906 research outputs found
Mapping Groundwater Discharge Along Lake Margins Using Satellite And UAV Thermal Imagery
Effective watershed management decisions depend on understanding groundwater-surface water interactions. Traditional hydrogeological investigations are invasive, time-consuming, and expensive; therefore, regions that lack accessibility or agency funding need other ways of evaluating groundwater-lake interactions. Heat has long been known to be an effective groundwater tracer. Groundwater is insulated from most solar radiation, and its temperature does not fluctuate greatly from the annual average air temperature year-round in higher latitudes. In contrast, lakes are directly exposed to solar radiation, and water temperature fluctuates greatly both seasonally and diurnally. The winter and summer seasons produce the greatest contrast between groundwater and surface water temperatures. An empirical groundwater flow model of the water table near Detroit Lakes, Minnesota, was created using digital elevation model data and GIS analysis tools. This model estimates the distribution of potential groundwater discharge zones for further investigation with thermal imagery. Thermal remote sensing data acquired by satellite (ASTER) are freely available, non-invasive, and may serve as an effective means to identify potential areal groundwater recharge and discharge. Higher resolution thermal data were collected by using a DJI Matrice 600 UAV fitted with a FLIR Zenmuse XT thermal imaging sensor, which provides a potentially fast, minimally invasive, and cost-effective method for identifying possible groundwater discharge points within waterbodies at regional scales. Results suggest that large, well-defined springs and seeps can be identified with UAS imagery, but that slower groundwater seepage in
shoreline areas is obscured by land cover, weather conditions, emergent vegetation, sediment characteristics, and other factors. The large scale of imagery coupled with local thermal heterogeneity leads to limited information on groundwater discharge from satellite imagery
The Zero-Point Field and Inertia
A brief overview is presented of the basis of the electromagnetic zero-point
field in quantum physics and its representation in stochastic electrodynamics.
Two approaches have led to the proposal that the inertia of matter may be
explained as an electromagnetic reaction force. The first is based on the
modeling of quarks and electrons as Planck oscillators and the method of
Einstein and Hopf to treat the interaction of the zero-point field with such
oscillators. The second approach is based on analysis of the Poynting vector of
the zero-point field in accelerated reference frames. It is possible to derive
both Newton's equation of motion, F=ma, and its relativistic co-variant form
from Maxwell's equations as applied to the zero-point field of the quantum
vacuum. This appears to account, at least in part, for the inertia of matter.Comment: 8 pages, no fig
A Comment on "The Far Future of Exoplanet Direct Characterization" - the Case for Interstellar Space Probes
Following on from ideas presented in a recent paper by Schneider et al.
(2010) on "The Far Future of Exoplanet Direct Characterization", I argue that
they have exaggerated the technical obstacles to performing such 'direct
characterization' by means of fast (order 0.1c) interstellar space probes. A
brief summary of rapid interstellar spaceflight concepts that may be found in
the literature is presented. I argue that the presence of interstellar dust
grains, while certainly something which will need to be allowed for in
interstellar vehicle design, is unlikely to be the kind of 'show stopper'
suggested by Schneider et al. Astrobiology as a discipline would be a major
beneficiary of developing an interstellar spaceflight capability, albeit in the
longer term, and I argue that astrobiologists should keep an open mind to the
possibilities.Comment: Accepted for publication in Astrobiolog
An Exploratory Study of Forces and Frictions affecting Large-Scale Model-Driven Development
In this paper, we investigate model-driven engineering, reporting on an
exploratory case-study conducted at a large automotive company. The study
consisted of interviews with 20 engineers and managers working in different
roles. We found that, in the context of a large organization, contextual forces
dominate the cognitive issues of using model-driven technology. The four forces
we identified that are likely independent of the particular abstractions chosen
as the basis of software development are the need for diffing in software
product lines, the needs for problem-specific languages and types, the need for
live modeling in exploratory activities, and the need for point-to-point
traceability between artifacts. We also identified triggers of accidental
complexity, which we refer to as points of friction introduced by languages and
tools. Examples of the friction points identified are insufficient support for
model diffing, point-to-point traceability, and model changes at runtime.Comment: To appear in proceedings of MODELS 2012, LNCS Springe
Construction Management Services for the new WPI Residence Hall
This project presents an alternative design for the foundation wall of the Worcester Polytechnic Institute new residence hall to resist lateral loading during construction. The cost implications of this alternative design were also investigated. A 3-D model of the structure of the building was also constructed using Autdesk Revit software and a quantity takeoff was developed using this model. A cost estimate and takeoff for the structure were also performed and an earned value analysis was developed to access the progress of construction of the exterior walls
Non-invasive voiding assessment in conscious mice
OBJECTIVE: To review available options of assessing murine bladder function and to evaluate a non-invasive technique
suitable for long-term recording.
