken into account due to expensively computational resources required. Based on high performance computing, this paper presents a new three-dimensional numerical simulation method of condensed explosive-induced flow propagation and impact on a complex glass curtain wall, where the fluid is represented by solving Navier–Stokes equations with a multimaterial arbitrary Lagrangian–Eulerian (ALE) formulation. In particular, the whole analytical model consists of condensed explosive, air, detailed curtain wall system, and ground, which comprehensively represents the real fluid–structure interaction environment. Final calculation has been performed on the Dawning 4000A supercomputer based on the domain decomposition method. The flow mechanisms of blast wave rounding curtain wall is visualized and the simulated pressure history of gauge is in good agreement with the experimental result which validates this method. The present method is shown to be a useful tool for blast resistance design of curtain wall in the future.

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Stewart, Mark G., Michael D. Netherton, and Hayden Baldacchino. "Observed airblast variability and model error from repeatable explosive field trials." International Journal of Protective Structures 11, no. 2 (August 26, 2019): 235–57. http://dx.doi.org/10.1177/2041419619871305.

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Explosive field trials have been conducted to measure the peak incident pressure, impulse and time of positive phase duration following the detonation of 15 different masses of the Plastic Explosive No #4. A novel aspect of these field trials was the repeatability of tests. Eight pressure gauges collected data during each blast, and at each scaled distance. In all, 4 blasts were conducted for each scaled distance (i.e. up to 32 measurements recorded for each scaled distance) – 60 blasts were fired in total. Consequently, this repeatability of testing allowed the mean and variance of blast pressure–time histories to be quantified, with a view to better characterise the variability of a blast itself and model error variability. This article describes the explosive field trials, and the statistical analysis of blast load variability and model error for peak incident pressure, impulse and time of positive phase duration. It was found that the mean model error is close to unity with a coefficient of variation of up to 0.15 for pressure and 0.21 for impulse. The lognormal probability distribution best fits the model error data. The probabilistic models derived from these tests can be used for a variety of structural engineering applications, such as calculating reliability-based design load or partial safety factors for explosive blast loading, and estimating the probability of damage and casualties for infrastructure subject to explosive blast loading. This is illustrated for a terrorist explosive scenario involving a spherical free-air burst, where the damage modes of interest are breaching and spalling of a concrete slab. It was found that the variability of charge mass, range and model error have a significant effect on reliability-based design.

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Zohdi, T. I. "On firework blasts and qualitative parameter dependency." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, no. 2185 (January 2016): 20150720. http://dx.doi.org/10.1098/rspa.2015.0720.

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In this paper, a mathematical model is developed to qualitatively simulate the progressive time-evolution of a blast from a simple firework. Estimates are made for the blast radius that one can expect for a given amount of detonation energy and pyrotechnic display material. The model balances the released energy from the initial blast pulse with the subsequent kinetic energy and then computes the trajectory of the material under the influence of the drag from the surrounding air, gravity and possible buoyancy. Under certain simplifying assumptions, the model can be solved for analytically. The solution serves as a guide to identifying key parameters that control the evolving blast envelope. Three-dimensional examples are given.

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Hu, Zhijian, Jian Q. Fang, and Lizhi Z. Sun. "Blast effect zones and damage mechanisms of concrete bridges under above-deck car-bomb attacks." International Journal of Damage Mechanics 27, no. 8 (May 10, 2017): 1156–72. http://dx.doi.org/10.1177/1056789517708827.

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Above-deck car-bomb attacks cause significant effects on engineering structures from those of explosive blasts in the free air. In this paper, a post-disaster investigation for an existing bridge under above-deck car-bomb blast loading is presented. The crack distribution and damage deformation of the blast loaded girders are systematically investigated, and the blast effect zone is proposed to describe the blast loading distributions on girders and to characterize the girder structural behavior. The girder failure is dominated by one of the three typical damage mechanisms: shear, flexural-shear, and flexural, depending on the blast effect zone where the girder is located. The study also indicates that the isolation effect of the vehicle can significantly affect the blast loading distribution on structures, even though the isolation effect is localized in a region with a small standoff distance. It is gradually attenuated by the increase of the standoff distance. Numerical analysis is conducted to verify the findings by simulating the truck isolation effect with a steel plate.

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CHOWDHURY, MAINUL ISLAM, MD Rakib Hasan, Maruf Chowdhury, Saad Mohammad Bhuiya, and Md Saniat Rahman Zishan. "Design And Development Of Air Conditioner (AC) Monitoring And Management System." AIUB Journal of Science and Engineering (AJSE) 21, no. 3 (December 31, 2022): 132–38. http://dx.doi.org/10.53799/ajse.v21i3.260.

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Nowadays Air Conditioner (AC) has become a more important appliance in our life. Gas leakage, blockage in the evaporator and compressor coil, pipelines as well as dust in the air filters, are the major reasons behind AC explosion. Many people have been injured over the years due to AC blasts. In this paper a system is developed that uses sensor technology and smart devices to reduce AC blast. As a result, pipeline leaks or blockage fault detection system is planned and constructed using MQ-02, TTC 103, optical dust sensors for gas detection, temperature detection and for detecting dust density respectively. Also bacteria can be detected through MQ-3 gas sensor as it combines with AC refrigerant and produces ethanol. This system is also digitally connected to smart devices (cellphones) and a control device (RM MINI 3) so that user can receive a detection notification at any time and operate AC from any location. By implementing these sensors, the initial target was achieved. The work is low cost and environment friendly. Index Terms— Explosions, blockage, leakage, RM MINI 3, cellphone, refrigeration cycle, sensor, safety

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Marín, Juan Andrés, Rafael Rodríguez, María B. Díaz, and Saray Antón. "Empirical Attenuation Law for Air Blast Waves Due to the Detonation of Explosives Outdoors." Applied Sciences 12, no. 18 (September 12, 2022): 9139. http://dx.doi.org/10.3390/app12189139.

