Search results for "element"
showing 10 items of 13601 documents
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. …
Rotaļas elementu izmantošana runas attīstības veicināšanā 3-4 gadu veciem bērniem
2022
Bakalaura darba tēma: Rotaļas elementu izmantošana runas attīstības veicināšanā 3-4 gadu veciem bērniem. Bakalaura darba mērķis ir analizēt rotaļu elementu izmantošanas iespējas runas attstības procesā 3-4gadu veciem bērniem. Mūѕdiеnu vесāki аktīvu rοtаļāšаnοѕ аr bērnu aizstāj ar tеhnοlοģiјām dаtοriеm, tālruņiеm, kаѕ раlīdz nοdаrbināt bērnu, tаču vаi tаѕ ѕеkmē bērnu vаlοdаѕ аttīѕtību? Rοtаļāšаnāѕ ir ѕvаrīgа јаu nο аgra bērnu vесumа, јο rοtаļа ir tā, kаѕ раlīdz аttīѕtīt dаžādаѕ bērnа рѕihiѕkāѕ funkсiјаѕ– аtmiņu, uzmаnību, runu, tēlаinο un lοģiѕkο dοmāšаnu. Рirmѕѕkοlаѕ iеѕtāžu uzdеvumѕ ir ѕtimulēt bērnu аttīѕtību gаn gаrīgi, gаn fiziѕki, un rοtаļа tаm ir liеliѕkѕ раlīgѕ, tаču diеmžēl māјāѕ tа…
Ķīmisko elementu saturs dažādos rīsos
2018
Ķīmisko elementu saturs dažādos rīsos. Lāma E., zinātniskais vadītājs Dr. ķīm., doc. Rudoviča V. Bakalaura darbs, 43 lappuses, 13 attēli, 6 tabulas, 34 literatūras avoti, 10 pielikumi. Latviešu valodā. Pētījumā ķīmisko elementu (Zn, Mn, Cu, Se, Sr, Ba, Cd, As, Pb) saturs rīsu paraugos tika noteikts ar induktīvi saistītās plazmas masspektrometrijas metodi, liesmas un elektrotermālās atomabsorbciometrijas analīzes metodēm. Tika izvērtēta elementu masas daļa rīsu paraugos atkarībā no to klasifikācijas, apstrādes veida, ievākšanas valsts.
Improving the Downwind Sail Design Process by Means of a Novel FSI Approach
2021
The process of designing a sail can be a challenging task because of the difficulties in predicting the real aerodynamic performance. This is especially true in the case of downwind sails, where the evaluation of the real shapes and aerodynamic forces can be very complex because of turbulent and detached flows and the high-deformable behavior of structures. Of course, numerical methods are very useful and reliable tools to investigate sail performances, and their use, also as a result of the exponential growth of computational resources at a very low cost, is spreading more and more, even in not highly competitive fields. This paper presents a new methodology to support sail designers in ev…
Controlling the crystal growth of potassium iodide with a 1,1'-bis(pyridin-4-ylmethyl)-2,2'-biimidazole ligand (L) – formation of a linear [K4I4L4]n …
2018
The crystal growth of potassium iodide was controlled by using the neutral organic 1,1′-bis(pyridin-4-ylmethyl)-2,2′-biimidazole (L) ligand as a modifier. The selected modifier allows the preservation of original cubic [K4I4] units and their arrangement into a linear ligand-supported 1D chain. The supported [K4I4] cubes are only slightly distorted compared to the cubes found in pure KI salt. The N–K binding of the ligand to the KI salt, as well as weak I⋯H, N⋯H, and N⋯I interactions, stabilizes the structure to create a unique 1D polymer of neutral potassium iodide ionic salt inside the [K4I4L4]n complex.
Method development for determination and recovery of rare earth elements from industrial fly ash
2014
Rare earth elements (REE) are important in numerous high technology applications and in addition their supply risk is high, which gives rise to studying new sources for rare earth elements. Rare earth element concentrations in industrial fly ash samples collected from Finnish power plants, using a mixture of peat and biomass as a fuel, have been determined. Two sample pre-treatment methods, ultrasound- and microwave-assisted acid digestions, have been applied to fly ash samples. Measurement conditions for inductively coupled plasma-optical emission spectrometry (ICP–OES) have been optimized to reach robust plasma conditions and the reliability of the analysis has been investigated by using …
Les déterminants personnels du bien-être de l’écolier, de ses satisfactions en classe et de sa performance scolaire
2017
This work focuses on the study of personal determinants of pupils' achievement and reactions toward class (well-being; satisfaction with teacher, learning and class). A theoretical model is tested by commonality analysis and refined by causal paths analysis. The results show that external and cognitive prior characteristics (age, gender, socio-occupational background, academic record) have direct effects on criteria variables, and indirectly via the attitudes toward school (negative feelings; scholastic interest; aspirations for future studies; "scholastic anxiety, worry and stress"; fun school). Using two structural models, we explained 39 % of the variance in academic achievement, and fro…
Experimental Observation of a Large Low-Frequency Band Gap in a Polymer Waveguide
2018
The quest for large and low-frequency band gaps is one of the principal objectives pursued in a number of engineering applications, ranging from noise absorption to vibration control, and to seismic wave abatement. For this purpose, a plethora of complex architectures (including multiphase materials) and multiphysics approaches have been proposed in the past, often involving difficulties in their practical realization. To address the issue of proposing a material design that enables large band gaps using a simple configuration, in this study we propose an easy-to-manufacture design able to open large, low-frequency complete Lamb band gaps exploiting a suitable arrangement of masses and stif…
The Role of Excited Oxygen Molecules in the Formation of the Secondary Ozone Layer at 87 to 97 km
2018
The secondary ozone layer is located at elevations of 87 to 97 km in the upper mesosphere – lower thermosphere. It overlaps with the ionospheric D-layer. Daytime intensive UV radiation is dissociating O2 molecules to O atoms and photoexcitating O2 molecules up to 11.07eV level. Ozone photolysis between the wavelengths of 118.7–121.6 nm produces three oxygen atoms from one ozone molecule. Collision reactions of O2(B3 Σu —) and O2(X3 Σg —, υ≥26) with O2(X3 Σg —, υ=0) produce additional oxygen atoms. The number of oxygen atoms is maintained at such a high level that a small but significant ozone concentration survives. UV radiation weakens radically during the night. The number of O atoms show…
Incorporación de elementos traza en conchas de melanopsis durante el crecimiento : posibilidades de aplicación en paleoecología
1988
El objetivo del presente trabajo está encaminado al estudio de las variaciones de oligoelementos en la concha de un gasterópodo de agua dulce del género Melanopsis (U dufouri (FERUSSAC), con dos morfotipos) y si éstas tienen que ver, o no, con la fluctuación de una serie de parámetros ambientales. La importancia del trabajo radica en la posibilidad de la aplicación paleoecológica de sus resultados, ya que el género MelanopsÍs tiene un abundante registro fósil durante todo el Cenozoico. La incorporación de oligoelementos se efectúa a medida que la concha va creciendo por acreción; lo ideal sería que tal crecimiento fuera circadiano, ya que se podría seguir día a día, sobre la concha, la fluc…