The U.S. Army has recently developed cutting edge designs for gun barrels, projectiles, and propellants that require testing. This includes measuring the internal pressure during fire. There are concerns with the current method of drilling to mount pressure transducers near the breech and chamber of the gun barrel where pressure is highest. An alternative, non-intrusive strain measurement method is introduced and discussed in the present work. This focuses on determining the feasibility and accuracy of relating tangential strain along the sidewall of a gun barrel to the drastic internal pressure rise created during combustion. A transient structural, numerical modal was created using ANSYS of a 155 mm gun barrel. The pressure gradient was derived using a method outline in IBHVG2 (Interior Ballistics of High Velocity Guns, version 2), and the model was validated using published experimental tangential strain testing data from a gun of the same caliber. The model was used to demonstrate the ideal location for strain measurement along the sidewall of the chamber. Furthermore, three different pressure ranges were simulated in the model. The behavior of the tangential strain in each case indicates a similar trend to the internal pressure rise and has oscillation due to a dominant frequency of the barrel. A method to predict internal pressure from external tangential strain was developed. The internal pressure predicted is within 4% of the pressure applied in the model. A sensitivity study was performed to determine the primary factors affecting tangential strain. The study specifically looked at material properties and geometry of the gun barrel. The thickness and elastic modulus of the gun barrel were determined the most relevant. Overall, the present work helps to understand tangential strain behavior on the sidewall of a large caliber gun barrel and provides preliminary work to establish an accurate prediction of internal pressure from external tangential strain. / Master of Science / Innovative technology for large gun systems require testing to evaluate safety and performance. The most recent designs from the U.S. Army for long range artillery require higher pressures. Currently, large gun barrels are drilled to mount pressure transducers for internal pressure testing, but the new generation of weapons require a way to measure internal pressure of the gun without introducing these high stress locations. External strain offers a means to measure displacement of the barrel caused by the internal pressure change with minimal alteration to the gun barrel. The present work focuses on modelling a large gun barrel using finite elements to understand the behavior of strain on the external surface due to internal pressure during fire. Measurements were taken near the chamber of the gun barrel model. The strain behavior is comprised of two components, a linear change due to a pressure increase and vibrations introduced due to the sharp pressure increase over a short amount of time. Three cases were evaluated at different pressure ranges and a method was developed to predict internal pressure from the tangential strain with a maximum error of 4% for all cases studied. The model also indicates that the strain results are most sensitive to a change in thickness and the elastic modulus of the gun barrel material.

Thesis advisor: Zine Magubane / Thesis advisor: Nora Gross / The career of a high guidance counselor can range from topics of teenage drama, college decisions, and the annual class selection meeting; however, what are they to do when gun violence is currently the number 1 cause of death for children 1-19 (Everytown, 2022). Legally, students are expected to spend 49% or 180 days of the year within the walls of a school for at least 6 hours, in turn, the institution of schools has become a place for making friends, connections, and experiences, whether they be good or bad (Pew, 2023). When gun violence plagues the walls of a school, support generally falls to counselors to help students navigate their emotions and grief. However, schools and counselors do not necessarily have the resources or training to provide that support. Particularly in under-resourced urban neighborhoods, counselors may already be spread too thin in their responsibilities, worsening the effects of gun violence and unresolved grief. Further, some counselors cannot understand their students' lived experiences because the differences in their racial, financial, and geographical upbringing promote a culture of misunderstanding and inability to solve root issues with cultural competency (Englert-Copeland, 2019). In this study, we aim to examine how schools and counselors support students impacted by gun violence, focusing on two major metropolitan areas on the East Coast: Boston and Philadelphia. The problem the project is addressing is the way schools situate themselves in helping students’ grief, given the increase in adolescent gun violence throughout the United States. Philadelphia has seen a particular increase in gun violence over the past decade (Philadelphia Police Department, 2022). Per the Philadelphia Office of the Controller, they found that 10.9% of all gun deaths within the city were people under 19 years of age for the 2023 year to date (2023). Everytown Research found that in “Massachusetts, the rate of gun deaths increased 16% from 2010 to 2019, compared to a 17% increase nationwide; gun homicides increased 26%, compared to a 13% increase and 26% increase nationwide, respectively” (Everytown, 2021). On the other hand, the city of Boston has seen a decrease in the gun violence rate over the past few years (Massachusetts Department of Public Health, 2022) While Boston does have one of the lowest gun violence rates in the world, students there experience grief over losing loved ones from neighborhood gun violence. The state noted that gun violence deaths are the 3rd-leading cause of death among children and teens in Massachusetts (2021). Through the research, we hope to identify best practices and strategies for schools and counselors to better support students impacted by gun violence and reduce the negative effects of unresolved grief. By examining the experiences of students in these two urban areas, we believe that we can contribute to the broader conversation about how to address this critical issue in schools and communities across the country. / Thesis (BA) — Boston College, 2024. / Submitted to: Boston College. Morrissey School of Arts and Sciences. / Discipline: Sociology. / Discipline: Departmental Honors.

