Incorporation of Carbon-based Nanoparticles in Ultrafiltration Membranes to Remove Steroid Hormone Micropollutants

Mikroverunreinigungen (insbesondere Steroidhormone) sind besorgniserregende Verbindungen in Oberflächengewässern und Abwässern, die zu einem erhöhten Risiko für Probleme mit dem Fortpflanzungssystem, Herz-Kreislauf-Erkrankungen und Krebs beim Menschen führen. Die Membrantechnologie ist eine gute Lösung, um diese Verbindungen zu entfernen, aber die effektiven Behandlungen (Nanofiltration und Umkehrosmose) sind kostspielig, da viel Energie erforderlich ist, um den Druck auf 5 bis 60 bar zu erhöhen. Ultrafiltration (UF) ist eine kostengünstigere Lösung und kann in Verbindung mit adsorptiven Materialien eine gute Entfernung von Steroidhormonen ermöglichen. Die Möglichkeit, diese Mikroverunreinigungen mit adsorptiven Komposit-Membranen zu entfernen, ist das Hauptziel dieser Doktorarbeit. In solchen adsorptiven Komposit-Membranen ist die hydraulische Verweilzeit von Wasser und gelösten Stoffen kurz (unter einer Minute), im Gegensatz zu den Verweilzeiten (oder Kontaktzeiten) in Adsorbern oder Kontaktoren mit Aktivkohle. Außerdem gibt es bei solchen kompakten Membranen eine Kapazitätsgrenze (das ist die maximale Menge an Adsorptionsmittel pro Membranmenge). Daher müssen die Adsorptionsmittel im Vergleich zu Aktivkohle eine ausreichend große äußere Oberfläche haben, um die Stoffaustauschlimitierung zu minimieren. Kohlenstoffbasierte Nanopartikel (CNPs), wie mehr-/einwandige Kohlenstoff-Nanoröhren (MW-/SWCNTs), Graphen, Graphenoxid und Fulleren, sind vielversprechende Materialien für den Einbau in die UF-Membran. Eine hohe Oberfläche und ein guter Stoffaustausch garantieren jedoch keine gute Adsorption. Bei vertikal ausgerichteten Kohlenstoff-Nanoröhren (VaCNT)-Membranen erreicht das Hormon sofort die Wand der Poren mit nahezu idealer zylindrischer Form und weniger Tortuosität. Diese Membran adsorbiert sehr wenig Hormon, was durch die Kräfte erklärt werden kann, die auf das Hormonmolekül an der Oberfläche einwirken. Die Ziele sind es, die drei Hauptaspekte mit Komposit-Membranen zu untersuchen, die die Hormonadsorption bestimmen, nämlich i) Oberflächeneigenschaft des Adsorptionsmittels (Kapitel 4), ii) Stoffaustauschlimitierung bei kurzen Verweilzeiten (Kapitel 5) und iii) Zusammenspiel der Kräfte (Kapitel 7). Kapitel 6 untersucht weiter die Behinderung des Stoffaustausches, die durch organische Stoffe verursacht werden

Understanding Type IV pilus-mediated secretion in Vibrio cholerae

Bacterial pathogens depend on the expression of virulence factors that aid host infection. A mechanistic understanding of bacterial virulence can provide insights into novel antimicrobial targets and therapies. One virulence factor is Type IV pili (T4P), long thin filaments found on bacterial surfaces with roles in adhesion, DNA uptake and exoprotein secretion. The T4P system is closely related to the Type II secretion (T2S) system where periplasmic “pseudo-pili” exhibit a piston-like motion for exoprotein export. My research aims to understand T4P-mediated exoprotein secretion in the simple T4P system of Vibrio cholerae. I show that the exoprotein’s flexible N-terminal segment is the export signal, which may bind to minor pilin at the pilus tip for delivery across the secretin channel

An Empirical Test of the Fama-French Five-Factor Model: Applicability to Equitized State-Owned Enterprises in Vietnam

