WorldWideScience

Sample records for gene gun administration

  1. Administration of HPV DNA vaccine via electroporation elicits the strongest CD8+ T cell immune responses compared to intramuscular injection and intradermal gene gun delivery

    Science.gov (United States)

    Best, Simon R.; Peng, Shiwen; Juang, Chi-Mou; Hung, Chien-Fu; Hannaman, Drew; Saunders, John R.; Wu, T.-C.; Pai, Sara I.

    2009-01-01

    DNA vaccines are an attractive approach to eliciting antigen-specific immunity. Intracellular targeting of tumor antigens through its linkage to immunostimulatory molecules such as calreticulin (CRT) can improve antigen processing and presentation through the MHC Class I pathway and increase cytotoxic CD8+ T cell production. However, even with these enhancements, the efficacy of such immunotherapeutic strategies is dependent on the identification of an effective route and method of DNA administration. Electroporation and gene gun-mediated particle delivery are leading methods of DNA vaccine delivery that can generate protective and therapeutic levels of immune responses in experimental models. In this study, we perform a head-to-head comparison of three methods of vaccination – conventional intramuscular injection, electroporation mediated intramuscular delivery, and epidermal gene gun-mediated particle delivery - in the ability to generate antigen specific cytotoxic CD8+ T cell responses as well as anti-tumor immune responses against an HPV-16 E7 expressing tumor cell line using the pNGVL4a-CRT/E7(detox) DNA vaccine. Vaccination via electroporation generated the highest number of E7-specific cytotoxic CD8+ T cells, which correlated to improved outcomes in the treatment of growing tumors. In addition, we demonstrate that electroporation results in significantly higher levels of circulating protein compared to gene gun or intramuscular vaccination, which likely enhances calreticulin’s role as a local tumor anti-angiogenesis agent. We conclude that electroporation is a promising method for delivery of HPV DNA vaccines and should be considered for DNA vaccine delivery in human clinical trials. PMID:19622402

  2. Gene Gun Bombardment with DNA-Coated Golden Particles Enhanced the Protective Effect of a DNA Vaccine Based on Thioredoxin Glutathione Reductase of Schistosoma japonicum

    Directory of Open Access Journals (Sweden)

    Yan Cao

    2013-01-01

    Full Text Available Schistosomiasis, caused by infection with Schistosoma species, remains an important parasitic zoonosis. Thioredoxin glutathione reductase of Schistosoma japonicum (SjTGR plays an important role in the development of the parasite and for its survival. Here we present a recombinant plasmid DNA vaccine, pVAX1/SjTGR, to estimate its protection against S. japonicum in BALB/c mice. The DNA vaccine administrated by particle bombardment induced higher protection than by intramuscular injection. All animals vaccinated with pVAX1/SjTGR developed significant specific anti-SjTGR antibodies than control groups. Moreover, animals immunized by gene gun exhibited a splenocyte proliferative response, with an increase in IFN-γ and IL-4. The recombinant plasmid administrated by gene gun achieved a medium protective efficacy of 27.83–38.83% ( of worm reduction and 40.38–44.51% ( of liver egg count reduction. It suggests that different modes of administering a DNA vaccine can influence the protective efficacy induced by the vaccine. Interestingly, from the enzymatic activity results, we found that worms obtained from pVAX1/SjTGR-vaccinated animals expressed lower enzymatic activity than the control group and the antibodies weakened the enzymatic activity of SjTGR in vitro, too. It implies that the high-level antibodies may contribute to the protective effects.

  3. Gun Play

    Science.gov (United States)

    Mechling, Jay

    2008-01-01

    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…

  4. Gene gun bombardment-mediated expression and translocation of EGFP-tagged GLUT4 in skeletal muscle fibres in vivo

    DEFF Research Database (Denmark)

    Lauritzen, Hans P M M; Reynet, Christine; Schjerling, Peter

    2002-01-01

    the enhanced green fluorescent protein (EGFP) labelling technique with physical transfection methods in vivo: intramuscular plasmid injection or gene gun bombardment. During optimisation experiments with plasmid coding for the EGFP reporter alone EGFP-positive muscle fibres were counted after collagenase...... treatment of in vivo transfected flexor digitorum brevis (FDB) muscles. In contrast to gene gun bombardment, intramuscular injection produced EGFP expression in only a few fibres. Regardless of the transfection technique, EGFP expression was higher in muscles from 2-week-old rats than in those from 6-week......Cellular protein trafficking has been studied to date only in vitro or with techniques that are invasive and have a low time resolution. To establish a gentle method for analysis of glucose transporter-4 (GLUT4) trafficking in vivo in fully differentiated rat skeletal muscle fibres we combined...

  5. Microneedle assisted micro-particle delivery from gene guns: experiments using skin-mimicking agarose gel.

    Science.gov (United States)

    Zhang, Dongwei; Das, Diganta B; Rielly, Chris D

    2014-02-01

    A set of laboratory experiments has been carried out to determine if micro-needles (MNs) can enhance penetration depths of high-speed micro-particles delivered by a type of gene gun. The micro-particles were fired into a model target material, agarose gel, which was prepared to mimic the viscoelastic properties of porcine skin. The agarose gel was chosen as a model target as it can be prepared as a homogeneous and transparent medium with controllable and reproducible properties allowing accurate determination of penetration depths. Insertions of various MNs into gels have been analysed to show that the length of the holes increases with an increase in the agarose concentration. The penetration depths of micro-particle were analysed in relation to a number of variables, namely the operating pressure, the particle size, the size of a mesh used for particle separation and the MN dimensions. The results suggest that the penetration depths increase with an increase of the mesh pore size, because of the passage of large agglomerates. As these particles seem to damage the target surface, then smaller mesh sizes are recommended; here, a mesh with a pore size of 178 μm was used for the majority of the experiments. The operating pressure provides a positive effect on the penetration depth, that is it increases as pressure is increased. Further, as expected, an application of MNs maximises the micro-particle penetration depth. The maximum penetration depth is found to increase as the lengths of the MNs increase, for example it is found to be 1272 ± 42, 1009 ± 49 and 656 ± 85 μm at 4.5 bar pressure for spherical micro-particles of 18 ± 7 μm diameter when we used MNs of 1500, 1200 and 750 μm length, respectively. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  6. Gun Safety

    Science.gov (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 ...

  7. Leishmania mexicana Gp63 cDNA Using Gene Gun Induced Higher Immunity to L. mexicana Infection Compared to Soluble Leishmania Antigen in BALB/C

    Science.gov (United States)

    Rezvan, H; Rees, R; Ali, SA

    2011-01-01

    Background Leishmaniasis is a worldwide disease prevalent in tropical and sub tropical countries. Many attempts have been made and different strategies have been approached to develop a potent vaccine against Leishmania. DNA immunisation is a method, which is shown to be effective in Leishmania vaccination. Leishmania Soluble Antigen (SLA) has also recently been used Leishmania vaccination. Methods The immunity generated by SLA and L. mexicana gp63 cDNA was compared in groups of 6 mice, which were statistically analysed by student t- test with the P-value of 0.05. SLA was administered by two different methods; intramuscular injection and injection of dendritic cells (DCs) loaded with SLA. L. mexicana gp63 cDNA was administered by the gene gun. Results Immunisation of BALB/c mice with L. mexicana gp63 resulted in high levels of Th1-type immune response and cytotoxic T lymphocytes (CTL) activity, which were accompanied with protection induced by the immunisation against L. mexicana infection. In contrast, administration of SLA, produced a mixed Th1/Th2-type immune responses as well as a high level of CTL activity but did not protect mice from the infection. Conclusion The results indicate higher protection by DNA immunisation using L. mexicana gp63 cDNA compared to SLA, which is accompanied by a high level of Th1 immune response. However, the CTL activity does not necessarily correlate with the protection induced by the vaccine. Also, gene gun immunisation is a potential approach in Leishmania vaccination. These findings would be helpful in opening new windows in Leishmania vaccine research. PMID:22347315

  8. A functional polymorphism in a serotonin transporter gene (5-HTTLPR) interacts with 9/11 to predict gun-carrying behavior.

    Science.gov (United States)

    Barnes, J C; Beaver, Kevin M; Boutwell, Brian B

    2013-01-01

    On September 11, 2001, one of the deadliest terrorist attacks in US history took place on American soil and people around the world were impacted in myriad ways. Building on prior literature which suggests individuals are more likely to purchase a gun for self-protection if they are fearful of being victimized, the authors hypothesized that the terrorist attacks of 9/11 would lead to an increase in gun carrying among US residents. At the same time, a line of research has shown that a polymorphism in the 5-HTT gene (i.e., 5-HTTLPR) interacts with environmental stressors to predict a range of psychopathologies and behaviors. Thus, it was hypothesized that 9/11 and 5-HTTLPR would interact to predict gun carrying. The results supported both hypotheses by revealing a positive association between 9/11 and gun carrying (b = .426, odds ratio = 1.531, standard error for b = .194, z = 2.196, p = .028) in the full sample of respondents (n = 15,052) and a statistically significant interaction between 9/11 and 5-HTTLPR in the prediction of gun carrying (b = -1.519, odds ratio = .219, standard error for b = .703, z = -2.161, p = .031) in the genetic subsample of respondents (n = 2,350). This is one of the first studies to find an association between 9/11 and gun carrying and, more importantly, is the first study to report a gene-environment interaction (GxE) between a measured gene and a terrorist attack.

  9. Gun Concerns Personal for Duncan

    Science.gov (United States)

    McNeil, Michele

    2013-01-01

    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…

  10. Gun Safety (For Kids)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Gun Safety KidsHealth / For Kids / Gun Safety What's in ... from guns outside the home. If You Have Guns in Your Home If your parents keep guns ...

  11. Sanoli Gun

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences. Sanoli Gun. Articles written in Proceedings – Mathematical Sciences. Volume 119 Issue 3 June 2009 pp 275-281. Remarks on some Zero-Sum Theorems · S D Adhikari Sanoli Gun Purusottam Rath · More Details Abstract Fulltext PDF. In the present paper, we give a ...

  12. Myostatin propeptide gene delivery by gene gun ameliorates muscle atrophy in a rat model of botulinum toxin-induced nerve denervation.

    Science.gov (United States)

    Tsai, Sen-Wei; Tung, Yu-Tang; Chen, Hsiao-Ling; Yang, Shang-Hsun; Liu, Chia-Yi; Lu, Michelle; Pai, Hui-Jing; Lin, Chi-Chen; Chen, Chuan-Mu

    2016-02-01

    Muscle atrophy is a common symptom after nerve denervation. Myostatin propeptide, a precursor of myostatin, has been documented to improve muscle growth. However, the mechanism underlying the muscle atrophy attenuation effects of myostatin propeptide in muscles and the changes in gene expression are not well established. We investigated the possible underlying mechanisms associated with myostatin propeptide gene delivery by gene gun in a rat denervation muscle atrophy model, and evaluated gene expression patterns. In a rat botulinum toxin-induced nerve denervation muscle atrophy model, we evaluated the effects of wild-type (MSPP) and mutant-type (MSPPD75A) of myostatin propeptide gene delivery, and observed changes in gene activation associated with the neuromuscular junction, muscle and nerve. Muscle mass and muscle fiber size was moderately increased in myostatin propeptide treated muscles (pmyostatin propeptide gene delivery, especially the mutant-type of MSPPD75A, attenuates muscle atrophy through myogenic regulatory factors and acetylcholine receptor regulation. Our data concluded that myostatin propeptide gene therapy may be a promising treatment for nerve denervation induced muscle atrophy. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Methylation of the chicken vitellogenin gene: influence of estradiol administration.

    Science.gov (United States)

    Meijlink, F C; Philipsen, J N; Gruber, M; Ab, G

    1983-01-01

    The degree of methylation of the chicken vitellogenin gene has been investigated. Upon induction by administration of estradiol to a rooster, methyl groups at specific sites near the 5'-end of the gene are eliminated. The process of demethylation is slower than the activation of the gene. Demethylation is therefore probably not a prerequisite to gene transcription. At least two other sites in the coding region of the gene are methylated in the liver of estrogenized roosters, but not in the liver of a laying hen, where the gene is naturally active. Images PMID:6298743

  14. Gun Control, Gun Ownership, and Suicide Prevention.

    Science.gov (United States)

    Lester, David

    1988-01-01

    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)

  15. A Gene Gun-mediated Nonviral RNA trans-splicing Strategy for Col7a1 Repair

    Directory of Open Access Journals (Sweden)

    Patricia Peking

    2016-01-01

    Full Text Available RNA trans-splicing represents an auspicious option for the correction of genetic mutations at RNA level. Mutations within COL7A1 causing strong reduction or absence of type VII collagen are associated with the severe skin blistering disease dystrophic epidermolysis bullosa. The human COL7A1 mRNA constitutes a suitable target for this RNA therapy approach, as only a portion of the almost 9 kb transcript has to be delivered into the target cells. Here, we have proven the feasibility of 5′ trans-splicing into the Col7a1 mRNA in vitro and in vivo. We designed a 5′ RNA trans-splicing molecule, capable of replacing Col7a1 exons 1–15 and verified it in a fluorescence-based trans-splicing model system. Specific and efficient Col7a1 trans-splicing was confirmed in murine keratinocytes. To analyze trans-splicing in vivo, we used gene gun delivery of a minicircle expressing a FLAG-tagged 5′ RNA trans-splicing molecule into the skin of wild-type mice. Histological and immunofluorescence analysis of bombarded skin sections revealed vector delivery and expression within dermis and epidermis. Furthermore, we have detected trans-spliced type VII collagen protein using FLAG-tag antibodies. In conclusion, we describe a novel in vivo nonviral RNA therapy approach to restore type VII collagen expression for causative treatment of dystrophic epidermolysis bullosa.

  16. Changes in skeletal muscle gene expression following clenbuterol administration

    Directory of Open Access Journals (Sweden)

    McIntyre Lauren M

    2006-12-01

    Full Text Available Abstract Background Beta-adrenergic receptor agonists (BA induce skeletal muscle hypertrophy, yet specific mechanisms that lead to this effect are not well understood. The objective of this research was to identify novel genes and physiological pathways that potentially facilitate BA induced skeletal muscle growth. The Affymetrix platform was utilized to identify gene expression changes in mouse skeletal muscle 24 hours and 10 days after administration of the BA clenbuterol. Results Administration of clenbuterol stimulated anabolic activity, as indicated by decreased blood urea nitrogen (BUN; P P Conclusion Global evaluation of gene expression after administration of clenbuterol identified changes in gene expression and overrepresented functional categories of genes that may regulate BA-induced muscle hypertrophy. Changes in mRNA abundance of multiple genes associated with myogenic differentiation may indicate an important effect of BA on proliferation, differentiation, and/or recruitment of satellite cells into muscle fibers to promote muscle hypertrophy. Increased mRNA abundance of genes involved in the initiation of translation suggests that increased levels of protein synthesis often associated with BA administration may result from a general up-regulation of translational initiators. Additionally, numerous other genes and physiological pathways were identified that will be important targets for further investigations of the hypertrophic effect of BA on skeletal muscle.

  17. Electron gun

    International Nuclear Information System (INIS)

    Chen, H.-Y.; Hughes, R.H.

    1979-01-01

    The invention described relates to cathode ray tubes, and particularly to color picture tubes of the type useful in home television receivers and therefore to electron guns. The invention is especially applicable to self-converging tube-yoke combinations with shadow mask tubes of the type having plural-beam in-line guns disposed in a horizontal plane, an apertured mask with vertically oriented slit-shaped apertures, and a screen with vertically oriented phosphor stripes. The invention is not, however, limited to use in such tubes and may in fact be used, e.g., in dot-type shadow mask tubes and index-type tubes. (Auth.)

  18. Gene-gun DNA vaccination aggravates respiratory syncytial virus-induced pneumonitis

    DEFF Research Database (Denmark)

    Bartholdy, Christina; Olszewska, Wieslawa; Stryhn, Anette

    2004-01-01

    elicited with recombinant vaccinia virus expressing the complete RSV M2 protein, but stronger than those induced by a similar DNA construct without the beta2m gene. DNA vaccination led to enhanced pulmonary disease after RSV challenge, with increased weight loss and cell recruitment to the lung. Depletion......A CD8+ T-cell memory response to respiratory syncytial virus (RSV) was generated by using a DNA vaccine construct encoding the dominant Kd-restricted epitope from the viral transcription anti-terminator protein M2 (M2(82-90)), linked covalently to human beta2-microglobulin (beta2m). Cutaneous gene...... of CD8+ T cells reduced, but did not abolish, enhancement of disease. Mice vaccinated with a construct encoding a class I-restricted lymphocytic choriomeningitis virus epitope and beta2m suffered more severe weight loss after RSV infection than unvaccinated RSV-infected mice, although RSV-specific CD8...

  19. Spectrometer gun

    Science.gov (United States)

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

    1985-01-01

    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.

  20. Water gun vs air gun: A comparison

    Science.gov (United States)

    Hutchinson, D.R.; Detrick, R. S.

    1984-01-01

    The water gun is a relatively new marine seismic sound source that produces an acoustic signal by an implosive rather than explosive mechanism. A comparison of the source characteristics of two different-sized water guns with those of conventional air guns shows the the water gun signature is cleaner and much shorter than that of a comparable-sized air gun: about 60-100 milliseconds (ms) for an 80-in3. (1.31-liter (I)) water gun compared with several hundred ms for an 80-in3. (1.31-1) air gun. The source spectra of water guns are richer in high frequencies (>200 Hz) than are those of air guns, but they also have less energy than those of air guns at low frequencies. A comparison between water gun and air gun reflection profiles in both shallow (Long Island Sound)-and deep (western Bermuda Rise)-water settings suggests that the water gun offers a good compromise between very high resolution, limited penetration systems (e.g. 3.5-kHz profilers and sparkers) and the large volume air guns and tuned air gun arrays generally used where significant penetration is required. ?? 1984 D. Reidel Publishing Company.

  1. ELECTRON GUN

    Science.gov (United States)

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

    1960-04-01

    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.

  2. ION GUN

    Science.gov (United States)

    Dandl, R.A.

    1961-10-24

    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)

  3. Gun ownership and social gun culture.

    Science.gov (United States)

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

    2016-06-01

    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. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  4. Encyclopedia of Gun Control and Gun Rights.

    Science.gov (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…

  5. Gun control saves lives

    African Journals Online (AJOL)

    gun control legislation. One study estimated that more than 4 500 lives were saved across five SA cities from 2001 to 2005.[5] Pro-gun interest groups seeking to promote gun ownership and diffusion have attacked these findings, suggesting that stricter gun control was only enacted in 2004 following the publication of ...

  6. Gun Sales. Firearm Facts.

    Science.gov (United States)

    Duker, Laurie, Ed.

    Minimal federal regulations on firearm sales have facilitated the proliferation of guns, gun owners, and gun dealers in the United States. This fact sheet offers data on the growing number of firearm dealers, the relative ease of obtaining and keeping a license to sell guns from the Federal Bureau of Alcohol, Tobacco, and Firearms, the lack of…

  7. Enhanced anti-tumor effect of a gene gun-delivered DNA vaccine encoding the human papillomavirus type 16 oncoproteins genetically fused to the herpes simplex virus glycoprotein D

    Directory of Open Access Journals (Sweden)

    M.O. Diniz

    2011-05-01

    Full Text Available Anti-cancer DNA vaccines have attracted growing interest as a simple and non-invasive method for both the treatment and prevention of tumors induced by human papillomaviruses. Nonetheless, the low immunogenicity of parenterally administered vaccines, particularly regarding the activation of cytotoxic CD8+ T cell responses, suggests that further improvements in both vaccine composition and administration routes are still required. In the present study, we report the immune responses and anti-tumor effects of a DNA vaccine (pgD-E7E6E5 expressing three proteins (E7, E6, and E5 of the human papillomavirus type 16 genetically fused to the glycoprotein D of the human herpes simplex virus type 1, which was administered to mice by the intradermal (id route using a gene gun. A single id dose of pgD-E7E6E5 (2 µg/dose induced a strong activation of E7-specific interferon-γ (INF-γ-producing CD8+ T cells and full prophylactic anti-tumor effects in the vaccinated mice. Three vaccine doses inhibited tumor growth in 70% of the mice with established tumors. In addition, a single vaccine dose consisting of the co-administration of pgD-E7E6E5 and the vector encoding interleukin-12 or granulocyte-macrophage colony-stimulating factor further enhanced the therapeutic anti-tumor effects and conferred protection to 60 and 50% of the vaccinated mice, respectively. In conclusion, id administration of pgD-E7E6E5 significantly enhanced the immunogenicity and anti-tumor effects of the DNA vaccine, representing a promising administration route for future clinical trials.

  8. ORELA electron guns

    International Nuclear Information System (INIS)

    Christian, O.W.; Lewis, T.A.

    1981-09-01

    The most recent information concerning the production and performance of ORELA electron guns is presented. Included are descriptions of procedures for gun fabrication, cathode conditioning and high voltage processing. Highlights of the performance characteristics are also included

  9. Electron gun for SSRF

    International Nuclear Information System (INIS)

    Sheng Shugang; Lin Guoqiang; Gu Qiang; Li Deming

    2003-01-01

    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

  10. Guns and Violence. Current Controversies.

    Science.gov (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…

  11. Curcumin administration suppress acetylcholinesterase gene expression in cadmium treated rats.

    Science.gov (United States)

    Akinyemi, Ayodele Jacob; Oboh, Ganiyu; Fadaka, Adewale Oluwaseun; Olatunji, Babawale Peter; Akomolafe, Seun

    2017-09-01

    Curcumin, the main polyphenolic component of turmeric (Curcuma longa) rhizomes have been reported to exert anticholinesterase potential with limited information on how they regulate acetylcholinesterase (AChE) gene expression. Hence, this study sought to evaluate the effect of curcumin on cerebral cortex acetylcholinesterase (AChE) activity and their mRNA gene expression level in cadmium (Cd)-treated rats. Furthermore, in vitro effect of different concentrations of curcumin (1-5μg/mL) on rat cerebral cortex AChE activity was assessed. Animals were divided into six groups (n=6): group 1 serve as control (without Cd) and receive saline/vehicle, group 2 receive saline plus curcumin at 25mg/kg, group 3 receive saline plus curcumin 50mg/kg, group 4 receive Cd plus vehicle, group 5 receive Cd plus curcumin at 25mg/kg and group 6 receive Cd plus curcumin at 50mg/kg. Rats received Cd (2.5mg/kg) and curcumin (25 and 50mg/kg, respectively) by oral gavage for 7days. Acetylcholinesterase activity was measured by Ellman's method and AChE expression was carried out by a quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) assay. We observed that acute administration of Cd increased acetylcholinesterase activity and in addition caused a significant (Pcurcumin inhibited AChE activity and alters AChE mRNA levels when compared to Cd-treated group. In addition, curcumin inhibits rat cerebral cortex AChE activity in vitro. In conclusion, curcumin exhibit anti-acetylcholinesterase activity and suppressed AChE mRNA gene expression level in Cd exposed rats, thus providing some biochemical and molecular evidence on the therapeutic effect of this turmeric-derived compound in treating neurological disorders including Alzheimer's disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Gun Theft and Crime.

    Science.gov (United States)

    Cook, Philip J

    2018-06-01

    Some law enforcement officials and other observers have asserted that theft is the primary source of guns to crime. In fact, the role of theft in supplying the guns used in robbery, assault, and murder is unknown, and current evidence provides little guidance about whether an effective program to reduce gun theft would reduce gun violence. The current article analyzes publicly available national data on gun theft together with a unique data set for Chicago. The results tend to support a conclusion that stolen guns play only a minor role in crime. First, publicly available data are used to calculate that thefts are only about 1% of all gun transactions nationwide. Second, an analysis of original data from Chicago demonstrates that less than 3% of crime guns recovered by the police have been reported stolen to the Chicago Police Department (CPD). If a gun is reported stolen, there is a 20% chance that it will be recovered, usually in conjunction with an arrest for illegal carrying. Less than half of those picked up with a stolen gun have a criminal record that includes violent offenses. Third, results from surveys of convicted criminals, both nationally and in Chicago, suggest that it is rare for respondents to have stolen the gun used in their most recent crime. The data on which these results are based have various shortcomings. A research agenda is proposed that would provide more certainty about the role of theft.

  13. Whose guns are stolen? The epidemiology of Gun theft victims.

    Science.gov (United States)

    Hemenway, David; Azrael, Deborah; Miller, Matthew

    2017-12-01

    Gun theft is an important source of guns used by criminals. Yet no empirical work has focused on the characteristics of gun owners that distinguish those who have had their guns stolen from those who have not. In this study, we examine the demographics and behavioral characteristics of gun owners who report having had a gun stolen. Data come from a nationally representative probability-based online survey conducted in April 2015, with a linked follow-up survey in November 2015 that asked gun owners about any theft of their guns in the past 5 years. Of 1,604 gun-owning respondents, 2.4% (95% CI 1.6,3.6) reported that one or more guns had been stolen, with a mean number of guns stolen per theft of 1.5 (95% CI 1.0,2.0]. Risk factors for having a gun stolen were owning 6 or more guns, owning guns for protection, carrying a gun in the past month, storing guns unsafely, and living in the South region of the United States. The South accounts for 37% of US households, 43% of gun owners, and two-thirds of all gun thefts. We estimate that there are approximately 250,000 gun theft incidents per year, with about 380,000 guns stolen. We find that certain types of gun owners-who own many guns, who carry guns, and who do not store guns safely-are at higher risk to have their guns stolen. Tracing data show that states in the South are exporters of crime guns used in other states. Our survey results find that the majority of guns stolen in the US come from the South.

  14. Carbon Nanotube Electron Gun

    Science.gov (United States)

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

    2013-01-01

    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.

  15. Carbon plasma gun

    International Nuclear Information System (INIS)

    Mendel, C.W. Jr.; Zagar, D.M.; Mills, G.S.; Humphries, S. Jr.; Goldstein, S.A.

    1980-01-01

    A family of plasma guns supplying highly ionized carbon plasma is described. The guns are simple and inexpensive to construct and are pulsed by small capacitor banks of a few hundred joules. The output consists of 10 17 --10 18 multiply ionized carbon ions traveling at about 10 7 cm/s. Neutral output is very low and arrives well after the ionized carbon. The guns and pulsers are very reliable

  16. CID thermionic gun system

    International Nuclear Information System (INIS)

    Koontz, R.F.

    1981-10-01

    A new high-current thermionic gun has been installed on the CID injector at SLAC and brought into operation. The gun and pulser system generate three nanosecond pulses of about six amps peak which, when bunched in the subharmonic buncher system, produce in excess of 10 11 electrons in a single S-band accelerated bunch. Preliminary operation of the gun is described, and details of the avalanche cathode drive pulser are presented

  17. CID thermionic gun system

    International Nuclear Information System (INIS)

    Koontz, R.F.

    1982-01-01

    A new high-current thermionic gun has been installed on the CID injector at SLAC and brought into operation. The gun and pulser system generate three nanosecond pulses of about six amps peak which, when bunched in the subharmonic buncher system, produce in excess of 10 11 electrons in a single S-band accelerated bunch. Preliminary operation of the gun is described, and details of the avalanche cathode drive pulser are presented

  18. Simplified pipe gun

    International Nuclear Information System (INIS)

    Sorensen, H.; Nordskov, A.; Sass, B.; Visler, T.

    1987-01-01

    A simplified version of a deuterium pellet gun based on the pipe gun principle is described. The pipe gun is made from a continuous tube of stainless steel and gas is fed in from the muzzle end only. It is indicated that the pellet length is determined by the temperature gradient along the barrel right outside the freezing cell. Velocities of around 1000 m/s with a scatter of +- 2% are obtained with a propellant gas pressure of 40 bar

  19. RF guns: a review

    International Nuclear Information System (INIS)

    Travier, C.

    1990-06-01

    Free Electron Lasers and future linear colliders require very bright electron beams. Conventional injectors made of DC guns and RF bunchers have intrinsic limitations. The recently proposed RF guns have already proven their capability to produce bright beams. The necessary effort to improve further these performances and to gain reliability is now undertaken by many laboratories. More than twenty RF gun projects both thermionic and laser-driven are reviewed. Their specific characteristics are outlined and their nominal performances are given

  20. Magnetized gun experiments

    International Nuclear Information System (INIS)

    Jarboe, T.R.; Henins, I.; Hoida, H.W.; Marshall, J.; Sherwood, A.R.

    1981-01-01

    In the Los Alamos Magnetized Gun Experiment we are attempting to produce a compact torus in a manner similar to an earlier experiment of Alfven. In our experiment a solenoidal coil is placed inside the inner electrode of a coaxial plasma gun. This coil produces an axial magnetic field inside the inner electrode which diverges and becomes a largely radial field in front of the gun muzzle. The idea is that when the gun is fired, the plasma escaping from the gun stretches these radial fields along the axial direction away from the gun, and these field lines can reconnect behind the plasma forming the poloidal field of the compact torus. The magnetic field generated by the gun current becomes the toroidal field and the major axis of the compact torus will be the same as the axis of the coaxial gun. Recent interest in this possible method of compact torus generation was stimulated by C. Hartman, and the approach is also being pursued in the field-reversed plasma gun experiment at LLL

  1. Electron guns for accelerators

    International Nuclear Information System (INIS)

    Rangarajan, L.M.; Mahadevan, S.; Ramamurthi, S.S.

    1995-01-01

    The high voltage, high current electron guns developed elsewhere for Linacs are based on cathode pulsing with direct emitting cathodes. Our grid pulsed triode gun employs indirect emitting cathode pellet under electron bombardment or a direct cathode emitter. Electron beam from the gun is injected to the accelerator guide at 40 kV and pulse duration is 2.8μsec. The gun is limited to axially symmetric geometry and electron optical design is optimized by computer programming. The gun with a water cooled Faraday cup is connected to a vacuum system comprising of a sputter ion pump and sorption pump. Working pressure is 1x10 -6 Pa. Gun is designed to be baked as an assembly at temperatures of 400 degC while vacuum processing. Materials are therefore restricted to refractory metals, SS, OFHC copper and all the electrodes are housed inside a ceramic tube. Lower Z graphite is used as a base material of Faraday cup. Grid is non-intercepting modulator anode, a new feature introduced, as compared to meshed grid system by others. CAT gun delivers 160 mA current pulses at 40 kV and its working characteristics such as perveance, emittance and beam radius compare well with SLAC and Hermosa guns. The above guns can be used for electron beam machines such as medical Linacs, industrial accelerators and EB welding equipment. (author). 2 refs., 2 figs

  2. Gun Safety (For Parents)

    Science.gov (United States)

    ... from the home of a relative or friend. Teens should never be able to get to a gun and bullets without an adult being there. People of any age who are depressed are at increased risk of suicide. If someone in the family has depression, or has had thoughts of suicide, all guns ...

  3. Guns at College.

    Science.gov (United States)

    Miller, Matthew; Hemenway, David; Wechsler, Henry

    1999-01-01

    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…

  4. Remotely controlled spray gun

    Science.gov (United States)

    Cunningham, William C. (Inventor)

    1987-01-01

    A remotely controlled spray gun is described in which a nozzle and orifice plate are held in precise axial alignment by an alignment member, which in turn is held in alignment with the general outlet of the spray gun by insert. By this arrangement, the precise repeatability of spray patterns is insured.

  5. Langerin+ dermal dendritic cells are critical for CD8+ T cell activation and IgH γ-1 class switching in response to gene gun vaccines.

    Science.gov (United States)

    Stoecklinger, Angelika; Eticha, Tekalign D; Mesdaghi, Mehrnaz; Kissenpfennig, Adrien; Malissen, Bernard; Thalhamer, Josef; Hammerl, Peter

    2011-02-01

    The C-type lectin langerin/CD207 was originally discovered as a specific marker for epidermal Langerhans cells (LC). Recently, additional and distinct subsets of langerin(+) dendritic cells (DC) have been identified in lymph nodes and peripheral tissues of mice. Although the role of LC for immune activation or modulation is now being discussed controversially, other langerin(+) DC appear crucial for protective immunity in a growing set of infection and vaccination models. In knock-in mice that express the human diphtheria toxin receptor under control of the langerin promoter, injection of diphtheria toxin ablates LC for several weeks whereas other langerin(+) DC subsets are replenished within just a few days. Thus, by careful timing of diphtheria toxin injections selective states of deficiency in either LC only or all langerin(+) cells can be established. Taking advantage of this system, we found that, unlike selective LC deficiency, ablation of all langerin(+) DC abrogated the activation of IFN-γ-producing and cytolytic CD8(+) T cells after gene gun vaccination. Moreover, we identified migratory langerin(+) dermal DC as the subset that directly activated CD8(+) T cells in lymph nodes. Langerin(+) DC were also critical for IgG1 but not IgG2a Ab induction, suggesting differential polarization of CD4(+) T helper cells by langerin(+) or langerin-negative DC, respectively. In contrast, protein vaccines administered with various adjuvants induced IgG1 independently of langerin(+) DC. Taken together, these findings reflect a highly specialized division of labor between different DC subsets both with respect to Ag encounter as well as downstream processes of immune activation.

  6. High Velocity Gas Gun

    Science.gov (United States)

    1988-01-01

    A video tape related to orbital debris research is presented. The video tape covers the process of loading a High Velocity Gas Gun and firing it into a mounted metal plate. The process is then repeated in slow motion.

  7. Gun Dynamics Laboratory

    Data.gov (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...

  8. Gun control saves lives.

    Science.gov (United States)

    Matzopoulos, Richard

    2016-05-19

    Reducing firearm mortality by means of stricter gun control is one of the most important short- to medium-term measures to address the burden of violence in South Africa, while longer-term interventions and policy measures take effect.

  9. Teen Suicide and Guns

    Science.gov (United States)

    ... Issues Listen Text Size Email Print Share Teen Suicide and Guns Page Content Article Body Protect Your ... of a passing problem, not the outcome! Teen Suicide—A Big Problem Suicide is one of the ...

  10. Gas gun dynamics

    International Nuclear Information System (INIS)

    Denny, Mark

    2013-01-01

    The mechanics and thermodynamics of one- and two-stage gas guns are developed. Very high projectile muzzle speed can be obtained by the two-stage version. The physics of simple gas guns, such as air rifles, is accessible to undergraduates and the same level of presentation is used here to understand more complex designs. Numerical solutions to the equations of motion are shown, along with insightful analytic approximations. (paper)

  11. Regulation of glutamate transporter 1 (GLT-1) gene expression by cocaine self-administration and withdrawal.

    Science.gov (United States)

    Kim, Ronald; Sepulveda-Orengo, Marian T; Healey, Kati L; Williams, Emily A; Reissner, Kathryn J

    2018-01-01

    Downregulation of the astroglial glutamate transporter GLT-1 is observed in the nucleus accumbens (NAc) following administration of multiple drugs of abuse. The decrease in GLT-1 protein expression following cocaine self-administration is dependent on both the amount of cocaine self-administered and the length of withdrawal, with longer access to cocaine and longer withdrawal periods leading to greater decreases in GLT-1 protein. However, the mechanism(s) by which cocaine downregulates GLT-1 protein remains unknown. We used qRT-PCR to examine gene expression of GLT-1 splice isoforms (GLT-1A, GLT-1B) in the NAc, prelimbic cortex (PL) and basolateral amygdala (BLA) of rats, following two widely used models of cocaine self-administration: short-access (ShA) self-administration, and the long-access (LgA) self-administration/incubation model. While downregulation of GLT-1 protein is observed following ShA cocaine self-administration and extinction, this model did not lead to a change in GLT-1A or GLT-1B gene expression in any brain region examined. Forced abstinence following ShA cocaine self-administration also was without effect. In contrast, LgA cocaine self-administration and prolonged abstinence significantly decreased GLT-1A gene expression in the NAc and BLA, and significantly decreased GLT-1B gene expression in the PL. No change was observed in NAc GLT-1A gene expression one day after LgA cocaine self-administration, indicating withdrawal-induced decreases in GLT-1A mRNA. In addition, LgA cocaine self-administration and withdrawal induced hypermethylation of the GLT-1 gene in the NAc. These results indicate that a decrease in NAc GLT-1 mRNA is only observed after extended access to cocaine combined with protracted abstinence, and that epigenetic mechanisms likely contribute to this effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. GUN4-Porphyrin Complexes Bind the ChlH/GUN5 Subunit of Mg-Chelatase and Promote Chlorophyll Biosynthesis in Arabidopsis[W

    Science.gov (United States)

    Adhikari, Neil D.; Froehlich, John E.; Strand, Deserah D.; Buck, Stephanie M.; Kramer, David M.; Larkin, Robert M.

    2011-01-01

    The GENOMES UNCOUPLED4 (GUN4) protein stimulates chlorophyll biosynthesis by activating Mg-chelatase, the enzyme that commits protoporphyrin IX to chlorophyll biosynthesis. This stimulation depends on GUN4 binding the ChlH subunit of Mg-chelatase and the porphyrin substrate and product of Mg-chelatase. After binding porphyrins, GUN4 associates more stably with chloroplast membranes and was proposed to promote interactions between ChlH and chloroplast membranes—the site of Mg-chelatase activity. GUN4 was also proposed to attenuate the production of reactive oxygen species (ROS) by binding and shielding light-exposed porphyrins from collisions with O2. To test these proposals, we first engineered Arabidopsis thaliana plants that express only porphyrin binding–deficient forms of GUN4. Using these transgenic plants and particular mutants, we found that the porphyrin binding activity of GUN4 and Mg-chelatase contribute to the accumulation of chlorophyll, GUN4, and Mg-chelatase subunits. Also, we found that the porphyrin binding activity of GUN4 and Mg-chelatase affect the associations of GUN4 and ChlH with chloroplast membranes and have various effects on the expression of ROS-inducible genes. Based on our findings, we conclude that ChlH and GUN4 use distinct mechanisms to associate with chloroplast membranes and that mutant alleles of GUN4 and Mg-chelatase genes cause sensitivity to intense light by a mechanism that is potentially complex. PMID:21467578

  13. Electromagnetic Guns versus Conventional Guns - a performance comparison

    NARCIS (Netherlands)

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

    1993-01-01

    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

  14. Fueling by coaxial plasma guns

    International Nuclear Information System (INIS)

    Marshall, J.

    1978-01-01

    The operating principles of pulsed coaxial guns are reviewed. Some problems involved with the injection of plasma beams from these guns into containment fields are described. The injection during reactor operating conditions is then discussed

  15. PHERMEX electron gun development

    International Nuclear Information System (INIS)

    Builta, L.A.; Elliott, J.C.; Moir, D.C.; Starke, T.P.; Vecere, C.A.

    1983-01-01

    The PHERMEX facility is a 50-MHz standing-wave linear accelerator. Electrons are injected, accelerated, and transported to a tungsten target where bremsstrahlung x rays are generated for flash radiography of hydrodynamic systems. The purpose of this article is to describe the progress of PHERMEX electron gun development. The goal of this program is to generate and transport a 200-ns, 1-MV, 1-kA electron beam into the first PHERMEX accelerating cavity. The standard gun is operated at a pulse voltage of 550 kV, which is the limit determined by internal breakdown of the vacuum insulator. This insulator has been redesigned, and the gun has been pulsed at 750 kV without internal breakdown. At present, the current output is not limited by voltage but by a phenomenon called pulse shortening, which occurs at a pulse voltage of approximately 650 kV. The phenomenon has been investigated and the results are presented

  16. Ion plasma electron gun

    International Nuclear Information System (INIS)

    Wakalopulos, G.

    1976-01-01

    In the disclosed electron gun positive ions generated by a hollow cathode plasma discharge in a first chamber are accelerated through control and shield grids into a second chamber containing a high voltage cold cathode. These positive ions bombard a surface of the cathode causing the cathode to emit secondary electrons which form an electron beam having a distribution adjacent to the cathode emissive surface substantially the same as the distribution of the ion beam impinging upon the cathode. After passing through the grids and the plasma discharge chamber, the electron beam exits from the electron gun via a foil window. Control of the generated electron beam is achieved by applying a relatively low control voltage between the control grid and the electron gun housing (which resides at ground potential) to control the density of the positive ions bombarding the cathode

  17. Unbalanced field RF electron gun

    Science.gov (United States)

    Hofler, Alicia

    2013-11-12

    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.

  18. Administration

    DEFF Research Database (Denmark)

    Bogen handler om den praksis, vi kalder administration. Vi er i den offentlige sektor i Danmark hos kontorfolkene med deres sagsmapper, computere, telefoner,, lovsamlinger,, retningslinier og regneark. I bogen udfoldes en mangfoldighed af konkrete historier om det administrative arbejde fra...... forskellige områder i den offentlige sektor. Hensigten er at forstå den praksis og faglighed der knytter sig til det administrative arbejde...

  19. Glue Guns: Aiming for Safety

    Science.gov (United States)

    Roy, Ken

    2010-01-01

    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…

  20. Low emittance thermionic electron guns

    International Nuclear Information System (INIS)

    Herrmannsfeldt, W.B.

    1989-01-01

    The author discusses self-field effects and external field effects for electron guns. He also discusses designs of electron guns and their uses in electron cooling systems and as an injector for electrostatic free electron lasers. He closes by looking at electron guns for linear accelerators. 20 references, 3 figures

  1. Guns, Germs and Steel

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 1. Guns, Germs and Steel - A Short History of Everybody for the Last 13,000 years. Suri Venkatachalam. Book Review Volume 6 Issue 1 January 2001 pp 84-88. Fulltext. Click here to view fulltext PDF. Permanent link:

  2. 120 Hz Gun Review

    Energy Technology Data Exchange (ETDEWEB)

    Colby, E.

    2005-01-31

    The review was held at SLAC on September 11 and 12, 2001. Presentations concerning the thermal analysis, mechanical design, integration with the laser and accelerator, general beam dynamics considerations, a load lock mechanism, and symmetric power feed options comprised the review. Slides from these presentations are available elsewhere. The review committee was charged with evaluating the 120 Hz gun design including proposed load lock and power feed options and recommending improvements. Broader evaluation of the injector as a whole (including focusing and diagnostic systems that do no impact the envelope of the gun itself) is expected to be covered in a future review and will not be commented on here. In general, the long operational experience with four generations of s-band RF guns at numerous labs worldwide has led to considerable experience in design, fabrication, and operation aspects, and provides an excellent base on which to design the higher duty factor LCLS injector. While open questions remain on obtaining the design performance from these injectors, the microwave design of the gun has reached a state of relative maturity.

  3. Gun Dealers, USA.

    Science.gov (United States)

    Duker, Laurie; And Others

    In the United States, more than 11,500 adolescents' and young adults' lives are taken each year by firearms. Although Federal law prohibits minors from purchasing handguns, they typically get them by asking someone of legal age (18 years or older) to purchase them from one of the 256,771 Federally licensed gun dealers. This pamphlet answers…

  4. Magnetron injection gun scaling

    International Nuclear Information System (INIS)

    Lawson, W.

    1988-01-01

    Existing analytic design equations for magnetron injection guns (MIG's) are approximated to obtain a set of scaling laws. The constraints are chosen to examine the maximum peak power capabilities of MIG's. The scaling laws are compared with exact solutions of the design equations and are supported by MIG simulations

  5. Practical XHV electron gun

    International Nuclear Information System (INIS)

    Urata, Tomohiro; Ishikawa, Tsuyoshi; Cho, Boklae; Oshima, Chuhei

    2008-01-01

    We have developed practical XHV chambers of a electron gun, of which the operating pressures are 1x10 -9 Pa in a stainless-steel one and 4x10 -9 Pa in a permalloy one. By mounting a noble single-atom electron source with high brightness and high spatial coherence on the electron gun including electron optics, we demonstrated highly collimated electron-beam emission: ∼80% of the total emission current entered the electron optics. This ratio was two or three orders of magnitude higher than those of the conventional electron sources. In XHV, in addition, we confirmed stable electron emission up to 20 nA, which results in the specimen current high enough for scanning electron microscopes. (author)

  6. Prospects for deflagration guns

    International Nuclear Information System (INIS)

    Cheng, D.Y.; Tripathi, P.P.; Chang, C.N.

