A SUBSURFACE ELECTROMAGNETIC PULSE RADAR

An electromagnetic pulse radar has been developed for investigation of subsurface geology and man‐made targets. The radar uses separate broadband dipole‐type antennas for transmission and reception. The antennas are well matched to the soil or rock surface. An orthogonal orientation of the antennas on the medium surface effectively decouples them and also prevents reflections from the air‐medium interface or any horizontal stratification from being seen. Two versions of the radar are used: small 6-ft dipoles with a shock‐type (250 picosec) pulse for shallow soundings and 24-ft dipoles with a 45 nanosec pulse for deeper soundings. Signatures of faults, joints, cavities, and lithologic contrasts in soft rock have been obtained with the radar, and these results are presented. A sampling oscilloscope acts as a receiver for the radar, and the target signatures are isolated portions of the time record whose time delays agree with the physical geometry and measured pulse velocities for the medium. For a large void at a depth of 20 ft in limestone, a frequency domain signature is also given to illustrate the potential of using both temporal and spectral signatures. Signatures of an exposed fault in a dolomite quarry are used via mapping measurements to delineate the direction of a minor fault. Signatures of two lithologic contrasts at depths of 40 ft in the dolomite are given. The signatures of a drift coal mine tunnel as measured from a hill 11 to 26 ft above the tunnel are shown. Unique features of the radar are enumerated and present capabilities are summarized.

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Subsurface electromagnetic pulse radar

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(76)90693-8 ◽

1976 ◽

Vol 13 (10) ◽

pp. 129

Keyword(s):

Electromagnetic Pulse ◽

Pulse Radar

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Cast-in-place bored piles on soft rock under artesian pressures

Canadian Geotechnical Journal ◽

10.1139/t84-075 ◽

1984 ◽

Vol 21 (4) ◽

pp. 684-698 ◽

Cited By ~ 3

Author(s):

Hari D. Sharma ◽

S. Sengupta ◽

Glen Harron

Keyword(s):

Soft Rock ◽

Load Test ◽

Rock Surface ◽

Weathered Rock ◽

Concrete Piles ◽

Geotechnical Investigations ◽

Load Tests ◽

Undrained Strength ◽

Pile Load Tests ◽

A Site

This paper outlines the geotechnical investigations and axial compression, pullout, and lateral pile load tests that were carried out at a site where cast-in-place bored concrete piles were installed. These piles were designed to bear on top of soft weathered rock surface that was under artesian pressures. Pile load test results have been compared with theoretically calculated pile capacities. It has been found that in areas of high artesian pressures in bedrock axial compressive pile load capacities theoretically estimated by conventional methods were significantly higher than the values obtained from load tests. Recommendations have been made that representative exposed bedrock samples be tested to determine their undrained strength, and these values be used for estimating theoretical pile capacities. Construction problems encountered during pile installation, such as locating the top of weathered bedrock without penetrating through water-bearing layers that were under artesian pressures, are presented briefly and a solution provided to install belled piles on top of bedrock is discussed. Key words: bored concrete piles, construction problems, load tests, soft weathered rock under artesian pressures, ultimate pile load capacities.

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Nebraska Supreme Court Rules a Minor in Foster Care Seeking an Abortion Must Obtain Foster Parents Consent – In re Anonymous 5

American Journal of Law & Medicine ◽

10.1017/s0098858800000083 ◽

2014 ◽

Vol 40 (1) ◽

pp. 172-174

Author(s):

Tulsi A. Patel

Keyword(s):

Foster Care ◽

Supreme Court ◽

Foster Parents ◽

Care Seeking ◽

A Minor

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Rating Post-Operative Backs (Part I)

Guides Newsletter ◽

10.1001/amaguidesnewsletters.1997.julaug01 ◽

1997 ◽

Vol 2 (4) ◽

pp. 1-3

Author(s):

James B. Talmage

Keyword(s):

Spinal Stenosis ◽

Foot Drop ◽

Neurogenic Claudication ◽

Root Damage ◽

Fourth Edition ◽

Minor Strain ◽

Injury Model ◽

Strain Type ◽

A Minor ◽

Anterior Tibialis

Abstract The AMA Guides to the Evaluation of Permanent Impairment, Fourth Edition, uses the Injury Model to rate impairment in people who have experienced back injuries. Injured individuals who have not required surgery can be rated using differentiators. Challenges arise when assessing patients whose injuries have been treated surgically before the patient is rated for impairment. This article discusses five of the most common situations: 1) What is the impairment rating for an individual who has had an injury resulting in sciatica and who has been treated surgically, either with chemonucleolysis or with discectomy? 2) What is the impairment rating for an individual who has a back strain and is operated on without reasonable indications? 3) What is the impairment rating of an individual with sciatica and a foot drop (major anterior tibialis weakness) from L5 root damage? 4) What is the rating for an individual who is injured, has true radiculopathy, undergoes a discectomy, and is rated as Category III but later has another injury and, ultimately, a second disc operation? 5) What is the impairment rating for an older individual who was asymptomatic until a minor strain-type injury but subsequently has neurogenic claudication with severe surgical spinal stenosis on MRI/myelography? [Continued in the September/October 1997 The Guides Newsletter]

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Pelvic Impairments

Guides Newsletter ◽

10.1001/amaguidesnewsletters.2018.julaug02 ◽

2018 ◽

Vol 23 (4) ◽

pp. 9-10

Author(s):

James Talmage ◽

Jay Blaisdell

Keyword(s):

Pelvic Ring ◽

Reproductive Organs ◽

High Impact ◽

Pelvic Fractures ◽

Motor Dysfunction ◽

Impact Event ◽

Concomitant Injuries ◽

Rating Process ◽

Pass Through ◽

A Minor

Abstract Pelvic fractures are relatively uncommon, and in workers’ compensation most pelvic fractures are the result of an acute, high-impact event such as a fall from a roof or an automobile collision. A person with osteoporosis may sustain a pelvic fracture from a lower-impact injury such as a minor fall. Further, major parts of the bladder, bowel, reproductive organs, nerves, and blood vessels pass through the pelvic ring, and traumatic pelvic fractures that result from a high-impact event often coincide with damaged organs, significant bleeding, and sensory and motor dysfunction. Following are the steps in the rating process: 1) assign the diagnosis and impairment class for the pelvis; 2) assign the functional history, physical examination, and clinical studies grade modifiers; and 3) apply the net adjustment formula. Because pelvic fractures are so uncommon, raters may be less familiar with the rating process for these types of injuries. The diagnosis-based methodology for rating pelvic fractures is consistent with the process used to rate other musculoskeletal impairments. Evaluators must base the rating on reliable data when the patient is at maximum medical impairment and must assess possible impairment from concomitant injuries.

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The Effect of Path Length and Display Size on Memory for Spatial Information

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169/a000137 ◽

2012 ◽

Vol 59 (3) ◽

pp. 147-152 ◽

Cited By ~ 11

Author(s):

Katherine Guérard ◽

Sébastien Tremblay

Keyword(s):

Path Length ◽

Potential Role ◽

Spatial Information ◽

Recall Performance ◽

Minor Role ◽

Length Effect ◽

Serial Memory ◽

Fixed Reference ◽

A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

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