129 research outputs found

    Green Preparation of Aluminum-based Metal-organic Framework (Al-MOF) from Waste Plastic Bottles and Waste Aluminum Scraps

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    The vast use of polyethylene terephthalate (PET) drinking water bottles has increased dramatically worldwide in recent decades, inflicting severe consequences on the environment. According to the latest survey, a million plastic bottles are bought around the globe every minute. The non-biodegradable nature of PET materials has led to a huge accumulation of plastic in waste landfills. Among the current recycling methods used to solve this environmental problem is chemical recycling. In this method, PET bottles are converted back cleanly into their starting materials: terephthalic acid and ethylene glycol. This paper unveils the exploitation of recycling products from PET bottles and aluminium scraps in order to prepare a metal-organic framework (MOF) material. The characterization of the prepared MOF substance was carried out using different techniques such as IR, XRD, SEM and elemental analysis.                 &nbsp

    Incorporation of fault rock properties into production simulation models

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    This thesis has two aims. First, to investigate the importance of incorporating the multiphase flow properties of faults into production simulation models. Second, to investigate methodologies to incorporate the multiphase flow properties of faults into production simulation models. Tests using simple simulation models suggest that in some situations it is not particularly important to take into account the multiphase flow properties of faults, whereas in other situations the multiphase properties have proved very important. The differences depend on drive mechanism, well position, and the capillary pressure distribution along the fault as well on the parameters that need to be modelled (e. g. bottom-hole pressures, hydrocarbon production rates, water cuts, etc. ). The results show that it is possible for hydrocarbons to flow across a sealing fault (i. e. 100% water saturation) as a result of its threshold pressure being overcome. The relative permeability of fault rocks may be one of the largest unknowns in simulating fluid in structurally complex petroleum reservoirs. Microstructural and petrophysical measurements are conducted on faults from core within the Pierce Field, North Sea. The results are used to calculate transmissibility multipliers (TMs) required to take into account the effect of faults on fluid flow within the Pierce production simulation model. The fault multiphase flow behaviour is approximated by varying the TMs as a function of height above the free water level. This methodology results in an improved history match of production data. Further, the improved model is then used to plan the optimal time to conduct a follow-up 3D seismic survey to identify unswept compartments. Further, an alternative model was proposed to overcome some of the possible limitations that the previous TM treatments may have at certain stages of a reservoir life. The similar behaviour of the different proposed fault models for the Pierce Field indicate that the current faulting system in this model is not largely responsible for the history mismatch in water production. Multiphase flow properties of faults can be incorporated into production simulation models using dynamic pseudofunctions. In this thesis, different dynamic pseudofunctions are generated by conducting high-resolution fluid flow models at the scale of the reservoir simulation grid block, using flow rates similar to those that are likely to be encountered within petroleum reservoirs. In these high-resolution models, both the fault and reservoir rock are given their own capillary pressure and relative permeability curves. The results of the simulations are used to create pseudocurves that are then incorporated into the up-scaled production simulation model to account for the presence of both the fault and undeformed reservoir. Different flow regimes are used to compare the performance of each pseudoisation method with the conventional, single-phase TM fault representations. The results presented in this thesis show that it is more important to incorporate fault multiphase properties in capillary dominated flow regimes than in those that are viscosity dominated. It should, however, be emphasised that the Brooks-Corey relations used to estimate relative permeability and capillary pressure curves of the fault rock in this study have a significant influence on some of these conclusions. In other words, these conclusions may not be valid if the relative permeability curves of fault rocks are very different to those calculated using the aforementioned relationships. Finally, an integrated workflow is outlined showing how dynamic pseudofunctions can be generated in fault juxtaposition models by taking advantage of the dynamic flux preservation feature in Eclipse 10OTM simulator

    Analyzing stance in parliamentary debates: a corpus-assisted study using the APPRAISAL Framework

