Sample records for eustachian tube

  1. [Balloon dilation of the Eustachian tube in pediatric chronic obstructive Eustachian tube dysfunction patients]. (United States)

    Maier, S; Tisch, M; Maier, H


    Balloon dilation of the Eustachian tube has recently been introduced as a novel and minimally invasive method for treating chronic obstructive Eustachian tube dysfunction. For the first time worldwide, we assessed the role of this technique in a large cohort of children with Eustachian tube dysfunction that did not respond to other treatments and in whom a tumor could be ruled out as the cause. This study is a retrospective analysis. We retrospectively analyzed the medical records of 66 children (mean age 8.12 years, range 4-14 years) who underwent balloon dilation of the Eustachian tube using the Bielefeld balloon catheter. There were no complications during surgery. Clinical symptoms improved in more than 80% of the patients. No patient reported a deterioration of symptoms. Of the participating parents, over 80% were very satisfied or satisfied with the treatment outcome. Balloon dilation is a rapid, simple, and safe method for treatment of both adults and children with Eustachian tube dysfunction that does not respond to other treatments. Further studies, ideally multicenter studies, are required in order to optimize the definition of existing and potential new indications for this treatment approach, as well as to establish this treatment in the management of children with refractory chronic Eustachian tube dysfunction.

  2. Can nasal decongestants improve eustachian tube function? (United States)

    Ovari, Attila; Buhr, Anne; Warkentin, Mareike; Kundt, Günther; Ehrt, Karsten; Pau, Hans-Wilhelm


    To evaluate the effect of nasal decongestants on eustachian tube (ET) opening. A prospective nonrandomized study. A tertiary referral center. Twenty-four patients (44 ears) with intact eardrums, 39 patients (43 ears) having a noninfected eardrum defect, and six patients with an upper airway infection. Nasal or intratympanal (in perforated ears) application of a nasal decongestant (xylometazoline 0.1%). Change of tube opening quality (yes or no; better or worse) measuring tube opening parameters (pressure, latency) using the Estève method and pressure equalization tests (swallowing at negative and positive external ear canal pressures). In most cases, nasal decongestion or intratympanal use of decongestants have no effect on ET opening. Improvement in tube opening is rather an exception and, in a minority of patients, a reduced ET function was evident. Our acute studies revealed no improvement in eustachian ventilatory tube function with the administration of nasal decongestants.

  3. Impact of evolution on the eustachian tube. (United States)

    Bluestone, Charles D


    I posit that humans appear to be the only species that develops otitis media. If animals in the wild had developed middle-ear disease to any significant degree, they would have been selected out during evolution because they would not have survived their predators given the associated hearing loss. Why do humans have otitis media? Evolution has had a significant impact. It is well known that humans are born 12 months too early, which is the result of adaptations to bipedalism and our big brain that, over time, resulted in a relatively small female pelvic outlet compared with nonhuman primates. As a consequence of too early a birth, not only is our immune system immature, but the eustachian tube is too short and floppy in the first year of life. But why is otitis media still common in older individuals? What other adaptation is uniquely human? We developed speech that was associated with descent of the larynx and hyoid bone, which, along with a decrease in prognathism (i.e., facial flattening), resulted in a change in palatal morphology as compared with other primates. Comparative anatomic and physiologic studies have demonstrated significant differences between humans and monkeys, especially in the muscles of the eustachian tube. Paradoxic constriction, as apposed to dilation, on swallowing is a common tubal dysfunction in humans and certain monkey models with chronic middle-ear effusion. My hypothesis is that chronic otitis media with effusion in patients with tubal constriction is a consequence of adaptation for speech and that, most likely, the levator veli palatini muscle is the cause.

  4. Epithelial differentiation in developing murine eustachian tube and middle ear. (United States)

    Park, K; Lee, Y D; Park, H J; Chun, Y M


    Detailed information on how an epithelial differentiation occurred in the developing eustachian tube and middle ear would be helpful in understanding both normal physiology and pathology of the tubotympanum. This study was undertaken to establish patterns of laminin and E-cadherin in the embryonic mouse eustachian tube and middle ear by use of immunohistochemistry at a stage when epithelial differentiation is taking place. This study was also designed to clarify the role of the middle ear mesenchyme. During the development of the eustachian tube, relatively high immunoreactivity to laminin was observed in the epithelium at gestational days 16 and 17, when the developments of ciliated and secretory cells were first observed. At the time of birth, in contrast to epithelium of the eustachian tube, epithelium of the middle ear cavity showed predominant expression of laminin and E-cadherin. These findings suggest that the expressions of laminin and E-cadherin may be correlated with maturation of the epithelium in the eustachian tube and middle ear and that the epithelial differentiation of the developing murine eustachian tube and middle ear may be controlled by epithelial-mesenchymal interaction and cell-to-cell interaction.

  5. Postpalatoplasty Eustachian tube function in young children with cleft palate. (United States)

    Alper, Cuneyt M; Losee, Joseph E; Mandel, Ellen M; Seroky, James T; Swarts, J Douglas; Doyle, William J


    To characterize Eustachian tube function using the forced response test in young children with cleft palate with or without cleft lip after palatoplasty with tympanostomy tubes inserted prepalatoplasty and compare these results with those of a 1986 study that evaluated a similar population using identical methods. Outpatient research clinic. A total of 34 children with cleft palate were tested at an average age of 18.6 ± 4.0 months. MAIN OUTCOME MEASUREs: Passive and active measures for the forced response test. Of the sample, 13 ears could not be tested, and tests on 24 ears were incomplete. The forced response test showed that the passive Eustachian tube function parameters were similar to those of normal adults and children. The percentage of ears that showed tubal dilation with swallowing was 60%. The active resistance and dilatory efficiency were similar to those of a normal adult population. A 1986 study of Eustachian tube function in postpalatoplasty subjects with cleft palate (37 ears) aged 15 to 26 months documented Eustachian tube dilation with swallowing in 84% of the ears. In the present study, which focused on a similar population, the frequency of tubal dilation was 60%. Nonetheless, both frequencies are significantly greater than the dilation frequency of 27% reported for 56 ears of subjects with cleft palate tested between 3 months and 18 years with tympanostomy tubes inserted for persistent otitis media with effusion. This suggests that dilation during the forced response test may be a prognostic marker for those children with cleft palate who will resolve their ear disease at an early age.

  6. Morphology and Ciliary Motion of Mucosa in the Eustachian Tube of Neonatal and Adult Gerbils


    Yi Li; Huizhan Liu; Jun Li; Qian Zhang; Shusheng Gong; David He


    The Eustachian tube is a small canal that connects the tympanic cavity with the nasal part of the pharynx. The epithelial lining of the Eustachian tube contains a ciliated columnar epithelium at the tympanic cavity and a pseudostratified, ciliated columnar epithelium with goblet cells near the pharynx. The tube serves to equalize air pressure across the eardrum and drains mucus away from the middle ear into the nasopharynx. Blockage of the Eustachian tube is the most common cause of all forms...

  7. The evaluation of the angles of Eustachian tubes in the patients with ...

    African Journals Online (AJOL)


    Dec 2, 2015 ... between COM with the eustachian tube anatomical and physiological abnormalities has been described in ... tube show us that the differences of the physiology of eustachian tube due to anatomical variants may ..... Descriptive anatomy of the human auditory tube. Surg Radiol Anat. 1998;20:335‑40. 18.

  8. Tensor veli palatini electromyography for monitoring Eustachian tube rehabilitation in otitis media. (United States)

    Picciotti, P M; Della Marca, G; D'Alatri, L; Lucidi, D; Rigante, M; Scarano, E


    The pathogenesis of otitis media is related to Eustachian tube dysfunction. The tensor veli palatini muscle actively opens the Eustachian tube and promotes middle-ear ventilation. This study describes a technique for paratubal electromyography that uses a surface, non-invasive electrode able to record tensor veli palatini muscle activity during swallowing. Twenty otitis media patients and 10 healthy patients underwent tensor veli palatini electromyography. Activity of this muscle before and after Eustachian tube rehabilitation was also assessed. In 78.5 per cent of patients, the electromyography duration phase and/or amplitude were reduced in the affected side. The muscle action potential was impaired in all patients who underwent Eustachian tube rehabilitation. This study confirmed that Eustachian tube muscle dysfunction has a role in otitis media pathogenesis and showed that muscle activity increases after Eustachian tube rehabilitation therapy.

  9. Imaging of the Eustachian tube and its function: a systematic review

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    Smith, M.E.; Tysome, J.R. [Cambridge University Hospitals NHS Foundation Trust, Department of ENT Surgery, Addenbrooke' s Hospital, Cambridge (United Kingdom); Scoffings, D.J. [Cambridge University Hospitals NHS Foundation Trust, Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)


    The Eustachian tube is a complex and inaccessible structure, which maintains middle ear ventilation to facilitate transmission of sound from the tympanic membrane to the cochlea. A renewed interest in treatments for eustachian tube dysfunction has led to a demand for methods of imaging the Eustachian tube, and assessing tube opening non-invasively. This review aims to summarise the use of imaging in the anatomical assessment of the Eustachian tube, and to explore how radiological techniques can be used to assess tube function. A systematic review of the literature was performed with narrative data analysis. With high-resolution images, the soft and bony anatomy of the Eustachian tube can be assessed in detail. CT and MRI are best suited to identifying features associated with obstructive or patulous Eustachian tube dysfunction, though true assessments of function have only been achieved with contrast enhanced radiographs and scintigraphy. A single modality has yet to provide a complete assessment. No test has entered routine clinical use, but further development and research is underway. Significant information can be gained from imaging the Eustachian tube, and as faster acquisition techniques are developed, it is possible that dynamic imaging of tubal opening could play an important role in the assessment of patients with ET dysfunction. (orig.)

  10. Structural changes in the rat middle ear mucosa due to endotoxin and eustachian tube obstruction. (United States)

    Nell, M J; Grote, J J


    The middle ears of 48 rats were used to examine the effects of endotoxin injection, eustachian tube obstruction or a combination of eustachian tube obstruction and endotoxin injection. Animals were killed after 1, 2, 4, or 12 weeks and the middle ears processed for light and scanning electron microscopy. Compared to the normal middle ear mucosa, the epithelial layer was more pseudostratified, cuboidal or cylindrical after endotoxin injection or obstruction of the eustachian tube. In the early phase, numerous ciliated cells occurred in areas originally almost devoid of these cells. At 3 months, degeneration of ciliated cells was observed. The combination of eustachian tube obstruction and endotoxin injection also induced a more pseudostratified, cuboidal or cylindrical epithelium with an increased number of goblet cells. However, an early decrease occurred in the number of ciliated cells in the tympanic orifice of the eustachian tube. Furthermore, inflammatory cells, mainly PMNs, macrophages and lymphocytes, invaded the subepithelial layer after eustachian tube obstruction and endotoxin injection. These structural changes resulted in an impairment of the mucociliary transport system for clearance of the middle ear cavity. For this reason we believe that both endotoxin and eustachian tube obstruction or dysfunction play an important role in inducing persistent mucosal changes in the middle ear cavity, thereby prolonging otitis media with effusion.

  11. Panel 2: Anatomy (Eustachian Tube, Middle Ear, and Mastoid-Anatomy, Physiology, Pathophysiology, and Pathogenesis). (United States)

    Alper, Cuneyt M; Luntz, Michal; Takahashi, Haruo; Ghadiali, Samir N; Swarts, J Douglas; Teixeira, Miriam S; Csákányi, Zsuzsanna; Yehudai, Noam; Kania, Romain; Poe, Dennis S


    Objective In this report, we review the recent literature (ie, past 4 years) to identify advances in our understanding of the middle ear-mastoid-eustachian tube system. We use this review to determine whether the short-term goals elaborated in the last report were achieved, and we propose updated goals to guide future otitis media research. Data Sources PubMed, Web of Science, Medline. Review Methods The panel topic was subdivided, and each contributor performed a literature search within the given time frame. The keywords searched included middle ear, eustachian tube, and mastoid for their intersection with anatomy, physiology, pathophysiology, and pathology. Preliminary reports from each panel member were consolidated and discussed when the panel met on June 11, 2015. At that meeting, the progress was evaluated and new short-term goals proposed. Conclusions Progress was made on 13 of the 20 short-term goals proposed in 2011. Significant advances were made in the characterization of middle ear gas exchange pathways, modeling eustachian tube function, and preliminary testing of treatments for eustachian tube dysfunction. Implications for Practice In the future, imaging technologies should be developed to noninvasively assess middle ear/eustachian tube structure and physiology with respect to their role in otitis media pathogenesis. The new data derived from these structure/function experiments should be integrated into computational models that can then be used to develop specific hypotheses concerning otitis media pathogenesis and persistence. Finally, rigorous studies on medical or surgical treatments for eustachian tube dysfunction should be undertaken.

  12. Morphology and ciliary motion of mucosa in the Eustachian tube of neonatal and adult gerbils. (United States)

    Li, Yi; Liu, Huizhan; Li, Jun; Zhang, Qian; Gong, Shusheng; He, David


    The Eustachian tube is a small canal that connects the tympanic cavity with the nasal part of the pharynx. The epithelial lining of the Eustachian tube contains a ciliated columnar epithelium at the tympanic cavity and a pseudostratified, ciliated columnar epithelium with goblet cells near the pharynx. The tube serves to equalize air pressure across the eardrum and drains mucus away from the middle ear into the nasopharynx. Blockage of the Eustachian tube is the most common cause of all forms of otitis media, which is common in children. In the present study, we examined the epithelial lining of the Eustachian tube in neonatal and adult gerbils, with a focus on the morphological and functional development of ciliated cells in the mucosa. The length of the tube is ∼8.8 mm in adult gerbils. Scanning electron microscopy showed that the mucosal member near the pharyngeal side contains a higher density of ciliated cells and goblet cells than that near the tympanic side. The cilia beat frequency is 11 Hz. During development, the length of the Eustachian tube increased significantly between postnatal day 1 (P1) and P18. Scanning electron microscopy showed that the mucosa contained a high density of ciliated cells with a few goblet cells at P1. The density of ciliated cells decreased while the density of goblet cells increased during development. At P18, the mucosa appeared to be adult-like. Interestingly, the ciliary beat frequency measured from ciliated cells at P1 was not statistically different from that measured from adult animals. Our study suggests that the Eustachian tube undergoes significant anatomical and histological changes between P1 and P18. The tube is morphologically and functionally mature at P18, when the auditory function (sensitivity and frequency selectivity) is mature in this species.

  13. Morphology and ciliary motion of mucosa in the Eustachian tube of neonatal and adult gerbils.

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    Yi Li

    Full Text Available The Eustachian tube is a small canal that connects the tympanic cavity with the nasal part of the pharynx. The epithelial lining of the Eustachian tube contains a ciliated columnar epithelium at the tympanic cavity and a pseudostratified, ciliated columnar epithelium with goblet cells near the pharynx. The tube serves to equalize air pressure across the eardrum and drains mucus away from the middle ear into the nasopharynx. Blockage of the Eustachian tube is the most common cause of all forms of otitis media, which is common in children. In the present study, we examined the epithelial lining of the Eustachian tube in neonatal and adult gerbils, with a focus on the morphological and functional development of ciliated cells in the mucosa. The length of the tube is ∼8.8 mm in adult gerbils. Scanning electron microscopy showed that the mucosal member near the pharyngeal side contains a higher density of ciliated cells and goblet cells than that near the tympanic side. The cilia beat frequency is 11 Hz. During development, the length of the Eustachian tube increased significantly between postnatal day 1 (P1 and P18. Scanning electron microscopy showed that the mucosa contained a high density of ciliated cells with a few goblet cells at P1. The density of ciliated cells decreased while the density of goblet cells increased during development. At P18, the mucosa appeared to be adult-like. Interestingly, the ciliary beat frequency measured from ciliated cells at P1 was not statistically different from that measured from adult animals. Our study suggests that the Eustachian tube undergoes significant anatomical and histological changes between P1 and P18. The tube is morphologically and functionally mature at P18, when the auditory function (sensitivity and frequency selectivity is mature in this species.

  14. Expression of water channel proteins (aquaporins) in the rat Eustachian tube and middle ear mucosa. (United States)

    Kang, Sung-Ho; Chang, Ki-Hong; Ohcho, Shuji; Lee, Haa-Yung; Cha, Kiweon; Moon, Sung-Kyun; Andalibi, Ali; Lim, David J


    Diverse expression of the different subtypes of aquaporins in different parts of the Eustachian tube and middle ear suggests region-specific functions of the aquaporins in the normal physiology of the tubotympanum and also suggests that they may play roles in the pathophysiology of otitis media. The epithelial cells of the middle ear and Eustachian tube must maintain adequate water balance for normal function of the mucociliary system. Since aquaporins (AQPs) are known to play critical roles in water homeostasis, we investigated their expression in the tubotympanum of the rat. The expression of AQP subtypes 1, 2, 4, 5, and 7 were examined in the rat Eustachian tube and middle ear using RT-PCR, Western blotting, and immunohistochemistry. Transcripts for AQP 1, 4, and 5 were detected in the Eustachian tube and middle ear. Expression of these molecules at the protein level was confirmed by Western blot analysis. Immunohistochemical analysis demonstrated that AQP 4 was localized to the basolateral membranes of ciliated epithelial cells while AQP 5 was localized to the apical surface of serous gland cells, but not goblet cells, in the rat Eustachian tube. AQP 1 was found to be expressed by the subepithelial fibroblasts.

  15. Middle Ear Pressure Regulation - Complementary Action of the Mastoid and Eustachian Tube

    DEFF Research Database (Denmark)

    Gaihede, Michael; Dirckx, Joris J J; Jacobsen, Henrik


    , MEP counter-regulation presented as Eustachian tube openings with steep and fast pressure changes toward 0 Pa, whereas in others, gradual and slow pressure changes presented related to the mastoid; these changes sometimes crossed 0 Pa into opposite pressures. In many cases, combinations...... to continuous regulation of smaller pressures, whereas the tube was related to intermittent regulation of higher pressures....

  16. Middle Ear Pressure Regulation - Complementary Action of the Mastoid and Eustachian Tube

    DEFF Research Database (Denmark)

    Gaihede, Michael; Jacobsen, Henrik; Tveterås, Kjell

    , MEP counter-regulation presented as Eustachian tube openings with steep and fast pressure changes toward 0 Pa, whereas in others, gradual and slow pressure changes presented related to the mastoid; these changes sometimes crossed 0 Pa into opposite pressures. In many cases, combinations...... to continuous regulation of smaller pressures, whereas the tube was related to intermittent regulation of higher pressures....

  17. [Observation of mucosa of eustachian tube with scanning electron microscope on spontaneous otitis media in mice]. (United States)

    Ma, Weijun; Hu, Juan; Cheng, Ying; Wang, Junli; Zhang, Xiaotong; Xu, Min


    To investigate the ultrastructural changes of the mucosa of eustachian tube in mice and to reveals the influence of eustachian tube on middle ear function and its relavence with otitis media. 12 wild type and 12 mutant mice were divided into two groups by age to observe the the ultrastructural changes of the mucosa of eustachian tube. Wild type mice exhibited a thick lawn of morphologically normal, distributed cilia in the mucosa of the middle ear at both time points. The cilia of mucosa of middle ear in mutant mice were short, impaired and disrupted. The impairment of the cilia progressed to a much great severity at 6 months compared to 3 months. Otitis media occurs not only the ciliated cells decreased and the goblet cells increased. More importantly, the ciliary structure was damaged, leading to the dysfunction of the mucociliary transport system and causing otitis media.

  18. Polydimethylsiloxane elastomer injection in the management of the patulous eustachian tube. (United States)

    Mackeith, S A C; Bottrill, I D


    To determine the effectiveness of augmentation surgery using polydimethylsiloxane elastomer injection for the management of patulous eustachian tube. All patients were treated with eustachian tube injection augmentation performed via a combined transnasal-transoral endoscopic approach. Clinical presentation, volume of injection, complications and initial response were all prospectively recorded. Longer-term follow up was conducted through structured telephone interviews using previously described patient-reported outcome measures. Overall, 8 of 11 patients (73 per cent) derived complete or significant symptom improvement; 1 patient had significant improvements but was dissatisfied, and in 2 patients the symptoms were unchanged. The eight satisfied patients showed improvement in their quality-of-life scores. This study describes an effective treatment option for patulous eustachian tube. Unlike many prior published reports, previously described patient-reported outcome measures were utilised in order to allow more direct comparison.

  19. Promising results after balloon dilatation of the Eustachian tube for obstructive dysfunction

    DEFF Research Database (Denmark)

    Wanscher, Jens H; Svane-Knudsen, Viggo


    INTRODUCTION: As the first ear, nose and throat department in Denmark, we introduced balloon dilatation of the Eustachian tube as a treatment of obstructive dysfunction in the summer of 2012. We present our preliminary experiences with this new treatment in adults. MATERIAL AND METHODS: Preoperat......INTRODUCTION: As the first ear, nose and throat department in Denmark, we introduced balloon dilatation of the Eustachian tube as a treatment of obstructive dysfunction in the summer of 2012. We present our preliminary experiences with this new treatment in adults. MATERIAL AND METHODS...

  20. Eustachian tube-tensor veli palatini muscle-cranial base relationships in children and adults: an osteological study. (United States)

    Doyle, William J; Swarts, J Douglas


    The vector relationships between the Eustachian tube, Tensor veli palatini muscle and cranial base constrain the efficiency of middle ear pressure-regulation and are required parameters for computational modeling of Eustachian tube function. Here, those relationships were reconstructed from skulls and compared between children and adults. Reconstructions were made using modifications of previously described techniques for 18 child skulls aged 3-4 years and 20 adult skulls (10 females, 10 males; >18 years). Measured and calculated variables were compared between groups using a Student's t-test. Consistent with previous reports, certain variables for adult skulls exhibited sexual dimorphism. Between children and adults, significant differences were documented for measures of cranial base length and width; hard palate width; nasopharyngeal height, width and depth; Eustachian tube length; the maximum and minimum Tensor veli palatini muscle lengths; the angles of deviation of the Tensor veli palatini muscle from the Eustachian tube, and the surface area of the Tensor veli palatini muscle. There were no between-group differences in the angle of Eustachian tube decent from the cranial base, Eustachian tube deviation from the parasagittal plane or the lateral component of the Tensor veli palatine muscle-Eustachian tube angle. The differences between children and adults that could account for the observed poorer Eustachian tube function in children include their shorter Eustachian tube, lesser Tensor veli palatine muscle-Eustachian tube vectors, and the lesser Tensor veli palatine muscle surface area. Other observed differences are attributable to growth and development of the craniofacial complex. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.


    NARCIS (Netherlands)


    A new method of anatomic dissection and image reconstruction using computer techniques for better understanding of eustachian tube (ET) functioning is presented. Coronal sections of two noncleft fetal skulls were photographed and projected on a graphic tablet. Contours of the pertinent structures

  2. Simple mass loading of the tympanic membrane to alleviate symptoms of patulous eustachian tube.

    NARCIS (Netherlands)

    Bartlett, C.; Pennings, R.J.E.; Ho, A.; Kirkpatrick, D.; Wijhe, R. Van; Bance, M.


    BACKGROUND: Patulous eustachian tube (PET) has a major impact on a patient's quality of life. The purpose of this study was to understand mechanisms behind the symptoms, develop treatments based on these, and develop and use a questionnaire to measure changes in PET symptoms with a novel

  3. Intranasal fluticasone associated with delayed tympanostomy tube placement in children with eustachian tube dysfunction. (United States)

    Crowson, Matthew G; Ryan, Marisa A; Ramprasad, Vaibhav H; Choi, Kevin J; Raynor, Eileen


    Pediatric patient caregivers may prefer to avoid a surgical intervention and request a medical management option for eustachian tube dysfunction (ETD). However, there are limited published data evaluating the efficacy of intranasal fluticasone in the medical management of ETD as an alternative to tympanostomy tube placement. The objectives of this study were to: 1) determine if intranasal fluticasone (INF) prevented tympanostomy tube placement in children with ETD, and 2) describe differences in patient response to INF related to cleft lip and/or palate (CLP) and Down syndrome. Case series with planned chart review at a Tertiary academic hospital. We reviewed pediatric patients treated with INF for ETD. Inclusion criteria included ETD, no prior intranasal or oral steroid therapy, and no prior tympanostomy tube placement. Outcomes included time-to- tympanostomy tube placement with or without INF and therapy compliance. Kaplan-Meier survival analyses with log-rank tests and Fisher's exact tests were used to examine outcome variables. 676 fulfilled inclusion criteria. 393 (58.7%) were male, and 355 (52.5%) Caucasian with mean age of 27.1 months old. 92 (13.6%) had CLP and 46 (6.8%) had Down Syndrome. 266 (39.4%) received INF, and 202 (88.2%) were compliant at their next visit. 474 (70.1%) had tympanostomy tubes placed. Children treated with INF were less likely to have tympanostomy tubes placed than children not treated (52.6% vs. 81.5%; p < 0.0001). Using survival analyses, INF use was associated with significantly longer mean time-to-tympanostomy tube than no INF use (199.4 vs. 133.7 days; p < 0.0001). INF did not reduce time-to-tympanostomy tube in patients with CLP (p = 0.05) or Down Syndrome (p = 0.27). INF significantly reduces the number of children requiring tympanostomy tube placement for ETD. The CLP and Down Syndrome anatomical variants may attenuate INF efficacy. Further in vivo characterization of INF action on eustachian tube tissues will help

  4. Myringotomy versus ventilation tubes in secretory otitis media: eardrum pathology, hearing, and eustachian tube function 25 years after treatment

    DEFF Research Database (Denmark)

    Caye-Thomasen, P.; Stangerup, S.E.; Jorgensen, G.


    , myringosclerosis and late atrophy. The temporary hearing improvement may reduce the risk of detrimental effects on speech and language development. The prevalence and extension of the various subtypes of pathology change over the years after treatment, which implies the existence of intrinsic repair mechanisms......OBJECTIVE: This report documents the dynamics of eardrum pathology, hearing acuity, and eustachian tube function during 25 years after treatment of bilateral secretory otitis media. The included children were treated by myringotomy on the left ear and ventilation tube insertion on the right ear...... not related to treatment. 7) Eustachian tube function at 25 years was not related to treatment. CONCLUSION: The insertion of a ventilation tube after myringotomy leads not only to better hearing until extrusion but also to an increased prevalence of long-term pathologic changes of the eardrum, that is...

  5. An Eustachian Tube Neuroendocrine Carcinoma: A Previously Undescribed Entity and Review of the Literature

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    Gavin J. le Nobel


    Full Text Available Primary sinonasal and middle ear neuroendocrine carcinomas are rare malignancies of the head and neck. Owing to the rarity of these tumors, the clinical behavior and optimal management of these tumors are not well defined. We present a case of an incidentally discovered sinonasal neuroendocrine carcinoma that was found to originate from the Eustachian tube, which has not previously been described in the literature. This patient was treated with primary surgical resection using a combination of transnasal and transaural approaches and achieved an incomplete resection. Follow-up imaging demonstrated continued tumor growth in the Eustachian tube as well as a new growth in the ipsilateral cerebellopontine angle and findings suspicious of perineural invasion. However, the tumor exhibited a benign growth pattern and despite continued growth the patient did not receive additional treatment and he remains asymptomatic 35 months following his original surgery.

  6. Functional MR imaging of the Eustachian tube in patients with clinically proven dysfunction: correlation with lesions detected on MR images

    Energy Technology Data Exchange (ETDEWEB)

    Luekens, Anna; Guenther, Rolf W. [University Hospital, University of Technology (RWTH) Aachen, Department of Diagnostic Radiology, Aachen (Germany); DiMartino, Ercole [Ev. Diakonie-Krankenhaus, Department of Otolaryngology and Head- and Neck-Surgery, Bremen (Germany); Krombach, Gabriele A. [University Hospital, University of Technology (RWTH) Aachen, Department of Diagnostic Radiology, Aachen (Germany); University Hospital Giessen, University Giessen, Department of Diagnostic and Interventional Radiology, Giessen (Germany)


    To visualise the function of the Eustachian tube by MRI and assess the effect of surrounding lesions. Using 1.5 T MRI, 32 Eustachian tubes of 16 patients with clinically proven dysfunction (clinical symptoms, such as autophonia and fullness and non-opening at tympanometry) were investigated. For depiction of the anatomy and associated abnormalities, coronal and axial T2-weighted turbo spin echo sequences and a T1-weighted-2D-gradient echo sequences were acquired. Eustachian tube opening was analysed with real time turbo-gradient echo sequences during a Valsalva manoeuvre. Dysfunction, that is, failure of opening of the Eustachian tube as shown by MRI, correlated in all patients with tympanometry. Lesions detected included nasopharyngeal carcinoma in 4 patients. Mucosal swelling in the paranasal sinus was present in 9 patients. One patient had postoperative defects. In two patients both pharyngotympanic tubes did not open although no structural abnormalities could be depicted. The opening of the Eustachian tubes during the Valsalva manoeuvre is assessable on MRI. Failure of opening may be due to swelling of the mucosa and may be also associated with tumours. MRI assessment may be helpful in patients with chronic otitis media, where the information about tubal function is important in preoperative planning. (orig.)

  7. The evaluation of the angles of Eustachian tubes in the patients with chronic otitis media on the temporal computerized tomography. (United States)

    Aksoy, S; Sayin, I; Yazici, Z M; Kayhan, F T; Karahasanoglu, A; Hocaoglu, E; Inci, E


    Chronic otitis media (COM), affecting all over the world and in a wide range of age groups in Turkey, is an important cause of ear discharge and hearing loss. The main clinical manifestations are tympanic membrane perforation, ear, nose and throat problems. On the tympanic membrane perforation becomes persistent and cholesteatoma development, there are a lot of opinions today. Especially in the pathology associated with otitis media with effusion eustachian tube, it is known that COM and cholesteatoma develop. In our study, we interpreted 210 patients' temporal computed tomography (CT). Seventy of these 210 patients had otitis media with cholesteatoma, 70 patients had only otitis media without cholesteatoma, and 70 patients had no otitis media. The eustachian tubes were evaluated using temporal CT multiplanar reconstruction method. Angles with the horizontal plane of the eustachian tube and Reid and tubotympanic angles were measured. The angles between eustachian tube and horizontally oriented Reid plane of the patients with cholesteatoma were found to be significantly lower than the patients with otitis media without cholesteatoma and the patients with no history of otitis media. For the tubotympanic angle, no statistically significant differences were observed between the groups. These results suggest that the decrease in the angle with the horizontal plane of Reid in the eustachian tube in adults may play a significant role in the etiology of cholesteatoma.

  8. Treatment of middle ear ventilation disorders: sheep as animal model for stenting the human Eustachian tube--a cadaver study.

    Directory of Open Access Journals (Sweden)

    Felicitas Miller

    Full Text Available Eustachian tube disorders can lead to chronic otitis media with consecutive conductive hearing loss. To improve treatment and to develop new types of implants such as stents, an adequate experimental animal model is required. As the middle ear of sheep is known to be comparable to the human middle ear, the dimensions of the Eustachian tube in two strains of sheep were investigated. The Eustachian tube and middle ear of half heads of heathland and blackface sheep were filled with silicone rubber, blended with barium sulfate to induce X-ray visibility. Images were taken by digital volume tomography. The tubes were segmented, and a three-dimensional model of every Eustachian tube was generated. The lengths, diameters and shapes were determined. Additionally, the feasibility of endoscopic stent implantation and fixation was tested in cadaver experiments. The length of the tube between ostium pharyngeum and the isthmus and the diameters were comparable to published values for the human tube. The tube was easily accessible through the nose, and then stents could be implanted and fixed at the isthmus. The sheep appears to be a promising model for testing new stent treatments for middle ear ventilation disorders.

  9. Developmental anatomy of the eustachian tube and middle ear in mice. (United States)

    Park, K; Ueno, K; Lim, D J


    It is generally accepted that the development of the tubotympanum has significant bearing on the susceptibility to ear infection. A detailed study of the differentiation of ciliated cells in secretory elements will be useful in understanding both the normal physiology and the pathology of the tubotympanum. Serially sectioned temporal bones of 76 mice ranging from gestational age day 11 to postnatal day 21 were examined microscopically. During the period of gestation, the tubotympanic recess was formed at the 12th day and began to extend to form the middle ear between the 13th and 14th days. A rapid increase in the volume of the tubotympanic recess was observed between the 15th and 16th days when a definitive division of the tubotympanic recess into the eustachian tube and middle ear cavity was observed. Postnatally the tubotympanum attained an adult form around day 9, and the maximum change of middle ear volume was noted on day 11, when the mesenchymal tissue in the middle ear cavity disappeared completely. Development of the ciliated cells was observed concurrently in both the eustachian tube and middle ear on the 16th gestational day, one day earlier than the appearance of the epithelial secretory cells in both the eustachian tube and middle ear. The number of ciliated cells and secretory cells increased rapidly after birth. Tubal glands were well developed with evidence of secretory activity around the time of birth. Based on these findings, one can conclude that the mucociliary defense system starts to develop during the fetal stage and is well established immediately after birth.

  10. Evidence and evidence gaps in the treatment of Eustachian tube dysfunction and otitis media (United States)

    Teschner, Magnus


    Evidence-based medicine is an approach to medical treatment intended to optimize patient-oriented decision-making on the basis of empirically proven effectiveness. For this purpose, a classification system has been established to categorize studies – and hence therapy options – in respect of associated evidence according to defined criteria. The Eustachian tube connects the nasopharynx with the middle ear cavity. Its key function is to ensure middle ear ventilation. Compromised ventilation results in inflammatory middle ear disorders. Numerous evidence-based therapy options are available for the treatment of impaired middle ear ventilation and otitis media, the main therapeutic approach being antibiotic treatment. More recent procedures such as balloon dilation of the Eustachian tube have also shown initial success but must undergo further evaluation with regard to evidence. There is, as yet, no evidence for some of the other long-established procedures. Owing to the multitude of variables, the classification of evidence levels for various treatment approaches calls for highly diversified assessment. Numerous evidence-based studies are therefore necessary in order to evaluate the evidence pertaining to existing and future therapy solutions for impaired middle ear ventilation and otitis media. If this need is addressed, a wealth of implications can be expected for therapeutic approaches in the years to come. PMID:28025605

  11. Identifying eustachian tube dysfunction prior to hyperbaric oxygen therapy: Who is at risk for intolerance? (United States)

    Cohn, Jason E; Pfeiffer, Michael; Patel, Niki; Sataloff, Robert T; McKinnon, Brian J

    Determine whether specific risk factors, symptoms and clinical examination findings are associated with hyperbaric oxygen therapy (HBOT) intolerance and subsequent tympanotomy tube placement. A retrospective case series with chart review was conducted from 2007 to 2016 of patients undergoing HBOT clearance at a tertiary care university hospital in an urban city. Eighty-one (n=81) patient charts were reviewed for risk factors, symptoms and clinical examination findings related to HBOT eustachian tube dysfunction and middle ear barotrauma. Relative risk was calculated for each variable to determine risk for HBOT intolerance and need for tympanotomy tube placement. Risk factor, symptom, physical examination and HBOT complication-susceptibility scores were calculated for each patient. Mean risk factor, clinical and HBOT complication-susceptibility scores were significantly higher in patients who did not tolerate HBOT compared to patients who tolerated HBOT. Patients reporting a history of otitis media, tinnitus, and prior ear surgery were at a higher risk for HBOT intolerance. Patients reporting a history of pressure intolerance and prior ear surgery were more likely to undergo tympanotomy tube placement. Patients noted to have otologic findings prior to HBOT were at a higher risk for both HBOT intolerance and tympanotomy tube placement. A thorough otolaryngological evaluation can potentially predict and identify patients at risk for HBOT intolerance and tympanotomy tube placement. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. [The treatment effect of eustachian tube atresia with laser and connical plastic tube after radiotherapy for nasopharyngeal carcinoma]. (United States)

    Gao, H G; Tong, J; Chen, W W


    Objective: To investigate the method in treatment of Eustschian tube atresia caused by radiotherapy. Methods: Two cases diagnosed of Eustschian tube atresia following radiotherapy were retrospectively analyzed in Department of Otorhinolaryngology, Divided Hospital of Shanghai University Communication Affiliated First People Hospital in Apr. 2014 and Oct. 2015. Both cases were female, 65 and 64 years old, and accepted radiotherapy six and 20 years ago respectively. The pharyngeal orifices of Eustschian tube were found to be totally closed under endoscope. The closed Eustschian tubes were re-opened by laser and re-shaped by a slim and conical plastic tube for more than six months. They were followed up and evaluated over 12 months. Results: At six and 12 months after treatment, round mouths were formed in the pharyngeal orifice of Eustachian tube, and the patients had no resistance in Valsalva's test. No shrink or abnormal opening of orifice was found at follow-up of 20 and 12 months. Conclusion: The method of re-opening by laser and re-shaping by a slim and conical plastic tube is recommended to treat Eustschian tube occlusion caused by radiotherapy.

  13. Assessment of nasal-noise masking audiometry as a diagnostic test for patulous Eustachian tube. (United States)

    Paradis, Justin; Bance, Manohar


    The primary objective is to assess the validity of nasal-noise masking audiometry (NNMA) as a clinical diagnostic tool in our patient population. Retrospective case review. Tertiary ambulatory referral center. Patients with patulous Eustachian tube (PET) were identified from referrals to our Eustachian tube disorders clinic primarily with symptoms including autophony, aural fullness, and hearing their own breathing. The healthy subjects had no history of ear disease. NNMA was measured in 20 ears of 10 healthy subjects as well as in 42 ears of 21 patients with suspected PET. NNMA mean auditory thresholds were measured at frequencies ranging from 250 to 8,000 Hz. When stratified as definitive or probable PET based on observed tympanic membrane movement with breathing, both Definitive and Probable PET groups had significantly higher NNMA mean auditory thresholds compared to Normal ears at 250 Hz (p = 0.001, p = 0.003), 1,000 Hz (p = 0.019, p = 0.001), and 6,000 Hz (p = 0.4, p = 0.001). When stratified based on symptoms on the day of testing, both Symptomatic Ears and Non-Symptomatic Ears had significantly higher mean auditory thresholds compared to Normal ears at 250 Hz (p = 0.001, p = 0.015) and at 1,000 Hz (p = 0.002, p = 0.004). Our results demonstrate a larger masking effect in patients with PET compared to normal subjects in the low-frequency region. In clinical practice, the relatively small effect and the wide variability of results between patients have made this test be of little value clinically in our patient population.

  14. The structure of the middle ear epithelium of the rat and the effect of Eustachian tube obstruction. (United States)

    Kuijpers, W; van der Beek, J M; Jap, P H; Tonnaer, E L


    The middle ear cavity of the rat is lined with ciliated and squamous epithelium. The arrangement of the ciliated cells, interspersed with secretory cells, in distinct tracts and their continuity with the ciliated epithelium of the Eustachian tube, suggests the existence of a mucociliary transport system for cleaning the middle ear cleft. The secretory cells produce either neutral or sulphated glycoproteins, dependent on their location. In addition to these secretions, the epithelium of the lower part of the Eustachian tube is bathed with secretory products of seromucous glands. Also in the areas with squamous epithelium, numerous small secretory cells, the character of which is only identifiable with the electronmicroscope, are present. It is concluded that the middle ear lining can be considered as a locally modified respiratory epithelium. Blockade of the mucociliary transport system, supposedly a crucial aetiological factor in secretory otitis media, by obstruction of the Eustachian tube, induces pathogenic behaviour of microorganisms normally present in the middle ear. This results in either a transient or a longstanding infective middle ear disease, associated with a large variety of changes of the mucosa, especially with respect to the secretory activity. The data obtained indicate that the increased secretory activity encountered in secretory otitis media cannot be attributed to the isolated effect of tubal occlusion, but rather to an infective process.

  15. Endonasal dilatation of the Eustachian tube (EET) in children: feasibility and the role of tubomanometry (Estève) in outcomes measurement. (United States)

    Jenckel, Friederike; Kappo, Natalie; Gliese, Alexandra; Loewenthal, Maureen; Lörincz, Balazs B; Knecht, Rainald; Dalchow, Carsten V


    Studies on endonasal dilatation of the Eustachian tube (EET) utilizing a balloon catheter have shown encouraging results over the last years. This retrospective analysis presents our outcomes with EET in children with chronic obstructive dysfunction of the Eustachian tube, as well as the role of tubomanometry (TMM, Estève) as a diagnostic tool in the pre- and postoperative assessment of the Eustachian tube (ET) dysfunction. The data of 33 children, having undergone EET between September 2010 and March 2014, were retrospectively evaluated. They were assessed using tubomanometry before and after the EET. The R-data as the rate of Eustachian tube function in tubomanometry (TMM) were pre- and postoperatively matched with the clinical outcomes. Moreover, the patients' complaints before and after the procedure were analyzed. We did not see any EET-related complications in children. Most patients noticed a relief of their complaints. In the same time, tubomanometry was not able to show improved tube function or favorable postoperative changes in the R-data. Ear-related symptoms (e.g. otorrhea, otalgia, hearing loss) have been improved. EET is a feasible method in adults as well as in children to treat chronic tube dysfunction. However, tubomanometry does not seem to be the adequate tool to evaluate the tube function and thus the success rate of EET in children with chronic dysfunction of the Eustachian tube.

  16. Cross-platform data integration of paratubal electromyography and sonotubometry for eustachian tube: a pilot study. (United States)

    Lin, Chenxi; Li, Yanning; Lin, Xin; Zhang, Shaohua; Tang, Anzhou; Nong, Dongxiao


    The sensitive sonotubometry and MATLAB provide a new tool to study the eustachian tube (ET) function and contribute more to reliable data and precise analysis. The levator veli palatini muscle (mLVP) and the salpingopharyngeus muscle (mSP) may, respectively, be the most important and least important muscle for ET function. The ET lumen dilation is a result of the contraction of the paratubal muscles, the tensor veli palatini muscle (mTVP), mLVP and mSP. To trace the dynamic ET muscle/lumen activities, the present study aimed to optimize sonotubometry and achieve cross-platform data integration of electromyography (EMG) and sonotubometry using MATLAB (matrix laboratory). Seventeen healthy volunteers (34 ears) were chosen for the concurrent recordings of the paratubal EMG and sonotubogram under dry and water swallowing. The optimized sonotubometry based on computer sound card showed satisfied sensitivity. For both EMGs and sonotubogram, dry swallowing generated significantly greater amplitude and longer duration compared to water swallowing. Moreover, statistically significant differences (p < 0.05) were detected in the comparison of the amplitude, duration, and latency for the mTVP, mLVP, and mSP. The mSP activity was the weakest and even inactive in some cases, the mLVP presented the most powerful and long lasting activity during ET-opening.

  17. Eustachian Tube Obliteration and its Effect on Rhinoliquorrhea in Translabyrinthine Vestibular Schwannoma Excision. (United States)

    Moderie, Christophe; Maniakas, Anastasios; Moumdjian, Robert; Alhabib, Salman F; Saliba, Issam


    Rhinoliquorrhea is defined as a cerebrospinal fluid leakage from the nose. Our objective in this study is to determine the reduction of rhinoliquorrhea rates by Eustachian tube (ET) obliteration in the context of a translabyrinthine approach performed following vestibular schwannoma (VS) excision. This is a prospective study achieved in a tertiary-care center where the chart review revealed 94 VS operated by the translabyrinthine approach between 2009 and 2015. There were 40 males and 54 females aged from 28-76 years. The only exclusion criterion was a previous history of cranial surgery. ET obliteration was systematically executed when the petrous apex pneumatization level was at least 2 of 4. Our main outcome measure was the development of rhinoliquorrhea. Eighty-eight patients underwent ET obliteration and were followed for an average of 2.6±1.2 years. Rhinoliquorrhea was reported in 1.14% of the patients having had an ET obliteration. When compared to our previous sample of patients operated with a translabyrinthine approach, it represents a reduction of 84%. Obliteration of the ET is a fast and simple procedure that reduces the rate of rhinoliquorrhea. We therefore recommend its use, specifically in cases of petrous apex pneumatization levels 2-4.

  18. Assessment of Eustachian tube function in patients with tympanic membrane retraction and in normal subjects. (United States)

    Canali, Inesângela; Petersen Schmidt Rosito, Letícia; Siliprandi, Bruno; Giugno, Cláudia; Selaimen da Costa, Sady

    The diagnosis of Eustachian tube dysfunctions is essential for better understanding of the pathogenesis of chronic otitis media. A series of tests to assess tube function are described in the literature; however, they are methodologically heterogeneous, with differences ranging from application protocols to standardization of tests and their results. To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal patients during tube function tests, as well as to evaluate intra-individual variation between these tests. An observational, contemporary, cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, sniff test, Toynbee maneuver) in healthy patients and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears) were included in the study. Patients underwent tube function tests at two different time points to determine pressure measurements after each maneuver. Statistical analysis was performed using SPSS software, version 18.0, considering p-values <0.05 as statistically significant. Mean (standard deviation) age was 11 (2.72) years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher among participants with healthy ears and those with mild retraction, whereas type C tympanograms were more frequent in the moderate/severe retraction group. An increase in middle ear pressure was observed during the Valsalva maneuver at the first time point evaluated in all three groups of ears (p=0.012). The variation in pressure was not significant either for the sniff test or for the Toynbee maneuver at the two time points evaluated (p≥0.05). Agreement between measurements obtained at the two different time points was weak to moderate for all tests in all three groups of ears, and the variations in discrepancy between measurements were higher in ears

  19. Assessment of Eustachian tube function in patients with tympanic membrane retraction and in normal subjects,

    Directory of Open Access Journals (Sweden)

    Inesângela Canali

    Full Text Available Abstract Introduction The diagnosis of Eustachian tube dysfunctions is essential for better understanding of the pathogenesis of chronic otitis media. A series of tests to assess tube function are described in the literature; however, they are methodologically heterogeneous, with differences ranging from application protocols to standardization of tests and their results. Objective To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal patients during tube function tests, as well as to evaluate intra-individual variation between these tests. Methods An observational, contemporary, cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, sniff test, Toynbee maneuver in healthy patients and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears were included in the study. Patients underwent tube function tests at two different time points to determine pressure measurements after each maneuver. Statistical analysis was performed using SPSS software, version 18.0, considering p-values <0.05 as statistically significant. Results Mean (standard deviation age was 11 (2.72 years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher among participants with healthy ears and those with mild retraction, whereas type C tympanograms were more frequent in the moderate/severe retraction group. An increase in middle ear pressure was observed during the Valsalva maneuver at the first time point evaluated in all three groups of ears (p = 0.012. The variation in pressure was not significant either for the sniff test or for the Toynbee maneuver at the two time points evaluated (p ≥ 0.05. Agreement between measurements obtained at the two different time points was weak to moderate for all tests in all three groups of ears, and the

  20. Secretory otitis. Histopathology and goblet-cell density in the Eustachian tube and middle ear in children. (United States)

    Tos, M; Bak-Pedersen, K


    The histological changes in the middle ear of four children with incipient or mild chronic secretory otitis are described. They consist in vascular dilatation and proliferation, round-cell infiltration, epithelial metaplasia into pseudostratified, columnar, ciliated epithelium posteriorly in the middle ear, formation of abnormal mucous tubular glands, and an increase in goblet-cell density in the osseous tube and middle ear. The causes of these changes were presumably long-lasting tubal occlusion due to a permanent nasogastric tube and protracted catarrhal diseases. The density of goblet cells was determined in various parts of the Eustachian tube and middle ear. The findings were analysed statistically and compared with the density in prematures and newborns, normal children, and normal adults. In the tympanic orifice and in the osseous Eustachian tube the goblet-cell density was greatly increased, whereas the increase in the middle ear varied individually, but was in conformity with the other findings. These cases illustrate that the histopathological changes in the middle-ear mucosa in secretory otitis must be regarded not only from a qualitative, but certainly also from a quantitative point of view.

