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Sample records for abrasive feed tube

  1. Tube Feedings.

    ERIC Educational Resources Information Center

    Plummer, Nancy

    This module on tube feedings is intended for use in inservice or continuing education programs for persons who work in long-term care. Instructor information, including teaching suggestions and a listing of recommended audiovisual materials and their sources appear first. The module goal and objectives are then provided. A brief discussion follows…

  2. Feeding Tubes

    MedlinePlus

    ... of placement carefully with your physician and surgeon. Methods of Feeding Enteral feeding means the gastrointestinal (digestive) ... unable to absorb nutrients from enteral feeds. This method of feeding requires a central intravenous line. A ...

  3. Tube Feeding Transition Plateaus

    ERIC Educational Resources Information Center

    Klein, Marsha Dunn

    2007-01-01

    The journey children make from tube feeding to oral feeding is personal for each child and family. There is a sequence of predictable plateaus that children climb as they move toward orally eating. By better understanding this sequence, parents and children can maximize the development, learning, enjoyment and confidence at each plateau. The…

  4. Enteral Tube Feeding and Pneumonia

    ERIC Educational Resources Information Center

    Gray, David Sheridan; Kimmel, David

    2006-01-01

    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…

  5. Gastrostomy feeding tube - bolus

    MedlinePlus

    ... jaw muscles. Feeding Your Child With the Gravity Method Your provider will show you the best way ... the button. Feeding Your Child With the Syringe Method Your provider will teach you the best way ...

  6. Gastroenteric tube feeding: Techniques, problems and solutions

    PubMed Central

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

    2014-01-01

    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

  7. Laparoscopic insertion of the Moss feeding tube.

    PubMed

    Albrink, M H; Hagan, K; Rosemurgy, A S

    1993-12-01

    Placement of enteral feeding tubes is an important part of a surgeon's skill base. Surgical insertion of feeding tubes has been performed safely for many years with very few modifications. With the recent surge in interest and applicability of other laparoscopic procedures, it is well within the skills of the average laparoscopic surgeon to insert feeding tubes. We describe herein a simple technique for the insertion of the Moss feeding tube. The procedure described has a minimum of invasion, along with simplicity, safety, and accuracy.

  8. Medication administration through enteral feeding tubes.

    PubMed

    Williams, Nancy Toedter

    2008-12-15

    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

  9. Abrasive blast cleaning method for the renewal of worn-out acceleration tubes

    NASA Astrophysics Data System (ADS)

    Bartha, L.; Koltay, E.; Mórik, Gy.

    1996-04-01

    The degradation of the electrical properties of acceleration tubes emerging with performance time is known to be assigned mainly to impurities and surface breakdown tracks appearing on the inner surface of the insulators. Consequently, a radical treatment for removing the surface layer may result in a renewal of the tube. An abrasive blast cleaning procedure has been used on a set of worn-out acceleration tube units. The cleaned tube exhibited its original electrical characteristics and it has been used for more than 4000 h of operation up to the maximum rated voltage of our 5 MV electrostatic accelerator without any observable degradation. XRF and PIXE analytical measurements performed on used and blast-treated insulators as well as on electrode and pump oil samples reveal the contribution of elementary processes in the acceleration tube to the ageing of the tube and indicate the effectness of the blasting process used for the re-establishment of clean surface conditions.

  10. Is tube feeding futile in advanced dementia?

    PubMed Central

    Lynch, Matthew C.

    2016-01-01

    It is controversial whether tube feeding in people with dementia improves nutritional status or prolongs survival. Guidelines published by several professional societies cite observational studies that have shown no benefit and conclude that tube feeding in patients with advanced dementia should be avoided. However, all studies on tube feeding in dementia have major methodological flaws that invalidate their findings. The present evidence is not sufficient to justify general guidelines. Patients with advanced dementia represent a very heterogeneous group, and evidence demonstrates that some patients with dementia benefit from tube feeding. However, presently available guidelines make a single recommendation against tube feeding for all patients. Clinicians, patients, and surrogates should be aware that the guidelines and prior commentary on this topic tend both to overestimate the strength of evidence for futility and to exaggerate the burdens of tube feeding. Shared decision making requires accurate information tailored to the individual patient's particular situation, not blanket guidelines based on flawed data. Lay Summary: Many doctors believe that tube feeding does not help people with advanced dementia. Scientific studies suggest that people with dementia who have feeding tubes do not live longer or gain weight compared with those who are carefully hand fed. However, these studies are not very helpful because of flaws in design, which are discussed in this article. Guidelines from professional societies make a blanket recommendation against feeding tubes for anyone with dementia, but an individual approach that takes each person's situation into account seems more appropriate. Patients and surrogates should be aware that the guidelines on this topic tend both to underestimate the benefit and exaggerate the burdens of tube feeding. PMID:27833208

  11. [Enteral nutrition: drug administration via feeding tube].

    PubMed

    Behnken, I; Gaschott, T; Stein, J

    2005-11-01

    Enteral nutrition support via a feeding tube is a preferred and broadly applied way of artificial nutrition in patients who cannot take up orally an adequate amount of nutrients. These patients often need simultaneous drug therapy as well. Thus, there is a high risk of drug-nutrient interactions. Although enteral nutrition is commonly used there is a lack of awareness and knowledge about the appropriate handling and drug administration via the feeding tube. On the one hand, drug-nutrient interactions can lead to clogging of the tube, on the other hand, the change in bioavailability of the drug can have a direct effect on the therapeutic effort. To optimise safety and efficacy of drug therapy in patients with feeding tubes, some basic rules have been set up.

  12. Feeding tube replacement: not always that simple!

    PubMed Central

    Lederman, Alex; Coelho da Rocha, Ricardo Frank; Lourenção, Rodrigo Montenegro

    2015-01-01

    Although surgical gastrostomy is not a technically troublesome surgery, the procedure may be accompanied by unfavorable outcomes. Most complications occur early in the post-operative period and include feeding tube dislodgment, stomal infection, peritonitis, and pneumonia. The authors report the case of an 83-year-old man who underwent a surgical gastrostomy because of a swallowing disorder after an ischemic stroke. Nine months after the procedure, the feeding tube dislodged and a new tube was inserted with a certain delay and with some difficulty, causing a false path and consequently an intrabdominal abscess after diet infusion. The outcome was fatal. The authors call attention for meticulous care with the insertion of feeding tubes and advise the performance of imaging control to assure its precise positioning. PMID:26484325

  13. Survival period after tube feeding in bedridden older patients.

    PubMed

    Kosaka, Yoichi; Nakagawa-Satoh, Takuma; Ohrui, Takashi; Fujii, Masahiko; Arai, Hiroyuki; Sasaki, Hidetada

    2012-04-01

    We prospectively studied survival periods after tube feeding. Participants were 163 bedridden older patients suffering from dysphagia. A wide range of survival periods after tube feeding were observed within half a year without tube feeding after being bedridden. After this initial period, survival periods after tube feeding were limited to approximately half a year. Survival periods after tube feeding were positively proportional to the length of time patients were free from pneumonia after tube feeding. After tube feeding, patients died from pneumonia within half a year, and the frequency of pneumonia was 3.1 ± 2.7 times (mean ± SD) before death. Survival periods after tube feeding for less than 1 year were primarily determined by being bedridden for more than half a year without tube feeding and once pneumonia occurred; patients who were tube fed did not survive for more than half a year. © 2012 Japan Geriatrics Society.

  14. Enteral tube feeding for cystic fibrosis.

    PubMed

    Conway, S P; Morton, A; Wolfe, S

    2008-04-16

    Enteral tube feeding is routinely used in many cystic fibrosis centres when weight for height percentage is less than 85%, when there has been weight loss for longer than a two-month period or when there has been no weight gain for two to three months (under five years old) or for six months (over five years old). To examine the evidence that in people with cystic fibrosis supplemental enteral tube feeding improves nutritional status, respiratory function, and quality of life without significant adverse effects. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also contacted the companies that market enteral feeds and reviewed their databases. Date of the most recent search of the Group's Cystic Fibrosis Trials Register: November 2007. All randomised controlled trials comparing supplemental enteral tube feeding for one month or longer with no specific intervention in people with cystic fibrosis. Thirteen trials were identified by the search; however, none were eligible for inclusion in this review. There are no trials included in this review. Supplemental enteral tube feeding is widely used throughout the world to improve nutritional status in people with cystic fibrosis. The methods mostly used, nasogastric or gastrostomy feeding, are invasive, expensive, and may have a negative effect on self-esteem and body image. Reported use of enteral tube feeding suggests that it results in nutritional and respiratory improvement and it is disappointing that their efficacy has not been fully assessed by randomised controlled trials. With the more frequent recommendations to use enteral tube feeding as an early rather than a late intervention, this systematic review identifies the need for a multicentre, randomised controlled trial assessing both efficacy and possible

  15. Compounded Apixaban Suspensions for Enteral Feeding Tubes.

    PubMed

    Caraballo, Maria L; Donmez, Seda; Nathan, Kobi; Zhao, Fang

    2017-07-01

    Objective: There is limited information on compounded apixaban formulations for administration via enteral feeding tubes. This study was designed to identify a suitable apixaban suspension formulation that is easy to prepare in a pharmacy setting, is compatible with commonly used feeding tubes, and has a beyond-use date of 7 days. Methods: Apixaban suspensions were prepared from commercially available 5-mg Eliquis tablets. Several vehicles and compounding methods were screened for ease of preparation, dosage accuracy, and tube compatibility. Two tubing types, polyurethane and polyvinyl chloride, with varying lengths and diameters, were included in the study. They were mounted on a peg board during evaluation to mimic the patient body position. A 7-day stability study of the selected formulation was also conducted. Results: Vehicles containing 40% to 60% Ora-Plus in water all exhibited satisfactory flowability through the tubes. The mortar/pestle compounding method was found to produce more accurate and consistent apixaban suspensions than the pill crusher or crushing syringe method. The selected formulation, 0.25 mg/mL apixaban in 50:50 Ora-Plus:water, was compatible with both tubing types, retaining >98% drug in posttube samples. The stability study also confirmed that this formulation was stable physically and chemically over 7 days of storage at room temperature. Conclusions: A suitable apixaban suspension formulation was identified for administration via enteral feeding tubes. The formulation consisted of 0.25 mg/mL apixaban in 50:50 Ora-Plus:water. The stability study results supported a beyond-use date of 7 days at room temperature.

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

    DTIC Science & Technology

    2017-06-01

    other documentation. TITLE: Development and Technology Transfer of the Syncro Blue Tube (Gabriel) Magnetically Guided Feeding Tube REPORT DOCUMENTATION...TITLE AND SUBTITLE Development and Technology Transfer of the Syncro Blue Tube (Gabriel) Magnetically Guided Feeding Tube 5a. CONTRACT NUMBER W81XWH-09-2...Technical Abstract: Further Development and Technology Transfer of the Syncro BLUETUBE™ (Gabriel) Magnetically Guided Feeding Tube. New Primary

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

    PubMed

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

    2017-06-01

    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 activities and they lack oral skills. Tube dependency has health-, psychosocial-, and economy-related consequences. Therefore, the transition to oral feeding is of great importance. However, this transition can be very difficult and needs a multidisciplinary approach. Most studies for treatment of tube dependency are based on behavioral interventions, such as family therapy, individual behavior therapy, neuro-linguistic programming, and parental anxiety reduction. Furthermore, oral motor therapy and nutritional adjustments can be helpful in tube weaning. The use of medication has been described in the literature. Although mostly chosen as the last resort, hunger-inducing methods, such as the Graz-model and the Dutch clinical hunger provocation program, are also successful in weaning children off tube feeding. The transition from tube to oral feeding is important in tube-dependent children but can be difficult. We present an overview for the prevention and treatment of tube dependency. What is known: • Longer periods of tube feeding can lead to tube dependency. • Tube weaning can be very difficult. What is new: • Weaning as soon as possible and therefore referral to a multidisciplinary team are recommended. • An overview of treatment options for tube dependency is presented in this article.

  18. An anthology of advances in enteral tube feeding formulations.

    PubMed

    Campbell, Sheila M

    2006-08-01

    This article summarizes several major advances in tube feeding formulas marketed in the United States. It traces the progress in tube feeding formulas, starting with blenderized formulas to commercially available intact-nutrient formulas and culminating in the introduction of the concept of immunonutrition. The impact of packaging is also described.

  19. The feeding tube of cyst nematodes: characterisation of protein exclusion.

    PubMed

    Eves-van den Akker, Sebastian; Lilley, Catherine J; Ault, James R; Ashcroft, Alison E; Jones, John T; Urwin, Peter E

    2014-01-01

    Plant parasitic nematodes comprise several groups; the most economically damaging of these are the sedentary endoparasites. Sedentary endoparasitic nematodes are obligate biotrophs and modify host root tissue, using a suite of effector proteins, to create a feeding site that is their sole source of nutrition. They feed by withdrawing host cell assimilate from the feeding site though a structure known as the feeding tube. The function, composition and molecular characteristics of feeding tubes are poorly characterised. It is hypothesised that the feeding tube facilitates uptake of host cell assimilate by acting as a molecular sieve. Several studies, using molecular mass as the sole indicator of protein size, have given contradictory results about the exclusion limits of the cyst nematode feeding tube. In this study we propose a method to predict protein size, based on protein database coordinates in silico. We tested the validity of these predictions using travelling wave ion mobility spectrometry--mass spectrometry, where predictions and measured values were within approximately 6%. We used the predictions, coupled with mass spectrometry, analytical ultracentrifugation and protein electrophoresis, to resolve previous conflicts and define the exclusion characteristics of the cyst nematode feeding tube. Heterogeneity was tested in the liquid, solid and gas phase to provide a comprehensive evaluation of three proteins of particular interest to feeding tube size exclusion, GFP, mRFP and Dual PI. The data and procedures described here could be applied to the design of plant expressed defence compounds intended for uptake into cyst nematodes. We also highlight the need to assess protein heterogeneity when creating novel fusion proteins.

  20. The Feeding Tube of Cyst Nematodes: Characterisation of Protein Exclusion

    PubMed Central

    Eves-van den Akker, Sebastian; Lilley, Catherine J.; Ault, James R.; Ashcroft, Alison E.; Jones, John T.; Urwin, Peter E.

    2014-01-01

    Plant parasitic nematodes comprise several groups; the most economically damaging of these are the sedentary endoparasites. Sedentary endoparasitic nematodes are obligate biotrophs and modify host root tissue, using a suite of effector proteins, to create a feeding site that is their sole source of nutrition. They feed by withdrawing host cell assimilate from the feeding site though a structure known as the feeding tube. The function, composition and molecular characteristics of feeding tubes are poorly characterised. It is hypothesised that the feeding tube facilitates uptake of host cell assimilate by acting as a molecular sieve. Several studies, using molecular mass as the sole indicator of protein size, have given contradictory results about the exclusion limits of the cyst nematode feeding tube. In this study we propose a method to predict protein size, based on protein database coordinates in silico. We tested the validity of these predictions using travelling wave ion mobility spectrometry – mass spectrometry, where predictions and measured values were within approximately 6%. We used the predictions, coupled with mass spectrometry, analytical ultracentrifugation and protein electrophoresis, to resolve previous conflicts and define the exclusion characteristics of the cyst nematode feeding tube. Heterogeneity was tested in the liquid, solid and gas phase to provide a comprehensive evaluation of three proteins of particular interest to feeding tube size exclusion, GFP, mRFP and Dual PI. The data and procedures described here could be applied to the design of plant expressed defence compounds intended for uptake into cyst nematodes. We also highlight the need to assess protein heterogeneity when creating novel fusion proteins. PMID:24489891

  1. Immediate Tube Feeding after Percutaneous Endoscopic Gastrostomy: Early Return to Goal Tube Feeds without Added Complications.

    PubMed

    Lamb, Laura C; Jayaraman, Vijay; Montgomery, Stephanie C; Umer, Affan; Shapiro, David S; Feeney, James M

    2017-02-01

    Percutaneous endoscopic gastrostomy (PEG) is frequently performed for delivery of nonoral enteral nutrition (EN) in critically ill patients. Tube-based supplement initiation is often delayed for a variety of reasons despite evidence that EN interruption results in worse outcomes. To determine if early initiation of EN after PEG placement is safe and well-tolerated in critically ill patients and if early initiation of EN results in more goal-accomplished days of EN. A retrospective chart review of patients who underwent PEG and at least 24 hours of EN. Patients were stratified according to time to tube- feed initiation: immediate (< one hour), early (one to four hours), and late (four to 24 hours). 'Ihe three groups were similar with respect to demographics, comorbidities, and 30-day mortality. Sixty-one percent of patients in the immediate group were advanced to the previously-met goal EN rates compared to 24% and 18% in the early and delayed groups, respectively (P < .0001). Immediate reinitiation of nonoral EN after PEG procedure is safe and is associated with reaching goal nutrition faster.

  2. Transition from tube feeding to oral feeding: experience in a tertiary care paediatric cardiology unit.

    PubMed

    Shine, Anne Marie; Finn, Daragh Gerard; Allen, Noeleen; McMahon, Colin J

    2018-05-02

    Home enteral tube feeding (HETF) is imperative for many infants and children with congenital heart disease (CHD). Tube weaning (TW) facilitates the progression from tube feeding to oral diet. There is limited literature on TW practices, protocols and success for children with CHD that have been tube fed. The objective of this study is to assess the process of weaning HETF in a tertiary referral centre for paediatric CHD. Specifically, we aimed to assess the duration of HETF, duration of TW and the interventions involved. We retrospectively reviewed the medical and dietetic records of all infants and children that were successfully weaned off HETF over a 12-month period from January 2015 to December 2015. There were 30 children included in the study, 9 boys and 21 girls. The diagnoses included 15 septal defects, 8 univentricular diagnosis and other diagnoses in 7 children. The median age at initiation of enteral tube feeding was 45 days (range 2-169). The median duration to wean from enteral tube feeding was 52 days (range 2-359). Number of dietetic consults required for successful TW varied among patients, median 5 (range 2-23). The number of days required for successful TW was associated with age and duration on HETF. Dietetic interventions included discontinuation of nutrient dense feeds, altering feed schedule and reduction of feed volume. Weaning HETF is possible in the outpatient setting. Early and frequent dietetic intervention is recommended to ensure prompt discontinuation of HETF when appropriate.

  3. In Vitro Evaluation of Eslicarbazepine Delivery via Enteral Feeding Tubes.

    PubMed

    Reindel, Kristin; Zhao, Fang; Hughes, Susan; Dave, Vivek S

    2017-12-01

    Purpose: The feasibility of preparing an eslicarbazepine acetate suspension using Aptiom tablets for administration via enteral feeding tubes was evaluated. Methods: Eslicarbazepine acetate suspension (40 mg/mL) was prepared using Aptiom tablets after optimizing the tablet crushing methods and the vehicle composition. A stability-indicating high-performance liquid chromatography (HPLC) method was developed to monitor the eslicarbazepine stability in the prepared suspension. Three enteric feeding tubes of various composition and dimensions were evaluated for the delivery of the suspensions. The suspension was evaluated for the physical and chemical stability for 48 hours. Results: The reproducibility and consistency of particle size reduction was found to be best with standard mortar/pestle. The viscosity analysis and physical stability studies showed that ORA-Plus:water (50:50 v/v) was optimal for suspending ability and flowability of suspension through the tubes. The developed HPLC method was found to be stability indicating and suitable for the assay of eslicarbazepine acetate in the prepared suspension. The eslicarbazepine concentrations in separately prepared suspensions were within acceptable range (±3%), indicating accuracy and reproducibility of the procedure. The eslicarbazepine concentrations in suspensions before and after delivery through the enteric feeding tubes were within acceptable range (±4%), indicating absence of any physical/chemical interactions of eslicarbazepine with the tubes and a successful delivery of eslicarbazepine dosage via enteric feeding tubes. The stability study results showed that eslicarbazepine concentration in the suspension remained unchanged when stored at room temperature for 48 hours. Conclusion: The study presents a convenient procedure for the preparation of a stable suspension of eslicarbazepine acetate (40 mg/mL) using Aptiom tablets, for administration via enteral feeding tubes.

  4. Utility of feeding jejunostomy tubes in pancreaticoduodenectomy.

    PubMed

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

    2017-03-01

    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.

  5. Transition from Tube to Oral Feeding in the School Setting

    ERIC Educational Resources Information Center

    McKirdy, Laura S.; Sheppard, Justine J.; Osborne, Mary L.; Payne, Pamela

    2008-01-01

    Purpose: A school-based treatment program for tube-fed children with medically complex conditions and food refusal was implemented to facilitate the children's transition to oral feeding and advance their eating skills. Method: The program combined educational and therapeutic goals. It was implemented in a regional public school for children with…

  6. Decreasing Use of Percutaneous Endoscopic Gastrostomy Tube Feeding in Japan.

    PubMed

    Komiya, Kosaku; Usagawa, Yuko; Kadota, Jun-Ichi; Ikegami, Naoki

    2018-05-25

    To identify trends in percutaneous endoscopic gastrostomy (PEG) tube placement and intravenous hyperalimentation (IVH) in nonhospital settings (as a potential alternative to tube feeding for nutrition) and to summarize published reports concerning the decision-making process for PEG placement. National survey and systematic review. Japan. All Japanese people. Data on numbers of individuals with a PEG tube and IVH were obtained from the website of the Japanese Ministry of Health, Labour, and Welfare and published reports concerning the decision-making process for PEG placement in Japan were summarized. The number of PEG tube placements peaked in 2007 and has been decreasing since Japan experienced the Great East Japan Earthquake in 2011. A further decline was seen in 2015 after the Japanese Ministry of Health, Labour and Welfare revised the fee schedule in 2014. More than half of individuals who had tubes were aged 80 and older during the years observed. In contrast, the number of individuals receiving IVH was lowest in the same year as PEG tube placement peaked and has been increasing ever since. Four studies reported that the decision-making process included consideration of not only the underlying disease, but also the individual's age and social barriers and the physician's personal philosophy. The number of PEG tube placements has been decreasing since its peak in 2007, and the number of individuals receiving IVH has been increasing. Many factors influence the decision-making process for PEG tube placement. Physicians in Japan may be realizing that there is little evidence to support the use of tube feeding in frail elderly adults. © 2018, Copyright the Authors Journal compilation © 2018, The American Geriatrics Society.

  7. Refining low protein modular feeds for children on low protein tube feeds with organic acidaemias.

    PubMed

    Daly, A; Evans, S; Ashmore, C; Chahal, S; Santra, S; MacDonald, A

    2017-12-01

    Children with inherited metabolic disorders (IMD) who are dependent on tube feeding and require a protein restriction are commonly fed by 'modular tube feeds' consisting of several ingredients. A longitudinal, prospective two-phase study, conducted over 18 months assessed the long-term efficacy of a pre-measured protein-free composite feed. This was specifically designed to meet the non-protein nutritional requirements of children (aged over 1 year) with organic acidaemias on low protein enteral feeds and to be used as a supplement with an enteral feeding protein source. All non-protein individual feed ingredients were replaced with one protein-free composite feed supplying fat, carbohydrate, and micronutrients. Thirteen subjects, median age 7.4y (3-15.5y), all nutritionally tube dependent (supplying nutritional intake: ≥ 90%, n = 12; 75%, n = 1), and diagnosed with organic acidaemias (Propionic acidaemia, n = 6; Vitamin B 12 non-responsive methyl malonic acidaemia, n = 4; Isovaleric acidaemia, n = 2; Glutaric aciduria type1, n = 1); were studied. Nutritional intake, biochemistry and anthropometry were monitored at week - 8, 0, 12, 26 and 79. Energy intake remained unchanged, providing 76% of estimated energy requirements. Dietary intakes of vitamins, minerals and essential fatty acids significantly increased from week 0 to week 79, but sodium, potassium, magnesium, decosahexanoic acid and fibre did not meet suggested requirements. Plasma zinc, selenium, haemoglobin and MCV significantly improved, and growth remained satisfactory. Natural protein intake met WHO/FAO/UNU 2007 recommendations. A protein-free composite feed formulated to meet the non-protein nutritional requirements of children aged over 1 year improved nutritional intake, biochemical nutritional status, and simplified enteral tube feeding regimens in children with organic acidaemias.

  8. Verifying placement of small-bore feeding tubes: electromagnetic device images versus abdominal radiographs.

    PubMed

    Bryant, Vera; Phang, Jean; Abrams, Kevin

    2015-11-01

    Clinicians are unsure if radiography is needed to confirm correct positioning of feeding tubes inserted with assistance from an electromagnetic system. To compare radiographic reports of feeding tube placement with images generated by an electromagnetic feeding tube placement device. The medical records of 200 consecutive patients who had feeding tubes inserted with assistance from an electromagnetic feeding tube placement device were reviewed retrospectively. Radiographic reports of tube site were compared with images generated by the device. Radiographic evidence of tube sites was available in 188 cases: 184 tubes were located in portions of the gastrointestinal tract. Ninety of the 188 tubes were situated in the optimal site (distal duodenum or jejunum) radiographically. Images generated by the electromagnetic device were available in 176 cases; of these, 52 tubes appeared to end in the expected left lower quadrant. Tubes shown on radiographs to be in other sites also occasionally appeared to end in the left lower quadrant. Nurses using the device did not recognize 4 of the 188 tubes (2.1%) that were inadvertently placed in the lung. No consistent pattern of quadrant distribution was found for tubes positioned in the stomach or proximal duodenum. Images generated by the electromagnetic tube placement device provided inconsistent results regarding tube location. A small percentage of seriously malpositioned tubes were not detected by using the electromagnetic device. These findings do not support eliminating radiographs to confirm correct tube placement following use of an electromagnetic tube placement device. ©2015 American Association of Critical-Care Nurses.

  9. Social Ecological Perspectives of Tube-Feeding Older Adults with Advanced Dementia: A Systematic Literature Review.

    PubMed

    Douglas, Joy W; Lawrence, Jeannine C; Turner, Lori W

    2017-01-01

    Dementia is a progressive, debilitating disease that often results in weight loss, malnutrition, and dehydration. Feeding tubes are often prescribed; however, this practice can lead to complications. The purpose of this systematic review was to examine the use of feeding tubes in elderly demented patients from a social ecological perspective. Results indicated that family members often receive inadequate decision-making education. Many health care professionals lack knowledge of evidence-based guidelines pertaining to feeding tube use. Organizational and financial reimbursement structures influence feeding tube use. Feeding practices for patients with advanced dementia is a complex issue, warranting approaches that target each level of the Social Ecological Model.

  10. Transpyloric Feeding Tube Placement Using Electromagnetic Placement Device in Children.

    PubMed

    Goggans, Margaret; Pickard, Sharon; West, Alina Nico; Shah, Samir; Kimura, Dai

    2017-04-01

    Transpyloric feeding tubes (TPT) are often recommended in critically ill children. Blind tube placement, however, can be difficult, be time-consuming, and incur multiple radiation exposures. An electromagnetic device (EMD) is available for confirmation of successful placement of TPTs. We conducted a retrospective cohort study to evaluate the efficacy of an EMD for TPT placement in children and determine its impact on placement success, radiation exposure, confirmation time, and cost for tube placement compared with traditional blind TPT placement. Retrospective data were collected in patients receiving a TPT before (pre-EMD group) and after implementation of an EMD (EMD group). Need for radiographic exposure decreased significantly in the EMD group (n = 40) compared with the pre-EMD group (n = 38) (0.6 vs 1.6 x-rays, P < .001). TPTs were placed and confirmed without abdominal x-ray in 21 of 40 patients in the EMD group. There were no serious adverse events such as misplacement into the lung or pneumothorax or perforation injury of the stomach. Successful tube confirmation took a significantly shorter time in the EMD group than in the pre-EMD group (1.45 vs 4.59 hours, P < .0001). There was an estimated cost savings of $245.10 per placement associated with decreased x-ray and fluoroscopy. The use of an EMD in children significantly decreased radiation exposure and confirmation time while maintaining TPT placement success. The use of an EMD can potentially offer large cost savings. Elimination of abdominal x-ray with EMD during TPT placement was achieved without any serious complications in approximately half of the children.

  11. Air feed tube support system for a solid oxide fuel cell generator

    DOEpatents

    Doshi, Vinod B.; Ruka, Roswell J.; Hager, Charles A.

    2002-01-01

    A solid oxide fuel cell generator (12), containing tubular fuel cells (36) with interior air electrodes (18), where a supporting member (82) containing a plurality of holes (26) supports oxidant feed tubes (51), which pass from an oxidant plenum (52") into the center of the fuel cells, through the holes (26) in the supporting member (82), where a compliant gasket (86) around the top of the oxidant feed tubes and on top (28) of the supporting member (82) helps support the oxidant feed tubes and center them within the fuel cells, and loosen the tolerance for centering the air feed tubes.

  12. Nasoenteral feeding tube placement by nurses using an electromagnetic guidance system (with video).

    PubMed

    Mathus-Vliegen, Elisabeth M H; Duflou, Ann; Spanier, Marcel B W; Fockens, Paul

    2010-04-01

    The early institution of feeding in patients who need postpyloric feeding tubes is often hampered by a limited availability of endoscopists experienced in safe tube positioning. To test the feasibility of having nurses place postpyloric feeding tubes by using a universal path finding system device. Prospective study. Academic hospital. The success rate and learning curve of a senior nurse placing postpyloric feeding tubes in 50 patients was studied, followed by a study in 160 patients on the success rates and learning curves of 4 inexperienced nurses instructed by the senior nurse. Finally, the success rate of postpyloric feeding tube placement by the senior nurse in 50 critically ill patients was investigated. Postpyloric feeding tube positioning by nurses using an electromagnetic universal path-finding system device enabling them to follow the path of the tip of the feeding tube on a monitor screen. Success was defined by postpyloric positioning of the feeding tube. The ultimate aim was to reach at least the duodenojejunal flexure. In the first part, the senior nurse was successful in 72% of cases. There was a clear learning curve. In the second part, the 4 newly instructed nurses had a success rate of 89.4% without an evident learning curve. In the third part, successful feeding tube positioning was achieved in 78% of critically ill patients. Of the 217 successfully positioned tubes, 74% reached at least the duodenojejunal flexure. In half of the unsuccessful cases, an explanation for the failure was found at endoscopy. No complications were seen. The generalization to less-specialized hospitals should be investigated. Postpyloric positioning of feeding tubes by nurses at the bedside without endoscopy is feasible and safe. Nurses may take over some of the tasks of doctors in a time of high endoscopic needs. Copyright 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  13. The Feasibility and Outcome of Oro-esophageal Tube Feeding in Patients with Various Etiologies.

    PubMed

    Kim, Juyong; Seo, Han Gil; Lee, Goo Joo; Han, Tai Ryoon; Oh, Byung-Mo

    2015-12-01

    The oro-esophageal tube (OE tube) is widely used in dysphagia patients although its success rate for transition to oral feeding is reported only in stroke patients. The aim of this study was to evaluate the feasibility and outcome of OE tube feeding for patients with dysphagia resulting from various etiologies. The authors reviewed the medical records of 1995 dysphagic patients that had undergone videofluoroscopic swallowing study (VFSS) in a tertiary hospital from April 2002 through December 2009. Of these, 97 patients were recommended to use OE tube feeding based on the VFSS findings. Follow-up VFSS were performed on 54 patients. The mean duration of tube use at the time of follow-up VFSS was 274 days. We evaluated clinical information including age, sex, diet, etiology of dysphagia, location of lesions, duration of intervention, and complications of OE tube feeding. Initially, all 54 patients were fed using the OE tube. After their last follow-up evaluation, 19 patients (35.2 %) resumed full oral feeding without the OE tube, 12 patients (22.2 %) used partial OE tube feeding, and 23 patients (42.6 %) continued OE tube feeding only. Full oral feeding was achieved again most often in brain tumor, stroke, and head and neck cancer patients (54.5, 27.3, and 20.0 %, respectively). Mild adverse events, such as blood-tinged sputum, nausea, dyspepsia, and regurgitation of food, were reported in 4 patients. OE tube feeding is a feasible feeding method also in conditions other than stroke such as brain tumors, and head and neck cancers.

  14. Survival times with and without tube feeding in patients with dementia or psychiatric diseases in Japan.

    PubMed

    Takayama, Keiko; Hirayama, Keisuke; Hirao, Akihiko; Kondo, Keiko; Hayashi, Hideki; Kadota, Koichi; Asaba, Hiroyuki; Ishizu, Hideki; Nakata, Kenji; Kurisu, Kairi; Oshima, Etsuko; Yokota, Osamu; Yamada, Norihito; Terada, Seishi

    2017-11-01

    It is widely supposed that there has been no evidence of increased survival in patients with advanced dementia receiving enteral tube feeding. However, more than a few studies have reported no harmful outcome from tube feeding in dementia patients compared to in patients without dementia. This was a retrospective study. Nine psychiatric hospitals in Okayama Prefecture participated in this survey. All inpatients fulfilling the entry criteria were evaluated. All subjects suffered from difficulty with oral intake. Attending physicians thought that the patients could not live without long-term artificial nutrition. The physicians decided whether to make use of long-term artificial nutrition between January 2012 and December 2014. We evaluated 185 patients. Their mean age was 76.6 ± 11.4 years. Of all subjects, patients with probable Alzheimer's disease (n = 78) formed the biggest group, schizophrenia patients (n = 44) the second, and those with vascular dementia (n = 30) the third. The median survival times were 711 days for patients with tube feeding and 61 days for patients without tube feeding. In a comparison different types of tube feeding, median survival times were 611 days for patients with a nasogastric tube and more than 1000 days for those with a percutaneous endoscopic gastrostomy tube. Patients with tube feeding survived longer than those without tube feeding, even among dementia patients. This study suggests that enteral nutrition for patients with dementia prolongs survival. Additionally, percutaneous endoscopic gastrostomy tube feeding may be safer than nasogastric tube feeding among patients in psychiatric hospitals. © 2017 Japanese Psychogeriatric Society.

  15. Variables associated with feeding tube placement in head and neck cancer.

    PubMed

    Cheng, Sara S; Terrell, Jeffrey E; Bradford, Carol R; Ronis, David L; Fowler, Karen E; Prince, Mark E; Teknos, Theodoros N; Wolf, Gregory T; Duffy, Sonia A

    2006-06-01

    To identify clinical factors associated with enteral feeding tube placement in a head and neck cancer population. A self-administered survey was given to patients being treated for head and neck cancer while they were waiting to be seen in 1 of 4 otolaryngology clinics. The post hoc analysis presented here combines survey and chart review data to determine clinical and demographic variables associated with feeding tube placement. Four otolaryngology clinics. Otolaryngology clinic patients being treated for head and neck cancer. Enteral feeding tube placement. Of the 724 patients eligible for this study, 14% (n = 98) required enteral feeding tube placement. Multivariate analysis found the following variables to be independently associated with feeding tube placement: oropharynx/hypopharynx tumor site (odds ratio [OR], 2.4; P = .01), tumor stage III/IV (OR, 2.1; P = .03), flap reconstruction (OR, 2.2; P = .004), current tracheotomy (OR, 8.0; P<.001), chemotherapy (OR, 2.6; P<.001), and increased age (OR, 1.3; P = .02). In addition, there was a curvilinear relationship between time since treatment and feeding tube placement, with about 30% having a feeding tube at 1 month posttreatment, tapering down during the first 3 years to about 8% and leveling off thereafter. Identification of factors associated with an increased risk of feeding tube placement may allow physicians to better counsel patients regarding the possibility of feeding tube placement during treatment. Since feeding tube placement has been linked to decreased quality of life in head and neck cancer, such counseling is an integral part of the clinical management of these patients.

  16. Colorimetric carbon dioxide detector to determine accidental tracheal feeding tube placement.

    PubMed

    Howes, Daniel W; Shelley, Eric S; Pickett, William

    2005-04-01

    To determine the accuracy of colorimetric CO2 detection compared to the reference standard two-step radiological confirmation of feeding tube position. A prospective study was conducted with patients presenting to a 21-bed medical-surgical intensive care unit. An adapter was developed using an endotracheal tube adapter to connect a colorimetric CO2 detector to a feeding tube in an airtight manner. In part I of the study a feeding tube connected to the colorimeter was inserted into the endotracheal tubes of ten ventilated patients to test the device's ability to detect tracheal placement. In part II patients undergoing feeding tube insertion had tube position confirmed with the colorimeter as well as the reference standard two-step x-ray. In phase I the colorimeter correctly identified tracheal placement in all ten patients. In phase II 93/100 procedures ultimately were eligible; the colorimeter had a sensitivity of 0.88 (95% confidence interval: 0.65-1.00) and specificity of 0.99 (0.97-1.00). The device missed one of the eight tracheal placements. Agreement between the colorimeter and two-step x-ray interpretations was excellent (Kappa 0.86; standard error 0.10). We describe a novel, convenient method to confirm esophageal feeding tube placement. The device is easily assembled and inexpensive, but should not be reused. Colorimetric determination of tracheal feeding tube placement with this device has excellent agreement with the reference standard two-step radiological technique.

  17. Efficacy of a Creon delayed-release pancreatic enzyme protocol for clearing occluded enteral feeding tubes.

    PubMed

    Stumpf, Janice L; Kurian, Rebecca M; Vuong, Jennifer; Dang, Kimberlyn; Kraft, Michael D

    2014-04-01

    Alkalinized Viokase pancreatic enzyme tablets restored patency to 71.9% of occluded Dobhoff tubes in a prospective study. After removal of Viokase tablets from the US market, the hospital protocol for unclogging enteral feeding tubes was adapted to use Creon pancreatic enzyme delayed-release capsules, despite the lack of published data. To evaluate the effectiveness of a Creon-based protocol to clear occluded enteral feeding tubes. This retrospective study included all adult and pediatric patients seen in the emergency department or in an inpatient setting who received Creon 12 000 units lipase delayed-release capsule dissolved in a solution of sodium bicarbonate 650 mg and sterile water for clearing occluded enteral feeding tubes between May 1 and November 30, 2010. The Creon protocol was deemed effective if tube clearance was documented in the medical record or if enteral feedings were resumed with no note regarding tube replacement. Alkalinized Creon delayed-release capsules were administered to 83 patients with a total of 118 clogged tubes. Three poorly documented cases and 5 tubes with mechanical clogs were excluded from data analysis. Patency was restored to 53 of 110 (48.2%) occluded tubes. More than 1 treatment course was attempted in 5 cases, with success in 3. An alkalinized Creon pancreatic enzyme protocol was effective in clearing approximately half of the occluded enteral feeding tubes in this retrospective study, an efficacy rate much less than that previously reported in the literature with a Viokase-based protocol.

  18. Predictors of Enteral Tube Feeding in Hospitalized Older Adults.

    PubMed

    Crenitte, Milton Roberto Furst; Avelino-Silva, Thiago Junqueira; Apolinario, Daniel; Curiati, Jose Antonio Esper; Campora, Flavia; Jacob-Filho, Wilson

    2017-11-01

    Despite general recognition that enteral tube feeding (ETF) is frequently employed in long-term care facilities and patients with dementia, remarkably little research has determined which factors are associated with its use in acutely ill older adults. In this study, we aimed to investigate determinants of ETF introduction in hospitalized older adults. We examined a retrospective cohort of acutely ill patients, aged 60 years and older, admitted to a university hospital's geriatric ward from 2014-2015, in São Paulo, Brazil. The main outcome was the introduction of ETF during hospitalization. Predictors of interest included age, sex, referring unit, comorbidity burden, functional status, malnutrition, depression, dementia severity, and delirium. Multivariate analysis was performed using backward stepwise logistic regression. A total of 214 cases were included. Mean age was 81 years, and 63% were women. Malnutrition was detected in 47% of the cases, dementia in 46%, and delirium in 36%. ETF was initiated in 44 (21%) admissions. Independent predictors of ETF were delirium (odds ratio [OR], 4.83; 95% CI, 2.12-11.01; P < .001) and total functional dependency (OR, 8.95; 95% CI, 2.87-27.88; P < .001). Malnutrition was not independently associated with ETF. One in five acutely ill older adults used ETF while hospitalized. Delirium and functional dependency were independent predictors of its introduction. Risks and benefits of enteral nutrition in this particular context need to be further explored.

  19. Proactive enteral tube feeding in pediatric patients undergoing chemotherapy.

    PubMed

    Sacks, Nancy; Hwang, Wei-Ting; Lange, Beverly J; Tan, Kay-See; Sandler, Eric S; Rogers, Paul C; Womer, Richard B; Pietsch, John B; Rheingold, Susan R

    2014-02-01

    To determine feasibility and safety of proactive enteral tube feeding (ETF) in pediatric oncology patients. Pediatric patients with newly diagnosed brain tumors, myeloid leukemia or high-risk solid tumors were eligible. Subjects agreeing to start ETF before cycle 2 chemotherapy were considered proactive participants (PPs). Those who declined could enroll as chart collection receiving nutritional standard of care. Nutritional status was assessed using standard anthropometric measurements. Episodes of infection and toxicity related to ETF were documented from diagnosis to end of therapy. A descriptive comparison between PPs and controls was conducted. One hundred four eligible patients were identified; 69 enrolled (20 PPs and 49 controls). At diagnosis, 17% of all subjects were underweight and 26% overweight. Barriers to enrollment included physician, subject and/or family refusal, and inability to initiate ETF prior to cycle 2 of chemotherapy. Toxicity of ETF was minimal, but higher percentage of subjects in the proactive group had episodes of infection than controls. Thirty-nine percent of controls eventually started ETF and were twice as likely to receive parenteral nutrition. PPs experienced less weight loss at ETF initiation than controls receiving ETF and were the only group to demonstrate improved nutritional status at end of study. Proactive ETF is feasible in children with cancer and results in improved nutritional status at end of therapy. Episodes of infection in this study are concerning; therefore, a larger randomized trial is required to further delineate infectious risks and toxicities that may be mitigated by improved nutritional status. © 2013 Wiley Periodicals, Inc.

  20. Do financial incentives of introducing case mix reimbursement increase feeding tube use in nursing home residents?

    PubMed

    Teno, Joan M; Feng, Zhanlian; Mitchell, Susan L; Kuo, Sylvia; Intrator, Orna; Mor, Vincent

    2008-05-01

    To determine whether adoption of Medicaid case mix reimbursement is associated with greater prevalence of feeding tube use in nursing home (NH) residents. Secondary analysis of longitudinal administrative data about the prevalence of feeding tube insertion and surveys of states' adoption of case mix reimbursement. NHs in the United States. NH residents at the time of NH inspection between 1993 and 2004. Facility prevalence of feeding tubes reported at the state inspection of NHs reported in the Online Survey, Certification and Reporting database and interviews with state policy makers regarding the adoption of case mix reimbursement. Between 1993 and 2004, 16 states adopted Resource Utilization Group case mix reimbursement. States varied in the prevalence of feeding tubes in their NHs. Although the use of feeding tube increased substantially over the years of the study, once temporal trends and facility fixed effects were accounted for, case mix reimbursement was not associated with greater prevalence of feeding tube use. The adoption of Medicaid case mix reimbursement was not associated with an increase in the prevalence of feeding tube use.

  1. Do Financial Incentives of Introducing Case Mix Reimbursement Increase Feeding Tube Use in Nursing Home Residents?

    PubMed Central

    Teno, Joan M.; Feng, Zhanlian; Mitchell, Susan L.; Kuo, Sylvia; Intrator, Orna; Mor, Vincent

    2013-01-01

    OBJECTIVES To determine whether adoption of Medicaid case mix reimbursement is associated with greater prevalence of feeding tube use in nursing home (NH) residents. DESIGN Secondary analysis of longitudinal administrative data about the prevalence of feeding tube insertion and surveys of states’ adoption of case mix reimbursement. SETTING NHs in the United States. PARTICIPANTS NH residents at the time of NH inspection between 1993 and 2004. MEASUREMENTS Facility prevalence of feeding tubes reported at the state inspection of NHs reported in the Online Survey, Certification and Reporting database and interviews with state policy makers regarding the adoption of case mix reimbursement. RESULTS Between 1993 and 2004, 16 states adopted Resource Utilization Group case mix reimbursement. States varied in the prevalence of feeding tubes in their NHs. Although the use of feeding tube increased substantially over the years of the study, once temporal trends and facility fixed effects were accounted for, case mix reimbursement was not associated with greater prevalence of feeding tube use. CONCLUSION The adoption of Medicaid case mix reimbursement was not associated with an increase in the prevalence of feeding tube use. PMID:18331293

  2. Corneal Abrasions

    MedlinePlus

    ... the doctor looks at the eye under a light that is filtered cobalt blue. The fluorescein causes the abrasion to glow bright green under the light. The doctor also might do a standard ophthalmic ...

  3. Retortable Laminate/Polymeric Food Tubes for Specialized Feeding

    DTIC Science & Technology

    2012-06-01

    on commercial off-the-shelf materials and not military unique. A market survey of commercially available laminated tubes revealed that they are all...on commercial off-the-shelf materials and not military unique. A market survey of commercially available laminated tubes revealed that they are...available materials and not be uniquely military. We surveyed the market for laminated retortable tubes and were not able to find any application

  4. Feeding tubes and health costs postinsertion in nursing home residents with advanced dementia.

    PubMed

    Hwang, Deborah; Teno, Joan M; Gozalo, Pedro; Mitchell, Susan

    2014-06-01

    The best evidence suggests that feeding tubes are ineffective in persons with advanced dementia. Little is known about their health care costs. To estimate Medicare costs attributable to inpatient care among nursing home (NH) residents with advanced dementia during the year following the placement of a percutaneous endoscopic gastrostomy (PEG) tube during an index hospitalization. Medicare claims (1999-2009) and Minimum Data Set data (1999-2009) were used to estimate Medicare costs attributable to inpatient care among NH residents with advanced dementia during the year following the placement of a PEG tube and compared with those who did not get a PEG tube. The study used a 3:1 propensity-matched cohort design. Matched residents with (n=1924, 68.9% female, 28.8% African American, average age 83.1 years) and without (weighted n=1924, unique n=4337) PEG insertion showed comparable sociodemographic characteristics, similar rates of feeding tube risk factors, and similar mortality (51.9% 180 day mortality among those with a feeding tube vs. 49.8% among those without a feeding tube, P=0.11). One year hospital costs were $2224 higher in NH residents with a feeding tube ($10,191 vs. $7967, 95% CI of difference=$1514, $2933), with those with a feeding tube likely to spend more time in an intensive care unit (1.92 vs. 1.29 days, 95% CI of difference=0.34, 0.92 days). In an analysis controlling for selection bias, PEG tube insertion is associated with a small but significant increase in annual inpatient health care costs, as well as in hospital and intensive care unit days, postinsertion. Copyright © 2014 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

  5. Comparison of complication rates in dogs with nasoesophageal versus nasogastric feeding tubes.

    PubMed

    Yu, Melissa K; Freeman, Lisa M; Heinze, Cailin R; Parker, Valerie J; Linder, Deborah E

    2013-01-01

    To compare complication rates between nasoesophageal (NE) and nasogastric (NG) feeding tubes in dogs. Retrospective study. University referral veterinary hospital. A total of 46 dogs that were fed through a NE (n = 28) or NG (n = 18) tube between January 2007 and December 2011 and that also had either thoracic radiography or computed tomography performed so that location of the distal tip of the tube in either the esophagus or stomach could be confirmed. None. The medical record of each eligible case was reviewed and data recorded included signalment, underlying disease, body weight, body condition score, medications, duration of feeding, diet used, and complications observed (ie, vomiting, regurgitation, diarrhea, early tube removal, clogged tube, epistaxis, pulmonary aspiration, hyperglycemia, and refeeding syndrome). Dogs with NE tubes were significantly younger than dogs with NG tubes (P = 0.03) but there were no other significant differences in signalment, underlying disease, medications, duration of anorexia, percent of resting energy requirement achieved, or change in weight during tube feeding. There also was no significant difference between the NE and NG groups for any of the recorded complications. Significantly fewer dogs in the NE group died or were euthanized (3/28) compared to the NG group (7/18; P = 0.02) but outcome was not associated with age, underlying disease, or any of the recorded tube complications. This study did not identify a difference in complication rate between NE and NG feeding tubes in dogs. Additional studies are required to determine the optimal terminal location of feeding tubes in dogs. © Veterinary Emergency and Critical Care Society 2013.

  6. Percutaneous transesophageal gastro-tubing (PTEG) as an alternative long-term tube feeding procedure when gastrostomy is not feasible

    PubMed Central

    Toh Yoon, Ezekiel Wong; Nishihara, Kazuki

    2017-01-01

    Background: Percutaneous transesophageal gastro-tubing (PTEG) is a minimally invasive technique to access the gut via an esophagostomy. However, this procedure is not well known and the literature available is still fairly limited. This observational study was conducted to evaluate our experience using this method as an alternative long-term tube feeding procedure when gastrostomy is not suitable. Methods: A total of 15 patients (10 males and 5 females) who underwent PTEG at our institution from 2012 to 2016 were observed and analyzed in this study. Results: The average age was 80.1 (71–93) years. Underlying conditions that required PTEG were previous gastric resection in 11 patients, left diaphragm disorder in 2 patients, interposing transverse colon between the abdominal wall and anterior gastric wall in 1 patient, and severe gastrostomy site leakage in 1 patient. Tube placement was successful in all patients by approaching the left side of the neck, using a 15 Fr size tube. The mean postoperative length of stay was 22 (8–48) days. Postoperative adverse events included accidental tube dislodgement in three patients, tracheoesophageal fistula in one patient, inferior thyroid artery injury in one patient and thyroid gland mispuncture in one patient. There was no procedure-related mortality nor mortality at 30 days. Eight patients were discharged with some oral intake. Conclusions: PTEG is feasible in patients requiring long-term tube feeding for whom gastrostomy is unsuitable. It is an effective long-term tube feeding procedure and should be offered as a more comfortable alternative to nasogastric tubing. PMID:29204186

  7. Percutaneous transesophageal gastro-tubing (PTEG) as an alternative long-term tube feeding procedure when gastrostomy is not feasible.

    PubMed

    Toh Yoon, Ezekiel Wong; Nishihara, Kazuki

    2017-12-01

    Percutaneous transesophageal gastro-tubing (PTEG) is a minimally invasive technique to access the gut via an esophagostomy. However, this procedure is not well known and the literature available is still fairly limited. This observational study was conducted to evaluate our experience using this method as an alternative long-term tube feeding procedure when gastrostomy is not suitable. A total of 15 patients (10 males and 5 females) who underwent PTEG at our institution from 2012 to 2016 were observed and analyzed in this study. The average age was 80.1 (71-93) years. Underlying conditions that required PTEG were previous gastric resection in 11 patients, left diaphragm disorder in 2 patients, interposing transverse colon between the abdominal wall and anterior gastric wall in 1 patient, and severe gastrostomy site leakage in 1 patient. Tube placement was successful in all patients by approaching the left side of the neck, using a 15 Fr size tube. The mean postoperative length of stay was 22 (8-48) days. Postoperative adverse events included accidental tube dislodgement in three patients, tracheoesophageal fistula in one patient, inferior thyroid artery injury in one patient and thyroid gland mispuncture in one patient. There was no procedure-related mortality nor mortality at 30 days. Eight patients were discharged with some oral intake. PTEG is feasible in patients requiring long-term tube feeding for whom gastrostomy is unsuitable. It is an effective long-term tube feeding procedure and should be offered as a more comfortable alternative to nasogastric tubing.

  8. Early discharge with tube feeding at home for preterm infants is associated with longer duration of breast feeding.

    PubMed

    Meerlo-Habing, Z E; Kosters-Boes, E A; Klip, H; Brand, P L P

    2009-07-01

    Mothers of preterm infants are more likely to discontinue breast feeding early than mothers of term infants. We evaluated the effect of early discharge with tube feeding of preterm infants under close supervision by paediatric nurse specialists on the duration of breast feeding. Case-control study. Medium/high-care neonatal unit of a large district general hospital. Preterm infants (<37 weeks' gestational age). Early discharge with tube feeding under close supervision by paediatric nurse specialists or regular follow-up of preterm infants discharged with oral feeding. Duration of breast feeding assessed by telephone interview 6 months after birth. There were 50 preterm infants in the early discharge group and 78 in the control group. Mothers in the early discharge group continued to breast feed longer than mothers in the control group (log rank test, p = 0.028). Four months after discharge, 63% of preterm infants in the control group were fed formula compared to 36% in the early discharge group (95% CI for difference 9% to 43%, p = 0.04). The relative risk of breast feeding cessation 6 months after birth in the early discharge group compared to the control group was 0.63 (95% CI 0.41 to 0.96). After adjustment for smoking, gestational age and birth weight, this relative risk was 0.67 (95% CI 0.43 to 1.05). Close supervision and follow-up by paediatric nurse specialists of preterm infants discharged early with tube feeding appears to increase duration of breast feeding. A randomised controlled trial to confirm these findings is warranted.

