Wind Channel Research Articles

Wound ballistics of military rifle bullets: An update on controversial issues and associated misconceptions.

The wound ballistics literature contains several misconceptions about the physical effects of penetrating projectiles in tissue and tissue simulants. These can adversely affect the proper management of gunshot injuries, particularly in view of the ongoing threat of terrorist and criminal acts using assault rifles against civilians. The understanding of the wounding effects by military rifle bullets can be founded on the concept of energy transfer to the wound as applied to high-energy missile trauma. A substantial component of high-energy transfer in assault rifle injuries is manifested by the dynamic phenomenon of temporary cavitation, which is extensively reviewed with respect to its impact on the wound production and the associated controversy surrounding its consequences in soft tissue wounds. Part of this controversy emanates from misinterpretation of experimental data regarding the magnitude of the temporary cavity induced by high-velocity projectiles and the different conceptions of the tissue response to cavitation. The interaction between the projectile and tissue can lead to tumbling and possibly to deformation and fragmentation of the bullet, all of which strongly influence the energy transfer characteristics affecting both the temporary cavitation and the size of the permanent wound channel. Awareness of these effects can enhance perception of clinical and radiological findings suggestive of the wounding mechanism by various projectiles. LEVEL OF EVIDENCE: Review/therapeutic, level V.

Fragmentation of lead-free and lead-based hunting rifle bullets under real life hunting conditions in Germany.

As lead is a heavy metal showing high toxicity for many organisms, its entry in the ecosystem should be minimised. Nevertheless, considerable quantities are deposited in the environment via hunting ammunition. Such practice is responsible for the occurrence of lead poisoning in many wildlife species and represents a health risk to humans. We assess the differences in the fragmentation patterns of lead-based and lead-free hunting rifle bullets using the radiographic characteristics of gunshot wounds. We took radiographs of 297 wild ungulates shot during regular hunting events in Germany. Compared to lead-free ammunition, both the number of bullet fragments and the maximal distance between fragments and the wound channel increased when bullets were lead-based. Under normal German hunting conditions, the use of lead-based bullets causes a broad contamination of the carcass and the viscera with bullet material. The wide-spread substitution of lead-based bullets through non-lead alternatives should therefore be further encouraged.

Risk Assessment of Lead Exposure from Cervid Meat in Norwegian Consumers and in Hunting Dogs

Risk Assessment of Lead Exposure from Cervid Meat in Norwegian Consumers and in Hunting Dogs

Forensic, clinical and anatomical aspects of diagnosising diaphragmatic injuries in stab wounds

To improve the quality of clinical and forensic examination and diagnosis of diaphragmatic injury (DI) from stab wounds by defining the boundaries of the thoraco-abdominal region and the topographic and anatomical characteristics of thoracoabdominal stab wounds. Based on the results of forensic medical examinations of 81 corpses with stab wounds, the clinical and anatomical characteristics of thoraco-abdominal stab wounds were noted; and in anatomical dissections of 90 cadavers, the boundaries of the intercostal spaces and costophrenic recess were modeled. The boundaries of the thoraco-abdominal region, and the location of stab wounds that make the probability of DI particularly high (10-50%) were clarified. A method for diagnosing DI was developed. The method was used to identify DI in 81 out of 411 victims with penetrating stab wounds to the chest and abdomen. The results of the study prove the feasibility of using computed tomography in the examination of living persons with a wound in the thoracoabdominal region. This study can assist in determining the features of a wound channel, in providing a correct assessment of the damage, and in the identification of undiagnosed DI.

Designing public squares with green infrastructure to optimize human thermal comfort

People living in cities are experiencing summerly heat stress situations with severe consequences for their health, especially under climate change. Urban planning needs to address this problem focusing on areas where people are exposed to heat such as in public squares. Typical square designs include green infrastructure which can positively affect outdoor thermal comfort by providing regulating ecosystem services, but knowledge on the effectiveness of different design approaches is still limited. The present study assessed typical greening designs of rectangular public squares and their microclimatic influences during a hot summer day both during day and night-time conditions. By using a validated ENVI-met V4 model, thermal comfort values expressed by the physiologically equivalent temperature (PET) index were compared. Moreover, a novel greening design was developed and tested with the model. The results showed that at 3pm the greening design with most trees and trees placed in the sunlit areas of the square provided 5.2% higher cooling effect compared to the current greening, whereas for 4am the design without trees, but with meadow areas performed best (4.2% heat reduction). This led to the conclusion that for a comfortable thermal situation a climate adapted design has to include trees to maximize the shaded surface areas, while the main wind channel is kept free from trees, but planted with grass to minimize the heat storage. The number of trees and their placement together with the extent and placement of grass areas can thus serve as indicators for designing climate adapted public squares.

