Visual determination of industrial color-difference tolerances using probit analysis

A perceptibility study was conducted to visually determine the median tolerance values of 45 color-difference vectors in CIELAB color space using surface mode viewing of paint samples. Nine different color centers, each compris ing five color vectors, were employed to collect a superthreshold dataset. Fifty color-normal observers made quantal judgements under simulated Dg^ illuminant regarding the magnitude of color-difference pairs based on comparisons to a near-neutral color-difference anchor pair. Probit analysis was applied to the response frequencies for each vector to estimate the parameters of the distribution and the median tolerance values. Results indicated the probit adequately models the response distributions of the human observer population

APPLICATIONS OF CALCULATED SECOND HARMONIC GENERATION TENSORS ON MONOMOLECULAR AND BIMOLECULAR SYSTEMS

The field of nonlinear optics (NLO) has proven itself as a relatively recent and powerful area of science in the areas of microscopy and high-sensitivity quantification measurements. In particular, symmetry selective NLO processes such as second harmonic generation (SHG) take advantage of symmetry rules to cancel background noise almost completely, leading to both high resolution images and limits of detection (LOD) in the photon counting range. Background noise in SHG is negated as result of signal cancellation in systems containing inversion symmetry; generally isotropic sources. Quantum mechanical computational chemistry has enriched the field of NLO by enabling studies on hypothetical systems and environments that are otherwise unobtainable in experiments. Such systems are of benefit to study on account of their simplicity and the removal of common sources of experimental interference. In the presented work, three particular examples are presented. In the first example, simulated SHG response is investigated for noncentrosymmetric dimers constructed from nominally centrosymmetric monomers whilst a theoretical explanation is developed for the origin of said response. In the second example, calculated SHG tensor elements are used in a sum-over-orientations algorithm to approximate experimentally bright SHG responses on various crystallized active pharmaceutical ingredients (APIs). By comparison with experiments, the predictive capability of time-dependent Hartree Fock (TDHF) is assessed with promising results. In the third example, SHG tensor elements calculated using TDHF simulations are utilized to predict polarization dependent two-photon absorption (PDTPA) for monomolecular systems. This is done by relating each SHG element to the product of the two-photon absorption element with the polarization dependent transition dipole

Melting of cognetic depleted and enriched reservoirs and the production of high Ti Mare basalts

Implicit in current understanding of the location of terrestrial enriched and depleted reservoirs is the notion that they are spatially separated. The depleted reservoir on Earth is situated in the upper mantle, and the complementary enriched reservoir is located in the crust. However, Earth reservoirs are continually being modified by recycling driven by mantle convection. The Moon is demonstrably different from Earth in that its evolution was arrested relatively early - effectively with 1.5 Ga of its formation. It is possible that crystallized trapped liquids (from the late stages of a magma ocean) have been preserved as LILE-enriched portions of the lunar mantle. This would lead to depleted (cumulate) and enriched (magma ocean residual liquid) reservoirs in the lunar upper mantle. There is no evidence for significant recycling from the highland crust back into the mantle. Therefore, reservoirs created at the Moon's inception may have remained intact for over 4.0 Ga. The topics discussed include the following: (1) radiogenic isotopes in high-Ti mare basalts; (2) formation of cogenetic depleted and enriched reservoirs; and (3) melting of the source to achieve high-Ti mare basalts

neoKREEP: A new lunar component at Apollo 17

The Apollo 11 (Mare Tranquillitatis) and Apollo 17 (Mare Serenitatis) landing sites are important as the only sources of high-Ti basalt visited by the Apollo missions. The lunar high-Ti basalts (greater than 6 percent TiO2) have no volumetrically comparable analogs among terrestrial basalts and require the presence of ilmenite in the source region, probably representing cumulates produced late in the crystallization of the lunar magma ocean. Six principal groups of high-Ti basalts are described, three from each of the two sites

Predicted Electronic and Thermodynamic Properties of a Newly Discovered Zn_8Sb_7 Phase

A new binary compound, Zn_8Sb_7, has recently been prepared in nanoparticulate form via solution synthesis. No such phase is known in the bulk phase diagram; instead, one would expect phase separation to the good thermoelectric semiconductors ZnSb and Zn_4Sb_3. Here, density functional calculations are employed to determine the free energies of formation, including effects from vibrations and configurational disorder, of the relevant phases, yielding insight into the phase stability of Zn_8Sb_7. Band structure calculations predict Zn_8Sb_7, much like ZnSb and Zn_4Sb_3, to be an intermetallic semiconductor with similar thermoelectric properties. If sufficient entropy or surface energy exists to stabilize the bulk material, it would be stable in a limited temperature window at high temperature

Entropic Stabilization and Retrograde Solubility in Zn4Sb3

Zn4Sb3 is shown to be entropically stabilized versus decomposition to Zn and ZnSb though the effects of configurational disorder and phonon free energy. Single phase stability is predicted for a range of compositions and temperatures. Retrograde solubility of Zn is predicted on the two-phase boundary region between Zn4Sb3 and Zn. The complex temperature dependent solubility can be used to explain the variety of nanoparticle formation observed in the system: formation of ZnSb on the Sb rich side, Zn on the far Zn rich side and nano-void formation due to Zn precipitates being reabsorbed at lower temperatures.Comment: 5 pages, 5 figure

Promoting Religious Freedom: A Corporate Social Responsibility

New research highlights a significant upside to businesses from a focus on religious freedom. Making religious freedom a part of corporate social responsibility ("CSR") can produce direct, positive benefits to company operations, improve economic markets, and lead to lasting changes in communities where the human right of religious freedom traditionally lacks roots