A hydrodynamic-numerical model of the river Rhine [online]

Abstract During the last centuries the river Rhine underwent a major regulation process which separated the river­bed from its flood plains and reduced the available areas for flooding. The river was straightened and the consequence is the discharge conditions were strongly changed and many recorded flood events were occurred. Serious floods at the river Rhine in 1993 and 1995 resulted in the policy "Room for the Rivers" and in 1998 in the "Action Plan Flood Defence" by the International Commission for Protection of the Rhine (ICPR). The "Action Plan Flood Defence" aims at improving the protection of people and goods against flood while integrating ecological improvements of the Rhine and its flood plains. Targets include the enlargement of flood plains through dyke displacement, the protection of valuable flood plains and flood plain restoration. Further targets are the re­connection of the rivers backwaters, the restoration of hydrological and ecological interactions between river and flood plains and the restoration of the riparian zone. Changing criteria for flood retention areas will altogether contribute towards a more natural river landscape with a higher flood regulation capacity and larger biodiversity. In order to quantitatively assess the effectiveness of flood plain restoration measures on flood regulation, the hydrodynamic­numerical model for the whole Rhine of the free flowing section is constructed. It consists of a 500 km long section of the Rhine River, starting at Maxau, the first gauging station of the free flowing section of the Upper Rhine, and ending at Lobith, the hydrology gauge at the border between Germany and the Netherlands. The important main tributaries of the Rhine (Neckar, Main, Nahe, Lahn, Mosel, Ahr, Sieg, Ruhr and Lippe) are also included in this model; the contribution from the Murg is considered at the gauge Maxau. The hydrodynamic­numerical model (HN­Model) of the river Rhine and its flood plain areas has the ability to predict the response of the river to imposed change. These obtained scenarios are of use to make political decisions and for the common understanding of the role of the wetlands on flood regulation. Furthermore, it is also useful for many different engineering works: The HN­Model is required for the design of flood control structures and for the assessment of impacts of alternative dyke configurations and flood retention options on the water level. And last but not least, the results obtained from the HN­Model are the boundary conditions for 2­D and 3­D numerical models and physical models and they are also one of the very important data for GIS applications on water resources management. Altogether, the HN­Model of the river Rhine gives a clear understanding on how the river adjusted to previous designs and plan implementations. The HN­Model of the river Rhine is based on the computer software CARIMA, developed by SOGREAH (Prof. Cung, France). Since 1963, it has already been used successfully for the large­scale Mekong delta mathematical model (in Vietnam) and for many other large rivers on the World. At the Institute for Water Resources Management and Agricultural Engineering, University of Karlsruhe, CARIMA is used for the projects of dyke replacements at the Lower Rhine with very good practical results. This model was expanded, in order to be able to assess the effects of different flood retention measures (polder) on the flood discharge at the Lower Rhine. Here is the different effect between free flowing polder and controlled polder. Moreover the model for the Upper Rhine and Middle Rhine was extended and it included an optimization of the control works. Now a mathematical model of the entire Rhine distance downstream of the barrage Iffezheim is existing, with that the effects of construction measures on the discharge of floodwater can be determined. Kurzfassung Während der letzten Jahrhunderte wurden am Oberlauf des Rheins