Sample records for air gun sounds

  1. Air guns: toys or weapons? (United States)

    Aslan, Sahin; Uzkeser, Mustafa; Katirci, Yavuz; Cakir, Zeynep; Bilir, Ozlem; Bilge, Fatih; Cakir, Murtaza


    Air guns and blank guns may appear relatively harmless at first glance, but they are, in fact, potentially destructive, even lethal, weapons. Approximately 2 to 2.5 million nonpowder firearms are sold annually, and again approximately 12.9 per 100,000 population are treated for such injuries in hospital emergency departments each year in the United States. Unfortunately, these guns are considered to be a toy for children. Therefore, incidents of air gun injuries are gradually increasing. Although such injuries may initially be considered trivial, it may signify severe internal tissue pathologies. These apparently trivial injuries may have catastrophic consequences if unnoticed. In this study, we report 4 cases with head injury due to a shot by these guns. The cases indicate that these people had used the guns belonging to their parents for the purpose of suicide. The cases also show that these machines are not innocent.

  2. Reverse Ballistic Air Gun Facility (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...

  3. Reverse Ballistic Air Gun Facility (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...

  4. Effects of Seismic Air Guns on Pallid Sturgeon and Paddlefish. (United States)

    Popper, Arthur N; Carlson, Thomas J; Gross, Jackson A; Hawkins, Anthony D; Zeddies, David; Powell, Lynwood; Young, John


    Pallid sturgeon and paddlefish were placed at different distances from a seismic air gun array to determine the potential effects on mortality and nonauditory body tissues from the sound from a single shot. Fish were held 7 days postexposure and then necropsied. No fish died immediately after sound exposure or over the postexposure period. Statistical analysis of injuries showed no differences between the experimental and control animals in either type or severity of injuries. There was also no difference in injuries between fish exposed closest to the source compared with those exposed furthest from the source.

  5. Development of a model to assess masking potential for marine mammals by the use of air guns in Antarctic waters

    NARCIS (Netherlands)

    Wittekind, D.; Tougaard, J.; Stilz, P.; Dähne, M.; Clark, C.W.; Lucke, K.; Benda-Beckmann, A.M. von; Ainslie, M.A.; Siebert, U.


    We estimated the long-range effects of air gun array noise on marine mammal communication ranges in the Southern Ocean. Air gun impulses are subject to significant distortion during propagation, potentially resulting in a quasi- continuous sound. Propagation modeling to estimate the received wavefor

  6. Development of a model to assess masking potential for marine mammals by the use of air guns in Antarctic waters

    NARCIS (Netherlands)

    Wittekind, Dietrich; Tougaard, Jakob; Stilz, Peter; Dähne, Michael; Clark, Christopher W.; Lucke, K.; Benda-Beckmann, von Sander; Ainslie, Michael A.; Siebert, Ursula


    We estimated the long-range effects of air gun array noise on marine mammal communication ranges in the Southern Ocean. Air gun impulses are subject to significant distortion during propagation, potentially resulting in a quasi- continuous sound. Propagation modeling to estimate the received wave

  7. Fired Models of Air-gun Source and Its Application

    Institute of Scientific and Technical Information of China (English)

    Luo Guichun; Ge Hongkui; Wang Baoshan; Hu Ping; Mu Hongwang; Chen Yong


    Air-gun is an important active seismic source. With the development of the theory about air-gun array, the technique for air-gun array design becomes mature and is widely used in petroleum exploration and geophysics. In order to adapt it to different research domains,different combination and fired models are needed. At the present time, there are two firedmodels of air-gun source, namely, reinforced initial pulse and reinforced first bubble pulse.The fired time, space between single guns, frequency and resolution of the two models are different. This comparison can supply the basis for its extensive application.

  8. Use of a seismic air gun to reduce survival of nonnative lake trout embryos: A tool for conservation? (United States)

    Cox, B.S.; Dux, A.M.; Quist, M.C.; Guy, C.S.


    The detrimental impacts of nonnative lake trout Salvelinus namaycush in the western USA have prompted natural resource management agencies in several states to implement lake trout suppression programs. Currently, these programs rely on mechanical removal methods (i.e., gill nets, trap nets, and angling) to capture subadult and adult lake trout. We conducted a study to explore the potential for using high-intensity sound from a relatively small (655.5 cm3 [40 in3]) seismic air gun to reduce survival of lake trout embryos. Lake trout embryos at multiple stages of development were exposed to a single discharge of the seismic air gun at two depths (5 and 15 m) and at two distances from the air gun (0.1 and 2.7 m). Control groups for each developmental stage, distance, and depth were treated identically except that the air gun was not discharged. Mortality in lake trout embryos treated at 0.1 m from the air gun was 100% at 74 daily temperature units in degrees Celsius (TU°C) at both depths. Median mortality in lake trout embryos treated at 0.1 m from the air gun at 207 TU°C (93%) and 267 °C (78%) appeared to be higher than that of controls (49% and 48%, respectively) at 15-m depth. Among the four lake trout developmental stages, exposure to the air gun at 0.1 m resulted in acute mortality up to 60% greater than that of controls. Mortality at a distance of 2.7 m did not appear to differ from that of controls at any developmental stage or at either depth. Our results indicate that seismic air guns have potential as an alternative tool for controlling nonnative lake trout, but further investigation is warranted.

  9. Air gun injury with deadly aftermath--case report. (United States)

    Stankov, Aleksandar; Jakovski, Zlatko; Pavlovski, Goran; Muric, Nedzat; Dwork, Andrew J; Cakar, Zdravko


    In Republic of Macedonia the use of air guns is quite widespread. They are used mainly for target practice. They are regulated by the Law of Arms, where they are defined as pneumatic weapons. There is no legal limit on type or quantity of ammunition that one may possess. Our Institute performs at least 90% of the forensic autopsies in Macedonia. In this report we describe the only fatality by pneumatic weapon to come to our attention over the past 10 years. A 6-year-old girl was accidentally wounded by her brother when he and his father were trying a new air gun, a 4.5mm single shot, break barrel, spring piston air rifle manufactured in China under the brand "Westlake". She died within minutes. Autopsy showed cardiac tamponade due to penetration of the aorta. A 0.5g metal projectile, 4.5mm in diameter, with a pointed, conical shape, was recovered from the pericardial sac.

  10. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase (United States)

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui; Zhang, Jue; Fang, Jing


    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  11. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang, Jue, E-mail:; Fang, Jing [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China)


    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  12. Shipboard assessment of hearing sensitivity of tropical fishes immediately after exposure to seismic air gun emissions at Scott Reef. (United States)

    Hastings, Mardi C; Miksis-Olds, Jennifer


    This is the first study to examine the potential effects of emissions from an air gun array on hearing of tropical reef fish using AEP thresholds measured in the field. Over 7 days, 51 Chromis viridis,47 Lutjanus kasmira, 20 Myripristis murdjan, and 10 Sargocentron spiniferum were tested. AEP thresholds were determined before and after exposure to emissions from one or two passes of an airgun array. Temporary threshold shift resulting from sound exposure was not found in any species,even when cumulative sound exposure levels reached 190 dB re 1 μPa2-s.

  13. Air gun injuries of the abdomen in children. (United States)

    Morgan, J C; Turner, C S; Pennell, T C


    From July 18, 1978 to Sept 15, 1982, four boys were treated for air gun injuries of the abdomen at the North Carolina Baptist Hospital, Winston-Salem. Three patients had wounds of one or more of the hollow viscera, and one patient had an injury only of the liver. There was no morbidity or mortality following repair. Some present-day air (pneumatic) weapons have muzzle velocities that equal or exceed those of common civilian handguns, and they are frequently used by unsupervised children. These weapons are not restricted and regulated as are other firearms, and are believed to be incapable of serious injury other than to the eye. These cases and others in the literature dispute that belief.

  14. Air pollution:a smoking gun for cancer

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang; Chao-Nan Qian; Yi-Xin Zeng


    Once considered a taboo topic or stigma, cancer is the number one public health enemy in the world. Once a product of an almost untouchable industry, tobacco is indisputably recognized as a major cause of cancer and a target for anticancer efforts. With the emergence of new economic powers in the world, especial y in highly populated countries such as China, air pol ution has rapidly emerged as a smoking gun for cancer and has become a hot topic for public health debate because of the complex political, economic, scientific, and technologic issues surrounding the air pollution problem. This editorial and the referred articles published in this special issue of the Chinese Journal of Cancer discuss these fundamental questions. Does air pollution cause a wide spectrum of cancers? Should air pollution be considered a necessary evil accompanying economic transformation in developing countries? Is an explosion of cancer incidence coming to China and how soon wil it arrive? What must be done to prevent this possible human catastrophe? Final y, the approaches for air pol ution control are also discussed.

  15. Air gun wounding and current UK laws controlling air weapons. (United States)

    Bruce-Chwatt, Robert Michael


    Air weapons whether rifles or pistols are, potentially, lethal weapons. The UK legislation is complex and yet little known to the public. Hunting with air weapons and the laws controlling those animals that are permitted to be shot with air weapons is even more labyrinthine due to the legal power limitations on the possession of air weapons. Still relatively freely available by mail order or on the Internet, an increasing number of deaths have been reported from the misuse of air weapons or accidental discharges. Ammunition for air weapons has become increasingly sophisticated, effective and therefore increasingly dangerous if misused, though freely available being a mere projectile without a concomitant cartridge containing a propellant and an initiator.


    Directory of Open Access Journals (Sweden)

    Bysko Maxim V.


    Full Text Available The author examines the role of broadcasting from inception to the present day; he means a new historical round of mass media that links modern radio with 1920-30s radio. Art genres of broadcasting and TV news covered in the direct synthesis with information radio genres. In this case, a more organized and balanced sounding of contemporary information radio (order of texts, music-speech structure, and sound design has a more limited, local space in society. Radio is not only within national boundaries, but also within cultural, subcultural, narrow consumer boundaries. Hence the clear dominance of the road radio audience, as well as a return to the private broadcasting (mobiles, web-channels, podcasts.

  17. Seismic air gun exposure during early-stage embryonic development does not negatively affect spiny lobster Jasus edwardsii larvae (Decapoda: Palinuridae). (United States)

    Day, Ryan D; McCauley, Robert D; Fitzgibbon, Quinn P; Semmens, Jayson M


    Marine seismic surveys are used to explore for sub-seafloor oil and gas deposits. These surveys are conducted using air guns, which release compressed air to create intense sound impulses, which are repeated around every 8-12 seconds and can travel large distances in the water column. Considering the ubiquitous worldwide distribution of seismic surveys, the potential impact of exposure on marine invertebrates is poorly understood. In this study, egg-bearing female spiny lobsters (Jasus edwardsii) were exposed to signals from three air gun configurations, all of which exceeded sound exposure levels (SEL) of 185 dB re 1 μPa(2) · s. Lobsters were maintained until their eggs hatched and the larvae were then counted for fecundity, assessed for abnormal morphology using measurements of larval length and width, tested for larval competency using an established activity test and measured for energy content. Overall there were no differences in the quantity or quality of hatched larvae, indicating that the condition and development of spiny lobster embryos were not adversely affected by air gun exposure. These results suggest that embryonic spiny lobster are resilient to air gun signals and highlight the caution necessary in extrapolating results from the laboratory to real world scenarios or across life history stages.

  18. Phase characteristic analysis of continuous depth air-gun source wavelet (United States)

    Xing, Lei; Liu, Huaishan; Zheng, Xilai; Liu, Xueqin; Zhang, Jin; Wang, Linfei; Zou, Zhihui; Xu, Yiming


    Air guns are important sources for marine seismic exploration. Far-field wavelet of air gun arrays, as a necessary parameter for pre-stack processing and source models, plays an important role during marine seismic data processing and interpretation. When an air gun fires, it generates a series of air bubbles. Similar to onshore seismic exploration, the water forms a plastic fluid near the bubble; the farther the air gun is located from the measurement, the more steady and more accurately represented the wavelet will be. In practice, hydrophones should be placed more than 100 m from the air gun; however, traditional seismic cables cannot meet this requirement. On the other hand, vertical cables provide a viable solution to this problem. This study uses a vertical cable to receive wavelets from 38 air guns and data are collected offshore Southeast Qiong, where the water depth is over 1000 m. In this study, the wavelets measured using this technique coincide very well with the simulated wavelets and can therefore represent the real shape of the wavelets. This experiment fills a technology gap in China.

  19. Impact of air gun noise on the behaviour of marine fish and squid. (United States)

    Fewtrell, J L; McCauley, R D


    In this study various species of captive marine fish and one species of squid were exposed to the noise from a single air gun. Six trials were conducted off the coast of Western Australia with each trial using a different noise exposure regime. Noise levels received by the animals ranged between 120 and 184 dB re 1 μPa(2).s (SEL). Behavioural observations of the fish and squid were made before, during and after air gun noise exposure. Results indicate that as air gun noise levels increase, fish respond by moving to the bottom of the water column and swimming faster in more tightly cohesive groups. Significant increases in alarm responses were observed in fish and squid to air gun noise exceeding 147-151 dB re 1 μPa SEL. An increase in the occurrence of alarm responses was also observed as noise level increased.

  20. Influence of pellet seating on the external ballistic parameters of spring-piston air guns. (United States)

    Werner, Ronald; Schultz, Benno; Frank, Matthias


    In firearm examiners' and forensic specialists' casework as well as in air gun proof testing, reliable measurement of the weapon's muzzle velocity is indispensable. While there are standardized and generally accepted procedures for testing the performance of air guns, the method of seating the diabolo pellets deeper into the breech of break barrel spring-piston air guns has not found its way into standardized test procedures. The influence of pellet seating on the external ballistic parameters was investigated using ten different break barrel spring-piston air guns. Test shots were performed with the diabolo pellets seated 2 mm deeper into the breech using a pellet seater. The results were then compared to reference shots with conventionally loaded diabolo pellets. Projectile velocity was measured with a high-precision redundant ballistic speed measurement system. In eight out of ten weapons, the muzzle energy increased significantly when the pellet seater was used. The average increase in kinetic energy was 31 % (range 9-96 %). To conclude, seating the pellet even slightly deeper into the breech of spring-piston air guns might significantly alter the muzzle energy. Therefore, it is strongly recommended that this effect is taken into account when accurate and reliable measurements of air gun muzzle velocity are necessary.

  1. Air conducted and body conducted sound produced by own voice

    DEFF Research Database (Denmark)

    Hansen, Mie Østergaard


    When we speak, sound reaches our ears both through the air, from the mouth to ear, and through our body, as vibrations. The ratio between the air borne and body conducted sound has been studied in a pilot experiment where the air borne sound was eliminated by isolating the ear with a large...

  2. Auditory Effects of Multiple Impulses from a Seismic Air Gun on Bottlenose Dolphins (Tursiops truncatus). (United States)

    Schlundt, Carolyn E; Finneran, James J; Branstetter, Brian K; Trickey, Jennifer S; Bowman, Victoria; Jenkins, Keith


    Auditory thresholds were measured in three bottlenose dolphins before and after exposure to ten impulses from a seismic air gun. Thresholds were measured using behavioral and electrophysiological methods to determine the amount of temporary threshold shift induced. The results suggest that the potential for seismic surveys using air guns to cause auditory effects on dolphins may be lower than previously predicted; however, two of the three dolphins exhibited "anticipatory" behavioral changes at the highest exposure condition that suggested they were attempting to mitigate the effects of the exposures.

  3. Environment and air pollution like gun and bullet for low-income countries: war for better health and wealth. (United States)

    Zou, Xiang; Azam, Muhammad; Islam, Talat; Zaman, Khalid


    The objective of the study is to examine the impact of environmental indicators and air pollution on "health" and "wealth" for the low-income countries. The study used a number of promising variables including arable land, fossil fuel energy consumption, population density, and carbon dioxide emissions that simultaneously affect the health (i.e., health expenditures per capita) and wealth (i.e., GDP per capita) of the low-income countries. The general representation for low-income countries has shown by aggregate data that consist of 39 observations from the period of 1975-2013. The study decomposes the data set from different econometric tests for managing robust inferences. The study uses temporal forecasting for the health and wealth model by a vector error correction model (VECM) and an innovation accounting technique. The results show that environment and air pollution is the menace for low-income countries' health and wealth. Among environmental indicators, arable land has the largest variance to affect health and wealth for the next 10-year period, while air pollution exerts the least contribution to change health and wealth of low-income countries. These results indicate the prevalence of war situation, where environment and air pollution become visible like "gun" and "bullet" for low-income countries. There are required sound and effective macroeconomic policies to combat with the environmental evils that affect the health and wealth of the low-income countries.


    Energy Technology Data Exchange (ETDEWEB)

    Thorne, L. F.


    A mechanical shock actuator has been converted into an air gun capable of firing 8-inch-·diameter (20.32 cm) projectiles to velocities exceeding 1000 fps (304.8 m/ s). This new capability has been used to study the effect of impact velocity upon the energy.absorbed by crushable materials. Shockpulse data is reduced by computer techniques and test results are displayed in either tabular or graphic format by use of the C DC 6600 Calcomp plotter.

  5. Identifying Especial Skills for Air Gun Shooting in Skilled Male and Female Shooters

    Directory of Open Access Journals (Sweden)

    Valiollah Kashani


    Full Text Available The present study attempted to investigate the emergence of especial skill in shooting with air gun at two skill levels (skilled, novice. The population studied here included all male and female shooters from the city of Semnan. The study was conducted on a sample of 40 shooters, consisting of two groups of women with the mean age of 21.33±2.26 and two groups of men with the mean age of 23.44±23.44, who displayed their shooting abilities with air guns from five points (8, 9, 10, 11, 12 meters from the target. The test was conducted in 4 sets (with 15-minute rest intervals each consisting of 5 blocks of 25 with 20 shots at each point (100 shots in all. The gap between each set was the resting time of 15 minutes. A significant difference was found between the actual and predictive scores in all groups (p<0.05: the differences found between actual and predictive scores were significant at P=0.012 for skilled male shooters, P=0.023 for novice male shooters, P=0.001 for skilled female shooters, and P=0.021 for novice female shooters. These findings of this study support the emergence of especial skill in all groups of air gun shooters.

  6. Energy-dependent expansion of .177 caliber hollow-point air gun projectiles. (United States)

    Werner, Ronald; Schultz, Benno; Bockholdt, Britta; Ekkernkamp, Axel; Frank, Matthias


    Amongst hundreds of different projectiles for air guns available on the market, hollow-point air gun pellets are of special interest. These pellets are characterized by a tip or a hollowed-out shape in their tip which, when fired, makes the projectiles expand to an increased diameter upon entering the target medium. This results in an increase in release of energy which, in turn, has the potential to cause more serious injuries than non-hollow-point projectiles. To the best of the authors' knowledge, reliable data on the terminal ballistic features of hollow-point air gun projectiles compared to standard diabolo pellets have not yet been published in the forensic literature. The terminal ballistic performance (energy-dependent expansion and penetration) of four different types of .177 caliber hollow-point pellets discharged at kinetic energy levels from approximately 3 J up to 30 J into water, ordnance gelatin, and ordnance gelatin covered with natural chamois as a skin simulant was the subject of this investigation. Energy-dependent expansion of the tested hollow-point pellets was observed after being shot into all investigated target media. While some hollow-point pellets require a minimum kinetic energy of approximately 10 J for sufficient expansion, there are also hollow-point pellets which expand at kinetic energy levels of less than 5 J. The ratio of expansion (RE, calculated by the cross-sectional area (A) after impact divided by the cross-sectional area (A 0) of the undeformed pellet) of hollow-point air gun pellets reached values up of to 2.2. The extent of expansion relates to the kinetic energy of the projectile with a peak for pellet expansion at the 15 to 20 J range. To conclude, this work demonstrates that the hollow-point principle, i.e., the design-related enlargement of the projectiles' frontal area upon impact into a medium, does work in air guns as claimed by the manufacturers.

  7. Standing Sound Waves in Air with DataStudio (United States)

    Kraftmakher, Yaakov


    Two experiments related to standing sound waves in air are adapted for using the ScienceWorkshop data-acquisition system with the DataStudio software from PASCO scientific. First, the standing waves are created by reflection from a plane reflector. The distribution of the sound pressure along the standing wave is measured. Second, the resonance…

  8. [Management of penile trauma from compressed air gun in a child]. (United States)

    Girón-Vallejo, O; Zambudio, G; Ruiz-Pruneda, R; Hernindez, J P; Ruiz-Jiménez, J I


    We report on a 6-year old child with a penile injury resulting in the inclusion of a pellet in the cavernous body, by a fortuitous shot. Conservative approach with elective extraction of the bullet and cavernous body repair led to a satisfactory result, in better anatomic conditions. The patient did not have any perioperative complication. Accidents by air weapons are particularly important in children, because these weapons are erroneously considered as toys. Air gun injuries to head, neck and thorax have been often published, but these injuries are rare in the chidren genitourinary area.

  9. Extensive Air Showers: from the muonic smoking guns to the hadronic backbone

    Directory of Open Access Journals (Sweden)

    Cazon L.


    Full Text Available Extensive Air Showers are complex macroscopic objects initiated by single ultra-high energy particles. They are the result of millions of high energy reactions in the atmosphere and can be described as the superposition of hadronic and electromagnetic cascades. The hadronic cascade is the air shower backbone, and it is mainly made of pions. Decays of neutral pions initiate electromagnetic cascades, while the decays of charged pions produce muons which leave the hadronic core and travel many kilometers almost unaffected. Muons are smoking guns of the hadronic cascade: the energy, transverse momentum, spatial distribution and depth of production are key to reconstruct the history of the air shower. In this work, we overview the phenomenology of muons on the air shower and its relation to the hadronic cascade. We briefly review the experimental efforts to analyze muons within air showers and discuss possible paths to use this information.

  10. The simulation of far-field wavelets using frequency-domain air-gun array near-field wavelets

    Institute of Scientific and Technical Information of China (English)

    Song Jian-Guo; Deng Yong; Tong Xin-Xin


    Air-gun arrays are used in marine-seismic exploration. Far-field wavelets in subsurface media represent the stacking of single air-gun ideal wavelets. We derived single air-gun ideal wavelets using near-field wavelets recorded from near-field geophones and then synthesized them into far-field wavelets. This is critical for processing wavelets in marine-seismic exploration. For this purpose, several algorithms are currently used to decompose and synthesize wavelets in the time domain. If the traveltime of single air-gun wavelets is not an integral multiple of the sampling interval, the complex and error-prone resampling of the seismic signals using the time-domain method is necessary. Based on the relation between the frequency-domain phase and the time-domain time delay, we propose a method that first transforms the real near-field wavelet to the frequency domain via Fourier transforms;then, it decomposes it and composes the wavelet spectrum in the frequency domain, and then back transforms it to the time domain. Thus, the resampling problem is avoided and single air-gun wavelets and far-field wavelets can be reliably derived. The effect of ghost reflections is also considered, while decomposing the wavelet and removing the ghost reflections. Modeling and real data processing were used to demonstrate the feasibility of the proposed method.

  11. A Comparative Study of Sound Speed in Air at Room Temperature between a Pressure Sensor and a Sound Sensor (United States)

    Amrani, D.


    This paper deals with the comparison of sound speed measurements in air using two types of sensor that are widely employed in physics and engineering education, namely a pressure sensor and a sound sensor. A computer-based laboratory with pressure and sound sensors was used to carry out measurements of air through a 60 ml syringe. The fast Fourier…

  12. Air-borne sound generated by sea waves. (United States)

    Bolin, Karl; Åbom, Mats


    This paper describes a semi-empiric model and measurements of air-borne sound generated by breaking sea waves. Measurements have been performed at the Baltic Sea. Shores with different slopes and sediment types have been investigated. Results showed that the sound pressure level increased from 60 dB at 0.4 m wave height to 78 dB at 2.0 m wave height. The 1/3 octave spectrum was dependent on the surf type. A scaling model based on the dissipated wave power and a surf similarity parameter is proposed and compared to measurements. The predictions show satisfactory agreement to the measurements.

  13. 40 CFR 81.32 - Puget Sound Intrastate Air Quality Control Region. (United States)


    ... Quality Control Regions § 81.32 Puget Sound Intrastate Air Quality Control Region. The Puget Sound Intrastate Air Quality Control Region (Washington) consists of the territorial area encompassed by the... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Puget Sound Intrastate Air...

  14. Improving Forecast Skill by Assimilation of AIRS Temperature Soundings (United States)

    Susskind, Joel; Reale, Oreste


    AIRS was launched on EOS Aqua on May 4, 2002, together with AMSU-A and HSB, to form a next generation polar orbiting infrared and microwave atmospheric sounding system. The primary products of AIRS/AMSU-A are twice daily global fields of atmospheric temperature-humidity profiles, ozone profiles, sea/land surface skin temperature, and cloud related parameters including OLR. The AIRS Version 5 retrieval algorithm, is now being used operationally at the Goddard DISC in the routine generation of geophysical parameters derived from AIRS/AMSU data. A major innovation in Version 5 is the ability to generate case-by-case level-by-level error estimates delta T(p) for retrieved quantities and the use of these error estimates for Quality Control. We conducted a number of data assimilation experiments using the NASA GEOS-5 Data Assimilation System as a step toward finding an optimum balance of spatial coverage and sounding accuracy with regard to improving forecast skill. The model was run at a horizontal resolution of 0.5 deg. latitude X 0.67 deg longitude with 72 vertical levels. These experiments were run during four different seasons, each using a different year. The AIRS temperature profiles were presented to the GEOS-5 analysis as rawinsonde profiles, and the profile error estimates delta (p) were used as the uncertainty for each measurement in the data assimilation process. We compared forecasts analyses generated from the analyses done by assimilation of AIRS temperature profiles with three different sets of thresholds; Standard, Medium, and Tight. Assimilation of Quality Controlled AIRS temperature profiles significantly improve 5-7 day forecast skill compared to that obtained without the benefit of AIRS data in all of the cases studied. In addition, assimilation of Quality Controlled AIRS temperature soundings performs better than assimilation of AIRS observed radiances. Based on the experiments shown, Tight Quality Control of AIRS temperature profile performs best

  15. BOREAS AFM-2 Wyoming King Air 1994 Aircraft Sounding Data (United States)

    Kelly, Robert D.; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Smith, David E. (Technical Monitor)


    The BOREAS AFM-2 team used the University of Wyoming King Air aircraft during IFCs 1, 2, and 3 in 1994 to collected pass-by-pass fluxes (and many other statistics) for the large number of level (constant altitude), straight-line passes used in a variety of flight patterns over the SSA and NSA and areas along the transect between these study areas. The data described here form a second set, namely soundings that were incorporated into nearly every research flight by the King Air in 1994. These soundings generally went from near the surface to above the inversion layer. Most were flown immediately after takeoff or immediately after finishing the last flux pattern of that particular day's flights. The parameters that were measured include wind direction, wind speed, west wind component (u), south wind component (v), static pressure, air dry bulb temperature, potential temperature, dewpoint, temperature, water vapor mixing ratio, and CO2 concentration. Data on the aircraft's location, attitude, and altitude during data collection are also provided. These data are stored in tabular ASCH files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  16. Sound reduction of air compressors using a systematic approach (United States)

    Moylan, Justin Tharp

    The noise emitted by portable electric air compressors can often be a nuisance or potentially hazardous to the operator or others nearby. Therefore, reducing the noise of these air compressors is desired. This research focuses on compressors with a reciprocating piston design as this is the most common type of pump design for portable compressors. An experimental setup was developed to measure the sound and vibration of the air compressors, including testing inside a semi-anechoic chamber. The design of a quiet air compressor was performed in four stages: 1) Teardown and benchmarking of air compressors, 2) Identification and isolation of noise sources, 3) Development of individual means to quiet noise sources, 4) Selection and testing of integrated solutions. The systematic approach and results for each of these stages will be discussed. Two redesigned solutions were developed and measured to be approximately 65% quieter than the previous unmodified compressor. An additional analysis was performed on the solutions selected by the participants involved in the selection process. This analysis involved determining which of the design criteria each participant considered most important when selecting solutions. The results from each participant were then compared to their educational background and experience and correlations were identified. The correlations discovered suggest that educational background and experience may be key determinants for the preference models developed.

  17. Homemade Firearm Suicide With Dumbbell Pipe Triggering by an Air-Compressed Gun: Case Report and Review of Literature. (United States)

    Le Garff, Erwan; Delannoy, Yann; Mesli, Vadim; Berthezene, Jean Marie; Morbidelli, Philippe; Hédouin, Valéry


    Firearm suicides are frequent and well described in the forensic literature, particularly in Europe and the United States. However, the use of homemade and improvised firearms is less well described. The present case reports a suicide with an original improvised gun created using an air-compressed pellet gun and a dumbbell pipe. The aims of this study were to describe the scene, the external examination of the corpse, the body scan, and the autopsy; to understand the mechanism of death; and to compare the results with a review of the forensic literature to highlight the epidemiology of homemade firearm use, the tools used for homemade and improvised firearms in suicides versus homicides, and the manners in which homemade firearms are used (homicide or suicide, particularly in complex suicide cases).

  18. Gun Play (United States)

    Mechling, Jay


    Biology and the particular gun culture of the United States come together to explain the persistent and powerful attraction of American boys to both real guns and toy guns. The 1990s saw adults begin to conflate "the gun problem" with "the boy problem," sparking attempts (largely failed) to banish toy guns from homes and…

  19. Injury risk of nonpowder guns. (United States)

    Laraque, Danielle


    Nonpowder guns (ball-bearing [BB] guns, pellet guns, air rifles, paintball guns) continue to cause serious injuries to children and adolescents. The muzzle velocity of these guns can range from approximately 150 ft/second to 1200 ft/second (the muzzle velocities of traditional firearm pistols are 750 ft/second to 1450 ft/second). Both low- and high-velocity nonpowder guns are associated with serious injuries, and fatalities can result from high-velocity guns. A persisting problem is the lack of medical recognition of the severity of injuries that can result from these guns, including penetration of the eye, skin, internal organs, and bone. Nationally, in 2000, there were an estimated 21840 (coefficient of variation: 0.0821) injuries related to nonpowder guns, with approximately 4% resulting in hospitalization. Between 1990 and 2000, the US Consumer Product Safety Commission reported 39 nonpowder gun-related deaths, of which 32 were children younger than 15 years. The introduction of high-powered air rifles in the 1970s has been associated with approximately 4 deaths per year. The advent of war games and the use of paintball guns have resulted in a number of reports of injuries, especially to the eye. Injuries associated with nonpowder guns should receive prompt medical management similar to the management of firearm-related injuries, and nonpowder guns should never be characterized as toys.

  20. An Inexpensive and Versatile Version of Kundt's Tube for Measuring the Speed of Sound in Air (United States)

    Papacosta, Pangratios; Linscheid, Nathan


    Experiments that measure the speed of sound in air are common in high schools and colleges. In the Kundt's tube experiment, a horizontal air column is adjusted until a resonance mode is achieved for a specific frequency of sound. When this happens, the cork dust in the tube is disturbed at the displacement antinode regions. The location of the…

  1. Numerical Investigation of Transmission of Low Frequency Sound Through a Smooth Air-water Interface

    Institute of Scientific and Technical Information of China (English)

    Parviz Ghadimi; Alireza Bolghasi; Mohammad A Feizi Chekab; Rahim Zamanian


    It is the traditional belief that sound transmission from water to the air is very weak due to a large contrast between air and water impedances. Recently, the enhanced sound transmission and anomalous transparency of air-water interface have been introduced. Anomalous transparency of air-water interface states that the sound generated by a submerged shallow depth monopole point source localized at depths less than 1/10 sound wavelength, can be transmitted into the air with omni-directional pattern. The generated sound has 35 times higher power compared to the classical ray theory prediction. In this paper, sound transmission through air-water interface for a localized underwater shallow depth source is examined. To accomplish this, two-phase coupled Helmholtz wave equations in two-phase media of air-water are solved by the commercial finite element based COMSOL Multiphysics software. Ratios of pressure amplitudes of different sound sources in two different underwater and air coordinates are computed and analyzed against non-dimensional ratio of the source depth (D) to the sound wavelength (λ). The obtained results are compared with the experimental data and good agreement is displayed.

  2. Numerical study on sound vibration of an air-reed instrument with compressible LES

    CERN Document Server

    Miyamoto, Masataka; Takahashi, Kin'ya; Takami, Toshiya; Kobayashi, Taizo; Nishida, Akira; Aoyagi, Mutsumi


    Acoustic mechanics of air-reed instruments is investigated numerically with compressible Large-eddy simulation (LES). Taking a two dimensional air-reed instrument model, we have succeeded in reproducing sound oscillations excited in the resonator and have studied the characteristic feature of air-reed instruments, i.e., the relation of the sound frequency with the jet velocity described by the semi-empirical theory developed by Cremer & Ising, Coltman and other authors based on experimental results.

  3. Characteristics of aerodynamic sound sources generated by coiled wires in a uniform air-flow (United States)

    Matsumoto, H.; Nishida, K.; Saitoh, K.


    This study deals experimentally with aerodynamic sounds generated by coiled wires in a uniform air-flow. The coiled wire is a model of the hair dryer's heater. In the experiment, the effects of the coil diameter D, wire diameter d and coil spacing s of the coiled wire on the aerodynamic sound have been clarified. The results of frequency analyses of the aerodynamic sounds show that an Aeolian sound is generated by the coiled wire, when s/d is larger than 1. Also the peak frequencies of Aeolian sounds generated by the coiled wires are higher than the ones generated by a straight cylinder having the same diameter d. To clarify the characteristics of the aerodynamic sound sources, the directivity of the aerodynamic sound generated by the coiled wire has been examined, and the coherent function between the velocity fluctuation around the coiled wire and the aerodynamic sound has been calculated. Moreover, the band overall value of coherent output power between the sound and the velocity fluctuations has been calculated. This method has clarified the sound source region of the Aeolian sound generated by the coiled wire. These results show that the Aeolian sound is generated by the arc part of the coiled wire, which is located in the upstream side of the air-flow.

  4. Highly efficient isolation of waterborne sound by an air-sealed metasurface

    CERN Document Server

    Bai, Xiaoxue; Wen, Xinhua; Peng, Shasha; Ke, Manzhu; Liu, Zhengyou


    Underwater sound isolation has been a long-standing fundamental issue in industry and military fields. Starting from a simple theoretical model, here an air-sealed metasurface is proposed to overcome this problem. Comparing with the sample without filling air, the effective impedance of the air-sealed one is greatly reduced and strikingly mismatch with water, accompanying another merit of low sound speed. Deeply suppressed sound transmission (~10-5) through such a metasurface is observed experimentally over a wide range of ultrasonic frequencies and incident angles.

  5. Research on Ocean Seismic Prospecting Based on the Air Gun Array%基于气枪阵列的海洋地震勘探研究

    Institute of Scientific and Technical Information of China (English)



    简要介绍了海洋地震勘探基本原理,提出了气枪阵列组合的两种设计方法,并进行了详细描述。然后针对影响气枪阵列激发效果的多个因素进行了具体阐述,为气枪阵列的具体设计提供了参考;最后对气枪阵列的悬挂方式进行了分析说明。%The paper simply explained the work principles of Ocean Seismic Prospecting, advanced two design methods about air gun array, and particular description of the ways. Then emphases expatiate some influence factors of the fire effect for air gun array, it can provide reference for the design of air gun array and explain the hanging ways of the air gun array.

  6. A review of research progress in air-to-water sound transmission (United States)

    Peng, Zhao-Hui; Zhang, Ling-Shan


    International and domestic research progress in theory and experiment and applications of the air-to-water sound transmission are presented in this paper. Four classical numerical methods of calculating the underwater sound field generated by an airborne source, i.e., the ray theory, the wave solution, the normal-mode theory and the wavenumber integration approach, are introduced. Effects of two special conditions, i.e., the moving airborne source or medium and the rough air-water interface, on the air-to-water sound transmission are reviewed. In experimental studies, the depth and range distributions of the underwater sound field created by different kinds of airborne sources in near-field and far-field, the longitudinal horizontal correlation of underwater sound field and application methods for inverse problems are reviewed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11434012 and 11674349).

  7. Changes in Anatomical Features, Air Permeability and Sound Absorption Capability of Wood Induced by Delignification Treatment


    Kang, Chunwon; Kang, Wook; MATSUMURA, Junji; Oda, KazuYuki


    To estimate the possibility of improving the sound absorption capability of wood by delignification treatment, the changes in anatomical features on the cross sectional surface, air permeability in the longitudinal direction and sound absorption capability of wood were evaluated. The intercellular substance gushed out and numerous small cracks were formed on the surface of the delignificated wood. Delignification treatment improved the air permeability of the wood in the longitudinal directio...

  8. Gun Safety (United States)

    Many U.S. households have guns, but they can cause harm if not handled properly. Here are some things you can do to keep yourself and ... safe: Teach children that they shouldn't touch guns and that if they see a gun, to ...

  9. Magnetic Ignition of Pulsed Gas Discharges in Air of Low Pressure in a Coaxial Plasma Gun (United States)

    Thom, Karlheinz; Norwood, Joseph, Jr.


    The effect of an axial magnetic field on the breakdown voltage of a coaxial system of electrodes has been investigated by earlier workers. For low values of gas pressure times electrode spacing, the breakdown voltage is decreased by the application of the magnetic field. The electron cyclotron radius now assumes the role held by the mean free path in nonmagnetic discharges and the breakdown voltage becomes a function of the magnetic flux density. In this paper the dependence of the formative time lag as a function of the magnetic flux density is established and the feasibility of using a magnetic field for igniting high-voltage, high-current discharges is shown through theory and experiment. With a 36 microfarad capacitor bank charged to 48,000 volts, a peak current of 1.3 x 10( exp 6) amperes in a coaxial type of plasma gun was achieved with a current rise time of only 2 microseconds.

  10. Investigating the impact of noise incidence angle on the sound insulation of a supply air window

    DEFF Research Database (Denmark)

    Hansen, Morten B.; Tambo, Torben


    for the highest frequencies are less than the sound insulation of the same window measured in the laboratory. The aim of this paper is through simulations in the geometric acoustic simulation software ODEON, to investigate the impact of noise incidence angle on the sound insulation of the Supply Air Window...... in the receiving room ceiling, have been simulated and show a general improvement of the sound reduction index from 500 Hz and above, and an improvement of ~3-4 dB at 2 kHz, in relation to the noise angle ofindidence.......The Danish Environmental Agency introduced in 2007 a guideline “Noise from roads”, in which noise limits for open windows were introduced. This guideline has led to investigations of open windows with good sound insulation, and among one of these windows are the “Supply Air Window”. Prior sound...

  11. Sound

    CERN Document Server

    Robertson, William C


    Muddled about what makes music? Stuck on the study of harmonics? Dumbfounded by how sound gets around? Now you no longer have to struggle to teach concepts you really don t grasp yourself. Sound takes an intentionally light touch to help out all those adults science teachers, parents wanting to help with homework, home-schoolers seeking necessary scientific background to teach middle school physics with confidence. The book introduces sound waves and uses that model to explain sound-related occurrences. Starting with the basics of what causes sound and how it travels, you'll learn how musical instruments work, how sound waves add and subtract, how the human ear works, and even why you can sound like a Munchkin when you inhale helium. Sound is the fourth book in the award-winning Stop Faking It! Series, published by NSTA Press. Like the other popular volumes, it is written by irreverent educator Bill Robertson, who offers this Sound recommendation: One of the coolest activities is whacking a spinning metal rod...

  12. A study on the sound quality evaluation model of mechanical air-cleaners

    DEFF Research Database (Denmark)

    Ih, Jeong-Guon; Jang, Su-Won; Jeong, Cheol-Ho;


    of an immediate cleaning of pollutants. In this context, it is important to evaluate and design the air-cleaner noise to satisfy such contradictory expectations from the customers. In this study, a model for evaluating the sound quality of air-cleaners of mechanical type was developed based on objective...... perceptive descriptor. Annoyance and performance indices of air-cleaners were modeled from the subjective responses of the juries and the measured sound quality metrics: loudness, sharpness, roughness, and fluctuation strength. The multiple regression method was employed to generate sound quality evaluation...... models. Using the developed indices, sound quality of the measured data was evaluated and compared with the subjective data. The difference between predicted and tested scores was less than 0.5 points. © 2009 by ASME....

  13. Sound

    CERN Document Server


    Sound has the power to soothe, excite, warn, protect, and inform. Indeed, the transmission and reception of audio signals pervade our daily lives. Readers will examine the mechanics and properties of sound and provides an overview of the "interdisciplinary science called acoustics." Also covered are functions and diseases of the human ear.

  14. Sound speed in air-filled sand and 03ine shallow-layer sandy sediments

    Institute of Scientific and Technical Information of China (English)

    QIAN Zuwen


    Based on the author's theory for acoustic propagation in granular media and by employing the extinction theorem, the sound speed formulae in these media were derived. The numerical computations of sound speed in 03ine sediments and air-filled sand were carried out, and the results demonstrated that under the normal atmosphere the sound speed in air- filled sand is lower than the sound speed in the air. The numerical results also indicated that the influence of scattering interaction between the grains upon the sound speed in the 03ine shallow-layer sandy sediments has to be taken into account; however, the influence of the viscous-wave interaction can be neglected. The theoretical results obtained from the rigid-granular model seem to match the measured data better than from the elastic-granular model, even the latter model fits better for the real situation, indicating further measurements are necessary in order to gain an insight into this problem thoroughly. Through an analysis of experimental data published in journals a conclusion can be drawn that the theory of granular media is suited to deal with the problems of the sound propagation in air-filled sand better than the theory of porous media.

  15. Electromagnetic Gun

    Institute of Scientific and Technical Information of China (English)


    In the early 14th century,Europeons used guns in battle for the first time. The secret was gunpowder,a volatile mixture of chemicals that exploded when lit. Since then,all guns have relied on gunpowder or other chemical propellants.

  16. Improved Temperature Sounding and Quality Control Methodology Using AIRS/AMSU Data: The AIRS Science Team Version 5 Retrieval Algorithm (United States)

    Susskind, Joel; Blaisdell, John M.; Iredell, Lena; Keita, Fricky


    This paper describes the AIRS Science Team Version 5 retrieval algorithm in terms of its three most significant improvements over the methodology used in the AIRS Science Team Version 4 retrieval algorithm. Improved physics in Version 5 allows for use of AIRS clear column radiances in the entire 4.3 micron CO2 absorption band in the retrieval of temperature profiles T(p) during both day and night. Tropospheric sounding 15 micron CO2 observations are now used primarily in the generation of clear column radiances .R(sub i) for all channels. This new approach allows for the generation of more accurate values of .R(sub i) and T(p) under most cloud conditions. Secondly, Version 5 contains a new methodology to provide accurate case-by-case error estimates for retrieved geophysical parameters and for channel-by-channel clear column radiances. Thresholds of these error estimates are used in a new approach for Quality Control. Finally, Version 5 also contains for the first time an approach to provide AIRS soundings in partially cloudy conditions that does not require use of any microwave data. This new AIRS Only sounding methodology, referred to as AIRS Version 5 AO, was developed as a backup to AIRS Version 5 should the AMSU-A instrument fail. Results are shown comparing the relative performance of the AIRS Version 4, Version 5, and Version 5 AO for the single day, January 25, 2003. The Goddard DISC is now generating and distributing products derived using the AIRS Science Team Version 5 retrieval algorithm. This paper also described the Quality Control flags contained in the DISC AIRS/AMSU retrieval products and their intended use for scientific research purposes.

  17. Measurement of sound absorption in the air. [data procesing (United States)

    Meredith, R.; Badavi, F.; Becher, J.


    The large temperature gradient in each section of the resonance tube resulting from the liquid nitrogen coolant necessitated a design modification to the cooling system. A timer and four solenoid valves were installed so that the coolant flow can be reversed periodically. The hardware and software for controlling the analog to digital converter and conversion rate were completed, and the system is operational. A duty cycle control circit was implemented so that on the sixteenth conversion a relay shuts off the vibration exciter used to generate the sound wave. Thus the starting point of each decay curve is exactly known. This information is necessary for evaluating the g digital decay information. The data acquisition and digital decay evaluation programs are described.