  9. Pneumonia Frequencies with Different Enteral Tube Feeding Access Sites.

    ERIC Educational Resources Information Center

    Taylor, Henry M.

    2002-01-01

    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)

  10. Continuous versus bolus tube feeds: Does the modality affect glycemic variability, tube feeding volume, caloric intake, or insulin utilization?

    PubMed

    Evans, David C; Forbes, Rachel; Jones, Christian; Cotterman, Robert; Njoku, Chinedu; Thongrong, Cattleya; Tulman, David; Bergese, Sergio D; Thomas, Sheela; Papadimos, Thomas J; Stawicki, Stanislaw P

    2016-01-01

    Enteral nutrition (EN) is very important to optimizing outcomes in critical illness. Debate exists regarding the best strategy for enteral tube feeding (TF), with concerns that bolus TF (BTF) may increase glycemic variability (GV) but result in fewer nutritional interruptions than continuous TF (CTF). This study examines if there is a difference in GV, insulin usage, TF volume, and caloric delivery among intensive care patients receiving BTF versus CTF. We hypothesize that there are no significant differences between CTF and BTF when comparing the above parameters. Prospective, randomized pilot study of critically ill adult patients undergoing percutaneous endoscopic gastrostomy (PEG) placement for EN was performed between March 1, 2012 and May 15, 2014. Patients were randomized to BTF or CTF. Glucose values, insulin use, TF volume, and calories administered were recorded. Data were organized into 12-h epochs for statistical analyses and GV determination. In addition, time to ≥80% nutritional delivery goal, demographics, Acute Physiology and Chronic Health Evaluation II scores, and TF interruptions were examined. When performing BTF versus CTF assessments, continuous parameters were compared using Mann-Whitney U-test or repeated measures t-test, as appropriate. Categorical data were analyzed using Fisher's exact test. No significant demographic or physiologic differences between the CTF (n = 24) and BTF (n = 26) groups were seen. The immediate post-PEG 12-h epoch showed significantly lower GV and median TF volume for patients in the CTF group. All subsequent epochs (up to 18 days post-PEG) showed no differences in GV, insulin use, TF volume, or caloric intake. Insulin use for both groups increased when comparing the first 24 h post-PEG values to measurements from day 8. There were no differences in TF interruptions, time to ≥80% nutritional delivery goal, or hypoglycemic episodes. This study demonstrated no clinically relevant differences in GV, insulin use, TF

  11. Litmus tests for verification of feeding tube location in infants: evaluation of their clinical use.

    PubMed

    Nyqvist, Kerstin Hedberg; Sorell, Annette; Ewald, Uwe

    2005-04-01

    To examine the clinical use of litmus paper tests for the assessment of aspirates in infants. In connection with establishing a programme for home care of infants with requirement of tube feeding with parents as the infants' carers, the need for a research-based method for verification of feeding tube position was identified by nurses as a complement to other methods. In adult care the litmus paper test is commonly used when visual inspection is not sufficient for assessment of aspirates obtained from feeding tubes. Observational study. Nurses performed litmus tests for verification of feeding tube location in a convenience sample of 60 infants born at a gestational age (GA) of 24-42 weeks. Presence/absence and volumes of aspirates were recorded as well as positive/negative litmus test reactions. Analyses on the association between test results and the infants' GA and postmenstrual and postnatal age at the time of the tests were conducted. Data were obtained from 2970 tube feeds. Aspirates were present on 1840 occasions (62%). A higher proportion of infants with absence of aspirates were born at a GA below 32 weeks. A positive reaction occurred in 97% of the tests in volumes between 0.01 and 22 ml. Birth at a GA below 32 weeks and respiratory problems were associated with negative tests. The high ratio of positive litmus reactions at all maturational levels supports the bedside use of analysis of pH in gastric aspirates for verification of feeding tube location. Application of pH indicator paper is recommended as a complementary method for assessment of aspirates from feeding tubes.

  12. Reduced Feeding Tube Duration with IMRT for Head and Neck Cancer: A SEER-Medicare Analysis

    PubMed Central

    Beadle, Beth M.; Liao, Kai-Ping; Giordano, Sharon H.; Garden, Adam S.; Hutcheson, Katherine A.; Lai, Stephen Y.; Guadagnolo, B. Ashleigh

    2016-01-01

    Background Intensity-modulated radiation therapy (IMRT) is a technologically advanced and resource-intensive method of delivering radiation therapy (RT) used to minimize toxicity for patients with head and neck cancers (HNC). Dependence on feeding tubes is a significant marker of toxicity of RT. The goal of this analysis was to compare the placement and duration of feeding tube use for patients with HNC from 1999-2011. Methods The cohort, demographics, and cancer-related variables were determined using the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database and analyzed regarding treatment details using claims data. Results A total of 2993 patients were identified. With a median follow-up of 47 months, 54.4% of patients had a feeding tube placed. The median duration from feeding tube placement to removal was 277 days. On zero-inflated negative binomial regression, patients treated with IMRT and 3DRT (non-IMRT) had similar rates of feeding tube placement (odds ratio (OR) 1.10; p=.35); however, patients treated with 3DRT had the feeding tube in place 1.18 times longer than those treated with IMRT (p=.03). The difference was only seen amongst patients treated with definitive radiation; patients treated with surgery and adjuvant radiation had no statistically significant difference in placement or duration. Conclusions Patients with HNC treated with definitive IMRT had significantly shorter duration of feeding tubes in place than those treated with 3DRT. These data suggest that there may be significant quality of life benefits to IMRT with respect to long-term swallowing function for patients. PMID:27662641

  13. Consideration of alternative designs for a Percutaneous Endoscopic Gastrostomy feeding tube

    NASA Astrophysics Data System (ADS)

    Yerrabolu, Santosh Rohit

    The inability of some people to chew or swallow foods (but can digest foods) due to problems associated with various diseases and complications leads them to insufficient nutritional intake and loss of quality of life. These individuals are generally provided with nutritional support by means of injecting or infusing food directly into their stomachs or small intestines via feeding tubes. Gastrostomy feeding tubes (G-tubes) are used when such nutritional support is required for over 3-6 weeks. Percutaneous Endoscopic Gastrostomy (PEG) tubes are one of the most widely used G- Tubes and devices which are inserted via an incision through the abdominal wall either through a pull or push method. This investigation proposes conceptual alternative Percutaneous Endoscopy Gastrostomy (PEG) feeding tube designs with optimized materials selection to be used for their construction. The candidate materials were chosen from 18 commercial catheters, 2 reference grade polymers and a commercial polymer; using tissue-catheter-friction testing and surface chemistry characterization (Infrared spectroscopy and Critical Surface Tension approximation). The main objectives considered were to minimize slipping/dislodgement of gastrostomy tube/seal, to reduce peristomal leakage, and to attain size variability of PEG tubes while maintaining a low profile. Scanning Electron Microscope- Energy Dispersive X-ray Spectroscopy was employed to further determine the filler materials used in the samples. Nylon coated with fatty ester and filled with Barium sulphate was determined as the optimum material for the construction of the tube part of the feeding tubes to reduce slipping/dislodgment of gastrostomy tube/seal and to minimize peristomal leakage. Nylon coated with fatty ester and filled with Silica is the suggested as a candidate material for construction of the bumper/mushroom sections of the feeding tubes to avoid the Buried Bumper Syndrome. Fused Deposition Modeling, Selective Laser Sintering

  14. Peristaltic pumping in an elastic tube: feeding the hungry python

    NASA Astrophysics Data System (ADS)

    Takagi, Daisuke; Balmforth, Neil

    2010-11-01

    Biological ducts convey contents like food in the digestive system by peristaltic action, propagating waves of muscular contraction and relaxation. The motion is investigated theoretically by considering a radial force of sinusoidal or Gaussian form moving steadily down a fluid-filled axisymmetric tube. Effects of the prescribed force on the resultant fluid flow and elastic deformation of the tube wall are presented. The flow can induce a rigid object suspended in the fluid to propel in different ways, as demonstrated in numerous examples.

  15. Successful use of a bulk laxative to control the diarrhea of tube feeding.

    PubMed

    Frank, H A; Green, L C

    1979-01-01

    The greatly increased nutritional demands of the severely burned patient frequently require the use of tube feeding for enternal hyperalimentation. At a time when general patient morale is low and motivation needs to be maximally maintained, there is nothing so dispiriting as the distress of a painful perianal region and uncontrollable liquid stools. Attempts to control the diarrhea which frequently accompanies tube feeding by changing the formula or the method of administration or a wide variety of constipating drugs have all met with very limited success. Based on the clinical observation of a noted gastroenterologist (Bockus), we have administered a mucilagenous hydrophilic colloid bulk laxative (Metamucil) to patients on tube feeding formulae. The dosage and frequency are adjusted to individual patient needs, but average 7 g per liter of liquid formula. The results have been dramatic; namely, the virtual elimination of the diarrhea problem in our burn patients on enteral hyperalimentation by gastric tube feeding. Colonic transit time increases. The stools become formed but soft, cohesive but not adhesive. Perianal irritation does not occur. Neither does soilage of wound, dressings, or bed. No rebound constipation or obstructive symptoms have been encountered. We attribute this response to the same water binding mechanism that allows these colloids to prevent chronic constipation. Our patients may be given as much as 5,000 to 6,000 calories of tube feeding per day. Our patients are not distressed by diarrhea. Our nursing staff is relieved of the burden that entails.

  16. The impact of HPV status on weight loss and feeding tube use in oropharyngeal carcinoma.

    PubMed

    Vangelov, Belinda; Kotevski, Damian P; Williams, Janet R; Smee, Robert I

    2018-04-01

    It has been well established that patients with oropharyngeal carcinoma are at high nutritional risk, with significant weight loss and tube feeding common. Human papillomavirus (HPV)-associated disease has led to a change in the "typical" presentation and nutritional profile of this population. The aim of our study was to determine whether the need for a feeding tube, and weight loss during radiotherapy (RT) in patients with oropharyngeal carcinoma differed with HPV status. Patients who received curative RT ± chemotherapy from January 2011 to January 2016 were included (n = 100). We retrospectively evaluated feeding tube use and timing of insertion (prophylactic vs reactive), percentage weight loss during RT and the prevalence of critical weight loss (CWL) ≥5%. HPV-positive patients had significantly higher weight loss during RT compared to the rest of the cohort (8.4% vs 6.1%, 95%CI 0.8-3.9, p = 0.003). CWL was observed in 86% and in a higher proportion with HPV-positive disease (93%, p = 0.011). Conditional probability modelling analysis revealed, with 74% accuracy, concurrent chemoradiotherapy and HPV-positive status were predictors of CWL when comparing HPV-positive patients to HPV-negative (96%, p = 0.001 and 98%, p = 0.012 respectively). More HPV-positive patients required feeding tubes (n = 43, 63%, p = 0.05), most being reactive (n = 27, 63%). All patients with reactive tubes experienced CWL. The high incidence of CWL in patients with HPV-positive oropharyngeal carcinoma is of concern. Tube feeding continues to be a necessary nutritional intervention in this population and predicting who will require a tube is challenging. Larger, prospective cohort studies are required. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Jejunal feeding tubes can be efficiently and independently placed by intensive care unit teams.

    PubMed

    Welpe, Pascal; Frutiger, Adrian; Vanek, Patrik; Kleger, Gian-Reto

    2010-01-01

    Nutrition support is an important therapeutic measure in critically ill patients. Several studies have shown that the enteral route is preferable to the parenteral route. Insertion of a feeding tube beyond the ligament of Treitz combined with continuous gastric drainage will reduce regurgitation and probably also the rate of nosocomial pneumonia. This study was conducted to assess the safety, success rate, and time required to establish jejunal nutrition by the fluoroscopy-guided technique in intensive care unit (ICU) patients. This was a prospective observational study in the ICUs of a 300-bed and a 600-bed community hospital. Indications were large gastric residuals during attempted gastric feeding, severe acute pancreatitis, or recurrent aspiration. Feeding tubes were introduced by the ICU staff at bedside under fluoroscopic guidance (a senior ICU physician and a resident or a registered ICU nurse). The correct jejunal position was documented by the application of a radiopaque contrast medium through the tube. After confirmation of the correct position, jejunal tube feeding was immediately started. The insertion procedure in 38 patients lasted a median of 17 minutes. The median time from decision to place the tube until start of enteral feeding was 141 minutes. The success rate was 84.2%. No adverse events were observed. Fluoroscopic placement of a jejunal feeding tube at the bedside is fast, is safe, and has a high success rate when performed by well-trained ICU staff. Using this method makes the ICU team more self-sufficient when critically ill patients require enteral nutrition and no gastroenterologist is available.

  18. Safety and Efficacy of Electromagnetic-Guided Bedside Placement of Nasoenteral Feeding Tubes versus Standard Placement.

    PubMed

    Shadid, Husam; Keckeisen, Maureen; Zarrinpar, Ali

    2017-10-01

    Although enteral feeding in critically ill patients has been shown to be beneficial, reliable postpyloric placement of feeding tubes remains a challenge. The standard of care involves blind placement, frequently requiring multiple attempts, and radiographs. To evaluate the effect of electromagnetic-guided bedside placement in reducing time to establishment of feeding, lung placement, use of radiography, and cost, we initiated a prospective trial using electromagnetic-guided bedside placement and compared them to a retrospective cohort. Fifty-three consecutive placements of nasoenteral feeding tubes were made using electromagnetic-guidance on patients requiring enteral nutrition in a surgical intensive care unit at a tertiary care center. Sixty-three placement attempts in the preceding seven months served as controls. There were no significant differences between the two groups in terms of age, sex, weight, body mass index, hiatal or ventral hernias, or previous esophageal/gastric operations. The number of radiographs needed per patient, need for fluoroscopy, radiology charge per patient for the tube placement, and time from first attempt at placement to confirmation of postpyloric location were lower for the electromagnetic-guided group. Use of electromagnetic guidance allows reliable and cost-effective postpyloric enteral feeding tube placement compared with blind insertion.

  19. Enteral tube feeding alters the oral indigenous microbiota in elderly adults.

    PubMed

    Takeshita, Toru; Yasui, Masaki; Tomioka, Mikiko; Nakano, Yoshio; Shimazaki, Yoshihiro; Yamashita, Yoshihisa

    2011-10-01

    Enteral tube feeding is widely used to maintain nutrition for elderly adults with eating difficulties, but its long-term use alters the environment of the oral ecosystem. This study characterized the tongue microbiota of tube-fed elderly adults by analyzing the 16S rRNA gene. The terminal restriction fragment length polymorphism (T-RFLP) profiles of 44 tube-fed subjects were compared with those of 54 subjects fed orally (average age, 86.4 ± 6.9 years). Bar-coded pyrosequencing data were also obtained for a subset of the subjects from each group (15 tube-fed subjects and 16 subjects fed orally). The T-RFLP profiles demonstrated that the microbiota of the tube-fed subjects was distinct from that of the subjects fed orally (permutational multivariate analysis of variance [perMANOVA], P < 0.001). The pyrosequencing data revealed that 22 bacterial genera, including Corynebacterium, Peptostreptococcus, and Fusobacterium, were significantly more predominant in tube-fed subjects, whereas the dominant genera in the subjects fed orally, such as Streptococcus and Veillonella, were present in much lower proportions. Opportunistic pathogens rarely detected in the normal oral microbiota, such as Corynebacterium striatum and Streptococcus agalactiae, were often found in high proportions in tube-fed subjects. The oral indigenous microbiota is disrupted by the use of enteral feeding, allowing health-threatening bacteria to thrive.

  20. Enteral Tube Feeding Alters the Oral Indigenous Microbiota in Elderly Adults ▿ †

    PubMed Central

    Takeshita, Toru; Yasui, Masaki; Tomioka, Mikiko; Nakano, Yoshio; Shimazaki, Yoshihiro; Yamashita, Yoshihisa

    2011-01-01

    Enteral tube feeding is widely used to maintain nutrition for elderly adults with eating difficulties, but its long-term use alters the environment of the oral ecosystem. This study characterized the tongue microbiota of tube-fed elderly adults by analyzing the 16S rRNA gene. The terminal restriction fragment length polymorphism (T-RFLP) profiles of 44 tube-fed subjects were compared with those of 54 subjects fed orally (average age, 86.4 ± 6.9 years). Bar-coded pyrosequencing data were also obtained for a subset of the subjects from each group (15 tube-fed subjects and 16 subjects fed orally). The T-RFLP profiles demonstrated that the microbiota of the tube-fed subjects was distinct from that of the subjects fed orally (permutational multivariate analysis of variance [perMANOVA], P < 0.001). The pyrosequencing data revealed that 22 bacterial genera, including Corynebacterium, Peptostreptococcus, and Fusobacterium, were significantly more predominant in tube-fed subjects, whereas the dominant genera in the subjects fed orally, such as Streptococcus and Veillonella, were present in much lower proportions. Opportunistic pathogens rarely detected in the normal oral microbiota, such as Corynebacterium striatum and Streptococcus agalactiae, were often found in high proportions in tube-fed subjects. The oral indigenous microbiota is disrupted by the use of enteral feeding, allowing health-threatening bacteria to thrive. PMID:21821752

  1. Extemporaneous procedures for dissolving risedronate tablets for oral administration and for feeding tubes.

    PubMed

    Dansereau, Richard J; Crail, Debbie J

    2005-01-01

    Risedronate (Actonel, Procter & Gamble Pharmaceuticals) is commercially available only as film-coated tablets. Extemporaneous procedures for dissolving tablets for feeding tubes and for preparation of an oral liquid have not previously been evaluated. To evaluate procedures for dissolving risedronate sodium tablets for administration in liquid form and drug recovery following dissolution in cups and following passage through different types of feeding tubes. Tablets (5 and 35 mg) were individually dispersed in 2 oz of water. After 2 minutes, the solution was stirred for 30 seconds, dispensed, and rinsed with an additional 4 oz of water. The sample was filtered and analyzed by HPLC. Ten replicates were performed using the various cups. Gastrostomy and nasoenteric tubes were flushed with 1 oz of water. Individual tablets were dispersed in 2 oz of water; after 2 minutes, the solution was stirred for 30 seconds and poured through the tube and flushed with 1 oz of water. Samples were filtered and analyzed by HPLC. Ten replicates were performed for each type of feeding tube. For cups, the mean amount of drug recovered ranged from 95.7% to 100.5% of the label claim, with a relative standard deviation (RSD) range of 1.1-6.3%. For gastrostomy and nasoenteric tubes, the mean amount of drug recovered ranged from 98.3% to 101.9% of label claim, with an RSD range of 0.9-3.3%. A simple and accurate procedure was developed for dissolving risedronate tablets in water to prepare a liquid formulation for administration orally or through feeding tubes.

  2. Incidence of Tube Feeding in 7174 Newly Admitted Nursing Home Residents With and Without Dementia.

    PubMed

    Schulze, Jana; Mazzola, Rosa; Hoffmann, Falk

    2016-02-01

    Tube feeding is a common form of long-term nutritional support, especially for nursing home residents, of whom many have dementia. Estimating the incidence of feeding tube placement in nursing home residents with and without dementia. Using claims data, we studied a cohort of newly admitted nursing home residents aged 65 years and older between 2004 and 2009. Analyses were stratified by dementia. We estimated incidence rates and performed multivariate Cox regression analyses. The study cohort included 7174 nursing home residents. Over a mean follow-up of 1.3 years, 273 people received a feeding tube. The incidence per 1000 person-years was 28.4, with higher estimates for patients with dementia. When adjusting for age, sex, and level of care as a time-dependent covariate, influence of dementia decreased to a nonsignificant hazard ratio. It seems that not dementia itself but the overall clinical condition might be a predictor of tube feeding placement. © The Author(s) 2015.

  3. Use of Noninvasive Ventilation During Feeding Tube Placement.

    PubMed

    Banfi, Paolo; Volpato, Eleonora; Valota, Chiara; D'Ascenzo, Salvatore; Alunno, Chiara Bani; Lax, Agata; Nicolini, Antonello; Ticozzi, Nicola; Silani, Vincenzo; Bach, John R

    2017-11-01

    Parenteral nutrition is indicated in amyotrophic lateral sclerosis (ALS) when dysphagia, loss of appetite, and difficulty protecting the airways cause malnutrition, severe weight loss, dehydration, and increased risk of aspiration pneumonia. The aim of this review is to compare percutaneous endoscopic gastrostomy (PEG), radiologically inserted G-tube (RIG), and percutaneous radiologic gastrostomy (PRG) in patients with ALS, performed with or without noninvasive ventilation (NIV). We searched PubMed, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the EBSCO Online Research Database, and Scopus up to December 2015. A priori selection included all randomized controlled trials (RCTs), quasi-randomized trials, and prospective and retrospective studies. The primary outcome was 30-d survival. We found no RCTs or quasi-RCTs. Seven studies about the implementation of the PEG/RIG procedure during the use of NIV and 5 studies without NIV were included. In another study of 59 subjects undergoing open gastrostomy, all with vital capacity < 30% of normal, 18 of whom were dependent on continuous NIV at full ventilatory support settings, there were no respiratory complications. Thus, the use of NIV during the implementation of these procedures, especially when used at full ventilatory support settings of pressure preset 18-25 cm H 2 O, can support alveolar ventilation before, during, and after the procedures and prevent respiratory complications. The procedures investigated appear equivalent, but the methodological quality of the studies could be improved. Possible benefits with regard to nutrition parameters, quality of life, and psychological features need to be further investigated. Copyright © 2017 by Daedalus Enterprises.

  4. Push versus gravity for intermittent bolus gavage tube feeding of premature and low birth weight infants.

    PubMed

    Dawson, Jennifer A; Summan, Ravinder; Badawi, Nadia; Foster, Jann P

    2012-11-14

    Many small, sick and premature infants are unable to coordinate sucking, swallowing and breathing, and therefore, require gavage feeding. In gavage feeding, milk feeds are delivered through a tube passed via the nose or mouth into the stomach. Intermittent bolus milk feeds may be administered using a syringe to gently push milk into the infant's stomach (push feed). Alternatively, milk can be poured into a syringe attached to the tube and allowed to drip in by gravity (gravity feed). To determine whether the use of push compared with gravity gavage feeding results in a more rapid establishment of full gavage feeds without increasing adverse events in preterm or low birth weight, infants who require intermittent bolus gavage feeding. We searched the following electronic databases to locate randomised controlled or quasi-randomised trials: Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2012, Issue 5), MEDLINE (from 1966 to May 2012), EMBASE (from 1980 to May 2012), and CINAHL (from 1982 to May 2012). We used the standard search strategy of the Cochrane Neonatal Review Group. Randomised or quasi-randomised controlled trials comparing push versus gravity intermittent gavage tube feeding in premature or low birth weight, or both, infants. We assessed the methodology of trials regarding blinding of randomisation and outcome measurement. We evaluated treatment effect with a fixed-effect model using risk ratio (RR), relative risk reduction, risk difference (RD) and number needed to treat (NNT) for categorical data; and using mean, standard deviation and weighted mean difference (WMD) for continuous data. We analysed outcomes measured as count data, for example frequency of apnoea, bradycardia and episodes of pulse oximeter oxygen (SpO(2)) desaturation, by comparing rates of events and the rate ratio. We evaluated heterogeneity to help determine the suitability of pooling results. Only one small cross-over trial met the criteria for inclusion

  5. Tube feeding and quality of life in children with severe neurological impairment.

    PubMed

    Mahant, S; Friedman, J N; Connolly, B; Goia, C; Macarthur, C

    2009-09-01

    To assess the quality of life (QOL) of neurologically impaired children before and after gastrostomy (G) and gastrojejunostomy (GJ) tube insertion. This was a prospective longitudinal study of children with severe neurological impairment who underwent G or GJ tube insertion. At baseline, and at 6 and 12 months after tube insertion, parents rated (1) global QOL and health-related quality of life (HRQOL) using 10 cm visual analogue scales, with 10 representing maximal QOL and (2) HR-QOL using a questionnaire-based measure. Fifty patients, 45 and five of whom underwent G and GJ tube insertion, respectively, were enrolled with a median age of 591 days. Forty-two had a static neurological disorder, and eight had a progressive neurological disorder. The mean weight for age z score increased significantly over time: -2.8 at baseline and -1.8 at 12 months. The mean QOL and HR-QOL scores at baseline were 5.5 and 5.6 out of 10, respectively. There was no significant change in these scores at 6 and 12 months post-tube insertion. Children with a progressive versus a static neurological disorder had a significantly lower QOL over time. Ease of medication administration as well as feeding showed a significant improvement in scores from baseline to 12 months. Parents felt that the G and GJ tube had a positive impact on their child's health at 6 months (86%) and 12 months (84%). QOL as rated by parents did not increase following insertion of a G or GJ tube in neurologically impaired children. However, parents felt that the tube had a positive impact on their child's health, particularly with regards to feeding and administration of medications.

  6. Family Experiences With Feeding Tubes in Neurologic Impairment: A Systematic Review.

    PubMed

    Nelson, Katherine E; Lacombe-Duncan, Ashley; Cohen, Eyal; Nicholas, David B; Rosella, Laura C; Guttmann, Astrid; Mahant, Sanjay

    2015-07-01

    Gastrostomy tubes (G-tubes) are frequently used to provide enteral nutrition for children who have neurologic impairment. Understanding the impact of G-tubes from the family's perspective will inform decision-making and improve support from health care providers. This study explored the experiences of families after G-tube placement in children with neurologic impairment. We conducted a systematic review of English-language qualitative primary research studies describing family experiences after G-tube placement. Six electronic databases were searched from inception to June 2014. Two authors independently screened and identified relevant studies, evaluated quality of reporting by using the Consolidated Criteria for Reporting Qualitative Research tool, and extracted data. Overarching concepts were developed by using thematic analysis. From 2674 screened abstracts, 84 texts were reviewed, and 13 studies met the inclusion criteria. G-tubes affect the lives of children, parents, and the family unit in many ways, both positive and negative. Improvements and challenges were described for children's health and happiness, for parental caregiving and stress, and for logistics and bonding within the family. G-tube feeding also changed relationships within the family, between the family and the medical system, and between the family and the outside world. Furthermore, experiences varied, with different families framing similar concepts as positive and negative. G-tube placement has diverse effects on daily life for children with neurologic impairment and their families. Clinicians may use the themes identified in this study to guide conversations with families about their values, experiences, and expectations before and after G-tube placement. Copyright © 2015 by the American Academy of Pediatrics.

  7. Evaluation of the benefits of gastric tube feeding in an elderly population.

    PubMed

    Weaver, J P; Odell, P; Nelson, C

    1993-09-01

    To assess the benefits of gastric tube feeding in an elderly community hospital population. One hundred consecutive patients who required feeding gastrostomies from July 1984 through June 1987. Durham (NC) Regional Hospital, a 380-bed community hospital. Patients were evaluated using a quality of life scale (QL scale) adapted from Spitzer's QL Index. The evaluation was based on hospital records at the time of tube placement and interviews with patients or family members at follow-up between June 1991 and March 1992. Subjective evaluation of the benefits of gastric tube feeding were obtained in interviews with patients or their families at follow-up. Overall there was no significant change in the objective evaluation of quality of life at follow-up. Men, patients over 76 years of age, and patients with chronic illnesses such as multiple strokes or dementia showed the poorest response on the QL scale. Subjective evaluation by patients or their family members was positively correlated with objective evaluation on the QL scale. Family members of patients who showed the poorest response on the QL scale were more likely than other family members to respond no to the question, "Would you want this done to you if you were in his/her situation?" Our QL scale provides a good indication of patients' and family members' subjective evaluation of the benefits of gastrostomy tube feeding after 4 to 8 years. Thus, the scale should be helpful to physicians who must consult with patients and their families and make decisions about the use of this procedure. The significant discrepancy between family members' evaluations of the benefit of the procedure to the patient and their refusal of the procedure for themselves if they were in the patient's situation confirms the need for advance directives and the importance of conscientious implementation of the Patient Self Determination Act of 1990.

  8. Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments

    SciTech Connect

    Mendler, O J; Takeuchi, K; Young, M Y

    1986-10-01

    The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results.

  9. Feeding the gut after revisional bariatric surgery: The fate of 126 enteral access tubes.

    PubMed

    Strong, Andrew T; Fayazzadeh, Hana; Sharma, Gautam; El-Hayek, Kevin; Kroh, Matthew; Rodriguez, John

    2018-03-09

    Revisional bariatric surgery (RBS) is associated with higher complication rates compared with primary bariatric surgery. Feeding tubes (FTs), including gastrostomy and jejunostomy tubes placed during RBS, may serve as a safety net to provide nutrition when oral intake is contraindicated or limited; however, FTs in this setting have not been well investigated. This study aims to determine complications, use, and duration of FTs placed during RBS. A high-volume academic medical center in the United States. Included patients underwent RBS between January 2008 and December 2016 with FTs placed at the time of RBS. There were 126 patients identified (84.9% female, 76.2% Caucasian, mean age 53.4-±10.9 yr). Patients had previously undergone Roux-en-Y gastric bypass (34.1%), vertical banded gastroplasty (27.8%), and adjustable gastric band (14.3%). Indications for RBS included correction of complication of prior bariatric surgeries (50%), weight regain/failure to lose weight (32.3%), or both (17.3%). Most FTs were placed in the excluded stomach (89.7%), and median tube size was 18 F. FTs were used for feeding in 68.2% of patients, with feeding initiated in a median of 2 days. Leakage around the tube (32.5%) and pain (26.8%) were common complaints. Significant tube-related complications included infection (9.1%), dislodgement (5.9%), reintervention (5.8%), and reoperation (2.8%); 16.7% experienced at least 1 significant complication. FTs were removed at a median of 36 days. FTs may aid in prevention of perioperative dehydration and malnutrition after RBS, but should not be considered a benign intervention. FT use should be balanced against institutional outcomes and care goals. Copyright © 2018 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  10. Shaping oral feeding in a gastronomy tube-dependent child in natural settings.

    PubMed

    Gutentag, S; Hammer, D

    2000-07-01

    A 3-year-old medically fragile girl who refused to eat after prolonged and frequent hospitalizations was started on a feeding program in the home and school settings. She exhibited food aversions and received all nourishment via a gastronomy tube. Preevaluation observations of her feeding behavior revealed that she refused all presented drinks and foods. Treatment was two-fold. First, food acceptance was followed by social praise and access to preferred toy play, and second, food refusal and disruptive behaviors were ignored. Gagging, vomiting, and crying occurred periodically during initial feedings. In addition, there were medical complications during the course of treatment necessitating continuous modifications of the program. Results of a multiple-phase design showed marked increases in the amount of food consumed at home, which then generalized to the school setting.

  11. Gastrostomy versus nasogastric tube feeding for chemoradiation patients with head and neck cancer: the TUBE pilot RCT.

    PubMed

    Paleri, Vinidh; Patterson, Joanne; Rousseau, Nikki; Moloney, Eoin; Craig, Dawn; Tzelis, Dimitrios; Wilkinson, Nina; Franks, Jeremy; Hynes, Ann Marie; Heaven, Ben; Hamilton, David; Guerrero-Urbano, Teresa; Donnelly, Rachael; Barclay, Stewart; Rapley, Tim; Stocken, Deborah

    2018-04-01

    Approximately 9000 new cases of head and neck squamous cell cancers (HNSCCs) are treated by the NHS each year. Chemoradiation therapy (CRT) is a commonly used treatment for advanced HNSCC. Approximately 90% of patients undergoing CRT require nutritional support via gastrostomy or nasogastric tube feeding. Long-term dysphagia following CRT is a primary concern for patients. The effect of enteral feeding routes on swallowing function is not well understood, and the two feeding methods have, to date (at the time of writing), not been compared. The aim of this pilot randomised controlled trial (RCT) was to compare these two options. This was a mixed-methods multicentre study to establish the feasibility of a RCT comparing oral feeding plus pre-treatment gastrostomy with oral feeding plus as-required nasogastric tube feeding in patients with HNSCC. Patients were recruited from four tertiary centres treating cancer and randomised to the two arms of the study (using a 1 : 1 ratio). The eligibility criteria were patients with advanced-staged HNSCC who were suitable for primary CRT with curative intent and who presented with no swallowing problems. The primary outcome was the willingness to be randomised. A qualitative process evaluation was conducted alongside an economic modelling exercise. The criteria for progression to a Phase III trial were based on a hypothesised recruitment rate of at least 50%, collection of outcome measures in at least 80% of those recruited and an economic value-of-information analysis for cost-effectiveness. Of the 75 patients approached about the trial, only 17 consented to be randomised [0.23, 95% confidence interval (CI) 0.13 to 0.32]. Among those who were randomised, the compliance rate was high (0.94, 95% CI 0.83 to 1.05). Retention rates were high at completion of treatment (0.94, 95% CI 0.83 to 1.05), at the 3-month follow-up (0.88, 95% CI 0.73 to 1.04) and at the 6-month follow-up (0.88, 95% CI 0.73 to 1.04). No serious adverse

  12. The molecular characterisation of Escherichia coli K1 isolated from neonatal nasogastric feeding tubes.

    PubMed

    Alkeskas, Aldukali; Ogrodzki, Pauline; Saad, Mohamed; Masood, Naqash; Rhoma, Nasreddin R; Moore, Karen; Farbos, Audrey; Paszkiewicz, Konrad; Forsythe, Stephen

    2015-10-26

    The most common cause of Gram-negative bacterial neonatal meningitis is E. coli K1. It has a mortality rate of 10-15 %, and neurological sequelae in 30-50 % of cases. Infections can be attributable to nosocomial sources, however the pre-colonisation of enteral feeding tubes has not been considered as a specific risk factor. Thirty E. coli strains, which had been isolated in an earlier study, from the residual lumen liquid and biofilms of neonatal nasogastric feeding tubes were genotyped using pulsed-field gel electrophoresis, and 7-loci multilocus sequence typing. Potential pathogenicity and biofilm associated traits were determined using specific PCR probes, genome analysis, and in vitro tissue culture assays. The E. coli strains clustered into five pulsotypes, which were genotyped as sequence types (ST) 95, 73, 127, 394 and 2076 (Achman scheme). The extra-intestinal pathogenic E. coli (ExPEC) phylogenetic group B2 ST95 serotype O1:K1:NM strains had been isolated over a 2 week period from 11 neonates who were on different feeding regimes. The E. coli K1 ST95 strains encoded for various virulence traits associated with neonatal meningitis and extracellular matrix formation. These strains attached and invaded intestinal, and both human and rat brain cell lines, and persisted for 48 h in U937 macrophages. E. coli STs 73, 394 and 2076 also persisted in macrophages and invaded Caco-2 and human brain cells, but only ST394 invaded rat brain cells. E. coli ST127 was notable as it did not invade any cell lines. Routes by which E. coli K1 can be disseminated within a neonatal intensive care unit are uncertain, however the colonisation of neonatal enteral feeding tubes may be one reservoir source which could constitute a serious health risk to neonates following ingestion.

  13. Pretreatment risk stratification of feeding tube use in patients treated with intensity-modulated radiotherapy for head and neck cancer.

    PubMed

    Anderson, Nigel J; Jackson, James E; Smith, Jennifer G; Wada, Morikatsu; Schneider, Michal; Poulsen, Michael; Rolfo, Maureen; Fahandej, Maziar; Gan, Hui; Joon, Daryl Lim; Khoo, Vincent

    2018-05-13

    The purpose of this study was to establish a risk stratification model for feeding tube use in patients who undergo intensity-modulated radiotherapy (IMRT) for head and neck cancers. One hundred thirty-nine patients treated with definitive IMRT (+/- concurrent chemotherapy) for head and neck mucosal cancers were included in this study. Patients were recommended a prophylactic feeding tube and followed up by a dietician for at least 8 weeks postradiotherapy (post-RT). Potential prognostic factors were analyzed for risk and duration of feeding tube use for at least 25% of dietary requirements. Many variables had significant effects on risk and/or duration of feeding tube use in univariate analyses. Subsequent multivariable analysis showed that T classification ≥3 and level 2 lymphadenopathy were the best independent significant predictors of higher risk and duration of feeding tube use, respectively, in oral cavity, pharyngeal, and supraglottic primaries. In patients treated with definitive IMRT, T classification ≥3 and level 2 lymphadenopathy can potentially stratify patients into 4 risk groups for developing severe dysphagia requiring feeding tube use. © 2018 Wiley Periodicals, Inc.

  14. Simple blood-feeding method for live imaging of gut tube remodeling in regenerating planarians.

    PubMed

    Hosoda, Kazutaka; Morimoto, Mizuki; Motoishi, Minako; Nishimura, Osamu; Agata, Kiyokazu; Umesono, Yoshihiko

    2016-04-01

    Live cell imaging is a powerful technique to study cellular dynamics in vivo during animal development and regeneration. However, few live imaging methods have been reported for studying planarian regeneration. Here, we developed a simple method for steady visualization of gut tube remodeling during regeneration of a living freshwater planarian, Dugesia japonica. When planarians were fed blood several times, gut branches were well-visualized in living intact animals under normal bright-field illumination. Interestingly, tail fragments derived from these colored planarians enabled successive observation of the processes of the formation of a single anterior gut branch in the prepharyngeal region from the preexisting two posterior gut branches in the same living animals during head regeneration. Furthermore, we combined this method and RNA interference (RNAi) and thereby showed that a D. japonica raf-related gene (DjrafA) and mek-related gene (DjmekA) we identified both play a major role in the activation of extracellular signal-regulated kinase (ERK) signaling during planarian regeneration, as indicated by their RNAi-induced defects on gut tube remodeling in a time-saving initial screening using blood-feeding without immunohistochemical detection of the gut. Thus, this blood-feeding method is useful for live imaging of gut tube remodeling, and provides an advance for the field of regeneration study in planarians. © 2016 Japanese Society of Developmental Biologists.

  15. Development and evaluation of an algorithm to facilitate drug prescription for inpatients with feeding tubes.

    PubMed

    Lohmann, Kristina; Freigofas, Julia; Leichsenring, Julian; Wallenwein, Chantal Marie; Haefeli, Walter Emil; Seidling, Hanna Marita

    2015-04-01

    We aimed to develop and evaluate an algorithm to facilitate drug switching between primary and tertiary care for patients with feeding tubes. An expert consortium developed an algorithm and applied it manually to 267 preadmission drugs of 46 patients admitted to a surgical ward of a tertiary care university hospital between June 12 and December 2, 2013, and requiring a feeding tube during their inpatient stay. The new algorithm considered the following principles: Drugs should be ideally listed on the hospital drug formulary (HDF). Additionally, drugs should include the same ingredient instead of a therapeutic equivalent. Preferred dosage forms were appropriate liquids, followed by solid drugs with liquid administration form, and solid drugs that could be crushed and/or suspended. Of all evaluated drugs, 83.5% could be switched to suitable drugs listed on the HDF and another 6.0% to drugs available on the German drug market. Additionally, for 4.1% of the drugs, the integration of individual switching rules allowed the switch from enteric-coated to immediate-release drugs. Consequently, 6.4% of the drugs could not be automatically switched and required case-to-case decision by a clinical professional (e.g., from sustained-release to immediate-release). The predefined principles were successfully integrated in the new algorithm. Thus, the algorithm switched more than 90% of the evaluated preadmission drugs to suitable drugs for inpatients with feeding tubes. This finding suggests that the algorithm can readily be transferred to an electronic format and integrated into a clinical decision support system.

  16. Attachment of and biofilm formation by Enterobacter sakazakii on stainless steel and enteral feeding tubes.

    PubMed

    Kim, Hoikyung; Ryu, Jee-Hoon; Beuchat, Larry R

    2006-09-01

    Enterobacter sakazakii has been reported to form biofilms, but environmental conditions affecting attachment to and biofilm formation on abiotic surfaces have not been described. We did a study to determine the effects of temperature and nutrient availability on attachment and biofilm formation by E. sakazakii on stainless steel and enteral feeding tubes. Five strains grown to stationary phase in tryptic soy broth (TSB), infant formula broth (IFB), or lettuce juice broth (LJB) at 12 and 25 degrees C were examined for the extent to which they attach to these materials. Higher populations attached at 25 degrees C than at 12 degrees C. Stainless steel coupons and enteral feeding tubes were immersed for 24 h at 4 degrees C in phosphate-buffered saline suspensions (7 log CFU/ml) to facilitate the attachment of 5.33 to 5.51 and 5.03 to 5.12 log CFU/cm(2), respectively, before they were immersed in TSB, IFB, or LJB, followed by incubation at 12 or 25 degrees C for up to 10 days. Biofilms were not produced at 12 degrees C. The number of cells of test strains increased by 1.42 to 1.67 log CFU/cm(2) and 1.16 to 1.31 log CFU/cm(2) in biofilms formed on stainless steel and feeding tubes, respectively, immersed in IFB at 25 degrees C; biofilms were not formed on TSB and LJB at 25 degrees C, indicating that nutrient availability plays a major role in processes leading to biofilm formation on the surfaces of these inert materials. These observations emphasize the importance of temperature control in reconstituted infant formula preparation and storage areas in preventing attachment and biofilm formation by E. sakazakii.

  17. Pre-radiotherapy feeding tube identifies a poor prognostic subset of postoperative p16 positive oropharyngeal carcinoma patients.

    PubMed

    Verma, Vivek; Liu, Jingxia; Eschen, Laura; Danieley, Jonathan; Spencer, Christopher; Lewis, James S; Diaz, Jason; Piccirillo, Jay F; Adkins, Douglas R; Nussenbaum, Brian; Thorstad, Wade L; Gay, Hiram A

    2015-01-09

    This study explores variables associated with poor prognosis in postoperative p16 positive oropharyngeal squamous cell carcinoma (OPSCC) patients undergoing adjuvant radiotherapy or chemoradiotherapy. Specifically, analysis was done related to timing of feeding tube insertion relative to radiotherapy. From 1997-2009, of 376 consecutive patients with OPSCC, 220 received adjuvant IMRT, and 97 were p16 positive and eligible. Of these, 23 had feeding tube placement before IMRT (B-FT), 32 during/after IMRT (DA-FT), and 42 had no feeding tube (NO-FT). Feeding tubes were not placed prophylactically. These three groups were analyzed for differential tumor, patient, treatment, and feeding tube characteristics, as well as differences in overall survival (OS), disease free survival (DFS), and distant metastasis free survival (DMFS). Pre-RT FT insertion was associated with higher tumor size and depth, T (but not N) and overall stage, comorbidities, presence of chemotherapy, and less use of transoral laser microsurgery/transoral bovie. Additionally, time from surgery to IMRT completion was also statistically longer in the B-FT group. The feeding tube was permanent in 52% of patients in the B-FT group versus 16% in the DA-FT group (p = 0.0075). The 5-year OS for the NO-FT, DA-FT, and B-FT groups was 90%, 86%, and 50%, respectively. The 5-year DFS for the NO-FT, DA-FT, and B-FT groups was 87.6%, 83.6%, and 42.7%, respectively. Multivariate analysis showed that for OS and DFS, feeding tube placement timing and smoking history were statistically significant. Due to the poor prognosis of early FT insertion, the presence of FTs at time of radiotherapy consultation can be used as an alternate marker to identify a subset of p16 positive OPSCC patients that have a poor prognosis.

  18. Effect of timing and method of enteral tube feeding for dysphagic stroke patients (FOOD): a multicentre randomised controlled trial.

    PubMed

    Dennis, M S; Lewis, S C; Warlow, C

    Undernutrition is common in patients admitted with stroke. We aimed to establish whether the timing and route of enteral tube feeding after stroke affected patients' outcomes at 6 months. The FOOD trials consist of three pragmatic multicentre randomised controlled trials, two of which included dysphagic stroke patients. In one trial, patients enrolled within 7 days of admission were randomly allocated to early enteral tube feeding or no tube feeding for more than 7 days (early versus avoid). In the other, patients were allocated percutaneous endoscopic gastrostomy (PEG) or nasogastric feeding. The primary outcome was death or poor outcome at 6 months. Analysis was by intention to treat. Between Nov 1, 1996, and July 31, 2003, 859 patients were enrolled by 83 hospitals in 15 countries into the early versus avoid trial. Early tube feeding was associated with an absolute reduction in risk of death of 5.8% (95% CI -0.8 to 12.5, p=0.09) and a reduction in death or poor outcome of 1.2% (-4.2 to 6.6, p=0.7). In the PEG versus nasogastric tube trial, 321 patients were enrolled by 47 hospitals in 11 countries. PEG feeding was associated with an absolute increase in risk of death of 1.0% (-10.0 to 11.9, p=0.9) and an increased risk of death or poor outcome of 7.8% (0.0 to 15.5, p=0.05). Early tube feeding might reduce case fatality, but at the expense of increasing the proportion surviving with poor outcome. Our data do not support a policy of early initiation of PEG feeding in dysphagic stroke patients.

  19. [Nasogastric tube feeding in bulimia. Controlled study with follow-up at 3 months].

    PubMed

    Rigaud, Daniel; Brayer, Véronique; Biton-Jélic, Violaine; Païs, Vanessa; Pennacchio, Hélène; Brun, Jean-Marcel

    2007-10-01

    Few effective treatments are available for severe forms of bulimia nervosa, which are accompanied by malnutrition, anxiety, and depressive mood. We previously showed in an open study that nasogastric tube feeding (TF) reduced binges and purging in patients with anorexia nervosa. This prospective randomized trial compared bulimia patients in two treatment groups: one group received TF at home, together with psychotherapy, nutritional counseling and a support group while the control group received only psychotherapy, nutritional counseling, and a support group. Patients in the first group underwent TF for 8 weeks (exclusively for 10 days and associated with meals thereafter). Assessment was based on clinical examination, laboratory results, and a variety of questionnaires (our in-house instrument for measuring binge and vomiting episodes, eating disorder inventory, Beck's depression inventory and the Hamilton rating scale for anxiety), all performed at the onset of treatment and at 8 days, 8 weeks (i.e., the end of TF), and 3 months after treatment began. Binges and vomiting disappeared faster and more frequently in TF patients than in the control group: 65% versus 29% (p<0.01). Three months later, these remained less frequent in the TF group than among controls (52% versus 33%, p=0.064). Nutritional status, depression, and anxiety improved more among the TF than control subjects (p<0.05). Tube feeding was effective in these patients with bulimia nervosa, reducing the number of binge and vomiting episodes and improving nutritional status and mood.

  20. Compounding rifampin suspensions with improved injectability for nasogastric enteral feeding tube administration.

    PubMed

    de Villiers, Melgardt M; Vogel, Laura; Bogenschutz, Monica C; Fingerhut, Bonnie J; D'Silva, Joseph B; Moore, Anne

    2010-01-01

    Often medications that have to be administered to patients via a nasogastric enteral feeding tubes are only available as tablets and capsules with no suitable commercial liquid alternatives. In such situations, pharmacists and nurses have to compound the tablets and capsule contents into liquid suspension formulations for dosing. The risk of occlusion of the enteral tubes during administration is reduced by employing liquid suspensions that are composed of small and uniform particles, not subject to rapid rates of settling, resistant to caking, and easily and uniformly re-suspended upon agitation. Present techniques often employ a manual process, such as a mortar and pestle, to accomplish the particle size reduction and subsequent incorporation into a suitable liquid diluent. A new compounding device has been invented that employs an automated wet-milling process in a single-use disposable plastic container to compound the suspensions. The two processes were compared using Rifampin capsules and various liquid diluents. A prototype version of the new device was employed in the experiments. The physical characteristics of the compounded suspensions were evaluated by determining sedimentation rate, sedimentation volume, and particle size and shape using laser light scattering, optical microscopy, and scanning electron microscopy techniques. The use characteristic of the compounded suspensions was evaluated using a nasogastric tube inject ability test. The results indicated that suspensions prepared using the new device were more resistant to sedimentation and caking and were easier to re-disperse into a uniform mixture by gentle shaking. The results were a consequence of the particles generated by the new device which were found to be smaller and more uniform in shape and size. The suspensions prepared using the new device did not cause blockage of the enteral feeding tubes in comparison to those prepared using a mortar and pastle. In conclusion, the results indicate

  1. The Fate of Fat: Pre-Exposure Fat Losses during Nasogastric Tube Feeding in Preterm Newborns

    PubMed Central

    Rayyan, Maissa; Rommel, Nathalie; Allegaert, Karel

    2015-01-01

    Deficient nutritional support and subsequent postnatal growth failure are major covariates of short- and long-term outcome in preterm neonates. Despite its relevance, extrauterine growth restriction (EUGR) is still prevalent, occurring in an important portion of extremely preterm infants. Lipids provide infants with most of their energy needs, but also cover specific supplies critical to growth, development and health. The use of human milk in preterm neonates results in practices, such as milk storage, pasteurization and administration by an infusion system. All of these pre-exposure manipulations significantly affect the final extent of lipid deposition in the intestinal track available for absorption, but the impact of tube feeding is the most significant. Strategies to shift earlier to oral feeding are available, while adaptations of the infusion systems (inversion, variable flow) have only more recently been shown to be effective in “in vitro”, but not yet in “in vivo” settings. Pre-exposure-related issues for drugs and nutritional compounds show similarities. Therefore, we suggest that the available practices for “in vitro” drug evaluations should also be considered in feeding strategies to further reduce pre-exposure losses as a strategy to improve the nutritional status and outcome of preterm neonates. PMID:26230707

  2. Extraction of the plasticizers diethylhexylphthalate and polyadipate from polyvinylchloride nasogastric tubes through gastric juice and feeding solution.

    PubMed

    Subotic, Ulrike; Hannmann, Torsten; Kiss, Matthias; Brade, Joachim; Breitkopf, Katja; Loff, Steffan

    2007-01-01

    Except for polyadipate, which is used as an alternative in polyvinylchloride (PVC) feeding tubes, diethylhexylphthalate (DEHP) is the plasticizer used almost exclusively in PVC medical products. A clear response to the chronic intake of DEHP has been shown in several organ systems from different species. In the present study, we compared the extraction of DEHP and polyadipate from PVC gastric tubes. An in vivo setting was simulated. We used 5 cm of PVC nasogastric tubes containing DEHP or polyadipate, which were incubated with gastric juice for 1 week and a feeding solution for 4 weeks. The leakage of these plasticizers was measured daily in the gastric juice group and weekly in the feeding solution group. The amount of plasticizer extracted was compared between groups and days. In the feeding solution group, the extraction of DEHP ranged from 200 to 542 microg after 1 week and from 660 to 1700 microg after 4 weeks. The extraction of polyadipate was 10 times lower than that of DEHP. In the gastric juice group, extracted DEHP ranged from 635 to 1043 microg, whereas the extraction of polyadipate was 100 times lower. Within 1 week, the extraction of DEHP from a 5-cm PVC tube reaches up to 1 mg. Extrapolated, this represents an in vivo load of up to 4 mg. The load accumulated by a newborn in an intensive care unit can therefore easily reach several milligrams of DEHP per day. Polyadipate nasogastric tubes may therefore be an alternative and help to reduce the daily load of DEHP.

  3. Strangulation by Feeding Tube in a 23-Month-Old With Down Syndrome: Case Report and Review of Literature.

    PubMed

    Woodham, Paige C; Fulcher, James W; Ward, Michael E

    2016-12-01

    Ligature strangulation, although typically homicidal in nature, has been reported as accidental in both the pediatric and adult populations. The unique mode of accidental strangulation with a gastric feeding tube in a 23-month-old with Down syndrome is currently unreported in the literature and has prompted us to report this case and look into safety modifications that can be made to these common medical devices. Given the number of children with gastric feeding tubes and concern over this exact scenario brought up by parents, it is unusual that a similar case has not been reported.

  4. Factors associated with nosocomial diarrhea in patients with enteral tube feeding.

    PubMed

    Trabal, J; Leyes, P; Hervás, S; Herrera, M; de Talló Forga, Ma

    2008-01-01

    Diarrhea is a frequent complication associated to enteral tube feeding (ETF) and it is a frequent cause of reduction or suspension of this type of nutritional support. Our objective was to evaluate the factors associated with nosocomial diarrhea in patients receiving ETF. The only significant factor associated with the appearance of diarrhea was antibiotic consumption, specially those patients receiving the combination of two or more antibiotics. We did not find any association between factors related to ETF, analytical parameters, nor other medications and diarrhea. Our observational data supports the idea that ETF should not be seen as a primary cause of diarrhea, other possible causes should be considered before reducing or discontinuing ETF administration.