gravierende Regulierungsmaßnahmen vorgenommen, die zu einer harten Trennung des Flussbetts und des Vorlandes und zu einer Reduzierung der Überflutungsgebiete führten. Dies hat zur Folge, dass sich seither die Abflussverhältnisse stark verändert haben und viele Hochwasserereignisse verzeichnet werden. Nach den schwerwiegenden Hochwässern von 1993 und 1995 wurden die Initiative "Räume für Flüsse" und der "Aktionsplan Hochwasser" der "Internationalen Kommission zum Schutze des Rheins" (IKSR) ins Leben gerufen. Letzterer zielt auf die Verbesserung des Schutzes von Anwohnern von Fließgewässern und Bauwerken vor Hochwasser, verbunden mit einer Verbesserung des Ökosystems des Rheins und seiner Vorländer, ab. Ziele sind die Vergrößerung der Vorländer durch Verlegung der Deiche, der Schutz der noch vorhandenen Rückhalteräume und die wieder Nutzbarmachung zuvor abgetrennter Überflutungsflächen. Weitere Ziele sind der Wiederanschluss von Altrheinarmen an den Hauptstrom, die Wiederherstellung des hydrologischen und ökologischen Austauschs zwischen dem Rhein und den Vorländern und die Instandsetzung der riparianen Zone. Die veränderten Rahmenbedingungen werden letztenendes zu einer natürlicheren Flusslandschaft mit einer größeren Vielfalt an Flora und Fauna und zu einer besseren Hochwasserregulierung führen. Um die Auswirkungen einer Rückgewinnung von Rückhalteräumen auf Hochwasserereignisse quantitativ nachzuweisen, wurde ein hydrodynamisch­numerisches Modell für den gesamten freifließenden Rhein erstellt. Es besteht aus einem 500 km langen Teilabschnitt des Rheins von Maxau, dem ersten Pegel des freifließenden Oberrheins, bis Lobith, dem hydrologischen Pegel an der Grenze zwischen Deutschland und der Niederlande. Die wichtigsten Nebenflüsse des Rheins (Neckar, Main, Nahe, Lahn, Mosel, Ahr, Sieg, Ruhr und Lippe) wurden ebenfalls in dieses Modell mit einbezogen; der Zufluss aus der Murg wird beim Pegel Maxau mit berücksichtigt. Das hydrodynamisch­numerische Modell (HN­Modell) des Rheins und seiner Vorländer erlaubt die Vorhersage des Verhaltens des Flusses bei einer Veränderung der äußeren Gegebenheiten. Die daraus resultierenden Szenarien sind vorausetzung, um politische Entscheidungen treffen zu können und um ein allgemeines Verständnis des Einflusses von Vorländern auf die Hochwasserregulierung zu erhalten. Weiterhin ist das HN­Modell für viele Ingenieuranwendungen von Nutzen: Es wird für die Planung von Bauwerken zur Hochwasserrückhaltung und für die Bewertung der Auswirkungen von alternativen Deichverläufen und Rückhaltegebieten benötigt. Die Ergebnisse dieses Modells werden auch Rahmenbedingungen für 2­ und 3­dimensionale numerische Modelle, physikalische Modelle und wichtige Daten für GIS­gestützte Anwendungen für die Wasserwirtschaft liefern. Insgesamt gesehen gibt das HN­Modell des Rheins einen genauen Aufschluss über die Auswirkungen vergangener und zukünftiger wasserbaulicher Maßnahmen. Das HN­Modell des Rheins basiert auf der Computersoftware CARIMA, entwickelt von SOGREAH (Prof. Cunge, Frankreich). Seit 1963 wurde dieses Programm bereits erfolgreich für viele große Flussmodelle weltweit eingesetzt, wie zum Beispiel für das umfangreiche mathematische Modell des Mekongdeltas in Vietnam. Am Institut für Wasserwirtschaft und Kulturtechnik der Universität Karlsruhe wird CARIMA bei Projekten für Deichrückverlegungen am Niederrhein mit sehr guten Ergebnissen für die Praxis eingesetzt. Dieses Modell wurde erweitert, um die Auswirkungen unterschiedlicher Hochwasserrückhaltemaßnahmen (Polder) auf den Hochwasserabfluss am Niederrhein abschätzen zu können. Hierbei wurde zwischen Flutpoldern und gesteuerten Poldern unterschieden. Des weiteren wurde das Modell auf den Oberrhein und Mittelrhein erweitert und eine Optimierung der Steuerung einbezogen. Nunmehr steht ein mathematisches Modell zu Verfügung mit dem Auswirkungen von Baumaßnahmen auf den Hochwasserabfluss in der gesamten Rheinstrecke unterhalb der Staustuffe Iffezheim berechnet werden können