  1. Multi-scale finite element modeling of Eustachian tube function: influence of mucosal adhesion. (United States)

    Malik, J E; Swarts, J D; Ghadiali, S N


    The inability to open the collapsible Eustachian tube (ET) leads to the development of chronic Otitis Media (OM). Although mucosal inflammation during OM leads to increased mucin gene expression and elevated adhesion forces within the ET lumen, it is not known how changes in mucosal adhesion alter the biomechanical mechanisms of ET function. In this study, we developed a novel multi-scale finite element model of ET function in adults that utilizes adhesion spring elements to simulate changes in mucosal adhesion. Models were created for six adult subjects, and dynamic patterns in muscle contraction were used to simulate the wave-like opening of the ET that occurs during swallowing. Results indicate that ET opening is highly sensitive to the level of mucosal adhesion and that exceeding a critical value of adhesion leads to rapid ET dysfunction. Parameter variation studies and sensitivity analysis indicate that increased mucosal adhesion alters the relative importance of several tissue biomechanical properties. For example, increases in mucosal adhesion reduced the sensitivity of ET function to tensor veli palatini muscle forces but did not alter the insensitivity of ET function to levator veli palatini muscle forces. Interestingly, although changes in cartilage stiffness did not significantly influence ET opening under low adhesion conditions, ET opening was highly sensitive to changes in cartilage stiffness under high adhesion conditions. Therefore, our multi-scale computational models indicate that changes in mucosal adhesion as would occur during inflammatory OM alter the biomechanical mechanisms of ET function. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Do the angle and length of the eustachian tube influence the development of chronic otitis media? (United States)

    Dinç, Aykut Erdem; Damar, Murat; Uğur, Mehmet Birol; Öz, Ibrahim Ilker; Eliçora, Sultan Şevik; Bişkin, Sultan; Tutar, Hakan


    To compare the eustachian tube (ET) angle (ETa) and length (ETl) of ears with and without chronic otitis media (COM), and to determine the relationship between ET anatomy and the development of COM. A retrospective case-control study. The study group comprised 125 patients (age range, 8-79 years; 64 males and 61 females) with 124 normal ears and 126 diseased ears, including ears with chronic suppurative otitis media (CSOM) with central perforation, intratympanic tympanosclerosis (ITTS), cholesteatoma, and a tympanic membrane with retraction pockets (TMRP). ET angle and length were measured using computed tomography employing the multiplanar reconstruction technique. The ETa was significantly more horizontal in diseased versus normal ears of all study groups (P = .030), and there was no group difference in ETl (P = .160). ETl was shorter in CSOM versus ITTS ears and normal ears (P = .007 and P = .003, respectively) and in cholesteatoma versus TMRP ears (P = .014). In the unilateral COM group, there were no significant differences in the ETa or ETl of diseased versus contralateral normal ears (P = .155 and P = .710, respectively). The ETa was significantly more horizontal in childhood-onset diseased versus normal ears (P = .027), and there was no group difference in ETl (P = .732). The ETa (P = .002) and ETl (P ETl could be contributory (though not significantly) etiological factors in the development of COM. 3b. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  3. Diagnostic accuracy of tubomanometry R value in detecting the Eustachian tube pressure equalizing function. (United States)

    Alper, Cuneyt M; Teixeira, Miriam S; Kim, Jeehong H; Douglas Swarts, J


    Tubomanometry is a relatively novel Eustachian tube (ET) function testing method. A number of recent studies have utilized the R value of Tubomanometry as the main objective measure in reporting their outcome in balloon dilation of ET. There is, however, a lack of evidence concerning the reliability or validity of Tubomanometry measurements. The objectives of this study are to determine the accuracy of Tubomanometry for detecting ET opening as compared to tympanometry and determine its usefulness as a measure of ET function. Healthy subjects between ages 8 and 76 years with an intact tympanic membrane and no middle ear (ME) effusion were prospectively tested. Primary outcomes were the ET opening as determined by the Tubomanometry R value and the increase in ME pressure with tympanometry-measured in relation to a swallow at a nasopharyngeal pressure of 300 daPa. The accuracy of the tubomanometry R value for identifying a successful ET opening was made in reference to the change of ME pressure. A total of 280 measurements were available from 258 ears in 137 subjects. The presence of tubomanometry R value showed high sensitivity of detecting ET opening for the criteria of >5 daPa ME pressure increase (187/202) but low specificity for detecting ET non-opening (34/78). The R value criterion described in the original manuscripts on Tubomanometry is sensitive but not specific for ET opening. The need for validation of the tubomanometry test obviates its use as the main objective outcome measure for the balloon dilation of ET procedure.

  4. [The condition of the Eustachian tube and its influence on the middle ear]. (United States)

    Zechner, G


    Any functional disturbance in the auditory tube may be documented morphologically. We demonstrated in case of a block changes within the tubal mucosa and in the adjacent salivary glands. Complete obliteration of the lumen is a very rare instance caused only by severe trauma or as a possible result of heavy inflammatory damage to the mucosa. A lack of ventilation produces in the tympanic cleft a vacuum, followed by a typical effusion out of the altered mucosa. Anaerobic conditions favour hyper and metaplastic transformation of the epithelium. The clinical picture resembles the non-purulent, closed form of otitis, serous otitis media. The missing clearance makes the discharge within the tympanic cleft a great challenge to the mucosa. Granulation tissue proliferates, an enzyme production is initiated and phagocytes help to eliminate or to organize the middle ear content. The clinical picture corresponds to otitis media adhaesiva. If the auditory tube is blocked long enough, the healing result leads to the atelectatic tympanon caused by scare tissue, dystrophic calcification, fatty degeneration of granulation tissue, fibrocystic transformation of the mucosa. The ossicular chain, if not destroyed or interrupted, is fixed. A very dangerous condition is caused by retractionpockets within the ear drum membrane. They give rise to secondary acquired cholesteatoma. In the beginning of the whole process we see the nonfunctioning auditory tube, provoked by an infection. The development of the tubal tonsil and the perivascular aggregations of immunocompetent cells lead to the opinion, that the tube is an immunological not only a mechanical barrier against ascending infections. Favoured by antibiotic treatment the inflammation is localized by the body's own defence within the tympanic tube and causes the blockage, the loss of function, which influences heavily the middle ear and its lining.

  5. Changes in microvascular permeability of the middle ear mucosa following the occulsion of the eustachian tube of rabbits. The functional investigation using radioisotope

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    Kikuchi, Yasutaka


    Serial changes in submucosal microvascular permeability of the middle ear and the response to histamine after occlusion of the eustachian tube were functionally investigated using radioisotope in rabbits with experimentally induced otitis media with effusion. Tritium water was administered through intravenous injection and transference of tritium water into the middle ear cavity was measured by radioactivity of the middle ear perfusate. Morphological changes were concurrently examined for comparison. Vascular permeability, as measured one, 7, and 14 days after occlusion of the eustachian tube, increased with time. A histological study showed an edematous hypertrophy of the submucosal tissue of the middle ear, suggesting a noticeable increase in microvascular permeability. The response of the middle ear mucosa to histamine, which was added to the fluid for perfusion, gradually decreased after occlusion of the eustachian tube, although the effect of histamine tended to persist for a long time, irrespective of the amount of administration. The results indicated that the mucosal membrane of the middle ear has a noticeable permeability at least up to 14 days after occlusion, and that histamine may be responsible for the increase of submucosal microvascular permeability not only in the normal middle ear cavity but also in otitis media with effusion which results in the persistance of the disease. The presence of factors permeable to the blood, other than histamine, caused microvascular peameability to increase, probably resulting in chronic or irreversible inflammation. This may be explained by markedly proliferative or parenchymatous connective tissues observed 7 and l0 weeks after occlusion. It should be noted that surgical treatment be performed as early as possible in the case of otitis media with effusion. (Namekawa, K) 80 refs.

  6. Middle ear ventilation status postoperatively after translabyrinthine resection of vestibular schwannoma with mastoid obliteration and Eustachian tube occlusion: is the Eustachian tube enough to ventilate the middle ear without the mastoid air cell system? (United States)

    Belyea, James; Wickens, Brandon; Bance, Manohar


    Gas pressure balance is essential for maintaining normal middle ear function. The mucosal surfaces of the middle ear, the mastoid air cell system (MACS), and the Eustachian tube (ET) play a critical role in this process; however, the extent that each of these factors contributes to overall middle ear ventilation is unknown. The objective of this study was to determine if the ET alone can maintain normal middle ear pressure without the MACS. To do this, we reviewed subjects who had their MACS completely removed with translabyrinthine (TL) surgery for vestibular schwannoma. A retrospective chart review was done to collect pre and postoperative tympanometry data from patients who underwent resection of vestibular schwannoma. Data from the operative side was compared to the non-operative side at 2 years post-op. Twenty-four patients were included in this study. Of these, 63 % achieved a type A tympanogram at 2 years post-op in the TL resection group, implying an ability to maintain middle ear pressure in the absence of a mastoid cavity. Because some had negative pressures post TL resection, the average change in pre and postoperative pressure was -37.5 daPa for the operative side and 7.8 daPa for the non-operative side. This was significantly different. The difference for change in pre and postoperative pressure and compliance between operative and non-operative side might be expected from the ET plugging during TL resection. However, more interesting are those patients in whom the ET presumably reopens, and in these subjects, despite having no mastoid compartment at all, and the space obliterated with fat, they were still able to maintain normal ventilation of the middle ear space. Our findings imply that the ET alone is adequate to ventilate at least the reduced middle ear space following TL surgery in most subjects, and perhaps in 100 % if the ET hadn't been plugged during surgery. Hence, the mastoid air cell system, even when healthy, is not needed to maintain

  7. Eustachian Tube Dysfunction (United States)

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  8. Do the Angle and Length of the Eustachian Tube Affect the Success Rate of Pediatric Cartilage Type 1 Tympanoplasty? (United States)

    Yegin, Yakup; Çelik, Mustafa; Altintaş, Ahmet; Çolak, Ceylan; Kayhan, Fatma Tülin


    To investigate the relationships between the angle and length of the Eustachian tube (ET) (the ETa and the ETl) and the success rates of pediatric type 1 tympanoplasty. A retrospective clinical chart review. In total, 51 children (31 females and 20 males; average age, 11.92 ± 3.46 years; age range: 7-18 years) who underwent cartilage type 1 tympanoplasty were included. Demographics and anatomical outcomes were recorded. The patients were divided into 2 groups in terms of anatomical success. In group A, all patients had intact grafts without perforation, retraction, or lateralization, and a dry ear, at 6 months postoperatively. In group B, reperforation of the tympanic membrane was evident 6 months postoperatively. The average ETa and ETl values of each group were measured on computed tomography images using a multiplanar reconstruction technique, and compared. The ETa values of diseased ears of males and females were, respectively, 26.60 ± 6.42° and 23.29 ± 6.51°, compared to 27.25 ± 5.23° and 23.32 ± 4.61° for normal male and female ears, respectively. In group A, the ETa was 26.46 ± 6.82° in males and 22.95 ± 7.50° in females. In group B, the ETa was 26.85 ± 6.12° in males and 23.90 ± 4.45° in females. In group A, the mean ETl was 41.0 mm (29.6-45.3 mm) in males and 37.9 mm (32.0-44.5 mm) in females. In group B, the mean ETl was 40.5 mm (30.5-47.1 mm) in males and 38.0 mm (32.8-45.0 mm) in females. In group A, the ETa value of diseased ears did not differ between females and males, but in normal ears, the ETa was higher in males than females (P = 0.020 and P  0.05). No difference in the ETl values of diseased and normal ears, in either group, was apparent between females and males (both P > 0.05). Neither the ETa nor the ETl affected the success rate of pediatric cartilage type 1 tympanoplasty. Further studies with larger numbers of patients are needed to compare anatomical outcomes

  9. Retrospective results of radiation therapy of the Eustachian tube in chronic otitis media; Retrospektive Ergebnisse der perkutanen Strahlentherapie der Tuba Eustachii bei chronischer Otitis media

    Energy Technology Data Exchange (ETDEWEB)

    Schultze, J.; Reinke, C.; Kimmig, B. [Klinik fuer Strahlentherapie (Radioonkologie), Universitaetsklinikum Kiel (Germany); Frese, K.A. [Klinik fuer Hals-, Nasen- und Ohrenheilkunde, Kopf- und Halschirurgie, Universitaetsklinikum Kiel (Germany)


    Background: The treatment results of symptomatic radiation therapy of the Eustachian tube in chronic otitis media had to be evaluated retrospectively. Patients and Methods: Between 1980 and 1997, 66 patients were referred for therapy. The median age was 58 years. In the clinical presentation, all the patients had a hearing impairment, 35 patients complained of pain, 21 had otorrhea. In their history, 20 patients indicated chronic recurrent infections. The complaints lasted for 4.7 years in the median, primary conservative (adstringentia, antibiotics) and surgical treatment (paracentesis, tympanic tubule, tympanoplastic) did not lead to lasting cure. In 40 of 66 patients, finally radiation therapy was done of both Eustachian tubes. With opposed fields and cobalt-60 photons a total dose of 6 Gy at single doses of 1 Gy, three times a week, was applied. Under the causes for exclusion of radiation therapy were non-acceptance of the patients (nine), prior radiation therapies (six) or spontaneous improvement after initial presentation in our department. The treatment results were evaluated by interviews of the patients and regular otorhinolaryngological examinations. Results: There were no side effects noticed. 28 of 40 (70%) patients reported a significant improvement that could be verified by objective otorhinolaryngological examinations. In the group of 26 nonirradiated patients, 22 could be interviewed indicating in 16 cases (72%) that the complaints were unchanged and chronic otitis media was lasting. In a subgroup analysis concerning the duration of otitis media radiation therapy proved more effective in an acute and subacute stadium of disease of up to 5 years duration, while the patients resistant to radiation therapy were entirely in a chronic stage of disease exceeding 5 years duration. (orig.) [German] Hintergrund: Die Behandlungsergebnisse der symptomatischen Radiotherapie bei chronischer Otitis media sollten retrospektiv evaluiert werden. Patienten und

  10. [The Eustachian tube and its role in the history of otology. Images from the history of otorhinolaryngology, presented by instruments from the collection of the Ingolstadt German History Museum]. (United States)

    Feldmann, H


    Even in ancient times the existence of an open pathway between the ear and the respiratory tract was assumed. Up to the middle ages, however, Aristotle's idea that the air in the ear is an innate part of the body prevailed. The first anatomical description of the tube was given by Eustachius (1563). He still adhered to the concept of "innate air" and regarded the tube only as a pathway for draining pathological matter from the tympanic cavity. Duverney (1683) realized that an important function of the tube was replacing and adjusting the pressure of the air in the tympanic cavity. He thought that the tube is permanently open, thus offering a vent to the air, when the tympanic membrane is moving inwards and outwards. Valsalva (1704) discovered a muscle for opening the tube, and he presumed that in hearing this muscle would come into action. He described the maneuver that is named after him as a method to expel pus from the tympanic cavity into the external auditory canal. E.G. Guyot, a postmaster in Versailles, was the first to try catheterization of his own Eustachian tube via the mouth. Cleland (1741) inserted the catheter via the nose, and Wathen (1756) after studies on corpses described in detail the technique how to carry out this procedure. The therapeutic application of Eustachian catheterization as practiced by physicians such as Itard (1821) centered around irrigation with water and medications as well as inflation of various fumes. Deleau (1836) later advocated a douche of pure air and, in analogy to the auscultation of the lung, described the different noises that could be perceived during this procedure. Numerous models of pumps were constructed for this air douche, which became one of the most widely used therapeutical means in otology. There were also lethal incidents caused by cutaneous emphysemata. Toynbee realized that at rest the tube is closed and that there is a constant absorption of air in the tympanic cavity. The tube would be opened only by

  11. Ear Tubes (United States)

    ... of the ear drum or eustachian tube, Down Syndrome, cleft palate, and barotrauma (injury to the middle ear caused by a reduction of air pressure, ... specialist) may be warranted if you or your child has experienced repeated ... fluid in the middle ear, barotrauma, or have an anatomic abnormality that ...

  12. Measurement of middle ear pressure changes during balloon eustachian tuboplasty: a pilot study. (United States)

    Todt, Ingo; Abdel-Aziz, Tarek; Mittmann, Philipp; Lehmann, Martin; Ebmeyer, Jörg; Scholtz, Lars-Uwe; Sudhoff, Holger


    The middle ear pressure changes detected during BET can be directly attributed to the balloon inflation and may represent a second, immediate, mechanism of action of BET. BET seems to be safe with respect to the risk of a barotrauma. Further human studies are now necessary to confirm the results and gain more insight into the mechanism of action of BET. Since the introduction of Balloon Eustachian Tuboplasty (BET) as a treatment of chronic Eustachian tube dysfunction, the precise mechanism of action is unknown. Long-term effects of BET may be related to observed microfractures of the Eustachian tube cartilage. However, clinical observations indicate a second, immediate mode of action. Therefore, this study investigated and characterized middle ear pressure changes occurring directly during BET procedure. Using a micro-optical pressure sensor, pressure changes during BET were monitored transtympanically in a cadaveric animal study using heathland sheep. Middle ear pressure amplitudes during BET are dependent on the speed of balloon inflation as well as the maximum inflation pressure. A 10-bar inflation pressure yielded a mean middle ear pressure of 5.34 mmHg (71.0 daPA). Negative pressure amplitudes occurring on withdrawal of the balloon catheter are influenced by the speed of withdrawal. No pressure amplitudes capable of causing barotrauma to membranous ear structures could be detected.

  13. Late health effects of radiation for eustachian tube dysfunction : a non-concurrent prospective study

    NARCIS (Netherlands)

    P.G. Verduijn


    textabstractThe present study is a non-concurrent prospective cohort study on the risks of the Crowe therapy in 2,542 subjects who underwent this treatment compared to 2,380 - similar - non-irradiated control subjects. The study population consisted of patients from five Dutch ENT clinics. The

  14. The evaluation of the angles of Eustachian tubes in the patients with ...

    African Journals Online (AJOL)

    Introduction: Chronic otitis media (COM), affecting all over the world and in a wide range of age groups in Turkey, is an important cause of ear discharge and hearing loss. The main clinical manifestations are tympanic membrane perforation, ear, nose and throat problems. On the tympanic membrane perforation becomes ...

  15. [Long-term follow-up after tympanostomy tube insertion in children with serous otitis media]. (United States)

    Fekete-Szabó, Gabriella; Kiss, Fekete; Rovó, László


    The authors report about the efficacy of inserted tympanostomy tube in children with serous otitis media. The aim of the authors was to assess the status of eardrum, the function of Eustachian tube and hearing level 10 years after the use of tympanostomy tube. Patients filled out a questionnaire and microscopic examination of tympanic membrane, tympanometry, Eustachian tube function examination, and audiometry tests were performed. In the period of 2003-2004, ventilation tube insertion was performed in 711 patients in the ENT Department of Pediatric Health Center of University of Szeged. In 349 patients adenotomy and tympanostomy tube insertion, in 18 cases tonsillectomy and grommet insertion and in 344 patients only typmanostomy tube insertion were performed. Due to objective difficulties (address change, no phone number) 453 patients were asked for control test and 312 persons accepted the invitation. Normal hearing level was found in 84.6% of patients and normal tympanometry result occurred in 82%. Tympanic ventilation disorder, perforation of tympanic membrane, sensorineural hearing loss and sensorineural hearing loss due to noise exposure were diagnosed. Application of tympanostomy tube is effective in the treatment of serous otitis media resulting from ventilation disorder. The authors draw attention to the importance of tympanometry examination to prevent the adhesive processes and cholesteatoma in chronic ventilation disorder of the middle ear.

  16. Heterogeneity of glycoconjugates in the secretory cells of the chinchilla middle ear and eustachian tubal epithelia: a lectin-gold cytochemical study. (United States)

    Ueno, K; Lim, D J


    The present study was conducted to characterize and localize the glycoconjugates in the tubotympanum (auditory or eustachian tube and middle ear cavity) of chinchilla on an ultrastructural level, using lectin-gold complexes with six different lectins: BPA, ConA, RCA-1, WGA, LFA, and SNA. A comparison of the affinity of these lectins demonstrated the heterogeneity of secretory cells. The glandular serous cells and epithelial dark granulated cells produced "serum"-type glycoprotein. The glandular mucous cells and goblet cells produced dominantly "mucin"-type glycoprotein in the light granules, but "serum"-type glycoprotein in the dark cores. The labeling of LFA and SNA showed that sialic acids existed mainly in the mucinous granules of secretory cells and ciliated epithelium glycocalyx, and in the mucous blanket. The results also suggested that the dominant linkage of sialic acids of mucin is a Neu5Ac(alpha 2-6)Gal/GalNAc sequence. Furthermore, the data obtained from ConA and BPA suggested that initial O-glycosylation of mucin took place in the cis side of the Golgi apparatus and that initial N-glycosylation of the serum occurred in the rough endoplasmic reticulum.

  17. Severe Persistant Cyanosis in a Newborn Due to Prominent Eustachian Valve

    Directory of Open Access Journals (Sweden)

    Vehbi Doğan


    Full Text Available ABSTRACTThe valves of right horn of systemic venous sinus are prominent structures within the right atrium during early embryonic period. Involution of these structures may not be complete, resulting in a spectrum of anatomical presentations such as cyanosis. A full-term male neonate referred to our hospital for precise evaluation of severe cyanosis on the first day of life. Echocardiographic examination revealed right-to-left interatrial shunting through patent foramen ovale due to prominent eustachian valve with normal estimated right heart pressures from peak tricuspid regurgitation velocity. He was maintained with supplemental oxygen and a PDE-5 inhibitor (sildenafil and subsequently improvement in oxygen saturation was achieved. The patient was discharged after 2 weeks of treatment. In conclusion; the embryologic remmants of the sinus venosus rarely may lead to right-to-left shunting resulting in severe cyanosis. Pulmonary vasodilators such as sildenafil may improve oxygen saturation in these patients even in case of normal right heart pressures.

  18. TUBE TESTER (United States)

    Gittings, H.T. Jr.; Kalbach, J.F.


    This patent relates to tube testing, and in particular describes a tube tester for automatic testing of a number of vacuum tubes while in service and as frequently as may be desired. In it broadest aspects the tube tester compares a particular tube with a standard tube tarough a difference amplifier. An unbalanced condition in the circuit of the latter produced by excessive deviation of the tube in its characteristics from standard actuates a switch mechanism stopping the testing cycle and indicating the defective tube.

  19. Feeding Tubes (United States)

    ... feeding therapies have been exhausted. Please review product brand and method of placement carefully with your physician ... Total Parenteral Nutrition. Resources: Oley Foundation Feeding Tube Awareness Foundation Children’s Medical Nutrition Alliance APFED’s Educational Webinar ...

  20. Neutron tubes (United States)

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani


    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  1. photomultiplier tube

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  2. photomultiplier tubes

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  3. Neural Tube Defects (United States)

    ... vitamin, before and during pregnancy prevents most neural tube defects. Neural tube defects are usually diagnosed before the infant is ... or imaging tests. There is no cure for neural tube defects. The nerve damage and loss of function ...

  4. Nasogastric feeding tube (United States)

    ... of what to do. What to Expect at Home If your child has an NG tube, try to keep your child from touching or pulling on the tube. After your nurse teaches you how to flush the tube and perform skin care around the nose, set up a daily routine for these tasks. Flushing the Tube Flushing the ...

  5. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: ...

  6. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia ...

  7. NEI You Tube Videos: Amblyopia (United States)

    ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia ...

  8. Pulse Tube Refrigerator (United States)

    Matsubara, Yoichi

    The pulse tube refrigerator is one of the regenerative cycle refrigerators such as Stirling cycle or Gifford-McMahon cycle which gives the cooling temperature below 150 K down to liquid helium temperature. In 1963, W. E. Gifford invented a simple refrigeration cycle which is composed of compressor, regenerator and simple tube named as pulse tube which gives a similar function of the expander in Stirling or Gifford-McMahon cycle. The thermodynamically performance of this pulse tube refrigerator is inferior to that of other regenerative cycles. In 1984, however, Mikulin and coworkers made a significant advance in pulse tube configuration called as orifice pulse tube. After this, several modifications of the pulse tube hot end configuration have been developed. With those modifications, the thermodynamic performance of the pulse tube refrigerator became the same order to that of Stirling and Gifford-McMahon refrigerator. This article reviews the brief history of the pulse tube refrigerator development in the view point of its thermodynamically efficiency. Simplified theories of the energy flow in the pulse tube have also been described.

  9. Categorising YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo


    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube......’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition...... and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within...

  10. Retrograde Gastrojejunostomy Tube Migration

    Directory of Open Access Journals (Sweden)

    Adeleke Adesina


    Full Text Available Percutaneous enteral feeding tubes are placed about 250,000 times each year in the United States. Although they are relatively safe, their placement may be complicated by perforation, infection, bleeding, vomiting, dislodgment, and obstruction. There have been numerous reports of antegrade migration of gastrojejunostomy (G-J tubes. We report a case of G-J tube regurgitation following protracted vomiting and discuss the management of this very rare entity.

  11. Heated Tube Facility (United States)

    Federal Laboratory Consortium — The Heated Tube Facility at NASA GRC investigates cooling issues by simulating conditions characteristic of rocket engine thrust chambers and high speed airbreathing...

  12. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.


    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  13. Pyrotechnic Tubing Connector (United States)

    Graves, Thomas J.; Yang, Robert A.


    Tool forms mechanical seal at joint without levers or hydraulic apparatus. Proposed tool intended for use in outer space used on Earth by heavily garbed workers to join tubing in difficult environments. Called Pyrotool, used with Lokring (or equivalent) fittings. Piston slides in cylinder when pushed by gas from detonating pyrotechnic charge. Impulse of piston compresses fittings, sealing around butting ends of tubes.

  14. Neural Tube Defects (United States)

    ... pregnancies each year in the United States. A baby’s neural tube normally develops into the brain and spinal cord. ... fluid in the brain. This is called hydrocephalus. Babies with this condition are treated with surgery to insert a tube (called a shunt) into the brain. The shunt ...

  15. Molybdenum Tube Characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Beaux II, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    Chemical vapor deposition (CVD) techniques have been utilized to produce free-standing molybdenum tubes with the end goal of nuclear fuel clad applications. In order to produce tubes with properties desirable for this application, deposition rates were lowered requiring long deposition durations on the order of 50 hours. Standard CVD methods as well as fluidized-bed CVD (FBCVD) methods were applied towards these objectives. Characterization of the tubes produced in this manner revealed material suitable for fuel clad applications, but lacking necessary uniformity across the length of the tubes. The production of freestanding Mo tubes that possess the desired properties across their entire length represents an engineering challenge that can be overcome in a next iteration of the deposition system.

  16. Isolated Fallopian Tube Torsion

    Directory of Open Access Journals (Sweden)

    S. Kardakis


    Full Text Available Isolated torsion of the Fallopian tube is a rare gynecological cause of acute lower abdominal pain, and diagnosis is difficult. There are no pathognomonic symptoms; clinical, imaging, or laboratory findings. A preoperative ultrasound showing tubular adnexal masses of heterogeneous echogenicity with cystic component is often present. Diagnosis can rarely be made before operation, and laparoscopy is necessary to establish the diagnosis. Unfortunately, surgery often is performed too late for tube conservation. Isolated Fallopian tube torsion should be suspected in case of acute pelvic pain, and prompt intervention is necessary.

  17. Tracheostomy tube - eating (United States)

    Trach - eating ... take your first bites. Certain factors may make eating or swallowing harder, such as: Changes in the ... easier to swallow. Suction the tracheostomy tube before eating. This will keep you from coughing while eating, ...

  18. Bull Moose Tube Company (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against the Bull Moose Tube Company, a business located at 1819 Clarkson Road, Chesterfield, MO, 63017, for alleged violations at the facility located at 406 East Industrial Drive,

  19. Tube-Forming Assays. (United States)

    Brown, Ryan M; Meah, Christopher J; Heath, Victoria L; Styles, Iain B; Bicknell, Roy


    Angiogenesis involves the generation of new blood vessels from the existing vasculature and is dependent on many growth factors and signaling events. In vivo angiogenesis is dynamic and complex, meaning assays are commonly utilized to explore specific targets for research into this area. Tube-forming assays offer an excellent overview of the molecular processes in angiogenesis. The Matrigel tube forming assay is a simple-to-implement but powerful tool for identifying biomolecules involved in angiogenesis. A detailed experimental protocol on the implementation of the assay is described in conjunction with an in-depth review of methods that can be applied to the analysis of the tube formation. In addition, an ImageJ plug-in is presented which allows automatic quantification of tube images reducing analysis times while removing user bias and subjectivity.

  20. Tube Alinement for Machining (United States)

    Garcia, J.


    Tool with stepped shoulders alines tubes for machining in preparation for welding. Alinement with machine tool axis accurate to within 5 mils (0.13mm) and completed much faster than visual setup by machinist.

  1. Power vacuum tubes handbook

    CERN Document Server

    Whitaker, Jerry


    Providing examples of applications, Power Vacuum Tubes Handbook, Third Edition examines the underlying technology of each type of power vacuum tube device in common use today. The author presents basic principles, reports on new development efforts, and discusses implementation and maintenance considerations. Supporting mathematical equations and extensive technical illustrations and schematic diagrams help readers understand the material. Translate Principles into Specific Applications This one-stop reference is a hands-on guide for engineering personnel involved in the design, specification,

  2. Aeronautical tubes and pipes (United States)

    Beauclair, N.


    The main and subcomponent French suppliers of aircraft tubes and pipes are discussed, and the state of the industry is analyzed. Quality control is essential for tubes with regard to their i.d. and metallurgical compositions. French regulations do not allow welded seam tubes in hydraulic circuits unless no other form is available, and then rustproofed steel must be installed. The actual low level of orders for any run of tubes dictates that the product is only one of several among the manufacturers' line. Automation, both in NDT and quality control, assures that the tubes meet specifications. A total of 10 French companies participate in the industry, serving both civil and military needs, with some companies specializing only in titanium, steel, or aluminum materials. Concerns wishing to enter the market must upgrade their equipment to meet the higher aeronautical specifications and be prepared to furnish tubes and pipes that serve both functional and structural purposes simultaneously. Additionally, pipe-bending machines must also perform to tight specifications. Pipes can range from 0.2 mm exterior diameter to 40 mm, with wall thicknesses from 0.02 mm to 3 mm. A chart containing a list of manufacturers and their respective specifications and characteristics is presented, and a downtrend in production with reduction of personnel is noted.

  3. Spherical tube hypersurfaces

    CERN Document Server

    Isaev, Alexander


    We examine Levi non-degenerate tube hypersurfaces in complex linear space which are "spherical," that is, locally CR-equivalent to the real hyperquadric. Spherical hypersurfaces are characterized by the condition of the vanishing of the CR-curvature form, so such hypersurfaces are flat from the CR-geometric viewpoint. On the other hand, such hypersurfaces are also of interest from the point of view of affine geometry. Thus our treatment of spherical tube hypersurfaces in this book is two-fold: CR-geometric and affine-geometric. As the book shows, spherical tube hypersurfaces possess remarkable properties. For example, every such hypersurface is real-analytic and extends to a closed real-analytic spherical tube hypersurface in complex space. One of our main goals is to provide an explicit affine classification of closed spherical tube hypersurfaces whenever possible. In this book we offer a comprehensive exposition of the theory of spherical tube hypersurfaces, starting with the idea proposed in the pioneering...

  4. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... search for current job openings visit HHS USAJobs Home > NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract ...

  5. Gastrostomy feeding tube - pump - child (United States)

    ... tube feeding; PEG tube care; Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Gather supplies: Feeding pump (electronic or battery powered) Feeding ... pump (includes a feeding bag, drip chamber, roller clamp, ...

  6. Categorising YouTube

    Directory of Open Access Journals (Sweden)

    Thomas Mosebo Simonsen


    Full Text Available This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC of YouTube. The article investigates the construction of navigationprocesses on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within the interacting relationship of new and old genres are discussed. It is argued that the utility of a conventional categorical system is primarily of analytical and theoretical interest rather than as a practical instrument.

  7. Geiger-Muller tubes

    Energy Technology Data Exchange (ETDEWEB)

    Gair, S.A.; Copleston, R.E.


    A Geiger-Muller tube designed for use in an environment (for example, mounted on a rock drill) where subjected to mechanical shock and vibration has a tensioned anode wire secured by welding to securement members between first and second mounts at opposite ends of the tube envelope. The wire tension is adjusted to a high value with a screwable-adjustment means which is locked eg. by a spot-weld or by a locking nut, in the adjusted position, so that the natural frequency of the vibration of the tensioned wire does not resonate with (and may be much higher than) the frequencies to which the tube is subjected in use. The wire frequency is typically in excess of 400Hz and even 500Hz. The adjustment means may be included in the mount via which the envelope is evacuated and back-filled with the ionizible gas, and a gas-tight seal can be provided around this part of the mount, for example by sealing off the gas pump tube. However the adjustment means may be designed into another part of the tube, for example using telescopic parts of the envelope whose sliding junction is made gas tight with a flexible seal. (author).

  8. A New Resonance Tube (United States)

    Bates, Alan


    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at…

  9. Cladding tube manufacturing technology

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, R. [Kraftwerk Union AG, Mulheim (Germany); Jeong, Y.H.; Baek, B.J.; Kim, K.H.; Kim, S.J.; Choi, B.K.; Kim, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)


    This report gives an overview of the manufacturing routine of PWR cladding tubes. The routine essentially consists of a series of deformation and annealing processes which are necessary to transform the ingot geometry to tube dimensions. By changing shape, microstructure and structure-related properties are altered simultaneously. First, a short overview of the basics of that part of deformation geometry is given which is related to tube reducing operations. Then those processes of the manufacturing routine which change the microstructure are depicted, and the influence of certain process parameters on microstructure and material properties are shown. The influence of the resulting microstructure on material properties is not discussed in detail, since it is described in my previous report 'Alloy Development for High Burnup Cladding.' Because of their paramount importance still up to now, and because manufacturing data and their influence on properties for other alloys are not so well established or published, the descriptions are mostly related to Zry4 tube manufacturing, and are only in short for other alloys. (author). 9 refs., 46 figs.

  10. Jejunostomy feeding tube (United States)

    ... skin for redness, odor, pain, puss, or swelling. Make sure the stitches are still in place. Use the clean towel or Q-tip to clean the skin around the J-tube 1 to 3 times a day with mild soap and water. Try to remove any drainage or crusting on ...

  11. Drift tubes of Linac 2

    CERN Multimedia

    Photographic Service


    Being redied for installation, those at the right are for tank 1, those on the left for tank 2. Contrary to Linac 1, which had drift-tubes supported on stems, here the tubes are suspended, for better mechanical stability.

  12. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence Insufficiency Diabetic Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma ...

  13. Enteral Tube Feeding and Pneumonia (United States)

    Gray, David Sheridan; Kimmel, David


    To determine the effects of enteral tube feeding on the incidence of pneumonia, we performed a retrospective review of all clients at our institution who had gastrostomy or jejunostomy tubes placed over a 10-year period. Ninety-three subjects had a history of pneumonia before feeding tube insertion. Eighty had gastrostomy and 13, jejunostomy…

  14. Vortex tube optimization theory

    Energy Technology Data Exchange (ETDEWEB)

    Lewins, Jeffery [Cambridge Univ., Magdalene Coll., Cambridge (United Kingdom); Bejan, Adrian [Duke Univ., Dept. of Mechanical Engineering and Materials Science, Durham, NC (United States)


    The Ranque-Hilsch vortex tube splits a single high pressure stream of gas into cold and warm streams. Simple models for the vortex tube combined with regenerative precooling are given from which an optimisation can be undertaken. Two such optimisations are needed: the first shows that at any given cut or fraction of the cold stream, the best refrigerative load, allowing for the temperature lift, is nearly half the maximum loading that would result in no lift. The second optimisation shows that the optimum cut is an equal division of the vortex streams between hot and cold. Bounds are obtainable within this theory for the performance of the system for a given gas and pressure ratio. (Author)

  15. YouTube Physics (United States)

    Riendeau, Diane


    To date, this column has presented videos to show in class, Don Mathieson from Tulsa Community College suggested that YouTube could be used in another fashion. In Don's experience, his students are not always prepared for the mathematic rigor of his course. Even at the high school level, math can be a barrier for physics students. Walid Shihabi, a colleague of Don's, decided to compile a list of YouTube videos that his students could watch to relearn basic mathematics. I thought this sounded like a fantastic idea and a great service to the students. Walid graciously agreed to share his list and I have reproduced a large portion of it below.

  16. Neural tube defects

    Directory of Open Access Journals (Sweden)

    M.E. Marshall


    Full Text Available Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have been used to describe this defect, but spina bifida remains the most useful general term, as it describes the separation of the vertebral elements in the midline.

  17. Diffusion in Tube Dialyzer

    Directory of Open Access Journals (Sweden)

    Yohannes Nigatie


    Full Text Available Nowadays, kidney failure is a problem of many peoples in the world. We know that the main function of kidney is maintaining the chemical quality of blood particularly removing urea through urine. But when they malfunction, the pathologic state known as uremia results in a condition in which the urea is retained in the body. Failure of the kidney results in building up of harmful wastes and excess fluids in the body. Kidney diseases (failures can be due to infections, high blood pressure (hypertension, diabetes, and/or extensive use of medication. The best form of treatment is the implantation of a healthy kidney from a donor. However, this is often not possible due to the limited availability of human organs. Chronic kidney failure requires the treatment using a tube dialyzer called dialysis. Blood is taken out of the body and passes through a special membrane that removes waste and extra fluids. The clean blood is then returned to the body. The process is controlled by a dialysis machine (tube dialyzer which is equipped with a blood pump and monitoring systems to ensure safety. So this article investigates the real application of mathematics (diffusion in medical science, and it also contains the mathematical formulation and interpretation of tube dialyzer in relation to diffusion.

  18. Reliability of steam generator tubing

    Energy Technology Data Exchange (ETDEWEB)

    Kadokami, E. [Mitsubishi Heavy Industries Ltd., Hyogo-ku (Japan)


    The author presents results on studies made of the reliability of steam generator (SG) tubing. The basis for this work is that in Japan the issue of defects in SG tubing is addressed by the approach that any detected defect should be repaired, either by plugging the tube or sleeving it. However, this leaves open the issue that there is a detection limit in practice, and what is the effect of nondetectable cracks on the performance of tubing. These studies were commissioned to look at the safety issues involved in degraded SG tubing. The program has looked at a number of different issues. First was an assessment of the penetration and opening behavior of tube flaws due to internal pressure in the tubing. They have studied: penetration behavior of the tube flaws; primary water leakage from through-wall flaws; opening behavior of through-wall flaws. In addition they have looked at the question of the reliability of tubing with flaws during normal plant operation. Also there have been studies done on the consequences of tube rupture accidents on the integrity of neighboring tubes.

  19. Steam generator tube integrity program

    Energy Technology Data Exchange (ETDEWEB)

    Dierks, D.R.; Shack, W.J. [Argonne National Laboratory, IL (United States); Muscara, J.


    A new research program on steam generator tubing degradation is being sponsored by the U.S. Nuclear Regulatory Commission (NRC) at Argonne National Laboratory. This program is intended to support a performance-based steam generator tube integrity rule. Critical areas addressed by the program include evaluation of the processes used for the in-service inspection of steam generator tubes and recommendations for improving the reliability and accuracy of inspections; validation and improvement of correlations for evaluating integrity and leakage of degraded steam generator tubes, and validation and improvement of correlations and models for predicting degradation in steam generator tubes as aging occurs. The studies will focus on mill-annealed Alloy 600 tubing, however, tests will also be performed on replacement materials such as thermally-treated Alloy 600 or 690. An overview of the technical work planned for the program is given.

  20. Diffusion in a Curved Tube


    Ogawa, Naohisa


    The diffusion of particles in confining walls forming a tube is discussed. Such a transport phenomenon is observed in biological cells and porous media. We consider the case in which the tube is winding with curvature and torsion, and the thickness of the tube is sufficiently small compared with its curvature radius. We discuss how geomerical quantities appear in a quasi-one-dimensional diffusion equation.

  1. Alternate tube plugging criteria for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Cueto-Felgueroso, C.; Aparicio, C.B. [Tecnatom, S.A., Madrid (Spain)


    The tubing of the Steam Generators constitutes more than half of the reactor coolant pressure boundary. Specific requirements governing the maintenance of steam generator tubes integrity are set in Plant Technical Specifications and in Section XI of the ASME Boiler and Pressure Vessel Code. The operating experience of Steam Generator tubes of PWR plants has shown the existence of some types of degradatory processes. Every one of these has an specific cause and affects one or more zones of the tubes. In the case of Spanish Power Plants, and depending on the particular Plant considered, they should be mentioned the Primary Water Stress Corrosion Cracking (PWSCC) at the roll transition zone (RTZ), the Outside Diameter Stress Corrosion Cracking (ODSCC) at the Tube Support Plate (TSP) intersections and the fretting with the Anti-Vibration Bars (AVBs) or with the Support Plates in the preheater zone. The In-Service Inspections by Eddy Currents constitutes the standard method for assuring the SG tubes integrity and they permit the monitoring of the defects during the service life of the plant. When the degradation reaches a determined limit, called the plugging limit, the SG tube must be either repaired or retired from service by plugging. Customarily, the plugging limit is related to the depth of the defect. Such depth is typically 40% of the wall thickness of the tube and is applicable to any type of defect in the tube. In its origin, that limit was established for tubes thinned by wastage, which was the predominant degradation in the seventies. The application of this criterion for axial crack-like defects, as, for instance, those due to PWSCC in the roll transition zone, has lead to an excessive and unnecessary number of tubes being plugged. This has lead to the development of defect specific plugging criteria. Examples of the application of such criteria are discussed in the article.

  2. YouTube and 'psychiatry'. (United States)

    Gordon, Robert; Miller, John; Collins, Noel


    YouTube is a video-sharing website that is increasingly used to share and disseminate health-related information, particularly among younger people. There are reports that social media sites, such as YouTube, are being used to communicate an anti-psychiatry message but this has never been confirmed in any published analysis of YouTube clip content. This descriptive study revealed that the representation of 'psychiatry' during summer 2012 was predominantly negative. A subsequent smaller re-analysis suggests that the negative portrayal of 'psychiatry' on YouTube is a stable phenomenon. The significance of this and how it could be addressed are discussed.

  3. Bacterial Biofilms in Jones Tubes. (United States)

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  4. Learning from YouTube [Video Book (United States)

    Juhasz, Alexandra


    YouTube is a mess. YouTube is for amateurs. YouTube dissolves the real. YouTube is host to inconceivable combos. YouTube is best for corporate-made community. YouTube is badly baked. These are a few of the things Media Studies professor Alexandra Juhasz (and her class) learned about YouTube when she set out to investigate what actually happens…

  5. Infrared imaging of LED lighting tubes and fluorescent tubes (United States)

    Siikanen, Sami; Kivi, Sini; Kauppinen, Timo; Juuti, Mikko


    The low energy efficiency of conventional light sources is mainly caused by generation of waste heat. We used infrared (IR) imaging in order to monitor the heating of both LED tube luminaires and ordinary T8 fluorescent tubes. The IR images showed clearly how the surface temperatures of the fluorescent tube ends quickly rose up to about +50...+70°C, whereas the highest surface temperatures seen on the LED tubes were only about +30...+40°C. The IR images demonstrated how the heat produced by the individual LED chips can be efficiently guided to the supporting structure in order to keep the LED emitters cool and hence maintain efficient operation. The consumed electrical power and produced illuminance were also recorded during 24 hour measurements. In order to assess the total luminous efficacy of the luminaires, separate luminous flux measurements were made in a large integrating sphere. The currently available LED tubes showed efficacies of up to 88 lm/W, whereas a standard "cool white" T8 fluorescent tube produced ca. 75 lm/W. Both lamp types gave ca. 110 - 130 lx right below the ceiling-mounted luminaire, but the LED tubes consume only 40 - 55% of the electric power compared to fluorescent tubes.

  6. Drop tube technical tasks (United States)

    Workman, G. L.


    Criteria, using fundamental thermochemical dynamics, were developed to assist a scientist using the Drop Tube Facility in designing a good experiment. The types of parameters involved in designing the experiments include the type of furnace, the type of atmosphere, and in general which materials are better behaved than others as determined by past experience in the facility. One of the major advantages of the facility lies in its ability to provide large undercoolings in the cooling curve during the drops. A beginning was to consider the effect of oxygen and other gases upon the amount of undercooling observed. The starting point of the thermochemistry was given by Ellingham and later transformed into what is known as the Richardson Chart. The effect of surface oxidations upon the nucleation phenomena can be observed in each specimen.

  7. Nasoenteric tube complications. (United States)

    Prabhakaran, S; Doraiswamy, V A; Nagaraja, V; Cipolla, J; Ofurum, U; Evans, D C; Lindsey, D E; Seamon, M J; Kavuturu, S; Gerlach, A T; Jaik, N P; Eiferman, D S; Papadimos, T J; Adolph, M D; Cook, C H; Stawicki, S P A


    The use of nasoenteric tubes (NETs) is ubiquitous, and clinicians often take their placement, function, and maintenance for granted. NETs are used for gastrointestinal decompression, enteral feeding, medication administration, naso-biliary drainage, and specialized indications such as upper gastrointestinal bleeding. Morbidity associated with NETs is common, but frequently subtle, mandating high index of suspicion, clinical vigilance, and patient safety protocols. Common complications include sinusitis, sore throat and epistaxis. More serious complications include luminal perforation, pulmonary injury, aspiration, and intracranial placement. Frequent monitoring and continual re-review of the indications for continued use of any NET is prudent, including consideration of changing goals of care. This manuscript reviews NET-related complications and associated topics.

  8. Piezoelectric Rotary Tube Motor (United States)

    Fisher, Charles D.; Badescu, Mircea; Braun, David F.; Culhane, Robert


    A custom rotary SQUIGGLE(Registered TradeMark) motor has been developed that sets new benchmarks for small motor size, high position resolution, and high torque without gear reduction. Its capabilities cannot be achieved with conventional electromagnetic motors. It consists of piezoelectric plates mounted on a square flexible tube. The plates are actuated via voltage waveforms 90 out of phase at the resonant frequency of the device to create rotary motion. The motors were incorporated into a two-axis postioner that was designed for fiber-fed spectroscopy for ground-based and space-based projects. The positioner enables large-scale celestial object surveys to take place in a practical amount of time.

  9. Flaming on YouTube

    NARCIS (Netherlands)

    Moor, Peter J.; Heuvelman, A.; Verleur, R.


    In this explorative study, flaming on YouTube was studied using surveys of YouTube users. Flaming is defined as displaying hostility by insulting, swearing or using otherwise offensive language. Three general conclusions were drawn. First, although many users said that they themselves do not flame,

  10. Enteral tube feeding in adults. (United States)

    Scott, R; Bowling, T E


    Enteral tube feeding is usually a relatively straightforward method of nutritional support, and should be facilitated by a multiprofessional team. For short-term use (tube is indicated but if longer term feeding is required then a gastrostomy is appropriate, usually inserted endoscopically (a percutaneous endoscopic gastrostomy tube). The most common serious complication of a nasogastric tube is not identifying a misplaced tube within the lungs: there are clear recommendations from the National Patient Safety Agency as to how to check tube placement. Nasojejunal tubes are required in patients with gastroparesis. Tube blockage is common and is prevented by careful and regular flushing. Diarrhoea is the most complication of feeding and is often related to other medication. Clinicians need an algorithm for systematically dealing with such a problem. Refeeding syndrome may occur in malnourished patients and is characterised by low levels of potassium, phosphate, and/or magnesium, as well as disorders of water and salt balance. Identifying the at-risk patient with careful monitoring is crucial.

  11. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia NEI Home Contact Us A-Z Site Map NEI on Social Media Information in Spanish (Información en español) Website, ...

  12. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... National Eye Institute’s mission is to “conduct and support research, training, health information dissemination, and other programs ... search for current job openings visit HHS USAJobs Home > NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI ...

  13. 27 CFR 40.352 - Cigarette tubes. (United States)


    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette tubes...

  14. Drug administration via nasogastric tube. (United States)

    Clarke, Sonya


    In 2005, the National Patient Safety Agency (NPSA) highlighted concerns about the management of nasogastric tubes following reports of unnecessary deaths because of misplaced feeding tubes in infants, children and adults. During 2006, I investigated the management of nasogastric tubes (NGTs) in children (Clarke and Richardson 2007a, 2007b). This systematic review divided primary papers into three principal themes: enteral feeding via the NGT; confirmation of NGT position and associated incidence of tube placement error; and hydration via the NGT for acute gastroenteritis in children. Findings of the review are summarised here in relation to using the nasogastric tube to administer medication to children with the aim of informing practice and improving safety.

