Tests show that aluminum welds are improved by bead removal

Tests with 2218-T87 aluminum alloy plate indicate improvements in strength, ductility, fatigue properties, and burst pressure result when one or both of the top and bottom weld beads are removed. There is, however, a drop in yield strength. The consistency of test data is considerably improved by weld bead removal

Cementation scenarios for New Zealand Cenozoic nontropical limestones

Cenozoic limestones are widely distributed in New Zealand, especially in the Oligocene-earliest Miocene in both islands, and the Pliocene-Pleistocene in North Island. A spectrum of limestone types exists, but all are skeletal-dominated (>70%), with usually <20% interparticle cement-matrix and <10% siliciclasts, and they have facies attributes typical of nontropical carbonates. The range of diagenetic features identified within the limestones is the basis for assigning them to a small number of “end-member” cementation classes that are inferred to be associated with four, broad, diagenetic settings

The rats in Hawaiian sugarcane

Heavy losses In Hawaiian sugarcane are caused by Polynesian rats (Rattus exulans), Norway rats (R. norvegicus), and black rats (R. rattus). Relative population levels, movement patterns, damage to sugarcane, and suggested timing of control during five stages of the 2-year crop cycle are described. The progress toward the registering of zinc phosphide for use in crops and the development of other rodenticides are mentioned

The Effect on Rudder Control of Slip Stream Body, and Ground Interference

This investigation was undertaken to determine the relative effects of those factors which may interfere with the rudder control of an airplane, with especial reference to the process of landing. It shows that ground interference is negligible, but that the effects of a large rounded body and of the slip stream may combine to interfere seriously with rudder control at low flying speeds and when taxiing

Geological and geophysical field investigations from a lunar base at Mare Smythii

Mare Smythii, located on the equator and east limb of the Moon, has a great variety of scientific and economic uses as the site for a permanent lunar base. Here a complex could be established that would combine the advantages of a nearside base (for ease of communications with Earth and normal operations) with those of a farside base (for shielding a radio astronomical observatory from the electromagnetic noise of Earth). The Mare Smythii region displays virtually the entire known range of geological processes and materials found on the Moon; from this site, a series of field traverses and investigations could be conducted that would provide data on and answers to fundamental questions in lunar geoscience. This endowment of geological materials also makes the Smythii region attractive for the mining of resources for use both on the Moon and in Earth-Moon space. We suggest that the main base complex be located at 0, 90 deg E, within the mare basalts of the Smythii basin; two additional outposts would be required, one at 0, 81 deg E to maintain constant communications with Earth, and and the other, at 0, 101 deg E on the lunar farside, to serve as a radio astronomical observatory. The bulk of lunar surface activities could be conducted by robotic teleoperations under the direct control of the human inhabitants of the base

Lithostratigraphy and depositional episodes of the Oligocene carbonate-rich Tikorangi Formation, Taranaki Basin, New Zealand

The subsurface Oligocene Tikorangi Formation is a unique and important oil producer in the onshore Waihapa-Ngaere Field, Taranaki Basin, being the only carbonate and fracture-producing reservoir within the basin. Core sample data from seven onshore wells (foredeep megafacies) and a single offshore well (basinal megafacies) are correlated with a suite of sonic and gamma-ray geophysical well log data to derive interpretative carbonate facies for the Tikorangi Formation. Four mixed siliciclastic-carbonate to carbonate facies have been defined: facies A-calcareous siliciclastite (75% carbonate). Single or interbedded combinations of these facies form the basis for identifying nine major lithostratigraphic units in the Tikorangi Formation that are correlatable between the eight wells in this study.The Tikorangi Formation accumulated across a shelf-slope-basin margin within a tectonically diversified basin setting, notably involving considerable off-shelf redeposition of sediment into a bounding foredeep. Analysis of gamma, sonic, and resistivity well logs identifies five major episodes of sedimentary evolution. Episode I comprises retrogradational siliciclastic-dominated redeposited units associated with foredeep subsidence. Episode II is a continuation of episode I retrogradation, but with increased mass-redeposited carbonate influx during accelerated foredeep subsidence and relative sea-level rise, the top marking the maximum flooding surface. Episode III involves a progradational sequence comprising relatively pure redeposited carbonate units associated with declining subsidence rates and minimal siliciclastic input, with movement of facies belts basinward. Episode IV consists of prograding aggradation involving essentially static facies belts dominated by often thick, periodically mass-emplaced, carbonate-rich units separated by thin background siliciclastic shale-like units. Episode V is a retrogradational sequence marking the reintroduction of siliciclastic material into the basin following uplift of Mesozoic basement associated with accelerated compressional tectonics along the Australia-Pacific plate boundary, initially diluting and ultimately extinguishing carbonate production factories and terminating deposition of the Tikorangi Formation

Energy efficient transport technology: Program summary and bibliography

The Energy Efficient Transport (EET) Program began in 1976 as an element of the NASA Aircraft Energy Efficiency (ACEE) Program. The EET Program and the results of various applications of advanced aerodynamics and active controls technology (ACT) as applicable to future subsonic transport aircraft are discussed. Advanced aerodynamics research areas included high aspect ratio supercritical wings, winglets, advanced high lift devices, natural laminar flow airfoils, hybrid laminar flow control, nacelle aerodynamic and inertial loads, propulsion/airframe integration (e.g., long duct nacelles) and wing and empennage surface coatings. In depth analytical/trade studies, numerous wind tunnel tests, and several flight tests were conducted. Improved computational methodology was also developed. The active control functions considered were maneuver load control, gust load alleviation, flutter mode control, angle of attack limiting, and pitch augmented stability. Current and advanced active control laws were synthesized and alternative control system architectures were developed and analyzed. Integrated application and fly by wire implementation of the active control functions were design requirements in one major subprogram. Additional EET research included interdisciplinary technology applications, integrated energy management, handling qualities investigations, reliability calculations, and economic evaluations related to fuel savings and cost of ownership of the selected improvements