METHODS: We reviewed previously described methods to record rodent bladder function. We used modified metabolic
cages to capture novel recording tracings of mouse micturition. We evaluated our method in a pilot study with female
mice undergoing partial bladder outlet obstruction or sham operation, respectively; half of the partial obstruction and
sham group received treatment with an S6K-inhibitor, targeting the mTOR pathway, which is known to be implicated in
bladder response to obstruction.
RESULTS: Our non-invasive method using continuous urine weight recording reliably detected changes in murine
bladder function resulting from partial bladder outlet obstruction or treatment with S6K-inhibitor. We found obstruction
as well as treatment with S6K-inhibitor to correlate with a hyperactive voiding pattern.
CONCLUSIONS: While invasive methods to assess murine bladder function largely disturb bladder histology and intrinsically render post-cystometry gene expression analysis of questionable value, continuous urine weight recording is
a reliable, inexpensive, and critically non-invasive method to assess murine bladder function, suitable for a long-term
application
Postoperative outcome of ambulatory dogs with intervertebral disc extrusion causing incontinence and/or tail dysfunction:18 cases (2010-2020)
OBJECTIVES: To assess the recovery of urinary continence, faecal continence and tail function in ambulatory dogs with caudal lumbar intervertebral disc extrusion and to explore clinical factors that may be associated with recovery. MATERIALS AND METHODS: Medical records from January 2010 to December 2020 were searched to identify ambulatory dogs undergoing surgical treatment for a caudal lumbar intervertebral disc extrusion causing urinary incontinence, faecal incontinence and/or tail dysfunction. Signalment, history, presenting clinical signs, neurological examination findings, diagnostic test results, treatment and outcome were recorded for all dogs. RESULTS: Eighteen dogs with caudal lumbar intervertebral disc extrusion causing tail dysfunction, urinary and/or faecal incontinence were included. Urinary continence was recovered in 12 (86%) of 14 affected dogs, faecal continence recovered in nine (90%) of 10 affected dogs and tail function recovered in 13 (87%) of 15 affected dogs. Loss of tail nociception was recorded in three dogs on presentation; two made a full recovery and one showed mild persistent tail paresis. CLINICAL SIGNIFICANCE: The prognosis for functional recovery of urinary continence, faecal continence and tail function in ambulatory dogs with caudal lumbar intervertebral disc extrusion following surgical treatment is good. Larger studies are needed to identify prognostic factors associated with failure of recovery
Iron oxide nanowires from bacteria biofilm as an edfficient visible-light magnetic photocatalyst
Published: July 15, 2016Naturally produced iron oxide nanowires by Mariprofundus ferrooxydans bacteria as biofilm are evaluated for their structural, chemical, and photocatalytic performance under visible-light irradiation. The crystal phase structure of this unique natural material presents a 1-dimensional (1D) nanowire-like geometry, which is transformed from amorphous to crystalline (hematite) by thermal annealing at high temperature without changing their morphology. This study systematically assesses the effect of different annealing temperatures on the photocatalytic activity of iron oxide nanowires produced by Mariprofundus ferrooxydans bacteria. The nanowires processed at 800 °C were the most optimal for photocatalytic applications degrading a model dye (rhodamine B) in less than an hour. These nanowires displayed excellent reusability with no significant loss of activity even after 6 cycles. Kinetic studies by using hydrogen peroxide (radical generator) and isopropyl alcohol (radical scavenger) suggest that OH• is the dominant photooxidant. These nanowires are naturally produced, inexpensive, highly active, stable, and magnetic and have the potential to be used for broad applications including environmental remediation, water disinfection, and industrial catalysis.Luoshan Wang, Tushar Kumeria, Abel Santos, Peter Forward, Martin F. Lambert, and Dusan Losi
The mathematical theory of resonant transducers in a spherical gravity wave antenna
The rigoruos mathematical theory of the coupling and response of a spherical
gravitational wave detector endowed with a set of resonant transducers is
presented and developed. A perturbative series in ascending powers of the
square root of the ratio of the resonator to the sphere mass is seen to be the
key to the solution of the problem. General layouts of arbitrary numbers of
transducers can be assessed, and a specific proposal (PHC), alternative to the
highly symmetric TIGA of Merkowitz and Johnson, is described in detail.
Frequency spectra of the coupled system are seen to be theoretically recovered
in full agreement with experimental determinations.Comment: 31 pages, 7 figures, LaTeX2e, \usepackage{graphicx,deleq
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