UNT Libraries Government Documents Department - 24,745 Matching Results

Search Results

Newton's Method

Description: Newton's method plays a central role in the development of numerical techniques for optimization. In fact, most of the current practical methods for optimization can be viewed as variations on Newton's method. It is therefore important to understand Newton's method as an algorithm in its own right and as a key introduction to the most recent ideas in this area. One of the aims of this expository paper is to present and analyze two main approaches to Newton's method for unconstrained minimization: the line search approach and the trust region approach. The other aim is to present some of the recent developments in the optimization field which are related to Newton's method. In particular, we explore several variations on Newton's method which are appropriate for large scale problems, and we also show how quasi-Newton methods can be derived quite naturally from Newton's method.
Date: February 1982
Creator: Moré, Jorge J. & Sorensen, D. C.

Newton's Method with a Model Trust-Region Modification

Description: A modified Newton method for unconstrained minimization is presented and analyzed. The modification is based upon the model trust region approach. This report contains a thorough analysis of the locally constrained quadratic minimizations that arise as sub-problems in the modified Newton iteration. Several promising alternatives are presented for solving these sub-problems in ways that overcome certain theoretical difficulties exposed by this analysis. Very strong convergence results are presented concerning the minimization algorithm. In particular, the explicit use of second-order information is justified by demonstrating that the iterates converge to a point that satisfies the second-order necessary conditions for minimization. With the exception of very pathological cases this convergence occurs whenever the algorithm is applied to problems with continuous second partial derivatives.
Date: September 1980
Creator: Sorensen, D. C.

The Nichols Wing Cutting Equipment

Description: Described here is wing cutting equipment for the economical production of metal wings for wind tunnel models. The machine will make any size of constant-section wing or strut up to one-sixth inch chord by 36-inch span and up to a thickness of one and one-quarter inches. It cuts a smooth, true model that is accurate to within two-thousandths of an inch on any ordinate. The holding jaws are so designed as to leave the model free of chip marks, and the only hand finishing necessary after the cutting is a rub with amunite to remove burrs. The actual change on ordinate in this finishing rub is less than .0002 inches.
Date: December 1923
Creator: Ford, James B.

Nickel and Its Alloys

Description: From Abstract: "This monograph reviews available information on the production, properties, and uses of high-purity and commercial forms of nickel, and on the properties and applications of its important alloys, both ferrous and non ferrous."
Date: May 1968
Creator: Rosenberg, Samuel J.

Nickel-Copper Deposit at Funter Bay, Admiralty Island, Alaska

Description: From abstract: The nickel-copper deposit near the north end of Admiralty Island, about 18 miles in an airline west of Juneau, in southeastern Alaska, consists of a basic sill which averages somewhat more than 100 feet in thickness. The sill, which dips eastward, is intrusive into a thick sequence of phyllite and various types of schist. The rock of the sill consists principally of the silicate minerals labradorite and olivine, but it also contains magnetite and the sulfides pyrrhotite, pentlandite, and chalcopyrite. It assays, on the average, about 0.34 percent nickel and 0.35 copper, which are doubtless mostly in the pentlandite and chalcopyrite respectively but are probably constituents of other minerals also. A significant proportion of nickel and copper is probably contained in the olivine and perhaps in the pyrrhotite.
Date: 1942
Creator: Reed, John C.

Nickel-Copper Deposit at Snipe Bay, Baranof Island, Alaska

Description: Abstract: At Snipe Bay, on the outer coast of Baranof Island, about 46 miles southeast of Sitka in southeastern Alaska, is a nickelcopper deposit that consists of a mass of basic rock intruded into quartzite and quartz schist. Neither the size nor the grade of the deposit is adequately known. Natural exposures and those in a few prospect openings indicate that to an assumed depth of about 130 feet below the lowest point on the outcrop there is a reserve of about 430,000 tons of low-grade nickelbearing material, which, to judge from available assays and from comparison with similar material from other places, probably does not contain more than 0.3 percent each of nickel and copper. The deposit thus appears too small and of too low grade to permit the recovery of the nickel and copper except at a considerable financial loss; but as the location is favorable for largescale, low-cost development, further prospecting may be justified, in the hope that a moderate amount of surface stripping, plus a few diamond-drill holes, might indicate that the deposit is larger, and possibly of higher grade, than it is safe to infer from the available data.
Date: 1942
Creator: Reed, John C. & Gates, George O.

