WorldWideScience

Sample records for ballistic impact laboratory

  1. Survivability Armor Ballistic Laboratory (SABL)

    Data.gov (United States)

    Federal Laboratory Consortium — The SABL provides independent analysis, ballistic testing, data collection, data reduction and qualification of current and advanced armors. Capabilities: The SABL...

  2. Small unmanned aircraft ballistic impact speed

    DEFF Research Database (Denmark)

    La Cour-Harbo, Anders

    2018-01-01

    A study of how smaller unmanned aircraft will fall in case of failure. The aim is to determine the impact speed of a drone givens its general shape and aerodynamic behavior. This will include both CFD simulations and real world test of ballistic drops of smaller drones.......A study of how smaller unmanned aircraft will fall in case of failure. The aim is to determine the impact speed of a drone givens its general shape and aerodynamic behavior. This will include both CFD simulations and real world test of ballistic drops of smaller drones....

  3. Towards reliable simulations of ballistic impact on concrete structures

    NARCIS (Netherlands)

    Khoe, Y.S.; Tyler Street, M.D.; Maravalalu Suresh,, R.S.; Weerheijm, J.

    2013-01-01

    Protection against weapon effects like ballistic impacts, fragmenting shells and explosions is the core business of the Explosions, Ballistics and Protection department of TNO (The Netherlands). Experimental and numerical research is performed to gain and maintain the knowledge to support the Dutch

  4. Towards reliable simulations of ballistic impact on concrete structures

    NARCIS (Netherlands)

    Khoe, Y.S.; Tyler Street, M.D.; Maravalalu Suresh,, R.S.; Weerheijm, J.

    2013-01-01

    Protection against weapon effects like ballistic impacts, fragmenting shells and explosions is the core business of the Explosions, Ballistics and Protection department of TNO (The Netherlands). Experimental and numerical research is performed to gain and maintain the knowledge to support the Dutch

  5. Impacts of Deflection Nose on Ballistic Trajectory Control Law

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2014-01-01

    Full Text Available The deflection of projectile nose is aimed at changing the motion of the projectile in flight with the theory of motion control and changing the exterior ballistics so as to change its range and increase its accuracy. The law of external ballistics with the deflectable nose is considered as the basis of the design of a flight control system and an important part in the process of projectile development. Based on the existing rigid external ballistic model, this paper establishes an external ballistic calculation model for deflectable nose projectile and further establishes the solving programs accordingly. Different angle of attack, velocity, coefficients of lift, resistance, and moment under the deflection can be obtained in this paper based on the previous experiments and emulation researches. In the end, the author pointed out the laws on the impaction of external ballistic trajectory by the deflection of nose of the missile.

  6. Injuries of the head from backface deformation of ballistic protective helmets under ballistic impact.

    Science.gov (United States)

    Rafaels, Karin A; Cutcliffe, Hattie C; Salzar, Robert S; Davis, Martin; Boggess, Brian; Bush, Bryan; Harris, Robert; Rountree, Mark Steve; Sanderson, Ellory; Campman, Steven; Koch, Spencer; Dale Bass, Cameron R

    2015-01-01

    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.

  7. Balancing ballistic protection against physiological strain: evidence from laboratory and field trials.

    Science.gov (United States)

    Taylor, Nigel A S; Burdon, Catriona A; van den Heuvel, Anne M J; Fogarty, Alison L; Notley, Sean R; Hunt, Andrew P; Billing, Daniel C; Drain, Jace R; Silk, Aaron J; Patterson, Mark J; Peoples, Gregory E

    2016-02-01

    This project was based on the premise that decisions concerning the ballistic protection provided to defence personnel should derive from an evaluation of the balance between protection level and its impact on physiological function, mobility, and operational capability. Civilians and soldiers participated in laboratory- and field-based studies in which ensembles providing five levels of ballistic protection were evaluated, each with progressive increases in protection, mass (3.4-11.0 kg), and surface-area coverage (0.25-0.52 m(2)). Physiological trials were conducted on volunteers (N = 8) in a laboratory, under hot-dry conditions simulating an urban patrol: walking at 4 km·h(-1) (90 min) and 6 km·h(-1) (30 min or to fatigue). Field-based trials were used to evaluate tactical battlefield movements (mobility) of soldiers (N = 31) under tropical conditions, and across functional tests of power, speed, agility, endurance, and balance. Finally, trials were conducted at a jungle training centre, with soldiers (N = 32) patrolling under tropical conditions (averaging 5 h). In the laboratory, work tolerance was reduced as protection increased, with deep-body temperature climbing relentlessly. However, the protective ensembles could be grouped into two equally stressful categories, each providing a different level of ballistic protection. This outcome was supported during the mobility trials, with the greatest performance decrement evident during fire and movement simulations, as the ensemble mass was increased (-2.12%·kg(-1)). The jungle patrol trials similarly supported this outcome. Therefore, although ballistic protection does increase physiological strain, this research has provided a basis on which to determine how that strain can be balanced against the mission-specific level of required personal protection.

  8. Study on Titanium Alloy TC4 Ballistic Penetration Resistance Part Ⅰ: Ballistic Impact Tests

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tao; CHEN Wei; GUAN Yupu; GAO Deping

    2012-01-01

    Ballistic impact test of different-scale casings is an efficient way to demonstrate the casing containment capability at the preliminary design stage of the engine.For the sake of studying the titanium alloy TC4 casing performance,the ballistic tests of flat and curved simulation casing are implemented by using two flat blades of different sizes as the projectile.The impact mechanism and failure of the target are discussed.Impact of the projectile is a highly nonlinear transient process with the large deformation of the target.On the impact,failures of the flat casing and the subscale casing are similar,concluding two parts,the global dishing and localized ductile tearing.The main localized failure mode combines plugging (shear) and petaling (shear) if the projectile perforates or penetrates,while crater (shear) if the projectile rebounds.The ballistic limit equation is verified by the test data and the results show that this empirical equation could be a practical way to estimate the critical velocity.

  9. Excellent Ballistic Impact Properties Demonstrated By New Fabric

    Science.gov (United States)

    Pereira, J. Michael; Revilock, Duane M.; Hopkins, Dale A.

    2002-01-01

    Recently, a relatively new industrial fiber known by the trade name Zylon has been under commercial development by Toyobo Co., Ltd., Japan. In ballistic impact tests conducted at the NASA Glenn Research Center, it was found that dry fabric braided of Zylon had greater ballistic impact capacity than comparable (braid style and weight) fabric braided of Kevlar. To study the potential use of Zylon fabric in jet engine containment systems, the fabric was tested in Glenn's Structures and Acoustics Division Ballistic Impact Facility under conditions simulating those which occur in a jet engine blade-out event. Circular ring test specimens were fabricated by wrapping five layers of braided Zylon or Kevlar fabric around an inner ring made of a thin sheet of aluminum and a 1-in.-thick layer of aluminum honeycomb. The test specimens had an inner diameter of 40 in., an axial length of 10 in., and a wall thickness of approximately 1.5in. A test specimen is shown in the photograph.

  10. Ultrasonic Imaging of Ballistically Impacted Composite Armour

    Directory of Open Access Journals (Sweden)

    S.S. Samant

    2013-12-01

    Full Text Available The ability of Kevlar-Polypropylene composite armour to withstand the impact of projectile (calibre 7.62 mm is investigated using immersion type ultrasonic c- scan method. The Kevlar polypropylene composite laminate is made of 36 Kevlar and 74 polypropylene layers having thickness 20 mm and are subjected to bullet impact with different striking velocities. At each location of the probe ultrasonic features peak amplitude and signal amplitude are extracted from digitized data and stored in controlling PC. Using UPGMA clustering technique, c-scan images of impacted zones of Kevlar polypropylene composite plate has been generated. The extent of core damage zone in the laminates correlated to the impact velocities of projectile. It is observed that areas of core damage zone are found to increase with the energy loss of the bullet. The area of core damage zone increases rapidly in case of shot lodging. Also peak amplitude and signal energy features are more reliable and sensitive for evaluation of damage in composite laminates.

  11. Hybrid composite laminates reinforced with Kevlar/carbon/glass woven fabrics for ballistic impact testing.

    Science.gov (United States)

    Randjbaran, Elias; Zahari, Rizal; Jalil, Nawal Aswan Abdul; Majid, Dayang Laila Abang Abdul

    2014-01-01

    Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  12. Hybrid Composite Laminates Reinforced with Kevlar/Carbon/Glass Woven Fabrics for Ballistic Impact Testing

    Directory of Open Access Journals (Sweden)

    Elias Randjbaran

    2014-01-01

    Full Text Available Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  13. Deformation and Damage of Two Aluminum Alloys from Ballistic Impact

    Science.gov (United States)

    Anderson, Charles E., Jr.; Dannemann, Kathryn A.

    2002-07-01

    A series of impact experiments were conducted on 4.76-mm-thick aluminum plates to investigate the deformation and damage behavior of two aluminum alloys, 6061-T6 and 7075-T6. The Sierra 165 lead-filled bullet was used to load the plates. Impact velocities were varied from approximately 260 m/s to 370 m/s. The flow stress for 7075-T6 aluminum is approximately twice that for 6061-T6 aluminum; however, the ballistic limit velocities differ by only 10%. The 7075-T6 aluminum plates exhibit less deformation than the 6061-T6 plates at the same impact velocity, but at some critical velocity, a through-thickness crack appears in the 7075-T6 plate, ultimately leading to plate perforation. In contrast, the 6061-T6 plates continue to deform and fail by ductile tearing. These differences in damage/failure result in the two alloys having much closer ballistic limit velocities than expected based on differences in strength.

  14. Ballistic Impact on Glass/Epoxy Composite Laminates

    Directory of Open Access Journals (Sweden)

    R. Velmurugan

    2014-07-01

    Full Text Available Glass/epoxy composite laminates are subjected to impact loading and the energy absorbing capacity of the laminates is studied. In the present study, laminates with four different orientations and thickness values are considered. Analytical study is carried out based on energy method and results are compared with FE results obtained from Abaqus/Explicit software. Results obtained from the analytical methods are showing good agreement with the FE results. It is found that cross-ply laminates are most efficient in ballistic resistance when compared with the laminates of other orientations. It is also noticed that the energy absorbing capacity is decreasing with increase in velocity of the projectile for a given lay-up and thickness value.Defence Science Journal, Vol. 64, No. 4, July 2014, pp. 393-399, DOI:http://dx.doi.org/10.14429/dsj.64.3882 

  15. Head Impact Laboratory (HIL)

    Data.gov (United States)

    Federal Laboratory Consortium — The HIL uses testing devices to evaluate vehicle interior energy attenuating (EA) technologies for mitigating head injuries resulting from head impacts during mine/...

  16. Ballistic Impact Properties of Zr-Based Amorphous Alloy Composites Reinforced with Woven Continuous Fibers

    Science.gov (United States)

    Kim, Gyeong Su; Son, Chang-Young; Lee, Sang-Bok; Lee, Sang-Kwan; Song, Young Buem; Lee, Sunghak

    2012-03-01

    This study aims at investigating ballistic impact properties of Zr-based amorphous alloy (LM1 alloy) matrix composites reinforced with woven stainless steel or glass continuous fibers. The fiber-reinforced composites with excellent fiber/matrix interfaces were fabricated without pores and misinfiltration by liquid pressing process, and contained 35 to 41 vol pct of woven continuous fibers homogeneously distributed in the amorphous matrix. The woven-STS-continuous-fiber-reinforced composite consisted of the LM1 alloy layer of 1.0 mm in thickness in the upper region and the fiber-reinforced composite layer in the lower region. The hard LM1 alloy layer absorbed the ballistic impact energy by forming many cracks, and the fiber-reinforced composite layer interrupted the crack propagation and blocked the impact and traveling of the projectile, thereby resulting in the improvement of ballistic performance by about 20 pct over the LM1 alloy. According to the ballistic impact test data of the woven-glass-continuous-fiber-reinforced composite, glass fibers were preferentially fragmented to form a number of cracks, and the amorphous matrix accelerated the fragmentation of glass fibers and the initiation of cracks. Because of the absorption process of ballistic impact energy by forming very large amounts of cracks, fragments, and debris, the glass-fiber-reinforced composite showed better ballistic performance than the LM1 alloy.

  17. Experimental Investigation on the Ballistic Resistace of Metal Plates Subjected to Impact of Rigid Projectiles

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; DENG Yun-fei; CAO Zong-sheng

    2012-01-01

    The ballistic performance of monolithic and multi-layered steel plates impacted by ogival-nosed projectiles was investigated by using a gas gun experimentally.The total thickness of in-contact multi-layered target was equally to that of monolithic target.The results show that,for the high strength targets,the monolithic targets have greater ballistic limit velocities than multi-layered targets,and also the ballistic limit velocities of targets decrease with the increase of the number of layers.However,for the low strength targets,the monolithic targets have lower ballistic limit velocities than multi-layered targets.The differences in target capacity between various impact conditions can be related to the transitions of perforation mechanisms and failure models.

  18. Effect of High Velocity Ballistic Impact on Pretensioned Carbon Fibre Reinforced Plastic (CFRP) Plates

    Science.gov (United States)

    Azhar KAMARUDIN, Kamarul; HAMID, Iskandar ABDUL

    2017-01-01

    This work describes an experimental investigation of the pretensioned thin plates made of Carbon Fibre Reinforced Plastic (CFRP) struck by hemispherical and blunt projectiles at various impact velocities. The experiments were done using a gas gun with combination of pretension equipment positioned at the end of gun barrel near the nozzle. Measurements of the initial and residual velocities were taken, and the ballistic limit velocity were calculated for each procedures. The pretension target results in reduction of ballistic limit compared to non-pretension target for both flat and hemispherical projectiles. Target impacted by hemispherical projectile experience split at earlier impact velocity compared to target by flat projectile. C-Scan images analysis technique was used to show target impact damaged by hemispherical and flat projectiles. The damage area was shown biggest at ballistic limit velocity and target splitting occurred most for pretention plate.

  19. Prediction of Final Velocity of Aramid Fabric-Resin Composite Laminates Subjected to Ballistic Impact

    Institute of Scientific and Technical Information of China (English)

    熊杰; 萧庆亮; 刘冠峰; 顾伯洪; 王善元

    2003-01-01

    The strain rate effects of aramid fiber material,quasi-static and ballistic impact perforation of composite laminates made of aramid fabric and phenolic resin/PVB are investigated respectively by means of MTS, split Hopkinson tension bars and ballistic impact apparatus. The tensile impact experiments on aramid fiber material are performed in strain rate range from 0.01/ s to 1 000/ s. Experinental results show that the mechanical properties of aramid fiber material are insensitive to strain rate in the range from 0. 01/s to 1 000/s. An energy model to predict final velocity of composite laminates subjected to ballistic impact is proposed on the basis of experimental data of quasi-static perforation through the targets. The predicted final velocities show good agreement with the experimental final velocity.

  20. Ballistic impact behaviour of woven fabric composite: Finite element analysis and experiments

    Science.gov (United States)

    Phadnis, V. A.; Pandya, K. S.; Naik, N. K.; Roy, A.; Silberschmidt, V. V.

    2013-07-01

    A mechanical behaviour of plain-weave E-glass fabric/epoxy laminate composite plate exposed to ballistic impact is studied using a finite-element (FE) code Abaqus/Explicit. A ply-level FE model is developed, where a fabric-reinforced ply is modelled as a homogeneous orthotropic elastic material with potential to sustain progressive stiffness degradation due to fiber/matrix cracking, and plastic deformation under shear loading. The model is implemented as a VUMAT user subroutine. Ballistic experiments were carried out to validate the FE model. A parametric study for varying panel thickness is performed to compare impact resistance of the studied composite.

  1. Behavior of Aramid Fiber/Ultrahigh Molecular Weight Polyethylene Fiber Hybrid Composites under Charpy Impact and Ballistic Impact

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The aramid fiber/UHMWPE (ultrahigh molecular weight polyethylene) fiber hybrid composites (AF/DF) were manufactured. By Charpy impact, the low velocity impact behavior of AF/DF composite was studied. And the high velocity impact behavior under ballistic impact was also investigated. The influence of hybrid ratio on the performances of low and high velocity impact was analyzed, and hybrid structures with good impact properties under low velocity impact and high velocity were optimized. For Charpy impact, the maximal impact load increased with the accretion of the AF layers for AF/DF hybrid composites. The total impact power was reduced with the decrease of DF layers and the delamination can result in the increase of total impact power. For ballistic impact, the DF ballistic performance was better than that of the AF and the hybrid ratio had a crucial influence. The failure morphology of AF/DF hybrid composite under Charpy impact and ballistic impact was analyzed. The AF/DF hybrid composites in suitable hybrid ratio could attain better performance than AF or DF composites.

  2. Hazard map for volcanic ballistic impacts at El Chichón volcano (Mexico)

    Science.gov (United States)

    Alatorre-Ibarguengoitia, Miguel; Ramos-Hernández, Silvia; Jiménez-Aguilar, Julio

    2014-05-01

    The 1982 eruption of El Chichón Volcano in southeastern Mexico had a strong social and environmental impact. The eruption resulted in the worst volcanic disaster in the recorded history of Mexico, causing about 2,000 casualties, displacing thousands, and producing severe economic losses. Even when some villages were relocated after the 1982 eruption, many people still live and work in the vicinities of the volcano and may be affected in the case of a new eruption. The hazard map of El Chichón volcano (Macías et al., 2008) comprises pyroclastic flows, pyroclastic surges, lahars and ash fall but not ballistic projectiles, which represent an important threat to people, infrastructure and vegetation in the case of an eruption. In fact, the fatalities reported in the first stage of the 1982 eruption were caused by roof collapse induced by ashfall and lithic ballistic projectiles. In this study, a general methodology to delimit the hazard zones for volcanic ballistic projectiles during volcanic eruptions is applied to El Chichón volcano. Different scenarios are defined based on the past activity of the volcano and parameterized by considering the maximum kinetic energy associated with ballistic projectiles ejected during previous eruptions. A ballistic model is used to reconstruct the "launching" kinetic energy of the projectiles observed in the field. The maximum ranges expected for the ballistics in the different explosive scenarios defined for El Chichón volcano are presented in a ballistic hazard map which complements the published hazard map. These maps assist the responsible authorities to plan the definition and mitigation of restricted areas during volcanic crises.

  3. Fractographic Analysis of High Performance Fabric Reinforced Composites after Ballistic Impact

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hua-peng; SHI Mei-wu; ZHANG Jian-chun; WANG Shan-yuan

    2002-01-01

    To improve the ballistic resistance of the ballistic resistant composites, this paper deals with the microscopically fractographic analysis of their failure caused by Fragments Simulated Projectiles (FSP) and bullet with the objective to clarify the failure modes of the compoosites, and to further improve the ballistic resistance of the ballistic systems by hybridizing based on the currently market available materials.After the analysis, it has been found that the penetration of the FSP into the panels causes shear failure in the impact side of the target but extensive tension failure in the distal side of the composite target. The failure modes also include matrix fragmentation, and delamination, and with resin content as high as 30%,more filaments are broken by cutting in the composite.Compared with the failure caused by bullet, there are more cutting or shearing for the failure caused by FSP,but more compressive failure caused by bullet. This paper also discusses the effects of hybridizing different types of fabrics on the ballistic resistance of the composite based on the observations and numerical simulation.

  4. An experimental study of the self-healing behavior of ionomeric systems under ballistic impact tests

    Science.gov (United States)

    Grande, A. M.; Coppi, S.; Di Landro, L.; Sala, G.; Giacomuzzo, C.; Francesconi, A.; Rahman, M. A.

    2012-04-01

    This research deals with the investigation of the self-healing behavior after ballistic damage of ethylene-methacrylic acid ionomers and theirs blends with epoxidized natural rubber (ENR). The self-healing capability was studied by ballistic puncture tests under different experimental conditions as sample thickness, bullet speed, diameter and shape. Bullet speed ranging from few hundreds meters per second to few km/s were employed. The healing efficiency was evaluated by applying a pressure gradient trough the plates and by checking for possible flow at the damage zone. A morphology analysis of the impact area was made observing all samples by scanning electron microscope.

  5. Ballistic Behaviour of Thick Steel Armour Plate under Oblique Impact : Experimental Investigation II

    OpenAIRE

    S. N. Dikshit

    1999-01-01

    The ballistic behaviour of thick steel armour plate at different obliquities has been investigated. Ballistic experiments were conducted in the velocity range 300-800 mls at 0°, 15°, 30° and 45° obliquity .A steel, conical projectile or 6.1 mm diameter was impacted on a 10 mm thick steel armour plate. At 30° and 45° obliquity, the plate offers protection up to a striking velocity of 800 mls. At zero obliquity, the plate provides protection below 6~ m/s. The depth of penetration decreases with...

  6. Ballistic Behaviour of Thick Steel Armour Plate under Oblique Impact: Experimental Investigation .

    OpenAIRE

    S. N. Dikshit

    1998-01-01

    The ballistic behaviour of thick steel amlOW- plate has been investigated at different obliquity when impacted by an ogive-shaped steel projectile. The ballistic experiments have been conducted in the velocity range 300-800 m/s. Both the thickness of the target plate and the diameter of the projectile were 20 Inm. At 30 and 45. obliquity 20 mm plate provides full protection at 800 m/s, whereas at 0 and 15. obliquity, the plate provides protection up to 600 m/s. At 15 and 30° obliquity, the pl...

  7. Ballistic Behaviour of Thick Steel Armour Plate under Oblique Impact : Experimental Investigation II

    OpenAIRE

    S. N. Dikshit

    1999-01-01

    The ballistic behaviour of thick steel armour plate at different obliquities has been investigated. Ballistic experiments were conducted in the velocity range 300-800 mls at 0°, 15°, 30° and 45° obliquity .A steel, conical projectile or 6.1 mm diameter was impacted on a 10 mm thick steel armour plate. At 30° and 45° obliquity, the plate offers protection up to a striking velocity of 800 mls. At zero obliquity, the plate provides protection below 6~ m/s. The depth of penetration decreases with...

  8. Ballistic Behaviour of Thick Steel Armour Plate under Oblique Impact: Experimental Investigation .

    OpenAIRE

    S. N. Dikshit

    1998-01-01

    The ballistic behaviour of thick steel amlOW- plate has been investigated at different obliquity when impacted by an ogive-shaped steel projectile. The ballistic experiments have been conducted in the velocity range 300-800 m/s. Both the thickness of the target plate and the diameter of the projectile were 20 Inm. At 30 and 45. obliquity 20 mm plate provides full protection at 800 m/s, whereas at 0 and 15. obliquity, the plate provides protection up to 600 m/s. At 15 and 30° obliquity, the pl...

  9. Converting Between PLY and Ballistic Research Laboratory-Computer-Aided Design (BRL-CAD) File Formats

    Science.gov (United States)

    2015-02-01

    Converting Between PLY and Ballistic Research Laboratory–Computer-Aided Design (BRL- CAD ) File Formats by Rishub Jain ARL-CR-0760...0760 February 2015 Converting Between PLY and Ballistic Research Laboratory–Computer-Aided Design (BRL- CAD ) File Formats Rishub Jain US...and Ballistic Research Laboratory–Computer-Aided Design (BRL- CAD ) File Formats 5a. CONTRACT NUMBER W911NF-10-2-0076 5b. GRANT NUMBER 5c. PROGRAM

  10. Hazard map for volcanic ballistic impacts at Popocatépetl volcano (Mexico)

    Science.gov (United States)

    Alatorre-Ibargüengoitia, Miguel A.; Delgado-Granados, Hugo; Dingwell, Donald B.

    2012-11-01

    During volcanic explosions, volcanic ballistic projectiles (VBP) are frequently ejected. These projectiles represent a threat to people, infrastructure, vegetation, and aircraft due to their high temperatures and impact velocities. In order to protect people adequately, it is necessary to delimit the projectiles' maximum range within well-defined explosion scenarios likely to occur in a particular volcano. In this study, a general methodology to delimit the hazard zones for VBP during volcanic eruptions is applied to Popocatépetl volcano. Three explosion scenarios with different intensities have been defined based on the past activity of the volcano and parameterized by considering the maximum kinetic energy associated with VBP ejected during previous eruptions. A ballistic model is used to reconstruct the "launching" kinetic energy of VBP observed in the field. In the case of Vulcanian eruptions, the most common type of activity at Popocatépetl, the ballistic model was used in concert with an eruptive model to correlate ballistic range with initial pressure and gas content, parameters that can be estimated by monitoring techniques. The results are validated with field data and video observations of different Vulcanian eruptions at Popocatépetl. For each scenario, the ballistic model is used to calculate the maximum range of VBP under optimum "launching" conditions: ballistic diameter, ejection angle, topography, and wind velocity. Our results are presented in the form of a VBP hazard map with topographic profiles that depict the likely maximum ranges of VBP under explosion scenarios defined specifically for Popocatépetl volcano. The hazard zones shown on the map allow the responsible authorities to plan the definition and mitigation of restricted areas during volcanic crises.

  11. KevlarTM Fiber-Reinforced Polybenzoxazine Alloys for Ballistic Impact Application

    Directory of Open Access Journals (Sweden)

    Chanchira Jubsilp

    2011-10-01

    Full Text Available A light weight ballistic composites from KevlarTM-reinforcing fiber having polybenzoxazine (BA/urethane prepolymer (PU alloys as a matrix were investigated in this work. The effect of alloy compositions on the ballistic composite properties was determined. The results revealed that the enhancement in the glass transition temperature (Tg of the KevlarTM-reinforced BA/PU composites compared to that of the KevlarTM-reinforced polybenzoxazine composite was observed. The increase of the elastomeric PU content in the BA/PU alloy resulted in samples with tougher characteristics. The storage modulus of the KevlarTM-reinforced BA/PU composites increased with increasing the mass fraction of polybenzoxazine. A ballistic impact test was also performed on the KevlarTM-reinforced BA/PU composites using a 9 mm handgun. It was found that the optimal contents of PU in the BA/PU alloys should be approximately 20wt%. The extent of the delaminated area and interfacial fracture were observed to change with the varied compositions of the matrix alloys. The appropriate thickness of KevlarTM-reinforced 80/20 BA/PU composite panel was 30 plies and 50 plies to resist the penetration from the ballistic impact equivalent to levels II-A and III-A of NIJ standard. The arrangement of composite panels with the higher stiffness panel at the front side also showed the best efficiency of ballistic penetration resistance.

  12. An experimental study to estimate ballistic limit velocity for glass epoxy composite under high velocity impact with two different projectile geometry.

    Directory of Open Access Journals (Sweden)

    Erfan Ebadi Afshar

    2016-12-01

    Full Text Available In this research a study in estimating velocity ballistic in glass epoxy composite sheet with construction process of padding-manually, under high velocity impact was conducted for laboratory with gas gun device and ballistic limit velocity for composite sheet with a thickness 2 mm were obtained under geometry of projectile. So that result is obtained in construction of military armor, aerospace industry, automotive, and general any industry to be used with impact challenges and faced dealt. That is down strength and toughness and resistance to crack growth in structural weight. Glass epoxy composite (three layers made and for build projectile of steel rod VCN200 (Brand steel 1.6580 was used to manually peeling method; amounting to 16 gas gun device was performed to dimensions of 65 × 65 mm on the samples. With results analysis obtained ballistic tests were two important conclusions: first, in compare of two projectile geometry together, projectile with spherical tip compared to projectile with conical tip for better performance in penetrate and pass of this armor; second ballistic limit velocity for armor was obtained under spherical tip projectile 136.6 (meters per second and under conic tip projectile 143.6 (meters per second.

  13. Penetration of sandwich plates with hybrid-cores under oblique ballistic impact

    Directory of Open Access Journals (Sweden)

    Changye Ni

    2014-01-01

    Full Text Available The oblique penetration performance of lightweight hybrid-cored sandwich plates are investigated numerically. To compose the hybrid-core, ceramic prisms are inserted into pyramidal metal lattice trusses and fixed using epoxy resin. Three-dimensional finite element simulations are carried out for the hybridcored sandwich impacted at 15°, 30°, 45°, and 60° obliquity by a hemispherical projectile. The ballistic limit, the energy absorbed by the constituting elements, and the critical oblique angle are quantified. The physical mechanisms underlying the failure and the influence of fundamental system parameters are explored. The angle of obliquity is found to have significant influence on the ballistic trajectory and erosion of the projectile, thus it is important for the impact response and penetration resistance of the sandwich. For oblique angles equal to or larger than 45°, the projectile moves mainly horizontally and can not effectively penetrate across the sandwich.

  14. Densification and Devitrification of Fused Silica Induced by Ballistic Impact: A Computational Investigation

    Science.gov (United States)

    2015-03-25

    and P. G. Dehmer, “Effect of the tin- vs. air-side plate-glass orientation on the impact response and penetration resistance of a laminated ...the multi-hit ballistic-protection performance of laminated transparent-armor systems,” Journal of Materials Engineering and Performance, vol. 21, no...www.hindawi.com Volume 2014 Nanoscience Journal of Textiles Hindawi Publishing Corporation http://www.hindawi.com Volume 2014 Journal of Nanotechnology

  15. The impact of defect scattering on the quasi-ballistic transport of nanoscale conductors

    Energy Technology Data Exchange (ETDEWEB)

    Esqueda, I. S., E-mail: isanchez@isi.edu; Fritze, M. [Information Sciences Institute, University of Southern California, Marina del Rey, California 90292 (United States); Cress, C. D. [Electronics Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States); Cao, Y.; Che, Y.; Zhou, C. [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States)

    2015-02-28

    Using the Landauer approach for carrier transport, we analyze the impact of defects induced by ion irradiation on the transport properties of nanoscale conductors that operate in the quasi-ballistic regime. Degradation of conductance results from a reduction of carrier mean free path due to the introduction of defects in the conducting channel. We incorporate scattering mechanisms from radiation-induced defects into calculations of the transmission coefficient and present a technique for extracting modeling parameters from near-equilibrium transport measurements. These parameters are used to describe degradation in the transport properties of nanoscale devices using a formalism that is valid under quasi-ballistic operation. The analysis includes the effects of bandstructure and dimensionality on the impact of defect scattering and discusses transport properties of nanoscale devices from the diffusive to the ballistic limit. We compare calculations with recently published measurements of irradiated nanoscale devices such as single-walled carbon nanotubes, graphene, and deep-submicron Si metal-oxide-semiconductor field-effect transistors.

  16. Ballistics for the neurosurgeon.

    Science.gov (United States)

    Jandial, Rahul; Reichwage, Brett; Levy, Michael; Duenas, Vincent; Sturdivan, Larry

    2008-02-01

    Craniocerebral injuries from ballistic projectiles are qualitatively different from injuries in unconfined soft tissue with similar impact. Penetrating and nonpenetrating ballistic injuries are influenced not only by the physical properties of the projectile, but also by its ballistics. Ballistics provides information on the motion of projectiles while in the gun barrel, the trajectory of the projectile in air, and the behavior of the projectile on reaching its target. This basic knowledge can be applied to better understand the ultimate craniocerebral consequences of ballistic head injuries.

  17. Combined Structural and Compositional Evolution of Planetary Rings Due to Micrometeoroid Impacts and Ballistic Transport

    Science.gov (United States)

    Estrada, Paul R.; Durisen, Richard H.; Cuzzi, Jeffrey N.; Morgan, Demitri A.

    2015-01-01

    We introduce improved numerical techniques for simulating the structural and compositional evolution of planetary rings due to micrometeoroid bombardment and subsequent ballistic transport of impact ejecta. Our current, robust code is capable of modeling structural changes and pollution transport simultaneously over long times on both local and global scales. In this paper, we describe the methodology based on the original structural code of Durisen et al. (1989, Icarus 80, 136-166) and on the pollution transport code of Cuzzi and Estrada (1998, Icarus 132, 1-35). We provide demonstrative simulations to compare with, and extend upon previous work, as well as examples of how ballistic transport can maintain the observed structure in Saturn's rings using available Cassini occultation optical depth data. In particular, we explicitly verify the claim that the inner B (and presumably A) ring edge can be maintained over long periods of time due to an ejecta distribution that is heavily biased in the prograde direction through a balance between the sharpening effects of ballistic transport and the broadening effects of viscosity. We also see that a "ramp"-like feature forms over time just inside that edge. However, it does not remain linear for the duration of the runs presented here unless a less steep ejecta velocity distribution is adopted. We also model the C ring plateaus and find that their outer edges can be maintained at their observed sharpness for long periods due to ballistic transport. We hypothesize that the addition of a significant component of a retrograde-biased ejecta distribution may help explain the linearity of the ramp and is probably essential for maintaining the sharpness of C ring plateau inner edges. This component would arise for the subset of micrometeoroid impacts which are destructive rather than merely cratering. Such a distribution will be introduced in future work.

  18. SPH Simulation of Ballistic Impact on Ceramic Plate

    Directory of Open Access Journals (Sweden)

    Chetan Swaroop

    2013-06-01

    Full Text Available This paper studies the use of smooth particle hydrodynamics (SPH numerical technique to simulate the impact, penetration and perforation of Ceramic plate (Al2O3-99.7% by Lead Round Nose (LRN projectile. The general discussion of the SPH solver is introduced first then AUTODYN 2D simulation of penetration and perforation of ceramic plate. The numerical prediction of the time history of velocity of bullet is investigated for a range of impact velocity between 400m/s to 800m/s and an empirical relation is derived between impact velocity and residual velocity. For this type of problem, the SPH approach can provide significant advantages over more traditional numerical methods.

  19. Investigations of impact biomechanics for penetrating ballistic cases.

    Science.gov (United States)

    Awoukeng-Goumtcha, A; Taddei, L; Tostain, F; Roth, S

    2014-01-01

    This study aims to investigate the penetration of a projectile into a surrogate human tissue numerically, using Finite Element (FE) simulation. 20% Balistic Gelatin material (BG) is simulated with an elasto-plastic hydrodynamic constitutive law, and then impacted by steel spheres at different velocities. The results from the FE simulations are compared with existing experimental data and other analytical equations from the literature. To our knowledge, this is the first study to investigate a projectile penetration by numerical simulation, and then compare the results with analytical and experimental data from previous studies. This developed model gives encouraging results for further investigations of penetrating impact of projectile in the human body.

  20. Modelling of Ballistic Impact over a Ceramic-Metal Protection System

    Directory of Open Access Journals (Sweden)

    Leandro Neckel

    2013-01-01

    Full Text Available The behavior of ceramic-metal protection against a projectile impact is modeled. The model takes into account the mass and velocity for each stage of the phenomenon. A former model was modified considering more realistic parameters such as geometries and deformation profile. To analyze the model, simulations on different parameters have been run. The impact results of different ballistic projectiles were simulated, and the movement was plotted. In addition, a deterministic simulation on the mechanical properties of the back metal plate properties was done.

  1. Wound Ballistics Modeling for Blast Loading Blunt Force Impact and Projectile Penetration.

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Paul A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is nonexistent but necessary to protect the heart and lungs. In tests against ballistic projectiles, protective apparel is placed over ballistic clay and the projectiles are fired into the armor/clay target. The clay represents the human torso and its behind-armor, permanent deflection is the principal metric used to assess armor protection. Although this approach provides relative merit assessment of protection, it does not examine the behind-armor blunt trauma to crucial torso organs. We propose a modeling and simulation (M&S) capability for wound injury scenarios to the head, neck, and torso of the warfighter. We will use this toolset to investigate the consequences of, and mitigation against, blast exposure, blunt force impact, and ballistic projectile penetration leading to damage of critical organs comprising the central nervous, cardiovascular, and respiratory systems. We will leverage Sandia codes and our M&S expertise on traumatic brain injury to develop virtual anatomical models of the head, neck, and torso and the simulation methodology to capture the physics of wound mechanics. Specifically, we will investigate virtual wound injuries to the head, neck, and torso without and with protective armor to demonstrate the advantages of performing injury simulations for the development of body armor. The proposed toolset constitutes a significant advance over current methods by providing a virtual simulation capability to investigate wound injury and optimize armor design without the need for extensive field testing.

  2. Yarn Pull-Out as a Mechanism for Dissipation of Ballistic Impact Energy in Kevlar KM-2 Fabric, Part 2: Prediction of Ballistic Performance

    Science.gov (United States)

    2004-05-01

    fabrics made from high-strength fibers, such as Kevlar,* Zylon ,† Armos,‡ and Spectra,§ have been widely used in flexible armors such as ballistic vests...pull-out during low velocity (< 300 m/s) impacts of Zylon fabrics, especially when at least two boundaries were unclamped, when impact occurred near the...Kevlar is a registered trademark of DuPont. † Zylon is a registered trademark of Toyobo. ‡ Armos is a registered trademark of Kamenskvolokno JSC

  3. Ballistic Impact Response of Woven Hybrid Coir/Kevlar Laminated Composites

    Directory of Open Access Journals (Sweden)

    Azrin Hani A.R

    2016-01-01

    Full Text Available The effects of different laminated hybrid composites stacking configuration subjected to ballistic impact were investigated. The hybrid composites consist of woven coir (C and woven Kevlar (K layers laminated together. The samples of woven coir were prepared using handloom device. The composites were produced by stacking the laminated woven coir and Kevlar alternately with the presence of the binder. The samples were tested under ballistic impact with different stacking configuration. The results obtained had successfully achieved the National Institute of Justice (NIJ standard level IIA with energy absorption of 435.6 kJ and 412.2 kJ under the projectile speed of between 330 m/s and 321 m/s respectively. Samples that having Kevlar layer at the front face and woven coir layer as back face achieved partial penetration during projectile impact. This orientation is proven to have good impact energy absorption and able to stop projectile at the second panel of the composites.

  4. Experimental study of the coupling parameters influencing the terminal effects of thoracic blunt ballistic impacts.

    Science.gov (United States)

    Pavier, Julien; Langlet, André; Eches, Nicolas; Prat, Nicolas; Bailly, Patrice; Jacquet, Jean-François

    2015-07-01

    The objective of the study is to better understand how blunt projectile ballistic parameters and material properties influence the events leading to injuries. The present work focuses on lateral thoracic impacts and follows an experimental approach. The projectiles are made with a soft foam nose assembled with a rigid rear plastic part. The dynamic properties of the foams were first determined using the Split Hopkinson Pressure Bar (SHPB) system. The impact forces on a rigid wall were then measured to provide reference load data. Lastly, shots were made on isolated thoraxes of porcine cadavers to investigate the response in the vicinity of the impact (wall displacements, rib accelerations and strains, rib fractures). Results show that the severity of the response appears to be mainly correlated with the impulse and with the pre-impact momentum.

  5. Analysis of the ballistic impact response of a composite material using FAST Infrared Imagery

    Science.gov (United States)

    Marcotte, Frederick; Ouellet, Simon; Farley, Vincent

    2013-05-01

    The level of protection offered by a given ballistic material is typically evaluated in terms of a set of projectiles and their associated velocity at which a certain percentage of the projectiles are expected to perforate. (i.e. FSP 17gr : V50 = 500m/s, 9mm FMJ; V0=500m/s). These metrics give little information about the physical phenomena by which energy is dispersed, spread or absorbed in a specific target material. Aside from post-test inspection of the impacted material, additional information on the target response is traditionally obtained during a test from the use of high speed imaging, whether it is from a single camera aimed at the impact surface or the backface, or from a set of camera allowing full 3-D reconstruction of a deformed surface. Again, this kind of data may be difficult to interpret if the interest is in the way energy is managed in the target in real time. Recent technological progress in scientific grade high-speed infrared (IR) camera demonstrated that these phenomena can straightforwardly be measured using IR thermal imaging. This paper presents promising results obtained from Telops FAST-IR 1500 infrared camera on an aramid-based ballistic composite during an impact from a small caliber fragment simulating projectile (FSP).

  6. Ballistic impact behavior of carbon nanotube and nanosilica dispersed resin and composites

    Science.gov (United States)

    Pandya, K. S.; Akella, K.; Joshi, M.; Naik, N. K.

    2012-12-01

    Experimental studies are presented on the ballistic impact behavior of nanoparticle dispersed materials viz. symmetric balanced cross-ply laminates made using unidirectional E-glass fabric with epoxy resin and neat epoxy resin. The nanoparticles used are nanosilica and multi-walled carbon nanotube for polymer matrix composites and nanosilica for epoxy resin. For comparison, studies are carried out on symmetric balanced cross-ply E-glass/epoxy and neat epoxy resin without nanoparticles. Effect of nanoparticle dispersion on ballistic limit velocity, V50 and energy absorbed has been studied. It is observed that V50 can be enhanced up to 6.3% for polymer matrix composites and up to 7.3% for neat resin on addition of nanoparticles. Also, energy absorbed can be increased up to 13.0% for polymer matrix composites and up to 15.2% for neat resin on addition of nanoparticles. Damage and energy absorbing mechanisms for different types of materials studied is also presented. Further, it is observed that the damage size on the target around the point of impact decreases on addition of nanoparticles. Quantitative data are given for high velocity impact behavior of the five types of specimens studied.

  7. Metallographic characterisation of Al6061-T6 aluminium plates subjected to ballistic impact

    Energy Technology Data Exchange (ETDEWEB)

    Manes, A., E-mail: andrea.manes@polimi.it; Pagani, M.; Saponara, M.; Mombelli, D.; Mapelli, C.; Giglio, M.

    2014-07-01

    Al6061-T6 aluminium single layer plates, of different thickness, impacted by two different 7.62 mm Armour Piercing projectiles are studied from a metallographic point of view. The material behaviour after ballistic impact is investigated by optical and scanning electron microscopy as well as by micro-hardness tests. The study allows one to highlight the physical phenomena that happen during the impact: the formation of adiabatic shear bands (ASB), the evolution of softening and hardening phenomena, the creation of petalling, plugging and the formation of a melted film between the target and the penetrator as well as the localised failure mechanism. The thermo-mechanical effects on the target and the penetrator material have been examined in order to investigate in the physical phenomena ruling the ballistic damage; the differences between the two types of impactors are also highlighted. Among interesting findings, it has been noticed that a complete penetration is less detrimental and tungsten core projectile seems more damaging for the structural integrity of Al6061-T6 plates. A complete penetration allows the material to better dissipate the plastic deformation energy induced by bullet whereas the arrest increases localised material softening effect resulting in the formation of ASB. Although the creation of numerical models is not the aim of the present paper, the findings could be useful for the building of a modelling approach capable of replicating all the involved phenomena in details.

  8. A computational study of influence of helmet padding materials on the human brain under ballistic impacts.

    Science.gov (United States)

    Salimi Jazi, Mehdi; Rezaei, Asghar; Karami, Ghodrat; Azarmi, Fardad; Ziejewski, Mariusz

    2014-01-01

    The results of a computational study of a helmeted human head are presented in this paper. The focus of the work is to study the effects of helmet pad materials on the level of acceleration, inflicted pressure and shear stress in a human brain model subjected to a ballistic impact. Four different closed cell foam materials, made of expanded polystyrene and expanded polypropylene, are examined for the padding material. It is assumed that bullets cannot penetrate the helmet shell. Finite element modelling of the helmet, padding system, head and head components is used for this dynamic nonlinear analysis. Appropriate contacts and conditions are applied between the different components of the head, as well as between the head and the pads, and the pads and the helmet. Based on the results of simulations in this work, it is concluded that the stiffness of the foam has a prominent role in reducing the level of the transferred load to the brain. A pad that is less stiff is more efficient in absorbing the impact energy and reducing the sudden acceleration of the head and consequently lowers the brain injury level. Using the pad with the least stiffness, the influence of the angle of impacts as well as the locations of the ballistic strike is studied.

  9. Densification and Devitrification of Fused Silica Induced by Ballistic Impact: A Computational Investigation

    Directory of Open Access Journals (Sweden)

    Mica Grujicic

    2015-01-01

    Full Text Available A molecular-level computational investigation is carried out to determine the dynamic response and material topology changes of fused silica subjected to ballistic impact by a hard projectile. The analysis was focused on the investigation of specific aspects of the dynamic response and of the topological changes such as the deformation of highly sheared and densified regions, and the conversion of amorphous fused silica to SiO2 crystalline polymorphs (in particular, α-quartz and stishovite. The topological changes in question were determined by carrying out a postprocessing atom-coordination procedure. This procedure suggested the formation of stishovite (and perhaps α-quartz within fused silica during ballistic impact. To rationalize the findings obtained, the all-atom molecular-level computational analysis is complemented by a series of quantum-mechanics density functional theory (DFT computations. The latter computations enable determination of the relative potential energies of the fused silica, α-quartz and stishovite, under ambient pressure (i.e., under their natural densities as well as under imposed (as high as 50 GPa pressures (i.e., under higher densities and shear strains. In addition, the transition states associated with various fused-silica devitrification processes were identified. The results obtained are found to be in good agreement with their respective experimental counterparts.

  10. Response Simulation of a Micro Reinforced Concrete Target Under Ballistic Impact

    Science.gov (United States)

    Mohan, V.; Rajasankar, J.; Iyer, N. R.

    2014-05-01

    The response of concrete structures subjected to impact loading has received extensive attention in both civil and military applications. Research on improving the shock resistance of concrete has led to the development of cementitious composites. Micro Reinforced Concrete (MRC), a type of cementitious composite, is a concrete matrix embedded with multilayered steel wire meshes. This paper presents 3D hydrocode simulations of MRC panels subjected to impact under a ballistic range. A finite element model based on Lagrange formulation is used to represent both a 300 mm × 300 mm × 100 mm target with 30 layers of wire mesh and a 5.56 × 45 mm projectile in simulations. Penetration depth and damage patterns of the MRC mesh cement composite panel are numerically compared with those of the field experiment. The results show a relatively good agreement.

  11. Wound Ballistics Modeling for Blast Loading Blunt Force Impact and Projectile Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Paul A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cooper, Candice Frances [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Burnett, Damon J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is virtually nonexistent but necessary to ensure adequate protection against injury to the heart and lungs. In this report, we discuss the development of a high-fidelity human torso model, it's merging with the existing Sandia Human Head-Neck Model, and development of the modeling & simulation (M&S) capabilities necessary to simulate wound injury scenarios. Using the new Sandia Human Torso Model, we demonstrate the advantage of virtual simulation in the investigation of wound injury as it relates to the warfighter experience. We present the results of virtual simulations of blast loading and ballistic projectile impact to the tors o with and without notional protective armor. In this manner, we demonstrate the ad vantages of applying a modeling and simulation approach to the investigation of wound injury and relative merit assessments of protective body armor without the need for trial-and-error testing.

  12. Ballistic Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Ballistic Test Facility is comprised of two outdoor and one indoor test ranges, which are all instrumented for data acquisition and analysis. Full-size aircraft...

  13. Forensic Evidence and Criminal Investigations: The Impact of Ballistics Information on the Investigation of Violent Crime in Nine Cities().

    Science.gov (United States)

    King, William R; Campbell, Bradley A; Matusiak, Matthew C; Katz, Charles M

    2017-01-23

    We explore the impact of information from ballistics imaging hit reports on the investigation into violent crimes. Ballistics imaging hits link two crimes involving the same firearm by forensically matching tool marks on the fired bullets or cartridge cases. Interview data collected from detectives who received a hit report were used to explore the relationship between the presence of a hit report and outcomes in 65 gun-related violent crime investigations in nine U.S. police agencies. Findings indicate hit reports rarely contribute to identification, arrest, charging, or sentencing of suspects, because of delays in producing hit reports. On average, hit reports were completed 181.4 days after the focal crime. This delay forces investigations to proceed without the benefit of information from ballistics analysis. Additionally, hit reports rarely contained detailed information that was immediately useful to investigators. Instead, hit reports required additional research by the investigator to unlock useful information.

  14. Analysis of injury criteria to assess chest and abdominal injury risks in blunt and ballistic impacts.

    Science.gov (United States)

    Sturdivan, Larry M; Viano, David C; Champion, Howard R

    2004-03-01

    The Viscous Criterion (VC) is an experimental measure developed by the automotive industry to assess injury risks for high-speed impacts. The Blunt Criterion (BC) is a prospective measure developed by the Department of Defense to predict injury from blunt projectiles. The range of applicability of BC was extended and compared with VC for its ability to assess injury risk using published cadaver and animal data. Department of Defense projectiles were 0.05 to 0.43 kg mass at velocities up to 86 m/s. VC data were generated from impacts with 1.75 to 23.4 kg at 3.6 to 10.2 m/s. Chest and abdominal injuries ranged from Abbreviated Injury Scale scores of 1 to 6. Both criteria correlated very well with the experimental data, demonstrating correlation coefficients of R = 0.84 to 0.96. The correlation between VC and BC was R = 0.99. Logistic probability curves were derived to predict blunt impact injuries of Abbreviated Injury Scale scores of 1 to 6 for the chest and abdomen. BC and VC are virtually identical in their ability to assess blunt and ballistic impact injury risks. They are different measures of impact energy absorbed by the body. One is predictive using input parameters, and the other measures the impact response of the body.

  15. Ground impact probability distribution for small unmanned aircraft in ballistic descent

    DEFF Research Database (Denmark)

    La Cour-Harbo, Anders

    2017-01-01

    Safety is a key factor in all aviation, and while years of development has made manned aviation relatively safe, the same has yet to happen for unmanned aircraft. However, the rapid development of unmanned aircraft technology means that the range of commercial and scientific applications is growing...... equally rapid. At the same time the trend in national and international regulations for unmanned aircraft is to take a risk-based approach, effectively requiring risk assessment for every flight operation. This work addresses the growing need for methods for quantitatively evaluating individual flights...... by modelling the consequences of a ballistic descent of an unmanned aircraft as a result of a major inflight incident. The presented model is a probability density function for the ground impact area based on a second order drag model with probabilistic assumptions on the least well-known parameters...

  16. Ballistic Impact Response of Ceramic-Faced Aramid Laminated Composites Against 7.62 mm Armour Piercing Projectiles

    Directory of Open Access Journals (Sweden)

    Nityananda Nayak

    2013-07-01

    Full Text Available Ballistic impact response of ceramic- composite armor, consisting of zirconia toughened alumina (ZTA ceramic front and aramid laminated composite as backing, against 7.62 mm armor piercing (AP projectiles has been studied. Two types of backing composite laminates i.e. Twaron-epoxy and Twaron-polypropylene (PP of 10 mm and 15 mm thickness were used with a ceramic face of 4mm thick ZTA. The ceramic- faced and the stand alone composite laminates were subjected to ballistic impact of steel core 7.62 mm AP projectiles with varying impact velocities and their V50 ballistic limit (BL was determined. A sharp rise in BL was observed due to addition of ceramic front layer as compared to stand alone ones. The impact energy was absorbed during penetration primarily by fracture of ceramic, deformation and fracture of projectile and elastic-plastic deformation of flexible backing composite layer. The breaking of ceramic tiles were only limited to impact area and did not spread to whole surface and projectile shattering above BL and blunting on impact below BL was observed. The ceramic- faced composites showed higher BL with Twaron-PP as backing than Twaron-epoxy laminate of same thickness. This combination of ceramic-composite laminates exhibited better multi-hit resistance capability; ideal for light weight armor.Defence Science Journal, 2013, 63(4, pp.369-375, DOI:http://dx.doi.org/10.14429/dsj.63.2616

  17. Effects of Various Heat Treatments on the Ballistic Impact Properties of Inconel 718 Investigated

    Science.gov (United States)

    Pereira, J. Michael; Lerch, Bradley A.

    2000-01-01

    Uncontained failures of aircraft engine fan blades are serious events that can cause equipment damage and loss of life. Federal Aviation Administration (FAA) certification requires that all engines demonstrate the ability to contain a released fan blade with the engine running at full power. However, increased protection generally comes at the expense of weight. Proper choice of materials is therefore imperative to an optimized design. The process of choosing a good casing material is done primarily through trial and error. This costly procedure could be minimized if there was a better understanding of the relationships among static material properties, impact properties, and failure mechanisms. This work is part of a program being conducted at the NASA Glenn Research Center at Lewis Field to study these relationships. Ballistic impact tests were conducted on flat, square sheets of Inconel 718 that had been subjected to different heat treatments. Two heat treatments and the as-received condition were studied. In addition, results were compared with those from an earlier study involving a fourth heat treatment. The heat treatments were selected on the basis of their effects on the static tensile properties of the material. The impact specimens used in this study were 17.8-cm square panels that were centered and clamped over a 15.2-cm square hole in a 1.27-cm-thick steel plate. Three nominal plate thickness dimensions were studied, 1.0, 1.8, and 2.0 mm. For each thickness, all the specimens were taken from the same sheet of material. The projectile was a Ti-6Al-4V cylinder with a length of 25.4 mm, a diameter of 12.7 mm, and a mass ranging from 14.05 to 14.20 g. The projectiles were accelerated toward the specimens at normal incidence using a gas gun with a 2-m-long, 12.7-mm inner-diameter barrel. The ballistic limit for each heat treatment condition and thickness was determined by conducting a number of impact tests that bracketed as closely as possible the velocity

  18. Models of the SL9 Impacts I. Ballistic Monte-Carlo Plume

    CERN Document Server

    Harrington, J; Harrington, Joseph; Deming, Drake

    2001-01-01

    We model the Comet Shoemaker-Levy 9 - Jupiter impact plumes to calculate synthetic plume views, atmospheric infall fluxes, and debris patterns. Our plume is a swarm of ballistic particles with one of several mass-velocity distributions (MVD). The swarm is ejected instantaneously and uniformly into a cone from its apex. Upon falling to the ejection altitude, particles slide with horizontal deceleration following one of several schemes. The model ignores hydrodynamic and Coriolis effects. We adjust plume tilt, opening angle, and minimum velocity, and choose MVD and sliding schemes, to create impact patterns that match observations. Our best match uses the power-law MVD from the numerical impact model of Zahnle and Mac Low, with velocity cutoffs at 4.5 and 11.8 km/sec, cone opening angle of 75 degrees, cone tilt of 30 degrees from vertical, and a sliding constant deceleration of 1.74 m/sec^2. A mathematically-derived feature of Zahnle and Mac Low's published cumulative MVD is a thin shell of mass at the maximum ...

  19. Hybrid carbon-glass fiber/toughened epoxy thick composites subject to drop-weight and ballistic impacts

    Science.gov (United States)

    Sevkat, Ercan

    The goals of this study are to investigate the low velocity and ballistic impact response of thick-section hybrid fiber composites at room temperature. Plain-woven S2-Glass and IM7 Graphite fabrics are chosen as fiber materials reinforcing the SC-79 epoxy. Four different types of composites consisting of alternating layers of glass and graphite woven fabric sheets are considered. Tensile tests are conducted using 98 KN (22 kip) MTS testing machine equipped with environmental chamber. Low-velocity impact tests are conducted using an Instron-Dynatup 8250 impact test machine equipped with an environmental chamber. Ballistic impact tests are performed using helium pressured high-speed gas-gun. Tensile tests results were used to define the material behavior of the hybrid and non-hybrid composites in Finite Element modeling. The low velocity and ballistic impact tests showed that hybrid composites performance was somewhere between non-hybrid woven composites. Using woven glass fabrics as outer skin improved the impact performance of woven graphite composite. However hybrid composites are prone to delamination especially between dissimilar layers. The ballistic limit velocity V50 hybrid composites were higher that of woven graphite composite and lower than that of woven glass composite. Both destructive cross-sectional micrographs and nondestructive ultrasonic techniques are used to evaluate the damage created by impact. The Finite Element code LS-DYNA is chosen to perform numerical simulations of low velocity and ballistic impact on thick-section hybrid composites. The damage progression in these composites shows anisotropic nonlinearity. The material model to describe this behavior is not available in LS-DYNA material library. Initially, linear orthotropic material with damage (Chan-Chan Model) is employed to simulate some of the experimental results. Then, user-defined material subroutine is incorporated into LS-DYNA to simulate the nonlinear behavior. The

  20. Ballisticians in War and Peace. A History of the United States Army Ballistic Research Laboratories. Volume 1. 1914-1956,

    Science.gov (United States)

    1956-01-01

    Arrangements were made with the University of Delaware staff to teach all COL Charles L. Register. Director of BRL 1956 the desired courses, with the...containing various experi- 77 ballistic research, 1946 to 1956 INTERIOR BALLISTICS IN THE POSTWAR YEARS mental additives, study of the thermochemistry of

  1. Ballistic Impact Response of Kevlar 49 and Zylon under Conditions Representing Jet Engine Fan Containment

    Science.gov (United States)

    Pereira, J. Michael; Revilock, Duane M.

    2007-01-01

    A ballistic impact test program was conducted to provide validation data for the development of numerical models of blade out events in fabric containment systems. The impact response of two different fiber materials - Kevlar 49 (E.I. DuPont Nemours and Company) and Zylon AS (Toyobo Co., Ltd.) was studied by firing metal projectiles into dry woven fabric specimens using a gas gun. The shape, mass, orientation and velocity of the projectile were varied and recorded. In most cases the tests were designed such that the projectile would perforate the specimen, allowing measurement of the energy absorbed by the fabric. The results for both Zylon and Kevlar presented here represent a useful set of data for the purposes of establishing and validating numerical models for predicting the response of fabrics under conditions simulating those of a jet engine blade release situation. In addition some useful empirical observations were made regarding the effects of projectile orientation and the relative performance of the different materials.

  2. Simulation of depth of penetration during ballistic impact on thick targets using a one-dimensional discrete element model

    Indian Academy of Sciences (India)

    Rajesh P Nair; C Lakshmana Rao

    2012-04-01

    One-dimensional discrete element model for the ballistic impact is used to determine the depth of penetration of a bullet on a thick target. Discrete Element Method (DEM) is a numerical tool where a continuum is modelled as a network of masses connected by normal springs. A one-dimensional discrete element model is developed to obtain the displacements and forces associated with the ballistic impact on a thick target. The depth of penetration of the penetrator into the target is calculated from these DEM results. The simulated results of depth of penetration are found to be in reasonable agreement with the simulation results of other numerical approaches that are available in the literature.

  3. Analysis of Energy Dissipation Mechanisms of Woven Fabrics Subjected to Ballistic Impact

    OpenAIRE

    IŞIK, Halil; DEĞİRMENCİ, Ercan; EVCİ, Celal

    2013-01-01

    It is important for combat vehicles and technological defense systems used in the battlefield to be lightweight for maneuverability while they still provide effective protection for survivability. Desired ballistic protection of defense systems may be attained by armor systems developed with different materials. The most important factor in the design of armor is the optimization of ballistic protection/weight ratio. The protection degree needed for sufficient survivability is limited by the ...

  4. Graphical User Interface (GUI) Design for Ballistic Research Laboratory-Computer-Aided Design’s (BRL-CAD’s) Geometry Difference (GDiff) Tool

    Science.gov (United States)

    2015-04-01

    Graphical User Interface ( GUI ) Design for Ballistic Research Laboratory–Computer-Aided Design’s (BRL–CAD’s) Geometry Difference (GDiff) Tool...to the originator. Army Research Laboratory Aberdeen Proving Ground, MD 21005 ARL-CR-0756 April 2015 Graphical User Interface ( GUI ...2015 2. REPORT TYPE Contractor Report 3. DATES COVERED (From - To) 06/2014–08/2014 4. TITLE AND SUBTITLE Graphical User Interface ( GUI ) Design for

  5. Modeling and Experiments on Ballistic Impact into UHMWPE Yarns Using Flat and Saddle-Nosed Projectiles

    Directory of Open Access Journals (Sweden)

    Stuart Leigh Phoenix

    2017-03-01

    Full Text Available Yarn shooting experiments were conducted to determine the ballistically-relevant, Young’s modulus and tensile strength of ultra-high molecular weight polyethylene (UHMWPE fiber. Target specimens were Dyneema® SK76 yarns (1760 dtex, twisted to 40 turns/m, and initially tensioned to stresses ranging from 29 to 2200 MPa. Yarns were impacted, transversely, by two types of cylindrical steel projectiles at velocities ranging from 150 to 555 m/s: (i a reverse-fired, fragment simulating projectile (FSP where the flat rear face impacted the yarn rather than the beveled nose; and (ii a ‘saddle-nosed projectile’ having a specially contoured nose imparting circular curvature in the region of impact, but opposite curvature transversely to prevent yarn slippage off the nose. Experimental data consisted of sequential photographic images of the progress of the triangular transverse wave, as well as tensile wave speed measured using spaced, piezo-electric sensors. Yarn Young’s modulus, calculated from the tensile wave-speed, varied from 133 GPa at minimal initial tension to 208 GPa at the highest initial tensions. However, varying projectile impact velocity, and thus, the strain jump on impact, had negligible effect on the modulus. Contrary to predictions from the classical Cole-Smith model for 1D yarn impact, the critical velocity for yarn failure differed significantly for the two projectile types, being 18% lower for the flat-faced, reversed FSP projectile compared to the saddle-nosed projectile, which converts to an apparent 25% difference in yarn strength. To explain this difference, a wave-propagation model was developed that incorporates tension wave collision under blunt impact by a flat-faced projectile, in contrast to outward wave propagation in the classical model. Agreement between experiment and model predictions was outstanding across a wide range of initial yarn tensions. However, plots of calculated failure stress versus yarn pre

  6. Terminal ballistics

    CERN Document Server

    Rosenberg, Zvi

    2016-01-01

    This book comprehensively discusses essential aspects of terminal ballistics, combining experimental data, numerical simulations and analytical modeling. Employing a unique approach to numerical simulations as a measure of sensitivity for the major physical parameters, the new edition also includes the following features: new figures to better illustrate the problems discussed; improved explanations for the equation of state of a solid and for the cavity expansion process; new data concerning the Kolsky bar test; and a discussion of analytical modeling for the hole diameter in a thin metallic plate impacted by a shaped charge jet. The section on thick concrete targets penetrated by rigid projectiles has now been expanded to include the latest findings, and two new sections have been added: one on a novel approach to the perforation of thin concrete slabs, and one on testing the failure of thin metallic plates using a hydrodynamic ram.

  7. Effects of Heat Treatment on the Ballistic Impact Properties of Inconel 718 for Jet Engine Fan Containment Applications

    Science.gov (United States)

    Pereira, J. Michael; Lerch, Bradley A.

