"It Felt Good to Be Included": A Mixed-Methods Study of Pre-Kindergarten Teachers' Experiences with Professional Learning.

This article reports findings from a study to investigate the efficacy beliefs, experiences, and instructional practices of pre-kindergarten (pre-k) teachers from a high-need district who engaged in collaborative professional learning experiences provided by a partner university. The study also examined language and literacy instruction for children in their pre-k classrooms. The professional learning occurred as part of a project to support pre-k teachers within the district and to boost teaching effectiveness. Researchers employed a mixed methods approach to investigate how pre-k teacher participants (a) perceived their efficacy as teachers; (b) experienced early literacy-focused professional learning; and (c) approached literacy teaching within their classrooms. Analysis of three years of data reveal alignment between participants' sense of efficacy and instructional strengths and areas for growth both self-reported and observed. Additionally, participants echoed feelings of exclusion from most professional learning experiences and offered insight into considerations for designing and delivering professional learning opportunities to effectively support pre-k teachers' literacy instructional practices. Supplementary Information: The online version contains supplementary material available at 10.1007/s10643-021-01175-4.

Weavable and Highly Efficient Organic Light-Emitting Fibers for Wearable Electronics: A Scalable, Low-Temperature Process.

Fiber-based wearable displays, one of the most desirable requisites of electronic textiles (e-textiles), have emerged as a technology for their capability to revolutionize textile and fashion industries in collaboration with the state-of-the-art electronics. Nonetheless, challenges remain for the fibertronic approaches, because fiber-based light-emitting devices suffer from much lower performance than those fabricated on planar substrates. Here, we report weavable and highly efficient fiber-based organic light-emitting diodes (fiber OLEDs) based on a simple, cost-effective and low-temperature solution process. The values obtained for the fiber OLEDs, including efficiency and lifetime, are similar to that of conventional glass-based counterparts, which means that these state-of-the-art, highly efficient solution processed planar OLEDs can be applied to cylindrical shaped fibers without a reduction in performance. The fiber OLEDs withstand tensile strain up to 4.3% at a radius of 3.5 mm and are verified to be weavable into textiles and knitted clothes by hand-weaving demonstrations. Furthermore, to ensure the scalability of the proposed scheme fiber OLEDs with several diameters of 300, 220, 120, and 90 µm, thinner than a human hair, are demonstrated successfully. We believe that this approach, suitable for cost-effective reel-to-reel production, can realize low-cost commercially feasible fiber-based wearable displays in the future.

Psychometric Properties of an Instrument to Measure Word Problem Solving Skills in Mathematics.

The purpose of this study is to examine the psychometric properties of an instrument to measure word problem solving skills in mathematics related to speed with 706 sixth grade Chinese and Singaporean students. Rasch measurement models were applied to examine the reliability, unidimensionality, rating scale functioning, item difficulty, and person difficulty. The differential item functioning (DIF) analysis was also performed to examine the differences in item difficulty estimates between Chinese and Singaporean students. Results suggest that the data satisfied the unidimensionality requirements of the Rasch model and that most of the item difficulty measures aligned the person ability distribution. The instrument demonstrated adequate reliability. The fit statistics were within acceptable limits for the vast majority of items, with a few exceptions. The rating scale structure functioned properly although the middle categories had very few observations. Deleting misfitting cases and collapsing middle categories slightly improved the psychometric properties. DIF analysis revealed that four items were more difficult for Chinese students whereas two other items were more difficult for the Singaporean students. Results also indicated that the Chinese participants scored higher than the Singaporean participants for 11 of the 14 items and the Singaporean students scored higher than their Chinese cohorts in the other 3 items. The validation of this instrument has implications for the teaching and learning of mathematical word problems in practice.

Microcavity effect using nanoparticles to enhance the efficiency of organic light-emitting diodes.

In this paper, in contrast with previously reported approaches, we suggest exploiting a microcavity effect using nanoparticles to improve the optical efficiency of organic light-emitting diodes (OLED). The method to input the nanoparticles inside the OLED device is simple and cost effective by virtue of employing a solution process using a spin coating fabrication method. Titanium dioxide (TiO2) nanoparticles were used to improve the reflection by its high refractive index. In tandem with optimized heights of the organic layers, the increased light reflectance at the anode side, which includes the TiO2 nanoparticle layer, improved the optical efficiency of the OLED device via the microcavity effect. In order to prove that the enhancement of the optical efficiency was due to an enhanced microcavity effect caused by TiO2 nanoparticles, a microcavity simulation was conducted. The electrical characteristics were not affected by the nanoparticles and a clear pixel image was maintained. The results in this paper show that a nanoparticle based microcavity effect can be exploited to enhance the optical efficiency of OLEDs.

Validating a developmental scale for young children using the Rasch model: applicability of the teaching strategies GOLD assessment system.