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    The current study investigates the language of stance, stance-taking and intersubjective stance in parliamentary discourse by analysing the Appraisal resources used by MPs in the UK Parliament. Focusing in particular on the attitudinal and dialogistic (ENGAGEMENT) resources used by parliamentarians in debates on the subject of flooding, the Thesis explores the role that these resources play in the construction of stance and intersubjective stance in parliamentary debates. Using Appraisal Framework of Martin and White (2005) and conducting a corpus-assisted discourse study (CADS), this study shows that the relationship between language and political stance is complex and not always straightforward due to the nature of political discourse as it unfolds in the highly specific context of parliamentary debating, which is a subgenre of political discourse that has its own rules and conventions. Further, it is argued that political stance cannot always be read directly from surface language forms in parliamentary debates. Politicians might express a public stance that is different from, if not diametrically opposed to, their real stance. They do so to achieve certain diplomatic and political ends particularly if exposing their real stance would harm their relations with their own political party affiliations. While this Thesis demonstrates that the Appraisal Framework can be a practicable framework for analysing stance in parliamentary debates, it also reveals some features of stance-taking in parliamentary instances that the Appraisal Framework fails to detect. The Thesis proposes to rectify this by introducing two new sub-categories – ACCLAIM and DENOUNCE - within the ENGAGEMENT system. Another innovative contribution of this study relates to the ATTRIBUTION sub-system of the Appraisal Framework. The current distinction between ATTRIBUTION subcategories is mainly based on its dialogistic role in text (contractiveness and expansiveness). This Thesis proposes to consider the criterion of relevance between authorial stance and attributed stance in analysing ATTRIBUTION cases. If this relevance is positive, then ATTRIBUTION is supportive, whereas if the relevance between the authorial stance and the attributed stance is negative, then ATTRIBUTION is confrontational. Applying this distinction to parliamentary debates, the Thesis finds that confrontational types of ATTRIBUTION are mostly detected in ATTRIBUTE + COUNTER sequences. Therefore, another proposal of this Thesis is to view ENGAGEMENT values as sequences, rather than self-standing units. Applying this view to the empirical data collected for this Thesis, it is established that ENGAGEMENT values do not operate separately in parliamentary debates, and consequently there is a need to analyse them as sequences to better understand their meanings and dialogistic effects in text. The analysis is also extended to include a comparative analysis between Government MPs and Opposition MPs in their use of attitudinal language and ENGAGEMENT resources. The results suggest that there is a strong correlation between the parliamentary role of MPs and the type of attitudinal and ENGAGEMENT sequences they use. It is argued that the recurrence of argumentative polarized stance among MPs is problematic in that it has the potential to damage the authenticity of parliaments as deliberative institutions. Thus, this Thesis identifies reform of the linguistic conventions of parliamentary debating as a crucial part of any attempt to reform parliamentary institutions more generally

    Attitudes of Pre-school Teachers towards Movement Education

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    Educators’ attitudes have drawn attention of researchers worldwide, where numerous studies have been conducted to explore the factors that influence educators’ attitudes toward educational topics in order to understand them and direct them in ways that contribute to the enhancement of the educational practices. In this study, we aimed to identify attitudes of early childhood educators in the Sultanate of Oman towards movement education, and to investigate the differences in attitudes according to nationality and qualification. The sample of this study consisted of 201 pre-school female educators in the Sultanate of Oman. The participants responded to Attitudes towards Movement Education Scale, which consisted of three dimensions (emotional, cognitive and behavioral). This scale was designed and modified for the purpose of this study. The results of this study revealed that the participants’ attitudes towards movement education were positive in general. The emotional dimension ranked first (87.7%), followed by the cognitive (82.6%) and behavioral dimensions (78.8%). The results also showed that there were differences in attitudes towards movement education due to educators’ nationality and educational levels

    Massive Upper Gastrointestinal Bleeding Secondary to Duodenal Metastasis of Transitional Cell Carcinoma of the Urinary Bladder