Poverty Targeting and Impact of a Governmental Micro-credit Program in Vietnam

It is argued that without collateral the poor often face binding borrowing constraints in the formal credit market. This justifies a micro-credit program, which is operated by the Vietnam Bank for Social Policies to provide the poor with preferential credit. This paper examines poverty targeting and impact of the micro-credit program. It is found that the program is not very pro-poor in terms of targeting. Among the participants, the non-poor account for a larger proportion of loans. The non-poor also tend to receive larger amounts of credit compared to the poor. However, the program has positive impact on poverty reduction of the participants. This positive impact is found for all the three Foster-Greer-Thorbecke poverty measures.Micro-credit, poverty, poverty targeting, impact evaluation, instrumental variables, fixed-effect model

Potential pathogenicity and antimicrobial resistance of Escherichia coli from pig and poultry feces on-farm and carcasses at the abattoir in Vietnam

E. coli avec potentiel zoonotique pourrait éclore dans les réservoirs porcins et avicoles. Cette étude consiste à examiner la présence de souches E. coli porteuses de gènes virulents associés aux STEC (E. coli producteurs de Shiga-toxines), EPEC (E. coli entéropathogène), et ExPEC (E. coli pathogène extra-intestinal) chez les porcs et volailles élevés au Vietnam. Des prélèvements d’excréments et de carcasses ont été effectués dans des fermes et abattoirs porcins et avicoles sélectionnés où les animaux ont été suivis de l’élevage à l’abattage. Un total de 13,1% des souches, toutes sources confondues, ont été catégorisées comme potentiellement contaminées par ExPEC, possédant un ou plusieurs gènes de virulence iucD, tsh, papC et cnf. Peu d’isolats d’autres pathotypes ont été observés. Tous les gènes de virulence ExPEC, à l’exception de cnf, ont été identifiés plus fréquemment dans les isolats de fèces et carcasses avicoles que dans les isolats porcins. Même constatation pour le groupe du phylogénétique D. Une multirésistance aux médicaments a été régulièrement observée chez les deux isolats ExPEC. Les isolats de fèces de volailles ont souvent été associés à une résistance à l’acide nalidixique et à la ciprofloxacine (P<0.05), de même qu’au gène blaTEM, alors que les gènes qnr et aac(6’)-Ib ont peu été rencontrés des deux côtés. Cette étude démontre que les isolats ExPEC avicoles sont potentiellement plus pathogèniques que ceux porcins et que les isolats ExPEC de carcasses porcines et avicoles peuvent provenir de leurs excréments par la contamination associée au processus d'abattage. Ainsi, la volaille, particulièrement, serait un facteur de transmission de souches ExPEC zoonotiques.Zoonotic potential pathogenic Escherichia coli could arise from poultry and pig reservoirs. The aim of this study is to investigate the occurrence of E. coli strains carrying virulence genes associated with STEC (Shiga toxin-producing E. coli), EPEC (Enteropathogenic E. coli), and ExPEC (Extraintestinal pathogenic E. coli) in pigs and poultry on-farm and at abattoirs in Vietnam. Samples of feces and carcasses were collected at selected pig and poultry farms and abattoirs, in which animals were traced from farms to the abattoir. A total of 13.1% strains from all sources were classified as potential ExPEC, possessing one or more virulence genes iucD, tsh, papC and cnf. Few isolates of other pathotypes were observed. All ExPEC virulence genes, except cnf, were more frequently found in isolates from poultry than in isolates from pigs. A higher proportion of ExPEC isolates belonging to phylogenetic group D was observed in poultry. Multi-drug resistance was frequently observed in ExPEC isolates from both pigs and poultry. Nalidixic acid and ciprofloxacin resistance were significantly associated with poultry feces isolates (P<0.05). blaTEM gene was more frequently associated with poultry isolates, whereas qnr and aac(6’)-Ib genes were present at low prevalence in pig and poultry isolates. This study demonstrates that poultry ExPEC isolates are potentially more pathogenic than pig ExPEC isolates, and ExPEC isolates in pig and poultry carcasses may originate from pig and poultry feces, due to contamination associated to slaughtering process. Thus, meats particularly from poultry, might be a vehicle for transmission of zoonotic ExPEC strains

