135 research outputs found

    Viscosity effects on sand flow regimes and transport velocity in horizontal pipelines

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    Solids transport in multiphase systems is one of the issues under the umbrella of ‘‘flow assurance.’ But unlike issues such as waxes and hydrates, solids transport has received relatively little interest to date. The overall aim of this research was to investigate the fluid viscosity effects on sand particle transport characteristics in pipelines. Investigations were conducted using a 3-inch test facility for oil and a 4- inch flow loop for water and CMC experiments. Three oil viscosities were used including 105 cP, 200 cP and 340 cP. The sand used had a density of 2650 kg/m3 and a median diameter of 0.2 mm. The sand loadings were 50 lb/1000 bbl and 200lb/1000bbl. Based on the King et al (2000) sand minimum transport condition definition, the sand transport velocity for water, CMC solutions and oil (105 cP, 200 cP and 340 cP) were determined by visual observation and camera. The observed sand/oil flow regimes were compared. For oil/sand tests, it was observed that the dominant regime when approaching the critical sand transport velocity was the sliding sand bed, sand dunes were notably absent. However, for water and 7 cP CMC solution, sand dunes and sliding sand bed regimes were observed when approaching the sand transport velocity. For 20cP CMC solution, it was observed that the sand particles in the region between the main dunes were very active compared to those within the dunes

    Pyrolysis of azetidinone derivatives: a versatile route towards electron-rich alkenes, C-1 allylation and/or homologation of aldehydes

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    Pyrolysis of beta-lactams and beta-thiolactams led essentially to stereoselective synthesis of the high energy electron-rich Z-alkenes. Extension of this methodology to the pyrolysis of 3-allyloxy derivatives gave a simple direct route to the synthetically important 4-pentenal. These pyrolytic transformations convert aldehydes to aryloxyalkenes (a protected homologation) and 4-pentenal (a C-1 allylation and homologation). The starting 3-aryloxy and 3-allyloxy-beta-lactams were synthesized by the standard Staudinger ketene-imine [2 + 2] cycloaddition. The corresponding beta-thiolactams have readily been obtained in good yields by thiation of beta-lactams with Lawesson's reagent.University of Kuwait/SC 02/11GF-S/GS01/01, GS02/01, GS01/03, GS01/0

    Identification of novel differentially expressed genes in type 1 diabetes mellitus complications using transcriptomic profiling of UAE patients: a multicenter study

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    Type 1 diabetes mellitus (T1DM) is a chronic metabolic disorder that mainly affects children and young adults. It is associated with debilitating and long-life complications. Therefore, understanding the factors that lead to the onset and development of these complications is crucial. To our knowledge this is the first study that attempts to identify the common differentially expressed genes (DEGs) in T1DM complications using whole transcriptomic profiling in United Arab Emirates (UAE) patients. The present multicenter study was conducted in different hospitals in UAE including University Hospital Sharjah, Dubai Hospital and Rashid Hospital. A total of fifty-eight Emirati participants aged above 18 years and with a BMI < 25 kg/m2 were recruited and forty-five of these participants had a confirmed diagnosis of T1DM. Five groups of complications associated with the latter were identified including hyperlipidemia, neuropathy, ketoacidosis, hypothyroidism and polycystic ovary syndrome (PCOS). A comprehensive whole transcriptomic analysis using NGS was conducted. The outcomes of the study revealed the common DEGs between T1DM without complications and T1DM with different complications. The results revealed seven common candidate DEGs, SPINK9, TRDN, PVRL4, MYO3A, PDLIM1, KIAA1614 and GRP were upregulated in T1DM complications with significant increase in expression of SPINK9 (Fold change: 5.28, 3.79, 5.20, 3.79, 5.20) and MYO3A (Fold change: 4.14, 6.11, 2.60, 4.33, 4.49) in hyperlipidemia, neuropathy, ketoacidosis, hypothyroidism and PCOS, respectively. In addition, functional pathways of ion transport, mineral absorption and cytosolic calcium concentration were involved in regulation of candidate upregulated genes related to neuropathy, ketoacidosis and PCOS, respectively. The findings of this study represent a novel reference warranting further studies to shed light on the causative genetic factors that are involved in the onset and development of T1DM complications

    Cancer Survival by Stage at Diagnosis in Kuwait: A Population-Based Study.