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The detonation of explosives in the open air was studied, analyzing different amounts of explosives detonated at different distances, monitoring the overpressure or air blast wave generated with the aim of determining a model, which allows to establish safety zones. A series of tests measuring the air wave with different loads and sensors placed at various distances from the origin of the explosion were carried out. The work was focused on designing full-scale trials that allowed to develop a predictive empirical method based on the calculation model of the equivalent mass of TNT. A total of 18 different gelatinous dynamite charges, placing the sensor at six different distances from the origin of the explosion, produced a total of 90 tests measuring the air wave produced by the detonation of gelatinous dynamite. Later, the outdoor detonation of 10 TNT explosive charges was analyzed to extend the model and improve its scope. With all this, it has been possible to develop a predictive model that allows assessing the overpressure generated by the detonation of a TNT-equivalent explosive charge. The results are useful to predict the air blast wave in common open-air blasts, such as those carried out with shaped charges to demolish metallic structures. On the other hand, the results are also useful to determine the air blast wave overpressure in the case of large explosive charges detonated in the open air, such as accidental explosive detonation or terrorist bombs. It is important to point out the relevance of the results achieved after the detonation of large explosive charges (more than 80 kg) simulating a type of bomb frequently used by terrorists. Reproducing the explosion on a real scale, the results are fully representative of the overpressure produced by an explosion of these characteristics without the need of extrapolating the results of tests with small loads. In addition, the detonation was carried out with TNT, which can serve as a standard to compare with any other type of explosive.

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Beliaieva, V. V. "MODELING OF THE PROCESS OF DEGASSING OF THE ROOMS AFTER THE ACCIDENT." Science and Transport Progress, no. 12 (December 25, 2006): 17–20. http://dx.doi.org/10.15802/stp2006/18461.

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A numerical model to simulate the process of pollutant transfer in rooms was developed. The numerical simulation is carried out using 3D models of pollutant transfer and potential flow. The implicit finite difference schemes are used. The results of numerical simulation of air pollution after blasts in industrial rooms are presented.

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Zaiats, Yu L., and V. V. Beliaeva. "THE NUMERICAL MODEL OF THE BUILDING VENTILATION DURING THE EMERGENCY RELEASES OF HAZARDOUS SUBSTANCES." Science and Transport Progress, no. 9 (December 25, 2005): 31–35. http://dx.doi.org/10.15802/stp2005/19908.

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A numerical model to simulate the process of pollutant transfer in rooms was developed. The numerical simulation is carried out using 2D models of pollutant transfer and potential flow. The implicit finite difference schemes are used. The results of numerical simulation of air pollution in a confined space after blasts of toxic substances have presented.

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Khristoforov., Boris. "Investigation of Shock Wave Parameters at Explosives Blasts in the Tubes with Air." Universal Journal of Engineering Science 1, no. 2 (September 2013): 28–33. http://dx.doi.org/10.13189/ujes.2013.010202.

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Karagiozova, D., G. N. Nurick, and G. S. Langdon. "Behaviour of sandwich panels subject to intense air blasts – Part 2: Numerical simulation." Composite Structures 91, no. 4 (December 2009): 442–50. http://dx.doi.org/10.1016/j.compstruct.2009.04.010.

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Tanapornraweekit, Ganchai, Nicholas Haritos, Priyan Mendis, and Tuan Ngo. "Finite Element Simulation of FRP Strengthened Reinforced Concrete Slabs under Two Independent Air Blasts." International Journal of Protective Structures 1, no. 4 (December 2010): 469–88. http://dx.doi.org/10.1260/2041-4196.1.4.469.

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Ko, Younghun, Chanhwi Shin, Youngjun Jeong, and Sangho Cho. "Blast Hole Pressure Measurement and a Full-Scale Blasting Experiment in Hard Rock Quarry Mine Using Shock-Reactive Stemming Materials." Applied Sciences 12, no. 17 (August 29, 2022): 8629. http://dx.doi.org/10.3390/app12178629.

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By increasing the effectiveness of the energy generated by the explosive charge inserted into a blast hole, stemming increases rock fragmentation. Missing or improper stemming, which can lead to the detonation gas escaping from the blast hole in advance, results not only in the waste of explosive energy and poor fragmentation but also in environmental problems, such as ground vibration, noise, flying rocks, back breaks, and air blasts. In this study, a stemming material based on a shear thickening fluid (STF) that reacts to dynamic pressure was developed. Two blasting experiments were conducted to verify the performance of the STF-based stemming material. In the first experiment, the pressure inside the blast hole was directly measured based on the application of the stemming material. In the second experiment, full-scale bench blasting was performed, and the blasting results of sand stemming and the STF-based stemming cases were compared. The measurement results of the pressure in the blast hole showed that when the STF-based stemming material was applied, the pressure at the top of the blast hole was lower than in the sand stemming case, and the stemming ejection was also lower. Full-scale bench blasting was conducted to compare the two types of stemming materials by evaluating the size of the rock fragments using image processing. The results of the two blasting experiments helped to verify that the blockage performance of the STF-based stemming material in the blast hole was superior to that of the sand stemming material.

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Morrissey, M. M., W. Z. Savage, and G. F. Wieczorek. "Air blasts generated by rockfall impacts: Analysis of the 1996 Happy Isles event in Yosemite National Park." Journal of Geophysical Research: Solid Earth 104, B10 (October 10, 1999): 23189–98. http://dx.doi.org/10.1029/1999jb900189.

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Olivier, Gerrit, and Florent Brenguier. "Interpreting seismic velocity changes observed with ambient seismic noise correlations." Interpretation 4, no. 3 (August 1, 2016): SJ77—SJ85. http://dx.doi.org/10.1190/int-2015-0203.1.

