scholarly journals Weak asymmetric interspecific aggression and divergent habitat preferences at an elevational contact zone between tropical songbirds

Ibis ◽  
2019 ◽  
Vol 162 (3) ◽  
pp. 814-826 ◽  
Author(s):  
Samuel E. I. Jones ◽  
Joseph A. Tobias ◽  
Robin Freeman ◽  
Steven J. Portugal
Keyword(s):  
Contact Zone ◽  
Habitat Preferences ◽  
Interspecific Aggression

Tire Treadwear — A Comprehensive Evaluation of the Factors: Generic Type, Aspect Ratio, Tread Pattern, and Tread Composition Part IV: Laboratory Measurement of Mechanical Properties and Mechanical Actions of Tires Relating to Treadwear

1986 ◽  
Vol 14 (4) ◽  
pp. 264-291
Author(s):  
K. L. Oblizajek ◽  
A. G. Veith
Keyword(s):  
Mechanical Properties ◽  
Shear Stress ◽  
Contact Zone ◽  
Flexural Rigidity ◽  
Comprehensive Evaluation ◽  
Shear Stiffness ◽  
Shear Stresses ◽  
Lateral Shear ◽  
Band Bending ◽  
Tread Rubber

Abstract Treadwear is explained by specific mechanical properties and actions of tires. Rubber shear stresses in the contact zone between the tire and the road become large at large slip angles. When normal stresses are insufficient to prevent sliding at the rear of the footprint, wear occurs at a rate that depends on test severity. Two experimental approaches are described to relate treadwear to tire characteristics. The first uses transducers imbedded in a simulated road surface to obtain direct measurements of contact stresses on the loaded, freely-rolling, steered tires. The second approach is developed with the aid of a simple carcass, tread-band, tread-rubber tire model. Various tire structural configurations; characterized by carcass spring rate, edgewise flexural band stiffness, and tread rubber shear stiffness; are simulated and lateral shear stress response in the contact zone is determined. Tires featuring high band stiffness and low carcass stiffness generate lower lateral shear stress levels. Furthermore, coupling of tread-rubber stiffness and band flexural rigidity are important in determining level of shear stresses. Laboratory measurements with the described apparatus produced values of tread-band bending and carcass lateral stiffness for several tire constructions. Good correlation is shown between treadwear and a broad range of tire stiffness and test course severities.

Stibnite vein from Dębowina near Bardo (polish Sudetes)

2013 ◽  
Vol 2 (1) ◽  
pp. 28-33
Author(s):  
Piotr Kotula
Keyword(s):  
Contact Zone

Abstract In the contact zone of the Bardo Structure and Kłodzko-Złoty Stok Intrusion and Kłodzko Metamorphic, metasomatic orebearing quartz-carbonate veins rich in Sb, Zn, Cu, Ag, Au, Pb are present. In 1771 the mine ,,Reiche Silber Gluck” within stibnite vein was founded in Dębowina near Bardo. Its entrance was discovered again in 2007. The stibnite vein is mainly build of stibnite and sphalerite and of quartz and dolomite rich in Mn. Stibnite crystallizes as columnar or forming radiate centres and aciculars. Its crystals reach size to 2 mm. Sphalerite appears as individual anhedral and polymineralic grained concentrations reaching size to 2,5 mm. Earlier pyrite and arsenopyrite crystallized - they occur locally in this deposit. There were found also in the deposit tetrahedrite rich in Ag, what wasn't reported earlier in studies from the mine in Dębowina.

Macrotylus (Alloeonycha) xantii Günther, 2018, (Hemiptera: Miridae, Phylinae) new to Portugal, with a description of the female

2019 ◽  
Vol 155 (1) ◽  
pp. 65-69
Author(s):  
Stuart Foster
Keyword(s):  
Habitat Preferences ◽  
Single Male ◽  
Male Specimen ◽  
Sandy Substrate

The plant bug Macrotylus (Alloeonycha) xantii Günther, 2018, is reported as new to Portugal from the Algarve. This species was described from a single male specimen captured on dry grass in a calcareous area of Andalusia, Spain. The female was previously unknown, so the presence of both sexes in reasonable numbers on sparsely vegetated sandy substrate in Portugal extends its known range and habitat preferences, and has enabled the female to be described.

Distribution, systematics and nomenclature of the three taxa of Common Stonechats (Aves, Passeriformes, Muscicapidae, Saxicola) that breed in the Caucasian region

2020 ◽  
Vol 29 (1) ◽  
pp. 33-57
Author(s):  
V.M. Loskot ◽  
G.B. Bakhtadze
Keyword(s):  
Geographic Distribution ◽  
Habitat Preferences ◽  
Junior Synonym ◽  
Type Locality ◽  
Diagnostic Features ◽  
Western Turkey ◽  
Geographical Variations ◽  
History Of ◽  
The Individual ◽  
North Western

Geographic distribution and habitat preferences of Saxicola rubicola rubicola (Linnaeus, 1766), S. maurus variegatus (S.G. Gmelin, 1774), and S. m. armenicus (Stegman, 1935) inhabiting the Caucasian Isthmus and adjacent areas are described in detail. We examined the individual, sexual, age, seasonal and geographical variations of seven main diagnostic features of both plumage and morphometrics (exactly, the length of wing and tail) using 381 skin specimens. Substantially improved diagnoses of S. m. variegatus and S. m. armenicus are provided. After a thorough examination of the materials and history of the expedition of Samuel Gmelin in 1768–1774, and his description of Parus variegatus, it was concluded that the type locality of this taxon was the vicinity of Shamakhi in Azerbaijan not Enzeli in North-Western Turkey. It is also shown the fallacy of the recently proposed attribution of the holotype of the northern subspecies S. m. variegatus to the southern taxon S. m. armenicus and synonymisation of these names, as well as the replacement of the name S. m. variegatus by its junior synonym S. m. hemrichii Ehrenberg, 1833 for the northern subspecies.

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