Using 2- and 2 -dimensional seed filling in view lattice to accelerate volumetric rendering

In this paper we propose new methods for calculating the projection of an opaque 3-dimensional 6-connected volumetric object into a two-dimensional view using 2- and 2 -dimensional seed-filling in the view space. When a 3-dimensional volumetric data set is sampled by parallel rays at a resolution exceeding the Nyquist ratio, the 6-connectivity of objects is maintained from volume lattice to view lattice. Given a seed point for each 6-connected object in the volumetric data set, a seed-filling algorithm may access all sample points in view lattice, while simultaneously composing the rendered view. The algorithms presented in this paper minimize the number of voxels that need to be processed. We implemented these methods on a general purpose computer architecture and tested them with several artificial and real-life medical volumetric data sets. It is shown that the algorithms may be used to speed up the parallel ray casting of opaque medical objects. The actual frame rate achieved by the combined method allows interactive (10 frames/sec) rotation of the object on a common single-processor personal computer without specialized hardware.     

Elevated temperature thermal conductivities of some as-cast and austempered cast irons

The aim of this study was to provide insight on thermal conductivity of three cast iron groups, namely lamellar, compacted and spheroidal graphite irons at elevated temperatures up to 673?K (400°C) in as-cast and austempered states. Austempering treatments increased mechanical properties of all the studied materials while decreasing thermal conductivity across the line. The effects of austempering on conductivity were lower for grey and compacted graphite iron than for spheroidal graphite irons. The results indicate that heat treating can be a viable option in increasing cast iron performance in thermally stressed applications. One ferritic low-silicon spheroidal graphite iron surpassed lamellar graphite iron in conductivity at elevated temperatures, while high-silicon spheroidal graphite irons exhibited low conductivities.     

Carbonyl‐precursor‐based W/Al2O3 and CoW/Al2O3 catalysts: characterization by temperature‐programmed methods

Carbonyl‐precursor‐based W/Al₂O₃ and bimetallic CoW/Al₂O₃ catalysts were prepared by gas‐phase adsorption in a fluidized‐bed reactor. The surface species formed during the gradual and controlled preparation process were studied by temperature‐programmed methods. Interactions on the surface were investigated as a function of metal loading by temperature‐programmed oxidation (TPO) and oxygen pulse chemisorption (PCO). A clear relationship was observed between decarbonylation treatment and the tungsten species formed. Total acidity of the samples was determined by temperature‐programmed desorption of ammonia (NH₃‐TPD). The NH₃‐TPD measurements, together with previous activity studies, suggest a relationship between total acidity and hydrotreating activity. The results of PCO and NH₃‐TPD measurements indicate that when the controlled gas‐phase preparation method is applied to zerovalent carbonyl precursor, the unfavourable formation of tungsten oxide can be minimized. This revised version was published online in July 2006 with corrections to the Cover Date.     

On time-symmetry in cellular automata

The notion of reversibility has been intensively studied in the field of cellular automata (CA), for several reasons. However, a related notion found in physical theories has been so far neglected, not only in CA, but generally in discrete dynamical systems. This is the notion of time-symmetry, which refers to the inability of distinguishing between backward and forward time directions. Here we formalize it in the context of CA, and study some of its basic properties. We also show how some well-known CA fit into the class of time-symmetric CA, and provide a number of results on the relation between this and other classes of CA. The existence of an intrinsically universal time-symmetric CA within the class of reversible CA is proved. Finally, we show the undecidability of time-symmetry for CA of dimension 2 or higher, even within the class of reversible CA. The case of dimension 1 is one of several open questions discussed in the conclusions.     

Multifunction spectrometer for optical inspection of red wine

The main goal of this study was to develop an apparatus that makes it possible to measure both, color, refractive index and light scattering (turbidity) of red wines using a single device only. Typically such measurement of red wine quality requires three different measurement devices. As an example of the efficiency of the present device we studied the change of the thermo-optical and time-dependent optical properties of red wine samples. Here we report on change of optical properties of two Merlot wine samples, which were obtained by opening authentic red wine bottles and preserving a set of samples both at room and refrigerator temperature for 26 days, respectively. The interesting feature with both red wine samples was that the light scattering, i.e. the turbidity of the samples, increased as a function of time due to oxidation process. It is suggested that the multifunction spectrophotometer can be applied for optical inspection of red and other wine products.     

A Single Chip 160 Mbit/s Cable Communication Circuit Including a Gain Controlled Equalizer and a Data Regenerating PFLL

In this paper a single chip transmitter and receiver interface circuit for 160 Mbit/s CMI-coded data transmission is presented. The receiver circuit includes a 12 dB cable equalizer to compensate for nonconstant cable attenuations. There is also a PFLL for data regeneration and to extract a 320 MHz oscillator clock signal. The frequency characteristics of the equalizer are controlled with an automatic gain control loop (AGC). The PFLL is a combination of two separate control loops, the purpose of which is to keep the integrated oscillator on the narrow locking range of the data loop. The frequency loop has been designed with a frequency detector to avoid interferences between the two control loops. The transmitter includes a cable driver supplying a stable 1 Vpp signal amplitude to the transmission line and also a PLL to extract a 320 MHz clock signal.     

Chiral donor–π-acceptor azobenzene dyes

Four chiral donor–π-acceptor azobenzene dye conjugates were synthesized and characterized. Chiral moieties, namely (S)-(+)-2-(6-methoxy-2-naphthyl)propionic acid (naproxen) and (S)-2-aminopropionic acid (l-alanine), were attached to either the donor end or the acceptor site of the azo compound using ester or amide bonds, respectively. The structures of the molecules were verified using ¹H NMR, ¹³C NMR and ESI TOF mass spectrometry; spectral properties were evaluated with UV–vis and CD spectrometry whilst thermal stability was determined by TGA. The compounds displayed a broad absorption maximum in the visible region between 433 and 483 nm. All compounds showed relatively high thermal stability, decomposition temperatures being ～200 °C.     

Scalable Parallel Memory Architectures for Video Coding

Current video compression standards, which process frames macroblock by macroblock, employ several processing functions to achieve the compression. These functions refer to data memory address space in different ways. E.g., performing motion estimation and motion compensation functions requires many times data accesses unaligned to word boundaries. On the other hand, Discrete Cosine Transformation (DCT) and inverse of it (IDCT) for 8 × 8 block can be performed first for rows and then for columns. Thus, transposition is needed between these two stages. Among other things, parallel memory architecture can provide a solution for these tasks. In our other paper, we shortly surveyed parallel memory architectures and proposed parallel memory architecture designs for different data path widths for video coding applications. In this paper, we construct video coding function examples by using the proposed parallel data memory efficiently. Furthermore, performance and implementation cost of the parallel memory architecture are estimated and compared to more conventional memory architectures. The examples are given for different data bus widths (16, 32, 64, and 128 bits). We show that the parallel memory can keep the data path fully utilized in many video coding function implementations. This ensures high-speed operation and full utilization of the processing resources.     

Large‐Scale Roll‐to‐Roll Patterned Oxygen Indicators for Modified Atmosphere Packages

We demonstrate roll‐to‐roll fabrication of ultraviolet A light‐activated colorimetric oxygen indicators on paper and plastic substrates. Such large‐scale, cost‐effective and non‐toxic oxygen indicator and production method can find applications as a very low‐cost leakage indicator for modified atmosphere packages by printing the material directly or gluing the pre‐printed indicator label inside the lid. The introduction of leakage indicators onto all modified atmosphere packages could result in improved food safety and reduced food spoilage. Copyright © 2017 John Wiley & Sons, Ltd.