Experimental work has been carried out with a hydraulic flow test rig in which flows of water up to 65 kgs-l can be measured with a weigh-tank and its diverter valve to an accurary of ± 0.2%. The nature of the experimental work has been to investigate the system pressure losses due to the components in line (i) For interference free flow; (ii) For interactions. The components used are 90 degree circular bends and orifice plates. Bends of radius ratios from R/D - 1.49 to 4.89 and nominally standard single-hole and multi-hole orifice plates of area ratios from m – 0.170 to 0.508 have been tested. To investigate the interaction effects arising from an orifice plate in proximity to bends, various bend-orifice plate (in a few instances orifice plate-bend) combinations have been arranged. The bore diameter of duct (or pipe) and bend is approximately D – 145.05 mm and tests have been performed for Reynolds numbers ranging from Re(D) – 0.7 x 105 to 6 x 10(5). In those instances in which results from the experimental work can be compared directly with published results, agreement is good. However, many of the experimental results, particularly the measurements of interactions between bends and orifice plates, are new.

Background: Knowledge translation models to address existing knowledge gaps in different areas of speech-language pathology practice are providing researchers and clinicians the opportunity to improve efficiency and effectiveness of service delivery. As a developing context, public health care in South Africa can scarce afford the luxury of wasting resources and finances on interventions that are inefficient or without proven benefit given the increasing prevalence of chronic burden of disease such as stroke and traumatic related injury, both of which has dysphagia as a symptom. The outcome of the manner, efficiency and consistency of traditional models of dysphagia management currently being implemented in this context were compared to a pre-existing theoretically proven free water protocol for dysphagia management. Method: The primary aim of the current study was to enable knowledge-to-action translation in dysphagia management by determining the feasibility of using a free water protocol for stroke or traumatic brain injured patients presenting with dysphagia in an acute government hospital setting in Gauteng, South Africa. A mouth care training protocol was developed for nurses as a component of the free water protocol. Nurse perceptions on the training and implementation of mouth care were explored. The quantitative aims investigated if there was a difference between traditional and free water management in terms of a) the occurrence of aspiration pneumonia, b) amount of water intake and c) length of hospitalisation. 139 Nurses and 46 patients with dysphagia were participants. A mixed method design was used. The study was conducted in two phases, phase one comprised the ethnography and the nurse training component. Phase two was quantitative and comprised implementation of the free water protocol by the researcher. Thematic content analysis was used for the qualitative data. Quantitative data was analysed using inferential statistics. Results: The mouth care training protocol for nurses was efficient and effective for the current context. Nurses engaged positively with the study by implementing mouth care successfully when necessary for the dysphagic patients. This combined with consistent daily management of dysphagia with patient involvement, facilitated patient compliance, adequate levels of water intake, with no cases of dehydration, and no incidence of aspiration pneumonia at the end of the intervention period. The comparison group in contrast who received the traditional model of dysphagia management showed longer period of hospitalisation and higher consumption of liquids despite recommendations for liquid restricted diets. There were seven cases of aspiration pneumonia at the end of the intervention period in the comparison group. Conclusions & Implications: Despite no statistically significant differences between the study and comparison groups on the specified outcome measures, clinically significant differences were noted. The method employed in the study seemed to facilitate knowledge translation of the free water protocol to a public hospital context in South Africa. The findings of the study suggested that a collaborative partnership between the speech-language pathologist and nurse was attainable and this seemed to have multifaceted mutual benefits to the patient, institution and the respective professions. Improved monitoring of service provision, implementation of protocols based on contextual evidence, importance of knowledge translation in a developing context and an expanded role of the speech-language pathologist responsive to the needs of the context and patient population were some of the implications that arose from the study.

