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Assessment is critical during the procedure of stroke rehabilitation. However, traditional assessment methods are time-consuming, laborious, and dependent on the skillfulness of the therapist. Moreover, they cannot distinguish whether the improvement comes from the abnormal compensation or the improvement of upper extremity motor function. To make up for the shortcomings of the traditional methods, this study proposes a novel assessment system, which consisted of a rehabilitation robot and motion capture (MoCAP) system. A 9-degree-of-freedom (DOF) kinematic model is established, which consists of the shoulder girdle, shoulder, elbow, and wrist joints. And seven assessment indices are selected for this assessment system, including a range of motion (ROM), shoulder girdle compensation (SGC), trunk compensation (TC), aiming angle (AA), motion error (ME), motion length ratio (MLR), and useful force (UF). For AA, ME, and MLR, all describe the motor ability of the upper extremity, and a linear model was proposed to map these three indices into one index, called motor control ability (MCA). Then, this system can quantitatively evaluate human upper extremity motor function from joint space kinematics, Cartesian space kinematics, and dynamics. Three healthy participants were invited to verify the effectiveness of this system. The preliminary results show that all participants’ handedness performs a little better than the nonhandedness. And the performance of the participants and the change of all the upper limb joints can be directly watched from the trajectory of the hand and joint angles’ curve. Therefore, this assessment system can evaluate the human upper limb motor function well. Future studies are planned to recruit elderly volunteers or stroke patients to further verify the effectiveness of this system.

BACKGROUND: With the population aging, post-stroke patients suffering from hemiplegia are also rapidly increasing. It is essential to provide valid rehabilitation methods for hemiplegia patients. Mirror therapy is an effective rehabilitation method and is widely applied in many rehabilitation robots. OBJECTIVE: The aim of this paper is to present a path planning method to guarantee the robot’s motion performance during mirror therapy. METHODS: The kinematic framework of the proposed rehabilitation system is detailed, then the reference motion path of the manipulator is calculated according to kinematic transformation. The concept of manipulability is introduced to describe the motion performance of the manipulator. Based on the above work, a path planning method based on A* algorithm is proposed to quantitatively analyze and optimize the motion performance of the manipulator. RESULTS: Preliminary experiments with the proposed rehabilitation system are conducted to verify the proposed path planning method. The characteristics of the proposed method are analyzed through two typical situations. The results showed that the proposed method can build a new path for manipulator, which can ensure the robot’s motion performance and is highly consistent with the reference path. CONCLUSION: The results showed that the manipulator could achieve the task with acceptable error, which indicates the potential of the proposed path planning method for mirror therapy.

BACKGROUND: The definition of rehabilitation training trajectory is of great significance during rehabilitation training, and the dexterity of human-robot interaction motion provides a basis for selecting the trajectory of interaction motion. OBJECTIVE: Aimed at the kinematic dexterity of human-robot interaction, a velocity manipulability ellipsoid intersection volume (VMEIV) index is proposed for analysis, and the dexterity distribution cloud map is obtained with the human-robot cooperation space. METHOD: Firstly, the motion constraint equation of human-robot interaction is established, and the Jacobian matrix is obtained based on the speed of connecting rod. Then, the Monte Carlo method and the cell body segmentation method are used to obtain the collaborative space of human-robot interaction, and the VMEIV of human-robot interaction is solved in the cooperation space. Finally, taking the upper limb rehabilitation robot as the research object, the dexterity analysis of human-robot interaction is carried out by using the index of the approximate volume of the VMEIV. RESULTS: The results of the simulation and experiment have a certain consistency, which indicates that the VMEIV index is effective as an index of human-robot interaction kinematic dexterity. CONCLUSIONS: The VMEIV index can measure the kinematic dexterity of human-robot interaction, and provide a reference for the training trajectory selection of rehabilitation robot.

This study proposed and tested a theoretical model for specifying the structural relationship between personality characteristics (including core self-evaluation, social comparison, philosophies of...