  5. Enteral tube feeding in adults with cystic fibrosis; patient choice and impact on long term outcomes.

    PubMed

    White, H; Morton, A M; Conway, S P; Peckham, D G

    2013-12-01

    Enteral tube feeding (ETF) has been evaluated in paediatric and mixed child and adult populations with cystic fibrosis, demonstrating positive outcomes from 6 months to 2 years post insertion. No studies have examined the longer term nutritional and clinical outcomes in an exclusively adult population with cystic fibrosis or compared the outcomes for those who meet standard criteria and opt to undertake or decline ETF. Twenty three out of 380 patients attending the Leeds Regional Adult CF unit fulfilled the standard criteria for commencing ETF (CF Trust, 2002) between 2004 and 2008. Weight, BMI, FEV1, FVC, CFRD, and number of intravenous antibiotic treatment days were collected at 1 year pre baseline, at baseline, and at 1, 2, and 3 years post baseline for all these patients whether they accepted or declined ETF. Seventeen of the 23 patients agreed to accept a programme of ETF, two of whom died within the first year of ETF. In the remaining patients (n=15), weight increased by 19.5% from baseline (p<0.001), BMI increased to within the normal range and lung function stabilised. There was no reduction in the requirement for intravenous antibiotic treatment. The six patients who declined ETF had a decline in lung function and no weight gain. Supplemental enteral tube feeding improves clinical outcomes when administered over 3 years, resulting in significant weight gain, a normal BMI and stabilisation of lung function. It does not reduce intravenous antibiotic treatment days. In contrast those patients eligible for, but who declined ETF, showed a deterioration in lung function and a failure to gain weight and to achieve normal BMI status. Copyright © 2013 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  6. Electrical conduction along endothelial cell tubes from mouse feed arteries: confounding actions of glycyrrhetinic acid derivatives

    PubMed Central

    Behringer, Erik J; Socha, Matthew J; Polo-Parada, Luis; Segal, Steven S

    2012-01-01

    BACKGROUND AND PURPOSE Electrical conduction along endothelium of resistance vessels has not been determined independently of the influence of smooth muscle, surrounding tissue or blood. Two interrelated hypotheses were tested: (i) Intercellular conduction of electrical signals is manifest in endothelial cell (EC) tubes; and (ii) Inhibitors of gap junction channels (GJCs) have confounding actions on EC electrical and Ca2+ signalling. EXPERIMENTAL APPROACH Intact EC tubes were isolated from abdominal muscle feed (superior epigastric) arteries of C57BL/6 mice. Hyperpolarization was initiated with indirect (ACh) and direct (NS309) stimulation of intermediate- and small-conductance Ca2+-activated K+ channels (IKCa/SKCa). Remote membrane potential (Vm) responses to intracellular current injection defined the length constant (λ) for electrical conduction. Dye coupling was evaluated following intracellular microinjection of propidium iodide. Intracellular Ca2+ dynamics were determined using Fura-2 photometry. Carbenoxolone (CBX) or β-glycyrrhetinic acid (βGA) was used to investigate the role of GJCs. KEY RESULTS Steady-state Vm of ECs was −25 mV. ACh and NS309 hyperpolarized ECs by −40 and −60 mV respectively. Electrical conduction decayed monoexponentially with distance (λ∼1.4 mm). Propidium iodide injected into one EC spread into surrounding ECs. CBX or βGA inhibited dye transfer, electrical conduction and EC hyperpolarization reversibly. Both agents elevated resting Ca2+ while βGA inhibited responses to ACh. CONCLUSIONS AND IMPLICATIONS Individual cells were effectively coupled to each other within EC tubes. Inhibiting GJCs with glycyrrhetinic acid derivatives blocked hyperpolarization mediated by IKCa/SKCa channels, regardless of Ca2+ signalling, obviating use of these agents in distinguishing key determinants of electrical conduction along the endothelium. PMID:22168386

  7. Continuous versus bolus intragastric tube feeding for preterm and low birth weight infants with gastro-oesophageal reflux disease.

    PubMed

    Richards, Robyn; Foster, Jann P; Psaila, Kim

    2014-07-17

    Gastro-oesophageal reflux disease is a particularly common condition in preterm and low birth weight infants. These infants are also more likely to have excessive regurgitation, as they do not have a fully developed antireflux mechanism. Preterm and low birth weight infants who are unable to suck oral feeds are required to be fed via an intragastric tube for varying lengths of time. Intragastric tube feeding can be delivered by the intermittent bolus or continuous feeding method. Use of continuous or intermittent bolus intragastric feeding may have a positive or negative effect on the incidence or severity of gastro-oesophageal reflux disease. To determine whether continuous or intermittent bolus intragastric tube feeding reduces the number of episodes and the duration of gastro-oesophageal reflux disease (GORD) in preterm and low birth weight infants.We intended to perform subgroup analyses for gestational age; birth weight; age in days from birth at full enteral feeding via intragastric tube (breast vs bottle); frequency of intermittent bolus feed; and type of medication for treatment of GORD (only if medication prescribed and given similarly to both intervention groups). We used the standard search strategy of the Cochrane Neonatal Group as described in The Cochrane Library (www.thecochranelibrary.com) to search for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 9), MEDLINE (1966 to September 2013), EMBASE (1980 to September 2013) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to September 2013). We also searched previous reviews, including cross-references, abstracts and conference and symposia proceedings of the Perinatal Society of Australia and New Zealand and the Pediatric Academic Societies (American Pediatric Society/Society for Pediatric Research and European Society for Paediatric Research) from 1990 to 2012. Published and unpublished RCTs and quasi

  8. The Effects of Pre-Operative Enteral Nutrition from Nasal Feeding Tubes on Gastric Outlet Obstruction.

    PubMed

    Chen, Zhi-Hua; Lin, Su-Yong; Dai, Qi-Bao; Hua, Jin; Chen, Shao-Qin

    2017-04-10

    We examined gastric outlet obstruction (GOO) patients who received two weeks of strengthening pre-operative enteral nutrition therapy (pre-EN) through a nasal-jejenal feeding tube placed under a gastroscope to evaluate the feasibility and potential benefit of pre-EN compared to parenteral nutrition (PN). In this study, 68 patients confirmed to have GOO with upper-gastrointestinal contrast and who accepted the operation were randomized into an EN group and a PN group. The differences in nutritional status, immune function, post-operative complications, weight of patients, first bowel sound and first flatus time, pull tube time, length of hospital stay (LOH), and cost of hospitalization between pre-operation and post-operation were all recorded. Statistical analyses were performed using the chi square test and t -test; statistical significance was defined as p < 0.05. The success rate of the placement was 91.18% (three out of 31 cases). After pre-EN, the levels of weight, albumin (ALB), prealbumin (PA), and transferrin (TNF) in the EN group were significantly increased by pre-operation day compared to admission day, but were not significantly increased in the PN group; the weights in the EN group were significantly increased compared to the PN group by pre-operation day and day of discharge; total protein (TP), ALB, PA, and TNF of the EN group were significantly increased compared to the PN group on pre-operation and post-operative days one and three. The levels of CD3+, CD4+/CD8+, IgA, and IgM in the EN group were higher than those of the PN group at pre-operation and post-operation; the EN group had a significantly lower incidence of poor wound healing, peritoneal cavity infection, pneumonia, and a shorter first bowel sound time, first flatus time, and post-operation hospital stay than the PN group. Pre-EN through a nasal-jejunum feeding tube and placed under a gastroscope in GOO patients was safe, feasible, and beneficial to the nutrition status, immune function

  9. Quality of Life Issues for Families Who Make the Decision to Use a Feeding Tube for Their Child with Disabilities.

    ERIC Educational Resources Information Center

    Brotherson, Mary Jane; And Others

    1995-01-01

    Eight families deciding to use a feeding tube to meet the nutrition needs of their children with disabilities were interviewed over a two-year period. Family decision making in the context of quality of life was examined using a theoretical family systems model. Implications for future interventions are addressed. (Author/SW)

  10. Knowledge of Staff Members of Residential Care Facilities for Individuals with Intellectual Disability on Medication Administration via Enteral Feeding Tube

    ERIC Educational Resources Information Center

    Joos, E.; Mehuys, E.; Van Bocxlaer, J.; Remon, J. P.; Van Winckel, M.; Boussery, K.

    2016-01-01

    Background: Guidelines for the safe administration of drugs through enteral feeding tube (EFT) are an important tool to minimise the risk of errors. This study aimed to investigate knowledge of these guidelines among staff of residential care facilities (RCF) for people with ID. Method: Knowledge was assessed using a 13-item self-administered…

  11. Crashworthiness of Aluminium Tubes; Part 1: Hydroforming at Different Corner-Fill Radii and End Feeding Levels

    NASA Astrophysics Data System (ADS)

    D'Amours, Guillaume; Rahem, Ahmed; Williams, Bruce; Worswick, Michael; Mayer, Robert

    2007-05-01

    The automotive industry, with an increasing demand to reduce vehicle weight through the adoption of lightweight materials, requires a search of efficient methods that suit these materials. One attractive concept is to use hydroforming of aluminium tubes. By using FE simulations, the process can be optimized to reduce the risk for failure while maintaining energy absorption and component integrity under crash conditions. It is important to capture the level of residual ductility after forming to allow proper design for crashworthiness. This paper presents numerical and experimental studies that have been carried out for high pressure hydroforming operations to study the influence of the tube corner radius, end feeding, material thinning, and work hardening in 76.2 mm diameter, 3 mm wall thickness AA5754 aluminium alloy tube. End feeding was used to increase the formability of the tubes. The influence of the end feed displacement versus tube forming pressure schedule was studied to optimize the forming process operation to reduce thinning. Validation of the numerical simulations was performed by comparison of the predicted strain distributions and thinning, with measured quantities. The effect of element formulation (thin shell versus solid elements) was also considered in the models.

  12. Crashworthiness of Aluminium Tubes; Part 1: Hydroforming at Different Corner-Fill Radii and End Feeding Levels

    SciTech Connect

    D'Amours, Guillaume; Rahem, Ahmed; Williams, Bruce

    2007-05-17

    The automotive industry, with an increasing demand to reduce vehicle weight through the adoption of lightweight materials, requires a search of efficient methods that suit these materials. One attractive concept is to use hydroforming of aluminium tubes. By using FE simulations, the process can be optimized to reduce the risk for failure while maintaining energy absorption and component integrity under crash conditions. It is important to capture the level of residual ductility after forming to allow proper design for crashworthiness. This paper presents numerical and experimental studies that have been carried out for high pressure hydroforming operations to study themore » influence of the tube corner radius, end feeding, material thinning, and work hardening in 76.2 mm diameter, 3 mm wall thickness AA5754 aluminium alloy tube. End feeding was used to increase the formability of the tubes. The influence of the end feed displacement versus tube forming pressure schedule was studied to optimize the forming process operation to reduce thinning. Validation of the numerical simulations was performed by comparison of the predicted strain distributions and thinning, with measured quantities. The effect of element formulation (thin shell versus solid elements) was also considered in the models.« less

  13. [Intraoperative placement of transnasal small intestinal feeding tube during the surgery in 5 cases with high position intestinal obstruction and postoperative feeding].

    PubMed

    Duan, Guang-qi; Zhang, Min; Guan, Xiao-hao; Yin, Zhi-qing

    2012-09-01

    To explore the value of employing the small intestinal feeding tube in treating high position intestinal obstruction of newborn infant. Five newborn infants (3 males and 2 females; 1 premature infant and 4 fully-mature infants; 2 had membranous atresia of duodenum, 1 had annular pancreas, and 2 had proximal small intestine atresia; 1 infant had malrotation). The duodenal membrane-like atresia and the blind-end of small intestine were removed and intestinal anastomosis was performed, which was combined with intestinal malrotation removal. Before the intestinal anastomosis surgery, the anesthetist inserted via nose a 6Fr small intestinal ED tube, made by CREATE MEDIC CO LTD of Japan[ the State Food and Drug Administration-instrument (Im.) 2007-NO.2661620]. Twenty-four hours after surgery, abdominal X-ray plain film was taken and patients were fed with syrup; 48 hours later, formula milk was pumped or lactose-free milk amino acids were given by intravenous injection pump through the feeding tube. The amount of milk and fluids was gradually increased to normal amount according to the condition. In initial 3 days the intravenous nutrition was given and one week after operation, the infants were fed through mouth in addition to pumping milk through the tube and stopped infusion. Ten to 22 days after operation, the tube was removed and the infant patients were discharged. All the five infants showed that the feeding through the nutrition tube was accomplished and the time of venous nutrition was reduced and fistula operation was avoided. None of the infants on question was off the tube and no jaundice exacerbation was found and the liver function was also found normal. At the very beginning, the tube was occasionally blocked by milk vale in one infant and after 0.9% sodium chloride solution flushing patency restored. After that, the feeding tube was washed once with warm water after feeding. In one infant vomiting occurred due to enough oral milk. The photograph of upper

  14. Commercial enteral formulas and nutrition support teams improve the outcome of home enteral tube feeding.

    PubMed

    Klek, Stanislaw; Szybinski, Piotr; Sierzega, Marek; Szczepanek, Kinga; Sumlet, Magdalena; Kupiec, Monika; Koczur-Szozda, Elzbieta; Steinhoff-Nowak, Malgorzata; Figula, Krzysztof; Kowalczyk, Tomasz; Kulig, Jan

    2011-05-01

    The benefits of home enteral tube feeding (HETF) provided by nutrition support teams (NSTs) have been questioned recently, given the growing costs to the healthcare system. This study examined the effect of a specialized home enteral nutrition program on clinical outcome variables in HETF patients. The observational study included 203 patients (103 women, 100 men; mean age 52.5 years) receiving HETF with homemade diets for at least 12 months before starting a specialized home nutrition program for another 12 months consisting of provision of commercial enteral formulas and the guidance of an NST. Both study periods were compared regarding the number of hospital admissions, length of hospital and intensive care unit (ICU) stay, and costs of hospitalization. A specialized HETF program significantly reduced the number of hospital admissions and the duration of hospital and ICU stays. The need for hospitalization and ICU admission was significantly reduced, with odds ratios of 0.083 (95% confidence interval, 0.051-0.133, P < .001) and 0.259 (95% confidence interval, 0.124-0.539, P < .001), respectively. Specialized HETF was associated with a significant decrease in the prevalence of pneumonia (24.1% vs 14.2%), respiratory failure (7.3% vs 1.9%), urinary tract infection (11.3% vs 4.9%), and anemia (3.9% vs 0%) requiring hospitalization. The average yearly cost of hospital treatment decreased from $764.65 per patient to $142.66 per year per patient. The specialized HETF care program reduces morbidity and costs related to long-term enteral feeding at home.

  15. Medication Errors in Patients with Enteral Feeding Tubes in the Intensive Care Unit.

    PubMed

    Sohrevardi, Seyed Mojtaba; Jarahzadeh, Mohammad Hossein; Mirzaei, Ehsan; Mirjalili, Mahtabalsadat; Tafti, Arefeh Dehghani; Heydari, Behrooz

    2017-01-01

    Most patients admitted to Intensive Care Units (ICU) have problems in using oral medication or ingesting solid forms of drugs. Selecting the most suitable dosage form in such patients is a challenge. The current study was conducted to assess the frequency and types of errors of oral medication administration in patients with enteral feeding tubes or suffering swallowing problems. A cross-sectional study was performed in the ICU of Shahid Sadoughi Hospital, Yazd, Iran. Patients were assessed for the incidence and types of medication errors occurring in the process of preparation and administration of oral medicines. Ninety-four patients were involved in this study and 10,250 administrations were observed. Totally, 4753 errors occurred among the studied patients. The most commonly used drugs were pantoprazole tablet, piracetam syrup, and losartan tablet. A total of 128 different types of drugs and nine different oral pharmaceutical preparations were prescribed for the patients. Forty-one (35.34%) out of 116 different solid drugs (except effervescent tablets and powders) could be substituted by liquid or injectable forms. The most common error was the wrong time of administration. Errors of wrong dose preparation and administration accounted for 24.04% and 25.31% of all errors, respectively. In this study, at least three-fourth of the patients experienced medication errors. The occurrence of these errors can greatly impair the quality of the patients' pharmacotherapy, and more attention should be paid to this issue.

  16. Comparison of intraoperative versus delayed enteral feeding tube placement in patients undergoing a Whipple procedure.

    PubMed

    Scaife, Courtney L; Hewitt, Kelly C; Mone, Mary C; Hansen, Heidi J; Nelson, Edward T; Mulvihill, Sean J

    2014-01-01

    The intraoperative placement of an enteral feeding tube (FT) during pancreaticoduodenectomy (PD) is based on the surgeon's perception of need for postoperative nutrition. Published preoperative risk factors predicting postoperative morbidity may be used to predict FT need and associated intraoperative placement. A retrospective review of patients who underwent PD during 2005-2011 was performed by querying the National Surgical Quality Improvement Program (NSQIP) database with specific procedure codes. Patients were categorized based on how many of 10 possible preoperative risk factors they demonstrated. Groups of patients with scores of ≤ 1 (low) and ≥ 2 (high), respectively, were compared for FT need, length of stay (LoS) and organ space surgical site infections (SSIs). Of 138 PD patients, 82 did not have an FT placed intraoperatively, and, of those, 16 (19.5%) required delayed FT placement. High-risk patients were more likely to require a delayed FT (29.3%) compared with low-risk patients (9.8%) (P = 0.026). The 16 patients who required a delayed FT had a median LoS of 15.5 days, whereas the 66 patients who did not require an FT had a median LoS of 8 days (P < 0.001). In this analysis, subjects considered as high-risk patients were more likely to require an FT than low-risk patients. Assessment of preoperative risk factors may improve decision making for selective intraoperative FT placement. © 2013 International Hepato-Pancreato-Biliary Association.

  17. Medication administration via enteral feeding tube: a survey of pharmacists' knowledge.

    PubMed

    Joos, Elke; Verbeke, Stacey; Mehuys, Els; Van Bocxlaer, Jan; Remon, Jean Paul; Van Winckel, Myriam; Boussery, Koen

    2016-02-01

    Medication administration to patients with an enteral feeding tube (EFT) is complex and prone to errors. Community pharmacists may be ideally placed to provide training and advice on this topic in individual patients as well as in institutions supplied by the pharmacy. To assess community pharmacists’ knowledge on guideline recommendations regarding medication preparation and administration through EFT. Knowledge of guideline recommendations was assessed using a 15-item self-administered online questionnaire (April–June 2014). Questions reflected key aspects of guideline recommendations on medication administration via EFT. All graduated community pharmacists from the Dutch-speaking part of Belgium were eligible for participation. A total of 105 community pharmacists completed the questionnaire. Median self-perceived knowledge of medication administration via EFT was 2 (on a 0–10 scale). On average 5.2 (SD 2.6) out of the 15 questions were answered correctly. Strikingly, the ability to select suspensions in a list of liquid medications and knowledge on crushability of solid dosage forms were low. Our findings demonstrate that pharmacists’ knowledge on correct medication administration via EFT is too limited to be able to provide good advice to EFT patients or their caregivers. Tailored training on this topic is needed.

  18. Fundoplication and gastrostomy versus image-guided gastrojejunal tube for enteral feeding in neurologically impaired children with gastroesophageal reflux.

    PubMed

    Wales, Paul W; Diamond, Ivan R; Dutta, Sanjeev; Muraca, Sergio; Chait, Peter; Connolly, Bairbre; Langer, Jacob C

    2002-03-01

    Neurologically impaired children with gastroesophageal reflux (GER) usually are treated with a fundoplication and gastrostomy (FG); however, this approach is associated with a high rate of complications and morbidity. The authors evaluated the image-guided gastrojejunal tube (GJ) as an alternative approach for this group of patients. A retrospective review of 111 neurologically impaired patients with gastroesophageal reflux was performed. Patients underwent either FG (n = 63) or GJ (n = 48). All FGs were performed using an open technique by a pediatric surgeon, and all GJ tubes were placed by an interventional radiologist. The 2 groups were similar with respect to diagnosis, age, sex and indication for feeding tube. Patients in the GJ group were followed up for an average of 3.11 years, and those in the FG group for 5.71 years. The groups did not differ statistically with respect to most complications (bleeding, peritonitis, aspiration pneumonia, recurrent gastroesophageal reflux [GER], wound infection, failure to thrive, and death), subsequent GER related admissions, or cost. Children in the GJ group were more likely to continue taking antireflux medication after the procedure (P <.05). Also, there was a trend for GJ patients to have an increased incidence of bowel obstruction or intussusception (20.8% v 7.9%). Of the FG patients 36.5% experienced retching, and 12.7% experienced dysphagia. Eighty-five percent of patients in the GJ group experienced GJ tube-specific complications (breakage, blockage, dislodgment), and GJ tube manipulations were required an average of 1.68 times per year follow-up. Nine patients (14.3%) in the FG group had wrap failure, with 7 (11.1%) of these children requiring repeat fundoplication. In the GJ group, 8.3% of patients went on to require a fundoplication for persistent problems. A total of 14.5% of GJ patients had their tube removed by the end of the follow-up period because they no longer needed the tube for feeding. Image

  19. [Evaluation of serum total carnitine values in persons with severe motor and intellectual disabilities with enteral (tube) feeding].

    PubMed

    Ohtaki, Ushio; Ozawa, Hiroshi; Ishizuka, Takehiro; Kamiishi, Akiko; Sasaki, Kyoko; Nakajima, Suemi; Katayama, Ayako; Arimoto, Kiyoshi; Yagihashi, Tatsuhiko; Kimiya, Satoshi

    2012-09-01

    The nutritive evaluation and the serum carnitine values were measured for persons with severe motor and intellectual disabilities with enteral (tube) feeding. In Shimada Rehabilitation Center, twenty one people who had serum albumin levels of 3.4 g/dl or less, and were taking nutrition with enteral (tube) feeding, were tested. Body weight, blood samples, and serum carnitine levels were measured. The total carnitine value was less than the standard value in 19 patients. The total carnitine value decreased in the group taking valporate sodium (VPA), compared to the values from the group non-taking VPA. From our evaluation, we think that daily carnitine supplements is essential for persons with sever motor and intellectual disabilities taking VPA to maintain carnitine levels in the blood, and regular urine test should be done for earlier detection secondary lack complications from the secondary lack of carnitine.

  20. The effect of a natural food based tube feeding in minimizing diarrhea in critically ill neurological patients.

    PubMed

    Schmidt, Simone B; Kulig, Willibald; Winter, Ralph; Vasold, Antje S; Knoll, Anette E; Rollnik, Jens D

    2018-01-09

    Diarrhea has negative consequences for patients, health care staff and health care costs when neurological patients are fed enterally over long periods. We examined the effect of tube feeding with natural foods in reducing the number of fluid stool evacuations and diarrhea in critically ill neurological patients. A multicenter, prospective, open-label and randomized controlled trial (RCT) was conducted at facilities in Germany specializing in early rehabilitation after neurological damage. Patients of the INTERVENTION group were fed by tube using a commercially available product based on real foods such as milk, meat, carrots, whereas CONTROL patients received a standard tube-feed made of powdered raw materials. All received enteral nutrition over a maximum of 30 days. The number of defecations and the consistency of each stool according to the Bristol Stool Chart (BSC) were monitored. In addition, daily calories, liquids and antibiotic-use were recorded. 118 Patients who had suffered ischemic stroke, intracerebral hemorrhage, traumatic brain injury or hypoxic brain damage and requiring enteral nutrition were enrolled; 59 were randomized to receive the intervention and 59 control feed. There were no significant differences in clinical screening data, age, sex, observation period or days under enteral nutrition between the groups. Patients in both groups received equivalent amount of calories and fluids. In both groups antibiotics were frequently prescribed (69.5% in the INTERVENTION group and 75.7% in the CONTROL group) for 10-11 days on average. In comparison to the CONTROL group, patients in the INTERVENTION group had a significant reduction of the number of watery stool evacuations (type 7 BSC) (minus 61%, IRR = 0.39, p < 0.001). Further statistical evaluations using the following corrections: major diarrhea-associated confounders (number and duration of antibiotics); shorter observation period of 15 days; excluding patients with Clostridiumdifficile

  1. Enteral Feeding Tube Clogging: What Are the Causes and What Are the Answers? A Bench Top Analysis.

    PubMed

    Garrison, Christopher M

    2018-02-01

    Clogged enteral feeding tubes remain a significant barrier to the delivery of nutrition, hydration, and medications to patients who cannot tolerate oral intake. There is limited research that compares the relative efficacy of different methods used to clear a clogged feeding tube. The objectives of this study were to better understand the factors that contribute to enteral feeding tube clogging and to test the efficacy of 3 methods for clearing clogged feeding tubes. Three formulations of clogs were artificially created and tested in vitro and composed of various quantities of crushed medication (ie, aspirin) and 0.15 g coagulated protein (ie, tofu). The following 3 clog clearing strategies were tested on all clog types (n = 5 clogs/formulation/treatment): warm water flushes, an enzyme treatment, and an actuated mechanical occlusion clearing device. The variable among the clog types that appears most responsible for decreased clearing success is the state of the coagulated protein. Dried-out protein appears to makes a greater difference than increasing the medication quantity. The actuated mechanical occlusion clearing device was significantly more successful (93%) when compared with warm water flushes (20%) and the commercially available enzyme treatment (33%; P < .005) at clearing the clogs. The actuated device required significantly less total procedure time (P < .005) and total nursing time (P < .005) when compared with the other 2 clearing methods. When clogs occur, they can be quickly and effectively resolved by the actuated device, but other methodologies such as water and enzyme treatments may be of assistance. © 2018 American Society for Parenteral and Enteral Nutrition.

  2. Continuous nasogastric tube feeding: monitoring by combined use of refractometry and traditional gastric residual volumes.

    PubMed

    Chang, W-K; McClave, S-A; Chao, Y-C

    2004-02-01

    Traditional use of gastric residual volumes (GRVs) is insensitive and cannot distinguish retained enteral formula from the large volume of endogenous secretions. We designed this prospective study to determine whether refractometry and Brix value (BV) measurements could be used to monitor gastric emptying and tolerance in patients receiving continuous enteral feeding. Thirty-six patients on continuous nasogastric tube feeding were divided into two groups; patients with lower GRVs (<75 ml) in Group 1, patients with higher GRVs (>75 ml) in Group 2. Upon entry, all gastric contents were aspirated, the volume was recorded (Asp GRV), BV measurements were made by refractometry, and then the contents were reinstilled but diluted with 30 ml additional water. Finally, a small amount was reaspirated and repeat BV measurements were made. Three hours later, the entire procedure was repeated a second time. The BV ratio, calculated (Cal) GRV, and volume of formula remaining were calculated by derived equations. Mean BV ratios were significantly higher for those patients in Group 2 compared to those in Group 1. All but one of the 22 patients (95%) in Group 1 had a volume of formula remaining in the stomach estimated on both measurements to be less than the hourly infusion rate (all these patients had BV ratios <70%). In contrast, six of the 14 patients in Group 2 (43%) on both measurements were estimated to have volumes of formula remaining that were greater than the hourly infusion rate (all these patients had BV ratios >70%). Three of the Group 2 patients (21%) whose initial measurement showed evidence for retention of formula, improved on repeat follow-up measurement assuring adequate gastric emptying. The remaining five patients from Group 2 (35%) had a volume of formula remaining that was less than the hourly infusion rate on both measurements. The pattern of Asp GRVs and serial pre- and post-dilution BVs failed to differentiate these patients in Group 2 with potential

  3. Treatment of spontaneous esophageal rupture with transnasal thoracic drainage and temporary esophageal stent and jejunal feeding tube placement.

    PubMed

    Wu, Gang; Zhao, Yan Shi; Fang, Yi; Qi, Yu; Li, Xiangnan; Jiao, Dechao; Ren, Kewei; Han, Xinwei

    2017-01-01

    Spontaneous rupture of the esophagus is a rare but life-threatening thoracic emergency, with high rates of clinical misdiagnosis and mortality. This article summarizes our experience in the treatment of spontaneous esophageal rupture with transnasal thoracic drainage and temporary esophageal stent and jejunal feeding tube placement. We retrospectively assessed the medical records of 19 patients with spontaneous esophageal rupture treated using our intervention protocol. Patients received local anesthesia and sedation prior to undergoing transnasal drainage catheter placement into the thoracic abscess cavity, followed by temporary esophageal stent and jejunal feeding tube placement. After the operation, abscess lavage, nutritional support, and anti-inflammatory treatment were given. The transnasal thoracic drainage catheter, esophageal stent, and feeding tube were removed after the healing of the abscess cavity. In all, 19 covered esophageal stents were placed in 19 patients with spontaneous esophageal rupture. All operations were technically successful. After an average of 84.06 days, the stents were successfully removed from 17 patients. No cases of massive hemorrhage, esophageal rupture, or other complications occurred during stent removal. An 82-year-old patient died of heart failure 2 months after the operation. One patient died of sudden massive hematemesis and hematochezia 55 days after the operation. In one patient, the esophageal injury failed to heal completely. Our treatment protocol is simple, minimally invasive, and efficacious and may be an alternative for patients who are not candidates for surgery, have a high risk of postoperative complications, or wish to undergo minimally invasive surgery. Therapeutic study, level V.

  4. What Is the Evidence for Use of a Supplemental Feeding Tube Device as an Alternative Supplemental Feeding Method for Breastfed Infants?

    PubMed

    Penny, Frances; Judge, Michelle; Brownell, Elizabeth; McGrath, Jacqueline M

    2018-02-01

    According to the Healthy People 2020 goals, the sustainability of breastfeeding duration rates within the United States has not been achieved. To increase these rates, it is important that women with breastfeeding difficulties receive the support needed to continue breastfeeding. When supplementation occurs, it is essential that the breastfeeding relationship be preserved. Various methods of supplementation are often recommended including use of the supplemental feeding tube device (SFTD). The question guiding this brief is "What evidence exists to support the use of an SFTD as a method of supplementation for breastfed infants?" The PubMed and CINAHL databases were queried for original research published in English from 1990 through July 2016. Search terms included "supplemental feeding tube," "breastfeeding," "term infants," "premature infants," "Supplemental Nursing System," "Lact-aid," and "supply line." Very limited research exists on the use of SFTDs as a method of supplementation for breastfed infants; however, existing research suggests that an SFTD may be useful as a supplementation method for breastfed infants. High-quality research is needed to evaluate the efficacy of using an SFTD for supporting exclusive and all breastfeeding rates. Nurses and providers need to be educated and trained in the use of SFTDs as well as all supplemental feeding methods. Information on efficacy and SFTD use should also be included in policies related to breastfeeding and human milk use. Further research should determine best methods of supplementation for breastfed infants and should examine differences in breastfeeding rates when using the SFTD for supplementation.

  5. Therapeutic amnioinfusion for intrapartum fetal distress using a pediatric feeding tube.

    PubMed

    Abdel-Aleem, H; Amin, A F; Shokry, M; Radwan, R A

    2005-08-01

    To evaluate the role of therapeutic amnioinfusion using a pediatric feeding tube in cases of intrapartum fetal distress. A randomized clinical trial including 438 women admitted in labor at Assiut University Hospital with nonreassuring fetal heart rate tracing. Using sealed opaque envelopes, the women were randomized to 2 groups. In the amnioinfusion group they underwent transcervical amnioinfusion (1000 mL of warmed sterile saline solution) in addition to conventional treatment. In the control group they received conventional treatment only. The primary outcome was cesarean section rate for fetal distress. The secondary outcomes were neonatal and maternal complications. The amnioinfusion group showed a significant reduction in the rate of cesarean section for fetal distress (relative risk [RR], 0.7; 95% confidence interval [CI], 0.6-0.83), and a 30% reduction in abnormal fetal heart rate patterns (RR, 0.7; 95% CI, 0.6-0.83). Significantly fewer newborns had Apgar scores less than 7 at 1 and 5 min in the amnioinfusion group than in the control group (RR, 0.38; 95% CI, 0.26-0.55 and RR, 0.31; 95% CI, 0.15-0.64, respectively). Significantly fewer newborns had meconium below the vocal cords in the amnioinfusion group than in the control group (RR, 0.36; 95% CI, 0.13-0.97). Moreover, 14 newborns in the amnioinfusion group needed admission to the intensive care unit vs. 31 newborns in the control group. There were no significant differences between the 2 groups regarding the incidence rates of uterine hypertonus and maternal temperature higher than 38 degrees C. Therapeutic amnioinfusion is a simple and effective intervention that reduces the rates of cesarean section for intrapartum nonreassuring fetal heart tracing. In under-resourced settings, it can be performed using inexpensive catheters.

  6. Pancreatic enzymes prepared in bicarbonate solution for administration through enteral feeding tubes.

    PubMed

    Boullata, Angela M; Boullata, Joseph I

    2015-07-15

    The dissolution and physicochemical effects of preparing delayed-release pancrelipase in a sodium bicarbonate solution before administration via an enteral feeding tube were studied. Several doses of four delayed-release pancrelipase products (Creon, Pancreaze, Ultresa, Zenpep) were studied. The intact contents of pancrelipase capsules was added to 20 mL of 8.4% sodium bicarbonate solution to dissolve the enteric coating and liberate the enzymes into solution. In addition to visual observation, the pH, relative particle count, and osmolality of each admixture were assessed immediately and 5, 10, 20, and 30 minutes after admixture preparation. The only dose of Creon that was completely dissolved at 30 minutes was the 24,000 lipase unit dose. None of the doses of Pancreaze and only the lowest dose (23,000 lipase units) of Ultresa were completely dissolved at 30 minutes. However, Zenpep doses of 20,000 and 40,000 lipase units were completely dissolved 30 minutes after preparation. Higher doses of each pancrelipase product did not completely dissolve. The baseline pH of the solvent decreased slightly at the first few time points after pancrelipase was added. The relative particle count increased over time and with increasing doses. The osmolality of the mixtures varied by pancrelipase product. The dissolution of enteric coated granules in sodium bicarbonate varied with the pancrelipase product and dose. Zenpep 40,000 lipase units was found to most efficiently dissolve in sodium bicarbonate, possibly due to the consistent size of the product's granules and visibly thinner and uniform enteric coating. Copyright © 2015 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  7. Analysis of drug use in institutionalized individuals with intellectual disability and tube feeding.

    PubMed

    Joos, Elke; Mehuys, Els; Remon, Jean Paul; Van Winckel, Myriam; Boussery, Koen

    2016-04-01

    Little is known about the medication used by people with intellectual disabilities (ID) and enteral feeding tube (EFT). However, in light of the complexity associated with drug administration through EFT, data on medication use in this population may be helpful in the development of practical guidelines and staff training initiatives. A cross-sectional, observational study was conducted in six Belgian residential care facilities (RCFs) for individuals with ID. Anonymized medication records of all residents receiving chronic medication through EFT were collected (n = 156). All chronic drugs were categorized according to the ATC classification, and medication records were checked for potential major drug-drug interactions (DDI). The 156 residents used a total of 1029 chronic drugs via EFT, with a median of six drugs per resident (range 1-14). A total of 148 different drug molecules were identified, belonging to 38 main ATC therapeutic groups (ATC level 2). Antiepileptics, drugs for constipation and drugs for acid-related disorders were the most frequently used groups. Seventy-four of the 156 screened medication records (47%) contained at least one potential DDI; in total, 116 potential interactions were identified, which represent 38 different interacting drug pairs. This study describes medication use through EFT among people with ID in Belgian RCFs, with antiepileptics being the most frequently used group. Our study also demonstrated that a high number of drugs is administered through EFT, and that the number of potential DDIs is high. These observations warrant an increased attention for drug administration through the EFT in individuals with ID.

  8. Enteral tube feeding of patients with acute stroke: when does the risk of diarrhoea increase?

    PubMed

    Arevalo-Manso, J J; Martinez-Sanchez, P; Juarez-Martin, B; Fuentes, B; Ruiz-Ares, G; Sanz-Cuesta, B E; Parrilla-Novo, P; Diez-Tejedor, E

    2014-12-01

    We aimed to evaluate the relationship between the length of time acute stroke patients underwent enteral tube feeding (ETF) and episodes of diarrhoea, and to investigate the temporal cut-off point at which diarrhoea risk increases. An observational, retrospective study was conducted on patients with acute stroke admitted to a Stroke Centre. Patients undergoing ETF (ETF group) and those not undergoing ETF (control group) were analysed and matched by age and stroke severity. Data regarding demographic and clinical variables were recorded. The analysis was conducted using a receiver operating characteristic (ROC) curve and multivariate analyses. A total of 130 inpatients was included (age 75.08 ± 11.53 years, 56.2% men). The ETF group had higher diarrhoea frequency (27.7% vs 6.2%, P = 0.001). The length of time on ETF was associated with diarrhoea development (odds ratio (OR), 1.12 increment per day; 95% confidence interval (CI) 1.05-1.18; P < 0.001), after adjusting for confounders. The ROC curve showed 7 days on ETF as a cut-off point for diarrhoea risk. Seven days or more on ETF was independently associated with diarrhoea (OR, 6.26; 95% CI 1.66-23.62; P = 0.007), whereas less than 7 days was not when compared with the control group (OR, 0.38; 95% CI 0.04-3.91; P = 0.413). The length of time on ETF is associated with diarrhoea development in patients with acute stroke, demonstrating a temporal cut-off point. Seven days or longer on ETF is related to the occurrence of diarrhoea, whereas less than 7 days on ETF does not show this effect. © 2014 The Authors; Internal Medicine Journal © 2014 Royal Australasian College of Physicians.

  9. The effect of enteral tube feeding in cystic fibrosis: A registry based study.

    PubMed

    Libeert, Denis; Declercq, Dimitri; Wanyama, Simeon; Thomas, Muriel; Van Daele, Sabine; De Baets, Frans; Van Biervliet, Stephanie

    2018-03-01

    Long-term effect of enteral tube feeding (ETF) in cystic fibrosis (CF) remains equivocal. A Belgian CF registry based, retrospective, longitudinal study, evaluated the pre- and post- ETF (n = 113) clinical evolution and compared each patient with 2 age, gender, pancreatic status and genotype class-matched controls. At baseline ETF had a worse BMI z-score (p < 0.0001) and FEV1% (p < 0.0001) compared to controls. Patients eventually receiving ETF, had already a significant worse nutritional status and pulmonary function at first entry in the registry. Both parameters displayed a significant decline before ETF-introduction. ETF had more hospitalization and intravenous antibiotic (IVAB) treatment days (p < 0.0001). After ETF introduction hospitalizations and IVAB decreased significantly. After ETF-introduction BMI z-score recuperated towards the original curve before the decline, but remained below the controls. Starting ETF had no effect on rate of height gain in children. The pre-index FEV1 decline (-1.52%/year (p = 0.002)) stabilized to +0.39%/year afterwards. Controls displayed decline of -0.48%/year (p < 0.0001). ETF introduction improved BMI z-score and stabilized FEV1, associated with less hospitalizations and IVAB treatments. Higher mortality and transplantation in the ETF cases, leading to drop-outs, made determination of the effect size difficult. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  10. Percutaneous endoscopic gastrostomy versus nasogastric tube feeding for patients with head and neck cancer: a systematic review

    PubMed Central

    Wang, Jinfeng; Liu, Minjie; Liu, Chao; Ye, Yun; Huang, Guanhong

    2014-01-01

    There are two main enteral feeding strategies—namely nasogastric (NG) tube feeding and percutaneous gastrostomy—used to improve the nutritional status of patients with head and neck cancer (HNC). But up till now there has been no consistent evidence about which method of enteral feeding is the optimal method for this patient group. To compare the effectiveness of percutaneous gastrostomy and NGT feeding in patients with HNC, relevant literature was identified through Medline, Embase, Pubmed, Cochrane, Wiley and manual searches. We included randomized controlled trials (RCTs) and non-experimental studies comparing percutaneous gastrostomy—including percutaneous endoscopic gastrostomy (PEG) and percutaneous fluoroscopic gastrostomy (PFG) —with NG for HNC patients. Data extraction recorded characteristics of intervention, type of study and factors that contributed to the methodological quality of the individual studies. Data were then compared with respect to nutritional status, duration of feeding, complications, radiotherapy delays, disease-free survival and overall survival. Methodological quality of RCTs and non-experimental studies were assessed with separate standard grading scales. It became apparent from our studies that both feeding strategies have advantages and disadvantages. PMID:24453356

  11. Percutaneous endoscopic gastrostomy versus nasogastric tube feeding for patients with head and neck cancer: a systematic review.

    PubMed

    Wang, Jinfeng; Liu, Minjie; Liu, Chao; Ye, Yun; Huang, Guanhong

    2014-05-01

    There are two main enteral feeding strategies-namely nasogastric (NG) tube feeding and percutaneous gastrostomy-used to improve the nutritional status of patients with head and neck cancer (HNC). But up till now there has been no consistent evidence about which method of enteral feeding is the optimal method for this patient group. To compare the effectiveness of percutaneous gastrostomy and NGT feeding in patients with HNC, relevant literature was identified through Medline, Embase, Pubmed, Cochrane, Wiley and manual searches. We included randomized controlled trials (RCTs) and non-experimental studies comparing percutaneous gastrostomy-including percutaneous endoscopic gastrostomy (PEG) and percutaneous fluoroscopic gastrostomy (PFG) -with NG for HNC patients. Data extraction recorded characteristics of intervention, type of study and factors that contributed to the methodological quality of the individual studies. Data were then compared with respect to nutritional status, duration of feeding, complications, radiotherapy delays, disease-free survival and overall survival. Methodological quality of RCTs and non-experimental studies were assessed with separate standard grading scales. It became apparent from our studies that both feeding strategies have advantages and disadvantages.

  12. Association of a Proactive Swallowing Rehabilitation Program With Feeding Tube Placement in Patients Treated for Pharyngeal Cancer.

    PubMed

    Ajmani, Gaurav S; Nocon, Cheryl C; Brockstein, Bruce E; Campbell, Nicholas P; Kelly, Amy B; Allison, Jamie; Bhayani, Mihir K

    2018-04-19

    A proactive speech and language pathology (SLP) program is an important component of the multidisciplinary care of patients with head and neck squamous cell carcinoma (HNSCC). Swallowing rehabilitation can reduce the rate of feeding tube placement, thereby significantly improving quality of life. To evaluate the initiation of a proactive SLP rehabilitation program at a single institution and its association with rates of feeding tube placement and dietary intake in patients with HNSCC. Cohort study at a tertiary care and referral center for patients with HNSCC serving the northern Chicago region. Patients were treated for squamous cell carcinomas of the hypopharynx, oropharynx, and nasopharynx from 2004 to 2015 with radiation or chemoradiation therapy in the definitive or adjuvant setting. Patients who received less than 5000 cGy radiation or underwent reirradiation were excluded. A proactive SLP program for patients with HNSCC was initiated in 2011. Study cohorts were divided into 2 groups: 2004 through 2010 and 2011 through 2015. Primary outcome variables were SLP referral placement and timing of the referral. Secondary outcomes were feeding tube placement and ability to tolerate any oral intake. A total of 254 patients met inclusion criteria (135 before and 119 after implementation of SLP program; median age, 60 years [range, 14-94 years]; 77% male). With the initiation of a proactive SLP program, pretreatment evaluations increased from 29 (21.5%) to 70 (58.8%; risk ratio [RR], 2.74; 95% CI, 1.92-3.91), and rate of referral overall at any time increased from 60.0% to 79.8% (RR, 1.33; 95% CI, 1.13-1.57). Feeding tube placement rates decreased from 45.9% (n = 62) to 29.4% (n = 35; RR, 0.64; 95% CI, 0.46-0.89). Among patients receiving a swallow evaluation, feeding tube requirements were less frequent for those receiving a pretreatment evaluation (31 of 99 [31%]) than for those referred during (11 of 18 [61%]) or after (38 of 59 [64%]) treatment. The rate

  13. The effect of gastrostomy tube feeding on body protein and bone mineralization in children with quadriplegic cerebral palsy.

    PubMed

    Arrowsmith, Fiona; Allen, Jane; Gaskin, Kevin; Somerville, Helen; Clarke, Samantha; O'Loughlin, Edward

    2010-11-01

    The aim of this study was to investigate the effect of gastrostomy tube feeding on body protein and bone mineralization in malnourished children with cerebral palsy (CP). Children aged between 4 and 18 years with spastic quadriplegic CP (Gross Motor Function Classification System level V) were recruited from the Children's Hospital at Westmead to participate in this prospective cohort study. The children had measurements of anthropometry (weight, height, and skinfold), bone mineral content (BMC) by dual-energy X-ray absorptiometry, and total body protein (TBP) by neutron activation analysis before and after gastrostomy tube feeding. Comparison data were collected prospectively from age-matched healthy children and extracted from databases for this study. A total of 21 children (nine females, 12 males) participated in the study (median age 8 y 5 mo; interquartile range [IQR] 6 y 9 mo-11 y 10 mo). The median length of time of gastrostomy feeding was 19.4 months (IQR 7.7-29.9 mo). Significant (p<0.05) improvements were found in the median values for weight (15.4-23.3 kg), weight standard deviation scores (SDS; -4.8 to -3.0), height (105.4-118.3 cm), per cent body fat (10.7-16.3), TBP (2.4-3.4 kg), TBP per cent predicted for height (83.4-99.0), and BMC (469-626 g). No significant increases were found in height SDS, TBP per cent predicted for age, or BMC SDS for age or height. Malnourished children with quadriplegic CP showed significant increases in body fat and protein with gastrostomy tube feeding. No significant change in bone mineralization predicted for age or height was observed. © The Authors. Journal compilation © Mac Keith Press 2010.

  14. Electromagnetic-guided placement of nasoduodenal feeding tubes versus endoscopic placement: a randomized, multicenter trial.

    PubMed

    Kappelle, Wouter F W; Walter, Daisy; Stadhouders, Paul H; Jebbink, Hendrik J A; Vleggaar, Frank P; van der Schaar, Peter J; Kappelle, Jan Willem; van der Tweel, Ingeborg; Van den Broek, Medard F M; Wessels, Frank J; Siersema, Peter D; Monkelbaan, Jan F

    2018-01-01

    Electromagnetic-guided placement (EMP) of a nasoduodenal feeding tube by trained nurses is an attractive alternative to EGD-guided placement (EGDP). We aimed to compare EMP and EGDP in outpatients, ward patients, and critically ill patients with normal upper GI anatomy. In 3 centers with no prior experience in EMP, patients were randomized to placement of a single-lumen nasoduodenal feeding tube either with EGDP or EMP. The primary endpoint was post-pyloric position of the tube on abdominal radiography. Patients were followed for 10 days to assess patency and adverse events. The analyses were performed according to the intention-to-treat principle. In total, 160 patients were randomized to EGDP (N = 76) or EMP (N = 84). Three patients withdrew informed consent, and no abdominal radiography was performed in 2 patients. Thus, 155 patients (59 intensive care unit, 38%) were included in the analyses. Rates of post-pyloric tube position between EGDP and EMP were comparable (79% vs 82%, odds ratio 1.16; 90% confidence interval, 0.58-2.38; P = .72). Adverse events were observed in 4 patients after EMP (hypoxia, GI blood loss, atrial fibrillation, abdominal pain) and in 4 after EGDP (epistaxis N = 2, GI blood loss, hypoxia). Costs of tube placements were lower for EMP compared with EGDP: $519.09 versus $622.49, respectively (P = .04). Success rates and safety of EMP and EGDP in patients with normal upper GI anatomy were comparable. Lower costs and potential logistic advantages may drive centers to adopt EMP as their new standard of care. (Clinical trial registration number: NTR4286.). Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  15. Valve for abrasive material

    DOEpatents

    Gardner, Harold S.

    1982-01-01

    A ball valve assembly for controlling the flow of abrasive particulates including an enlarged section at the bore inlet and an enlarged section at the bore outlet. A refractory ceramic annular deflector is positioned in each of the enlarged sections, substantially extending the useful life of the valve.

  16. Prevalence, Outcomes, and Management of Enteral Tube Feeding Intolerance: A Retrospective Cohort Study in a Tertiary Center.

    PubMed

    Wang, Kailun; McIlroy, Kerry; Plank, Lindsay D; Petrov, Max S; Windsor, John A

    2017-08-01

    Enteral tube feeding (ETF) is the most common form of artificial feeding in hospitalized patients, and the development of intolerance (ETFI) is the most common complication. This study aimed to determine the prevalence of ETFI, the clinical consequences, and the current management approach to ETFI in hospitalized adult patients. Adult patients receiving ETF were identified from a prospective database in the Nutrition Services at Auckland City Hospital. Further information was obtained by the review of clinical records for a 12-month period, up to December 2014. The prevalence of ETFI was 33% among 754 patients. ETFI more frequently occurred in the intensive care unit ( P < .05). Patients with ETFI were less likely to reach their feeding goal rate ( P < .01). Multivariate analysis showed that younger age, certain specialties, and acute mesenteric ischemia were independent predictors of ETFI ( P < .05). The management of ETFI was highly variable. Medication was the most common treatment, while changes in the feeding protocol such as reducing infusion rate and stopping and changing the route of ETF were also frequently attempted. ETFI is a frequent problem in adult hospitalized patients receiving ETF, and it is associated with poor clinical outcomes such as inadequate nutrition and complications of feeding. While the pathophysiology is poorly understood, there also appears to be no standard evidence-based treatment. Studies investigating the mechanisms and optimized management are therefore indicated.

  17. Atmospheric particulate emissions from dry abrasive blasting using coal slag.

    PubMed

    Kura, Bhaskar; Kambham, Kalpalatha; Sangameswaran, Sivaramakrishnan; Potana, Sandhya

    2006-08-01

    Coal slag is one of the widely used abrasives in dry abrasive blasting. Atmospheric emissions from this process include particulate matter (PM) and heavy metals, such as chromium, lead, manganese, nickel. Quantities and characteristics of PM emissions depend on abrasive characteristics and process parameters. Emission factors are key inputs to estimate emissions. Experiments were conducted to study the effect of blast pressure, abrasive feed rate, and initial surface contamination on total PM (TPM) emission factors for coal slag. Rusted and painted mild steel surfaces were used as base plates. Blasting was carried out in an enclosed chamber, and PM was collected from an exhaust duct using U.S. Environment Protection Agency source sampling methods for stationary sources. Results showed that there is significant effect of blast pressure, feed rate, and surface contamination on TPM emissions. Mathematical equations were developed to estimate emission factors in terms of mass of emissions per unit mass of abrasive used, as well as mass of emissions per unit of surface area cleaned. These equations will help industries in estimating PM emissions based on blast pressure and abrasive feed rate. In addition, emissions can be reduced by choosing optimum operating conditions.

  18. A protocol of early aggressive acceleration of tube feeding increases ileus without perceptible benefit in severely burned patients.

    PubMed

    Kesey, Jennifer; Dissanaike, Sharmila

    2013-01-01

    Optimal nutrition is essential to the recovery of burned patients. The authors evaluated the efficacy of an aggressive nutrition delivery protocol. The following protocol was implemented: initiation of tube feeds within 4 hours, acceleration to goal rate within 8 hours, and tolerance of gastric residual volumes of 400 ml. Patients on the protocol formed the study group whereas patients admitted immediately before implementation served as controls for a study period of 7 days after admission. Outcome variables included ileus, prokinetic medication use, intensive care unit and overall length of stay, ventilator days and mortality. Variables were compared using bivariate analysis. The 42 study subjects and 34 controls were similar at baseline. Time to initiation was similar (6.8 vs 9.4 hours; P = .226), however, goal rate was achieved much sooner in the study group (11.2 vs 20.9 hours; P < .001). Number of hours spent at goal was different on days 1 and 2 (6.62 vs 2.74, P = .003 and 17.24 vs 13.18, P = .032) with no difference thereafter. Residual volumes in the study group were higher from day 2 onward, and remained increased throughout the study period (401 vs 234 ml average; P = .449). Clinical ileus was much more common in the study group (8 cases vs 1, P = .037). There was no difference in length of stay or mortality. The protocol was successfully implemented and resulted in early achievement of goal tube feed rates. However, this resulted in tube feed intolerance as manifested by more cases of clinical ileus.

  19. Use of proton pump inhibitors is associated with increased mortality due to nosocomial pneumonia in bedridden patients receiving tube feeding.

    PubMed

    Hamai, Kosuke; Iwamoto, Hiroshi; Ohshimo, Shinichiro; Wakabayashi, Yu; Ihara, Daisuke; Fujitaka, Kazunori; Hamada, Hironobu; Ono, Koichi; Hattori, Noboru

    2018-05-22

    To investigate the association between the use of proton pump inhibitors (PPI) and nosocomial pneumonia and gastrointestinal bleeding in bedridden patients receiving tube feeding. A total of 116 bedridden hospitalized patients receiving tube feeding, of which 80 were supported by percutaneous endoscopic gastrostomy and 36 by nasogastric tube, were included in the present study. The patients were divided into two groups: 62 patients treated with PPI (PPI group) and 54 patients without PPI (non-PPI group). Mortality due to nosocomial pneumonia was evaluated using the Kaplan-Meier approach and the log-rank test. A total of 36 patients (31%) died of nosocomial pneumonia during the observation period; the mortality rate due to nosocomial pneumonia was significantly higher in the PPI group than in the non-PPI group (P = 0.0395). Cox proportional hazard analysis showed that the use of PPI and lower levels of serum albumin were independent predictors of 2-year mortality due to nosocomial pneumonia. Gastrointestinal bleeding was observed in four patients in the non-PPI group (7.7%) and in one patient in the PPI group (1.6%); there was no significant difference between the two groups. The use of PPI in bedridden tube-fed patients was independently associated with mortality due to nosocomial pneumonia, and the PPI group had a non-significant lower incidence of gastrointestinal bleeding than the non-PPI group. Geriatr Gerontol Int 2018; ••: ••-••. © 2018 The Authors Geriatrics & Gerontology International published by John Wiley & Sons Australia, Ltd on behalf of Japan Geriatrics Society.

