A simple modification to a standard increment borer handle is described that enhances use of the borer in situations where obstructions to the rotation of a normal handle prevents utilization of the full length of the borer. The modification, informally called the ‘‘Quad-B’’ (Brown’s bent boomerang borer handle), involves bending both sides of the handle to ~35–40° angles. Some potential uses of the modified handle are described.

Master of Science / Department of Biological & Agricultural Engineering / Ajay Sharda / Moisture measurement is critical when baling alfalfa into round bales for feed. If alfalfa is too wet or too dry, it can greatly diminish the alfalfa crop’s feed quality and cause economic loss to producers. Therefore, monitoring of alfalfa moisture content while baling is critical for producers to maintain hay quality and maximize profits. Currently, there are several different types of moisture sensing technologies available for round balers. But, concerns exist regarding their accuracy and repeatability during hay baling. Therefore, objectives of this project are to 1) Establish a protocol for coring methodology to assess the variation of moisture within a round alfalfa hay bale, and 2) Compare and contrast sensing accuracy and repeatability of different hay moisture sensing technologies. A coring methodology was established to determine the average moisture within a round bale based upon the way a sensor in a round baler chamber would determine the bale moisture; by looking at the moisture contents along the round bale diameter. This method was then compared with the more traditional method of using radial cores only to determine the whole bale moisture content. A sensor testing stand was developed to perform comparative testing between the sensors on the same alfalfa hay bale and collect core samples of material immediately after it was formed. Six commercially available moisture sensors were selected to measure moisture at four pre-determined locations on hay bales. After the sensor measurements, core samples were extracted from the exact same locations to determine actual moisture using oven-drying method. The moisture measurements were conducted during three growth stages and bales were formed with three approximate moisture contents of 10%, 15% and 20%. Six different cuts of alfalfa of the same variety were used to capture all the measurements. A seventh cut was also performed for moisture measurements with the alfalfa baled at 15% and the same growth stage, but different baler compression cylinder pressures (250, 400, and 800psi). Actual moisture content was across different sampling locations were compared to understand moisture distribution and establish coring protocol. Sensor and oven-dried measurements were compared to determine accuracy and repeatability of sensing technologies. Results showed that sensors and oven-dried measurement varied for all the sensors for every growth stage and baling moisture levels, with one sensor exhibiting lowest variability in its readings. The comparison identified the most accurate and reliable sensor among the ones currently available. A second year of testing was also conducted to validate the research from the first year of testing. Future research needs to be conducted to identify correlation between the testing stand readings and actual hay baler moisture sensor readings.

This project included the following goals: 1. To review and assess the geomorphology and lake morphometry of Mountain Lake, Giles County, Virginia with regard to its age and origin. This included production of an updated bathymetric map of Mountain Lake using Sonar imaging of the lake bottom. 2. To evaluate present trophic conditions in the lake waters. This analysis included the first-reported nutrient conditions for input streams to the lake and rainwater. 3. To collect representative "modern" bottom sediment samples and to analyze these sediment samples for sedimentological characteristics, diatoms , and terrestrial pollen. This analysis focussed on present environmental conditions in the lake, and the determination of modern diatom thanatocommunities. 4. To collect complete bottom sediment cores from the lake. Coring was done using a diver-assisted manual coring device designed specifically for this project. 5. To analyze Mountain Lake sediment cores for sedimentology, age determination, and temporal differences in sediment characteristics, diatoms and pollen. This analysis focussed on interpretation and documentation of environmental changes through the lake's history. Primary discharge from the lake presently occurs through a leaky subterranean pathway associated with the deepest, crevice-like portion of the lake. This discharge results in the crevice drain not filling shut with sediment despite its location within the lowest portion of the lake. The lake structure, crevice, and subterranean drain are associated with a regional lineation feature represented in part by the path of Salt Pond Drain and a small input stream ("I-4") to the lake. Initial damming was caused by downdrop of overlying rock. The damming is not complete, and the rate of discharge through time is controlled, in part, by regional tectonic events and by a balance of hydrologic conditions and sedimentation factors. The present lake is generally oligotrophic in nature, with phosphorus representing the major limiting nutrient. Rainfall presently represents the largest source of nutrient to the lake. Present diatom flora in Mountain Lake includes 66 individual taxa, representing 25 genera. Of these, 12 forms or species have not been reported in Virginia inland waters prior to this project. The diatoms reflect the oligotrophic and circumneutral nature of the lake. At least seven diatom thanatocommunities can be defined in the lake, based on taxa, delineated by depth and nutrient conditions. The ratio metric of planktonic to littoral diatoms can be used to estimate past water depths in the lake from bottom sediment. An orange clay layer at 5 cm from the modern sediment/water interface represents human intervention in lake history, namely the hotel and road building in the early 20th Century. The age of the lake is greater than 6000 years. Specific 14C from sediment produced dates of 1860 +100, 4220 +50 and 6160 +70 bp. Within this interval, at least 6 extended periods of low or empty lake level occurred (at approximately 100, 400, 900, 1200, 1800, and 4200 yrs bp). Several of these low intervals are likely to correspond with cool dry conditions co-incident with solar minima events. When the lake has been low or empty, it has tended to develop Sphagnum bog conditions with the low lake surrounded by open or wooded meadows. Terrestrial flora surrounding the lake appears to have remained relatively similar through 6100 years, although red spruce originally accompanied hemlock. / Ph. D.

