Добірка наукової літератури з теми "Optimisation RD"

Abstract Reactive distillation (RD) has already demonstrated its potential to significantly increase reactant conversion and the purity of the target product. Our work focuses on the application of RD to reaction systems that feature more than one main reaction. In such multiple-reaction systems, the application of RD would enhance not only the reactant conversion but also the selectivity of the target product. The potential of RD to improve the product selectivity of multiple-reaction systems has not yet been fully exploited because of a shortage of available comprehensive experimental and theoretical studies. In the present article, we want to theoretically identify the full potential of RD technology in multiple-reaction systems by performing a detailed optimisation study. An evolutionary algorithm was applied and the obtained results were compared with those of a conventional stirred tank reactor to quantify the potential of RD to improve the target product selectivity of multiple-reaction systems. The consecutive transesterification of dimethyl carbonate with ethanol to form ethyl methyl carbonate and diethyl carbonate was used as a case study.

Important investmentsare made lately in the area of district heating, as a technology capable ofhelping countries to reach sustainability goals. In Romania, European fundswere spent for transition from the 2nd to the 3rdgeneration of district heating systems. The lack of appropriate monitoringsystems in old district heating systems makes optimisation nowadays very difficult,especially because nominal values used in the first design stage areoverestimated. Realistic nominal heat loads are necessary to make goodestimations of hydraulic parameters to be used for redesign. This studyproposes a method that uses the heat load duration curve theory to identify theappropriate nominal heat loads to be used for redesign. Comparison betweenresults obtained by applying the nominal heat loads of each consumer, as theywere established in the first design stage, and the ones identified by theproposed method are analyzed in a case study. The results show that errors arein the +/- 3% band, between the metered heat consumption rates and the proposedrates. The new method can be used for the sizing of pumps and district heatingnetworks after retrofit, in order to get better adjustments of the circulationpumps and increase of the energy efficiency.

This study aimed to investigate a techno-economic evaluation of the photovoltaic system, along with a diesel generator as a backup supply, to ensure a continuous twenty-four hours power supply per day, no matter the status of the weather. Healthcare centers in Bangladesh play a vital role in the health issues of the residents of rural areas. In this regard, a healthcare center in Baliadangi—Lahiri Hat Rd, Baliadangi, Thakurgaon, Bangladesh, was selected to be electrically empowered. The simulation software Hybrid Optimisation Model for Electric Renewables (HOMER) and the HOMER Powering Health tool were used to analyze and optimize the renewable energy required by the healthcare center. It was found that the healthcare center required a 24.3 kW solar PV system with a net current cost of $28,705.2; the levelized cost of electricity (LCOE) was $0.02728 per kW-hours, where renewable energy would provide 98% of the system’s total power requirements. The generator would provide 1% and the grid would supply the remaining 1%. The load analysis revealed that the hybrid PV system might be superior to other power sources for providing electricity for both the normal function and the emergencies that arise in healthcare’s day-to-day life. The outcome of the study is expected to be beneficial for both government and other stakeholders in decision-making.

Abstract Since the introduction of hydrofoils to the Moth sailing class in the early 2000’s foiling has become increasingly popular in sailing from windsurfers to large 75’ foiling monohulls. The last 3 America’s Cups have been competed on hydro foiling vessels. Design programs such as Velocity Prediction Programs (VPP) have become a key asset to America’s Cup teams to allow for the optimisation and testing of designs before manufacture. Presented is the development of a Six Degree-of-Freedom (6DoF) Quasi-Static Velocity Prediction Program (SVPP) and Dynamic Velocity Prediction Program (DVPP) for the 35th and 36th America's Cup foiling AC50 Catamaran and AC75 Monohull. The models have been validated against race data from the 35th and 36th America’s Cup showing good correlation for a wide wind range of 8 to 22 knots. The paper presents how the AC50 SVPP was used for analysis on the impact of Rudder Rake Differential (RD) on overall performance, and predicting the optimal wind range for use of the light and heavy weather dagger boards on the AC50 Catamaran. The AC75 SVPP and DVPP were used to analyse the affect of hull shape and the main foils’ fixed angle-of-attack (AOA) on time-to-fight and peak velocity to determine optimal foil setup and pitch angle when foiling. The SVPP and DVPP use XFLR5 software suite to model the foils. Experimental data for a T-foil tested in the Australian Maritime College towing tank facility has been used to predict viscous and free surface effect adjustments to the predictions from XFLR5.