    1978-01-01

    Deflagration is a process of fluid expansion with energy addition. Its existence in plasma physics was first discovered in the back-strapped T-tube experiments. In the coaxial plasma gun configuration the operation can be simple and yet produce a clean, high density (5 x 10 15 cm -3 ), and high kinetic energy (10 to 50 keV) collimated plasma beam. Plasma acceleration mechanism was thought to be driven by J x B force. Tapered electrodes have been used to obtain plasma beams. Scaling of the gun can be performed according to simple theory based on momentum and energy balance. Proposed plasma fueling and injection to magnetic fusion systems will be discussed

  7. RF Gun Optimization Study

    International Nuclear Information System (INIS)

    Alicia Hofler; Pavel Evtushenko

    2007-01-01

    Injector gun design is an iterative process where the designer optimizes a few nonlinearly interdependent beam parameters to achieve the required beam quality for a particle accelerator. Few tools exist to automate the optimization process and thoroughly explore the parameter space. The challenging beam requirements of new accelerator applications such as light sources and electron cooling devices drive the development of RF and SRF photo injectors. A genetic algorithm (GA) has been successfully used to optimize DC photo injector designs at Cornell University [1] and Jefferson Lab [2]. We propose to apply GA techniques to the design of RF and SRF gun injectors. In this paper, we report on the initial phase of the study where we model and optimize a system that has been benchmarked with beam measurements and simulation

  8. Mole gun injury.

    Science.gov (United States)

    Pistré, V; Rezzouk, J

    2013-09-01

    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. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. Middle Ground on Gun Control

    Science.gov (United States)

    2016-12-01

    34 Australian Institute of Criminology, July 7, 2015, http://www.aic.gov.au/ statistics /homicide/weapon.html. 0 100 200 300 400 500 600 700 Total Gun...firearms is not the business of a single Australian , so it is immeasurably easier for politicians to categorically ban types of guns because there is...not an Australian version of Smith and Wesson that is going to be put out of business . Additionally, because all of the guns in Australia are

  10. The ALS gun electronics system

    International Nuclear Information System (INIS)

    Lo, C.C.

    1993-01-01

    The ALS Gun Electronics system has been designed to accommodate the gun with a custom made socket and a high speed electronics circuit which is capable of producing single and multiple electron bunches with time jitters measured at better than 50 PS. The system generates the gated RF signal at ground level before sending it up to the 120 KV-biased gun deck via a fiber optic cable. The current pulse width as a function of grid bias, using an Eimac 8847A planar triode simulating an electron gun, was measured to show the relationship between the two parameters

  11. The ALS Gun Electronics system

    International Nuclear Information System (INIS)

    Lo, C.C.

    1993-05-01

    The ALS Gun Electronics system has been designed to accommodate gun with a custom made socket and high speed electronics circuit which is capable of producing single and multiple electron bunches with time jitters measured at better than 50 PS. The system generates the gated RF signal at ground level before sending it up to the 120 KV-biased gun deck via a fiber optic cable. The current pulse width as a function of grid bias, using an Eimac 8847A planar triode simulating an electron gun, was measured to show the relationship between the two parameters

  12. Understanding and Predicting Gun Barrel Erosion

    National Research Council Canada - National Science Library

    Johnston, Ian A

    2005-01-01

    The Australian Defence Force will soon have to contend with gun barrel erosion issues arising from the use of new low-vulnerability gun propellants, the acquisition of new ammunition and gun systems...

  13. Oral Administration of Recombinant Lactococcus lactis Expressing the Cellulase Gene Increases Digestibility of Fiber in Geese.

    Science.gov (United States)

    Zhou, Haizhu; Gao, Yunhang; Gao, Guang; Lou, Yujie

    2015-12-01

    Enhancing cellulose digestibility in animals is important for improving the utilization of forage, which can decrease the amount of food used in animal production. The aim of the present study was to achieve recombinant expression of the cellulase gene in Lactococcus lactis and evaluate the effects of oral administration of the recombinant L. lactis on fiber digestibility in geese. Cellulase (Cell) and green fluorescent protein (GFP) genes were cloned into a L. lactis expression vector (pNZ8149) to construct the recombinant expression plasmid (pNZ8149-GFP-Cell). Then, the recombinant expression plasmid was transformed into L. lactis (NZ3900) competent cells by electroporation to obtain recombinant L. lactis (pNZ8149-GFP-Cell/NZ3900) in which protein expression was induced by Nisin. Expression of GFP and Cell by the recombinant L. lactis was confirmed using SDS-PAGE, fluorescence detection, and Congo red assays. A feeding experiment showed that oral administration of pNZ8149-GFP-Cell/NZ3900 significantly increased the digestibility of dietary fiber in geese fed either a maize stalk diet or a rice chaff diet. Therefore, oral administration of recombinant L. lactis cells expressing the cellulase gene increases fiber digestibility in geese, offering a way to increase the utilization of dietary fiber in geese.

  14. Gas injected washer plasma gun

    International Nuclear Information System (INIS)

    Jain, K.K.; John, P.I.; Punithavelu, A.M.; Rao, P.P.

    1980-01-01

    A plasma gun similar in geometry to the washer plasma gun has been operated with gas injected externally. hydrogen, nitrogen and argon plasmas have been ionised and accelerated to velocities of the order of 10 7 mm s -1 and densities 10 11 mm -3 . Higher parameter range is possible with higher electrical input power. (author)

  15. Preventing gun injuries in children.

    Science.gov (United States)

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

    2015-02-01

    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. © American Academy of Pediatrics, 2015. All rights reserved.

  16. LCLS Gun Solenoid Design Considerations

    International Nuclear Information System (INIS)

    Schmerge, John

    2010-01-01

    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.

  17. Electric arc welding gun

    Science.gov (United States)

    Luttrell, Edward; Turner, Paul W.

    1978-01-01

    This invention relates to improved apparatus for arc welding an interior joint formed by intersecting tubular members. As an example, the invention is well suited for applications where many similar small-diameter vertical lines are to be welded to a long horizontal header. The improved apparatus includes an arc welding gun having a specially designed welding head which is not only very compact but also produces welds that are essentially free from rolled-over solidified metal. The welding head consists of the upper end of the barrel and a reversely extending electrode holder, or tip, which defines an acute angle with the barrel. As used in the above-mentioned example, the gun is positioned to extend upwardly through the vertical member and the joint to be welded, with its welding head disposed within the horizontal header. Depending on the design of the welding head, the barrel then is either rotated or revolved about the axis of the vertical member to cause the electrode to track the joint.

  18. Protection from radiation injury through oral administration of PF4 gene carried by attenuated salmonella

    International Nuclear Information System (INIS)

    Zhao Lihua; Liu Bin; Yu Xiaofei; Zhang Lei; Han Zhongchao

    2005-01-01

    Objective: To investigate the in vivo radiation protection effect of PF4 by oral administration of attenuated salmonella as the carrier in mice. Methods: The eukaryotic vector pIRES2-EGFP-carried PF4 gene was transferred into an aroA-autotrophic mutant of salmonella typhimurium (SL3261), which was administered orally to BALBPc mice at 1x10 8 PFu once every interval three days. At 12 hours after the third oral administration the mice were subjected to a total body irradiation (TBI) of 700 cGy by a 60 Co source. The protective effect of SL3261/PF4 was determined by detection GFP ( green fluorescence protein) expression in tissues, peripheral blood count, culture of bone marrow colony-forming cells and survival time of mice. Results: Expression of GFP could be detected in the liver, spleen, intestine, kidney, peripheral blood and bone marrow. On days 7 and 14 after irradiation, Compared to controls, there were obvious differences in number of bone marrow mononuclear cells, CFU-GM (granulocyte-macrophage colony-forming unit ) and HPP-CFC (high proliferating potential-colony-forming cells) of mice treated with SL3261/PF4 (P<0.05) as well as prolongation of the survival time. Conclusion: These data demonstrate for the first time that PF4 protects mice from TBI injury and accelerates recovery of hematopoiesis by oral administration of attenuated salmonella carrying PF4 gene. (authors)

  19. Gun Shows and Gun Violence: Fatally Flawed Study Yields Misleading Results

    Science.gov (United States)

    Hemenway, David; Webster, Daniel; Pierce, Glenn; Braga, Anthony A.

    2010-01-01

    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. PMID:20724672

  20. The Effects of Gun Ownership Rates and Gun Control Laws on Suicide Rates

    OpenAIRE

    Mark Gius

    2011-01-01

    The purpose of the present study is to determine the effects of gun control laws and gun ownership rates on state-level suicide rates. Using the most recent data on suicide rates, gun control measures, and gun ownership rates, the results of the present study suggest that states that require handgun permits have lower gun-related suicide rates, and states that have higher gun ownership rates have higher gun-related suicide rates. Regarding non-gun suicides, results suggest that stricter gun c...

  1. Gun violence trends in movies.

    Science.gov (United States)

    Bushman, Brad J; Jamieson, Patrick E; Weitz, Ilana; Romer, Daniel

    2013-12-01

    Many scientific studies have shown that the mere presence of guns can increase aggression, an effect dubbed the "weapons effect." The current research examines a potential source of the weapons effect: guns depicted in top-selling films. Trained coders identified the presence of violence in each 5-minute film segment for one-half of the top 30 films since 1950 and the presence of guns in violent segments since 1985, the first full year the PG-13 rating (age 13+) was used. PG-13-rated films are among the top-selling films and are especially attractive to youth. Results found that violence in films has more than doubled since 1950, and gun violence in PG-13-rated films has more than tripled since 1985. When the PG-13 rating was introduced, these films contained about as much gun violence as G (general audiences) and PG (parental guidance suggested for young children) films. Since 2009, PG-13-rated films have contained as much or more violence as R-rated films (age 17+) films. Even if youth do not use guns, these findings suggest that they are exposed to increasing gun violence in top-selling films. By including guns in violent scenes, film producers may be strengthening the weapons effect and providing youth with scripts for using guns. These findings are concerning because many scientific studies have shown that violent films can increase aggression. Violent films are also now easily accessible to youth (e.g., on the Internet and cable). This research suggests that the presence of weapons in films might amplify the effects of violent films on aggression.

  2. Pioglitazone administration alters ovarian gene expression in aging obese lethal yellow mice

    Directory of Open Access Journals (Sweden)

    Weber Mitch

    2008-03-01

    Full Text Available Abstract Background Women with polycystic ovary syndrome (PCOS are often treated with insulin-sensitizing agents, e.g. thiazolidinediones (TZD, which have been shown to reduce androgen levels and improved ovulatory function. Acting via peroxisome proliferator-activated receptor (PPAR gamma, TZD alter the expression of a large variety of genes. Lethal yellow (LY; C57BL/6J Ay/a mice, possessing a mutation (Ay in the agouti gene locus, exhibit progressive obesity, reproductive dysfunction, and altered metabolic regulation similar to women with PCOS. The current study was designed to test the hypothesis that prolonged treatment of aging LY mice with the TZD, pioglitazone, alters the ovarian expression of genes that may impact reproduction. Methods Female LY mice received daily oral doses of either 0.01 mg pioglitazone (n = 4 or an equal volume of vehicle (DMSO; n = 4 for 8 weeks. At the end of treatment, ovaries were removed and DNA microarrays were used to analyze differential gene expression. Results Twenty-seven genes showed at least a two-fold difference in ovarian expression with pioglitazone treatment. These included leptin, angiopoietin, angiopoietin-like 4, Foxa3, PGE1 receptor, resistin-like molecule-alpha (RELM, and actin-related protein 6 homolog (ARP6. For most altered genes, pioglitazone changed levels of expression to those seen in untreated C57BL/6J(a/a non-mutant lean mice. Conclusion TZD administration may influence ovarian function via numerous diverse mechanisms that may or may not be directly related to insulin/IGF signaling.

  3. Superconducting augmented rail gun (SARG)

    International Nuclear Information System (INIS)

    Homan, C.G.; Cummings, C.E.; Fowler, C.M.

    1986-01-01

    Superconducting augmentation consists of a superconducting coil operating in the persistent mode closely coupled magnetically with a normally conducting rail gun. A theoretical investigation of the effect of this system on a rail gun has shown that two benefits occur. Projectile velocities and launch efficiencies increase significantly depending on the magnetic coupling between the rail and augmentation circuits. Previous work evaluated an idealized system by neglecting energy dissipation effects. In this paper, the authors extend the analysis to include the neglected terms and show improved actual launch efficiencies for the SARG configuration. In this paper, the authors discuss details of projectile design in depth and present preliminary results of rail gun performance

  4. Plural beam electron gun assembly

    International Nuclear Information System (INIS)

    Stratton, M.G.

    1977-01-01

    The invention relates to a cathode ray tube plural-beam-in-line bi-potential electron gun assembly, having applied beam currents of differing levels, manifests structurally modified gun structures to effect focused beam landings at the screen that are evidenced as substantially equi-sized spots thereby providing improved resolution and brightness of the screen imagery. The structural changes embody modifications of the related focusing and accelerator electrodes of the respective guns to provide a partial telescoping arrangement for effecting the discrete placement, forming and shielding of the final focusing lenses. The three lenses so formed are in different planes in partial overlapping axial relationship

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

    NARCIS (Netherlands)

    Hordijk, A.C.; Leurs, O.

    2006-01-01

    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

  6. Reverse Ballistic Air Gun Facility

    Data.gov (United States)

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

  7. Temporal association between federal gun laws and the diversion of guns to criminals in Milwaukee.

    Science.gov (United States)

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

    2012-02-01

    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.

  8. Shot-gun proteome and transcriptome mapping of the jujube floral organ and identification of a pollen-specific S-locus F-box gene

    Directory of Open Access Journals (Sweden)

    Ruihong Chen

    2017-07-01

    Full Text Available The flower is a plant reproductive organ that forms part of the fruit produced as the flowering season ends. While the number and identity of proteins expressed in a jujube (Ziziphus jujuba Mill. flower is currently unknown, integrative proteomic and transcriptomic analyses provide a systematic strategy of characterizing the floral biology of plants. We conducted a shotgun proteomic analysis on jujube flowers by using a filter-aided sample preparation tryptic digestion, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS. In addition, transcriptomics analyses were performed on HiSeq2000 sequencers. In total, 7,853 proteins were identified accounting for nearly 30% of the ‘Junzao’ gene models (27,443. Genes identified in proteome generally showed higher RPKM (reads per kilobase per million mapped reads values than undetected genes. Gene ontology categories showed that ribosomes and intracellular organelles were the most dominant classes and accounted for 17.0% and 14.0% of the proteome mass, respectively. The top-ranking proteins with iBAQ >1010 included non-specific lipid transfer proteins, histones, actin-related proteins, fructose-bisphosphate aldolase, Bet v I type allergens, etc. In addition, we identified one pollen-specificity S-locus F-box-like gene located on the same chromosome as the S-RNase gene. Both of these may activate the behaviour of gametophyte self-incompatibility in jujube. These results reflected the protein profile features of jujube flowers and contributes new information important to the jujube breeding system.

  9. NASA-Ames vertical gun

    Science.gov (United States)

    Schultz, P. H.

    1984-01-01

    A national facility, the NASA-Ames vertical gun range (AVGR) has an excellent reputation for revealing fundamental aspects of impact cratering that provide important constraints for planetary processes. The current logistics in accessing the AVGR, some of the past and ongoing experimental programs and their relevance, and the future role of this facility in planetary studies are reviewed. Publications resulting from experiments with the gun (1979 to 1984) are listed as well as the researchers and subjects studied.

  10. State Gun Law Environment and Youth Gun Carrying in the United States.

    Science.gov (United States)

    Xuan, Ziming; Hemenway, David

    2015-11-01

    Gun violence and injuries pose a substantial threat to children and youth in the United States. Existing evidence points to the need for interventions and policies for keeping guns out of the hands of children and youth. (1) To examine the association between state gun law environment and youth gun carrying in the United States, and (2) to determine whether adult gun ownership mediates this association. This was a repeated cross-sectional observational study design with 3 years of data on youth gun carrying from US states. The Youth Risk Behavior Survey comprises data of representative samples of students in grades 9 to 12 from biennial years of 2007, 2009, and 2011. We hypothesized that states with more restrictive gun laws have lower rates of youth gun carrying, and this association is mediated by adult gun ownership. State gun law environment as measured by state gun law score. Youth gun carrying was defined as having carried a gun on at least 1 day during the 30 days before the survey. In the fully adjusted model, a 10-point increase in the state gun law score, which represented a more restrictive gun law environment, was associated with a 9% decrease in the odds of youth gun carrying (adjusted odds ratio [AOR], 0.91 [95% CI, 0.86-0.96]). Adult gun ownership mediated the association between state gun law score and youth gun carrying (AOR, 0.94 [ 95% CI, 0.86-1.01], with 29% attenuation of the regression coefficient from -0.09 to -0.07 based on bootstrap resampling). More restrictive overall gun control policies are associated with a reduced likelihood of youth gun carrying. These findings are relevant to gun policy debates about the critical importance of strengthening overall gun law environment to prevent youth gun carrying.

  11. State Gun Policy and Cross-State Externalities: Evidence from Crime Gun Tracing

    OpenAIRE

    Brian Knight

    2013-01-01

    This paper provides a theoretical and empirical analysis of cross-state externalities associated with gun regulations in the context of the gun trafficking market. Using gun tracing data, which identify the source state for crime guns recovered in destination states, we find that firearms in this market tend to flow from states with weak gun laws to states with strict gun laws, satisfying a necessary condition for the existence of cross-state externalities in the theoretical model. We also fi...

  12. The case for moderate gun control.

    Science.gov (United States)

    DeGrazia, David

    2014-03-01

    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.

  13. Results of the AFWL deflagration gun experiments

    International Nuclear Information System (INIS)

    Hackett, K.E.; Baker, W.L.; Beason, J.D.

    1987-01-01

    The snowplow and deflagration modes of coaxial plasma gun operation have been experimentally investigated and computationally simulated at the Air Force Weapons Laboratory. The snowplow mode occurs when the gun is prefilled to a uniform gas density. The initial breakdown forms near the insulator at the gun breech. It heats the gas and creates a shock wave that travels down the gun, ionizing gas and producing a thin current sheath that travels just behind the shock front. The shock front piles up the gas in front of itself as it moves down the gun - hence the name ''snowplow''. Deflagration occurs when gas is injected into an evacuated gun so that the initial breakdown forms as the gas fills the gun. The ionized gas is accelerated into the vacuum region carrying current and magnetic field with it. A quasi-stationary diffuse discharge develops. Gas still entering the gun is processed through the deflagrating discharge and accelerated out the gun muzzle

  14. Large Bore Powder Gun Qualification (U)

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-02

    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.

  15. Lake Wobegon’s Guns: Overestimating Our Gun-Related Competences

    Directory of Open Access Journals (Sweden)

    Emily Stark

    2016-02-01

    Full Text Available The Lake Wobegon Effect is a general tendency for people to overestimate their own abilities. In this study, the authors conducted a large, nationally-representative survey of U.S. citizens to test whether Americans overestimate their own gun-relevant personality traits, gun safety knowledge, and ability to use a gun in an emergency. The authors also tested how gun control attitudes, political identification, gender, and gun experience affect self-perceptions. Consistent with prior research on the Lake Wobegon Effect, participants overestimated their gun-related competencies. Conservatives, males, and pro-gun advocates self-enhanced somewhat more than their counterparts but this effect was primarily due to increased gun experience among these participants. These findings are important to policymakers in the area of gun use, because overconfidence in one’s gun-related abilities may lead to a reduced perceived need for gun training.

  16. Heavy duty plasma spray gun

    International Nuclear Information System (INIS)

    Irons, G.C.; Klein, J.F.; Lander, R.D.; Thompson, H.C.; Trapani, R.D.

    1984-01-01

    A heavy duty plasma spray gun for extended industrial service is disclosed. The gun includes a gas distribution member made of a material having a coefficient of expansion different from that of the parts surrounding it. The gas distribution member is forcibly urged by a resilient member such as a coiled spring against a seal so as to assure the plasma gas is introduced into the gun arc in a manner only defined by the gas distribution member. The gun has liquid cooling for the nozzle (anode) and the cathode. Double seals are provided between the coolant and the arc region and a vent is provided between the seals which provides an indication when a seal has failed. Some parts of the gun are electrically isolated from others by an intermediate member which is formed as a sandwich of two rigid metal face pieces and an insulator disposed between them. The metal face pieces provide a rigid body to attach the remaining parts in proper alignment therewith

  17. Development of coaxial rotating-plasma gun

    International Nuclear Information System (INIS)

    Ikehata, Takashi; Tanabe, Toshio; Mase, Hiroshi

    1985-01-01

    A rotating-plasma gun has been devised to produce plasma streams with higher rotational velocities. The working mechanism of the gun and the results of a preliminary experiment have been described. (author)

  18. ATA injector-gun calculations

    International Nuclear Information System (INIS)

    Paul, A.C.

    1981-01-01

    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

  19. Plasma focusing in coaxial gun

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.; El-Khalafawy, T.

    1986-01-01

    A capacitor bank has been discharged between two coaxial electrodes of 6.6 cm outer diameter, 3.2 cm inner diameter and length of 31.5 cm. filled with hydrogen gas at pressure of 310 μHg. Results show that, the axial and radial plasma current reach a maximum value at a position adjacent to the gun muzzle, at which the plasma focus occurs. The measurement of the electron temperature and density and azimuthal electric field along the axis of the expansion chamber, gives a maximum value at z∼18 cm from the gun muzzle, while the axial plasma current and velocity has a minimum value at that position. These results indicate that a second point of a plasma focus has been formed at z∼18 cm from the gun muzzle, along the axis of the expansion chamber

  20. Lasers for RF guns: Proceedings

    International Nuclear Information System (INIS)

    Srinivasan-Rao, T.

    1994-01-01

    In the past decade, laser driven RF guns have matured from a device under development to a proven source for high brightness and low emittance electron beams. The reliability of the electron beam from these sources is dictated by the laser system that drives it. In addition, capabilities of the laser systems play a vital role in the design of the electron source for future machines such as the TESLA and NLC. The purpose of this workshop was to provide a forum for discussing the design criteria for the laser systems so that the reliability of the existing sources could be improved and the future machines could be serviced. The Workshop brought together experts in RF Guns, accelerators, and lasers, from both the commercial and academic community. Most of the presentations, discussions and conclusions at the workshop are included in these proceedings. The contents are divided into three sections, Section I contains the invited talks that outline the requirements of the RF Guns and the capabilities of the laser systems to meet these requirements. Section II includes most of the papers presented in the poster session. These papers describe various laser systems used with electron guns, schemes to modify the laser beam profile to optimize the electron bunch, and computer simulations of electron trajectories. Section III contains the summaries of the working groups. As the summary section indicates, with sufficient feed back systems, the electron gun could be made to operate reliably with minimum downtime, using commercial lasers currently available. The design of laser systems for future colliders depend critically on the choice of the cathode m the gun and its efficiency. Tentative designs of laser systems for the TESLA test facility and LCLS had been drawn assuming a copper cathode. Using a more efficient cathode will ease the energy requirement of the laser and simplify the design. The individual papers have been cataloged separately elsewhere

  1. Automatic targeting of plasma spray gun

    International Nuclear Information System (INIS)

    Abbatiello, L.A.; Neal, R.E.

    1978-01-01

    A means for monitoring the material portion in the flame of a plasma spray gun during spraying operations is described. A collimated detector, sensitive to certain wavelengths of light emission, is used to locate the centroid of the material with each pass of the gun. The response from the detector is then relayed to the gun controller to be used to automatically realign the gun

  2. Automatic targeting of plasma spray gun

    Science.gov (United States)

    Abbatiello, Leonard A.; Neal, Richard E.

    1978-01-01

    A means for monitoring the material portion in the flame of a plasma spray gun during spraying operations is provided. A collimated detector, sensitive to certain wavelengths of light emission, is used to locate the centroid of the material with each pass of the gun. The response from the detector is then relayed to the gun controller to be used to automatically realign the gun.

  3. Fueling by coaxial plasma guns

    International Nuclear Information System (INIS)

    Marshall, J.

    1977-01-01

    A review of the operational characteristics of ''snowplow'' and ''deflagration'' coaxial plasma guns is given. The injection of these plasmas into containment fields is discussed. The effect of a background plasma on low-beta injection is mentioned. The use of high-beta injection for reactor plasmas is described

  4. Flit-gun sprayer characteristics

    Directory of Open Access Journals (Sweden)

    J. R. Brown

    1998-05-01

    Full Text Available Six flit-gun sprayers were tested for possible use in mosquito adulticide programs where inexpensive nonmotorized application technology may be required. An analysis of variance for differences in droplets or = 48 µ, droplets/cm², volume median diameters, and mosquito mortality is provided. As shown by these data, good results can be achieved with this equipment.

  5. Developments in electron gun simulation

    Science.gov (United States)

    Herrmannsfeldt, W. B.

    1997-01-01

    This paper will discuss the developments in the electron gun simulation programs that are based on EGUN and its derivatives and supporting programs. Much of the code development has been inspired by technology changes in computer hardware; the implications on EGN2 of this evolution will be discussed. Some examples and a review of the capabilities of the EGUN family will be described.

  6. Developments in electron gun simulation

    International Nuclear Information System (INIS)

    Herrmannsfeldt, W.B.

    1994-05-01

    This paper will discuss the developments in the electron gun simulation programs that are based on EGUN and its derivatives and supporting programs. Much of the code development has been inspired by technology changes in computer hardware; the implications on EGN2 of this evolution will be discussed. Some examples and a review of the capabilities of the EGUN family will be described

  7. Characteristics of the ETA gun

    International Nuclear Information System (INIS)

    Paul, A.C.; Neil, V.K.; Craig, G.D.; Fessenden, T.J.

    1981-01-01

    The Experimental Test Accelerator (ETA) is a linear induction device consisting of a 2.5-MV electron gun and ten 0.25-MV accelerating units designed to produce a 10-kA beam of electrons at 5 MeV. Calculations with the computer code EBQ as well as experimental measurements indicate that the current produced by the gun is limited by two phenomena. The first arises from the variation of particle energy with time during the pulse. Only particles with energy within a limited range can be transported by the focusing coils in the gun: therefore the variation of the gun's output current with time is determined by the coil settings. The second effect results from a collective interaction at sufficiently large current to cause a virtual cathode to form a few centimeters past the extraction grid. Operation in this regime results in greatly increased beam emittance and poor beam transport through the accelerator. Results of the code calculations are compared with experimental data and found to be in good agreement. (author)

  8. Electric rail gun application to space propulsion

    International Nuclear Information System (INIS)

    Barber, J.P.

    1979-01-01

    The paper examines the possibility of using the DC electric gun principles as a space vehicle propulsion system, capable of producing intermediate thrust levels. The application of an electromagnetic launch technique, called the DC electric rail gun, to the space propulsion concept of O'Neill, is examined. It is determined that the DC electric rail gun offers very high projectile accelerations and a very significant potential for reducing the size and mass of a reaction motor for space application. A detailed description of rail gun principles is given and some simple expressions for the accelerating force, gun impedance, power supply requirements, and system performance are discussed

  9. Electron gun for technological linear accelerator

    International Nuclear Information System (INIS)

    Khodak, I.V.; Kushnir, V.A.; Mirochenko, V.V.; Stepin, D.L.; Zavada, L.M.

    2000-01-01

    The work is purposed to the design of diode electron gun for powerful technologic electron linac and to experimental investigations of the beam parameters at the gun exit.The gun feature is the quick cathode replacement.This is very impotent for operating of the accelerator.The gun optics and beam parameters were calculated using the EGUN code.Beam parameters were investigated as at the special test stand so as component of the linac injector.The gun produces the beam current of 2 A at the anode voltage 25 kV.Measured beam parameters correspond to calculated results

  10. RF Design of the LCLS Gun

    International Nuclear Information System (INIS)

    Limborg-Deprey, C.

    2010-01-01

    Final dimensions for the LCLS RF gun are described. This gun, referred to as the LCLS gun, is a modified version of the UCLA/BNL/SLAC 1.6 cell S-Band RF gun (1), referred to as the prototype gun. The changes include a larger mode separation (15 MHz for the LCLS gun vs. 3.5 MHz for the prototype gun), a larger radius at the iris between the 2 cells, a reduced surface field on the curvature of the iris between the two cells, Z power coupling, increased cooling channels for operation at 120 Hz, dual rf feed, deformation tuning of the full cell, and field probes in both cells. Temporal shaping of the klystron pulse, to reduce the average power dissipated in the gun, has also been adopted. By increasing the mode separation, the amplitude of the 0-mode electric field on the cathode decreases from 10% of the peak on axis field for the prototype gun to less than 3% for the LCLS gun for the steady state fields. Beam performance is improved as shown by the PARMELA simulations. The gun should be designed to accept a future load lock system. Modifications follow the recommendations of our RF review committee (2). Files and reference documents are compiled in Section IV.

  11. Identification and molecular characterization of the second Chlamydomonas gun4 mutant, gun4-II [v2; ref status: indexed, http://f1000r.es/1id

    Directory of Open Access Journals (Sweden)

    Phillip B Grovenstein

    2013-07-01

    Full Text Available The green micro-alga Chlamydomonas reinhardtii is an elegant model organism to study oxygenic photosynthesis. Chlorophyll (Chl and heme are major tetrapyrroles that play an essential role in photosynthesis and respiration. These tetrapyrroles are synthesized via a common branched pathway that involves mainly enzymes, encoded by nuclear genes. One of the enzymes in the pathway is Mg chelatase (MgChel. MgChel catalyzes insertion of Mg2+ into protoporphyrin IX (PPIX, proto to form Magnesium-protoporphyrin IX (MgPPIX, Mgproto, the first biosynthetic intermediate in the Chl branch. The GUN4 (genomes uncoupled 4 protein is not essential for the MgChel activity but has been shown to significantly stimulate its activity. We have isolated a light sensitive mutant, 6F14, by random DNA insertional mutagenesis. 6F14 cannot tolerate light intensities higher than 90-100 μmol photons m-2 s-1. It shows a light intensity dependent progressive photo-bleaching. 6F14 is incapable of photo-autotrophic growth under light intensity higher than 100 μmol photons m-2 s-1. PCR based analyses show that in 6F14 the insertion of the plasmid outside the GUN4 locus has resulted in a genetic rearrangement of the GUN4 gene and possible deletions in the genomic region flanking the GUN4 gene. Our gun4 mutant has a Chl content very similar to that in the wild type in the dark and is very sensitive to fluctuations in the light intensity in the environment unlike the earlier identified Chlamydomonas gun4 mutant. Complementation with a functional copy of the GUN4 gene restored light tolerance, Chl biosynthesis and photo-autotrophic growth under high light intensities in 6F14. 6F14 is the second gun4 mutant to be identified in C. reinhardtii. Additionally, we show that our two gun4 complements over-express the GUN4 protein and show a higher Chl content per cell compared to that in the wild type strain.

  12. Electronic emission and electron guns

    International Nuclear Information System (INIS)

    Roy, Amitava

    2010-01-01

    This paper reviews the process of electron emission from metal surface. Although electrons move freely in conductors like metals, they normally do not leave the metal without some manipulation. In fact, heating and bombardment are the two primary ways in which electrons are emitted through the use of a heating element behind the cathode (termed thermionic emission) or as a result of bombardment with a beam of electrons, ions, or metastable atoms (termed secondary emission). Another important emission mechanism called Explosive Electron Emission (EEE) is also often used in various High Voltage Pulse Power Systems to generate very high current (few hundreds of kA) pulsed electron beams. The electron gun is the device in that it shoots off a continuous (or pulsed) stream of electrons. A brief idea about the evolution of the electron gun components and their basis of functioning are also discussed. (author)

  13. Effects of Exposure to Gun Violence in Movies on Children's Interest in Real Guns.

    Science.gov (United States)

    Dillon, Kelly P; Bushman, Brad J

    2017-11-01

    More US children die by accidental gun use than children in other developed countries. One factor that can influence children's interest in guns is exposure to media containing guns. To test whether children who see a movie containing guns will handle a real gun longer and will pull the trigger more times than children who see the same movie not containing guns. One hundred four children aged 8 to 12 years recruited through advertisements were randomly assigned in pairs to watch a 20-minute PG-rated movie containing or not containing guns in a university laboratory. Children then played with toys and games in a room for 20 minutes while being video recorded. A cabinet in the room contained a real (disabled) gun with a sensor counting trigger pulls. Recordings were coded for the time spent holding the gun and in aggressive play. Data were collected from July 15, 2015, through January 1, 2016, and analyzed using generalized estimating equations (Tweedie log-link for time spent holding the gun; Poisson log-link for pulling the trigger). The 2 main outcomes were time spent holding the gun and the number of trigger pulls. Control variables included sex, age, trait aggressiveness, exposure to violent media, interest in guns, and number of guns at home. Among the 104 study participants (62 boys [59.6%] and 42 girls [40.4%]; mean (SD) age, 9.9 [1.5] years), the adjusted median number of trigger pulls among children who saw the movie containing guns was 2.8 (interquartile range [IQR], 0.2-2.8) compared with 0.01 (IQR, 0.01-0.2) among children who saw the movie not containing guns (adjusted odds ratio, 22.3; 95% CI, 6.0-83.4; P gun among children who saw a movie containing guns was 53.1 (IQR, 35.5-53.1) compared with 11.1 (IQR, 10.7-16.7) among children who saw the movie not containing guns (adjusted odds ratio, 3.0; 95% CI, 0.9-9.9; P = .07). Qualitative analyses on 4 pairs from each condition found that children who saw the movie containing guns also played more

  14. Dynamic changes in prefrontal cortex gene expression following lysergic acid diethylamide administration.

    Science.gov (United States)

    Nichols, Charles D; Garcia, Efrain E; Sanders-Bush, Elaine

    2003-03-17

    Lysergic acid diethylamide (LSD) is a psychoactive drug that transiently alters human perception, behavior, and mood at extremely low doses. Certain aspects of the behavior elicited by acute doses of LSD closely resemble symptoms of mental disorders such as schizophrenia. Characterizing gene expression profiles after LSD will be important for understanding how it alters behavior, and will lead to novel insights into disorders, such as schizophrenia, whose behavioral symptoms resemble the temporary effects of hallucinogenic drugs. We previously identified a small collection of genes within the rat prefrontal cortex that respond to LSD. Many of the products of these genes are involved in the process of synaptic plasticity. In the current report, we present a detailed analysis of the expression of these genes within the brain using RNase protection analysis. We find that the gene response to LSD is quite dynamic. The expression of some genes increases rapidly and decreases rapidly, while other genes change more gradually. Dose-response studies show two classes of expression; gene expression maximally stimulated at lower doses, versus gene expression that continues to rise at the higher doses. The role of the 5-HT(1A) and 5-HT(2A) receptor in mediating the increases in gene expression was examined in a series of experiments using receptor specific antagonists. Most expression increases were due to activation of the 5-HT(2A) receptor, however expression of two genes had neither a 5-HT(1A) nor a 5-HT(2A) receptor component.

  15. Guns, Suicide, COPD and Sleep

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2018-03-01

    Full Text Available No abstract available. Article truncated at 150 words. Within the past year two tragic events, the shootings in Las Vegas and Florida have renewed the debate about guns. The politics and the money that fuels the political debate have sharply divided politicians. As tragic as these mass shootings are, deaths by suicide far outnumber the loss of live in these shootings. In 2014 suicide was the tenth most common cause of death with 42,826 lives lost (1. Half of the suicides were by firearm (21,386. The medical profession has traditionally been reluctant to speak about politically sensitive issues such as abortion, sexuality, and guns. However, beginning early in this millennium some medical societies such as the American Academy of Pediatrics, the US Preventative Services Task Force and even the Department of Veterans Affairs were suggesting physicians ask patients about gun behavior, but a few patients complained (2-5. There were some anecdotal reports of patients feeling “pressured” to answer …

  16. Self-bunching electron guns

    CERN Document Server

    Mako, F; Weilhammer, Peter

    1999-01-01

    We report on three electron gun projects that are aimed at power tube and injector applications. The purpose of the work is to develop robust electron guns which produce self-bunched, high-current-density beams. We have demonstrated cold emission, long life, and tolerance to contamination. The cold emission process is based on secondary electron emission. FMT has studied this resonant bunching process which gives rise to high current densities (0.01-5 kA/cm/sup 2/), high charge bunches (up to 100 nC/bunch), and short pulses (1-100 ps) for frequencies from 1 to 12 GHz. The beam pulse width is nominally ~5% of the RF period. The first project is the L-Band Micro-Pulse Gun (MPG). Measurements show ~40 ps long microbunches at ~20 A/cm/sup 2/ without contamination due to air exposure. Lifetime testing has been carried out for about 18 months operating at 1.25 GHz for almost 24 hours per day at a repetition rate of 300 Hz and 5 mu s-long macro- pulses. About 5.8*10/sup 13/ micro-bunches or 62,000 coulombs have pass...

  17. X-Band RF Gun Development

    International Nuclear Information System (INIS)

    Vlieks, A.E.

    2012-01-01

    In support of the MEGa-ray program at LLNL and the High Gradient research program at SLAC, a new X-band multi-cell RF gun is being developed. This gun, similar to earlier guns developed at SLAC for Compton X-ray source program, will be a standing wave structure made of 5.5 cells operating in the pi mode with copper cathode. This gun was designed following criteria used to build SLAC X-band high gradient accelerating structures. It is anticipated that this gun will operate with surface electric fields on the cathode of 200 MeV/m with low breakdown rate. RF will be coupled into the structure through a final cell with symmetric duel feeds and with a shape optimized to minimize quadrupole field components. In addition, geometry changes to the original gun, operated with Compton X-ray source, will include a wider RF mode separation, reduced surface electric and magnetic fields.

  18. Oxycodone Self-Administration Induces Alterations in Expression of Integrin, Semaphorin and Ephrin Genes in the Mouse Striatum

    Directory of Open Access Journals (Sweden)

    Vadim Yuferov

    2018-06-01

    Full Text Available Oxycodone is one a commonly used medication for pain, and is also a widely abused prescription opioid, like other short-acting MOPr agonists. Neurochemical and structural adaptations in brain following chronic MOPr-agonist administration are thought to underlie pathogenesis and persistence of opiate addiction. Many axon guidance molecules, such as integrins, semaphorins, and ephrins may contribute to oxycodone-induced neuroadaptations through alterations in axon-target connections and synaptogenesis, that may be implicated in the behaviors associated with opiate addiction. However, little is known about this important area. The aim of this study is to investigate alterations in expression of selected integrin, semaphorin, ephrins, netrin, and slit genes in the nucleus accumbens (NAc and caudate putamen (CPu of mice following extended 14-day oxycodone self-administration (SA, using RNAseq.Methods: Total RNA from the NAc and CPu were isolated from adult male C57BL/6J mice within 1 h after the last session of oxycodone in a 14-day self-administration paradigm (4h/day, 0.25 mg/kg/infusion, FR1 or from yoked saline controls. Gene expressions were examined using RNA sequencing (RNA-Seq technology. RNA-Seq libraries were prepared using Illumina's TruSeq® Stranded Total RNA LT kit. The reads were aligned to the mouse reference genome (version mm10 using STAR. DESeq2 was applied to the counts of protein coding genes to estimate the fold change between the treatment groups. False Discovery Rate (FDR q < 0.1 were used to select genes that have a significant expression change. For selection of a subset of genes related to axon guidance pathway, REACTOME was used.Results: Among 38 known genes of the integrin, semaphorin, and ephrin gene families, RNA-seq data revealed up-regulation of six genes in the NAc: heterodimer receptor, integrins Itgal, Itgb2, and Itgam, and its ligand semaphorin Sema7a, two semaphorin receptors, plexins Plxnd1 and Plxdc1. There was

  19. The polarized electron gun for the SLC

    International Nuclear Information System (INIS)

    Schultz, D.C.; Clendenin, J.; Frisch, J.; Hoyt, E.; Klaisner, L.; Woods, M.; Wright, D.; Zolotorev, M.

    1992-03-01

    A new polarized electron gun for use on the SLC at SLAC has been built and tested. It is a diode gun with a laser driven GaAs photocathode. It is designed to provide short (2ns) pulses of 10 A at 160 kV at 120 Hz. The design features of the gun and results from a testing program on a new and dedicated beam line are presented. Early results from operation on the SLC will also be shown

  20. Rate control for electron gun evaporation

    International Nuclear Information System (INIS)

    Schellingerhout, A.J.G.; Janocko, M.A.; Klapwijk, T.M.; Mooij, J.E.

    1989-01-01

    Principles for obtaining high-quality rate control for electron gun evaporation are discussed. The design criteria for rate controllers are derived from this analysis. Results are presented which have been obtained with e-guns whose evaporation rate is controlled by a Wehnelt electrode or by sweeping of the electron beam. Further improvements of rate stability can be obtained by improved design of e-guns and power supplies

  1. RF gun using laser-triggered photocathode

    International Nuclear Information System (INIS)

    Akiyama, H.; Otake, Y.; Naito, T.; Takeuchi, Y.; Yoshioka, M.

    1992-01-01

    An RF gun using laser-triggered photocathode has many advantages as an injector of the linear colliders since it can generate a low emittance and high current pulsed beam. The experimental facility for the RF gun, such as an RF system, a laser system and a photocathode have been fabricated to study the fundamental characteristics. The dynamics of the RF gun has also studied by the 1D sheet beam model. (author)

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

    Science.gov (United States)

    O'Brien, Kerry; Forrest, Walter; Lynott, Dermot; Daly, Michael

    2013-01-01

    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. 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. 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). 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.

  3. 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.

  4. Racism, Gun Ownership and Gun Control: Biased Attitudes in US Whites May Influence Policy Decisions

    OpenAIRE

    O?Brien, Kerry; Forrest, Walter; Lynott, Dermot; Daly, Michael

    2013-01-01

    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 wh...

  5. Racism, Gun Ownership and Gun Control: Biased Attitudes in US Whites May Influence Policy Decisions

    Science.gov (United States)

    O’Brien, Kerry; Forrest, Walter; Lynott, Dermot; Daly, Michael

    2013-01-01

    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. PMID:24204867

  6. Bayesian models and meta analysis for multiple tissue gene expression data following corticosteroid administration

    Directory of Open Access Journals (Sweden)

    Kelemen Arpad

    2008-08-01

    Full Text Available Abstract Background This paper addresses key biological problems and statistical issues in the analysis of large gene expression data sets that describe systemic temporal response cascades to therapeutic doses in multiple tissues such as liver, skeletal muscle, and kidney from the same animals. Affymetrix time course gene expression data U34A are obtained from three different tissues including kidney, liver and muscle. Our goal is not only to find the concordance of gene in different tissues, identify the common differentially expressed genes over time and also examine the reproducibility of the findings by integrating the results through meta analysis from multiple tissues in order to gain a significant increase in the power of detecting differentially expressed genes over time and to find the differential differences of three tissues responding to the drug. Results and conclusion Bayesian categorical model for estimating the proportion of the 'call' are used for pre-screening genes. Hierarchical Bayesian Mixture Model is further developed for the identifications of differentially expressed genes across time and dynamic clusters. Deviance information criterion is applied to determine the number of components for model comparisons and selections. Bayesian mixture model produces the gene-specific posterior probability of differential/non-differential expression and the 95% credible interval, which is the basis for our further Bayesian meta-inference. Meta-analysis is performed in order to identify commonly expressed genes from multiple tissues that may serve as ideal targets for novel treatment strategies and to integrate the results across separate studies. We have found the common expressed genes in the three tissues. However, the up/down/no regulations of these common genes are different at different time points. Moreover, the most differentially expressed genes were found in the liver, then in kidney, and then in muscle.

  7. Operation of the APS rf gun

    International Nuclear Information System (INIS)

    Lewellen, J. W.

    1998-01-01

    The Advanced Photon Source (APS) has a thermionic-cathode rf gun system capable of providing beam to the APS linac. The gun system consists of a 1.6-cell thermionic-cathode rf gun, a fast kicker for beam current control, and an alpha magnet for bunch compression and injection into the APS linac line. This system is intended for use both as an injector for positron creation, and as a first beam source for the Low-Energy Undulator Test Line (LEUTL) project [1]. The first measured performance characteristics of the gun are presented.

