Quantum Periods For Certain Four-Dimensional Fano Manifolds

We collect a list of known four-dimensional Fano manifolds and compute their quantum periods. This list includes all four-dimensional Fano manifolds of index greater than one, all four-dimensional toric Fano manifolds, all four-dimensional products of lower-dimensional Fano manifolds, and certain complete intersections in projective bundles

Excess Air Ratio Management in a Diesel Engine with Exhaust Backpressure Compensation

The paper investigates the operation of a wideband universal exhaust gas oxygen (UEGO) sensor in a diesel engine under elevated exhaust backpressure. Although UEGO sensors provide the excess air ratio feedback signal primarily in spark ignition engines, they are also used in diesel engines to facilitate low-emission combustion. The excess air signal is used as an input for the fuel mass observer, as well as to run the engine in the low-emission regime and enable smokeless acceleration. To ensure a short response time and individual cylinder control, the UEGO sensor can be installed upstream of a turbocharger; however, this means that the exhaust gas pressure affects the measured oxygen concentration. Therefore, this study determines the sensor’s sensitivity to the exhaust pressure under typical conditions for lean burn low-emission diesel engines. Identification experiments are carried out on a supercharged single-cylinder diesel engine with an exhaust system mimicking the operation of the turbocharger. The apparent excess air measured with the UEGO sensor is compared to that obtained in a detailed exhaust gas analysis. The comparison of reference and apparent signals shows that the pressure compensation correlations used in gasoline engines do not provide the correct values for diesel engine conditions. Therefore, based on the data analysis, a new empirical formula is proposed, for which the suitability for lean burn diesel engines is verified.© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

POSSIBILITIES OF PHOSPHORUS RECOVERY FROM REJECT WATERS, SEWAGE SLUDE AND ASHES AFTER THERMAL SEWAGE SLUDGE TREATMENT

W ostatnich latach zaobserwowano rosnącą świadomość o ograniczonych zasobach fosforu. Szacuje się, że mogą one ulec wyczerpaniu w ciągu 100 lat, przy obecnym zaawansowaniu technologii. Ponad 80% wydobywanego złoża wykorzystywane jest do produkcji nawozów sztucznych oraz w przemyśle chemicznym. Taka perspektywa zwiększa zainteresowanie recyklingiem fosforu, który może być odzyskiwany ze ścieków w fazie płynnej, z odwodnionych osadów ściekowych oraz z fazy stałej z popiołów po termicznym przekształcaniu osadów ściekowych. Popioły powstałe w wyniku monospalania osadów ściekowych charakteryzują się najwyższą zawartością fosforu oraz największym potencjałem odzysku wynoszącym ponad 90%. Celem niniejszej pracy jest przegląd aktualnych metod odzysku fosforu. Przeprowadzona analiza metod służących do odzysku fosforu pozwala stwierdzić, iż każda z nich wymaga dalszych badań i udoskonalania zachodzących procesów, a wybór konkretnej metody uzależniony jest od wielu czynników.In recent years a growing awareness about the limited resources of phosphorus has been observed. It is estimated that they may be exhausted within 100 years, assuming the current level of technological advancement. More than 80% of the deposits is used for the production of fertilizers and in the chemical industry. This perspective increases the interest in the recycling of phosphorus, which may be recovered from effluent, dehydrated sewage sludge and from ashes after thermal conversion of sewage sludge. Ashes, as a result of sewage sludge thermal treatment, are characterized by the highest content of phosphorus and the highest recovery potential of over 90%. The aim of this paper is to present an overview of the current methods of phosphorus recovery. The analysis of methods for recovery of phosphorus shows that each of them requires further research and improvement of the processes, and the choice of a particular method depends on many factors

