Integral scales in the surface atmospheric boundary layer for Bora flows

Mnogi numerički i klimatski modeli za prognozu vremena koriste prognostički oblik jednadžbe turbulentne kinetičke energije (TKE). Mjera disipacije TKE se parametrizira odgovarajućim omjerom TKE i takozvanom integralnom skalom duljine, što je otežano određenim numeričkim koeficijentom. U znanstvenoj zajednici ne postoji dogovor o jedinstvenoj formulaciji takve integralne skale. Stoga, u literaturi nalazimo različite oblike integralne skale. Međutim, one se najčešće izvode iz autokorelacijske funkcije i Fourierovog spektra komponenti brzine vjetra. To su, takozvane skale 1/e i skala prelaska nule te skala za koju normalizirani Fourierov spektar postiže maksimum. Cilj ovog rada je procjena integralne skale turbulencije i pripadnog numeričkog koeficijenta, po prvi put, za buru. Za analizu koristimo podatke prikupljene „WindMaster“ ultrasoničnim anemometrima na visinama 2, 5 i 10 m, u neposrednoj blizini novog Masleničkog mosta, s čestinom uzrokovanja od 20 Hz. U razdoblju od 09. listopada 2015. do 09. listopada 2016. godine izdvojeno je 48 epizoda bura u trajanju od otprilike 1206 sati. Tako veliki set podataka nam omogućava procjenu navedene integralne skale i numeričkog koeficijenta u svrhu testiranja parametrizacije TKE i disipacije TKE u prizemnom sloju za buru. Takozvana skala 1/e se pokazala najboljom za procjenu integralne skale turbulencije za buru. U konačnici, na temelju analiziranih podataka uočeno je znatno odstupanje numeričkog koeficijenta za buru u odnosu na vrijednosti korištenih u znanstvenoj zajednici, koje predlažu npr. Cuxart i sur. (2006), to nam ostavlja prostora za daljnja detaljnija istraživanja u budućnosti.Many NWP and climate models use prognostic turbulence kinetic energy (TKE) equation. TKE dissipation ratio is parameterized via suitable ratio of TKE and so-called integral length scale for turbulence, which is weighted by a certain numerical coefficient. The scientific community does not have unique agreement on formulation of integral turbulence scales. Therefore, in literature we find various forms of those integral scales. However, usually they are derived from autocorrelation functions and Fourier spectra of wind speed components. These are the so-called 1/e and zero crossing scales and the scale at which a normalized Fourier spectra achieve their maximum value. The aim of this study is to evaluate integral turbulence scales and the related coefficient, for the first time for bora flows. For the analysis we used dana collected with „WindMaster“ ultrasonic anemometers at heights 2, 5 and 10 m, close to new Maslenica bridge, with a frequency sampling of 20 Hz. In the period from 09 October 2015 to 09 October 2016 recorded were 48 bora events with cumulative duration of 1206 hours. Such a large dataset gives us an opportunity to evaluate integral turbulence scales and the related numerical coefficient to test the parametrization of the TKE dissipation rate for the atmospheric surface boundary layer in bora flows. So-called 1/e scale proved to be the best estimate for the integral turbulence scale. At the end, based on the analyzed dataset, it has been observed a significant disagreement of the numerical coefficient for bora flows compared with values used in the literature, proposed by e.g. Cuxart et al. (2006). This leaves us space for further studies in future

Automatic procedural 3D modelling of buildings

The problem of modelling, especially of large-scale virtual urban environments such as city areas is today very challenging for cartographers. Cities are difficult to model in detail because of their often complex geometries. This paper describes the applied and tested new procedures for the development of a test three-dimensional urban area model using the Esri CityEngine software, which is based on procedural modelling. This process involves three steps. The first step is to collect the available data, as well as the Digital Model Relief data. The second step is to create a Computer Generated Architecture (CGA) file that contains a set of rules used by the software for an automatic generation of the model. The third step is to create and visualize 3D models in the CityEngine software because it can be programmed, for example, according to the rules of cartographic visualization. The Level of Detail (LOD) 2 was reconstructed. Several potential uses of such 3D visualization are also described

Evaluating the use of an Unmanned Aerial Vehicle (UAV)-based active AirCore system to quantify methane emissions from dairy cows

