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We present evidence that in ~ 1650 BCE (~ 3600 years ago), a cosmic airburst destroyed Tall el-Hammam, a Middle-Bronze-Age city in the southern Jordan Valley northeast of the Dead Sea. The proposed airburst was larger than the 1908 explosion over Tunguska, Russia, where a ~ 50-m-wide bolide detonated with ~ 1000× more energy than the Hiroshima atomic bomb. A city-wide ~ 1.5-m-thick carbon-and-ash-rich destruction layer contains peak concentrations of shocked quartz (~ 5–10 GPa); melted pottery and mudbricks; diamond-like carbon; soot; Fe- and Si-rich spherules; CaCO3 spherules from melted plaster; and melted platinum, iridium, nickel, gold, silver, zircon, chromite, and quartz. Heating experiments indicate temperatures exceeded 2000 °C. Amid city-side devastation, the airburst demolished 12+ m of the 4-to-5-story palace complex and the massive 4-m-thick mudbrick rampart, while causing extreme disarticulation and skeletal fragmentation in nearby humans. An airburst-related influx of salt (~ 4 wt.%) produced hypersalinity, inhibited agriculture, and caused a ~ 300–600-year-long abandonment of ~ 120 regional settlements within a > 25-km radius. Tall el-Hammam may be the second oldest city/town destroyed by a cosmic airburst/impact, after Abu Hureyra, Syria, and possibly the earliest site with an oral tradition that was written down (Genesis). Tunguska-scale airbursts can devastate entire cities/regions and thus, pose a severe modern-day hazard.

In the case of an uncontrolled demolition or a terrorist attack no prior knowledge is usually available as to what the exact explosives is and what the exact charge weight is. As well, in most cases the authorities have no idea what the target is to be in advance of an attack. For a designer to design a structure to minimize the damage in such cases is somewhat difficult if not impossible but, nevertheless, it must be done. Once the explosive, either as an improvised explosive device or vehicle improvised explosive device, has detonated the normal aftermath of such events such as fragmentation, primary and secondary fires, ground cratering and building collapse are all obvious. From a designers’ point of view, the starting point is to understand in detail all building collapse mechanisms to be able to design for such events and so allow time, if possible, for all those caught inside a building to escape and for structural damage to be minimized. To obtain such design parameters the designer must refer to past uncontrolled demolitions on Australian soil or in countries close by to gauge the most likely threat. Prior to design commencing one also must have clear criteria and strategy in mind to be able to complete a suitable design to ensure his obligation to allow time for people to escape from its collapse is met and damage is minimized. Designers not only have to address new building designs to withstand blast and ballistic loadings but also how to retrofit existing buildings cost effectively against such blast and ballistic loadings. Detailed lists of required criteria and strategies that are necessary so at to arrive at a suitable design for any blast or ballistic loadings likely to being applied to a structure are provided within the paper based on all aspects of an uncontrolled demolition (explosion) that may confront a designer.

In cases of terrorist bomb attacks, the issue of victim identification is the principal aim. For investigators and justice, terrorists must also be identified in a timely manner. The fragmentation of bodies caused by explosive devices however makes this operation difficult. The cases presented correspond to six autopsies of perpetrators carrying explosives. Their explosive belts produced different body sections on areas correlated with the location on the body of carrying explosive charges. Indeed, cross-sectional areas are the signature of the level of explosive devices on the body, and some fracture features through the damage of certain areas of constitutional weaknesses are specific elements to consider. These elements can allow a quick distinction between victims and terrorists, in order to assist in the medico-legal process of identification.