    2001-01-01

    The effects of heat treating Inconel 718 on the ballistic impact response and failure mechanisms were studied. Two different annealing conditions and an aged condition were considered. Large differences in the static properties were found between the annealed and the aged material, with the annealed condition having lower strength and hardness and greater elongation than the aged. High strain rate tests show similar results. Correspondingly large differences were found in the velocity required to penetrate material in the two conditions in impact tests involving 12.5 mm diameter, 25.4 mm long cylindrical Ti-6-4 projectiles impacting flat plates at velocities in the range of 150 to 300 m/sec. The annealed material was able to absorb over 25 percent more energy than the aged. This is contrary to results observed for ballistic impact response for higher velocity impacts typically encountered in military applications where it has been shown that there exists a correlation between target hardness and ballistic impact strength. Metallographic examination of impacted plates showed strong indication of failure due to adiabatic shear. In both materials localized bands of large shear deformation were apparent, and microhardness measurements indicated an increase in hardness in these bands compared to the surrounding material. These bands were more localized in the aged material than in the annealed material. In addition the annealed material underwent significantly greater overall deformation before failure. The results indicate that lower elongation and reduced strain hardening behavior lead to a transition from shear to adiabatic shear failure, while high elongation and better strain hardening capabilities reduce the tendency for shear to localize and result in an unstable adiabatic shear failure. This supports empirical containment design methods that relate containment thickness to the static toughness.

  8. Morphoscopic analysis of experimentally produced bony wounds from low-velocity ballistic impact.

    Science.gov (United States)

    Kieser, Jules A; Tahere, Joy; Agnew, Caitlin; Kieser, David C; Duncan, Warwick; Swain, Michael V; Reeves, Matthew T

    2011-12-01

    Understanding how bone behaves when subjected to ballistic impact is of critical importance for forensic questions, such as the reconstruction of shooting events. Yet the literature addressing microscopic anatomical features of gunshot wounds to different types of bone is sparse. Moreover, a biomechanical framework for describing how the complex architecture of bone affects its failure during such impact is lacking. The aim of this study was to examine the morphological features associated with experimental gunshot wounds in slaughtered pig ribs. We shot the 4th rib of 12 adult pigs with .22 mm subsonic bullets at close range (5 cm) and examined resultant wounds under the light microscope, scanning electron microscope SEM and micro tomograph μCT. In all cases there was a narrow shot channel followed by spall region, with evidence of plastic deformation with burnishing of the surface bone in the former, and brittle fracture around and through individual Haversian systems in the latter. In all but one case, the entrance wounds were characterized by superficially fractured cortical bone in the form of a well-defined collar, while the exit wounds showed delamination of the periosteum. Inorganic residue was evident in all cases, with electron energy dispersive spectroscopy EDS confirming the presence of carbon, phosphate, lead and calcium. This material appeared to be especially concentrated within the fractured bony collar at the entrance. We conclude that gunshot wounds in flat bones may be morphologically divided into a thin burnished zone at the entry site, and a fracture zone at the exit.

  9. Effect of Mesoscale and Multiscale Modeling on the Performance of Kevlar Woven Fabric Subjected to Ballistic Impact: A Numerical Study

    Science.gov (United States)

    Jia, Xin; Huang, Zhengxiang; Zu, Xudong; Gu, Xiaohui; Xiao, Qiangqiang

    2013-12-01

    In this study, an optimal finite element model of Kevlar woven fabric that is more computational efficient compared with existing models was developed to simulate ballistic impact onto fabric. Kevlar woven fabric was modeled to yarn level architecture by using the hybrid elements analysis (HEA), which uses solid elements in modeling the yarns at the impact region and uses shell elements in modeling the yarns away from the impact region. Three HEA configurations were constructed, in which the solid element region was set as about one, two, and three times that of the projectile's diameter with impact velocities of 30 m/s (non-perforation case) and 200 m/s (perforation case) to determine the optimal ratio between the solid element region and the shell element region. To further reduce computational time and to maintain the necessary accuracy, three multiscale models were presented also. These multiscale models combine the local region with the yarn level architecture by using the HEA approach and the global region with homogenous level architecture. The effect of the varying ratios of the local and global area on the ballistic performance of fabric was discussed. The deformation and damage mechanisms of fabric were analyzed and compared among numerical models. Simulation results indicate that the multiscale model based on HEA accurately reproduces the baseline results and obviously decreases computational time.

  10. Ballistic impact damage and penetration mechanics of fiber-reinforced composite laminates

    Science.gov (United States)

    Patts, Henry Michael

    2000-10-01

    Experimental and theoretical studies were performed to characterize and model the processes of damage evolution and resulting penetration failure of graphite fiber-reinforced epoxy resin composite laminates ("structural grade") under ballistic impact. In contrast to the local yielding demonstrated by ductile isotropic materials, the penetration failure of fiber-reinforced composites produced extensive fragmentation of material with multiple modes of damage propagation such as "delamination," "interfiber matrix splitting," "transverse fiber cuts," and "through-the-thickness plugging." Due to the formation of damage zones in three-dimensional scale, the increase in target thickness raised the amount of kinetic energy absorption for full penetration in a "non-linear" fashion in fiber composites unlike the linear correlation for isotropic material such as polycarbonate and aluminum. Interfiber matrix splitting and delamination were found to be the first sign of structural deterioration occurring far below V50 and precede transverse cutting of fibers and plugging. The development of interfiber splitting into delamination of composites is explained by relying on the contact mechanics of a spherical indentor. Matrix splits on adjacent plies formed one pair of geometrical "wedges" at the ply interface, resulting in a delamination zone connected through an "isthmus." Contained in this free ply region, stress concentration readily led to transverse cutting (approximately at 85 percent of the V50) of plies when longitudinal stress of the reinforcing fibers reaches a critical level for fracture. The observed distribution of the damage leading to transverse fiber cuts was modeled by idealizing a circular target panel of staircase laminate into three zones with different values of bending stiffness due to the progression of damage. In "three-zone" model, the energy absorbed by the panel were represented in three forms of potential energy; surface free energy due to delamination

  11. Ballistic Impact Behavior of Nacre-Like Laminated Composites Consisting of B4C Tablets and Polyurea Matrix

    Science.gov (United States)

    Grujicic, M.; Snipes, J. S.; Ramaswami, S.

    2016-03-01

    A nacre-like composite armor consisting of B4C tablets and polyurea matrix is modeled, and its ballistic impact behavior and penetration resistance (under a normal and a 15°-oblique impact by a solid right circular cylindrical projectile) were analyzed using a series of transient, nonlinear dynamic, finite-element analyses. Nacre is a biological material constituting the innermost layer of the shells of gastropods and bivalves. It consists of polygonal tablets of aragonite, tessellated to form individual layers and having the adjacent layers as well as the tablets within a layer bonded by a biopolymer. Due to its highly complex hierarchical microstructure, nacre possesses an outstanding combination of mechanical properties, the properties which are far superior to the ones that are predicted using the homogenization techniques such as the rule of mixtures. The results of the transient nonlinear dynamic analysis pertaining to the ballistic impact response and the penetration resistance of the modeled nacre-like armor are compared with their counterparts for the B4C single-block armor having an identical areal density. Furthermore, the effect of various nacre microstructural features (e.g., surface profiling, micron-scale asperities, mineral bridges between the overlapping tablets lying in adjacent layers) on the ballistic penetration resistance of the nacre-like composite armor is investigated in order to identify an optimal nacre-like composite-armor architecture having the largest penetration resistance. The results obtained clearly show that a nacre-like armor possesses a superior penetration resistance relative to its monolithic counterpart, and that the nacre microstructural features considered play a critical role in the armor penetration resistance.

  12. A new experimental setup to characterize the dynamic mechanical behaviour of ballistic yarns

    Science.gov (United States)

    Chevalier, C.; Kerisit, C.; Boussu, F.; Coutellier, D.; Faderl, N.; Klavzar, A.

    2016-10-01

    Fabrics have been widely used as part of ballistic protections since the 1970s and the development of new ballistic solutions made from fabrics need numerical simulations, in order to predict the performance of the ballistic protection. The performances and the induced mechanisms in ballistic fabrics during an impact depend on the weaving parameters and also on the inner parameters of the yarns used inside these structures. Thus, knowing the dynamic behaviour of yarn is essential to determine the ballistic behaviour of fabrics during an impact. Two major experimental devices exist and are used to test ballistic yarns in a dynamic uniaxial tension. The first one corresponds to the Split Hopkinson Tensile Bars device, which is commonly used to characterize the mechanical properties of materials in uniaxial tension and under high loading. The second one is the transversal impact device. The real conditions of ballistic impact can be realized with this device. Then, this paper deals with a new experimental setup developed in our laboratory and called the ‘tensile impact test for yarn’ (TITY) device. With this device, specific absorbed energy measurements of para-aramid yarns (336 Tex, Twaron™, 1000 filaments) have been carried out and revealed that static and dynamic properties of para-aramid are different.

  13. FAA Development of Reliable Modeling Methodologies for Fan Blade Out Containment Analysis. Part 2; Ballistic Impact Testing

    Science.gov (United States)

    Revilock, Duane M.; Pereira, J. Michael

    2008-01-01

    This report summarizes the ballistic impact testing that was conducted to provide validation data for the development of numerical models of blade out events in fabric containment systems. The ballistic impact response of two different fiber materials - Kevlar 49 (E.I. DuPont Nemours and Company) and Zylon AS (Toyobo Co., Ltd.) was studied by firing metal projectiles into dry woven fabric specimens using a gas gun. The shape, mass, orientation and velocity of the projectile were varied and recorded. In most cases the tests were designed such that the projectile would perforate the specimen, allowing measurement of the energy absorbed by the fabric. The results for both Zylon and Kevlar presented here represent a useful set of data for the purposes of establishing and validating numerical models for predicting the response of fabrics under conditions simulating those of a jet engine blade release situations. In addition some useful empirical observations were made regarding the effects of projectile orientation and the relative performance of the different materials.

  14. Capabilities of Helmets for Preventing Head Injuries Induced by Ballistic Impacts

    Directory of Open Access Journals (Sweden)

    D.V. Balandin

    2004-01-01

    Full Text Available The limiting performance of ballistically loaded helmets designed to reduce head injuries is studied analytically. The projectile does not penetrate the helmet. This analysis evaluates the absolute minimum of the peak displacement of the helmet shell relative to the head, provided that criteria measuring the severity of head injuries lie within prescribed limits. Rather than optimize a specific design configuration, e.g. a viscoelastic foam liner, characteristics of a time-dependent force representing the helmet liner are calculated. The formulation reduces the limiting performance analysis to an optimal control problem.

  15. Rain Erosion/Measurement Impact Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The FARM Rain Erosion/Impact Measurement Lab develops solutions for deficiencies in the ability of materials, coatings and designs to withstand a severe operational...

  16. Elevated Temperature Ballistic Impact Testing of PBO and Kevlar Fabrics for Application in Supersonic Jet Engine Fan Containment Systems

    Science.gov (United States)

    Pereira, J. Michael; Roberts Gary D.; Revilock, Duane M., Jr.

    1997-01-01

    Ballistic impact tests were conducted on fabric made from both Poly(phenylene benzobizoxazole) (PBO) and Kevlar 29 which were selected to be similar in weave pattern, areal density, and fiber denier. The projectiles were 2.54-cm- (1-in.-) long aluminum cylinders with a diameter of 1.27 cm (0.5 in.). The fabric specimens were clamped on four sides in a 30.5-cm- (12-in.-) square frame. Tests on PBO were conducted at room temperature and at 260 C (500 F). A number of PBO specimens were aged in air at 204 and 260 C (400 and 500 F) before impact testing. Kevlar specimens were tested only at room temperature and with no aging. The PBO absorbed significantly more energy than the Kevlar at both room and elevated temperatures. However, after aging at temperatures of 204 C (400 F) and above, the PBO fabric lost almost all of its energy absorbing ability. It was concluded that PBO fabric is not a feasible candidate for fan containment system applications in supersonic jet engines where operating temperatures exceed this level.

  17. Idaho National Laboratory Research & Development Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Stricker, Nicole [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-01-01

    Technological advances that drive economic growth require both public and private investment. The U.S. Department of Energy’s national laboratories play a crucial role by conducting the type of research, testing and evaluation that is beyond the scope of regulators, academia or industry. Examples of such work from the past year can be found in these pages. Idaho National Laboratory’s engineering and applied science expertise helps deploy new technologies for nuclear energy, national security and new energy resources. Unique infrastructure, nuclear material inventory and vast expertise converge at INL, the nation’s nuclear energy laboratory. Productive partnerships with academia, industry and government agencies deliver high-impact outcomes. This edition of INL’s Impacts magazine highlights national and regional leadership efforts, growing capabilities, notable collaborations, and technology innovations. Please take a few minutes to learn more about the critical resources and transformative research at one of the nation’s premier applied science laboratories.

  18. Ballistic Limit of High-Strength Steel and Al7075-T6 Multi-Layered Plates Under 7.62-mm Armour Piercing Projectile Impact

    OpenAIRE

    Rahman, N.A.; S. Abdullah; Zamri,W. F. H.; M. F. Abdullah; M. Z. Omar; Sajuri, Z.

    2016-01-01

    Abstract This paper presents the computational-based ballistic limit of laminated metal panels comprised of high strength steel and aluminium alloy Al7075-T6 plate at different thickness combinations to necessitate the weight reduction of existing armour steel plate. The numerical models of monolithic configuration, double-layered configuration and triple-layered configuration were developed using a commercial explicit finite element code and were impacted by 7.62 mm armour piercing projectil...

  19. Effect of microstructure on adiabatic shear band bifurcation in Ti–6Al–4V alloys under ballistic impact

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing Institute of Technology, Beijing 100081 (China); Yu, Xiaodong [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing Institute of Technology, Beijing 100081 (China); Laboratory of Advanced Materials Behavior Characteristics, Beijing Institute of Technology and Institute of Space Medico-Engineering, Beijing 100081 (China); Tan, Chengwen, E-mail: tanchengwen@126.com [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing Institute of Technology, Beijing 100081 (China); Laboratory of Advanced Materials Behavior Characteristics, Beijing Institute of Technology and Institute of Space Medico-Engineering, Beijing 100081 (China); Ma, Honglei [Laboratory of Advanced Materials Behavior Characteristics, Beijing Institute of Technology and Institute of Space Medico-Engineering, Beijing 100081 (China); Wang, Fuchi; Cai, Hongnian [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing Institute of Technology, Beijing 100081 (China)

    2014-02-10

    Adiabatic shear band (ASB) bifurcations in Ti–6Al–4V alloys with equiaxed, bimodal, and lamellar microstructures under ballistic impact were studied using transmission electron microscopy (TEM). Focused ion beam (FIB) technology was used to accurately prepare TEM samples in the ASB regions, which contained the regions in front of the ASB bifurcation, behind the ASB bifurcation, and the bifurcation regions. ASB consisted of dynamically recrystallized equiaxed grains and incompletely and dynamically recrystallized striped subgrains. ASB bifurcation occurred when the deformation incongruity between striped subgrains and surrounding equiaxed grains intensified sufficiently. Microstructure has an important effect on the number and morphology of ASB bifurcations. More ASB bifurcations formed in Ti–6Al–4V alloys with bimodal and lamellar microstructures than in the alloy with equiaxed microstructure because of the different amounts and distributions of striped subgrains. In the equiaxed microstructure, fewer subgrains were preserved in ASBs. Thus, forming deformation incongruities sufficiently intense to induce ASB bifurcation was difficult. In the bimodal microstructure, numerous striped subgrains and deformation incongruity locations were observed. More randomly distributed deformation incongruity locations would ultimately lead to more random ASB bifurcations. In the lamellar microstructure, the striped subgrains arranged along different directions in different colonies caused more intense deformation incongruity than when the subgrains were in the same colony. ASB bifurcation more commonly occurred at colony boundaries.

  20. Modeling the Ballistic Behavior of Solid Ejecta from the Deep Impact Cratering Event

    Science.gov (United States)

    Richardson, J. E.; Melosh, H. J.

    2006-03-01

    We describe results from a forward model of the first-order, solid ejecta particle behavior from the impact produced by the Deep Impact mission. The expansion rate of the plume places constraints on the gravity field, mass, and density of Tempel 1.

  1. Ballistic Rail Gun Soft Recovery Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Ballistic Rail Gun Soft Recovery Facility accommodates a 155mm Howitzer, fired horizontally into a 104-foot long water trough to slow the projectile and recover...

  2. Prediction of Behavior of Ceramic/Metal Composite Panels Under Two Consecutive Ballistic Impacts

    Science.gov (United States)

    Prakash, A.; Rajasankar, J.; Iyer, N. R.; Anandavalli, N.; Biswas, S. K.; Mukhopadhyay, A. K.

    2014-05-01

    This article presents a numerical investigation to predict the behavior of ceramic (Al2O3 99.5)/metal (Al5083 H116) composite panels under two consecutive high-velocity impacts of 7.62 mm sharp-nosed small projectiles. A numerical model is developed using the advanced nonlinear software AUTODYN. The aim of the study is to predict the impact behavior of ceramic/metal composite panels. The study mainly focuses on the effect of arrangement of front ceramic tiles having collinear and non-collinear joints on the impact damage pattern. The novelty of the study presented in this article is the prediction of high-velocity-impact response under two consecutive and closely spaced hits on composite panels carried out in a more realistic manner. Numerical responses, such as depth of penetration, and deformation in back plate and crack patterns, are found to match well with the experimental results. It is believed that the outcome of this study is helpful in the design of a ceramic tile joint arrangement to minimize damage in the target panel.

  3. Analysis of the Fragmentation of AlON and Spinel Under Ballistic Impact

    Science.gov (United States)

    2013-05-01

    Tests were conducted with each material at both impact veloc- ities, which were fully instrumented for high-speed photography. Three types of cameras...the projectile target interac- tion, crack propagation, and the onset of the ejection of fragments were visualized with an ultra-high-speed Shimadzu HPV

  4. Penetration resistance and ballistic-impact behavior of Ti/TiAl3 metal/intermetallic laminated composites (MILCs: A computational investigation

    Directory of Open Access Journals (Sweden)

    Jennifer S. Snipes

    2016-06-01

    Full Text Available A comprehensive computational engineering analysis is carried out in order to assess suitability of the Ti/TiAl3 metal/intermetallic laminated composites (MILCs for use in both structural and add-on armor applications. This class of composite materials consists of alternating sub-millimeter thick layers of Ti (the ductile and tough constituent and TiAl3 (the stiff and hard constituent. In recent years, this class of materials has been investigated for potential use in light-armor applications as a replacement for the traditional metallic or polymer-matrix composite materials. Within the computational analysis, an account is given to differing functional requirements for candidate materials when used in structural and add-on ballistic armor. The analysis employed is of a transient, nonlinear-dynamics, finite-element character, and the problem investigated involves normal impact (i.e. under zero obliquity angle of a Ti/TiAl3 MILC target plate, over a range of incident velocities, by a fragment simulating projectile (FSP. This type of analysis can provide more direct information regarding the ballistic limit of the subject armor material, as well as help with the identification of the nature and the efficacy of various FSP material-deformation/erosion and kinetic-energy absorption/dissipation phenomena and processes. The results obtained clearly revealed that Ti/TiAl3 MILCs are more suitable for use in add-on ballistic, than in structural armor applications.

  5. Friction Stir Weld Failure Mechanisms in Aluminum-Armor Structures Under Ballistic Impact Loading Conditions

    Science.gov (United States)

    2013-01-01

    Sheet) Continuation for Block 13 ARO Report Number Friction Stir Weld Failure Mechanisms in Alumin Block 13: Supplementary Note © 2013 . Published in...nose, steel jacketed, hard tungsten core (1400 Hv), armor piercing (AP) projectile (Ref 1). As mentioned above, this failure mechanism is often...zones being impacted with blunt, lower hardness projectiles [e.g., 20-mm caliber, 53 g, blunt, chamfered right circular cylindrical steel fragment

  6. Effect of Microscopic Damage Events on Static and Ballistic Impact Strength of Triaxial Braid Composites

    Science.gov (United States)

    Littell, Justin D.; Binienda, Wieslaw K.; Arnold, William A.; Roberts, Gary D.; Goldberg, Robert K.

    2010-01-01

    The reliability of impact simulations for aircraft components made with triaxial-braided carbon-fiber composites is currently limited by inadequate material property data and lack of validated material models for analysis. Methods to characterize the material properties used in the analytical models from a systematically obtained set of test data are also lacking. A macroscopic finite element based analytical model to analyze the impact response of these materials has been developed. The stiffness and strength properties utilized in the material model are obtained from a set of quasi-static in-plane tension, compression and shear coupon level tests. Full-field optical strain measurement techniques are applied in the testing, and the results are used to help in characterizing the model. The unit cell of the braided composite is modeled as a series of shell elements, where each element is modeled as a laminated composite. The braided architecture can thus be approximated within the analytical model. The transient dynamic finite element code LS-DYNA is utilized to conduct the finite element simulations, and an internal LS-DYNA constitutive model is utilized in the analysis. Methods to obtain the stiffness and strength properties required by the constitutive model from the available test data are developed. Simulations of quasi-static coupon tests and impact tests of a represented braided composite are conducted. Overall, the developed method shows promise, but improvements that are needed in test and analysis methods for better predictive capability are examined.

  7. Explicit Finite Element Modeling of Multilayer Composite Fabric for Gas Turbine Engine Containment Systems, Phase II. Part 2; Ballistic Impact Testing

    Science.gov (United States)

    Revilock, D. M.; Pereira, J. M.

    2009-01-01

    This report summarizes the ballistic impact testing that was conducted to provide validation data for the development of numerical models of blade-out events in fabric containment systems. The ballistic impact response of two different fiber materials - Kevlar(TradeName) 49 and Zylon(TradeName) AS (as spun) was studied by firing metal projectiles into dry woven fabric specimens using a gas gun. The shape, mass, orientation, and velocity of the projectile were varied and recorded. In most cases, the tests were designed so the projectile would perforate the specimen, allowing measurement of the energy absorbed by the fabric. The results for both Zylon and Kevlar presented here represent a useful set of data for the purposes of establishing and validating numerical models to predict the response of fabrics under conditions that simulate those of a jet engine blade-release situation. In addition, some useful empirical observations were made regarding the effects of projectile orientation and the relative performance of the different fabric materials.

  8. Assessment of Ballistic Performance for Transparent Material

    Directory of Open Access Journals (Sweden)

    Basim M. Fadhil

    2014-05-01

    Full Text Available A finite element method was used to investigate the ballistic behavior of Polymethylmethacrylate (PMMA under impact loading by spherical steel projectile with different ranges of velocities. Three different target thicknesses were used in the experimental and the numerical works. A mathematical model has been used for the ballistic limit based on the experimental results. It has been found that projectile velocity and target thickness play an important role in the ballistic behavior of PMMA. A good agreement was found between the numerical, experimental, and the analytical result.

  9. Failure analysis of high performance ballistic fibers

    OpenAIRE

    Spatola, Jennifer S

    2015-01-01

    High performance fibers have a high tensile strength and modulus, good wear resistance, and a low density, making them ideal for applications in ballistic impact resistance, such as body armor. However, the observed ballistic performance of these fibers is much lower than the predicted values. Since the predictions assume only tensile stress failure, it is safe to assume that the stress state is affecting fiber performance. The purpose of this research was to determine if there are failure mo...

  10. Failure analysis of high performance ballistic fibers

    OpenAIRE

    Spatola, Jennifer S

    2015-01-01

    High performance fibers have a high tensile strength and modulus, good wear resistance, and a low density, making them ideal for applications in ballistic impact resistance, such as body armor. However, the observed ballistic performance of these fibers is much lower than the predicted values. Since the predictions assume only tensile stress failure, it is safe to assume that the stress state is affecting fiber performance. The purpose of this research was to determine if there are failure mo...

  11. Novel Methods in Terminal Ballistics and Mechanochemistry of Damage: A Review of Developments at the US Army Research Laboratory, 2001-2007

    Science.gov (United States)

    2014-09-01

    fronts in brittle materials and their morphological instabilities. AIP Conference Proceedings . 2006;845(2):858–861. 17 25. Grinfeld MA...brittle ceramics and glasses. In: Glvez V, Sanchez-Galvez V, editors. Proceedings of the 23rd International Symposium on Ballistics; 2007... Conference ; 2002 Dec 2–5; Orlando, FL. 20. Grinfeld MA, Wright TW. Morphology of fractured domains in brittle fracture. Metallurgical and Materials

  12. Ballistic penetration test results for Ductal and ultra-high performance concrete samples.

    Energy Technology Data Exchange (ETDEWEB)

    Reinhart, William Dodd; Thornhill, Tom Finley, III (KTech)

    2010-03-01

    This document provides detailed test results of ballistic impact experiments performed on several types of high performance concrete. These tests were performed at the Sandia National Laboratories Shock Thermodynamic Applied Research Facility using a 50 caliber powder gun to study penetration resistance of concrete samples. This document provides test results for ballistic impact experiments performed on two types of concrete samples, (1) Ductal{reg_sign} concrete is a fiber reinforced high performance concrete patented by Lafarge Group and (2) ultra-high performance concrete (UHPC) produced in-house by DoD. These tests were performed as part of a research demonstration project overseen by USACE and ERDC, at the Sandia National Laboratories Shock Thermodynamic Applied Research (STAR) facility. Ballistic penetration tests were performed on a single stage research powder gun of 50 caliber bore using a full metal jacket M33 ball projectile with a nominal velocity of 914 m/s (3000 ft/s). Testing was observed by Beverly DiPaolo from ERDC-GSL. In all, 31 tests were performed to achieve the test objectives which were: (1) recovery of concrete test specimens for post mortem analysis and characterization at outside labs, (2) measurement of projectile impact velocity and post-penetration residual velocity from electronic and radiographic techniques and, (3) high-speed photography of the projectile prior to impact, impact and exit of the rear surface of the concrete construct, and (4) summarize the results.

  13. A model for evaluating the ballistic resistance of stratified packs

    Science.gov (United States)

    Pirvu, C.; Georgescu, C.; Badea, S.; Deleanu, L.

    2016-08-01

    Models for evaluating the ballistic performance of stratified packs are useful in reducing the time for laboratory tests, understanding the failure process and identifying key factors to improve the architecture of the packs. The authors present the results of simulating the bullet impact on a packs made of 24 layers, taking into consideration the friction between layers (μ = 0.4) and the friction between bullet and layers (μ = 0.3). The aim of this study is to obtain a number of layers that allows for the bullet arrest in the packs and to have several layers undamaged in order to offer a high level of safety for this kind of packs that could be included in individual armors. The model takes into account the yield and fracture limits of the two materials the bullet is made of and those for one layer, here considered as an orthotropic material, having maximum equivalent plastic strain of 0.06. All materials are considered to have bilinear isotropic hardening behavior. After documentation, the model was designed as isothermal because thermal influence of the impact is considered low for these impact velocities. The model was developed with the help of Ansys 14.5. Each layer has 200 mm × 200 × 0.35 mm. The bullet velocity just before impact was 400 m/s, a velocity characterizing the average values obtained in close range with a ballistic barrel and the bullet model is following the shape and dimensions of the 9 mm FMJ (full metal jacket). The model and the results concerning the number of broken layers were validated by experiments, as the number of broken layers for the actual pack (made of 24 layers of LFT SB1) were also seven...eight. The models for ballistic impact are useful when they are particularly formulated for resembling to the actual system projectile - target.

  14. The Truth About Ballistic Coefficients

    CERN Document Server

    Courtney, Michael

    2007-01-01

    The ballistic coefficient of a bullet describes how it slows in flight due to air resistance. This article presents experimental determinations of ballistic coefficients showing that the majority of bullets tested have their previously published ballistic coefficients exaggerated from 5-25% by the bullet manufacturers. These exaggerated ballistic coefficients lead to inaccurate predictions of long range bullet drop, retained energy and wind drift.

  15. Metamaterials for Ballistic Electrons

    CERN Document Server

    Dragoman, D; Dragoman, Daniela; Dragoman, Mircea

    2007-01-01

    The paper presents a metamaterial for ballistic electrons, which consists of a quantum barrier formed in a semiconductor with negative effective electron mass. This barrier is the analogue of a metamaterial for electromagnetic waves in media with negative electrical permittivity and magnetic permeability. Besides applications similar to those of optical metamaterials, a nanosized slab of a metamaterial for ballistic electrons, sandwiched between quantum wells of positive effective mass materials, reveals unexpected conduction properties, e.g. single or multiple room temperature negative differential conductance regions at very low voltages and with considerable peak-to-valley ratios, while the traversal time of ballistic electrons can be tuned to larger or smaller values than in the absence of the metamaterial slab. Thus, slow and fast electrons, analogous to slow and fast light, occur in metamaterials for ballistic electrons.

  16. Ballistic Response of Fabrics: Model and Experiments

    Science.gov (United States)

    Orphal, Dennis L.; Walker Anderson, James D., Jr.

    2001-06-01

    Walker (1999)developed an analytical model for the dynamic response of fabrics to ballistic impact. From this model the force, F, applied to the projectile by the fabric is derived to be F = 8/9 (ET*)h^3/R^2, where E is the Young's modulus of the fabric, T* is the "effective thickness" of the fabric and equal to the ratio of the areal density of the fabric to the fiber density, h is the displacement of the fabric on the axis of impact and R is the radius of the fabric deformation or "bulge". Ballistic tests against Zylon^TM fabric have been performed to measure h and R as a function of time. The results of these experiments are presented and analyzed in the context of the Walker model. Walker (1999), Proceedings of the 18th International Symposium on Ballistics, pp. 1231.

  17. Analogy of meteorite impacts in laboratory conditions

    Energy Technology Data Exchange (ETDEWEB)

    Desai, Tara; Bussoli, Marco; Dezulian, R [Dipartimento di Fisica ' G. Occhialini' , Universita degli studi Milano-Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); Villa, A [Dipartimento di Biotecnologie e Bioscienze, Universita degli studi Milano-Bicocca, Piazza della Scienza, 20126 Milano (Italy); Krousky, E [PALS, Prague (Czech Republic); Aliverdiev, A A [Institute of Physics DSC of Russian Academy of Sciences, 377003, Yaragskogo Street, 94, Makhachkala (Russian Federation); Kubkowska, M; Wolowski, J, E-mail: dtar@hotmail.com [Institute of Plasma Physics and Laser Microfusion, Hery 23 STR 01-497, Warsaw (Poland)

    2010-12-15

    In this work, we report on the possibility of using laser-generated craters to investigate planetary events such as meteorite impact craters. Experiments using a 0.44 {mu}m/350 ps wavelength laser beam on aluminum foil targets are performed. We obtain simple and complex craters similar in contour to those formed due to meteorite impacts on the terrestrial surface. Our preliminary results show that the central peak of complex craters seems to be higher because of the turbulence beneath the crater floor. Results obtained using a two-dimensional radiation hydrodynamic code, MULTI, show that the laser ablation surface modifies and rises. This could be one of several factors explaining the central peak existence.

  18. Nuclear policy impacts at the national laboratories: maintaining the deterrence

    Energy Technology Data Exchange (ETDEWEB)

    Beck, James Bradley [Los Alamos National Laboratory

    2010-08-24

    In this presentation, the author will discuss recent nuclear policy impacts, including the 2010 Nuclear Posture Review, and the impacts they have on maintaining the nuclear deterrent. Specifically, he will highlight some of the remaining questions and challenges that remain to the nation and to the national laboratories. (auth)

  19. Analysis of Multiple-Impact Ballistic Performance of a Tempered Glass Laminate with a Strike Face Film

    Science.gov (United States)

    2014-02-01

    strengthened glass as exterior or strike faces. Initial impact by a single projectile typically produces a quasi-symmetrical crater exhibiting the typical...during subsequent impacts. Should an impact from a second projectile occur on the damaged glass , loosely constrained fragments would be forced in a...Should an impact from a second projectile occur on the damaged glass , loosely constrained fragments would be forced in a direction away from the strike

  20. Ballistic Fracturing of Carbon Nanotubes.

    Science.gov (United States)

    Ozden, Sehmus; Machado, Leonardo D; Tiwary, ChandraSekhar; Autreto, Pedro A S; Vajtai, Robert; Barrera, Enrique V; Galvao, Douglas S; Ajayan, Pulickel M

    2016-09-21

    Advanced materials with multifunctional capabilities and high resistance to hypervelocity impact are of great interest to the designers of aerospace structures. Carbon nanotubes (CNTs) with their lightweight and high strength properties are alternative to metals and/or metallic alloys conventionally used in aerospace applications. Here we report a detailed study on the ballistic fracturing of CNTs for different velocity ranges. Our results show that the highly energetic impacts cause bond breakage and carbon atom rehybridizations, and sometimes extensive structural reconstructions were also observed. Experimental observations show the formation of nanoribbons, nanodiamonds, and covalently interconnected nanostructures, depending on impact conditions. Fully atomistic reactive molecular dynamics simulations were also carried out in order to gain further insights into the mechanism behind the transformation of CNTs. The simulations show that the velocity and relative orientation of the multiple colliding nanotubes are critical to determine the impact outcome.

  1. Effect of Clamping Rigidity of the Armour on Ballistic Performance

    Directory of Open Access Journals (Sweden)

    S. N. Dikshit

    1992-04-01

    Full Text Available Influence of the manner in which the armour plates are held during their ballistic testing on the armour performance, has been evaluated. One armour plate was clamped rigidly to the test stand while a second plate of identical composition, hardness, and dimensions was hung loosely from the target holder. Both these plates were impacted with the same type of projectiles and over the same impact velocity range. The nature of ballistic damage evaluated indicates that the manner in which the armour is held during ballistic testing has a negligible influence on its performance at least when the mass of the plate is substantially higher than that of the projectile.

  2. Evaluation of a laboratory model of human head impact biomechanics.

    Science.gov (United States)

    Hernandez, Fidel; Shull, Peter B; Camarillo, David B

    2015-09-18

    This work describes methodology for evaluating laboratory models of head impact biomechanics. Using this methodology, we investigated: how closely does twin-wire drop testing model head rotation in American football impacts? Head rotation is believed to cause mild traumatic brain injury (mTBI) but helmet safety standards only model head translations believed to cause severe TBI. It is unknown whether laboratory head impact models in safety standards, like twin-wire drop testing, reproduce six degree-of-freedom (6DOF) head impact biomechanics that may cause mTBI. We compared 6DOF measurements of 421 American football head impacts to twin-wire drop tests at impact sites and velocities weighted to represent typical field exposure. The highest rotational velocities produced by drop testing were the 74th percentile of non-injury field impacts. For a given translational acceleration level, drop testing underestimated field rotational acceleration by 46% and rotational velocity by 72%. Primary rotational acceleration frequencies were much larger in drop tests (~100 Hz) than field impacts (~10 Hz). Drop testing was physically unable to produce acceleration directions common in field impacts. Initial conditions of a single field impact were highly resolved in stereo high-speed video and reconstructed in a drop test. Reconstruction results reflected aggregate trends of lower amplitude rotational velocity and higher frequency rotational acceleration in drop testing, apparently due to twin-wire constraints and the absence of a neck. These results suggest twin-wire drop testing is limited in modeling head rotation during impact, and motivate continued evaluation of head impact models to ensure helmets are tested under conditions that may cause mTBI. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Impact Crater Experiments for Introductory Physics and Astronomy Laboratories

    Science.gov (United States)

    Claycomb, J. R.

    2009-01-01

    Activity-based collisional analysis is developed for introductory physics and astronomy laboratory experiments. Crushable floral foam is used to investigate the physics of projectiles undergoing completely inelastic collisions with a low-density solid forming impact craters. Simple drop experiments enable determination of the average acceleration,…

  4. Transport Energy Impact Analysis; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Gonder, J.

    2015-05-13

    Presented at the Sustainable Transportation Energy Pathways Spring 2015 Symposium on May 13, 2015, this presentation by Jeff Gonder of the National Renewable Energy Laboratory (NREL) provides information about NREL's transportation energy impact analysis of connected and automated vehicles.

  5. Ballistic hole magnetic microscopy

    NARCIS (Netherlands)

    Haq, E.; Banerjee, T.; Siekman, M.H.; Lodder, J.C.; Jansen, R.

    2005-01-01

    A technique to study nanoscale spin transport of holes is presented: ballistic hole magnetic microscopy. The tip of a scanning tunneling microscope is used to inject hot electrons into a ferromagnetic heterostructure, where inelastic decay creates a distribution of electron-hole pairs. Spin-dependen

  6. Ballistic hole magnetic microscopy

    NARCIS (Netherlands)

    Haq, E.; Banerjee, T.; Siekman, M.H.; Lodder, J.C.; Jansen, R.

    2005-01-01

    A technique to study nanoscale spin transport of holes is presented: ballistic hole magnetic microscopy. The tip of a scanning tunneling microscope is used to inject hot electrons into a ferromagnetic heterostructure, where inelastic decay creates a distribution of electron-hole pairs.

  7. Impact on human resources: Core Laboratory versus laboratory information system versus modular robotics.

    Science.gov (United States)

    Dadoun, R

    1998-01-01

    Technological advances in laboratory systems have had a great impact on human resources. Surviving the changes requires an in-depth understanding of the technology to implement the appropriate operational model. St. Mary's is a 414-bed, acute care hospital. For 18 months, the laboratories went through the process of moving from a noncomputerized traditional model laboratory (i.e., by discipline) to a fully computerized Core Lab. The Core Lab concept fully integrates biochemistry, hematology, blood bank, and microbiology into two sections (not physically separated): tests processed by automation and tests processed manually. This approach led to a 15% reduction in staff while the volume doubled. The transitions occurred sequentially: from traditional laboratory to Core Lab (noncomputerized), from manual Core Lab to fully computerized Core Lab, and ultimately from a simulation of manual preanalytical phase to automated preanalytical phase (modular robotics). The findings show that Core Lab and computerization have almost the same impact on human resources, 35% and 30% respectively, and modular robotics the least impact with 17%.

  8. Hybrid Carbon-Glass Fiber/Toughened Epoxy Thick Composite Joints Subject to Drop-Weight and Ballistic Impacts

    Science.gov (United States)

    2007-12-01

    Composite Materials 1988; 22: 518-532. 111. Liaw BM, Pierides AM and Liu YX. Ultrasonic assessment of impact damage in aluminum /acrylic sandwich plates...Ninth International Conference on Composite Materials , ICCM/9, Vol. V: Composites Behaviour , Miravete A (Ed), Madrid, Spain, July 12-16, 1993: 311-320...line loading. J. of Composite Materials 1993; 27: 1443-64. 148. Mouritz AP, Gallagher J and Goodwin AA. Flexural strength and interlaminar shear

  9. Missile Defense Agency Ballistic Missile Defense System (BMDS): Programmatic Environmental Impact Statement. Volume 1 Final BMDS PEIS

    Science.gov (United States)

    2007-01-01

    dwarfed shrubs and miniature wildflowers adapted to a short growing season. Species resident in arctic tundra have evolved adaptations peculiar to high...strong northeast winds, the likelihood of pollutants remaining in the ambient air is low. Heavy industrial activities, high automobile traffic, and...bodies. Some perennial surface waters could be impacted following a flight termination. However, the probability of any individual water body, spring

  10. The application of a calibrated 3D ballistic trajectory model to ballistic hazard assessments at Upper Te Maari, Tongariro

    Science.gov (United States)

    Fitzgerald, R. H.; Tsunematsu, K.; Kennedy, B. M.; Breard, E. C. P.; Lube, G.; Wilson, T. M.; Jolly, A. D.; Pawson, J.; Rosenberg, M. D.; Cronin, S. J.

    2014-10-01

    On 6 August, 2012, Upper Te Maari Crater, Tongariro volcano, New Zealand, erupted for the first time in over one hundred years. Multiple vents were activated during the hydrothermal eruption, ejecting blocks up to 2.3 km and impacting ~ 2.6 km of the Tongariro Alpine Crossing (TAC) hiking track. Ballistic impact craters were mapped to calibrate a 3D ballistic trajectory model for the eruption. This was further used to inform future ballistic hazard. Orthophoto mapping revealed 3587 impact craters with a mean diameter of 2.4 m. However, field mapping of accessible regions indicated an average of at least four times more observable impact craters and a smaller mean crater diameter of 1.2 m. By combining the orthophoto and ground-truthed impact frequency and size distribution data, we estimate that approximately 13,200 ballistic projectiles were generated during the eruption. The 3D ballistic trajectory model and a series of inverse models were used to constrain the eruption directions, angles and velocities. When combined with eruption observations and geophysical observations, the model indicates that the blocks were ejected in five variously directed eruption pulses, in total lasting 19 s. The model successfully reproduced the mapped impact distribution using a mean initial particle velocity of 200 m/s with an accompanying average gas flow velocity over a 400 m radius of 150 m/s. We apply the calibrated model to assess ballistic hazard from the August eruption along the TAC. By taking the field mapped spatial density of impacts and an assumption that an average ballistic impact will cause serious injury or death (casualty) over an 8 m2 area, we estimate that the probability of casualty ranges from 1% to 16% along the affected track (assuming an eruption during the time of exposure). Future ballistic hazard and probabilities of casualty along the TAC are also assessed through application of the calibrated model. We model a magnitude larger eruption and illustrate

  11. Hypervelocity Impact Experiments in the Laboratory Relating to Lunar Astrobiology

    Science.gov (United States)

    Burchell, M. J.; Parnell, J.; Bowden, S. A.; Crawford, I. A.

    2010-12-01

    The results of a set of laboratory impact experiments (speeds in the range 1-5 km s-1) are reviewed. They are discussed in the context of terrestrial impact ejecta impacting the Moon and hence lunar astrobiology through using the Moon to learn about the history of life on Earth. A review of recent results indicates that survival of quite complex organic molecules can be expected in terrestrial meteorites impacting the lunar surface, but they may have undergone selective thermal processing both during ejection from the Earth and during lunar impact. Depending on the conditions of the lunar impact (speed, angle of impact etc.) the shock pressures generated can cause significant but not complete sterilisation of any microbial load on a meteorite (e.g. at a few GPa 1-0.1% of the microbial load can survive, but at 20 GPa this falls to typically 0.01-0.001%). For more sophisticated biological products such as seeds (trapped in rocks) the lunar impact speeds generate shock pressures that disrupt the seeds (experiments show this occurs at approximately 1 GPa or semi-equivalently 1 km s-1). Overall, the delivery of terrestrial material of astrobiological interest to the Moon is supported by these experiments, although its long term survival on the Moon is a separate issue not discussed here.

  12. Determining the Equation of State (EoS) Parameters for Ballistic Gelatin

    Science.gov (United States)

    2015-09-01

    ARL-TR-7467 ● SEP 2015 US Army Research Laboratory Determining the Equation of State (EoS) Parameters for Ballistic Gelatin ...EoS) Parameters for Ballistic Gelatin by Yolin Huang Weapons and Materials Research Directorate, ARL Approved for...State (EoS) Parameters for Ballistic Gelatin 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Yolin Huang 5d

  13. Impact of the implementation of a well-designed electronic laboratory notebook on bioanalytical laboratory function.

    Science.gov (United States)

    Zeng, Jianing; Hillman, Mark; Arnold, Mark

    2011-07-01

    This paper shares experiences of the Bristol-Myers Squibb Company during the design, validation and implementation of an electronic laboratory notebook (ELN) into the GLP/regulated bioanalytical analysis area, as well as addresses the impact on bioanalytical laboratory functions with the implementation of the electronic notebook. Some of the key points covered are: knowledge management - the project-based electronic notebook takes full advantage of the available technology that focuses on data organization and sharing so that scientific data generated by individual scientists became department knowledge; bioanalytical workflows in the ELN - the custom-built workflows that include data entry templates, validated calculation processes, integration with laboratory information management systems/laboratory instruments, and reporting capability improve the data quality and overall workflow efficiency; regulatory compliance - carefully designed notebook reviewing processes, cross referencing of distributed information, audit trail and software validation reduce compliance risks. By taking into consideration both data generation and project documentation needs, a well-designed ELN can deliver significant improvements in laboratory efficiency, work productivity, and regulatory compliance.

  14. A Residual Mass Ballistic Testing Method to Compare Armor Materials or Components (Residual Mass Ballistic Testing Method)

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin Langhorst; Thomas M Lillo; Henry S Chu

    2014-05-01

    A statistics based ballistic test method is presented for use when comparing multiple groups of test articles of unknown relative ballistic perforation resistance. The method is intended to be more efficient than many traditional methods for research and development testing. To establish the validity of the method, it is employed in this study to compare test groups of known relative ballistic performance. Multiple groups of test articles were perforated using consistent projectiles and impact conditions. Test groups were made of rolled homogeneous armor (RHA) plates and differed in thickness. After perforation, each residual projectile was captured behind the target and its mass was measured. The residual masses measured for each test group were analyzed to provide ballistic performance rankings with associated confidence levels. When compared to traditional V50 methods, the residual mass (RM) method was found to require fewer test events and be more tolerant of variations in impact conditions.

  15. Ballistic negatron battery

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M.S.R. [Koneru Lakshmiah Univ.. Dept. of Electrical and Electronics Engineering, Green fields, Vaddeswaram (India)

    2012-07-01

    If we consider the Statistics there is drastic increase in dependence of batteries from year to year, due to necessity of power storage equipment at homes, power generating off grid and on grid Wind, PV systems, etc.. Where wind power is leading in renewable sector, there is a need to look at its development. Considering the scenario in India, most of the wind resource areas are far away from grid and the remaining areas which are near to grid are of low wind currents which is of no use connecting these equipment directly to grid. So, there is a need for a power storage utility to be integrated, such as the BNB (Ballistic Negatron Battery). In this situation a country like India need a battery which should be reliable, cheap and which can be industrialized. So this paper presents the concept of working, design, operation, adaptability of a Ballistic Negatron Battery. Unlike present batteries with low energy density, huge size, more weight, more charging time and low resistant to wear level, this Ballistic Negatron Battery comes with, 1) High energy storage capability (many multiples more than the present most advanced battery). 2) Very compact in size. 3) Almost negligible in weight compared to present batteries. 4) Charges with in very less time. 5) Never exhibits a wear level greater than zero. Seems like inconceivable but adoptable with simple physics. This paper will explains in detail the principle, model, design, construction and practical considerations considered in making this battery. (Author)

  16. Ballistic transport and electronic structure

    NARCIS (Netherlands)

    Schep, Kees M.; Kelly, Paul J.; Bauer, Gerrit E.W.

    1998-01-01

    The role of the electronic structure in determining the transport properties of ballistic point contacts is studied. The conductance in the ballistic regime is related to simple geometrical projections of the Fermi surface. The essential physics is first clarified for simple models. For real

  17. The increasing impact of laboratory medicine on clinical cardiology.

    Science.gov (United States)

    Clerico, Aldo

    2003-07-01

    The practice of cardiology continues to evolve along with a better understanding of the pathophysiology of cardiovascular disease and the development of new therapeutic procedures. Consequently, new demands are being made on the in vitro diagnostics industry to improve the performance of existing cardiac markers and to develop novel markers for new cardiac disease indications. Indeed, in the last 20 years there has been a progressive increase in new laboratory tests for markers of cardiac diseases. Several highly sensitive and/or specific assays for the detection of myocardial ischemic damage as well as some immunoassays for cardiac natriuretic hormones, now considered a reliable marker of myocardial function, have become commercially available. In parallel, a growing number of some novel risk factors, which can be assessed and monitored by laboratory methods, have been added to the classical risk factors for cardiovascular disease. Finally, the recent explosion of genetic analysis may soon place at the clinical cardiologist's disposal many laboratory tests for defining the diagnosis at the molecular level, assessing new risk factors, and better targeting the pharmaceutical approaches in patients with cardiovascular disease. In the present article, after a brief description of the analytical tests included in these four groups, each group's impact on clinical cardiology is discussed in detail.

  18. Laboratory investigation of antenna signals from dust impacts on spacecraft

    Science.gov (United States)

    Sternovsky, Zoltan; Collette, Andrew; Malaspina, David M.; Thayer, Frederick

    2016-04-01

    Electric field and plasma wave instruments act as dust detectors picking up voltage pulses induced by impacts of particulates on the spacecraft body. These signals enable the characterization of cosmic dust environments even with missions without dedicated dust instruments. For example, the Voyager 1 and 2 spacecraft performed the first detection of dust particles near Uranus, Neptune, and in the outer solar system [Gurnett et al., 1987, 1991, 1997]. The two STEREO spacecraft observed distinct signals at high rate that were interpreted as nano-sized particles originating from near the Sun and accelerated to high velocities by the solar wind [MeyerVernet et al, 2009a, Zaslavsky et al., 2012]. The MAVEN spacecraft is using the antennas onboard to characterize the dust environment of Mars [Andersson et al., 2014] and Solar Probe Plus will do the same in the inner heliosphere. The challenge, however, is the correct interpretation of the impact signals and calculating the mass of the dust particles. The uncertainties result from the incomplete understanding of the signal pickup mechanisms, and the variation of the signal amplitude with impact location, the ambient plasma environment, and impact speed. A comprehensive laboratory study of impact generated antenna signals has been performed recently using the IMPACT dust accelerator facility operated at the University of Colorado. Dust particles of micron and submicron sizes with velocities of tens of km/s are generated using a 3 MV electrostatic analyzer. A scaled down model spacecraft is exposed to the dust impacts and one or more antennas, connected to sensitive electronics, are used to detect the impact signals. The measurements showed that there are three clearly distinct signal pickup mechanisms due to spacecraft charging, antenna charging and antenna pickup sensing space charge from the expanding plasma cloud. All mechanisms vary with the spacecraft and antenna bias voltages and, furthermore, the latter two

  19. Q235钢板对平头弹抗侵彻特性研究%Ballistic performance of Q235 metal plates subjected to impact by blunt-nosed projectiles

    Institute of Scientific and Technical Information of China (English)

    邓云飞; 张伟; 孟凡柱

    2015-01-01

    In order to investigate the influence of configuration of target on the ballistic performance, monolithic and three⁃layered targets were normally impacted by blunt⁃nosed projectiles in the velocity range of 190~450 m/s with the help of a gas gun, and also the photos of the impact process were obtained. Based on the tests, the residual velocity versus the initial velocity curves of the projectiles were constructed, and also ballistic limit velocities were obtained. The influence of combination configuration of target on the ballistic characteristic, including the ballistic resistance and failure models were investigated. Moreover, the penetration process of metal plates impacted by rod projectiles had been studied with numerical simulation code ABAQUS/EXPLICIT, and also the validation of models and parameters of materials had been proved by comparing the experiment results with numerical simulations. The results indicated that the ballistic limit velocity of multi⁃layered target was higher than that of monolithic target, and also there were differences between failure models of multi⁃layered targets and monolithic target. Moreover, the failure models of plates of multi⁃layered targets were in relation to their order.%为分析靶体结构对其抗侵彻特性的影响,利用轻气炮进行平头杆弹正撞击单层板和等厚接触式三层板的实验,获取相关的撞击过程图片.通过撞击实验,得到这两种结构靶体的初始-剩余速度曲线以及弹道极限,撞击速度为190~450 m/s.研究靶体结构对抗侵彻特性的影响,包括靶板的失效模式和抗侵彻性能.最后,采用ABAQUS/EXPLICIT软件对杆弹撞击金属板的过程进行数值模拟研究,通过对比数值模拟和实验结果,验证了数值模拟材料模型和参数的有效性.结果表明:多层板的弹道极限高于等厚单层板,并且多层板和单层板的主要失效模式之间存在差异.对于多层板

  20. A Numerical Investigation of the influence of Yarn-Level Finite-Element Model on Energy Absorption by a Flexible Fabric Armour During Ballistic Impact

    Science.gov (United States)

    2008-01-01

    clamping pressure on the ballistic performance of soft body armor. Compos. B, in press. 13 Kawabata , S., Niwa, M., and Kawai, H. The finite...deformation theory of plain-weave fabrics part I: the biaxial-deformation theory. J. Text. Inst., 1973, 64, 21–46. 14 Kawabata , S., Niwa, M., and Kawai, H...The finite- deformation theory of plain-weave fabrics. Part II. The uniaxial-deformation theory. J. Text. Inst., 1973, 64, 47–61. 15 Kawabata , S., Niwa

  1. FE analysis of the effect of friction on ballistic impact performance of woven fabrics%摩擦力对织物防弹性能影响的有限元分析

    Institute of Scientific and Technical Information of China (English)

    王莹; 陈晓刚

    2013-01-01

    纱线之间的摩擦力对织物的防弹性能有很大影响,但是始终缺少对失效机制了解。例如,多大的摩擦力有利于织物吸收能量,纱线间的摩擦力对应力分布的影响等。本文采用有限元分析的方法对摩擦力影响的机理进行了系统的研究,采用ABAQUS建立织物的有限元分析模型。研究表明,织物的防弹性能随纱线之间摩擦力的增大而增加。应力在纱线上的分布随摩擦力的变化而改变。增大摩擦力能减少接触区边缘的应力。因此,摩擦力较大的织物需要更多的时间才能被穿透,这将有助于吸收更多的能量。研究还表明摩擦力的增加会导致纵向波速下降,能量吸收会因此而减少。但是,增加摩擦力会产生较大的横向波,能量吸收会因此而增加。%Many attempts have been done to investigate the effect of friction on ballistic impact response of woven fabrics .It has been shown that friction plays an important role in determi-ning the ballistic impact performance of fabrics .Currently ,there is little fundamental under-standing of impact failure mechanisms in woven fabrics .For example ,what levels of inter-yarn friction are beneficial to energy absorption capacity of the fabrics , how friction affects the stress distributions w hich are crucial important in determining the failure modes of yarns and energy absorption .In this paper ,a detailed study using finite element analysis has been carried out .The purpose of the paper is to study numerically the way in which friction affects the im-pact behaviour of ballistic fabrics and to determine the distribution and magnitude of the stres-ses .The finite element model was created using ABAQUS to simulate the transverse impact onto woven fabrics . The calculated results show that the ballistic impact performance of woven fabrics increa-ses with increasing levels of friction .The stress distributions on the yarns are sensitive to the

  2. Laboratory investigations of the survivability of bacteria in hypervelocity impacts.

    Science.gov (United States)

    Burchell, M J; Shrine, N R; Mann, J; Bunch, A W; Brandao, P; Zarnecki, J C; Galloway, J A

    2001-01-01

    It is now well established that material naturally moves around the Solar System, even from planetary surface to planetary surface. Accordingly, the idea that life is distributed throughout space and did not necessarily originate on the Earth but migrated here from elsewhere (Panspermia) is increasingly deemed worthy of consideration. If life arrived at the Earth from space, its relative speed will typically be of order many km s-1, and the resulting collision with the Earth and its atmosphere will be in the hypervelocity regime. A mechanism for the bacteria to survive such an impact is required. Therefore a programme of hypervelocity impacts in the laboratory at (4.5 +/- 0.6) km s-1 was carried out using bacteria (Rhodococcus) laden projectiles. After impacts on a variety of target materials (rock, glass and metal) attempts were made to culture Rhodococcus from the surface of the resulting craters and also from the target material ejected during crater formation. Control shots with clean projectiles yielded no evidence for Rhodococcus growth from any crater surface or ejecta. When projectiles doped with Rhodococcus were used no impact crater surface yielded colonies of Rhodococcus. However, for four shots of bacteria into rock (two on chalk and two on granite) the ejecta was afterwards found to give colonies of Rhodococcus. This was not true for shots onto glass. In addition, shots into aerogel (density 96 kg m-3) were also carried out (two with clean projectiles and two with projectiles with Rhodococcus). This crudely simulated aero-capture in a planetary atmosphere. No evidence for Rhodococcus growth was found from the projectiles captured in the aerogel from any of the four shots.

  3. Research on ballistic missile laser SIMU error propagation mechanism

    Institute of Scientific and Technical Information of China (English)

    Wei Shihui; Xiao Longxu

    2008-01-01

    It is necessary that the laser inertial system is used to further improve the fire accuracy and quick reaction capability in the ballistic missile strapdown inertial navigation system. According to the guidance con-trolling method and the output and error model of ballistic missile laser SIMU, the mathematical model of error propagation mechanism is set up and any transfer environmental function of error coefficient that affects the fire accuracy is deduced. Also, the missile longitudinal/lateral impact point is calculated using MATLAB. These estab-lish the technical foundation for further researching the dispersion characteristics of impact point and reducing the laser guidance error.

  4. Ballistic Missile Defense System (BMDS)

    Science.gov (United States)

    2015-12-01

    Estimate RDT&E - Research , Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be Determined TY - Then...all ranges and in all phases of flight. Following guidance from the President, the Secretary of Defense approved the Ballistic Missile Defense (BMD...based Midcourse Defense (GMD) system to enhance our capability against Intercontinental Ballistic Missiles. We are currently sustaining 30

  5. The Dynamic Behaviour of Ballistic Gelatin

    Science.gov (United States)

    Shepherd, C. J.; Appleby-Thomas, G. J.; Hazell, P. J.; Allsop, D. F.

    2009-12-01

    In order to characterise the effect of projectiles it is necessary to understand the mechanism of both penetration and resultant wounding in biological systems. Porcine gelatin is commonly used as a tissue simulant in ballistic tests because it elastically deforms in a similar manner to muscular tissue. Bullet impacts typically occur in the 350-850 m/s range; thus knowledge of the high strain-rate dynamic properties of both the projectile and target materials are desirable to simulate wounds. Unlike projectile materials, relatively little data exists on the dynamic response of flesh simulants. The Hugoniot for a 20 wt.% porcine gelatin, which exhibits a ballistic response similar to that of human tissues at room temperature, was determined using the plate-impact technique at impact velocities of 75-860 m/s. This resulted in impact stresses around three times higher than investigated elsewhere. In US-uP space the Hugoniot had the form US = 1.57+1.77 uP, while in P-uP space it was essentially hydrodynamic. In both cases this was in good agreement with the limited available data from the literature.

  6. Experimental investigation on ballistic stability of high-speed projectile in sand

    Science.gov (United States)

    Zhang, Wei; Huang, Xianglin; Qi, Yafei; Li, Dacheng; Tao, Jialiang; Huang, Wei

    2017-01-01

    The investigation on ballistic stability of high-speed projectile in granular materials is important to study the EPW (earth-penetrating weapon). Laboratory-scaled sand entry experiments for the trajectory in the sand have been performed at a range of velocities from 30 m/s to 150 m/s. In addition, pressure sensor was embedded in the sand to record the sand stress which reflects the penetration performance of projectile during the impact. The slender projectiles were designed into flat nose shape with three kinds of L/D (length-diameter ratio) to make comparisons on the trajectory when those projectiles were launched at normal and oblique impact angles (0˜25deg) along a view window. A high-speed camera beside window was employed to capture the entire process of projectiles' penetration. Basing on the comparison of different tests, theoretical analysis is carried out on the relationship between ballistic stability and associated conditions. By utilizing DIC technique, the vector field of sand velocity was acquired, and the spreading direction of the impacting energy was observed. It can be concluded that the sand stress is the function of penetrating velocity, L/D and the shot angle. It increases with the growing of penetrating velocity and L/D, decreases with the shot angle. To a certain extent, the biggest initial velocity leads to the highest stress.

  7. Comparing Terminal Performance of .357 SIG and 9mm Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video

    CERN Document Server

    Keys, Elizabeth; Courtney, Michael

    2015-01-01

    High-speed video has emerged as an valuable tool for quantifying bullet performance in ballistic gelatin. This paper presents the results of testing four .357 SIG bullets using high-speed video of bullet impacts in ballistic gelatin to determine retarding force curves, permanent cavities, temporary cavities, and energy deposit vs. penetration depth. Since the methods are identical, results are meaningfully compared with four 9mm NATO bullets studied in an earlier project. Though .357 SIG bullets perform slightly better due to higher impact energy, the principal finding is that there is a much bigger difference in performance between the best and worst performing bullets in each cartridge than there is between bullets of similar design in the two cartridges. In each cartridge, higher performing expanding bullets (jacketed hollow points) outperform non-expanding bullets (full metal jacket) by a wide margin, showing a much higher probability of rapid incapacitation according to an Army Research Laboratory model ...

  8. Optimizing Ballistic Imaging Operations.

    Science.gov (United States)

    Wang, Can; Beggs-Cassin, Mardy; Wein, Lawrence M

    2017-04-03

    Ballistic imaging systems can help solve crimes by comparing images of cartridge cases, which are recovered from a crime scene or test-fired from a gun, to a database of images obtained from past crime scenes. Many U.S. municipalities lack the resources to process all of their cartridge cases. Using data from Stockton, CA, we analyze two problems: how to allocate limited capacity to maximize the number of cartridge cases that generate at least one hit, and how to prioritize the cartridge cases that are processed to maximize the usefulness (i.e., obtained before the corresponding criminal case is closed) of hits. The number of hits can be significantly increased by prioritizing crime scene evidence over test-fires, and by ranking calibers by their hit probability and processing only the higher ranking calibers. We also estimate that last-come first-served increases the proportion of hits that are useful by only 0.05 relative to first-come first-served.

