Experimental and computational investigation of confined laser-induced breakdown spectroscopy

This paper presents an experimental and computational study on laser-induced breakdown spectroscopy (LIBS) for both unconfined flat surface and confined cavity cases. An integrated LIBS system is employed to acquire the shockwave and plasma plume images. The computational model consists of the mass, momentum, and energy conservation equations, which are necessary to describe shockwave behaviors. The numerical predictions are validated against shadowgraphic images in terms of shockwave expansion and reflection. The three-dimensional (3D) shockwave morphology and velocity fields are displayed and discussed

Joint Power Splitting and Secure Beamforming Design in the Wireless-powered Untrusted Relay Networks

In this work, we maximize the secrecy rate of the wireless-powered untrusted relay network by jointly designing power splitting (PS) ratio and relay beamforming with the proposed global optimal algorithm (GOA) and local optimal algorithm (LOA). Different from the literature, artificial noise (AN) sent by the destination not only degrades the channel condition of the eavesdropper to improve the secrecy rate, but also becomes a new source of energy powering the untrusted relay based on PS. Hence, it is of high economic benefits and efficiency to take advantage of AN compared with the literature. Simulation results show that LOA can achieve satisfactory secrecy rate performance compared with that of GOA, but with less computation time.Comment: Submitted to GlobeCom201

Comparação de características demográficas e clínicas entre crianças e adolescentes com transtorno depressivo maior

OBJECTIVE: To compare clinical characteristics of major depressive disorder symptoms between children and adolescents. METHOD: The subjects were 58 patients of a Child and Adolescent Affective Disorder Clinic consecutively admitted during a six-month period. Children aged 5-9 years old and adolescents from 10-17 years old currently meeting DSM-IV criteria diagnosis of major depressive disorder were chosen. Current MDD diagnosis and depressive psychopathology were assessed by a clinical interview and the Diagnostic Interview for Children and Adolescents-DSM-IV version. The Children’s Depression Rating Scale-Revised Version and the Children Global Assessment Scale rated the severity and global functioning of major depressive disorder. RESULTS: The most common depressive symptoms were: anhedonia (72.4%), depressed mood (72.4%), decreased concentration (62.1%), and irritability (58.6%). The intensity of depressive episodes of this sample ranged from mild to moderate. Fifty percent reported thoughts of death, and 29.3% presented a variety of psychotic symptoms. When compared with children, adolescents reported a significantly more depressed mood (p = 0.043), lower self-esteem (p = 0.002), and had more difficulty concentrating (p = 0.020). Female adolescents had lower self-esteem (p = 0.003), and male adolescents showed more decreased concentration (p = 0.016). CONCLUSION: This study suggests that age and gender differences might influence the clinical presentation of major depressive disorder in children and adolescents. Further studies with larger samples are needed.OBJETIVO: Comparar as características clínicas de transtorno depressivo maior entre crianças e adolescentes. MÉTODO: Amostra constituída de 58 sujeitos admitidos consecutivamente em um serviço especializado em transtornos do humor na infância e adolescência durante um período de 6 meses. Foram considerados crianças sujeitos com idade entre 5 e 9 anos, e adolescentes aqueles com idade entre 10 e 17 anos. Todos os participantes preenchiam diagnóstico de transtorno depressivo maior seguindo os critérios de DSM-IV. O diagnóstico de transtorno depressivo maior e avaliação de aspectos psicopatológicos foram realizados por entrevista clínica direta e aplicação de entrevista de apoio ao diagnóstico. O funcionamento global e a gravidade dos sintomas depressivos foram mensurados através de versões adaptadas de Children’s Depression Rating Scale-Revised Version e Children Global Assessment Scale. RESULTADOS: Os sintomas depressivos mais freqüentes foram: anedonia (72,4%), humor depressivo (72,4%), diminuição de concentração (62,1%) e irritabilidade (58,6%). A intensidade do episódio depressivo dessa amostra variou de leve a moderada. Cinqüenta por cento relataram pensamentos mórbidos e 29,3% apresentaram sintomas psicóticos variados. Quando comparados com crianças, adolescentes apresentaram significativamente mais humor depressivo (p = 0,043), baixa auto-estima (p = 0,002) e mais dificuldade de concentração (p = 0,020). As adolescentes femininas tinham mais baixa auto-estima (p = 0,003) e os masculinos mostraram mais diminuição de concentração (p = 0,016). CONCLUSÃO: Esse estudo sugere que idade e gênero poderiam influenciar na apresentação clínica de transtorno depressivo maior em crianças e adolescentes. Estudos com amostra mais representativa serão necessários