Development and validation of the Chinese version of the evidence-based practice profile questionnaire (EBP2Q)

BACKGROUND

Evidence-based practice (EBP) education or training are considered fundamental to building and strengthening an EBP culture, as well as to encouraging evidence-based academic and clinical practice in the nursing community. However, few valid and reliable instruments are available for the assessment of EBP teaching and learning in clinical nurses in China. Translation, reliability, and validity testing of the English Evidence-Based Practice Profile Questionnaire (EBP²Q), which has strong psychometric properties, may encourage evaluation and promote the implementation of EBP in Mainland China.

METHODS

Based on established guidelines for the development of questionnaires, the English EBP²Q was translated and cross-culturally adapted. The Chinese version of the EBP²Q (EBP²Q-C) was validated using a sample of 543 nurses. Structural validity was evaluated through exploratory factor analysis and confirmatory factor analysis, and the questionnaire was tested for convergent and criterion validity. The internal consistency and test-retest reliability were also evaluated.

RESULTS

The content validity index demonstrated good content validity (≥0.98). An eight-factor structure was obtained in the exploratory factor analysis, and verified by a three-order factor model from the confirmatory factor analysis (χ²/df = 2.001; RMSEA = 0.065; SRMR = 0.077; and CFI = 0.884). The Spearman's rank correlation analysis of the EBP²Q-C with the Evidence-Based Practice Questionnaire showed moderate correlations for Practice (0.58) and Confidence (0.68) and a low correlation for Sympathy (0.32). Criterion validity was demonstrated by significant differences in terms of nurses' highest education, present position, EBP training, involvement in research programs, and level of understanding of English. Both the overall Cronbach's α and the Cronbach's α for the domains exceeded 0.70. The intraclass correlation coefficients for the domains ranged between 0.75 and 0.96, indicating satisfactory repeatability.

CONCLUSIONS

Except for the convergent validity of the Sympathy domain, the EBP²Q-C provided evidence of validity and reliability. Therefore, it can be applied in EBP education or training assessment in Mainland China.

Rotary ultrasonic machining of CFRP: A comparison with grinding

Carbon fiber reinforced plastic (CFRP) composites have been intensively used in various industries due to their superior properties. In aircraft and aerospace industry, a large number of holes are required to be drilled into CFRP components at final stage for aircraft assembling. There are two major types of methods for hole making of CFRP composites in industry, twist drilling and its derived multi-points machining methods, and grinding and its related methods. The first type of methods are commonly used in hole making of CFRP composites. However, in recent years, rotary ultrasonic machining (RUM), a hybrid machining process combining ultrasonic machining and grinding, has also been successfully used in drilling of CFRP composites. It has been shown that RUM is superior to twist drilling in many aspects. However, there are no reported investigations on comparisons between RUM and grinding in drilling of CFRP. In this paper, these two drilling methods are compared in five aspects, including cutting force, torque, surface roughness, hole diameter, and material removal rate.

Preliminary study on rotary ultrasonic machining of CFRP/Ti stacks

Reported drilling methods for CFRP/Ti stacks include twist drilling, end milling, core grinding, and their derived methods. The literature does not have any report on drilling of CFRP/Ti stacks using rotary ultrasonic machining (RUM). This paper, for the first time, reports a study on drilling of CFRP/Ti stacks using RUM. It also compares results on drilling of CFRP/Ti stacks using RUM with reported results on drilling of CFRP/Ti stacks using other methods. When drilling CFRP/Ti stacks using RUM, cutting force, torque, and CFRP surface roughness were lower, hole size variation was smaller, CFRP groove depth was smaller, tool life was longer, and there was no obvious Ti exit burr and CFRP entrance delamination. Ti surface roughness when drilling of CFRP/Ti stacks using RUM was about the same as those when using other methods.

Rotary ultrasonic machining of CFRP: a mechanistic predictive model for cutting force

Cutting force is one of the most important output variables in rotary ultrasonic machining (RUM) of carbon fiber reinforced plastic (CFRP) composites. Many experimental investigations on cutting force in RUM of CFRP have been reported. However, in the literature, there are no cutting force models for RUM of CFRP. This paper develops a mechanistic predictive model for cutting force in RUM of CFRP. The material removal mechanism of CFRP in RUM has been analyzed first. The model is based on the assumption that brittle fracture is the dominant mode of material removal. CFRP micromechanical analysis has been conducted to represent CFRP as an equivalent homogeneous material to obtain the mechanical properties of CFRP from its components. Based on this model, relationships between input variables (including ultrasonic vibration amplitude, tool rotation speed, feedrate, abrasive size, and abrasive concentration) and cutting force can be predicted. The relationships between input variables and important intermediate variables (indentation depth, effective contact time, and maximum impact force of single abrasive grain) have been investigated to explain predicted trends of cutting force. Experiments are conducted to verify the model, and experimental results agree well with predicted trends from this model.

Rotary ultrasonic machining of CFRP composites: a study on power consumption

Carbon fiber reinforced plastic (CFRP) composites are very difficult to machine. A large number of holes need to be drilled in CFRP for many applications. Therefore, it is important to develop cost-effective drilling processes. CFRP has been drilled by rotary ultrasonic machining (RUM) successfully. The literature has reports about the effects of input variables on output variables (including cutting force, torque, surface roughness, tool wear, and workpiece delamination) in RUM of CFRP. However, there are no reports on power consumption in RUM of CFRP. This paper reports the first study on power consumption in RUM of CFRP. It reports an experimental investigation on effects of input variables (ultrasonic power, tool rotation speed, feedrate, and type of CFRP) on power consumption of each component (including ultrasonic power supply, spindle motor, coolant pump, and air compressor) and the entire RUM system.