Unexploded Ordnance (UXO) contamination presents a considerable level of danger in almost all post-conflict environments. Globally there are a vast amount of casualties every year. However, accurate numbers of casualties is hard to obtain both globally and locally. The purpose of this thesis is to examine how UXO affects Human Security in Lao PDR. The methodology used is a theory consuming empirical and heuristic method. The thesis is a case study that does not attempt to generalize but to understand and analyze the relation between UXO and Human Security in the context of Lao PDR. The theory used in the thesis is Human Security based on the concept of the 1994 UNDP Human Development Report. The findings of the thesis make clear the connection between UXO contamination and lack of Human Security in Lao PDR. The direct and indirect consequences of UXO contamination are explored. Finally, the thesis works at a broader societal level where the links to poverty and development are illustrated.

<p>Explosive boiling is a phenomenon encountered in severe nuclear reactor accidents during quench cooling, core relocation or through fuel-coolant interactions. The mitigation of accident conditions is important from a safety standpoint since explosive boiling is potentially capable of destructive forces. Explosive boiling occurs when coolant water encounters a hot solid surface and absorbs a high degree of superheat. The resultant boiling mode is violent and features the rapid decomposition of liquid on a microsecond timescale with liquid atomization and ejection. In this study, the explosive boiling force of a single water droplet impacting hot solid surfaces was estimated with secondary droplet analyses using high-speed imaging.</p> <p>A water droplet at 25°C with a Weber number of 432 impacted perpendicular to solid surfaces at temperatures from 30-700°C. Solid surfaces of copper, brass and stainless steel varied in thermal diffusivity from 3.48 x10^-6to 1.17 x10^-4m²/s. Curved and flat impact surfaces were also tested. Explosive boiling was most prominent when the instantaneous interface temperature attained the superheat limit temperature (300°C ±17°C). Maximum boiling force was encountered at the superheat limit with reduced force at surface temperatures in the nucleate boiling regime and near zero force in the film boiling regime. Thermal disintegration dominates over inertial break up of the droplet near the superheat limit region. Thermal diffusivity effects were only distinguishable in the 250-450°C region where increasing thermal diffusivity translated to larger boiling forces. Secondary droplet counts, size, trajectories were dependent on the boiling mode present at the interface with very strong variances caused by thermal break up of the initial droplet. Explosive boiling caused greater fragmentation creating more secondary droplets with smaller sizes and larger ejection trajectories. A curved surface showed slightly higher explosive boiling force in the superheat limit region but with negligible effects on secondary droplet properties.</p> / Master of Applied Science (MASc)

A possible mechanism to explain the origin of around 35 neutron–deficient stable isotopes with mass A≥75 between 74 Se and 196 Hg, known as the p–nuclei is the nucleosynthesis in the proton–rich neutrino–driven winds of core–collapse supernovae via the νp–process. However this production scenario is very sensitive to the underlying supernova dynamics and the nuclear physics input. As far as nuclear uncertainties are concerned, the breakout reaction from the pp-chains, 7Be(α, γ)11C, has been identified as an important link which can influence the nuclear flow and therefore the efficiency of the νp–process. However its reaction rate is not well known over the relevant energy range (T9 = 1.5–3). In this thesis we report on the direct first measurement of two resonances of the 7Be(α, γ)11 C reaction with previously unknown strengths using an intense radioactive 7Be beam from ISAC and the DRAGON recoil separator in inverse kinematics. Since resonance strength measurements with low mass beams using recoil separators depend strongly on the recoil angular distribution, which can exceed the acceptance of the separator, we first performed a proof–of–principle test by measuring a known resonance of the 6Li(α, γ)10B reaction, which also presents a similar challenge. Our results from the 6Li(α, γ)10B reaction are in agreement with literature, showing that DRAGON can measure resonance strengths of reactions for which the maximum momentum cone of the recoils exceeds its acceptance. From the newly measured 7Be(α, γ)11C resonance strengths we calculated the new reaction rate which is lower than the current recommended by 10–50% and constrained to 5–10% in the relevant temperature region. Using this new rate, we performed detailed nucleosynthesis calculations which suggest that there is no effect the production of light p–nuclei, but a production increase for CNO elements of up to an order of magnitude is observed. / Dissertation / Doctor of Philosophy (PhD)