L’imagerie préclinique dans le domaine de la cancérologie est en plein essor. Elle permet grâce à des modèles animaux représentatifs de cancers humains de comprendre les mécanismes de développement des pathologies et d’évaluer l’efficacité thérapeutique d’un nouveau traitement. Le principal objectif de ce travail a été de développer deux modèles orthotopiques de cancer (pancréas et colon) et d’évaluer des traitements de références ainsi qu’une nouvelle stratégie thérapeutique par plasma froid fibré appelée Plasma Gun. Les 2 modèles de cancers développés ont montré une bonne représentativité vis-à-vis des cancers humains, avec l’apparition de métastases à distance et la présence de zones hypoxiques. Le 5-fluorouracile pour le modèle orthotopique de carcinome colorectal HCT116-luc et la gemcitabine pour le modèle d’adénocarcinome pancréatique MIA PaCa2-luc ont induit à faible dose des effets discrets pouvant être mis en évidence grâce aux modalités d’imageries mises en oeuvre. Après validation de nos démarches expérimentales une nouvelle stratégie thérapeutique, le Plasma Gun, a été évaluée et a montré des effets significatifs sur l’inhibition de la croissance tumorale. Le second objectif de ma thèse a été de mettre en oeuvre des outils pour l’induction et la caractérisation des métastases osseuses ainsi que pour l’imagerie haute résolution de la vascularisation. D’une part, les métastases osseuses obtenues par injection de cellules PC3M-luc en intracardiaque ont été évaluées et quantifiées grâce à différentes modalités d’imagerie (bioluminescence, scintigraphie et scanner X). D’autre part, la réalisation d’une imagerie haute résolution de la vascularisation a été possible grâce à la technique de casting qui permet de recréer la structure 3D de l’architecture vasculaire suite à l’injection d’une résine dans la circulation. Les développements réalisés lors de cette thèse ont ainsi permis d’apporter des outils pour l’évaluation préclinique de nouvelles thérapies anticancéreuses. / Preclinical imaging in oncology is booming. It allows, using representative animal models of human cancers, to understand the mechanisms of development of pathologies and to assess the therapeutic efficiency of a new treatment. The main objective of this work was to develop two orthotopic models of cancer (pancreas and colon) and to assess on them the reference treatments as well as a new therapeutic strategy by non thermal plasma so called Plasma Gun. The two cancer models developed showed good representation in relation to human cancers, with the appearance of distant metastases and hypoxia. 5-fluorouracil for the HCT116-luc orthotopic model of colorectal carcinoma and gemcitabine for the MIA PaCa2-luc pancreatic adenocarcinoma model, have induced discrete effects at low dose wich can be detected thanks imaging modalities. After validation of our experimental steps, a new therapeutic strategy, Plasma Gun was evaluated and showed significant effects on tumor growth inhibition. The second objective was to carry out tools for the induction and the characterization of bone metastases and for high resolution imaging of the vasculature. On the one hand, bone metastases obtained by injection of PC3M-luc cells intracardially, was evaluated and quantified with different imaging modalities (bioluminescence, scintigraphy and Computed Tomography). And the other hand, the achievement of a high resolution imaging of vascularization, was possible by the casting method that restores the 3D structure of the vascular architecture following injection of a resin in the circulation.