Purpose This study explored the mediating effect of career calling in the relationship between family-supportive supervisor behaviors and turnover intention among nurses. Methods Data were gathered from 563 nurses enrolled in eight public hospitals in China. They were required to complete measures of family-supportive supervisor behaviors, career calling, and turnover intention. Hierarchical multiple regression analysis and the bootstrapping procedure were used to examine the mediating role of career calling. Results Family-supportive supervisor behaviors were positively associated with career calling, but negatively associated with turnover intention. Furthermore, career calling partially mediated the relationship between family-supportive supervisor behaviors and turnover intention. Conclusion This study provides strong evidence for an increasing body of work that emphasizes the importance of nursing leaders engaging in family-supportive behaviors for increasing employee career calling and reducing turnover intention.

This study examined meaningful work and vocational identity influences on the relationship between perceived family supportive supervisor behaviour (FSSB) and career satisfaction among educators. P...

This study aimed to examine the extent to which career calling mediates the relationship between ethical leadership and organisational commitment. The sample consisted of 943 employees randomly rec...

Deoxynivalenol (DON) and fumonisin B

Droplet dynamics and condensation phenomena are widespread in nature and industrial applications, and the fundamentals of various technological applications. Currently, with the rapid development of interfacial materials, microfluidics, micro/nano fabrication technology, as well as the intersection of fluid mechanics, interfacial mechanics, heat and mass transfer, thermodynamics and reaction kinetics and other disciplines, the preparation and design of various novel functional surfaces have contributed to the local modulation of droplets (including nucleation, jumping and directional migration) and the improvement of condensation heat transfer, further deepening the understanding of relevant mechanisms. The wetting and dynamic characteristics of droplets involve complex solid-liquid interfacial interactions, so that the local modulation of microdroplets and the extension of enhanced condensation heat transfer by means of complex micro/nano structures and hydrophilic/hydrophobic properties is one of the current hot topics in heat and mass transfer research. This work presents a detailed review of several scientific issues related to the droplet dynamics and dropwise condensation heat transfer under the influence of multiple factors (including fluid property, surface structure, wettability, temperature external field, etc.). Firstly, the basic theory of droplet wetting on the solid wall is introduced, and the mechanism of solid-liquid interfacial interaction involving droplet jumping and directional migration on the functional surfaces under the various influencing factors is discussed. Optimizing the surface structure for the local modulation of droplets is of guidance for condensation heat transfer. Secondly, we summarize the existing theoretical models of dropwise condensation applicable to various functional surfaces and briefly outline the current numerical models for simulating dropwise condensation at different scales, as well as the fabricating techniques of coatings and functional surfaces for enhancing heat transfer. Finally, the relevant problems and challenges are summarized and future research is discussed.

Clinical studies have demonstrated that robot-involved therapy can effectively improve the rehabilitation training effect of motor ability and daily behavior ability of subjects with an upper limb motor dysfunction. This paper presents an impedance-based assist-as-needed controller that can be used in robot-aided rehabilitation training for subjects with an upper extremity dysfunction. Then, the controller is implemented on an end-effector upper extremity rehabilitation robot which could assist subjects in performing training with a spatial trajectory. The proposed controller enables subjects&rsquo, arms to have motion freedom by building a fault-tolerant region around the rehabilitation trajectory. Subjects could move their upper limb without any assistance within the fault-tolerant region while the robot would provide assistance according to the subjects&rsquo, functional ability when deviating from the fault-tolerant region. Besides, we also put forward the stiffness field around the fault-tolerant region to increase the robot&rsquo, s assistance when subjects&rsquo, hand is moving outside the fault-tolerant region. A series of columnar rigid walls would be constructed in the controller according to the subjects&rsquo, functional ability, and the stiffness of the wall increases as the motion performance deteriorates. Furthermore, the controller contains five adjustable parameters. The controller would show different performances by adjusting these parameters and satisfy the requirement of robot-aided rehabilitation training at different rehabilitation stages such as passive, assistant, active, and resistant training. Finally, the controller was tested with an elderly female participant with different controller parameters, and experimental results verified the correctness of the controller and its potential ability to satisfy the training requirements at different rehabilitation stages. In the close future, the proposed controller in this work is planned to be applied on more subjects and also patients who have upper limb motor dysfunctions to demonstrate performance of the controller with different parameters.

This study investigated the mediating and moderating effects of role ambiguity (RA) on the relationship between leader- member exchange (LMX) and organisational citizenship behaviour (OCB). Partici...

