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3-monochloropropane-1,2-diol (3-MCPD) is known as one of the neo-formed contaminants widely distributed in foodstuffs, especially in processed foods with high sides effects for human health. In this study, 3-monochloropropane-1,2-diol (3-MCPD) content for eleven (11) different types of foods from local market were evaluated in two ways using: (1) cysteine modified AgNPs (Cys-AgNPs) as functional nanomaterials for UV-Vis technique, and (2) gold-modified by Cys-AgNPs (Cys-AgNPs/Au) in electrochemistry sensor. High concentrations of 3-MCPD were found in most studied samples namely in liquid foods (palm oil and frying oil from tuna fish), fried foods (fried ripe banana, roasted peanut, banana chips, fried tuna and potato fries), smoked mackerel and roasted foods (pork barbecue). The maximum 3-MCPD content were 1085 μg/kg in liquid foods, 582 μg/kg in fried foods, 156 μg/kg in smoked and 716 μg/kg in roasted foods. As exhibited, the level of 3-MCPD in food products on the Ivorian market is relatively higher. This study indicates the importance of monitoring 3-MCPD content in food products for both domestic and industrial processing.

A heating phenomenon exists in the service process of magneto-rheological devices. For magnetorheological devices using magnetorheological grease (MRG) as the working medium, changes in the medium’s rheological behaviors caused by temperature increase will generate challenges in the reliable service of the devices. With laboratory-prepared MRG as the research object, MRG rheological property laws under different temperatures and magnetic field intensities are investigated, and the magnetic properties of carbonyl iron (CI) powder under different temperatures are analyzed. The relationship between the evolution of the MRG structural system and changes in rheological properties under the action of thermomagnetic coupling is discussed. The results show that the MRG structural system is composed of base carrier liquid soap fibers and magnetic chains under the action of a magnetic field, and the soap fibers can strengthen the structural intensity of the MRG. A decrease in the entanglement degree of the soap fiber structure caused by temperature increase will obviously weaken the intensity of the entire MRG system and narrow the regulation and control scope of the MRG rheological properties. The structural evolution of soap fibers under thermomagnetic coupling will affect the chain formation of magnetic particles and ultimately their rheological properties. At low temperature and magnetic field intensity, the entanglement degree of soap fibers is relatively high, and the magnetic force on magnetic particles is weak, which cannot completely overcome the binding of soap fibers. The influence of soap fibers is the dominant factor affecting the MRG rheological properties. As temperature and magnetic field intensity increase, the entanglement degree of soap fibers decreases, magnetic particles gradually disperse from the soap fibers under the action of a large magnetic field force, and the magnetic chain structure gradually becomes the dominant factor affecting the MRG rheological properties. Moreover, the weakening degree of the temperature increase effect on the MRG rheological properties decreases, and the rheological law changes gradually.

Additional file 1: Table S1. Detection parameters of eugenol for mass spectrometer. Table S2. Recovery, accuracy and precision of eugenol in feed samples (n = 6). Fig. S1. Chromatograms of eugenol in spiked fish feed sample (2 μg/kg).

In order to improve the joint performances by controlling the thermal effect of tool shoulder, a non-shoulder-plunge (NSP) welding tool is utilized to conduct friction stir welding (FSW) of an Al-Mg aluminum alloy in this paper. Sound FSW joint is successfully produced by using the NSP welding tool. In contrast to conventional FSW (C-FSW), the thermal effect of tool shoulder is effectively reduced by NSP-FSW, leading to a significant size reduction of shoulder-affected zone in the joint. Besides, the NSP-FSW joint shows finer grain structures in the stir zone and thermo-mechanically affected zone, and exhibits lower extents of grain coarsening, dislocation polygonization, and particle dissolution in the heat-affected zone. Hardness maps show that the softening region width of NSP-FSW joint is only nearly half that of C-FSW joint and the NSP-FSW joint exhibits higher hardness in the heat-affected zone than C-FSW joint. The tensile test results indicate that the joint efficiency is improved from 89 % of C-FSW joint to 97 % by the NSP-FSW process.

The weld thinning phenomenon occurring in conventional friction stir welding (C-FSW) has negative effects on the formation quality and serviceable reliability of FSW joints. The existing methods for solving the weld thinning problem in FSW exhibit some universal deficiencies, such as low efficiency, low quality and narrow applicable range. Motivated by this challenge, a novel non-weld-thinning (NWT) FSW process, during which a zero shoulder plunge depth is applied to the welding tool, is proposed and investigated in the present paper. The results indicate that the high quality NWT-FSW joints can be efficiently produced by using this novel process. Microstructural analysis implies that the grains in weld nugget of NWT-FSW joints present smaller size and a more uniformly distributed feature than those of C-FSW joints. Compared with the C-FSW joints, the NWT-FSW joints are characterized by narrower softening regions and higher minimum hardness values, leading to an increase in tensile strength during tensile test. The temperature history analysis suggests that the thermal effect of tool shoulder is effectively controlled during NWT-FSW due to the application of zero shoulder plunge depth, which is the intrinsic reason for the grain refinement and strength improvement of NWT-FSW joints. Keywords: Non-weld-thinning friction stir welding, Aluminum alloy, Microstructure characteristic, Mechanical property

