Single ball bearing lubricant and material evaluator

A test apparatus provides an applied load to a monoball through a trolley which moves along a loading axis. While applying the load to the monoball, the torque meter is in communication with the spherical monoball, and a load cell senses the application of applied force to the monoball. Meanwhile, a rotary actuary imports rotary oscillating motion to the monoball which is sensed by a position sensor and a torque meter. Accordingly, a processor can determine the coefficient of friction in substantially real time along with a cycles per second rate

Impurity Diffusion as a Possible Metal Chronometer for Pre-Detonation Nuclear Forensics

The ability to determine the age of seized nuclear material—that is, the time that has passed since it was formed— would provide crucial data to be used in its investigation. This paper reviews the methods and mathematical reasoning behind the use of diffusion theory, as previously applied to analysis of metals in ancient artifacts and other objects, to modern investigations in nuclear science. We here examine the time-dependent processes of diffusion, including grain boundary diffusion and discontinuous precipitation, and we assess the utility of examining the profiles of impurity and alloying element concentrations for use as a tool in pre-detonation nuclear forensics

Addressing Imbalances in US Nuclear Economic and Nonproliferation Policies

Foreign civilian nuclear start-ups have an increasing number of international partners capable of supplying fuel cycle technologies. The desire to prevent the spread of dual-use enrichment and reprocessing technology by asking partner states to rely on international fuel markets is a major obstacle for US negotiating civilian nuclear trade agreements, leading to delays. US participation in emerging nuclear markets is being undercut by foreign competition, leading to decreasing economic competition and influence in international nonproliferation issues. It is therefore necessary for the US to reinvest and complete its domestic nuclear fuel cycle and modify its process for implementing civilian nuclear cooperation agreements with other states. By reducing delays in negotiations, having a larger stake in the uranium fuel supply provided to international markets, and outlining a clear waste policy, Washington will advance both its economic and nonproliferation goals

Improved Apparatus for Testing Monoball Bearings

A desk-sized apparatus for testing monoball bearings and their lubricants offers advantages, relative to prior such apparatuses, of (1) a greater degree of automation and (2) capability of operation under wider and more realistic ranges of test conditions. The ranges of attainable test conditions include load from 100 to greater h than 50,000 lb (445 to greater than 2.22 x 10(exp 5) N), resisting torque up to 30,000 lb-in. (approximately equal to 3,390 N-m), oscillating rotation through an angle as large as 280 degrees, and oscillation frequency from 0 to 6 Hz. With addition of some components and without major modification of the apparatus, it is also possible to perform tests under environmental conditions that include temperature from -320 to 1,000 F (-196 to +538 C), relative humidity from 0 to 100 percent, and either air at ambient pressure, high vacuum, or an atmosphere of monatomic oxygen. In the apparatus (see Figure 1), a monoball bearing specimen is driven in oscillating rotation by a hydraulic rotary actuator through a series of shafts, one of which incorporates a torque meter and one of which is a flexible coupling. The torque meter measures the resisting torque; the flexible coupling accommodates misalignment, wear, and compression of the specimen and ensures equal loading on opposite sides of the monoball. Not shown in the figure is an angular-position sensor that is used for measuring the angle of rotation of the shafts

Corrosion Inhibitors as Penetrant Dyes for Radiography

Liquid/vapor-phase corrosion inhibitors (LVCIs) have been found to be additionally useful as penetrant dyes for neutron radiography (and perhaps also x-radiography). Enhancement of radiographic contrasts by use of LVCIs can reveal cracks, corrosion, and other defects that may be undetectable by ultrasonic inspection, that are hidden from direct optical inspection, and/or that are difficult or impossible to detect in radiographs made without dyes

Computer Simulation of Flows in a Channel with Extremely Irregular Bed Topography

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Ukraine At The Fulcrum: A Nuclear House Of Cards

The foundation of preserving and enhancing global nuclear security rests on three fundamental pillars: nuclear disarmament; preventing further proliferation of nuclear weapons; and international cooperation aimed at safeguarding nuclear materials. Today, experts argue that the recent decision of Russian president Vladimir Putin to cut cooperative efforts to secure nuclear materials are placing in peril the future of international efforts to promote global nuclear security. We argue that in addition to the clear erosion of the third pillar of nuclear security, there are more threatening ramifications resulting from the recent actions of Russia in Ukraine. The aggressive actions of Russia in Ukraine, together with the unwillingness of the international community to exert sufficient pressure on Russia to honor the promises made to Ukraine in exchange for giving up nuclear weapons in 1990s (the Budapest Memorandum) are detrimental to non-proliferation objectives and reach far beyond the geographic boundaries of the current conflict. In addition, they may disrupt both further nuclear disarmament and stimulate proliferation of nuclear weapons. To the government of any country who has resisted the push toward nuclearization based on trust placed in international agreements, the inactions and/or inability of the international community to resist or reverse Russia’s illegal actions must cause great concern. If binding diplomatic agreements are seen to only bind one party – the weaker party – that party will understandably be very hesitant to place full faith in any diplomatic document short of a binding treaty that has clear and required enforcement mechanisms. This is especially true when the stakes are a country’s national security and ultimately its sovereignty. If any one of these nations moved toward nuclear status, the atomic dominos would surely begin to tumble, and the delicate nuclear equilibrium that defines the global nuclear security landscape today would be lost

Heisenberg-style bounds for arbitrary estimates of shift parameters including prior information

A rigorous lower bound is obtained for the average resolution of any estimate of a shift parameter, such as an optical phase shift or a spatial translation. The bound has the asymptotic form k_I/ where G is the generator of the shift (with an arbitrary discrete or continuous spectrum), and hence establishes a universally applicable bound of the same form as the usual Heisenberg limit. The scaling constant k_I depends on prior information about the shift parameter. For example, in phase sensing regimes, where the phase shift is confined to some small interval of length L, the relative resolution \delta\hat{\Phi}/L has the strict lower bound (2\pi e^3)^{-1/2}/, where m is the number of probes, each with generator G_1, and entangling joint measurements are permitted. Generalisations using other resource measures and including noise are briefly discussed. The results rely on the derivation of general entropic uncertainty relations for continuous observables, which are of interest in their own right.Comment: v2:new bound added for 'ignorance respecting estimates', some clarification

Asymmetric transfer hydrogenation of unsaturated ketones ; factors influencing 1,4- vs 1,2- regio- and enantioselectivity, and alkene vs alkyne directing effects

A detailed study has been completed on the asymmetric transfer hydrogenation (ATH) of a series of enones using Ru(II) catalysts. Electron-rich rings adjacent to the C=O group reduce the level of C=O reduction compared to C=C. The ATH reaction can readily discriminate between double and triple bonds adjacent to ketones, reducing the double bond but leaving a triple bond intact in the major product