NIST 0:45 reflectometer

The NIST 0:45 reflectometer measures the spectral reflectance factor at an influx angle of 0° and an efflux angle of 45° of colored, nonfluorescent specimens at room temperature, with widths ranging from 3 to 10 cm and heights from 3 to 20 cm and with an uncertainty of less than 0.5 in color difference units. Published in 2008 by John Wiley & Sons, Inc. Col Res Appl, 33, 94–99, 2008     

Uncertainty analysis for the NIST 0:45 Reflectometer

Sets of color tiles are available from the National Institute of Standards and Technology calibrated using the NIST 0:45 Reflectometer. The uncertainties associated with the measured values for the color tiles are an indispensable component of the calibration report that accompanies these tiles. A systematic, analytical approach developed previously was applied to the particular case of the reference instrument and color tile set, taking into account the operation and characteristics of the instrument and the spectral properties of the set. The primary sources of uncertainty were identified, and the resulting uncertainties in the color space values L*, a*, and b* were determined. In general, the uncertainties are lowest for those color tiles whose reflectance factors are nearly constant with wavelength. Published in 2008 by John Wiley & Sons, Inc. Col Res Appl, 33, 100–107, 2008     

Quantum walks: a comprehensive review

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete-time quantum walks.     

Nitric Oxide (NO) Scaffolds the Peroxisomal Protein–Protein Interaction Network in Higher Plants

The peroxisome is a single-membrane subcellular compartment present in almost all eukaryotic cells from simple protists and fungi to complex organisms such as higher plants and animals. Historically, the name of the peroxisome came from a subcellular structure that contained high levels of hydrogen peroxide (H₂O₂) and the antioxidant enzyme catalase, which indicated that this organelle had basically an oxidative metabolism. During the last 20 years, it has been shown that plant peroxisomes also contain nitric oxide (NO), a radical molecule than leads to a family of derived molecules designated as reactive nitrogen species (RNS). These reactive species can mediate post-translational modifications (PTMs) of proteins, such as S-nitrosation and tyrosine nitration, thus affecting their function. This review aims to provide a comprehensive overview of how NO could affect peroxisomal metabolism and its internal protein-protein interactions (PPIs). Remarkably, many of the identified NO-target proteins in plant peroxisomes are involved in the metabolism of reactive oxygen species (ROS), either in its generation or its scavenging. Therefore, it is proposed that NO is a molecule with signaling properties with the capacity to modulate the peroxisomal protein-protein network and consequently the peroxisomal functions, especially under adverse environmental conditions.     

Enlargement of the micropores of a caking bituminous coal by controlled oxidation

In a study of the enlargement of pores of coals it has been found that treatment of a bituminous coal (PSOC No. 371, from the Pennsylvania State University Coal Section) with a 5:95 O₂:N₂ stream 4 h at 400 °C increases the surface area as measured by nitrogen adsorption at 77K by a factor of at least 50 to a value 52 m² g^?1. The increase in pore size was accompanied by a 9.7% weight loss. Simultaneously, the area as measured by carbon dioxide at 195K increased from 61 to 136 m² g^?1 and that measured by carbon dioxide at room temperature increased from 125 to 237 m² g^?1. Attempts to enlarge the pores by oxidation with hydrogen peroxide or ozone were unsuccessful. A Pittsburgh coal subject to a small percentage of oxygen in nitrogen or steam at 300 to 400 °C showed a surface area as measured by nitrogen adsorption of less than 1 m² g^?1 both before and after such pretreatment. This same coal with a 5:95 O₂:N₂ stream for 4 h at 450 °C showed a surface area of 110 m² g^?1 measured by nitrogen adsorption at 77K.     

Energy Efficiency of an Indirect Thermally Coupled Distillation Sequence

Several thermally coupled distillation sequences have been proposed to improve the thermal inefficiency of conventional distillation sequences. Particularly, for the separation of ternary mixtures, structures that perform a lateral extraction in one of the columns of the integrated arrangement have been shown to provide significant energy savings. The structure of existing sequences, based on conventional distillation columns, might provide the basis for alternate thermally coupled designs. In this paper, it is shown how a thermally coupled system derived from an indirect conventional sequence can provide energy savings through a proper optimization of the interconnecting streams.     

