Syftet med den här studien har varit att presentera ett underlag till konstruktion av en bogvisirmodell som skall kunna gå att styras med en PLC-enhet och som kan användas i undervisningssyfte för PLC-programmering. Underlaget förankrades i verkligheten genom en fältstudie och en litteraturstudie. Fältstudien inspirerade utformandet av bogvisirmodellen och bidrog med värdefull insikt i hur bogvisir fungerar. Litteraturstudien har bestått av två delar där en del har fokuserat på att undersöka regelverk som berör konstruktion av bogvisir och den andra delen har studerat hur två katastrofer, som involverade bogöppningar, har påverkat reglerna som rör bogvisir i SOLAS-konventionen. Litteraturstudien resulterade i två sammanställningar. En sammanställning av de regler ifrån SOLAS-konventionen, Transportstyrelsen och DNV-GL som reglerar konstruktion av bogvisir och en sammanställning av hur två katastrofer som involverar bogöppningar har påverkat reglerna i SOLAS-konventionen. Materialet ifrån fältstudien och litteraturstudien har använts till att utveckla ett underlag för hur en bogvisirmodell som styrs av en PLC-enhet, och som skall gå att använda i undervisningssyfte, kan konstrueras. / The purpose of this paper is to present design material that can be used to build a bow visor model which is controlled by a PLC unit and can be utilized as a tool when educating students in PLC programming. A field study and a literature study have been conducted to make the bow visor model realistic. The field study has inspired the design of the bow visor model and contributed valuable insight into the workings of a bow visor. The literature study consists of two parts where one part focused on studying regulations that regulates the design of a bow visor and the other part focused on studying how two disasters that involve bow doors have impacted the regulation in the SOLAS Convention. The literature study resulted in two compilations. One compilation consists of regulations from the SOLAS Convention, the Swedish Transportation Agency and DNV-GL regulating the design of bow visors and the other compilation consists of changes in the SOLAS Conventions regulations that are a direct result of two disasters that involve bow doors. The result of the field study and the literature study have been used to develop the design material for how a bow visor model, that is controlled by a PLC unit and can be used for educational purposes, can be built.

This thesis explores Lucien Capet's bowing technique and identifies connections to contemporary violin bowing practices. It includes a developed biography of Capet; a review of the Capet treatise; a historical analysis linking Capet's bowing technique back to his predecessor Baillot and forward to the present day; a detailed comparative analysis that determines Capet's pedagogical connections to Ivan Galamian and Simon Fischer; and an examination of the ramifications of the results including the the finding that Capet's technique is a viable and important component to developing refined contemporary bowing technique.

This thesis reports on the investigations of resistive-capacitive (RC) loaded bow-tie antennas with special emphasis on impulse ground penetrating radar applications. Impulse radiation for ground penetrating radar is a challenging research topic because of the unique problem arising from impulse radiation: late-time ringing, which usually masks the important echo signals from the targets. While resistive loading is a common solution for eliminating late-time ringing, use of resistive loading typically sacrifices the radiation efficiency. In this thesis, a resistive-capacitive loading technique is investigated for a circular bow-tie antenna in the attempt to reduce/suppress the late-time ringing as well as to maintain a relatively high radiation efficiency. To implement the system, a microstrip differentiator, which converts a monopulse into a Gaussian-like monocycle to be used as input impulse, is presented. Further, specially designed coplanar waveguide/coplanar strip (CPW/CPS) baluns embedded with Chebyshev transformers of characteristic impedance up to 120 have been constructed and tested. To evaluate the system, instead of using the conventional peak voltage value of the radiated waveform, average radiated energy, average ringing energy, relative radiation efficiency and relative ringing efficiency are utilized and these metrics are easily established using low-cost low-sensitivity probes. Measurement results show that the RC-loading scheme is functioning as expected and the impulse system as a whole is capable of reducing the late-time ringing energy to 50% while maintaining average radiation energy as 83% when compared with capacitive loading cases. / October 2006

Thesis (M.S.)--University of North Texas, May, 2009. / Title from title page display. Includes bibliographical references.

We use particle and magnetic field data from the Ion and Neutral Camera (INCA) and the magnetometer (MAG) onboard Cassini to detect and examine an energetic particle event that occurred upstream from the Saturnian bow shock during DOY 229/2007. The energetic (>100 keV) O+ ions are observed only when the Interplanetary Magnetic Field (IMF) connects the spacecraft with the planetary bow shock. We provide strong evidence showing the magnetospheric origin of the observed ions: (1) We detect singly ionized oxygen (O+) which is not resident of the solar wind, (2) the particle pitch angle distribution indicates that the ions travel along the field line connecting the spacecraft to the bow shock and (3) the ion intensity increases are observed only during the periods of magnetic connection to the bow shock. Our results show that the Saturnian dayside magnetosphere is not as sealed as thought to be, but can -under certain circumstances- allow high energy magnetospheric plasma to leak into the nearby solar wind and further in space.

