Adel S. Abduljabbar

Passion: Does one scale fit all? Construct validity of two-factor passion scale and psychometric invariance over different activities and languages.

The passion scale, based on the dualistic model of passion, measures 2 distinct types of passion: Harmonious and obsessive passions are predictive of adaptive and less adaptive outcomes, respectively. In a substantive-methodological synergy, we evaluate the construct validity (factor structure, reliability, convergent and discriminant validity) of Passion Scale responses (N = 3,571). The exploratory structural equation model fit to the data was substantially better than the confirmatory factor analysis solution, and resulted in better differentiated (less correlated) factors. Results from a 13-model taxonomy of measurement invariance supported complete invariance (factor loadings, factor correlations, item uniquenesses, item intercepts, and latent means) over language (French vs. English; the instrument was originally devised in French, then translated into English) and gender. Strong measurement partial invariance over 5 passion activity groups (leisure, sport, social, work, education) indicates that the same set of items is appropriate for assessing passion across a wide variety of activities--a previously untested, implicit assumption that greatly enhances practical utility. Support was found for the convergent and discriminant validity of the harmonious and obsessive passion scales, based on a set of validity correlates: life satisfaction, rumination, conflict, time investment, activity liking and valuation, and perceiving the activity as a passion.

Juxtaposing Math Self-Efficacy and Self-Concept as Predictors of Long-Term Achievement Outcomes.

In this study, we tested the hypothesis that self-efficacy and self-concept reflect different underlying processes and both are critical to understanding long-term achievement outcomes. Although both types of self-belief are well established in educational psychology, research comparing and contrasting their relationship with achievement has been surprisingly sparse. This is particularly the case when considering critical developmental periods and high-stakes achievement outcomes. In the current research, we use the longitudinal study of Australian youth which uses the 2003 Australian Programme of International Student Assessment cohort (N = 10,370; M [age] = 15) as the first time wave and follows participants over eight years. Using latent path modelling and controlling for a wide range of background covariates, we found: (a) strong relations between achievement, self-efficacy and self-concept in mathematics at age 15; (b) both self-concept and self-efficacy were independent and similarly strong predictors of tertiary entrance ranks at the end of high school; (c) math self-efficacy was a significant predictor of university entry but math self-concept was not; and (d) math self-concept was a significant predictor of undertaking post-school studies in science, technology, engineering or math, but math self-efficacy was not.

Equilibrium and kinetic mechanisms of woody biochar on aqueous glyphosate removal.

We investigated the removal of aqueous glyphosate using woody (dendro) biochar obtained as a waste by product from bioenergy industry. Equilibrium isotherms and kinetics data were obtained by adsorption experiments. Glyphosate adsorption was strongly pH dependent occurring maximum in the pH range of 5-6. The protonated amino moiety of the glyphosate molecule at this pH may interact with π electron rich biochar surface via π-π electron donor-acceptor interactions. Isotherm data were best fitted to the Freundlich and Temkin models indicating multilayer sorption of glyphosate. The maximum adsorption capacity of dendro biochar for glyphosate was determined by the isotherm modeling to be as 44 mg/g. Adsorption seemed to be quite fast, reaching the equilibrium <1 h. Pseudo-second order model was found to be the most effective in describing kinetics whereas the rate limiting step possibly be chemical adsorption involving valence forces through sharing or exchanging electrons between the adsorbent and sorbate. The FTIR spectral analysis indicated the involvement of functional groups such as phenolic, amine, carboxylic and phosphate in adsorption. Hence, a heterogeneous chemisorption process between adsorbate molecules and functional groups on biochar surface can be suggested as the mechanisms involved in glyphosate removal.

The Internal/External Frame of Reference Model of Self-Concept and Achievement Relations: Age-Cohort and Cross-Cultural Differences

The internal/external frame of reference (I/E) model and dimensional comparison theory posit paradoxical relations between achievement (ACH) and self-concept (SC) in mathematics (M) and verbal (V) domains; ACH in each domain positively affects SC in the matching domain (e.g., MACH to MSC) but negatively in the nonmatching domain (e.g., MACH to VSC). This substantive-methodological synergy based on latent variable models of Trends in International Mathematics and Science Study (TIMSS) data supports the generalizability of these predictions in relation to: mathematics and science domains, intrinsic motivation as well as self-concept, and age and nationality, based on nationally representative matched samples of fourth- and eighth-grade students from three Middle Eastern Islamic, five Western, and four Asian countries (N=117,321 students) with important theoretical, developmental, cross-cultural, and methodological implications.

Smartphone addiction among university students in the light of some variables

We explored the frequency and indices of smartphone addiction in a group of King Saud University students and investigated whether there were differences in smartphone addiction based on gender, social status, educational level, monthly income and hours of daily use. We developed a questionnaire probing smartphone addiction consisting of five dimensions: 1) overuse of smartphone, 2) the psychological-social dimension, 3) the health dimension, 4) preoccupation with smartphones, and 5) the technological dimension. After being validated, the questionnaire was administered to 416 students, both male and female, at King Saud University. Results revealed that addiction percentage among participants was 48%. The order of smartphone addiction indices were as follows: overuse of smartphone, the technological dimension, the psychological-social dimension, preoccupation with smartphones, and the health dimension. Significant gender differences were found in the degree of addiction on the whole questionnaire and all of its dimensions with the exception of the technological dimension in favor of males. Significant differences by social status were found in favor of the unmarried. Bachelor degree students were found to have the highest degree of addiction. Significant differences by hours of daily use were also detected in favor of participants using the smartphone for more than 4źh a day. As to the monthly income dimension, significant differences were found on the health dimension in favor of participants with lower monthly income. The addiction percentage among participants was 48%.There are Significant gender and social status differences were found in the degree of addiction.There are significant differences due to monthly income were found in the degree of addiction.Bachelor degree students were found to have the highest degree of addiction.There are significant differences due to hours of daily use were found in degree of addiction.

