127 research outputs found
Ga-doped Pt-Ni Octahedral Nanoparticles as a Highly Active and Durable Electrocatalyst for Oxygen Reduction Reaction
Bimetallic PtNi nanoparticles have been considered as a promising electrocatalyst for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) owing to their high catalytic activity. However, under typical fuel cell operating conditions, Ni atoms easily dissolve into the electrolyte, resulting in degradation of the catalyst and the membrane-electrode assembly (MEA). Here, we report gallium-doped PtNi octahedral nanoparticles on a carbon support (Ga-PtNi/C). The Ga-PtNi/C shows high ORR activity, marking an 11.7-fold improvement in the mass activity (1.24 A mgPt-1) and a 17.3-fold improvement in the specific activity (2.53 mA cm-2) compare to the commercial Pt/C (0.106 A mgPt-1 and 0.146 mA cm-2). Density functional theory calculations demonstrate that addition of Ga to octahedral PtNi can cause an increase in the oxygen intermediate binding energy, leading to the enhanced catalytic activity toward ORR. In a voltage-cycling test, the Ga-PtNi/C exhibits superior stability to PtNi/C and the commercial Pt/C, maintaining the initial Ni concentration and octahedral shape of the nanoparticles. Single cell using the Ga-PtNi/C exhibits higher initial performance and durability than those using the PtNi/C and the commercial Pt/C. The majority of the Ga-PtNi nanoparticles well maintain the octahedral shape without agglomeration after the single cell durability test (30,000 cycles). This work demonstrates that the octahedral Ga-PtNi/C can be utilized as a highly active and durable ORR catalyst in practical fuel cell applications
Ga-doped Pt-Ni Octahedral Nanoparticles as a Highly Active and Durable Electrocatalyst for Oxygen Reduction Reaction
Bimetallic PtNi nanoparticles have been considered as a promising electrocatalyst for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) owing to their high catalytic activity. However, under typical fuel cell operating conditions, Ni atoms easily dissolve into the electrolyte, resulting in degradation of the catalyst and the membrane-electrode assembly (MEA). Here, we report gallium-doped PtNi octahedral nanoparticles on a carbon support (Ga-PtNi/C). The Ga-PtNi/C shows high ORR activity, marking an 11.7-fold improvement in the mass activity (1.24 A mgPt-1) and a 17.3-fold improvement in the specific activity (2.53 mA cm-2) compare to the commercial Pt/C (0.106 A mgPt-1 and 0.146 mA cm-2). Density functional theory calculations demonstrate that addition of Ga to octahedral PtNi can cause an increase in the oxygen intermediate binding energy, leading to the enhanced catalytic activity toward ORR. In a voltage-cycling test, the Ga-PtNi/C exhibits superior stability to PtNi/C and the commercial Pt/C, maintaining the initial Ni concentration and octahedral shape of the nanoparticles. Single cell using the Ga-PtNi/C exhibits higher initial performance and durability than those using the PtNi/C and the commercial Pt/C. The majority of the Ga-PtNi nanoparticles well maintain the octahedral shape without agglomeration after the single cell durability test (30,000 cycles). This work demonstrates that the octahedral Ga-PtNi/C can be utilized as a highly active and durable ORR catalyst in practical fuel cell applications
Boundary management preferences from a gender and cross-cultural perspective
Although work is increasingly globalized and mediated by technology, little research has accu-
mulated on the role of culture in shaping individuals' preferences regarding the segmentation or
integration of their work and family roles. This study examines the relationships between gender
egalitarianism (the extent a culture has a fluid understanding of gender roles and promotes
gender equality), gender, and boundary management preferences across 27 countries/territories.
Based on a sample of 9362 employees, we found that the pattern of the relationship between
gender egalitarianism and boundary management depends on the direction of segmentation
preferences. Individuals from more gender egalitarian societies reported lower preferences to
segment family-from-work (i.e., protect the work role from the family role); however, gender
egalitarianism was not directly associated with preferences to segment work-from-family.
Moreover, gender was associated with both boundary management directions such that women
preferred to segment family-from-work and work-from-family more so than did men. As theo-
rized, we found gender egalitarianism moderated the relationship between gender and segmen-
tation preferences such that women's desire to protect family from work was stronger in lower (vs.
higher) gender egalitarianism cultures. Contrary to expectations, women reported a greater
preference to protect work from family than men regardless of gender egalitarianism. Implica-
tions for boundary management theory and the cross-national work-family literature are
discussed
Humane Orientation, Work–Family Conflict, and Positive Spillover Across Cultures
Although cross-national work–family research has made great strides in recent decades, knowledge
accumulation on the impact of culture on the work–family interface has been hampered by a limited
geographical and cultural scope that has excluded countries where cultural expectations regarding work,
family, and support may differ. We advance this literature by investigating work–family relationships in a
broad range of cultures, including understudied regions of the world (i.e., Sub-Saharan Africa, Southern Asia).
