Search results for "Tempera"
showing 10 items of 4201 documents
On the degree of binder activity of reclaimed asphalt and degree of blending with recycling agents
2020
It is common practice to assume full blending of the aged binder of reclaimed asphalt (RA) within the design of new asphalt mixtures. Although being practical, this assumption has often led designers to asphalt mixtures lacking binder. Hence, going towards recycled asphalt mixtures (RAM) there is a need to have a better understanding of the blending phenomena, to have a general agreement on terminology and finally adapting RA classification and mix design procedures accordingly. This manuscript aims at being both a reference and stimulus for the scientific community to work in this direction and on this basis provides a nomenclature and a theoretical framework of the blending phenomena. The…
LU FMOF Optometrijas un redzes zinātnes nodaļas un Latvijas optometristu un optiķu asociācijas konferenču referātu tēzes
2022
Tēzes no LU 80.Starptautiskās zinātniskās konferences Cilvēka fizioloģijas un uztveres sēdes un LU Optometrijas un redzes zinātnes nodaļas un LOOA kopīgās klīniski praktiskās konferences Rīgā, 2022. gada 11. un 13. februārī
Análisis de técnicas de “aggregation”/“disaggregation” aplicadas a imágenes satélite para la estimación de parámetros térmicos superficiales a difere…
2023
Las aplicaciones que implican la observación de la superficie terrestre desde plataformas satélites a escala inferior a la regional, como por ejemplo, el caso del seguimiento de cultivos, requieren de una mayor disponibilidad de información térmica, en particular de la temperatura de la superficie terrestre (LST), con resoluciones espaciales apropiadas para un alcance local. Por ello, numerosos autores han propuesto y desarrollado métodos para extraer la LST a nivel “subpíxel”, mediante el empleo de productos complementarios de teledetección, con resultados adecuados para su uso en resoluciones superiores. La mayoría de estos métodos se basan en la correlación entre índices de vegetación, c…
Demo 161. Resistencia eléctrica de un metal y de un semimetal. Bombillas de filamento incandescente: tungsteno vs. carbono
2021
Se presenta una demostración de aula que muestra que la curva voltaje-intensidad del filamento de una bombilla incandescente es no lineal. Para un filamento de tungsteno se observa que la resistencia eléctrica aumenta con la temperatura del filamento, la cual aumenta con la potencia eléctrica consumida, pues esta se disipa por radiación según la ley de Stefan. Para un filamento de carbono se observa que la resistencia eléctrica disminuye con la temperatura, evidenciando así que no es un metal (sino un semimetal). A classroom demonstration is presented showing that the voltage-intensity curve of the filament of an incandescent light bulb is non-linear. For a tungsten filament, it is observed…
Low-temperature Molecular Layer Deposition Using Monofunctional 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…
Photoluminescent Detection of Human T-Lymphoblastic Cells by ZnO Nanorods.
2020
The precise detection of cancer cells currently remains a global challenge. One-dimensional (1D) semiconductor nanostructures (e.g., ZnO nanorods) have attracted attention due to their potential use in cancer biosensors. In the current study, it was demonstrated that the possibility of a photoluminescent detection of human leukemic T-cells by using a zinc oxide nanorods (ZnO NRs) platform. Monoclonal antibodies (MABs) anti-CD5 against a cluster of differentiation (CD) proteins on the pathologic cell surface have been used as a bioselective layer on the ZnO surface. The optimal concentration of the protein anti-CD5 to form an effective bioselective layer on the ZnO NRs surface was selected. …
Room temperature synthesis of lanthanum phosphates with controlled nanotexture as host for Ln(III) through the Epoxide Route
2022
AbstractHerein, the Epoxide Route, a one-pot room temperature alkalinization method based on the reaction between a nucleophile and an epoxide, has been employed to synthesize LaPO4 in the form of a Rhabdophane phase. The intrinsic features of this synthetic approach allow the reaction to be followed by pH monitoring, making possible the identification of the different precipitation steps involved in the formation of the solid. Once demonstrated the effectiveness of this chemical methodology, the size and shape of the LaPO4 particles were controlled by varying the identity and proportion of the organic co-solvents employed to perform the reaction. By these means, crystalline particles with …
Defying Stereotypes with Nanodiamonds: Stable Primary Diamondoid Phosphines
2016
International audience; Direct unequal C-H bond difunctionalization of phosphorylated diamantane was achieved in high yield from the corresponding phosphonates. Reduction of the functionalized phosphonates provides access to novel primary and secondary alkyl/aryl diamantane phosphines. The prepared primary diamantyl phosphines are quite air stable compared to their adamantyl and especially alkyl or aryl analogues. This finding is corroborated by comparing the singly occupied molecular orbital energy levels of the corresponding phosphine radical cations obtained by density functional theory computations.
Rotējošu pastāvīgo magnētu izmantošana šķidra metāla temperatūras homogenizācijai
2022
Darba pētījums ir par šķidra metāla temperatūras homogenizāciju, izmantojot plūsmu, ko rada rotējoši pastāvīgo magnētu dipoli. Darba mērķis ir izpētīt efektīvāko magnēta pozīciju atkarībā no leņķa priekš šķidra metāla temperatūras homogenizācijas. Darbā veikts literatūras apskats, novērtēti galvenie plūsmas parametri, izveidota eksperimentālā iekārta, izpētīta siltuma pārnese metālā un mērīta temperatūra laikā, savstarpēji salīdzināti iegūtie rezultāti t.sk. ar skaitliskajiem aprēķiniem. Parādīts, ka pastāvīgos magnētus var izmantot arī industrijā. Darbā tiek izmantota jauna metāla temperatūras sadalījuma mērīšanas metode, izmantojot infrasarkano starojuma kameru. Demonstrēts, ka ir būtiska…
Environmental factors influencing the distribution and prevalence of Schistosoma haematobium in school attenders of ILembe and uThungulu Health Distr…
2017
Schistosoma haematobium infection is reported to facilitate the development of urogenital diseases. Its symptoms include haematuria, dysuria and tiredness, and it may cause cognitive decline in children. The prevalence of S. haematobium infection needs to be known in endemic areas and a mass treatment programme against the disease implemented. The aim of this study was to investigate the prevalence and intensity of S. haematobium infection in ILembe and uThungulu health districts, using the major symptom, haematuria, as an indicator. A total of 6 265 urine samples, from 96 rural schools, was collected for analysis using dipsticks. The prevalence of haematuria in the ILembe health district w…