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This paper presents a comprehensive review of high-level control techniques for upper-limb robotic training. It aims to compare and discuss the potentials of these different control algorithms, and specify future research direction. Included studies mainly come from selected papers in four review articles. To make selected studies complete and comprehensive, especially some recently-developed upper-limb robotic devices, a search was further conducted in IEEE Xplore, Google Scholar, Scopus and Web of Science using keywords ('upper limb*' or 'upper body*') and ('rehabilitation*' or 'treatment*') and ('robot*' or 'device*' or 'exoskeleton*'). The search is limited to English-language articles published between January 2013 and December 2017. Valuable references in related publications were also screened. Comparative analysis shows that high-level interaction control strategies can be implemented in a range of methods, mainly including impedance/admittance based strategies, adaptive control techniques, and physiological signal control. Even though the potentials of existing interactive control strategies have been demonstrated, it is hard to identify the one leading to maximum encouragement from human users. However, it is reasonable to suggest that future studies should combine different control strategies to be application specific, and deliver appropriate robotic assistance based on physical disability levels of human users. [ABSTRACT FROM AUTHOR]

This article explores wide-ranging potential of the wearable ankle robot for in-house rehabilitation. The presented robot has been conceptualized following a brief analysis of the existing technologies, systems, and solutions for in-house physical ankle rehabilitation. Configuration design analysis and component selection for ankle robot have been discussed as part of the conceptual design. The complexities of human robot interaction are closely encountered while maneuvering a rehabilitation robot. We present a fuzzy logic-based controller to perform the required robot-assisted ankle rehabilitation treatment. Designs of visual haptic interfaces have also been discussed, which will make the treatment interesting, and the subject will be motivated to exert more and regain lost functions rapidly. The complex nature of web-based communication between user and remotely sitting physiotherapy staffhasalsobeendiscussed.Ahigh-levelsoftware architecture appended with robot ensures user-friendly operations. This software is made up of three important components: patient-related database, graphical user interface (GUI), and a library of exercises creating virtual reality--specifically developed for ankle rehabilitation. [ABSTRACT FROM AUTHOR]

Direct coal liquefaction residue (DCLR) could be extracted using dipropylamine (DPA) to afford extract with polycyclic aromatic structures, and the separation of extract and DPA as well as the recovery of DPA could be achieved by the nonthermal CO2-trigger at room temperature and atmosphere pressure, which would potentially gain huge energy savings. On the basis of preliminary single factor experiment, response surface methodology was used for optimizing DCLR extraction, and Box–Behnken experimental design was adopted, where extraction time, extraction temperature, and ratio of DPA to DCLR were chosen as the three independent variables, and extract yield was chosen as response variable. Among the three independent variables, DCLR extraction was mainly affected by extraction time and ratio of DPA to DCLR, and the two variables exhibited an interaction effect on the extract yield. The predicted extract yield would reach the peak under the optimized conditions, i.e., extraction time of 48 min, extraction temperature of 25°C, and DPA to DCLR ratio of 39 mL/g. In the practical experiment under the optimal conditions, the real extract yield was up to 29.42%, which was similar to the expected one. Response surface methodology proved to be applicable and useful for optimization of DCLR extraction. [ABSTRACT FROM PUBLISHER]

Ankle rehabilitation robots can play an important role in improving outcomes of the rehabilitation treatment by assisting therapists and patients in number of ways. Consequently, few robot designs have been proposed by researchers which fall under either of the two categories, namely, wearable robots or platform-based robots. This paper presents a review of both kinds of ankle robots along with a brief analysis of their design, actuation and control approaches. While reviewing these designs it was observed that most of them are undesirably inspired by industrial robot designs. Taking note of the design concerns of current ankle robots, few improvements in the ankle robot designs have also been suggested. Conventional position control or force control approaches, being used in the existing ankle robots, have been reviewed. Apparently, opportunities of improvement also exist in the actuation as well as control of ankle robots. Subsequently, a discussion on most recent research in the development of novel actuators and advanced controllers based on appropriate physical and cognitive human-robot interaction has also been included in this review. [ABSTRACT FROM AUTHOR]

The effect of small molecular compounds in coal on quick direct coal liquefaction at high temperature was studied. The results showed that extraction with tetrahydrofuran just removed a portion of organic compounds, which were free or embedded in the macromolecular network structure in coal, without changing the macromolecular network of coal. However, removal of small molecular compounds in coal influenced the pyrolysis behavior and liquefaction performance of coal. The extracted coal exhibited better liquefaction activity in good donor solvent. The liquefaction conversion and yield of oils were higher than that of raw coal. The reason was that extraction with tetrahydrofuran made the relaxation of coal macromolecular network, and increased average pore size of extracted coal, which favored the diffusion of hydrogen-donating solvent into coal macromolecular network, thus increased the probability of collision of radicals and active hydrogen. The quick liquefaction experiment of extracted coal in poor hydrogen-donating solvents showed that the small molecular compounds played an important role as hydrogen donor during the quick liquefaction at high temperature without external active hydrogen resource. [ABSTRACT FROM PUBLISHER]

The authors present a case study of using semi-quantitative oil fingerprinting technology to correctly back allocate production of individual sand layer in commingled well. A large number of oil samples were collected over time and analyzed by gas chromatography (GC) for their oil fingerprints. The results showed that the production allocation of single layer in two-layer commingled well and the hydrocarbon concentrations of commingled oil were in a liner relationship. However, the production allocation of single layer and oil GC fingerprint parameters were in curvilinear relationship. The semi-quantitative oil fingerprinting technology was suitable for the case of two-layer commingled well, and three-layer commingled well with larger gas chromatography differences among oil of each layer. [ABSTRACT FROM PUBLISHER]

Tannin extract desulfurization technology is widely applied in China, however, in which there are sulfur-containing byproducts that can cause negative effects, such as reducing desulfurization efficiency and increasing operating cost etc. Thus, inhibiting side reactions and controlling byproducts is an important problem to be resolved. In this article, the cause of byproducts formation by thermodynamic analysis is reported. First, the reaction mechanism between HS−and pentavalent vanadium V(V) in desulfurization solution is researched, and it is conclude that HS−can transforms instantly into polysulfide ionsSx2−, thenSx2−forms the element sulfur. Thus,Sx2−is the main source to generate byproducts. Second, by calculating and comparing the Gibbs free energy change of side reactions, the results show thatSx2−is more active than HS−in solution and can react more easily with oxygen to produce byproducts. Therefore, quickening the transformation fromSx2−to element sulfur is a key measure to resolve the problem on side reaction. [ABSTRACT FROM PUBLISHER]

There has been a considerable number of recent discussions on applications of different types of dynamic derivatives. The dynamic derivatives not only play a central role in time scales theory and methods, but also provide a remarkable way of approximations in mathematical modelling and computational applications. In this paper, we will explore connections between existing dynamic and conventional derivatives over the time scales used. We will show that while first order dynamic derivatives provide acceptable accuracies in approximating conventional derivatives, second order dynamic derivatives are in general inconsistent with conventional derivatives. It is evident that, before incorporating structures of particular time scales used into the dynamic derivative formulae properly, one needs to be prudential when bridging discrepancies between the differential and difference equations modelling similar applications by higher order dynamic derivatives. Numerical experiments are given to further illustrate our conclusions. [ABSTRACT FROM AUTHOR]