  20. [Implantation of ultra thin naso-duodenal and naso-jejunal tubes for feeding].

    PubMed

    Manegold, B C; Jung, M; Miceli, F; Schneider, K G

    1984-05-01

    Enteral nutrition through filiform naso-duodenal or naso-jejunal tubes with homogeneous low molecular nutritional solutions has a rather important place in therapy of different conditions; endoscopy can help to introduce these tubes into the intestinal tract in the following situations: A leak in the upper gastrointestinal tract, which may occur after surgical resections of the esophagus or stomach, or which may occur in rare cases after bouginage or after diagnostic procedures can be passed by with an ultrathin tube until it is healed of. Patients with stenotic lesions of the esophagus or the cardia, which can not be treated by surgery or conservative procedures like pertubation and dilation can be fed enterally if it is possible to move the tube beyond the stenosis. Patients with neurogenic swallowing dysfunction of different origine can be fed during long periods of time through such filiform naso-enteral tubes successfully and reach a perfect nutritional state. In acute treatment of Crohn's disease and other inflammatory intestinal diseases enteral nutrition through tubes is an essential therapeutic procedure.

  1. Abrasion resistant heat pipe

    DOEpatents

    Ernst, D.M.

    1984-10-23

    A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  2. Sniffin' Away the Feeding Tube - The Influence of Olfactory Stimulation on Oral Food Intake in Newborns and Premature Infants.

    PubMed

    Schriever, Valentin A; Gellrich, Janine; Rochor, Nora; Croy, Ilona; Cao-Van, Helene; Rüdiger, Mario; Hummel, Thomas

    2018-06-02

    Because of their immaturity many premature infants are fed via nasogastric tube. One objective of the neonatal care is to feed infants orally early. The olfactory function of premature infants is developed before birth and odorants have a significant impact on nutrition in infants. The aim of the study was to test whether odor stimulation has a positive effect on the transition from gavage to oral feeding in infants. Participants were premature infants with gestational age of more than 27 weeks, with full or partial gavage feeding, stable vital parameters and without invasive ventilation. Before each feeding procedure an odorant was presented in front of the infant's nose. Infants were randomized into one of three groups and received either rose odor (not food-associated), vanilla odor (food-associated) or placebo (no odor). The primary outcome of the study was defined as the time until complete oral nutrition. 150 children born at a postnatal age of 9.5±7.8 days were included in this study. The duration until complete oral nutrition was reached after 11.8±7.7 (vanilla), 12.2±7.7 (rose) and 12.9±8.8 (control) days. A nearly linear relation between odor presentation frequency and effect size was detectable. For infants that received the intervention for more than 66.7% of the time the length of gavage feeding (8±5.4) and hospitalization (11±6.5) was significantly lower in the vanilla group when compared with control (15±7.3 and 21±13.7 respectively). Odor stimulation with vanilla has an impact on oral feeding in premature infants, however the odor has to be presented on regular basis.

  3. [Study of bacterial flora in the oral cavity and stomach of elderly patients receiving nasogastric tube feeding].

    PubMed

    Matsuura, T; Suzuki, K; Yamakoshi, M; Yamamoto, T; Yamamoto, T; Yoshitomo, K; Tonegawa, K; Ariga, K; Odawara, F

    1997-05-01

    To investigate the significance of oropharyngeal flora and gastric flora in elderly patients receiving nasogastric tube feeding, throat secretions and gastric aspirates were cultured and the pH of the latter was measured. Of 116 bacterial isolates from throat secretions of 27 elderly patients, 30 were beta-streptococci and 28 were Pseudomonas aeruginosa. Bacteria isolated from gastric aspirates numbered 86 and 24 (27.9%) of them were the same species as those found in the throat secretions. Patients with gastric pH were below 3.5 had significantly lower concentrations of gram-negative bacili in gastric aspirates. We also studied oropharyngeal flora in 33 elderly patients who were admitted to Nagoyashi Koseiin Geriatric Hospital. The major bacterial isolates from throat swabs of bedridden patients were gram-negative bacilli and beta-streptococci, especially group B streptococci (GBS). We measured the level of antibody to GBS in these patients. Those from whom GBS were isolated had high titers. These results suggest that in elderly patients receiving enteral nasogastric) tube feeding, large numbers of bacteria colonize the oral cavity and stomach. The measurement of type-specific antibody to GBS may be useful in managing such patients.

  4. Reassessment of the role of enteral tube feedings for patients with esophageal cancer.

    PubMed

    Starr, Brett; Davis, Stephanie; Ayala-Peacock, Diandra; Blackstock, William A; Levine, Edward A

    2014-08-01

    Nutrition is important for patients with esophageal cancer because dysphagia can be exacerbated by chemoradiotherapy. Some centers suggest routine enteral tube placement (TF) to facilitate nutrition. This investigation was to evaluate the use of TF access for patients undergoing multimodality therapy for esophageal carcinoma. This retrospective study analyzed 113 patients who underwent esophagectomy and 97 patients who underwent definition chemoradiotherapy for esophageal cancer between 2001 and 2013. Throughout this time period, a strategy for selective tube placement was used. Nutrition was assessed through absolute lymphocyte counts, protein, and albumin levels. A total of 28 (30%) patients during preoperative chemoradiotherapy and 31 (32%) of those undergoing definitive chemoradiation received TFs. There were 16 Dobhoff tubes, 28 gastrostomy tubes, and 15 jejunostomies. Tubes were maintained an average of 3.9 months with 20 (34%) of these patients reporting tube-related complications. At the time of surgery, there was no statistical difference in any of the nutritional assessments between those patients who received TF and those who did not. Both groups experienced similar total postoperative complication rates (64% vs 65%) and similar median length of hospital stay (12 to 13 days). Chemoradiotherapy resulted in decreased nutritional parameters; however, there was no difference in the degree of reduction between those who underwent TF and those who did not. The data show that routine placement of enteral access is not necessary for esophageal carcinoma. In fact, the risks of placing enteral access may outweigh the benefits. Administration of TF should be restricted to select patients during chemoradiotherapy or before esophagectomy.

  5. Typing and Subtyping of 83 Clinical Isolates Purified from Surgically Implanted Silicone Feeding Tubes by Random Amplified Polymorphic DNA Amplification

    PubMed Central

    Dautle, Melanie P.; Ulrich, Ricky L.; Hughes, Thomas A.

    2002-01-01

    In this study, 83 clinical isolates purified from biofilms colonizing 18 silicone gastrostomy devices (12 “buttons” and six tubes converted to skin level devices) were selected for subtype characterization utilizing genetic analysis. The tubes, previously used for feeding, remained in place for 3 to 47 months (mean, 20.0 months) in children ranging in age from 6 months to 17 years. Classification of specific microbes using random amplified polymorphic DNA (RAPD) analysis revealed genetic similarities and differences among isolates belonging to the same genus. Both gram-positive and -negative bacteria were investigated, including 2 isolates of Bacillus brevis, 4 isolates of Bacillus licheniformis, 2 isolates of Bacillus pumilus, 3 isolates of Enterococcus durans, 19 isolates of Enterococcus faecalis, 8 isolates of Enterococcus faecium, 2 isolates of Enterococcus hirae, 7 isolates of Escherichia coli, 8 isolates of Lactobacillus plantarum, 19 isolates of Staphylococcus aureus, 2 isolates of Staphylococcus epidermidis, and 7 isolates of Staphylococcus saprophyticus. Amplified DNA fragments (amplicons) provided species-specific fingerprints for comparison by agarose gel electrophoresis. A total of 62 distinct RAPD types were categorized from the five genera studied. Typing analysis suggested cross acquisition of E. coli, E. faecalis, and S. aureus in three patient pairs. Genomic polymorphism detection proved efficient and reliable for classifying bacterial subtypes isolated from biofilms adhering to various portions of commonly employed enteral access tubes. PMID:11825951

  6. Abrasion resistant composition

    SciTech Connect

    Fischer, Keith D; Barnes, Christopher A; Henderson, Stephen L

    A surface covering composition of abrasion resistant character adapted for disposition in overlying bonded relation to a metal substrate. The surface covering composition includes metal carbide particles within a metal matrix at a packing factor of not less than about 0.6. Not less than about 40 percent by weight of the metal carbide particles are characterized by an effective diameter in the range of +14-32 mesh prior to introduction to the metal matrix. Not less than about 3 percent by weight of the metal carbide particles are characterized by an effective diameter of +60 mesh prior to introduction to themore » metal matrix.« less

  7. Experience in Bedside Placement, Clinical Validity, and Cost-Efficacy of a Self-Propelled Nasojejunal Feeding Tube

    PubMed Central

    Puiggròs, Carolina; Molinos, Rosa; Ortiz, M. Dolors; Ribas, Montserrat; Romero, Carlos; Vázquez, Concepcion; Segurola, Hegoi; Burgos, Rosa

    2015-01-01

    Background: The procedures needed to insert nasojejunal tubes (NJTs) are often invasive or uncomfortable for the patient and require hospital resources. The objectives of this study were to describe our experience in inserting a self-propelling NJT with distal pigtail end and evaluate clinical validity and cost efficacy of this enteral nutrition (EN) approach compared with parenteral nutrition (PN). Materials and Methods: Prospective study from July 2009 to December 2010, including hospitalized noncritical patients who required short-term jejunal EN. The tubes were inserted at bedside, using intravenous erythromycin as a prokinetic drug. Positioning was considered correct when the distal end was beyond the ligament of Treitz. Migration failure was considered when the tube was not positioned into the jejunum within 48 hours postinsertion. Results: Fifty-six insertions were recorded in 47 patients, most frequently in severe acute pancreatitis (69.6%). The migration rates at 18 and 48 hours postinsertion were 73.2% and 82.1%, respectively. There was migration failure in 8.9% of cases, and 8.9% were classified null (the tube was no longer in the gastrointestinal tract at 18 hours). There were no reported or observed complications. The mean duration of the EN was 12 ± 10.8 days. Five different types of EN formula were used. The total study cost was 53.9% lower compared with using PN in all patients. Conclusions: Our study demonstrated that bedside insertion of a self-propelling NJT is a safe, cost-effective, and successful technique for postpyloric enteral feeding in at least 73% of the patients, and only 18% of patients could eventually need other placement techniques. It can avoid the need for more aggressive or expensive placement techniques or even PN if we cannot achieve enteral access. PMID:26214512

  8. Using sounds for making decisions: greater tube-nosed bats prefer antagonistic calls over non-communicative sounds when feeding

    PubMed Central

    Jiang, Tinglei; Long, Zhenyu; Ran, Xin; Zhao, Xue; Xu, Fei; Qiu, Fuyuan; Kanwal, Jagmeet S.

    2016-01-01

    ABSTRACT Bats vocalize extensively within different social contexts. The type and extent of information conveyed via their vocalizations and their perceptual significance, however, remains controversial and difficult to assess. Greater tube-nosed bats, Murina leucogaster, emit calls consisting of long rectangular broadband noise burst (rBNBl) syllables during aggression between males. To experimentally test the behavioral impact of these sounds for feeding, we deployed an approach and place-preference paradigm. Two food trays were placed on opposite sides and within different acoustic microenvironments, created by sound playback, within a specially constructed tent. Specifically, we tested whether the presence of rBNBl sounds at a food source effectively deters the approach of male bats in comparison to echolocation sounds and white noise. In each case, contrary to our expectation, males preferred to feed at a location where rBNBl sounds were present. We propose that the species-specific rBNBl provides contextual information, not present within non-communicative sounds, to facilitate approach towards a food source. PMID:27815241

  9. BETAINE FEEDING PREVENTS THE BLOOD ALCOHOL CYCLE IN RATS FED ALCOHOL CONTINUOUSLY FOR 1 MONTH USING THE RAT INTRAGASTRIC TUBE FEEDING MODEL

    PubMed Central

    Li, J; Li, XM; Caudill, M; Malysheva, O; Bardag-Gorce, F; Oliva, J; French, BA; Gorce, E; Morgan, K; Kathirvel, E; Morgan, T; French, SW

    2011-01-01

    Background Blood alcohol levels (BAL) cycle up and down over a 7–8 day period when ethanol is fed continuously for one month in the intragastric tube feeding rat model (ITFRM) of alcoholic liver disease. The cycling phenomenon is due to an alternating increase and decrease in the metabolic rate. Recently, we found that S-adenosyl-methionine (SAMe) fed with alcohol prevented the BAL cycle. Method Using the ITFRM we fed rats betaine (2 g/kg/day) with ethanol for 1 month and recorded the daily 24 h urine ethanol level (UAL) to measure the BAL cycle. UAL is equivalent to BAL because of the constant ethanol infusion. Liver histology, steatosis and BAL were measured terminally after 1 month of treatment. Microarray analysis was done on the mRNA extracted from the liver to determine the effects of betaine and alcohol on changes in gene expression. Results Betaine fed with ethanol completely prevented the BAL cycle similar to SAMe. Betaine also significantly reduced the BAL compared to ethanol fed rats without betaine. This was also observed when SAMe was fed with ethanol. The mechanism involved in both cases is that SAMe is required for the conversion of epinephrine from norepinephrine by phenylethanolamine methyltransferase (PNMT). Epinephrine is 5 to 10 fold more potent than norepinephrine in increasing the metabolic rate. The increase in the metabolic rate generates NAD, permitting ADH to increase the oxidation of alcohol. NAD is the rate limiting factor in oxidation of alcohol by alcohol dehydrogenase (ADH). This explains how SAMe and betaine prevented the cycle. Microarray analysis showed that betaine feeding prevented the up regulation of a large number of genes including TLR2/4, Il-1b, Jax3, Sirt3, Fas, Ifngr1, Tgfgr2, Tnfrsf21, Lbp and Stat 3 which could explain how betaine prevented fatty liver. Conclusion Betaine feeding lowers the BAL and prevents the BAL cycle by increasing the metabolic rate. This increases the rate of ethanol elimination by generating NAD

  10. The Effect of an Intervention Aimed at Reducing Errors when Administering Medication through Enteral Feeding Tubes in an Institution for Individuals with Intellectual Disability

    ERIC Educational Resources Information Center

    Idzinga, J. C.; de Jong, A. L.; van den Bemt, P. M. L. A.

    2009-01-01

    Background: Previous studies, both in hospitals and in institutions for clients with an intellectual disability (ID), have shown that medication errors at the administration stage are frequent, especially when medication has to be administered through an enteral feeding tube. In hospitals a specially designed intervention programme has proven to…

  11. Drug Administration via Enteral Feeding Tube in Residential Care Facilities for Individuals with Intellectual Disability: A Focus Group Study on Guideline Implementation

    ERIC Educational Resources Information Center

    Joos, Elke; Van Tongelen, Inge; Wijnants, Karen; Mehuys, Els; Van Bocxlaer, Jan; Remon, Jean Paul; Grypdonck, Maria; Van Winckel, Myriam; Boussery, Koen

    2016-01-01

    People with profound intellectual disabilities often receive medication through enteral feeding tube (EFT). In a previous study, we found that current guidelines concerning medication preparation and administration through EFT are often not followed in residential care facilities (RCFs) for individuals with intellectual disabilities. The present…

  12. Gastrointestinal tolerance and plasma status of carotenoids, EPA and DHA with a fiber-enriched tube feed in hospitalized patients initiated on tube nutrition: Randomized controlled trial.

    PubMed

    Jakobsen, L H; Wirth, R; Smoliner, C; Klebach, M; Hofman, Z; Kondrup, J

    2017-04-01

    During the first days of tube feeding (TF) gastrointestinal (GI) complications are common and administration of sufficient nutrition is a challenge. Not all standard nutritionally complete formulas contain dietary fiber, fish oil or carotenoids, key dietary nutrients for health and wellbeing. The aim of this study was to investigate the effects of a fiber, fish oil and carotenoid enriched TF formula on diarrhea, constipation and nutrient bioavailability. A multi-center randomized, double-blind, controlled, parallel trial compared the effects of a dietary fiber, fish oil and carotenoid-enriched TF formula (test) with an isocaloric non-enriched formula (control) in 51 patients requiring initiation of TF. Incidence of diarrhea and constipation (based on stool frequency and consistency) was recorded daily. Plasma status of EPA, DHA and carotenoids was measured after 7 days. The incidence of diarrhea was lower in patients receiving the test formula compared with the control group (19% vs. 48%, p = 0.034). EPA and DHA status (% of total plasma phospholipids) was higher after 7 days in test compared with control group (EPA: p = 0.002, DHA: p = 0.082). Plasma carotenoid levels were higher after 7 days in the test group compared with control group (lutein: p = 0.024, α-carotene: p = 0.005, lycopene: p = 0.020, β-carotene: p = 0.054). This study suggests that the nutrient-enriched TF formula tested might have a positive effect on GI tolerance with less diarrhea incidence and significantly improved EPA, DHA and carotenoid plasma levels during the initiation of TF in hospitalized patients who are at risk of diarrhea and low nutrient status. This trial was registered at trialregister.nl; registration number 2924. Copyright © 2016. Published by Elsevier Ltd.

  13. Nasogastric feeding tube located in the lung. SENSAR case of the trimester.

    PubMed

    2017-01-01

    A clinical case is presented that was communicated to Spanish Notification System on Safety in Anaesthesia and Recovery (SENSAR). Using this communication and its analysis, a strategy is obtained in order to reduce the risks associated with the insertion of a nasogastric tube (NST) for enteral nutrition in adult patients in the post-surgical recovery unit. A description of the incident is presented, an analysis of its causes, and the measures that were introduced in order to avoid similar incidents in the future, as well as to promote a safety culture in the organisation. A description of associated incidents registered in SENSAR is also given. The aim of this work is to describe, analyse and introduce safety measures arising from incidents notified to SENSAR, associated with the insertion and checking of the nutrition NST in adult patients in the post-surgical recovery unit. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Effect of physician education and patient counseling on inpatient nonsurgical percutaneous feeding tube placement rate, indications, and outcome.

    PubMed

    Swaminath, Arun; Longstreth, George F; Runnman, Eva M; Yang, Su-Jau

    2010-02-01

    The decision to place a percutaneous feeding tube (PFT) in patients who are at the end of life is multidimensional and often complicated. We assessed the effect of physician education and counseling for patients and their surrogates on inpatient nonsurgical (endoscopic and radiologic) PFT placement rates, indications, complications, and mortality. In a pre-paid group practice, a geriatrician initiated a program of physician education and patient/surrogate counseling on the ethical and nutritional aspects of long-term enteral feeding. We compared rates of nonsurgical PFT placement (excluding those for cancer therapy or gastric decompression), indications, complications, and short- and long-term mortality in adult inpatients before (2004) and after (2005) the program. In 2004 and 2005, 115 and 60 inpatients underwent PFT placement, respectively. The annual number of hospital admissions was similar, but the rate of PFT placement declined (0.80% vs. 0.44%, P < 0.0001). The indications were cerebrovascular accident (42 [37%] versus 22 [37%]), dementia (15 [13%] versus 3 [5%]), other neurological disease (28 [24%] versus 16 [26%]), and miscellaneous disease (30 [26%] versus 19 [32%]); P > 0.05. Severe infectious complications occurred in 4 (3%) versus 0 (0%) patients, P > 0.05. Mortality (2004 versus 2005) at 30 days (23 [20%] versus 11 [18%]), 1 year (62 [54%] versus 29 [48%]) and 2 years (72 [63%] versus 31 [52%]) was similar, P > 0.05. A pilot program of educating referring physicians and counseling patients and their surrogates reduced the rate of inpatient PFT placement by nearly 50%. Indications, severe complications and short- and long-term mortality remained unchanged.

  15. A cost-utility analysis in patients receiving enteral tube feeding at home and in nursing homes.

    PubMed

    Elia, Marinos; Stratton, Rebecca J

    2008-06-01

    A cost-utility analysis was undertaken of enteral tube feeding (ETF) in patients with cerebrovascular accident (CVA). Mortality during ETF was established in nursing homes (n7007) or at home (n2888). Quality of life was measured (EuroQol) on a sub-sample (n25). Quality adjusted life years (QALYs) over 3 years and the cost/QALY were calculated. The cost/QALY (1 pound=1.482 euros; 30/06/05) for patients receiving ETF at home was 12,817 pounds (10,351 pounds-16,826 pounds using 95% CI for quality of life) and insensitive to the frequency of home visits (50-150% of the average frequency; 11,851 pounds-13,782 pounds), outcome of patients reverting to full oral feeding (0-100% survival; 11,023 pounds-14,440 pounds), and computed outcome of a 'control' group not given ETF (0.125-0.25 year survival; 12,991 pound-14,006 pounds). The cost/QALY in nursing homes (10,304 pounds-68,064 pounds) varied depending on the state contribution to non-medical costs and is above and below the threshold (30,000 pounds/QALY). The data suggest the cost-effectiveness of ETF in patients with CVA receiving ETF at home or in nursing homes, where the non-medical costs are paid privately, compares favourably with other interventions. The cost-effectiveness of ETF in nursing homes when the state pays all non-medical costs compares unfavourably with other treatments, raising economic, clinical, and ethical concerns.

  16. Conduit Coating Abrasion Testing

    NASA Technical Reports Server (NTRS)

    Sullivan, Mary K.

    2013-01-01

    During my summer internship at NASA I have been working alongside the team members of the RESTORE project. Engineers working on the RESTORE project are creating ·a device that can go into space and service satellites that no longer work due to gas shortage or other technical difficulties. In order to complete the task of refueling the satellite a hose needs to be used and covered with a material that can withstand effects of space. The conduit coating abrasion test will help the researchers figure out what type of thermal coating to use on the hose that will be refueling the satellites. The objective of the project is to determine whether or not the conduit coating will withstand the effects of space. For the RESTORE project I will help with various aspects of the testing that needed to be done in order to determine which type of conduit should be used for refueling the satellite. During my time on the project I will be assisting with wiring a relay board that connected to the test set up by soldering, configuring wires and testing for continuity. Prior to the testing I will work on creating the testing site and help write the procedure for the test. The testing will take place over a span of two weeks and lead to an informative conclusion. Working alongside various RESTORE team members I will assist with the project's documentation and records. All in all, throughout my internship at NASA I hope to learn a number of valuable skills and be a part of a hard working team of engineers.

  17. Effect of two carbohydrate-modified tube-feeding formulas on metabolic responses in patients with type 2 diabetes.

    PubMed

    Voss, Anne Coble; Maki, Kevin C; Garvey, W Timothy; Hustead, Deborah S; Alish, Carolyn; Fix, Brenda; Mustad, Vikkie A

    2008-10-01

    This study evaluated the glycemic, insulinemic, and glucagon-like peptide-1 (GLP-1) responses of subjects with type 2 diabetes mellitus to consumption of two diabetes-specific tube-feeding formulas (slowly digested carbohydrate formula [SDC] and diabetes-specific formula [DSF]) and one formula intended for individuals without diabetes (standard formula [STND]). Forty-eight subjects controlled with diet and/or oral antihyperglycemic medications received the SDC, DSF, and STND. Postprandial glucose, insulin, and GLP-1 were measured on three occasions after an overnight fast in a double-blinded, randomized, three-treatment, crossover design. The positive area under the curve for glucose and insulin with the STND was higher (P < 0.001) compared with the SDC and DSF. The adjusted GLP-1 concentration at 60 min was higher for the SDC compared with the DSF and STND (P < 0.05). Both lower-carbohydrate diabetes-specific formulas resulted in a lower postprandial blood glucose response compared with the STND. The formula also rich in slowly digested carbohydrate and monounsaturated and omega-3 fatty acids (SDC) produced significantly lower blood glucose and insulin responses and higher levels of GLP-1 in the presence of significantly lower insulin concentrations. These results support the view that the quantity and quality of carbohydrate and fat may play important roles in the management of patients with type 2 diabetes mellitus and could result in improved beta-cell function over the long term.

  18. Physics of loose abrasive microgrinding.

    PubMed

    Golini, D; Jacobs, S D

    1991-07-01

    This study examined the physics of loose abrasive microgrinding (grinding with micron and submicron sized abrasives). More specifically, it focused on the transition from brittle to ductile mode grinding which occurs in this region of abrasive sizes. Process dependency on slurry chemistry was the primary area of emphasis and was studied for diamond abrasives varying in size from 3.0 to 0.75 microm on both ULE and Zerodur, with emphasis on ULE. Ductile mode grinding was achieved with smaller abrasives, as expected, however two significant discoveries were made. The first observation was that by simply changing slurry chemistry, it was possible to induce the transition from brittle fracture to ductile mode grinding in ULE. This transition point could be intentionally moved about for diamonds 3.0-0.75 microm in diameter. For any given abrasive size within these limits, either brittle fracture or ductile removal may be achieved, depending on the slurry used to suspend the diamonds. Several slurries were studied, including water, a series of homologous n-alcohols, and other solvents chosen for properties varying from molecular size to dielectric constant and zeta potential. The study revealed that this slurry dependency is primarily a Rebinder effect. The second finding was that a tremendous amount of surface stress is introduced in loose abrasive ductile mode grinding. This stress was observed when the Twyman Effect in ULE plates increased by a factor of 4 in the transition from the brittle to the ductile mode. An assessment of the cause of this stress is discussed.

  19. The effect of an intervention aimed at reducing errors when administering medication through enteral feeding tubes in an institution for individuals with intellectual disability.

    PubMed

    Idzinga, J C; de Jong, A L; van den Bemt, P M L A

    2009-11-01

    Previous studies, both in hospitals and in institutions for clients with an intellectual disability (ID), have shown that medication errors at the administration stage are frequent, especially when medication has to be administered through an enteral feeding tube. In hospitals a specially designed intervention programme has proven to be effective in reducing these feeding tube-related medication errors, but the effect of such a programme within an institution for clients with an ID is unknown. Therefore, a study was designed to measure the influence of such an intervention programme on the number of medication administration errors in clients with an ID who also have enteral feeding tubes. A before-after study design with disguised observation to document administration errors was used. The study was conducted from February to June 2008 within an institution for individuals with an ID in the Western part of The Netherlands. Included were clients with enteral feeding tubes. The intervention consisted of advice on medication administration through enteral feeding tubes by the pharmacist, a training programme and introduction of a 'medication through tube' box containing proper materials for crushing and suspending tablets. The outcome measure was the frequency of medication administration errors, comparing the pre-intervention period with the post-intervention period. A total of 245 medication administrations in six clients (by 23 nurse attendants) have been observed in the pre-intervention measurement period and 229 medication administrations in five clients (by 20 nurse attendants) have been observed in the post-intervention period. Before the intervention, 158 (64.5%) medication administration errors were observed, and after the intervention, this decreased to 69 (30.1%). Of all potential confounders and effect modifiers, only 'medication dispensed in automated dispensing system ("robot") packaging' contributed to the multivariate model; effect modification was

  20. Casing window milling with abrasive fluid jet

    SciTech Connect

    Vestavik, O.M.; Fidtje, T.H.; Faure, A.M.

    1995-12-31

    Methods for through tubing re-entry drilling of multilateral wells has a large potential for increasing hydrocarbon production and total recovery. One of the bottle-necks of this technology is initiation of the side-track by milling a window in the casing downhole. A new approach to this problem has been investigated in a joint industry project. An experimental set-up has been built for milling a 4 inch window in a 7 inch steel casing at surface in the laboratory. A specially designed bit developed at RIF using abrasive jet cutting technology has been used for the window milling. The bit has anmore » abrasive jet beam which is always directed in the desired side-track direction, even if the bit is rotating uniformly. The bit performs the milling with a combined mechanical and hydraulic jet action. The method has been successfully demonstrated. The experiments has shown that the window milling can be performed with very low WOB and torque, and that only small side forces are required to perform the operation. Casing milling has been performed without a whipstock, a cement plug has been the only support for the tool. The tests indicate that milling operations can be performed more efficiently with less time and costs than what is required with conventional techniques. However, the method still needs some development of the downhole motor for coiled tubing applications. The method can be used both for milling and drilling giving the advantage of improved rate of penetration, improved bit life and increased horizontal reach. The method is planned to be demonstrated downhole in the near future.« less

  1. Swallowing performance and tube feeding status in patients treated with parotid-sparing intensity-modulated radiotherapy for head and neck cancer.

    PubMed

    Roe, Justin W G; Carding, Paul N; Drinnan, Michael J; Harrington, Kevin J; Nutting, Christopher M

    2016-04-01

    The purpose of this prospective study was to evaluate the swallowing performance of patients with head and neck cancer treated with parotid-sparing intensity-modulated radiotherapy (IMRT). Sixty-two patients were recruited. Data were collected before and up to 12 months after treatment. Measures included the Performance Status Scale for head and neck cancer (PSS-HN Normalcy of Diet and Eating in Public subscales), tube feeding status, and 100 mL water swallow test (WST) volume and capacity scores. There was a significant reduction in PSS-HN and WST scores from baseline to 3 months (p < .001). Significant improvements were observed up to 12 months on the PSS-HN. Swallowing volume and capacity scores recovered but did not reach statistical significance. Tube feeding was not required in 47% of the patients. IMRT significantly impacts on swallowing performance, although there is a trend for improvement up to 12 months after treatment. Our data support a case-by-case approach to tube feeding. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1436-E1444, 2016. © 2015 Wiley Periodicals, Inc.

  2. Carnitine deficiency presenting with a decreased mental state in a patient with amyotrophic lateral sclerosis receiving long-term tube feeding: a case report.

    PubMed

    Isse, Naohi; Miura, Yoh; Obata, Toshiyuki; Takahara, Noriko

    2013-12-30

    L-carnitine is an important metabolic mediator involved in fatty acid transport. It is obtained from the diet, particularly from animal products, such as red meat. Previous reports have revealed that long-term tube feeding with a commercial product containing no or low levels of carnitine can lead to an altered mental state caused by hyperammonemia. A 72-year-old Japanese man had a 12-year history of amyotrophic lateral sclerosis. He was bedridden and had required mechanical ventilation and enteral tube feeding for 10 years at home. His main enteral solution was a commercial product that contained low carnitine levels, and he sometimes received coffee and homemade products such as miso soup. Our patient's ability to communicate gradually deteriorated over a period of one year. His serum total carnitine level was abnormally low, at 26.7μmol/L (normal range, 45 to 91μmol/L), but his ammonium level was normal. His mental state improved dramatically after starting L-carnitine supplementation (600mg twice daily). This case highlights the importance of avoiding carnitine deficiency in patients with amyotrophic lateral sclerosis undergoing long-term tube feeding. These patients experience progressive muscle atrophy that might cause impaired carnitine storage and might manifest as communication difficulties. Carnitine deficiency can be misdiagnosed as a progression of systemic muscle atrophy. Clinicians should be aware of this disorder and should consider periodically measuring carnitine levels, regardless of the patient's serum ammonium levels.

  3. Implementation of an electromagnetic imaging system to facilitate nasogastric and post-pyloric feeding tube placement in patients with and without critical illness.

    PubMed

    Windle, E M; Beddow, D; Hall, E; Wright, J; Sundar, N

    2010-02-01

    Artificial nutrition support is required to optimise nutritional status in many patients. Traditional methods of placing feeding tubes may incur clinical risk and financial costs. A technique facilitating placement of nasogastric and post-pyloric tubes via electromagnetic visual guidance may reduce the need for X-ray exposure, endoscopy time and the use of parenteral nutrition. The present study aimed to audit use of such a system at initial implementation in patients within an acute NHS Trust. A retrospective review was undertaken of dietetic and medical records for the first 14 months of using the Cortrak system. Data were collected on referral origin, preparation of the patient prior to insertion, placement success rates and need for X-ray. Cost analysis was also performed. Referrals were received from primary consultants or consultant intensivists, often on the advice of the dietitian. Fifty-nine percent of patients received prokinetic therapy at the time of placement. Thirty-nine tube placements were attempted. Sixty-nine percent of referrals for post-pyloric tube placement resulted in successful placement. X-ray films were requested for 22% of all attempted post-pyloric placements. Less than half of nasogastric tubes were successfully passed, although none of these required X-ray confirmation. The mean cost per tube insertion attempt was 111 pounds. This system confers advantages, particularly in terms of post-pyloric tube placement, even at this early stage of implementation. A reduction in clinical risk and cost avoidance related to X-ray exposure, the need for endoscopic tube placement and parenteral nutrition have been achieved. The implementation of this system should be considered in other centres.

  4. Pleurectomy versus pleural abrasion for primary spontaneous pneumothorax in children.

    PubMed

    Joharifard, Shahrzad; Coakley, Brian A; Butterworth, Sonia A

    2017-05-01

    Primary spontaneous pneumothorax (PSP) represents a common indication for urgent surgical intervention in children. First episodes are often managed with thoracostomy tube, whereas recurrent episodes typically prompt surgery involving apical bleb resection and pleurodesis, either via pleurectomy or pleural abrasion. The purpose of this study was to assess whether pleurectomy or pleural abrasion was associated with lower postoperative recurrence. The records of patients undergoing surgery for PSP between February 2005 and December 2015 were retrospectively reviewed. Recurrence was defined as an ipsilateral pneumothorax requiring surgical intervention. Bivariate logistic regressions were used to identify factors associated with recurrence. Fifty-two patients underwent 64 index operations for PSP (12 patients had surgery for contralateral pneumothorax, and each instance was analyzed separately). The mean age was 15.7±1.2years, and 79.7% (n=51) of patients were male. In addition to apical wedge resection, 53.1% (n=34) of patients underwent pleurectomy, 39.1% (n=25) underwent pleural abrasion, and 7.8% (n=5) had no pleural treatment. The overall recurrence rate was 23.4% (n=15). Recurrence was significantly lower in patients who underwent pleurectomy rather than pleural abrasion (8.8% vs. 40%, p<0.01). In patients who underwent pleural abrasion without pleurectomy, the relative risk of recurrence was 2.36 [1.41-3.92, p<0.01]. Recurrence of PSP is significantly reduced in patients undergoing pleurectomy compared to pleural abrasion. Level III, retrospective comparative therapeutic study. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Feeding tube insertion - gastrostomy

    MedlinePlus

    ... and the A.D.A.M. Editorial team. Nutritional Support Read more NIH MedlinePlus Magazine Read more ... any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should ...

  6. Tube Feeding Troubleshooting Guide

    MedlinePlus

    ... in place. (For example, does it have a balloon, a mushroom bumper, or other internal device, or ... Frequent vomiting. • See “Nausea and Vomiting” page 3. Balloon deflates or bursts. • Be sure the balloon under ...

  7. Nasogastric feeding tube

    MedlinePlus

    ... chap 16. Ziegler TR. Malnutrition, nutritional assessment, and nutritional support in adult hospitalized patients. In: Goldman L, Schafer ... A.M. Editorial team. Related MedlinePlus Health Topics Nutritional Support Browse the Encyclopedia A.D.A.M., Inc. ...

  8. Feeding tube - infants

    MedlinePlus

    ... BP, Ehrenkranz RA. Nutrient requirements and provision of nutritional support in the premature neonate. In: Martin RJ, Fanaroff ... and the A.D.A.M. Editorial team. Nutritional Support Read more NIH MedlinePlus Magazine Read more Health ...

  9. Jejunostomy feeding tube

    MedlinePlus

    ... in adult hospitalized patients. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 217. Read More Cerebral palsy Cystic fibrosis Esophageal cancer Failure to thrive HIV/AIDS Patient Instructions Crohn ...

  10. Gastrostomy Tube Feeding in Children With Developmental or Acquired Disorders: A Longitudinal Comparison on Healthcare Provision and Eating Outcomes 4 Years After Gastrostomy.

    PubMed

    Backman, Ellen; Karlsson, Ann-Kristin; Sjögreen, Lotta

    2018-03-30

    Studies on long-term feeding and eating outcomes in children requiring gastrostomy tube feeding (GT) are scarce. The aim of this study was to describe children with developmental or acquired disorders receiving GT and to compare longitudinal eating and feeding outcomes. A secondary aim was to explore healthcare provision related to eating and feeding. This retrospective cohort study reviewed medical records of children in 1 administrative region of Sweden with GT placement between 2005 and 2012. Patient demographics, primary diagnoses, age at GT placement, and professional healthcare contacts prior to and after GT placement were recorded and compared. Feeding and eating outcomes were assessed 4 years after GT placement. The medical records of 51 children, 28 boys and 23 girls, were analyzed and grouped according to "acquired" (n = 13) or "developmental" (n = 38) primary diagnoses. At 4 years after GT placement, 67% were still using GT. Only 6 of 37 (16%) children with developmental disorders transferred to eating all orally, as opposed to 10 of 11 (91%) children with acquired disorders. Children with developmental disorders were younger at the time of GT placement and displayed a longer duration of GT activity when compared with children with acquired disorders. This study demonstrates a clear difference between children with developmental or acquired disorders in duration of GT activity and age at GT placement. The study further shows that healthcare provided to children with GT is in some cases multidisciplinary, but primarily focuses on feeding rather than eating. © 2018 American Society for Parenteral and Enteral Nutrition.

  11. Research on operation mode of abrasive grain during grinding

    NASA Astrophysics Data System (ADS)

    Ivanova, T. N.; Dement’ev, V. B.; Nikitina, O. V.

    2018-03-01

    The processing of materials by cutting with an abrasive tool is carried out by means of thousands of grains bonded together as a single whole. The quality of the abrasive tool is defined by cutting properties of abrasive grains and depends on features of spreading the temperature field in time and in the abrasive grain volume. Grains are exposed to heating and cooling during work. It leads to undesired effects such as a decrease of durability of grain retention in the binder, hardness, intensification of diffusion and oxidation processes between the binder and the grain, the occurrence of considerable temperature stresses in the grain itself. The obtained equation which allows calculation of temperature field of grain for one rotation of grinding wheel shows that the temperature of the wheel depends on grinding modes and thermophysical properties of abrasive material. Thus, as the time of contact of grain with processed material increases, the temperature in the cutting area rises. As thermophysical properties increase, the temperature in cutting area decreases. Thermal working conditions are determined to be different from each other depending on contact time of the grain and the material. For example, in case of creep-feed grinding, the peak value of temperature is higher than during multistep grinding; the depth of expansion is greater. While the speed of the thermal process in creep-feed grinding is 2-3 times lower than in multistep grinding, the gradient reduces 3-4 times. The analysis of machining methods shows that creep-feed grinding ensures greater depth of grain heating, a smaller heating rate and a reduced velocity gradient. It causes a decrease of probable allotropic modifications and prevents from occurring of heat strokes - cracking of grains due to high temperature falls. Consequently, it is necessary to employ creep-feed grinding to increase the efficiency of abrasive tool employing. Three operation modes of grinding wheel including blunting, full

  12. Development of underwater cutting system by abrasive water-jet

    NASA Astrophysics Data System (ADS)

    Demura, Kenji; Yamaguchi, Hitoshi

    1993-09-01

    The technology to cut objects in the ocean's depths with abrasive water jets was examined for possible application in view of the greater water depths and sophistication involved in work on the ocean floor today. A test model was developed to study this technology's safety and practicability. The test model was designed for use at great water depths and has functions and a configuration that are unlike equipment used on land. A continuous, stable supply of abrasive is a distinctive design feature. In land applications, there had been problems with plugged tubes and an uneven supply. For this reason, the abrasive was converted to slurry form, and a continuous pressurized tube pump system was adopted for supply to the nozzle head. Also, a hydraulic motor that does not employ oil or electric power was used to provide an underwater drive that is environment-friendly. The report outlines the technology's general design concept including its distinctive functions and its configuration for use at great depths, and the report provides great detail on the equipment.

  13. Abrasion of acrylic veneers by simulated toothbrushing.

    PubMed

    Xu, H C; Söremark, R; Wiktorsson, G; Wang, T; Liu, W Y

    1984-12-01

    The abrasion responses were tested on four acrylic veneer materials, K + B Plus, K + B 75, Isosit, and Ivocron. The studies were performed in two independent research laboratories. Two different brushing machines were used with an abrasive slurry. The results were used for comparing the degree of abrasion for the resin materials. Three analytical methods of measuring the degree of abrasive wear were used: surface profile measurement, microscopic evaluation, and measurement of loss of volume. Isosit showed the best abrasion resistance of the four materials tested.

  14. Nutritional status and feeding-tube placement in patients with locally advanced hypopharyngeal cancer included in an induction chemotherapy-based larynx preservation program.

    PubMed

    Bozec, Alexandre; Benezery, Karen; Chamorey, Emmanuel; Ettaiche, Marc; Vandersteen, Clair; Dassonville, Olivier; Poissonnet, Gilles; Riss, Jean-Christophe; Hannoun-Lévi, Jean-Michel; Chand, Marie-Eve; Leysalle, Axel; Saada, Esma; Sudaka, Anne; Haudebourg, Juliette; Hebert, Christophe; Falewee, Marie-Noelle; Demard, François; Santini, José; Peyrade, Frédéric

    2016-09-01

    The objective of the study is to evaluate the nutritional status and determine its impact on clinical outcomes in patients with locally advanced hypopharyngeal cancer included in an induction chemotherapy (ICT)-based larynx preservation program without prophylactic feeding-tube placement. All patients with locally advanced (T3/4, N0-3, M0) hypopharyngeal squamous cell carcinoma, technically suitable for total pharyngolaryngectomy, treated by docetaxel, cisplatin and 5-fluorouracil (TPF)-ICT for larynx preservation at our institution between 2004 and 2013, were included in this retrospective study. Patients' nutritional status was closely monitored. Enteral nutrition was used if and when a patient was unable to sustain per-oral nutrition and hydration. The impact of nutritional status on clinical outcomes was investigated in univariate and multivariate analysis. A total of 53 patients (42 men and 11 women, mean age = 58.6 ± 8.2 years) were included in this study. Six (11.3 %) patients had lost more than 10 % of their usual body weight before therapy. Compared with patients' usual weight, the mean maximum patient weight loss during therapeutic management was 8.7 ± 4.5 kg. Enteral nutrition was required in 17 patients (32 %). We found no influence of the tested nutritional status-related factors on response to ICT, toxicity of ICT, overall, cause-specific and recurrence-free survival, and on post-therapeutic swallowing outcome. Maximum weight loss was significantly associated with a higher risk of enteral tube feeding during therapy (p = 0.03) and of complications (grade ≥3, p = 0.006) during RT. Without prophylactic feeding-tube placement, approximately one-third of the patients required enteral nutrition. There was no significant impact of nutritional status on oncologic or functional outcomes.

  15. Early diagnosis and multidisciplinary care reduce the hospitalization time and duration of tube feeding and prevent early obesity in PWS infants.

    PubMed

    Bacheré, N; Diene, G; Delagnes, V; Molinas, C; Moulin, P; Tauber, M

    2008-01-01

    To describe and evaluate the impact of very early diagnosis and multidisciplinary care on the evolution and care of infants presenting with Prader-Willi syndrome (PWS). 19 infants diagnosed with PWS before the second month of life were followed by a multidisciplinary team. Median age at the time of analysis was 3.1 years [range 0.4-6.5]. The data were compared with data collected in 1997 from 113 questionnaires filled out by members of the French PWS Association. The patients from this latter data set were 12.0 years [range 4 months to 41 years] at the time of analysis, with a median age of 36 months at diagnosis. The duration of their hospitalization time was significantly reduced from 30.0 [range 0-670] to 21 [range 0-90] days (p = 0.043). The duration of gastric tube feeding was significantly reduced from 30.5 [range 0-427] to 15 [range 0-60] days (p = 0.017). Growth hormone treatment was started at a mean age of 1.9 +/- 0.5 years in 10 infants and L-thyroxine in 6 infants. Only 1 infant became obese at 2.5 years. Early diagnosis combined with multidisciplinary care decreases the hospitalization time, duration of gastric tube feeding and prevents early obesity in PWS infants. (c) 2007 S. Karger AG, Basel.

  16. Real-time image-guided nasogastric feeding tube placement: A case series using Kangaroo with IRIS Technology in an ICU.

    PubMed

    Mizzi, Anna; Cozzi, Silvano; Beretta, Luigi; Greco, Massimiliano; Braga, Marco

    2017-05-01

    Pulmonary misplacement during the blind insertion of enteral feeding tubes is frequent, particularly in ventilated and neurologically impaired patients. This is probably the first clinical study using the Kangaroo Feeding Tube with IRIS technology (IRIS) which incorporates a camera designed to provide anatomic landmark visualization during insertion. The study aim was to evaluate IRIS performance during bedside gastric placement. This is the first prospective study to collect data on the use of IRIS. Twenty consecutive unconscious patients requiring enteral nutrition were recruited at a single center. IRIS placement was considered complete when a clear image of the gastric mucosa appeared. Correct placement was confirmed using a contrast-enhanced abdominal X-ray. To evaluate the device performance over time, the camera was activated every other day up to 17 d postplacement. In 7 (35%) patients, the trachea was initially visualized, requiring a second placement attempt with the same tube. The IRIS camera allowed recognition of the gastric mucosa in 18 (90%) patients. The esophagogastric junction was identified in one patient, while in a second patient the quality of visualization was poor. Contrast-enhanced X-ray confirmed the gastric placement of IRIS in all patients. IRIS allowed identification of gastric mucosa in 14 (70%) patients 3 d after placement. Performance progressively declined with time (P = 0.006, chi-square for trend). IRIS placement could have spared X-ray confirmation in almost all patients and prevented misplacement into the airway in about one third. Visualization quality needs to be improved, particularly after the first week. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Ceramic-bonded abrasive grinding tools

    DOEpatents

    Holcombe, C.E. Jr.; Gorin, A.H.; Seals, R.D.

    1994-11-22

    Abrasive grains such as boron carbide, silicon carbide, alumina, diamond, cubic boron nitride, and mullite are combined with a cement primarily comprised of zinc oxide and a reactive liquid setting agent and solidified into abrasive grinding tools. Such grinding tools are particularly suitable for grinding and polishing stone, such as marble and granite.

  18. Ceramic-bonded abrasive grinding tools

    DOEpatents

    Holcombe, Jr., Cressie E.; Gorin, Andrew H.; Seals, Roland D.

    1994-01-01

    Abrasive grains such as boron carbide, silicon carbide, alumina, diamond, cubic boron nitride, and mullite are combined with a cement primarily comprised of zinc oxide and a reactive liquid setting agent and solidified into abrasive grinding tools. Such grinding tools are particularly suitable for grinding and polishing stone, such as marble and granite.

  19. Ultrasonic Abrasive Removal Of EDM Recast

    NASA Technical Reports Server (NTRS)

    Mandel, Johnny L.; Jacobson, Marlowe S.

    1990-01-01

    Ultrasonic abrasive process removes layer of recast material generated during electrical-discharge machining (EDM) of damper pocket on turbine blade. Form-fitted tool vibrated ultrasonically in damper pocket from which material removed. Vibrations activate abrasive in pocket. Amount of material removed controlled precisely.

  20. Development of a two-body wet abrasion test method with attention to the effects of reused abradant

    SciTech Connect

    Blau, Peter Julian; Dehoff, Ryan R

    2012-01-01

    Abrasive wear is among the most common and costliest causes for material wastage, and it occurs in many forms. A simple method has been developed to quantify the response of metals and alloys to two-body wet abrasion. A metallographic polishing machine was modified to create a disk-on-flat sliding test rig. Adhesive-backed SiC grinding papers were used under fixed load and speed to rank the abrasive wear of seven alloy steels, some of which are candidates for drill cones for geothermal drilling. Standardized two-body abrasion tests, like those described in ASTM G132, feed unused abrasive into the contact; however, the currentmore » work investigated whether useful rankings could still be obtained with a simpler testing configuration in which specimens repeatedly slide on the same wear path under water-lubricated conditions. Tests using abrasive grit sizes of 120 and 180 resulted in the same relative ranking of the alloys although the coarser grit produced more total wear. Wear decreased when the same abrasive disk was re-used for up to five runs, but the relative rankings of the steels remained the same. This procedure was presented to ASTM Committee G2 on Wear and Erosion as a potential standard test for wet two-body abrasive wear.« less

  1. Construction of a model predicting the risk of tube feeding intolerance after gastrectomy for gastric cancer based on 225 cases from a single Chinese center

    PubMed Central

    Xiaoyong, Wu; Xuzhao, Li; Deliang, Yu; Pengfei, Yu; Zhenning, Hang; Bin, Bai; zhengyan, Li; Fangning, Pang; Shiqi, Wang; Qingchuan, Zhao

    2017-01-01

    Identifying patients at high risk of tube feeding intolerance (TFI) after gastric cancer surgery may prevent the occurrence of TFI; however, a predictive model is lacking. We therefore analyzed the incidence of TFI and its associated risk factors after gastric cancer surgery in 225 gastric cancer patients divided into without-TFI (n = 114) and with-TFI (n = 111) groups. A total of 49.3% of patients experienced TFI after gastric cancer. Multivariate analysis identified a history of functional constipation (FC), a preoperative American Society of Anesthesiologists (ASA) score of III, a high pain score at 6-hour postoperation, and a high white blood cell (WBC) count on the first day after surgery as independent risk factors for TFI. The area under the curve (AUC) was 0.756, with an optimal cut-off value of 0.5410. In order to identify patients at high risk of TFI after gastric cancer surgery, we constructed a predictive nomogram model based on the selected independent risk factors to indicate the probability of developing TFI. Use of our predictive nomogram model in screening, if a probability > 0.5410, indicated a high-risk patients would with a 70.1% likelihood of developing TFI. These high-risk individuals should take measures to prevent TFI before feeding with enteral nutrition. PMID:29245951

  2. Mortality after nasogastric tube feeding initiation in long-term care elderly with oropharyngeal dysphagia--the contribution of refeeding syndrome.

    PubMed

    Lubart, Emilia; Leibovitz, Arthur; Dror, Yosef; Katz, Elena; Segal, Refael

    2009-01-01

    The refeeding syndrome (RS) is an underappreciated but clinically important entity characterized by acute electrolyte abnormalities, mainly hypophosphatemia, fluid retention and dysfunction of various organs and systems, which can result in significant morbidity and occasionally death. To examine the incidence of death cases and death causes following nasogastric tube (NGT) feeding initiation in frail elderly with particular reference to RS. Forty patients with feeding problems for at least 72 h before restarting of alimentation by NGT were included. Excluded were those in any critical clinical situation. Clinical parameters and nutritional assessment were recorded before and after refeeding. Blood samples were taken before, daily for the first 3 days and 1 week after refeeding initiation. During the 1st week of refeeding, 9 patients (22.5%) died and within 1 month 10 more, summing to 47.5%. Most deaths were due to infectious causes [15 out of 19, (79%)]; some were due to no obvious reason [4 out of 19, (21%)]. Significant electrolyte changes were observed in the 2-3 days following refeeding. Significant were the decreases in phosphorus and elevations in potassium and lymphocytes (day 7). We found no correlations between the severity of decreases in levels of phosphorus and mortality. Mortality after NGT feeding initiation was high, mainly due to infectious complications. However, in a considerable number of patients hypophosphatemia was noted, suggesting that RS could be a contributory factor of mortality. Since this is a treatable condition, more attention should be paid to detecting and coping with this problem. Copyright 2009 S. Karger AG, Basel.

  3. Comparison between early enteral feeding with a transnasal tube and parenteral nutrition after total gastrectomy for gastric cancer.

    PubMed

    Nomura, Eiji; Lee, Sang-Woong; Kawai, Masaru; Hara, Hitoshi; Nabeshima, Kazuhito; Nakamura, Kenji; Uchiyama, Kazuhisa

    2015-01-01

    This retrospective study evaluated 21 patients with early enteral feeding (EEF group) and 22 patients without early enteral feeding (non-EEF group) who underwent open total gastrectomy followed by Roux en Y reconstruction and were RO resectable cases. METHDOLOGY: Postoperative complications and course, postoperative/preoperative body weight, whole meal intake, and nutritional, inflammatory, and immunological parameters were recorded and evaluated in both groups. Postoperative meal intake was significantly higher and the first day of defecation was significantly earlier in the EEF group than in the non-EEF group. There were no significant differences between the 2 groups in the blood laboratory data and the rate of complications. In patients with complications, lymphocyte counts and postoperative body weights were compared as indicators of immunostimulation. The lymphocyte counts 7 days after operation and postoperative/preoperative body weight were significantly higher in the EEF group than in the non-EEF group. Although immunostimulation-like findings were observed in the patients with complications after surgery in the present study, the significance of EEF was not clarified because of the lack of cases whose conditions were severe. EEF should be used especially for patients in whom severe disease is possible and avoidance of TPN is desirable.

  4. Population-based comparison of two feeding tube approaches for head and neck cancer patients receiving concurrent systemic-radiation therapy: is a prophylactic feeding tube approach harmful or helpful?