  8. Conceptual Design for CLIC Gun Pulser

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-08

    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.

  9. Hard-driven rail-gun tests

    International Nuclear Information System (INIS)

    Peterson, D.R.; Adams, D.F.; Cummings, C.E.; Fowler, C.M.; Kerrisk, J.F.; Marsh, S.P.; Parker, J.V.

    1983-01-01

    A number of prototype rail-gun designs have been tested, powered by explosive magnetic flux compression generators. Peak currents as high as 1.3 MA were delivered. Rail guns with 50-mm-thick Kevlar fiberwound structural shells were able to survive these high currents with minimum mechanical damage and were refired after enlarging the bores 0.2 to 0.4 mm to remove arc damage. In some tests, mechanical damage occurred that was apparently caused by the rebound of the gun after firing. Although the Kevlar shells had more than adequate strength, they appeared to lack sufficient stiffness, allowing excessive deflections. The use of a steel structural shell with a Kevlar sleeve was an improvement. Intrusion into the seams of the rail guns and condensation of material from the plasma armature were observed. Improved sealing of seams is indicated. In some cases, we suspect maldistribution of current within the gun; that is, not all the current delivered to the breech of the gun seemed to reach the plasma armature. Experiments are being designed to quantify the effects discussed. Rail guns of advanced design are being fabricated. An 18-g titanium projectile was accelerated to 2.4 km/s in a 16-mm-round-bore, 0.6-m-long gun, 4-6 g polycarbonate projectiles were accelerated to 3.5 km/s in 13-mm-square-bore, 1.2-m-long rail guns. All tests were conducted at atmospheric pressure

  10. Gun power source for electron gun of 3 MeV DC accelerator

    International Nuclear Information System (INIS)

    Dewangan, S.; Sharma, D.K.; Nanu, K.

    2011-01-01

    In DC electron beam accelerator electron gun is situated at high voltage terminal which requires constant power irrespective of beam energy. Floating power source is required for gun. This paper describes the scheme of static gun power source derived from parallel coupled voltage multiplier column. (author)

  11. Theoretical investigation of a travelling-wave rf gun

    International Nuclear Information System (INIS)

    Gao, J.

    1991-12-01

    A travelling-wave type rf gun (TW gun) is investigated theoretically. Analytical formulae concerning energy gain, energy spread, and transverse emittance are derived. After showing the corresponding formulae for the standing-wave rf gun (SW gun), comparisons are made between the two types of rf gun. Finally, some numerical results are calculated to demonstrate further the behaviours of the TW gun, and to compare with those from analytical formulae. (author) 11 refs.; 27 figs

  12. Experimental studies of coaxial plasma gun current

    International Nuclear Information System (INIS)

    Price, D.W.

    1988-01-01

    In this investigation of a coaxial plasma gun, plasma sheath currents and related behavior are examined. Plasma behavior in the gun affects gun characteristics. Plasma gun applications are determined by the plasma behavior. The AFWL PUFF capacitor bank (72 μF, 29 nH, 120 kV) drives the plasma gun using a deuterium fill gas. The gas breakdown site is isolated from the dielectric/vacuum interface in the AFWL system. Two gas values deliver gas in the system. The first delivers gas from the gun breech and the second optional valve delivers gas to the gun muzzle. Currents and voltages are measured by Rogowski coils, B probes and capacitive voltage probes. A O-D slug model is used to predict the current, inductance, gun voltage and plasma sheath velocity. The slug model assumes the sheath transits the gun with all mass in the sheath. In the snowplow mode, the plasma sheath is thin with a sharp current rise and drop. Our system operated in a transition mode between the snowplow and deflagration modes with early snowplow behavior and late deflagration behavior. Neutrons are produced in a plasma pinch at the gun muzzle, indicating snowplow behavior. The slug theory models overall gun behavior to experimental accuracy. Experimental results are compared to four theories for plasma sheath velocities: the Alfven collisionally limited model, the Rosenbluth model, the Fishbine saturated model and a single particle drift model. Experimental velocities vary from 10 5 to 10 6 m/s. Only the single particle drift and the slug model calculations are of the right magnitude (8 x 10 5 m/s). The Fishbine and the Rosenbluth models predict slower velocities (2 x 10 5 m/s). The Alfven model is not applicable to this system

  13. From gun politics to self-defense politics: a feminist critique of the great gun debate.

    Science.gov (United States)

    Carlson, Jennifer D

    2014-03-01

    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.

  14. Self-bunching electron guns

    Science.gov (United States)

    Mako, Frederick M.; Len, L. K.

    1999-05-01

    We report on three electron gun projects that are aimed at power tube and injector applications. The purpose of the work is to develop robust electron guns which produce self-bunched, high-current-density beams. We have demonstrated, in a microwave cavity, self-bunching, cold electron emission, long life, and tolerance to contamination. The cold process is based on secondary electron emission. FMT has studied using simulation codes the resonant bunching process which gives rise to high current densities (0.01-5 kA/cm2), high charge bunches (up to 500 nC/bunch), and short pulses (1-100 ps) for frequencies from 1 to 12 GHz. The beam pulse width is nominally ˜5% of the rf period. The first project is the L-Band Micro-Pulse Gun (MPG). Measurements show ˜40 ps long micro-bunches at ˜20 A/cm2 without contamination due to air exposure. Lifetime testing has been carried out for about 18 months operating at 1.25 GHz for almost 24 hours per day at a repetition rate of 300 Hz and 5 μs-long macro-pulses. Approximately 5.8×1013 micro-bunches or 62,000 coulombs have passed through this gun and it is still working fine. The second project, the S-Band MPG, is now operational. It is functioning at a frequency of 2.85 GHz, a repetition rate of 30 Hz, with a 2 μs-long macro-pulse. It produces about 45 A in the macro-pulse. The third project is a 34.2 GHz frequency-multiplied source driven by an X-Band MPG. A point design was performed at an rf output power of 150 MW at 34.2 GHz. The resulting system efficiency is 53% and the gain is 60 dB. The system efficiency includes the input cavity efficiency, input driver efficiency (a 50 MW klystron at 11.4 GHz), output cavity efficiency, and the post-acceleration efficiency.

  15. 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.

    2008-12-01

    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.

  16. God and Guns: Examining Religious Influences on Gun Control Attitudes in the United States

    Directory of Open Access Journals (Sweden)

    Stephen M. Merino

    2018-06-01

    Full Text Available Mass shootings in the United States have generated significant media coverage and public concern, invigorating debates over gun control. Media coverage and academic research on gun control attitudes and reactions to mass shootings have paid little attention to the role of religion. Recent research sheds light on the complex relationship between religion and guns, including higher rates of gun ownership and stronger opposition to gun control among white evangelical Protestants. Using nationally representative survey data, this study examines the relationship between religious identity, gun ownership, and support for a range of gun control policies, including proposed remedies for preventing mass shootings. Compared with individuals from other religious traditions, evangelical Protestants are most opposed to stricter gun control laws and enforcement, even with statistical controls for gun ownership and demographic characteristics. Rather, they favor individualistic solutions and putting more emphasis on religious values in their social surroundings. I discuss how these findings reflect the cultural tools evangelical Protestants use to construct their understandings of social problems, including gun violence, and the broader implications for gun policy in the United States.

  17. Analysis of hepatic gene expression during fatty liver change due to chronic ethanol administration in mice

    International Nuclear Information System (INIS)

    Yin, H.-Q.; Je, Young-Tae; Kim, Mingoo; Kim, Ju-Han; Kong, Gu; Kang, Kyung-Sun; Kim, Hyung-Lae; Yoon, Byung-IL; Lee, Mi-Ock; Lee, Byung-Hoon

    2009-01-01

    Chronic consumption of ethanol can cause cumulative liver damage that can ultimately lead to cirrhosis. To explore the mechanisms of alcoholic steatosis, we investigated the global intrahepatic gene expression profiles of livers from mice administered alcohol. Ethanol was administered by feeding the standard Lieber-DeCarli diet, of which 36% (high dose) and 3.6% (low dose) of the total calories were supplied from ethanol for 1, 2, or 4 weeks. Histopathological evaluation of the liver samples revealed fatty changes and punctate necrosis in the high-dose group and ballooning degeneration in the low-dose group. In total, 292 genes were identified as ethanol responsive, and several of these differed significantly in expression compared to those of control mice (two-way ANOVA; p < 0.05). Specifically, the expression levels of genes involved in hepatic lipid transport and metabolism were examined. An overall net increase in gene expression was observed for genes involved in (i) glucose transport and glycolysis, (ii) fatty acid influx and de novo synthesis, (iii) fatty acid esterification to triglycerides, and (iv) cholesterol transport, de novo cholesterol synthesis, and bile acid synthesis. Collectively, these data provide useful information concerning the global gene expression changes that occur due to alcohol intake and provide important insights into the comprehensive mechanisms of chronic alcoholic steatosis

  18. The Effects of Cueing and Framing on Youth Attitudes towards Gun Control and Gun Rights

    Directory of Open Access Journals (Sweden)

    Stephen Wu

    2018-02-01

    Full Text Available I analyze attitudes towards gun control from a recent survey of American high school students. For students who most closely identify as Republicans, cueing them to think about prior school shootings increases their agreement that armed staff in schools will improve safety and arming citizens will reduce risk of mass shootings. For those identifying as Democrats and Independents, providing them with selective information that certain states have loose gun control laws and low rates of gun violence makes them more supportive of gun rights. For Republicans, providing selective information that certain states have loose gun control laws and high rates of gun violence makes them less supportive of gun rights. These results suggest that emotional cues may exacerbate a priori biases, while informational cues may be more likely to change people’s minds about firearm policies.

  19. Plasma-gun fueling for tokamak reactors

    International Nuclear Information System (INIS)

    Ehst, D.A.

    1980-11-01

    In light of the uncertain extrapolation of gas puffing for reactor fueling and certain limitations to pellet injection, the snowplow plasma gun has been studied as a fueling device. Based on current understanding of gun and plasma behavior a design is proposed, and its performance is predicted in a tokamak reactor environment

  20. Where have all the gun deaths gone?

    African Journals Online (AJOL)

    Gun violence denialists recently dismissed the findings of two studies presented at a seminar co-hosted by Gun Free South Africa, the. Institute for Security Studies and the African. Policing Civilian Oversight Forum. Abrahams et al.[1] compared the profile of female homicides from two representative national samples.

  1. Gun Control: The Debate and Public Policy.

    Science.gov (United States)

    Watkins, Christine

    1997-01-01

    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)

  2. Cerebral damage caused by nail gun injury

    DEFF Research Database (Denmark)

    Andersen, Chris

    2016-01-01

    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....... 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...... criminal act. They found bloodstains on the back of the machine. When awake, the man explained, that by accident, he had hit his head against a nail gun and as a result of this, the nail gun delivered a nail into his skull. Conclusion Sometimes, the circumstances of a case are not clear...

  3. New Electron Gun System for BEPCII

    CERN Document Server

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

    2005-01-01

    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.

  4. The Ames Vertical Gun Range

    Science.gov (United States)

    Karcz, J. S.; Bowling, D.; Cornelison, C.; Parrish, A.; Perez, A.; Raiche, G.; Wiens, J.-P.

    2016-01-01

    The Ames Vertical Gun Range (AVGR) is a national facility for conducting laboratory- scale investigations of high-speed impact processes. It provides a set of light-gas, powder, and compressed gas guns capable of accelerating projectiles to speeds up to 7 km s(exp -1). The AVGR has a unique capability to vary the angle between the projectile-launch and gravity vectors between 0 and 90 deg. The target resides in a large chamber (diameter approximately 2.5 m) that can be held at vacuum or filled with an experiment-specific atmosphere. The chamber provides a number of viewing ports and feed-throughs for data, power, and fluids. Impacts are observed via high-speed digital cameras along with investigation-specific instrumentation, such as spectrometers. Use of the range is available via grant proposals through any Planetary Science Research Program element of the NASA Research Opportunities in Space and Earth Sciences (ROSES) calls. Exploratory experiments (one to two days) are additionally possible in order to develop a new proposal.

  5. Interpreting the empirical evidence on illegal gun market dynamics.

    Science.gov (United States)

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

    2012-10-01

    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.

  6. Gun Violence, Mental Illness, And Laws That Prohibit Gun Possession: Evidence From Two Florida Counties.

    Science.gov (United States)

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

    2016-06-01

    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. Project HOPE—The People-to-People Health Foundation, Inc.

  7. Gun Violence Following Inpatient Psychiatric Treatment: Offense Characteristics, Sources of Guns, and Number of Victims.

    Science.gov (United States)

    Kivisto, Aaron J

    2017-10-01

    This study presents data on the relative contribution to gun violence by people with a history of inpatient psychiatric treatment and on federal efforts to deter presumptively dangerous persons from obtaining firearms, information useful for analyzing the potential public health benefits of gun policies targeting people with serious mental illness. The study also estimates the reduction in gun violence victims that would be expected if individuals with a previous psychiatric hospitalization were prohibited from purchasing firearms. Data from 838 violent gun offenders from a nationally representative sample of state prison inmates were analyzed. Those with and without a history of psychiatric hospitalization were compared on a range of offense characteristics, including relationship to the victim, number of victims, location of the offense, and source of firearms. Inmates with a history of hospitalization constituted 12% of all violent gun offenders and accounted for 13% of the sample's victims. They were less likely than those without a previous hospitalization to victimize strangers (odds ratio=.52) and were no more likely to commit gun violence in public or to have multiple victims. Among those with previous hospitalizations, 78% obtained guns from sources not subject to federal background checks. Of the total 1,041 victims of gun violence, only 3% were victimized by participants with a history of hospitalization who obtained guns from currently regulated sources. Prohibiting all individuals with a history of psychiatric hospitalization from purchasing firearms, absent expanded background checks, was estimated to reduce the number of gun violence victims by only 3%.

  8. Oregon's Gun Relief Program for Adjudicated Mentally Ill Persons: The Psychiatric Security Review Board.

    Science.gov (United States)

    Britton, Juliet; Bloom, Joseph D

    2015-06-01

    This article describes the State of Oregon's implementation of two programs designed to comply with federal gun laws regarding reporting individuals who have received mental health adjudications in criminal and civil courts. One mandate requires that states submit names of adjudicated individuals to the National Instant Criminal Background Check System (NICS) while the second requires that the state establish a qualifying gun restoration program for those disqualified from gun ownership. In 2009, Oregon's Legislature developed an administrative approach to gun restoration and assigned the responsibility for conducting these hearing to the Oregon Psychiatric Security Review Board (PSRB). The PSRB is a state administrative board that has existed since 1977 and has been primarily focused on the supervision and treatment of adult and juvenile insanity acquittees. The gun restoration program began in 2010, but to date has only received three completed petitions requesting restoration of firearm rights. The article concludes with a discussion that surmises why very few of the Oregonians who are listed in NICS have submitted petitions for relief. Copyright © 2015 John Wiley & Sons, Ltd.

  9. One nanosecond pulsed electron gun systems

    International Nuclear Information System (INIS)

    Koontz, R.F.

    1979-02-01

    At SLAC there has been a continuous need for the injection of very short bunches of electrons into the accelerator. Several time-of-flight experiments have used bursts of short pulses during a normal 1.6 micro-second rf acceleration period. Single bunch beam loading experiments made use of a short pulse injection system which included high power transverse beam chopping equipment. Until the equipment described in this paper came on line, the basic grid-controlled gun pulse was limited to a rise time of 7 nanoseconds and a pulse width of 10 nanoseconds. The system described here has a grid-controlled rise time of less than 500 pico-seconds, and a minimum pulse width of less than 1 nanosecond. Pulse burst repetition rate has been demonstrated above 20 MHz during a 1.6 microsecond rf accelerating period. The order-of-magnitude increase in gun grid switching speed comes from a new gun design which minimizes lead inductance and stray capacitance, and also increases gun grid transconductance. These gun improvements coupled with a newly designed fast pulser mounted directly within the gun envelope make possible subnanosecond pulsing of the gun

  10. Gun Violence, mental health, and Connecticut physicians.

    Science.gov (United States)

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

    2014-01-01

    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.

  11. Design of the BEPCII electron gun system

    International Nuclear Information System (INIS)

    Liu Bo; Gu Mengping; Chi Yunlong

    2006-01-01

    BEPCII upgrading project needs a new high current electron gun. The design stage such as physical design, mechanical design and control system design of this new electron gun is described. The emission current is designed to be higher than 10 A for the pulse width of 1 ns with repetition rate of 50 Hz. The gun will operate with a pulsed high voltage power supply which can provide up to 200 kV high voltage. Computer simulations and optimizations have been carried out in the design stage, including the gun geometry and beam transport. EGUN and DGUN codes are used to simulate the gun geometry, and the results show that the perveance is about 0.22 μA·V -3/2 , and the emittance at gun exit is about 16 π·mm·mrad. PARMELA code shows that the electron beam can be easily transported to the end of the first accelerating tube with a capture efficiency of 67% and root mean square emittance of 25 mm·mrad. New scheme of the gun control system based on EPICS is also presented. Two-bunch operation mode and 2.5 μs long pulse operation mode are available in the control system. (authors)

  12. Simple light gas guns for hypervelocity studies

    International Nuclear Information System (INIS)

    Combs, S.K.; Haselton, H.H.; Milora, S.L.

    1990-01-01

    Two-stage light guns are used extensively in hypervelocity research. The applications of this technology include impact studies and special materials development. Oak Ridge National Laboratory (ORNL) has developed two-stage guns that accelerate small projectiles (4-mm nominal diameter) to velocities of up to ∼5 km/s. These guns are relatively small and simple (thus, easy to operate), allowing a significant number of test shots to be carried out and data accumulated in a short time. Materials that have been used for projectiles include plastics, frozen isotopes of hydrogen, and lithium hydride. One gun has been used to demonstrate repetitive operation at a rate of 0.7 Hz; and, with a few design improvements, it appears capable of performing at firing frequencies of 1--2 Hz. A schematic of ORNL two-stage device is shown below. Unlike most such devices, no rupture disks are used. Instead, a fast valve (high-flow type) initiates the acceleration process in the first stage. Projectiles can be loaded into the gun breech via the slide mechanism; this action has been automated which allows repetitive firing. Alternatively, the device is equipped with ''pipe gun'' apparatus in which gas can be frozen in situ in the gun barrel to form the projectile. This equipment operates with high reliability and is well suited for small-scale testing at high velocity. 17 refs., 6 figs., 2 tabs

  13. Extended suicide using an atypical stud gun.

    Science.gov (United States)

    Hagemeier, L; Schyma, C; Madea, B

    2009-08-10

    Suicides with stud guns are uncommon, but are well documented in the literature. On rare occasions, stud guns are also used as a homicide weapon. This case report describes an extended suicide in which a husband killed his wife and their two dogs, which lived on the property. The husband then committed suicide with a shot from the stud gun into his skull. He was a 70-year-old pensioner, a retired butcher, who was found by his son. He was lying in a supine position on a carpet in the living room, with the stud gun stuck in his skull. During autopsy, high concentrations of an antihistamine were found in the blood of each corpse; this drug is used as a soporific. In contrast to the literature, which mainly describes powder deposits due to the use of conventional stud guns, in this case a stud gun was used in which the expanding gases and powder escaped together with the central bolt at the front of the device; powder drains were not involved. Detailed findings of the autopsy are given with reference to this type of stud gun.

  14. Influence of routes and administration parameters on antibody response of pigs following DNA vaccination

    DEFF Research Database (Denmark)

    Barfoed, Annette Malene; Kirstensen, Birte; Dannemann-Jensen, Tove

    2004-01-01

    Using the nucleoprotein of porcine reproductive and respiratory syndrome virus as model antigen, we optimised parameters for gene gun vaccination of pigs, including firing pressure and vaccination site. As criteria for optimisation, we characterised particle penetration and local tissue damage...... by histology. For selected combinations, vaccination efficiency in terms of antibody response was studied. Gene gun vaccination on ear alone was as efficient as a multi-site (ear, thorax, inguinal area, tongue mucosa) gene gun approach, and more efficient than combined intramuscular (i.m.)/intradermal (i.......d.) injection of plasmid DNA. This indicates, that the ear is an attractive site for gene gun vaccination of pigs....

  15. Alignment Fixtures For Vacuum-Plasma-Spray Gun

    Science.gov (United States)

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

    1993-01-01

    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.

  16. Gun Safety Management with Patients at Risk for Suicide

    Science.gov (United States)

    Simon, Robert I.

    2007-01-01

    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…

  17. Ready, Fire, Aim: The College Campus Gun Fight

    Science.gov (United States)

    Birnbaum, Robert

    2013-01-01

    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…

  18. DC photoemission electron guns as ERL sources

    International Nuclear Information System (INIS)

    Sinclair, Charles K.

    2006-01-01

    Very-high-voltage DC electron guns, delivering moderate duration bunches from photoemission cathodes, and followed by conventional drift bunching and acceleration, offer a practical solution for an ERL injector. In a variant of this scheme, a DC gun is placed in close proximity to a superconducting RF accelerator cavity, with few or no active elements between the gun and cavity. The principal technical challenge with such electron guns arises from field emission from the cathode electrode and its support structure. Field emission may result in voltage breakdown across the cathode-anode gap, or a punch-through failure of the insulator holding off the cathode potential, as well as lesser though still serious problems. Various means to mitigate these problems are described. The operational lifetime of high quantum efficiency photocathodes in these guns is determined by the vacuum conditions, through phenomena such as chemical poisoning and ion back-bombardment. Minimization of the field strength on electrode structures pushes high-voltage DC guns toward large dimensions and, correspondingly, large outgassing loads, but it is also true that these guns offer many opportunities for achieving excellent vacuum conditions. Good solutions to vacuum problems that had previously limited cathode lifetime have been demonstrated in recent years. Designs for DC guns presently in use and planned for the near future will be described. The parameters necessary for a 100 mA average current, very-high-voltage DC gun with a photocathode operational lifetime greater than 100 h appear to be within reach, but have yet to be demonstrated. A 1 A average current source with good cathode operational lifetime will require developments beyond the present state-of-the-art

  19. Design and development of a pierce electron gun

    International Nuclear Information System (INIS)

    Bhattacharjee, D.; Tiwari, R.; Nayak, B.; Tillu, A.R.; Jayaprakash, D.; Mishra, R.L.; Mittal, K.C.; Chakravarthy, D.P.; Gantayet, L.M.

    2011-01-01

    An electron gun is designed and developed using the Pierce configuration for the focusing electrode. Simulations were carried out using CST Particle Studio. The Gun is a thermionic type electron gun with indirect heating of the LaB6 cathode. The gun is capable of delivering a beam current of 500 mA at 50 kV with a beam size of less than 3.5 mm. It was tested on the gun test bench. This paper presents the gun design, particle simulations study, testing of the gun on test bench and integration with the ECIL 9 MeV linac. (author)

  20. Evaluation of Smart Gun Technologies preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D.R.

    1996-01-01

    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.

  1. Field reversal produced by a plasma gun

    International Nuclear Information System (INIS)

    Hartman, C.W.; Condit, W.; Granneman, E.H.A.; Prono, D.; Smith, A.C. Jr.; Taska, J.; Turner, W.C.

    1980-01-01

    Experimental results are presented of the production of Field-Reversed Plasma with a high energy coaxial plasma gun. The gun is magnetized with solenoids inside the center electrode and outside the outer electrode so that plasma emerging from the gun entrains the radial fringer field at the muzzle. The plasma flow extends field lines propagating a high electrical conductivity, the flux inside the center electrode should be preserved. However, for low flux, the trapped flux exceeds by 2 or more the initial flux, possibly because of helical deformation of the current channel extending from the center electrode

  2. Performance of the Brookhaven photocathode rf gun

    International Nuclear Information System (INIS)

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, J.; Fisher, A.S.; Gallardo, J.; Ingold, G.; Kirk, H.G.; Leung, K.P.; Malone, R.; Pogorelsky, I.; Srinivasan-Rao, T.; Rogers, J.; Tsang, T.; Sheehan, J.; Ulc, S.; Woodle, M.; Xie, J.; Zhang, R.S.; Lin, L.Y.; McDonald, K.T.; Russell, D.P.; Hung, C.M.; Wang, X.J.

    1991-01-01

    The Brookhaven Accelerator Test Facility (ATF) uses a photocathode rf gun to provide a high-brightness electron beam intended for FEL and laser-acceleration experiments. The rf gun consists of 1 1/2 cells driven at 2856 MHz in π-mode with a maximum cathode field of 100 MV/m. To achieve long lifetimes, the photocathode development concentrates on robust metals such as copper, yttrium and samarium. We illuminate these cathodes with a 10-ps, frequency-quadrupled Nd:YAG laser. We describe the initial operation of the gun, including measurements of transverse and longitudinal emittance, quantum efficiencies, and peak current. The results are compared to models

  3. Beam emittance measurement from CERN thermionic guns

    International Nuclear Information System (INIS)

    Kester, O.; Rao, R.; Rinolfi, L.

    1992-01-01

    In the LEP Injector Linacs (LIL) a thermionic gun provides electron beams with different peak intensities at an energy of 80 keV. The beam emittances were estimated from the EGUN programme. Since the gun is of triode type, the main contribution to the emittance comes from the grid. The simulation programme does not model the real geometry by assuming a cylindrical symmetry, while the grid does not have such symmetry. A Gun Test Facility (GTF), allowing emittance measurements, based on the 3-gradients-method was installed. The experimental results are presented. (author) 6 refs.; 6 figs

  4. Alpha Fuels Environmental Test Facility impact gun

    International Nuclear Information System (INIS)

    Anderson, C.G.

    1978-01-01

    The Alpha Fuels Environmental Test Facility (AFETF) impact gun is a unique tool for impact testing 238 PuO 2 -fueled heat sources of up to 178-mm dia at velocities to 300 m/s. An environmentally-sealed vacuum chamber at the muzzle of the gun allows preheating of the projectile to 1,000 0 C. Immediately prior to impact, the heat source projectile is completely sealed in a vacuum-tight catching container to prevent escape of its radioactive contents should rupture occur. The impact velocity delivered by this gas-powered gun can be regulated to within +-2%

  5. SSRL photocathode RF gun test stand

    International Nuclear Information System (INIS)

    Hernandez, M.; Baltay, M.; Boyce, A.

    1995-01-01

    A photocathode RF gun test stand designed for the production and study of high brightness electron beams will be constructed at SSRL. The beam will be generated from a laser driven third generation photocathode RF gun being 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, in order to achieve the desired low emittance beam, emittance compensation with solenoidal focusing will be employed

  6. Advances in DC photocathode electron guns

    International Nuclear Information System (INIS)

    Dunham M, Bruce; Heartmann, P.; Reza Kazimi; Hongxiu Liu; Poelker, B.M.; Price, J.S.; Rutt, P.M.; Schneider, W.J.; Sinclair K, Charles

    1998-01-01

    At Jefferson Lab, a DC photoemission gun using GaAs and GaAs-like cathodes provides a source of polarized electrons for the main accelerator. The gun is required to produce high average current with long operational lifetimes and high system throughout. Recent work has shown that careful control of the parameters affecting cathode lifetime lead to dramatic improvements in source operation. These conditions include vacuum and the related effect of ion back-bombardment, and precise control of all of the electrons emitted from the cathode. In this paper, the authors will review recent results and discuss implications for future photocathode guns

  7. Advances in DC photocathode electron guns

    International Nuclear Information System (INIS)

    Dunham, B. M.; Hartmann, P.; Kazimi, R.; Liu, H.; Poelker, B. M.; Price, J. S.; Rutt, P. M.; Schneider, W. J.; Sinclair, C. K.

    1999-01-01

    At Jefferson Lab, a DC photoemission gun using GaAs and GaAs-like cathodes provides a source of polarized electrons for the main accelerator. The gun is required to produce high average current with long operational lifetimes and high system throughput. Recent work has shown that careful control of the parameters affecting cathode lifetime lead to dramatic improvements in source operation. These conditions include vacuum and the related effect of ion backbombardment, and precise control of all of the electrons emitted from the cathode. In this paper, we will review recent results and discuss implications for future photocathode guns

  8. Advances in DC photocathode electron guns

    International Nuclear Information System (INIS)

    Dunham, B.M.; Hartmann, P.; Kazimi, R.; Liu, H.; Poelker, B.M.; Price, J.S.; Rutt, P.M.; Schneider, W.J.; Sinclair, C.K.

    1999-01-01

    At Jefferson Lab, a DC photoemission gun using GaAs and GaAs-like cathodes provides a source of polarized electrons for the main accelerator. The gun is required to produce high average current with long operational lifetimes and high system throughput. Recent work has shown that careful control of the parameters affecting cathode lifetime lead to dramatic improvements in source operation. These conditions include vacuum and the related effect of ion backbombardment, and precise control of all of the electrons emitted from the cathode. In this paper, we will review recent results and discuss implications for future photocathode guns. copyright 1999 American Institute of Physics

  9. "Is there a gun in the home?" Assessing the risks of gun ownership in older adults.

    Science.gov (United States)

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

    2014-06-01

    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. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

  10. Camouflaged Collectives: Managing Stigma and Identity at Gun Events

    Directory of Open Access Journals (Sweden)

    Sarah Jane Blithe

    2017-02-01

    Full Text Available Gun violence persists in the United States, claiming lives and escalating healthcare costs. This article seeks to contribute to social justice work on the “gun problem” by studying gun collectives. To understand gun culture and to identify gun violence reduction strategies, we study places where gun owners organize – legal (and sometimes illegal settings that facilitate dialogue about gun issues. Based on participant observation and collaborative event ethnography at gun shows and a private shooting party, this analysis presents findings about the practices gun collective members use to manage stigma. We conclude that when participants in gun events attempt to subvert core stigma through everyday stigma management practices, they effectively facilitate the unfettered exchange of potentially dangerous goods, promote the invisibility of oppressive structures, and normalize violence.

  11. 77 FR 37834 - Revocation of Certain Requirements Pertaining to Caps Intended for Use With Toy Guns and Toy Guns...

    Science.gov (United States)

    2012-06-25

    ... Certain Requirements Pertaining to Caps Intended for Use With Toy Guns and Toy Guns Not Intended for Use With Caps AGENCY: Consumer Product Safety Commission. ACTION: Notice of proposed rulemaking. SUMMARY... compliance than our existing regulations pertaining to caps intended for use with toy guns and toy guns not...

  12. Rail gun powered by an integral explosive generator

    International Nuclear Information System (INIS)

    Peterson, D.R.; Fowler, C.M.

    1979-01-01

    We propose the use of a rail gun powered by an explosive magnetic flux compression generator built into the rail gun itself in which the rails of the gun are driven together behind the projectile by explosives. The magnetic field established between the rails by an initial current supplied by an external source at the breech of the gun is trapped and compressed by the collapsing rails to accelerate the projectile down the bore of the gun

  13. Chronic Binge Alcohol Administration Dysregulates Hippocampal Genes Involved in Immunity and Neurogenesis in Simian Immunodeficiency Virus-Infected Macaques

    Directory of Open Access Journals (Sweden)

    John K. Maxi

    2016-11-01

    Full Text Available Alcohol use disorders (AUD exacerbate neurocognitive dysfunction in Human Immunodeficiency Virus (HIV+ patients. We have shown that chronic binge alcohol (CBA administration (13–14 g EtOH/kg/wk prior to and during simian immunodeficiency virus (SIV infection in rhesus macaques unmasks learning deficits in operant learning and memory tasks. The underlying mechanisms of neurocognitive alterations due to alcohol and SIV are not known. This exploratory study examined the CBA-induced differential expression of hippocampal genes in SIV-infected (CBA/SIV+; n = 2 macaques in contrast to those of sucrose administered, SIV-infected (SUC/SIV+; n = 2 macaques. Transcriptomes of hippocampal samples dissected from brains obtained at necropsy (16 months post-SIV inoculation were analyzed to determine differentially expressed genes. MetaCore from Thomson Reuters revealed enrichment of genes involved in inflammation, immune responses, and neurodevelopment. Functional relevance of these alterations was examined in vitro by exposing murine neural progenitor cells (NPCs to ethanol (EtOH and HIV trans-activator of transcription (Tat protein. EtOH impaired NPC differentiation as indicated by decreased βIII tubulin expression. These findings suggest a role for neuroinflammation and neurogenesis in CBA/SIV neuropathogenesis and warrant further investigation of their potential contribution to CBA-mediated neurobehavioral deficits.

  14. Stereotactic breast biopsy with a biopsy gun

    International Nuclear Information System (INIS)

    Parker, S.H.; Lovin, J.; Luethke, J.; Jobe, W.E.; Hopper, K.D.; Yakes, W.F.

    1989-01-01

    With the recent introduction of stereotactic mammographic localizing devices, the authors have been performing histologic core needle breast biopsies in which the Bard biopsy gun is used in conjunction with sterotactic guidance. The authors have performed 60 breast gun biopsies with 16-gauge and 18-gauge biopsy-cut needles. These biopsies were followed immediately by traditional surgical excision. Pathologic results correlated well in 52 of the 60 patients, including 10 of 13 cancers. Three of the eight negative correlations occurred when diagnosis was made on gun biopsy but not on surgical biopsy. The stereotactic- guided gun biopsies appear to approach the surgical gold standard, decrease patient discomfort and potential disfigurement, lower the cost of breast biopsy, and lower the threshold necessary to perform breast biopsy

  15. RF Electron Gun with Driven Plasma Cathode

    CERN Document Server

    Khodak, Igor

    2005-01-01

    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. Electro Thermal Chemical Gun Technology Study

    National Research Council Canada - National Science Library

    Diamond, P

    1999-01-01

    .... Michael Stroscio. Electro Thermal Chemical (ETC) gun technology refers to the use of plasma devices in place of traditional chemical ignitors to initiate the burning of high energy propellants in a controlled manner...

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

    Index Scriptorium Estoniae

    2006-01-01

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

  18. Prestressed Carbon Fiber Composite Overwrapped Gun Tube

    National Research Council Canada - National Science Library

    Littlefield, Andrew; Hyland, Edward

    2006-01-01

    .... Using composite materials not only directly removes weight from the gun tube but, by better balancing the tube, allows the use of smaller drive systems, thus further enhancing the system weight loss...

  19. Ballistic Rail Gun Soft Recovery Facility

    Data.gov (United States)

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

  20. Arc Plasma Gun With Coaxial Powder Feed

    Science.gov (United States)

    Zaplatynsky, Isidor

    1988-01-01

    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.

  1. Mass Shootings, Mental Illness, and Gun Control.

    Science.gov (United States)

    Philpott-Jones, Sean

    2018-03-01

    In the wake of the Stoneman Douglas School shooting, Republican and Democratic leaders-like the American electorate they represent-remain sharply divided in their responses to gun violence. They are united in their condemnation of these mass shootings, but they disagree about whether stricter or looser gun control laws are the answer. Those on the right side of the political aisle suggest that the issue is one of mental illness rather than gun control. Conversely, those who are more liberal or progressive in their political learnings are quick to condemn attempts to reframe the issue of mass shootings as a mental health problem. Both sides are wrong. Mass shootings are indeed partially a mental health problem, albeit one poorly addressed by our current laws and policies. But the solution to mass shootings also needs to consider strategies that may reduce gun violence in general. © 2018 The Hastings Center.

  2. Gun Trafficking and the Southwest Border

    Science.gov (United States)

    2009-07-29

    felons, drug traffickers, and juvenile gang members from acquiring firearms from gun traffickers. These criminals often acquire firearms from persons...renounced their U.S. citizenship; (8) persons restrained under a court-order from harassing, stalking , or threatening an intimate partner or child of... gang members from acquiring firearms from gun traffickers. These criminals often acquire firearms from a person who otherwise is not prohibited to

  3. Conference on electromagnetic guns and launchers, 1980

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Proceedings includes 31 papers dealing with the physical principles and engineering technology associated with the development of electromagnetic propulsion, with emphasis on its use for guns, launchers as well as other military equipment. Topics covered include: rail guns, projectiles, mass accelerators, electric motors and generators, nuclear reactors, superconducting devices, plasma acceleration and confinement, traveling magnetic waves, aerospace propulsion, space shuttles, homopolar generators, fusion reactors, tokamaks, impact fusion, and electric power generation. All papers are abstracted and indexed separately

  4. Modifications Of A Commercial Spray Gun

    Science.gov (United States)

    Allen, Peter B.

    1993-01-01

    Commercial spray gun modified to increase spray rate and make sprayed coats more nearly uniform. Consists of gun head and pneumatic actuator. Actuator opens valves for two chemical components, called "A" and "B," that react to produce foam. Components flow through orifices, into mixing chamber in head. Mixture then flows through control orifice to spray tip. New spray tip tapered to reduce area available for accumulation of foam and makes tip easier to clean.

  5. On the frequency scalings of RF guns

    International Nuclear Information System (INIS)

    Lin, L.C.; Chen, S.C.; Wurtele, J.S.

    1995-01-01

    A frequency scaling law for RF guns is derived from the normalized Vlasov-Maxwell equations. It shows that higher frequency RF guns can generate higher brightness beams under the assumption that the accelerating gradient and all beam and structure parameters are scaled with the RF frequency. Numerical simulation results using MAGIC confirm the scaling law. A discussion of the range of applicability of the law is presented. copyright 1995 American Institute of Physics

  6. The Impact of Banning Juvenile Gun Possession.

    OpenAIRE

    Marvell, Thomas B

    2001-01-01

    A 1994 federal law bans possession of handguns by persons under 18 years of age. Also in 1994, 11 states passed their own juvenile gun possession bans. Eighteen states had previously passed bans, 15 of them between 1975 and 1993. These laws were intended to reduce homicides, but arguments can be made that they have no effect on or that they even increase the homicide rate. This paper estimates the laws' impacts on various crime measures, primarily juvenile gun homicide victimizations and suic...

  7. Intraperitoneal administration of the globular adiponectin gene ameliorates diabetic nephropathy in Wistar rats.

    Science.gov (United States)

    Yuan, Fang; Liu, Ying-Hong; Liu, Fu-You; Peng, You-Ming; Tian, Jun-Wei

    2014-06-01

    The present study investigated the potential effects of the long-term expression of exogenous adiponectin (ADPN) on normal and diabetic kidneys. Type 2 diabetes mellitus models were induced by high-lipid and high-sucrose feeding plus intraperitoneal injection of streptozotocin. The recombinant plasmid pIRES2-EGFP-gAd, which is able to co-express globular ADPN (gAd) and enhanced green fluorescent protein (EGFP), was intraperitoneally injected into rat models mediated by Lipofectamine. In total, 32 Wistar rats were randomly assigned into four groups: the normal control group, the diabetes group, the diabetes group treated with pIRES2-EGFP-gAd and the diabetes group treated with pIRES2-EGFP. After 12 weeks, serum biochemistry and urine albumin levels were measured. The kidneys were collected to assess the generation of reactive oxygen species (ROS) and the renal pathological changes were observed by light microcopy. The protein expression of endothelial nitric oxide synthase (eNOS), transforming growth factor-β1 (TGF-β1) and phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK) were determined by an immunohistochemical staining method and western blot analysis. Intraperitoneal injection of the human gAd gene via Lipofectamine resulted in abundant ADPN protein in the kidney. In the diabetic rats, the delivery of the exogenous gAd gene ameliorated the progression of diabetic nephropathy (DN). ADPN attenuated urine albumin excretion in the diabetic rats. ADPN also mitigated glomerular mesangial expansion, reduced the generation of ROS and prevented interstitial fibrosis. In addition, the expression of gAd inhibited the renal expression of TGF-β1, promoted the protein expression of eNOS and activated the opening of the AMPK signaling pathway in the renal tissues of the diabetic rats. Despite the effects of ADPN on DN being controversial, these observations indicate that the supplementation of ADPN is beneficial in ameliorating DN in rats.

  8. Electrothermal plasma gun as a pellet injector

    International Nuclear Information System (INIS)

    Kincaid, R.W.; Bourham, M.A.

    1994-01-01

    The NCSU electrothermal plasma gun SIRENS has been used to accelerate plastic (Lexan polycarbonate) pellets, to determine the feasibility of the use of electrothermal guns as pellet injectors. The use of an electrothermal gun to inject frozen hydrogenic pellets requires a mechanism to provide protective shells (sabots) for shielding the pellet from ablation during acceleration into and through the barrel of the gun. The gun has been modified to accommodate acceleration of the plastic pellets using special acceleration barrels equipped with diagnostics for velocity and position of the pellet, and targets to absorb the pellet's energy on impact. The length of the acceleration path could be varied between 15 and 45 cm. The discharge energy of the electrothermal gun ranged from 2 to 6 kJ. The pellet velocities have been measured via a set of break wires. Pellet masses were varied between 0.5 and 1.0 grams. Preliminary results on 0.5 and 1.0 g pellets show that the exit velocity reaches 0.9 km/s at 6 kJ input energy to the source. Higher velocities of 1.5 and 2.7 km/s have been achieved using 0.5 and 1.0 gm pellets in 30 cm long barrel, without cleaning the barrel between the shots

  9. Electron gun for the Fel Clio

    International Nuclear Information System (INIS)

    Chaput, R.

    1990-01-01

    A triode electron gun has been developed and manufactured at LURE (Laboratoire pour l'Utilisation du Rayonnement Electromagnetique) and LAL (Laboratoire de l'Accelerateur Lineaire) for the free electron laser CLIO 1 (Collaboration pour un laser a electrons libres dans l'infrarouge a Orsay) now under construction: this gun involves a grid-cathode assembly manufactured by EIMAC, currently used in the SLAC gun family. For the FEL requirements, the gun must be able to yield a train of short pulses at accuracy frequency or a continuous pulse. Driving together the cathode and the grid the gun produces a continous beam of 12 μs or a pulsed beam of very short pulse of 1 ns at 250 MHz, 125 MHz, 62.5 MHz or 31.25 MHz. The performances of the gun has been tested on a testing bench. A peak current of 1 Amp. for 1 ns width at any frequencies was achieved at an injection voltage of 90 kV

  10. Are "goods for guns" good for the community? An update of a community gun buyback program.

    Science.gov (United States)

    Green, Jonathan; Damle, Rachelle N; Kasper, Rebecca E; Violano, Pina; Manno, Mariann; Nazarey, Pradeep P; Aidlen, Jeremy T; Hirsh, Michael P

    2017-08-01

    Gun violence remains a leading cause of death in the United States. Community gun buyback programs provide an opportunity to dispose of extraneous firearms. The purpose of this study was to understand the demographics, motivation, child access to firearms, and household mental illness of buyback participants in hopes of improving the program's effectiveness. A 2015 Injury Free Coalition for Kids gun buyback program which collaborated with local police departments was studied. We administered a 23-item questionnaire survey to gun buyback participants assessing demographic characteristics, motivation for relinquishing firearms, child firearm accessibility, and mental illness/domestic violence history. A total of 186 individuals from Central/Western Massachusetts turned in 339 weapons. Participants received between US $25 and US $75 in gift cards dependent on what type of gun was turned in, with an average cost of $41/gun. A total of 109 (59%) participants completed the survey. Respondents were mostly white (99%), men (90%) and first-time participants in the program (85.2%). Among survey respondents, 54% turned in firearms "for safety reasons." Respondents reported no longer needing/wanting their weapons (47%) and approximately one in eight participants were concerned the firearm(s) were accessible to children. Most respondents (87%) felt the program encouraged neighborhood awareness of firearm safety. Three of every five participants reported that guns still remained in their homes; additionally, 21% where children could potentially access them and 14% with a history of mental illness/suicide/domestic violence in the home. Gun buybacks can provide a low-cost means of removing unwanted firearms from the community. Most participants felt their homes were safer after turning in the firearm(s). In homes still possessing guns, emphasis on secure gun storage should continue, increasing the safety of children and families. The results of this survey also provided new

  11. Nail gun injuries among construction workers.

    Science.gov (United States)

    Dement, John M; Lipscomb, Hester; Li, Leiming; Epling, Carol; Desai, Tejas

    2003-05-01

    Pneumatic nail guns greatly increase worker productivity and are extensively used in wood frame building construction, with especially high use in residential construction. One surveillance report of nail gun injuries in Washington State has been published; however, other literature consists largely of case reports and case series in trauma journals. The major objective of the current study was to investigate the occurrence of nail gun-associated injuries among construction workers and to identify preventable work-related factors associated with these injuries. Nail gun-related injuries occurring among a cohort of 13,347 carpenters in Ohio who worked union hours during the time period January 1, 1994, until September 30, 1997, were identified by matching the cohort with workers' compensation claims made to the Ohio Bureau of Workers' Compensation. We also analyzed workers' compensation claims for North Carolina Home Builders Association members for the period July 1996-November 1999 to identify nail gun-related injuries. Analyses included stratified analyses of claims by nature and body part injured, calculation of nail gun injury rates, and analyses of free text descriptions of injuries. Overall, nail gun injuries were responsible for 3.9 percent of workers' compensation claims with 8.3 percent to 25.5 percent of claims involving paid lost work time. The overall rate of nail gun injuries (cases per 200,000 work hours) was 0.33 in North Carolina and 0.26 in Ohio, reflecting the greater concentration of wood frame construction workers in the North Carolina population studied. Higher rates of injury were observed for carpenters in North Carolina and among residential carpenters in Ohio. The predominant body part injured was the hands/fingers, with 80 to 89 percent of injuries being nail punctures. Analyses of free text information for puncture injuries found approximately 70 percent of injuries to occur during the framing/sheathing stage of construction. Our data

  12. Improved DC Gun Insulator Assembly

    International Nuclear Information System (INIS)

    Neubauer, M.L.; Dudas, A.; Sah, R.; Poelker, M.; Surles-Law, K.E.L.

