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Dizertační práce se zabývá problematikou výpočtu vlivu coulombovských interakcí částic na parametry emitovaného elektronového svazku v blízkosti Schottkyho a studené katody. Práce poskytuje základní předhled o problematice, popisuje vytvořené modely emisních zdrojů a metodu simulace Monte Carlo. Představuje novou metodu generování vstupních dat, která klade větší důraz na přesnou simulaci emisního procesu. Pozornost je zde věnována zejména vlivu interakcí na energiovou šířku, velikost virtuálního zdroje a jas katody v závislosti na velikosti poloměru hrotu a emisním proudu. Sledováním vývoje energiové šířky bylo zjištěno, že naprostá většina interakcí se odehrává v prostoru do několika mikrometrů od hrotu katody. Závislost spočtené celkové energiové šířky na úhlové intenzitě je ve shodě s dostupnými experimentálními daty. Spočtené energiové rozšíření vlivem coulombovských interakcí bylo srovnáno s hodnotami vypočtenými pomocí vzorců založených na analytických přiblíženích. Bylo zjištěno, že některé z nich přijatelně předpovídají trendy ale nemohou být použity pro kvantitativní odhad.

Syftet med denna studie var att öka kunskapen om motiv som leder till att medborgare organiserar sig mot vapenvåld och för en tryggare ort, efter att en ung man i området skjutits till döds på öppen gata. Vidare var syftet att få en förståelse för hur de mobiliserande processerna tar sig uttryck i Skarpnäck. Studiens frågeställningar har besvarats genom kvalitativa intervjuer med sju medborgare som deltar i mobiliseringen, samt ostrukturerade observationer av mobiliseringens skeende. Studiens data har analyserats med teorin om sociala rörelser, samt Bourdieus kapitalformer i kombination med begreppen fält och habitus. Resultaten visar på att motiven till deltagandet grundar sig i en kombination av faktorer, som exempelvis sociala relationer, platsidentitet och gemenskap. Vidare framkommer det av resultatet att området präglas av bland annat boendesegregation och resursbrister i den kommunala skolan, som på olika sätt bidrar med en distans mellan medborgarna och aktörer inom den offentliga sektorn. Mobiliseringen i Skarpnäck utgörs av ett kritiskt och kollektivt handlade som fokuserar på att kartlägga behov i området, vilket sedermera framförts till Stadsdelsnämnden i form av ett medborgarförslag. / The aim of this paper is to increase knowledge on the motives that lead to citizens organizing against gun violence and for a safer neighborhood, after a young man in the community was shot to death on an open street. Furthermore, the aim of this paper is to gain an understanding of how the process of mobilisation took place in Skarpnäck. The study’s questions have been answered through two research methods; qualitative interviews with seven citizens who took part in the mobilization, as well as by unstructured observations of mobilising events. Theories applied whilst analysing the collected data were social movement theoryand Bourdieu’s theory of capital as well as the terms field and habitus. Results show that citizen participation is motivated by several factors, such as social ties,  place identity and  community. Results also show that the neighborhood, amongst other things, is affected by segregation and lack of resources in the local public school, which in different ways  contribute to a distance between citizens and civil servants in the public sector. Mobilisation in Skarpnäck takes form through critical and collective action that focuses on mapping needs in the neighborhood, which are then presented to the districts committee as citizen proposals.

This paper describes the changes made from Cal Poly’s initial railgun system, the Mk. 1 railgun, to the Mk. 1.1 system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency losses. A Mk. 2 system is developed and built around donated hardware from the Naval Postgraduate School. The Mk. 2 system strove to implement an efficient, augmented, electromagnetic railgun and projectile system capable of firing an approximate 1g aluminum projectile to speeds exceeding 2 km/s. A novel three part projectile is proposed to mitigate rail and projectile degradation. Projectile and sabot system kinematic equations are derived and the projectile is designed and tested along with Mk. 2 barrel. A numerical electromechanical model is developed to predict the performance of the Mk. 2 system and projectile assembly, and predicts a final velocity for the fabricated system exceeding 3.5 km/s and an efficiency as high as 24%. Testing of the Mk. 2 system showed catastrophic failure of the projectile during initial acceleration, resulting in very short acceleration times and distance, low velocity projectiles, and low efficiencies. During further testing of various projectile configurations, the barrel structure failed due to a large internal arc. Future work for the Mk. 2 system is discussed, a revised external barrel structure suggested, and a solid, more conventional solid chevron projectile design suggested.

