Dissertations / Theses on the topic 'Explosion parameters'

Objective: Particular testing by functional decomposition of the automated driving function can potentially contribute to reducing the effort of validating highly automated driving functions. In this study, the required size of test suites for scenario-based testing and the potential to reduce it by functional decomposition are quantified for the first time. Methods: The required size of test suites for scenario-based approval of a so-called Autobahn-Chauffeur (SAE Level 3) is analyzed for an exemplary set of scenarios. Based on studies of data from failure analyses in other domains, the possible range for the required test coverage is narrowed down and suitable discretization steps, as well as ranges for the influence parameters, are assumed. Based on those assumptions, the size of the test suites for testing the complete system is quantified. The effects that lead to a reduction in the parameter space for particular testing of the decomposed driving function are analyzed and the potential to reduce the validation effort is estimated by comparing the resulting test suite sizes for both methods. Results: The combination of all effects leads to a reduction in the test suites’ size by a factor between 20 and 130, depending on the required test coverage. This means that the size of the required test suite can be reduced by 95–99% by particular testing compared to scenario-based testing of the complete system. Conclusions: The reduction potential is a valuable contribution to overcome the parameter space explosion during the validation of highly automated driving. However, this study is based on assumptions and only a small set of exemplary scenarios. Thus, the findings have to be validated in further studies.

Nous montrons que n copies independantes d'un processus de levy x issues de points appartenant a un voisinage de 0, ont des points communs avec probabilite strictement positive si le noyau resolvant de x est fortement fellerien de densite de puissance nieme integrable au voisinge de 0. Nous donnons un resultat sur la 1-capacite d'une boule de rayon a et de centre 0 relativement ax. Nous etudions le cas particulier ou x est un processus stable. Ensuite nous donnons un critere pour que la solution d'une equation differentielle stochastique de dole ans-dade n'explose pas. Pour toute condition initiale. Enfin nous montrons une formule de changement de variable de type stratonovitch pour des processus non adaptes indexes par 0;1#2. Pour cela nous definissons des integrales de stratonovitch simple et double. Nous en deduisons une formule de type skorohod qui ne contient aucune integrale de ligne. Notre methode consiste a regulariser le processus de wiener par convolution

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальнісю 21.06.01 - “Екологічна безпека”. – Державний ВНЗ «Національний гірничий університет», Дніпропетровськ, 2012.
Диссертация на соискание учёной степени кандидата технических наук по специальности 21.06.01 - “Экологическая безопасность”. – Государственное ВУЗ «Национальный горный университет», Днепропетровск, 2012.
Dissertation on gaining of scientific degree of candidate of engineering sciences after specialty 21.06.01 is "Ecological safety". - the State VNZ «National mountain university», Dnepropetrovsk, 2012.
У дисертації вирішена актуальна наукова задача, що полягає у встановлені закономірностей розповсюдження пилової хмари після масових вибухів в залізорудних кар’єрах та рівнем її екологічної небезпеки і розробці на цій основі екологічно ефективних способів та засобів зменшення викидів пилу у довкілля. Розроблені методичні засади визначення висоти підйому пилових частинок залізорудного пилу під дією теплових чинників як при наявності вітру, так і при його відсутності. Розроблено спосіб та засіб зменшення висоти підйому пилової хмари дальності її розповсюдження, які передбачають проведення робіт з оптимізації параметрів свердловинних зарядів, а також використання в якості набійки свердловинних зарядів гумової пробки з анкерним пристроєм. Удосконалено спосіб захисту довкілля від викидів пилу шляхом зрошування пилової хмари в цілому, обґрунтовано необхідний діаметр капель води для забезпечення максимальної ефективності пилопригнічення, а також об’єм води для цого. Для транспортуваня та розбризкування води над пиловою хмарою обґрунтовано використання спеціальним чином обладнаних вертольотів. Ступінь екологічної небезпеки при впровадженні запропонованих способів та засобів знепилення досягає рівня “безпечний”.
