Beyond equilibrium climate sensitivity

ISSN:1752-0908ISSN:1752-089

Impact energy of everyday items used for assault

Blunt force is a frequently used type of violence especially because it can be performed with basically every object of our daily lives or with bare hands or feet. The injuries and medical consequences have been widely examined, whereas the forces and especially the energies acting on impact have rarely been analyzed. The aim of the present study is to provide the impact energy and its ranges of four longish everyday items with different characteristics for male and female offenders. Additionally, the moment of inertia (MOI) for all the objects was calculated and its influence on the energy determined. A combination wrench, aluminum pipe, golf club, and spade were chosen as representatives of the four categories short, medium length with the center of mass (COM) in the middle, medium length with the COM close to the hitting point, and long and heavy. A total of 880 strikes have been performed by 11 volunteers. The results show the mean energy values of wrench, pipe, golf club, and spade for men of 51.1, 74.4, 93.5, and 166.7 J. For women, the results are 33.0, 41.0, 56.5, and 76.8 J. Knowing the energy thresholds for certain fractures and injuries, these results help to assess whether a claimed hit may have caused the fracture or injury or not

Influence of a soft tissue layer covering the kidney upon blunt impact

Blunt abdominal organ injury is an abundant and relevant topic in forensic medicine, yet comparatively few experimental studies have been performed to quantify organ injury threshold parameters. The goal of this study was to relate an impact to a kidney injury determining an energy threshold while taking account of the influence of the overlaying soft tissue thickness. A model consisting of ballistic gelatin with an embedded filled porcine kidney was made such that a gelatin layer of 2 or 4 cm thickness covered the organ. An impactor was dropped on this model from different heights and the resulting organ damage was categorized according to the abbreviated injury scale (AIS). The 50% energy threshold for damage and the 50% energy threshold causing injuries ≥ AIS 3 were determined for the two protecting soft layers to be 22 J and 32 J and 27 J and 36 J, respectively. A finite element model was created to determine the strain energy densities at the depth of the organ's surface for these energies. The strain energy densities for the 50% damage thresholds were 88.9 mJ/cm3 and 86.7 mJ/cm3 for 2 and 4 cm and for the injuries ≥ AIS 3104.2 mJ/cm3 and 98.7 mJ/cm3. For forensic cases, this means that the thickness of the abdominal layers must be taken into account when the severity of an injury is used to draw conclusions about the applied impact strength

Physik vor Gericht. Die forensische Physik am Institut für Rechtsmedizin der Universität Bern

Die Physik ist als Teil der exakten Wissenschaften objektiv und beschreibt alle in unserer Umwelt vorkommenden Ereignisse und ist deshalb als „neutrale Zeugin“ vor Gericht von zunehmender Bedeutung. Die forensische Physik beschäftigt sich wie die Physik allgemein mit Fragen zu den Gesetzmäßigkeiten der Natur und basiert auf der mathematischen Beschreibung von Ursache und Wirkung. Sie beantwortet u. a. Fragestellungen aus dem Bereich der Justiz, wobei das Augenmerk auf mechanische Einwirkungen auf Strukturen des menschlichen Körpers gerichtet wird. Dabei beschränkt sie sich hauptsächlich auf stumpfe und scharfe Gewalteinwirkung, wobei erstere den Sturz mit einschließt. Geschosse, die bekanntlich auch mechanisch auf den Körper einwirken, werden in der forensischen Ballistik bearbeitet. Die physikalischen Gesetze und das Wissen aus der forensischen Physik werden genutzt, um Tathergänge zu rekonstruieren, Gewalteinwirkungen – auch potenzielle – nach ihrer Gefährlichkeit zu beurteilen und um Zeugenaussagen auf ihre Vereinbarkeit mit den physikalischen Gesetzen zu prüfen

Der Knallfall; Knalldruckmessungen in der Forensik

Beim Gebrauch von Schusswaffen, welche im Rahmen von Straftaten und Delikten ihre Verwendung finden, kommt es, wie der vorliegende Fall zeigt, neben der Gefährdung durch das Geschoss oder den Gasstrahl (Schreckschusswaffen) selbst, zu einer akustischen Belastung, durch die das Gehör irreversibel geschädigt werden kann. Im Rahmen eines versuchten Brandanschlags mit nachfolgender Flucht vor der Polizei, kam es bei der Stellung des Tatverdächtigen zum Gebrauch einer Schreckschusswaffe vom Modell Colt Government 1911 im Kaliber 9 mm PA Knall, welche von diesem, nach der Aufforderung durch die Polizei sich auszuweisen, in einer Distanz von höchstens einem Meter zu einem der Polizeibeamten abgefeuert wurde. Neben den von der zuständigen Staatsanwaltschaft gestellten Fragen zum Gefahrenpotenzial des Gasstrahls dieser Waffe beim Abfeuern, wurde die Frage nach der Möglichkeit der Entstehung eines Gehörschadens infolge des lauten Knalls selbst gestellt

The influence of striking object characteristics on the impact energy.

A common form of violence investigated in legal medicine is blunt trauma caused by striking with different objects. The injuries and medical consequences have been widely examined, whereas the forces and especially the energies acting on impact have rarely been analyzed. This study focuses on how the impact energy of different striking objects depends on their characteristics. A total of 1170 measurements of horizontal strikes against a static and relatively heavy pendulum have been acquired with 13 volunteers. The main focus was laid on how the weight, the length, and the center of mass of the different striking objects influenced the striking energy. The results show average impact energies in the range of 67.3 up to 311.5 J for men with an optimum weight of about 1.3 kg with its center of mass in the far end quarter for a 1-m-long striking object. The average values for women range from 30 to 202.6 J, with an optimum weight between 1.65 and 2.2 kg and similar settings for the center of mass as the men. Also, the impact energies are getting higher with shorter object lengths and reach a maximum at a length of about 0.3 to 0.4 m. The male volunteers' impact energy was on average by 84.2 % higher than the values of the female volunteers, where the impact masses were very similar and the impact velocities played the key role

[Aiming at the chest, but hitting the back]

Gunshot injuries in the back may suggest the unjustified use of firearms. A wound in the back inflicted by a firearm should not automatically imply that the shooter aimed at the back. A previous study demonstrated that it is possible for men to turn their trunk faster than it takes for a shooter to fire or throw a hand-operated weapon. With a high speed motion camera the authors were able to demonstrate that it is also possible for women to turn their trunk fast enough, so that a shot in the back could have been aimed at the front of the body. This conclusion is also likely to apply to hand-operated or thrown weapons, since the velocity of their projectiles is considerably lower than that of firearms