A new perspective in bio-refining : Levoglucosenone and cleaner lignin from waste biorefinery hydrolysis lignin by selective conversion of residual saccharides

An unexpected opportunity is reported to improve the sustainability of biorefineries whereby 8 wt% levoglucosenone (LGE) can be derived from unconverted saccharides in a lignin-rich biorefinery waste stream in a highly selective fashion (>90%). Additionally, in the process a purer lignin is obtained which can be used for further processing or materials applications. LGE is a valuable and versatile product with a plethora of applications

Evaluation of regional climate models ALARO-0 and REMO2015 at 0.22 degrees resolution over the CORDEX Central Asia domain

To allow for climate impact studies on human and natural systems, high-resolution climate information is needed. Over some parts of the world plenty of regional climate simulations have been carried out, while in other regions hardly any high-resolution climate information is available. The CORDEX Central Asia domain is one of these regions, and this article describes the evaluation for two regional climate models (RCMs), REMO and ALARO-0, that were run for the first time at a horizontal resolution of 0.22 degrees (25 km) over this region. The output of the ERA-Interim-driven RCMs is compared with different observational datasets over the 1980-2017 period. REMO scores better for temperature, whereas the ALARO-0 model prevails for precipitation. Studying specific subregions provides deeper insight into the strengths and weaknesses of both RCMs over the CAS-CORDEX domain. For example, ALARO-0 has difficulties in simulating the temperature over the northern part of the domain, particularly when snow cover is present, while REMO poorly simulates the annual cycle of precipitation over the Tibetan Plateau. The evaluation of minimum and maximum temperature demonstrates that both models underestimate the daily temper-ature range. This study aims to evaluate whether REMO and ALARO-0 provide reliable climate information over the CAS-CORDEX domain for impact modeling and environmental assessment applications. Depending on the evaluated season and variable, it is demonstrated that the produced climate data can be used in several subregions, e.g., temperature and precipitation over western Central Asia in autumn. At the same time, a bias adjustment is required for regions where significant biases have been identified

Social network for photographers

Šī kvalifikācijas darba ietvaros tiek izstrādāta tīmekļa vietne – sociālais tīkls fotogrāfiem, kurš dos iespēju cilvēkiem, kuriem patīk fotografēt un kuri izturas pret fotografēšanu kā pret mākslu, sazināties savā starpā, dalīties savās prasmēs, pieredzē, parādīt citiem savus darbus un paskatīties citu darbus, iepazīt citu cilvēku pieredzi un gūt jaunas zināšanas īpaši pielāgotā un attīstītā speciāli tam vidē. Darba dokumentācijā aprakstītas sistēmas funkcionālās prasības, datu glabāšanas projektējums, vietnes izstrādes gaita, izstrādes laikietilpība un ir sniegti izstrādātās sistēmas koda fragmenti. Darba izstrādes rezultātā tika iegūta reāli strādājoša, patstāvīga, neliela sistēma – sociālais tīkls fotogrāfiem, kas spēj nodrošināt lietotājam nepieciešamo pamatfunkcionalitāti šajā jomā un administrēšanas rīkus kārtības uzturēšanai.The aim of this qualification work is to create a website – social newtork for photographers, which will give people, who love making photos a place in web to communicate and share their works and experiences. In the documentation of the work there are described functional requirements, date storage structure, the way, how the website was created, labor-intensity and are included some code fragments as an example of work. In the end of work, there are fully working basic social newfork specialized on photographers. It can provide main functionality for the photographing users and give tools for sistem administration

Forecasting and Simulation of Currency Exchange Rate Volatility

Valūtas apmaiņas kursa volatilitātes jeb svārstīguma modelēšana un prognozēšana, izmantojot ekonometriskus modeļus, pēdējos gados, īpaši saistībā ar globālo finanšu krīzi, kad pieaug nenoteiktība un mazinās uzticība tirgiem, gūst arvien lielāku ievērību. Valūtas kursa volatilitāte ietekmē starptautiskās tirdzniecības apjomu, investīcijas, konkurētspēju un citus ekonomiskos rādītājus. Maģistra darbā pētīti valūtu pāri EUR/CHF, EUR/AUD un USD/JPY. Aplūkojot laika periodu no 2009. gada līdz 2013. gadam, katram no valūtu pāriem izveidoti GARCH tipa modeļi, kas spēj modelēt ar valūtas kursu volatilitāti saistītos efektus, proti, asimetrijas efektus uz pozitīviem un negatīviem šokiem, volatilitātes klasteru veidošanās efektus, kā arī sviras efektus. Darba uzdevums ir atrast, kāda tipa GARCH modeļi ir piemērotākie katram no šiem valūtu pāriem, un izpētīt, kā tas, cik lielā mērā globālā finanšu krīze skārusi kādu valsti, ietekmē ekonometrisko modeļu spēju modelēt valūtas kursa volatilitāti.In recent years modeling and forecasting of exchange rate volatility using econometric models has become an important subject, as uncertainty is high and market confidence levels are low due to Global financial crisis. Exchange rate volatility influences international trade, investment level, competitiveness and other economic indicators. Three currency pairs have been investigated in the master’s thesis, namely EUR/CHF, EUR/AUD and USD/JPY. For time period from 2009 to 2013 different GARCH type models were created. These models are able to capture exchange rate volatility effects - asymmetric response to positive and negative return shocks, volatility clustering, as well as leverage effects. Task of the thesis is to find, which type of GARCH models is suitable for each of the three currency pairs, and to do a research on impact of Global financial crisis in different countries and how it affects ability of models to predict exchange rate volatility

Research and analysis of mesh topology network capabilities

Bakalaura darbs ir veltīts sietveida topoloģijas tīkliem. Bakalaura darbā tiks pētītas šādu tīklu pielietošanas iespējas, darbības īpatnības un īpašības. Darba beigās tiks iegūts un apkopots liels daudzums kvalitatīvas informācijas par sietveida topoloģijas pielietojumu praktiskā līmenī mūdsienās, kā arī par perspektīviem pētījumiem globāla sietveita tīkla izveidē. Darbā ir praktiski apskatīts un izmēģināts Hyperboria tīkls, kurš strādā uz, arī izpētīta darba ietvaros, cjdns protokola pamata. Darbā iekļautas zināšanas par sietveida tīkliem, to īpašībām, izmantojumu un perspektīvām, par cjdns un citiem protokoliem ļoti lielu sietveida tīklu efektīvai maršrutēšanai, kā arī par Hyperboria tīklu. Darbs ir interesants gan tīmekļa lietotājiem, gan tīklu administratoriem, kuri varētu izmantot darbā esošas zināšanas par sietveida tīkliem.Bachelor thesis is devoted to mesh topology networks. In this Bachelor thesis will be explored mesh topology network possibilities and nature of activites and properties. At the end of thesis there will be obtained and collated large amount of quality information about theme and practical level of mesh usage as well as for perspectives in future creating global mesh network. At the thesis there is description of practical experiment and testing the Hyperboria network, which is working using cjdns protocol. The thesis includes knowldge about mesh topology networks and perspective global mesh network boulding. Thesis is specially interesting for network users and also administrators, which could use it in their professional activities