В диссертации решена актуальная научная задача, которая заключається в установлении закономерностей рассеивания пылевого облака после массовых взрывов в железорудных карьерах и уровня изменения его экологической опасности, а также разработке на их основе экологически эффективных способов и средств снижения выбросов пыли в окружающую среду. На основании результатов анализа рассеивания пылевого облака, образовавшегося после массового взрыва, выполнена оценка опасности загрязнения прилегающих территорий по пылевому фактору. Показано, что уровень экологической опасности от загрязнения воздуха пылью в радиусе 10 км представляется как “очень опасный”, а степень загрязнения – “недопустимая”. Уровень загрязнения пылью атмосферного воздуха и прилегающих территорий зависит от высоты подъёма пылевого облака, объёмов выброса пыли, метеорологических условий и эффективности способов и средств пылеподавления. В результате анализа существующих способов и средств подавления пылевого облака сделан вывод о необходимости их совершенствования. Для оценки экологической опасности рассеивания пылевого облака разработана методика расчёта высоты его подъёма с учётом дисперсности пылевых частиц и других влияющих факторов, что позволило выполнить расчёты рассеивания пыли в атмосфере для оценки эффективности технических мероприятий, направленных на снижение или локализацию выбросов пыли и её рассеивания. Расчёты рассеивания пылевого облака при мощности взрыва 500 т “украинита”, скорости ветра 5 м/с и нормальных метеорологических условиях показали, что дальность выноса грубодисперсной железорудной пыли составляет от 0,14 до 4,4 км, а тонкодисперсной – от 40 до, примерно, 740 км. При этом удельные выбросы пыли при общей площади рассеивания до 28770 км2 достигают 1,302 кг/км2. Разработан способ снижения высоты выброса пылегазового облака при массовом взрыве на основе оптимизации параметров скважинных зарядов (удельного заряда ВВ, диаметра скважин и соотношения длины забойки и взрывчатки в скважине). Предложена также усовершенствованная конструкция забойки скважинных зарядов, которая предусматривает использование в составе забойки резиновой пробки с анкерным устройством. Расчёты показали, что при применении этих разработок высота выброса пылегазового облака при массовом взрыве может быть снижена на величину до 30%. В работе выполнены исследования параметров подавления пылевого облака путём его орошения. Получено аналитическое выражение для оценки эффективности пылеулавливания от диаметра пылевых частиц и капель воды, скорости их движения, количества орошаемой жидкости, высоты орошения облака, а также суммарного коэффициента захвата пылевых частиц каплями жидкости. Установлено, что суммарный коэффициент захвата для тонкодисперсной пыли имеет максимальное значение 0,488 при диаметре капель воды 1 – 1,5 мм. Для грубодисперсной пыли при этих диаметрах капель воды коэффициент захвата изменяется от 0,815 до 0,996. При этом удельный расход воды для подавления тонкодисперсной фракции пыли составляет 3,195 л/кг. В качестве технического средства транспортирования орошающей жидкости и разбрызгивания её над пылевым облаком предложено использование специально оборудованных вертолётов. Оценка снижения экологической нагрузки на прилегающие территории при этом показала, что общий выброс пыли из карьера при массовом взрыве может быть снижен на 90 %. Степень экологической опасности при внедрении предложенных способов и средств пылеподавления достигает уровня “безопасный”.
In dissertation an actual scientific task, that consists in set conformities to the law of distribution of dust cloud after the mass explosions in iron ore quarry and level of its ecological danger and development on this basis ecologically effective methods and facilities of reduction of influencing of the troop landing of dust on the state of environment, is decided. The methodical bases of determination of height of getting up of iron ore dust particles under action of thermal factors both at presence of wind are developed, and at his absence. Methods and facilities of reduction of height of getting up of dust cloud and distance of its distribution, which foresee conducting of works after optimization of parameters of borehole charges, and also use, are developed as the printed fabric of rubber cork with the anchor device. The method of defence of environment is improved from the troop landing of dust by irrigation of dust cloud on the whole, substantiated necessary diameter of drops of water for providing of maximal efficiency of dust suppression, and also necessary volume of water for this. For transportation and splashing of water above the dust cloud of the substantiated use by the special appearance of the equipped helicopters. The degree of ecological danger at introduction of the offered methods and facilities of dedustinq measures up "safe".