    2010-01-01

    Many user facilities such as synchrotron radiation 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 often exhibit poor reliability. Two technical approaches to solving this problem will be investigated. Firstly, inverted ceramics offer solutions for reduced gradients between the electrodes and ground. An inverted design will be presented for 350 kV, with maximum gradients in the range of 5-10 MV/m. Secondly, novel ceramic manufacturing processes will be studied, in order to protect triple junction locations from emission, by applying a coating with a bulk resistivity. The processes for creating this coating will be optimized to provide protection as well as be used to coat a ceramic with an appropriate gradient in bulk resistivity from the vacuum side to the air side of an HV standoff ceramic cylinder. Example insulator designs are being computer modelled, and insulator samples are being manufactured and tested

  13. Gun Carrying by High School Students in Boston, MA: Does Overestimation of Peer Gun Carrying Matter?

    Science.gov (United States)

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

    2011-01-01

    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…

  14. Relationship between licensing, registration, and other gun sales laws and the source state of crime guns.

    Science.gov (United States)

    Webster, D W; Vernick, J S; Hepburn, L M

    2001-09-01

    To determine the association between licensing and registration of firearm sales and an indicator of gun availability to criminals. Tracing data on all crime guns recovered in 25 cities in the United States were used to estimate the relationship between state gun law categories and the proportion of crime guns first sold by in-state gun dealers. In cities located in states with both mandatory registration and licensing systems (five cities), a mean of 33.7% of crime guns were first sold by in-state gun dealers, compared with 72.7% in cities that had either registration or licensing but not both (seven cities), and 84.2% in cities without registration or licensing (13 cites). Little of the difference between cities with both licensing and registration and cities with neither licensing nor registration was explained by potential confounders. The share of the population near a city that resides in a neighboring state without licensing or registration laws was negatively associated with the outcome. States with registration and licensing systems appear to do a better job than other states of keeping guns initially sold within the state from being recovered in crimes. Proximity to states without these laws, however, may limit their impact.

  15. Separating Batterers and Guns: A Review and Analysis of Gun Removal Laws in 50 States

    Science.gov (United States)

    Frattaroli, Shannon; Vernick, Jon S.

    2006-01-01

    Firearms play an important role in lethal domestic violence incidents. The authors review state laws regarding two policies to separate batterers from firearms: laws authorizing police to remove firearms when responding to a domestic violence complaint ("police gun removal laws") and laws authorizing courts to order guns removed from batterers…

  16. A high-brightness thermionic microwave electron gun

    Energy Technology Data Exchange (ETDEWEB)

    Borland, Michael [Stanford Univ., CA (United States)

    1991-02-01

    In a collaborative effort by SSRL, AET Associates, and Varian Associates, a high-brightness microwave electron gun using a thermionic cathode has been designed, built, tested, and installed for use with the SSRL 150 MeV linear accelerator. This thesis discusses the physics behind the design and operation of the gun and associated systems, presenting predictions and experimental tests of the gun`s performance. The microwave gun concept is of increasing interest due to its promise of providing higher-current, lower-emittance electron beams than possible from conventional, DC gun technology. In a DC guns, accelerating gradients are less than 8 MV/m, while those in a microwave gun can exceed 100 MV/m, providing much more rapid initial acceleration, thereby reducing the deleterious effects of space-charge. Microwave guns produce higher momentum beams than DC guns, thus lessening space-charge effects during subsequent beam transport. Typical DC guns produce kinetic energies of 80--400 KeV, compared to 2--3 MeV for the SSRL microwave gun. ``State-of-the-art`` microwave gun designs employ laser-driven photocathodes, providing excellent performance but with greater complexity and monetary costs. A thermionic microwave gun with a magnetic bunching system is comparable in cost and complexity to a conventional system, but provides performance that is orders of magnitude better. Simulations of the SSRL microwave gun predict a normalized RMS emittance at the gun exist of < 10 π • mec • μm for a beam consisting of approximately 50% of the particles emitted from the gun, and having a momentum spread ±10%. These emittances are for up to 5 x 109e- per bunch. Chromatic aberrations in the transport line between the gun and linear accelerator increase this to typically < 30 π • me • μm.

  17. Effects of repeated potassium iodide administration on genes involved in synthesis and secretion of thyroid hormone in adult male rat.

    Science.gov (United States)

    Lebsir, Dalila; Manens, Line; Grison, Stephane; Lestaevel, Philippe; Ebrahimian, Teni; Suhard, David; Phan, Guillaume; Dublineau, Isabelle; Tack, Karine; Benderitter, Marc; Pech, Annick; Jourdain, Jean-Rene; Souidi, Maâmar

    2018-02-26

    A single dose of potassium iodide (KI) is recommended to reduce the risk of thyroid cancer during nuclear accidents. However in case of prolonged radioiodine exposure, more than one dose of KI may be necessary. This work aims to evaluate the potential toxic effect of repeated administration of KI. Adult Wistar rats received an optimal dose of KI 1 mg/kg over a period of 1, 4 or 8 days. hormonal status (TSH, FT4) of treated rats was unaffected. Contrariwise, a sequential Wolff-Chaikoff effect was observed, resulting in a prompt decrease of NIS and MCT8 mRNA expression (-58% and -26% respectively), followed by a delayed decrease of TPO mRNA expression (-33%) in conjunction with a stimulation of PDS mRNA expression (+62%). we show for the first time that repeated administration of KI at 1 mg/kg/24h doesn't cause modification of thyroid hormones level, but leads to a reversible modification of the expression of genes involved in the synthesis and secretion of thyroid hormones. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Simultaneous Administration of ADSCs-Based Therapy and Gene Therapy Using Ad-huPA Reduces Experimental Liver Fibrosis.

    Science.gov (United States)

    Meza-Ríos, Alejandra; García-Benavides, Leonel; García-Bañuelos, Jesus; Salazar-Montes, Adriana; Armendáriz-Borunda, Juan; Sandoval-Rodríguez, Ana

    2016-01-01

    hADSCs transplantation in cirrhosis models improves liver function and reduces fibrosis. In addition, Ad-huPA gene therapy diminished fibrosis and increased hepatocyte regeneration. In this study, we evaluate the combination of these therapies in an advanced liver fibrosis experimental model. hADSCs were expanded and characterized before transplantation. Ad-huPA was simultaneously administrated via the ileac vein. Animals were immunosuppressed by CsA 24 h before treatment and until sacrifice at 10 days post-treatment. huPA liver expression and hADSCs biodistribution were evaluated, as well as the percentage of fibrotic tissue, hepatic mRNA levels of Col-αI, TGF-β1, CTGF, α-SMA, PAI-I, MMP2 and serum levels of ALT, AST and albumin. hADSCs homed mainly in liver, whereas huPA expression was similar in Ad-huPA and hADSCs/Ad-huPA groups. hADSCs, Ad-huPA and hADSCs/Ad-huPA treatment improves albumin levels, reduces liver fibrosis and diminishes Collagen α1, CTGF and α-SMA mRNA liver levels. ALT and AST serum levels showed a significant decrease exclusively in the hADSCs group. These results showed that combinatorial effect of cell and gene-therapy does not improve the antifibrogenic effects of individual treatments, whereas hADSCs transplantation seems to reduce liver fibrosis in a greater proportion.

  19. Gun ownership and firearm-related deaths.

    Science.gov (United States)

    Bangalore, Sripal; Messerli, Franz H

    2013-10-01

    A variety of claims about possible associations between gun ownership rates, mental illness burden, and the risk of firearm-related deaths have been put forward. However, systematic data on this issue among various countries remain scant. Our objective was to assess whether the popular notion "guns make a nation safer" has any merits. Data on gun ownership were obtained from the Small Arms Survey, and for firearm-related deaths from a European detailed mortality database (World Health Organization), the National Center for Health Statistics, and others. Crime rate was used as an indicator of safety of the nation and was obtained from the United Nations Surveys of Crime Trends. Age-standardized disability-adjusted life-year rates due to major depressive disorder per 100,000 inhabitants with data obtained from the World Health Organization database were used as a putative indicator for mental illness burden in a given country. Among the 27 developed countries, there was a significant positive correlation between guns per capita per country and the rate of firearm-related deaths (r = 0.80; P ownership and mental illness as independent covariates, gun ownership was a significant predictor (P <.0001) of firearm-related deaths, whereas mental illness was of borderline significance (P = .05) only. The number of guns per capita per country was a strong and independent predictor of firearm-related death in a given country, whereas the predictive power of the mental illness burden was of borderline significance in a multivariable model. Regardless of exact cause and effect, however, the current study debunks the widely quoted hypothesis that guns make a nation safer. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Modeling internal ballistics of gas combustion guns.

    Science.gov (United States)

    Schorge, Volker; Grossjohann, Rico; Schönekess, Holger C; Herbst, Jörg; Bockholdt, Britta; Ekkernkamp, Axel; Frank, Matthias

    2016-05-01

    Potato guns are popular homemade guns which work on the principle of gas combustion. They are usually constructed for recreational rather than criminal purposes. Yet some serious injuries and fatalities due to these guns are reported. As information on the internal ballistics of homemade gas combustion-powered guns is scarce, it is the aim of this work to provide an experimental model of the internal ballistics of these devices and to investigate their basic physical parameters. A gas combustion gun was constructed with a steel tube as the main component. Gas/air mixtures of acetylene, hydrogen, and ethylene were used as propellants for discharging a 46-mm caliber test projectile. Gas pressure in the combustion chamber was captured with a piezoelectric pressure sensor. Projectile velocity was measured with a ballistic speed measurement system. The maximum gas pressure, the maximum rate of pressure rise, the time parameters of the pressure curve, and the velocity and path of the projectile through the barrel as a function of time were determined according to the pressure-time curve. The maximum gas pressure was measured to be between 1.4 bar (ethylene) and 4.5 bar (acetylene). The highest maximum rate of pressure rise was determined for hydrogen at (dp/dt)max = 607 bar/s. The muzzle energy was calculated to be between 67 J (ethylene) and 204 J (acetylene). To conclude, this work provides basic information on the internal ballistics of homemade gas combustion guns. The risk of injury to the operator or bystanders is high, because accidental explosions of the gun due to the high-pressure rise during combustion of the gas/air mixture may occur.

  1. A high-brightness thermionic microwave electron gun

    International Nuclear Information System (INIS)

    Borland, M.

    1991-02-01

    In a collaborative effort by SSRL, AET Associates, and Varian Associates, a high-brightness microwave electron gun using a thermionic cathode has been designed, built, tested, and installed for use with the SSRL 150 MeV linear accelerator. This thesis discusses the physics behind the design and operation of the gun and associated systems, presenting predictions and experimental tests of the gun's performance. The microwave gun concept is of increasing interest due to its promise of providing higher-current, lower-emittance electron beams than possible from conventional, DC gun technology. In a DC guns, accelerating gradients are less than 8 MV/m, while those in a microwave gun can exceed 100 MV/m, providing much more rapid initial acceleration, thereby reducing the deleterious effects of space-charge. Microwave guns produce higher momentum beams than DC guns, thus lessening space-charge effects during subsequent beam transport. Typical DC guns produce kinetic energies of 80--400 KeV, compared to 2--3 MeV for the SSRL microwave gun. ''State-of-the-art'' microwave gun designs employ laser-driven photocathodes, providing excellent performance but with greater complexity and monetary costs. A thermionic microwave gun with a magnetic bunching system is comparable in cost and complexity to a conventional system, but provides performance that is orders of magnitude better. Simulations of the SSRL microwave gun predict a normalized RMS emittance at the gun exist of e c · μm for a beam consisting of approximately 50% of the particles emitted from the gun, and having a momentum spread ±10%. These emittances are for up to 5 x 10 9 e - per bunch. Chromatic aberrations in the transport line between the gun and linear accelerator increase this to typically e · μm

  2. Development of plasma cathode electron guns

    Science.gov (United States)

    Oks, Efim M.; Schanin, Peter M.

    1999-05-01

    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.

  3. ECR ion source with electron gun

    Science.gov (United States)

    Xie, Zu Q.; Lyneis, Claude M.

    1993-01-01

    An Advanced Electron Cyclotron Resonance ion source (10) having an electron gun (52) for introducing electrons into the plasma chamber (18) of the ion source (10). The ion source (10) has a injection enclosure (12) and a plasma chamber tank (14). The plasma chamber (18) is defined by a plurality of longitudinal magnets (16). The electron gun (52) injects electrons axially into the plasma chamber (18) such that ionization within the plasma chamber (18) occurs in the presence of the additional electrons produced by the electron gun (52). The electron gun (52) has a cathode (116) for emitting electrons therefrom which is heated by current supplied from an AC power supply (96) while bias potential is provided by a bias power supply (118). A concentric inner conductor (60) and Outer conductor (62) carry heating current to a carbon chuck (104) and carbon pusher (114) Which hold the cathode (116) in place and also heat the cathode (16). In the Advanced Electron Cyclotron Resonance ion source (10), the electron gun (52) replaces the conventional first stage used in prior art electron cyclotron resonance ion generators.

  4. Tri-Service Green Gun Barrel (PP 1074)

    National Research Council Canada - National Science Library

    Rusch, Lawrence F

    2003-01-01

    ...) PP 1074 Tri-Service Green Gun Barrel. The program's goal was to develop an environmentally friendly process for depositing wear and erosion resistant materials onto gun bores replacing the current hazardous aqueous electro-deposition...

  5. To Your Health: NLM update transcript - Gun safety strategies

    Science.gov (United States)

    ... transcript040918.html To Your Health: NLM update Transcript Gun safety strategies : 04/09/2018 To use the ... on weekly topics. An evidence-based, public health gun safety strategy that is consistent with second amendment ...

  6. Simple gun for vapor deposition of organic thin films

    International Nuclear Information System (INIS)

    Sato, N.; Seki, K.; Inokuchi, H.

    1987-01-01

    A simple evaporation gun for preparing organic thin films was fabricated using commercially available parts of an electron gun for a TV Braun tube. The device permits sample heating to be easily controlled because of the small heat capacity

  7. The electromagnetic rocket gun impact fusion driver

    International Nuclear Information System (INIS)

    Winterberg, F.

    1984-01-01

    A macroparticle accelerator to be used as an impact fusion driver is discussed and which can accelerate a small projectile to --200 km/sec over a distance of a few 100 meters. The driver which we have named electromagnetic rocket gun, accelerates a small rocket-like projectile by a travelling magnetic wave. The rocket propellant not only serves as a sink to absorb the heat produced in the projectile by resistive energy losses, but at the same time is also the source of additional thrust through the heating of the propellant to high temperatures by the travelling magnetic wave. The total thrust on the projectile is the sum of the magnetic and recoil forces. In comparison to a rocket, the efficiency is here much larger, with the momentum transferred to the gun barrel of the gun rather than to a tenuous jet. (author)

  8. Secondary emission electron gun using external primaries

    Science.gov (United States)

    Srinivasan-Rao, Triveni [Shoreham, NY; Ben-Zvi, Ilan [Setauket, NY

    2009-10-13

    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.

  9. Handgun waiting periods reduce gun deaths.

    Science.gov (United States)

    Luca, Michael; Malhotra, Deepak; Poliquin, Christopher

    2017-11-14

    Handgun waiting periods are laws that impose a delay between the initiation of a purchase and final acquisition of a firearm. We show that waiting periods, which create a "cooling off" period among buyers, significantly reduce the incidence of gun violence. We estimate the impact of waiting periods on gun deaths, exploiting all changes to state-level policies in the Unites States since 1970. We find that waiting periods reduce gun homicides by roughly 17%. We provide further support for the causal impact of waiting periods on homicides by exploiting a natural experiment resulting from a federal law in 1994 that imposed a temporary waiting period on a subset of states. Copyright © 2017 the Author(s). Published by PNAS.

  10. Mechanical design of a RF electron gun

    International Nuclear Information System (INIS)

    Woodle, M.H.; Batchelor, K.; Sheehan, J.

    1989-01-01

    Brookhaven National Laboratory is building an Accelerator Test Facility at which we plan to study laser acceleration of electrons, inverse free electron lasers and the production of X-rays by non-linear Compton scattering. The facility contains an electron gun, linac, lasers and ancillary systems which will enable the production of 6 ps duration pulses of 50-100 MeV electrons. The electron source is an one and one half cell RF Electron gun which utilizes either a thermionic or photoemissive cathode to produce 5 MeV electrons. This paper discusses how gun mechanical design considerations such as material, vacuum maintenance, surface finish, fabrication methods, cavity tuning, and cathode replacement were reconciled to arrive at the final design. 9 refs., 2 figs., 2 tabs

  11. Mechanical design of a rf electron gun

    International Nuclear Information System (INIS)

    Woodle, M.H.; Batchelor, K.; Sheehan, J.

    1988-01-01

    Brookhaven National Laboratory is building an Accelerator Test Facility at which we plan to study laser acceleration of electrons inverse free electron lasers and the production of X-rays by non- linear Compton scattering. The facility contains an electron gun, linac, lasers and ancillary systems which will enable the production of 6 ps duration pulses of 50--100 MeV electrons. The electron source is an one and one half cell RF Electron gun which utilizes either a thermionic or photoemissive cathode to produce 5 MeV electrons. This paper discusses how gun mechanical design considerations such as material, vacuum maintenance, surface finish, fabrication methods, cavity tuning, and cathode replacement were reconciled to arrive at the final design. 9 refs., 2 figs., 2 tabs

  12. Photocathode operation of a thermionic RF gun

    International Nuclear Information System (INIS)

    Thorin, S.; Cutic, N.; Lindau, F.; Werin, S.; Curbis, F.

    2009-01-01

    The thermionic RF gun using a BaO cathode at the MAX-lab linac injector has been successfully commissioned for additional operation as a photocathode gun. By retaining the BaO cathode, lowering the temperature below thermal emission and illuminating it with a UV (263 nm) 9 ps laser pulse a reduced emittance and enhanced emission control has been achieved. Measurements show a normalised emittance of 5.5 mm mrad at 200 pC charge and a maximum quantum efficiency of 1.1x10 -4 . The gun is now routinely switched between storage ring injections in thermionic mode and providing a beam for the MAX-lab test FEL in photocathode mode.

  13. Expression of Gast, Cckbr, Reg1α genes in rat duodenal epithelial cells upon long-term gastric hypoacidity and after a multiprobiotic administration

    Directory of Open Access Journals (Sweden)

    Dranitsina A. S.

    2014-11-01

    Full Text Available Aim. Determination of the Cckbr, Gast and Reg1α genes expression in rat duodenal epithelial cells upon long- term hypoacidity and with the administration of the multiprobiotic Symbiter. Methods. The experiments were carried out on white non-strain male rats. The hypoacidic state was induced through intraperitoneal injection of omeprazole for 28 days. The level of genes expression was determined by semi-quantitative analysis with RT-PCR Results. The elevation of mRNA levels of the Cckbr and Gast genes in rat duodenal villus and crypt epitheliocytes, the increased expression of the Reg1A gene in crypt epithelial cells were shown as well as the appearance of the Reg1a gene expression in villus epitheliocytes upon hypoacidic conditions were shown. The content of mRNAs of the above mentioned genes decreased or remained at the control level upon the treatment of hypoacidic rats with the multiprobiotic Symbiter. Conclusions. Long-term gastric hypoacidity is accompanied by the changes in expression of the Cckbr, Gast and Reg1a genes in rat duodenum, whereas upon administration of the multiprobiotic Symbiter the pattern of studied gene expression did not changed in the most cases.

  14. Long pulse, plasma cathode E-gun

    International Nuclear Information System (INIS)

    Goebel, D.M.; Schumacher, R.W.; Watkins, R.M.

    1993-01-01

    A unique, long-pulse E-gun has been developed for high-power tube applications. The Hollow-Cathode-Plasma (HCP) E-gun overcomes the limitations of conventional thermionic-cathode guns that have limited current density (typically ≤ 10 A/cm 2 ) or field-emission guns that offer high current density but suffer from short pulsewidth capability (typically 50 A/cm 2 ), long-pulse operation without gap closure, and also requires no cathode-heater power. The gun employs a low-pressure glow discharge inside a hollow cathode (HC) structure to provide a stable, uniform plasma surface from which a high current-density electron beam can be extracted. The plasma density is controlled by a low-voltage HC discharge pulser to produce the desired electron current density at the first grid of a multi-grid accelerator system. A dc high-voltage electron-beam supply accelerates the electrons across the gap, while the HC pulser modulates the beam current to generate arbitrary pulse waveforms. The electron accelerator utilizes a multi-aperture array that produces a large area, high perveance (>35 μpervs) beam consisting initially of many individual beamlets. The E-beam is normally operated without an applied magnetic field in the ion-focused regime, where the plasma produced by beam ionization of a background gas space-charge neutralizes the beam, and the Bennett self-pinch compresses the beamlets and increases the current density. The self-pinched beam has been observed to propagate over a meter without beam breakup or instabilities. The HCP E-gun has been operated at voltages up to 150 kV, currents up to 750 A, and pulse lengths of up to 120 μsec

  15. Improved DC Gun and Insulator Assembly

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-11

    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.

  16. Low Energy Electron Gun on Board a Scientific Satellite GEOTAIL

    OpenAIRE

    TSUTSUI, Minoru; ONISHI, Yoshiaki; MATSUMOTO, Hiroshi; KIMURA, Iwane; 筒井, 稔; 大西, 嘉昭; 松本, 紘; 木村, 磐根

    1988-01-01

    A low energy electron gun to be used for beam-plasma interaction experiments by a scientific satellite GEOTAIL has been designed and manufactured. Electrodes of the gun have been modified from the Pierce type gun because of the use of a directly heated cathode. Spatial density distributions of beam electrons emitted from the new gun have been measured in a large vacuum chamber, and characteristic curves of emission currents for some beam energies and cathode powers have been checked repeatedl...

  17. Gun utopias? Firearm access and ownership in Israel and Switzerland

    OpenAIRE

    Rosenbaum, Janet

    2011-01-01

    The 2011 attempted assassination of a US representative renewed the national gun control debate. Gun advocates claim that mass-casualty events are mitigated and deterred with three policies: (1) permissive gun laws, (2) widespread gun ownership, (3) encouragement of armed civilians who can intercept shooters, and 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 m...

  18. Hepatic expression of heme oxygenase-1 and antioxidant response element-mediated genes following administration of ethinyl estradiol to rats

    International Nuclear Information System (INIS)

    Morio, Lisa A.; Leone, Angelique; Sawant, Sharmilee P.; Nie, Alex Y.; Brandon Parker, J.; Taggart, Peter; Barron, Alfred M.; McMillian, Michael K.; Lord, Peter

    2006-01-01

    Heme oxygenase-1 (HO-1) is one of several enzymes induced by hepatotoxicants, and is thought to have an important protective role against cellular stress during liver inflammation and injury. The objective of the present study was to evaluate the role of HO-1 in estradiol-induced liver injury. A single dose of ethinyl estradiol (500 mg/kg, po) resulted in mild liver injury. Repeated administration of ethinyl estradiol (500 mg/kg/day for 4 days, po) resulted in no detectable liver injury or dysfunction. Using RT-PCR analysis, we demonstrate that HO-1 gene expression in whole liver tissue is elevated (> 20-fold) after the single dose of ethinyl estradiol. The number and intensity of HO-1 immunoreactive macrophages were increased after the single dose of ethinyl estradiol. HO-1 expression was undetectable in hepatic parenchymal cells from rats receiving Methocel control or a single dose of ethinyl estradiol, however cytosolic HO-1 immunoreactivity in these cells after repeated dosing of ethinyl estradiol was pronounced. The increases in HO-1 mRNA and HO-1 immunoreactivity following administration of a single dose of ethinyl estradiol suggested that this enzyme might be responsible for the observed protection of the liver during repeated dosing. To investigate the effect of HO-1 expression on ethinyl estradiol-induced hepatotoxicity, rats were pretreated with hemin (50 μmol/kg, ip, a substrate and inducer of HO-1), with tin protoporphyrin IX (60 μmol/kg, ip, an HO-1 inhibitor), or with gadolinium chloride (10 mg/kg, iv, an inhibitor/toxin of Kupffer cells) 24 h before ethinyl estradiol treatment. Pretreatment with modulators of HO-1 expression and activity had generally minimal effects on ethinyl estradiol-induced liver injury. These data suggest that HO-1 plays a limited role in antioxidant defense against ethinyl estradiol-induced oxidative stress and hepatotoxicity, and suggests that other coordinately induced enzymes are responsible for protection observed with

  19. Trapping of gun-injected plasma by a tokamak

    International Nuclear Information System (INIS)

    Leonard, A.W.; Dexter, R.N.; Sprott, J.C.

    1986-01-01

    It is shown that a plasma produced by a Marshall gun can be injected into and trapped by a tokamak plasma. Gun injection raises the line-averaged density and peaks the density profile. Trapping of the gun-injected plasma is explainable in terms of a depolarization current mechanism

  20. Should Gun Safety Be Taught in Schools? Perspectives of Teachers

    Science.gov (United States)

    Obeng, Cecilia

    2010-01-01

    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…

  1. Gun Violence and Children: Factors Related To Exposure and Trauma.

    Science.gov (United States)

    Slovak, Karen

    2002-01-01

    Study investigated relationship between access to firearms and parental monitoring on rural youths' exposure to gun violence, and examined the effect of gun violence exposure on mental health. Results indicated a substantial number were exposed to gun violence. Exposure was related to firearm access and parental monitoring. Implications for social…

  2. 78 FR 11902 - Review of Gun Safety Technologies

    Science.gov (United States)

    2013-02-20

    ... DEPARTMENT OF JUSTICE Office of Justice Programs [OJP (NIJ) Docket No. 1615] Review of Gun Safety...'s Plan to reduce gun violence released on January 16, 2013, the U.S. Department of Justice, Office... emerging gun safety technologies and plans to issue a report on the availability and use of those...

  3. Klystron - Space-charge limited flow, guns, Perveance

    International Nuclear Information System (INIS)

    Isagawa, S.

    1999-01-01

    This paper treats Thermionic emission, Cathode as an e - emitter, Space-charge limited effect and 3/2 power law, Perveance, Beam spread due to space charge, Pierce guns, Magnetically immersed guns, Method of gun design including simulations, and Examples, mainly treating E3786, which attendees will operate above 1 MW-CW in a practical exercise course at KEK. (author). 74 refs

  4. A compact electron gun using field emitter array

    International Nuclear Information System (INIS)

    Asakawa, M.R.; Ikeda, A.; Miyabe, N.; Yamaguchi, S.; Kusaba, M.; Tsunawaki, Y.

    2008-01-01

    A compact electron gun using field emitter array has been developed. With a simple triode configuration consisting of FEA, mid-electrode and anode electrode, the electron gun produces a parallel beam with a diameter of 0.5 mm. This electron gun is applicable for compact radiation sources such as Cherenkov free-electron lasers

  5. The design of gridded pierce guns for accelerators

    International Nuclear Information System (INIS)

    True, R.

    1985-01-01

    It is vital to employ ultra-laminar beams in electron linacs to maximize charge transport to the target. This paper presents numerical and experimental design techniques which have led to significant improvements in gridded Pierce guns used in microwave tubes and electron linacs. The paper concludes with two gun/injector concepts which have demonstrated enhanced performance over standard triode Pierce guns

  6. Youth, Guns, and the Juvenile Justice System. Research Report.

    Science.gov (United States)

    Butts, Jeffrey; Coggeshall, Mark; Gouvis, Caterina; Mears, Daniel; Travis, Jeremy; Waul, Michelle; White, Ruth

    This report documents trends in youth gun violence and the response within the justice system, noting the growing variety of data resources available to investigate the effect of new gun laws on youth, communities, and public safety. The first section reviews recent trends, examining the major wave of gun violence in the United States during the…

  7. Study of Control Grid Thermionic Cathode RF Gun

    CERN Document Server

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

    2004-01-01

    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.

  8. 78 FR 66840 - Revocation of Certain Requirements Pertaining to Caps Intended for Use With Toy Guns and Toy Guns...

    Science.gov (United States)

    2013-11-07

    ... Certain Requirements Pertaining to Caps Intended for Use With Toy Guns and Toy Guns Not Intended for Use With Caps AGENCY: Consumer Product Safety Commission. ACTION: Final rule. SUMMARY: Section 106 of the... regulations pertaining to caps intended for use with toy guns refer to obsolete equipment, but the ASTM F963...

  9. Reconnection conditions for a coaxial plasma gun

    International Nuclear Information System (INIS)

    Berk, H.L.; Hammer, J.H.; Shearer, J.W.

    1982-01-01

    A fluid model for the flow conditions necessary to form a compact torus from the plasma ejected by a coaxial plasma gun is developed. This is done by finding the conditions for which the steady-flow equations break down. Results are found for two cases; variable external flux and variable outer-wall radius

  10. Electron gun for the positron generator

    International Nuclear Information System (INIS)

    Fukuda, S.; Ogawa, Y.; Saito, Y.

    1986-01-01

    A triode electron gun has been installed on the Positron Generator at KEK, and brought into test operation. It involves a grid-cathode assembly currently used in a planner triode. The cathode has a diameter of 10 mm and is coated with Ba-Sr-Ca oxide. Because of the short grid-cathode distance (0.18 mm), the relatively low grid pulse voltages makes it possible to draw a high current. The assembly has a small vacuum flange which allows its easy replacement. Emission current from the oxide cathode is sensitive to residual gases, therefore, the vacuum system is carefully made and the pressure is kept in the range of 10 -9 Torr even when the accelerator is on. The grid pulser is a line type pulser using multi-stage avalanche transistors as a switch. The pulse width of 10 nsec has been used for the test to investigate the gun characteristics. The performance of the gun has been tested with this pulser and the emission current of 9.7 A was achieved at an injection voltage of 110 kV. The characteristics of the gun are described together with the beam trace

  11. Guns on Campus: A Chilling Effect

    Science.gov (United States)

    Mash, Kenneth M.

    2013-01-01

    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…

  12. College Students Opinions on Gun Violence.

    Science.gov (United States)

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

    2016-06-01

    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.

  13. Cerebral damage caused by nail gun injury

    Directory of Open Access Journals (Sweden)

    Andersen Chris Hedeman

    2016-06-01

    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.

  14. A device for electron gun emittance measurement

    International Nuclear Information System (INIS)

    Aune, B.; Corveller, P.; Jablonka, M.; Joly, J.M.

    1985-05-01

    In order to improve the final emittance of the beam delivered by the ALS electron linac a new gun is going to be installed. To measure its emittance and evaluate the contribution of different factors to emittance growth we have developed an emittance measurement device. We describe the experimental and mathematical procedure we have followed, and give some results of measurements

  15. Development of the Antares electron gun

    International Nuclear Information System (INIS)

    Stine, R.; Leland, W.; Mansfield, C.; Rosocha, L.; Jansen, J.; Gibson, R.; Allen, G.

    1984-01-01

    Antares is the Los Alamos National Laboratory 40-kJ, 1-ns, CO 2 laser system that is now operational. This laser system was developed for the Intertial Confinement Fusion (ICF) program and is beginning target experiments. The distributed circuit modeling, design and operation of the large electron gun developed for the final laser power amplifier are reviewed. This gun is significant because of the large electron current area, 9 m 2 ; the number of emitter blades, 48; the dual cathode current return; and the coaxial geometry and grid control. The gun components and their development are discussed. These include the emitter blades, the coaxial grid (to maintain constant electron current during the 5-μs pulse), the bonded stacked-ring insulator (to electrically insulate the grid/cathode), the Kapton/aluminum electron transmission windows (to provide an interface between gun vacuum and laser gas) and the vacuum shell (operated at a vacuum of 10 -6 torr). A unique pressure diagnostic is also discussed

  16. Capital Punishment, Gun Ownership, and Homicide.

    Science.gov (United States)

    Kleck, Gary

    1979-01-01

    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)

  17. Traveling-wave synchronous coil gun

    International Nuclear Information System (INIS)

    Elliott, D.G.

    1991-01-01

    This paper reports on a traveling-wave synchronous coil gun which permits independent adjustment of the magnetic field and armature current for high velocity at low armature mass fraction. Magnetic field energy is transferred from the rear of the wave to the front without passing through the power supply. Elaborate switching is required

  18. A high current high frequency ions gun

    International Nuclear Information System (INIS)

    Coutant, J.; Prevot, F.; Vienet, R.

    1959-01-01

    A 10 mA protons gun has been developed for different purposes. The first part of the report studies the plasma production with a RF electromagnetic field. Then the ion extraction process is analysed with particular reference to space charge phenomena. The last part describes a three electrode electrostatic lens which focusses the beam. (author) [fr

  19. Performance of photocathode rf gun electron accelerators

    International Nuclear Information System (INIS)

    Ben-Zvi, I.

    1993-01-01

    In Photo-Injectors (PI) electron guns, electrons are emitted from a photocathode by a short laser pulse and then accelerated by intense rf fields in a resonant cavity. The best known advantage of this technique is the high peak current with a good emittance (high brightness). This is important for short wavelength Free-Electron Lasers and linear colliders. PIs are in operation in many electron accelerator facilities and a large number of new guns are under construction. Some applications have emerged, providing, for example, very high pulse charges. PIs have been operated over a wide range of frequencies, from 144 to 3000 MHz (a 17 GHz gun is being developed). An exciting new possibility is the development of superconducting PIs. A significant body of experimental and theoretical work exists by now, indicating the criticality of the accelerator elements that follow the gun for the preservation of the PI's performance as well as possible avenues of improvements in brightness. Considerable research is being done on the laser and photocathode material of the PI, and improvement is expected in this area

  20. How Sociology Texts Address Gun Control

    Science.gov (United States)

    Tonso, William R.

    2004-01-01

    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…

  1. Green plasticizers for multibase gun propellants (Lecture)

    NARCIS (Netherlands)

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

    2007-01-01

    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,

  2. The electron gun for the Daresbury SRS linac

    International Nuclear Information System (INIS)

    Dykes, D.M.

    1996-01-01

    The electron gun for the Daresbury SRS linac injector has been modified to use the cathode-grid assembly from the Eimac planar triode 8755. The gun now has improved beam characteristics, is more reliable and the cathode assembly is quicker and easier to change. This paper describes the assembly of the electron gun, and then the re-conditioning of the cathode highlighting the vacuum environment. The action of the grid modulation system on the electron beam, which pre-bunches the electron beam, is described, and typical gun characteristics are shown. Proposed developments to the gun system are discussed. (author)

  3. Performance of a carbon nanotube field emission electron gun

    Science.gov (United States)

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

    2007-04-01

    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.

  4. Acute Alcohol Consumption, Alcohol Outlets, and Gun Suicide

    Science.gov (United States)

    Branas, Charles C.; Richmond, Therese S.; Ten Have, Thomas R.; Wiebe, Douglas J.

    2014-01-01

    A case–control study of 149 intentionally self-inflicted gun injury cases (including completed gun suicides) and 302 population-based controls was conducted from 2003 to 2006 in a major US city. Two focal independent variables, acute alcohol consumption and alcohol outlet availability, were measured. Conditional logistic regression was adjusted for confounding variables. Gun suicide risk to individuals in areas of high alcohol outlet availability was less than the gun suicide risk they incurred from acute alcohol consumption, especially to excess. This corroborates prior work but also uncovers new information about the relationships between acute alcohol consumption, alcohol outlets, and gun suicide. Study limitations and implications are discussed. PMID:21929327

  5. Development of the electron gun control system of SSRF

    International Nuclear Information System (INIS)

    Zhou Dayong; Lin Guoqiang; Liu Dekang; Shen Liren

    2010-01-01

    An electron gun is the key part of a linac, the beam quality of which depends on beam quality of the electron gun, hence the need of a stable control system of the electron gun to ensure its safe operation.In this paper, we report our progresses in developing the linac's electron gun control system of Shanghai Synchrotron Radiation Facility (SSRF). It uses PLC as the device controllers, with the monitoring software developed on EPICS. The whole system is connected by Ethernet. The PLC and Ethernet technology ensures good reliability and easy maintenance of the electron gun control system. (authors)

  6. Patterns of gun deaths across US counties 1999-2013.

    Science.gov (United States)

    Kalesan, Bindu; Galea, Sandro

    2017-05-01

    We examined the socio-demographic distribution of gun deaths across 3143 counties in 50 United States' states to understand the spatial patterns and correlates of high and low gun deaths. We used aggregate counts of gun deaths and population in all counties from 1999 to 2013 from the Centers for Disease Control and Prevention's Wide-ranging Online Data for Epidemiologic Research (WONDER). We characterized four levels of gun violence, as distinct levels of gun death rates of relatively safe, unsafe, violent, and extremely violent counties, based on quartiles of 15-year county-specific gun death rates per 100,000 and used negative binomial regression models allowing clustering by state to calculate incidence rate ratios and 95% confidence intervals (95% CIs). Most states had at least one violent or extremely violent county. Extremely violent gun counties were mostly rural, poor, predominantly minority, had high unemployment rate and homicide rate. Overall, homicide rate was significantly associated with gun deaths (incidence rate ratios = 1.08, 95% CI = 1.06-1.09). In relatively safe counties, this risk was 1.09 (95% CI = 1.05-1.13) and in extremely violent gun counties was 1.03 (95% CI = 1.03-1.04). There are broad differences in gun death rates across the United States representing different levels of gun death rates in each state with distinct socio-demographic profiles. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Association Between Substance Use and Gun-Related Behaviors.

    Science.gov (United States)

    Chen, Danhong; Wu, Li-Tzy

    2016-01-01

    Gun-related violence is a public health concern. This study synthesizes findings on associations between substance use and gun-related behaviors. Searches through PubMed, Embase, and PsycINFO located 66 studies published in English between 1992 and 2014. Most studies found a significant bivariate association between substance use and increased odds of gun-related behaviors. However, their association after adjustment was mixed, which could be attributed to a number of factors such as variations in definitions of substance use and gun activity, study design, sample demographics, and the specific covariates considered. Fewer studies identified a significant association between substance use and gun access/possession than other gun activities. The significant association between nonsubstance covariates (e.g., demographic covariates and other behavioral risk factors) and gun-related behaviors might have moderated the association between substance use and gun activities. Particularly, the strength of association between substance use and gun activities tended to reduce appreciably or to become nonsignificant after adjustment for mental disorders. Some studies indicated a positive association between the frequency of substance use and the odds of engaging in gun-related behaviors. Overall, the results suggest a need to consider substance use in research and prevention programs for gun-related violence. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Gun utopias? Firearm access and ownership in Israel and Switzerland.

    Science.gov (United States)

    Rosenbaum, Janet E

    2012-02-01

    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. Progress on a cryogenically cooled RF gun polarized electron source

    Energy Technology Data Exchange (ETDEWEB)

    Fliller, R.P., III; Edwards, H.; /Fermilab

    2006-08-01

    RF guns have proven useful in multiple accelerator applications. An RF gun capable of producing polarized electrons is an attractive electron source for the ILC or an electron-ion collider. Producing such a gun has proven elusive. The NEA GaAs photocathode needed for polarized electron production is damaged by the vacuum environment in an RF gun. Electron and ion back bombardment can also damage the cathode. These problems must be mitigated before producing an RF gun polarized electron source. In this paper we report continuing efforts to improve the vacuum environment in a normal conducting RF gun by cooling it with liquid nitrogen after a high temperature vacuum bake out. We also report on a design of a cathode preparation chamber to produce bulk GaAs photocathodes for testing in such a gun. Future directions are also discussed.

  10. Dietary administration of the probiotic SpPdp11: Effects on the intestinal microbiota and immune-related gene expression of farmed Solea senegalensis treated with oxytetracycline.

    Science.gov (United States)

    Tapia-Paniagua, S T; Vidal, S; Lobo, C; García de la Banda, I; Esteban, M A; Balebona, M C; Moriñigo, M A

    2015-10-01

    Few antimicrobials are currently authorised in the aquaculture industry to treat infectious diseases. Among them, oxytetracycline (OTC) is one of the first-choice drugs for nearly all bacterial diseases. The objective of this study was to evaluate the effect of the dietary administration of OTC both alone and jointly with the probiotic Shewanella putrefaciens Pdp11 (SpPdp11) on the intestinal microbiota and hepatic expression of genes related to immunity in Senegalese sole (Solea senegalensis) juveniles. The results demonstrated that the richness and diversity of the intestinal microbiota of fish treated with OTC decreased compared with those of the control group but that these effects were lessened by the simultaneous administration of SpPdp11. In addition, specimens that received OTC and SpPdp11 jointly showed a decreased intensity of the Denaturing Gradient Gel Electrophoresis (DGGE) bands related to Vibrio genus and the presence of DGGE bands related to Lactobacillus and Shewanella genera. The relationship among the intestinal microbiota of fish fed with control and OTC diets and the expression of the NADPH oxidase and CASPASE-6 genes was demonstrated by a Principal Components Analysis (PCA) carried out in this study. In contrast, a close relationship between the transcription of genes, such as NKEF, IGF-β, HSP70 and GP96, and the DGGE bands of fish treated jointly with OTC and SpPdp11 was observed in the PCA study. In summary, the results obtained in this study demonstrate that the administration of OTC results in the up-regulation of genes related to apoptosis but that the joint administration of OTC and S. putrefaciens Pdp11 increases the transcription of genes related to antiapoptotic effects and oxidative stress regulation. Further, a clear relationship between these changes and those detected in the intestinal microbiota is established. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Single administration of recombinant IL-6 restores the gene expression of lipogenic enzymes in liver of fasting IL-6-deficient mice

    DEFF Research Database (Denmark)

    Gavito, A L; Cabello, R; Suarez, J

    2016-01-01

    BACKGROUND AND PURPOSE: Lipogenesis is intimately controlled by hormones and cytokines as well as nutritional conditions. IL-6 participates in the regulation of fatty acid metabolism in the liver. We investigated the role of IL-6 in mediating fasting/re-feeding changes in the expression of hepatic...... lipogenic enzymes. EXPERIMENTAL APPROACH: Gene and protein expression of lipogenic enzymes were examined in livers of wild-type (WT) and IL-6-deficient (IL-6(-/-) ) mice during fasting and re-feeding conditions. Effects of exogenous IL-6 administration on gene expression of these enzymes were evaluated...

