QUESTIONS: Do successional trajectories in plant diversity, heterogeneity and dominance respond differently to ungulate exclusion in unmanaged forests vs managed forests that are thinned and burned? Is vegetation in recently thinned and burned stands more sensitive to changes in the grazing regime? LOCATION: Northeast OR, USA. METHODS: We evaluated changes...
Questions: Are exotic plant species favoured by non-native ungulate herbivores and disadvantaged by native herbivores in forested rangelands? Do the impacts of ungulates on exotic vs native plants depend on forest management activities such as prescribed fire and stand thinning?
Location: Northeastern Oregon, USA.
Methods: We recorded changes in richness...
Full Text:
exotic plant guilds to cattle
and elk herbivory in forested rangeland
BurakK. Pekin, Michael J. Wisdom
Ungulates exert a strong influence on the composition and diversity of vegetation communities. However, little is known about how ungulate browsing pressure interacts with episodic disturbances such as fire and stand thinning. We assessed shrub responses to variable browsing pressure by cattle and elk in fuels treated (mechanical removal of...
Questions: Are exotic plant species favoured by non-native ungulate herbivores and disadvantaged by native herbivores in forested rangelands? Do the impacts of ungulates on exotic vs native plants depend on forest management activities such as prescribed fire and stand thinning?
Location: Northeastern Oregon, USA.
Methods: We recorded changes in richness...
Full Text:
Supporting information to the paper
Pekin, B.K. et al. Response
Questions: Are exotic plant species favoured by non-native ungulate herbivores and disadvantaged by native herbivores in forested rangelands? Do the impacts of ungulates on exotic vs native plants depend on forest management activities such as prescribed fire and stand thinning?
Location: Northeastern Oregon, USA.
Methods: We recorded changes in richness...
This thesis presents novel feedback and feedforward control system design strategies for active to passive vibration mitigation of residual vibrations on high speed machine tools. Residual vibrations on high-speed machine tools are triggered when the machine axes (table) undergo large accelerations, which induce sudden inertial forces and excite the lightly...
This thesis presents accurate and time-optimal smooth reference trajectory generation techniques for manufacturing equipment such as high-speed machine tools (MT) and industrial robots (IR). Typical machining tool-paths for MTs and IRs are defined as a series of discrete linear moves. Although Point-to-Point (P2P) feed motion can be generated by interpolating...
This work presents a novel optimal control strategy for precision motion control of flexible ball-screw feed drives. Typically, ball-screw feed drive control relies on state feedback taken both from motor and the load sides. The controller designed in this thesis is based on the non-collocated framework, where all the feedback...
High-performance mechatronic systems are widely used in precision manufacturing equipment such as CNC machine tools, 3D-Printers, photolithography systems, industrial robots, and Coordinate Measuring Machines (CMMs). These equipment are utilized in producing parts and components for aviation, semiconductor, optics, and many other emerging industries, with geometric features and surface properties within...
This thesis presents mechanics and dynamics of Low Frequency Vibration Assisted Turning (LFV-T). First, a mechanistic model for analytical cutting force and specific cutting energy prediction is presented. Kinematics of the process is used to analyze the cut surface topography and derive the uncut chip thickness variation for various modulation...
Prediction and mitigation of chatter vibrations in machining operations and optimizing overall machining mechanics are crucial for achieving greater productivity and manufacturing efficiency. This thesis first explores effect of directional relationships on chatter stability in milling process. Based on the directional relationships, a geometry-based chatter stability index (CSI) is proposed...
This work presents a new approach to enable accurate machining cycle-time prediction. While conventional computer-aided manufacturing (CAM) software estimates cycle times for given toolpaths, huge errors occur due to neglecting interpolator dynamics of numerical control (NC) systems. Typically, the machine changes its feedrate such as slowing down and speeding up...
Modulation assistance is widely employed to improve chip management in turning. This process is also known as modulated turning. Modulated turning transforms continuous cutting into intermittent cutting by periodically disengaging the tool tip from the workpiece, resulting in the generation of short, easily managed chips. This novel method improves the...
Optical sensing technologies are pivotal in the manufacturing process, specifically in defect detection, tool condition estimation, and monitoring. The research aims to enhance the accuracy, efficiency, and reliability of manufacturing metrology by employing optical sensing technologies, such as laser profilometers and image processing techniques. The dissertation proposes intelligent and flexible...
This research aims to demonstrate the viability of actively controlled distributed-electric propulsion as a method to postpone flutter in high aspect-ratio elastic wings. A semi-wing on a spring mount with two propellers powered by electric motors, mounted at alternate pitch angles relative to the chord line, was used as the...
