Ballistic skin simulant

Hydrogels prepared from water solutions containing 10-20 mass% gelatine are generally accepted muscle tissue simulants in terminal ballistic research. They, however, do not have a surface layer which simulates the effect of human skin. The purpose of this research was to find a suitable skin simulant for enhancing the testing fidelity and the credibility of the results with gelatine-based materials when assessing the injury potential of not only high energy bullets, but also especially that of non-penetrating "less lethal" kinetic impact ammunition and relatively low energy ricochet fragments. A skin simulant also permits the simulation and assessment of exit wounds. The mechanical and ballistic properties of human skin and target simulant were established on the basis of results found in the literature. Some errors in these were found. The corrected values are included in this paper for comparison. The target values of the mechanical properties of the skin simulant were the following: threshold velocity v(th)=94+/-4 m/s, tensile strength 18+/-2 N/mm2 and elongation at break 65+/-5%. A selection of synthetic and natural materials was evaluated as skin simulants by analysing their mechanical and ballistic properties. The results were compared to literature values obtained with human cadavers. The tests showed that the best skin simulant of the ones evaluated was semi-finished chrome tanned upholstery "crust" cowhide of 0.9-1.1 mm nominal thickness. Its threshold velocity was 90.7 m/s, tensile strength 20.89+/-4.11 MPa and elongation at break 61+/-9%. These values are the same as the average values of human skin. Of the synthetic materials evaluated, 1mm thick natural rubber can be used on impact side as a threshold velocity filter with some reservations although its theoretical threshold velocity is only 82.9 m/s.     

Deducing drop size and impact velocity from circular bloodstains

An experimental study was done to determine the diameter and velocity of blood drops falling on a surface by measuring the size of bloodstains they produced and counting the number of radial spines projecting from them. Bloodstains were formed by releasing drops of pig blood with a range of diameters (3.0-4.3 mm) and impact velocities (2.4-4.9 m/s), onto four different flat surfaces (glass, steel, plastic, paper) with varying roughness (0.03-2.9 microm). High-speed photography was used to record drop impact dynamics. Bloodstain diameters and the number of spines formed around the rim of stains increased with impact velocity and drop diameter. Increasing surface roughness reduced stain diameter and promoted merging of spines, diminishing their number. Equations are presented that explicitly relate drop diameter and impact velocity to measurements of stain diameter and number of spines.     

钝力冲击后心脏组织形态学变化的实验研究

本研究用自制机械式弹性拉力打击器以６．７ｍ／ｓ、８．０ｍ／ｓ、９．１ｍ／ｓ及１０．０ｍ／ｓ速度冲击大胸骨心前区，然后采用多种组织学染色及透射电镜技术对心脏组织形态学变化进行了观察。结果表明：①以６．７ｍ／ｓ及８．０ｍ／ｓ速度冲击后心脏宏观未见有明显改变，微观可见心肌波浪变。电镜下可见肌原纤维肌节收缩，Ｉ带消失或轻度Ｉ带增宽乃至肌原纤维断裂。②以９．１ｍ／ｓ及１０．０ｍ／ｓ速度冲击后宏观可见心脏挫伤，微观心肌挫伤改变明显，实验观察６０ｍｉｎ内心肌血管内皮损伤处已有血小板粘附集聚甚至血栓形成，心肌超微结构损害严重。③同一心脏可有多部位损伤，且损伤程度不均一。本研究进一步表明钝力性心脏外伤中．虽然无宏观损伤所见，其微观，特别是超微结构可有损害。     

A blind trial evaluation of a crime scene methodology for deducing impact velocity and droplet size from circular bloodstains

In a previous study, mechanical engineering models were utilized to deduce impact velocity and droplet volume of circular bloodstains by measuring stain diameter and counting spines radiating from their outer edge. A blind trial study was subsequently undertaken to evaluate the accuracy of this technique, using an applied, crime scene methodology. Calculations from bloodstains produced on paper, drywall, and wood were used to derive surface-specific equations to predict 39 unknown mock crime scene bloodstains created over a range of impact velocities (2.2-5.7 m/sec) and droplet volumes (12-45 microL). Strong correlations were found between expected and observed results, with correlation coefficients ranging between 0.83 and 0.99. The 95% confidence limit associated with predictions of impact velocity and droplet volume was calculated for paper (0.28 m/sec, 1.7 microL), drywall (0.37 m/sec, 1.7 microL), and wood (0.65 m/sec, 5.2 microL).     