We focus on humane orientation (HO), an overlooked cultural dimension that is however central to the
study of social support and higher in those regions. We explore its moderating effect on relationships
between work and family social support, work–family conflict, and work–family positive spillover.
Building on the congruence and compensation perspectives of fit theory, we test alternative hypotheses on a sample of 10,307 participants from 30 countries/territories. We find HO has mostly a compensatory role
in the relationships between workplace support and work-to-family conflict. Specifically, supervisor and
coworker supports were most strongly and negatively related to conflict in cultures in which support is most
needed (i.e., lower HO cultures). Regarding positive spillover, HO has mostly an amplifying role. Coworker
(but not supervisor) support was most strongly and positively related to work-to-family positive spillover in
higher HO cultures, where providing social support at work is consistent with the societal practice of providing
support to one another. Likewise, instrumental (but not emotional) family support was most strongly and
positively related to family-to-work positive spillover in higher HO cultures
Examining the Relationship Between Work-to-Family Conflict and Parenting Behavior
Although work-family conflict (WFC) has been of particular interest to work-family researchers, little attention has been paid to the consequences of WFC that reside in the family domain. Research on WFC and child outcomes is especially scant. The current study addresses the gap in the literature by investigating the relationship between work-interfere-with-family (WIF) and three forms of parent-child interaction behavior (PB): physical and recreational PB (PRPB), cognitive and academic-oriented PB (CAPB), and passive and maintenance-oriented PB (PMPB). The mechanism by which WIF relates to PB was further investigated by examining negative emotion as a mediator and trait guilt as a moderator of the relationship.
Employed parents of early school-aged children (n = 201) participated in the survey. Results indicated that both time- and strain-based WIF were negatively related to two types of active PB, PRPB and CAPB. However, negative emotion did not mediate the relationship between WIF and PB. With regard to the moderating role of trait guilt, support was found for PRPB. Theoretical and practical implications, as well as future directions, are discussed
Daily Recovery from Work: The Role of Guilt
Acknowledging the critical role that occupational factors play in employee health, researchers have tried to understand ways to reduce the harmful effects of work on employee health. As the process by which individuals recharge resources that have been depleted, recovery has been recognized as important due to its potential to mitigate the negative effects of work on employee well-being. Although the recovery literature has continued to grow, many questions remain unanswered. The purpose of the present study was to expand our knowledge of recovery by examining situational (job characteristics) and individual (trait guilt) predictors of recovery and investigating psychological attributes of off-job activities. An experience sampling design was used to understand relationships among focal variables at day level. Hypotheses were tested using the data from 99 full-time employees living with a full-time working spouse and at least one dependent. The results suggest that daily job characteristics serve an important role in recovery such that they relate to recovery experiences of psychological detachment and relaxation. However, job characteristics did not have significant relationships with the choice of off-job activities. With regard to subjective experiences of off-job activities, findings demonstrated considerable variance across individuals. Further, psychological attributes of off-job activities were found to relate to recovery experiences although the results were not always consistent with expectation. Next, little support was found for the moderating role of trait guilt in the relationship between job characteristics and off-job activities. Finally, consistent with previous research, recovery experiences related to better well-being outcomes
Biotinylated Cyclooligosaccharides for Paclitaxel Solubilization
The poor water solubility of paclitaxel causes significant problems in producing cancer therapeutic formulations. Here, we aimed to solubilize paclitaxel using biocompatible cyclic carbohydrates. Generally recognized as safe, labeled β-cyclodextrin (β-CD), a cyclic α-1,4-glucan consisting of seven glucoses, was prepared, and bio-sourced cyclosophoraoses (CyS), which are unbranched cyclic β-1,2-glucans with 17–23 glucose units, were purified using various chromatographic methods from Rhizobium leguminosarum cultural broth. For effective targeting, CyS and β-CD were modified with a biotinyl moiety in a reaction of mono-6-amino CyS and mono-6-amino-β-CD with N-hydroxysuccinimide ester of biotinamidohexanoic acid. Interestingly, the aqueous solubility of paclitaxel was enhanced 10.3- and 3.7-fold in the presence of biotinyl CyS and biotinyl β-CD, respectively. These findings suggest that biotin-appended cyclooligosaccharides can be applied to improve the delivery of paclitaxel
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