Applying the Unified Theory of Acceptance and Use of Technology (UTAUT) in Investigating Online Impulsive Buying Behavior of Vietnamese Consumers

Based on The Theory of Adoption and Use of Technology (UTAUT) (Venkatesh et al., 2003), this study builds a research model regarding the Factors affecting Vietnamese consumers' online impulsive buying behavior. The multiple regression results reveal that Performance Expectancy, Effort Expectancy, Social Influence, and Online Buying Intention play a crucial role in amplifying the development of online impulsive buying behavior in Vietnam. Keywords: buying behavior, online buying, impulsive buying behavior, compulsive buying behavior, UTAUT, Vietnam DOI: 10.7176/EJBM/13-6-19 Publication date:March 31st 2021

Sustainable Symbiotic Relationship in The Human Ecosystem in The Development of Public Spaces (Case of Hanoi Historical Inner-City Area)

In the last few years, the concept of the Human Ecosystem has been mentioned a lot frequently in Urban Environments related to social and natural ecosystems. The organization of public spaces cannot help but affect the relationships between human and natural ecology, economy, and culture. Perhaps the human activities have compromised the ecosystem so those relationships can be easily broken down. But it can also be enriched, or recovered from failures by establishing Symbiotic Relationships between natural, economic, and cultural elements in urban ecosystems. The research presents theoretical issues of Human Ecosystems in public space organization and specific applications in the case of Hanoi historical inner-city areas. It focuses on discussing theories of the structure and morphology of Human Ecosystems, the human behavior, the relationship between community behaviors, natural environment, and architecture of public spaces, to organize, enrich, and balance the service ecosystem of public spaces. These features are considered vital by the author in contributing to the preservation of natural resources, urban architectural heritage, creating architectural spaces and planning of public spaces towards ecological and green urban development

The Impact of FDI, International Trade, and National Economy on People’s Standard of Living in ASEAN Countries

This research paper analyzes the impact of foreign direct investment (FDI), international trade, and national economy on the standard of living of people in ASEAN member countries, using data from 2012-2021. The study uses data from this period to examine the effects of these variables on the standard of living in ASEAN member countries. The results indicate that international trade and national economy have a significant influence on people's standard of living in the region. However, the effect of FDI varies depending on the level of development of the country. While FDI doesn't have much effect on developing countries, it has a negative impact on developed countries. The study also provides insights for policymakers on how to promote economic growth and improve the quality of life for people in the ASEAN. Keywords: FDI, international trade, national economy, the standard of living, ASEAN DOI: 10.7176/EJBM/15-6-10 Publication date:March 31st 2023

DIFFICULTIES IN WRITING ESSAYS OF ENGLISH MAJORED SOPHOMORES AT TAY DO UNIVERSITY, VIETNAM

Writing skill is an important part of communication, which helps people express ideas, experiences, and feeling exactly. Good writing skill allows them to communicate their message with clarity and ease to a far larger audience than through face-to-face or telephone conversations. However, students often face some difficulties when writing. This survey research presents the process of the study of “Difficulties in writing essays of English majored sophomores at Tay Do University”. It was conducted to find out some difficulties in learning writing of 53 sophomores from 12A and 12B classes at Tay Do University. The questionnaire, interview questions, and essay samples were instruments of this research. The results showed that sophomores had many difficulties in writing essays such as vocabulary, grammar structures, idea arrangement, background knowledge, and others. Basing on the research results, students could recognize their difficulties and find ways to overcome them. Article visualizations

