Psychometric Characteristics of Childbearing Motivation Questionnaire: A Review

Background: Considering the important role of understanding the childbearing motivations in counseling services about childbearing behavior, and need for applying a valid and reliable instrument to assess it in Iranian society, this study was conducted to determine Childbearing motivation. Questionnaire was validated in two versions including Persian and English. The review aimed to comprehensively review the validity and reliability of Childbearing Motivation Questionnaire to provide comprehensive information to health providers. Materials and Methods: We conducted an extensive search on online databases (Medline, EMBASE. Web of Science, Scopus, Cochrane Library, and CINAHL) from inception until September 2019. The following keywords were used: ("Childbearing Questionnaire" OR "CBQ") AND ("Factor Analysis" OR "Exploratory Factor Analysis" OR "Confirmatory Factor Analysis" OR "Reliability" OR "Psychometric" OR "Cronbach's alpha" OR "Test-retest Reliability" OR "Intra-class Correlation Coefficient" OR "ICC"). COSMIN checklist was used to assess the methodological quality of studies. Results: Three studies were included in review. Intra-class correlation coefficient (ICC), Cronbach's alpha coefficient and the test-retest reliability indicated satisfactory reliability of the CBQ. Original version of Childbearing Motivation Questionnaire was developed by Miller (1995). In Persian version, original model did not show the 'acceptable' fit. After removing eight factors with low loading and two correlated error terms, modified model was found to have "adequate" fitness (Comparative Fit Index (CFI=.91), Tucker-Lewis Index (TLI=.90), Root Mean Square Error of Approximation (RMSEA=.04), and Chi-square to degree of freedom x2/df=1.92). Conclusion: The Persian and English version of childbearing motivation has good construct validity and reliability. Future research needs to test six-factor model with 49 total items and modified model with 43 items in various populations

Ultra-thin electrospun nanofibers for development of damage-tolerant composite laminates

The present article overcomes existing challenges in inter-laminar toughening of novel multifunctional fiber-reinforced polymer composites via development and embedment of highly stretched, ultra-thin electrospun thermoplastic nanofibers made of polyamide 6.6. The nanofibers exhibit significant enhancement of the composite laminate's structural integrity with almost zero weight penalty via ensuring a smooth stress transfer throughout the plies and serving tailoring mechanical properties in desired directions, with no interference with geometric features, e.g., thickness. The findings for 1.5 g per square meter electrospun nanofibers have demonstrated, on test coupon specimens, improvements up to 85% and 43% in peak load and crack opening displacement, respectively, with significant improvement (>25%) and no sacrifice of fracture toughness at both initiation and propagation phases. The initial stiffness for the modified specimens was improved by nearly 150%. The enhancement is mainly due to nanofibers contributing to the stiffness of the resin-rich area at the crack tip adjacent to the polytetrafluoroethylene (PTFE) film. Glass fiber-reinforced woven phenolic pre-impregnated composite plies have been modified with the nanofibers (each layer having an average thickness of 2.0 gsm) degrades the adhesion properties (chemical bonding) between glass fibers and the phenolic matrix. The density of nanofibers increases, so does the likelihood of forming a physical barrier between the plies resulting in the loss of resin flow and poor adhesion. Such an effect was evident from microscopic investigations and reduction in fracture toughness data at the initiation and propagation phases