Abstract Abstract 494 Several randomised pediatric trials have demonstrated that intensification of Asparaginase (ASP) treatment in ALL can contribute to improved outcome. In adult ALL few data are availabe and optimal ASP preparation, schedule and intensity with respect to efficacy and tolerability have to be defined. The optimisation of ASP treatment is therefore an essential aim of the GMALL. Treatment: Induction treatment of the ongoing study 07/2003 consists of dexamethasone, vincristine, daunorubicine, pegylated asparaginase (PEG-ASP) (phase I), mercaptopurine, cyclophosphamide and cytarabine (phase II) as previously described (Brueggemann et al, Blood 2006: 107; 1116). During the study the dose for PEG-ASP was increased from 1000 to 2000 U/m2 in induction and from 500 to 2000 U/m2 in consolidation (combined with HDMTX and MP) for pts aged between 15 and 55 years. 1 application for high risk and 7 applications for standard risk (SR) were scheduled during the first year and the aim was improvement of overall survival (OS) and remission duration (RD). Patients: From more than 100 centers in Germany 1226 pts with a median age of 35 (15-55) yrs were evaluable. 826 pts were treated with 1000 U/m2 (cohort 1) and 400 pts with 2000 U/m2 (cohort 2) and both groups were comparable regarding major entry criteria. The analysis was restricted to pts who received one of the scheduled PEG-ASP doses during induction. Outcome: CR rate after induction was 91% vs 91% in cohort 1 and 2 resp., with comparable rates for early death (4% vs 5%) and failure (5% vs 4%). Data on molecular response (MRD below 10−4) after induction are available in a subset and showed no difference between both cohorts after induction (79% vs 82%). OS after 3 years was improved in cohort 2 (60% vs 67%; p>.05). The positive effect was specifically evident in SR patients (N=407 vs 190) with respect to OS (68% vs 80%; p=.02) and RD (61% vs 74%; p=.02). It was demonstrated in younger pts (15-45 yrs) (71% vs 82%; p=.02) and older pt (45-55 yrs) (56% vs 74%; p>.05). Excellent results were achieved in young adults (15-25 years) with respect to OS (77% vs 86%; p>.05) and RD (60% vs 78%; p>.05). Toxicity: The analysis of toxicity was focused on grade III-IV events during induction with potential correlation to PEG-ASP (764/382 pts in cohort 1/cohort 2)). Incidences are as follows: GOT or GPT (30%/30%), bilirubine (10%/16%), thrombosis (5%/5%) and hypersensitivity (<1%/<1%). In a subset of pts additional AEs were assessed as amylase (5%/13%), lipase (23%/15%) and glucose (10%/12%). Significantly less toxicity was observed during consolidation cycles. Bilirubine °III/IV occurred median 16d after PEG-ASP during phase II of induction. In univariate analysis it was correlated to dose (10% vs 16%; p=.004), age <> 45 yrs (11% vs 17%; p=.005), BMI <> 30 (12% vs 18%; p=.04) and rituximab application (11% vs 18%; p=.009). Hepatomegaly, infections or imatinib application had no significant effect. In multivariate analysis dose and age remained independent significant prognostic factors. Bilirubine increase during induction was associated with treatment delays and inferior prognosis. Conclusions: This is the largest cohort of adult ALL treated with PEG-ASP. Due to prolonged activity fewer applications are required which is a pre-requisite for realisation of ASP intensification in the context of an intensive multidrug chemotherapy for adult ALL. Although CR rate and molecular CR were not significantly improved PEG-ASP intensification was associated with an improved OS and RD. The improvement was specifically evident in SR pts treated with up to 7 doses of PEG-ASP. Overall intensified PEG-ASP was feasible. The rate of grade III-IV bilirubine elevation increased after dose escalation and led to treatment delays in individual pts which were prognostically relevant. It would be an important goal to identify parameters to predict severe ASP related toxicity. Further intensification of ASP by additional applications would be of interest. Supported by Deutsche Krebshilfe 70–2657-Ho2 and partly BMBF 01GI 9971 and Medac GmbH. Disclosures: Goekbuget: Medac: Consultancy, Research Funding, Speakers Bureau. Hoelzer: Medac: Speakers Bureau.

