Impurity incorporation and diffusion from regrowth interfaces in N-polar GaN photocathodes and the impact on quantum efficiency

2021 ◽  
Vol 129 (19) ◽  
pp. 195701
Author(s):  
Emma Rocco ◽  
Isra Mahaboob ◽  
Kasey Hogan ◽  
Vincent Meyers ◽  
Benjamin McEwen ◽  
...  
2017 ◽  
Vol 45 (10) ◽  
pp. 1607-1618 ◽  
Author(s):  
Seung Yun Lee ◽  
Sunho Jung ◽  
Sangdo Oh ◽  
Seong Hoon Park

We proposed that a moderator, others' similarity, would determine the impact of high participation rates of others on an individual's charitable behavior, and aimed to show that this moderator would work through the diffusion of responsibility motive. Participants (N = 152 undergraduate students) completed measures of charitable behavior and diffusion of responsibility, after being assigned to 1 of 2 conditions where a set percentage of other students (manipulated as either similar undergraduate students or dissimilar graduate students) were stated to have already donated to a charitable campaign (high contribution condition = 70% participation, low contribution condition = 30% participation). Our results showed that the high participation rate of others increased an individual's charitable behavior when the others in question were similar to that individual, but not when the others were dissimilar. In addition, the high rate of participation by others increased the diffusion of responsibility motive when the others in question were dissimilar to that individual, leading to a negative effect on that individual's charitable behavior.


2002 ◽  
Vol 29 (5) ◽  
pp. 621 ◽  
Author(s):  
Salvador Nogués ◽  
Leonor Alegre

In the Mediterranean, annual mean precipitation has continuously decreased over the last three years (by ca 36% in Barcelona), and the decrease has been dramatic during the summer (by ca 78 and 64% during July and August, respectively). The impact of increased drought on the photosynthetic capacity of Mediterranean vegetation is currently unknown. In this study, two native Mediterranean plants [rosemary (Rosmarinus officinalis L.) and lavender (Lavandula stoechas L.)] were grown outdoors and subjected to two water regimes (50 mm month–1 during the summer, or no supplementary water at all). Rosemary and lavender plants watered with 50 mm month–1 during the summer had higher relative leaf water content and water potential than non-watered plants. Changes in water status were accompanied by large decreases in parameters of gas exchange [i.e. the light-saturated rate of CO2 assimilation, the maximum velocity of ribulose-1,5-bisphosphate (RuBP) carboxylation by Rubisco and the capacity for RuBP] and of modulated chlorophyll fluorescence (i.e. the relative quantum efficiency of PSII photochemistry and the efficiency of energy capture by open PSII reaction centres) during the summer, but no differences were found in any photosynthetic parameters for leaves subjected to the two water regimes. The drought-induced decreases in the relative quantum efficiency of PSII photochemistry in rosemary and lavender plants were attributable to ‘downregulation’ of electron transport. Photodamage to PSII in the field appeared to be a later effect of drought in these plants. Photorespiration was not a major mechanism protecting the photosynthetic apparatus of these plants from photodamage in the field. After the autumn rainfall, photosynthetic capacity fully recovered. We conclude that rosemary and lavender are well adapted to drought, and that an increase in water deficit is unlikely to have a significant impact on the photosynthetic capacity of leaves.


2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
E. Gaubas ◽  
T. Ceponis ◽  
V. Kalendra ◽  
J. Kusakovskij ◽  
A. Uleckas

Technique for barrier evaluation by measurements of current transients induced by linearly increasing voltage pulse based on analysis of barrier and diffusion capacitance changes is presented. The components of the barrier capacitance charging and generation/recombination currents are discussed. Different situations of the impact of deep center defects on barrier and diffusion capacitance changes are analyzed. Basics of the profiling of layered junction structures using the presented technique are discussed. Instrumentation for implementation of this technique and for investigations of the steady-state bias infra-red illumination and temperature dependent variations of the barrier capacitance charging and generation/recombination currents are described. Applications of this technique for the analysis of barrier quality in solar cells and particle detectors fabricated on silicon material are demonstrated.


2017 ◽  
Vol 49 (11) ◽  
Author(s):  
Christelle Peillon ◽  
Magali Estribeau ◽  
Pierre Magnan ◽  
Alice Pelamatti ◽  
Olivier Saint-Pé ◽  
...  

Author(s):  
Risa A. Brooks

The protests that began in Tunisia in December 2010, and quickly spread across the Arab world, have drawn significant attention to the impact of militaries and coercive institutions on protests and revolutionary movements. The actions of the militaries were a central determinant of the outcomes of the uprisings of 2010–2011. In Tunisia and Egypt the decision by military leaders to abstain from using force on mass protests to suppress them led to the downfall of the countries’ autocrats. In Syria and Bahrain, militaries defended political leaders with brutal force. In Yemen and Libya, militaries fractured, with some units remaining allied to the leader and using force on his behalf and others defecting. In still other states, leaders and militaries were able to forestall the emergence of large, regime-threatening protests.To explain these divergent outcomes, scholars and analysts have looked to a variety of explanatory factors. These focus on the attributes of the militaries involved, their civil-military relations, the size and social composition of the protests, the nature of the regime’s institutions, and the impact of monarchical traditions. These explanations offer many useful insights, but several issues remain under-studied. These include the impact of authoritarian learning and diffusion on protest trajectory. They also include the endogeneity of the protests to the nature of a country’s civil-military relations (i.e., how preexisting patterns of civil-military relations affected the possibility that incipient demonstrations would escalate to mass protests). Scholars also have been understandably captivated by the aforementioned pattern of military defection-loyalty, focusing on explaining that observed difference at the expense of studying other dependent variables. The next generation of scholarship on the uprisings therefore would benefit from efforts to conceptualize and investigate different aspects of variation in military behavior.Overall, the first-generation literature has proved enormously useful and laid the foundation for a much richer understanding of military behavior and reactions to popular uprisings in the Arab world and beyond.


Sign in / Sign up

Export Citation Format

Share Document