An application of photoelastic models to explain microfractures and joints in carbonate strata

1983 ◽  
Vol 20 (11) ◽  
pp. 1682-1693 ◽  
Author(s):  
U. Das Gupta ◽  
J. B. Currie
Keyword(s):  
Field Measurement ◽  
Carbonate Rocks ◽  
Laboratory Tests ◽  
Two Dimensional ◽  
Model Experiments ◽  
Tectonic Events ◽  
Photoelastic Model ◽  
History Of ◽  
Loading And Unloading

A two-dimensional photoelastic model constructed of Araldite and Hysol plastic is used to study how preferentially oriented microfractures originate in carbonate rocks. The model experiments suggest that orthogonal sets of microfractures should trend parallel to principal tectonic axes and that when diagenetic changes, such as dolomitization, are intense microfractures could be generated during both loading and unloading episodes in the history of a sedimentary basin.Petrographic observation of carbonates in the Turner Valley Formation illustrates the occurrence of microfractures. Laboratory tests demonstrate their preferred alignment in principal tectonic directions. Field measurement of joints in Turner Valley strata along Elbow River in southwest Alberta shows that the pattern of larger fractures can also consist of orthogonal fracture sets.The model experiments indicate therefore that development of preferentially oriented sets of microfractures in carbonates is probably a usual result of diagenetic and tectonic events that most of these rocks undergo during basinal evolution.

Evolving the Banded Radial Tire

1987 ◽  
Vol 15 (1) ◽  
pp. 30-41 ◽  
Author(s):  
E. G. Markow
Keyword(s):  
Finite Element ◽  
Wear Rate ◽  
Finite Element Modeling ◽  
Laboratory Tests ◽  
Rolling Resistance ◽  
Two Dimensional ◽  
Theoretical Discussion ◽  
Radial Tire ◽  
Puncture Resistance ◽  
Element Modeling

Abstract Development of the banded radial tire is discussed. A major contribution of this tire design is a reliable run-flat capability over distances exceeding 160 km (100 mi). Experimental tire designs and materials are considered; a brief theoretical discussion of the mechanics of operation is given based on initial two-dimensional studies and later on more complete finite element modeling. Results of laboratory tests for cornering, rolling resistance, and braking are presented. Low rolling resistance, good cornering and braking properties, and low tread wear rate along with good puncture resistance are among the advantages of the banded radial tire designs.

scholarly journals How Should We Categorize Approaches to the History of Political Thought?

2020 ◽  
Vol 83 (1) ◽  
pp. 91-114
Author(s):  
Adrian Blau
Keyword(s):  
Theoretical Analysis ◽  
Political Theory ◽  
Political Thought ◽  
Two Dimensional ◽  
History Of Political Thought ◽  
One Dimensional ◽  
History Of ◽  
New Framework

AbstractThis paper proposes a new framework for categorizing approaches to the history of political thought. Previous categorizations exclude much research; political theory, if included, is often caricatured. And previous categorizations are one-dimensional, presenting different approaches as alternatives. My framework is two-dimensional, distinguishing six kinds of end (two empirical, four theoretical) and six kinds of means. Importantly, these choices are not alternatives: studies may have more than one end and typically use several means. Studies with different ends often use some of the same means. And all studies straddle the supposed empirical/theoretical “divide.” Quentin Skinner himself expertly combines empirical and theoretical analysis—yet the latter is often overlooked, not least because of Skinner's own methodological pronouncements. This highlights a curious disjuncture in methodological writings, between what they say we do, and what we should do. What we should do is much broader than existing categorizations imply.

Late Wisconsinan glacial stratigraphy and history of southeastern Manitoba

1980 ◽  
Vol 17 (1) ◽  
pp. 19-35 ◽  
Author(s):  
James T. Teller ◽  
Mark M. Fenton
Keyword(s):  
Carbonate Rocks ◽  
Lacustrine Sediment ◽  
Precambrian Rock ◽  
Lake Agassiz ◽  
Rock Fragments ◽  
Lithostratigraphic Units ◽  
Stratigraphic Position ◽  
History Of ◽  
International Boundary ◽  
Late Wisconsinan

The history of Late Wisconsinan glaciation in southwestern Manitoba has been established by identifying and correlating ice-laid lithostratigraphic units in the subsurface. Five Late Wisconsinan tills are defined on the basis of their texture, mineralogic composition, and stratigraphic position. These new formations are, from youngest to oldest, Marchand, Whitemouth Lake, Roseau, Senkiw, and Whiteshell Formations.Late Wisconsinan ice first invaded southeastern Manitoba 22 000 to 24 000 years ago. This Laurentide glacier advanced from the northeast across the Precambrian Shield and deposited the sandy Whiteshell and Senkiw tills, which contain abundant Precambrian rock fragments and minerals and few Paleozoic carbonate grains. Shortly after this, Keewatin ice advanced from the northwest over Paleozoic carbonate rocks, depositing the loamy carbonate-rich Roseau Formation throughout most of the area. This ice remained over southeastern Manitoba until after 13 500 years ago, when it rapidly retreated northward with Lake Agassiz on its heels. Two brief glacial readvances occurred. The first overrode Lake Agassiz lacustrine sediment as far south as central North Dakota shortly after about 13 000 years ago. The clayey Whitemouth Lake till was deposited in southern Manitoba at this time. After a rapid retreat, the ice briefly pushed southward over southeastern Manitoba about 12 000 years ago to just south of the International Boundary. The sandy carbonate-rich Marchand Formation was deposited at this time as the ice overrode its own sandy outwash. By 11 000 years ago, ice had disappeared from southeastern Manitoba.