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Recent results have shown that crosscorrelating ambient seismic noise recorded in underground mines can successfully extract the seismic Green’s function between sensors. We have revisited an earlier experiment that showed that these virtual seismic sources can be used to measure changes in seismic velocity accurately enough to monitor the short- and long-term influences of a blast in an underground mine. To use this method routinely, it is important to determine the cause of velocity variations in the absence of large dynamic stress perturbations (such as blasts). It also is important to calibrate the seismic velocity changes in terms of known stress changes so the effect of mining activities can be quantified in units that can be used by geotechnical engineers. To this end, we used coda-wave interferometry to measure relative velocity variations during times where no significant blasting or microseismic activity occurred and compared it to atmospheric air pressure changes, temperature variations, and modeled tidal strain. The results indicate that atmospheric air pressure changes have a measurable influence on the long-term seismic velocity variations at depth in the absence of large dynamic stress perturbations. This influence enabled us to determine the sensitivity of the relative velocity changes to stress, where a value of [Formula: see text] was found. This calibration essentially enables us to turn each sensor pair in an underground mine into a stress meter, paving the way for geotechnical engineers to use ambient seismic noise correlations to monitor the evolution of stress and to assess seismic hazard in conjunction with conventional microseismic methods.

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Khurshid, Rukhshan, Haleema Sajid, Huma Ashraf, Sadia Majeed, Farah Hanif, and Shazia Rashid. "The Human Suffering caused by bomb containing White Phosphorus: Health Effects." Pakistan Journal of Medical and Health Sciences 16, no. 3 (March 26, 2022): 172–74. http://dx.doi.org/10.53350/pjmhs22163172.

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Background: White phosphorus cause injuries and bereavement by burning human body, by being inhaled the smoke or body exposed to burning material. Aim: To find out the Human Suffering caused by bomb containing White Phosphorus: Health effects Methodology: An Exploratory Surveys (case control study) was carried out on people who exposed to bomb blasts (white phosphorous) and shooting happened in a market of Lahore. Data was collected from 100 consented victims residing in the terrorism-affected area. The detail of personal data and health effects was recorded in a Proforma. A chi-squared test showed the differences in complains of victims on exposure. Results: Of the one hundred patients majority was male with age < 30 years and were exposed to explosion in open air space.The highest odds of feeling generalized weakness, susceptibility to fatigue was observed followed by psychological trauma, Insomnia in initial days, scared to dark and scared to close door was noted. Other complains of victims wereear drum rupture, with highest odds and it was followed by head injuries, brain injuries, head injuries causes blindness and hair loss due to shelling. Conclusion: In populated placed heavy explosive weaponries increase the risk of personal and emotional harm to general people. Key Words: Bomb Blast, psychological and respiratory problem, ear drum rupture.

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Shehu, Shaib Abdulazeez, Kudirat Oziohu Yusuf, Hareyani Zabidi, Onimisi A. Jimoh, and M. H. M. Hashim. "Blasting efficiency in granite aggregate quarry based on the combined effects of fragmentation and weighted environmental hazards." Mining of Mineral Deposits 17, no. 1 (March 30, 2023): 120–28. http://dx.doi.org/10.33271/mining17.01.120.

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Purpose. Mine and quarry operators determine blasting efficiency by the sizes of fragments, while regulatory agencies evaluate the same from the level of environmental discomfort. Thus, a conflict of interest exists. This research distinguishes fragmentation efficiency from blasting efficiency. It proposes a new approach for evaluating blasting efficiency to break the conflict of interests between the quarry operators and the regulatory agencies. Methods. Five blasting events in the FYS granite aggregate quarry have been studied, and design parameters have been obtained. As an indicator of blast-induced environmental discomfort, vibrations and air blasts are measured using a seismograph. The WipFrag desktop and Kuz-Ram model are used to assess the resulting fragmentations. Blasting efficiency is evaluated as a function of fragmentation and environmental constraints. Findings. The powder factor affects the fragment size distribution and the environmental hazards of blasting but in a conflicting manner. Increased powder factor enhances good fragmentation but results in further environmental discomfort. Blast event 4 has the highest fragmentation efficiency of 46.53%, while 3 has the highest environmental control efficiency of 69.47%. Cumulatively, blast event 4 has the highest overall blasting efficiency of 45.43%. Future research is expected to standardise this novel approach and incorporate more blasting effects. Originality. This work is the first attempt to quantify the efficiency of blasting operations in the aggregate quarry by combining the fragmentation produced and the resulting environmental hazards in a single model. Practical implications. The model proposed in this research can be adopted by quarry operators and regulatory agencies for sustainable quarrying and mining to address identified conflicts of interest between them.

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Baker, Monty T., John C. Moring, Willie J. Hale, Jim Mintz, Stacey Young-McCaughan, Richard A. Bryant, Donna K. Broshek, et al. "Acute Assessment of Traumatic Brain Injury and Post-Traumatic Stress After Exposure to a Deployment-Related Explosive Blast." Military Medicine 183, no. 11-12 (May 18, 2018): e555-e563. http://dx.doi.org/10.1093/milmed/usy100.