This thesis describes XL, an x-ray imaging simulator for luggage inspection. This software system runs on a workstation and models x-ray sources, x-ray detectors and objects between them. A simple graphical interface permits the user to specify simulation parameters and inputs. XL then uses Monte Carlo methods to simulate x-ray interaction with matter, including the photoelectric effect, coherent scattering, and incoherent scattering. Finally, XL can produce x-ray images which agree closely with experimental data obtained from a commercial luggage scanner. The simulator will be a valuable tool in the development of future x-ray scanners, particularly those designed to detect explosives in luggage. / Master of Science

An under-body blast (UBB) refers to the use of a roadside explosive device to target a vehicle and its occupants. During Operation Iraqi Freedom, improvised explosive devices (IEDs) accounted for an estimated 63% of US fatalities. Furthermore, advancements in protective equipment, combat triage, and treatment have caused an increase in IED casualties surviving with debilitating injuries. Military vehicles have been common targets of IED attacks because of the potential to inflict multiple casualties. Anthropomorphic test devices (ATDs) are mechanical human surrogates designed to transfer loads and display kinematics similar to a human subject. ATDs have been used successfully by the automotive industry for decades to quantify human injury during an impact and assess safety measures. Currently the Hybrid III ATD is used in live-fire military vehicle assessments. However, the Hybrid III was designed for frontal impacts and demonstrated poor biofidelity in vertical loading experiments. To assess military vehicle safety and make informed improvements to vehicle design, a novel Anthropomorphic Test Device (ATD) was developed and optimized for vertical loading. ATDs, commonly referred to as crash dummies, are designed to estimate the risk of injuries to a human during an impact. The main objective of this study was to develop and validate a Finite Element (FE) model of the ATD lower limb. / Master of Science

Les instabilités paramétriques non linéaires (NL) ont été observées sur les ondes magnéto-élastiques dans le cas d’un couplage de trois quasi-phonons sous pompage électromagnétique. La théorie en prédit une dynamique supercritique explosive, mais limitée expérimentalement par le décalage de fréquence dû aux fortes nonlinéarités. La dynamique supercritique des instabilités paramétriques NL est étudiée dans deux matériaux antiferromagnétiques "plan facile" (AFEP): l’hématite α-Fe2O3 et le borate de fer FeBO3. Ces matériaux possèdent une très grande NL acoustique effective en raison du couplage magnéto-élastique élevé. Les mécanismes de limitation de la dynamique explosive ont été analysés à l'aide de l'approximation anharmonique. La compensation du décalage fréquentiel NL par une modulation de phase singulière du pompage a été proposée et théoriquement vérifiée, puis utilisée pour l’observation expérimentale de la dynamique supercritique explosive des excitations de trois quasi-phonons dans les résonateurs magnéto-élastiques. Les études sur FeBO3 ont été réalisées dans la gamme de température 77 K - 293 K où les paramètres magnéto-élastiques du cristal varient de façon significative. Un modèle fortement non linéaire des excitations de trois quasi-phonons dans les AFEPs a été développé. Les simulations numériques sont en accord avec les résultats expérimentaux. Les études théoriques de couplage de trois ondes magnéto-élastiques progressives ont été effectuées sur la base de modèles théoriques prenant en compte la non-linéarité cubique des cristaux AFEP réels. Les simulations numériques prévoient un comportement explosif et une localisation spatiale des triades générées / Recently discovered nonlinear parametric instabilities occur when nonlinear parameter of a system is modulated. These instabilities were reported on magnetoelastic waves as three quasi-phonon coupling under electromagnetic pumping. Theoretical studies predicted supercritical explosive dynamics of these instabilities. Experimentally such singular behavior is limited by strong nonlinear frequency shift.Presented work studies supercritical dynamics of nonlinear parametric instabilities in two easy plane antiferromagnets (AFEP): hematite α-Fe2O3 and iron borate FeBO3. These materials possess unprecedented effective acoustic nonlinearity due to high magneto-elastic coupling. Limiting mechanisms of explosive dynamics were analyzed with the help of anharmonic approximation. Nonlinear frequency shift compensation via singular pumping field phase modulation was suggested and theoretically approbated. This technique was successfully used for experimental observation and investigation of supercritical explosive dynamics of three quasi-phonon excitations in magnetoelastic resonators. Iron borate studies were performed in the temperature range 77 K – 293 K where magnetoelastic parameters of the crystal vary essentially. Strongly nonlinear model of three quasi-phonon excitations in AFEPs was developed. Numerical simulations of the model showed good agreement with experimental results.Theoretical studies of three travelling magnetoelastic waves coupling are performed on the basis of suggested theoretical models that take into account cubic nonlinearity of real AFEP crystals. Numerical simulations of the models suggest explosive behavior and spatial localization of generated triads