The Big-Fish-Little-Pond Effect in Mathematics A Cross-Cultural Comparison of U.S. and Saudi Arabian TIMSS Responses

This substantive-methodological synergy demonstrates evolving multilevel latent-variable models for cross-cultural data. Using Trends in International Mathematics and Science Study (TIMSS) 2007 data for U.S. and Saudi Arabian eighth grade students, we evaluate the psychometric properties (measurement invariance, method effects, and gender differences) of math self-concept, positive affect, coursework aspirations, and achievement. Extending the studies of the “paradoxical cross-cultural self-concept effect” largely based on U.S.-Asian comparisons, country-level differences strongly favored the United States for achievement test scores, but favored Saudi Arabia for self-concept and aspirations. Latent mean gender differences, of particular interest because of Saudi Arabia’s single-sex school system, interacted with country for all constructs. The largest interaction was for achievement test scores; there were no significant gender differences for U.S. students (in coed schools), but in single-sex Saudi schools, Saudi girls performed substantially better than Saudi boys. Consistently with previous (mostly Western) research, but not previously evaluated with TIMSS, in each of the four (2 gender × 2 country) groups all three outcomes (self-concept, affect, and aspiration) were positively influenced by individual student achievement but negatively influenced by class-average achievement (the Big-Fish-Little-Pond Effect: BFLPE). BFLPEs were similar in size for boys and girls in coeducational (United States) and in single-sex (Saudi) classrooms.

Validity of Social, Moral and Emotional Facets of Self-Description Questionnaire II

Studies adopting a construct validity approach can be categorized into within- and between-network studies. Few studies have applied between-network approach and tested the correlations of the social (same-sex relations, opposite-sex relations, parent relations), moral (honesty-trustworthiness), and emotional (emotional stability) facets of the Self-Description Questionnaire II with external criteria. Using a sample of high school students (n = 628), the authors examined the relations of these 5 nonacademic self-concept facets with nonacademic external criteria (between-network studies) besides examining the factor structure of these five facets of self-concept (within-network studies). Results provided strong support for the convergent validity in that each predicted correlation was statistically significant. Also, the discriminant validity of the 5 nonacademic subscales was clearly demonstrated by showing that each external criterion was more highly correlated with the predicted (matching) Self-Description Questionnaire II subscale than any of the Self-Description Questionnaire II subscales. Hence, these facets of self-concept are 5 distinct factors.

Domain Specificity Between Peer Support and Self-Concept

Peer support interventions have mostly neglected the domain specificity of intervention effects. In two studies, the present investigation examined the domain specificity of peer support interventions targeting specific domains of self-concept. In Study 1, participants (n = 50) who had received an academically oriented peer support intervention on verbal subject matter improved significantly in verbal self-concept—but not other areas of self-concept—as compared with a control group that had not participated in the intervention. In Study 2, participants (n = 53) who had received a socially oriented peer support intervention that focused on interpersonal skills and communication improved significantly in same-sex relations self-concept—but not in other areas of self-concept—as compared with the control group. Hence, there is a compelling need for reconceptualizing peer support into academic and social domains in terms of domain specificity.

Correction to: Date palm waste biochars alter a soil respiration, microbial biomass carbon, and heavy metal mobility in contaminated mined soil

Unfortunately, in the original publication of the article, Prof. Yang Sik Ok’s affiliation was incorrectly published. The author’s affiliation is as follows.

An efficient phosphorus scavenging from aqueous solution using magnesiothermally modified bio-calcite

ABSTRACT Bio-calcite (BC) derived from waste hen eggshell was subjected to thermal treatments (calcined bio-calcite (CBC)). The BC and CBC were further modified via magnesiothermal treatments to produce modified bio-calcite (MBC) and modified calcined bio-calcite (MCBC), respectively, and evaluated as a novel green sorbent for P removal from aqueous solutions in the batch experiments. Modified BC exhibited improved structural and chemical properties, such as porosity, surface area, thermal stability, mineralogy and functional groups, than pristine material. Langmuir and Freundlich models well described the P sorption onto both thermally and magnesiothermally sorbents, respectively, suggesting mono- and multi-layer sorption. Langmuir predicted highest P sorption capacities were in the order of: MCBC (43.33 mg g−1) > MBC (35.63 mg g−1) > CBC (34.38 mg g−1) > BC (30.68 mg g−1). The MBC and MCBC removed 100% P up to 50 mg P L−1, which reduced to 35.43 and 39.96%, respectively, when P concentration was increased up to 1000 mg L−1. Dynamics of P sorption was well explained by the pseudo-second-order rate equation, with the highest sorption rate of 4.32 mg g−1 min−1 for the MCBC. Hydroxylapatite [Ca10(PO4)6(OH)2] and brushite [CaH(PO4)·2H2O] were detected after P sorption onto the modified sorbents by X-ray diffraction analysis, suggesting chemisorption as the operating sorption mechanism. GRAPHICAL ABSTRACT