    PubMed

    Olson, Robert; Karam, Irene; Wilson, Gavin; Bowman, Angela; Lee, Christopher; Wong, Frances

    2013-12-01

    The purpose of this study is to compare patient outcomes between a therapeutic versus a prophylactic gastrostomy tube (GT) placement approach in patients treated with concurrent systemic and radiation (SRT) therapy for head and neck cancer (HNC). Outcomes were compared between all HNC patients treated with concurrent SRT from January 2001 to June 2009 from a center that only places GTs therapeutically when clinically necessary (center A) versus a center that generally places them prophylactically (center B). A total of 445 patients with HNC were identified, with 63 % from center A. As anticipated, GTs were placed less commonly in center A compared to B (31 versus 88 %; p < 0.001). Center B had a significantly higher number of GT complications (p < 0.001), including infection (16 versus 5 %), leakage (10 versus 2 %), and blockage (3 versus 1 %). Conversely, center A had a higher admission rate (27 versus 13 %, p = 0.001), most prominent for GT-related issues (15 versus 6 %). Center B had higher GT dependence at 90 days post-radiation therapy (34 versus 12 %; p < 0.001), but not at 1 year (11 versus 10 %; p = 0.74). There was no significant difference in the proportion of head and neck patients who had a 10 % weight loss at 1 year (compared to baseline) between centers A and B (42 versus 53 %, p = 0.07). There was no significant difference in the overall survival (A versus B, HR = 0.99; p = 0.96). A prophylactic GT approach results in exposing higher number of patients to GT complications. The higher rate of hospitalizations using a therapeutic approach suggests that patients are sicker when GTs are required. Given the similar weight loss and survival, a therapeutic approach at an earlier stage of need may be a preferable approach, when access to prompt GT placement is available.

  5. Abrasion by aeolian particles: Earth and Mars

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Marshall, J. R.; White, B. R.; Pollack, J. B.; Marshall, J.; Krinsley, D.

    1984-01-01

    Estimation of the rate of aeolian abrasion of rocks on Mars requires knowledge of: (1) particle flux, (2) susceptibilities to abrasion of various rocks, and (3) wind frequencies on Mars. Fluxes and susceptibilities for a wide range of conditions were obtained in the laboratory and combined with wind data from the Viking meteorology experiment. Assuming an abundant supply of sand-sized particles, estimated rates range up to 2.1 x 10 to the minus 2 power cm of abrasion per year in the vicinity of Viking Lander 1. This rate is orders of magnitude too great to be in agreement with the inferred age of the surface based on models of impact crater flux. The discrepancy in the estimated rate of abrasion and the presumed old age of the surface cannot be explained easily by changes in climate or exhumation of ancient surfaces. The primary reason is thought to be related to the agents of abrasion. At least some sand-sized (approx. 100 micrometers) grains appear to be present, as inferred from both lander and orbiter observations. High rates of abrasion occur for all experimental cases involving sands of quartz, basalt, or ash. However, previous studies have shown that sand is quickly comminuted to silt- and clay-sized grains in the martian aeolian regime. Experiments also show that these fine grains are electrostatically charged and bond together as sand-sized aggregates. Laboratory simulations of wind abrasion involving aggregates show that at impact velocities capable of destroying sand, aggregates from a protective veneer on the target surface and can give rise to extremely low abrasion rates.

  6. [The application of air abrasion in dentistry].

    PubMed

    Mandinić, Zoran; Vulićević, Zoran R; Beloica, Milos; Radović, Ivana; Mandić, Jelena; Carević, Momir; Tekić, Jasmina

    2014-01-01

    One of the main objectives of contemporary dentistry is to preserve healthy tooth structure by applying techniques of noninvasive treatment. Air abrasion is a minimally invasive nonmechanical technique of tooth preparation that uses kinetic energy to remove carious tooth structure. A powerful narrow stream of moving aluminum-oxide particles hit the tooth surface and they abrade it without heat, vibration or noise. Variables that affect speed of cutting include air pressure, particle size, powder flow, tip's size, angle and distance from the tooth. It has been proposed that air abrasion can be used to diagnose early occlusal-surface lesions and treat them with minimal tooth preparation using magnifier. Reported advantages of air abrasion include reduced noise, vibration and sensitivity. Air abrasion cavity preparations have more rounded internal contours than those prepared with straight burs. This may increase the longevity of placed restorations because it reduces the incidence of fractures and a consequence of decreased internal stresses. However, air abrasion cannot be used for all patients, i.e. in cases involving severe dust allergy, asthma, chronic obstructive lung disease, recent extraction or other oral surgery, open wounds, advanced periodontal disease, recent placement of orthodontic appliances and oral abrasions, or subgingival caries removal. Many of these conditions increase the risk of air embolism in the oral soft tissues. Dust control is a challenge, and it necessitates the use of rubber dam, high-volume evacuation, protective masks and safety eyewear for both the patient and the therapist.

  7. Release of carbon nanotubes from an epoxy-based nanocomposite during an abrasion process.

    PubMed

    Schlagenhauf, Lukas; Chu, Bryan T T; Buha, Jelena; Nüesch, Frank; Wang, Jing

    2012-07-03

    The abrasion behavior of an epoxy/carbon nanotube (CNT) nanocomposite was investigated. An experimental setup has been established to perform abrasion, particle measurement, and collection all in one. The abraded particles were characterized by particle size distribution and by electron microscopy. The abrasion process was carried out with a Taber Abraser, and the released particles were collected by a tube for further investigation. The particle size distributions were measured with a scanning mobility particle sizer (SMPS) and an aerodynamic particle sizer (APS) and revealed four size modes for all measured samples. The mode corresponding to the smallest particle sizes of 300-400 nm was measured with the SMPS and showed a trend of increasing size with increasing nanofiller content. The three measured modes with particle sizes from 0.6 to 2.5 μm, measured with the APS, were similar for all samples. The measured particle concentrations were between 8000 and 20,000 particles/cm(3) for measurements with the SMPS and between 1000 and 3000 particles/cm(3) for measurements with the APS. Imaging by transmission electron microscopy (TEM) revealed that free-standing individual CNTs and agglomerates were emitted during abrasion.

  8. Duodenal and ileal glucose infusions differentially alter gastrointestinal peptides, appetite response, and food intake: a tube feeding study.

    PubMed

    Poppitt, Sally D; Shin, Hyun Sang; McGill, Anne-Thea; Budgett, Stephanie C; Lo, Kim; Pahl, Malcolm; Duxfield, Janice; Lane, Mark; Ingram, John R

    2017-09-01

    Background: Activation of the ileal brake through the delivery of nutrients into the distal small intestine to promote satiety and suppress food intake provides a new target for weight loss. Evidence is limited, with support from naso-ileal lipid infusion studies. Objective: The objective of the study was to investigate whether glucose infused into the duodenum and ileum differentially alters appetite response, food intake, and secretion of satiety-related gastrointestinal peptides. Design: Fourteen healthy male participants were randomly assigned to a blinded 4-treatment crossover, with each treatment of single-day duration. On the day before the intervention (day 0), a 380-cm multilumen tube (1.75-mm diameter) with independent port access to the duodenum and ileum was inserted, and position was confirmed by X-ray. Subsequently (days 1-4), a standardized breakfast meal was followed midmorning by a 90-min infusion of isotonic glucose (15 g, 235 kJ) or saline to the duodenum or ileum. Appetite ratings were assessed with the use of visual analog scales (VASs), blood samples collected, and ad libitum energy intake (EI) measured at lunch, afternoon snack, and dinner. Results: Thirteen participants completed the 4 infusion days. There was a significant effect of nutrient infused and site (treatment × time, P < 0.05) such that glucose-to-ileum altered VAS-rated fullness, satisfaction, and thoughts of food compared with saline-to-ileum (Tukey's post hoc, P < 0.05); decreased ad libitum EI at lunch compared with glucose-to-duodenum [-22%, -988 ± 379 kJ (mean ± SEM), Tukey's post hoc, P < 0.05]; and increased glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) compared with all other treatments (Tukey's post hoc, P < 0.05). Conclusions: Macronutrient delivery to the proximal and distal small intestine elicits different outcomes. Glucose infusion to the ileum increased GLP-1 and PYY secretion, suppressed aspects of VAS-rated appetite, and decreased ad libitum EI at a

  9. Multivariable normal tissue complication probability model-based treatment plan optimization for grade 2-4 dysphagia and tube feeding dependence in head and neck radiotherapy.

    PubMed

    Kierkels, Roel G J; Wopken, Kim; Visser, Ruurd; Korevaar, Erik W; van der Schaaf, Arjen; Bijl, Hendrik P; Langendijk, Johannes A

    2016-12-01

    Radiotherapy of the head and neck is challenged by the relatively large number of organs-at-risk close to the tumor. Biologically-oriented objective functions (OF) could optimally distribute the dose among the organs-at-risk. We aimed to explore OFs based on multivariable normal tissue complication probability (NTCP) models for grade 2-4 dysphagia (DYS) and tube feeding dependence (TFD). One hundred head and neck cancer patients were studied. Additional to the clinical plan, two more plans (an OF DYS and OF TFD -plan) were optimized per patient. The NTCP models included up to four dose-volume parameters and other non-dosimetric factors. A fully automatic plan optimization framework was used to optimize the OF NTCP -based plans. All OF NTCP -based plans were reviewed and classified as clinically acceptable. On average, the Δdose and ΔNTCP were small comparing the OF DYS -plan, OF TFD -plan, and clinical plan. For 5% of patients NTCP TFD reduced >5% using OF TFD -based planning compared to the OF DYS -plans. Plan optimization using NTCP DYS - and NTCP TFD -based objective functions resulted in clinically acceptable plans. For patients with considerable risk factors of TFD, the OF TFD steered the optimizer to dose distributions which directly led to slightly lower predicted NTCP TFD values as compared to the other studied plans. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. An investigation into magnetic electrolytic abrasive turning

    NASA Astrophysics Data System (ADS)

    Mahdy, M. A. M.; Ismaeial, A. L.; Aly, F. F.

    2013-07-01

    The magnetic electrolytic abrasive turning (MEAT) process as a non-traditional machining is used to obtain surface finishing like mirror. MEAT provides one of the best alternatives for producing complex shapes with good finish in advanced materials used in aircraft and aerospace industries. The improvement of machining accuracy of MEAT continues to be a major challenge for modern industry. MEAT is a hybrid machining which combines two or more processes to remove material. The present research focuses on the development of precision electrochemical turning (ECT) under the effects of magnetic field and abrasives. The effect of magnetic flux density, electrochemical conditions and abrasive parameters on finishing efficiency and surface roughness are investigated. An empirical relationship is deduced.

  11. The effect of microstructure on abrasive wear of steel

    NASA Astrophysics Data System (ADS)

    Kešner, A.; Chotëborský, R.; Linda, M.

    2017-09-01

    Abrasive wear of agricultural tools is one of the biggest problems in currently being. The amount of abrasive wear, depending on the microstructure, has been investigated in this work. Steels 25CrMo4 and 51CrV4 were used in this work to determine the effect of the microstructure on the abrasive wear. These steels are commonly used for components that have to withstand abrasive wear.SEM analysis was used to detect the microstructure. The standardized ASTM G65 method was used to compare the abrasive wear of steels. The results show that the abrasive wear depends on the microstructure of steels.

  12. Friction and abrasion of elastomeric materials

    NASA Technical Reports Server (NTRS)

    Gent, A. N.

    1975-01-01

    An abrasion apparatus is described. Experimental measurements are reported for four representative elastomeric materials, including a typical high-quality tire tread material and a possible replacement material for aircraft tire treads based on transpolypentenamer (TPPR). Measurements are carried out at different levels of frictional work input, corresponding to different severities of wear, and at both ambient temperature and at 100 C. Results indicate the marked superiority in abrasion resistance of the material based on TPPR, especially at 100 C, in comparison with the other materials examined.

  13. Mars Pathfinder: The Wheel Abrasion Experiment

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA Lewis Research Center's Wheel Abrasion Experiment (WAE) will measure the amount of wear on wheel surfaces of the Mars Pathfinder rover. WAE uses thin films of Al, Ni, and Pt (ranging in thickness from 200 to 1000 angstroms) deposited on black, anodized Al strips attached to the rover wheel. As the wheel moves across the martian surface, changes in film reflectivity will be monitored by reflected sunlight. These changes, measured as output from a special photodetector mounted on the rover chassis, will be due to abrasion of the metal films by martian surface sand, dust, and clay.

  14. Abrasion of eroded and sound enamel by a dentifrice containing diamond abrasive particles

    PubMed

    Wegehaupt, Florian J.; Hoegger, Vanessa G. M.; Attin, Thomas

    2017-07-24

    Eroded enamel is more susceptible to abrasive wear than sound enamel. New toothpastes utilizing diamond particles as abrasives have been developed. The present study investigated the abrasive wear of eroded enamel by three commercially available toothpastes (one containing diamond particles) and compared it to the respective wear of sound enamel caused by these toothpastes. Seventy-two bovine enamel samples were randomly allocated to six groups (S1–S3 and E1–E3; n=12). Samples were submitted to an abrasive (S1–S3) or erosion plus abrasion (E1–E3) cycling. Per cycle, all samples were brushed (abrasion; 20 brushing stokes) with the following toothpastes: S1/E1: Signal WHITE SYSTEM, S2/E2: elmex KARIESSCHUTZ and S3-E3: Candida WHITE DIAMOND (diamond particles). Groups E1–E3 were additionally eroded with HCl (pH 3.0) for 2 min before each brushing procedure. After 30, 60 and 90 cycles enamel wear was measured by surface profilometry. Within the same toothpaste and same number of cycles, enamel wear due to erosion plus abrasion was significantly higher than due to mere abrasion. After 30, 60 and 90 cycles, no significant difference in the wear in groups S1 and S2 was observed while the wear in group E1 was significantly (p<0.05, ANOVA, Scheffecyc) lower than that in group E2. After 90 cycles, wear in group S3 was about 5 times higher than that in group S2, while wear in group E3 was about 1.3 times higher than that in group E2. As compared to the other two investigated toothpastes, the dentifrice containing diamond particles caused slightly higher abrasive wear of eroded enamel and distinctly higher wear of sound enamel compared to the conventional toothpastes under investigation.

  15. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories... crowns. The device is attached to a shank that is held by a handpiece. The device includes the abrasive...

  16. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing.... The abrasive polish is applied to the teeth by a handpiece attachment (prophylaxis cup). (b...

  17. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing.... The abrasive polish is applied to the teeth by a handpiece attachment (prophylaxis cup). (b...

  18. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing.... The abrasive polish is applied to the teeth by a handpiece attachment (prophylaxis cup). (b...

  19. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories... crowns. The device is attached to a shank that is held by a handpiece. The device includes the abrasive...

  20. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories... crowns. The device is attached to a shank that is held by a handpiece. The device includes the abrasive...

  1. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing.... The abrasive polish is applied to the teeth by a handpiece attachment (prophylaxis cup). (b...

  2. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories... crowns. The device is attached to a shank that is held by a handpiece. The device includes the abrasive...

  3. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing.... The abrasive polish is applied to the teeth by a handpiece attachment (prophylaxis cup). (b...

  4. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and accessories... crowns. The device is attached to a shank that is held by a handpiece. The device includes the abrasive...

  5. An epidemiologic approach to toothbrushing and dental abrasion.

    PubMed

    Bergström, J; Lavstedt, S

    1979-02-01

    Abrasion lesions were recorded in 818 individuals representing the adult population of 430,000 residents of the Stockholm region, Sweden. The subjects were asked about toothbrushing habits, toothbrush quality and dentifrice usage; these factors were related to abrasion criteria. Abrasion was prevalent in 30% and wedge-like or deep depressions were observed in 12%. The relationship between abrasion and toothbrushing was evident, the prevalence and severity of abrasion being correlated to toothbrushing consumption. The importance of the toothbrushing technique for the development of abrasion lesions was elucidated. Horizontal brushing technique was strongly correlated to abrasion. It was demonstrated by treating the data with the statistical AID analysis that toothbrushing factors related to the individual (brushing frequency and brushing technique) exert a greater influence than material-oriented toothbrushing factor such as dentifrice abrasivity and bristle stiffness.

  6. Clinical utility of topiramate extended-release capsules (USL255): Bioequivalence of USL255 sprinkled and intact capsule in healthy adults and an in vitro evaluation of sprinkle delivery via enteral feeding tubes.

    PubMed

    Clark, Annie M; Pellock, John M; Holmay, Mary; Anders, Bob; Cloyd, James

    2016-04-01

    The objectives of these two studies were to determine if beads from extended-release topiramate capsules sprinkled onto soft food are bioequivalent to the intact capsule and if beads from the capsule can be passed through enteral gastrostomy (G-) and jejunostomy (J-) feeding tubes. Bioequivalence of 200-mg USL255 (Qudexy XR [topiramate] extended-release capsules) sprinkled onto soft food (applesauce) versus the intact capsule was evaluated in a phase 1, randomized, single-dose, crossover study (N=36). Pharmacokinetic evaluations included area under the curve (AUC), maximum plasma concentration (Cmax), time to Cmax (Tmax), and terminal elimination half-life (t1/2). If 90% confidence intervals (CI) of the ratio of geometric least-squares means were between 0.80 and 1.25, AUC and Cmax were considered bioequivalent. In separate in vitro experiments, 100-mg USL255 beads were passed through feeding tubes using gentle syringe pressure to develop a clog-free bead-delivery method. Multiple tube sizes (14- to 18-French [Fr] tubes), dilutions (5 mg/15 mL-25 mg/15 mL), and diluents (deionized water, apple juice, Ketocal, sparkling water) were tested. Area under the curve and Cmax for USL255 beads sprinkled onto applesauce were bioequivalent to the intact capsule (GLSM [90% CI]: AUC0-t 1.01 [0.97-1.04], AUC0-∞ 1.02 [0.98-1.05]; Cmax 1.09 [1.03-1.14]). Median Tmax was 4h earlier for USL255 sprinkled versus the intact capsule (10 vs 14 h; p=0.0018), and t1/2 was similar (84 vs 82 h, respectively). In 14-Fr G-tubes, USL255 beads diluted in Ketocal minimized bead clogging versus deionized water. Recovery of USL255 beads diluted in deionized water was nearly 100% in 16-Fr G-, 18-Fr G-, and 18-Fr J-tubes. For patients with difficulty swallowing pills, USL255 sprinkled onto applesauce offers a useful once-daily option for taking topiramate. USL255 beads were also successfully delivered in vitro through ≥14-Fr G- or J-tubes, with tube clogging minimized by portioning the dose and

  7. Gastrostomy feeding tube - pump - child

    MedlinePlus

    ... at home. In: O'Keefe SJD, ed. The Principles and Practice of Nutritional Support . New York, NY: Springer; 2015:chap 10. Schattner MA, Grossman EB. Nutritional management. In: Feldman M, Friedman LS, Brandt LJ, eds. ...

  8. Robotic edge machining using elastic abrasive tool

    NASA Astrophysics Data System (ADS)

    Sidorova, A. V.; Semyonov, E. N.; Belomestnykh, A. S.

    2018-03-01

    The article describes a robotic center designed for automation of finishing operations, and analyzes technological aspects of an elastic abrasive tool applied for edge machining. Based on the experimental studies, practical recommendations on the application of the robotic center for finishing operations were developed.

  9. Body Weight and Body Mass Index in Patients with End-Stage Cystic Fibrosis Stabilize After the Start of Enteral Tube Feeding.

    PubMed

    Hollander, Francis M; de Roos, Nicole M; Belle van Meerkerk, Gerdien; Teding van Berkhout, Ferdinand; Heijerman, Harry G M; van de Graaf, Ed A

    2017-11-01

    Enteral tube feeding (ETF) is widely used in patients with cystic fibrosis (CF) and end-stage lung disease, but previous studies have been limited to investigating whether ETF improves outcomes in patients with moderately or mildly impaired pulmonary function. This study investigated body weight, body mass index (BMI; calculated as kg/m 2 ), pulmonary function, and the presence of CF-related diabetes before and after the start of ETF. This was a retrospective observational study. Data from 26 adult patients in an outpatient setting who had end-stage CF (19 women) and had been using ETF for at least 6 months between 2000 and 2014 were analyzed. Body weight, BMI, pulmonary function (forced expiratory volume in 1 second as percent of predicted) and incidence of CF-related diabetes from 6 months before to 6 months after starting ETF. Time effects were tested with one-way analysis of variance for data that were normally distributed and the Friedman test for non-parametric data. Correlations were tested with Pearson's r or Spearman's ρ, depending on the distribution of the data. Mean body weight increased by 3.5 kg (95% CI 2.2 to 4.8 kg) after patients started ETF. In women, mean BMI decreased by 0.7 in the 6 months before the start of ETF (P<0.05) and increased by 1.4 in the 6 months thereafter (P<0.05). In men, BMI changes were similar (-0.8 and +1.1), but not statistically significant. Forced expiratory volume in 1 second as percent of predicted significantly decreased in time from a median of 28% to 26% at the start of ETF to 25% after 6 months (P=0.0013), with similar trends in women and men. There was no correlation between changes in weight and lung function. CF-related diabetes was already present in 12 patients and developed in 1 more patient after the start of ETF. ETF improved body weight and BMI but not pulmonary function in 26 patients with end-stage CF. Clinical outcomes were similar in women and men, but the sample size of men was too small to determine

  10. Tube support

    DOEpatents

    Mullinax, Jerry L.

    1988-01-01

    A tube support for supporting horizontal tubes from an inclined vertical support tube passing between the horizontal tubes. A support button is welded to the vertical support tube. Two clamping bars or plates, the lower edges of one bearing on the support button, are removably bolted to the inclined vertical tube. The clamping bars provide upper and lower surface support for the horizontal tubes.

  11. Abrasive slurry composition for machining boron carbide

    DOEpatents

    Duran, E.L.

    1984-11-29

    An abrasive slurry particularly suited for use in drilling or machining boron carbide consists essentially of a suspension of boron carbide and/or silicon carbide grit in a carrier solution consisting essentially of a dilute solution of alkylaryl polyether alcohol in octyl alcohol. The alkylaryl polyether alcohol functions as a wetting agent which improves the capacity of the octyl alcohol for carrying the grit in suspension, yet without substantially increasing the viscosity of the carrier solution.

  12. Abrasive slurry composition for machining boron carbide

    DOEpatents

    Duran, Edward L.

    1985-01-01

    An abrasive slurry particularly suited for use in drilling or machining boron carbide consists essentially of a suspension of boron carbide and/or silicon carbide grit in a carrier solution consisting essentially of a dilute solution of alkylaryl polyether alcohol in octyl alcohol. The alkylaryl polyether alcohol functions as a wetting agent which improves the capacity of the octyl alcohol for carrying the grit in suspension, yet without substantially increasing the viscosity of the carrier solution.

  13. Explosibility and Ignitability of Plastic Abrasive Media.

    DTIC Science & Technology

    1987-06-01

    Polyplus Is an alpha cellulose filled urea formaldehyde with a hardness or 3.5. Type III is a urea melamine formaldehyde with a hardness of 4. A fourth...is a thermoplastic acrylic media and the Kopper’s media are thermoset formaldehydes . o The greatest potential for dust explosions is in the baghouss...type or plastio media trom E. I. Du Pont de Nemours and Company was also tested. This Type L Solidstrip plastic stripping abrasive is an acrylic resin

  14. Dentin abrasivity of various desensitizing toothpastes.

    PubMed

    Arnold, W H; Gröger, Ch; Bizhang, M; Naumova, E A

    2016-04-02

    The aim of this study was to compare the abrasivity of various commercially available toothpastes that claim to reduce dentin hypersensitivity. Dentin discs were prepared from 70 human extracted molars. The discs were etched with lemon juice for 5 min, and one half of the discs were covered with aluminum tape. Following this, they were brushed with 6 different toothpastes, simulating a total brushing time of 6 months. As a negative control, discs were brushed with tap water only. The toothpastes contained pro-arginine and calcium carbonate, strontium acetate, stannous fluoride, zinc carbonate and hydroxyapatite, new silica, or tetrapotassium pyrophosphate and hydroxyapatite. After brushing, the height differences between the control halves and the brushed halves were determined with a profilometer and statistically compared using a Mann-Whitney U test for independent variables. A significant difference (p < 0.001) in height difference between the controls and the toothpaste-treated samples was found in all cases, except for the stannous fluoride-containing toothpaste (p = 0.583). The highest abrasion was found in the toothpaste containing zinc carbonate and hydroxyapatite, and the lowest was found in the toothpaste containing pro-arginine and calcium carbonate. Desensitizing toothpastes with different desensitizing ingredients have different levels of abrasivity, which may have a negative effect on their desensitizing abilities over a long period of time.

  15. Using a nasogastric tube.

    PubMed

    Candy, C

    1986-09-01

    This discussion of the use of a nasogastric tube covers the equipment needed, the method, rehydration and feeding, prolonged nasogastric feeding, and stopping nasogastric feeding. A nasogastric tube is useful when children are unable to drink safely and in sufficient amounts for any of the following reasons: severe dehydration; if intravenous (IV) therapy is unavailable; low birth weight infants; or the child is drowsy or vomiting. Severely malnourished children may be fed initially in this way if they are too weak or anorexic to eat or drink normally. The following equipment is needed: nasogastric tube; lubricating fluid; a syringe; blue litmus paper, if available; adhesive tape; stethoscope if available; and fluid to be given. Explain to the child's parents and the child, if old enough to understand, what will be done; lie infants flat; measure the approximate length from the child's nostril to the ear lobe and then to the top of the abdomen with the tube and mark the position; clean the nostrils to remove the mucus, and lubricate the tip of the tube and gently insert into the nostril; give the child a drink of water if he or she is conscious; continue to pass the tube down until the position marked reaches the nostril; use the syringe to suck up some fluid and test with blue litmus paper to check that the tube is in the stomach; and inject 5-10 ml of fluid (saline or oral rehydration solution, not milk formula) by syringe if satisfied the tube is in the correct position. Where possible, give a continuous drip of fluid. If this is not possible, give frequent small amounts using the syringe as a funnel. If feeding continues for more than 24 hours, clean the nostrils daily with warm water and change the tube to the other nostril every few days. Also keep the mouth very clean with a dilute solution of 8% sodium bicarbonate, if available, or citrus fruit juice. To remove the tube, remove the adhesive tape, take the tube out gently and smoothly, and offer the child a

  16. Do Abrasives Play a Role in Toothpaste Efficacy against Erosion/Abrasion?

    PubMed

    Ganss, Carolina; Möllers, Maike; Schlueter, Nadine

    2017-01-01

    Abrasives may counteract the efficacy of anti-erosion toothpastes either due to physical effects or due to interaction with active agents. This study aimed to investigate whether the amount of abrasives is a determinant for the efficacy of Sn2+-containing toothpastes with or without chitosan additive. Enamel samples were eroded (0.50 wt% citric acid, pH 2.5; 6 × 2 min/day) on a shaking desk - 30/min in experiment 1 (E1) and 35/min in experiments 2 (E2) and 3 (E3) - and immersed in toothpaste slurries (2 × 2 min). Half of the samples were additionally brushed (15 s, load 200 g) within the immersion time. The toothpastes contained 0, 5, 10, 15, and 20% silica. In E1 and E2 the active ingredients were F- (700 ppm as amine fluoride, 700 ppm as NaF) and Sn2+ (3,500 ppm as SnCl2); in E3 chitosan (0.5%) was additionally added. The placebo contained 20% silica. Tissue loss was determined profilometrically. In E1, slurries completely inhibited tissue loss; distinct surface deposits occurred. With brushing, tissue loss significantly increased up to an abrasive content of 10%, but decreased significantly with higher amounts; 20% silica revealed similar values as the abrasive-free formulation. In E2, all slurries inhibited tissue loss distinctly irrespective of the amounts of abrasives. With brushing, a similar trend as in E1 was observed but with much less efficacy. The chitosan-containing formulations in E3 were much more effective; similar results as in E1 were found. In conclusion, the amount of abrasives had no effect when toothpastes were applied as slurries, but played an important role with brushing. © 2016 S. Karger AG, Basel.

  17. Hydrogen water intake via tube-feeding for patients with pressure ulcer and its reconstructive effects on normal human skin cells in vitro

    PubMed Central

    2013-01-01

    Background Pressure ulcer (PU) is common in immobile elderly patients, and there are some research works to investigate a preventive and curative method, but not to find sufficient effectiveness. The aim of this study is to clarify the clinical effectiveness on wound healing in patients with PU by hydrogen-dissolved water (HW) intake via tube-feeding (TF). Furthermore, normal human dermal fibroblasts OUMS-36 and normal human epidermis-derived cell line HaCaT keratinocytes were examined in vitro to explore the mechanisms relating to whether hydrogen plays a role in wound-healing at the cellular level. Methods Twenty-two severely hospitalized elderly Japanese patients with PU were recruited in the present study, and their ages ranged from 71.0 to 101.0 (86.7 ± 8.2) years old, 12 male and 10 female patients, all suffering from eating disorder and bedridden syndrome as the secondary results of various underlying diseases. All patients received routine care treatments for PU in combination with HW intake via TF for 600 mL per day, in place of partial moisture replenishment. On the other hand, HW was prepared with a hydrogen-bubbling apparatus which produces HW with 0.8-1.3 ppm of dissolved hydrogen concentration (DH) and −602 mV to −583 mV of oxidation-reduction potential (ORP), in contrast to reversed osmotic ultra-pure water (RW), as the reference, with DH of < 0.018 ppm and ORP of +184 mV for use in the in vitro experimental research. In in vitro experiments, OUMS-36 fibroblasts and HaCaT keratinocytes were respectively cultured in medium prepared with HW and/or RW. Immunostain was used for detecting type-I collagen reconstruction in OUMS-36 cells. And intracellular reactive oxygen species (ROS) were quantified by NBT assay, and cell viability of HaCaT cells was examined by WST-1 assay, respectively. Results Twenty-two patients were retrospectively divided into an effective group (EG, n = 12) and a less effective group (LG, n = 10) according to

  18. Numerical simulation of polishing U-tube based on solid-liquid two-phase

    NASA Astrophysics Data System (ADS)

    Li, Jun-ye; Meng, Wen-qing; Wu, Gui-ling; Hu, Jing-lei; Wang, Bao-zuo

    2018-03-01

    As the advanced technology to solve the ultra-precision machining of small hole structure parts and complex cavity parts, the abrasive grain flow processing technology has the characteristics of high efficiency, high quality and low cost. So this technology in many areas of precision machining has an important role. Based on the theory of solid-liquid two-phase flow coupling, a solid-liquid two-phase MIXTURE model is used to simulate the abrasive flow polishing process on the inner surface of U-tube, and the temperature, turbulent viscosity and turbulent dissipation rate in the process of abrasive flow machining of U-tube were compared and analyzed under different inlet pressure. In this paper, the influence of different inlet pressure on the surface quality of the workpiece during abrasive flow machining is studied and discussed, which provides a theoretical basis for the research of abrasive flow machining process.

  19. Mars Pathfinder Wheel Abrasion Experiment Ground Test

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Siebert, Mark W.

    1998-01-01

    The National Aeronautics and Space Administration (NASA) sent a mission to the martian surface, called Mars Pathfinder. The mission payload consisted of a lander and a rover. The primary purpose of the mission was demonstrating a novel entry, descent, and landing method that included a heat shield, a parachute, rockets, and a cocoon of giant air bags. Once on the surface, the spacecraft returned temperature measurements near the Martian surface, atmosphere pressure, wind speed measurements, and images from the lander and rover. The rover obtained 16 elemental measurements of rocks and soils, performed soil-mechanics, atmospheric sedimentation measurements, and soil abrasiveness measurements.

  20. Abrasion-Resistant Coating for Flexible Insulation

    NASA Technical Reports Server (NTRS)

    Mui, D.; Headding, R. E.

    1986-01-01

    Ceramic coating increases durability and heat resistance of flexible high-temperature insulation. Coating compatible with quartz-fabric insulation allowing it to remain flexible during and after repeated exposures to temperatures of 1,800 degree F (982 degree C). Prevents fabric from becoming brittle while increasing resistance to aerodynamic abrasion and loading. Coating consists of penetrating precoat and topcoat. Major ingredients high-purity colloidal silica binder and ground silica filler, which ensure stability and compatibility with fabric at high temperatures. Both precoat and topcoat cured at room temperature.

  1. Compression device for feeding a waste material to a reactor

    DOEpatents

    Williams, Paul M.; Faller, Kenneth M.; Bauer, Edward J.

    2001-08-21

    A compression device for feeding a waste material to a reactor includes a waste material feed assembly having a hopper, a supply tube and a compression tube. Each of the supply and compression tubes includes feed-inlet and feed-outlet ends. A feed-discharge valve assembly is located between the feed-outlet end of the compression tube and the reactor. A feed auger-screw extends axially in the supply tube between the feed-inlet and feed-outlet ends thereof. A compression auger-screw extends axially in the compression tube between the feed-inlet and feed-outlet ends thereof. The compression tube is sloped downwardly towards the reactor to drain fluid from the waste material to the reactor and is oriented at generally right angle to the supply tube such that the feed-outlet end of the supply tube is adjacent to the feed-inlet end of the compression tube. A programmable logic controller is provided for controlling the rotational speed of the feed and compression auger-screws for selectively varying the compression of the waste material and for overcoming jamming conditions within either the supply tube or the compression tube.

  2. Sparing the larynx and esophageal inlet expedites feeding tube removal in patients with stage III-IV oropharyngeal squamous cell carcinoma treated with intensity-modulated radiotherapy.

    PubMed

    Amin, Neha; Reddy, Krishna; Westerly, David; Raben, David; DeWitt, Peter; Chen, Changhu

    2012-12-01

    To evaluate the effect of larynx and esophageal inlet sparing on dysphagia recovery after intensity-modulated radiotherapy (IMRT) for stage III-IV oropharyngeal squamous cell carcinoma. Retrospective study. Of 88 patients treated with IMRT, 38 were planned with a larynx + esophageal inlet mean dose <50 Gy constraint, 27 with a larynx alone mean dose constraint of <50 Gy, and 23 without a larynx/esophagus constraint. All had a percutaneous endoscopic gastrostomy (PEG) tube placed before IMRT, which was removed when the patient could swallow and maintain weight. All IMRT plans were retrieved, and the larynx; esophageal inlet; and superior, middle, and inferior constrictors were contoured. Dosimetric data were correlated with PEG tube dependence duration. The PEG tube was removed within 3, 6, 9, and 12 months after IMRT in 24%, 61%, 71%, and 83% of patients, respectively. Median times to PEG tube removal were 3.7 and 8.6 months (P = .0029) in patients planned with or without a larynx/larynx + esophageal inlet dose constraint. A mean dose to the larynx + esophageal inlet of ≤60 Gy reduced the median PEG tube duration from 10.8 to 6.1 months (P = .02), compared to >60 Gy. Mean pharyngeal constrictor doses in patients receiving a mean dose to the larynx + esophageal inlet of ≤50 Gy versus >50 Gy were: 60 Gy and 69 Gy, 55 Gy and 67 Gy, and 47 Gy and 57 Gy, for the superior, middle, and inferior constrictors, respectively (P < .0001). A dose constraint on the larynx and esophageal inlet during IMRT planning reduces dose to pharyngeal constrictors and expedites PEG tube removal. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  3. A prospective study comparing prophylactic gastrostomy to nutritional counselling with a therapeutic feeding tube if required in head and neck cancer patients undergoing chemoradiotherapy in Thai real-world practice.

    PubMed

    Pramyothin, P; Manyanont, S; Trakarnsanga, A; Petsuksiri, J; Ithimakin, S

    2016-12-01

    Concurrent chemoradiotherapy (CRT) is the standard treatment for head and neck (HN) cancer patients. Most patients experience malnutrition and weight loss during treatment because of mucositis and difficulty in swallowing. Prevention of malnutrition may allow more patients to complete their treatment. The present study aimed to examine whether prophylactic gastrostomy tube (PGT) could reduce treatment interruption, prevent malnutrition and maintain quality of life, especially in Thai patients who generally do not accept feeding tubes. A prospective study was performed on HN cancer patients undergoing CRT at a tertiary hospital in Thailand (n = 95). Before starting CRT, all patients received nutritional assessment and were counselled about the risks and benefits of PGT. According to patient discretion, they chose to have a PGT (experimental group) or only nutritional counselling with a therapeutic feeding tube if required (control group). During CRT, weight, degree of mucositis, delayed chemotherapy and/or radiotherapy, and nutritional status were recorded. Quality of life (Functional Assessment of Cancer Therapy - Head and Neck Scale; FACT-H&N) was compared between two groups. There was no significant difference in the rates of delayed treatment. Mean weight loss was 3.1 and 4.8 kg in the experimental and control groups, respectively (P = 0.04). A higher proportion of patients in the control group experienced ≥10% weight loss (24% versus 4%; P = 0.03). In terms of quality of life, no significant difference in FACT-H&N score was found. The results of the present study suggest that PGT provided similar quality of life without a reduction in treatment interruption. However, patients with PGT had significantly less weight loss (P = 0.04) during CRT. © 2016 The British Dietetic Association Ltd.

  4. [INFLUENCE OF THE NUTRITIONAL COMPOSITION OF DIFFERENT FIBER-ENRICHED ENTERAL NUTRITION FORMULAS ON THE ADMINISTRATION TIME BY GRAVITY AND THE RISK OF TUBE FEEDING OBSTRUCTION].

    PubMed

    Bonada Sanjaume, Anna; Gils Contreras, Anna; Salas-Salvadó, Jordi

    2015-08-01

    the administration of enteral nutrition by gravity is a very useful method in clinical practice; nevertheless, it may not be very precise. Indeed, this method presents some important limitations, such as the difficulty in establishing a precise dripping rate and the possibility for the dripping rate decrease depending on the formula. assess the administration time and the risk of clogging of 5 fiber-enriched enteral nutrition formulas with different protein concentrations and caloric density, all administered by gravity through nasogastric (NG) tubes of different sizes. Assess the influence of the composition on the dripping rate, by gravity, of the tested formulas. 5 fiber-enriched EN formulas were compared by using nasogastric tubes of the calibers 8, 10 and 12 Fr. The fluidity of these gravity-administered NE formulas was estimated by timing the complete passage of each formula at full speed, thus allowing one to calculate the mean time of free fall (MTFF) and to register any possible obstruction. Subsequently, an in vitro simulation of a 1 500 ml administration was performed for each formula at a particular speed, so that the administration time was 5 hours. Slowing flow and stagnated flow were detected as indicators of the risk of obstruction. the two products that especially differed in MTFF were the ones with the highest energy concentration. The passage time in free fall of these two products through the 8 Fr tube exceeded four hours. For the rest of the products and NG tubes used, this time was less than 2 hours and 5 minutes. No slowing flow or tube obstruction was detected in free fall and at maximum speed. When the dripping was adjusted to be administered in 5 hours, three of the studied products (those with the least caloric concentration and viscosity) showed slowing flow and, in some cases, the dripping stopped completely. The most important factor associated to the MTFF was the lipid content, followed by viscosity, energy and protein content. The

  5. Analysis of acoustic emission during abrasive waterjet machining of sheet metals

    NASA Astrophysics Data System (ADS)

    Mokhtar, Nazrin; Gebremariam, MA; Zohari, H.; Azhari, Azmir

    2018-04-01

    The present paper reports on the analysis of acoustic emission (AE) produced during abrasive waterjet (AWJ) machining process. This paper focuses on the relationship of AE and surface quality of sheet metals. The changes in acoustic emission signals recorded by the mean of power spectral density (PSD) via covariance method in relation to the surface quality of the cut are discussed. The test was made using two materials for comparison namely aluminium 6061 and stainless steel 304 with five different feed rates. The acoustic emission data were captured by Labview and later processed using MATLAB software. The results show that the AE spectrums correlated with different feed rates and surface qualities. It can be concluded that the AE is capable of monitoring the changes of feed rate and surface quality.

  6. Evaluation of the educational technology "Caring for dependent people" by family caregivers in changes and transfers of patients and tube feeding.

    PubMed

    Landeiro, Maria José Lumini; Peres, Heloísa Helena Ciqueto; Martins, Teresa Vieira

    2016-08-18

    to assess the contributions of interactive educational technology "Caring for Dependent People" in the development of knowledge to family caregivers of dependent people in a household context and their satisfaction in its use. quasi-experimental study, not randomized, of the before and after type, with a convenience sample of 65 family caregivers, from two Medicine services of a hospital in Porto, Portugal. The Control Group consisted of 33 family caregivers and the Experimental Group of 32, identified by consecutive sampling. The experimental group had access to educational technology at home. Data were collected by socio-demographic, satisfaction and evaluation of knowledge questionnaire, about how to feed by nasogastric tube, positioning and transferring the dependent person. The assessment in both groups had two moments: initial, during hospitalization and one month after discharge. the experimental group had a larger increase in knowledge related to the use of the educational technology. In the control group the knowledge did not differ in the two evaluation time points. these results confirm the improvement of interactive educational technologies and in the training of family caregivers to care for dependents. This technology successfully met the technical quality and learning needs of caregivers, and was considered easy and stimulating. avaliar os contributos da tecnologia educacional interativa "Cuidar de Pessoas Dependentes" no desenvolvimento de conhecimentos aos familiares cuidadores de pessoas dependentes, no contexto domiciliário e a satisfação no seu uso. estudo quasi-experimental, não randomizado, do tipo antes e depois, com amostra de conveniência constituída por 65 familiares cuidadores, de dois Serviços de Medicina de um hospital do Porto, Portugal. O Grupo Controle foi constituído por 33 familiares cuidadores e o Grupo Experimental por 32, identificados por amostragem consecutiva. O grupo experimental teve Acesso à tecnologia educacional

  7. Experimental Rock-on-Rock Abrasive Wear Under Aqueous Conditions: its Role in Subglacial Abrasion

    NASA Astrophysics Data System (ADS)

    Rutter, E. H.; Lee, A. G.

    2003-12-01

    We have determined experimentally the rate of abrasive wear of rock on rock for a range of rock types as a function of normal stress and shear displacement. Unlike abrasive wear in fault zones, where wear products accumulate as a thickening gouge zone, in our experiments wear particles were removed by flowing water. The experiments are thus directly pertinent to one of the most important processes in subglacial erosion, and to some extent in river incision. Wear was produced between rotating discs machined from rock samples and measured from the progressive approach of the disc axes towards each other under various levels of normal load. Shear displacements of several km were produced. Optical and scanning electron microscopy were used to study the worn rock surfaces, and particle size distributions in wear products were characterized using a laser particle size analyzer. Rock types studied were sandstones of various porosities and cement characteristics, schists and a granite. In all cases abrasion rate decreased logarithmically with displacement by up to 2 orders of magnitude until a steady state was approached, but only after at least 1 km displacement. The more porous, less-well cemented rocks wore fastest. Amount of abrasion could be characterized quantitatively using an exponentially decaying plus a steady-state term. Wear rate increased non-linearly with normal contact stress, apparently to an asymptote defined by the unconfined compressive strength. Microstructural study showed that the well-cemented and/or lowest porosity rocks wore by progressive abrasion of grains without plucking, whereas whole grains were plucked out of weakly-cemented and/or more porous rocks. This difference in behavior was reflected in wear-product particle size distributions. Where whole-grain plucking was possible, wear products were dominated by particles of the original grain size rather than finer rock flour. Comparison of our results to glacier basal abrasive wear estimated

  8. Rock Cutting Depth Model Based on Kinetic Energy of Abrasive Waterjet

    NASA Astrophysics Data System (ADS)

    Oh, Tae-Min; Cho, Gye-Chun

    2016-03-01

    Abrasive waterjets are widely used in the fields of civil and mechanical engineering for cutting a great variety of hard materials including rocks, metals, and other materials. Cutting depth is an important index to estimate operating time and cost, but it is very difficult to predict because there are a number of influential variables (e.g., energy, geometry, material, and nozzle system parameters). In this study, the cutting depth is correlated to the maximum kinetic energy expressed in terms of energy (i.e., water pressure, water flow rate, abrasive feed rate, and traverse speed), geometry (i.e., standoff distance), material (i.e., α and β), and nozzle system parameters (i.e., nozzle size, shape, and jet diffusion level). The maximum kinetic energy cutting depth model is verified with experimental test data that are obtained using one type of hard granite specimen for various parameters. The results show a unique curve for a specific rock type in a power function between cutting depth and maximum kinetic energy. The cutting depth model developed here can be very useful for estimating the process time when cutting rock using an abrasive waterjet.

  9. Microwave sintering of sol-gel derived abrasive grain

    DOEpatents

    Plovnick, Ross; Celikkaya, Ahmet; Blake, Rodger D.

    1997-01-01

    A method is provided for making microwave-sintered, free flowing alpha alumina-based ceramic abrasive grain, under conditions effective to couple microwaves with calcined alpha alumina-based abrasive gain precursor and sinter it at a temperature of at least about 1150.degree. C.

  10. 7 CFR 3201.66 - Cuts, burns, and abrasions ointments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Cuts, burns, and abrasions ointments. 3201.66 Section... PROCUREMENT Designated Items § 3201.66 Cuts, burns, and abrasions ointments. (a) Definition. Products designed..., in accordance with this part, will give a procurement preference for qualifying biobased cuts, burns...

  11. 7 CFR 3201.66 - Cuts, burns, and abrasions ointments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Cuts, burns, and abrasions ointments. 3201.66 Section... PROCUREMENT Designated Items § 3201.66 Cuts, burns, and abrasions ointments. (a) Definition. Products designed..., in accordance with this part, will give a procurement preference for qualifying biobased cuts, burns...

  12. 7 CFR 3201.66 - Cuts, burns, and abrasions ointments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Cuts, burns, and abrasions ointments. 3201.66 Section... PROCUREMENT Designated Items § 3201.66 Cuts, burns, and abrasions ointments. (a) Definition. Products designed..., in accordance with this part, will give a procurement preference for qualifying biobased cuts, burns...

  13. Evaluation of abrasion resistance of pipe and pipe lining materials.

    DOT National Transportation Integrated Search

    2007-09-01

    This project summarizes an evaluation of pipe material resistance to abrasion over a 5-year period (2001-2006) at a site known to be abrasive. : The key focus of the project was to gather more information to compare against existing guidance to desig...

  14. Tooth wear: attrition, erosion, and abrasion.

    PubMed

    Litonjua, Luis A; Andreana, Sebastiano; Bush, Peter J; Cohen, Robert E

    2003-06-01

    Attrition, erosion, and abrasion result in alterations to the tooth and manifest as tooth wear. Each classification acts through a distinct process that is associated with unique clinical characteristics. Accurate prevalence data for each classification are not available since indices do not necessarily measure one specific etiology, or the study populations may be too diverse in age and characteristics. The treatment of teeth in each classification will depend on identifying the factors associated with each etiology. Some cases may require specific restorative procedures, while others will not require treatment. A review of the literature points to the interaction of the three entities in the initiation and progression of lesions that may act synchronously or sequentially, synergistically or additively, or in conjunction with other entities to mask the true nature of tooth wear, which appears to be multifactorial.

  15. Performance analysis of cutting graphite-epoxy composite using a 90,000psi abrasive waterjet

    NASA Astrophysics Data System (ADS)

    Choppali, Aiswarya

    Graphite-epoxy composites are being widely used in many aerospace and structural applications because of their properties: which include lighter weight, higher strength to weight ratio and a greater flexibility in design. However, the inherent anisotropy of these composites makes it difficult to machine them using conventional methods. To overcome the major issues that develop with conventional machining such as fiber pull out, delamination, heat generation and high tooling costs, an effort is herein made to study abrasive waterjet machining of composites. An abrasive waterjet is used to cut 1" thick graphite epoxy composites based on baseline data obtained from the cutting of ¼" thick material. The objective of this project is to study the surface roughness of the cut surface with a focus on demonstrating the benefits of using higher pressures for cutting composites. The effects of major cutting parameters: jet pressure, traverse speed, abrasive feed rate and cutting head size are studied at different levels. Statistical analysis of the experimental data provides an understanding of the effect of the process parameters on surface roughness. Additionally, the effect of these parameters on the taper angle of the cut is studied. The data is analyzed to obtain a set of process parameters that optimize the cutting of 1" thick graphite-epoxy composite. The statistical analysis is used to validate the experimental data. Costs involved in the cutting process are investigated in term of abrasive consumed to better understand and illustrate the practical benefits of using higher pressures. It is demonstrated that, as pressure increased, ultra-high pressure waterjets produced a better surface quality at a faster traverse rate with lower costs.

  16. TUBE TESTER

    DOEpatents

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

    1958-01-14

    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.

  17. Characterization of fine abrasive particles for optical fabrication

    NASA Astrophysics Data System (ADS)

    Funkenbusch, Paul D.; Zhou, Y. Y.; Takahashi, Toshio; Quesnel, David J.; Lambropoulos, John C.

    1995-08-01

    Material removal during fine grinding operations is accomplished primarily by the action of individual abrasive particles on the glass surface. The mechanical properties of the abrasive are therefore important. Unfortunately it is difficult to directly measure the mechanical response of abrasives once they reach the scale of approximately 10 microns. As a result mechanical properties of fine abrasives are sometimes characterized in terms of an empirical `friability', based on the response of the abrasive to crushing by a metal ball in a vial. In this paper we report on modeling/experiments designed to more precisely quantify the mechanical properties of fine abrasives and ultimately to relate them to the conditions experienced by bound particles during grinding. Experiments have been performed on various types and sizes of diamond abrasives. The response of the particles is a strong function of the loading conditions and can be tracked by changing the testing parameters. Diamond size is also found to play a critical role, with finer diamonds less susceptible to fracture. A micromechanical model from the literature is employed estimate the forces likely to be seen during testing. We are also developing dynamic models to better predict the forces experienced during `friability' testing as a function of the testing parameters.

  18. Method for forming an abrasive surface on a tool

    DOEpatents

    Seals, Roland D.; White, Rickey L.; Swindeman, Catherine J.; Kahl, W. Keith

    1999-01-01

    A method for fabricating a tool used in cutting, grinding and machining operations, is provided. The method is used to deposit a mixture comprising an abrasive material and a bonding material on a tool surface. The materials are propelled toward the receiving surface of the tool substrate using a thermal spray process. The thermal spray process melts the bonding material portion of the mixture, but not the abrasive material. Upon impacting the tool surface, the mixture or composition solidifies to form a hard abrasive tool coating.

  19. New Rock Abrasivity Test Method for Tool Life Assessments on Hard Rock Tunnel Boring: The Rolling Indentation Abrasion Test (RIAT)

    NASA Astrophysics Data System (ADS)

    Macias, F. J.; Dahl, F.; Bruland, A.

    2016-05-01

    The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and to evaluate the newly developed RIAT test method, a comprehensive laboratory testing programme including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.

  20. Effect of abrasive grit size on wear of manganese-zinc ferrite under three-body abrasion

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1987-01-01

    Wear experiments were conducted using replication electron microscopy and reflection electron diffraction to study abrasion and deformed layers produced in single-crystal Mn-Zn ferrites under three-body abrasion. The abrasion mechanism of Mn-Zn ferrite changes drastically with the size of abrasive grits. With 15-micron (1000-mesh) SiC grits, abrasion of Mn-Zn ferrite is due principally to brittle fracture; while with 4- and 2-micron (4000- and 6000-mesh) SiC grits, abrasion is due to plastic deformation and fracture. Both microcracking and plastic flow produce polycrystalline states on the wear surfaces of single-crystal Mn-Zn ferrites. Coefficient of wear, total thickness of the deformed layers, and surface roughness of the wear surfaces increase markedly with an increase in abrasive grit size. The total thicknesses of the deformed layers are 3 microns for the ferrite abraded by 15-micron SiC, 0.9 microns for the ferrite abraded by 4-micron SiC, and 0.8 microns for the ferrite abraded by 1-micron SiC.

  1. The interactions between attrition, abrasion and erosion in tooth wear.

    PubMed

    Shellis, R Peter; Addy, Martin

    2014-01-01

    Tooth wear is the result of three processes: abrasion (wear produced by interaction between teeth and other materials), attrition (wear through tooth-tooth contact) and erosion (dissolution of hard tissue by acidic substances). A further process (abfraction) might potentiate wear by abrasion and/or erosion. Knowledge of these tooth wear processes and their interactions is reviewed. Both clinical and experimental observations show that individual wear mechanisms rarely act alone but interact with each other. The most important interaction is the potentiation of abrasion by erosive damage to the dental hard tissues. This interaction seems to be the major factor in occlusal and cervical wear. The available evidence is insufficient to establish whether abfraction is an important contributor to tooth wear in vivo. Saliva can modulate erosive/abrasive tooth wear, especially through formation of pellicle, but cannot prevent it. © 2014 S. Karger AG, Basel.

