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Recently, full-scale research about a passenger tube train system is being progressed as a next-generation transportation system in Korea in light of global green technology. The Korea Railroad Research Institute (KRRI) has commen...
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Recently, full-scale research about a passenger tube train system is being progressed as a next-generation transportation system in Korea in light of global green technology. The Korea Railroad Research Institute (KRRI) has commenced official research on the construction of a tube train system. In this paper, we studied various parameters of the tube train system such as the internal tube pressure, blockage ratio, and operating speed through computational analysis with a symmetric and elongated vehicle. This study was about the aerodynamic characteristics of a tube train that operated under standard atmospheric pressure (open field system, viz., ground) and in various internal tube environments (varying internal tube pressure, blockage ratio, and operating speed) with the same shape and operating speed. Under these conditions, the internal tube pressure was calculated when the energy efficiency had the same value as that of the open field train depending on various combinations of the operating speed and blockage ratio (the P- D relation). In addition, the dependence of the relation between the internal tube pressure and the blockage ratio (the P-Β relation) was shown. Besides, the dependence of the relation between the total drag and the operating speed depending on various combinations of the blockage ratio and internal tube pressure (the D-V relation) was shown. Also, we compared the total (aerodynamic) drag of a train in the open field with the total drag of a train inside a tube. Then, we calculated the limit speed of the tube train, i.e., the maximum speed, for various internal tube pressures (the V-P relation) and the critical speed that leads to shock waves under various blockage ratios, which is related to the efficiency of the tube train (the critical V-Β relation). Those results provide guidelines for the initial design and construction of a tube train system.
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Geosynthetic tubes inflated with water, clay slurry or sand have been widely used for large dike construction in land reclamation projects. In this paper, analytical solutions for geosynthetic tube resting on rigid foundation is p...
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Geosynthetic tubes inflated with water, clay slurry or sand have been widely used for large dike construction in land reclamation projects. In this paper, analytical solutions for geosynthetic tube resting on rigid foundation is presented by adopting an approach similar to that presented by Leshchinsky et al. (1996). The proposed method allows a quick preliminary design to be made for using a closed-form solution. To simplify the analysis, relationships between geometrical parameters and pumping pressure are established using numerical method. The analytical solutions were compared with several existing solutions and good agreements were achieved.
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Tubular products have very important applications in various areas especially in the transportation industries. For instance, in the structure of cars there are various tubular products like roof headers, engine cradles, roof rail...
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Tubular products have very important applications in various areas especially in the transportation industries. For instance, in the structure of cars there are various tubular products like roof headers, engine cradles, roof rails and frame rails with complex geometries which most of them need multiple steps like tube drawing, tube bending and hydroforming for their production. Based on the recent studies by this group, it was proven that in most of the structural tubular parts in the cars it was not necessary to have constant thickness along the axial direction of tube and it will be considered as overdesign and the overall weight of structures can be reduced considerably by using variable thickness tubes. In this paper, the variable thickness tube drawing and its applications in the tube bending and hydroforming applications were studied. The results showed that this process can have important role in reduction of defective parts in the production of complex tubes by the tube hydroforming method. However especial considerations should be taken into account in the design of thickness distribution along axial direction of these kinds of tubes to avoid problems in the drawing step and as well in the bending and hydroforming steps.
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INTRODUCTION Oesophagectomy for cancer is a challenging procedure with a five-year overall survival rate of 15-20%. Early enteral nutrition following oesophagectomy is a crucial component of the postoperative recovery and carries ...
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INTRODUCTION Oesophagectomy for cancer is a challenging procedure with a five-year overall survival rate of 15-20%. Early enteral nutrition following oesophagectomy is a crucial component of the postoperative recovery and carries a significant impact on the outcome. Different methods of enteral feeding were conducted in our unit. The aim of this study was to examine the efficacy and safety of nasojejunal tube (NJT), jejunostomy tube (JT) and pharyngostomy tube (PT) feeding after oesophagectomy.
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BackgroundHome enteral tube feeding (HETF) is imperative for many infants and children with congenital heart disease (CHD). Tube weaning (TW) facilitates the progression from tube feeding to oral diet. There is limited literature ...
