Reducing of soft error effects on a MIPS-based dual-core processor

Photomineralisation of 2,4‐dichlorophenol (DCP) in aqueous solutions (10.0–100.0 mg/L of C) was systematically studied at 318 ± 3 K, in an annular laboratory‐scale reactor, by photocatalytic membranes immobilizing titanium dioxide, as a function of substrate concentration, and absorbed power per unit length of membrane. Kinetics of both substrate disappearance, to yield intermediates, and total organic carbon (TOC) disappearance, to yield carbon dioxide, were followed (first series of experiments). At a fixed value of irradiance (1.50 W⋅cm−1), other series of mineralization experiments were repeated (second series of experiments) by carrying out only analyses of chemical oxygen demand (COD), in order to compare modelling results of the two sets of experiments. In both sets of experiments, stoichiometric hydrogen peroxide was used as oxygen donor. For the first series of experiments, a kinetic model was employed, already validated in previous work, from which, by a set of differential equations, four final optimised parameters, k1 and K1, k2 and K2, were calculated. By these parameters, the whole kinetic profile could be fitted adequately. The influence of irradiance on k1 and k2 could be rationalised very well by this four‐parameter kinetic model. Modelling of quantum yields, as a function of irradiance, could also be carried out satisfactorily. As has been found previously for other kinds of substrates, modelling of quantum yields for DCP mineralization is consistent with kinetics of hydroxyl radicals reacting between themselves, leading to hydrogen peroxide, other than with substrate or intermediates leading finally to carbon dioxide, paralleled by a second competition kinetics involving superoxide radical anion. For the second series of experiments, on the contrary, the Langmuir‐Hinshelwood model was employed. Uncertainties of COD analyses, coupled with discrepancies of this model and with its inability to reproduce kinetics up to complete mineralization, are underlined.

With the development of satellite communications, on-board processing (OBP) obtains more and more attentions due to the increased efficiency and performance. However, the large amounts of digital circuits in the OBP transponders are sensitive to the high-energy particles in space radiation environments, which may cause various kinds of single event effect. Among these effects, single event upset (SEU) is the major potential reason for the instability of the satellite communication systems. Triple modular redundancy (TMR) is a classical and effective method for mitigating the SEU in digital circuits. However, since three identical logic modules and a voting circuit are needed in TMR, the overhead is so high that the scheme may not be applicable on the on-board digital processing platform with very limited area and power resources. Therefore, how to design a more cost-effective fault-tolerant method becomes a critical issue. Considering that FIR-like processing is frequently used on OBP platform, in this article, a dual modules (DM) plus checking module based on residue code (DM-CRC) architecture for SEU-tolerant FIR design is proposed. Although this architecture reduces the area overhead dramatically, we find that the fault missing rate is still high if single-sample checking (SSC) is used. To solve this problem, a Multi-sample checking DM-CRC (MSC-DM-CRC) is further proposed. Our analysis shows that the MSC-DM-CRC scheme can make the fault missing rate small enough without reducing the actual throughput. By simulations it is shown that, when the modulus for CRC is 7 and the number of samples for MSC is 4, the reduction of area overhead relative to TMR is over 20% and the fault missing rate is as low as 0.05%.

The aim of the work was to study the effect of various microelectronic structural and technological implementations to improve the field emission properties of the nano-carbon emitters. The field emission properties of vacuum diodes with nanodiamond-graphite emitters of different geometric shapes was researched. The nanodiamond-graphite layers deposition were carried out from ethanol vapor at low pressure using microwave plasma. Three series of experiments were studied. Researching of emission currents with flat cathodes on silicon wafer coated by nanodiamond-graphite layer were done in first series of experiments. In the second series of experiments, the electrical parameters of integrated field emission diodes with flat nanodiamond-graphite emitters was studied. In the third series of experiments, the electrical parameters of field emission with flat nanodiamond-graphite formed as a micro-sized needles or blades were studied. Vacuum emission studies were done at temperature 300K and pressure 1 × 10^-6 Torr. <br/> Threshold voltage from10-50V per micron and current density about 0.2 A/cm² were obtained in the first series of experiments. In the second and third series of experiments, a threshold voltage from 1 to 10V/ &mu;m and current density of 1.75 A/cm² were displayed. The greatest current density more than 20 A/cm² was obtained using a blade-type emitter.

