Stability of Metal Oxide Nanoparticles: Solution Chemistry and Mechanical Effects

Abstract

Glacial Delineation and Ice Retreat on Pico de Orizaba, Mexico Alexander E Colby and Blake Weissling, Geology Pico de Orizaba, a dormant stratovolcano at the eastern end of the Trans-Mexican Volcanic Belt at approximately 19 degrees of latitude and the third largest peak in North America (5636 m), hosts what is likely the last significant tropical zone glacier (Jamapa Glacier) in the Northern Hemisphere. Not since the International Geophysical Year of 1957-58 has Pico's glacial environment been studied with any focused effort, perhaps due to the difficulty of the approach and general inaccesablilty. High altitudes, steep slopes, and hazardous weather make studying Pico de Orizaba that much more difficult. As are most glaciers around the world, the Jamapa Glacier is retreating, with a remarkable loss of ice in the past 2 decades. The rate and pattern of retreat is important to understanding climate change forcing as well as understanding environmental and water supply impacts to a substantial human population who live along the base of the volcano. Through the use of satellite imagery (LandSat, ASTER, IKONOS), legacy hand-drawn maps, aerial photographs, and first-hand accounts from climber's expeditions, a reasonably accurate map of almost 60 years of glacial retreat has been produced. Legacy hand-drawn maps of the ice edge, that pre-date the satellite era, did not fit perfectly with modern images when layered in ArcGIS. Oblique perspectives in Google Earth and various aerial and surface-based photographs of the mountain were used to help fit the ice edge to the actual topography. Dated pictures posted on image and video hosting websites (Flickr, Photobucket, Pict) were useful in providing more angles of the mountain. Internet blogs and published articles/books based on climbing expeditions (recreational and scientific) to Pico de Orizaba provide first-hand accounts of the mountain. These first-hand accounts of expeditions to Pico de Orizaba describe conditions present on the mountain. Some climber reports give details on the ice edge as well as describing geologic features that restrict where glacial ice can form and flow. Different types of satellite data and satellite imaging programs (Envi 4.8) were also used. The disparity of satellite image pixel resolution (from 1 m IKONOS to 60 m LandSat) was addressed using various imagery analysis tools (eg. edge detection convolution filters and pixel unmixing) in order to delineate an approximate ice edge for the respective image date. The final map shows the nature of ice edge retreat on Pico de Orizaba from 1945 up until the present (Feb 2011). Submitted for Poster Presentation (I am comfortable with an Oral Presentation if needed) Flood Fatalities in Colorado Andres Munoz, Civil Engineering This study reviewed information related to the events that lead to flood fatalities in Colorado in the past 51 years. Information on these event and the flood fatality victims was obtained from the National Climatic Data Center (NCDC). All the information is collected using NCDC Storm Data reports. The data will be including; date, time, location, flood event, gender, and age. The total study will be including a detailed description of the flood event involving fatalities, such as vehicle involvement and what exactly happened. All the information from the data and detailed description will be collected in an excel spreadsheet, along with different graphs and tables to summarize events by month, time of occurrence, gender, area, vehicle involvement, and location. From 1959 to 2009 there is a total of 189 fatalities due to flood events. Colorado ranked sixth in the nation from flood fatalities. With one event causing more than half of that total in the month of July of 1976, making up 69 percent of the total. There are 43 fatalities caused by drowning, 15 being killed, and 131 unspecified. All fatalities came during the summer months of May to August, with May recording the fewest with 3 and July having the most with 153. 22 different counties recorded a flood fatality with Larimer having the most with 141 and 9 other counties tied with the fewest of 1. Submitted for Poster Presentation. Analysis of Lake Level and Temperature Variation in the Great Salt Lake using ICESat, MODIS, and In-Situ Data Anthony J Arricale, Geology, University of Texas San Antonio, San Antonio, TX Hongjie Xie, Geology, University of Texas San Antonio, San Antonio, TX John D Bolten, Hydrological Sciences, NASA GSFC, Greenbelt, MD Guoqing Zhang, School of Earth Science and Resources, China University of Geosciences, Beijing, China Many of today’s lakes are without in-situ gauges to measure lake level or lake water temperature due to their remote locations. Retrieving this data from individual remote lakes and comparing them is important for investigating changes in climate, anthropological, or watershed changes in an area. Today remote sensing equipment is being used to gather data for areas that have no previous in-situ data. It is important to check the reliability of the remote sensing data by investigating lakes that have previous in-situ data and comparing both data sets. This study utilizes remote sensing data from the Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud, and Land Elevation Satellite (ICESat) and data from the Moderate Resolution Imaging Spectrometer (MODIS) onboard the Aqua and Terra satellites. Global Land Surface Altimetry Data (GLA14) from GLAS is compared with in-situ lake level measurements for the Great Salt Lake (GSL) from 2003 to 2009 to check the reliability of the instrument. Both data sets revealed a decreasing trend in lake level with an r2 value of 0.88 between the ICESat and in-situ data. Thermal imagery from MODIS included 