Mission reliability could systematically characterize the running state of a manufacturing system and the rationality of production task setting in advance. However, few studies can realize the mission reliability modeling, which integrates production scheduling based on fully considering the complexity, dynamics, and multi-state characteristics of a manufacturing system. Thus, a dynamic method for modeling the mission reliability of a multi-state manufacturing system with multiple production lines is proposed in this paper. First, the multi-state characteristic of manufacturing systems operation is analyzed. On this basis, considering the composition of manufacturing systems, the connotation and modeling mechanism of the mission reliability of manufacturing systems are proposed. Second, combining the discretization of machine performance states and dynamic continuity of the performance degradation process, the dynamic modeling method of multi-state machine performance and buffer usage are respectively discussed. The transfer evolution of task demands in the production line is analyzed, and the decomposition method of task scheduling and load mapping in multiple production lines is provided. Third, considering the characteristics of multiple production lines and the buffer of a manufacturing system, taking production tasks as the core and integrating production scheduling, a modeling method for the mission reliability of manufacturing systems is proposed. Finally, the effectiveness of the proposed approach is verified using a case study on the modeling of the mission reliability of a manufacturing system of aerospace parts.

A new type of three-dimensional pin–fin plate with elliptical cross-section was proposed. Condensation heat transfer of FC-72 in a narrow rectangular channel with the proposed pin fins was experimentally studied in normal gravity and microgravity. The effects of pin geometry, thermal conductivity, mass flow rate and gravity on condensation heat transfer were investigated. The visualization experiment under microgravity was carried out and the condensate behaviour was observed by high CCD camera. The results showed that all the elliptical pin-fin plates exhibited substantially better performance than the flat plate. The influence of pin geometry and thermal conductivity on condensation heat transfer coefficient was great. The smaller pin size and higher thermal conductivity were favourable for condensation enhancement. The average condensation heat transfer coefficient increased with the increase of mass flow rate. In microgravity, obvious fluctuations and climbs occurred in gas-liquid interface. However, the condensate behaviour on the condensing surface was unconspicuous. For unsteady state, the vapor-side temperature difference increased evidently in microgravity. Microgravity had a certain effect on temperature evolution of the condensing base. Short-term microgravity degraded the condensation heat transfer coefficient in quasi-steady state or unsteady state, but had little effect on pulsating state.

This study investigated whether and how empowering leadership influences employees’ career calling by exploring the mediating role of psychological need fulfilment. Participants comprised a conveni...

Leigang Zhang,1,2 Yuzhu Zhang1,3 1School of Psychology, Inner Mongolia Normal University, Hohhot, Inner Mongolia Autonomous Region, People’s Republic of China; 2School of Teacher Education, Shaoxing University, Shaoxing, Zhejiang Province, People’s Republic of China; 3Hohhot Vocational College, Hohhot, Inner Mongolia Autonomous Region, People’s Republic of ChinaCorrespondence: Yuzhu ZhangHohhot Vocational College, Provincial Highway 101, Saihan District, Hohhot, Inner Mongolia Autonomous Region, 010051, People’s Republic of ChinaEmail nsdzyz@163.comPurpose: Given that extensive studies have documented the wide-ranging benefits of living a calling, determining whether and how living a calling can be improved is of great importance. Although recent research implies that a growth mindset about work may link to self-regulatory processes and living a calling, little research to date has directly examined the relationships between these variables. Building on Burnette’s SOMA model, this study was designed to examine the premise that a growth mindset about work was a predictor of living a calling and to explore the mediating role of self-regulation in the growth mindset about work—living a calling link.Methods: This cross-sectional study was conducted among educational professionals in China. Data were collected from 608 primary and secondary school teachers on growth mindsets about work, self-regulation and living a calling. A structural equation model was used to test the hypothesis that self-regulation would mediate the relationship between a growth mindset about work and living a calling.Results: Consistent with our premise, a growth mindset about work was positively associated with living a calling. Also, a growth mindset about work was significantly associated with self-regulation strategies in terms of goal setting, perseverance, decision making, and learning from mistakes. As hypothesized, a growth mindset about work was related to higher levels of living a calling via goal setting, perseverance, and learning from mistakes.Conclusion: The findings contribute to the increasing breadth of the growth mindset literature across various contexts and its consequences for one’s living a calling, which expand the nomological web of correlates of growth mindset about work. Furthermore, these findings suggest that fostering a growth mindset about work may facilitate adaptive behaviors and, thereby, serve as a calling intervention.Keywords: growth mindset about work, self-regulation, living a calling, SOMA model