SAND WAVE EVOLUTION MODEL FOR EFFICIENT CHANNEL DEPTH MANAGEMENT

Sand wave is a consecutive wavy bedform on seabed with several meters in wave height and several tens-hundreds of meters in wave length. If the crests of sand waves rise above the required channel depth, they often prevent vessels from safe navigation. In this study, a prediction model of sand wave evolution is applied to predict depth change at the crest of sand waves in Kanmon route, Japan. Kanmon route is a long, narrow and winding channel where strong tidal currents take place due to large tidal difference between Japan sea and Seto-island sea. In these area, a lot of bathymetric survey data have been collected to monitor the water depth. Also, channel deepening project up to -14 m is underway, and therefore reliable prediction model of sand wave evolution is needed for channel depth management in the future.

Comparison of lead levels in edible parts of red deer hunted with lead or non-lead ammunition

Game meat may contain elevated concentrations of lead especially if lead-containing ammunition is used for hunting. Then a health risk is possible for consumer groups with high game meat intake.The lead concentrations in three edible parts (marketable meat from the area close to the wound channel, saddle and haunch) of meat from red deer (Cervus elaphus) between animals hunted either with lead or non‑lead ammunition were compared. Furthermore, lead levels in game meat of lead-shot red deer were compared with those of lead-shot roe deer and lead-shot wild boar.Ninety red deer were shot and killed in the context of this study (64 with lead and 26 with non‑lead ammunition). Since the lead concentration for a number of the samples was below the limit of detection or the limit of quantification, statistical methods for left-censored data were applied.The median concentrations of lead in game meat did not differ significantly between lead shot and non‑lead shot animals. However, when we analyzed the more elevated lead concentrations, they were significantly higher in edible parts of animals shot with lead ammunition than non-lead ammunition. The highest concentrations were found in samples from edible meat from the area close to the wound channel (max 3442 mg Pb/kg), followed by the saddle (max 1.14 mg Pb/kg) and with the lowest levels in the haunch (max 0.09 mg Pb/kg). A comparison of game species revealed that the lead concentration in haunch and saddle of lead shot red deer was higher than in the corresponding samples of lead shot roe deer.Our results have shown that by the use of non-lead ammunition, a significant reduction of the lead concentration especially in edible parts near the wound channel is possible.

Rifle bullet deflection through a soft tissue simulant

Trajectory deflections of 5.56 NATO and 7.62×39mm rifle bullets, fired through 7.5, 15 and 22.5cm of gelatine, were studied. The magnitude of the deflections from the bullets’ original trajectories after perforation are related to the length and the profile of the (wound) channels through gelatine. After 7.5cm of penetration depth, deflection was less than 1°. With the longer channel lengths, bullet instability set in and subsequently, deflection was much larger. Deflection was highest with fragmented 5.56 NATO bullets after perforating 22.5cm of gelatine. The data from this study can be used to assess the degree of bullet deflection in trajectory reconstructions after incidents where human bodies were perforated with rifle bullets of the respective calibres and cartridge types.

Postmortem computed tomography and autopsy for detection of lesions and causes of death in gunshot injury cases: a comparative study

BackgroundFirearm injuries are a common cause of death in cases typically investigated by medical examiners. Postmortem multislice computed tomography (PMCT) provides valuable information that enhances the autopsy examination. This study was conducted to compare PMCT and autopsy for the detection of injuries and causes of death in cases of fatal firearm injuries. Thirty cadavers were scanned with PMCT and then underwent autopsy. The results of the two techniques were compared regarding entry wounds, wound channels, detection of foreign bodies, organ and skeletal injuries, and causes of death to determine the concordance or discordance between the two techniques.ResultsThe results revealed excellent agreement between PMCT and autopsy for the detection of injuries and causes of death in cases of gunshot injury. Furthermore, PMCT revealed injuries such as pneumothorax and surgical emphysema that were found to be undetermined by autopsies where the special dissection technique was not part of our routine procedures.ConclusionPMCT could be a valuable complementary tool for autopsies to determine and localize injuries and causes of death in cases of gunshot injury.