yes / Non-lethal weapons (NLWs) are explicitly designed and primarily employed to incapacitate personnel or material whilst minimising collateral damage to property and the environment. Existing NLWs include rubber and plastic bullets, entangling nets, chemical sprays such as OC and CS gas, and electrical stunning devices such as the `Taser¿ gun. New NLWs are on the way, which will include acoustic and microwave weapons, non-lethal landmines, malodorants, and sophisticated weapons developed through rapid advances in neuroscience and the genomics revolution. Most analysts would agree that there is a `legitimate¿ role for non-lethal weapons, both for civil and military applications. However there is considerable disagreement as to the operational effectiveness of NLWs, and the threat such weapons pose to arms conventions and international law. As usual, a balance has to be achieved where the benign advantages of developing and deploying non-lethal weapons are not outweighed by their more malign effects. In particular, emerging non-lethal technologies offer an increasing opportunity for the suppression of civil dissent and control of populations ¿ these are sometimes referred to as the `technologies of political control¿. There is a continuing need for sustained and informed commentary to such developments which highlights the impact and threats that these technologies pose to civil liberties and human rights. Because the last BNLWP Report was produced in August 2001, this edition is somewhat longer than usual so that key developments since then can be highlighted and summarised. Future BNLWRP reports will be published three times a year, and we welcome material to be considered for inclusion.

yes / Two recent detailed reports, by the U.K Northern Ireland Office (NIO) - January 2004 1 and the U.S. Council on Foreign Relations (CFR) - February 2004 2, provide further insights into current policy and technology developments in the U.K. and U.S. The NIO report is the 4th and final report of a U.K wide Steering Group set up by the Secretary of State for Northern Ireland in Summer 2000, with the objective: To establish whether a less potentially lethal alternative to baton rounds is available; and to review the public order equipment which is presently available, or could be developed, in order to expand the range of tactical options available to operational commanders. 3 In her foreword to the report Jane Kennedy, Minister of State for Northern Ireland notes that: Despite a protracted and international search for a commercially available product, we have been unable to find anything that meets the criteria of an acceptable, potentially less lethal alternative to the baton round currently in service which provides an effective capability that does not expose officers and the public to greater risk in violent public disorder.4 The NIO Report has sections looking at the Defence Science and Technology Laboratory (DSTL) programme on the development of less lethal technologies (particularly the Attenuating Energy Projectile and the Discriminating Irritant Projectile); commercial off the shelf product evaluations and update (12 Gauge Sock Round Assessment); Water Cannon; the U.K. use of less lethal technologies (with a focus on L21A1 baton rounds, CS sprays and the Taser). The report also contains a section entitled `The Management of Conflict¿ which discusses the dynamics of crowd behaviour. For a critical response to the NIO report see that from Dr. Brian Rappert.5 The CFR report provides a strong endorsement for non-lethal weapons. A key finding states: Wider integration of nonlethal weapons into the U.S. Army and Marine Corps could have reduced damage, saved lives, and helped to limit the widespread looting and sabotage that occurred after the cessation of major conflict in Iraq. Incorporating NLW capabilities into the equipment, training and doctrine of the armed services could substantially improve U.S. effectiveness in conflict, post-conflict, and homeland defense. 6 Interestingly, in describing the nonlethal capability sets (NLCS) which have been deployed in Kosovo and Iraq, and which help to provide a continuum of force between ¿don¿t shoot¿ and ¿shoot¿ 7, the CFR seems to distinguish between NLWs (rubber balls [grenades and shotgun munitions], bean bags, riot shields, Tasers, net entanglers, and caltrops), and equipment such as flash-bang grenades, laser dazzlers, and bullhorns of which it states ¿It is important to note that these are not weapons but non-lethal capabilities¿ 8 The CFR recommends expanded deployment of NLWs in the armed services, longer ranges for non-lethal payloads using precision delivery and fusing systems, and further development of millimetre-wave area-denial system (HPM weapons such as VMADS) and the advanced tactical laser (ATL). The report also argues for the need to have a bigger Joint Non-Lethal Weapons Directorate (JNLWD) or a new Non-lethal Joint Program Office (NLJPO) and for Bradford Non-Lethal Weapons Research Project (BNLWRP) ¿ Research Report 5 (May 2004) 2 closer links with the Joint Forces Command (JFCOM). In the opinion of the authors the JNLWD should also have more access into classified programmes throughout all branches of the armed services so as not to duplicate non-lethal development initiatives. To stimulate incorporation of NLWs throughout the U.S. Armed Services the CFR advocates two approaches: (1) top-down planning in the Defense department and (2) creation of demand for these [NLWs] weapons from the field as personnel gain experience with prototype equipment. 9 They argue there is a need for the top-level military and civilian leadership to be educated about NLW capabilities, not only for warfighting and peacekeeping, but also in `homeland defence in isolating a hot zone in the aftermath of a biological attack' 10. We will be referring again to both the NIO and CFR publications in other sections of this report.