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Abstract Introduction Traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) are two of the signature injuries in military service members who have been exposed to explosive blasts during deployments to Iraq and Afghanistan. Acute stress disorder (ASD), which occurs within 2–30 d after trauma exposure, is a more immediate psychological reaction predictive of the later development of PTSD. Most previous studies have evaluated service members after their return from deployment, which is often months or years after the initial blast exposure. The current study is the first large study to collect psychological and neuropsychological data from active duty service members within a few days after blast exposure. Materials and Methods Recruitment for blast-injured TBI patients occurred at the Air Force Theater Hospital, 332nd Air Expeditionary Wing, Joint Base Balad, Iraq. Patients were referred from across the combat theater and evaluated as part of routine clinical assessment of psychiatric and neuropsychological symptoms after exposure to an explosive blast. Four measures of neuropsychological functioning were used: the Military Acute Concussion Evaluation (MACE); the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS); the Headminder Cognitive Stability Index (CSI); and the Automated Neuropsychological Assessment Metrics, Version 4.0 (ANAM4). Three measures of combat exposure and psychological functioning were used: the Combat Experiences Scale (CES); the PTSD Checklist-Military Version (PCL-M); and the Acute Stress Disorder Scale (ASDS). Assessments were completed by a deployed clinical psychologist, clinical social worker, or mental health technician. Results A total of 894 patients were evaluated. Data from 93 patients were removed from the data set for analysis because they experienced a head injury due to an event that was not an explosive blast (n = 84) or they were only assessed for psychiatric symptoms (n = 9). This resulted in a total of 801 blast-exposed patients for data analysis. Because data were collected in-theater for the initial purpose of clinical evaluation, sample size varied widely between measures, from 565 patients who completed the MACE to 154 who completed the CES. Bivariate correlations revealed that the majority of psychological measures were significantly correlated with each other (ps ≤ 0.01), neuropsychological measures were correlated with each other (ps ≤ 0.05), and psychological and neuropsychological measures were also correlated with each other (ps ≤ 0.05). Conclusions This paper provides one of the first descriptions of psychological and neuropsychological functioning (and their inter-correlation) within days after blast exposure in a large sample of military personnel. Furthermore, this report describes the methodology used to gather data for the acute assessment of TBI, PTSD, and ASD after exposure to an explosive blast in the combat theater. Future analyses will examine the common and unique symptoms of TBI and PTSD, which will be instrumental in developing new assessment approaches and intervention strategies.

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Kitov, I. O., J. R. Murphy, O. P. Kusnetsov, B. W. Barker, and N. I. Nedoshivin. "An analysis of seismic and acoustic signals measured from a series of atmospheric and near-surface explosions." Bulletin of the Seismological Society of America 87, no. 6 (December 1, 1997): 1553–62. http://dx.doi.org/10.1785/bssa0870061553.

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Abstract During December 1985, Soviet scientists monitored a series of high-explosive tests at a bombing range near Kustanai, Kazakhstan, in which both seismic and acoustic data were recorded at distances of 6, 9.5, and 21 km from bomb blasts at different altitudes. These data show a remarkable variety of seismo/acoustic phenomena associated with energy conversion processes at the Earth's surface, including air-coupled Rayleigh waves and acoustic signals produced by propagating seismic disturbances having phase velocities near the speed of sound in air. These data provide valuable new insights into the mechanisms responsible for the generation of seismic and acoustic signals by atmospheric and near-surface explosions. In particular, theoretical simulation results are presented that are shown to account for most of the features of the observed data, and, therefore, it is concluded that the simplified theoretical models employed in these simulations can provide a quantitative basis for assessing the effects of source and site conditions on the characteristics of the signals produced by such explosions.

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Babii, Kateryna, Leonid Novikov, and Marina Batur. "Studying the impact of single blasts in open pits on the air dustiness in the city of Krivyi Rih." Geo-Technical Mechanics 160 (2022): 33–43. http://dx.doi.org/10.15407/geotm2022.160.033.

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Soltani-Mohammadi, Saeed, Hassan Bakhshandeh Amnieh, and Moein Bahadori. "Investigating ground vibration to calculate the permissible charge weight for blasting operations of Gotvand-Olya dam underground structures / Badania drgań gruntu w celu określenia dopuszczalnego ciężaru ładunku wybuchowego przy pracach strzałowych w podziemnych elementach tamy w Gotvand-Olya." Archives of Mining Sciences 57, no. 3 (December 1, 2012): 687–97. http://dx.doi.org/10.2478/v10267-012-0044-z.

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Abstract Ground vibration, air vibration, fly rock, undesirable displacement and fragmentation are some inevitable side effects of blasting operations that can cause serious damage to the surrounding environment. Peak Particle Velocity (PPV) is the main criterion in the assessment of the amount of damage caused by ground vibration. There are different standards for the determination of the safe level of the PPV. To calculate the permissible amount of the explosive to control the damage to the underground structures of Gotvand Olya dam, use was made of sixteen 3-component (totally 48) records generated from 4 blasts. These operations were recorded in 3 directions (radial, transverse and vertical) by four PG-2002 seismographs having GS-11D 3-component seismometers and the records were analyzed with the help of the DADISP software. To predict the PPV, use was made of the scaled distance and the Simulated Annealing (SA) hybrid methods. Using the scaled distance resulted in a relation for the prediction of the PPV; the precision of the relation was then increased to 0.94 with the help of the SA hybrid method. Relying on the high correlation of this relation and considering a minimum distance of 56.2 m to the center of the blast site and a permissible PPV of 178 mm/s (for a 2-day old concrete), the maximum charge weight per delay came out to be 212 Kg.

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Kornéli, Beáta. "Nagy Britannia és Ausztrália közös atomprogramja 1945-1960." Belvedere Meridionale 31, no. 2 (2019): 153–62. http://dx.doi.org/10.14232/belv.2019.2.9.

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Australia was determined to obtain a nuclear weapon after the Second World War. The most obvious solution seemed to collaborate with Britain doing nuclear research in the so-called “joint project”. The British defence planners had been aware of the fact that Great Britain would not survive a forthcoming nuclear attack at the dawn of the cold war and thus, they were in need of their own nuclear weapon. When the MacMahon Act came into force the Government of United States of America rejected the British to continue the joint research in the Manhattan Project and they wanted to retain their sole atom monopoly. They provided the British neither with raw material nor with nuclear technology, furthermore, they were not allowed to participate in the test blasts. Hence, the role of Australia was revalued by the British Government. Several productive intitiatives such as the establishment of the Australian National University, launching the Snowy Mountains project, deployment of the Royal Australian Air Force in Southeast Asia coincided with the joint project. The culmination of the Australian–British cooperation was the atomic blast in 1952 and the decision of the British to contribute to the construction of an Australian nuclear reactor. Nevertheless, the nuclear achievements of the Soviet Union put an end to the so far successful joint project.

