EFFECT OF HAND PLACEMENT POSITION ON PRESS-TO-HANDSTAND TECHNIQUES AND STABILITY

Considerable variations in hand placement positions are seen among gymnasts when executing a press-to-handstand. The purpose of this study was to investigate the effect of hand placement position on press-to-handstand techniques and stability. Three male gymnasts performed two press-to-handstands in different hand positions (fingers pointing forward and outward) on a force platform. Postural sway variables were measured to assess stability. Video recordings were taken to obtain temporal and kinematic measurements. Results showed pressing to handstand in fingers outward position was characterised by less postural sway, less extended body alignment and a more under-rotated handstand orientation. These can be seen strategies to adjust the centre of mass towards a more anterior position to avoid over-rotation

Integrative Literature Review on the Antecedents of Informal Learning in the Workplace: A Conceptual Framework for Future Research

Despite the explosion of interest in informal learning in the workplace, few attempts have been made to synthesize the current literature. This article provides an integrative and analytical review of prior empirical studies, particularly focusing on what factors have been identified as antecedents of informal learning in organizations and how informal learning has been conceptualized and measured. It then suggests future avenues for theory building, research, and practice. The authors propose a conceptual framework for understanding informal learning activities using three dimensions: learning competence, intentionality, and developmental relatedness. Implications for human resource development research and practice are also discussed

In situ-prepared composite materials of PEDOT: PSS buffer layer-metal nanoparticles and their application to organic solar cells

We report an enhancement in the efficiency of organic solar cells via the incorporation of gold (Au) or silver (Ag) nanoparticles (NPs) in the hole-transporting buffer layer of poly(3,4- ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), which was formed on an indium tin oxide (ITO) surface by the spin-coating of PEDOT:PSS-Au or Ag NPs composite solution. The composite solution was synthesized by a simple in situ preparation method which involved the reduction of chloroauric acid (HAuCl4) or silver nitrate (AgNO3) with sodium borohydride (NaBH4) solution in the presence of aqueous PEDOT:PSS media. The NPs were well dispersed in the PEDOT:PSS media and showed a characteristic absorption peak due to the surface plasmon resonance effect. Organic solar cells with the structure of ITO/PEDOT:PSS-Au, Ag NPs/poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PC61BM)/LiF/Al exhibited an 8% improvement in their power conversion efficiency mainly due to the enlarged surface roughness of the PEDOT:PSS, which lead to an improvement in the charge collection and ultimately improvements in the short-circuit current density and fill factor. © 2012 Woo et al.1

The critical role of job embeddedness: The impact of psychological empowerment and learning orientation on organizational commitment

Job embeddedness (JE) has been recognized as a key factor to address the issue of employee turnover and employee attitudes. This study explores underlying mechanisms of job embeddedness that link the organizational environment and the individuals’ perceptions of the job. Particularly, the effects of psychological empowerment and learning orientation on organizational commitment were examined. This study hypothesizes that psychological empowerment (PE) and learning orientation (LO) should influence organizational commitment (OC) and job embeddedness plays a significant mediating role in these relationships. Data were collected from 27 offices of Human Resource Development Service of Korea (governmental agency) located in major cities in South Korea. Results indicate that all hypothesized relationships (PE and JE, LO and JE, LO and OC, JE and OC, and the mediating role of JE) are supported, except for psychological empowerment and organizational commitment. While the impact of psychological empowerment was not significantly related to organizational commitment, it is notable that through job embeddedness, psychological empowerment had indirect effects on organizational commitment. Further, learning orientation had significant effects on job embeddedness and organizational commitment. Lastly, the most compelling finding is a full mediation of job embeddedness in the relationship between psychological empowerment and organization commitment. Implications for research and practice are discussed