818 (1028) images from the Aqua (Terra) satellite from 2002 to 2011 (2000 to 2011). The images from both satellites are separated by 8 days and have a spatial resolution of 1km. These thermal images were used to calculate the surface water temperature (SWT) of the Great Salt Lake north and south of the railroad causeway which divides the lake in half. After analyzing the data it is evident that the shallower north half of the lake has a higher SWT in the summer and cooler SWT in the winter than the south half by 1 Co. The average monthly SWT and in-situ air temperatures for the GSL are compared with each other and from 2002 to 2010 there is a decreasing trend in air temperatures resulting in a decreasing SWT trend for both Terra and Aqua data sets. There is great potential for the use of satellites to measure certain remote lake characteristics in place of in-situ measurements. This study validates that idea by showing that the data satellites provide are reliable because of their similarity to in-situ measurements. Submitted for poster presentation Seasonal changes in albedo and frost coverage in the Martian crater Louth Ben Cardenas, Hongjie Xie, Geology The study of Martian ice is a critical component in understanding Mars in general; the ice may hold clues to Mars' past climate and the search for life, and to the ultimate goal of human settlement and terraforming. This case study focuses on the Louth crater (70.1 N, 103.5 E), the southernmost Martian crater in the northern hemisphere which holds a body of ice all year long. High resolution photographs from the HiRISE camera on the Mars Reconnaissance Orbiter (MRO) have been used to support previous conceptual models of sublimation/deposition and seasonal albedo change of the ice mound in the Louth crater. The CTX context camera, along with models of the crater's geometry and the positions of incoming sunlight, have been used to determine cause of preferential sublimation in certain areas of the crater; in particular, to determine why the southern wall holds frost much longer than the rest of the crater floor and walls. HiRISE images needed to be converted to show I/F, or the fraction of light reflected to incoming light. This is corrected for sun and satellite angles, though not for atmospheric disturbances. On Mars, these disturbances are negligible, so I/F can be considered a true albedo. I/F values of the center mound were averaged from all photographs and graphed in excel to show the I/F change through time. Geometer’s Sketch Pad was used to create models of the crater and how sunlight hits the crater area, dependent on time of year. These models provided information on the maximum sun angle at a certain time of year, the angle needed to expose the southern wall, the hours spent in daylight, and more. The I/F results appear to agree with the conceptual model of albedo change. The fourphases of the model are visible when the data is observed in I/F vs time, although the phases occur earlier in the year than the model suggests. Actual values of albedo could not directly be compared, however, because HiRISE offers a limited number of bands compared to the previously used TES images. The southern wall of the crater was found to receive about 30% less sunlight than the rest of the crater floor, which must be enough of a difference to preserve frost longer. It was also found that when an area hits about 60% sunlight/day, frost tends to begin visibly disappearing. This could hold some information for creating a future model relating sun exposure, surface temperature, and ice thickness. Performance of Microbial Fuel Cells Using a Bee-Hive Structure Anode and a Comparative Analysis to Carbon Fiber Brush Electrodes Crystal Gonzalez, Routing Pei, Civil and Environmental Engineering Each day, on average a person uses approximately 14,000 kW·h per capita of energy. In today’s modern society everything revolves around electricity specifically and renewing such energy by using microbial fuel cells will soon become implemented on large scales in treatment plants. In sum a microbial fuel cell (MFC) is a device that converts organic material into electricity by a catalytic reaction of bacteria or any microorganism. Working with bacteria provides an inexpensive yet effective source of electricity which has positive effects on our environment as well. The initial idea in this project was to determine if the bee hive anode produced a higher voltage or increased power generation from the MFCs than the carbon brush electrode. While simultaneously recovering more energy into electricity. The method used in this project was developed by creating bee hive anode structures, by varies percentages of graphite, clay and carbon and selecting the most durable samples. After some successful structures of anode were formed, testing would proceed; where bacterial can be uses as MFC to transfer the electrons originating from the microbial absorption. The electron then flow from the anode to the cathode, and generate the current and voltage to make electricity. The bacteria get its energy by removal of electrons from the organic material and give those electrons to any accepting substance such as oxygen or nitrate. Once the configuration ran every 30min, a slightly greater voltage can be seen with the created anode structure. This slight increase in the voltage led to the structure of the anode. More because the anode had multiple pores which allowed the bacteria to move freely versus the carbon fiber brush which had a limited surface area. ------Poster Presentation Innovative Beam-to-Column Joint Design of Fixed Moment Resisting Steel Frames for Seismic Areas Francisco J Cantu, Mijia Yang Civil Engineering To attenuate the seismic response of stiff and low ductile steel frame configurations, existing and standard beam-to-column joints