  15. Eddy current signal comparison for tube identification (United States)

    Glass, S. W.; Vojvodic, R.


    Inspection of nuclear power plant steam generator tubes is required to justify continued safe plant operation. The steam generators consist of thousands of tubes with nominal diameters of 15 to 22mm, approximately 1mm wall thickness, and 20 to 30m in length. The tubes are inspected by passing an eddy current probe through the tubes from tube end to tube end. It is critical to know exactly which tube identification (row and column) is associated with each tube's data. This is controlled by a precision manipulator that provides the tube ID to the eddy current system. Historically there have been some instances where the manipulator incorrectly reported the tube ID. This can have serious consequences including lack of inspection of a tube, or if a pluggable indication is detected, the tube is likely to be mis-plugged thereby risking a primary to secondary leak.

  16. Water-storage-tube systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hemker, P.


    Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

  17. Flux tubes at finite temperature

    Energy Technology Data Exchange (ETDEWEB)

    Cea, Paolo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Dipartimento di Fisica dell’Università di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cosmai, Leonardo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cuteri, Francesca; Papa, Alessandro [Dipartimento di Fisica, Università della Calabria & INFN-Cosenza,Ponte Bucci, cubo 31C, I-87036 Rende (Cosenza) (Italy)


    The chromoelectric field generated by a static quark-antiquark pair, with its peculiar tube-like shape, can be nicely described, at zero temperature, within the dual superconductor scenario for the QCD confining vacuum. In this work we investigate, by lattice Monte Carlo simulations of the SU(3) pure gauge theory, the fate of chromoelectric flux tubes across the deconfinement transition. We find that, if the distance between the static sources is kept fixed at about 0.76 fm ≃1.6/√σ and the temperature is increased towards and above the deconfinement temperature T{sub c}, the amplitude of the field inside the flux tube gets smaller, while the shape of the flux tube does not vary appreciably across deconfinement. This scenario with flux-tube “evaporation” above T{sub c} has no correspondence in ordinary (type-II) superconductivity, where instead the transition to the phase with normal conductivity is characterized by a divergent fattening of flux tubes as the transition temperature is approached from below. We present also some evidence about the existence of flux-tube structures in the magnetic sector of the theory in the deconfined phase.

  18. Method of making straight fuel cell tubes (United States)

    Borglum, Brian P.


    A method and an apparatus for making straight fuel cell tubes are disclosed. Extruded tubes comprising powders of fuel cell material and a solvent are dried by rotating the extruded tubes. The rotation process provides uniform circumferential drying which results in uniform linear shrinkage of the tubes. The resultant dried tubes are very straight, thereby eliminating subsequent straightening steps required with conventional processes. The method is particularly useful for forming inner air electrode tubes of solid oxide fuel cells.

  19. PEG tubes: dealing with complications. (United States)

    Malhi, Hardip; Thompson, Rosie

    A percutaneous endoscopic gastronomy tube can be used to deliver nutrition, hydration and medicines directly into the patient's stomach. Patients will require a tube if they are unable to swallow safely, putting them at risk of aspiration of food, drink and medicines into their lungs. It is vital that nurses are aware of the complications that may arise when caring for a patient with a PEG tube. It is equally important that nurses know how to deal with these complications or from where tc seek advice. This article provides a quick troubleshooting guide to help nurses deal with complications that can arise with PEG feeding.

  20. Glass Tube Design for CRT(Cathode Ray Tube)


    Junko, ITOH; Keizo, KISHIDA; Koji, NAKAMURA; Masayuki, Miyazaki; Shigeo, OHSUGI; Sumio, YOSHIOKA; Department of Precision Science & Technology, Osaka University; Mitsubishi Elec.Corp.


    Stress and deformation of cathode ray tubes(CRTs)under atmospheric pressure and implosion protection band tightening were analyzed using a finite element method(FEM). The stress and deformation of the tubes were measured experimentally by using strain gages and three-dimensional position measuring techniques. The experimental results showed close agreements with those of the simulation. The location of the highest tensile stress and the effects of tightening of the implosion protection bands ...

  1. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Grants and Funding Extramural Research Division of Extramural Science Programs Division of Extramural Activities Extramural Contacts NEI ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded ...

  2. Epidemiology of neural tube defects

    National Research Council Canada - National Science Library

    Seidahmed, Mohammed Z; Abdelbasit, Omar B; Shaheed, Meeralebbae M; Alhussein, Khalid A; Miqdad, Abeer M; Khalil, Mohamed I; Al-Enazy, Naif M; Salih, Mustafa A


    To find the prevalence of neural tube defects (NTDs), and compare the findings with local and international data, and highlight the important role of folic acid supplementation and flour fortification with folic acid in preventing NTDs...

  3. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Intern Program Diversity In Vision Research & Ophthalmology (DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home > NEI YouTube Videos > ...

  4. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... questions Clinical Studies Publications Catalog Photos and Images Spanish Language Information Grants and Funding Extramural Research Division ... Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video ...

  5. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... and Aging Program African American Program Training and Jobs Fellowships NEI Summer Intern Program Diversity In Vision ... DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home > NEI YouTube Videos > ...

  6. Examination of gavage tube placement in children. (United States)

    Ellett, M L; Beckstrand, J


    A primary issue in ensuring safe and effective enteral feeding by tube is achieving and maintaining correct tube position. This study was conducted to determine the prevalence of tube placement errors, risk factors associated with these errors, and accuracy of commonly used bedside placement-screening methods. In this descriptive study, 39 hospitalized children having one or more types of enteral tubes were studied prospectively. Tube placement was assessed across time, using three common placement-screening methods compared to radiographs. Tube placement error occurred in 43.5% of tubes at least once during the observation period. Children who were comatose or semicomatose, were inactive, had swallowing problems, or had Argyle tubes were more likely to have tube placement errors. Findings suggest that radiographs to document tube placement may be needed, at least on initial enteral tube insertion.

  7. Dermatology on YouTube. (United States)

    Boyers, Lindsay N; Quest, Tyler; Karimkhani, Chante; Connett, Jessica; Dellavalle, Robert P


    YouTube, reaches upwards of six billion users on a monthly basis and is a unique source of information distribution and communication. Although the influence of YouTube on personal health decision-making is well established, this study assessed the type of content and viewership on a broad scope of dermatology related content on YouTube. Select terms (i.e. dermatology, sun protection, skin cancer, skin cancer awareness, and skin conditions) were searched on YouTube. Overall, the results included 100 videos with over 47 million viewers. Advocacy was the most prevalent content type at 24% of the total search results. These 100 videos were "shared" a total of 101,173 times and have driven 6,325 subscriptions to distinct YouTube user pages. Of the total videos, 35% were uploaded by or featured an MD/DO/PhD in dermatology or other specialty/field, 2% FNP/PA, 1% RN, and 62% other. As one of the most trafficked global sites on the Internet, YouTube is a valuable resource for dermatologists, physicians in other specialties, and the general public to share their dermatology-related content and gain subscribers. However, challenges of accessing and determining evidence-based data remain an issue.

  8. Determination of eustachius tube ventilation functioning among benign type chronic suppurative otitis media and non-otitis media subjects using sonotubometry (United States)

    Ikhwan, M.; Hafil, A. F.; Bramanthyo, B.


    The Eustachian tube (ET) is responsible for the ventilation, protection, and cleaning of the middle ear. ET dysfunction plays an important role in the pathogenesis of otitis media cases, and thus the treatment and prognosis of these cases is extremely dependent on adequate ET function, which can ultimately affect the success rate of middle ear reconstruction practices. Data research on the ET’s ventilation function is needed to ensure the success of therapy and surgery treatments in the case of Chronic Suppurative Otitis Media (CSOM) patients. This study aims to investigate ET ventilation functioning in benign type CSOM and non-otitis media subjects and to develop another modality to measure ET ventilation functioning in patients with intact and perforated tympanic membranes. A comparative cross-sectional study of 36 benign type CSOM patients and 80 non-otitis media subjects will be conducted using sonotubometry and the rated parameter measurements of ET opening frequency, amplitude and ET opening duration. Malfunctioning ventilation of the ET is more common among benign type CSOM subjects (47%) than among non-otitis media subjects (18.75%). There is a significant difference (p = 0.002) between the ET ventilation functioning of benign type CSOM subjects and non-otitis media subjects—benign type CSOM subjects have rates of malfunctioning ET ventilation that are 3.88 times higher than those of non-otitis media subjects. Patients with benign type CSOM are more likely to experience malfunctioning ET ventilation than are non-otitis media subjects.

  9. ATLAS muon drift tube production in Seattle

    CERN Document Server

    Zhao, T; Kuykendall, W; Davisson, R


    The drift tube production facility that we developed for producing precision drift tubes of the ATLAS forward muon system in our laboratory is described in this paper. The results of quality assurance for approximately 30,000 tube produced are given. Our experience shows that this production facility is very efficient and the quality of produced drift tubes is very high. (2 refs).

  10. 27 CFR 41.35 - Cigarette tubes. (United States)


    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 41.35... OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Taxes Tax Rates § 41.35 Cigarette tubes. Cigarette tubes are taxed at the following rates...

  11. 21 CFR 872.6570 - Impression tube. (United States)


    ... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6570 Impression tube. (a) Identification. An impression tube is a device consisting of a hollow copper tube intended to take an impression of a single tooth... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Impression tube. 872.6570 Section 872.6570 Food...

  12. Physics of magnetic flux tubes

    CERN Document Server

    Ryutova, Margarita


    This book is the first account of the physics of magnetic flux tubes from their fundamental properties to collective phenomena in an ensembles of flux tubes. The physics of magnetic flux tubes is absolutely vital for understanding fundamental physical processes in the solar atmosphere shaped and governed by magnetic fields. High-resolution and high cadence observations from recent space and  ground-based instruments taken simultaneously at different heights and temperatures not only show the ubiquity of filamentary structure formation but also allow to study how various events are interconnected by system of magnetic flux tubes. The book covers both theory and observations. Theoretical models presented in analytical and phenomenological forms are tailored for practical applications. These are welded with state-of-the-art observations from early decisive ones to the most recent data that open a new phase-space for exploring the Sun and sun-like stars. Concept of magnetic flux tubes is central to various magn...

  13. Tubing and cable cutting tool (United States)

    Mcsmith, D. D.; Richardson, J. I. (Inventor)


    A hand held hydraulic cutting tool was developed which is particularly useful in deactivating ejection seats in military aircraft rescue operations. The tool consists primarily of a hydraulic system composed of a fluid reservoir, a pumping piston, and an actuator piston. Mechanical cutting jaws are attached to the actuator piston rod. The hydraulic system is controlled by a pump handle. As the pump handle is operated the actuator piston rod is forced outward and thus the cutting jaws are forced together. The frame of the device is a flexible metal tubing which permits easy positioning of the tool cutting jaws in remote and normally inaccessible locations. Bifurcated cutting edges ensure removal of a section of the tubing or cable to thereby reduce the possibility of accidental reactivation of the tubing or cable being severed.

  14. On hydraulics of capillary tubes

    Directory of Open Access Journals (Sweden)

    N.G. Aloyan


    Full Text Available The article considers the laws of motion of water in the capillary tubes, taken as a model for flowing well, on the analogical net count device. For capillary tube the lower limit value of flow rate is empirically determined above which the total hydraulic resistance of the capillary is practically constant. The specificity of the phenomenon is that the regime of motion, by a Reynolds number, for a given flow rate still remains laminar. This circumstance can perplex the specialists, so the author invites them to the scientific debate on the subject of study. Obviously, to identify the resulting puzzle it is necessary to conduct a series of experiments using capillaries of different lengths and diameters and with different values of overpressure. The article states that in tubes with very small diameter the preliminary magnitude of capillary rise of water in the presence of flow plays no role and can be neglected.

  15. Drift tubes of Linac 2

    CERN Multimedia

    CERN PhotoLab


    With the advent of the 800 MeV PS Booster in 1972, the original injector of the PS, a 50 MeV Alvarez-type proton linac, had reached its limits, in terms of intensity and stability. In 1973 one therefore decided to build a new linac (Linac 2), also with a drift-tube Alvarez structure and an energy of 50 MeV. It had a new Cockcroft-Walton preinjector with 750 keV, instead of the previous one with 500 keV. Linac 2 was put into service in 1980. The old Linac 1 was then used for the study of, and later operation with, various types of ions. This picture shows Linac 2 drift-tubes, suspended on stems coming from the top, in contrast to Linac 1, where the drift-tubes stood on stems coming from the bottom.

  16. The pollen tube paradigm revisited. (United States)

    Kroeger, Jens; Geitmann, Anja


    The polar growth process characterizing pollen tube elongation has attracted numerous modeling attempts over the past years. While initial models focused on recreating the correct cellular geometry, recent models are increasingly based on experimentally assessed cellular parameters such as the dynamics of signaling processes and the mechanical properties of the cell wall. Recent modeling attempts have therefore substantially gained in biological relevance and predictive power. Different modeling methods are explained and the power and limitations of individual models are compared. Focus is on several recent models that use closed feedback loops in order to generate limit cycles representing the oscillatory behavior observed in growing tubes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. YouTube and Facebook

    DEFF Research Database (Denmark)

    Robertson, Scott P.; Vatrapu, Ravi; Medina, Richard

    This paper examines the links to YouTube from the Facebook “walls” of Barack Obama, Hillary Clinton, and John McCain over two years prior to the 2008 U.S. Presidential election. User-generated linkage patterns show how participants in these politically-related social networking dialogues used...... online video to make their points. We show a strong integration of the Web 2.0 and new media technologies of social networking and online video. We argue that political discussion in social networking environments can no longer be viewed as primarily textual, and that neither Facebook nor YouTube can...

  18. Working session 3: Tubing integrity

    Energy Technology Data Exchange (ETDEWEB)

    Cueto-Felgueroso, C. [Tecnatom, S.A., San Sebastian de los Reyes, Madrid (Spain); Strosnider, J. [NRC, Washington, DC (United States)


    Twenty-three individuals representing nine countries (Belgium, Canada, the Czech Republic, France, Japan, the Slovak Republic, Spain, the UK, and the US) participated in the session on tube integrity. These individuals represented utilities, vendors, consultants and regulatory authorities. The major subjects discussed by the group included overall objectives of managing steam generator tube degradation, necessary elements of a steam generator degradation management program, the concept of degradation specific management, structural integrity evaluations, leakage evaluations, and specific degradation mechanisms. The group`s discussions on these subjects, including conclusions and recommendations, are summarized in this article.

  19. Orifice plates and venturi tubes

    CERN Document Server

    Reader-Harris, Michael


    This book gives the background to differential-pressure flow measurement and goes through the requirements explaining the reason for them. For those who want to use an orifice plate or a Venturi tube the standard ISO 5167 and its associated Technical Reports give the instructions required.  However, they rarely tell the users why they should follow certain instructions.  This book helps users of the ISO standards for orifice plates and Venturi tubes to understand the reasons why the standards are as they are, to apply them effectively, and to understand the consequences of deviations from the standards.

  20. Biocompatibility of Different Nerve Tubes

    Directory of Open Access Journals (Sweden)

    Hisham Fansa


    Full Text Available Bridging nerve gaps with suitable grafts is a major clinical problem. The autologous nerve graft is considered to be the gold standard, providing the best functional results; however, donor site morbidity is still a major disadvantage. Various attempts have been made to overcome the problems of autologous nerve grafts with artificial nerve tubes, which are “ready-to-use” in almost every situation. A wide range of materials have been used in animal models but only few have been applied to date clinically, where biocompatibility is an inevitable prerequisite. This review gives an idea about artificial nerve tubes with special focus on their biocompatibility in animals and humans.

  1. Pump element for a tube pump

    DEFF Research Database (Denmark)


    The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...... pump as mentioned above, thereby acting to generate a fluid flow through the tube upon repeated deformation of the tube between the two valve members. The pump element may comprise a connecting part for coupling to another tube and may comprise a sealing part establishing a fluid tight connection...

  2. Thermal inhomogeneities in vortex tubes (United States)

    Lemesh, N. I.; Senchuk, L. A.

    An experimental study of the effect of the temperature of the inlet gas on the temperature difference between the hot and cold streams discharged from a Ranque-Hilsch vortex tube is described. The experimental results are presented in graphical form. It is that the temperature difference increases with the temperature of the entering gas.

  3. Working session 1: Tubing degradation

    Energy Technology Data Exchange (ETDEWEB)

    Kharshafdjian, G. [Atomic Energy of Canada, Mississauga, Ontario (Canada); Turluer, G. [IPSN, Fontenay-aux-Roses (France)


    A general introductory overview of the purpose of the group and the general subject area of SG tubing degradation was given by the facilitator. The purpose of the session was described as to {open_quotes}develop conclusions and proposals on regulatory and technical needs required to deal with the issues of SG tubing degradation.{close_quotes} Types, locations and characteristics of tubing degradation in steam generators were briefly reviewed. The well-known synergistic effects of materials, environment, and stress and strain/strain rate, subsequently referred to by the acronym {open_quotes}MESS{close_quotes} by some of the group members, were noted. The element of time (i.e., evolution of these variables with time) was emphasized. It was also suggested that the group might want to consider the related topics of inspection capabilities, operational variables, degradation remedies, and validity of test data, and some background information in these areas was provided. The presentation given by Peter Millet during the Plenary Session was reviewed; Specifically, the chemical aspects and the degradation from the secondary side of the steam generator were noted. The main issues discussed during the October 1995 EPRI meeting on secondary side corrosion were reported, and a listing of the potential SG tube degradations was provided and discussed.

  4. Kundt's Tube Experiment Using Smartphones (United States)

    Parolin, Sara Orsola; Pezzi, Giovanni


    This article deals with a modern version of Kundt's tube experiment. Using economic instruments and a couple of smartphones, it is possible to "see" nodes and antinodes of standing acoustic waves in a column of vibrating air and to measure the speed of sound.

  5. Vitamins and neural tube defects


    Harris, Rodney


    The use of vitamin supplements by women around the time of conception was examined and compared in those having babies with neural tube defects, those with still births or some other type of malformation, and in women who had normal babies.

  6. OurTube / David Talbot

    Index Scriptorium Estoniae

    Talbot, David


    USA California Ülikooli töötajate Abram Stern'i ja Michael Dale'i poolt 2005. a. algatatud USA kongressis peetud kõnede videoremiksidest ja nende poolt loodud veebisaidist Ka YouTube keskkonnast ja wikipedia katsetustest muuta oma keskkond multimeedialisemaks

  7. Fin-tube solar collectors (United States)


    Report presents test procedures and results of thermal-performance evaluation of seven commercial fin tube (liquid) solar collector-absorber plates. Tests were conducted indoors at Marshall Space Flight Center Solar simulator. Results are graphically shown along with supporting test data and summary, indicating efficiency as function of collector inlet temperature.

  8. Tube Suction Test for Evaluating (United States)


    In a comprehensive laboratory study, different tests namely, unconfined compressive strength (UCS) at the end of freeze-thaw/wet-dry (F-T/W-D) cycles, resilient modulus (Mr) at the end of F-T/W-D cycles, vacuum saturation, tube suction, and moisture ...

  9. Building your own shock tube

    NARCIS (Netherlands)

    J. Naber (Jorick)


    textabstractThis report treats the development of a shock tube solver for the simulation of flows described by the one-dimensional Euler equations. A well-known one-dimensional flow problem is the initial Riemann problem, which treats the development of a flow due to two initially separated

  10. Welding the CNGS decay tube

    CERN Multimedia

    Maximilien Brice


    3.6 km of welds were required for the 1 km long CERN Neutrinos to Gran Sasso (CNGS) decay tube, in which particles produced in the collision with a proton and a graphite target will decay into muons and muon neutrinos. Four highly skilled welders performed this delicate task.

  11. Schizophrenia on YouTube. (United States)

    Nour, Matthew M; Nour, Murraih H; Tsatalou, Olga-Maria; Barrera, Alvaro


    YouTube ( ) is the most popular video-sharing Web site on the Internet and is used by medical students as a source of information regarding mental health conditions, including schizophrenia. The accuracy and educational utility of schizophrenia presentations on YouTube are unknown. The purpose of this study was to analyze the accuracy of depictions of psychosis in the context of a diagnosis of schizophrenia (referred to in this article as "acute schizophrenia") on YouTube and to assess the utility of these videos as educational tools for teaching medical students to recognize the clinical features of acute schizophrenia. YouTube was searched for videos purporting to show acute schizophrenia. Eligible videos were independently rated by two consultant psychiatrists on two separate occasions 22 days apart for diagnostic accuracy, psychopathology, and educational utility. Videos (N=4,200) were assessed against predefined inclusion and exclusion criteria. The majority were not eligible for further analysis, mostly because they did not claim to show a patient with schizophrenia (74%) or contained duplicated content (11%). Of 35 videos that met the eligibility and adequacy criteria, only 12 accurately depicted acute schizophrenia. Accurate videos were characterized by persecutory delusions (83%), inappropriate affect (75%), and negative symptoms (83%). Despite the fact that 83% of accurate videos were deemed to have good educational utility compared with 15% of inaccurate videos, accurate and inaccurate videos had similar view counts (290,048 versus 186,124). Schizophrenia presentations on YouTube offer a distorted picture of the condition.

  12. A case of a 'lost' nasogastric tube. (United States)

    Sankar, V; Shakeel, M; Keh, S; Ah-See, K W


    To present the case of a 'lost' nasogastric tube and to highlight the importance of imaging and/or chest X-ray after nasogastric tube insertion, especially in unreliable patients. A 50-year-old man, undergoing radiotherapy treatment for squamous cell carcinoma of the tongue base, was admitted for pain control and nasogastric tube feeding. This patient required multiple nasogastric tubes over a two-week period. The patient repeatedly denied pulling the nasogastric tube out and we were unable to establish the exact mode of nasogastric tube removal. On one such occasion another tube was inserted and a check X-ray showed two feeding tubes; the latest one was lying in the left main bronchus and the old nasogastric tube was observed in the oesophagus, with its upper end jutting above the hypopharynx. It was apparent that the patient had somehow cut the tube and swallowed it. This case not only illustrates the importance of flexible nasendoscopy and/or chest X-ray for checking the position of the nasogastric tube, but also highlights that some patients are not tolerant of nasogastric tubes. The use of nasogastric tubes should be avoided in these patients to prevent any self-inflicted injury.

  13. Small bore ceramic laser tube inspection light table (United States)

    Updike, Earl O.


    Apparatus for inspecting small bore ceramic laser tubes, which includes a support base with one or more support rollers. A fluorescent light tube is inserted within the laser tube and the laser tube is supported by the support rollers so that a gap is maintained between the laser tube and the fluorescent tube to enable rotation of the laser tube. In operation, the ceramic tube is illuminated from the inside by the fluorescent tube to facilitate visual inspection. Centering the tube around the axial light of the fluorescent tube provides information about straightness and wall thickness of the laser tube itself.

  14. The accessory fallopian tube: A rare anomaly

    Directory of Open Access Journals (Sweden)

    Kusum R Gandhi


    Full Text Available This paper presents a rare anatomical variation in the form of accessory fallopian tube on right side. The duplication of fallopian tube was observed in a 34-year-old female during routine undergraduate dissection in our department. Fallopian tube is the part of uterus that carries the ovum from the ovary to the uterus. Accessory fallopian tube is the congenital anomaly attached to the ampullary part of main tube. This accessory tube is common site of pyosalpinx, hydrosalpinx, cystic swelling and torsion. The ovum released by the ovary may also be captured by the blind accessory tube leading to infertility or ectopic pregnancy. Hence, all patients of infertility or pelvic inflammatory disease should be screened to rule out the presence of accessory fallopian tube and if encountered should be removed.

  15. Models for Automated Tube Performance Calculations

    Energy Technology Data Exchange (ETDEWEB)

    C. Brunkhorst


    High power radio-frequency systems, as typically used in fusion research devices, utilize vacuum tubes. Evaluation of vacuum tube performance involves data taken from tube operating curves. The acquisition of data from such graphical sources is a tedious process. A simple modeling method is presented that will provide values of tube currents for a given set of element voltages. These models may be used as subroutines in iterative solutions of amplifier operating conditions for a specific loading impedance.

  16. Insta-Head: An Instant Headgear Tube

    Directory of Open Access Journals (Sweden)

    Rajesh B Kuril


    Full Text Available Specialized headgear tubes are required for fabrication of appliances, such as activator-headgear and twin-block with headgear. The common problems with these tubes are that they need to be purchased beforehand and they are expensive. The present article describes the chairside fabrication of a simple, inexpensive headgear tube (insta-head without the need of any specialized armamentarium.

  17. A Novel Mediastinal Drainage Tube for Mediastinitis

    Directory of Open Access Journals (Sweden)

    Jun Ho Yhang


    Full Text Available Mediastinitis is a life-threatening disease, and effective drainage is needed to treat mediastinitis with abscess formation. We recommend an alternative drainage method using chest tube binding with a Silastic Penrose drainage tube. The use of a Silastic Penrose drainage tube may help to manage mediastinitis with abscess formation. This method facilitates effective draining and prevents tissue adhesion.

  18. Studies of Degraded Smelt Spout Opening Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, James R [ORNL; Kish, Joseph R. [Paprican; Willoughby, Adam W [ORNL; Longmire, Hu Foster [ORNL; Singbeil, Douglas [Paprican


    Co-extruded type 304L stainless steel/SA210 carbon steel tubes have been used on the floors and lower walls of many black liquor recovery boilers to address the wall thinning problem that had been an issue for boiler owners and operators. Use of these tubes greatly reduced the corrosion issue, but corrosion was still sometimes observed and cracking was discovered in some tubes, particularly those that are bent to form the openings for smelt spouts. Because cracks in the opening tubes were sometimes observed to extend a significant distance into the tube wall and because these cracks were found fairly frequently, tubes made from a number of alternate cladding materials were tried in place of the 304L clad opening tubes. This paper describes the results of examinations of spout opening tubes of the standard 304L/carbon steel and of several of the alternate materials that have been tried. In addition to the corrosion and cracking seen in the spout opening tubes, another issue associated with these tubes has been observed. Preferential corrosion of the cap welds is sometimes seen on butt welds attaching the spout opening tubes made with alternate cladding materials to the standard 304L/carbon steel co-extruded wall tubes. Some information on the observations of this corrosion is also included in this paper.

  19. Radioactive fallout and neural tube defects

    African Journals Online (AJOL)

    Nejat Akar


    Jul 10, 2015 ... Neural tube defects;. Anencephaly;. Spina bifida. Abstract Possible link between radioactivity and the occurrence of neural tube defects is a long lasting debate ... Neural tube defects, are one of the common congenital mal- formations ... ent cities of Turkey (˙Izmir/Aegean Region; Trabzon/Black Sea region ...

  20. Clinical Burden of Laparoscopic Feeding Jejunostomy Tubes. (United States)

    Speer, Emily A; Chow, Simon C; Dunst, Christy M; Shada, Amber L; Halpin, Valerie; Reavis, Kevin M; Cassera, Maria; Swanström, Lee L


    Feeding jejunostomies (J tubes) provide enteral nutrition when oral and gastric routes are not options. Despite their prevalence, there is a paucity of literature regarding their efficacy and clinical burden. All laparoscopic J tubes placed over a 5-year period were retrospectively reviewed. Clinical burden was measured by number of clinical contact events (tube-related clinic visits, phone calls, ED visits) and morbidity (dislodgement, clogging, tube fracture, infection, other). Tube replacements were also recorded. One hundred fifty-one patients were included. Fifty-nine percent had associated malignancy, and 35 % were placed for nutritional prophylaxis. Mean time to J tube removal was 146 days. J tubes were expected to be temporary in >90 % but only 50 % had sufficient oral intake for removal. Tubes were removed prematurely due to patient intolerance in 8 %. Mortality was 0 %. Morbidity was 51 % and included clogging (12 %), tube fracture (16 %), dislodgement (25 %), infection (18 %) and "other" (leaking, erosion, etc.) in 17 %. The median number of adverse events per J tube was 2(0-8). Mean number of clinic phone calls was 2.5(0-22), ED visits 0.5(0-7), and clinic visits 1.4(0-13), with 82 % requiring more than one J tube-related clinic visit. Unplanned replacements occurred in 40 %. While necessary for some patients, J tubes are associated with high clinical burden.

  1. Roll-forming tubes to header plates (United States)

    Kramer, K.


    Technique has been developed for attaching and sealing tubes to header plates using a unique roll-forming tool. Technique is useful for attaching small tubes which are difficult to roll into conventional grooves in header plate tube holes, and for attaching when welding, brazing, or soldering is not desirable.

  2. The Fuge Tube Diode Array Spectrophotometer (United States)

    Arneson, B. T.; Long, S. R.; Stewart, K. K.; Lagowski, J. J.


    We present the details for adapting a diode array UV-vis spectrophotometer to incorporate the use of polypropylene microcentrifuge tubes--fuge tubes--as cuvettes. Optical data are presented validating that the polyethylene fuge tubes are equivalent to the standard square cross section polystyrene or glass cuvettes generally used in…

  3. Kundt's Tube: An Acoustic Gas Analyzer (United States)

    Aristov, Natasha; Habekost, Gehsa; Habekost, Achim


    A Kundt tube is normally used to measure the speed of sound in gases. Therefore, from known speeds of sound, a Kundt tube can be used to identify gases and their fractions in mixtures. In these experiments, the speed of sound is determined by measuring the frequency of a standing sound wave at a fixed tube length, temperature, and pressure. This…

  4. Spring/dimple instrument tube restraint (United States)

    DeMario, Edmund E.; Lawson, Charles N.


    A nuclear fuel assembly for a pressurized water nuclear reactor has a spring and dimple structure formed in a non-radioactive insert tube placed in the top of a sensor receiving instrumentation tube thimble disposed in the fuel assembly and attached at a top nozzle, a bottom nozzle, and intermediate grids. The instrumentation tube thimble is open at the top, where the sensor or its connection extends through the cooling water for coupling to a sensor signal processor. The spring and dimple insert tube is mounted within the instrumentation tube thimble and extends downwardly adjacent the top. The springs and dimples restrain the sensor and its connections against lateral displacement causing impact with the instrumentation tube thimble due to the strong axial flow of cooling water. The instrumentation tube has a stainless steel outer sleeve and a zirconium alloy inner sleeve below the insert tube adjacent the top. The insert tube is relatively non-radioactivated inconel alloy. The opposed springs and dimples are formed on diametrically opposite inner walls of the insert tube, the springs being formed as spaced axial cuts in the insert tube, with a web of the insert tube between the cuts bowed radially inwardly for forming the spring, and the dimples being formed as radially inward protrusions opposed to the springs.

  5. Numerical and experimental study of an annular pulse tube used in the pulse tube cooler (United States)

    Pang, Xiaomin; Chen, Yanyan; Wang, Xiaotao; Dai, Wei; Luo, Ercang


    Multi-stage pulse tube coolers normally use a U-type configuration. For compactness, it is attractive to build a completely co-axial multi-stage pulse tube cooler. In this way, an annular shape pulse tube is inevitable. Although there are a few reports about previous annular pulse tubes, a detailed study and comparison with a circular pulse tube is lacking. In this paper, a numeric model based on CFD software is carried out to compare the annular pulse tube and circular pulse tube used in a single stage in-line type pulse tube cooler with about 10 W of cooling power at 77 K. The length and cross sectional area of the two pulse tubes are kept the same. Simulation results show that the enthalpy flow in the annular pulse tube is lower by 1.6 W (about 11% of the enthalpy flow) compared to that in circular pulse tube. Flow and temperature distribution characteristics are also analyzed in detail. Experiments are then conducted for comparison with an in-line type pulse tube cooler. With the same acoustic power input, the pulse tube cooler with a circular pulse tube obtains 7.88 W of cooling power at 77 K, while using an annular pulse tube leads to a cooling power of 7.01 W, a decrease of 0.9 W (11.4%) on the cooling performance. The study sets the basis for building a completely co-axial two-stage pulse tube cooler.

  6. ATLS: Catheter and tube placement (United States)

    Gosbee, John; Krupa, Debra T.; Pepper, L.; Orsak, Debra


    The specific objectives of this experiment are: to evaluate the rack mounted equipment and medical supplies necessary for medical procedures; to evaluate the attachments, mounting points, and inner drawer assemblies for the medical supplies; and to evaluate the procedures for performing medical scenarios. The resources available in the HMF miniracks to accomplish medical scenarios and/or procedures include: medical equipment mounted in the racks; a patch panel with places to attach tubing and catheters; self contained drawers full of critical care medical supplies; and an ALS 'backpack' for deploying supplies. The attachment lines, tubing and associated medical supplies will be deployed and used with the equipment and a patient mannequin. Data collection is provided by direct observations by the inflight experimenters, and analysis of still and video photography.

  7. AFRL Ludwieg Tube Initial Performance (United States)


    controls the fill and purge process. A commercial Sylvania 18 kW resistance heater raises the inlet air temperature to 500K prior to filling the...Distribution is unlimited. 3 ms of uniform run conditions between wave passages. The exterior of the driver tube is heated with blanket resistance ...uniformity and noise characteristics, this has not been a major problem with wind tunnels using this type of valve. However, there has been no direct

  8. Tube entrance lens focus control (United States)

    Weisser, D. C.; Fifield, L. K.; Kitchen, T. F. G.; Tunningley, T. B.; Lobanov, N. R.; Muirhead, A. G.


    The entrance of the accelerator tube in a large electrostatic accelerator imposes a strong lens that dominates the beam optics. The magnification of the lens is large because of the low injection energy, the high voltage gradient of the acceleration tube and the long distance to the terminal. In the absence of the acceleration, the magnification would produce an unacceptably large beam spot at the terminal. The tyranny of the lens is especially irksome when the accelerator is required to operate at a lower terminal voltage than the one corresponding to the nominal gradient at high voltage. One way around the difficulty, used in NEC Pelletron accelerators, is to insert a series of nylon and steel rods that short together units of the acceleration structure at the terminal leaving the ones near the entrance close to the nominal gradient for optimum transmission. This operation takes time and risks the loss of insulating gas. Another alternative used in the 25URC at Oak Ridge National Laboratory, is to focus the beam at the tube entrance, substantially diluting the effect of the entrance lens. The beam then diverges and so requires an additional lens part way to the terminal. This solution is only partially effective and still necessitates use of shorting rods for low voltage operation. The fact that these elaborate strategies are used is evidence that the alternative of lowering the injection energy as the terminal voltage is lowered imposes enough problems that it is not used in practice. We have modeled a solution that controls the voltage gradient at the tube entrance using an external power supply. This not only maintains the focusing effect of the lens but provides the opportunity to tune the beam by adjusting the entrance lens. A 150 kV power supply outside the pressure vessel feeds a controllable voltage through a high voltage feed-through to the fifth electrode of the accelerator tube. Thus 150 kV on this electrode creates the nominal gradient of 30 kV per

  9. Gastroenteric tube feeding: Techniques, problems and solutions (United States)

    Blumenstein, Irina; Shastri, Yogesh M; Stein, Jürgen


    Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake, chronic neurological or mechanical dysphagia or gut dysfunction, and patients who are critically ill. However, despite the benefits and widespread use of enteral tube feeding, some patients experience complications. This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding, together with associated complications and special aspects. We conducted an extensive literature search on PubMed, Embase and Medline using index terms relating to enteral access, enteral feeding/nutrition, tube feeding, percutaneous endoscopic gastrostomy/jejunostomy, endoscopic nasoenteric tube, nasogastric tube, and refeeding syndrome. The literature showed common routes of enteral access to include nasoenteral tube, gastrostomy and jejunostomy, while complications fall into four major categories: mechanical, e.g., tube blockage or removal; gastrointestinal, e.g., diarrhea; infectious e.g., aspiration pneumonia, tube site infection; and metabolic, e.g., refeeding syndrome, hyperglycemia. Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route, gastrointestinal complications are without doubt the most common. Complications associated with enteral tube feeding can be reduced by careful observance of guidelines, including those related to food composition, administration rate, portion size, food temperature and patient supervision. PMID:25024606

  10. Development boiling to sprinkled tube bundle

    Directory of Open Access Journals (Sweden)

    Kracík Petr


    Full Text Available This paper presents results of a studied heat transfer coefficient at the surface of a sprinkled tube bundle where boiling occurs. Research in the area of sprinkled exchangers can be divided into two major parts. The first part is research on heat transfer and determination of the heat transfer coefficient at sprinkled tube bundles for various liquids, whether boiling or not. The second part is testing of sprinkle modes for various tube diameters, tube pitches and tube materials and determination of individual modes’ interface. All results published so far for water as the falling film liquid apply to one to three tubes for which the mentioned relations studied are determined in rigid laboratory conditions defined strictly in advance. The sprinkled tubes were not viewed from the operational perspective where there are more tubes and various modes may occur in different parts with various heat transfer values. The article focuses on these processes. The tube is located in a low-pressure chamber where vacuum is generated using an exhauster via ejector. The tube consists of smooth copper tubes of 12 mm diameter placed horizontally one above another.

  11. Comparison of complication rates, types, and average tube patency between jejunostomy tubes and percutaneous gastrostomy tubes in a regional home enteral nutrition support program. (United States)

    Ao, Peter; Sebastianski, Meghan; Selvarajah, Vijeyakumar; Gramlich, Leah


    Percutaneous endoscopic gastrostomy (PEG) tubes are common enteral access devices for long-term enteral nutrition. Jejunostomy tubes (J-tubes) are able to provide postpyloric enteral access in patients who are not PEG tube candidates. There is a scarcity of literature comparing complication rates of J-tubes to PEG tubes. To compare and characterize J-tube and PEG tube complications requiring tube replacement. A retrospective chart review was performed on 560 patients discharged from the Northern Alberta Home Enteral Nutrition Support Program (NAHENSP) from January 2010 to December 2011. Patients were followed for 3 years from initial tube insertion or until discharge from the NAHENSP, whichever was earliest. Comparisons were made in terms of complications requiring tube replacement, tube patency to first replacement, and indications for tube replacement. A total of 64 J-tube patients were identified and compared with 65 PEG tube patients. Tube replacement rates for the J-tube group included 3.2 cases per 1000 patient days compared with 0.86 cases per 1000 patient days in the PEG group (P < .001). The mean ± SEM duration to first tube replacement for J-tube and PEG tube patients was 160 ± 26.3 days and 331 ± 53.6 days, respectively (P = .010). The most common causes for tube replacement in J-tube patients were dislodgement (35.6%) and obstruction (22.2%) compared with routine replacement (54.5%) and dislodgement (27.2%) in the PEG tube group. J-tubes are associated with higher complication rates requiring tube replacement compared with PEG tubes. The main causes of J-tube replacement are dislodgement and obstruction. © 2014 American Society for Parenteral and Enteral Nutrition.

  12. Effect of tube-support interaction on the dynamic responses of heat exchanger tubes. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Y.S.; Jendrzejczyk, J.A.; Wambsganss, M.W.


    Operating heat exchangers have experienced tube damages due to excessive flow-induced vibration. The relatively small inherent tube-to-baffle hole clearances associated with manufacturing tolerances in heat exchangers affect the tube vibrational characteristics. In attempting a theoretical analysis, questions arise as to the effects of tube-baffle impacting on dynamic responses. Experiments were performed to determine the effects of tube-baffle impacting in vertical/horizontal tube orientation, and in air/water medium on the vibrational characteristics (resonant frequencies, mode shapes, and damping) and displacement response amplitudes of a seven-span tube model. The tube and support conditions were prototypic, and overall length approximately one-third that of a straight tube segment of the steam generator designed for the CRBR. The test results were compared with the analytical results based on the multispan beam with ''knife-edge'' supports.

  13. Multi-tube arrangement for combustor and method of making the multi-tube arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Ziminsky, Willy Steve [Simpsonville, SC


    A fuel injector tube includes a one piece, unitary, polygonal tube having an inlet end and an outlet end. The fuel injector tube further includes a fuel passage extending from the inlet end to the outlet end along a longitudinal axis of the polygonal tube, a plurality of air passages extending from the inlet end to the outlet end and surrounding the fuel passage, and a plurality of fuel holes. Each fuel hole connects an air passage with the fuel passage. The inlet end of the polygonal tube is formed into a fuel tube. A fuel injector includes a plurality of fuel injector tubes and a plate. The plurality of fuel tubes are connected to the plate adjacent the inlet ends of the plurality of fuel injector tubes.

  14. Routine jejunostomy tube feeding following esophagectomy (United States)

    van Eden, Hanneke W. J.; Ruurda, Jelle P.; Luyer, Misha D. P.; Steenhagen, Elles; Nieuwenhuijzen, Grard A. P.; van Hillegersberg, Richard


    Background Malnutrition is an important problem following esophagectomy. A surgically placed jejunostomy secures an enteral feeding route, facilitating discharge with home-tube feeding and long-term nutritional support. However, specific complications occur, and data are lacking that support its use over other enteral feeding routes. Therefore routine jejunostomy tube feeding and discharge with home-tube feeding was evaluated, with emphasis on weight loss, length of stay and re-admissions. Methods Consecutive patients undergoing esophagectomy for cancer, with gastric tube reconstruction and jejunostomy creation, were analyzed. Two different regimens were compared. Before January 07, 2011 patients were discharged when oral intake was sufficient, without tube feeding. After that discharge with home-tube feeding was routinely performed. Logistic regression analysis corrected for confounders. Results Some 236 patients were included. The median duration of tube feeding was 35 days. Reoperation for a jejunostomy-related complication was needed in 2%. The median body mass index (BMI) remained stable during tube feeding. The BMI decreased significantly after stopping tube feeding: from 25.6 (1st–3rd quartile 23.0–28.6) kg/m2 to 24.4 (22.0–27.1) kg/m2 at 30 days later [median weight loss: 3.0 (1.0–5.3) kg; 3.9% (1.5–6.3%)]. Weight loss was not affected by the duration of tube feeding duration. Routine home-tube feeding did not affect weight loss, admission time or the readmission rate. Conclusions Weight loss following esophagectomy occurs once that tube feeding is stopped, independently from the time interval after esophagectomy. Moreover routine discharge with home-tube feeding does not reduce length of stay or readmissions. These findings question the value of routine jejunostomy placement and emphasize the need for further research. PMID:28815083

  15. Development of INCONEL 600 precision tube (1)

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Yeong Han; Jo, Bong Hyeon; Lee, Dong Hee; Kim, Wan Kyo; Jeong, Pyeong Keun; Yoon, Hwang Lo; Chio, Seok Sik [Sammi Steel Co. Ltd., Changwon (Korea, Republic of)


    Steam generator, being connected with nuclear fuel reactor is one of the most important part of nuclear power plant and consists of a large number of INCONEL 600 tubes. Approximately 160 tons of tubes are needed for a single nuclear power plant. All of INCONEL 600 steam generator tubes for domestic nuclear power plants have been imported. The aim of this research is to develop INCONEL 600 precision tubes for steam generator of nuclear power plant. If this research is conducted successfully, we can produce nuclear fuel tubes, Ni-alloy precision tubes and stainless steel precision tubes for many purposes and technology of INCONEL 600 steam generator tubes are similar to those of other tubes above mentioned. In the current study, development of preliminary manufacturing process of INCONEL 600 precision tubes for steam generator and investigation of material`s metallurgical characteristics were conducted. The main scope of this research is as follows. First, the preliminary manufacturing process design was conducted after investigations of foreign manufacturing processes and technical reports. Second, the results of investigations of material`s metallurgical characteristics through the manufacturing process were applied to the production technology of tentative INCONEL 600 precision tubes for sample. Third, preliminary process routes were established and samples of INCONEL 600 precision tube were produced by this process. As the results of this research, 14 pieces of INCONEL 600 precision tubes were produced by preliminary manufacturing process and the material`s metallurgical characteristics were investigated through the processes. But the SCC test could not be conducted due to the absence of equipment. In order to apply the results of SCC test to the manufacturing process, we need a SCC tester which can simulate SCC characteristics under high temperature and high pressurized circulating water. 95 refs., 55 figs., 20 tabs.

  16. Cases of fallopian tube prolapse

    Directory of Open Access Journals (Sweden)

    Sushil Chawla


    Full Text Available Fallopian tube prolapse post hysterectomy is rarely reported complication which can lead to doubts in the mind of young and experienced surgeons alike. This leads to patient morbidity and gets different medical treatments ranging from antibiotics to local applications of copper sulphate, without relief. The use of proper surgical technique, prevention of post operative hematoma and infection go a long way in its prevention.We hereby present two cases, which were manged successfully to relieve the patients of their agony.

  17. Comparison of primary jejunostomy tubes versus gastrojejunostomy tubes for percutaneous enteral nutrition. (United States)

    Kim, Charles Y; Engstrom, Bjorn I; Horvath, Jeffrey J; Lungren, Matthew P; Suhocki, Paul V; Smith, Tony P


    To evaluate technical success and long-term outcomes of percutaneous primary jejunostomy tubes for postpyloric enteral feeding compared with percutaneous gastrojejunostomy (GJ) tubes. Over a 25-month interval, 41 consecutive patients (26 male; mean age, 55.9 y) underwent attempted fluoroscopy-guided direct percutaneous jejunostomy tube insertion. Insertions at previous jejunostomy tube sites were excluded. The comparison group consisted of all primary GJ tube insertions performed over a 12-month interval concomitant with the jejunostomy tube interval (N = 169; 105 male; mean age, 59.4 y). Procedural, radiologic, and clinical data were retrospectively reviewed. Intervention rates were expressed as events per 100 catheter-days. The technical success rate for percutaneous jejunostomy tube insertion was 96%, versus 93% for GJ tubes (P = .47). Mean fluoroscopy times were similar for jejunostomy and GJ tubes (9.8 vs 10.0 min, respectively; P value not significant). Jejunostomy tubes exhibited a lower rate of catheter dysfunction than GJ tubes, with catheter exchange rates of 0.24 versus 0.93, respectively, per 100 catheter-days (P = .045). GJ tube tip retraction into the stomach occurred in 9.5% of cases, at a rate of 0.21 per 100 catheter-days. Intervention rates related to leakage were 0.19 and 0.03 for jejunostomy and GJ tubes, respectively (P Jejunostomy and GJ tubes exhibited similar rates of catheter exchange for occlusion and replacement as a result of inadvertent removal. No major complications were encountered in either group. Percutaneous insertion of primary jejunostomy tubes demonstrated technical success and complication rates similar to those of GJ tubes. Jejunostomy tubes exhibited a lower dysfunction rate but a higher leakage rate compared with GJ tubes. Copyright © 2013 SIR. Published by Elsevier Inc. All rights reserved.

  18. Narratives From YouTube

    Directory of Open Access Journals (Sweden)

    Mikael Quennerstedt


    Full Text Available The aim of this paper is to explore what is performed in students’ and teachers’ actions in physical education practice in terms of “didactic irritations,” through an analysis of YouTube clips from 285 PE lessons from 27 different countries. Didactic irritations are occurrences that Rønholt describes as those demanding “didactic, pedagogical reflections and discussions, which in turn could lead to alternative thinking and understanding about teaching and learning.” Drawing on Barad’s ideas of performativity to challenge our habitual anthropocentric analytical gaze when looking at educational visual data, and using narrative construction, we also aim to give meaning to actions, relations, and experiences of the participants in the YouTube clips. To do this, we present juxtaposing narratives from teachers and students in terms of three “didactic irritations”: (a stories from a track, (b, stories from a game, and (c, stories from a bench. The stories re-present events-of-moving in the data offering insights into embodied experiences in PE practice, making students’ as well as teachers’ actions in PE practice understandable.