This article reports the results of an application of the Rasch rating scale model to the Teaching Strategies GOLD assessment system in a norm sample of children aged birth to 71 months. The analyses focused on the examination of dimensionality, rating scale effectiveness, the hierarchy of item difficulties, and the relationship of developmental scale scores to child age. Results show that each subscale satisfies the Rasch model for unidimensionality. Ratings were found to be less reliable at the lowest and highest ends of the scale and less distinct at 'In-between' levels. Items appear to form theoretically expected hierarchies, supporting evidence for construct validity for the measures. Moderately high correlations of developmental scale scores with child age suggest that teachers are able to make valid ratings of the developmental progress of children across the intended age range.

Quantum-Dot Light-Emitting Fiber Toward All-In-One Clothing-Type Health Monitoring.

In the Fourth Industrial Revolution, as the connection between objects and people becomes increasingly important, interest in wearable optoelectronic device-based medical diagnosis is on the rise. Pulse oximetry sensors based on a fiber platform, which is the smallest unit of clothing, could be considered an attractive candidate for this application. In this study, red and green quantum-dot light-emitting fibers (QDLEFs) based on a 250 µm-diameter 1-dimensional fiber were successfully implemented, achieving high current efficiencies of approximately 22.46 mW/sr/A and 23.6 mW/sr/A and narrow full-width at half-maximum (FWHM) of about 33 nm, respectively. In addition, its omnidirectional flexibility was confirmed through a vertical and lateral bending test with 0.92% strain. By employing a transparent and flexible elastomer, a wearable pulse oximeter incorporating QDLEFs was successfully demonstrated for oxygen saturation level (SpO2) monitoring on finger and wrist. It was demonstrated to be washable, and could be operated for up to about 18 h. Due to the elastomer and bottom emission, it exhibited excellent wear resistance characteristics in a 50 cycle reciprocating test conducted at about 2180.43 kPa with 220-grit abrasive paper sheet. A theoretical investigation based on modified photon diffusion analysis (MPDA) modeling also determined that using narrow FWHM light sources, such as QDLEFs, improves the resolution and accuracy of SpO2 monitoring. Accordingly, the proposed QDLEF showed distinguished potential as an all-in-one clothing type pulse oximetry.

Highly Conductive Transparent and Flexible Electrodes Including Double-Stacked Thin Metal Films for Transparent Flexible Electronics.

To keep pace with the era of transparent and deformable electronics, electrode functions should be improved. In this paper, an innovative structure is suggested to overcome the trade-off between optical and electrical properties that commonly arises with transparent electrodes. The structure of double-stacked metal films showed high conductivity (<3 Ω/sq) and high transparency (∼90%) simultaneously. A proper space between two metal films led to high transmittance by an optical phenomenon. The principle of parallel connection allowed the electrode to have high conductivity. In situ fabrication was possible because the only materials composing the electrode were silver and WO3, which can be deposited by thermal evaporation. The electrode was flexible enough to withstand 10 000 bending cycles with a 1 mm bending radius. Furthermore, a few µm scale patterning of the electrode was easily implemented by using photolithography, which is widely employed industrially for patterning. Flexible organic light-emitting diodes and a transparent flexible thin-film transistor were successfully fabricated with the proposed electrode. Various practical applications of this electrode to new transparent flexible electronics are expected.

Highly conductive and flexible color filter electrode using multilayer film structure.

In this paper, a high performance flexible component that serves as a color filter and an electrode simultaneously is suggested. The suggested highly conductive and flexible color filter electrode (CFE) has a multilayer film structure composed of silver (Ag) and tungsten trioxide (WO3). The CFE maintained its color filtering capability even when the films were bent on a polyethylene terephthalate (PET) film. Low sheet resistance of the CFE was obtained using WO3 as a bridge layer that connects two Ag layers electrically. The sheet resistance was less than 2 Ω/sq. and it was negligibly changed after bending the film, confirming the flexibility of the CFE. The CFE can be easily fabricated using a thermal evaporator and is easily patterned by photolithography or a shadow mask. The proposed CFE has enormous potential for applications involving optical devices including large area devices and flexible devices.

Organolead Halide Perovskites for Low Operating Voltage Multilevel Resistive Switching.

Organolead halide perovskites are used for low-operating-voltage multilevel resistive switching. Ag/CH3 NH3 PbI3 /Pt cells exhibit electroforming-free resistive switching at an electric field of 3.25 × 10(3) V cm(-1) for four distinguishable ON-state resistance levels. The migration of iodine interstitials and vacancies with low activation energies is responsible for the low-electric-field resistive switching via filament formation and annihilation.

A Rasch rating scale modeling of the Schutte Self-Report Emotional Intelligence scale in a sample of international students.

This study examined the psychometric properties of the Schutte Self-Report Emotional Intelligence (SSREI) scale in a sample of international students studying in the U.S. universities using Rasch analysis. The results indicated that the original five-category rating structure may not function effectively for the international student sample. The results also revealed that although most of the items in the SSREI scale contributed to a single underlying construct, reverse-keyed items appeared to be problematic. Examination of the person-item map suggested that the items may be inappropriately targeted for this sample. In sum, the original version of the SSREI scale needs further improvement to adequately measure emotional intelligence.