  2. Interaction between attrition,abrasion and erosion in tooth wear.

    PubMed

    Addy, M; Shellis, R P

    2006-01-01

    Tooth wear is the result of three processes: abrasion (wear produced by interaction between teeth and other materials), attrition (wear through tooth-tooth contact) and erosion (dissolution of hard tissue by acidic substances). A further process (abfraction) might potentiate wear by abrasion and/or erosion. Both clinical and experimental observations show that individual wear mechanisms rarely act alone but interact with each other. The most important interaction is the potentiation of abrasion by erosive damage to the dental hard tissues. This interaction seems to be the major factor in occlusal and cervical wear. The available evidence seems insufficient to establish whether abfraction is an important contributor to tooth wear in vivo. Saliva can modulate erosive/abrasive tooth wear through formation of pellicle and by remineralisation but cannot prevent it.

  3. A Review on Parametric Analysis of Magnetic Abrasive Machining Process

    NASA Astrophysics Data System (ADS)

    Khattri, Krishna; Choudhary, Gulshan; Bhuyan, B. K.; Selokar, Ashish

    2018-03-01

    The magnetic abrasive machining (MAM) process is a highly developed unconventional machining process. It is frequently used in manufacturing industries for nanometer range surface finishing of workpiece with the help of Magnetic abrasive particles (MAPs) and magnetic force applied in the machining zone. It is precise and faster than conventional methods and able to produce defect free finished components. This paper provides a comprehensive review on the recent advancement of MAM process carried out by different researcher till date. The effect of different input parameters such as rotational speed of electromagnet, voltage, magnetic flux density, abrasive particles size and working gap on the performances of Material Removal Rate (MRR) and surface roughness (Ra) have been discussed. On the basis of review, it is observed that the rotational speed of electromagnet, voltage and mesh size of abrasive particles have significant impact on MAM process.

  4. Method of protecting surfaces from abrasion and abrasion resistant articles of manufacture

    DOEpatents

    Hirschfeld, T.B.

    1988-06-09

    Surfaces of fabricated structures are protected from damage by impacting particulates by a coating of hard material formed as a mass of thin flexible filaments having root ends secured to the surface and free portions which can flex and overlap to form a resilient cushioning mat which resembles hair or fur. The filamentary coating covers the underlying surface with hard abrasion resistance material while also being compliant and capable of local accommodation to particle impacts. The coating can also function as thermal and/or acoustical insulation and has a friction reducing effect. 11 figs.

  5. Surface Abrasive Torsion for Improved Mechanical Properties and Microstructure

    NASA Astrophysics Data System (ADS)

    Moon, Ji Hyun; Baek, Seung Mi; Lee, Seok Gyu; Yoon, Jae Ik; Lee, Sunghak; Kim, Hyoung Seop

    2018-05-01

    A novel process of discrete surface abrasion during simple torsion (ST), named "surface abrasive torsion (SAT)," is proposed to overcome the limitation of ST, i.e., insufficient strain for severe plastic deformation (SPD) due to cracks initiated on the surface, by removing the roughened surface region. The effect of SAT on delayed crack initiation was explained using finite element simulations. Larger shear deformation applicable to the specimen in SAT than ST was demonstrated experimentally.

  6. Effect of nanofillers' size on surface properties after toothbrush abrasion.

    PubMed

    Cavalcante, Larissa M; Masouras, Konstantinos; Watts, David C; Pimenta, Luiz A; Silikas, Nick

    2009-02-01

    To investigate the effect of filler-particle size of experimental and commercial resin composites, undergoing toothbrush abrasion, on three surface properties: surface roughness (SR), surface gloss (G) and color stability (CS). Four model (Ivoclar/Vivadent) and one commercial resin composite (Tokuyama) with varying filler-size from 100-1000 nm were examined. Six discs (10 mm x 2 mm) from each product were prepared and mechanically polished. The samples were then submitted to 20,000 brushing strokes in a toothbrush abrasion machine. SR parameters (Ra, Rt and RSm), G, and CS were measured before and after toothbrush abrasion. Changes in SR and G were analyzed by 2-way ANOVA, with Bonferroni post hoc test. CS values were submitted to one-way ANOVA and Bonferroni post hoc test (alpha=0.05). Initial G values ranged between 73-87 gloss units (GU) and were reduced after toothbrush abrasion to a range of 8-64 GU. Toothbrush abrasion resulted in significant modifications in SR and G amongst the materials tested, attributed to filler sizes. There was statistically significant difference in color (delta E* ranged from 0.38-0.88). Filler size did not affect color stability. Toothbrush abrasion resulted in rougher and matte surfaces for all materials tested. Although the individual differences in surface roughness among filler sizes were not always significant, the correlation showed a trend that larger filler sizes resulted in higher surface roughness after abrasion for the SR parameters Ra and Rt (r = 0.95; r = 0.93, respectively). RSm showed an increase after toothbrush abrasion for all resin composites, however no significant correlation was detected (r = 0.21).There was a significant correlation between G and Ra ratios (r = - 0.95).

  7. Dentifrice fluoride and abrasivity interplay on artificial caries lesions.

    PubMed

    Nassar, Hani M; Lippert, Frank; Eckert, George J; Hara, Anderson T

    2014-01-01

    Incipient caries lesions on smooth surfaces may be subjected to toothbrushing, potentially leading to remineralization and/or abrasive wear. The interplay of dentifrice abrasivity and fluoride on this process is largely unknown and was investigated on three artificially created lesions with different mineral content/distribution. 120 bovine enamel specimens were randomly allocated to 12 groups (n = 10), resulting from the association of (1) lesion type [methylcellulose acid gel (MeC); carboxymethylcellulose solution (CMC); hydroxyethylcellulose gel (HEC)], (2) slurry abrasive level [low (REA 4/ RDA 69); high (REA 7/RDA 208)], and (3) fluoride concentration [0/275 ppm (14.5 mM) F as NaF]. After lesion creation, specimens were brushed in an automated brushing machine with the test slurries (50 strokes 2×/day). Specimens were kept in artificial saliva in between brushings and overnight. Enamel surface loss (SL) was determined by optical profilometry after lesion creation, 1, 3 and 5 days. Two enamel sections (from baseline and post-brushing areas) were obtained and analyzed microradiographically. Data were analyzed by analysis of variance and Tukey's tests (α = 5%). Brushing with high-abrasive slurry caused more SL than brushing with low-abrasive slurry. For MeC and CMC lesions, fluoride had a protective effect on SL from day 3 on. Furthermore, for MeC and CMC, there was a significant mineral gain in the remaining lesions except when brushed with high-abrasive slurries and 0 ppm F. For HEC, a significant mineral gain took place when low-abrasive slurry was used with fluoride. The tested lesions responded differently to the toothbrushing procedures. Both slurry fluoride content and abrasivity directly impacted SL and mineral gain of enamel caries lesions.

  8. Analysis of Abrasive Blasting of DOP-26 Iridium Alloy

    SciTech Connect

    Ohriner, Evan Keith; Zhang, Wei; Ulrich, George B

    2012-01-01

    The effects of abrasive blasting on the surface geometry and microstructure of DOP-26 iridium alloy (Ir-0.3% W-0.006% Th 0.005% Al) have been investigated. Abrasive blasting has been used to control emissivity of components operating at elevated temperature. The effects of abrasive blasting conditions on surface morphology were investigated both experimentally and by numerical modeling. The simplified model, based on finite element analysis of a single angular particle impacting on Ir alloy disk, calculates the surface deformation and residual strain distribution. The experimental results and modeling results both indicate that the surface geometry is not sensitive to the abrasive blast processmore » conditions of nozzle pressure and standoff distance considered in this study. On the other hand, the modeling results suggest that the angularity of the abrasive particle has an important role in determining surface geometry, which in turn, affects the emissivity. Abrasive blasting causes localized surface strains and localized recrystallization, but it does not affect grain size following extended exposure at elevated temperature. The dependence of emissivity of the DOP-26 alloy on mean surface slope follows a similar trend to that reported for pure iridium.« less

  9. Rock Abrasion Tool Exhibits the Deep Red Pigment of Mars

    NASA Technical Reports Server (NTRS)

    2006-01-01

    During recent soil-brushing experiments, the rock abrasion tool on NASA's Mars Exploration Rover Spirit became covered with dust, as shown here. An abundance of iron oxide minerals in the dust gave the device a reddish-brown veneer. Investigators were using the rock abrasion tool to uncover successive layers of soil in an attempt to reveal near-surface stratigraphy. Afterward, remnant dirt clods were visible on both the bit and the brush of the tool. Designers of the rock abrasion tool at Honeybee Robotics and engineers at the Jet Propulsion Laboratory developed a plan to run the brush on the rock abrasion tool in reverse to dislodge the dirt and return the tool to normal operation. Subsequent communications with the rover revealed that the procedure is working and the rock abrasion tool remains healthy.

    Spirit acquired this approximately true-color image with the panoramic camera on the rover's 893rd sol, or Martian day (July 8, 2006). The image combines exposures taken through three of the camera's filters, centered on wavelengths of 750 nanometers, 530 nanometers, and 430 nanometers.

  10. The grain-size distribution of pyroclasts: Primary fragmentation, conduit sorting or abrasion?

    NASA Astrophysics Data System (ADS)

    Kueppers, U.; Schauroth, J.; Taddeucci, J.

    2013-12-01

    Explosive volcanic eruptions expel a mixture of pyroclasts and lithics. Pyroclasts, fragments of the juvenile magma, record the state of the magma at fragmentation in terms of porosity and crystallinity. The grain size distribution of pyroclasts is generally considered to be a direct consequence of the conditions at magma fragmentation that is mainly driven by gas overpressure in bubbles, high shear rates, contact with external water or a combination of these factors. Stress exerted by any of these processes will lead to brittle fragmentation by overcoming the magma's relaxation timescale. As a consequence, most pyroclasts exhibit angular shapes. Upon magma fragmentation, the gas pyroclast mixture is accelerated upwards and eventually ejected from the vent. The total grain size distribution deposited is a function of fragmentation conditions and transport related sorting. Porous pyroclasts are very susceptible to abrasion by particle-particle or particle-conduit wall interaction. Accordingly, pyroclastic fall deposits with angular clasts should proof a low particle abrasion upon contact to other surfaces. In an attempt to constrain the degree of particle interaction during conduit flow, monomodal batches of washed pyroclasts have been accelerated upwards by rapid decompression and subsequently investigated for their grain size distribution. In our set-up, we used a vertical cylindrical tube without surface roughness as conduit. We varied grain size (0.125-0.25; 0.5-1; 1-2 mm), porosity (0; 10; 30 %), gas-particle ratio (10 and 40%), conduit length (10 and 28 cm) and conduit diameter (2.5 and 6 cm). All ejected particles were collected after settling at the base of a 3.3 m high tank and sieved at one sieve size below starting size (half-Φ). Grain size reduction showed a positive correlation with starting grain size, porosity and overpressure at the vent. Although milling in a volcanic conduit may take place, porous pyroclasts are very likely to be a primary product

  11. Effect of occlusal calculus utilized as a potential "biological sealant" in special needs patients with gastric feeding tubes: a qualitative in vitro contrast to pit and fissure sealant restorations.

    PubMed

    Owens, Barry M; Sharp, Harry K; Fourmy, Emily E; Phebus, Jeffrey G

    2016-01-01

    The aim of this case report and in vitro investigation was to evaluate the marginal microleakage of intact occlusal calculus of primary molars extracted from a special needs patient who received nutrition via a gastric feeding tube. An adolescent with a history of developmental disturbance presented for routine dental care in a hospital facility. Prophylaxis was performed, and 2 mandibular permanent molars were restored. Five primary molars were extracted due to mobility and delayed retention. Heavy deposits of intact calculus were present on the occlusal surfaces of the primary teeth. The extracted teeth were immersed in methylene blue dye solution, invested in acrylic resin, sectioned into blocks, and photographed at 20× and 40× magnification. Previously photographed calculus-free molars with pit and fissure sealants were reviewed and served as contrasting "restorations." The occlusal calculus on the primary teeth extracted from the patient absorbed the dye, while the comparison teeth containing pit and fissure sealants exhibited varying degrees of marginal dye penetration (microleakage). No marginal microleakage was noted in the calculus specimens, indicating that this substrate may serve as a "natural" occlusal surface sealant and that its removal from occlusal surfaces during routine oral prophylaxis may be unnecessary.

  12. For patients with terminal chronic illness, does more face-to-face time with a healthcare provider decrease aggressive end-of-life (EOL) care such as ICU admission, feeding tube placement, CPR, or intubation?

    PubMed Central

    Seaberg, Preston; Hamm, Robert M.; McCarthy, Laine H.

    2016-01-01

    Clinical Question For patients with terminal chronic illness, does more face-to-face time with a healthcare provider decrease aggressive end-of-life (EOL) care such as ICU admission, feeding tube placement, CPR, or intubation? Answer Inconclusive. Existing evidence does not provide a conclusive answer to this particular question. While multiple prospective, randomized, controlled trials demonstrate an association between increased patient-provider contact time and decreased aggressive EOL care, interventions in those studies contain multiple confounding elements that preclude isolation of the time factor from the other elements in the interventions. There is a need for research focusing on physician-patient communication time and EOL care. Level of Evidence for the Answer A Search Terms Terminal care, palliative care, terminal illness, communication, patient-provider relations, time factors, life support care, resuscitation orders, enteral nutrition Inclusion Criteria Systematic reviews, meta-analyses, and comparative studies published between 2008 and the current date comparing EOL care or EOL care preferences of patients who spend more face-to-face time with a healthcare provider to those of patients who spend less face-to-face time with a healthcare provider. Exclusion Criteria Studies that do not report the primary outcome of interest (EOL care or EOL care preferences) or that do not measure discussion time or provide interventions that include face-to-face discussion. PMID:25796765

  13. Tubing misconnections: normalization of deviance.

    PubMed

    Simmons, Debora; Symes, Lene; Guenter, Peggi; Graves, Krisanne

    2011-06-01

    Accidental connection of an enteral system to an intravenous (IV) system frequently results in the death of the patient. Misconnections are commonly attributed to the presence of universal connectors found in the majority of patient care tubing systems. Universal connectors allow for tubing misconnections between physiologically incompatible systems. The purpose of this review of case studies of tubing misconnections and of current expert recommendations for safe tubing connections was to answer the following questions: In tubing connections that have the potential for misconnections between enteral and IV tubing, what are the threats to safety? What are patient outcomes following misconnections between enteral and IV tubing? What are the current recommendations for preventing misconnections between enteral and IV tubing? Following an extensive literature search and guided by 2 models of threats and errors, the authors analyzed case studies and expert opinions to identify technical, organizational, and human errors; patient-related threats; patient outcomes; and recommendations. A total of 116 case studies were found in 34 publications. Each involved misconnections of tubes carrying feedings, intended for enteral routes, to IV lines. Overwhelmingly, the recommendations were for redesign to eliminate universal connectors and prevent misconnections. Other recommendations were made, but the analysis indicates they would not prevent all misconnections. This review of the published case studies and current expert recommendations supports a redesign of connectors to ensure incompatibility between enteral and IV systems. Despite the cumulative evidence, little progress has been made to safeguard patients from tubing misconnections.

  14. Prepolishing on a CNC platform with bound abrasive contour tools

    NASA Astrophysics Data System (ADS)

    Schoeffler, Adrienne E.; Gregg, Leslie L.; Schoen, John M.; Fess, Edward M.; Hakiel, Michael; Jacobs, Stephen D.

    2003-05-01

    Deterministic microgrinding (DMG) of optical glasses and ceramics is the commercial manufacturing process of choice to shape glass surfaces prior to final finishing. This process employs rigid bound matrix diamond tooling resulting in surface roughness values of 3-5μm peak to valley and 100-400nm rms, as well as mid-spatial frequency tool marks that require subsequent removal in secondary finishing steps. The ability to pre-polish optical surfaces within the grinding platform would reduce final finishing process times. Bound abrasive contour wheels containing cerium oxide, alumina or zirconia abrasives were constructed with an epoxy matrix. The effects of abrasive type, composition, and erosion promoters were examined for tool hardness (Shore D), and tested with commercial optical glasses in an Optipro CNC grinding platform. Metrology protocols were developed to examine tool wear and subsequent surface roughness. Work is directed to demonstrating effective material removal, improved surface roughness and cutter mark removal.

  15. Abrasion of Candidate Spacesuit Fabrics by Simulated Lunar Dust

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Meador, Mary Ann; Rogers, Kerry J.; Sheehy, Brennan H.

    2009-01-01

    A protocol has been developed that produced the type of lunar soil abrasion damage observed on Apollo spacesuits. This protocol was then applied to four materials (Kevlar (DuPont), Vectran (Kuraray Co., Ltd.), Orthofabric, and Tyvek (DuPont)) that are candidates for advanced spacesuits. Three of the four new candidate fabrics (all but Vectran) were effective at keeping the dust from penetrating to layers beneath. In the cases of Kevlar and Orthofabric this was accomplished by the addition of a silicone layer. In the case of Tyvek, the paper structure was dense enough to block dust transport. The least abrasive damage was suffered by the Tyvek. This was thought to be due in large part to its non-woven paper structure. The woven structures were all abraded where the top of the weave was struck by the abrasive. Of these, the Orthofabric suffered the least wear, with both Vectran and Kevlar suffering considerably more extensive filament breakage.

  16. Feasibility Study on Cutting HTPB Propellants with Abrasive Water Jet

    NASA Astrophysics Data System (ADS)

    Jiang, Dayong; Bai, Yun

    2018-01-01

    Abrasive water jet is used to carry out the experiment research on cutting HTPB propellants with three components, which will provide technical support for the engineering treatment of waste rocket motor. Based on the reliability theory and related scientific research results, the safety and efficiency of cutting sensitive HTPB propellants by abrasive water jet were experimentally studied. The results show that the safety reliability is not less than 99.52% at 90% confidence level, so the safety is adequately ensured. The cooling and anti-friction effect of high-speed water jet is the decisive factor to suppress the detonation of HTPB propellant. Compared with pure water jet, cutting efficiency was increased by 5% - 87%. The study shows that abrasive water jets meet the practical use for cutting HTPB propellants.

  17. Aeolian abrasion on Venus: Preliminary results from the Venus simulator

    NASA Technical Reports Server (NTRS)

    Marshall, J. R.; Greeley, Ronald; Tucker, D. W.; Pollack, J. B.

    1987-01-01

    The role of atmospheric pressure on aeolian abrasion was examined in the Venus Simulator with a constant temperature of 737 K. Both the rock target and the impactor were fine-grained basalt. The impactor was a 3 mm diameter angular particle chosen to represent a size of material that is entrainable by the dense Venusian atmosphere and potentially abrasive by virtue of its mass. It was projected at the target 10 to the 5 power times at a velocity of 0.7 m/s. The impactor showed a weight loss of approximately 1.2 x 10 to the -9 power gm per impact with the attrition occurring only at the edges. Results from scanning electron microscope analysis, profilometry, and weight measurement are summarized. It is concluded that particles can incur abrasion at Venusian temperatures even with low impact velocities expected for Venus.

  18. Study of Dominant Factors Affecting Cerchar Abrasivity Index

    NASA Astrophysics Data System (ADS)

    Rostami, Jamal; Ghasemi, Amireza; Alavi Gharahbagh, Ehsan; Dogruoz, Cihan; Dahl, Filip

    2014-09-01

    The Cerchar abrasion index is commonly used to represent rock abrasion for estimation of bit life and wear in various mining and tunneling applications. Although the test is simple and fast, there are some discrepancies in the test results related to the equipment used, condition of the rock surface, operator skills, and procedures used in conducting and measuring the wear surface. This paper focuses on the background of the test and examines the influence of various parameters on Cerchar testing including pin hardness, surface condition of specimens, petrographical and geomechanical properties, test speed, applied load, and method of measuring wear surface. Results of Cerchar tests on a set of rock specimens performed at different laboratories are presented to examine repeatability of the tests. In addition, the preliminary results of testing with a new device as a potential alternative testing system for rock abrasivity measurement are discussed.

  19. Field evidence of two-phase abrasion process

    NASA Astrophysics Data System (ADS)

    Miller, K. L.; Szabo, T.; Jerolmack, D. J.; Domokos, G.

    2013-12-01

    The rounded shape of river rocks is clear evidence that abrasion due to bed load transport is a significant agent for mass loss. Its contribution to downstream fining, however, is typically assumed to be negligible - as diminution trends may be explained solely by size-selective transport. A recent theory has predicted that pebble abrasion occurs in two well separated phases: in Phase 1, an intially-polyhedral pebble rounds to the shape of an inscribed ellipsoid without any change in axis dimensions; in Phase II, axis dimensions are slowly reduced. Importantly, Phase I abrasion means that an initially-blocky pebble may lose up to half its mass without any apparent change in 'size', which is only measured as the length of a single pebble axis by most field researchers. We hypothesize that field studies have significantly underestimated the importance of abrasion because they do not quantify pebble shape, and we set out to demonstrate that two-phase abrasion occurs in a natural stream. Our study examines downstream trends in pebble size and shape along a 10-km stretch of the Rio Mameyes within the Luquillo Critical Zone observatory, where volcaniclastic cobbles and boulders are transported by bed load at slopes up to 10%. The upper reaches of the stream consist of alluviated bedrock valleys that preclude sediment storage and thus minimize size-selective transport, which allows us to isolate the effects of abrasion. The lower 5 km is an alluvial river in which size-selective transport becomes operative. We quantified the shape and size of thousands of pebbles along the profile using hand and image-based techniques. The data provide the first field validation of two-phase abrasion; in the bedrock reaches, pebbles clearly evolve toward ellipsoids without any significant change in axis dimensions (rounding), while in the lower reaches pebbles slowly reduce their axis dimensions with little or no change in roundness. Results also show that shape metrics determined from

  20. An Ex-vivo Shear and tensile bond strengths of orthodontic molar tubes bonded using different techniques

    PubMed Central

    Alwahadni, Ahed

    2017-01-01

    Background Molar bonding procedures need continuous improvement to be widely accepted clinically and eventually replace molar bands. Material and Methods The purpose of this study was to determine the effects of enamel micro-abrasion and silane coating of the base of molar tubes on shear and tensile bond strengths of orthodontic molar tubes. A total of 200 third molars were randomly allocated into five groups of 40 teeth as follows: group 1: molar tubes bonded to etched teeth (37% phosphoric acid gel; control group); group 2: molar tubes bonded to etched teeth (37% phosphoric acid) with the addition of silane to the base of molar tubes; group 3: molar tubes bonded to teeth pre-treated with 18% hydrochloric acid and pumice (micro-abrasion); group 4: molar tubes bonded to teeth pre-treated with microabrasion with the addition of silane to the base of molar tubes; group 5: molar tubes bonded to teeth pre-treated with microabrasion before conventional acid etching combined with the addition of silane to the base of molar tubes. The bond strength testing was performed using a computer control electromechanical universal testing machine. Results The highest mean shear and tensile bond strengths were recorded in group 5 (13.81±2.54MPa and 13.97±2.29 MPa, respectively). Micro-abrasion alone (group 3) and the combination of enamel micro-abrasion and the addition of silane (group 4) produced bond strength values comparable to the control. Conclusions Enamel surface pre-treatment (micro abrasion) before conventional acid etching combined with the addition of silane to the base of the molar tube produced the highest bond strengths among all tested groups. Key words:Molar, shear strength, tensile strength, orthodontic appliances. PMID:28298990

  1. An Ex-vivo Shear and tensile bond strengths of orthodontic molar tubes bonded using different techniques.

    PubMed

    Abu-Alhaija, Elham; Jaradat, Mohammad; Alwahadni, Ahed

    2017-03-01

    Molar bonding procedures need continuous improvement to be widely accepted clinically and eventually replace molar bands. The purpose of this study was to determine the effects of enamel micro-abrasion and silane coating of the base of molar tubes on shear and tensile bond strengths of orthodontic molar tubes. A total of 200 third molars were randomly allocated into five groups of 40 teeth as follows: group 1: molar tubes bonded to etched teeth (37% phosphoric acid gel; control group); group 2: molar tubes bonded to etched teeth (37% phosphoric acid) with the addition of silane to the base of molar tubes; group 3: molar tubes bonded to teeth pre-treated with 18% hydrochloric acid and pumice (micro-abrasion); group 4: molar tubes bonded to teeth pre-treated with microabrasion with the addition of silane to the base of molar tubes; group 5: molar tubes bonded to teeth pre-treated with microabrasion before conventional acid etching combined with the addition of silane to the base of molar tubes. The bond strength testing was performed using a computer control electromechanical universal testing machine. The highest mean shear and tensile bond strengths were recorded in group 5 (13.81±2.54MPa and 13.97±2.29 MPa, respectively). Micro-abrasion alone (group 3) and the combination of enamel micro-abrasion and the addition of silane (group 4) produced bond strength values comparable to the control. Enamel surface pre-treatment (micro abrasion) before conventional acid etching combined with the addition of silane to the base of the molar tube produced the highest bond strengths among all tested groups. Key words: Molar, shear strength, tensile strength, orthodontic appliances.

  2. PEG tubes: dealing with complications.

    PubMed

    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.

  3. Exposure to crystalline silica in abrasive blasting operations where silica and non-silica abrasives are used.

    PubMed

    Radnoff, Diane L; Kutz, Michelle K

    2014-01-01

    Exposure to respirable crystalline silica is a hazard common to many industries in Alberta but particularly so in abrasive blasting. Alberta occupational health and safety legislation requires the consideration of silica substitutes when conducting abrasive blasting, where reasonably practicable. In this study, exposure to crystalline silica during abrasive blasting was evaluated when both silica and non-silica products were used. The crystalline silica content of non-silica abrasives was also measured. The facilities evaluated were preparing metal products for the application of coatings, so the substrate should not have had a significant contribution to worker exposure to crystalline silica. The occupational sampling results indicate that two-thirds of the workers assessed were potentially over-exposed to respirable crystalline silica. About one-third of the measurements over the exposure limit were at the work sites using silica substitutes at the time of the assessment. The use of the silica substitute, by itself, did not appear to have a large effect on the mean airborne exposure levels. There are a number of factors that may contribute to over-exposures, including the isolation of the blasting area, housekeeping, and inappropriate use of respiratory protective equipment. However, the non-silica abrasives themselves also contain silica. Bulk analysis results for non-silica abrasives commercially available in Alberta indicate that many contain crystalline silica above the legislated disclosure limit of 0.1% weight of silica per weight of product (w/w) and this information may not be accurately disclosed on the material safety data sheet for the product. The employer may still have to evaluate the potential for exposure to crystalline silica at their work site, even when silica substitutes are used. Limited tests on recycled non-silica abrasive indicated that the silica content had increased. Further study is required to evaluate the impact of product recycling

  4. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain the spindle speed at safe levels under all conditions of normal operation. (b) Guarding. (1) Grinding machines..., nut, and outer flange may be exposed on machines designed as portable saws. (c) Use of abrasive wheels...

  5. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain the spindle speed at safe levels under all conditions of normal operation. (b) Guarding. (1) Grinding machines..., nut, and outer flange may be exposed on machines designed as portable saws. (c) Use of abrasive wheels...

  6. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain the spindle speed at safe levels under all conditions of normal operation. (b) Guarding. (1) Grinding machines..., nut, and outer flange may be exposed on machines designed as portable saws. (c) Use of abrasive wheels...

  7. Propelled abrasive grit for weed control in organic silage corn

    USDA-ARS?s Scientific Manuscript database

    Weed management in organic farming requires many strategies to accomplish acceptable control and maintain crop yields. This two-year field study used air propelled abrasive grit for in-row weed control in a silage corn system. Corncob grit was applied as a single application at corn vegetative growt...

  8. Review of Artificial Abrasion Test Methods for PV Module Technology

    SciTech Connect

    Miller, David C.; Muller, Matt T.; Simpson, Lin J.

    This review is intended to identify the method or methods--and the basic details of those methods--that might be used to develop an artificial abrasion test. Methods used in the PV literature were compared with their closest implementation in existing standards. Also, meetings of the International PV Quality Assurance Task Force Task Group 12-3 (TG12-3, which is concerned with coated glass) were used to identify established test methods. Feedback from the group, which included many of the authors from the PV literature, included insights not explored within the literature itself. The combined experience and examples from the literature are intended tomore » provide an assessment of the present industry practices and an informed path forward. Recommendations toward artificial abrasion test methods are then identified based on the experiences in the literature and feedback from the PV community. The review here is strictly focused on abrasion. Assessment methods, including optical performance (e.g., transmittance or reflectance), surface energy, and verification of chemical composition were not examined. Methods of artificially soiling PV modules or other specimens were not examined. The weathering of artificial or naturally soiled specimens (which may ultimately include combined temperature and humidity, thermal cycling and ultraviolet light) were also not examined. A sense of the purpose or application of an abrasion test method within the PV industry should, however, be evident from the literature.« less

  9. Effect of air abrasion and polishing on primary molar fissures.

    PubMed

    Lenzi, T L; Menezes, L B R; Soares, F Z M; Rocha, R O

    2013-04-01

    To evaluate the effect of air abrasion and polishing on primary molar fissures under light microscopy. 15 exfoliated primary second molars were longitudinally sectioned and photographed under a stereomicroscope (40×; baseline evaluation). Sections were then randomly allocated into one of the two groups (n = 15) and treated by either air abrasion (aluminium oxide jet) or air polishing (sodium bicarbonate jet) for 30 s. After treatment, sections were washed with an air/water spray, dried with absorbent paper, and photographed as previously described (final evaluation). Baseline and final morphology were compared by two blinded examiners who evaluated changes in the width and depth of fissures. The percentage of changed fissures was analysed, and the two treatments were compared using the Mann-Whitney test (α = 0.01). Both air systems resulted in fissure changes in most (93.3 %) of the sections. No significant differences in fissure width changes were found between treatments, but when changes in fissure depth were evaluated, air polishing was found to be less damaging than air abrasion (p < 0.01). Air abrasion and polishing cause changes to the anatomical configuration of occlusal fissures of primary molars.

  10. Assessment of Rail Seat Abrasion Patterns and Environment

    DOT National Transportation Integrated Search

    2012-05-01

    Rail seat abrasion (RSA) of concrete ties is manifested by the loss of material under the rail seat area and, in extreme cases, results in loss of rail clip holding power, reverse rail cant, and gauge widening. RSA was measured in several curves on t...

  11. 9 CFR 311.14 - Abrasions, bruises, abscesses, pus, etc.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Abrasions, bruises, abscesses, pus, etc. 311.14 Section 311.14 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... AND VOLUNTARY INSPECTION AND CERTIFICATION DISPOSAL OF DISEASED OR OTHERWISE ADULTERATED CARCASSES AND...

  12. Rock Abrasion Tool Exhibits the Deep Red Pigment of Mars

    NASA Image and Video Library

    2006-07-21

    This image shows the round, metallic working end of the rock abrasion tool at the end of a metallic cylinder. The flat grinding face, attached brush, and much of the smooth, metallic exterior of cylinder are covered with a deep reddish-brown layer of dust

  13. [Brushing abrasion of the enamel surface after erosion].

    PubMed

    Lipei, Chen; Xiangke, Ci; Xiaoyan, Ou

    2017-08-01

    Objective A study was conducted to compare the effect of different enamel remineralization periods after erosion on the depth of brushing abrasion. Methods Ten volunteers were selected for a 4-day experiment. A total of 60 enamels were randomly assigned into six groups (A-F) and placed in intraoral palatal devices. On the first day, the palatal devices were placed in oral cavity (24 h) . On the following three days, brushing experiments were performed extraorally, two times per day. The specific experimental method of brushing follows these next steps. First, the group F specimens were covered with a film of wax, and then acid etched for 2 min. Subsequently, the film of wax was detached. The groups from A to D were brushed after remineralization at the following time intervals: group A, 0 min; group B, 20 min; group C, 40 min; group D, 60 min. Erosion and remineralization were performed on group E, but without brushing. Remineralization was performed on group F, but without acid etching and brushing. The depth of enamel abrasion was determined by a mechanical profilometer. The surface morphology of the enamel blocks was observed using a scanning electron microscope. Results 1) The depth of abrasion was different in varied enamel remineralization time after acid etching. The statistical significant differences between groups were as follows. 2) When the time of enamel remineralization after acid etching was short, the surface depression in the electron microscope was deep, and the surface morphology was rough. Conclusion Brushing immediately after acid etching would cause much serious abrasion to the enamel surface. Brushing after 60 min can effectively reduce the abrasion of acid etching enamel.

  14. Study on design of light-weight super-abrasive wheel

    NASA Astrophysics Data System (ADS)

    Nohara, K.; Yanagihara, K.; Ogawa, M.

    2018-01-01

    Fixed-abrasive tool, also called a grinding wheel, is produced by furnacing abrasive compound which contains abrasive grains and binding powder such as vitrified materials or resins. Fixed-abrasive tool is installed on spindle of grinding machine. And it is given 1,800-2,000 min-1 of spindle rotation for the usage. The centrifugal fracture of the compound of fixed- abrasive tool is one of the careful respects in designing. In recent years, however, super-abrasive wheel as a fixed-abrasive tool has been developed and applied widely. One of the most characteristic respects is that metal is applied for the body of grinding-wheel. The strength to hold abrasive grain and the rigidity of wheel become stronger than those of general grinding wheel, also the lifespan of fixed-abrasive tool becomes longer. The weight of fixed-abrasive tool, however, becomes heavier. Therefore, when the super-abrasive wheel is used, the power consumption of spindle motor becomes larger. It also becomes difficult for the grinding-wheel to respond to sudden acceleration or deceleration. Thus, in order to reduce power consumption in grinding and to obtain quicker frequency response of super-abrasive wheel, the new wheel design is proposed. The design accomplishes 46% weight reduction. Acceleration that is one second quicker than that of conventional grinding wheel is obtained.

  15. Advanced Illness: Feeding Tubes and Ventilators

    MedlinePlus

    ... stage Alzheimer's disease. For many, this is a quality of life issue, and they would prefer to not to ... supplements, use of a ventilator is also a quality of life decision. For some people, staying alive under these ...

  16. Feeding Methods at Discharge Predict Long-term Feeding and Neurodevelopmental Outcomes in Preterm Infants Referred for Gastrostomy Evaluation

    PubMed Central

    Jadcherla, Sudarshan; Khot, Tanvi; Moore, Rebecca; Malkar, Manish; Gulati, Ish; Slaughter, Jonathan

    2017-01-01

    Objective To test the hypothesis that oral (PO) feeding at first neonatal intensive care unit (NICU) discharge is associated with less neurodevelopmental impairment and better feeding milestones, as compared with discharge with a gastrostomy tube (g-tube). Study design We studied outcomes for a retrospective cohort of 194 neonates < 37 weeks gestation referred for evaluation and management of feeding difficulties between July 2006–July 2012. Discharge milestones, length of hospitalization, and Bayley Scales of Infant Development scores at 18–24 months were examined. Chi-Square, Mann-Whitney U, or t-tests and multivariable logistic regression models were used. Results 60% (n=117) of infants were discharged on PO feedings; of these, 96% remained PO-fed at 1-year. The remaining 40% (n=77) were discharged on g-tube feedings; of these, 31 (40%) remained g-tube dependent, 17 (22%) became PO-fed, and 29 (38%) were on PO and g-tube feedings at one year. Infants discharged on a g-tube had lower cognitive (p<0.01), communication (p=0.03), and motor (p<0.01) composite scores. The presence of a g-tube, younger gestation, bronchopulmonary dysplasia, or intraventricular hemorrhage was significantly associated with neurodevelopmental delay. Conclusions For infants referred for feeding concerns, g-tube evaluations and feeding management, the majority did not require a g-tube. Full PO feeding at first NICU discharge was associated with superior feeding milestones and less long-term neurodevelopmental impairment, relative to full or partial g-tube feeding. Evaluation and feeding management before and after g-tube placement may improve long-term feeding and neurodevelopmental outcomes. PMID:27939123

  17. Solid Lubrication Fundamentals and Applications. Chapter 5; Abrasion: Plowing and Cutting

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    2001-01-01

    Chapter 5 discusses abrasion, a common wear phenomenon of great economic importance. It has been estimated that 50% of the wear encountered in industry is due to abrasion. Also, it is the mechanism involved in the finishing of many surfaces. Experiments are described to help in understanding the complex abrasion process and in predicting friction and wear behavior in plowing and/or cutting. These experimental modelings and measurements used a single spherical pin (asperity) and a single wedge pin (asperity). Other two-body and three-body abrasion studies used hard abrasive particles.

  18. Effect of cleaning methods after reduced-pressure air abrasion on bonding to zirconia ceramic.

    PubMed

    Attia, Ahmed; Kern, Matthias

    2011-12-01

    To evaluate in vitro the influence of different cleaning methods after low-pressure air abrasion on the bond strength of a phosphate monomer-containing luting resin to zirconia ceramic. A total of 112 zirconia ceramic disks were divided into 7 groups (n = 16). In the test groups, disks were air abraded at low pressure (L) 0.05 MPa using 50-μm alumina particles. Prior to bonding, the disks were ultrasonically (U) cleaned either in isopropanol alcohol (AC), hydrofluoric acid (HF), demineralized water (DW), or tap water (TW), or they were used without ultrasonic cleaning. Disks air abraded at a high (H) pressure of 0.25 MPa and cleaned ultrasonically in isopropanol served as positive control; original (O) milled disks used without air abrasion served as the negative control group. Plexiglas tubes filled with composite resin were bonded with the adhesive luting resin Panavia 21 to the ceramic disks. Prior to testing tensile bond strength (TBS), each main group was further subdivided into 2 subgroups (n=8) which were stored in distilled water either at 37°C for 3 days or for 30 days with 7500 thermal cycles. Statistical analyses were conducted with two- and one-way analyses of variance (ANOVA) and Tukey's HSD test. Initial tensile bond strength (TBS) ranged from 32.6 to 42.8 MPa. After 30 days storage in water with thermocycling, TBS ranged from 21.9 to 36.3 MPa. Storage in water and thermocycling significantly decreased the TBS of test groups which were not air abraded (p = 0.05) or which were air abraded but cleaned in tap water (p = 0.002), but not the TBS of the other groups (p > 0.05). Also, the TBS of air-abraded groups were significantly higher than the TBS of the original milled (p < 0.01). Cleaning procedures did not significantly affect TBS either after 3 days or 30 days storage in water and thermocycling (p > 0.05). Air abrasion at 0.05 MPa and ultrasonic cleaning are important factors for improving bonding to zirconia ceramic.

  19. The efficacy of mechanical abrasion and talc slurry as methods of pleurodesis in normal dogs.

    PubMed

    Jerram, R M; Fossum, T W; Berridge, B R; Steinheimer, D N; Slater, M R

    1999-01-01

    To determine the efficacy of mechanical abrasion and talc slurry as methods for pleurodesis in normal dogs. Experimental study. Ten normal beagle dogs. Group I dogs had mechanical abrasion (MA) of the pulmonary and costal pleurae performed in one hemithorax with a dry gauze sponge with a median sternotomy approach. Group II dogs had 100 mL of a 1 g talc slurry (TS) administered into one hemithorax through a tube thoracostomy. Administration of the TS was visualized by using video thoracoscopy. All dogs were evaluated at 2, 10, 20, and 30 days postoperatively by means of thoracic radiography and ultrasonographic thoracic wall measurement. The dogs were euthanatized 30 days postoperatively and a gross necropsy was performed. Hemithoraces were assigned a pleurodesis score (0-4) and an obliteration grade (0-6). Tissues were collected for histopathologic examination of pulmonary pleura, costal pleura, and pleural adhesions. Pulmonary and costal pleurae were graded for the degree of fibrosis (0-4). Obliteration grade and costal pleural fibrosis score were significantly higher for the treated sides in the MA dogs compared with the TS dogs. MA Dogs: Mechanical abrasion dogs had pleurodesis, obliteration, and pleural fibrosis scores that were greater on the treated side than the untreated side, however, the differences were not statistically significant. Only two MA dogs had firm adhesion of the pulmonary pleura to the costal pleura in portions of the cranial and middle lung lobes in the treated hemithorax. Thoracic wall surface area covered with adhesions was 15% and 21% in each of these two dogs. The median pulmonary pleural fibrosis score of all MA dogs for the treated hemithorax was 3 compared to 0 on the untreated side. TS Dogs: There was no statistical difference for pleurodesis scores and obliteration grades between the treated and untreated sides. No dogs showed evidence of pulmonary to costal pleural adhesions. Histopathology showed talc crossover into the

  20. Protective tubes for sodium heated water tubes

    DOEpatents

    Essebaggers, Jan

    1979-01-01

    A heat exchanger in which water tubes are heated by liquid sodium which minimizes the results of accidental contact between the water and the sodium caused by failure of one or more of the water tubes. A cylindrical protective tube envelopes each water tube and the sodium flows axially in the annular spaces between the protective tubes and the water tubes.

  1. Multiple tube premixing device

    DOEpatents

    Uhm, Jong Ho; Naidu, Balachandar; Ziminksy, Willy Steve; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin; Stevenson, Christian; Felling, David

    2013-08-13

    The present application provides a premixer for a combustor. The premixer may include a fuel plenum with a number of fuel tubes and a burner tube with a number of air tubes. The fuel tubes extend about the air tubes.

  2. Multiple tube premixing device

    DOEpatents

    Uhm, Jong Ho; Varatharajan, Balachandar; Ziminsky, Willy Steve; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin; Stevenson, Christian; Felling, David

    2012-12-11

    The present application provides a premixer for a combustor. The premixer may include a fuel plenum with a number of fuel tubes and a burner tube with a number of air tubes. The fuel tubes extend about the air tubes.

  3. Self inflicted corneal abrasions due to delusional parasitosis

    PubMed Central

    Meraj, Adeel; Din, Amad U; Larsen, Lynn; Liskow, Barry I

    2011-01-01

    The authors report a case of self inflicted bilateral corneal abrasions and skin damage due to ophthalmic and cutaneous delusional parasitosis. A male in his 50s presented with a 10 year history of believing that parasites were colonizing his skin and biting into his skin and eyes. The patient had received extensive medical evaluations that found no evidence that symptoms were due to a medical cause. He was persistent in his belief and had induced bilateral corneal abrasions and skin damage by using heat lamps and hair dryers in an attempt to disinfect his body. The patient was treated with olanzapine along with treatment for his skin and eyes. His delusional belief system persisted but no further damage to his eyes and skin was noted on initial follow-up. PMID:22689836

  4. The worn dentition--pathognomonic patterns of abrasion and erosion.

    PubMed

    Abrahamsen, Thomas C

    2005-01-01

    Historically, the dental literature has revealed various causes of tooth wear, yet it has failed to provide a conclusive method of differentiation and diagnosis of the condition. The categories of tooth wear encountered most commonly in dental practice are abrasion and erosion. The major causes of wear from abrasion are bruxism and toothpaste abuse, and the major causes of wear from erosion are regurgitation, coke-swishing and fruit-mulling. Through in-depth clinical study of these causes, this paper provides a diagnostic system that will enable dental professionals to determine and differentiate the exact aetiology of the worn dentition simply by the recognition of the pathognomonic wear patterns on diagnostic casts, which are based upon the position and quantity of the non-carious loss of tooth structure.

  5. Design of a new abrasive slurry jet generator

    NASA Astrophysics Data System (ADS)

    Wang, F. C.; Shi, L. L.; Guo, C. W.

    2017-12-01

    With the advantages of a low system working pressure, good jet convergence and high cutting quality, abrasive slurry jet (ASJ) has broad application prospects in material cutting and equipment cleaning. Considering that the generator plays a crucial role in ASJ system, the paper designed a new type ASJ generator using an electric oil pump, a separate plunger cylinder, and a spring energized seal. According to the determining of structure shape, size and seal type, a new ASJ generator has been manufactured out and tested by a series of experiments. The new generator separates the abrasive slurry from the dynamic hydraulic oil, which can improve the service life of the ASJ system. And the new ASJ system can reach 40 MPa and has good performance in jet convergence, which deserves to popularization and application in materials machining.

  6. Abrasion resistance of muscovite in aeolian and subaqueous transport experiments

    NASA Astrophysics Data System (ADS)

    Anderson, Calvin J.; Struble, Alexander; Whitmore, John H.

    2017-02-01

    Complementary aeolian and subaqueous transport experiments showed a trend in muscovite abrasion that may be useful for identifying ancient sandstones as aeolian or subaqueous in origin. We found that our experimental aeolian processes pulverized the micas quickly, while our subaqueous processes did not. In a pair of abrasion resistance experiments conducted with micaceous quartz sand, it was found that large muscovite grains were (1) reduced by aeolian processes to less than 500 μm in just 4 days, and (2) preserved by subaqueous processes to 610 ± 90 μm even after 356 days. At 20 days of aeolian transport no loose micas could be found even under the microscope, but after a year of subaqueous transport loose muscovite grains could still be seen with the naked eye. Thus, the occurrence and character of micas in a sandstone, particularly muscovite, may be helpful in determining the ancient depositional process.

  7. Wheel Abrasion Experiment Metals Selection for Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Fatemi, Navid S.; Wilt, David M.; Ferguson, Dale C.; Hoffman, Richard; Hill, Maria M.; Kaloyeros, Alain E.

    1996-01-01

    A series of metals was examined for suitability for the Wheel Abrasion Experiment, one of ten microrover experiments of the Mars Pathfinder Mission. The seven candidate metals were: Ag, Al, Au, Cu, Ni, Pt, and W. Thin films of candidate metals from 0.1 to 1.0 micrometer thick were deposited on black anodized aluminum coupons by e-beam and resistive evaporation and chemical vapor deposition. Optical, corrosion, abrasion, and adhesion criteria were used to select Al, Ni, and Pt. A description is given of the deposition and testing of thin films, followed by a presentation of experimental data and a brief discussion of follow-on testing and flight qualification.

  8. Investigation of wear resistance of polyurethanes in abrasive soil mass

    NASA Astrophysics Data System (ADS)

    Napiórkowski, Jerzy; Ligier, Krzysztof

    2018-04-01

    This paper presents a comparative study of polyurethane wear in different abrasive soil masses. Two types of polyurethanes of various chemical compositions and untreated 38GSA steel were tested, the latter being used as a reference standard. The study was conducted in natural soil mass at a "rotating bowl" stand. Relative wear resistance was determined from measurements of mass wear for the materials under study. The condition of the surface of the materials under wear test was analysed.

  9. Adhesive and abrasive wear mechanisms in ion implanted metals

    NASA Astrophysics Data System (ADS)

    Dearnaley, G.

    1985-03-01

    The distinction between adhesive and abrasive wear processes was introduced originally by Burwell during the nineteen-fifties, though some authors prefer to classify wear according to whether it is mild or severe. It is argued here that, on the basis of the performance of a variety of ion implanted metal surfaces, exposed to different modes of wear, the Burwell distinction is a valid one which, moreover, enables us to predict under which circumstances a given treatment will perform well. It is shown that, because wear rates under abrasive conditions are very sensitive to the ratio of the hardness of the surface to that of the abrasive particles, large increases in working life are attainable as a result of ion implantation. Under adhesive wear conditions, the wear rate appears to fall inversely as the hardness increases, and it is advantageous to implant species which will create and retain a hard surface oxide or other continuous film in order to reduce metal-metal contact. By the appropriate combination of physico-chemical changes in an implanted layer it has been possible to reduce wear rates by up to three orders of magnitude. Such rates compensate for the shallow depths achievable by ion implantation.

  10. Surface characterization of current composites after toothbrush abrasion.

    PubMed

    Takahashi, Rena; Jin, Jian; Nikaido, Toru; Tagami, Junji; Hickel, Reinhard; Kunzelmann, Karl-Heinz

    2013-01-01

    The present study was designed to evaluate the surface roughness and the gloss of current composites before and after toothbrush abrasion. We assessed forty dimensionally standardized composite specimens (n=8/group) from five composites: two nanohybrids (i. e., IPS Empress Direct Enamel and IPS Empress Direct Dentin), two microhybrids (i. e., Clearfil AP-X and Filtek Z250) and one organically modified ceramics (Admira). All of the specimens were polished with 4000-grid silicon carbide papers. Surface roughness was measured with a profilometer and gloss was measured with a glossmeter before and after powered toothbrush abrasion with a 1:1 slurry (dentifrice/tap water) at 12,000 strokes in a toothbrush simulator. There was a significant increase in the surface roughness and a reduction in gloss after toothbrush abrasion in all of the composites except Clearfil AP-X (p<0.05). Simple regression analysis showed that there was not an association between the surface roughness and the gloss (R(2)=0.191, p<0.001).

  11. The role of erosion, abrasion and attrition in tooth wear.

    PubMed

    Barbour, Michele E; Rees, Gareth D

    2006-01-01

    There is increasing clinical awareness of erosion of enamel and dentine by dietary acids and the consequent increased susceptibility to physical wear. Enamel erosion is characterized by acid-mediated surface softening that, if unchecked, will progress to irreversible loss of surface tissue, potentially exposing the underlying dentine. In comparison, dentine erosion is less well understood as the composition and microstructure are more heterogeneous. Factors which affect the erosive potential of a solution include pH, titratable acidity, common ion concentrations, and frequency and method of exposure. Abrasion and attrition are sources of physical wear and are commonly associated with tooth brushing and tooth-to-tooth contact, respectively. A combination of erosion and abrasion or attrition exacerbates wear; however, further research is required to understand the role of fluoride in protecting mineralized tissues from such processes. Abrasive wear may be seen in a wide range of patients, whereas attritive loss is usually seen in individuals with bruxism. Wear processes are implicated in the development of dentine hypersensitivity. Saliva confers the major protective function against wear due to its role in pellicle formation, buffering, acid clearance, and hard tissue remineralization. This review focuses on the physiochemical factors impacting tooth wear.

  12. Controls on wind abrasion patterns through a fractured bedrock landscape

    NASA Astrophysics Data System (ADS)

    Perkins, J. P.; Finnegan, N. J.

    2017-12-01

    Wind abrasion is an important geomorphic process for understanding arid landscape evolution on Earth and interpreting the post-fluvial history of Mars. Both the presence and orientation of wind-abraded landforms provide potentially important constraints on paleo-climatic conditions; however, such interpretations can be complicated by lithologic and structural heterogeneity. To explore the influence of pre-existing structure on wind abrasion, we exploit a natural experiment along the 10.2 Ma Lower Rio San Pedro ignimbrite in northern Chile. Here, a 3.2 Ma andesite flow erupted from Cerro de las Cuevas and deposited atop the ignimbrite, supplying wind-transportable sediment and initiating a phase of downwind abrasion. Additionally, the lava flow provides a continually varying degree of upwind topographic shielding along the ignimbrite that is reflected in a range of surface morphologies. Where fully shielded the ignimbrite surface is partially blanketed by sediment. However, as relief decreases the surface morphology shifts from large polygonal structures that emerge due to the concentration of wind abrasion along pre-existing fracture sets, to polygons that are bisected by wind-parallel grooves that cross-cut fracture sets, to linear sets of yardangs. We reconstruct the ignimbrite surface using a high-resolution digital elevation model, and calculate erosion rates ranging from 0.002 to 0.45 mm/kyr that vary strongly with degree of topographic shielding (R2 = 0.97). We use measured abrasion rates together with nearby weather station data to estimate the nondimensional Rouse number and Inertial Parameter for a range of particle sizes. From these calculations, we hypothesize that the change from fracture-controlled to flow-controlled morphology reflects increases in the grain size and inertia of particles in the suspension cloud. Where the ignimbrite experiences persistent high winds, large particles may travel in suspension and are largely insensitive to topographic

  13. The abrasive effect of commercial whitening toothpastes on eroded enamel.

    PubMed

    Mosquim, Victor; Martines Souza, Beatriz; Foratori Junior, Gerson Aparecido; Wang, Linda; Magalhães, Ana Carolina

    2017-06-01

    To evaluate the in vitro abrasive effect of commercial whitening toothpastes on eroded bovine enamel samples in respect to erosive tooth wear. 72 bovine crowns were embedded, polished and subjected to the baseline profile analysis. The samples were then protected in 2/3 of the enamel surface and were randomly assigned to six groups (n= 12/group): G1: Oral-B 3D White, G2: Close-up Diamond Attraction Power White, G3: Sorriso Xtreme White 4D, G4: Colgate Luminous White, G5: Crest (conventional toothpaste), G6:erosion only (control). All samples were submitted to an erosive pH cycling (4 x 90 seconds in 0.1% citric acid, pH 2.5, per day) and abrasive challenges (2 x 15 seconds, per day) for 7 days. After the first and the last daily cycles, the samples were subjected to abrasive challenges, using a toothbrushing machine, soft toothbrushes and slurry of the tested toothpastes (1.5 N). Between the challenges, the samples were immersed in artificial saliva. The final profile was obtained and overlaid to the baseline profile for the calculation of the erosive tooth wear (μm). The data were subjected to Kruskal-Wallis/Dunn tests (P< 0.05). G1 promoted the highest enamel wear (3.68±1.06 μm), similarly to G3 (3.17± 0.80 μm) and G4 (3.44± 1.29 μm). G3 and G4 performed similarly between them and compared with G5 (2.35± 1.44 μm). G2 (1.51± 0.95 μm) and G6 (0.85± 0.36 μm) showed the lowest enamel wear, which did not differ between them and from G5. Oral-B 3D White showed the highest abrasive potential while Close-up Diamond Attraction Power White showed the lowest abrasive potential on eroded enamel in vitro. This study showed that some commercial whitening toothpastes, especially those containing pyrophosphate associated with hydrated silica, enhanced enamel erosive wear.