Soil amendment with biochar may trigger a series of positive and negative biological effects, partly because it interferes quorum sensing (QS) signals synthesized by microorganisms for communication. However, the mechanisms through which biochar interacts with these QS signals remain elusive. This study explored the mechanisms of interactions between N-acyl homoserine lactones (AHLs) and two maize straw-derived biochars (MBs) with different pyrolysis temperature. Pseudo-second-order equation model best depicted AHLs sorption kinetics on MBs. The intra-particle diffusion model revealed that AHLs sorption onto MBs consists of several stages. The sorption isotherms data of AHLs on MBs were in well agreement with both Langmuir and Freundlich models, indicating the occurrence of energetic distribution of active sites on the heterogeneous biochar with multilayer sorption. However, the AHLs sorption capacity on MBs varied, with biochar pyrolyzed at 600 °C displaying a higher AHLs sorption capacity compared with biochar pyrolyzed at 300 °C. It may be attributed to a variety of physiochemical interactions such as pore filling, functional groups complexation, hydrogen bond, and hydrophobic action. The adsorption/partitioning model results and thermodynamic parameters of Gibbs free energy (ΔG) confirmed that physical and chemical sorption occurred concurrently throughout the whole AHLs sorption process, with physical partitioning playing a greater role than surface sorption. The findings suggest that soil amendment with biochar may have a variety of effects on intra/inter-cellular communication, further implying biochar can be specially prepared to mediate soil processes related to microbial communication, like pollutant biodegradation, and carbon/nitrogen cycling.

In present study, a new type of three-dimensional pin–fin plate with elliptical cross-section was proposed. Steam condensation on the proposed plates with different geometric parameter was experimentally studied at atmospheric pressure. The effects of horizontal pin spacing, pin height and inclination angle on condensation heat transfer were investigated. The results showed that all the elliptical pin-fin plates exhibited substantially better performance than the flat plate. The highest enhancement ratio of 2.33 was achieved when the elliptical pin-fin plate was vertically placed. The geometric parameter and inclination angle showed a strong influence on the performance of elliptical pin-fin plate. The performance of elliptical pin-fin plate was enhanced when the pin height increased from 1.2 mm to 2.0 mm or the horizontal pin spacing increased from 1.2 mm to 2.0 mm. The strengthening effect of pin height became weaker with the increase of horizontal pin spacing. When the inclination angle increased from 0° to 60°, the heat flux and average condensation heat transfer coefficient decreased by 16 and 25%, respectively. With the increase of inclination angle, the gravity effect in the direction of condensate flow decreased, resulted in the deterioration of heat transfer. The results can provide reference for practical engineering applications and the further optimization design of pin-fin enhanced condensation structure.

The dry sliding wear behaviors of Mg based nanocomposites were investigated using the ball-on-disk wear tester. The friction coefficient of Mg nanocomposite reinforced with 15 vol% SiC nanoparticles is much higher than pure Mg and AZ31B alloy. Its wear resistance is about 23 times higher than that of pure Mg. Analysis on the surface and debris suggests that the delamination mechanism of Mg has been overcome by the addition of high volume fraction nanoparticles, and the dominant wear mechanism of the Mg-SiC nanocomposites is oxidation.

This paper studied the effect of ultrasound on distribution characteristics of condensate droplets on a vertical metal surface. The surface was made of aluminum and coated with PVC film to obtain durable condensate droplets. Visualization of the condensation process was carried out under the action of ultrasonic vibration with a constant frequency of 20 kHz. The effects of ultrasonic power on surface coverage of condensate droplets, first shedding time of condensate droplets, total number of shedding, heat flux and condensation heat transfer coefficient were analyzed. Furthermore, the mechanism of ultrasonic vibration on accelerating the shedding of condensate droplets was discussed. The results indicated that the shedding of condensate droplets was accelerated by ultrasound compared with those without ultrasound. In addition, the shedding period of condensate droplets was decreased with the increase of ultrasonic power. Contrarily, the heat flux and the condensation heat transfer coefficient were increased with the increase of ultrasonic power. The maximum enhancement ratio of heat transfer coefficient reached 2.67 compared with that without applying ultrasound. This study shows that ultrasound has a good application prospect in strengthening condensation heat transfer, particularly for space applications in microgravity environment.

