Search results for "n-type"
showing 10 items of 66 documents
Sliding Mode Control of Quadratic Boost Converters Based on Min-Type Control Strategy
2023
The paper deals with the control of a quadratic boost converter supplied by low-voltage energy sources, such as photovoltaic panels, fuel cells, or batteries. The control scheme consists of two control loops. A min-type controller governs the inner loop to force the current state of the nominal model to converge in a neighborhood of the equilibrium state. The external loop processes the output tracking error using an integrator, and it allows reconfiguring the converter's working point by changing the equilibrium state given in the input to the internal loop. This configuration assures both zero tracking error of the output voltage and robustness against load and input voltage variations an…
Guest Induced Strong Cooperative One- and Two-Step Spin Transitions in Highly Porous Iron(II) Hofmann-Type Metal-Organic Frameworks.
2017
[EN] The synthesis, crystal structure, magnetic, calorimetric, and Mo¿ ssbauer studies of a series of new Hofmann-type spin crossover (SCO) metal¿organic frameworks (MOFs) is reported. The new SCO-MOFs arise from self-assembly of FeII, bis(4-pyridyl)butadiyne (bpb), and [Ag(CN)2] ¿ or [MII(CN)4] 2¿ (MII = Ni, Pd). Interpenetration of four identical 3D networks with ¿-Po topology are obtained for {Fe(bpb)[AgI (CN)2]2} due to the length of the rod-like bismonodentate bpb and [Ag(CN)2] ¿ ligands. The four networks are tightly packed and organized in two subsets orthogonally interpenetrated, while the networks in each subset display parallel interpenetration. This nonporous material undergoes a…
Prognosis of migraine headaches in adolescents: a 10-year follow-up study.
2006
Objective: To determine the long-term outcome of migraine headaches in adolescents and to identify possible predictors of prognosis. Methods: Fifty-five of 80 subjects with migraine headaches (ages 11 to 14 years), who attended the baseline examination of a population-based study conducted in southern Italy in 1989, were eligible for follow-up in 1999. All interviews and examinations were conducted by neurologists, and migraine diagnoses were based on the International Headache Society (IHS) criteria. The association between possible prognostic factors and the long-term persistence of migraine headaches was explored using logistic regression analysis. Results: Of 55 subjects with migraine h…
Survey on treatments for primary headaches in 13 specialized juvenile Headache Centers: The first multicenter Italian study
2017
Abstract Aim The purpose of this retrospective multicenter study was to evaluate the use and the self-perceived efficacy and tolerability of pharmacological and non-pharmacological treatments in children and adolescents with primary headaches. Methods Study of a cohort of children and adolescents diagnosed with primary headache, consecutively referred to 13 juvenile Italian Headache Centers. An ad hoc questionnaire was used for clinical data collection. Results Among 706 patients with primary headaches included in the study, 637 cases with a single type of headache (migraine 76% – with and without aura in 10% and 67% respectively; tension-type headache 24%) were selected (mean age at clinic…
Prevalence of primary headaches in Italian elderly: Preliminary data from the Zabút Aging Project
2003
We describe preliminary 1-year prevalence data of recurrent migraine headache (MH), tension-type headache (TTH), and other headaches (OH) in a rural elderly population. A door-to-door two-phase survey was conducted on all elderly (or=65 years) residents of a rural village in southern Italy. Participants underwent a two-phase screening including a validated semi-structured questionnaire for headaches based on the International Headache Society criteria, and a neurological evaluation. Recurrent headache was defined as 3 or more attacks within the past 12 months. Out of 1031 participants evaluated, 225 (21.8%) suffered from recurrent headaches. One-year prevalence rates for headaches were resp…
Osmophobia as an early marker of migraine: a follow-up study in juvenile patients.
2012
Background: Osmophobia is frequent in children with migraine (20–35%) but can also occur in up to 14% of cases with tension-type headache (TTH). So far, the prognostic role of this symptom in children with primary headaches has never been evaluated. Methods: A longitudinal prospective study was conducted on 90 young patients with TTH (37 with osmophobia, 53 without osmophobia). We evaluated whether osmophobia could predict the diagnosis transformation from TTH to migraine after a 3-year follow-up. Results and Discussion: In our cases the rate of diagnosis change was significantly greater in cases with osmophobia (62%) than in those without (23%). Osmophobia persisted at a 3-year follow-up …
A comparative study of photocatalytically active nanocrystalline tetragonal T zyrcon- type and monoclinic scheelite-type bismuth vanadate
2018
The authors from Vinča Institute of Nuclear Sciences acknowledge the financial support of the Ministry of Education, Science and Technological Development of the Republic of Serbia (Project no: 172056 ). The work of K. Smits was supported by Latvian National Research Program IMIS2 (Grant no. 302/2012 ).
PEDOT thin films with n-type thermopower
2019
peer-reviewed Synthesis of n-type organic semiconductors is challenging as reduced states are difficult to obtain due to their instability in air. Here, we report tailoring of semiconducting behavior through control of surfactant concentration during synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles. Nanoparticles were synthesized by mini-emulsion polymerization, where stable suspensions were used to produce polymer films by a simple casting technique on polyethylene terephthalate (PET) substrates. Electrical conductivity and Seebeck coefficients were measured as a function of surfactant concentration. It was found that conductivity decreases three orders of magnitude as s…
Epitaxial Thin-Film vs Single Crystal Growth of 2D Hofmann-Type Iron(II) Materials: A Comparative Assessment of their Bi-Stable Spin Crossover Proper…
2020
Integration of the ON-OFF cooperative spin crossover (SCO) properties of FeII coordination polymers as components of electronic and/or spintronic devices is currently an area of great interest for potential applications. This requires the selection and growth of thin films of the appropriate material onto selected substrates. In this context, two new series of cooperative SCO two-dimensional FeII coordination polymers of the Hofmann-type formulated {FeII(Pym)2[MII(CN)4]·xH2O}n and {FeII(Isoq)2[MII(CN)4]}n (Pym = pyrimidine, Isoq = isoquinoline; MII = Ni, Pd, Pt) have been synthesized, characterized, and the corresponding Pt derivatives selected for fabrication of thin films by liquid-phase …
Supramolecular Order of Solution-Processed Perylenediimide Thin Films
2011
N,N ′ -1 H ,1 H -perfl uorobutyl dicyanoperylenecarboxydiimide (PDIF-CN 2 ), a soluble and air stable n-type molecule, undergoes signifi cant reorganization upon thermal annealing after solution deposition on several substrates with different surface energies. Interestingly, this system exhibits an exceptional edge-on orientation regardless of the substrate chemistry. This preferential orientation is rationalized in terms of strong intermolecular interactions between the PDIF-CN 2 molecules. The presence of a pronounced π– π stacking is confi rmed by combining near-edge X-ray absorption fi ne structure spectroscopy (NEXAFS), dynamic scanning force microscopy (SFM) and surface energy measure…