This thesis reports on the investigations of resistive-capacitive (RC) loaded bow-tie antennas with special emphasis on impulse ground penetrating radar applications. Impulse radiation for ground penetrating radar is a challenging research topic because of the unique problem arising from impulse radiation: late-time ringing, which usually masks the important echo signals from the targets. While resistive loading is a common solution for eliminating late-time ringing, use of resistive loading typically sacrifices the radiation efficiency. In this thesis, a resistive-capacitive loading technique is investigated for a circular bow-tie antenna in the attempt to reduce/suppress the late-time ringing as well as to maintain a relatively high radiation efficiency. To implement the system, a microstrip differentiator, which converts a monopulse into a Gaussian-like monocycle to be used as input impulse, is presented. Further, specially designed coplanar waveguide/coplanar strip (CPW/CPS) baluns embedded with Chebyshev transformers of characteristic impedance up to 120 have been constructed and tested. To evaluate the system, instead of using the conventional peak voltage value of the radiated waveform, average radiated energy, average ringing energy, relative radiation efficiency and relative ringing efficiency are utilized and these metrics are easily established using low-cost low-sensitivity probes. Measurement results show that the RC-loading scheme is functioning as expected and the impulse system as a whole is capable of reducing the late-time ringing energy to 50% while maintaining average radiation energy as 83% when compared with capacitive loading cases.

This thesis reports on the investigations of resistive-capacitive (RC) loaded bow-tie antennas with special emphasis on impulse ground penetrating radar applications. Impulse radiation for ground penetrating radar is a challenging research topic because of the unique problem arising from impulse radiation: late-time ringing, which usually masks the important echo signals from the targets. While resistive loading is a common solution for eliminating late-time ringing, use of resistive loading typically sacrifices the radiation efficiency. In this thesis, a resistive-capacitive loading technique is investigated for a circular bow-tie antenna in the attempt to reduce/suppress the late-time ringing as well as to maintain a relatively high radiation efficiency. To implement the system, a microstrip differentiator, which converts a monopulse into a Gaussian-like monocycle to be used as input impulse, is presented. Further, specially designed coplanar waveguide/coplanar strip (CPW/CPS) baluns embedded with Chebyshev transformers of characteristic impedance up to 120 have been constructed and tested. To evaluate the system, instead of using the conventional peak voltage value of the radiated waveform, average radiated energy, average ringing energy, relative radiation efficiency and relative ringing efficiency are utilized and these metrics are easily established using low-cost low-sensitivity probes. Measurement results show that the RC-loading scheme is functioning as expected and the impulse system as a whole is capable of reducing the late-time ringing energy to 50% while maintaining average radiation energy as 83% when compared with capacitive loading cases.

Thesis (M.A. in anthropology)--Washington State University, May 2010. / Title from PDF title page (viewed on Apr. 30, 2010). "Department of Anthropology ." Includes bibliographical references (p. 144-156).

The role of warfare in Maya society is much debated, but it seems to have been widespread during the Late Postclassic (A.D. 1250-1519) and Protohistoric (A.D. 1519-1696) periods. This study investigates the manner in which the Maya engaged in warfare during these centuries by reviewing archaeological data on Maya warfare and Spanish accounts of their contacts with the Maya of central Petén, Guatemala. The bow and arrow, which were not used during the Classic period, are "area weapons" that can be used at a distance, and appear to have changed the character and tactics of warfare in the Postclassic period and in Maya defensive interactions with the Spaniards. Eighty small projectile points from the sites of Zacpetén and Ixlú were analyzed. These triangular points, believed to have tipped arrows, were made of chert and obsidian and varied particularly in the placement and number of notches, in the shape of their bases, and in the amount of retouch. Notching and basal variation do not clearly relate to differing ethno-political units in the central Petén Postclassic, to functional areas of the sites, or to ballistic performance. Variations in amount of retouch may indicate that the points were made quickly.

abstract: An exhaustive parameter study involving 133 dynamic crystallization experiments was conducted, to investigate the validity of the planetary embryo bow shock model by testing whether the cooling rates predicted by this model are consistent with the most dominant chondrule texture, porphyritic. Results show that using coarse-grained precursors and heating durations ≤ 5 minutes at peak temperature, porphyritic textures can be reproduced at cooling rates ≤ 600 K/hr, rates consistent with planetary embryo bow shocks. Porphyritic textures were found to be commonly associated with skeletal growth, which compares favorably to features in natural chondrules from Queen Alexandra Range 97008 analyzed, which show similar skeletal features. It is concluded that the experimentally reproduced porphyritic textures are consistent with those of natural chondrules. This work shows heating duration is a major determinant of chondrule texture and the work further constrains this parameter by measuring the rate of chemical dissolution of relict grains. The results provide a robust, independent constraint that porphyritic chondrules were heated at their peak temperatures for ≤ 10 minutes. This is also consistent with heating by bow shocks. The planetary embryo bow shock model therefore remains a viable chondrule mechanism for the formation of the vast majority of chondrules, and the results presented here therefore strongly suggest that large planetary embryos were present and on eccentric orbits during the first few million years of the Solar System’s history. / Dissertation/Thesis / Masters Thesis Geological Sciences 2018