Moment independent sensitivity index is widely concerned and used since it can reflect the influence of model input uncertainty on the entire distribution of model output instead of a specific moment. In this paper, a novel analytical expression to estimate the Borgonovo moment independent sensitivity index is derived by use of the Gaussian radial basis function and the Edgeworth expansion. Firstly, the analytical expressions of the unconditional and conditional first four-order moments are established by the training points and the widths of the Gaussian radial basis function. Secondly, the Edgeworth expansion is used to express the unconditional and conditional probability density functions of model output by the unconditional and conditional first four-order moments, respectively. Finally, the index can be readily computed by measuring the shifts between the obtained unconditional and conditional probability density functions of model output, where this process doesn't need any extra calls of model evaluation. The computational cost of the proposed method is independent of the dimensionality of model inputs and it only depends on the training points and the widths which are involved in the Gaussian radial basis function meta-model. Results of several case studies demonstrate the effectiveness of the proposed method.

Estimating the Probability Density Function (PDF) of the performance function is a direct way for structural reliability analysis, and the failure probability can be easily obtained by integration in the failure domain. However, efficiently estimating the PDF is still an urgent problem to be solved. The existing fractional moment based maximum entropy has provided a very advanced method for the PDF estimation, whereas the main shortcoming is that it limits the application of the reliability analysis method only to structures with independent inputs. While in fact, structures with correlated inputs always exist in engineering, thus this paper improves the maximum entropy method, and applies the Unscented Transformation (UT) technique to compute the fractional moments of the performance function for structures with correlations, which is a very efficient moment estimation method for models with any inputs. The proposed method can precisely estimate the probability distributions of performance functions for structures with correlations. Besides, the number of function evaluations of the proposed method in reliability analysis, which is determined by UT, is really small. Several examples are employed to illustrate the accuracy and advantages of the proposed method.

In response to the ever-increasing demand of community-based rehabilitation, a novel smart rehab walker iReGo is designed to facilitate the lower limb rehabilitation training based on motion intention recognition. The proposed walker provides a number of passive degrees-of-freedom (DoFs) to the pelvis that are used to smooth the hip rotations in such a way that the natural gait is not significantly affected, meanwhile, three actuated DoFs are actively controlled to assist patients with mobility disabilities. The walker first identifies the user’s motion intention from the interaction forces in both left and right sides of the pelvis and then uses the kinematic model to generate appropriate driving velocities to support the body weight and improve mobility. In this paper, workspace, dexterity, and the force field of the walker are analyzed based on the system Jacobian. Simulation and experiments with healthy subjects are carried out to verify the effectiveness and tip-over stability. These results demonstrate that the walker has sufficient workspace for pelvic motions, satisfactory dexterity, and near-linear force feedback within the prescribed workspace, and that the walker is easily controlled to ensure normal gait.

Discussed in this paper is the tip-over stability analysis of a pelvic support walking robot. To improve the activities of daily living (ADL) in hemiplegic patients, a pelvic support walking robot is proposed to help patients facilitating their rehabilitation. During the gait training with the robot, the abnormal man-machine interaction forces may lead to the tip-over of the robot, which is not beneficial to the rehabilitation process. A new method is proposed to predict the possibility of tipping over and evaluate the stability of the robot based on statics model, dynamics model, and zero-moment point (ZMP) theory. Through the interaction forces and moments analysis with static case, the safe point (ZMP) is studied, and the influence factors of force/moment are analyzed by dynamics case. An optimization algorithm based on the genetic algorithm (GA) is proposed to reduce the risk of tipping over. The simulation results show that the optimization algorithm can keep the robot from tipping over when the interaction forces exceed the safety threshold.