Loving Ebola-chan: Internet memes in an epidemic

2016 ◽  
Vol 39 (3) ◽  
pp. 341-356 ◽  
Author(s):  
Olivia Rose Marcus ◽  
Merrill Singer
Keyword(s):  
Infectious Disease ◽  
Digital Age ◽  
Structural Approach ◽  
The Internet ◽  
Social Response ◽  
Coping Mechanism ◽  
Two Dimensional ◽  
Fear Response ◽  
Cultural Artifact ◽  
History Of

In this article, the authors provide a layered analysis of Ebola-chan, a visual cultural artifact of the 2014–2015 Ebola outbreak. Rather than considering her as a two-dimensional anime character (i.e. as a simple iconic coping mechanism and/or a fear response), this recent Internet meme is analyzed using an integrated semiotic and structural approach that involves discussion of the genesis of disaster humor in light of the changing world of the Internet, the history of anthropomorphism of disease, and the biosocial nature of an infectious disease epidemic. Our analysis is designed to advance both the anthropology of the Internet and the anthropology of infectious disease. As a multi-vocal symbol with different meanings for different audiences, Ebola-chan represents a social response to a lethal epidemic in the digital age.

CAT SCRATCH SYNDROME

PEDIATRICS ◽  
1952 ◽  
Vol 10 (3) ◽  
pp. 311-318
Author(s):  
WILLIAM J. WATERS ◽  
SEYMOUR S. KALTER ◽  
JOHN T. PRIOR
Keyword(s):  
Skin Test ◽  
Laboratory Tests ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Clinical Laboratory ◽  
Clinical Course ◽  
Diagnostic Value ◽  
Clinical Findings ◽  
Pathologic Findings ◽  
History Of

The clinical, laboratory and pathologic findings of a series of cases of cat scratch syndrome have been reviewed. In spite of a variable clinical course, certain features associated with a selected group of laboratory tests appear to be constant enough to be of diagnostic value. A history of contact with a cat and/or scratch which is usually associated with a peripheral skin lesion, lack of lymphangitis, presence of regional lymphadenopathy with tenderness to palpation are the most constant clinical findings. Fever, so frequently emphasized as a characteristic clinical sign, may be extremely variable in type and duration or entirely absent. A skin test with cat scratch antigen has been positive in all cases. Lacking this antigen, a negative Frei skin test in conjunction with a positive complement fixation test (Lygranum C. F.) is suggestive evidence for the diagnosis. With positive evidence from the above data, biopsy of an affected gland with its relatively nonspecific pathologic picture is not considered essential for the establishment of the diagnosis of cat scratch syndrome.

Investigation of the causes of damage to freight cars during disbanding on non-mechanized sorting slides and development of measures to prevent them

2021 ◽  
pp. 4-13
Author(s):  
S. V. Tankeev ◽  
◽  
A. E. Kolodin ◽  
V. B. Sverdlov ◽  
A. V. Nazarov ◽  
...  
Keyword(s):  
Low Power ◽  
Coefficient Of Friction ◽  
Damage Assessment ◽  
Laboratory Tests ◽  
Rolling Stock ◽  
Third Body ◽  
Normative Documents ◽  
The Coefficient Of Friction ◽  
Loading And Unloading ◽  
The Relationship

The damage assessment of freight cars during shunting and loading and unloading operations was made. The need to review the normative documents regulating the relationship between the owners of rolling stock, owners of non-public tracks and the carrier is noted. The reasons for formation of damage on the wheel pairs of freight cars when disbanding on low-power sorting slides are considered. The conditions for ensuring the deceleration of detachments on non-mechanized sorting slides without damaging the wheels are determined. The analysis of methods for ensuring braking on low-power slides is carried out. A method was chosen to ensure the wheel set rotation by introducing a third body between the rubbing surfaces during the braking of cars, which will take over a part of the resulting heat flow, reducing the temperature and increasing the coefficient of friction in the «wheel-rail» contact zone. A method is proposed to provide braking on the non-mechanized sorting slide during shoe braking by applying a friction compound to a non-working rail. Laboratory tests were carried out, which showed that the introduction of a friction additive can achieve the necessary coefficient of friction to comply with the standard parameters of deceleration of the car in the braking zone.

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