A method to estimate blast-induced damage in rock considering both stress waves and gas expansion phases is presented. The method was developed by assuming a strong correlation between blast-induced damage and stress wave amplitudes, and also by adapting a 2D numerical method to estimate damage in a 3D real case. The numerical method is used to determine stress wave damage and provides an indication of zones prone to suffer greater damage by gas expansion. The specific steps carried out in this study are: i) extensive blast monitoring in hard rock at surface and underground test sites; ii) analysis of seismic waveforms in terms of amplitude and frequency and their azimuthal distribution with respect to borehole axis, iii) measurement of blast-induced damage from single-hole blasts; iv) assessment and implementation of method to utilize 2D numerical model to predict blast damage in 3D situation; v) use of experimental and numerical results to estimate relative contribution of stress waves and gas penetration to damage, and vi) monitoring and modeling of full-scale production blasts to apply developed method to estimate blast-induced damage from stress waves. The main findings in this study are: i) both P and S-waves are generated and show comparable amplitudes by blasting in boreholes; ii) amplitude and frequency of seismic waves are strongly dependent on initiation mode and direction of propagation of explosive reaction in borehole; iii) in-situ measurements indicate strongly non-symmetrical damage dependent on confinement conditions and initiation mode, and existing rock structure, and iv) gas penetration seems to be mainly responsible for damage (significant damage extension 2-4 borehole diameters from stress waves; > 22 from gas expansion). The method has the potential for application in regular production blasts for control of over-breaks and dilution in operating mines. The main areas proposed for future work are: i) verification of seismic velocity changes in rock by blast-induced damage from controlled experiments; ii) incorporation of gas expansion phase into numerical models; iii) use of 3D numerical model and verification of crack distribution prediction; iv) further studies on strain rate dependency of material strength parameters, and v) accurate measurements of in-hole pressure function considering various confinement conditions.

A method to estimate blast-induced damage in rock considering both stress waves and gas expansion phases is presented. The method was developed by assuming a strong correlation between blast-induced damage and stress wave amplitudes, and also by adapting a 2D numerical method to estimate damage in a 3D real case. The numerical method is used to determine stress wave damage and provides an indication of zones prone to suffer greater damage by gas expansion. The specific steps carried out in this study are: i) extensive blast monitoring in hard rock at surface and underground test sites; ii) analysis of seismic waveforms in terms of amplitude and frequency and their azimuthal distribution with respect to borehole axis, iii) measurement of blast-induced damage from single-hole blasts; iv) assessment and implementation of method to utilize 2D numerical model to predict blast damage in 3D situation; v) use of experimental and numerical results to estimate relative contribution of stress waves and gas penetration to damage, and vi) monitoring and modeling of full-scale production blasts to apply developed method to estimate blast-induced damage from stress waves. The main findings in this study are: i) both P and S-waves are generated and show comparable amplitudes by blasting in boreholes; ii) amplitude and frequency of seismic waves are strongly dependent on initiation mode and direction of propagation of explosive reaction in borehole; iii) in-situ measurements indicate strongly non-symmetrical damage dependent on confinement conditions and initiation mode, and existing rock structure, and iv) gas penetration seems to be mainly responsible for damage (significant damage extension 2-4 borehole diameters from stress waves; > 22 from gas expansion). The method has the potential for application in regular production blasts for control of over-breaks and dilution in operating mines. The main areas proposed for future work are: i) verification of seismic velocity changes in rock by blast-induced damage from controlled experiments; ii) incorporation of gas expansion phase into numerical models; iii) use of 3D numerical model and verification of crack distribution prediction; iv) further studies on strain rate dependency of material strength parameters, and v) accurate measurements of in-hole pressure function considering various confinement conditions.