  12. A Comparative Analysis of Crime Guns

    Directory of Open Access Journals (Sweden)

    Megan E. Collins

    2017-10-01

    Full Text Available Information is limited on how firearms move from legal possession to illegal possession and use in criminal activities, largely because of data collection capacity and a lack of recent, exhaustive recovery data across jurisdictions. This article includes both an analysis of firearms trace data and prisoner interviews across multiple jurisdictions: New Orleans, Louisiana, Prince George’s County, Maryland, and Chicago, Illinois. Findings indicate that recoveries and trace successes vary across jurisdictions and by type of crime. Jurisdiction regulations were associated with the proportion of guns purchased in state and time to recovery but not with purchaser characteristics. Interviews from imprisoned offenders in two jurisdictions revealed the most common method of obtaining a crime gun was to steal it or buy it off the street.

  13. Instantaneous current and field structure of a gun-driven spheromak for two gun polarities

    International Nuclear Information System (INIS)

    Woodruff, S; Nagata, M

    2002-01-01

    The instantaneous plasma structure of the SPHEX spheromak is determined here by numerically processing data from insertable Rogowski and magnetic field probes. Data is presented and compared for two modes of gun operation: with the central electrode biased positively and negatively. It is found that while the mean-, or even instantaneous-, field structure would give the impression of a roughly axisymmetric spheromak, the instantaneous current structure does not. Hundred per cent variations in J measured at the magnetic axis can be explained by the rotation of a current filament that has a width equal to half of the radius of the flux-conserving first wall. In positive gun operation, current leaves the filament in the confinement region leading to high wall current there. In negative gun operation, wall current remains low as all injected current returns to the gun through the plasma. The plasma, in either instance, is strongly asymmetric. We discuss evidence for the existence of the current filament in other gun-driven spheromaks and coaxial plasma thrusters

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

    Science.gov (United States)

    Ruggles, Kelly V; Rajan, Sonali

    2014-01-01

    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. 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. 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.

  15. Development of a Gun Wear Data Bank.

    Science.gov (United States)

    1979-11-01

    GO TO 3 INC.(j)zI 3 CONTINUE *4OLS=MF( ICCIr RETURN ENTRY SEL4 Jug C0 4 IIRKIN,IRPAX IJ=79 .AND. ISERS (1,1) 00 5 19219" IF (ZJ *EO. KODE (19)) GO TO 6... SEL4 will find data for each requested gun that also meets the requirements for selected records. 2. SUBROUTINE RBU will unpack velocity data for a

  16. Co-axial electrodes gun characteristics

    International Nuclear Information System (INIS)

    Masoud, M.M.; Soliman, H.M.

    1981-01-01

    A coaxial electrodes gun is constructed with inner electrode diameter of 3.2 cm; outer electrode diameter of 6.6 cm and length of 25 cm it is connected to a condenser bank which delivers 4 K joule stored energy. The maximum power of the discharge is equal to 4.5x10 4 K watt; for 5 KV charging voltage. The inductance showed two main peak values of 0.257μH and 0.27μH. Theoretical calculations using one-dimension-single fluid model is μ sed, which shows that the maximum acceleration is at 0.5 sec, and the gas breakdown takes place at the gun breech; at the start of the discharge, will leave the gun after 1.625μ sec, also the drift velocity, the force and the magnetic field are given. The measured results show quite reasonable agreement with the calculations for most of the results, and the position of the plasma sheath inside the gun slightly deviated from the theoretical calculations due to viscosity and wall interaction, as well as other parameters which did not be take into consideration. The plasma current density of the sheath has its maximum value at Z=18 cm, the plasma will leave the coaxial source after 1.5μ sec, from the start of the discharge, which conferms with the theoretical model. Resistance of the gas between the electrodes, changes with time according to the particle injected from this source, and the maximum efficiency of the installation for charging voltage 5kV and pressure 80μ Hg is at approx.=10μ sec and 20.5μ sec

  17. Cost Estimate for Gun Liner Emplacement

    Science.gov (United States)

    2011-08-01

    excellent material to resist wear and erosion in gun tubes, it is applied by an electrolytic process that involves hexavalent chromium, a known carcinogen...A recent Department of Defense memorandum has strongly urged that, wherever possible, processes involving hexavalent chromium be eliminated from...might be affordable.) Other refractory metals, such as the Stellite series, BioDur CCM* (a cobalt, chrome , molybdenum alloy), or niobium are less

  18. Magnetic guns with cylindrical permanent magnets

    Czech Academy of Sciences Publication Activity Database

    Vokoun, David; Beleggia, M.; Heller, Luděk

    2012-01-01

    Roč. 324, č. 9 (2012), s. 1715-1719 ISSN 0304-8853 R&D Projects: GA ČR(CZ) GAP107/11/0391; GA AV ČR IAA100100920 Institutional research plan: CEZ:AV0Z10100520 Keywords : permanent magnet * cylindrical magnet * Earnshaw's theorem * magnetic gun * magnetostatic interaction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.826, year: 2012 http://www.sciencedirect.com/science/article/pii/S0304885311008997

  19. Gun Laws and Crime: An Empirical Assessment

    OpenAIRE

    Matti Viren

    2012-01-01

    This paper deals with the effect of gun laws on crime. Several empirical analyses are carried to investigate the relationship between five different crime rates and alternative law variables. The tests are based on cross-section data from US sates. Three different law variables are used in the analysis, together with a set of control variables for income, poverty, unemployment and ethnic background of the population. Empirical analysis does not lend support to the notion that crime laws would...

  20. 46 CFR 160.031-4 - Equipment for shoulder gun type line-throwing appliance.

    Science.gov (United States)

    2010-10-01

    ... 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) One...

  1. Gas Gun Studies of Interface Wear Effects

    Science.gov (United States)

    Jackson, Tyler; Kennedy, Greg; Thadhani, Naresh

    2011-06-01

    The characteristics of interface wear were studied by performing gas gun experiments at velocities up to 1 km/s. The approach involved developing coefficients of constitutive strength models for Al 6061 and OFHC-Cu, then using those to design die geometry for interface wear gas gun experiments. Taylor rod-on-anvil impact experiments were performed to obtain coefficients of the Johnson-Cook constitutive strength model by correlating experimentally obtained deformed states of impacted samples with those predicted using ANSYS AUTODYN hydrocode. Simulations were used with validated strength models to design geometry involving acceleration of Al rods through a copper concentric cylindrical angular extrusion die. Experiments were conducted using 7.62 mm and 80 mm diameter gas guns. Differences in the microstructure of the interface layer and microhardness values illustrate that stress-strain conditions produced during acceleration of Al through the hollow concentric copper die, at velocities less than 800 m/s, result in formation of a layer via solid state alloying due to severe plastic deformation, while higher velocities produce an interface layer consisting of melted and re-solidified aluminum.

  2. HMX based enhanced energy LOVA gun propellant

    Energy Technology Data Exchange (ETDEWEB)

    Sanghavi, R.R. [High Energy Materials Research Laboratory, Pune 411021 (India)]. E-mail: sanghavirr@yahoo.co.uk; Kamale, P.J. [High Energy Materials Research Laboratory, Pune 411021 (India); Shaikh, M.A.R. [High Energy Materials Research Laboratory, Pune 411021 (India); Shelar, S.D. [High Energy Materials Research Laboratory, Pune 411021 (India); Kumar, K. Sunil [High Energy Materials Research Laboratory, Pune 411021 (India); Singh, Amarjit [High Energy Materials Research Laboratory, Pune 411021 (India)

    2007-05-08

    Efforts to develop gun propellants with low vulnerability have recently been focused on enhancing the energy with a further improvement in its sensitivity characteristics. These propellants not only prevent catastrophic disasters due to unplanned initiation of currently used gun propellants (based on nitrate esters) but also realize enhanced energy levels to increase the muzzle velocity of the projectiles. Now, in order to replace nitroglycerine, which is highly sensitive to friction and impact, nitramines meet the requirements as they offer superior energy due to positive heat of formation, typical stoichiometry with higher decomposition temperatures and also owing to negative oxygen balance are less sensitive than stoichiometrically balanced NG. RDX has been widely reported for use in LOVA propellant. In this paper we have made an effort to present the work on scantily reported nitramine HMX based LOVA gun propellant while incorporating energetic plasticizer glycidyl azide polymer to enhance the energy level. HMX is known to be thermally stable at higher temperature than RDX and also proved to be less vulnerable to small scale shaped charge jet attack as its decomposition temperature is 270 deg. C. HMX also offers improved impulse due to its superior heat of formation (+17 kcal/mol) as compared to RDX (+14 kcal/mol). It has also been reported that a break point will not appear until 35,000 psi for propellant comprising of 5 {mu}m HMX. Since no work has been reported in open literature regarding replacement of RDX by HMX, the present studies were carried out.

  3. The HART I augmented electric gun facility

    International Nuclear Information System (INIS)

    Fikse, D.A.; Ciesar, J.A.; Wehrli, H.A.; Rimersma, H.; Docherty, E.F.; Pipich, C.W.

    1991-01-01

    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 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

  4. Electromagnetic compression gun for hypervelocity projectile acceleration

    International Nuclear Information System (INIS)

    Woo, J.T.

    1987-01-01

    The rapid acceleration of projectiles to very high velocities has applications in many areas. The general requirements for an effective system is simplicity, reliability, compactness and good efficiency. The authors developed a concept by using electromagnetic forces to compressionally heat a plasma to high temperature and pressure to serve as the propellant for the acceleration of projectiles. The concept shares the simplicity of the light gas gun, but because of the high temperature of the propellant, is capable of significantly higher performance. Unlike the electrothermal gun approach to raise the propellant temperature by resistive heating, the electromagnetic concept is more efficient at higher temperatures. Operationally, the concept resembles a railgun in requiring a large pulsed current to drive the system. However, the current flow in this case is entirely external to the gun barrel and is axisymmetric. Therefore, many of the problems associated with railgun operations are avoided. Furthermore, because the current channel is external, there is also greater flexibility in the choice of load impedance to match to the power supply. The concept can also be generalized to a multi-stage regenerative system driven by a pulse forming network to resemble a coaxial accelerator

  5. Experimental Studies of Electrothermal Plasma Gun

    International Nuclear Information System (INIS)

    Diab, F.B.A.

    2013-01-01

    The aim of the present work is to study the capillary plasma discharge dynamics and characteristics. The capillary plasma device is a new technology for producing high density plasma after ablating the capillary wall using a pulsed electric power. An Electrothermal Plasma Gun (ETG) is composed of a capillary discharge tube made of Teflon operated with simple RLC circuit. The device called Electrothermal Gun (ETG) which is composed of 4 capacitors (70 μF, 10 kV, 1.28 μH) connected in parallel to a plasma source by means of one high power supply. The gun was operated in open air at discharge energies between 35 J - 3.5 kJ according to charging voltage. The work presented in this thesis covers the following items, 1- Measurements of the basic parameters and characterizations of the pretest results of the electrical circuits and capillary plasma discharge using Rogowski coil, voltage probe and Photomultiplier. 2- Material processing including (physics of the surface modifications, the morphology of the surface by using Scanning Electron Microscope (SEM) at different conditions, compositions of the materials by using X-ray Fluorescence (XRF), Micro hardness test and material particle deposition.

  6. Preparation of targets using electron gun systems

    International Nuclear Information System (INIS)

    Maier-Komor, P.

    1975-01-01

    Most targets of isotopes with very low vapor pressure can only be fabricated by vacuum deposition using an electron gun system or a heavy ion sputtering system. Heavy ion sputtering is a very new technique with many unsolved problems. Therefore it seems to be easier to work with an electron gun. Different commercially available electron guns, which are all designed for the high evaporation rates used in industry, are examined for their qualification in processing small amounts of material as used in fabrication of isotope targets. Electron backscattering and the associated efficiency of the electron beam power is strongly dependent on the atomic number Z of the evaporant and the incident angle of the electron beam on the surface of the evaporant. This dependence leads also to the undesired effects to the target layers from electrons and ions. Some precautions are necessary against the effects of the electrons and ions, which are formed in the plasma directly over the beam impact point. Beam power and beam density have to be chosen to get a constant evaporation rate and a low enough condensation rate in order not to overheat the target substrates. To evaporate some metals it may be helpful to pulse the electron beam

  7. 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

    2005-01-01

    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.

  8. 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

    2005-01-01

    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...

  9. THE IMPROVEMENT AND APPLICATION OF EI-GUN (ELECTRICAL INSEMINATION GUN FOR ARTIFICIAL INSEMINATION (AI USING GOAT FRESH SEMEN

    Directory of Open Access Journals (Sweden)

    Mirsa Ita Dewi

    2017-03-01

    Full Text Available Electrical Insemination Gun (EI-GUN was a tool for Artificial Insemination (AI using fresh semen with an electric control system. The research objective was to produced EI-GUN for AI using fresh semen on small ruminants (goat. The research was conducted from March to June 2015. The process of EI-GUN creation implemented in Design and Prototype Laboratory and Aero Modeling Research Laboratory at Engineering Faculty, University of Brawijaya (UB. Testing tools EI-GUN on goat was conducted in the Sumber Sekar Laboratory, Animal Husbandry Faculty, UB.  The methods of research were literature study, tool specification determination, designing EI-GUN, running test, semen evaluation passed EI-GUN and application on Goat. EI-GUN has seven important parts, which supports each other in this operating system. Those parts consist of stylet, servo, system controlled, insemination pump, connecting rod, battery, and holder. EI-GUN work system sucked the semen into insemination pump as much as 5 ml, and release the semen 0.25 ml appropriate standard of AI. It was applicable for 20 times AI. The results showed that the cell motility of spermatozoa ≥ 70% were still in ranging of Indonesian National Standard (SNI.   Keywords: artificial insemination, EI-GUN, fresh semen.

  10. The Development of the Linac Coherent Light Source RF Gun

    International Nuclear Information System (INIS)

    Dowell, D

    2008-01-01

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of

  11. Goods for Guns--the use of a gun buyback as an injury prevention/community education tool.

    Science.gov (United States)

    McGuire, Margaret; Manno, Mariann; Rook, Allison; Maranda, Louise; Renaud, Elizabeth; DeRoss, Anthony; Hirsh, Michael

    2011-11-01

    US children aged between 5 years and 14 years have a rate of gun-related homicide 17 times higher and a rate of gun-related suicide and unintentional firearm injury 10 times higher than other developed countries. Gun buyback programs have been criticized as ineffective interventions in decreasing violence. The Injury Free Coalition for Kids-Worcester (IFCK-W) Goods for Guns buyback is a multipronged approach to address these concerns and to reduce the number of firearms in the community. The IFCK-W buyback program is funded by corporate sponsors, grants, and individual donations. Citizens are instructed to transport guns, ammunition, and weapons safely to police headquarters on two Saturdays in December. Participants are guaranteed anonymity by the District Attorney's office and receive gift certificates for operable guns. Trained volunteers administer an anonymous survey to willing participants. Individuals who disclose having unsafely stored guns remaining at home receive educational counseling and trigger locks. Guns and ammunition are destroyed at a later time in a gun crushing ceremony. Since 2002, 1,861 guns (444 rifle/shotgun, 738 pistol/revolver, and 679 automatic/semiautomatic) have been collected at a cost of $99,250 (average, $53/gun). Seven hundred ten people have surrendered firearms, 534 surveys have been administered, and ≈ 75 trigger locks have been distributed per year. IFCK-W Goods for Guns is a relatively inexpensive injury prevention model program that removes unwanted firearms from homes, raises community awareness about gun safety, and provides high-risk individuals with trigger locks and educational counseling.

  12. Gunning for accuracy: Company targets human error with 'foolproof' perforating gun

    Energy Technology Data Exchange (ETDEWEB)

    Ross, E.

    2002-12-01

    An innovative new design for a scalloped expandable perforating gun is described. The gun is manufactured in Edmonton by LRI Perforating Systems, and it aimed at reducing the chances of human error that can result in sub-optimal performance. A perforating gun is used to pierce the well's casing to allow hydrocarbons to flow into the wellbore. It consists of a carrier, a pipe with an eighth-inch thick wall that protects the explosives downhole, and an inner tube containing the explosives. The LRI system has a unique interlocking mechanism for the end plates, which are attached to either end of the thin-walled charge holder tube, in addition to other advantageous features, including a price advantage of 10 to 15 per cent. Marketing strategy is designed to interest wi reline companies that focus on vertical well applications. 1 photo.

  13. Spheromak experiment using separate guns for formation and sustainment

    International Nuclear Information System (INIS)

    Brown, M.R.; Martin, A.

    1996-01-01

    An experiment is described that incorporates the use of separate magnetized plasma guns for formation and sustainment of a spheromak. It is shown that energy coupling efficiency approaches unity if the gun and spheromak are of comparable size. A large gun should be able to operate at lower current and therefore lower voltage. In addition, it is expected that a gun matched to the size of the spheromak will cause less perturbation to the equilibrium. It is proposed to use a smaller gun for spheromak formation and a large, efficient gun for sustainment. The theoretical basis for the experiment is developed, and the details of the experiment are described. A prediction of the equilibrium magnetic flux surfaces using the EFIT code is presented. 28 refs., 3 figs., 1 tab

  14. Recent advances in high-brightness electron guns at AES

    International Nuclear Information System (INIS)

    Bluem, H.; Todd, A.M.M.; Cole, M.D.; Rathke, J.; Schultheiss, T.

    2003-01-01

    We describe a number of active Advanced Energy Systems projects pertaining to the development of advanced, high-brightness electron guns for various applications. These projects include a fully superconducting, CW RF gun, nearing test, that utilizes the niobium surface as the photocathode material. An integrated 100 mA, low emittance DC/SRF gun, ideal as an injector for ERL-type light sources and intended as the injector for a 100 kW FEL, is in late design stage. A parallel high-power, CW, normal-conducting L-band RF gun project has just begun. The early performance analysis for this gun also shows good promise as an injector for ERL-type light sources. Lastly, a fully axisymmetric RF gun, operating in X-band, is being studied as a source of extremely bright electron bunches

  15. Status and future prospects of SRF gun developments

    International Nuclear Information System (INIS)

    Teichert, Jochen

    2006-01-01

    While the concepts of DC and normal-conducting photo-injectors are well proofed, the SRF gun development still possesses a high risk. Challenges are the thermal and contaminant isolation needed between the cathode and superconducting cavity, the choice of the right photocathode and its life time, the difficulty of coupling high-average power into the gun, and beam excitation of higher order cavity modes. But in combination with SRF linacs, the SRF guns are the best solution for high current and CW operation. Thus, several R and D projects of SRF gun have been launched. The talk will give an overview of the history and progress of the SRF gun development. In more detail the technical concept, performance, and status of the Rossendorf superconducting RF gun project, a collaboration of BESSY, DESY, MBI and FZR, will be presented. (author)

  16. Acceleration of solid pellets using a plasma gun

    International Nuclear Information System (INIS)

    Buller, T.L.; Turnbull, R.J.; Kim, K.

    1979-01-01

    The use of solid pellets of hydrogen isotopes to refuel thermonuclear fusion reactors based on the tokamak configuration will require that the pellets be accelerated to high velocities. One possible method of acceleration is to interact a fast plasma from a plasma gun with the pellets. In this paper preliminary results are given on the acceleration of solid pellets with a plasma gun. The plasma-gun requirements for successful acceleration to high velocities are discussed

  17. Revised theory of Pierce-type electron guns

    International Nuclear Information System (INIS)

    Sar-El, H.Z.

    1982-01-01

    Attempts to date to obtain the shape of the beam forming electrodes of various Pierce-type electron guns are briefly discussed with emphasis on the many discrepansis in the results of previous works. A revised theory of Pierce-type electron guns is proposed. The shapes of the beam-forming electrodes for all known configurations of Pierce guns were computed on the basis of the proposed theory. (orig.)

  18. Repeated ketamine administration alters N-methyl-d-aspartic acid receptor subunit gene expression: Implication of genetic vulnerability for ketamine abuse and ketamine psychosis in humans

    Science.gov (United States)

    Lipsky, Robert H

    2015-01-01

    For more than 40 years following its approval by the Food and Drug Administration (FDA) as an anesthetic, ketamine, a non-competitive N-methyl-d-aspartic acid (NMDA) receptor antagonist, has been used as a tool of psychiatric research. As a psychedelic drug, ketamine induces psychotic symptoms, cognitive impairment, and mood elevation, which resemble some symptoms of schizophrenia. Recreational use of ketamine has been increasing in recent years. However, little is known of the underlying molecular mechanisms responsible for ketamine-associated psychosis. Recent animal studies have shown that repeated ketamine administration significantly increases NMDA receptor subunit gene expression, in particular subunit 1 (NR1 or GluN1) levels. This results in neurodegeneration, supporting a potential mechanism where up-regulation of NMDA receptors could produce cognitive deficits in chronic ketamine abuse patients. In other studies, NMDA receptor gene variants are associated with addictive behavior. Here, we focus on the roles of NMDA receptor gene subunits in ketamine abuse and ketamine psychosis and propose that full sequencing of NMDA receptor genes may help explain individual vulnerability to ketamine abuse and ketamine-associated psychosis. PMID:25245072

  19. Repeated ketamine administration alters N-methyl-D-aspartic acid receptor subunit gene expression: implication of genetic vulnerability for ketamine abuse and ketamine psychosis in humans.

    Science.gov (United States)

    Xu, Ke; Lipsky, Robert H

    2015-02-01

    For more than 40 years following its approval by the Food and Drug Administration (FDA) as an anesthetic, ketamine, a non-competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist, has been used as a tool of psychiatric research. As a psychedelic drug, ketamine induces psychotic symptoms, cognitive impairment, and mood elevation, which resemble some symptoms of schizophrenia. Recreational use of ketamine has been increasing in recent years. However, little is known of the underlying molecular mechanisms responsible for ketamine-associated psychosis. Recent animal studies have shown that repeated ketamine administration significantly increases NMDA receptor subunit gene expression, in particular subunit 1 (NR1 or GluN1) levels. This results in neurodegeneration, supporting a potential mechanism where up-regulation of NMDA receptors could produce cognitive deficits in chronic ketamine abuse patients. In other studies, NMDA receptor gene variants are associated with addictive behavior. Here, we focus on the roles of NMDA receptor gene subunits in ketamine abuse and ketamine psychosis and propose that full sequencing of NMDA receptor genes may help explain individual vulnerability to ketamine abuse and ketamine-associated psychosis. © 2014 by the Society for Experimental Biology and Medicine.

  20. Hepatic expression of spermatogenic genes and their transiently remarkable downregulations in Wistar-Kyoto rats in response to lead-nitrate administration: strain-difference in the gene expression patterns.

    Science.gov (United States)

    Nemoto, Kiyomitsu; Ito, Sei; Yoshida, Chiaki; Miyata, Misaki; Kojima, Misaki; Degawa, Masakuni

    2011-06-01

    Administration of lead ion (Pb) to rats and mice affects hepatic functions such as the induction of hepatic cell proliferation and upregulation of cholesterol biosynthesis. To identify the genes for which expression changes in response to Pb-administration, we analyzed hepatic gene expression patterns in stroke-prone spontaneously hypertensive rat (SHRSP), its normotensive control, Wistar-Kyoto rat (WKY), and Spraque-Dawley (SD) rat strains, 3, 6, and 12 hr later after single i.v. injection of lead nitrate (LN) at a dose of 100 µmol using a DNA microarray technique. The data analysis demonstrated that the expression of a great number of genes was transiently and remarkably downregulated 3 hr after LN-injection, and then recovered to control levels only in LN-injected WKY. These normal hepatic expression levels in WKY and SHRSP were much higher than those in SD rats. Furthermore, most of these genes were ones thought to be expressed specifically in the spermatids and/or testes; i.e. genes encoding protamin 1, transition protein 1, and transition protein 2. These findings suggest that the regulation system common to expression of all of these genes could be a target site of Pb-toxic action, at least, in the liver of WKY, and that this system might be similar to the system essential for spermatogenesis, especially spermiogenesis, in the testis. In addition, it appears that clarifying the cause of the difference between the systems of WKY and SHRSP might aid in identifying the pathologic genes in SHRSP. Finally, it will be an important to clarify how the products of the genes related to spermatogenesis, including spermiogenesis, are functional in the livers of WKY and SHRSP.

  1. Development of beam diagnostic devices for characterizing electron guns

    International Nuclear Information System (INIS)

    Bhattacharjee, D.; Tiwari, R.; Jayaprakash, D.; Mishra, R.L.; Sarukte, H.; Waghmare, A.; Thakur, N.; Dixit, K.P.

    2015-01-01

    The electron guns for the DC accelerators and RF Linacs are designed and developed at EBC/APPD/BARC, Kharghar. These electron guns need to be characterized for its design and performance. Two test benches were developed for characterizing the electron guns. Various beam diagnostic devices for measuring beam currents and beam sizes were developed. Conical faraday cup, segmented faraday cup, slit scanning bellows movement arrangement, multi-plate beam size measurement setup, multi- wire beam size measurement setup, Aluminum foil puncture assembly etc. were developed and used. The paper presents the in-house development of various beam diagnostics for characterizing electron guns and their use. (author)

  2. Geometry Optimization of DC/RF Photoelectron Gun

    CERN Document Server

    Chen Ping; Yu, David

    2005-01-01

    Pre-acceleration of photoelectrons in a pulsed, high voltage, short, dc gap and its subsequent injection into an rf gun is a promising method to improve electron beam emittance in rf accelerators. Simulation work has been performed in order to optimize the geometric shapes of a dc/rf gun and improve electron beam properties. Variations were made on cathode and anode shapes, dc gap distance, and inlet shape of the rf cavity. Simulations showed that significant improvement on the normalized emittance (< 1 mm-mrad), compared to a dc gun with flat cathode, could be obtained after the geometric shapes of the gun were optimized.

  3. The effect of co-administration of DNA carrying chicken interferon-gamma gene on protection of chickens against infectious bursal disease by DNA-mediated vaccination.

    Science.gov (United States)

    Hsieh, Ming Kun; Wu, Ching Ching; Lin, Tsang Long

    2006-11-17

    The purpose of the present study was to determine whether DNA vaccination by co-administration of DNA coding for chicken interferon-gamma (IFN-gamma) gene and DNA encoding for the VP243 gene of IBDV could enhance immune response and protection efficacy of chickens against challenge by IBDV. Plasmids carrying VP243 gene of IBDV strain variant E (VE) (P/VP243/E) and chicken IFN-gamma gene (P/cIFN-gamma) were constructed, respectively. One-day-old chickens were intramuscularly injected with P/VP243/E, or P/cIFN-gamma, or both once, twice, or three times into the thigh muscle of one leg or the thigh muscles of two separate legs at weekly intervals. Chickens were orally challenged with IBDV strain VE at 3 weeks of age and observed for 10 days. Chickens receiving two plasmids in the same site two times had significantly higher (Pprotection and those receiving two plasmids in the same sites did not have any protection against IBD. The enzyme-linked immunosorbent assay (ELISA) and virus neutralization (VN) titers to IBDV of chickens in the groups with three doses of P/VP243/E were significantly higher (Pprotected by DNA vaccination did not have detectable IBDV antigen in the bursae as determined by immunofluorescent antibody assay (IFA). The results indicated that co-administration of plasmid encoding chicken IFN-gamma gene with plasmid encoding a large segment gene of the IBDV did not enhance immune response and protection against challenge by IBDV.

  4. Gene expression changes induced by ochratoxin A in renal and hepatic tissues of male F344 rat after oral repeated administration

    International Nuclear Information System (INIS)

    Arbillaga, Leire; Vettorazzi, Ariane; Gil, Ana G; Delft, Joost van; Garcia-Jalon, Jose Antonio; Lopez de Cerain, Adela

    2008-01-01

    Ochratoxin A (OTA), a naturally occurring mycotoxin, is nephrotoxic in all animal species tested and is considered a potent renal carcinogen, particularly in male rats. Its mechanism of toxicity is still unknown, although oxidative stress appears to be a plausible mechanism. Therefore, the objective of this study was to identify the biological pathways that are modulated in vivo by OTA in male F344 rats in order to gain further insight into its mechanism of renal toxicity. Rats were gavaged daily with OTA (500 μg/kg bw) and gene expression profiles in target and non-target organs were analyzed after 7 and 21 days administration. As was expected, a time-dependent increase of OTA concentrations was found in plasma, kidney and liver, with the concentrations found in both tissues being quite similar. However, histopathological examinations only revealed changes in kidney; signs of nephrotoxicity involving single cell necrosis and karyomegalic nuclei were observed in the treated rats. The number of differentially expressed genes in kidney was much higher than in liver (541 versus 11 at both time points). Several similarities were observed with other in vivo gene expression data. However, great differences were found with previous in vitro gene expression data, with the exception of DNA damage response which was not observed at mRNA level in any of our study conditions. Down-regulation was the predominant effect. Oxidative stress response pathway and genes involved in metabolism and transport were inhibited at both time points. RGN (regucalcin) - a gene implicated in calcium homeostasis - was strongly inhibited at both time points and genes implicated in cell survival and proliferation were up-regulated at day 21. Moreover, translation factors and annexin genes were up-regulated at both time points. Apart from oxidative stress, alterations of the calcium homeostasis and cytoskeleton structure may be present at the first events of OTA toxicity

  5. Coaxial plasma guns as injectors of high beta linear theta pinches

    International Nuclear Information System (INIS)

    Marshall, J.

    1975-01-01

    A brief review of research on coaxial plasma guns and their use is given. Some problems and possibilities of using this gun for beam injection experiments are pointed out. Some scaling laws for gun energy are described

  6. Brief use of a specific gun in a violent game does not affect attitudes towards that gun

    OpenAIRE

    Hilgard, Joseph; Engelhardt, Christopher R.; Bartholow, Bruce D.

    2016-01-01

    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) ...

  7. Low Emittance Guns for the ILC Polarized Electron Beam

    International Nuclear Information System (INIS)

    Clendenin, J. E.; Brachmann, A.; Ioakeimidi, K.; Kirby, R. E.; Maruyama, T.; Miller, R. H.; Wang, J. W.; Zhou, F.

    2007-01-01

    Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressed by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of ≥200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while ≥500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns

  8. Low Emittance Guns for the ILC Polarized Electron Beam

    International Nuclear Information System (INIS)

    Clendenin, J.E.; Brachmann, A.; Ioakeimidi, K.; Kirby, R.E.; Maruyama, T.; Miller, R.H.; Wang, J.W.; Zhou, F.; SLAC

    2006-01-01

    Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressed by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of (ge)200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while (ge)500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns

  9. Action Alters Object Identification: Wielding a Gun Increases the Bias to See Guns

    Science.gov (United States)

    Witt, Jessica K.; Brockmole, James R.

    2012-01-01

    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…

  10. Perancangan Sistem Kontrol PID Untuk Pengendali Sumbu Elevasi Gun Pada Turret-Gun Kaliber 20 Milimeter

    Directory of Open Access Journals (Sweden)

    Dimas Kunto Ariwibowo

    2017-01-01

    Full Text Available Pertahanan negara pada hakikatnya adalah segala upaya pertahanan yang bersifat semesta yang didasarkan pada kesadaran atas hak dan kewajiban warga negara serta keyakinan pada kekuatan sendiri dengan tujuan untuk menjaga dan melindungi kedaulatan negara, keutuhan wilayah NKRI dan keselamatan segenap bangsa. Salah satu alat pendukung pertahanan yaitu senjata laras panjang, Turret-Gun.  Adapun langkah-langkah yang dilakukan dalam merancang pengendali PID Turret-Gun kaliber 20mm ini diawali dengan studi literatur serta studi lapangan mengenai mekanisme dan parameter-parameter yang terdapat pada Turret-Gun pada sumbu elevasi. Setelah itu dilakukan perancangan transmisi dan sistem kontrol Turret-Gun untuk dievaluasi grafik responnya yang akan digunakan sebagai acuan untuk merancang pengendali PID yang sesuai. Selanjutnya pengendali PID yang telah dirancang lalu disimulasikan, sehingga menghasilkan grafik respon yang sesuai dengan kriteria yang dibutuhkan. Hasil yang telah didapatkan dari penelitian ini adalah konstanta PID yang direkomendasikan untuk , , dan secara berturut-turut adalah sebesar 23061.024, 37820.07 dan 3515.4 yang menghasilkan transient response dengan nilai overshoot sebesar 19.9 % , steady state error sebesar 0 % serta settling time sebesar 0.935 detik. Hasil analisa kestabilan untuk sistem kontrol dengan konstanta PID tersebut menunjukkan bahwa sistem kontrol telah stabil, baik menggunakan metode Root Locus maupun metode Routh-Hurwitz.

  11. Cocaine Administration and Its Withdrawal Enhance the Expression of Genes Encoding Histone-Modifying Enzymes and Histone Acetylation in the Rat Prefrontal Cortex.

    Science.gov (United States)

    Sadakierska-Chudy, Anna; Frankowska, Małgorzata; Jastrzębska, Joanna; Wydra, Karolina; Miszkiel, Joanna; Sanak, Marek; Filip, Małgorzata

    2017-07-01

    Chronic exposure to cocaine, craving, and relapse are attributed to long-lasting changes in gene expression arising through epigenetic and transcriptional mechanisms. Although several brain regions are involved in these processes, the prefrontal cortex seems to play a crucial role not only in motivation and decision-making but also in extinction and seeking behavior. In this study, we applied cocaine self-administration and extinction training procedures in rats with a yoked triad to determine differentially expressed genes in prefrontal cortex. Microarray analysis showed significant upregulation of several genes encoding histone modification enzymes during early extinction training. Subsequent real-time PCR testing of these genes following cocaine self-administration or early (third day) and late (tenth day) extinction revealed elevated levels of their transcripts. Interestingly, we found the enrichment of Brd1 messenger RNA in rats self-administering cocaine that lasted until extinction training during cocaine withdrawal with concomitant increased acetylation of H3K9 and H4K8. However, despite elevated levels of methyl- and demethyltransferase-encoded transcripts, no changes in global di- and tri-methylation of histone H3 at lysine 4, 9, 27, and 79 were observed. Surprisingly, at the end of extinction training (10 days of cocaine withdrawal), most of the analyzed genes in the rats actively and passively administering cocaine returned to the control level. Together, the alterations identified in the rat prefrontal cortex may suggest enhanced chromatin remodeling and transcriptional activity induced by early cocaine abstinence; however, to know whether they are beneficial or not for the extinction of drug-seeking behavior, further in vivo evaluation is required.

  12. Laser-pulsed relativistic electron gun

    International Nuclear Information System (INIS)

    Sherman, N.K.

    1986-01-01

    A relativistic (β ≅ 0.8) electron gun with good emittance and subnanosecond pulse duration which can be synchronized to picosecond laser pulses is being developed at NRC for use in studies of particle acceleration by lasers. Bursts of electron pulses exceeding 280 keV in energy have been extracted into air form a laser-driven vacuum photodiode. Trains of 5 ps pulses of ultraviolet UV light illuminate a magnesium cathode. Photoelectrons emitted from the cathode are accelerated in a graded electrostatic potential set up by a 360 kV Marx-generator. The UV pulses are obtained by doubling the frequency of a 606 nm dye laser modelocked at 160 MHz. Electron energies were measured by residual range in an echelon of Al foils. Total charge per burst was measured by picoammeter. Time structure of the bursts has been examined with plastic scintillator and a fast photomultiplier. Tests on a low voltage photodiode achieved a current density of 180 A/cm/sup 2/ from an Mg cathode, with quantum efficiency of 2.4 x 10/sup -6/ electron per UV photon. The brevity and intensity of the laser pulses cause the electric charge collected per pulse to increase linearly with bias voltage rather than according to the Langmuir-Child law. Gun emittance is about 150 mm-msr and beam brightness is about 1A/cm/sup 2/-sr. Estimated duration of individual electron pulses of a burst is about 400 ps with instantaneous current of about 0.1 mA. Energy spread within one pulse is expected to be about 15%. This gun has the potential to be a useful source of relativistic electrons for laser acceleration studies

  13. Gun buyback programs: a venue to eliminate unwanted guns in the community.

    Science.gov (United States)

    Violano, Pina; Driscoll, Cassandra; Chaudhary, Neil K; Schuster, Kevin M; Davis, Kimberly A; Borer, Esther; Winters, Jane K; Hirsh, Michael P

    2014-09-01

    The United States has a high rate of death due to firearms, and gun buyback programs may mitigate these high death rates. Understanding the demographics, motivation, and geographic region of participants may improve program efficacy. Three Injury Free Coalition for Kids gun buyback programs, in collaboration with the local police, were studied: Phoenix, Arizona; Worcester, Massachusetts; and New Haven, Connecticut. Participants were defined as those who relinquished a firearm. A self-administered, anonymous, paper survey elicited information from participants regarding demographic data, formal training on the use of the firearm, how the firearm was acquired, potential child access, knowledge of others injured by a firearm, whether the firearm was stored unlocked, factors motivating the surrender of the firearm, and other factors. Survey results were entered into a composite database and analyzed for differences in location, race, sex, and other factors. Participants (n = 301) were predominantly male (73.5%), white (80.9%), and older than 55 years (59.0%). They lived an average of 19.0 miles from the event by zip codes and had an average median household income of $65,731. More than half (54.5%) did not purchase the firearm, acquiring it through inheritance, gift, or random find. Most (74.8%) had previous firearms training and were relinquishing for safety reasons (68.3%). Those relinquishing firearms for safety reasons were less likely to have purchased the firearm (odds ratio [OR], 2.46, p gun lock (OR, 0.15; p gun-wielding criminal acts were burglarized from the home of legal gun owners that had failed to secure them properly. The gun buyback program is solely one prong of a multipronged approach in reducing firearm-based interpersonal violence. Additional research is necessary to determine effective methods to target individuals who would have the greatest impact on gun violence if they relinquished their weapons. Through the forging of relationships and

  14. Characterisation of plasma in a rail gun

    Science.gov (United States)

    Ray, P. K.

    1986-01-01

    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.

  15. Gas powered fluid gun with recoil mitigation

    Science.gov (United States)

    Grubelich, Mark C; Yonas, Gerold

    2013-11-12

    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.

  16. Electron gun simulation for 95 GHz gyrotron

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Udaybir; Kumar, Nitin; Sinha, A.K., E-mail: uday.ceeri@gmail.com, E-mail: aksinha@ceeri.ernet.in [Gyrotron Laboratory, Microwave Tube Area, Central Electronics Engineering Research Institute, Pilani (India); Purohit, L.P. [Department of Physics, Gurukul Kangri Vishwavidyalaya, Haridwar (India)

    2011-07-01

    A triode type Magnetron Injection Gun (MIG) for a 2 MW, 95 GHz Gyrotron has been designed by using commercially available code EGUN and another in-house developed code MIGANS. The operating mode of the gyrotron is TE{sub 24.8} and it is operated in the fundamental harmonic. The operating voltages of the modulating anode and the accelerating anode are 61 kV and 85 kV respectively. The parametric dependences of modulating anode voltage and cathode magnetic field on the beam quality have also been studied. (author)

  17. Electron gun simulation for 95 GHz gyrotron

    International Nuclear Information System (INIS)

    Singh, Udaybir; Kumar, Nitin; Sinha, A.K.; Purohit, L.P.

    2011-01-01

    A triode type Magnetron Injection Gun (MIG) for a 2 MW, 95 GHz Gyrotron has been designed by using commercially available code EGUN and another in-house developed code MIGANS. The operating mode of the gyrotron is TE 24.8 and it is operated in the fundamental harmonic. The operating voltages of the modulating anode and the accelerating anode are 61 kV and 85 kV respectively. The parametric dependences of modulating anode voltage and cathode magnetic field on the beam quality have also been studied. (author)

  18. Multiphysics modeling of a rail gun launcher

    Directory of Open Access Journals (Sweden)

    Y W Kwon

    2016-03-01

    Full Text Available A finite element based multiphysics modeling was conducted for a rail gunlauncher to predict the exit velocity of the launch object, and temperaturedistribution. For this modeling, electromagnetic field analysis, heat transferanalysis, thermal stress analysis, and dynamic analysis were conducted fora system consisting of two parallel rails and a moving armature. In particular,an emphasis was given to model the contact interface between rails andthe armature. A contact theory was used to estimate the electric as well asthermal conductivities at the interface. Using the developed model, aparametric study was conducted to understand effects of variousparameters on the exit velocity as well as the temperature distribution in therail gun launcher.

  19. Smart gun technology requirements preliminary report

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-05-01

    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.

  20. Voltage-pulse generator for electron gun

    International Nuclear Information System (INIS)

    Korenev, S.A.; Enchevich, I.B.; Mikhov, M.K.

    1987-01-01

    A voltage-pulse generator with combined capacitive and inductive storage devices of an electron gun is described. The current interrupter is a hydrogen thyratron (TGI1-100/8, TGI1-500/16, or TGI1-1000/25) installed in a short magnetic lens. The current interruption time of the thyratrons is 100-300 nsec. When the capacitive storage device is charged to 1 kV, a voltage pulse with an amplitude of 25 kV is obtained at the load

  1. Magnetic guns with cylindrical permanent magnets

    DEFF Research Database (Denmark)

    Vokoun, David; Beleggia, Marco; Heller, Luděk

    2012-01-01

    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...... of the magnetostatic interaction energy. For comparison, the forces involved are also calculated numerically using finite elements methods. Based on the conservation of the magnetostatic and kinetic energies, the exit and asymptotic velocities are determined. The derived formulas can be used to optimize the generated...... forces and motion of the inner cylindrical magnet....

  2. Electron gun simulation with CST PARTICLE STUDIO

    International Nuclear Information System (INIS)

    Spachmann, Holger; Becker, Ulrich

    2006-01-01

    This paper introduces CST PARTICLE STUDIO TM , a specialist tool for the fast and accurate design and analysis of 3D electron guns. The new software is based on the multi-purpose electromagnetic solvers of the CST STUDIO family and incorporates their powerful modelling capabilities as well as successful algorithms of the MAFIA-TS simulators. The underlying theory of the PBA based field solvers and the used tracking technique is presented and some examples of application demonstrate the current status of the software

  3. Testing a GaAs cathode in SRF gun

    International Nuclear Information System (INIS)

    Wang, E.; Kewisch, J.; Ben-Zvi, I.; Burrill, A.; Rao, T.; Wu, Q.; Holmes, D.

    2011-01-01

    RF electron guns with a strained superlattice GaAs cathode are expected to generate polarized electron beams of higher brightness and lower emittance than do DC guns, due to their higher field gradient at the cathode's surface and lower cathode temperature. We plan to install a bulk GaAs:Cs in a SRF gun to evaluate the performance of both the gun and the cathode in this environment. The status of this project is: In our 1.3 GHz 1/2 cell SRF gun, the vacuum can be maintained at nearly 10 -12 Torr because of cryo-pumping at 2K. With conventional activation of bulk GaAs, we obtained a QE of 10% at 532 nm, with lifetime of more than 3 days in the preparation chamber and have shown that it can survive in transport from the preparation chamber to the gun. The beam line has been assembled and we are exploring the best conditions for baking the cathode under vacuum. We report here the progress of our test of the GaAs cathode in the SRF gun. Future particle accelerators, such as eRHIC and the ILC require high-brightness, high-current polarized electrons. Strained superlattice GaAs:Cs has been shown to be an efficient cathode for producing polarized electrons. Activation of GaAs with Cs,O(F) lowers the electron affinity and makes it energetically possible for all the electrons, excited into the conduction band that drift or diffuse to the emission surface, to escape into the vacuum. Presently, all operating polarized electron sources, such as the CEBAF, are DC guns. In these devices, the excellent ultra-high vacuum extends the lifetime of the cathode. However, the low field gradient on the photocathode's emission surface of the DC guns limits the beam quality. The higher accelerating gradients, possible in the RF guns, generate a far better beam. Until recently, most RF guns operated at room temperature, limiting the vacuum to ∼10 -9 Torr. This destroys the GaAs's NEA surface. The SRF guns combine the excellent vacuum conditions of DC guns and the high accelerating

  4. 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.

  5. Gene expression in distinct regions of rat tendons in response to jump training combined with anabolic androgenic steroid administration

    DEFF Research Database (Denmark)

    Marqueti, Rita Cássia; Marqueti, Rita de Cássia; Heinemeier, Katja Maria

    2012-01-01

    ) submitted to 7 weeks of jumping water load exercise in combination with AAS administration. Wistar male rats were grouped as follows: sedentary (S), trained (jumping water load exercise) (T), sedentary animals treated with AAS (5 mg/kg, twice a week) and animals treated with AAS and trained (AAST). m...