  18. Modeling the ascent of sounding balloons: derivation of the vertical air motion

    Directory of Open Access Journals (Sweden)

    A. Gallice


    Full Text Available A new model to describe the ascent of sounding balloons in the troposphere and lower stratosphere (up to ~30–35 km altitude is presented. Contrary to previous models, detailed account is taken of both the variation of the drag coefficient with altitude and the heat imbalance between the balloon and the atmosphere. To compensate for the lack of data on the drag coefficient of sounding balloons, a reference curve for the relationship between drag coefficient and Reynolds number is derived from a dataset of flights launched during the Lindenberg Upper Air Methods Intercomparisons (LUAMI campaign. The transfer of heat from the surrounding air into the balloon is accounted for by solving the radial heat diffusion equation inside the balloon. The potential applications of the model include the forecast of the trajectory of sounding balloons, which can be used to increase the accuracy of the match technique, and the derivation of the air vertical velocity. The latter is obtained by subtracting the ascent rate of the balloon in still air calculated by the model from the actual ascent rate. This technique is shown to provide an approximation for the vertical air motion with an uncertainty error of 0.5 m s−1 in the troposphere and 0.2 m s−1 in the stratosphere. An example of extraction of the air vertical velocity is provided in this paper. We show that the air vertical velocities derived from the balloon soundings in this paper are in general agreement with small-scale atmospheric velocity fluctuations related to gravity waves, mechanical turbulence, or other small-scale air motions measured during the SUCCESS campaign (Subsonic Aircraft: Contrail and Cloud Effects Special Study in the orographically unperturbed mid-latitude middle troposphere.

  19. Borehole-explosion and air-gun data acquired in the 2011 Salton Seismic Imaging Project (SSIP), southern California: description of the survey (United States)

    Rose, Elizabeth J.; Fuis, Gary S.; Stock, Joann M.; Hole, John A.; Kell, Annie M.; Kent, Graham; Driscoll, Neal W.; Goldman, Mark; Reusch, Angela M.; Han, Liang; Sickler, Robert R.; Catchings, Rufus D.; Rymer, Michael J.; Criley, Coyn J.; Scheirer, Daniel S.; Skinner, Steven M.; Slayday-Criley, Coye J.; Murphy, Janice M.; Jensen, Edward G.; McClearn, Robert; Ferguson, Alex J.; Butcher, Lesley A.; Gardner, Max A.; Emmons, Iain; Loughran, Caleb L.; Svitek, Joseph R.; Bastien, Patrick C.; Cotton, Joseph A.; Croker, David S.; Harding, Alistair J.; Babcock, Jeffrey M.; Harder, Steven H.; Rosa, Carla M.


    detailed images we need for earthquake hazard assessment. Air gun bursts, generated in the Salton Sea along extensions of our onshore seismic lines, also were utilized as sound-wave sources. Temporary deployments of portable land seismometers, as well as ocean-bottom seismometers (OBSs) on the floor of the Salton Sea, recorded the energy from the land shots and air gun bursts. SSIP is similar to the Los Angeles Regional Seismic Experiments of 1994 and 1999 (LARSE I and II, respectively; Murphy and others, 1996; Fuis and others, 2001). The LARSE surveys demonstrated that the USGS and collaborators can safely and effectively conduct seismic imaging surveys in urban and nonurban areas, on lands owned and/or managed by many different types of agencies and entities. Information was produced that could not have been obtained any other way, and this information was key to changing the leading ideas about earthquake hazards at that time in the Los Angeles region. These surveys produced no significant environmental impact or damage to structures, and they did not trigger earthquakes.

  20. Illustrations and Supporting Texts for Sound Standing Waves of Air Columns in Pipes in Introductory Physics Textbooks (United States)

    Zeng, Liang; Smith, Chris; Poelzer, G. Herold; Rodriguez, Jennifer; Corpuz, Edgar; Yanev, George


    In our pilot studies, we found that many introductory physics textbook illustrations with supporting text for sound standing waves of air columns in open-open, open-closed, and closed-closed pipes inhibit student understanding of sound standing wave phenomena due to student misunderstanding of how air molecules move within these pipes. Based on…

  1. An Undergraduate Experiment for the Measurement of the Speed of Sound in Air: Phenomena and Discussion (United States)

    Yang, Hujiang; Zhao, Xiaohong; Wang, Xin; Xiao, Jinghua


    In this paper, we present and discuss some phenomena in an undergraduate experiment for the measurement of the speed of sound in air. A square wave distorts when connected to a piezoelectric transducer. Moreover, the amplitude of the receiving signal varies with the driving frequency. Comparing with the Gibbs phenomenon, these phenomena can be…

  2. Sound transmission through finite lightweight multilayered structures with thin air layers. (United States)

    Dijckmans, A; Vermeir, G; Lauriks, W


    The sound transmission loss (STL) of finite lightweight multilayered structures with thin air layers is studied in this paper. Two types of models are used to describe the vibro-acoustic behavior of these structures. Standard transfer matrix method assumes infinite layers and represents the plane wave propagation in the layers. A wave based model describes the direct sound transmission through a rectangular structure placed between two reverberant rooms. Full vibro-acoustic coupling between rooms, plates, and air cavities is taken into account. Comparison with double glazing measurements shows that this effect of vibro-acoustic coupling is important in lightweight double walls. For infinite structures, structural damping has no significant influence on STL below the coincidence frequency. In this frequency region, the non-resonant transmission or so-called mass-law behavior dominates sound transmission. Modal simulations suggest a large influence of structural damping on STL. This is confirmed by experiments with double fiberboard partitions and sandwich structures. The results show that for thin air layers, the damping induced by friction and viscous effects at the air gap surfaces can largely influence and improve the sound transmission characteristics.

  3. Sound Hole Sound

    CERN Document Server

    Politzer, David


    The volume of air that goes in and out of a musical instrument's sound hole is related to the sound hole's contribution to the volume of the sound. Helmholtz's result for the simplest case of steady flow through an elliptical hole is reviewed. Measurements on multiple holes in sound box geometries and scales relevant to real musical instruments demonstrate the importance of a variety of effects. Electric capacitance of single flat plates is a mathematically identical problem, offering an alternate way to understand the most important of those effects. The measurements also confirm and illuminate aspects of Helmholtz's "bottle" resonator model as applied to musical instrument sound boxes and sound holes.

  4. Gun Control, Gun Ownership, and Suicide Prevention. (United States)

    Lester, David


    Explored relationship between the extent of gun ownership and the strictness of gun control laws to suicide and homicide rates in the nine major geographic regions of the United States. Found gun ownership, rather than the strictness of gun control laws, was the strongest correlate of the rates of suicide and homicide by guns. (Author)

  5. Application of Air Gun in Coal Bunker of Coke Oven%空气炮在焦炉煤仓的应用

    Institute of Scientific and Technical Information of China (English)

    王晓琴; 曹春娟; 王昆鹏


    To solve the bad influence caused by the coal blockage in coal bunker of coke oven during coals' falling on coking process, the installation methods and application of air gun in coal bunker was put forward according to aerodynamics principle. It was proposed that air gun was added in the coal bunker of coke oven and made use of potential energy that compressed air (0. 4~0. 8 Mpa) released abruptly to produce the powerful shock-wave. As a result, the arching and the cohering coal materials were recovered gravity flow. These methods made the blockage disappear and achieved a continuous operation for coal loading. Air gun should be designed and installed as spirals in each coal bunker and the specific demand during the operation was introduced as well. The result shows that the application of air gun in coal bunker of coke oven can not only reduce labor intensity,protect equipment, improve coke quality, but also achieve a safe production.%针对焦炉煤仓在下煤时出现的易堵塞现象对焦炉生产造成的诸多不利影响,根据空气动力学原理,提出了在焦炉1煤仓增设空气炮,利用压缩空气(0.4~0.8 MPa)突然释放的势能,产生强烈冲击波,使起拱的或粘着的煤料再次恢复重力流动,使堵塞消除,实现装煤连续作业.介绍了每个煤仓应按螺旋上升布置空气炮的安装要求,以及空气炮在使用过程中的具体要求.结果表明:在焦炉煤仓使用空气炮不仅可以降低操作人员的劳动强度,保护设备,而且可以改善焦炭质量,并实现焦炉安全生产.

  6. Modeling the ascent of sounding balloons: derivation of the vertical air motion

    Directory of Open Access Journals (Sweden)

    A. Gallice


    Full Text Available A new model to describe the ascent of sounding balloons in the troposphere and lower stratosphere (up to ∼30–35 km altitude is presented. Contrary to previous models, detailed account is taken of both the variation of the drag coefficient with altitude and the heat imbalance between the balloon and the atmosphere. To compensate for the lack of data on the drag coefficient of sounding balloons, a reference curve for the relationship between drag coefficient and Reynolds number is derived from a dataset of flights launched during the Lindenberg Upper Air Methods Intercomparisons (LUAMI campaign. The transfer of heat from the surrounding air into the balloon is accounted for by solving the radial heat diffusion equation inside the balloon. In its present state, the model does not account for solar radiation, i.e. it is only able to describe the ascent of balloons during the night. It could however be adapted to also represent daytime soundings, with solar radiation modeled as a diffusive process. The potential applications of the model include the forecast of the trajectory of sounding balloons, which can be used to increase the accuracy of the match technique, and the derivation of the air vertical velocity. The latter is obtained by subtracting the ascent rate of the balloon in still air calculated by the model from the actual ascent rate. This technique is shown to provide an approximation for the vertical air motion with an uncertainty error of 0.5 m s−1 in the troposphere and 0.2 m s−1 in the stratosphere. An example of extraction of the air vertical velocity is provided in this paper. We show that the air vertical velocities derived from the balloon soundings in this paper are in general agreement with small-scale atmospheric velocity fluctuations related to gravity waves, mechanical turbulence, or other small-scale air motions measured during the SUCCESS campaign (Subsonic Aircraft: Contrail and Cloud Effects

  7. Anomalous transparency of water-air interface for low-frequency sound

    CERN Document Server

    Godin, O A


    Sound transmission through water-air interface is normally weak because of a strong mass density contrast. Here we show that the transparency of the interface increases dramatically at low frequencies. Rather counterintuitively, almost all acoustic energy emitted by a sufficiently shallow monopole source under water is predicted to be radiated into atmosphere. Physically, increased transparency at lower frequencies is due to the increasing role of inhomogeneous waves and a destructive interference of direct and surface-reflected waves under water. The phenomenon of anomalous transparency has significant implications for acoustic communication across the water-air interface, generation of ambient noise, and detection of underwater explosions.

  8. Spectrometer gun (United States)

    Waechter, David A.; Wolf, Michael A.; Umbarger, C. John


    A hand-holdable, battery-operated, microprocessor-based spectrometer gun includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  9. Comments for the Cape Wind Associates, LLC, Horseshoe Shoal, Nantucket Sound (Offshore Renewable Energy Project/OCS Air Permit) (United States)

    List of comments for the Cape Wind Associates, LLC, Horseshoe Shoal, Nantucket Sound (Offshore Renewable Energy Project/OCS Air Permit: Massachusetts Plan Approval including nonattainment NSR Appendix A requirements).

  10. Gun Safety (For Parents) (United States)

    ... Old Feeding Your 1- to 2-Year-Old Gun Safety KidsHealth > For Parents > Gun Safety Print A ... unloaded, and the ammunition should be stored separately. Guns and Pretend Play Allowing kids to play with ...

  11. Computer simulation tool for predicting sound propagation in air-filled tubes with acoustic impedance discontinuities. (United States)

    Albors, Gabriel O; Kyle, Aaron M; Wodicka, George R; Juan, Eduardo J


    A computer tool, based on an acoustic transmission line model, was developed for modeling and predicting sound propagation and reflections in cascaded tube segments. This subroutine considered the number of interconnected tubes, their dimensions and wall properties, as well as medium properties to create a network of cascaded transmission line model segments, from which the impulse response of the network was estimated. Acoustic propagation was examined in air-filled cascaded tube networks and model predictions were compared to measured acoustic pulse responses. The model was able to accurately predict the location and morphology of reflections. The developed code proved to be a useful design tool for applications such as the guidance of catheters through compliant air-filled biological conduits.

  12. Combination sound and vibration isolation curb for rooftop air-handling systems (United States)

    Paige, Thomas S.


    This paper introduces the new Model ESSR Sound and Vibration Isolation Curb manufactured by Kinetics Noise Control, Inc. This product was specially designed to address all of the common transmission paths associated with noise and vibration sources from roof-mounted air-handling equipment. These include: reduction of airborne fan noise in supply and return air ductwork, reduction of duct rumble and breakout noise, reduction of direct airborne sound transmission through the roof deck, and reduction of vibration and structure-borne noise transmission to the building structure. Upgrade options are available for increased seismic restraint and wind-load protection. The advantages of this new system over the conventional approach of installing separate duct silencers in the room ceiling space below the rooftop unit are discussed. Several case studies are presented with the emphasis on completed projects pertaining to classrooms and school auditorium applications. Some success has also been achieved by adding active noise control components to improve low-frequency attenuation. This is an innovative product designed for conformance with the new classroom acoustics standard ANSI S12.60.

  13. Improved DC Gun Insulator

    Energy Technology Data Exchange (ETDEWEB)

    M.L. Neubauer, K.B. Beard, R. Sah, C. Hernandez-Garcia, G. Neil


    Many user facilities such as synchrotron light sources and free electron lasers require accelerating structures that support electric fields of 10-100 MV/m, especially at the start of the accelerator chain where ceramic insulators are used for very high gradient DC guns. These insulators are difficult to manufacture, require long commissioning times, and have poor reliability, in part because energetic electrons bury themselves in the ceramic, creating a buildup of charge and causing eventual puncture. A novel ceramic manufacturing process is proposed. It will incorporate bulk resistivity in the region where it is needed to bleed off accumulated charge caused by highly energetic electrons. This process will be optimized to provide an appropriate gradient in bulk resistivity from the vacuum side to the air side of the HV standoff ceramic cylinder. A computer model will be used to determine the optimum cylinder dimensions and required resistivity gradient for an example RF gun application. A ceramic material example with resistivity gradient appropriate for use as a DC gun insulator will be fabricated by glazing using doping compounds and tested.

  14. Air temperature measurements based on the speed of sound to compensate long distance interferometric measurements

    Directory of Open Access Journals (Sweden)

    Astrua Milena


    Full Text Available A method to measure the real time temperature distribution along an interferometer path based on the propagation of acoustic waves is presented. It exploits the high sensitivity of the speed of sound in air to the air temperature. In particular, it takes advantage of a special set-up where the generation of the acoustic waves is synchronous with the amplitude modulation of a laser source. A photodetector converts the laser light to an electronic signal considered as reference, while the incoming acoustic waves are focused on a microphone and generate a second signal. In this condition, the phase difference between the two signals substantially depends on the temperature of the air volume interposed between the sources and the receivers. The comparison with the traditional temperature sensors highlighted the limit of the latter in case of fast temperature variations and the advantage of a measurement integrated along the optical path instead of a sampling measurement. The capability of the acoustic method to compensate the interferometric distance measurements due to air temperature variations has been demonstrated for distances up to 27 m.

  15. Assessing the air pollution carrying capacity of the northern Puget Sound region: an application of TAPAS

    Energy Technology Data Exchange (ETDEWEB)

    Wood, M.C.; Childs J.E.; Marlatt, W.E.


    The technique discussed, the Topographic Air Pollution Analysis System (TAPAS), was developed to provide valid information on the dispersion capability of the lower atmosphere in areas characterized by complex terrain features. A study was undertaken to assess the air quality (SO/sub 2/) impacts associated with energy development in the region and to determine the constraints on energy development due to regulated limitations on the amount of air quality degradation allowable in the area. The emission constraint analysis for the northern Puget Sound region indicated that total SO/sub 2/ emissions in the core area (on an annual basis) are less than half of the amount that could be tolerated in the entire core region while maintaining ambient concentrations within state and federal annual average limitations. However, comparison of source characteristics with source location and grid cell emission restrictions indicated that localized areas adjacent to the major point sources are already far in excess of the SO/sub 2/ carrying capacity. This conclusion is supported by air quality monitoring data that indicate state standard violations at several receptor locations within the study area. The annual maps of wind patterns and PI-Matrix values show areas of both good and poor dispersion characteristics under the most prevalent flow conditions.

  16. Gun ownership and social gun culture. (United States)

    Kalesan, Bindu; Villarreal, Marcos D; Keyes, Katherine M; Galea, Sandro


    We assessed gun ownership rates in 2013 across the USA and the association between exposure to a social gun culture and gun ownership. We used data from a nationally representative sample of 4000 US adults, from 50 states and District of Columbia, aged >18 years to assess gun ownership and social gun culture performed in October 2013. State-level firearm policy information was obtained from the Brady Law Center and Injury Prevention and Control Center. One-third of Americans reported owning a gun, ranging from 5.2% in Delaware to 61.7% in Alaska. Gun ownership was 2.25-times greater among those reporting social gun culture (PR=2.25, 95% CI 2.02 to 2.52) than those who did not. In conclusion, we found strong association between social gun culture and gun ownership. Gun cultures may need to be considered for public health strategies that aim to change gun ownership in the USA.

  17. Encyclopedia of Gun Control and Gun Rights. (United States)

    Utter, Glenn H.

    This reference volume provides information on gun control and gun rights, including resources on the debate surrounding the Second Amendment and individuals and organizations focused on gun issues, along with statutes, court cases, events, and publications surrounding this current topic. Highlighted are the important organizations and their…

  18. ION GUN (United States)

    Dandl, R.A.


    An ion gun is described for the production of an electrically neutral ionized plasma. The ion gun comprises an anode and a cathode mounted in concentric relationship with a narrow annulus between. The facing surfaces of the rear portions of the anode and cathode are recessed to form an annular manifold. Positioned within this manifold is an annular intermediate electrode aligned with the an nulus between the anode and cathode. Gas is fed to the manifold and an arc discharge is established between the anode and cathode. The gas is then withdrawn from the manifold through the annulus between the anode and cathode by a pressure differential. The gas is then ionized by the arc discharge across the annulus. The ionized gas is withdrawn from the annulus by the combined effects of the pressure differential and a collimating magnetic field. In a 3000 gauss magnetic field, an arc voltage of 1800 volts, and an arc current of 0.2 amp, a plasma of about 3 x 10/sup 11/ particles/cc is obtained. (AEC)

  19. ELECTRON GUN (United States)

    Christofilos, N.C.; Ehlers, K.W.


    A pulsed electron gun capable of delivering pulses at voltages of the order of 1 mv and currents of the order of 100 amperes is described. The principal novelty resides in a transformer construction which is disposed in the same vacuum housing as the electron source and accelerating electrode structure of the gun to supply the accelerating potential thereto. The transformer is provided by a plurality of magnetic cores disposed in circumferentially spaced relation and having a plurality of primary windings each inductively coupled to a different one of the cores, and a helical secondary winding which is disposed coaxially of the cores and passes therethrough in circumferential succession. Additional novelty resides in the disposition of the electron source cathode filament input leads interiorly of the transformer secondary winding which is hollow, as well as in the employment of a half-wave filament supply which is synchronously operated with the transformer supply such that the transformer is pulsed during the zero current portions of the half-wave cycle.

  20. Motor control of sound frequency in birdsong involves the interaction between air sac pressure and labial tension (United States)

    Alonso, Rodrigo; Goller, Franz; Mindlin, Gabriel B.


    Frequency modulation is a salient acoustic feature of birdsong. Its control is usually attributed to the activity of syringeal muscles, which affect the tension of the labia responsible for sound production. We use experimental and theoretical tools to test the hypothesis that for birds producing tonal sounds such as domestic canaries (Serinus canaria), frequency modulation is determined by both the syringeal tension and the air sac pressure. For different models, we describe the structure of the isofrequency curves, which are sets of parameters leading to sounds presenting the same fundamental frequencies. We show how their shapes determine the relative roles of syringeal tension and air sac pressure in frequency modulation. Finally, we report experiments that allow us to unveil the features of the isofrequency curves.


    NARCIS (Netherlands)



    Recently, several papers investigated the linear dimensional changes in dentine after air-drying. This paper pertains to weight changes, volume changes, and density changes caused by air-drying of sound and demineralized intact dentine. The densities of sound and artificially demineralized human cor

  2. 30 years of upper air soundings on board of R/V POLARSTERN (United States)

    Driemel, Amelie; Loose, Bernd; Grobe, Hannes; Sieger, Rainer; König-Langlo, Gert


    The research vessel and supply icebreaker POLARSTERN is the flagship of the Alfred-Wegener-Institut in Bremerhaven (Germany) and one of the infrastructural pillars of German Antarctic research. Since its commissioning in 1982, POLARSTERN has conducted 30 campaigns to Antarctica (157 legs, mostly austral summer), and 29 to the Arctic (94 legs, northern summer). Usually, POLARSTERN is more than 300 days per year in operation and crosses the Atlantic Ocean in a meridional section twice a year. The first radiosonde on POLARSTERN was released on the 29 December 1982, 2 days after POLARSTERN started on its maiden voyage to the Antarctic. And these daily soundings have continued up to the present. Due to the fact that POLARSTERN has reliably and regularly been providing upper air observations from data sparse regions (oceans and polar regions), the radiosonde data are of special value for researchers and weather forecast services alike. In the course of 30 years (29 December 1982 to 25 November 2012) a total of 12 378 radiosonde balloons were started on POLARSTERN. All radiosonde data can now be found at König-Langlo (2015, doi:10.1594/PANGAEA.810000). Each data set contains the directly measured parameters air temperature, relative humidity and air pressure, and the derived altitude, wind direction and wind speed. 432 data sets additionally contain ozone measurements.Although more sophisticated techniques (meteorological satellites, aircraft observation, remote-sensing systems, etc.) have nowadays become increasingly important, the high vertical resolution and quality of radiosonde data remains paramount for weather forecasts and modelling approaches.

  3. Influence of water depth on the sound generated by air-bubble vibration in the water musical instrument (United States)

    Ohuchi, Yoshito; Nakazono, Yoichi


    We have developed a water musical instrument that generates sound by the falling of water drops within resonance tubes. The instrument can give people who hear it the healing effect inherent in the sound of water. The sound produced by falling water drops arises from air- bubble vibrations. To investigate the impact of water depth on the air-bubble vibrations, we conducted experiments at varying values of water pressure and nozzle shape. We found that air-bubble vibration frequency does not change at a water depth of 50 mm or greater. Between 35 and 40 mm, however, the frequency decreases. At water depths of 30 mm or below, the air-bubble vibration frequency increases. In our tests, we varied the nozzle diameter from 2 to 4 mm. In addition, we discovered that the time taken for air-bubble vibration to start after the water drops start falling is constant at water depths of 40 mm or greater, but slower at depths below 40 mm.

  4. Guns and Violence. Current Controversies. (United States)

    Kim, Henny H., Ed.

    This book focuses on gun violence and gun control, presenting both sides of arguments about firearms ownership and gun control. Each of five chapters poses a question about gun control and provides answers for both sides of the question. The following essays are included: (1) "Gun Violence Is Becoming an Epidemic" (Bob Herbert); (2) "Gun Violence…

  5. Teen Suicide and Guns (United States)

    ... Text Size Email Print Share Teen Suicide and Guns Page Content Article Body Protect Your Teenager Many ... American teenagers commit suicide every day. Does a gun in the home increase the chance of suicide? ...

  6. Electron gun for SSRF

    Institute of Scientific and Technical Information of China (English)


    A 100 kV triode-electron-gun has been designed and manufactured for the Linac of Shanghai Synchrotron Radiation Facility (SSRF). In this paper the performance of the gun and some key components are described.

  7. Sound propagation in narrow tubes including effects of viscothermal and turbulent damping with application to charge air coolers (United States)

    Knutsson, Magnus; Åbom, Mats


    Charge air coolers (CACs) are used on turbocharged internal combustion engines to enhance the overall gas-exchange performance. The cooling of the charged air results in higher density and thus volumetric efficiency. It is also important for petrol engines that the knock margin increases with reduced charge air temperature. A property that is still not very well investigated is the sound transmission through a CAC. The losses, due to viscous and thermal boundary layers as well as turbulence, in the narrow cooling tubes result in frequency dependent attenuation of the transmitted sound that is significant and dependent on the flow conditions. Normally, the cross-sections of the cooling tubes are neither circular nor rectangular, which is why no analytical solution accounting for a superimposed mean flow exists. The cross-dimensions of the connecting tanks, located on each side of the cooling tubes, are large compared to the diameters of the inlet and outlet ducts. Three-dimensional effects will therefore be important at frequencies significantly lower than the cut-on frequencies of the inlet/outlet ducts. In this study the two-dimensional finite element solution scheme for sound propagation in narrow tubes, including the effect of viscous and thermal boundary layers, originally derived by Astley and Cummings [Wave propagation in catalytic converters: Formulation of the problem and finite element scheme, Journal of Sound and Vibration 188 (5) (1995) 635-657] is used to extract two-ports to represent the cooling tubes. The approximate solutions for sound propagation, accounting for viscothermal and turbulent boundary layers derived by Dokumaci [Sound transmission in narrow pipes with superimposed uniform mean flow and acoustic modelling of automobile catalytic converters, Journal of Sound and Vibration 182 (5) (1995) 799-808] and Howe [The damping of sound by wall turbulent shear layers, Journal of the Acoustical Society of America 98 (3) (1995) 1723-1730], are

  8. Study of far-field pressure wavelet of air-gun bubble based on p otential flow theory%基于势流理论的气枪气泡远场压力子波特性研究

    Institute of Scientific and Technical Information of China (English)

    叶亚龙; 李艳青; 张阿漫


    The study of far-field pressure wavelet of air-gun bubble is the basic research of air-gun sources. In this paper, a boundary element bubble model is established to simulate the dynamics of bubble, and an energy equivalent method is put forward to solve the bottleneck of bubble jet. In our simplified model, the bubble model takes into consideration the thermodynamic factors such as heat transfer and gas release, and the numerical results agree with the data of Nucleus software well. Based on the established model, the influence of heat transfer coefficient, air-gun firing time, and specific heat at constant volume on the pressure wavelet are studied. Finally, the three-dimensional bubble merging numerical method is put forward, which is an expansion of the axisymmetric model. Thus, the preliminary study of coherent air-gun is conducted, especially the influence of the space between two bubbles on the wavelet. This paper provides a reference for the research of air-gun.%气枪气泡的远场压力子波特性研究是研究气枪震源的基础,本文在前人研究基础上建立了三维边界元气泡动力学模型,并针对气泡射流这一技术瓶颈提出了能量等效算法。再在上述模型中加入了简化的热力学模型,考虑了气枪释放气体以及气泡传热等热力学因素,将上面模型计算结果和Nucleus软件模拟结果对比,两者符合良好,并以此为基础探讨了传热系数、气枪发射时间、气体等体比热容对气枪主要参数的影响规律。最后将轴对称气泡融合技术拓展到三维边界元模型,对相干枪进行初步研究,探讨了气枪间距对压力子波的影响规律,旨在为气枪的研究提供参考。

  9. Survey of SRF guns

    Energy Technology Data Exchange (ETDEWEB)

    Belomestnykh, S.


    Developing Superconducting RF (SRF) electron guns is an active field with several laboratories working on different gun designs. While the first guns were based on elliptic cavity geometries, Quarter Wave Resonator (QWR) option is gaining popularity. QWRs are especially well suited for producing beams with high charge per bunch. In this talk we will describe recent progress in developing both types of SRF guns. SRF guns made excellent progress in the last two years. Several guns generated beams and one, at HZDR, injected beam into an accelerator. By accomplishing this, HZDR/ELBE gun demonstrated feasibility of the SRF gun concept with a normal-conducting Cs{sub 2}Te cathode. The cathode demonstrated very good performance with the lifetime of {approx}1 year. However, for high average current/high bunch charge operation CsK{sub 2}Sb is preferred as it needs green lasers, unlike UV laser for the Cs{sub 2}Te, which makes it easier to build laser/optics systems. Other high QE photocathodes are being developed for SRF guns, most notably diamond-amplified photocathode. Several QWR guns are under development with one producing beam already. They are very promising for high bunch charge operation. The field is very active and we should expect more good results soon.

  10. Public Hearing & Comment Period Document(s) for the Cape Wind Associates, LLC, Horseshoe Shoal, Nantucket Sound (Offshore Renewable Energy Project/OCS Air Permit) (United States)

    List of public hearing & comment period document(s) for the Cape Wind Associates, LLC, Horseshoe Shoal, Nantucket Sound (Offshore Renewable Energy Project/OCS Air Permit: Massachusetts Plan Approval including nonattainment NSR Appendix A requirements).

  11. Design and application of air-gun arrays in marine seismic exploration%海上气枪震源阵列优化组合设计与应用

    Institute of Scientific and Technical Information of China (English)

    李绪宣; 王建花; 张金淼; 顾汉明


    Based on the simulation method of marine air-gun seismic source wavelet and through a large number of seismic source wavelet simulation calculations for marine multi-subarray under different air-gun array combinations, three-dimensional multi-sub-arrays and two unconventional air-gun arrays (I. E. , put the high-capacity air-gun in the middle position or arrange it in staggered form in air-gun array) that are applicable for deep-water seismic exploration are proposed in this paper. The simulated wavelet is characterized by the strong low-frequency energy, large P/B ratio and strong spectrum energy at notch points. Furthermore, we apply the optimized air-gun arrays of three-dimensional four-array combination and sixsubarray unconventional array combination to different exploration targets to conduct field seismic acquisition tests. Test results show that the proposed optimized array combination designs have good application results: they can significantly improve the performance of wavelet, so that the quality of seismic sections acquired is significantly improved, reflection characteristics of deep stratum are obvious and the basin structure and strata filling characteristics are clearly shown.%笔者基于海上气枪震源子波模拟方法,针对海上多子阵进行了大量的不同气枪阵列组合情形下的震源子波模拟试算,提出了适应深水地震勘探要求的立体多阵列和将气枪阵列的大容量气枪放置在中间位置以及交错排列两种非常规气枪阵列,所模拟的子波具有低频能量强、初泡比大、陷波点处的频谱能量强的特点.同时,把优选的立体四阵列组合和六子阵非常规阵列组合的气枪阵列在不同勘探靶区进行了野外地震采集试验,结果表明,笔者提出的优化阵列组合设计可以明显提高子波性能,所获得的地震剖面品质明显改进,深部地层的反射特征明显,清楚地展示了盆地结构、地层充填特征等,取得了良好的应用效果.

  12. Carbon Nanotube Electron Gun (United States)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)


    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  13. The sound of oscillating air jets: Physics, modeling and simulation in flute-like instruments (United States)

    de La Cuadra, Patricio

    Flute-like instruments share a common mechanism that consists of blowing across one open end of a resonator to produce an air jet that is directed towards a sharp edge. Analysis of its operation involves various research fields including fluid dynamics, aero-acoustics, and physics. An effort has been made in this study to extend this description from instruments with fixed geometry like recorders and organ pipes to flutes played by the lips. An analysis of the jet's response to a periodic excitation is the focus of this study, as are the parameters under the player's control in forming the jet. The jet is excited with a controlled excitation consisting of two loudspeakers in opposite phase. A Schlieren system is used to visualize the jet, and image detection algorithms are developed to extract quantitative information from the images. In order to study the behavior of jets observed in different flute-like instruments, several geometries of the excitation and jet shapes are studied. The obtained data is used to propose analytical models that correctly fit the observed measurements and can be used for simulations. The control exerted by the performer on the instrument is of crucial importance in the quality of the sound produced for a number of flute-like instruments. The case of the transverse flute is experimentally studied. An ensemble of control parameters are measured and visualized in order to describe some aspects of the subtle control attained by an experienced flautist. Contrasting data from a novice flautist are compared. As a result, typical values for several non-dimensional parameters that characterize the normal operation of the instrument have been measured, and data to feed simulations has been collected. The information obtained through experimentation is combined with research developed over the last decades to put together a time-domain simulation. The model proposed is one-dimensional and driven by a single physical input. All the variables in the

  14. A prediction method for aerodynamic sound produced by multiple elements in air ducts (United States)

    Mak, C. M.


    A prediction method for aerodynamic sound produced by the interaction of multiple elements in a low speed flow duct has been developed. Same as the previous works of Mak and Yang for two in-duct elements, the concept of partially coherent sound fields is adopted to formulate the sound powers produced by interaction of multiple in-duct elements at frequencies below and above the cut-on frequency of the lowest transverse duct mode. An interaction factor is finally defined as a result of a simple relationship between the sound power due to the interaction of multiple in-duct elements and that due to a single in-duct element. The present study suggests that it is possible to predict the level and spectral distribution of the additional acoustic energy produced by the interaction of multiple in-duct elements. The proposed method therefore can form a basis of a generalized prediction method for aerodynamic sound produced by multiple in-duct elements in a ventilation system.

  15. Promoting Sound Ethical Decisions in the Air Force: CGO Solutions to Air Force Moral and Ethical Lapses (United States)


    Beliefs and the Impact of Moral Distress on Conscientious Objection,” Nursing Ethics 19, no. 6 (2012): 739 25Air Force Instruction (AFI) 1-1, Air Force... Ethical Beliefs and the Impact of Moral Distress on Conscientious Objection." Nursing Ethics 19, no. 6 (2012). Department of Defense, Office of...Recent ethical and moral lapses, defined as decisions or actions not in line with the Air Force Core Values, are not isolated occurrences. Rather

  16. Guns at College. (United States)

    Miller, Matthew; Hemenway, David; Wechsler, Henry


    Surveyed undergraduate students nationwide concerning firearm possession. About 3.5% possessed working firearms. Students with guns were more likely to be male, White, or Native American; binge drink; live off-campus; and live with a spouse or significant other. Students with guns were more likely to engage in activities that put themselves and…

  17. The Missing Gun The Missing Gun

    Institute of Scientific and Technical Information of China (English)


    Ma Shan, a criminal poljceman in a remotesmall town in the southwestern Yunnan province,gets drunk at his sister’s wedding and has his three-bullet gun lost, He tries to find it stealthily but endsup in vain. He has tno choice but to report the

  18. Experiments in Sound and Structural Vibrations Using an Air-Analog Model Ducted Propulsion System (United States)


    of a circular membrane /(fromn Morse and Ingard ) University of Noire Dame Center for Flow Physics and Control I _ I Sound and Vibration Measurements...region. A detailed deri- vation of Eq. (29) is available in Morse and Ingard (1968), among others. Integration by parts allows the far field solution to...imposed by the rigid duct. A similar amplification function was introduced by Morse and Ingard (p. 320). As an example, if a harmonic monopole source were

  19. Gun Dynamics Laboratory (United States)

    Federal Laboratory Consortium — The Gun Dynamics Laboratory is a research multi-task facility, which includes two firing bays, a high bay area and a second floor laboratory space. The high bay area...

  20. Gun Control Legislation (United States)


    issue for the 111th Congress has been gun trafficking and smuggling across the Southwest border from the United States to Mexico .4 Several...committees have held hearings on gun trafficking and smuggling across the Southwest border from the United States to Mexico . In the Consolidated...emerging technology by which a firearm’s serial number is engraved microscopically with a laser onto the breech face or firing pin of a firearm. When

  1. Electromagnetic configurations of rail guns (United States)

    Fat'yanov, O. V.; Ostashev, V. E.; Lopyrev, A. N.; Ul'Yanov, A. V.


    Some problems associated with the electromagnetic acceleration of macrobodies in a rail gun are examined. An approach to the design of rail gun configurations is proposed, and some basic rail gun schemes are synthesized. The alternative rail gun schemes are compared in terms of electrode potential and stability of the electrode gap with respect to parasitic current shunting. The effect of the ohmic resistance of the electrodes and of the additional magnetization field on the spatial structure of the discharge in the rail gun channel is discussed. A classification of rail gun modifications is presented.

  2. A study on optimization of seismic air-gun array source and its application in offshore deep water%海上深水区气枪震源阵列优化组合研究与应用

    Institute of Scientific and Technical Information of China (English)

    李绪宣; 王建花; 杨凯; 张金淼


    基于海上气枪震源子波模拟方法,对海上多子阵不同气枪阵列组合的震源子波进行了大量的模拟试算,提出了适应海上深水区地震勘探要求的多子阵立体阵列组合方式和2种平面阵列优化组合模式,并对优选的立体四子阵列和平面六子阵列组合震源进行了不同勘探靶区野外地震采集试验,取得了良好的应用效果.%A lot of pilot calculations of simulation were conducted for the wavelets from various offshore air-gun array sources with multiple sub-arrays, by using the method of simulating these wavelets, and some optimized options of air-gun array source were developed, which are suitable for the seismic survey in offshore deep water, including the stereo-array source with multiple sub-arrays and two types of planar-array source. Two optimized array sources, i. e. a stereo-array source with four sub-arrays and a planar-array source with six sub-arrays, have been used in seismic acquisition tests in different deep-water areas, and their effects are quite good.

  3. Calculating Speed of Sound (United States)

    Bhatnagar, Shalabh


    Sound is an emerging source of renewable energy but it has some limitations. The main limitation is, the amount of energy that can be extracted from sound is very less and that is because of the velocity of the sound. The velocity of sound changes as per medium. If we could increase the velocity of the sound in a medium we would be probably able to extract more amount of energy from sound and will be able to transfer it at a higher rate. To increase the velocity of sound we should know the speed of sound. If we go by the theory of classic mechanics speed is the distance travelled by a particle divided by time whereas velocity is the displacement of particle divided by time. The speed of sound in dry air at 20 °C (68 °F) is considered to be 343.2 meters per second and it won't be wrong in saying that 342.2 meters is the velocity of sound not the speed as it's the displacement of the sound not the total distance sound wave covered. Sound travels in the form of mechanical wave, so while calculating the speed of sound the whole path of wave should be considered not just the distance traveled by sound. In this paper I would like to focus on calculating the actual speed of sound wave which can help us to extract more energy and make sound travel with faster velocity.

  4. Electromagnetic Guns versus Conventional Guns - a performance comparison

    NARCIS (Netherlands)

    Reus, N.M. de; Weijden, J. van der


    Performance improvement is one of the key issues of Electromagnetic gun systems compared to conventional gun systems. Due to higher muzzle velocities, the gun's fire control computer will be able to predict the target's future position more accurately because prediction time will be smaller. In this

  5. Feasibility report: Operation of light air cushion vehicle at McMurdo Sound, Antarctica (United States)

    Dibbern, J. S.


    This report explores the viability of the use of an air cushion vehicle (ACV) or hovercraft to perform logistic and scientific support in the area of McMurdo Station, Antarctica. After a review of personnel assets and facilities at McMurdo Station to support the ACV plus a reconnaissance of the five major routes selected, it appears that an air cushion vehicle in the 1 to 1 1/2 ton payload class would be of significant value to support operations. It would reduce transit times for surface vehicle traverses on the routes selected and reduce requirements for expenditure of helicopter flight time in others. Of major significance is the ability to handle passenger/shuttle requirements between the Scott Base transition and Williams Field Skiway. Use of the ACV for high frequency passenger operations would help preserve the snow road for cargo operations during periods of road deterioration.

  6. Mole gun injury. (United States)

    Pistré, V; Rezzouk, J


    A mole gun is a weapon, which is used to trap and kill moles. This report provides an overview of the state of knowledge of mole gun injuries, comparable to blast injuries caused by fireworks, explosive or gunshot. Over a 2-year period, the authors reported their experience with ten hand injuries caused by mole gun. Radial side of the hand was often concerned, particularly the thumb. The authors explain their choices in the management of such lesions. Surgery was performed primarily and a large debridement currently seemed to offer the best outcome for the patient. Blast, crush, burns and lacerations may explain the higher rate of amputation to the digits. A long period of physiotherapy, specifically of the hand, was needed before the patient could return to work. This ballistic hand trauma encountered by surgeons requires knowledge and understanding of these injuries. It should be in accordance with firearms law because of severe injuries encountered and possible lethal wounds.

  7. Unbalanced field RF electron gun (United States)

    Hofler, Alicia


    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  8. The Mystery of the Gun Turret in the Desert

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    The mystery of the gun turret in the desert began with an ingenious idea: to develop a reusable open-air line of sight diagnostic device to support LLNL’s early nuclear weapons development efforts. Obtained from the Mare Island Navy Shipyard (MINS) in January 1957, the gun turret traveled by ship to the Naval Construction Battalion base at Port Hueneme, California, and then by truck to Area 2 in the Yucca Flats valley at the Nevada Nuclear Security Site (NNSS).


    Institute of Scientific and Technical Information of China (English)

    HUANG Bing; LIU Jian-wen; BAI Jie; LI Yao-dong; GAO Shou-ting


    In this study, we derived atmospheric profiles of temperature, moisture, and ozone, along with surface emissivity, skin temperature, and surface pressure, from infrared-sounder radiances under clear sky (cloudless) condition. Clouds were detected objectively using the Atmospheric Infrared Sounder under a relatively low spatial resolution and cloud-mask information from the Moderate Resolution Imaging Spectroradiometer under a high horizontal resolution; this detection was conducted using space matching.Newton's nonlinear physical iterative solution technique is applied to the radiative transfer equation (RTE) to retrieve temperature profiles, relative humidity profiles, and surface variables simultaneously. This technique is carried out by using the results of an eigenvector regression retrieval as the background profile and using corresponding iterative forms for the weighting functions of temperature and water-vapor mixing ratio. The iterative forms are obtained by applying the variational principle to the RTE. We also compared the retrievals obtained with different types of observations. The results show that the retrieved atmospheric sounding profile has great superiority over other observations by accuracy and resolution. Retrieved profiles can be used to improve the initial conditions of numerical models and used in areas where conventional observations are sparse, such as plateaus, deserts, and seas.

  10. Glue Guns: Aiming for Safety (United States)

    Roy, Ken


    While glue guns are very useful, there are safety issues. Regardless of the temperature setting, glue guns can burn skin. The teacher should demonstrate and supervise the use of glue guns and have a plan should a student get burned. There should be an initial first aid protocol in place, followed by a visit to the school nurse. An accident report…

  11. Measured anisotropic air flow resistivity and sound attenuation of glass wool

    DEFF Research Database (Denmark)

    Tarnow, Viggo


    Department of Mechanical Engineering, Technical University of Denmark, Bygning 358, DK 2800 Lyngby, Denmark The air flow resistivity of glass wool has been measured in different directions. The glass wool was delivered from the manufacturer as slabs measuring 100×600×900 mm3, where the surface 600......×900 mm2 was parallel with the conveyor belt used in the manufacturing. Directions in the glass wool are described by a coordinate system with the X axis perpendicular to the conveyor belt, the Z axis in the direction the conveyor belt moves, and the Y axis perpendicular to the two other axes...

  12. Associations between immune function and air pollution among postmenopausal women living in the Puget Sound airshed (United States)

    Williams, Lori A.

    Air pollution is associated with adverse health outcomes, and changes in the immune system may be intermediate steps between exposure and a clinically relevant adverse health outcome. We analyzed the associations between three different types of measures of air pollution exposure and five biomarkers of immune function among 115 overweight and obese postmenopausal women whose immunity was assessed as part of a year-long moderate exercise intervention trial. For air pollution metrics, we assessed: (1) residential proximity to major roads (freeways, major arterials and truck routes), (2) fine particulate matter(PM2.5) at the nearest monitor to the residence averaged over three time windows (3-days, 30-days and 60-days), and (3) nitrogen dioxide (NO2) modeled based on land use characteristics. Our immune biomarkers included three measures of inflammation---C-reactive protein, serum amyloid A and interleukin-6---and two measures of cellular immunity---natural killer cell cytotoxicity and T lymphocyte proliferation. We hypothesized that living near a major road, increased exposure to PM2.5 and increased exposure to NO2 would each be independently associated with increased inflammation and decreased immune function. We observed a 21% lower average natural killer cell cytotoxicity among women living within 150 meters of a major arterial road compared to other women. For PM2.5 , we observed changes in 3 of 4 indicators of lymphocyte proliferation stimulated by anti-CD3---an antibody to the T cell receptor associated with increases in 3-day averaged PM2.5. For 30-day averaged PM 2.5 and 60-day averaged PM2.5 we did not observe any statistically significant associations. We observed an increase in lymphocyte proliferation index stimulated by the plant protein phytohemagglutinin (PHA) at 1 of 2 PHA concentrations in association with modeled NO2. For the three inflammatory markers, we observed no notable associations with any of our measures of air pollution. If confirmed, our

  13. Control of Toxic Chemicals in Puget Sound, Phase 3: Study of Atmospheric Deposition of Air Toxics to the Surface of Puget Sound

    Energy Technology Data Exchange (ETDEWEB)

    Brandenberger, Jill M.; Louchouarn, Patrick; Kuo, Li-Jung; Crecelius, Eric A.; Cullinan, Valerie I.; Gill, Gary A.; Garland, Charity R.; Williamson, J. B.; Dhammapala, R.


