Determining Entrance-Exit Gunshot Holes on Skulls: A Real Time and In situ Measurement Method

Currently, determination of an entrance or exit hole/wound on a skull is largely based on the word description issued by a medical examiner or a forensic pathologist in an autopsy report. Such description is an approximate dimension with rulers (plastic or paper) placed next to the bullet holes, lacking specific quantitative measurements due to the small size of bullet holes and available devices. In this study, a novel technique, namely a digital viewer, is utilized to measure the common characteristics of the entrance/exit holes, providing a more objective description. Using a quasi-experimental design, a simulated skull with an entrance and an exit hole is used to perform the linear, triangular, and circular measurements, producing real time measurements and near 3D images of gunshot holes on a skull at an in situ position. As a result, a more objective and accurate image is obtained for a more scientific entrance-exit gunshot holes determination

Distributed Optimal Frequency Control Considering a Nonlinear Network-Preserving Model

This paper addresses the distributed optimal frequency control of power systems considering a network-preserving model with nonlinear power flows and excitation voltage dynamics. Salient features of the proposed distributed control strategy are fourfold: i) nonlinearity is considered to cope with large disturbances; ii) only a part of generators are controllable; iii) no load measurement is required; iv) communication connectivity is required only for the controllable generators. To this end, benefiting from the concept of 'virtual load demand', we first design the distributed controller for the controllable generators by leveraging the primal-dual decomposition technique. We then propose a method to estimate the virtual load demand of each controllable generator based on local frequencies. We derive incremental passivity conditions for the uncontrollable generators. Finally, we prove that the closed-loop system is asymptotically stable and its equilibrium attains the optimal solution to the associated economic dispatch problem. Simulations, including small and large-disturbance scenarios, are carried on the New England system, demonstrating the effectiveness of our design

Ground Waving and Its Damaging Effect

Some unusual patterns of earthquake damages due to ground waving have been described in order to draw attention to further research towards these problems. A brief introduction of relevant theoretical approach to torsional components of ground motion and amplification of seismic surface waves due to local topographic irregularities have been given in this paper to provide a contrast between theoretical approach and practical cases in order to reflect the gap to be filled

Polarisation of high-energy emission in a pulsar striped wind

Recent observations of the polarisation of the optical pulses from the Crab pulsar motivated detailed comparative studies of the emission predicted by the polar cap, the outer gap and the two-pole caustics models. In this work, we study the polarisation properties of the synchrotron emission emanating from the striped wind model. We use an explicit asymptotic solution for the large-scale field structure related to the oblique split monopole and valid for the case of an ultra-relativistic plasma. This is combined with a crude model for the emissivity of the striped wind and of the magnetic field within the dissipating stripes themselves. We calculate the polarisation properties of the high-energy pulsed emission and compare our results with optical observations of the Crab pulsar. The resulting radiation is linearly polarised. In the off-pulse region, the electric vector lies in the direction of the projection on the sky of the rotation axis of the pulsar, in good agreement with the data. Other properties such as a reduced degree of polarisation and a characteristic sweep of the polarisation angle within the pulses are also reproduced.Comment: Proceedings of the 363. WE-Heraeus Seminar on: Neutron Stars and Pulsars (Posters and contributed talks) Physikzentrum Bad Honnef, Germany, May.14-19, 2006, eds. W.Becker, H.H.Huang, MPE Report 291, pp.108-11

Seismic Effect Evaluation for Underground Space & Structures

It is stressed in this paper that in a strong earthquake the damages of all the underground structures, chambers or any sort of underground space differed quite a lot from that on the ground surface. Numerous evidences show ground motion attenuates immensely downward with depth. However, the earthquake resistance design for underground structures still ignores this fact and sticks to the criteria of ground structures. As a result, very conservative and exhausting design for underground engineering were caused. Through a series of investigations and based on the comparison between the ground damages and the underground damages of the same site, the authors tried to establish an empirical relationship among the predicted intensity/acceleration for aseismic design, the lithology of ambient strata, depth of embedment and the geometry {width/height ratio) of the underground space/structure. As a conclusion, this paper gives a clear picture of how different the underground damages would be from the ground surface and to what range the ground movement would change due to the existence of underground space directly underneath. This approach might be useful for modifying the criteria of a design earthquake for either ground or underground construction

Estimating Maximum Water Absorption of Wood Fiber/Polymer Fluff Composites

The objective of this study was to develop a model to estimate the maximum water absorption (MWA) of wood fiber/polymer fluff composites as a function of polymer fluff content and board density. Polymeric diphenylmethane diisocyanate (PMDI) resin bonded dry-process wood fiber/polymer fluff composites were used in this study. Six polymer fluff contents (0, 15, 30, 45, 60, and 100%) and four target oven-dry board densities in the range of 0.50-1.00 g/cm3 were studied. A water immersion test was conducted on these boards. The effect of irreversible thickness swelling after water immersion (TSi) on the estimation of the maximum water absorption was evaluated. It was shown that the irreversible thickness swelling had a quadratic relationship with polymer fluff content and a linear relationship with oven-dry board density. The TSi of the composites used in this study was in the range of only 0.04-4.20%, which was negligible in the estimation of maximum water absorption. The prediction of maximum water absorption from the MWA model developed in this study was over 95% accuracy for most of the specimens. The maximum water absorption had a linear relationship with the polymer fluff content and a reciprocal relationship with board density

Continuous ASL perfusion fMRI investigation of higher cognition: Quantification of tonic CBF changes during sustained attention and working memory tasks

Arterial spin labeling (ASL) perfusion fMRI is an emerging method in clinical neuroimaging. Its non-invasiveness, absence of low frequency noise, and ability to quantify the absolute level of cerebral blood flow (CBF) make the method ideal for longitudinal designs or low frequency paradigms. Despite the usefulness in the study of cognitive dysfunctions in clinical populations, perfusion activation studies to date have been conducted for simple sensorimotor paradigms or with single-slice acquisition, mainly due to technical challenges. Using our recently developed amplitude-modulated continuous ASL (CASL) perfusion fMRI protocol, we assessed the feasibility of a higher level cognitive activation study in twelve healthy subjects. Taking advantage of the ASL noise properties, we were able to study tonic CBF changes during uninterrupted 6-min continuous performance of working memory and sustained attention tasks. For the visual sustained attention task, regional CBF increases (6–12 ml/100 g/min) were detected in the right middle frontal gyrus, the bilateral occipital gyri, and the anterior cingulate/medial frontal gyri. During the 2-back working memory task, significantly increased activations (7–11 ml/100 g/min) were found in the left inferior frontal/precentral gyri, the left inferior parietal lobule, the anterior cingulate/medial frontal gyri, and the left occipital gyrus. Locations of activated and deactivated areas largely concur with previous PET and BOLD fMRI studies utilizing similar paradigms. These results demonstrate that CASL perfusion fMRI can be successfully utilized for the investigation of the tonic CBF changes associated with high level cognitive operations. Increased applications of the method to the investigation of cognitively impaired populations are expected to follow

The Critical Role of Public Charging Infrastructure

Editors: Peter Fox-Penner, PhD, Z. Justin Ren, PhD, David O. JermainA decade after the launch of the contemporary global electric vehicle (EV) market, most cities face a major challenge preparing for rising EV demand. Some cities, and the leaders who shape them, are meeting and even leading demand for EV infrastructure. This book aggregates deep, groundbreaking research in the areas of urban EV deployment for city managers, private developers, urban planners, and utilities who want to understand and lead change