  9. The Second National Ballistics Imaging Comparison (NBIC-2)

    Science.gov (United States)

    Vorburger, TV; Yen, J; Song, JF; Thompson, RM; Renegar, TB; Zheng, A; Tong, M; Ols, M

    2014-01-01

    In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, NIST and the ATF initiated a joint project, entitled the National Ballistics Imaging Comparison (NBIC). The NBIC project aims to establish a national traceability and quality system for ballistics identifications in crime laboratories utilizing ATF’s National Integrated Ballistics Information Network (NIBIN). The original NBIC was completed in 2010. In the second NBIC, NIST Standard Reference Material (SRM) 2461 Cartridge Cases were used as reference standards, and 14 experts from 11 U.S. crime laboratories each performed 17 image acquisitions and correlations of the SRM cartridge cases over the course of about half a year. Resulting correlation scores were collected by NIST for statistical analyses, from which control charts and control limits were developed for the proposed quality system and for promoting future assessments and accreditations for firearm evidence in U.S. forensic laboratories in accordance with the ISO 17025 Standard. PMID:26601051

  10. Effect of tempering time on the ballistic performance of a high strength armour steel

    Directory of Open Access Journals (Sweden)

    Pradipta Kumar Jena

    2016-02-01

    Full Text Available The investigation describes and analyses the effect of tempering time on the mechanical and ballistic performance of a high strength armour steel. The steel is subjected to tempering at 300 °C for 2, 24 and 48 h. A marginal variation in strength and hardness is observed with increase in tempering time, whereas ductility and Charpy impact values are found to be decreasing. Ballistic performance of the samples are evaluated by impacting 7.62 mm and 12.7 mm armour piercing projectiles at 0° angle of impact. Results show a small variation in the ballistic performance when impacted with 7.62 mm armour piercing projectile. A decrease in ballistic performance of the material is observed with increasing tempering time when impacted with 12.7 mm armour piercing ammunition.

  11. Gunshot wounds: A review of ballistics related to penetrating trauma

    Directory of Open Access Journals (Sweden)

    Panagiotis K. Stefanopoulos

    2014-01-01

    Full Text Available Civilian gunshot injuries from handgun and rifle ammunition vary in severity depending on the anatomic location involved and the different effects from the ballistic properties of the penetrating projectiles. Ballistic factors such as the impact velocity and energy should not be considered in isolation, as their specific effects are determined by the interaction between the projectile and tissues. Increased tissue damage can result from tumbling of non-deforming rifle bullets and deformation of expanding bullets. Both of these mechanisms increase substantially the energy transfer to the wound and its diameter, also producing a pulsating temporary cavity associated with pressure changes within tissue.

  12. Chicxulub High-Altitude Ballistic Ejecta from Central Belize

    Science.gov (United States)

    Pope, K. O.; Ocampo, A. C.

    2000-01-01

    Chicxulub ejecta are found in central Belize, 475 km southeast of the impact crater center. These deposits are ballistic ejecta launched along high-altitude trajectories above the atmosphere and deposited as a discontinuous sheet on the terminal Cretaceous land surface.

  13. An Analytical Model of Ballistic Impact on Light Ceramic/Metal Lightweight Armours%轻型陶瓷/金属复合装甲抗弹分析模型研究

    Institute of Scientific and Technical Information of China (English)

    侯海量; 仲强; 朱锡

    2015-01-01

    To explore the design method of light ceramic composite armor, an approximate analytical model of ballistic impact on ceramic/metal composite armor focused on thin back plate and dishing-shearing-petal failure is proposed, based on response characteristics experimental investigation and analysis of the response characteristics. The model takes the projectile’s erosion failure and ceramic fragments out of bullet surface into account, moving in the direction of lateral and the anti-impacting to get the dynamic impacting response and failure in the ceramic/metal composite armor metal back panel and formula of ballistic limit velocity of the ceramic/metal composite armor and calculation. Model analysis results are in good agreement with those obtained with the test results.%为探讨轻型陶瓷复合装甲结构设计,在弹道冲击响应特性试验研究与分析的基础上,针对薄金属背板支撑的陶瓷复合装甲,以金属背板发生碟型变形—剪切—花瓣型失效为分析对象,建立了陶瓷/金属复合装甲侵彻过程的近似解析模型。模型考虑了弹体的侵蚀失效及陶瓷碎片脱离弹头表面,向侧向和反冲击方向的运动,得到了陶瓷/金属复合装甲中金属背板的动态冲击响应及失效,陶瓷/金属复合装甲的弹道极限速度计算公式和弹体的剩余速度计算方法,模型分析结果与试验结果吻合良好。

  14. Investigation on Analytical Model of Ballistic Impact on Light Ceramic/Metal Lightweight Armours%轻型陶瓷/金属复合装甲抗弹分析模型研究

    Institute of Scientific and Technical Information of China (English)

    侯海量; 仲强; 朱锡

    2015-01-01

    To explore the design method of light ceramic composite armor, an approximate analytical model of ballistic impact on ceramic/metal composite armor focused on thin back plate and dishing-shearing-petal failure was proposed, based on response characteristics experimental investigation and analysis of the response characteristics. The model takes into account projectile’s erosion failure and ceramic fragments out of bullet surface, moving in the direction of lateral and the anti-impacting to get the dynamic impacting response and failure in the ceramic/metal composite armor metal back panel and formula of ballistic limit velocity of the ceramic/metal composite armor and calculation. Model analysis results are in good agreement with those obtained with the test results.%为探讨轻型陶瓷复合装甲结构设计,在弹道冲击响应特性试验研究与分析的基础上,针对薄金属背板支撑的陶瓷复合装甲,以金属背板发生碟型变形-剪切-花瓣型失效为分析对象,建立了陶瓷/金属复合装甲侵彻过程的近似解析模型。模型考虑了弹体的侵蚀失效及陶瓷碎片脱离弹头表面,向侧向和反冲击方向的运动,得到了陶瓷/金属复合装甲中金属背板的动态冲击响应及失效,陶瓷/金属复合装甲的弹道极限速度计算公式和弹体的剩余速度计算方法,模型分析结果与试验结果吻合良好。

  15. Modeling Of Ballistic Missile Dynamics

    Directory of Open Access Journals (Sweden)

    Salih Mahmoud Attiya

    2013-05-01

    Full Text Available Aerodynamic modeling of ballistic missile in pitch plane is performed and the open-loop transfer function related to the jet deflector angle as input and pitch rate, normal acceleration as output has been derived with certain acceptable assumptions. For typical values of ballistic missile parameters such as mass, velocity, altitude, moment of inertia, thrust, moment and lift coefficient show that, the step time response and frequency response of the missile is unstable. The steady state gain, damping ratio and undraped natural frequency depend on the missile parameters. To stabilize the missile a lead compensator must be added to the forward loop.

  16. Numerical simulation of ballistic impact on composite armours%复合装甲抗侵彻性能的数值分析

    Institute of Scientific and Technical Information of China (English)

    过超强; 赵桂平

    2013-01-01

    用数值分析的方法分别对金属、陶瓷、纤维增强复合材料组成的层合板和由陶瓷球填充的金属四边形蜂窝夹芯结构在冲击载荷作用下的抗侵彻性能进行了模拟计算.其中冲击载荷由12.7mm直径的刚性穿甲弹模拟.研究了不同构型靶板在侵彻过程中对动能量的吸收机理,分析了两种复合靶板各组分材料的吸能特性,并比较了不同靶板的弹道极限速度V50.研究结果表明:在相同面密度条件下,层合复合靶板中具有最强抗弹性能的陶瓷层与纤维层的最佳比例是2.22,其与4340钢均质靶板相比质量减轻了33%;蜂窝填充陶瓷结构的靶板中灌注环氧树脂后其弹道极限速度提高了13%.%Finite element analysis using LS-DYNA has been performed to investigate the penetration-resistance properties of composite armours.A 3-D model consisting of the various discrete layers of the armour has been built and subjected to transient dynamic loading.The projectile is a bullet with 12.7mm diameter.The dynamic responses of the integral armour having two different types of core topology: multi-component layers of 4340 steel,B4C ceramic and FRP core and square honeycomb filled with ceramic ball and epoxy core are simulated and analyzed.Numerical modeling is used to obtain an estimate for the ballistic limit velocity (V50) and simulate penetration processes.The focus is placed on the energy absorption capabilities of different component layers with same density per unit area.Results of the study indicate that the composite armour having thickness ratio of 2.22 between ceramic and FRP layers is an excellent one with highest ballistic limit velocity in all laminated composite armours and its mass is 33% lighter than that of 4340 steel target.Furthermore,it is found that the V50 of composite armour with square honeycomb filled with ceramic ball and epoxy cores is 13% higher than that without epoxy filled.

  17. Design of a Combined Ballistic Simulator and Primer Force Experimental Fixture

    Science.gov (United States)

    2015-08-01

    ARL-MR-0896 ●AUG 2015 US Army Research Laboratory Design of a Combined Ballistic Simulator and Primer Force Experimental Fixture...SUBTITLE Design of a Combined Ballistic Simulator and Primer Force Experimental Fixture 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...Contents List of Figures iv Acknowledgments v 1. Introduction 1 2. Background 1 3. Technical Approach 4 3.1 Hardware Design 4 3.2 Experimental Setup

  18. BALLISTIC RESISTANT ARTICLES COMPRISING TAPES

    NARCIS (Netherlands)

    VAN DER EEM, JORIS; HARINGS, JULES; JANSE, GERARDUS; TJADEN, HENDRIK

    2015-01-01

    The invention pertains to a ballistic-resistant moulded article comprising a compressed stack of sheets comprising reinforcing tapes having a tensile strength of at least 1.0 GPa, a tensile modulus of at least 40 GPa, and a tensile energy-to-break of at least 15 J/g, the direction of the tapes withi

  19. Ballistics examination of air rifle.

    Science.gov (United States)

    Bogiel, G

    2014-01-01

    The aim of this paper is to determine the velocity, energy, maximum range and distance at which pellets fired from an air rifle of kinetic energy below 17 J can pose a threat to unprotected human skin. Doppler radar equipment and exterior ballistics software were used in this examination.

  20. Ballistics examination of air rifle

    Directory of Open Access Journals (Sweden)

    Grzegorz Bogiel

    2014-08-01

    Full Text Available The aim of this paper is to determine the velocity, energy, maximum range and distance at which pellets fired from an air rifle of kinetic energy below 17 J can pose a threat to unprotected human skin. Doppler radar equipment and exterior ballistics software were used in this examination.

  1. Ballistics examination of air rifle

    OpenAIRE

    2014-01-01

    The aim of this paper is to determine the velocity, energy, maximum range and distance at which pellets fired from an air rifle of kinetic energy below 17 J can pose a threat to unprotected human skin. Doppler radar equipment and exterior ballistics software were used in this examination.

  2. BALLISTIC RESISTANT ARTICLES COMPRISING TAPES

    NARCIS (Netherlands)

    VAN DER EEM, JORIS; HARINGS, JULES; JANSE, GERARDUS; TJADEN, HENDRIK

    2015-01-01

    The invention pertains to a ballistic-resistant moulded article comprising a compressed stack of sheets comprising reinforcing tapes having a tensile strength of at least 1.0 GPa, a tensile modulus of at least 40 GPa, and a tensile energy-to-break of at least 15 J/g, the direction of the tapes

  3. Optimization theory for ballistic conversion

    NARCIS (Netherlands)

    Xie, Yanbo; Versluis, Andreas Michel; van den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    The growing demand of renewable energy stimulates the exploration of new materials and methods for clean energy. We recently demonstrated a high efficiency and power density energy conversion mechanism by using jetted charged microdroplets, termed as ballistic energy conversion. Hereby, we model and

  4. Kevlar-129纤维复合材料的弹道侵彻数值仿真%Ballistic impact simulation of Kevlar-1 29 fiber reinforced composite material

    Institute of Scientific and Technical Information of China (English)

    张明; 原梅妮; 向丰华; 王振兴

    2015-01-01

    The penetration resistance of Kevlar-129 fiber reinforced composite materials was investigated with AUTODYN soft-ware.The ballistic limits of the fragment that pierced 6 kinds of target plates were obtained by finite element simulation when the 10 g fragment simulation projectile (FSP)impacting to the target plates of different thickness values of 8,10,12,14,16 and 1 8 mm with appropriate velocity,respectively,and the influences of thickness on the ballistic limits and the specific energy absorption were analyzed.The results show that the ballistic limit of Kevlar-129 fiber reinforced composite plates presents line-ar growth with the increase of the target thickness in the range from 8 to 1 8 mm.The specific energy absorption of plates pres-ents approximately linear growth,but there is slightly slow growth in the range from 10 to 16 mm of the target thickness.It al-so can be found that the influences of plate thickness and surface density on the varying pattern of specific energy absorption are almost the same.Therefore,both of them can be used to characterize the variation of specific energy absorption under the im-pact of the FSP fragment.%基于 AUTODYN有限元软件,研究了Kevlar-129纤维增强复合材料的抗侵彻性能。通过质量为10 g的 FSP破片对厚度为8、10、12、14、16以及18 mm 的六组 Kevlar 纤维靶板进行撞击模拟,获得了 FSP破片贯穿6组靶板的弹道极限,并分析了靶板的弹道极限、比吸收能随板厚的变化关系。结果表明,在板厚8-18 mm范围内,Kevlar纤维靶板的弹道极限随板厚的增加呈线性增长;在此范围内,靶板的比吸收能也呈近似线性增长,但在板厚为10-16 mm时,增长稍缓。对比还发现,比吸收能随板厚的变化规律与靶板面密度的变化规律几乎相同,二者都可用于描述Kevlar-129纤维复合材料靶板在 FSP 破片碰撞下比吸收能的变化。

  5. Ballistic Evaluation of Magnesium Alloy AZ31B

    Science.gov (United States)

    2007-04-01

    S. Burkins, and William A. Gooch Weapons and Materials Research Directorate, ARL Richard D. DeLorme Magnesium Elektron North America, Inc...ballistic properties. In order to fill this gap, the U.S. Army Research Laboratory (ARL) and Magnesium Elektron North America (MENA), Inc., conducted a...plate (H24 condition). The magnesium plate was alloyed, cast, rolled, thermally treated and tensile tested by Magnesium Elektron North America (MENA

  6. Influence of Material Properties on the Ballistic Performance of Ceramics for Personal Body Armour

    Directory of Open Access Journals (Sweden)

    Christian Kaufmann

    2003-01-01

    Full Text Available In support of improved personal armour development, depth of penetration tests have been conducted on four different ceramic materials including alumina, modified alumina, silicon carbide and boron carbide. These experiments consisted of impacting ceramic tiles bonded to aluminum cylinders with 0.50 caliber armour piercing projectiles. The results are presented in terms of ballistic efficiency, and the validity of using ballistic efficiency as a measure of ceramic performance was examined. In addition, the correlation between ballistic performance and ceramic material properties, such as elastic modulus, hardness, spall strength and Hugoniot Elastic Limit, has been considered.

  7. Investigation about the influence of the mechanical properties of lead core and brass jacket of a NATO 7.62 mm ball bullet in numerical simulations of ballistic impacts

    Directory of Open Access Journals (Sweden)

    Scapin M.

    2012-08-01

    Full Text Available In the present work a validated numerical approach has been used in order to build a robust and reliable FE model of the impact of a NATO 7.62 mm ball bullet, against an aluminium transmission shaft. The bullet is a full metal jacket type, with a lead alloy core and a brass jacket. Target shaft is made by an Al6061-T6 aluminium alloy. According to the soft core (lead alloy of the bullet, most effort has been spent in order to evaluate the effect of bullet materials mechanical properties on the numerical results. Numerical analyses, carried out using the non-linear dynamic finite element solver Abaqus∖Explicit 6.10, have been performed focusing on core and jacket material behaviour (target material, Al6061-T6, has been previously calibrated by the authors. Thus numerical analyses have been performed considering for the mechanical behaviour of the bullet both a simplified approach (as reported in literature and new material data (with strain rate effect obtained by means of experimental tests on the two materials (lead and brass with specimens cut directly from the bullet. Finally the results of the analyses have been compared with real experimental ballistic tests.

  8. Investigation about the influence of the mechanical properties of lead core and brass jacket of a NATO 7.62 mm ball bullet in numerical simulations of ballistic impacts

    Science.gov (United States)

    Giglio, M.; Gilioli, A.; Manes, A.; Peroni, L.; Scapin, M.

    2012-08-01

    In the present work a validated numerical approach has been used in order to build a robust and reliable FE model of the impact of a NATO 7.62 mm ball bullet, against an aluminium transmission shaft. The bullet is a full metal jacket type, with a lead alloy core and a brass jacket. Target shaft is made by an Al6061-T6 aluminium alloy. According to the soft core (lead alloy) of the bullet, most effort has been spent in order to evaluate the effect of bullet materials mechanical properties on the numerical results. Numerical analyses, carried out using the non-linear dynamic finite element solver Abaqus∖Explicit 6.10, have been performed focusing on core and jacket material behaviour (target material, Al6061-T6, has been previously calibrated by the authors). Thus numerical analyses have been performed considering for the mechanical behaviour of the bullet both a simplified approach (as reported in literature) and new material data (with strain rate effect) obtained by means of experimental tests on the two materials (lead and brass) with specimens cut directly from the bullet. Finally the results of the analyses have been compared with real experimental ballistic tests.

  9. Impact of Medical School Laboratory Courses and Physician Attitude on Test Use by House Staff.

    Science.gov (United States)

    Everett, George D.; And Others

    1983-01-01

    A study to assess the impact of laboratory courses in medical school on subsequent University of Iowa house staff test use, and to assess the influence of attitudinal factors on test use patterns is reported. Physician preferences for style, format, and timing of laboratory training sessions are examined. (MSE)

  10. The ballistic performance of the bombard Mons Meg

    Directory of Open Access Journals (Sweden)

    Ian Lewtas

    2016-04-01

    Full Text Available The bombard Mons Meg, located in Edinburgh Castle, with a diameter of 19 inches (48 cm, was one of the largest calibre cannons ever built. Constructed in 1449 and presented to King James II of Scotland in 1454, Mons Meg was used in both military and ceremonial roles in Scotland until its barrel burst in 1680. This paper examines the history, internal, external and terminal ballistics of the cannon and its shot. The likely muzzle velocity was estimated by varying the propellant type and the cannon profile was investigated to identify weak spots in the design that may have led to its failure. Using the muzzle velocity calculated from the internal ballistics, simulations were performed with granite and sandstone shot for varying launch angle and ground temperature. The likely trajectory and range of the cannonballs are described. The internal and external ballistics informed the initial conditions of the terminal ballistic impact scenarios. The performance of the cannonball against both period and modern targets, in the form of a pseudo-castle wall and a monolithic concrete target, respectively, were simulated and are presented and discussed.

  11. The ballistic performance of the bombard Mons Meg

    Institute of Scientific and Technical Information of China (English)

    Ian LEWTAS; Rachael MCALISTER; Adam WALLIS; Clive WOODLEY; Ian CULLIS

    2016-01-01

    The bombard Mons Meg, located in Edinburgh Castle, with a diameter of 19 inches (48 cm), was one of the largest calibre cannons ever built. Constructed in 1449 and presented to King James II of Scotland in 1454, Mons Meg was used in both military and ceremonial roles in Scotland until its barrel burst in 1680. This paper examines the history, internal, external and terminal ballistics of the cannon and its shot. The likely muzzle velocity was estimated by varying the propellant type and the cannon profile was investigated to identify weak spots in the design that may have led to its failure. Using the muzzle velocity calculated from the internal ballistics, simulations were performed with granite and sandstone shot for varying launch angle and ground temperature. The likely trajectory and range of the cannonballs are described. The internal and external ballistics informed the initial conditions of the terminal ballistic impact scenarios. The performance of the cannonball against both period and modern targets, in the form of a pseudo-castle wall and a monolithic concrete target, respectively, were simulated and are presented and discussed.

  12. One Dimensional Ballistic Electron Transport

    Directory of Open Access Journals (Sweden)

    Thomas K J

    2009-10-01

    Full Text Available Research in low-dimensional semiconductor systems over the last three decades has been largely responsible for the current progress in the areas of nanoscience and nanotechnology. The ability to control and manipulate the size, the carrier density, and the carrier type in two-, one-, and zero- dimensional structures has been widely exploited to study various quantum transport phenomena. In this article, a brief introduction is given to ballistic electron transport in one-dimensional quantum wires.

  13. Reference ballistic imaging database performance.

    Science.gov (United States)

    De Kinder, Jan; Tulleners, Frederic; Thiebaut, Hugues

    2004-03-10

    Ballistic imaging databases allow law enforcement to link recovered cartridge cases to other crime scenes and to firearms. The success of these databases has led many to propose that all firearms in circulation be entered into a reference ballistic image database (RBID). To assess the performance of an RBID, we fired 4200 cartridge cases from 600 9mm Para Sig Sauer model P226 series pistols. Each pistol fired two Remington cartridges, one of which was imaged in the RBID, and five additional cartridges, consisting of Federal, Speer, Winchester, Wolf, and CCI brands. Randomly selected samples from the second series of Remington cartridge cases and from the five additional brands were then correlated against the RBID. Of the 32 cartridges of the same make correlated against the RBID, 72% ranked in the top 10 positions. Likewise, of the 160 cartridges of the five different brands correlated against the database, 21% ranked in the top 10 positions. Generally, the ranking position increased as the size of the RBID increased. We obtained similar results when we expanded the RBID to include firearms with the same class characteristics for breech face marks, firing pin impressions, and extractor marks. The results of our six queries against the RBID indicate that a reference ballistics image database of new guns is currently fraught with too many difficulties to be an effective and efficient law enforcement tool.

  14. Impact of CLSI Breakpoint Changes on Microbiology Laboratories and Antimicrobial Stewardship Programs.

    Science.gov (United States)

    Heil, Emily L; Johnson, J Kristie

    2016-04-01

    In 2010, the Clinical and Laboratory Standards Institute (CLSI) lowered the MIC breakpoints for many beta-lactam antibiotics to enhance detection of known resistance amongEnterobacteriaceae The decision to implement these new breakpoints, including the changes announced in both 2010 and 2014, can have a significant impact on both microbiology laboratories and antimicrobial stewardship programs. In this commentary, we discuss the changes and how implementation of these updated CLSI breakpoints requires partnership between antimicrobial stewardship programs and the microbiology laboratory, including data on the impact that the changes had on antibiotic usage at our own institution.

  15. IMPACTS OF DRILLING ADDITIVES ON DATA OBTAINED FROM HYDROGEOLOGIC CHARACTERIZATION WELLS AT LOS ALAMOS NATIONAL LABORATORY

    Science.gov (United States)

    Personnel at the EPA Ground Water and Ecosystems Restoration Division (GWERD) were requested by EPA Region 6 to evaluate the impacts of well drilling practices at the Los Alamos National Laboratory (LANL). The focus of this review involved analysis of the impacts of bentonite- a...

  16. Hypervelocity Dust Impacts in Space and the Laboratory

    Science.gov (United States)

    Horanyi, Mihaly; Colorado CenterLunar Dust; Atmospheric Studies (CCLDAS) Team

    2013-10-01

    Interplanetary dust particles continually bombard all objects in the solar system, leading to the excavation of material from the target surfaces, the production of secondary ejecta particles, plasma, neutral gas, and electromagnetic radiation. These processes are of interest to basic plasma science, planetary and space physics, and engineering to protect humans and instruments against impact damages. The Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) has recently completed a 3 MV dust accelerator, and this talk will summarize our initial science results. The 3 MV Pelletron contains a dust source, feeding positively charged micron and sub-micron sized particles into the accelerator. We will present the technical details of the facility and its capabilities, as well as the results of our initial experiments for damage assessment of optical devices, and penetration studies of thin films. We will also report on the completion of our dust impact detector, the Lunar Dust Experiment (LDEX), is expected to be flying onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission by the time of this presentation. LDEX was tested, and calibrated at our dust accelerator. We will close by offering the opportunity to use this facility by the planetary, space and plasma physics communities.

  17. Comparing ballistic wounds with experiments on body simulator.

    Science.gov (United States)

    Bresson, F; Franck, O

    2010-05-20

    This paper demonstrates how ballistic experiments on body simulator can bring a key information in the forensic science field. In the investigated case, a hunter was shot by accident in the back. Two hunters were suspected of having inadvertently shot towards the victim. The deadly bullet left the body and cannot be found on the scene neither in the body. The only way to discriminate the two options was to perform ballistic tests in body simulators. Even though the knowledge about body simulators is not enough advanced yet to expect accurate quantitative results, it was supposed to fully discriminate the two investigated cases as its respective impact energy are highly different (respectively 1200J and 2400J). For each investigated possibility, bullet's expansion state and body wounds were simulated. Bullet impact characteristics were determined by measuring the muzzle velocity, compute the impact velocity in the considered range (the position of each hunter is accurately known). Reloading cartridges allowed to reproduce accuretaly the corresponding velocity. The body was simulated by 3 different means in order to explore the accuracy of the simulation process. We demonstrated that the reported case is situated in a velocity/energy range in which body simulators do not need to be particularly accurate to reproduce the bullet expansion/non-expansion state. It furthermore demonstrated that only one case is compatible with the ballistic wounds of the victim. In the other case, the bullet's expansion would lead to a completely different wound shape.

  18. A new approach in treating the ballistic coefficient in the differential correction fitting program

    Science.gov (United States)

    Barker, William N.; Eller, Thomas J.; Herder, Leland E.

    This paper describes the results of study to improve the accuracy of tracking and impact prediction special perturbations software in use at the Space Surveillance Center. First, historical data are considered for a wide range of decayed satellites. In general, this data indicate that the satellite ballistic coefficient (a model parameter in the directional correction process) varies as a function of time in the last days prior to decay. At present, this effect is not modeled and the ballistic coefficient is held constant over the differential correction observation span. The new approach presented here is a parameterization of the ballistic coefficient in the form of a simple linear function with time. The slope of this function is the time derivative of the ballistic coefficient which is treated as a new model parameter. Numerical results obtained from processing two important historical satellite decay cases are presented.

  19. Natural Mallow Fiber-Reinforced Epoxy Composite for Ballistic Armor Against Class III-A Ammunition

    Science.gov (United States)

    Nascimento, Lucio Fabio Cassiano; Holanda, Luane Isquerdo Ferreira; Louro, Luis Henrique Leme; Monteiro, Sergio Neves; Gomes, Alaelson Vieira; Lima, Édio Pereira

    2017-10-01

    Epoxy matrix composites reinforced with up to 30 vol pct of continuous and aligned natural mallow fibers were for the first time ballistic tested as personal armor against class III-A 9 mm FMJ ammunition. The ballistic efficiency of these composites was assessed by measuring the dissipated energy and residual velocity after the bullet perforation. The results were compared to those in similar tests of aramid fabric (Kevlar™) commonly used in vests for personal protections. Visual inspection and scanning electron microscopy analysis of impact-fractured samples revealed failure mechanisms associated with fiber pullout and rupture as well as epoxy cracking. As compared to Kevlar™, the mallow fiber composite displayed practically the same ballistic efficiency. However, there is a reduction in both weight and cost, which makes the mallow fiber composites a promising material for personal ballistic protection.

  20. Application of Super-Hydrophobic Coating for Enhanced Water Repellency of Ballistic Fabric

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Barton [ORNL; Rajic, Slobodan [ORNL; Hunter, Scott Robert [ORNL

    2014-10-01

    The objective of this work was to demonstrate that a superhydrophobic coating technology developed at Oak Ridge National Laboratory (ORNL) increases the water repellency of ballistic fabric beyond that provided by existing water repellency treatments. This increased water repellency has the potential to provide durable ballistic fabric for body armor without adding significant weight to the armor or significant manufacturing cost. Specimens of greige and scoured ballistic fabric were treated with a superhydrophobic coating and their weights and degree of water repellency were compared to specimens of untreated fabric. Treatment of both greige and scoured ballistic fabrics yielded highly water repellent fabrics. Our measurements of the water droplet contact angles gave values of approximately 150 , near the lower limit of 160 for superhydrophobic surfaces. The coatings increased the fabric weights by approximately 6%, an amount that is many times less than the estimated weight increase in a conventional treatment of ballistic fabric. The treated fabrics retained a significant amount of water repellency following a basic abrasion test, with water droplet contact angles decreasing by 14 to 23 . Microscopic analysis of the coating applied to woven fabrics indicated that the coating adhered equally well to fibers of greige and scoured yarns. Future evaluation of the superhydrophobic water repellent treatment will involve the manufacture of shoot packs of treated fabric for ballistic testing and provide an analysis of manufacturing scale-up and cost-to-benefit considerations.

  1. Ballistic transport in planetary ring systems due to particle erosion mechanisms. I - Theory, numerical methods, and illustrative examples

    Science.gov (United States)

    Durisen, Richard H.; Murphy, Brian W.; Cramer, Nichael Lynn; Cuzzi, Jeffrey N.; Mullikin, Thomas L.

    1989-01-01

    Ballistic transport, defined as the net radial transport of mass and angular momentum due to exchanges of meteoroid hypersonic-impact ejecta by neighboring planetary ring regions on time-scales orders-of-magnitude shorter than the age of the solar system, is presently considered as a problem in mathematical physics. The preliminary results of a numerical scheme for following the combined effects of ballistic transport and viscous diffusion demonstrate that ballistic transport generates structure near sharp edges already present in the ring-mass distribution; the entire ring system ultimately develops an undulatory structure whose length scale is typically of the order of the radial excursion of the impact ejecta.

  2. The Cooperative Ballistic Missile Defence Game

    NARCIS (Netherlands)

    Evers, L.; Barros, A.I.; Monsuur, H.

    2013-01-01

    The increasing proliferation of ballistic missiles and weapons of mass destruction poses new risks worldwide. For a threatened nation and given the characteristics of this threat a layered ballistic missile defence system strategy appears to be the preferred solution. However, such a strategy involv

  3. The Cooperative Ballistic Missile Defence Game

    NARCIS (Netherlands)

    Evers, L.; Barros, A.I.; Monsuur, H.

    2013-01-01

    The increasing proliferation of ballistic missiles and weapons of mass destruction poses new risks worldwide. For a threatened nation and given the characteristics of this threat a layered ballistic missile defence system strategy appears to be the preferred solution. However, such a strategy

  4. Impact of CLSI Breakpoint Changes on Microbiology Laboratories and Antimicrobial Stewardship Programs

    OpenAIRE

    2016-01-01

    In 2010, the Clinical and Laboratory Standards Institute (CLSI) lowered the MIC breakpoints for many beta-lactam antibiotics to enhance detection of known resistance among Enterobacteriaceae. The decision to implement these new breakpoints, including the changes announced in both 2010 and 2014, can have a significant impact on both microbiology laboratories and antimicrobial stewardship programs. In this commentary, we discuss the changes and how implementation of these updated CLSI breakpoin...

  5. Ballistic transport in Saturn's rings - An analytic theory

    Science.gov (United States)

    Lissauer, J. J.

    1984-01-01

    Ejecta from impacts of micrometeoroids on Saturn's ring particles will, in most cases, remain in orbit about Saturn and eventually be reaccreted by the rings, possibly at a different radial location. The resulting mass transport has been suggested as the cause of some of the features observed in Saturn's rings. Previous attempts to model this transport have used numerical simulations which have not included the effects of the angular momentum transport coincident with mass transport. An analytical model for ballistic mass transport in Saturn's rings is developed. The model includes the effects of angular momentum advection and shows that the net material movement due to angular momentum advection is comparable to that caused by direct ballistic mass transport.

  6. Ballistic superconductivity in semiconductor nanowires

    Science.gov (United States)

    Zhang, Hao; Gül, Önder; Conesa-Boj, Sonia; Nowak, Michał P.; Wimmer, Michael; Zuo, Kun; Mourik, Vincent; de Vries, Folkert K.; van Veen, Jasper; de Moor, Michiel W. A.; Bommer, Jouri D. S.; van Woerkom, David J.; Car, Diana; Plissard, Sébastien R.; Bakkers, Erik P. A. M.; Quintero-Pérez, Marina; Cassidy, Maja C.; Koelling, Sebastian; Goswami, Srijit; Watanabe, Kenji; Taniguchi, Takashi; Kouwenhoven, Leo P.

    2017-07-01

    Semiconductor nanowires have opened new research avenues in quantum transport owing to their confined geometry and electrostatic tunability. They have offered an exceptional testbed for superconductivity, leading to the realization of hybrid systems combining the macroscopic quantum properties of superconductors with the possibility to control charges down to a single electron. These advances brought semiconductor nanowires to the forefront of efforts to realize topological superconductivity and Majorana modes. A prime challenge to benefit from the topological properties of Majoranas is to reduce the disorder in hybrid nanowire devices. Here we show ballistic superconductivity in InSb semiconductor nanowires. Our structural and chemical analyses demonstrate a high-quality interface between the nanowire and a NbTiN superconductor that enables ballistic transport. This is manifested by a quantized conductance for normal carriers, a strongly enhanced conductance for Andreev-reflecting carriers, and an induced hard gap with a significantly reduced density of states. These results pave the way for disorder-free Majorana devices.

  7. Computational Analysis of the Compressible Flow Driven by a Piston in a Ballistic Range

    Institute of Scientific and Technical Information of China (English)

    G. Rajesh; R. Mishra; H. G. Kang; H. D. Kim

    2007-01-01

    The ballistic range has long been employed in a variety of engineering fields such as high-velocity impact engineering, projectile aerodynamics and aeroballistics, since it can create an extremely high-pressure state in very short time. Since the operation of the ballistic range includes many complicated phenomena, each process should be understood in detail for the performance enhancement of the device. One of the main processes which have significant influence on the device performance is the compression process of the driver gas. Most of the studies available in this field hardly discuss this phenomenon in detail and thus lack a proper understanding of its effect on the whole system performance. In the present study, a computational analysis has been made to investigate the fluid dynamic aspects of the compression process in the pump tube of a ballistic range and to assess how it affects the performance of the ballistic range, The results obtained are validated with the available experimental data. In order to evaluate the system performance, several performance parameters are defined. Effect of a shock tube added in between the pump tube and launch tube on the performance of the ballistic range is also studied analytically. Performance of the ballistic range could be significantly improved by the proper selection of the pump tube and high-pressure tube parameters and the addition of the shock tube.

  8. The impact of SLMTA in improving laboratory quality systems in the Caribbean Region

    Directory of Open Access Journals (Sweden)

    Giselle Guevara

    2014-09-01

    Full Text Available Background: Past efforts to improve laboratory quality systems and to achieve accreditation for better patient care in the Caribbean Region have been slow.Objective: To describe the impact of the Strengthening of Laboratory Management Toward Accreditation (SLMTA training programme and mentorship amongst five clinical laboratories in the Caribbean after 18 months.Method: Five national reference laboratories from four countries participated in the SLMTA programme that incorporated classroom teaching and implementation of improvement projects. Mentors were assigned to the laboratories to guide trainees on their improvement projects and to assist in the development of Quality Management Systems (QMS. Audits were conducted at baseline, six months, exit (at 12 months and post-SLMTA (at 18 months using the Stepwise Laboratory Quality Improvement Process Towards Accreditation (SLIPTA checklist to measure changes in implementation of the QMS during the period. At the end of each audit, a comprehensive implementation plan was developed in order to address gaps.Results: Baseline audit scores ranged from 19% to 52%, corresponding to 0 stars on the SLIPTA five-star scale. After 18 months, one laboratory reached four stars, two reached three stars and two reached two stars. There was a corresponding decrease in nonconformities and development of over 100 management and technical standard operating procedures in each of the five laboratories.Conclusion: The tremendous improvement in these five Caribbean laboratories shows that SLMTA coupled with mentorship is an effective, user-friendly, flexible and customisable approach to the implementation of laboratory QMS. It is recommended that other laboratories in the region consider using the SLMTA training programme as they engage in quality systems improvement and preparation for accreditation.

  9. Modeling and Simulation of Ballistic Penetration of Ceramic-Polymer-Metal Layered Systems

    Directory of Open Access Journals (Sweden)

    J. D. Clayton

    2015-01-01

    Full Text Available Numerical simulations and analysis of ballistic impact and penetration by tungsten alloy rods into composite targets consisting of layers of aluminum nitride ceramic tile(s, polymer laminae, and aluminum backing are conducted over a range of impact velocities on the order of 1.0 to 1.2 km/s. Computational results for ballistic efficiency are compared with experimental data from the literature. Simulations and experiments both demonstrate a trend of decreasing ballistic efficiency with increasing impact velocity. Predicted absolute residual penetration depths often exceed corresponding experimental values. The closest agreement between model and experiment is obtained when polymer interfaces are not explicitly represented in the numerical calculations, suggesting that the current model representation of such interfaces may be overly compliant. The present results emphasize the importance of proper resolution of geometry and constitutive properties of thin layers and interfaces between structural constituents for accurate numerical evaluation of performance of modern composite protection systems.

  10. Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms

    Science.gov (United States)

    Perera, Alokya P.; Bopegedera, A. M. R. P.

    2014-01-01

    The increase in ocean acidity since preindustrial times may have deleterious consequences for marine organisms, particularly those with calcareous structures. We present a laboratory experiment to investigate this impact with general, introductory, environmental, and nonmajors chemistry students. For simplicity and homogeneity, calcite was…

  11. Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms

    Science.gov (United States)

    Perera, Alokya P.; Bopegedera, A. M. R. P.

    2014-01-01

    The increase in ocean acidity since preindustrial times may have deleterious consequences for marine organisms, particularly those with calcareous structures. We present a laboratory experiment to investigate this impact with general, introductory, environmental, and nonmajors chemistry students. For simplicity and homogeneity, calcite was…

  12. Background Music in the Dissection Laboratory: Impact on Stress Associated with the Dissection Experience

    Science.gov (United States)

    Anyanwu, Emeka G.

    2015-01-01

    Notable challenges, such as mental distress, boredom, negative moods, and attitudes, have been associated with learning in the cadaver dissection laboratory (CDL). The ability of background music (BM) to enhance the cognitive abilities of students is well documented. The present study was designed to investigate the impact of BM in the CDL and on…

  13. Experimenting with Impacts in a Conceptual Physics or Descriptive Astronomy Laboratory

    Science.gov (United States)

    LoPresto, Michael C.

    2016-01-01

    What follows is a description of the procedure for and results of a simple experiment on the formation of impact craters designed for the laboratory portions of lower mathematical-level general education science courses such as conceptual physics or descriptive astronomy. The experiment provides necessary experience with data collection and…

  14. Background Music in the Dissection Laboratory: Impact on Stress Associated with the Dissection Experience

    Science.gov (United States)

    Anyanwu, Emeka G.

    2015-01-01

    Notable challenges, such as mental distress, boredom, negative moods, and attitudes, have been associated with learning in the cadaver dissection laboratory (CDL). The ability of background music (BM) to enhance the cognitive abilities of students is well documented. The present study was designed to investigate the impact of BM in the CDL and on…

  15. Inelastic deformation and failure of tungsten carbide under ballistic-loading conditions

    NARCIS (Netherlands)

    Hazell, P.J.; Appleby-Thomas, G.J.; Herlaar, K.; Painter, J.

    2010-01-01

    High-speed photography has been used to investigate the dynamic behaviour of similar grades of WC-Co hardmetals during ballistic impacts with velocities in the range of 28-484. m/s. Key features of the failure of similar grades of WC-Co materials during complimentary impacts have been observed and d

  16. Allegany Ballistics Lab: sensor test target system

    Science.gov (United States)

    Eaton, Deran S.

    2011-06-01

    Leveraging the Naval Surface Warfare Center, Indian Head Division's historical experience in weapon simulation, Naval Sea Systems Command commissioned development of a remote-controlled, digitally programmable Sensor Test Target as part of a modern, outdoor hardware-in-the-loop test system for ordnance-related guidance, navigation and control systems. The overall Target system design invokes a sciences-based, "design of automated experiments" approach meant to close the logistical distance between sensor engineering and developmental T&E in outdoor conditions over useful real world distances. This enables operating modes that employ broad spectrum electromagnetic energy in many a desired combination, variably generated using a Jet Engine Simulator, a multispectral infrared emitter array, optically enhanced incandescent Flare Simulators, Emitter/Detector mounts, and an RF corner reflector kit. As assembled, the recently tested Sensor Test Target prototype being presented can capably provide a full array of useful RF and infrared target source simulations for RDT&E use with developmental and existing sensors. Certain Target technologies are patent pending, with potential spinoffs in aviation, metallurgy and biofuels processing, while others are variations on well-established technology. The Sensor Test Target System is planned for extended installation at Allegany Ballistics Laboratory (Rocket Center, WV).

  17. A Comparative Study of Ballistic Resistance of Sandwich Panels with Aluminum Foam and Auxetic Honeycomb Cores

    Directory of Open Access Journals (Sweden)

    Shu Yang

    2013-01-01

    Full Text Available An innovative auxetic-cored sandwich panel (AXP is proposed. Its perforation resistant performance under high-velocity projectile impact was numerically analyzed using the validated finite element simulation techniques and compared with that of the aluminum foam-cored sandwich panel (AFP of identical dimensions and weight. It has been found that the AXP is far superior to the AFP in ballistic resistance because of the material concentration at the impacted area due to the negative Poisson's ratio (NPR effect. A parametric study was carried out to investigate the effects of several key parameters, including impact velocity, face and core thicknesses, and core density, on the ballistic resistance of the AXP and AFP. The results show that the ballistic limit and perforation energy of the AXP is greatly affected by these parameters. Meanwhile, the advantages of AXP over AFP being used as ballistic resistant structures are highlighted. The primary outcome of this research is new information on the development and design of advanced ballistic resistant structures containing auxetic materials.

  18. Preservation and storage of prepared ballistic gelatine.

    Science.gov (United States)

    Mattijssen, E J A T; Alberink, I; Jacobs, B; van den Boogaard, Y

    2016-02-01

    The use of ballistic gelatine, generally accepted as a human muscle tissue simulant in wound ballistic studies, might be improved by adding a preservative (Methyl 4-hydroxybenzoate) which inhibits microbial growth. This study shows that replacing a part of the gelatine powder by the preservative does not significantly alter the penetration depth of projectiles. Storing prepared blocks of ballistic gelatine over time decreased the penetration depth of projectiles. Storage of prepared gelatine for 4 week already showed a significant effect on the penetration depth of projectiles.

  19. Potential impact of a 2-person security rule on BioSafety Level 4 laboratory workers.

    Science.gov (United States)

    LeDuc, James W; Anderson, Kevin; Bloom, Marshall E; Carrion, Ricardo; Feldmann, Heinz; Fitch, J Patrick; Geisbert, Joan B; Geisbert, Thomas W; Holbrook, Michael R; Jahrling, Peter B; Ksiazek, Thomas G

    2009-07-01

    Directors of all major BioSafety Level 4 (BSL-4) laboratories in the United States met in 2008 to review the current status of biocontainment laboratory operations and to discuss the potential impact of a proposed 2-person security rule on maximum-containment laboratory operations. Special attention was paid to the value and risks that would result from a requirement that 2 persons be physically present in the laboratory at all times. A consensus emerged indicating that a video monitoring system represents a more efficient, economical standard; provides greater assurance that pathogens are properly manipulated; and offers an increased margin of employee safety and institutional security. The 2-person security rule (1 to work and 1 to observe) may decrease compliance with dual responsibilities of safety and security by placing undue pressure on the person being observed to quickly finish the work, and by placing the observer in the containment environment unnecessarily.

  20. Wave propagation in ballistic gelatine.

    Science.gov (United States)

    Naarayan, Srinivasan S; Subhash, Ghatu

    2017-01-23

    Wave propagation characteristics in long cylindrical specimens of ballistic gelatine have been investigated using a high speed digital camera and hyper elastic constitutive models. The induced transient deformation is modelled with strain rate dependent Mooney-Rivlin parameters which are determined by modelling the stress-strain response of gelatine at a range of strain rates. The varying velocity of wave propagation through the gelatine cylinder is derived as a function of prestress or stretch in the gelatine specimen. A finite element analysis is conducted using the above constitutive model by suitably defining the impulse imparted by the polymer bar into the gelatine specimen. The model results are found to capture the experimentally observed wave propagation characteristics in gelatine effectively.

  1. Ballistic Thermal Transfer in Nanosystems

    Directory of Open Access Journals (Sweden)

    A. A. Barinov

    2016-01-01

    Full Text Available This work is concerned with analysis of cross-plane thermal transfer in nanofilms.The paper presents a developed general model of phonon radiation transfer (EPRT based on the Boltzmann transport equation. The EPRT model assumes that the thermal transfer inside a dielectric or metal medium between two metal walls is maintained at different temperatures. These walls are like heat reservoirs; their surfaces are blackbodies. The paper first presents a model of the phonon radiation transfer of the absolute blackbodies in a wide range of temperatures where a model of the ballistic thermal transfer is applicable. It conducts a comparative analysis between phonon radiation transfer and electromagnetic radiation.The basic equation is a formula to calculate a phonon radiation intensity of the absolute blackbody depending on the temperature. Therefore, the formula for the total intensity of phonons is similar to the Stefan-Boltzmann law. The main difference of phonon radiation transfer is that a value of the phonon Stefan-Boltzmann constant is affected by temperature and properties of materials (average acoustic waves in solid bodies and Debye temperature. This can be seen from the curves for Si, Ge, and Diamond.The paper presents a received analytical equation for effective thermal conductivity using a heat flux in a cross-plane direction. The results obtained show the size and temperature dependences of the effective thermal conductivity of silicon, germanium and diamond nanofilms for the ballistic transport in the cross-plane direction. Finally, the paper compares the calculated results with those of available models of different foreign authors, which are in good compliance.

  2. Using the H Index to Assess Impact of DOE National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Springer, Everett P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-13

    The most readily accessible elements of the Emerald Matrix by quantitative measures are the knowledge and economy related measures. In this paper, the H Index for an institution will be used to assess STE impact, which is in the knowledge generation element. The H Index was developed by Hirsch (2005) as a measure of an individual’s scientific impact. The H Index is defined as the number of publications that have been cited h or more times for a given author. It has been generalized to organizations. Doing so leads to a complication in that H index scales with the number of publications. Although this may not be problematic when comparing individual researchers, it systematically favors larger institutions. Molinari and Molinari (2008) proposed an alternative index (hm) designed to assess organizational impact. It transforms the H Index for an organization into an impact index by removing a factor dependent on the number of publications. The hm provides another approach to compare institutions provided that differences in the citation patterns associated with fields of study are addressed. Kinney (2007) used the Molinari and Molinari (2008) approach to compare various scientific institutions in nonbiomedical research areas. Kinney (2007) used the Thomson Reuters Web of Science (WoS) as the source and used publications in nonbiomedical research areas, which is very important because the research areas of universities are much broader than say a DOE national laboratory. Also there are differences in citation rates for the various research fields that make comparisons between individuals or organizations difficult. The results from Kinney (2007) are given in Table 1 and indicate that the DOE national laboratories compare favorably with the selected universities in terms of impact (hm) in the research areas used in Kinney’s analysis. This report will compare hm for DOE national laboratories using an approach similar to Kinney (2007) providing a measure of impact of

  3. Review of Ballistic Limit Equations for Composite Structure Walls of Satellites

    Science.gov (United States)

    Schaefer, Frank K.*; Schneider, E.; Lambert, M.

    2004-08-01

    In this paper a review of existing ballistic limit equations for CFRP (Carbon Fibre Reinforced Plastics) structure walls of satellites is given, and two new ballistic limit equations are presented. The predictive capabilities of the equations are compared to a set of experimental hypervelocity impact test data of CFRP plates and CFRP honeycomb sandwich panels (satellite structure wall) from ENVISAT, AXAF, and a generic technology program. In the literature, three ballistic limit equations for sandwich panels (SP) made from CFRP face-sheets and Al- honeycomb (H/C) core were found and analyzed (Frost's approach, Approach using Christiansen's Whipple shield Ballistic Limit Equation (BLE), and Taylor's approach). Furthermore, in this paper, a new ballistic limit equation was proposed for CFRP H/C SP (Modified ESA Triple Wall Equation) and for composite panels (plates) with and without MLI attached to the surface. The amount of impact data on CFRP structure walls of satellites found in the literature was rather scarce. The new BLE for CFRP plates makes good predictions to the available set of test data. For the BLE for CFRP H/C SP, it was found that Frost's approach and application of Christiansen's BLE to CFRP H/C SP lead to an overprediction of the ballistic limit diameters for ENVISAT structure walls and the samples of the generic technology program. Taylor's approach and the newly designed MET ballistic limit equation have both yielded good predictions for all samples except for the AXAF samples that had rather thin-walled face-sheets and a thin Al H/C core: for these samples the predictions were conservative. Thus, for use in risk analysis tools for satellites (e. g. ESA's ESABASE/DEBRIS tool or NASA's BUMPER code), it is recommended to use either the MET or Taylor equation.

  4. Characterization of the ballistic limit curve for metallic Whipple shield

    Directory of Open Access Journals (Sweden)

    Lee M.

    2012-08-01

    Full Text Available It has been known that space debris or meteoroid impact damage can have significant effects on spacecraft. Experimental test has been conducted up to 7 km/s, and numerical simulations are performed at higher velocities. Studies on the hypervelocity impact onto single plate, double spaced plates (Whipple shield, and multiple plates (MS shield have been performed and ballistic limit curves (BLCs are proposed. Last 15 years SPH (Smoothed Particle Hydrodynamics has been applied to the hypervelocity impact problems because of cost of test and numerical efficiency especially in the hypervelocity impact regime. Although most of the simulations captured the debris shape well, somehow they do not seem to match well with the empirical ballistic limit curves. We have recently developed a new axisymmetric SPH hydrocode. In order to assess the confidence that should be placed in such simulations we simulated the hypervelocity impacts on aluminum Whipple shields and compared with the empirical BLCs. The SPH simulations indicated an improved accuracy compared with the previously published SPH simulation results. Other effort we put was using different types of equation of state, however no further improvement was achieved.

  5. The Impact of Differentiated Instructional Materials on English Language Learner (ELL) Students' Comprehension of Science Laboratory Tasks

    Science.gov (United States)

    Manavathu, Marian; Zhou, George

    2012-01-01

    Through a qualitative research design, this article investigates the impacts of differentiated laboratory instructional materials on English language learners' (ELLs) laboratory task comprehension. The factors affecting ELLs' science learning experiences are further explored. Data analysis reveals a greater degree of laboratory task comprehension…

  6. Estimation of ballistic block landing energy during 2014 Mount Ontake eruption

    Science.gov (United States)

    Tsunematsu, Kae; Ishimine, Yasuhiro; Kaneko, Takayuki; Yoshimoto, Mitsuhiro; Fujii, Toshitsugu; Yamaoka, Koshun

    2016-05-01

    The 2014 Mount Ontake eruption started just before noon on September 27, 2014. It killed 58 people, and five are still missing (as of January 1, 2016). The casualties were mainly caused by the impact of ballistic blocks around the summit area. It is necessary to know the magnitude of the block velocity and energy to construct a hazard map of ballistic projectiles and design effective shelters and mountain huts. The ejection velocities of the ballistic projectiles were estimated by comparing the observed distribution of the ballistic impact craters on the ground with simulated distributions of landing positions under various sets of conditions. A three-dimensional numerical multiparticle ballistic model adapted to account for topographic effect was used to estimate the ejection angles. From these simulations, we have obtained an ejection angle of γ = 20° from vertical to horizontal and α = 20° from north to east. With these ejection angle conditions, the ejection speed was estimated to be between 145 and 185 m/s for a previously obtained range of drag coefficients of 0.62-1.01. The order of magnitude of the mean landing energy obtained using our numerical simulation was 104 J.

  7. Economic Impact of Pacific Northwest National Laboratory on the State of Washington in Fiscal Year 2013

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Niemeyer, Jackie M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    Pacific Northwest National Laboratory (PNNL) is a large economic entity, with $1.06 billion in annual funding, $936 million in total spending, and 4,344 employees in fiscal year (FY) 2013. Four thousand, one hundred and one (4,101) employees live in Washington State. The Laboratory directly and indirectly supports almost $1.31 billion in economic output, 6,802 jobs, and $514 million in Washington State wage income from current operations. The state also gains more than $1.21 billion in output, more than 6,400 jobs, and $459 million in income through closely related economic activities, such as visitors, health care spending, spending by resident retirees, and spinoff companies. PNNL affects Washington’s economy through commonly recognized economic channels, including spending on payrolls and other goods and services that support Laboratory operations. Less-commonly recognized channels also have their own impacts and include company-supported spending on health care for its staff members and retirees, spending of its resident retirees, Laboratory visitor spending, and the economic activities in a growing constellation of “spinoff” companies founded on PNNL research, technology, and managerial expertise. PNNL also has a significant impact on science and technology education and community nonprofit organizations. PNNL is an active participant in the future scientific enterprise in Washington with the state’s K-12 schools, colleges, and universities. The Laboratory sends staff members to the classroom and brings hundreds of students to the PNNL campus to help train the next generation of scientists, engineers, mathematicians, and technicians. This investment in human capital, though difficult to measure in terms of current dollars of economic output, is among the important lasting legacies of the Laboratory. Finally, PNNL contributes to the local community with millions of dollars’ worth of cash and in-kind corporate and staff contributions, all of which

  8. Economic Impact of Pacific Northwest National Laboratory on the State of Washington in Fiscal Year 2013

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Michael J.; Niemeyer, Jackie M.

    2014-12-18

    Pacific Northwest National Laboratory (PNNL) is a large economic entity, with $1.06 billion in annual funding, $936 million in total spending, and 4,344 employees in fiscal year (FY) 2013. Four thousand, one hundred and one (4,101) employees live in Washington State. The Laboratory directly and indirectly supports almost $1.31 billion in economic output, 6,802 jobs, and $514 million in Washington State wage income from current operations. The state also gains more than $1.21 billion in output, more than 6,400 jobs, and $459 million in income through closely related economic activities, such as visitors, health care spending, spending by resident retirees, and spinoff companies. PNNL affects Washington’s economy through commonly recognized economic channels, including spending on payrolls and other goods and services that support Laboratory operations. Less-commonly recognized channels also have their own impacts and include company-supported spending on health care for its staff members and retirees, spending of its resident retirees, Laboratory visitor spending, and the economic activities in a growing constellation of “spinoff” companies founded on PNNL research, technology, and managerial expertise. PNNL also has a significant impact on science and technology education and community nonprofit organizations. PNNL is an active participant in the future scientific enterprise in Washington with the state’s K-12 schools, colleges, and universities. The Laboratory sends staff members to the classroom and brings hundreds of students to the PNNL campus to help train the next generation of scientists, engineers, mathematicians, and technicians. This investment in human capital, though difficult to measure in terms of current dollars of economic output, is among the important lasting legacies of the Laboratory. Finally, PNNL contributes to the local community with millions of dollars’ worth of cash and in-kind corporate and staff contributions, all of which

  9. Ballistic Applications of Glass and Kevlar Fibre Vinylester Composites

    Directory of Open Access Journals (Sweden)

    S. P. Panda

    1994-10-01

    Full Text Available Void-free E-glass and Kevlar-49 fibre reinforced vinylester laminates prepared under compression moulding were found to have Charpy impact strength of 576 KJlm2 and 304 KJlm2, respectively. Ballistic immunisation tests carried out on the glass reinforced vinylester laminates with thickness ranging from 12 mm to 54 mm against 7.62 mm rifle bullets produced an exponential relationship between the per cent attenuation in bullet velocity and the areal density of the laminates; whereas the relationship was linear for 9 mm carbine fire with laminate thicknessvarying from 5.5 mm to 12 mm .

  10. Design and Ballistic Performance of Hybrid Composite Laminates

    Science.gov (United States)

    Ćwik, Tomasz K.; Iannucci, Lorenzo; Curtis, Paul; Pope, Dan

    2016-10-01

    This paper presents an initial design assessment of a series of novel, cost-effective, and hybrid composite materials for applications involving high velocity impacts. The proposed hybrid panels were designed in order to investigate various physical phenomenon occurring during high velocity impact on compliant laminates from a previous study on Dyneema® and Spectra®. In the first, screening phase of the study twenty different hybrid composite laminates were impacted with 20 mm Fragment Simulating Projectiles at 1 km/s striking velocity. The best performing concepts were put forward to phase II with other hybrid concepts involving shear thickening fluids, commonly used in low velocity impacts. The results indicated that it is possible to design hybrid laminates of similar ballistic performance as the reference Dyneema® laminate, but with lower material costs. The optimal hybrid concept involves a fibre reinforced Polypropylene front and a Dyneema® backing.

  11. Ballistic Behaviour of Tempered Steel Armour Plates under Plane Strain Condition .

    OpenAIRE

    S. N. Dikshit

    1998-01-01

    The present investigation deals with the ballistic behaviour of tempered steel armour plates under plane strain condition at normal angle of attack. A conical-shaped steel projectile of 6.1 mmdiameter was impacted on 20 mm thick steel annour plates of 350, 450 and 550 Hv hardness, in the velocity range 200 -700 m/s at zero obliquity. Ballistic performance measured in terms of the depthof penetration indicates that, under plane strain condition, behavio1Do" f 550 Hv steel plate is better than ...

  12. Modeling and Simulation of Ceramic Arrays to Improve Ballistic Performance (Briefing charts)

    Science.gov (United States)

    2014-02-28

    center impact DOP can on be achieved If at a gap size of 0.508 mm -In simulation the adhesive layer improves the ballistic efficiency of the target...Projectile, 762x39 PS Projectile, SPH, Aluminum 5083, SiC, DoP Expeminets, AutoDyn Sin 16. SECURITY CLASSIFICATION OF: UU a. REPORT b. ABSTRACT c

  13. Comparison of analytic Whipple bumper shield ballistic limits with CTH simulations

    Energy Technology Data Exchange (ETDEWEB)

    Hertel, E.S. Jr.

    1993-05-01

    A series of CTH simulations were conducted to assess the feasibility of using the hydrodynamic code for debris cloud formation and to predict any damage due to the subsequent loading on rear structures. Six axisymmetric and one 3-dimensional simulations were conducted for spherical projectiles impacting Whipple bumper shields. The projectile diameters were chosen to correlate with two well known analytic expressions for the ballistic limit of a Whipple bumper shield. It has been demonstrated that CTH can be used to simulate the debris cloud formation, the propagation of the debris across a void region, and the secondary impact of the debris against a structure. In addition, the results from the CTH simulations were compared to the analytic estimates of the ballistic limit. At impact velocities of 10 km/s or less, the CTH predicted ballistic limit lays between the two analytic estimates. However, for impact velocities greater than 10 km/s, CTH simulations predicted a ballistic limit larger than both analytical estimates. The differences at high velocities are not well understood. Structural failure at late times due to the time integrated loading of a very diffuse debris cloud has not been considered in the CTH model. In addition, the analytic predictions are extrapolated from relatively low velocity data and the extrapolation technique may not be valid. The discrepancy between the two techniques should be investigated further.

  14. Ergonomics assessment of composite ballistic inserts for bullet- and fragment-proof vests.

    Science.gov (United States)

    Majchrzycka, Katarzyna; Brochocka, Agnieszka; Luczak, Anna; Lężak, Krzysztof

    2013-01-01

    Personal protective equipment worn by uniformed services (e.g., the police and the military) must ensure protection against bodily injuries. However, a high degree of protection is always associated with significant discomfort. This article presents the results of an assessment of the ergonomics parameters of new special purpose products, ballistic inserts with improved ballistic resistance, and an assessment of the impact of the burden related to their use on the psychomotor performance of the subjects. An obstacle course and subjective ergonomics assessment questionnaires were used in tests. Thermal discomfort was also assessed. Psychological testing included tests enabling an assessment of the subjects' cognitive and psychomotor performance, and a subjective assessment of mental load. The tests did not show any decrease in the comfort of use of the new inserts with improved ballistic resistance compared to the inserts currently used.

  15. Modeling and Simulation of Ballistic Penetration of Ceramic-Polymer-Metal Layered Systems

    Science.gov (United States)

    2016-01-01

    Jaromir Horacek Copyright © 2015 J. D. Clayton.This is an open access article distributed under the Creative Commons Attribution License, which permits...faces between layers may strongly influence performance of such systems under ballistic impact. However, the impor- tance of interfacial...experimental study of penetration resistance of ceramic armour subjected to projectile impact,” International Journal of Impact Engineering, vol. 32

  16. Practicing biology: Undergraduate laboratory research, persistence in science, and the impact of self-efficacy beliefs

    Science.gov (United States)

    Berkes, Elizabeth

    As undergraduate laboratory research internships become more popular and universities devote considerable resources towards promoting them, it is important to clarify what students specifically gain through involvement in these experiences and it is important to understand their impact on the science pipeline. By examining recent findings describing the primary benefits of undergraduate research participation, along with self-efficacy theory, this study aims to provide more explanatory power to the anecdotal and descriptive accounts regarding the relationship between undergraduate research experiences and interest in continuing in science. Furthermore, this study characterizes practices that foster students' confidence in doing scientific work with detailed description and analysis of the interactions of researchers in a laboratory. Phase 1 of the study, a survey of undergraduate biology majors (n=71) at a major research university, investigates the relationships among participation in biology laboratory research internships, biology laboratory self-efficacy strength, and interest in persisting in science. Phase 2 of the study, a two-year investigation of a university biology research laboratory, investigates how scientific communities of practice develop self-efficacy beliefs. The findings suggest that participation in lab internships results in increased interest in continuing in life science/biology graduate school and careers. They also suggest that a significant proportion of that interest is related to the students' biology laboratory self-efficacy. The findings of this study point to two primary ways that undergraduate research participation might work to raise self-efficacy strength. First, university research laboratory communities can provide students with a variety of resources that scaffold them into biology laboratory mastery experiences. Second, university research laboratory communities can provide students with coping and mastery Discourse models

  17. Economic Impact of Pacific Northwest National Laboratory on the State of Washington in Fiscal Year 2014

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Michael J.; Niemeyer, Jackie M.