BACKGROUND: White matter (WM) aberrations have been broadly characterized in schizophrenia using standard diffusion tensor imaging (DTI) techniques. The present study aims to distinguish WM alterations in the early course of schizophrenia using advanced diffusion measures of free-water corrected fractional anisotropy (FAt) and free-water fractional volume (FW), in addition to examining their association with neurocognition, social cognition, and clinical measures. We report baseline results from a longitudinal study investigating the effects of cognitive enhancement therapy (CET) on brain structure and function in schizophrenia. METHODS: The sample consisted of 46 early course schizophrenia patients and 20 healthy controls. Diffusion-weighted images were processed using a free-water imaging pipeline, that separately models diffusion of water in tissue (FAt) and the extracellular space (FW). Tract-Based Spatial Statistics was performed on the FAt and FW diffusion tensor maps and average measures from 24 bilateral regions of interest (ROIs) were extracted. We examined WM structural differences between patients and controls and further investigated WM relations to neurocognition, social cognition, and clinical measures specifically in schizophrenia. RESULTS: Patients showed significant FAt reductions in the body of the corpus callosum, posterior thalamic radiation (PTR), cingulate gyrus, anterior corona radiata, corpus callosum, and corona radiata and FW elevations in the posterior corona radiata (PCR), uncinate fasciculus (UNC), and PTR compared to controls. For patients, positive correlations between FAt and working memory were observed in the PCR and fornix & stria terminalis (FXST). Negative associations between FW and attention/vigilance were observed in the UNC. Positive correlations between FAt and theory of mind (ToM) were observed in average whole-brain and FXST. Negative associations between FW and ToM were observed in average whole-brain and PCR. Positive correlations between FW and negative symptom severity were observed in the external capsule. CONCLUSION: Using free-water imaging, we report WM aberrations and FW elevations in the early course of schizophrenia in addition to neural correlates associated with cognition and clinical measures. Future investigations on the longitudinal effects of CET are warranted for a greater understanding of the underlying neural correlates of clinical manifestations in schizophrenia. / 2020-06-14T00:00:00Z

In recent years, the treatment of phosphorus in Nyland's water treatment plant (located in Åre municipality) has been substandard. The problem has persisted despite attempts to lower the concentration to meet the emission requirements. A desire to find alternative, more environmentally friendly treatment methods has therefore been expressed from the municipality.Aside from the requirements, there is a desire to keep nutrient levels in the recipient (Indalsälven) low to preserve its natural state. A recognized method for treating wastewater is the use of constructed wetlands, where the characteristics of a natural wetland are enhanced and taken advantage of.The assessment of which type of constructed wetland that would be most beneficial to apply, was done by rating and weighting a number of characteristics of importance for lowering the phosphorus concentration. A first-order area-based model was used to estimate the size of the wetland.This report found that there is a suitable site to build a free water surface wetland in the vicinity of the water treatment plant. The wetland would act as a polishing step in the treatment train. As there is an element of uncertainty in treatment performance when a living ecosystem as wetlandis used, it is advised to enlarge this study and include more design aspects to refine the layout and configuration. / <p>2023-06-02</p>

A large pilot-scale free water surface (FWS) constructed wetland polishing effluent from an annual (spring) discharge municipal lagoon was operated for ten years followed by eleven years of dormancy and then restarted with an increase in operating depth. No significant effect of system aging was observed on Biological Oxygen Demand (BOD), total phosphorus (TP), and soluble reactive phosphorus (SRP) removal efficiencies, although internal TP water column concentrations in the first wetland and pond cells increased with time due to resuspension of accumulated sediments. Nitrate and ammonium removal efficiencies were higher during the start-up period due to plant establishment, while organic nitrogen and nitrate removal efficiencies increased during the restart period, likely due to a combination of the increased operating depth and accumulated sediments. No seasonal temperature effect was observed for nitrate or BOD removal efficiency, however, TP removal efficiencies increased with increasing influent concentrations due to seasonal algae growth. TSS removal efficiency increased significantly during the restart period, most likely due to an increase in the operating depth. Phosphorus was found to be mostly stored in the soil, followed by sediment and plants, while nitrogen was found to be stored more in plants, followed by soil and sediment. The wetland system was shown to be effective at the long-term removal of organic matter (BOD5 < 10 mg/L) and TP (87% average removal efficiency), while TSS removal efficiency increased to 97% with an increase in operating depth from 25 to 50 cm.

yes / A two-dimensional steady potential flow theory is applied to calculate the flow in an open channel with complex solid boundaries. The boundary integral equations for the problem under investigation are first derived in an auxiliary plane by taking the Cauchy integral principal values. To overcome the difficulties of a nonlinear curvilinear solid boundary character and free water surface not being known a priori, the boundary integral equations are transformed to the physical plane by substituting the integral variables. As such, the proposed approach has the following advantages: (1) the angle of the curvilinear solid boundary as well as the location of free water surface (initially assumed) is a known function of coordinates in physical plane; and (2) the meshes can be flexibly assigned on the solid and free water surface boundaries along which the integration is performed. This avoids the difficulty of the traditional potential flow theory, which seeks a function to conformally map the geometry in physical plane onto an auxiliary plane. Furthermore, rough bed friction-induced energy loss is estimated using the Darcy-Weisbach equation and is solved together with the boundary integral equations using the proposed iterative method. The method has no stringent requirement for initial free-water surface position, while traditional potential flow methods usually have strict requirement for the initial free-surface profiles to ensure that the numerical computation is stable and convergent. Several typical open-channel flows have been calculated with high accuracy and limited computational time, indicating that the proposed method has general suitability for open-channel flows with complex geometry.

