1,722,358 research outputs found
[Halle (Saale), Universitäts- und Landesbibliothek Sachsen-Anhalt, Morbio 2 (94)]
No full textMantenutus Rofi, genannt Sechinus, aus Commessaggio Inferiore, belehnt seinen Bruder Blasimus Rofi mit Land in Commessaggio Inferiore.Handschrift DE-3, GND 2024680-8, Signatur: Morbio 2 (94)Die Illustrationen sind: NotarszeichenÜberlieferungsart: originalBeschreibstoff: PergamentErhaltungszustand: gutHandschriftUrkund
Regions of fresh water influence: The influence of depth on a ROFI
No full textThe topic of this paper is the study of the tidal velocity profiles within a region of fresh water influence (referred to as ROFI in this paper). These regions of fresh water influence occur where rivers discharge fresh water into salty seas. The main research question is how depth influences the behaviour of the tidal velocity profile in a region of fresh water influence. The approach for this investigation is to apply a model to two different ROFI systems, and compare the results. The first system considered is the Rhine ROFI, for which numerous field data have been collected (Simpson, et al. 1993) and a numerical model has been created (de Boer, Pietrzak and Winterwerp 2006). The second system is the Fraser ROFI in Canada, having similar tidal characteristics as the Rhine ROFI (Foreman, et al. 1995), but a much larger depth. The model used for this comparison is an analytic model, based on Prandle (Prandle 1982a). In order to do so, it was first necessary to understand the complex behaviour of the tidal velocity profile of the Rhine ROFI. The big difference between the behaviour for neap and spring tide can be explained by decomposing the tidal velocity vector into two counter rotating phasors. Also, two parameters turned out to be important: the depth-averaged velocity and the eddy viscosity. As second goal, and main objective of this paper, was to study the impact of the depth on the behaviour of the tidal velocity profile in the region of fresh water influence. This was done by comparing the shallow Rhine ROFI with the much deeper Fraser ROFI. It turned out that finding realistic values for the eddy viscosity coefficient was the biggest challenge. The ability of predicting vertical current profiles may serve many applications, such as offshore construction or oil leaks. Being able to apply this model to other ROFI’s around the world with different depths, is therefore a very useful aim.Environmental FluidmechanicsHydraulic EngineeringCivil Engineering and Geoscience
Modelling the wind-driven motions in the Rhine ROFI
No full textThis Master Thesis presents a numerical model analysis of the response of the Rhine ROFI on wind direction and speed. The aim of this study is to gain a further insight in the physical processes of the Rhine ROFI. Previous work on the Rhine ROFI focused mostly on tidal effects (straining and mixing) and inertial motions (earth rotation). Other studies have focussed on the response of freshwater plumes to wind forcing alone. Recently, the combined forcing has been studied in an idealised model of the Rhine ROFI. The current study extends this research, however with the incorporation of the actual bathymetry and coastline of the Netherlands in a new, state-of-the-art three-dimensional hydrodynamic model. A sensitivity analysis of the number and distribution of vertical layers in the model found that 48 vertical layers is recommended under strongly stratified conditions The numerical results show that the effect of earths rotation on the wind-drive flow plays an important role in the stratification of the Rhine ROFI. Under neap tide conditions the Rhine ROFI exhibits periods of stratification. Due to a reduced eddy viscosity at the pycnocline in between, the surface layer responds more independently and is less affected by bottom friction. It implies that Coriolis force becomes relatively more important in the dynamics of the surface layer. Differential advection and depth mean advection make the size and shape of the freshwater plume highly variable. If the system is forced by an upwelling-favourable wind the freshwater plume is transported offshore, resulting in an increase of stratification. Downwelling-favourable winds transport the freshwater landwards, which results in a vertically well-mixed water column. An increased magnitude of the wind causes a more stratified water column for the upwelling-favourable winds and a more mixed state for the downwelling-favourable winds. Direct wind-induced vertical mixing of the plume is observed for an increased magnitude of the wind. The integrated potential energy anomaly is presented. It is found to be a powerful tool in analysing the interaction and competition of the wind and the ebb-flood tidal cycle in mixing and straining of the Rhine ROFI. The mixing and straining by the ebb-flood tidal cycle is found to be dominant over the mixing and straining by the wind. The influence of the wind on the Rhine ROFI is however clearly observed. The spatial changes in the potential energy anomaly show that for upwelling-favourable winds an increase of stratification occurs in the far-field. In the near-field a decrease is observed. For downwelling-favourable winds the opposite happens. The influence of the Ekman dynamics is observed in the results. For increased downwelling-favourable winds a reduction of the potential energy anomaly is found in both the near- and far-field of the Rhine ROFI.Environmental Fluid DynamicsHydraulic EngineeringCivil Engineering and Geoscience