South Korea experienced extraordinary economic growth in the period from 1960 to 1990. From a backward economy in the 1950’s, South Korea has been transformed into an urban industrial society with high levels of managerial and technical competence within governments, corporations and local communities. This dissertation examines Korea’s remarkable economic growth from the theoretical level and the local level. It presents an integrative framework, based on a review of the conventional theories and perspectives of modernization, dependency, world-system, and the New International Division of Labor (NIDL). The research documents the central government’s industrial policies and its collaboration with the corporate sector in the policy practice. It then analyzes economic, social, and environmental impacts of the two partners on local communities. The impacts in the industrial city of Ulsan are compared to the conditions in the traditional city of Kyungju. This case study includes survey research, which was designed to obtain public opinion on a wide variety of issues, from three different groups: government officials, corporate managers, and citizens. The research leads to the following conclusions. In contrast to Neo-Marxist arguments, well coordinated actions between the government and the private sector have a positive effect on industrial development, notwithstanding some constraining forces from the external world. Industrial growth in Korea did create a better Quality of Life for the general public. It supports some elements of the world-systems urban theory, such as emphasis on internal and external forces, internal dynamics within a developing country, and the relationships among world core, national centers, and smaller cities. Writings by Peter Dickens, Armstrong and McGee and Hagen Koo are shown to be useful for this kind of research. The thesis does not support the thread of the traditional dependency theory and the NIDL thesis. Industrialization in Korea did not marginalize the general public. Rather it improved the Quality of Life for the public, which is supported by the opinion survey indicating that more than three quarters of the sample respondents see that their Quality of Life has improved. Rapid industrialization in Korea caused social and environmental problems especially in the industrial cities. The survey result indicates that ninety four percent of the respondents from Ulsan regard environmental pollution a ‘very’ serious problem for the city, while the equivalent number for Kyungju was twelve percent. The survey result also shows that the public is now concerned more with social issues, such as a clean environment and a more equal distribution of wealth, than economic growth. As people’s awareness has expanded substantially to include elements of a better Quality of Life, both the local government and citizens agree there are problems with the conventional approach to industrial promotion. Although the strong views are held, neither the national nor local government have developed coherent policies to deal with this new phenomenon. The national government has expanded the roles of provincial and municipal governments in policy development, and this will include the election of local mayors and governors in 1995. It will provide a forum for better definition of the problem and more opportunities for their resolution.

This Thesis covers work conducted to understand the mechanisms underpinning the operation of the electrothermal-chemical gun. The initial formation of plasma from electrically exploding wires, through to the development of plasma venting from the capillary and interacting with a densely packed energetic propellant bed is included. The prime purpose of the work has been the development and validation of computer codes designed for the predictive modelling of the elect rothe rmal-ch em ical (ETC) gun. Two main discussions in this Thesis are: a proposed electrically insulating vapour barrier located around condensed exploding conductors and the deposition of metallic vapour resulting in a high energy flux to the surface of propellant, leading to propellant ignition. The vapour barrier hypothesis is important in a number of fields where the passage of current through condensed material or through plasma is significant. The importance may arise from the need to disrupt the fragments by applying strong magnetic fields (as in the disruption of metallic shaped charge jets); in the requirement to generate a metallic vapour efficiently from electrically exploding wires (as per ETC ignition systems); or in the necessity to re-use the condensed material after a discharge (as with lightning divertor strips). The ignition by metallic vapour deposition hypothesis relies on the transfer of latent heat during condensation. It is important for the efficient transfer of energy from an exploded wire (or other such metallic vapour generating device) to the surface of energetic material. This flux is obtained far more efficiently through condensation than from radiative energy transfer, because the energy required to evaporate copper is far less than that required to heat it to temperatures at which significant radiative flux would be emitted

Gun violence in New Orleans has grown exponentially over the years. As a society we often forget to reflect on how gun violence effects the youth in our communities. Local members of the community in New Orleans have decided to come together to form organizations that can produce better outcomes for the youth in the New Orleans area, two of those organizations being Son of A Saint and the Youth Empowerment Project. Both of these organizations have started the journey to decreasing the amount of gun violence in the city.