    2015-11-09

    PNNL is a large economic entity with a total of 4,308 employees, $939 million (M) in total funding, and $1.02 billion (B) in total spending during FY 2014. The number of employees that live in Washington State is 4,026 or 93 percent of the Laboratory staff. he Laboratory directly and indirectly supported $1.45 billion in economic output, 6,832 jobs, and $517 million in Washington State wage income from current operations. The state also gained more than $1.19 billion in output, over 6,200 jobs, and $444 million in income through closely related economic activities such as visitors, health care spending, spending by resident retirees, and spinoff companies. PNNL affects Washington’s economy through commonly recognized economic channels, including spending on payrolls and other goods and services that support Laboratory operations. Less commonly recognized channels also have their own impacts and include company-supported spending on health care for its staff members and retirees, spending of its resident retirees, Laboratory visitor spending, and the economic activities in a growing constellation of “spinoff” companies founded on PNNL research, technology, and managerial expertise. PNNL also has a significant impact on science and technology education and community not-for-profit organizations. PNNL is an active participant in the future scientific enterprise in Washington with the state’s K-12 schools, colleges, and universities. The Laboratory sends staff members to the classroom and brings hundreds of students to the PNNL campus to help train the next generation of scientists, engineers, mathematicians, and technicians. This investment in human capital, though difficult to measure in terms of current dollars of economic output, is among the important lasting legacies of the Laboratory. Finally, PNNL contributes to the local community with millions of dollars’ worth of cash and in-kind corporate and staff contributions, all of which strengthen the

  18. Ballistic Energy Transport in Oligomers.

    Science.gov (United States)

    Rubtsova, Natalia I; Qasim, Layla N; Kurnosov, Arkady A; Burin, Alexander L; Rubtsov, Igor V

    2015-09-15

    The development of nanocomposite materials with desired heat management properties, including nanowires, layered semiconductor structures, and self-assembled monolayer (SAM) junctions, attracts broad interest. Such materials often involve polymeric/oligomeric components and can feature high or low thermal conductivity, depending on their design. For example, in SAM junctions made of alkane chains sandwiched between metal layers, the thermal conductivity can be very low, whereas the fibers of ordered polyethylene chains feature high thermal conductivity, exceeding that of many pure metals. The thermal conductivity of nanostructured materials is determined by the energy transport between and within each component of the material, which all need to be understood for optimizing the properties. For example, in the SAM junctions, the energy transport across the metal-chain interface as well as the transport through the chains both determine the overall heat conductivity, however, to separate these contributions is difficult. Recently developed relaxation-assisted two-dimensional infrared (RA 2DIR) spectroscopy is capable of studying energy transport in individual molecules in the time domain. The transport in a molecule is initiated by exciting an IR-active group (a tag); the method records the influence of the excess energy on another mode in the molecule (a reporter). The energy transport time can be measured for different reporters, and the transport speed through the molecule is evaluated. Various molecules were interrogated by RA 2DIR: in molecules without repeating units (disordered), the transport mechanism was expected and found to be diffusive. The transport via an oligomer backbone can potentially be ballistic, as the chain offers delocalized vibrational states. Indeed, the transport regime via three tested types of oligomers, alkanes, polyethyleneglycols, and perfluoroalkanes was found to be ballistic, whereas the transport within the end groups was diffusive

  19. Impact of virtual chemistry laboratory instruction on pre-service science teachers’ scientific process skills

    Directory of Open Access Journals (Sweden)

    Mutlu Ayfer

    2016-01-01

    Full Text Available This study aimed to investigate the impact of virtual chemistry laboratory instruction on pre-service science teachers’ scientific process skills. For this purpose, eight laboratory activities related to chemical kinetic, chemical equilibrium, thermochemistry, acids-bases, and electrochemistry were developed. Those activities were performed in virtual laboratory environment by the pre-service teachers in the experimental group and in the real laboratory environment by c the preservice teachers in the control group during eight weeks. Scientific process skills test developed by Burns, Okey and Wise [3], and translated into Turkish by Ateş and Bahar [2] was used before and after the instructions for data collection. According to results, while there was no significant difference between pre-test mean scores (U=133.500, p>0.05, significant difference between post-test mean scores was found in favour of experimental group (U=76.000, p<0.05. In addition, while no significant difference between pre-test mean scores for each sub-dimension was found, significant difference between post-test mean scores for designing investigation and formulating hypothesis skills was found in favour of experimental group.

  20. A Predictive Explicit Guidance Scheme for Ballistic Missiles

    Directory of Open Access Journals (Sweden)

    N. Prabhakar

    2013-09-01

    Full Text Available A new approach to the design of ballistic missile guidance is presented in this paper. The proposed method uses the missile model to predict the likely impact point at every guidance cycle and apply course corrections based on the predicted impact point (PIP deviations. The algorithm also estimates the in-flight thrust variation from nominal and accordingly updates the model to reduce the uncertainty in the prediction of the impact point. The performance of the algorithm is tested through 6-DOF simulation. The simulation results show excellent performance of the proposed guidance scheme in nominal & off nominal cases.Defence Science Journal, 2013, 63(5, pp.456-461, DOI:http://dx.doi.org/10.14429/dsj.63.2575

  1. Open-ended versus guided laboratory activities: Impact on students' beliefs about experimental physics

    CERN Document Server

    Wilcox, Bethany R

    2016-01-01

    Improving students' understanding of the nature of experimental physics is often an explicit or implicit goal of undergraduate laboratory physics courses. However, lab activities in traditional lab courses are typically characterized by highly structured, guided labs that often do not require or encourage students to engage authentically in the process of experimental physics. Alternatively, open-ended laboratory activities can provide a more authentic learning environment by, for example, allowing students to exercise greater autonomy in what and how physical phenomena are investigated. Engaging in authentic practices may be a critical part of improving students' beliefs around the nature of experimental physics. Here, we investigate the impact of open-ended activities in undergraduate lab courses on students' epistemologies and expectations about the nature of experimental physics, as well as their confidence and affect, as measured by the Colorado Learning Attitudes about Science Survey for Experimental Ph...

  2. BALLISTICS TESTING OF THE 9977 SHIPPING PACKAGE FOR STORAGE APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Loftin, B.; Abramczyk, G.; Koenig, R.

    2012-06-06

    Radioactive materials are stored in a variety of locations throughout the DOE complex. At the Savannah River Site (SRS), materials are stored within dedicated facilities. Each of those facilities has a documented safety analysis (DSA) that describes accidents that the facility and the materials within it may encounter. Facilities at the SRS are planning on utilizing the certified Model 9977 Shipping Package as a long term storage package and one of these facilities required ballistics testing. Specifically, in order to meet the facility DSA, the radioactive materials (RAM) must be contained within the storage package after impact by a .223 caliber round. In order to qualify the Model 9977 Shipping Package for storage in this location, the package had to be tested under these conditions. Over the past two years, the Model 9977 Shipping Package has been subjected to a series of ballistics tests. The purpose of the testing was to determine if the 9977 would be suitable for use as a storage package at a Savannah River Site facility. The facility requirements are that the package must not release any of its contents following the impact in its most vulnerable location by a .223 caliber round. A package, assembled to meet all of the design requirements for a certified 9977 shipping configuration and using simulated contents, was tested at the Savannah River Site in March of 2011. The testing was completed and the package was examined. The results of the testing and examination are presented in this paper.

  3. Analytical Scanning and Transmission Electron Microscopy of Laboratory Impacts on Stardust Aluminium Foils: Interpreting Impact Crater Morphology and the Composition of Impact Residues.

    Energy Technology Data Exchange (ETDEWEB)

    Kearsley, A T; Graham, G A; Burchell, M J; Cole, M J; Dai, Z R; Teslich, N; Chater, R; Wozniakiewicz, P A; Spratt, J; Jones, G

    2006-10-19

    The known encounter velocity (6.1kms{sup -1}) between the Stardust spacecraft and the dust emanating from the nucleus of comet Wild 2 has allowed realistic simulation of dust collection in laboratory experiments designed to validate analytical methods for the interpretation of dust impacts on the aluminium foil components of the Stardust collector. In this report we present information on crater gross morphology, the pre-existing major and trace element composition of the foil, geometrical issues for energy dispersive X-ray analysis of the impact residues in scanning electron microscopes, and the modification of dust chemical composition during creation of impact craters as revealed by analytical transmission electron microscopy. Together, these observations help to underpin the interpretation of size, density and composition for particles impacted upon the Stardust aluminium foils.

  4. The impact of light, noise, cage cleaning and in-house transport on welfare and stress of laboratory rats

    National Research Council Canada - National Science Library

    Castelhano-Carlos, M J; Baumans, V

    2009-01-01

    ... stressor, the animal's wellbeing is threatened. This review article summarizes several published studies on the impact of environmental factors such as light, noise, cage cleaning and in-house transport on welfare and stress of laboratory rats...

  5. Experimenting with impacts in a conceptual physics or descriptive astronomy laboratory

    Science.gov (United States)

    LoPresto, Michael C.

    2016-07-01

    What follows is a description of the procedure for and results of a simple experiment on the formation of impact craters designed for the laboratory portions of lower mathematical-level general education science courses such as conceptual physics or descriptive astronomy. The experiment provides necessary experience with data collection and analysis as well as practice with quantitative skills such as measurement and calculation in a manner that does not exceed the mathematical scope of the courses while, due to its hands-on nature and interesting topic, remaining engaging.

  6. Reverse Ballistic Air Gun Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This custom-designed facility houses a suite of three air guns capable of generating accelerations up to 100,000 Gs and velocities up to 2,000 ft/s. In addition to a...

  7. Reverse Ballistic Air Gun Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This custom-designed facility houses a suite of three air guns capable of generating accelerations up to 100,000 Gs and velocities up to 2,000 ft/s. In addition to...

  8. Analysis of Radiation Impact on White Mice through Radiation Dose Mapping in Medical Physics Laboratory

    Science.gov (United States)

    Sutikno, Madnasri; Susilo; Arya Wijayanti, Riza

    2016-08-01

    A study about X-ray radiation impact on the white mice through radiation dose mapping in Medical Physic Laboratory is already done. The purpose of this research is to determine the minimum distance of radiologist to X-ray instrument through treatment on the white mice. The radiation exposure doses are measured on the some points in the distance from radiation source between 30 cm up to 80 with interval of 30 cm. The impact of radiation exposure on the white mice and the effects of radiation measurement in different directions are investigated. It is founded that minimum distance of radiation worker to radiation source is 180 cm and X-ray has decreased leukocyte number and haemoglobin and has increased thrombocyte number in the blood of white mice.

  9. M and D SIG progress report: Laboratory simulations of LDEF impact features

    Science.gov (United States)

    Horz, Friedrich; Bernhard, R. P.; See, T. H.; Atkinson, D.; Allbrooks, M.

    1992-01-01

    Laboratory impact experiments are needed to understand the relationship between a measured penetration hole diameter and associated projectile dimension in the thermal blankets of experiment A0178, which occupied some 16 sq. m. These blankets are composed of 125 micron thick Teflon that has an Ag/enconel second mirror surface, backed by organic binder and Chemglaze paint for a total thickness of some 170 microns. While dedicated experiments are required to understand the penetration behavior of this compound target in detail, we report here on impact simulations sponsored by other projects into pure Teflon and aluminum targets. These experiments will allow first order interpretations of impact features on the Long Duration Exposure Facility (LDEF), and they will serve as guides for dedicated experiments that employ the real LDEF blankets, both exposed and unexposed, for a refined understanding of the LDEF's collisional environment. We employed a light gas gun to launch soda-lime glass spheres from 50 to 3200 microns in diameter that impacted targets of variable thickness. Penetration measurements are given.

  10. Laboratory device to analyse the impact of soil properties on electrical and thermal conductivity

    Science.gov (United States)

    Bertermann, David; Schwarz, Hans

    2017-04-01

    Gathering information about soil properties in an efficient way is essential for many soil applications also for very shallow geothermal systems (e.g. collector systems or heat baskets). In the field, electrical resistivity tomogramphy measurements enable non-invasive and extensive analyses regarding the determination of soil properties. For a better understanding of measured electrical resistivity values in relation to soil properties within this study, a laboratory setup was developed. The structure of this laboratory setup is geared to gather electrical resistivity or rather electrical conductivity values which are directly comparable to data measured in the field. Within this setup grain size distribution, moisture content, and bulk density, which are the most important soil parameters affecting the electrical resistivity, can be adjusted. In terms of a better estimation of the geothermal capability of soil, thermal conductivity measurements were also implemented within the laboratory test sequence. The generated data reveals the serious influence of the water content and also provides a huge impact of the bulk density on the electrical as well as on the thermal conductivity. Furthermore, different behaviour patterns of electrical and thermal conductivity in their particular relation to the different soil parameters could be identified.

  11. The Ballistic Cart on an Incline Revisited.

    Science.gov (United States)

    Serway, Raymond A.; And Others

    1995-01-01

    Presents the theory behind the mechanics demonstration that involves projecting a ball vertically upward from a ballistic cart moving along an inclined plane. The measured overshoot is believed to be due, in part, to the presence of rolling friction and the inertial properties of the cart wheels. (JRH)

  12. The Internal Ballistics of an Air Gun

    Science.gov (United States)

    Denny, Mark

    2011-01-01

    The internal ballistics of a firearm or artillery piece considers the pellet, bullet, or shell motion while it is still inside the barrel. In general, deriving the muzzle speed of a gunpowder firearm from first principles is difficult because powder combustion is fast and it very rapidly raises the temperature of gas (generated by gunpowder…

  13. The Internal Ballistics of an Air Gun

    Science.gov (United States)

    Denny, Mark

    2011-01-01

    The internal ballistics of a firearm or artillery piece considers the pellet, bullet, or shell motion while it is still inside the barrel. In general, deriving the muzzle speed of a gunpowder firearm from first principles is difficult because powder combustion is fast and it very rapidly raises the temperature of gas (generated by gunpowder…

  14. Graphene Triangular Ballistic Rectifier: Fabrication and Characterisation

    Science.gov (United States)

    Auton, Gregory; Kumar, Roshan Krishna; Hill, Ernie; Song, Aimin

    2016-09-01

    It has been shown that graphene can demonstrate ballistic transport at room temperature. This opens up a range of practical applications that do not require graphene to have a band gap, which is one of the most significant challenges for its use in the electronics industry. Here, the very latest high mobility graphene (>100,000 cm2 V-1 s-1) fabrication techniques will be demonstrated so that one such device, called the triangular ballistic rectifier (TBR), can be characterised. The TBR is a four-terminal device with a triangular anti-dot at their intersection; two sides of the triangle are positioned and angled such that ballistic carriers from the two input electrodes are redirected like billiard balls to one of the two output contacts irrespective of the instantaneous polarity of the input. A responsivity of 2400 mV mW-1 is demonstrated at room temperature from a low-frequency input signal. The ballistic nature of the device is justified and explained in more detail with low-temperature measurements.

  15. The Ballistic Cart on an Incline Revisited.

    Science.gov (United States)

    Serway, Raymond A.; And Others

    1995-01-01

    Presents the theory behind the mechanics demonstration that involves projecting a ball vertically upward from a ballistic cart moving along an inclined plane. The measured overshoot is believed to be due, in part, to the presence of rolling friction and the inertial properties of the cart wheels. (JRH)

  16. First Soviet Sea-Launched Ballistic Rockets

    Directory of Open Access Journals (Sweden)

    Yuri F. Katorin

    2013-03-01

    Full Text Available In the article it is told about the creation of the first generation of Soviet ballistic missiles for the armament of submarines. The basic stages of their development, tests and adoption for the armament are described. Are cited the data about the people, is most which actively participated in these processes.

  17. Electron Interference in Ballistic Graphene Nanoconstrictions

    DEFF Research Database (Denmark)

    Baringhaus, Jens; Settnes, Mikkel; Aprojanz, Johannes

    2016-01-01

    We realize nanometer size constrictions in ballistic graphene nanoribbons grown on sidewalls of SiC mesa structures. The high quality of our devices allows the observation of a number of electronic quantum interference phenomena. The transmissions of Fabry-Perot-like resonances are probed...

  18. Optimization theory for ballistic energy conversion

    NARCIS (Netherlands)

    Xie, Yanbo; Versluis, Michel; Van Den Berg, Albert; Eijkel, Jan C.T.

    2016-01-01

    The growing demand of renewable energy stimulates the exploration of new materials and methods for clean energy. We recently demonstrated a high efficiency and power density energy conversion mechanism by using jetted charged microdroplets, termed as ballistic energy conversion. Hereby, we model and

  19. Principles of ballistics applicable to the treatment of gunshot wounds.

    Science.gov (United States)

    Swan, K G; Swan, R C

    1991-04-01

    Ballistics is the science of the motion of a projectile through the barrel of a firearm (internal ballistics), during its subsequent flight (external ballistics), and during its final complicated motion after it strikes a target (terminal ballistics). Wound ballistics is a special case of terminal ballistics. Although wound ballistics is at best sets of approximations, its principles enter usefully into an evaluation of a gunshot wound and its treatment. A special consideration in these cases is their medicolegal aspects. At a minimum, the medical team receiving the patient should exert care not to destroy the clothing and in particular to cut around and not through bullet holes, to turn over to law enforcement officials any metallic foreign body recovered from the patient, and to describe precisely, or even to photograph, any entrance or exit wounds.

  20. Final Report for the Arroyo Las Positas Maintenance Impact Study, Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    van Hattem, M; Paterson, L

    2006-01-12

    In 2000, the Lawrence Livermore National Laboratory's (LLNL) Environmental Protection Department, in coordination with Plant Engineering (PE), began dredging sections of the Arroyo Las Positas (ALP) to alleviate concerns about flooding of sensitive facilities within the mainsite of Lawrence Livermore National Laboratory. In order to reduce potential impacts on the federally threatened California red-legged frog (Rana aurora draytonii), LLNL proposed to dredge sections of the ALP in a ''checkerboard pattern'', resulting in a mosaic of open water habitat and vegetated sections (Figure 1). The Arroyo Las Positas Management Plan (Plan) was coordinated with both state and federal agencies including the U.S. Fish and Wildlife Service (USFWS), California Department of Fish and Game (CDF&G), San Francisco Regional Water Quality Control Board (SFRWQCB), and the Army Corp of Engineers (ACOE). Water Discharge Requirements (WDRs) were issued for this project on December 30, 1999 (Order No. 99-086) by the SFRWQCB. Provision 19 of the WDRs outlined a five-year (2000 through 2004) Maintenance Impact Study (MIS) that LLNL began in coordination with dredging work that was conducted as part of the Arroyo Las Positas Management Plan. Provision 20 of these WDRs requires LLNL to submit a final report of the results of the Maintenance Impact Study for this project to the SFRWQCB. The purpose of this report is to present the results of the Maintenance Impact Study for Arroyo Las Positas and meet the requirements of Provision 20. A description of the annual monitoring included in this Maintenance Impact Study is included in the methods section of this report. Initially the Plan called for dredging the entire length of the Arroyo Las Positas (approximately 6,981 linear feet) over a 5-year period to minimize temporal impacts on the California red-legged frog. Dredging occurred in 2000 ({approx}1,300 ft.), 2001 ({approx}800 ft.), and 2002 ({approx}1,200 ft.), which

  1. Molecular Dynamics Studies on Ballistic Thermal Resistance of Graphene Nano-Junctions

    Science.gov (United States)

    Yao, Wen-Jun; Cao, Bing-Yang

    2015-05-01

    Ballistic thermal resistance of graphene nano-junctions is investigated using non-equilibrium molecular dynamics simulation. The simulation system is consisted of two symmetrical trapezoidal or rectangular graphene nano-ribbons (GNRs) and a connecting nanoscale constriction in between. From the simulated temperature profile, a big temperature jump resulted from the constriction is found, which is proportional to the heat current and corresponds to a local ballistic thermal resistance. Fixing the constriction width and the length of GNRs, this ballistic thermal resistance is independent of the width of the GNRs bottom layer, i.e., the convex angle. But interestingly, this thermal resistance has obvious size effect. It is inversely proportional to the constriction width and will disappear with the constriction being wider. Moreover, based on the phonon dynamics theory, a theoretical model of the ballistic thermal resistance in two-dimensional nano-systems is developed, which gives a good explanation on microcosmic level and agrees well with the simulation result quantitatively and qualitatively. Supported by the National Natural Science Foundation of China under Grant Nos. 51322603, 51136001, 51356001, Science Fund for Creative Research Groups (No. 51321002), the Program for New Century Excellent Talents in University, Tsinghua University Initiative Scientific Research Program, the Tsinghua National Laboratory for Information Science and Technology of China

  2. Ballistic trauma from an exploding electronic cigarette: Case report

    Directory of Open Access Journals (Sweden)

    Christopher Ban, DMD

    2017-09-01

    Full Text Available Electronic cigarettes (e-cigarettes first became available in the United States in 2007, and since that time, the number of e-cigarette users in the US has grown to over 2.5 million. During the period from 2010–2013 alone, the percentage of Americans who reported that they had ever used electronic cigarettes more than doubled from 3.3% to 8.5%. This number will continue to grow, as the use of electronic cigarettes as an alternative to smoking and in smoking cessation is being explored by the public and medical professionals alike. This article presents a case report involving a patient who was injured when the electronic cigarette he was smoking exploded in his face, causing a ballistic injury to his maxilla, as well as a series of other associated injuries. There have been several recent reports in the literature of exploding electronic cigarettes. This article presents a case of avulsive injury due to ballistic trauma with associated impaction of the vaporizing device.

  3. Improving Ballistic Performance of Polyurethane Foam by Nanoparticle Reinforcement

    Directory of Open Access Journals (Sweden)

    M. F. Uddin

    2009-01-01

    Full Text Available We report improving ballistic performance of polyurethane foam by reinforcing it with nanoscale TiO2 particles. Particles were dispersed through a sonic cavitation process and the loading of particles was 3 wt% of the total polymer. Once foams were reinforced, sandwich panels were made and impacted with fragment simulating projectiles (FSPs in a 1.5-inch gas gun. Projectile speed was set up to have complete penetration of the target in each experiment. Test results have indicated that sandwich with nanophased cores absorbed about 20% more kinetic energy than their neat counterpart. The corresponding increase in ballistic limit was around 12% over the neat control samples. The penetration phenomenon was also monitored using a high-speed camera. Analyses of digital images showed that FSP remained inside the nanophased sandwich for about 7 microseconds longer than that of a neat sandwich demonstrating improved energy absorption capability of the nanoparticle reinforced core. Failure modes for energy absorption have been investigated through a microscope and high-speed images.

  4. Influence of Polymer Restraint on Ballistic Performanceof Alumina Ceramic Tiles

    Directory of Open Access Journals (Sweden)

    P.R.S. Reddy

    2008-03-01

    Full Text Available An experimental study has been carried out to evaluate the influence of confinement ofalumina ceramic tiles through polymer restraint, on its ballistic performance. Tiles of 99.5 per centpurity alumina were subjected to ballistic impact against 7.62 mm armour piercing projectiles atvelocities of about 820 m/s. The tiles of size 75 mm x 75 mm x 7 mm were confined on both facesby effectively bonding varying numbers of layers of polymer fabrics. These were then bondedto a 10 mm thick fibre glass laminate as a backing using epoxy resin. High performance polyethyleneand aramid polymer fabrics were used in the current set of experiments for restraining the tiles.Comparative effects of confinement on energy absorption of tiles with varied number of layersof fabrics were evaluated. It was observed that by providing effective confinement to the tile,energy absorption could be doubled with increase in areal density by about 13 per cent.Photographs of the damage and the effects of restraint on improvement in energy absorptionof ceramic tiles are presented and discussed.

  5. Development of a New Armor Steel and its Ballistic Performance

    Directory of Open Access Journals (Sweden)

    S. Hakan Atapek

    2013-05-01

    Full Text Available In this study, a boron added armor steel was developed according to standard rolled homogenous armor steel, MIL-A-12560, and metallographic-fractographic examinations were carried out to understand its deformation characteristics and perforation mode after interaction with a 7.62 mm armor piercing projectile. The microstructure of the developed steel was characterized by light and scanning electron microscope to evaluate its matrix after application of several heat treatments consisting of austenization, quenching and tempering. The mechanical properties of the developed steel were determined by tensile test at room temperature and notched impact test at -40 ºC. The ballistic performance of developed steel was determined by its V50 ballistic protection limit according to MIL-STD-662F standard and it was found to be higher than that of MIL-A-12560 steel. After perforation deformation induced adiabatic shear bands, that have an important role on the crack nucleation, were observed close to the penetration in the etched steel and perforation occurred by typical ductile hole enlargement with certain radial flows.Defence Science Journal, 2013, 63(3, pp.271-277, DOI:http://dx.doi.org/10.14429/dsj.63.1341

  6. Environmental impact report addendum for the continued operation of Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Weston, R. F. [Roy F. Weston, Inc. (United States)

    1996-10-01

    An environmental impact statement/environmental impact report (ES/EIR) for the continued operation and management of Lawrence Livermore National Laboratory (LLNL) was prepared jointly by the U.S. Department of Energy (DOE) and the University of California (UC). The scope of the document included near-term (within 5-10 years) proposed projects. The UC Board of Regents, as state lead agency under the California Environmental Quality Act (CEQA), certified and adopted the EIR by issuing a Notice of Determination on November 20, 1992. The DOE, as the lead federal agency under the National Environmental Policy Act (NEPA), adopted a Record of Decision for the ES on January 27, 1993 (58 Federal Register [FR] 6268). The DOE proposed action was to continue operation of the facility, including near-term proposed projects. The specific project evaluated by UC was extension of the contract between UC and DOE for UC`s continued operation and management of LLNL (both sites) from October 1, 1992, through September 30, 1997. The 1992 ES/EIR analyzed impacts through the year 2002. The 1992 ES/EIR comprehensively evaluated the potential environmental impacts of operation and management of LLNL within the near-term future. Activities evaluated included programmatic enhancements and modifications of facilities and programs at the LLNL Livermore site and at LLNL`s Experimental Test Site (Site 300) in support of research and development missions 2048 established for LLNL by Congress and the President. The evaluation also considered the impacts of infrastructure and building maintenance, minor modifications to buildings, general landscaping, road maintenance, and similar routine support activities.

  7. Quantifying Uncertainty from Computational Factors in Simulations of a Model Ballistic System

    Science.gov (United States)

    2017-08-01

    ARL-TR-8074 ● AUG 2017 US Army Research Laboratory Quantifying Uncertainty from Computational Factors in Simulations of a Model...Uncertainty from Computational Factors in Simulations of a Model Ballistic System by Daniel J Hornbaker Weapons and Materials Research...penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM

  8. Ballistic Evaluation of rolled Homogeneous Steel Armor with Tungsten Carbide and Titanium Carbide Facing.

    Science.gov (United States)

    1960-12-01

    LABORATORIES BALLISTIC EVALUATION OF ROLLED HMtOGE14EOUS STEEL ASWKR f VITH TUNGSTEN CARBIDE AND TITANIUM CARBIDE FACING (U) TECHNICAL REPORT NO. WAL...carbide steel and titanium carbide steel composite armor when attacked by cal. .40 H19B WC cores, cal. .0 AP W2 projectiles, ZOIN fragment simulating...determine the effectiveness of tungsten car- bide (WC) and titanium carbide (TIC) facing on steel armor for the defeat of steel and tungsten carbide

  9. Reassessing the Representative Heuristic of the Plywood Ballistic Mannequin Used in Live-Fire Testing

    Science.gov (United States)

    2015-04-01

    Inappropriate 33 Appendix B. The American Plywood Association ( APA ) Wood Species Grouping 37 Appendix C. US Army Ballistic Research Laboratory (BRL) Plywood...in a static formation to simulate a Soviet main battle tank battalion, BRL used these same mannequins for PVA.14 The average stature of the Russian...PS 1-09, structural plywood. Tacoma (WA): APA , The Engineered Wood Association Headquarters; 2010 Jun. [accessed 12 Jun 2014]. www.apawood.org. 7

  10. Impact of flow velocity on biochemical processes – a laboratory experiment

    Directory of Open Access Journals (Sweden)

    A. Boisson

    2014-08-01

    Full Text Available Understanding and predicting hydraulic and chemical properties of natural environments are current crucial challenges. It requires considering hydraulic, chemical and biological processes and evaluating how hydrodynamic properties impact on biochemical reactions. In this context, an original laboratory experiment to study the impact of flow velocity on biochemical reactions along a one-dimensional flow streamline has been developed. Based on the example of nitrate reduction, nitrate-rich water passes through plastic tubes at several flow velocities (from 6.2 to 35 mm min−1, while nitrate concentration at the tube outlet is monitored for more than 500 h. This experimental setup allows assessing the biologically controlled reaction between a mobile electron acceptor (nitrate and an electron donor (carbon coming from an immobile phase (tube that produces carbon during its degradation by microorganisms. It results in observing a dynamic of the nitrate transformation associated with biofilm development which is flow-velocity dependent. It is proposed that the main behaviors of the reaction rates are related to phases of biofilm development through a simple analytical model including assimilation. Experiment results and their interpretation demonstrate a significant impact of flow velocity on reaction performance and stability and highlight the relevance of dynamic experiments over static experiments for understanding biogeochemical processes.

  11. Space Weathering in Houston: A Role for the Experimental Impact Laboratory at JSC

    Science.gov (United States)

    Cintala, M. J.; Keller, L. P.; Christoffersen, R.; Hoerz, F.

    2015-01-01

    The effective investigation of space weathering demands an interdisciplinary approach that is at least as diversified as any other in planetary science. Because it is a macroscopic process affecting all bodies in the solar system, impact and its resulting shock effects must be given detailed attention in this regard. Direct observation of the effects of impact is most readily done for the Moon, but it still remains difficult for other bodies in the solar system. Analyses of meteorites and precious returned samples provide clues for space weathering on asteroids, but many deductions arising from those studies must still be considered circumstantial. Theoretical work is also indispensable, but it can only go as far as the sometimes meager data allow. Experimentation, however, can permit near real-time study of myriad processes that could contribute to space weathering. This contribution describes some of the capabilities of the Johnson Space Center's Experimental Impact Laboratory (EIL) and how they might help in understanding the space weathering process.

  12. Use of an image converter camera for analysis of ballistic resistance of lightweight armor materials

    Science.gov (United States)

    van Bree, J. L.; van Riet, E. J.

    1991-04-01

    Experiments to measure the ballistic resistance of light weight armour materials normally comprise the determination of the ballistic limit velocity V50 for a standardized fragment simulating projectile. However, in order to characterize these materials in more detail, it is of great interest to know the dynamic response of armour materials at impact. To this end, high speed photography is used to monitor target behaviour during impact and subsequent perforation in a timeresolved manner. Moreover, in the field of personal protection it is of importance to know the maximum temporary indentation for nonpenetrating projectiles at impact velocities near the critical V50 velocity as a parameter for trauma-effect. Experiments, making use of a Imacon camera, are described in which materials for light weight armour applications were screened.

  13. Analytical scanning and transmission electron microscopy of laboratory impacts on Stardust aluminum foils: interpreting impact crater morphology and the composition of impact residues

    CERN Document Server

    Kearsley, A T; Burchell, M J; Cole, M J; Dai, Z R; Teslich, N; Bradley, J P; Chater, R; Wozniakiewicz, P A; Spratt, J; Jones, G

    2006-01-01

    The known encounter velocity (6.1kms-1) and particle incidence angle (perpendicular) between the Stardust spacecraft and the dust emanating from the nucleus of comet Wild 2 fall within a range that allows simulation in laboratory light gas gun experiments designed to validate analytical methods for the interpretation of dust impacts on the aluminum foil components of the Stardust collector. Buckshot of a wide size, shape and density range of mineral, glass, polymer and metal grains, have been fired to impact perpendicularly upon samples of Stardust Al1100 foil, tightly wrapped onto aluminium alloy plate as an analogue of foil on the spacecraft collector. We have not yet been able to produce laboratory impacts by projectiles with weak and porous aggregate structure, as may occur in some cometary dust grains. In this report we present information on crater gross morphology and its dependence on particle size and density, the pre-existing major and trace element composition of the foil, geometrical issues for en...

  14. The use of instrumented mobile laboratories to determine gaseous pollutant impacts

    Energy Technology Data Exchange (ETDEWEB)

    Cunnigham, J.E.

    1983-06-01

    Mobile sampling laboratories have been used by the Texas Air Control Board (TACB) to detect and measure the gaseous pollutant impacts from point sources. Mobile sampling enables one to locate zones of relatively high levels of air contaminants and take measurements for any desirable time period. Two types of measurements can be made. The first type is the determination of plume cross-section concentration profile. These measurements are taken while driving the van at a constant speed on a road perpendicular to the direction of plume transport. The second type of measurement is a stationary sample made by monitoring the pollutant concentrations for some time period with the van located at one point. A plume cross-section measurement is made to locate the local point of maximum concentration where stationary sampling may be done most efficaciously.

  15. Impactful times memories of 60 years of shock wave research at Sandia National Laboratories

    CERN Document Server

    Asay, James R; Lawrence, R Jeffery; Sweeney, Mary Ann

    2017-01-01

    This book presents a history of shock compression science, including development of experimental, material modeling, and hydrodynamics code technologies over the past six decades at Sandia National Laboratories. The book is organized into a discussion of major accomplishments by decade with over 900 references, followed by a unique collection of 45 personal recollections detailing the trials, tribulations, and successes of building a world-class organization in the field. It explains some of the challenges researchers faced and the gratification they experienced when a discovery was made. Several visionary researchers made pioneering advances that integrated these three technologies into a cohesive capability to solve complex scientific and engineering problems. What approaches worked, which ones did not, and the applications of the research are described. Notable applications include the turret explosion aboard the USS Iowa and the Shoemaker-Levy comet impact on Jupiter. The personal anecdotes and recollec...

  16. Impacts of microcystin, a cyanobacterial toxin, on laboratory rodents in vivo

    Directory of Open Access Journals (Sweden)

    Andrea Ziková

    2008-01-01

    Full Text Available Cyanobacterial water blooms became a global problem/issue because beside a dramatic deterioration of water quality parameters they also produce cyanobacterial toxins being harmful for animals and humans. Cyanotoxins especially the most prominent one, microcystin-LR (MC-LR, are of major concern and they have been reported to cause even death of mammals following ingestion or ingurgitation due to hepatotoxic modes of action. The aim of the recent study is to summarize briefly the impacts of microcystin on laboratory rodents, mice and rats, being used as models for other mammals including human beings. Most experimental approaches used intraperitoneal rather than oral and intratracheal application of microcystins, especially MC-LR, being the most efficient way to induce adverse impacts on different target organs. However, no matter how the exposure of rodents was performed, microcystins induced severe harmful impacts on the different target organs, preferentially the liver, for instances hemorrhages and apoptosis in liver, liver tumours, adverse effects on gut, kidney, testis and epididymis including spermatogenesis, on lung, on serum parameters and on progeny. In addition to these histological findings, microcystin was found to affect specifically biochemical parameters of target organs such as enzymes e.g. GST, CAT, GR, GPX, SOD, AST, ALT, γ-GT, protein phosphatases, SDH, SoDH and LDH or stress proteins such as HSP-70 and further parameters such as hepatic sulfhydryl content, GSH depletion, total bilirubin, urea nitrogen, and creatinine. Gene array analyses revealed that microcystin affects genes related to actin organization, cell cycle, apoptosis, cellular redox potential, cell signalling, albumin metabolism, glucose homeostasis pathway and organic anion transport polypeptide system. In combination with a further proteomics approach the proteomic analyses indicate that liver apoptosis induced by microcystin can be induced by two pathways: the

  17. Impact of a do-not-do intervention on 12 laboratory measurements.

    Science.gov (United States)

    Zambrana-García, J L; Macías Blanco, C; Fernández-Suárez, A; Peñacoba Masa, A; Olivares Durán, M J; Aguilar Benítez, J M; Zambrana-Luque, J L

    2017-08-19

    In recent years, various scientific societies and healthcare organisations have created recommendations aimed at decreasing the use of healthcare interventions that have shown no efficacy or effectiveness. The aim of this study was to assess the impact of an intervention on 12 do-not-do recommendations regarding the laboratory in 7 hospital centres. Before-after study conducted in 7 hospital centres of Cordoba and Jaen during 2015 and 2016. Based on the recommendations of existing scientific societies, a consensus was reached on various actions regarding laboratory measurements. We analysed the number and cost of measuring 6 tumour markers (carcinoembryonic antigen, prostate-specific antigen, carbohydrate antigen [CA] 15.3, CA125, CA19.9 and alpha-fetoprotein), thyrotropin, T3, T4, glycated haemoglobin, urea, ferritin and antigliadin antibodies, before and after implementing the consensus. Compared with the previous year, there were 55,902 fewer laboratory measurements (-19%) in 2016, with an overall savings of €82,100. The reduction in the number of measurements occurred mainly in plasma urea (-50.3%) and in the tumour markers CA125 (-16%), CA19.9 (-11.6%) and CA15.3 (-10.5%). The most pronounced savings were achieved in the measurements of urea (-€21,002), thyroid hormones (-€12,716) and thyrotropin (-€7,638). The adoption and consensus of do-not-do recommendations among healthcare levels resulted in a significant reduction in unnecessary measurements. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  18. THE IMPACT OF LABORATORY AIR TEMPERATURE AND RELATIVE HUMIDITY ON BENTONITE WATER ABSORPTION CAPACITY

    Directory of Open Access Journals (Sweden)

    Helena Strgar

    2011-12-01

    Full Text Available Bentonite, which is a mineral component of geosynthetic clay liners, has important physical and chemical properties that ensure very small hydraulic permeability. The main component of bentonite is a clay mineral called sodium montmorillonite whose very low permeability is due to its ability to swell. The deposits of bentonite are spread all over the world, however, only a very small number of those deposits satisfies all the quality and durability demands that must be met if the bentonite is to be used in the sealing barriers. Depending on the location of installation and their purpose, geosynthetic clay liners must meet certain requirements. Their compatibility with the prescribed criterion is confirmed through various laboratory procedures. Amongst them are tests examining the index indicators (free swell index, fluid loss index, and water absorption capacity. This paper presents results regarding the impact of laboratory air temperature and relative humidity of the testing area on the water absorption capacity. This is one of the criteria that bentonite must satisfy during the quality and durability control of the mineral component of geosynthetic clay liner (the paper is published in Croatian.

  19. Open-ended versus guided laboratory activities:Impact on students' beliefs about experimental physics

    Science.gov (United States)

    Wilcox, Bethany R.; Lewandowski, H. J.

    2016-12-01

    Improving students' understanding of the nature of experimental physics is often an explicit or implicit goal of undergraduate laboratory physics courses. However, lab activities in traditional lab courses are typically characterized by highly structured, guided labs that often do not require or encourage students to engage authentically in the process of experimental physics. Alternatively, open-ended laboratory activities can provide a more authentic learning environment by, for example, allowing students to exercise greater autonomy in what and how physical phenomena are investigated. Engaging in authentic practices may be a critical part of improving students' beliefs around the nature of experimental physics. Here, we investigate the impact of open-ended activities in undergraduate lab courses on students' epistemologies and expectations about the nature of experimental physics, as well as their confidence and affect, as measured by the Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS). Using a national data set of student responses to the E-CLASS, we find that the inclusion of some open-ended lab activities in a lab course correlates with more expertlike postinstruction responses relative to courses that include only traditional guided lab activities. This finding holds when examining postinstruction E-CLASS scores while controlling for the variance associated with preinstruction scores, course level, student major, and student gender.

  20. Moisture impact on building rocks - the laboratory and in situ investigations

    Science.gov (United States)

    Fidríková, M. Sc.; Kubičár, D. Sc.

    2012-04-01

    Rocks are influenced by moisture that in combination with temperature, hydrological conditions, climatic conditions, etc. leads to changes of physical and chemical properties. These changes can be observed in the laboratory, where different conditions can be simulated in which the rocks can be found. This work is focused on water transport and moisture determination in various sandstones observed in laboratory conditions and also directly in environment. Porosity affects transport properties of rocks. Experiments are focused on the mechanism distributing the water in sandstones with different porosities. Measurements were carried out by thermal conductivity sensors (Hot-ball sensor) which measure local temperature and local thermal conductivity. The sensor in connection with the RTM device is used for monitoring of the moisture in various sandstones with different porosity. For in situ measurements a moisture sensor is constructed. The sensor is made of the original stone in a form of the cylinder (diameter and length around 20 mm) in which thermal conductivity sensor is placed. The moisture sensor must be calibrated for dry and water saturated state, and then it is inserted into the original site to start monitoring of the impact of surrounding weather conditions on the rock. Meteorological data are correlated to the measured data. Results from water transport and change of moisture in sandstones at various monitoring conditions are presented.

  1. The acute effects of dynamic and ballistic stretching on vertical jump height, force, and power.

    Science.gov (United States)

    Jaggers, Jason R; Swank, Ann M; Frost, Karen L; Lee, Chong D

    2008-11-01

    Stretching before performance is a common practice among athletes in hopes of increasing performance and reducing the risk of injury. However, cumulative results indicate a negative impact of static stretching and proprioceptive neuromuscular facilitation (PNF) on performance; thus, there is a need for evaluating other stretching strategies for effective warm-up. The purpose of this study was to compare the differences between two sets of ballistic stretching and two sets of a dynamic stretching routine on vertical jump performance. Twenty healthy male and female college students between the ages of 22 and 34 (24.8 +/- 3 years) volunteered to participate in this study. All subjects completed three individual testing sessions on three nonconsecutive days. On each day, the subjects completed one of three treatments (no stretch, ballistic stretch, and dynamic stretch). Intraclass reliability was determined using the data obtained from each subject. A paired samples t-test revealed no significant difference in jump height, force, or power when comparing no stretch with ballistic stretch. A significant difference was found on jump power when comparing no stretch with dynamic stretch, but no significant difference was found for jump height or force. Statistics showed a very high reliability when measuring jump height, force, and power using the Kistler Quattro Jump force plate. It seems that neither dynamic stretching nor ballistic stretching will result in an increase in vertical jump height or force. However, dynamic stretching elicited gains in jump power poststretch.

  2. Modeling ballistic effects in frequency-dependent transient thermal transport using diffusion equations

    Science.gov (United States)

    Maassen, Jesse; Lundstrom, Mark

    2016-03-01

    Understanding ballistic phonon transport effects in transient thermoreflectance experiments and explaining the observed deviations from classical theory remains a challenge. Diffusion equations are simple and computationally efficient but are widely believed to break down when the characteristic length scale is similar or less than the phonon mean-free-path. Building on our prior work, we demonstrate how well-known diffusion equations, namely, the hyperbolic heat equation and the Cattaneo equation, can be used to model ballistic phonon effects in frequency-dependent periodic steady-state thermal transport. Our analytical solutions are found to compare excellently to rigorous numerical results of the phonon Boltzmann transport equation. The correct physical boundary conditions can be different from those traditionally used and are paramount for accurately capturing ballistic effects. To illustrate the technique, we consider a simple model problem using two different, commonly used heating conditions. We demonstrate how this framework can easily handle detailed material properties, by considering the case of bulk silicon using a full phonon dispersion and mean-free-path distribution. This physically transparent approach provides clear insights into the nonequilibrium physics of quasi-ballistic phonon transport and its impact on thermal transport properties.

  3. Characterization of blocks impacts from seismic signal: insights from laboratory experiments

    Science.gov (United States)

    Farin, M.; Mangeney, A.; Toussaint, R.; de Rosny, J.; Sainte-Marie, J.; Shapiro, N.

    2014-12-01

    Rockfalls, debris flows and rock avalanches represent a major natural hazard for the population in mountainous, volcanic and coastal areas but their direct observation on the field is very difficult. Recent field studies showed that gravitational instabilities can be detected, localized and characterized thanks to the seismic signal they generate. Therefore, a burning challenge for risks assessment related to these events is to obtain quantiative informations on the characteristics of the rockfalls (mass, speed, extension,...) from the properties of the signal (seismic energy, frequencies,...). Using a theoretical model of viscoelastic impact of a sphere on a plane, we develop analytical scaling laws relating the energy radiated in elastic waves, the energy dissipated in viscoelasticity during the impact and the frequencies of the generated acoustic signal to the mass m and the impact speed Vz of the sphere and to the elastic parameters of the involved materials. The elastic energy is shown to vary as m5/3Vz11/5 on plates and as mVz13/5 on blocks, regardless of the elastic parameters. The energy dissipated in viscoelasticity does not depend on the support thickness and varies as m2/3Vz11/5. The mean frequency of the generated signal is inversely proportional to the impact duration. Then, we conduct simple laboratory experiments that consist in dropping spherical beads of different size and materials and small gravels on thin plates of glass and Plexiglass and rock blocks. The elastic energy emitted by an impact on the supports is first quantitatively estimated and compared to the potential energy of fall and to the potential energy change during the shock. We observe a quantitative agreement between experimental data and the analytical scaling laws, even when we use small gravels instead of spherical beads as impactors. These experiments allows to valid the theoretical model and to establish the energy budget of an impact. In the experiments, piezoelectric

  4. Toward Better Personal Ballistic Protection

    Science.gov (United States)

    2014-03-04

    SINGLE WALL CARBON NANOTUBES (SWCNTs) The materials processes investigated were hot pressing (HP), hot isostatic pressing (HIP), cold isostatic ...attempt to optimize mechanical properties. The processing approaches investigated were pressureless sintering, hot pressing and hot isostatic ...fact, the high compressive strength and hardness of ceramic materials contribute to high resistance to the loading produced by a penetrator at impact

  5. Ballistic Missile Silo Door Monitoring Analysis

    Energy Technology Data Exchange (ETDEWEB)

    EDENBURN,MICHAEL W.; TROST,LAWRENCE C.

    2000-01-01

    This paper compares the cost and effectiveness of several potential options that may be used to monitor silo-based ballistic missiles. Silo door monitoring can be used to verify that warheads removed to deactivate or download silo-based ballistic missiles have not been replaced. A precedent for monitoring warhead replacement using reentry vehicle on site inspections (RV-OSIs) and using satellites has been established by START-I and START-II. However, other monitoring options have the potential to be less expensive and more effective. Three options are the most promising if high verification confidence is desired: random monitoring using door sensors; random monitoring using manned or unmanned aircraft; and continuous remote monitoring using unattended door sensors.

  6. Ballistic penetration of Perma-Gel

    Science.gov (United States)

    Ryckman, Raymond Albert; Powell, David Arthur; Lew, Adrian

    2012-03-01

    In this study a number of experiments were performed by taking high-speed footage of the firing spherical steel bullets at different speeds into Perma-Gel, a new synthetic thermoplastic material touted to exhibit similar properties to ordnance ballistic gelatin. We found that the gel undergoes very large and recoverable elastic deformations, which could strongly affect the dynamics of the temporary cavity formed behind the projectile. As with ordnance ballistic gelatin, the diameter of the temporary cavity can be many times the diameter of the projectile, in contrast with that of the permanent cavity which is several times smaller.We also observed that the closure of the cavity chokes the air inside, which could affect its dynamics in noticeable ways. Finally, one of the experiments suggest that the precise model of material failure may not be important to determine the dynamics of the temporary cavity.

  7. Ballistic model to estimate microsprinkler droplet distribution

    Directory of Open Access Journals (Sweden)

    Conceição Marco Antônio Fonseca

    2003-01-01

    Full Text Available Experimental determination of microsprinkler droplets is difficult and time-consuming. This determination, however, could be achieved using ballistic models. The present study aimed to compare simulated and measured values of microsprinkler droplet diameters. Experimental measurements were made using the flour method, and simulations using a ballistic model adopted by the SIRIAS computational software. Drop diameters quantified in the experiment varied between 0.30 mm and 1.30 mm, while the simulated between 0.28 mm and 1.06 mm. The greatest differences between simulated and measured values were registered at the highest radial distance from the emitter. The model presented a performance classified as excellent for simulating microsprinkler drop distribution.

  8. Attacking the Theater Mobile Ballistic Missile Threat

    Science.gov (United States)

    1993-06-01

    and Record, �Theater Ballistic Missile Defense and US Contingency Operations,� 13. 43Greg Myre, Associated Press, �De Klerk Reveals South African...possession). ____. Briefing, subject: �WarBreaker.� 17 December 1992. Myre, Greg. Associated Press. �De Klerk Reveals South African Nuclear...April�3 May 1992, 1,44. Ordway, Frederick I. III and Ronald C. Wakeford. International Missile and Spacecraft Guide. New York: McGraw

  9. Ballistic Missile Defense. Past and Future

    Science.gov (United States)

    2010-04-01

    and deployed. These are the two big questions of the anti-ballistic missile ( ABM ) debate. It must be emphasized that the...is the extreme polarization of the opposing positions that have been taken. Consider this statement: “The whole ABM question touched off so intense...earlier that same year by the Washington Post and ABC News11 reported that 80 percent of the American population was in favor of building a missile

  10. Prediction of the ballistic limit of an aluminium sandwich panel

    Science.gov (United States)

    Campbell, J.; De Vuyst, T.; Vignjevic, R.; Hughes, K.

    2016-08-01

    This paper presents research on modelling the impact of a 150g projectile on a 35mm thick aluminium sandwich panel. The objective of the work is a predictive modelling capability for the ballistic limit of the panel. A predictive modelling capability supports the design of capture and deorbit missions for large items of space debris such as satellites and rocket upper stages. A detailed explicit finite element model was built using the LSDYNA software and results were compared with experimental data for the projectile exit velocity to establish key parameters. The primary parameters influencing the model behaviour were the strength and failure of the aluminium face sheets and the friction between projectile and panel. The model results showed good agreement with experimental results for ogive nose projectiles, but overestimated the exit velocity for flat nose projectiles.

  11. Thermo-Electron Ballistic Coolers or Heaters

    Science.gov (United States)

    Choi, Sang H.

    2003-01-01

    Electronic heat-transfer devices of a proposed type would exploit some of the quantum-wire-like, pseudo-superconducting properties of single-wall carbon nanotubes or, optionally, room-temperature-superconducting polymers (RTSPs). The devices are denoted thermo-electron ballistic (TEB) coolers or heaters because one of the properties that they exploit is the totally or nearly ballistic (dissipation or scattering free) transport of electrons. This property is observed in RTSPs and carbon nanotubes that are free of material and geometric defects, except under conditions in which oscillatory electron motions become coupled with vibrations of the nanotubes. Another relevant property is the high number density of electrons passing through carbon nanotubes -- sufficient to sustain electron current densities as large as 100 MA/square cm. The combination of ballistic motion and large current density should make it possible for TEB devices to operate at low applied potentials while pumping heat at rates several orders of magnitude greater than those of thermoelectric devices. It may also enable them to operate with efficiency close to the Carnot limit. In addition, the proposed TEB devices are expected to operate over a wider temperature range

  12. Targeting Low-Energy Ballistic Lunar Transfers

    Science.gov (United States)

    Parker, Jeffrey S.

    2010-01-01

    Numerous low-energy ballistic transfers exist between the Earth and Moon that require less fuel than conventional transfers, but require three or more months of transfer time. An entirely ballistic lunar transfer departs the Earth from a particular declination at some time in order to arrive at the Moon at a given time along a desirable approach. Maneuvers may be added to the trajectory in order to adjust the Earth departure to meet mission requirements. In this paper, we characterize the (Delta)V cost required to adjust a low-energy ballistic lunar transfer such that a spacecraft may depart the Earth at a desirable declination, e.g., 28.5(white bullet), on a designated date. This study identifies the optimal locations to place one or two maneuvers along a transfer to minimize the (Delta)V cost of the transfer. One practical application of this study is to characterize the launch period for a mission that aims to launch from a particular launch site, such as Cape Canaveral, Florida, and arrive at a particular orbit at the Moon on a given date using a three-month low-energy transfer.

  13. Low-gravity Orbiting Research Laboratory Environment Potential Impact on Space Biology Research

    Science.gov (United States)

    Jules, Kenol

    2006-01-01

    One of the major objectives of any orbital space research platform is to provide a quiescent low gravity, preferably a zero gravity environment, to perform fundamental as well as applied research. However, small disturbances exist onboard any low earth orbital research platform. The impact of these disturbances must be taken into account by space research scientists during their research planning, design and data analysis in order to avoid confounding factors in their science results. The reduced gravity environment of an orbiting research platform in low earth orbit is a complex phenomenon. Many factors, among others, such as experiment operations, equipment operation, life support systems and crew activity (if it is a crewed platform), aerodynamic drag, gravity gradient, rotational effects as well as the vehicle structural resonance frequencies (structural modes) contribute to form the overall reduced gravity environment in which space research is performed. The contribution of these small disturbances or accelerations is precisely why the environment is NOT a zero gravity environment, but a reduced acceleration environment. This paper does not discuss other factors such as radiation, electromagnetic interference, thermal and pressure gradient changes, acoustic and CO2 build-up to name a few that affect the space research environment as well, but it focuses solely on the magnitude of the acceleration level found on orbiting research laboratory used by research scientists to conduct space research. For ease of analysis this paper divides the frequency spectrum relevant to most of the space research disciplines into three regimes: a) quasi-steady, b) vibratory and c) transient. The International Space Station is used as an example to illustrate the point. The paper discusses the impact of these three regimes on space biology research and results from space flown experiments are used to illustrate the potential negative impact of these disturbances (accelerations

  14. The economic impact of Sandia National Laboratories on central New Mexico and the state of New Mexico fiscal year 1997

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, R.R.; Nielsen, T.G.; Schultz, J. [New Mexico State Univ., Las Cruces, NM (United States); Adcock, L.D.; Gentry, L.M. [Dept. of Energy, Albuquerque, NM (United States). Albuquerque Operations Office; Ben-David, S. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Economics; Temple, J. [Temple (John), Albuquerque, NM (United States)

    1998-05-29

    Sandia National Laboratories (SNL) was established in 1949 to perform the engineering development and ordnance responsibilities associated with nuclear weapons. By the early 1960`s the facility had evolved into an engineering research and development laboratory and became a multiprogram laboratory during the 1970s. Sandia is operated for the US Department of Energy by the Sandia Corporation, a wholly-owned subsidiary of Lockheed Martin, Incorporated. For several years, the US Department of Energy (DOE) Albuquerque Operations Office (AL) and New Mexico State University (NMSU) have maintained an inter-industry, input-output model with capabilities to assess the impacts of developments initiated outside the economy such as federal DOE monies that flow into the state, on an economy. This model will be used to assess economic, personal income and employment impacts of SNL on central New Mexico and the state of New Mexico. For this report, the reference period is FY 1997 (October 1, 1996, through September 30, 1997) and includes two major impact analyses: the impact of SNL activities on central New Mexico and the economic impacts of SNL on the state of New Mexico. For purposes of this report, the central New Mexico region includes Bernalillo, Sandoval, Valencia, and Torrance counties. Total impact represents both direct and indirect respending by business, including induced effects (respending by households). The standard multipliers used in determining impacts results from the inter-industry, input-output models developed for the four-county region and the state of New Mexico. 6 figs., 10 tabs.

  15. The impact of gross anatomy laboratory on first year medical students' interest in a surgical career.

    Science.gov (United States)

    Pulcrano, Marisa E; Malekzadeh, Sonya; Kumar, Anagha

    2016-09-01

    This study sought to determine the impact of gross anatomy laboratory (GA) on first year medical students' (M1) interest in a surgical career. Secondary objectives included identifying other influences in M1s' career decision making. This prospective study included surveys before and after GA. All M1s enrolled in GA were invited to participate. Sixty students completed both the pre- and post-test surveys. A 5-point Likert-type scale surveyed participants' interests, specific personality traits, experience during the course of GA, and likelihood of pursuing a surgical career. Statistical analysis included Wilcoxon Signed Rank Test and (Polychotomous) Ordinal Logistic Regression Model. Students' desire to work with their hands increased (50 vs. 33.3%) and enjoyment working with instruments and tools similarly increased (50 vs. 41.7%). Likelihood of pursuing a surgical career after gross anatomy increased in 31.7% of students, decreased in 16.7%, and was unchanged in 51.7%. Over 75% of students with a prior interest in surgery and 21% of those who previously felt neutral agreed that they were likely to pursue a career in surgery at the conclusion of the laboratory. Students with a surgeon family member were 0.1976 times as likely to exhibit a positive change in interest (P values 0.024). Gross anatomy may influence up to a third of the class to consider a surgical career, especially those with a prior interest in surgery and those previously feeling ambivalent. Students with a surgeon family member became less likely to enter a surgical career after gross anatomy. Clin. Anat. 29:691-695, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. Impact of Fast Charging on Life of EV Batteries; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Neubauer, Jeremy; Wood, Eric; Burton, Evan; Smith, Kandler; Pesaran, Ahmad

    2015-05-03

    Installation of fast charging infrastructure is considered by many as one of potential solutions to increase the utility and range of electric vehicles (EVs). This is expected to reduce the range anxiety of drivers of EVs and thus increase their market penetration. Level 1 and 2 charging in homes and workplaces is expected to contribute to the majority of miles driven by EVs. However, a small percentage of urban driving and most of inter-city driving could be only achieved by a fast-charging network. DC fast charging at 50 kW, 100 kW, 120 kW compared to level 1 (3.3 kW) and level 2 (6.6 kW) results in high-current charging that can adversely impact the life of the battery. In the last couple of years, we have investigated the impact of higher current rates in batteries and potential of higher temperatures and thus lower service life. Using mathematical models, we investigated the temperature increase of batteries due to higher heat generation during fast charge and have found that this could lead to higher temperatures. We compared our models with data from other national laboratories both for fine-tuning and calibration. We found that the incremental temperature rise of batteries during 1C to 3C fast charging may reduce the practical life of the batteries by less than 10% over 10 to 15 years of vehicle ownership. We also found that thermal management of batteries is needed for fast charging to prevent high temperature excursions leading to unsafe conditions.

  17. Background music in the dissection laboratory: impact on stress associated with the dissection experience.

    Science.gov (United States)

    Anyanwu, Emeka G

    2015-06-01

    Notable challenges, such as mental distress, boredom, negative moods, and attitudes, have been associated with learning in the cadaver dissection laboratory (CDL). The ability of background music (BM) to enhance the cognitive abilities of students is well documented. The present study was designed to investigate the impact of BM in the CDL and on stress associated with the dissection experience. After 8 wk of normal dissection without BM, various genres of BM were introduced into the cadaver dissection sessions of 260 medical and dental students for 3 wk. Feedback on the impact of BM on students in the CDL and students' attitude were accessed using a questionnaire. Psychological stress assessment was done using Psychological Stress Measure 9. Two batches of 30 students each were made to dissect same areas of the body for 2 h, one batch with BM playing and the other batch without. The same examination was given to both groups at the end. Over 90% of the participants expressed a desire to incorporate BM into the CDL; 87% of the sampled population that expressed love for music also reported BM to be a very useful tool that could be used to enhance learning conditions in the CDL. A strong positive relationship was established between love for music and its perception as a tool for learning in the CDL (P < 0.001). Students that studied under the influence of BM had significantly higher scores (P < 0.001) in the overall examination result. BM reduced the level of stress associated with the dissection experience by ∼33%. Copyright © 2015 The American Physiological Society.

  18. Survival of Organic Materials in Hypervelocity Impacts of Ice on Sand, Ice, and Water in the Laboratory

    Science.gov (United States)

    Bowden, Stephen A.; Cole, Michael; Parnell, John

    2014-01-01

    Abstract The survival of organic molecules in shock impact events has been investigated in the laboratory. A frozen mixture of anthracene and stearic acid, solvated in dimethylsulfoxide (DMSO), was fired in a two-stage light gas gun at speeds of ∼2 and ∼4 km s−1 at targets that included water ice, water, and sand. This involved shock pressures in the range of 2–12 GPa. It was found that the projectile materials were present in elevated quantities in the targets after impact and in some cases in the crater ejecta as well. For DMSO impacting water at 1.9 km s−1 and 45° incidence, we quantify the surviving fraction after impact as 0.44±0.05. This demonstrates successful transfer of organic compounds from projectile to target in high-speed impacts. The range of impact speeds used covers that involved in impacts of terrestrial meteorites on the Moon, as well as impacts in the outer Solar System on icy bodies such as Pluto. The results provide laboratory evidence that suggests that exogenous delivery of complex organic molecules from icy impactors is a viable source of such material on target bodies. Key Words: Organic—Hypervelocity—Shock—Biomarkers. Astrobiology 14, 473–485. PMID:24901745

  19. Strain Rate Effect on the Tensile Behavior of Fibers and Its Application to Ballistic Perforation of Multi-layered Fabrics

    Institute of Scientific and Technical Information of China (English)

    GU Bo-hong; PAN Xiong-qi

    2002-01-01

    Rate-dependent property of material is very important in analysis of ballistic impact. The tensile property of Twaron(R) filaments at strain rate range from 0.01/s to1 000/s was obtained by MTS materials testing and split Hopkinson tension bar. Rate sensitivity of Twaron(R) filaments is discussed. Application of high strain rate property to ballistic perforation of multi- layered fabrics conforms to the actual situation than that of quasi-static property. The revised analytical model can be used to calculate the process of ballistic penetration and perforation on soft armour, such as fabric target plate,at intuitive approach and simple algorithm with a little computer process time. Predictions of the residual velocities and energy absorbed by the multi- layered fabric show good agreement with experimental data.

  20. Acoustics. Measurement of sound insulation in buildings and of building elements. Laboratory measurements of the reduction of transmitted impact noise by floor coverings on a heavyweight standard floor

    CERN Document Server

    British Standards Institution. London

    1998-01-01

    Acoustics. Measurement of sound insulation in buildings and of building elements. Laboratory measurements of the reduction of transmitted impact noise by floor coverings on a heavyweight standard floor

  1. The Impact of Physics Laboratory on Students Offering Physics in Ethiope West Local Government Area of Delta State

    Science.gov (United States)

    Godwin, Oluwasegun; Adrian, Ohwofosirai; Johnbull, Emagbetere

    2015-01-01

    The impact of Physics laboratory on students was carried out among senior secondary school students offering Physics in Ethiope West Local Government Area of Delta State using descriptive survey. Five public schools were random-even samplying technique was adopted for precision. Fifty questionnaires were distributed to students in each school,…

  2. The Impact of Physics Laboratory on Students Offering Physics in Ethiope West Local Government Area of Delta State

    Science.gov (United States)

    Godwin, Oluwasegun; Adrian, Ohwofosirai; Johnbull, Emagbetere

    2015-01-01

    The impact of Physics laboratory on students was carried out among senior secondary school students offering Physics in Ethiope West Local Government Area of Delta State using descriptive survey. Five public schools were random-even samplying technique was adopted for precision. Fifty questionnaires were distributed to students in each school,…

  3. A laboratory comparison of the global warming impact of five major types of biomass cooking stoves

    Energy Technology Data Exchange (ETDEWEB)

    MacCarty, N.; Ogle, D.; Still, D.; Bond, T.; Roden, C. [Aprovecho Research Center, Creswell, OR (United States)

    2008-06-15

    With over 2 billion of the world's population living in families using biomass to cook every day, the possibility of improved stoves helping to mitigate climate change is generating increasing attention. With their emissions of carbon dioxide (CO{sub 2}), methane, and black carbon, among other substances, is there a cleaner, practical option to provide to the families that will need to continue to use biomass for cooking? This study served to help quantify the relative emissions from five common types of biomass combustion in order to investigate if there are cleaner options. The laboratory results showed that for situations of sustainable harvesting where CO{sub 2} emissions are considered neutral, some improved stoves with rocket-type combustion or fan assistance can reduce overall warming impact from the products of incomplete combustion (PICs) by as much as 50-95%. In non-sustainable situations where fuel and CO{sub 2} savings are of greater importance, three types of improved combustion methods were shown to potentially reduce warming by 40-60%. Charcoal-burning may emit less CO{sub 2} than traditional wood-burning, but the PIC emissions are significantly greater.

