Airborne geophysical surveying for hazardous waste site characterization on the Oak Ridge Reservation, Tennessee

Geophysics ◽  
2000 ◽  
Vol 65 (5) ◽  
pp. 1372-1387 ◽  
Author(s):  
W. E. Doll ◽  
J. E. Nyquist ◽  
L. P. Beard ◽  
T. J. Gamey
Keyword(s):  
Hazardous Waste ◽  
Large Scale ◽  
Magnetic Measurements ◽  
Geophysical Methods ◽  
Field Tests ◽  
Geological Mapping ◽  
Petroleum Exploration ◽  
Electromagnetic System ◽  
Oak Ridge

Airborne geophysical methods that were developed for mineral and petroleum exploration can, with some modification, be applied to environmental problems where large areas must be characterized. A helicopter survey that deployed magnetic, electromagnetic, and radiometric sensors carried out one of the first large‐scale airborne environmental surveys at a U.S. government facility at Oak Ridge, Tennessee in 1993–1994. The survey included testing of a new airborne electromagnetic system designed specifically for environmental applications and for controlled field tests of magnetic systems. Helicopter‐borne magnetic measurements were capable of discriminating groups of as few as ten metallic 208-liter (55-gallon) storage drums under representative field conditions. Magnetic and electromagnetic sensors were able to distinguish groups of metal‐filled waste disposal trenches within disposal sites, but were unable to resolve individual trenches. Electromagnetic data proved to be the most effective airborne technique for geological mapping in this portion of the Appalachian fold‐and‐thrust belt and for locating karst features. Radiometric measurements were useful both in geological mapping and in detecting zones of high radiation related to hazardous waste. The Oak Ridge survey proved valuable for quickly screening large areas and for locating anomalies for subsequent ground follow‐up. On‐board video was used to reduce the number of instances of ground follow‐up by allowing the visual screening of anomalous areas.

GEOPHYSICAL RESEARCH AND PROGRESS IN EXPLORATION

Geophysics ◽  
1957 ◽  
Vol 22 (2) ◽  
pp. 412-433 ◽  
Author(s):  
Milton B. Dobrin ◽  
Henry F. Dunlap
Keyword(s):  
Large Scale ◽  
Gulf Coast ◽  
Academic Research ◽  
Geophysical Methods ◽  
Petroleum Exploration ◽  
Seismic Exploration ◽  
Annual Review ◽  
Neutron Generation ◽  
Geophysical Research ◽  
Research Activities

This paper, the SEG Research Committee’s second annual review of current developments in exploration geophysics, will emphasize research activities at universities and other non‐commercial institutions which relate closely to geophysical exploration. Industry developments worth noting in the seismic field include the considerable increase in use of magnetic recording, use of pressure‐sensitive geophones with preamplifiers in the bay and marsh areas of the Gulf Coast, use of fathometer‐type instruments to obtain near bottom layering in marine areas, and use of nonphotographic methods of reproducing seismic data. Considerable experimentation with weight dropping techniques, and with use of higher frequencies to get better resolution has continued during the past year. Use of models, particularly two dimensional models, is increasing. There have been significant innovations in logging techniques, particularly in the use of in‐hole accelerators for neutron generation, and in the development of in‐hole equipment for measuring gamma ray spectra. The use of continuous velocity logs is increasing. Academic research has been of two kinds. First, there are studies of basic physical principles underlying current or prospective exploration methods which could lead to improvements and new applications. Secondly, geophysical methods originally developed for petroleum exploration are being employed for large‐scale investigations of the earth’s crustal structure. These studies should contribute important information on the geology of such features as continental shelves, geosynclines, and mountain systems, information potentially useful to geologists for developing new concepts in exploration thinking. The two kinds of research illustrate the current interdependence between “pure” and “applied” geophysics. Important research projects on scattering, statistical improvement of signal‐to‐noise, explosionwave generation in the earth, and surface waves exemplify the activity going on in university laboratories today which may result in improved seismic exploration techniques tomorrow. Conversely, university‐sponsored seismic and gravity investigations of the deep oceans, the continental margins and various western mountain chains illustrate how geophysics is contributing basic geologic information on a regional to global scale.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Therapy of post-stroke depression – a systematic review

2013 ◽  
Vol 10 (02) ◽  
pp. 108-129 ◽  
Author(s):  
W. Gaebel ◽  
W. Wannagat ◽  
J. Zielasek
Keyword(s):  
Systematic Review ◽  
Large Scale ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Placebo Control ◽  
Post Stroke ◽  
Pharmacological Studies ◽  
Post Stroke Depression ◽  
Control Procedures ◽  
Antidepressant Pharmacotherapy

SummaryWe performed a systematic review of randomized placebo-controlled pharmacological and non-pharmacological trials for the therapy and prevention of post-stroke depression that have been published between 1980 and 2011. We initially identified 2 260 records of which 28 studies were finally included into this review. A meta-analytic approach was hampered by considerable differences regarding the kinds of therapeutic regimens and the study durations. Modest effects favoring treatment of post-stroke depression could be found for pharmacological treatment as well as repetitive transcranial magnetic stimulation. For the prevention of post-stroke depression, antidepressant pharmacotherapy showed promising results. However, large-scale studies with better standardized study populations, optimized placebo control procedures in non-pharmacological studies, and replication in larger follow-up studies are still necessary to find the optimal therapeutic regimens to prevent and treat post-stroke depression.

