scholarly journals The Influence of Soil Parameters on the Impulse and Airblast Overpressure Loading above Surface-Laid and Shallow-Buried Explosives

2011 ◽  
Vol 18 (6) ◽  
pp. 857-874 ◽  
Author(s):  
John Q. Ehrgott Jr. ◽  
Stephen A. Akers ◽  
Jon E. Windham ◽  
Denis D. Rickman ◽  
Kent T. Danielson
Keyword(s):  
Research Effort ◽  
Silty Sand ◽  
Experimental Program ◽  
Bottom Surface ◽  
Soil Parameters ◽  
First Year ◽  
Near Surface ◽  
Us Army ◽  
Military Vehicles ◽  
The Us

The dynamic airblast, fragmentation, and soil ejecta loading environments produced by the detonation of surface-laid and shallow-buried mines are major threats to lightweight military vehicles. During the past several years, the US Army has focused considerable attention on developing improved methods for predicting the below-vehicle environment from these threats for use by vehicle/armor analysts; thereby, improving the survivability of these platforms. The US Army Engineer Research and Development Center recently completed the first year of a three-year effort to experimentally and numerically quantify the blast and fragment loading environments on vehicles due to surface and subsurface mine and IED detonations. As part of this research effort, a series of experiments was conducted to quantify the effects of soil parameters on the aboveground blast environments produced by the detonation of aboveground bottom-surface-tangent, buried top-surface-tangent, and shallow-buried 2.3-kg (5-lb) Composition C4 charges. The experiments were conducted using three different well characterized soils; 10.8% air-filled-voids (AFV) silty sand, 5.4% AFV clay, and 29.8% AFV poorly graded sand. The combined aboveground loads due to airblast and soil debris were measured by an impulse measurement device. The near-surface airblast overpressure was quantified by a series of side-on measurements above the charges at one elevation and three radial distances. This paper summarizes and compares the results of the experimental program with emphasis on defining the effect of soil parameters on the aboveground blast environment.

Explosive Removal of Concrete From Reinforced Walls

2007 ◽  
Author(s):  
Denis D. Rickman ◽  
John Q. Ehrgott ◽  
Stephen A. Akers ◽  
Jon E. Windham ◽  
Dennis W. Moore
Keyword(s):  
Explosive Charge ◽  
Research Effort ◽  
Us Army ◽  
Steel Reinforced Concrete ◽  
The Past ◽  
The Us ◽  
Development Center ◽  
The Relationship ◽  
Improved Methods ◽  
Combat Environment

During the past several years, the US Army has focused considerable attention toward developing improved methods for breaching walls in the urban combat environment. A major thrust area is centered on finding improved methods to breach the toughest wall type that Army units are likely to face: a double (steel) reinforced concrete (RC) wall. One impediment to this effort is that the relationship between the contact explosive charge configuration and the quantity of concrete removed has not been thoroughly understood. The U.S. Army Engineer Research and Development Center has conducted a research effort to better define the effectiveness of various explosive charge configurations in breaching RC walls. This paper presents a discussion of results from this research.

scholarly journals Assessing Financial Education: Evidence from Boot Camp

2016 ◽  
Vol 8 (2) ◽  
pp. 322-343 ◽  
Author(s):  
William Skimmyhorn
Keyword(s):  
Financial Management ◽  
Natural Experiment ◽  
Financial Education ◽  
First Year ◽  
Retirement Savings ◽  
Market Outcomes ◽  
Us Army ◽  
The Us ◽  
Credit Scores ◽  
Second Year

This study estimates the effects of Personal Financial Management Course attendance and enrollment assistance using a natural experiment in the US Army. New enlistees' course attendance reduces the probability of having credit account balances, average balances, delinquencies, and adverse legal actions in the first year after the course, but it has no effects on accounts in the second year or credit scores in either year. The course and its enrollment assistance substantially increase retirement savings rates and average monthly contributions, with effects that persist through at least two years. The course has no significant effects on military labor market outcomes. (JEL D14, I21, J45)