    The results of the Phase 1 Toxics Loading study suggested that runoff from the land surface and atmospheric deposition directly to marine waters have resulted in considerable loads of contaminants to Puget Sound (Hart Crowser et al. 2007). The limited data available for atmospheric deposition fluxes throughout Puget Sound was recognized as a significant data gap. Therefore, this study provided more recent or first reported atmospheric deposition fluxes of PAHs, PBDEs, and select trace elements for Puget Sound. Samples representing bulk atmospheric deposition were collected during 2008 and 2009 at seven stations around Puget Sound spanning from Padilla Bay south to Nisqually River including Hood Canal and the Straits of Juan de Fuca. Revised annual loading estimates for atmospheric deposition to the waters of Puget Sound were calculated for each of the toxics and demonstrated an overall decrease in the atmospheric loading estimates except for polybrominated diphenyl ethers (PBDEs) and total mercury (THg). The median atmospheric deposition flux of total PBDE (7.0 ng/m2/d) was higher than that of the Hart Crowser (2007) Phase 1 estimate (2.0 ng/m2/d). The THg was not significantly different from the original estimates. The median atmospheric deposition flux for pyrogenic PAHs (34.2 ng/m2/d; without TCB) shows a relatively narrow range across all stations (interquartile range: 21.2- 61.1 ng/m2/d) and shows no influence of season. The highest median fluxes for all parameters were measured at the industrial location in Tacoma and the lowest were recorded at the rural sites in Hood Canal and Sequim Bay. Finally, a semi-quantitative apportionment study permitted a first-order characterization of source inputs to the atmosphere of the Puget Sound. Both biomarker ratios and a principal component analysis confirmed regional data from the Puget Sound and Straits of Georgia region and pointed to the predominance of biomass and fossil fuel (mostly liquid petroleum products such

  14. Serbian society and gun culture

    Directory of Open Access Journals (Sweden)

    Cvetković Vladimir


    Full Text Available This paper questions whether one characteristic of Serbian society is a gun culture. The first part of the paper deals with some theoretical concerns and closer explanation of what is understood by the term gun culture. Few different approaches to the issue are analyzed. The concept used has three main components of the gun culture: system of positive beliefs; social symbols embodied by the gun; agent "bearers" of gun culture. The second part of the paper presents results from Small Arms and Light Weapons survey conducted in 2004 in Serbia. The results were analyzed within the theoretical framework proposed in the first part of the paper.

  15. The Rail Gun. (United States)

    Stewart, Gay B.


    Presents a rail gun demonstration that addresses a broad group of educational goals in introductory electricity and magnetism. Uses a battery-powered circuit consisting of a movable conductor placed across two conducting rails in a magnetic field to review mechanics, foster approximate reasoning and lateral class discussion, and demonstrate the…

  16. Radar gun hazards

    Energy Technology Data Exchange (ETDEWEB)


    Radar guns - hand-held units used by the law to nail speeders - have been in use since the early '60s. Now they've been accused of causing cancer. Police officers in several states have so far filed eight suits against the manufacturer, claiming that they have contracted rare forms of cancer, such as of the eyelid and the testicle, from frequent proximity to the devices. Spurred by concerns expressed by police groups, researchers at the Rochester Institute of Technology are conducting what they believe to be the first research of its kind in the nation. Last month psychologist John Violanti, an expert in policy psychology and health, sent out a one-page survey to 6,000 active and retired police officers in New York State, asking them about their health and their use of radar guns. Violanti says melanoma, leukemia, and lymph node cancer may be linked to these as well as other electromagnetic devices. The Food and Drug Administration earlier this year issued a warning about radar guns, telling users not to operate them closer than 6 inches from the body. But this may not be a sufficient safeguard since the instruments can give off crisscrossing wave emissions within a police vehicle. The survey will be used to help determine if it would be safer to mount the guns, which are currently either hand-held or mounted on dashboards, outside troopers' cars.

  17. E-Gun Technology (United States)


    AD E-GUN TECHNOLOGY N FINAL TECHNICAL REPORT J. E. Eninger , H. W. Friedman and K. E. Williams AVCO EVERETT RESEARCH LABORATORY, INC. Contract No...Report J.E. Eninger , H.W. Friedman and K.E. Williams AVCO EVERETT RESEARCH LABORATORY, INC. A Subsidiary of Avco Corporation 2385 Revere Beach Parkway

  18. Giving Up the Gun. (United States)

    LaRue, Robert D.


    Provides a model lesson from the book "Science/Technology/Society: Model Lessons for Secondary Social Studies Classes." Outlines Japan's campaign in the seventeenth and eighteenth centuries to rid itself of guns and return to swords. Provides background information and student handouts. (RW)

  19. Injuries due to firearms and air guns among U.S. military members not participating in overseas combat operations, 2002-2011. (United States)


    During 2002-2011, active component U.S. service members sustained 4,657 firearm-related injuries in circumstances other than deployment to the wars in Iraq/Afghanistan; 35 percent of the injuries were fatal. The highest firearm-related injury rates reflected service members in law enforcement/security and combat occupations. Of fatal injuries, 28 percent and 24 percent were suicides and homicides, respectively; among service members 30 and older, 84 percent of noncombat firearm-related deaths were suicides and 14 percent were homicides. In circumstances other than war, rates of both fatal and nonfatal firearm- related injuries are much lower among military members than civilian males aged 18-44. During the period, rates of nonfatal firearm-related injuries among non-deployed military members increased sharply, peaking in 2008. The trend reflects that among U.S. civilian males aged 18-44. However, firearm-related fatality rates were stable among civilians but increased among military members. The increase in rates of firearm-related fatalities among non-deployed military members reflects the increase in rates of suicides by firearms. Rates of injuries due to BB, pellet or paintball guns also increased during the period.

  20. Sound and Sound Sources

    DEFF Research Database (Denmark)

    Larsen, Ole Næsbye; Wahlberg, Magnus


    . To produce directional sounds, even higher frequencies and shorter wavelengths are needed. In this context ‘short’ is measured relative to the size of the sound source. Some sound sources, such as dipoles and pistons, are inherently directional, whereas others, such as monopoles, are inherently...

  1. Gun Attitudes and Fear of Crime. (United States)

    Heath, Linda; Weeks, Kyle; Murphy, Marie Mackay


    Using three studies, examined the relationship between attitudes toward guns and fear of crime. Findings indicate a connection between fear of crime and attitudes toward guns: people higher in fear of crime favored gun control. Results also established a relationship between stereotypical beliefs about gun victims and support for gun control. (RJM)

  2. Friction in rail guns (United States)

    Kay, P. K.


    The influence of friction is included in the present equations describing the performance of an inductively driven rail gun. These equations, which have their basis in an empirical formulation, are applied to results from two different experiments. Only an approximate physical description of the problem is attempted, in view of the complexity of details in the interaction among forces of this magnitude over time periods of the order of milisecs.

  3. Effects of Exposure to the Sound from Seismic Airguns on Pallid Sturgeon and Paddlefish. (United States)

    Popper, Arthur N; Gross, Jackson A; Carlson, Thomas J; Skalski, John; Young, John V; Hawkins, Anthony D; Zeddies, David


    This study examined the effects of exposure to a single acoustic pulse from a seismic airgun array on caged endangered pallid sturgeon (Scaphirhynchus albus) and on paddlefish (Polyodon spathula) in Lake Sakakawea (North Dakota, USA). The experiment was designed to detect the onset of physiological responses including minor to mortal injuries. Experimental fish were held in cages as close as 1 to 3 m from the guns where peak negative sound pressure levels (Peak- SPL) reached 231 dB re 1 μPa (205 dB re 1 μPa2·s sound exposure level [SEL]). Additional cages were placed at greater distances in an attempt to develop a dose-response relationship. Treatment and control fish were then monitored for seven days, euthanized, and necropsied to determine injuries. Necropsy results indicated that the probability of delayed mortality associated with pulse pressure following the seven day monitoring period was the same for exposed and control fish of both species. Exposure to a single pulse from a small air gun array (10,160 cm3) was not lethal for pallid sturgeon and paddlefish. However, the risks from exposure to multiple sounds and to sound exposure levels that exceed those reported here remain to be examined.


    Directory of Open Access Journals (Sweden)

    W.M. Bisset


    Full Text Available Although a great many articles have been written on the subject of Cape Town's noon gun (the. official terminology is 'time-gun' most of the writers have not had access to the Lion Battery Fort Record Book and the existance of more than one Cape Town time-gun has only recently been recorded. By 1807 a noon gun was fired regularly from the Imhoff Battery on the seaward side of the Castle.1 On 4 August 1902 the noon gun was fired from Lion Battery on Signal Hill for the first time.2 The battery was built because of fears of war with Russia and had been armed with two 9- inch Rifled Muzzle Loading guns by 1891. Lion Battery was remodelled in 1911.

  5. Wisconsin SRF Electron Gun Commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Bisognano, Joseph J. [University of Wisconsin-Madison; Bissen, M. [University of Wisconsin-Madison; Bosch, R. [University of Wisconsin-Madison; Efremov, M. [University of Wisconsin-Madison; Eisert, D. [University of Wisconsin-Madison; Fisher, M. [University of Wisconsin-Madison; Green, M. [University of Wisconsin-Madison; Jacobs, K. [University of Wisconsin-Madison; Keil, R. [University of Wisconsin-Madison; Kleman, K. [University of Wisconsin-Madison; Rogers, G. [University of Wisconsin-Madison; Severson, M. [University of Wisconsin-Madison; Yavuz, D. D. [University of Wisconsin-Madison; Legg, Robert A. [JLAB; Bachimanchi, Ramakrishna [JLAB; Hovater, J. Curtis [JLAB; Plawski, Tomasz [JLAB; Powers, Thomas J. [JLAB


    The University of Wisconsin has completed fabrication and commissioning of a low frequency (199.6 MHz) superconducting electron gun based on a quarter wave resonator (QWR) cavity. Its concept was optimized to be the source for a CW free electron laser facility. The gun design includes active tuning and a high temperature superconducting solenoid. We will report on the status of the Wisconsin SRF electron gun program, including commissioning experience and first beam measurements.

  6. 气垫隔声结构水中隔声性能分析%Analysis of Underwater Performance of Sound Insulation Structure with Air Cushion

    Institute of Scientific and Technical Information of China (English)

    周涛; 陈志坚


      提出气垫隔声结构形式,与以橡胶阻尼材料为基体的隔声去耦瓦相比,气垫隔声结构具有孔隙率大的特点,能更好的隔声去耦。用解析方法分析无限、有限气垫隔声结构在水中的隔声性能,研究板厚与中间层特性声阻抗对隔声量的影响并分析无限结构与有限结构的差别。结果表明:在水中的隔声曲线中没有在空气中因“质量―弹簧―质量”共振造成的隔声低谷现象,且在低频时有限结构的隔声性能较好。行波管声学试验测试了气垫双层板结构的低频隔声性能,证实气垫隔声结构在水中的隔声效果和其在水中声学性能的正确性。%The sound insulation structure with air cushion was presented. Compared with the sound-isolating decoupling tiles made of rubber damping material, this structure has better sound-isolating and decoupling effect due to its large porosity. The underwater sound insulation performances of infinite and finite double-layer panel structures with air cushions were studied respectively with analytical method. The influences of panel thickness and characteristic impedance of the middle layer on the sound-isolating performance were analyzed. The results show that the phenomenon of sound-isolation valley due to the mass-spring-mass resonance disappears and the finite-sized structure has a better sound-isolating performance in low frequency range. Finally, traveling wave tube test was carried out to investigate the finite-sized structure. The test results verified the correctness of this method for analyzing the underwater sound insulation performance of the structures.

  7. Methods for coating conduit interior surfaces utilizing a thermal spray gun with extension arm (United States)

    Moore, Karen A.; Zatorski, Raymond A.


    Systems and methods for applying a coating to an interior surface of a conduit. In one embodiment, a spray gun configured to apply a coating is attached to an extension arm which may be inserted into the bore of a pipe. The spray gun may be a thermal spray gun adapted to apply a powder coating. An evacuation system may be used to provide a volume area of reduced air pressure for drawing overspray out of the pipe interior during coating. The extension arm as well as the spray gun may be cooled to maintain a consistent temperature in the system, allowing for more consistent coating.

  8. Influence of Wall Surface and Air Modelling in Finite-Element Analysis of Sound Transmission Between Rooms in Lightweight Buildings

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard; Kirkegaard, Poul Henning; Dickow, Kristoffer Ahrens


    Noise is a nuisance in the built environment, and to avoid undesirable transmission of sound and vibration within a building, its vibro-acoustic performance must be addressed in the design phase. For heavy structures, a reliable assessment of the sound pressure levels can be made by statistical...

  9. Weight of RCL Guns in Comparison to Conventional Guns

    Directory of Open Access Journals (Sweden)

    J. P. Sirpal


    Full Text Available A study has been made of the weight of ordnance and equipment for a given performance. The comparative weights of the RCL and the orthodox equipments have been studied and it has been found that for the same muzzle energy the weight of RCL gun is 1/4th that of orthodox gun.

  10. Gun Concerns Personal for Duncan (United States)

    McNeil, Michele


    As U.S. Secretary of Education Arne Duncan works with other Obama administration officials on policy responses to the shootings at a Connecticut elementary school, he brings a personal and professional history that has acquainted him with the impact of gun violence. As schools chief in Chicago from 2001 to 2008, he was affected by the gun deaths…

  11. 空调机房的隔音降噪措施研究%The sound insulation and noise elimination measures research on air conditioning room

    Institute of Scientific and Technical Information of China (English)



    Taking the Shanxi Library engineering as an example,analyzed the noise sources of air conditioning and ventilation system,from the layout,noise elimination,sound absorption and insulation three angles researched the noise elimination measures of air conditioning rooms,de-scribed in detail,so as to economy,effectively reduce the noise generated by the air conditioning system of large scale public buildings.%以山西省图书馆工程为例,分析了空调通风系统的噪声源,从布局、消声降噪、吸音隔音三个角度研究了空调机房降噪措施,并作了详细阐述,以经济、有效地降低大型公共建筑空调系统所产生的噪声。

  12. Preventing gun injuries in children. (United States)

    Crossen, Eric J; Lewis, Brenna; Hoffman, Benjamin D


    Firearms are involved in the injury and death of a large number of children each year from both intentional and unintentional causes. Gun ownership in homes with children is common, and pediatricians should incorporate evidence-based means to discuss firearms and protect children from gun-related injuries and violence. Safe storage of guns, including unloaded guns locked and stored separately from ammunition, can decrease risks to children, and effective tools are available that pediatricians can use in clinical settings to help decrease children's access to firearms. Furthermore, several community-based interventions led by pediatricians have effectively reduced firearm-related injury risks to children. Educational programs that focus on children's behavior around guns have not proven effective.

  13. LCLS Gun Solenoid Design Considerations

    Energy Technology Data Exchange (ETDEWEB)

    Schmerge, John


    The LCLS photocathode rf gun requires a solenoid immediately downstream for proper emittance compensation. Such a gun and solenoid have been operational at the SSRL Gun Test Facility (GTF) for over eight years. Based on magnetic measurements and operational experience with the GTF gun solenoid multiple modifications are suggested for the LCLS gun solenoid. The modifications include adding dipole and quadrupole correctors inside the solenoid, increasing the bore to accommodate the correctors, decreasing the mirror plate thickness to allow the solenoid to move closer to the cathode, cutouts in the mirror plate to allow greater optical clearance with grazing incidence cathode illumination, utilizing pancake coil mirror images to compensate the first and second integrals of the transverse fields and incorporating a bipolar power supply to allow for proper magnet standardization and quick polarity changes. This paper describes all these modifications plus the magnetic measurements and operational experience leading to the suggested modifications.

  14. Guns and sleep

    Directory of Open Access Journals (Sweden)

    Quan SF


    Full Text Available No abstract available. Article truncated at 150 words. Gun deaths are a problem in America. Irrespective of one’s position on gun control, the statistics do not lie. According to the Centers for Disease Control and Prevention (CDC, there were 11,208 deaths caused by firearms in 2013 (1. The recent high profile cases in Cincinnati, OH, Lafayette, LA and Memphis, TN further highlight the issue. Obviously, each case of death by a firearm had its own set of underlying factors that contributed to the final fatal outcome, but one wonders whether sleep deprivation can be implicated in some of them. Sleep duration in adults over the past approximately 30 years has been declining in the United States (2. A variety of reasons can be cited as underlying causes such as greater use of artificial lighting, an expanding 24 hour non-stop society, promotion of a work ethic that values “burning the midnight oil”, and use of electronic devices before bedtime ...

  15. Gun shows and gun violence: fatally flawed study yields misleading results. (United States)

    Wintemute, Garen J; Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A


    A widely publicized but unpublished study of the relationship between gun shows and gun violence is being cited in debates about the regulation of gun shows and gun commerce. We believe the study is fatally flawed. A working paper entitled "The Effect of Gun Shows on Gun-Related Deaths: Evidence from California and Texas" outlined this study, which found no association between gun shows and gun-related deaths. We believe the study reflects a limited understanding of gun shows and gun markets and is not statistically powered to detect even an implausibly large effect of gun shows on gun violence. In addition, the research contains serious ascertainment and classification errors, produces results that are sensitive to minor specification changes in key variables and in some cases have no face validity, and is contradicted by 1 of its own authors' prior research. The study should not be used as evidence in formulating gun policy.

  16. The effects of pulse pressure from seismic water gun technology on Northern Pike (United States)

    Gross, Jackson A.; Irvine, Kathryn M.; Wilmoth, Siri K.; Wagner, Tristany L.; Shields, Patrick A; Fox, Jeffrey R.


    We examined the efficacy of sound pressure pulses generated from a water gun for controlling invasive Northern Pike Esox lucius. Pulse pressures from two sizes of water guns were evaluated for their effects on individual fish placed at a predetermined random distance. Fish mortality from a 5,620.8-cm3 water gun (peak pressure source level = 252 dB referenced to 1 μP at 1 m) was assessed every 24 h for 168 h, and damage (intact, hematoma, or rupture) to the gas bladder, kidney, and liver was recorded. The experiment was replicated with a 1,966.4-cm3 water gun (peak pressure source level = 244 dB referenced to 1 μP at 1 m), but fish were euthanized immediately. The peak sound pressure level (SPLpeak), peak-to-peak sound pressure level (SPLp-p), and frequency spectrums were recorded, and the cumulative sound exposure level (SELcum) was subsequently calculated. The SPLpeak, SPLp-p, and SELcum were correlated, and values varied significantly by treatment group for both guns. Mortality increased and organ damage was greater with decreasing distance to the water gun. Mortality (31%) by 168 h was only observed for Northern Pike exhibiting the highest degree of organ damage. Mortality at 72 h and 168 h postexposure was associated with increasing SELcum above 195 dB. The minimum SELcum calculated for gas bladder rupture was 199 dB recorded at 9 m from the 5,620.8-cm3 water gun and 194 dB recorded at 6 m from the 1,966.4-cm3water gun. Among Northern Pike that were exposed to the large water gun, 100% of fish exposed at 3 and 6 m had ruptured gas bladders, and 86% exposed at 9 m had ruptured gas bladders. Among fish that were exposed to pulse pressures from the smaller water gun, 78% exhibited gas bladder rupture. Results from these initial controlled experiments underscore the potential of water guns as a tool for controlling Northern Pike.

  17. Guns as a Symbol of American Individualism

    Institute of Scientific and Technical Information of China (English)



    Due to continuous gun violence, Americans' crazy love for guns has always been attacked home and abroad. Americans' passion for guns derives from individualism through the development of American history. They consider guns as a means to guarantee independence and freedom, and therefore as a symbol of American individualism.

  18. Calculating effective gun control policies

    CERN Document Server

    Wodarz, Dominik


    Following recent shootings in the USA, a debate has erupted, one side favoring stricter gun control, the other promoting protection through more weapons. We provide a scientific foundation to inform this debate, based on population dynamic models that quantify the dependence of firearm-related death rates of people on gun policies. We assume a shooter attacking a single individual or a crowd. Two strategies can minimize deaths in the model, depending on parameters: either a ban of private firearms possession, or a policy allowing the general population to carry guns. In particular, the outcome depends on the fraction of offenders that illegally possess a gun, on the degree of protection provided by gun ownership, and on the fraction of the population who take up their right to own a gun and carry it with them when attacked, parameters that can be estimated from statistical data. With the measured parameters, the model suggests that if the gun law is enforced at a level similar to that in the United Kingdom, g...

  19. Stratospheric ozone loss in the 1996/1997 Arctic winter: Evaluation based on multiple trajectory analysis for double-sounded air parcels by ILAS (United States)

    Terao, Yukio; Sasano, Yasuhiro; Nakajima, Hideaki; Tanaka, H. L.; Yasunari, Tetsuzo


    Quantitative chemical ozone loss rates and amounts in the Arctic polar vortex for the spring of 1997 are analyzed based on ozone profile data obtained by the Improved Limb Atmospheric Spectrometer (ILAS) using an extension of the Match technique. In this study, we calculated additional multiple trajectories and set very strict criteria to overcome the weakness of the satellite sensor data (lower vertical resolution and larger sampling air mass volume) and to identify more accurately a double-sounded air mass. On the average inside the inner edge of the vortex boundary (north of about 70°N equivalent latitude), the local ozone loss rate was 50-80 ppbv/day at the maximum during late February between the levels of 450 and 500 K potential temperatures. The integrated ozone loss during February to March reached 2.0 ± 0.1 ppmv at 475-529 K levels, and the column ozone loss between 400 and 600 K during the 2 months was 96 ± 0.3 DU. Using a relative potential vorticity (rPV) scale, the vortex was divided into some rPV belts, and it was shown that the magnitude of the ozone loss increased gradually toward the vortex center from the edge. The maximum ozone loss rate of 6.0 ± 0.6 ppbv/sunlit hour near the vortex center was higher than near the vortex edge by a factor of 2-3. When we expanded the area of interest to include all the data obtained inside the vortex edge (north of about 65°N equivalent latitude), the local ozone loss rate was about 50 ppbv/day at the maximum. This value is slightly larger than that estimated by the Match analysis using ozonesondes for the same winter by ˜10 ppbv/day. Temperature histories of double-sounded air parcels indicated that the extreme ozone loss in the innermost part of the vortex was observed when the air parcel experienced temperatures below TNAT during the two soundings and had experienced temperatures near Tice in the 10 days prior to the first sounding. These facts suggest that the high ozone loss rate deep inside the vortex

  20. Gun barrel erosion - Comparison of conventional and LOVA gun propellants

    NARCIS (Netherlands)

    Hordijk, A.C.; Leurs, O.


    The research department Energetic Materials within TNO Defence, Security and Safety is involved in the development and (safety and insensitive munitions) testing of conventional (nitro cellulose based) and thermoplastic elastomer (TPE) based gun propellants. Recently our testing capabilities have be

  1. A Sounding-based Severe Weather Tool to Support Daily Operations at Kennedy Space Center and Cape Canaveral Air Force Station (United States)

    Bauman, William H.; Roeder, William P.


    People and property at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) are at risk when severe weather occurs. Strong winds, hail and tornadoes can injure individuals and cause costly damage to structures if not properly protected. NASA's Launch Services Program and Ground Systems Development and Operations Program and other KSC programs use the daily and weekly severe weather forecasts issued by the 45th Weather Squadron (45 WS) to determine if they need to limit an activity such as working on gantries, or protect property such as a vehicle on a pad. The 45 WS requested the Applied Meteorology Unit (AMU) develop a warm season (May-September) severe weather tool for use in the Meteorological Interactive Data Display System (MIDDS) based on the late morning, 1500 UTC (1100 local time), CCAFS (XMR) sounding. The 45 WS frequently makes decisions to issue a severe weather watch and other severe weather warning support products to NASA and the 45th Space Wing in the late morning, after the 1500 UTC sounding. The results of this work indicate that certain stability indices based on the late morning XMR soundings can depict differences between days with reported severe weather and days with no reported severe weather. The AMU determined a frequency of reported severe weather for the stability indices and implemented an operational tool in MIDDS.

  2. Temporal association between federal gun laws and the diversion of guns to criminals in Milwaukee. (United States)

    Webster, Daniel W; Vernick, Jon S; Bulzacchelli, Maria T; Vittes, Katherine A


    The practices of licensed gun dealers can threaten the safety of urban residents by facilitating the diversion of guns to criminals. In 2003, changes to federal law shielded gun dealers from the release of gun trace data and provided other protections to gun dealers. The 14-month period during which the dealer did not sell junk guns was associated with a 68% reduction in the diversion of guns to criminals within a year of sale by the dealer and a 43% increase in guns diverted to criminals following sales by other dealers. The laws were associated with a 203% increase in the number of guns diverted to criminals within a year of sale by the gun store, which was the focus of this study. Policies which affect gun dealer accountability appeared to influence the diversion of guns to criminals.

  3. PEMETAAN POTENSI AIR-TANAH (AQUIFER BERDASARKAN INTERPRETASI DATA\tRESISTIVITAS WENNER SOUNDING (Studi kasus: Pengembangan kampus II Universitas Islam Negeri Maulana Malik Ibrahim Malang di Desa Tlekung Kecamatan Junrejo Kota Batu

    Directory of Open Access Journals (Sweden)

    Irjan Irjan


    Full Text Available Telah dilakukan penelitian pemetaan potensi air-tanah (aquifer di daerah pengembangan kampus II UIN Maliki Malang di desa Tlekung kecamatan Junrejo wilayah kota Batu Jawa Timur. Urgensi dari penelitian ini adalah mencari sumber air-tanah dan melakukan pemetaan potensi air-tanah di bawah permukaan ke arah vertikal pada lokasi yang diduga setelah terlebih dahulu dilakukan survei permukaan. Dalam melakukan pemetaan potensi dan sebaran air-tanah di daerah survei, penulis menggunakan metode geolistrik resistivitas. Metode ini biasanya digunakan untuk menyelidiki lapisan bawah permukaan dangkal berdasarkan tingkat resistivitas batuannya dengan air-tanah yang menempati rongga-rongga dalam lapisan geologi (tanah. Survei ini dapat memetakan potensi air-tanah baik secara vertikal maupun horizontal. Survei geolistrik vertikal (sounding dimaksudkan untuk menduga ketebalan lapisan yang mengandung air-tanah atau aquifer. Sementara itu, untuk menduga persebaran air-tanah di bawah permukaan telah dilakukan  pengukuran  dibeberapa titik sounding pada daerah survei. Akuisisi data  metode geolistrik ini menggunakan sebuah alat Resistivity meter OYO Mc 2119. Secara prinsip pengukuran data dilakukan dengan cara menembakkan arus melalui elektroda arus (I dan mengamati beda potensial (  V pada setiap posisi jarak antara elektoda a, 2a, 3a, dan seterusnya. Titik sounding (titik datum pada penelitian ini berjumlah 3 (tiga buah dan terletak pada satu lintasan yang memanjang dari arah utara ke selatan. Untuk mengetahui posisi datum point, seperti   posisi lintang, bujur serta ketinggian dari permukaan laut digunakan GPS (Global Positioning System. Hasil pengukuran data-data lapangan, dengan menggunakan metode resistivitas wenner sounding mampu mendeteksi kehadiran lapisan zona aquifer serta mampu menduga lithologi batuan berdasarkan klasifikasi resistivitas sepanjang dinding sumur ke arah vertikal. Keyword:  Air-tanah  (aquifer,  metode  geolistrik resistivitas

  4. The case for moderate gun control. (United States)

    DeGrazia, David


    In addressing the shape of appropriate gun policy, this essay assumes for the sake of discussion that there is a legal and moral right to private gun ownership. My thesis is that, against the background of this right, the most defensible policy approach in the United States would feature moderate gun control. The first section summarizes the American gun control status quo and characterizes what I call "moderate gun control." The next section states and rebuts six leading arguments against this general approach to gun policy. The section that follows presents a positive case for moderate gun control that emphasizes safety in the home and society as well as rights whose enforcement entails some limits or qualifications on the right to bear arms. A final section shows how the recommended gun regulations address legitimate purposes, rather than imposing arbitrary restrictions on gun rights, and offers concluding reflections.

  5. Size-Segregated Aerosol Composition and Mass Loading of Atmospheric Particles as Part of the Pacific Northwest 2001(PNW2001) Air Quality Study In Puget Sound (United States)

    Disselkamp, R. S.; Barrie, L. A.; Shutthanadan, S.; Cliff, S.; Cahill, T.


    In mid-August, 2001, an aircraft-based air-quality study was performed in the Puget Sound, WA, area entitled PNW2001 ( The objectives of this field campaign were the following: 1. reveal information about the 3-dimensional distribution of ozone, its gaseous precursors and fine particulate matter during weather conditions favoring air pollution; 2. derive information about the accuracy of urban and biogenic emissions inventories that are used to drive the air quality forecast models; and 3. examine the accuracy of modeled ozone concentration with that observed. In support of these efforts, we collected time-averaged ( { ~}10 minute averages), size-segregated, aerosol composition and mass-loading information using ex post facto analysis techniques of synchrotron x-ray fluorescence (s-XRF), proton induced x-ray emissions(PIXE), proton elastic scattering (PESA), and scanning transmission ion microscopy (STIM). This is the first time these analysis techniques have been used together on samples collected from aircraft using an optimized 3-stage rotating drum impactor. In our presentation, we will discuss the aerosol components in three aerosol size fractions as identified by statistical analysis of multielemental data (including total mass, H, Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Pb) and relate variations in these components to physical aerosol properties, other gaseous trace constituents and to air mass origin.

  6. PEMETAAN AIR TANAH MENGGUNAKAN METODE RESISTIVITAS WENNER SOUNDING (Studi Kasus Kampus II Universitas Islam Negeri Maulana Malik Ibrahim Malang

    Directory of Open Access Journals (Sweden)

    A.M. Miftahul Huda


    Full Text Available Human is khalifa in this earth, it was presented at Qoran (Al-Fathir: 39. Then the  earth is authority and responsibility of human to saving and managing. Include of that is  aquifer. Aquifer is the water that is available in the throat of geology which permeable. The mapping of aquifer potency is important because it used for developing the collage II Islamic State University Maulana Malik Ibrahim of Malang at Junrejo, Batu. Good water is predicted consume at high level in future. This investigation purposefull to know the place of the potentiality of aquifer in the location of investigation verticality. The method used in this research is Resistivity Geoelectric is an used to investigate the current surface based on stone resistivity. In this  case,  is  used  wenner  sounding  configuration.  potentiality  of  aquifer  in  the location of investigation verticality. At the every measuring using resistivity meter OYO Mc 2119. The result of the survey show if variety of depth and thick layers of aquifer; whit the best potentiality of aquifer at sounding point 2 C C (7° 55' 11,9" LS dan 112° 32' 36,1" BT in second line. Potency source of aquifer at hight more than 93,8 meter from surface. Then in first line, potency of aquifer is predicted bad. Cross-correlaton of sounding points showed that formation of geology is sands, sand- limestone, clay, and breccia. Kata Kunci: Qoran, Aquifer, Resistivity method of wenner sounding, Potency of Aquifer.

  7. Large Bore Powder Gun Qualification (U)

    Energy Technology Data Exchange (ETDEWEB)

    Rabern, Donald A. [Los Alamos National Laboratory; Valdiviez, Robert [Los Alamos National Laboratory


    A Large Bore Powder Gun (LBPG) is being designed to enable experimentalists to characterize material behavior outside the capabilities of the NNSS JASPER and LANL TA-55 PF-4 guns. The combination of these three guns will create a capability to conduct impact experiments over a wide range of pressures and shock profiles. The Large Bore Powder Gun will be fielded at the Nevada National Security Site (NNSS) U1a Complex. The Complex is nearly 1000 ft below ground with dedicated drifts for testing, instrumentation, and post-shot entombment. To ensure the reliability, safety, and performance of the LBPG, a qualification plan has been established and documented here. Requirements for the LBPG have been established and documented in WE-14-TR-0065 U A, Large Bore Powder Gun Customer Requirements. The document includes the requirements for the physics experiments, the gun and confinement systems, and operations at NNSS. A detailed description of the requirements is established in that document and is referred to and quoted throughout this document. Two Gun and Confinement Systems will be fielded. The Prototype Gun will be used primarily to characterize the gun and confinement performance and be the primary platform for qualification actions. This gun will also be used to investigate and qualify target and diagnostic modifications through the life of the program (U1a.104 Drift). An identical gun, the Physics Gun, will be fielded for confirmatory and Pu experiments (U1a.102D Drift). Both guns will be qualified for operation. The Gun and Confinement System design will be qualified through analysis, inspection, and testing using the Prototype Gun for the majority of process. The Physics Gun will be qualified through inspection and a limited number of qualification tests to ensure performance and behavior equivalent to the Prototype gun. Figure 1.1 shows the partial configuration of U1a and the locations of the Prototype and Physics Gun/Confinement Systems.

  8. Galois Got his Gun

    CERN Document Server

    Brechenmacher, Frederic


    This paper appeals to the figure of \\'Evariste Galois for investigating the gates between mathematics and their "publics." The figure of Galois draws some lines of/within mathematics for/from the outside of mathematics and these lines in turn sketch the silhouette of Galois as a historical figure. The present paper especially investigates the collective categories that have been used in various types of public discourses on Galois's work (e.g. equations, groups, algebra, analysis, France, Germany etc.). In a way, this paper aims at shedding light on the boundaries some individuals drew by getting Galois his gun. It is our aim to highlight the roles of authority some individuals (such as as Picard) took on in regard with the public figure of Galois as well as the roles such authorities assigned to other individuals (such as the mediating role assigned to Jordan as a mediator between Galois's "ideas" and the public). The boundary-works involved by most public references to Galois have underlying them a long-ter...

  9. Revisiting Pneumatic Nail Gun Trigger Recommendations. (United States)

    Albers, James; Lowe, Brian; Lipscomb, Hester; Hudock, Stephen; Dement, John; Evanoff, Bradley; Fullen, Mark; Gillen, Matt; Kaskutas, Vicki; Nolan, James; Patterson, Dennis; Platner, James; Pompeii, Lisa; Schoenfisch, Ashley


    Use of a pneumatic nail gun with a sequential actuation trigger (SAT) significantly diminishes the risk for acute traumatic injury compared to use of a contact actuation trigger (CAT) nail gun. A theoretically-based increased risk of work-related musculoskeletal disorders from use of a SAT nail gun, relative to CAT, appears unlikely and remains unproven. Based on current knowledge, the use of CAT nail guns cannot be justified as a safe alternative to SAT nail guns. This letter provides a perspective of ergonomists and occupational safety researchers recommending the use of the sequential actuation trigger for all nail gun tasks in the construction industry.

  10. Asian carp behavior in response to static water gun firing (United States)

    Layhee, Megan J.; Gross, Jackson A.; Parsley, Michael J.; Romine, Jason G.; Glover, David C.; Suski, Cory D.; Wagner, Tristany L.; Sepulveda, Adam J.; Gresswell, Robert E.


    The potential for invasion of Asian carp into the Great Lakes has ecological and socio-economic implications. If they become established, Asian carp are predicted to alter lake ecosystems and impact commercial and recreational fisheries. The Chicago Sanitary and Shipping Canal is an important biological conduit between the Mississippi River Basin, where invasive Asian carp are abundant, and the Great Lakes. Millions of dollars have been spent to erect an electric barrier defense in the canal to prevent movement of Asian carp into the Great Lakes, but the need for additional fish deterrent technologies to supplement the existing barrier is warranted. Scientists with the U.S. Geological Survey Northern Rocky Mountain Science Center are examining seismic water gun technology, formerly used in oceanic oil exploration, as a fish deterrent. The goal of the current study is to employ telemetry and sonar monitoring equipment to assess the behavioral response of Asian carp to seismic water guns and the sound energy it generates.

  11. The Internal Ballistics of an Air Gun (United States)

    Denny, Mark


    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…

  12. Foley Sounds vs Real Sounds

    DEFF Research Database (Denmark)

    Trento, Stefano; Götzen, Amalia De


    This paper is an initial attempt to study the world of sound effects for motion pictures, also known as Foley sounds. Throughout several audio and audio-video tests we have compared both Foley and real sounds originated by an identical action. The main purpose was to evaluate if sound effects...

  13. ATA injector-gun calculations

    Energy Technology Data Exchange (ETDEWEB)

    Paul, A.C.


    ATA is a pulsed, 50 ns 10 KA, 50 MeV linear induction electron accelerator at LLNL. The ETA could be used as an injector for ATA. However the possibility of building a new injector gun for ATA, raised the question as to what changes from the ETA gun in electrode dimensions or potentials, if any, should be considered. In this report the EBQ code results for the four electrode configurations are reviewed and an attempt is made to determine the geometrical scaling laws appropriate to these ETA type gun geometries. Comparison of these scaling laws will be made to ETA operation. The characteristic operating curves for these geometries will also be presented and the effect of washer position determined. It will be shown that emittance growth will impose a limitation on beam current for a given anode potential before the virtual cathode limit is reached.


    Directory of Open Access Journals (Sweden)

    I.A. Gorlach


    Full Text Available Many surface preparation and treatment processes utilise compressed air to propel particles against surfaces in order to clean and treat them. The effectiveness of the processes depends on the velocity of the particles, which in turn depends on the pressure of the compressed air. This paper describes a thermal gun built on the principles of High Velocity Air Fuel (HVAF and High Velocity Oxy Fuel (HVOF processes. The designed apparatus can be used for abrasive blasting, coating of surfaces, cutting of rocks, removing rubber from mining equipment, cleaning of contaminations etc.

  15. Hydrogen Embrittlement of Gun Steel (United States)


    8217s HY80 and HY130 steels were checked for the critical hydrogen concentrations which were determined to be 6 ppm for HY8O steel 8 and 3 ppm for HY130...JOTC FILE COPY AD-A188 972 AD 1 TECHNICAL REPORT ARCCB-TR-87030 HYDROGEN EMBRITTLEMENT OF GUN STEEL F’ GERALD L. SPFNCER DTIC DEC 1 5 1987 NOVEMBER...PtEtIOC COVERED HYDROGEN EMBRITTLEHENT OF GUN STEEL Final OG EOTNME 6. PERFORMINGORO EOTNME 7. A*JTNOR(s) S. CONTRACT OR GRANT NUMBER(&) Gerald L

  16. Liquid Propellants for Advanced Gun Ammunitions

    Directory of Open Access Journals (Sweden)

    K. P. Rao


    Full Text Available With constant improvements, the conventional solid propellants for guns have almost reached their limit in performance. Liquid gun propellants are promising new comers capable of surpassing these performance limits and have numerous advantages over solid propellants. A method has been worked out to predict the internal ballistics of a liquid propellant gun and illustrated in a typical application.

  17. Advances in light-gas gun technology (United States)

    Cowan, P. L.; Murphy, J. R.


    Constant-area accelerator used with light-gas guns increases the velocity of accelerating projectiles. A disposable accelerator on the muzzle of the gun uses the energy and momentum of a primary projectile, launched by the gun, to achieve high velocities of a light secondary projectile accelerated from rest in the accelerator.

  18. The Smoking Gun. (United States)

    Horrigan, Alice


    Examines the complex public debate over the risks of passive smoking that includes the issues of individual choice, personal space, community, social norms, and morality. Discusses the composition of ETS (gases and particulates that disperse into the air when a smoker smokes) and the efforts of tobacco lobbies. (LZ)

  19. Imagining Sound

    DEFF Research Database (Denmark)

    Grimshaw, Mark; Garner, Tom Alexander


    We make the case in this essay that sound that is imagined is both a perception and as much a sound as that perceived through external stimulation. To argue this, we look at the evidence from auditory science, neuroscience, and philosophy, briefly present some new conceptual thinking on sound...... that accounts for this view, and then use this to look at what the future might hold in the context of imagining sound and developing technology....

  20. Photoacoustic Sounds from Meteors (United States)

    Spalding, Richard; Tencer, John; Sweatt, William; Conley, Benjamin; Hogan, Roy; Boslough, Mark; Gonzales, GiGi; Spurný, Pavel


    Concurrent sound associated with very bright meteors manifests as popping, hissing, and faint rustling sounds occurring simultaneously with the arrival of light from meteors. Numerous instances have been documented with −11 to −13 brightness. These sounds cannot be attributed to direct acoustic propagation from the upper atmosphere for which travel time would be several minutes. Concurrent sounds must be associated with some form of electromagnetic energy generated by the meteor, propagated to the vicinity of the observer, and transduced into acoustic waves. Previously, energy propagated from meteors was assumed to be RF emissions. This has not been well validated experimentally. Herein we describe experimental results and numerical models in support of photoacoustic coupling as the mechanism. Recent photometric measurements of fireballs reveal strong millisecond flares and significant brightness oscillations at frequencies ≥40 Hz. Strongly modulated light at these frequencies with sufficient intensity can create concurrent sounds through radiative heating of common dielectric materials like hair, clothing, and leaves. This heating produces small pressure oscillations in the air contacting the absorbers. Calculations show that −12 brightness meteors can generate audible sound at ~25 dB SPL. The photoacoustic hypothesis provides an alternative explanation for this longstanding mystery about generation of concurrent sounds by fireballs. PMID:28145486

  1. A gasdynamic gun driven by gaseous detonation (United States)

    Li, Jinping; Chen, Hong; Zhang, Shizhong; Zhang, Xiaoyuan; Yu, Hongru


    A gasdynamic gun driven by gaseous detonation was developed to address the disadvantages of the insufficient driving capability of high-pressure gas and the constraints of gunpowder. The performance of this gasdynamic gun was investigated through experiments and numerical simulations. Much more powerful launching capability was achieved by this gun relative to a conventional high-pressure gas gun, owing to the use of the chemical energy of the driver gas. To achieve the same launching condition, the initial pressure required for this gun was an order of magnitude lower than that for a gun driven by high-pressure H2. Because of the presence of the detonation, however, a more complex internal ballistic process of this gun was observed. Acceleration of projectiles for this gun was accompanied by a series of impulse loads, in contrast with the smooth acceleration for a conventional one, which indicates that this gun should be used conditionally. The practical feasibility of this gun was verified by experiments. The experiments demonstrated the convenience of taking advantage of the techniques developed for detonation-driven shock tubes and tunnels.

  2. A Web Service Tool (SOAR) for the Dynamic Generation of L1 Grids of Coincident AIRS, AMSU and MODIS Satellite Sounding Radiance Data for Climate Studies (United States)

    Halem, M.; Yesha, Y.; Tilmes, C.; Chapman, D.; Goldberg, M.; Zhou, L.


    Three decades of Earth remote sensing from NASA, NOAA and DOD operational and research satellites carrying successive generations of improved atmospheric sounder instruments have resulted in petabytes of radiance data with varying spatial and spectral resolutions being stored at different data archives in various data formats by the respective agencies. This evolution of sounders and the diversities of these archived data sets have led to data processing obstacles limiting the science community from readily accessing and analyzing such long-term climate data records. We address this problem by the development of a web based Service Oriented Atmospheric Radiance (SOAR) system built on the SOA paradigm that makes it practical for the science community to dynamically access, manipulate and generate long term records of L1 pre-gridded sounding radiances of coincident multi-sensor data for regions specified according to user chosen criteria. SOAR employs a modification of the standard Client Server interactions that allows users to represent themselves directly to the Process Server through their own web browsers. The browser uses AJAX to request Javascript libraries and DHTML interfaces that define the possible client interactions and communicates the SOAP messages to the Process server allowing for dynamic web dialogs with the user to take place on the fly. The Process Server is also connected to an underlying high performance compute cluster and storage system which provides much of the data processing capabilities required to service the client requests. The compute cluster employs optical communications to NOAA and NASA for accessing the data and under the governance of the Process Server invokes algorithms for on-demand spatial, temporal, and spectral gridding. Scientists can choose from a variety of statistical averaging techniques for compositing satellite observed sounder radiances from the AIRS, AMSU or MODIS instruments to form spatial-temporal grids for

  3. Effects of a gun dealer's change in sales practices on the supply of guns to criminals. (United States)

    Webster, Daniel W; Vernick, Jon S; Bulzacchelli, Maria T


    Licensed gun dealers are a major conduit for gun trafficking. Prior to May 1999, a single gun store sold more than half of the guns recovered from criminals in Milwaukee, WI, shortly following retail sale. On May 10, 1999, the store stopped selling small, inexpensive handguns popular with criminals, often called "Saturday night specials." The purpose of this study was to estimate the effect of this gun store's changed sales practices on criminals' acquisition of new guns. We used an interrupted time-series design with comparisons to test for changes in the number of guns that police recovered from criminals within a year of retail sale following the gun dealer's new sales policy. The dealer's changed sales policy was associated with a 96% decrease in recently sold, small, inexpensive handguns use in crime in Milwaukee, a 73% decrease in crime guns recently sold by this dealer, and a 44% decrease in the flow of all new, trafficked guns to criminals in Milwaukee. The findings demonstrate the substantial impact that a single gun store's sales practices can have on the supply of new guns to criminals. Proposed anti-gun-trafficking efforts in other cities could benefit from targeting problem retail outlets.