  6. Research and design of electron gun of electrocurtain

    International Nuclear Information System (INIS)

    Chen Pengfei; Zhang Mingchao; Li Xinmin; Wang Yuhong

    1998-01-01

    The characteristics of the electron beam current transport in the electron gun of the electrocurtain accelerator were studied and the origin of the influence on longitudinal uniformity of beam current was analysed. The deflection of the cathode is considered under the boundary condition of perfect constraint. Then a newly designed electron gun is introduced with longitudinal uniformity of current within +-10%

  7. The breakdown phase in a coaxial plasma gun

    International Nuclear Information System (INIS)

    Donges, A.; Herziger, G.; Krompholz, H.; Ruehl, F.; Schoenbach, K.

    1980-01-01

    The electrical breakdown in a coaxial plasma gun was investigated by means of optical and electrical measurements. The optimum start and operation conditions of the gun turned out to be strongly dependent on material and length of the cylindrical insulator. (orig.)

  8. Preventing Clogging In A Vacuum Plasma Spray Gun

    Science.gov (United States)

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

    1994-01-01

    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.

  9. Study and realization of an electron gun at low energy

    International Nuclear Information System (INIS)

    Camus, P.

    1977-01-01

    This work presents the theoretical concepts and experimental design of an electron gun. This gun is working in the weak energy range and the focus position is independant of electron energy measurements and analysis methods of the electron beam are described [fr

  10. The gun control system of the IFUSP microtron

    International Nuclear Information System (INIS)

    Malafronte, A.A.; Takahashi, J.; Bonini, A.L.; Martins, M.N.

    1997-01-01

    A thermionic gun control system has been developed for the IFUSP microtron. The control system, which is composed of a dedicated microcomputer, A/D converter, grid pulser, filament and grid power supplies, is kept at a high voltage potential. The gun parameters are handled through a PC computer at ground potential via fiber-optic link. (orig.)

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

    DEFF Research Database (Denmark)

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

    1991-01-01

    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...

  12. Changing of ballistic parameters from aged gun propellants

    NARCIS (Netherlands)

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

    2003-01-01

    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

  13. Unusual blunt force wound produced by a gun muzzle.

    Science.gov (United States)

    Hanzlick, R; Zaki, S A

    1986-09-01

    Most blunt force injuries produced by guns are associated with gun butts, and patterned, muzzle/sight impressions are usually produced by discharging firearms. An unusual and distinct forehead laceration produced by a blow with the muzzle end of a .32 caliber revolver is presented.

  14. Normative Considerations in the Aftermath of Gun Violence in Schools

    Science.gov (United States)

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

    2015-01-01

    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…

  15. Grip-pattern recognition: Applied to a smart gun

    NARCIS (Netherlands)

    Shang, X.

    2008-01-01

    In our work the verification performance of a biometric recognition system based on grip patterns, as part of a smart gun for use by the police ocers, has been investigated. The biometric features are extracted from a two-dimensional pattern of the pressure, exerted on the grip of a gun by the hand

  16. Everyday Engineering: What Makes a Squirt Gun Squirt?

    Science.gov (United States)

    Moyer, Richard; Everett, Susan

    2009-01-01

    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…

  17. Taking Aim at Gun Violence: Rebuilding Community Education & Employment Pathways

    Science.gov (United States)

    Bryant, Rhonda

    2013-01-01

    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…

  18. Guns and Fear: A One-Way Street?

    Science.gov (United States)

    Hauser, Will; Kleck, Gary

    2013-01-01

    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…

  19. Technological guns which form the profiled electron beans

    International Nuclear Information System (INIS)

    Mel'nik, V.I.

    1998-01-01

    Electron guns with high-voltage glow discharge are developed which form disc - and tubule-like,hollow conic and linear electron beams,as well as devices and systems for control of gun parameter and technological processes in low and intermediate vacuum

  20. Characteristics of typical Pierce guns for PPM focused TWTs

    International Nuclear Information System (INIS)

    Harper, R.; Puri, M.P.

    1989-01-01

    The performance of typical moderate perveance Pierce type electron guns which are used in periodic permanent magnet focused traveling wave tubes are described with regard to adaptation for use in electron beam ion sources. The results of detailed electron trajectory computations for one particular gun design are presented

  1. Emittance growth in laser-driven RF electron guns

    International Nuclear Information System (INIS)

    Kim, K.J.

    1989-01-01

    A simple analysis for the evolution of the electron-beam phase space distribution in laser-driven rf guns is presented. In particular, formulas are derived for the transverse and longitudinal emittances at the exit of the gun. The results are compared and found to agree well with those from simulation. (Author). 9 refs.; 4 figs

  2. Gun Access and Safety Practices among Older Adults

    Directory of Open Access Journals (Sweden)

    Hillary D. Lum

    2016-01-01

    Full Text Available Background. Given high rates of gun ownership among older adults, geriatric providers can assess firearm safety practices using a “5 Ls” approach: Locked; Loaded; Little children; feeling Low; and Learned owner. This study describes gun access and the “5 Ls” among US older adults. Methods. Data on the “5 Ls” from the Second Injury Control and Risk Survey (ICARIS-2, a national telephone survey conducted by the Centers for Disease Control and Prevention, were analyzed. Weighted variables were used to generate national estimates regarding prevalence of gun ownership and associated gun safety among older adults (≥55 years. Results. Of 2939 older adults, 39% (95% CI 37%–42% reported ≥1 gun stored at home. Among those with guns at home, 21% (95% CI 18–24% stored guns loaded and unlocked; 9.2% (95% CI 6.6–12% had ≥1 child in household; 5.1% (95% CI 3.5–6.8% reported past-year suicidal ideation and 3.6% (95% CI 2.1–5.2% reported history of a suicide attempt; and 55% (95% CI 51–59% stated that ≥1 adult had attended firearm safety workshop. Conclusion. Some older adults may be at elevated risk of firearm injury because of storage practices, suicidal thoughts, or limited safety training. Future work should assess effective approaches to reduce the risk of gun-related injuries among older adults.

  3. Gun Possession among Massachusetts Batterer Intervention Program Enrollees

    Science.gov (United States)

    Rothman, Emily F.; Johnson, Renee M.; Hemenway, David

    2006-01-01

    Batterers with access to firearms present a serious lethal threat to their partners. The purpose of this exploratory study is to estimate the prevalence of and risk markers for gun possession among Massachusetts men enrolled in batterer intervention programs. The authors found that 1.8% of the men reported having a gun in or around their home.…

  4. Processing of Niobium-Lined M240 Machine Gun Barrels

    Science.gov (United States)

    2014-11-01

    Fig. 5 Finished niobium-lined M240 machine gun barrel with flash suppressor attached ..........11 Fig. 6 End of barrel 1 showing small amount of...the finished barrel is shown in Fig. 5. 11 Fig. 5 Finished niobium-lined M240 machine gun barrel with flash suppressor attached Firing tests

  5. A 3 GHz photoelectron gun for high beam intensity

    CERN Document Server

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

    1996-01-01

    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...

  6. Utility of indices of gun availability in the community.

    Science.gov (United States)

    Shenassa, Edmond D; Daskalakis, Constantine; Buka, Stephen L

    2006-01-01

    To estimate the degree to which the proportion of homicides and suicides committed with a gun is associated with reported availability of firearms across Chicago neighbourhoods. Data were collected as part of the Project on Human Development in Chicago Neighborhoods (PHDCN), a combined neighbourhood and individual level study of the city of Chicago. The study used data from 837 PHDCN participants between the ages of 17 and 22, residing in 170 different neighbourhoods. Gun availability was measured via participant reports on whether they had carried a gun and whether they perceived gun access to be easy in their community. Data on suicides and homicides were obtained from the Chicago Department of Health. A 10% change in the proportion of homicides committed by a gun in a neighbourhood was associated with a 20% increase in both the odds of reported gun access and reported gun carrying (p=0.002 and 0.048, respectively). The proportion of firearm related suicides was not associated with either of those self reported measures. The proportion of firearm related homicides, but not the proportion of firearm related suicides, is a useful predictor of gun availability across small areas such as neighbourhoods.

  7. ABCG5 gene responses to treadmill running with or without administration of Pistachio atlantica in female rats

    Directory of Open Access Journals (Sweden)

    Abbass Ghanbari-Niaki

    2014-03-01

    Full Text Available   Objective(s: ABC transporters comprise a large family of transmembrane proteins that use the energy provided by ATP hydrolysis to translocate a variety of substrates across biological membranes. All members of the human ABCG subfamily, except for ABCG2, are cholesterol-transporter. The aim of this study was to determine the liver, the small intestine and kidney ABCG5 relative gene expression in response to treadmill-running training in female rats. Materials and Methods: Twenty Wistar rats (6-8 weeks old and 125-135 g weight were used. Animals were randomly assigned to saline-control (SC, saline-training (ST, and Baneh-control (BC, and Baneh-training (BT groups. Training groups did the exercise on a motor-driven treadmill at 25 m/min (0% grade for 60 min/day for eight weeks (5 days/week. Rats were fed orally, with Baneh extraction and saline for six weeks. The two-way ANOVA was employed for statistical analysis.  ABCG5 relative gene expression was detected by Real-time PCR method. Results:The current findings indicate that the Baneh-treated tissues had significantly lower levels of ABCG5 gene expression in the liver, small intestine, and kidneys (P< 0.001, P< 0.003, P< 0.001, respectively, when compared with saline-treated tissues. However, a higher level of gene expression was observed in exercise groups. A lower level of HDL-c but not triglyceride (TG and total cholesterol (TC levels were found in Baneh-treated animals at rest. Conclusion: Exercise training increases ABCG5 relative gene expression in the liver, small intestine and kidney tissues; therefore exercise training may adjust the reduction of ABCG5 relative gene expression in Baneh-training group.

  8. Unsteady flow analysis of combustion processes in a Davis gun

    Energy Technology Data Exchange (ETDEWEB)

    Cho, H.-C.; Shin, H.D. [Korea Advanced Inst. of Science and Technology, Mechanical Engineering Dept., Taejon (Korea, Republic of); Yoon, J.-K. [Hansung Univ., School of Industrial and System Engineering, Seoul (Korea, Republic of)

    1999-09-01

    The Davis gun, a type of recoilless gun, had the advantages of requiring less rear area and less powder than a conventional recoilless gun. The unsteady pressure and flow fields of a Davis gun were numerically simulated by using a two-phase fluid dynamic model. Numerical simulation results were compared with experimental values to evaluate the feasibility of the interior ballistic model. The interior ballistics in a Davis gun with a simple countermass were predicted with the computational model. It was shown that the pressure-time curves matched well between experimental data and numerical analysis except in the vicinity of the peak pressure and steep pressure gradient. The predicted muzzle velocity of projectile and countermass was closely similar to the experimental one. In this study, large pressure waves were not observed since the initial porosity was relatively high ({phi}{sub 0}0.867) and the charge was ignited at the centre of the granular bed. (Author)

  9. Therminoic gun control system for the CEBAF injector

    International Nuclear Information System (INIS)

    Pico, R.; Diamond, B.; Fugitt, J.; Bork, R.

    1989-01-01

    The injector for the CEBAF accelerator must produce a high-quality electron beam to meet the overall accelerator specifications. A Hermosa electron gun with a 2 mm-diameter cathode and a control aperture has been chosen as the electron source. This must be controlled over a wide range of operating conditions to meet the beam specifications and to provide flexibility for accelerator commissioning. The gun is controlled using Computer Automated Measurement and Control (CAMAC IEEE-583) technology. The system employs the CAMAC-based control architecture developed at CEBAF. The control system has been tested, and early operating data on the electron gun and the injector beam transport system has been obtained. This system also allows gun parameters to be stored at the operator location, without paralyzing operation. This paper describes the use of this computer system in the control of the CEBAF electron gun. 2 refs., 6 figs., 1 tab

  10. Particle transport and gas feed during gun injection

    International Nuclear Information System (INIS)

    Fowler, T K.

    1999-01-01

    It is shown that ion and neutral transport during gun injection tends to equalize the density in the spheromak to that in the open-line current channel. Since a gun operating at or near the ion saturation current requires a minimum density, because of transport these gun requirements also determine a minimum density in the spheromak that increases as the field increases. Hence attaining high fields by gun injection sets lower limits on the density, which in turn limits the temperature of the plasma and increases its ohmic resistance. Estimates of these effects are given using 0-D models calibrated to CTX, as guidance to 2-D UEDGE calculations in progress. For gun power levels in SSPX and the Pulsed Spheromak reactor, we find that buildup persists to the highest field levels of interest

  11. An rf modulated electron gun pulser for linacs

    International Nuclear Information System (INIS)

    Legg, R.; Hartline, R.

    1991-01-01

    Present linac injector designs often make use of sub-harmonic prebuncher cavities to properly bunch the electron beam before injection into a buncher and subsequent accelerating cavities. This paper proposes an rf modulated thermionic gun which would allow the sub-harmonic buncher to be eliminated from the injector. The performance parameters for the proposed gun are 120 kV operating voltage, macropulse duration-single pulse mode 2 nsec, multiple pulse mode 100 nsec, rf modularing frequency 500 MHz, charge per micropulse 0.4 nC, macropulse repetition frequency 10 Hz (max). The gun pulser uses a grid modulated planar triode to drive the gun cathode. The grid driver takes advantage of recently developed modular CATV rf drivers, high performance solid state pulser devices, and high-frequency fiber optic transmitters for telecommunications. Design details are presented with associated SPICE runs simulating operation of the gun

  12. High Brightness Injectors Based On Photocathode DC Gun

    International Nuclear Information System (INIS)

    B. Yunn

    2001-01-01

    Sample results of new injector design method based on a photocathode dc gun are presented, based on other work analytically proving the validity of the emittance compensation scheme for the case even when beam bunching is involved. We have designed several new injectors appropriate for different bunch charge ranges accordingly. Excellent beam quality produced by these injectors clearly shows that a photocathode dc gun can compete with a rf gun on an equal footing as the source of an electron beam for the bunch charge ranging up to 2 nano Coulomb (nC). This work therefore elevates a dc gun based injector to the preferred choice for many ongoing high brightness accelerator projects considering the proven operational stability and high average power capability of the dc gun

  13. Extensive neuroadaptive changes in cortical gene-transcript expressions of the glutamate system in response to repeated intermittent MDMA administration in adolescent rats

    Directory of Open Access Journals (Sweden)

    Malki Rana

    2008-04-01

    Full Text Available Abstract Background Many studies have focused on the implication of the serotonin and dopamine systems in neuroadaptive responses to the recreational drug 3,4-methylenedioxy-metamphetamine (MDMA. Less attention has been given to the major excitatory neurotransmitter glutamate known to be implicated in schizophrenia and drug addiction. The aim of the present study was to investigate the effect of repeated intermittent MDMA administration upon gene-transcript expression of the glutamate transporters (EAAT1, EAAT2-1, EAAT2-2, the glutamate receptor subunits of AMPA (GluR1, GluR2, GluR3, the glutamate receptor subunits of NMDA (NR1, NR2A and NR2B, as well as metabotropic glutamate receptors (mGluR1, mGluR2, mGluR3, mGluR5 in six different brain regions. Adolescent male Sprague Dawley rats received MDMA at the doses of 3 × 1 and 3 × 5 mg/kg/day, or 3× vehicle 3 hours apart, every 7th day for 4 weeks. The gene-transcript levels were assessed using real-time PCR validated with a range of housekeeping genes. Results The findings showed pronounced enhancements in gene-transcript expression of GluR2, mGluR1, mGluR5, NR1, NR2A, NR2B, EAAT1, and EAAT2-2 in the cortex at bregma +1.6. In the caudate putamen, mRNA levels of GluR3, NR2A, and NR2B receptor subunits were significantly increased. In contrast, the gene-transcript expression of GluR1 was reduced in the hippocampus. In the hypothalamus, there was a significant increase of GluR1, GluR3, mGluR1, and mGluR3 gene-transcript expressions. Conclusion Repeated intermittent MDMA administration induces neuroadaptive changes in gene-transcript expressions of glutamatergic NMDA and AMPA receptor subunits, metabotropic receptors and transporters in regions of the brain regulating reward-related associative learning, cognition, and memory and neuro-endocrine functions.

  14. Changes in Intestinal Gene Expression of Zebrafish (Danio rerio Related to Sterol Uptake and Excretion upon β-Sitosterol Administration

    Directory of Open Access Journals (Sweden)

    Mai Takase

    2018-01-01

    Full Text Available Replacement of fishmeal with plant ingredients will introduce not only plant oil and protein but also phytosterol to the fish diet. Mammals strictly restrict the uptake of phytosterol at intestinal epithelial cells by regulating the gene expressions of sterol uptake and excretion proteins; however, phytosterol is found in the fish muscle and other organs. In order to assess the ability of phytosterol uptake by the intestinal epithelial cells of fish, no-sterol diet, cholesterol-, and β-sitosterol-containing diet was separately administered to zebrafish, and the relative mRNA expressions related to sterol uptake and excretion were evaluated. Gene expression of Niemann-Pick C1-like protein 1 in the sitosterol-fed group was significantly higher than that of the cholesterol-fed group (p < 0.05. The expression of apolipoprotein A-I gene was also higher in the sitosterol-fed group than that in the no-sterol and cholesterol-fed groups. The expressions of ATP-binding cassette, sub-family G, member 5 and 8, were significantly higher in the sitosterol-fed group, compared to the no-sterol group. Regarding the gene expression of ATP-binding cassette sub-family A, member 1, the sitosterol-fed group showed higher expression level compared to the other groups (p < 0.01. These results suggest that fish should be tolerant to phytosterols in contrast to mammals.

  15. Effect of amiodarone and dronedarone administration in rats on thyroid hormone-dependent gene expression in different cardiac components

    NARCIS (Netherlands)

    Stoykov, I.; van Beeren, H. C.; Moorman, A. F. M.; Christoffels, V. M.; Wiersinga, W. M.; Bakker, O.

    2007-01-01

    OBJECTIVE: In view of their different actions on thyroid hormone receptor (TR) isoforms we set out to investigate whether amiodarone (AM) and dronedarone (Dron) have different and/or component-specific effects on cardiac gene expression. DESIGN: Rats were treated with AM or Dron and the expression

  16. Pigment epithelial-derived factor gene loaded novel COOH-PEG-PLGA-COOH nanoparticles promoted tumor suppression by systemic administration.

    Science.gov (United States)

    Yu, Ting; Xu, Bei; He, Lili; Xia, Shan; Chen, Yan; Zeng, Jun; Liu, Yongmei; Li, Shuangzhi; Tan, Xiaoyue; Ren, Ke; Yao, Shaohua; Song, Xiangrong

    2016-01-01

    Anti-angiogenesis has been proposed as an effective therapeutic strategy for cancer treatment. Pigment epithelium-derived factor (PEDF) is one of the most powerful endogenous anti-angiogenic reagents discovered to date and PEDF gene therapy has been recognized as a promising treatment option for various tumors. There is an urgent need to develop a safe and valid vector for its systemic delivery. Herein, a novel gene delivery system based on the newly synthesized copolymer COOH-PEG-PLGA-COOH (CPPC) was developed in this study, which was probably capable of overcoming the disadvantages of viral vectors and cationic lipids/polymers-based nonviral carriers. PEDF gene loaded CPPC nanoparticles (D-NPs) were fabricated by a modified double-emulsion water-in-oil-in-water (W/O/W) solvent evaporation method. D-NPs with uniform spherical shape had relatively high drug loading (~1.6%), probably because the introduced carboxyl group in poly (D,L-lactide-co-glycolide) terminal enhanced the interaction of copolymer with the PEDF gene complexes. An excellent in vitro antitumor effect was found in both C26 and A549 cells treated by D-NPs, in which PEDF levels were dramatically elevated due to the successful transfection of PEDF gene. D-NPs also showed a strong inhibitory effect on proliferation of human umbilical vein endothelial cells in vitro and inhibited the tumor-induced angiogenesis in vivo by an alginate-encapsulated tumor cell assay. Further in vivo antitumor investigation, carried out in a C26 subcutaneous tumor model by intravenous injection, demonstrated that D-NPs could achieve a significant antitumor activity with sharply reduced microvessel density and significantly promoted tumor cell apoptosis. Additionally, the in vitro hemolysis analysis and in vivo serological and biochemical analysis revealed that D-NPs had no obvious toxicity. All the data indicated that the novel CPPC nanoparticles were ideal vectors for the systemic delivery of PEDF gene and might be widely

  17. Pigment epithelial-derived factor gene loaded novel COOH-PEG-PLGA-COOH nanoparticles promoted tumor suppression by systemic administration

    Directory of Open Access Journals (Sweden)

    Yu T

    2016-02-01

    Full Text Available Ting Yu,1,* Bei Xu,1,* Lili He,2 Shan Xia,3 Yan Chen,1 Jun Zeng,1 Yongmei Liu,1 Shuangzhi Li,1 Xiaoyue Tan,4 Ke Ren,1 Shaohua Yao,1 Xiangrong Song1 1State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, 2College of Chemistry and Environment Protection Engineering, Southwest University for Nationalities, 3Central Laboratory, Science Education Department, Chengdu Normal University, Chengdu, Sichuan, 4Department of Pathology/Collaborative Innovation Center of Biotherapy, Medical School of Nankai University, Tianjin, People’s Republic of China *These authors contributed equally to this work Abstract: Anti-angiogenesis has been proposed as an effective therapeutic strategy for cancer treatment. Pigment epithelium-derived factor (PEDF is one of the most powerful endogenous anti-angiogenic reagents discovered to date and PEDF gene therapy has been recognized as a promising treatment option for various tumors. There is an urgent need to develop a safe and valid vector for its systemic delivery. Herein, a novel gene delivery system based on the newly synthesized copolymer COOH-PEG-PLGA-COOH (CPPC was developed in this study, which was probably capable of overcoming the disadvantages of viral vectors and cationic lipids/polymers-based nonviral carriers. PEDF gene loaded CPPC nanoparticles (D-NPs were fabricated by a modified double-emulsion water-in-oil-in-water (W/O/W solvent evaporation method. D-NPs with uniform spherical shape had relatively high drug loading (~1.6%, probably because the introduced carboxyl group in poly (D,L-lactide-co-glycolide terminal enhanced the interaction of copolymer with the PEDF gene complexes. An excellent in vitro antitumor effect was found in both C26 and A549 cells treated by D-NPs, in which PEDF levels were dramatically elevated due to the successful transfection of PEDF gene. D-NPs also showed a strong inhibitory effect on

  18. Metagenomic Analysis of Antibiotic Resistance Genes in Dairy Cow Feces following Therapeutic Administration of Third Generation Cephalosporin.

    Directory of Open Access Journals (Sweden)

    Lindsey Chambers

    Full Text Available Although dairy manure is widely applied to land, it is relatively understudied compared to other livestock as a potential source of antibiotic resistance genes (ARGs to the environment and ultimately to human pathogens. Ceftiofur, the most widely used antibiotic used in U.S. dairy cows, is a 3rd generation cephalosporin, a critically important class of antibiotics to human health. The objective of this study was to evaluate the effect of typical ceftiofur antibiotic treatment on the prevalence of ARGs in the fecal microbiome of dairy cows using a metagenomics approach. β-lactam ARGs were found to be elevated in feces from Holstein cows administered ceftiofur (n = 3 relative to control cows (n = 3. However, total numbers of ARGs across all classes were not measurably affected by ceftiofur treatment, likely because of dominance of unaffected tetracycline ARGs in the metagenomics libraries. Functional analysis via MG-RAST further revealed that ceftiofur treatment resulted in increases in gene sequences associated with "phages, prophages, transposable elements, and plasmids", suggesting that this treatment also enriched the ability to horizontally transfer ARGs. Additional functional shifts were noted with ceftiofur treatment (e.g., increase in genes associated with stress, chemotaxis, and resistance to toxic compounds; decrease in genes associated with metabolism of aromatic compounds and cell division and cell cycle, along with measureable taxonomic shifts (increase in Bacterioidia and decrease in Actinobacteria. This study demonstrates that ceftiofur has a broad, measureable and immediate effect on the cow fecal metagenome. Given the importance of 3rd generation cephalospirins to human medicine, their continued use in dairy cattle should be carefully considered and waste treatment strategies to slow ARG dissemination from dairy cattle manure should be explored.

  19. Stability and performance studies of the PITZ photoelectron gun

    International Nuclear Information System (INIS)

    Isaev, Igor

    2018-02-01

    The invention of free electron lasers (FELs) opened new opportunities for the investigation of natural phenomena. However, the operation of a FEL requires high energy, high peak current electron beams with very small transverse emittance which causes extreme requirements for the corresponding electron sources. Besides the high beam quality, the electron sources must have very high operational stability and reliability. One of the electron source types which satisfy FEL requirements is a photoelectron gun. Photoelectron guns combine photoemissive electron generation and direct acceleration in a Radio Frequency (RF) cavity. The Photo Injector Test facility at DESY, Zeuthen site (PITZ), was established as a test stand of the electron source for FELs like FLASH and the European XFEL in Hamburg. The studies of the beam emittance at PITZ showed that the gun is able to produce electron beams with emittance even smaller than it is required by XFEL specifications. But the experiments on the emittance revealed discrepancies between expected gun behavior and observation, such as the difference in optimal parameters for the smallest emittance value, asymmetry of the transverse beam profile and the phase spaces. The work performed at PITZ includes preparation of several RF guns for their subsequent operation at FLASH and the European XFEL. RF conditioning of a gun cavity is one of the major steps of the preparation of a high brightness electron source required for modern FELs. A thorough procedure is applied to increase the peak and average RF power in the gun cavity, including an increase of the repetition rate and RF pulse length combined with a gun solenoid current sweep. The main goals of this thesis are: (1) an attempt of deep understanding of physical processes taking place during operation of a photoelectron gun (conditioning process, parameters adjustments); (2) definition of operational problems sources and explanation of the experimentally obtained results in the gun

  20. Stability and performance studies of the PITZ photoelectron gun

    Energy Technology Data Exchange (ETDEWEB)

    Isaev, Igor

    2018-02-15

    The invention of free electron lasers (FELs) opened new opportunities for the investigation of natural phenomena. However, the operation of a FEL requires high energy, high peak current electron beams with very small transverse emittance which causes extreme requirements for the corresponding electron sources. Besides the high beam quality, the electron sources must have very high operational stability and reliability. One of the electron source types which satisfy FEL requirements is a photoelectron gun. Photoelectron guns combine photoemissive electron generation and direct acceleration in a Radio Frequency (RF) cavity. The Photo Injector Test facility at DESY, Zeuthen site (PITZ), was established as a test stand of the electron source for FELs like FLASH and the European XFEL in Hamburg. The studies of the beam emittance at PITZ showed that the gun is able to produce electron beams with emittance even smaller than it is required by XFEL specifications. But the experiments on the emittance revealed discrepancies between expected gun behavior and observation, such as the difference in optimal parameters for the smallest emittance value, asymmetry of the transverse beam profile and the phase spaces. The work performed at PITZ includes preparation of several RF guns for their subsequent operation at FLASH and the European XFEL. RF conditioning of a gun cavity is one of the major steps of the preparation of a high brightness electron source required for modern FELs. A thorough procedure is applied to increase the peak and average RF power in the gun cavity, including an increase of the repetition rate and RF pulse length combined with a gun solenoid current sweep. The main goals of this thesis are: (1) an attempt of deep understanding of physical processes taking place during operation of a photoelectron gun (conditioning process, parameters adjustments); (2) definition of operational problems sources and explanation of the experimentally obtained results in the gun

  1. Gun violence in Americans' social network during their lifetime.

    Science.gov (United States)

    Kalesan, Bindu; Weinberg, Janice; Galea, Sandro

    2016-12-01

    The overall burden of gun violence death and injury in the US is now well understood. However, no study has shown the extent to which gun violence is associated with the individual lives of Americans. We used fatal and non-fatal gun injury rates in 2013 from Centers for Disease Control and Prevention's Web-based Injury Statistics Query and Reporting System (WISQARS) and generally accepted estimates about the size of an American's social network to determine the likelihood that any given person will know someone in their personal social network who is a victim of gun violence during their lifetime. We derived estimates in the overall population and among racial/ethnic groups and by gun-injury intent. The likelihood of knowing a gun violence victim within any given personal network over a lifetime is 99.85% (99.8% to 99.9%). The likelihood among non-Hispanic white, black, Hispanic and other race Americans were 97.1%, 99.9%, 99.5% and 88.9% respectively. Nearly all Americans of all racial/ethnic groups are likely to know a victim of gun violence in their social network during their lifetime. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. The PLX- α Plasma Guns: Progress and Plans

    Science.gov (United States)

    Witherspoon, F. D.; Brockington, S.; Case, A.; Cruz, E.; Luna, M.; Thio, Y. C. Francis; LANL PLX-α Team

    2017-10-01

    The ALPHA coaxial plasma guns are being developed to support a 60-gun scaling study of spherically imploding plasma liners as a standoff driver for plasma-jet-driven magneto-inertial fusion (PJMIF). Seven complete guns have been delivered to LANL with 6 guns currently undergoing simultaneous test firings on PLX. The guns are designed to operate over a range of parameters: 0.5-5.0 mg of Ar, Ne, N2, Kr, and Xe; 20-60 km/s; 2 × 1016 cm-3 muzzle density; and up to 7.5 kJ stored energy per gun. Each coaxial gun incorporates a fast dense gas injection and triggering system, a compact low-weight pfn with integral sparkgap switching, and a contoured coaxial gap to suppress the blow-by instability. Optimizing parameter scans performed at HyperV have achieved : 4 mg at >50 km/s and length of 10 cm. Peak axial density 30 cm from the muzzle is 2 ×1016 cm-3. We will provide an overview of the experimental results, along with plans for further improvements in reliability, maintainability, fabricability, and plasma jet performance, with the latter focused on further improvements in the fast gas valve and the ignitors. This work supported by the ARPA-E ALPHA Program under contract DE-AR0000566 and Strong Atomics, LLC.

  3. TRAIL: a tokamak rail gun limiter

    International Nuclear Information System (INIS)

    Yu, W.S.; Powell, J.R.; Usher, J.L.

    1980-01-01

    An attractive new limiter concept is investigated. The TRAIL (Tokamak Rail Gun Limiter) system impacts a stream of moderate velocity pellets (100 to 200 m/sec through the plasma edge region to absorb energy and define the plasma boundary. The pellets are recycled after cooling, to the injector of an E-M mass accelerator. Heat fluxes of approx. 30,000 W/cm 2 can be readily accommodated by the pellets, with very low recirculating power requirements (approx. 0.1%) for the accelerator. The mass accelerator velocity requirements are well within the present state of the art (several Km/sec). Accelerators injecting pellets at approx. 1 Km/sec can be used to control local plasma temperature and current profiles and to act as energy absorbers to shut down the plasma without damage to the first wall if a plasma disruption occurs

  4. Electrical model of cold atmospheric plasma gun

    Science.gov (United States)

    Slutsker, Ya. Z.; Semenov, V. E.; Krasik, Ya. E.; Ryzhkov, M. A.; Felsteiner, J.; Binenbaum, Y.; Gil, Z.; Shtrichman, R.; Cohen, J. T.

    2017-10-01

    We present an analytical model of cold atmospheric plasma formed by a dielectric barrier discharge (DBD), which is based on the lumped and distributed elements of an equivalent electric circuit of this plasma. This model is applicable for a wide range of frequencies and amplitudes of the applied voltage pulses, no matter whether or not the generated plasma plume interacts with a target. The model allows quantitative estimation of the plasma plume length and the energy delivered to the plasma. Also, the results of this model can be used for the design of DBD guns which efficiently generate cold atmospheric plasma. A comparison of the results of the model with those obtained in experiments shows a fairly good agreement.

  5. Gridded X-ray tube gun

    International Nuclear Information System (INIS)

    1975-01-01

    An X-ray generator has a Pierce type electron gun comprising an electron emissive cathode with field shaping electrodes, a first accelerating anode spaced from the cathode, and an X-ray target anode spaced from the accelerating anode for being impinged upon by a focused electron beam. Control grid means are disposed between the cathode and the first anode. The grid means are constructed such that with use of proper grid potentials, the electron beam may be selectively biased to cutoff, or electrons can be withdrawn from selected areas of the cathode or from the entire cathode to produce focal spots of different sizes and various electron current magnitudes on the target anode

  6. Power conditioner for a coil-gun

    International Nuclear Information System (INIS)

    Zabar, Z.; Joshi, P.N.

    1987-01-01

    This paper describes a power conditioning scheme for introducing currents sequentially into a linear array of coils which form the barrel of a coil-gun. The projectile, a conducting cylindrical sleeve, is driven by the force exerted on it by a traveling magnetic wave-packet created by the barrel currents. Since the rate of energy transfer is proportional to the projectile velocity, it was convenient to divide the barrel into three separate sections. These correspond to the low, medium and high velocity parts of the projectile motion. Each section is excited by a different method, chosen to satisfy the need for most efficient usage of energy stored in the power supply capacitors. Experiments are described with a breadboard model that test the feasibility of the medium-velocity power conditioning scheme

  7. Projectile Balloting Attributable to Gun Tube Curvature

    Directory of Open Access Journals (Sweden)

    Michael M. Chen

    2010-01-01

    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.

  8. Impact fusion with a segmented rail gun

    International Nuclear Information System (INIS)

    Muller, R.A.; Garwin, R.L.; Richter, B.

    1979-01-01

    The basic rail gun equations are reviewed. The delivery of E = 1 megajoule in dt = 10 nanoseconds, with a specific energy of 20 MJ/g (i.e., a bullet mass of 0.05 g) is considered. These values are taken from the requirements being considered for heavy-ion fusion. Using these numbers, we can solve immediately for the final particle velocity u/sub f/ from E = 1/2 mu/sub f/ 2 to get u/sub f/ = 200 km/sec. For a delivery time of 10 nanoseconds, this velocity implies that the projectile length is about 2 mm. Impact fusion is feasible because of the coincidence that a bullet with all dimensions roughly 2 mm has the required mass

  9. Fundamental relativistic solution for the rail gun

    International Nuclear Information System (INIS)

    Liboff, R.L.; Schenter, G.K.

    1986-01-01

    A fully relativistic analysis is made of the dynamics of a rail gun based on three assumptions: (1) Ohm's law is valid in the rest frame of the plasma, (2) total electron momentum is transferred to the projectile, and (3) motion of the projectile is constrained to one direction. With these assumptions, a relativistic equation for the velocity of the projectile is obtained, whose solution monotonically increases to one of two values depending on field strengths. For B>E, the maximum velocity is cE/B, whereas for E>B it is c, where c is the speed of light, and E and B are applied electric and magnetic fields, respectively (in cgs)

  10. Smart Gun Technology project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D.R.

    1996-05-01

    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.

  11. Dynamics of a coaxial plasma gun

    International Nuclear Information System (INIS)

    Raadu, M.A.

    1977-01-01

    The dynamics of an ionizing wave in a coaxial plasma gun with an azimuthal bias magnetic field is analysed in a theoretical model. Only the radial dependence is treated and instead of including a treatment of the energy balance two separate physical assumptions are made. In the first case it is assumed that the total internal electric field is given by the critical ionization velocity condition and in the second that the ionization rate is constant. For consistency wall sheaths are assumed to match the internal plasma potential to that of the walls. On the basis of momentum and particle balance the radial dependence of the electron density, current density, electric field and drift velocity are found. An electron source is required at the cathode and the relative contribution from ionization within the plasma is deduced. The assumption that there are no ion sources at the electrodes leads to a restriction on the possible values of the axial electric field. (Auth.)

  12. Intravenous Administration Is an Effective and Safe Route for Cancer Gene Therapy Using the Bifidobacterium-Mediated Recombinant HSV-1 Thymidine Kinase and Ganciclovir

    Directory of Open Access Journals (Sweden)

    Huicong Zhou

    2016-06-01

    Full Text Available The herpes simplex virus thymidine kinase/ganciclovir (HSV TK/GCV system is one of the best studied cancer suicide gene therapy systems. Our previous study showed that caspase 3 expression was upregulated and bladder tumor growth was significantly reduced in rats treated with a combination of Bifidobacterium (BF and HSV TK/GCV (BF-rTK/GCV. However, it was raised whether the BF-mediated recombinant thymidine kinase combined with ganciclovir (BF-rTK/GCV was safe to administer via venous for cancer gene therapy. To answer this question, the antitumor effects of BF-rTK/GCV were mainly evaluated in a xenograft nude mouse model bearing MKN-45 gastric tumor cells. The immune response, including analysis of cytokine profiles, was analyzed to evaluate the safety of intramuscular and intravenous injection of BF-rTK in BALB/c mice. The results suggested that gastric tumor growth was significantly inhibited in vivo by BF-rTK/GCV. However, the BF-rTK/GCV had no effect on mouse body weight, indicating that the treatment was safe for the host. The results of cytokine profile analysis indicated that intravenous injection of a low dose of BF-rTK resulted in a weaker cytokine response than that obtained with intramuscular injection. Furthermore, immunohistochemical analysis showed that intravenous administration did not affect the expression of immune-associated TLR2 and TLR4. Finally, the BF-rTK/GCV inhibited vascular endothelial growth factor (VEGF expression in mouse model, which is helpful for inhibiting of tumor angiogenesis. That meant intravenous administration of BF-rTK/GCV was an effective and safe way for cancer gene therapy.

  13. Analytical solution for a coaxial plasma gun: Weak coupling limit

    International Nuclear Information System (INIS)

    Dietz, D.

    1987-01-01

    The analytical solution of the system of coupled ODE's which describes the time evolution of an ideal (i.e., zero resistance) coaxial plasma gun operating in the snowplow mode is obtained in the weak coupling limit, i.e, when the gun is fully influenced by the driving (RLC) circuit in which it resides but the circuit is negligibly influenced by the gun. Criteria for the validity of this limit are derived and numerical examples are presented. Although others have obtained approximate, asymptotic and numerical solutions of the equations, the present analytical results seem not to have appeared previously in the literature

  14. Commentary: evidence to guide gun violence prevention in America.

    Science.gov (United States)

    Webster, Daniel W

    2015-03-18

    Gun violence is a major threat to the public's health and safety in the United States. The articles in this volume's symposium on gun violence reveal the scope of the problem and new trends in mortality rates from gunfire. Leading scholars synthesize research evidence that demonstrates the ability of numerous policies and programs-each consistent with lessons learned from successful efforts to combat public health problems-to prevent gun violence. Each approach presents challenges to successful implementation. Future research should inform efforts to assess which approaches are most effective and how to implement evidence-based interventions most effectively.

  15. Note: Characteristic beam parameter for the line electron gun

    Science.gov (United States)

    Iqbal, M.; Islam, G. U.; Zhou, Z.; Chi, Y.

    2013-11-01

    We have optimized the beam parameters of line source electron gun using Stanford Linear Accelerator Centre electron beam trajectory program (EGUN), utilizing electrostatic focusing only. We measured minimum beam diameter as 0.5 mm that corresponds to power density of 68.9 kW/cm2 at 13.5 mm in the post-anode region which is more than two-fold (33 kW/cm2), of the previously reported results. The gun was operated for the validation of the theoretical results and found in good agreement. The gun is now without any magnetic and electrostatic focusing thus much simpler and more powerful.

  16. Note: Characteristic beam parameter for the line electron gun

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, M. [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Islam, G. U. [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Zhou, Z.; Chi, Y. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2013-11-15

    We have optimized the beam parameters of line source electron gun using Stanford Linear Accelerator Centre electron beam trajectory program (EGUN), utilizing electrostatic focusing only. We measured minimum beam diameter as 0.5 mm that corresponds to power density of 68.9 kW/cm{sup 2} at 13.5 mm in the post-anode region which is more than two-fold (33 kW/cm{sup 2}), of the previously reported results. The gun was operated for the validation of the theoretical results and found in good agreement. The gun is now without any magnetic and electrostatic focusing thus much simpler and more powerful.

  17. Note: Characteristic beam parameter for the line electron gun

    International Nuclear Information System (INIS)

    Iqbal, M.; Islam, G. U.; Zhou, Z.; Chi, Y.

    2013-01-01

    We have optimized the beam parameters of line source electron gun using Stanford Linear Accelerator Centre electron beam trajectory program (EGUN), utilizing electrostatic focusing only. We measured minimum beam diameter as 0.5 mm that corresponds to power density of 68.9 kW/cm 2 at 13.5 mm in the post-anode region which is more than two-fold (33 kW/cm 2 ), of the previously reported results. The gun was operated for the validation of the theoretical results and found in good agreement. The gun is now without any magnetic and electrostatic focusing thus much simpler and more powerful

  18. Dynamic Response and Fracture of Composite Gun Tubes

    Directory of Open Access Journals (Sweden)

    Jerome T. Tzeng

    2001-01-01

    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.

  19. Function of bunching segment in multi-cell RF gun

    International Nuclear Information System (INIS)

    Yang Xingfan; Xu Zhou Liu Xisan

    2001-01-01

    With a bunching segment and a shortened first cell, the 4 + 1/2 cell RF gun produced in CAEP has been proved experimentally to be effective in reducing electron back bombardment. The analysis of the electric field distribution and electron motion in bunching segment of multi-cell RF gun is presented. The electron capture efficiency and electron trajectory with different initial phase are calculated using Runge-Kutta method. The function of the bunching segment is discussed. The calculated parameters of the 4 + 1/2 cell RF gun agree well with the experimental results

  20. Note: Characteristic beam parameter for the line electron gun.

    Science.gov (United States)

    Iqbal, M; Islam, G U; Zhou, Z; Chi, Y

    2013-11-01

    We have optimized the beam parameters of line source electron gun using Stanford Linear Accelerator Centre electron beam trajectory program (EGUN), utilizing electrostatic focusing only. We measured minimum beam diameter as 0.5 mm that corresponds to power density of 68.9 kW/cm(2) at 13.5 mm in the post-anode region which is more than two-fold (33 kW/cm(2)), of the previously reported results. The gun was operated for the validation of the theoretical results and found in good agreement. The gun is now without any magnetic and electrostatic focusing thus much simpler and more powerful.

  1. Analysis on a electron gun for metal fusion

    International Nuclear Information System (INIS)

    Paes, A.C.J.; Galvao, R.M.O.; Boscolo, P.; Passaro, A.

    1987-09-01

    The characteristics of the electron beam of the HK-011600 Δ, electron gun for metal fusion at the 'Divisao de Materiais do Instituto de Pesquisa e Desenvolvimento do CTA (PMR/IPD/CTA)', is analyzed. In this analysis, the Pierce gun model and the SLAC computational code for electron optics are used. The electron beam R and Z profiles are obtained in the gun region and in the magnetic lenses region. The behaviour of the electron beam in the prism region is also discussed using a simple model. (author) [pt

  2. Method of electron emission control in RF guns

    International Nuclear Information System (INIS)

    Khodak, I.V.; Kushnir, V.A.

    2001-01-01

    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

  3. Method of electron emission control in RF guns

    CERN Document Server

    Khodak, I V

    2001-01-01

    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.

  4. Design studies on high current and grid control electron gun

    International Nuclear Information System (INIS)

    Wang Jinnan; Lu Kun; Chi Yunlong; Zhou Zusheng

    2011-01-01

    Electron gun, the source of electrons, is a kind of ultrahigh vacuum device and plays an important role in different kind of accelerators. With the irradiation accelerator demands, describes the design studies on beam optics optimization. The simulation result shows that the beam current is above 5 A with cathode voltage of 80 kV and beam emittance, gun electric field and beam waist radius meet the accelerator needs. The electron gun manufactured and installed in the test stand, the conditioning and test will be done in the near future. (authors)

  5. Summary, Working Group 1: Electron guns and injector designs

    International Nuclear Information System (INIS)

    Ben-Zvi, I.; Bazarov, I.V.