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    Acute upper gastrointestinal (UGI) bleeding is a common problem in our clinical practice and is often due to peptic ulcer diseases. Occasionally, malignancy may be implicated in these situations. Here we report a rare case of UGI bleeding secondary to metastatic transitional cell carcinoma (TCC) of the urinary bladder. A 62-year-old man with a history of stage IIIb TCC of the urinary bladder presented with hematemesis. Endoscopy showed a large tumor in the second stage of the duodenum that occupied 40% of the duodenal circumference, over 7 cm in length. Biopsies revealed a poorly differentiated malignant neoplasm consistent with metastasis from urothelial carcinoma that was identical to the previous surgical specimen of the urinary bladder. He was treated with supportive therapy and intravenous proton pump inhibitor and was discharged home 2 weeks later. Two weeks after discharge, the patient returned to the hospital with a painful swelling of the floor of his mouth. Biopsy again showed the same cancer type. He had unremitting bleeding from his mouth requiring multiple transfusions and a course of palliative radiation therapy. He progressively deteriorated in his cardiopulmonary and neurological functions and expired with cardiopulmonary arrest one month later

    Nutritional Practices of Athletes in Oman: A Descriptive Study

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    Objective: Adequate dietary intake is crucial for optimum training and performance of athletes. There is almost no available information related to dietary practices among Omani athletes, especially during the competition. This study aimed to assess the nutritional practices (nutritional knowledge, eating habits and daily nutrients intake) among Omani male handball athletes in Muscat city, Oman.Methods: This is a cross sectional study including 35 male handball athletes involved in serious training for no less than three years. Data collection was done through personal interviews using a study questionnaire which enlisted questions relating to socio-demographic information, anthropometric measurements and nutritional practices. All the study participants declared no intake of anabolic steroids.Results: The mean age of the study participants was 27 ± 3 years. Their anthropometric assessment revealed that their mean height was 166 ± 12 cm, mean weight was 75 ± 10 kg, and body mass index was 27 ± 3. Nutritional knowledge analysis revealed that 80% had no nutritional supervision by a nutritionist/dietitian. Their knowledge of nutritional requirements was only 23% correct for total energy intake, 63% for protein intake, 46% for carbohydrate intake, 11% for fat intake and 83% for water intake. Eating habits indicated that 55% had <3 meals/day, 51% had lunch as the principal meal, 51% always added extra salt to their food, 28% took protein supplements on a daily basis, and 51% used pre-competition glycogen load diet. However, none consumed vitamins or mineral supplements. The mean daily caloric intake was 3674 ± 265 kcal/day, which was roughly comprised of 596 ± 66 g carbohydrates, 147 ± 28 g of protein and 78 ± 20 g of total fat.Conclusion: Professional nutritional supervision is needed in order to improve the nutritional knowledge and eating habits of Omani athletes, and therefore improve their athletic performance

    Hepatocellular Carcinoma in Oman: An analysis of 284 cases

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    Objectives: Hepatocellular carcinoma (HCC) is the most common type of primary liver tumour worldwide and is increasing in incidence. This study aimed to describe the clinical characteristics of HCC among Omani patients, along with its major risk factors, outcomes and the role of surveillance. Methods: This retrospective case-series study was conducted between January 2008 and December 2015 at the three main tertiary care hospitals in Oman. All adult Omani patients diagnosed with HCC and visited these hospitals during the study period were included. Relevant data were collected from the patients’ electronic medical records. Results: A total of 284 HCC patients were included in the analysis. The mean age was 61.02 ± 11.41 years and 67.6% were male. The majority had liver cirrhosis (79.9%), with the most common aetiologies being chronic hepatitis C (46.5%) and B (43.2%). Only 13.7% of cases were detected by the HCC surveillance programme. Approximately half of the patients (48.5%) had a single liver lesion and 31.9% had a liver tumour of &gt;5 cm in size. Approximately half (49.2%) had alpha-fetoprotein levels of ≥200 ng/mL. The majority (72.5%) were diagnosed using multiphase computed tomography alone. Less than half of the patients (48.9%) were offered one or more HCC treatment modalities. Conclusion: The majority of Omani HCC patients were male and had cirrhosis due to viral hepatitis. In addition, few patients were identified by the national surveillance programme and presented with advanced disease precluding therapeutic or even palliative treatment.Keywords: Hepatocellular Carcinoma; Liver Cirrhosis; Human Viral Hepatitis; Public Health Surveillance; Early Detection of Cancer; Alpha-Fetoprotein; Oman