  4. Ballistics of space launch by a rail gun (United States)

    Panin, Alexander


    The idea of using a big gun to launch objects to space has been around for years -- even Isaac Newton considered the concept. However the technology of accelerating a payload with a gun only recently began approaching orbital velocity (8 km/sec). NASA is currently experimenting with a rail gun which utilizes a magnetic field powered by electricity to accelerate a projectile along a set of rails, similar to train rails. Velocities up to 3 km/sec have been reported for small projectiles, and it seems that orbital velocities can soon become a reality too. We model a launch of various projectiles from Earth surface into the elevation corresponding to the low Earth orbit (about 200-250 km above Earth's surface). The goal of this modeling is to study feasibility of such launch (and accelerations induced), and the ballistics of the flight via Earth's atmosphere (the trajectory, air drag induced, pressure and temperature generated by air drag, etc) and thus the requirements for a mass, size, strength, heat shield, and general design of a payload capsule.

  5. Analysis of Heat Transfer in Actively Cooled Compound Gun Barrel

    Institute of Scientific and Technical Information of China (English)

    WU Bin; XIA Wei


    when a gun fires, a large amount of heat is brought in the barrel. Erosion/wear and security problems(self ignition of the propellant) associated with this high thermal energy have to be solved owing to the use of higher combustion gas temperature for improved cannon performance and firing at the sustained high rates. Barrel cooling technologies are the effective measures for addressing this issue. In view of the importance of having knowledge of the heat flux, an approach to calculate heat flux based on measurements was presented and validated. The calculated heat flux is used as the inner boundary condition for modeling heat transfer in a 155 mm mid-wall cooled compound gun barrel. Theoretical analysis and simulated results show that natural air cooling is dramatically slower than the forced liquid mid-wall cooling, accordingly wear life of actively cooled barrel is increased and barrel overheating is prevented.

  6. A two-Frequency RF Photocathode Gun

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, D.H. E-mail:; Ferrario, M.; Kimura, T.; Lewellen, J.; Limborg, C.; Raimondi, P.; Schmerge, J.F.; Serafini, L.; Smith, T.; Young, L


    In this paper we resurrect an idea originally proposed by Serafini (Nucl. Instr. and Meth. A 318 (1992) 301) in 1992 for an RF photocathode gun capable of operating simultaneously at the fundamental frequency and a higher frequency harmonic. Driving the gun at two frequencies with the proper field ratio and relative phase produces a beam with essentially no RF emittance and a linear longitudinal phase space distribution. Such a gun allows a completely new range of operating parameters for controlling space charge emittance growth. In addition, the linear longitudinal phase space distribution aids in bunch compression. This paper will compare results of simulations for the two-frequency gun with the standard RF gun and the unique properties of the two-frequency gun will be discussed.

  7. Sound Absorbers (United States)

    Fuchs, H. V.; Möser, M.

    Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

  8. 77 FR 37834 - Revocation of Certain Requirements Pertaining to Caps Intended for Use With Toy Guns and Toy Guns... (United States)


    ... Guns and Toy Guns Not Intended for Use With Caps AGENCY: Consumer Product Safety Commission. ACTION... use with toy guns and toy guns not intended for use with caps, which were included in the regulations... revoke our existing banning regulations pertaining to caps intended for use with toy guns and toy...

  9. 78 FR 66840 - Revocation of Certain Requirements Pertaining to Caps Intended for Use With Toy Guns and Toy Guns... (United States)


    ... Guns and Toy Guns Not Intended for Use With Caps AGENCY: Consumer Product Safety Commission. ACTION...-producing toys. Existing CPSC regulations pertaining to caps intended for use with toy guns refer to... intended for use with toy guns and toy guns not intended for use with caps. The final rule is...

  10. Racism, gun ownership and gun control: biased attitudes in US whites may influence policy decisions.

    Directory of Open Access Journals (Sweden)

    Kerry O'Brien

    Full Text Available OBJECTIVE: Racism is related to policies preferences and behaviors that adversely affect blacks and appear related to a fear of blacks (e.g., increased policing, death penalty. This study examined whether racism is also related to gun ownership and opposition to gun controls in US whites. METHOD: The most recent data from the American National Election Study, a large representative US sample, was used to test relationships between racism, gun ownership, and opposition to gun control in US whites. Explanatory variables known to be related to gun ownership and gun control opposition (i.e., age, gender, education, income, conservatism, anti-government sentiment, southern vs. other states, political identification were entered in logistic regression models, along with measures of racism, and the stereotype of blacks as violent. Outcome variables included; having a gun in the home, opposition to bans on handguns in the home, support for permits to carry concealed handguns. RESULTS: After accounting for all explanatory variables, logistic regressions found that for each 1 point increase in symbolic racism there was a 50% increase in the odds of having a gun at home. After also accounting for having a gun in the home, there was still a 28% increase in support for permits to carry concealed handguns, for each one point increase in symbolic racism. The relationship between symbolic racism and opposition to banning handguns in the home (OR1.27 CI 1.03,1.58 was reduced to non-significant after accounting for having a gun in the home (OR1.17 CI.94,1.46, which likely represents self-interest in retaining property (guns. CONCLUSIONS: Symbolic racism was related to having a gun in the home and opposition to gun control policies in US whites. The findings help explain US whites' paradoxical attitudes towards gun ownership and gun control. Such attitudes may adversely influence US gun control policy debates and decisions.

  11. Gun Control in Australia: A Criminological Perspective

    Directory of Open Access Journals (Sweden)

    Rick Sarre


    Full Text Available In recent months there has been an upsurge in contributions to the popular press from social commentators insisting that guns make our nation safer. This essay questions these assertions. The paper provides evidence to support a contrary affirmation: that is, in order to have a reduction in gun violence, there needs to be a reduction in the number of guns generally, and a continuation of the legal controls that currently shape firearms policy in Australia.

  12. Explosively Bonded Gun Tube Liner Development (United States)


    FOR OFFICIAL USE ONYLFGFF ARL-CR-0771 ● APR 2015 US Army Research Laboratory Explosively Bonded Gun Tube Liner Development...return it to the originator. ARL-CR-0771 ● APR 2015 US Army Research Laboratory Explosively Bonded Gun Tube Liner Development...COVERED (From - To) 12 January 2014–1 January 2015 4. TITLE AND SUBTITLE Explosively Bonded Gun Tube Liner Development 5a. CONTRACT NUMBER ORISE 1120

  13. Research on Hot Gunning Repairing in Laboratory

    Institute of Scientific and Technical Information of China (English)

    CAO Feng; LONG Shigang; MENG Qingmin; SUN Jialin; HONG Yanruo


    The lining of blast furnace may be damaged partly,so that gunning repair is needed. The bonding strength of boundary surface between the repairing layer and remained lining of blast furnace has been studied by thermal simulation.The factors influencing the bonding strength are the ingredient gunning repair temperature,remained lining condition and water content of gunning refractory.The bonding strength decreases with the increases of remained lining temperature.

  14. Small barium rail gun for plasma injection. (United States)

    Kiwamoto, Y


    A small rail gun with a barium electrode can be operated at higher than one shot per second to produce more than 2x10(16) barium ions with energy 10-20 eV. The operation of the gun takes advantage of the external magnetic field for cross-field plasma injection into a trap. Up to 7 kG of the magnetic field examined, the gun performance improves with the increased magnetic field strength.

  15. A Novel Satellite Mission Concept for Upper Air Water Vapour, Aerosol and Cloud Observations Using Integrated Path Differential Absorption LiDAR Limb Sounding

    Directory of Open Access Journals (Sweden)

    Claudia Weitnauer


    Full Text Available We propose a new satellite mission to deliver high quality measurements of upper air water vapour. The concept centres around a LiDAR in limb sounding by occultation geometry, designed to operate as a very long path system for differential absorption measurements. We present a preliminary performance analysis with a system sized to send 75 mJ pulses at 25 Hz at four wavelengths close to 935 nm, to up to 5 microsatellites in a counter-rotating orbit, carrying retroreflectors characterized by a reflected beam divergence of roughly twice the emitted laser beam divergence of 15 µrad. This provides water vapour profiles with a vertical sampling of 110 m; preliminary calculations suggest that the system could detect concentrations of less than 5 ppm. A secondary payload of a fairly conventional medium resolution multispectral radiometer allows wide-swath cloud and aerosol imaging. The total weight and power of the system are estimated at 3 tons and 2,700 W respectively. This novel concept presents significant challenges, including the performance of the lasers in space, the tracking between the main spacecraft and the retroreflectors, the refractive effects of turbulence, and the design of the telescopes to achieve a high signal-to-noise ratio for the high precision measurements. The mission concept was conceived at the Alpbach Summer School 2010.

  16. Community gun safety in Central Pennsylvania. (United States)

    Wargo, Christina; Erdman, Deborah A; Smith, Jill Gray; Widom, Kenneth; Reardon, Judith


    Firearm-related injuries are a public health issue in the United States. In rural Pennsylvania, it is a familiar way of life to have a gun or guns in the home. Safety behaviors along with gun storage in the home, specifically where there are young children (aged 6 years and younger), are a concern for this level I regional resource center in rural Pennsylvania. Head Start families were surveyed regarding gun safety habits before and after safety educational activities. A noteworthy number of families reported changing behaviors regarding better safety habits for storing and use of firearms in the home postsurvey.

  17. Conceptual Design for CLIC Gun Pulser

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Tao [SLAC National Accelerator Lab., Menlo Park, CA (United States)


    The Compact Linear Collider (CLIC) is a proposed future electron-positron collider, designed to perform collisions at energies from 0.5 to 5 TeV, with a nominal design optimized for 3 TeV (Dannheim, 2012). The Drive Beam Accelerator consists of a thermionic DC gun, bunching section and an accelerating section. The thermionic gun needs deliver a long (~143us) pulse of current into the buncher. A pulser is needed to drive grid of the gun to generate a stable current output. This report explores the requirements of the gun pulser and potential solutions to regulate grid current.

  18. Waves generated in the vicinity of an argon plasma gun in the ionosphere (United States)

    Cahill, L. J., Jr.; Arnoldy, R. L.; Lysak, R. L.; Peria, W.; Lynch, K. A.


    Wave and particle observations were made in the close vicinity of an argon plasma gun carned to over 600 km altitude on a sounding rocket. The gun was carned on a subpayload, separated from the main payload early in the flight. Twelve-second argon ion ejections were energized alternately with a peak energy of 100 or 200 eV. They produced waves, with multiple harmonics, in the range of ion cyclotron waves, 10 to 1000 Hz at rocket altitudes. Many of these waves could not be identified as corresponding to the cyclotron frequencies of any of the ions, argon or ambient, known to be present. In addition, the wave frequencies were observed to rise and fall and to change abruptly during a 12-s gun operation. The wave amplitudes, near a few hundred Hertz, were of the order of O. 1 V/m. Some of the waves may be ion-ion hybrid waves. Changes in ion populations were observed at the main payload and at the subpayload during gun operations. A gun-related, field-aligned, electron population also appeared.

  19. From gun politics to self-defense politics: a feminist critique of the great gun debate. (United States)

    Carlson, Jennifer D


    This article calls attention to a problematic binary produced by public debates surrounding gun rights and gun control-namely, that women must choose armed self-protection or no self-protection at all. I argue that both anti- and pro-gun discourses, drawing on and reproducing race and class privileges, use assumptions about women's physical inferiority to further their agendas. I highlight how both sides have used guns as the proxy for self-defense and conclude by calling for a shift in public discourse to focus on the broader question of the right to self-defense rather than the narrower question of gun rights.

  20. Electromagnetic Gun With Commutated Coils (United States)

    Elliott, David G.


    Proposed electromagnetic gun includes electromagnet coil, turns of which commutated in sequence along barrel. Electrical current fed to two armatures by brushes sliding on bus bars in barrel. Interaction between armature currents and magnetic field from coil produces force accelerating armature, which in turn, pushes on projectile. Commutation scheme chosen so magnetic field approximately coincides and moves with cylindrical region defined by armatures. Scheme has disadvantage of complexity, but in return, enables designer to increase driving magnetic field without increasing armature current. Attainable muzzle velocity increased substantially.

  1. Crafting a Gauss Gun Demonstration (United States)

    Blodgett, Matthew E.; Blodgett, E. D.


    A Gauss Gun launches a ferromagnetic projectile using a pulsed electromagnet. This demonstration provides a nice counterpoint to the popular Thompson's jumping ring demonstration, which launches a nonferromagnetic ring via repulsion of an induced current. The pulsed current must be short enough in duration so that the projectile is not retarded by lingering current in the launch solenoid, but also large enough to provide a suitably impressive velocity. This project involved an iterative design process, as we worked through balancing all the different design criteria. We recommend it as a very nice electronics design project which will produce a very portable and enjoyable demonstration. AAPT sponsor Earl Blodgett.

  2. The Xygra gun simulation tool.

    Energy Technology Data Exchange (ETDEWEB)

    Garasi, Christopher Joseph; Lamppa, Derek C.; Aubuchon, Matthew S.; Shirley, David Noyes; Robinson, Allen Conrad; Russo, Thomas V.


    Inductive electromagnetic launchers, or coilguns, use discrete solenoidal coils to accelerate a coaxial conductive armature. To date, Sandia has been using an internally developed code, SLINGSHOT, as a point-mass lumped circuit element simulation tool for modeling coilgun behavior for design and verification purposes. This code has shortcomings in terms of accurately modeling gun performance under stressful electromagnetic propulsion environments. To correct for these limitations, it was decided to attempt to closely couple two Sandia simulation codes, Xyce and ALEGRA, to develop a more rigorous simulation capability for demanding launch applications. This report summarizes the modifications made to each respective code and the path forward to completing interfacing between them.

  3. Concepts for a short wavelength rf gun (United States)

    Kuzikov, S. V.; Shchelkunov, S.; Vikharev, A. A.


    Three concepts of an rf gun to be operated at 0.1-10 mm wavelengths are considered. In all the concepts, the rf system exploits an accelerating traveling wave. In comparison with a classical decimeter standing-wave rf gun, we analyze the advantages of new concepts, available rf sources, and achievable beam parameters.

  4. On the theory of photocathode rf guns

    Institute of Scientific and Technical Information of China (English)

    GAO Jie


    In this paper we give a set of analytical formulae to describe the characteristics of photocathode rf guns at any rf frequencies, such as energy, energy spread, bunch length, out going current, and emittance functions of the laser injection phase, which are useful in the design and practical operation of rf guns.

  5. Gun Control: The Debate and Public Policy. (United States)

    Watkins, Christine


    Provides an overview and background information on the debate over gun control, as well as several teaching ideas. Handouts include a list of related topics drawn from various disciplines (economics, U.S. history), seven arguments for and against gun control, and a set of policy evaluation guidelines. (MJP)

  6. Guns and High Gas Output Devices Panel: Introduction (United States)

    Simmons, Ronald L.; Kaste, Pamela J.


    A new panel known as the Guns and High Gas Output Panel was organized in 1999 under the auspices of the JANNAF Propellant and Characterization SubCommittee (PDCS). This is an introduction to our first meeting, purpose of the panel, and the scope of activities to be covered. The primary purpose of the panel is very simple: to provide a single focal point for interfacing Government Laboratories (Department of Defense and Department of Energy) and commercial industry researchers to share R&D activities and findings (i.e. facilitate the exchange of information) specifically aimed at gun-launched propulsion and high-gas output devices (gas generators and air bag inflators). Specific areas of interest included in the Panel's scope (and the Technical Data Base) are the following: (1) new propellant formulations and chemistry, (2) new ingredients, (3) ballistic effects of the new formulations and ingredients, (4) new processing methods unique to gun propellants, (5) thermochemistry of new ingredients, (6) unique physical and mechanical properties, (7) burning rates of new propellants and small scale closed bomb testing, (8) plasma effects on the propellant, and (9) unique safety and insensitive munitions properties.

  7. Sequential injection gas guns for accelerating projectiles (United States)

    Lacy, Jeffrey M [Idaho Falls, ID; Chu, Henry S [Idaho Falls, ID; Novascone, Stephen R [Idaho Falls, ID


    Gas guns and methods for accelerating projectiles through such gas guns are described. More particularly, gas guns having a first injection port located proximate a breech end of a barrel and a second injection port located longitudinally between the first injection port and a muzzle end of the barrel are described. Additionally, modular gas guns that include a plurality of modules are described, wherein each module may include a barrel segment having one or more longitudinally spaced injection ports. Also, methods of accelerating a projectile through a gas gun, such as injecting a first pressurized gas into a barrel through a first injection port to accelerate the projectile and propel the projectile down the barrel past a second injection port and injecting a second pressurized gas into the barrel through the second injection port after passage of the projectile and to further accelerate the projectile are described.

  8. New Electron Gun System for BEPCII

    CERN Document Server

    Liu, Bo; Long Chi, Yun; Zhang, Chuang


    The new electron gun system for BEPCII has been put into operation since Nov. 2004. The article describes the design, experiment and operation of this new system. The design current of the gun is 10 A for the pulse lengths of 1 ns, 2.5 ns and 1 μs with repetition rate of 50 Hz. The gun is operated with a pulsed high voltage power supply which can provide up to 200 kV high voltage. Computer simulations have been carried out in the design stage, including simulation of the gun geometry and beam transportation. Some important relation curves are obtained during the experiment. Two-bunch operation is available and some elementary tests have been performed. New scheme of the gun control system based on EPICS is also presented. The real operation shows that the design and manufacturing is basically successful.

  9. Interpreting the empirical evidence on illegal gun market dynamics. (United States)

    Braga, Anthony A; Wintemute, Garen J; Pierce, Glenn L; Cook, Philip J; Ridgeway, Greg


    Thousands of Americans are killed by gunfire each year, and hundreds of thousands more are injured or threatened with guns in robberies and assaults. The burden of gun violence in urban areas is particularly high. Critics suggest that the results of firearm trace data and gun trafficking investigation studies cannot be used to understand the illegal supply of guns to criminals and, therefore, that regulatory and enforcement efforts designed to disrupt illegal firearms markets are futile in addressing criminal access to firearms. In this paper, we present new data to address three key arguments used by skeptics to undermine research on illegal gun market dynamics. We find that criminals rely upon a diverse set of illegal diversion pathways to acquire guns, gun traffickers usually divert small numbers of guns, newer guns are diverted through close-to-retail diversions from legal firearms commerce, and that a diverse set of gun trafficking indicators are needed to identify and shut down gun trafficking pathways.

  10. ERLP Gun Commissioning Beamline Design

    CERN Document Server

    Holder, D J; Hannon, F E


    The 4GLS project is a novel next-generation solution for a UK national light source. It is based on an energy recovery linac (ERL) operating at high average beam currents up to 100 mA and with compression schemes producing pulses in the 10 - 100 fs range. This challenging accelerator technology, new to Europe, necessitates a significant R&D programme and a major part of this is a low-energy prototype, the ERLP, which is currently under construction at Daresbury Laboratory, in the north-west of England. The first components of ERLP to be built will be the DC photocathode gun and low-energy beam transport and diagnostics. The gun will initially be operated with a diagnostic beamline in order to measure the properties of the high-brightness beams generated as fully as possible. This will allow comparison of its performance with the results of multi-particle tracking codes, prior to its integration into the ERLP machine. The diagnostic beamline will include diagnostics for measuring the transverse and longitu...

  11. Sound Intensity

    DEFF Research Database (Denmark)

    Crocker, M.J.; Jacobsen, Finn


    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  12. A Practical Example Aiding Understanding Momentum in 1D: The Water Gun Experiment (United States)

    MacLeod, Katarin


    The law of conservation of momentum is one that students often have difficulties understanding. This experiment allows students to use childhood toys to examine and calculate the muzzle velocity of their favourite water gun by using an air track, a spark timer or data logger and the law of conservation of momentum in a one-dimensional case, a…

  13. Gun Violence, Mental Illness, And Laws That Prohibit Gun Possession: Evidence From Two Florida Counties. (United States)

    Swanson, Jeffrey W; Easter, Michele M; Robertson, Allison G; Swartz, Marvin S; Alanis-Hirsch, Kelly; Moseley, Daniel; Dion, Charles; Petrila, John


    Gun violence kills about ninety people every day in the United States, a toll measured in wasted and ruined lives and with an annual economic price tag exceeding $200 billion. Some policy makers suggest that reforming mental health care systems and improving point-of-purchase background checks to keep guns from mentally disturbed people will address the problem. Epidemiological research shows that serious mental illness contributes little to the risk of interpersonal violence but is a strong factor in suicide, which accounts for most firearm fatalities. Meanwhile, the effectiveness of gun restrictions focused on mental illness remains poorly understood. This article examines gun-related suicide and violent crime in people with serious mental illnesses, and whether legal restrictions on firearm sales to people with a history of mental health adjudication are effective in preventing gun violence. Among the study population in two large Florida counties, we found that 62 percent of violent gun crime arrests and 28 percent of gun suicides involved individuals not legally permitted to have a gun at the time. Suggested policy reforms include enacting risk-based gun removal laws and prohibiting guns from people involuntarily detained in short-term psychiatric hospitalizations.

  14. Gun Safety Management with Patients at Risk for Suicide (United States)

    Simon, Robert I.


    Guns in the home are associated with a five-fold increase in suicide. All patients at risk for suicide must be asked if guns are available at home or easily accessible elsewhere, or if they have intent to buy or purchase a gun. Gun safety management requires a collaborative team approach including the clinician, patient, and designated person…

  15. Ready, Fire, Aim: The College Campus Gun Fight (United States)

    Birnbaum, Robert


    The question of whether guns should be permitted on college and university campuses in the United States reflects the tension between two competing perspectives. America has both a robust gun culture and an equally robust (if less well known) gun-control culture. The gun culture is as American as apple pie: There may be as many as 300 million…

  16. Alignment Fixtures For Vacuum-Plasma-Spray Gun (United States)

    Woodford, William H.; Mckechnie, Timothy N.; Power, Christopher A.; Daniel, Ronald L., Jr.


    Fixtures for alignment of vacuum-plasma-spray guns built. Each fixture designed to fit specific gun and holds small, battery-powered laser on centerline of gun. Laser beam projects small red dot where centerline intersects surface of workpiece to be sprayed. After laser beam positioned on surface of workpiece, fixture removed from gun and spraying proceeds.

  17. Homopolar Gun for Pulsed Spheromak Fusion Reactors II

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, T


    A homopolar gun is discussed that could produce the high currents required for pulsed spheromak fusion reactors even with unit current amplification and open field lines during injection, possible because close coupling between the gun and flux conserver reduces gun losses to acceptable levels. Example parameters are given for a gun compatible with low cost pulsed reactors and for experiments to develop the concept.

  18. Gun Violence, mental health, and Connecticut physicians. (United States)

    Dodds, Peter R; Anderson, Caitlyn O; Dodds, Jon H


    While there is a public perception that gun violence is associated with mental illness we present evidence that it is a complex public health problem which defies simple characterizations and solutions. Only a small percentage of individuals with mental illness are at risk for extreme violence and they account for only a small percentage of gun-related homicides. Individuals who are at risk for gun violence are difficult to identify and successfully treat. The incidence, and perhaps the demographics, of gun violence vary substantially from state to state. We make a case for Connecticut physicians to study gun violence at the state level. We recommend that Connecticut physicians promote and expand upon the American Academy of Pediatrics' recommendation for creating a "safe home environment. "We suggest that guns be secured in all homes in which there are children. In addition we suggest that guns be voluntarily removed from homes in which there are individuals with a history of violence, threats of violence, depression, drug and/or alcohol abuse, and individuals with major mental illnesses who are not cooperating with therapy.

  19. Evaluation of Smart Gun Technologies preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D.R.


    The Smart Gun Technology Project has a goal to eliminate the capability of an unauthorized user from firing a law enforcement officer`s firearm by implementing {open_quote}smart{close_quote} technologies. Smart technologies are those that can in some manner identify an officer. This report will identify, describe, and grade various technologies as compared to the requirements that were obtained from officers. This report does not make a final recommendation for a smart gun technology, nor does it give the complete design of a smart gun system.

  20. Texas youth stage rally against guns

    Institute of Scientific and Technical Information of China (English)

    Mary; Alice; Robbins; 李小平


    Young Texans Against Gun Violence rallied atthe State Capitol on Monday and called for the Legisla-ture to pass laws that would make it more difficult toget guns.“It is time for our state Legislature to pass laws tohelp protect us,”Marianne Moreno,a high school se-nior from the Dallas area,told a crowd of about 125students who attended the“Packing Peace Rally.”“As Texas law stands today,anyone—even acriminal—can walk into a gun show and purchase asemi-automatic weapon or any other type of firearm,...

  1. "Is there a gun in the home?" Assessing the risks of gun ownership in older adults. (United States)

    Pinholt, Ellen M; Mitchell, Joshua D; Butler, Jane H; Kumar, Harjinder


    An important ethical and safety concern that geriatricians, primary care providers, and home health professionals need to address is gun ownership by elderly adults. Those aged 65 and older now have the highest rate of gun ownership in America, and they also have a high prevalence of depression and suicide. Dementia can add additional layers of risk. Even older gun owners who are otherwise intellectually intact may benefit from information about gun safety with the increasing numbers of children being cared for by grandparents. Health professionals should ask patients, "Is there a gun in the home?" in the clinic and during home visits. Healthcare professionals must have knowledge and skills to address safe gun ownership in elderly adults. The 5 L's (Locked, Loaded, Little children, feeling Low, Learned owner) will assist professionals in addressing all aspects of safe ownership.

  2. Sound-resonance hydrogen sensor


    Dong, Shuxiang; Bai, Feiming; Li, Jiefang; Viehland, Dwight D.


    A hydrogen sensor is reported in which a small piezoelectric-sound-resonance-cavity (PSRC) is used as the sensing element. Detection utilizes sound resonance and acoustic property differences between H-2 and air as a sensing mechanism. Changes in H-2 concentration result in a shift of the sound-resonance state of the PSRC. Preliminary experiments have demonstrated a sensitivity limit of 8 ppm, a fast response time similar to1.5 second, and detection capabilities over a broad concentration ran...

  3. Fluid Sounds

    DEFF Research Database (Denmark)


    are tempo, time, voice, sound and music. Our goal is to bring analytical and performative awareness to academic means of expression, and the audio paper provides us with a new and experimental platform to do so. Our thoughts about and definition of the audio paper is explained in the first text of the issue...... by introducing a new format: The Audio Paper. The purpose of the audio paper is to extend the written academic text: to present discussions and explorations of a certain argument or problem in sound. The audio paper is an extension of expressive means: Not only words and syntax are means of expression – so...

  4. Direct launch using the electric rail gun (United States)

    Barber, J. P.


    The concept explored involves using a large single stage electric rail gun to achieve orbital velocities. Exit aerodynamics, launch package design and size, interior ballistics, system and component sizing and design concepts are treated. Technology development status and development requirements are identified and described. The expense of placing payloads in Earth orbit using conventional chemical rockets is considerable. Chemical rockets are very inefficient in converting chemical energy into payload kinetic energy. A rocket motor is relatively expensive and is usually expended on each launch. In addition specialized and expensive forms of fuel are required. Gun launching payloads directly to orbit from the Earth's surface is a possible alternative. Guns are much more energy efficient than rockets. The high capital cost of the gun installation can be recovered by reusing it over and over again. Finally, relatively inexpensive fuel and large quantities of energy are readily available to a fixed installation on the Earth's surface.

  5. The electric rail gun for space propulsion (United States)

    Bauer, D. P.; Barber, J. P.; Vahlberg, C. J.


    An analytic feasibility investigation of an electric propulsion concept for space application is described. In this concept, quasistatic thrust due to inertial reaction to repetitively accelerated pellets by an electric rail gun is used to propel a spacecraft. The study encompasses the major subsystems required in an electric rail gun propulsion system. The mass, performance, and configuration of each subsystem are described. Based on an analytic model of the system mass and performance, the electric rail gun mission performance as a reusable orbital transfer vehicle (OTV) is analyzed and compared to a 30 cm ion thruster system (BIMOD) and a chemical propulsion system (IUS) for payloads with masses of 1150 kg and 2300 kg. For system power levels in the range from 25 kW(e) to 100 kW(e) an electric rail gun OTV is more attractive than a BIMOD system for low Earth orbit to geosynchronous orbit transfer durations in the range from 20 to 120 days.

  6. Arc-driven rail gun research (United States)

    Ray, P. K.


    The equations describing the performance of an inductively-driven rail gun are analyzed numerically. Friction between the projectile and rails is included through an empirical formulation. The equations are applied to the experiment of Rashleigh and Marshall to obtain an estimate of energy distribution in rail guns as a function of time. The effect of frictional heat dissipation on the bore of the gun is calculated. The mechanism of plasma and projectile acceleration in a dc rail gun is described from a microscopic point of view through the establishment of the Hall field. The plasma conductivity is shown to be a tensor indicating that there is a small component of current parallel to the direction of acceleration. The plasma characteristics are evaluated as a function of plasma mass through a simple fluid mechanical analysis of the plasma. By equating the energy dissipated in the plasma with the radiation heat loss, the properties of the plasma are determined.

  7. Waterfowl habitat survey : Canvasback Gun Club : 1964 (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a survey of the submergent and emergent aquatics growing in the marsh on the Canvasback Gun Club in Nevada. The marsh portion of the...

  8. Waterfowl habitat survey : Canvasback Gun Club : 1962 (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is about an investigation that was done to determine the quantity and species of submergent vegetation in the marsh area on the Canvasback Gun Club in...

  9. Waterfowl habitat survey : Canvasback Gun Club : 1972 (United States)

    US Fish and Wildlife Service, Department of the Interior — Since the last vegetative survey in 1965, the marsh at Canvasback Gun Club has remained virtually unchanged. The Arthur-Johnson Ponds produced most of the waterfowl...

  10. Waterfowl habitat survey : Canvasback Gun Club : 1963 (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a survey of the submergent and emergent aquatics growing in the marsh on the Canvasback Gun Club in Nevada. The marsh portion of the...

  11. Uudised : Guns N' Roses Soomes. Valmis ulmeraadio

    Index Scriptorium Estoniae


    Ameerika hard-rock-bändi Guns N' Roses kontserdist 5. juulil Hartwall Areenal Soomes. Kord kuus on Ulmeplaatide kodulehekülel www. võimalus kuulata ulmeraadiot, kus esitusel eesti kergemuusika

  12. Waterfowl habitat survey : Canvasback Gun Club : 1965 (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a survey of the submergent and emergent aquatics growing in the marsh on the Canvasback Gun Club in Nevada. As stated in previous years of...

  13. Ballistic Rail Gun Soft Recovery Facility (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...

  14. Detonator assembly for oil well perforating gun

    Energy Technology Data Exchange (ETDEWEB)

    Regalbuto, J.A.


    A safe/arm detonator assembly for use with an oil well perforating gun assembly has 2 housing members isolated from well-bore fluid which are rotatable from a safe position wherein a detonator and a booster are held out of alignment, to an armed position wherein the detonator and booster are moved into alignment. The detonator assembly is further arranged to be installed in a well perforating gun assembly such that the gun assembly may be transported with the detonator assembly in the safe position, and rotated to the armed position at the well site without disassembling the gun assembly. A safety pin may protrude from one of the housing members across a cavity between the members to cover and protect the booster from accidental detonation when the detonator assembly is in the safe position. The detonator and booster cavities may be held aligned by a detent ball. 16 claims.

  15. RF Electron Gun with Driven Plasma Cathode

    CERN Document Server

    Khodak, Igor


    It's known that RF guns with plasma cathodes based on solid-state dielectrics are able to generate an intense electron beam. In this paper we describe results of experimental investigation of the single cavity S-band RF gun with driven plasma cathode. The experimental sample of the cathode based on ferroelectric ceramics has been designed. Special design of the cathode permits to separate spatially processes of plasma development and electron acceleration. It has been obtained at RF gun output electron beam with particle energy ~500 keV, pulse current of 4 A and pulse duration of 80 ns. Results of experimental study of beam parameters are referred in. The gun is purposed to be applied as the intense electron beam source for electron linacs.

  16. Arc Plasma Gun With Coaxial Powder Feed (United States)

    Zaplatynsky, Isidor


    Redesigned plasma gun provides improved metallic and ceramic coatings. Particles injected directly through coaxial bore in cathode into central region of plasma jet. Introduced into hotter and faster region of plasma jet.

  17. Sound Settlements

    DEFF Research Database (Denmark)

    Mortensen, Peder Duelund; Hornyanszky, Elisabeth Dalholm; Larsen, Jacob Norvig;


    Præsentation af projektresultater fra Interreg forskningen Sound Settlements om udvikling af bæredygtighed i det almene boligbyggerier i København, Malmø, Helsingborg og Lund samt europæiske eksempler på best practice...

  18. Unsound Sound

    DEFF Research Database (Denmark)

    Knakkergaard, Martin


    This article discusses the change in premise that digitally produced sound brings about and how digital technologies more generally have changed our relationship to the musical artifact, not simply in degree but in kind. It demonstrates how our acoustical conceptions are thoroughly challenged...

  19. Cobalt-Base Alloy Gun Barrel Study (United States)


    are presented in Section 5. 2. Materials and methods The composition of the cobalt -base alloy (CBA) is presented in Table 1. The production of this... Cobalt -Base Alloy Gun Barrel Study by William S. de Rosset and Jonathan S. Montgomery ARL-RP-0491 July 2014 A reprint...21005-5069 ARL-RP-0491 July 2014 Cobalt -Base Alloy Gun Barrel Study William S. de Rosset and Jonathan S. Montgomery Weapons and Materials

  20. Modelling Effectiveness of Machine Gun Fire


    Dutta, D.; S. Sabhanval


    Machine gun is an effective infantry weapon which can cause heavy damage to enemy targets, if sited in a tactically favourable position. It can be engaged effectively against both static and moving targets. The paper deals with the determination of target vulnerability under effective machine gun fire considering relevant tactical parameters, eg, target aiming point, trajectory of fire, sweep angle, target frontage, posture, direction of attack, etc.

  1. Modelling Effectiveness of Machine Gun Fire

    Directory of Open Access Journals (Sweden)

    D. Dutta


    Full Text Available Machine gun is an effective infantry weapon which can cause heavy damage to enemy targets, if sited in a tactically favourable position. It can be engaged effectively against both static and moving targets. The paper deals with the determination of target vulnerability under effective machine gun fire considering relevant tactical parameters, eg, target aiming point, trajectory of fire, sweep angle, target frontage, posture, direction of attack, etc.

  2. The main factors influencing the quality of upper air sounding and the counter measures%影响高空探测质量主要因素及应对措施

    Institute of Scientific and Technical Information of China (English)



    The main factors affecting the quality of upper air sounding was discussed from the practical work in this article, and suggestions were put forward. It showed that radar calibration methods, radar observations of environment, base point resistance of humidity and measuring data accuracy,the accuracy of the instant meteorological elements, etc were all important factors affecting the quality of upper air sounding data. Adopting scientific radar calibration methods, accurately determine station radar detection performance,the base point of resistance,the base value determination and cast instant data automation,the second correction of stations, all these measures would provide technical guarantee to improve the quality of upper air sounding.%文章从实际工作出发对影响高空探测质量的主要因素进行了讨论,提出了措施建议. 研究表明,雷达标定方法、雷达观测环境、湿度基点电阻和基测数据准确性、施放瞬间气象要素的准确性都是影响高空资料质量的重要因素. 采用科学的雷达标定方法、确定测站雷达的探测性能、基点电阻、基值测定和施放瞬间数据自动化、台站二次订正等措施是提高高空探测质量的技术保证.

  3. Turboatomizador e repasse com pistola manual na cobertura de pulverização de agrotóxicos em caquizeiro (Diospyros kaki L.f. Air-jet sprayer and spray gun in the pesticide spray coverage of persimmon (Diospyros kaki L.f. trees

    Directory of Open Access Journals (Sweden)

    Leandro Riyuiti Higashibara


    na superfície abaxial das folhas, independentemente da posição destas na planta (interna ou externa. Houve efeito do repasse com pistola na cobertura da superfície abaxial das folhas situadas na posição interna, mas não na externa à planta. Considerando que a maioria dos agentes causadores de danos fitossanitários inicia a ocorrência na superfície abaxial das folhas, pode-se concluir que o repasse manual foi mais eficiente do que o aumento da taxa de aplicação, visando à cobertura nas folhas posicionadas no interior da planta.Persimmon crop is growing in importance in Brazil, and with the increase of the production area there also has been an increase in the problems related to diseases and pests. For the control and prevention of these problems, most often it is used pesticides spray, and one of the main techniques is the spray with the aid of air flow. The objective of this study was to evaluate the effects of changes in the application rate and transfer with a spray gun on the leaves mixture coverage. The spraying was performed using tractor and air flow sprayer. The application was performed with two forward speeds of the equipment, leading to different application rates. The transfer was made with a spray gun attached to the same equipment. For the assessment of the coverage it was used a mixture prepared with fluorescent tracer dissolved in water. Leaves were collected in the inside and outside of the tree. Later, in dark room with ultraviolet lighting to highlight the area affected by the fluorescent tracer, the upper and lower surfaces of each leaf were photographed with a digital camera. Each image was subjected to analysis generated by software SIARCS 3.0, resulting in percentage of coverage. It was used a randomized block design with subdivided parcels with four replications, being the treatments in a 2x2x2 factorial scheme (high or low application rate, with or without transfer, inside or outside the tree. The evaluations were made in the

  4. Gun Carrying by High School Students in Boston, MA: Does Overestimation of Peer Gun Carrying Matter? (United States)

    Hemenway, David; Vriniotis, Mary; Johnson, Renee M.; Miller, Matthew; Azrael, Deborah


    This paper investigates: (1) whether high school students overestimate gun carrying by their peers, and (2) whether those students who overestimate peer gun carrying are more likely to carry firearms. Data come from a randomly sampled survey conducted in 2008 of over 1700 high school students in Boston, MA. Over 5% of students reported carrying a…

  5. Fluid Sounds

    DEFF Research Database (Denmark)

    Explorations and analysis of soundscapes have, since Canadian R. Murray Schafer's work during the early 1970's, developed into various established research - and artistic disciplines. The interest in sonic environments is today present within a broad range of contemporary art projects and in arch...... are tempo, time, voice, sound and music. Our goal is to bring analytical and performative awareness to academic means of expression, and the audio paper provides us with a new and experimental platform to do so....... by introducing a new format: The Audio Paper. The purpose of the audio paper is to extend the written academic text: to present discussions and explorations of a certain argument or problem in sound. The audio paper is an extension of expressive means: Not only words and syntax are means of expression – so...

  6. How to Use a Candle to Study Sound Waves (United States)

    Carvalho, P. Simeão; Briosa, E.; Rodrigues, M.; Pereira, C.; Ataíde, M.


    It is well known that sound waves in air are longitudinal waves. Although teachers use analogies such as compressing horizontal springs to demonstrate what longitudinal waves look like, students still present some difficulty in understanding that (1) sound waves correspond to oscillations of air particles, and (2) there is no "air flow"…

  7. Magnetic Fields Can Control Heat and Sound (United States)


    sound waves , which then propagate through the air until they hit a listener’s eardrums and make them vibrate as well. From these vibrations , the listener... vibrations as particles. This is similar to the concept of light as both a wave and a particle we call a photon. Physicists called the sound wave ...Physics, and Materials Science & Engineering at The Ohio State University Sound is carried by periodic vibrations of atoms in gases, liquids and

  8. Development of plasma cathode electron guns (United States)

    Oks, Efim M.; Schanin, Peter M.


    The status of experimental research and ongoing development of plasma cathode electron guns in recent years is reviewed, including some novel upgrades and applications to various technological fields. The attractiveness of this kind of e-gun is due to its capability of creating high current, broad or focused beams, both in pulsed and steady-state modes of operation. An important characteristic of the plasma cathode electron gun is the absence of a thermionic cathode, a feature which leads to long lifetime and reliable operation even in the presence of aggressive background gas media and at fore-vacuum gas pressure ranges such as achieved by mechanical pumps. Depending on the required beam parameters, different kinds of plasma discharge systems can be used in plasma cathode electron guns, such as vacuum arcs, constricted gaseous arcs, hollow cathode glows, and two kinds of discharges in crossed E×B fields: Penning and magnetron. At the present time, plasma cathode electron guns provide beams with transverse dimension from fractional millimeter up to about one meter, beam current from microamperes to kiloamperes, beam current density up to about 100 A/cm2, pulse duration from nanoseconds to dc, and electron energy from several keV to hundreds of keV. Applications include electron beam melting and welding, surface treatment, plasma chemistry, radiation technologies, laser pumping, microwave generation, and more.

  9. Progress of the Rossendorf SRF Gun Project

    CERN Document Server

    Teichert, J; Büttig, H; Janssen, D; Lehnert, U; Michel, P; Möller, K; Murcek, P; Schneider, C; Schurig, R; Staufenbiel, F; Xiang, R


    A superconducting rf photo electron injector (SRF gun) is under development at the Forschungszentrum Rossendorf. The project aims at several issues: improvement of the beam quality for the ELBE superconducting electron linac, demonstration of feasibility of this gun type, investigation of critical components, and parameter studies for future application (BESSY-FEL, 4GLS). In 2005, a substantial progress has been made. The two 3.5-cell niobium cavities for the gun have been delivered from the company ACCEL. The main parts for gun cryostat like vacuum vessel, cryogenic and magnetic shields are ready. Test benches for the cathode cooling system and the cavity tuner are being assembled. The photo cathode preparation lab has been arranged, and the diagnostic beam line has been designed (see T. Kamps et al., this conference). After delivering the gun cavities, their rf properties are being measured at room temperature and the warm tuning is being carried out. The set-up for this treatment and measurement as well as...

  10. The Adhesion and Formation Mechanism of Blast Furnace Gunning Layer

    Institute of Scientific and Technical Information of China (English)


    Basing on the study of the equilibrium relationship of interfacial tension among gunning particles, repaired surface and atmosphere, this test is in a position to draw a conclusion concerning the adhesion mechanism of the gunning refractory and the repaired surface, which illustrates the formation of the bottom gunning layer by moist fine gunning particles on the repaired surface. Also involved within the scope of discussion and probe are the patterns formed under this contacting effect and the formation mechanism of gunning layer. The analytic research regarding the behavior of gunning interface has ascribed the influence upon adhesion intensity to the quality of furnace gunning refractory, the state of the repaired surface and the gunning techniques.

  11. Mole guns in Turkey in 2003-2005. (United States)

    Yilmaz, Riza; Birincioğlu, Ismail; Cakir, Ismail; Uner, H Bülent; Açikgöz, Dinç; Seçkin, Cetin


    This study describes the frequency of mole guns in Turkey by examining the cases sent to the Council of Forensic Medicine of Turkey between 2003 and 2005. In total, 11 mole guns were examined. Mole guns are manufactured to be used as a trap against detrimental animals. Although they are not meant to be used as a firearm, they are able to cause death. Mole guns appearing in regular casework were evaluated in terms of type of the gun, number of barrels, size and caliber, rifling, design, mechanism, fitness for use, legality, and geographical distribution. Ninety-one percent of the guns were 12 gauge. Most commonly they originate from Inner Anatolia. Mole guns are typically handmade. Some examples of injuries and deaths caused by mole guns are also offered.

  12. Improved Methodology for Surface and Atmospheric Soundings, Error Estimates, and Quality Control Procedures: the AIRS Science Team Version-6 Retrieval Algorithm (United States)

    Susskind, Joel; Blaisdell, John; Iredell, Lena


    The AIRS Science Team Version-6 AIRS/AMSU retrieval algorithm is now operational at the Goddard DISC. AIRS Version-6 level-2 products are generated near real-time at the Goddard DISC and all level-2 and level-3 products are available starting from September 2002. This paper describes some of the significant improvements in retrieval methodology contained in the Version-6 retrieval algorithm compared to that previously used in Version-5. In particular, the AIRS Science Team made major improvements with regard to the algorithms used to 1) derive surface skin temperature and surface spectral emissivity; 2) generate the initial state used to start the cloud clearing and retrieval procedures; and 3) derive error estimates and use them for Quality Control. Significant improvements have also been made in the generation of cloud parameters. In addition to the basic AIRS/AMSU mode, Version-6 also operates in an AIRS Only (AO) mode which produces results almost as good as those of the full AIRS/AMSU mode. This paper also demonstrates the improvements of some AIRS Version-6 and Version-6 AO products compared to those obtained using Version-5.

