989 resultados para GaN Buffer


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Building resilience to climate change in agricultural production can ensure the functioning of agricultural-based livelihoods and reduce their vulnerability to climate change impacts. This paper thus explores how buffer capacity, a characteristic feature of resilience, can be conceptualised and used for assessing the resilience of smallholder agriculture to climate change. It uses the case of conservation agriculture farmers in a Kenyan region and examines how their practices contribute to buffer capacity. Surveys were used to collect data from 41 purposely selected conservation agriculture farmers in the Laikipia region of Kenya. Besides descriptive statistics, factor analysis was used to identify the key dimensions that characterise buffer capacity in the study context. The cluster of practices characterising buffer capacity in conservation agriculture include soil protection, adapted crops, intensification/irrigation, mechanisation and livelihood diversification. Various conservation practices increase buffer capacity, evaluated by farmers in economic, social, ecological and other dimensions. Through conservation agriculture, most farmers improved their productivity and incomes despite drought, improved their environment and social relations. Better-off farmers also reduced their need for labour, but this resulted in lesser income-earning opportunities for the poorer farmers, thus reducing the buffer capacity and resilience of the latter.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This longitudinal study investigated whether cybervictimisation is an additional risk factor for depressive symptoms over and beyond traditional victimisation in adolescents. Furthermore, it explored whether certain coping strategies moderate the impact of cybervictimisation on depressive symptoms. A total of 765 Swiss seventh graders (mean age at time-point 1 (t1) = 13.18 years) reported on the frequency of traditional and cybervictimisation, and of depressive symptoms twice in six months. At time-point 2 (t2) students also completed a questionnaire on coping strategies in response to a hypothetical cyberbullying scenario. Analyses showed that both traditional and cybervictimisation were associated with higher levels of depressive symptoms. Cybervictimisation also predicted increases in depressive symptoms over time. Regarding coping strategies, it was found that helpless reactions were positively associated with depressive symptoms. Moreover, support seeking from peers and family showed a significant buffering effect: cybervictims who recommended seeking close support showed lower levels of depressive symptoms at t2. In contrast, cybervictims recommending assertive coping strategies showed higher levels of depressive symptoms at t2.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this work was to clarify the mechanism taking place in field-enhanced sample injection coupled to sweeping and micellar EKC (FESI-Sweep-MEKC), with the utilization of two acidic high-conductivity buffers (HCBs), phosphoric acid or sodium phosphate buffer, in view of maximizing sensitivity enhancements. Using cationic model compounds in acidic media, a chemometric approach and simulations with SIMUL5 were implemented. Experimental design first enabled to identify the significant factors and their potential interactions. Simulation demonstrates the formation of moving boundaries during sample injection, which originate at the initial sample/HCB and HCB/buffer discontinuities and gradually change the compositions of HCB and BGE. With sodium phosphate buffer, the HCB conductivity increased during the injection, leading to a more efficient preconcentration by staking (about 1.6 times) than with phosphoric acid alone, for which conductivity decreased during injection. For the same injection time at constant voltage, however, a lower amount of analytes was injected with sodium phosphate buffer than with phosphoric acid. Consequently sensitivity enhancements were lower for the whole FESI-Sweep-MEKC process. This is why, in order to maximize sensitivity enhancements, it is proposed to work with sodium phosphate buffer as HCB and to use constant current during sample injection.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Leṿin Ḳipnis

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fil: De Amézola, Gonzalo Alvaro. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fil: De Amézola, Gonzalo Alvaro. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.