Current environmental problems have led to concerns about the condition of the environment and the effect of automobile emissions on global warming. Recent work has determined that there are other alternate forms of energy, which are cleaner burning, and can be produced from renewable resources. Some alternative sources of energy include the combustion of hydrogen in the fuel cell and ethanol. Ethanol fuel has shown significant promise due largely to its ability to be used in internal combustion engines that are currently running gasoline or gasoline ethanol blends. Previous work has shown that steam explosion is a viable pretreatment technique for the conversion of biomass to ethanol, and that medium severity conditions are the best compromise between hemicellulose recovery and cellulose digestibility. To further develop this pretreatment strategy the effect of feedstock variation (moisture content and chip size) on the steam explosion process was examined, and the effect of the substrate on subsequent fractionation and hydrolysis were evaluated. Additionally, the effect of a secondary treatment regime, post steam explosion particle size reduction, was examined for its effect on fractionation and hydrolysis efficiency. In the next series of experiments the effect of EDTA chelation, stabilization (DTMPA, Sodium Silicate, and Magnesium Sulphate), consistency, and alternative delignification techniques (oxygen and wet oxidation) were examined. The techniques, which showed an improvement in delignification efficiency, were then used to optimize chemical loading and temperature during peroxide fractionation. The manipulation of feedstock conditions (moisture content and chip size) caused noticeable variations in the properties and effectiveness of further stages of the bioconversion process. Increased chip size caused an increase in the solid recovery, increasing from 62 to 82%, with concurrent increases in the prehydrolysate sugar recovery (7.5%). Increased recovery is the result of decreased relative severity of steam treatment as chip size increases. Decreased severity affects the overall process by decreasing the recalcitrance of lignin and therefore increasing the efficacy of peroxide fractionation, which removed 16% more lignin from the largest chip size. Similarly increased initial moisture content appeared to reduce the relative severity of the treatment, prehydrolysate sugars (mainly glucose and mannose), and solid recovery. Both increasing chip size and moisture content results in a substrate that performs better in peroxide delignification and enzymatic hydrolysis. Furthermore, post steam-explosion refining solubilized more of the glucose and mannose present in the prehydrolysate, resulting in a decrease in the solid recovery, while concurrently increasing prehydrolysate sugar recovery. The resulting solid substrate was more effectively delignified, resulting in a decrease in the residual lignin of 4.6% in the largest chip size. Improvements in the peroxide delignification process previously optimized by Yang et al. (2002) were achieved by altering substrate consistency, and the addition of peroxide stabilizers and chelants. Increasing consistency from 2 to 10% resulted in a decrease in the residual lignin content from 5.4% to less than 3% respectively. Additionally, stabilization (DTMPA) reduced the residual lignin content, after optimization a 40% decrease in lignin content is achievable, while maintaining glucose yield from enzymatic hydrolysis. Therefore, by optimizing the conditions it was possible to reduce the chemical (peroxide) loading by greater than 40%.

碩士
國立雲林科技大學
環境與安全衛生工程系
106
When polyester resin (PR) is manufactured on an industrial scale, the spreading of the dust cloud is a potential explosion hazard. The maximum explosion pressure and maximum rate of pressure rise were in the range 3.6 bar < Pmax (500) < 9.8 bar and 32 < (dP dt–1)max (500) < 356 bar s–1, respectively, which is more than that of sugar dust explosion. The explosion index Kst = V1/3 (dP dt–1)max was in the range 8.86 bar m s–1 < Kst (500) < 96.63 bar m s–1, which belongs to dust explosion class St-1. In addition, the results indicated that the explosion pressure can be significantly lessened with lower LOC. However, the inhibiting effect is not obvious at higher initial pressure. Therefore, the oxygen concentration must be considered as low as feasibly possible at a higher pressure to lessen the explosion hazards in production as well as handling process. Moreover, according to ANOVA analysis, the most significant factors for explosion intensity (Pmax) is dust concentration. The parameter should be prudently controlled during the storage, transportation, and manufacturing of PR dust.

碩士
國立雲林科技大學
環境與安全衛生工程系
104
In the chemical industrial processes, dust explosion is a critical hazard in numerous manufacturings and storage facilities. When the explosion calamity happened, life and property must be paid out with huge economic costs, and the reputation of corporation will deteriorate. For this reason, how to prevent accidents is a significant issue. On this research, we focused on the product of polyester resin and main materials with adipic acid (AA) and p-terephthalic acid (PTA). All of the parameters can be obtained by a variety of measuring equipment. In regards to the physical parameters, particle size analyzer and thermogravimetry can provide the particle size and peak temperature (Tp). Regarding of chemical parameters, minimum ignition energy analyzer and 20-L apparatus are representative instruments for the explosion coefficient. According to the results, particle size have high correlation about the minimum ignition energy tests. In the explosion parameter tests, not only the particle size but also chemical structure should be considered. Regarding the forecast burning velocity, probing its correlation with explosion parameters is a important topic. Therefore, building up a safety as well as complete protection mechanisms is a significant issue.