  19. [Enteral feeding tubes for critically ill patients]. (United States)

    Braun, J; Bein, T; Wiese, C H R; Graf, B M; Zausig, Y A


    The use of enteral feeding tubes is an important part of early enteral feeding in intensive care medicine. In other faculties with non-critically ill patients, such as (oncologic) surgery, neurology, paediatrics or even in palliative care medicine feeding tubes are used under various circumstances as a temporary or definite solution. The advantage of enteral feeding tubes is the almost physiologic administration of nutrition, liquids and medication. Enteral nutrition is thought to be associated with a reduced infection rate, increased mucosal function, improved immunologic function, reduced length of hospital stay and reduced costs. However, the insertion and use of feeding tubes is potentially dangerous and may be associated with life-threatening complications (bleeding, perforation, peritonitis, etc.). Therefore, the following article will give a summary of the different types of enteral feeding tubes and their range of application. Additionally, a critical look on indication and contraindication is given as well as how to insert an enteral feeding tube.

  20. Why do aged fluorescent tubes flicker? (United States)

    Plihon, Nicolas; Ferrand, Jérémy; Guyomar, Tristan; Museur, Flavien; Taberlet, Nicolas


    Our everyday experience of aged and defective fluorescent tubes or bulbs informs us that they may flicker and emit a clicking sound while struggling to light up. In this article, the physical mechanisms controlling the initial illumination of a functioning fluorescent tube are investigated using a simple and affordable experimental setup. Thermionic emission from the electrodes of the tube controls the startup of fluorescent tubes. The origin of the faulty startup of aged fluorescent tubes is discussed and flickering regimes using functional tubes are artificially produced using a dedicated setup that decreases electron emission by the thermionic effect in a controlled manner. The physical parameters controlling the occurrence of flickering light are discussed, and their temporal statistics are reported.


    Directory of Open Access Journals (Sweden)

    Davorin Matanović


    Full Text Available The use of coiled tubing is increasing rapidly with drilling of horizontal wells. To satisfy all requirements (larger mechanical stresses, larger fluid capacities the production of larger sizes and better material qualities was developed. Stresses due to axial forces and pressures that coiled tubing is subjected are close to its performance limits. So it is really important to know and understand the behaviour of coiled tubing to avoid its break, burst or collapse in the well.

  2. Medication administration through enteral feeding tubes. (United States)

    Williams, Nancy Toedter


    An overview of enteral feeding tubes, drug administration techniques, considerations for dosage form selection, common drug interactions with enteral formulas, and methods to minimize tube occlusion is given. Enteral nutrition through a feeding tube is the preferred method of nutrition support in patients who have a functioning gastrointestinal tract but who are unable to be fed orally. This method of delivering nutrition is also commonly used for administering medications when patients cannot swallow safely. However, several issues must be considered with concurrent administration of oral medications and enteral formulas. Incorrect administration methods may result in clogged feeding tubes, decreased drug efficacy, increased adverse effects, or drug-formula incompatibilities. Various enteral feeding tubes are available and are typically classified by site of insertion and location of the distal tip of the feeding tube. Liquid medications, particularly elixirs and suspensions, are preferred for enteral administration; however, these formulations may be hypertonic or contain large amounts of sorbitol, and these properties increase the potential for adverse effects. Before solid dosage forms are administered through the feeding tube, it should be determined if the medications are suitable for manipulation, such as crushing a tablet or opening a capsule. Medications should not be added directly to the enteral formula, and feeding tubes should be properly flushed with water before and after each medication is administered. To minimize drug-nutrient interactions, special considerations should be taken when administering phenytoin, carbamazepine, warfarin, fluoroquinolones, and proton pump inhibitors via feeding tubes. Precautions should be implemented to prevent tube occlusions, and immediate intervention is required when blockages occur. Successful drug delivery through enteral feeding tubes requires consideration of the tube size and placement as well as careful

  3. Unique removal of a kinked nasogastric tube

    Directory of Open Access Journals (Sweden)

    Kumar Shwetanshu Narayan


    Full Text Available Nasogastric (NG tube insertion is a common clinical procedure used for both diagnostic and therapeutic purposes. As the importance of enteral nutrition is being increasingly recognized; the use of NG tube insertion has steadily increased. Here, we present an interesting case in which a kinked NG tube was removed in a unique manner with “push and pull” technique without untoward trauma.

  4. Preparation of nitrogen-doped carbon tubes (United States)

    Chung, Hoon Taek; Zelenay, Piotr


    A method for synthesizing nitrogen-doped carbon tubes involves preparing a solution of cyanamide and a suitable transition metal-containing salt in a solvent, evaporating the solvent to form a solid, and pyrolyzing the solid under an inert atmosphere under conditions suitable for the production of nitrogen-doped carbon tubes from the solid. Pyrolyzing for a shorter period of time followed by rapid cooling resulted in a tubes with a narrower average diameter.

  5. Inverse Kinematics of Concentric Tube Steerable Needles


    Sears, Patrick; Dupont, Pierre E.


    Prior papers have introduced steerable needles composed of precurved concentric tubes. The curvature and extent of these needles can be controlled by the relative rotation and translation of the individual tubes. Under certain assumptions on the geometry and design of these needles, the forward kinematics problem can be solved in closed form by means of algebraic equations. The inverse kinematics problem, however, is not as straightforward owing to the nonlinear map between relative tube disp...

  6. Micro tube heat exchangers for Space Project (United States)

    National Aeronautics and Space Administration — Mezzo fabricates micro tube heat exchangers for a variety of applications, including aerospace, automotive racing, Department of Defense ground vehicles, economizers...

  7. Failure Analysis of a Service Tube (United States)

    Xie, Zhongdong; Cai, Weiguo; Li, Zhenxing; Guan, YiMing; Zhang, Baocheng; Yang, XiaoTong


    One tube was cracked used in the primary reformer furnace in a fertilizer plant for two and half years. In order to find out the causes of cracking, the methods for chemical composition analysis, macro- and microstructure analysis, penetrant testing, weld analysis, crack and surface damage analysis, mechanics property analysis, high temperature endurance performance analysis, stress and wall thickness calculation were adopted. The integrated assessment results showed that the carbon content of the tube was in the lower limit of the standard range; the tube effective wall thickness was too small; local overheating leads to tube cracking in use process.

  8. Enhanced Evaporation and Condensation in Tubes (United States)

    Honda, Hiroshi

    A state-of-the-art review of enhanced evaporation and condensation in horizontal microfin tubes and micro-channels that are used for air-conditioning and refrigeration applications is presented. The review covers the effects of flow pattern and geometrical parameters of the tubes on the heat transfer performance. Attention is paid to the effect of surface tension which leads to enhanced evaporation and condensation in the microfin tubes and micro-channels. A review of prior efforts to develop empirical correlations of the heat transfer coefficient and theoretical models for evaporation and condensation in the horizontal microfin tubes and micro-channels is also presented.

  9. Generation of flux tube waves in stellar convection zones. 1: Longitudinal tube waves (United States)

    Musielak, Z. E.; Rosner, R.; Ulmschneider, P.


    The source functions and the energy fluxes are derived for wave generation in magnetic flux tubes embedded in an otherwise magnetic- field free, turbulent, and compressible fluid. Specific results for the generation of longitudinal tube waves are presented.

  10. Sunspots and the physics of magnetic flux tubes. V - Mutual hydrodynamic forces between neighboring tubes (United States)

    Parker, E. N.


    The mutual hydrodynamic forces between parallel cylinders in a moving fluid are illustrated through several formal examples. Parallel tubes in a uniform flow are attracted or repelled depending on whether they are side by side or one ahead of the other, respectively. A pulsating or undulating tube attracts all other neighboring tubes toward itself. These hydrodynamic effects suggest that the separate flux tubes beneath the sunspots exert significant attractive forces on each other.

  11. Working session 2: Tubing inspection

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, J. [Tecnatom, S.A. San Sebastian de los Reyes, Madrid (Spain); Tapping, R.L. [AECL, Chalk River, Ontario (Canada)


    This session was attended by delegates from 10 countries, and four papers were presented. A wide range of issues was tabled for discussion. Realizing that there was limited time available for more detailed discussion, three topics were chosen for the more detailed discussion: circumferential cracking, performance demonstration (to focus on POD and sizing), and limits of methods. Two other subsessions were organized: one dealt with some challenges related to the robustness of current inspection methods, especially with respect to leaving cracked tubes in service, and the other with developing a chart of current NDE technology with recommendations for future development. These three areas are summarized in turn, along with conclusions and/or recommendations. During the discussions there were four presentations. There were two (Canada, Japan) on eddy current probe developments, both of which addressed multiarray probes that would detect a range of flaws, one (Spain) on circumferential crack detection, and one (JRC, Petten) on the recent PISC III results.

  12. Paramecium swimming in capillary tube

    CERN Document Server

    Jana, Saikat; Jung, Sunghwan


    Swimming organisms in their natural habitat navigate through a wide array of geometries and chemical environments. Interaction with the boundaries is ubiquitous and can significantly modify the swimming characteristics of the organism as observed under ideal conditions. We study the dynamics of ciliary locomotion in Paramecium multimicronucleatum and observe the effect of the solid boundaries on the velocities in the near field of the organism. Experimental observations show that Paramecium executes helical trajectories that slowly transition to straight line motion as the diameter of the capillary tubes decrease. Theoretically this system is modeled as an undulating cylinder with pressure gradient and compared with experiments; showing that such considerations are necessary for modeling finite sized organisms in the restrictive geometries.

  13. Failure analysis of retired steam generator tubings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Pyo; Kim, J. S.; Hwang, S. S. and others


    Degradation of steam generator leads to forced outage and extension of outage, which causes increase in repair cost, cost of purchasing replacement power and radiation exposure of workers. Steam generator tube rupture incident occurred in Uljin 4 in 2002, which made public sensitive to nuclear power plant. To keep nuclear energy as a main energy source, integrity of steam generator should be demonstrated. Quantitative relationship between ECT(eddy current test) signal and crack size is needed in assesment of integrity of steam generator in pressurized water reactor. However, it is not fully established for application in industry. Retired steam generator of Kori 1 has many kinds of crack such as circumferential and axial primary water stress corrosion crack and outer diameter stress corrosion crack(ODSCC). So, it can be used in qualifying and improving ECT technology and in condition monitoring assesment for crack detected in ISI(in service inspection). In addition, examination of pulled tube of Kori 1 retired steam generator will give information about effectiveness of non welded sleeving technology which was employed to repair defect tubes and remedial action which was applied to mitigate ODSCC. In this project, hardware such as semi hot lab. for pulled tube examination and modification transportation cask for pulled tube and software such as procedure of transportation of radioactive steam generator tube and non-destructive and destructive examination of pulled tube were established. Non-destructive and destructive examination of pulled tubes from Kori 1 retired steam generator were performed in semi hot lab. Remedial actions applied to Kori 1 retired steam generator, PWSCC trend and bulk water chemistry and crevice chemistry in Kori 1 were evaluated. Electrochemical decontamination technology for pulled tube was developed to reduce radiation exposure and enhance effectiveness of pulled tube examination. Multiparameter algorithm developed at ANL, USA was

  14. Observation of "YouTube" Language Learning Videos ("YouTube" LLVS) (United States)

    Alhamami, Munassir


    This paper navigates into the "YouTube" website as one of the most usable online tools to learn languages these days. The paper focuses on two issues in creating "YouTube" language learning videos: pedagogy and technology. After observing the existing "YouTube" LLVs, the study presents a novel rubric that is directed…

  15. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons. (United States)


    ... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Washing Boilers § 230.61 Arch tubes, water bar tubes, circulators and thermic siphons. (a) Frequency of cleaning. Each time the boiler is washed, arch tubes and...

  16. Airplane Ear (United States)

    ... an imbalance in the air pressure in the middle ear and air pressure in the environment prevents your eardrum (tympanic membrane) from vibrating as ... eustachian tube. One end is connected to the middle ear. The other end has a ... in the environment changes rapidly, and your eustachian tube often doesn' ...

  17. Broadcast yourself on YouTube - really?

    NARCIS (Netherlands)

    Kruitbosch, G.; Nack, F.


    One essential reason for people to publish on the web is to express themselves freely. YouTube facilitates this self-expression by allowing users to upload video content they generated. This paper investigates to what extent the videos on YouTube are self-generated content, instead of amalgamated

  18. Short Communication Tube-forming polychaetes enhance ...

    African Journals Online (AJOL)

    We collected invertebrate samples from an intertidal flat with low onuphid tube density (2.7 m–2) in Mozambique and document that more organisms (70 times higher mollusc abundances) and more species (15 times more mollusc species) were found associated with solitary tubes of an onuphid polychaete compared with ...

  19. Selecting silicone tubing for device applications. (United States)

    Jahn, D


    A number of factors are involved in selecting the most suitable silicone tubing for a given purpose. These include physical chemistry, performance properties, a supplier's quality system and regulatory compliance. This article provides a guide for device developers when selecting silicone tubing for their applications.

  20. Non-uniform tube representation of proteins

    DEFF Research Database (Denmark)

    Hansen, Mikael Sonne

    might not correctly capture volume exclusion - of crucial importance when trying to understand a proteins $3$d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X...

  1. Non-Uniform Tube Representation of Proteins

    DEFF Research Database (Denmark)

    Hansen, Mikael Sonne

    might not correctly capture volume exclusion - of crucial importance when trying to understand a protein's 3d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X...

  2. Places to Go: YouTube (United States)

    Downes, Stephen


    Founded in 2005 by three former PayPal employees, YouTube has revolutionized the Internet, marking a change from the static Internet to the dynamic Internet. In this edition of Places to Go, Stephen Downes discusses how the rise of a ubiquitous media format--Flash video--has made YouTube's success possible and argues that Flash video has important…

  3. Photomultiplier tubes for Low Level Cerenkov Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Strindehag, O.


    Tube backgrounds of several 2-inch photomultiplier types having S11, 'S' , S13 and S20 cathodes are compared by measuring signal and background pulse height distributions at pulse heights corresponding to a few photo-electrons. The reference signal is generated by means of a {beta}-source and a plexiglass radiator. It is found that comparatively good results are obtained with selected tubes of the EMI types 6097B and 9514B having equivalent dark current dc values down to 10{sup -12} input lumens. Special interest is devoted to the correlation between the measured tube backgrounds and the dark current dc values of the tubes, as a good correlation between these parameters simplifies the selection of photomultiplier tubes. The equivalent dark currents of the tested tubes extend over the range 10{sup -12} to 10{sup -9} input lumens. Although the investigation deals with photomultiplier tubes intended for use in low level Cerenkov detectors it is believed that the results could be valuable in other fields where photomultiplier tubes are utilized for the detection of weak light pulses.

  4. Confined Tube Crimp Using Portable Hand Tools

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Joseph James [Los Alamos National Laboratory; Pereyra, R. A. [LANL Retired; Archuleta, Jeffrey Christopher [Los Alamos National Laboratory; Martinez, Isaac P. [Los Alamos National Laboratory; Nelson, A. M. [MST-16 Summer Student (2007); Allen, Ronald Scott [Los Alamos National Laboratory; Page, R. L. [LANL Retired; Freer, Jerry Eugene [Los Alamos National Laboratory; Dozhier, Nathan Gus [Los Alamos National Laboratory


    The Lawrence Radiation Laboratory developed handheld tools that crimp a 1/16 inch OD tube, forming a leak tight seal1 (see Figure 1). The leak tight seal forms by confining the 1/16 inch OD tubing inside a die while applying crimp pressure. Under confined pressure, the tube walls weld at the crimp. The purpose of this study was to determine conditions for fabricating a leak tight tube weld. The equipment was used on a trial-and-error basis, changing the conditions after each attempt until successful welds were fabricated. To better confine the tube, the die faces were polished. Polishing removed a few thousandths of an inch from the die face, resulting in a tighter grip on the tubing wall. Using detergent in an ultrasonic bath, the tubing was cleaned. Also, the time under crimp pressure was increased to 30 seconds. With these modifications, acceptable cold welds were fabricated. After setting the conditions for an acceptable cold weld, the tube was TIG welded across the crimped face.

  5. Sampling Artifacts from Conductive Silicone Tubing

    Energy Technology Data Exchange (ETDEWEB)

    Timko, Michael T.; Yu, Zhenhong; Kroll, Jesse; Jayne, John T.; Worsnop, Douglas R.; Miake-Lye, Richard C.; Onasch, Timothy B.; Liscinsky, David; Kirchstetter, Thomas W.; Destaillats, Hugo; Holder, Amara L.; Smith, Jared D.; Wilson, Kevin R.


    We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: 1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and 2) silicone tubing emits organic contaminants containing siloxane that adsorb onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and should, therefore, be used with caution. Gentle heating, physical and chemical properties of the particle carriers, exposure to solvents, and tubing age may influence siloxane uptake. The amount of contamination is expected to increase as the tubing surface area increases and as the particle surface area increases. The effect is observed at ambient temperature and enhanced by mild heating (<100 oC). Further evaluation is warranted.

  6. Isolated Fallopian Tube Torsion in Adolescents

    Directory of Open Access Journals (Sweden)

    S. Rajaram


    Full Text Available Background. Fallopian tube torsion is a rare cause of acute abdomen, occurring commonly in females of reproductive age. It lacks pathognomonic symptoms, signs, or imaging features, thus causing delay in surgical intervention. Case. We report two cases of isolated fallopian tube torsion in adolescent girls. In the first case a 19-year-old patient presented with acute pain in the left iliac region associated with episodes of vomiting for one day and mild tenderness on examination. Laparoscopy revealed left sided twisted fallopian tube associated with hemorrhagic cyst of ovary. The tube was untwisted and salvaged. In another case an 18-year-old virgin girl presented with similar complaints since one week, associated with mild tenderness in the lower abdomen and tender cystic mass on per rectal examination. On laparoscopy right twisted fallopian tube associated with a paratubal cyst was found. Salpingectomy was done as the tube was gangrenous. Conclusion. Fallopian tube torsion, though rare, should be considered in women of reproductive age with unilateral pelvic pain. Early diagnostic laparoscopy is important for an accurate diagnosis and could salvage the tube.

  7. A Slot Machine, A Broken Test Tube

    Indian Academy of Sciences (India)

    IAS Admin

    BOOK │ REVIEW. A Slot Machine, A Broken. Test Tube. Vinita Shivakumar and. Dipshikha Chakravortty. A Slot Machine, A Broken Test. Tube – An Autobiography. Salvador Edward Luria. Harper Collins Publishers Inc.,. USA. 1984. 1st edn. 228 pp. (Original from the University of. Michigan). Price: Rs 60/-. Salvador Edward ...

  8. Teaching Shakespeare with YouTube (United States)

    Desmet, Christy


    YouTube, the video sharing website that allows viewers to upload video content ranging from cute dog tricks to rare rock videos, also supports a lively community devoted to the performance of Shakespeare and Shakespearean adaptations. YouTube is also a popular site for student producers of Shakespeare performances, parodies, and other artistic…

  9. Geotextile Tube Structures Guidelines for Contract Specifications (United States)


    Nonwoven fabrics: Diaphragm Bursting Strength Tester Method ASTM D 3884 (1992) Abrasion Resistance of Textile Fabrics (Rotary Platform, Double-Head... filter cloth, excavation of borrow material, transportation of borrow material, filling of the tubes, coating of the completed tubes, disposal of waste

  10. Local Thickening of Stainless Tube Considering Dimension Variation of the Cold Roll Formed Tube Billet (United States)

    Sheu, Jinn-Jong; Yu, Cheng-Hsien


    A stud end consists of tube body and a flange in order to connect two tubes to form a long straight or angled pipe line. The flange is thicker than the tube body to strengthen the pipe connection. A thicker round hollow disk is usually welded to a straight tube to get the flange of the tube end and then machined to the specified dimension of the two-piece type stud end. A one-piece type stud end of tube proposed here is produced via the local thickening of tube end, flaring, and flange forging processes. The roundness of raw tube is not promised in the cold roll forming (CRF) process, which causes the inaccuracy of dimensions, wrinkling, and folding defects during the local thickening process of tube end. In this paper, a preform process was proposed to correct the dimension of the tube to be thickened. The CRF tube billets were measured and preformed to the required dimensions before thickening. The proposed preforming process was able to resize and control the dimensions and roundness of the tube billet to prevent irregular movement of billet. A three-staged punch profile was designed to prevent the folding defect during the thickening process. Experiments of resizing and thickening were carried out to verify the simulation results and the proposed punch profile design. The CAE simulations demonstrated the defects of folding are very sensitive to the dimension variation of tube billet. The experimental results of thickening process were in good agreement with the simulation predictions using the perfect (with preforming process) and the imperfect (original CRF) tube billets. The proposed pre-forming process and the punch profile designs were able to minimize the surface defects of tube local thickening.

  11. Building lab-scale x-ray tube based irradiators (United States)

    The construction of economical x-ray tube based irradiators in a variety of configurations is described using 1000 Watt x-ray tubes. Single tube, double tube, and four tube designs are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small s...

  12. Tubing-for-casing cuts tubular requirements

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, C.W. Jr.


    The tight supply of tubular goods has caused many operators to turn to tubingless completions in field wells devoid of critical downhole problems. It is possible to save up to 50% on tubular steel requirements by this technique. Other than the surface casing, the basic idea employs only one string of pipe of tubing dimensions. Such a completion is illustrated. Tubingless completions generally refer to the use of 2-7/8 in. tubing which is run and cemented as the production casing of a well. In this light, the term tubingless is a misnomer and perhaps tubing-for-casing more aptly described the idea. Tubing-for-casing completions should be considered usually for gas wells where future anticipated remedial work is minimal. However, these completions can be squeezed and normal remedial work can be accomplished with a variety of available tools. Some of the problems that should be investigated when considering a tubing-for-casing are listed and described.

  13. The Mashups of YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo


    This article focuses on YouTube mashups and how we can understand them as a specific subgenre on YouTube. The Mashups are analysed as audiovisual recontextualizations that are given new meaning, e.g., via collaborative social communities or for individual promotional purposes. This is elaborated......, but rather in its social and communicative abilities within the YouTube community. This leads to the article’s overall argument that the main characteristic of the YouTube Mashup can be explained in terms of connectivity. It is argued that Mashups reveal a double articulation of connectivity; one...... that involves the social mechanisms of the Mashups, and another mode, which concerns the explicit embedding of structural connectivity that accentuates the medium-specific infrastructure of YouTube. This double articulation of connectivity is furthermore elaborated on by including Grusin and Bolter’s concept...

  14. Torsional Kinematic Model for Concentric Tube Robots. (United States)

    Dupont, Pierre E; Lock, Jesse; Butler, Evan


    A recent approach to steerable needle design is based on combining pre-curved tubes concentrically. By rotating and extending the tubes with respect to each other, the position and orientation of the needle tip, as well as the shape of the inserted length, can be controlled. Prior models neglected torsional twisting in the curved portions of the tubes. This paper presents a mechanics model that includes torsion, applies to any number of tubes and allows curvature and stiffness to vary with arc length. While the general model is comprised of differential equations, an analytic solution is given for two tubes of constant curvature. This solution enables analytic prediction of "snap through" instability based on a single dimensionless parameter. Simulation and experiments are used to illustrate the results.

  15. Explosion interaction with water in a tube (United States)

    Homae, T.; Sugiyama, Y.; Wakabayashi, K.; Matsumura, T.; Nakayama, Y.


    As proposed and legislated in Japan, subsurface magazines have an explosive storage chamber, a horizontal passageway, and a vertical shaft for a vent. The authors found that a small amount of water on the floor of the storage chamber mitigated blast pressure remarkably. The mitigation mechanism has been examined more closely. To examine the effect of water, the present study assesses explosions in a transparent, square cross section, and a straight tube. A high-speed camera used to observe the tube interior. Blast pressure in and around the tube was also measured. Images obtained using the high-speed camera revealed that water inside the tube did not move after the explosion. Differences between cases of tubes without water and with water were unclear. Along with blast pressure measurements, these study results suggest that blast pressure mitigation by water occurs because of interaction between the explosion and the water near the explosion point.

  16. Atmosphere in a Test Tube (United States)

    Claudi, R.; Pace, E.; Ciaravella, A.; Micela, G.; Piccioni, G.; Billi, D.; Cestelli Guidi, M.; Coccola, L.; Erculiani, M. S.; Fedel, M.; Galletta, G.; Giro, E.; La Rocca, N.; Morosinotto, T.; Poletto, L.; Schierano, D.; Stefani, S.

    The ancestor philosophers' dream of thousand of new world is finally realised: more than 1800 extrasolar planets have been discovered in the neighborhood of our Sun. Most of them are very different from those we used to know in our Solar System. Others orbit the Habitable Zone (HZ) of their parent stars. Space missions, as JWST and the very recently proposed ARIEL, or ground based instruments, like SPHERE@VLT, GPI@GEMINI and EPICS@ELT, have been proposed and built to measure the atmospheric transmission, reflection and emission spectra over a wide wavelength range of these new worlds. In order to interpret the spectra coming out by this new instrumentation, it is important to know in detail the optical characteristics of gases in the typical physical conditions of the planetary atmospheres and how those characteristics could be affected by radiation driven photochemical and bio-chemical reaction. Insights in this direction can be achieved from laboratory studies of simulated planetary atmosphere of different pressure and temperature conditions under the effects of radiation sources, used as proxies of different bands of the stellar emission. ''Atmosphere in a Test Tube'' is a collaboration among several Italian astronomical, biological and engineering institutes in order to share their experiencece in performing laboratory experiments on several items concerning extrasolar planet atmospheres.

  17. Tube Formation in Nanoscale Materials

    Directory of Open Access Journals (Sweden)

    Yan Chenglin


    Full Text Available Abstract The formation of tubular nanostructures normally requires layered, anisotropic, or pseudo-layered crystal structures, while inorganic compounds typically do not possess such structures, inorganic nanotubes thus have been a hot topic in the past decade. In this article, we review recent research activities on nanotubes fabrication and focus on three novel synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. Specifically, thermal oxidation method based on gas–solid reaction to porous CuO nanotubes has been successfully established, semiconductor ZnS and Nb2O5nanotubes have been prepared by employing sacrificial template strategy based on liquid–solid reaction, and an in situ template method has been developed for the preparation of ZnO taper tubes through a chemical etching reaction. We have described the nanotube formation processes and illustrated the detailed key factors during their growth. The proposed mechanisms are presented for nanotube fabrication and the important pioneering studies are discussed on the rational design and fabrication of functional materials with tubular structures. It is the intention of this contribution to provide a brief account of these research activities.

  18. Steam generator tubing NDE performance

    Energy Technology Data Exchange (ETDEWEB)

    Henry, G. [Electric Power Research Institute, Charlotte, NC (United States); Welty, C.S. Jr. [Electric Power Research Institute, Palo Alto, CA (United States)


    Steam generator (SG) non-destructive examination (NDE) is a fundamental element in the broader SG in-service inspection (ISI) process, a cornerstone in the management of PWR steam generators. Based on objective performance measures (tube leak forced outages and SG-related capacity factor loss), ISI performance has shown a continually improving trend over the years. Performance of the NDE element is a function of the fundamental capability of the technique, and the ability of the analysis portion of the process in field implementation of the technique. The technology continues to improve in several areas, e.g. system sensitivity, data collection rates, probe/coil design, and data analysis software. With these improvements comes the attendant requirement for qualification of the technique on the damage form(s) to which it will be applied, and for training and qualification of the data analysis element of the ISI process on the field implementation of the technique. The introduction of data transfer via fiber optic line allows for remote data acquisition and analysis, thus improving the efficiency of analysis for a limited pool of data analysts. This paper provides an overview of the current status of SG NDE, and identifies several important issues to be addressed.

  19. Resonant oscillations in open axisymmetric tubes (United States)

    Amundsen, D. E.; Mortell, M. P.; Seymour, B. R.


    We study the behaviour of the isentropic flow of a gas in both a straight tube of constant cross section and a cone, open at one end and forced at or near resonance at the other. A continuous transition between these configurations is provided through the introduction of a geometric parameter k associated with the opening angle of the cone where the tube corresponds to k=0. The primary objective is to find long-time resonant and near-resonant approximate solutions for the open tube, i.e. k→ 0. Detailed analysis for both the tube and cone in the limit of small forcing (O(ɛ 3)) is carried out, where ɛ 3 is the Mach number of the forcing function and the resulting flow has Mach number O(ɛ ). The resulting approximate solutions are compared with full numerical simulations. Interesting distinctions between the cone and the tube emerge. Depending on the damping and detuning, the responses for the tube are continuous and of O(ɛ ). In the case of the cone, the resonant response involves an amplification of the fundamental resonant mode, usually called the dominant first-mode approximation. However, higher modes must be included for the tube to account for the nonlinear generation of higher-order resonances. Bridging these distinct solution behaviours is a transition layer of O(ɛ 2) in k. It is found that an appropriately truncated set of modes provides the requisite modal approximation, again comparing well to numerical simulations.

  20. Dynamic tube movement of Ahmed glaucoma valve. (United States)

    Law, Simon K; Coleman, Anne L; Caprioli, Joseph


    To report the dynamic movement of the tube of the Ahmed glaucoma valve (AGV) in the anterior chamber with eye movement. Three patients (eyes) with dynamic movement of the tube of the AGV out of approximately 1500 AGV implantations over 10 years were identified. Demographic information, management, and patient outcomes were abstracted from the medical records. Possible mechanisms of the tube movement are discussed. In all 3 eyes, the fibrovascular capsule and the plate were noted to be stationary in the superior temporal fornix under the conjunctiva and did not move with movement of the eye. The length of the intraocular portion of the tube varied between 3 and 4 mm, depending on the position of the globe. All 3 eyes had undergone at least 1 intraocular procedure before AGV implantation and 2 of 3 eyes had at least 1 intraocular procedure after the AGV implantation. The dynamic movement of the tube was first observed from 0.5 to 7 years after the AGVs were implanted. It was not associated with any intraocular reaction, damage of intraocular tissue, or decrease of intraocular pressure control, and no additional surgical intervention has been required. Dynamic movement of the tube of AGV results from dissociation of the fibrovascular capsule and the plate in the fornix from the rotation of the globe. The length of the intraocular portion of the tube may vary widely with eye movement.

  1. Miniature acoustic guidance system for endotracheal tubes (United States)

    Juan, Eduardo J.

    Ensuring that the distal end of an endotracheal tube is properly located within the trachea, and that the tube is not obstructed by mucous deposition, is a major clinical concern in patients that require mechanical ventilation. A novel acoustic system was developed to allow for the continuous monitoring of endotracheal tube position and patency. A miniature sound source and two sensing microphones are placed in-line between the ventilator hose and the proximal end of the endotracheal tube. Reflections of an acoustic pulse from the endotracheal tube lumen and the airways are digitally analyzed to estimate the location and degree of obstruction, as well as the position of the distal end of the tube in the airway. The system was evaluated through computer simulations, in vitro studies, and in a rabbit model. The system noninvasively estimated tube position in vivo to within roughly 4.5 mm, and differentiated between proper tracheal, and erroneous bronchial or esophageal intubation in all cases. In addition, the system estimated the area and location of lumen obstructions in vitro to within 14% and 3.5 mm, respectively. These findings indicate that this miniature technology could improve the quality of care provided to the ventilated adult and infant.

  2. Stroke: Ineffective tube securement reduces nutrition and drug treatment


    Brazier, S.; Taylor, S.J.; Allan, K; R. Clemente; Toher, D.


    Stroke patients with dysphagia often depend on nutrition, hydration and medication via nasogastric (NG) feeding tubes. Securing tubes using tape was associated with repeated tube loss. We determined cause and effect by auditing tube placement methods, delays incurred, duration and costs. Of 202 NG tube placements in 75 patients, 67 placements occurred in 17 patients over a full course of enteral nutrition (EN) and 40 of these placements were tracked. Tubes were secured by tape in 100%, mitten...

  3. Development of inconel alloys precision tube

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Hee; Lee, D. H.; Shin, Y. S.; Park, J. H. [Changwon Speciality Steel Co., Ltd., Changwon (Korea); Kim, J. S.; Kim, H. P; Lim, Y. S.; Hwang, S. S.; Jung, M. K.; Woo, Y. M.; Han, C. H. [Korea Atomic Energy Research Institute, Taejeon (Korea)


    The purpose of this research is to investigate the mass production facility and evaluation of profitability for steam generator tubing in nuclear power plant. The equipment requirement and capacity, total investment cost, the evaluation of mass production yield and production cost accounting, the manufacturing technique standardization have been investigated. According to the result of evaluation of profitability, the project for SG tubing will be difficult to commercialize, but it can be considered the re-commercialize when the condition for investment is improving. The results of this research can be applicated to commercialize the precision tubes manufacturing which require similar process. 17 refs., 7 figs., 21 tabs. (Author)

  4. Noninflammatory fallopian tube pathology in children

    Energy Technology Data Exchange (ETDEWEB)

    Merlini, Laura; Anooshiravani, Mehrak; Hanquinet, Sylviane [University Hospital HUG, Unit of Pediatric Radiology, Geneva (Switzerland); Vunda, Aaron [University Hospital, Clinic of Pediatric Surgery, Geneva (Switzerland); Borzani, Irene; Napolitano, Marcello [Ospedale Buzzi, Pediatric Radiology, Milan (Italy)


    Noninflammatory tubal abnormalities are rare in children and usually not well covered by traditional educational material. The presenting symptoms are nonspecific and are common to many other conditions, so its preoperative diagnosis is rarely made. The purpose of this study was to review the hospital charts and imaging findings in children and sexually inactive adolescents who showed fallopian tube pathology. Understanding of the pertinent findings of previous imaging examinations might assist radiologists in making the correct preoperative diagnosis and increase the likelihood of preserving the fallopian tubes. The clinical entities described in this article include isolated tubal torsion, paratubal cysts, hydrosalpinx, undescended/ectopic fallopian tube, and tubal inguinal hernia. (orig.)

  5. Nervous system examination on YouTube


    Azer Samy A; AlEshaiwi Sarah M; AlGrain Hala A; AlKhelaif Rana A


    Abstract Background Web 2.0 sites such as YouTube have become a useful resource for knowledge and are used by medical students as a learning resource. This study aimed at assessing videos covering the nervous system examination on YouTube. Methods A research of YouTube was conducted from 2 November to 2 December 2011 using the following key words “nervous system examination”, “nervous system clinical examination”, “cranial nerves examination”, “CNS examination”, “examination of cerebellum”, “...

  6. Air Liquide Space Pulse Tube Cryocoolers (United States)

    Tanchon, J.; Trollier, T.; Buquet, J.; Ravex, A.; Crespi, P.


    Thanks to important internal development efforts completed and partial ESA funding, AL/DTA is now in position to propose two Pulse Tube cooler systems in the 40-80K temperature range for coming Earth Observation missions such as MTG, Sentinel 3, etc… The two pulse tube coolers thermo-mechanical units have been qualified against thermal and mechanical environment constraints. To complete these two Pulse Tube coolers, a Cooler Drive Electronic has been developed for active damping and vibration cancellation. The paper presents the current status of these products and associated Cooler Drive Electronics.

  7. Influence of furnace tube shapeon thermal strain of fire-tube boilers

    Directory of Open Access Journals (Sweden)

    Gaćeša Branka


    Full Text Available The aim of this paper is to use numerical analysis and fine element method-FEM to investigate the influence of furnace tube shape on the thermal strain of fire-tube boilers. Thermal stresses in corrugated furnace tubes of different shape, i.e. with different corrugation pitch and depth, were analysed first. It was demonstrated that the thermal stresses in corrugated furnace tube are significantly reduced with the increase of corrugation depth. Than deformations and stresses in the structure of a fire-tube boiler were analysed in a real operating condition, for the cases of installed plain furnace tube and corrugated furnace tubes with different shapes. It was concluded that in this fire-tube boiler, which is of larger steam capacity, the corrugated furnace tube must be installed, as well as that the maximal stress in the construction is reduced by the installation of the furnace tube with greater corrugation depth. The analysis of stresses due to pressure and thermal loads pointed out that thermal stresses are not lower-order stresses in comparison to stresses due to pressure loads, so they must be taken into consideration for boiler strength analysis. [Projekat Ministarstva nauke Republike Srbije, br. TR 35040 i br. TR 35011


    Directory of Open Access Journals (Sweden)

    Petr Kracík


    Full Text Available Water flowing on a sprinkled tube bundle forms three basic modes: the Droplet mode (the liquid drips from one tube to another, the Jet mode (with an increasing flow rate, the droplets merge into a column and the Membrane (Sheet mode (with a further increase in the flow rate of the falling film liquid, the columns merge and create sheets between the tubes. With a sufficient flow rate, the sheets merge at this stage, and the tube bundle is completely covered by a thin liquid film. There are several factors influencing both the individual modes and the heat transfer. Beside the above-mentioned falling film liquid flow rate, these are for instance the tube diameters, the tube pitches in the tube bundle, or the physical conditions of the falling film liquid. This paper presents a summary of data measured at atmospheric pressure, with a tube bundle consisting of copper tubes of 12 millimetres in diameter, and with a studied tube length of one meter. The tubes are situated horizontally one above another at a pitch of 15 to 30 mm, and there is a distribution tube placed above them with water flowing through apertures of 1.0mm in diameter at a 9.2mm span. Two thermal conditions have been tested with all pitches: 15 °C to 40 °C and 15 °C to 45 °C. The temperature of the falling film liquid, which was heated during the flow through the exchanger, was 15 °C at the distribution tube input. The temperature of the heating liquid at the exchanger input, which had a constant flow rate of approx. 7.2. litres per minute, was 40 °C, or alternatively 45 °C.

  9. Pneumatosis intestinalis associated with enteral tube feeding

    National Research Council Canada - National Science Library

    Zorgdrager, Marcel; Pol, Robert


    ...). Explorative laparotomy showed an omental band adhesion without signs of ischaemia. After a short period of total parenteral nutrition PI resolved almost completely and enteral tube feeding could be continued once again...

  10. Automatic welding of stainless steel tubing (United States)

    Clautice, W. E.


    The use of automatic welding for making girth welds in stainless steel tubing was investigated as well as the reduction in fabrication costs resulting from the elimination of radiographic inspection. Test methodology, materials, and techniques are discussed, and data sheets for individual tests are included. Process variables studied include welding amperes, revolutions per minute, and shielding gas flow. Strip chart recordings, as a definitive method of insuring weld quality, are studied. Test results, determined by both radiographic and visual inspection, are presented and indicate that once optimum welding procedures for specific sizes of tubing are established, and the welding machine operations are certified, then the automatic tube welding process produces good quality welds repeatedly, with a high degree of reliability. Revised specifications for welding tubing using the automatic process and weld visual inspection requirements at the Kennedy Space Center are enumerated.

  11. Caring for Your Percutaneous Nephrostomy Tube (United States)

    ... and medication through this line.  You will be awake, relaxed, and maybe a little sleepy during the ... tube.  If you have low urine output or dark, foul- Patient Information Procedure 1. Thoroughly wash your ...

  12. Screening for Open Neural Tube Defects. (United States)

    Krantz, David A; Hallahan, Terrence W; Carmichael, Jonathan B


    Biochemical prenatal screening was initiated with the use of maternal serum alpha fetoprotein to screen for open neural tube defects. Screening now includes multiple marker and sequential screening protocols involving serum and ultrasound markers to screen for aneuploidy. Recently cell-free DNA screening for aneuploidy has been initiated, but does not screen for neural tube defects. Although ultrasound is highly effective in identifying neural tube defects in high-risk populations, in decentralized health systems maternal serum screening still plays a significant role. Abnormal maternal serum alpha fetoprotein alone or in combination with other markers may indicate adverse pregnancy outcome in the absence of open neural tube defects. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. The Choking Game on YouTube

    Directory of Open Access Journals (Sweden)

    Ellen K. Defenderfer MS


    Full Text Available The choking game (TCG is an adolescent activity in which asphyxiation is used to obtain a “high,” occasionally resulting in seizures or death. A plethora of TCG information is available through YouTube, though this content has not been evaluated recently. The current study described TCG as portrayed in YouTube videos and compared views and ratings of TCG videos to unrelated videos. The TCG videos demonstrated diverse methods of asphyxiation, with a minority showing injury to the participants. TCG videos were less likely to be commented on or rated positively than non–choking game videos. TCG prevention videos differed significantly from actual TCG videos in the way they depicted the social context of TCG. Thus, TCG videos are accessible through YouTube, but the prevention materials available on YouTube are not accurate or representative. Accurate and educational online prevention materials should be created to decrease the occurrence of TCG.

  14. Multimode Traveling-Wave Amplifier Tubes (United States)

    Buck, E.


    The paper examines the recent developments which makes the Traveling Wave Tube (TWT) more powerful and efficient as a microwave amplifier than the solid state devices. Basic workings and efficiency, which can run, but usually do not, to 55%, are examined. The dependence of the performance of a given TWT upon the qualities of the beam and the manner of its focusing is described. Also described is the development of a multistage depressed collector (MDC) and its first application to a Communication Technology Satellite (CTS) tube, a 12 GHz, coupled-cavity, 200 watt TWT, which resulted in being operated in space for nearly four years and was both the most powerful and the most efficient (around 50%) communications TWT ever flown. It is predicted that the application of efficient refocusing and MDCs, made possible by computer simulations, will greatly increase tube efficiency, and thereby make practical, new multimode tubes which operate, as least partly, in a linear fashion.

  15. Gastroenteric tube feeding: Techniques, problems and solutions

    National Research Council Canada - National Science Library

    Irina Blumenstein Yogesh M Shastri Jürgen Stein


    Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake,chronic neurological or mechanical dysphagia or gut dysfunction,and patients who are critically...

  16. Medical Informatics Idle YouTube Potential. (United States)

    Hucíková, Anežka; Babic, Ankica


    YouTube as an online video-sharing service in the context of Web 2.0 goes beyond the bounds of pure fun, for which the platform was primarily established. Nowadays, commonly to other social media, it serves also educational, informational and last but not least, marketing purposes. The importance of video sharing is supported by several predictions about video reaching over 90% of global internet traffic by 2020. Using qualitative content analysis over selected YouTube videos, paper examines the current situation of the platform's marketing potential usage by medical informatics organizations, researches and other healthcare professionals. Results of the analysis demonstrate several ways in which YouTube is already used to inform, educate or promote above-mentioned medical institutions. However, their engagement in self-promo or spreading awareness of their research projects via YouTube is considered to be low.

  17. YouTube and ‘psychiatry’ (United States)

    Gordon, Robert; Miller, John; Collins, Noel


    YouTube is a video-sharing website that is increasingly used to share and disseminate health-related information, particularly among younger people. There are reports that social media sites, such as YouTube, are being used to communicate an anti-psychiatry message but this has never been confirmed in any published analysis of YouTube clip content. This descriptive study revealed that the representation of ‘psychiatry’ during summer 2012 was predominantly negative. A subsequent smaller re-analysis suggests that the negative portrayal of ‘psychiatry’ on YouTube is a stable phenomenon. The significance of this and how it could be addressed are discussed. PMID:26755987

  18. A review of pulse tube refrigeration (United States)

    Radebaugh, Ray


    This paper reviews the development of the three types of pulse tube refrigerators: basic, resonant, and orifice types. The principles of operation are given. It is shown that the pulse tube refrigerator is a variation of the Stirling-cycle refrigerator, where the moving displacer is substituted by a heat transfer mechanism or by an orifice to bring about the proper phase shifts between pressure and mass flow rate. A harmonic analysis with phasors is described which gives reasonable results for the refrigeration power, yet is simple enough to make clear the processes which give rise to the refrigeration. The efficiency and refrigeration power are compared with those of other refrigeration cycles. A brief review is given of the research being done at various laboratories on both one- and two-stage pulse tubes. A preliminary assessment of the role of pulse tube refrigerators is discussed.

  19. Opioid Use and Neural Tube Defects (United States)

    ... . Error processing SSI file Key Findings: Opioid Use and Neural Tube Defects Recommend on Facebook ... new study that looked at the use of opioids during pregnancy and their relationship to having a ...

  20. Routine jejunostomy tube feeding following esophagectomy

    National Research Council Canada - National Science Library

    Weijs, Teus J; van Eden, Hanneke W.J; Ruurda, Jelle P.|info:eu-repo/dai/nl/257561021; Luyer, Misha D P; Steenhagen, Elles|info:eu-repo/dai/nl/304815713; Nieuwenhuijzen, Grard A P; van Hillegersberg, Richard|info:eu-repo/dai/nl/110706242


    Background: Malnutrition is an important problem following esophagectomy. A surgically placed jejunostomy secures an enteral feeding route, facilitating discharge with home-tube feeding and long-term nutritional support...

  1. Accidental Decannulation OF TRACHEOSTOMY TUBES - Case Series. (United States)

    Omokanye, H K; Dunmade, A D; Segun-Busari, S; Afolabi, O A; Habeeb, O G; Adegboye, M B; Alabi, B S


    Tracheostomy tube (TT) is usually removed in a planned manner once the patient ceases to have the condition that necessitated the procedure. Accidental decannulation or extubation refers to inadvertent removal of tracheostomy tube out of the stoma. It could prove fatal in an otherwise stable patient. We review a variety of unexpected and often-overlooked causes of accidental decannulation with suggestions on preventive measures. We therefore present three cases of accidental decannulation of tracheostomy tubes in order to report our experiences in the management of the condition. Accidental decannulation occurs both in hospitalized and patient on home care of their tracheostomy tubes. Reduction in neck circumference due to weight loss predisposes to accidental decannulation, which could be prevented by suturing the flange to the skin.

  2. Stabilization Strategies for Drift Tube Linacs

    CERN Document Server

    AUTHOR|(CDS)2085420; Lamehi Rashti, Mohammad

    The average axial electric fields in drift tube linac cavities are known to be sensitive with respect to the perturbation errors. Postcoupler is a powerful stabilizer devices that is used to reduce this sensitivity of average axial field. Postcouplers are the cylindrical rod which is extended from cavity wall toward the drift tube without touching the drift tube surface. Postcouplers need to be adjusted to the right length to stabilize the average axial field. Although postcouplers are used successfully in many projects, there is no straightforward procedure for postcouplers adjustment and it has been done almost based on trial and errors. In this thesis, the physics and characteristics of postcouplers has been studied by using an equivalent circuit model and 3D finite element method calculations. Finally, a straightforward and accurate method to adjust postcouplers has been concluded. The method has been verified by using experimental measurements on CERN Linac4 drift tube linac cavities.


    Federal Laboratory Consortium — This device is a specially designed shock tube for testing fabric samples in a controlled environment. The device determines the appropriate types of sensors to be...

  4. Metal bellows custom-fabricated from tubing (United States)


    Mandrel assembly mounted in a lathe chuck is used with a forming wheel to roll-form bellows from standard sheet metal tubing. Spacers and mandrels of various sizes custom-fabricate bellows of any desired dimensions.

  5. Inverse Kinematics of Concentric Tube Steerable Needles. (United States)

    Sears, Patrick; Dupont, Pierre E


    Prior papers have introduced steerable needles composed of precurved concentric tubes. The curvature and extent of these needles can be controlled by the relative rotation and translation of the individual tubes. Under certain assumptions on the geometry and design of these needles, the forward kinematics problem can be solved in closed form by means of algebraic equations. The inverse kinematics problem, however, is not as straightforward owing to the nonlinear map between relative tube displacements and needle tip configuration as well as to the multiplicity of solutions as the number of tubes increases. This paper presents a general approach to solving the inverse kinematics problem using a pseudoinverse solution together with gradients of nullspace potential functions to enforce geometric and mechanical constraints.

  6. Optimizing Tube Precurvature to Enhance Elastic Stability of Concentric Tube Robots. (United States)

    Ha, Junhyoung; Park, Frank C; Dupont, Pierre E


    Robotic instruments based on concentric tube technology are well suited to minimally invasive surgery since they are slender, can navigate inside small cavities and can reach around sensitive tissues by taking on shapes of varying curvature. Elastic instabilities can arise, however, when rotating one precurved tube inside another. In contrast to prior work that considered only tubes of piecewise constant precurvature, we allow precurvature to vary along the tube's arc length. Stability conditions for a planar tube pair are derived and used to formulate an optimal design problem. An analytic formulation of the optimal precurvature function is derived that achieves a desired tip orientation range while maximizing stability and respecting bending strain limits. This formulation also includes straight transmission segments at the proximal ends of the tubes. The result, confirmed by both numerical and physical experiment, enables designs with enhanced stability in comparison to designs of constant precurvature.


    Lebo, Charles P.


