6,093 research outputs found
Mark Clay Davis, February 26, 1933 - July 7, 2023
No full textMark Clay Davis passed away peacefully on July 7, 2023 at the age of 90. A graduate of Stanford University, Mark was the founder of the Stanford Real Estate Club. He remained an active Stanford University alumnus for the rest of his life
Recommended from our members
[Letter from Clay Hooper to Jack Davis, November 29, 1990]
No full textPhotocopy of a letter from Clay Hooper, Regional Manage, Public Affairs of Chevron, to Jack Davis, co-director of North Texas Institute for Educators on the Visual Arts. In regards to Davis's proposal requesting a grant of $10,000 from Chevron to match their grant for their discipline-based art education reform program. Hooper writes that their program is not one they are supporting at the current time
Receipt for payment from Mrs. Hugh Davis to Harral and Clay, Selma, Alabama, April 16, 1877
No full textThis item is from the Hugh Davis papers. He was a successful attorney from Marion, Alabama who owned the Beaver Bend plantation along the Cahaba River
Polymer-clay Nanocomposites
No full textPhDPolymer-clay nanocomposites are attracting global interest principally because
property enhancements are obtained at low clay particle loadings (1-5 wt%).
However there is lack of fundamental understanding of such composites. The aim
of this work is to provide an insight into the interaction between polymer and clay.
This includes the driving force for intercalation, the reinforcement mechanisms and
property-volume fraction relationships.
Functionalised poly(ethylene glycol)-clay, poly(c-caprolactone)-clay and
thermoplastic starch-clay nanocomposites with a range of polymer molecular
weights, clay volume fractions and with different clays were prepared using
solution methods, melt-processing methods, and in situ polymerisation. A reliable
X-ray diffraction technique for low angle basal plane spacing of clay, the essential
parameter for structure determination, was established obtaining ±0.005 Mn
between three diffractometers. The basal plane spacing was found to be unaffected
by polymer molecular weight and preparation method but was affected by the
nature of the polymer and clay. Increasing clay loading could lead to a lower
spacing. As a cautionary observation, poly(ethylene glycol) with high molecular
weight (2: 10,000) was found to undergo degradation readily during preparation of
nanocomposites with and without clay.
Competitive sorption experiments for molecular weight showed that high
molecular weight fractions of polymer intercalate preferentially into clay during
solution preparation. Thermodynamic studies on the intercalation process found
that significant enthalpic change occurred during intercalation, which is coincident
with the observation that heat-treated clays without interlayer water can intercalate
polymer. The calculation of true volume fraction against nominal volume fraction
provided reasonable explanation of property enhancement and helps understand the
relation between nanocomposites and conventional composites. At a given clay
loading, nanocomposites with better dispersion gave more property enhancement
than those with lower dispersion or conventional composites. The crystallinity of
semicrystalline polymer was also affected by varying extents of dispersion of clay.
The use of X-ray diffraction with an internal standard was explored for quantitative
analysis of intercalation and exfoliation
Recommended from our members
[Letter from Jack Davis to Clay Hooper, October 5, 1990]
No full textPhotocopy of a letter from Jack Davis, co-director of North Texas Institute for Educators on the Visual Arts, to Clay Hooper, Regional Manager, Public Affairs of Chevron. The letter is in regards to a proposal Davis is making to Hooper, hoping that Chevron will give a grant worth 600,000 grant from the Getty Center for Education in the Arts and they are required to raise $400,000 in matching grant through outside support. Enclosed with the letter is an abstract about what NTIEVA hopes to achieve
Mineral acquisition from clay by Budongo Forest chimpanzees
No full textDate of Acceptance: 06/07/2015Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to the mineral intake of the Sonso chimpanzees and show that clay eaten using leaf sponges is particularly rich in minerals. We show that termite mound soil, also regularly consumed, is rich in minerals. We discuss the frequency of clay and termite soil geophagy in the context of the disappearance from Budongo Forest of a formerly rich source of minerals, the decaying pith of Raphia farinifera palms.Peer reviewe
Guide to the nature and methods of analysis of the clay fraction of tephras from the South Auckland region, New Zealand.
No full textThe manual outlines some of the more common laboratory procedures available for qualitatively and quantitatively analysing the composition of the tephric clays, many of which are difficult to determine because of their short range order or 'amorphous' nature. Techniques described and assessed in terms of their rapidity and quantitativeness include XRD, IR, DTA, TEM and SEM, sodium fluoride reactivity, chemical dissolution analyses, and surface area measurements. No one technique alone produces a definitive clay fraction analysis of tephric deposits. -from Author
Death and design: the terror management function of teleological beliefs
No full textHumans have a tendency to endorse teleological beliefs about the world. According to terror management theory, teleological or purposeful beliefs about the world help people cope with the awareness of mortality. Though research is generally consistent with this assertion, it has not been directly tested. Three studies tested and supported the notion that teleological beliefs about the world serve a terror management function. In “Study 1”, experimentally elevated teleological beliefs reduced death-thought accessibility. In “Studies 2 and 3”, mortality salience increased teleological beliefs, even if this resulted in judgment errors. Alternative explanations were tested and did not account for the findings
Capital accumulation, unemployment, and the putty-clay
No full textThis note studies the dynamics of labor markets in a putty-clay framework. It analyzes the evolution of job creation and job destruction in an economy without market frictions. Unemployment and labor market flows emerge under putty-clay technologies because low productive jobs become unused factors. As capital accumulates, firms destruct low productive jobs by obsolescence. Simultaneously, the use of capital intensive technologies s new jobs by the low substitution between capital and labor.
Collective effects on the settling of clay flocs
No full textIn this work a high-magnification digital video camera in combination with a settling column is used to study in a first part the influence of the amount of flocs transferred into the settling column on their settling velocity. In a second part, the setup was used to study the properties of flocs prepared at different clay concentrations but at same flocculant to clay ratio (2.5mgg−1). Illite clay was used and flocculated in a 1 L jar with an anionic polyacrylamide (flocculant). Results show that the average settling velocity of flocs is a function of the amount of transferred flocs. It was also found that floc size and settling velocity depend on clay concentration. This is attributed to the fast aggregation happening in the jar when flocculant and clay are mixed: at higher clay concentrations, larger flocs are created in the first minutes of the experiment, with low densities that prevent them from settling to the bottom of the jar.Environmental Fluid MechanicsRivers, Ports, Waterways and Dredging Engineerin
- …