I vulcani in stato di attività persistente a condotto aperto spesso ospitano un’attività definita stromboliana. Questo stile di attività è caratterizzato da rilasci frequenti (intervalli da secondi a minuti) e impulsivi (della durata di alcuni secondi) di piroclasti e gas, dovuti alla risalita e allo scoppio di grosse bolle di gas (dette slug) vicino alla superficie della colonna di magma. Nel tempo, tali vulcani possono mostrare continui cambiamenti nell’evoluzione e nella migrazione delle proprie bocche attive, dalle quali si può osservare anche un comportamento altamente variabile dell’attività. Le origini di tale variabilità devono essere studiate a scale spaziali e temporali variabili. In una scala di anni/centinaia di metri, l’osservazione diretta della migrazione delle bocche nello spazio e nel tempo nei vulcani contraddistinti da più bocche è ancora limitata, e resta da capire la relazione tra questa attività variabile e il sistema di condotti superficiale. Su una scala di secondi/metri, molti autori si sono focalizzati sulla dinamica del rilascio di gas e sulle modalità di formazione dei piroclasti, finora trascurando ampiamente la dinamica di risalita dei piroclasti dalla profondità di rilascio, dove gli slug scoppiano, sino alla loro espulsione dalla bocca. Lo scopo del mio studio è la definizione delle relazioni tra i parametri fisici all’interno del condotto vulcanico e la loro influenza sulla modalità di espulsione dei piroclasti nelle eruzioni stromboliane, tenendo conto delle due scale sopramenzionate. Per raggiungere tale scopo ho adottato due metodologie separate ma complementari. La prima richiede la caratterizzazione delle eruzioni stromboliane in natura, indagando i cambiamenti temporali nella posizione delle bocche sulla terrazza craterica di Stromboli e i parametri di esplosione (durata e geometria del getto) usando i video delle telecamere di sorveglianza a infrarossi raccolti tra il 2005 e il 2009. I risultati di questa prima metodologia forniscono un database dettagliato dell’attività stromboliana normale a diverse scale temporali, oltre a consentire di delineare una gerarchia di profondità a cui il sistema di condotti superficiale controlla l’attività esplosiva entro le tre principali aree (cioè la nord-est, la centrale e la sud-ovest) che raggruppano più bocche vicine a Stromboli. Alla profondità più bassa, dove gli slug scoppiano, la forma della bocca e le dimensioni degli slug controllano i parametri di esplosione locali, mentre la ramificazione più in superficie dei condotti determina l’evoluzione delle bocche che esplodono simultaneamente o alternativamente. Al di sotto della profondità di scoppio degli slug, il sistema di condotti che alimenta ciascuna area di bocche controlla quale specifica bocca ospiterà le esplosioni e anche alcune caratteristiche generali di esplosione all’interno di queste aree. A questa profondità si suppone ci sia un collegamento tra l’area centrale e quella sudovest, come supportato da diverse osservazioni. Al livello più profondo, il sistema di condotti è comune a tutte le aree e imposta il tasso eruttivo globale del vulcano, bilanciandolo tra l’area nord-est e quella congiunta sud-ovest e centrale. Questo tipo di analisi può essere eseguito anche in altri sistemi persistenti contraddistinti da più bocche in tutto il mondo, fornendo deduzioni di base sulla geometria e la dinamica del loro sistema di condotti e sulla valutazione della pericolosità connessa. La seconda metodologia è dedicata alle simulazioni di getti gas-particelle per mezzo di esperimenti analogici in scala utilizzando uno shock-tube trasparente. Questo approccio è incentrato sull’effetto delle condizioni iniziali (cioè, pressione e volume del gas, posizione del campione, dimensione e quantità di particelle, geometria della bocca) sia sull’accelerazione delle particelle all’interno del condotto che sull’espulsione risultante dalla bocca. I risultati mostrano che la velocità massima delle particelle ha una correlazione positiva con l’energia iniziale e una correlazione negativa sia con la profondità del campione rispetto alla bocca che con la dimensione delle particelle. Inoltre, gli esperimenti mostrano tendenze di accelerazione e decelerazione delle particelle all’interno dello shock-tube che dipendono in modo variabile da alcune condizioni iniziali (cioè energia iniziale, profondità del campione e dimensione delle particelle) e influiscono sulla velocità massima delle particelle registrata all’uscita. Rispetto ai processi che si verificano durante le eruzioni esplosive a piccola scala, questi risultati aprono la strada a nuove potenziali deduzioni riguanti i processi che controllano la dinamica dei piroclasti. Le tendenze di accelerazione e decelerazione all’interno dei condotti influenzano i modelli correnti che correlano la velocità di espulsione dei piroclasti con la loro profondità di origine nel condotto vulcanico. Dimostro che le assunzioni del modello non sono più valide nei casi di bassa energia iniziale e un campione più profondo. Pertanto, è necessaria una revisione del modello che tenga conto anche di queste tendenze prima di applicarlo alle eruzioni reali. Questi risultati aprono la strada a numerosi scenari futuri. Ad esempio, ulteriori esperimenti possono chiarire meglio gli effetti dell’accoppiamento gas- particella, analizzare il ruolo di altri parametri sull’espulsione dei piroclasti (ad esempio il diametro del condotto) o studiare altri aspetti (ad esempio, i pennacchi vulcanici utilizzando particelle molto fini, o collisioni particella-particella e particelle-parete nel condotto).