    The Snorkel tracheotomy tube, a simple modification of the standard tube, overcomes many of the mechanical inconveniences usually encountered in the care of patients with tracheotomy who have to be kept in respirators. With it in place, it is not necessary to use special devices to hold the collar of the respirator away from the site of the tracheal incision. Nursing care of the patient is made easier. ImagesFigure 2.Figure 3. PMID:13182610

  8. Accidental Decannulation OF TRACHEOSTOMY TUBES - Case Series


    Omokanye, HK; Dunmade, AD; Segun-Busari, S; Afolabi, OA; Habeeb, OG; Adegboye, MB; Alabi, BS


    Tracheostomy tube (TT) is usually removed in a planned manner once the patient ceases to have the condition that necessitated the procedure. Accidental decannulation or extubation refers to inadvertent removal of tracheostomy tube out of the stoma. It could prove fatal in an otherwise stable patient. We review a variety of unexpected and often-overlooked causes of accidental decannulation with suggestions on preventive measures. We therefore present three cases of accidental decannulation of ...

  9. A Flue Gas Tube for Thermoelectric Generator

    DEFF Research Database (Denmark)


    The invention relates to a flue gas tube (FGT) (1) for generation of thermoelectric power having thermoelectric elements (8) that are integrated in the tube. The FTG may be used in combined heat and power (CHP) system (13) to produce directly electricity from waste heat from, e.g. a biomass boiler....... The CHP system may also be operated in a heating or cooling mode, thus being able to heat or cool water by feeding electricity to the system....

  10. Explosively Bonded Gun Tube Liner Development (United States)


    some concern was the occasional appearance of iron-Ta intermetallics near the liner-steel interface. This is a brittle phase and subject to...Montgomery JS, de Rosset WS. Examination of intermetallic phases and residual stresses resulting from explosive bonding of refractory metal gun tube...caliber smoothbore gun tube. The metallic bond produced by explosive bonding is extremely strong and presumably would keep the liner in place. In Phase

  11. Tube current reduction in pediatric non-ECG-gated heart CT by combined tube current modulation. (United States)

    Goo, Hyun Woo; Goo, Hyum Woo; Suh, Dong Soo


    Dose reduction by combined tube current modulation has not been evaluated in pediatric low-dose CT. This study was performed to evaluate tube current reduction in non-ECG-gated heart CT angiography in children by combined tube current modulation, and to assess the effects of body weight, age, sex, and scan direction on tube current reduction. From September 2004 to January 2005, non-ECG-gated heart CT examinations were performed with combined tube current modulation in 50 children (median age 1 year, range 1 month to 16 years; M/F 29/21) with congenital heart disease. Sixteen-slice spiral CT studies were obtained using a weight-based low-dose protocol (80 kVp, 50-160 effective mA). CT scans were obtained in the craniocaudal direction when leg veins (n=36) were used for IV injection of contrast agent and in the caudocranial direction when arm veins (n=13) were used. In one child who underwent a Fontan operation, both arm and leg veins were used. We calculated tube current reduction by combined tube current modulation and evaluated the effects of body weight, age, sex, and scan technique on tube current reduction. The quality of CT angiography images was visually evaluated by an experienced pediatric radiologist. Overall tube current reduction by combined tube current modulation was 15.8+/-11.1%. The reduction was variable among five body weight groups (9.3+/-7.9% for ECG-gated heart CT by 15.8% without degradation of image quality. With our CT protocol, for body weights up to 39.9 kg, age showed a significant positive correlation with tube current reduction, but there was a lower dose-saving effect in children heavier than 40 kg. Tube current reduction was not affected by sex, but was affected by scan direction.

  12. Investigations on high-pressure ribbed tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kling, G.


    During hydrogenation of coal, the reactants (coal paste and hydrogen) had to be heated to reaction temperature partly by heat exchange with products and partly by heating in hairpin tubes of a preheater. These hairpin tubes were heated externally by hot circulating gases. In order to improve heat transfer from the gases to the tubes, various types of metal ribbing were welded to the tubes to catch more heat and transfer it to the tubes. This report detailed some studies on the best shapes and dimensions and numbers of plates to be used. The report was limited to flat, rectangular-cross-section plates attached perpendicularly, instead of including flat circular plates, spiral plates, or other configurations. The advantage of greater surface area to catch more heat had to be balanced off against the disadvantage of greater surface area to absorb more heat in internal resistance to heat flow. The report described the experimental conditions, the modifications tested, and the shape decided upon as best for flat plates. Some of the diagrams illustrating temperature distributions around the tubes and ribs were presented in imitation three-dimenional formats. 16 figures.

  13. Advanced Ultrasupercritical (AUSC) Tube Membrane Panel Development

    Energy Technology Data Exchange (ETDEWEB)

    Pschirer, James [Alstom Power Inc., Windsor, CT (United States); Burgess, Joshua [Alstom Power Inc., Windsor, CT (United States); Schrecengost, Robert [Alstom Power Inc., Windsor, CT (United States)


    Alstom Power Inc., a wholly owned subsidiary of the General Electric Company (GE), has completed the project “Advanced Ultrasupercritical (AUSC) Tube Membrane Panel Development” under U.S. Department of Energy (DOE) Award Number DE-FE0024076. This project was part of DOE’s Novel Crosscutting Research and Development to Support Advanced Energy Systems program. AUSC Tube Membrane Panel Development was a two and one half year project to develop and verify the manufacturability and serviceability of welded tube membrane panels made from high performance materials suitable for the AUSC steam cycles, defined as high pressure steam turbine inlet conditions of 700-760°C (1292-1400°F) and 24.5-35MPa (3500-5000psi). The difficulty of this challenge lies in the fact that the membrane-welded construction imposes demands on the materials that are unlike any that exist in other parts of the boiler. Tube membrane panels have been designed, fabricated, and installed in boilers for over 50 years with relatively favorable experience when fabricated from carbon and Cr-Mo low alloy steels. The AUSC steam cycle requires membrane tube panels fabricated from materials that have not been used in a weldment with metal temperatures in the range of 582-610°C (1080-1130°F). Fabrication materials chosen for the tubing were Grade 92 and HR6W. Grade 92 is a creep strength enhanced ferritic Cr-Mo alloy and HR6W is a high nickel alloy. Once the materials were chosen, GE performed the engineering design of the panels, prepared shop manufacturing drawings, and developed manufacturing and inspection plans. After the materials were purchased, GE manufactured and inspected the tube membrane panels, determined if post fabrication heat treatment of the tube membrane panels was needed, performed pre- and post-weld heat treatment on the Grade 92 panels, conducted final nondestructive inspection of any heat treated tube membrane panels, conducted destructive inspection of the completed tube

  14. Testing of Colorimetric Tubes for Nitrogen Dioxide and Monomethylhydrazine. (United States)

    Diamond, Philip

    Colorimetric tubes for nitrogen dioxide (NO2) and monomethylhydrazine (MMH) were tested for accuracy and results indicate that at the levels checked the tubes' average deviation was plus or minus 20 percent. Tube NO2 concentrations all read lower than the analyzed concentrations. MMH tubes read much higher than the analyzed concentration of 0.28…

  15. 16 CFR 1507.12 - Multiple-tube fireworks devices. (United States)


    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Multiple-tube fireworks devices. 1507.12... REGULATIONS FIREWORKS DEVICES § 1507.12 Multiple-tube fireworks devices. (a) Application. Multiple-tube mine and shell fireworks devices with any tube measuring 1.5 inches (3.8 cm) or more in inside diameter and...

  16. 21 CFR 888.4230 - Cement ventilation tube. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device usually made of plastic intended to be inserted into...

  17. 46 CFR 153.979 - Gauging with a sounding tube. (United States)


    ... 46 Shipping 5 2010-10-01 2010-10-01 false Gauging with a sounding tube. 153.979 Section 153.979... Procedures § 153.979 Gauging with a sounding tube. (a) No person may remove the cover of a sounding tube... cargo transfer may not authorize removal of the cover from a sounding tube gauge unless all tank...

  18. 21 CFR 870.4390 - Cardiopulmonary bypass pump tubing. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pump tubing. 870.4390... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is... through the cardiopulmonary bypass circuit. (b) Classification. Class II (performance standards). ...

  19. Development, prevention, and treatment of feeding tube dependency

    NARCIS (Netherlands)

    Krom, Hilde; de Winter, J. Peter; Kindermann, Angelika


    Enteral nutrition is effective in ensuring nutritional requirements and growth. However, when tube feeding lasts for a longer period, it can lead to tube dependency in the absence of medical reasons for continuation of tube feeding. Tube-dependent children are unable or refuse to start oral

  20. Acoustic Resonance in Cylindrical Tubes with Side Branches (United States)


    branches and tubes that change diameter. 4. Musical Instrument Design A flute is essentially a hollow tube with a way at one end to modulate integer (1,2,3,…). 12 Figure 5. Tube with no holes. The addition of a side branch effectively changes the length of the tube, so in a flute

  1. General tube law for collapsible thin and thick-wall tubes. (United States)

    Kozlovsky, Pavel; Zaretsky, Uri; Jaffa, Ariel J; Elad, David


    Modeling the complex deformations of cylindrical tubes under external pressure is of interest in engineering and physiological applications. The highly non-linear post-buckling behavior of cross-section of the tube during collapse attracted researchers for years. Major efforts were concentrated on studying the behavior of thin-wall tubes. Unfortunately, the knowledge on post-buckling of thick-wall tubes is still incomplete, although many experimental and several theoretical studies have been performed. In this study we systematically studied the effect of the wall thickness on post-buckling behavior of the tube. For this purpose, we utilized a computational model for evaluation of the real geometry of the deformed cross-sectional area due to negative transmural (internal minus external) pressure. We also developed an experimental method to validate the computational results. Based on the computed cross-sections of tubes with different wall thicknesses, we developed a general tube law that accounts for thin or thick wall tubes and fits the numerical data of computed cross-sectional areas versus transmural pressures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Automated Determination of Oxygen-Dependent Enzyme Kinetics in a Tube-in-Tube Flow Reactor

    DEFF Research Database (Denmark)

    Ringborg, Rolf Hoffmeyer; Pedersen, Asbjørn Toftgaard; Woodley, John


    and limited oxygen supply. Here, we present a novel method for the collection of such kinetic data using a pressurized tube-in-tube reactor, operated in the low-dispersed flow regime to generate time-series data, with minimal material consumption. Experimental development and validation of the instrument...

  3. Fluid heating by current injection tubes; Chauffage de fluides par tubes a passage de courant

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, L.S. [Societe Parmilleux (France)


    Current injection tube technology may be applied in compact fluid heating installation with a very low level of thermal inertia. The technology is particularly suitable for heating heat-sensitive fluids or those with a tendency to foul other types of installations. Specific advantages of current injection tubes include the elimination of cold spots and their reduced volume requirements. (author)


    Directory of Open Access Journals (Sweden)

    Habib Rahaman


    Full Text Available Maxillofacial procedure such as LeFort I osteotomy requires Transmyelohyoid Intubation. For that initial intubation is done with Flexometallic Endotracheal Tube so that this tube can be easily brought out through transmyelohyoid incision. Frequently Flexometallic tubes are reused after Ethylene Oxide Sterilisation because of high Cost. Here we present an obstruction to endotracheal tube at an unusual location, (Deformity of the tube at the level of Cuff, with intact cuff.

  5. Automated Diagnosis and Classification of Steam Generator Tube Defects

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Gabe V. Garcia


    A major cause of failure in nuclear steam generators is tube degradation. Tube defects are divided into seven categories, one of which is intergranular attack/stress corrosion cracking (IGA/SCC). Defects of this type usually begin on the outer surface of the tubes and propagate both inward and laterally. In many cases these defects occur at or near the tube support plates. Several different methods exist for the nondestructive evaluation of nuclear steam generator tubes for defect characterization.

  6. Folate receptors and neural tube closure. (United States)

    Saitsu, Hirotomo


    Neural tube defects (NTD) are among the most common human congenital malformations, affecting 0.5-8.0/1000 of live births. Human clinical trials have shown that periconceptional folate supplementation significantly decreases the occurrence of NTD in offspring. However, the mechanism by which folate acts on NTD remains largely unknown. Folate receptor (Folr) is one of the three membrane proteins that mediate cellular uptake of folates. Recent studies suggest that mouse Folr1 (formerly referred to as Fbp1) is essential for neural tube closure. Therefore, we examined spatial and temporal expression patterns of Folr1 in developing mouse embryos, showing a close association between Folr1 and anterior neural tube closure. Transient transgenic analysis was performed using lacZ as a reporter; we identified a 1.1-kb enhancer that directs lacZ expression in the neural tube and optic vesicle in a manner that is similar to endogenous Folr1. The 1.1-kb enhancer sequences were highly conserved between humans and mice, suggesting that human FOLR1 is associated with anterior neural tube closure in humans. Several experimental studies in mice and human epidemiological and genetics studies have suggested that folate receptor abnormalities are involved in a portion of human NTDs, although the solo defect of FOLR1 did not cause NTD. © 2017 Japanese Teratology Society.

  7. Geiger-Muller tubes and their manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Gair, S.A.; Copleston, R.E.


    A Geiger-Muller tube designed for use in an environment subjected to mechanical shock and vibration has a tensioned anode wire secured between first and second mounts located at opposite ends of the tube envelope. The wire tension is adjusted, preferably with a screwable-adjustment means which is locked in the adjusted position, so that the natural frequency of vibration of the tensioned wire does not resonate with any frequency to which the tube is subjected in use. The adjustment means may be included in the mount via which the envelope is evacuated and back-filled with the ionizable gas, and a gas-tight seal can be provided around this part of the mount for example by sealing off the gas pump tube. However the adjustment means may be designed into another part of the tube, for example using telescopic parts of the envelope whose sliding junction is made gas tight with a flexible seal. Alternatively, the desired tension may be obtained by welding the wire to the first mount, passing it through the second mount, tensioning it and then crimping it to the second mount. (Author).

  8. Administration of antiretroviral medication via enteral tubes. (United States)

    Prohaska, Emily S; King, Allison R


    Case reports and other published or manufacturer-provided data on the administration of antiretroviral agents through enteral feeding tubes are reviewed. There is very limited published evidence to guide clinicians in the delivery of therapies for human immunodeficiency virus (HIV) infection by feeding tubes, especially crushed tablets and capsule contents. A search of the primary literature (through February 2012) identified a total of nine articles describing the delivery of highly active antiretroviral therapy (HAART) agents via gastrostomy (G), jejunostomy, and other feeding tubes; correspondence with pharmaceutical manufacturers yielded additional information. Most of the published evidence (from two prospective studies, one retrospective study, and six case reports) pertains to the treatment of HIV-infected children (33 of 40 cases). Although not a primary endpoint of any of the reviewed studies, viral suppression was documented in 29 of the 40 patients referenced in the reviewed articles. Manufacturer-provided information indicates that crushed darunavir tablets in suspension, as well as oral solutions of ritonavir and lopinavir-ritonavir, can be administered through G-tubes without significant loss of therapeutic efficacy. Data regarding enteral feeding tube administration are available for 63% of commercially available oral HAART agents and are primarily limited to case reports specific to the pediatric population.

  9. Jejunostomy tube feeding in patients undergoing esophagectomy. (United States)

    Srinathan, Sadeesh K; Hamin, Tamara; Walter, Stephen; Tan, A Lawrence; Unruh, Helmut W; Guyatt, Gordon


    Surgical jejunostomy tubes are a routine part of elective esophagectomies in patients with carcinomas and provide a route for nutritional support in those who experience complications. We wished to determine how frequently oral intake is delayed and the amount of nutrition delivered via the jejunostomy tube. We reviewed the charts of all adults undergoing esophagectomy for carcinoma between January 2000 and June 2008. We determined the proportion of patients unable to resume oral nutrition after 8 days and the amount of nutrition delivered in each of the 8 days. In all, 111 patients underwent elective esophagectomy for carcinoma, and 103 had a jejunostomy tube placed. The mean age was 67 ± 10.8 years. The median time to oral intake was 7 (interquartile range 7-11) days. Seventy-four (67%) patients resumed oral intake within 8 days. The mean nutrition delivered by jejunostomy within the first 8 days as a percentage of the target was 45.6% (95% confidence interval 41.2%-49.9%). Six (5.4%) patients experienced complications attributable solely to the jejunostomy tube; 3 (2.9%) required surgery. Forty (38.8%) patients had abdominal issues serious enough to warrant delaying the progression of feeding. Two-thirds of patients undergoing elective esophagectomy were tolerating oral intake by the end of the eighth postoperative day, and less than half of the target nutrition was delivered over the first 8 days. We now selectively place surgical jejunostomy tubes in patients undergoing elective esophagectomies.

  10. Design and evaluate finned tube bundles

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. [ABCO Industries, Abilene, TX (United States)


    Finned tube bundles are widely used in heat exchangers, air coolers, waste heat boilers and fired heaters where energy transfer occurs between clean flue gases and a fluid with a high heat-transfer coefficient. They have several advantages including compactness, low gas pressure drop and low weight for a given duty compared to bare tube bundles. Choosing a fin type, arrangement and fin configuration requires a thorough analysis and economic evaluation. The solution is not unique since it depends on material and labor costs. Surface areas vary widely in finned tube designs for the same duty and gas pressure drop. Therefore, decisions should not be based on surface area alone. Plant engineers and consultants should consider operating costs in their evaluation because they accrue year after year. Selecting a boiler based on initial costs alone is not prudent. The paper discusses heat transfer and gas pressure drop with finned tubes, determining fin efficiency and effectiveness,g as pressure drop, tube wall and fin top temperatures, an example calculation, the effect of fin configuration on design, the effect of inline versus staggered arrangements and solid versus serrated fins, and concerns with high fin-density designs.

  11. Construction of preheaters with horizontal tubes

    Energy Technology Data Exchange (ETDEWEB)



    This report involved construction of preheaters for distillation and cracking plants in the oil industry, particularly in America. The use of heat transmission by radiation was also a consideration here. The recycling of waste gases occurred, but was not the rule. A convection section was often built next to the radiation section, in which the discharge gases were used for heating the incoming product. The general arrangement of the preheaters was discussed. The first form was a rectangular box with fireproof lining with tubes arranged in a single row along the outer walls and sometimes in a double row on the ceiling. It consisted of smooth and finned tubes. From the simple form a double preheater was developed that allowed one or two common discharge flues to provide as large a heating surface as possible within a reasonable space. Other items discussed were recycling of waste gases, reasons for the choice of horizontal preheaters with radiation heating, the use of vertical tubes in the U.S.A. and elsewhere in the oil industry, details of horizontal preheater tubes, end closures, material, suspension, protection against overloading by radiation, circulation heating, burners, use of horizontal radiation preheaters in hydrogenation in the U.S.A., rebuilding I. G. preheaters, construction, tube supports, and masonry. A list of references on cracking, preheaters, heat transmission, and alloyed steels was given.

  12. Mechanical properties of ceramic composite tubes

    Energy Technology Data Exchange (ETDEWEB)

    Curtin, W.A.; Oleksuk, L.L.; Reifsnider, K.L. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Stinton, D.P. [Oak Ridge National Lab., TN (United States)


    Results of axial tension tests on SiC/SiC tubular ceramic composite components fabricated by a forced-M technique are presented. Axial elastic modulus measurements on a number of tubes show that the Young`s modulus varies along the length of the tube, with occasional very stiff or very soft regions. Tests to failure on a few tubes show the initiation of non-linear stress-strain behavior to be in the range of 3-9 ksi, followed by extensive non-linear deformation up to failure. For one tube, the failure stress obtained was 20.1 ksi, but the strains to failure at various axial locations varies from 0.19%to 0.24%. The correlation between modulus and proportional limit is considered within the ACK matrix cracking theory and within a model in which matrix cracking between fiber tows occurs, both modified to account for matrix porosity. The crack size required to cause stress concentrations large enough to cause failure at the observed strength is considered. Predictions for both matrix cracking and strength suggest that the current generation of tubes are controlled by microstructural defects.

  13. Air liquide's space pulse tube cryocooler systems (United States)

    Trollier, T.; Tanchon, J.; Buquet, J.; Ravex, A.


    Thanks to important development efforts completed with ESA funding, Air Liquide Advanced Technology Division (AL/DTA), is now in position to propose two Pulse Tube cooler systems in the 40-80K temperature range for coming Earth Observation missions such as Meteosat Third Generation (MTG), SIFTI, etc… The Miniature Pulse Tube Cooler (MPTC) is lifting up to 2.47W@80K with 50W compressor input power and 10°C rejection temperature. The weight is 2.8 kg. The Large Pulse Tube Cooler (LPTC) is providing 2.3W@50K for 160W input power and 10°C rejection temperature. This product is weighing 5.1 kg. The two pulse tube coolers thermo-mechanical units are qualified against environmental constraints as per ECSS-E-30. They are both using dual opposed pistons flexure bearing compressor with moving magnet linear motors in order to ensure very high lifetime. The associated Cooler Drive Electronics is also an important aspect specifically regarding the active control of the cooler thermo-mechanical unit during the launch phase and the active reduction of the vibrations induced by the compressor (partly supported by the French Agency CNES). This paper details the presentation of the two Pulse Tube Coolers together with the Cooler Drive Electronics aspects.

  14. Detailed Root Cause Analysis of SG Tube ODSCC Indications within the Tube Sheets of NPP Biblis Unit A (United States)

    Kilian, R.; Beck, J.; Lang, H.; Schönherr, T.; Widera, M.

    Biblis Unit A is a Siemens/KWU type four loop PWR equipped with SG tubing made from Stainless Steel Alloy 800, operating from 1975 until the shutdown in 2011 due to the German political decision of a quick nuclear phase out. During the regular SG tubing inspections using eddy current testing in 2005 and 2006, a few SG tube indications were detected within the tube sheet between upper and lower mechanical tube expansion. These indications were limited to the outer tube bundle periphery. As a consequence two tubes with EC indications were pulled in 2006 for further investigations. The destructive examinations revealed axially oriented cracks starting from the outer tube surface (ODSCC). The analysis of the debris from the upper expansion area clearly indicated the presence of secondary side water in the volume between tube sheet and SG tube. Penetration of secondary side water is only possible by a penetration path along the upper expansion.

  15. Direct ophthalmoscopy on YouTube

    DEFF Research Database (Denmark)

    Borgersen, Nanna Jo; Henriksen, Mikael Johannes Vuokko; Konge, Lars


    BACKGROUND: Direct ophthalmoscopy is well-suited for video-based instruction, particularly if the videos enable the student to see what the examiner sees when performing direct ophthalmoscopy. We evaluated the pedagogical effectiveness of instructional YouTube videos on direct ophthalmoscopy...... in general. We then systematically searched YouTube. Two authors reviewed eligible videos to assess eligibility and extract data on video statistics, content, and approach to visualization. Correlations between video statistics and contents were investigated using two-tailed Spearman's correlation. RESULTS...... the patient and how to examine the fundus. Time spent on fundus examination correlated with the number of views per week (Spearman's ρ=0.53; P=0.029). CONCLUSION: Videos may help overcome the pedagogical issues in teaching direct ophthalmoscopy; however, the few available videos on YouTube fail to address...

  16. Circumferential cracking of steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Karwoski, K.J.


    On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.

  17. Pneumatosis intestinalis associated with enteral tube feeding. (United States)

    Zorgdrager, Marcel; Pol, Robert


    A 49-year-old man presented with a Hinchey II perforated diverticulitis and underwent laparoscopic peritoneal lavage. During the postoperative course the patient received enteral tube feeding which was followed by a bowel obstruction accompanied with pneumatosis intestinalis (PI). Explorative laparotomy showed an omental band adhesion without signs of ischaemia. After a short period of total parenteral nutrition PI resolved almost completely and enteral tube feeding could be continued once again. In the weeks that followed the patient developed atypical bowel symptoms and recurrent PI which resolved each time the drip feeding was discontinued. Despite the mild clinical course, a CT scan showed massive PI on day 21 after the laparotomy. After excluding life-threatening conditions conservative management was instituted and the patient recovered completely after discontinuing the drip feeding. We present one of the few cases of subclinical PI associated with enteral tube feeding that could be managed conservatively.

  18. Plasmonic band structures in doped graphene tubes. (United States)

    Zhou, Yu; Zhu, Ying-Ying; Zhang, Kun; Wu, Hong-Wei; Peng, Ru-Wen; Fan, Ren-Hao; Wang, Mu


    We present theoretically the transport of plasmonic waves in doped graphene tube, which is made by rolling planar graphene sheet into a cylinder and periodic doping is applied on it. It is shown that periodic modulation of the Fermi level along the tube can open gaps in the dispersion relations of graphene plasmons and eventually create plasmonic band structures. The propagation of graphene plasmons is forbidden within the bandgaps; while within the band, the plasmonic waves present axially-extended field distributions and propagate along the tubes, yet well confined around the curved graphene surface. Furthermore, the bandgaps, propagation constants and propagation lengths of the modes in plasmonic band structures are significantly tuned by varying the Fermi level of graphene, which provides active controls over the plasmonic waves. Our proposed structures here may provide an approach to dynamically control the plasmonic waves in graphene-based subwavelength waveguides.

  19. Digital Radiography Qualification of Tube Welding (United States)

    Carl, Chad


    The Orion Project will be directing Lockheed Martin to perform orbital arc welding on commodities metallic tubing as part of the Multi Purpose Crew Vehicle assembly and integration process in the Operations and Checkout High bay at Kennedy Space Center. The current method of nondestructive evaluation is utilizing traditional film based x-rays. Due to the high number of welds that are necessary to join the commodities tubing (approx 470), a more efficient and expeditious method of nondestructive evaluation is desired. Digital radiography will be qualified as part of a broader NNWG project scope.

  20. Energy absorption of braided composite tubes (United States)

    Beard, Shawn Joseph

    In this investigation, a model was developed for simulating the crushing behavior and predicting the energy absorption characteristics of braided composite tubes. The crushing model uses the finite element code ABAQUS along with a material module that describes the constitutive behavior of the braid material. The material module contains a three-dimensional description of the braid geometry, which is used to calculate the effective stiffnesses of a representative volume. The stiffness calculations include the effects of nonlinear shear, damage accumulation, and scissoring and jamming of the braider tows. A stiffness reduction scheme, based on the predicted failure mode, is used to account for tow and resin failure throughout the representative volume. Scissoring of the braider tows results in an increase in the overall effective compliance until jamming occurs. To facilitate the model development, extensive coupon tests and tube crushing experiments were conducted. Coupon tests were conducted on braided flat plaques to help characterize the damage mechanisms occurring and to obtain the initial stiffnesses for verifying the proposed model. The braided flat plaques were made using 80k Akzo Nobel Fortafil carbon fiber tows for both the axial and braider tows, and Hetron 922 epoxy-vinyl ester resin for the matrix. Crushing tests were conducted on braided carbon fiber/epoxy-vinyl ester composite tubes with both circular and square cross-sections. All tests were conducted quasi-statically, and plug-type initiators were used to trigger the progressive crushing. The braided tubes were made using 80k Akzo Nobel Fortafil carbon fiber tows for the axial tows, 12k Hercules Grafil 34-700 carbon fiber tows for the braider tows, and Hetron 922 epoxy-vinyl ester resin for the matrix. The energy absorption characteristics are significantly affected by the fiber architecture of the tube and the fillet radius of the initiator plug. In order to verify the proposed model, simulation

  1. Pulse tube coolers for Meteosat third generation (United States)

    Butterworth, James; Aigouy, Gérald; Chassaing, Clement; Debray, Benoît; Huguet, Alexandre


    Air Liquide's Large Pulse Tube Coolers (LPTC) will be used to cool the focal planes of the Infrared Sounder (IRS) and Flexible Combined Imager (FCI) instruments aboard the ESA/Eumetsat satellites Meteosat Third Generation (MTG). This cooler consists of an opposed piston linear compressor driving a pulse tube cold head and the associated drive electronics including temperature regulation and vibration cancellation algorithms. Preparations for flight qualification of the cooler are now underway. In this paper we present results of the optimization and qualification activities as well as an update on endurance testing.

  2. Arrested Bubble Rise in a Narrow Tube (United States)

    Lamstaes, Catherine; Eggers, Jens


    If a long air bubble is placed inside a vertical tube closed at the top it can rise by displacing the fluid above it. However, Bretherton found that if the tube radius, R, is smaller than a critical value Rc=0.918 ℓ _c, where ℓ _c=√{γ /ρ g} is the capillary length, there is no solution corresponding to steady rise. Experimentally, the bubble rise appears to have stopped altogether. Here we explain this observation by studying the unsteady bubble motion for Rmotion.

  3. Nitrous oxide use and endotracheal tube rupture. (United States)

    Mosby, E L; Schelkun, P M; Vincent, S K


    Nitrous oxide is an important and widely used anesthetic agent. However, during lengthy surgical procedures, significant amounts of nitrous oxide diffuse into the endotracheal tube cuff, causing sequelae that may include increased cuff pressures, tracheal trauma, increased postoperative discomfort, and cuff rupture. In this paper, two cases are presented in which the endotracheal tube cuff used to deliver this anesthetic agent ruptured after more than four hours of surgery. Two simple means of limiting the diffusion of nitrous oxide into the cuff and thus preventing this occurrence are described.

  4. Self-assembling segmented coiled tubing

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, David W.


    Self-assembling segmented coiled tubing is a concept that allows the strength of thick-wall rigid pipe, and the flexibility of thin-wall tubing, to be realized in a single design. The primary use is for a drillstring tubular, but it has potential for other applications requiring transmission of mechanical loads (forces and torques) through an initially coiled tubular. The concept uses a spring-loaded spherical `ball-and-socket` type joint to interconnect two or more short, rigid segments of pipe. Use of an optional snap ring allows the joint to be permanently made, in a `self-assembling` manner.

  5. Geology of selected lava tubes in the Bend Area, Oregon (United States)

    Greely, R.


    Longitudinal profiles representing 5872.5 m of mapped lava tubes and a photogeologic map relating lava tubes to surface geology, regional structure and topography are presented. Three sets of lava tubes were examined: (1) Arnold Lava Tube System (7km long) composed of collapsed and uncollapsed tube segments and lava ponds, (2) Horse Lava Tube System (11 km long) composed of parallel and anastomosing lava tube segments, and (3) miscellaneous lava tubes. Results of this study tend to confirm the layered lava hypothesis of Ollier and Brown (1965) for lava tube formation; however, there are probably several modes of formation for lava tubes in general. Arnold System is a single series of tubes apparently formed in a single basalt flow on a relatively steep gradient. The advancing flow in which the tubes formed was apparently temporarily halted, resulting in the formation of lava ponds which were inflated and later drained by the lava tube system. Horse System probably formed in multiple, interconnected flows. Pre-flow gradient appears to have been less than for Arnold System, and resulted in meandrous, multiple tube networks.

  6. Everything the nurse practitioner should know about pediatric feeding tubes. (United States)

    Hannah, Erin; John, Rita Marie


    To provide an overview of the current feeding tubes in use in the pediatric population including feeding tube complications, and specific guidance for patients at the initiation, throughout the use of, and at the discontinuation of tube feeding. A review of the literature was performed using multiple databases including PubMed, CINAHL, Ovid Medline, and Cochrane Library. Key words used included pediatric gastrostomy (G) tubes, nasogastric (NG) tubes, gastrojejunostomy (GJ) tubes, enteral access, and nurse practitioner (NP). Any child who cannot obtain nutrition orally is a candidate for enteral feeding tube access. Tube feeding is the recommended care guideline for children that are undernourished or unable to safely take-in oral nutrition. Tube feeding has been known to improve health-related quality of life. There are a number of different forms of feeding tubes that can be used in children, including NG, orogastric, G, and GJ tubes. Children are being sent home regularly with enteral feeding tube access and NPs will encounter these patients in everyday practice. It is important that NPs know the risks and benefits of tube feeding as well as the types of tubes currently in use and their indications, advantages, disadvantages, and complications. ©2013 The Author(s) ©2013 American Association of Nurse Practitioners.

  7. Wave function properties of a single and a system of magnetic flux tube(s) oscillations (United States)

    Esmaeili, Shahriar; Nasiri, Mojtaba; Dadashi, Neda; Safari, Hossein


    In this study, the properties of wave functions of the MHD oscillations for a single and a system of straight flux tubes are investigated. Magnetic flux tubes with a straight magnetic field and longitudinal density stratification were considered in zero-β approximation. A single three-dimensional wave equation (eigenvalue problem) is solved for longitudinal component of the perturbed magnetic field using the finite element method. Wave functions (eigenfunction of wave equation) of the MHD oscillations are categorized into sausage, kink, helical kink, and fluting modes. Exact recognition of the wave functions and the frequencies of oscillations can be used in coronal seismology and also helps to the future high-resolution instruments that would be designed for studying the properties of the solar loop oscillations in details. The properties of collective oscillations of nonidentical and identical system of flux tubes and their interactions are studied. The ratios of frequencies, the oscillation frequencies of a system of flux tubes to their equivalent monolithic tube (ω sys/ω mono), are obtained between 0.748 and 0.841 for a system of nonidentical tubes, whereas the related ratios of frequencies for a system of identical flux tubes are fluctuated around 0.761.

  8. Influence of tube spinning on formability of friction stir welded aluminum alloy tubes for hydroforming application

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.S. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Hu, Z.L., E-mail: [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Hubei Key Laboratory of Advanced Technology of Automobile Parts, Wuhan University of Technology, Wuhan 430070 (China); State Key Laboratory of Materials Processing and Die and Mould Technology, Huazhong University of Science and Technology (China); Yuan, S.J. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Hua, L. [Hubei Key Laboratory of Advanced Technology of Automobile Parts, Wuhan University of Technology, Wuhan 430070 (China)


    Due to economic and ecological reasons, the application of tailor-welded blanks of aluminum alloy has gained more and more attention in manufacturing lightweight structures for automotives and aircrafts. In the study, the research was aimed to highlight the influence of spinning on the formability of FSW tubes. The microstructural characteristics of the FSW tubes during spinning were studied by electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM). The formability of the FSW tubes with different spinning reduction was assessed by hydraulic bulge test. It is found that the spinning process shows a grain refinement of the tube. The grains of the FSW tube decrease with increasing thickness reduction, and the effect of grain refinement is more obvious for the BM compared to that of the weld. The difference of grain size and precipitates between the weld and BM leads to an asymmetric W-type microhardness distribution after spinning. The higher thickness reduction of the tube, the more uniform distribution of grains and precipitates it shows, and consequently results in more significant increase of strength. As compared with the result of tensile test, the tube after spinning shows better formability when the stress state changes from uniaxial to biaxial stress state.

  9. Performance of pressure tubes in CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, D.; Griffiths, M.; Bickel, G.; Buyers, A.; Coleman, C.; Nordin, H.; St Lawrence, S. [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)


    The pressure tubes in CANDU reactors typically operate for times up to about 30 years prior to refurbishment. The in-reactor performance of Zr-2.5Nb pressure tubes has been evaluated by sampling and periodic inspection. This paper describes the behavior and discusses the factors controlling the behaviour of these components. The Zr–2.5Nb pressure tubes are nominally extruded at 815{sup o}C, cold worked nominally 27%, and stress relieved at 400 {sup o}C for 24 hours, resulting in a structure consisting of elongated grains of hexagonal close-packed alpha-Zr, partially surrounded by a thin network of filaments of body-centred-cubic beta-Zr. These beta-Zr filaments are meta-stable and contain about 20% Nb after extrusion. The stress-relief treatment results in partial decomposition of the beta-Zr filaments with the formation of hexagonal close-packed alpha-phase particles that are low in Nb, surrounded by a Nb-enriched beta-Zr matrix. The material properties of pressure tubes are determined by variations in alpha-phase texture, alpha-phase grain structure, network dislocation density, beta-phase decomposition, and impurity concentration that are a function of manufacturing variables. The pressure tubes operate at temperatures between 250 {sup o}C and 310 {sup o}C with coolant pressures up to about 11 MPa in fast neutron fluxes up to 4 x 10{sup 17} n·m{sup -2}·s{sup -1} (E > 1 MeV) and the properties are modified by these conditions. The properties of the pressure tubes in an operating reactor are therefore a function of both manufacturing and operating condition variables. The ultimate tensile strength, fracture toughness, and delayed hydride-cracking properties (velocity (V) and threshold stress intensity factor (K{sub IH})) change with irradiation, but all reach a nearly limiting value at a fluence of less than 10{sup 25} n·m{sup -2} (E > 1 MeV). At this point the ultimate tensile strength is raised about 200 MPa, toughness is reduced by about 50%, V increases

  10. YouTube as an information source for pediatric adenotonsillectomy and ear tube surgery. (United States)

    Sorensen, Jeffrey A; Pusz, Max D; Brietzke, Scott E


    Assess the overall quality of information on adenotonsillectomy and ear tube surgery presented on YouTube ( from the perspective of a parent or patient searching for information on surgery. The YouTube website was systematically searched on select dates with a formal search strategy to identify videos pertaining to pediatric adenotonsillectomy and ear tube surgery. Only videos with at least 5 (ear tube surgery) or 10 (adenotonsillectomy) views per day were included. Each video was viewed and scored by two independent scorers. Videos were categorized by goal and scored for video/audio quality, accuracy, comprehensiveness, and procedure-specific content. Cross-sectional study. Public domain website. Fifty-five videos were scored for adenotonsillectomy and forty-seven for ear tube surgery. The most common category was educational (65.3%) followed by testimonial (28.4%), and news program (9.8%). Testimonials were more common for adenotonsillectomy than ear tube surgery (41.8% vs. 12.8%, p=0.001). Testimonials had a significantly lower mean accuracy (2.23 vs. 2.62, p=0.02), comprehensiveness (1.71 vs. 2.22, p=0.007), and TA specific content (0.64 vs. 1.69, p=0.001) score than educational type videos. Only six videos (5.9%) received high scores in both video/audio quality and accuracy/comprehensiveness of content. There was no significant association between the accuracy and comprehensive score and views, posted "likes", posted "dislikes", and likes/dislikes ratio. There was an association between "likes" and mean video quality (Spearman's rho=0.262, p=0.008). Parents/patients searching YouTube for information on pediatric adenotonsillectomy and ear tube surgery will generally encounter low quality information with testimonials being common but of significantly lower quality. Viewer perceived quality ("likes") did not correlate to formally scored content quality. Published by Elsevier Ireland Ltd.

  11. An Exact Hot-Tube Solution For Thin Tape Helix Traveling-Wave Tube (United States)

    Wong, Patrick; Lau, Y. Y.; Gilgenbach, Ronald; Chernin, David; Hoff, Brad


    The exact hot-tube dispersion relation for a thin tape helix traveling-wave tube (TWT) is derived for the first time, based on its exact cold-tube solution. This is an attempt to provide a reliable determination of the Pierce parameters, in particular the ``AC space-charge'' parameter QC, for a realistic TWT. The determination of QC remains an outstanding issue. The numerical results from the exact formulation will be compared with other approximate models of TWT that were commonly used in the literature for QC. This work was supported by AFOSR Grant No. FA9550-15-1-0097.

  12. Microbial Contamination of Orthodontic Buccal Tubes from Manufacturers

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan


    Full Text Available This study aimed to test the sterility of new unused orthodontic buccal tubes received from manufacturers. Four different types of buccal tubes were used straight from the manufactures package without any additional sterilizing step. Of these buccal tubes tested, three genera of bacteria, implicated as opportunistic pathogens, namely Micrococcus luteus, Staphylococcus haemolyticus and Acinetobacter calcoaceticus were recovered from these buccal tubes. Our data showing microbial contamination on buccal tubes highlights the need of sterilization before clinical use. We also suggest that manufacturers should list the sterility state of orthodontic buccal tubes on their packaging or instructions stating the need for sterilization.

  13. Contrastive Analysis and Research on Negative Pressure Beam Tube System and Positive Pressure Beam Tube System for Mine Use (United States)

    Wang, Xinyi; Shen, Jialong; Liu, Xinbo


    Against the technical defects of universally applicable beam tube monitoring system at present, such as air suction in the beam tube, line clogging, long sampling time, etc., the paper analyzes the current situation of the spontaneous combustion fire disaster forecast of mine in our country and these defects one by one. On this basis, the paper proposes a research thought that improving the positive pressure beam tube so as to substitute the negative pressure beam tube. Then, the paper introduces the beam tube monitoring system based on positive pressure technology through theoretical analysis and experiment. In the comparison with negative pressure beam tube, the paper concludes the advantage of the new system and draws the conclusion that the positive pressure beam tube is superior to the negative pressure beam tube system both in test result and test time. At last, the paper proposes prospect of the beam tube monitoring system based on positive pressure technology.

  14. Liquid Oscillations in a U-Tube (United States)

    Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco; Navarro, Luis Barba


    In hydrostatics, pressure measurement with U-gauges and their relationship to density is a well-known experiment. Very little is studied or experimented with the dynamics of the movement of a liquid in a U-tube probably due to its theoretical complexity but, after all, it is a simple damped oscillating system. In this paper we present a relatively…

  15. "Fine grain Nb tube for SRF cavities"

    Energy Technology Data Exchange (ETDEWEB)

    Robert E. Barber


    Superconducting radio frequency (SRF) cavities used in charged particle linear accelerators, are currently fabricated by deep drawing niobium sheets and welding the drawn dishes together. The Nb sheet has a non-uniform microstructure, which leads to unpredictable cavity shape and surface roughness, and inconsistent "spring-back" during forming. In addition, weld zones cause hot spots during cavity operation. These factors limit linear accelerator performance and increase cavity manufacturing cost. Equal channel angular extrusion (ECAE) can be used to refine and homogenize the microstructure of Nb tube for subsequent hydroforming into SRF cavities. Careful selection of deformation and heat treatment conditions during the processing steps can give a uniform and consistent microstructure in the tube, leading to improved deformability and lower manufacturing costs. Favorable microstructures were achieved in short test samples of RRR Nb tube, which may be particularly suitable for hydroforming into SRF cavity strings. The approach demonstrated could be applicable to microstructure engineering of other tube materials including tantalum, titanium, and zirconium.

  16. Of Slot Machines and Broken Test Tubes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 5. Of Slot Machines and Broken Test Tubes. S Mahadevan. General Article Volume 19 Issue 5 May 2014 pp 395-405. Fulltext. Click here to view fulltext PDF. Permanent link: Keywords.

  17. The LI-rings in pollen tubes

    Directory of Open Access Journals (Sweden)

    H. Q. Zhang


    Full Text Available Monoclonal antibodies, which recognize the specific epitopes for pectins and arabinogalactan proteins, in connection with confocal laser scanning microscopy demonstrated the presence of a ring-like structure in the cell wall of pollen tubes of flowering plants.

  18. Cotton transformation via pollen tube pathway. (United States)

    Wang, Min; Zhang, Baohong; Wang, Qinglian


    Although many gene transfer methods have been employed for successfully obtaining transgenic cotton, the major constraint in cotton improvement is the limitation of genotype because the majority of transgenic methods require plant regeneration from a single transformed cell which is limited by cotton tissue culture. Comparing with other plant species, it is difficult to induce plant regeneration from cotton; currently, only a limited number of cotton cultivars can be cultured for obtaining regenerated plants. Thus, development of a simple and genotype-independent genetic transformation method is particularly important for cotton community. In this chapter, we present a simple, cost-efficient, and genotype-independent cotton transformation method-pollen tube pathway-mediated transformation. This method uses pollen tube pathway to deliver transgene into cotton embryo sacs and then insert foreign genes into cotton genome. There are three major steps for pollen tube pathway-mediated genetic transformation, which include injection of -foreign genes into pollen tube, integration of foreign genes into plant genome, and selection of transgenic plants.

  19. YouTube in the Science Classroom (United States)

    Everhart, Jerry


    YouTube makes it possible for teachers to capitalize on children's insatiable appetite for visually stimulating learning. Some of these videos attain "viral" status, getting passed on from person to person and by links on other sites. Not only are these popular videos viral, but developing one's own content and posting it for the world's access is…

  20. YouTube: Educational Potentials and Pitfalls (United States)

    Jones, Troy; Cuthrell, Kristen


    The instructional potential of video technology in the classroom is promising, especially in light of the 21st Century Learning Framework (Siegle, 2009). Studies show positive gains in student outcomes as a result of the integration of video technology in instruction. This article explores potential uses of YouTube as an instructional aid in…

  1. YouTube as a Participatory Culture (United States)

    Chau, Clement


    There is an explosion of youth subscriptions to original content-media-sharing Web sites such as YouTube. These Web sites combine media production and distribution with social networking features, making them an ideal place to create, connect, collaborate, and circulate. By encouraging youth to become media creators and social networkers, new…

  2. Steam generator tube integrity flaw acceptance criteria

    Energy Technology Data Exchange (ETDEWEB)

    Cochet, B. [FRAMATOME, Paris la Defense (France)


    The author discusses the establishment of a flaw acceptance criteria with respect to flaws in steam generator tubing. The problem is complicated because different countries take different approaches to the problem. The objectives in general are grouped in three broad areas: to avoid the unscheduled shutdown of the reactor during normal operation; to avoid tube bursts; to avoid excessive leak rates in the event of an accidental overpressure event. For each degradation mechanism in the tubes it is necessary to know answers to an array of questions, including: how well does NDT testing perform against this problem; how rapidly does such degradation develop; how well is this degradation mechanism understood. Based on the above information it is then possible to come up with a policy to look at flaw acceptance. Part of this criteria is a schedule for the frequency of in-service inspection and also a policy for when to plug flawed tubes. The author goes into a broad discussion of each of these points in his paper.

  3. Indications and Complications of Tube Thoracostomy with ...

    African Journals Online (AJOL)

    patients were followed up with serial chest X‑rays until certified cured. ... 1‑80 years. The most frequent indication was for malignant/ paramalignant effusion, 46 (27.5%). Others were trauma,. 44 (26.3%), Parapneumonic effusion, 20 (12%), postthoracotomy ... X-rays until certified cured before removal of the chest tube.

  4. Aspergillus DNA contamination in blood collection tubes. (United States)

    Harrison, Elizabeth; Stalhberger, Thomas; Whelan, Ruth; Sugrue, Michele; Wingard, John R; Alexander, Barbara D; Follett, Sarah A; Bowyer, Paul; Denning, David W


    Fungal polymerase chain reaction (PCR)-based diagnostic methods are at risk for contamination. Sample collection containers were investigated for fungal DNA contamination using real-time PCR assays. Up to 18% of blood collection tubes were contaminated with fungal DNA, probably Aspergillus fumigatus. Lower proportions of contamination in other vessels were observed. Copyright 2010 Elsevier Inc. All rights reserved.

  5. Aspergillus DNA contamination in blood collection tubes


    Harrison, Elizabeth; Stahlberger, Thomas; Whelan, Ruth; Sugrue, Michele; Wingard, John R.; Alexander, Barbara D.; Follett, Sarah A.; Bowyer, Paul; Denning, David W.


    Fungal PCR-based diagnostic methods are at risk of contamination. Sample collection containers were investigated for fungal DNA contamination using real-time PCR assays. Up to 18% of blood collection tubes were contaminated with fungal DNA, probably A. fumigatus. Lower proportions of contamination in other vessels were observed.

  6. Kundt’s tube experiment using smartphones (United States)

    Orsola Parolin, Sara; Pezzi, Giovanni


    This article deals with a modern version of Kundt’s tube experiment. Using economic instruments and a couple of smartphones, it is possible to ‘see’ nodes and antinodes of standing acoustic waves in a column of vibrating air and to measure the speed of sound.

  7. Holding Tubes in Place for Brazing (United States)

    Ambrisco, D.; Arbino, P.


    Simple method prevents loosening due to thermal mismatch. Four segment die pushed outward against tubing wall by tapered ram. Boss on each segment of die produces dimple in wall. Ram driven by commercial pneumatic cylinder powered by air at 250 psi. Method applicable to brazing of heat exchanges, thrust chambers, and other assemblies in which thermal expansion coefficients of materials differ significantly.