  4. Rotavirus infection in a tertiary hospital: laboratory diagnosis and impact of immunization on pediatric hospitalization

    Directory of Open Access Journals (Sweden)

    Luciane Aparecida Pereira

    2011-06-01

    Full Text Available BACKGROUND AND OBJECTIVES: Rotavirus (RV is the main etiological agent of diarrhea in childhood; its laboratory diagnosis is crucial to guide the clinical management and prevention of its spread. RV immunization was introduced in Brazilian 6-month-old children in 2006. The present study was aimed to evaluate three methodologies used for human RV detection in stool samples obtained from patients hospitalized due to gastroenteritis in a teaching hospital and report the impact of RV immunization in hospitalization by diarrhea. METHODS: 293 stool samples collected in the 2001-2008 period were analyzed by enzyme immunoassay (EIA, latex agglutination (LA and polyacrylamide gel electrophoresis (PAGE. RESULTS: Rotavirus was detected in 34.8% of samples by LA assay, 28.3% of samples by EIA assay and in 25.6% of samples by PAGE assay. Considering the PAGE method as gold standard, the sensitivity, specificity and accuracy of EIA were 94.6%, 94.4% and 94.5%, and to LA were 82.6%, 81.6% and 81.9%, respectively. CONCLUSION: These results indicate that antigen detection by EIA is a rapid, sensitive and specific method, and could be used in large-scale applications for screening stool samples suspected of RV infection. This study showed decreased incidence of RV infection in hospitalized children prior to the implementation of the national immunization program against RV.

  5. Rotavirus infection in a tertiary hospital: laboratory diagnosis and impact of immunization on pediatric hospitalization

    Directory of Open Access Journals (Sweden)

    Luciane Aparecida Pereira

    Full Text Available BACKGROUND AND OBJECTIVES: Rotavirus (RV is the main etiological agent of diarrhea in childhood; its laboratory diagnosis is crucial to guide the clinical management and prevention of its spread. RV immunization was introduced in Brazilian 6-month-old children in 2006. The present study was aimed to evaluate three methodologies used for human RV detection in stool samples obtained from patients hospitalized due to gastroenteritis in a teaching hospital and report the impact of RV immunization in hospitalization by diarrhea. METHODS: 293 stool samples collected in the 2001-2008 period were analyzed by enzyme immunoassay (EIA, latex agglutination (LA and polyacrylamide gel electrophoresis (PAGE. RESULTS: Rotavirus was detected in 34.8% of samples by LA assay, 28.3% of samples by EIA assay and in 25.6% of samples by PAGE assay. Considering the PAGE method as gold standard, the sensitivity, specificity and accuracy of EIA were 94.6%, 94.4% and 94.5%, and to LA were 82.6%, 81.6% and 81.9%, respectively. CONCLUSION: These results indicate that antigen detection by EIA is a rapid, sensitive and specific method, and could be used in large-scale applications for screening stool samples suspected of RV infection. This study showed decreased incidence of RV infection in hospitalized children prior to the implementation of the national immunization program against RV.

  6. Laboratory evaluation of the impact of the addition of resid in FCC

    Energy Technology Data Exchange (ETDEWEB)

    Devard, Alejandra; de la Puente, Gabriela; Sedran, Ulises [Instituto de Investigaciones en Catalisis y Petroquimica (INCAPE, FIQ, UNL-CONICET), Santiago del Estero 2654 (3000) Santa Fe (Argentina)

    2009-01-15

    The conversion and product distributions from a mixture of 10% atmospheric tower bottom resid and a DO hydrocarbon cut similar to LCO that represented commercial feedstocks were assessed over two equilibrium commercial FCC catalysts in a laboratory CREC Riser Simulator reactor. The reaction temperature was 550 C, the catalyst to oil ratio was 5.8 and the reaction times were up to 25 s. The conversion of the mixture as compared to the DO base feed was higher in the case of the most active, conventional catalyst, and remained very similar on the resid catalyst. Since the yields of the main hydrocarbon groups dry gas, LPG, gasoline and coke followed very similar trends when the two pure feedstocks were converted, the corresponding yields from the mixture also obeyed that behaviour, and were the consequence of the conversion reached. The impact of the different catalyst formulations was observed in, for example, the selectively different yields obtained from the conversion of the resid, and in the composition of the gasoline. Independently of the catalyst, the gasoline was more olefinic and less aromatic when the resid was present. It was shown that in order to evaluate properly a given combination of feeds, catalysts and conditions, they must be considered together. (author)

  7. Degradation of chlorpyrifos in laboratory soil and its impact on soil microbial functional diversity

    Institute of Scientific and Technical Information of China (English)

    FANG Hua; YU Yunlong; CHU Xiaoqiang; WANG Xiuguo; YANG Xiaoe; YU Jingquan

    2009-01-01

    Degradation of chlorpyrifos at different concentrations in soil and its impact on soil microbial functional diversity were investigated under laboratory conditions. The degradation half-lives of chlorpyrifos at levels of 4, 8, and 12 mg/kg in soil were calculated to be 14.3, 16.7, and 18.0 d, respectively. The Biolog study showed that average well color development (AWCD) in soils was significantly (P < 0.05) inhibited by chlorpyrifos within the first two weeks and thereafter recovered to the similar level as the control. A similar variation in the diversity indices (Simpson index 1/D and McIntosh index U) in chlorpyrifos-treated soils was observed, no significant difference in the Shannon-Wiener index H' was found in these soils. With increasing chlorpyrifos concentration, the half-lives of chlorpyrifos were significantly (P ≤ 0.05) extended and its inhibitory effects on soil microorganisms were aggravated. It is concluded that chlorpyrifos residues in soil had a temporary or short-term inhibitory effect on soil microbial functional diversity.

  8. The reference ballistic imaging database revisited.

    Science.gov (United States)

    De Ceuster, Jan; Dujardin, Sylvain

    2015-03-01

    A reference ballistic image database (RBID) contains images of cartridge cases fired in firearms that are in circulation: a ballistic fingerprint database. The performance of an RBID was investigated a decade ago by De Kinder et al. using IBIS(®) Heritage™ technology. The results of that study were published in this journal, issue 214. Since then, technologies have evolved quite significantly and novel apparatus have become available on the market. The current research article investigates the efficiency of another automated ballistic imaging system, Evofinder(®) using the same database as used by De Kinder et al. The results demonstrate a significant increase in correlation efficiency: 38% of all matches were on first position of the Evofinder correlation list in comparison to IBIS(®) Heritage™ where only 19% were on the first position. Average correlation times are comparable to the IBIS(®) Heritage™ system. While Evofinder(®) demonstrates specific improvement for mutually correlating different ammunition brands, ammunition dependence of the markings is still strongly influencing the correlation result because the markings may vary considerably. As a consequence a great deal of potential hits (36%) was still far down in the correlation lists (positions 31 and lower). The large database was used to examine the probability of finding a match as a function of correlation list verification. As an example, the RBID study on Evofinder(®) demonstrates that to find at least 90% of all potential matches, at least 43% of the items in the database need to be compared on screen and this for breech face markings and firing pin impression separately. These results, although a clear improvement to the original RBID study, indicate that the implementation of such a database should still not be considered nowadays.

  9. Development and testing of a flexible ballistic neck protection

    NARCIS (Netherlands)

    Roebroeks, G.H.J.J.; Rensink, P.

    2016-01-01

    Sufficient ballistic protection of the neck area would significantly reduce the vulnerability of an infantry soldier. So far this protection is offered by extensions on the ballistic vest or combat helmet. However, the requirements for head agility and the various body to head positions combined wit

  10. Ballistic Characterization of the Scalability of Magnesium Alloy AMX602

    Science.gov (United States)

    2015-07-01

    Magnesium Alloy AMX602 by Tyrone L Jones Weapons and Materials Research Directorate, ARL Katsuyoshi Kondoh Joining and Welding Research...formed a collaborative partnership with Osaka University Joining and Welding Research Institute (JWRI), Taber Extrusions, Epson Atmix, Pacific Sowa...Powder Metallurgy 4 5. Fabrication Procedure 4 6. Mechanical Property Analysis 5 7. Ballistic Experimental Procedures 6 8. Ballistic Experimental

  11. An integrated approach towards future ballistic neck protection materials selection.

    Science.gov (United States)

    Breeze, John; Helliker, Mark; Carr, Debra J

    2013-05-01

    Ballistic protection for the neck has historically taken the form of collars attached to the ballistic vest (removable or fixed), but other approaches, including the development of prototypes incorporating ballistic material into the collar of an under body armour shirt, are now being investigated. Current neck collars incorporate the same ballistic protective fabrics as the soft armour of the remaining vest, reflecting how ballistic protective performance alone has historically been perceived as the most important property for neck protection. However, the neck has fundamental differences from the thorax in terms of anatomical vulnerability, flexibility and equipment integration, necessitating a separate solution from the thorax in terms of optimal materials selection. An integrated approach towards the selection of the most appropriate combination of materials to be used for each of the two potential designs of future neck protection has been developed. This approach requires evaluation of the properties of each potential material in addition to ballistic performance alone, including flexibility, mass, wear resistance and thermal burden. The aim of this article is to provide readers with an overview of this integrated approach towards ballistic materials selection and an update of its current progress in the development of future ballistic neck protection.

  12. Ballistic performance and microstructure of four armor ceramics

    NARCIS (Netherlands)

    Abadjieva, E.; Carton, E.P.

    2013-01-01

    The ballistic behavior of four different armor ceramic materials with thicknesses varying from 3 mm to 14 mm has been investigated. These are two types of alumina Al2O3 armor grades and two types of SiC armor grades produced by different armor ceramic producers. The ballistic study has been performe

  13. Development and testing of a flexible ballistic neck protection

    NARCIS (Netherlands)

    Roebroeks, G.H.J.J.; Rensink, P.

    2016-01-01

    Sufficient ballistic protection of the neck area would significantly reduce the vulnerability of an infantry soldier. So far this protection is offered by extensions on the ballistic vest or combat helmet. However, the requirements for head agility and the various body to head positions combined

  14. Ballistic performance and microstructure of four armor ceramics

    NARCIS (Netherlands)

    Abadjieva, E.; Carton, E.P.

    2013-01-01

    The ballistic behavior of four different armor ceramic materials with thicknesses varying from 3 mm to 14 mm has been investigated. These are two types of alumina Al2O3 armor grades and two types of SiC armor grades produced by different armor ceramic producers. The ballistic study has been

  15. MD Test of a Ballistic Optics

    CERN Document Server

    Garcia-Tabares Valdivieso, Ana; Salvachua Ferrando, Belen Maria; Skowronski, Piotr Krzysztof; Solfaroli Camillocci, Matteo; Tomas Garcia, Rogelio; Wenninger, Jorg; Coello De Portugal - Martinez Vazquez, Jaime Maria; CERN. Geneva. ATS Department

    2016-01-01

    The ballistic optics is designed to improve the understanding of optical errors and BPM systematic effects in the critical triplet region. The particularity of that optics is that the triplet is switched off, effectively transforming the triplets on both sides of IR1 and IR5 into drift spaces. Advantage can be taken from that fact to localize better errors in the Q4-Q5-triplet region. During this MD this new optics was tested for the first time at injection with beam 2.

  16. Hollow ballistic pendulum for plasma momentum measurements

    Science.gov (United States)

    Goncharov, S. F.; Pashinin, P. P.; Perov, V. Y.; Serov, R. V.; Yanovsky, V. P.

    1988-05-01

    A novel pendulum design—hollow ballistic pendulum—is suggested for plasma momentum measurements. It has an advantage over the pendula used earlier in laser plasma experiments of being insensitive to a momentum of matter evaporated and scattered by the pendulum wall exposed to the plasma, which usually exceeds plasma momentum to be measured. Simple expressions describing pendulum performance are derived, and requirements of shape and size are established. Using this kind of pendulum in experiments on laser acceleration of thin foils made it possible to measure the momentum of accelerated foil with an accuracy of about 10%.

  17. More Inaccurate Specifications of Ballistic Coefficients

    Science.gov (United States)

    2012-01-02

    The rifles used in the study were all Remington 700s with factory barrels. The 223 Remington , 308 Winchester, and 30-06 were all ADLs with...Berger 62 grain flat base varmint bullet. This bullet demonstrates excellent accuracy (0.5 MOA) in the Remington 700 test rifle out to 300 yards and...factor. The earlier paper (Courtney and Courtney 2009) reported a BC of 0.308 +/- 0.010 for the 125 grain Nosler Ballistic Tip from the Remington

  18. Going ballistic: Graphene hot electron transistors

    Science.gov (United States)

    Vaziri, S.; Smith, A. D.; Östling, M.; Lupina, G.; Dabrowski, J.; Lippert, G.; Mehr, W.; Driussi, F.; Venica, S.; Di Lecce, V.; Gnudi, A.; König, M.; Ruhl, G.; Belete, M.; Lemme, M. C.

    2015-12-01

    This paper reviews the experimental and theoretical state of the art in ballistic hot electron transistors that utilize two-dimensional base contacts made from graphene, i.e. graphene base transistors (GBTs). Early performance predictions that indicated potential for THz operation still hold true today, even with improved models that take non-idealities into account. Experimental results clearly demonstrate the basic functionality, with on/off current switching over several orders of magnitude, but further developments are required to exploit the full potential of the GBT device family. In particular, interfaces between graphene and semiconductors or dielectrics are far from perfect and thus limit experimental device integrity, reliability and performance.

  19. Dynamic conductance of a ballistic quantum wire

    Energy Technology Data Exchange (ETDEWEB)

    Quan Jun [School of Physics Science and Technology, Zhanjiang Normal University, Zhanjiang 524048 (China); Tian Ying [Center of Liberal Education, Zhanjiang Normal University, Zhanjiang 524048 (China); Zhang, Jun, E-mail: ntu_submit@yahoo.c [School of Physics Science and Technology, Zhanjiang Normal University, Zhanjiang 524048 (China); Shenzhen Institute of Advanced Integration Technology, Shenzhen 518055 (China); Shao Lexi [School of Physics Science and Technology, Zhanjiang Normal University, Zhanjiang 524048 (China)

    2011-04-01

    Within the framework of exact linear response theory, we derive a general formula, with which the dynamic conductance of mesoscopic system can be determined in the absence of Coulomb interaction. In addition, we present a solution to the problem of current partition in the system. These allow the derivation of dynamic conductance in time-dependent case. As a natural consequence, the current (charge) conservation and gauge invariance conditions are fulfilled. To give an example, we discuss the dynamic conductance of a ballistic quantum wire, and the effect of contacts on the conductance is also discussed.

  20. The impact of insecticides to local honey bee colony Apis cerana indica in laboratory condition

    Science.gov (United States)

    Putra, Ramadhani E.; Permana, Agus D.; Nuriyah, Syayidah

    2014-03-01

    Heavy use of insecticides considered as one of common practice at local farming systems. Even though many Indonesian researchers had stated the possible detrimental effect of insecticide on agriculture environment and biodiversity, researches on this subject had been neglected. Therefore, our purpose in this research is observing the impact of insecticides usage by farmer to non target organisme like local honey bee (Apis cerana indica), which commonly kept in area near agriculture system. This research consisted of field observations out at Ciburial, Dago Pakar, Bandung and laboratory tests at School of Life Sciences and Technology, Institut Teknologi Bandung. The field observations recorded visited agriculture corps and types of pollen carried by bees to the nest while laboratory test recorderd the effect of common insecticide to mortality and behavior of honey bees. Three types of insecticides used in this research were insecticides A with active agent Chlorantraniliprol 50 g/l, insecticide B with active agent Profenofos 500 g/l, and insecticides C with active agent Chlorantraniliprol 100 g/l and λ-cyhalotrin 50g/l. The results show that during one week visit, wild flower, Wedelia montana, visited by most honey bees with average visit 60 honey bees followed by corn, Zea mays, with 21 honey bees. The most pollen carried by foragers was Wedelia montana, Calliandra callothyrsus, and Zea mays. Preference test show that honeybees tend move to flowers without insecticides as the preference to insecticides A was 12.5%, insecticides B was 0%, and insecticides was C 4.2%. Mortality test showed that insecticides A has LD50 value 0.01 μg/μl, insecticide B 0.31 μg/μl, and insecticides C 0.09 μg/μl which much lower than suggested dosage recommended by insecticides producer. This research conclude that the use of insecticide could lower the pollination service provide by honey bee due to low visitation rate to flowers and mortality of foraging bees.

  1. Feasibility of ballistic strengthening exercises in neurologic rehabilitation.

    Science.gov (United States)

    Williams, Gavin; Clark, Ross A; Hansson, Jessica; Paterson, Kade

    2014-09-01

    Conventional methods for strength training in neurologic rehabilitation are not task specific for walking. Ballistic strength training was developed to improve the functional transfer of strength training; however, no research has investigated this in neurologic populations. The aim of this pilot study was to evaluate the feasibility of applying ballistic principles to conventional leg strengthening exercises in individuals with mobility limitations as a result of neurologic injuries. Eleven individuals with neurologic injuries completed seated and reclined leg press using conventional and ballistic techniques. A 2 × 2 repeated-measures analysis of variance was used to compare power measures (peak movement height and peak velocity) between exercises and conditions. Peak jump velocity and peak jump height were greater when using the ballistic jump technique rather than the conventional concentric technique (P exercises, the incorporation of ballistic principles was associated with increased peak height and peak velocities.

  2. Ballistic Behaviour of Tempered Steel Armour Plates under Plane Strain Condition .

    Directory of Open Access Journals (Sweden)

    S. N. Dikshit

    1998-04-01

    Full Text Available The present investigation deals with the ballistic behaviour of tempered steel armour plates under plane strain condition at normal angle of attack. A conical-shaped steel projectile of 6.1 mmdiameter was impacted on 20 mm thick steel annour plates of 350, 450 and 550 Hv hardness, in the velocity range 200 -700 m/s at zero obliquity. Ballistic performance measured in terms of the depthof penetration indicates that, under plane strain condition, behavio1Do" f 550 Hv steel plate is better than those of the other two plates. However, front spalling causes damageto the entry side of the high hardness plate, thus affecting its multihit capability in a limited manner.

  3. Ballistic performance of a Kevlar-29 woven fibre composite under varied temperatures

    Science.gov (United States)

    Soykasap, O.; Colakoglu, M.

    2010-05-01

    Armours are usually manufactured from polymer matrix composites and used for both military and non-military purposes in different seasons, climates, and regions. The mechanical properties of the composites depend on temperature, which also affects their ballistic characteristics. The armour is used to absorb the kinetic energy of a projectile without any major injury to a person. Therefore, besides a high strength and lightness, a high damping capacity is required to absorb the impact energy transferred by the projectile. The ballistic properties of a Kevlar 29/polyvinyl butyral composite are investigated under varied temperatures in this study. The elastic modulus of the composite is determined from the natural frequency of composite specimens at different temperatures by using a damping monitoring method. Then, the backside deformation of composite plates is analysed experimentally and numerically employing the finite-element program Abaqus. The experimental and numeric results obtained are in good agreement.

  4. Ballistic resistant article, semi-finished product for and method of making a shell for a ballistic resistant article

    NARCIS (Netherlands)

    Harings, Jules; Janse, Gerardus

    2013-01-01

    The invention relates to a ballistic resistant article, such as a helmet (1), comprising a double curved shell (2) in turn comprising a stack (5) of layers (6) of an oriented anti-ballistic material, the layers (6) comprising one or more plies and having a plurality of cuts (7), the ends of which

  5. Impact of lean six sigma process improvement methodology on cardiac catheterization laboratory efficiency.

    Science.gov (United States)

    Agarwal, Shikhar; Gallo, Justin J; Parashar, Akhil; Agarwal, Kanika K; Ellis, Stephen G; Khot, Umesh N; Spooner, Robin; Murat Tuzcu, Emin; Kapadia, Samir R

    2016-03-01

    Operational inefficiencies are ubiquitous in several healthcare processes. To improve the operational efficiency of our catheterization laboratory (Cath Lab), we implemented a lean six sigma process improvement initiative, starting in June 2010. We aimed to study the impact of lean six sigma implementation on improving the efficiency and the patient throughput in our Cath Lab. All elective and urgent cardiac catheterization procedures including diagnostic coronary angiography, percutaneous coronary interventions, structural interventions and peripheral interventions performed between June 2009 and December 2012 were included in the study. Performance metrics utilized for analysis included turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start and manual sheath-pulls inside the Cath Lab. After implementation of lean six sigma in the Cath Lab, we observed a significant improvement in turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab. The percentage of cases with optimal turn-time increased from 43.6% in 2009 to 56.6% in 2012 (p-trendsix sigma, on improving and sustaining efficiency of our Cath Lab operation. After the successful implementation of this continuous quality improvement initiative, there was a significant improvement in the selected performance metrics namely turn-time, physician downtime, on-time patient arrival, on-time physician arrival, on-time start as well as sheath-pulls inside the Cath Lab. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Impulse-variability theory: implications for ballistic, multijoint motor skill performance.

    Science.gov (United States)

    Urbin, M A; Stodden, David F; Fischman, Mark G; Weimar, Wendi H

    2011-01-01

    Impulse-variability theory (R. A. Schmidt, H. N. Zelaznik, B. Hawkins, J. S. Frank, & J. T. Quinn, 1979) accounts for the curvilinear relationship between the magnitude and resulting variability of the muscular forces that influence the success of goal-directed limb movements. The historical roots of impulse-variability theory are reviewed in the 1st part of this article, including the relationship between movement speed and spatial error. The authors then address the relevance of impulse-variability theory for the control of ballistic, multijoint skills, such as throwing, striking, and kicking. These types of skills provide a stark contrast to the relatively simple, minimal degrees of freedom movements that characterized early research. However, the inherent demand for ballistic force generation is a strong parallel between these simple laboratory tasks and multijoint motor skills. Therefore, the authors conclude by recommending experimental procedures for evaluating the adequacy of impulse variability as a theoretical model within the context of ballistic, multijoint motor skill performance.

  7. Field mapping of ballistic pressure pulse sources

    Directory of Open Access Journals (Sweden)

    Rad Abtin Jamshidi

    2015-09-01

    Full Text Available Ballistic pressure pulse sources are used since late 1990s for the extracorporeal treatment of chronic Enthesitis. Newly indications are found in trigger-point-therapy for the treatment of musculoskeletal disorders. In both applications excellent results without relevant side effects were found in clinical trials. The technical principle of pressure pulse source is based on the same techniques used in air guns. A projectile is accelerated by pressurized air and hits the applicator with high kinetic energy. By this a compression wave travels through the material and induces a fast (4..5μs, almost singular pressure pulse of 2..10 MPa, which is followed by an equally short rarefaction phase of about the same amplitude. It is assumed that the pressure pulse accounts for the biomedical effects of the device. The slower inertial motion of the waveguide is damped by elastic stoppers, but still can be measured several micro seconds after the initial pressure pulse. In order to characterize the pressure pulse devices, field mapping is performed on several radial pressure pulse sources using the fiber optic hydrophone and a polyvinylidenfluorid (PVDF piezoelectric hydrophone. It could be shown that the current standard (IEC 61846 is not appropriate for characterization of ballistic pressure pulse sources.

  8. Short report of an unusual ballistic trauma

    Science.gov (United States)

    Inchingolo, Francesco; Tatullo, Marco; Marrelli, Massimo; Inchingolo, Alessio D.; Pinto, Giorgia; Inchingolo, Angelo M.; Dipalma, Gianna

    2011-01-01

    INTRODUCTION Portable firearms have a relevant medico-legal interest, being a major cause of injury. Bullet entry wounds generally have a particular appearance, including contusion, skin introflection, and simple or excoriated ecchymosis. The skin wound is typically a hole with frayed margins, whose diameter is smaller than that of the bullet. PRESENTATION OF CASE We report the case of a 19-year-old man with ballistic trauma. Examination of the patient's lesions indicated that the bullet had entered from the left mandibular parasymphysis, creating a small hole without the typical bullet wipe and blackening. Subsequently, the bullet seemed to have fractured the left chin region immediately below the lower alveolar process, and it finally stopped in the submandibular area in the suprahyoid region of the neck. DISCUSSION This case is peculiar because the distinctive features of a firearm injury were absent; the lack of bleeding and edema made the case difficult to interpret without additional diagnostic investigations. CONCLUSION Ballistic trauma can manifest in different ways; therefore, internal trauma should be suspected even in the absence of clear external signs. This case report shows how an unusual bullet entry hole can mask quite serious injuries. PMID:22096751

  9. Advanced geometries for ballistic neutron guides

    Science.gov (United States)

    Schanzer, Christian; Böni, Peter; Filges, Uwe; Hils, Thomas

    2004-08-01

    Sophisticated neutron guide systems take advantage of supermirrors being used to increase the neutron flux. However, the finite reflectivity of supermirrors becomes a major loss mechanism when many reflections occur, e.g. in long neutron guides and for long wavelengths. In order to reduce the number of reflections, ballistic neutron guides have been proposed. Usually linear tapered sections are used to enlarge the cross-section and finally, focus the beam to the sample. The disadvantages of linear tapering are (i) an inhomogeneous phase space at the sample position and (ii) a decreasing flux with increasing distance from the exit of the guide. We investigate the properties of parabolic and elliptic tapering for ballistic neutron guides, using the Monte Carlo program McStas with a new guide component dedicated for such geometries. We show that the maximum flux can indeed be shifted away from the exit of the guide. In addition we explore the possibilities of parabolic and elliptic geometries to create point like sources for dedicated experimental demands.

  10. Advanced geometries for ballistic neutron guides

    Energy Technology Data Exchange (ETDEWEB)

    Schanzer, Christian E-mail: christian.schanzer@frm2.tum.de; Boeni, Peter; Filges, Uwe; Hils, Thomas

    2004-08-21

    Sophisticated neutron guide systems take advantage of supermirrors being used to increase the neutron flux. However, the finite reflectivity of supermirrors becomes a major loss mechanism when many reflections occur, e.g. in long neutron guides and for long wavelengths. In order to reduce the number of reflections, ballistic neutron guides have been proposed. Usually linear tapered sections are used to enlarge the cross-section and finally, focus the beam to the sample. The disadvantages of linear tapering are (i) an inhomogeneous phase space at the sample position and (ii) a decreasing flux with increasing distance from the exit of the guide. We investigate the properties of parabolic and elliptic tapering for ballistic neutron guides, using the Monte Carlo program McStas with a new guide component dedicated for such geometries. We show that the maximum flux can indeed be shifted away from the exit of the guide. In addition we explore the possibilities of parabolic and elliptic geometries to create point like sources for dedicated experimental demands.

  11. Impact of botanical extracts derived from Melia azedarach and Azadirachta indica on populations of Plutella xylostella and its natural enemies: a field test of laboratory findings

    NARCIS (Netherlands)

    Charleston, D.S.; Kfir, R.; Dicke, M.; Vet, L.E.M.

    2006-01-01

    Differences between results from ecological laboratory studies and what actually happens in the field can be large. Therefore, field experiments are essential to validate laboratory findings. In previous laboratory trials we investigated the impact of aqueous leaf extracts from the syringa tree,

  12. Impact of botanical extracts derived from Melia azedarach and Azadirachta indica on populations of Plutella xylostella and its natural enemies: A field test of laboratory findings

    NARCIS (Netherlands)

    Charleston, D.S.; Kfir, R.; Dicke, M.; Vet, L.E.M.

    2006-01-01

    Differences between results from ecological laboratory studies and what actually happens in the field can be large. Therefore, field experiments are essential to validate laboratory findings. In previous laboratory trials we investigated the impact of aqueous leaf extracts from the syringa tree,

  13. Impact of botanical extracts derived from Melia azedarach and Azadirachta indica on populations of Plutella xylostella and its natural enemies: A field test of laboratory findings

    NARCIS (Netherlands)

    Charleston, D.S.; Kfir, R.; Dicke, M.; Vet, L.E.M.

    2006-01-01

    Differences between results from ecological laboratory studies and what actually happens in the field can be large. Therefore, field experiments are essential to validate laboratory findings. In previous laboratory trials we investigated the impact of aqueous leaf extracts from the syringa tree, Mel

  14. Acute Lethality of Inhaled Hydrogen Cyanide in the Laboratory Rat: Impact of Concentration x Time Profile and Evaluation of the Predictivity of Toxic Load Models

    Science.gov (United States)

    2013-05-03

    Naval Medical Research Unit Dayton Acute Lethality of Inhaled Hydrogen Cyanide in the Laboratory Rat : Impact of Concentration × Time Profile and...Cyanide in the Laboratory Rat : Impact of Concentration x Time Profile and Evaluation of the Predictivity of “Toxic Load” Models. 5a. Contract

  15. Impact of mentorship on WHO-AFRO Strengthening Laboratory Quality Improvement Process Towards Accreditation (SLIPTA

    Directory of Open Access Journals (Sweden)

    Talkmore Maruta

    2011-12-01

    Full Text Available Background: The improvment of the quality of testing services in public laboratories is a high priority in many countries. Consequently, initiatives to train laboratory staff on quality management are being implemented, for example, the World Health Organization Regional Headquarters for Africa (WHO-AFRO Strengthening Laboratory Management Towards Accreditation (SLMTA. Mentorship may be an effective way to augment these efforts. Methods: Mentorship was implemented at four hospital laboratories in Lesotho, three districts and one central laboratory, between June 2009 and December 2010. The mentorship model that was implemented had the mentor fully embedded within the operations of each of the laboratories. It was delivered in a series of two mentoring engagements of six and four week initial and follow-up visits respectively. In total, each laboratory received 10 weeks mentorship that was separated by 6–8 weeks. Quality improvements were measured at baseline and at intervals during the mentorship using the WHO-AFRO Strengthening Laboratory Quality Improvement Process Towards Accreditation (SLIPTA checklist and scoring system. Results: At the beginning of the mentorship, all laboratories were at the SLIPTA zero star rating. After the initial six weeks of mentorship, two of the three district laboratories had improved from zero to one (out of five star although the difference between their baseline (107.7 and the end of the six weeks (136.3 average scores was not statistically significant (p = 0.25. After 10 weeks of mentorship there was a significant improvement in average scores (182.3; p = 0.034 with one laboratory achieving WHO-AFRO three out of a possible five star status and the two remaining laboratories achieving a two star status. At Queen Elizabeth II (QE II Central Laboratory, the average baseline score was 44%, measured using a section-specific checklist. There was a significant improvement by five weeks (57.2%; p = 0.021. Conclusion

  16. Influence of the vacuum resin process, on the ballistic behaviour of lightweight armouring solutions

    Directory of Open Access Journals (Sweden)

    Coutellier D.

    2012-08-01

    Full Text Available The armour of vehicles against conventional threats is mainly composed with steel or aluminium panels. Efficient heavy solutions exist, but the involved industries require new lightweight structures. Moreover, unconventional threats as IEDs (Improvised Explosive Devices may cause severe damages on these structural and protective panel solutions. Thus, combination of aluminium or steel plates with textile composite structures used as a backing, leads to the mass reduction and better performance under delamination behaviour against these new threats. This paper is a part of a study dealing with the impact behaviour of three warp interlocks weaving structures under Fragment Simulating Projectile (FSP impact. During this research, several parameters has being studied as the influence of the yarns insertions [1–4], the degradation of the yarns during the weaving process [5–7], and the influence of the resin rate on the ballistic behaviour. The resin rate inside composite materials is dependant on the final application. In ballistic protection, we need to control the resin rate in order to have a deformable structure in order to absorb the maximum of energy. However, with the warp interlocks weaving structure, the yarns insertions induce empty spaces between the yarns where the resin takes place without being evacuated. The resin rate inside the warp interlocks structures is in the most of cases less than 50%, which lead to have brittle and hard material during the impact. Contrary to interlocks structures, the existing protection based on prepreg structure have a high fibres ratio around 88% of weight. That leads to have the best ballistic properties during the impact and good deformability of the structure. The aim of this paper is to evaluate the influence of the resin rate on the ballistic results of the composites materials. For that, we have chosen two kinds of warp interlocks fabrics which were infused with epoxy resin following two

  17. Influence of the vacuum resin process, on the ballistic behaviour of lightweight armouring solutions

    Science.gov (United States)

    Lefebvre, M.; Boussu, F.; Coutellier, D.; Vallee, D.

    2012-08-01

    The armour of vehicles against conventional threats is mainly composed with steel or aluminium panels. Efficient heavy solutions exist, but the involved industries require new lightweight structures. Moreover, unconventional threats as IEDs (Improvised Explosive Devices) may cause severe damages on these structural and protective panel solutions. Thus, combination of aluminium or steel plates with textile composite structures used as a backing, leads to the mass reduction and better performance under delamination behaviour against these new threats. This paper is a part of a study dealing with the impact behaviour of three warp interlocks weaving structures under Fragment Simulating Projectile (FSP) impact. During this research, several parameters has being studied as the influence of the yarns insertions [1-4], the degradation of the yarns during the weaving process [5-7], and the influence of the resin rate on the ballistic behaviour. The resin rate inside composite materials is dependant on the final application. In ballistic protection, we need to control the resin rate in order to have a deformable structure in order to absorb the maximum of energy. However, with the warp interlocks weaving structure, the yarns insertions induce empty spaces between the yarns where the resin takes place without being evacuated. The resin rate inside the warp interlocks structures is in the most of cases less than 50%, which lead to have brittle and hard material during the impact. Contrary to interlocks structures, the existing protection based on prepreg structure have a high fibres ratio around 88% of weight. That leads to have the best ballistic properties during the impact and good deformability of the structure. The aim of this paper is to evaluate the influence of the resin rate on the ballistic results of the composites materials. For that, we have chosen two kinds of warp interlocks fabrics which were infused with epoxy resin following two processes. The first is a

  18. Laboratory Assessment of Potential Impacts to Dungeness Crabs from Disposal of Dredged Material from the Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Vavrinec, John; Pearson, Walter H.; Kohn, Nancy P.; Skalski, J. R.; Lee, Cheegwan; Hall, Kathleen D.; Romano, Brett A.; Miller, Martin C.; Khangaonkar, Tarang P.

    2007-05-07

    Dredging of the Columbia River navigation channel has raised concerns about dredging-related impacts on Dungeness crabs (Cancer magister) in the estuary, mouth of the estuary, and nearshore ocean areas adjacent to the Columbia River. The Portland District, U.S. Army Corps of Engineers engaged the Marine Sciences Laboratory (MSL) of the U.S. Department of Energy’s Pacific Northwest National Laboratory to review the state of knowledge and conduct studies concerning impacts on Dungeness crabs resulting from disposal during the Columbia River Channel Improvement Project and annual maintenance dredging in the mouth of the Columbia River. The present study concerns potential effects on Dungeness crabs from dredged material disposal specific to the mouth of the Columbia River.

  19. Survivability of copper projectiles during hypervelocity impacts in porous ice: A laboratory investigation of the survivability of projectiles impacting comets or other bodies

    Science.gov (United States)

    McDermott, K. H.; Price, M. C.; Cole, M.; Burchell, M. J.

    2016-04-01

    During hypervelocity impact (>a few km s-1) the resulting cratering and/or disruption of the target body often outweighs interest on the outcome of the projectile material, with the majority of projectiles assumed to be vaporised. However, on Earth, fragments, often metallic, have been recovered from impact sites, meaning that metallic projectile fragments may survive a hypervelocity impact and still exist within the wall, floor and/or ejecta of the impact crater post-impact. The discovery of the remnant impactor composition within the craters of asteroids, planets and comets could provide further information regarding the impact history of a body. Accordingly, we study in the laboratory the survivability of 1 and 2 mm diameter copper projectiles fired onto ice at speeds between 1.00 and 7.05 km s-1. The projectile was recovered intact at speeds up to 1.50 km s-1, with no ductile deformation, but some surface pitting was observed. At 2.39 km s-1, the projectile showed increasing ductile deformation and broke into two parts. Above velocities of 2.60 km s-1 increasing numbers of projectile fragments were identified post impact, with the mean size of the fragments decreasing with increasing impact velocity. The decrease in size also corresponds with an increase in the number of projectile fragments recovered, as with increasing shock pressure the projectile material is more intensely disrupted, producing smaller and more numerous fragments. The damage to the projectile is divided into four classes with increasing speed and shock pressure: (1) minimal damage, (2) ductile deformation, start of break up, (3) increasing fragmentation, and (4) complete fragmentation. The implications of such behaviour is considered for specific examples of impacts of metallic impactors onto Solar System bodies, including LCROSS impacting the Moon, iron meteorites onto Mars and NASA's "Deep Impact" mission where a spacecraft impacted a comet.

  20. Impact of laboratory accreditation on patient care and the health system.

    Science.gov (United States)

    Peter, Trevor F; Rotz, Philip D; Blair, Duncan H; Khine, Aye-Aye; Freeman, Richard R; Murtagh, Maurine M

    2010-10-01

    Accreditation is emerging as a preferred framework for building quality medical laboratory systems in resource-limited settings. Despite the low numbers of laboratories accredited to date, accreditation has the potential to improve the quality of health care for patients through the reduction of testing errors and attendant decreases in inappropriate treatment. Accredited laboratories can become more accountable and less dependent on external support. Efforts made to achieve accreditation may also lead to improvements in the management of laboratory networks by focusing attention on areas of greatest need and accelerating improvement in areas such as supply chain, training, and instrument maintenance. Laboratory accreditation may also have a positive influence on performance in other areas of health care systems by allowing laboratories to demonstrate high standards of service delivery. Accreditation may, thus, provide an effective mechanism for health system improvement yielding long-term benefits in the quality, cost-effectiveness, and sustainability of public health programs. Further studies are needed to strengthen the evidence on the benefits of accreditation and to justify the resources needed to implement accreditation programs aimed at improving the performance of laboratory systems.

  1. Laboratory Studies of the Impact of Fish School Density and Individual Distribution on Acoustic Propagation and Scattering

    Science.gov (United States)

    2012-09-30

    obtained, all below resonance. Fig. 5. The 1-D acoustic resonator with live zebra fish (Danio rerio). Fig. 6. Preliminary measured...of one of the zebra fish used in the resonator measurements is shown. This data was processed to show bones in reddish/pink/white colors and the...DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Laboratory Studies of the Impact of Fish School Density and

  2. Investigating the impact of vegetation on alluvial fans using laboratory experiments

    Science.gov (United States)

    Clarke, Lucy; McLelland, Stuart; Tom, Coutlhard

    2016-04-01

    Riparian vegetation can significantly influence the geomorphology of fluvial systems, affecting channel geometry and flow dynamics. However, there is still limited understanding of the role vegetation plays in the development of alluvial fans, despite the large number of vegetated fans located in temperate and humid climates. An understanding of the feedback loops between water flow, sediment dynamics and vegetation is key to understanding the geomorphological response of alluvial fans. But it is difficult to investigate these relationships in the natural world due to the complexity of the geomorphic and biological processes and timescales involved, whereas the controlled conditions afforded by laboratory experiments provide the ideal opportunity to explore these relationships. To examine the effects of vegetation on channel form, flow dynamics and morphology during fan evolution, a series of experiments were conducted using the Total Environment Simulator (operated by the University of Hull). The experiments followed a 'similarity of processes' approach and so were not scaled to a specific field prototype. Live vegetation (Medicago Sativa) was used to simulate the influence of vegetation on the fan development. A range of experiments were conducted on 2x2m fan plots, the same initial conditions and constant water discharge and sediment feed rates were used, but the vegetation density and amount of geomorphic time (when the sediment and water were running and there was active fan development) between seeding / vegetation growth varied between runs. The fan morphology was recorded at regular intervals using a laser scanner (at 1mm resolution) and high resolution video recording and overhead photography were used to gain near-continuous data quantifying fan topography, flow patterns, channel migration and avulsion frequency. Image analysis also monitored the spatial extent of vegetation establishment. The use of these techniques allowed collection of high resolution

  3. Active infrared systems: possible roles in ballistic missile defense?

    Science.gov (United States)

    Paleologue, A.

    2006-05-01

    Active Infra-Red (IR) systems developed in the past ten years are now available for missile defense applications. The main purpose of this paper is to describe the advantages an active IR system could offer to a ballistic missile defense (BMD). The active IR system considered in this paper is a LIDAR (LIght Detection And Ranging) system. Historically, the Lincoln Laboratory in the USA began using lasers in the early 1960's. The initial applications included the development of a LIDAR system enabling the measurement of the distance between the earth and the moon in 1962. Satellite tracking using LIDAR began early in 1973. Today, technological developments, with the miniaturization of systems and increased performance levels, have enabled new ambitious projects such as the Discrimination Interceptor Technology Program (DITP) program started in 1998 and the use of LIDAR to help in the discrimination of future exo-atmospheric interceptors within the framework of BMD. The first part of this paper presents the possible contribution of LIDAR to BMD: the main roles, objectives, and strategic advantages. The second part gives a brief overview of the technological features of a generic LIDAR instrument, rapidly addressing laser sources, detectors, optics and electronics. Finally, a modeling of an IR LIDAR system, limited solely to direct detection, and an estimation of performance levels will be presented. A list of possible IR active discriminators will be then presented on the basis of the previous analysis and proposed as new constraints in the design of discrete objects.

  4. Ballistic Trauma: Lessons Learned from Iraq and Afghanistan

    Science.gov (United States)

    Shin, Emily H.; Sabino, Jennifer M.; Nanos, George P.; Valerio, Ian L.

    2015-01-01

    Management of upper extremity injuries secondary to ballistic and blast trauma can lead to challenging problems for the reconstructive surgeon. Given the recent conflicts in Iraq and Afghanistan, advancements in combat-casualty care, combined with a high-volume experience in the treatment of ballistic injuries, has led to continued advancements in the treatment of the severely injured upper extremity. There are several lessons learned that are translatable to civilian trauma centers and future conflicts. In this article, the authors provide an overview of the physics of ballistic injuries and principles in the management of such injuries through experience gained from military involvement in Iraq and Afghanistan. PMID:25685099

  5. Simulations of Special Interior Ballistic Phenomena with and without Heat Transfer to Gun Tube Wall.

    Science.gov (United States)

    1986-05-01

    Schmitt 9 PERFORMING ORGANIZATION NAME AND ADDRESS 1C. PROGPAM ELEMENT. PROJEC7, -’,,, AREA ’i WORK UNIT NUMSEPS U.S. Army Ballistic Research laboratory...the projectile base, we set Tw =Tamb, across the wall thickness, that is, we assume that the projectile moves into an area which is at ambient...Communications - SMCAR-SCA Electronics Command L. Stiefel ATTN: AMSEL-ED B. Brodman Fort Monmouth, NJ 07703-5301 Dover, NJ 07801-5001 1 Commander 4 Commander

  6. A Short-Barrelled 105-mm Howitzer for Interior Ballistic Studies

    Science.gov (United States)

    1983-01-01

    PROGRAM ELEMENT, PROJECT, TASK AREA 4 WORK UNIT NUMBERS US Army Ballistic Research Laboratory ATTN: DRDAR-BLI 1L162618AH80 Aberdeen Proving Ground...P )A b f where Pb = Pressure acting on base of the projectile Pf = Engraving and resistive pressure and A = Cross-sectional area of the bore; w...Army Armament R&D Command ATTN: DRDAR-SCA, L. Stiefel B. Brodman DRDAR-LCB-I, D. Spring DRDAR-LCE, R. Walker DRDAR-LCU-CT E. Barrieres R

  7. An experimental study on characteristics of cavitation and ballistic of axisymmetric slender body underwater movement

    Science.gov (United States)

    Zhao, Cheng-Gong; Wang, Cong; Wei, Ying-Jie; Zhang, Xiao-Shi

    2015-12-01

    An experimental study of the axisymmetric slender body underwater movement was conducted using high-speed photography technology. From the results of the experiment, the characteristics of cavitation and ballistic of the axisymmetric, including the formation, development, evolution and collapse of the cavity, are presented in the paper. The experimental results show that the axisymmetric slender body moves in a supercavity, and the slender body rotate in the supercavity on its head at the same time due to the perturbation of launching. The supercavity wall is transparent and smooth except the tail itself. The impact between the tail of slender body and supercavity wall resulted from the slender body's rotation is termed as tail- slap which is one way to keep the stabilization of the movement. Series of different flow mechanisms and the relationship between ballistic characteristics and cavity characteristics with defferent initial velocities are discussed. The slender bodies have different accelerations and ballistics with different initial velocity which means they have different drag forces.

  8. Impact of obesity on functional and laboratory parameters in patients with rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Abdou Ellabban

    2016-01-01

    Conclusion Obese RA patients had higher disease activity parameters, clinical scores and laboratory indices, and worse functional outcomes compared with nonobese patients. Higher serum leptin levels were associated with higher disease activity scores.

  9. Impact of Recent Constraints on Intellectual Freedom on Science and Technology at Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J

    2000-11-12

    The Lawrence Livermore National Laboratory (LLNL) was created in 1952 to meet the nation's need for an expanded nuclear weapons research and development (R&D) capability. LLNL quickly grew to become a full-fledged nuclear weapons design laboratory with a broad range of technical capabilities similar to those of our sister laboratory--Los Alamos--with which we shared mission responsibilities. By its very nature, nuclear weapons R&D requires some of the most advanced science and technology (S&T). Accordingly, there is an obvious need for careful attention to ensure that appropriate security measures exist to deal with the sensitive aspects of nuclear weapons development. The trade-off between advancing S&T at the Laboratory and the need for security is a complex issue that has always been with us, As Edward Teller noted in a recent commentary in a May, 1999 editorial in the New York Times: ''The reaction of President Harry Truman to the leaking of information is well known. He imposed no additional measures for security. Instead, we have clear knowledge that the disclosures by (Klaus) Fuchs caused Truman to call for accelerated work on all aspects of nuclear weapons. The right prescription for safety is not reaction to dangers that are arising, but rather action leading to more knowledge and, one hopes, toward positive interaction between nations.'' To explore the issue of intellectual freedom at a national security laboratory such as LLNL, one must understand the type of activities we pursue and how our research portfolio has evolved since the Laboratory was established. Our mission affects the workforce skills, capabilities, and security measures that the Laboratory requires. The national security needs of the US have evolved, along with the S&T community in which the Laboratory resides and to which it contributes. These factors give rise to a greater need for the Laboratory to interact with universities, industry, and other national

  10. Aging ballistic Lévy walks

    Science.gov (United States)

    Magdziarz, Marcin; Zorawik, Tomasz

    2017-02-01

    Aging can be observed for numerous physical systems. In such systems statistical properties [like probability distribution, mean square displacement (MSD), first-passage time] depend on a time span ta between the initialization and the beginning of observations. In this paper we study aging properties of ballistic Lévy walks and two closely related jump models: wait-first and jump-first. We calculate explicitly their probability distributions and MSDs. It turns out that despite similarities these models react very differently to the delay ta. Aging weakly affects the shape of probability density function and MSD of standard Lévy walks. For the jump models the shape of the probability density function is changed drastically. Moreover for the wait-first jump model we observe a different behavior of MSD when ta≪t and ta≫t .

  11. Real-world ballistics: A dropped bucket

    CERN Document Server

    Hogg, David W

    2007-01-01

    I discuss an apparently simple ballistics problem: the time it takes an object to fall a small vertical distance near the surface of the Earth. It turns out to be not so simple; I spend a great deal of time on the quantitative assessment of the assumptions involved, especially with regards to the influence of the air. The point is \\emph{not} to solve the problem; indeed I don't even end up solving the problem exactly. I introduce dimensional analysis to perform all of the calculations approximately. The principal theme of the lecture is that \\emph{real} physics can be very different from ``textbook'' physics, since in the real world you aren't ever told what equations are appropriate, or why.

  12. Ballistics firearm identification by digital holography

    Institute of Scientific and Technical Information of China (English)

    LI Dong-guang

    2009-01-01

    The need for firearm identification systems by police services continues to increase with greater accessibility to weapons in the national and international contexts. The difficulties associated with traditional imaging of ballistics specimens are numerous, and include the smallness of the samples, the nature of the surfaces and shapes for the cartridge cases and projectiles. The digital holography has been introduced to create the 3D image of the fired bullets in order to identify firearms. In digital holography a CCD camera records optically generated holograms which is then reconstructed numerically by a calculation of scalar diffraction in the Fresnel approximation. The digital photography facilitates real time transmission of the message via traditional communication methods. In this paper the principle of digital holography and its application to the 3D image encryption-decryption were reviewed. The experimental results of firearm identification recording using digital holography and their numerical reconstruction were presented.

  13. Scaling and shadowing effects in ballistic aggregation

    Science.gov (United States)

    Joag, P. S.; Limaye, A. V.; Amritkar, R. E.

    1987-10-01

    We have studied the scaling and shadowing properties of two-dimensional off-lattice ballistic aggregation on a seed. The computer simulations show that the limiting semivertical cone angle is about 15.5°. The density as a function of distance from the seed tends to a constant value showing a basic two-dimensional nature of the aggregates and has a correction with a metadimension of about 0.56. The density as a function of angle near the edges of the cone is found to obey a scaling relation similar to the on-lattice case. The probabilities for the fingers of different lengths which shadow the particle near the edge are determined in the computer experiment and also determined analytically.

  14. Ballistic miniband conduction in a graphene superlattice

    Science.gov (United States)

    Lee, Menyoung; Wallbank, John R.; Gallagher, Patrick; Watanabe, Kenji; Taniguchi, Takashi; Fal'ko, Vladimir I.; Goldhaber-Gordon, David

    2016-09-01

    Rational design of long-period artificial lattices yields effects unavailable in simple solids. The moiré pattern in highly aligned graphene/hexagonal boron nitride (h-BN) heterostructures is a lateral superlattice with high electron mobility and an unusual electronic dispersion whose miniband edges and saddle points can be reached by electrostatic gating. We investigated the dynamics of electrons in moiré minibands by measuring ballistic transport between adjacent local contacts in a magnetic field, known as the transverse electron focusing effect. At low temperatures, we observed caustics of skipping orbits extending over hundreds of superlattice periods, reversals of the cyclotron revolution for successive minibands, and breakdown of cyclotron motion near van Hove singularities. At high temperatures, electron-electron collisions suppress focusing. Probing such miniband conduction properties is a necessity for engineering novel transport behaviors in superlattice devices.

  15. Gate tuneable beamsplitter in ballistic graphene

    Energy Technology Data Exchange (ETDEWEB)

    Rickhaus, Peter; Makk, Péter, E-mail: Peter.Makk@unibas.ch; Schönenberger, Christian [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Liu, Ming-Hao; Richter, Klaus [Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg (Germany)

    2015-12-21

    We present a beam splitter in a suspended, ballistic, multiterminal, bilayer graphene device. By using local bottomgates, a p-n interface tilted with respect to the current direction can be formed. We show that the p-n interface acts as a semi-transparent mirror in the bipolar regime and that the reflectance and transmittance of the p-n interface can be tuned by the gate voltages. Moreover, by studying the conductance features appearing in magnetic field, we demonstrate that the position of the p-n interface can be moved by 1 μm. The herein presented beamsplitter device can form the basis of electron-optic interferometers in graphene.

  16. Ballistic Missile Defense: New Plans, Old Challenges

    Directory of Open Access Journals (Sweden)

    Elizabeth Zolotukhina

    2010-01-01

    Full Text Available On September 17, 2009—the 70th anniversary of the Soviet invasion of Poland in 1939 that marked the beginning of World War II—the Obama Administration announced its intention to shelve plans for the U.S. Ballistic Missile Defense (BMD that had been developed under former President George W. Bush. Pointing to a new intelligence assessment, President Obama argued that his predecessor's plan to deploy an X-band radar station outside of Prague, Czech Republic, and 10 two-stage interceptor missiles in Poland would not adequately protect America and its European allies from the Iranian threat and reiterated his opposition to utilizing unproven technology in any European BMD architecture.

  17. Ballistic energy transport in PEG oligomers

    Directory of Open Access Journals (Sweden)

    Kireev Victor V.

    2013-03-01

    Full Text Available Energy transport between the terminal groups of the azido-PEG-succinimide ester compounds with a number of repeating PEG units of 0, 4, 8, and 12 was studied using relaxation-assisted two-dimensional infrared spectroscopy. The through-bond energy transport time, evaluated as the waiting time at which the cross peak maximum is reached, Tmax, was found to be linearly dependent on the chain length for chain lengths up to 60 Å suggesting a ballistic energy transport regime. The through-bond energy transport speed is found to be ca. 500 m/s. The cross-peak amplitude at the maximum decays exponentially with the chain length with a characteristic decay distance of 15.7 ± 1 Å. Substantial mode delocalization across the PEG bridge is found, which can support the energy propagation as a wavepacket.

  18. Performance of Lead-Free versus Lead-Based Hunting Ammunition in Ballistic Soap

    Science.gov (United States)

    Gremse, Felix; Krone, Oliver; Thamm, Mirko; Kiessling, Fabian; Tolba, René Hany; Rieger, Siegfried; Gremse, Carl

    2014-01-01

    Background Lead-free hunting bullets are an alternative to lead-containing bullets which cause health risks for humans and endangered scavenging raptors through lead ingestion. However, doubts concerning the effectiveness of lead-free hunting bullets hinder the wide-spread acceptance in the hunting and wildlife management community. Methods We performed terminal ballistic experiments under standardized conditions with ballistic soap as surrogate for game animal tissue to characterize dimensionally stable, partially fragmenting, and deforming lead-free bullets and one commonly used lead-containing bullet. The permanent cavities created in soap blocks are used as a measure for the potential wound damage. The soap blocks were imaged using computed tomography to assess the volume and shape of the cavity and the number of fragments. Shots were performed at different impact speeds, covering a realistic shooting range. Using 3D image segmentation, cavity volume, metal fragment count, deflection angle, and depth of maximum damage were determined. Shots were repeated to investigate the reproducibility of ballistic soap experiments. Results All bullets showed an increasing cavity volume with increasing deposited energy. The dimensionally stable and fragmenting lead-free bullets achieved a constant conversion ratio while the deforming copper and lead-containing bullets showed a ratio, which increases linearly with the total deposited energy. The lead-containing bullet created hundreds of fragments and significantly more fragments than the lead-free bullets. The deflection angle was significantly higher for the dimensionally stable bullet due to its tumbling behavior and was similarly low for the other bullets. The deforming bullets achieved higher reproducibility than the fragmenting and dimensionally stable bullets. Conclusion The deforming lead-free bullet closely resembled the deforming lead-containing bullet in terms of energy conversion, deflection angle, cavity shape

  19. Performance of lead-free versus lead-based hunting ammunition in ballistic soap.

    Science.gov (United States)

    Gremse, Felix; Krone, Oliver; Thamm, Mirko; Kiessling, Fabian; Tolba, René Hany; Rieger, Siegfried; Gremse, Carl

    2014-01-01

    Lead-free hunting bullets are an alternative to lead-containing bullets which cause health risks for humans and endangered scavenging raptors through lead ingestion. However, doubts concerning the effectiveness of lead-free hunting bullets hinder the wide-spread acceptance in the hunting and wildlife management community. We performed terminal ballistic experiments under standardized conditions with ballistic soap as surrogate for game animal tissue to characterize dimensionally stable, partially fragmenting, and deforming lead-free bullets and one commonly used lead-containing bullet. The permanent cavities created in soap blocks are used as a measure for the potential wound damage. The soap blocks were imaged using computed tomography to assess the volume and shape of the cavity and the number of fragments. Shots were performed at different impact speeds, covering a realistic shooting range. Using 3D image segmentation, cavity volume, metal fragment count, deflection angle, and depth of maximum damage were determined. Shots were repeated to investigate the reproducibility of ballistic soap experiments. All bullets showed an increasing cavity volume with increasing deposited energy. The dimensionally stable and fragmenting lead-free bullets achieved a constant conversion ratio while the deforming copper and lead-containing bullets showed a ratio, which increases linearly with the total deposited energy. The lead-containing bullet created hundreds of fragments and significantly more fragments than the lead-free bullets. The deflection angle was significantly higher for the dimensionally stable bullet due to its tumbling behavior and was similarly low for the other bullets. The deforming bullets achieved higher reproducibility than the fragmenting and dimensionally stable bullets. The deforming lead-free bullet closely resembled the deforming lead-containing bullet in terms of energy conversion, deflection angle, cavity shape, and reproducibility, showing that

  20. Performance of lead-free versus lead-based hunting ammunition in ballistic soap.

    Directory of Open Access Journals (Sweden)

    Felix Gremse

    Full Text Available BACKGROUND: Lead-free hunting bullets are an alternative to lead-containing bullets which cause health risks for humans and endangered scavenging raptors through lead ingestion. However, doubts concerning the effectiveness of lead-free hunting bullets hinder the wide-spread acceptance in the hunting and wildlife management community. METHODS: We performed terminal ballistic experiments under standardized conditions with ballistic soap as surrogate for game animal tissue to characterize dimensionally stable, partially fragmenting, and deforming lead-free bullets and one commonly used lead-containing bullet. The permanent cavities created in soap blocks are used as a measure for the potential wound damage. The soap blocks were imaged using computed tomography to assess the volume and shape of the cavity and the number of fragments. Shots were performed at different impact speeds, covering a realistic shooting range. Using 3D image segmentation, cavity volume, metal fragment count, deflection angle, and depth of maximum damage were determined. Shots were repeated to investigate the reproducibility of ballistic soap experiments. RESULTS: All bullets showed an increasing cavity volume with increasing deposited energy. The dimensionally stable and fragmenting lead-free bullets achieved a constant conversion ratio while the deforming copper and lead-containing bullets showed a ratio, which increases linearly with the total deposited energy. The lead-containing bullet created hundreds of fragments and significantly more fragments than the lead-free bullets. The deflection angle was significantly higher for the dimensionally stable bullet due to its tumbling behavior and was similarly low for the other bullets. The deforming bullets achieved higher reproducibility than the fragmenting and dimensionally stable bullets. CONCLUSION: The deforming lead-free bullet closely resembled the deforming lead-containing bullet in terms of energy conversion

  1. The economic impact of Sandia National Laboratories on Central New Mexico and the State of New Mexico Fiscal Year 1998

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, Robert R.; Adcock, Larry D.; Gentry, Lucille M.; Ben-David, Shaul; Temple, John

    1999-08-09

    Sandia National Laboratories (SNL) is a Department of Energy federally funded national security laboratory that uses engineering and science to ensure the security of the Nation. SNL provides scientific and engineering solutions to meet national needs in nuclear weapons and related defense systems, energy security, and environmental integrity. SNL works in partnerships with universities and industry to enhance their mission and transfer technology that will address emerging national challenges for both government and industry. For several years, the U.S. Department of Energy (DOE) Albuquerque Operations Office (AL) and New Mexico State University (NMSU) have maintained an inter-industry, input-output (I/O) model with capabilities to assess the impacts of developments initiated outside the economy such as federal DOE monies that flow into the state, on an economy. This model will be used to assess economic, personal income and employment impacts of SNL on Central New Mexico and the State of New Mexico. Caution should be exercised when comparing economic impacts between fiscal years prior to this report. The I/O model was rebased for FY 1998. The fringe benefits coefficients have been updated for the FY 1996 and FY 1997 economic impacts analysis. Prior to FY 1993 two different I/O base models were used to estimate the impacts. New technical information was released by the Bureau of Economic Analysis (BEA), U.S. Department of Commerce in 1991 and in 1994 and was incorporated in FY 1991, FY 1993, and FY 1994 I/O models. Also in 1993, the state and local tax coefficients and expenditure patterns were updated from a 1986 study for the FY 1992 report. Further details about the input-output model can be found in ''The Economic Impact of the Department of Energy on the State of New Mexico--FY 1998'' report by Lansford, et al. (1999). For this report, the reference period is FY 1998 (October 1, 1997, through September 30, 1998) and includes two major

  2. Computer and laboratory simulation in the teaching of neonatal nursing: innovation and impact on learning 1

    Science.gov (United States)

    Fonseca, Luciana Mara Monti; Aredes, Natália Del' Angelo; Fernandes, Ananda Maria; Batalha, Luís Manuel da Cunha; Apóstolo, Jorge Manuel Amado; Martins, José Carlos Amado; Rodrigues, Manuel Alves

    2016-01-01

    ABSTRACT Objectives: to evaluate the cognitive learning of nursing students in neonatal clinical evaluation from a blended course with the use of computer and laboratory simulation; to compare the cognitive learning of students in a control and experimental group testing the laboratory simulation; and to assess the extracurricular blended course offered on the clinical assessment of preterm infants, according to the students. Method: a quasi-experimental study with 14 Portuguese students, containing pretest, midterm test and post-test. The technologies offered in the course were serious game e-Baby, instructional software of semiology and semiotechnique, and laboratory simulation. Data collection tools developed for this study were used for the course evaluation and characterization of the students. Nonparametric statistics were used: Mann-Whitney and Wilcoxon. Results: the use of validated digital technologies and laboratory simulation demonstrated a statistically significant difference (p = 0.001) in the learning of the participants. The course was evaluated as very satisfactory for them. The laboratory simulation alone did not represent a significant difference in the learning. Conclusions: the cognitive learning of participants increased significantly. The use of technology can be partly responsible for the course success, showing it to be an important teaching tool for innovation and motivation of learning in healthcare. PMID:27737376

  3. JEDI: Jobs and Economic Development Impact Model; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    The Jobs and Economic Development Impact (JEDI) models are user-friendly tools that estimate the economic impacts of constructing and operating power generation and biofuel plants at the local (usually state) level. First developed by NREL’s researchers to model wind energy jobs and impacts, JEDI has been expanded to also estimate the economic impacts of biofuels, coal, conventional hydro, concentrating solar power, geothermal, marine and hydrokinetic power, natural gas, photovoltaics, and transmission lines. This fact sheet focuses on JEDI for wind energy projects.