Drilling and blasting play an important role in operation cycle of a mine or quarry. Optimum blast design plays a pivotal role to achieve maximum utilization of explosive energy and blast fragmentation. Only 20 to 30% of explosive energy is utilized for fracturing and fragmentation of rock, and the rest of the energy is converted in noise, air overpressure, ground vibration, etc. It has been observed that using the low-density explosive may reduce the deleterious effect of engineering blasting with desired blast fragmentation. This paper substantiates this fact wherein distinct explosive energy utilization enhancement has been achieved with the use of low-density explosive and reduces ground vibration. This paper outlines the on-field assessment of low-density explosive in Quarry AB of Tata Steel West Bokaro Division. It is a solid sensitized emulsion blend. It comprises products designed for blasting in dry, dewatered, and wet blast-hole applications. Low-density explosive provides the capability to better match explosive performance to ground conditions. Being a low-density, low-energy explosives, it provides an added benefit of reducing the environmental effects of blasting. The key objective of the field assessment was to test the on-field performance of the new low-density bulk products and its effects on blast-induced ground vibration and air overpressure.

Designers who design structures to mitigate against blast loadings (Remennikov 2007) have another duty and that is to design for the effects of fragmentation not only caused from bulk explosives, but also impact from projectiles. Impact causes damage to a structure and inevitably results in debris from penetration and perforation (breach) of the structural elements. This debris is in fact the result of the damage outcome to a structure either from the blast loading or projectile impact. Fragmentation (Bangash 2006) is the end result of the blast waves impacting the structural elements resulting in scabbing and spall both of which manifest themselves in the production of fragmentation. This fragmentation is propelled outwards at velocity causing supplementary damage to the structure, adjoining structures and individuals caught near the fragmentation. Those designing for fragmentation must consider many parameters from the geometry of the impacted structural element, to the velocity of the fragments, the weight of the fragments and the range of the fragments. As has been said the fragments cause damage and the designers overall duty is to design to mitigate against damage and death or injury to individuals. The pool of worldwide knowledge on this topic is growing exponentially particularly as the need arises with weapons of high velocity and sophisticated projectiles of extreme lethality and range.

In medico-legal literature, only a small number of publications deal with lethal injuries caused by shots with modified guns. This might lead to the conclusion that such cases are extremely rare. However, there are cases again and yet again. During the investigation process, the modified gun is of particular importance since it can show an unusual ballistic behaviour. The present paper reports on a suicide of a 60-year-old man, committed with a modified revolver and a lead bullet. The man had a single gunshot wound with entrance at the right temporal bone. Autopsy revealed that the bullet had fragmented into two major parts. The smaller one stood outside the cranial cavity and pushed its way alongside between the cranial bone and scalp to its end position in the left temporal area. The bigger part entered the cranial cavity and ended in the left parietal lobe. In shots on ballistic soap and on a head-model, the ballistics of the weapon and lead bullet were characterized. The angle necessary for bullet fragmentation was determined by shots on ballistic soap and turned out to be 55°-60° at a velocity of around 200 m/s. This knowledge was transferred to contact shots on a head-model consisting of a layered polyurethane sphere filled with 10 % ballistic gelatine and covered with a skin-like cap almost all around. The resulting injury pattern corresponded to the one of the suicide person. The bigger bullet part entered the skull while the smaller part pushed its way alongside between skin and skull causing an outer contour shot. Furthermore, the revolver was documented firing off two bullets by one trigger pull-a phenomenon of importance for forensic casework the authors have not found reported in forensic literature.

A computational method is used to study processes for obtaining super-fragmented metallic materials and products made from them (strands or filaments reduced to nanometers). The article examines three problems concerning the super-fragmentation of long metallic bodies by electrostimulation rolling in grooves and passes. Super-fragmentation is used to obtain experimental metallic nanomaterials and products that could not be obtained by traditional methods of rolling.

Experimental evidence from a wide range of sources shows that the expanding cloud of explosively disseminated material comprises “particles” or fragments which have different dimensions from those associated with the original material. Powders and liquids have often been used to surround explosives to act as blast mitigants, and this is the main driver for our research. There are also many other areas of interest where an initially intact material surrounding an explosive charge is dynamically fragmented into a distribution of fragment sizes. Examples of such areas include fuel air explosives and enhanced blast explosives as well as quasi-static pressure mitigation systems, and our studies are thus also relevant to these applications. In this paper, we consider the processes occurring as an explosive interacts with a surrounding layer of liquid or powder and identify why it is important to model these processes as a multiphase material problem as opposed to a single phase, single material velocity problem. We shall present results from this class of numerical modelling. In this paper we shall explore what determines the particle or fragment size distribution resulting from explosive dissemination of a layer of material and discuss reasons why clouds from disseminated liquids and powders look similar. We shall support our analysis with results from recent explosives trials and introduce early results from some ongoing small scale explosive mitigation experiments.

