Internal energy flow analysis within a single effect sorption heat pump

The knowledge of the characteristics of unused, excess and untapped exergy allows a thorough analysis of internal energy flows distribution within a sorption heat pump. It can be applied to any system based on gas–liquid absorption, adsorption or solid–gas reaction as well as to any process based on the internal recycling of the energy flux. It can also be applied for the case of a simple effect ideal machine, in particular in the definition of processes where the COP is larger than 2: the levels at which the initial exergy is downgraded on the one hand, as well as, the upgraded excess exergy produced on the other allows the designer to make a judicious choice of a system.     

Catalytic Ozonation of Acid Red 88 from Aqueous Solutions

Degradation of Acid Red 88 (AR 88) azo dye in water was investigated in laboratory-scale experiments in presence of three metal oxide supported catalyst. Oxidation process was monitorized in terms of colour, chemical oxygen demand (COD) and total organic carbon (TOC) removals. Influence of catalysts type and aqueous solution pH were studied.     

Electrochemical behaviour of polyacrylic acid coated gold electrodes: An application to remove heavy metal ions from wastewater

An efficient and low cost preparation method (Diazonium-Induced Anchoring Process) to graft polyacrylic acid (PAA) on the gold substrate has been reported. IR, XPS and AFM techniques were used to characterize the obtained polymer film. The interfacial electrochemistry of the PAA coated gold electrodes was studied by means of impedance spectroscopy and cyclic voltammetry transition techniques. The ability of PAA-grafted onto a gold electrode to reversibly bind or release metal ions was confirmed. As a broad-range chelating material, PAA is able to capture several heavy metal ions at low concentration. The release of those metal ions from the grafted PAA film was obtained under electro-induced-acidification by applying an anodic potential at the electrode to promote a localized water electrolysis. Application of electrochemical-pH-switchable PAA films can be considered within the field of heavy metal waste treatments.     

Fully depleted double-gate MSDRAM cell with additional nonvolatile functionality

We demonstrate a new fully depleted (FD) double-gate (DG) MSDRAM cell, which features SONOS type storage node at the back-gate (control-gate). This single-transistor cell, based on the meta-stable dip (MSD) hysteresis effect, can also be operated in non-volatile memory (NVM) mode. The NVM functionality is achieved by Fowler–Nordheim tunneling hole injection into the nitride storage node; the injected holes induce a permanent inversion layer in silicon body. The proposed device shows a large current ratio between ‘1’ and ‘0’ states (～10³) and a wide memory window (～3 V). The effect of the NVM functionality on the MSD hysteresis was investigated and combined with the effect of the control-gate bias. The SONOS charging can be used for replacing the second gate (i.e. enabling single-gate MSDRAM) or for achieving ‘unified’ memory operation.     

δ-Bit serial binary addition with linear threshold networks

In this paper we investigate δ-bit serial addition in the context of feed-forward linear threshold gate based networks. We show that twon-bit operands can be added in $2\left\lceil {\sqrt n } \right\rceil $ overall delay with a feed-forward network constructed with $\left\lceil {\sqrt n } \right\rceil + 1$ linear threshold gates and $\frac{1}{2}\left( {5\left\lceil {\sqrt n } \right\rceil ^2 + 9\left\lceil {\sqrt n } \right\rceil } \right) + 2$ latches. The maximum weight value is $2^{\left\lceil {\sqrt n } \right\rceil } $ and the maximum fan-in is $3\left\lceil {\sqrt n } \right\rceil + 1$ . We also investigate the implications our scheme have to the performance and the cost under small weights and small fan-in requirements. We deduce that if the weight values are to be limited by a constantW, twon-bit operands can be added in $\left[ {\log W} \right] + \tfrac{n}{{\left[ {\log W} \right]}}$ overall delay with a feed-forward network that has the implementation cost [logW]+1, in terms of linear threshold gates, $\tfrac{1}{2}(5[\log W]^2 + 9[\log W]) + 2$ in terms of latches and a maximum fan-in of 3[logW]+1. We also prove that, if the fan-in values are to be limited by a constantF+1, twon-bit operands can be added in $[\tfrac{F}{3}] + \tfrac{n}{{[\tfrac{F}{3}]}}$ overall delay with a feed-forward network that has the implementation cost $[\tfrac{F}{3}] + 1$ , in terms of linear threshold gates, $\tfrac{1}{2}(5[\tfrac{F}{3}]^2 + 9[\tfrac{F}{3}]) + 2$ in terms of latches, and a maximum weight value of $2^{[\tfrac{F}{3}]} $ . An asymptotic bound of $O(\tfrac{n}{{\log n}})$ is derived for the addition overall delay in the case that the weight values have to be linearly bounded, i.e., in the order ofO(n). The implementation cost in this case is in the order ofO(logn), in terms of linear threshold gates, and in the order ofO(log² n), in terms of latches. The maximum fan-in is in the order ofO(logn). Finally, a partition technique, that substantially reduces the overall cost of the implementation for all the schemes in terms of delay, latches, weights, and fan-in with some few additional threshold gates, is also presented.     