Abstract. EURAD, the European Joint Programme on Radioactive Waste Management (RWM), is the European Research Programme on RWM, aimed at supporting member states with the implementation of their national programmes. It brings together over 100 organisations from different backgrounds and countries, which work together in RD&amp;D projects, Strategic Studies and Knowledge Management (KM). The importance of KM is recognised by EURAD and reflected in a number of activities. One essential activity is the capture of the current State-of-Knowledge in the field of RWM and its transfer to the implementation of the different national programmes. This is done by different types of Knowledge Documents that are made available through a dedicated IT tool (e.g. a Wiki). The development of the individual EURAD KM documents is performed by recognised experts. These experts will share their view on the most relevant knowledge on a specific topic, highlighting safety functions and operational aspects. Additionally, signposting to pre-existing documents is performed (State-of-the-Art Documents, Scientific Papers, etc.). The hierarchy of the works for the KM documents (Theme Overview, Domain Insight, State-of-Knowledge, Guidance) is closely linked to the generic EURAD Roadmap/GBS (Goals Breakdown Structure). It provides a hierarchical structure that facilitates definition, organisation and communication of topics. All of this allows knowledge to be captured and presented with the level of detail that is required by the end-user, from a broad overview down to an increasing level of detail (pyramid of knowledge). To ensure the quality and consistency of the documents with the overall EURAD KM approach, quality assurance and editorial procedures are applied. Collection of end-user feedback will aid the optimisation and further development of the KM activities. To facilitate the transfer of knowledge, the EURAD KM programme goes beyond documents and strives to facilitate exchange between people and signpost to other resources, such as Training and Mobility activities (also organised by EURAD Work Package 13 Training &amp; Mobility) or Communities of Practice. All these activities will contribute to a useful and end-user-friendly EURAD KM programme that is designed to be operational well beyond the runtime of EURAD-1. This presentation will provide further insight into the approaches, status of work and an outlook on future activities that will support member states with the implementation of their national programmes.

AbstractIntroductionThis retrospective planning study aimed to evaluate the role of bolus in achieving dose uniformity in the ankles and feet in paediatric patients undergoing Modulated Arc Total Body Irradiation (MATBI) treatment and to identify patient factors that may negate or warrant its use.MethodsThe clinically treated plans of 20 paediatric patients who received MATBI treatment utilising ankle and foot bolus (Bolus plan) were compared with two retrospectively generated plans; a plan with bolus removed and no re‐optimisation (No Bolus plan), and a re‐optimised plan without bolus attempting to achieve equal dosimetry to the clinical plan via monitor unit adjustment (MU plan). Descriptive statistics were used to evaluate the dose uniformity criteria of ±10% coverage of the reference dose (RD) for each subregion of the ankle and foot for the three plans. The impact of patient height, weight, and age at the time of treatment was evaluated using Spearman's correlation.ResultsVariation in doses >10% RD was minimal across the three plans, with an average D1cc difference < 0.4Gy. For the ankle and foot regions in the Bolus plans, the volume receiving at least 90% of the RD (V90) was on average > 92%. In No Bolus and MU plans, there was an average reduction of 24.5% and 23.2% V90 coverage respectively in the toes. Spearman's correlation suggests height has the strongest relationship to D1cc.ConclusionThis study validated the continued use of ankle and foot bolus to achieve dosimetric goals for paediatric MATBI treatments, particularly V90 coverage across all heights.