Nickel-Copper Deposits on the West Coast of Chichagof Island, Alaska

Description: From abstract: On the west coast of Chichagof Island, southeastern Alaska, are three nickel-copper deposits that consist of norite containing the sulfide minerals pyrrhotite, pentlandite, and chalcopyrite. The deposits are within less than a mile of each other and are, by water, 160 miles southwest of Juneau and 70 miles northwest of Sitka. The norite is part of a stock, about 5 square miles of which is above sea level. Other rocks of the stock are amphibolite, amphibolitic norite, gabbro, diorite, quartz diorite, monzonite, granite, pegmatites, quartz veins, and schist inclusions. The stock is intrusive into a Lower Cretaceous (?) graywacke formation and an Upper Triassic (?) greenstone formation, both of which are now metamorphosed to schist.
Date: 1942
Creator: Pecora, W. T.

Nickel Deposit Near Gold Hill, Boulder County, Colorado

Description: From Introduction: "Scattered throughout the Colorado Front Range, there are many small copper deposits, believed to be of pre-Cambrian age. The have been widely prospected but have produced little or no ore. In one of these, the Copper King mine, near Gold Hill, Colo., nickel was discovered in 1930, and development in the following years has exposed some 25,000 tons of ore containing from 2 to 3 percent of nickel. No other nickel deposit is known in the Front Range, but a somewhat similar deposit has been opened in Gem mine, near Canon City and about 120 miles south of Gold Hill."
Date: 1942
Creator: Goddard, Edwin N. & Lovering, T. S.

Nickel deposit near Riddle, Douglas County, Oregon

Description: From Introduction: "The Riddle nickel deposit is on Nickel Mountain, also called Piney Mountain, about 5 miles northwest of Riddle, Douglas Country, Oreg. (fig. 20). The deposit is an unevenly distributed surficial blanket, containing the nickel silicate garnierite, which rests upon peridotitic rocks on the western, southern, and southeastern slopes of the mountain above an elevation of 2,000 feet. It is on the Southern Pacific Railroad, and it is about 230 miles by highway south of Portland. A poorly conditioned dirt road about 5 miles long connects the town with the nickel deposit."
Date: 1942
Creator: Pecora, William T. & Hobbs, S. Warren

The nickel dip : a radioisotope study of metallic deposits in porcelain enameling

Description: Report discussing the use of radioisotope tracer techniques to study the following phenomena: the effect of nickel dip on the deposition of cobalt metal during firing of a cobalt-bearing ground coat, the effect of surface pretreatment on the amount and distribution of nickel deposited from nickel dip on enameling iron, and the effect of application and firing of cobalt-free and cobalt-bearing enamels on the chemical form and physical distribution of nickel previously deposited on enameling iron by the nickel dip.
Date: February 1956
Creator: Richmond, Joseph C.; Kirkpatrick, Harry B. & Harrison, William N.

Nickel-gold deposit near Mount Vernon, Skagit County, Washington

Description: From Introduction: "The Mount Vernon nickel-gold deposit is 4 1/2 miles southeast of the city of Mount Vernon, Skagit County, Wash. The writers believe that the nickel was originally present in the serpentinized peridotite and that it was dissolved and redistributed by ascending hydrothermal gold-bearing solutions while the serpentine was being altered into the silica-carbonate rock."
Date: 1941
Creator: Hobbs, S. W. & Pecora, W. T.

The Nicrosil versus Nisil Thermocouple: Properties and Thermoelectric Reference Data

Description: From Abstract: "This monograph deals with the formulation and development of the new highly stable nickel-base thermocouple alloys Nicrosil (Ni-14.2Cr-1.4Si) and Nisil (Ni-4.4Si-0.1Mg) under the leadership of the Materials Research Laboratories (MRL) of the Australian Government of Defence, and their standardization by the National Bureau of Standards (NBS) of the U.S. Department of Commerce."
Date: April 1978
Creator: Burley, Noel A.; Powell, Robert L.; Burns, George W.; Scroger, Margaret G.; Burns, George W. & Scroger, Margaret G.