Petrogenesis of the Tikorangi Formation fracture reservoir, Waihapa-Ngaere Field, Taranaki Basin

The subsurface mid-Tertiary Tikorangi Formation is the sole limestone and the only fracture-producing hydrocarbon reservoir within Taranaki Basin. This study, based on core material from seven wells in the onshore Waihapa/Ngaere Field, uses a range of petrographic (standard, CL, UV, SEM) and geochemical techniques (stable isotope, trace element data, XRD) to unravel a complex diagenetic history for the Tikorangi Formation. A series of eight major geological-diagenetic events for the host rock and fracture systems have been established, ranging from burial cementation through to hydrocarbon emplacement within mineralized fractures. For each diagenetic event a probable temperature field has been identified which, combined with a geohistory plot, has enabled the timing of events to be determined. This study has shown that the Tikorangi Formation comprises a complex mixed siliciclastic-carbonate-rich sequence of rocks that exhibit generally tight, pressure-dissolved, and well cemented fabrics with negligible porosity and permeability other than in fractures. Burial cementation of the host rocks occurred at temperatures of 27-37°C from about 0.5-1.0 km burial depths. Partial replacement dolomitisation occurred during late burial diagenesis at temperatures of 36-50°C and at burial depths of about 1.0 km, without any secondary porosity development. Fracturing occurred after dolomitisation and was associated with compression and thrusting on the Taranaki Fault. The location of more carbonate/dolomite-rich units may have implications for the location of better-developed fracture network systems and for hydrocarbon prospectivity and production. Hydrocarbon productivity has been ultimately determined by original depositional facies, diagenesis, and deformation. Within the fracture systems, a complex suite of vein calcite, dolomite, quartzine, and celestite minerals has been precipitated prior to hydrocarbon emplacement, which have substantially healed and reduced fracture porosities and permeabilities. The occurrence of multiple vein mineral phases, collectively forming a calcite/dolomite-celestite-quartzine mineral assemblage, points to fluid compositions varying both spatially and temporally. The fluids responsible for vein mineralisation in the Tikorangi Formation probably involved waters of diverse origins and compositions. Vein mineralisation records a history of changing pore fluid chemistry and heating during burial, punctuated by changes in the relative input and mixing of downward circulating meteoric and upwelling basinal fluids. A sequence of mineralisation events and their probable burial depth/temperature fields have been defined, ranging from temperatures of 50-80°C and burial depths of 1.0-2.3 km. Hydrocarbon emplacement has occurred over the last 6 m.y. following the vein mineralization events. The Tikorangi Formation must continue to be viewed as a potential fracture reservoir play within Taranaki Basin

Lithostratigraphy and depositional episodes of the Oligocene carbonate-rich Tikorangi Formation, Taranaki Basin, New Zealand

The subsurface Oligocene Tikorangi Formation is a unique and important oil producer in the onshore Waihapa-Ngaere Field, Taranaki Basin, being the only carbonate and fracture-producing reservoir within the basin. Core sample data from seven onshore wells (foredeep megafacies) and a single offshore well (basinal megafacies) are correlated with a suite of sonic and gamma-ray geophysical well log data to derive interpretative carbonate facies for the Tikorangi Formation. Four mixed siliciclastic-carbonate to carbonate facies have been defined: facies A-calcareous siliciclastite (75% carbonate). Single or interbedded combinations of these facies form the basis for identifying nine major lithostratigraphic units in the Tikorangi Formation that are correlatable between the eight wells in this study.The Tikorangi Formation accumulated across a shelf-slope-basin margin within a tectonically diversified basin setting, notably involving considerable off-shelf redeposition of sediment into a bounding foredeep. Analysis of gamma, sonic, and resistivity well logs identifies five major episodes of sedimentary evolution. Episode I comprises retrogradational siliciclastic-dominated redeposited units associated with foredeep subsidence. Episode II is a continuation of episode I retrogradation, but with increased mass-redeposited carbonate influx during accelerated foredeep subsidence and relative sea-level rise, the top marking the maximum flooding surface. Episode III involves a progradational sequence comprising relatively pure redeposited carbonate units associated with declining subsidence rates and minimal siliciclastic input, with movement of facies belts basinward. Episode IV consists of prograding aggradation involving essentially static facies belts dominated by often thick, periodically mass-emplaced, carbonate-rich units separated by thin background siliciclastic shale-like units. Episode V is a retrogradational sequence marking the reintroduction of siliciclastic material into the basin following uplift of Mesozoic basement associated with accelerated compressional tectonics along the Australia-Pacific plate boundary, initially diluting and ultimately extinguishing carbonate production factories and terminating deposition of the Tikorangi Formation

MHD Mode Conversion around a 2D Magnetic Null Point

Mode conversion occurs when a wave passes through a region where the sound and Alfven speeds are equal. At this point there is a resonance, which allows some of the incident wave to be converted into a different mode. We study this phenomenon in the vicinity of a two-dimensional, coronal null point. As a wave approaches the null it passes from low- to high-beta plasma, allowing conversion to take place. We simulate this numerically by sending in a slow magnetoacoustic wave from the upper boundary; as this passes through the conversion layer a fast wave can clearly be seen propagating ahead. Numerical simulations combined with an analytical WKB investigation allow us to determine and track both the incident and converted waves throughout the domain.Comment: 4 pages, 2 figure