The mechanical properties of the cancellous bone in the laboratory rat animal model are of great interest to the research community for the evaluation of treatments for osteoporosis. Cancellous bone responds rapidly and dramatically to disuse, various pathologies, nutritional deficiencies, and hormonal deficiencies and hence is often a primary focus in animal studies. Previous methods for evaluating the mechanical properties of cancellous bone in rat test specimens included both cortical and cancellous bone. This thesis introduces a new method to core cancellous specimens using a diamond wire saw in concert with specially designed fixtures. This method has been termed Isolated Cancellous Coring (ICC). The location and the geometry of the cored specimens were determined based on uCT analysis. The isolated cancellous specimens were subjected to uni-axial compression testing to evaluate the mechanical properties. Furthermore, the new method is evaluated by directly applying it to a study investigating the effects of estrogen replacement therapy in post-menopausal osteoporosis as simulated by the ovariectomized rat model. The results show that the ICC method can be applied to bone specimens with a large range in density and micro-architecture parameters. The compression testing of the isolated cancellous specimens provides a sensitive indicator of the effects of osteoporosis and treatment on the mechanical properties of the cancellous bone in the distal rat femur. Also, the results indicate a possible discordant relationship between bone mineral density and bone strength with respect to estrogen treatment. Power law regressions show that approximately 50% of the variation in ultimate strength can be accounted for with bone mineral density and the percent of bone volume per total volume.

Understanding the deep biosphere is of great commercial and scientific interest and will contri-bute to increased knowledge of the environment. If environmentally relevant results are to be ob-tained the precondition to achieve genuine findings is research in pristine habitat as close as pos-sible to those encountered in-situ. Therefore benthic conditions of sediment structure and gas hydrates, temperature, pressure and bio-geochemistry have to be maintained during the sequences of sampling, retrieval, transfer, sto-rage and downstream analysis. At the Technische Universität Berlin (TUB) the Pressurized Core Sub-Sampling and Extrusion System (PRESS) was developed in the EU project HYACE/HYACINTH. It enables well-defined sectioning and transfer of drilled pressure-cores [obtained by HYACE Rotary Corer (HRC) and Fugro Pressure Corer (FPC)] into transportation and investigation chambers. Coupled with DeepIsoBUG (University Cardiff, John Parkes) it allows sub-sampling and incubation of coaxial core-sections to examine high-pressure adapted bacteria or remote biogeochemical processes in defined research conditions of the laboratory; all sterile, anaerobic and without depressurisation. Appraisals of successful PRESS deployments in the Gulf of Mexico, on IODP Expedition 311 and as part of the NGHP expedition 01 demonstrate the general concept to be feasible and useful. Aided by Deutsche Forschungsgemeinschaft (DFG) TUB is currently working on concepts to downscale the system in order to reduce logistical and financial expenses and, likewise, to enlarge its implementation by requiring less operating space. Redesigning the cutting mechanism shall simultaneously adjust the system to harder cores (e.g., ICDP). Novel transportation chambers for processed sub-samples intend to make the system more attractive for a broad spectrum of users and reduce their interdependence.