Chainsaw users value cutting performance and safety. Knowledge of the forces exerted during sawing are necessary to understand and improve the cutting performance of saw chain. Additionally, cutting forces can be used to form metrics for evaluating performance tradeoffs when using a safety (i.e. low-kickback) saw chain versus a standard...
Deburring of machined parts is a crucial task in the aerospace and automotive industry. This process is still performed manually to a large extent due to the unpredictability of burr formation as well as the complex interactions between the human arm and the workpiece. Poor ergonomics, repetitive stress and strain...
New materials with superior mechanical properties, such as increased strength and hardness, have been developed to allow for new and improved products. However, the mechanical properties that make these materials useful also makes them difficult to process using conventional methods. New machining processes need to be developed to generate products...
Design and control of legged robots is a popular field in the pursuit of building robots that can be as mobile as humans. While much effort is put into understanding how to control the dynamics of these legs, less effort is focused on designing and controlling robot ankles. Ankles on...
This thesis explores the use of human kinesthetic input to advance robotic grasp planning. It specifically focuses on identification of human heuristics of grasp similarity by extensive human-subject experiments. This heuristic is then utilized to develop a robust metric for identifying similar robotic grasps. The central hypothesis of this work...
Deep rolling is a surface finishing technique that is widely used in several industries, specifically aerospace and automotive. Extending fatigue life by inducing compressive residual stresses at and below the deep rolled surface has been the primary driving force behind this newfound popularity. Understanding the development of the residual stresses...
Landslides are a common hazard worldwide that result in major economic, environmental and social impacts. Despite their devastating effects, inventorying existing landslides, often the regions at highest risk of reoccurrence, is challenging, time-consuming, and expensive. Current landslide mapping techniques include field inventorying, photogrammetric approaches, and use of bare-earth (BE) lidar...
Many animals and robots move through the world by coupling cyclical changes in shape called gaits to an interaction with the environment. Because mobility is an important aspect of such robots, a key metric when evaluating design and performance of mobile robots is the efficiency of their optimal gaits. The...
Recent advancements in joining operations and additive manufacturing now allow complex metal parts to be built up from raw materials, as opposed to being machined down from solid blocks. This not only opens up the design space, but also allows for much more efficient manufacturing. By decomposing a complex part...
The orb web is a multipurpose structure---serving as a home for its inhabitant spider, as a prey capture device, and as a physical extension of the spider’s sensing abilities. Biologists are particularly interested in the spider’s ability to locate prey trapped in its web by sensing the vibrations induced from...
Each year the United States: Forest Service (USFS) spends billions of dollars fighting forest fires. One strategy used by the USFS to prevent catastrophic fires is through forest restoration programs, in which potential forest fuel is removed through mechanized thinning. This program is expensive and generates high volumes of small-diameter...
Deciduous shrubs are an integral component of mixed conifer forests of the interior Pacific Northwest by providing structural complexity, forage, and niche habitat. Currently, these species are under pressure from high levels of ungulate herbivory and forest management activities such as fuels reduction treatments. Ungulate herbivory is influential in the...
Ventenata dubia L. (ventenata) is an introduced, winter annual grass that has recently been raising concerns across the Pacific Northwest Bunchgrass Prairie and the Palouse Prairie. It is well established now in pasturelands, croplands, and a variety of ecosystems including grasslands, sagebrush steppe, ponderosa pine forests and woodlands. Ventenata is...
We present a novel technique to simultaneously measure wind speed (U) at thousands of locations continuously in time based on measurement of velocity-dependent heat transfer from a heated surface. Measuring temperature differences between paired passive and actively heated fiber-optic (AHFO) cables with a distributed temperature sensing system allowed estimation of...
We present a novel approach based on fibre-optic distributed temperature sensing (DTS) to measure the two-dimensional thermal structure of the surface layer at high resolution (0.25 m, ≈ 0.5 Hz). Air temperature observations obtained from a vertically oriented fibre optics array of approximate dimensions 8 m x 8 m and...
Ten experiments were conducted to determine the vitamin requirements
of coturnix quail (Coturnix coturnix japonica) to 2 weeks
of age using a glucose monohydrate-isolated soybean protein diet.
A preliminary study consisting of 2 separate experiments was
conducted to determine those vitamins essential to the growing
coturnix. This study revealed that...