Ce travail de thèse concerne la modélisation du béton et des ouvrages en béton soumis à des sollicitations allant du quasi statique à la dynamique rapide, tout en prenant en compte de la présence d'eau libre dans les pores du béton. L'objectif est la mise au point d'un outil prévisionnel de simulation capable de décrire le comportement du béton et des structures en béton, en tenant compte des effets du taux de saturation. Le choix des Éléments Discrets pour cette modélisation est justifié par les phénomènes discontinus qui apparaissent dans le béton, tel que la fissuration, la fragmentation ou l'écaillage. Les Éléments Discrets permettent de reproduire de manière fiable et efficace le comportement discontinu local ainsi que la réponse globale de la structure.La première partie de ce travail concerne la simulation d'essais quasi-statiques sous sollicitations uniaxiales et triaxiales fortement confinées, avec la prise en compte du phénomène de compaction. Les effets de l'eau libre contenue dans les porosités sont pris en compte par l'introduction d'une dépendance entre le taux de saturation en eau et la déformation inélastique. La procédure d’identification des paramètres du modèle est présentée. Enfin, le modèle est validé en reproduisant le comportement quasi-statique du béton par différents essais. La deuxième partie de ce travail est consacrée au comportement dynamique du béton. L'objectif est d'étendre la validation du modèle en simulant des essais d'impacts. Les effets de vitesse sont pris en comptes et des simulations d'impact sur des dalles en béton de différentes épaisseurs sont effectuées. Les résultats obtenus sont en bonne concordance avec les résultats expérimentaux. / This thesis concerns the modeling of concrete and concrete structures subjected to stresses ranging from quasi-static to dynamic loading, taking into account the presence of free water in pores. The objective is the development of a predictive simulation tool capable of describing the behavior of concrete and concrete structures, taking into account the effects of saturation ratio. The choice of discrete elements for modeling is justified by the discontinuous phenomena that appear in the concrete, such as cracking, fragmentation, spalling and scabbing. Discrete Elements can reproduce reliably and efficiently the local discontinuous behavior and the overall response of the structure.The first part of this work concerns the simulation of quasi-static tests under uniaxial and highly confined triaxial loadings, taking into account the compaction phenomenon. The effects of the free water contained in the pores are taken into account by introducing a dependency between the water saturation level and the inelastic deformation. The identification process of the model parameters is presented. Finally, the model is validated by reproducing the quasi-static behavior of concrete in different tests.The second part of this work concerns the dynamic behavior of concrete. The aim is to extend the validation of the model by simulating impact tests on concrete slabs of different thickness. The dynamic effects are taken into account and impact simulations on concrete slabs of different thickness are made. The results are in good agreement with experimental results.

Diffusion of water molecules in biological tissues depends on several microstructural properties. Therefore, diffusion Magnetic Resonance Imaging (dMRI) is a useful tool to infer and study microstructural brain changes in the context of human development, ageing and neuropathology. In this thesis, the state-of-the-art of advanced dMRI techniques is explored and strategies to overcome or reduce its pitfalls are developed and validated. Firstly, it is shown that PCA denoising and Gibbs artefact suppression algorithms provide an optimal compromise between increased precision of diffusion measures and the loss of tissue's diffusion non-Gaussian information. Secondly, the spatial information provided by the diffusion kurtosis imaging (DKI) technique is explored and used to resolve crossing fibres and generalize diffusion measures to cases not limited to well-aligned white matter fibres. Thirdly, as an alternative to diffusion microstructural modelling techniques such as the neurite orientation dispersion and density imaging (NODDI), it is shown that spherical deconvolution techniques can be used to characterize fibre crossing and dispersion simultaneously. Fourthly, free water volume fraction estimates provided by the free water diffusion tensor imaging (fwDTI) are shown to be useful to detect and remove voxels corrupted by cerebrospinal fluid (CSF) partial volume effects. Finally, dMRI techniques are applied to the diffusion data from the large collaborative Cambridge Centre for Ageing and Neuroscience (CamCAN) study. From these data, the inference provided by diffusion anisotropy measures on maturation and degeneration processes is shown to be biased by age-related changes of fibre organization. Inconsistencies of previous NODDI ageing studies are also revealed to be associated with the different age ranges covered. The CamCAN data is also processed using a novel non-Gaussian diffusion characterization technique which is invariant to different fibre configurations. Results show that this technique can provide indices specific to axonal water fraction which can be linked to age-related fibre density changes.

