Qucosa: Hochschule für Technik und Wirtschaft Dresden
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Ridge Cultivation for the Adaption of Fodder Maize (Zea mays L.) to Suboptimal Conditions of Low Mountain Ranges in Organic Farming in Central Europe
Get PDFFodder maize cultivation under low mountain conditions in Central Europe presents obstacles for organic dairy farmers; low temperatures and high precipitation values in spring delay the juvenile development of maize, which leads to lower and fluctuating yields. Increasing the soil temperature during the critical growth phase of maize in spring is beneficial for maize cultivation. For this reason, 0.15 m high ridge-row cultivation (RCM) of maize was compared to a typical flat surface cultivation method (FCM) with 0.75 m row spacing in three environments (En) in 2017, 2018 and 2020 on-farm at low mountain sites in Germany. In the experiment, with randomised block design and one-factorial arrangement, soil temperature (ST) at 0.05 m soil depth at midday, field emergence (FE) 4, 8, 16 and 20 days after sowing (DAS), dry matter yields (DM) in every En and plant development and N, P, K content in En 2020 were investigated. RCM led to a significantly higher ST 4 DAS in every En, 12 and 20 days in 2018 and 8 and 16 DAS in 2020. RCM did not accelerate maize FE but positively impacted plant development and starch content. RCM generated a higher dry matter (DM) yield of whole maize plants and corn cobs, and a higher protein yield than FCM. RCM slightly increased the plant-available P and Mg content from 0 to 0.3 m and influenced significantly the mineral N content from 0 to 0.3 m at the beginning of grain development. RCM, a simple cultivation technique, demonstrated benefits for maize cultivation, particularly for climatically marginal locations in Germany
Argumente und Möglichkeiten für eine Quantifizierung und ein Monitoring der differenzierten Landnutzung
Get PDFThe concept of differentiated land use was formulated already 50 years ago to preserve biodiversity and to maintain or restore the necessary landscape structure. Although it has been anchored in the Federal Nature Conservation Act, there is still no monitoring of its implementation, although the German Advisory Council on the Environment has been calling for this for 25 years. The paper argues that the technical prerequisites for monitoring the differentiated land use are ready today and discusses the conceptual steps necessary. It identifies several dimensions and proposes corresponding indicators of landscape structure, in particular the degree of diversification and the mixing of intensive land uses, the distribution of the size of intensively used areas, the proportion of semi-natural areas (at least 10 %) and the interconnected arrangement of semi-natural areas. Furthermore, the paper discusses suitable reference units and existing data. Finally, we identify remaining gaps in the data basis and discuss the question of defining target values.Das Konzept der differenzierten Landnutzung wurde bereits vor 50 Jahren formuliert, um Biodiversität zu erhalten und die dazu erforderliche Landschaftsstruktur zu bewahren oder wiederherzustellen. Es ist zwar im Bundesnaturschutzgesetz verankert worden, aber es fehlt noch immer ein Monitoring seiner Umsetzung, obwohl der Sachverständigenrat für Umweltfragen dies seit 25 Jahren als notwendig einfordert. Der Beitrag argumentiert, dass die technischen Voraussetzungen für ein Monitoring der differenzierten Landnutzung heute bereitstehen, und diskutiert die dafür nötigen konzeptuellen Schritte. Es werden verschiedene Dimensionen bestimmt und entsprechende Indikatoren der Landschaftsstruktur vorgeschlagen, insbesondere zum Grad der Diversifizierung und der Durchmischung der intensiven Landnutzungen, zur Schlaggrößenverteilung intensiv genutzter Flächen, zum Flächenanteil naturnaher Flächen (mindestens 10 %) und zur vernetzten Anordnung der naturnahen Flächen. Des Weiteren diskutiert der Aufsatz geeignete Bezugseinheiten und vorhandene Daten. Abschließend werden verbleibende Lücken in den Datengrundlagen identifiziert und die Frage der Definition von Zielwerten erörtert
Application of electrostatic separation and differential scanning calorimetry for microplastic analysis in river sediments