    2006-01-01

    We summarize the proceedings of Working Group 1 of the 2005 Energy Recovery Linac (ERL) Workshop. The subject of this working group, the electron gun and injector design, is arguably the most critical part of the ERL as it determines the ultimate performance of this type of accelerators. Working Group 1 dealt with a variety of subjects: The technology of DC, normal-conducting RF and superconducting RF guns; beam dynamics in the gun and injector; the cathode and laser package; modeling and computational issues; magnetized beams and polarization. A short overview of these issues covered in the Working Group is presented in this paper

  6. Brief use of a specific gun in a violent game does not affect attitudes towards that gun.

    Science.gov (United States)

    Hilgard, Joseph; Engelhardt, Christopher R; Bartholow, Bruce D

    2016-11-01

    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.

  7. Brief use of a specific gun in a violent game does not affect attitudes towards that gun

    Science.gov (United States)

    Engelhardt, Christopher R.; Bartholow, Bruce D.

    2016-01-01

    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

  8. In Ovo Administration of Silver Nanoparticles and/or Amino Acids Influence Metabolism and Immune Gene Expression in Chicken Embryos

    Directory of Open Access Journals (Sweden)

    Subrat K. Bhanja

    2015-04-01

    Full Text Available Due to their physicochemical and biological properties, silver nanoparticles (NanoAg have a wide range of applications. In the present study, their roles as a carrier of nutrients and an immunomodulator were tested in chicken embryos. Cysteine (Cys+NanoAg injected embryos had smaller livers but heavier breasts on the 19th day of embryogenesis. Cys injected embryos had lower oxygen consumption compared to threonine (Thr or NanoAg injected embryos. The energy expenditure in Thr+NanoAg, or NanoAg injected embryos was higher than Cys or Cys+NanoAg but was not different from uninjected control embryos. Relative expression of the hepatic insulin-like growth factor-I (IGF-I gene was higher in Cys or NanoAg injected embryos after lipopolysaccharide (LPS induction. The gene expression of hepatic tumour necrosis factor-alpha (TNF-α and interleukin-6 (IL-6 did not differ among amino acids, NanoAg and uninjected controls in the non-LPS groups, but increased by many folds in the LPS treated NanoAg, Cys and Cys+NanoAg groups. In LPS treated spleens, TNF-α expression was also up-regulated by NanoAg, amino acids and their combinations, but interleukin-10 (IL-10 expression was down-regulated in Thr, Cys or Thr+NanoAg injected embryos. Toll like receptor-2 (TLR2 expression did not differ in NanoAg or amino acids injected embryos; however, toll like receptor-4 (TLR4 expression was higher in all treated embryos, except for Cys+NanoAg, than in uninjected control embryos. We concluded that NanoAg either alone or in combination with amino acids did not affect embryonic growth but improved immunocompetence, indicating that NanoAg and amino acid complexes can act as potential agents for the enhancement of innate and adaptive immunity in chicken.

  9. The Effect of Child Access Prevention Laws on Non-Fatal Gun Injuries

    OpenAIRE

    Jeff DeSimone; Sara Markowitz

    2005-01-01

    Many states have passed child access prevention (CAP) laws, which hold the gun owner responsible if a child gains access to a gun that is not securely stored. Previous CAP law research has focused exclusively on gun-related deaths even though most gun injuries are not fatal. We use annual hospital discharge data from 1988-2001 to investigate whether CAP laws decrease non-fatal gun injuries. Results from Poisson regressions that control for various hospital, county and state characteristics, i...

  10. Gene Expression Profiling as a Tool to Investigate the Molecular Machinery Activated during Hippocampal Neurodegeneration Induced by Trimethyltin (TMT Administration

    Directory of Open Access Journals (Sweden)

    Maria Concetta Geloso

    2013-08-01

    Full Text Available Trimethyltin (TMT is an organotin compound exhibiting neurotoxicant effects selectively localized in the limbic system and especially marked in the hippocampus, in both experimental animal models and accidentally exposed humans. TMT administration causes selective neuronal death involving either the granular neurons of the dentate gyrus or the pyramidal cells of the Cornu Ammonis, with a different pattern of localization depending on the different species studied or the dosage schedule. TMT is broadly used to realize experimental models of hippocampal neurodegeneration associated with cognitive impairment and temporal lobe epilepsy, though the molecular mechanisms underlying the associated selective neuronal death are still not conclusively clarified. Experimental evidence indicates that TMT-induced neurodegeneration is a complex event involving different pathogenetic mechanisms, probably acting differently in animal and cell models, which include neuroinflammation, intracellular calcium overload, and oxidative stress. Microarray-based, genome-wide expression analysis has been used to investigate the molecular scenario occurring in the TMT-injured brain in different in vivo and in vitro models, producing an overwhelming amount of data. The aim of this review is to discuss and rationalize the state-of-the-art on TMT-associated genome wide expression profiles in order to identify comparable and reproducible data that may allow focusing on significantly involved pathways.

  11. A numerical study of emittance growths in RF guns

    CERN Document Server

    Masuda, K; Sobajima, M; Kitagaki, J; Ohnishi, M; Toku, H; Yoshikawa, K

    1999-01-01

    A beam with greatly reduced emittance is required for further improvements of FELs, in particular, for FELs of shorter wavelengths, and of narrower bandwidths. From this viewpoint, the BNL/SLAC/UCLA 1.6-cell S-band photocathode RF gun performance characteristics were calculated, first in order to evaluate what may contribute to the emittance growths in photocathode RF guns. We developed an RF gun to produce an electron beam with an extremely low emittance, by using a 2-D simulation code. It is found that, by optimizing the laser injection phase, the drive laser spot radius and the cavity shape around the laser spot, the beam emittance by the 1.6-cell RF gun can be greatly reduced to 2.1 pi mm mrad, from the previous 4.4 pi mm mrad of the original shape.

  12. A NEW THERMIONIC RF ELECTRON GUN FOR SYNCHROTRON LIGHT SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Kutsaev, Sergey; Agustsson, R.; Hartzell, J; Murokh, A.; Nassiri, A.; Savin, E.; Smirnov, A.V.; Smirnov, A. Yu; Sun, Y.; Verma, A; Waldschmidt, Geoff; Zholents, A.

    2017-06-02

    A thermionic RF gun is a compact and efficient source of electrons used in many practical applications. RadiaBeam Systems and the Advanced Photon Source at Argonne National Laboratory collaborate in developing of a reliable and robust thermionic RF gun for synchrotron light sources which would offer substantial improvements over existing thermionic RF guns and allow stable operation with up to 1A of beam peak current at a 100 Hz pulse repetition rate and a 1.5 μs RF pulse length. In this paper, we discuss the electromagnetic and engineering design of the cavity and report the progress towards high power tests of the cathode assembly of the new gun.

  13. Progress on Using NEA Cathodes in an RF Gun

    CERN Document Server

    Fliller, Raymond P; Blüm, Hans; Edwards, Helen; Hüning, Markus; Schultheiss, Tom; Sinclair, Charles K

    2005-01-01

    RF guns have proven useful in multiple accelerator applications, and are an attractive electron source for the ILC. Using a NEA GaAs photocathode in such a gun allows for the production of polarized electron beams. However the lifetime of a NEA cathode in this environment is reduced by ion and electron bombardment and residual gas oxidation. We report progress made with studies to produce a RF gun using a NEA GaAs photocathode to produce polarized electron beams. Attempts to reduce the residual gas pressure in the gun are discussed. Initial measurements of ion flux through the cathode port are compared with simulations of ion bombardment. Future directions are also discussed.

  14. Modeling of the 35-mm Rarefaction Wave Gun

    National Research Council Canada - National Science Library

    Coffee, Terence P

    2006-01-01

    .... The opening of the breech creates a rarefaction wave that travels down the bore of the gun. If the timing is done correctly, the rarefaction wave will not reach the projectile until at or after muzzle exit...

  15. Hartford's gun buy-back program: are we on target?

    Science.gov (United States)

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

    2013-09-01

    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.

  16. Atmospheric pressure DBD gun and its application in ink printability

    International Nuclear Information System (INIS)

    Chen Qiang; Zhang Yuefei; Han Erli; Ge Yuanjing

    2005-01-01

    In this paper, a plasma source discharging at atmospheric pressure and its characterization diagnosed by a Langmuir probe and a digital camera are presented. As an application the dielectric barrier discharge (DBD) gun modifying an ultraviolet cured resin surface for ink printability is reported. The results from the digital camera indicate the uniformity and homogeneity of the plasma generated from the gun in the downstream but depending on the input power, diameter of electrodes, gas flow rates and the distance between the substrates and the nozzle. The contact angle measurement proves the efficiency of gun during the surface modification. The ink printability following DBD gun processing described here was significantly improved. The performed surface analysis using Fourier transform infrared indicates that the polarity of surface grafted in plasma is responsible for the film printability

  17. Finite element analyses for RF photoinjector gun cavities

    International Nuclear Information System (INIS)

    Marhauser, F.

    2006-01-01

    This paper details electromagnetical, thermal and structural 3D Finite Element Analyses (FEA) for normal conducting RF photoinjector gun cavities. The simulation methods are described extensively. Achieved results are presented. (orig.)

  18. Electrostatic focusing of directly heated linear filament gun using EGUN

    International Nuclear Information System (INIS)

    Iqbal, Munawar; Lodhi, M.A.K.; Majeed, Zahid; Batani, Dimitri

    2011-01-01

    This paper presents the optimization of a line source rectangular electron gun using electrostatic focusing. We optimized the gun by shaping the configuration of its electrodes in order to achieve the desired focusing characteristics, namely maximum focusing distance and minimum beam spread. The optimization has been carried out using the software EGUN. We have also simplified the gun design using only one focusing electrode at the same potential as that of the cathode and by avoiding magnetic focusing field, separate focusing electrodes and additional power supply, thus minimizing the cost without any loss in its accuracy and efficient performance. This gun with the optimum configuration was used in actual experiment and the results of the simulation were compared with the experimental measurements.

  19. Finite element analyses of a linear-accelerator electron gun

    Science.gov (United States)

    Iqbal, M.; Wasy, A.; Islam, G. U.; Zhou, Z.

    2014-02-01

    Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.

  20. Electrostatic focusing of directly heated linear filament gun using EGUN

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Munawar, E-mail: muniqbal@yahoo.com [Department of Physics, Texas Tech University, Lubbock, TX 79409 (United States); Lodhi, M.A.K. [Department of Physics, Texas Tech University, Lubbock, TX 79409 (United States); Majeed, Zahid [National Engineering and Science Commission, Islamabad (Pakistan); Batani, Dimitri [Dipartimento di Fisica, Universita degli Studi di Milano Bicocca (Italy)

    2011-06-11

    This paper presents the optimization of a line source rectangular electron gun using electrostatic focusing. We optimized the gun by shaping the configuration of its electrodes in order to achieve the desired focusing characteristics, namely maximum focusing distance and minimum beam spread. The optimization has been carried out using the software EGUN. We have also simplified the gun design using only one focusing electrode at the same potential as that of the cathode and by avoiding magnetic focusing field, separate focusing electrodes and additional power supply, thus minimizing the cost without any loss in its accuracy and efficient performance. This gun with the optimum configuration was used in actual experiment and the results of the simulation were compared with the experimental measurements.

  1. Electrostatic focusing of directly heated linear filament gun using EGUN

    Science.gov (United States)

    Iqbal, Munawar; Lodhi, M. A. K.; Majeed, Zahid; Batani, Dimitri

    2011-06-01

    This paper presents the optimization of a line source rectangular electron gun using electrostatic focusing. We optimized the gun by shaping the configuration of its electrodes in order to achieve the desired focusing characteristics, namely maximum focusing distance and minimum beam spread. The optimization has been carried out using the software EGUN. We have also simplified the gun design using only one focusing electrode at the same potential as that of the cathode and by avoiding magnetic focusing field, separate focusing electrodes and additional power supply, thus minimizing the cost without any loss in its accuracy and efficient performance. This gun with the optimum configuration was used in actual experiment and the results of the simulation were compared with the experimental measurements.

  2. High voltage processing of the SLC polarized electron gun

    International Nuclear Information System (INIS)

    Saez, P.; Clendenin, J.; Garden, C.; Hoyt, E.; Klaisner, L.; Prescott, C.; Schultz, D.; Tang, H.

    1993-04-01

    The SLC polarized electron gun operates at 120 kV with very low dark current to maintain the ultra high vacuum (UHV). This strict requirement protects the extremely sensitive photocathode from contaminants caused by high voltage (HV) activity. Thorough HV processing is thus required x-ray sensitive photographic film, a nanoammeter in series with gun power supply, a radiation meter, a sensitive residual gas analyzer and surface x-ray spectrometry were used to study areas in the gun where HV activity occurred. By reducing the electric field gradients, carefully preparing the HV surfaces and adhering to very strict clean assembly procedures, we found it possible to process the gun so as to reduce both the dark current at operating voltage and the probability of HV discharge. These HV preparation and processing techniques are described

  3. Finite element analyses of a linear-accelerator electron gun

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, M., E-mail: muniqbal.chep@pu.edu.pk, E-mail: muniqbal@ihep.ac.cn [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wasy, A. [Department of Mechanical Engineering, Changwon National University, Changwon 641773 (Korea, Republic of); Islam, G. U. [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Zhou, Z. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2014-02-15

    Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.

  4. Finite element analyses of a linear-accelerator electron gun

    International Nuclear Information System (INIS)

    Iqbal, M.; Wasy, A.; Islam, G. U.; Zhou, Z.

    2014-01-01

    Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator

  5. Design and fabrication of a pulsed diode electron gun

    International Nuclear Information System (INIS)

    Mahadevan, S.; Gandhi, M.L.; Nandedkar, R.V.

    2003-01-01

    A pulsed diode electron gun has been designed, fabricated and tested and this will be used for the initial hot testing of the Plane Wave Transformer (PWT) linac. The gun is required to deliver 1 A at 70 kV which works out to a current of 500 mA at 40 kV. The gun geometry is optimized using the Electron Trajectory Program EGUN at a mesh size of 0.2 mm. The beam divergence close to cathode caused by an annular gap of 2 mm between cathode and focusing electrode (FE) is compensated by using a suitable focusing electrode. Important features of the pulsed power supply (40 kV, 500 mA, 2 μsec) developed for testing this gun are presented. The current measured at the Faraday cup is in agreement with the designed perveance. Suitable positioning of cathode with respect to the FE helps in further improving the beam quality

  6. Performance of the Antares large area cold cathode electron gun

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Mansfield, C.R.

    1983-01-01

    The performance of the electron gun which supplies ionization for the Antares high-power electron-beam-sustained CO 2 -laser power amplifier is described. This electron gun is a coaxial cylindrical cold cathode vacuum triode having a total electron aperture area of approximately 9 m 2 . Electrons are extracted from the gun in pulses of 3 to 6 μs duration, average current densities of 40 to 60 mA/cm 2 , and electron energies of 450 to 500 keV. The main areas of discussion in this paper are the performance in terms of grid control, current-density balance, and current runaway due to breakdown limitations. Comparison of the experimental results with the predictions of a theoretical model for the electron gun are also presented

  7. Performance of the Antares large area cold cathode electron gun

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Mansfield, C.R.

    1983-01-01

    The performance of the electron gun which supplies ionization for the Antares high power electron beam sustained CO 2 laser power amplifier is described. This electron gun is a coaxial cylindrical cold cathode vacuum triode having a total electron aperture area of approximately 9 m 2 . Electrons are extracted from the gun in pulses of 3-6 μs duration, average current densities of 40-60 ma/cm2, and electron energies of 450-500 keV. The main areas of discussion in this paper are the performance in terms of grid control, current density balance, and current runaway due to breakdown limitations. Comparison of the experimental results with the predictions of a theoretical model for the electron gun will also be presented

  8. Mystery of the First Russian Rifle Naval Guns

    Directory of Open Access Journals (Sweden)

    Nicholas W. Mitiukov

    2015-09-01

    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.

  9. Study of an electron gun for metal evaporation

    International Nuclear Information System (INIS)

    Silva, R. da.

    1983-01-01

    In order to design a eletron gun with a long strip beam, an analysis was done using electrostatic lenses. Due the effects of space charge, it was indicated a beam with low current and high energy. (Author) [pt

  10. Finite element analyses for RF photoinjector gun cavities

    Energy Technology Data Exchange (ETDEWEB)

    Marhauser, F. [Berliner Elektronenspeicherring-Gesellschaft fuer Synchrotronstrahlung mbH (BESSY), Berlin (Germany)

    2006-07-01

    This paper details electromagnetical, thermal and structural 3D Finite Element Analyses (FEA) for normal conducting RF photoinjector gun cavities. The simulation methods are described extensively. Achieved results are presented. (orig.)

  11. Spot-Welding Gun With Adjustable Pneumatic Spring

    Science.gov (United States)

    Burley, Richard K.

    1990-01-01

    Proposed spot-welding gun equipped with pneumatic spring, which could be bellows or piston and cylinder, exerts force independent of position along stroke. Applies accurate controlled force to joint welded, without precise positioning at critical position within stroke.

  12. A high current electron gun for the IEAv linac

    International Nuclear Information System (INIS)

    Muraro, A. Jr.; Stopa, C.R.S.; Romao, B.M.V.; Jorge, A.M.; Takahashi, J.

    2001-01-01

    This work presents the design, construction and characterization of a new electron gun for the linear electron accelerator (linac) which is under construction at the Instituto de Estudos Avancados (IEAv)

  13. Can short-term administration of dexamethasone abrogate radiation-induced acute cytokine gene response in lung and modify subsequent molecular responses?

    International Nuclear Information System (INIS)

    Hong, J.-H.; Chiang, C.-S.; Tsao, C.-Y.; Lin, P.-Y.; Wu, C.-J.; McBride, William H.

    2001-01-01

    Purpose: To investigate the effects of short-term administration of dexamethasone (DEX) on radiation-induced responses in the mouse lung, focusing on expression of pro-inflammatory cytokine and related genes. Methods and Materials: At indicated times after thoracic irradiation and/or drug treatment, mRNA expression levels of cytokines (mTNF-α, mIL-1α, mIL-1β, mIL-2, mIL-3, mIL-4, mIL-5, mIL-6, mIFN-γ) and related genes in the lungs of C3H/HeN mice were measured by RNase protection assay. Results: Radiation-induced pro-inflammatory cytokine mRNA expression levels in lung peak at 6 h after thoracic irradiation. DEX (5 mg/kg) suppresses both basal cytokine mRNA levels and this early response when given immediately after irradiation. However, by 24 h, in mice treated with DEX alone or DEX plus radiation, there was a strong rebound effect that lasted up to 3 days. Modification of the early radiation-induced response by DEX did not change the second wave of cytokine gene expression in the lung that occurs at 1 to 2 weeks, suggesting that early cytokine gene induction might not determine subsequent molecular events. A single dose of DEX attenuated, but did not completely suppress, increases in cytokine mRNA levels induced by lipopolysaccharide (2.5 mg/kg) treatment, but, unlike with radiation, no significant rebound effect was seen. Five days of dexamethasone treatment in the pneumonitic phase also inhibited pro-inflammatory cytokine gene expression and, again, there was a rebound effect after withdrawal of the drug. Conclusions: Our findings suggest that short-term use of dexamethasone can temporarily suppress radiation-induced pro-inflammatory cytokine gene expression, but there may be a rebound after drug withdrawal and the drug does little to change the essence and course of the pneumonitic process

  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. A novel carbon gun for use with plasma opening switches

    International Nuclear Information System (INIS)

    Stevenson, P.; Gregory, K.; Cliffe, R.J.; Smith, I.R.

    2001-01-01

    The carbon gun is probably the most common plasma source used in plasma opening switches. Nevertheless, it either produces a contaminated plasma, as the flashover surface erodes, or requires regular treatment with graphite paint. The novel form of the plasma gun described in this paper overcomes the disadvantages of existing designs and produces a cleaner plasma. Experimental results illustrate the performance of a prototype system. (author)

  16. 46th Annual Gun and Missile Systems Conference and Exhibition

    Science.gov (United States)

    2011-09-01

    is concerned (no negative results for environment when dumping of substances is prevented) General Dynamics Ordnance and Tactical Systems...displacement capability of electro dynamic shaker, hydraulic shaker has displacement capability but not force capability  Requested waiver for...support equipment were developed. J75189 Ground Handling Adapter J75192 Hoisting Beam J75199 Gun Transfer Adapter J75196 Mount Rail J75197 Gun Mounting

  17. Plasma gun with coaxial powder feed and adjustable cathode

    Science.gov (United States)

    Zaplatynsky, Isidor (Inventor)

    1991-01-01

    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.

  18. 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)

    2015-11-30

    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).

  19. Contoured-gap coaxial guns for imploding plasma liner experiments

    Science.gov (United States)

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

    2014-10-01

    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.

  20. Engineering design of the PLX- α coaxial gun

    Science.gov (United States)

    Cruz, E.; Brockington, S.; Case, A.; Luna, M.; Witherspoon, F. D.; Thio, Y. C. Francis; PLX-α Team

    2017-10-01

    We describe the engineering and technical improvements, as well as provide a detailed overview of the design choices, of the latest PLX- α 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. The evolution of the latest Alpha gun is presented with emphasis on its upgraded performance. Changes include a faster more robust gas valve, better-quality ceramic insulator material and enhancements to overall design layout. These changes result in a gun with increased repeatability, reduced potential failure modes, improved fault tolerance and better than expected efficiency. A custom 600- μF, 5-kV pfn and a set of six inline sparkgap switches operated in parallel 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. This work supported by the ARPA-E ALPHA Program under contract DE-AR0000566 and Strong Atomics, LLC.

  1. Unusual Case of Suicide With a Modified Trap Gun.

    Science.gov (United States)

    Vadysinghe, Amal; Dassanayake, Prasanna; Wickramasinghe, Medhani

    2017-06-01

    Trap gun is an illegal, locally manufactured gun with a basic trip system used to hunt wild animals. The body of a 28-year-old man was found in the jungle in supine position with both legs apart. A trap gun was between the legs pointing toward the cranial side of the body. It had 2 free wires that were not connected together. There was no evidence of foul play.The body had a single-entry wound (2.5-cm diameter) in the anterior chest, with blackening, burning, and tattooing. Six metal particles and nylon clothing material were embedded into soft tissue. No exit wound was found. Toxicology analysis reported an alcohol level of 72 mg/dL. The cause of death was multiple shrapnel injury to the chest at close to intermediate range by a single discharge from a trap gun. Circumstance was concluded as suicide.Ballistic and firearm experts opined that an illegal, manually operated, battery-powered ignition device was used to ignite the gun powder. We report the first case of suicide by a modified trap gun in literature.

  2. Development of laser heated high current DC electron gun

    International Nuclear Information System (INIS)

    Banerjee, Srutarshi; Bhattacharjee, Dhruva; Kandaswamy, E.; Ghodke, S.R.; Tiwari, Rajnish; Bakhtsingh, R.I.

    2015-01-01

    The paper deals with the development of a Laser heated cathode for Electron Accelerator. The electron gun is meant for Megawatt-class DC Accelerator for Electron Beam Flue Gas Treatment applications. Conventionally, LaB 6 cathode is indirectly heated by tungsten filaments whereas in the newly proposed gun, Laser is utilized for heating. A Nd:YAG Laser is used to heat the LaB 6 cathode to emission temperatures. The characterization of cathode heating at various Laser powers has been carried out. In initial trials, it has been observed that with 125 W of Laser power, the LaB 6 pellet was heated to 1315 ° C. Based on these experimental results, an electron gun rated for 30 kV, 350 mA CW has been designed. The optimization of gun electrode geometry has been done using CST Particle Studio in order to tune the various electron gun parameters. The beam diameter obtained in simulation is 8 mm at 100 mm from the LaB 6 cathode. The perveance obtained is 7.1 x 10 -8 A/V 3/2 . The Laser heated cathode has the advantages of eliminating the magnetic field effects of filament on the electron beam, electrical isolation needed for gun filament power supplies and better electron beam emittances. (author)

  3. A gun recoil system employing a magnetorheological fluid damper

    International Nuclear Information System (INIS)

    Li, Z C; Wang, J

    2012-01-01

    This research aims to design and control a full scale gun recoil buffering system which works under real firing impact loading conditions. A conventional gun recoil absorber is replaced with a controllable magnetorheological (MR) fluid damper. Through dynamic analysis of the gun recoil system, a theoretical model for optimal design and control of the MR fluid damper for impact loadings is derived. The optimal displacement, velocity and optimal design rules are obtained. By applying the optimal design theory to protect against impact loadings, an MR fluid damper for a full scale gun recoil system is designed and manufactured. An experimental study is carried out on a firing test rig which consists of a 30 mm caliber, multi-action automatic gun with an MR damper mounted to the fixed base through a sliding guide. Experimental buffering results under passive control and optimal control are obtained. By comparison, optimal control is better than passive control, because it produces smaller variation in the recoil force while achieving less displacement of the recoil body. The optimal control strategy presented in this paper is open-loop with no feedback system needed. This means that the control process is sensor-free. This is a great benefit for a buffering system under impact loading, especially for a gun recoil system which usually works in a harsh environment. (paper)

  4. Gene

    Data.gov (United States)

    U.S. Department of Health & Human Services — Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes,...

  5. Gene transcripts selectively down-regulated in the shell of the nucleus accumbens long after heroin self-administration are up-regulated in the core independent of response contingency.

    Science.gov (United States)

    Jacobs, Edwin H; de Vries, Taco J; Smit, August B; Schoffelmeer, Anton N M

    2004-01-01

    Long-term drug-induced alterations in neurotransmission within the nucleus accumbens (NAc) shell and core may underlie relapse to drug-seeking behavior and drug-taking upon re-exposure to drugs and drug-associated stimuli (cues) during abstinence. Using an open screening strategy, we recently identified 25 gene transcripts, encoding for proteins involved in neuronal functioning and structure that are down-regulated in rat NAc shell after contingent (active), but not after non-contingent (passive), heroin administration. Studying the expression of the same transcripts in the NAc core by means of quantitative PCR, we now demonstrate that most of these transcripts are up-regulated in that NAc subregion long (3 weeks) after heroin self-administration in rats. A similar up-regulation in gene expression was also apparent in the NAc core of animals with a history of non-contingent heroin administration (yoked controls). These data indicate that heroin self-administration differentially regulates genes in the NAc core as compared with the shell. Moreover, whereas cognitive processes involved in active drug self-administration (e.g., instrumental learning) seems to direct gene expression in the NAc shell, neuroplasticity in the NAc core may be due to the pharmacological effects of heroin (including Pavlovian conditioning), as expressed in rats upon contingent as well as non-contingent administration of heroin.

  6. Simulation of electron beam from two strip electron guns and control of power density by rotation of gun

    International Nuclear Information System (INIS)

    Sahu, G K; Baruah, S; Thakur, K B

    2012-01-01

    Electron beam is preferably used for large scale evaporation of refractory materials. Material evaporation from a long and narrow source providing a well collimated wedge shaped atomic beam has applications in isotopic purification of metals relevant to nuclear industry. The electron beam from an electron gun with strip type filament provides a linear heating source. However, the high power density of the electron beam can lead to turbulence of the melt pool and undesirable splashing of molten metal. For obtaining quiet surface evaporation, the linear electron beam is generally scanned along its length. To further reduce the power density to maintain quiet evaporation the width of the vapour source can be controlled by rotating the electron gun on its plane, thereby scanning an inclined beam over the molten pool. The rotation of gun has further advantages. When multiple strip type electron guns are used for scaling up evaporation length, a dark zone appears between two beams due to physical separation of adjacent guns. This dark zone can be reduced by rotating the gun and thereby bringing two adjacent beams closer. The paper presented here provides the simulation results of the electron beam trajectory and incident power density originating from two strip electron guns by using in-house developed code. The effect of electron gun rotation on the electron beam trajectory and power density is studied. The simulation result is experimentally verified with the image of molten pool and heat affected zone taken after experiment. This technique can be gainfully utilized in controlling the time averaged power density of the electron beam and obtaining quiet evaporation from the metal molten pool.

  7. Differences Between New and Long-Standing US Gun Owners: Results From a National Survey.

    Science.gov (United States)

    Wertz, Joseph; Azrael, Deborah; Hemenway, David; Sorenson, Susan; Miller, Matthew

    2018-07-01

    To quantify the proportion of current US gun owners who are new to owning firearms and compare new versus long-standing gun owners with respect to their firearms and firearm-related behaviors. We performed a cross-sectional analysis of a nationally representative probability-based online survey conducted in 2015 in the United States. We defined new gun owners as current firearm owners who acquired all of their firearms within the past 5 years, but who lived in a home without a gun at some time over the past 5 years. We defined long-standing firearm owners as all other current gun owners. New gun owners represented 10% of all current US adult gun owners. In addition to being younger than long-standing gun owners, new gun owners were more likely to be liberal, own fewer guns, own handguns, own guns only for protection, and store guns in a safe manner. Gun ownership is dynamic, with approximately 1 million Americans becoming new gun owners each year. Public Health Implications. Clinical guidelines should be updated to explicitly endorse re-evaluating household firearm status at regular intervals.

  8. Air pollution: a smoking gun for cancer.

    Science.gov (United States)

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

    2014-04-01

    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, especially in highly populated countries such as China, air pollution 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 will it arrive? What must be done to prevent this possible human catastrophe? Finally, the approaches for air pollution control are also discussed.

  9. Age, Poverty, Homicide, and Gun Homicide

    Directory of Open Access Journals (Sweden)

    Mike Males

    2015-03-01

    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.

  10. Water guns affect abundance and behavior of bigheaded carp and native fish differently

    Science.gov (United States)

    Rivera, Jose; Glover, David C.; Kocovsky, Patrick; Garvey, James E.; Gaikowski, Mark; Jensen, Nathan R.; Adams, Ryan F.

    2017-01-01

    Water guns have shown the potential to repel nuisance aquatic organisms. This study examines the effects of exposure to a 1966.4 cm3 seismic water gun array (two guns) on the abundance and behavior of Bighead Carp Hypophthalmichthys nobilis, Silver Carp H. molitrix (collectively referred to as bigheaded carp) and native fishes (e.g., Smallmouth Buffalo Ictiobus bubalus). Water guns were deployed in a channel that connects the Illinois River to backwater quarry pits that contained a large transient population of bigheaded carp. To evaluate the effect of water guns, mobile side-looking split-beam hydroacoustic surveys were conducted before, during and between replicated water gun firing periods. Water guns did not affect abundance of bigheaded carp, but abundance of native fish detected during the firing treatment was 43 and 34% lower than the control and water guns off treatments, respectively. The proximity of bigheaded carp to the water gun array was similar between the water guns on and water guns off treatments. In contrast, the closest detected native fish were detected farther from the water guns during the water guns on treatment (mean ± SE, 32.38 ± 3.32 m) than during the water guns off treatment (15.04 ± 1.59 m). The water gun array had a greater impact on native fish species than on bigheaded carp. Caution should be taken to the extrapolation of these results to other fish species and to fish exposed to water guns in different environments (e.g., reduced shoreline interaction) or exposure to a larger array of water guns, or for use of water guns for purposes other than a barrier.

  11. Water guns affect abundance and behavior of bigheaded carp and native fish differently

    Science.gov (United States)

    Rivera, Jose; Glover, David C.; Kocovsky, Patrick; Garvey, James E.; Gaikowski, Mark; Jensen, Nathan R.; Adams, Ryan F.

    2018-01-01

    Water guns have shown the potential to repel nuisance aquatic organisms. This study examines the effects of exposure to a 1966.4 cm3 seismic water gun array (two guns) on the abundance and behavior of Bighead Carp Hypophthalmichthys nobilis, Silver Carp H. molitrix (collectively referred to as bigheaded carp) and native fishes (e.g., Smallmouth Buffalo Ictiobus bubalus). Water guns were deployed in a channel that connects the Illinois River to backwater quarry pits that contained a large transient population of bigheaded carp. To evaluate the effect of water guns, mobile side-looking split-beam hydroacoustic surveys were conducted before, during and between replicated water gun firing periods. Water guns did not affect abundance of bigheaded carp, but abundance of native fish detected during the firing treatment was 43 and 34% lower than the control and water guns off treatments, respectively. The proximity of bigheaded carp to the water gun array was similar between the water guns on and water guns off treatments. In contrast, the closest detected native fish were detected farther from the water guns during the water guns on treatment (mean ± SE, 32.38 ± 3.32 m) than during the water guns off treatment (15.04 ± 1.59 m). The water gun array had a greater impact on native fish species than on bigheaded carp. Caution should be taken to the extrapolation of these results to other fish species and to fish exposed to water guns in different environments (e.g., reduced shoreline interaction) or exposure to a larger array of water guns, or for use of water guns for purposes other than a barrier.

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

    International Nuclear Information System (INIS)

    Constantin, Dragoş E.; Fahrig, Rebecca; Holloway, Lois; Keall, Paul J.

    2014-01-01

    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

  13. RF Processing Experience with the GTF Prototype RF Gun

    International Nuclear Information System (INIS)

    Schmerge, J.F.

    2010-01-01

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. A total of five different metal cathodes (4 Cu and 1 Mg) have been installed on the GTF gun. The rf processing history with the different cathodes will be presented including peak field achieved at the cathode. The LCLS gun is intended to operate at 120 MV/m and fields up to 140 MV/m have been achieved in the GTF gun. After installing a new cathode the number of rf pulses required to reach 120 MV/m is approximately 5-10 million. Total emitted dark current and Fowler Nordheim plots are also shown over the life of the cathode. The GTF photo-injector gun is an S-band standing-wave structure, with two resonant cavities and an intervening thick washer (Figure 1). The flat, back wall of the first cavity is a copper plate that serves as photocathode when illuminated with ultraviolet light from a pulsed, high-power laser. RF power enters the gun through an iris on the outer wall of the second cavity, and is coupled to the first through the axial opening of the washer. The first cavity is often referred to as a half cell, because its full-cell length has been truncated by the cathode plate and the second cavity is called the full cell. The gun is designed to operate in a π mode, with the peak field on axis in each cell approximately equal. The maximum in the half cell occurs at the cathode, and in the full cell near the center of the cavity. The field profile and tuning procedures are discussed in a separate tech note (1).

  14. Gun availability and use of guns for suicide, homicide, and murder in Canada.

    Science.gov (United States)

    Bridges, F Stephen; Kunselman, Julie C

    2004-04-01

    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.

  15. Operating characteristics and modeling of the LLNL 100-kV electric gun

    International Nuclear Information System (INIS)

    Osher, J.E.; Barnes, G.; Chau, H.H.; Lee, R.S.; Lee, C.; Speer, R.; Weingart, R.C.

    1989-01-01

    In the electric gun, the explosion of an electrically heated metal foil and the accompanying magnetic forces drive a thin flyer plate up a short barrel. Flyer velocities of up to 18 km/s make the gun useful for hypervelocity impact studies. The authors briefly review the technological evolution of the exploding-metal circuit elements that power the gun, describe the 100-kV electric gun designed at Lawrence Livermore National Laboratory (LLNL) in some detail, and present the general principles of electric gun operation. They compare the experimental performance of the LLNL gun with a simple model and with predictions of a magnetohydrodynamics code

  16. A high voltage test stand for electron gun qualification for LINACs

    International Nuclear Information System (INIS)

    Wanmode, Yashwant D.; Mulchandani, J.; Acharya, M.; Bhisikar, A.; Singh, H.G.; Shrivastava, Purushottam

    2011-01-01

    An electron gun lest stand has been developed at RRCAT. The test stand consists of a high voltage pulsed power supply, electron gun filament supply, grid supply, UHV system and electron gun current measurement system. Several electron guns developed indigenously were evaluated on this test stand. The shielding is provided for the electron gun set up. Electron gun tests can be tested upto 55 kV with pulse width of 15 microsecs and pulse repetition rates up to 200 Hz. The technical details of the subsystems are furnished and results of performance of the test stand have been reported in this paper. (author)

  17. Background Checks for all Gun Buyers and Gun Violence Restraining Orders: State Efforts to Keep Guns from High-Risk Persons.

    Science.gov (United States)

    Vernick, Jon S; Alcorn, Ted; Horwitz, Joshua

    2017-03-01

    There were more than 36,000 firearm-related deaths in the U.S. in 2015. Under federal law, a background check is required only for gun purchases from licensed dealers. Research suggests that some persons prohibited from owning a gun turn to private sellers, including those identified online, to attempt to obtain a firearm. State-level approaches to make it more difficult for high-risk persons to purchase or possess firearms include universal background check (UBC) and gun violence restraining order (GVRO) laws. UBC laws, on the books in 18 states as of the end of 2016, can reduce both homicide and suicide rates. After Colorado adopted a UBC law in 2013, the number of background checks conducted by private sellers for sales occurring at places other than gun shows steadily increased. GVRO laws give law enforcement and families the authority to petition a court to temporarily remove firearms from an individual who presents a danger to himself or others during times of crisis, regardless of whether that person has been diagnosed with a mental illness. California enacted a GVRO law in 2014. Data are emerging to suggest the effectiveness of GVRO-type laws at averting suicides and providing an entryway to services.

  18. Research on Miniature Calibre Rail-Guns for the Mechanical Arm

    Directory of Open Access Journals (Sweden)

    Ronggang Cao

    2017-01-01

    Full Text Available Rail-gun should not only be used to military applications, but also can be developed as applications in the civilian aspects of the market. With the development of the electromagnetic launch technology, based on the similarity theory, using the existing rail-gun model to guide the construction of more economical miniature calibre rail-guns, and apply it in some machinery and equipment, this idea will open up a wider rail-gun application space. This article will focus on the feasibility of application of miniature calibre rail-guns in the mechanical arm. This paper designs the schematic diagram, then theoretical analyzes force conditions of the armature in the mechanical arm, calculates the possible range of the current amplitude and so on. The existing rail-gun model can be used to guides design the circuit diagram of the miniature calibre rail-gun. Based on the similarity theory and many simulation experiments, designed the experimental parameters of a miniature rail-gun and analyzed the current, Lorentz force, velocity, and location of the existing rail-gun and miniature rail-gun. The results show that the rail-gun launching technology applied to robot arms is feasibility. The application of miniature calibre rail-guns in the mechanical arm will benefit to the further development of rail-guns.

  19. Characterization of the C-2W Plasma Guns

    Science.gov (United States)

    Dubois, Ami; Sokolov, Vladimir; Korepanov, Sergey; Osin, Dima; Player, Gabriel; TAE Team

    2017-10-01

    Previous use of coaxial arc discharge plasma guns on the C-2U device exhibited great success in plasma stabilization and improved confinement. On the C-2W experiment, arc discharge plasma guns will again be used to facilitate the electrical connection between the plasma core and the divertor electrodes in order to maintain the electrode edge biasing and induce E x B shear to control plasma rotation. Each plasma gun contains an internal solenoid used to shape the plasma stream. Characterization of electron density (ne) , electron temperature (Te) , floating potential (Vf) , and total plasma flux in an arc discharge lasting 6 ms without the internal solenoid are presented. A Langmuir probe located 27 cm axially outside of the plasma gun anode measures a bell-like radial ne profile with peak ne 1018 m-3 and Te 2 - 10 eV. Observed spectral lines of impurity ions provide an estimate of Te, and Balmer series line ratios of the main ion component are used to evaluate ne at both the probe location and near the plasma gun anode. A calorimeter measures the plasma flux to be constant and equivalent to 1 kA.

  20. Study of the hollow cathode plasma electron-gun

    International Nuclear Information System (INIS)

    Zhang Yonghui; Jiang Jinsheng; Chang Anbi

    2003-01-01

    For developing a novel high-current, long pulse width electron source, the theoretics and mechanism of the hollow cathode plasma electron-gun are analyzed in detail in this paper, the structure and the physical process of hollow cathode plasma electron-gun are also studied. This gun overcomes the limitations of most high-power microwave tubes, which employ either thermionic cathodes that produce low current-density beams because of the limitation of the space charge, or field-emission cathodes that offer high current density but provide only short pulse width because of plasma closure of the accelerating gap. In the theories studying on hollow cathode plasma electron-gun, the characteristic of the hollow-cathode discharge is introduced, the action during the forming of plasma of the stimulating electrode and the modulating anode are discussed, the movement of electrons and ions and the primary parameters are analyzed, and the formulas of the electric field, beam current density and the stabilization conditions of the beam current are also presented in this paper. The numerical simulation is carried out based on Poisson's equation, and the equations of current continuity and movement. And the optimized result is reported. On this basis, we have designed a hollow-cathode-plasma electron-gun, whose output pulse current is 2 kA, and pulse width is 1 microsecond

  1. Momentum equation for arc-driven rail guns

    International Nuclear Information System (INIS)

    Batteh, J.H.

    1984-01-01

    In several models of arc-driven rail guns, the rails are assumed to be infinitely high to simplify the calculation of the electromagnetic fields which appear in the momentum equation for the arc. This assumption leads to overestimates of the arc pressures and accelerations by approximately a factor of 2 for typical rail-gun geometries. In this paper, we develop a simple method for modifying the momentum equation to account for the effect of finite-height rails on the performance of the rail gun and the properties of the arc. The modification is based on an integration of the Lorentz force across the arc cross section at each axial location in the arc. Application of this technique suggests that, for typical rail-gun geometries and moderately long arcs, the momentum equation appropriate for infinite-height rails can be retained provided that the magnetic pressure term in the equation is scaled by a factor which depends on the effective inductance of the gun. The analysis also indicates that the magnetic pressure gradient actually changes sign near the arc/projectile boundary because of the magnetic fields associated with the arc current

  2. rf traveling-wave electron gun for photoinjectors

    Science.gov (United States)

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

    2016-07-01

    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.

  3. rf traveling-wave electron gun for photoinjectors

    Directory of Open Access Journals (Sweden)

    Mattia Schaer

    2016-07-01

    Full Text Available 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.

  4. Effect of doxorubicin, oxaliplatin, and methotrexate administration on the transcriptional activity of BCL-2 family gene members in stomach cancer cells.

    Science.gov (United States)

    Florou, Dimitra; Patsis, Christos; Ardavanis, Alexandros; Scorilas, Andreas

    2013-07-01

    Defective apoptosis comprises the main reason for tumor aggressiveness and chemotherapy tolerance in solid neoplasias. Among the BCL-2 family members, whose mRNA or protein expression varies considerably in different human malignancies, BCL2L12 is the one for which we have recently shown its propitious prognostic value in gastric cancer. The purpose of the current work was to investigate the expression behavior of BCL2L12, BAX, and BCL-2 in human stomach adenocarcinoma cells following their exposure to anti-tumor substances. The 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide and trypan blue methods assessed the impact of doxorubicin, oxaliplatin and methotrexate on AGS cells' viability and growth. Following isolation from cells, total RNA was reverse-transcribed to cDNA. Quantification of target genes' expression was performed with real-time PCR using SYBR Green detection system. The relative changes in their mRNA levels between drug-exposed and untreated cells were calculated with the comparative Ct method (2(-ddCt)). All three drugs, as a result of their administration to AGS cancer cells for particular time intervals, provoked substantial fluctuations in the transcriptional levels of the apoptosis-related genes studied. While BAX was principally upregulated, striking similar were the notable changes regarding BCL-2 and BCL2L12 expression in our cellular system. Our findings indicate the growth suppressive effects of doxorubicin, oxaliplatin and methotrexate treatment on stomach carcinoma cells and the implication of BCL2L12, BAX, and BCL-2 expression profiles in the molecular signaling pathways triggered by chemotherapy.

  5. Thermochemical Erosion Modeling of the 25-MM M242/M791 Gun System

    National Research Council Canada - National Science Library

    Sopok, Samuel

    1997-01-01

    The MACE gun barrel thermochemical erosion modeling code addresses wall degradations due to transformations, chemical reactions, and cracking coupled with pure mechanical erosion for the 25-mm M242/M791 gun system...

  6. Non-channel magnetron gun as the electron source for resonance linear accelerator

    International Nuclear Information System (INIS)

    Ivanov, G.M.; Makhnenko, L.A.; Cherenshchikov, S.A.