  13. The Real Costs of Gun Violence

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Philip J. (Duke University)


    I will report some of the results in my new book, 'Gun Violence: The Real Costs' (Oxford University Press, 2000; with Jens Ludwig). The problem of gun violence is usually summarized by statistics on deaths and injuries. Those statistics tell only part of the story. All of us bear some of the burden of gun violence, at least in the form of higher taxes and waiting to go through the airport security checks. But that's just the beginning. The extraordinary reductions in lethal violence that occurred during the 1990s help account for rising property values and urban renewal; further reductions are possible and would do still more to enhance the average standard of living. This talk will explain why the economic perspective provides a fresh, useful point of view on violence, and will discuss the technique used to arrive at an estimate of the magnitude of the burden.

  14. Secondary emission electron gun using external primaries (United States)

    Srinivasan-Rao, Triveni; Ben-Zvi, Ilan; Kewisch, Jorg; Chang, Xiangyun


    An electron gun for generating an electron beam is provided, which includes a secondary emitter. The secondary emitter includes a non-contaminating negative-electron-affinity (NEA) material and emitting surface. The gun includes an accelerating region which accelerates the secondaries from the emitting surface. The secondaries are emitted in response to a primary beam generated external to the accelerating region. The accelerating region may include a superconducting radio frequency (RF) cavity, and the gun may be operated in a continuous wave (CW) mode. The secondary emitter includes hydrogenated diamond. A uniform electrically conductive layer is superposed on the emitter to replenish the extracted current, preventing charging of the emitter. An encapsulated secondary emission enhanced cathode device, useful in a superconducting RF cavity, includes a housing for maintaining vacuum, a cathode, e.g., a photocathode, and the non-contaminating NEA secondary emitter with the uniform electrically conductive layer superposed thereon.

  15. Secondary emission electron gun using external primaries (United States)

    Srinivasan-Rao, Triveni; Ben-Zvi, Ilan


    An electron gun for generating an electron beam is provided, which includes a secondary emitter. The secondary emitter includes a non-contaminating negative-electron-affinity (NEA) material and emitting surface. The gun includes an accelerating region which accelerates the secondaries from the emitting surface. The secondaries are emitted in response to a primary beam generated external to the accelerating region. The accelerating region may include a superconducting radio frequency (RF) cavity, and the gun may be operated in a continuous wave (CW) mode. The secondary emitter includes hydrogenated diamond. A uniform electrically conductive layer is superposed on the emitter to replenish the extracted current, preventing charging of the emitter. An encapsulated secondary emission enhanced cathode device, useful in a superconducting RF cavity, includes a housing for maintaining vacuum, a cathode, e.g., a photocathode, and the non-contaminating NEA secondary emitter with the uniform electrically conductive layer superposed thereon.

  16. Simulations of Gaussian electron guns for RHIC electron lens

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.


    Simulations of two versions of the electron gun for RHIC electron lens are presented. The electron guns have to generate an electron beam with Gaussian radial profile of the electron beam density. To achieve the Gaussian electron emission profile on the cathode we used a combination of the gun electrodes and shaping of the cathode surface. Dependence of electron gun performance parameters on the geometry of electrodes and the margins for electrodes positioning are presented.

  17. Dynamic Simulation of the Tank Gun Recoil Response

    Institute of Scientific and Technical Information of China (English)

    XING Jun-wen; WANG Liang-xi; SHI Yan; CHEN Chun-liang


    By using the ATV module of MSC. ADAMS, the dynamic simulation of recoil response of tank gun is analyzed.How the recoil force affects the bodywork and the suspension during gun firing, as well as the changing status of the gun muzzle's velocity are gained. All results and analyzing methods are offered for the designing basis of optimizing tank vehicle-gun match. The constructive exploration is beneficial to improving the general capability of tank.

  18. Improved DC Gun and Insulator Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Neubauer, Michael [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)


    Many user facilities such as synchrotron radiation light sources and free electron lasers rely on DC high voltage photoguns with internal field gradients as high as 10 to 15 MV/m. These high gradients often lead to field emission which poses serious problems for the photocathode used to generate the electron beam and the ceramic insulators used to bias the photocathode at high voltage. Ceramic insulators are difficult to manufacture, require long commissioning times, and have poor reliability, in part because energetic electrons bury themselves in the ceramic causing a buildup of charge and eventual puncture, and also because large diameter ceramics are difficult to braze reliably. The lifetimes of photo cathodes inside high current DC guns exhibiting field emission are limited to less than a hundred hours. Reducing the surface gradients on the metals reduces the field emission, which serves to maintain the required ultrahigh vacuum condition. A novel gun design with gradients around 5 MV/m and operating at 350 kV, a major improvement over existing designs, was proposed that allows for the in-situ replacement of photo cathodes in axially symmetric designs using inverted ceramics. In this project, the existing JLAB CEBAF asymmetric gun design with an inverted ceramic support was modeled and the beam dynamics characterized. An improved structure was designed that reduces the surface gradients and improves the beam optics. To minimize the surface gradients, a number of electrostatic gun designs were studied to determine the optimum configuration of the critical electrodes within the gun structure. Coating experiments were carried out to create a charge dissipative coating for cylindrical ceramics. The phase II proposal, which was not granted, included the design and fabrication of an axially symmetric DC Gun with an inverted ceramic that would operate with less than 5 MV/m at 350 kV and would be designed with an in-situ replaceable photo-cathode.

  19. 78 FR 12720 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to... (United States)


    ... suspension of air gun activity, pending investigation, if any beluga strandings occur within or within an... marine mammal strandings and the sounds produced by air guns are quite different from sound sources...

  20. What is the sound?

    Directory of Open Access Journals (Sweden)

    Seyyed Zia Taheri


    Full Text Available Human being is exponentially devoting attention to his environment since the 20th century. This has led in taking the air pollution seriously. Noise pollution as some kind of air pollution is excessive, displeasing human, animal or machine-created environmental noise that disrupts the activity or balance of human or animal life. The word noise comes from the Latin word nauseas, meaning seasickness. Noise can have a detrimental effect on animals by causing stress and increasing risk of death. In the current article we are aimed at defining the expression of noise and mentioning its differences with sound and then description of the mechanism of transferring noise in the human auditory system.

  1. Guns N’ Arenas黑枪事件

    Institute of Scientific and Technical Information of China (English)



    奇才队"零号探员"阿里纳斯(Gilbert Arenas)和知名摇滚乐团"枪和玫瑰(Guns N’Roses)"同样发迹于美国加州,但当"枪和阿里纳斯(Guns N’Are nas)"连结在一起时,代志就大条了!先前名气直逼摇滚巨星的阿里纳斯,恐怕将因去年12月的"黑枪事件"身败名裂!


    Directory of Open Access Journals (Sweden)

    M.S. Farahvash


    Full Text Available in ordere to determine the prognosis of perforating eye injuries caused hy BB guns in our patients, the"nvisual and anatomic results of 14 patients with gun injuries seen between September 1996 and February 1998 in Farafti Hospital and private office in Tehran were reviewed. Five patients liad nonn erf orating eye injuries. All perforated eyes underwent scleral buckling, tenseclomy, vitrectomy ami silicone injection. All injured iyes had a visual acuity of light perception or better at presentation. Among 9 cases of perforating injuries. 7 had doable and 2 had single perforation. All patients had a final.

  3. Frequency of Guns in the Households of High School Seniors (United States)

    Coker, Ann L.; Bush, Heather M.; Follingstad, Diane R.; Brancato, Candace J.


    Background: In 2013, President Obama lifted the federal ban on gun violence research. The current study provides one of the first reports to estimate household gun ownership as reported by youth. Methods: In this cohort study of 3,006 high school seniors from 24 schools, we examined the frequency of household guns ownership. Results: About 65%…

  4. Should Gun Safety Be Taught in Schools? Perspectives of Teachers (United States)

    Obeng, Cecilia


    Background: Gun-related injuries and deaths among children occur at disproportionately high rates in the United States. Children who live in homes with guns are the most likely victims. This study describes teachers' views on whether gun safety should be taught to children in the preschool and elementary years. Methods: A total of 150 survey…

  5. Demand Analysis of Informational Shipboard Gun Weapon System Interface Design

    Directory of Open Access Journals (Sweden)

    WANG Hui-chuan


    Full Text Available According to development demand of informational shipboard gun weapon system, design concept of shipboard gun weapon system interface is proposed. System composition is put forward and function demand of interface is analyzed from combat, training and detection aspects. General principle need to be followed in design process. A new concept is provided for development of shipboard gun weapon system interface.

  6. Study of Control Grid Thermionic Cathode RF Gun

    CERN Document Server

    Xiao, Jin; Ming, Li; Xinfan, Yang; Xumin, Shen; Yanan, Chen; Zhou, Xu


    In this paper, the beam loading effect of RF Gun was analyzed. To minimize the energy spread, the grid control RF Gun was introduced. The result shows that the grid congrol RF Gun can increase electron beam within 1% energy spread.

  7. 78 FR 11902 - Review of Gun Safety Technologies (United States)


    ... of Justice Programs Review of Gun Safety Technologies AGENCY: National Institute of Justice, JPO, DOJ...) is conducting a review of existing and emerging gun safety technologies and plans to issue a report... to help inform its technology assessment and market research of existing and emerging gun...

  8. Numerical Analysis for Impact of Sound Absorption Treatment on Ship Cabin Noise Radiated from Air-conditioning System%吸声处理对舱室空调噪声影响的数值分析

    Institute of Scientific and Technical Information of China (English)

    武耀; 季振林


    Air-conditioning system is a major noise source in ship cabin, and sound-absorption treatment is an efficient way to reduce the cabin noise. In order to examine the effect of sound-absorption on the noise reduction in cabin, the finite element predictive model of noise radiated from the ventilation pipe into the ship cabin was established. Taking the measured sound pressure as the noise source, the effects of sound-absorption of cabin wall and ventilation pipe on the ship cabin noise reduction were investigated, which was used to guide and improve the acoustic design of ship cabin. The cabin noise caused by the improved air-conditioning system was predicted, and the acoustic design for suppression of much higher noise was conducted, a satisfactory solution for reducing the noise level in cabin was obtained.%  通风空调系统辐射噪声是船舶舱室内最主要的噪声源,吸声处理是降低舱室噪声的一种有效途径。为考察吸声处理对降低舱室噪声的效果,建立通风空调管路噪声向船舶舱内辐射的有限元法数值预报模型。以实测的管口声压为噪声源,研究舱室壁面及通风管路吸声对舱室降噪效果的影响,进而用于指导和改进船舶舱室的声学设计。对通风空调系统改变后的舱室噪声进行预报,并针对较高的噪声进行声学设计,使舱室噪声问题得到解决。

  9. Sound knowledge

    DEFF Research Database (Denmark)

    Kauffmann, Lene Teglhus

    at different bureaucratic levels and among researchers in university departments and research institutes. Researchers had a range of disciplinary backgrounds, in anthropology, sociology, public health, education and health economy, all bringing different ideas about the construction of knowledge to health...... of the research is to investigate what is considered to ‘work as evidence’ in health promotion and how the ‘evidence discourse’ influences social practices in policymaking and in research. From investigating knowledge practices in the field of health promotion, I develop the concept of sound knowledge...... as knowledge based on reflexive practices. I chose ‘health promotion’ as the field for my research as it utilises knowledge produced in several research disciplines, among these both quantitative and qualitative. I mapped out the institutions, actors, events, and documents that constituted the field of health...

  10. Sound Search Engine Concept

    DEFF Research Database (Denmark)


    Sound search is provided by the major search engines, however, indexing is text based, not sound based. We will establish a dedicated sound search services with based on sound feature indexing. The current demo shows the concept of the sound search engine. The first engine will be realased June...

  11. Performance of a carbon nanotube field emission electron gun (United States)

    Getty, Stephanie A.; King, Todd T.; Bis, Rachael A.; Jones, Hollis H.; Herrero, Federico; Lynch, Bernard A.; Roman, Patrick; Mahaffy, Paul


    A cold cathode field emission electron gun (e-gun) based on a patterned carbon nanotube (CNT) film has been fabricated for use in a miniaturized reflectron time-of-flight mass spectrometer (RTOF MS), with future applications in other charged particle spectrometers, and performance of the CNT e-gun has been evaluated. A thermionic electron gun has also been fabricated and evaluated in parallel and its performance is used as a benchmark in the evaluation of our CNT e-gun. Implications for future improvements and integration into the RTOF MS are discussed.

  12. Toward a terahertz-driven electron gun (United States)

    Huang, W. Ronny; Nanni, Emilio A.; Ravi, Koustuban; Hong, Kyung-Han; Fallahi, Arya; Wong, Liang Jie; Keathley, Phillip D.; Zapata, Luis E.; Kärtner, Franz X.


    Femtosecond electron bunches with keV energies and eV energy spread are needed by condensed matter physicists to resolve state transitions in carbon nanotubes, molecular structures, organic salts, and charge density wave materials. These semirelativistic electron sources are not only of interest for ultrafast electron diffraction, but also for electron energy-loss spectroscopy and as a seed for x-ray FELs. Thus far, the output energy spread (hence pulse duration) of ultrafast electron guns has been limited by the achievable electric field at the surface of the emitter, which is 10 MV/m for DC guns and 200 MV/m for RF guns. A single-cycle THz electron gun provides a unique opportunity to not only achieve GV/m surface electric fields but also with relatively low THz pulse energies, since a single-cycle transform-limited waveform is the most efficient way to achieve intense electric fields. Here, electron bunches of 50 fC from a flat copper photocathode are accelerated from rest to tens of eV by a microjoule THz pulse with peak electric field of 72 MV/m at 1 kHz repetition rate. We show that scaling to the readily-available GV/m THz field regime would translate to monoenergetic electron beams of ~100 keV. PMID:26486697

  13. Guns on Campus: A Chilling Effect (United States)

    Mash, Kenneth M.


    The author of this article observes that, while much has been written on the overall topic of safety with regard to allowing guns on college campuses, little has been said about how allowing the possession of deadly weapons can create a "chilling effect" on academic discussions. This article considers how some universities have…

  14. Nerf Guns Strike a Nerve on Campuses (United States)

    Young, Jeffrey R.


    Killing zombies on campus just isn't as much fun as it used to be. Students at Bowling Green State University once carried Nerf guns for a week each semester, shooting the zombies before the creatures could tag them. Participants were seen by most bystanders as nerdy but harmless kids who liked role-playing. These days, bright plastic Nerf guns…

  15. Cerebral damage caused by nail gun injury

    Directory of Open Access Journals (Sweden)

    Andersen Chris Hedeman


    Full Text Available Background Accidents with nail guns are rather common, especially in the construction industry. Most injuries involve the extremities and several present with intracerebral injuries. When the patient is unconscious, it can be a big challenge to determine whether the injury is an accident, self-inflicted or a criminal act.

  16. Safety Plan for Schools: No Guns (United States)

    Shah, Nirvi


    In a pre-emptive move against a school safety proposal from the National Rifle Association that is expected to include a call for more people trained and approved to carry guns at schools, a coalition of civil rights and education groups unveiled its own safety plan last week. It seeks the creation of positive school climates, thoughtful and…

  17. Magnetic guns with cylindrical permanent magnets

    DEFF Research Database (Denmark)

    Vokoun, David; Beleggia, Marco; Heller, Luděk


    The motion of a cylindrical permanent magnet (projectile) inside a tubular permanent magnet, with both magnets magnetized axially, illustrates nicely the physical principles behind the operation of magnetic guns. The force acting upon the projectile is expressed semi-analytically as derivative...

  18. Gun Trafficking and the Southwest Border (United States)


    Source of Narco Syndicates Rising Firepower,” Narcosphere, March 29, 2009. Gun Trafficking and the Southwest Border Congressional Research...50 years old, of museum interest, or derive a substantial amount of their value from the fact that they are novel , rare, bizarre, or because they

  19. Capital Punishment, Gun Ownership, and Homicide. (United States)

    Kleck, Gary


    Examines two controversial questions related to the problem of interpersonal violence in America: (1) Does use of the death penalty exert any measurable influence on the rate of homicide in the United States? (2) What relationship, if any, exists between the level of gun ownership and the level of homicide violence? (Author)

  20. College Students Opinions on Gun Violence. (United States)

    Lewis, Rhonda K; LoCurto, Jamie; Brown, Kyrah; Stowell, David; Maryman, J'Vonnah; Dean, Amber; McNair, Thoi; Ojeda, Debbie; Siwierka, Julia


    Gun violence and control issues have become serious public health problems. This study gathered the opinions from 419 college students from a Midwestern University. Participants were asked about beliefs about purchasing assault weapons, beliefs about bringing handguns to college campuses and beliefs about contributing factors that lead to gun violence. Participants completed surveys online. The findings showed that overall 54 % of respondents believed that military assault weapons should be banned and 53 % agree that teachers should be allowed to carry a registered handgun on campus. There were statistically significant differences between males and females on these issues. For instance, females believed military assault weapons and high capacity magazines should be banned more than 1.9 times (p = .004) p gun violence were decline in parenting and family values (17 %), gang involvement (14 %), bullying (13.8 %) and guns being easy to obtain (13.8 %). Limitations and implications for policy work are discussed.

  1. Microwave electron gun theory and experiments (United States)

    Gao, J.


    A general microwave electron gun (rf gun) theory and some new ideas about further reducing the emittance of electron beams are reviewed and introduced briefly. Experimental results are presented from a thermionic cathode rf gun which has been developed for Beijing Free-Electron Laser Project (BFELP) at Institute of High Energy Physics (IHEP), Academia Sinica as the injector of 30 MeV constant gradient linac. LaB6 is used as the thermionic emitter with 100 crystal surface and the temperature around 1620 °C. Back bombardment heating effect and another effect connected with the cathode surface temperature was observed. An electron beam with macropulse length 4 μs, repetition rate 12.5 Hz, greater than 500 mA beam current during macropulse and around 1 MeV maximum energy has been obtained. In the last section of this article, two useful formulas used to determine electric field distribution near the cathode surface and coupling coefficient β of a rf gun are introduced.

  2. How Sociology Texts Address Gun Control (United States)

    Tonso, William R.


    William R. Tonso has chosen an issue that he knows something about to examine how sociology textbooks address controversy. Appealing for gun control is fashionable, but it is at odds with a fondness that ordinary Americans have for their firearms--one that is supported by a growing body of research on deterrence to crime. There are two sides to…

  3. Green plasticizers for multibase gun propellants (Lecture)

    NARCIS (Netherlands)

    Schoolderman, C.; Driel, C.A. van; Zebregs, M.


    TNO Defence, Security and Safety has a long history of research on gun propellants. Areas investigated are formulating (new ingredients, optimization), manufacturing, charge design and lifetime assessment [1,2,3,4,5]. In conventional propellants inert plasticizers are used to alter performance, proc

  4. Grip-Pattern Recognition for Smart Guns

    NARCIS (Netherlands)

    Kauffman, J.A.; Bazen, A.M.; Gerez, S.H.; Veldhuis, R.N.J.


    This paper describes the design, implementation and evaluation of a user-verification system for a smart gun, which is based on grip-pattern recognition. An existing pressure sensor consisting of an array of 44 x 44 piezoresistive elements has been used. An interface has been developed to acquire pr

  5. Gas powered fluid gun with recoil mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Grubelich, Mark C.; Yonas, Gerold


    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided by a cavitating venturi that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated.

  6. RF Gun Photocathode Research at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Jongewaard, E.; Akre, R.; Brachmann, A.; Corbett, J.; Gilevich, S.; Grouev, K.; Hering, P.; P.Krejcik,; Lewandowski, J.; Loos, H.; Montagne, T.; Sheppard, J.C.; Stefan, P.; Vlieks, A.; Weathersby, S.; Zhou, F.; /SLAC


    LCLS is presently operating with a third copper photocathode in the original rf gun, with a quantum efficiency (QE) of {approx}1 x 10{sup -4} and projected emittance {gamma}{var_epsilon}{sub x,y} = 0.45 {micro}m at 250 pC bunch charge. The spare LCLS gun is installed in the SLAC Accelerator Structure Test Area (ASTA), fully processed to high rf power. As part of a wider photocathode R and D program, a UV laser system and additional gun diagnostics are being installed at ASTA to measure QE, QE lifetime, and electron beam emittance under a variety of operating conditions. The near-term goals are to test and verify the spare photocathode production/installation sequence, including transfer from the final holding chamber to the rf gun. Mid- and longer-term goals include development of a rigorous understanding of plasma and laser-assisted surface conditioning and investigation of new, high-QE photocathode materials. In parallel, an x-ray photoemission spectroscopy station is nearing completion, to analyze Cu photocathode surface chemistry. In this paper we review the status and anticipated operating parameters of ASTA and the spectroscopy test chamber.

  7. Simulation of sound waves using the Lattice Boltzmann Method for fluid flow: Benchmark cases for outdoor sound propagation

    NARCIS (Netherlands)

    Salomons, E.M.; Lohman, W.J.A.; Zhou, H.


    Propagation of sound waves in air can be considered as a special case of fluid dynamics. Consequently, the lattice Boltzmann method (LBM) for fluid flow can be used for simulating sound propagation. In this article application of the LBM to sound propagation is illustrated for various cases: free-fi

  8. Gun utopias? Firearm access and ownership in Israel and Switzerland. (United States)

    Rosenbaum, Janet E


    The 2011 attempted assassination of a US representative renewed the national gun control debate. Gun advocates claim mass-casualty events are mitigated and deterred with three policies: (a) permissive gun laws, (b) widespread gun ownership, (c) and encouragement of armed civilians who can intercept shooters. They cite Switzerland and Israel as exemplars. We evaluate these claims with analysis of International Crime Victimization Survey (ICVS) data and translation of laws and original source material. Swiss and Israeli laws limit firearm ownership and require permit renewal one to four times annually. ICVS analysis finds the United States has more firearms per capita and per household than either country. Switzerland and Israel curtail off-duty soldiers' firearm access to prevent firearm deaths. Suicide among soldiers decreased by 40 per cent after the Israeli army's 2006 reforms. Compared with the United States, Switzerland and Israel have lower gun ownership and stricter gun laws, and their policies discourage personal gun ownership.

  9. NASA Space Sounds API (United States)

    National Aeronautics and Space Administration — NASA has released a series of space sounds via sound cloud. We have abstracted away some of the hassle in accessing these sounds, so that developers can play with...

  10. Sound Ecologies

    Directory of Open Access Journals (Sweden)

    Michelle Duffy


    Full Text Available Discussions about what constitutes ‘the rural’ invariably focus on notions of spatial location – of inhabiting spaces apart from that of the metropolitan. Deeply embedded in our images of what it means to be Australian, nonetheless our intellectual framing of ‘the rural’ as something outback and beyond has significant implications for our relations with these spaces. The relatively recent phenomenon of sea- and tree-changes has struck many unawares, and not simply because a good latté is so hard to find. Although a frivolous remark, such an apparent lack does shift our focus to a bodily scale of the rural; how is rural place re/made through our experiences of it? This article originates out of on-going research that explores the practice of listening and sound and the ways in which the body can draw attention to the intuitive, emotional, and psychoanalytical processes of subjectivity and place-making. Drawing on Nigel Thrift’s concept of an ecology of place, I suggest that contemporary heightened concerns with regards to loss and lack in rural Australia has led to a nascent emotional economy – one in which individual and intimate connections to the rural require a rethinking of how we live community and belonging. In such a terrain, what does it mean to be rural?

  11. Sound localization in the alligator. (United States)

    Bierman, Hilary S; Carr, Catherine E


    In early tetrapods, it is assumed that the tympana were acoustically coupled through the pharynx and therefore inherently directional, acting as pressure difference receivers. The later closure of the middle ear cavity in turtles, archosaurs, and mammals is a derived condition, and would have changed the ear by decoupling the tympana. Isolation of the middle ears would then have led to selection for structural and neural strategies to compute sound source localization in both archosaurs and mammalian ancestors. In the archosaurs (birds and crocodilians) the presence of air spaces in the skull provided connections between the ears that have been exploited to improve directional hearing, while neural circuits mediating sound localization are well developed. In this review, we will focus primarily on directional hearing in crocodilians, where vocalization and sound localization are thought to be ecologically important, and indicate important issues still awaiting resolution.

  12. Analytic Formulation for the Sound Absorption of a Panel Absorber under the Effects of Microperforation, Air Pumping, Linear Vibration and Nonlinear Vibration

    Directory of Open Access Journals (Sweden)

    Y. Y. Lee


    Full Text Available This study includes the first work about the absorption of a panel absorber under the effects of microperforation, air pumping, and linear and nonlinear vibrations. In practice, thin perforated panel absorber is backed by a flexible wall to enhance the acoustic performance within the room. The panel is easily excited to vibrate nonlinearly and the wall can vibrate linearly. However, the assumptions of linear panel vibration and no wall vibration are adopted in many research works. The development of the absorption formula is based on the classical approach and the electroacoustic analogy, in which the impedances of microperforation, air pumping, and linear and nonlinear vibrations are in parallel and connected to that of the air cavity in series. Unlike those finite element, numerical integration, and multiscale solution methods and so forth, the analytic formula to calculate the absorption of a panel absorber does not require heavy computation effort and is suitable for engineering calculation purpose. The theoretical result obtained from the proposed method shows reasonable agreement with that from a previous numerical integration method. It can be concluded that the overall absorption bandwidth of a panel absorber with an appropriate configuration can be optimized and widened by making use of the positive effects of microperforation, air pumping, and panel vibration.

  13. Seismic data collection from water gun and industrial background sources in the Chicago Sanitary and Ship Canal area, Illinois, 2011 (United States)

    Morrow, William S.; Carpenter, Phillip J.; Adams, Ryan F.


    The water gun is a tool adapted from deep marine geophysical surveys that is being evaluated for use as an acoustic fish deterrent to control the movement of invasive marine species. The water gun creates a seismic signal by using a compressed air discharge to move a piston rapidly within the water, resulting in an implosion. This energy pulse may be able to modify fish behavior or destroy marine life, such as the Asian carp, at some distance. The effects of this energy pulse on structures in the Chicago Sanitary and Ship Canal (CSSC), such as canal walls, shore lines, and lock structures, are not known. The potential effects of the use of a water gun on structures was identified as a concern in the CSSC and was assessed relative to existing background sources during this study. During September 2011, two water guns with piston sizes of 80 and 343 cubic inches, respectively, were tested in the CSSC at varying pressures and distances from a canal wall consisting of dolomite and dolomite setblock. Seismic data were collected during these water gun firings using geophones on land, in boreholes, and at the canal wall interface. Data were collected at varying depths in the canal water using hydrophones. Seismic data were also collected during the occurrences of barge traffic, railroad traffic located near the electric fish barrier in Lemont, and coal-loading operations at a coal power plant near the electric fish barrier. In general, energy produced by barge and railroad sources was less than energy created by the water gun. Energy levels produced by coal-loading operations at least 200 feet from geophones were approximately four times lower than energy levels measured during water gun operations.

  14. In vitro fatigue behaviour of vacuum plasma and detonation gun sprayed hydroxyapatite coatings. (United States)

    Gledhill, H C; Turner, I G; Doyle, C


    The fatigue behaviour of vacuum plasma sprayed (VPS) and detonation gun sprayed (DGUN) hydroxyapatite coatings on titanium substrates has been compared in air and in buffered Ringer's solution. There was an increase in the surface microcracking and bulk porosity of both types of coating tested in air. After 1 million cycles in Ringer's solution the VPS coatings had completely delaminated from their substrates. In contrast the DGUN coatings retained their integrity when tested up to 10 million cycles but were beginning to show signs of delamination at the interface.

  15. Hall effect degradation of rail gun performance (United States)

    Witalis, E. A.; Gunnarsson, Patrik


    The paper discusses the Hall effect and shows it to be significant in the low-density and high-field trailing part of a plasma armature. Without the Hall effect a simple armature model is derived. It exhibits properties expected from classical MHD theory and shows that the purely relativistic electric charge buildup on the rails is a fundamental gun property, leading to V(breech) = 1.5 V(muzzle). The mathematics involved in accounting for Hall effect phenomena is described. These are of two types: the Hall-skewing of the armature current and the superimposed plasma flow rotation. For decreasing gun current the two effects efficiently combine to eject armature plasma rearwards, thus creating conditions for arc separation and parasitic arcs.

  16. High Impetus Cool Burning Gun Propellants

    Directory of Open Access Journals (Sweden)

    R.S. Dames


    Full Text Available This study explores the possibility of reducing the flame temperature (Tf without decrease in impetus of RDX-NC matrix-based high energy gun propellants by partial replacement of RDX with triaminoguanidine nitrate (TAGN. Compositions containing TAGN as an energetic oxidiser with varying percentage of RDX have been formulated. Glycidyl azide polymer was incorporated as an energetic plasticiser to achieve the higher level of impetus. Performance in terms of ballistic parameters (theoretical/experimental sensitivity, thermal characteristics, stability and mechanical properties was evaluated and compared with the basic composition containing RDX as a single oxidiser. Experimental data indicates that the partial replacement of RDX by TAGN in gun propellant compositions decreases Tf significantly with only marginal decrease in impetus. "

  17. Electrical parameters of projectile stun guns. (United States)

    McDaniel, Wayne C; Benwell, Andrew; Kovaleski, Scott


    Projectile stun guns have been developed as less-lethal devices that law enforcement officers can use to control potentially violent subjects, as an alternative to using firearms. These devices apply high voltage, low amperage, pulsatile electric shocks to the subject, which causes involuntary skeletal muscle contraction and renders the subject unable to further resist. In field use of these devices, the electric shock is often applied to the thorax, which raises the issue of cardiac safety of these devices. An important determinant of the cardiac safety of these devices is their electrical output. Here the outputs of three commercially available projectile stun guns were evaluated with a resistive load and in a human-sized animal model (a 72 kg pig).

  18. Field Test Kit for Gun Residue Detection

    Energy Technology Data Exchange (ETDEWEB)



    One of the major needs of the law enforcement field is a product that quickly, accurately, and inexpensively identifies whether a person has recently fired a gun--even if the suspect has attempted to wash the traces of gunpowder off. The Field Test Kit for Gunshot Residue Identification based on Sandia National Laboratories technology works with a wide variety of handguns and other weaponry using gunpowder. There are several organic chemicals in small arms propellants such as nitrocellulose, nitroglycerine, dinitrotoluene, and nitrites left behind after the firing of a gun that result from the incomplete combustion of the gunpowder. Sandia has developed a colorimetric shooter identification kit for in situ detection of gunshot residue (GSR) from a suspect. The test kit is the first of its kind and is small, inexpensive, and easily transported by individual law enforcement personnel requiring minimal training for effective use. It will provide immediate information identifying gunshot residue.

  19. Cerebral damage caused by nail gun injury

    DEFF Research Database (Denmark)

    Andersen, Chris


    . The forensic examination showed lesions of intracranial surgery and minor bruises on the arms. No sign of defense injuries was found. There were no signs of malfunction of the nail gun-wielding robot. On the side of the machine, there were a handheld nail gun and the police investigated the case as a possible......-inflicted or a criminal act. Case presentation A 43-year-old male worker was brought to the emergency department after his coworkers had found him on the floor in the cafeteria at work. He was admitted to the hospital due to a possible apoplexy. The CT scan revealed a nail in his skull and acute surgery was performed...

  20. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance. (United States)


    ... 46 Shipping 6 2010-10-01 2010-10-01 false Equipment for shoulder gun type line-throwing appliance... Appliance, Shoulder Gun Type (and Equipment) § 160.031-4 Equipment for shoulder gun type line-throwing... the gun. The line canister shall be secured by clamps or brackets below the barrel of the gun. (c)...

  1. Hardware Requirements for Helicopter Air-to-Air Weapons in the 1980s (United States)


    flexibility to be used against both air- to-air and air-to-surface targets. The XM14c ( Figura 0) is a light weight 30-mm automatic gun capable of a... Publica - tion, 14 November 1977. 7!-L . ... . . . .. .. .. lobj U.S. Army Command and General Staff College, Profession of Am Course 9000 (PY A74-73

  2. Statistics tolerances on built up guns.

    Directory of Open Access Journals (Sweden)

    J. P. Sirpal


    Full Text Available The strength of built up guns depends on the shrinkages allowed between cylinders and therefore for a given strength, the assembly is either selective or the nominal sizes are so chosen as to give the required shrinkage for a worst combination, it can be seen from the analysis that with little disadvantage tolerances can be greatly increased assuming random assemblies of parts whose sizes follow a normal pattern. This can bring down production costs considerably.

  3. Media violence, gun control, and public policy. (United States)

    Zuckerman, D M


    Public concern with the national level of violence is discussed, and the complexity of the issue delineated. Research findings in two key areas of the topic, media violence and availability of firearms, are examined, as is their applicability to public policy efforts and recommendations for the prevention of violence. An approach that combines efforts to counteract media violence with those aimed at effective gun control is outlined in terms of bringing about changes in attitudes toward violence and firearm possession.

  4. The Sound of Science (United States)

    Merwade, Venkatesh; Eichinger, David; Harriger, Bradley; Doherty, Erin; Habben, Ryan


    While the science of sound can be taught by explaining the concept of sound waves and vibrations, the authors of this article focused their efforts on creating a more engaging way to teach the science of sound--through engineering design. In this article they share the experience of teaching sound to third graders through an engineering challenge…

  5. Sound reproduction system

    NARCIS (Netherlands)

    Boone, M.M.; De Vries, D.; Horbach, U.


    Arrangement of a sound reproduction system (1), including at least one input (2), a sound field generator (4), a loudspeaker panel (10); the at least one input (2) connected to the sound filed generator (4), and the sound filed (4) connected to the loudspeaker panel (10); the at least one input (2)

  6. Beam-Based Procedures for RF Guns

    CERN Document Server

    Krasilnikov, Mikhail; Grabosch, H J; Hartrott, Michael; Hui Han, Jang; Miltchev, Velizar; Oppelt, Anne; Petrosyan, Bagrat; Staykov, Lazar; Stephan, Frank


    A wide range of rf photo injector parameters has to be optimized in order to achieve an electron source performance as required for linac based high gain FELs. Some of the machine parameters can not be precisely controlled by direct measurements, whereas the tolerance on them is extremely tight. Therefore, this should be met with beam-based techniques. Procedures for beam-based alignment (BBA) of the laser on the photo cathode as well as solenoid alignment have been developed. They were applied at the Photo Injector Test facility at DESY Zeuthen (PITZ) and at the photo injector of the VUV-FEL at DESY Hamburg. A field balance of the accelerating mode in the 1 ½ cell gun cavity is one of the key beam dynamics issues of the rf gun. Since no direct field measurement in the half and full cell of the cavity is available for the PITZ gun, a beam-based technique to determine the field balance has been proposed. A beam-based rf phase monitoring procedure has been developed as well.

  7. Overview of Plasma Guns for PLX (United States)

    Witherspoon, F. Douglas; Bomgardner, Richard; Case, Andrew; Messer, Sarah; Brockington, Samuel; Wu, Linchun; Elton, Raymond; Hsu, Scott; Cassibry, Jason; Gilmore, Mark


    Plasma guns are being developed for use on the Plasma Liner Experiment (PLX) located at LANL. The collapsing plasma liner will be formed via merging of 30-60 dense, high Mach number plasma jets (n˜10^16-17 cm-3, M˜10--35, v˜50--70 km/s, rjet˜5 cm) in a spherically convergent geometry. Small parallel-plate railguns are being developed for this purpose. Each gun will operate at ˜300-600 kA peak current, and launch up to ˜8000 μg of high-Z plasma (Ar, Xe) using a ˜50 kJ pfn. We are now successfully operating with very fast gas valve injection of Ar, and have already achieved good performance of 1200 μg at 42 km/s, and 4000 μg at 20-25 km/s at low current. Work is underway to increase both the mass and velocity using higher current. We describe experimental development of the minirailguns and their present and projected performance. We also discuss options for modest size coaxial guns that might achieve the same performance and provide additional control of the plasmoid structure.

  8. Microcracks repairing technique for gun barrel

    Institute of Scientific and Technical Information of China (English)

    YU Xu-dong; WU Bin; SU Bing; WANG Cheng-tao


    When a gun fires the diffusion of chemical species from the propellant gas, such as CO, CO2, H2, H2O and N2, into the hot surface through the microcracks forms reaction products and speeds up the erosion process.Therefore, crack repairing and healing can be a possible measure for protecting against erosion of gun bore. The present study develops a novel nanocomposite with the size of 30 - 150 nm to repair and heal the microcracks so that the propellant gas can be prevented from reacting with the steel. Sample of gun steel 40CrNiMoV plate (10 mm× 10 mm × 2 mm) is prepared and a fishtail crack is generated through a repeated plastic deformation process. The crackrepairing results show that the fishtail crack become shorter and narrower. A new phase is formed, which is found to have the elements, such as Ca, La, from the raw materials of nanocomposite by energy spectrum analysis.

  9. The HART I augmented electric gun facility

    Energy Technology Data Exchange (ETDEWEB)

    Fikse, D.A.; Ciesar, J.A.; Wehrli, H.A.; Rimersma, H.; Docherty, E.F.; Pipich, C.W. (Westinghouse Science and Technology Center, Pittsburgh, PA (US))


    This paper reports on an augmented electric gun system that has been commissioned. This system, called HART I (Hypervelocity Augmented Railgun Test), is built around a double augmented rail arrangement with a 1.27-cm square bore. It is powered by the SUVAC II 5.6-MJ distributed capacitor power supply. This arrangement allows operation in a simple, series augmented, or transaugmented gun system configuration. The objective of this facility is to perform materials research augmentation studies, and armature development in the 10-km/s regime. Armature masses of 2 to 4 g will be accelerated in a 4-m long barrel. Baseline bore materials will begin with conventional G9/GlidCop systems and then move into pyrolytic boron nitride/refractory materials. Hybrids, plasma, and ablation stabilized armature systems are planned. The gun system is instrumented with plasma and rail B-dot probes for inbore velocity measurements. In addition, breech and muzzle voltages, currents, and external velocities are measured. The HART I system is currently performing hypervelocity experiments to verify the augmentation models.

  10. Diagnostics Beamline for the SRF Gun Project

    Energy Technology Data Exchange (ETDEWEB)

    T. Kamps; V. Durr; K. Goldammer; D. Kramer; P. Kuske; J. Kuszynski; D. Lipka; F. Marhauser; T. Quast; D. Richter; U. Lehnert; P. Michel; J. Teichert; P. Evtushenko; I. Will


    A superconducting radio-frequency photo electron injector (SRF gun) is currently under construction by a collaboration of BESSY, DESY, FZR and MBI. The project aims at the design and setup of a CW SRF gun including a diagnostics beamline for the ELBE FEL and to address R&D issues on low emittance injectors for future light sources such as the BESSY FEL. Of critical importance for the injector performance is the control of the electron beam parameters. For this reason a compact diagnostics beamline is under development serving a multitude of operation settings ranging from low-charge (77pC), low-emittance (1 mm mrad) mode to high-charge (2.5nC) operation of the gun. For these operation modes beam dynamics simulations are resulting in boundary conditions for the beam instrumentation. Proven and mature technology is projected wherever possible, for example for current and beam position monitoring. The layout of the beam profile and emittance measurement systems is described. For the bunch length, which varies between 5 ps and 50 ps, two schemes using electro-optical sampling and Cherenkov radiation are detailed. The beam energy and energy spread is measured with a 180-degree spectrometer.

  11. Vaccination Using Gene-Gun Technology. (United States)

    Bergmann-Leitner, Elke S; Leitner, Wolfgang W


    DNA vaccines against infection with Plasmodium have been highly successful in rodent models of malaria and have shown promise in the very limited number of clinical trials conducted so far. The vaccine platform is highly attractive for numerous reasons, such as low cost and a very favorable safety profile. Gene gun delivery of DNA plasmids drastically reduces the vaccine dose and does not only have the potential to make vaccines more accessible and affordable, but also simplifies (a) the testing of novel antigens as vaccine candidates, (b) the testing of antigen combinations, and (c) the co-delivery of antigens with molecular adjuvants such as cytokines or costimulatory molecules. Described in this chapter are the preparation of the inoculum (i.e., DNA plasmids attached to gold particles, coating to the inside of plastic tubing also referred to as gene gun "bullets" or cartridges), the gene gun vaccination procedure, and the challenge of mice with Plasmodium berghei parasites to test the efficacy of the experimental vaccine.

  12. Diagnostics Beamline for the SRF Gun Project

    CERN Document Server

    Kamps, T; Goldammer, K; Krämer, Dietrich; Kuske, P; Kuszynski, J; Lipka, D; Marhauser, F; Quast, T; Richter, R


    A superconducting rf photo electron injector (SRF gun) is currently under construction by a collaboration between BESSY, DESY, FZR and MBI. The project aims at the design and setup of an CW SRF gun including a diagnostics beamline for the ELBE FEL and to address R&D issues on low emittance injectors for future light sources such as the BESSY FEL. Of critical importance for the injector performance is the control of the electron beam parameters. For this reason a compact diagnostics beamline is under development serving a multitude of operation settings ranging from low-charge (77pC), low-emittance (1 pi mm mrad) mode to high-charge (2.5nC) operation of the gun. For these operation modes beam dynamics simulations are resulting in boundary conditions for the beam instrumentation. Proven and mature technology is projected wherever possible, for example for current and beam position monitoring. The layout of the beam profile and emittance measurement systems is described. For the bunch length, which varies be...

  13. A projectile for a rectangular barreled rail gun


    Juanche, Francisco M.


    The Physics Department at the Naval Postgraduate School is developing a concept to overcome the problems that keep present rail guns from being practical weapons. The rails must be replaced often if the rail gun operation is to be continuous. Replacing the rails in present rail gun configurations is time consuming. The Physics Department's design concept uses a rectangular barrel as part of the solution to the problem of replacing the rails. The projectile will require flat surfaces to mainta...

  14. Structural Optimization of Machine Gun Based on Dynamic Stability Concept

    Institute of Scientific and Technical Information of China (English)

    LI Yong-jian; WANG Rui-lin; ZHANG Ben-jun


    Improving the firing accuracy is a final goal of structural optimization of machine guns. The main factors which affect the dispersion accuracy of machine gun are analyzed. Based on the concept of dynamic stability, a structural optimization model is built up, and the sensitivity of dispersion accuracy to design variables is analyzed. The optimization results of a type of machine gun show that the method is valid, feasible, and can be used as a guide to the structural optimization of other automatic weapons.

  15. Pneumatic capillary gun for ballistic delivery of microparticles

    CERN Document Server

    Rinberg, D; Groisman, A; Rinberg, Dmitry; Simonnet, Claire; Groisman, Alex


    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.

  16. Sound absorption and reflection with coupled tubes



    This paper describes a special sound absorbing technique with an accompanying efficient numerical design tool. As a basis pressure waves in a single narrow tube or pore are considered. In such a tube the viscosity and the thermal conductivity of the air, or any other fluid, can have a significant effect on the wave propagation. An important aspect is that due to the viscothermal wave propagation sound energy is being dissipated. This has been applied to configurations consisting of a manifold...

  17. Behavioral Indicators of Legal and Illegal Gun Carrying (United States)


    access to the gun by simply reaching under the shirt or lifting up the shirt. Depending on the size of the gun and how it is secured, it will sometimes...person runs, the more the gun will wiggle. Depending upon the type of clothes a person is wearing and the size of the gun, there is likely to be a...the mass and size of the weapon and how it is carried. Second, those related to the situational and environmental awareness of the individual

  18. A flow cryostat for cooling of eight independent pipe guns

    DEFF Research Database (Denmark)

    Sørensen, H.; Hansen, J.E.; Sass, B.


    A flow cryostat allowing independent cooling of eight pipe guns in a multishot deuterium pellet injector is described. The pipe guns are placed symmetrically around the flow cryostat and with a liquid helium consumption of 4-5 l/h the cooling is sufficient for simultaneous formation of eight...... pellets at 8-9 K with a diameter of 2.1 mm containing up to 8 x 10(20) atoms/pellet. The thermal interaction between the eight pipe guns is sufficiently low to allow successive firing of the guns with time intervals of up to 1 s....

  19. Simulation of Sound Waves Using the Lattice Boltzmann Method for Fluid Flow: Benchmark Cases for Outdoor Sound Propagation.