In February 2007, the U.S. Department of Energy, BP Exploration (Alaska), Inc., and the U.S. Geological Survey conducted an extensive data collection effort at the "Mount Elbert #1" gas hydrates stratigraphic test well on the Alaska North Slope (ANS). The 22-day field program acquired significant gas hydrate-bearing reservoir data, including a full suite of open-hole well logs, over 500 feet of continuous core, and open-hole formation pressure response tests. Hole conditions, and therefore log data quality, were excellent due largely to the use of chilled oilbased drilling fluids. The logging program confirmed the existence of approximately 30 m of gashydrate saturated, fine-grained sand reservoir. Gas hydrate saturations were observed to range from 60% to 75% largely as a function of reservoir quality. Continuous wire-line coring operations (the first conducted on the ANS) achieved 85% recovery through 153 meters of section, providing more than 250 subsamples for analysis. The "Mount Elbert" data collection program culminated with open-hole tests of reservoir flow and pressure responses, as well as gas and water sample collection, using Schlumberger's Modular Formation Dynamics Tester (MDT) wireline tool. Four such tests, ranging from six to twelve hours duration, were conducted. This field program demonstrated the ability to safely and efficiently conduct a research-level openhole data acquisition program in shallow, sub-permafrost sediments. The program also demonstrated the soundness of the program's pre-drill gas hydrate characterization methods and increased confidence in gas hydrate resource assessment methodologies for the ANS.

This report aimed to investigate how chlorophyll-concentrations (Chl-a) in the water column and varved sediments were affected by changes in air temperature and precipitation and consequently how climate change will affect the sedimentation and productivity in boreal aquatic ecosystems. VRS (visible-reflectance-spectroscopy) was used to asses Chl-a and its derivates in sediment trap samples between 2002-2021 and in a series of freeze cores (1979-2021) from lake Nylandssjön, with annually laminated sediments. In order to evaluate how weather and climate change affected the sedimentation and productivity in the lake the results were compared with meteorological data from SMHI (Swedish Meteorological and Hydrological Institute) and Chl-a data from seperate depths in the water column. The results indicate that the majority of the yearly sedimentation occur either in May or June, where a higher cumulative amount of precipitation in May lead to a higher sedimentation rate in May (r=0,49; p=0,03). The amount of precipitation in spring also had a significant impact on the primary production in spring and summer (r=0,59; p=0,01; r=0,73; p=0,002). Water column Chl-a and spectrally inferred Chl-a in sediments show similar trends in concentrations with deeper water sampling, however, water column Chl-a displayed significant differences in values between various depths (p=0,0004). Consequently, climate change will much likely increase the productivity of boreal aquatic ecosystems within years and the amount of sedimentation that occurs between years due to higher temperatures. An increased amount of precipitation will also enhance the primary productivity and the transportation of allochthonous- and minerogenic material to the lake.