Persistent, open-vent volcanoes frequently host Strombolian explosions. This style of activity is characterized by frequent (intervals of seconds to minutes) and impulsive (seconds- long) releases of pyroclasts and gases, due to the rise and burst of large gas bubbles (i.e., slugs) near the surface of the magma column. Over time, such volcanoes can show continuous changes in the evolution and migration of their active vents, from which also a highly variable behavior of the activity can be observed. The sources of such variability need being investigated at variable spatial and temporal scales. On a scale of years/hundred of meters, direct observation of space-time vent migration at multi-vent volcanoes is still limited, and the relationship between this variable activity and the shallow conduit system remains to be understood. On a scale of seconds/meters, many authors are focused on the dynamics of gas release and modes of pyroclasts formation, so far largely neglecting the ascent dynamics of pyroclasts from their release depth, where slugs burst, to their ejection from the vent. The aim of my study is the definition of the relationships between the physical parameters inside the volcanic conduit and their influence on the modes of pyroclast ejection in Strombolian explosions, accounting for the two scales abovementioned. To achieve this aim, I considered two separate yet complementary methodologies. The first one requires the characterization of Strombolian eruptions in nature investigating temporal changes in vent position at the crater terrace of Stromboli and explosion parameters (jet duration and geometry) using infrared surveillance camera videos collected between 2005 and 2009. Results by this first methodology provide a detailed database of normal Strombolian activity at different time-scales, as well as allowing one to outline a hierarchy of depths at which the shallow conduit system controls the explosive activity within the three main vent areas (i.e., south-west, central, and north-east) at Stromboli. At the shallowest depth, where slugs burst, vent shape and slug size control local explosion parameters, while shallower conduit branching determines the evolution of simultaneous or alternating twin vents. Below the depth of the slug burst, the conduit system feeding each vent area controls which specific vent will host the explosions and also some more general explosion features within a vent area. A link between the central and south-west vent areas is supposed at this depth, as supported by several observations. At the deepest level, the conduit system is common to all vent areas and sets the overall explosion rate of the volcano, balancing it between the north-east and the joint south-west and central vent areas. This kind of analysis may be performed also in other persistent multi-vent systems worldwide, providing basic inferences on geometry and dynamics of their conduit systems and on the hazard assessment. The second methodology is addressed on gas-particle jet simulations by means of scaled analogue experiments using a transparent shock-tube. This approach focuses on the effect of the initial source conditions (i.e., gas pressure and volume, sample position, size and amount of particles, vent geometry) both on the acceleration of the particles within the conduit and on the resulting ejection from the vent. Results show that maximum particle velocity has a strong positive correlation with initial energy and a weaker, negative correlation with both sample depth from the vent and particle size. Moreover, the experiments show trends of particle acceleration-deceleration in the shock-tube that variably depend on some initial conditions (i.e., initial energy, sample depth, and particle size) and influence particle maximum velocity recorded at the exit. When compared to processes occurring during low-scale explosive eruptions, these results open the way for potential, new inferences on the processes controlling the dynamics of pyroclasts. The acceleration-deceleration trends inside the conduits impact current models relating pyroclast ejection velocity with their source depth in the volcanic conduit. I show that, for a lower initial energy and a deeper sample, the model assumptions do not hold true anymore. Therefore, a model revision taking into account these trends is necessary before applying it to real eruptions. These results open the way to numerous future scenarios. Further experiments may, for instance, clarify, the effects of particle-gas coupling, analyze the role of other source parameters on pyroclast ejection (e.g., conduit diameter) and study other aspects (e.g., the volcanic plumes using very fine particles, or particle-particle and particle-wall collisions in the conduit).

碩士
中臺科技大學
安全與防災科技研究所
101
Runaway reaction caused by organic peroxides in the past years, which have induced fire or explosion accidents due to its instability characteristics in many countries. 1,1,-Di(tert-butylperoxy) cyclohexane (CH70) and 1,1,-Di-tert-butylperoxy-3,3,5-trimethylcyclohexane (TMCH) were two kinds of explosive materials applied in this study. CH70 and TMCH were extensively employed in relevent chemical industries for the polymerization of styrene and rubber, applied as the agent in the process of polymerization. In addition, we also applied the monoammonium phosphate (MAP) to mixed with the above-mentioned materials to test the extinguishing efficiency. In this study, thermal analysis was used to realize the explosive materials exothermic and endothermic phenomenon and decomposition process by differential scanning calorimetry (DSC). Results by this study indicated that reaction heat of CH70 and TMCH were high than 1,300 J/g and 1,200 J/g, separately. Inhibition reaction was very significantly, while CH70 mixed with MAP. Kinetic and safety parameters can be used in the manufacturing process for preventing the accident.

