Artificial illumination is a fundamental human need. Burning wood and other materials usually in hearths and fireplaces extended daylight hours, whilst the use of flammable substances in torches offered light on the move. It is increasingly understood that pottery played a role in light production. In this study, we focus on ceramic oval bowls, made and used primarily by hunter-gatherer-fishers of the circum-Baltic over a c. 2000 year period beginning in the mid-6th millennium cal bc. Oval bowls commonly occur alongside larger (cooking) vessels. Their function as ‘oil lamps’ for illumination has been proposed on many occasions but only limited direct evidence has been secured to test this functional association. This study presents the results of molecular and isotopic analysis of preserved organic residues obtained from 115 oval bowls from 25 archaeological sites representing a wide range of environmental settings. Our findings confirm that the oval bowls of the circum-Baltic were used primarily for burning fats and oils, predominantly for the purposes of illumination. The fats derive from the tissues of marine, freshwater, and terrestrial organisms. Bulk isotope data of charred surface deposits show a consistently different pattern of use when oval bowls are compared to other pottery vessels within the same assemblage. It is suggested that hunter-gatherer-fishers around the 55th parallel commonly deployed material culture for artificial light production but the evidence is restricted to times and places where more durable technologies were employed, including the circum-Baltic.

Recent scholarship suggests that Bonaventure breaks with the Augustinian tradition, in part, by affirming that the mind's cognitive powers remain fully activated even after the fall. I suggest that this claim concerning Bonaventure's denial of the noetic effects of sin should be reconsidered. I provide evidence to show that Bonaventure did, indeed, affirm that the intellect was heavily damaged by the fall and that Bonaventure affirmed two at first seemingly paradoxical propositions: (1) the intellect is indeed damaged by the fall, and (2) that God remains the first thing known by the intellect. It is precisely Bonaventure's coupling of these two seemingly paradoxical propositions that have led some to underplay Bonaventure's affirmation of the noetic effects of sin. In other words, Bonaventure's model opens up the possibility of affirming that the results of the noetic effects of sin consists not in ignorance of God simpliciter, but in a paradoxical state of knowing-yet-not-knowing God, akin to Paul's account of Romans 1.

The CytoViva Enhanced Darkfield (EDF) Illuminator enables direct optical observation of nano-scale entities in a wide range of transparent and translucent sample environments, without requiring the use of labels or other markers. The improved performance is a result of a uniquely designed light path, which focuses maximum photon density on the sample, thus enabling superior signal-to-noise imaging performance. This high-performance capability not only provides users with previously unobtainable images, but it also allows established techniques such as hyperspectral and Raman microscopy to be used in new and exciting ways.

There is considerable debate as to the optimal light intensities for growing chickens. This is influencing regulations and industry practices. The present study examines the preference of broiler chickens for light intensity. A choice system was developed to allow determination of the preferences of broiler chickens for light intensity. This system had three light proof pens each with feeders or waterers but different light intensities. There was a connecting transit pen with a light intensity of 1 to 2 lux. This allowed birds access to the pens each with feeders or waterers. There were markedly more chickens observed in the pens each with feeders or waterers and a light intensity of 20 lux than 5 lux. Moreover, more feed was consumed in the 20 lux pens than 5 pens. There were also high numbers of chickens in the transit compartment with its low light intensity (1 to 2 lux) and no feeders or waterers. Broiler chickens exhibited a preference for 20 lux light intensity for feeding compared to 5 lux light intensity. The present study supports the view that there should be a light intensity of at least 20 lux for the areas around the feeders and also suggests that light intensity may be reduced in other areas for resting and other activities.

Glyphosate [N-(phosphonomethyl)glycine] significantly decreased the chlorophyll content of field-grown soybeans (Glycine max L. Merr. ‘Williams’) within 48 h after a 2.24-kg/ha treatment. In laboratory studies, 0.0001, 0.001, 0.01, 0.1, and 1 mM glyphosate reduced chlorophyll content of 7-day-old etiolated barley (Hordeum vulgare L. ‘Barsoy’) shoots 8, 12, 25, 49, and 77%, respectively, following 8 h dark incubation and 24 h illumination. Reduction of chlorophyll accumulation ranged from 6% with 0.001 mM glyphosate to 82% with 1.0 mM glyphosate. In studies with 8-day-old etiolated corn (Zea mays L. ‘Pioneer Brand 3535’) shoots, 0.1, 1.0, and 10.0 mM glyphosate decreased chlorophyll content of corn shoots 24, 42, and 50%, respectively, after 12 h of illumination. The rate of chlorophyll accumulation in corn shoots was significantly reduced 64% by 1.0 mM glyphosate over a 15-h illumination period. These rapid and substantial effects on chlorophyll accumulation suggest that interference with greening may be important in the mechanism of action of glyphosate.