Les carottes de glace sont un fantastique outil d'étude du climat de notre planète. Récemment, le projet européen EPICA (European Project for Ice Coring in Antarctica) a permis d'extraire une carotte au Dôme Concordia en Antarctique (75◦06′ S; 123◦21′E). Les premières études montrent que les 740000 dernières années de notre histoire climatique y sont enregistrées. Dans ce manuscrit est présentée une étude de l'évolution de la microstructure (réseau de joints de grain) le long de la carotte de Dôme Concordia. Dans une premiére partie, nous nous concentrons sur l'évolution de la taille moyenne des grains qui présente de fortes variations synchrones avec les transitions climatiques. L'analyse des paramètres de la distribution de taille ainsi que les corrélations entre taille de grain moyenne et contenu en impuretès montrent que les particules de poussière ralentissent considérablement la croissance normale au cours des périodes Glaciaires, expliquant ainsi les variations observées. Le développement puis l'utilisation d'un modèle en champ moyen d'évolution de la taille de grain confirme quantitativement ce résultat et nous permet d'examiner le rôle des bulles, des clathrates et de la recristallisation par rotation sur la taille moyenne des grains. La géométrie de la microstructure est également le révélateur de la déformation subie par les couches de glace. Utilisant une technique d'analyse initialement développée pour l'étude du champ de déformation dans les mousses et adaptée au cas de la glace, il est apparu que nos mesures sont en contradiction avec deux des hypothèses généralement admises sur l'écoulement de la glace à un dôme : (i) le cisaillement n'est pas nul et sa valeur augmente avec la profondeur, (ii) la déformation verticale n'est pas homogène (certaines couches s'amincissent plus rapidement que leurs voisines). Les modèles de datation classiquement utilisés en glaciologie utilisent ces hypothèses, ce qui soulève quelques questions quant à leur validité. Nous nous sommes alors interrogès sur l'impact des hétérogénéités de déformation verticale sur la datation et tout particulièrement sur l'estimation de la durée d'évènements brefs.

In 1995, the U.S. Geological Survey made the first systematic assessment of the in-place natural gas hydrate resources of the United States. That study suggested that the amount of gas in the gas hydrate accumulations of northern Alaska probably exceeds the volume of known conventional gas resources on the North Slope. Researchers have long speculated that gas hydrates could eventually be a commercial resource yet technical and economic hurdles have historically made gas hydrate development a distant goal rather than a near-term possibility. This view began to change over the past five years with the realization that this unconventional resource could be developed in conjunction with conventional gas fields. The most significant development was gas hydrate production testing conducted at the Mallik site in Canada’s Mackenzie Delta in 2002. The Mallik 2002 Gas Hydrate Production Research Well Program yielded the first modern, fully integrated field study and production test of a natural gas hydrate accumulation. More recently, BP Exploration (Alaska) Inc. with the U.S. Department of Energy and the U.S. Geological Survey have successfully cored, logged, and tested a gas hydrate accumulation on the North Slope of Alaska know as the Mount Elbert Prospect. The Mallik 2002 project along with the Mount Elbert effort has for the first time allowed the rational assessment of the production response of a gas hydrate accumulation.

abstract: The volume of end-of-life photovoltaic (PV) modules is increasing as the global PV market increases, and the global PV waste streams are expected to reach 250,000 metric tons by the end of 2020. If the recycling processes are not in place, there would be 60 million tons of end-of-life PV modules lying in the landfills by 2050, that may not become a not-so-sustainable way of sourcing energy since all PV modules could contain certain amount of toxic substances. Currently in the United States, PV modules are categorized as general waste and can be disposed in landfills. However, potential leaching of toxic chemicals and materials, if any, from broken end-of-life modules may pose health or environmental risks. There is no standard procedure to remove samples from PV modules for chemical toxicity testing in the Toxicity Characteristic Leaching Procedure (TCLP) laboratories as per EPA 1311 standard. The main objective of this thesis is to develop an unbiased sampling approach for the TCLP testing of PV modules. The TCLP testing was concentrated only for the laminate part of the modules, as they are already existing recycling technologies for the frame and junction box components of PV modules. Four different sample removal methods have been applied to the laminates of five different module manufacturers: coring approach, cell-cut approach, strip-cut approach, and hybrid approach. These removed samples were sent to two different TCLP laboratories, and TCLP results were tested for repeatability within a lab and reproducibility between the labs. The pros and cons of each sample removal method have been explored and the influence of sample removal methods on the variability of TCLP results has been discussed. To reduce the variability of TCLP results to an acceptable level, additional improvements in the coring approach, the best of the four tested options, are still needed. / Dissertation/Thesis / Masters Thesis Engineering 2018