Convection in Underground Oil Caverns: The Role of Double Diffusion

2007 ◽  
Author(s):  
H. J. S. Fernando ◽  
C. Y. Ching ◽  
Z. Zhao ◽  
S. Pol ◽  
S. W. Webb
Keyword(s):  
Double Diffusion ◽  
Experimental Program ◽  
Bottom Surface ◽  
Compositional Gradient ◽  
Geothermal Heating ◽  
The Us ◽  
Strategic Petroleum Reserve ◽  
Side Walls ◽  
Salt Caverns ◽  
Double Diffusive

The US Strategic Petroleum Reserve (SPR) stores oil in large underground salt caverns. This oil has compositional and thermal gradients induced by geothermal heating from both the bottom surface and side walls. Temperature layering has been recorded in SPR oil caverns, which is hypothesized to be predominantly due to double-diffusive layering that occurs when a stable compositional gradient is heated from below. Initial results of a laboratory experimental program aimed at studying dynamics of such double-diffusive layers in the context of SPR are described in this paper. Of particular interest are the thickness of convecting layers, layer evolution (migration/merging) and conditions for the formation/non-formation of double-diffusive layers.

Neuro-Optometric Treatment of Complications from a Cerebellar Astrocytoma

2020 ◽  
pp. 304-312
Keyword(s):  
Visual System ◽  
Common Site ◽  
Us Army ◽  
Cranial Nerve Palsies ◽  
Pilocytic Astrocytomas ◽  
The Us ◽  
Extent Of Damage ◽  
Functional Components ◽  
The Brain

Background: Insult to the brain, whether from trauma or other etiologies, can have a devastating effect on an individual. Symptoms can be many and varied, depending on the location and extent of damage. This presentation can be a challenge to the optometrist charged with treating the sequelae of this event as multiple functional components of the visual system can be affected. Case Report: This paper describes the diagnosis and subsequent ophthalmic management of an acquired brain injury in a 22 year old male on active duty in the US Army. After developing acute neurological symptoms, the patient was diagnosed with a pilocytic astrocytoma of the cerebellum. Emergent neurosurgery to treat the neoplasm resulted in iatrogenic cranial nerve palsies and a hemispheric syndrome. Over the next 18 months, he was managed by a series of providers, including a strabismus surgeon, until presenting to our clinic. Lenses, prism, and in-office and out-of-office neurooptometric rehabilitation therapy were utilized to improve his functioning and make progress towards his goals. Conclusions: Pilocytic astrocytomas are the most common primary brain tumors, and the vast majority are benign with excellent surgical prognosis. Although the most common site is the cerebellum, the visual pathway is also frequently affected. If the eye or visual system is affected, optometrists have the ability to drastically improve quality of life with neuro-optometric rehabilitation.

EDUCATIONAL-TRAINING FACILITIES OF GROUND US FORCES

2019 ◽  
pp. 168-176
Author(s):  
D.B. Izyumov ◽  
E.L. Kondratyuk
Keyword(s):  
United States ◽  
Armed Forces ◽  
The United States ◽  
Educational Training ◽  
Us Army ◽  
The Us ◽  
Level Of Training ◽  
Army Personnel

The article discusses issues related to the development and use of training means and facilities in order to improve the level of training of US Army personnel. An overview of the main simulators used in the US Armed Forces at present is given, and the prospects for the development of the United States in this area are presented.

The Application of American Models to the Experiences and Outcomes of Canadian and International Students Studying in Canada

2005 ◽  
Vol 11 (1) ◽  
pp. 71-97 ◽  
Author(s):  
J. Paul Grayson
Keyword(s):  
Academic Achievement ◽  
International Students ◽  
Pilot Study ◽  
Student Outcomes ◽  
First Year ◽  
Program Satisfaction ◽  
Canadian Universities ◽  
General Utility ◽  
American Students ◽  
The Us

In order to test the general utility of models developed in the US for explaining university outcomes of Canadian and international students, a three year study is currently underway at four Canadian universities. As a first step in this research, a pilot study with two objectives was conducted at York University in Toronto. The first objective is to compare the experiences and outcomes of domestic and international students in their first year of study. The second objective is to test the applicability of a parsimonious general model of student outcomes derived from examinations of American students to Canadian and international students studying in Canada. The specific outcomes examined are academic achievement, credit completion, and program satisfaction in the first year of study.

Sign in / Sign up

Export Citation Format

Share Document