Do Corporate Social Responsibilities Support Its Financial Performance? Evidence of the Listed Firms in Vietnam

In the latest decades, corporate social responsibilities (CSR) are incrementally noticed in emerging countries regarding to the surge of globalization and the advance of social concerns. However, there exist opposing arguments on how CSR practices influence a firm’s financial performance (CFP), either in theoretical or empirical perspectives, causing many managers’ hesitation in CSR engagement. This study, therefore, examines the impacts of CSR on CFP, considering the individual effect of each CSR endeavor by using the data from listed firms’ financial statements during the period 2015-2019 and panel regression analysis methods. The findings reveal inconstant effects of different CSR activities on CFP. Specifically, a firm’s fulfillment of shareholders’ and customers’ interests contributes to raise its profitability, while its engagement in the benefits of employees and creditors causes a reduction in financial returns. Interestingly, the correlations between firms’ responsibilies towards regulators and suppliers and CFP are statistically insignificant. Furthermore, we make pairwise marginal comparisons to identify the distinctions of CSR-CFP relations across industries. The results only indicate that listed firms in Utilities sector have the lower level of CSR intensity than those in Consumer Discretionary and Consumer Staples sectors. The implications and limitations are also discussed in this study

A Study on the Impact of the Usage of Cost Information on Business Performance of Enterprises in Vietnam

Purpose: The primary objective of the research was to investigate the correlation between the utilization of cost information and business performance of enterprises in Vietnam, particularly in the context of the Covid-19 pandemic.   Design/methodology/approach: A survey was conducted, involving a sample of 380 participants consisting of CEOs, CFOs, managers, board of directors, and individuals in charge of accounting and finance departments. The study employed a structure equation model to analyze the relationship between the use of cost information and business performance.   Findings: The study revealed a significant and positive impact of cost information utilization on business performance among the surveyed enterprises in Vietnam. Additionally, the study provided recommendations for enterprises in Vietnam on how to make use of cost information for various purposes, including planning, evaluating, decision-making, and cost control, to optimize their business performance.   Research, Practical &amp; Social implication: The study's results suggest that utilizing cost information effectively can lead to improved business performance and may provide valuable insights for Vietnamese enterprises on how to navigate the challenging and competitive post-Covid-19 economic environment.   Originality/value: The research employed a structural equation modeling (SEM) approach, and a test for univariate normality demonstrated an outstanding critical skewness ratio value. Furthermore, the kurtosis indicated that the data followed a normal distribution, making it suitable for analysis. Since SEM employs rigorous criteria to evaluate model fit, it can be inferred that the measurement model exhibited a high level of fit. The findings affirm the beneficial impact of utilizing cost information on business performance and offer significant recommendations for Vietnamese businesses in the current post-COVID era

Evaluation of Asaoka and Hyperbolic Methods for Settlement Prediction of Vacuum Preloading Combined with Prefabricated Vertical Drains in Soft Ground Treatment

This study evaluated the use of the Asaoka and hyperbolic methods to estimate the ultimate settlement of soft ground treated by vacuum preloading combined with prefabricated vertical drains. For this aim, a large-scale physical laboratory model was constructed. The model was a reinforced-tempered glass box containing a soil mass with dimensions of 2.0 × 1.0 × 1.2 m (length × width × depth). Physical models of this scale for the same purpose are rare in the literature. The soil was taken from a typical coastal region in Dinh Vu Hai Phong, Vietnam. The surface settlement near and between the two drains was measured right after the vacuum preloading started. Important properties of the soil were tested to evaluate the effectiveness of the treatment method. The measured settlement was used in the Asaoka and hyperbolic methods to predict the potential ultimate settlement. The results showed the superiority of the vacuum consolidation approach in improving fundamental engineering properties of soft soil. Furthermore, the ultimate settlement predicted by both methods showed a good agreement with the measured value, proving that the Asaoka and hyperbolic methods are suitable for the estimation of the ultimate settlement of soft soil treated with vacuum consolidation