The research project investigated the impact of the Firearms Control Act (FCA) 60 of 2000 in restricting gun ownership for at-risk individuals in the Pretoria North Firearm Registration Centre (FRC) policing area and identified prevention strategy as well as specific factors that contributed to this problem. Secondary prevention focuses on situational factors that reduces the means and opportunity for at-risk people to commit crime and can be applied in restricting firearms from at-risk individuals. One hundred and thirteen legal firearm owners in the Pretoria North FRC policing area responded to the questionnaire schedule. Data was also collected through interviews with Designated Firearm Officers (DFO) and court officials in that area. Specific factors have been identified that contribute to firearms landing in the hands of at-risk individuals in the Pretoria North FRC policing area. They are among others, poor administration of some sections of the FCA like background checks and section 102 and 103 unfitness declarations. The role of the DFO in continuous public education program on the FCA is also invaluable. The same goes to the general public s involvement in the identification of at-risk individuals. The South African Police Service management needs to address issues within the police service such as additional trained personnel, allocation of sufficient logistical resources like vehicles, computers and scanners to ensure effectiveness in restricting firearms from at-risk individuals. Several secondary role players have been identified that should work closely with the primary role players to address this problem. The recommendations drawn from conclusions as well as the inter-departmental role of all the different role players may assist in restricting firearms from at-risk individuals. / Police Practice / M.Tech. (Policing)

This work focuses on understanding the impact-initiated combustion of aluminum powder compacts. Aluminum is typically one of the components of intermetallic-forming structural energetic materials (SEMs), which have the desirable combination of rapid release of thermal energy and high yield strength. Aluminum powders of various sizes and different levels of mechanical pre-activation are investigated to determine their reactivity under uniaxial stress rod-on-anvil impact conditions, using a 7.62 mm gas gun. The compacts reveal light emission due to combustion upon impact at velocities greater than 170 m/s. Particle size and mechanical pre-activation influence the initiation of aluminum combustion reaction through particle-level processes such as localized friction, strain, and heating, as well as continuum-scale effects controlling the amount of energy required for compaction and deformation of the powder compact during uniaxial stress loading. Compacts composed of larger diameter aluminum particles (~70µm) are more sensitive to impact initiated combustion than those composed of smaller diameter particles. Additionally, mechanical pre-activation by high energy ball milling (HEBM) increases the propensity for reaction initiation. Direct imaging using high-speed framing and IR cameras reveals light emission and temperature rise during the compaction and deformation processes. Correlations of these images to meso-scale CTH simulations reveal that initiation of combustion reactions in aluminum powder compacts is closely tied to mesoscale processes, such as particle-particle interactions, pore collapse, and particle-level deformation. These particle level processes cannot be measured directly because traditional pressure and velocity sensors provide spatially averaged responses. In order to address this issue, quantum dots (QDs) are investigated as possible meso-scale pressure sensors for probing the shock response of heterogeneous materials directly. Impact experiments were conducted on a QD-polymer film using a laser driven flyer setup at the University of Illinois Urbana-Champaign (UIUC). Time-resolved spectroscopy was used to monitor the energy shift and intensity loss as a function of pressure over nanosecond time scales. Shock compression of a QD-PVA film results in an upward shift in energy (or a blueshift in the emission spectra) and a decrease in emission intensity. The magnitude of the shift in energy and the drop in intensity are a function of the shock pressure and can be used to track the particle scale differences in the shock pressure. The encouraging results illustrate the possible use of quantum dots as mesoscale diagnostics to probe the mechanisms involved in the impact initiation of combustion or intermetallic reactions.

The research project investigated the impact of the Firearms Control Act (FCA) 60 of 2000 in restricting gun ownership for at-risk individuals in the Pretoria North Firearm Registration Centre (FRC) policing area and identified prevention strategy as well as specific factors that contributed to this problem. Secondary prevention focuses on situational factors that reduces the means and opportunity for at-risk people to commit crime and can be applied in restricting firearms from at-risk individuals. One hundred and thirteen legal firearm owners in the Pretoria North FRC policing area responded to the questionnaire schedule. Data was also collected through interviews with Designated Firearm Officers (DFO) and court officials in that area. Specific factors have been identified that contribute to firearms landing in the hands of at-risk individuals in the Pretoria North FRC policing area. They are among others, poor administration of some sections of the FCA like background checks and section 102 and 103 unfitness declarations. The role of the DFO in continuous public education program on the FCA is also invaluable. The same goes to the general public s involvement in the identification of at-risk individuals. The South African Police Service management needs to address issues within the police service such as additional trained personnel, allocation of sufficient logistical resources like vehicles, computers and scanners to ensure effectiveness in restricting firearms from at-risk individuals. Several secondary role players have been identified that should work closely with the primary role players to address this problem. The recommendations drawn from conclusions as well as the inter-departmental role of all the different role players may assist in restricting firearms from at-risk individuals. / Police Practice / M.Tech. (Policing)

