Highlights A model was developed to express soil-metal sliding resistance in terms of normal stress and sliding path length. Soil-metal sliding resistance data, different from those used to develop the model, were acceptably simulated. The model is expected to be useful in the design and development of soil-engaging equipment. Abstract . Most previous soil-material sliding resistance studies have focused on the measurement and formulation of only qualitative relationships between sliding resistance and the material type, applied normal stress, sliding path length, and/or soil-properties. Few studies have attempted to formulate quantitative mathematical relationships between soil-material sliding resistance and these factors, or to mathematically express the relative contributions of the frictional and adhesive components to the total sliding resistance. In this study, a mathematical model was developed to express the components of soil-metal sliding resistance for a clay soil as functions of applied normal stress and sliding path length. The model is restricted to soil containing enough moisture to exhibit cohesive strength, but not so much moisture to exhibit gross plastic behavior. Soil-metal sliding resistance data, different from those used to develop the model, were acceptably simulated, as the mean square error between the simulated sliding resistance and the measured sliding resistance ranged from 0.653 to 2.44. Keywords: Adhesion, Friction, Normal stress, Sliding path length, Sliding resistance.

Abstract. A shearing strain model for soil was developed that includes soil behavior under compressive normal and shear stresses great enough to attain maximum compaction. The model was developed for a clay and a clay loam from triaxial data with various stress loading paths. This model relates the ratio of maximum shear stress acting on the cylindrical sample (tmax) to major principal stress (s1), to the ratio of maximum natural shearing strain to natural volumetric strain occurring after shear stress is initiated. The model accurately describes the shearing distortion of triaxial soil samples under cylindrical stress loading prior to yielding by plastic flow. This model predicts soil shearing strain for input stress states that realistically represent field conditions. Keywords: Principal stress and strain, Shearing strain, Shear stress, Soil compaction, Soil parameters, Triaxial tests.

Axisymmetric finite element (FE) method was developed to simulate cone penetration process in layered granular soil. The FE was modeled using ABAQUS/Explicit, a commercially available package. Soil was considered as a non-linear elastic plastic material which was modeled using variable elastic parameters of Young’s Modulus and Poisson’s ratio and Drucker–Prager criterion with yield stress dependent material hardening property. The material hardening parameters of the model were estimated from the USDA-ARS National Soil Dynamics Laboratory – Auburn University (NSDL-AU) soil compaction model. The stress–strain relationship in the NSDLAU compaction model was modified to account for the different soil moisture conditions and the influence of precompression stress states of the soil layers. A surface contact pair (‘slave-master’) algorithm in ABAQUS/Explicit was used to simulate the insertion of a rigid cone (RAX2 ABAQUS element) into deformable and layered soil medium (CAX4R ABAQUS element). The FE formulation was verified using cone penetration data collected on a soil chamber of Norfolk sandy loam soil which was prepared in two compaction treatments that varied in bulk density in the hardpan layer of (1) 1.64Mgm−3 and (2) 1.71Mgm−3. The FE model successfully simulated the trend of cone penetration in layered soils indicating the location of the sub-soil compacted (hardpan) layer and peak cone penetration resistance. Modification of the NSDL-AU model to account for the actual soil moisture content and inclusion of the influence of precompression stress into the strain behavior of the NSDL-AU model improved the performance of FE in predicting the peak cone penetration resistance. Modification of the NSDL-AU model resulted in an improvement of about 42% in the finite element-predicted soil cone penetration forces compared with the FE results that used the NSDL-AU ‘virgin’ model.

A finite element modelling technique is being developed as a management tool that can be used to predict and avoid excessive soil compaction. Values of normal stress between a rigid wheel and the soil were obtained using an instrumented bar across the width of the wheel. These values were used to apply loads to the finite element model. A non-linear stress-strain relationship was used that shows that soil compaction is a function of both normal and shearing stress. The linear-elastic parameters, Young's Modulus and Poisson's ratio, are updated at small increments of load to follow the non-linear stress-strain relationship closely. Values of octahedraI normal (mean normal) and major principal stress are predicted accurately in some situations but not at the high load condition in an initially uniformly loose soil profile.

Soil stress states were measured beneath the path of a rigid wheel (137 cm diameter). A multivariate analysis of variance was conducted on the data to determine the effect on stress state caused by dynamic and tractive wheel loads, in different soil types and with or without the presence of a hardpan. Results should aid in decisions concerning soil compaction due to wheel loads.