Coherent FMCW reflectometry using a temperature tuned Nd:YAG ringlaser

A long-coherence-length, diode-pumped, monolithic Nd:YAG laser operating at 1.32 μm is used to perform coherent FMCW (frequency-modulated continuous wave) reflectometry measurements. Compared with semiconductor-based lasers, the low phase noise of the Nd:YAG source offers greatly increased distance range combined with increased sensitivity to optical reflections. Measurement of Rayleigh backscatter from 50 km of fiber is demonstrated with over 60 dB of two-way optical dynamic range. Two-point spatial resolution is demonstrated to be better than 10 cm. This source and coherent measurement technique may have potential for both short and long-haul reflectometry applications     

Compositional,Dynamic Cache Management for Embedded Chip Multiprocessors

This paper proposes a dynamic cache repartitioning technique that enhances compositionality on platforms executing media applications with multiple utilization scenarios. Because the repartitioning between scenarios requires a cache flush, two undesired effects may occur: (1) in particular, the execution of critical tasks may be disturbed and (2) in general, a performance penalty is involved. To cope with these effects we propose a method which: (1) determines, at design time, the cache footprint of each tasks, such that it creates the premises for critical tasks safety, and minimum flush in general, and (2) enforces, at run-time, the design time determined cache footprints and further decreases the flush penalty. We implement our dynamic cache management strategy on a CAKE multiprocessor with 4 Trimedia cores. The experimental workload consists of 6 multimedia applications, each of which formed by multiple tasks belonging to an extended MediaBench suite. We found on average that: (1) the relative variations of critical tasks execution time are less than 0.1%, regardless of the scenario switching frequency, (2) for realistic scenario switching frequencies the inter-task cache interference is at most 4% for the repartitioned cache, whereas for the shared cache it reaches 68%, and (3) the off-chip memory traffic reduces with 60%, and the performance (in cycles per instruction) enhances with 10%, when compared with the shared cache.

High-power semiconductor edge-emitting light-emitting diodes foroptical low coherence reflectometry

A new semiconductor source was designed for optical low coherence reflectometry, increasing the sidelobe-free dynamic range by three to five orders of magnitude compared to conventional EELED's. Reflectivities internal to an optical fiber circuit separated by as much as eight orders of magnitude can now be detected at wavelengths of 1.3 and 1.55 μm, using compact semiconductor sources. For applications not requiring sidelobe-free operation, the same devices can be operated at high current (200 mA) and low temperatures (near 0°C) to produce nearly 1 mW of 1.5 μm emission coupled into single-mode fiber. The resulting wavelength spectrum is smooth, enabling fiber-based absorption spectral measurements     

Iso-shaping rigid bodies for estimating their motion from image sequences

In many medical imaging applications, due to the limited field of view of imaging devices, acquired images often include only a part of a structure. In such situations, it is impossible to guarantee that the images will contain exactly the same physical extent of the structure at different scans, which leads to difficulties in registration and in many other tasks, such as the analysis of the morphology, architecture, and kinematics of the structures. To facilitate such analysis, we developed a general method, referred to as iso-shaping, that generates structures of the same shape from segmented image sequences. The basis for this method is to automatically find a set of key points, called shape centers, in the segmented partial anatomic structure such that these points are present in all images and that they represent the same physical location in the object, and then trim the structure using these points as reference. The application area considered here is the analysis of the morphology, architecture, and kinematics of the joints of the foot from magnetic resonance images acquired at different joint positions and load conditions. The accuracy of the method is analyzed by utilizing ten data sets for iso-shaping the tibia and the fibula via four evaluative experiments. The analysis indicates that iso-shaping produces results as predicted by the theoretical framework.