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-01-10T14:00:21Z No. of bitstreams: 1 humbertovargasduque (1).pdf: 2897920 bytes, checksum: 904a8ff36edd0079149dfe6e3be69aed (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: Favor corrigir: Membro da banca: Filho, Jayr de Amorim on 2018-01-23T11:49:04Z (GMT) / Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-01-23T13:12:19Z No. of bitstreams: 1 humbertovargasduque (1).pdf: 2897920 bytes, checksum: 904a8ff36edd0079149dfe6e3be69aed (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: Favor verificar nome do arquivo, existe o número (1) humbertovargasduque (1).pdf on 2018-01-23T13:14:55Z (GMT) / Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-01-23T13:22:21Z No. of bitstreams: 1 humbertovargasduque.pdf: 2897920 bytes, checksum: 904a8ff36edd0079149dfe6e3be69aed (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-01-24T13:40:22Z (GMT) No. of bitstreams: 1 humbertovargasduque.pdf: 2897920 bytes, checksum: 904a8ff36edd0079149dfe6e3be69aed (MD5) / Made available in DSpace on 2018-01-24T13:40:22Z (GMT). No. of bitstreams: 1 humbertovargasduque.pdf: 2897920 bytes, checksum: 904a8ff36edd0079149dfe6e3be69aed (MD5) Previous issue date: 2012-06-19 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho consiste no desenvolvimento, implantação e caracterização de um Analisador Cilíndrico Dispersivo 1270 em um Espectrômetro de Perda de Energia de Elétrons (EPEE) operando na região de energia de impacto de 10 a 200 eV, que está sendo desenvolvido no Laboratório de Espectroscopia Atômica e Molecular – LEAM da UFJF. Além do analisador, foram também desenvolvidos diversos trabalhos para otimização do circuito de controle do canhão de elétrons monocromatizado do EPEE, o que gerou ótima estabilidade, acarretando em um ganho considerável em intensidade do feixe produzido e melhoria no manuseio do mesmo. É descrito a implementação da variação angular da plataforma giratória que apóia o Analisador Cilíndrico Dispersivo 1270, bem como a medida desta variação, e também, do sistema de injeção do feixe gasoso através de uma cânula de molibidênio isolada eletricamente, com movimento verticalem relação ao disco onde estão instalados o canhão e analisador. Os testes de desempenho do Espectrômetro foram feitos a partir da análise da resolução de Energia ΔE do EPEE. Obtivemos ótimos resultados quanto a transmissão do feixe de elétrons monocromatizado através da região de colisão chegando até a região de detecção do espectrômetro. É descrito, também, uma avaliação das melhorias feitas no Circuito de Controle do Canhão de Elétrons Monocromatizado, obtendo excelentes resultados quanto a intensidade do feixe de elétrons na faixa de energia de 0,1-100 eV. / This work describes the development, implementation and characterization of a Cylindrical Dispersive Analyzer 1270 on a Electron Energy Loss Spectrometer (EELS) operating in the region of impact energy from 10 to 200eV, which is being developed at the Laboratory of Atomic Spectroscopy and Molecular – LEAM UFJF. In the analyzer, several studies have also been developed to optimize the control circuit of the monochromatized electron gun of the EELS, which generated great stability, resulting in a considerable gain in intensity of the beam produced and improved handling. We describe the implementation of the angular variation of the turntable that supports the Cylindrical Dispersive Analyzer 1270, and the measure of variation, and also injection system of the gas through a beam cannula molybdenum electrically isolated, with vertical movement relative to disk where the monochromatized electron gun and the energy analyzer of electrons are installed. Performance tests of the spectrometer were made from the analysis of the energy resolution ΔE of the EELS. We obtained excellent results about transmission of the electron beam across the monochromatization region collision reaching the detection region of the spectrometer. We describe also an assessment of the improvements made in the Control Circuit of the Monochromatized Electron Gun, obtaining excellent results for the intensity of the electron beam in the energy range 0.1-100 eV.