Retinex theory explains how the human visual system perceives colors. The goal of retinex is to decompose the reflectance and the illumination from the given images and thereby compensating for non-uniform lighting. The existing methods for retinex usually use a single image with a fixed exposure to restore the reflectance of the image. In this paper, we propose a variational model for retinex problem by utilizing multi-exposure images of a given scene. The existence and uniqueness of the solutions of the proposed model have been elaborated. An alternating minimization method is constructed to solve the proposed model and its convergence is also demonstrated. The experimental results show that the proposed method is effective for reflectance recovery in retinex problem.

In this paper, we study to use nonlocal bounded variation (NLBV) techniques to decompose an image intensity into the illumination and reflectance components. By considering spatial smoothness of the illumination component and nonlocal total variation (NLTV) of the reflectance component in the decomposition framework, an energy functional is constructed. We establish the theoretical results of the space of NLBV functions such as lower semicontinuity, approximation and compactness. These essential properties of NLBV functions are important tools to show the existence of solution of the proposed energy functional. Experimental results on both grey-level and color images are shown to illustrate the usefulness of the nonlocal total variation image decomposition model, and demonstrate the performance of the proposed method is better than the other testing methods.

Illumination using artificial light sources is common in these days. Many manufacturesare paying for the design of lamps depending on high efficacy and low UV hazards. Thisresearch is focusing on the most useable lamps in the Egyptian markets; high pressuremercury (HPM), metal Halide (MH), and high pressure sodium (HPS). A set up for relativespectral power distribution based on single monochromator and UVA silicon detector forabsolute irradiance measurements are used. The absolute irradiance in (W/m2) in UVA region of the lamps andtheir accompanied standard uncertainty are evaluated.

Several problematic specimens, especially when composed of a complex three-dimensional architecture or very high or ultralow ranges in regional thickness and density, can be observed in improved clarity and precision when universal variable brightfield–darkfield contrast (UVBDC) is used. In this method, two different partial images are optically superimposed and interfere with each other, contributing to complementary visual information: a brightfield and a darkfield image. These images can be generated with concentric-peripheral, paraxial, or axial illuminating light. In all variants, variable transitions between bright- and darkfield are achievable. By use of a pancratic condenser (zoom system), the illuminating light can be universally adjusted and optimally adapted to each type of specimen and each type of objective (glass and mirror lenses). The concentric-peripheral variant is preferably carried out with normal glass lenses, the axial variant with mirror lenses. Glass lenses can also be used for UVBDC based on axial or paraxial light when combined with a special contrast tube, which is described in detail. Which technical variant of UVBDC might lead to the best result may be determined by the particular properties of the specimen, but all techniques described promise significant improvements in image quality and visual information.

A system for illuminating a sample in situ with visible and ultraviolet light inside a transmission electron microscope was devised to study photocatalysts. There are many mechanical and optical factors that must be considered when designing and building such a system. Some of the restrictions posed by the electron microscope column are significant, and care must be taken not to degrade the microscope's electron-optical performance or to unduly restrict the other capabilities of the microscope. We discuss the nature of the design considerations, as well as the practical implementation and characterization of a solution. The system that has been added to an environmental transmission electron microscope includes a high brightness broadband light source with optical filters, a fiber to guide the light to the sample, and a mechanism for precisely aligning the fiber tip.

Variable phase dark-field contrast has been developed as an illumination technique in light microscopy, which promises significant improvements and a higher variability in imaging of several transparent specimens. In this method, a phase contrast image is optically superimposed on a dark-field image so that a partial image based on the principal zeroth-order maximum (phase contrast) interferes with an image that is based on the secondary maxima (dark field). The background brightness and character of the resulting image can be continuously modulated from a phase-contrast-dominated to a dark-field-dominated character. The condenser aperture diaphragm can be used for modulations of the image's appearance. Specimens can either be illuminated concentrically or obliquely (eccentrically) when parts of the illuminating light beams are covered and blocked. Moreover, a bright-field-like partial image can be added. In this way, the illumination can be optimally adjusted to the specific properties of the specimen. The techniques described can lead to improved visual information especially in biological specimens consisting of phase structures and additional light-absorbing or -reflecting components. Moreover, the specimen's three-dimensionality can be accentuated with improved clarity because the illuminating light beams associated with phase contrast and dark field run to the specimen at different angles of incidence.

Organic light-emitting diodes (OLEDs) are developing into a competitive alternative to conventional light sources. Nevertheless, OLEDs need further improvement in terms of efficiency and color rendering for lighting applications. Fluorescent blue emitters allow deep blue emission and high stability, while phosphorescent blue emitter still suffer from insufficient stability. The concept of triplet harvesting is the key for achieving internal quantum efficiencies up to 100 % and simultaneously benefiting from the advantages of fluorescent blue emitters. Here, we present a stacked OLED consisting of two units comprising four different emitters in total. The first unit takes advantage of the concept of triplet harvesting and combines the light emission of a fluorescent blue and a phosphorescent red emitter. The second unit emits light from a single emission layer consisting of a matrix doped with phosphorescent green and yellow emitters. With this approach, we reach white color coordinates close to the standard illuminant A and a color rendering index of above 75. The presented devices are characterized by high luminous efficacies of above 30 lm/W on standard glass substrates without outcoupling enhancement.