Implementation and experimental performance evaluation of a hybrid interrupt-handling scheme

The performance of network hosts can be severely degraded when subjected to heavy traffic of today’s Gigabit networks. This degradation occurs as a result of the interrupt overhead associated with the high rate of packet arrivals. NAPI, a packet reception mechanism integrated into the latest version of Linux networking subsystem, was designed to improve Linux performance to suit today’s Gigabit traffic. NAPI is definitely a major step up from earlier reception mechanisms; however, NAPI has shortcomings and its performance can be further enhanced. A hybrid interrupt-handling scheme, which was recently proposed in Salah et al. [K. Salah, K. El-Badawi, F. Haidari, Performance Analysis and Comparison of Interrupt-Handling Schemes in Gigabit Networks, International Journal of Computer Communications, Elsevier, Amsterdam 30 (17) (2007) 3425–3441], can better improve the performance of Gigabit network hosts. The hybrid scheme switches between interrupt disabling–enabling (DE) and polling (NAPI). In this paper, we present and discuss major changes required to implement such a hybrid scheme in the latest version of Linux kernel 2.6.15. We prove experimentally that the hybrid scheme can significantly improve the performance of general-purpose network desktops or servers running network I/O-bound applications, when subjecting such network hosts to both light and heavy traffic load conditions. The performance is measured and analyzed in terms of throughput, packet loss, latency, and CPU availability.     

Ontology-based data mining approach implemented for sport marketing

Since sport marketing is a commercial activity, precise customer and marketing segmentation must be investigated frequently and it would help to know the sport market after a specific customer profile, segmentation, or pattern come with marketing activities has found. Such knowledge would not only help sport firms, but would also contribute to the broader field of sport customer behavior and marketing. This paper proposes using the Apriori algorithm of association rules, and clustering analysis based on an ontology-based data mining approach, for mining customer knowledge from the database. Knowledge extracted from data mining results is illustrated as knowledge patterns, rules, and maps in order to propose suggestions and solutions to the case firm, Taiwan Adidas, for possible product promotion and sport marketing.     

Electrochemical growth of tin(II) oxide films: Application in photocatalytic degradation of methylene blue

We have investigated the semiconducting and photoelectrochemical properties of SnO films grown potentiostatically on tin substrate. The oxide is characterized by X-ray diffraction, scanning electron microscopy and Raman spectroscopy. The anodic process corresponds to the formation of SnO·nH₂O pre-passive layer that is removed upon increasing potential due to surface etching at the metal/oxide interface. SnO films deposited for long durations (>50 mn) are uniform and well adhered; they thicken up to ~50 nm by diffusion-controlled process and the growth follows a direct logarithmic law. The thickness is determined by coulometry and the X-ray diffraction indicates the tetragonal SnO phase (SG: P4/mmm) with a crystallite size of 32 nm. The Mott–Schottky plot is characteristic of n type conductivity with an electrons density of 5.72×10¹⁸ cm⁻³, a flat band potential of −0.09 V_SCE and a depletion width of ~10 nm. The valence band, located at 5.91 eV below, vacuum is made up of hybridized O²⁻:2p Sn²⁺:5s while the conduction band (4.45 eV) derives from Sn²⁺:5p orbital. The electrochemical impedance spectroscopy (EIS) measured in the range (10⁻²–10⁵ Hz) shows the contribution of the bulk and grain boundaries. The energy band diagram predicts the photodegradation of methylene blue on SnO films. 67% of the initial concentration (10 mg L⁻¹) disappears after 3 h of exposure to visible light (9 mW cm⁻²) with a quantum yield of 0.072.     