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Smith, Kyle D., Tao Chen, and Rong Z. Gan. "Hearing Damage Induced by Blast Overpressure at Mild TBI Level in a Chinchilla Model." Military Medicine 185, Supplement_1 (January 2020): 248–55. http://dx.doi.org/10.1093/milmed/usz309.

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Abstract Introduction The peripheral auditory system and various structures within the central auditory system are vulnerable to blast injuries, and even blast overpressure is at relatively mild traumatic brain injury (TBI) level. However, the extent of hearing loss in relation to blast number and time course of post-blast is not well understood. This study reports the progressive hearing damage measured in chinchillas after multiple blast exposures at mild TBI levels (103–138 kPa or 15–20 psi). Materials and Methods Sixteen animals (two controls) were exposed to two blasts and three blasts, respectively, in two groups with both ears plugged with foam earplugs to prevent the eardrum from rupturing. Auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) were measured in pre- and post-blasts. Immunohistochemical study of chinchilla brains were performed at the end of experiment. Results Results show that the ABR threshold and DPOAE level shifts in 2-blast animals were recovered after 7 days. In 3-blast animals, the ABR and DPOAE shifts remained at 26 and 23 dB, respectively after 14 days. Variation of auditory cortex damage between 2-blast and 3-blast was also observed in immunofluorescence images. Conclusions This study demonstrates that the number of blasts causing mild TBI critically affects hearing damage.

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Zhou, Ai-Ai, Rong-Yu Li, Fei-Xu Mo, Yi Ding, Ruo-Tong Li, Xue Guo, Ke Hu, and Ming Li. "Natural Product Citronellal can Significantly Disturb Chitin Synthesis and Cell Wall Integrity in Magnaporthe oryzae." Journal of Fungi 8, no. 12 (December 16, 2022): 1310. http://dx.doi.org/10.3390/jof8121310.

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Background: Natural products are often favored in the study of crop pests and diseases. Previous studies have shown that citronellal has a strong inhibition effect on Magnaporthe oryzae. The objective of this study was to clarify its mechanism of action against M. oryzae. Results: Firstly, the biological activity of citronellal against M. oryzae was determined by direct and indirect methods, and the results show that citronellal had a strong inhibition effect on M. oryzae with EC50 values of 134.00 mg/L and 70.48 μL/L air, respectively. Additionally, a preliminary study on its mechanism of action was studied. After citronellal treatment, electron microscopy revealed that the mycelium became thin and broken; scanning electron microscopy revealed that the mycelium was wrinkled and distorted; and transmission electron microscopy revealed that the mycelium cell wall was invaginated, the mass wall of mycelium was separated, and the organelles were blurred. The mycelium was further stained with CFW, and the nodes were blurred, while the mycelium was almost non-fluorescent after PI staining, and there was no significant difference in the relative conductivity of mycelium. In addition, chitinase was significantly enhanced, and the expression of chitin synthesis-related genes was 17.47-fold upregulated. Finally, we found that the efficacy of citronellal against the rice blast was as high as 82.14% according to indoor efficacy tests. Conclusion: These results indicate that citronellal can affect the synthesis of chitin in M. oryzae and damage its cell wall, thereby inhibiting the growth of mycelium and effectively protecting rice from rice blasts.

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del Mar, Nobel, Xinyu von Buttlar, Angela S. Yu, Natalie H. Guley, Anton Reiner, and Marcia G. Honig. "A novel closed-body model of spinal cord injury caused by high-pressure air blasts produces extensive axonal injury and motor impairments." Experimental Neurology 271 (September 2015): 53–71. http://dx.doi.org/10.1016/j.expneurol.2015.04.023.

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Moritania, Rizky, Irwan Effendi, and Feliatra Feliatra. "ISOLATION AND ANTAGONISM OF BACTERIA TEST OF BIOTA IN THE MANGROVE ECOSYSTEM KAYU ARA RIVER SIAK REGENCY." Asian Journal of Aquatic Sciences 2, no. 3 (January 24, 2020): 190–96. http://dx.doi.org/10.31258/ajoas.2.3.190-196.

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The General area is the mangrove biodiversity and marine life that have biological activity that likely has the same pharmacological potential as an antimicrobial compound. The purpose of this research is to know the bacterial antagonism in isolation from mangrove, mangrove crabs, snails and fish tembakul against pathogenic bacteria (Aeromonas hydrophila, Aeromonas salmonicida, Edwardsiella ictaluri). This research dimula from May – June 2019. From the results of research that has been done shows that isolates that have the capability of antagonism against pathogenic bacteria test three (A. salmonicida, A. hydrophila and E. ictaluri) were isolate CS7 with category stronger, isolate CS6, CS5, CS4, AI4, AI5, CS9 AI2, with weak category, whereas isolates CS1, B22, B33, B44, AI6 AI7 AI8, was only able to inhibit pathogenic test of 2 with a weak category. The results of the DNA analysis of the 16S rRNA sequence with the use and analysis of BLAST obtained that isolates the Bacillus cereus species are included.

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Rao, G. Kumaraswamy, Sreehari Rao, and Sudhir Kumar Chaudhuri. "Networking of Tracking Radars of Two Different SAM Weapons to Protect the Missile in Intensive Jamming Environment." Defence Science Journal 68, no. 1 (December 18, 2017): 70. http://dx.doi.org/10.14429/dsj.68.10993.