  8. YouTube and Video Quizzes

    Directory of Open Access Journals (Sweden)

    Kevin YEE


    Full Text Available The Internet sensation YouTube ( has become such a force online that it was estimated in 2006 to account for a full tenth of the bandwidth by the entire Internet in the United States (WebProNews, 2007, and to use as much bandwidth in 2007 as the entire Internet had done in 2000 (Carter, 2008. Like many technological tools created with entertainment or profit in mind, YouTube can now be easily and usefully adopted by instructors for educational purposes, and indeed many professors use YouTube in their classroom teaching already (Brooks, 2000. This is especially true for passive uses of YouTube; watching videos that are already online and using them in the classroom experience to support a concept and provide another mechanism for students to connect with the topics. It is fruitful to consider Bloom's Taxonomy of Educational Objectives (Bloom & Krathwohl, 1956 when employing video or any media in the classroom to maximize the intentionality of teaching and learning. The use of video for demonstration or modeling corresponds well to Blooms levels of Knowledge, Comprehension, and Application; while case studies offer a chance to demonstrate Analysis and Synthesis, and perhaps even Evaluation, when comparing a video to information from a text book or other content.

  9. Routine jejunostomy tube feeding following esophagectomy

    NARCIS (Netherlands)

    Weijs, Teus J.|info:eu-repo/dai/nl/413993558; van Eden, Hanneke W.J.; Ruurda, Jelle P.|info:eu-repo/dai/nl/257561021; Luyer, Misha D P; Steenhagen, Elles|info:eu-repo/dai/nl/304815713; Nieuwenhuijzen, Grard A P; van Hillegersberg, Richard|info:eu-repo/dai/nl/110706242


    Background: Malnutrition is an important problem following esophagectomy. A surgically placed jejunostomy secures an enteral feeding route, facilitating discharge with home-tube feeding and long-term nutritional support. However, specific complications occur, and data are lacking that support its

  10. YouTube, dentistry, and dental education. (United States)

    Knösel, Michael; Jung, Klaus; Bleckmann, Annalen


    The objective of this study was to systematically assess the informational value, intention, source, and bias of videos related to dentistry available on the video-sharing Internet platform YouTube. YouTube ( was searched for videos related to dentistry, using the system-generated sorts "by relevance" and "most viewed" and two categories (All and Education). Each of the first thirty results was rated by two assessors filling out a questionnaire for each (total: 120). The data were subjected to statistical analysis using Cohen's kappa, Pearson's correlation coefficient tau, Mann-Whitney U-tests, and a nonparametric three-way ANOVA, including an analysis of the interaction between the sorting and category effect, with an α-level of 5 percent. The scan produced 279,000 results in the category All and 5,050 in the category Education. The analysis revealed a wide variety of information about dentistry available on YouTube. The purpose of these videos includes entertainment, advertising, and education. The videos classified under Education have a higher degree of usefulness and informational value for laypersons, dental students, and dental professionals than those found in a broader search category. YouTube and similar social media websites offer new educational possibilities that are currently both underdeveloped and underestimated in terms of their potential value. Dentists and dental educators should also recognize the importance of these websites in shaping public opinion about their profession.

  11. Flow induced pulsations generated in corrugated tubes

    NARCIS (Netherlands)

    Belfroid, S.P.C.; Swindell, R.; Tummers, R.


    Corrugated tubes can produce a tonal noise when used for gas transport, for instance in the case of flexible risers. The whistling sound is generated by shear layer instability due to the boundary layer separation at each corrugation. This whistling is examined by investigating the frequency,

  12. Indications and Complications of Tube Thoracostomy with ...

    African Journals Online (AJOL)

    Two perforations are created on the cap approximately 0.4 cm and 0.5 cm, respectively. Through the 0.4 cm perforation is. Indications and Complications of Tube Thoracostomy with Improvised Underwater Seal Bottles. SA Edaigbini, IZ Delia, MB Aminu, AA Orogade1, N Anumenechi, AD Ibrahim. Department of Surgery ...

  13. Tubes, Mono Jets, Squeeze Out and CME

    Energy Technology Data Exchange (ETDEWEB)

    Longacre, R. [Brookhaven National Lab. (BNL), Upton, NY (United States)


    Glasma Flux Tubes, Mono Jets with squeeze out flow around them plus the Chiral Magnetic Effect(CME) are physical phenomenon that generate two particle correlation with respect to the reaction plane in mid-central 20% to 30% Au-Au collision √sNN = 200.0 GeV measured at RHIC.

  14. Enrichment Monitor for 235U Fuel Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Winn, W.G.


    This report describes the performance of this prototype y-monitor of 235 Uranium enrichment. In this proposed method y-rates associated with 235U and 232U are correlated with enrichment. Instrumentation for appraising fuel tubes with this method has been assembled and tested.

  15. Tube thoracostomy: Primary management option for empyema ...

    African Journals Online (AJOL)

    Twenty three (50%) children had history of pneumonia and treatment prior to development of empyema. Thirty five (76.08%) children ... Conclusions: Majority of children with empyema thoracis are manageable with tube thoracostomy, antibiotics, physiotherapy and other supportive treatment. Few of them who fail to above ...

  16. Cutting the L3 torque tube

    CERN Multimedia

    Laurent Guiraud


    Workers cut the torque tube, with a plasma-cutting device on the L3 experiment, which closed with the LEP accelerator in 2000. L3 was housed in a huge red solenoid, which will be taken over by the ALICE detector when the new LHC is completed.

  17. Thermocouple installation in thin-walled tubes (United States)

    Curren, A. N.; Wycoff, K. C.


    Brazing process attaches thermocouples to slot in type-347 stainless steel tube flush around its circumference. Electrolytic flashing with gold enhances brazing process. This installation procedure does not significantly change calibration of thermocouples used and does not cause major wear spots in the thin-walled devices.

  18. Genetics and development of neural tube defects (United States)

    Copp, Andrew J.; Greene, Nicholas D. E.


    Congenital defects of neural tube closure (neural tube defects; NTDs) are among the commonest and most severe disorders of the fetus and newborn. Disturbance of any of the sequential events of embryonic neurulation produce NTDs, with the phenotype (e.g. anencephaly, spina bifida) varying depending on the region of neural tube that remains open. While mutation of more than 200 genes is known to cause NTDs in mice, the pattern of occurrence in humans suggests a multifactorial polygenic or oligogenic aetiology. This emphasises the importance of gene-gene and gene-environment interactions in the origin of these defects. A number of cell biological functions are essential for neural tube closure, with defects of the cytoskeleton, cell cycle and molecular regulation of cell viability prominent among the mouse NTD mutants. Many transcriptional regulators and proteins that affect chromatin structure are also required for neural tube closure, although the downstream molecular pathways regulated by these proteins is unknown. Some key signalling pathways for NTDs have been identified: over-activation of sonic hedgehog signalling and loss of function in the planar cell polarity (non-canonical Wnt) pathway are potent causes of NTD, with requirements also for retinoid and inositol signalling. Folic acid supplementation is an effective method for primary prevention of a proportion of NTDs, in both humans and mice, although the embryonic mechanism of folate action remains unclear. Folic acid-resistant cases can be prevented by inositol supplementation in mice, raising the possibility that this could lead to an additional preventive strategy for human NTDs in future. PMID:19918803

  19. Steam generator tube inspection in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Shigetaka [Japan Power Engineering and Inspection Corp., Tokyo (Japan)


    Steam generator tube inspection was first carried out in 1971 at Mihama Unit-1 that is first PWR plant in Japan, when the plant was brought into the first annual inspection. At that time, inspection was made on sampling basis, and only bobbin coil probe was used. After experiencing various kinds of tube degradations, inspection method was changed from sampling to all number of tubes, and various kinds of probes were used to get higher detectability of flaw. At present, it is required that all the tubes shall be inspected in their full length at each annual inspection using standard bobbin coil probe, and some special probes for certain plants that have susceptibility of occurrence of flaw. Sleeve repaired portion is included in this inspection. As a result of analyses of eddy current testing data, all indications that have been evaluated to be 20% wall thickness or deeper shall be repaired by either plugging or sleeving, where flaw morphology is to be a wastage or wear. Other types of flaw such as IGA/SCC are not allowed to be left inservice when those indications are detected. These inspections are performed according to inspection procedures that are approved by regulatory authority. Actual inspections are witnessed by the Japan Power engineering and inspection corporation (JAPEIC)`s inspectors during data acquisition and analysis, and they issue inspection report to authority for review and approval. It is achieved high safety performance of steam generator through this method of inspections, however. some tube leakage problems were experienced in the past. To prevent recurrence of such events, government is conducting development and verification test program for new eddy current testing technology.

  20. Fallopian tube cancer. The Roswell Park experience. (United States)

    Rose, P G; Piver, M S; Tsukada, Y


    Sixty-four patients with primary fallopian tube cancer treated at Roswell Park Memorial Institute from 1964 to 1987 underwent retrospective clinicopathologic review. In 40 patients fallopian tube cancer was the only primary, but in 24 patients primary fallopian tube cancer was part of a multifocal upper genital tract malignancy. Of the 40 patients with unifocal fallopian disease, the median survival was 28 months. Only 15% of patients were alive and disease free with follow-up ranging from 22 to 141 months (median, 90.5 months). Survival was not associated with stage of disease, tumor histology, grade, or depth of invasion in this series. Fourteen patients who received cisplatin-based chemotherapy were evaluable for response. Three patients (21%) responded; two complete and one partial. Twelve patients without clinical evidence of disease underwent second-look procedures, ten laparotomy and two laparoscopy. Four of ten second-look laparotomies were negative. Secondary debulking was done in three of four patients with gross disease, one of which had a negative third-look laparotomy. Negative laparotomy, second-look or third-look, was associated with improved survival (P = 0.016). One of the two laparoscopies was negative, but the patient recurred. In the remaining 24 patients cancer of the fallopian tube was part of a multifocal upper genital tract malignancy. In 12 patients tubal disease was invasive, and in 12, it was in situ. Separate primaries occurred in the ovaries (n = 20); uterus (n = 7); and cervix (n = 2). This represents 1.3% of ovarian malignancies treated at Roswell Park Memorial Institute during the study period. Fallopian tube cancer seems as virulent as ovarian cancer with few long-term survivors. It is frequently associated with other sites of upper genital tract malignancy. Second-look laparotomy is an important predictor of survival. Second-look laparoscopy may be useful if positive.

  1. The Educational Potential of YouTube. (United States)

    Godwin, Haley T; Khan, Murtaza; Yellowlees, Peter


    The objective of this paper was to examine the educational potential and effectiveness of a 3 min video clip of a simulation of schizophrenia published online at YouTube. Researchers examined the 267 public comments published on the video-sharing website YouTube over 8 years by viewers of a schizophrenia simulation video titled "virtual hallucinations" made in the Second Life game platform. Comments were independently categorized into six groupings, then cooperatively finalized, and qualitatively analyzed. The six categories of style of comments were "Emotional" (n = 76), "Identification" (n = 62), "Educational Interest" (n = 45), "Mocking/Displeased" (n = 36), "Game Interest" (n = 32), and "Other" (n = 25). Without any advertising or marketing by the creators, over 194,400 views of the video were recorded in 8 years, an average of about 1500 views per month. The use of YouTube with its viral marketing potential has created a vastly amplified reach for this educational offering that would otherwise have been impossible. Qualitative analysis of publically posted comments in response to the video, which were generally positive, has led to a greater understanding of public reactions to such educational offerings. YouTube videos are already a rich source of data for psychiatric researchers, and psychiatric educators should consider posting high quality video clips on publically available social media platforms such as YouTube in order to reduce public stigma about psychiatric disorders and patients.

  2. Research on temperature control and influence of the vacuum tubes with inserted tubes solar heater (United States)

    Xiao, L. X.; He, Y. T.; Hua, J. Q.


    A novel snake-shape vacuum tube with inserted tubes solar collector is designed in this paper, the heat transfer characteristics of the collector are analyzed according to its structural characteristics, and the influence of different working temperature on thermal characteristics of the collector is studied. The solar water heater prototype consisting of 14 vacuum tubes with inserted tubes is prepared, and the hot water storage control subsystem is designed by hysteresis comparison algorithm. The heat characteristic of the prototype was experimentally studied under hot water output temperature of 40-45°C, 50-55°C and 60-65°C. The daily thermal efficiency was 64%, 50% and 46%, respectively. The experimental results are basically consistent with the theoretical analysis.

  3. The dynamic single-tube concept; Le mono-tube dynamique

    Energy Technology Data Exchange (ETDEWEB)

    Rivet, P. [Ste MC International (France)


    In the framework of greenhouse gas emission reduction and the utilization of cooling intermediate fluids with indirect refrigerating systems, a new concept of dynamical single-tube has been developed, which allows for the simultaneous cold distribution from a centralized plant towards various required temperature systems (as for example in a supermarket refrigerating system) with optimized efficiency, fluid flow and defrosting conditions; moreover, the dynamic single-tube concept is very well adapted to two-phase flows

  4. Development and Technology Transfer of the Syncro Blue Tube (Gabriel) Magnetically Guided Feeding Tube (United States)


    placement. Patients who had trauma to the neck that precluded placing the magnet behind the neck and patients with abdominal surgery resulting in...2%), is associated with high mortality rate (50%). Peristalsis will now advance the Gabriel® Feeding Tube into the small intestine. Now advance... high potential for post-pyloric migration without extra skills or costly procedures. The Gabriel feeding tube with balloon was developed with

  5. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening (United States)

    ... Screening Research Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening (PDQ®)–Patient Version What is screening? Go to ... ovarian cancer. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening Key Points Tests are used to screen for ...

  6. Risks of Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening (United States)

    ... Screening Research Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening (PDQ®)–Patient Version What is screening? Go to ... ovarian cancer. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening Key Points Tests are used to screen for ...

  7. Gastrostomy tube feeding of children with cerebral palsy

    DEFF Research Database (Denmark)

    Dahlseng, Magnus O; Andersen, Guro L; DA Graca Andrada, Maria


    To compare the prevalence of gastrostomy tube feeding (GTF) of children with cerebral palsy (CP) in six European countries.......To compare the prevalence of gastrostomy tube feeding (GTF) of children with cerebral palsy (CP) in six European countries....

  8. Brushless dc motor uses electron beam switching tube as commutator (United States)

    Studer, P.


    Electron beam switching tube eliminates physical contact between rotor and stator in brushless dc motor. The tube and associated circuitry control the output of a dc source to sequentially energize the motor stator windings.

  9. Disinfection of Biofilms in Tubes with Ultraviolet Light

    DEFF Research Database (Denmark)

    Bak, Jimmy; Begovic, Tanja


    Bacterial biofilms on long-term catheters are a major source of infection. We demonstrate here the potential of UVC light emitting diodes (LED) for disinfection purposes in catheter like tubes contaminated with biofilm. We show that UVC Light propagation is possible through teflon tubes using...... that the UVC light attenuation inside the tube can be described by an exponential function depending of tube length and various loss mechanisms. The disinfection efficiency of the UVC diodes is demonstrated on tubes contaminated artificially with a Pseudomonas aeruginosa biofilm. The tubes were connected...... the liquid light guiding principle. If the refractive index of the liquid is higher than that of the tube material light is guided inside the tube by internal reflections. To obtain a high refractive index of the liquid sodium chloride in high concentrations is added to the aqueous solution. It is shown...

  10. Helioseismic Effects of Magnetic Flux Tube: 3D Numerical Simulations (United States)

    Daiffallah, K.; Abdelatif, T.


    Observations suggest clearly that there is a significant interaction between solar surface waves and magnetic flux tubes with specific helioseismic signature. Magnetic flux tubes permit the propagation of two types of magnetohydrodynamic waves: The longitudinal tube wave (sausage modes) and the transversal tube wave (kink modes). The response of different magnetic flux tubes embedded in polytropic atmosphere to the propagation of surface gravity wave (f-mode) is studied numerically with the SLiM code (see Cameron et al. 2007). We find that the back scattering wave from different sizes of tubes reveals interesting information about which modes are excited in the tubes. The numerical calculations of the scattering effects (for different frequencies of the incident wave, different tube radius and values of plasma-beta) are compared with theoretical results obtained by Hanasoge et al. 2008.

  11. Glycol/water evacuated-tube solar collector (United States)


    Report describes performance of 8 tube and 10 tube commercially produced solar collectors. Tests include thermal efficiency, time constant for temperature drop after solar flux is cut, change in efficiency with Sun angle, and temperature rise if circulation is stopped.

  12. Split radius-form blocks for tube benders (United States)

    Lange, D. R.; Seiple, C. W.


    Two-piece, radius-form block permits accurate forming and removing of parts with more than a 180 degree bend. Tube bender can shape flexible metal tubing in applications dealing with plumbing, heating, and pressure transmission lines.

  13. Technical note: Development of a gradient tube method for ...

    African Journals Online (AJOL)

    Technical note: Development of a gradient tube method for examining microbial population structures in floating sulphur biofilms. ... parameters within the system. Keywords: gradient tube method, floating biofilms, floating sulphur biofilms, microbial ecology, sulphur biotechnology, acid mine drainage wastewaters ...

  14. Blind vortex tube as heat-rejecting heat exchanger for pulse tube cryocooler (United States)

    Mitchell, M. P.; Fabris, D.; Sweeney, R. O.


    This project integrated several unusual design features in a coaxial pulse tube cooler driven by a G-M compressor. Design objectives were simplification of construction and validation of innovative components to replace screens. The MS*2 Stirling Cycle Code was used to develop the thermodynamic design of the cooler. The primary innovation being investigated is the vortex tube that serves as both the orifice and the heat-rejecting heat exchanger at the warm end of the pulse tube. The regenerator is etched stainless steel foil with a developmental etch pattern. The cold heat exchanger is a copper cup with axial slits in its wall. Flow straightening in the cold end of the pulse tube is accomplished in traditional fashion with screens, but flow in the warm end of the pulse tube passes through a diffuser nozzle that is an extension of the cold throat of the vortex tube. The G-M compressor is rated at 2 kW. The custom-built rotary valve permits operation at speeds up to about 12 Hz. A series of adjustments over a period of about 7 months improved cooling performance by an average of almost 20 K per month. A no-load temperature of 65 K has been achieved. Experimental apparatus and results of this patented device [1,2] are described.

  15. Magnetic resonance imaging of cleft palate

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Yasushi; Tasaka, Yasuyuki; Honjo, Iwao; Nishimura, Kazumasa; Nakano, Yoshihisa


    Magnetic resonance imaging (MRI) of the nasopharynx and the eustachian tube was performed in five patients with cleft palate and compared with the results of those without this anomaly. Various degrees of deformity of the eustachian tube cartilage were found in cleft palate patients. The levator veli palatini muscles were situated more laterally in cleft palate patients than in normal subjects. Also, changes in the position of these muscles after palatoplasty were clearly depicted by MRI. Besides several autopsy reports, this is the first demonstration of the characteristic anomaly around the eustachian tube by a non-invasive method.

  16. Nutritional support via enteral tube feeding in hospital patients. (United States)

    Roberts, Elizabeth

    Patients receiving enteral tube feeding are often encountered in the ward environment of an acute care setting. Patients may receive enteral tube feed through tubes intended for short-term feeding, or they may have a long-term feeding tube in situ. This article aims to provide a practical overview of feeding solutions and administration to enable nursing staff to understand prescribed regimens and provide patients with optimum care.

  17. Percutaneous endoscopic gastrostomy tube replacement: A simple procedure?


    Lohsiriwat, Varut


    Replacement of gastrostomy tube in patients undergoing percutaneous endoscopic gastrostomy (PEG) is generally considered as a safe and simple procedure. However, it could be associated with serious complications, such as gastrocutaneous tract disruption and intraperitoneal tube placement, which may lead to chemical peritonitis and even death. When PEG tube needs a replacement (e.g., occlusion or breakage of the tube), clinicians must realize that the gastrocutaneous tract of PEG is more friab...

  18. Cell Wall Composition, Biosynthesis and Remodeling during Pollen Tube Growth


    Jean-Claude Mollet; Christelle Leroux; Flavien Dardelle; Arnaud Lehner


    The pollen tube is a fast tip-growing cell carrying the two sperm cells to the ovule allowing the double fertilization process and seed setting. To succeed in this process, the spatial and temporal controls of pollen tube growth within the female organ are critical. It requires a massive cell wall deposition to promote fast pollen tube elongation and a tight control of the cell wall remodeling to modify the mechanical properties. In addition, during its journey, the pollen tube interacts with...

  19. Preventing Silicone Tube Extrusion after Nasolacrimal Duct Intubation in Children

    Directory of Open Access Journals (Sweden)

    Ali-Akbar Sabermoghaddam


    Full Text Available Herein we report our experience with a simple technique for reducing the rate of silicone tube extrusion after nasolacrimal duct (NLD intubation for congenital NLD obstruction. Medical records of children older than 2 years, with or without history of failed probing, who had undergone NLD intubation with a Crawford silicone tube over a period of 4 years were reviewed. In all subjects, one end of the Crawford tube was passed through a piece of scalp vein tubing followed by applying one or two knots. All Crawford tubes were removed after 3 months. Main outcome measures included complications such as tube extrusion, nasal discharge, crust formation and pyogenic granuloma formation. Fifty-seven patients, including 49 unilateral and 8 bilateral cases with mean age of 3.8΁1.6 (range, 2 to 11.5 years were operated. No complications such as tube dislodgement, significant nasal discharge, crust or pyogenic granuloma formation occurred prior to Crawford tube removal. All silicone tubes were successfully removed from the nasal cavity. In conclusion, passing one end of the Crawford tube through a small piece of scalp vein tubing before knotting it in the nasal cavity seems to decrease the rate of tube extrusion which is the most common complication following NLD intubation in children.

  20. MoModel study of DC ignition of fluorescent tubes

    NARCIS (Netherlands)

    W.J.M. Brok; M.F. Gendre; J.J.A.M. van der Mullen


    htmlabstractBreakdown in a discharge tube is investigated by means of a fluid model. The discharge tube is similar to a compact fluorescent lamp tube, containing argon at 3 Torr and mercury at a few millitorr. It was found that the minimum breakdown voltage is decreased substantially compared with a

  1. Higher Education Migrates to YouTube and Social Networks (United States)

    Gilroy, Marilyn


    True global enlightenment. That's how YouTubeEDU is being promoted by company officials who have announced the launch of a YouTube section devoted to academic content. Calling the new site "a free, self-organizing, democratic website containing all the world's knowledge," YouTubeEDU promises an environment in which "any qualified teacher can…

  2. YouTube, "Drug Videos" and Drugs Education (United States)

    Manning, Paul


    Aims: This article reports on findings to emerge from a project examining YouTube "drug videos" in the light of an emerging literature on the relationship between YouTube and health education. The aim of this article is to describe the variety of discourses circulated by the "drug videos" available on YouTube and to consider…

  3. 21 CFR 874.3930 - Tympanostomy tube with semipermeable membrane. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tympanostomy tube with semipermeable membrane. 874... Tympanostomy tube with semipermeable membrane. (a) Identification. A tympanostomy tube with a semipermeable membrane is a device intended to be implanted for ventilation or drainage of the middle ear and for...

  4. Dynamical Processes in Flux Tubes and their Role in ...

    Indian Academy of Sciences (India)

    We model the dynamical interaction between magnetic flux tubes and granules in the solar photosphere which leads to the excitation of transverse (kink) and longitudinal (sausage) tube waves. The investigation is motivated by the interpretation of network oscillations in terms of flux tube waves. The calculations show that ...

  5. 21 CFR 868.5280 - Breathing tube support. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing tube support. 868.5280 Section 868.5280...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5280 Breathing tube support. (a) Identification. A breathing tube support is a device that is intended to support and anchor a patient's breathing...

  6. Heat transfer and thermal stress analysis in grooved tubes

    Indian Academy of Sciences (India)

    The maximum thermal stress ratio positions inside the tube have been indicated as MX for all investigated cases. In the light of the thermal stress values, various designs can be applied to reduce thermal stress in grooved tubes. Keywords. Heat transfer; thermal stress; grooved tubes. 1. Introduction. Heat transfer in pipe flow ...

  7. A Novel Device for Accurate Chest Tube Insertion

    DEFF Research Database (Denmark)

    Katballe, Niels; Moeller, Lars B; Olesen, Winnie H


    BACKGROUND: Optimal positioning of a large-bore chest tube is in the part of the pleural cavity that needs drainage. It is recommended that the chest tube be positioned apically in pneumothorax and basally for fluids. However, targeted chest tube positioning to a specific part of the pleural cavity...

  8. Pressure Tests on SG Pulled Tubes at TSP Level (United States)

    Boccanfuso, Marc; Mathon, Cédric

    In 2009, 12 tubes were pulled at the tube support plate level of a Steam Generator at one of France's oldest nuclear power plants. In order to identify the involved mechanisms and to characterise the defects, metallurgical examinations were carried out on these tubes.

  9. Endotracheal tube cuff pressures – the worrying reality: A ...

    African Journals Online (AJOL)

    Secondary aims were to determine whether the tube size, tube make or place of intubation affected cuff pressure. Method. Endotracheal tube cuff pressures of 91 patients in the trauma centre and 100 patients in the theatre complex were randomly measured using a Mallinckrodt cuff pressure gauge. The measurements ...

  10. Miura Tubes and Assemblages: Theory and Applications (United States)

    Filipov, Evgueni; Paulino, Glaucio; Tachi, Tomohiro


    Origami systems inspired from the Miura-ori pattern are rigid and flat foldable meaning that they can fold completely by deforming only about prescribed fold lines. We investigate origami tubes and assemblages constructed from Miura-ori inspired sheets and use eigenvalue analyses to study their stiffness characteristics. A simplified bar model is used to model the stretching and shear of the flat panel segments and rotational hinges are used to simulate the bending stiffness of the panels and prescribed fold lines. We discuss the small to large deformation bending of thin sheets and show an improved method to estimate stiffness when modeling origami structures. The tube assemblages show interesting behaviors that make them suitable for applications in science and engineering.

  11. I Tune, You Tube, We Rule

    Directory of Open Access Journals (Sweden)

    Shida, R. Y.


    Full Text Available The website YouTube was created in 2005 and has rapidly become one ofthe most popular entertainment websites on the internet. It is riding the online video wave today like few other online companies and is currently more popular than the video sections of either Yahoo or Google. iTunes, a digital media application created by Apple in 2001, where one can download and play music and videos, has had a similar success. There is little doubt that they both represent important communication channels in a world heavily influenced by online media, especially among teenagers and young adults. As science communicators we can use this direct route to a younger audience to our advantage. This article aims to give a taste of these applications with a fewselected examples demonstrating that both YouTube and iTunes are excellent tools to teach and inspire the general public.

  12. I Tune, You Tube, We Rule (United States)

    Shida, R. Y.; Gater, W.


    The website YouTube was created in 2005 and has rapidly become one of the most popular entertainment websites on the internet. It is riding the online video wave today like few other online companies and is currently more popular than the video sections of either Yahoo or Google. iTunes, a digital media application created by Apple in 2001, where one can download and play music and videos, has had a similar success. There is little doubt that they both represent important communication channels in a world heavily influenced by online media, especially among teenagers and young adults. As science communicators we can use this direct route to a younger audience to our advantage. This article aims to give a taste of these applications with a few selected examples demonstrating that both YouTube and iTunes are excellent tools to teach and inspire the general public.

  13. Endoscopic placement of enteral feeding tubes. (United States)

    Rafferty, Gerard P; Tham, Tony Ck


    Malnutrition is common in patients with acute and chronic illness. Nutritional management of these malnourished patients is an essential part of healthcare. Enteral feeding is one component of nutritional support. It is the preferred method of nutritional support in patients that are not receiving adequate oral nutrition and have a functioning gastrointestinal tract (GIT). This method of nutritional support has undergone progression over recent times. The method of placement of enteral feeding tubes has evolved due to development of new feeding tubes and endoscopic technology. Enteral feeding can be divided into methods that provide short-term and long-term access to the GIT. This review article focuses on the current range of methods of gaining access to the GIT to provide enteral feed.

  14. Coaxial tube array space transmission line characterization (United States)

    Switzer, Colleen A.; Bents, David J.


    The coaxial tube array tether/transmission line used to connect an SP-100 nuclear power system to the space station was characterized over the range of reactor-to-platform separation distances of 1 to 10 km. Characterization was done with respect to array performance, physical dimensions and masses. Using a fixed design procedure, a family of designs was generated for the same power level (300 kWe), power loss (1.5 percent), and meteoroid survival probability (99.5 percent over 10 yr). To differentiate between vacuum insulated and gas insulated lines, two different maximum values of the E field were considered: 20 kV/cm (appropriate to vacuum insulation) and 50 kV/cm (compressed SF6). Core conductor, tube, bumper, standoff, spacer and bumper support dimensions, and masses were also calculated. The results of the characterization show mainly how transmission line size and mass scale with reactor-to-platform separation distance.

  15. Enhanced bulk polysilicon production using silicon tubes (United States)

    Jafri, Ijaz; Chandra, Mohan; Zhang, Hui; Prasad, Vish; Reddy, Chandra; Amato-Wierda, Carmela; Landry, Marc; Ciszek, Ted


    A novel technique using silicon tubes for the production of bulk polysilicon via chemical vapor deposition is presented. Our experimental studies with a model reactor indicate that the polysilicon growth inside the silicon tube (15.3 g) exceeds that of the calculated polysilicon growth on silicon slim rods (4.3 g) over 55 h of deposition time. A computational model is also being developed to simulate the growth rates of the model reactor. Preliminary computational results from this model show a slightly asymmetric temperature distribution at the reactor center line with a 1000 sccm argon flow at 850°C reactor temperature. Both these experimental and computational modeling studies have identified key criteria for the prototype reactor being designed for bulk polysilicon growth.

  16. Clean Industrial Room for Drift Tube Assembling

    CERN Document Server

    Glonti, GL; Evtoukhovitch, P G; Kroa, G; Manz, A; Potrap, I N; Rihter, P; Stoletov, G D; Tskhadadze, E G; Chepurnov, V F; Chirkov, A V; Shelkov, G A


    Description of a clean industrial room for assembly of drift tubes for the muon spectrometer of the ATLAS experiment is presented. High quality specifications on the detectors to be produced demanded creation of a workplace with stable temperature and humidity, as well as minimum quantity of dust in the room. Checking of parameters of intra-room air during long period of continuous work has been confirmed correctness of the designed characteristics of the climatic system installed in the clean room. The room large volum (\\sim 190 m^3), the powerful and flexible climatic system, and simplicity of service allow assembling of detectors with length up to 5 m. Subsequent checking of functionality of the assembled detectors has shown high quality of assembling (the amount of rejected tubes does not exceed 2 %). It demonstrates conformity to the assembling quality requirements for mass production of drift chambers for the muon spectrometer.


    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Harper, Ph.D.


    Work continued on three major tasks of this project--increasing the circumferential strength of MA956 tubing, joining of the MA956 alloy, and determination of the high temperature corrosion limits of the MA956 alloy. With respect to increasing the circumferential strength of a MA956 tube, all of the cold working operations (0, 10, 20, 30, 40%) and annealing treatments (1000, 1150, 1300 C) have been completed. The sample microstructures produced by this processing continue to be analyzed with TEM results providing valuable information on the strengthening mechanism of this alloy. Creep testing to determine the ''stress threshold'' curves for this alloy continues. Regarding joining of the MA956 alloy, additional welds were produced with the friction welding and transient liquid phase bonding techniques. And finally, laboratory high temperature corrosion testing of the material continues in both fluid-side and fire-side simulated environments.

  18. Plugging criteria for WWER SG tubes

    Energy Technology Data Exchange (ETDEWEB)

    Papp, L.; Wilam, M. [Vitkovice NPP Services (Switzerland); Herman, M. [Vuje, Trnava (Slovakia)


    At operated Czech and Slovak nuclear power plants the 80 % criteria for crack or other bulk defect depth is used for steam generator heat exchanging tubes plugging. This criteria was accepted as the recommendation of designer of WWER steam generators. Verification of this criteria was the objective of experimental program performed by Vitkovice, J.S.C., UJV Rez, J.S.C. and Vuje Trnava, J.S.C .. Within this program the following factors were studied: (1) Influence of secondary water chemistry on defects initiation and propagation, (2) Statistical evaluation of corrosion defects progression at operated SG, and (3) Determination of critical pressure for tube rupture as a function of eddy current indications. In this presentation items (2) and (3) are considered.

  19. YouTube Extension of Music Memory

    Directory of Open Access Journals (Sweden)

    Trena Jordanoska


    Full Text Available Individual work approach to collective cultural memory is marked by unprecedented digital tool – Internet. Social networks accelerated the exchange of music artifacts to extremely large numbers of participants. One of the important aspects of the new digital transition is that the improved transfer rates resulted in an audio quality approaching the limits of human hearing. YouTube counter is undoubtedly the best indicator for the presence of these artifacts in virtual reality. The records of the downloads of the “Gangnam Style” song in billion, support the argument for the influence of the new technological means on collective memory. In our research we collected and analyzed the data regarding music posting on YouTube.

  20. Premixed flame propagation in vertical tubes

    CERN Document Server

    Kazakov, Kirill A


    Analytical treatment of premixed flame propagation in vertical tubes with smooth walls is given. Using the on-shell flame description, equations describing quasi-steady flame with a small but finite front thickness are obtained and solved numerically. It is found that near the limits of inflammability, solutions describing upward flame propagation come in pairs having close propagation speeds, and that the effect of gravity is to reverse the burnt gas velocity profile generated by the flame. On the basis of these results, a theory of partial flame propagation driven by the gravitational field is developed. A complete explanation is given of the intricate observed behavior of limit flames, including dependence of the inflammability range on the size of the combustion domain, the large distances of partial flame propagation, and the progression of flame extinction. The role of the finite front-thickness effects is discussed in detail. Also, various mechanisms governing flame acceleration in smooth tubes are ide...

  1. Shock Tube as an Impulsive Application Device

    Directory of Open Access Journals (Sweden)

    Soumya Ranjan Nanda


    Full Text Available Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

  2. Source Terms for HFIR Beam Tube Shielding Analyses, and a Complete Shielding Analysis of the HB-3 Tube

    Energy Technology Data Exchange (ETDEWEB)

    Bucholz, J.A.


    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory is in the midst of a massive upgrade program to enhance experimental facilities. The reactor presently has four horizontal experimental beam tubes, all of which will be replaced or redesigned. The HB-2 beam tube will be enlarged to support more guide tubes, while the HB-4 beam tube will soon include a cold neutron source.

  3. On the generation of flux tube waves in stellar convection zones. I - Longitudinal tube waves driven by external turbulence (United States)

    Musielak, Z. E.; Rosner, R.; Ulmschneider, P.


    The source functions and the energy fluxes for wave generation in magnetic flux tubes embedded in an otherwise magnetic field-free, turbulent, and compressible fluid are derived. The calculations presented here assume that the tube interior is not itself turbulent, e.g., that motions within the flux tube are due simply to external excitation. Specific results for the generation of longitudinal tube waves are presented.

  4. A Tube Model of Rubber Elasticity


    Kutter, S.; Terentjev, E. M.


    Polymer entanglements lead to complicated topological constraints and interactions between neighbouring chains in a dense solution or melt. Entanglements can be treated in a mean field approach, within the famous reptation model, since they effectively confine each individual chain in a tube-like geometry. In polymer networks, due to crosslinks preventing the reptation constraint release, entanglements acquire a different topological meaning and have a much stronger effect on the resulting me...

  5. High Power Microwave Tube Reliability Study (United States)


    into the pro- gram which is used when the failure data are incomplete, i.e. contains some censored tubes. This test is due to Gnedenko, et al. and is...United States Air Force, "’Inspectiort Systeia, Documentation, and Reporting for Ground Comunications -Electronics-Meteorological (CEM) Equipment," TO...00-20-8, June 1974. 2. Gnedenko, B., et al. Mathemtical Models of Reliablity Theory, Academic Press, New York, 1>69. 3. Mann, Nancy R., Ray E. Shafer

  6. YouTube and Video Quizzes (United States)

    Yee, Kevin; Hargis, Jace


    The Internet sensation YouTube ( has become such a force online that it was estimated in 2006 to account for a full tenth of the bandwidth by the entire Internet in the United States (WebProNews, 2007), and to use as much bandwidth in 2007 as the entire Internet had done in 2000 (Carter, 2008). Like many technological tools…

  7. Dynamics of miscible displacements in round tubes

    Energy Technology Data Exchange (ETDEWEB)

    Meiburg, E.; Maxworthy, T.; Chen, C.Y. [Univ. of Southern California, Los Angeles, CA (United States); Petitjeans, P. [Ecole Superieure de Physique et de Chimie Industrielles, Paris (France)


    A combined experimental and numerical investigation of miscible two-phase flow in a capillary tube is reported. The fraction of fluid left behind on the wall is obtained as a function of the Peclet, Atwood, and Froude numbers. Scaling arguments are presented for two distinct flow regimes, dominated by diffusion and convection, respectively. In the latter one, an effective surface tension value can be estimated.

  8. [Laryngeal tube II : alternative airway for children?]. (United States)

    Schalk, R; Scheller, B; Peter, N; Rosskopf, W; Byhahn, C; Zacharowski, K; Meininger, D


    Difficult airway situations both expected and unexpected, present major challenges to every anesthesiologist, especially in pediatric anesthesia. However, the integration of extraglottic airway devices, such as the laryngeal mask, into the algorithm of difficult airways has improved the handling of difficult airway situations. A device for establishing a supraglottic airway, the laryngeal tube (LT), was introduced in 1999. The LT is an extraglottic airway designed to secure a patent airway during either spontaneous breathing or controlled ventilation. The design of the device has been revised several times and a further development is the LTS II/LTS-D, which provides an additional channel for the insertion of a gastric drain tube. This article reports on the successful use of the LTS II in 12 children aged from 2 days to 6 years when endotracheal intubation, alternative mask or laryngeal mask ventilation failed. Use of the LTS II was associated with a high level of success, securing the airway when other techniques had failed. The potential advantage of the LTS II over the standard LT is an additional suction port, which allows gastric tube placement and can be used as an indirect indicator of correct placement. With a modified insertion technique using an Esmarch manoeuvre, placement was simple and fast to perform. In emergency situations when direct laryngoscopy fails or is too time-consuming the LTS II tube is recommended as an alternative device to secure the airway. As with all extraglottic airway devices, familiarity and clinical experience with the respective device and the corresponding insertion technique are essential for safe and successful use, especially in emergency situations.

  9. Radioactive fallout and neural tube defects

    Directory of Open Access Journals (Sweden)

    Nejat Akar


    Full Text Available Possible link between radioactivity and the occurrence of neural tube defects is a long lasting debate since the Chernobyl nuclear fallout in 1986. A recent report on the incidence of neural defects in the west coast of USA, following Fukushima disaster, brought another evidence for effect of radioactive fallout on the occurrence of NTD’s. Here a literature review was performed focusing on this special subject.

  10. Accidental Perforation of Submental Flexometallic Tube


    Sundaram, Subbulakshmi; Ramdas, Gowthaman; Paul, Anisha Pauline; Krishnasamy, Sekaran Natesan


    Oral and maxillofacial surgeries associated with complications due to endotracheal tube (ETT) damage are being reported in literature increasingly. In this case, we report a rare case of accidental perforation of a flexometallic ETT intraoperatively during an orthognathic corrective surgery, in a 19-year-old female patient in whom submental intubation had been performed. The complication was managed conservatively as the tissue debris created during the osteotomy drilling occluded the damage ...

  11. Heat Transfer Analysis of Fin Tube

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Woo-Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Choi, Cheng-Ryul [ELSOLTEC Co., Yongin (Korea, Republic of)


    This paper describes a preliminary numerical analysis of fin tube used for a heat exchanger of the air-water cooling system. The internal flow in a fin tube is steam and the external of the fin is cooled by air. Cooling system in a nuclear power plant can be divided into two categories; 1) active pump driven system powered by alternating current and 2) passive cooling system drived by natural circulation phenomena. After the accident in Hukushima Nuclear Power Plants, the importance of the passive cooling system that can provide a long-term cooling of reactor decay heat during station blackout condition is emphasized. However, the effectiveness of passive cooling system based on cooling water is limited by the capacity of water storage tank. To overcome the limit due to the exhaustion of the cooling water, an natural convection air cooling system is proposed. As the air operated cooling system utilizes natural circulation phenomena of air, it does not require cooling water. However, the heat transfer area of the air operated cooling system should be increased much as the heat removal capacity per unit area is much lower than that of water cooling system. The air-water combined cooling system can resolve this excess increase of the heat transfer area in the air operated cooling system. This air-water cooling system can be also used in the passive containment cooling system. The effect of design parameters such as fin tube arrangement, the fin height, and pitch has been analyzed and the chimney effect on the simulation of heat transfer in a heat exchanger is evaluated. The internal flows in a fin tube heat exchanger for natural circulation flow condition and forced convection (suction) condition were investigated.

  12. Neural Tube Defects, Folic Acid and Methylation (United States)

    Imbard, Apolline; Benoist, Jean-François; Blom, Henk J.


    Neural tube defects (NTDs) are common complex congenital malformations resulting from failure of the neural tube closure during embryogenesis. It is established that folic acid supplementation decreases the prevalence of NTDs, which has led to national public health policies regarding folic acid. To date, animal studies have not provided sufficient information to establish the metabolic and/or genomic mechanism(s) underlying human folic acid responsiveness in NTDs. However, several lines of evidence suggest that not only folates but also choline, B12 and methylation metabolisms are involved in NTDs. Decreased B12 vitamin and increased total choline or homocysteine in maternal blood have been shown to be associated with increased NTDs risk. Several polymorphisms of genes involved in these pathways have also been implicated in risk of development of NTDs. This raises the question whether supplementation with B12 vitamin, betaine or other methylation donors in addition to folic acid periconceptional supplementation will further reduce NTD risk. The objective of this article is to review the role of methylation metabolism in the onset of neural tube defects. PMID:24048206

  13. Neural Tube Defects, Folic Acid and Methylation

    Directory of Open Access Journals (Sweden)

    Henk J. Blom


    Full Text Available Neural tube defects (NTDs are common complex congenital malformations resulting from failure of the neural tube closure during embryogenesis. It is established that folic acid supplementation decreases the prevalence of NTDs, which has led to national public health policies regarding folic acid. To date, animal studies have not provided sufficient information to establish the metabolic and/or genomic mechanism(s underlying human folic acid responsiveness in NTDs. However, several lines of evidence suggest that not only folates but also choline, B12 and methylation metabolisms are involved in NTDs. Decreased B12 vitamin and increased total choline or homocysteine in maternal blood have been shown to be associated with increased NTDs risk. Several polymorphisms of genes involved in these pathways have also been implicated in risk of development of NTDs. This raises the question whether supplementation with B12 vitamin, betaine or other methylation donors in addition to folic acid periconceptional supplementation will further reduce NTD risk. The objective of this article is to review the role of methylation metabolism in the onset of neural tube defects.

  14. Reference factor F{sub (CT)Q} and X ray tube ionization yield R{sub (TUBE)Q}

    Energy Technology Data Exchange (ETDEWEB)

    Quaresma, D.S. [Observatorio Nacional, Rio de Janeiro, RJ (Brazil); Cardoso, R.S.; Peixoto, J.G.P., E-mail: [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)


    The operational facility procedures in diagnostic radiology standardization and calibration, through the relation between the X ray tube current and the ionization chamber current in a radiation quality Q, shown the reference factor F{sub (CT)Q} as the reality estimate to the X ray tube ionization yield, R{sub (TUBE)Q} . (author)

  15. Influence of the connecting tube at the cold end in a U-shaped pulse tube cryocooler (United States)

    Hu, J. Y.; Zhang, X. Z.; Wang, X. T.; Luo, E. C.; Dai, W.


    In some special applications, the pulse tube cryocooler must be designed as U-shape; however, the connecting tube at the cold end will influence the cooling performance. Although lots of U-shape pulse tubes have been developed, the mechanism of the influence of the connecting tube on the performance has not been well demonstrated. Based on thermoacoustic theory, this paper discusses the influence of the length and diameter of the connecting tube, transition structure, flow straightener, impedance of the inertance tube, etc. on the cooling performance. Primary experiments were carried out in two in-line shape pulse tube cryocoolers to verify the analysis. The two cryocoolers shared the same regenerator, heat exchangers, inertance tube and straightener, and the pulse tube, so the influence of these components could be eliminated. With the same electric power, the pulse tube cryocooler without connecting parts obtained 31 W cooling power at 77 K; meanwhile, the other pulse tube cryocooler with the connecting parts only obtained 27 W, so the connecting tube induced more than a 12.9% decrease on the cooling performance, which agrees with the calculation quite well.

  16. Tension Pneumothorax and Subcutaneous Emphysema Complicating Insertion of Nasogastric Tube

    Directory of Open Access Journals (Sweden)

    Narjis AL Saif


    Full Text Available Nasogastric tube has a key role in the management of substantial number of hospitalized patients particularly the critically ill. In spite of the apparent simple insertion technique, nasogastric tube placement has its serious perhaps fatal complications which need to be carefully assessed. Pulmonary misplacement and associated complications are commonplace during nasogastric tube procedure. We present a case of tension pneumothorax and massive surgical emphysema in critically ill ventilated patient due to inadvertent nasogastric tube insertion and also discussed the risk factors, complication list, and arrays of techniques for safer tube placement.

  17. Sealing Out-Of-Round Tubes With O-Rings (United States)

    Shlichta, Paul J.


    Glass or ceramic tubes out-of-round sealed effectively by ordinary O-rings in caps of modified hydraulic fittings. In typical connection, O-ring squeezed between two surfaces having inward-opening slants of 5 degrees or 10 degrees. Slanted surfaces force ring inward, compressing it around tube. Connector metal fitting, tightened by hand around O-ring, seals O-ring against tube as much as 1/16 in. out of round. Modified connectors seal glass or ceramic tubes against gas or vacuum leakage in furnaces, vacuum systems, and tubes for glassblowing equipment.

  18. Nervous system examination on YouTube

    Directory of Open Access Journals (Sweden)

    Azer Samy A


    Full Text Available Abstract Background Web 2.0 sites such as YouTube have become a useful resource for knowledge and are used by medical students as a learning resource. This study aimed at assessing videos covering the nervous system examination on YouTube. Methods A research of YouTube was conducted from 2 November to 2 December 2011 using the following key words “nervous system examination”, “nervous system clinical examination”, “cranial nerves examination”, “CNS examination”, “examination of cerebellum”, “balance and coordination examination”. Only relevant videos in the English language were identified and related URL recorded. For each video, the following information was collected: title, author/s, duration, number of viewers, number of posted comments, and total number of days on YouTube. Using criteria comprising content, technical authority and pedagogy parameters, videos were rated independently by three assessors and grouped into educationally useful and non-educationally useful. Results A total of 2240 videos were screened; 129 were found to have relevant information to nervous system examination. Analysis revealed that 61 (47% of the videos provided useful information on the nervous system examination. These videos scored (mean ± SD, 14.9 ± 0.2 and mainly covered examination of the whole nervous system (8 videos, 13%, cranial nerves (42 videos, 69%, upper limbs (6 videos, 10%, lower limbs (3 videos, 5%, balance and co-ordination (2 videos, 3%. The other 68 (53% videos were not useful educationally; scoring (mean ± SD, 11.1 ± 3.0. The total viewers of all videos was 2,189,434. Useful videos were viewed by 1,050,445 viewers (48% of total viewers. The total viewership per day for useful videos was 1,794.5 and for non-useful videos 1,132.0. The differences between the three assessors were insignificant (less than 0.5 for the mean and 0.3 for the SD. Conclusions Currently, YouTube provides an adequate resource

  19. Nervous system examination on YouTube (United States)


    Background Web 2.0 sites such as YouTube have become a useful resource for knowledge and are used by medical students as a learning resource. This study aimed at assessing videos covering the nervous system examination on YouTube. Methods A research of YouTube was conducted from 2 November to 2 December 2011 using the following key words “nervous system examination”, “nervous system clinical examination”, “cranial nerves examination”, “CNS examination”, “examination of cerebellum”, “balance and coordination examination”. Only relevant videos in the English language were identified and related URL recorded. For each video, the following information was collected: title, author/s, duration, number of viewers, number of posted comments, and total number of days on YouTube. Using criteria comprising content, technical authority and pedagogy parameters, videos were rated independently by three assessors and grouped into educationally useful and non-educationally useful. Results A total of 2240 videos were screened; 129 were found to have relevant information to nervous system examination. Analysis revealed that 61 (47%) of the videos provided useful information on the nervous system examination. These videos scored (mean ± SD, 14.9 ± 0.2) and mainly covered examination of the whole nervous system (8 videos, 13%), cranial nerves (42 videos, 69%), upper limbs (6 videos, 10%), lower limbs (3 videos, 5%), balance and co-ordination (2 videos, 3%). The other 68 (53%) videos were not useful educationally; scoring (mean ± SD, 11.1 ± 3.0). The total viewers of all videos was 2,189,434. Useful videos were viewed by 1,050,445 viewers (48% of total viewers). The total viewership per day for useful videos was 1,794.5 and for non-useful videos 1,132.0. The differences between the three assessors were insignificant (less than 0.5 for the mean and 0.3 for the SD). Conclusions Currently, YouTube provides an adequate resource for learning

  20. Stop Smoking—Tube-In-Tube Helical System for Flameless Calcination of Minerals

    Directory of Open Access Journals (Sweden)

    Nils Haneklaus


    Full Text Available Mineral calcination worldwide accounts for some 5–10% of all anthropogenic carbon dioxide (CO2 emissions per year. Roughly half of the CO2 released results from burning fossil fuels for heat generation, while the other half is a product of the calcination reaction itself. Traditionally, the fuel combustion process and the calcination reaction take place together to enhance heat transfer. Systems have been proposed that separate fuel combustion and calcination to allow for the sequestration of pure CO2 from the calcination reaction for later storage/use and capture of the combustion gases. This work presents a new tube-in-tube helical system for the calcination of minerals that can use different heat transfer fluids (HTFs, employed or foreseen in concentrated solar power (CSP plants. The system is labeled ‘flameless’ since the HTF can be heated by other means than burning fossil fuels. If CSP or high-temperature nuclear reactors are used, direct CO2 emissions can be divided in half. The technical feasibility of the system has been accessed with a brief parametric study here. The results suggest that the introduced system is technically feasible given the parameters (total heat transfer coefficients, mass- and volume flows, outer tube friction factors, and –Nusselt numbers that are examined. Further experimental work will be required to better understand the performance of the tube-in-tube helical system for the flameless calcination of minerals.