    1999-01-01

    Studies on the magnetron gun with a cold cathode being part of linear accelerator on the travelling wave are described. Two modes of the gun operation differing by presence of UHF field of the pre-buncher near the gun are observed. In the mode without UHF field the short (about 2 ns) pulses of accelerated electrons with amplitude up to 0.5 A at the gun current up to 20 A were obtained. The presence of UHF field near the gun makes it possible to obtain the beam of higher duration (up to 1.0 μs), but with current up to 20 mA at the accelerator outlet and up to 1 A at the gun outlet. The mechanism of the gun operation is concerned with the secondary-electron current increase and setting self-sustaining secondary emission. Gun characteristics under study are acceptable for the purposes of injection into accelerator [ru

  7. Numerical design of electron guns and space charge limited transport systems

    International Nuclear Information System (INIS)

    Herrmannsfeldt, W.B.

    1980-10-01

    This paper describes the capabilities and limitations of computer programs used to design electron guns and similarly space-charge limited transport systems. Examples of computer generated plots from several different types of gun problems are included

  8. Strong gun laws are not enough: the need for improved enforcement of secondhand gun transfer laws in Massachusetts.

    Science.gov (United States)

    Braga, Anthony A; Hureau, David M

    2015-10-01

    Research suggests that an overwhelming majority of crime guns were transferred by private sellers before recovery by law enforcement. Unfortunately, most states do not regulate these transactions. This study examines whether analyses of state-level private transfer data could be used to develop interventions to reduce the supply of handguns to violent criminals. Traced Boston crime handguns first sold at Massachusetts license dealers were matched to state secondhand gun transfer data. Logistic regression and descriptive statistics were used to analyze the characteristics of recovered crime guns and in-state primary and secondary market transaction patterns. For crime handguns with records of secondary market transactions in Massachusetts, many rapidly move from private transfer to recovery by the police. Unfortunately, important transaction data on the in-state sources of nearly 63% of recovered handguns were not readily available to law enforcement agencies. Data on private transfers of guns could be used to prevent violent injuries by reducing criminal access. However, the passage of strong private transfer gun laws needs to be accompanied by investments in the vigorous enforcement of reporting requirements. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. US-guided percutaneous biopsies with a biopsy gun

    International Nuclear Information System (INIS)

    Ahn, In Oak; Kim, Hyung Jin; Kim, Jae Hyung; Lee, Goo; Jung, Sung Hoon

    1993-01-01

    Core tissue for histologic study is believed by many pathologist to be more diagnostic than material from needle aspiration. Recently introduced automatched biopsy gun simplifies core biopsies with increased quantity and quality of samples. Authors performed 38 percutaneous biopsies from 38 patients with 18G automated biopsy guns under US guide. Diagnostic target tissues were obtained in 33 biopsies(87%), inadequate tissues in 4(11%), and adequate but not of target tissue in 1(3%). There was no major complication requiring treatment, but pain needing analgesics and pain with nausea/vomiting were experienced in 2 and 1 biopsies respectively. Average number of needle passes was 1.5. We concluded that US guided gun biopsy was a easy and safe way to obtain tissue samples of good quantity and quality, especially useful in hospitals without constant availability of specialist in cytopathology

  10. Cerenkov Radiator Driven by a Superconducting RF Electron Gun

    International Nuclear Information System (INIS)

    Poole, B.R.; Harris, J.R.

    2011-01-01

    The Naval Postgraduate School (NPS), Niowave, Inc., and Boeing have recently demonstrated operation of the first superconducting RF electron gun based on a quarter wave resonator structure. In preliminary tests, this gun has produced 10 ps long bunches with charge in excess of 78 pC, and with beam energy up to 396 keV. Initial testing occurred at Niowave's Lansing, MI facility, but the gun and diagnostic beam line are planned for installation in California in the near future. The design of the diagnostic beam line is conducive to the addition of a Cerenkov radiator without interfering with other beam line operations. Design and simulations of a Cerenkov radiator, consisting of a dielectric lined waveguide will be presented. The dispersion relation for the structure is determined and the beam interaction is studied using numerical simulations. The characteristics of the microwave radiation produced in both the short and long bunch regimes will be presented.

  11. Formation of a compact torus using a toroidal plasma gun

    International Nuclear Information System (INIS)

    Levine, M.A.; Pincosy, P.A.

    1981-01-01

    Myers, Levine and Pincosy earlier reported results using a toroidal plasma gun. The device differs from the usual coaxial plasma gun in the use of a strong toroidal bias current for enhanced efficiency, a pair of disk-like accelerating electrodes for reduced viscosity and a fast pulsed toroidal gas valve for more effective use of the injected gas sample. In addition, a technique is used for generating a toroidal current in the plasma ring. The combination offers an opportunity to deliver a plasma with a large amount of energy and to vary the density and relative toroidal and poloidal magnetic field intensities over a range of values. It is the purpose of this paper to report further experimental results, to project the gun's applications to the formation of a compact torus, and to propose a simple modification of the present apparatus as a test

  12. Streaming metal plasma generation by vacuum arc plasma guns

    International Nuclear Information System (INIS)

    MacGill, R.A.; Dickinson, M.R.; Anders, A.; Monteiro, O.R.; Brown, I.G.

    1998-01-01

    We have developed several different embodiments of repetitively pulsed vacuum arc metal plasma gun, including miniature versions, multicathode versions that can produce up to 18 different metal plasma species between which one can switch, and a compact high-duty cycle well-cooled version, as well as a larger dc gun. Plasma guns of this kind can be incorporated into a vacuum arc ion source for the production of high-energy metal ion beams, or used as a plasma source for thin film formation and for metal plasma immersion ion implantation and deposition. The source can also be viewed as a low-energy metal ion source with ion drift velocity in the range 20 - 200 eV depending on the metal species used. Here we describe the plasma sources that we have developed, the properties of the plasma generated, and summarize their performance and limitations. copyright 1998 American Institute of Physics

  13. Possible application of electromagnetic guns to impact fusion

    Science.gov (United States)

    Kostoff, R. N.; Peaslee, A. T., Jr.; Ribe, F. L.

    1982-01-01

    The possible application of electromagnetic guns to impact fusion for the generation of electric power is discussed, and advantages of impact fusion over the more conventional inertial confinement fusion concepts are examined. It is shown that impact fusion can achieve the necessary high yields, of the order of a few gigajoules, which are difficult to achieve with lasers except at unrealistically high target gains. The rail gun accelerator is well adapted to the delivery of some 10-100 megajoules of energy to the fusion target, and the electrical technology involved is relatively simple: inductive storage or rotating machinery and capacitors. It is concluded that the rail gun has the potential of developing into an impact fusion macroparticle accelerator.

  14. High quality flux control system for electron gun evaporation

    International Nuclear Information System (INIS)

    Appelbloom, A.M.; Hadley, P.; van der Marel, D.; Mooij, J.E.

    1991-01-01

    This paper reports on a high quality flux control system for electron gun evaporation developed and tested for the MBE growth of high temperature superconductors. The system can be applied to any electron gun without altering the electron gun itself. Essential elements of the system are a high bandwidth mass spectrometer, control electronics and a high voltage modulator to sweep the electron beam over the melt at high frequencies. the sweep amplitude of the electron beam is used to control the evaporation flux at high frequencies. The feedback loop of the system has a bandwidth of over 100 Hz, which makes it possible to grow superlattices and layered structures in a fast and precisely controlled manner

  15. Progress of flame gunning materials; Yosha hoshuzai no shinpo

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Kakuichi [Harima Ceramic Corp., Hyogo (Japan)

    1999-04-01

    This report concerns to progress in the thermal spraying for repairing refractory, to say more precisely the flame-gunning materials. Gunning method using wet-slurry materials, in spite of its simplicity in execution, possesses a shortcoming of forming the porous deposit around spraying spot. Contrarily, the flame-gunning method is becoming popular in Japan because this method provides us with the minutely organized deposit having high tenacity and corrosion-resisting property. Flame is made from propane/oxygen mixture to assure the efficient melting of powdered clay. Magnesia/Dromite/slag system is preferable to converter furnace to produce a deposit layer less than 10% porosity. Materials based on alumina are preferable, although giving a relatively elevated porosity, to vacuum degassing vessel, converter furnace of stainless steel, hot stove for blast furnace, etc. Silca-rich system is characterized by the resistivity to recycled thermal procedure which brings about application to coke furnace. (NEDO)

  16. Response of potato to drip and gun irrigation systems

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...

  17. Trapping of gun-injected plasma by a tokamak

    International Nuclear Information System (INIS)

    Leonard, A.W.; Dexter, R.N.; Sprott, J.C.

    1986-10-01

    It is shown that a plasma produced by a Marshall gun can be injected into and trapped by a tokamak plasma. Gun injection raises the line-averaged density and peaks the density profile. Trapping of the gun-injected plasma is explainable in terms of a depolarization current mechanism. A model is developed which describes the slowing of a plasma beam crossing into the magnetic field of a tokamak. The slowing down time is shown to go as tau/sub s/ ∞ n -1 /sub b/T 3 /sub e/(α 0 /L) 2 , where n/sub b/ and T/sub e/ are the density and temperature of the plasma beam and α 0 /L is the pitch of the field lines per unit length in the direction in which the beam is traveling. Experimental tests of this model are consistent with the scaling predictions

  18. Theoretical investigation of an electron gun with a point cathode

    International Nuclear Information System (INIS)

    Rauh, H.; Kern, D.

    1978-01-01

    Electron-optical properties of a gun with a point cathode are determined numerically by tracing a greater number of electron trajectories. In order to calculate the beam current density distribution, an attempt was made to describe the properties of the gun in terms of the parameters describing the inital conditions of the trajectories. Contrary to the conventional electron-optical imaging theory, the electron gun under consideration cannot be sufficiently characterized by a few aberration coefficients, since only a small fraction of the trajectories forming the electron beam would be covered by an expansion containing linear, third and fifth order terms so that the series expansion method is not applicable. (orig.) 891 WBU [de

  19. Longitudinal Jitter Analysis of a Linear Accelerator Electron Gun

    Directory of Open Access Journals (Sweden)

    MingShan Liu

    2016-11-01

    Full Text Available We present measurements and analysis of the longitudinal timing jitter of a Beijing Electron Positron Collider (BEPCII linear accelerator electron gun. We simulated the longitudinal jitter effect of the gun using PARMELA to evaluate beam performance, including: beam profile, average energy, energy spread, and XY emittances. The maximum percentage difference of the beam parameters is calculated to be 100%, 13.27%, 42.24% and 65.01%, 86.81%, respectively. Due to this, the bunching efficiency is reduced to 54%. However, the longitudinal phase difference of the reference particle was 9.89°. The simulation results are in agreement with tests and are helpful to optimize the beam parameters by tuning the trigger timing of the gun during the bunching process.

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

    Science.gov (United States)

    Mahadevan, S.; Gandhi, M. L.; Nandedkar, R. V.

    2003-01-01

    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 μperv and the normalized emittance is within 5 π 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, S. E-mail: maharaja@cat.ernet.in; Gandhi, M.L. E-mail: mlg@cat.ernet.in; Nandedkar, R.V. E-mail: nrv@cat.ernet.in

    2003-01-01

    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.

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

    CERN Document Server

    Mahadevan, S; Nandedkar, R V

    2003-01-01

    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.

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

    International Nuclear Information System (INIS)

    Mahadevan, S.; Gandhi, M.L.; Nandedkar, R.V.

    2003-01-01

    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 μperv and the normalized emittance is within 5π 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

  4. Design of triode electron gun for electron LINAC

    International Nuclear Information System (INIS)

    Prasad, M.; Pande, S.A.; Hannurkar, P.R.

    2003-01-01

    A 10 MeV, 10 kW, electron linear accelerator is being developed at Centre for Advanced Technology, CAT for irradiation of agricultural products such as onions and potatoes. This facility required electron beam of variable energy and power. The linac structure consists of a thermionic triode gun, TW buncher and accelerator waveguide, focusing and centering coils, beam scanning system etc. The accelerator structure is disk loaded waveguide operating in TW 27π/3 mode at 2856 MHz. The triode gun is designed for operation at 50 kV. The gun is optimized for minimum grid voltage and minimum transverse beam dimensions. In this paper, the results of our optimization studies using computer code EGUN are presented. (author)

  5. Upgraded G-optk program for electron gun characterization

    International Nuclear Information System (INIS)

    Nagasao, K.; Takebe, M.; Ushio, W.; Fujita, S.; Ohye, T.; Shimoyama, H.

    2011-01-01

    The generalized trajectory theory (the G-optk program) has been extended in order to make the method applicable to electron guns with curved and/or asymmetric cathodes. The object-image analysis mode has also been added. Enhanced capability of the upgraded G-optk program was demonstrated by applying the program to three electron optical systems: (a) the point cathode gun, (b) the hairpin-type cathode gun, and (c) the LEEM objective lens. The Canonical Mapping Transformation (CMT) diagrams were calculated both by direct ray tracing and by the upgraded G-optk program. In each case, it was found that the upgraded program reproduces well the results obtained by ray tracing. The generalized trajectory method has several advantages over direct ray tracing, such as substantially lighter calculation load and easy interpretation of the calculation results in terms of the optical parameters.

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

    International Nuclear Information System (INIS)

    Jay L. Hirshfield

    2005-01-01

    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

  7. Results from operation of metal melting electron gun

    International Nuclear Information System (INIS)

    Balloni, A.J.; Paes, A.C.J.; Miliano, A.C.

    1988-09-01

    The first results obtained during the operation of metal melting electron gun, of power 30Kw and current 1,2A, developed at IEAv, are presented. Details on operation of beam transport system (composed by magnetic lens and prism), from generation to fusion chamber and cathode construction. Into the fusion chamber the presssure can reach 10 -4 Pa, seeing that the gun test consisted in fusion for purification of approximatelly 1Kg titanium bar. The input average power was 12Kw, and the fusion remainded during 16 minutes. The calculated thermal efficiency was of the order of 10% consistent with the results found out in literature, for this type of gun. (M.C.K.) [pt

  8. A design study of non-adiabatic electron guns

    International Nuclear Information System (INIS)

    Barroso, J.J.; Stellati, C.

    1994-01-01

    The design of a non-adiabatic gun capable of producing a 10 A, 50 KeV high-quality laminar electron beam is reported. In contrast to the magnetron injection gun with a conical cathode, where the beam is generated initially with a transverse velocity component, in the non-adiabatic gun electrons are extracted in a direction parallel to the axial guide magnetic field. The beam electrons acquire cyclotron motion as result of non-adiabatic processes in a strong non uniform electric field across the modulation anode. Such an extraction method gives rise to favourable features that are explored throughout the work. An extensive numerical simulation study has also been done to minimize velocity and energy spreads. (author). 3 refs, 5 figs, 1 tab

  9. Emittance compensation of CW DC-gun photoinjector

    International Nuclear Information System (INIS)

    Li Peng; Wu Dai; Xu Zhou; Li Ming; Yang Xingfan

    2011-01-01

    Emittance growth induced by space charge effect is very important, especially for CW DC-gun photoinjector. In this work, the linear space charge force and its effect on electron beam transverse emittance are studied, and the principle and properties of emittance compensation by solenoid are analyzed. The CAEP DC-gun photoinjector with a solenoid is also simulated by code Parmela. Simulated results indicate that the normalized transverse emittance of an 80 pC bunch at the 350 keV DC-gun ex-it is 5.14 mm · mrad. And after compensated by a solenoid, it becomes 1.27 mm · mrad. The emittance of beam is well compensated. (authors)

  10. The challenge of gun control for mental health advocates.

    Science.gov (United States)

    Pandya, Anand

    2013-09-01

    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.

  11. Design and remote fiber communication of NSRL electron gun controller

    International Nuclear Information System (INIS)

    Wang Weibing; Gao Hui; Hong Jun; Chen Jun; Wang Guicheng; He Duohui; Chen Gang

    2005-01-01

    A new kind of pulse electron gun controller for 200 MeV LINAC at National Synchrotron Radiation Laboratory was introduced in this paper, including the working principle of the pulse electron gun, the applications of I 2 C serial bus and embedded microcontroller in controlling system. The emphasis is on the hardware design of digital controlled current regulator, digital controlled switch voltage source and high voltage pulse power supply. The software design of fiber communication and PC controlling is also presented. The electron gun controller has successfully been used in NSRL. The result shows that it is quite reliable and the performance is good. This electronic digital system has completely replaced the old mechanical control system. (authors)

  12. Supply system with microprocessor control for electron gun

    International Nuclear Information System (INIS)

    Duplin, N.I.; Sergeev, N.N.

    1988-01-01

    Precision supply system for electron gun used in Auger-spectrometer is described. The supply system consists of control and high-voltage parts, made as separate units. Supply high-voltage unit includes system supply module, filament module to supply electron gun cathode and 6 high-volt modules to supply accelerating, modulating and three focusing electrodes of the gun. High-voltage modules have the following characteristics: U-(100-1000)V output voltage, 5x10 -5 U stability, 10 -5 xU pulsation amplitude, J-(0-5)A filament current change range at 10 -4 xJ stability. Control unit including microprocessor, timer and storage devices forms control voltage for all modules and regulates voltage and current of filament at electrodes

  13. Characterization of a dielectric barrier plasma gun discharging at atmospheric pressure

    International Nuclear Information System (INIS)

    Zhang Guangqiu; Ge Yuanjing; Zhang Yuefei; Chen Guangliang

    2004-01-01

    The authors 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, authors find that the gun can be used as a source to generate a stable uniform plasma for different plasma-processing technologies. (author)

  14. Armed To Learn: Aiming At California K 12 School Gun Policy

    Science.gov (United States)

    2016-03-01

    AIMING AT CALIFORNIA K-12 SCHOOL GUN POLICY by Catherine Wilson Jones March 2016 Thesis Co-Advisors: Kathleen Kiernan John Rollins...Master’s thesis 4. TITLE AND SUBTITLE ARMED TO LEARN: AIMING AT CALIFORNIA K-12 SCHOOL GUN POLICY 5. FUNDING NUMBERS 6. AUTHOR(S) Catherine...gap in viewpoints between gun control advocates who want tighter gun control and constitutionalists who believe as strongly in the Second Amendment

  15. Low power microwave tests on RF gun prototype of the Iranian Light Source Facility

    Directory of Open Access Journals (Sweden)

    A Sadeghipanah

    2017-08-01

    Full Text Available In this paper, we introduce RF electron gun of Iranian Light Source Facility (ILSF pre-injection system. Design, fabrication and low-power microwave tests results of the prototype RF electron gun have been described in detail. This paper also explains the tuning procedure of the prototype RF electron gun to the desired resonant frequency. The outcomes of this project brighten the path to the fabrication of the RF electron gun by the local industries  

  16. Plasma-filled diode based on the coaxial gun

    Science.gov (United States)

    Zherlitsyn, A. A.; Kovalchuk, B. M.; Pedin, N. N.

    2012-10-01

    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.

  17. Plasma-filled diode based on the coaxial gun.

    Science.gov (United States)

    Zherlitsyn, A A; Kovalchuk, B M; Pedin, N N

    2012-10-01

    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.

  18. Electric gun: a new tool for ultrahigh-pressure research

    International Nuclear Information System (INIS)

    Weingart, R.C.; Chau, H.H.; Goosman, D.R.; Hofer, W.W.; Honodel, C.A.; Lee, R.S.; Steinberg, D.J.; Stroud, J.R.

    1979-01-01

    We have developed a new tool for ultrahigh-pressure research at LLL. This system, which we call the electric gun, has already achieved thin flyer plate velocities in excess of 20 km/s and pressures of the order of 2 TPa in tantalum. We believe that the electric gun is competitive with laser- and nuclear-driven methods of producing shocks in the 1-to-5 TPa range because of its precision and ease and economy of operation. Its development is recommended for shock initiation studies, dry runs for Site 300 hydroshots, and as a shock wave generator for surface studies

  19. Surface Characterization of the LCLS RF Gun Cathode

    International Nuclear Information System (INIS)

    Brachmann, Axel; Decker, Franz-Josef; Ding, Yuantao; Dowell, David; Emma, Paul; Frisch, Josef; Gilevich, Sasha; Hays, Gregory; Hering, Philippe; Huang, Zhirong; Iverson, Richard; Loos, Henrik; Miahnahri, Alan; Nordlund, Dennis; Nuhn, Heinz-Dieter; Pianetta, Piero; Turner, James; Welch, James; White, William; Wu, Juhao; Xiang, Dao

    2012-01-01

    The first copper cathode installed in the LCLS RF gun was used during LCLS commissioning for more than a year. However, after high charge operation (> 500 pC), the cathode showed a decline of quantum efficiency within the area of drive laser illumination. They report results of SEM, XPS and XAS studies that were carried out on this cathode after it was removed from the gun. X-ray absorption and X-ray photoelectron spectroscopy reveal surface contamination by various hydrocarbon compounds. In addition they report on the performance of the second installed cathode with emphasis on the spatial distribution of electron emission.

  20. The system of RF beam control for electron gun

    International Nuclear Information System (INIS)

    Barnyakov, A.M.; Levichev, A.E.; Chernousov, Yu.D.; Ivannikov, V.I.; Shebolaev, I.V.

    2015-01-01

    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

  1. 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)

    2012-10-15

    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.

  2. Plasma wave observations during electron and ion gun experiments

    International Nuclear Information System (INIS)

    Olsen, R.C.; Lowery, D.R.; Weddle, L.E.

    1988-01-01

    Plasma wave instruments with high temporal and frequency resolution in the 0-6 kHz frequency range have been used to monitor electron gun-employing charge control experiments with the USAF/NASA p78-2 satellite, in order to determine whether plasma wave signatures consistent with the previous inference of electron heating were present. Strong plasma waves were noted near the electron gyrofrequency; these waves can heat ambient low energy electrons, as previously inferred. Attention is given to the two distinct classes of behavior revealed by the ion gun experiments. 16 references

  3. Plasma-filled diode based on the coaxial gun

    International Nuclear Information System (INIS)

    Zherlitsyn, A. A.; Kovalchuk, B. M.; Pedin, N. N.

    2012-01-01

    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.

  4. Gun laws and the involuntarily committed: a California road map.

    Science.gov (United States)

    Zahedi, Sohrab; Burchuk, Robert; Stone, David C; Kopelowicz, Alex

    2009-01-01

    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.

  5. Firearm violence and the effects of gun control legislation.

    Science.gov (United States)

    Jung, R S; Jason, L A

    1988-08-01

    Two gun control laws designed to reduce different types of violent crimes were evaluated. In 1981, East St. Louis, IL, imposed stricter penalties for individuals who carry firearms outside their homes for protection (individuals could keep firearms in their homes). This law had only a temporary impact in reducing firearm use in assaults and robberies. In Evanston, IL, a slightly different approach was taken with legislation that banned handguns in the entire city (i.e., individuals could not keep handguns within their homes). A temporary reduction in firearm assaults occurred a few months before the gun law took effect. The implications of these findings are discussed.

  6. A cusp electron gun for millimeter wave gyrodevices

    Science.gov (United States)

    Donaldson, C. R.; He, W.; Cross, A. W.; Li, F.; Phelps, A. D. R.; Zhang, L.; Ronald, K.; Robertson, C. W.; Whyte, C. G.; Young, A. R.

    2010-04-01

    The experimental results of a thermionic cusp electron gun, to drive millimeter and submillimeter wave harmonic gyrodevices, are reported in this paper. Using a "smooth" magnetic field reversal formed by two coils this gun generated an annular-shaped, axis-encircling electron beam with 1.5 A current, and an adjustable velocity ratio α of up to 1.56 at a beam voltage of 40 kV. The beam cross-sectional shape and transported beam current were measured by a witness plate technique and Faraday cup, respectively. These measured results were found to be in excellent agreement with the simulated results using the three-dimensional code MAGIC.

  7. High-voltage pulse generator for electron gun power supply

    International Nuclear Information System (INIS)

    Korenev, S.A.; Enchevich, I.B.; Mikhov, M.K.

    1987-01-01

    High-voltage pulse generator with combined capacitive and inductive energy storages for electron gun power supply is described. Hydrogen thyratron set in a short magnetic lense is a current breaker. Times of current interruption in thyratrons are in the range from 100 to 300 ns. With 1 kV charging voltage of capacitive energy storage 25 kV voltage pulse is obtained in the load. The given high-voltage pulse generator was used for supply of an electron gun generating 10-30 keV low-energy electron beam

  8. Beta II plasma-gun mechanical design and construction

    International Nuclear Information System (INIS)

    Pedrotti, L.; Deis, G.; Wong, R.; Calderon, M.; Chargin, A.; Garner, D.

    1979-01-01

    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

  9. Revisiting the Gun Ownership and Violence Link; a multi- level analysis of victimisation survey data.

    NARCIS (Netherlands)

    van Kesteren, J.N.

    2014-01-01

    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

  10. Individual-Level Risk Factors for Gun Victimization in a Sample of Probationers

    Science.gov (United States)

    Wells, William; Chermak, Steven

    2011-01-01

    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…

  11. Gun policy and serious mental illness: priorities for future research and policy.

    Science.gov (United States)

    McGinty, Emma Elizabeth; Webster, Daniel W; Barry, Colleen L

    2014-01-01

    In response to recent mass shootings, policy makers have proposed multiple policies to prevent persons with serious mental illness from having guns. The political debate about these proposals is often uninformed by research. To address this gap, this review article summarizes the research related to gun restriction policies that focus on serious mental illness. Gun restriction policies were identified by researching the THOMAS legislative database, state legislative databases, prior review articles, and the news media. PubMed, PsycINFO, and Web of Science databases were searched for publications between 1970 and 2013 that addressed the relationship between serious mental illness and violence, the effectiveness of gun policies focused on serious mental illness, the potential for such policies to exacerbate negative public attitudes, and the potential for gun restriction policies to deter mental health treatment seeking. Limited research suggests that federal law restricting gun possession by persons with serious mental illness may prevent gun violence from this population. Promotion of policies to prevent persons with serious mental illness from having guns does not seem to exacerbate negative public attitudes toward this group. Little is known about how restricting gun possession among persons with serious mental illness affects suicide risk or mental health treatment seeking. Future studies should examine how gun restriction policies for serious mental illness affect suicide, how such policies are implemented by states, how persons with serious mental illness perceive policies that restrict their possession of guns, and how gun restriction policies influence mental health treatment seeking among persons with serious mental illness.

  12. Is it a dangerous world out there? The motivational bases of American gun ownership

    NARCIS (Netherlands)

    Stroebe, Wolfgang; Leander, N. Pontus; Kruglanski, Arie W.

    2017-01-01

    Americans are the world’s best armed citizens and public polling suggests protection/self-defense is their main reason for gun ownership. However, there is virtually no psychological research on gun ownership. The present article develops the first psychological process model of defensive gun

  13. The structural design and the electron optics of a hybrid electron-ion gun

    International Nuclear Information System (INIS)

    Bas, E.B.; Gisler, E.; Stucki, F.

    1984-01-01

    This paper describes a new kind of a particle gun called the hybrid gun. It is able to deliver a finely focused electron or ion beam simply by reversing the polarity of the acceleration voltage. The detailed design features of the gun are given and the electron-ion optical properties are discussed. (author)

  14. Crime, Culture Conflict, and the Sources of Support for Gun Control.

    Science.gov (United States)

    Kleck, Gary

    1996-01-01

    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)

  15. To Keep and Bear Arms: Gun Control and the Second Amendment. Teacher's Guide.

    Science.gov (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…

  16. Development of an electron gun for high power CW electron linac (1). Beam experiment for basic performance of electron gun

    International Nuclear Information System (INIS)

    Yamazaki, Yoshio; Nomura, Masahiro; Komata, Tomoki

    1999-05-01

    Presently, the Beam Group of Oarai Engineering Center in Japan Nuclear Cycle Development Institute (JNC) completed the high power CW electron linac. Then we started full-scale beam experiments after the government permission for a radiation equipment had given last January. Measurements of basic performance for the mesh-grid type electron gun have been done to launch stable beam at 300 mA peak current downstream of the accelerator. These experiments disclosed to increase beam loss in the electron gun in some cases of voltage supplied the mesh-grid in spite of same beam current from gun. Consequently, we could find the best condition for mesh-grid voltage and heater current to supply stable beam at 300 mA peak current for accelerator study. (author)

  17. Design of a high repetition rate S-band photocathode gun

    International Nuclear Information System (INIS)

    Han Janghui; Cox, Matthew; Huang, Houcheng; Pande, Shivaji

    2011-01-01

    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. - Highlights: → We design an S-band gun for low emittance beam generation and high repetition rate operation. → The RF design and thermal analysis of the gun cavity and coupler are studied. → An FEL injector 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.

  18. X-Band Thermionic Cathode RF Gun at UTNL

    CERN Document Server

    Fukasawa, Atsushi; Dobashi, Katsuhiro; Ebina, Futaro; Hayano, Hitoshi; Higo, Toshiyasu; Kaneyasu, Tatsuo; Matsuo, Kennichi; Ogino, Haruyuki; Sakae, Hisaharu; Sakamoto, Fumito; Uesaka, Mitsuru; Urakawa, Junji

    2005-01-01

    The X-band (11.424 GHz) linac for compact Compton scattering hard X-ray source are under construction at Nuclear Engineering Research Laboratory, University of Tokyo. This linac designed to accelerate up to 35 MeV, and this electron beam will be used to produce hard X-ray by colliding with laser. It consists of a thermionic cathode RF gun, an alpha magnet, and a traveling wave tube. The gun has 3.5 cells (unloaded Q is 8250) and will be operated at pi-mode. A dispenser cathode is introduced. Since the energy spread of the beam from the gun is predicted to be broad due to the continuous emission from the thermionic cathode, a slit is placed in the alpha magnet to eliminate low energy electrons. The simulation on the injector shows the beam energy 2.9 MeV, the charge 23 pC/bunch, and the emittance less than 10 mm.mrad. The experiment on the gun is planed in the beginning of 2005, and the details will be discussed on the spot.

  19. Fenomen erozije cevi naoružanja / Gun barrel erosion

    Directory of Open Access Journals (Sweden)

    Slobodan Ilić

    2009-07-01

    Full Text Available U radu su prikazana dosadašnja istraživanja erozije cevi. Trošenje cevi je neizbežan proces do kojeg dolazi pri svakom opaljenju. Erozija cevi može se definisati kao progresivna povreda ili oštećenje površine cevi i proširenje kalibra usled opaljenja, koja utiče na: gubitak ili pad početne brzine projektila, tačnost i efektivnost oruđa. Kao glavni uzročnici koji utiču na intenzitet erozije cevi opisani su termički, hemijski i mehanički faktori. Njihov uticaj prikazan je u interakciji cev-projektil-barutno punjenje. / An overview of research into gun barrel erosion is presented in this paper. The gun bore wear is an unavoidable process during normal firing. The wear can be defined as progressive damage of the bore surface and enlargement of the bore, ultimately resulting in loss in the muzzle velocity, range and accuracy. Thermal, chemical and mechanical factors are described as major factors of gun barrel erosion. The influence of these factors is presented in the interaction of gun tube - projectile - propellant.

  20. Electrical properties of a co-axial plasma gun

    International Nuclear Information System (INIS)

    Allam, T.M.Y.

    1997-01-01

    The main interest of this work is to study the power discharge of capacitor bank through a coaxial electrodes system. Such arrangement is called the coaxial gun or coaxial accelerator. It is used in jet propulsion and in triggering of discharge in turbo engines or in plasma combustion arrangement. The main goal is to find out the efficiency of the system in both cases. coaxial plasma gun system has been constructed for this course of study. The plasma gun system consists of the plasma gun tube and the discharge chamber, the capacitor bank, the triggering system the vacuum system, the power supply, and safety and dumping system. Simple and efficient diagnostic techniques were used to measure the different parameters concerning the coaxial discharge system such as the Rogowski loop, the voltage divider, the magnetic probes, the double electric probe. Results were obtained using argon gas with an operating pressure ranging from 0.1 torr to 1 torr. The peak discharge current in the first half cycle was 44 K A with rise time of 6.25 μs for a bank charging voltage of 10 kv and gas pressure of 0.9 torr. 4-26 figs., 4-8 tabs., 33 refs

  1. America, guns and freedom: Part II - An international perspective.

    Science.gov (United States)

    Faria, Miguel A

    2012-01-01

    The need for reducing gun violence is discussed along with the necessity for citizens to assume some responsibility for protecting themselves, their families, and their property from criminal elements because the police cannot physically be everywhere to protect us all of the time. The problem of sensationalization of gun crimes by the media, multiple shootings by deranged individuals, accidents with firearms, suicide rates, and children with guns are discussed.The relationship of civilian disarmament in the context of tyrannical governments and genocide are also explored. Incidents in which liberty has been extinguished because firearms have been banned and citizens have been disarmed by increasingly oppressive governments, and the converse, countries where freedom has been preserved by armed citizens are also described. We conclude that guns in the hands of law-abiding citizens deter crimes, and nations that trust their citizens with firearms have governments that sustain liberty and affirm individual freedom. Governments that do not trust their citizens with firearms tend to be despotic and tyrannical, and are a potential danger to good citizens - and a peril to humanity.

  2. A line beam electron gun for rapid thermal processing

    Science.gov (United States)

    Pauli, M.; Müller, J.; Hartkopf, K.; Barth, T.

    1992-04-01

    A line beam electron gun based on the Pierce gun type was developed. The line cathode was realized by a directly heated tungsten rod. The temperature distribution along the tungsten rod was simulated numerically. The simulation shows a flat temperature across 2/3 of the cathode length and it agrees with appropriate measurable parameters. The beam profiles of the electron gun perpendicular to the line direction were examined as a function of electrical and geometrical parameters: The space-charge distribution in front of the cathode was found to be responsible for the shape of the beam profile. The shape of the beam profile is weakly influenced by the acceleration to the anode. The heating current induced voltage drop along the cathode was found to be responsible for the nonuniform emission in line direction. A model for the emission behavior of the line beam electron gun was developed. The model is based on the results of the measurements and on a numerical simulation of the potential distribution in the area between Pierce reflectors and anode. The emission model shows a solution to homogenize the emission by a suitable variation of geometrical parameters in line direction. A linear variation was realized in experiment which enables a uniform emission across 2/3 of the cathode length. The beam profile is adjustable by a bias voltage between the cathode and the Pierce reflectors.

  3. Electron Gun for Computer-controlled Welding of Small Components

    Czech Academy of Sciences Publication Activity Database

    Dupák, Jan; Vlček, Ivan; Zobač, Martin

    2001-01-01

    Roč. 62, 2-3 (2001), s. 159-164 ISSN 0042-207X R&D Projects: GA AV ČR IBS2065015 Institutional research plan: CEZ:AV0Z2065902 Keywords : Electron beam-welding machine * Electron gun * Computer- control led beam Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.541, year: 2001

  4. Burning properties and mechanical integrity of aged gun propellants

    NARCIS (Netherlands)

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

    2017-01-01

    Conventional gun propellants exhibit the phenomenon of nitrocellulose (NC) decomposition. Besides an effect on thermal stability of propellants, decomposition of NC has an effect on the mechanical integrity of the propellant grains. Enhanced grain fracture may lead to unacceptable changes of the

  5. High perveance electron gun for the electron cooling system

    International Nuclear Information System (INIS)

    Korotaev, Yu.; Meshkov, I.; Petrov, A.; Sidorin, A.; Smirnov, A.; Syresin, E.; Titkova, I.

    2000-01-01

    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 μA/V 3/2 , 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)

  6. Fundamentals for a terahertz-driven electron gun

    DEFF Research Database (Denmark)

    Lange, Simon Lehnskov; Olsen, Filip D.; Iwaszczuk, Krzysztof

    2017-01-01

    dipoles placed with a small gap in between. We conclude that it is possible to make ultra-bright electron bunches shorter than 1 ps and accelerate them to the low keV range over 15 mu m using only a single THz transient. Our results are fundamental to understand and build a THz-driven electron gun....

  7. Guns on Campus: A Current Debate. E-Fact Sheet

    Science.gov (United States)

    Higher Education Center for Alcohol, Drug Abuse, and Violence Prevention, 2010

    2010-01-01

    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…

  8. Magnetic-gun igniter for controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Garwin, R.L.; Muller, R.A.; Richter, B.

    1979-01-01

    A conceptual design for the magnetic gun is given in order to show that the various parameters required turn out to be reasonable (in an engineering sense). An engineering design will necessarily turn out to be far more complex; the purpose of the following calculations is merely to show that the basic idea looks sufficiently good to warrant further work

  9. Numerical modelling of the CEBAF electron gun with EGUN

    International Nuclear Information System (INIS)

    Liger, P.; Krafft, G.A.

    1991-01-01

    The electron source used in the injector for the CEBAF accelerator is a Hermosa electron gun with a 2 mm diameter cathode and a control electrode. It produces a 100 keV electron beam to be focused on the first of two apertures which comprise an emittance filter. A normalized emittance of less than π mm mrad at 1.2 mA is set by the requirements of the final beam from the CEBAF linac, since downstream of the filter, a system of two choppers and a third aperture removes 5/6 of the current. In addition, for RF test purposes a higher current of about 5 mA is needed, possibly at higher emittance. This paper presents a way of calculating the characteristics of the CEBAF electron gun with the gun design code EGUN, and the accuracy of the results is discussed. The transverse shape of the beam delivered by the gun has been observed, and its current measured. A halo around the beam has been seen, and the calculations can reproduce this effect

  10. Developments in the electron gun simulation program, EGUN

    International Nuclear Information System (INIS)

    Herrmannsfeldt, W.B.

    1994-11-01

    This paper discusses the developments in the electron gun simulation programs that are based on EGUN with its derivatives and supporting programs. Much of the code development has been inspired by technology changes in computer hardware; the implications of this evolution on EGN2 are discussed. Some examples and a review of the capabilities of the EGUN family are described

  11. Developments in the electron gun simulation program, EGUN

    Science.gov (United States)

    Herrmannsfeldt, W. B.

    1995-07-01

    This paper discusses the developments in the electron gun simulation programs that are based on EGUN with its derivatives and supporting programs. Much of the code development has been inspired by technology changes in computer hardware; the implications of this evolution on EGN2 are discussed. Some examples and a review of the capabilities of the EGUN family are described.

  12. Enhanced ECR ion source performance with an electron gun

    International Nuclear Information System (INIS)

    Xie, Z.; Lyneis, C.M.; Lam, R.S.; Lundgren, S.A.

    1991-01-01

    An electron gun for the advanced electron cyclotron resonance (AECR) source has been developed to increase the production of high charge state ions. The AECR source, which operates at 14 GHz, is being developed for the 88-in. cyclotron at Lawrence Berkeley Laboratory. The electron gun injects 10 to 150 eV electrons into the plasma chamber of the AECR. With the electron gun the AECR has produced at 10 kV extraction voltage 131 e μA of O 7+ , 13 e μA of O 8+ , 17 e μA of Ar 14+ , 2.2 e μA of Kr 25+ , 1 e μA of Xe 31+ , and 0.2 e μA of Bi 38+ . The AECR was also tested as a single stage source with a coating of SiO 2 on the plasma chamber walls. This significantly improved its performance compared to no coating, but direct injection of electrons with the electron gun produced the best results

  13. "Fist, Stick, Knife, Gun": Getting Real in Upward Bound.

    Science.gov (United States)

    Pace, Barbara G.; Adkins, Theresa A.

    2002-01-01

    Describes how a teacher found literature for Upward Bound students. Presents Geoffrey Canada's "Fist, Stick, Knife, Gun: A Personal History of Violence in America" as a nonfiction work to provide clarity and connections that might not have been available in a fictional work, yet it had elements of literary fiction that made the text…

  14. Gas-gun facility for shock wave research at BARC

    International Nuclear Information System (INIS)

    Gupta, S.C.; Jyoti, G.; Suresh, N.; Sikka, S.K.; Chidambaram, R.; Agarwal, R.G.; Roy, S.; Kakodkar, A.

    1995-01-01

    For carrying out shock-wave experiments on materials, we have built a 63 mm diameter gas-gun facility at our laboratory. It is capable of accelerating projectiles (about half kg in weight) to velocities up to 1 km/s using N 2 and He gases. These on impacting a target generate shock pressures up to 40 GPa, depending upon the impedance of the impactor and the target. The barrel of the gun is slotted so that a keyed projectile can be fired for combined compression- shear studies. Large samples can be shocked (about 60 mm diameter and 5-10 mm thick), with pressures lasting for a few microseconds. The gun is similar in design to the one at Washington State University. A number of diagnostic techniques have also been developed. These include measurement of projectile velocity, tilt between the impactor and the target, shock velocity in the target, and time resolved in-material stress wave histories in the shock loaded samples. Recovery capsules have also been made to retrieve shocked samples on unloading, which are then analysed using microscopic techniques like x-ray diffraction, Raman and electron microscopy. The gun has been performing well and has already been used for a few phase transition studies. (author). 73 refs., 42 figs

  15. Polarized Light Sources for photocathode electron guns at SLAC

    International Nuclear Information System (INIS)

    Woods, M.; Frisch, J.; Witte, K.; Zolotorev, M.

    1992-12-01

    We describe current and future Polarized Light Sources at SLAC for use with photocathode electron guns to produce polarized electron beams. The SLAC experiments SLD and E142 are considered, and are used to define the required parameters for the Polarized Light Sources

  16. America, guns and freedom: Part II — An international perspective

    Science.gov (United States)

    Faria, Miguel A.

    2012-01-01

    The need for reducing gun violence is discussed along with the necessity for citizens to assume some responsibility for protecting themselves, their families, and their property from criminal elements because the police cannot physically be everywhere to protect us all of the time. The problem of sensationalization of gun crimes by the media, multiple shootings by deranged individuals, accidents with firearms, suicide rates, and children with guns are discussed. The relationship of civilian disarmament in the context of tyrannical governments and genocide are also explored. Incidents in which liberty has been extinguished because firearms have been banned and citizens have been disarmed by increasingly oppressive governments, and the converse, countries where freedom has been preserved by armed citizens are also described. We conclude that guns in the hands of law-abiding citizens deter crimes, and nations that trust their citizens with firearms have governments that sustain liberty and affirm individual freedom. Governments that do not trust their citizens with firearms tend to be despotic and tyrannical, and are a potential danger to good citizens — and a peril to humanity. PMID:23227440

  17. Development of Field-Emission Electron Gun from Carbon Nanotubes

    CERN Document Server

    Hozumi, Y

    2004-01-01

    Aiming to use a narrow energy-spread electron beam easily and low costly on injector electron guns, we have been tested field emission cathodes of carbon nanotubes (CNTs). Experiments for these three years brought us important suggestions and a few rules of thumb. Now at last, anode current of 3.0 [A/cm2

  18. Algorithm Design for Grip-Pattern Verification in Smart Gun

    NARCIS (Netherlands)

    Shang, X.; Veldhuis, Raymond N.J.; Bazen, A.M.; Ganzevoort, W.P.T.

    2005-01-01

    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

  19. Decay of plasma cluster accelerated by coaxial gun

    International Nuclear Information System (INIS)

    Kubes, P.; Hruska, J.; Bacilek, J.

    1978-01-01

    The decay of an air cluster accelerated in a vacuum tube is studied. The time dependence of electron density and electron temperature is introduced and the effect of different recombination processes is discussed. The observed plasma decay shows an exponential law, is independent of the gun regime and may be explained by ambipolar diffusion to the tube walls. (author)

  20. Virtual cathode driven by short pulse electron gun

    Energy Technology Data Exchange (ETDEWEB)

    Spassovsky, I P; Cho, Sung Oh; Lee, Jongmin; Lee, Byung-Cheol; Jeong, Young Uk [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of). Laboratory for Quantum Optics; Messina, G [ENEA, Roma-Frascati (Italy). INN-FIS-LAC; Yovchev, I G; Nikolov, N A [Sofia Univ. (Bulgaria). Faculty of Physics

    1997-12-31

    An electron gun has been developed by ENEA (Italy) to power a free-electron laser operating in the far infrared region. The device can also be used to drive various microwave sources. Numerical simulations were performed for the planned foil-diode vircator experiment to be carried out by ENEA. (author). 5 figs., 4 refs.