Callus induction and later plant regeneration were studied in four widely grown garlic (Allium sativum L.) cultivars from Europe. Root segments from in vitro plantlets were used as starting material. In addition to cultivar effects, the effects of auxin and cytokinin levels and the position of the segments on the root were studied. There were no statistically significant differences among cultivars for the number of root segments that induced callus in the two series of experiments. The average induction frequency was 34.7% in the first series of experiments. Callus induction on apical root segments was significantly higher compared to callus induction on non-apical root segments in the second series of experiments. Two months after callus induction, callus lines were transferred to a regeneration medium consisting of Murashige and Skoog basal medium supplemented with 30gl−1 sucrose and 1 mgl−1 (4.6μM) kinetin. Calluses derived from different experiments were quite uniform with respect to their regeneration potential. Also it was found that our regeneration system was cultivar-independent. The average shoot regeneration frequency was 17.9% in the first series of experiments. Highly significant differences were found in the frequency of shoot regeneration among different callus induction treatments. When the cytokinin 6-(γ,γ-dimethylallylamino)purine (0.1mgl−1∶0.5 μM) was present during callus induction, shoot regeneration ranged from 30.10 to 47.60%. Shoot regeneration from callus induced on non-apical segments was higher, although not significant, compared to callus induction from apical root segments in the second series of experiments. All in all, an efficient callus induction and plant regeneration system was developed from both apical and non-apical segments taken along the entire length of the roots. This system has potential to be used for garlic transformation.

Hardware redundancy architecture based on reconfigurable logic blocks with persistent high reliability improvement

We are developing a 32-bit embedded processor core with soft error detection and recovery mechanisms. Adding a parity bit into pipeline registers makes it possible to detect single event upset in an processor core. Detection of 2-bit and less multiple bit upset and automatic correction of single event upset can be done with single error correction and double error detection code. These soft-error detection/recovery mechanisms cause cost/performance degradation. In this paper, probability of serious calculation failures occurred by SEU in an MIPS R3000 compatible processor core is evaluated. We investigate the probability using register transfer level simulation. The result shows that impacts of SEU to calculation result differ much, when SEU happens in a program counter, an instruction register or register files. Soft error detection/recovery mechanism of an embedded processor core can be selected automatically when permitted soft error rate of an application program is given as a specification.

In core-disruptive accidents of sodium-cooled fast reactors, fuel discharge from the core region reduces the possibility of severe re-criticality events. In-core coolant channels with large hydraulic diameters, such as the control-rod guide tube and a concept of the Fuel Assembly with Inner Duct Structure have a potential to provide effective fuel-discharge paths if effects of sodium in these paths on molten fuel discharge are limited. Two series of experiments were conducted to investigate fuel-discharge behaviour through the sodium-filled channels. In the first series of experiments, an alloy with low melting temperature was ejected into a water channel to clarify dominant phenomena for melt discharge through the coolant-filled channel and to develop methodologies for evaluating the effects of coolant on melt discharge. In the second series of experiments, a molten alumina was discharged through the sodium-filled channel in order to verify the applicability of the knowledge and evaluation methodologies obtained in the first series of experiments to the sodium-filled channel. These series of experiments showed that the discharge path can be entirely voided by the vaporisation of a part of the coolant at the initial melt discharge phase that this is followed by coolant vapour expansion and that melt penetrates significantly into the voided channel. Preliminary extrapolation of the present results to the in-core coolant channel suggests that the effects of the sodium on fuel discharge are limited and, therefore, in-core coolant channels will provide effective fuel-discharge paths for reducing neutronic activity.

In the present study, sand and expanded polystyrene (EPS) geofoam were evaluated as potential stabilizers in improving the swelling behaviour of bentonite. A comprehensive laboratory experimental programme was conducted on bentonite with a high swelling potential. Five dosage levels of sand and five different thickness of EPS geofoam were investigated in two stages of the experiments. In the first stage of testing, the effect of sand on the swelling pressure of bentonite was investigated by two series of experiments. In the first series of experiments, bentonite at optimum water content was mixed with sand in proportions of 20, 40, 60 and 80% by weight. In the second series of experiments, the same percentages of sand were used as in the first series of experiments but the sand and bentonite were not mixed together. The sand was placed on the sample of bentonite which was then compacted at optimum water content. In the second stage of testing, the effect of EPS geofoam on the swelling pressure of bentonite was investigated using different thicknesses of EPS geofoam placed on the sample of bentonite. These thicknesses were the same as the thicknesses of sand which was placed on the sample of bentonite in the second series experiments of the first stage. These experiments show that the expansive soil can be successfully stabilized by sand and EPS geofoam.