    Prediction of portal pressure from intraoperative ultrasonography

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    BackgroundPortal hypertension is a major risk factor for hepatic failure or bleeding in patients who have undergone hepatectomy, but it cannot be measured indirectly. We attempted to evaluate the intraoperative ultrasonography parameters that correlate with portal pressure (PP) in patients undergoing hepatectomy.MethodsWe examined 30 patients in whom PP was directly measured during surgery. The background liver conditions included chronic viral liver disease in seven patients, chemotherapy-associated steatohepatitis in four patients, fatty liver in one patient, hepatolithiasis in one patient, obstructive jaundice in one patient, and a normal liver in 16 patients. A multivariate logistic analysis and linear regression analysis were conducted to develop a predictive formula for PP.ResultsThe mean PP was 10.4 ± 4.1 mm Hg. The PP tended to be increased in patients with chronic viral hepatitis. A univariate analysis identified the association of the six following parameters with PP: the platelet count and the maximum (max), minimum (min), endo-diastolic, peak-systolic, and mean velocity in the portal vein (PV) flow. Using multiple linear regression analysis, the predictive formula using the PV max and min was as follows: Y (estimated PP) = 18.235?0.120 × (PV max.[m/s])?0.364 × (PV min). The calculated PP (10.44 ± 2.61 mm Hg) was nearly the same as the actual PP (10.43 ± 4.07 mm Hg). However, there was no significant relationship between the calculated PP and the intraoperative blood loss and post hepatectomy morbidity.ConclusionsThis formula, which uses ultrasonographic Doppler flow parameters, appears to be useful for predicting PP

    Global prevalence and genotype distribution of hepatitis C virus infection in 2015 : A modelling study

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    Publisher Copyright: © 2017 Elsevier LtdBackground The 69th World Health Assembly approved the Global Health Sector Strategy to eliminate hepatitis C virus (HCV) infection by 2030, which can become a reality with the recent launch of direct acting antiviral therapies. Reliable disease burden estimates are required for national strategies. This analysis estimates the global prevalence of viraemic HCV at the end of 2015, an update of—and expansion on—the 2014 analysis, which reported 80 million (95% CI 64–103) viraemic infections in 2013. Methods We developed country-level disease burden models following a systematic review of HCV prevalence (number of studies, n=6754) and genotype (n=11 342) studies published after 2013. A Delphi process was used to gain country expert consensus and validate inputs. Published estimates alone were used for countries where expert panel meetings could not be scheduled. Global prevalence was estimated using regional averages for countries without data. Findings Models were built for 100 countries, 59 of which were approved by country experts, with the remaining 41 estimated using published data alone. The remaining countries had insufficient data to create a model. The global prevalence of viraemic HCV is estimated to be 1·0% (95% uncertainty interval 0·8–1·1) in 2015, corresponding to 71·1 million (62·5–79·4) viraemic infections. Genotypes 1 and 3 were the most common cause of infections (44% and 25%, respectively). Interpretation The global estimate of viraemic infections is lower than previous estimates, largely due to more recent (lower) prevalence estimates in Africa. Additionally, increased mortality due to liver-related causes and an ageing population may have contributed to a reduction in infections. Funding John C Martin Foundation.publishersversionPeer reviewe
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