VCU Neuroguard: Multi-person Radiation Shielding Device

The objective of the VCU Neuroguard project was to design and build a device to shield all medical personnel in Operating Room-33, at MCV Hospital, from radiation during neurological procedures that utilize a Siemens Artis Zee biplane X-ray machine. The initial goal was to develop a fully working prototype but due to monetary reasons this goal was adjusted to a working prototype minus the radiation shielding materials. There were many requirements for the VCU Neuroguard set forth by the customer and by the team, including the ability to shield all the medical staff in the room, the ability for them to work without it getting in the way, sterilization, visibility, the ability to move with the operating table, and weight restrictions. In the beginning, the team observed procedures, researched existing devices, studied the Xray machine and operating room set up. The team then conducted various materials research, utilized SolidWorks®, and radiation shielding calculations to complete the design. The final prototype (seen below) is a free standing barrier constructed of 80/20® aluminum framing and surrogate radiation shielding materials that attaches to and moves in conjunction with the operating table. Further work on this project will include the implementation of functional radiation shielding materials and development of a permanent mechanism to attach the device to the operating table as well as adding adaptability for use in other operating environments. A fully functional Neuroguard will protect medical professionals and alleviate the use of cumbersome personal protective equipment.https://scholarscompass.vcu.edu/capstone/1140/thumbnail.jp

Aircraft measurements of microphysical properties of subvisible cirrus in the tropical tropopause layer

International audienceSubvisible cirrus (SVC) clouds are often observed within the tropical tropopause layer (TTL). Some studies suggest that SVC has a significant impact on the earth radiation budget. The Costa Rica Aura Validation Experiment (CR-AVE) sponsored by the National Aeronautics and Space Administration (NASA) took place near San Jose, Costa Rica from 14 January?15 February 2006. The NASA WB-57F sampled SVC in the TTL from ?75°C to ?90°C with an improved set of cloud particle probes. The first digital images of ice particles in the TTL are compared with replicator images of ice particles collected in 1973 by a WB-57F in the TTL. The newer measurements reveal larger particles, on the order of 100 ?m compared with <50 ?m from the earlier measurements, and also different particle shapes. The 1973 particles were mainly columnar and trigonal, whereas the newer measurements are quasi-spherical and hexagonal plates. The WB-57F also measured very high water vapor contents with some instruments, up to 4 ppmv, and aerosols with mixed organics and sulfates. It is unknown whether these ambient conditions were present in the 1973 studies, and whether such conditions have an influence on particle shape and the development of the large particles. A companion paper (Jensen et al., 2008) presents crystal growth calculations that suggest that the high water vapor measurements are required to grow ice particles to the observed sizes of 100 ?m and larger

Western Culture and the Spread of Serial Murder

Serial murders may have occurred in non-Western cultures, like Japan, South Africa, and Pakistan, before the introduction of Western ideals. These murders would have gone unnoticed and unreported if the populace did not know or understand the significant differences between serial murder and other types of violence and death. The people and authorities in non-Western cultures would not know of these differences unless they were made known to them or if they started to investigate the murders more closely. People from Western cultures who move to non-Western areas or communicate with non-Western natives may introduce these differences and familiarize the native population with the distinctions between serial murder and other types of murder, violence, and death. There is a correlation between the amount of Western cultural influences in non-Western nations and the increase of serial killers, but the question of causation is yet to be determined

Changing pH in the Surface Ocean

In 1896, Arrhenius provided the first roughly quantitative sense of the plausible magnitude of human-induced changes in the concentration of CO2 in the atmosphere. Since then, all chemists could be aware that increasing CO2 in the atmosphere must lead to increasing amounts in the ocean and a corresponding increase in acidity. For a long time, however, no one appears to have thought much about this latter consequence, probably because the likely effects were small and were, in any case, rather troublesome to calculate. It was only in 1909 that Sørensen proposed the concept of the pH scale. The negligible level of concern about the effect of CO2 on Earth\u27s heat balance was not much affected by the work of Callendar (1938), who argued that the increasing concentrations in the atmosphere could be observed and would be significant. The radiative balance calculations of Plass (1956), published in Tellus, began to influence those who read such journals, and the beginnings of the Keeling curve brought widespread attention to the increasing atmospheric CO2 concentration

The effect of temperature on denitrification kinetics and biological excess phosphorus removal in nutrient removal activated sludge systems in temperate climates (12°C - 20°C)