Should CYP2D6 be genotyped when treating with tamoxifen? [Letter in reply]
No full textLetter in regards to: Del Re M, Rofi E, Citi V, Fidilio L, Danesi R. Should CYP2D6 be genotyped when treating with tamoxifen? Pharmacogenomics 17(18), 1967-1969 (2016). In response to: Damkier P. Don't think twice it's all right: tamoxifen and CYP2D6 genotyping in the treatment of breast cancer patients. Pharmacogenomics 18(8), XXX (2017)
Modelling the Rhine ROFI on a non-straight coast
No full textAdditional thesis - The Rhine river outflow has a major impact on the North Sea in front of the Dutch coast. It creates the Rhine ROFI (region of freshwater influence), a very complex three-dimensional volume of water with a relatively low salinity. Many researches have been conducted on this phenomenon. Now another complex factor is added: a non-straight coastline. The specific case of the Sand Engine, a sandbar-shaped peninsula in front of the Holland coast, is studied. The objective is to identify changes in the Rhine ROFI caused by the Sand Engine and their possible causes. Simpson (Simpson, et al., 1993) and De Boer (2008) have identified several mechanisms influencing the shape and size of the Rhine ROFI. The major ones are: the deflection of the fresh water jet from the river Rhine through the Coriolis force towards the north forming a ‘coastal river’ of fresh water, advection due to tidal propagation, density currents as a consequence of horizontal density gradients, tidal straining and tidal mixing. Fortnightly and semidiurnal variations of velocities and stratification can be expected within the Rhine ROFI. Signell (1989) has had major contributions to the understanding of tidal propagation around coastal headlands. In his work a categorization is made for different combinations of tidal conditions and headland shapes. Within this categorization the Sand Engine is seen as a rather small and streamlined headland. Flow separation may be expected with a stagnant lee-side eddy forming each tidal period. These researches cover the main domain of interest of this thesis. An extension is made by exploring the baroclinic effects of the perturbation of the coast to the Rhine ROFI. For this purpose a numerical model was set up. In essence the original model De Boer used in his dissertation was applied. The Sand Engine was added as a blunt rectangular shape at the same distance from the river mouth as in reality. No numerical problems were found after adapting the model. The performance of the model was successfully verified by comparing time-averaged salinity distributions to figures in De Boer’s work. The Rhine ROFI and the ‘coastal river’ remain largely unchanged, comparing outcomes of the models with and without the Sand Engine. On a more detailed scale some interesting phenomena can be distinguished. During both neap and spring tide a fresh water feature forms ahead of high tide at the location of the Sand Engine. The offset of the fresh water feature has a barotropic origin, being generated by a strong current at the southwest corner of the Sand Engine. Under neap tide conditions this fresh water feature grows in the offshore direction, whereas this does not occur for spring tide conditions. This offshore advection is a baroclinic effect as such widespread offshore velocities involved with the offshore advection of fresh water were not found under barotropic conditions. A possible explanation of the offshore velocities is the strength of the tidal straining effect, being enforced by the stronger vertical density gradient when the fresh water is located at the Sand Engine. Tidal mixing is larger under spring conditions, preventing tidal straining from happening, explaining why offshore-directed velocities and subsequent offshore fresh water advection are not found in the results. In this thesis a simplified approach has been applied. Therefore the results must be treated with care under the likely possibility that flow mechanisms have been altered, enhanced or ruled out. However, the results do show the likely importance of baroclinic effects. These effects may have large consequences on the hydrodynamics in the area surrounding the Sand Engine. Therefore it is recommended to perform additional research on this topic.Civil Engineering and GeosciencesHydraulic EngineeringCIE5050-0
Internal gravity waves in the Rhine ROFI: Applicability of the KdV model