This study explores the role of classroom use of live organisms as a pathway for the spread of invasive species. The overall guiding research question is “Are behavioral changes necessary to reduce the spread from the classroom pathway?” Using focus groups comprised of key educators, this study seeks to identify...
Introduced vector-borne diseases, particularly avian malaria (Plasmodium relictum) and avian pox
virus (Avipoxvirus spp.), continue to play significant roles in the decline and extinction of native forest birds in
the Hawaiian Islands. Hawaiian honeycreepers are particularly susceptible to avian malaria and have survived
into this century largely because of persistence...
The corrosion and passivity of iron (and carbon steel) in media with different alkalinity as well as iron depassivation have been studied extensively using electrochemical methods and nano-scale surface characterization studies. The electrochemical techniques provide valuable information about the average electrochemical behavior of relatively large metal surfaces, typically in centimeter-square...
In this paper, we consider a flowshop scheduling problem with sequence-dependent setup times and a bicriteria objective to minimize the work-in-process inventory for the producer and to maximize the customers' service level. The use of a bicriteria objective is motivated by the fact that successful companies in today's environment not...
It really doesn’t matter, because you can learn and have fun with the
4-H Poultry Project studying either the chicken or the egg. You don’t
even have to own a flock!
• Learn how to brood, feed, and care for chickens, turkeys, ducks,
geese, guinea fowl, pheasants, or other wild...
Published March 2004. Reviewed July 2014. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
I assessed potential barriers to dispersal using homing tendency and investigated the movements and settlement site selection of pygmy rabbits (Brachylagus idahoensis) after short distance translocations in southeastern Oregon from June – December 2008. I captured, radio marked, and translocated 59 pygmy rabbits 1-2 km across landscapes with (1) continuous...
We investigated the movements and selection of settlement sites of translocated pygmy rabbits (Brachylagus idahoensis) in southeastern Oregon from June to December 2008. We captured, radio tagged, and translocated 59 pygmy rabbits across big sagebrush (Artemisia tridentata ssp.) habitat with 3 categories of landscape fragmentation. We used radio telemetry to...
Wildlife managers often use species distribution models (SDMs) as an initial tool in conservation planning. Managers and researchers have made efforts to model the habitat and distribution of pygmy rabbits (Brachylagus idahoensis) across their historic range since the species was proposed for listing under the Endangered Species Act (USFWS 2003)....
Accurate methods are needed to measure changing soil water content from meter to kilometer scales. Laboratory results demonstrate the feasibility of the heat pulse method implemented with fiber optic temperature sensing to obtain accurate distributed measurements of soil water content. A fiber optic cable with an electrically conductive armoring was...
I investigated survival, movements, home range sizes, and habitat selection of pygmy rabbits (Brachylagus idahoensis) in southeastern Oregon and northwestern Nevada from June 2005 to June 2007. I trapped 298 rabbits on four sites and fitted each with radio transmitters. More than 13,000 locations of telemetered rabbits were recorded. I...
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K. Model selection results for study-wide habitat categories for pygmy rabbits
on four study
In lentic water bodies, such as lakes, the water temperature near the surface typically increases during the day, and decreases during the night as a consequence of the diurnal radiative forcing (solar and infrared radiation). These temperature variations penetrate vertically into the water, transported mainly by heat conduction enhanced by...
Amphibians are experiencing global population declines and are one of the most threatened groups of vertebrates. This can be attributed to multiple environmental stressors such as habitat loss, disease, invasive species, and climate change. For vocal amphibian species, loss of acoustic habitat due to anthropogenic noise may be yet another...
Published March 1916. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Biomass gasification is a promising way to obtain green energy, but the gas composition makes it unsuitable for use in traditional technologies (i.e., IC engine). Gas purification over nickel and/or iron catalysts is an attractive alternative. Cellulose-based carbon aerogels (CAGs) have shown suitable physical chemical properties for use as catalyst...
A new method for the preparation of the 2, 3, 3a,8a-tetrahydro-2-hydroxyfuro[2, 3-b] benzofuran, XXX, ring system has been developed. The synthesis envolved a substitution reaction of phenol, XXIV, with 1-bromo-2, 5-hexadiene, XXV, to give 2, 5-hexadien-l -yl phenyl ether, XXVII. The ether was rearranged via an ortho-Claisen rearrangement to 3-(o-hydroxyphenyl)-l,...
Environmental swabs and meat samples from two of three seafood
processing plants sampled on the Oregon Coast were found to
contain Salmonella. Although these enteropathogens were not isolated
from the finished products, the danger of contamination is great
since the processing received by many seafoods is not designed to
yield...