Thixotropy of a Transparent Clay Manufactured Using Carbopol to Simulate Marine Soil

A transparent clay manufactured using Carbopol® UltrezTM 10 (simplified as U10) was introduced, and its manufacturing processes were briefly described. Both relative transparency (RT) and modulation transfer function (MTF) methods were used to quantify the optical character variation via soil thickness. The transparency of this new transparent clay was analyzed and compared with four traditional transparent materials. The thixotropic properties of this synthetic transparent clay were measured in detail through the laboratory vane test. An exponential function was used to describe the thixotropy and sensitivity of the clay. The results showed that the new transparent clay has a relatively higher optical transparency than the majority of previous materials. Good-fitting results showed a similar development trend in thixotropy for the synthetic transparent clay and the natural ones. Furthermore, the sensitivity of the transparent clay was low to medium, which can simulate marine soil. With higher optical transparency than and similar thixotropy and sensitivity as natural clays, Carbopol® UltrezTM 10 shows great potential as a substitute for natural clay and is expected to be widely used in model tests.

Thixotropy of A Transparent Clay Manufactured by Carbopol Simulate Marine Soil

A transparent clay manufactured by Carbopol® UltrezTM 10 (simplified as U10) was introduced, and its manufacture processes were briefly described. Both relative transparency (RT) and modulation transfer function (MTF) methods were used to quantify the optical character variation via soil thickness. The transparency of this new transparent clay was comparative analyzed with traditional four previous transparent materials. The results show that this new transparent clay has relative higher optical transparency than majority of previous materials. The thixotropic properties of this synthetic transparent clay were measured in detail through laboratory vane test. Exponential function was used to describe the thixotropy and sensitivity of clay. The good fitting results shown similar development trend of thixotropy for synthetic transparent clay and natural one. Furthermore, sensitivity of transparent clay belongs to low to medium sensitivity, which can simulate marine soil. With the test results, Carbopol® UltrezTM 10 shows a great potential as a substitute for natural clay and is expected to be widely used in model tests.

The influence of first language polysemy and first language and second language lexical frequencies on second language learners’ use of false cognates

Aims and objectives: This study examines second language (L2) bilinguals’ use of words that have the same or similar forms in their two languages but whose meaning extensions differ – that is, false cognates. We examine the conditions under which L2 speakers inappropriately use false cognates in the L2. How do frequency of the relevant words in each language and polysemy of the word in the first language (L1) affect L2 learners’ use of such words? Design: Fifty Spanish L1–English L2 adults translated 80 words in context from Spanish (S) to English (E). The words involved polysemous Spanish words that had several translations in English, one of which was a cognate form. Words were strictly balanced for L1 polysemy (high versus low), frequency of the S word, frequency of the E cognate form, and frequency of the E non-cognate translation. The words were presented in unambiguous contextual frames that pushed for the non-cognate translation in English. Data and analysis: Analyses of variance were used to analyze participants’ translations relative to the variables of Spanish polysemy and the frequencies of the forms in question. Findings: The findings show that the relative transparency or opacity of the mapping between the L1 and L2 influences word choice: the use of a false cognate instead of a competing correct lexical item depends on the complex interaction of L1 polysemy and the lexical frequencies of the L1 and L2 forms in the bilingual’s two languages. Originality: This study strictly controls for several factors crucial to L2 users’ choice of a word in the L2: polysemy in the L1, frequency of the L1 word, and frequencies of the L2 words involved. Significance: When these variables are viewed together, the data reveal a complex interaction showing factors that contribute to the transparency or opacity of the L1–L2 lexical semantic linkages.

Is There a Hollow Inside the Proton?

We discuss a recently proposed interpretation of some model descriptions of the proton-proton elastic scattering data as a manifestation of alleged relative transparency of the central part of the interaction region in the impact parameter space. We argue that the presence of nonzero real part of the elastic scattering amplitude in the unitarity condition enables to conserve the traditional interpretation.

Relative transparency of sea water in the Green-fjord Bay (Spitsbergen)

The results of the analysis of spatial-time variability of relative transparency (depth of disappearance of a standard white Sechi disk) in the Green-fjord Bay (Spitsbergen archipelago) are presented. The data covers the period from 1986 to 1990 and were obtained during carrying- out of the oceanographic monitoring by experts of Barentsburg research station (Murmansk HydroMeteorogical Management) in frame of the program of standard coastal supervision. Some conclusions about the reasons of spatial and time variability of relative transparency depending from change of external conditions are presented.

Polymorphism and electronic structure of polyimine and its potential significance for prebiotic chemistry on Titan

The chemistry of hydrogen cyanide (HCN) is believed to be central to the origin of life question. Contradictions between Cassini–Huygens mission measurements of the atmosphere and the surface of Saturn’s moon Titan suggest that HCN-based polymers may have formed on the surface from products of atmospheric chemistry. This makes Titan a valuable “natural laboratory” for exploring potential nonterrestrial forms of prebiotic chemistry. We have used theoretical calculations to investigate the chain conformations of polyimine (pI), a polymer identified as one major component of polymerized HCN in laboratory experiments. Thanks to its flexible backbone, the polymer can exist in several different polymorphs, which are relatively close in energy. The electronic and structural variability among them is extraordinary. The band gap changes over a 3-eV range when moving from a planar sheet-like structure to increasingly coiled conformations. The primary photon absorption is predicted to occur in a window of relative transparency in Titan’s atmosphere, indicating that pI could be photochemically active and drive chemistry on the surface. The thermodynamics for adding and removing HCN from pI under Titan conditions suggests that such dynamics is plausible, provided that catalysis or photochemistry is available to sufficiently lower reaction barriers. We speculate that the directionality of pI’s intermolecular and intramolecular =N–H…N hydrogen bonds may drive the formation of partially ordered structures, some of which may synergize with photon absorption and act catalytically. Future detailed studies on proposed mechanisms and the solubility and density of the polymers will aid in the design of future missions to Titan.

Transparency Differences at the Top of the Organization

This chapter examines the opposing forces that induce or impede firms to become transparent in terms of their board of directors’ (BoD) and top management teams’ (TMT) demographic characteristics, education, and experiences. Extant literature on governance transparency often draws on a “market-pull perspective” to emphasize the market-level motives that drive organizations toward rising levels of governance transparency. In this chapter we introduce the “strategic hoarding perspective,” which emphasizes the human capital attrition factors that discourage firms to openly report information about their BoD and TMT composition. Our theory and data from 208 large listed firms in Switzerland, the United Kingdom, and the Netherlands for the years 2005 and 2009 suggest that organizations’ relative transparency preferences in terms of BoD and TMT characteristics can better be explained based on a combination of market-pull and strategic hoarding perspectives. Implications and directions for further research are discussed.