A simplified formula to estimate the load history due to ballistic impacts with bullet splash. Development and validation for finite element simulation of 9x21mm full metal jacket bullets

An original simplified formula is proposed to estimate the load history caused by ballistic impacts characterized by the so-called bullet splash phenomenon, consisting in the complete bullet fragmentation with no penetration of the target. The formula is based on the progressive momentum variation of the mass of the bullet impacting on a planar plate normal to the impact direction. The method aims at creating a simplified approach to assess the response of structures by means of explicit finite element simulations without the need of modelling the interaction between impactor and target. The results demonstrate that the proposed method can be used to estimate the forces generated by bullet-splash phenomena of 9x21mm full metal jacket bullets and effectively applied to finite element simulations allowing significant reductions in computational cost

The Digital Life of Walkable Streets

Walkability has many health, environmental, and economic benefits. That is why web and mobile services have been offering ways of computing walkability scores of individual street segments. Those scores are generally computed from survey data and manual counting (of even trees). However, that is costly, owing to the high time, effort, and financial costs. To partly automate the computation of those scores, we explore the possibility of using the social media data of Flickr and Foursquare to automatically identify safe and walkable streets. We find that unsafe streets tend to be photographed during the day, while walkable streets are tagged with walkability-related keywords. These results open up practical opportunities (for, e.g., room booking services, urban route recommenders, and real-estate sites) and have theoretical implications for researchers who might resort to the use social media data to tackle previously unanswered questions in the area of walkability.Comment: 10 pages, 7 figures, Proceedings of International World Wide Web Conference (WWW 2015

A Simplified ALE model for finite element simulation of ballistic impacts with bullet splash – development and experimental validation

An original simplified finite element model is proposed to simulate the effects of non-penetrating ballistic impacts causing the so-called bullet splash phenomenon (complete bullet fragmentation), while no fragmentation is caused to the target. The model is based on the Arbitrary Lagrangian Eulerian formulation (ALE) and it simulates the impact as a fluid-structure interaction. The bullet splash phenomenon has been tested by experimental analyses of AISI 304L plates impacted by 9x21 FMJ (full metal jacket) bullets. The model has been developed with the aim of creating a simplified approach to be used in the industry and forensic sciences to simulate the non-penetrating interaction of soft impactors with hard targets. Comparisons between evidence and simulation results lead to the conclusion that the proposed approach can be used in a conservative way to estimate both local and global effects of bullet-splash phenomena

A simplified constitutive model for a SEBS gel muscle simulant - Development and experimental validation for finite elements simulations of handgun and rifle ballistic impacts

An original simplified constitutive model is proposed to simulate the effects of ballistic impacts on blocks of synthetic muscle simulant based on mineral oil and styrene ethylene-butylene styrene polymers (SEBS) as a convenient substitute for Fackler ballistic gelatin. The model is based on a quasi-static elastic-plastic model associated with hydrodynamic properties regulated by a polynomial equation of state. The paper illustrates the development and experimental validation of the model to simulate 9x21mm FMJ round-nose, 7.62x39 mm FMJ, and 5.56x45 mm NATO bullets penetrating 145x145x400 mm gel blocks. All material parameters are provided to be implemented in built-in LS-Dyna keywords. The validation confirms the effectiveness of the model and suggests possible further developments. The work also confirms the tested synthetic gel as a valid and convenient substitute for Fackler 10% ballistic gelatin at 4 °C

Use of negative pressure wound therapy systems after radical vulvectomy for advanced vulvar cancer

A retrospective cohort study was performed to evaluate the efficacy of negative pressure wound therapy in improving vulvectomy healing. Women who underwent radical vulvectomy with complete inguinofemoral lymphadenectomy for advanced vulvar cancer were divided into two groups according to immediate postoperative care: patients treated with negative pressure wound therapy using the device applied on the site of the wound (including vulva and inguinal region), and patients receiving conventional care. 18 patients were included in the study. 7 (38.9%) women were treated with negative pressure wound therapy immediately after the surgery and were included in the intervention group, and 11 (61.1%) patients were included in the control group. Women who received negative pressure wound therapy had significantly lower length of stay in the hospital (14.2 ± 4.7 versus 17.1 ± 6.1 days, mean difference −6.90 days, 95% confidence interval −11.91 to −1.89), and significantly lower length for wound healing (−31.90 days, 95% confidence interval −43.48 to −20.32). In conclusion, the utilization of the negative wound pressure therapy may contribute to reduce hospitalization after radical vulvectomy for vulvar cancer. Large and well-designed randomized trials with cost effectiveness analyses are needed to confirm these findings

“Because It Kind of Falls in Between, Doesn’t It? Like an Acute Thing and a Chronic”: the Psychological Experience of Anaphylaxis in Adulthood

Anaphylaxis is a serious, rare condition increasing in prevalence. This study explored the psychological experience of adult-onset anaphylaxis from patient, family and staff perspectives. Semi-structured interviews were conducted with twelve participants. Two global themes emerged from thematic analysis: ‘controllability’ (‘an unknown and distressing experience’, ‘the importance of control over triggers’ and ‘responsibility but no control: the impact on others’) and ‘conflict’ (‘rejecting illness identity’, ‘minimisation of risk’, ‘accessing specialist care: running in slow motion’ and ‘patient-centred versus service-centred care’). Findings highlight the importance of perceived control and emphasise the presence of conflict in the experience of this complex, episodic condition

Assessment of New Ex-Vessel Magnetic Measurements in JET

ABSTRACT. A new ex vessel magnetic diagnostics was installed in JET during 2005 shut down, with the objective of: i) provide experimental data for a better modelling of the iron in the axisymmetric codes for plasma equilibrium reconstruction; ii) test the reliability of direct field measurements from Hall probes. The latter are of great interest for future ITER-like devices, where long lasting flat top phases are expected, in a high neutron yield and a high temperature environment. The experimental data achieved during the restart phase were analysed with the aid of simulation codes. Each individual signal was assessed for inclusion in the general JET Diagnostics system. The system is ready for use in the 2006 experimental campaigns