A reliable and sensitive time-resolved fluorescent immunochromatographic assay (TRFICA) for ochratoxin A in agro-products

Immunochromatographic assays (ICAs) are considered as a suitable diagnostic tool for the detection of mycotoxins. Mycotoxins and especially, ochratoxin A are analytes with more demanding sensitivity requirements. To enhance the sensitivity of current immunochromatographic assays for ochratoxin A (OTA), a novel sensitive ICA was developed in this study. In the assay, microspheres enclosing fluorescent europium (III) [Eu(III)] nanoparticles (EuNPs) were used as a label for OTA monoclonal antibody (OTA-mAb) conjugation. Accordingly, assay was called time-resolved fluorescent immunochromatographic assay (TRFICA). The test strip was composed of three parts: a sample pad, nitrocellulose membrane and an absorbent pad. As for detection, a proper concentration of conjugated microspheres was pipetted into the microtube and sample extract was added to it. Then the strip was inserted into the tube and the fluid flow along the strip. The TRFICA results were obtained in 8 min and read by a portable TRFICA strip reader. The established method allows quantitative determination of OTA with limit of detection as low as 1.0 μg kg⁻¹ in the samples. For validation, spiked samples including wheat, maize, soybean and rice were respectively assayed by TRFICA and a standard high performance liquid chromatography equipped with a fluorescence detector (HPLC-FLD), and good agreement of results was obtained between two methods.     

Comparing the efficiency of chitosan with chlorine for reducing Vibrio parahaemolyticus in shrimp

Thailand is one of the leading exporters of frozen shrimp to many countries. Chlorine is the decontaminating agent most frequently used in the frozen shrimp industries to kill potential pathogens. However, long time contact to chlorine causes severe respiratory tract damage. In this study, chitosan was compared to chlorine for reducing Vibrio parahaemolyticus. In vitro investigation, chitosan could reduce more than 90% of V. parahaemolyticus, whereas chlorine completely eliminated this organism. In artificially inoculated shrimp, more than 90% reduction of V. parahaemolyticus was achieved by chitosan. A similar reduction was obtained by chlorine, however, at lower concentrations and less contact time. In naturally contaminated shrimp, neither agent completely eradicated V. parahaemolyticus, however, chitosan achieved a decrease of more than 60%. These results demonstrate the possibility of using chitosan to decontaminate pathogenic bacteria in the seafood factory, a change that would diminish health problems of the workers.     

亚麻籽油中药软胶囊的30天大鼠喂养试验研究

通过亚麻籽油与中药天然产物复配得到了一种具有缓解视疲劳作用的软胶囊。为了评价该软胶囊的安全性,对该样品进行30d大鼠喂养试验。试验结果显示,各试验组大鼠体重、进食量、食物利用率、血常规、脏体比及病理组织学观察等各项指标与阴性对照均无显著性差异。因此亚麻籽油中药软胶囊属无毒级,可开发成为高附加值保健食品。     

亚麻籽油中药软胶囊的急性毒性试验和遗传毒性试验研究

通过亚麻籽油与中药天然产物复配得到了一种具有缓解视疲劳作用的软胶囊,并对该样品进行了急性毒性试验和遗传毒性试验研究。结果表明,急性毒性试验中,最大灌胃剂量高达17.3g/kgBW;Ames试验、小鼠骨髓细胞微核试验和精子畸形试验结果均为阴性。因此,亚麻籽油中药软胶囊属无毒级,无致突变作用。     

Hydrodynamic and mass transfer study in a rectangular three-phase air-lift loop reactor

This study concerns a three-phase rectangular air-lift reactor. The first part deals with the reactor’s gas–liquid two-phase flow hydrodynamics. Parameters, such as the gas hold-up, the liquid velocity, the mixing parameters, and the solid hold-up, were quantified in the presence of two different plastic solids—a regular shape solid called P1, and an heterogeneous shape solid, P4. No fundamental influence of the solids on the studied parameters was noticed, except for the gas hold-up. Indeed, a bubble coalescence phenomenon was highlighted for high solid concentrations (ε_s > 16%). Moreover, a comparison of these two materials led to the conclusion that P4 exhibited better hydrodynamic performances. In a second set of experiments, the oxygen mass transfer was characterised in three-phase flow, with both kinds of plastic materials. The k_La coefficient was deduced from a mass balance on the gas phase. It was found to be weakly influenced by the presence, the nature or the quantity of solid.