圆形滴状血迹形态与血滴体积、撞击速度的相关性

目的观察不同体积的血滴以3种撞击速度垂直撞击3种不同介质形成的滴状血迹形态及大小,并探讨其相关性。方法将8种不同体积（14～115IxL）的抗凝猪m形成血滴,以3种不同的撞击速度（3．1～5．4m／s）分别垂直滴落于白纸、玻璃及釉面地砖上,观察形成血迹的形态特征,测量其直径,并采用SPSS13．0统计软件进行分析。结果在3种撞击速度条件下,在3种介质上形成的滴状血迹直径均随血滴体积的增加而增大,血迹直径与血滴体积存在较好的线性关系,可得出回归方程（回归模型R2〉0．85,P〈0．01）;介质表面越粗糙,血迹直径越小;仅在自纸上发现血迹边缘有突起形成,且其数目随血滴体积的增加而增多。撞击速度及血滴体积存在较好的多重线性关系,可得出多重回归方程（回归模型R2〉0．90,P〈0．01）。结论垂直撞击形成的血迹形态及大小与血滴体积、撞击速度具有显著的相关性,可望用于推测出血源位置、受伤体位及出血部位载体。     

大鼠骨骼肌钝挫伤分级模型的建立

目的建立一个控制性、重复性好,并可分级的骨骼肌挫伤动物模型。方法采用自行设计的机械式撞击装置,以撞击速度（velocity,v）和形变（deformation,DF）作为外力参数,并保持较恒定的撞击时间,使击锤打击瞬间速度不同,造成轻、中、重不同程度的大鼠腓肠肌挫伤。结果在肉眼、HE染色观察下．39只大鼠腓肠肌出现可分级的病理学改变。在低撞击水平（v：2m／s,DF：5．5mm）,轻度挫伤组病理改变局限于大鼠腓肠肌肌外膜和腓肠肌表层部位;在中度撞击水平（v：2．5m／s,DF：6．5mm）,中度挫伤组病理改变可见于大鼠腓肠肌肌外膜和大部分腓肠肌;在高撞击水平（v：3m／s,DF：7,5mm）,重度挫伤组病理改变除中度挫伤组累及部位外,还伤及比目鱼肌。结论该模型制作出常见的钝力性骨骼肌挫伤,以撞击速度和形变作为外力参数,成功建立了机械骨骼肌挫伤分级模型,致伤程度较一致,是骨骼肌挫伤研究较合适的动物模型,为深入研究钝力性骨骼肌挫伤奠定了基础．     

On the Distinction Between Epistemic and Metaphysical Buddhist Idealisms: A Śaiva Perspective

Modern scholarship has often wondered whether Indian Buddhist idealism is primarily epistemic or metaphysical: does this idealism amount to a kind of transcendental scepticism according to which we cannot decide whether objects exist or not outside of consciousness because we can have no epistemic access whatsoever to these objects? Or is it rather ontologically committed, i.e., does it consist in denying the very existence of the external world? One could deem the question anachronistic and suspect that with such an inquiry we project onto Ancient and Medieval India a distinction that remains profoundly alien to it, were it not for a few preserved texts where Indian authors themselves distinguish between two such kinds of idealism within the Buddhist philosophical tradition. As already pointed out by Dan Arnold, this is the case in the commentary by Manorathanandin on Dharmakīrti’s Pramā?avārttika; but the difference between two varieties of Buddhist idealism is also alluded to in Hindu sources, both Mīmā?saka and ?aiva. The present article offers a new analysis of Manorathanandin’s short and somewhat ambiguous distinction, and it examines in this connection some important remarks found in the works of the ?aiva nondualists Utpaladeva (c. 925–975) and Abhinavagupta (c. 975–1025). It shows that according to these authors, in fact the epistemic version of the Buddhist argument in favour of idealism is already metaphysical insofar as it necessarily involves a denial of the existence of the external world, and it attempts to assess the faithfulness of this ?aiva interpretation to its Buddhist sources.     