Results of an experimental study of fragmentation effects in the explosion and the piercing power of the fragments of inert masses in the form of hemispherical aluminum and soft–steel shells enclosing the spherical charge of a high explosive under their action on flat steel, aluminum, steel–net, and claydite—concrete barriers are given. A design of the lightest spherical explosion–proof container with a load–carrying steel or glass–reinforced plastic shell protected by a splinter–proof layer capable of withstanding an explosion of a high–explosive charge (with a twofold safety factor) with an inert steel shell is proposed.

Results are presented from experimental studies of the influence of the shape and dimensions of the blocks and their orientation relative to the explosive charge on the size and shape of the fragmenting zone, the character of explosive crack formation in the blocks, the structure of the granulometric composition of the destroyed material, and the change in size of the fragments in the crushing zone of a fractured medium when cylindrical explosive charge is exploded.

Small scale explosively driven fragmentation experiments have been performed on Aluminum (Al)-Tungsten (W) granular composite rings processed using cold isostatic compression of Al and W powders with a particle size of 4-30 microns. Fragments collected from the experiments had a maximum size of the order of a few hundred micrometers. This is a dramatic reduction in the fragment size when compared to the 1-10 mm typical for a homogeneous material such as solid aluminum under similar loading conditions. Numerical simulations of the experiment were performed to elucidate the mechanisms of fragmentation that were responsible for this shift in fragmentation size scales. Simulations were performed with a significantly stronger explosive driver to examine how the mechanisms of fragmentation change when the detonation pressure increases.

The concept of social revolution conjures up images of dramatic, fundamental, and enduring political, economic, and cultural change. Yet the comparative study of the actual outcomes of social revolutions work that would lend detail and pattern to such images remains in its infancy. Certainly, most Marxist writing about revolutions, as Michael Walzer has noted, "has focused on the great question: how to get started? What are the causes of revolution? There has been less inter

The longitudinal-momentum distributions of projectile fragments from 0.8 A GeV136Xe and 1 A GeV197Au projectiles impinging on targets of beryllium and aluminium, respectively, have been measured using the projectile-fragment separator FRS at GSI. Different momentum distributions have been found for two different classes of fragmentation processes: the abundant hot fragmentation with several nucleons evaporated from the prefragments, and the rare cold fragmentation with only protons removed from the projectile, but no nucleons evaporated. The data are compared to model calculations.

When the Magnitogorsk Metallurgical Combine began to make cast-iron rolls with a chill layer, it became necessary to break up the rolls after they had been removed from service. The rolls had to be divided into pieces no larger than 600 • 800 mm in order to be used as a component of the metallic charge for the production of alloyed cast iron in arc furnaces or induction furnaces. The combine conducted an experiment in which the rolls were broken up by two technologies already in use at the combine explosive fragmentation, with the blastholes for the explosive charges being perpendicular to the axis of the roll; breakup of the rolls on an impact breaker. The first method posed the danger of having fragments of the chill layer fly off as the blastholes were being drilled. In the second method, the body of the roll could not be broken up into pieces of the required dimensions, and the ball-weight of the impact breaker would itself be broken due to the high hardness of the body. Thus, two new technologies were proposed and tried out for breaking up two-layer cast-iron rolls explosive fragmentation in which the blastholes are located along the body of the roll; the use of an impact breaker after the roll body has been heated by a powerful mechanical cutter in the area where the roll is supposed to be divided. Explosive fragmentation with axial blastholes was chosen as the main technology after tests (two opposing blastholes are used). To perform a comparative analysis, nine rolls were broken up by the proposed fragmentation technology (A) and one was broken up by the existing technology (B). The results (in terms of one roll) are shown below