The inner collection between process reliability and stable process of space product is analyzed, and the model of controlling-detecting process parameters is built by multiple linear regression technology. Then the extremum and mean value of multivariable controlling parameters’ expected value, which meet the requirement of process detecting parameters’ stability, are used to predict each mean response and new response, and also prediction ellipsoid and joint confidence intervals of detecting parameters are obtained. Furthermore, three optimization problems based on genetic algorithm, which focused on controlling parameters’ fluctuation interval, are studied. Finally, taking the coating process of space product ferrite phase shifter as an example, the method is analyzed and verified. Therefore, the significant guarantee is provided for improving space products’ quality.

Heterogeneous Mg matrix nanocomposites (Hetero-Mg-NCs) with different sizes/morphologies of soft phase were fabricated by planetary ball milling and subsequent hot-pressing sintering. The Hetero-Mg-NCs were subjected to non-notched and notched bending tests to investigate their bending behaviors. The results showed that high bending strength was successfully attained in the Hetero-Mg-NCs, especially the one with large soft phase exhibited a simultaneous improvement of bending strength and fracture toughness by 50% and 57.7%, respectively, compared with those of pure Mg. The fractography measurements revealed that the Hetero-Mg-NCs failed by a mixed-mode fracture. The abundant interfacial delamination cracks and micro-dimples were found in the Hetero-Mg-NC with large soft phase, indicating the enhancement of fracture toughness. By examining the crack propagation path, it was revealed that the Hetero-Mg-NC with large soft phase showed a longer zigzagging path, owing to the more profound crack tunneling, deflection and bifurcation phenomena. The results demonstrated that Mg–NCs with heterogeneous structure can simultaneously attain high strength and fracture toughness under bending loading.

Global continental marginal basins are often segmented and significantly impact hydrocarbon accumulation. The northern South China Sea is a marginal sea, in which several passive continental marginal basins have been developed. It is represented by the Pearl River Mouth Basin in the eastern part and the Qiongdongnan Basin in the western part, with rich oil and gas resources that exhibit significant differences in hydrocarbon accumulation. However, the impacts on hydrocarbon accumulations due to various segmentations have rarely been discussed. Based on the systematic interpretation of seismic data, paleo-biological data, detailed thickness mappings, sedimentary facies mappings, analyses of organic geochemical characteristics of source rocks, reservoir formation characteristics, and hydrocarbon accumulation patterns, the tectonic segmentation and its effect on hydrocarbon accumulation in the two basins are discussed. The tectonic evolution in the northern part of the South China Sea was characterized earlier in east segmented and later in west segmented; this same pattern is always displayed, wherein the east segmentation occurs one phase earlier than the west segmentation. The tectonic segmentations caused differences in the source rocks, resulting in the formation of two sets of source rocks that were mainly developed in the east basin, namely: the lacustrine source rocks and marine–continental transitional facies coal-series source rocks. Meanwhile, only one set of the marine-continent transitional facies coal-series source rocks and terrestrial marine facies source rocks was developed in the west basin. The segmentations also yielded differences in the reservoir characteristics, even though both basins developed marine–continental transitional facies as well as delta and deep-water gravity flow sandstone reservoirs; meanwhile, the eastern basin developed continental fluvial reservoirs. The differences in hydrocarbon accumulation were controlled by segmentation; at the east basin, structural ridges in shallow layers, deep lithologic–stratigraphic traps, and bulges in sags affected the accumulations of oil and gas. Meanwhile, at the west Qiongdongnan Basin, coal-bearing delta systems produced the gas distributions along the margins of the central subsidence that was adjacent to the source rocks.

This work discusses about a fast and efficient method of constructing an open 3D manipulator virtual simulation platform which make it easier for teachers and students to learn about positive and inverse kinematics of a robot manipulator. The method was carried out using MATLAB. In which, the Robotics Toolbox, MATLAB GUI and 3D animation with the help of modelling using SolidWorks, were fully applied to produce a good visualization of the system. The advantages of using quickly build is its powerful function of the input and output and its ability to simulate a 3D manipulator realistically. In this article, a Schunk six DOF modular manipulator was constructed by the author’s research group to be used as example. The implementation steps of this method was detailed described, and thereafter, a high-level open and realistic visualization manipulator 3D virtual simulation platform was achieved. With the graphs obtained from simulation, the test results show that the manipulator 3D virtual simulation platform can be constructed quickly with good usability and high maneuverability, and it can meet the needs of scientific research and teaching.