Search results for "Fig"
showing 10 items of 1359 documents
The HisClima database: historical weather logs for automatic transcription and information extraction
2021
Knowing the weather and atmospheric conditions from the past can help weather researchers to generate models like the ones used to predict how weather conditions are likely to change as global temperatures continue to rise. Many historical weather records are available from the past registered on a systemic basis. Historical weather logs were registered in ships, when they were on the high seas, recording daily weather conditions such as: wind speed, temperature, coordinates, etc. These historical documents represent an important source of knowledge with valuable information to extract climatic information of several centuries ago. This paper presents a database for researching about the ca…
Lietvedības sistēmas papildināšana ar klienta pārvaldīšanas moduli
2019
Kvalifikācijas darba mērķis ir izstrādāt klienta pārvaldīšanas moduli lietvedības sistēmai un integrēt to pašā sistēmā. Moduļi ir lietvedības SharePoint serverī izsaucama aplikācija, kas spēj pārvaldīt lietvedības sistēmas konfigurācijas dotām klientam un pielietot tos sistēmai. Modulī tiek integrēts žurnāls, kas ļauj apskatīt klienta darbību vēsturi gan lietvedības sistēmā, gan pašā modulī. Modulim pastāv administratora lietotājs, kuram ir papildināta funkcionalitāte, salīdzinot ar parasto klientu. Administratora nolūks ir tehniska atbalsta sniegšana klientam. Viņam ir iespējas pārvaldīt citu lietotāju konfigurācijas, pielietot tos, pārskatīt viņu žurnālus, veidot un dzēst jaunus lietotāju…
Ar superformulu ģenerētu objektu īpašības un pielietojumi
2019
Bakalaura darba mērķis ir izpētīt ierobežojumus, kādi attiecas uz figūrām, kuras ģenerētas, izmantojot superformulu, kā arī pētīt praktiskus pielietojumus šādam figūru ģenerēšanas paņēmienam. Dabā sastopamu formu ģenerēšanai bieži vien nepieciešami netriviāli vienādojumi vai pārveidojumi, kas patērē gan laika, gan atmiņas resursus. Izmantojot superformulu, šādu formu ģenerēšanai nepieciešami tikai daži parametri. Tā kā visas šādi ģenerētas figūras apraksta viena formula, tad ir iespējams izmantot analītiskas metodes, lai noteiktu figūru un taišņu krustpunktus, kā arī attālumus starp šādi veidotām figūrām. Darbā vispirms tiek apskatītas superelipšu un superformulas īpašības, pēc tam tiek aps…
Enhanced β-turn conformational stability of tripeptides containing Δphe in cis over trans configuration
2013
Conformations of three pairs of dehydropeptides with the opposite configuration of the Delta Phe residue, Boc-Gly-Delta(Z/E)Phe-Phe-p-NA (Z- p -NA and E- p -NA), Boc-Gly-Delta(Z/E)Phe-Phe-OMe (Z-OMe and E-OMe), and Boc-Gly-Delta(Z/E)Phe-Phe-OH (Z-OH and E-OH) were compared on the basis of CD and NMR studies in MeOH, TFE, and DMSO. The CD results were used as the additional input data for the NMR-based calculations of the detailed solution conformations of the peptides. It was found that Z- p -NA, E- p -NA, Z-OMe, and Z-OH adopt the beta-turn conformations and E-OMe and E-OH are unordered. There are two overlapping type III beta-turns in Z- p -NA, type II' beta-turn in E- p -NA, and type II …
Ultra-fast intensified frame images from an electron cyclotron resonance hydrogen plasma at 2.45 GHz: some space distributions of visible and monochr…
2014
First results from an ultra-fast frame image acquisition diagnostic coupled to a 2.45 GHz microwave hydrogen discharge are presented. The plasma reactor has been modified to include a transparent doubled shielded quartz window allowing to viewing the full plasma volume. Pictures describing the breakdown process at 1μs exposure time have been obtained for integrated visible light signal, Balmer-alpha, Balmer-beta lines, and Fulcher-band. Several different plasma emission distributions are reported. The distribution depends on the magnetic field configuration, incident microwave power, and neutral gas pressure. peerReviewed
Perturbative treatment of triple excitations in coupled‐cluster calculations of nuclear magnetic shielding constants
1996
A theory for the calculation of nuclear magnetic shielding constants at the coupled‐cluster singles and doubles level augmented by a perturbative correction for connected triple excitations (CCSD(T)) has been developed and implemented. The approach, which is based on the gauge‐including atomic orbital (GIAO) ansatz, is illustrated by several numerical examples. These include a comparison of CCSD(T) and other highly correlated methods with full configuration interaction for the BH molecule, and a systematic comparison with experiment for HF, H2O,NH3, CH4, N2, CO, HCN, and F2. The results demonstrate the importance of triple excitations in establishing quantitative accuracy. Finally, the abil…
Acid-induced rearrangement of epoxygermacra-8,12-olides: synthesis and absolute configuration of guaiane and eudesmane derivatives from artemisiifolin
2010
A study on the acid-induced rearrangement of 4,5-epoxy- and 1,10-epoxygermacra-8,12-olides was carried out. From a 4,5-epoxy derivative, guaianes were obtained, whereas 1,10-epoxy derivatives furnished, depending on the stereochemistry of the C-1/C-10 epoxy ring, trans-5β,10α- or trans-5α,10β-eudesmanolides.
Exploring hand-portable nano-liquid chromatography for in place water analysis: Determination of trimethylxanthines as a use case.
2020
Abstract Analytical performance and optimization of figures of merit of a portable nano liquid chromatograph (NanoLC) with UV detection at 255 nm have been established for in place analysis. Methylxanthines: caffeine, theophylline and theobromine were selected as target analytes. A fast lab method based on IT-SPME coupled on line with capillary liquid chromatograph (CapLC) with diode array detection (DAD) was employed for comparative studies. IT-SPME and solid phase extraction were coupled off-line to NanoLC for improving instrumental parameters, mainly detection capacity and selectivity. IT-SPME or SPE/portable NanoLC based methods were superior in terms of chromatographic resolution and o…
Development and characterization of a thermal inkjet-based aerosol generator for micro-volume sample introduction in analytical atomic spectrometry
2011
A novel system for the introduction of liquid samples into analytical plasmas for atomic spectrometric analysis is presented in this manuscript for the first time. The proposed “drop-on-demand” (DOD) aerosol generator is based on the use of a modified thermal inkjet cartridge. This system employs a lab-built microcontroller, which allows accessing all parameters important for driving the dosing cartridge for the generation of pL-droplets from sample volumes in the μL range. The droplet generation frequency, thus the resulting liquid flow rate, is variable over a wide range from the generation of isolated droplets up to a theoretical flow rate of approximately 2 mL min−1, with parallel opera…
Synthesis of 8-aminomorphans with high KOR affinity
2021
2-Azabicyclo[3.3.1]nonanes (morphans) with a (3,4-dichlorophenyl)acetyl group at 2-position and a pyrrolidino moiety at 8-position were designed as conformationally restricted analogs of piperidine-based KOR agonists. The synthesis started with 4-oxopiperidine-2-carboxylic acid comprising 13 reaction steps. At first the ketone 10 was transformed into diester 7 bearing a propionate side chain. Dieckmann condensation of diester 7 to afford bicyclic enolester 14 and subsequent Krapcho deethoxycarbonylation represent the key steps of the synthesis. The enantiomeric pyrrolidines (1S,5R,8R)-5a and (1R,5S,8S)-5a were separated by chiral HPLC. The eutomer (1S,5R,8R)-5a showed high KOR affinity (K-i…