  4. Microbial contamination of removable prosthodontic appliances from laboratories and impact of clinical storage.

    Science.gov (United States)

    Williams, D W; Chamary, N; Lewis, M A O; Milward, P J; McAndrew, R

    2011-08-26

    Decontamination of dental instruments has recently been the subject of considerable debate. However, little information is available on the potential bacterial colonisation of dental appliances returning from dental laboratories and their need for decontamination. This study investigated the extent and nature of microbial contamination of removable prosthodontic appliances produced at different dental laboratories and stored in two clinical teaching units (CTU 1 and CTU 2) of a dental hospital and school. Forty consecutive dental prosthodontic appliances that were being stored under varying conditions in the two clinical teaching units were selected for study; the appliances having been produced 'in-house' (hospital laboratory) or 'out-of-house' (external commercial laboratory). Two appliances, that were known to have undergone decontamination before storage, were used as controls. Swabs were taken according to a standard protocol and transferred to the microbiological laboratory with bacterial growth expressed as colony forming units (cfu) per cm(2). Microbial sampling yielded growth from 23 (58%) of the 40 appliances studied (CTU 1, n = 22; CTU 2, n = 18), with 38% of these having a high level of contamination (>42,000 cfu/cm(2)). The predominant bacteria isolated were Bacillus spp. (57%), pseudomonads (22%) and staphylococci (13%). Fungi of the genus Candida were detected in 38% of the samples. There was no significant difference in contamination of the appliances in relation to either their place of production or the CTU (p >0.05). However, the level of contamination was significantly higher (p = 0.035) for those appliances stored in plastic bag with fluid (n = 16) compared to those stored on models (n = 19). No growth was recovered from the two appliances that had undergone decontamination before storage. The research showed that appliances received from laboratories are often contaminated and therefore there is a need for routine disinfection of such items

  5. The method of neutron imaging as a tool for the study of the dynamics of water movement in wet aramid-based ballistic body armour panels

    Science.gov (United States)

    Reifler, Felix A.; Lehmann, Eberhard H.; Frei, Gabriel; May, Hans; Rossi, René

    2006-07-01

    A new non-destructive method based on neutron imaging (neutron radiography) to determine the exact water content in aramid-based soft body armour panels is presented. While investigating the ballistic resistance of aramid-based body armour panels under a wet condition, it is important to precisely determine their water content and its chronological development. Using the presented method, the influence of water amount and location on impact testing as well as its time dependence was shown. In the ballistic panels used, spreading of water strongly depended on the kind of quilting. Very fast water migration could be observed when the panels were held vertically. Some first results regarding the water distribution in wet panels immediately after the impact are presented. On the basis of the presented results, requirements for a standard for testing the performance of ballistic panels in the wet state are deduced.

  6. The ballistic Mars hopper: An alternative Mars mobility concept

    OpenAIRE

    1987-01-01

    The ballistic Mars hopper is proposed as an alternative mobility concept for unmanned exploration of the martian surface. In the ballistic Mars hopper concept, oxygen and carbon monoxide produced from the martian atmosphere are used as propellants in a rocket propulsion system for an unmanned vehicle on suborbital trajectories between landing sights separated by distances of up to 1000 km. This mobility concept is seen as uniquely capable of allowing both intensive and extensive exploration o...

  7. Impact of the January-February 1980 earthquake sequence on various structures at the Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Murray, R.C.; Nelson, T.A.; Coats, D.W.; Ng, D.S.; Weaver, H.J.

    1981-02-04

    On January 24, 1980, California's Livermore Valley was rocked by a moderate earthquake that caused some damage to the Lawrence Livermore National Laboratory (LLNL). The earthquake, which measured 5.5 on the Richter scale and was centered about 20 km (12 mi) northwest of the Laboratory, produced estimated peak horizontal ground acceleration at LLNL of between 0.15 and 0.3 g. The earthquake was part of a sequence that included two sharp aftershocks (magnitudes 5.2 and 4.2) within 1.5 minutes of the initial event. A second earthquake (magnitude 5.8) struck on January 26, and several lesser earthquakes occurred during the next few weeks. This paper describes the damage impact of the January 24 earthquake, including: background information on LLNL, discussion of pre-earthquake seismic safety philosophy, and description of the impact of the January 24 earthquake, including a description of the seismic setting of the Laboratory, a discussion of the ground motion, and a summary of damage. This paper also describes a data gathering and reduction effort at LLNL in the aftermath of the January earthquakes.

  8. A Computational Investigation of the Multi-Hit Ballistic-Protection Performance of Laminated Transparent-armor Systems

    Science.gov (United States)

    Grujicic, Mica; Pandurangan, B.; Coutris, N.

    2012-06-01

    Multi-hit ballistic-protection performance of a prototypical laminated glass/polycarbonate transparent armor is investigated using a series of transient nonlinear dynamics analyses of armor impact with a sequence of four M2AP full metal jacket (FMJ) armor-piercing bullets. All calculations were carried out using ABAQUS/Explicit commercial finite element program (ABAQUS Version 6.7, User Documentation, Dessault Systems, 2007), and the computational results obtained were compared to their experimental counterparts obtained by Dolan (Ballistic Transparent-armor Testing Using a Multi-hit Rifle Pattern, Bachelors, Thesis, Kettering University, December 2007). The comparison revealed that (a) The proposed computational procedure can reasonably well account for the observed multi-hit ballistic-protection performance of the laminated transparent armor; (b) The role of prior bullet hits in reducing armor's ballistic-protection performance is clearly revealed; (c) The role of polycarbonate lamina in preventing glass fragments from entering the vehicle interior is clearly demonstrated; and (d) Experimentally observed inability of the transparent armor to defeat 0.50-caliber Fragment Simulating Projectiles (FSPs) is confirmed.

  9. The stress and ballistic properties of granular materials

    Science.gov (United States)

    Proud, William G.; Chapman, David J.; Eakins, Daniel E.

    2017-01-01

    Granular materials are widespread in nature and in manufacturing. Their particulate nature gives a compressive strength of a similar order of magnitude as many continuous solids, a vanishingly small tensile strength and variable shear strength, highly dependent on the loading conditions. Previous studies have shown the effect of composition, morphology and particle size, however, compared to metals and polymers, granular materials are not so well understood. This paper will present some recent results for granular materials, placing these within the wider context. Two areas will be dealt with (i) the effect of the skeletal strength of the material and (ii) the displacements associated with ballistic impact. One clear observation is the similarity of behavior of quartz-sands in compression across a range of particle size. However, the precise pathway of compression is strongly dependent on the initial conditions e.g. density and connectivity within the granular bed, as emphasized by some data for quasi-static compression of sand. To fully embrace the range of behaviours seen requires the development of a suitable parameter to describe the material, the paper concludes with a discussion of one of those approaches.

  10. Boxing and mixed martial arts: preliminary traumatic neuromechanical injury risk analyses from laboratory impact dosage data.

    Science.gov (United States)

    Bartsch, Adam J; Benzel, Edward C; Miele, Vincent J; Morr, Douglas R; Prakash, Vikas

    2012-05-01

    In spite of ample literature pointing to rotational and combined impact dosage being key contributors to head and neck injury, boxing and mixed martial arts (MMA) padding is still designed to primarily reduce cranium linear acceleration. The objects of this study were to quantify preliminary linear and rotational head impact dosage for selected boxing and MMA padding in response to hook punches; compute theoretical skull, brain, and neck injury risk metrics; and statistically compare the protective effect of various glove and head padding conditions. An instrumented Hybrid III 50th percentile anthropomorphic test device (ATD) was struck in 54 pendulum impacts replicating hook punches at low (27-29 J) and high (54-58 J) energy. Five padding combinations were examined: unpadded (control), MMA glove-unpadded head, boxing glove-unpadded head, unpadded pendulum-boxing headgear, and boxing glove-boxing headgear. A total of 17 injury risk parameters were measured or calculated. All padding conditions reduced linear impact dosage. Other parameters significantly decreased, significantly increased, or were unaffected depending on padding condition. Of real-world conditions (MMA glove-bare head, boxing glove-bare head, and boxing glove-headgear), the boxing glove-headgear condition showed the most meaningful reduction in most of the parameters. In equivalent impacts, the MMA glove-bare head condition induced higher rotational dosage than the boxing glove-bare head condition. Finite element analysis indicated a risk of brain strain injury in spite of significant reduction of linear impact dosage. In the replicated hook punch impacts, all padding conditions reduced linear but not rotational impact dosage. Head and neck dosage theoretically accumulates fastest in MMA and boxing bouts without use of protective headgear. The boxing glove-headgear condition provided the best overall reduction in impact dosage. More work is needed to develop improved protective padding to minimize

  11. Rainfall and wet and dry cycle's impact on ash thickness. A laboratory experiment

    Science.gov (United States)

    Pereira, Paulo; Keestra, Saskia; Peters, Piet; Cerdà, Artemi

    2016-04-01

    Ash is the most important and effective soil protection in the immediate period after the fire (Cerda and Doerr, 2008; Pereira et al., 2015a). This protection can last for days or weeks depending on the fire severity, topography of the burned area and post-fire meteorological conditions. In the initial period after the fire, ash is easily transported by wind. However after the first rainfalls, ash is eroded, or bind in soil surface (Pereira et al., 2013, 2015a). Ash thickness has implications on soil protection. The soil protection against the erosion and the ash capacity to retain water increases with the ash thickness (Bodi et al., 2014). Ash cover is very important after fire because store water and releases into soil a large amount of nutrients, fundamental to vegetation recuperation (Pereira et al., 2014). Despite the importance of ash thickness in post fire environments, little information is available about the effects of rainfall and wet and dry cycle's effects on ash thickness. This work aims to fill this gap. The objective of this study is to investigate the impacts of rainfall and wet and dry cycles in the ash thickness of two different under laboratory conditions. Litter from Oak (Quercus robur) and Spruce (Picea abis) were collected to and exposed during 2 hours to produce ash at 200 and 400 C. Subsequently a layer of 15 mm ash was spread on soil surface in small boxes (24x32 cm) and then subjected to rainfall simulation. Boxes were placed at a 17% of inclination and a rainfall intensity of 55 mm/h during 40 minutes was applied. After the rainfall simulation the plots were stored in an Oven at the temperature of 25 C during four days, in order to identify the effects of wet and dry cycles (Bodi et al., 2013). Ash thickness was measured after the first rainfall (AFR), before the second rainfall (BSR) - after the dry period of 4 days - and after the second rainfall (ASR). In each box a grid with 57 points was designed in order to analyse ash thickness

  12. Development, Use, and Impact of a Global Laboratory Database During the 2014 Ebola Outbreak in West Africa.

    Science.gov (United States)

    Durski, Kara N; Singaravelu, Shalini; Teo, Junxiong; Naidoo, Dhamari; Bawo, Luke; Jambai, Amara; Keita, Sakoba; Yahaya, Ali Ahmed; Muraguri, Beatrice; Ahounou, Brice; Katawera, Victoria; Kuti-George, Fredson; Nebie, Yacouba; Kohar, T Henry; Hardy, Patrick Jowlehpah; Djingarey, Mamoudou Harouna; Kargbo, David; Mahmoud, Nuha; Assefa, Yewondwossen; Condell, Orla; N'Faly, Magassouba; Van Gurp, Leon; Lamanu, Margaret; Ryan, Julia; Diallo, Boubacar; Daffae, Foday; Jackson, Dikena; Malik, Fayyaz Ahmed; Raftery, Philomena; Formenty, Pierre

    2017-06-15

    The international impact, rapid widespread transmission, and reporting delays during the 2014 Ebola outbreak in West Africa highlighted the need for a global, centralized database to inform outbreak response. The World Health Organization and Emerging and Dangerous Pathogens Laboratory Network addressed this need by supporting the development of a global laboratory database. Specimens were collected in the affected countries from patients and dead bodies meeting the case definitions for Ebola virus disease. Test results were entered in nationally standardized spreadsheets and consolidated onto a central server. From March 2014 through August 2016, 256343 specimens tested for Ebola virus disease were captured in the database. Thirty-one specimen types were collected, and a variety of diagnostic tests were performed. Regular analysis of data described the functionality of laboratory and response systems, positivity rates, and the geographic distribution of specimens. With data standardization and end user buy-in, the collection and analysis of large amounts of data with multiple stakeholders and collaborators across various user-access levels was made possible and contributed to outbreak response needs. The usefulness and value of a multifunctional global laboratory database is far reaching, with uses including virtual biobanking, disease forecasting, and adaption to other disease outbreaks.

  13. Laboratory Instrumentation: An Exploration of the Impact of Instrumentation on Student Learning

    Science.gov (United States)

    Warner, Don L.; Brown, Eric C.; Shadle, Susan E.

    2016-01-01

    Academic programs generally work to make their laboratory curriculum both as instrumentation rich and up to date as possible. However, little is known about the relationship between the use of instrumentation in the curriculum and student learning. As part of our department's ongoing assessment efforts, a project was designed to probe this…

  14. Open-Ended versus Guided Laboratory Activities: Impact on Students' Beliefs about Experimental Physics

    Science.gov (United States)

    Wilcox, Bethany R.; Lewandowski, H. J.

    2016-01-01

    Improving students' understanding of the nature of experimental physics is often an explicit or implicit goal of undergraduate laboratory physics courses. However, lab activities in traditional lab courses are typically characterized by highly structured, guided labs that often do not require or encourage students to engage authentically in the…

  15. Open-Ended versus Guided Laboratory Activities: Impact on Students' Beliefs about Experimental Physics

    Science.gov (United States)

    Wilcox, Bethany R.; Lewandowski, H. J.

    2016-01-01

    Improving students' understanding of the nature of experimental physics is often an explicit or implicit goal of undergraduate laboratory physics courses. However, lab activities in traditional lab courses are typically characterized by highly structured, guided labs that often do not require or encourage students to engage authentically in the…

  16. Proposals for the mitigation of the environmental impact of clinical laboratories.

    Science.gov (United States)

    Lopez, Joseph B; Badrick, Tony

    2012-03-24

    Laboratories should be aware of the carbon footprint resulting from their activities and take steps to mitigate it as part of their societal responsibilities. Once committed to a mitigation programme, they should announce an environmental policy, secure the support of senior management, initiate documentation, institute a staff training programme, schedule environmental audits and appoint an environmental manager. Laboratories may aspire to be accredited to one of the standards for environmental management, such as the ISO 14000. As environmental and quality issues are linked, the improvement in the environmental management of an organisation will ultimately lead to improved quality system performance. Indeed, environmental management could conceivably come under overall quality management. Although there will be initial costs, good environmental practices can bring savings. Environmental improvement should be based on the 3R concept to reduce, reuse and recycle. Several policy initiatives may be introduced. These include a green purchasing policy for equipment, laboratory furniture and reagents as well as the management of packaging wastes. There are several ways to reduce energy, water usage and wastage. A reduction of test numbers and collection tubes should be attempted. Paper management involves all aspects of 3R. The recycling of solvents and general wastes should be practised where feasible. The construction new laboratories or renovations to existing ones are opportunities to make them more environmentally-friendly. The advocacy of policies to associates and the inclusion of environmentally-friendly conditions on contractors are integral parts of the programme.

  17. Impact of Collaborative Groups versus Individuals in Undergraduate Inquiry-Based Astronomy Laboratory Learning Exercises

    Science.gov (United States)

    Sibbernsen, Kendra J.

    2014-01-01

    A mixed-method quasi-experimental study was designed to determine how 130 undergraduates in an introductory astronomy survey course laboratory changed their understanding of scientific inquiry working as individuals in relative isolation compared to working in small, collaborative learning groups when using specially designed astronomy curricula…

  18. The impact of standard preparation practice on the runoff and soil erosion rates under laboratory conditions

    Science.gov (United States)

    Khaledi Darvishan, Abdulvahed; Homayounfar, Vafa; Hamidreza Sadeghi, Seyed

    2016-09-01

    The use of laboratory methods in soil erosion studies, rainfall simulation experiments, Gerlach troughs, and other measurements such as ring infiltrometer has been recently considered more and more because of many advantages in controlling rainfall properties and high accuracy of sampling and measurements. However, different stages of soil removal, transfer, preparation and placement in laboratory plots cause significant changes in soil structure and, subsequently, the results of runoff, sediment concentration and soil loss. Knowing the rate of changes in sediment concentration and soil loss variables with respect to the soil preparation for laboratory studies is therefore inevitable to generalize the laboratory results to field conditions. However, there has been little attention given to evaluate the effects of soil preparation on sediment variables. The present study was therefore conducted to compare sediment concentration and soil loss in natural and prepared soil. To achieve the study purposes, 18 field 1 × 1 m plots were adopted in an 18 % gradient slope with sandy-clay-loam soil in the Kojour watershed, northern Iran. A portable rainfall simulator was then used to simulate rainfall events using one or two nozzles of BEX: 3/8 S24W for various rainfall intensities with a constant height of 3 m above the soil surface. Three rainfall intensities of 40, 60 and 80 mm h-1 were simulated on both prepared and natural soil treatments with three replications. The sediment concentration and soil loss at five 3 min intervals after time to runoff were then measured. The results showed the significant increasing effects of soil preparation (p ≤ 0.01) on the average sediment concentration and soil loss. The increasing rates of runoff coefficient, sediment concentration and soil loss due to the study soil preparation method for laboratory soil erosion plots were 179, 183 and 1050 % (2.79, 2.83 and 11.50 times), respectively.

  19. JEDI: Jobs and Economic Development Impacts Model, National Renewable Energy Laboratory (NREL) (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2009-12-01

    The Jobs and Economic Development Impact (JEDI) models are user-friendly tools that estimate the economic impacts of constructing and operating power generation and biofuel plants at the local (usually state) level. First developed by NREL's Wind Powering America program to model wind energy jobs and impacts, JEDI has been expanded to biofuels, concentrating solar power, coal, and natural gas power plants. Based on project-specific and default inputs (derived from industry norms), JEDI estimates the number of jobs and economic impacts to a local area (usually a state) that could reasonably be supported by a power generation project. For example, JEDI estimates the number of in-state construction jobs from a new wind farm. This fact sheet provides an overview of the JEDI model as it pertains to wind energy projects.

  20. Dynamics and thermal sensitivity of ballistic and non-ballistic feeding in salamanders.

    Science.gov (United States)

    Deban, Stephen M; Scales, Jeffrey A

    2016-02-01

    Low temperature reduces the performance of muscle-powered movements, but in movements powered by elastic recoil mechanisms, this effect can be mitigated and performance can be increased. To better understand the morphological basis of high performance and thermal robustness of elastically powered movements, we compared feeding dynamics at a range of temperatures (5-25°C) in two species of terrestrial plethodontid salamanders, Plethodon metcalfi and Ensatina eschscholtzii, which differ in tongue muscle architecture and the mechanism of tongue projection. We found that Ensatina is capable of ballistic projection with a mean muscle mass-specific power of 2100 W kg(-1), revealing an elastic mechanism. Plethodon, in contrast, projected its tongue non-ballistically with a mean power of only 18 W kg(-1), indicating it is muscle powered. Ensatina projected its tongue significantly farther than Plethodon and with dynamics that had significantly lower thermal sensitivity at temperatures below 15°C. These performance differences were correlated with morphological differences, namely elongated collagenous aponeuroses in the projector muscle of Ensatina as compared with Plethodon, which are likely the site of energy storage, and the absence in Ensatina of projector muscle fibers attaching to the tongue skeleton that allows projection to be truly ballistic. These findings demonstrate that, in these otherwise similar species, the presence in one species of elaborated connective tissue in series with myofibers confers not only 10-fold greater absolute performance but also greater thermal robustness of performance. We conclude that changes in muscle and connective tissue architecture are sufficient to alter significantly the mechanics, performance and thermal robustness of musculoskeletal systems.

  1. Laboratory Validation of Two Wearable Sensor Systems for Measuring Head Impact Severity in Football Players.

    Science.gov (United States)

    Siegmund, Gunter P; Guskiewicz, Kevin M; Marshall, Stephen W; DeMarco, Alyssa L; Bonin, Stephanie J

    2016-04-01

    Wearable sensors can measure head impact frequency and magnitude in football players. Our goal was to quantify the impact detection rate and validity of the direction and peak kinematics of two wearable sensors: a helmet system (HITS) and a mouthguard system (X2). Using a linear impactor, modified Hybrid-III headform and one helmet model, we conducted 16 impacts for each system at 12 helmet sites and 5 speeds (3.6-11.2 m/s) (N = 896 tests). Peak linear and angular accelerations (PLA, PAA), head injury criteria (HIC) and impact directions from each device were compared to reference sensors in the headform. Both sensors detected ~96% of impacts. Median angular errors for impact directions were 34° for HITS and 16° for X2. PLA, PAA and HIC were simultaneously valid at 2 sites for HITS (side, oblique) and one site for X2 (side). At least one kinematic parameter was valid at 2 and 7 other sites for HITS and X2 respectively. Median relative errors for PLA were 7% for HITS and -7% for X2. Although sensor validity may differ for other helmets and headforms, our analyses show that data generated by these two sensors need careful interpretation.

  2. Ballistic analysis during multiscale explosive eruption at Vesuvius and hazard implications

    Science.gov (United States)

    De Novellis, Vincenzo

    2016-04-01

    Ballistic Projectiles (BP) are rock-basement or magma fragments of variable size and density that are ejected from vents during explosive eruptions and follow almost parabolic trajectories that are influenced by gravity and drag forces before they reach their impact point on the surface. During the past century, numerous observers have described the violent ejection of large blocks and bombs from volcanoes during volcanic explosions. Starting from '40 years of last century, several authors developed a mathematical expression relating initial velocity and trajectory angle of ejected blocks to the range, taking into account air drag and assuming a constant drag coefficient; but only in the last 30 years was developed the first mathematical algorithm for ballistic trajectories in the volcanological literature that considered variations in drag coefficient with Reynolds number. Finally, with 21st century computer power, ballistic computation should be available to anyone as a back-of-the-envelope indicator of explosive power by a user-friendly computer program. At Mt. Vesuvius a series of explosion events accompanied eruptive mechanism stages during its history. In particular the explosive eruptive events at Vesuvius was affected by 3 types of energy activity: i) a normal strombolian activity that consists of rhythmic, mild to moderate explosions lasting a few seconds that eject scoriaceous lapilli and bombs, ash and lithic blocks; ii) a vulcanian or violent explosions characterized by short-lived events involving more than one vent, defined as strombolian paroxysms; iii) from sublinian to plinian activity, that have been the most powerful events observed at Mt. Vesuvius; on the other hand plinian was indicated as the energetic term to define the most famous eruption of 79 AD. In this study, an eruptive model appropriate for exanimated eruptions, is used to estimate initial conditions (ejection height, take-off angle, velocity) for BP, assuming a broad range of gas

  3. The Impact of Recent Advances in Laboratory Astrophysics on our Understanding of the Cosmos

    CERN Document Server

    Savin, D W; Cowan, J J; Drake, R P; Federman, S R; Ferland, G J; Frank, A; Gudipati, M S; Haxton, W C; Herbst, E; Profumo, S; Salama, F; Ziurys, L M; Zweibe, E G

    2011-01-01

    An emerging theme in modern astrophysics is the connection between astronomical observations and the underlying physical phenomena that drive our cosmos. Both the mechanisms responsible for the observed astrophysical phenomena and the tools used to probe such phenomena - the radiation and particle spectra we observe - have their roots in atomic, molecular, condensed matter, plasma, nuclear and particle physics. Chemistry is implicitly included in both molecular and condensed matter physics. This connection is the theme of the present report, which provides a broad, though non-exhaustive, overview of progress in our understanding of the cosmos resulting from recent theoretical and experimental advances in what is commonly called laboratory astrophysics. This work, carried out by a diverse community of laboratory astrophysicists, is increasingly important as astrophysics transitions into an era of precise measurement and high fidelity modeling.

  4. The impact of recent advances in laboratory astrophysics on our understanding of the cosmos.

    Science.gov (United States)

    Savin, D W; Brickhouse, N S; Cowan, J J; Drake, R P; Federman, S R; Ferland, G J; Frank, A; Gudipati, M S; Haxton, W C; Herbst, E; Profumo, S; Salama, F; Ziurys, L M; Zweibel, E G

    2012-03-01

    An emerging theme in modern astrophysics is the connection between astronomical observations and the underlying physical phenomena that drive our cosmos. Both the mechanisms responsible for the observed astrophysical phenomena and the tools used to probe such phenomena-the radiation and particle spectra we observe-have their roots in atomic, molecular, condensed matter, plasma, nuclear and particle physics. Chemistry is implicitly included in both molecular and condensed matter physics. This connection is the theme of the present report, which provides a broad, though non-exhaustive, overview of progress in our understanding of the cosmos resulting from recent theoretical and experimental advances in what is commonly called laboratory astrophysics. This work, carried out by a diverse community of laboratory astrophysicists, is increasingly important as astrophysics transitions into an era of precise measurement and high fidelity modeling.

  5. The impact of meningococcal polymerase chain reaction testing on laboratory confirmation of invasive meningococcal disease.

    LENUS (Irish Health Repository)

    Drew, Richard J

    2012-03-01

    Laboratory methods of diagnosis were examined for 266 children with invasive meningococcal disease. Seventy-five (36%) of 207 cases with bloodstream infection had both positive blood culture and blood meningococcal polymerase chain reaction (PCR), 130 (63%) negative blood culture and positive blood PCR, and 2 (1%) had positive blood culture and negative blood PCR. Sixty-three percent of cases were diagnosed by PCR alone.

  6. The Impact of Internet Virtual Physics Laboratory Instruction on the Achievement in Physics, Science Process Skills and Computer Attitudes of 10th-Grade Students

    Science.gov (United States)

    Yang, Kun-Yuan; Heh, Jia-Sheng

    2007-01-01

    The purpose of this study was to investigate and compare the impact of Internet Virtual Physics Laboratory (IVPL) instruction with traditional laboratory instruction in physics academic achievement, performance of science process skills, and computer attitudes of tenth grade students. One-hundred and fifty students from four classes at one private…

  7. Measurement and simulation of the impact of coherent synchrotron radiation on the Jefferson Laboratory energy recovery linac electron beam

    Science.gov (United States)

    Hall, C. C.; Biedron, S. G.; Edelen, A. L.; Milton, S. V.; Benson, S.; Douglas, D.; Li, R.; Tennant, C. D.; Carlsten, B. E.

    2015-03-01

    In an experiment conducted on the Jefferson Laboratory IR free-electron laser driver, the effects of coherent synchrotron radiation (CSR) on beam quality were studied. The primary goal of this work was to explore CSR output and effect on the beam with variation of the bunch compression in the IR recirculator. Here we examine the impact of CSR on the average energy loss as a function of bunch compression as well as the impact of CSR on the energy spectrum of the bunch. Simulation of beam dynamics in the machine, including the one-dimensional CSR model, shows very good agreement with the measured effect of CSR on the average energy loss as a function of compression. Finally, a well-defined structure is observed in the energy spectrum with a feature in the spectrum that varies as a function of the compression. This effect is examined in simulations, as well, and a simple explanation for the variation is proposed.

  8. Electron quantum optics in ballistic chiral conductors

    Energy Technology Data Exchange (ETDEWEB)

    Bocquillon, Erwann; Freulon, Vincent; Parmentier, Francois D.; Berroir, Jean-Marc; Placais, Bernard; Feve, Gwendal [Laboratoire Pierre Aigrain, Ecole Normale Superieure, CNRS (UMR 8551), Universite Pierre et Marie Curie, Universite Paris Diderot, Paris (France); Wahl, Claire; Rech, Jerome; Jonckheere, Thibaut; Martin, Thierry [Aix Marseille Universite, CNRS, CPT, UMR 7332, Marseille (France); Universite de Toulon, CNRS, CPT, UMR 7332, La Garde (France); Grenier, Charles; Ferraro, Dario; Degiovanni, Pascal [Universite de Lyon, Federation de Physique Andre Marie Ampere, CNRS - Laboratoire de Physique de l' Ecole Normale Superieure de Lyon, Lyon (France)

    2014-01-15

    The edge channels of the quantum Hall effect provide one dimensional chiral and ballistic wires along which electrons can be guided in an optics-like setup. Electronic propagation can then be analyzed using concepts and tools derived from optics. After a brief review of electron optics experiments performed using stationary current sources which continuously emit electrons in the conductor, this paper focuses on triggered sources, which can generate on-demand a single particle state. It first outlines the electron optics formalism and its analogies and differences with photon optics and then turns to the presentation of single electron emitters and their characterization through the measurements of the average electrical current and its correlations. This is followed by a discussion of electron quantum optics experiments in the Hanbury-Brown and Twiss geometry where two-particle interferences occur. Finally, Coulomb interactions effects and their influence on single electron states are considered. (copyright 2013 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Ballistic spin transport in exciton gases

    Science.gov (United States)

    Kavokin, A. V.; Vladimirova, M.; Jouault, B.; Liew, T. C. H.; Leonard, J. R.; Butov, L. V.

    2013-11-01

    Traditional spintronics relies on spin transport by charge carriers, such as electrons in semiconductor crystals. The challenges for the realization of long-range electron spin transport include rapid spin relaxation due to electron scattering. Scattering and, in turn, spin relaxation can be effectively suppressed in excitonic devices where the spin currents are carried by electrically neutral bosonic quasiparticles: excitons or exciton-polaritons. They can form coherent quantum liquids that carry spins over macroscopic distances. The price to pay is a finite lifetime of the bosonic spin carriers. We present the theory of exciton ballistic spin transport which may be applied to a range of systems supporting bosonic spin transport, in particular to indirect excitons in coupled quantum wells. We describe the effect of spin-orbit interaction for the electron and the hole on the exciton spin, account for the Zeeman effect induced by external magnetic fields and long-range and short-range exchange splittings of the exciton resonances. We also consider exciton transport in the nonlinear regime and discuss the definitions of the exciton spin current, polarization current, and spin conductivity.

  10. Superconducting Graphene Nanodevices in Ballistic Transport Regime

    Science.gov (United States)

    Chen, Yu-An; Wang, Joel I.-Jan; Watanabe, Kenji; Taniguchi, Takashi; Jarillo-Herrero, Pablo; Pablo Jarillo-Herrero's Group Team

    2013-03-01

    Superconductivity carried by Dirac fermions can be realized through induced superconductivity in grapheme. Observation of novel phenomena anticipated by theories requires graphene devices with low disorder whereas the carrier transport is ballistic. Current fabrication procedures to make graphene devices with low disorder like suspension or ultra-flat substrates all call for certain kinds of annealing to remove organic residues derived from the fabrication process. Applying these methods to superconducting devices can be challenging since the transparency at the graphene/superconductor interface will be destroyed. Here we present a method to do dry transfer of patterned hexagonal Boron Nitride (hBN) flakes onto graphene. The ultra flatness and lack of dangling bond in the boron nitride substrate reduces the disorder in graphene, and the top layer hBN can protect the graphene from contamination in the nanofabrication procedures and yield the geometry desired for different experimental exploration. National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan

  11. Estimating the shooting distance of a 9-mm Parabellum bullet via ballistic experiment.

    Science.gov (United States)

    Bresson, F; Franck, O

    2009-11-20

    We demonstrate here how the shooting distance of a 9-mm Parabellum FMJ bullet (115gr) has been estimated via shooting experiments. Such a bullet was found by investigators near a concrete wall, fairly distorted at its tip. The bullet carries no evidence of multiple impact and no evidence of ballistic impact on the wall has been reported. We estimated the impact velocity by comparing the questioned bullet with a set of comparison bullets hitting a wall (rigid target) with different velocities. The shooting distance was recovered from the impact velocity by studying the typical behavior of a manufactured 9 mm bullet weighting 115g (7.45g), shot in pistol or a sub-machine gun. The results demonstrated that the questioned bullet was a lost bullet. The shooting distance also helped the investigators, narrowing the range of the estimated positions of the shooter.

  12. Introducing integrated laboratory classes in a PBL curriculum: impact on student’s learning and satisfaction

    Science.gov (United States)

    2013-01-01

    Background With the introduction of integrated problem-based learning (PBL) program in the medical curriculum, there is a need to create laboratory classes that suit students’ learning needs and the changes introduced to the curriculum. This paper outlines the development and implementation of four integrated laboratory classes (ILCs) at King Saud University College of Medicine. It also examines whether core concepts addressed in these classes were learned and retained and how the students perceived the ILCs. Methods ILCs are based on enhancing enquiry-based learning, and encouraging students to work on tasks in small groups (apply and integrate knowledge from biochemistry, pathology and microbiology) and conduct a laboratory procedure (practical part). In two of these ILCs, a pretest comprising 15 multiple-choice questions were administrated at the start of the class and an identical posttest was administrated at the end of these classes. Performance of the students in the Objective Structured Practical Examination (OSPE) at the end of the blocks was also evaluated. Students’ perceptions were evaluated using a questionnaire completed at the end of each class. Results A total of 247, 252, 238, and 244 students participated in practical classes covering cerebrospinal fluid infection, small intestine, liver function tests and adrenal gland function, respectively. Students got higher scores in posttests compared to pre-test scores in two classes (12.68 ± 2.03 vs 6.58 ± 3.39 and 13.02 ± 2.03 vs 7.43 ± 2.68, respectively). Paired t-test showed that the difference was significant (P learning. Conclusions Given the increase in the posttest scores (short-term retention) and the satisfactory performance of students at the end of block examinations (long-term retention) together with the students’ satisfaction, the study suggests that the core concepts addressed in these classes were learned and retained. PMID:23706014

  13. Introducing integrated laboratory classes in a PBL curriculum: impact on student's learning and satisfaction.

    Science.gov (United States)

    Azer, Samy A; Hasanato, Rana; Al-Nassar, Sami; Somily, Ali; AlSaadi, Muslim M

    2013-05-24

    With the introduction of integrated problem-based learning (PBL) program in the medical curriculum, there is a need to create laboratory classes that suit students' learning needs and the changes introduced to the curriculum. This paper outlines the development and implementation of four integrated laboratory classes (ILCs) at King Saud University College of Medicine. It also examines whether core concepts addressed in these classes were learned and retained and how the students perceived the ILCs. ILCs are based on enhancing enquiry-based learning, and encouraging students to work on tasks in small groups (apply and integrate knowledge from biochemistry, pathology and microbiology) and conduct a laboratory procedure (practical part). In two of these ILCs, a pretest comprising 15 multiple-choice questions were administrated at the start of the class and an identical posttest was administrated at the end of these classes. Performance of the students in the Objective Structured Practical Examination (OSPE) at the end of the blocks was also evaluated. Students' perceptions were evaluated using a questionnaire completed at the end of each class. A total of 247, 252, 238, and 244 students participated in practical classes covering cerebrospinal fluid infection, small intestine, liver function tests and adrenal gland function, respectively. Students got higher scores in posttests compared to pre-test scores in two classes (12.68 ± 2.03 vs 6.58 ± 3.39 and 13.02 ± 2.03 vs 7.43 ± 2.68, respectively). Paired t-test showed that the difference was significant (P learning. Given the increase in the posttest scores (short-term retention) and the satisfactory performance of students at the end of block examinations (long-term retention) together with the students' satisfaction, the study suggests that the core concepts addressed in these classes were learned and retained.

  14. LABORATORY EVALUATION OF ZERO-VALENT IRON TO TREAT WATER IMPACTED BY ACID MINE DRAINAGE

    Science.gov (United States)

    This study examines the applicability and limitations of granular zero-valent iron for the treatment of water impacted by mine wastes. Rates of acid neutralization and of metal (Cu, Cd, Ni, Zn, Hg, Al, and Mn) and metalloid (As) uptake were determined in batch systems using simu...

  15. Rotavirus Infection in the Auckland Region Following the Implementation of Universal Infant Rotavirus Vaccination: Impact on Hospitalisations and Laboratory Implications.

    Science.gov (United States)

    McAuliffe, Gary N; Taylor, Susan L; Drinković, Dragana; Roberts, Sally A; Wilson, Elizabeth M; Best, Emma J

    2017-07-19

    In July 2014, New Zealand introduced universal infant vaccination with Rotateq (Merk & Co.) administered as three doses at 6 weeks, 3 and 5 months of age. We sought to assess the impact of rotavirus vaccination on gastroenteritis hospitalizations in the greater Auckland region and analyze changes in rotavirus testing in the period around vaccine introduction. Hospitalizations, laboratory testing rates and methods were compared between the pre-vaccine period (2009-2013), post vaccine period (January-December 2015), and year of vaccine introduction (2014). There was a 68% decline in rotavirus hospitalizations of children aged <5 years following vaccine introduction (from 258 per 100,000 to 83 per 100,000) and a 17% decline in all-cause gastroenteritis admissions (from 1815 per 100,000 to 1293 per 100,000). Reductions were also seen in pediatric groups too old to have received vaccine.Despite these changes, rotavirus testing rates in our region remained static in the year after vaccine introduction compared with the two prior years, and following vaccine introduction we observed a high rate of false positives 19/58 (33%) in patients with reactive rotavirus tests. Rotavirus vaccine has had a significant early impact on gastroenteritis hospitalizations for children in the Auckland region. However, continued rotavirus testing at pre-vaccine rates risks generating false positive results. Laboratories and clinicians should consider reviewing their testing algorithms prior to vaccine introduction.

  16. Shot noise effect on noise source and noise parameter of 10-nm-scale quasi-ballistic n-/p-type MOS devices

    Science.gov (United States)

    Jeon, Jongwook; Kang, Myounggon

    2016-05-01

    In this work, we investigated the noise source and noise parameters of a quasi-ballistic MOSFET at the high-frequency regime. We presented the shot noise properties in the measured drain current noise and its impact on the induced gate noise and the noise parameters of 10-nm-scale n-/p-type MOS (N/PMOS) devices for the first time. The measured noise sources and noise parameters were carefully analyzed with the shot and thermal noise models in all operation regions. On the basis of the results, new noise parameter models are proposed and the noise performance improvement in the quasi-ballistic regime is shown.

  17. An investigation into the behaviour of air rifle pellets in ballistic gel and their interaction with bone.

    Science.gov (United States)

    Wightman, G; Beard, J; Allison, R

    2010-07-15

    Although air weapons are considerably lower in power than other firearms, there is increasing concern that serious injuries can result from their misuse. The present study was therefore carried out to improve understanding of the terminal ballistic behaviour of air rifle pellets. Pellets were fired into ballistic gel under a variety of conditions. The pellets penetrated further than anticipated from their low cross-sectional density, and Bloom number was not necessarily a good guide to gel behaviour. Pellet penetration into the gel decreased with increasing gel concentration, and appeared to be linear at higher concentrations. Pointed pellets penetrated up to 50% further than rounded pellets. Power and range affect penetration, but other factors are also important, and power alone is not a simple guide to potential penetration. Test firings were also carried out firing pellets into ballistic gel that contained sections of animal bone. Computed tomography (CT) and visual observation were employed to record the interactions. CT scanning showed potential as a tool for examining pellet damage. The bone appeared to be undamaged, but the pellets were severely deformed on impact. If the pellet strikes the bone at an angle, less energy is absorbed by the impact and the pellet fragments may ricochet and cause further damage in the gel. A tentative model is proposed for estimating the energy absorbed by the impact.

  18. Temperature management during semen processing: Impact on boar sperm quality under laboratory and field conditions.

    Science.gov (United States)

    Schulze, M; Henning, H; Rüdiger, K; Wallner, U; Waberski, D

    2013-12-01

    Freshly collected boar spermatozoa are sensitive to a fast reduction in temperature because of lipid phase transition and phase separation processes. Temperature management during semen processing may determine the quality of stored samples. The aim of this study was to evaluate the influence of isothermic and hypothermic semen processing protocols on boar sperm quality under laboratory and field conditions. In the laboratory study, ejaculates (n = 12) were first diluted (1:1) with Beltsville Thawing Solution (BTS) at 32 °C, then processed either with isothermic (32 °C) or hypothermic (21 °C) BTS, stored at 17 °C, and assessed on days 1, 3, and 6. Temperature curves showed that 150 minutes after the first dilution, semen doses of both groups reached the same temperature. Two-step hypothermic processing resulted in lower sperm motility on days 1 and 6 (P sperm on days 3 and 6 (P boar semen compared with isothermic dilution and that the type of semen extender affects the outcomes.

  19. Impact of sonography in gouty arthritis: Comparison with conventional radiography, clinical examination, and laboratory findings

    Energy Technology Data Exchange (ETDEWEB)

    Schueller-Weidekamm, Claudia [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)]. E-mail: claudia.schueller-weidekamm@meduniwien.ac.at; Schueller, Gerd [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Aringer, Martin [Department of Rheumatology, Internal Medicine III, Medical University of Vienna (Austria); Weber, Michael [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Kainberger, Franz [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    2007-06-15

    Objective: To explore the typical sonographic features of gray-scale and Power Doppler of acute and chronic gouty arthritis in conjunction with radiographic, clinical, and laboratory findings. Materials and methods: All hand, finger, and toe joints of 19 patients with acute and chronic gout were examined with gray-scale and Power Doppler sonography. The number and size of bone changes detected with sonography was compared to radiographic findings. Vascularization of the synovial tissue was scored on Power Doppler (grades 0-3), and was compared with clinical appearance, including swelling, tenderness, and redness (grades 0-3). Results: In acute gout, mild to moderate echogenic periarticular nodules with sonotransmission and hypervascularization of the edematous surrounding soft tissue were found. In chronic gout, tophaceous nodules completely blocked transmission of US wave, leading to strong reflexion and dorsal shadowing in a minority of cases. No significant difference in the detection of large bone changes (>2 mm) was found between sonography and radiography. However, gray-scale sonography was significantly more sensitive in the detection of small bone changes (p < 0.001). Power Doppler scores were statistically significantly higher than clinical examination scores (p < 0.001). Discussion: Sonography is superior to radiographs in evaluating small bone changes. The inflammatory process in joints can be better detected with Power Doppler sonography than with clinical examination. Typical sonographic appearance of acute and in particular of chronic gout might provide clues on gouty arthritis that adds to the information available from conventional radiography, clinical, and laboratory findings.

  20. Transition to ballistic regime for heat transport in helium II

    Energy Technology Data Exchange (ETDEWEB)

    Sciacca, Michele, E-mail: michele.sciacca@unipa.it [Dipartimento Scienze Agrarie e Forestali, Università degli studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Sellitto, Antonio, E-mail: ant.sellitto@gmail.com [Dipartimento di Matematica, Informatica ed Economia, Università della Basilicata, Campus Macchia Romana, 85100 Potenza (Italy); Jou, David, E-mail: david.jou@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Institut d' Estudis Catalans, Carme 47, 08001 Barcelona, Catalonia (Spain)

    2014-07-04

    The size-dependent and flux-dependent effective thermal conductivity of narrow capillaries filled with superfluid helium is analyzed from a thermodynamic continuum perspective. The classical Landau evaluation of the effective thermal conductivity of quiescent superfluid, or the Gorter–Mellinck regime of turbulent superfluids, is extended to describe the transition to ballistic regime in narrow channels wherein the radius R is comparable to (or smaller than) the phonon mean-free path ℓ in superfluid helium. To do so, we start from an extended equation for the heat flux incorporating non-local terms, and take into consideration a heat slip flow along the walls of the tube. This leads from an effective thermal conductivity proportional to R{sup 2} (Landau regime) to another one proportional to Rℓ (ballistic regime). We consider two kinds of flows: along cylindrical pipes and along two infinite parallel plates. - Highlights: • Heat transport in counterflow helium in the ballistic regime. • The one-fluid model based on the Extended Thermodynamics is used. • The transition from the Landau regime to the ballistic regime. • The transition from quantum turbulence to ballistic regime.

  1. Necessary condition for forward progression in ballistic walking.

    Science.gov (United States)

    Kagawa, Takahiro; Uno, Yoji

    2010-12-01

    Ballistic walking requires an appropriate configuration of posture and velocity at toe-off to avoid backward falling. In this study, we investigated a determinant of the state of the body center of mass (COM) at the toe-off with regard to ballistic walking. We used an inverted pendulum model to represent ballistic trajectories and the necessary condition for forward progression by a simple relationship between the COM states (position and velocity) at toe-off. This condition was validated through a computer simulation of a 7-link musculoskeletal model and measurement experiments of human movements involving stepping and walking. The results of the model simulation were in good agreement with some of the results predicted by the inverted pendulum model. The measurement experiments of walking and stepping movements showed that most COM states at toe-off satisfied the condition for forward progression and the measured trajectories during single support phase were similar to the ballistic trajectories although humans are capable of walking in non-ballistic ways. These results suggested that the necessary condition for forward progression can predict the COM states at toe-off for efficient movement and for avoiding backward falling during single support phase. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Improvement of Interior Ballistic Performance Utilizing Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Hazem El Sadek

    2014-01-01

    Full Text Available This paper investigates the interior ballistic propelling charge design using the optimization methods to select the optimum charge design and to improve the interior ballistic performance. The propelling charge consists of a mixture propellant of seven-perforated granular propellant and one-hole tubular propellant. The genetic algorithms and some other evolutionary algorithms have complex evolution operators such as crossover, mutation, encoding, and decoding. These evolution operators have a bad performance represented in convergence speed and accuracy of the solution. Hence, the particle swarm optimization technique is developed. It is carried out in conjunction with interior ballistic lumped-parameter model with the mixture propellant. This technique is applied to both single-objective and multiobjective problems. In the single-objective problem, the optimization results are compared with genetic algorithm and the experimental results. The particle swarm optimization introduces a better performance of solution quality and convergence speed. In the multiobjective problem, the feasible region provides a set of available choices to the charge’s designer. Hence, a linear analysis method is adopted to give an appropriate set of the weight coefficients for the objective functions. The results of particle swarm optimization improved the interior ballistic performance and provided a modern direction for interior ballistic propelling charge design of guided projectile.

  3. Impact of Seasonal Variant Temperatures and Laboratory Room Ambient Temperature on Mortality of Rats with Ischemic Brain Injury

    Science.gov (United States)

    Gopalakrishanan, Sivakumar; Babu, Mg. Ramesh; Thangarajan, Rajesh; Punja, Dhiren; Jaganath, Vidyadhara Devarunda; Kanth, Akriti B.; Rao, Mohandas

    2016-01-01

    Introduction A popular rat model for hypoperfusion ischemic brain injury is bilateral common carotid artery occlusion (BCCAO). BCCAO surgery when performed in varying geographical locations and during different seasons of the year is reported to have variable mortality rates. Studies have also documented the diminishing influence of Ketamine-Xylazine (KT-XY) on thermoregulatory functions in rodents. Aim To explore the impact of seasonal variant temperatures and laboratory room ambient temperatures on mortality of rats following BCCAO surgery. Materials and Methods The study has two parts: 1 The first part is an analysis of a three year retrospective data to explore the association between the geographical season (hot summer and cold winter) induced laboratory room ambient temperature variations and the mortality rate in KT-XY anaesthetized BCCAO rats. 2. The second part investigated the effect of conditioned laboratory room ambient temperature (CAT) (23-250C) in KT-XY anaesthetized BCCAO group of rats. Rats were divided into 4 groups(n =8/group) as-Normal control, BCCAO and Sham BCCAO where they were all exposed to unconditioned ambient temperature (UCAT) during their surgery and postoperative care. And finally fourth group rats exposed to CAT during the BCCAO surgery and postoperative care. Results Pearson’s chi-square test indicates a significantly high association (p<0.006) between post-BCCAO mortality and hot season of the year. CAT during the hot season reduced the mortality rate (24% less) in post- BCCAO rats compared to the rats of UCAT. Conclusion Despite seasonal variations in temperature, conditioning the laboratory room ambient temperatures to 23–250C, induces hypothermia in KT-XY anaesthetized ischemic brain injured rodents and improves their survival rate. PMID:27190796

  4. Understanding Energy Impacts of Oversized Air Conditioners; NREL Highlights, Research & Development, NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-06-01

    This NREL highlight describes a simulation-based study that analyzes the energy impacts of oversized residential air conditioners. Researchers found that, if parasitic power losses are minimal, there is very little increase in energy use for oversizing an air conditioner. The research demonstrates that new residential air conditioners can be sized primarily based on comfort considerations, because capacity typically has minimal impact on energy efficiency. The results of this research can be useful for contractors and homeowners when choosing a new air conditioner or heat pump during retrofits of existing homes. If the selected unit has a crankcase heater, performing proper load calculations to be sure the new unit is not oversized will help avoid excessive energy use.

  5. Laboratory Measurements of Micrometeoroid Impacts into Solid Ice and Gas Ablation Targets

    Science.gov (United States)

    Munsat, T. L.; Britt, D. T.; Dee, R.; Gudipati, M. S.; Horanyi, M.; James, D.; Janches, D.; Kempf, S.; Nelson, A. O.; Plane, J. M. C.; Shu, A. J.; Sternovsky, Z.; Thomas, E.; Ulibarri, Z.

    2015-12-01

    The dust accelerator facility at the SSERVI Institute for Modeling Plasma, Atmospheres, and Cosmic Dust (IMPACT) has recently implemented two major target upgrades: a cryogenic ice target and a high-pressure gas target. Each target can be exposed to micron and submicron particles accelerated to speeds up to 100 km/s. The ice target consists of a LN2 cryogenic system connected to both a water-ice deposition system and a movable freezer/holder for a pre-mixed liquid cartridge. Impact products and chemistry are assessed with an integrated time-of-flight mass spectrometer. Such a system enables a program of research into the evolution of ice under micrometeoroid bombardment and the synthesis of complex organic molecules through micrometeoroid impacts. We present the early results from studies of hypervelocity iron particle impacts into frozen mixtures of H2O, NH3, and olivine grains which contain nanophase Fe, a possible catalyst for organic chemical reactions, under conditions of low-pressure background CO or CO2 gas. The gas target consists of a differentially pumped chamber kept at pressures up to 0.5 Torr, such that high-velocity (~10-60 km/s) micrometeoroids are completely ablated within the 40 cm long measurement region. The chamber is configured with segmented electrodes to perform temporally- and spatially-resolved measurements of charge production during ablation, and localized light-collection optics enable an assessment of the light production. We present the latest results of experiments to determine the ionization efficiency of Fe particles ablating in N2, air, CO2, and He gas, and modifications to standard ablation models made possible from these experimental results. Such studies are critical for the interpretation of remote sensing measurements, including radar and lidar, which in turn make possible the assessment of the interplanetary dust particle flux.

  6. The diet board: welfare impacts of a novel method of dietary restriction in laboratory rats

    DEFF Research Database (Denmark)

    Kasanen, I H E; Inhilä, K J; Vainio, O M

    2009-01-01

    Laboratory rats are commonly fed ad libitum (AL). Moderate dietary restriction (DR) decreases mortality and morbidity when compared with AL feeding, but there are several obstacles to the implementation of DR. Traditional methods of restricted feeding disrupt normal diurnal eating rhythms...... and are not compatible with group housing. We have designed a novel method, the diet board, to restrict the feeding of group-housed rats. Animals fed from the diet board had 15% lower body weight than the AL-fed animals at the age of 17 weeks. The welfare effects of diet board feeding were assessed by comparing...... to solve the health problems associated with AL feeding, while allowing the rats to be group-housed and to maintain their normal diurnal eating rhythms. The diet board can also be seen as a functional cage furniture item, dividing the cage into compartments and thus increasing the structural complexity...

  7. Relationship between Ballistic Coefficient and Static Mechanical Properties for Armor Materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The relationship between the ballistic coefficient and the static mechanical properties of armor materials was studied. The results show that the ballistic coefficient is determined by the strength, hardness and the toughness of materials. According to the Martel rule, the equation of the relationship between ballistic coefficient and static mechanical properties satisfies the following formula: . From the mixture law of composite, the prerequisite, for which ballistic coefficient has maximum to reinforcement volume fraction, is obtained by the following equation: .

  8. Computer and laboratory simulation in the teaching of neonatal nursing: innovation and impact on learning.

    Science.gov (United States)

    Fonseca, Luciana Mara Monti; Aredes, Natália Del' Angelo; Fernandes, Ananda Maria; Batalha, Luís Manuel da Cunha; Apóstolo, Jorge Manuel Amado; Martins, José Carlos Amado; Rodrigues, Manuel Alves

    2016-10-10

    to evaluate the cognitive learning of nursing students in neonatal clinical evaluation from a blended course with the use of computer and laboratory simulation; to compare the cognitive learning of students in a control and experimental group testing the laboratory simulation; and to assess the extracurricular blended course offered on the clinical assessment of preterm infants, according to the students. a quasi-experimental study with 14 Portuguese students, containing pretest, midterm test and post-test. The technologies offered in the course were serious game e-Baby, instructional software of semiology and semiotechnique, and laboratory simulation. Data collection tools developed for this study were used for the course evaluation and characterization of the students. Nonparametric statistics were used: Mann-Whitney and Wilcoxon. the use of validated digital technologies and laboratory simulation demonstrated a statistically significant difference (p = 0.001) in the learning of the participants. The course was evaluated as very satisfactory for them. The laboratory simulation alone did not represent a significant difference in the learning. the cognitive learning of participants increased significantly. The use of technology can be partly responsible for the course success, showing it to be an important teaching tool for innovation and motivation of learning in healthcare. avaliar a aprendizagem cognitiva de estudantes de enfermagem na avaliação clínica neonatal a partir de um curso semipresencial com uso de simulação por computador e em laboratório; comparar a aprendizagem cognitiva dos estudantes em grupo controle e experimental ao testar a simulação em laboratório; e avaliar o curso semipresencial extracurricular oferecido sobre avaliação clínica do bebê pré-termo, segundo os estudantes. estudo quase-experimental com 14 estudantes portugueses contendo pré-teste, teste intermediário e pós-teste. As tecnologias oferecidas no curso foram serious

  9. Novel formulations of ballistic gelatin. 1. Rheological properties.

    Science.gov (United States)

    Zecheru, Teodora; Său, Ciprian; Lăzăroaie, Claudiu; Zaharia, Cătălin; Rotariu, Traian; Stănescu, Paul-Octavian

    2016-06-01

    Ballistic gelatin is the simulant of the human body during field tests in forensics and other related fields, due to its physical and mechanical similarities to human trunk and organs. Since the ballistic gelatin used in present has important issues to overcome, an alternative approach is the use of gelatin-polymer composites, where a key factor is the insertion of biocompatible materials, which replicate accurately the human tissues. In order to be able to obtain an improved material in terms of mechanical performances by an easy industrial-scale technology, before the verification of the ballistic parameters by shooting in agreement with military standards, one of the best and cheapest solutions is to perform a thorough check of their rheological properties, in standard conditions.

  10. ["Piggyback" shot: ballistic parameters of two simultaneously discharged airgun pellets].

    Science.gov (United States)

    Frank, Matthias; Schönekess, Holger C; Grossjohann, Rico; Ekkernkamp, Axel; Bockholdt, Britta

    2014-01-01

    Green and Good reported an uncommon case of homicide committed with an air rifle in 1982 (Am. J. Forensic Med. Pathol. 3: 361-365). The fatal wound was unusual in that two airgun pellets were loaded in so-called "piggyback" fashion into a single shot air rifle. Lack of further information on the ballistic characteristics of two airgun pellets as opposed to one conventionally loaded projectile led to this investigation. The mean kinetic energy (E) of the two pellets discharged in "piggyback" fashion was E = 3.6 J and E = 3.4 J, respectively. In comparison, average kinetic energy values of E = 12.5 J were calculated for conventionally discharged single diabolo pellets. Test shots into ballistic soap confirmed the findings of a single entrance wound as reported by Green and Good. While the ballistic background of pellets discharged in "piggyback" fashion could be clarified, the reason behind this mode of shooting remains unclear.

  11. Ballistic spin filtering across the ferromagnetic-semiconductor interface

    Directory of Open Access Journals (Sweden)

    Y.H. Li

    2012-03-01

    Full Text Available The ballistic spin-filter effect from a ferromagnetic metal into a semiconductor has theoretically been studied with an intention of detecting the spin polarizability of density of states in FM layer at a higher energy level. The physical model for the ballistic spin filtering across the interface between ferromagnetic metals and semiconductor superlattice is developed by exciting the spin polarized electrons into n-type AlAs/GaAs superlattice layer at a much higher energy level and then ballistically tunneling through the barrier into the ferromagnetic film. Since both the helicity-modulated and static photocurrent responses are experimentally measurable quantities, the physical quantity of interest, the relative asymmetry of spin-polarized tunneling conductance, could be extracted experimentally in a more straightforward way, as compared with previous models. The present physical model serves guidance for studying spin detection with advanced performance in the future.

  12. Learning without knowing: subliminal visual feedback facilitates ballistic motor learning

    DEFF Research Database (Denmark)

    Lundbye-Jensen, Jesper; Leukel, Christian; Nielsen, Jens Bo

    by subconscious (subliminal) augmented visual feedback on motor performance. To test this, 45 subjects participated in the experiment, which involved learning of a ballistic task. The task was to execute simple ankle plantar flexion movements as quickly as possible within 200 ms and to continuously improve...... ballistic rate of force development (RFD) throughout a series of 40 trials. Following each trial subjects were provided visual augmented feedback on their performance in the form of dots presented on a monitor. The y-axis amplitude of the dots represented the obtained RFD. Participants were individually...... received supraliminal as compared to subliminal feedback. In the 0 ms feedback group motor performance increased only slightly indicating an important role of augmented feedback in learning the ballistic task. In the two groups who received subliminal feedback none of the subjects were able to tell what...

  13. Design and Manufacturing Process for a Ballistic Missile

    Directory of Open Access Journals (Sweden)

    Zaharia Sebastian Marian

    2016-12-01

    Full Text Available Designing a ballistic missile flight depends on the mission and the stress to which the missile is subject. Missile’s requests are determined by: the organization of components; flight regime type, engine configuration and aerodynamic performance of the rocket flight. In this paper has been developed a ballistic missile with a smooth fuselage type, 10 control surfaces, 8 directional surfaces for cornering execution, 2 for maneuvers of execution to change the angle of incidence and 4 stabilizers direction. Through the technology of gluing and clamping of the shell and the use of titanium components, mass of ballistic missile presented a significant decrease in weight and a structure with high strength.

  14. Laboratory experiments on the impact disruption of iron meteorites at temperature of near-Earth space

    Science.gov (United States)

    Katsura, Takekuni; Nakamura, Akiko M.; Takabe, Ayana; Okamoto, Takaya; Sangen, Kazuyoshi; Hasegawa, Sunao; Liu, Xun; Mashimo, Tsutomu

    2014-10-01

    Iron meteorites and some M-class asteroids are generally understood to be fragments that were originally part of cores of differentiated planetesimals or part of local melt pools on primitive bodies. The parent bodies of iron meteorites may have formed in the terrestrial planet region, from which they were then scattered into the main belt (Bottke, W.F., Nesvorný, D., Grimm, R.E., Morbidelli, A., O'Brien, D.P. [2006]. Nature 439, 821-824). Therefore, a wide range of collisional events at different mass scales, temperatures, and impact velocities would have occurred between the time when the iron was segregated and the impact that eventually exposed the iron meteorites to interplanetary space. In this study, we performed impact disruption experiments of iron meteorite specimens as projectiles or targets at room temperature to increase understanding of the disruption process of iron bodies in near-Earth space. Our iron specimens (as projectiles or targets) were almost all smaller in size than their counterparts (as targets or projectiles, respectively). Experiments of impacts of steel specimens were also conducted for comparison. The fragment mass distribution of the iron material was different from that of rocks. In the iron fragmentation, a higher percentage of the mass was concentrated in larger fragments, probably due to the ductile nature of the material at room temperature. The largest fragment mass fraction f was dependent not only on the energy density but also on the size d of the specimen. We assumed a power-law dependence of the largest fragment mass fraction to initial peak pressure P0 normalized by a dynamic strength, Y, which was defined to be dependent on the size of the iron material. A least squares fit to the data of iron meteorite specimens resulted in the following relationship: f∝∝d, indicating a large size dependence of f. Additionally, the deformation of the iron materials in high-velocity shots was found to be most significant when the

  15. From laboratory manipulations to Earth system models: scaling calcification impacts of ocean acidification

    Directory of Open Access Journals (Sweden)

    J. R. Young

    2009-11-01

    Full Text Available The observed variation in the calcification responses of coccolithophores to changes in carbonate chemistry paints a highly incoherent picture, particularly for the most commonly cultured "species", Emiliania huxleyi. The disparity between magnitude and potentially even sign of the calcification change under simulated end-of-century ocean surface chemical changes (higher pCO2, lower pH and carbonate saturation, raises challenges to quantifying future carbon cycle impacts and feedbacks because it introduces significant uncertainty in parameterizations used for global models. Here we compile the results of coccolithophore carbonate chemistry manipulation experiments and review how ocean carbon cycle models have attempted to bridge the gap from experiments to global impacts. Although we can rule out methodological differences in how carbonate chemistry is altered as introducing an experimental bias, the absence of a consistent calcification response implies that model parameterizations based on small and differing subsets of experimental observations will lead to varying estimates for the global carbon cycle impacts of ocean acidification. We highlight two pertinent observations that might help: (1 the degree of coccolith calcification varies substantially, both between species and within species across different genotypes, and (2 the calcification response across mesocosm and shipboard incubations has so-far been found to be relatively consistent. By analogy to descriptions of plankton growth rate vs. temperature, such as the "Eppley curve", which seek to encapsulate the net community response via progressive assemblage change rather than the response of any single species, we posit that progressive future ocean acidification may drive a transition in dominance from more to less heavily calcified coccolithophores. Assemblage shift may be more important to integrated community calcification response than species

  16. Establishing a Ballistic Test Methodology for Documenting the Containment Capability of Small Gas Turbine Engine Compressors

    Science.gov (United States)

    Heady, Joel; Pereira, J. Michael; Ruggeri, Charles R.; Bobula, George A.