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Many countries including India use the Russian made SAM-3 (Pechora) surface-to-air missile (SAM) weapon systems to protect their strategic and tactical infrastructure. The mathematical computations done in this paper, conclusively proves that SA-125 low-blow tracking radar of Pechora is vulnerable to jamming. A project was undertaken to overcome the jamming vulnerability of Pechora aiming to design and develop an electronic counter counter measure system. This system networked the Pechora tracking radar with a western tracking radar, Flycatcher, developed by HSA Holland. The latter radar works in a MMW band. When jamming (x band) is employed by enemy aircraft the Low blow radar failed to provide target coordinates. But the flycatcher tracking radar which is tracking in Ka band provided the tracking coordinates (after parallax correction) to the command guidance computer. This way the missile guidance is protected until missile warhead in missile blasts near the target. Extensive trials carried out with a number of aircraft sorties proved the success of this developed system against jamming.

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Geshma Kumari, Remala, Arivukkannu Ezhilarasi, and Naresh Pasula. "A novel single switch controlled efficient coupled inductor-based DC-DC boost converter." Indonesian Journal of Electrical Engineering and Computer Science 32, no. 1 (October 1, 2023): 61. http://dx.doi.org/10.11591/ijeecs.v32.i1.pp61-70.

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Pollution is one of the most hazard facing in the world. Day by day pollutions has been increased in the society due to population growth, industries, constructions, and transportation. As per the world health organization (WHO) survey, 45% of the air pollution is due to transportation because they lay on internal combustion engine (ICE) based engines. To avoid carbon footprints, green transportation should be encouraged for further generations. In recent days many electric vehicles (EV’s) are found in the market but facing some issues like battery blasts, storage limitations and lack of charging infrastructure. Out of these issues, mainly my focus is on developing a compact, efficient, simple, medium gain coupled inductor-based DC-DC boost converter is proposed which is helpful for fast charging system. In this paper, coupled inductor (CI) and switched coupled inductor (SCI) based converters are designed and analysed with mathematical approach. The outputs of both CI and SCI converters are verified and compared with simulation results and as well CI based converter is developed with hardware prototype and verified hardware and simulation results in terms of gain, elements and efficient.

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Kamble, S. K., Kale Rekha Sachin, and Ashish Bhagat. "Stone Slurry in Cement Concrete for Sustainable Use in Civil Engineering Work." IOP Conference Series: Earth and Environmental Science 1193, no. 1 (June 1, 2023): 012020. http://dx.doi.org/10.1088/1755-1315/1193/1/012020.

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Abstract The stone industry’s waste is to blame for a slew of environmental issues. The stone waste is rarely degradable and contribute to environmental hazards. The flowing of stone slurry with rainwater also pollutes the water bodies. This contaminated water has an impact on irrigation and drinking water supplies. Fine particles of by inhaling the stone slurry that flew with the air blasts, a major health concern was created. Fine particles of stone slime buildup on the leaves of plants, trees, and other vegetation, causing aesthetic issues. As 70 percent of wastes and only 30% of major product recovery contribute to the highest amount of indestructible wastes, plants and trees perish as a result of stone dust accumulation over leaf vegetation. The most effective method of reducing stone slurry pollution is to use it in bulk. The building sector is the only industry that can consume substantial amounts of stone slurry. The fineness modulus is 0.91, and the specific gravity is 2.61. Stone slurry replaces 30% of the sand in Cement Concrete, resulting in more strength than the Control, which is 1:1.5:3 Cement Concrete with 0% Stone slurry. In the building business, stone slurry may be easily used to make cement concrete.

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Acs, Geza, and Virginia A. LiVolsi. "Loss of Membrane Expression of E-Cadherin in Leukemic Erythroblasts." Archives of Pathology & Laboratory Medicine 125, no. 2 (February 1, 2001): 198–201. http://dx.doi.org/10.5858/2001-125-0198-lomeoe.

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Abstract Context.—The special societal relationships existing between various cell types in bone marrow suggests that there may be a link between the adhesive characteristics of hematopoietic cells and their maturation. Egress of the developing hematopoietic cells is also a highly regulated process governed by adhesive interactions. In leukemia, immature blasts are not retained within the marrow, suggesting a breakdown of adhesive mechanisms. Recent reports suggest that E-cadherin, an epithelial adhesion molecule, is expressed on erythroid precursors and megakaryocytes, but not on other hematopoietic marrow elements. Objective.—To characterize the expression pattern of E-cadherin in normal and leukemic erythroid precursors by immunohistochemistry in paraffin-embedded tissue and bone marrow aspirate smears. Methods.—Five normal bone marrow specimens from rib resections, 15 trephine bone marrow biopsy specimens, and 6 bone marrow aspirate smears from the iliac crest of patients with no known leukemia were selected. Fourteen bone marrow biopsy specimens from patients with erythroleukemia were also studied. Immunoperoxidase staining of paraffin-embedded tissue and air-dried aspirate smears for E-cadherin (1:200 dilution, HECD-1 clone) was performed using the avidin-biotin peroxidase technique. Results.—In paraffin-embedded bone marrow biopsy and rib specimens and in air-dried bone marrow aspirate smears, strong membrane expression of E-cadherin was seen in the normal erythroid precursors in all cases. In contrast, no membrane expression of E-cadherin was present in any of the bone marrow biopsy specimens from patients with erythroleukemia. Conclusions.—Immunohistochemical detection of membrane expression of E-cadherin may be a useful tool for identification of erythroid precursors. Cells of erythroleukemia lack membrane expression of E-cadherin, in contrast to their normal counterparts. Further studies are needed to define the potential role of E-cadherin in the maturation of erythroid precursors and to ascertain the significance of loss of membrane expression of E-cadherin in erythroleukemia.

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Roudini, M., and G. Wozniak. "Investigation of the Secondary Atomization in Prefilming Air-Blast Atomizers." International Journal of Chemical Engineering and Applications 10, no. 5 (October 2019): 138–43. http://dx.doi.org/10.18178/ijcea.2019.10.5.757.

