Search results for "characterization"

SAMs Based Device Fabrication and Characterization

2015

Despite the high potentiality of SAMs for spintronics, not many results exist at the moment in the literature. This lack of results is mainly due to the difficulty to fabricate the devices. The two main technological problems consist in the ferromagnetic electrodes compatibility issues with wet chemistry and the short-circuit formation during top electrode deposition. A part of this thesis has been committed to overcome these technological problems. This chapter will explain the steps that led us to the development of SAMs-based magnetic tunnel nanojunctions.

Thermal conductivity measurement of insulating innovative building materials by hot plate and heat flow meter devices: A Round Robin Test

2019

Abstract The characterization of thermal insulation properties of construction materials represents a fundamental step on the building insulation assessment. In recent years innovative materials have been introduced in the market to fulfill the continuously growing requirements of energy saving and sustainability, and their performance is not so reliable and mature as it happens for traditional insulators. The work presents a Round Robin Test realised among six European laboratories hosting hot plates devices to measure the thermal conductivity of four different materials: aerogel, vacuum insulation panels, polystyrene and birch wood fibre insulation boards. After the definition of the comm…

Īpašvārdi Kena Kizīja romānā „Kāds pārlaidās pār dzeguzes ligzdu“

2018

Šajā bakalaura darbā tiek pētīti nosaukšanas strateģias Kena Kizijā romānā „Kāds pārlaidās pār dzeguzes ligzdu” (1962). Šī darbā mērķis ir noskaidrot, kā tēlu vārdu izveidošana stratēģijas, iespējami varētu ietekmēt uz kopējo personāža tēlu. Lai veiktu analīzi, tika noteikts teorētiskais pamats. Šī pētījuma empīriskās daļas metode ir teksta analīze. Analīzes korpusā tika izpetīti 14 varoņu vārdi, kuri tika izvēlēti saskaņā ar to nozīmi sižetā attistībā. Turklāt, tika izpetīt iespējami vārdu veidošanas strateģijas, ka arī analīzi izteiksmīgos līdzekļus izvēlētos vārdos. Analīzes rezultāti parādīja, ka tēlu vārdu izveidošanas stratēģijas, kā tēlu raksturojumu dāļa papildinā un izveido neaizmi…

Gas–solid chromatographic separation of hydrogen isotopes: a comparison between two palladium bearing materials – alumina and kieselguhr

1998

The separation of hydrogen isotopes (H, D, T) is performed by displacement gas chromatography on palladium. A large isotopic effect is associated with the reversible adsorption of hydrogen by palladium. Two Pd support materials have been compared: alpha-alumina and kieselguhr. The study includes a physicochemical characterization and a set of functional tests. The Van Deemter model gives a fairly good analysis of the process but to get more information, thermoregulated separations are needed. For both supports, palladium is impregnated as small dispersed particles in the 0.1 to 0.3 μm range diameter. For the same palladium loading, alumina is more efficient than kieselguhr.

Prediction of Peak Shape and Characterization of Column Performance in Liquid Chromatography as a Function of Flow Rate

2015

Traditionally, column performance in liquid chromatography has been studied using information from the elution of probe compounds at different flow rates through van Deemter plots, which relate the column plate height to the linear mobile phase velocity. A more recent approach to characterize columns is the representation of the peak widths (or the right and left peak half-widths) for a set of compounds versus their retention times, which, for isocratic elution, give rise to almost linear plots. In previous work, these plots have been shown to facilitate the prediction of peak profiles (width and asymmetry) with optimization purposes. In this work, a detailed study on the dependence of the …

Low-temperature molecular layer deposition using monifunctional aromatic precursors and ozone-based ring-opening reactions

2017

Molecular layer deposition (MLD) is an increasingly used deposition technique for producing thin coatings consisting of purely organic or hybrid inorganic-organic materials. When organic materials are prepared, low deposition temperatures are often required to avoid decomposition, thus causing problems with low vapor pressure precursors. Monofunctional compounds have higher vapor pressures than traditional bi- or trifunctional MLD precursors, but do not offer the required functional groups for continuing the MLD growth in subsequent deposition cycles. In this study, we have used high vapor pressure monofunctional aromatic precursors in combination with ozone-triggered ring-opening reactions…

Evaluation of the variations in chemical and microbiological properties of the sourdoughs produced with selected lactic acid bacteria strains during …

2022

This research aimed to analyze variations in chemical properties, microbiological characteristics and generated volatile organic compounds (VOCs) profile during sourdough fermentation. Sourdoughs were collected from different cities in Turkey at two different times and lactic acid bacteria (LAB) in the samples were identified with culture-independent and culture-dependent molecular methods. According to culture-dependent methodology, thirteen LAB species were identified. Lactobacillus spp. were identified as the major group according to MiSeq Illumina analysis. Technological potential of commonly isolated LAB species was evaluated. Due to high frequency of isolation, Fructilactobacillus san…

Hot-spot detection and characterization of strombolian activity from MODIS infrared data

2014

Identifying and characterizing strombolian activity from space is a challenging task for satellite-based infrared systems. Stromboli volcano is a natural laboratory that offers a unique opportunity for refining thermal remote-sensing applications that involve transient phenomena and small to moderate hot-spots. A new simple and fast algorithm gave us the opportunity to revisit the MODIS-derived thermal output at Stromboli volcano over the last 13 years. The new algorithm includes both night-time and daytime data and shows high performance with the detection of small-amplitude thermal anomalies (  1000 MW). The ...

The wall paintings of the Roman Villa at Piazza Armerina in Sicily

2010

Warm white LED light by frequency down-conversion of mixed yellow and red Lumogen®

2013

This work reports on the benefits and promising opportunities offered by white LED hybrid technology, based on a mixing perylene-based dyes in order to obtain a warm white light for frequency-down conversion. In a standard Ce:YAG-based white LED, the white light appears cold due to the weakness of red wavelength components in the emission spectrum. In order to obtain a warmer white, one possible solution is to add a red phosphor to the yellow one to move the chromatic coordinates properly, though the luminous efficiency drastically decreases due to the increased light absorption of the coating layer. It is generally believed that the low efficiency of warm white LEDs is the main issue today…