Lubricating grease has increased thermorheological properties during heating, which may affect the lubrication of the friction pair. And a friction pair usually heats up in the working process. This study explored the effect of surface temperature of the friction pair on the lubrication performance under lubrication conditions. The thermorheological properties of lubricating grease were analyzed using a rotational rheometer, and the variations and mechanisms of the thermo- rheological properties were explored. The friction-wear test on lubrication was conducted at different temperatures to examine the effects of thermorheological properties on the tribological behaviors of lubricating grease. Wear scar morphology, composition change, and friction-lubrication mechanisms at different temperatures were probed through SEM and X-ray spectrometer analysis. The results showed that lubricating grease has significant thermorheological properties. Moreover, its soap fiber entanglement decreases with rising temperature, and the entanglement properties are slowly lost at high temperature. The soap fiber structure of lubricating grease plays a vital role in lubrication. As temperature rises, the soap fiber entanglement of lubricating grease decreases and the base oil is more easily released under shear, exhibiting a trend of friction coefficient decreasing with the rising temperature. High temperatures weaken the soap fiber entanglement of lubricating grease, the film-forming property, and the surface friction-abrasion resistance of the friction pair and even cause oxidative wear.

2A14-T6 aluminum alloy was bobbin tool friction stir welded (BT-FSW) at various welding speeds. The microstructural analysis indicates that in the weld nugget the grains of the upper layer are smaller than those of the lower layer, which should be attributed to the larger extent of heat dissipation through the top shoulder. An ellipse-shaped region and a triangle-shaped region characterized by large elongated grain structures are found in the middle layer of the weld nugget of BT-FSW joints. The insufficient material plastic deformation caused by the flat feature of tool pin is believed to be the reason for the formation of the both regions. The insufficiently stirred regions can significantly affect the fracture features of joints during tensile test. At low welding speeds, the joints are all fractured along the border of the ellipse-shaped region. While at high welding speeds, the fracture path is just through the triangle-shaped region. With increasing welding speed, the joint strength is firstly increased to a peak and then shows a sharp decrease due to the occurrence of void defects. A maximum strength efficiency of 75% is achieved in this study. (C) 2014 Elsevier Ltd. All rights reserved.

Concurrency control has always been one of the most important issues in the design of synchronous groupware systems with fully-replicated architecture. An ideal strategy should be able to support natural and flexible human-to-computer and human-to-human interactions while maintaining the consistency of the system. This paper summarizes previous researches on this topic and points out the deficiencies of the existing results. A novel semantics-based concurrency control framework,oodOPT, is proposed. The main idea of the framework is to resolve conflicts by utilizing semantics of the operations and the accessed data objects. With this approach, complexities in concurrency control are shifted completely from application developers to the framework. Conflicts among operations on objects with different semantics and the strategies resolving these conflicts are analyzed. After describing the algorithm in full detail, the discussion ends up with a comparison with other related work and some considerations for open problems.

Friction stir lap welding of 7B04 aluminum alloy was conducted in the present paper, and the effect of welding speed on the defect features and mechanical performance of lap joints was investigated. The results indicate that the hook defect at the advancing side (AS) can reduce the effective thickness of the top sheet, and the sheet thinning level is gradually lowered by increasing the welding speed. The cold lap defect at the retreating side (RS) can result in effective thickness reduction in both top and bottom sheets, and the total height of the cold lap defect varies slightly with the welding speed. The tensile properties of the lap joints are largely related to the sheet thinning levels caused by the defects. The fracture strength of AS-loaded lap joints is progressively increased with increasing welding speed, while that of RS-loaded lap joints evolves slightly with welding speed. It is found that the affecting characteristic of loading configuration on the joint performance is also dependent on the welding speed. At lower welding speeds, the AS-loaded lap joints show lower fracture strength than the RS-loaded lap joints. When the welding speed is high, the AS-loaded lap joints present superior tensile properties to RS-loaded lap joints.

As research and development on CSCW advance rapidly, there is an increasing need for a general purpose platform based on which various types of CSCW applications can be developed. The platform should provide not only necessary services that minimize development efforts, but also sufficient flexibility for the construction of applications. This paper describes DICSE, a platform providing data management services based on the characteristics of data flow in CSCW systems, detailing its underlying cooperative work model, the services, the architecture and some considerations for the implementation.

Workflow management systems can help business goals to be achieved with high efficiency by means of sequencing work activities and invoking appropriate human and/or information resources associated with these activities. As computer networks are used more and more widely in daily work, workflow management attracts more and more attention from both industry and research communities. This paper summarizes the state of art in WfMS research, detailing some workflow-related concepts and its typologies, the WfMS reference model proposed by WfMC, and some of the current research trends and hotspots.

Workflow management systems provide an ideal environment and a set of tools for enterprise-wide cooperation by automating business processes. An intelligent workflow management system should have the ability to analyze and re-engineer workflow process to improve performance and efficiency. There are two possible ways to do this: technology-based re-engineering and re-engineering based on relations between people or organizations. The latter forms the basic topics of business process re-engineering (BPR). This paper discusses workflow process re-engineering (WPR), which focuses on static analyzing of data flow and control flow of workflow definitions for process optimizing, so that system performance and cooperation efficiency can be improved while original intentions and executing results of the optimized process remain unchanged.

As the Internet/intranet/WWW technologies become more and more mature and Web-based applications become richer and richer, we are provided with an ideal computing environment to construct workflow management systems (WfMSs). Web-based WfMSs can help business goals to be achieved effectively by means of integrating various distributed resources and applications and coordinating work activities in an easy to access environment. This paper describes a Web-based general purpose workflow management system named Wowww!, detailing its architecture, the workflow engine, the workflow model and the algorithms used for workflow instance execution. Other features and some considerations for future work are also discussed.