Search results for "PD"

WENO schemes applied to the quasi-relativistic Vlasov-Maxwell model for laser-plasma interaction

2014

Abstract In this paper we focus on WENO-based methods for the simulation of the 1D Quasi-Relativistic Vlasov–Maxwell (QRVM) model used to describe how a laser wave interacts with and heats a plasma by penetrating into it. We propose several non-oscillatory methods based on either Runge–Kutta (explicit) or Time-Splitting (implicit) time discretizations. We then show preliminary numerical experiments.

Korporācijas Selonijas Palīdzības biedrības Savstarpīgās Apdrošināšanas biedrības statuti

1926

Apdzīvojuma struktūras izmaiņas Stāmerienas pagastā no 20.gadsimta 20.gadiem

2016

Maģistra darbs „Apdzīvojuma struktūras izmaiņas Stāmerienas pagastā no 20.gadsimta 20.gadiem” izstrādāts Latvijas Universitātes Ģeogrāfijas un Zemes zinātņu fakultātes Ģeogrāfijas nodaļā laika posmā no 2015. – 2016.gadam. Maģistra darbs sastāv no ievada, anotācijas latviešu un angļu valodā, 4 nodaļām ar 6 apakšnodaļām, secinājumiem, izmantotās literatūras un avotu saraksta un 8 pielikumiem. Ievadā sniegtas ziņas par tēmas aktualitāti, darba mērķi un uzdevumiem. Maģistra darba mērķis ir analizēt apdzīvojuma struktūras izmaiņas Stāmerienas pagastā no 20.gadsimta 20.gadiem līdz mūsdienām. Pirmajā nodaļā sniegts zinātniskās literatūras apskats par apdzīvojumu, tā jēdzienu un raksturojošajiem rā…

Prolidase in the Marine Sponge Suberites domuncula: Enzyme Activity, Molecular Cloning, and Phylogenetic Relationship

1999

: The enzyme prolidase hydrolyzes the peptide bond that involves the imino nitrogen of proline or hydroxyproline; hence, it catalyzes the final step in collagen degradation. From mammals it is known that this enzyme plays a major role in the recycling of proline for collagen synthesis and can be considered to be essential for the control of cell growth. The dominant organic exoskeleton in sponges, especially in Demospongiae, is collagen and the collagen-related spongin. Here we demonstrate that crude extracts of the demosponge Suberites domuncula contain prolidase or prolidase-like activity. The complementary DNA encoding the putative prolidase was cloned from a library of the same animal. …

Subjective responses to different light sources. A study on light preferences and comparison of standard light measures with human individual estimat…

2013

The experimental research here described investigates how people perceive different light sources that have same CCTs and illuminance values on a visual task. The results show that photometric quantities like illuminances and CCTs fail to guarantee users comfort, because parameters like SPD of the light source and its technology heavily influence people's perception of an environment.

Four solutions for fractional p-Laplacian equations with asymmetric reactions

2020

We consider a Dirichlet type problem for a nonlinear, nonlocal equation driven by the degenerate fractional p-Laplacian, whose reaction combines a sublinear term depending on a positive parameter and an asymmetric perturbation (superlinear at positive infinity, at most linear at negative infinity). By means of critical point theory and Morse theory, we prove that, for small enough values of the parameter, such problem admits at least four nontrivial solutions: two positive, one negative, and one nodal. As a tool, we prove a Brezis-Oswald type comparison result.

Cryopreservation of Digitalis obscura selected genotypes by encapsulation-dehydration

2001

Shoot-tips from several genotypes of the cardenolide-producing perennial shrub Digitalis obscura L. were successfully cryopreserved using the encapsulation-dehydration technique. Precultivation on MS medium containing 0.5 M sucrose, followed by 2.5 h dehydration (final weight 30 %) induced shoot regrowth in 42 % of cryopreserved shoot-tips. Cold-hardening of the in vitro cultures before sucrose treatment dramatically increased shoot recovery up to 86 %. The optimized cryopreservation protocol was then employed using different shoot cultures from five D. obscura genotypes. Responses to cryopreservation depended mainly on the genotype, best results being obtained when shoot tips from HU3 and …

On harmonic and biharmonic Bézier surfaces

2004

We present a new method of surface generation from prescribed boundaries based on the elliptic partial differential operators. In particular, we focus on the study of the so-called harmonic and biharmonic Bezier surfaces. The main result we report here is that any biharmonic Bezier surface is fully determined by the boundary control points. We compare the new method, by way of practical examples, with some related methods such as surfaces generation using discretisation masks and functional minimisations.

On the range of the attenuated ray transform for unitary connections

2013

We describe the range of the attenuated ray transform of a unitary connection on a simple surface acting on functions and 1-forms. We use this to determine the range of the ray transform acting on symmetric tensor fields.

A general 4th-order PDE method to generate Bézier surfaces from the boundary

2006

In this paper we present a method for generating Bezier surfaces from the boundary information based on a general 4th-order PDE. This is a generalisation of our previous work on harmonic and biharmonic Bezier surfaces whereby we studied the Bezier solutions for Laplace and the standard biharmonic equation, respectively. Here we study the Bezier solutions of the Euler-Lagrange equation associated with the most general quadratic functional. We show that there is a large class of fourth-order operators for which Bezier solutions exist and hence we show that such operators can be utilised to generate Bezier surfaces from the boundary information. As part of this work we present a general method…