Research Objectives – Asset pricing is one of the most popular topics in financial economics that has been studied for decades as various theories and models were established in this field. However, most of these studies were conducted for the markets in the United States or other developed countries, which can have questionable implications in the emerging and frontier markets. Thus, this thesis aims to fill the research gap by selecting Vietnam’s stock market as the market of interest. Besides, this thesis also explores a special segment pertaining to the market: equitized state-owned enterprises (SOEs) by investigating the relationship between average stock returns and state-ownership status. With respect to the model of interest, this thesis will focus on the Fama-French five-factor model and its relative performance to others including the Capital Asset Pricing Model (CAPM) and the Fama-French three-factor model. The underlying rationale for this selection is that the five-factor is a recent model, which was first introduced in 2015, and since then there have been mixed results from empirical tests of this model across different markets. Therefore, there emerges a need to conduct research on this topic, especially for a developing and under-researched market like Vietnam. Data & Methodology – The thesis will examine monthly returns of common stocks listed on both Ho Chi Minh Stock Exchange and Hanoi Stock Exchange from July 2009 to December 2017, 102 months in total. The sample will be rebalanced annually in June from 2009 to 2017. The sample size amounts to 620 companies after the last rebalance in June 2017. Asset pricing tests will be implemented to investigate the explanatory performance of each model by regressing excess returns of test portfolios on factor returns. Besides, the factor spanning tests will help to determine whether any factor in the five-factor model is redundant by regressing each of the five factors on the other four. All regressions will be conducted using the ordinary least squares (OLS) method. Main Findings – Regarding asset pricing tests, all models fare worst in 12 value-weighted test portfolios formed from size and state capital. Specifically, the lethal portfolio for all tested models except CAPM contains large stocks of firms with low state capital (state owns more than 0% and less than 50% of charter capital). The average adjusted R2s of the CAPM, the three-factor model, and the five-factor model are respectively 45.6%, 69.8%, and 70.6%. Regarding the factor redundancy issue, High-Minus-Low (HML) is not a redundant factor in this empirical test. Instead, Robust-Minus-Weak (RMW) and Conservative-Minus-Aggressive (CMA) appear to be the potential candidates. In general, this thesis provides a cautious support for the superiority of the five-factor model over the CAPM and the three-factor model after assessing a combination of criteria. It is important to view the superiority of the five-factor model with caution since differences in performance between it and the three-factor model are hardly noticeable in many cases. Furthermore, despite its superior performance, the five-factor model cannot fully capture average returns in Vietnam’s stock market as it fails when test portfolios are formed from state capital, which is not explicitly targeted by design

On A Multi-Dimensional Singular Stochastic Control Problem: The Parabolic Case

This dissertation considers a stochastic dynamic system which is governed by a multidimensional diffusion process with time dependent coefficients. The control acts additively on the state of the system. The objective is to minimize the expected cumulative cost associated with the position of the system and the amount of control exerted. It is proved that Hamilton-Jacobi-Bellman’s equation of the problem has a solution, which corresponds to the optimal cost of the problem. We also investigate the smoothness of the free boundary arising from the problem. In the second part of the dissertation, we study the backward parabolic problem for a nonlinear parabolic equation of the form u_t + Au(t) = f (t, u(t)), u(T ) = ϕ, where A is a positive self-adjoint unbounded operator and f is a Lipschitz function. The problem is ill-posed, in the sense that if the solution does exist, it will not depend continuously on the data. To regularize the problem, we use the quasi-reversibility method to establish a modified problem. We present approximated solutions that depend on a small parameter \epsilon \u3e 0 and give error estimates for our regularization. These results extend some work on the nonlinear backward problem. Some numerical examples are given to justify the theoretical analysis

Enhanced study of complex systems by unveiling hidden symmetries with Dynamical Visibility