BioMart: a data federation framework for large collaborative projects

BioMart is a freely available, open source, federated database system that provides a unified access to disparate, geographically distributed data sources. It is designed to be data agnostic and platform independent, such that existing databases can easily be incorporated into the BioMart framework. BioMart allows databases hosted on different servers to be presented seamlessly to users, facilitating collaborative projects between different research groups. BioMart contains several levels of query optimization to efficiently manage large data sets and offers a diverse selection of graphical user interfaces and application programming interfaces to ensure that queries can be performed in whatever manner is most convenient for the user. The software has now been adopted by a large number of different biological databases spanning a wide range of data types and providing a rich source of annotation available to bioinformaticians and biologists alike

Few smooth d-polytopes with n lattice points

We prove that, for fixed n there exist only finitely many embeddings of Q-factorial toric varieties X into P^n that are induced by a complete linear system. The proof is based on a combinatorial result that for fixed nonnegative integers d and n, there are only finitely many smooth d-polytopes with n lattice points. We also enumerate all smooth 3-polytopes with at most 12 lattice points. In fact, it is sufficient to bound the singularities and the number of lattice points on edges to prove finiteness.Comment: 20+2 pages; major revision: new author, new structure, new result

Incorporating thermoelectric power plant water use into multi-objective optimal power flow

Traditionally, power systems have been operated to minimize cost while maintaining reliability. However, extreme weather and demand events can affect traditional thermoelectric power generation operations due to their reliance on water for cooling. This paper contributes a novel multi-objective formulation of the optimal power flow (OPF) problem where cost, water withdrawal, and water consumption are minimized. Through this formulation, we assign optimization weights to water withdrawn and consumed, which can be directly incorporated into existing OPF formulations. We apply this formulation with a global mapping sensitivity analysis to a realistic case study to first demonstrate its general effectiveness under extreme climatic, hydrologic, and operational scenarios. Then, we apply a global ranking sensitivity analysis to determine the most influential generators for system performance. Through this operational scenario analysis framework, analysts can gain insights into potential system-level and component-level vulnerabilities within power systems. Such insights can be useful for informing both short-term operations as well as long-term power system planning.</p

Research needs for optimising wastewater-based epidemiology monitoring for public health protection

Wastewater-based epidemiology (WBE) is an unobtrusive method used to observe patterns in illicit drug use, poliovirus, and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The pandemic and need for surveillance measures have led to the rapid acceleration of WBE research and development globally. With the infrastructure available to monitor SARS-CoV-2 from wastewater in 58 countries globally, there is potential to expand targets and applications for public health protection, such as other viral pathogens, antimicrobial resistance (AMR), pharmaceutical consumption, or exposure to chemical pollutants. Some applications have been explored in academic research but are not used to inform public health decision-making. We reflect on the current knowledge of WBE for these applications and identify barriers and opportunities for expanding beyond SARS-CoV-2. This paper critically reviews the applications of WBE for public health and identifies the important research gaps for WBE to be a useful tool in public health. It considers possible uses for pathogenic viruses, AMR, and chemicals. It summarises the current evidence on the following: (1) the presence of markers in stool and urine; (2) environmental factors influencing persistence of markers in wastewater; (3) methods for sample collection and storage; (4) prospective methods for detection and quantification; (5) reducing uncertainties; and (6) further considerations for public health use

The Next Frontier: Making Research More Reproducible

Science and engineering rest on the concept of reproducibility. An important question for any study is: are the results reproducible? Can the results be recreated independently by other researchers or professionals? Research results need to be independently reproduced and validated before they are accepted as fact or theory. Across numerous fields like psychology, computer systems, and water resources there are problems to reproduce research results (Aarts et al. 2015; Collberg et al. 2014; Hutton et al. 2016; Stagge et al. 2019; Stodden et al. 2018). This editorial examines the challenges to reproduce research results and suggests community practices to overcome these challenges. Coordination is needed among the authors, journals, funders and institutions that produce, publish, and report research. Making research more reproducible will allow researchers, professionals, and students to more quickly understand and apply research in follow-on efforts and advance the field