  1. The efficacy of feeding tubes: confirmation and loss. (United States)

    Taylor, Stephen J; McWilliam, Helen; Allan, Kaylee; Hocking, Paul

    Around 5% of hospital patients require enteral tube feeding, yet its efficacy and costs are poorly understood. The authors examined radio-opacity, reason for repeat X-ray and overall cost in consecutive patients having tubes confirmed by X-ray when using polyvinylchloride (PVC) Ryles tubes versus CORFLO® (CORTRAK Medsystems) polyurethane tubes (PUTs); and confirmation method and reason for tube loss over an enteral episode. Despite higher PUT cost, because more Ryles tubes required re-X-ray ± radio-contrast injection (0% compared with 26%, p=0.029), overall cost was almost identical (Corflo: £54.2 vs Ryles: £54.6). Confirmation of tube position by X-ray remains more common than pH (51% compared with 45%) and tube loss is mostly as a result of inadvertent patient removal (54%). These studies show that: a) when using X-ray confirmation, PUTs and PVC Ryles tube cost is similar; b) despite pH being taught as first-line confirmation, X-ray remains the most common method therefore PUT use may further reduce cost when staff and outcome costs are included. In addition, more reliable and repeatable bedside confirmation methods are required; c) most tube loss is potentially preventable by use of nasal bridles. Larger studies are required to establish baseline data on problems and cost-effectiveness of enteral tube feeding before intervention trials.

  2. A novel investigation of heat transfer characteristics in rifled tubes (United States)

    Jegan, C. Dhayananth; Azhagesan, N.


    The experimental investigation of heat transfer of water flowing in a rifled tube was explored at different pressures and at various operating conditions in a rifled tube heat exchanger. The specifications for the inner and outer diameters of the inner tube are 25.8 and 50.6 mm, respectively. The working fluids used in shell side and tube side are cold and hot water. The rifled tube was made of the stainless steel with 4 ribs, 50.6 mm outer diameter, 0.775 mm rib height, 58o helix angle and the length 1500 mm. The effect of pressure, wall heat flux and friction factor were discussed. The results confirm that even at low pressures the rifled tubes has an obvious enhancement in heat transfer compared with smooth tube. Results depicts that the Nusselt number increases with Reynolds number and the friction factor decreases with increase in Reynolds number and the heat transfer rate is higher for the rifled tube when compared to smooth tube, because of strong swirl flow due to centrifugal action. It also confirms that, the friction factor obtained from the rifled tube is significantly higher than that of smooth tube.

  3. Experimental approach on the collapse mechanism of CFRP composite tubes (United States)

    Kim, Y. N.; Im, K. H.; Park, J. W.; Yang, I. Y.


    This study is to investigate the energy absorption characteristics of CFRP(Carbon-Fiber Reinforced Plastics) tubes on static and dynamic tests. Axial static compression tests have been carried out using the static testing machine(Shin-gang buckling testing machine) and dynamic compression tests have been utilized using an vertical crushing testing machine. When such tubes are subjected to crushing loads, the response is complex and depends on the interaction between the different mechanisms that could control the crushing process. The collapse characteristics and energy absorption have been examined for various tubes. Energy absorption of the tubes are increased as changes in the lay-up which may increase the modulus of tubes. The results have been varied significantly as a function of ply orientation and interlaminar number. In general, the stacking sequence [0/90] CFRP tubes absorbed more energy than the [15/-15] CFRP tubes.

  4. Quasistatic Modeling of Concentric Tube Robots with External Loads. (United States)

    Lock, Jesse; Laing, Genevieve; Mahvash, Mohsen; Dupont, Pierre E


    Concentric tube robots are a subset of continuum robots constructed by combining pre-curved elastic tubes. As the tubes are rotated and translated with respect to each other, their curvatures interact elastically, enabling control of the robot's tip configuration as well as the curvature along its length. This technology is projected to be useful in many types of minimally invasive medical procedures. Because these robots are flexible by design, they deflect considerably when applying forces to the external environment. Thus, in contrast to rigid-link robots, their kinematic and static force models are coupled. This paper derives a multi-tube quasistatic model that relates tube rotations and translations together with externally applied loads to robot shape and tip configuration. The model can be applied in robot design, procedure planning as well as control. For validation, the multi-tube model is compared experimentally to a computationally-efficient single-tube approximate model.

  5. Integrating YouTube into the nursing curriculum. (United States)

    Sharoff, Leighsa


    Nurse educators need to be innovative, stimulating, and engaging as they teach future nursing professionals. The use of YouTube in nursing education classes provides an easy, innovative, and user-friendly way to engage today's nursing students. YouTube presentations can be easily adapted into nursing courses at any level, be it a fundamentals course for undergraduate students or a theoretical foundations course for graduate students. In this article I will provide information to help educators effectively integrate YouTube into their course offerings. I will start by reviewing the phenomenon of social networking. Next I will discuss challenges and strategies related to YouTube learning experiences, after which I will share some of the legal considerations in using YouTube. I will conclude by describing how to engage students via YouTube and current research related to YouTube.

  6. Simulation of Thermodynamics Aspects about Pulse Tube Refrigerator (United States)

    Hozumi, Yoshikazu; Shiraishi, Masao; Murakami, Masahide


    In order to investigate the heat transfer mechanism inside a pulse tube refrigerator, CFD has been applied to simulate the working gas behavior. Three dimensional compressible Navier-Stokes equations with viscous dissipation have been solved. Heat conduction between the working gas and the tube metal solids are incorporated into the simulation. A Stirling cycle refrigerator has been also simulated to validate the heat transfer mechanism of the pulse tube refrigerator. However, there is a distinctive heat transfer from the cold end to the hot end of pulse tube, the pulse tube works as a gas displacer to induce a phase shift. The heat transfer of pulse tube refrigerator is caused by the same mechanism of Stirling cycle refrigerator. Additionally, thermal convection at an inclined pulse tube on the angle less than horizontal installation is investigated to show simulation capability of the three dimensional modeling.

  7. Preanalytical management: serum vacuum tubes validation for routine clinical chemistry. (United States)

    Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Picheth, Geraldo; Guidi, Gian Cesare


    The validation process is essential in accredited clinical laboratories. Aim of this study was to validate five kinds of serum vacuum tubes for routine clinical chemistry laboratory testing. Blood specimens from 100 volunteers in five different serum vacuum tubes (Tube I: VACUETTE, Tube II: LABOR IMPORT, Tube III: S-Monovette, Tube IV: SST and Tube V: SST II) were collected by a single, expert phlebotomist. The routine clinical chemistry tests were analyzed on cobas 6000 module. The significance of the differences between samples was assessed by paired Student's t-test after checking for normality. The level of statistical significance was set at P < 0.005. Finally, the biases from Tube I, Tube II, Tube III, Tube IV and Tube V were compared with the current desirable quality specifications for bias (B), derived from biological variation. Basically, our validation will permit the laboratory or hospital managers to select the brand's vacuum tubes validated according him/her technical or economical reasons, in order to perform the following laboratory tests: glucose, total cholesterol, high density lipoprotein-cholesterol, triglycerides, total protein, albumin, blood urea nitrogen, uric acid, alkaline phosphatise, aspartate aminotransferase, gamma-glutamyltransferase, lactate dehydrogenase, creatine kinase, total bilirubin, direct bilirubin, calcium, iron, sodium and potassium. On the contrary special attention will be required if the laboratory already performs creatinine, amylase, phosphate and magnesium determinations and the quality laboratory manager intend to change the serum tubes. We suggest that laboratory management should both standardize the procedures and frequently evaluate the quality of in vitro diagnostic devices.

  8. Pulsatile flow through a tube containing rigid and distensible sections. [Artery prosthetic tubing

    Energy Technology Data Exchange (ETDEWEB)

    Daly, B.J.


    It is common surgical pactice to replace or bypass defective sections of artery with prosthetic tubing that is stiffer than the natural artery. This abrupt variation in elasticity produces distortions of the adjacent flow field that could contribute to the failure of connective sutures or the dislodgement of thrombi, resulting in embolisms downstream. However, by the proper choice of prosthesis diameter one should be able to minimize these adverse effects. A numerical technique has been developed to study the pulsatile flow of blood from a natural artery into a rigid tube of arbitrary diameter. This method is used to investigate the effects of variations in rigid tube diameter on the flow development at the juncture with the distensible artery. The computation procedure is an extension of the arbitrary lagrangian eulerian (ALE) method.

  9. Possible lava tube system in a hummocky lava flow at Daund ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The roof of the lava tube has collapsed but original lava tube walls and fragments of the tube roof are seen at ... red bole. At places, the bole is green in colour. The ..... tube roof (figure 3c). Alternatively, these fragments may also represent tumulus crust, roofed over the tube. The petrography of the tube wall layers also pro-.

  10. Going down the tubes! Impact on seizure control of antiepileptic medication given via percutaneous feeding tubes. (United States)

    Jory, Caryn; Shankar, Rohit; Oak, Katy; Oates, Janina; Wilcock, Mike


    Long-term feeding by percutaneous endoscopic gastrostomy tube (PEG) is uncommon but can present significant issues when both nutrition and medication have to be fed down the same tube. This is especially important in people with epilepsy where the dose and bioavailability of antiepileptic drugs are critical to maintain adequate seizure control. This group with long-term PEG tubes is particularly vulnerable and dependent on their carers to provide high standard of care. Indeed, approximately half of the people with long-term feeding tubes suffer from severe intellectual disability which requires careful coordination of all members of the multidisciplinary team. It is all the more important when consideration is given that around 50% of people with severe ID have seizures, mostly treatment resistant. A detailed literature review was conducted with the focus on the numerous factors that can affect medication delivery and absorption with the potential to destabilize seizure control in people with PEG. Issues concerning the site of drug absorption, excipients and dilution, interaction between antiepileptic drugs and the nutritional feed, bioavailability, and problems with the PEG tube are considered. There is limited research in this area and the studies are often based on small numbers, healthy volunteers or in vitro findings. In the absence of sound research data, seizure control in each patient with a PEG needs to be considered on an individual basis. Establishing a baseline by measuring the serum levels prior to the tube insertion may be helpful, followed by checking the levels after PEG insertion. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Falling film evaporation on a tube bundle with plain and enhanced tubes

    Energy Technology Data Exchange (ETDEWEB)

    Habert, M.


    The complexities of two-phase flow and evaporation on a tube bundle present important problems in the design of heat exchangers and the understanding of the physical phenomena taking place. The development of structured surfaces to enhance boiling heat transfer and thus reduce the size of evaporators adds another level of complexity to the modeling of such heat exchangers. Horizontal falling film evaporators have the potential to be widely used in large refrigeration systems and heat pumps, in the petrochemical industry and for sea water desalination units, but there is a need to improve the understanding of falling film evaporation mechanisms to provide accurate thermal design methods. The characterization of the effect of enhanced surfaces on the boiling phenomena occurring in falling film evaporators is thus expected to increase and optimize the performance of a tube bundle. In this work, the existing LTCM falling film facility was modified and instrumented to perform falling film evaporation measurements on single tube row and a small tube bundle. Four types of tubes were tested including: a plain tube, an enhanced condensing tube (Gewa-C+LW) and two enhanced boiling tubes (Turbo-EDE2 and Gewa-B4) to extend the existing database. The current investigation includes results for two refrigerants, R134a and R236fa, at a saturation temperature of T{sub sat} = 5 °C, liquid film Reynolds numbers ranging from 0 to 3000, at heat fluxes between 20 and 60 kW/m² in pool boiling and falling film configurations. Measurements of the local heat transfer coefficient were obtained and utilized to improve the current prediction methods. Finally, the understanding of the physical phenomena governing the falling film evaporation of liquid refrigerants has been improved. Furthermore, a method for predicting the onset of dry patch formation has been developed and a local heat transfer prediction method for falling film evaporation based on a large experimental database has been

  12. An adapted essay tube as the Kundt s Tube used to measure the speed of sound


    Saab, Sérgio da Costa; UEPG - Paraná; Cássaro, Fábio Augusto Meira; UEPG - Paraná; Brinatti, André Maurício; UEPG - Paraná


    One of the main difficulties in high school teaching is the lack of an elementary infra structure to perform any experimental lecture related to Physics. This article presents a simple experiment, suggested to high school teachers, to measure the speed of sound using an adapted essay tube to operate as a Kundt´s tube. The use of the proposed experimental set-up permitted to determine a value to the speed of sound very close to that found in literature. Finally, the experimental...

  13. Evaluation of the Effect of Tube Pitch and Surface Alterations on Temperature Field at Sprinkled Tube Bundle

    Directory of Open Access Journals (Sweden)

    Kracík Petr


    Full Text Available Water flowing on a sprinkled tube bundle forms three basic modes: It is the Droplet mode (liquid drips from one tube to another, the Jet mode (with an increasing flow rate droplets merge into a column and the Membrane (Sheet mode (with further increasing of falling film liquid flow rate columns merge and create sheets between the tubes. With sufficient flow rate sheets merge at this state and the tube bundle is completely covered by a thin liquid film. There are several factors influencing the individual mode types as well as heat transfer. Beside the above mentioned falling film liquid flow rate they are for instance tube diameters, tube pitches in a tube bundle or a physical condition of a falling film liquid. This paper presents a summary of data measured at atmospheric pressure at a tube bundle consisting of copper tubes of 12 milimeters diameter and of the studied tube length one meter. The tubes are positioned horizontally one above another with the tested pitches of 15, 20, 25 and 30 mm and there is a distribution tube placed above them with water flowing out. The thermal gradient of 15–40 has been tested with all pitches where the falling film liquid’s temperature at the inlet of the distribution tube was 15 °C. The liquid was heated during the flow through the exchanger and the temperature of the sprinkled (heater liquid at the inlet of the exchanger with a constant flow rate about 7.2 litres per minute was 40 °C. The tested flow of the falling film liquid ranged from 1.0 to 13.0 litres per minute. Sequences of 180 exposures have been recorded in partial flow rate stages by thermographic camera with record frequency of 30 Hz which were consequently assessed using the Matlab programme. This paper presents results achieved at the above mentioned pitches and at three types of tube bundle surfaces.

  14. Hideout in steam generator tube deposits

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, P.V.; Franklin, K.J.; Turner, C.W


    Hideout in deposits on steam generator tubes was studied using tubes coated with magnetite. Hideout from sodium chloride solutions at 279 degrees C was followed using an on-line high-temperature conductivity probe, as well as by chemical analysis of solution samples from the autoclave in which the studies were done. Significant hideout was observed only at a heat flux greater than 200 kW/m{sup 2}, corresponding to a temperature drop greater than 2 degrees C across the deposits. The concentration factor resulting from the hideout increased highly non-linearly with the heat flux (varying as high as the fourth power of the heat flux). The decrease in the apparent concentration factor with increasing deposit thickness suggested that the pores in the deposit were occupied by a mixture of steam and water, which is consistent with the conclusion from the thermal conductivity measurements on deposits in a separate study. Analyses of the deposits after the hideout tests showed no evidence of any hidden-out solute species, probably due to the concentrations being very near the detection limits and to their escape from the deposit as the tests were being ended. This study showed that hideout in deposits may concentrate solutes in the steam generator bulk water by a factor as high as 2 x 10{sup 3}. Corrosion was evident under the deposit in some tests, with some chromium enrichment on the surface of the tube. Chromium enrichment usually indicates an acidic environment, but the mobility required of chromium to become incorporated into the thick magnetite deposit may indicate corrosion under an alkaline environment. An alkaline environment could result from preferential accumulation of sodium in the solution in the deposit during the hideout process. (author)

  15. Accurate measurement method for tube's endpoints based on machine vision (United States)

    Liu, Shaoli; Jin, Peng; Liu, Jianhua; Wang, Xiao; Sun, Peng


    Tubes are used widely in aerospace vehicles, and their accurate assembly can directly affect the assembling reliability and the quality of products. It is important to measure the processed tube's endpoints and then fix any geometric errors correspondingly. However, the traditional tube inspection method is time-consuming and complex operations. Therefore, a new measurement method for a tube's endpoints based on machine vision is proposed. First, reflected light on tube's surface can be removed by using photometric linearization. Then, based on the optimization model for the tube's endpoint measurements and the principle of stereo matching, the global coordinates and the relative distance of the tube's endpoint are obtained. To confirm the feasibility, 11 tubes are processed to remove the reflected light and then the endpoint's positions of tubes are measured. The experiment results show that the measurement repeatability accuracy is 0.167 mm, and the absolute accuracy is 0.328 mm. The measurement takes less than 1 min. The proposed method based on machine vision can measure the tube's endpoints without any surface treatment or any tools and can realize on line measurement.

  16. Experimental study on a simple Ranque Hilsch vortex tube (United States)

    Gao, C. M.; Bosschaart, K. J.; Zeegers, J. C. H.; de Waele, A. T. A. M.


    The Ranque-Hilsch vortex tube is a device by which cold gas can be generated using compressed gas. To understand the cooling mechanism of this device, it is necessary to know the pressure, temperature, and velocity distributions inside the tube. In order to investigate this, a simple vortex tube is built and nitrogen is used as its working fluid. A special Pitot tube is used for the measurement of the pressure and velocity. This Pitot tube consists of a capillary which has only one hole in the cylinder wall. With this Pitot tube, the pressure and velocity fields inside the tube were measured. In the same way, the temperature field was measured with a thermocouple. The results of three different entrance conditions are compared here. With the measurements results, the analysis based on the two thermodynamic laws has been made. It is found that rounding off the entrance has influence on the performance of the vortex tube. The secondary circulation gas flow inside the vortex tube can be enhanced and enlarged, the performance of the Ranque-Hilsch vortex tube improved.

  17. Warfarin bioavailability with feeding tubes and enteral formula. (United States)

    Klang, Mark; Graham, Dennis; McLymont, Veronica


    Earlier literature showed reduced efficacy of warfarin when co-administered with enteral nutrition formulas through feeding tubes. This study used an in vitro model for gastric administration of warfarin through a feeding tube to evaluate potential causes for reduced warfarin absorption when administered through feeding tubes. There were 2 phases of the study. The first phase used an artificial stomach model with or without the infusion of enteral nutrition formula. Warfarin was added to the contents either directly into the vessel or passed through a feeding tube. Warfarin tablet dissolution was compared to the injectable formulation, which served as a control. The second phase used chopped feeding tube material added to beakers containing warfarin in increasing amounts. Warfarin injection and tablet formulations showed decreased solubility when combined with acid. The warfarin solubility was higher when enteral formula was added. Warfarin concentration dropped by 35% when the drug was passed through a feeding tube, as opposed to added directly to the flask.In the second study, the warfarin levels were lower in the beakers containing feeding tubes. Doubling the amount of warfarin added did not raise levels to that of the initial dissolved. Doubling the amount of feeding tube material further reduced the concentration dissolved. Feeding-tube administration compromises the total amount of warfarin reaching patients. It appears, from this in vitro study, that the mechanism of the interaction of warfarin may be a result of direct binding to the feeding tube.

  18. Fuel cell tubes and method of making same (United States)

    Borglum, Brian P.


    A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost. A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost.

  19. Percutaneous endoscopic gastrostomy tube replacement: A simple procedure? (United States)

    Lohsiriwat, Varut


    Replacement of gastrostomy tube in patients undergoing percutaneous endoscopic gastrostomy (PEG) is generally considered as a safe and simple procedure. However, it could be associated with serious complications, such as gastrocutaneous tract disruption and intraperitoneal tube placement, which may lead to chemical peritonitis and even death. When PEG tube needs a replacement (e.g., occlusion or breakage of the tube), clinicians must realize that the gastrocutaneous tract of PEG is more friable than that of surgical gastrostomy because there is no suture fixation between gastric wall and abdominal wall in PEG. In general, the tract of PEG begins to mature in 1-2 wk after placement and it is well formed in 4-6 wk. However, this process could take a longer period of time in some patients. Accordingly, this article describes three major principles of a safe PEG tube replacement: (1) good control of the replacement tube along the well-formed gastrocutaneous tract; (2) minimal insertion force during the replacement, and, most importantly; and (3) reliable methods for the confirmation of intragastric tube insertion. In addition, the management of patients with suspected intraperitoneal tube placement (e.g., patients having abdominal pain or signs of peritonitis immediately after PEG tube replacement or shortly after tube feeding was resumed) is discussed. If prompt investigation confirms the intraperitoneal tube placement, surgical intervention is usually required. This article also highlights the fact that each institute should have an optimal protocol for PEG tube replacement to prevent, or to minimize, such serious complications. Meanwhile, clinicians should be aware of these potential complications, particularly if there are any difficulties during the gastrostomy tube replacement.

  20. Collagen plug occlusion of Molteno tube shunts. (United States)

    Stewart, W; Feldman, R M; Gross, R L


    We report five patients in whom collagen lacrimal plugs were used to temporarily occlude the lumen of Molteno shunts to prevent early postoperative hypotony. Only one eye, with a double plate, developed hypotony and a flat anterior chamber that required reformation. However, in three patients, the collagen plugs did not dissolve and had to be removed surgically to lower the intraocular pressure. Although the semipermeability of collagen is desirable, its unpredictable degradation renders it unsuitable for temporary occlusion of tube shunts. Other biodegradable materials may be more appropriate for this purpose.


    Directory of Open Access Journals (Sweden)

    Aytunç EREK


    Full Text Available This study presents the heat transfer enhancement in the thermal energy storage system by using radially finned tube. The solution of the system consists of the solving the equations of the heat transfer fluid (HTF, the pipe wall and fin, and the phase change material (PCM as one domain. The control volume finite difference approach and the semi implicit solver (SIS are used to solve the equations. Fully developed velocity distribution is taken in the HTF. Flow parameters (Re number and inlet temperature of coolant and fin parameters (the number of fins, fin length, fin thickness are found to influence solidification fronts and the total stored energy.

  2. Traveling wave tube and method of manufacture (United States)

    Vancil, Bernard K. (Inventor)


    A traveling wave tube includes a glass or other insulating envelope having a plurality of substantially parallel glass rods supported therewithin which in turn support an electron gun, a collector and an intermediate slow wave structure. The slow wave structure itself provides electrostatic focussing of a central electron beam thereby eliminating the need for focussing magnetics and materially decreasing the cost of construction as well as enabling miniaturization. The slow wave structure advantageously includes cavities along the electron beam through which the r.f. energy is propagated, or a double, interleaved ring loop structure supported by dielectric fins within a ground plane cylinder disposed coaxially within the glass envelope.

  3. Carbon nanoelectronics: unzipping tubes into graphene ribbons. (United States)

    Santos, H; Chico, L; Brey, L


    We report on the transport properties of novel carbon nanostructures made of partially unzipped carbon nanotubes, which can be regarded as a seamless junction of a tube and a nanoribbon. We find that graphene nanoribbons act at certain energy ranges as perfect valley filters for carbon nanotubes, with the maximum possible conductance. Our results show that a partially unzipped carbon nanotube is a magnetoresistive device, with a very large value of magnetoresistance. We explore the properties of several structures combining nanotubes and graphene nanoribbons, demonstrating that they behave as optimal contacts for each other, and opening a new route for the design of mixed graphene-nanotube devices.

  4. Drift Tube Linac Conditioning of Tank1

    CERN Document Server

    Shafqat, N; Toor, W A


    Tank1 of the Drift Tube Linac (DTL) of the Linac4 has been conditioned at the Linac4 tunnel. The tank was tuned for resonance at 352.2 MHz, and stable operation has been achieved with 725 µs long RF pulses at a repetition rate of 1 Hz. The maximum RF level that has been reached is 810 kW with a pulse width of 600 µs. Since this was the first RF structure exclusively conditioned in the Linac4 tunnel with the operation and control software of Linac4, some related issues and limitations had to be taken into account.

  5. Sound Coiled-Tubing Drilling Practices

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Thomas; Deskins, Greg (Maurer Technology Inc.); Ward, Stephen L. (Advantage Energy Services Ltd); Hightower, Mel


    This Coiled-Tubing Drilling (CTD) Sound Practices Manual provides tools needed by CTD engineers and supervisors to plan, design and perform safe, successful CTD operations. As emphasized throughout, both careful planning and attention to detail are mandatory for success. A bibliography of many useful CTD references is presented in Chapter 6. This manual is organized according to three processes: 1) Pre-Job Planning Process, 2) Operations Execution Process, and 3) Post-Job Review Process. Each is discussed in a logical and sequential format.

  6. Emergency battlefield cricothyrotomy complicated by tube occlusion

    Directory of Open Access Journals (Sweden)

    Gallo Andrew


    Full Text Available Emergency cricothyrotomy is a technique used to secure an otherwise compromised or inaccessible airway and has been recommended for use in the battlefield under certain circumstances. This case reports an acute complication of emergency cricothyrotomy. An Iraqi soldier, injured in an improvised explosive device blast received an emergency battlefield cricothyrotomy. At the Combat Support Hospital, the patient became more difficult to ventilate and was taken to the operating room for tracheostomy. The cricothyrotomy tube was found to be occluded with blood.

  7. Microtubules, polarity and vertebrate neural tube morphogenesis. (United States)

    Cearns, Michael D; Escuin, Sarah; Alexandre, Paula; Greene, Nicholas D E; Copp, Andrew J


    Microtubules (MTs) are key cellular components, long known to participate in morphogenetic events that shape the developing embryo. However, the links between the cellular functions of MTs, their effects on cell shape and polarity, and their role in large-scale morphogenesis remain poorly understood. Here, these relationships were examined with respect to two strategies for generating the vertebrate neural tube: bending and closure of the mammalian neural plate; and cavitation of the teleost neural rod. The latter process has been compared with 'secondary' neurulation that generates the caudal spinal cord in mammals. MTs align along the apico-basal axis of the mammalian neuroepithelium early in neural tube closure, participating functionally in interkinetic nuclear migration, which indirectly impacts on cell shape. Whether MTs play other functional roles in mammalian neurulation remains unclear. In the zebrafish, MTs are important for defining the neural rod midline prior to its cavitation, both by localizing apical proteins at the tissue midline and by orienting cell division through a mirror-symmetric MT apparatus that helps to further define the medial localization of apical polarity proteins. Par proteins have been implicated in centrosome positioning in neuroepithelia as well as in the control of polarized morphogenetic movements in the neural rod. Understanding of MT functions during early nervous system development has so far been limited, partly by techniques that fail to distinguish 'cause' from 'effect'. Future developments will likely rely on novel ways to selectively impair MT function in order to investigate the roles they play. © 2016 Anatomical Society.

  8. A novel method for coiled tubing installation

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Peter J. [2H Offshore, Houston, TX (United States); Tibbetts, David [Aquactic Engineering and Construction Ltd., Aberdeen (United Kingdom)


    Installation of flexible pipe for offshore developments is costly due to the physical cost of the flexible pipe, expensive day rates and the availability of suitable installation vessels. Considering the scarcity of flexible pipe in today's increasingly demanding and busy market, operators are seeking a cost effective solution for installing piping in a range of water depths using vessels which are readily on hand. This paper describes a novel approach to installing reeled coiled tubing, from 1 inch to 5 inch diameter, from the back of a small vessel in water depths from 40 m up to around 1000 m. The uniqueness of the system is the fact that the equipment design is modular and compact. This means that when disassembled, it fits into standard 40 ft shipping containers, and the size allows it to be installed on even relatively small vessels of opportunity, such as anchor handling or installation vessels, from smaller, and cheaper quay side locations. Such an approach is the ideal solution to the problem faced by operators, in that it allows the installation of cheaper, readily available coiled tubing, from cost-effective vessels, which do not need to transit to a pick up the system. (author)

  9. Space-Qualified Traveling-Wave Tube (United States)

    Wilson, Jeffrey D.; Krawczyk, Richard; Simons, Rainee N.; Williams, Wallace D.; Robbins, Neal R.; Dibb, Daniel R.; Menninger, William L.; Zhai, Xiaoling; Benton, Robert T.


    The L-3 Communications Electron Technologies, Inc. Model 999HA traveling-wave tube (TWT), was developed for use as a high-power microwave amplifier for high-rate transmission of data and video signals from deep space to Earth (see figure). The 999HA is a successor to the 999H a non-space qualified TWT described in High-Power, High-Efficiency Ka-Band Traveling-Wave Tube (LEW-17900-1), NASA Tech Briefs, Vol. 31, No. 2 (February 2007), page 32. Operating in the 31.8-to-32.3 GHz frequency band, the 999HA has been shown to generate 252 W of continuous- wave output power at 62 percent overall power efficiency a 75-percent increase in output power over the 999H. The mass of the 999HA is 35 percent less than that of the 999H. Moreover, taking account of the elimination of a Faraday cage that is necessary for operation of the 999H but is obviated by a redesign of high-voltage feed-throughs for the 999HA, the overall reduction in mass becomes 57 percent with an 82 percent reduction in volume. Through a series of rigorous tests, the 999HA has been qualified for operation aboard spacecraft with a lifetime exceeding seven years. Offspring of the 999HA will fly on the Kepler and Lunar Reconnaissance Orbiter missions.

  10. Utility of feeding jejunostomy tubes in pancreaticoduodenectomy. (United States)

    Waliye, Hussein E; Wright, G Paul; McCarthy, Caitlin; Johnson, Jared; Scales, Alex; Wolf, Andrea; Chung, Mathew


    Routine placement of jejunostomy tubes (JT) during pancreaticoduodenectomy (PD) is controversial. A retrospective chart review of patients undergoing PD from 1/1/08 through 12/31/14 was performed. The patients were divided into groups by placement of JT. Outcome measures were 90-day morbidity, 90-day mortality, length of stay, rate of delayed gastric emptying (DGE), and JT-specific complications. 256 patients were included. There were no significant differences in 90-day morbidity (39.9% vs. 37.9%, p = 0.747), 90-day mortality (3.9% vs. 1.0%, p = 0.247) or TPN use (24.8 vs. 25.2%, p = 0.941) between those with and without JT, respectively. Patients with a JT had a higher rate of DGE (p < 0.001), longer hospital stay (14.3 vs. 11.6, p < 0.001), and longer time to solid intake (9.4 vs. 7.3, p < 0.001). Eleven patients (7.2%) with JT had tube-related morbidity. Routine placement of JT at the time of PD should be abandoned with efforts focused on preoperative nutrition optimization and early oral diet trials. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Casimir effect in hemisphere capped tubes

    CERN Document Server

    de Mello, E R Bezerra


    In this paper we investigate the vacuum densities for a massive scalar field with general curvature coupling in background of a (2+1)-dimensional spacetime corresponding to a cylindrical tube with a hemispherical cap. A complete set of mode functions is constructed and the positive-frequency Wightman function is evaluated for both the cylindrical and hemispherical subspaces. On the base of this, the vacuum expectation values of the field squared and energy-momentum tensor are investigated. The mean field squared and the normal stress are finite on the boundary separating two subspaces, whereas the energy density and the parallel stress diverge as the inverse power of the distance from the boundary. For a conformally coupled field, the vacuum energy density is negative on the cylindrical part of the space. On the hemisphere, it is negative near the top and positive close to the boundary. In the case of minimal coupling the energy density on the cup is negative. On the tube it is positive near the boundary and ...

  12. Investigation of phthalate release from tracheal tubes. (United States)

    Morton, W J; Muller, C T; Goodwin, N; Wilkes, A R; Hall, J E


    Phthalates are chemicals used extensively in the manufacture of plastics for their desirable physical characteristics. In addition to enhancing the performance of plastics, phthalates have a number of undesirable effects, principally endocrine disruptor effects, that may have adverse effects on reproductive development and functioning. As a result, they have been banned from the manufacture of children's toys. Despite this, they continue to be used in the manufacture of medical devices, including anaesthetic equipment. This study aimed to assess phthalate release from five brands of tracheal tube. Using gas chromatography-mass spectrometry, we analysed phthalate concentrations from samples of ultra pure water in which tracheal tubes had been submerged. Phthalate concentration increased from 6.7 to 149 μg.l(-1) over a period of 4.8 days. Phthalate release from anaesthetic equipment has not previously been documented over short time periods and raises the possibility of iatrogenic endocrine disruption with routine anaesthesia. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.

  13. Failure analysis of the boiler water-wall tube

    Directory of Open Access Journals (Sweden)

    S.W. Liu


    Full Text Available Failure analysis of the boiler water-wall tube is presented in this work. In order to examine the causes of failure, various techniques including visual inspection, chemical analysis, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy were carried out. Tube wall thickness measurements were performed on the ruptured tube. The fire-facing side of the tube was observed to have experienced significant wall thinning. The composition of the matrix material of the tube meets the requirements of the relevant standards. Microscopic examinations showed that the spheroidization of pearlite is not very obvious. The failure mechanism is identified as a result of the significant localized wall thinning of the boiler water-wall tube due to oxidation.

  14. The Functionality of Paratexts on YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo


    This chapter investigates paratexts and their functionality on YouTube. It is argued that YouTube content is in fact characterized by its dependence and usage of paratexts as part of YouTube's infrastructure. Paratexts are presented as being either auto-generated by YouTube or created by its users....... They are furthermore identified through a distinction between spatial and temporal relationships. Based on these distinctions, a small survey of some of the most popular videos on YouTube is conducted in order to examine the appearance and functionality of paratexts. A principal argument of the chapter...... is that the functionality of the paratexts can be explained by what Genette characterizes as the paratext's illocutionary force, which is examined in relationship to YouTube's paratexts and, more specifically, the site's implementation of links. The chapter also argues that paratexts may be characterized as a necessary...

  15. Virtual Community Based Destination Marketing with YouTube

    DEFF Research Database (Denmark)

    Sambhanthan, Arunasalam; Thelijjagoda, Samantha; Good, Alice


    YouTube has now evolved into a powerful medium for social interaction. Utilizing YouTube for enhancing marketing endeavours is a strategy practiced by marketing professionals across several industries. This paper rationalizes on the different strategies of leveraging YouTube-based platforms...... for effective destination marketing by the hospitality industry (hotels) and provides insights on the critical drivers and challenges embedded within YouTube-based community interactions for destination marketing. The comments made by YouTube users have been subjected to a content analysis and the results...... are reported under the five broad clusters of virtual communities. More broadly, the typology of virtual communities is adapted to evaluate the YouTube platform for effective destination marketing....

  16. Longitudinal zipping/unzipping of self-assembled organic tubes. (United States)

    Zhang, Xuejun; Bera, Tanmay; Liang, Wenlang; Fang, Jiyu


    Stimuli-responsive organic tubes are an attractive supramolecular assembly which has potential applications as a controlled release vehicle. We synthesize a smart organic tube by the coassembly of lithocholic acid (LCA) and taurolithocholic acid (TLCA) in aqueous solution. The coassembled LCA/TLCA tubes can be longitudinally unzipped into flat sheets by capillary force after being dehydrated on substrates. Consequently, the encapsulated guest molecules are released from the unzipping tubes. After the release of guest molecules, the flat sheets can be zipped back into hollow tubes upon hydration with aqueous solution. The zipping/unzipping LCA/TLCA tubes provide a new type of delivery vehicles, which may have potential for surface decontaminations.

  17. Circumferential buckling instability of a growing cylindrical tube

    KAUST Repository

    Moulton, D.E.


    A cylindrical elastic tube under uniform radial external pressure will buckle circumferentially to a non-circular cross-section at a critical pressure. The buckling represents an instability of the inner or outer edge of the tube. This is a common phenomenon in biological tissues, where it is referred to as mucosal folding. Here, we investigate this buckling instability in a growing elastic tube. A change in thickness due to growth can have a dramatic impact on circumferential buckling, both in the critical pressure and the buckling pattern. We consider both single- and bi-layer tubes and multiple boundary conditions. We highlight the competition between geometric effects, i.e. the change in tube dimensions, and mechanical effects, i.e. the effect of residual stress, due to differential growth. This competition can lead to non-intuitive results, such as a tube growing to be thinner and yet buckle at a higher pressure. © 2011 Elsevier Ltd. All rights reserved.

  18. Experience with a new gastrostomy-jejunal feeding tube. (United States)

    Rombeau, J L; Twomey, P L; McLean, G K; Forlaw, L; Del Rio, D; Caldwell, M D


    Many patients in need of long-term feeding by tube enterostomy have neurologic or mechanical deficits that increase their risk for aspiration. To reduce this risk, a combined gastrostomy-jejunal tube has been developed. This tube permits gastric decompression while the formula is being delivered into the jejunum. The use of this tube has been evaluated in 45 patients. There were three (7%) major complications and two (4%) postoperative deaths. The deaths did not appear to be directly related to the insertion of the tube. There was no clinical evidence of aspiration. This tube can be used to deliver postoperative and long-term enteral nutrition with minimal rates of morbidity and mortality.

  19. Failure of a MEA reclaimer tube bundle due to corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Shaban, H.; Abdo, M.S.E.; Lal, D.P.


    The removal of sulphur compounds from natural gas used in ammonia production is carried out by scrubbing with monoethanol amine (MEA). To avoid build up of corrosion and degradation products, a portion of the circulating MEA solution is passed through a reclaimer. This is essentially a kettle-type reboiler with a tube bundle made of 316L stainless steel. Occasional failures of the tube bundle due to pitting corrosion have been reported. It is suggested that the excessive pitting corrosion observed on the upper rows of the tube bundle could be partly due to high steam temperature but mainly due to the liquid level falling below the tubes leaving an accumulation of corrosive degradation products on the exposed surfaces, normally these corrosive products remain diluted in the MEA solution and cause little corrosion of the covered tubes. Their concentration on the dry upper layers of the hot metal tubes, however, leads to excessive corrosion. (U.K.).

  20. Dryout Quality for Refrigerants Flowing in Horizontal Evaporator Tubes (United States)

    Mori, Hideo; Kakimoto, Yasushi; Ohishi, Katsumi

    The present paper reports an investigation of the dryout quality for refrigerants flowing in horizontal evaporator tubes. Experiments were made for the flow of boiling HFC-134a and HCFC-22 inside smooth tubes and a spirally grooved (micro-fin) tube. At given conditions, dryout proceeded over a certain quality range. Therefore two dryout qualities were defined; dryout inception quality at which the circumferentially averaged (axially local) heat transfer coefficient began to decrease rapidly, and dryout completion quality at which the decrease in the heat transfer coefficient ended. Based on the experimental data, the characteristics of both dryout qualities were clarified, and thereby the dryout qualities were classified into three characteristic regimes for the smooth tube and two regimes for the micro-fin tube. A dimensionless correlation of each dryout quality, which can reproduce the measurement successfully, was developed for the respective tubes.

  1. Magnetic resonance imaging of nasopharyngeal carcinoma. Correlation with otitis media with effusion (OME)

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Y.; Tamaki, S.; Kurata, K.; Honjo, I.; Nishimura, K.; Nakano, Y.


    Magnetic resonance imaging (MRI) of the nasopharynx, the eustachian tube and the middle ear was performed in nine patients with nasopharyngeal carcinoma. MRI revealed the extent of the tumor more clearly than CT (computed tomography) when the tumor was situated in the parapharyngeal space. But when the tumor extended superficially in the nasopharyngeal mucosa, its margin could not be identified clearly by either MRI or CT because of hypervascularity and long T1 and T2 of the nasopharyngeal mucosa. Seven of the nine patients had unilateral otitis media with effusion. Their eustachian tube ventilation function was evaluated by an inflation-deflation technique. Failure of active equalization of negative pressure applied to the middle ear was found to be a characteristic disorder of their eustachian tube ventilation function. This dysfunction seemed to be correlated with the lateral dislocation of the eustachian tube cartilage caused by the tumor.

  2. Better Ear Health (United States)

    ... requests or policy questions to our media and public relations staff at . Many medical conditions, ... This condition usually results from poor eustachian tube function concurrent with middle ear infection (otitis media), but ...

  3. Cholesteatoma (United States)

    ... requests or policy questions to our media and public relations staff at . An abnormal skin ... cholesteatoma usually occurs because of poor eustachian tube function as well as infection in the middle ear. ...

  4. Middle ear infection (otitis media) (image) (United States)

    Otitis media is an inflammation or infection of the middle ear. Acute otitis media (acute ear infection) occurs when there is ... which causes production of fluid or pus. Chronic otitis media occurs when the eustachian tube becomes blocked ...

  5. A study of middle ear reconstruction, the degree of functional restoration and causes of graft failure following chronic ear disease

    Directory of Open Access Journals (Sweden)

    Vishnu Prasad


    Conclusion: Patients with normal Eustachian tube function, large and medium size mastoids, small and medium size perforations of the tympanic membrane would have a good rate of graft uptake with tympano-ossiculoplasties thereby returning to normal hearing postoperatively.

  6. Local Heat Transfer for Finned-Tube Heat Exchangers using Oval Tubes

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, James Edward; Sohal, Manohar Singh


    This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with either a circular tube or an elliptical tube in crossflow. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.56 x 10-3 to 15.6 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 630 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. The elliptical tube had an aspect ratio of 3:1 and a/H equal to 4.33. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of circular and oval tubes and their relationship to the complex horseshoe vortex system that forms in the flow stagnation region. Fin surface stagnation-region Nusselt numbers are shown to be proportional to the square-root of Reynolds number.

  7. Clinical tube weaning supported by hunger provocation in fully-tube-fed children. (United States)

    Hartdorff, Caroline M; Kneepkens, C M Frank; Stok-Akerboom, Anita M; van Dijk-Lokkart, Elisabeth M; Engels, Michelle A H; Kindermann, Angelika


    Children with congenital malformations, mental retardation, and complex early medical history frequently have feeding problems. Although tube feeding is effective in providing the necessary energy and nutrients, it decreases the child's motivation to eat and may lead to oral aversion. In this study, we sought to confirm our previous results, showing that a multidisciplinary clinical hunger provocation program may lead to quick resumption of oral feeding. In a crossover study, 22 children of 9 to 24 months of age who were fully dependent on tube feeding were randomly assigned to one of two groups: group A, intervention group (2-week multidisciplinary clinical hunger provocation program); and group B, control group (4-week outpatient treatment by the same multidisciplinary team). Patients failing one treatment were reassigned to the other treatment group. Primary outcome measures were at least 75% orally fed at the conclusion of the intervention and fully orally fed and gaining weight 6 months after the intervention. In group A, 9/11 patients were successfully weaned from tube feeding (2 failures: 1 developed ulcerative colitis, 1 drop-out). In group B, only 1 patient was weaned successfully; 10/11 were reassigned to the clinical hunger provocation program, all being weaned successfully. Six months after the intervention, 1 patient had to resume tube feeding. In total, in the control group, 1/11 (9%) was weaned successfully as compared with 18/21 (86%) in the hunger provocation group (P hunger provocation is an effective short-term intervention for weaning young children from tube feeding.

  8. A method and sensor for the eddy current non destructive testing of thin tubes; Procede de controle non destructif d`un tube mince par courants de Foucault

    Energy Technology Data Exchange (ETDEWEB)

    Sartre, B.; Miller, D.; Placko, D.


    In order to control the wear (cracking or thinning) of vapor generator tubes, especially in PWR reactors, due to the friction between the tubes and dampers, an eddy current control system is proposed where the transducer is run through the tubes, and measures the tube wall thickness or tube-block clearance through impedance measurements, taking into account the variation of the sensor-to-tube distance. 8 fig.

  9. The Hardy inequality and the heat equation in twisted tubes


    Krejčiřík, David; Zuazua, Enrique


    We show that a twist of a three-dimensional tube of uniform cross-section yields an improved decay rate for the heat semigroup associated with the Dirichlet Laplacian in the tube. The proof employs Hardy inequalities for the Dirichlet Laplacian in twisted tubes and the method of self-similar variables and weighted Sobolev spaces for the heat equation. © 2010 Elsevier Masson SAS.

  10. Test Station for Measuring Aluminum Tube Geometrical Parameters

    CERN Document Server

    Oansea, D; Gongadze, A L; Gostkin, M I; Dedovich, D V; Evtoukhovitch, P G; Comanescu, B; Kotov, S A; Necsoiu, T; Potrap, I N; Rogalev, E V; Tskhadadze, E G; Chelkov, G A


    A test station for quality control of aluminum tube outer diameter and wall thickness is presented. The tested tubes are used for drift detector assembly of ATLAS (LHC, CERN) muon system. The outer diameter and wall thickness of aluminium tubes are measured by means of noncontact optical and ultrasonic methods respectively with the accuracy of 3 {\\mu}m. The testing process is automatic and interacts with the production data base.

  11. An untapped resource: using YouTube in nursing education. (United States)

    Agazio, Janice; Buckley, Kathleen M


    Minimal information is available in the literature addressing video sharing in nursing education. Using multiple examples, the authors discuss the use of YouTube, a popular video-sharing and social networking site. YouTube is used to illustrate theoretical content, involve students, and inspire innovative teaching methods. Faculty can use this technology to stimulate student discussions, share information, and create a learning community. YouTube stimulates active learning and brings new relevance and applications to nursing curriculum.

  12. Equilibrium model of thin magnetic flux tubes. [solar atmosphere (United States)

    Bodo, G.; Ferrari, A.; Massaglia, S.; Kalkofen, W.; Rosner, R.


    The existence of a physically realizable domain in which approximations that lead to a self consistent solution for flux tube stratification in the solar atmosphere, without ad hoc hypotheses, is proved. The transfer equation is solved assuming that no energy transport other than radiative is present. Convective motions inside the tube are assumed to be suppressed by magnetic forces. Only one parameter, the plasma beta at tau = 0, must be specified, and this can be estimated from observations of spatially resolved flux tubes.

  13. Stroke: ineffective tube securement reduces nutrition and drug treatment. (United States)

    Brazier, Sophie; Taylor, Stephen J; Allan, Kaylee; Clemente, Rowan; Toher, Deirdre


    Stroke patients with dysphagia often depend on nutrition, hydration and medication via nasogastric (NG) feeding tubes. Securing tubes using tape is associated with repeated tube loss. In this study, the authors determined cause and effect by auditing tube placement methods, delays incurred, duration and costs. Of 202 NG tube placements in 75 patients, 67 placements occurred in 17 patients over a full course of enteral nutrition (EN) and 40 of these placements were tracked. Tubes were secured by tape in 100%, mittens 31% and special observation 5.4%. However, over an EN course, inadvertent tube loss occurred in 82% of patients and was associated with age (p=0.049) and mitten use (ptubes were lost due to patients and 9% slipped. Average 'tube life' was 2 days, less than 25% of the EN episode (ptube placement occurred within 2.55 hours of request, X-ray confirmation led to a delay in feed and drugs of 8-9 hours per tube placement and loss of 18.8% of feeding time per EN episode. Delays exceeded the 1-hour and 4-hour limits for antibiotics and other medicines in 20% and 80%, respectively. In the 17 tracked patients, it was estimated that 55% of the £5979 direct costs could be saved by nasal bridle use. In conclusion, most tubes studied were lost to inadvertent tube removal, leading to clinically significant delays to nutrition, hydration and drug treatments; this may impair recovery. Reducing tube loss is likely to reduce patient distress, treatment cost and enhance recovery.