Adult domestic pigeons, with thermodes chronically implanted in the vertebral canal, were trained to walk on a treadmill. In the first series of experiments, EMG activity in a pectoral (M. pectoralis) and a femoral muscle (M. biceps femoris) was measured to determine if shivering could occur during exercise. When the spinal cord was cooled (36.2 +/- 0.5 degrees C) during exercise (0.6 km/h), pectoral muscle EMG activity increased by 80%, while femoral muscle EMG activity did not change significantly. EMG activity remained unchanged during exercise in control experiments where the spinal cord was not cooled. In the second series of experiments, the spinal cord was first cooled (36.1 +/- 0.5 degrees C) for 5 min in resting pigeons and then the treadmill was started. Spinal cord cooling during rest significantly increased pectoral muscle EMG activity but not that of the femoral muscle. Within 1 s after the onset of exercise, EMG activity in the pectoral muscle decreased by 74%. In both series of experiments, shivering was not induced in the femoral muscle. The level of pectoral muscle EMG activity stimulated by spinal cord cooling during exercise in the first series of experiments corresponded to the level to which EMG activity was reduced by exercise during spinal cord cooling in the second series of experiments (192% and 186% in relation to the post-cooling level, respectively). It is concluded that shivering can be induced in the pectoral muscle by spinal cord cooling during exercise in the pigeon.(ABSTRACT TRUNCATED AT 250 WORDS)

Windings' deformation is one of the most common transformer faults. The paper proposes a new method of Vibration frequency response analysis (VFRA) in order to effectively detect the deformation. A series of experiments have been conducted on a large power transformer to validate its efficiency by testifying its repetitiveness and sensitivity. The first series of experiments used VFRA on phase A under the same status in different time. VFRA was used in the second series of experiments on phase C with purposely removing its insulation pressboard. The third used VFRA to test phase C with manmade radial deformation. All the first series of experimental results are nearly the same, which shows the good repetitiveness for this method. The second and third results with the artificial faults were compared with those in normal status, which shows that VFRA can effectively detect the windings' deformation. Compared with short-circuit reactance measurement, VFRA is more sensitive.

The oxidation kinetics of nitrite to nitrate ions by potassium ferrate(VI) in a wide range of pH, from neutral to alkaline medium has been studied. Two series of kinetic experiments based on the different technologies for obtaining potassium ferrate(VI) were conducted. In the first series of experiments, crystalline potassium ferrate(VI) was prepared by the chemical synthesis. In the pH range 6.5–11, solid K 2 FeO 4 was added to solutions of nitrite ions at known concentration and pH. Kinetic studies were performed under pH and ionic strength controlled conditions. Half times for these experiments ranged from milliseconds to a few minutes. In the second series of experiments, solutions of K 2 FeO 4 were generated by the electrochemical synthesis. Alkaline solutions of potassium ferrate(VI) in 8.0 M KOH were obtained at t=20 o C by electrochemical dissolution of steel plates (S=10 cm 2 ) containing: C – 0.16 %; Mn – 0.43 %; Si – 0.04 %; S – 0.03 %; P – 0.04 %; the rest is Fe. The experiments were performed with fresh solutions of potassium ferrate(VI) and solutions, aged after the synthesis for several days. Kinetic studies were performed under nitrite concentrations controlled conditions. Half times in this case were in the range of several minutes to hours. It is found out that the maximum reaction rate is achieved by aging solution K 2 FeO 4 after the synthesis for 8 days. Both methods show that the oxidation rate is controlled by the concentration of protonated ferrate, . The dependence of the observed rate constants on pH, nitrite concentrations and ionic strength has been investigated. The true rate constants of reaction are found. Particular orders of the reaction by nitrite and ferrate ions and the overall order of the reaction are calculated. The oxidation rate constant of water by Fe(VI) is found. The studies presented in this paper are important because the oxidation kinetics of harmful inorganic and organic substances by ferrates(VI) of alkali metals is widely used to determine the optimal parameters of technological processes for the purification of surface water, industrial wastewater and air.