Experimental study of the expansion dynamic of 9 mm Parabellum hollow point projectiles in ballistic gelatin

We study in this paper the expanding behaviour of hollow point 9 mm Parabellum projectiles (Hornady XTP(?) and Speer Gold Dot(?)). We defined a deformation rate that takes into account both the diameter increase and the length reduction. We plotted the behaviour of this parameter versus impact velocity (we refer to this curve as the expanding law). This expanding law has been plotted for different gelatin weight ratios and different gelatin block lengths. We completed our experiments with a set of high speed movies in order to correlate the deceleration to the state of expansion and size of the temporary cavity. Our results pointed out that full expansion is reached shortly after the projectile fully penetrates the gelatin. This result shows that the key point to accurately simulate human body interaction with a hollow point projectile is to accurately simulate the interface (skin, skull, clothes thoracic walls). Simulating accurately organs is only an issue if a quantitative comparison between penetration depths is required, but not if we only focus on the state of expansion of the projectile. By varying the gelatin parameters, we discovered that the expanding law exhibits a velocity threshold below which no expansion occurs, followed by a rather linear curve. The parameters of that expanding law (velocity threshold and line slope) vary with the gelatin parameters, but our quantitative results demonstrate that these parameters are not extremely critical. Finally, our experiments demonstrate that the knowledge of the expansion law can be a useful tool to investigate a gunshot in a human body with a semi-jacketed projectile, giving an estimation of the impact velocity and thus the shooting distance.     

实验性心脏挫伤动物模型的建立

本研究应用自制机械式弹性拉力打击器以9．1～10．5m／s速度冲击动物胸骨心前区，不仅导致左右心室压力、心电图及心率发生改变，而且造成了心脏挫伤等宏观的病理形态学变化，成功地建立了心脏挫伤动物模型，为深入研究钝力性心脏外伤奠定了基础。     

Relationship between the concentration of ethanol and methanol in blood samples from Swedish drinking drivers

Headspace gas chromatography was used to determine the concentration of ethanol and methanol in blood samples from 519 individuals suspected of drinking and driving in Sweden where the legal alcohol limit is 0.50 mg/g in whole blood (11 mmol/l). The concentration of ethanol in blood ranged from 0.01 to 3.52 mg/g with a mean of 1.83 +/- 0.82 mg/g (+/- S.D.). The frequency distribution was symmetrical about the mean but deviated from normality. A plot of the same data on normal probability paper indicated that it might be composed of two subpopulations (bimodal). The concentration of methanol in the same blood specimens ranged from 1 to 23 mg/l with a mean of 7.3 +/- 3.6 mg/l (+/- S.D.) and this distribution was markedly skew (+). The concentration of ethanol (x) and methanol (y) were positively correlated (r = 0.47, P less than 0.001) and implies that 22% (r2) of the variance in blood-methanol can be attributed to its linear regression on blood-ethanol. The regression equation was y = 3.6 + 2.1 x and the standard error estimate was 0.32 mg/l. This large scatter precludes making reliable estimates of blood-methanol concentration from measurements of blood-ethanol concentration and the regression equation. But higher blood-methanol concentrations are definitely associated with higher blood-ethanol in this sample of Swedish drinking drivers. Frequent exposure to methanol and its toxic products of metabolism, formaldehyde and formic acid, might constitute an additional health risk associated with heavy drinking in predisposed individuals. The determination of methanol in blood of drinking drivers in addition to ethanol could indicate long-standing ethanol intoxication and therefore potential problem drinkers or alcoholics.     