We address questions related to the parameterization of two distinct types of seismic sources: earthquakes and underground nuclear explosions. For earthquakes, we focus on the improvement of location parameters, latitude and longitude, using relative measurements of spatial cluster of events. For underground nuclear explosions, we focus on the seismic source model, especially with regard to the generation of surface waves. We develop a procedure to improve relative earthquake location estimates by fitting predicted differential travel times to those measured by cross-correlating Rayleigh- and Love-wave arrivals for multiple earthquakes recorded at common stations. Our procedure can be applied to populations of earthquakes with arbitrary source mechanisms because we mitigate the phase delay that results from surface-wave radiation patterns by making source corrections calculated from the source mechanism solutions published in the Global CMT Catalog. We demonstrate the effectiveness of this relocation procedure by first applying it to two suites of synthetic earthquakes. We then relocate real earthquakes in three separate regions: two ridge-transform systems and one subduction zone. In each scenario, relocated epicenters show a reduction in location uncertainty compared to initial single-event location estimates. We apply the relocation procedure on a larger scale to the seismicity of the Eltanin Fault System which is comprised of three large transform faults: the Heezen transform, the Tharp transform, and the Hollister transform. We examine the localization of seismicity in each transform, the locations of earthquakes with atypical source mechanisms, and the spatial extent of seismic rupture and repeating earthquakes in each transform. We show that improved relative location estimates, aligned with bathymetry, greatly reduces the localization of seismicity on each of the three transforms. We also show how improved location estimates enhance the ability to use earthquake locations to address geophysical questions such as the presence of atypical earthquakes and the nature of seismic rupture along an oceanic transform fault. We investigate the physical basis for the mb-MS discriminant, which relies on differences between amplitudes of body waves and surface waves. We analyze observations for 71 well-recorded underground nuclear tests that were conducted between 1977-1989 at the Balapan test site near Semipalatinsk, Kazakhstan in the former Soviet Union. We combine revised mb values and earlier long-period surface-wave results with a new source model, which allows the vertical and horizontal forces of the explosive source to be different. We introduce a scaling factor between vertical and horizontal forces in the explosion model, to reconcile differences between body wave and surface wave observations. We find that this parameter is well correlated with the scaled depth of burial for UNEs at this test site. We use the modified source model to estimate the scaled depth of burial for the 71 UNEs considered in this study.

Thesis (M.S.)--Michigan State University, 2005.
Includes bibliographical references (leaves 143-147). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Indiana University-Purdue University Indianapolis (IUPUI)
Ion mobility spectrometry is a powerful technique for the study related to molecule. The work of tow major applications are introduced in this paper. The first application is the optimization of parameters in CCS. The accurate calculation of the collision cross section for multiple molecules is a long-time interested topic in the research for substances detection in micro scale. No reliable analytical approach to calculate the collision cross section has been established to date. Different approaches rely on different mechanism will provide different results in significant extent. This work introduce a method for the determination of parameters in the Lennard Jones potential. Experimental data combined with numerical computation was the fundamental strategy during the optimization of the parameters. In the experiment, electrospray is used as the ion source of IMS while a nebulizer was utilized to electrify the aromatic compounds. New parameters show no less accuracy and equal efficiency while can explain the physical meaning of the collision more clearly. The second application is the trace detection of explosives with very low concentration. The detection of explosives is an important topic in security, while the detection will be difficult due to the low vapor pressure of explosives. In this work, two types of devices are designed for the trace detection of explosives at an extremely low concentration. TNT is selected as the explosives in the experiment. The experiment succeed to reach a sensitivity of 1 part per quintillion, and even find out a linear relationship between the logarithm of TNT concentration and TNT vapor pressure.