In the present study, we reassessed whether angiotensin (Ang)-(1-7) can exert short- and long-term cardiovascular effects because there has been a resurgence of interest in this N-terminal heptapeptide fragment of Ang II. In particular, we studied 3 aspects relating to the reported cardiovascular effects of Ang-(1-7): does this peptide (1) potentiate the hypotensive effect of bradykinin in normotensive Wistar-Kyoto rats and spontaneously hypertensive rats (SHR), (2) cause a depressor effect after long-term treatment in SHR, and (3) contribute to the antihypertensive effects of angiotensin-converting enzyme inhibitors? In the first series of experiments, Ang-(1-7) failed to enhance the dose-related hypotensive responses evoked by bradykinin in SHR (n=11) and Wistar-Kyoto (n=5) rats. In the second series of experiments, a 7-day intravenous infusion of Ang-(1-7) (24 microg x kg(-1) x h(-1)) decreased blood pressure in SHR (n=12) on days 4 and 5, although this effect waned despite continual Ang-(1-7) infusion. However, a new finding was that the Ang-(1-7) antagonist A-779 (24 microg x kg(-1) x h(-1) for 7 days) attenuated the depressor effect of Ang-(1-7) when given concurrently in a separate group of SHR (n=8). In the third series of novel experiments, the angiotensin-converting enzyme inhibitor perindopril was given in drinking water for 7 days (0.3 mg. kg(-1) x day(-1)), either alone (n=6) or combined with an intravenous infusion of A-779 (24 microg x kg(-1) x h(-1) for 7 days, n=8). Although this dose of A-779 attenuated the depressor effect of Ang-(1-7), it did not alter the antihypertensive effect caused by perindopril. Thus, the present results contrast with a number of previous studies and argue against Ang-(1-7) playing a major role in blood pressure regulation.

Single bit errors occur more frequently in memory elements. So for the avoidance of these single bit errors the Hamming code technique was recognized as the best among all other coding techniques. The most effective coding technique was Hamming [16, 11, 5] <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> which results in single error detection and correction as well as double adjacent error detection and correction. In this paper, a method to design SEC-DAEC codes with optimized decoding is presented and evaluated. Extended Hamming code is developed by adding an extra parity bit. The implementation is evaluated and compared by its application in an audio signal authentication in matlab with introduced errors The evaluations show there is a slight increase in area, power and delay of the decoder.

Soft errors in scientific computing applications are becoming inevitable with the ever-increasing system scale and execution time, and new technologies that feature increased transistor density and lower voltage. Soft errors can be mainly classified into two categories: bit-flipping error (e.g. 1 becomes −1) in random access memory; and computation error (e.g. 1+1 = 3) in floating point units. Traditionally, bit-flipping error is handled by the Error Correcting Code (ECC) technique, and computation error is dealt with the Triple Modular Redundancy (TMR) method. Note that, ECC cannot handle computation error, while TMR cannot deal with bit-flipping error and is not efficient on handling computation error. To uniformly and efficiently handle both computation and bit-flipping errors in matrix operations, the Algorithm-Based Fault Tolerance (ABFT) method is developed. This paper focuses on the detection of soft errors in the LU Decomposition with Partial Pivoting (LUPP) algorithm, which is widely used in scientific computing applications. First, this paper notes that existing ABFT methods are not adequate to detect soft errors in LUPP in terms of time or space. Then we propose a new ABFT algorithm which can detect soft errors in LUPP both flexible in time and comprehensive in space. Flexible in time means that soft errors can be detected flexibly during the execution instead of only at the end of LUPP, while comprehensive in space indicates that all of the elements in data matrices ( L and U) will be covered for detecting soft errors. To show the feasibility and efficiency of the proposed algorithm, this paper has incorporated it into the implementation of LUPP in the widely used benchmark High Performance Linpack (HPL). Experiment results verify the feasibility of this algorithm: for soft errors injected at various timings and to different elements in LUPP, this algorithm has detected most of the injected errors, which have covered all of the errors that cannot pass the residual check of HPL. Both theoretical overhead analysis and experiments demonstrate that this ABFT algorithm is also very efficient at detecting soft errors in LUPP.

Forgetting at short term: When do event-based interference and temporal factors have an effect?