La vaporisation explosive, ou flashing, par dépressurisation rapide du C6F14 au travers d'une vanne à boisseau sphérique est analysée expérimentalement sur une grande plage de surchauffe. Les visualisations rapides montrent un jet s’ouvrant très largement en aval, preuve de l'existence d'un fort gradient de pression. Des mesures locales par sonde optique et par vélocimétrie phase Doppler ont permis de caractériser tailles, vitesses, concentration et flux numérique des gouttes en fonction de la surchauffe. La faible influence du degré de surchauffe sur la remontée en pression et sur les tailles et flux de gouttes suggère que le champ de pression s’adapte, et que par conséquent le liquide est soumis à une surchauffe locale bien plus faible que la surchauffe globale imposée. Différents scenarii sont discutés pour expliquer les observations, dont le fait que les tailles de gouttes sont peu sensibles à la surchauffe. Celui basé sur l’existence d’un front d’ébullition est le plus probable. / Depressurization (flashing) experiments through a ball valve were conducted with C6F14 for a large range of superheat. High-speed imaging shows a rapid and wide expansion of the jet, which evidences strong pressure gradients. Local measurements with phase detection optical probes and phase Doppler velocimetry were used to characterize size, speed, concentration and volumetric flux of drops as a function of superheat. The level of superheat has little influence on the vaporized fraction and on drop size and flux: this suggests that due to strong pressure gradients the liquid sees a much weaker level of superheat than the global superheat imposed on the system. Different scenarii are discussed to explain observations, in particular the fact that drop size remains approximately constant independent of the superheat. A scenario based on the existence of a boiling front seems to be the most consistent.

Modelling the full event of an underwater explosion (UNDEX) is complex and requires advanced modelling methods in order to achieve accurate responses. The process of an UNDEX includes a series of events that has to be considered. When a detonation is initiated, a shock-wave propagates and the rest products from the explosive material creates a gaseous bubble with high pressure which pulsates and impacts the surroundings. Reflections of the initial shock-wave can also appear if it hits the sea floor, water surface or other obstacles. There are different approaches how to numerically model the impact of an UNDEX on a structure, some with analytical approaches without a water domain and others where a water domain has to be modelled. This master’s thesis focuses on two modelling methods that are available in the finite element software LS-DYNA. The simpler method is called Sub-Sea Analysis (SSA) and does not require a water domain, thus it can be beneficial to use in an early design stage, or when only approximated responses are desired. To increase the accuracy, a more complex method called S-ALE can be used. By implementing this method, the full process of an UNDEX can be studied since both the fluid domain and explosive material are meshed. These methods are studied separately together with a combination of them. Another important aspect to be considered is that oscillations of a structure submerged in water differs from the behavior it has in air. Depending on the numerical method used, the impact of the water can be included. Natural frequencies of structures submerged in water are studied, how it changes and how the methods takes this into account. To verify the numerical models, experiments were executed with a cylindrical test object where the distance and weight of charge were altered through out the test series. It was found that multiple aspects affects the results from the experiments, that are not captured in the numerical models. These aspects have for instance to do with reflections, how accurate the test object is modelled and the damping effects of the water. It is concluded that the numerical models are sensitive when small charges and fragile structures are studied. High frequency oscillations were not triggered in the experiment but found for both methods. It should be further investigated if the methods are more accurate for larger charges and stronger structures. Experiments with larger water domain would also be beneficial to reduce effects from reflections, as well as a more accurate model of the cylinder in the simulations.