Search results for "BED"
showing 10 items of 1605 documents
A study of Type B uncertainties associated with the photoelectric effect in low-energy Monte Carlo simulations
2021
The goal of this manuscript is to estimate Type B uncertainties in absorbed-dose calculations arising from the different implementations in current state-of-the-art Monte Carlo codes of low-energy photon cross-sections (<200 keV). Monte Carlo simulations are carried out using three codes widely used in the low-energy domain: PENELOPE-2018, EGSnrc, and MCNP. Mass energy-absorption coefficients for water, air, graphite, and their respective ratios; absorbed dose; and photon-fluence spectra are considered. Benchmark simulations using similar cross-sections have been performed. The differences observed between these quantities when different cross-sections are considered are taken to be a go…
Termālā stāvokļa modelēšana un zaļās infrastruktūras nozīme Rīgas centrā
2021
Globālo klimatu pārmaiņu rezultātā tiek prognozēti biežāki un ekstremālāki laika apstākļi īpaši pilsētu teritorijās. Ekstrēmāla karstuma parādība un pilsētu karstuma salas ir svarīgi faktori, kas ietekmē sabiedrības veselību un dzīves kvalitāti. Viens no risinājumiem karstuma salas ietekmes mazināšanā ir veģetācija, kas veicina iztvaikošanas un dzesēšanas efektu, taču pilsētās bieži vien to daudzums nav pietiekošs. Maģistra darbā novērtēta zaļās infrastruktūras nozīme karstuma viļņu laikā Rīgas centrā (Brīvības ielā 73, Dzirnavu ielā 91, Lāčplēša ielā 3, Kr. Valdemāra ielā 18 un Aspazijas bulvārī 5), izmantojot modelēšanas metodi. Termālā stāvokļa modelēšanai izmantota programmatūra Envi-me…
Predictive First-principles Modeling of a Photosynthetic Antenna Protein : The Fenna-Matthews-Olson Complex
2020
High efficiency of light harvesting in photosynthetic pigment-protein complexes is governed by evolutionary-perfected protein-assisted tuning of individual pigment properties and inter-pigment interactions. Due to the large number of spectrally overlapping pigments in a typical photosynthetic complex, experimental methods often fail to unambiguously identify individual chromophore properties. Here we report a first principles-based modeling protocol capable of predicting properties of pigments in protein environment to a high precision. The technique was applied to successfully uncover electronic properties of the Fenna-Matthews-Olson (FMO) pigment-protein complex. Each of the three subunit…
In Vitro Evaluation of Poly(lactide-co-glycolide) In Situ Forming Gels for Bedaquiline Fumarate Salt and Pharmacokinetics Following Subcutaneous Inje…
2021
This study evaluated in vitro and in vivo drug release of bedaquiline from in situ forming gels (ISGs) containing 200 mg eq./g bedaquiline fumarate salt prepared with four different grades of poly(d,l-lactide) (PDLLA) or poly(d,l-lactide-co-glycolide) (PLGA) with a lactide/glycolide ratio of 50/50 or 75/25 and acid (A) or ester (E) end-capping in N-methyl-2-pyrrolidone at a polymer/solvent ratio of 20/80% (w/w). Mean in vitro drug release in 0.05 M phosphate buffer pH 7.4 with 1% (w/v) sodium lauryl sulphate was 37.3, 47.1, 53.3, and 62.3% within 28 days for ISGs containing PLGA5050A, PDLLA, PLGA7525A, and PLGA7525E, respectively. The data suggested that drug release was primarily controlle…
Lääkintälaitteiden kyberturvallisuuden standardit ja testaaminen
2017
Tietotekniikkaa sisältävät lääkintälaitteet pitävät meidät hengissä, jos kehomme pettää. Esimerkiksi ostoskeskuksissa olevat älykkäät defibrillaattorit antavat maallikoillekin mahdollisuuden antaa tehokasta ensiapua sydänkohtaukseen. Tietotekniikan käyttäminen lääkintälaitteissa tuo mahdollisuuksien lisäksi uhkia. Tässä tutkielmassa perehdytään siihen, miten standardit ja testaaminen edistävät kyberturvallisuutta, uhkien torjumista. Ensin tehdään katsaus kirjallisuuteen ja standardeihin ja sitten kytketään tieto käytäntöön testaamalla potilasmonitoria kirjallisuuden pohjalta. Tulos oli, että tutkittava potilasmonitori oli hyvin avoin fyysisen käyttöliittymän kautta. Esimerkiksi potilastiedo…