  14. Ear Tubes

    MedlinePlus

    ... 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 ...

  15. Control technology for crystalline silica exposures in construction: wet abrasive blasting.

    PubMed

    Golla, Vijay; Heitbrink, William

    2004-03-01

    This study was designed to document the effect that wet abrasive blasting has on reducing worker exposure to crystalline silica, which has been associated with silicosis and premature death. In this study, worker exposure to respirable crystalline silica was monitored during wet abrasive blasting on the exterior walls of a parking garage to remove surface concrete and expose the underlying aggregate. In this process a wet sand mix comprised of 80% dry sand and 20% water was used. Sampling and analysis revealed that the geometric mean respirable quartz concentration was 0.2 mg/m(3) for workers conducting abrasive blasting and 0.06 mg/m(3) for helpers. When abrasive blasting was conducted in areas that apparently had reduced natural ventilation, dust exposures appeared to increase. When compared with other published data, this case study suggests that wet abrasive blasting causes less exposure to crystalline silica than dry abrasive blasting.

  16. Study of Effect of Impacting Direction on Abrasive Nanometric Cutting Process with Molecular Dynamics

    NASA Astrophysics Data System (ADS)

    Li, Junye; Meng, Wenqing; Dong, Kun; Zhang, Xinming; Zhao, Weihong

    2018-01-01

    Abrasive flow polishing plays an important part in modern ultra-precision machining. Ultrafine particles suspended in the medium of abrasive flow removes the material in nanoscale. In this paper, three-dimensional molecular dynamics (MD) simulations are performed to investigate the effect of impacting direction on abrasive cutting process during abrasive flow polishing. The molecular dynamics simulation software Lammps was used to simulate the cutting of single crystal copper with SiC abrasive grains at different cutting angles (0o-45o). At a constant friction coefficient, we found a direct relation between cutting angle and cutting force, which ultimately increases the number of dislocation during abrasive flow machining. Our theoretical study reveal that a small cutting angle is beneficial for improving surface quality and reducing internal defects in the workpiece. However, there is no obvious relationship between cutting angle and friction coefficient.

  17. Study of Effect of Impacting Direction on Abrasive Nanometric Cutting Process with Molecular Dynamics.

    PubMed

    Li, Junye; Meng, Wenqing; Dong, Kun; Zhang, Xinming; Zhao, Weihong

    2018-01-11

    Abrasive flow polishing plays an important part in modern ultra-precision machining. Ultrafine particles suspended in the medium of abrasive flow removes the material in nanoscale. In this paper, three-dimensional molecular dynamics (MD) simulations are performed to investigate the effect of impacting direction on abrasive cutting process during abrasive flow polishing. The molecular dynamics simulation software Lammps was used to simulate the cutting of single crystal copper with SiC abrasive grains at different cutting angles (0 o -45 o ). At a constant friction coefficient, we found a direct relation between cutting angle and cutting force, which ultimately increases the number of dislocation during abrasive flow machining. Our theoretical study reveal that a small cutting angle is beneficial for improving surface quality and reducing internal defects in the workpiece. However, there is no obvious relationship between cutting angle and friction coefficient.

  18. Resistance to abrasion of extrinsic porcelain esthetic characterization techniques.

    PubMed

    Chi, Woo J; Browning, William; Looney, Stephen; Mackert, J Rodway; Windhorn, Richard J; Rueggeberg, Frederick

    2017-01-01

    A novel esthetic porcelain characterization technique involves mixing an appropriate amount of ceramic colorants with clear, low-fusing porcelain (LFP), applying the mixture on the external surfaces, and firing the combined components onto the surface of restorations in a porcelain oven. This method may provide better esthetic qualities and toothbrush abrasion resistance compared to the conventional techniques of applying color-corrective porcelain colorants alone, or applying a clear glaze layer over the colorants. However, there is no scientific literature to support this claim. This research evaluated toothbrush abrasion resistance of a novel porcelain esthetic characterization technique by subjecting specimens to various durations of simulated toothbrush abrasion. The results were compared to those obtained using the conventional characterization techniques of colorant application only or colorant followed by placement of a clear over-glaze. Four experimental groups, all of which were a leucite reinforced ceramic of E TC1 (Vita A1) shade, were prepared and fired in a porcelain oven according to the manufacturer's instructions. Group S (stain only) was characterized by application of surface colorants to provide a definitive shade of Vita A3.5. Group GS (glaze over stain) was characterized by application of a layer of glaze over the existing colorant layer as used for Group S. Group SL (stain+LFP) was characterized by application of a mixture of colorants and clear low-fusing add-on porcelain to provide a definitive shade of Vita A3.5. Group C (Control) was used as a control without any surface characterization. The 4 groups were subjected to mechanical toothbrushing using a 1:1 water-to-toothpaste solution for a simulated duration of 32 years of clinical use. The amount of wear was measured at time intervals simulating every 4 years of toothbrushing. These parameters were evaluated longitudinally for all groups as well as compared at similar time points among

  19. Shoe heel abrasion and its possible biomechanical cause: a transversal study with infantry recruits.

    PubMed

    Baumfeld, Daniel; Raduan, Fernando C; Macedo, Benjamim; Silva, Thiago Alexandre Alves; Baumfeld, Tiago; Favato, Danilo Fabrino; de Andrade, Marco Antonio Percope; Nery, Caio

    2015-11-19

    Excessive shoe heel abrasion is of concern to patients and shoe manufacturers, but little scientific information is available about this feature and its possible causes. The purpose of this study was to relate this phenomenon with biomechanical factors that could predispose to shoe heel abrasion. Ninety-seven recruits (median age 25) were enrolled in this study. Shoe abrasion was assessed manually with a metric plastic tape on the posterior part of the heel that comes in contact with the ground. The number of sprains, foot alignment, and calf muscle shortening (Silfverskiold test) was also assessed in order to relate it with shoe heel abrasion. After using our exclusion criteria, 86 recruits and 172 were considered for this study. The most common abrasion site was the lateral portion of the heel surface (50 %). Forty-four percent of the participants had neutral hind-foot alignment and 39 % had valgus alignment. Twenty-six (30 %) patients have had previous ankle or foot sprains. Neutral foot was related with less calf muscle shortening. On the other hand, valgus hind-foot alignment was more associated with Achilles shortening (p < 0.05). Patients with neutral alignment were associated with more uniform shoe heel abrasion and varus feet were associated with more central and lateral abrasion (p < 0.05). The pattern of shoe heel abrasion was not statistically related with calf muscle shortening nor with number of sprains. This study was able to correlate shoe heel abrasion with biomechanical causes (neutral alignment-uniform abrasion/varus alignment-central and lateral abrasion). More effort has to be done to continue evaluating outsole abrasion with its possible biomechanical cause in order to predict and treat possible associated injuries.

  20. The change in retentive force of magnetic attachment by abrasion.

    PubMed

    Huang, Yuanjin; Tawada, Yasuyuki; Hata, Yoshiaki; Watanabe, Fumihiko

    2008-07-01

    Magnets are frequently applied to removable dentures as retentive attachments. A magnet-retained removable overdenture might be slightly shifted from side to side by eccentric movement in the mouth, and the surface of magnetic attachment may be worn as a result. However, the relationship between the retentive force of magnetic attachment and its surface abrasion has not been reported. The purpose of this research is to investigate this relationship. Ten Mgfit DX 400 magnetic attachments for natural tooth roots were used for this experiment. The magnetic attachments were embedded in autopolymerizing acrylic resin, and ten pairs of specimens were fabricated. A 5-mm repeated gliding motion was applied on each pair of specimens until 30 000, 50 000, or 90 000 cycles had been achieved. The abrasion machine was under 5 kg loading, and the slide speed was 60 times/min. The retentive force of magnetic attachment was measured with a tension gauge at (1) before gliding; (2) after 30 000 gliding cycles; (3)after 50 000 gliding cycles; or (4) after 90 000 gliding cycles. The average change of retentive force of ten magnetic attachments after 30 000, 50 000, and 90 000 gliding cycles was 0.016 N, 0.003 N, and -0.008 N, respectively. The change was statistically analyzed using a paired-sample t test, which showed that the number of gliding cycles did not affect the retentive force of magnetic attachment significantly. The surface of magnetic attachment after gliding was observed by a microscope, and the abrasion of this attachment surface is clearly seen.

  1. QUANTIZING TUBE

    DOEpatents

    Jensen, A.S.; Gray, G.W.

    1958-07-01

    Beam deflection tubes are described for use in switching or pulse amplitude analysis. The salient features of the invention reside in the target arrangement whereby outputs are obtained from a plurality of collector electrodes each correspondlng with a non-overlapping range of amplitudes of the input sigmal. The tube is provded with mcans for deflecting the electron beam a1ong a line in accordance with the amplitude of an input signal. The target structure consists of a first dymode positioned in the path of the beam wlth slots spaced a1ong thc deflection line, and a second dymode posltioned behind the first dainode. When the beam strikes the solid portions along the length of the first dymode the excited electrons are multiplied and collected in separate collector electrodes spaced along the beam line. Similarly, the electrons excited when the beam strikes the second dynode are multiplied and collected in separate electrodes spaced along the length of the second dyode.

  2. Neutron tubes

    DOEpatents

    Leung, Ka-Ngo [Hercules, CA; Lou, Tak Pui [Berkeley, CA; Reijonen, Jani [Oakland, CA

    2008-03-11

    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.

  3. Electron tube

    DOEpatents

    Suyama, Motohiro [Hamamatsu, JP; Fukasawa, Atsuhito [Hamamatsu, JP; Arisaka, Katsushi [Los Angeles, CA; Wang, Hanguo [North Hills, CA

    2011-12-20

    An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.

  4. Optimization of Profile and Material of Abrasive Water Jet Nozzle

    NASA Astrophysics Data System (ADS)

    Anand Bala Selwin, K. P.; Ramachandran, S.

    2017-05-01

    The objective of this work is to study the behaviour of the abrasive water jet nozzle with different profiles and materials. Taguchi-Grey relational analysis optimization technique is used to optimize the value with different material and different profiles. Initially the 3D models of the nozzle are modelled with different profiles by changing the tapered inlet angle of the nozzle. The different profile models are analysed with different materials and the results are optimized. The optimized results would give the better result taking wear and machining behaviour of the nozzle.

  5. Heat sealable, flame and abrasion resistant coated fabric

    NASA Technical Reports Server (NTRS)

    Tschirch, R. P.; Sidman, K. R. (Inventor)

    1983-01-01

    Flame retardant, abrasion resistant elastomeric compositions are disclosed which are comprised of thermoplastic polyurethane polymer and flame retarding amounts of a filler selected from decabromodiphenyloxide and antimony oxide in a 3:1 weight ratio, and decabromodiphenyloxide, antimony oxide, and ammonium polyphosphate in a 3:1:3 weight ratio respectively. Heat sealable coated fabrics employing such elastomeric compositions as coating film are produced by dissolving the elastomeric composition to form a solution, casting the solution onto a release paper and drying it to form an elastomeric film. The film is then bonded to a woven, knitted, or felted fabric.

  6. Baking soda as an abrasive in toothpastes: Mechanism of action and safety and effectiveness considerations.

    PubMed

    Hara, Anderson T; Turssi, Cecilia P

    2017-11-01

    Toothpastes can be formulated with different abrasive systems, depending on their intended clinical application. This formulation potentially affects their effectiveness and safety and, therefore, requires proper understanding. In this article, the authors focused on abrasive aspects of toothpastes containing sodium bicarbonate (baking soda), which have gained considerable attention because of their low abrasivity and good compatibility, while providing clinical effectiveness (further detailed in the other articles of this special issue). The authors first appraised the role of toothpaste abrasivity on tooth wear, exploring some underlying processes and the existing methods to determine toothpaste abrasivity. The authors reviewed the available data on the abrasivity of toothpastes containing baking soda and reported a summary of findings highlighting the clinical implications. On the basis of the collected evidence, baking soda has an intrinsic low-abrasive nature because of its comparatively lower hardness in relation to enamel and dentin. Baking soda toothpastes also may contain other ingredients, which can increase their stain removal effectiveness and, consequently, abrasivity. Even those formulations have abrasivity well within the safety limit regulatory agencies have established and, therefore, can be considered safe. Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.

  7. Laparoscopic feeding jejunostomy: also a simple technique.

    PubMed

    Albrink, M H; Foster, J; Rosemurgy, A S; Carey, L C

    1992-01-01

    Placement of feeding tubes is a common procedure for general surgeons. While the advent of percutaneous endoscopic gastrostomy has changed and improved surgical practice, this technique is contraindicated in many circumstances. In some patients placement of feeding tubes in the stomach may be contraindicated due to the risks of aspiration, gastric paresis, or gastric dysmotility. We describe a technique of laparoscopic jejunostomy tube placement which is easy and effective. It is noteworthy that this method may be used in patients who have had previous abdominal operations, and it has the added advantage of a direct peritoneal view of the viscera. We suggest that qualified laparoscopic surgeons learn the technique of laparoscopic jejunostomy.

  8. Prediction Of Abrasive And Diffusive Tool Wear Mechanisms In Machining

    NASA Astrophysics Data System (ADS)

    Rizzuti, S.; Umbrello, D.

    2011-01-01

    Tool wear prediction is regarded as very important task in order to maximize tool performance, minimize cutting costs and improve the quality of workpiece in cutting. In this research work, an experimental campaign was carried out at the varying of cutting conditions with the aim to measure both crater and flank tool wear, during machining of an AISI 1045 with an uncoated carbide tool P40. Parallel a FEM-based analysis was developed in order to study the tool wear mechanisms, taking also into account the influence of the cutting conditions and the temperature reached on the tool surfaces. The results show that, when the temperature of the tool rake surface is lower than the activation temperature of the diffusive phenomenon, the wear rate can be estimated applying an abrasive model. In contrast, in the tool area where the temperature is higher than the diffusive activation temperature, the wear rate can be evaluated applying a diffusive model. Finally, for a temperature ranges within the above cited values an adopted abrasive-diffusive wear model furnished the possibility to correctly evaluate the tool wear phenomena.

  9. Sliding-gate valve for use with abrasive materials

    DOEpatents

    Ayers, Jr., William J.; Carter, Charles R.; Griffith, Richard A.; Loomis, Richard B.; Notestein, John E.

    1985-01-01

    The invention is a flow and pressure-sealing valve for use with abrasive solids. The valve embodies special features which provide for long, reliable operating lifetimes in solids-handling service. The valve includes upper and lower transversely slidable gates, contained in separate chambers. The upper gate provides a solids-flow control function, whereas the lower gate provides a pressure-sealing function. The lower gate is supported by means for (a) lifting that gate into sealing engagement with its seat when the gate is in its open and closed positions and (b) lowering the gate out of contact with its seat to permit abrasion-free transit of the gate between its open and closed positions. When closed, the upper gate isolates the lower gate from the solids. Because of this shielding action, the sealing surface of the lower gate is not exposed to solids during transit or when it is being lifted or lowered. The chamber containing the lower gate normally is pressurized slightly, and a sweep gas is directed inwardly across the lower-gate sealing surface during the vertical translation of the gate.

  10. Abrasion resistant coating and method of making the same

    DOEpatents

    Sordelet, Daniel J.; Besser, Matthew F.

    2001-06-05

    An abrasion resistant coating is created by adding a ductile phase to a brittle matrix phase during spray coating where an Al--Cu--Fe quasicrystalline phase (brittle matrix) and an FeAl intermetallic (ductile phase) are combined. This composite coating produces a coating mostly of quasicrystal phase and an inter-splat layer of the FeAl phase to help reduce porosity and cracking within the coating. Coatings are prepared by plasma spraying unblended and blended quasicrystal and intermetallic powders. The blended powders contain 1, 5, 10 and 20 volume percent of the intermetallic powders. The unblended powders are either 100 volume percent quasicrystalline or 100 volume percent intermetallic; these unblended powders were studied for comparison to the others. Sufficient ductile phase should be added to the brittle matrix to transform abrasive wear mode from brittle fracture to plastic deformation, while at the same time the hardness of the composite should not be reduced below that of the original brittle phase material.

  11. Air abrasion experiments in U-Pb dating of zircon

    USGS Publications Warehouse

    Goldich, S.S.; Fischer, L.B.

    1986-01-01

    Air abrasion of zircon grains can remove metamict material that has lost radiogenic Pb and zircon overgrowths that were added during younger events and thereby improve the precision of the age measurements and permit closer estimates of the original age. Age discordance that resulted from a single disturbance of the U-Pb isotopic decay systems, as had been demonstrated by T.E. Krogh, can be considerably reduced, and, under favorable conditions, the ages brought into concordancy. Two or more events complicate the U-Pb systematics, but a series of abrasion experiments can be helpful in deciphering the geologic history and in arriving at a useful interpretation of the probable times of origin and disturbances. In east-central Minnesota, U.S.A., Penokean tonalite gneiss is dated at 1869 ?? 5 Ma, and sheared granite gneiss is shown to have been a high-level granite intrusion at 1982 ?? 5 Ma in the McGrath Gneiss precursor. Tonalite gneiss and a mafic granodiorite in the Rainy Lake area, Ontario, Canada, are dated at 2736 ?? 16 and 2682 ?? 4 Ma, respectively. The tonalitic phase of the Morton Gneiss, southwestern Minnesota, is dated at 3662 ?? 42 Ma. ?? 1986.

  12. Abrasion and Fragmentation Processes in Marly Sediment Transport

    NASA Astrophysics Data System (ADS)

    Le Bouteiller, C.; Naaim, F.; Mathys, N.; Lave, J.; Kaitna, R.

    2009-04-01

    In the highly erosive marly catchments of Draix (Southern Alps, France), downstream fining of sediments has been observed and can not be explained by selective sorting. Moreover, high concentrations of suspended fine sediment (up to 800 g/L) are measured during flood events in these basins. These observations lead to the hypothesis that abrasion and fragmentation of marly sediments during transport play an important role in the production of fine sediments. Several experiments are conducted in order to quantify these processes: material from the river bed is introduced into the water flow in a circular flume as well as in a large scale rotating drum. Abrasion rates range from 5 to 15%/km, depending on the lithology: marls from the upper basin are more erosive than those from the lower basin. Modifications of grain size distribution in the rough fraction are also observed. Field measurements are also conducted. Downstream of the main marly sediment sources, the river bed is composed of marls and limestone pebbles. We have sampled the river bed for analysis of grain size distribution and lithology. First results show a decrease of the proportion of marls along the river bed. This is in accordance with the high erosion rates observed in our laboratory experiments. Further investigations are planned in order to study more precisely marl grain size distribution, especially in the finer fraction.

  13. Abrasive-assisted Nickel Electroforming Process with Moving Cathode

    NASA Astrophysics Data System (ADS)

    REN, Jianhua; ZHU, Zengwei; XIA, Chunqiu; QU, Ningsong; ZHU, Di

    2017-03-01

    In traditional electroforming process for revolving parts with complex profiles, the drawbacks on surface of deposits, such as pinholes and nodules, will lead to varying physical and mechanical properties on different parts of electroformed components. To solve the problem, compositely moving cathode is employed in abrasive-assisted electroforming of revolving parts with complicated profiles. The cathode translates and rotates simultaneously to achieve uniform friction effect on deposits without drawbacks. The influences of current density and translation speed on the microstructure and properties of the electroformed nickel layers are investigated. It is found that abrasive-assisted electroforming with compound cathode motion can effectively remove the pinholes and nodules, positively affect the crystal nucleation, and refine the grains of layer. The increase of current density will lead to coarse microstructure and lower micro hardness, from 325 HV down to 189 HV. While, faster translational linear speed produces better surface quality and higher micro hardness, from 236 HV up to 283 HV. The weld-ability of the electroformed layers are also studied through the metallurgical analysis of welded joints between nickel layer and 304 stainless steel. The electrodeposited nickel layer shows fine performance in welding. The novel compound motion of cathode promotes the mechanical properties and refines the microstructure of deposited layer.

  14. Abrasion Plus Local Fibrin Sealant Instillation Produces Pleurodesis Similar to Pleurectomy in Rabbits.

    PubMed

    Marchi, Evaldo; de Carvalho, Marcus V H; Ventureli, Tiago R; Fruchi, Andre J; Lazaro, Ariane; do Carmo, Deborah C; Barreto, Thayssa Y A S; Dias, Bruno V B; Acencio, Milena M P; Teixeira, Lisete R; Light, Richard W

    2016-09-01

    Pleurodesis performed either by pleurectomy or pleural abrasion is recommended in the approach to primary spontaneous pneumothorax to avoid recurrence. However, the efficacy of parietal pleural abrasion in producing pleurodesis is questioned. This study aims to determine the efficacy of apical abrasion alone, abrasion plus fibrin sealant application, and pleurectomy in producing pleurodesis in rabbits. Rabbits were subjected to video-assisted thoracic surgery alone (control) or to video-assisted thoracic surgery with apical gauze abrasion, abrasion plus fibrin sealant instillation, or apical pleurectomy. Blood samples were collected preoperatively and 48 h and 28 days postoperatively to measure total leukocytes (white blood cell count), neutrophil counts, and serum interleukin (IL)-8 levels. After 28 days the animals were sacrificed for macroscopic evaluation of the degree of apical pleurodesis and microscopic evaluation of local pleural fibrosis and collagen deposition. White blood cell and neutrophil counts were similar in all groups, whereas the serum IL-8 level peaked at 48 h in all groups and decreased after 28 days, except in the pleurectomy group. After 28 days the abrasion plus fibrin sealant and pleurectomy groups had significantly more pleural adhesions, pleural fibrosis, and collagen deposition than the abrasion alone group, mainly due to thick mature fibers. Abrasion with local fibrin sealant instillation is as effective as pleurectomy in producing pleurodesis in rabbits. Apical pleurectomy elicits a more persistent elevation of serum IL-8 levels than apical abrasion alone or abrasion plus fibrin adhesive instillation. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  15. Tube furnace

    DOEpatents

    Foster, Kenneth G.; Frohwein, Eugene J.; Taylor, Robert W.; Bowen, David W.

    1991-01-01

    A vermiculite insulated tube furnace is heated by a helically-wound resistance wire positioned within a helical groove on the surface of a ceramic cylinder, that in turn is surroundingly disposed about a doubly slotted stainless steel cylindrical liner. For uniform heating, the pitch of the helix is of shorter length over the two end portions of the ceramic cylinder. The furnace is of large volume, provides uniform temperature, offers an extremely precise programmed heating capability, features very rapid cool-down, and has a modest electrical power requirement.

  16. Tapered pulse tube for pulse tube refrigerators

    DOEpatents

    Swift, Gregory W.; Olson, Jeffrey R.

    1999-01-01

    Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

  17. Optimization of a Tube Hydroforming Process

    NASA Astrophysics Data System (ADS)

    Abedrabbo, Nader; Zafar, Naeem; Averill, Ron; Pourboghrat, Farhang; Sidhu, Ranny

    2004-06-01

    An approach is presented to optimize a tube hydroforming process using a Genetic Algorithm (GA) search method. The goal of the study is to maximize formability by identifying the optimal internal hydraulic pressure and feed rate while satisfying the forming limit diagram (FLD). The optimization software HEEDS is used in combination with the nonlinear structural finite element code LS-DYNA to carry out the investigation. In particular, a sub-region of a circular tube blank is formed into a square die. Compared to the best results of a manual optimization procedure, a 55% increase in expansion was achieved when using the pressure and feed profiles identified by the automated optimization procedure.

  18. Monitoring of the Abrasion Processes (by the Example of Alakol Lake, Republic of Kazakhstan)

    ERIC Educational Resources Information Center

    Abitbayeva, Ainagul; Valeyev, Adilet; Yegemberdiyeva, Kamshat; Assylbekova, Aizhan; Ryskeldieva, Aizhan

    2016-01-01

    The purpose of the study is to analyze the abrasion processes in the regions of dynamically changing Alakol lake shores. Using the field method, methods of positioning by the GPS receiver and interpretation of remote sensing data, the authors determined that abrasion processes actively contributed to the formation the modern landscape, causing the…

  19. Process Monitoring Evaluation and Implementation for the Wood Abrasive Machining Process

    PubMed Central

    Saloni, Daniel E.; Lemaster, Richard L.; Jackson, Steven D.

    2010-01-01

    Wood processing industries have continuously developed and improved technologies and processes to transform wood to obtain better final product quality and thus increase profits. Abrasive machining is one of the most important of these processes and therefore merits special attention and study. The objective of this work was to evaluate and demonstrate a process monitoring system for use in the abrasive machining of wood and wood based products. The system developed increases the life of the belt by detecting (using process monitoring sensors) and removing (by cleaning) the abrasive loading during the machining process. This study focused on abrasive belt machining processes and included substantial background work, which provided a solid base for understanding the behavior of the abrasive, and the different ways that the abrasive machining process can be monitored. In addition, the background research showed that abrasive belts can effectively be cleaned by the appropriate cleaning technique. The process monitoring system developed included acoustic emission sensors which tended to be sensitive to belt wear, as well as platen vibration, but not loading, and optical sensors which were sensitive to abrasive loading. PMID:22163477

  20. Abrasive wear of ceramic wear protection at ambient and high temperatures

    NASA Astrophysics Data System (ADS)

    Varga, M.; Adam, K.; Tumma, M.; Alessio, K. O.

    2017-05-01

    Ceramic wear protection is often applied in abrasive conditions due to their excellent wear resistance. This is especially necessary in heavy industries conveying large amounts of raw materials, e.g. in steel industry. Some plants also require material transport at high temperatures and velocities, making the need of temperature stable and abrasion resistant wear protection necessary. Various types and wear behaviour of ceramic protection are known. Hence, the goal of this study is to identify the best suitable ceramic materials for abrasive conditions in harsh environments at temperatures up to 950°C and severe thermal gradients. Chamottes, known for their excellent thermal shock resistance are compared to high abrasion resistant ceramic wear tiles and a cost efficient cement-bounded hard compound. Testing was done under high-stress three-body abrasion regime with a modified ASTM G65 apparatus enabling for investigations up to ~950°C. Thereto heated abrasive is introduced into the wear track and also preheated ceramic samples were used and compared to ambient temperature experiments. Results indicate a significant temperature influence on chamottes and the hard compound. While the chamottes benefit from temperature increase, the cement-bounded hard compound showed its limitation at abrasive temperatures of 950°C. The high abrasion resistant wear tiles represented the materials with the best wear resistance and less temperature influence in the investigated range.

  1. Air-propelled abrasive grit can damage the perennial weed, quackgrass, Elytrigia repens (L.) Nevski

    USDA-ARS?s Scientific Manuscript database

    New techniques are needed to control quackgrass in organic crops. With greater than or equal to 2 applications of abrasive air-propelled (800 kPa) corncob grit to 15 cm tall quackgrass tillers, regrowth was minimal at 5 weeks after treatment. Abrasive grits may be effective tools to help manage pere...

  2. Modeling of Micro Deval abrasion loss based on some rock properties

    NASA Astrophysics Data System (ADS)

    Capik, Mehmet; Yilmaz, Ali Osman

    2017-10-01

    Aggregate is one of the most widely used construction material. The quality of the aggregate is determined using some testing methods. Among these methods, the Micro Deval Abrasion Loss (MDAL) test is commonly used for the determination of the quality and the abrasion resistance of aggregate. The main objective of this study is to develop models for the prediction of MDAL from rock properties, including uniaxial compressive strength, Brazilian tensile strength, point load index, Schmidt rebound hardness, apparent porosity, void ratio Cerchar abrasivity index and Bohme abrasion test are examined. Additionally, the MDAL is modeled using simple regression analysis and multiple linear regression analysis based on the rock properties. The study shows that the MDAL decreases with the increase of uniaxial compressive strength, Brazilian tensile strength, point load index, Schmidt rebound hardness and Cerchar abrasivity index. It is also concluded that the MDAL increases with the increase of apparent porosity, void ratio and Bohme abrasion test. The modeling results show that the models based on Bohme abrasion test and L type Schmidt rebound hardness give the better forecasting performances for the MDAL. More models, including the uniaxial compressive strength, the apparent porosity and Cerchar abrasivity index, are developed for the rapid estimation of the MDAL of the rocks. The developed models were verified by statistical tests. Additionally, it can be stated that the proposed models can be used as a forecasting for aggregate quality.

  3. Solidification/stabilization of spent abrasives and use as nonstructural concrete

    SciTech Connect

    Brabrand, D.J.; Loehr, R.C.

    1993-01-01

    Tons of spent abrasives result each year from the removal of old paint from bridges. Because the spent abrasives contain metals from the paint, some spent abrasives may be considered hazardous by the Toxicity Characteristic (TC) criteria. Incorporation of the spent blasting abrasives in nonstructural concrete (rip-rap, dolphins) offers an opportunity to recycle the spent abrasives while immobilizing potentially leachable metals. This study focused on the Portland Cement Solidification/Stabilization (S/S) of spent blasting abrasives taken from a bridge located in Southeast Texas. The study examined (a) the cadmium, chromium, and lead concentrations in extracts obtained by using the Toxicity Characteristicmore » Leaching Procedure (TCLP) and (b) the compressive strengths of Portland Cement mixes that contained different amounts of the spent abrasives. Performance was measured by meeting the TC criteria as well as the requirements for compressive strength. Study results indicated that considerable quantities of these spent abrasives can be solidified/stabilized while reducing the leachability of cadmium, chromium, and lead and producing compressive strengths over 6,895 kN/m[sup 2] (1,000 psi).« less

  4. Electron Microscopy Abrasion Analysis of Candidate Fabrics for Planetary Space Suit Protective Overgarment Application

    NASA Technical Reports Server (NTRS)

    Hennessy, Mary J.

    1992-01-01

    The Electron Microscopy Abrasion Analysis of Candidate Fabrics for Planetary Space Suit Protective Overgarment Application is in support of the Abrasion Resistance Materials Screening Test. The fundamental assumption made for the SEM abrasion analysis was that woven fabrics to be used as the outermost layer of the protective overgarment in the design of the future, planetary space suits perform best when new. It is the goal of this study to determine which of the candidate fabrics was abraded the least in the tumble test. The sample that was abraded the least will be identified at the end of the report as the primary candidate fabric for further investigation. In addition, this analysis will determine if the abrasion seen by the laboratory tumbled samples is representative of actual EVA Apollo abrasion.

  5. Behaviors of 40Cr steel treated by laser quenching on impact abrasive wear

    NASA Astrophysics Data System (ADS)

    Chen, Zhikai; Zhu, Qinghai; Wang, Jing; Yun, Xiao; He, Bing; Luo, Jingshuai

    2018-07-01

    In present work, laser quenching had been carried out to improve the impact abrasive wear resistance of 40Cr steel. The distinct microstructure between original and quenched region was demonstrated after laser quenching. Since the effect of temperature and cooling rate, the phase combinations were apparently different for quenched layer in depth. The impact abrasive wear resistance of sample was experimentally investigated and the improved level was assessed in light of the average mass loss of three repetitive tests. Worn surface was detected by means of SEM, OM and EDS, and results showed that three typical failure modes were performed during the processing of impact abrasive wear, including abrasive wear, impact effect and rolling contact fatigue. Basing on the different worn surface profile, the mainly failure mode was respectively pointed out for matrix and quenched sample, which was significantly in accordance with the result of impact abrasive wear.

  6. Wear resistance and mechanisms of composite hardfacings at abrasive impact erosion wear

    NASA Astrophysics Data System (ADS)

    Surzhenkov, A.; Viljus, M.; Simson, T.; Tarbe, R.; Saarna, M.; Casesnoves, F.

    2017-05-01

    Tungsten carbide based hardmetal containing sprayed and melted composite hardfacings are prospective for protection against abrasive wear. For selection of abrasive wear resistant hardfacings under intensive impact wear conditions, both mechanical properties (hardness, fracture toughness, etc.) and abrasive wear conditions (type of abrasive, impact velocity, etc.) should be considered. This study focuses on the wear (wear rate and mechanisms) of thick metal-matrix composite hardfacings with hardmetal (WC-Co) reinforcement produced by powder metallurgy technology. The influence of the hardmetal reinforcement type on the wear resistance at different abrasive impact erosion wear (AIEW) conditions was studied. An optimal reinforcement for various wear conditions is described. Based on wear mechanism studies, a mathematical model for wear prediction was drafted.

  7. Effect of ceramic coating by aerosol deposition on abrasion resistance of a resin composite material.

    PubMed

    Taira, Yohsuke; Hatono, Hironori; Mizukane, Masahiro; Tokita, Masahiro; Atsuta, Mitsuru

    2006-12-01

    Aerosol deposition (AD coating) is a novel technique to coat solid substances with a ceramic film. The purpose of the present study was to investigate the effect of AD coating on abrasion resistance of a resin composite material. A 5-microm-thick aluminum oxide layer was created on the polymerized resin composite. The specimen was cyclically abraded using a toothbrush abrasion simulator for 100,000 cycles. Abraded surface was then measured with a profilometer to determine the average roughness (Ra) and maximum roughness (Rmax). It was found that abrasion cycling increased the Ra value of the No-AD-coating group, but decreased the Ra and Rmax values of the AD coating group. Moreover, the AD coating group showed significantly smaller Ra and Rmax values after 100,000 abrasion cycles as compared to the No-coating control group. Microscopic observation supported these findings. In conclusion, the resistance of the resin composite against toothbrush abrasion was improved by AD coating.

  8. Tube-in-tube thermophotovoltaic generator

    DOEpatents

    Ashcroft, J.; Campbell, B.; DePoy, D.

    1998-06-30

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell. 8 figs.

  9. Tube-in-tube thermophotovoltaic generator

    DOEpatents

    Ashcroft, John; Campbell, Brian; DePoy, David

    1998-01-01

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell.

  10. Wear model simulating clinical abrasion on composite filling materials.

    PubMed

    Johnsen, Gaute Floer; Taxt-Lamolle, Sébastien F; Haugen, Håvard J

    2011-01-01

    The aim of this study was to establish a wear model for testing composite filling materials with abrasion properties closer to a clinical situation. In addition, the model was used to evaluate the effect of filler volume and particle size on surface roughness and wear resistance. Each incisor tooth was prepared with nine identical standardized cavities with respect to depth, diameter, and angle. Generic composite of 3 different filler volumes and 3 different particle sizes held together with the same resin were randomly filled in respective cavities. A multidirectional wet-grinder with molar cusps as antagonist wore the surface of the incisors containing the composite fillings in a bath of human saliva at a constant temperature of 37°C. The present study suggests that the most wear resistant filling materials should consist of medium filling content (75%) and that particles size is not as critical as earlier reported.

  11. Wire blade development for Fixed Abrasive Slicing Technique (FAST) slicing

    NASA Technical Reports Server (NTRS)

    Khattak, C. P.; Schmid, F.; Smith, M. B.

    1982-01-01

    A low cost, effective slicing method is essential to make ingot technology viable for photovoltaics in terrestrial applications. The fixed abrasive slicing technique (FAST) combines the advantages of the three commercially developed techniques. In its development stage FAST demonstrated cutting effectiveness of 10 cm and 15 cm diameter workpieces. Wire blade development is still the critical element for commercialization of FAST technology. Both impregnated and electroplated wire blades have been developed; techniques have been developed to fix diamonds only in the cutting edge of the wire. Electroplated wires show the most near term promise and this approach is emphasized. With plated wires it has been possible to control the size and shape of the electroplating, it is expected that this feature reduces kerf and prolongs the life of the wirepack.

  12. Abrasive slurry jet cutting model based on fuzzy relations

    NASA Astrophysics Data System (ADS)

    Qiang, C. H.; Guo, C. W.

    2017-12-01

    The cutting process of pre-mixed abrasive slurry or suspension jet (ASJ) is a complex process affected by many factors, and there is a highly nonlinear relationship between the cutting parameters and cutting quality. In this paper, guided by fuzzy theory, the fuzzy cutting model of ASJ was developed. In the modeling of surface roughness, the upper surface roughness prediction model and the lower surface roughness prediction model were established respectively. The adaptive fuzzy inference system combines the learning mechanism of neural networks and the linguistic reasoning ability of the fuzzy system, membership functions, and fuzzy rules are obtained by adaptive adjustment. Therefore, the modeling process is fast and effective. In this paper, the ANFIS module of MATLAB fuzzy logic toolbox was used to establish the fuzzy cutting model of ASJ, which is found to be quite instrumental to ASJ cutting applications.

  13. Mars rover rock abrasion tool performance enhanced by ultrasonic technology.

    NASA Astrophysics Data System (ADS)

    Macartney, A.; Li, X.; Harkness, P.

    2016-12-01

    The Mars exploration Athena science goal is to explore areas where water may have been present on the early surface of Mars, and investigate the palaeo-environmental conditions of these areas in relation to the existence of life. The Rock Abrasion Tool (RAT) designed by Honeybee Robotics has been one of four key Athena science payload instruments mounted on the mechanical arm of the Spirit, Opportunity and Curiosity Mars Exploration Rovers. Exposed rock surfaces weather and chemically alter over time. Although such weathered rock can present geological interest in itself, there is a limit to what can be learned. If the geological history of a landing site is to be constructed, then it is important to analyse the unweathered rock interior as clearly as possible. The rock abrasion tool's role is to substitute for a geologist's hammer, removing the weathered and chemically altered outer surface of rocks in order to view the pristine interior. The RAT uses a diamond resin standard common grinding technique, producing a 5mm depth grind with a relatively high surface roughness, achieved over a number of hours per grind and consumes approximately 11 watts of energy. This study assesses the benefits of using ultrasonic assisted grinding to improve surface smoothness. A prototype Micro-Optic UltraSonic Exfoliator (MOUSE) is tested on a range of rock types and demonstrates a number of advantages over the RAT. In addition to a smoother grind finish, these advantages include a lower rate of tool tip wear when using a tungsten carbide tip as opposed to diamond resin, less moving parts, a grind speed of minutes instead of hours, and a power consumption of only 1-5 Watts.

  14. Abrasive rolling effects on material removal and surface finish in chemical mechanical polishing analyzed by molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Si, Lina; Guo, Dan; Luo, Jianbin; Lu, Xinchun; Xie, Guoxin

    2011-04-01

    In an abrasive chemical mechanical polishing (CMP) process, materials were considered to be removed by abrasive sliding and rolling. Abrasive sliding has been investigated by many molecular dynamics (MD) studies; while abrasive rolling was usually considered to be negligible and therefore was rarely investigated. In this paper, an MD simulation was used to study the effects of abrasive rolling on material removal and surface finish in the CMP process. As the silica particle rolled across the silicon substrate, some atoms of the substrate were dragged out from their original positions and adhered to the silica particle, leaving some atomic vacancies on the substrate surface. Meanwhile, a high quality surface could be obtained. During the abrasive rolling process, the influencing factors of material removal, e.g., external down force and driving force, were also discussed. Finally, MD simulations were carried out to examine the effects of abrasive sliding on material removal under the same external down force as abrasive rolling. The results showed that the ability of abrasive rolling to remove material on the atomic scale was not notably inferior to that of abrasive sliding. Therefore, it can be proposed that both abrasive sliding and rolling play important roles in material removal in the abrasive CMP of the silicon substrate.

  15. Protective coatings for composite tubes in space applications

    NASA Technical Reports Server (NTRS)

    Dursch, Harry W.; Hendricks, Carl L.

    1987-01-01

    Protective coatings for graphite/epoxy (Gr/Ep) tubular structures for a manned Space Station truss structure were evaluated. The success of the composite tube truss structure depends on its stability to long-term exposure to the low earth orbit (LEO) environment, with particular emphasis placed on atomic oxygen. Concepts for protectively coating Gr/Ep tubes include use of inorganic coated metal foils and electroplating. These coatings were applied to Gr/Ep tubes and then subjected to simulated LEO environment to evaluate survivability of coatings and coated tubes. Evaluation included: atomic oxygen resistance, changes in optical properties and adhesion, abrasion resistance, surface preparation required, coating uniformity, and formation of microcracks in the Gr/Ep tubes caused by thermal cycling. Program results demonstrated that both phosphoric and chromic acid anodized Al foil provided excellent adhesion to Gr/Ep tubes and exhibited stable optical properties when subjected to simulated LEO environment. The SiO2/Al coatings sputtered onto Al foils also resulted in an excellent protective coating. Electroplated Ni exhibited unacceptable adhesion loss to Gr/Ep tubes during atomic oxygen exposure.

  16. Protective coatings for composite tubes in space applications

    NASA Technical Reports Server (NTRS)

    Dursch, Harry W.; Hendricks, Carl L.

    1987-01-01

    Protective coatings for graphite/epoxy (Gr/Ep) tubular structures for a Manned Space Station truss structure were evaluated. The success of the composite tube truss structure depends on its stability to long-term exposure to the Low Earth Orbit (LEO) environment with particular emphasis placed on atomic oxygen. Concepts for protectively coating Gr/Ep tubes include use of inorganic coated metal foils and electroplating. These coatings were applied to Gr/Ep tubes and then subjected to simulated LEO environmnet to evaluate survivability of coatings and coated tubes. Evaluation included: atomic oxygen resistance, changes in optical properties and adhesion, abrasion resistancem surface preparation required, coating uniformity, and formation of microcracks in the Gr/Ep tubes caused by thermal cycling. Program results demonstrated that both phosphoric and chromic acid anodized Al foil provided excellent adhesion to Gr/Ep tubes and exhibited stable optical properties when subjected to simulated LEO environment. The SiO2/Al coatings speuttered onto Al foils also resulted in an excellent protective coating. Electroplated Ni exhibited unaccepatble adhesion loss to Gr/Ep tubes during atomic oxygen exposure.

  17. Microhardness evaluation of silorane and methacrylate composites submitted to erosion and abrasion processes

    PubMed Central

    Gazola, Eloá Aguiar; Rego, Marcos Augusto; Brandt, William Cunha; D’Arce, Maria Beatriz Freitas; Liporoni, Priscila Christiane Suzy

    2015-01-01

    Abstract Objective: The aim of this study was to evaluate the Knoop hardness number (KHN) of methacrylate (MC) and silorane (SC) composites after being submitted to erosion and abrasion processes. Material and methods: Forty samples were made with each composite: MC and SC. The samples were divided into eight groups (n = 10) according to the type of composite (G1–G4, MC; G5–G8, SC) and the beverages involved in the erosion process (G1 and G5 – Control (C), without erosion, with abrasion; G2 and G6 – Orange Juice (OJ), abrasion; G3 and G7 – Smirnoff Ice® (SI), abrasion; G4 and G8 – Gatorade® (GA), abrasion). The KHN test was performed 24 h after the last cycle of erosion/abrasion. Results: The MC groups showed smaller KHN values for the SI group (p < 0.05) when compared to the Control and OJ groups; however, for the SC groups, no differences were found (p > 0.05). Conclusion: Methacrylate composite when submitted to acidic beverages erosive challenge combined with abrasive process might alter its surface microhardness. However, the beverages used in the present study were not able to interfere in silorane composite surface microhardness. PMID:28642903

  18. Aliasing Signal Separation of Superimposed Abrasive Debris Based on Degenerate Unmixing Estimation Technique

    PubMed Central

    Li, Tongyang; Wang, Shaoping; Zio, Enrico; Shi, Jian; Hong, Wei

    2018-01-01

    Leakage is the most important failure mode in aircraft hydraulic systems caused by wear and tear between friction pairs of components. The accurate detection of abrasive debris can reveal the wear condition and predict a system’s lifespan. The radial magnetic field (RMF)-based debris detection method provides an online solution for monitoring the wear condition intuitively, which potentially enables a more accurate diagnosis and prognosis on the aviation hydraulic system’s ongoing failures. To address the serious mixing of pipe abrasive debris, this paper focuses on the superimposed abrasive debris separation of an RMF abrasive sensor based on the degenerate unmixing estimation technique. Through accurately separating and calculating the morphology and amount of the abrasive debris, the RMF-based abrasive sensor can provide the system with wear trend and sizes estimation of the wear particles. A well-designed experiment was conducted and the result shows that the proposed method can effectively separate the mixed debris and give an accurate count of the debris based on RMF abrasive sensor detection. PMID:29543733

  19. Investigation into the mechanisms of closed three-body abrasive wear

    NASA Astrophysics Data System (ADS)

    Dwyer-Joyce, R. S.; Sayles, R. S.; Ioannides, E.

    1994-06-01

    Contacting components frequently fail by abrasion caused by solid contaminants in the lubricant. This process can be classified as a closed three-body abrasive wear process. The mechanisms by which trapped particles cause material removal are not fully understood. This paper describes tests using model elastohydrodynamic contacts to study these mechanisms. An optical elastohydrodynamic lubrication rig has been used to study the deformation and fracture of ductile and brittle lubricant-borne debris. A ball-on-disk machine was used to study the behavior of the particles in partially sliding contacts. Small diamond particles were used as abrasives since these were thought not to break down in the contact; wear could then be directly related to particles of a known size. The particles were found to embed in the softer surface and to scratch the harder. The mass of material worn from the ball surface was approximately proportional to the particle sliding distance and abrasive concentration. Small particles tumbled through the contact, while larger particles ploughed. Mass loss was found to increase with abrasive particle size. Individual abrasion scratches have been measured and related to the abrading particle. A simple model of the abrasive process has been developed and compared with experimental data. The discrepancies are thought to be the result of the uncertainty about the entrainment of particles into the contact.

  20. Quantitative image analysis for evaluating the abrasion resistance of nanoporous silica films on glass

    PubMed Central

    Nielsen, Karsten H.; Karlsson, Stefan; Limbach, Rene; Wondraczek, Lothar

    2015-01-01

    The abrasion resistance of coated glass surfaces is an important parameter for judging lifetime performance, but practical testing procedures remain overly simplistic and do often not allow for direct conclusions on real-world degradation. Here, we combine quantitative two-dimensional image analysis and mechanical abrasion into a facile tool for probing the abrasion resistance of anti-reflective (AR) coatings. We determine variations in the average coated area, during and after controlled abrasion. Through comparison with other experimental techniques, we show that this method provides a practical, rapid and versatile tool for the evaluation of the abrasion resistance of sol-gel-derived thin films on glass. The method yields informative data, which correlates with measurements of diffuse reflectance and is further supported by qualitative investigations through scanning electron microscopy. In particular, the method directly addresses degradation of coating performance, i.e., the gradual areal loss of antireflective functionality. As an exemplary subject, we studied the abrasion resistance of state-of-the-art nanoporous SiO2 thin films which were derived from 5–6 wt% aqueous solutions of potassium silicates, or from colloidal suspensions of SiO2 nanoparticles. It is shown how abrasion resistance is governed by coating density and film adhesion, defining the trade-off between optimal AR performance and acceptable mechanical performance. PMID:26656260

  1. Study of Abrasive Wear Volume Map for PTFE and PTFE Composites

    NASA Astrophysics Data System (ADS)

    Unal, H.; Sen, U.; Mimaroglu, A.

    2007-11-01

    The potential of this work is based on consideration of wear volume map for the evaluation of abrasive wear performance of polytetrafluoroethylene (PTFE) and PTFE composites. The fillers used in the composite are 25% bronze, 35% graphite and 17% glass fibre glass (GFR). The influence of filler materials, abrasion surface roughness and applied load values on abrasive wear performance of PTFE and PTFE composites were studied and evaluated. Experimental abrasive wear tests were carried out at atmospheric condition on pin-on-disc wear tribometer. Tests were performed under 4, 6, 8 and 10 N load values, travelling speed of 1 m/sec and abrasion surface roughness values of 5, 20 and 45 µm. Wear volume maps were obtained and the results showed that the lowest wear volume rate for PTFE is reached using GFR filler. Furthermore, the results also showed that the higher is the applied load and the roughness of the abrasion surface, the higher is the wear rate. Finally it is also concluded that abrasive wear process mechanism include ploughing and cutting mechanisms.

  2. Aliasing Signal Separation of Superimposed Abrasive Debris Based on Degenerate Unmixing Estimation Technique.

    PubMed

    Li, Tongyang; Wang, Shaoping; Zio, Enrico; Shi, Jian; Hong, Wei

    2018-03-15

    Leakage is the most important failure mode in aircraft hydraulic systems caused by wear and tear between friction pairs of components. The accurate detection of abrasive debris can reveal the wear condition and predict a system's lifespan. The radial magnetic field (RMF)-based debris detection method provides an online solution for monitoring the wear condition intuitively, which potentially enables a more accurate diagnosis and prognosis on the aviation hydraulic system's ongoing failures. To address the serious mixing of pipe abrasive debris, this paper focuses on the superimposed abrasive debris separation of an RMF abrasive sensor based on the degenerate unmixing estimation technique. Through accurately separating and calculating the morphology and amount of the abrasive debris, the RMF-based abrasive sensor can provide the system with wear trend and sizes estimation of the wear particles. A well-designed experiment was conducted and the result shows that the proposed method can effectively separate the mixed debris and give an accurate count of the debris based on RMF abrasive sensor detection.

  3. Relationships Between Abrasive Wear, Hardness, and Surface Grinding Characteristics of Titanium-Based Metal Matrix Composites

    SciTech Connect

    Blau, Peter Julian; Jolly, Brian C

    2009-01-01

    The objective of this work was to support the development of grinding models for titanium metal-matrix composites (MMCs) by investigating possible relationships between their indentation hardness, low-stress belt abrasion, high-stress belt abrasion, and the surface grinding characteristics. Three Ti-based particulate composites were tested and compared with the popular titanium alloy Ti-6Al-4V. The three composites were a Ti-6Al-4V-based MMC with 5% TiB{sub 2} particles, a Ti-6Al-4V MMC with 10% TiC particles, and a Ti-6Al-4V/Ti-7.5%W binary alloy matrix that contained 7.5% TiC particles. Two types of belt abrasion tests were used: (a) a modified ASTM G164 low-stress loop abrasion test, and (b)more » a higher-stress test developed to quantify the grindability of ceramics. Results were correlated with G-ratios (ratio of stock removed to abrasives consumed) obtained from an instrumented surface grinder. Brinell hardness correlated better with abrasion characteristics than microindentation or scratch hardness. Wear volumes from low-stress and high-stress abrasive belt tests were related by a second-degree polynomial. Grindability numbers correlated with hard particle content but were also matrix-dependent.« less

  4. Heat exchanger tube mounts

    DOEpatents

    Wolowodiuk, W.; Anelli, J.; Dawson, B.E.

    1974-01-01

    A heat exchanger in which tubes are secured to a tube sheet by internal bore welding is described. The tubes may be moved into place in preparation for welding with comparatively little trouble. A number of segmented tube support plates are provided which allow a considerable portion of each of the tubes to be moved laterally after the end thereof has been positioned in preparation for internal bore welding to the tube sheet. (auth)

  5. Breast-Feeding Twins: Making Feedings Manageable

    MedlinePlus

    ... breast-feed more than one baby? Here's help breast-feeding twins or other multiples, from getting positioned and ensuring an adequate milk supply to combining breast-feeding and formula-feeding. By Mayo Clinic Staff If ...

  6. Lunar Regolith Simulant Feed System for a Hydrogen Reduction Reactor System

    NASA Technical Reports Server (NTRS)

    Mueller, R. P.; Townsend, Ivan I., III

    2009-01-01

    One of the goals of In-Situ Resource Utilization (ISRU) on the moon is to produce oxygen from the lunar regolith which is present in the form of Ilmenite (FeTi03) and other compounds. A reliable and attainable method of extracting some of the oxygen from the lunar regolith is to use the hydrogen reduction process in a hot reactor to create water vapor which is then condensed and electrolyzed to obtain oxygen for use as a consumable. One challenge for a production system is to reliably acquire the regolith with an excavator hauler mobility platform and then introduce it into the reactor inlet tube which is raised from the surface and above the reactor itself. After the reaction, the hot regolith (-1000 C) must be expelled from the reactor for disposal by the excavator hauler mobility system. In addition, the reactor regolith inlet and outlet tubes must be sealed by valves during the reaction in order to allow collection of the water vapor by the chemical processing sub-system. These valves must be able to handle abrasive regolith passing through them as well as the heat conduction from the hot reactor. In 2008, NASA has designed and field tested a hydrogen reduction system called ROxygen in order to demonstrate the feasibility of extracting oxygen from lunar regolith. The field test was performed with volcanic ash known as Tephra on Mauna Kea volcano on the Big Island of Hawai'i. The tephra has similar properties to lunar regolith, so that it is regarded as a good simulant for the hydrogen reduction process. This paper will discuss the design, fabrication, operation, test results and lessons learned with the ROxygen regolith feed system as tested on Mauna Kea in November 2008.