Temporal Regulation of the Bacterial Metabolite Deoxycholate during Colonic Repair Is Critical for Crypt Regeneration

Colonic wound repair is an orchestrated process, beginning with barrier re-establishment and followed by wound channel formation and crypt regeneration. Elevated levels of prostaglandin E2 (PGE2) promotebarrier re-establishment; however, we found that persistently elevated PGE2 hinders subsequent repair phases. The bacterial metabolite deoxycholate (DCA) promotes transition through repair phases via PGE2 regulation. During barrier re-establishment, DCA levels are locally diminished in the wound, allowing enhanced PGE2 production and barrier re-establishment. However, during transition to the wound channel formation phase, DCA levels increase to inhibit PGE2 production and promote crypt regeneration. Altering DCA levels via antibiotic treatment enhances PGE2 levels but impairs wound repair, which is rescued with DCA treatment. DCA acts via its receptor, farnesoid X receptor, to inhibit the enzyme cPLA2 required for PGE2 synthesis. Thus, colonic wound repair requires temporally regulated signals from microbial metabolites to coordinate host-associated signaling cascades. VIDEO ABSTRACT.

Irradiance fluctuations of an indoor FSO channel based on hot air chambers

In this paper the fourth order statistical momentum behavior of irradiance fluctuations through hot air chambers which is crucial for evaluating the proper performance of optical turbulence generator (OTG) as a laser communication channel is studied. Basic principles of designing a developed free space optical wave propagation channel are presented. In order to validate the OTG performance with respect to the real atmosphere, beside Kolmogrov statistics presumptions like homogeneity, isotropy, stationarity and ergodicity, random fluctuations of the signal due to atmospheric turbulence is investigated and compared with log-normal and gamma-gamma PDF model. We have shown the above properties for our OTG and 2/3 power law behavior for the temperature structure function according to the Kolmogrov theory. Experimental data of irradiance fluctuations are well corresponds to the log-normal and gamma-gamma distributions under proper wind velocities and chamber active area. Therefore the chamber irradiance fluctuations resemble more accurately to the real atmosphere. Atmospheric parameters of the turbulence in different wind speeds and channel widths are estimated by new method of fitting the theoretical PDF to the experimental intensity irradiance distribution. The irradiance fluctuations again temperature difference and turbulence strength is measured and compared with the theory.

Pistol bullet deflection through soft tissue simulants

Trajectory deflections of pistol bullets from four different firearms, fired through soft tissue simulants under two different incidence and exit angles were studied. The data from this study can be used in reconstructions of shooting incidents where human soft tissues (not bones) were perforated with pistol bullets and assumptions must be made about bullet deflection in order to correctly reconstruct trajectories. The results demonstrate that deflection was influenced by the length of the “wound channel” through the simulants. In short, deflection was small to virtually absent with 5 and 10cm channel lengths. With channel lengths of 15, 20 and 25cm, there was a clear increase in deflection and/or a more erratic deflection behaviour with most shots. The data also suggest an influence of the angle of incidence and/or exit on both the direction and the magnitude of the deflection.

The Impact of Vegetation on Thermal Performance

This paper investigates the effect of vegetation in modifying outdoor temperature around a single-family house in a hot and humid tropical climate. The climatic parameters, house location, and physical characteristics of landscape design are measured and surveyed. The focus of this study is on the impact of trees and different types of foliage on the thermal environment of the houses. The main findings are that heavily landscape around single-family houses can potentially slow heat build-up by shading, evapotranspiration, and wind channelling by as much as 4°C.Keywords: Single-family house, thermal performance, landscape design, evapotranspirationeISSN 2398-4295 © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. http://dx.doi.org/10.21834/ajbes.v3i11.110