    Directory of Open Access Journals (Sweden)

    Erik M Salomons

    Full Text Available Propagation of sound waves in air can be considered as a special case of fluid dynamics. Consequently, the lattice Boltzmann method (LBM for fluid flow can be used for simulating sound propagation. In this article application of the LBM to sound propagation is illustrated for various cases: free-field propagation, propagation over porous and non-porous ground, propagation over a noise barrier, and propagation in an atmosphere with wind. LBM results are compared with solutions of the equations of acoustics. It is found that the LBM works well for sound waves, but dissipation of sound waves with the LBM is generally much larger than real dissipation of sound waves in air. To circumvent this problem it is proposed here to use the LBM for assessing the excess sound level, i.e. the difference between the sound level and the free-field sound level. The effect of dissipation on the excess sound level is much smaller than the effect on the sound level, so the LBM can be used to estimate the excess sound level for a non-dissipative atmosphere, which is a useful quantity in atmospheric acoustics. To reduce dissipation in an LBM simulation two approaches are considered: i reduction of the kinematic viscosity and ii reduction of the lattice spacing.

  20. Simulation of Sound Waves Using the Lattice Boltzmann Method for Fluid Flow: Benchmark Cases for Outdoor Sound Propagation. (United States)

    Salomons, Erik M; Lohman, Walter J A; Zhou, Han


    Propagation of sound waves in air can be considered as a special case of fluid dynamics. Consequently, the lattice Boltzmann method (LBM) for fluid flow can be used for simulating sound propagation. In this article application of the LBM to sound propagation is illustrated for various cases: free-field propagation, propagation over porous and non-porous ground, propagation over a noise barrier, and propagation in an atmosphere with wind. LBM results are compared with solutions of the equations of acoustics. It is found that the LBM works well for sound waves, but dissipation of sound waves with the LBM is generally much larger than real dissipation of sound waves in air. To circumvent this problem it is proposed here to use the LBM for assessing the excess sound level, i.e. the difference between the sound level and the free-field sound level. The effect of dissipation on the excess sound level is much smaller than the effect on the sound level, so the LBM can be used to estimate the excess sound level for a non-dissipative atmosphere, which is a useful quantity in atmospheric acoustics. To reduce dissipation in an LBM simulation two approaches are considered: i) reduction of the kinematic viscosity and ii) reduction of the lattice spacing.

  1. Action Alters Object Identification: Wielding a Gun Increases the Bias to See Guns (United States)

    Witt, Jessica K.; Brockmole, James R.


    Stereotypes, expectations, and emotions influence an observer's ability to detect and categorize objects as guns. In light of recent work in action-perception interactions, however, there is another unexplored factor that may be critical: The action choices available to the perceiver. In five experiments, participants determined whether another…

  2. Cyclic Gun--Human Evolution: Soldiers, Guns, Machine Logic, and the Future (United States)

    Blackmore, Tim


    Guns, slug-throwing weapons, have evolved as humans have increased their grasp of the mechanical arts. In the near future, however, it seems likely that soldiers' rifles operating at punishing cyclic rates of fire face the limits of physics and materials science--heat and speed will cost accuracy and distance. This article considers not only the…

  3. Synthesized size-sound sound symbolism

    NARCIS (Netherlands)

    Lockwood, G.F.; Hagoort, P.; Dingemanse, M.


    Studies of sound symbolism have shown that people can associate sound and meaning in consistent ways when presented with maximally contrastive stimulus pairs of nonwords such as bouba/kiki (rounded/sharp) or mil/mal (small/big). Recent work has shown the effect extends to antonymic words from natura

  4. Facing sound – voicing art

    Directory of Open Access Journals (Sweden)

    Ansa Lønstrup


    Full Text Available This article is based on examples of contemporary audiovisual art with a primary focus on the Tony Oursler solo exhibition Face to Face in Aarhus Art Museum ARoS, 2012. My investigation involves a combination of qualitative interviews with visitors, observations of the audience’s interactions with the exhibition and the artwork in the museum space, and short analyses of individual works of art based on reception aesthetics, phenomenology, and newer writings on sound, voice and listening. The focus of the investigation is the quality and possible perspectives of the interaction with audiovisual works of art, articulating and sounding out their own ‘voices’. This methodological combination has been chosen to transgress the dichotomy between the aesthetic or hermeneutic artwork ‘text’ analysis and cultural theory, which focuses on the context understood as the framing, the cultural acts and agendas around the aesthetic ‘text’. The article will include experiences with another exhibition, David Lynch: The Air is on Fire (Fondation Cartier pour l’art contemporain, Paris, 2007 and Kunstforeningen Gl. Strand, Copenhagen, 2010- 2011. The two exhibitions are fundamentally different in their integration of sound. My field of interest concerns the exploration of sound as artistic material in audiovisual combinations and those audiovisual works of art that might cause a change in the participatory strategy of the art museum towards the audience.

  5. Early sound symbolism for vowel sounds. (United States)

    Spector, Ferrinne; Maurer, Daphne


    Children and adults consistently match some words (e.g., kiki) to jagged shapes and other words (e.g., bouba) to rounded shapes, providing evidence for non-arbitrary sound-shape mapping. In this study, we investigated the influence of vowels on sound-shape matching in toddlers, using four contrasting pairs of nonsense words differing in vowel sound (/i/ as in feet vs. /o/ as in boat) and four rounded-jagged shape pairs. Crucially, we used reduplicated syllables (e.g., kiki vs. koko) rather than confounding vowel sound with consonant context and syllable variability (e.g., kiki vs. bouba). Toddlers consistently matched words with /o/ to rounded shapes and words with /i/ to jagged shapes (p < 0.01). The results suggest that there may be naturally biased correspondences between vowel sound and shape.

  6. Gas powered fluid gun with recoil mitigation (United States)

    Grubelich, Mark C; Yonas, Gerold


    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  7. Characterisation of plasma in a rail gun (United States)

    Ray, P. K.


    The mechanism of plasma and projectile acceleration in a DC rail gun is described from a microscopic point of view through the establishment of the Hall field. The plasma conductivity is shown to be a tensor, indicating that there is a small component of current parallel to the direction of acceleration. The plasma characteristics are evaluated in the experiment of Bauer et. al., as a function of plasma mass through a simple fluid mechanical analysis of the plasma. By equating the energy dissipatated in the plasma with the radiation heat loss, the properties of the plasma are determined.

  8. Electromagnetic Gun Circuit Analysis Code (EGCAC) (United States)

    Rolader, Glenn E.; Thornhill, Lindsey D.; Batteh, Jad H.; Scanlon, James J., III


    This paper describes a system engineering code that simulates the performance of a railgun/power supply system. The code, named EGCAC (Electromagnetic Gun Circuit Analysis Code), accounts for many performance degrading effects including viscous drag on the armature, viscous drag on the gas being pushed in front of the projectile, entrained gas that must be accelerated in front of the projectile, time-dependent rail resistance, armature resistance, system resistance, and ablation drag. EGCAC has been utilized to predict railgun performance up to a velocity of approximately 4 km/s for experiments at several laboratories. In this paper, the theory of EGCAC is described, and sample calculations are presented.

  9. Gas powered fluid gun with recoil mitigation (United States)

    Grubelich, Mark C.; Yonas, Gerold


    A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.

  10. Smart gun technology requirements preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D.R.; Brandt, D.J.; Tweet, K.D.


    Goal of the Smart Gun Technology project is to eliminate the capability of an unauthorized user from firing a law enforcement officer`s firearm by implementing user-recognizing-and-authorizing surety technologies. This project is funded by the National Institute of Justice. This document reports the projects first objective: to find and document the requirements for a user-recognizing-and-authorizing firearm technology that law enforcement officers will value. This report details the problem of firearm takeaways in law enforcement, the methodology used to develop the law enforcement officers` requirements, and the requirements themselves.

  11. Analysis of environmental sounds (United States)

    Lee, Keansub

    Environmental sound archives - casual recordings of people's daily life - are easily collected by MPS players or camcorders with low cost and high reliability, and shared in the web-sites. There are two kinds of user generated recordings we would like to be able to handle in this thesis: Continuous long-duration personal audio and Soundtracks of short consumer video clips. These environmental recordings contain a lot of useful information (semantic concepts) related with activity, location, occasion and content. As a consequence, the environment archives present many new opportunities for the automatic extraction of information that can be used in intelligent browsing systems. This thesis proposes systems for detecting these interesting concepts on a collection of these real-world recordings. The first system is to segment and label personal audio archives - continuous recordings of an individual's everyday experiences - into 'episodes' (relatively consistent acoustic situations lasting a few minutes or more) using the Bayesian Information Criterion and spectral clustering. The second system is for identifying regions of speech or music in the kinds of energetic and highly-variable noise present in this real-world sound. Motivated by psychoacoustic evidence that pitch is crucial in the perception and organization of sound, we develop a noise-robust pitch detection algorithm to locate speech or music-like regions. To avoid false alarms resulting from background noise with strong periodic components (such as air-conditioning), a new scheme is added in order to suppress these noises in the domain of autocorrelogram. In addition, the third system is to automatically detect a large set of interesting semantic concepts; which we chose for being both informative and useful to users, as well as being technically feasible. These 25 concepts are associated with people's activities, locations, occasions, objects, scenes and sounds, and are based on a large collection of

  12. Gun possession among American youth: a discovery-based approach to understand gun violence.

    Directory of Open Access Journals (Sweden)

    Kelly V Ruggles

    Full Text Available OBJECTIVE: To apply discovery-based computational methods to nationally representative data from the Centers for Disease Control and Preventions' Youth Risk Behavior Surveillance System to better understand and visualize the behavioral factors associated with gun possession among adolescent youth. RESULTS: Our study uncovered the multidimensional nature of gun possession across nearly five million unique data points over a ten year period (2001-2011. Specifically, we automated odds ratio calculations for 55 risk behaviors to assemble a comprehensive table of associations for every behavior combination. Downstream analyses included the hierarchical clustering of risk behaviors based on their association "fingerprint" to 1 visualize and assess which behaviors frequently co-occur and 2 evaluate which risk behaviors are consistently found to be associated with gun possession. From these analyses, we identified more than 40 behavioral factors, including heroin use, using snuff on school property, having been injured in a fight, and having been a victim of sexual violence, that have and continue to be strongly associated with gun possession. Additionally, we identified six behavioral clusters based on association similarities: 1 physical activity and nutrition; 2 disordered eating, suicide and sexual violence; 3 weapon carrying and physical safety; 4 alcohol, marijuana and cigarette use; 5 drug use on school property and 6 overall drug use. CONCLUSIONS: Use of computational methodologies identified multiple risk behaviors, beyond more commonly discussed indicators of poor mental health, that are associated with gun possession among youth. Implications for prevention efforts and future interdisciplinary work applying computational methods to behavioral science data are described.

  13. Modelling Hyperboloid Sound Scattering

    DEFF Research Database (Denmark)

    Burry, Jane; Davis, Daniel; Peters, Brady;


    The Responsive Acoustic Surfaces workshop project described here sought new understandings about the interaction between geometry and sound in the arena of sound scattering. This paper reports on the challenges associated with modelling, simulating, fabricating and measuring this phenomenon using...

  14. Making fictions sound real

    DEFF Research Database (Denmark)

    Langkjær, Birger


    of sounds. Apart from an account of the kinds of sounds that typically appear in a specific genre, a genre analysis of sound may also benefit from a functionalist approach that focuses on how sounds can make both realist and non-realist aspects of genres sound real to audiences.......This article examines the role that sound plays in making fictions perceptually real to film audiences, whether these fictions are realist or non-realist in content and narrative form. I will argue that some aspects of film sound practices and the kind of experiences they trigger are related...... to basic rules of human perception, whereas others are more properly explained in relation to how aesthetic devices, including sound, are used to characterise the fiction and thereby make it perceptually real to its audience. Finally, I will argue that not all genres can be defined by a simple taxonomy...

  15. Sound wave transmission (image) (United States)

    When sounds waves reach the ear, they are translated into nerve impulses. These impulses then travel to the brain where they are interpreted by the brain as sound. The hearing mechanisms within the inner ear, can ...

  16. A 3 GHz photoelectron gun for high beam intensity

    CERN Document Server

    Bossart, Rudolf; Dehler, M; Godot, J C


    For the Compact Linear Collider Test Facility (CTF) at CERN a new rf gun with a laser driven photocathode is under construction. The new rf gun will replace the present 11/2 cell gun and will consist of 21/2 cells accelerating the beam to a momentum of 7.0 MeV/c with an electric field strength of 100 MV/m. The strong space-charge forces at low beam energy caused by the high charge density of the electron bunches are contained by radial and longitudinal rf focusing in the gun. The rf gun under construction has been optimized by MAFIA beam simulations for an injector assembly comprising a second accelerating rf structure and an intermediate solenoid magnet correcting the beam divergence of the 21/2 cell gun. The beam loading of the rf gun, by a train of 48 bunches with 21 nC charge each, causes a strong energy decay accompanied by an increase of the flight time for the bunches with lower energy. These effects can be corrected by slightly shifting the acceleration frequency of the gun. The experimental results...

  17. Gunning Mix or Converter and Electric Arc Furnace in China

    Institute of Scientific and Technical Information of China (English)

    LIUJie-hua; ZHANGYong-fang


    The increase of steel output by converter and electric are furnace has imposed a critical demand in quality and quantity on gunning mix in functioning a longer life of those de-vices linings.The paoer describes the consump-tion of gunning mix for converter and EAF and its recent development in variety and quality in China.

  18. Everyday Engineering: What Makes a Squirt Gun Squirt? (United States)

    Moyer, Richard; Everett, Susan


    You may not think of engineering and squirt guns in the same sentence. However, like many examples of engineering design, the squirt gun pump mechanism is uncomplicated, yet elegant, and very inexpensive to manufacture. The design is widely used because of its simplicity and low cost. With only a few moving parts, it is able to deliver a stream of…

  19. NASCAP simulation of laboratory charging tests using multiple electron guns (United States)

    Mandell, M. J.; Katz, I.; Parks, D. E.


    NASCAP calculations have been performed simulating exposure of a spacecraft-like model to multiple electron guns. The results agree well with experiment. It is found that magnetic field effects are fairly small, but substantial differential charging can result from electron gun placement. Conditions for surface flashover are readily achieved.

  20. Guns and Fear: A One-Way Street? (United States)

    Hauser, Will; Kleck, Gary


    Surveys show that more than one half of gun owners report owning their firearm for self-protection. Although research has examined the effect of fear of crime on gun ownership, the issue of reciprocity and temporal order has been largely ignored. Furthermore, the effect of firearm acquisition and relinquishment on fear has not been evaluated…

  1. Taking Aim at Gun Violence: Rebuilding Community Education & Employment Pathways (United States)

    Bryant, Rhonda


    In January 2013, President Obama released a plan for protecting children and communities by reducing gun violence. This plan has generated serious debate from both sides of the issue. The ensuing conversations about how to solve the issue of gun violence have been volatile. The President's plan includes reforms to close loopholes on background…

  2. Preventing Clogging In A Vacuum Plasma Spray Gun (United States)

    Krotz, Phillip D.; Daniel, Ronald L., Jr.; Davis, William M.


    Modification of powder-injection ports enables lengthy, high-temperature deposition operations. Graphite inserts prevent clogging of ports through which copper powder injected into vacuum plasma spray (VPS) gun. Graphite liners eliminate need to spend production time refurbishing VPS gun, reducing cost of production and increasing productivity. Concept also applied to other material systems used for net-shape fabrication via VPS.

  3. Changing of ballistic parameters from aged gun propellants

    NARCIS (Netherlands)

    Klerk, W.P.C. de; Driel, C.A. van


    The various properties of an SB and a DB gun propellant were investigated before and after artificial ageing. It was found that the decrease of nitrocellulose (NC) molecular weight, due to ageing of gun propellants, leads to a decrease of the mechanical integrity of the propellant grains. The effect

  4. Normative Considerations in the Aftermath of Gun Violence in Schools (United States)

    Gereluk, Dianne T.; Donlevy, J. Kent; Thompson, Merlin B.


    Gun violence in American and Canadian schools is an ongoing tragedy that goes substantially beyond its roots in the interlocking emotional and behavioral issues of mental health and bullying. In light of the need for effective policy development, Dianne T. Gereluk, J. Kent Donlevy, and Merlin B. Thompson examine gun violence in schools from…

  5. Man & Sound Environment 2010.



    Proceedings to the conference "Man and Sound Environment 2010" arranged by The sound Envirnment Center at Lund university. Ulf Landström, Swedish Noise Research Network & Frans Mossberg The Sound Environment Centre at Lund university. CONTENTS: Preface – Symposium “Man and Sound Environment 2010” The prevalence of noise problems. Gunn Marit Aasvang, Norwegian Institute of Public Health, Department of Environmental Medicine, Nydalen, Oslo, Norway Effects of ...

  6. An Antropologist of Sound

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh


    PROFESSOR PORTRAIT: Sanne Krogh Groth met Holger Schulze, newly appointed professor in Musicology at the Department for Arts and Cultural Studies, University of Copenhagen, to a talk about anthropology of sound, sound studies, musical canons and ideology.......PROFESSOR PORTRAIT: Sanne Krogh Groth met Holger Schulze, newly appointed professor in Musicology at the Department for Arts and Cultural Studies, University of Copenhagen, to a talk about anthropology of sound, sound studies, musical canons and ideology....

  7. Broadcast sound technology

    CERN Document Server

    Talbot-Smith, Michael


    Broadcast Sound Technology provides an explanation of the underlying principles of modern audio technology. Organized into 21 chapters, the book first describes the basic sound; behavior of sound waves; aspects of hearing, harming, and charming the ear; room acoustics; reverberation; microphones; phantom power; loudspeakers; basic stereo; and monitoring of audio signal. Subsequent chapters explore the processing of audio signal, sockets, sound desks, and digital audio. Analogue and digital tape recording and reproduction, as well as noise reduction, are also explained.

  8. Air Cargo Security (United States)


    passenger and all-cargo aircraft. The air cargo system consists of a large, complex distribution network linking manufacturers and shippers to transportation to San Jose, California. His only luggage was a guitar case that concealed hammers, mallets, a knife, and a spear gun. At the...authorities and airplane manufacturers study methods to mitigate the effects of in-flight explosions.76 The FAA has had a active research program in blast

  9. Compact electron gun based on secondary emission through ionic bombardment. (United States)

    Diop, Babacar; Bonnet, Jean; Schmid, Thomas; Mohamed, Ajmal


    We present a new compact electron gun based on the secondary emission through ionic bombardment principle. The driving parameters to develop such a gun are to obtain a quite small electron gun for an in-flight instrument performing Electron Beam Fluorescence measurements (EBF) on board of a reentry vehicle in the upper atmosphere. These measurements are useful to characterize the gas flow around the vehicle in terms of gas chemical composition, temperatures and velocity of the flow which usually presents thermo-chemical non-equilibrium. Such an instrument can also be employed to characterize the upper atmosphere if placed on another carrier like a balloon. In ground facilities, it appears as a more practical tool to characterize flows in wind tunnel studies or as an alternative to complex electron guns in industrial processes requiring an electron beam. We describe in this paper the gun which has been developed as well as its different features which have been characterized in the laboratory.

  10. Cardiac stimulation with high voltage discharge from stun guns. (United States)

    Nanthakumar, Kumaraswamy; Massé, Stephane; Umapathy, Karthikeyan; Dorian, Paul; Sevaptsidis, Elias; Waxman, Menashe


    The ability of an electrical discharge to stimulate the heart depends on the duration of the pulse, the voltage and the current density that reaches the heart. Stun guns deliver very short electrical pulses with minimal amount of current at high voltages. We discuss external stimulation of the heart by high voltage discharges and review studies that have evaluated the potential of stun guns to stimulate cardiac muscle. Despite theoretical analyses and animal studies which suggest that stun guns cannot and do not affect the heart, 3 independent investigators have shown cardiac stimulation by stun guns. Additional research studies involving people are needed to resolve the conflicting theoretical and experimental findings and to aid in the design of stun guns that are unable to stimulate the heart.

  11. Guns, Mental Illness, and the Law: Introduction to This Issue. (United States)

    Swanson, Jeffrey W; Felthous, Alan R


    Firearm violence is a top-tier public health problem in the U.S., killing 33,563 and injuring an additional 81,396 people in 2012 (Centers for Disease Control and Prevention, CDC, ). Given constitutional protection and the cultural entrenchment of private gun ownership in the U.S., it is likely that guns will remain widely accessible--and largely unrestricted--for the foreseeable future. Therefore, most policies and laws intended to reduce firearm violence focus selectively on preventing "dangerous people" from having access to guns. That is a formidable challenge. How do we think productively about guns and mental illness in this context, and about the role of law in lessening the toll of gun violence?

  12. Status and running experience of the SRF gun at HZDR

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Rong; Arnold, Andre; Lu, Pengnan; Murcek, Petr; Teichert, Jochen; Vennekate, Hannes [Helmholtz Zentrum Dresden Rossendorf, 01328 Dresden (Germany)


    In order to achieve a high average current up to 1 mA with a low emittance of 1 mm mrad at 77 pC, an improved SRF gun has been installed and commissioned at HZDR since 2014. This new gun replaces the first 3.5-cell SRF gun at the superconducting linear accelerator ELBE which had been in operation since 2007. The new gun has been tested first with a Cu photocathode. The RF performance of the niobium cavity has been evaluated, the transverse and longitudinal beam parameters for low charge bunches have been measured, and the first beam has been guided into the ELBE beamline. The photocathode transfer system is also installed for the first high current beam test in 2015. In this contribution the status of the gun and the results of this first measurement period will be presented in detail.

  13. Status of the SRF Gun Operation at ELBE

    CERN Document Server

    Teichert, J; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, Ch; Schurig, R; Xiang, R; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I; Staufenbiel, F


    The superconducting RF photo-injector (SRF gun) at FZD is the first operating electron injector of its kind. The gun with a 3½-cell cavity and a frequency of 1.3 GHz produces an electron beam of 3 MeV with a maximum bunch charge of about 400 pC. Also the design values for the acceleration gradient could not be reached with the cavity which is in use at present, the SRF gun will improve the beam quality for ELBE users. In the winter shutdown of 2009/10 the beam line was installed which connects the SRF gun with the ELBE accelerator. The paper reports on the first tests and on the progress in applying the SRF gun for ELBE operation.

  14. American preferences for "smart" guns versus traditional weapons: Results from a nationwide survey. (United States)

    Wallace, Lacey Nicole


    This study examines Americans' preferences regarding smart guns. The study builds on prior research by including previously unexamined factors, specifically victimization and comfort sharing gun ownership status with a doctor. Further, this study examines differences in preference patterns among gun owners and non-owners. Data were obtained from a nationwide online survey with 524 respondents in February 2016. The study finds that, among non-owners, older respondents and those with pro-gun attitudes are less likely to prefer smart guns to traditional firearms. Among gun owners, those with moderate political views, those with a history of victimization, and those residing in the Northeast are all more likely to prefer smart guns. Males and those with pro-gun attitudes are less likely to prefer smart guns. Education, income, race, marital status, presence of children in the home, and comfort discussing gun ownership with a doctor had no significant association with smart gun preference. Practical implications of these findings are discussed.

  15. Researching home through sounds

    DEFF Research Database (Denmark)

    Winther, Ida Wentzel


    sounds via the sense of hearing; i.e., by listening. Furthermore, I examine some of the methodological challenges associated with listening to a space (as sound), interpreting what is heard and then representing the sounds in a text. I also discuss the types of knowledge that may be created through...... auditory and visual approaches....

  16. Sound visualization and manipulation

    CERN Document Server

    Kim, Yang-Hann


    Unique in addressing two different problems - sound visualization and manipulation - in a unified way Advances in signal processing technology are enabling ever more accurate visualization of existing sound fields and precisely defined sound field production. The idea of explaining both the problem of sound visualization and the problem of the manipulation of sound within one book supports this inter-related area of study.  With rapid development of array technologies, it is possible to do much in terms of visualization and manipulation, among other technologies involved with the spatial dis

  17. Graphene-on-paper sound source devices. (United States)

    Tian, He; Ren, Tian-Ling; Xie, Dan; Wang, Yu-Feng; Zhou, Chang-Jian; Feng, Ting-Ting; Fu, Di; Yang, Yi; Peng, Ping-Gang; Wang, Li-Gang; Liu, Li-Tian


    We demonstrate an interesting phenomenon that graphene can emit sound. The application of graphene can be expanded in the acoustic field. Graphene-on-paper sound source devices are made by patterning graphene on paper substrates. Three graphene sheet samples with the thickness of 100, 60, and 20 nm were fabricated. Sound emission from graphene is measured as a function of power, distance, angle, and frequency in the far-field. The theoretical model of air/graphene/paper/PCB board multilayer structure is established to analyze the sound directivity, frequency response, and efficiency. Measured sound pressure level (SPL) and efficiency are in good agreement with theoretical results. It is found that graphene has a significant flat frequency response in the wide ultrasound range 20-50 kHz. In addition, the thinner graphene sheets can produce higher SPL due to its lower heat capacity per unit area (HCPUA). The infrared thermal images reveal that a thermoacoustic effect is the working principle. We find that the sound performance mainly depends on the HCPUA of the conductor and the thermal properties of the substrate. The paper-based graphene sound source devices have highly reliable, flexible, no mechanical vibration, simple structure and high performance characteristics. It could open wide applications in multimedia, consumer electronics, biological, medical, and many other areas.

  18. A Miniature Robotic Plane Meteorological Sounding System

    Institute of Scientific and Technical Information of China (English)

    马舒庆; 陈洪滨; 汪改; 潘毅; 李强


    This article presents a miniature robotic plane meteorological sounding system RPMSS), which consists of three major subsystems: a miniature robotic plane, an air-borne meteorological sounding and flight control system, and a ground-based system. Take-off and landing of the miniature aircraft are guided by radio control, and the flight of the robotic plane along a pre-designed trajectory is automatically piloted by an onboard navigation system. The observed meteorological data as well as all flight information are sent back in real time to the ground, then displayed and recorded by the ground-based computer. The ground-based subsystem can also transmit instructions to the air-borne control subsystem. Good system performance has been demonstrated by more than 300 hours of flight for atmospheric sounding.

  19. Simulation of Sound Waves Using the Lattice Boltzmann Method for Fluid Flow: Benchmark Cases for Outdoor Sound Propagation


    Erik M. Salomons; Lohman, Walter J. A.; Han Zhou


    Propagation of sound waves in air can be considered as a special case of fluid dynamics. Consequently, the lattice Boltzmann method (LBM) for fluid flow can be used for simulating sound propagation. In this article application of the LBM to sound propagation is illustrated for various cases: free-field propagation, propagation over porous and non-porous ground, propagation over a noise barrier, and propagation in an atmosphere with wind. LBM results are compared with solutions of the equation...

  20. Sound absorption and reflection with coupled tubes

    NARCIS (Netherlands)

    Eerden, van der Frits


    This paper describes a special sound absorbing technique with an accompanying efficient numerical design tool. As a basis pressure waves in a single narrow tube or pore are considered. In such a tube the viscosity and the thermal conductivity of the air, or any other fluid, can have a significant ef

  1. Pelapisan Alloy FeNiAl Menggunakan Metode Detonation Gun (D-Gun

    Directory of Open Access Journals (Sweden)

    M.R.T. Siregar


    Full Text Available Pelapisan material alloy Fe38Ni10Al dilakukan dengan metode D-Gun untuk meningkatkan kekerasan material Stainless Steel AISI 316 L. Analisis parameter proses dilakukan dengan perangkat statistik ANOVA (Analysis of Variance – Taguchi untuk memperoleh ukuran kristal, ketebalan dan tingkat kekerasan yang optimum. Lapisan paling tebal dimiliki oleh sampel SS03 sebesar 280 mikron, sedangkan sampel SS02 memiliki ketebalan paling rendah, 97 mikron. Ketebalan lapisan sangat dipengaruhi oleh laju aliran gas pembawa serbuk dengan rasio kontribusi sebesar 82, 7%. Kekerasan optimum diperoleh sampel SS08 dengan tingkat kekerasan sebesar 281,6 HV yang jauh lebih besar dari tingkat kekerasan Stainless Steel tanpa lapisan (195,0 HV. Analisis struktur dan ukuran kristal dilakukan dengan menggunakan XRD dan Metode Scherrer yang menghasilkan struktur kristal Taenite (γ-(Fe,Ni dengan ukuran kristal pada orde nanometer (nanokristal pada kisaran 27,5 hingga 37,7 nm. Ukuran kristal sangat dipengaruhi oleh parameter rasio gas asetilene – oksigen dengan rasio kontribusi 60,4 %. Kata kunci: Detonation Gun (D-Gun, ANOVA –Taguchi, XRD, Nanokristal, Metode Scherer, Tingkat Kekerasan (Hardness

  2. Urban sound ecologies

    Directory of Open Access Journals (Sweden)

    Sanne Krogh Groth


    Full Text Available Within recent years, there has been a renewed focus on sound in urban environments. From sound installations in public space to sound festivals in alternative settings, we find a common interest in sound art relating to the urban environment. Artworks or interventions presented in such contexts share the characteristics of site specificity. However, this article will consider the artwork in a broader context by re-examining how sound installations relate to the urban environment. For that purpose, this article brings together ecology terms from acoustic ecology of the sound theories of the 1970s while developing them into recent definitions of ecology in urban studies. Finally, we unfold our framing of urban sound ecologies with three case analyses: a sound intervention in Berlin, a symphony for wind instruments in Copenhagen and a video walk in a former railway station in Kassel. The article concludes that the ways in which recent sound installations work with urban ecologies vary. While two of the examples blend into the urban environment, the other transfers the concert format and its mode of listening to urban space. Last, and in accordance with recent soundscape research, we point to how artists working with new information and media technologies create inventive ways of inserting sound and image into urban environments.

  3. Smart Gun Technology project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D.R.


    The goal of the Smart Gun Technology project is to eliminate the capability of an unauthorized user form firing a law officer`s firearm by implementing user-recognizing-and-authorizing (or {open_quotes}smart{close_quotes}) surety technologies. This project was funded by the National Institute of Justice. This report lists the findings and results of the project`s three primary objectives. First, to find and document the requirements for a smart firearm technology that law enforcement officers will value. Second, to investigate, evaluate, and prioritize technologies that meet the requirements for a law enforcement officer`s smart firearm. Third, to demonstrate and document the most promising technology`s usefulness in models of a smart firearm.

  4. Quantitative Testing of Defect for Gun Barrels

    Institute of Scientific and Technical Information of China (English)

    WANG Chang-long; JI Feng-zhu; WANG Jin; CHEN Zheng-ge


    The magnetic flux leakage (MFL) method is commonly used in the nondestructive evaluation (NDE) of gun barrels. The key point of MFL testing is to estimate the crack geometry parameters based on the measured signal. The analysis of magnetic leakage fields can be obtained by solving Maxwell's equations using finite element method (FEM).The radial component of magnetic flux density is measured in MFL testing. The peak-peak value, the separation distance between positive and negative peaks of signal and the lift-off value of Hall-sensor are used as the main features of every sample. This paper establishes the multi-regression equations related to the width (the depth) of crack and the main characteristic values. The regression model is tested by use of the magnetic leakage data. The experimental results indicate that the regression equations can accurately predict the 2-D defect geometry parameters and the MFL quantitative testing can be achieved.

  5. Projectile Balloting Attributable to Gun Tube Curvature

    Directory of Open Access Journals (Sweden)

    Michael M. Chen


    Full Text Available Transverse motion of a projectile during launch is detrimental to firing accuracy, structural integrity, and/or on-board electronics performance of the projectile. One manifest contributing factor to the undesired motion is imperfect bore centerline straightness. This paper starts with the presentation of a deterministic barrel model that possesses both vertical and lateral deviations from centerline in accordance with measurement data, followed by a novel approach to simulating comprehensive barrel centerline variations for the investigation of projectile balloting^1 motions. A modern projectile was adopted for this study. In-bore projectile responses at various locations of the projectile while traveling through the simulated gun tubes were obtained. The balloting was evaluated in both time and frequency domains. Some statistical quantities and the significance were outlined.

  6. Gun culture and symbolism among U.K. and U.S. women. (United States)

    Cooke, C A; Puddifoot, J E


    The authors explored attitudes of young women in the United Kingdom (n = 108) and the United States (n = 91) toward (a) the possession and use of guns through the Attitude to Guns Scale (N. R. Branscombe, J. A. Weir, & P. Crosby, 1992) and (b) guns' perceived functional and symbolic significance through the Symbolic Nature of Guns Scale (C. A. Cooke & J. E. Puddifoot, 1997). There were significant differences in beliefs concerning the right to own a gun and the protective effect of guns but not in the perceived contribution of guns to crime. Although neither group strongly equated guns symbolically with power or control, the U.S. women were more likely to perceive guns as expressions of freedom or independence, and the U.K. women were more likely to view guns as expressions of danger and violence. The findings were contextualized by comparison with samples of male control participants of similar ages.

  7. Energy partitioning in an inductively driven rail gun (United States)

    Sen, K. K.; Ray, P. K.


    The equations describing the performance of an inductively driven rail are analyzed numerically. Friction between the projectile and rails is included through an empirical formulation. The equations are applied to the experiment of Rashleigh and Marshall to obtain an estimate of energy distribution in rail guns as a function of time. It is found that only 15 percent of energy delivered by the inductor to the gun is transformed into the kinetic energy of the projectile. This study provides an insight into the nature of nonlinear coupling involved in the electromechanical interactions in a rail gun.

  8. The internal ballistics of a high: low pressure gun

    Directory of Open Access Journals (Sweden)

    J. N. Kapur


    Full Text Available In the present paper the system of equations for the Non-Isothermal Model for a H/L gun has been developed and from this, the systems of equations for Isothermal and Non-isothermal models for orthodox gun and solid fuel rockets have been deduced. The Non-Isothermal Model for H/L gun has been integrated for a tubular charge. For isothermal model, reduction to an equivalent non-leaking problem has been discussed and the partially non-isothermal model has been integrated for the linear law. After all-burnt modification needed in Corner's energy equation is obtained.

  9. Development of Subcaliber Projectiles for the Hispano-Suiza Gun (United States)


    SUBOALIBER PRO JECTILES FOR THE HISPANO- SUIZA GUN 𔃺TECMEPUC-lT, TJ 0 ABERDEEN P 𔃺i7 CiiTDM. ST~lU-TL A T, 1?7,, by CTa * UG r C. L. Critchfield I P I, 2...FOR THE HISPANO- SUIZA GUN by C. L. Critchfield and J. McG. Millar TECiN•IcAr ABERDE " , :PT’- , Approved on November 12, 1943 for submission...Hispano- Suiza gun ....... 6 2. 20-ram sabot-projectiles of Series B and C ......... ... 12 3. Type C2 at h ft from the muzzle . .......... . 13 h. The 20

  10. Ultra-low emittance X-band photocathode RF gun

    Institute of Scientific and Technical Information of China (English)

    TANG Chuan-Xiang; LIU Xiao-Han


    In this paper,we present the simulation results of a 1.6 cell X-band photocathode RF gun for ultra-low emittance electron beams.It will work at 9.3 GHz.The emittance,bunch length,electron energy and energy spread at the gun exit are optimized at bunch charge of 1pC using PARMELA.Electron bunches type coupler is adopted in this gun and an initial simulation by MAFIA is also given in this paper.

  11. Dynamic Response and Fracture of Composite Gun Tubes

    Directory of Open Access Journals (Sweden)

    Jerome T. Tzeng


    Full Text Available The fracture behavior due to dynamic response in a composite gun tube subjected to a moving pressure has been investigated. The resonance of stress waves result in very high amplitude and frequency strains in the tube at the instant and location of pressure front passage as the velocity of the projectile approaches a critical value. The cyclic stresses can accelerate crack propagation in the gun tube with an existing imperfection and significantly shorten the fatigue life of gun tubes. The fracture mechanism induced by dynamic amplification effects is particularly critical for composite overwrap barrels because of a multi-material construction, anisotropic material properties, and the potential of thermal degradation.

  12. Method of electron emission control in RF guns

    CERN Document Server

    Khodak, I V


    The electron emission control method for a RF gun is considered.According to the main idea of the method,the additional resonance system is created in a cathode region where the RF field strength could be varied using the external pulse equipment. The additional resonance system is composed of a coaxial cavity coupled with a RF gun cylindrical cavity via an axial hole. Computed results of radiofrequency and electrodynamic performances of such a two-cavity system and results of the RF gun model pilot study are presented in. Results of particle dynamics simulation are described.


    Directory of Open Access Journals (Sweden)

    C. Monick


    Full Text Available On 14 February 1992 there occurred the official opening of the Dan Pienaar Gun Park at the South African National Museum of Military History. The Gun Park is a newly completed exhibition area created by roofing and repairing the central courtyard between the exhibition's main halls. Lt Gen G L Meiring, SSA, SO, officially opened the Dan Pienaar Gun Park. The statue of Maj Gen D H ('Dan' Pienaar was officially unveiled by his widow (now Mrs Norma Seuffert. Maj Gen Pienaar's children, Fay, Barry and Nelia, were also present, in addition to a very wide representation of the Pienaar family.

  14. Sound a very short introduction

    CERN Document Server

    Goldsmith, Mike


    Sound is integral to how we experience the world, in the form of noise as well as music. But what is sound? What is the physical basis of pitch and harmony? And how are sound waves exploited in musical instruments? Sound: A Very Short Introduction looks at the science of sound and the behaviour of sound waves with their different frequencies. It also explores sound in different contexts, covering the audible and inaudible, sound underground and underwater, acoustic and electronic sound, and hearing in humans and animals. It concludes with the problem of sound out of place—noise and its reduction.

  15. Brief use of a specific gun in a violent game does not affect attitudes towards that gun (United States)

    Engelhardt, Christopher R.; Bartholow, Bruce D.


    Although much attention has been paid to the question of whether violent video games increase aggressive behaviour, little attention has been paid to how such games might encourage antecedents of gun violence. In this study, we examined how product placement, the attractive in-game presentation of certain real-world firearm brands, might encourage gun ownership, a necessary antecedent of gun violence. We sought to study how the virtual portrayal of a real-world firearm (the Bushmaster AR-15) could influence players' attitudes towards the AR-15 specifically and gun ownership in general. College undergraduates (N = 176) played one of four modified video games in a 2 (gun: AR-15 or science-fiction control) × 2 (gun power: strong or weak) between-subjects design. Despite collecting many outcomes and examining many potential covariates and moderators, experimental assignment did little to influence outcomes of product evaluations or purchasing intentions with regard to the AR-15. Attitudes towards public policy and estimation of gun safety were also not influenced by experimental condition, although these might have been better tested by comparison against a no-violence control condition. By contrast, gender and political party had dramatic associations with all outcomes. We conclude that, if product placement shapes attitudes towards firearms, such effects will need to be studied with stronger manipulations or more sensitive measures. PMID:28018611

  16. Design of a Compact Coaxial Magnetized Plasma Gun for Magnetic Bubble Expansion Experiments (United States)


    COAXIAL MAGNETIZED PLASMA GUN FOR MAGNETIC BUBBLE EXPANSION EXPERIMENTS Y. Zhang1, A. G. Lynn1, S. C. Hsu2, M. Gilmore1, C... coaxial magnetized plasma gun and its associated hardware systems are discussed in detail. The plasma gun is used for experimental studies of...and coaxial plasma guns - which is the method employed in this work. The first coaxial plasma gun experiment was performed five decades ago by

  17. InfoSound

    DEFF Research Database (Denmark)

    Sonnenwald, Diane H.; Gopinath, B.; Haberman, Gary O.


    The authors explore ways to enhance users' comprehension of complex applications using music and sound effects to present application-program events that are difficult to detect visually. A prototype system, Infosound, allows developers to create and store musical sequences and sound effects...... helped users detect rapid, multiple-event sequences that were difficult to visually detect using text and graphical interfaces. The authors describe the architecture of InfoSound, the use of the system, and the lessons learned....

  18. Comfort in Sound

    Institute of Scientific and Technical Information of China (English)



    @@ Drown your winter sorrows in sound with these three top surround-sound systems With winter here, it is time to start considering ways to improve your home entertainment options. While a good DVD or Blu-ray player and games console should keep you happily occupied without needing to leave the warmth of your apartment, investing in a cutting-edge surround sound system wiU ensure that winter passes without you even noticing.

  19. Urban Sound Ecologies

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh; Samson, Kristine


    of the 1970s while developing them into recent definitions of ecology in urban studies. Finally, we unfold our framing of urban sound ecologies with three case analyses: a sound intervention in Berlin, a symphony for wind instruments in Copenhagen and a video walk in a former railway station in Kassel...... to how artists working with new information and media technologies create inventive ways of inserting sound and image into urban environments....

  20. Light and Sound

    CERN Document Server

    Karam, P Andrew


    Our world is largely defined by what we see and hear-but our uses for light and sound go far beyond simply seeing a photo or hearing a song. A concentrated beam of light, lasers are powerful tools used in industry, research, and medicine, as well as in everyday electronics like DVD and CD players. Ultrasound, sound emitted at a high frequency, helps create images of a developing baby, cleans teeth, and much more. Light and Sound teaches how light and sound work, how they are used in our day-to-day lives, and how they can be used to learn about the universe at large.

  1. Hartford's gun buy-back program: are we on target? (United States)

    Marinelli, Laura W; Thaker, Shefali; Borrup, Kevin; Shapiro, David S; Bentley, George C; Saleheen, Hassan; Lapidus, Garry; Campbell, Brendan T


    Gunbuy-backprograms have been proposed as away to remove unwanted firearms from circulation, but remain controversial because their ability to prevent firearm injuries remains unproven. The purpose of this study is to describe the demographics of individuals participating in Connecticut's gun buy-backprogram in the context of annual gun sales and the epidemiology of firearm violence in the state. Over four years the buy-back program collected 464 firearms, including 232 handguns. In contrast, 91,602 firearms were sold in Connecticut during 2009 alone. The incidence of gun-related deaths was unchanged in the two years following the inception of the buy-back program. Suicide was associated with older age (mean = 51 +/- 18years) and Caucasian race (n = 539, 90%). Homicide was associated with younger age (mean = 30 +/- 12 years) and minority race (n = 425, 81%). A gun buy-back program alone is not likely to produce a measurable decrease in firearm injuries and deaths.

  2. Cold Test Measurements on the GTF Prototype RF Gun

    Energy Technology Data Exchange (ETDEWEB)

    Gierman, S.M.


    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. Based on longitudinal phase space measurements showing a correlated energy spread the gun was removed and re-characterized in 2002. The low power RF measurements performed on the gun are described below. Perturbative bead measurements were performed to determine the field ratio in the two-cell gun, and network analyzer measurements were made to characterize the mode structure. A second probe was installed to monitor the RF field in the first cell, and a diagnostic was developed to monitor the high-power field ratio. Calibration of the RF probes, a model for analyzing RF measurements, and Superfish simulations of bead and RF measurements are described.

  3. Canvasback Gun Club : Submerged aquatic plant survey : 1986 (United States)

    US Fish and Wildlife Service, Department of the Interior — Flood waters which impacted the Stillwater Wildlife Management Area for the past several years also had their effect on the northern portions of the Canvasback Gun...

  4. Refractory Gunning Material for Inner Lining Maintenance of Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan; Peng Xigao


    @@ 1 Scope This standard specifies the term and definition,classification, technical requirements, test methods,quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of refractory gunning material for inner lining maintenance of blast furnace .

  5. Alternating Current All-electrical Gun Control System in Tanks

    Directory of Open Access Journals (Sweden)

    Zang Kemao


    Full Text Available The ac all-electrical gun control system is composed of permanent magnetic synchronous machine-drive control systems and the ball-screw by replacing the complicated electrohydraulic systems. At the same time, the variable-structure system with sliding modes makes the gun control systems to have higher performances using the only rate flexure gyroscope. Thereby, vehicle hull gyroscope and angular gyroscope are left out.The new ac all-electrical gun control systems developed are reduced by 40 per cent in weight, decreased by 30 per cent in volume, increased by 35 per cent in efficiency, and enhanced by three times in service life as compared to the current gun control systems.

  6. Mystery of the First Russian Rifle Naval Guns

    Directory of Open Access Journals (Sweden)

    Nicholas W. Mitiukov


    Full Text Available In 1859 France completed the first ocean-going ironclad warship, «La Gloire», and changed the definition of naval power completely. Russia, as all the other Powers, found that her most powerful naval gun, the 60-pdr, was insufficient for modern warfare, and realized the future naval armament relied on heavy rifled artillery. Both the Army and Navy began purchasing such cannon from foreign providers until a suitable domestic weapon could be produced. The relationship between the Russian military and Krupp is well known. But there was another provided, the Blakely Ordnance Company in England sold many guns to the Army and Navy, beginning with 8-inch MLR in early 1863 to a large number of 9- and 11-inch guns. Deliveries began in November 1863 and continued until mid-1866. But no sources on the armament of Russian ships and fortresses mentions these guns. What happened to them is a mystery.