Enteric fermentation and manure methane emissions from livestock are major anthropogenic greenhouse gas emissions. In general, direct measurements of farm-scale methane emissions are scarce due to the source complexity and the limitations of existing atmospheric sampling methods. Using an innovative UAV-based active AirCore system, we have performed accurate atmospheric measurements of CH4 mole fractions downwind of a dairy cow farm in the Netherlands on four individual days during the period from March 2017 to March 2019. The total CH4 emission rates from the farm were determined using the UAV-based mass balance approach to be 1.1-2.4 g/s. After subtracting estimated emission factors of manure onsite, we derived the enteric emission factors to be 0.20-0.51 kgCH4/AU/d (1 AU = 500 kg animal weight) of dairy cows. We show that the uncertainties of the estimates were dominated by the variabilities in the wind speed and the angle between the wind and the flight transect. Furthermore, nonsimultaneous sampling in the vertical direction of the plume is one of the main limiting factors to achieving accurate estimate of the CH4 emissions from the farm. In addition, a N2O tracer release experiment at the farm was performed when both a UAV and a mobile van were present to simultaneously sample the N2O tracer and the CH4 plumes from the farm, improving the source quantification with a correction factor of 1.04 and 1.22 for the inverse Gaussian approach and for the mass balance approach, respectively. The UAV-based active AirCore system is capable of providing useful estimates of CH4 emissions from dairy cow farms. The uncertainties of the estimates can be improved when combined with accurate measurements of local wind speed and direction or when combined with a tracer approach

Rak dojke - dijagnostika i liječenje

Rak dojke je najčešća maligna bolest u žena, čini 25% svih tumora i uzrokuje 15% smrti od raka. U Hrvatskoj se godišnje dijagnosticira oko 2 000 slučajeva, a oko 800 žena umre od raka dojke. Kao takav, predstavlja ozbiljan javnozdravstveni problem. U ovome radu biti će opisana anatomija i fiziologija dojke. Objašnjene su etiologija, epidemiologija i simptomatologija tumora dojke. Opisane su i navedene osnovne vrste benignih i malignih tumora dojke te rijetki slučajevi kao što je tumor dojke kod muškaraca. Zahvaljujući ranoj detekciji, stopa izlječivosti kod raka dojke raste. U dijagnostici raka dojke koriste se mamografija i ultrazvučna dijagnostika kao osnovne metode detekcije. Ove metode su detaljno opisane u radu, kao i ostale koje se koriste pri dijagnostici i praćenju stadija bolesti. Izlječenje i prognoza bolesnice s rakom dojke ponajviše ovise o stadiju bolesti pri otkrivanju. Ovisno o prognostičkim čimbenicima ordinira se određena terapija. Ona može biti lokalna i sistematska. Metode lokalne terapije su kirurški zahvati i terapija zračenjem. Kemoterapija i hormonska terapija djeluju na stanice svuda u tijelu i stoga pripadaju sistematskoj terapiji. Kako radiološki tehnolog pripada multidisciplinarnom timu pri dijagnostici i liječenju raka dojke, njegova je uloga važna jer je on poveznica između bolesnika i ostalih članova tima. Za kompletno provođenje postupaka u dijagnostici i terapiji, radiološki tehnolog mora posjedovati znanja iz anatomije, radiobiologije, fizike i onkologije. Osim primjene tih znanja, potrebno je imati razvijene komunikacijske vještine i primijeniti ih ovisno o situaciji