Predicting the position of the source of blood stains for angled impacts

Droplets of pig's blood were dropped onto paper at different angles to the horizontal to produce blood stains. Impact velocities varied from 1.82 to 5.76 m/sec, drop size from 3.7 to 5.0 mm in diameter, and the surface sloped at angles between 22.7 degrees and 90 degrees to the horizontal. From the data a single equation relating stain size to drop size and velocity for all impact angles was produced; ab = 111.74 (Re(1/2)We(1/4))(0.75)D(o)D(o) + 0.00084 with R(2) = 0.88, where a is the stain width, b the stain length, Re the Reynolds number, and We the Weber number. A second equation related the number of spines, N, to drop size, velocity, and surface slope for all impact angles as N = 0.76 We(0.5) sin(3)theta with R(2) = 0.9, where theta is the impact angle. Combining these equations the impact velocity can be determined and hence the position of the stain's source.     

An Impact Velocity Device Design for Blood Spatter Pattern Generation with Considerations for High‐Speed Video Analysis,

A mechanical device that uses gravitational and spring compression forces to create spatter patterns of known impact velocities is presented and discussed. The custom‐made device uses either two or four springs (k₁ = 267.8 N/m, k₂ = 535.5 N/m) in parallel to create seventeen reproducible impact velocities between 2.1 and 4.0 m/s. The impactor is held at several known spring extensions using an electromagnet. Trigger inputs to the high‐speed video camera allow the user to control the magnet's release while capturing video footage simultaneously. A polycarbonate base is used to allow for simultaneous monitoring of the side and bottom views of the impact event. Twenty‐four patterns were created across the impact velocity range and analyzed using HemoSpat. Area of origin estimations fell within an acceptable range (ΔX_av = ?5.5 ± 1.9 cm, ΔY_av = ?2.6 ± 2.8 cm, ΔZ_av = +5.5 ± 3.8 cm), supporting distribution analysis for the use in research or bloodstain pattern training. This work provides a framework for those interested in developing a robust impact device.     

Private Policing in Context

This article considers the development, growth and significance of private policing in a wider context. Section one suggests that the rebirth of private policing is associated with - and, in effect, demands - a change in the conceptual framework with which policing is analysed. While section one addresses the conceptual context of private policing, section two examines its theoretical context by considering various explanations for the post-war growth of commercial security. Moving from specific to general accounts, it is suggested that two explanations - one based upon sociological accounts of the development of modern societies, the other on genealogical accounts of developing mentalities - provide a crucial context for understanding contemporary changes in policing and governance. In the next section, two of these changes - the growing influence of risk-based policing and the increasing significance of diverse patterns of governance - are considered in the context of the fragmented forms of security provision (commercial, municipal, civil and state policing) which are prevalent today. A short concluding section offers some final thoughts on how these arguments impact on the governance of policing. One of the implications contained in this article is that the re-emergence of private policing needs to be considered not only as a problem, but also as an opportunity to identify and address critical questions of contemporary governance.     

Minimum velocity necessary for nonconventional projectiles to penetrate the eye: an experimental study using pig eyes

To satisfy the Criminal Code of Canada's definition of a firearm, a barreled weapon must be capable of causing serious bodily injury or death to a person. Canadian courts have accepted the forensically established criteria of "penetration or rupture of an eye" as serious bodily injury. The minimal velocity of nonconventional ammunition required to penetrate the eye including airsoft projectiles has yet to be established. To establish minimal threshold requirements for eye penetration, empirical tests were conducted using a variety of airsoft projectiles. Using the data obtained from these tests, and previous research using "air gun" projectiles, an "energy density" parameter was calculated for the minimum penetration threshold of an eye. Airsoft guns capable of achieving velocities in excess of 99 m/s (325 ft/s) using conventional 6-mm airsoft ammunition will satisfy the forensically established criteria of "serious bodily injury." The energy density parameter for typical 6-mm plastic airsoft projectiles is 4.3 to 4.8 J/cm2. This calculation also encompasses 4.5-mm steel BBs.     