Get PDFA method with the potential for comprehensive microplastic monitoring in river sediments is presented in this study. We introduce a novel combination of electrostatic separation, density separation, and differential scanning calorimetry (DSC). Currently, microplastic analysis in sediments is limited in terms of sample masses, processing time, and analytical robustness. This work evaluated a method to process large sample masses efficiently and still obtain robust results. Four particulate matrices, including commercial sands and river sediments, were spiked with PCL, LD-PE, and PET microplastic particles (63–200 µm). Samples with a mass of 100 g and 1,000 g (sand only) contained 75 mg of each microplastic. After electrostatic separation, the mass of sand samples was reduced by 98%. Sediment samples showed a mass reduction of 70–78%. After density separation, the total mass reduction of sediment samples was above 99%. The increased concentration of total organic carbon seems to have the highest impact on mass reduction by electrostatic separation. Nevertheless, the recovery of microplastic was independent of the particulate matrix and was polymer-specific. In 100 g samples, the average recovery rates for PCL, LD-PE, and PET were 74 ± 9%, 93 ± 9%, and 120 ± 18%, respectively. The recoveries of microplastic from 1,000 g samples were 50 ± 8%, 114 ± 9%, and 82 ± 11%, respectively. In scale up experiments, high recoveries of all microplastics were observed with a decrease in standard deviation. Moreover, the biodegradable polymer PCL could be used as an internal standard to provide quality assurance of the process. This method can overcome the current limitations of routine microplastic analysis in particulate matrices. We conclude that this method can be applied for comprehensive microplastic monitoring in highly polluted sediments. More studies on electrostatic separation and polymer-specific recovery rates in complex matrices are proposed
Impact of Overmodulation Methods on Inverter and Machine Losses in Voltage-Fed Induction Motor Drives
Get PDFThe modulation methods Space Vector PWM (SVPWM), Discontinuous PWM (DPWM1, DPWMMAX) and six-step mode are investigated in the overmodulation range of a voltage-fed induction motor drive. This area enables an increase of inverter output voltage so that drive performance can be enhanced. Though, pulse dropping occurs which results in increased iron losses and current waveform quality
degradation. Due to differences in harmonic distortion the modulation methods cause various torque oscillations and power losses in induction motors and inverter drives. To quantify these effects in a squirrel cage induction motor drive a simulation model containing a finite element machine model and an analytic inverter model is developed, in order to find the PWM scheme offering maximum torque and minimal power losses. Additionally, the holistic investigation of machine and inverter losses allows for making statements concerning total losses of drive systems and the most suitable overmodulation scheme for the application
Effects of Selective Dry Cow Treatment on Intramammary Infection Risk after Calving, Cure Risk during the Dry Period, and Antibiotic Use at Drying-Off: A Systematic Review and Meta-Analysis of Current Literature (2000–2021)
Get PDFThe objectives of this paper were (i) to perform a systematic review of the literature over the last 21 yr and (ii) to evaluate the efficacy of selective dry cow treatment (SDCT) vs. blanket dry cow treatment (BDCT) in dairy cows regarding the risk of intramammary infection (IMI) after calving, new IMI risk after calving, cure risk during the dry period, and a reduction in antibiotic use at drying-off by meta-analysis. The final number of included studies was n = 3 for IMI risk after calving and n = 5 for new IMI risk after calving, cure risk during the dry period, and antibiotic use. The relative risk (RR) levels for IMI, new IMI, and cure did not differ significantly between SDCT and BDCT. This meta-analysis provides evidence that SDCT seems to be an adequate alternative to BDCT regarding udder health with a simultaneous reduction in antibiotic use. Limitations might arise because of the small number of studies included.:1. Introduction
2. Material and Methods
2.1 Search Strategy
2.2 Study Selection
2.3 Data Extraction
2.4 Assessment of Bias Risk
2.5 Statistical Analysis
3. Results
3.1 Study Selection
3.2 Study Characteristics
3.3 Outcomes
3.4 Risk of Bias
3.5 Pairwise Meta-Analysis
3.6 Subgroup Meta-Analysis
4. Discussion
4.1 Risk of IMI after Calving
4.2 Risk of new IMI after Calving
4.3 Cure Risk during Dry Period
4.4 Antibiotic Use at Drying-Off
4.5 Strengths and LimitationsZiele dieser Studie waren (i) ein systematisches Review über die Literatur der letzten 21 yr zu erstellen sowie (ii) die Effizienz von selektivem Trockenstellen (SDCT) im Vergleich zu konventionellem Trockenstellen (BDCT) bei Milchkühen anhand von Risiko an intramammären Infektionen (IMI) post partum (pp), Neuinfektionenrisiko pp, Heilungsrisiko während dem Trockenstehen und Reduktion des Antibiotikaeinsatzes zum Trockenstellen mittels einer Meta-Analyse zu untersuchen. Die finale Anzahl eingeschlossener Studien war n = 3 für das IMI-Risiko pp sowie n = 5 für Neuinfektionenrisiko pp, Heilungsrisiko während dem Trockenstehen und Antibiotikaeinsatz zum Trockenstellen. Die relativen Risiken für IMI pp, Neuinfektionen pp und Heilung während der Trockenstehperiode unterschieden sich dabei nicht signifikant zwischen SDCT und BDCT. Diese Meta-Analyse erbringt Evidenz, dass SDCT eine adäquate Alternative zu BDCT im Hinblick auf Eutergesundheit und Antibiotikareduktion ist. Limitationen entstehen durch die geringe Anzahl an eingeschlossenen Studien.:1. Introduction