Rak dojke - dijagnostika i liječenje

Rak dojke je najčešća maligna bolest u žena, čini 25% svih tumora i uzrokuje 15% smrti od raka. U Hrvatskoj se godišnje dijagnosticira oko 2 000 slučajeva, a oko 800 žena umre od raka dojke. Kao takav, predstavlja ozbiljan javnozdravstveni problem. U ovome radu biti će opisana anatomija i fiziologija dojke. Objašnjene su etiologija, epidemiologija i simptomatologija tumora dojke. Opisane su i navedene osnovne vrste benignih i malignih tumora dojke te rijetki slučajevi kao što je tumor dojke kod muškaraca. Zahvaljujući ranoj detekciji, stopa izlječivosti kod raka dojke raste. U dijagnostici raka dojke koriste se mamografija i ultrazvučna dijagnostika kao osnovne metode detekcije. Ove metode su detaljno opisane u radu, kao i ostale koje se koriste pri dijagnostici i praćenju stadija bolesti. Izlječenje i prognoza bolesnice s rakom dojke ponajviše ovise o stadiju bolesti pri otkrivanju. Ovisno o prognostičkim čimbenicima ordinira se određena terapija. Ona može biti lokalna i sistematska. Metode lokalne terapije su kirurški zahvati i terapija zračenjem. Kemoterapija i hormonska terapija djeluju na stanice svuda u tijelu i stoga pripadaju sistematskoj terapiji. Kako radiološki tehnolog pripada multidisciplinarnom timu pri dijagnostici i liječenju raka dojke, njegova je uloga važna jer je on poveznica između bolesnika i ostalih članova tima. Za kompletno provođenje postupaka u dijagnostici i terapiji, radiološki tehnolog mora posjedovati znanja iz anatomije, radiobiologije, fizike i onkologije. Osim primjene tih znanja, potrebno je imati razvijene komunikacijske vještine i primijeniti ih ovisno o situaciji

High potential for CH4 emission mitigation from oil infrastructure in one of EU's major production regions

Ambitious methane (CH4) emission mitigation represents one of the most effective opportunities to slow the rate of global warming over the next decades. The oil and gas (O&amp;G) sector is a significant source of methane emissions, with technically feasible and cost-effective emission mitigation options. Romania, a key O&amp;G producer within the EU, with the second highest reported annual CH4 emissions from the energy sector in the year 2020 (Greenhouse Gas Inventory Data - Comparison by Category, 2022), can play an important role towards the EU's emission reduction targets. In this study, we quantify CH4 emissions from onshore oil production sites in Romania at source and facility level using a combination of ground- and drone-based measurement techniques. Measured emissions were characterized by heavily skewed distributions, with 10% of the sites accounting for more than 70% of total emissions. Integrating the results from all site-level quantifications with different approaches, we derive a central estimate of 5.4 kg h-1 per site of CH4 (3.6 %-8.4 %, 95% confidence interval) for oil production sites. This estimate represents the third highest when compared to measurementbased estimates of similar facilities from other production regions. Based on our results, we estimate a total of 120 kt CH4 yr-1 (range: 79-180 kt yr-1) from oil production sites in our studied areas in Romania. This is approximately 2.5 times higher than the reported emissions from the entire Romanian oil production sector for 2020. Based on the source-level characterization, up to three-quarters of the detected emissions from oil production sites are related to operational venting. Our results suggest that O&amp;G production infrastructure in Romania holds a massive mitigation potential, specifically by implementing measures to capture the gas and minimize operational venting and leaks.</p

High potential for CH₄ emission mitigation from oil infrastructure in one of EU's major production regions

Ambitious methane (CH4) emission mitigation represents one of the most effective opportunities to slow the rate of global warming over the next decades. The oil and gas (O&amp;G) sector is a significant source of methane emissions, with technically feasible and cost-effective emission mitigation options. Romania, a key O&amp;G producer within the EU, with the second highest reported annual CH4 emissions from the energy sector in the year 2020 (Greenhouse Gas Inventory Data - Comparison by Category, 2022), can play an important role towards the EU's emission reduction targets. In this study, we quantify CH4 emissions from onshore oil production sites in Romania at source and facility level using a combination of ground- and drone-based measurement techniques. Measured emissions were characterized by heavily skewed distributions, with 10% of the sites accounting for more than 70% of total emissions. Integrating the results from all site-level quantifications with different approaches, we derive a central estimate of 5.4 kg h-1 per site of CH4 (3.6 %-8.4 %, 95% confidence interval) for oil production sites. This estimate represents the third highest when compared to measurement-based estimates of similar facilities from other production regions. Based on our results, we estimate a total of 120 kt CH4 yr-1 (range: 79-180 kt yr-1) from oil production sites in our studied areas in Romania. This is approximately 2.5 times higher than the reported emissions from the entire Romanian oil production sector for 2020. Based on the source-level characterization, up to three-quarters of the detected emissions from oil production sites are related to operational venting. Our results suggest that O&amp;G production infrastructure in Romania holds a massive mitigation potential, specifically by implementing measures to capture the gas and minimize operational venting and leaks.</p