One of the great challenges in complex and chaotic dynamics is to reveal its deterministic structures. These temporal dynamical structures are sometimes a consequence of hidden symmetries. Detecting and understanding them can allow the study of complex systems even without knowing the full underlying mathematical description of the system. Here we introduce a new technique, called Dynamical Visibility, that quantifies temporal correlations of the dynamics based upon some symmetry conditions. This visibility measures the departure of the dynamics from internal symmetries. We apply this technique to well-known chaotic systems, such as the logistic map and the circle map, as well as to experimental data from a diode laser with optical feedback and external modulation. Our results show the robustness of the method in characterizing dynamics and highlighting transitions in the dynamical behavior of a complex system. We envision that this can be a useful tool in experimental data, as it can extract key features of the deterministic laws that govern the dynamics of a system, despite the lack of knowledge of those specific quantitative descriptions

Bayesian forward modeling of galaxy clustering

With the future large-scale structure (LSS) surveys being on the horizon, precision cosmology is seeing a unprecedented opportunity to constrain cosmological parameters and differentiate cosmological models. Such opportunities naturally bring also unparalleled challenges -- specifically in the form of understanding, examining and, especially, combining various datasets. Bayesian forward modeling and inference, in this context, provides a consistent and transparent framework to extract information from separate datasets while accounting for multiple systematic sources. This thesis is a dedicated effort to bring this framework one step closer to being ready for the upcoming challenges posed by high-precision Cosmic Microwave Background (CMB) experiments and large-volume galaxy redshift surveys. We systematically examine the constraining power of the Bayesian forward modeling approach to galaxy clustering on both cosmological and astrophysical observables, namely the initial conditions of our Universe, the clustering amplitude of galaxies and the kinematic Sunyaev-Zel'dovich (kSZ) effects of galaxy clusters. While the first two focus only on halo clustering in N-body simulation, the last one brings together observational datasets from separate experiments and surveys: the Planck CMB experiment, the Sloan Digital Sky survey (SDSS) and the maxBCG cluster catalog, which include both common and different sources of systematics. We find in chapter 5 that the Bayesian forward inference approach is able to, on large scales, recover up to ~90% the input initial conditions of the GADGET-2 simulation using halos identified in the same simulation as tracers. The framework is robust regarding to choices of gravitational forward model for the matter density fields and deterministic bias model for tracers. The LSS likelihood, on the other hand, might play an important role for unbiased inference of not only the initial conditions, but also the cosmological parameters. This is demonstrated in chapter 7, where we are able to recover the input $\sigma_8$ of the same simulation with systematic error under ~10%, using a Fourier-space likelihood derived from the effective field theory (EFT) approach to LSS with rigorously controlled theoretical systematics. In chapter 6, we use results from the Bayesian forward reconstruction of the BOSS/SDSS3 volume to measure the large-scale bulk flow and kSZ signal of maxBCG catalog. We find evidence of the kSZ effect at approximately 2-sigma, consistently in individual- as well as multi-scale measurements. Our reported signal-to-noise is the first to include uncertainties from the velocity reconstruction in this type of measurement.Die großräumige Struktur des Universums (large-scale structure, LSS) erlaubt uns, dank neuer, größerer Himmelsdurchmusterungen, immer präzisere Vermessungen der Geschichte des Universums und Tests von kosmologischen Modellen. Die immer größeren und genaueren Datensätze stellen uns allerdings auch vor Herausforderungen in der Analyse und insbesondere Kombination von verschiedenen Datensätzen. Vorwärts-Modellierung (forward modeling) und Inferenz im Rahmen der Bayes'schen Statistik bieten für diesen Zweck einen konsistenten Rahmen, der auch die Einbeziehung von systematischen Effekten erlaubt. Die vorliegende Dissertation zielt darauf ab, dieses statistische Modell und seine Implementierung im BORG-Code einen Schritt näher an die tatsächliche Anwendung auf aktuelle und zukünftige Datensätze zu bringen, insbesondere für den kosmichen Mikrowellenhintergrund (cosmic microwave background, CMB) und für spektroskopische Galaxiendurchmusterungen (galaxy redshift surveys). Die Inferenz von sowohl kosmologischen als auch astrophysikalischen Parametern wird systematisch untersucht: erstens die Anfangsbedingungen für die Struktur im Universum, das heisst die Verteilung der kleinen Dichtefluktuationen im frühen Universum, und zweitens der kinematische Sunyaev-Zel'dovich (kSZ) Effekt im CMB, der unter anderem von Galaxienhaufen hervorgerufen wird. Im ersteren Fall werden kosmologische N-Körper-Simulationen benutzt, während der kSZ-Effekt auf tatsächlichen Beobachtungsdaten gemessen wird: die CMB-Messungen des Planck-Satelliten, die Galaxienverteilung der Sloan Digital Sky Survey (SDSS), und der Galaxienhaufenkatalog maxBCG. Entscheidend sind hier eine sorgfältige Behandlung der spezifischen und gemeinsamen systematischen Effekte der verschiedenen Datensätze. In chapter 5 zeige ich, dass das Bayes'sche Vorwärts-Modell im \borg{}-Code in der Lage ist, die Anfangsbedingungen zu ca. 90% korrekt zu rekonstruieren. Dies gilt auf großen Skalen für verschiedene Vorwärts-Modelle für das Dichtefeld sowie für den Galaxienbias. Was kosmologische Parameter angeht, wie die Amplitude des linearen Dichtefeldes $\sigma_8$, spielt die Form der Wahrscheinlichkeitsfunktion (likelihood) für das Galaxienfeld eine wichtige Rolle. Dies wird in chapter 7 demonstriert, wo ich zeige, dass eine Wahrscheinlichkeitsfunktion im Fourier-Raum eine Inferenz des Parameters $\sigma_8$ innerhalb eines systematischen Fehlers von 10% erlaubt. Diese Wahrscheinlichkeitsfunktion kann im Rahmen der effektiven Feldtheorie (effective field theory, EFT) für LSS hergeleitet werden. In chapter 6 benutze ich dann die BORG-Rekonstruktion basierend auf der SDSS/BOSS Galaxiendurchmusterung, um den kSZ-Effekt um Galaxienhaufen aus dem maxBCG-Katalog (der das gleiche Volumen umfasst) zu messen. In diesem Fall benutze ich die Rekonstruktion, um die Pekuliargeschwindigkeiten der Galaxienhaufen zu schätzen, die nicht direkt beobachtbar sind. Ich finde Hinweise auf ein kSZ-Signal mit etwa 2-sigma Konfidenz, sowohl in der Messung auf bestimmten Winkelskalen wie auch in der Kombination von Messungen auf verschiedenen Skalen. Diese Messung und ihr Fehlerbalken sind die ersten kSZ-Messungen, die die Unsicherheiten in der Schätzung der Geschwindigkeiten berücksichtigen