This Thesis covers work conducted to understand the mechanisms underpinning the operation of the electrothermal-chemical gun. The initial formation of plasma from electrically exploding wires, through to the development of plasma venting from the capillary and interacting with a densely packed energetic propellant bed is included. The prime purpose of the work has been the development and validation of computer codes designed for the predictive modelling of the elect rothe rmal-ch em ical (ETC) gun. Two main discussions in this Thesis are: a proposed electrically insulating vapour barrier located around condensed exploding conductors and the deposition of metallic vapour resulting in a high energy flux to the surface of propellant, leading to propellant ignition. The vapour barrier hypothesis is important in a number of fields where the passage of current through condensed material or through plasma is significant. The importance may arise from the need to disrupt the fragments by applying strong magnetic fields (as in the disruption of metallic shaped charge jets); in the requirement to generate a metallic vapour efficiently from electrically exploding wires (as per ETC ignition systems); or in the necessity to re-use the condensed material after a discharge (as with lightning divertor strips). The ignition by metallic vapour deposition hypothesis relies on the transfer of latent heat during condensation. It is important for the efficient transfer of energy from an exploded wire (or other such metallic vapour generating device) to the surface of energetic material. This flux is obtained far more efficiently through condensation than from radiative energy transfer, because the energy required to evaporate copper is far less than that required to heat it to temperatures at which significant radiative flux would be emitted

South Korea experienced extraordinary economic growth in the period from 1960 to 1990. From a backward economy in the 1950’s, South Korea has been transformed into an urban industrial society with high levels of managerial and technical competence within governments, corporations and local communities. This dissertation examines Korea’s remarkable economic growth from the theoretical level and the local level. It presents an integrative framework, based on a review of the conventional theories and perspectives of modernization, dependency, world-system, and the New International Division of Labor (NIDL). The research documents the central government’s industrial policies and its collaboration with the corporate sector in the policy practice. It then analyzes economic, social, and environmental impacts of the two partners on local communities. The impacts in the industrial city of Ulsan are compared to the conditions in the traditional city of Kyungju. This case study includes survey research, which was designed to obtain public opinion on a wide variety of issues, from three different groups: government officials, corporate managers, and citizens. The research leads to the following conclusions. In contrast to Neo-Marxist arguments, well coordinated actions between the government and the private sector have a positive effect on industrial development, notwithstanding some constraining forces from the external world. Industrial growth in Korea did create a better Quality of Life for the general public. It supports some elements of the world-systems urban theory, such as emphasis on internal and external forces, internal dynamics within a developing country, and the relationships among world core, national centers, and smaller cities. Writings by Peter Dickens, Armstrong and McGee and Hagen Koo are shown to be useful for this kind of research. The thesis does not support the thread of the traditional dependency theory and the NIDL thesis. Industrialization in Korea did not marginalize the general public. Rather it improved the Quality of Life for the public, which is supported by the opinion survey indicating that more than three quarters of the sample respondents see that their Quality of Life has improved. Rapid industrialization in Korea caused social and environmental problems especially in the industrial cities. The survey result indicates that ninety four percent of the respondents from Ulsan regard environmental pollution a ‘very’ serious problem for the city, while the equivalent number for Kyungju was twelve percent. The survey result also shows that the public is now concerned more with social issues, such as a clean environment and a more equal distribution of wealth, than economic growth. As people’s awareness has expanded substantially to include elements of a better Quality of Life, both the local government and citizens agree there are problems with the conventional approach to industrial promotion. Although the strong views are held, neither the national nor local government have developed coherent policies to deal with this new phenomenon. The national government has expanded the roles of provincial and municipal governments in policy development, and this will include the election of local mayors and governors in 1995. It will provide a forum for better definition of the problem and more opportunities for their resolution. / Graduate and Postdoctoral Studies / Graduate

This thesis is focused for manufacturing of a gun barrels and his issues. In thesis is involved introducing of the company Česká zbrojovka a.s. and definition of hand fired guns. Written analysis present the state of a technological process and describe an individual phase of manufacturing of the semi-finished product of gun barrel and the following conclusion of a complex manufacturing of a gun barrel from the semi-finished product to the stand, when the gun barrel installed into the gun is. Subsequently are suggested possibly solutions of manufacturing rationalization and possibly purchasing of a new modern CNC machines. In the end is accomplished a technical-economic evaluation, which compares existing and suggesting of the technology.

No description available.