Fluid migration behind the cased holes is an important problem for oil and gas industry both considering short terms and long terms after cementing operation. For many reasons like high formation pressures, high shrinkage rate of cement slurry while setting, lack of mechanical seal, channeling due to cement slurry setting profile, hydrocarbon migration may occur and lead expensive recompletion operations and sometimes abandonment. Solutions to this problem vary including high density-low fluid loss cement slurry or right angle cement setting profile. During this study, the effect of &ldquo / free water&rdquo / which is the basic quality property of API G class cement, on fluid migration potential has been tested for different samples and in combination with different physical conditions. For this study API G class cements have been used. In order to justify the quality of each cement sample standard API G class quality tests were conducted. Moreover, as a main instrument &ldquo / Static Gel Strength Analyzer&rdquo / is used to measure the static gel strength of cement slurry and how long it takes to complete transition time. Bolu cement, Nuh cement, and Mix G cement samples were tested according to their free fluid values which are %2.5, %5, %3.12 respectively, and it is found that the Bolu cement with lowest free fluid content has the lowest potential for fluid migration. As a conclusion, fluid migration through behind the cased hole is a major threat for the life of the well. Appropriate cement slurry system may easily defeat this threat and lead cost saving well plans. Key words: Fluid migration, fluid loss, transition time, channeling, right angle, API G class cement, free water, high formation pressure