Tese de doutoramento em Engenharia Mecânica, na especialidade de Materiais Energéticos e Sistemas de Conversão de Energia, apresentada ao Departamento de Engenharia Mecânica da Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Neste trabalho é feita a simulação numérica do processo de decomposição térmica de um explosivo plástico de base RDX confinado num veículo de teste de escala laboratorial submetido a um cenário de incêndio, designado na literatura por cookoff, e do processo de deformação e rotura das paredes do veículo de teste devido à violência da reação do explosivo após ignição. O trabalho compreendeu quatro fases. Na primeira fase procedeu-se à determinação dos parâmetros termoquímicos e cinéticos dos reagentes e do explosivo plástico de base RDX, considerando diferentes composições até à adição de todos os reagentes, a partir do tratamento das curvas de DSC e TG para diferentes métodos de análise térmica. A segunda fase envolveu a determinação dos parâmetros da equação de estado JWL para descrever o comportamento hidrodinâmico dos produtos da reação do explosivo plástico em regime de detonação. A terceira e quarta fase compreenderam a simulação do processo de decomposição térmica do exp.losivo até à ignição e pós-ignição respetivamente, em cenários de slow e fast cookoff (SCO e FCO), tendo por base o programa de elementos finitos ABAQUS 2D. Os resultados mostraram que entre os parâmetros termoquímicos e cinéticos, a energia de ativação é o parâmetro que mais afeta os resultados do tempo, temperatura e decomposição mássica no momento de ignição. Variações até ±10 % nos valores do calor de reação, calor específico e condutividade térmica exercem pouca influência na alteração dos resultados. Na simulação numérica do cookoff do PBX RH8515, o modelo cinético de SB (m, n) por comparação com o modelo cinético JMA (m), conduziu a valores de tempo e de temperatura no instante de ignição mais próximos dos resultados experimentais tanto para SCO como para FCO. Em cenário de SCO a diferença relativamente ao valor da temperatura de ignição experimental foi inferior a 2,4 % enquanto para FCO foi inferior a 0,5 %. Para o tempo no instante da ignição as diferenças foram superiores, sendo de 15 % para SCO e de 6,3 % para FCO. O efeito dinâmico da reação de detonação do explosivo após ignição mostrou ser suficiente para deformar e romper a parede cilíndrica na zona central do veículo de teste.
In this work is carried out a numerical simulation of the thermal decomposition process of a plastic bonded explosive based on RDX restricted in a laboratory test vehicle, when submitted to a fire scenario, known in the literature as cookoff, and the deformation process and rupture of the walls of test vehicle due to the reaction violence of explosive after ignition. The work included four steps. The first step involved the calculation of the thermochemical and kinetic parameters of the reagents and the plastic bonded explosive based on RDX, considering different compositions until the addition of all reagents, from DSC and TG curves for different methods of thermal analysis. The second step was about the calculation of JWL equation of state parameters to describe the hydrodynamic behavior of the products of reaction under detonation regime. The third and fourth steps were regarding the numerical simulation of thermal decomposition process of the explosive until ignition and post-ignition respectively, in slow and fast cookoff scenarios, (SCO and FCO), based on the finite element program ABAQUS 2D. The results showed that among the thermochemical and kinetic parameters, the activation energy was the parameter that most affects the outcome of time, temperature and mass decomposition at ignition point. Variations up to ± 10 % in the values of the heat of reaction, specific heat capacity and thermal conductivity have little influence on changing results. In numerical simulation of cookoff PBX RH8515, the kinetic model SB (m, n) when compared with the kinetic model JMA (m) led to time and temperature values at ignition point closer to experimental results for both SCO and FCO scenarios. In SCO scenario the difference to experimental results of ignition temperature was less than 2,4 %, while for FCO was less than 0,5%. For time at ignition point differences were 15 % to SCO and 6,3 % to FCO. The dynamic effect of the detonation after ignition has proved to be sufficient for the deformation and rupture the cylindrical wall in the central zone of the test vehicle.

Title: Selected parameters of postural stability in elite sport dance group. Objectives: The aim of this study is to evaluate selected parameters of postural stability in elite sport dancers in Czech Republic during their preparatory period and to define the relation of postural stability to body composition, equality and ability of explosive strength production of lower limbs. Methods: The group of 10 elite sport dancers, composed of men (n=5, age=25,1±2,4 years, height=181,9±3,8 cm, weight=73,7±7,5 kg) and women (n=5, age=24±3,2 years, height=169,1±5,7 cm, weight=53,8±3,6 kg), was longitudinally observed during their preparatory period. At the beginning and on the top (national championship) postural stability, body composition and dynamic performance were evaluated. These following devices were used for testing: force plate FootScan (RScan International, Belgium), bioimpedance analyzer BIA 2000M (Datainput, Germany) and Tanita (Tanita Corporation, Japan), dynamometric force plates Kistler 8611 (Kistler, Switzerland). Results were evaluated by descriptive and inductive (paired t-test) statistics. Results: Results showed high similarity of followed selected parameters in elite sport dancers at the beginning and also at the top of preparatory period. Postural stability was slightly impaired, but...

Dissertação de Mestrado Integrado em Engenharia Mecânica apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra.
