Inhibited Oxidation of Lipids II: Comparison of the Antioxidative Properties of Some Hydroxy Derivatives of Benzoic and Cinnamic Acids

The antioxidative properties of p-hydroxy-benzoic acid, vanillic acid, syringic acid, 3,4-dihydroxy-benzoic acid, p-coumaric acid, ferulic acid, sinapic acid and caffeic acid in lard autoxidation at 100°C are compared. The effect of phenolic acids is investigated within the concentration range 0.02 – 0.20 wt %. It is proved that the derivatives of the benzoic acid have weaker inhibiting properties than is the case of the corresponding analogues of the cinnamic acid due to the more active participation of the inhibitor in the elementary reactions of propagation and initiation of the radical chain process. The activity (a complex parameter demonstrating the efficiency and strength of the antioxidant) of the phenolic acids investigated decreases in the sequence: caffeic acid >3,4-dihydroxy-benzoic acid > sinapic acid > syringic acid>ferulic acid>p-coumaric acid>vanillic acid. The increase in concentration of the acids investigated is most advisable in the case of sinapic, syringic and ferulic acids which are not consumed in side reactions.     

A General Framework for the Selection of World Coordinate Systems in Perspective and Catadioptric Imaging Applications

An imaging system with a single effective viewpoint is called a central projection system. The conventional perspective camera is an example of central projection system. A catadioptric realization of omnidirectional vision combines reflective surfaces with lenses. Catadioptric systems with an unique projection center are also examples of central projection systems. Whenever an image is acquired, points in 3D space are mapped into points in the 2D image plane. The image formation process represents a transformation from ³ to ², and mathematical models can be used to describe it. This paper discusses the definition of world coordinate systems that simplify the modeling of general central projection imaging. We show that an adequate choice of the world coordinate reference system can be highly advantageous. Such a choice does not imply that new information will be available in the images. Instead the geometric transformations will be represented in a common and more compact framework, while simultaneously enabling newer insights. The first part of the paper focuses on static imaging systems that include both perspective cameras and catadioptric systems. A systematic approach to select the world reference frame is presented. In particular we derive coordinate systems that satisfy two differential constraints (the compactness and the decoupling constraints). These coordinate systems have several advantages for the representation of the transformations between the 3D world and the image plane. The second part of the paper applies the derived mathematical framework to active tracking of moving targets. In applications of visual control of motion the relationship between motion in the scene and image motion must be established. In the case of active tracking of moving targets these relationships become more complex due to camera motion. Suitable world coordinate reference systems are defined for three distinct situations: perspective camera with planar translation motion, perspective camera with pan and tilt rotation motion, and catadioptric imaging system rotating around an axis going through the effective viewpoint and the camera center. Position and velocity equations relating image motion, camera motion and target 3D motion are derived and discussed. Control laws to perform active tracking of moving targets using visual information are established.     

Corrosion and stress corrosion cracking of amorphous FeNiMoxB alloys in several neutral and acidic media

Corrosion and stress corrosion cracking behaviour of a series of amorphous iron alloys FeNiMo_xB (x = 0, 2, 4, 8.5) has been investigated in several neutral and acidic media. In particular in aqueous solutions of ferric chloride, potassium tetrathionate and sulphuric acid containing chlorides stress corrosion cracking (SCC) has been studied by means of constant strain tests and corrosion rates have been evaluated by means of weight loss measurements. In several cases polarization curves have been recorded in order to clarify the electrochemical behaviour of the amorphous alloys. SEM observations of the fracture surfaces have been performed. It has been observed that the glassy alloys under investigation are susceptible to SCC at free corrosion potential in all the environments. SCC has been observed on specimens cathodically and anodically polarized in sulphuric acid containing chlorides. Hydrogen embrittlement can reasonably be considered responsible of the SCC phenomenon, except in sulphuric acid solution on specimens anodically polarized and in iron chloride solution. A deleterious effect of molybdenum has been noted on the corrosion rates of unstressed specimens and on the time to failures of stressed samples.     