Spiritual factors in Vietnamese consumers' purchasing decisions

Consumer demand is a complex and dynamic phenomenon that exerts a profound influence on economic decision-making, market trends, and overall societal well-being. In this context, comprehending the determinants of consumer demand assumes paramount significance for various stakeholders, including businesses, policymakers, and scholars. Furthermore, the acknowledgment of spiritual factors as influential determinants in shaping the values and behaviors of a population introduces a nuanced dimension, particularly within culturally diverse societies such as Vietnam. This research endeavor seeks to engage with these pivotal dimensions by elucidating the role of spiritual factors in tandem with the determinants of consumer demand, with specific reference to the distinctive cultural milieu of Vietnam. Employing a comprehensive multidimensional methodology, encompassing qualitative interviews, surveys, quantitative data analysis, historical and cultural inquiries, logical reasoning, and empirical case studies, this study strives to unravel the intricate interplay between spirituality and consumer behavior. It aims to explicate the influence of deeply ingrained spiritual beliefs, firmly entrenched within Vietnamese culture, on various spheres of decision-making. These spheres span from the observance of auspicious birth rituals and naming conventions to the orchestration of significant life events and the valuation of high-value assets such as real estate and automobiles. Moreover, this research seeks to illuminate the enduring nexus between spirituality, cultural heritage, and the choices made by consumers. It endeavors to provide insights into the multifaceted dynamics governing decision-making processes within the Vietnamese context. Additionally, this inquiry extends its purview to the exploration of the economic implications and marketing strategies predicated upon spiritual underpinnings, underscoring the substantial role played by these spiritual beliefs in shaping the consumer landscape. Ultimately, this research aspires to furnish a holistic comprehension of how spirituality is interwoven into the fabric of daily existence in Vietnam, significantly molding the values and behaviors of its citizenry

Study On Horseradish (Armoracia Rusticana) Essential Oil And Comparison With The Related Species – Debreceni Horseradish (Armoracia Macrocarpa).