ABSTRACTCampos de murundus (earthmound fields) are common throughout the cerrado (savanna) in Brazil. They have a clearly defined distribution particularly where they are associated with ground water. There is a distinctive woody vegetation on the discrete mounds contrasting with surrounding grass-covered depressions.After a reconnaissance ground and air-photograph survey of the nature and distribution of mounds within the Federal District, four one-hectare plots were chosen for detailed study within the ecological reserve of the University of Brasília. Measurements were made of the size, shape and frequency of mounds. Numbers varied from 26 to 61 ha-1 with a uniform distribution occupying 10–50% of the plots. Heights ranged from 0.05 to over 2 m. The generally semi-elliptical shape in ground plan had an average size of 7 by 5.5 m with no evidence of preferred orientation although water scouring from runoff partly influences the morphology. Volumes varied from 0.01 m3 to 141.5 m3. The soils of the murundus differed from those of surrounding depressions by being better drained, with bright colours and strong cohesive structures; they were more argillic with lower base saturation and pH values. Such sites favour colonization both by cerrado plants and by termites. A classification of the murundus is postulated. Although this paper does not consider the origins of murundus, they appear to relate more closely to drainage and differential erosion than to termite activity.

The optical-microwave atomic-beam magnetic resonance technique has been used to measure four hyperfine transitions in the ${2}^{3}$P state $^{3}\mathrm{He}$. These were used to determine the three hyperfine interaction constants (in MHz) as follows: contact, C=-4283.${84}_{\mathrm{\ensuremath{-}}0.01}^{+0.02}$; nuclear-moment-electron-orbit, D=-28.06\ifmmode\pm\else\textpm\fi{}0.06; nuclear-moment-electron-momment, E=+7.10\ifmmode\pm\else\textpm\fi{}0.02. THe results, which are in excellent agreement with theory, give a clear indication of the effects of core polarization on the hyperfine structure. We conclude that to the accuracy indicated the structure of the 2 $^{3}$P state, including mass-dependet and quantum electrodynamic corrections to the fine structure, and relativistic and core-polarization corrections to the hyperfine structure, is well understood.

Magnetic susceptibilities, e.s.r. spectra, and Mössbauer spectra have been measured for Fe[N(SiMe3)2]3 over a temperature range, and the data, together with electronic absorption spectra, interpreted in terms of crystal-field calculations for a high-spin d5 system in D3h symmetry.

An extensive study of the isomer shift and hyperfine field distribution in the Mossbauer spectra of dilute 57Fe in copper-nickel alloys has shown the existence of metallurgical clustering, both Fe-Fe and Fe-Ni which is partially destroyed by cold working. The doublets observed in the 300 K spectra are produced by electrostatic effects associated with the existence of virtual bound states on both iron and nickel atoms

Journal Article GUSTATORY HYPERRTBROSIS. A Complication of Thyroidectomy. Get access W. J. Cunliffe, B.Sc, M.B., M.R.C.P., W. J. Cunliffe, B.Sc, M.B., M.R.C.P. University Department of Dermatology, Royal Victoria Infirmary, Newcastle Upon Tyne Search for other works by this author on: Oxford Academic Google Scholar C. E. JOHNSON, B.Sc. C. E. JOHNSON, B.Sc. University Department of Dermatology, Royal Victoria Infirmary, Newcastle Upon Tyne Search for other works by this author on: Oxford Academic Google Scholar British Journal of Dermatology, Volume 79, Issue 10, 1 October 1967, Pages 519–526, https://doi.org/10.1111/j.1365-2133.1967.tb11406.x Published: 01 October 1967

The SNAP 8 reactor is a heat source suitable for long endurance 10 to 50 kw space electric power supplies. The major milestones in the development of this reactor are three ground tests: the SNAP 8 Experimental Reactor (S8ER), the SNAP 8 Developmental Reactor Mockup (S8DRM), and the SNAP 8 Developmental System (S8DS). The S8ER test was completed in April 1965 after 500 days of nuclear operation. S8ER demonstrated long-term operation of the SNAP 8 reactor by operating for 1 year at thermal power levels in the range 400 to 600 kwt with a 1300° F coolant NaK outlet temperature. This test included a continuous run of 5000 hours. The continuous operation of S8ER was due in part to a facility reliability upgrading undertaken to minimize unnecessary test interruptions caused by instrumentation malfunctions or electrical disturbances at the test site. The second SNAP 8 reactor, S8DRM, has undergone a series of nonnuclear tests to verify the performance of the automatic startup and control drive system, and to determine the reactor's environmental capabilities (e.g., shock, vibration, vacuum, and temperature). The third SNAP 8 reactor test, S8DS, will start nuclear operation late in 1966. The objective of this test is to verify the SNAP 8 flight reactor design, and to operate the reactor coupled to a power conversion system.

THE UNIVERSAL USE of polyethylene catheters for prolonged intravenous fluid therapy prompts me to report this unusual and fatal complication. In 1954, Turner and Sommers1reported the first case of a polyethylene catheter which had become lodged in the right atrium after it had escaped into the venous system during intravenous infusions. In their case massive thrombus formation around the catheter contributed to the patient's death. Several reports2,3since concern themselves with the successful removal of such catheters from the right side of the heart. In 1956, Brown and Kent4reported the first case of fatal perforation of the heart by one of these catheters. Presented below is, to my knowledge, the second fatal case of perforation of the heart by a severed piece of polyethylene tubing which escaped into the vascular system during prolonged intravenous fluid therapy. Report of a Case The patient, a 50-year-old white