2. Material and Methods
2.1 Search Strategy
2.2 Study Selection
2.3 Data Extraction
2.4 Assessment of Bias Risk
2.5 Statistical Analysis
3. Results
3.1 Study Selection
3.2 Study Characteristics
3.3 Outcomes
3.4 Risk of Bias
3.5 Pairwise Meta-Analysis
3.6 Subgroup Meta-Analysis
4. Discussion
4.1 Risk of IMI after Calving
4.2 Risk of new IMI after Calving
4.3 Cure Risk during Dry Period
4.4 Antibiotic Use at Drying-Off
4.5 Strengths and Limitation
A phase field approach to trabecular bone remodeling
Get PDFWe introduce a continuous modeling approach which combines elastic response of the trabecular bone structure with the concentration of signaling molecules within the bone and a mechanism for concentration dependent local bone formation and resorption. In an abstract setting bone can be considered as a shape changing structure. For similar problems in materials science phase field approximations have been established as an efficient computational tool. We adapt such an approach for trabecular bone remodeling. It allows for a smooth representation of the trabecular bone structure and drastically reduces computational costs if compared with traditional micro finite element approaches. We demonstrate the advantage of the approach within a minimal model. We quantitatively compare the results with established micro finite element approaches on simple geometries and consider the bone morphology within a bone segment obtained from micro-CT data of a sheep vertebra with realistic parameters
A Novel Robust Approach for Computing DE-9IM Matrices Based on Space Partition and Integer Coordinates
Get PDFA novel approach for a robust computation of positional relations of two-dimensional geometric features is presented which guarantees reliable results, provided that the initial data is valid. The method is based on the use of integer coordinates and a method to generate a complete, gap-less and non-overlapping spatial decomposition. The spatial relationships of two geometric features are then represented using DE-9IM matrices. These allow the spatial relationships to be represented compactly. The DE-9IM matrices are based on the spatial decomposition using explicit neighborhood relations. No further geometric calculations are required for their computation. Based on comparative tests, it could be proven that this approach, up to a predictable limit, provides correct results and thus offers advantages over classical methods for the calculation of spatial relationships. This novel method can be used in all fields, especially where guaranteed reliable results are required.:Introduction
Related Research
Materials and Methods
Results
Discussion
Outlook
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
Abbreviations
Reference
Evaluierung und prototypische Realisierung von Algorithmen zur Kartografie von Innenräumen durch mobile Roboterplattformen
Get PDFIn der heutigen Zeit werden autonome Roboter in sehr vielen Bereichen eingesetzt. Wichtige Voraussetzungen für viele dieser Einsatzbereiche sind die Kartierung einer Umgebung sowie die autonome Navigation und Orientierung innerhalb dieser Karte. Dafür kann SLAM (Simultaneous Localization And Mapping) eingesetzt werden. Der Google Cartographer ist eine Software, die solche Funktionen bereitstellt. Diese Arbeit gibt zu Beginn einen grundlegenden Überblick über die vielseitigen Anwendungsgebiete und unterschiedlichen Funktionsweisen von SLAM. Im Weiteren wurden einzelne Algorithmen des Google Cartographers analysiert, sowie die Ergebnisse und deren Genauigkeit mit einem anderen SLAM Algorithmus verglichen. Weiterhin zeigt die Arbeit eine mögliche Anbindung des in C++ entwickelten Google Cartographers an Java über JNI (Java Native Interface). Abschließend wurden die Ergebnisse der Arbeit und der Nutzen der aus der Arbeit entstandenen Erkenntnisse und des entwickelten JNI ausgewertet.In today's world, autonomous robots are used in many areas. Important requirements for many of these fields of application are the mapping of an environment as well as autonomous navigation and orientation within this map. SLAM (Simultaneous Localization And Mapping) can be used for this purpose. The Google Cartographer is a software that provides such functions. At the beginning, this thesis gives a basic overview of the versatile application areas and different functionalities of SLAM. Furthermore, individual algorithms of the Google Cartographer were analyzed and results and accuracy were compared with another SLAM algorithm. Furthermore the thesis shows a possible connection of the Google Cartographers developed in C++ to Java over JNI (Java Native Interface). Finally, the results and the benefits of the knowledge, gained from the thesis and the developed JNI, were evaluated