Η μελέτη ενός πειράματος μικρής πιλοτικής κλίμακας, με δύο παράλληλα συστήματα ρηχών λεκανών (ύψους 0.35m), η μία λεκάνη με φύτευση του είδους Typha Latifolia και η άλλη χωρίς φύτευση, διεξάχθηκε για τον σχεδιασμό ελεύθερης επιφανειακής ροής (FWS) τεχνητού υγροτόπου. Οι δύο λεκάνες τροφοδοτήθηκαν με πραγματικά αστικά λύματα όπου οι χρόνοι παραμονής κυμάνθηκαν από 27,6 έως 38,0 ημέρες. Η μεταβολή του όγκου κάθε λεκάνης παρακολουθήθηκε για 2 συνεχή έτη και ταυτόχρονα υπολογίστηκαν οι ρυθμοί βροχόπτωσης και εξάτμισης. Η διαφορά του όγκου μεταξύ των δύο λεκανών οφειλόταν στην πρόσληψη νερού από τα φυτά, η οποία συγκρίθηκε με τις προβλέψεις της εξατμισοδιαπνοής παρόμοιων φυτών με την χρήση του υπολογιστικού προγράμματος REF-ET. Η συγκομιδή των φυτών πραγματοποιήθηκε τρείς φορές στην διάρκεια του 1ου έτους του πειράματος, ώστε να εκτιμηθεί ο ρυθμός πρόσληψης αζώτου από τα φυτά. Η σημαντικότερη διαφορά των δύο συστημάτων ήταν η αφαίρεση νερού μέσω της εξατμισοδιαπνοής των φυτών. Η πιλοτική μονάδα λειτούργησε έτσι ώστε να επιτευχθεί και απομάκρυνση της οργανικής ύλης (BOD5) και του ολικού αζώτου (TN) από τα λύματα. Ο σχεδιασμός της διευκόλυνε την ανάπτυξη ενός μαθηματικού μοντέλου, ακολουθώντας το πλαίσιο του μοντέλου της ενεργής ιλύος (ASM). Αρχικά το μαθηματικό μοντέλο αναπτύχθηκε για τις δύο λεκάνες με τις μικροβιακές διεργασίες που επικράτησαν στο εσωτερικό τους, ώστε να περιγραφεί πλήρως η συμπεριφορά τους. Η προσομοίωση και η εκτίμηση των παραμέτρων του μοντέλου επιτεύχθηκε με την χρήση του υπολογιστικού περιβάλλοντος του AQUASIM. Οι κύριες διεργασίες που ελήφθησαν υπόψη για την μοντελοποίηση ήταν η αμμωνιοποίηση, η αερόβια ετεροτροφική ανάπτυξη, η νιτροποίηση και η ανάπτυξη φυκών. Μια ισχυρή εποχική εξάρτηση παρατηρήθηκε για την συμπεριφορά κάθε λεκάνης όταν το μοντέλο εφαρμόστηκε για το 1ο έτος του πειράματος. Αυτό το μοντέλο επαληθεύτηκε ικανοποιητικά με τα πειραματικά δεδομένα του 2ου έτους. Η παρατηρούμενη μέση ετήσια απόδοση απομάκρυνσης του BOD5 και του TN ήταν 60% και 69%, αντίστοιχα για την λεκάνη χωρίς φυτά και 83% και 75%, αντίστοιχα για την λεκάνη με φυτά. Το μοντέλο προέβλεψε μέση ετήσια απόδοση απομάκρυνσης 82% για το BOD5 και 65% για το TN στην λεκάνη με φυτά, ικανοποιώντας τα κριτήρια για τον σχεδιασμό πλήρους κλίμακας τεχνητού υγροτόπου . Η ικανότητα του μοντέλου να προβλέπει όχι μόνο την απομάκρυνση της οργανικής ύλης αλλά και του ολικού αζώτου, θεωρήθηκε επαρκής όταν δοκιμάστηκε με έναν ελεύθερης επιφανειακής ροής τεχνητό υγρότοπο με 400 ισοδύναμο πληθυσμό, με μοναδική τροποποίηση τον συνυπολογισμό του περιορισμού του οξυγόνου στον ρυθμό της διεργασίας της νιτροποίησης. Επομένως, το δυναμικό μοντέλο διαμορφώθηκε με την ενσωμάτωση της πρόβλεψης του ρυθμού της εξατμισοδιαπνοής των φυτών και χρησιμοποιήθηκε για τον σχεδιασμό περίπτωσης μελέτης τεχνητού υγροτόπου πλήρους κλίμακας. Τα στοιχεία που απαιτούνται για αυτό τον σχεδιασμό περιλάμβαναν την παροχή εισόδου και κλιματολογικά στοιχεία (θερμοκρασίας και βροχόπτωσης) για την περιοχή του σχεδιασμού, καθώς και οι απαιτήσεις της ποιότητας εκροής. Η περίπτωση μελέτης για 4000 ισοδύναμο πληθυσμό όπου η ποιότητα εκροής ήταν σε μέσες ετήσιες τιμές BOD5=25mg/L και TN=15mg/L, χρειάστηκε μία συνολική επιφάνεια υγροτόπου 11 εκταρίων. Εάν χρησιμοποιηθούν δύο λεκάνες σε σειρά, η 1η με φυτά και η 2η χωρίς, τότε η συνολική επιφάνεια μειώνεται κατά περίπου 27%, ελέγχοντας μόνο την αρχική μέγιστη φύτευση της πρώτης λεκάνης του υγροτόπου. / The study at pilot-scale of two parallel systems with shallow basins (height h=0.35m), one planted with Typha Latiofolia and the other without vegetation, was conducted for the modeling of free water surface (FWS) constructed wetland systems. The basins were fed with real sewage at retention times ranging from 27.6 to 38.0 days. The variation of the volume in each basin was monitored for two consecutive years and simultaneously, rainfall and evaporation rates were calculated. The difference of the volume between the basins was due to the water absorption by the plants and was compared with the predictions of evapotranspiration rates of similar plants using the REF-ET calculation software. The harvesting of the plants was performed three times during the first year, in order to estimate the nitrogen uptake by the plants. The main difference in the two systems was the water removal through plant evapotranspiration. The pilot unit was operated so as to achieve the removal of both organic matter (BOD5) and total nitrogen (TN) from the sewage. Its design enabled the development of a mathematical model, following the framework of the activated sludge model (ASM). The simulation and the parameter estimation were achieved using the AQUASIM framework. The mathematical model describes the microbial processes, which dominated within the basins describing satisfactorily their behavior. The key processes accounted for in the modeling were ammonification, aerobic heterotrophic growth, nitrification and algal growth. A strong seasonal dependence was observed for each basin. The model was satisfactorily validated with the data of the second year. An observed average annual removal efficiency of BOD5 and TN were 60% and 69%, respectively for the basin without plants and 83% and 75%, respectively for the basin with plants. The model predicted average annual removal efficiency 82% for BOD5 and 65% for TN in the basin with plants, satisfying the design criteria of a full-scale constructed wetland. The ability of the model to predict not only the removal of organic matter but also total nitrogen removal, was considered sufficient as tested with a real free water surface constructed wetland of 400 population equivalent, with the sole modification being the inclusion of oxygen limitation in the nitrification rate. The dynamic model was amended with the direct incorporation of the plant evapotranspiration rate and it was used to design a full-scale constructed wetland. The required elements for this design included the inflow rate and climatic data (temperature and rainfall) for the design region, as well as the effluent quality requirements. In the case study of 4000 population equivalent, the effluent quality requirement was: average annual values for BOD5=25mg/L and for TN=15mg/L. The model was used to determine a total wetland surface requirement of 11ha. If two sequential basins are used, the first with plants and the second without, then the total wetland surface could be reduced by approximately 27%, controlling only the maximum initial vegetation in the first wetland basin.