No full textThe Rhine Region of Fresh Water Influence (ROFI) is a shallow frictional river plume in front of the Dutch coast. Each tidal cycle a new tidal plume front with fresh-water is released. Recently, internal gravity waves have been observed in this plume. Using a Froude number analysis, support for the internal wave generation mechanism by a tidal plume front is found. It is shown, that on averaged neap tides the density stratification is large. This results in a larger area where the internal waves can be released from the tidal plume fronts compared to spring tides. As the Rhine ROFI is located in shallow water, it is investigated what the effect of bathymetry variation is on internal waves. This is studied by extending the standard KdV model derivation to account for a variable bed. This resulted in a small correction on the propagation speed inside the KdV equation. Observations of internal waves have been used to validate the KdV model. By scaling analysis of the observed waves it is obtained that the relative wave height and relative depth balance for most of the observed events. For these events the wave period and velocity amplitude of the KdV model are well matched with the measurements. This showed that the KdV model may be used for a first estimate of internal waves in the Rhine ROFI. By developing a TGE fitting procedure, it was possible to obtain the pycnocline depth and the direction of wave propagation with only limited data available. Therefore, the parameters have been varied and the error between the TGE solution and the velocity potential obtained from the velocity measurements has been minimized.Double degree Master of Science in Applied Mathematics and Civil Engineerin
Hydrodynamics in the mid-field plume region of the Rhine ROFI
No full textRiver plumes, also regions of freshwater influence , are important features to understand because of their impact on the current structure, stratification and the transport of fine sediments, nutrients and contaminants. One important river plume is the Rhine ROFI. Prior studies have sought to understand far-field dynamics where cross-shore straining is dominant (Simpson & Souza, 1995; Souza & Simpson,1995; De Boer et al., 2008). However, less is known about the mid-field region of this river plume, where fronts matter as well. Here we use field observations from a 6 week measurement campaign in fall 2014 to investigate the dynamics of the mid-field region of het Rhine ROFI. We will focus on the interaction between far-field processes, such as tidal straining, and near field processes, such as fronts. The Rhine ROFI is of interest because the Dutch coast has been modified by extending the Port of Rotterdam and the construction of the Sand Engine that extends into the southern North Sea. These perturbations might impact the currents, the ROFI and the distribution of fine sediment, nutrients and contaminants. Therefore, the understanding of this is of importance. During September and October 2014, a large field observational campaign was conducted off the Dutch coast close to the sand Engine, 10 km north of the river outflow. Measurements were made at two locations, 2 and 5.5 km offshore (see Figure 1). Moorings, with Conductivity Temperature Depth (CTD) and Optical Backscatter (OBS) instruments at different depths, were deployed to obtain vertical profiles of salinity and suspended sediment concentrations (SSC). In addition, at each location a bottom-mounted Acoustic Doppler Current Profiler (ADCP) measured vertical velocity profiles. Radar images of the area were used to gain surface information, specifically about frontal propagation in the vicinity of the measurement locations. The weather conditions were highly variable during the six week period. There were very calm periods, but also storms, which completely destroyed stratification. The wind direction changed during the campaign as well. In addition to the data, numerical modelling with a 3D hydrostatic model will be used to gain information of the entire mid-field plume.Environmental Fluid Mechanic
STRATEGI PROMOSI DALAM MENINGKATKAN JUMLAH PELANGGAN DI BENGKEL ROFI MOTOR AHASS 12163 PALEMBANG
Get PDFStrategi PromosiDalamMeningkatkan Jumlah Pelanggan di Bengkel Rofi Motor AHASS 12163 Palembang. Tujuandaripenelitianadalahuntukmengetahui strategi promosi apa yang tepat untuk Bengkel Rofi Motor AHASS 12163 Palembang dalammeningkatkan Jumlah Pelanggan. Metodepengumpulan data yang digunakan adalah wawancara, studipustaka, dan data sekunder yang diperolehdari Bengkel Rofi Motor AHASS 12163 Palembang.Padalaporanini, penulismembahas promosi yang adapadaBengkel Rofi Motor AHASS 12163 Palembang, yaitu dengan menggunakan periklanan bermedia seperti spanduk dan brosur, dan non bermedia seperti penjualan perorangan dan promosi penjualan.Kekurangan promosi menggunakan spanduk yaitu bahannya mudah rusak dan brosur terkadang orang malas membacanya apabila bentuknya tidak menarik. Dan promosi non bermedia melalu penjualan perorangan promosi penjualan tidak ada sales promotion sendiri dari pihak bengkel solusi menurut penulis untuk spanduk menggunakan bahan yang tidak mudah rusak, Brosur membuat layout semanarik mungkin, penjualan perorangan sebaiknya menambah staff khusus untuk bagian sales promotion yang dapat digunakan oleh Bengkel Rofi Motor AHASS 12163 Palembang dalam mencapai target jumlah pelanggan Bengkel Rofi Motor AHASS 12163 Palembang harus menyediakan staff khusus untuk sales promotion diharapkan dapat meningkatkan jumlah pelanggan dan volume penjualan dari Bengkel Rofi Motor AHASS 12163 Palembang
Ahmad Rofi Suryahadikusumah's Quick Files
No full textThe Quick Files feature was discontinued and it’s files were migrated into this Project on March 11, 2022. The file URL’s will still resolve properly, and the Quick Files logs are available in the Project’s Recent Activity
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