Adaptive stitching for meso-scale printing with two-photon lithography

An inevitable trade-off between resolution and total size exists when 3D printing objects. This is also the case for two-photon or multi-photon lithography. While it is capable of reaching a sub-micron feature size, it needs to combine a high precision movement mechanism with a lower precision one when writing centimetric size objects. As a result, the final part consists of a combination of many individual blocks, where the overlapping areas often create bumps and imperfections in the final object. In the current contribution, we demonstrate how an adaptive stitching algorithm can lead to a reduction in the total amount of stitching blocks of up to 40% for slender objects (i.e. with features smaller than the individual block size). As is demonstrated on a winding microfluidic channel, this can lead to substantial manufacturing time gains of up to 25%. As our tiling is irregular, we also explain how to create the writing masks for the blocks and decide on their order. In the special case in which one does not need to print one single large continuous part, but rather many individual ones (such as a microlens array), we demonstrate how zero-overlap stitching can be achieved with a modified version of our adaptive algorithm.

IDENTIFICATION OF THE AUTOMATIC GRENADE LAUNCHERʼS AMMUNITION AGS-17 FOR THE MORPHOLOGICAL CHARACTER OF DAMAGES AND SHRAPNELS FROM THE COPSES AFTER FORENSIC MEDICAL EXAMINATION

. The publication is devoted to an actual problem - postmortem diagnostics an explosive trauma. The work presents the features of body injuries, the contents of wound channels in the explosions of the fragmentation grenade VOG-17M. The obtained data allow identification of an explosive device and conduct differential diagnostics with the operation of other explosive ordnance.

Manufacture and impact analysis of bmx helmet made from polymeric foam composite strengthened by oil palm empty fruit bunch fiber

Helmets are protective head gears wear by bicycle riders for protection against injury in case of the accident. Helmet standards require helmets to be tested with a simple drop test onto an anvil. The purpose of research is to know toughness of bicycle helmet made from polymeric foam composite strengthened by oil palm empty fruit bunch fiber. This research contains report result manufacture and impacts analysis of bicycle helmet made from polymeric foam composite materials strengthened by oil palm empty fruit bunch fiber (EFB). The geometric helmet structure consists of shell and liner; both layers have sandwich structure. The shell uses matrix unsaturated Polyester BQTN-157EX material, chopped strand mat 300 glass fiber reinforce and methyl ethyl ketone peroxide (MEKPO) catalyst with the weight composition of 100 gr, 15 gr, and 5 gr. The liner uses matrix unsaturated Polyester BQTN-157 EX material, EFB fiber reinforces, Polyurethane blowing agent, and MEKPO catalyst with the composition of 275 gr (50%), 27.5 gr (5%), 247 gr (45%), and 27.5 gr (5%). Layers of the helmet made by using hand lay-up method and gravity casting method. Mechanical properties of polymeric foam were the tensile strength (ơt) 1.17 Mpa, compressive strength (ơc) 0.51 MPa, bending strength (ơb) 3.94 MPa, elasticity modulus (E) 37.97 Mpa, density (ρ) 193 (kg/m3). M4A model helmet is the most ergonomic with the thickness 10 mm and the amount of air channel 11. Free fall impact test was done in 9 samples with the thickness of 10 mm with the height of 1.5 m. The result of the impact test was impacted force (Fi) 241.55 N, Impulse (I) 6.28 Ns, impact Strength (ơi) 2.02 Mpa and impact Energy (Ei) 283.77 Joule. The properties of bicycle helmet model BMX-M4A type was 264 mm length, 184 mm width, 154 mm height, 10 mm thick, 580 mm head circle, 331 g mass and 11 wind channels.

Direct enrichment of pathogens from physiological samples of high conductivity and viscosity using H-filter and positive dielectrophoresis.