A 400-MHz S/390 microprocessor

A microprocessor implementing IBM S/390 architecture operates in a 10+2 way system at frequencies up to 411 MHz (2.43 ns). The chip is fabricated in a 0.2-μm L_eff CMOS technology with five layers of metal and tungsten local interconnect. The chip size is 17.35 mm×17.30 mm with about 7.8 million transistors. The power supply is 2.5 V and measured power dissipation at 300 MHz is 37 W. The microprocessor features two instruction units (IUs), two fixed point units (FXUs), two floating point units (FPUs), a buffer control element (BCE) with a unified 64-KB L1 cache, and a register unit (RU). The microprocessor dispatches one instruction per cycle. The dual-instruction, fixed, and floating point units are used to check each other to increase reliability and not for improved performance. A phase-locked-loop (PLL) provides a processor clock that runs at 2× the system bus frequency. High-frequency operation was achieved through careful static circuit design and timing optimization, along with limited use of dynamic circuits for highly critical functions, and several different clocking/latching strategies for cycle time reduction. Timing-driven synthesis and placement of the control logic provided the maximum flexibility with minimum turnaround time. Extensive use of self-resetting CMOS (SRCMOS) circuits in the on-chip L1 cache provides a 2.0-ns access time and up to 500 MHz operation     

Patent Claims Revisited: Examiners and Trolls

In this column, the author revisits the writing of claims, and demonstrate two other styles of writing them. In one style, he shows how to write a more narrow and focused claim. In the other style, he shows how to write claims that are beyond broad--claims that can be written prior to actually inventing anything.     

A novel multimodal interface for improving visually impaired people’s web accessibility

This paper introduces a novel interface designed to help blind and visually impaired people to explore and navigate on the Web. In contrast to traditionally used assistive tools, such as screen readers and magnifiers, the new interface employs a combination of both audio and haptic features to provide spatial and navigational information to users. The haptic features are presented via a low-cost force feedback mouse allowing blind people to interact with the Web, in a similar fashion to their sighted counterparts. The audio provides navigational and textual information through the use of non-speech sounds and synthesised speech. Interacting with the multimodal interface offers a novel experience to target users, especially to those with total blindness. A series of experiments have been conducted to ascertain the usability of the interface and compare its performance to that of a traditional screen reader. Results have shown the advantages that the new multimodal interface offers blind and visually impaired people. This includes the enhanced perception of the spatial layout of Web pages, and navigation towards elements on a page. Certain issues regarding the design of the haptic and audio features raised in the evaluation are discussed and presented in terms of recommendations for future work.     

Magnetic Nanosystem for Cancer Therapy Using Oncocalyxone A,an Antitomour Secondary Metabolite Isolated from a Brazilian Plant

This paper describes the investigation and development of a novel magnetic drug delivery nanosystem (labeled as MO-20) for cancer therapy. The drug employed was oncocalyxone A (onco A), which was isolated from Auxemma oncocalyx, an endemic Brazilian plant. It has a series of pharmacological properties: antioxidant, cytotoxic, analgesic, anti-inflammatory, antitumor and antiplatelet. Onco A was associated with magnetite nanoparticles in order to obtain magnetic properties. The components of MO-20 were characterized by XRD, FTIR, TGA, TEM and Magnetization curves. The MO-20 presented a size of about 30 nm and globular morphology. In addition, drug releasing experiments were performed, where it was observed the presence of the anomalous transport. The results found in this work showed the potential of onco A for future applications of the MO-20 as a new magnetic drug release nanosystem for cancer treatment.     

Advances in Polarizer Technology for Terahertz Frequency Applications

As investigations into potential applications of terahertz technology grow, there is an increasing need for improved terahertz optical components such as polarizers. To determine the optical properties of a sample accurately, the polarization properties of the light must also be known accurately. Many terahertz emitters will have both horizontal and vertical polarization components and often assumptions are made about device characteristics without measuring them-even the position of excitation beam on the photoconductive emitter can affect the resulting terahertz electric field and so the exact optical properties of a given device will vary depending on how they are configured. Polarizers operating at terahertz frequencies can be used to characterize the electric field accurately or remove unwanted components as long as the polarizer is of sufficiently high performance. In this paper we review the key properties of polarizers and look at recent advances in their design and development at terahertz frequencies.