Filamentous bulking in nutrient (N & P) removal activated sludge systems is a problem of considerable magnitude - three quarters of 45 plants surveyed were found to have bulking sludges to the extent that sludge settleability (DSVI) was adversely affected. If filamentous organism proliferation could be controlled and thereby sludge settleability improved to below DSVI of 100 ml/g, then with provision for factors such as additional aeration capacity, between 50% and 7 5% more wastewater could be treated in existing nutrient removing activated sludge plants. Anoxic-aerobic (AA) or low F/M filaments appear to proliferate in activated sludge plants that incorporate biological nitrogen removal. From earlier research, Casey et al. (1992a) showed that the cause for AA filament proliferation lay in the denitrification behaviour of the N removal systems. They hypothesized that filamentous and floe-forming organisms have different denitrification behaviour - the former reducing nitrate only as far as nitrite whereas the latter reducing nitrate all the way to nitrogen gas via the denitrification intermediates nitrite, nitric oxide (NO) and nitrous oxide (N₂O). If nitrate and nitrite removal to nitrogen gas is not complete in the anoxic reactor, then, when conditions become aerobic, the accumulated denitrification intermediates, in particular NO, inhibit oxygen uptake in the floc-formers. The filaments do not experience this inhibition because by reducing nitrate only to nitrite, no denitrification intermediates accumulate in their cytoplasmic membrane and consequently they can successfully compete against the floe-formers and proliferate in the N removal systems. If denitrification is complete, no residual intracellular denitrification intermediates remain in the floc-formers. Therefore, when conditions become aerobic, the floc-formers are not inhibited in their oxygen uptake and can successfully compete against the filamentous organisms which cause the bulking

PIRANHA: an engine for a methodology of detecting covert communication via image-based steganography

In current cutting-edge steganalysis research, model-building and machine learning has been utilized to detect steganography. However, these models are computationally and cognitively cumbersome, and are specifically and exactly targeted to attack one and only one type of steganography. The model built and utilized in this thesis has shown capability in detecting a class or family of steganography, while also demonstrating that it is viable to construct a minimalist model for steganalysis. The notion of detecting steganographic primitives or families is one that has not been discussed in literature, and would serve well as a first-pass steganographic detection methodology. The model built here serves this end well, and it must be kept in mind that the model presented is posited to work as a front-end broad-pass filter for some of the more computationally advanced and directed stganalytic algorithms currently in use. This thesis attempts to convey a view of steganography and steganalysis in a manner more utilitarian and immediately useful to everyday scenarios. This is vastly different from a good many publications that treat the topic as one relegated only to cloak-and-dagger information passing. The subsequent view of steganography as primarily a communications tool useable by petty information brokers and the like directs the text and helps ensure that the notion of steganography as a digital dead-drop box is abandoned in favor of a more grounded approach. As such, the model presented underperforms specialized models that have been presented in current literature, but also makes use of a large image sample space (747 images) as well as images that are contextually diverse and representative of those seen in wide use. In future applications by either law-enforcement or corporate officials, it is hoped that the model presented in this thesis can aid in rapid and targeted responses without causing undue strain upon an eventual human operator. As such, a design constraint that was utilized for this research favored a False Negative as opposed to a False Positive - this methodology helps to ensure that, in the event of an alert, it is worthwhile to apply a more directed attack against the flagged image

Investigation of the many oxidation states of vanadium for the purpose of making a rechargeable battery

The demand of large energy storage systems continues to increase with the development and improvement of renewable energy sources such as wind turbines and photovoltaic arrays. Electrochemical storage, or battery storage, such as lead-acid, lithium-ion, sodium based, and redox flow batteries (RFB), can be implemented for large scale energy storage. One of the most popular RFB is the all-vanadium redox flow cell (VRFB), which has a longer longevity, greater stability, and lower cost compared to other battery systems. The single metal system employs V2+/V3+ and VO 2+/VO2+ as half cells for the flow battery. But, there are still various phenomena associated with the vanadium redox flow cell that are not fully understood. Also, the limitations of this system need to be reduced in order to fully supply the demand.||To better understand the VRFB, the multiple oxidation states of vanadium were investigated using multiple methods. Ultraviolet visible spectroscopy (UV-VIS) and rotated disk electrode cyclic voltammetry (RDE CV) were used to characterize the different oxidation states. Electrochemical Impedance Spectroscopy (EIS) was employed to investigate the redox couples used in the VRFB as well as a constructed VRFB. While exploring the various oxidation states a precipitate was formed. The identity of the precipitate was determined using energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction spectroscopy (XRD)

Urban creek restoration, Adobe Creek, Santa Clara County, California.

Increased urban development has encroached upon and impacted Adobe Creek by constricting the route and volume of flow to predetermined corridors, often irrespective of the original creek morphology. The headwaters geology and human influences have contributed to the creek\u27s disequilibrium. Channelization and instream modifications have segmented the creek system limiting the transfer of changes through the system. Located east of the San Andreas fault (SAF) in the Franciscan Complex, Adobe Creek flows from the eastern foothills of the Santa Cruz Mountains and empties into the San Francisco Bay