Measurement and communication interfaces for distributed generation in smart grids
2013
The aim of this work is to perform a feasibility study on the measurement and communication strategies for the development of a new generation of interface devices for distributed generators and their integration on smart grids. The communication system can use one or more technologies, at the various levels, creating a low cost network infrastructure, in the framework of a SCADA (Supervisory Control and Data Acquisition) architecture. As regards the measurements, the attention is focused on the anti-islanding protection, based on a hybrid solution, which makes use of local measurements and communications with the grid, at both MV and LV level by employing the PLC technology. Some simulatio…
Institutional perspectives in transition : research groups’ profiles and embeddedness in organisational and national context
2019
Research into differentiation and profiling of knowledge producing institutions through the lenses of institutional logics and field embeddedness have proliferated in recent years. By discussing this process in the context of research groups, as those basic units in which knowledge production epistemically and practically takes place, this article offers a contribution to the theoretical discussion on organisational differentiation. Based on a small-N comparative case study of research groups operating in different national and organisational contexts on a single, highly competitive and interdisciplinary applied sciences field, nanosciences, the article proposes research group profiles as h…
Column Adsorption Studies for the Removal of Ammonium Using Na-Zeolite-Based Geopolymers
2022
The aim of this study was to examine the removal of ammonium ions from a synthetic model solution by using Na-zeolite-based geopolymers. Na-zeolite (=analcime) is a residue from mining industry. Three adsorbents were prepared from Na-zeolite using different production steps and metakaolin as a blending agent. These novel adsorbents were investigated in a fixed-bed column system where the effects of different flow rates with the initial ammonium concentration of 40 mg/L were studied. The Thomas, Bohart–Adams and Yoon–Nelson breakthrough curve models fitted well with the experimental data with a high R2 value. After adsorption experiments, adsorbents were regenerated using a mixture of 0.2 M …
Jet fragmentation transverse momentum distributions in pp and p-Pb collisions at √s, √sNN = 5.02 TeV
2021
Jet fragmentation transverse momentum (jT) distributions are measured in proton-proton (pp) and proton-lead (p-Pb) collisions at √sNN = 5.02 TeV with the ALICE experiment at the LHC. Jets are reconstructed with the ALICE tracking detectors and electromagnetic calorimeter using the anti-kT algorithm with resolution parameter R = 0.4 in the pseudorapidity range |η| < 0.25. The jT values are calculated for charged particles inside a fixed cone with a radius R = 0.4 around the reconstructed jet axis. The measured jT distributions are compared with a variety of parton-shower models. Herwig and Pythia 8 based models describe the data well for the higher jT region, while they underestimate the low…
THE MOSAIC OF THE FRIGIDARIUM OF “VILLA BONANNO” IN PALERMO: MINERALOGICAL AND PETROGRAPHIC ANALYSES FOR IN SITU CONSERVATION AND RESTORATION INTERVE…
2018
The topic of this study was the mineralogical and petrographic characterization of bedding mortars (made of different layers) and tesserae of Roman age (3rd century A.D.), taken from the mosaic of the Frigidarium of “Villa Bonanno”, brought to light by archaeological excavations conducted in the historical centre of Palermo. The collected samples have been analysed by thin-section optical microscopy (PLM), and scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS). The study was aimed to define the “recipe” (composition of aggregate and binder, aggregate size distribution, aggregate/binder ratio), in order to assess the provenance of raw m…