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    OBJECTIVE: To examine the distribution of stage at diagnosis for 12 cancers in Kuwait, to estimate stage-specific net survival at 1 and 5?years after diagnosis, and to assess differences in stage-specific survival between Kuwait and the United States. MATERIAL AND METHODS: Data were obtained from the Kuwait Cancer Registry, for Kuwaiti patients diagnosed during 2000-2013, with follow-up to 31 December 2015. The distribution of Surveillance Epidemiology and End Results (SEER) Summary Stage for 12 malignancies was examined. We estimated net survival by stage up to 5?years after diagnosis, controlling for background mortality with life tables of all-cause mortality in the general population by single year of age, sex, and calendar period. Survival estimates were age-standardised using the International Cancer Survival Standard (ICSS) weights. RESULTS: Only 14.2% of patients were diagnosed at a localised stage and 38.9% at the regional stage. The proportion of patients with known stage was 88.9% during 2000-2004 but fell to 59.4% during 2010-2013. During 2005-2009, 1- and 5-year survival for colon, rectal, breast, cervical, and prostate cancer was about 90% or higher for patients diagnosed at the localised stage. During 2004-2009, the proportion of patients diagnosed at a localised stage was lower in Kuwait than in the US for colon, breast, and lung cancer. Age-standardised 5-year net survival for all stages combined was lower in Kuwait than the US for colon, lung, and breast cancer, but stage-specific survival was similar. CONCLUSION: Since stage-specific survival is similar in Kuwait and the US, late stage at diagnosis is likely to be a major contributing factor to the overall lower survival in Kuwait than in the US. Increasing public awareness of cancer risk factors and symptoms and investment in early detection will be vital to reduce the proportion of patients diagnosed at a late stage and to improve survival

    Consanguinity and reproductive health among Arabs

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    Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity

    Stratigraphy of the Dammam Formation in Umm-Gudair area, Kuwait

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    The Dammam Formation in Umm-Gudair area in Kuwait was stu¬ died using cores and electrical logs from water wells. The Dammam Formation is a limestone-dolomite sequence of Middle Eocene age. It is underlain by Early Eocene Rus evaporites and is overlain uncon-formably by the clastic sediments of the Kuwait Group. It is subdivided into three members in Umm-Gudair area. The lower member, A, is a nummulitic limestone with shale interlayers at its base. The middle member, B, is a highly silicified and dolomitized fossiliferous limestone which includes lignite and silty lignite interlayers. The upper member, C, is a friable, white dolomite which is silicified and karstified at the top, beneath the unconformity with the overlying Kuwait Group. Similar silicification and karstifikation occurs at the top of the B member, and that suggest a minor but significant unconformity between the B and C members. The Dammam Formation was deposited on a shallow marine shelf experiencing minor fluctuations from lagoon to tidal flat and swamp environments. This tectonically stable period was interrupted by small pulses in the source land and minor fluctuations in the sea level, which caused alternating transgressive and regressive cycles.Stratigraphie de la Formation Dammam dans la region de Umm-Gudair, Koweit. Au Koweit, dans la région de Umm-Gudair la Formation Dammam a été étudiée à partir de carottes et de Logs électriques. Il s'agit d'un ensemble calcaire et dolomitique dâté de l'Eocène moyen. La Formation est encadrée, à sa base par les évapo-rites de l'Eocène inférieur et du sommet par les sédiments clastiques, discordants du Kuwait Group. Dans la région de Umm-Gudair la Formation est subdivisée en 3 membres. Le membre inférieur (A) est un calcaire à Nummulites avec des inter-lits argileux à sa base. Le membre moyen (B) est un calcaire fossilifère fortement silicifié et dolomitisé admettant du lignite et des inter-lits silteux et ligniteux. Le membre supérieur (C) est une dolomite blanche et friable, silicifiée et karstifiée au sommet, sous la discordance du Kuwait Group sus-jacent. Des siliciflcations et karstifications analogues apparaissent au sommet du membre B, ce qui suggère une petite mais significative inconformité entre les membres B et C. La Formation Dammam s'est déposée sur une plate-forme marine peu profonde, soumise à de petites fluctuations depuis des milieux de lagon jusqu'à des dépôts de "tidal-flat" et des environnements de marais. Cette période, tectoniquement stable, a été interrompue par de petits pulsations continentales et des fluctuations mineures du niveau de la mer, qui ont déterminé des cycles alternativement transgressifs et régressifs.Al-Awadi E., Al-Ruwaih F., Ozkaya S.I. Stratigraphy of the Dammam Formation in Umm-Gudair area, Kuwait. In: Géologie Méditerranéenne. Tome 25, numéro 2, 1998. pp. 105-116
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