    2009-01-01

    A test methodology currently employed for large engines was extended to quantify the ballistic containment capability of a small turboshaft engine compressor case. The approach involved impacting the inside of a compressor case with a compressor blade. A gas gun propelled the blade into the case at energy levels representative of failed compressor blades. The test target was a full compressor case. The aft flange was rigidly attached to a test stand and the forward flange was attached to a main frame to provide accurate boundary conditions. A window machined in the case allowed the projectile to pass through and impact the case wall from the inside with the orientation, direction and speed that would occur in a blade-out event. High-peed, digital-video cameras provided accurate velocity and orientation data. Calibrated cameras and digital image correlation software generated full field displacement and strain information at the back side of the impact point.

  17. The usage of optical fibers for damage detection in ballistic protection composite laminates

    Directory of Open Access Journals (Sweden)

    Živković Irena D.

    2006-01-01

    Full Text Available This paper describes the procedure of embedding fiber optic sensors in laminar thermoplastic composite material, as well as damage investigation after ballistic loading. Thermoplastic-reinforced composite materials were made for increased material damage resistance during ballistic loading. Damage inside the composite material was detected by observing the intensity drop of the light signal transmitted through the optical fibers. Experimental testing was carried out in order to observe and analyze the response of the material under various load conditions. Different types of Kevlar reinforced composite materials (thermoplastic, thermo reactive and thermoplastic with ceramic plate as the impact face were made. Material damage resistance during ballistic loading was investigated and compared. Specimens were tested under multiple load conditions. The opto-electronic part of the measurement system consists of two light-emitting diodes as light sources for the optical fibers, and two photo detectors for the light intensity measurement. The output signal was acquired from photo detectors by means of a data acquisition board and personal computer. The measurements showed an intensity drop of the transmitted light signal as a result of the applied loading on composite structure for all the optical fibers. All the diagrams show similar behavior of the light signal intensity. In fact, all of them may be divided into three zones: the zone of penetration of the first composite layer, the bullet traveling zone through the composite material till its final stop, and the material relaxation zone. The attenuation of the light signal intensity during impact is caused by the influence of the applied dynamic stress on the embedded optical fibers. The applied stress caused micro bending of the optical fiber, changes in the shape of the cross-section and the unequal changes of the indices of refraction of the core and cladding due to the stress-optic effect. The

  18. Using modified ballistic limit equations in spacecraft risk assessments

    Science.gov (United States)

    Schonberg, William P.

    2016-09-01

    The fundamental components of any meteoroid/orbital debris (MOD) risk assessment calculation are environment models, damage response predictor equations, and failure criteria. In the case of a spacecraft operating in low earth orbit, the response predictor equation typically takes the form of a ballistic limit equation (BLE) that defines the threshold particle sizes that cause failure of a spacecraft wall or component. Spacecraft risk assessments often call for BLEs for spacecraft components that do not exist. In such cases, it is a common procedure to use an existing BLE after first equivalencing the actual materials and/or wall thicknesses to the materials that were used in the development of the existing BLE. The question naturally arises regarding how close are the predictions of such an 'adapted BLE' to the response characteristics of the actual materials/wall configurations under high speed projectile impacts. This paper presents the results of a study that compared the predictions of a commonly used BLE when adapted to the Soyuz OM wall configuration against those of a new BLE that was developed specifically for that Soyuz wall configuration. It was found that the critical projectile diameters predicted by the new Soyuz OM wall BLE can exceed those predicted by the adapted use of the existing BLE by as much as 50% of the existing BLE values. Thus, using the adapted version of the existing BLE in this particular case would contribute to a more conservative value of assessed risk. If the same trends were to hold true for other spacecraft wall configurations, then it is also possible that using existing BLEs, even after they have been adjusted for differences in materials, etc., may result in predictions of smaller critical diameters (i.e., increased assessed risk) than would using BLEs purposely developed for actual spacecraft configurations of interest.

  19. Irradiation damage in Gd2Ti2O7 single crystals: Ballistic versus ionization processes

    Science.gov (United States)

    Moll, S.; Sattonnay, G.; Thomé, L.; Jagielski, J.; Decorse, C.; Simon, P.; Monnet, I.; Weber, W. J.

    2011-08-01

    The structural transformations induced in Gd2Ti2O7 single crystals irradiated at high energies (870-MeV Xe), where ionization processes (electronic stopping) dominate, and at low energies (4-MeV Au), where ballistic processes (nuclear stopping) dominate, have been studied via the combination of Rutherford backscattering spectrometry and channeling (RBS/C), Raman spectroscopy, and transmission electron microscopy (TEM) experiments. At high energy, amorphization occurs directly in individual ion tracks from the extreme electronic-energy deposition, and full amorphization results from the overlapping of these tracks as described by a direct impact model. The track diameters lie in the range 6-9 nm. At low energy, amorphization occurs via indirect processes, driven by ballistic nuclear energy deposition from the ions, that is accounted for in the framework of both direct-impact/defect-stimulated and multi-step damage accumulation models. The ion fluence for total amorphization of the irradiated layer is much higher at low energy (0.5 ion nm-2) than at high energy (0.05 ion nm-2), consistent with the nuclear stopping at low energy (5.2 keV/nm) compared to the electronic stopping at high energy (29 keV/nm).

  20. Irradiation Damage in Gd2Ti2O7 Single Crystals: Ballistic vs Ionization Processes

    Energy Technology Data Exchange (ETDEWEB)

    Moll, Sandra [Pacific Northwest National Laboratory (PNNL); Sattonnay, Gael [Universite Paris Sud, Orsay, France; Thome, Lionel [Universite Paris Sud, Orsay, France; Jagielski, Jacek [Institute for Electronic Materials Technology; Decorse, C [Universite Paris Sud, Orsay, France; Simon, Patrick [CEMHTI-CNRS, Universite d' Orleans; Monnet, Isabelle [Grand Accelerateur National d' Ions Lourds (GANIL); Weber, William J [ORNL

    2011-01-01

    The structural transformations induced in Gd2Ti2O7 single crystals irradiated at high energies (870 MeV Xe), where ionization processes (electronic stopping) dominate, and at low energies (4 MeV Au), where ballistic processes (nuclear stopping) dominate, have been studied via the combination of Rutherford backscattering spectrometry and channeling, Raman spectroscopy and transmission electron microscopy experiments. At high energy, amorphization occurs directly in individual ion tracks from the extreme electronic energy deposition from ionization, and full amorphization results from the overlapping of these tracks as described by a direct impact model. The track diameters determined from RBS/C and TEM data lie in the range 6-8 nm. At low energy, amorphization occurs via indirect processes, driven by ballistic nuclear energy deposition from the ions, that is accounted for in the framework of both the direct-impact/defect stimulated and multi-step damage accumulation models. The ion fluence for total amorphization of the irradiated layer is much higher (0.5 ion nm-2) at low energy than at high energy (0.05 ion nm-2), consistent with the nuclear stopping at low energy (5.2 keV/nm) compared to the electronic stopping at high energy (29 keV/nm).

  1. Emerging Rapid Resistance Testing Methods for Clinical Microbiology Laboratories and Their Potential Impact on Patient Management

    Directory of Open Access Journals (Sweden)

    Hagen Frickmann

    2014-01-01

    Full Text Available Atypical and multidrug resistance, especially ESBL and carbapenemase expressing Enterobacteriaceae, is globally spreading. Therefore, it becomes increasingly difficult to achieve therapeutic success by calculated antibiotic therapy. Consequently, rapid antibiotic resistance testing is essential. Various molecular and mass spectrometry-based approaches have been introduced in diagnostic microbiology to speed up the providing of reliable resistance data. PCR- and sequencing-based approaches are the most expensive but the most frequently applied modes of testing, suitable for the detection of resistance genes even from primary material. Next generation sequencing, based either on assessment of allelic single nucleotide polymorphisms or on the detection of nonubiquitous resistance mechanisms might allow for sequence-based bacterial resistance testing comparable to viral resistance testing on the long term. Fluorescence in situ hybridization (FISH, based on specific binding of fluorescence-labeled oligonucleotide probes, provides a less expensive molecular bridging technique. It is particularly useful for detection of resistance mechanisms based on mutations in ribosomal RNA. Approaches based on MALDI-TOF-MS, alone or in combination with molecular techniques, like PCR/electrospray ionization MS or minisequencing provide the fastest resistance results from pure colonies or even primary samples with a growing number of protocols. This review details the various approaches of rapid resistance testing, their pros and cons, and their potential use for the diagnostic laboratory.

  2. Laboratory study on the ecological impact of sophorolipid used for harmful algae elimination

    Science.gov (United States)

    Sun, Xiaoxia; Kim, Eunki; Sun, Song

    2010-11-01

    We studied the role of sophorolipid in inhibiting harmful algae bloom (HAB). Different sophorolipid concentrations were tested on marine microalgae, zooplankton, fish, and bivalve ( Mytilus edulis) in laboratory. The result shows that sophorolipid could inhibit the growth of algal species selectively. Among three algae species selected, Platymonas helgolandica var. tsingtaoensis was promoted with increasing sophorolipid concentration; Isochrysis galbana was inhibited seven days later in sophorolipid concentration below 40 mg/L; and Nitzschia closterium f. minutissima was inhibited obviously in only a high sophorolipid concentration over 20 mg/L. Therefore, sophorolipid in a low concentration at Artemia salina was 600 mg/L. The relative clearance rate of mussel Mytilus edulis decreased to 80%, 40%, and 20% of the control group after being exposed to 20, 50, and 100 mg/L sophorolipid for 24 h. Therefore, the toxicity for mitigation of harmful algae bloom at previously recommended concentration of 5-20 mg/L sophorolipid is low for most tested organisms in this reaserch.

  3. The potentials of porous concrete for ballistic protection

    NARCIS (Netherlands)

    Weerheijm, J.; Roebroeks, G.; Krabbenborg, D.; Agar Ozbek, A.S.

    2015-01-01

    A special porous concrete has been developed by the Delft University in collaboration with TNO. The concrete has a static compressive strength of 45 MPa. It fragments at impact into small size debris relative to reference concrete. The porous concrete was developed at laboratory scale and tested at

  4. The potentials of porous concrete for ballistic protection

    NARCIS (Netherlands)

    Weerheijm, J.; Roebroeks, G.; Krabbenborg, D.; Agar Ozbek, A.S.

    2015-01-01

    A special porous concrete has been developed by the Delft University in collaboration with TNO. The concrete has a static compressive strength of 45 MPa. It fragments at impact into small size debris relative to reference concrete. The porous concrete was developed at laboratory scale and tested at

  5. Ballistic missile precession frequency extraction by spectrogram's texture

    Science.gov (United States)

    Wu, Longlong; Xu, Shiyou; Li, Gang; Chen, Zengping

    2013-10-01

    In order to extract precession frequency, an crucial parameter in ballistic target recognition, which reflected the kinematical characteristics as well as structural and mass distribution features, we developed a dynamic RCS signal model for a conical ballistic missile warhead, with a log-norm multiplicative noise, substituting the familiar additive noise, derived formulas of micro-Doppler induced by precession motion, and analyzed time-varying micro-Doppler features utilizing time-frequency transforms, extracted precession frequency by measuring the spectrogram's texture, verified them by computer simulation studies. Simulation demonstrates the excellent performance of the method proposed in extracting the precession frequency, especially in the case of low SNR.

  6. Advanced Computer Science on Internal Ballistics of Solid Rocket Motors

    Science.gov (United States)

    Shimada, Toru; Kato, Kazushige; Sekino, Nobuhiro; Tsuboi, Nobuyuki; Seike, Yoshio; Fukunaga, Mihoko; Daimon, Yu; Hasegawa, Hiroshi; Asakawa, Hiroya

    In this paper, described is the development of a numerical simulation system, what we call “Advanced Computer Science on SRM Internal Ballistics (ACSSIB)”, for the purpose of improvement of performance and reliability of solid rocket motors (SRM). The ACSSIB system is consisting of a casting simulation code of solid propellant slurry, correlation database of local burning-rate of cured propellant in terms of local slurry flow characteristics, and a numerical code for the internal ballistics of SRM, as well as relevant hardware. This paper describes mainly the objectives, the contents of this R&D, and the output of the fiscal year of 2008.

  7. Internal Ballistics of High Velocity Special Purpose Guns

    Directory of Open Access Journals (Sweden)

    V. K. Gupta

    1976-07-01

    Full Text Available More and more conventional guns are being utilized as special purpose guns to achieve very high velocity by using unconventionally high C/W ratios. The existing methods of internal ballistics give satisfactory results only for low (less than one C/W ratios. In the present paper the basic internal ballistic equations have been modified to cater for non-linear rate of burning, cubical form function and a realistic pressure gradient between breech face and the projectile base. The equations have been numerically solved. The results for low and high C/W ratios have been compared with those obtained by using conventional methods.

  8. Geometrical optimization of a local ballistic magnetic sensor

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, Yuhsuke; Hara, Masahiro [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Nomura, Tatsuya [Advanced Electronics Research Division, INAMORI Frontier Research Center, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Kimura, Takashi [Advanced Electronics Research Division, INAMORI Frontier Research Center, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan)

    2014-04-07

    We have developed a highly sensitive local magnetic sensor by using a ballistic transport property in a two-dimensional conductor. A semiclassical simulation reveals that the sensitivity increases when the geometry of the sensor and the spatial distribution of the local field are optimized. We have also experimentally demonstrated a clear observation of a magnetization process in a permalloy dot whose size is much smaller than the size of an optimized ballistic magnetic sensor fabricated from a GaAs/AlGaAs two-dimensional electron gas.

  9. Low-Energy Ballistic Transfers to Lunar Halo Orbits

    Science.gov (United States)

    Parker, Jeffrey S.

    2009-01-01

    Recent lunar missions have begun to take advantage of the benefits of low-energy ballistic transfers between the Earth and the Moon rather than implementing conventional Hohmann-like lunar transfers. Both Artemis and GRAIL plan to implement low-energy lunar transfers in the next few years. This paper explores the characteristics and potential applications of many different families of low-energy ballistic lunar transfers. The transfers presented here begin from a wide variety of different orbits at the Earth and follow several different distinct pathways to the Moon. This paper characterizes these pathways to identify desirable low-energy lunar transfers for future lunar missions.

  10. Secondary electron emission from lunar soil by solar wind type ion impact: Laboratory measurements

    Science.gov (United States)

    Dukes, Catherine; Bu, Caixia; Baragiola, Raul A.

    2015-11-01

    Introduction: The lunar surface potential is determined by time-varying fluxes of electrons and ions from the solar wind, photoelectrons ejected by UV photons, cosmic rays, and micrometeorite impacts. Solar wind ions have a dual role in the charging process, adding positive charge to the lunar regolith upon impact and ejecting negative secondary electrons (SE). Electron emission occurs when the energy from the impacting ion is transferred to the solid, ionizing and damaging the material; electrons with kinetic energy greater than the ionization potential (band gap + electron affinity) are ejected from the solid[1].Experiment: We investigate the energy distribution of secondary electrons ejected from Apollo soils of varying maturity and lunar analogs by 4 keV He+. Soils are placed into a shallow Al cup and compressed. In-situ low-energy oxygen plasma is used to clean atmospheric contaminants from the soil before analysis[2]. X-ray photoelectron spectroscopy ascertains that the sample surface is clean. Experiments are conducted in a PHI 560 system (mirror electron energy analyzer (CMA) and μ-metal shield. The spectrometer is used to measure SE distributions, as well as for in situ surface characterization. A small negative bias (~5V) with respect to the grounded entrance grid of the CMA may be placed on the sample holder in order to expose the low energy cutoff.To measure SE energy distributions, primary ions rastered over a ~6 x 6 mm2 area are incident on the sample at ~40° relative to the surface normal, while SE emitted with an angle of 42.3°± 3.5° in a cone are analyzed.Results: The energy distribution of SE ejected from 4 keV He ion irradiation of albite with no bias applied shows positive charging of the surface. The general shape and distribution peak (~4 eV) are consistent with spectra for low energy ions on insulating material[1].Acknowledgements: We thank the NASA LASER program for support.References: [1]P. Riccardi, R. Baragiola et al. (2004); Surf

  11. Terminal Performance of Lead-Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video

    CERN Document Server

    Courtney, Elijah; Andrusiv, Lubov; Courtney, Michael

    2016-01-01

    Due to concerns about environmental and industrial hazards of lead, a number of military, law enforcement, and wildlife management agencies are giving careful consideration to lead-free ammunition. The goal of lead-free bullets is to gain the advantages of reduced lead use in the environment while maintaining equal or better terminal performance. Accepting reduced terminal performance would foolishly risk the lives of military and law enforcement personnel. This paper uses the established technique of studying bullet impacts in ballistic gelatin to characterize the terminal performance of eight commercial off-the- shelf lead-free handgun bullets for comparison with earlier analysis of jacketed lead bullets. Peak retarding force and energy deposit in calibrated ballistic gelatin are quantified using high speed video. The temporary stretch cavities and permanent wound cavities are also characterized. Two factors tend to reduce the terminal performance of these lead-free projectiles compared to similar jacketed ...

  12. Impact of an Advanced Cardiac Life Support Simulation Laboratory Experience on Pharmacy Student Confidence and Knowledge.

    Science.gov (United States)

    Maxwell, Whitney D; Mohorn, Phillip L; Haney, Jason S; Phillips, Cynthia M; Lu, Z Kevin; Clark, Kimberly; Corboy, Alex; Ragucci, Kelly R

    2016-10-25

    Objective. To assess the impact of an advanced cardiac life support (ACLS) simulation on pharmacy student confidence and knowledge. Design. Third-year pharmacy students participated in a simulation experience that consisted of team roles training, high-fidelity ACLS simulations, and debriefing. Students completed a pre/postsimulation confidence and knowledge assessment. Assessment. Overall, student knowledge assessment scores and student confidence scores improved significantly. Student confidence and knowledge changes from baseline were not significantly correlated. Conversely, a significant, weak positive correlation between presimulation studying and both presimulation confidence and presimulation knowledge was discovered. Conclusions. Overall, student confidence and knowledge assessment scores in ACLS significantly improved from baseline; however, student confidence and knowledge were not significantly correlated.

  13. The impact of different blood sampling methods on laboratory rats under different types of anaesthesia

    DEFF Research Database (Denmark)

    Toft, Martin Fitzner; Petersen, Mikke Haxø; Dragsted, Nils

    2006-01-01

    for rats sampled from the tail vein, which showed fluctuations in body temperature in excess of 30 h after sampling. Increases in heart rate and blood pressure within the first hours after sampling indicated that periorbital puncture was the method that had the largest acute impact on the rats......Rats with implanted telemetry transponders were blood sampled by jugular puncture, periorbital puncture or tail vein puncture, or sampled by jugular puncture in carbon dioxide (CO?), isoflurane or without anaesthesia in a crossover design. Heart rate, blood pressure and body temperature were...... registered for three days after sampling. Initially blood pressure increased, but shortly after sampling it decreased, which led to increased heart rate. Sampling induced rapid fluctuations in body temperature, and an increase in body temperature. Generally, rats recovered from sampling within 2-3 h, except...

  14. Using a ballistic-caprock model for developing a volcanic projectiles hazard map at Santorini caldera

    Science.gov (United States)

    Konstantinou, Konstantinos

    2015-04-01

    Volcanic Ballistic Projectiles (VBPs) are rock/magma fragments of variable size that are ejected from active vents during explosive eruptions. VBPs follow almost parabolic trajectories that are influenced by gravity and drag forces before they reach their impact point on the Earth's surface. Owing to their high temperature and kinetic energies, VBPs can potentially cause human casualties, severe damage to buildings as well as trigger fires. Since the Minoan eruption the Santorini caldera has produced several smaller (VEI = 2-3) vulcanian eruptions, the last of which occurred in 1950, while in 2011 it also experienced significant deformation/seismicity even though no eruption eventually occurred. In this work, an eruptive model appropriate for vulcanian eruptions is used to estimate initial conditions (ejection height, velocity) for VBPs assuming a broad range of gas concentration/overpressure in the vent. These initial conditions are then inserted into a ballistic model for the purpose of calculating the maximum range of VBPs for different VBP sizes (0.35-3 m), varying drag coefficient as a function of VBP speed and varying air density as a function of altitude. In agreement with previous studies a zone of reduced drag is also included in the ballistic calculations that is determined based on the size of vents that were active in the Kameni islands during previous eruptions (< 1 km). Results show that the horizontal range of VBPs varies between 0.9-3 km and greatly depends on gas concentration, the extent of the reduced drag zone and the size of VBP. Hazard maps are then constructed by taking into account the maximum horizontal range values as well as potential locations of eruptive vents along a NE-SW direction around the Kameni islands (the so-called "Kameni line").

  15. Vent development during the Minoan eruption (1640 BC) of Santorini, Greece, as suggested by ballistic blocks

    Science.gov (United States)

    Pfeiffer, T.

    2001-05-01

    The Minoan eruption on Santorini, Greece, was a major Plinian caldera-forming event that occurred at ca. 1640 BC. The eruption is generally divided into four distinct phases: (1) Plinian phase; (2) phreatomagmatic base-surge; (3) ash-flow phase; and (4) non-welded ignimbrite. Many ballistic blocks, mostly consisting of older lava-fragments with diameters up to several meters, were ejected during phases 2 and 3. As caldera collapse followed the eruption, the precise vent location is unknown, but its position during phase 1 has been inferred from the pumice isopachs of the Plinian deposits. The location of the vent during the following phases has been estimated by measuring thickness variations, flow directions within the pyroclastic flows and impact directions of ballistic blocks. In this study, the vent location has been estimated by analysis of the size distribution of the ballistic blocks. Phase 2 blocks show no clear size-dependant distribution pattern. Blocks ranging between 0.15 and 1.60 m in diameter are found throughout almost the entire deposit, but are concentrated in the southeastern parts and within a circle of 14 km diameter, thus suggesting a maximum range of at least 6-7 km. The center of that circle is regarded as the most probable ejection region. It is proposed that the subaerial vent of phase 1 developed into an fracture opening to the SW along the general tectonic trend. Very large blocks, up to 3 m in diameter (or possibly more) were also ejected during phase 3, with the largest ones being found only in the northern half of the island group near the caldera rim. It therefore appears that at least one other vent opened in the northern half of the caldera, possibly as a new SW-NE-trending fracture.

  16. Physiological and Pathological Impact of Blood Sampling by Retro-Bulbar Sinus Puncture and Facial Vein Phlebotomy in Laboratory Mice

    DEFF Research Database (Denmark)

    Teilmann, Anne Charlotte; Nygaard Madsen, Andreas; Holst, Birgitte

    2014-01-01

    Retro-bulbar sinus puncture and facial vein phlebotomy are two widely used methods for blood sampling in laboratory mice. However, the animal welfare implications associated with these techniques are currently debated, and the possible physiological and pathological implications of blood sampling...... using these methods have been sparsely investigated. Therefore, this study was conducted to assess and compare the impacts of blood sampling by retro-bulbar sinus puncture and facial vein phlebotomy. Blood was obtained from either the retro-bulbar sinus or the facial vein from male C57BL/6J mice at two...... time points, and the samples were analyzed for plasma corticosterone. Body weights were measured at the day of blood sampling and the day after blood sampling, and the food consumption was recorded automatically during the 24 hours post-procedure. At the end of study, cheeks and orbital regions were...

  17. Historical milestones in measurement of HDL-cholesterol: impact on clinical and laboratory practice.

    Science.gov (United States)

    Langlois, Michel R; Blaton, Victor H

    2006-07-23

    High-density lipoprotein cholesterol (HDL-C) comprises a family of particles with differing physicochemical characteristics. Continuing progress in improving HDL-C analysis has originated from two separate fields-one clinical, reflecting increased attention to HDL-C in estimating risk for coronary heart disease (CHD), and the other analytical, reflecting increased emphasis on finding more reliable and cost-effective HDL-C assays. Epidemiologic and prospective studies established the inverse association of HDL-C with CHD risk, a relationship that is consistent with protective mechanisms demonstrated in basic research and animal studies. Atheroprotective and less atheroprotective HDL subpopulations have been described. Guidelines on primary and secondary CHD prevention, which increased the workload in clinical laboratories, have led to a revolution in HDL-C assay technology. Many analytical techniques including ultracentrifugation, electrophoresis, chromatography, and polyanion precipitation methods have been developed to separate and quantify HDL-C and HDL subclasses. More recently developed homogeneous assays enable direct measurement of HDL-C on an automated analyzer, without the need for manual pretreatment to separate non-HDL. Although homogeneous assays show improved accuracy and precision in normal serum, discrepant results exist in samples with atypical lipoprotein characteristics. Hypertriglyceridemia and monoclonal paraproteins are important interfering factors. A novel approach is nuclear magnetic resonance spectroscopy that allows rapid and reliable analysis of lipoprotein subclasses, which may improve the identification of individuals at increased CHD risk. Apolipoprotein A-I, the major protein of HDL, has been proposed as an alternative cardioprotective marker avoiding the analytical limitations of HDL-C.

  18. Impact of trace metal concentrations on coccolithophore growth and morphology: laboratory simulations of Cretaceous stress

    Directory of Open Access Journals (Sweden)

    G. Faucher

    2017-07-01

    Full Text Available The Cretaceous ocean witnessed intervals of profound perturbations such as volcanic input of large amounts of CO2, anoxia, eutrophication and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a few calcareous nannofossil species. The correspondence between intervals of high trace metal concentrations and coccolith dwarfism suggests a negative effect of these elements on nannoplankton biocalcification processes in past oceans. In order to test this hypothesis, we explored the potential effect of a mixture of trace metals on growth and morphology of four living coccolithophore species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The phylogenetic history of coccolithophores shows that the selected living species are linked to Mesozoic species showing dwarfism under excess metal concentrations. The trace metals tested were chosen to simulate the environmental stress identified in the geological record and upon known trace metal interactions with living coccolithophore algae.Our laboratory experiments demonstrated that elevated trace metal concentrations, similarly to the fossil record, affect coccolithophore algae size and/or weight. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccoliths of G. oceanica showed a decrease in size only at the highest trace metal concentrations. P. carterae coccolith size was unresponsive to changing trace metal concentrations. These differences among species allow discriminating the most- (P. carterae, intermediate- (E. huxleyi and G. oceanica and least-tolerant (C. pelagicus taxa. The fossil record and the experimental results converge on a selective response of coccolithophores to metal availability.These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions.

  19. Impact of trace metal concentrations on coccolithophore growth and morphology: laboratory simulations of Cretaceous stress

    Science.gov (United States)

    Faucher, Giulia; Hoffmann, Linn; Bach, Lennart T.; Bottini, Cinzia; Erba, Elisabetta; Riebesell, Ulf

    2017-07-01

    The Cretaceous ocean witnessed intervals of profound perturbations such as volcanic input of large amounts of CO2, anoxia, eutrophication and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a few calcareous nannofossil species. The correspondence between intervals of high trace metal concentrations and coccolith dwarfism suggests a negative effect of these elements on nannoplankton biocalcification processes in past oceans. In order to test this hypothesis, we explored the potential effect of a mixture of trace metals on growth and morphology of four living coccolithophore species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The phylogenetic history of coccolithophores shows that the selected living species are linked to Mesozoic species showing dwarfism under excess metal concentrations. The trace metals tested were chosen to simulate the environmental stress identified in the geological record and upon known trace metal interactions with living coccolithophore algae.Our laboratory experiments demonstrated that elevated trace metal concentrations, similarly to the fossil record, affect coccolithophore algae size and/or weight. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccoliths of G. oceanica showed a decrease in size only at the highest trace metal concentrations. P. carterae coccolith size was unresponsive to changing trace metal concentrations. These differences among species allow discriminating the most- (P. carterae), intermediate- (E. huxleyi and G. oceanica) and least-tolerant (C. pelagicus) taxa. The fossil record and the experimental results converge on a selective response of coccolithophores to metal availability.These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions.

  20. HELIUM-POWERED BALLISTIC TEST APPARATUS

    Data.gov (United States)

    Federal Laboratory Consortium — This research device is used for the initial assessment of new materials and is primarily used for fragmentation testing of yarns, fabric, or laminate samples. The...

  1. HELIUM-POWERED BALLISTIC TEST APPARATUS

    Data.gov (United States)

    Federal Laboratory Consortium — This research device is used for the initial assessment of new materials and is primarily used for fragmentation testing of yarns, fabric, or laminate samples. The...

  2. Physical Mechanisms of Soft Tissue Injury from Penetrating Ballistic Impact

    Science.gov (United States)

    2012-11-30

    2008; 64(6):1420-1426. 18. Gryth D, Rocksen D, Persson JK, Arborelius UP, Drobin D, Bursell J, Olsson LG, Kjellstrom BT. Severe lung contusion and...elastic tissues such as lungs and muscle, where the tissue tends to spring back into place with little damage from temporary stretch, most tissue...in a study comparing penetrating thoracic wounds caused by stab injuries to those caused by gunshot injuries, the occurrence of lung

  3. Ballistic Missile Defense System (BMDS) Programmatic Environmental Impact Statement

    Science.gov (United States)

    2007-01-01

    for decommissioning the BMDS to prot(lct the Uruted ~tatoo lU.~.J . ns depbyed forces . friends. and aUlas hom b~Uistic missile throats. The...intcr~contincmal balh:. tic 7) The President would, m reaffirm the entire L’l’- de\\’cl<I•Pmcn:, human rigl:ts ~;caic. leader the ratitlcatlon...aspi."Ct’< oft he Balli~ tic Miss1k DetCnsc (BMD) pwgrarn. Acid rain; The MDA ihcl:·noti..’S i:1 the ?EIS the pn:.sibility cfa..:id rain cuuseC

  4. Numerical Simulation of Ballistic Impact of Layered Aluminum Nitride Ceramic

    Science.gov (United States)

    2015-09-01

    configuration simulated in this work duplicates that examined in experiments of Yadav and Ravichandran.1 As shown in Fig. 1a, a WHA (tungsten heavy alloy... WHA ) 157 c aJohnson GR, Holmquist TJ, Beissel SR. Response of aluminum nitride (including a phase change) to large strains, high strain rates, and...results cannot be isolated in the present set of simulations, but possibilities include the following: the WHA material may be weaker than that

  5. Ballistic Missile Defense Final Programmatic Environmental Impact Statement

    Science.gov (United States)

    2008-02-15

    vU.o1.. anO U.S.A. amidO wall Me, re 1.4e ha, re Tao1l, Soy, Rualsan OsagploO USA big ~ ~ ~~ s _._ hwdm.Pn:aNtoniasl Security Aomioor, gAnriayLakeis 001...System Safety Program Requirements Military Standard 882A is intended to ensure that a safety program that stresses hazard identification and

  6. Methods for Analysis and Simulation of Ballistic Impact

    Science.gov (United States)

    2017-04-01

    shape factor that has a value of unity for continuous jets and a value of two for dispersed particle jets: I( − )N = ON ⇒ JR SR = V...be seeded a priori along such pending failure surfaces. Cleavage fracture on specific planes can also be depicted [110]. Extremely fine meshes are

  7. Environment Impact Analysis Process. Small Intercontinental Ballistic Missile Program

    Science.gov (United States)

    1986-03-01

    OF INVESTIGATION: Regional Growth, and Associated Demands on Housing, Public Services, and Public Finance DISCUSSION: The potential deployment areas...AREAS OF INVESTIGATION: Regional Growth, and Associated Demands on Housing,a Public Services, and Public Finance DISCUSSION: The potential deployment...Housing, Public Services, and Public Finance DISCUSSION: The potential deployment areas for southern Nevada are dispersed over a four-county region

  8. Legislative Environmental Impact Statement: Small Intercontinental Ballistic Missile Program.

    Science.gov (United States)

    1986-11-01

    east from San Luis , Arizona to about Dos Cabezas, Arizona (Figure 3.9.3-1). Quaternary faulting in extreme southeast Arizona is dominated by north...Orr, and R. Gary Roybal 1981 Water Resources of the Rincon and Mesilla Valleys and Adjacent Areas, New Mexico. New Mexico State Engineer Office

  9. Impact of antigenic diversity on laboratory diagnosis of Avian bornavirus infections in birds.

    Science.gov (United States)

    Zimmermann, Vanessa; Rinder, Monika; Kaspers, Bernd; Staeheli, Peter; Rubbenstroth, Dennis

    2014-11-01

    Avian bornaviruses (ABVs) are a group of genetically diverse viruses within the Bornaviridae family that can infect numerous avian species and represent the causative agents of proventricular dilatation disease, an often fatal disease that is widely distributed in captive populations of parrots and related species. The current study was designed to assess the antigenic variability of the family Bornaviridae and to determine its impact on ABV diagnosis by employing fluorescent antibody assays. It was shown that polyclonal rabbit sera directed against recombinant bornavirus nucleoprotein, X protein, phosphoprotein, and matrix protein provided sufficient cross-reactivity for the detection of viral antigen from a broad range of bornavirus genotypes grown in cell culture. In contrast, a rabbit anti-glycoprotein serum and 2 monoclonal antibodies directed against nucleoprotein and phosphoprotein proteins reacted more specifically. Antibodies were readily detected in sera from avian patients infected with known ABV genotypes if cells persistently infected with a variety of different bornavirus genotypes were used for analysis. For all sera, calculated antibody titers were highest when the homologous or a closely related target virus was used for the assay. Cross-reactivity with more distantly related genotypes of other phylogenetic groups was usually reduced, resulting in titer reduction of up to 3 log units. The presented results contribute to a better understanding of the antigenic diversity of family Bornaviridae and further emphasize the importance of choosing appropriate diagnostic tools for sensitive detection of ABV infections. © 2014 The Author(s).

  10. Measuring the impact of an instructional laboratory on the learning of introductory physics

    CERN Document Server

    Wieman, Carl

    2015-01-01

    We have analyzed the impact of taking an associated lab course on the scores on final exam questions in two large introductory physics courses. Approximately a third of the students who completed each course also took an accompanying instructional lab course. The lab courses were fairly conventional, although they focused on supporting the mastery of a subset of the introductory physics topics covered in the associated course. Performance between students who did and did not take the lab course was compared using final exam questions from the associated courses that related to concepts from the lab courses. The population of students who took the lab in each case was somewhat different from those who did not enroll in the lab course in terms of background and major. Those differences were taken into account by normalizing their performance on the lab-related questions with scores on the exam questions that did not involve material covered in the lab. When normalized in this way, the average score on lab-relat...

  11. Understanding the health impacts of urbanization in China: A living laboratory for urban biogeochemistry research

    Science.gov (United States)

    Zhu, Y. G.

    2015-12-01

    China has the largest population in the world, and by 2011, more than 50% of its population are now living in cities. This ongoing societal change has profound impacts on environmental quality and population health. In addition to intensive discharges of waste, urbanization is not only changing the land use and land cover, but also inducing fundamental changes in biogeochemical processes. Unlike biogeochemistry in non-urban environment, the biological component of urban biogeochemistry is dominated by direct human activities, such as air pollution derived from transport, wastewater treatment, garbage disposal and increase in impervious surface etc. Managing urban biogeochemistry will include source control over waste discharge, eco-infrastructure (such as green space and eco-drainage), resource recovery from urban waste stream, and integration with peri-urban ecosystem, particularly with food production system. The overall goal of managing urban biogeochemistry is for human health and wellbeing, which is a global challenge. In this paper, the current status of urban biogeochemistry research in China will be briefly reviewed, and then it will focus on nutrient recycling and waste management, as these are the major driving forces of environmental quality changes in urban areas. This paper will take a holistic view on waste management, covering urban metabolism analysis, technological innovation and integration for resource recovery from urban waste stream, and risk management related to waste recycling and recovery.

  12. Laboratory investigations of the impact of mineral dust aerosol on cold cloud formation

    Science.gov (United States)

    Koehler, K. A.; Kreidenweis, S. M.; Demott, P. J.; Petters, M. D.; Prenni, A. J.; Möhler, O.

    2010-12-01

    Dust particles represent a dominant source of particulate matter (by mass) to the atmosphere, and their emission from some source regions has been shown to be transported on regional and hemispherical scales. Dust particles' potential to interact with water vapor in the atmosphere can lead to important radiative impacts on the climate system, both direct and indirect. We have investigated this interaction for several types of dust aerosol, collected from the Southwestern United States and the Saharan region. A continuous flow diffusion chamber was operated to measure the ice nucleation ability of the dust particles in the temperature range of relevance to cirrus and mixed-phase clouds (-65ICIS, 2007) which indicated that ice nucleation on larger, polydisperse dust particles occurs at warmer temperatures than found for the smaller particles. When particles were coated with secondary organic aerosol (SOA) species, higher relative humidity was required for ice nucleation below -40 °C, similar to that required for homogeneous nucleation of sulfates. However, ice nucleation was still observed on SOA-coated dust at warmer temperatures than are required for homogeneous nucleation of sulfates, indicating that condensation freezing occurs without any apparent deactivation for temperatures between -25 and -35 °C.

  13. The Impact of Hands-On Simulation Laboratories on Teaching of Wireless Communications

    Directory of Open Access Journals (Sweden)

    Te-Shun Chou

    2017-03-01

    Full Text Available Aim/Purpose: To prepare students with both theoretical knowledge and practical skills in the field of wireless communications. Background: Teaching wireless communications and networking is not an easy task because it involves broad subjects and abstract content. Methodology: A pedagogical method that combined lectures, labs, assignments, exams, and readings was applied in a course of wireless communications. Contribution: Five wireless networking labs, related to wireless local networks, wireless security, and wireless sensor networks, were developed for students to complete all of the required hands-on lab activities. Findings: Both development and implementation of the labs achieved a successful outcome and provided students with a very effective learning experience. Students expressed that they had a better understanding of different wireless network technologies after finishing the labs. Recommendations for Practitioners: Detailed instructional lab manuals should be developed so that students can carry out hands-on activities in a step-by-step fashion. Recommendation for Researchers: Hands-on lab exercises can not only help students understand the abstract technical terms in a meaningful way, but also provide them with hands-on learning experience in terms of wireless network configuration, implementation, and evaluation. Impact on Society: With the help of a wireless network simulator, students have successfully enhanced their practical skills and it would benefit them should they decide to pursue a career in wireless network design or implementation. Future Research: Continuous revision of the labs will be made according to the feedback from students. Based on the experience, more wireless networking labs and network issues could be studied in the future.

  14. Impact of aerosol composition and foliage characteristics on forest canopy deposition rates: A laboratory study

    Science.gov (United States)

    Hornsby, K. E.; Pryor, S. C.

    2013-12-01

    concentrations using a Licor LI-7000 and dew point (Buck Research Instruments model CR-1A). A suite of experiments was conducted in which the; (i) Aerosol particle composition was varied (4 chemical compounds) (ii) Aerosol particle GMD was varied (40-80 nm) (iii) Aerosol particle total number concentration was varied (2 orders of magnitude) (iv) Tree type was varied (using a range of species and alternately lacquering the trees to prevent active uptake) (v) Light, water vapor content and CO2 concentrations inside the chamber were varied in order to mimic the range of conditions observed at our experimental particle flux site in southern Indiana (see related abstract by Pryor and Hornsby that describes the in situ flux estimates). The results of these laboratory experiments are used to quantify the relative importance of these factors in dictating aerosol particle uptake and specifically the importance of the foliage collection mechanisms at the leaf scale and deposition flux partitioning between foliage and non-foliage elements.

  15. Optimal control of the ballistic motion of Airy beams.

    Science.gov (United States)

    Hu, Yi; Zhang, Peng; Lou, Cibo; Huang, Simon; Xu, Jingjun; Chen, Zhigang

    2010-07-01

    We demonstrate the projectile motion of two-dimensional truncated Airy beams in a general ballistic trajectory with controllable range and height. We show that the peak beam intensity can be delivered to any desired location along the trajectory as well as repositioned to a given target after displacement due to propagation through disordered or turbulent media.

  16. Special case of the elastic collision and the ballistic pendulum

    Science.gov (United States)

    Schröer, H.

    We want to investigate some interesting cases at the elastic collision. We view the ballistic pendulum. A bullet is fired from a gun or pistol. This mass collides inelastic with the mass at the pendulum. We get an expression for the bullet's velocity.

  17. The application of computed tomography in wound ballistics research

    Science.gov (United States)

    Tsiatis, Nick; Moraitis, Konstantinos; Papadodima, Stavroula; Spiliopoulou, Chara; Kelekis, Alexis; Kelesis, Christos; Efstathopoulos, Efstathios; Kordolaimi, Sofia; Ploussi, Agapi

    2015-09-01

    In wound ballistics research there is a relationship between the data that characterize a bullet and the injury resulted after shooting when it perforates the human body. The bullet path in the human body following skin perforation as well as the damaging effect cannot always be predictable as they depend on various factors such as the bullet's characteristics (velocity, distance, type of firearm and so on) and the tissue types that the bullet passes through. The purpose of this presentation is to highlight the contribution of Computed Tomography (CT) in wound ballistics research. Using CT technology and studying virtual “slices” of specific areas on scanned human bodies, allows the evaluation of density and thickness of the skin, the subcutaneous tissue, the muscles, the vital organs and the bones. Density data taken from Hounsfield units can be converted in g/ml by using the appropriate software. By evaluating the results of this study, the anatomy of the human body utilizing ballistic gel will be reproduced in order to simulate the path that a bullet follows. The biophysical analysis in wound ballistics provides another application of CT technology, which is commonly used for diagnostic and therapeutic purposes in various medical disciplines.

  18. Models of Ballistic Propagation of Heat at Low Temperatures

    Science.gov (United States)

    Kovács, R.; Ván, P.

    2016-09-01

    Heat conduction at low temperatures shows several effects that cannot be described by the Fourier law. In this paper, the performance of various theories is compared in case of wave-like and ballistic propagation of heat pulses in NaF.

  19. On the Trajectories of Projectiles Depicted in Early Ballistic Woodcuts

    Science.gov (United States)

    Stewart, Sean M.

    2012-01-01

    Motivated by quaint woodcut depictions often found in many late 16th and 17th century ballistic manuals of cannonballs fired in air, a comparison of their shapes with those calculated for the classic case of a projectile moving in a linear resisting medium is made. In considering the asymmetrical nature of such trajectories, the initial launch…

  20. Gate controlled high efficiency ballistic energy conversion system

    NARCIS (Netherlands)

    Xie, Yanbo; Bos, Diederik; de Boer, Hans L.; van den Berg, Albert; Eijkel, Jan C.T.; Zengerle, R.

    2013-01-01

    Last year we demonstrated the microjet ballistic energy conversion system[1]. Here we show that the efficiency of such a system can be further improved by gate control. With gate control the electrical current generation is enhanced a hundred times with respect to the current generated from the zeta

  1. Interference in ballistic motor learning - is motor interference really sensory?

    DEFF Research Database (Denmark)

    Lundbye-Jensen, Jesper; Petersen, Tue Hvass; Rothwell, John C

    learned a ballistic ankle plantarflexion task. Interference was observed following subsequent learning of a precision tracking task with the same movement direction and agonist muscles, but not by learning involving the opposite movement and antagonist muscles or by voluntary agonist contractions that did...

  2. Magneto-ballistic transport in GaN nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Santoruvo, Giovanni, E-mail: giovanni.santoruvo@epfl.ch; Allain, Adrien; Ovchinnikov, Dmitry; Matioli, Elison, E-mail: elison.matioli@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), CH 1015 Lausanne (Switzerland)

    2016-09-05

    The ballistic filtering property of nanoscale crosses was used to investigate the effect of perpendicular magnetic fields on the ballistic transport of electrons on wide band-gap GaN heterostructures. The straight scattering-less trajectory of electrons was modified by a perpendicular magnetic field which produced a strong non-linear behavior in the measured output voltage of the ballistic filters and allowed the observation of semi-classical and quantum effects, such as quenching of the Hall resistance and manifestation of the last plateau, in excellent agreement with the theoretical predictions. A large measured phase coherence length of 190 nm allowed the observation of universal quantum fluctuations and weak localization of electrons due to quantum interference up to ∼25 K. This work also reveals the prospect of wide band-gap GaN semiconductors as a platform for basic transport and quantum studies, whose properties allow the investigation of ballistic transport and quantum phenomena at much larger voltages and temperatures than in other semiconductors.

  3. Phase conjugated Andreev backscattering in two-dimensional ballistic cavities

    NARCIS (Netherlands)

    Morpurgo, A.F.; Holl, S.; Wees, B.J.van; Klapwijk, T.M; Borghs, G.

    1997-01-01

    We have experimentally investigated transport in two-dimensional ballistic cavities connected to a point contact and to two superconducting electrodes with a tunable macroscopic phase difference. The point contact resistance oscillates as a function of the phase difference in a way which reflects

  4. An investigation of the impact of selected prereading activities on student content learning through laboratory activities

    Science.gov (United States)

    Kass, Jesse (Shaya)

    This study investigated whether two prereading activities impacted student learning from hands-on science activities. The study was based on constructivist learning theory. Based on the work of Piaget, it was hypothesized that students who activated prior knowledge would learn more from the activities. Based on the work of Vygotsky it was hypothesized that students who talk more and write more would learn more from the activity. The K-W-L chart and anticipation guide strategies were used with eighth grade students at Graves Middle School in Whittier, California before learning about levers and convection currents. D. M. Ogle (1986) created the three-column K-W-L chart to have students activate prior knowledge. In the first column, the students write what they already know about a subject, in the second column, the students write what they want to know about the subject, and the students complete the third column after learning about a subject by writing answers to the questions that they asked in the second column. Duffelmeyer (1994) created the anticipation guide based on Herber's (1978) reasoning guide. In the anticipation guide, the teacher creates three or four sentences that convey the major ideas of the topic and the students either agree or disagree with the statements. After learning about the topic, students revisit their answers and decide if they were correct or incorrect and they must defend their choices. This research used the Solomon (1947) four-square design and compared both the experimental groups to a control group that simply discussed the concepts before completing the activity. The research showed no significant difference between the control group and either of the treatment groups. The reasons for the lack of significant differences are considered. It was hypothesized that since the students were unfamiliar with the prereading activities and did not have much experience with using either writing-to-learn or talking-to-learn strategies, the

  5. Signs of muscle thixotropy during human ballistic wrist joint movements.

    Science.gov (United States)

    Axelson, H W

    2005-11-01

    A study was conducted on healthy subjects to determine whether voluntary ballistic wrist flexion movements are influenced by immediately preceding conditioning of the forearm muscles. Single rapid wrist flexion movements were made in response to an auditory "Go" signal. Rectified surface EMG was recorded from wrist flexors and extensors, and joint position was measured by a goniometer. The movements were preceded (2-3 s) by four different conditioning routines: 40-s rest (Rest), 10-s voluntary alternating wrist joint flexion and extension movements (Osc), and 10 s of 25 degrees weak isometric wrist extensor (Ext) or flexor contractions (Flex). When subjects made ballistic movements after Osc compared with Rest, peak velocity was higher (P = 0.02) and movement time shorter (P = 0.06), but there was no difference (P = 0.83) in motor reaction time (time between the onset of the first agonist burst and movement onset). If the movements were preceded by Ext compared with Flex, motor reaction time was longer (P = 0.01), indicating a longer electromechanical delay. There were no indications that postconditioning differences in agonist or antagonist muscle activity could explain the results. It was also demonstrated that, after Rest, peak velocity was lower (P < 0.01) for the first than for the second of a series of repetitive ballistic movements. The observations corresponded to results from passive experiments in which the median nerve was electrically stimulated. In conclusion, history-dependent (thixotropic) changes in skeletal muscle resistance seem to have implications for voluntary ballistic wrist movements. The study also provided evidence that muscle conditioning influences the central nervous reaction time preceding ballistic contractions.

  6. Ballistic parameters and trauma potential of pistol crossbows.

    Science.gov (United States)

    Frank, Matthias; Schikorr, Wolfgang; Tesch, Ralf; Werner, Ronald; Hanisch, Steffen; Peters, Dieter; Ekkernkamp, Axel; Bockholdt, Britta; Seifert, Julia

    2013-07-01

    Hand-held pistol crossbows, which are smaller versions of conventional crossbows, have recently increased in popularity. Similar to conventional crossbows, life threatening injuries due to bolts discharged from pistol crossbows are reported in forensic and traumatological literature. While the ballistic background of conventional crossbows is comprehensively investigated, there are no investigations on the characteristic ballistic parameters (draw force, potential energy, recurve factor, kinetic energy, and efficiency) of pistol crossbows. Two hand-held pistol crossbows (Barnett Commando and Mini Cross Bow, rated draw force 362.9 N or 80 lbs) were tested. The maximum draw force was investigated using a dynamic tensile testing machine (TIRAtest 2705, TIRA GmbH). The potential energy was determined graphically by polynomial regression as area under the force-draw curve. External ballistic parameters of the bolts discharged from pistol crossbows were measured using a redundant ballistic speed measurement system (Dual-BMC 21a and Dual-LS 1000, Werner Mehl Kurzzeitmesstechnik). The average maximum draw force was 190.3 and 175.6 N for the Barnett and Mini Cross Bow, respectively. The corresponding total energy expended was 10.7 and 11 J, respectively. The recurve factor was calculated to be 0.705 and 1.044, respectively. Average bolt velocity was measured 43 up to 52 m/s. The efficiency was calculated up to 0.94. To conclude, this work provides the pending ballistic data on this special subgroup of crossbows which operate on a remarkable low kinetic energy level. Furthermore, it demonstrates that the nominal draw force pretended in the sales brochure is grossly exaggerated.

  7. Ballistic Performance of Coconut Shell Powder/Twaron Fabricagainst Non-armour Piercing Projectiles

    Directory of Open Access Journals (Sweden)

    M.S. Risby

    2008-03-01

    Full Text Available Body armour technologists over the years are seeking to develop protective systems whichare both effective and lightweight. However these hard armour materials are very expensive andhave certain weight constraints. From this point of view, natural fibres and fillers have attractedthe attention of researchers due to their low density with high specific strengths, abundance,availability, renewability and being environmental-friendly. This paper reports the potential useof coconut shell powder-epoxy composite (COEX panel bonded with Twaron CT716 fabric asa hard armour material and the characteristics of its fracture imprints from a specific threat levelwhen subjected to ballistic tests1 (NIJ Standard 0108.01. It was observed that the imprint patternson the particulate composite (COEX could be identified according to effectiveness in impactenergy dissipation. COEX/Twaron test panel was found to withstand impact equivalent to NIJLevel IIIA using 9 mm FMJ ammunition but perforated at NIJ Level III of 7.62 mm FMJ bulletimpacts. Test results showed that COEX panel do possess shock absorbance characteristics andcan be utilised as  an armour component in the hard-body armour system. Dependency onTwaron fabric layers as ballistic reinforcements has been reduced up to 3-time with 170 per centimprovement on energy-absorption capabilities when using COEX composite as the frontalcomponent of the armour.

  8. Study on ballistic penetration resistance of titanium alloy TC4, Part Ⅱ: Numerical analysis

    Institute of Scientific and Technical Information of China (English)

    Zhang Tao; Chen Wei; Guan Yupu; Gao Deping; Li Shuguang

    2013-01-01

    Enhancing containment capability and reducing weight are always great concerns in the design of casings.Ballistic tests can help to mitigate a catastrophic event after a blade out,yet taking time and costing money.A wise way is to hunt for a validated numerical simulation technology,through which the material dynamic behavior over the strain rate range in the ballistic tests should be represented and reasonable failure strain should be defined.The simulation results show that the validation of the numerical simulation technology based on the test data can accurately estimate the absorption energy,describe the physical process and failure mode during the penetration,as well as the failure mechanism.It is found that energy dissipation of projectiles is in manner of compression stage,energy conversion stage,and interactive scrap stage.An effect indicator is proposed,where the factors of critical velocity including impact orientation and mass of projectiles and thickness of casings are considered.The critical velocity presents a linear relation with the effect indicator,which implies the critical velocity obtained by the flat casing could underestimate the capability of the real casing.

  9. Ballistic tongue projection in chameleons maintains high performance at low temperature.

    Science.gov (United States)

    Anderson, Christopher V; Deban, Stephen M

    2010-03-23

    Environmental temperature impacts the physical activity and ecology of ectothermic animals through its effects on muscle contractile physiology. Sprinting, swimming, and jumping performance of ectotherms decreases by at least 33% over a 10 degrees C drop, accompanied by a similar decline in muscle power. We propose that ballistic movements that are powered by recoil of elastic tissues are less thermally dependent than movements that rely on direct muscular power. We found that an elastically powered movement, ballistic tongue projection in chameleons, maintains high performance over a 20 degrees C range. Peak velocity and power decline by only 10%-19% with a 10 degrees C drop, compared to >42% for nonelastic, muscle-powered tongue retraction. These results indicate that the elastic recoil mechanism circumvents the constraints that low temperature imposes on muscle rate properties and thereby reduces the thermal dependence of tongue projection. We propose that organisms that use elastic recoil mechanisms for ecologically important movements such as feeding and locomotion may benefit from an expanded thermal niche.

  10. Erodibility of Titan ice bedrock constrained by laboratory measurements of ice strength and erosion by sediment impacts

    Science.gov (United States)

    Sklar, L. S.; Collins, G. C.; Litwin, K. L.; Polito, P. J.; Zygielbaum, B. R.

    2012-12-01

    Saturn's moon Titan has a remarkably earth-like surface morphology, with branching fluvial networks draining elevated terrain. A paucity of impact craters suggests fluvial dissection is active and that the pace of landscape evolution is rapid. A key limitation on modeling rates of incision by Titan's rivers of liquid methane has been a lack of information on the erodibility of water-ice bedrock at ultra-cold temperatures. Here we report results from laboratory measurements of ice resistance to tensile fracture and rates of erosion of Titan bedrock analogs by low-velocity sediment impacts. We apply these experimental results to modeling fluvial incision, and explore constraints on rates and frequency of channel cutting on Titan. We made test samples of polycrystalline ice with a narrow and wide size distribution of seed ice grains. For some samples we added solid impurities composed of basalt, urea, and ammonium-sulfate, to account for the possibility that Titan's ice bedrock also contains silicates from meteors, organic polymers derived from Titan's atmosphere, and ammonia-based compounds formed by cryovolcanism. The experiments were conducted in a walk-in freezer and environmental chamber, where we varied temperature between 260 and 110 K using dry ice and liquid nitrogen (LN). For terrestrial rocks, resistance to erosion by sediment impacts depends on the kinetic energy required to detach a unit volume, which has been shown to scale with the square of tensile strength. We measured the tensile strength of Titan bedrock analogs using the Brazilian splitting test and found that strength increases with decreasing temperature at 7 kPa/K, for all ice types tested. Ice at Titan temperatures is thus roughly twice as strong as at terrestrial conditions; ice is strengthened by increasing impurity concentrations, finer grain-size distributions, and lower porosity. To replicate erosion of ice bedrock by bedload sediment impacts, we filled a 55-gallon drum with various ice

  11. The effect of high-pressure devitrification and densification on ballistic-penetration resistance of fused silica

    Science.gov (United States)

    Avuthu, Vasudeva Reddy

    Despite the clear benefits offered by more advanced transparent materials, (e.g. transparent ceramics offer a very attractive combination of high stiffness and high hardness levels, highly-ductile transparent polymers provide superior fragment-containing capabilities, etc.), ballistic ceramic-glass like fused-silica remains an important constituent material in a majority of transparent impact-resistant structures (e.g. windshields and windows of military vehicles, portholes in ships, ground vehicles and spacecraft) used today. Among the main reasons for the wide-scale use of glass, the following three are most frequently cited: (i) glass-structure fabrication technologies enable the production of curved, large surface-area, transparent structures with thickness approaching several inches; (ii) relatively low material and manufacturing costs; and (iii) compositional modifications, chemical strengthening, and controlled crystallization have been demonstrated to be capable of significantly improving the ballistic properties of glass. In the present work, the potential of high-pressure devitrification and densification of fused-silica as a ballistic-resistance-enhancement mechanism is investigated computationally. In the first part of the present work, all-atom molecular-level computations are carried out to infer the dynamic response and material microstructure/topology changes of fused silica subjected to ballistic impact by a nanometer-sized hard projectile. The analysis was focused on the investigation of specific aspects of the dynamic response and of the microstructural changes such as the deformation of highly sheared and densified regions, and the conversion of amorphous fused silica to SiO2 crystalline allotropic modifications (in particular, alpha-quartz and stishovite). The microstructural changes in question were determined by carrying out a post-processing atom-coordination procedure. This procedure suggested the formation of high-density stishovite (and

  12. Evaluation of a Belt-Cast Austenitic Steel Alloy from Salzgitter Mannesmann Forschung: Effect of Hardness on the Ballistic Resistance against Two 0.30-cal. Projectile Types

    Science.gov (United States)

    2017-08-01

    ARL-TR-8080 ● AUG 2017 US Army Research Laboratory Evaluation of a Belt-Cast Austenitic Steel Alloy from Salzgitter Mannesmann...of a Belt-Cast Austenitic Steel Alloy from Salzgitter Mannesmann Forschung: Effect of Hardness on the Ballistic Resistance against Two 0.30-cal...provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently

  13. Cross-Laboratory Comparative Study of the Impact of Experimental and Regression Methodologies on Salmonella Thermal Inactivation Parameters in Ground Beef.

    Science.gov (United States)

    Hildebrandt, Ian M; Marks, Bradley P; Juneja, Vijay K; Osoria, Marangeli; Hall, Nicole O; Ryser, Elliot T

    2016-07-01

    Isothermal inactivation studies are commonly used to quantify thermal inactivation kinetics of bacteria. Meta-analyses and comparisons utilizing results from multiple sources have revealed large variations in reported thermal resistance parameters for Salmonella, even when in similar food materials. Different laboratory or regression methodologies likely are the source of methodology-specific artifacts influencing the estimated parameters; however, such effects have not been quantified. The objective of this study was to evaluate the effects of laboratory and regression methodologies on thermal inactivation data generation, interpretation, modeling, and inherent error, based on data generated in two independent laboratories. The overall experimental design consisted of a cross-laboratory comparison using two independent laboratories (Michigan State University and U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center [ERRC] laboratories), both conducting isothermal Salmonella inactivation studies (55, 60, 62°C) in ground beef, and each using two methodologies reported in prior studies. Two primary models (log-linear and Weibull) with one secondary model (Bigelow) were fitted to the resultant data using three regression methodologies (two two-step regressions and a one-step regression). Results indicated that laboratory methodology impacted the estimated D60°C- and z-values (α = 0.05), with the ERRC methodology yielding parameter estimates ∼25% larger than the Michigan State University methodology, regardless of the laboratory. Regression methodology also impacted the model and parameter error estimates. Two-step regressions yielded root mean square error values on average 40% larger than the one-step regressions. The Akaike Information Criterion indicated the Weibull as the more correct model in most cases; however, caution should be used to confirm model robustness in application to real-world data. Overall, the

  14. The Effect of Temperature and Nanoclay on the Low Velocity and Ballistic Behavior of Woven Glass-Fiber Reinforced Composites

    Science.gov (United States)

    Patrin, Lauren

    The objective of this research was to study the effect of nanoclay and temperature on the behavior of woven glass-fabric reinforced epoxy composite under low velocity and ballistic impacts. The materials used in manufacturing the composite were S2 (6181) glass-fibers, epoxy resin (EPON 828), hardener (Epikure 3230), nanoclay and Heloxy 61 modifier. The nanoclay addition was 0%, 1%, 3% and 5% by weight, with respect to the resin. All specimens were manufactured at the City College facilities using vacuum infusion. Tensile tests were conducted to characterize the material and obtain the Young's modulus, ultimate stress, failure strain, Poisson's ratio, shear modulus and shear strength and their variation with nanoclay percentage and temperature. The tests were conducted at room temperature (21°C/70°F), -54°C (-65°F), -20°C (-4°F), 49°C (120°F) and 71°C (160°F). Next composite specimens with 0%, 1%, 3% and 5% nanoclay by weight, with respect to the resin, were subjected to low velocity impact at the previously specified temperatures to determine dynamic force, displacement and energy correlations. The extent of damage was studied using the ultrasound technique. Then ballistic tests were conducted on the nanoclay infused specimens at room temperature to obtain the ballistic limit (V50) and the damage behavior of the composite. The dynamic finite element analysis (FEA) software LS-DYNA was used to model and simulate the results of low velocity impact tests. Good agreement was obtained between experimental and numerical (FEA) results. Analytical analyses were undertaken to compare the results from the tensile experiments. The finite element analysis (FEA) allowed for further analytical comparison of the results. The FEA platform used was LS-DYNA due to its proficient dynamic and damage capabilities in composite materials. The FEA was used to model and simulate the low velocity impacts and compare the results to experiments.

  15. Impact of Chloramination on the Development of Laboratory-Grown Biofilms Fed with Filter-Pretreated Groundwater

    KAUST Repository

    Ling, Fangqiong

    2013-01-01

    This study evaluated the continuous impact of monochloramine disinfection on laboratory-grown biofilms through the characterization of biofilm architecture and microbial community structure. Biofilm development and disinfection were achieved using CDC (Centers for Disease Control and Prevention) biofilm reactor systems with polyvinyl chloride (PVC) coupons as the substratum and sand filter-pretreated groundwater as the source of microbial seeding and growth nutrient. After 2 weeks of growth, the biofilms were subjected to chloramination for 8 more weeks at concentrations of 7.5±1.4 to 9.1±0.4 mg Cl2 L-1. Control reactors received no disinfection during the development of biofilms. Confocal laser scanning microscopy and image analysis indicated that chloramination could lead to 81.4-83.5% and 86.3-95.6% reduction in biofilm biomass and thickness, respectively, but could not eliminate biofilm growth. 16S rRNA gene terminal restriction fragment length polymorphism analysis indicated that microbial community structures between chloraminated and non-chloraminated biofilms exhibited different successional trends. 16S rRNA gene pyrosequencing analysis further revealed that chloramination could select members of Actinobacteria and Acidobacteria as the dominant populations, whereas natural development leads to the selection of members of Nitrospira and Bacteroidetes as dominant biofilm populations. Overall, chloramination treatment could alter the growth of multi-species biofilms on the PVC surface, shape the biofilm architecture, and select a certain microbial community that can survive or proliferate under chloramination.