Rapid Dye Regeneration Mechanism of Dye-Sensitized Solar Cells

During the light-harvesting process of dye-sensitized solar cells (DSSCs), the hole localized on the dye after the charge separation yields an oxidized dye, D^+. The fast regeneration of D^+ using the redox pair (typically the I^–/I_(3)^– couple) is critical for the efficient DSSCs. However, the kinetic processes of dye regeneration remain uncertain, still promoting vigorous debates. Here, we use molecular dynamics simulations to determine that the inner-sphere electron-transfer pathway provides a rapid dye regeneration route of ∼4 ps, where penetration of I^− next to D^+ enables an immediate electron transfer, forming a kinetic barrier. This explains the recently reported ultrafast dye regeneration rate of a few picoseconds determined experimentally. We expect that our MD based comprehensive understanding of the dye regeneration mechanism will provide a helpful guideline in designing TiO_2−dye−electrolyte interfacial systems for better performing DSSCs

Comparison of emergency cranial CT interpretation between radiology residents and neuroradiologists: transverse versus three-dimensional images

PURPOSEThree-dimensional (3D) reformatted images provide a more inclusive representation of abnormalities than transverse images in cranial computed tomography (CT). The purpose of this study was to assess the value of 3D reformations for radiology residents in the interpretation of emergency cranial CTs.MATERIALS AND METHODSIn total, 218 consecutive patients who underwent emergency cranial CT scans with 3D reformation were included in this retrospective study. Four blinded readers (three radiology residents and a neuroradiologist) interpreted the transverse and 3D images in two separate sessions. Each reader assessed 1) abnormal finding(s) and the confidence score(s) (5-point scale) for transverse and 3D images, 2) added value score of 3D images (5-point scale), and 3) interpretation time for both transverse and 3D images. We analyzed discordance between each radiology resident and the neuroradiologist on a lesion-by-lesion basis.RESULTSIn total, 509 lesions were detected in 218 patients. Discordance rates between the three residents and the neuroradiologist were 11.4%–20.2% (mean, 15.0%) and 8.8%–16.9% (mean, 12.1%) in the interpretation of transverse and 3D images, respectively. Confidence scores were higher for 3D images than for transverse images for all readers. The added value scores for the 3D images were relatively higher for the inexperienced residents. Interpretation times for 3D images were significantly higher than for transverse images for all readers.CONCLUSIONThe 3D reformations assist radiology residents in the interpretation of emergency cranial CT examinations

Full-Color LCD Microdisplay System Based on OLED Backlight Unit and Field-Sequential Color Driving Method

We developed a single-panel LCD microdisplay system using a field-sequential color (FSC) driving method and an organic light-emitting diode (OLED) as a backlight unit (BLU). The 0.76′′ OLED BLU with red, green, and blue (RGB) colors was fabricated by a conventional UV photolithography patterning process and by vacuum deposition of small molecule organic layers. The field-sequential driving frequency was set to 255 Hz to allow each of the RGB colors to be generated without color mixing at the given display frame rate. A prototype FSC LCD microdisplay system consisting of a 0.7′′ LCD microdisplay panel and the 0.76′′ OLED BLU successfully exhibited color display and moving picture images using the FSC driving method

Effects of a dianion compound as a surface modifier on the back reaction of photogenerated electrons in TiO2-based solar cells

The TiO2 films were modified with a dianion compound, 1,2-ethanedisulfonic acid disodium salt (ESD), to give a negative charge (ethane sulfonate anion) on the TiO2 surface, i.e., TiO2-O-SO2-CH2-CH2-SO3 −), and effects of repulsion between the negative charge and ions (I3 −) of the electrolyte on the performance of dye-sensitized solar cells (DSSCs) were investigated. The reference device without any modification showed a power conversion efficiency (PCE) of 9.89%, whereas for the device with ESD(20)-TiO2/FTO, which was prepared by soaking bare TiO2/FTO in an ESD solution for 20 min, the PCE was increased to 10.97%, due to an increase in both short-circuit current (Jsc) and open-circuit voltage(Voc). It was verified from the measurements of electrochemical impedance, open-circuit voltage decay and dark current that the enhancement in the Jsc and Voc values was attributed to the reduced back reaction between photoinjected electrons and I3 − ions, resulting from the presence of the ethane sulfonate anions on the TiO2 surface. © 2018 King Saud University1