  7. Experimental study on HVAC sound parameters (United States)

    Bujoreanu, C.; Benchea, M.


    HVAC system represent major source of buildings internal noise and therefore they are designed to provide a human acoustic comfort besides the thermal and air quality requirements. The paper experimentally investigates three types of commercial air handler units (AHU) with different ducts cross-section sizes and inlet-outlet configuration. The measurements are performed in an anechoic room. The measurements are carried out at different fan's speeds, ranging the power-charge from 30-100% while the duct air flow is slowly adjusted from full open to full closed, between 0-500 Pa. The sound pressure levels of the radiant units are rated using NR curves. Also, the supply and the outdoor ducts sound levels are compared in order to point the frequencies where the noise must be reduced. Third-octave band analysis of random noise of an air handling unit from a HVAC system is realized, using measurement procedures that agrees the requirements of the ISO 3744:2011 and ISO 5136:2010 standards. The comparatively results highlight the effects of the geometry, air flow pressure and power-charging dependencies upon the sound level. This is the start for a noise reduction strategy.


    Energy Technology Data Exchange (ETDEWEB)

    Vandersall, K S; Behn, A; Gresshoff, M; Jr., L F; Chiao, P I


    A new gas gun capability is being activated at Lawrence Livermore National Laboratories located in the High Explosives Applications Facility (HEAF). The single stage light gas (dry air, nitrogen, or helium) gun has interchangeable barrels ranging from 25.4 mm to 76.2 mm in diameter with 1.8 meters in length and is being fabricated by Physics Applications, Inc. Because it is being used for safety studies involving explosives, the gun is planned for operation inside a large enclosed firing tank, with typical velocities planned in the range of 10-300 m/s. Three applications planned for this gun include: low velocity impact of detonator or detonator/booster assemblies with various projectile shapes, the Steven Impact test that involves impact initiation of a cased explosive target, and the Taylor impact test using a cylindrical explosive sample impacted onto a rigid anvil for fracture studies of energetic materials. A highlight of the gun features, outline on work in progress for implementing this capability, and discussion of the planned areas of research will be included.

  9. Cylinder expansion test and gas gun experiment comparison

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    This is a summer internship presentation by the Hydro Working Group at Los Alamos National Laboratory (LANL) and goes into detail about their cylinder expansion test and gas gun experiment comparison. Specifically, the gas gun experiment is detailed along with applications, the cylinder expansion test is detailed along with applications, there is a comparison of the methods with pros and cons and limitations listed, the summer project is detailed, and future work is talked about.

  10. Efficiency of guns from the technical point of view

    Directory of Open Access Journals (Sweden)

    G. Baranski


    Full Text Available From the engineering point of view, a gun or machine gun is a heat engine very similar to a Diesel or petrol engine. It has to do work when-operated by a soldier. A fuel is burnt, namely the propellant, and certain power (energy per unit time is obtained, namely the kinetic energy of the projectile for each interval of rounds fired.

  11. RF gun for an intense THz radiation source

    Institute of Scientific and Technical Information of China (English)

    GU Qiang; ZHAO Zhen-Tang; TONG De-Chun; CHEN Li-Fang; XU Xiu-Min


    A new facility is under construction at the Shanghai Institute of Applied Physics,to generate femto-second electron bunches and intense coherent THz radiation pulses.A thermionic RF-gun is used to be the electron source of the linac,which is 1.6 cell,π/2,side coupled in design.In the following of this paper,the design,manufacture and beam operation of this gun are presented.

  12. Plasma gun with coaxial powder feed and adjustable cathode (United States)

    Zaplatynsky, Isidor (Inventor)


    An improved plasma gun coaxially injects particles of ceramic materials having high melting temperatures into the central portion of a plasma jet. This results in a more uniform and higher temperature and velocity distribution of the sprayed particles. The position of the cathode is adjustable to facilitate optimization of the performance of the gun wherein grains of the ceramic material are melted at lower power input levels.

  13. Nitramine-Based High Energy Propellant Compositions for Tank Guns


    R.S. Damse; Haridwar Singh


    Six different RDX-based gun propellant compositions have been formulated and studied to select the most suitable composition for tank gun ammunition in terms of higher force constant at relatively lower flame temperature (T). Ballistic'performance of the compositions was evaluated on the basis of closed vessel test. JIea(energy was determined using a bomb calorimeter. Sensitivity, thermal characteristics, stability and mechanical properties of the compositions were studied for assessing their...

  14. Resistance Spot Welding with Middelfrequency-Inverter Weling Gun

    DEFF Research Database (Denmark)

    Rasmussen, Mogens H.

    The paper presents the results of investigations concerning the process stability and weldability lobes for uncoated sheets of 1.0 mm thickness when performing resistance spot welding with a middlefrequency-inverter welding gun......The paper presents the results of investigations concerning the process stability and weldability lobes for uncoated sheets of 1.0 mm thickness when performing resistance spot welding with a middlefrequency-inverter welding gun...

  15. Contoured-gap coaxial guns for imploding plasma liner experiments (United States)

    Witherspoon, F. D.; Case, A.; Brockington, S.; Cassibry, J. T.; Hsu, S. C.


    Arrays of supersonic, high momentum flux plasma jets can be used as standoff compression drivers for generating spherically imploding plasma liners for driving magneto-inertial fusion, hence the name plasma-jet-driven MIF (PJMIF). HyperV developed linear plasma jets for the Plasma Liner Experiment (PLX) at LANL where two guns were successfully tested. Further development at HyperV resulted in achieving the PLX goal of 8000 μg at 50 km/s. Prior work on contoured-gap coaxial guns demonstrated an approach to control the blowby instability and achieved substantial performance improvements. For future plasma liner experiments we propose to use contoured-gap coaxial guns with small Minirailgun injectors. We will describe such a gun for a 60-gun plasma liner experiment. Discussion topics will include impurity control, plasma jet symmetry and topology (esp. related to uniformity and compactness), velocity capability, and techniques planned for achieving gun efficiency of >50% using tailored impedance matched pulse forming networks. Mach2 and UAH SPH code simulations will be included. Work supported by US DOE DE-FG02-05ER54810.

  16. Engineering design of the PLX- α coaxial gun (United States)

    Cruz, Edward; Brockington, Samuel; Case, Andrew; Luna, Marco; Witherspoon, Douglas; Langendorf, Samuel


    We describe the engineering and technical aspects of the coaxial gun designed for the 60-gun scaling study of spherically imploding plasma liners as a standoff driver for plasma-jet-driven magneto-inertial fusion. Each coaxial gun incorporates a fast, dense gas injection and triggering system, a compact low-weight pfn with integral sparkgap switching, and a contoured gap designed to suppress the blow-by instability. Alpha1 and Alpha2 guns are compared, with emphasis on the improvements on Alpha2, which include a faster more robust gas valve, an improved electrode contour, a custom 600- μF, 5-kV pfn, and a set of six inline sparkgap switches operated in parallel. The switch and pfn configurations are mounted directly to the back of the gun, and are designed to reduce inductance, cost, and complexity, maximize efficiency and system reliability, and ensure symmetric current flow. We will provide a detailed overview of the design choices made for the PLX- α coaxial gun. This work supported by the ARPA-E ALPHA Program.

  17. Notes on Sound

    Directory of Open Access Journals (Sweden)

    Bonnie Jones


    Full Text Available Bonnie Jones creates improvised and composed text-sound performances that explore the fluidity and function of electronic noise (field recordings, circuit bending and text (poetry, found, spoken. She is interested in how people perceive, “read” and interact with these sounds and texts given our current technological moment.

  18. Breaking the Sound Barrier (United States)

    Brown, Tom; Boehringer, Kim


    Students in a fourth-grade class participated in a series of dynamic sound learning centers followed by a dramatic capstone event--an exploration of the amazing Trashcan Whoosh Waves. It's a notoriously difficult subject to teach, but this hands-on, exploratory approach ignited student interest in sound, promoted language acquisition, and built…

  19. Light and sound

    Institute of Scientific and Technical Information of China (English)



    Light travels at a speed which is about a million times faster than the speed of sound.In one second,light travels about 300,000 km,but sound travels only 314m,you can get some idea of this difference(区别) by watching the start of a race.

  20. Inferring agency from sound

    NARCIS (Netherlands)

    Knoblich, G.K.; Repp, B.H.


    In three experiments we investigated how people determine whether or not they are in control of sounds they hear. The sounds were either triggered by participants’ taps or controlled by a computer. The task was to distinguish between self-control and external control during active tapping, and durin

  1. Hamiltonian Algorithm Sound Synthesis


    大矢, 健一


    Hamiltonian Algorithm (HA) is an algorithm for searching solutions is optimization problems. This paper introduces a sound synthesis technique using Hamiltonian Algorithm and shows a simple example. "Hamiltonian Algorithm Sound Synthesis" uses phase transition effect in HA. Because of this transition effect, totally new waveforms are produced.

  2. Waveform analysis of sound

    CERN Document Server

    Tohyama, Mikio


    What is this sound? What does that sound indicate? These are two questions frequently heard in daily conversation. Sound results from the vibrations of elastic media and in daily life provides informative signals of events happening in the surrounding environment. In interpreting auditory sensations, the human ear seems particularly good at extracting the signal signatures from sound waves. Although exploring auditory processing schemes may be beyond our capabilities, source signature analysis is a very attractive area in which signal-processing schemes can be developed using mathematical expressions. This book is inspired by such processing schemes and is oriented to signature analysis of waveforms. Most of the examples in the book are taken from data of sound and vibrations; however, the methods and theories are mostly formulated using mathematical expressions rather than by acoustical interpretation. This book might therefore be attractive and informative for scientists, engineers, researchers, and graduat...

  3. Advanced Concepts of the Propulsion System for the Futuristic Gun Ammunition

    Directory of Open Access Journals (Sweden)

    R.S. Darnse


    Full Text Available This review paper reports various concepts of the gun propulsion system to meet the goal of the futuristic hypervelocity projectiles. The nonconventional concepts, such as liquid gun propellant, rail gun, coil gun, electrothermal gun, electrothermal chemical gun along with conventional energetic solid gun propellant have been discussed. Even though muzzle velocity around 2000 m/s has been claimed to be achieved using such nonconventional propulsion systems, it will take quite some time before such systems are in regular use in the battlefield. Hence, solid gun propellants containing novel energetic ingredients (binders, plasticisers, and oxidisers would continue to be used in the near future and are expected to meet the requirements of the futuristic gun ammunition.

  4. Wind Turbine Noise and Natural Sounds: Masking, Propagation and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Bolin, Karl


    Wind turbines are an environmentally friendly and sustainable power source. Unfortunately, the noise impact can cause deteriorated living conditions for nearby residents. The audibility of wind turbine sound is influenced by ambient sound. This thesis deals with some aspects of noise from wind turbines. Ambient sounds influence the audibility of wind turbine noise. Models for assessing two commonly occurring natural ambient sounds namely vegetation sound and sound from breaking waves are presented in paper A and B. A sound propagation algorithm has been compared to long range measurements of sound propagation in paper C. Psycho-acoustic tests evaluating the threshold and partial loudness of wind turbine noise when mixed with natural ambient sounds have been performed. These are accounted for in paper D. The main scientific contributions are the following.Paper A: A semi-empiric prediction model for vegetation sound is proposed. This model uses up-to-date simulations of wind profiles and turbulent wind fields to estimate sound from vegetation. The fluctuations due to turbulence are satisfactory estimated by the model. Predictions of vegetation sound also show good agreement to measured spectra. Paper B: A set of measurements of air-borne sound from breaking waves are reported. From these measurements a prediction method of sound from breaking waves is proposed. Third octave spectra from breaking waves are shown to depend on breaker type. Satisfactory agreement between predictions and measurements has been achieved. Paper C: Long range sound propagation over a sea surface was investigated. Measurements of sound transmission were coordinated with local meteorological measurements. A sound propagation algorithm has been compared to the measured sound transmission. Satisfactory agreement between measurements and predictions were achieved when turbulence were taken into consideration in the computations. Paper D: The paper investigates the interaction between wind

  5. Age, Poverty, Homicide, and Gun Homicide

    Directory of Open Access Journals (Sweden)

    Mike Males


    Full Text Available Traditional theories of “adolescent risk taking” have not been validated against recent research indicating that youthful traffic crash, violent crime, felony crime, and firearms mortality rates reflect young people’s low-socio-economic status (SES compared with older adults’, not young age. Aside from a small number of recent, conflicting studies, the literature gap on this key issue remains. The present study examines the 54,094 homicide deaths, including 41,123 gun homicides, victimizing California residents ages 15 to 69 during 1991 to 2012 by poverty status. Without controlling for poverty, homicide rates display the traditional age-curve peaking at 19, then declining. When poverty is controlled, the traditional age-curve persists only for high-poverty populations, in which young people are vastly over-represented, and homicide rates are elevated for all ages. This finding reiterates that “adolescent risk taking” may be an artifact of failing to control for age-divergent SES.

  6. A novel electron gun for inline MRI-linac configurations

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, Dragoş E., E-mail:; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Holloway, Lois [Liverpool and Macarthur Cancer Therapy Centres, The University of Sydney, NSW 2006 (Australia); Keall, Paul J. [Radiation Physics Laboratory, The University of Sydney, NSW 2006 (Australia)


    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T

  7. Properties of a Sound Wave



    This interactive tutorial covers the following properties of sound wave: frequency, period, amplitude, total pressure, ambient pressure, and peak sound pressure. Students need to have a sound card on their computer and speakers to hear the sounds produced. The interactions in this tutorial include: Mouse over some text for visual explanations., Varying the frequency and amplitude of a sound wave, and be able to listen to the changing pitch of the sound., A short self-check quiz. PH2401 ...

  8. Lung Sounds in Bronchial Asthma

    Directory of Open Access Journals (Sweden)

    Yukio Nagasaka


    In lung sound analysis, the narrower the airways are, the higher the frequency of breathing sounds is, and, if a patient has higher than normal breathing sounds, i.e., bronchial sounds, he or she may have airway narrowing or airway inflammation. It is sometimes difficult to detect subtle changes in lung sounds; therefore, we anticipate that automated analysis of lung sounds will be used to overcome these difficulties in the near future.

  9. Rheological and Adhesive Behavior of Gunning Mix for Blast Furnace Repair

    Institute of Scientific and Technical Information of China (English)

    CAO Feng; LONG Shigang; WU Xingrong; SUN Jialin; HONG Yanruo


    The aim of this experimental work was to investigate the rheological and adhesive performance of gunning mix suspensions. The results of rheological tests indicate that:the rheological curve of gunning mix bonded by high-alumina cement (HACG) is Bingham type; the rheological curve of low cement gunning mix (LCG) bonded by microsilica is characterized by pseudo-plasticity fluid with yielding stress; and the rheological property of low-cement gunning mix bonded by microsilica is proved to be better than that of gunning mix bonded by cement. Meanwhile as indicated by the adhesive tests: the better the rheological properties of gunning mix suspension, the better the repair effect would be.

  10. Sound as artifact (United States)

    Benjamin, Jeffrey L.

    A distinguishing feature of the discipline of archaeology is its reliance upon sensory dependant investigation. As perceived by all of the senses, the felt environment is a unique area of archaeological knowledge. It is generally accepted that the emergence of industrial processes in the recent past has been accompanied by unprecedented sonic extremes. The work of environmental historians has provided ample evidence that the introduction of much of this unwanted sound, or "noise" was an area of contestation. More recent research in the history of sound has called for more nuanced distinctions than the noisy/quiet dichotomy. Acoustic archaeology tends to focus upon a reconstruction of sound producing instruments and spaces with a primary goal of ascertaining intentionality. Most archaeoacoustic research is focused on learning more about the sonic world of people within prehistoric timeframes while some research has been done on historic sites. In this thesis, by way of a meditation on industrial sound and the physical remains of the Quincy Mining Company blacksmith shop (Hancock, MI) in particular, I argue for an acceptance and inclusion of sound as artifact in and of itself. I am introducing the concept of an individual sound-form, or sonifact , as a reproducible, repeatable, representable physical entity, created by tangible, perhaps even visible, host-artifacts. A sonifact is a sound that endures through time, with negligible variability. Through the piecing together of historical and archaeological evidence, in this thesis I present a plausible sonifactual assemblage at the blacksmith shop in April 1916 as it may have been experienced by an individual traversing the vicinity on foot: an 'historic soundwalk.' The sensory apprehension of abandoned industrial sites is multi-faceted. In this thesis I hope to make the case for an acceptance of sound as a primary heritage value when thinking about the industrial past, and also for an increased awareness and acceptance

  11. Gun availability and use of guns for suicide, homicide, and murder in Canada. (United States)

    Bridges, F Stephen; Kunselman, Julie C


    A reliability check of Lester's (2000b) 1970-1995 time series that examined associations between the availability of firearms and their use for homicide and suicide in Canada. For the period 1974 to 1999, the relative availability of firearms as measured by the rate of accidental death from firearms and the average of the percentages of suicides + homicides using firearms was positively associated with the rate of homicide by firearms but not negatively associated with the rate of homicide by all other methods, and positively associated with the rate of suicide by firearms and negatively associated with the rate of suicide by all other methods. Correlations for the homicide versus murder rates, homicide rate using guns versus murder rate using guns, and homicide rate by all other methods versus murder rate by all other methods were very similar. There was a decrease over time of total suicide and homicide rates and firearm suicide and homicide rates, and with a slight indication of substitution of other methods for suicide.

  12. Sound Objects for SVG


    Colbrant, Audrey; Lasorsa, Yohan; Lemordant, Jacques; Liodenot, David; Razafimahazo, Mathieu


    International audience; A sound object can be defined as a time structure of audio chunks whose duration is on the time scale of 100 ms to several seconds. Sound objects have heterogeneous and time-varying properties. They are the basic elements of any format for Interactive Audio (IA). We have designed an XML language, A2ML, for Interactive Audio which offers, concerning the sequencing of sounds, a level of capabilities similar to that of iXMF, the interactive audio file format defined by th...

  13. The sound handbook

    CERN Document Server

    Crook, Tim


    'Tim Crook has written an important and much-needed book, and its arrival on our shelves has come at a highly appropriate time.' Professor Seán Street, Bournemouth UniversityThe Sound Handbook maps theoretical and practical connections between the creation and study of sound across the multi-media spectrum of film, radio, music, sound art, websites, animation and computer games entertainment, and stage theatre. Using an interdisciplinary approach Tim Crook explores the technologies, philosophies and cultural issues involved in making a

  14. Experimenting with End-Correction and the Speed of Sound (United States)

    LoPresto, Michael C.


    What follows is an alternative to the standard tuning fork and quarter-wave tube speed of sound experiment. Rather than adjusting the water level in a glass or plastic tube to vary the length of an air column, a set of resonance tubes of different lengths is used. The experiment still demonstrates the principles of standing waves in air columns…

  15. Study of a laser-heated electron gun (United States)

    Roy, P. K.; Moon, A.; Mima, K.; Nakai, S.; Fujita, M.; Imasaki, K.; Yamanaka, C.; Yasuda, E.; Watanabe, T.; Ohigashi, N.; Okuda, Y.; Tsunawaki, Y.


    A method of cathode heating using a laser was studied for an electron gun. In order to observe the practicality of the heating system, the characteristics of the laser-heated gun with a dispenser and LaB6 thermionic cathodes have been experimentally investigated. The direct laser irradiation is so efficient that the gun is equipped without heat shielding, a cooling system, or an electrical circuit in the gun chamber for cathode heating. Modeling, based on the experimental data, indicates that the cathode temperature is proportional to one-fourth power of the laser power and that laser power loss and conduction loss of heat in the gun assembly are negligible. An electron beam current density 0.48 A/cm2 was measured with 26 W laser power for a dispenser cathode of 0.06 cm2 emission area. Current density 0.16 A/cm2 with 25 W was recorded for a LaB6 cathode of area 0.12 cm2. Electron beam emittance has been measured by using the typical pepper-pot technique. It was observed that the growth of electron beam emittance was very small in the laser heating.

  16. Operation of the superconducting RF photo gun at ELBE

    CERN Document Server

    Teichert, J; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, Ch; Schurig, R; Staufenbiel, F; Xiang, R; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I


    As the first superconducting RF photo-injector (SRF gun) in practical operation, the SRF gun has been successfully connected to the superconducting linac ELBE at Forschungzentrum Dresden-Rossendorf. The injection with this new gun will improve the beam quality for the users of the radiation source. The SRF gun contains a 3½ cell superconducting accelerating cavity with a frequency of 1.3 GHz. The design is for use of normal conducting photocathodes. At present, caesium telluride photocathodes are applied which are illuminated by an ultraviolet laser beam. The kinetic energy of the produced electron beam is 3 MeV which belongs to a peak electric field of 16 MV/m in the cavity. The maximum bunch charge which is obtained and measured in a Faraday cup is about 400 pC (20 μA average current at a repetition rate of 50 kHz). The SRF gun injector is connected to the ELBE accelerator via a dogleg with two 45° deflection magnets. This connection beam line was commissioned in January 2010. A first beam injection into...

  17. Operation of the superconducting RF photo gun at ELBE

    CERN Document Server

    Teichert, J; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, C; Schurig, R; Staufenbiel, F; Xiang, R; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I


    As the first superconducting RF photo-injector (SRF gun) in practical operation, the SRF gun has been successfully connected to the superconducting linac ELBE at Forschungzentrum Dresden-Rossendorf. The injection with this new gun will improve the beam quality for the users of the radiation source. The SRF gun contains a 3½ cell superconducting accelerating cavity with a frequency of 1.3 GHz. The design is for use of normal conducting photocathodes. At present, caesium telluride photocathodes are applied which are illuminated by an ultraviolet laser beam. The kinetic energy of the produced electron beam is 3 MeV which belongs to a peak electric field of 16 MV/m in the cavity. The maximum bunch charge which is obtained and measured in a Faraday cup is about 400 pC (20 µA average current at a repetition rate of 50 kHz). The SRF gun injector is connected to the ELBE accelerator via a dogleg with two 45° deflection magnets. This connection beam line was commissioned in January 2010. A first beam injection into...

  18. rf traveling-wave electron gun for photoinjectors (United States)

    Schaer, Mattia; Citterio, Alessandro; Craievich, Paolo; Reiche, Sven; Stingelin, Lukas; Zennaro, Riccardo


    The design of a photoinjector, in particular that of the electron source, is of central importance for free electron laser (FEL) machines where a high beam brightness is required. In comparison to standard designs, an rf traveling-wave photocathode gun can provide a more rigid beam with a higher brightness and a shorter pulse. This is illustrated by applying a specific optimization procedure to the SwissFEL photoinjector, for which a brightness improvement up to a factor 3 could be achieved together with a double gun output energy compared to the reference setup foreseeing a state-of-the-art S-band rf standing-wave gun. The higher brightness is mainly given by a (at least) double peak current at the exit of the gun which brings benefits for both the beam dynamics in the linac and the efficiency of the FEL process. The gun design foresees an innovative coaxial rf coupling at both ends of the structure which allows a solenoid with integrated bucking coil to be placed around the cathode in order to provide the necessary focusing right after emission.

  19. Sound Insulation between Dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit


    Regulatory sound insulation requirements for dwellings exist in more than 30 countries in Europe. In some countries, requirements have existed since the 1950s. Findings from comparative studies show that sound insulation descriptors and requirements represent a high degree of diversity....... Unfortunately, there is no sign on increasing harmonization, rather the contrary, i.e. evidence for an even more diverse situation in Europe. The studies conclude that harmonization is needed to facilitate exchange of data and construction experience between countries, to reduce trade barriers and to support...... and initiate – where needed – improvement of sound insulation of new and existing dwellings in Europe to the benefit of the inhabitants and the society. A European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs...

  20. Sound insulation between dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit


    Regulatory sound insulation requirements for dwellings exist in more than 30 countries in Europe. In some countries, requirements have existed since the 1950s. Findings from comparative studies show that sound insulation descriptors and requirements represent a high degree of diversity....... Unfortunately, there is no sign on increasing harmonization, rather the contrary, i.e. evidence for an even more diverse situation in Europe. The studies conclude that harmonization is needed to facilitate exchange of data and construction experience between countries, to reduce trade barriers and to support...... and initiate – where needed – improvement of sound insulation of new and existing dwellings in Europe to the benefit of the inhabitants and the society. A European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs...

  1. Underwater Sound Reference Division (United States)

    Federal Laboratory Consortium — The Underwater Sound Reference Division (USRD) serves as the U.S. standardizing activity in the area of underwater acoustic measurements, as the National Institute...

  2. Sound as Popular Culture

    DEFF Research Database (Denmark)

    The wide-ranging texts in this book take as their premise the idea that sound is a subject through which popular culture can be analyzed in an innovative way. From an infant’s gurgles over a baby monitor to the roar of the crowd in a stadium to the sub-bass frequencies produced by sound systems...... in the disco era, sound—not necessarily aestheticized as music—is inextricably part of the many domains of popular culture. Expanding the view taken by many scholars of cultural studies, the contributors consider cultural practices concerning sound not merely as semiotic or signifying processes but as material......, physical, perceptual, and sensory processes that integrate a multitude of cultural traditions and forms of knowledge. The chapters discuss conceptual issues as well as terminologies and research methods; analyze historical and contemporary case studies of listening in various sound cultures; and consider...

  3. Sound classification of dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit


    National schemes for sound classification of dwellings exist in more than ten countries in Europe, typically published as national standards. The schemes define quality classes reflecting different levels of acoustical comfort. Main criteria concern airborne and impact sound insulation between....... Descriptors, range of quality levels, number of quality classes, class intervals, denotations and descriptions vary across Europe. The diversity is an obstacle for exchange of experience about constructions fulfilling different classes, implying also trade barriers. Thus, a harmonized classification scheme...... is needed, and a European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs 2009-2013, one of the main objectives being to prepare a proposal for a European sound classification scheme with a number of quality...


    Institute of Scientific and Technical Information of China (English)


    "Promoting sound and rapid development of the national economy"is China’s goal for economic development in the following five years,as put forward by Hu Jintao, General Secretary of the Central Committee of the Communist Party of China(CPC), in his report to the 17th National Congress of the Party. China used to target"rapid and sound"economic growth.The fact that soundness is preferred to speed for China’s economic growth reflects an important change in the economic outlook of the CPC—China is beginning to value the quality of economic growth rather than the speed. How to attain the goal of sound and rapid development for the national economy is the subject of Hu’s eight-point proposal.

  5. The sound of activism. (United States)

    Sandstrom, B; Vetter, C


    ABSTRACT A longtime advocate for female empowerment and equality, Boden Sandstrom has worked for political change in many arenas. In the 1960s, she began a career as a librarian, but soon made activism her full-time job, working for feminist, leftist and socialist causes. In the 1970s, she found a way to turn her lifelong passion for music into a career as a sound engineer. Once established in that profession, she began donating her services to political events, marches, demonstrations, and rallies. After thirteen years of running her own company, called Woman Sound,Inc. (later City Sound Productions,Inc.), she turned to the study of ethnomusicology. She is now Program Manager and Lecturer for the Ethnomusicology Program at the University of Maryland, where she is also working on her doctorate in that subject. She continues to freelance as a sound engineer and serve as a technical producer for major events.

  6. Propagation of sound

    DEFF Research Database (Denmark)

    Wahlberg, Magnus; Larsen, Ole Næsbye


    As an acoustic signal travels from the source to a receiver, it is affected by a variety of physical processes, all dictated by properties of the signal and the environment. The signal energy is weakened by geometric attenuation as well as absorption by the medium. The temporal and spectral...... properties can be modified by sound absorption, refraction, and interference from multi paths caused by reflections.The path from the source to the receiver may be bent due to refraction. Besides geometrical attenuation, the ground effect and turbulence are the most important mechanisms to influence...... communication sounds for airborne acoustics and bottom and surface effects for underwater sounds. Refraction becomes very important close to shadow zones. For echolocation signals, geometric attenuation and sound absorption have the largest effects on the signals....

  7. Sounds of Web Advertising

    DEFF Research Database (Denmark)

    Jessen, Iben Bredahl; Graakjær, Nicolai Jørgensgaard


    Sound seems to be a neglected issue in the study of web ads. Web advertising is predominantly regarded as visual phenomena–commercial messages, as for instance banner ads that we watch, read, and eventually click on–but only rarely as something that we listen to. The present chapter presents...... an overview of the auditory dimensions in web advertising: Which kinds of sounds do we hear in web ads? What are the conditions and functions of sound in web ads? Moreover, the chapter proposes a theoretical framework in order to analyse the communicative functions of sound in web advertising. The main...... argument is that an understanding of the auditory dimensions in web advertising must include a reflection on the hypertextual settings of the web ad as well as a perspective on how users engage with web content....

  8. It sounds good!

    CERN Multimedia

    CERN Bulletin


    Both the atmosphere and we ourselves are hit by hundreds of particles every second and yet nobody has ever heard a sound coming from these processes. Like cosmic rays, particles interacting inside the detectors at the LHC do not make any noise…unless you've decided to use the ‘sonification’ technique, in which case you might even hear the Higgs boson sound like music. Screenshot of the first page of the "LHC sound" site. A group of particle physicists, composers, software developers and artists recently got involved in the ‘LHC sound’ project to make the particles at the LHC produce music. Yes…music! The ‘sonification’ technique converts data into sound. “In this way, if you implement the right software you can get really nice music out of the particle tracks”, says Lily Asquith, a member of the ATLAS collaboration and one of the initiators of the project. The ‘LHC...

  9. The Sounds of Sentences: Differentiating the Influence of Physical Sound, Sound Imagery, and Linguistically Implied Sounds on Physical Sound Processing. (United States)

    Dudschig, Carolin; Mackenzie, Ian Grant; Strozyk, Jessica; Kaup, Barbara; Leuthold, Hartmut


    Both the imagery literature and grounded models of language comprehension emphasize the tight coupling of high-level cognitive processes, such as forming a mental image of something or language understanding, and low-level sensorimotor processes in the brain. In an electrophysiological study, imagery and language processes were directly compared and the sensory associations of processing linguistically implied sounds or imagined sounds were investigated. Participants read sentences describing auditory events (e.g., "The dog barks"), heard a physical (environmental) sound, or had to imagine such a sound. We examined the influence of the 3 sound conditions (linguistic, physical, imagery) on subsequent physical sound processing. Event-related potential (ERP) difference waveforms indicated that in all 3 conditions, prime compatibility influenced physical sound processing. The earliest compatibility effect was observed in the physical condition, starting in the 80-110 ms time interval with a negative maximum over occipital electrode sites. In contrast, the linguistic and the imagery condition elicited compatibility effects starting in the 180-220 ms time window with a maximum over central electrode sites. In line with the ERPs, the analysis of the oscillatory activity showed that compatibility influenced early theta and alpha band power changes in the physical, but not in the linguistic and imagery, condition. These dissociations were further confirmed by dipole localization results showing a clear separation between the source of the compatibility effect in the physical sound condition (superior temporal area) and the source of the compatibility effect triggered by the linguistically implied sounds or the imagined sounds (inferior temporal area). Implications for grounded models of language understanding are discussed.

  10. Ecological sounds affect breath duration more than artificial sounds. (United States)

    Murgia, Mauro; Santoro, Ilaria; Tamburini, Giorgia; Prpic, Valter; Sors, Fabrizio; Galmonte, Alessandra; Agostini, Tiziano


    Previous research has demonstrated that auditory rhythms affect both movement and physiological functions. We hypothesized that the ecological sounds of human breathing can affect breathing more than artificial sounds of breathing, varying in tones for inspiration and expiration. To address this question, we monitored the breath duration of participants exposed to three conditions: (a) ecological sounds of breathing, (b) artificial sounds of breathing having equal temporal features as the ecological sounds, (c) no sounds (control). We found that participants' breath duration variability was reduced in the ecological sound condition, more than in the artificial sound condition. We suggest that ecological sounds captured the timing of breathing better than artificial sounds, guiding as a consequence participants' breathing. We interpreted our results according to the Theory of Event Coding, providing further support to its validity, and suggesting its possible extension in the domain of physiological functions which are both consciously and unconsciously controlled.

  11. A pulsed electron gun for the Plane Wave Transformer Linac

    CERN Document Server

    Mahadevan, S; Nandedkar, R V


    A pulsed diode electron gun delivering 500 mA current at 40 kV is described. The gun geometry is optimized using the Electron Trajectory Program EGUN at higher scaling factors by choosing the closest converging starting surface. The effect of an annular gap between cathode and focusing electrode on beam behaviour is compensated by using a suitable focusing electrode. The estimated perveance is 0.065 mu perv and the normalized emittance is within 5 pi mm mrad. The variation in current density at the cathode has been limited to within 10% across the face of the cathode. Salient features of the pulsed power supply and an insight of its interconnection with the gun are presented. The current measured at the Faraday cup is in agreement with the designed perveance.

  12. Longitudinal jitter analysis of linear accelerator electron gun

    CERN Document Server

    Mingshan, Liu; Iqbal, Munawar


    We present measurement and analyses of longitudinal timing jitter of Beijing Electron Positron Collider (BEPCII) linear accelerator electron gun. We simulated longitudinal jitter effect of the gun using PARMELA about beam performance including beam profile, average energy, energy spread, longitudinal phase of reference particle and XY emittance. The maximum percentage difference of the beam parameters are calculated to be; 100%, 13.27%, 42.24%, 7.79% and 65.01%, 86.81%, respectively due to which the bunching efficiency is reduced to 54%. The simulation results are in agreement with test and are helpful to optimize the beam parameters by tuning the trigger timing of the gun during the bunching process.

  13. Carrying guns in public: legal and public health implications. (United States)

    Vernick, Jon S


    In District of Columbia v. Heller, the U.S. Supreme Court ruled that the Second Amendment protects an individual's right to own handguns in the home for protection, invalidating a Washington, D.C. law banning most handgun possession. The Heller decision, however, provided lower courts with little guidance regarding how to judge the constitutionality of gun laws other than handgun bans. Nevertheless, lower courts have upheld the vast majority of federal, state, and local gun laws challenged since Heller. One area in which some lower courts have disagreed has been the constitutionality of laws regulating the ability to carry firearms in public. This issue may be the next to be addressed by the Supreme Court under its evolving Second Amendment jurisprudence. Courts should carefully consider the negative public health and safety implications of gun carrying in public as they weigh the constitutionality of these laws.

  14. Response of potato to drip and gun irrigation systems

    DEFF Research Database (Denmark)

    Zhenjiang, Zhou; Andersen, Mathias Neumann; Plauborg, Finn


    The objective of this study was to evaluate effects of different irrigation and N fertilization regimes by gun irrigation and drip-fertigation on potato production, and subsequently optimize the supply of water and N fertilizer to the growth condition of the specific season and minimize nitrate......-fertigation system (DFdsNds) and two gun irrigation systems (GIdsN120 and GIaN120) to display the differences on growth, yield and water use efficiency of potato. All treatments were irrigated according to model simulated soil water content. For fertilization all treatments received a basic dressing at planting of P......, K, Mg and micronutrients, and in addition 120 kg N/ha in the gun irrigated treatments and 36 kg N/ha in the drip-fertigated. For the latter, portion of 20 kg N/ha was applied whenever plant N concentration approached a critical value as simulated by the Daisy model. As a result differences in soil...

  15. Emittance Measurements of the SSRL Gun Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Michael; Clendenin, James; Fisher, Alan; Miller, Roger; Palmer, Dennis; Park, Sam; Schmerge, John; Weaver, Jim; Wiedemann, Helmut; Winick, Herman; Yeremian, Dian; /SLAC; Meyerhofer, David; Reis, David; /Rochester U.


    A photocathode RF gun test stand is under construction in the injector vault of the Stanford Synchrotron Radiation Laboratory at SLAC. The goal of this facility is to produce an electron beam with a normalized emittance of 1-3[mm-mr], a longitudinal bunch duration of the order of 10[ps] FWHM and approximately 1[nC] of charge per bunch. The beam will be generated from a laser driven copper photocathode RF gun developed in collaboration with BNL, LBL and UCLA. The 3-5[MeV] beam from the gun will be accelerated using a SLAC three meter S-band accelerator section. The emittance of the electron beam will be measured through the use of quadrupole scans with phosphor screens and also a wire scanner. The details of the experimental setup will be discussed, and first measurements will be presented and compared with results from PARMELA simulations.

  16. Rf Gun with High-Current Density Field Emission Cathode

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield


    High current-density field emission from an array of carbon nanotubes, with field-emission-transistor control, and with secondary electron channel multiplication in a ceramic facing structure, have been combined in a cold cathode for rf guns and diode guns. Electrodynamic and space-charge flow simulations were conducted to specify the cathode configuration and range of emission current density from the field emission cold cathode. Design of this cathode has been made for installation and testing in an existing S-band 2-1/2 cell rf gun. With emission control and modulation, and with current density in the range of 0.1-1 kA/cm2, this cathode could provide performance and long-life not enjoyed by other currently-available cathodes

  17. The challenge of gun control for mental health advocates. (United States)

    Pandya, Anand


    Mass shootings, such as the 2012 Newtown massacre, have repeatedly led to political discourse about limiting access to guns for individuals with serious mental illness. Although the political climate after such tragic events poses a considerable challenge to mental health advocates who wish to minimize unsympathetic portrayals of those with mental illness, such media attention may be a rare opportunity to focus attention on risks of victimization of those with serious mental illness and barriers to obtaining psychiatric care. Current federal gun control laws may discourage individuals from seeking psychiatric treatment and describe individuals with mental illness using anachronistic, imprecise, and gratuitously stigmatizing language. This article lays out potential talking points that may be useful after future gun violence.

  18. Dual Feed RF Gun Design for the LCLS

    CERN Document Server

    Xiao, Liling; Dowell, David; Li, Zenghai; Limborg-Deprey, Cecile; Schmerge, John


    In order to remove the dipole field introduced by the coupler in existing S-band BNL/SLAC/UCLA 1.6 cell rf gun, a dual feed design for the LCLS RF gun is proposed together with several significant changes. The improvements include adopting Z-coupling instead of ?-coupling for easier machining and reducing heating, increasing the 0-and ?-mode separation from 3.4 to 15 MHz to reduce the amplitude of the 0 mode, incorporating race-track cavity shape to minimize the quadruple fields, increased cooling for operation at 120Hz and other small changes to improve performance and diagnostic capabilities. The new design has been modeled with the parallel finite element eigenmode solver Omega3P to provide the desired RF parameters and to generate the gun cavity dimensions needed for fabrication.

  19. Gene gun delivery systems for cancer vaccine approaches. (United States)

    Aravindaram, Kandan; Yang, Ning Sun


    Gene-based immunization with transgenic DNA vectors expressing tumor-associated antigens (TAA), cytokines, or chemokines, alone or in combination, provides an attractive approach to increase the cytotoxic T cell immunity against various cancer diseases. With this consideration, particle-mediated or gene gun technology has been developed as a nonviral method for gene transfer into various mammalian tissues. It has been shown to induce both humoral and cell-mediated immune responses in both small and large experimental animals. A broad range of somatic cell types, including primary cultures and established cell lines, has been successfully transfected ex vivo or in vitro by gene gun technology, either as suspension or adherent cultures. Here, we show that protocols and techniques for use in gene gun-mediated transgene delivery system for skin vaccination against melanoma using tumor-associated antigen (TAA) human gpl00 and reporter gene assays as experimental systems.

  20. Characterization of a Dielectric Barrier Plasma Gun Discharging at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guang-Qiu; GE Yuan-Jing; ZHANG Yue-Fei; CHEN Guang-Liang


    @@ We develop a plasma gun based on dielectric barrier discharge and working at atmospheric pressure. A theoretical model to predict the gun discharge voltage is built, which is in agreement with the experimental results. After investigating the characterization of discharging gun and utilizing it for polymerization, we find that the gun can be used as a source to generate a stable uniform plasma for different plasma-processing technologies.

  1. The Textile Form of Sound

    DEFF Research Database (Denmark)

    Bendixen, Cecilie

    Sound is a part of architecture, and sound is complex. Upon this, sound is invisible. How is it then possible to design visual objects that interact with the sound? This paper addresses the problem of how to get access to the complexity of sound and how to make textile material revealing the form...... three-dimensional geometries of interfering spheres are created. Textiles are generally a very good sound dampening material. To dampen the sound most effective it should be placed where the sound energy is highest. To find these invisible spots of energy and to reveal the geometry of them, two...... experiments were carried out. One experiment was done in a laboratory with a sound measure instrument and textiles arranged in different positions and shapes. Here the high energy spots were located. The other experiment is ongoing and is an investigation of how textiles can take the shape of the sound...

  2. Proceedings of the Second International Congress on Recent Developments in Air- and Structure-Borne Sound and Vibration (2nd) Held in Auburn University, Alabama on 4-6 March 1992. Volume 1 (United States)


    Campbell, W.A. and Mariott , R.S., "Outgassing Data for Selecting Spacecraft Materials," NASA Reforepce Publication 1124, Revised. [51 Yiu, Y.C., Austin...designated conditions. INTRODUCTION In Japan, there is an increasing demand for better sound insulation in apartment or hotel buildings. It is also

  3. The Army Needs a Strategic Armored Gun System--Now (United States)


    the AGS ROC. IVECO- Fiat, The Italian firm o4 IVECO- Fiat has proposed three variants as candidates for the AGS! - The Centauro 9x8 wheeled light...armored vehicle with OTO Melana, i05mm turret. - The Centauro SxO with the Cadillac-Gage 105mm turret mounting the Royal Ordnance L-7 105mm gun. - The... Centauro 6x6 with the LAV-i10mm turret and EX-35 gun. The three systems cannot meet many of the AGE requirements# primarily weightp since the heaviest

  4. Beta II plasma-gun mechanical design and construction

    Energy Technology Data Exchange (ETDEWEB)

    Pedrotti, L.; Deis, G.; Wong, R.; Calderon, M.; Chargin, A.; Garner, D.


    The magnetized coaxial plasma gun (located on the east end of the Beta II facility at the Lawrence Livermore Laboratory) will be used to test a new method of initiating a field reversed mirror plasma. The field-reversed mirror is expected to improve the mirror-fusion reactor by enhancing the ratio of fusion power to injected power. This paper concentrates on the mechanical design and construction of the magnetized coaxial plasma gun and also discusses the diagnostic devices necessary to demonstrate the formation of field-reversed rings.

  5. Analysis on Venting Time of Rarefaction Wave Gun

    Institute of Scientific and Technical Information of China (English)

    WANG Ying-ze; ZHANG Xiao-bing; YUAN Yax-iong


    Based on the operation principle of rarefaction wave gun, the selection and calculation methods for venting opportune moment are invastigated. Considering property of the rarefaction wave, taking the center of muzzle section as initial calculation point, supposing that at the moment projectile arrives to the muzzle, the rarefaction wave arrives to the base of projectile, the rarefaction wave velocity along the barrel can be obtained by fitting calculation of the interior ballis-tic data of the same closed gun and reverse deduction. And then, the optimal venting time can be found out correctly based on the rarefaction wave velocity.

  6. Internal Ballistics of High Velocity Special Purpose Guns

    Directory of Open Access Journals (Sweden)

    V. K. Gupta


    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.

  7. Plasma-filled diode based on the coaxial gun

    Energy Technology Data Exchange (ETDEWEB)

    Zherlitsyn, A. A.; Kovalchuk, B. M.; Pedin, N. N. [Institute of High Current Electronics, 2/3 Academichesky Avenue, 634055 Tomsk (Russian Federation)


    The paper presents the results of studies of a coaxial gun for a plasma-filled electron diode. Effects of the discharge channel diameter and gun current on characteristics of the plasma and pulse generated in the diode were investigated. The electron beam with maximum energy of {>=}1 MeV at the current of Almost-Equal-To 100 kA was obtained in the experiments with a plasma-filled diode. The energy of Almost-Equal-To 5 kJ with the peak power of {>=}100 GW dissipated in the diode.

  8. Plasma-filled diode based on the coaxial gun (United States)

    Zherlitsyn, A. A.; Kovalchuk, B. M.; Pedin, N. N.


