Search results for "Iode"
showing 10 items of 1284 documents
Charge Transport Mechanisms in Heavy-Ion Driven Leakage Current in Silicon Carbide Schottky Power Diodes
2016
Under heavy-ion exposure at sufficiently high reverse bias voltages silicon carbide (SiC) Schottky diodes are observed to exhibit gradual increases in leakage current with increasing ion fluence. Heavy-ion exposure alters the overall reverse current-voltage characteristics of these diodes, leaving the forward characteristics practically unchanged. This paper discusses the charge transport mechanisms in the heavy-ion damaged SiC Schottky diodes. A macro model, describing the reverse current-voltage characteristics in the degraded SiC Schottky diodes is proposed. peerReviewed
Single Event Burnout of SiC Junction Barrier Schottky Diode High-Voltage Power Devices
2018
Ion-induced degradation and catastrophic failures in high-voltage SiC Junction Barrier Schottky (JBS) power diodes are investigated. Experimental results agree with earlier data showing discrete jumps in leakage current for individual ions, and show that the boundary between leakage current degradation and a single-event-burnout-like effect is a strong function of LET and reverse bias. TCAD simulations show high localized electric fields under the Schottky junction, and high temperatures generated directly under the Schottky contact, consistent with the hypothesis that the ion energy causes eutectic-like intermixture at the metal- semiconductor interface or localized melting of the silicon …
Fermentējamo cukuru iegūšana no lignocelulozes atkritumiem biodegvielas ražošanai
2016
Bakalaura darba mērķis ir izpētīt pirmapstrādes efektivitāti un tās nepieciešamību pirms biomasas enzimātikskās hidrolīzes. Mērķa sasniegšanai tika izvirzīti uzdevumi: veikt enzimātisko hidrolīzi uz substrātu kas tika a) pirmapstrādāts tikai mehāniski, un b) kas tika pirmapstrādāts mehāniski un ar skābi. Rezultāti tiek novērtēti pēc izdalīto cukuru daudzuma. Iegūtie rezultāti parāda, ka efektīvai fermentējamo cukuru iegūšanai no biomasas papildus hidrolīzei jāveic pirmapstrādi. No 1 g siena bija iespējams iegūt 0.46 g/g (115% no literatūras minēta teorētiskā maksimuma) glikozes un 0.38 g/g (81% no literatūras minēta teorētiskā maksimuma) no 1 g salmu substrāta. Fermentējot iegūtos cukurus, …
Fate of organic pollutants after sewage sludge spreading on agricultural soils: a 30-years field-scale recording
2006
Le DOI mentionné dans l'article 10.2166/WPT.2007.008 ne fonctionne pas; International audience; Toxic organic compounds, such as the surfactants linear alkylbenzene sulfonates (LAS) and nonylphenol polyethoxylates (NPE), Polycyclic aromatic hydrocarbons (PAH) and residues derived from plastics (PAE-phthalates) end up in sewage sludge. In order to evaluate and quantify the potential environmental risks associated with the xenobiotic introduction into biological life cycle, the EU BIOWASTE project (QLK5-CT-2002-01138) devotes one task to the study of the fate of xenobiotic in a sandy soil after sludge spreading on a 30-year field-scale record experiment. Experimental maize crop fields from Bo…
Biodegradation of organophosphorus pesticides by soil bacteria.
2009
A number of studies in the 1980s and 1990s showed that crop-protection products, applied to drained fields, could move downwards through the soil profile and to the groundwater. Organophosphorus insecticides (OPs) are used all over the world for crop protection, for other agricultural practices such as sheep dipping and, in aquaculture, for the control of sea lice. Ops besides showing a specific neurotoxicity and have also been related to various modern diseases, including Creutzfeldt–Jakob (CJD) and the Gulf War syndrome. Although OPs are less persistent than Organoclorine pesticides (OCs), they still constitute an environmental risks thus increasing the social concern about their levels i…
Influence of Calcium Carbonate Nanoparticles on the Soil Burial Degradation of Polybutyleneadipate-Co-Butylenetherephthalate Films.
2022
A polybutyleneadipate-co-butylenetherephthalate (PBAT) sample, commercially known as Ecoflex®, was processed via melt extrusion with CaCO3 nanoparticles coated with a hydrophobic coating. Blown films of PBAT and two composites with nanofiller (2% and 5%wt) were prepared and degradation tests in soil at 30 °C up to 180 days were carried out with weight loss measurements. Furthermore, biodegradation test according to ISO 14851 was carried out at 30 °C. The effect of CaCO3 on soil burial degradation was assessed by surface wettability and SEM. ATR-FTIR and XPS analyses highlighted chemical modifications induced by soil degradation. CaCO3 nanoparticles decreased surface wettability …
Mental health profiles of Finnish adolescents before and after the peak of the COVID-19 pandemic
2023
Abstract Background The COVID-19 pandemic has had implications for adolescents’ interpersonal relationships, communication patterns, education, recreational activities and well-being. An understanding of the impact of the pandemic on their mental health is crucial in measures to promote the post-pandemic recovery. Using a person-centered approach, the current study aimed to identify mental health profiles in two cross-sectional samples of Finnish adolescents before and after the peak of the pandemic, and to examine how socio-demographic and psychosocial factors, academic expectations, health literacy, and self-rated health are associated with the emerging profiles. Methods and findings Surv…
Private health insurance in the universal public healthcare system: The role of healthcare provision in Finland
2023
Voluntary private health insurance (VPHI) has gained popularity in universal public healthcare systems. We studied how the local provision of healthcare services correlated with VPHI take-up in Finland. Nationwide register data from a Finnish insurance company was aggregated to the local level and augmented with high-quality data on public and private primary care providers’ geographical closeness and fees. We found that the sociodemographic characteristics explained the VPHI take-up more than public or private healthcare provision. The VPHI take-up was negatively associated with distance to the nearest private clinic, while the associations with distance to public health stations were stat…
Ikääntyneiden kotona asuvien henkilöiden tyydyttymättömät osallisuuden tarpeet
2015
Ikääntyneiden ihmisten kuuluu saada osallistua yhteiskuntaan. Osallisuutta pidetään aktiivisen ikääntymisen yhtenä piirteenä. Jos ikääntynyt on kykenemätön osallistumaan haluamaansa toimintaan, muodostuu tästä tyydyttymätön osallisuuden tarve. Tutkielman tarkoituksena oli selvittää tyydyttymättömään osallisuuden ja ulkoilun tarpeeseen yhteydessä olevia tekijöitä yli 65 – vuotiailla kotona asuvilla henkilöillä. Tässä tutkimuksessa analysoitiin vuonna 2009-2011 kerättyä vapaaehtoistyö, ulkoliikunta ja vanhusten hyvinvointi (VAU)- tutkimushankkeen alkumittausaineistoa. Tutkimukseen osallistui 120 67-92 – vuotiasta miestä (n= 12) ja naista (n=108). Tyydyttymätöntä ulkoilun sekä osallisuuden tar…