The “state-led-economy” issue in the BIT negotiations and its policy implications for China

The state-led-economy provisions in the U.S. model BIT, which was released in April 2012, aims to impose strict regulations on the SOEs and exert great influence on state-led economy model. China and the U.S. are now in the midst of negotiating a BIT, and the U.S. government insists on negotiating on the basis of its 2012 model BIT. If China is to accept the 2012 U.S. model for the proposed BIT between the two nations, unprecedented international obligations will be placed in the field of international investment. In this context, in order to provide a reference for the BIT negotiation, the author will analyze, from the perspective of normative jurisprudence, which economic activities are included in the scope of state-led economy provisions, whether China should accept the clauses and the possible impact of accepting it. China’s economy has indivisible relationship with State-owned enterprises (SOEs). At present, most of these SOEs have clustered in those sectors that play crucial roles in the national economy such as energy, telecommunication and finances. Despite several rounds of reform on the SOEs aiming at a separation of governmental functions from corporate management, and a modern market-oriented governance structure, Chinese SOEs remain monopolies or de facto monopolies with exclusive access to many important industries relevant to national economy and people’s livelihood. Further, SOEs can enjoy a lot of privileges in their operation, some even have certain regulatory authority which is supposed to be exercised by the government. This kind of economic model is called State-led economy. The 2012 U.S. model for bilateral investment treaties (BIT) is characterized by the inclusion of the state-led economy provisions, which means that there are more restrictive regulations governing SOEs and their special treatment, and countervailing their competition implication in the host country and their home country. Apart from creating a fair and impartial environment for the investors, this international investment regime, represented by 2012 U.S. BIT model, is in some way, intended to alter the host country’s economic governance regime. In accordance with the decision of the 5th round of the U.S.–China Strategic and Economic Dialogue, both parties are dedicated to proceeding the BIT negotiations (The 5th Round of the U.S.–China Strategic and Economic Dialogue: broad consensus achieved and positive progress made, People’s Daily, p 3, 2013). The U.S. government has insisted that they would base its 2012 model as a blueprint of BIT text negotiation. Seemingly to illustrate, the 6th round of the U.S.–China Strategic and Economic Dialogue has reached a consensus that an earlier launch of negotiation on the negative list will be expected in 2015 (The 6th Round of the U.S.–China Strategic and Economic Dialogue: broad consensus achieved and positive progress made, People’s Daily, p 3, 2014; Ministry of Commerce of the People’s Republic of China, The 14th Round of the U.S.–China Investment Treaty Negotiation is Held in Washington, D.C., 2014). If China is to accept the new BIT model, it will bring China a bundle of increasing obligations under this system and an unprecedented impact on China’s mode for economic development. As a contracting party, China will have to carry out a comprehensively economic reform to comply with the disciplines specified in the BIT. It is also understandable that the incorporation of the state-led economy provision in the China–U.S. BIT will in turn accelerate the domestic economic reforms. In this context, research on the issue of state-led economy in the BIT negotiation will be of significance to China’s dealing with the core issue in the BIT, China’s fulfillment of treaty obligations and its promotion of domestic economic reform via BIT negotiations. In order to provide a reference for the BIT negotiation, the author will identify from the perspective of normative jurisprudence, the economic activities that fall within the scope of state-led economy provisions, project the possible impact of state-led economy provisions and how China should handle negotiation surrounding the state-led economy issue.

     

Layers of decision: Linking social definitions of corruption and willingness to take action

The literature available about social definitions of corruption is surprisingly discrete from that which addresses the issue of whistleblowing or the reporting of crime and corruption. The current study, however, empirically links the two. A survey of more than 1300 public sector employees was undertaken to explore: i) how and why public sector employees define some behaviours as corrupt; ii) factors which may hinder public sector employees taking action about corruption which they may observe at work; and iii) the link between i) and ii). The study found that within the New South Wales (NSW) public sector, views about what constitutes corruption are diverse and that this has a significant, though not exclusive, impact upon the action respondents said they would take in response to workplace corruption. The study discusses other factors which also impact upon the stated decision not to take action about corruption and suggests some possible courses of action for addressing these factors.The research upon which this paper is based formed part of the research program of the Independent Commission Against Corruption.     