Model-Based Prediction of an Effective Adhesion Parameter Guiding Multi-Type Cell Segregation
Get PDFThe process of cell-sorting is essential for development and maintenance of tissues. With the Differential Adhesion Hypothesis, Steinberg proposed that cellsorting is determined by quantitative differences in cell-type-specific intercellular adhesion strengths. An implementation of the Differential Adhesion Hypothesis is the Differential Migration Model by Voss-Böhme and Deutsch. There, an effective adhesion parameter was derived analytically for systems with two cell types, which predicts the asymptotic sorting pattern. However, the existence and form of such a parameter for more than two cell types is unclear. Here, we generalize analytically the concept of an effective adhesion parameter to three and more cell types and demonstrate its existence numerically for three cell types based on in silico time-series data that is produced by a cellular-automaton implementation of the Differential Migration Model. Additionally, we classify the segregation behavior using statistical learning methods and show that the estimated effective adhesion parameter for three cell types matches our analytical prediction. Finally, we demonstrate that the effective adhesion parameter can resolve a recent dispute about the impact of interfacial adhesion, cortical tension and heterotypic repulsion on cell segregation.Der Prozess der Zellsortierung ist für die Entwicklung und Erhaltung von Geweben unerlässlich. Mit der Differentiellen Adhäsionshypothese schlug Steinberg vor, dass die Zellsortierung durch quantitative Unterschiede in den zelltypspezifischen interzellulären Adhäsionsstärken bestimmt wird. Eine Umsetzung der Differentiellen Adhäsionshypothese ist das Differentielle Migrationsmodell von Voss-Böhme und Deutsch. In diesem wurde für Systeme mit zwei Zelltypen ein effektiver Adhäsionsparameter analytisch hergeleitet, der das asymptotische Sortiermuster vorhersagt. Die Existenz und Form eines solchen Parameters für mehr als zwei Zelltypen ist jedoch unklar. Hier verallgemeinern wir analytisch das Konzept eines effektiven Adhäsionsparameters für drei und mehr Zelltypen und zeigen numerisch seine Existenz für drei Zelltypen auf der Basis von in silico Zeitreihendaten, die von einem zellulären Automaten des Differentiellen Migrationsmodells erzeugt werden. Darüber hinaus klassifizieren wir das Segregationsverhalten mithilfe statistischer Lernverfahren und zeigen, dass der geschätzte effektive Adhäsionsparameter für drei Zelltypen mit unserer analytischen Vorhersage übereinstimmt. Schließlich zeigen wir, dass der effektive Adhäsionsparameter eine kürzlich aufgekommene Diskussion über den Einfluss von Grenzflächenadhäsion, Kortikalspannung und heterotypischer Abstoßung auf die Zellsegregation lösen kann
Oxidation of Selected Trace Organic Compounds through the Combination of Inline Electro-Chlorination with UV Radiation (UV/ECl2) as Alternative AOP for Decentralized Drinking Water Treatment
Get PDFA large variety of Advanced Oxidation Processes (AOPs) to degrade trace organic compounds during water treatment have been studied on a lab scale in the past. This paper presents the combination of inline electrolytic chlorine generation (ECl2) with low pressure UV reactors (UV/ECl2) in order to allow the operation of a chlorine-based AOP without the need for any chlorine dosing. Lab studies showed that from a Free Available Chlorine (FAC) concentration range between 1 and 18 mg/L produced by ECl2 up to 84% can be photolyzed to form, among others, hydroxyl radicals (OH) with an UV energy input of 0.48 kWh/m3. This ratio could be increased to 97% by doubling the UV energy input to 0.96 kWh/m3 and was constant throughout the tested FAC range. Also the achieved radical yield of 64% did not change along the given FAC concentration range and no dependence between pH 6 and pH 8 could be found, largely simplifying the operation of a pilot scale system in drinking water treatment. Whereas with ECl2 alone only 5% of benzotriazoles could be degraded, the combination with UV improved the degradation to 89%. Similar results were achieved for 4-methylbenzotriazole, 5-methylbenzotriazole and iomeprol. Oxipurinol and gabapentin were readily degraded by ECl2 alone. The trihalomethanes values were maintained below the Germany drinking water standard of 50 µg/L, provided residual chlorine concentrations are kept within the permissible limits. The here presented treatment approach is promising for decentralized treatment application but requires further optimization in order to reduce its energy requirements.:Introduction
Methodology
Results and Discussion
Conclusions
Author Contributions
Funding
Conflicts of Interest
Appendix A
Reference