scholarly journals A fine-grained analysis of a Monk parakeet (Myiopsitta monachus) nest suggests a nonhomogeneous internal structure

2021 ◽  
pp. 33-36
Author(s):  
Corrado Battisti ◽  
Giuliano Fanelli
Keyword(s):  
Central Italy ◽  
Breeding Site ◽  
Monk Parakeet ◽  
Fine Grained ◽  
Nest Chamber ◽  
Myiopsitta Monachus ◽  
Large Fluctuations ◽  
Fine Grained Structure ◽  
Hordeum Leporinum ◽  
Internal Chamber

We report first data on the fine-grained structure (branch diameter, length and diversity) in three different sectors [core (central side), buffer (peripheral side), and nest chamber)] of a nest of Monk Parakeets (Myiopsitta monachus) from a non-native breeding site located in an urban park (Rome, central Italy). The central core sector was characterized by longer and thicker branches capable of supporting the nest. The peripheral part (buffer) was characterized by less long and less thick branches with the function of completing the structure. Branches building the nest chamber were shorter and less thick but very diversified in size, because they included both small branches supplied inside the chamber and longer branches covering it. This diversification of the internal chamber (nest chamber) could be functional to maintain stable temperatures of incubator chambers compared to large fluctuations outside the nest. The presence of leaves of herbaceous species (Hordeum leporinum) could play a bactericidal role for the nest plant material.

scholarly journals Differences between the outer and inner structure of the Short-toed treecreeper’s (Certhia brachydactyla Brehm, 1820) nest in an urban area

2021 ◽  
pp. 183-187
Author(s):  
Corrado Battisti ◽  
Giuliano Fanelli
Keyword(s):  
Urban Area ◽  
Central Italy ◽  
Bird Species ◽  
Pinus Pinea ◽  
Plant Roots ◽  
Urban Park ◽  
Nest Structure ◽  
Fine Grained ◽  
Fine Grained Structure ◽  
Sand Dust

We reported the first available data on the fine-grained structure of the short-toed treecreeper’s (Certhia brachydactyla Brehm, 1820) nest located in an urban park of Rome (central Italy). The outer structure was characterized by a high percentage of conifer (Pinus pinea) needles, which are significantly longer than other branches and twigs. Pine needles are widely available in urban parks, and being more flexible and easily detachable, may contribute to the support of the outer nest structure provided by other linear components (i.e., twigs/branches). Moreover, their aromatic terpenes may control nest parasites. In contrast, the internal cup lining was composed of a very light and heterogeneous set of components (bird feathers of at least one synanthropic bird species: Streptopelia decaocto), vegetable fluff, grass leaves, shrubs and trees, moss, sand, dust, and plant roots, i.e., all the materials largely used in bird nests because of their insulative qualities and thermoregulation functions. Although the internal cup lining was more heterogeneous in composition, the total weight of the outer nest was significantly heavier (>65% on the total nest weight).

Monk Parakeet (Myiopsitta monachus)

1998 ◽  
Author(s):  
Mark F. Spreyer ◽  
Enrique H. Bucher
Keyword(s):  
Monk Parakeet ◽  
Myiopsitta Monachus

scholarly journals Fine‐scale genetic structure reflects limited and coordinated dispersal in the colonial monk parakeet, Myiopsitta monachus

2021 ◽  
Author(s):  
Francesca S. E. Dawson Pell ◽  
Juan Carlos Senar ◽  
Daniel W. Franks ◽  
Ben J. Hatchwell
Keyword(s):  
Genetic Structure ◽  
Fine Scale ◽  
Monk Parakeet ◽  
Myiopsitta Monachus

scholarly journals Effect of Microstructure and Notches on the Fracture Toughness of Medium Carbon Steel

1970 ◽  
Vol 3 (1) ◽  
pp. 15-22 ◽  
Author(s):  
SK Nath ◽  
Uttam Kr Das
Keyword(s):  
Fracture Toughness ◽  
Carbon Steel ◽  
Tensile Specimen ◽  
Medium Carbon Steel ◽  
Notch Angle ◽  
Medium Carbon ◽  
Fine Grained ◽  
Keywords Fracture ◽  
Fine Grained Structure ◽  
Marine Engineering