Intravascular stents of various designs are currently used to prop open diseased arteries and there is evidence that different stent geometries have different in-stent restenosis rates. The majority of commercially available stents are designed generically to fit all individuals. Recent advances in imaging and catheter technologies, however, allow measurement of lesion shape and stiffness. Incorporating patient specific data into the stent design process could enable the development of customised stents. Considering the variety of lesion types, it is envisaged that better outcomes will be achieved if a stent is custom designed in such a way that it has variable radial stiffness longitudinally to hold the varying pressure of plaque and healthy artery at the same time while maintaining an acceptable lumen diameter. This type of operation is suitable for topology optimisation potentially allowing for optimal material distribution of a stent. The primary aim of this research is to develop new stent designs for a set of plaque types and investigate the final radius of the lumen after stent implantation. Stent geometries were obtained by topology optimisation for minimised compliance under different stenosis levels and plaque materials. Three types of stenosis levels by area, i.e. 30%, 40% and 50% with each type having three different plaque material properties i.e. calcified, cellular and hypocellular were studied. The optimisation results were transformed to clear design concepts and their performance was evaluated by implanting them in their respective stenosed artery types using finite element analysis. The results were compared with a generic stent in similar arteries, which showed that the new designs showed less recoil. In the hardest (calcified) of plaques studied, topology optimised designs overall resulted in 2%, 2% and 6% residual area stenosis compared to 10%, 29% and 35% from the generic design in arteries with 30%, 40% and 50% stenosis respectively. It was shown that higher material distribution resulted in the central region of the stent in order to resist implantation recoil due to higher plaque compressive loads. Additive manufacturing (AM) was utilised to validate the computational approach used in this thesis. This work provides a proof of concept for stents tailored to specific lesions in order to minimise recoil and maintain a patent lumen in stenotic arteries.

En juillet 2020, la nouvelle norme de codage vidéo, appelle Versatile Video Coding (VVC), a été publiée par le groupe Joint Video Experts Team (JVET). Cette norme permet un niveau plus élevé de polyvalence avec une meilleure performance en compression vidéo par rapport à son prédécesseur, High-Efficiency Video Coding (HEVC). En effet, elle introduit plusieurs nouveaux outils de codage tels que les modes de prédiction intra à granularité plus fine (IPMs) et la division QuadTree Multi-type Tree (QTMT). Étant donné que la recherche des meilleures décisions de codage est généralement précédée par l’optimisation du coût en distorsion et débit binaire, l’introduction de nouveaux outils de codage ou l’amélioration des outils existants nécessite des calculs supplémentaires. En fait, la norme VVC est 31 fois plus complexe que la norme HEVC. Par conséquent, cette thèse vise à réduire la complexité de calcul de la norme VVC et plus particulièrement au niveau des outils de prédiction Intra. Elle étudie en premiers lieu les opportunités de réduction de la complexité dans la décision du mode intra de la norme VVC. Puis, deux algorithmes rapides de décision de mode de prédiction intra basé sur des modèles d’apprentissage automatique telles que les réseaux de neurones convolutifs multi-tachés et l’arbre de décision LightGradient Boosting Machine (Light-GBM) ont été proposés
In July 2020, the new video coding standard Versatile Video Coding (VVC), was released by the Joint Video Expert Team (JVET). This standard enables a higher level of versatility with a better compression performance compared to its predecessor, High Efficiency Video Coding (HEVC). Indeed, it introduces several new coding tools such as finer-granularity Intra prediction Modes (IPMs), and nested Multi-type Tree (QTMT) and finer-granularity Intra Prediction Modes (IPM). Because finding the best encoding decisions is usually preceded by optimizing the Rate Distortion (RD) cost, introducing new coding tools or enhancing existing ones would require additional computations. In fact, the VVC is 31 times more complex than the HEVC. Therefore, the aim of this thesis is to reduce the computational complexity of the VVC. First, it studies the upper bound of complexity reduction in the intra mode decision of the VVC. Then, proposes two fast decision algorithms for the intra mode decision based on machine learning algorithms such as Multi-Task Learning (MTL) and Light-Gradient Boosting Machine (Light-GBM) were proposed