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Cao, Cheng, Yaping Gao, Shaolin Wang, Fuqiang Liu, Cunxi Liu, Yong Mu, Deqing Mei, and Gang Xu. "Numerical Investigation on Mechanism of Swirling Flow of the Prefilming Air-Blast Fuel Injector." Energies 16, no. 2 (January 5, 2023): 650. http://dx.doi.org/10.3390/en16020650.

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Prefilming air-blast atomizers are widely used in modern gas turbine combustors. Due to insufficient awareness of the coupling mechanism of multi-stage swirling flow in gas turbines, there is a lack of effective methods for flow field optimization in combustor. In this study, the effect of some critical parameters on the flow field of a prefilming air-blast atomizer was analyzed with CFD. The parameters include the angle and number of the first swirler blades, the angle of the second swirler blades and the angle of sleeve. Furthermore, the coupling mechanism of two-stage swirling airflows of prefilming air-blast atomizer was discussed. Moreover, the influence of the interaction between two-stage counter swirling airflows on the characteristics of flow field was explained. The results show that with the increase in SNi, the axial length of the primary recirculation zone decreased, while the radial width increased. The starting position of primary recirculation zone (PRZ) moves forward with the increase in SNo. Reducing the sleeve angle β helps to form the primary recirculation zone. The results indicate that it is the transition of tangential velocity of airflow to radial velocity that promotes the formation of the PRZ. These results provide theoretical support for optimization of the flow field in swirl combustor.

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Wang, Rui Yun, Jin Yu Yin, and Su Ping Cui. "Numerical Simulation of Internal Flow Field in Blast Furnace Slag Dry Granulating Device." Materials Science Forum 944 (January 2019): 1199–207. http://dx.doi.org/10.4028/www.scientific.net/msf.944.1199.

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In this paper, CFD numerical simulation method was adopted to study the internal flow field of experimental dry granulating device of blast furnace slag and to research the impact of equipment structure and wind speed on cooling effectiveness. Main content included the internal flow field uniformity under different blade type and number of inlets. The results showed that the internal flow field in strip-blades device was more uniform than fan-shaped blades device. With the increase of air inlets quantity, the internal flow field in device became more uniform and stable, especially when there were 8 air inlets in the equipment.

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Bruccoliere, Anthony, Bridget Boeger, Alan Pang, and John Griswold. "712 Added Effect, Injuries, And Complications Of Blast Injuries Among Burn Patients On Resuscitation And Outcomes." Journal of Burn Care & Research 44, Supplement_2 (May 1, 2023): S134. http://dx.doi.org/10.1093/jbcr/irad045.187.

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Abstract Introduction Major burn injuries present as complex cases due to the hemodynamic and cardiodynamic changes that occur following the injury which can lead to the development of sepsis, multiple organ failure, and death[1]. Complexity of these cases increase furthermore with the inclusion of explosion induced injuries. Concussive explosive forces can be particularly devastating for air containing organs like the lung, bowel and middle ear [8]. In explosion-related cases, “the mortality correlated significantly with higher burned total body surface area (TBSA), higher abbreviated burn severity index (ABSI) score, accompanying inhalation injuries, and lung contusions” [2]. Cardiac blast traumas may occasionally result directly from blast energy but are more often presented as indirect coronary emboli [4]. Explosive energies have been observed to induce bradycardia, hypotension, and apnea [5]. Although more common in underwater blasts, small bowel perforations can result directly from an explosion or indirectly up to 2 weeks following the explosion [4]. A longer ICU length of stay is also associated with patients suffering from an explosion event [7]. Methods Through a hypothesis-driven retrospective study, we isolated a group of 68 burn patients, ages 18-85, from 2010-2017 that fit our criteria. Inclusion to the test group required the presence of an injury related to an explosion that resulted in a TBSA% greater than 10%. We then collected data and compared that to the outcomes of patients who had burn injuries not caused by an explosion. The control group had statistically similar age, TBSA percentage, and comorbidities. We compared major outcomes such as length of stay, length of time on a ventilator, and mortality rates. Results When controlled for age, TBSA %, presence of inhalation injuries and comorbidities, the explosion group had significantly higher mortality rates (p< 0.001). The length of stay and length of intubation were not significantly different for the explosion group. The incidence of sepsis in the explosion group was nearly significant with a p-value of 0.051. Conclusions After analyzing the data, we conclude that patients experiencing an explosion experience higher mortality rates than burn patients of similar age, TBSA%, and comorbidities. The shockwave present in explosion cases likely causes additional injuries to patients that decrease survivability. There was indication that sepsis or infection events may be more likely in patients experiencing an explosion, but results nearly missed the standard of significance. Due to the relatively small sample size of 68 patients, some of the data might be limited in its generalizability. A larger study could provide more insight into the outcomes of patients experiencing explosions. Applicability of Research to Practice The effect of explosions on mortality provides an opportunity for quality improvement research and development of improved methods for treating explosion involved burn injuries.

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Li, Li Feng, Xi Bing Li, Hai Peng Ma, and Jiang Feng Xie. "Blast-Induced Cumulative Effects in Surrounding Rock of Largespan Tunnel under Multiple Blasts." Advanced Materials Research 378-379 (October 2011): 498–501. http://dx.doi.org/10.4028/www.scientific.net/amr.378-379.498.

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The blasting vibration derived from multiple blasts and its effects on surrounding rock in a longspan tunnel will probably give rise to cumulative damage of surrounding rock, and weaken surrounding rock’s stability. Blastmate III, made by the Canadian company Instantel, is utilized to monitor the vibration signals from multiple blasts. Blasting vibration decay law and allowed safety distance of blasting are calculated by using Sadaovsk formula. Then, cumulative effects are analyzed by Hilbert-Huang Transform method as well as consequential instantaneous energy spectrum, and UTEP is presented to indicate the change of cumulative effects and damage in surrouding rock. The research shows that during the progress of damage evolution, “strengthening” and” deteriorating” may alternately appear several times. This is a zigzag reciprocating process in damage evolution of surrounding rock.