  14. Computer simulation of the fire-tube boiler hydrodynamics

    Directory of Open Access Journals (Sweden)

    Khaustov Sergei A.


    Full Text Available Finite element method was used for simulating the hydrodynamics of fire-tube boiler with the ANSYS Fluent 12.1.4 engineering simulation software. Hydrodynamic structure and volumetric temperature distribution were calculated. The results are presented in graphical form. Complete geometric model of the fire-tube boiler based on boiler drawings was considered. Obtained results are suitable for qualitative analysis of hydrodynamics and singularities identification in fire-tube boiler water shell.

  15. Sudden endotracheal tube block in a patient of Achalasia Cardia

    Directory of Open Access Journals (Sweden)

    Ajit Gupta


    Full Text Available Endotracheal tube block due to various mechanical causes such as mucous, blood clot, denture, and ampoules have been reported. A patient of achalasia cardia with chronic passive aspiration pneumonitis developed mucoid mass in the respiratory passage which dislodged during the surgical procedure. The episode occurred almost an hour after induction of anesthesia and the dislodged mucoid mass blocked the lumen of endotracheal tube, leading to hypoxia and impending cardiac arrest. However, the patient was salvaged by replacing the tube.

  16. The Topology of Canonical Flux Tubes in Flared Jet Geometry


    Lavine, Eric Sander; You, Setthivoine


    Magnetized plasma jets are generally modeled as magnetic flux tubes filled with flowing plasma governed by magnetohydrodynamics (MHD). We outline here a more fundamental approach based on flux tubes of canonical vorticity, where canonical vorticity is defined as the circulation of the species canonical momentum. This approach extends the concept of magnetic flux tube evolution to include the effects of finite particle momentum and enables visualization of the topology of plasma jets in regime...

  17. The SCC testing of nuclear steam generator tubing materials (United States)

    Doherty, P. E.; Sarver, J. M.; Miglin, B. P.


    The integrity of heat-exchanger tubes in a nuclear reaction system is crucial for the safe operation of a power plant. In order to study the corrosion behavior of certain alloys, constant extension rate (CERT) tests were performed on alloy 690 and alloy 800 nuclear steam generator tubing specimens. In this article, the CERT test results (such as maximum stress achieved and crack morphology) are correlated to tubing microstructure, chemistry, and manufacturing processes.

  18. Structure of sunspot penumbrae - Fallen magnetic flux tubes (United States)

    Wentzel, Donat G.


    A model is presented of a sunspot penumbra involving magnetic flux tubes that have fallen into the photosphere and float there. An upwelling at the inner end of a fallen tube continuously provides additional gas. This gas flows along and lengthens the tube and is observable as the Evershed flow. Fallen flux tubes may appear as bright streaks near the upwelling, but they become dark filaments further out. The model is corroborated by recent optical high-resolution magnetic data regarding the penumbral filaments, by the 12-micron magnetic measurements relevant to the height of the temperature minimum, and by photographs of the umbra/penumbra boundary.

  19. Fracture analysis of HFIR beam tube caused by radiation embrittlement

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.J. [Oak Ridge National Lab., TN (United States). Research Reactors Div.


    With an attempt to estimate the neutron beam tube embrittlement condition for the Oak Ridge High Flux Isotope Reactor (HFIR), fracture mechanics calculations are carried out in this paper. The analysis provides some numerical result on how the tube has been structurally weakened. In this calculation, a lateral impact force is assumed. Numerical result is obtained on how much the critical crack size should be reduced if the beam tube has been subjected to an extended period of irradiation. It is also calculated that buckling strength of the tube is increased, not decreased, with irradiation.

  20. Percutaneous Endoscopic Gastrojejunostomy Tube Placement in Healthy Dogs and Cats

    National Research Council Canada - National Science Library

    Jergens, Albert E; Morrison, Jo Ann; Miles, Krisrtina G; Silverman, William B


    Background: Pancreatitis, hepatobiliary disease, and proximal gastrointestinal tract disorders are clinical situations where delivery of nutrients via jejunostomy tube is preferable to a feeding gastrostomy...

  1. Status of steam generator tubing integrity at Jaslovske Bohunice NPP

    Energy Technology Data Exchange (ETDEWEB)

    Cepcek, S. [Nuclear Regulatory Authority of the Slovak Republic, Trnava (Slovakia)


    Steam generator represents one of the most important component of nuclear power plants. Especially, loss of tubing integrity of steam generators can lead to the primary coolant leak to secondary circuit and in worse cases to the unit shut down or to the PTS events occurrence. Therefore, to ensure the steam generator tubing integrity and the current knowledge about tube degradation propagation and development is of the highest importance. In this paper the present status of steam generator tubing integrity in operated NPP in Slovak Republic is presented.

  2. Cell Wall Composition, Biosynthesis and Remodeling during Pollen Tube Growth

    Directory of Open Access Journals (Sweden)

    Jean-Claude Mollet


    Full Text Available The pollen tube is a fast tip-growing cell carrying the two sperm cells to the ovule allowing the double fertilization process and seed setting. To succeed in this process, the spatial and temporal controls of pollen tube growth within the female organ are critical. It requires a massive cell wall deposition to promote fast pollen tube elongation and a tight control of the cell wall remodeling to modify the mechanical properties. In addition, during its journey, the pollen tube interacts with the pistil, which plays key roles in pollen tube nutrition, guidance and in the rejection of the self-incompatible pollen. This review focuses on our current knowledge in the biochemistry and localization of the main cell wall polymers including pectin, hemicellulose, cellulose and callose from several pollen tube species. Moreover, based on transcriptomic data and functional genomic studies, the possible enzymes involved in the cell wall remodeling during pollen tube growth and their impact on the cell wall mechanics are also described. Finally, mutant analyses have permitted to gain insight in the function of several genes involved in the pollen tube cell wall biosynthesis and their roles in pollen tube growth are further discussed.

  3. Mechanistic insights from a quantitative analysis of pollen tube guidance

    Directory of Open Access Journals (Sweden)

    Bhimalapuram Prabhakar


    Full Text Available Abstract Background Plant biologists have long speculated about the mechanisms that guide pollen tubes to ovules. Although there is now evidence that ovules emit a diffusible attractant, little is known about how this attractant mediates interactions between the pollen tube and the ovules. Results We employ a semi-in vitro assay, in which ovules dissected from Arabidopsis thaliana are arranged around a cut style on artificial medium, to elucidate how ovules release the attractant and how pollen tubes respond to it. Analysis of microscopy images of the semi-in vitro system shows that pollen tubes are more attracted to ovules that are incubated on the medium for longer times before pollen tubes emerge from the cut style. The responses of tubes are consistent with their sensing a gradient of an attractant at 100-150 μm, farther than previously reported. Our microscopy images also show that pollen tubes slow their growth near the micropyles of functional ovules with a spatial range that depends on ovule incubation time. Conclusions We propose a stochastic model that captures these dynamics. In the model, a pollen tube senses a difference in the fraction of receptors bound to an attractant and changes its direction of growth in response; the attractant is continuously released from ovules and spreads isotropically on the medium. The model suggests that the observed slowing greatly enhances the ability of pollen tubes to successfully target ovules. The relation of the results to guidance in vivo is discussed.

  4. Dynamic Response and Fracture of Composite Gun Tubes

    Directory of Open Access Journals (Sweden)

    Jerome T. Tzeng


    Full Text Available The fracture behavior due to dynamic response in a composite gun tube subjected to a moving pressure has been investigated. The resonance of stress waves result in very high amplitude and frequency strains in the tube at the instant and location of pressure front passage as the velocity of the projectile approaches a critical value. The cyclic stresses can accelerate crack propagation in the gun tube with an existing imperfection and significantly shorten the fatigue life of gun tubes. The fracture mechanism induced by dynamic amplification effects is particularly critical for composite overwrap barrels because of a multi-material construction, anisotropic material properties, and the potential of thermal degradation.

  5. Design and Fabrication of hand operated mini Shock Tube (United States)

    Nambiar, Gautham K.; Sriram, M.; Dharanidhar, M.; Nair, Prashant G.; Nagaraja, S. R.


    Shock waves have been used for medical, biological and industrial applications. In this paper design, frication and calibration of a low cost mini shock tube is presented. Commercial FEM software COMSOL multiphysics is used for analysis of shock tube flows. The hand operated mini shock tube is capable of generating shock Mach numbers up to 1.8, peak over pressures up to 8 bar. Experimental and theoretical values of pressure ratio jump primary and reflected shock closely agree with each other. The fabricated shock tube is used for free forming of metallic foils.

  6. Tracheomegaly Secondary to Tracheotomy Tube Cuff in Amyotrophic Lateral Sclerosis (United States)

    Lee, Dong Hoon; Yoon, Tae Mi; Lee, Joon Kyoo; Lim, Sang Chul


    Abstract Tracheomegaly has not been reported in amyotrophic lateral sclerosis (ALS). Herein, the authors report a case of tracheomegaly secondary to tracheotomy tube cuff in a patient with ALS. To our knowledge, this is the first report of an ALS patient with tracheomegaly and of tracheomegaly being associated with tracheotomy tube cuff and home tracheotomy mechanical ventilator. The clinician should consider the possibility of tracheomegaly in the differential diagnosis, if a patient with ALS develops repeat air leakage around the tracheotomy tube or rupture of tracheotomy tube cuff. PMID:26496301

  7. Shape Modeling of a Concentric-tube Continuum Robot

    DEFF Research Database (Denmark)

    Bai, Shaoping; Xing, Charles Chuhao


    is modeled on the basis of energy approach for both the in-plane and out-plane cases. The torsional influences on the shape of the concentric-tube robots are considered. An experimental device was build for the model validation. The results of simulation and experiments are included and analyzed.......Concentric-tube continuum robots feature with simple and compact structures and have a great potential in medical applications. The paper is concerned with the shape modeling of a type of concentric-tube continuum robot built with a collection of super-elastic NiTiNol tubes. The mechanics...

  8. Steam generator tube rupture simulation using extended finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Subhasish, E-mail:; Majumdar, Saurin; Natesan, Ken


    Highlights: • Extended finite element method used for modeling the steam generator tube rupture. • Crack propagation is modeled in an arbitrary solution dependent path. • The FE model is used for estimating the rupture pressure of steam generator tubes. • Crack coalescence modeling is also demonstrated. • The method can be used for crack modeling of tubes under severe accident condition. - Abstract: A steam generator (SG) is an important component of any pressurized water reactor. Steam generator tubes represent a primary pressure boundary whose integrity is vital to the safe operation of the reactor. SG tubes may rupture due to propagation of a crack created by mechanisms such as stress corrosion cracking, fatigue, etc. It is thus important to estimate the rupture pressures of cracked tubes for structural integrity evaluation of SGs. The objective of the present paper is to demonstrate the use of extended finite element method capability of commercially available ABAQUS software, to model SG tubes with preexisting flaws and to estimate their rupture pressures. For the purpose, elastic–plastic finite element models were developed for different SG tubes made from Alloy 600 material. The simulation results were compared with experimental results available from the steam generator tube integrity program (SGTIP) sponsored by the United States Nuclear Regulatory Commission (NRC) and conducted at Argonne National Laboratory (ANL). A reasonable correlation was found between extended finite element model results and experimental results.

  9. Fluting Modes in Transversely Nonuniform Solar Flux Tubes (United States)

    Soler, Roberto


    Magnetohydrodynamic waves of different types are frequently observed in magnetic flux tubes of the solar atmosphere and are often modeled using simple models. In the standard flux tube model made of a straight uniform tube with an abrupt boundary, transverse wave modes are classified according to their azimuthal wavenumber, m. Sausage (m = 0) and kink (m = 1) modes produce pulsations of the cross section and transverse oscillations of tube axis, respectively. Both sausage and kink modes have been observed in the solar atmosphere. Fluting (m≥slant 2) modes produce perturbations that are essentially confined around the boundary of the tube, I.e., they have a strong surface-like character. Unlike sausage and kink modes, the detection of fluting modes remains elusive. Here we show that the inclusion of transverse inhomogeneity in the flux tube model dramatically affects the properties of fluting modes. Even in a thin tube, kink and fluting modes are no longer degenerate in frequency when the tube has a smooth boundary. In addition, fluting modes become heavily damped by resonant absorption in a timescale shorter than the oscillation period. The perturbations loose their global shape and their distinctive surface-like appearance. As a consequence of that, we argue that nonuniform flux tubes with smooth boundaries may not be able to support fluting-like perturbations as coherent, global modes.

  10. Cell Wall Composition, Biosynthesis and Remodeling during Pollen Tube Growth. (United States)

    Mollet, Jean-Claude; Leroux, Christelle; Dardelle, Flavien; Lehner, Arnaud


    The pollen tube is a fast tip-growing cell carrying the two sperm cells to the ovule allowing the double fertilization process and seed setting. To succeed in this process, the spatial and temporal controls of pollen tube growth within the female organ are critical. It requires a massive cell wall deposition to promote fast pollen tube elongation and a tight control of the cell wall remodeling to modify the mechanical properties. In addition, during its journey, the pollen tube interacts with the pistil, which plays key roles in pollen tube nutrition, guidance and in the rejection of the self-incompatible pollen. This review focuses on our current knowledge in the biochemistry and localization of the main cell wall polymers including pectin, hemicellulose, cellulose and callose from several pollen tube species. Moreover, based on transcriptomic data and functional genomic studies, the possible enzymes involved in the cell wall remodeling during pollen tube growth and their impact on the cell wall mechanics are also described. Finally, mutant analyses have permitted to gain insight in the function of several genes involved in the pollen tube cell wall biosynthesis and their roles in pollen tube growth are further discussed.

  11. The Neutron Spectrum in a Uranium Tube

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, E.; Jonsson, E.; Lindberg, M.; Mednis, J.


    A series of experimental and theoretical investigations on neutron spectra in lattice cells has been started at the reactor R1. This report gives the results from the first one of these cells - one with a tube of natural -uranium surrounded by heavy water. In the measurements the cell was placed in the central, vertical channel of the reactor. The neutron spectrum from a lead scatterer in the uranium tube - outer diameter 49.2 mm, inner diameter 28.3 mm - was measured with a fast chopper in the energy region 0.01 to 100 eV. Subsidiary measurements indicated that the spectrum in the beam from the lead piece corresponds to the spectrum of the angular flux integrated over all angles. This correspondence is important for the interpretation of the experimental data. The thermal part of the spectrum was found to deviate significantly from a Maxwellian. However, the deviation is not very large, and one could use a Maxwellian, at least to give a rough idea of the hardness of the spectrum. For the present tube the temperature of this Maxwellian was estimated as 90 to 100 deg C above the moderator temperature (33 deg C). In the joining region the rise of the spectrum towards the thermal part is slower than for the cell boundary spectrum, measured earlier. In the epithermal region the limited resolution of the chopper has affected the measurements at the energies of the uranium resonances. However, the shape of the spectrum on the flanks of the first resonance in {sup 238}U (6.68 eV) has been obtained accurately. In the theoretical treatment the THERMOS code with a free gas scattering model has been used. The energy region was 3.06 - 0.00025 eV. The agreement with the measurements is good for the thermal part - possibly the theoretical spectrum is a little softer than the experimental one. In the joining region the results from THERMOS are comparatively high - probably due to the scattering model used.

  12. Biocide-mediated corrosion of coiled tubing. (United States)

    Sharma, Mohita; An, Dongshan; Liu, Tao; Pinnock, Tijan; Cheng, Frank; Voordouw, Gerrit


    Coiled tubing corrosion was investigated for 16 field water samples (S5 to S20) from a Canadian shale gas field. Weight loss corrosion rates of carbon steel beads incubated with these field water samples averaged 0.2 mm/yr, but injection water sample S19 had 1.25±0.07 mm/yr. S19 had a most probable number of zero acid-producing bacteria and incubation of S19 with carbon steel beads or coupons did not lead to big changes in microbial community composition. In contrast other field water samples had most probable numbers of APB of 102/mL to 107/mL and incubation of these field water samples with carbon steel beads or coupons often gave large changes in microbial community composition. HPLC analysis indicated that all field water samples had elevated concentrations of bromide (average 1.6 mM), which may be derived from bronopol, which was used as a biocide. S19 had the highest bromide concentration (4.2 mM) and was the only water sample with a high concentration of active bronopol (13.8 mM, 2760 ppm). Corrosion rates increased linearly with bronopol concentration, as determined by weight loss of carbon steel beads, for experiments with S19, with filtered S19 and with bronopol dissolved in defined medium. This indicated that the high corrosion rate found for S19 was due to its high bronopol concentration. The corrosion rate of coiled tubing coupons also increased linearly with bronopol concentration as determined by electrochemical methods. Profilometry measurements also showed formation of multiple pits on the surface of coiled tubing coupon with an average pit depth of 60 μm after 1 week of incubation with 1 mM bronopol. At the recommended dosage of 100 ppm the corrosiveness of bronopol towards carbon steel beads was modest (0.011 mm/yr). Higher concentrations, resulting if biocide is added repeatedly as commonly done in shale gas operations, are more corrosive and should be avoided. Overdosing may be avoided by assaying the presence of residual biocide by HPLC

  13. Ototoxic Effects of Irradiation


    Upadhya, I.; Jariwala, N.; Datar, J.


    In this study ototoxic effect of ionizing radiation was studied in 70 ears with minimum follow up of 6 months post radiotherapy. Patients of nasopharyngeal carcinoma and with conductive deafness pre radiotherapy were excluded from the study to eliminate mechanical obstruction that may play role in Eustachian tube dysfunction. We found that Eustachian tube dysfunction and conductive deafness were reversible where as Sensorineural hearing loss was an irreversible effect of radiotherapy. Dose of...

  14. Hydroforming of aluminum tubes for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Xia, C. [Ford Motor Co., Dearborn, MI (United States)


    This power point presentation described the hydroforming process used at the Ford Motor Company with particular focus on aluminium tubes. The process control for design and manufacturing was illustrated in a series of viewgraphs. A comparison was also included of the advantages and disadvantages of hydroforming versus stamping assembly. The advantages of hydroforming are that it reduces tool costs, improves the structural strength and stiffness of the product, has fewer secondary operations, and produces a lighter weight product with reduced scrap. The disadvantage is that hydroforming requires a long cycle time, and may require single sided spot welding. There may also be difficulty in incorporating internal brackets. A comparison of high pressure hydroforming versus pressure sequence hydroforming was also illustrated. 14 figs.


    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Harper, Ph.D.


    Work has begun under three major tasks of this project. With respect to increasing the circumferential strength of a MA956 tube, approximately 60 MA956 rods have been extruded using a 20:1 extrusion ratio and extrusion temperatures of 1000, 1075, 1150, and 1200 C. Also, creep testing is underway for the purpose of determining the ''stress threshold'' curves for this alloy. Regarding joining of the alloy MA956, work has begun on the friction welding, magnetic impulse welding, explosive welding, and transient liquid phase bonding aspects of this project. And finally, material is being prepared for the laboratory fire-side high temperature corrosion tests, with potential gas and deposits for a typical Vision 21 plant being reviewed for final determination of these variables in the test program.

  16. Fallopian tube patency demonstrated at ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, F.; Larsen, C.; Justesen, P.

    Fallopian tube patency was assessed in 24 infertile patients by hysterosalpingography (HSG) and ultrasonographic examination of the pouch of Douglas following transcervical injection of sterile isotonic solution of NaCl. The presence of fluid in the pouch, after the injection, was taken to indicate tubal patency. The results of the HSG and the ultrasonographic diagnosis as to the presence of at least unilateral tubal patency were concordant in 21 patients. Pitfalls consisted of fluid accumulation in periadnexal adhesions, edema in the bowel wall, and spill of the injected saline into a large hydrosalpinx. Ultrasonography is advocated as the initial examination in assessing infertility in young women. If tubal patency is demonstrated, the patient should be recommended a six month trial period, to become pregnant, before invasive procedures are initiated.

  17. Flash photolysis-shock tube studies

    Energy Technology Data Exchange (ETDEWEB)

    Michael, J.V. [Argonne National Laboratory, IL (United States)


    Even though this project in the past has concentrated on the measurement of thermal bimolecular reactions of atomic species with stable molecules by the flash or laser photolysis-shock tube (FP- or LP-ST) method using atomic resonance absorption spectrometry (ARAS) as the diagnostic technique, during the past year the authors have concentrated on studies of the thermal decompositions of selected chlorocarbon molecules. These studies are necessary if the degradation of chlorine containing organic molecules by incineration are to be understood at the molecular level. Clearly, destruction of these molecules will not only involve abstraction reactions, when possible, but also thermal decomposition followed by secondary reactions of the initially formed atoms and radicals. Studies on the thermal decomposition of CH{sub 3}Cl are complete, and the curve-of-growth for Cl-atom atomic resonance absorption has been determined. The new thermal decomposition studies are similar to those already reported for CH{sub 3}Cl.

  18. Direct ophthalmoscopy on YouTube

    DEFF Research Database (Denmark)

    Borgersen, Nanna Jo; Henriksen, Mikael Johannes Vuokko; Konge, Lars


    by evaluating their content and approach to visualization. METHODS: In order to synthesize main themes and points for direct ophthalmoscopy, we formed a broad panel consisting of a medical student, junior and senior physicians, and took into consideration book chapters targeting medical students and physicians...... in general. We then systematically searched YouTube. Two authors reviewed eligible videos to assess eligibility and extract data on video statistics, content, and approach to visualization. Correlations between video statistics and contents were investigated using two-tailed Spearman's correlation. RESULTS......: We screened 7,640 videos, of which 27 were found eligible for this study. Overall, a median of 12 out of 18 points (interquartile range: 8-14 key points) were covered; no videos covered all of the 18 points assessed. We found the most difficulties in the approach to visualization of how to approach...

  19. Glass heat pipe evacuated tube solar collector (United States)

    McConnell, Robert D.; Vansant, James H.


    A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

  20. Claudins in morphogenesis: Forming an epithelial tube. (United States)

    Baumholtz, Amanda I; Gupta, Indra R; Ryan, Aimee K


    The claudin family of tetraspan transmembrane proteins is essential for tight junction formation and regulation of paracellular transport between epithelial cells. Claudins also play a role in apical-basal cell polarity, cell adhesion and link the tight junction to the actin cytoskeleton to exert effects on cell shape. The function of claudins in paracellular transport has been extensively studied through loss-of-function and gain-of-function studies in cell lines and in animal models, however, their role in morphogenesis has been less appreciated. In this review, we will highlight the importance of claudins during morphogenesis by specifically focusing on their critical functions in generating epithelial tubes, lumens, and tubular networks during organ formation.

  1. Buckyball Nucleation of HiPco Tubes (United States)

    Smalley, Richard E.


    The purpose of this innovation is to enhance nucleation of single-wall nanotubes (SWNTs) in the HiPco process, selectively producing 10,10 tubes, something which until now has not been thought possible. This is accomplished by injecting C60, or a derivative of C60, solubilized in supercritical CO2 together with a transition metal carboneal cocatalyst into the HiPco reactor. This is a variant on the supercritical disclosure. C60 has never been used to nucleate carbon nanotubes in the gas phase. C60 itself may not have adequate solubility in supercritical CO2. However, fluorinated C60, e.g., C60F36, is easy to make cheaply and should have much enhanced solubility.

  2. Coulomb flux tube on the lattice (United States)

    Chung, Kristian; Greensite, Jeff


    In Coulomb gauge a longitudinal electric field is generated instantaneously with the creation of a static quark-antiquark pair. The field due to the quarks is a sum of two contributions, one from the quark and one from the antiquark, and there is no obvious reason that this sum should fall off exponentially with distance from the sources. We show here, however, from numerical simulations in pure SU(2) lattice gauge theory, that the color Coulomb electric field does in fact fall off exponentially with transverse distance away from a line joining static quark-antiquark sources, indicating the existence of a color Coulomb flux tube, and the absence of long-range Coulomb dipole fields.

  3. Projectile Balloting Attributable to Gun Tube Curvature

    Directory of Open Access Journals (Sweden)

    Michael M. Chen


    Full Text Available Transverse motion of a projectile during launch is detrimental to firing accuracy, structural integrity, and/or on-board electronics performance of the projectile. One manifest contributing factor to the undesired motion is imperfect bore centerline straightness. This paper starts with the presentation of a deterministic barrel model that possesses both vertical and lateral deviations from centerline in accordance with measurement data, followed by a novel approach to simulating comprehensive barrel centerline variations for the investigation of projectile balloting^1 motions. A modern projectile was adopted for this study. In-bore projectile responses at various locations of the projectile while traveling through the simulated gun tubes were obtained. The balloting was evaluated in both time and frequency domains. Some statistical quantities and the significance were outlined.


    Directory of Open Access Journals (Sweden)

    Abdujafar I. Akaev


    Full Text Available Abstract. Objectives The aim of the research is to find optimal design solutions for the erection of buildings that will ensure their reliability and durability, compliance with environmental requirements, fire resistance and earthquake resistance. In this regard, the task is to determine the advantages and prospects of erecting earthquake resistant buildings from tube concrete constructions, since they are distinct in constructive, technological and economic efficiency when are used as vertical load-bearing struts of high-rise buildings. Method The technique for calculating the strength of normal sections of eccentrically-compressed tube concrete elements uses a nonlinear deformation model, taking into account the joint operation of the steel shell and the concrete core under the conditions of triaxial compression. Results In the article the review of the newest world experience of using tube concrete as vertical load-bearing structures for public facilities from the standpoint of earthquake resistant construction is given. The international practices of public facility construction ranging in height from 100 to 600 m with the use of tube concrete technology, including regions with dangerous natural and man-made conditions, have been studied. The structural, operational and technological advantages and disadvantages of tube concrete technology are analysed. Methods for calculating the strength of concrete tube elements in the case of central compression are considered: according to the so-called deformation theory, the state of total destruction of both concrete and tube fluidity attained at maximum pressure are indicated by the beginning of "tube flow on the longitudinal axis". The advantages and disadvantages of both methods are shown. Factors constraining the introduction and wider application of tube concrete constructions in Russia are considered. Conclusion While the advantages of concrete tube constructions in their extensive

  5. Which sample tube should be used for routine glucose determination? (United States)

    Bonetti, Graziella; Cancelli, Vanessa; Coccoli, Giulio; Piccinelli, Giorgio; Brugnoni, Duilio; Caimi, Luigi; Carta, Mariarosa


    Glucose is one of the most frequently requested analytes in clinical laboratory. Blood glucose analysis is affected from in vitro glycolysis. In order to determine the most suitable blood collection tube for this purpose we have compared different tubes: sodium fluoride, lithium heparin, sodium fluoride/citrate buffer containing tubes and serum with clot activator tube for the measurement of glucose when the tube has been kept at room temperature (RT) for up to 4h. Venous blood was collected from 49 healthy volunteers into Sarstedt S-Monovettes for glucose analysis. Reference plasma glucose was determined in a lithium heparin tube and immediately placed in an ice/water slurry. Within 10min it was centrifuged at 4°C and plasma was separated from the blood cells. Samples have been preserved at RT for 1, 2 and 4h after drawing. Glucose has been determined using a hexokinase method. Glucose levels tested in a serum with clot activator tube, in lithium heparin and in sodium fluoride/sodium EDTA tubes when compared with lithium-heparin reference plasma did not meet the desirable bias for glucose (±1.8%) when kept at RT for up to 4h. GlucoEXACT tubes, when corrected by the Sarsted recommended factor of 1.16, showed a mean (95% CI) bias of +0.96% (0.45-1.47) at 1h, +1.40% (0.88-1.93) at 2h and +0.95% (0.44-1.46) at 4h, reaching the analytical goal for the desirable bias. Samples collected into GlucoEXACT tubes containing sodium fluoride/citrate buffer liquid mixture are equivalent to those collected in reference plasma tubes avoiding glycolysis completely and within a 4h delay in plasma separation. Copyright © 2015 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

  6. Natural vibration frequencies of horizontal tubes partially filled with liquid (United States)

    Santisteban Hidalgo, Juan Andrés; Gama, Antonio Lopes; Moreira, Roger Matsumoto


    This work presents an experimental and numerical study on the flexural vibration of horizontal circular tubes partially filled with liquid. The tube is configured as a free-free beam with attention being directed to the case of small amplitudes of transverse oscillation whereas the axial movements of the tube and liquid are disregarded. At first vertical and horizontal polarizations of the flexural tube are investigated experimentally for different amounts of filling liquid. In contrast with the empty and fully-filled tubes, it is observed that natural frequencies of the vertical and horizontal polarizations are different due to asymmetry induced by the liquid layer, which acts like an added mass. Less mass of liquid is added to the tube when oscillating horizontally; as a consequence, eigenfrequencies for the horizontal polarization are found to be greater than the case of the vertically polarized tube. A simple method to calculate the natural vibration frequencies using coefficients of added mass of liquid is proposed. It is shown that the added mass coefficient increases with the liquid's level and viscosity. At last a numerical investigation of the interaction between the liquid and the tube is carried out by solving in two-dimensions the full Navier-Stokes equations via a finite volume method, with the free-surface flow being modeled with a homogeneous multiphase Eulerian-Eulerian fluid approach. Vertical and horizontal polarizations are imposed to the tube with pressure and shear stresses being determined numerically to assess the liquid's forcing onto the tube's wall. The coefficient of added mass of liquid is then estimated by the ratio between the resulting force and the acceleration imposed to the wall. A good agreement is found between experimental and numerical results, especially for the horizontally oscillating tube. It is also shown that viscosity can noticeably affect the added mass coefficients, particularly at low filling levels.

  7. The INGVterremoti channel on YouTube

    Directory of Open Access Journals (Sweden)

    Alessandro Amato


    Full Text Available n February 2010, we launched an experimental scientific video channel on YouTube (, to improve our communication strategy for earthquake risk and preparedness. The main goals of this initiative were to inform people of the ongoing seismic activity in Italy and around the World, to communicate the results of scientific research in seismology, and to increase the knowledge of seismic hazard of the people. To date, after almost two years from the start, we have published 52 original videos on YouTube, through the collaboration of many researchers at the Istituto Nazionale di Geofisica e Vulcanologia (INGV. The videos are organized into eight play lists: (i earthquakes in Italy; (ii earthquakes worldwide; (iii the 2009 L’Aquila, Italy, earthquake; (iv ongoing seismic activity; (v tsunami; (vi earthquake prediction; (vii seismic hazard; and (viii May 11 2011 (when a major earthquake was predicted to hit Rome. To date, the total number of views is over 466,000, with two peaks of more than 20,000/day after the Tohoku, Japan, earthquake (March 2011 and before the presumed prediction of a major earthquake to hit Rome on May 11, 2011. The most popular videos (6 have been viewed more than 20,000 times, with a maximum of over 67,000. We think that this initiative has increased people’s knowledge and awareness of seismic risk, although at the moment the outreach is limited only to a specific (but growing target of citizens. In the future, we will try to improve the technical aspects of our video communication, and we will try to broaden our audience. We have learned that when specific earthquakes occur (or even when there are unfounded predictions about upcoming seismic events this is when the attention is highest, which represent the best occasions to move forward towards improved risk communication strategies.

  8. Progress in CPI Microwave Tube Development (United States)

    Wright, Edward L.; Bohlen, Heinz


    CPI continues its role as a leading supplier of state-of-the-art, high-power microwave tubes; from linear beam, velocity- and density-modulated devices, to high frequency gyro-devices. Klystrons are the device-of-choice for many high-power microwave applications, and can provide multi-megawatts to multi-kilowatts of power from UHF to W-band, respectively. A number of recent and on-going developments will be described. At UHF frequencies, the inductive output tube (IOT) has replaced the klystron for terrestrial NTSC and HDTV broadcast, due to its high efficiency and linearity, and is beginning to see use in scientific applications requiring 300 kW or less. Recent advances have enabled use well into L-band. CPI has developed a number of multiple-beam amplifiers. The VKL-8301 multiple-beam klystron (MBK) was built for the TESLA V/UV and x-ray FEL projects, and is a candidate RF source for the International Linear Collider (ILC). We have also contributed to the development of the U.S. Naval Research Laboratory (NRL) high-power fundamental-mode S-band MBK. The VHP-8330B multiple-beam, high-order mode (HOM) IOT shows great promise as a compact, CW UHF source for high power applications. These topics will be discussed, along with CPI's development capabilities for new and novel applications. Most important is our availability to provide design and fabrication services to organizations requiring CPI's manufacturing and process control infrastructure to build and test state-of-the-art devices.

  9. The pulsed-gas tube, statement and perspectives; Le tube a gaz pulse, bilan et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Domblides, J.P.; Neveau, P.; Castaing-Lasvignottes, J. [Laboratoire du froid du CNAM, 75 - Paris (France)


    The pulsed-gas tube has several advantages with respect to the other types of cryo-refrigerating machineries classically used to reach very low temperatures: no mobile parts moving at very low temperatures and no vibrations. However, this system discovered in 1963 is handicapped by its lack of power and by its low energy efficiency. Todays researches about pulsed-gas tubes concern: the technical adaptation of existing systems to applications where its simplicity makes it competitive, the improvement of its energetic performances (refrigerating power and range of temperatures of use), and the development of numerical models in order to better understand the functioning of the system and to optimize it. (J.S.) 19 refs.

  10. Flow chemistry: intelligent processing of gas-liquid transformations using a tube-in-tube reactor. (United States)

    Brzozowski, Martin; O'Brien, Matthew; Ley, Steven V; Polyzos, Anastasios


    reactive gas in a given reaction mixture. We have developed a tube-in-tube reactor device consisting of a pair of concentric capillaries in which pressurized gas permeates through an inner Teflon AF-2400 tube and reacts with dissolved substrate within a liquid phase that flows within a second gas impermeable tube. This Account examines our efforts toward the development of a simple, unified methodology for the processing of gaseous reagents in flow by way of development of a tube-in-tube reactor device and applications to key C-C, C-N, and C-O bond forming and hydrogenation reactions. We further describe the application to multistep reactions using solid-supported reagents and extend the technology to processes utilizing multiple gas reagents. A key feature of our work is the development of computer-aided imaging techniques to allow automated in-line monitoring of gas concentration and stoichiometry in real time. We anticipate that this Account will illustrate the convenience and benefits of membrane tube-in-tube reactor technology to improve and concomitantly broaden the scope of gas/liquid/solid reactions in organic synthesis.

  11. Propagation of nonlinear, radiatively damped longitudinal waves along magnetic flux tubes in the solar atmosphere (United States)

    Herbold, G.; Ulmschneider, P.; Spruit, H. C.; Rosner, R.


    For solar magnetic flux tubes three types of waves are compared: longitudinal MHD tube waves, acoustic tube waves propagating in the same tube geometry but with rigid walls and ordinary acoustic waves in plane geometry. It is found that the effect of the distensibility of the tube is small and that longitudinal waves are essentially acoustic tube waves. Due to the tube geometry there is considerable difference between longitudinal waves or acoustic tube waves and ordinary acoustic waves. Longitudinal waves as well as acoustic tube waves show a smaller amplitude growth, larger shock formation heights, smaller mean chromospheric temperature but a steeper dependence of the temperature gradient on wave period.

  12. Endotracheal tube connector defect causing airway obstruction in an ...

    African Journals Online (AJOL)

    Acase of difficulty was recently encountered in ventilating an anaesthetised infant after intubating the trachea with size 3.5 mm endotra- cheal tube. It was found that the problem had occurred due to a manufacturing defect in the endotracheal tube connector where the connector was abnormally tapered and had an ...

  13. Macroscopic and microscopic changes in the fallopian tube after ...

    African Journals Online (AJOL)

    A total of 43 patients who had undergone laparoscopic tubal occl usion by means of bipolar cauterization underwent bilateral salpingectomy 6- 30 months later. The macroscopic and microscopic changes in the fallopian tubes are described. Although 35 patients appeared to have occluded tubes on macro-scopic ...

  14. Deadly pressure pneumothorax after withdrawal of misplaced feeding tube

    DEFF Research Database (Denmark)

    Andresen, Erik Nygaard; Frydland, Martin; Usinger, Lotte


    , but our patient died less than an hour after withdrawal. The autopsy report stated that cause of death was tension pneumothorax, which developed following withdrawal of the misplaced feeding tube. CONCLUSIONS: The indications for insertion of nasogastric feeding tubes are many and the procedure...

  15. CFD investigation of flow through internally riffled boiler tubes

    DEFF Research Database (Denmark)

    Rasmussen, Christian; Houbak, Niels; Sørensen, Jens Nørkær


    In this paper we show how to model the swirling flow in an internally riffled boiler tube. The flow field is visualized and the results are compared with measurements.......In this paper we show how to model the swirling flow in an internally riffled boiler tube. The flow field is visualized and the results are compared with measurements....

  16. Creep analysis of boiler tubes by fem | Taye | Zede Journal

    African Journals Online (AJOL)

    In this paper an analysis is developed for the determination of creep deformation of an axisymmetric boiler tubes subjected to axisymmetric loads. The stresses and the permanent strains at a particular time and at the steady state condition, resulting from loading of the tube under constant internal pressure and elevated ...

  17. Neural tube defects and folate: case far from closed.

    NARCIS (Netherlands)

    Blom, H.J.; Shaw, G.M.; Heijer, M. den; Finnell, R.H.


    Neural tube closure takes place during early embryogenesis and requires interactions between genetic and environmental factors. Failure of neural tube closure is a common congenital malformation that results in morbidity and mortality. A major clinical achievement has been the use of

  18. A Tool for Monitoring of YouTube Content

    DEFF Research Database (Denmark)

    Lashari, Intzar Ali; Wiil, Uffe Kock


    in abundance from social media is difficult. This paper describes a new tool that can collect, monitor, and mine data from YouTube. The tool is part of a larger framework aimed at monitoring various social media including Facebook, Twitter, and YouTube. A specific case focusing on “Islamic Jihad Holy War...

  19. YouTube as research tool–Three approaches

    NARCIS (Netherlands)

    Konijn, E.A.; Veldhuis, J.; Plaisier, X.S.


    The present paper provides empirical data to support the use of social media as research environment. YouTube was chosen as a most appropriate format to target adolescents in experimental and cross-sectional designs given its popularity as well as its plasticity. We uniquely applied the YouTube

  20. YouTube and Academic Libraries: Building a Digital Collection (United States)

    Cho, Allan


    Although still a relatively new technology with less than 10 years of history, YouTube's extensive reach and integration in mainstream society as well as lifelong learning habits of online users cannot be understated. This article examines how the YouTube collection at the University of British Columbia Library's Irving K. Barber Learning Centre…

  1. LHC tubes near the end of their journey

    CERN Multimedia


    Production of the heat exchanger tubes, which will cool down the LHC magnets, and of the cold bore tubes, in which the proton beams will circulate, is due to be completed around the end of 2004. These essential components of the LHC magnets are receiving their finishing touches at CERN.

  2. Flow distribution and tube vibration in heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, H.L.


    A project was initiated to study flow distribution and tube vibration in heat exchangers. An experimental program was carried out on a full-size heat exchanger in four test phases of parametric study. The flow induced vibration data were used to quantify and develop non-intrusive vibration monitoring techniques for online problem evaluation and to study the influence of design features and conditions on the vibration. The in-tube vibration data obtained have shown that the vibroacoustic and microphone monitoring techniques to be reliable and accurate methods for the detection of tube impacting in an operating heat exchanger. Development of work on the use of a two-accelerator vibroacoustic technique for the location of impacting zones in a bundle showed promise and is currently being employed in the field. The in-tube vibration data have demonstrated the effects that changes in the design of a bundle can have on tube vibration in that bundle. These results indicate that an important factor in bundle design is the local flow distribution in areas of high vibration susceptibility. The in-tube data have demonstrated that tubes in zones other than the inlet region can be susceptible to a form of periodic resonant excitation. This observation has implications for cases where flow reduction is implemented to avoid an instability problem. Such a reduction could bring the tube bundle into a flow regime where it is susceptible to the resonant excitation. 10 refs., 55 figs., 4 tabs.

  3. Investigation on mechanical behavior of filament-wound CFRP tubes (United States)

    Zhang, Liangquan; Li, Hui


    Firstly, two types of CFRP tubes are designed using the filament-wound forming technology. These tubes are winded by carbon fibers with a filament winding pattern of [(900/00)2]S. The compression and tensile test are also carried out to investigate the stress-strain relationship, ultimate strength and macroscopic failure mode of the former CFRP tube. The results demonstrate that the former CFRP tube has a much larger ultimate tensile stress and strain than compressive stress and strain. However, the elastic modules of CFRP tubes under tension and compression are similar and the failure mode of these CFRP tubes is brittle under compression and tension. Secondly, the stress and strain analysis method of filament-wound CFRP tube is investigated according to anisotropic elasticity theory and lamination theory of composite material. Then, the strength of carbon-fiber-reinforced plastic tubes is obtained. In addition, the comparison of theoretical analysis results and experimental results shows that the theoretical analysis results are reliable.

  4. Spinal Neural Tube Defects in Lagos University Teaching Hospital ...

    African Journals Online (AJOL)

    Background: The incidence of neural tube defects is known to vary among regions. Very little has been reported about the incidence in Sub-Saharan Africa except for the general impression that the prevalent rates are low. Objective: To determine the profile of patients presenting with neural tube defects in Lagos , Nigeria

  5. pen Neural Tube Defects at the National Hospital,

    African Journals Online (AJOL)

    Background: Neural tube defect is the most common congenital abnormality of the central nervous system. Objectives: To document the clinical patterns and neonatal outcome of babies with open neural tube defects at the National Hospital, .... prevalence of these malformations in the region. This is because there are two ...

  6. Maxwell's Demon in the Ranque-Hilsch Vortex Tube (United States)

    Liew, R.; Zeegers, J. C. H.; Kuerten, J. G. M.; Michalek, W. R.


    A theory was developed that explains energy separation in a vortex tube, known as one of the Maxwellian demons. It appears that there is a unique relation between the pressures in the exits of the vortex tube and its temperatures. Experimental results show that the computed and measured temperatures are in very good agreement.

  7. Maxwell's demon in the Ranque-Hilsch vortex tube


    Liew, R Raoul; Zeegers, JCH Jos; Kuerten, JGM Hans; Michalek, WR Wiktor


    A theory was developed that explains energy separation in a vortex tube, known as one of the Maxwellian demons. It appears that there is a unique relation between the pressures in the exits of the vortex tube and its temperatures. Experimental results show that the computed and measured temperatures are in very good agreement.

  8. Droplet behaviour in a Ranque-Hilsch vortex tube

    NARCIS (Netherlands)

    Liew, R.; Michalek, W.R.; Zeegers, J.C.H.; Kuerten, Johannes G.M.

    The vortex tube is an apparatus by which compressed gas is separated into cold and warm streams. Although the apparatus is mostly used for cooling, the possibility to use the vortex tube as a device for removing non-desired condensable components from gas mixtures is investigated. To give first

  9. Properties of Flux Tubes and the Relation with Solar Irradiance ...

    Indian Academy of Sciences (India)

    At the solar surface the magnetic field is bundled into discrete elements of concentrated flux, often referred to as magnetic flux tubes, which cover only a small fraction of the solar surface. Flux tubes span a whole spectrum of sizes, ranging from sunspots to features well below the best currently obtainable spatial resolution.

  10. Preventing neural tube defects in Europe : A missed opportunity

    NARCIS (Netherlands)

    Busby, A; Armstrong, B; Dolk, H; Armstrong, N; Haeusler, M; Berghold, A; Gillerot, Y; Baguette, A; Gjerga, R; Barisic, [No Value; Christiansen, M; Goujard, J; Steinbicker, [No Value; Rosch, C; McDonnell, R; Scarano, G; Calzolari, E; Neville, A; Cocchi, G; Bianca, S; Gatt, M; De Walle, H; Braz, P; Latos-Bielenska, A; Gener, B; Portillor, [No Value; Addor, MC; Abramsky, L; Ritvanen, A; Robert-Gnansia, E; Daltveit, AK; Aneren, G; Olars, B; Edwards, G


    Each year, more than 4500 pregnancies in the European Union are affected by neural tube defects (NTD). Unambiguous evidence of the effectiveness of peri conceptional folic acid in preventing the majority of neural tube defects has been available since 1991. We report on trends in the total

  11. Pneumonia Frequencies with Different Enteral Tube Feeding Access Sites. (United States)

    Taylor, Henry M.


    Over a 24-month period, 25 adults with mental retardation being fed via a gastrostomy tube experienced 40 cases of pneumonia during 508 person-months of observations, whereas 5 individuals being fed via a jejunostromy tube did not experience any pneumonia during 96 person-months of observation. (Contains references.) (Author/CR)

  12. Pneumothorax Following Feeding Tube Placement: Precaution and Treatment

    Directory of Open Access Journals (Sweden)

    Morteza Zahmatkesh


    Full Text Available Nasojejunal feeding tubes are being used at an increased frequency, but it is not without complications that could be life-threatening. We report two cases of pneumothorax following small-bore feeding tube insertion into the pleural cavity, resulting in pneumothorax. We further discuss the potential measures that can be taken to prevent and treat this serious complication.

  13. Experimental studies on the flow through soft tubes and channels

    Indian Academy of Sciences (India)

    Keywords. Laminar-turbulent transition; soft tubes/channels; hydrodynamic stability; transition; turbulence; internal flows. Abstract. Experiments conducted in channels/tubes with height/diameter less than 1 mm with soft walls made of polymer gels show that the transition Reynolds number could be significantly lower than ...

  14. KevJumba and the Adolescence of YouTube (United States)

    Saul, Roger


    This article considers the significance of YouTube as a pedagogical space from which young people can play participatory roles as theorists in their own constructions as popular cultural subjects. Drawing upon the public profile of "KevJumba," a teenager who makes videos of himself on YouTube, the article suggests that representational practices…

  15. YouTube: An Emerging Tool in Anatomy Education (United States)

    Jaffar, Akram Abood


    The use of online social networks in medical education can remodel and enhance anatomy teaching and learning; one such network is the video-sharing site YouTube. Limited research in the literature exists on the use of YouTube as a platform for anatomy education. The aim of this study is to assess student's perceptions and patterns of usage of this…

  16. Heat transfer and fluid friction in bundles of twisted tubes (United States)

    Dzyubenko, B. V.; Dreitser, G. A.


    The results of heat-transfer and friction studies in bundles of twisted tubes and rods with spiral wire-wrap spacers are analyzed, and recommendations are given for calculating the heat-transfer coefficient in heat exchangers using twisted tubes.

  17. Automated liquid-helium transfer tube lifting system (United States)

    Kato, Kiyonori; Suzui, Mitsukazu


    An automatic liquid-helium transfer tube lifting system has been developed, in which the transfer tube can be raised or lowered very slowly by remote control. This system relieves the operator of considerable manual labor, and protects the O-ring seals from damage at low temperature.

  18. 46 CFR 151.03-49 - Sounding tube. (United States)


    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sounding tube. 151.03-49 Section 151.03-49 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-49 Sounding tube. This is an unperforated...

  19. Uncovering hidden treasures in pollen tube growth mechanics

    NARCIS (Netherlands)

    Zonia, L.; Munnik, T.


    The long-standing model of tip growth in pollen tubes considers that exocytosis and growth occur at the apex and that the pool of very small vesicles in the apical dome contains secretory (exocytic) vesicles. However, recent work on vesicle trafficking dynamics in tobacco pollen tubes shows that

  20. Infant feeding tube as urinary tract stent | Ekeke | Port Harcourt ...

    African Journals Online (AJOL)

    Background: The infant feeding tube is a cheap and readily available device with many uses in the urinary tract. Many types of stents are available in the market but among other factors, cost and affordability limit their use in developing countries and remote areas. Aim: To document experience with infant feeding tubes as ...