Injuries of the Head from Backface Deformation of Ballistic Protective Helmets Under Ballistic Impact

Modern ballistic helmets defeat penetrating bullets by energy transfer from the projectile to the helmet, producing helmet deformation. This deformation may cause severe injuries without completely perforating the helmet, termed “behind armor blunt trauma” (BABT). As helmets become lighter, the likelihood of larger helmet backface deformation under ballistic impact increases. To characterize the potential for BABT, seven postmortem human head/neck specimens wearing a ballistic protective helmet were exposed to nonperforating impact, using a 9 mm, full metal jacket, 124 grain bullet with velocities of 400–460 m/s. An increasing trend of injury severity was observed, ranging from simple linear fractures to combinations of linear and depressed fractures. Overall, the ability to identify skull fractures resulting from BABT can be used in forensic investigations. Our results demonstrate a high risk of skull fracture due to BABT and necessitate the prevention of BABT as a design factor in future generations of protective gear.     

Estimating Projectile Perpendicular Impact Velocity on Metal Sheet Targets from the Shape of the Target Hole

Abstract:  The correlation between bullet hole shapes in metal and projectile impact velocity was examined. A series of shots were fired from an M-16A1 assault rifle of 5.56 mm caliber toward a 1-mm thick metal target. All shots were fired at a perpendicular angle to the metal sheets, and the velocity was measured just before the projectile hit the target. Velocities ranged between 400 and 900 m/sec. From the replica of the shooting hole, a perpendicular plane was created, showing the symmetrical properties of the hole. The best mathematical equation describing the shape of the entrance hole was the exponential function in the form:
The empirical equation of the hole defined using the regression method is:
This equation describes the general shape of shooting holes created by velocities ranging from 440 to 750 m/sec. From this equation, one can estimate the bullet velocity when it hits the target.     

实验性早期心肌挫伤的免疫组织化学研究

应用机械式弹性拉力打击器，以10．0m／s速度冲击犬胸骨心前区，建立免疫组织化学染色对伤后2～5分钟、30～60分钟、3小时及5小时心肌挫伤组织中Mb、CK－BB及CK－MM的变化进行观察。结果表明：（1）心肌挫伤后2～5分钟检出心内膜下肌层已有重度心肌Mb脱失及中度CK－BB、CK－MM脱失，并沉积于心肌纤维间，同时吸收入血。随着伤后时间延长，挫伤区三种物质脱失加重，但间质中沉积量减少乃至消失；（2）波浪变心肌中也可见三种物质的轻度脱失；（3）同一心脏中不同部位心肌的损伤程度不同、证明应用免疫组织化学染色技术可发现心肌挫伤性损害。心前区受到相当程度的钝力冲击后心脏不同部位损害程度不同。     

An investigation into pellet dispersion ballistics.

Existing works on pellet dispersion ballistics are confined to some data-based models derived from statistical analysis of observed patterns on targets but the underlying process causing the dispersion lacks due attention. The present article delves into the relatively unexplored areas of dispersion phenomena, and attempts to develop a theoretical model for general application. The radial velocity distribution of pellets has been worked out by probing into the physical process of dispersion based on transfer of momentum from undispersed shot mass to dispersed pellets. The ratio 2u/v0 (u = root mean square (r.m.s.) radial velocity and v0 = muzzle velocity of the pellets) is found to be fairly constant for a fixed gun-ammunition combination and has been suitably designated as 'Dispersion Index' (DI) characterising its dispersion capability. The present model adequately accounts for pellet distribution on targets and it appears that 'Effective Shot Dispersion' (ESD) as introduced by Mattoo and Nabar [ESD = [(4/N0)sigma Ri2]1/2, where N(0) is the total number of pellets and Ri is the radial distance of the i-th pellet from centre of pattern], gives a faithful numerical measure of overall dispersion at a given distance. A relationship between ESD and firing distance, incorporating the effects of air resistance and gravity has been worked out, which reveals that DI controls the dispersion at a given distance. For small distances (less than 20 m) the relation reduces to a linear one, as already observed empirically and looks like ESD = E0+DI x firing distance, E0 being a parameter dependent on gun and ammunition. The present model, unlike earlier ones, is versatile enough to explain the natures of the dependence of dispersion on firing distance as well as on gun-ammunition parameters, which are essential for a faithful reconstruction of a crime scene. The model has been tested with such experimental data as are available and reasonable agreement is observed.