Optimising the locations of thermally sensitive equipment in an aircraft crown compartment

A Design of Experiments (DoE) analysis was undertaken to generate a list of configurations for CFD numerical simulation of an aircraft crown compartment. Fitted regression models were built to predict the convective heat transfer coefficients of thermally sensitive dissipating elements located inside this compartment. These are namely the SEPDC and the Route G. Currently they are positioned close to the fuselage and it is of interest to optimise the heat transfer for reliability and performance purposes. Their locations and the external fuselage surface temperature were selected as input variables for the DoE. The models fit the CFD data with values ranging from 0.878 to 0.978, and predict that the optimum locations in terms of heat transfer are when the elements are positioned as close to the crown floor as possible ( and ?min. limits), where they come in direct contact with the air flow from the cabin ventilation system, and when they are positioned close to the centreline ( and ?CL). The methodology employed allows aircraft thermal designers to optimise equipment placement in confined areas of an aircraft during the design phase. The determined models should be incorporated into global aircraft numerical models to improve accuracy and reduce model size and computational time. © 2012 Elsevier Masson SAS. All rights reserved.

Effect of the crown design and interface lute parameters on the stress-state of a machined crown-tooth system: A finite element analysis

The effect of preparation design and the physical properties of the interface lute on the restored machined ceramic crown-tooth complex are poorly understood. The aim of this work was to determine, by means of three-dimensional finite element analysis (3D FEA) the effect of the tooth preparation design and the elastic modulus of the cement on the stress state of the cemented machined ceramic crown-tooth complex. The three-dimensional structure of human premolar teeth, restored with adhesively cemented machined ceramic crowns, was digitized with a micro-CT scanner. An accurate, high resolution, digital replica model of a restored tooth was created. Two preparation designs, with different occlusal morphologies, were modeled with cements of 3 different elastic moduli. Interactive medical image processing software (mimics and professional CAD modeling software) was used to create sophisticated digital models that included the supporting structures; periodontal ligament and alveolar bone. The generated models were imported into an FEA software program (hypermesh version 10.0, Altair Engineering Inc.) with all degrees of freedom constrained at the outer surface of the supporting cortical bone of the crown-tooth complex. Five different elastic moduli values were given to the adhesive cement interface 1.8 GPa, 4 GPa, 8 GPa, 18.3 GPa and 40 GPa; the four lower values are representative of currently used cementing lutes and 40 GPa is set as an extreme high value. The stress distribution under simulated applied loads was determined. The preparation design demonstrated an effect on the stress state of the restored tooth system. The cement elastic modulus affected the stress state in the cement and dentin structures but not in the crown, the pulp, the periodontal ligament or the cancellous and cortical bone. The results of this study suggest that both the choice of the preparation design and the cement elastic modulus can affect the stress state within the restored crown-tooth complex.

Scandinavia and its confines, in which are the Kingdoms of Sweden, Denmark, and Norway, divided into their principall provinces viz. Under the crown of Sweden, those of Gothland, Sweden, Lapland, Finland, Ingria, and Livonia; Under the crown of Denmark, those of Jutland, Sleswick, Zealand, Fyonie, &c. In Denmark those of Agger, Dronthem, and Wardhous, in Norway /

1 kartta :, käsinvär. ;, 56,4 x 86,7 cm, lehti 62,5 x 91,5 cm

L'ex Crown Princess d'Allemagne [Cecilie, épouse du fils de Guillaume II, Friedrich Wilhelm] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59371

The crystal and molecular structure of 18-Crown-6 HgC12 and 18-Crown-6 Cdc12

Hg(18-Crown-6)C12 and Cd(18-Crown-6)C12 are isostructura1, space group Cl~ Z = 2. For the mercury compound, a = 10.444(2) A° , b = 11. 468(1) A° , c = 7.754(1) A° , a = 90.06(1)°, B = 82.20(1)°, Y = 90.07(1)°, Dobs = 1.87, Dca1c = 1.93, V = 920.05 13, R = 4.66%. For the cadmium compound, 000 a = 10.374(1) A, b = 11.419(2) A, c = 7.729(1) A, a = 89.95(1)°, B = 81.86(2)°, Y = 89.99(1)°, Dobs = 1.61, Dcalc = 1.64, V = 906.4613, R = 3.95%. The mercury and cadmium ions exhibit hexagonal bipyramidal coordination, with the metal ion located on a centre of symmetry in the plane of the oxygen atoms. The main differences between the two structures are an increase in the metal-oxygen distance and a reduction in the metalchloride distance when the central ion changes from Cd2+ to Hg2+. These differences may be explained in terms of the differences in hardness or softness of the metal ions and the donor atoms.

Crown timber regulations

Crown timber regulations which include: 2 double-sided printed pages issued by the Department of Crown Lands (2 copies). Included with this are 3 printed slips of paper. 2 of these are Order and Regulations by S. Richards, Commissioner of Crown Lands, dated May 28, 1869 and 1 is a notice of sale of timber berths dated Aug.1, 1872 by Richard Wm. Scott, commissioner, 1869, 1872.

Letter to S.D. Woodruff from Thomas H. Johnson of the Department of Crown Lands

Letter to S.D. Woodruff from Thomas H. Johnson of the Department of Crown Lands replying to Mr. Woodruff’s inquiry about the boundaries of berth 192, Dec. 8, 1877.

Certificate from the Accounts Branch of Crown Lands, Ontario

Certificate from the Accounts Branch of Crown Lands, Ontario in receipt of $72 for renewal of license made out to S.D. Woodruff and signed by Thomas H. Johnson, Assistant Commissioner, May 23, 1881.

Notice from the Crown Lands Department of Ottawa that the lands on Long Point, Lake Erie would be offered at public auction on May 4, 1866

Notice from the Crown Lands Department of Ottawa that the lands on Long Point, Lake Erie would be offered at public auction on May 4, 1866. This is attached to a small newspaper clipping with the same information, dated April 20, 1866.

Explanation of the Land Surrendered to the Crown by the Six Nations Indians for Mr. Dickson

Explanation of the Land Surrendered to the Crown by the Six Nations Indians for Mr. Dickson: 1 handwritten page explaining the Six Nations surrender of land to the Crown in order to allow the Crown to transfer the land to Mr. Dickson to compensate him for legal fees. [This is not an older document. It was possibly written by the Niagara Historical Society], n.d.

A crown for our queen

UANL