As operações de detonação submarinas têm sido, durante as últimas décadas, alvo de pesquisa e desenvolvimento das operações de detonação marítimas, incluindo testes de torpedo, bem como, em testes em piscinas para a medição de energia de detonação de explosivos industriais. O estudo dos geradores de demolição por carga submersa (WBWG) tiveram por base nestes conceitos. Com o presente trabalho pretendo apresentar o estudo do comportamento de WBWG, com base em dois tipos de recipientes de plástico com água (25 litros e 1000 litros), contendo no seu interior exactamente no centro um detonador dentro de uma carga explosiva cilíndrica. As cargas explosivas usadas foram uma emulsão de nitrato de amónio com fuel oil (ANFO) e cordão detonante (12 g/m) de pentrite (PETN). Muito resumidamente uma revisão bibliográfica foi realizada. As propriedades de detonação dos explosivos foram previstas utilizando um programa termoquímico, designado por THOR. Para a expansão dos produtos de detonação dos explosivos foi aplicado uma equação de estado JWL. Foi realizado uma revisão aos conceitos fundamentais desta equação e os seus coeficientes foram determinados e optimizados correlacionando as previsões do THOR e a equação de estado (EOS) JWL para a mínima diferença através de uma função quadrática auxiliar. Por forma a calcular os coeficientes de JWL um novo método foi usado. Este baseia-se na evolução das curvas adiabáticas e isentrópicas obtidas pelo THOR, utilizando uma função do Microsoft Excel ® Solver, assumindo algumas suposições para o coeficiente Grüneisen (a partir do exponencial da curva adiabática; do exponencial da curva isentrópica para um volume adimensional limite; do exponencial da curva isentrópica para todos os valores da expansão, e por último; deduzido por Handley, 2011). Os melhores resultados obtidos foram pela utilização do coeficiente Grüneisen do exponencial da curva isentrópica para todos os valores da expansão, onde para a emulsão de ANFO e para PETN. As dimensões e o design da configuração de “WBWG” experimental foram apresentadas, juntamente com a descrição de uma experiência de detonação tipo utilizando 3 g de PETN (detonador No.8 mais 2.4 g de cordão detonante de PETN). Foi realizada uma simulação a 2D e 3D de “WBWG” usando o programa Autodyn para um contentor de metro cúbico cheio de água (1000 litros) para ambos os explosivos. Os resultados obtidos mostram a possibilidade de ter este tipo de cargas explosivas sem a destruição do “WBWG” contentor. Uma vez que, os níveis de pressão na água, perto das paredes plásticas, sob a maior carga admissível, ronda os 6 MPa. Foi sempre possível observar a deformação elástica das paredes do contentor, as reflecções do choque subaquático, alterando a sua forma cúbica original para uma espiral transiente. Adicionalmente os procedimentos executados para o THOR, para o Microsoft Excel ® Solver e para a interface do programa de simulação Autodyn “material input data” foram apresentados.
Underwater blasting operations have been, during last decades, subject of research and development of maritime blasting operations, including torpedo studies. Aquarium tests, for the measurement of blasting energy of industrial explosives, are based in studies of confined underwater blast wave generators (WBWG). The current work present the study of the behavior of WBWG, based in two different water plastic containers (25 litres and 1000 litres), having in the center a detonator inside a cylindrical explosive charge. The explosive charges used were ammonium nitrate with fuel oil (ANFO) emulsion and pentaerythritol tetranitrate (PETN) detonating cords (12 g/m). Summarily the theoretical background was review. The explosives detonation properties were predicted using a thermochemical computer code, named THOR. For the expansion of the detonation products of the explosives was applied JWL EoS. JWL fundamentals were review and his parameters were determined and optimized correlating THOR predictions and JWL EoS to a minimum difference with an auxiliary quadratic function. In order to calculate the JWL coefficients, a new numerical method was used. It was based in the evolution of adiabate and isentrope curves, obtained by THOR code, using a function of the Microsoft Excel ® Solver, assuming a few assumptions for Grüneisen coefficient (from the exponential of the adiabatic curve; from the exponential of the isentrope curve at a limit adimensional volume; from the exponential of the total expansion of isentrope curve and, at last; deducted from Handley, 2011). The best results were obtained using the Grüneisen coefficient from the exponential of the total expansion of isentrope curve, which were for ANFO emulsion and for PETN. The dimensions and design configurations of the experimental WBWG were presented and also a blast type experiment for 3 g of PETN (detonator No. 8 plus 2.4 g charge of PETN detonation cord) was described. Autodyn 2D and 3D simulations of WBWG were performed using a cubic meter water container (1000 litres) for both explosive. The obtained results show the possibility of having these explosive charges without destruction of WBWG containers. Since water pressure levels, close to plastic walls, under maximum admissible charges, are closed to 6 MPa. It was always observed the elastic deformation of containers wall, under the water shock reflections, changing from its original cubic shape to a transient spherical one. Additionally the execution procedures of THOR code, Microsoft Excel ® Solver and the interface of Autodyn simulations material input data was presented.