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BackgroundHome enteral tube feeding (HETF) is imperative for many infants and children with congenital heart disease (CHD). Tube weaning (TW) facilitates the progression from tube feeding to oral diet. There is limited literature on TW practices, protocols and success for children with CHD that have been tube fed.AimsThe objective of this study is to assess the process of weaning HETF in a tertiary referral centre for paediatric CHD. Specifically, we aimed to assess the duration of HETF, duration of TW and the interventions involved.MethodsWe retrospectively reviewed the medical and dietetic records of all infants and children that were successfully weaned off HETF over a 12-month period from January 2015 to December 2015.ResultsThere were 30 children included in the study, 9 boys and 21 girls. The diagnoses included 15 septal defects, 8 univentricular diagnosis and other diagnoses in 7 children. The median age at initiation of enteral tube feeding was 45days (range 2-169). The median duration to wean from enteral tube feeding was 52days (range 2-359). Number of dietetic consults required for successful TW varied among patients, median 5 (range 2-23). The number of days required for successful TW was associated with age and duration on HETF. Dietetic interventions included discontinuation of nutrient dense feeds, altering feed schedule and reduction of feed volume.ConclusionsWeaning HETF is possible in the outpatient setting. Early and frequent dietetic intervention is recommended to ensure prompt discontinuation of HETF when appropriate.
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AimThe Graz model of tube weaning has been internationally recognised as a successful and rapid tube weaning program. Beside the onsite treatment option, a telemedical counselling was specifically developed in 2009. This study aim...
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AimThe Graz model of tube weaning has been internationally recognised as a successful and rapid tube weaning program. Beside the onsite treatment option, a telemedical counselling was specifically developed in 2009. This study aims to show outcomes of this newly invented treatment in a large sample of patients.
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Between 2017 and 2019, the Smithsonian National Air and Space Museum acquired a collection of photoelectric tubes used in the earliest program of astronomical photoelectric photometry at the University of Wisconsin. The Wisconsin ...
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Between 2017 and 2019, the Smithsonian National Air and Space Museum acquired a collection of photoelectric tubes used in the earliest program of astronomical photoelectric photometry at the University of Wisconsin. The Wisconsin Collection of Photoelectric Detectors represents a unique look inside the development of a pioneering research project and a fledgling technology. The process by which techniques and technologies related to photoelectric photometry developed in the early twentieth century involved a variety of academic disciplines and commercial actors, and this process is reflected in the variety and specific features of the tubes in the collection. This paper attempts to situate the Wisconsin Collection within the wider development of photoelectric tubes as a technology, the development of observation techniques at Wisconsin, and their contributions to astronomical knowledge.
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Nurses are responsible for ensuring that short-term enteral feeding tubes are placed correctly before using them for gastric emptying, enteral nutrition, or medication administration. This article reviews evidence-based methods fo...
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Nurses are responsible for ensuring that short-term enteral feeding tubes are placed correctly before using them for gastric emptying, enteral nutrition, or medication administration. This article reviews evidence-based methods for assessing tube placement and discusses the limitations of each method with a focus on nasogastric tube placement.
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We present a study of the slowing of sound by a corrugated drainage pipe that serves as a straightforward project lab investigation for undergraduate students.
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Background The incidence of inflammatory cyst in the eustachian tube is very rare, and to the best of our knowledge, has not been reported in the literature. This article discusses a rare case of a large cyst originated from the e...
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Background The incidence of inflammatory cyst in the eustachian tube is very rare, and to the best of our knowledge, has not been reported in the literature. This article discusses a rare case of a large cyst originated from the eustachian tube, with a focus on discussing the differential diagnosis. Cysts located in the cartilaginous part of the eustachian tube can be removed successfully via transnasal endoscopic approach. Methods Case report and literature reviewCase Presentation: A 67 year old man presented for several months of left sided decreased hearing and aural fullness. Microscopic examination revealed left serous otitis media. Clinic endoscopic exam demonstrated a cyst in the left nasopharynx. Imaging and tissue sampling confirmed the cause was a large inflammatory cyst of the eustachian tube without sign of malignancy. He was successfully treated with left myringotomy with pose of pressure equalizing tube, and marsupialisation of the cyst via intranasal endoscopic approach. Conclusion Chronic eustachian tube dysfunction is a possible rare presentation of large eustachian tube cysts. It should be considered on the differential diagnosis for eustachian tube masses causing such dysfunction.
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