The full potential of microfluidic techniques as rapid and accurate methods for the detection of disease-causing agents and foodborne pathogens is critically limited by the complex sample preparation process, which commonly comprises the enrichment of bacterial cells to detectable levels. In this manuscript, we describe a microfluidic device which integrates H-filter desalination with positive dielectrophoresis (pDEP) for direct enrichment of bacterial cells from physiological samples of high conductivity and viscosity, such as cow's milk and whole human blood. The device contained a winding channel in which electrolytes in the samples continuously diffused into deionized (DI) water (desalination), while the bacterial cells remained in the samples. The length of the main channel was optimized by numerical simulation and experimentally evaluated by the diffusion of fluorescein into DI water. The effects of another three factors on H-filter desalination were also investigated, including (a) the flow rate ratio between the sample and DI water, (b) sample viscosity, and (c) non-Newtonian fluids. After H-filter desalination, the samples were withdrawn into the dielectrophoresis chamber in which the bacterial cells were captured by pDEP. The feasibility of the device was demonstrated by the direct capture of the bacterial cells in 1× PBS buffer, cow's milk, and whole human blood after H-filter desalination, with the capture efficiencies of 70.7%, 90.0%, and 80.2%, respectively. We believe that this simple method can be easily integrated into portable microfluidic diagnosis devices for rapid and accurate detection of disease-causing agents and foodborne pathogens.

A change in the direction of the wound channel in the case of the combined injury inflicted by a shot from the 9.0 mm Makarov pistol

The authors present an example from the expert practice demonstrating the influence of such factors as the properties of the ammunition fired from a weapon (including its weight, size, shape, and speed) as well as the anatomical features of the body tissues being affected on the mechanism of formation of a gunshot wound in the human body. The investigation of the suicide of subject P. has demonstrated the penetrating bullet wound of the neck and the head. The entrance wound was located at the anterior neck surface and the exit one in the left half of the occipital region. The examination of the cranial bones revealed perforating fractures of the cribriform and occipital bones. A specific feature of the case under consideration was a change in the bullet direction during its passage through the cribriform bone that made up the internal osseous barrier. A result the initially vertical wound canal turned into the horizontal one within the cerebral cranium and looked on the whole like a zigzag line. The present observation confirms the possibility of a marked change in the direction of the bullet's trajectory in the cranial cavity even when a 9.0 mm bullet fired from the Makarov pistol hits a relatively soft internal bone structure.

Post-mortem diagnosis of gunshot injuries in an osprey: A case report

The shooting of protected species, especially rare animals, is regarded as a priority issue by law enforcement authorities. In such cases, an expert veterinarian is required not only to confirm the death of the animal as a result of shooting, but also to provide a precise description of the shot. In cases of shootings with pellet bullets, such a description is particularly difficult. The evaluation of the gunshot wounds of an osprey (Pandion haliaetus) delivered to the Veterinary Medical Centre at the University of Poznań called for the use of a variety of diagnostic techniques. A preliminary assessment confirming the shot was based on an X-ray photo. Computed tomography (CT) was used for in-depth diagnostics, providing a spatial representation of bullet stopping points and fragments. The shot caused a lower leg bone fracture. This damage upset the anatomical structure of the animal's limb, which made it impossible to establish the wound channel by CT. Therefore, full shot characteristics could only be made only after a classical post-mortem examination. This examination facilitated the use of modern imaging diagnostic techniques. The use of mixed diagnostic techniques enabled us to determine the number of shots, the type of ammunition used and the direction from which the shot was fired. On the one hand, this case illustrates the possibilities offered by modern imaging diagnostic techniques and, on the other hand, it shows that the classic post-mortem examination remains a primary diagnostic tool for veterinary forensic experts. This is especially important when preparing forensic veterinary opinions in high-priority law enforcement cases. .

Update on gunshot wounds to extremities

Due to recent rampage and terror attacks in Europe, gunshot wounds have become a focus of attention even though they are still rare in Europe. Approximately 50% of gunshot wounds affect the extremities and to understand the sequelae, abasic knowledge of wound ballistics is indispensable. The energy transmitted from the bullet to the tissue is responsible for the severity of the injury and is dependent on the type of weapon and ammunition. Adifferentiation is made between low-energy injuries caused, e.g. by pistols and high-energy injuries mostly caused by rifles. The higher energy transfer to the tissue in high-energy injuries, results in atemporary wound cavity in addition to the permanent wound channel with extensive soft tissue damage. High-energy gunshot fractures are also more extensive compared to those of low energy injuries. Debridement seems to be necessary for almost all gunshot wounds. Fractures should be temporarily stabilized with an external fixator due to contamination.