Compatibility Relations of A1203 in the System Zr02-Al203-Si02-CaO

Compatibility relations of Al₂0₃ in the quaternary system Zr02-Al₂0₃-Si0₂-CaO were studied by firing and quenching followed by microscopy and energy-dispersive X-ray examination. A projection of the boundary surface of the primary crystallization volume of Al₂0₃ was constructed in terms of the CaO, Si0₂, and Zr0₂ contents of the mixtures recalculated to 100 wt%. Two invariant points, where four solids coexist with a liquid phase, are defined, and the positions of the isotherms were established.     

Effect of oil degradation during frying on the color of fried, battered squid rings

Oil degradation caused by the number of fryings performed and the effect of oil degradation on the color of fried battered squid rings were studied. Spectrophotometric techniques with absorbance in the UV and visible ranges, and iodine, peroxide, and acid values were used to determine oil degradation. Determination of various CIELAB parameters in order to study the external color of the fried battered squid rings revealed no differences in color due to the number of fryings. A study of the color of the battered squid rings at various frying times and temperatures showed significant differences for both variables. Although there was some degradation in the oil after 20 fryings, appearing as a slight darkening, it did not affect the final color of the fried, battered squid rings.     

Geochemical implications of trace elements and sulfur in the saturate, aromatic and resin fractions of crude oil from the Mara and Mara Oeste fields, Venezuela

Ten trace elements (Cr, Zn, Fe, Mn, Cu, Co, Ni, Mo, V and Sr) and sulfur were determined in the saturate, aromatic and resin fractions of 15 crude oils from Mara (DM) and Mara Oeste (DMO) fields of the Maracaibo Basin, Venezuela. The oils studied are classified as unaltered or altered by biodegradation. In the altered oil, the depletion of n-alkanes, the absence of isoprenoids and the presence of steranes and hopanes unaltered by biodegradation are indicative of moderate biodegradation. The elements Zn, Fe, Mn, Cu, Ni, and Sr were detected in the saturated hydrocarbon fraction; Cr and V were detected in the aromatic fraction in addition to the above elements; whereas the elements detected for the resin fraction were Cr, Zn, Fe, Cu, Ni, Mo, V, and Sr. Co was not detected in any fractions of the oils analyzed. Sulfur was found in all fractions of the oils studied. It was proposed that Fe, Zn, Sr, and Mn could have entered the oil during migration or Fe, Zn and Mn as pollutants during oil extraction. Cr and Cu may be of biological origin and Mo could be incorporated into the reservoir through bacteria. Only S, V, and Ni in the resin fractions can be used as indicators of the origin and correlation of Mara and Mara Oeste oils. Based on the results obtained in this work, it can be established that the V/(V+Ni) ratio in the resin fraction can be used as a correlation parameter, for these oils.     

HumanTop: a multi-object tracking tabletop

In this paper, a computer vision based interactive multi-touch tabletop system called HumanTop is introduced. HumanTop implements a stereo camera vision subsystem which allows not only an accurate fingertip tracking algorithm but also a precise touch-over-the-working surface detection method. Based on a pair of visible spectra cameras, a novel synchronization circuit makes the camera caption and the image projection independent from each other, providing the minimum basis for the development of computer vision analysis based on visible spectrum cameras without any interference coming from the projector. The assembly of both cameras and the synchronization circuit is not only capable of performing an ad-hoc version of a depth camera, but it also introduces the recognition and tracking of textured planar objects, even when contents are projected over them. On the other hand HumanTop supports the tracking of sheets of paper and ID-code markers. This set of features makes the HumanTop a comprehensive, intuitive and versatile augmented tabletop that provides multitouch interaction with projective augmented reality on any flat surface. As an example to exploit all the capabilities of HumanTop, an educational application has been developed using an augmented book as a launcher to different didactic contents. A pilot study in which 28 fifth graders participated is presented. Results about efficiency, usability/satisfaction and motivation are provided. These results suggest that HumanTop is an interesting platform for the development of educational contents.