The Effect of the Familiarity of a Survey Sender on Response Outcomes in a Large-Scale Survey of Emergency Medical Services Agencies

2021 ◽  
Vol 44 (3) ◽  
pp. 260-267
Author(s):  
Morgan M. Millar ◽  
Hilary A. Hewes ◽  
Andrea L. Genovesi ◽  
Michael Ely ◽  
Braden Green ◽  
...  
Keyword(s):  
Emergency Medical Services ◽  
Large Scale ◽  
Nationwide Survey ◽  
Survey Response ◽  
Medical Services ◽  
Healthcare Organizations ◽  
Emergency Medical ◽  
Established Relationship ◽  
To Receive

Survey response is higher when the request comes from a familiar entity compared to an unknown sender. Little is known about how sender influences response to surveys of organizations. We assessed whether familiarity of the sender influences response outcomes in a survey of emergency medical services agencies. Emergency medical services agencies in one U.S. state were randomly assigned to receive survey emails from either a familiar or unfamiliar sender. Both deployment approaches were subsequently used nationwide, with each state selecting one of the two contact methods. Experimental results showed that requests from the familiar sender achieved higher survey response (54.3%) compared to requests from the unfamiliar sender (36.9%; OR: 2.03; 95% CI: 1.23, 3.33). Similar results were observed in the subsequent nationwide survey; in states where the familiar sender deployed the survey, 62.0% of agencies responded, compared to 51.0% when the survey was sent by the unfamiliar sender (OR: 1.57; 95% CI: 1.47, 1.67). The response difference resulted in nearly 60 additional hours of staff time needed to perform telephone follow-up to nonrespondents. When surveying healthcare organizations, surveyors should recognize that it is more challenging to obtain responses without a pre-established relationship with the organizations.

scholarly journals Wireless Sensor Networks for Smart Cities: Network Design, Implementation and Performance Evaluation

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 218
Author(s):  
Ala’ Khalifeh ◽  
Khalid A. Darabkh ◽  
Ahmad M. Khasawneh ◽  
Issa Alqaisieh ◽  
Mohammad Salameh ◽  
...  
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Experimental Evaluation ◽  
Large Scale ◽  
Performance Metrics ◽  
Smart Cities ◽  
Field Tests ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Real Field

The advent of various wireless technologies has paved the way for the realization of new infrastructures and applications for smart cities. Wireless Sensor Networks (WSNs) are one of the most important among these technologies. WSNs are widely used in various applications in our daily lives. Due to their cost effectiveness and rapid deployment, WSNs can be used for securing smart cities by providing remote monitoring and sensing for many critical scenarios including hostile environments, battlefields, or areas subject to natural disasters such as earthquakes, volcano eruptions, and floods or to large-scale accidents such as nuclear plants explosions or chemical plumes. The purpose of this paper is to propose a new framework where WSNs are adopted for remote sensing and monitoring in smart city applications. We propose using Unmanned Aerial Vehicles to act as a data mule to offload the sensor nodes and transfer the monitoring data securely to the remote control center for further analysis and decision making. Furthermore, the paper provides insight about implementation challenges in the realization of the proposed framework. In addition, the paper provides an experimental evaluation of the proposed design in outdoor environments, in the presence of different types of obstacles, common to typical outdoor fields. The experimental evaluation revealed several inconsistencies between the performance metrics advertised in the hardware-specific data-sheets. In particular, we found mismatches between the advertised coverage distance and signal strength with our experimental measurements. Therefore, it is crucial that network designers and developers conduct field tests and device performance assessment before designing and implementing the WSN for application in a real field setting.

scholarly journals Evaluating the Long-Term Efficacy of COVID-19 Vaccines

2021 ◽  
Author(s):  
Dan-Yu Lin ◽  
Donglin Zeng ◽  
Peter B Gilbert
Keyword(s):  
Large Scale ◽  
Crossover Designs ◽  
Phase 3 ◽  
Term Efficacy ◽  
Timely Access ◽  
Efficacious Vaccine ◽  
Trial Participants ◽  
Ongoing Phase

Abstract Large-scale deployment of safe and durably effective vaccines can curtail the COVID-19 pandemic.1−3 However, the high vaccine efficacy (VE) reported by ongoing phase 3 placebo-controlled clinical trials is based on a median follow-up time of only about two months4−5 and thus does not pertain to long-term efficacy. To evaluate the duration of pro- tection while allowing trial participants timely access to efficacious vaccine, investigators can sequentially cross participants over from the placebo arm to the vaccine arm according to priority groups. Here, we show how to estimate potentially time-varying placebo-controlled VE in this type of staggered vaccination of participants. In addition, we compare the per- formance of blinded and unblinded crossover designs in estimating long-term VE.

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