have been reengineered. In this paper, several innovative joint designs are suggested to optimize the resistance of structures under dynamic forces. The target joints discussed in this paper is a typical beam-to-column connection. Though rigid steel joints have been known to somewhat resist dynamic forces, failures have occurred due to low ductility, therefore the use of high ductile joint systems have been adopted. One of the reoccurring problems with the use of rigid joints is that joint members such as beams and columns shift much of their stress directly to the stiffest part of the structure, in this case, the rigid joints. At that point the bolts and welding tend to experience more stress, causing the joints to decouple. With the possibility of producing a domino effect the structure is more likely to fall on the ground. Thanks to modern design procedures, the uses of higher ductile joint systems have proven to have the capability to decouple stiffness and yield strength and reach ductility quicker, therefore demanding less elasticity from the beam and column members. However, the use of these systems could prove to take more time in the construction process and are more expensive than the conventional rigid frame system. Since our goal is to dissipate more energy coming from the ground, joints with higher ductility are needed for higher magnitude earthquakes. Even though, the amount of energy transmitted from ground to the structure depends on the interaction between the foundation and structure itself, that interaction will not be discussed here. In this paper, we focus on the innovative design for higher ductility and energy dissipations. In order to increase the ductility and energy dissipation, we will add special elements, such as elastomeric pads, special cut beam areas and additional stiffeners to change the joint failure modes. To analyze the effect that elastomeric materials, reduced beam area connections and the bolted stiffened extended end plate connections had, a standard W24x146.5 steel beam and column is being considered. The joint systems for the members will connect flange to flange, and consist of two standard W24x146, 5 foot steel beam sections. The area of this section is approximately equal to 43.0 inches squared, and consists of common structural steel that has a Young’s Modulus of 29,000.00 ksi, density of .284 pounds per inches cubed, a poisons ratio of 0.25, and a yield stress of 36 ksi. The bolts and seats connecting the two sections will be made up of the same steel properties as the beam sections, and will have a nominal diameter of one inch. The behavior of the joints will be analyzed through finite element analysis software called Abaqus. The seat joint connection, analyzed at a 30 kip cyclic load condition, proved more beneficial when using the elastomeric paddings. The padded joint experiences significantly less stress at the column middle section to where the beam is applied, and it is also evident that stress on the web portion of the beam where the seat is located in nearly nonexistent under the same loading conditions. The model consisted of a 20 step cyclic loading process that simulates an idealized earthquake event. It can be noted, given the same applied cyclic load of 30 kips perpendicular to the ground, that the displacement of the padded joint is greater than that of the control joint. With the sacrifice of some deflection one can conclude that the area under the curve increases. Mathematically, the area under the force vs. displacement curve is also known to be energy. As the area under the curve increases more energy is absorbed by the system and therefore decreases the chance of failure of the frames themselves. Understanding that seismic conditions can vary, it is important to be able to provide a flexible system that can dissipate energy in multiple directions. In the case of the joint studied, elastomeric pads were useful in the absorption of energy, therefore reducing the amount of stress induced on to the steel members themselves. To the RBS and the BSEEP design, multiple cases were run in Abaqus in order to better visualize the changes between their control joint and their modified joints. These connections were both ran 3 times, first at a 30 kips cyclic load level, second at a 50 kips load level, and lastly at a 100 kip load level. Because of their semi rigid nature, these joints undergo the same cyclic type of loading; prove to be a lot more resistant than the conventional seat joint. In fact the bolted web connection without RBS alone proved to not even reach elasticity until a larger than 50 kip load was applied. Notably the energy absorbed by the system starts to grow as the elements in the system start to yield. In this system plasticity is reached somewhere between 50 and 100 kips. As seen in a plotted graph the RBS section is actually encompasses more area therefore providing more ductility. The RBS, unlike the BWJ, yields at the beam. In this case, the Reduced Beam Section actually acts as a hinge that would cause the system to yield at given locations before causing any real harmful structural damage to the system. Similarly the BSEEP graph shows that the system itself outperforms a conventional system. The energy sustained by the system was simply too much to hold together for the conventional joint. However when stiffeners were added the stiffness of the joint is increased and energy consumed was a lot less, therefore it would be able to sustain the whole cyclic loading of 20 times steps of the applied reversal moment.

1 Figure or Table

Cite this paper

@inproceedings{Lambert2011StabilityOM, title={Stability of Metal Oxide Nanoparticles: Solution Chemistry and Mechanical Effects}, author={Lance L. Lambert and Xiaofeng Liu and Hatim O. Sharif and Hongjie Xie and Marvin Lopez}, year={2011} }