2,431 research outputs found

    Analisis Perilaku Agresif Siswa Ditinjau dari Aspek Tingkat Pendidikan, Ekonomi, Pekerjaan Orang Tua Siswa Dismpn 4 Pekanbaru

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    At school, most teens showed a negative behavior, one of which is aggressive behavior, which is an act of deliberate on other people, causing physical and psychological pain on other people. While the things that affect aggressive behavior can come from parents, among others, the level of education, the economy and the job of parents. The objectives of this research are: 1) to obtain an image of aggressive behavior of students in terms of parental education level, 2) to obtain an image of aggressive behavior of students in terms of parent economy, and 3) to obtain a picture of aggressive behavior of students in terms of parent work. The population of this study is all students of class VIII in SMPN 4 Pekanbaru consisting of 10 classes. A sample of 144 students. This research is a quantitative study with descriptive approach surve. Instrument data collection using a questionnaire which is then analyzed by grouping data and calculating the percentage. the results of this research are: 1) The dominant student behavior is very aggressive of his parents with high education (7.6%). The student's aggressive behavior is highly educated (64.6%). While the behavior of students who are not aggressive parents are highly educated (0.7%). 2) dominant student behavior is very aggressive parent at middle economic level equal to (6.2%). The aggressive student behavior of his parents is at the middle economic level of (39.6%). While the student's non-aggressive behavior is at the middle economic level of (0.7%). 3). The dominant student behavior is very aggressive his parents work as private employees (6.9%). Then the aggressive student behavior of his parents worked as civil servants (18.1%). While the behavior of students who are not aggressive have parents who work as entrepreneurs (11.8%)

    Plasma Membrane H+-ATPase in Maize Roots Induced for NO3- Uptake

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    Failure Physics and Reliability of GaN-Based HEMTs for Microwave and Millimeter-Wave Applications: A Review of Consolidated Data and Recent Results

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    Herein, the results are reviewed concerning reliability of high-electron mobility transistors (HEMTs) based on GaN, which currently represent the technology of choice for high-efficiency microwave and millimeter-wave power amplifiers. Several failure mechanisms of these devices are extensively studied, including converse piezoelectric effects, formation of conductive percolation paths at the edge of gate toward the drain, surface oxidation of GaN, time-dependent breakdown of GaN buffer, and of field-plate dielectric. For GaN HEMTs with scaled gate length, the simultaneous control of short-channel effects, deep-level dispersion, and hot-electron-induced degradation requires a careful optimization of epitaxial material quality and device design

    Dynamic Behavior of Threshold Voltage and ID-VDS Kink in AlGaN/GaN HEMTs Due to Poole-Frenkel Effect

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    The kink effect in field-effect transistors (FETs) consists in a sudden increase in drain current, during a drain voltage sweep and leading to a higher drain current saturation value. We report new experimental data concerning the dynamic behavior of the "kink" in AlGaN/GaN HEMTs and correlate them with deep levels. The results demonstrate the role of the Poole-Frenkel effect in determining the occurrence of the kink and identify the experimental conditions that make it observable

    Non-Fermi liquid behavior of SrRuO_3 -- evidence from infrared conductivity

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    The reflectivity of the itinerant ferromagnet SrRuO_3 has been measured between 50 and 25,000 cm-1 at temperatures ranging from 40 to 300 K, and used to obtain conductivity, scattering rate, and effective mass as a function of frequency and temperature. We find that at low temperatures the conductivity falls unusually slowly as a function of frequency (proportional to \omega^{-1/2}), and at high temperatures it even appears to increase as a function of frequency in the far-infrared limit. The data suggest that the charge dynamics of SrRuO_3 are substantially different from those of Fermi-liquid metals.Comment: 4 pages, 3 postscript figure

    degradation of gan on gan vertical diodes submitted to high current stress

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    Abstract GaN-on-GaN vertical devices are expected to find wide application in power electronics, thanks to the high current densities, the low on-resistance and the high breakdown voltage. So far, only few papers on the reliability of GaN-on-GaN vertical devices have been published in the literature. This paper investigates the degradation of GaN-on-GaN pn diodes submitted to stress at high current density. The study was carried out by means of electrical characterization and electroluminescence (EL) measurements. We demonstrate that: (i) when submitted to stress at high current density, the devices show significant changes in the electrical characteristics: an increase in on-resistance/turn-on voltage, an increase in the generation/recombination components, the creation of shunt-paths. (ii) the increase in on-resistance is strongly correlated to the decrease in the EL signal emitted by the diodes. (iii) the degradation kinetics have a square-root dependence on time, indicative of a diffusion process. The results are interpreted by considering that stress induces a diffusion of hydrogen from the highly-p-type doped surface towards the pn junction. This results in a decrease in hole concentration, due to the creation of Mg H bonds, and in a lower hole injection. As a consequence, on-resistance increases while EL signal shows a correlated decrease

    Bases teóricas para definição de indicadores de sustentabilidade para cultivo de trigo no Brasil.

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    Coexistence of ferromagnetism and superconductivity

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    A comprehensive theory is developed that describes the coexistence of p-wave, spin-triplet superconductivity and itinerant ferromagnetism. It is shown how to use field-theoretic techniques to derive both conventional strong-coupling theory, and analogous gap equations for superconductivity induced by magnetic fluctuations. It is then shown and discussed in detail that the magnetic fluctuations are generically stronger on the ferromagnetic side of the magnetic phase boundary, which substantially enhances the superconducting critical temperature in the ferromagnetic phase over that in the paramagnetic one. The resulting phase diagram is compared with the experimental observations in UGe_2 and ZrZn_2.Comment: 16 pp., REVTeX, 6 eps figs; final version as publishe

    Threatened and extinct amphibians and reptiles in Italian natural history collections are useful conservation tools

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    Natural history museums are irreplaceable tools to study and preserve the biological diversity around the globe and among the primary actors in the recognition of species and the logical repositories for their type specimens. In this paper we surveyed the consistency of the preserved specimens of amphibians and reptiles housed in the major Italian scientific collections, and verified the presence of threatened species according to the IUCN Red List, includ-ing the Extinct (EX), Extinct in the Wild (EW), Critically Endangered (CR), Endangered (EN), and Vulnerable (VU) categories. Altogether, we analyzed 39 Italian zoological collections. We confirmed the presence of one extinct reptile (Chioninia coctei) and five extinct or extinct in the wild amphibian species (Atelopus longirostris, Nectophrynoides asperginis, Pseudophilautus leucorhinus, P. nasutus, and P. variabilis). Seven CR amphibians, fourteen CR reptile species and the extinct skink C. coctei are shared by more than one institution. Museums which host the highest number of threatened and extinct amphibian species are respectively Turin (17 CR and 1 EX), Florence (13 CR and 1 EX), and Trento (15 CR and 1 EW), while for reptiles the richest museums are those from Genoa (15 CR and 1 EX), Florence (11 CR and 1 EX), and Pisa (7 CR). Finally, we discussed the utility of natural history museums and the strategies to follow for the implementation of their functionality. © Firenze University Press
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