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Isakson, P. C., D. D'Angelo, J. Schetz, L. Tardelli, and E. Puré. "Anti-Ig-stimulated B lymphoblasts can be restimulated via their surface Ig." Journal of Immunology 143, no. 12 (December 15, 1989): 3901–8. http://dx.doi.org/10.4049/jimmunol.143.12.3901.

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Abstract Engaging AgR (surface Ig) on B lymphocytes leads to rapid inositol phosphate turnover and elevation of intracellular [Ca2+]. Continuous receptor occupancy (greater than 18 h) by anti-Ig leads to transit of most B lymphocytes from G0 to G1 stage of the cell cycle (blast transformation); a fraction of cells continue into S phase but do not proliferate continuously in the absence of growth factors. Prolonged exposure to ligand can induce receptor desensitization of some receptors. We therefore investigated whether such desensitization occurs in B cells activated by insolubilized anti-Ig. Resting B cells and anti-Ig-activated blasts were examined for their potential to elevate [Ca2+]i, maintain viability, and synthesize DNA in response to reexposure to anti-Ig. B cells and anti-Ig blasts had similar basal [Ca2+]i levels. Anti-Ig blasts retained the capacity to increase [Ca2+]i in response to anti-Ig; the magnitude of the increase was equal to or greater than that observed with resting B cells and occurred in more than 90% of cells. Isolated anti-Ig blasts subcultured in the presence of T cell-derived growth factors for 3 to 5 days responded to restimulation by anti-Ig with an increase in [Ca2+]i similar to that observed in freshly isolated blasts. The B cell and B lymphoblast ion channels were found to be permeable to Ca2+ but impermeable to Mn2+. Finally, blasts restimulated by anti-Ig retained viability and incorporated low levels of [3H]thymidine for 24 h. These results suggest that AgR on activated B lymphocytes can remain functionally coupled to intracellular signaling pathways and can participate in immune responses subsequent to initial activation.

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Andrade, W., M. Ribeiro, C. Lima, F. Santos, and F. Biulchi. "Pillar recovery using new wireless blasting technology: a case study in Vazante mine, Brazil." Journal of Mining Engineering and Research 3, no. 1 (August 17, 2021): 20–25. http://dx.doi.org/10.35624/jminer2021.01.03.

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The application of explosives has never been considered as a major influencing factor during either the designing of a mine or the selection of the mining method. However, this has changed with the launch of WebGenTM wireless blasting system, which allowed underground mines to exploit their orebody applying methods previously not possible due to limitations imposed by the use of wired detonators. The wireless blasting system is based on magnetic induction communication, and its signal is capable of overcoming hundreds of meters through rock, water, and air, to reach individual primers in the blastholes without any physical connection.A noble application of wireless detonators is being used in Vazante mine, Brazil, an underground zinc mine where ore pillars are left in the mined stope to secure stability and minimize dilution by limiting the hydraulic radius. The recovery of these pillars is financially desirable but involves extra time and costs associated with scaling, backfilling, reinstalling infrastructure, accessing areas previously blasted (less stable), drilling, charging with explosives, and subsequently, firing and mucking out the blasted material with expected high dilution. Applying 100% wireless detonators made it possible to safely preload the pillar together with production blasts before losing access to the area, a method named Temporary Rib Pillar (TRP). After all the stope is mined and the pillar accomplished its objectives, the primers are initiated without neither the need for the extra cycles described previously, nor the need to re-enter the area. Thus, it was possible to reduce the exposure of people and equipment, reduce operational cycles, and increase ore recovery, directly contributing to anticipate the ore production while guaranteeing the safety of the teams involved.

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Mistlberger, R. E., M. C. Antle, I. C. Webb, M. Jones, J. Weinberg, and M. S. Pollock. "Circadian clock resetting by arousal in Syrian hamsters: the role of stress and activity." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 285, no. 4 (October 2003): R917—R925. http://dx.doi.org/10.1152/ajpregu.00222.2003.

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Circadian rhythms in the Syrian hamster can be markedly phase shifted by 3 h of wheel running or arousal stimulation during their usual daily rest period (“subjective day”). Continuous wheel running is predictive but not necessary for phase shifts of this “nonphotic” type; hamsters aroused by gentle handling without running can also show maximal shifts. By contrast, physical restraint, a standard stress procedure and thus presumably arousing, is ineffective. To resolve this apparent paradox, phase-shifting effects of 3-h sessions of restraint or other stress procedures were assessed. In a preliminary study, phase shifts to arousal by gentle handling were significantly potentiated by the cortisol synthesis inhibitor metyrapone, suggesting that stress-related cortisol release may inhibit phase shifts to arousal. Next, it was confirmed that restraint in the subjective day does not induce phase shifts, but behavioral observations revealed that it also does not sustain arousal. Restraint combined with noxious compressed air blasts did sustain arousal and induced a significant cortisol response compared with arousal by gentle handling but did not induce shifts. Restraint combined with continuous horizontal rotation was also ineffective, as was EEG-validated arousal via confinement to a pedestal over water. However, 3 h of resident-intruder interactions (an intense psychosocial stress) or exposure to an open field (a mild stress) did induce large shifts that were positively correlated with indexes of forward locomotion. The results indicate that large phase shifts associated with arousal in the usual sleep period are neither induced nor prevented by stress per se, but are dependent on the expression of at least low levels of locomotor activity. Sustained arousal alone is not sufficient.

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Journal articles on the topic 'Air Blasts'

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