    The paper presents the results of studies of a coaxial gun for a plasma-filled electron diode. Effects of the discharge channel diameter and gun current on characteristics of the plasma and pulse generated in the diode were investigated. The electron beam with maximum energy of ≥1 MeV at the current of ≈100 kA was obtained in the experiments with a plasma-filled diode. The energy of ≈5 kJ with the peak power of ≥100 GW dissipated in the diode.

  9. Plasma-filled diode based on the coaxial gun. (United States)

    Zherlitsyn, A A; Kovalchuk, B M; Pedin, N N


    The paper presents the results of studies of a coaxial gun for a plasma-filled electron diode. Effects of the discharge channel diameter and gun current on characteristics of the plasma and pulse generated in the diode were investigated. The electron beam with maximum energy of ≥1 MeV at the current of ≈100 kA was obtained in the experiments with a plasma-filled diode. The energy of ≈5 kJ with the peak power of ≥100 GW dissipated in the diode.

  10. A novel surface-repairing technique for gun bore

    Institute of Scientific and Technical Information of China (English)

    SU Bing; YU Xu-dong; WU Bin; WANG Cheng-tao


    A novel surface-repairing technique for gun bore was investigated, which was combined with the merits such as anti-erosion wear, damage-repairing, and etc. It was accomplished by adhering a special rare earth nanocom posite evenly to the micro-surface of gun bore. The effectiveness of this technique was approved by the target-firing using a domestic automatic rifle with chromium-coated bore. Its characteristics were discussed based on the surface analyses of the rifle bore by secondary ion mass spectrometry(SIMS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis.

  11. The system of RF beam control for electron gun (United States)

    Barnyakov, A. M.; Chernousov, Yu. D.; Ivannikov, V. I.; Levichev, A. E.; Shebolaev, I. V.


    The system of RF control of three-electrode electron gun current is described. It consists of a source of microwave signal, coaxial line, coaxial RF switch and RF antenna lead. The system allows one to get the electron beam in the form of bunches with the frequency of the accelerating section to achieve the capture of particles in the acceleration mode close to 100%. The results of calculation and analysis of the elements of the system are presented. Characteristics of the devices are obtained experimentally. The results of using RF control in three-electrode electron gun at electron linear accelerator are described.

  12. Gun laws and the involuntarily committed: a California road map. (United States)

    Zahedi, Sohrab; Burchuk, Robert; Stone, David C; Kopelowicz, Alex


    The 2007 incident at Virginia Tech brought the question of gun ownership by the mentally ill to the forefront of public attention. Moreover, it underscored the potentially devastating consequences of the imperfect connection between federal and state laws that apply to the right of gun ownership by a psychiatric patient. The laws are complex, and, as demonstrated in this article, conflicting. We present a case report of an involuntarily committed patient in the state of California, and discuss details of state and federal laws that applied to him.

  13. Individual-Level Risk Factors for Gun Victimization in a Sample of Probationers (United States)

    Wells, William; Chermak, Steven


    Interventions aimed at preventing the important problem of gun injuries could be improved with an understanding of whether there are unique factors that place individuals at an increased risk of gun victimization. Much remains to be known about the victims of gun violence. The purpose of this article is to assess whether there are individual-level…

  14. Electron-beam-controlled laser with a grid-controlled electron gun

    Energy Technology Data Exchange (ETDEWEB)

    Avanesyan, V.S.; Dutov, A.I.; Lakhno, Y.V.; Malkhov, L.N.


    An experimental investigation was made of an electron-beam-controlled carbon dioxide laser with an electron gun in which the beam current was modulated by a control grid. The design features of the electron gun and laser are described and their performance is reported. Observations of instabilities of the electron beam in the gun are reported and methods for eliminating them are suggested.

  15. 78 FR 55014 - Machine Guns, Destructive Devices and Certain Other Firearms; Background Checks for Responsible... (United States)


    ... Bureau of Alcohol, Tobacco, Firearms, and Explosives 27 CFR Part 479 RIN 1140-AA43 Machine Guns... the dealing in, machine guns, destructive devices, and certain other firearms. \\1\\ Provisions of the... section 922(g)(5)(B) of the Gun Control Act, 18 U.S.C. 922(g)(5)(B), it generally is unlawful for...

  16. 27 CFR 479.105 - Transfer and possession of machine guns. (United States)


    ... machine guns. 479.105 Section 479.105 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND EXPLOSIVES, DEPARTMENT OF JUSTICE FIREARMS AND AMMUNITION MACHINE GUNS, DESTRUCTIVE DEVICES, AND CERTAIN OTHER FIREARMS Registration and Identification of Firearms Machine Guns § 479.105...

  17. 27 CFR 478.36 - Transfer or possession of machine guns. (United States)


    ... machine guns. 478.36 Section 478.36 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... Administrative and Miscellaneous Provisions § 478.36 Transfer or possession of machine guns. No person shall transfer or possess a machine gun except: (a) A transfer to or by, or possession by or under the...

  18. 78 FR 4295 - Engaging in Public Health Research on the Causes and Prevention of Gun Violence (United States)


    ... Prevention of Gun Violence Memorandum for the Secretary of Health and Human Services In addition to being a law enforcement challenge, gun violence is also a serious public health issue that affects thousands... strides can be made by assessing the causes of gun violence and the successful efforts in place...

  19. Sources of guns to dangerous people: what we learn by asking them. (United States)

    Cook, Philip J; Parker, Susan T; Pollack, Harold A


    Gun violence exacts a lethal toll on public health. This paper focuses on reducing access to firearms by dangerous offenders, contributing original empirical data on the gun transactions that arm offenders in Chicago. Conducted in the fall of 2013, analysis of an open-ended survey of 99 inmates of Cook County Jail focuses on a subset of violence-prone individuals with the goal of improving law enforcement actions. Among our principal findings: *Our respondents (adult offenders living in Chicago or nearby) obtain most of their guns from their social network of personal connections. Rarely is the proximate source either direct purchase from a gun store, or theft. *Only about 60% of guns in the possession of respondents were obtained by purchase or trade. Other common arrangements include sharing guns and holding guns for others. *About one in seven respondents report selling guns, but in only a few cases as a regular source of income. *Gangs continue to play some role in Chicago in organizing gun buys and in distributing guns to members as needed. *The Chicago Police Department has a considerable effect on the workings of the underground gun market through deterrence. Transactions with strangers and less-trusted associates are limited by concerns over arrest risk (if the buyer should happen to be an undercover officer or a snitch), and about being caught with a "dirty" gun (one that has been fired in a crime).

  20. 27 CFR 70.442 - Taxes relating to machine guns, destructive devices, and certain other firearms. (United States)


    ... guns, destructive devices, and certain other firearms. 70.442 Section 70.442 Alcohol, Tobacco Products... relating to machine guns, destructive devices, and certain other firearms. Part 179 of title 27 CFR... importers of and dealers in, machine guns, destructive devices, and certain other types of firearms,...

  1. Production of Dioxins and Furans from the Burning of Excess Gun Propellant (United States)


    Chemical composition of M1 gun propellant Constituents Proportions (weight/weight %) Nitrocellulose 85 ± 2 2,4-dinitrotoluene 10 ± 2...Production of dioxins and furans from the burning of excess gun propellant Isabelle Poulin Sonia Thiboutot Sylvie Brochu DRDC Valcartier Defence...excess gun propellant Isabelle Poulin Sonia Thiboutot Sylvie Brochu DRDC Valcartier Defence R&D Canada – Valcartier

  2. To Keep and Bear Arms: Gun Control and the Second Amendment. Teacher's Guide. (United States)

    Edwards, Amy N.; Walker, Tim

    This teacher's guide is designed to accompany the two-part videotape "To Keep and Bear Arms: Gun Control and the Second Amendment." The videotape and teacher's guide should help students to: (1) understand the history of the Second Amendment; (2) examine how guns and gun control laws affect people's lives; (3) compare and contrast the many…

  3. Crime, Culture Conflict, and the Sources of Support for Gun Control. (United States)

    Kleck, Gary


    Questions whether attitudes towards gun control are influenced primarily by exposure to high crime rates, prior victimization, and fear of crime, or result from membership in social groups hostile to gun ownership. Maintains that support for gun control is more a product of culture conflict than a response to crime. (MJP)

  4. Revisiting the Gun Ownership and Violence Link; a multi- level analysis of victimisation survey data.

    NARCIS (Netherlands)

    van Kesteren, J.N.


    The link between gun ownership victimisation by violent crime remains one of the most contested issues in criminology. Some authors claim that high gun availability facilitates serious violence. Others claim that gun ownership prevents crime. This article revisits these issues using individual and a

  5. Meteor fireball sounds identified (United States)

    Keay, Colin


    Sounds heard simultaneously with the flight of large meteor fireballs are electrical in origin. Confirmation that Extra/Very Low Frequency (ELF/VLF) electromagnetic radiation is produced by the fireball was obtained by Japanese researchers. Although the generation mechanism is not fully understood, studies of the Meteorite Observation and Recovery Project (MORP) and other fireball data indicate that interaction with the atmosphere is definitely responsible and the cut-off magnitude of -9 found for sustained electrophonic sounds is supported by theory. Brief bursts of ELF/VLF radiation may accompany flares or explosions of smaller fireballs, producing transient sounds near favorably placed observers. Laboratory studies show that mundane physical objects can respond to electrical excitation and produce audible sounds. Reports of electrophonic sounds should no longer be discarded. A catalog of over 300 reports relating to electrophonic phenomena associated with meteor fireballs, aurorae, and lightning was assembled. Many other reports have been cataloged in Russian. These may assist the full solution of the similar long-standing and contentious mystery of audible auroral displays.

  6. Stationary waves in tubes and the speed of sound (United States)

    Kasper, Lutz; Vogt, Patrik; Strohmeyer, Christine


    The opportunity to plot oscillograms and frequency spectra with smartphones creates many options for experiments in acoustics, including several that have been described in this column.1-3 The activities presented in this paper are intended to complement these applications, and include an approach to determine sound velocity in air by using standard drain pipes4 and an outline of an investigation of the temperature dependency of the speed of sound.

  7. Sound & The Society

    DEFF Research Database (Denmark)

    Schulze, Holger


    How are those sounds you hear right now socially constructed and evaluated, how are they architecturally conceptualized and how dependant on urban planning, industrial developments and political decisions are they really? How is your ability to hear intertwined with social interactions and their ...... and their professional design? And how is listening and sounding a deeply social activity – constructing our way of living together in cities as well as in apartment houses? A radio feature with Nina Backmann, Jochen Bonz, Stefan Krebs, Esther Schelander & Holger Schulze......How are those sounds you hear right now socially constructed and evaluated, how are they architecturally conceptualized and how dependant on urban planning, industrial developments and political decisions are they really? How is your ability to hear intertwined with social interactions...

  8. A comparison of two different sound intensity measurement principles

    DEFF Research Database (Denmark)

    Jacobsen, Finn; de Bree, Hans-Elias


    The dominating method of measuring sound intensity in air is based on the combination of two pressure microphones. However, a sound intensity probe that combines an acoustic particle velocity transducer with a pressure microphone has recently become available. This paper examines, discusses......, and compares the two measurement principles with particular regard to the sources of error in sound power determination. It is shown that the phase calibration of intensity probes that combine different transducers is very critical below 500 Hz if the measurement surface is very close to the source under test...

  9. Handbook for sound engineers

    CERN Document Server

    Ballou, Glen


    Handbook for Sound Engineers is the most comprehensive reference available for audio engineers. All audio topics are explored: if you work on anything related to audio you should not be without this book! The 4th edition of this trusted reference has been updated to reflect changes in the industry since the publication of the 3rd edition in 2002 -- including new technologies like software-based recording systems such as Pro Tools and Sound Forge; digital recording using MP3, wave files and others; mobile audio devices such as iPods and MP3 players. Over 40 topic

  10. Urban Sound Interfaces

    DEFF Research Database (Denmark)

    Breinbjerg, Morten


    This paper draws on the theories of Michel de Certeau and Gaston Bachelard to discuss how media architecture, in the form of urban sound interfaces, can help us perceive the complexity of the spaces we inhabit, by exploring the history and the narratives of the places in which we live. In this pa....... In this paper, three sound works are discussed in relation to the iPod, which is considered as a more private way to explore urban environments, and as a way to control the individual perception of urban spaces....

  11. Sound Art Situations

    DEFF Research Database (Denmark)

    Samson, Kristine; Krogh Groth, Sanne


    This article is an analysis of two sound art performances that took place June 2015 in outdoor public spaces in the social housing area Urbanplanen in Copenhagen, Denmark. The two performances were On the production of a poor acoustics by Brandon LaBelle and Green Interactive Biofeedback Environm......This article is an analysis of two sound art performances that took place June 2015 in outdoor public spaces in the social housing area Urbanplanen in Copenhagen, Denmark. The two performances were On the production of a poor acoustics by Brandon LaBelle and Green Interactive Biofeedback...

  12. Sound for digital video

    CERN Document Server

    Holman, Tomlinson


    Achieve professional quality sound on a limited budget! Harness all new, Hollywood style audio techniques to bring your independent film and video productions to the next level.In Sound for Digital Video, Second Edition industry experts Tomlinson Holman and Arthur Baum give you the tools and knowledge to apply recent advances in audio capture, video recording, editing workflow, and mixing to your own film or video with stunning results. This fresh edition is chockfull of techniques, tricks, and workflow secrets that you can apply to your own projects from preproduction

  13. Sound & The Senses

    DEFF Research Database (Denmark)

    Schulze, Holger


    How are those sounds you hear right now technically generated and post-produced, how are they aesthetically conceptualized and how culturally dependant are they really? How is your ability to hear intertwined with all the other senses and their cultural, biographical and technological constructio...... over time? And how is listening and sounding a deeply social activity – constructing our way of living together in cities as well as in apartment houses? A radio feature with Jonathan Sterne, AGF a.k.a Antye Greie, Jens Gerrit Papenburg & Holger Schulze....

  14. Sound & The Studio

    DEFF Research Database (Denmark)

    Schulze, Holger


    How are those sounds you hear right now technically generated and post-produced, how are they aesthetically conceptualized and how culturally dependant are they really? How is your ability to hear intertwined with all the other senses and their cultural, biographical and technological constructio...... over time? And how is listening and sounding a deeply social activity – constructing our way of living together in cities as well as in apartment houses? A radio feature with David Toop, Simon Zagorski-Thomas, Paul Théberge, Maria Hanáček & Holger Schulze....

  15. Chromium Elimination and Cannon Life Extension for Gun Tubes (United States)


    Ta is refractory, ductile, strong, relatively corrosion and erosion resistant , Minimal thermal variation W adds hardness, strength...completely soluble in Ta MO adds hardness, corrosion and embrittlement resistance properties, substitute for tungsten to increase hardness is an...erosion- resistant chrome cobalt alloy matrix with 15% tungsten. Stellite is used as M60 machine gun barrel liner. Tantalum Cobalt Tungsten

  16. A Brief Journey Through the History of Gun Propulsion (United States)


    Simplified schematic of electromagnetic gun – coilgun concept. ...............................17 Figure 23. Simplified schematic of electromagnetic...benefited from the use of rigid case assemblies. Performance has been the paramount issue , and the quest for maximizing propellant energy, loading... coilgun concept. Prime Power Pulsed Power Supply Projectile Drive Coils 18 Figure 23. Simplified schematic of

  17. Configuration optimization of high velocity arc spraying gun

    Institute of Scientific and Technical Information of China (English)

    CHEN Yong-xiong; ZHU Zi-xin; LIU Yan; XU Bin-shi


    In order to improve the in-flight characteristics of the atomizing droplets during high velocity wire arc spraying (HVAS), some changes have been operated on the original design of the HVAS gun configuration. A comparative study was carried out to investigate the microstructure and properties of the coatings produced by the original design spraying gun and the modified one, using 3Cr13 wires of 3 mm in diameter. The characteristics of their jets were examined during spraying. The results indicate that, the included angle between the two wires and the distance from the nozzle to the meeting point of the two vires may have a strong influence on the characteristics of the in-flight droplets and then the coatings. The jet divergence is found to be lower than that of the original one (about 12° against 25°). By modified gun, the adhesion strength, the microhardness and porosity of the coating deposited by modified gun are increased by 39% and 9% respectively. And the porosity of the coatings is decreased by 57%.

  18. Adolescents' Views of Guns in a High-Violence Community (United States)

    Black, Sally; Hausman, Alice


    Firearms account for the majority of deaths among young Black men in America. This article presents a qualitative investigation of youth temptations, emotional reactions, and subsequent behavior with respect to guns. Twenty-three youth enrolled in a community-based firearm reduction program have participated in interviews on retrospective…

  19. Terahertz-driven, all-optical electron gun

    CERN Document Server

    Huang, W Ronny; Wu, Xiaojun; Cankaya, Huseyin; Calendron, Anne-Laure; Ravi, Koustuban; Zhang, Dongfang; Nanni, Emilio A; Hong, Kyung-Han; Kärtner, Franz X


    Ultrashort electron beams with narrow energy spread, high charge, and low jitter are essential for resolving phase transitions in metals, semiconductors, and molecular crystals. These semirelativistic beams, produced by phototriggered electron guns, are also injected into accelerators for x-ray light sources. The achievable resolution of these time-resolved electron diffraction or x-ray experiments has been hindered by surface field and timing jitter limitations in conventional RF guns, which thus far are 96 fs, respectively. A gun driven by optically-generated single-cycle THz pulses provides a practical solution to enable not only GV/m surface fields but also absolute timing stability, since the pulses are generated by the same laser as the phototrigger. Here, we demonstrate an all-optical THz gun yielding peak electron energies approaching 1 keV, accelerated by 300 MV/m THz fields in a novel micron-scale waveguide structure. We also achieve quasimonoenergetic, sub-keV bunches with 32 fC of charge, which ca...

  20. More Fun and Curiosity with Magnetic Guns in the Classroom (United States)

    Chittasirinuwat, O.; Kruatong, T.; Paosawatyanyong, B.


    The magnetic gun was chosen as a hands-on activity for our high school students. When conducting this activity in the classroom, we found some interesting points were raised following difficulties encountered by the students. Some students proposed that during the collision, the magnet changed its pole then it pushed the last ball out of the…

  1. Community College Faculty: Attitudes toward Guns on Campus (United States)

    Dahl, Patricia P.; Bonham, Gene, Jr.; Reddington, Frances P.


    This exploratory research surveyed faculty who instruct in community colleges from 18 states about their attitudes toward the concealed carry gun policies that allow appropriately licensed citizens to carry a handgun in public places such as college campuses. Building upon previous research involving 4-year institutions, we surveyed 1,889…

  2. Guns on Campus: A Current Debate. E-Fact Sheet (United States)

    Higher Education Center for Alcohol, Drug Abuse, and Violence Prevention, 2010


    Almost all U.S. college campuses ban concealed weapons. But in the aftermath of the tragic shooting deaths at Virginia Tech in 2007, the debate on whether guns should be permitted at colleges and universities has intensified. Dozens of states have considered proposals to lift bans on concealed weapons at colleges and universities, but so far none…

  3. Modeling Gun Dynamics with Three-Dimensional Beam Elements (United States)


    34 Sixth U.S. Army Symposium on Gun Dynamics, 14-17 May, 1990. Shames, Irving, and Clive Dym. Energy and Finite Element Methods in Structural Mechanics. New...Group ATIN: Mr. G. Barker Mr. A. E. Chambers Mr. J. Hoyle Mr. N. D. Manners Mr. S. E. Powell Dr. D. N. Bulman Shrivenham, Swindon, Wilts SN6 8LA

  4. High perveance electron gun for the electron cooling system

    CERN Document Server

    Korotaev, Yu V; Petrov, A; Sidorin, A; Smirnov, A; Syresin, E M; Titkova, I


    The cooling time in the electron cooling system is inversely proportional to the beam current. To obtain high current of the electron beam the control electrode of the gun is provided with a positive potential and an electrostatic trap for secondary electrons appears inside the electron gun. This leads to a decrease in the gun perveance. To avoid this problem, the adiabatic high perveance electron gun with the clearing control electrode is designed in JINR (J. Bosser, Y. Korotaev, I. Meshkov, E. Syresin et al., Nucl. Instr. and Meth. A 391 (1996) 103. Yu. Korotaev, I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, The generation of electron beams with perveance of 3-6 mu A/V sup 3 sup / sup 2 , Proceedings of SCHEF'99). The clearing control electrode has a transverse electric field, which clears secondary electrons. Computer simulations of the potential map were made with RELAX3D computer code (C.J. Kost, F.W. Jones, RELAX3D User's Guide and References Manual).

  5. Proposed Federal Gun-Control Amendment. Student Forum. (United States)

    Mertz, Gayle; Mertz, David


    Presents an outline for a student-run forum on a proposed federal gun control amendment. Procedures include mandatory reading assignments and researching the issue. Students role-play fictional representative characters and later facilitate discussions. Concludes with a vote on the amendment. (MJP)

  6. Note: Thermal analysis of the long line source electron gun (United States)

    Iqbal, M.; Wasy, A.; Lodhi, M. A. K.


    We performed thermal analysis for our previously reported [M. Iqbal, K. Masood, M. Rafiq, M. A. Chaudhry, and F. Aleem, Rev. Sci. Instrum. 74, 4616 (2003), 10.1063/1.1614852], long linear filament electron gun assembly using ANSYS software. The source was set under a thermal load of 3000 °C, to evaluate temperature distribution, thermal strain, and heat flux at various components of the gun. We calculated the maximum heat flux (9.0 W/mm2) that produced a thermal strain of 0.05 at the focusing electrodes. However, the minimum value of the heat flux (0.3 W/mm2) was at the anode electrodes which correspond to a negligible thermal strain. The gun was validated experimentally showing a uniform cross section of the beam at the molybdenum work plate comparable to the size of the filament. Our experimental and theoretical results are in agreement. The gun had been in continuous operation for several hours at high temperatures without any thermal run-out.

  7. First beam commissioning at BNL ERL SRF Gun

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Altinbas, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy; Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy; Deonarine, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; DeSanto, L. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gassner, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Gupta, R. C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hahn, H. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hammons, L. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Ho, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Jamilkoski, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Kankiya, P. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Kayran, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Kellerman, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Laloudakis, N. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Lambiase, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Liaw, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy; Mahler, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Masi, L. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; McIntyre, G. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Miller, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Philips, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Seda, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Sheehy, B. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Rao, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Steszyn, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tallerico, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tuozollo, J. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Wang, E. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Weiss, D. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Wiliniski, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.


    The 704 MHz SRF gun successfully generated the first photoemission beam in November of 2014. The configurations of the test and the sub-systems are described.The latest results of SRF commissioning, including the cavity performance, cathode QE measurements, beam current/energy measurements, are presented in the paper.

  8. Algorithm design for grip-pattern verification in smart gun

    NARCIS (Netherlands)

    Shang, X.; Veldhuis, R.N.J.; Bazen, A.M.; Ganzevoort, W.P.T.


    The Secure Grip project1 focuses on the development of a hand-grip pattern recognition system, as part of the smart gun. Its target customer is the police. To explore the authentication performance of this system, we collected data from a group of police officers, and made authentication simulations

  9. Registration of hand-grip pattern in smart gun

    NARCIS (Netherlands)

    Shang, X.; Veldhuis, R.N.J.


    Secure Grip1 focuses on the development of a hand-grip pattern recognition system, as part of a smart gun. It is intended for use by the police. We collected the hand-grip data from police officers in three sessions in a row with time intervals in between. If data for training and testing come from

  10. Development of biopsy gun for aspiration and drug injection. (United States)

    Kang, Hyun Guy; Cho, Sung Ho; Cho, Chang Nho; Kim, Kwang Gi


    Tumor samples are required for pathological examinations, and different instruments are generally used to obtain samples of different types of tumors. Among the many methods available for obtaining tumor tissues, gun biopsy is widely used because it is much simpler than incisional biopsy and can collect many more samples than aspiration biopsy. However, conventional biopsy guns cannot simultaneously perform biopsy aspiration, bleeding prevention, and marker injection. In this study, we developed a biopsy gun that can simultaneously perform biopsy aspiration and sample collection, in addition to injecting a styptic agent and marker to prevent bleeding and contamination in the biopsy track. We then used a prototype to evaluate the feasibility of the developed device. The collectable sample size was also assessed. Performance of the biopsy aspiration feature was also evaluated, including the maximum aspiration viscosity. Finally, we tested the maximum amount of drug that can be injected. We found that the biopsy gun developed here is an alternative tool for biopsy collection with improved procedure safety and diagnostic accuracy.

  11. Sound Symbolism in Basic Vocabulary

    Directory of Open Access Journals (Sweden)

    Søren Wichmann


    Full Text Available The relationship between meanings of words and their sound shapes is to a large extent arbitrary, but it is well known that languages exhibit sound symbolism effects violating arbitrariness. Evidence for sound symbolism is typically anecdotal, however. Here we present a systematic approach. Using a selection of basic vocabulary in nearly one half of the world’s languages we find commonalities among sound shapes for words referring to same concepts. These are interpreted as due to sound symbolism. Studying the effects of sound symbolism cross-linguistically is of key importance for the understanding of language evolution.

  12. Design of a high repetition rate S-band photocathode gun (United States)

    Han, Jang-Hui; Cox, Matthew; Huang, Houcheng; Pande, Shivaji


    Photocathode RF guns have been developed in many laboratories for generating high quality electron beams for free-electron lasers based on linear accelerators. Such guns can generate electron beams with an exceptionally high peak current as well as a small transverse emittance. Their applications have been recently expanded for ultrafast electron diffraction, coherent terahertz radiation, and X-ray or γ-ray radiation by Compton scattering. In this paper, we design an S-band normal-conducting gun with capabilities of high quality beam generation and high repetition rate operation. The RF design and thermal analysis of the gun cavity and coupler are introduced. Optimal position of the gun focusing solenoid for low emittance beam generation is found by performing particle tracking simulations. Then, the gun system is designed to be able to afford the optimal solenoid position. The cooling-water channel surrounding the gun cavity and coupler is designed and analyzed numerically. The pressure in the gun is simulated with a vacuum model containing the detailed inner structure of the gun. An injector for a free-electron laser application is designed by using this gun and the beam dynamics simulation is shown. A cold test with a prototype gun for confirmation of the RF design is reported.

  13. Analysis of magnetically immersed electron guns with non-adiabatic fields (United States)

    Pikin, Alexander; Alessi, James G.; Beebe, Edward N.; Raparia, Deepak; Ritter, John


    Electron diode guns, which have strongly varying magnetic or electric fields in a cathode-anode gap, were investigated in order to generate laminar electron beams with high current density using magnetically immersed guns. By creating a strongly varying radial electric field in a cathode-anode gap of the electron gun, it was demonstrated that the optical properties of the gun can be significantly altered, which allows the generation of a laminar, high-current electron beam with relatively low magnetic field on the cathode. The relatively high magnetic compression of the electron beam achieved by this method is important for producing electron beams with high current density. A similar result can be obtained by inducing a strong variation of the magnetic field in a cathode-anode gap. It was observed that creating a dip in the axial magnetic field in the cathode-anode gap of an adiabatic electron gun has an optical effect similar to guns with strong variation of radial electric field. By analyzing the electron trajectories angles and presenting the results in a gun performance map, different geometries of magnetically immersed electron guns with non-adiabatic fields are compared with each other and with a more traditional adiabatic electron gun. Some advantages and limitations of guns with non-adiabatic fields are outlined. The tests' results of a non-adiabatic electron gun with modified magnetic field are presented.

  14. American preferences for “smart” guns versus traditional weapons: Results from a nationwide survey

    Directory of Open Access Journals (Sweden)

    Lacey Nicole Wallace


    Full Text Available This study examines Americans' preferences regarding smart guns. The study builds on prior research by including previously unexamined factors, specifically victimization and comfort sharing gun ownership status with a doctor. Further, this study examines differences in preference patterns among gun owners and non-owners. Data were obtained from a nationwide online survey with 524 respondents in February 2016. The study finds that, among non-owners, older respondents and those with pro-gun attitudes are less likely to prefer smart guns to traditional firearms. Among gun owners, those with moderate political views, those with a history of victimization, and those residing in the Northeast are all more likely to prefer smart guns. Males and those with pro-gun attitudes are less likely to prefer smart guns. Education, income, race, marital status, presence of children in the home, and comfort discussing gun ownership with a doctor had no significant association with smart gun preference. Practical implications of these findings are discussed.

  15. New Gas Gun Helping Scientists Better Understand Plutonium Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Hazi, A


    One of the most daunting scientific and engineering challenges today is ensuring the safety and reliability of the nation's nuclear arsenal. To effectively meet that challenge, scientists need better data showing how plutonium, a key component of nuclear warheads, behaves under extreme pressures and temperatures. On July 8, 2003, Lawrence Livermore researchers performed the inaugural experiment of a 30-meter-long, two-stage gas gun designed to obtain those data. The results from a continuing stream of successful experiments on the gas gun are strengthening scientists' ability to ensure that the nation's nuclear stockpile is safe and reliable. The JASPER (Joint Actinide Shock Physics Experimental Research) Facility at the Department of Energy's (DOE's) Nevada Test Site (NTS) is home to the two-stage gas gun. In the gun's first test, an unqualified success, Livermore scientists fired a projectile weighing 28.6 grams and traveling about 5.21 kilometers per second when it impacted an extremely small (about 30-gram) plutonium target. This experiment marked the culmination of years of effort in facility construction, gun installation, system integration, design reviews, and federal authorizations required to bring the experimental facility online. Ongoing experiments have drawn enthusiastic praise from throughout DOE, the National Nuclear Security Administration (NNSA), and the scientific community. NNSA Administrator Linton Brooks said, ''Our national laboratories now have at their disposal a valuable asset that enhances our due diligence to certify the nuclear weapons stockpile in the absence of underground nuclear weapons testing.''

  16. Sounding Natural in English

    Institute of Scientific and Technical Information of China (English)



    Chinese is a "tonal" language with four different "tones". In standard Chinese the words "soup", "sugar", "recline", and "burn" are all pronounced as "tang". The first tone could be represented as a straight line, like this: - which is a high, flat sound. The second tone could

  17. The Sounds of Metal

    DEFF Research Database (Denmark)

    Grund, Cynthia M.


    Two, I propose that this framework allows for at least a theoretical distinction between the way in which extreme metal – e.g. black metal, doom metal, funeral doom metal, death metal – relates to its sound as music and the way in which much other music may be conceived of as being constituted...

  18. The Universe of Sound

    CERN Document Server

    CERN. Geneva


    Sound Scultor, Bill Fontana, the second winner of the Prix Ars Electronica Collide@CERN residency award, and his science inspiration partner, CERN cosmologist Subodh Patil, present their work in art and science at the CERN Globe of Science and Innovation on 4 July 2013 at 19:00.

  19. Sound of proteins

    DEFF Research Database (Denmark)


    and statistical analysis of the resulting molecular trajectories (as everybody else!). However, recently I started assigning a particular sound frequency to each amino acid in the protein, and by setting the amplitude of each frequency according to the movement amplitude we can "hear" whenever two aminoacids...

  20. Creative Sound Dramatics (United States)

    Hendrix, Rebecca; Eick, Charles


    Sound propagation is not easy for children to understand because of its abstract nature, often best represented by models such as wave drawings and particle dots. Teachers Rebecca Hendrix and Charles Eick wondered how science inquiry, when combined with an unlikely discipline like drama, could produce a better understanding among their…

  1. Sound, memory and interruption

    DEFF Research Database (Denmark)

    Pinder, David


    around a thousand people. The highway was strongly resisted and it became the site of one of the country’s longest and largest anti-road struggles. The chapter addresses specifically Graeme Miller’s sound walk LINKED (2003), which for more than a decade has been broadcasting memories and stories...

  2. Exploring Sound with Insects (United States)

    Robertson, Laura; Meyer, John R.


    Differences in insect morphology and movement during singing provide a fascinating opportunity for students to investigate insects while learning about the characteristics of sound. In the activities described here, students use a free online computer software program to explore the songs of the major singing insects and experiment with making…

  3. Sound of Stockholm

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh


    Med sine kun 4 år bag sig er Sound of Stockholm relativt ny i det internationale festival-landskab. Festivalen er efter sigende udsprunget af en større eller mindre frustration over, at den svenske eksperimentelle musikscenes forskellige foreninger og organisationer gik hinanden bedene, og at kon...

  4. SoleSound

    DEFF Research Database (Denmark)

    Zanotto, Damiano; Turchet, Luca; Boggs, Emily Marie;


    This paper introduces the design of SoleSound, a wearable system designed to deliver ecological, audio-tactile, underfoot feedback. The device, which primarily targets clinical applications, uses an audio-tactile footstep synthesis engine informed by the readings of pressure and inertial sensors...

  5. Sunny Norton Sound (United States)


    A clear day over Norton Sound in the Bering Sea allowed SeaWiFS to capture this image of the phytoplankton bloom off the coast of Alaska. Credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  6. Statistical Analysis for Subjective and Objective Evaluations of Dental Drill Sounds.

    Directory of Open Access Journals (Sweden)

    Tomomi Yamada

    Full Text Available The sound produced by a dental air turbine handpiece (dental drill can markedly influence the sound environment in a dental clinic. Indeed, many patients report that the sound of a dental drill elicits an unpleasant feeling. Although several manufacturers have attempted to reduce the sound pressure levels produced by dental drills during idling based on ISO 14457, the sound emitted by such drills under active drilling conditions may negatively influence the dental clinic sound environment. The physical metrics related to the unpleasant impressions associated with dental drill sounds have not been determined. In the present study, psychological measurements of dental drill sounds were conducted with the aim of facilitating improvement of the sound environment at dental clinics. Specifically, we examined the impressions elicited by the sounds of 12 types of dental drills in idling and drilling conditions using a semantic differential. The analysis revealed that the impressions of dental drill sounds varied considerably between idling and drilling conditions and among the examined drills. This finding suggests that measuring the sound of a dental drill in idling conditions alone may be insufficient for evaluating the effects of the sound. We related the results of the psychological evaluations to those of measurements of the physical metrics of equivalent continuous A-weighted sound pressure levels (LAeq and sharpness. Factor analysis indicated that impressions of the dental drill sounds consisted of two factors: "metallic and unpleasant" and "powerful". LAeq had a strong relationship with "powerful impression", calculated sharpness was positively related to "metallic impression", and "unpleasant impression" was predicted by the combination of both LAeq and calculated sharpness. The present analyses indicate that, in addition to a reduction in sound pressure level, refining the frequency components of dental drill sounds is important for creating a

  7. About sound mufflers sound-absorbing panels aircraft engine (United States)

    Dudarev, A. S.; Bulbovich, R. V.; Svirshchev, V. I.


    The article provides a formula for calculating the frequency of sound absorbed panel with a perforated wall. And although the sound absorbing structure is a set of resonators Helmholtz, not individual resonators should be considered in acoustic calculations, and all the perforated wall panel. The analysis, showing how the parameters affect the size and sound-absorbing structures in the absorption rate.


    Directory of Open Access Journals (Sweden)

    Al Al-Falahi Amir


    Full Text Available An experimental study has been performed to investigate transient flows in a supersonic gun tunnel. The experimental work was performed using a short duration high speed flow test facility at the Universiti Tenaga Nasional (UNITEN. A physical description of the facility along with the principles of operation is provided. The pressure history of the flow process was captured using a fast response pressure transducer at three stations located at the end of the facility. Experimental measurements of shock strength, peak pressure and shock wave speed change of Air-Air as a driver/driven gas are then presented and compared with a further set of experimental measurements using the gas combination of Helium-Air. The shock wave speed was measured experimentally with a two pressure transducers technique. The results showed that the existence of the piston has a very significant influence on both the moving shock wave and peak pressure value achieved. The results provide a very good estimate for the above-mentioned parameters obtained after diaphragm rupture, and also provide a better understanding of the parameters that affect the performance of the facility.

  9. Data sonification and sound visualization



    This article describes a collaborative project between researchers in the Mathematics and Computer Science Division at Argonne National Laboratory and the Computer Music Project of the University of Illinois at Urbana-Champaign. The project focuses on the use of sound for the exploration and analysis of complex data sets in scientific computing. The article addresses digital sound synthesis in the context of DIASS (Digital Instrument for Additive Sound Synthesis) and sound visualization in a ...

  10. Measuring the `complexity’ of sound

    Indian Academy of Sciences (India)

    Nandini Chatterjee Singh


    Sounds in the natural environment form an important class of biologically relevant nonstationary signals. We propose a dynamic spectral measure to characterize the spectral dynamics of such non-stationary sound signals and classify them based on rate of change of spectral dynamics. We categorize sounds with slowly varying spectral dynamics as simple and those with rapidly changing spectral dynamics as complex. We propose rate of spectral dynamics as a possible scheme to categorize sounds in the environment.

  11. The Trend of Missile-Gun Combined Weapon System for Aerial Defense%弹炮结合防空武器系统新趋势

    Institute of Scientific and Technical Information of China (English)

    陈薇; 王军


    Since the Kosovo War started to use a form of simple air raids and counter-air raids,a increasing number of wars use air raids to attack the enemy,so how to defense the enemy in the air become more and more important. Missile-Gun combined weapon system not only has a big air defense area but also has a high effective-cost,so it will become the trend of air defense weapon system. This paper describes the structure and classification of Missile-Gun combined weapon system,and analyzes the advantages and disadvantages of the current systems; finally the trend of Missile-Gun combined weapon system is proposed.%自从科索沃战争开创了单纯空袭作战与反空袭作战的先例之后,空袭就成为了战争的焦点,如何更好地抵御空中目标的来袭成为各国战争防御的主题。弹炮结合防空武器系统具有防空区域大、效费比高等优点,是防空武器系统的发展趋势之一。在分析现有典型弹炮结合防空武器系统的基础上,依据弹炮结合武器系统是否共用火控系统将其分为弹炮混编式和弹炮同控式两种形式;随后,结合现代空袭的特点提出了弹炮结合武器系统的发展趋势。

  12. Just How Does Sound Wave? (United States)

    Shipman, Bob


    When children first hear the term "sound wave" perhaps they might associate it with the way a hand waves or perhaps the squiggly line image on a television monitor when sound recordings are being made. Research suggests that children tend to think sound somehow travels as a discrete package, a fast-moving invisible thing, and not something that…

  13. Low frequency sound attenuation in a flow duct using a thin slow sound material. (United States)

    Aurégan, Yves; Farooqui, Maaz; Groby, Jean-Philippe


    A thin subwavelength material that can be flush mounted in a duct and that gives an attenuation band at low frequencies in air flow channels is presented. To decrease the material thickness, the sound is slowed in the material using folded side branch tubes. The impedance of the material is compared to the optimal value given by the Cremer condition, which can differ greatly from the air characteristic impedance. Grazing flow on this material increases the losses at the interface between the flow and the material.

  14. Development of S-band photocathode RF guns at Tsinghua University (United States)

    Zheng, Lianmin; Du, Yingchao; Zhang, Zhe; Qian, Houjun; Yan, Lixin; Shi, Jiaru; Zhang, Zhen; Zhou, Zheng; Wu, Xiaowei; Su, Xiaolu; Wang, Dong; Tian, Qili; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang


    This study aims to explain the development of S-band photocathode RF guns at Tsinghua University, with especial attention on the progress of guns developed after 2011. Two types of RF guns were developed based on the BNL/SLAC/UCLA gun prior 2011. These guns have been operated as electron sources for Tsinghua Thomson scattering X-ray source (TTX), MeV ultrafast electron diffraction, and Shanghai deep ultraviolet FEL test facility. Based on our operation experiences and other gun modifications worldwide, numerous improvements have been proposed, and seven third-type guns have been designed and fabricated since 2011. Cold tests of all third-type guns have been completed, confirming a significantly improved quality factor and mode separation. The first third-type gun has been installed on TTX and operated for four years, demonstrating high gradient, low dark current, stable quantum efficiency, and small emittances. The optimal transverse emittance was εx = 0.56 mm mrad , εy = 0.66 mm mrad for 200 pC with a peak current of 25 A, and εx = 0.78 mm mrad , εy = 0.92 mm mrad for 500 pC with a peak current of 62.5 A under a 110 MV/m gun gradient.

  15. Optimal Sound Absorbing Structures

    CERN Document Server

    Yang, Min; Fu, Caixing; Sheng, Ping


    Causal nature of the acoustic response, for any materials or structures, dictates an inequality that relates the absorption spectrum of the sample to its thickness. We present a general recipe for constructing sound-absorbing structures that can attain near-equality for the causal relation with very high absorption performance; such structures are denoted optimal. Our strategy involves using carefully designed acoustic metamaterials as backing to a thin layer of conventional sound absorbing material, e.g., acoustic sponge. By using this design approach, we have realized a 12 cm-thick structure that exhibits broadband, near-perfect flat absorption spectrum starting at around 400 Hz. From the causal relation, the calculated minimum sample thickness is 11.5 cm for the observed absorption spectrum. We present the theory that underlies such absorption performance, involving the evanescent waves and their interaction with a dissipative medium, and show the excellent agreement with the experiment.

  16. Sound in Ergonomics

    Directory of Open Access Journals (Sweden)

    Jebreil Seraji


    Full Text Available The word of “Ergonomics “is composed of two separate parts: “Ergo” and” Nomos” and means the Human Factors Engineering. Indeed, Ergonomics (or human factors is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimize human well-being and overall system performance. It has applied different sciences such as Anatomy and physiology, anthropometry, engineering, psychology, biophysics and biochemistry from different ergonomics purposes. Sound when is referred as noise pollution can affect such balance in human life. The industrial noise caused by factories, traffic jam, media, and modern human activity can affect the health of the society.Here we are aimed at discussing sound from an ergonomic point of view.

  17. Wood for sound. (United States)

    Wegst, Ulrike G K


    The unique mechanical and acoustical properties of wood and its aesthetic appeal still make it the material of choice for musical instruments and the interior of concert halls. Worldwide, several hundred wood species are available for making wind, string, or percussion instruments. Over generations, first by trial and error and more recently by scientific approach, the most appropriate species were found for each instrument and application. Using material property charts on which acoustic properties such as the speed of sound, the characteristic impedance, the sound radiation coefficient, and the loss coefficient are plotted against one another for woods. We analyze and explain why spruce is the preferred choice for soundboards, why tropical species are favored for xylophone bars and woodwind instruments, why violinists still prefer pernambuco over other species as a bow material, and why hornbeam and birch are used in piano actions.

  18. Pitch Based Sound Classification

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch; Hansen, Lars Kai; Kjems, U


    A sound classification model is presented that can classify signals into music, noise and speech. The model extracts the pitch of the signal using the harmonic product spectrum. Based on the pitch estimate and a pitch error measure, features are created and used in a probabilistic model with soft......-max output function. Both linear and quadratic inputs are used. The model is trained on 2 hours of sound and tested on publicly available data. A test classification error below 0.05 with 1 s classification windows is achieved. Further more it is shown that linear input performs as well as a quadratic......, and that even though classification gets marginally better, not much is achieved by increasing the window size beyond 1 s....

  19. Sound for Health

    CERN Document Server

    CERN. Geneva


    From astronomy to biomedical sciences: music and sound as tools for scientific investigation Music and science are probably two of the most intrinsically linked disciplines in the spectrum of human knowledge. Science and technology have revolutionised the way artists work, interact, and create. The impact of innovative materials, new communication media, more powerful computers, and faster networks on the creative process is evident: we all can become artists in the digital era. What is less known, is that arts, and music in particular, are having a profound impact the way scientists operate, and think. From the early experiments by Kepler to the modern data sonification applications in medicine – sound and music are playing an increasingly crucial role in supporting science and driving innovation. In this talk. Dr. Domenico Vicinanza will be highlighting the complementarity and the natural synergy between music and science, with specific reference to biomedical sciences. Dr. Vicinanza will take t...

  20. Improvement of pump tubes for gas guns and shock tube drivers (United States)

    Bogdanoff, D. W.


    In a pump tube, a gas is mechanically compressed, producing very high pressures and sound speeds. The intensely heated gas produced in such a tube can be used to drive light gas guns and shock tubes. Three concepts are presented that have the potential to allow substantial reductions in the size and mass of the pump tube to be achieved. The first concept involves the use of one or more diaphragms in the pump tube, thus replacing a single compression process by multiple, successive compressions. The second concept involves a radical reduction in the length-to-diameter ratio of the pump tube and the pump tube piston. The third concept involves shock heating of the working gas by high explosives in a cyclindrical geometry reusable device. Preliminary design analyses are performed on all three concepts and they appear to be quite feasible. Reductions in the length and mass of the pump tube by factors up to about 11 and about 7, respectively, are predicted, relative to a benchmark conventional pump tube.