Fracture toughness (K1C) of medium carbon steel (0.5% C) has been determined by round notched tensile specimen. Two notch diameters (5.6mm and 4.2mm) and three notch angles (α) namely 45°, 60° and 75° have been used to observe the effect of notch diameters and notch angle on fracture toughness of the steel. By heat treatment the microstructure of the steel is also varied and its effect on the fracture toughness is also observed. It has been found that fine grained structure improves fracture toughness. Lower notch diameter and higher notch angle show higher value of K1C. Keywords: Fracture toughness, microstructure, notch, heat treatmentDOI: 10.3329/jname.v3i1.925 Journal of Naval Architecture and Marine Engineering 3(2006) 15-22

A Study on Nanocrystalline Nickel Parts Prepared by Jet Electrodeposition

2010 ◽  
Vol 37-38 ◽  
pp. 64-67
Author(s):  
Jin Song Chen ◽  
Yin Hui Huang ◽  
Bin Qiao ◽  
Jian Ming Yang ◽  
Yi Qiang He
Keyword(s):  
Dimensional Accuracy ◽  
Processing Parameters ◽  
X Ray Diffraction ◽  
Scanning Microscope ◽  
Nanocrystalline Nickel ◽  
X Ray ◽  
Fine Grained ◽  
Average Grain Size ◽  
Jet Electrodeposition ◽  
Fine Grained Structure

The principles of jet electrodeposition orientated by rapid prototyping were introduced. The nanocrystalline nickel parts with simple shape were fabricated using jet electrodeposition. The microstructure and phase transformation of nanocrystalline nickel were observed under the scanning microscope and X-ray diffraction instrument. The results show that the jet electrodeposition can greatly enhance the limited current density, fine crystalline particles and improve deposition quality. The nickel parts prepared by jet electrodeposition own a fine-grained structure (average grain size 25.6nm) with a smooth surface and high dimensional accuracy under the optimum processing parameters.

Electrodeposited Nanocrystalline Nickel Parts

2012 ◽  
Vol 201-202 ◽  
pp. 1102-1105
Author(s):  
Jin Song Chen ◽  
Jian Ming Yang
Keyword(s):  
Rapid Prototyping ◽  
Dimensional Accuracy ◽  
Processing Parameters ◽  
Nanocrystalline Nickel ◽  
Fine Grained ◽  
Average Grain Size ◽  
Machined Parts ◽  
Jet Electrodeposition ◽  
Fine Grained Structure ◽  
Metallic Parts

The principles of jet electrodeposition orientated by rapid prototyping were introduced , The nanocrystalline nickel parts with simple shape were fabricated using jet electrodeposition oriented by rapid prototyping. The microstructure and phase transformation of nanocrystalline nickel were observed under the scanning microscope and X-ray diffraction instrument . The results show that the successful fabrication of metallic parts demonstrates the potential of the jet electrodeposition process for prototyping technology . The jet electrodeposition can greatly enhance the limited current density, fine crystalline particles and improve deposition quality. The nickel parts prepared by jet electrodeposition own a fine-grained structure( average grain size 25.6nm) with a smooth surface and high dimensional accuracy under the optimum processing parameters..The dimensional accuracy as well as the surface quality of metallic parts and tools manufactured using jet electrodeposition techniques still lag far behind those of conventionally machined parts.

Structure, Texture and Mechanical Properties through the Section of the Hot-Extruded Tube of Titanium Alloy PT-1M

2020 ◽  
Vol 989 ◽  
pp. 139-144 ◽  
Author(s):  
F.V. Vodolazskiy ◽  
N.A. Barannikova ◽  
Anatoly G. Illarionov
Keyword(s):  
Titanium Alloy ◽  
Extrusion Direction ◽  
Hot Extrusion ◽  
Tangential Direction ◽  
Primary Recrystallization ◽  
Recrystallization Temperature ◽  
Fine Grained ◽  
Surface Areas ◽  
Α Phase ◽  
Fine Grained Structure

The study considers the formation of the structure, texture, and hardness of hot extruded tube of titanium alloy PT-1M. It is shown that hot extrusion at 840 °C, which is higher than the α-phase recrystallization temperature, results to the development of dynamic and primary recrystallization processes and ensures the formation of homogeneous and fine-grained structure through-out the cross section with a two-component tangential texture (0001)TD<100>ED+(0001)TD<110>ED (TD – tangential direction, ED – extrusion direction) and hardness of 155 HV. It has been established that a higher cooling rate of the surface areas of the tube after extrusion results to a less active development of recrystallization processes, which lead to the formation of a finer granular structure near the outer surface. This weakens recrystallization component of (0001)TD<110>ED, compared to other areas of the tube.

Sign in / Sign up

Export Citation Format

Share Document