  16. THE IMPACT OF WASHING ON THE EFICACY OF (DELTAMETHRIN "LONG LASTING IMPREGNATED BED NET" IN THE LABORATORY

    Directory of Open Access Journals (Sweden)

    Damar Tri Boewono

    2012-11-01

    Full Text Available A study was conducted to evaluate the impact of washing on the decrease in the effectiveness of the Long Lasting Impregnated Bed Net = IBN (deltamethrin at a dosage of 55 mg/m2 on polyester 100%. The study was conducted by bioassay test on a sample 20 x 20 cm2 (untreated mosquito net, in the laboratory of the IBN (deltamethin and a control bed net (20 x 20 cm2; using malaria vectors Anophelesmaculatus and Anopheles aconitus. The bioassay test was conducted every day (4 replicates with 10-15 mosquitoes/cone. The test was conducted until a mortality of 70% was reached. The exposure time was 3 minutes (recording knockdown mosquitoes, holding for 24 hours and counting the dead mosquitoes after 24 hours. Before the next bioassay test, the bed net sample was washed 3 times using 3 gram solid/hardsoap, and shaken on a shaker. Results show that the residual effect of the IBN decrease slowly after washing which has lost its effectiveness after 45 washings (Mortality< 70%. 

  17. Impact Testing on Reinforced Carbon-Carbon Flat Panels with Ice Projectiles for the Space Shuttle Return to Flight Program

    Science.gov (United States)

    Melis, Matthew E.; Revilock, Duane M.; Pereira, Michael J.; Lyle, Karen H.

    2009-01-01

    Following the tragedy of the Orbiter Columbia (STS-107) on February 1, 2003, a major effort commenced to develop a better understanding of debris impacts and their effect on the space shuttle subsystems. An initiative to develop and validate physics-based computer models to predict damage from such impacts was a fundamental component of this effort. To develop the models it was necessary to physically characterize reinforced carbon-carbon (RCC) along with ice and foam debris materials, which could shed on ascent and impact the orbiter RCC leading edges. The validated models enabled the launch system community to use the impact analysis software LS-DYNA (Livermore Software Technology Corp.) to predict damage by potential and actual impact events on the orbiter leading edge and nose cap thermal protection systems. Validation of the material models was done through a three-level approach: Level 1--fundamental tests to obtain independent static and dynamic constitutive model properties of materials of interest, Level 2--subcomponent impact tests to provide highly controlled impact test data for the correlation and validation of the models, and Level 3--full-scale orbiter leading-edge impact tests to establish the final level of confidence for the analysis methodology. This report discusses the Level 2 test program conducted in the NASA Glenn Research Center (GRC) Ballistic Impact Laboratory with ice projectile impact tests on flat RCC panels, and presents the data observed. The Level 2 testing consisted of 54 impact tests in the NASA GRC Ballistic Impact Laboratory on 6- by 6-in. and 6- by 12-in. flat plates of RCC and evaluated three types of debris projectiles: Single-crystal, polycrystal, and "soft" ice. These impact tests helped determine the level of damage generated in the RCC flat plates by each projectile and validated the use of the ice and RCC models for use in LS-DYNA.

  18. Slime mould logical gates: exploring ballistic approach

    CERN Document Server

    Adamatzky, Andrew

    2010-01-01

    Plasmodium of \\emph{Physarum polycephalum} is a single cell visible by unaided eye. On a non-nutrient substrate the plasmodium propagates as a traveling localization, as a compact wave-fragment of protoplasm. The plasmodium-localization travels in its originally predetermined direction for a substantial period of time even when no gradient of chemo-attractants is present. We utilize this property of \\emph{Physarum} localizations to design a two-input two-output Boolean logic gates $ \\to $ and $ \\to $. We verify the designs in laboratory experiments and computer simulations. We cascade the logical gates into one-bit half-adder and simulate its functionality.

  19. 26th International Symposium on Ballistics

    Science.gov (United States)

    2011-09-16

    Rainald Lohner 12075 - Capability Improvements for Modeling Fragment Impact in ALE3D Dr. Lara D. Leininger , USA; Sarah Minkoff, Dr. Robert Dorgan...295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 H Q R Dr. Lara Leininger

  20. A ballistic gate-tunable contact junction in graphene

    Science.gov (United States)

    Wilmart, Quentin; Rosticher, Michael; Boukhicha, Mohamed; Inhofer, Andreas; Morfin, Pascal; Feve, Gwendal; Berroir, Jean-Marc; Placais, Bernard; Equipe de Physique Mésoscopique Team

    2015-03-01

    Field-effect control of carrier is very efficient in graphene and allows controlling the doping profile with a great accuracy and high spatial resolution. This is needed if one wants to implement Dirac fermion optics experiments or simply to improve the performance of graphene devices. In this work we realize graphene transistors equipped with a set of local back-gates that provide control of local electric fields in the 108 V / m range at the 10 nanometer scale. In particular we demonstrate ballistic contact junctions using transistors with independent channel and contact back-gates. We shall discuss the possibilities offered by this technology for ballistic electronic and opto-electronic applications.

  1. The Ballistic Pressure Wave Theory of Handgun Bullet Incapacitation

    CERN Document Server

    Courtney, Michael

    2008-01-01

    This paper presents a summary of seven distinct chains of evidence, which, taken together, provide compelling support for the theory that a ballistic pressure wave radiating outward from the penetrating projectile can contribute to wounding and incapacitating effects of handgun bullets. These chains of evidence include the fluid percussion model of traumatic brain injury, observations of remote ballistic pressure wave injury in animal models, observations of rapid incapacitation highly correlated with pressure magnitude in animal models, epidemiological data from human shootings showing that the probability of incapacitation increases with peak pressure magnitude, case studies in humans showing remote pressure wave damage in the brain and spinal cord, and observations of blast waves causing remote brain injury.

  2. Possible influences on bullet trajectory deflection in ballistic gelatine.

    Science.gov (United States)

    Riva, Fabiano; Kerkhoff, Wim; Bolck, Annabel; Mattijssen, Erwin J A T

    2017-02-01

    The influence of the distance to the top and bottom of a gelatine block and to bullet tracks from previously fired shots on a bullet's trajectory, when passing through ballistic gelatine, was studied. No significant difference in deflection was found when trajectories of 9mm Luger bullets, fired at a 3.5cm distance to the top and bottom of a gelatine block and to bullet tracks from previously fired shots, were compared to trajectories of bullets fired 7cm or more away from any of the aforementioned aspects. A surprisingly consistent 6.5° absolute deflection angle was found when these bullets passed through 22.5 to 23.5cm of ballistic gelatine. The projection angle, determined by the direction of the deflection, appeared to be random. The consistent absolute angle, in combination with the random projection angle, resulted in a cone-like deflection pattern.

  3. Slow collisions in the ballistic pendulum: A computational study

    Science.gov (United States)

    Donnelly, Denis; Diamond, Joshua B.

    2003-06-01

    We study the ballistic pendulum in a situation that is not usually considered where the bullet shot into a hanging block requires a finite time (the collision time) to come to rest relative to the block. During this time the block undergoes a non-negligible displacement. A slow collision is one for which the block's displacement during the collision time is an appreciable fraction of its maximum displacement. For slow collisions, the quantitative results of our model differ significantly from the standard ballistic pendulum treatment. Suitably generalized momentum and energy relations are evaluated and provide a check on the numerical solutions. This work extends the treatment of a familiar problem and demonstrates the utility of computational tools accessible to undergraduates.

  4. Learning without knowing: subliminal visual feedback facilitates ballistic motor learning

    DEFF Research Database (Denmark)

    Lundbye-Jensen, Jesper; Leukel, Christian; Nielsen, Jens Bo

    During daily life we are constantly bombarded by sensory input providing information on the state of our body and the surrounding world. Although we do not consciously perceive all sensory inputs, these may nevertheless have consequences for our future behavior (e.g. Goodale and Milner...... was on the screen during learning. Despite of this, there was a significantly larger learning effect in the subliminal 13-26 ms group compared to the subliminal 0 ms group. In conclusion, the results demonstrate that in addition to supraliminal feedback, subliminal feedback, which was not consciously perceived...... by the learner, indeed facilitated ballistic motor learning. This effect likely relates to multiple (conscious versus unconscious) processing of visual feedback and to the specific neural circuitries involved in optimization of ballistic motor performance....

  5. Ballistic Missile Warhead Recognition based on Micro-Doppler Frequency

    Directory of Open Access Journals (Sweden)

    Sun Hui-Xia

    2008-11-01

    Full Text Available To elucidate the spinning-precession signatures of ballistic warhead, the model of spinning precessionfor ballistic missile warhead is established and the mathematics of micro-Doppler signatures caused by spinning-precession is derived. Then the micro-Doppler features are analysed using high-resolution time-frequencytransform, and the model predictions match the experimental data well. Based on  different mass of warheadsand decoys, the feature, which can reflect the mass of the targets, is extracted from the time-frequency plane,proving a new method for recognising warheads and discriminating these from decoys. Finally the validityof the feature extracted in this study is verified by computer simulations even with low signal-to-noise ratio.Defence Science Journal, 2008, 58(6, pp.705-709, DOI:http://dx.doi.org/10.14429/dsj.58.1697

  6. Ballistic annihilation with superimposed diffusion in one dimension.

    Science.gov (United States)

    Biswas, Soham; Larralde, Hernán; Leyvraz, Francois

    2016-02-01

    We consider a one-dimensional system with particles having either positive or negative velocity, and these particles annihilate on contact. Diffusion is superimposed on the ballistic motion of the particle. The annihilation may represent a reaction in which the two particles yield an inert species. This model has been the subject of previous work, in which it was shown that the particle concentration decays faster than either the purely ballistic or the purely diffusive case. We report on previously unnoticed behavior for large times when only one of the two species remains, and we also unravel the underlying fractal structure present in the system. We also consider in detail the case in which the initial concentration of right-going particles is 1/2+ɛ, with ɛ≠0. It is shown that remarkably rich behavior arises, in which two crossover times are observed as ɛ→0.

  7. Pseudomagnetic fields and ballistic transport in a suspended graphene sheet.

    Science.gov (United States)

    Fogler, M M; Guinea, F; Katsnelson, M I

    2008-11-28

    We study a suspended graphene sheet subject to the electric field of a gate underneath. We compute the elastic deformation of the sheet and the corresponding effective gauge field, which modifies the electronic transport. In a clean system the two-terminal conductance of the sample is reduced below the ballistic limit and is almost totally suppressed at low carrier concentrations in samples under tension. Residual disorder restores a small finite conductivity.

  8. Ballistics Modeling for Non-Axisymmetric Hypervelocity Smart Bullets

    Science.gov (United States)

    2014-06-03

    1DoD PETTT, Dynamics Research Corporation, Andover, MA; on-site at NRL. Railgun 67-6754-04 Ballistics Modeling for non-Axisymmetric Hypervelocity...report is concerned with calculating the trajectory of the projectile fired from an electromagnetic launcher, or railgun , which attains supersonic...at supersonic speeds [1]. In the case of a railgun , there is no requirement involving a casing or high pressure seal. Instead, there is a requirement

  9. System Architecture for Anti-Ship Ballistic Missile Defense (ASBMD)

    OpenAIRE

    Hobgood, Jean; Madison, Kimberly; Pawlowski, Geoffrey; Nedd, Steven.; Roberts, Michael; Rumberg, Paige

    2009-01-01

    Approved for public release; distribution is unlimited. Recent studies suggest that China is developing a new class of ballistic missiles that can be used against moving targets, such as ships. One such technology is anticipated to cover a range of 2,000 kilometers and operate at a speed of Mach 10. The threat is also capable of maneuvering both during the midcourse and terminal flight phases for the purposes of guidance, target acquisition, and countermeasures. This threat could greatl...

  10. Chaotic and ballistic dynamics in time-driven quasiperiodic lattices.

    Science.gov (United States)

    Wulf, Thomas; Schmelcher, Peter

    2016-04-01

    We investigate the nonequilibrium dynamics of classical particles in a driven quasiperiodic lattice based on the Fibonacci sequence. An intricate transient dynamics of extraordinarily long ballistic flights at distinct velocities is found. We argue how these transients are caused and can be understood by a hierarchy of block decompositions of the quasiperiodic lattice. A comparison to the cases of periodic and fully randomized lattices is performed.

  11. Development of a Two-Dimensional Implicit Interior Ballistics Code

    Science.gov (United States)

    1980-01-01

    the universal gas constant, W is the gas molecular weight, u m and n is the covolume factor, which is composition dependent . Following Gough (Ref...c is dependent on the gas composition but not temperature. v The static enthalpy is then h = p e + p The specific heat at constant pressure is...Gun Interior Ballistics Transient Combustion Time- dependent Adaptive Grid 20, ABST’RACT (Cazrt&au:e _. .. ._._ lliO 11 ~ llltld ldenllly by block

  12. Ballistic Thermal Transistor of Dielectric Four-terminal Nanostructures

    OpenAIRE

    Yang, Ping; Hu, Bambi

    2009-01-01

    We report a theoretical model for a thermal transistor in dielectric four-terminal nanostructures based on mesoscopic ballistic phonon transport, in which a steady thermal flow condition of system is obtained to set up the temperature field effect of gate. In the environment, thermal flow shows the transisting behaviors at low temperatures: saturation, asymmetry, and rectification. The phenomena can be explained reasonably by the nonlinear variation of the temperature dependence of propagatin...

  13. Going ballistic:dealing with guns, gangs and knives

    OpenAIRE

    2008-01-01

    Murders involving knives and firearms never fail to grab the headlines, yet they are relatively rare. Gun crime represents only 0.4% of all recorded crime in England and Wales. The public are often sceptical, however, when they read figures such as this – and they have reason to be so. Going Ballistic's findings support four primary arguments: that official crime figures do not reflect the experiences of many communities in England and Wales; that information and intelligence sharing between ...

  14. Theory of vortices in hybridized ballistic/diffusive-band superconductors

    Science.gov (United States)

    Tanaka, K.; Eschrig, M.; Agterberg, D. F.

    2007-06-01

    We study the electronic structure in the vicinity of a vortex in a two-band superconductor in which the quasiparticle motion is ballistic in one band and diffusive in the other. This study is based on a model appropriate for such a case, that we have introduced recently [Tanaka , Phys. Rev. B 73, 220501(R) (2006)]. We argue that in the two-band superconductor MgB2 , such a case is realized. Motivated by the experimental findings on MgB2 , we assume that superconductivity in the diffusive band is “weak,” i.e., mostly induced. We examine intriguing features of the order parameter, the current density, and the vortex core spectrum in the “strong” ballistic band under the influence of hybridization with the “weak” diffusive band. Although the order parameter in the diffusive band is induced, the characteristic length scales in the two bands differ due to Coulomb interactions. The current density in the vortex core is dominated by the contribution from the ballistic band, while outside the core the contribution from the diffusive band can be substantial, or even dominating. The current density in the diffusive band has strong temperature dependence, exhibiting the Kramer-Pesch effect when hybridization is strong. A particularly interesting feature of our model is the possibility of additional bound states near the gap edge in the ballistic band, that are prominent in the vortex center spectra. This contrasts with the single band case, where there is no gap-edge bound state in the vortex center. We find the above-mentioned unique features for parameter values relevant for MgB2 .

  15. Model of risk assessment under ballistic statistical tests

    Science.gov (United States)

    Gabrovski, Ivan; Karakaneva, Juliana

    The material presents the application of a mathematical method for risk assessment under statistical determination of the ballistic limits of the protection equipment. The authors have implemented a mathematical model based on Pierson's criteria. The software accomplishment of the model allows to evaluate the V50 indicator and to assess the statistical hypothesis' reliability. The results supply the specialists with information about the interval valuations of the probability determined during the testing process.

  16. Quadrennial Defense Review and Ballistic Missile Defense Review

    Science.gov (United States)

    2010-03-11

    global defense posture 3 BMDR Highlights • Outlines a strategy and policy framework to – Defend the homeland against limited ballistic missile attack...abroad – Collaborate closely with allies and partners – Pursue a cooperative and tailored global defense posture – Strengthen US civilian capacity...reviews in 2010 – QDR and BMDR released February 1, 2010 – Nuclear Posture Review to be released this spring – Space Posture Review, with Director of

  17. Pneumatic capillary gun for ballistic delivery of microparticles

    CERN Document Server

    Rinberg, D; Groisman, A; Rinberg, Dmitry; Simonnet, Claire; Groisman, Alex

    2005-01-01

    A pneumatic gun for ballistic delivery of microparticles to soft targets is proposed and demonstrated. The particles are accelerated by a high speed flow of Helium in a capillary tube. Vacuum suction applied to a concentric, larger diameter tube is used to completely divert the flow of Helium from the gun nozzle and prevent it from hitting the target. Depths of penetration of micron-sized gold particles into agarose gels and their speeds of ejection from the gun nozzle are measured.

  18. Ballistic anomalies in solid rocket motors due to migration effects

    Science.gov (United States)

    Pröbster, M.; Schmucker, R. H.

    Double base and composite propellants are generally used for rocket motors, whereby double base propellants basically consist of nitrocellulose plasticized with an explosive plasticizer, mostly nitroglycerine, and in some cases with an additional inert plasticizer and ballistic additives. Composite propellants consist of an oxidizer like ammonium perchlorate and of aluminum, binder and plasticizer and often contain liquid or solid burning rate catalysts. A common feature of both propellants is that they contain smaller or larger amounts of chemically unbonded liquid species which tend to migrate. If these propellants loose part of the plasticizer by migration into the insulation layer, not only will there be a change in mechanical propellant properties but also the bond between propellant and insulation may degrade. However, depending on the severity of these effects, the change in the ballistic properties of the propellant grain caused by plasticizer migration may be of even more importance. In the past, most emphasis was placed on the behaviour of end-burning configurations. However, more recent theoretical and experimental studies revealed that not only for end-burning grain configurations but also for internal burning configurations there is a common effect which is responsible for ballistic anomalies: migration of liquid species from the propellant into the insulation. By using a plasticizer equilibrated insulation in an internal burning configuration the liquid species migration and thus the previously observed ballistic anomalies are avoided. Using this approach for end-burning configurations provides similar positive results. The various factors affecting plasticizer migration are studied and discussed, and several methods to prevent liquid species migration are described as well as methods to obtain plasticizer resistant insulations.

  19. Chaotic and ballistic dynamics in time-driven quasiperiodic lattices

    CERN Document Server

    Wulf, Thomas

    2016-01-01

    We investigate the nonequilibrium dynamics of classical particles in a driven quasiperiodic lattice based on the Fibonacci sequence. An intricate transient dynamics of extraordinarily long ballistic flights at distinct velocities is found. We argue how these transients are caused and can be under- stood by a hierarchy of block decompositions of the quasiperiodic lattice. A comparison to the cases of periodic and fully randomized lattices is performed.

  20. Chaotic and ballistic dynamics in time-driven quasiperiodic lattices

    Science.gov (United States)

    Wulf, Thomas; Schmelcher, Peter

    2016-04-01

    We investigate the nonequilibrium dynamics of classical particles in a driven quasiperiodic lattice based on the Fibonacci sequence. An intricate transient dynamics of extraordinarily long ballistic flights at distinct velocities is found. We argue how these transients are caused and can be understood by a hierarchy of block decompositions of the quasiperiodic lattice. A comparison to the cases of periodic and fully randomized lattices is performed.

  1. Ballistic transport in InSb Josephson junctions

    Science.gov (United States)

    Damasco, John Jeffrey; Gill, Stephen; Car, Diana; Bakkers, Erik; Mason, Nadya

    We present transport measurements on Josephson junctions consisting of InSb nanowires contacted by Al at various junction lengths. Junction behavior as a function of gate voltage, electric field, and magnetic field is discussed. We show that short junctions behave as 1D quantum wires, exhibiting quantized conductance steps. In addition, we show how Josephson behavior changes as transport evolves from ballistic to diffusive as a function of contact spacing.

  2. Pivotal role of ballistic and quasi-ballistic electrons on LED efficiency

    Science.gov (United States)

    Ni, X.; Li, X.; Lee, J.; Liu, S.; Avrutin, V.; Matulionis, A.; Özgür, Ü.; Morkoç, H.

    2010-08-01

    Significant progress in the power conversion efficiency and brightness of InGaN-based light emitting diodes (LEDs) has paved the way for these devices to be considered for LED lighting. In this realm, however, the efficiency must be retained at high injection levels in order to generate the lumens required. Unfortunately, LEDs undergo a monotonic efficiency degradation starting at current densities even lower than 50 A/cm 2 which would hinder LED insertion into the general lighting market. The physical origins for the loss of efficiency retention are at present a topic of intense debate given its enormous implications. This paper reviews the current status of the field regarding the mechanisms that have been put forward as being responsible for the loss of efficiency, such as Auger recombination, electron overflow (spillover), current crowding, asymmetric injection of electrons and holes, and poor transport of holes through the active region, the last one being applicable to multiple quantum well designs. While the Auger recombination received early attention, increasing number of researchers seem to think otherwise at the moment in that it alone (if any) cannot explain the progressively worsening loss of efficiency reduction as the InN mole fraction is increased. Increasing number of reports seems to suggest that the electron overflow is one of the major causes of efficiency degradation. The physical driving force for this is likely to be the relatively poor hole concentration and transport, and skewed injection favoring electrons owing to their relatively high concentration. Most intriguingly there is recent experimental convincing evidence to suggest that quasi-ballistic electrons in the active region, which are not able to thermalize within the residence time and possibly longitudinal optical phonon lifetime, contribute to the carrier overflow which would require an entirely new thought process in the realm of LEDs.

  3. Excess of L-alanine in amino acids synthesized in a plasma torch generated by a hypervelocity meteorite impact reproduced in the laboratory

    Science.gov (United States)

    Managadze, George G.; Engel, Michael H.; Getty, Stephanie; Wurz, Peter; Brinckerhoff, William B.; Shokolov, Anatoly G.; Sholin, Gennady V.; Terent'ev, Sergey A.; Chumikov, Alexander E.; Skalkin, Alexander S.; Blank, Vladimir D.; Prokhorov, Vyacheslav M.; Managadze, Nina G.; Luchnikov, Konstantin A.

    2016-10-01

    We present a laboratory reproduction of hypervelocity impacts of a carbon containing meteorite on a mineral substance representative of planetary surfaces. The physical conditions of the resulting impact plasma torch provide favorable conditions for abiogenic synthesis of protein amino acids: We identified glycine and alanine, and in smaller quantities serine, in the produced material. Moreover, we observe breaking of alanine mirror symmetry with L excess, which coincides with the bioorganic world. Therefore the selection of L-amino acids for the formation of proteins for living matter could have been the result from plasma processes occurring during the impact meteorites on the surface. This indicates that the plasma torch from meteorite impacts could play an important role in the formation of biomolecular homochirality. Thus, meteorite impacts possibly were the initial stage of this process and promoted conditions for the emergence of a living matter.

  4. New Diagnostic, Launch and Model Control Techniques in the NASA Ames HFFAF Ballistic Range

    Science.gov (United States)

    Bogdanoff, David W.

    2012-01-01

    This report presents new diagnostic, launch and model control techniques used in the NASA Ames HFFAF ballistic range. High speed movies were used to view the sabot separation process and the passage of the model through the model splap paper. Cavities in the rear of the sabot, to catch the muzzle blast of the gun, were used to control sabot finger separation angles and distances. Inserts were installed in the powder chamber to greatly reduce the ullage volume (empty space) in the chamber. This resulted in much more complete and repeatable combustion of the powder and hence, in much more repeatable muzzle velocities. Sheets of paper or cardstock, impacting one half of the model, were used to control the amplitudes of the model pitch oscillations.

  5. Quantum ballistic evolution in quantum mechanics application to quantum computers

    CERN Document Server

    Benioff, P

    1996-01-01

    Quantum computers are important examples of processes whose evolution can be described in terms of iterations of single step operators or their adjoints. Based on this, Hamiltonian evolution of processes with associated step operators T is investigated here. The main limitation of this paper is to processes which evolve quantum ballistically, i.e. motion restricted to a collection of nonintersecting or distinct paths on an arbitrary basis. The main goal of this paper is proof of a theorem which gives necessary and sufficient conditions that T must satisfy so that there exists a Hamiltonian description of quantum ballistic evolution for the process, namely, that T is a partial isometry and is orthogonality preserving and stable on some basis. Simple examples of quantum ballistic evolution for quantum Turing machines with one and with more than one type of elementary step are discussed. It is seen that for nondeterministic machines the basis set can be quite complex with much entanglement present. It is also pr...

  6. Experimental model for civilian ballistic brain injury biomechanics quantification.

    Science.gov (United States)

    Zhang, Jiangyue; Yoganandan, Narayan; Pintar, Frank A; Guan, Yabo; Gennarelli, Thomas A

    2007-01-01

    Biomechanical quantification of projectile penetration using experimental head models can enhance the understanding of civilian ballistic brain injury and advance treatment. Two of the most commonly used handgun projectiles (25-cal, 275 m/s and 9 mm, 395 m/s) were discharged to spherical head models with gelatin and Sylgard simulants. Four ballistic pressure transducers recorded temporal pressure distributions at 308kHz, and temporal cavity dynamics were captured at 20,000 frames/second (fps) using high-speed digital video images. Pressures ranged from 644.6 to -92.8 kPa. Entry pressures in gelatin models were higher than exit pressures, whereas in Sylgard models entry pressures were lower or equivalent to exit pressures. Gelatin responded with brittle-type failure, while Sylgard demonstrated a ductile pattern through formation of micro-bubbles along projectile path. Temporary cavities in Sylgard models were 1.5-2x larger than gelatin models. Pressures in Sylgard models were more sensitive to projectile velocity and diameter increase, indicating Sylgard was more rate sensitive than gelatin. Based on failure patterns and brain tissue rate-sensitive characteristics, Sylgard was found to be an appropriate simulant. Compared with spherical projectile data, full-metal jacket (FMJ) projectiles produced different temporary cavity and pressures, demonstrating shape effects. Models using Sylgard gel and FMJ projectiles are appropriate to enhance understanding and mechanisms of ballistic brain injury.

  7. Evaluation of bone surrogates for indirect and direct ballistic fractures.

    Science.gov (United States)

    Bir, Cynthia; Andrecovich, Chris; DeMaio, Marlene; Dougherty, Paul J

    2016-04-01

    The mechanism of injury for fractures to long bones has been studied for both direct ballistic loading as well as indirect. However, the majority of these studies have been conducted on both post-mortem human subjects (PMHS) and animal surrogates which have constraints in terms of storage, preparation and testing. The identification of a validated bone surrogate for use in forensic, medical and engineering testing would provide the ability to investigate ballistic loading without these constraints. Two specific bone surrogates, Sawbones and Synbone, were evaluated in comparison to PMHS for both direct and indirect ballistic loading. For the direct loading, the mean velocity to produce fracture was 121 ± 19 m/s for the PMHS, which was statistically different from the Sawbones (140 ± 7 m/s) and Synbone (146 ± 3 m/s). The average distance to fracture in the indirect loading was .70 cm for the PMHS. The Synbone had a statistically similar average distance to fracture (.61 cm, p=0.54) however the Sawbones average distance to fracture was statistically different (.41 cm, pballistic testing was not identified and future work is warranted.

  8. Trial by Dutch laboratories for evaluation of non‐invasive prenatal testing. Part I—clinical impact

    Science.gov (United States)

    Oepkes, Dick; Page‐Christiaens, G. C. (Lieve); Bax, Caroline J.; Bekker, Mireille N.; Bilardo, Catia M.; Boon, Elles M. J.; Schuring‐Blom, G. Heleen; Coumans, Audrey B. C.; Faas, Brigitte H.; Galjaard, Robert‐Jan H.; Go, Attie T.; Henneman, Lidewij; Macville, Merryn V. E.; Pajkrt, Eva; Suijkerbuijk, Ron F.; Huijsdens‐van Amsterdam, Karin; Van Opstal, Diane; Verweij, E. J. (Joanne); Weiss, Marjan M.

    2016-01-01

    Abstract Objective To evaluate the clinical impact of nationwide implementation of genome‐wide non‐invasive prenatal testing (NIPT) in pregnancies at increased risk for fetal trisomies 21, 18 and 13 (TRIDENT study). Method Women with elevated risk based on first trimester combined testing (FCT ≥ 1:200) or medical history, not advanced maternal age alone, were offered NIPT as contingent screening test, performed by Dutch University Medical laboratories. We analyzed uptake, test performance, redraw/failure rate, turn‐around time and pregnancy outcome. Results Between 1 April and 1 September 2014, 1413/23 232 (6%) women received a high‐risk FCT result. Of these, 1211 (85.7%) chose NIPT. One hundred seventy‐nine women had NIPT based on medical history. In total, 1386/1390 (99.7%) women received a result, 6 (0.4%) after redraw. Mean turn‐around time was 14 days. Follow‐up was available in 1376 (99.0%) pregnancies. NIPT correctly predicted 37/38 (97.4%) trisomies 21, 18 or 13 (29/30, 4/4 and 4/4 respectively); 5/1376 (0.4%) cases proved to be false positives: trisomies 21 (n = 2), 18 (n = 1) and 13 (n = 2). Estimated reduction in invasive testing was 62%. Conclusion Introduction of NIPT in the Dutch National healthcare‐funded Prenatal Screening Program resulted in high uptake and a vast reduction of invasive testing. Our study supports offering NIPT to pregnant women at increased risk for fetal trisomy. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd. PMID:27750376

  9. Impact of early life exposure to antiepileptic drugs on neurobehavioral outcomes based on laboratory animal and clinical research.

    Science.gov (United States)

    Bath, Kevin G; Scharfman, Helen E

    2013-03-01

    Epilepsy affects approximately 1% of children under the age of 15, making it a very common neurological disorder in the pediatric population (Russ et al., 2012). In addition, ~0.4-0.8% of all pregnant women have some form of epilepsy (Hauser et al., 1996a,b; Borthen et al., 2009; Krishnamurthy, 2012). Despite the potential deleterious effects of antiepileptic drugs (AEDs) on the developing brain, their use is still required for seizure control in pregnant women (Krishnamurthy, 2012), and they represent the standard approach for treating children with epilepsy (Chu-Shore and Thiele, 2010; Quach et al., 2010; Verrotti et al., 2011). Even when AEDs are effective, there are potential side effects, including cognitive and affective changes or altered sleep and appetite. The consequences of AED exposure in development have been studied extensively (Canger et al., 1999; Modi et al., 2011a,b; Oguni, 2011). Despite intensive study, there is still debate about the long-term consequences of early life AED exposure. Here, we consider the evidence to date that AED exposure, either prenatally or in early postnatal life, has significant adverse effects on the developing brain and incorporate studies of laboratory animals as well as those of patients. We also note the areas of research where greater clarity seems critical in order to make significant advances. A greater understanding of the impact of AEDs on somatic, cognitive and behavioral development has substantial value because it has the potential to inform clinical practice and guide studies aimed at understanding the genetic and molecular bases of comorbid pathologies associated with common treatment regimens. Understanding these effects has the potential to lead to AEDs with fewer side effects. Such advances would expand treatment options, diminish the risk associated with AED exposure in susceptible populations, and improve the quality of life and health outcomes of children with epilepsy and children born to women who

  10. Impacts of Persian Gulf blackfin stonefish crude venom on the haematological factors and serum enzymes levels of laboratory rat

    Directory of Open Access Journals (Sweden)

    Amir Vazirizadeh

    2014-10-01

    Full Text Available Background: One of the venomous fishes of Persian Gulf is a type of stonefish called blackfin stonefish (Pseudosynanceia melanostigma that is very poorly-known. This fish lives on the muddy bottoms of marine shallow waters and have venomous spines on its stone like body. The envenomation usually is happened by unwanted contact of human body to its body and the proteinic venom is injected into the skin. Upon the venom entrance to the body various symptoms and signs will occur that their intensity depends on the venom amount.The aim of study is the understanding of some pharmacological impacts of blackfin stonefish for future studies. Material and Methods: A total of 18 male laboratory rats were divided into three groups of control, second and third and envenomed by sub lethal doses (1/3 LD50 and ½ LD50 intravenously and the serum enzymes namely Creatine Phosphokinase, Lactate Dehydrogenase, Glutamate-Oxaloacetate Transaminase, Gamma-Glutamyl Transpeptidase , Alkaline Phosphatase and Amylase, serum electrolytes namely Sodium. Potassium and Calcium and also complete blood cells of control and experimental rats were measured. Results: The serum enzymes levels, potassium and calcium levels and withe blood cells count in envenomed rats by blackfin stonefish crude venom in compare with control rats had significant increase while the haemoglobin level, red blood cells count and also serum sodium level had significant decrease (p<0.001. Conclusion: The increase in hepatomascular enzyme levels, and the decrease in haemoglobin level can be a probable marker of the presence of rhabdomyolysis, haemolysis and also hepatotoxicity activities in the blackfin stonefish venom and that needs to the histopathologic studies in these systems.

  11. Student motivation in a high school science laboratory: The impact of computers and other technologies on young adolescent physics students

    Science.gov (United States)

    Clark, Stephen Allan

    The impact of technology (including computers and probes, low friction carts, video camera, VCR's and electronic balances) on the motivation of adolescent science students was investigated using a naturalistic case study of college preparatory ninth grade physics classes at a comprehensive high school in the southeastern United States. The students were positively affected by the use of computer technology as compared to other "low tech" labs. The non-computer technologies had little motivational effect on the students. The most important motivational effect was the belief among the students that they could successfully operate the equipment and gather meaningful results. At times, the students spent more cognitive energy on performing the experiment than on learning the physics. This was especially true when microcomputer-based labs were used. When the technology led to results that were clear to the students and displayed in a manner that could be easily interpreted, they were generally receptive and motivated to persist at the task. Many students reported being especially motivated when a computer was used to gather the data because they "just liked computers." Furthermore, qualitative evidence suggested that they had learned the physics concept they were working on. This is in close agreement with the conceptual change model of learning in that students are most likely to change their prior conceptions when the new idea is plausible (the technology makes it so), intelligible (real time graphing, actual light rays), and fruitful (the new idea explains what they actually see). However, many of the microcomputer-based laboratory (MBL) activities and "high tech" labs were too unstructured, leaving students bewildered, confused and unmotivated. To achieve maximum motivational effects from the technology, it was necessary to reduce the cognitive demand on the students so they could concentrate on the data gathered rather than the operation of the equipment.

  12. Preliminary observations on the impact of complex stress histories on sandstone response to salt weathering: laboratory simulations of process combinations

    Science.gov (United States)

    McCabe, S.; Smith, B. J.; Warke, P. A.

    2007-03-01

    Historic sandstone structures carry an inheritance, or a ‘memory’, of past stresses that the stone has undergone since its placement in a façade. This inheritance, which conditions present day performance, may be made up of long-term exposure to a combination of low magnitude background environmental factors (for example, salt weathering, temperature and moisture cycling) and, superimposed upon these, less frequent but potentially high magnitude events or ‘exceptional’ factors (for example, lime rendering, severe frost events, fire). The impact of complex histories on the decay pathways of historic sandstone is not clearly understood, but this paper seeks to improve that understanding through the use of a laboratory ‘process combination’ study. Blocks of quartz sandstone (Peakmoor, from NW England) were divided into subsets that experienced different histories (lime rendering and removal, fire and freeze-thaw cycles in isolation and combination) that reflected the event timeline of a real medieval sandstone monument in NE Ireland, Bonamargy Friary (McCabe et al. 2006b). These subsets were then subject to salt weathering cycles using a 10% salt solution of NaCl and MgSO4 that represents the ‘every-day’ stress environment of, for example, sandstone structures in coastal, or polluted urban, location. Block response to salt weathering was monitored by collecting, drying and weighing the debris that was released as blocks were immersed in the salt solution at the beginning of each cycle. The results illustrate the complexity of the stone decay system, showing that seemingly small variations in stress history can produce divergent response to salt weathering cycles. Applied to real-world historic sandstone structures, this concept may help to explain the spatial and temporal variability of sandstone response to background environmental factors on a single façade, and encourage conservators to include the role of stress inheritance when selecting and

  13. Effect of Ballistic-Type Hot Atom Adsorption Mechanism on the Phase Diagram of Monomer-Dimer CO-O2 Surface Catalytic Reaction:A Monte Carlo Simulation

    Institute of Scientific and Technical Information of China (English)

    M. Khalid; K. M. Khan; A. U. Qaisrani; Q. N. Malik

    2004-01-01

    @@ We investigate the effect of the ballistic mechanism on the phase diagram using a square surface. While using this mechanism whenever an O2 molecule hits a randomly vacant selected site, the molecule breaks up into atomic form and then executes a ballistic flight. The paths of the two oxygen atoms are taken exactly to be opposite to each other, i.e. anti-parallel, and the ranges of the atoms are taken to be equal, i.e. they may fly up to 1 or 1.414 or 2 of the atomic spacing from the site of impact. Four cases have been studied on the basis of the range of hot atoms. The range of the hot oxygen atoms executing a ballistic flight might be up to the first nearest neighbourhood (1 atomic spacing from the site of impact), the second nearest neighbourhood (1.414 atomic spacing from the site of impact), the third nearest neighbourhood (2 atomic spacing from the site of impact),known as cases a, b, and c, respectively, while for case d the range of the oxygen atoms executing the ballistic flight might be up to 1 atomic spacing or 1.414 atomic spacing or 2 atomic spacing from the site of impact. The steady reactive window is observed and the continuous transition disappears. As soon as the CO partial pressure departs from zero, the production of CO2 is observed, which clearly verifies the experimental observation.

  14. On the influence of freight trains on humans: a laboratory investigation of the impact of nocturnal low frequency vibration and noise on sleep and heart rate.

    Directory of Open Access Journals (Sweden)

    Michael G Smith

    Full Text Available BACKGROUND: A substantial increase in transportation of goods on railway may be hindered by public fear of increased vibration and noise leading to annoyance and sleep disturbance. As the majority of freight trains run during night time, the impact upon sleep is expected to be the most serious adverse effect. The impact of nocturnal vibration on sleep is an area currently lacking in knowledge. We experimentally investigated sleep disturbance with the aim to ascertain the impact of increasing vibration amplitude. METHODOLOGY/PRINCIPAL FINDINGS: The impacts of various amplitudes of horizontal vibrations on sleep disturbance and heart rate were investigated in a laboratory study. Cardiac accelerations were assessed using a combination of polysomnography and ECG recordings. Sleep was assessed subjectively using questionnaires. Twelve young, healthy subjects slept for six nights in the sleep laboratory, with one habituation night, one control night and four nights with a variation of vibration exposures whilst maintaining the same noise exposure. With increasing vibration amplitude, we found a decrease in latency and increase in amplitude of heart rate as well as a reduction in sleep quality and increase in sleep disturbance. CONCLUSIONS/SIGNIFICANCE: We concluded that nocturnal vibration has a negative impact on sleep and that the impact increases with greater vibration amplitude. Sleep disturbance has short- and long-term health consequences. Therefore, it is necessary to define levels that protect residents against sleep disruptive vibrations that may arise from night time railway freight traffic.

  15. Development of Mortar Simulator with Shell-In-Shell System – Problem of External Ballistics

    Directory of Open Access Journals (Sweden)

    A. Fedaravicius

    2007-01-01

    Full Text Available The shell-in-shell system used in the mortar simulator raises a number of non-standard technical and computational problems starting from the requirement to distribute the propelling blast energy between the warhead and the ballistic barrel, finishing with the requirement that the length of warhead's flight path must be scaled to combat shell firing tables. The design problem of the simulator is split into two parts – the problem of external ballistics where the initial velocities of the warhead must be determined, and the problem of internal ballistics – where the design of the cartridge and the ballistic barrel must be performed.

  16. 24th International Symposium on Ballistics

    Science.gov (United States)

    2008-09-26

    launch dynamics Chaired by Don Carlucci & ken kuo 1:30 pm IB098 Numerical Simulation of Projectile Acceleration Process Using Solid/Gas Two-Phase...analysis Wilber related the size and shape of fracture damage To the radius of curvature of the impacting weapon. intersecting chord theorem 0 2...4 6 8 10 100 1000 Radius of curvature (mm) F o r c e ( K n ) Wilber helmet shells 50 cal helmet 1 50 cal concept 50 cal helmet 2 30 cal concept Log

  17. Rigorous model-based uncertainty quantification with application to terminal ballistics, part I: Systems with controllable inputs and small scatter

    Science.gov (United States)

    Kidane, A.; Lashgari, A.; Li, B.; McKerns, M.; Ortiz, M.; Owhadi, H.; Ravichandran, G.; Stalzer, M.; Sullivan, T. J.

    2012-05-01

    This work is concerned with establishing the feasibility of a data-on-demand (DoD) uncertainty quantification (UQ) protocol based on concentration-of-measure inequalities. Specific aims are to establish the feasibility of the protocol and its basic properties, including the tightness of the predictions afforded by the protocol. The assessment is based on an application to terminal ballistics and a specific system configuration consisting of 6061-T6 aluminum plates struck by spherical S-2 tool steel projectiles at ballistic impact speeds. The system's inputs are the plate thickness and impact velocity and the perforation area is chosen as the sole performance measure of the system. The objective of the UQ analysis is to certify the lethality of the projectile, i.e., that the projectile perforates the plate with high probability over a prespecified range of impact velocities and plate thicknesses. The net outcome of the UQ analysis is an M/U ratio, or confidence factor, of 2.93, indicative of a small probability of no perforation of the plate over its entire operating range. The high-confidence (>99.9%) in the successful operation of the system afforded the analysis and the small number of tests (40) required for the determination of the modeling-error diameter, establishes the feasibility of the DoD UQ protocol as a rigorous yet practical approach for model-based certification of complex systems.

  18. Impact Testing on Reinforced Carbon-Carbon Flat Panels With BX-265 and PDL-1034 External Tank Foam for the Space Shuttle Return to Flight Program

    Science.gov (United States)

    Melis, Matthew E.; Revilock, Duane M.; Pereira, Michael J.; Lyle, Karen H.

    2009-01-01

    Following the tragedy of the Orbiter Columbia (STS-107) on February 1, 2003, a major effort commenced to develop a better understanding of debris impacts and their effect on the space shuttle subsystems. An initiative to develop and validate physics-based computer models to predict damage from such impacts was a fundamental component of this effort. To develop the models it was necessary to physically characterize reinforced carbon-carbon (RCC) along with ice and foam debris materials, which could shed on ascent and impact the orbiter RCC leading edges. The validated models enabled the launch system community to use the impact analysis software LS-DYNA (Livermore Software Technology Corp.) to predict damage by potential and actual impact events on the orbiter leading edge and nose cap thermal protection systems. Validation of the material models was done through a three-level approach: Level 1-fundamental tests to obtain independent static and dynamic constitutive model properties of materials of interest, Level 2-subcomponent impact tests to provide highly controlled impact test data for the correlation and validation of the models, and Level 3-full-scale orbiter leading-edge impact tests to establish the final level of confidence for the analysis methodology. This report discusses the Level 2 test program conducted in the NASA Glenn Research Center (GRC) Ballistic Impact Laboratory with external tank foam impact tests on flat RCC panels, and presents the data observed. The Level 2 testing consisted of 54 impact tests in the NASA GRC Ballistic Impact Laboratory on 6- by 6-in. and 6- by 12-in. flat plates of RCC and evaluated two types of debris projectiles: BX-265 and PDL-1034 external tank foam. These impact tests helped determine the level of damage generated in the RCC flat plates by each projectile and validated the use of the foam and RCC models for use in LS-DYNA.

  19. SWEIS Yearbook-2012 Comparison of 2012 Data to Projections of the 2008 Site-Wide Environmental Impact Statement for Continued Operation of Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Mahowald, Hallie B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wright, Marjorie Alys [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-16

    Los Alamos National Laboratory (LANL or the Laboratory) operations data for Calendar Year (CY) 2012 mostly fell within the 2008 Site-Wide Environmental Impact Statement (SWEIS) projections. Operation levels for one LANL facility exceeded the 2008 SWEIS capability projections—Radiochemistry Facility; however, none of the capability increases caused exceedances in radioactive air emissions, waste generation, or National Pollutant Discharge Elimination System (NPDES) discharge. Several facilities exceeded the2008 SWEIS levels for waste generation quantities; however, all were one-time, non-routine events that do not reflect the day-to-day operations of the Laboratory. In addition, total site-wide waste generation quantities were below SWEIS projections for all waste types, reflecting the overall levels of operations at both the Key and Non-Key Facilities. Although gas and electricity consumption have remained within the 2008 SWEIS limits for utilities, water consumption exceeded the 2008 SWEIS projections by 27 million gallons in CY 2012.

  20. Los Alamos and Lawrence Livermore National Laboratories Code-to-Code Comparison of Inter Lab Test Problem 1 for Asteroid Impact Hazard Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Robert P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Miller, Paul [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Howley, Kirsten [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ferguson, Jim Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gisler, Galen Ross [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Plesko, Catherine Suzanne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Managan, Rob [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Owen, Mike [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wasem, Joseph [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bruck-Syal, Megan [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-15

    The NNSA Laboratories have entered into an interagency collaboration with the National Aeronautics and Space Administration (NASA) to explore strategies for prevention of Earth impacts by asteroids. Assessment of such strategies relies upon use of sophisticated multi-physics simulation codes. This document describes the task of verifying and cross-validating, between Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL), modeling capabilities and methods to be employed as part of the NNSA-NASA collaboration. The approach has been to develop a set of test problems and then to compare and contrast results obtained by use of a suite of codes, including MCNP, RAGE, Mercury, Ares, and Spheral. This document provides a short description of the codes, an overview of the idealized test problems, and discussion of the results for deflection by kinetic impactors and stand-off nuclear explosions.

  1. The economic impact of Los Alamos National Laboratory on north-central New Mexico and the state of New Mexico fiscal year 1997

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, R.R.; Nielsen, T.G.; Schultz, J. [New Mexico State Univ., Las Cruces, NM (United States); Adcock, L.D.; Gentry, L.M. [Dept. of Energy, Albuquerque, NM (United States). Albuquerque Operations Office; Ben-David, S. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Economics; Temple, J. [Temple (John), Albuquerque, NM (United States)

    1998-05-29

    Los Alamos National Laboratory (LANL) is a multidisciplinary, multiprogram laboratory with a mission to enhance national military and economic security through science and technology. Its mission is to reduce the nuclear danger through stewardship of the nation`s nuclear stockpile and through its nonproliferation and verification activities. An important secondary mission is to promote US industrial competitiveness by working with US companies in technology transfer and technology development partnerships. Los Alamos is involved in partnerships and collaborations with other federal agencies, with industry (including New Mexico businesses), and with universities worldwide. For this report, the reference period is FY 1997 (October 1, 1996, through September 30, 1997) and includes two major impact analysis: the impact of LANL activities on north-central New Mexico and the economic impacts of LANL on the state of New Mexico. Total impact represents both direct and indirect respending by business, including induced effects (respending by households). The standard multipliers used in determining impacts result from the inter-industry, input-output models developed for the three-county region and the state of New Mexico. 5 figs., 12 tabs.

  2. The economic impact of Los Alamos National Laboratory on north-central New Mexico and the state of New Mexico fiscal year 1998

    Energy Technology Data Exchange (ETDEWEB)

    Lansford, R.R. [New Mexico State Univ., Las Cruces, NM (US); Adcock, L.D.; Gentry, L.M. [Albuquerque Operations Office, Dept. of Energy, Albuquerque, NM (US); Ben-David, S. [Univ. of New Mexico, Albuquerque, NM (US). Dept. of Economics; Temple, J. [Temple (John), Albuquerque, NM (US)

    1999-08-05

    Los Alamos National Laboratory (LANL) is a multidisciplinary, multiprogram laboratory with a mission to enhance national military and economic security through science and technology. Its mission is to reduce the nuclear danger through stewardship of the nation`s nuclear stockpile and through its nonproliferation and verification activities. An important secondary mission is to promote US industrial competitiveness by working with US companies in technology transfer and technology development partnerships. Los Alamos is involved in partnerships and collaborations with other federal agencies, with industry (including New Mexico businesses), and with universities worldwide. For this report, the reference period is FY 1998 (October 1, 1997, through September 30, 1998). It includes two major impact analysis: the impact of LANL activities on north-central New Mexico and the economic impacts of LANL on the state of New Mexico. Total impact represents both direct and indirect responding by business, including induced effects (responding by households). The standard multipliers used in determining impacts result from the inter-industry, input-output models developed for the three-county region and the state of New Mexico.

  3. Experimental techniques for design of impact-resistant material (poster)

    NARCIS (Netherlands)

    Fan, J.; Weerheijm, J.; Sluys, L.J.

    2013-01-01

    Some polymers are not only transparent and lightweight, but also impact and ballistic resistant. Designing and preparing such polymeric materials with a high impact‐resistant performance is of importance to e.g. aviation, military and windscreen applications.

  4. Experimental techniques for design of impact-resistant material (poster)

    NARCIS (Netherlands)

    Fan, J.; Weerheijm, J.; Sluys, L.J.

    2013-01-01

    Some polymers are not only transparent and lightweight, but also impact and ballistic resistant. Designing and preparing such polymeric materials with a high impact‐resistant performance is of importance to e.g. aviation, military and windscreen applications.

  5. Using Instrumental Neutron Activation Analysis for geochemical analyses of terrestrial impact structures: Current analytical procedures at the University of Vienna Geochemistry Activation Analysis Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Mader, Dieter [Department of Lithospheric Research, University of Vienna, Althanstrasse 14, 1090 Vienna (Austria)], E-mail: dieter.mader@univie.ac.at; Koeberl, Christian [Department of Lithospheric Research, University of Vienna, Althanstrasse 14, 1090 Vienna (Austria)], E-mail: christian.koeberl@univie.ac.at

    2009-12-15

    The Instrumental Neutron Activation Analysis Gamma Spectroscopy Laboratory at the Department of Lithospheric Research, University of Vienna, has been upgraded in the year 2006. This paper describes the sample preparation, new instrumentation and data evaluation for hundreds of rock samples of two terrestrial impact structures. The measurement and data evaluation are done by using Genie{sup TM} 2000 and a custom-made batch software for the used analysis sequences.

  6. 48 CFR 225.7016 - Restriction on Ballistic Missile Defense research, development, test, and evaluation.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restriction on Ballistic Missile Defense research, development, test, and evaluation. 225.7016 Section 225.7016 Federal Acquisition... Acquisition 225.7016 Restriction on Ballistic Missile Defense research, development, test, and evaluation. ...

  7. Results of a Round Robin ballistic load sensing headform test series

    NARCIS (Netherlands)

    Philippens, M.A.G.; Anctil, B.; Markwardt, K.C.

    2014-01-01

    The majority of methods to assess the behind armour blunt trauma (BABT) risk for ballistic helmets is based on plastic deformable headforms. An alternative, the Ballistic Load Sensing Headform (BLSH) can record the dynamic contact force between helmet back face and the skull. Helmet BABT methods are

  8. Results of a Round Robin ballistic load sensing headform test series

    NARCIS (Netherlands)

    Philippens, M.A.G.; Anctil, B.; Markwardt, K.C.

    2014-01-01

    The majority of methods to assess the behind armour blunt trauma (BABT) risk for ballistic helmets is based on plastic deformable headforms. An alternative, the Ballistic Load Sensing Headform (BLSH) can record the dynamic contact force between helmet back face and the skull. Helmet BABT methods are

  9. Persistent currents for interacting electrons in ballistic/chaotic billiards

    Science.gov (United States)

    Zelyak, Oleksandr; Murthy, Ganpathy

    2005-03-01

    We study persistent currents in a quantum billiard enclosing a magnetic flux φ by analytical and numerical methods. We concentrate on the family of Robnik-Berry billiards generated by conformal maps of the unit disk. We study the persistent current as a function of magnetic flux and parameters of the billiard in the chaotic regime. We include Fermi-liquid interactions in a mean-field approach, justified by the recent large-N approach[1] for ballistic/chaotic quantum dots. [1] G. Murthy, R. Shankar, D. Herman, and H. Mathur, Phys. Rev. B 69, 075321 (2004); G. Murthy, R. Shankar, and H. Mathur, cond-mat/0411280.

  10. Ballistic Reconstruction of a Migrating Bullet in the Parapharyngeal Space

    Directory of Open Access Journals (Sweden)

    David Bächinger

    2015-01-01

    Full Text Available A 21-year-old male suffering from severe throat pain after being hit by a bullet in Syria claimed that he was shot through his eye and that the bullet subsequently descended behind his throat. Even though the first medical report stated that this course is implausible, meticulous workup provided evidence that the bullet might have entered the parapharyngeal space in a more cranial position than the one it was found eight months later. Our case highlights that bullets are able to move within the body, rendering ballistic reconstruction difficult. However, after removal of the bullet the patient’s symptoms completely resolved.

  11. Two-wavelength phase shift interferometry to characterize ballistic features

    Science.gov (United States)

    Pagano, Glenn W.; Mann, Christopher J.

    2014-05-01

    We apply two-wavelength phase shifting interferometry to generate 3D surface profile maps of spent bullet cartridge cases. From the captured interferograms, an optimized algorithm was used to calculate a phase profile from which a precise digital surface map of the cartridge casing may be produced. This 3D surface profile is used to enhance a firearms examiner's ability to uniquely identify distinct features or toolmarks imprinted on the casing when the weapon is fired. These features play a key role in the matching process of ballistic forensic examination.

  12. Scaling of ballistic deposition from a Langevin equation.

    Science.gov (United States)

    Haselwandter, Christoph A; Vvedensky, Dimitri D

    2006-04-01

    An exact lattice Langevin equation is derived for the ballistic deposition model of surface growth. The continuum limit of this equation is dominated by the Kardar-Parisi-Zhang (KPZ) equation at all length and time scales. For a one-dimensional substrate the solution of the exact lattice Langevin equation yields the KPZ scaling exponents without any extrapolation. For a two-dimensional substrate the scaling exponents are different from those found from computer simulations. This discrepancy is discussed in relation to analytic approaches to the KPZ equation in higher dimensions.

  13. Probing magnetic microstructures with quasi-ballistic Hall crosses

    Science.gov (United States)

    Fasbender, S.; Schluck, J.; Cerchez, M.; Heinzel, T.; Sievers, S.; Pierz, K.; Schumacher, H. W.

    2016-03-01

    Hall sensing is performed on a localized magnetic field pattern using a quasi-ballistic Hall cross device. The Hall resistance shows a pronounced peak as a function of the magnetic field amplitude which is absent in the magnetization hysteresis loop. This non-monotonic response exemplifies qualitatively the failure of conventional Hall sensing. It is demonstrated how, by using a numerical simulation based on the Landauer-Büttiker model, the amplitude of the magnetic field profile can be determined from such measurements.

  14. Ballistic electron propagation through periodic few-layer graphene nanostructures

    Science.gov (United States)

    Dragoman, Daniela; Mihalache, Iulia

    2016-10-01

    We have studied electron propagation in periodic structures containing mono- and few-layer graphene regions and/or semiconducting stripes. The calculation of the transmission coefficient in all cases has been performed using transfer matrices inside regions with the same material/potential energy, as well as interface matrices between regions in which the evolution laws of charge carriers differ. Numerical simulations of the transmission coefficient, as well as of the low-temperature conductance, suggest that different periodic structures modulate differently the electrical current. The obtained results can be used to model ballistic transport in all-graphene devices, in particular in few-layer graphene structures.

  15. Computer Aided Ballistic Orbit Classification Around Small Bodies

    Science.gov (United States)

    Villac, Benjamin F.; Anderson, Rodney L.; Pini, Alex J.

    2016-09-01

    Orbital dynamics around small bodies are as varied as the shapes and dynamical states of these bodies. While various classes of orbits have been analyzed in detail, the global overview of relevant ballistic orbits at particular bodies is not easily computed or organized. Yet, correctly categorizing these orbits will ease their future use in the overall trajectory design process. This paper overviews methods that have been used to organize orbits, focusing on periodic orbits in particular, and introduces new methods based on clustering approaches.

  16. Minimum Ballistic Factor Problem of Slender Axial Symmetric Missiles

    Directory of Open Access Journals (Sweden)

    V. B. Tawakley

    1979-01-01

    Full Text Available The problem of determining the geometry of slender, axisymmetric missiles of minimum ballistic factor in hypersonic flow has been solved via the calculus of variations under the assumptions that the flow is Newtonian and the surface averaged skin-friction coefficient is constant. The study has been made for conditions of given length and diameter, given diameter and surfacearea, and given surface area and length. The earlier investigations/sup 8/ where only regular shapes were determined has been extended to cover those class of bodies which consist of regular shapes followed or preceded by zero slope shapes.

  17. Aerodynamic heating of ballistic missile including the effects of gravity

    Indian Academy of Sciences (India)

    S N Maitra

    2000-10-01

    The aerodynamic heating of a ballistic missile due to only convection is analysed taking into consideration the effects of gravity. The amount of heat transferred to the wetted area and to the nose region has been separately determined, unlike A Miele's treatise without consideration of gravity. The peak heating ratesto the wetted area and to the nose of the missile are also investigated. Finally four numerical examples are cited to estimate the errors, in heat transfers and heating ratesto both wetted area and nose region of the missile, arising out of neglecting the gravitational forces.

  18. Development of ballistics identification—from image comparison to topography measurement in surface metrology

    Science.gov (United States)

    Song, J.; Chu, W.; Vorburger, T. V.; Thompson, R.; Renegar, T. B.; Zheng, A.; Yen, J.; Silver, R.; Ols, M.

    2012-05-01

    Fired bullets and ejected cartridge cases have unique ballistics signatures left by the firearm. By analyzing the ballistics signatures, forensic examiners can trace these bullets and cartridge cases to the firearm used in a crime scene. Current automated ballistics identification systems are primarily based on image comparisons using optical microscopy. The correlation accuracy depends on image quality which is largely affected by lighting conditions. Because ballistics signatures are geometrical micro-topographies by nature, direct measurement and correlation of the surface topography is being investigated for ballistics identification. A Two-dimensional and Three-dimensional Topography Measurement and Correlation System was developed at the National Institute of Standards and Technology for certification of Standard Reference Material 2460/2461 bullets and cartridge cases. Based on this system, a prototype system for bullet signature measurement and correlation has been developed for bullet signature identifications, and has demonstrated superior correlation results.

  19. The 25 September 2007 eruption of Mount Ruapehu, New Zealand: Directed ballistics, surtseyan jets, and ice-slurry lahars

    Science.gov (United States)

    Kilgour, G.; Manville, V.; Della Pasqua, F.; Graettinger, A.; Hodgson, K. A.; Jolly, G. E.

    2010-03-01

    At 20:26 (NZDT) on 25 September 2007 a moderate gas-driven eruption beneath the summit Crater Lake of Mt. Ruapehu, New Zealand generated a directed ballistic fallout apron and surtseyan jet that impacted an area of c. 2.5 km 2 to the north of the vent. Two climbers were caught in the blast at a hut 600 m from the vent. Primary, ice-slurry lahars were generated in two catchments draining the summit region, including a flow that entered a commercial ski field. The ejecta consists of blocks of andesitic lava and scoria erupted during previous volcanic episodes, a variety of mineral-cemented lake-floor sediments, vent-fill debris and rare glassy material interpreted to be derived from a fresh batch of magma. A minority of clasts contain formerly molten elemental sulphur, indicating that vent temperatures at the base of the lake were in excess of 119 °C. The ballistic deposit is confined to a c. 40° wide swath directed northwards that extends up to 2 km from the inferred vent location beneath Crater Lake. The strong directionality of the jetted deposits and ballistic-free 'shadow-zones' sheltered by intervening topography all point to a relatively low-angle directed blast. Previous similar eruptions at Ruapehu also show preferred deposit orientations that are here correlated with an inclined and off-centre vent beneath Crater Lake. The 25 September 2007 eruption appears to have resulted from failure of a relatively shallow hydrothermal seal composed of elemental sulphur and other mineral precipitates developed in the vent breccia, which breached following overpressurization by a pulse of magmatic gases released from deeper in the conduit. This event highlights the potential hazard from relatively minor gas-driven eruptions at Ruapehu that can occur with little or no warning. Improved understanding of the eruption mechanism for this style of eruption will inform future risk assessments for Ruapehu and other similar volcanoes worldwide.

  20. Robust Hybrid Control for Ballistic Missile Longitudinal Autopilot

    Institute of Scientific and Technical Information of China (English)

    WAEL Mohsen Ahmed; QUAN Quana

    2011-01-01

    This paper investigates the boost phase's longitudinal autopilot of a ballistic missile equipped with thrust vector control.The existing longitudinal autopilot employs time-invariant passive resistor-inductor-capacitor (RLC) network compensator as a control strategy,which does not take into account the time-varying missile dynamics.This may cause the closed-loop system instability in the presence of large disturbance and dynamics uncertainty.Therefore,the existing controller should be redesigned to achieve more stable vehicle response.In this paper,based on gain-scheduling adaptive control strategy,two different types of optimal controllers are proposed.The first controller is gain-scheduled optimal tuning-proportional-integral-derivative (PID) with actuator constraints,which supplies better response but requires a priori knowledge of the system dynamics.Moreover,the controller has oscillatory response in the presence of dynamic uncertainty.Taking this into account,gain-scheduled optimal linear quadratic (LQ) in conjunction with optimal tuning-compensator offers the greatest scope for controller improvement in the presence of dynamic uncertainty and large disturbance.The latter controller is tested through various scenarios for the validated nonlinear dynamic flight model of the real ballistic missile system with autopilot exposed to external disturbances.