Armoracia rusticana G. Gaertn., B. Mey. & Scherb. (commonly known as horseradish) is well known for the irritating, pungent smell and bitter taste. In Hungary, horseradish has been cultivated and used extensively in food industry, as well as in traditional medicine. Characteristic smell, taste and possible pharmacological effects comes from the plant' s essential oil. Developing essential oil extracting technology is not only proved to be useful for economical purpose, but also for scientific research due to the high content of isothiocyanate, a potential anti-carcinogenic agent present in the essential oil. Therefore, this study starts with the development of oil extracting technology, first in laboratory-scaled and then medium-scaled distillation. The efficiency of the new technology is taken under investigation by examining the yield of extracted oil, the completion of extraction process and the quality (content) of essential oil. Although there have been studies on horseradish’s isothiocyanates content, at the moment of this study, there has been no analytical investigation on neither isothiocyanate, glucosinolate profile nor the enzymatic activities in horseradish cultivated in Hungary. The analytical study starts with gas chromatography and mass spectrometry analysis on horseradish essential oil in order to reveal the full profile of horseradish isothiocyanates, which was compared to data collected from literature after for checking the quality of the extracted oil. The second part of the analytical study concentrates on development of the novel capillary electrophoresis method for instantly separation and detection of isothiocyanates and their parent molecules (glucosinolates) as well as revealing activity of myrosinase enzyme on the conversion of glucosinolates into isothiocyanate. Armoracia macrocarpa (Waldst. & Kit.) Baumg. or Debreceni horseradish, is the relative species of Armoracia rusticana. Debreceni horseradish has been used for condiment purpose and known as “sweet radish”. Unlike its famous relative, there is neither information on Armoracia macrocarpa' s phytochemistry, anatomical structure nor enzymatic activities. The final part of this study gives the comparison on glucosinolate contents (by liquid chromatography and mass spectrometry), anatomical structure (by cross sections) and enzymatic activities (by gel electrophoresis and spectrophotometry) between Armoracia rusticana and Armoracia macrocarpa.N

Investigation on the effect of cross beams in single span bridges under dynamic aspect by using finite element method

In the 1980s and 1990s, most bridges in Vietnam employed simple beam for short-span river crossings that did not need navigation and mainly used the reinforced concrete T-beams or pre-stressed concrete. While the T-frame structure that has hang single span is widely applied for rivers that require navigation...The single girder is a basic span made of pre-stressed reinforced concrete T or I cross section, with spacing ranging from 2.2m to 2.6m, and the absence of diaphragms was a common feature of bridges built during this time period. All horizontal crashes almost have happened on the spans that did not have diaphragms. As a result, the impact force is concentrated mostly on the lateral girders, leading to total damage. Thus, researches to evaluate the effect of diaphragms in the distribution of horizontal impact forces as well as minimizing the damage in the span structures are crucial. This study focuses on simulating and studying the influence of the number and position of the diaphragms in terms of stress, deformation and damage when a collision occurs in order to propose additional and repair solutions to enhance the horizontal resistance of span

Secure Information Flow for IoT Applications

This paper discusses how to ensure security, i.e., confidentiality and integrity properties, for data in IoT applications. While confidentiality could be assessed via information flow analysis, integrity is ensured by error-correcting codes. In addition to errors, many communication channels also cause erasures, i.e., the demodulator cannot decide which symbol the received waveform represents. The paper proposes a method that might correct both errors and erasures together. Our method is efficient in reducing memory storage as well as decoding complexity