Nieuport-Astra Parachute Contest

Description: Report presenting a description of a parachute design contest. The object of this contest was to obtain a parachute of light weight and small bulk, suitable for airplanes. The primary areas of focus were safety, ability to be installed on airplanes, speed, materials, and behavior of the parachutes in the air.
Date: October 1923
Creator: Philippe, J.

Night Flying

Description: Dr. Warner examines the utility and economy of flying at night when flying passengers. Some of the points discussed include lighted landing fields, the possibility of using airships, and the cost of landing fields.
Date: May 1922
Creator: Warner, Edward P.

Niobium (Columbium) and Titanium at Magnet Cove and Potash Sulphur Springs, Arkansas

Description: From Abstract: Niobium (columbium) and titanium occur in several minerals and rocks of the Magnet Cove and Potash Sulphur Springs areas. Niobium is in demand for use in high-temperature and noncreep steels; titanium metal is becoming an important structural material. The Magnet Cove and Potash Sulphur Springs areas are in central Arkansas between the communities of Malvern and Hot Springs. They are underlain by similar alkalic igneous complexes consisting of nepheline syenite, more basic alkalic rocks, and calcite rock or carbonatite. The igneous rocks transect sedimentary rocks of Paleozoic age and were truncated by erosion of Late Cretaceous age.
Date: 1954
Creator: Fryklund, Verne Charles, Jr.; Harner, R. S. & Kaiser, E. P.

Niobium Phase Diagrams

Description: The following report is the final technical report on a series of reports under contract AT(11-1)-515, titled "Niobium Phase Diagrams", covering the period from April 15, 1957 to April 16, 1960.
Date: May 15, 1960
Creator: Elliott, Rodney P. & Komjathy, Steven

Niobium Phase Diagrams : Manuscript Report on Niobium-Carbon System

Description: Abstract: "The niobium-carbon system has been determined by X-ray and metallographic examination of sintered and arc-cast alloys. Two carbides exist: hexagonal Nb2C with a limited range of homogeneity, and cubic NbC with a solubility range from 8.25 to 10.25 weight per cent carbon. Dilute alloys freeze by eutectic reaction at 2230 C. The solubility of carbon in niobium is 0.80 at the eutectic temperature, but this decreases rapidly with temperature. Metallographic evidence indicates a peritectic reaction between melt, Nb2C, and NbC; alloys richer in carbon than NbC freeze by eutectic reaction."
Date: May 6, 1959
Creator: Elliott, Rodney P.

Niobium Phase Diagrams : Manuscript Report on Niobium-Oxygen System

Description: Abstract: "The niobium-oxygen equilibrium has been determined by metallographic examination of arc-cast alloys made of electron-gun-refined niobium metal and special purity niobium pentoxide. Two intermediate oxides, NbO and NbO2, melt without decomposition at 1945 C and 1915 C, respectively. Eutectic reactions exist between niobium and NbO and 1915 C and between NbO and NbO2 at 1810 C. Experimental supports a peritectic reaction between NbO2 and Nb2O5 1510 C. The maximum solid solubility of oxygen in niobium metal is 0.72 weight per cent."
Date: April 27, 1959
Creator: Elliott, Rodney P.

Nitration Reactions of Shell Spray Base under Purex Waste Recovery Process Conditions

Description: Abstract: "Experiments were performed to characterize the types of nitro compounds that might be formed by reaction of Shell Spray Base with nitric acid, to determine the extent of their formation, if any, and their path under conditions of nitric acid recovery in the Purex Process. It is concluded that the instability of Shell Spray Base to nitration, under conditions to prevail in the plant, presents neither a disposal problem nor a safety problem."
Date: December 5, 1952
Creator: Wagner, R. F.

Nitrided-steel piston rings for engines of high specific power

Description: Report presenting testing of several designs of nitrided-steel piston rings under variable conditions of output. Testing indicated the importance of good surface finish and conformity of the ring to the bore. Results regarding temperature tests, single-cylinder-engine tests, and multicylinder-engine tests are provided.
Date: April 1944
Creator: Collins, John H., Jr.; Bisson, Edmond E. & Schmiedlin, Ralph F.