  7. Evaluation of Needle Gun and Abrasive Blasting Technologies in Bridge Paint Removal Practices.

    PubMed

    Randall, Paul M; Kranz, Paul B; Sonntag, Mary L; Stadelmaier, James E

    1998-03-01

    This paper reviews the results of a U.S. Environmental Protection Agency (EPA) study that assessed needle gun technology as an alternative to conventional abrasive blasting technology to remove lead-based paint from steel bridges in western New York State. The study analyzed the operational and logistical aspects as they relate to worker health and safety, environmental protection, hazardous waste generation, and costs as compared to those arising from conventional abrasive blasting. In this 1992 EPA study, the costs and the product quality aspects favored conventional abrasive blasting over the needle gun technology for removing lead paint. However, abrasive blasting exposed workers to airborne lead levels that exceeded Permissible Exposure Limits (PELs) as established by the Occupational Safety and Health Administration (OSHA), as well as emitting high levels of lead-contaminated dusts and debris into the environment. It was estimated that more than 500 lbs of lead-contaminated spent abrasives and paint waste were released into the environment during paint removal operations. The needle gun system reduced (up to 97.5%) the generation of hazardous waste and the airborne concentrations (up to 99%) of respirable dusts and lead-containing particulates generated during paint removal operations. However, labor costs for the needle gun were three times higher than those for abrasive blasting primarily because of slower production rates that necessitated more operating personnel. The higher labor costs of the needle gun are partially offset by the increased costs associated with the expendable abrasive blast media and hazardous waste disposal. In the EPA study, the productivity of the needle gun system was 12.2 ft 2 /hr vs. 147.5 ft 2 /hr for abrasive blasting. A post blast was needed for the needle gun system to meet surface preparation specifications. When factoring in the costs of full containment structures to meet OSHA's 1993 Lead Exposure in Construction regulation

  8. Empirically supported treatments for feeding difficulties in young children.

    PubMed

    Davis, Ann McGrath; Bruce, Amanda; Cocjin, Jose; Mousa, Hayat; Hyman, Paul

    2010-06-01

    Pediatric feeding problems are common among children and present severe issues for families. Unfortunately, treatment outcome studies with this population are sparse. The current study reviews the literature regarding treatment studies of children with severe feeding issues, provides an overview of empirically supported treatments for children who do eat orally, and finally summarizes interventions that attempt to reintroduce oral feeding to children who have been fed by gastrostomy tube or other non-oral feeding route.

  9. Optical-model abrasion cross sections for high-energy heavy ions

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.

    1981-01-01

    Within the context of eikonal scattering theory, a generalized optical model potential approximation to the nucleus-nucleus multiple scattering series is used in an abrasion-ablation collision model to predict abrasion cross sections for relativistic projectile heavy ions. Unlike the optical limit of Glauber theory, which cannot be used for very light nuclei, the abrasion formalism is valid for any projectile target combination at any incident kinetic energy for which eikonal scattering theory can be utilized. Results are compared with experimental results and predictions from Glauber theory.

  10. Target correlation effects on neutron-nucleus total, absorption, and abrasion cross sections

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Townsend, Lawrence W.; Wilson, John W.

    1991-01-01

    Second order optical model solutions to the elastic scattering amplitude were used to evaluate total, absorption, and abrasion cross sections for neutron nucleus scattering. Improved agreement with experimental data for total and absorption cross sections is found when compared with first order (coherent approximation) solutions, especially below several hundred MeV. At higher energies, the first and second order solutions are similar. There are also large differences in abrasion cross section calculations; these differences indicate a crucial role for cluster knockout in the abrasion step.

  11. New vibration-assisted magnetic abrasive polishing (VAMAP) method for microstructured surface finishing.

    PubMed

    Guo, Jiang; Kum, Chun Wai; Au, Ka Hing; Tan, Zhi'En Eddie; Wu, Hu; Liu, Kui

    2016-06-13

    In order to polish microstructured surface without deteriorating its profile, we propose a new vibration-assisted magnetic abrasive polishing (VAMAP) method. In this method, magnetic force guarantees that the magnetic abrasives can well contact the microstructured surface and access the corners of microstructures while vibration produces a relative movement between microstructures and magnetic abrasives. As the vibration direction is parallel to the microstructures, the profile of the microstructures will not be deteriorated. The relation between vibration and magnetic force was analyzed and the feasibility of this method was experimentally verified. The results show that after polishing, the surface finish around microstructures was significantly improved while the profile of microstructures was well maintained.

  12. Three-Body Abrasion Testing Using Lunar Dust Simulants to Evaluate Surface System Materials

    NASA Technical Reports Server (NTRS)

    Kobrick, Ryan L.; Budinski, Kenneth G.; Street, Kenneth W., Jr.; Klaus, David M.

    2010-01-01

    Numerous unexpected operational issues relating to the abrasive nature of lunar dust, such as scratched visors and spacesuit pressure seal leaks, were encountered during the Apollo missions. To avoid reoccurrence of these unexpected detrimental equipment problems on future missions to the Moon, a series of two- and three-body abrasion tests were developed and conducted in order to begin rigorously characterizing the effect of lunar dust abrasiveness on candidate surface system materials. Two-body scratch tests were initially performed to examine fundamental interactions of a single particle on a flat surface. These simple and robust tests were used to establish standardized measurement techniques for quantifying controlled volumetric wear. Subsequent efforts described in the paper involved three-body abrasion testing designed to be more representative of actual lunar interactions. For these tests, a new tribotester was developed to expose samples to a variety of industrial abrasives and lunar simulants. The work discussed in this paper describes the three-body hardware setup consisting of a rotating rubber wheel that applies a load on a specimen as a loose abrasive is fed into the system. The test methodology is based on ASTM International (ASTM) B611, except it does not mix water with the abrasive. All tests were run under identical conditions. Abraded material specimens included poly(methyl methacrylate) (PMMA), hardened 1045 steel, 6061-T6 aluminum (Al) and 1018 steel. Abrasives included lunar mare simulant JSC- 1A-F (nominal size distribution), sieved JSC-1A-F (<25 m particle diameter), lunar highland simulant NU-LHT-2M, alumina (average diameter of 50 m used per ASTM G76), and silica (50/70 mesh used per ASTM G65). The measured mass loss from each specimen was converted using standard densities to determine total wear volume in cm3. Abrasion was dominated by the alumina and the simulants were only similar to the silica (i.e., sand) on the softer materials of

  13. Surface assessment and modification of concrete using abrasive blasting

    NASA Astrophysics Data System (ADS)

    Millman, Lauren R.

    Composite systems are applied to concrete substrates to strengthen and extend the service life. Successful restoration or rehabilitation requires surface preparation prior to the application of the overlay. Surface coatings, waterproofing systems, and other external surface applications also require surface preparation prior to application. Abrasive blast media is often used to clean and uniformly roughen the substrate. The appropriate surface roughness is necessary to facilitate a strong bond between the existing substrate and overlay. Thus, surface modification using abrasive blast media (sand and dry ice), their respective environmental effects, surface roughness characterization prior to and after blasting, and the adhesion between the substrate and overlay are the focus of this dissertation. This dissertation is comprised of an introduction, a literature review, and four chapters, the first of which addresses the environmental effects due to abrasive blasting using sand, water, and dry ice. The assessment considered four response variables: carbon dioxide (CO2) emissions, fuel and energy consumption, and project duration. The results indicated that for sand blasting and water jetting, the primary factor contributing to environmental detriment was CO22 emissions from vehicular traffic near the construction site. The second chapter is an analysis of the International Concrete Repair Institute's (ICRI) concrete surface profiles (CSPs) using 3-D optical profilometry. The primary objective was to evaluate the suitability of approximating the 3-D surface (areal) parameters with those extracted from 2-D (linear) profiles. Four profile directions were considered: two diagonals, and lines parallel and transverse to the longitudinal direction of the mold. For any CSP mold, the estimation of the 3-D surface roughness using a 2-D linear profile resulted in underestimation and overestimation errors exceeding 50%, demonstrating the inadequacy of 2-D linear profiles to

  14. Durability of resin cement bond to aluminium oxide and zirconia ceramics after air abrasion and laser treatment.

    PubMed

    Foxton, Richard M; Cavalcanti, Andrea N; Nakajima, Masatoshi; Pilecki, Peter; Sherriff, Martyn; Melo, Luciana; Watson, Timothy F

    2011-02-01

    The erbium laser has been introduced for cutting enamel and dentin and may have an application in the surface modification of high-strength aluminum oxide and zirconia ceramics. The aim of this study was to evaluate the durability of the bond of conventional dual-cured resin cements to Procera Al(2)O(3) and zirconium oxide ceramics after surface treatment with air abrasion and erbium laser. One hundred twenty Al(2)O(3) and 120 zirconia specimens measuring 3 × 3 × 0.7 mm(3) were divided equally into three groups, and their surfaces treated as follows: either untreated (controls), air abraded with Al(2)O(3) particles, or erbium-laser-treated at a power setting of 200 mJ. The surface of each specimen was then primed and bonded with one of two dual-cured resin cements (either SCP-100 Ceramic Primer and NAC-100 or Monobond S and Variolink II) using a 1-mm thick Tygon tube mold with a 0.75-mm internal bore diameter. After 24 hours and 6 months of water storage at 37°C, a microshear bond strength test was performed at a crosshead speed of 1 mm/min. Surface morphology was examined using a confocal microscope, and failure modes were observed using an optical microscope. The data were analyzed using the Kaplan-Meier nonparametric survival analysis. In the case of zirconia, air abrasion and Erbium:yttrium-aluminum-garnet (Er:YAG) laser treatment of the ceramic surface resulted in a significant reduction in the bond strengths of both resin cements after 6 months water storage; however, when the zirconia surface was left untreated, the SCP-100/NAC-100 group did not significantly reduce in bond strength. In the case of alumina, no treatment, air abrasion and Er:YAG laser treatment of the surface led to no significant reduction in the bond strengths of the three SCP-100/NAC-100 groups after 6 months water storage, whereas all three Monobond S/Variolink II groups showed a significant reduction. Er:YAG laser treatment of the zirconia surface did not result in a durable resin

  15. Clinical tube weaning supported by hunger provocation in fully-tube-fed children.

    PubMed

    Hartdorff, Caroline M; Kneepkens, C M Frank; Stok-Akerboom, Anita M; van Dijk-Lokkart, Elisabeth M; Engels, Michelle A H; Kindermann, Angelika

    2015-04-01

    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 < 0.001). Multidisciplinary clinical hunger provocation is an effective short-term intervention for weaning young children from tube feeding.

  16. Optimization and application of influence function in abrasive jet polishing.

    PubMed

    Li, Zhaoze; Li, Shengyi; Dai, Yifan; Peng, Xiaoqiang

    2010-05-20

    We analyze the material removal mechanism of abrasive jet polishing (AJP) technology, based on the fluid impact dynamics theory. Combined with the computational fluid dynamics simulation and process experiments, influence functions at different impingement angles are obtained, which are not of a regular Gaussian shape and are unfit for the corrective figuring of optics. The influence function is then optimized to obtain an ideal Gaussian shape by rotating the oblique nozzle, and its stability is validated through a line scanning experiment. The fluctuation of the influence function can be controlled within +/-5%. Based on this, we build a computed numerically controlled experimental system for AJP, and one flat BK7 optical glass with a diameter of 20mm is polished. After two iterations of polishing, the peak-to-valley value decreases from 1.43lambda (lambda=632.8nm in this paper) to 0.294lambda, and the rms value decreases from 0.195lambda to 0.029lambda. The roughness of this polished surface is within 2nm. The experimental result indicates that the optimized influence function is suitable for precision optics figuring and polishing.

  17. Abrasive wear of Hilong BoTN hardfacings

    NASA Astrophysics Data System (ADS)

    Fedorova, L.; Fedorov, S.; Sadovnikov, A.; Ivanova, Y.; Voronina, M.

    2018-02-01

    The spread of steels, which are used to produce locks of steel drill pipes, adversely affects their wear resistance, which, in combination with low hardness of HV 2400 ... 2800 MPa as well as of the thread of screw, results in low wear resistance and the need for their reconstruction at the pipe control shop. An efficient way of improving the quality of drill pipe jonts is to hard-face them by the outside diameter with wear-resistant materials (hardbanding). One of the companies engaged in the development of hardfacing materials and hardbanding is Hilong (China) with weld seams of the brand BoTn. According to the results of the studies the following conclusion can be made: hardfacing increases the durability of the hardware, contributing to an increase in wear resistance of locks of DP under the conditions of abrasive action of aggressive geological formations; the usage of DP without wear-resistant weld seams is impermissible, because their further operation, as part of the drill-stem, can lead to emergency consequences; application of the pipes with the hardfacing collars together with the collars without hardfacing, due to varying degree of wear of jonts in the drill-stem, is also impermissible.

  18. Experimental investigation of the abrasive crown dynamics in orbital atherectomy.

    PubMed

    Zheng, Yihao; Belmont, Barry; Shih, Albert J

    2016-07-01

    Orbital atherectomy is a catheter-based minimally invasive procedure to modify the plaque within atherosclerotic arteries using a diamond abrasive crown. This study was designed to investigate the crown motion and its corresponding contact force with the vessel. To this end, a transparent arterial tissue-mimicking phantom made of polyvinyl chloride was developed, a high-speed camera and image processing technique were utilized to visualize and quantitatively analyze the crown motion in the vessel phantom, and a piezoelectric dynamometer measured the forces on the phantom during the procedure. Observed under typical orbital atherectomy rotational speeds of 60,000, 90,000, and 120,000rpm in a 4.8mm caliber vessel phantom, the crown motion was a combination of high-frequency rotation at 1000, 1500, and 1660.4-1866.1Hz and low-frequency orbiting at 18, 38, and 40Hz, respectively. The measured forces were also composed of these high and low frequencies, matching well with the rotation of the eccentric crown and the associated orbital motion. The average peak force ranged from 0.1 to 0.4N at different rotational speeds. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  19. Abrasion-set limits on Himalayan gravel flux.

    PubMed

    Dingle, Elizabeth H; Attal, Mikaël; Sinclair, Hugh D

    2017-04-26

    Rivers sourced in the Himalayan mountain range carry some of the largest sediment loads on the planet, yet coarse gravel in these rivers vanishes within approximately 10-40 kilometres on entering the Ganga Plain (the part of the North Indian River Plain containing the Ganges River). Understanding the fate of gravel is important for forecasting the response of rivers to large influxes of sediment triggered by earthquakes or storms. Rapid increase in gravel flux and subsequent channel bed aggradation (that is, sediment deposition by a river) following the 1999 Chi-Chi and 2008 Wenchuan earthquakes reduced channel capacity and increased flood inundation. Here we present an analysis of fan geometry, sediment grain size and lithology in the Ganga Basin. We find that the gravel fluxes from rivers draining the central Himalayan mountains, with upstream catchment areas ranging from about 350 to 50,000 square kilometres, are comparable. Our results show that abrasion of gravel during fluvial transport can explain this observation; most of the gravel sourced more than 100 kilometres upstream is converted into sand by the time it reaches the Ganga Plain. These findings indicate that earthquake-induced sediment pulses sourced from the Greater Himalayas, such as that following the 2015 Gorkha earthquake, are unlikely to drive increased gravel aggradation at the mountain front. Instead, we suggest that the sediment influx should result in an elevated sand flux, leading to distinct patterns of aggradation and flood risk in the densely populated, low-relief Ganga Plain.

  20. Feeding method and health outcomes of children with cerebral palsy.

    PubMed

    Rogers, Brian

    2004-08-01

    Disorders of feeding and swallowing are common in children with cerebral palsy. Feeding and swallowing disorders have significant implications for development, growth and nutrition, respiratory health, gastrointestinal function, parent-child interaction, and overall family life. Assessments need to be comprehensive in scope and centered around the medical home. Oral feeding interventions for children with cerebral palsy may be effective in promoting oral motor function, but have not been shown to be effective in promoting feeding efficiency or weight gain. Feeding gastrostomy tubes are a reasonable alternative for children with severe feeding and swallowing problems who have had poor weight gain. Copyright 2004 Elsevier Inc.

  1. Report D : self-consolidating concrete (SCC) for infrastructure elements - creep, shrinkage and abrasion resistance.

    DOT National Transportation Integrated Search

    2012-08-01

    Concrete specimens were fabricated for shrinkage, creep, and abrasion resistance : testing. Variations of self-consolidating concrete (SCC) and conventional concrete were : all tested. The results were compared to previous similar testing programs an...

  2. Effect of dried sunflower seeds on incisal edge abrasion: A rare case report.

    PubMed

    Rath, Avita; Ramamurthy, Priyadarshini H; Fernandes, Bennete Aloysius; Sidhu, Preena

    2017-01-01

    Tooth surface loss (TSL) is a complex phenomenon characterized by the loss of hard tooth structure at various locations of the teeth, usually due to more than one factor. TSL due to abrasion can be significant in patients consuming coarse, abrasive diet. The present case reports an interesting incisal edge abrasion in a female patient, attributed to a particular dietary behavior of long-term consumption of sunflower seeds. All her family members and most of the people from her native place were also reported to have similar lesions by the patient. Larger epidemiological studies to assess the prevalence and severity of such abrasive lesions in geographic areas with this particular dietary habit need to be carried out so that people may be made aware and educated about alternative ways of eating sunflower seeds that will not cause any form of tooth wear.

  3. Abrasion-resistant concrete mix designs for precast bridge deck panels.

    DOT National Transportation Integrated Search

    2010-08-01

    The report documents laboratory investigations undertaken to develop high performance concrete (HPC) for precast and pre-stressed bridge deck components that would reduce the life-cycle cost of bridges by improving the studded tire wear (abrasion) re...

  4. Abrasion and deformed layer formation of manganese-zinc ferrite in sliding contact with lapping tapes

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.; Tanaka, K.

    1986-01-01

    Wear experiments were conducted using replication electron microscopy and reflection electron diffraction to study abrasion and the deformed layers produced in single-crystal Mn-Zn ferrite simulated heads during contact with lapping tapes. The crystaline state of the head is changed drastically during the abrasion process. Crystalline states ranging from nearly amorphous to highly textured polycrystalline can be produced on the wear surface of a single-crystal Mn-Zn ferrite head. The total thickness of the deformed layer was approximately 0.8 microns. This thickness increased as the load and abrasive grit size increased. The anisotropic wear of the ferrite was found to be inversely proportional to the hardness of the wear surface. The wear was lower in the order 211 111 10 0110. The wear of the ferrite increased markedly with an increase in sliding velocity and abrasive grit size.

  5. A modeling of elementary passes taking into account the firing angle in abrasive water jet machining of titanium alloy

    NASA Astrophysics Data System (ADS)

    Bui, Van-Hung; Gilles, Patrick; Cohen, Guillaume; Rubio, Walter

    2018-05-01

    The use of titanium alloys in the aeronautical and high technology domains is widespread. The high strength and the low mass are two outstanding characteristics of titanium alloys which permit to produce parts for these domains. As other hard materials, it is challenging to generate 3D surfaces (e.g. pockets) when using conventional cutting methods. The development of Abrasive Water Jet Machining (AWJM) technology shows the capability to cut any kind of materials and it seems to be a good solution for such titanium materials with low specific force, low deformation of parts and low thermal shocks. Applying this technology for generating 3D surfaces requires to adopt a modelling approach. However, a general methodology results in complex models due to a lot of parameters of the machining process and based on numerous experiments. This study introduces an extended geometry model of an elementary pass when changing the firing angle during machining Ti-6AL-4V titanium alloy with a given machine configuration. Several experiments are conducted to observe the influence of major kinematic operating parameters, i.e. jet inclination angle (α) (perpendicular to the feed direction) and traverse speed (Vf). The material exposure time and the erosion capability of abrasives particles are affected directly by a variation of the traverse speed (Vf) and firing angle (α). These variations lead to different erosion rates along the kerf profile characterized by the depth and width of cut. A comparison demonstrated an efficiency of the proposed model for depth and width of elementary passes. Based on knowledge of the influence of both firing angle and traverse speed on the elementary pass shape, the proposed model allows to develop the simulation of AWJM process and paves a way for milling flat bottom pockets and 3D complex shapes.

  6. Feasibility and Economics Study of the Treatment, Recycling and Disposal of Spent Abrasives

    DTIC Science & Technology

    1999-04-09

    compression, and film stripping. The recycling performance testing plan is summarized in Table 2. (The test plan is discussed in detail in Appendix B: Law...D1188 Yes Yes Immersion Compression ................... ASTM C4867 Yes Yes Film Stripping................................... CalTrans 302 Yes Yes...from 10% to 20% for aluminum oxide abrasives, and 15% to 30% for garnet abrasives. 9 Data Intepretation SSPC-AB 1 requires that the conductivitiy of

  7. Characterization of Conventional and High-Translucency Y-TZP Dental Ceramics Submitted to Air Abrasion.

    PubMed

    Tostes, Bhenya Ottoni; Guimarães, Renato Bastos; Noronha-Filho, Jaime Dutra; Botelho, Glauco Dos Santos; Guimarães, José Guilherme Antunes; Silva, Eduardo Moreira da

    2017-01-01

    This study evaluated the effect of air-abrasion on t®m phase transformation, roughness, topography and the elemental composition of three Y-TZP (Yttria-stabilized tetragonal zirconia polycrystal) dental ceramics: two conventional (Lava Frame and IPS ZirCad) and one with high-translucency (Lava Plus). Plates obtained from sintered blocks of each ceramic were divided into four groups: AS (as-sintered); 30 (air-abrasion with 30 mm Si-coated Al2O3 particles); 50 (air-abrasion with 50 mm Al2O3 particles) and 150 (air-abrasion with 150 mm Al2O3 particles). After the treatments, the plates were submitted to X-ray diffractometry; 3-D profilometry and SEM/EDS. The AS surfaces were composed of Zr and t phases. All treatments produced t®m phase transformation in the ceramics. The diameter of air-abrasion particles influenced the roughness (150>50>30>AS) and the topography. SEM analysis showed that the three treatments produced groove-shaped microretentions on the ceramic surfaces, which increased with the diameter of air-abrasion particles. EDS showed a decrease in Zr content along with the emergence of O and Al elements after air-abrasion. Presence of Si was also detected on the plates air-abraded with 30 mm Si-coated Al2O3 particles. It was concluded that irrespective of the type and diameter of the particles, air-abrasion produced t®m phase transformation, increased the roughness and changed the elemental composition of the three Y-TZP dental ceramics. Lava Plus also behaved similarly to the conventional Y-TZP ceramics, indicating that this high translucency ceramic could be more suitable to build monolithic ceramic restorations in the aesthetic restorative dentistry field.

  8. Abrasive Wear of Four Direct Restorative Materials by Standard and Whitening Dentifrices

    DTIC Science & Technology

    2013-06-01

    after an acidic challenge . Enamel loss was significantly greater when erosive and abrasive effects were combined. They concluded that acid-softened...surrounding soft tissues. Another benefit of restoration is the elimination of a challenging area for the patient and hygienist to clean. These areas...abrasion challenge ; the resin cement with the smallest sized filler particles had the smallest weight loss and maintained the smoothest surface of all the

  9. Bender/Coiler for Tubing

    NASA Technical Reports Server (NTRS)

    Stoltzfus, J. M.

    1983-01-01

    Easy-to-use tool makes coils of tubing. Tubing to be bend clamped with stop post. Die positioned snugly against tubing. Operator turns handle to slide die along tubing, pushing tubing into spiral groove on mandrel.

  10. Breast Feeding.

    ERIC Educational Resources Information Center

    International Children's Centre, Paris (France).

    This set of documents consists of English, French, and Spanish translations of four pamphlets on breast-feeding. The pamphlets provide information designed for lay persons, academics and professionals, health personnel and educators, and policy-makers. The contents cover health-related differences between breast and bottle milk; patterns of…

  11. [Complementary feeding].

    PubMed

    Pérez Lizaur, Ana Bertha

    2011-01-01

    According to PAHO and WHO, supplementary feeding is the process that begins when human milk is insufficient to meet the nutritional needs of an infant and requires other foods and liquids. The decision to begin complementary feeding depends on socio-economic, physiological, nutritional and psychological factors. The maturation of the neuromuscular, gastrointestinal and renal system influences the chances of success of supplementary feeding. Reflexes and skills in a child with normal development can be expected and the consistency of foods can provide a way to, on one hand allow the ingestion of food and the other to allow the children to exercise their reflexes to enhance neuromuscular maturation. WHO recommends exclusive breastfeeding promotion to six months, as there are several benefits to mother and child; in Mexico, the NOM-043-SSA2-2005 promotes complementary feeding from 6 months. It should be noted that the order of introduction is not definitive and that the literature shows different patterns of input according to the needs of children and their socio-economic and cultural environment. Parents and caregivers select and buy food, model, and establish rules of behavior at home related to food. Evidence suggest that environmental factors acting at an early stage of development of small modeling preferences and eating behaviors.

  12. Mangrove Cultivation For Dealing With Coastal Abrasion Case Study Of Karangsong

    NASA Astrophysics Data System (ADS)

    Fatimatuzzahroh, Feti; Hadi, Sudharto P.; Purnaweni, Hartuti

    2018-02-01

    Coastal abrasion is consequence from destructive waves and sea current. One of cause is human intervention. The effort to solve of abrasion is by mangrove cultivation. Mangroves are halophyte plant that can restrain the sea wave. Mangrove cultivation required participation community that give awareness the importance of mangrove in coastal sustainability. Mangroves in coastal Karangsong, Indramayu west java, in 2007 was through abrasion approximately 127.30 ha. Mangrove cultivation in Karangsong has been replanting since 1998 to 2003, but there was no maintenance and management. In 2007 until 2015 Karangsong replanting mangroves and has been succeed. Karangsong became the center of mangrove study for west java area in 2015. This achievement is result of cooperation between community, NGO, and local government. In addition, this effort made not only overcome the abrasion problem but also give community awareness about the importance of mangrove cultivation in preventing coastal abrasion throughout community development. This paper reviews abrasion in Karangsong and the impact for local community and empowerment in mangrove cultivation. To achieve the success mangrove cultivation required community development approach from planning process, planting, maintenance and management.

  13. Kinetic energy density and agglomerate abrasion rate during blending of agglomerates into powders.

    PubMed

    Willemsz, Tofan A; Hooijmaijers, Ricardo; Rubingh, Carina M; Tran, Thanh N; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees

    2012-01-23

    Problems related to the blending of a cohesive powder with a free flowing bulk powder are frequently encountered in the pharmaceutical industry. The cohesive powder often forms lumps or agglomerates which are not dispersed during the mixing process and are therefore detrimental to blend uniformity. Achieving sufficient blend uniformity requires that the blending conditions are able to break up agglomerates, which is often an abrasion process. This study was based on the assumption that the abrasion rate of agglomerates determines the required blending time. It is shown that the kinetic energy density of the moving powder bed is a relevant parameter which correlates with the abrasion rate of agglomerates. However, aspects related to the strength of agglomerates should also be considered. For this reason the Stokes abrasion number (St(Abr)) has been defined. This parameter describes the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. The St(Abr) number is shown to predict the abrasion potential of agglomerates in the dry-mixing process. It appeared possible to include effects of filler particle size and impeller rotational rate into this concept. A clear relationship between abrasion rate of agglomerates and the value of St(Abr) was demonstrated. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. The Mars Environmental Compatibility Assessment (MECA) Abrasion Tool

    NASA Technical Reports Server (NTRS)

    Kuhlman, K. R.; Anderson, M. S.; Hinde, B. D.; Hecht, M. H.; Pike, W. T.; Marshall, J. R.; Meloy, T. P.

    1999-01-01

    The Mars Environmental Compatibility Assessment (MECA) experiment, an instrument suite to be flown on Mars Surveyor 2001, will include a tool for doing simple mineralogical scratch and streak tests on particles from the Martian regolith. The Abrasion Tool will be applied to particles that adhere themselves to highly polished substrates of various hardnesses. Granular soil components will be subjected to a compressive force of about 3 N using a leaf spring. The spring will be applied with a paraffin actuator capable of a 0.76 mm throw to achieve a maximum displacement of about 7.5 mm at the tip of the tool. The pressure per grain will be dependent on the grain size, the number of grains that adhere to the substrate and the number of grains in compression. The pressure per particle is expected to be on the order of 100 MPa - 1 GPa. The MECA sample wheel containing the substrates will be rotated after the particles are placed in compression to produce scratches or pits. A primary goal of the Abrasion Tool is to identify quartz (Mohs' hardness = 7) using substrates of varying hardnesses. Quartz is considered hazardous to future human explorers of Mars because it can cause silicosis of the lungs if it is of respirable size. It is also hazardous to machinery, structures, and space suits because of its ability to abrade and scratch surfaces. Since large quantities of minerals harder than quartz are not expected, any scratches produced on polished quartz substrates might be reasonably attributed to quartz particles, although there may be minerals such as impact metamorphic diamond in the soils. Careful calibration of the tool will be necessary to ensure that grains are not overloaded; for example, a steel ball pressed into glass will produce a Hertzian fracture, even though it is softer than glass. Other minerals, such as magnetite (Mohs' hardness = 6.5) have been shown to scratch glass ceramics such as Zerodur (Mohs' hardness = 6.5). Thus, minerals can be differentiated

  15. The Mars Environmental Compatibility Assessment MECA Abrasion Tool

    NASA Technical Reports Server (NTRS)

    Kuhlman, K. R.; Anderson, M. S.; Hinde, B. D.; Hecht, M. H.; Pike, W. T.; Marshall, J.; Meloy, T. P.; Cobbly, T.

    1999-01-01

    The Mars Environmental Compatibility Assessment (MECA) experiment, an instrument suite to be flown on Mars Surveyor 2001, will include a tool for doing simple mineralogical scratch and streak tests on particles from the Martian regolith. The Abrasion Tool will be applied to particles that adhere to highly polished substrates of various hardnesses. Granular soil components will be subjected to a compressive force of about 3 N using a leaf spring. The spring will be applied with a paraffin actuator capable of a 0.76 mm throw to achieve a maximum displacement of about 7.5 mm at the tip of the tool. The pressure per grain will be dependent on the grain size, the number of grains that adhere to the substrate and the number of grains in compression. The pressure per particle is expected to be on the order of 100 MPa - 1 GPa. The MECA sample wheel containing the substrates will be rotated after the particles are placed in compression to produce scratches or pits. A primary goal of the Abrasion Tool is to identify quartz (Mohs' hardness = 7) using substrates of varying hardnesses. Quartz is considered hazardous to future human explorers of Mars because it can cause silicosis of the lungs if it is of respirable size. It is also hazardous to machinery, structures, and space suits because of its ability to abrade and scratch surfaces. Since large quantities of minerals harder than quartz are not expected, any scratches produced on polished quartz substrates might be reasonably attributed to quartz particles, although there may be minerals such as impact metamorphic diamond in the soils. Careful calibration of the tool will be necessary to ensure that grains are not overloaded; for example, a steel ball pressed into glass will produce a Hertzian fracture, even though it is softer than glass. Other minerals, such as magnetite (Mohs'hardness = 6.5) have been shown to scratch glass ceramics such as Zerodur (Mohs' hardness = 6.5). Thus, minerals can be differentiated: note that

  16. Performance Analysis of Abrasive Waterjet Machining Process at Low Pressure

    NASA Astrophysics Data System (ADS)

    Murugan, M.; Gebremariam, MA; Hamedon, Z.; Azhari, A.

    2018-03-01

    Normally, a commercial waterjet cutting machine can generate water pressure up to 600 MPa. This range of pressure is used to machine a wide variety of materials. Hence, the price of waterjet cutting machine is expensive. Therefore, there is a need to develop a low cost waterjet machine in order to make the technology more accessible for the masses. Due to its low cost, such machines may only be able to generate water pressure at a much reduced rate. The present study attempts to investigate the performance of abrasive water jet machining process at low cutting pressure using self-developed low cost waterjet machine. It aims to study the feasibility of machining various materials at low pressure which later can aid in further development of an effective low cost water jet machine. A total of three different materials were machined at a low pressure of 34 MPa. The materials are mild steel, aluminium alloy 6061 and plastics Delrin®. Furthermore, a traverse rate was varied between 1 to 3 mm/min. The study on cutting performance at low pressure for different materials was conducted in terms of depth penetration, kerf taper ratio and surface roughness. It was found that all samples were able to be machined at low cutting pressure with varied qualities. Also, the depth of penetration decreases with an increase in the traverse rate. Meanwhile, the surface roughness and kerf taper ratio increase with an increase in the traverse rate. It can be concluded that a low cost waterjet machine with a much reduced rate of water pressure can be successfully used for machining certain materials with acceptable qualities.

  17. Tracheopleuropulmonary injuries following enteral tube insertion.

    PubMed Central

    Odocha, O.; Lowery, R. C.; Mezghebe, H. M.; Siram, S. M.; Warner, O. G.

    1989-01-01

    Eighty-three cases of tracheopleuropulmonary injuries complicating enteral tube feeding are analyzed to identify the patterns of injury, and precipitating factors and ways to avoid them. Six new cases observed by the authors and 77 other cases cited in British literature between 1976 and 1987 are presented. In recent years, reports of this complication have been increasing, apparently in a geometrical progression: 8%, 18%, and 74% were reported between 1976 to 1979, 1980 to 1983, and 1984 to 1987, respectively. Sixty-one percent occurred in patients aged 60 years or older. Most of the patients (84%) were seriously ill, which compounded their complications. Seventy-four percent of all injuries were committed by house staff; the narrow bore tube with guide wire was used in 77% of cases. Less than reliable methods were used to confirm tube position in most instances. The presence of cuffed endotracheal tubes did not offer protection. The patients on mechanical ventilation tended to deteriorate if they developed a pneumothorax once the malpositioned tubes were removed. Of the cases reviewed for this report, 18 deaths occurred; 72% being directly related to the tube injuries. Lack of awareness, inadequate confirmatory methods, and insufficient supervision accounted for most of these preventable complications. Educating house/nursing staff in the use of the new tubes, closer supervision, and the application of equal measures of care and caution as employed in other invasive and potentially dangerous procedures are recommended to avoid disastrous outcome. PMID:2496234

  18. Continuous nasogastric milk feeding versus intermittent bolus milk feeding for premature infants less than 1500 grams.

    PubMed

    Premji, Shahirose S; Chessell, Lorraine

    2011-11-09

    Milk feedings can be given via nasogastric tube either intermittently, typically over 10 to 20 minutes every two or three hours, or continuously, using an infusion pump. Although theoretical benefits and risks of each method have been proposed, effects on clinically important outcomes remain uncertain. To examine the evidence regarding the effectiveness of continuous versus intermittent bolus nasogastric milk feeding in premature infants less than 1500 grams. Searches were performed of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2011), MEDLINE, CINAHL and HealthSTAR up to July 2011. Randomised and quasi-randomised clinical trials comparing continuous versus intermittent bolus nasogastric milk feeding in premature infants less than 1500 grams. Two review authors independently assessed all trials for relevance and methodologic quality. The standard methods of the Cochrane Neonatal Review Group were used to extract data. Overall, the seven included trials, involving 511 infants, found no differences in time to achieve full enteral feeds between feeding methods (weighted mean difference (WMD) 2 days; 95% CI -0.3 to 3.9) . In the subgroup analysis of those studies comparing continuous nasogastric versus intermittent bolus nasogastric milk feedings the findings remained unchanged (WMD 2 days, 95% CI -0.4 to 4.1). There was no significant difference in somatic growth and incidence of NEC between feeding methods irrespective of tube placement. One study noted a trend toward more apneas during the study period in infants fed by the continuous tube feeding method compared to those fed by intermittent feedings delivered predominantly by orogastric tube placements [mean difference (MD) 14.0 apneas during study period; 95% CI -0.2 to 28.2]. In subgroup analysis based on weight groups, one study suggested that infants less than 1000 grams and 1000 to 1250 grams birth weight gained weight faster when fed by the continuous

  19. Torsion Tests of Tubes

    NASA Technical Reports Server (NTRS)

    Stang, Ambrose H; Ramberg, Walter; Back, Goldie

    1937-01-01

    This report presents the results of tests of 63 chromium-molybdenum steel tubes and 102 17st aluminum-alloy tubes of various sizes and lengths made to study the dependence of the torsional strength on both the dimensions of the tube and the physical properties of the tube material. Three types of failure are found to be important for sizes of tubes frequently used in aircraft construction: (1) failure by plastic shear, in which the tube material reached its yield strength before the critical torque was reached; (2) failure by elastic two-lobe buckling, which depended only on the elastic properties of the tube material and the dimensions of the tube; and (3) failure by a combination of (1) and (2) that is, by buckling taking place after some yielding of the tube material.

  20. Toothbrushing abrasion susceptibility of enamel and dentin bleached with calcium-supplemented hydrogen peroxide gel.

    PubMed

    Borges, A B; Santos, L F T F; Augusto, M G; Bonfiette, D; Hara, A T; Torres, C R G

    2016-06-01

    The objective of this study was to evaluate enamel and dentin susceptibility to toothbrushing abrasion, after bleaching with 7.5% hydrogen peroxide (HP) gel supplemented or not with 0.5% calcium gluconate (Ca). Toothbrushing was performed immediately and 1h after bleaching, with two suspensions (high and low abrasivity). Bovine enamel and dentin specimens were divided into 12 groups (n=10) according to the bleaching gel (with and without Ca), slurry abrasivity (high or low) and elapsed time after bleaching (immediately and after 1h). As control, a group was not bleached, but abraded. The treatment cycle (7 d) consisted of bleaching (1h) and toothbrushing (135 strokes/day) immediatelly or after 1h of artificial saliva exposure. Surface roughness and surface loss (μm) were measured by profilometry and analysed by three-way ANOVA (5%). Surface roughness means were significantly influenced by slurry abrasivity (p<0.0001). For enamel loss, significant triple interaction was observed (p<0.0001). HP-bleached groups and immediately brushed with high-abrasive slurry exhibited increased loss (1.41±0.14) compared to other groups (μm). Control and HP+Ca-bleached groups brushed after 1h with low abrasive slurry presented the lowest loss (0.21±0.03/0.27±0.02). For dentin loss, significant interaction was observed for bleaching and interval factors (p<0.001). 7.5%HP-bleached groups and immediately brushed showed significantly higher loss (8.71±2.45) than the other groups. It was concluded that surface roughness increased when high abrasive was used, independently of bleaching. 7.5%HP increased enamel and dentin loss, mainly with high abrasive slurries. Calcium supplementation of bleaching gel reduced surface loss. Additionally, in order to minimize tooth wear susceptibility, it is recommended to delay brushing after bleaching. After bleaching gel application, postponing toothbrushing is recommended, as well as brushing with low abrasive dentifrices. Additionally

  1. Effects of Load and Speed on Wear Rate of Abrasive Wear for 2014 Al Alloy

    NASA Astrophysics Data System (ADS)

    Odabas, D.

    2018-01-01

    In this paper, the effects of the normal load and sliding speed on wear rate of two-body abrasive wear for 2014 Al Alloy were investigated in detail. In order to understand the variation in wear behaviour with load and speed, wear tests were carried out at a sliding distance of 11 m, a speed of 0.36 m/s, a duration of 30 s and loads in the range 3-11 N using 220 grit abrasive paper, and at a speed range 0.09-0.90 m/s, a load of 5 N and an average sliding distance of 11 m using abrasive papers of 150 grit size under dry friction conditions. Before the wear tests, solution treatment of the 2014 Al alloy was carried out at temperatures of 505 and 520 °C for 1 h in a muffle furnace and then quenched in cold water at 15 °C. Later, the ageing treatment was carried out at 185 °C for 8 h in the furnace. Generally, wear rate due to time increased linearly and linear wear resistance decreased with increasing loads. However, the wear rate was directly proportional to the load up to a critical load of 7 N. After this load, the slope of the curves decreased because the excessive deformation of the worn surface and the instability of the abrasive grains began to increase. When the load on an abrasive grain reaches a critical value, the groove width is about 0.17 of the abrasive grain diameter, and the abrasive grains begin to fail. The wear rate due to time increased slightly as the sliding speed increased in the range 0.09-0.90 m/s. The reason for this is that changes arising from strain rate and friction heating are expected with increasing sliding speeds.

  2. Impact of dentifrice abrasivity and remineralization time on erosive tooth wear in vitro.

    PubMed

    Buedel, Sarah; Lippert, Frank; Zero, Domenick T; Eckert, George J; Hara, Anderson T

    2018-02-01

    To investigate the in vitro effects of simulated dentifrice slurry abrasivity (L-low, M-medium and H-high) and remineralization time (0, 30, 60 and 120 minutes) on erosive tooth wear. Enamel and root dentin specimens were prepared from bovine incisors (n= 8) and submitted to a cycling protocol including erosion, remineralization at the test times, and brushing with each of the tested slurries, for 5 days. Dental surface loss (SL) was determined by optical profilometry. Data was analyzed using mixed-model ANOVA and Fisher's PLSD tests (alpha= 0.05). SL generally increased along with the increase in slurry abrasive level, with significance dependent upon the specific substrate and remineralization times. H showed the highest SL on both enamel and dentin; remineralization for 30 minutes reduced SL significantly (P< 0.05), but only for enamel. M showed intermediate SL values, with remineralization benefit clearly seen only after 120 minutes of remineralization (P< 0.05). L caused the least SL for both enamel and dentin, which was further reduced after remineralization for 120 and 30 minutes, respectively (both P< 0.05). Overall, root dentin had significantly higher SL than enamel. Less abrasive dentifrice slurries were able to reduce toothbrushing abrasion on both enamel and root dentin. This protection was enhanced by remineralization for all abrasive levels on enamel, but only for L on root dentin. High-risk erosion patients should avoid highly abrasive toothpastes, as remineralization can only partially compensate for their deleterious effects on eroded dental surfaces. Lower abrasive toothpastes are recommended. Copyright©American Journal of Dentistry.

  3. Investigating selective transport and abrasion on an alluvial fan using quantitative grain size and shape analysis

    NASA Astrophysics Data System (ADS)

    Litwin, K. L.; Jerolmack, D. J.

    2011-12-01

    Selective sorting and abrasion are the two major fluvial processes that are attributed to the downstream fining of sediments in rivers and alluvial fans. Selective transport is the process by which smaller grains are preferentially transported downstream while larger grains are deposited closer to the source. Abrasion is defined by the production of fine sediments and sand that occurs by saltation of gravel, where particle-to-particle collisions supply the energy required to break apart grains. We hypothesize that abrasion results in the gradual fining of large grains and the production of fine sands and silts, while sorting accounts for the differences in transport of these two grain-size fractions produced from abrasion, thereby creating the abrupt gravel-sand transition observed in many channel systems. In this research, we explore both selective transport and abrasion processes on the Dog Canyon alluvial fan near Alamogordo, New Mexico. We complete an extensive grain size analysis down the main channel of the fan employing an image-based technique that utilizes an autocorrelation process. We also characterize changes in grain shape using standard shape parameters, as well as Fourier analysis, which allows the study of contributions of grain roughness on a variety of length scales. Sorting appears to dominate the upper portion of the fan; the grain-size distribution narrows moving downstream until reaching a point of equal mobility, at which point sorting ceases. Abrasion exerts a subtle but persistent effect on grains during transport down the fan. Shape analysis reveals that particles become more rounded by the removal of small-scale textural features, a process that is expected to only modestly influence grain size of gravel, but should produce significant quantities of sand. This study provides a better understanding of the importance of grain abrasion and sorting on the downstream fining of channel grains in an alluvial fan, as well as an improved knowledge

  4. [Polyethylene abrasion: cause or consequence of an endoprosthesis loosening? Investigations of firm and loosened hip implants].

    PubMed

    Busse, B; Niecke, M; Püschel, K; Delling, G; Katzer, A; Hahn, M

    2007-01-01

    Periprosthetic tissue was analysed by the combination of different investigation techniques without destruction. The localisation and geometry of polyethylene abrasion particles were determined quantitatively to differentiate between abrasion due to function and abrasion due to implant loosening. Non-polyethylene particles from implant components which contaminate the tissue were micro-analytically measured. The results will help us to understand loosening mechanisms and thus lead to implant optimisations. A non-destructive particle analysis using highly sensitive proton-induced X-ray emission (PIXE) was developed to achieve a better histological allocation. Five autopsy cases with firmly fitting hip endoprosthesis (2 x Endo-Modell Mark III, 1 x St. Georg Mark II, LINK, Germany; 2 x Spongiosa Metal II, ESKA, Germany) were prepared as ground tissue specimens. Wear investigations were accomplished with a combined application of different microscopic techniques and microanalysis. The abrasion due to implant loosening was histologically evaluated on 293 loosened cup implants (St. Georg Mark II, LINK, Germany). Wear particles are heterogeneously distributed in the soft tissue. In cases of cemented prostheses, cement particles are dominating whereas metal particles could rarely be detected. The concentration of the alloy constituent cobalt (Co) is increased in the mineralised bone tissue. The measured co-depositions depend on the localisation and/or lifetime of an implant. Functional polyethylene (PE) abrasion needs to be differentiated from PE abrasion of another genesis (loosening, impingement) morphologically and by different tissue reactions. In the past a reduction of abrasion was targeted primarily by the optimisation of the bearing surfaces and tribology. The interpretation of our findings indicates that different mechanisms of origin in terms of tissue contamination with wear debris and the alloy should be included in the improvement of implants or implantation

  5. Oral Feeding Outcome after Analgesic and Sedative Exposure in VLBW Preterm Infant.

    PubMed

    Astoria, Mark T; Thacker, Leroy; Hendricks-Muñoz, Karen D

    2018-06-08

     The objective of this study was to assess the association of analgesics and sedatives on oral feeding function and need for feeding tube at discharge in the very low birth weight (VLBW) (<1,500 g) preterm infant.  A retrospective review of surviving inborn infants < 1,500 g and < 32 weeks' gestation ( n  = 209), discharged between January 1, 2012, and December 31, 2014, from the neonatal intensive care unit identified exposure to analgesic and sedative medications, demographics, medical course, and nasogastric or gastrostomy tube (GT) feeding at discharge. Predictive modeling with logistic regression to identify independent factors associated with discharge on tube feedings.  Out of 209, 45 (21.5%) infants received an analgesic/sedative with 23 out of 45 (51.1%) discharged with tube feedings. Infants discharged with tube feedings were born smaller, of younger gestation, with greater SNAPPE-II scores, periventricular leukomalacia, chronic lung disease, postnatal glucocorticoids, lansoprazole, and longer time intubated. After adjusting for covariates, exposure to analgesic/sedatives (fentanyl, midazolam, or morphine) was independently predictive of discharge on tube feedings.  Analgesic and sedative exposure in VLBW infants is highly associated with poor oral feeding and need for tube feedings at discharge. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  6. A profilometry-based dentifrice abrasion Method for V8 brushing machines. Part I: Introduction to RDA-PE.

    PubMed

    White, Donald J; Schneiderman, Eva; Colón, Ellen; St John, Samuel

    2015-01-01

    This paper describes the development and standardization of a profilometry-based method for assessment of dentifrice abrasivity called Radioactive Dentin Abrasivity - Profilometry Equivalent (RDA-PE). Human dentine substrates are mounted in acrylic blocks of precise standardized dimensions, permitting mounting and brushing in V8 brushing machines. Dentin blocks are masked to create an area of "contact brushing." Brushing is carried out in V8 brushing machines and dentifrices are tested as slurries. An abrasive standard is prepared by diluting the ISO 11609 abrasivity reference calcium pyrophosphate abrasive into carboxymethyl cellulose/glycerin, just as in the RDA method. Following brushing, masked areas are removed and profilometric analysis is carried out on treated specimens. Assessments of average abrasion depth (contact or optical profilometry) are made. Inclusion of standard calcium pyrophosphate abrasive permits a direct RDA equivalent assessment of abrasion, which is characterized with profilometry as Depth test/Depth control x 100. Within the test, the maximum abrasivity standard of 250 can be created in situ simply by including a treatment group of standard abrasive with 2.5x number of brushing strokes. RDA-PE is enabled in large part by the availability of easy-to-use and well-standardized modern profilometers, but its use in V8 brushing machines is enabled by the unique specific conditions described herein. RDA-PE permits the evaluation of dentifrice abrasivity to dentin without the requirement of irradiated teeth and infrastructure for handling them. In direct comparisons, the RDA-PE method provides dentifrice abrasivity assessments comparable to the gold industry standard RDA technique.

  7. Use of an esophagostomy tube as a method of nutritional management in raptors: a case series.

    PubMed

    Huynh, Minh; Sabater, Mikel; Brandão, João; Forbes, Neil A

    2014-03-01

    We determined if esophagostomy tube placement is feasible for nutritional support in raptors. The clinical data were reviewed from 18 raptors admitted between 2006 and 2012, and in which esophagostomy tubes were placed. Indications for tube placement, complications associated with its placement and management, duration of treatment, and changes in patient body weight were evaluated. The most common indication was nutritional and medical support in stressed hospitalized animals, and intensive care cases. Complications were regurgitation, unexpected removal, and misplacement of the tube. The esophagostomy tube was well tolerated in all but 2 cases. A tube was replaced once in 2 patients. Five birds died during the treatment course. Mortality was not associated with the placement of the tube. Average duration of tube placement was 6.1 +/- 3.7 days. Most birds did not gain any weight with use of the feeding tubes. Esophagostomy tubes are well tolerated in raptors, but further studies are needed to demonstrate their efficiency.

  8. Neural Tube Defects

    MedlinePlus

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  9. Chest Tube Thoracostomy

    MedlinePlus

    ... outside the lung, causing its collapse (called a pneumothorax ). Chest tube thoracostomy involves placing a hollow plastic ... a chest tube is needed include: ■ ■ Collapsed lung (pneumothorax)— This occurs when air has built up in ...

  10. Tracheostomy tube - speaking

    MedlinePlus

    ... most of the air from passing through your vocal cords. Instead, your breath (air) goes out through your tracheostomy tube (trach). At the time of your surgery, the first trach tube will have a balloon ( ...

  11. Fluoroscopically guided nose tube drainage of mediastinal abscesses in post-operative gastro-oesophageal anastomotic leakage.

    PubMed

    Xu, Q Y; Yin, G W; Chen, S X; Jiang, F; Bai, X J; Wu, J D

    2012-11-01

    The aim of this study was to retrospectively evaluate the technical success rates and clinical effectiveness of fluoroscopically guided nose tube drainage of mediastinal abscesses and a nasojejunum feeding tube in post-operative gastro-oesophageal anastomotic leakage (GEAL). From January 2006 to June 2011, 18 cases of post-operative GEAL with mediastinal abscesses after oesophagectomy with intrathoracic oesophagogastric anastomotic procedures for oesophageal and cardiac carcinoma were treated by insertion of a nose drainage tube and nasojejunum feeding tube under fluoroscopic guidance. We evaluated the feasibility of two-tube insertion to facilitate leakage site closure and complete resolution of the abscess, and the patients' nutritional benefit was also evaluated by checking the serum albumin level between pre- and post-enteral feeding via the feeding tube. The two tubes were placed successfully under fluoroscopic guidance in 18 patients (100%). The procedure time for two-tube insertion ranged from 20 to 40 min (mean 30 min). 17 patients (94%) achieved leakage site closure after two-tube insertion and had a good tolerance of two tubes in the nasal cavity. The serum albumin level was significant, increased from pre-enteral feeding (2.49 ± 0.42 g dl(-1)) to the post-enteral feeding (3.58 ± 0.47 g dl(-1)) via the feeding tube (p<0.001). The duration of follow-up ranged from 1 to 49 months (mean 19 months). The insertion of nose tube drainage and a nasojejunum feeding tube under fluoroscopic guidance is safe, and it provides effective relief from mediastinal abscesses in GEAL after oesophagectomy. Moreover, our findings indicate that two-tube insertion may be used as a selective procedure to treat mediastinal abscesses in post-operative GEAL. Advances in knowledge Directive drainage of mediastinal abscesses in post-operative GEAL may be an effective treatment.

  12. 46 CFR 56.50-30 - Boiler feed piping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... least two separate means of supplying feed water for the boilers. All feed pumps shall be fitted with... allowable stress for design purposes shall be selected as described in § 56.07-10(e) at a temperature not... for water tube boilers shall have fresh water connections only. Care shall be taken to prevent the...

  13. 46 CFR 56.50-30 - Boiler feed piping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... least two separate means of supplying feed water for the boilers. All feed pumps shall be fitted with... allowable stress for design purposes shall be selected as described in § 56.07-10(e) at a temperature not... for water tube boilers shall have fresh water connections only. Care shall be taken to prevent the...

  14. Comparative evaluation of enamel abrasivity by toothbrush and velcro: An in vitro scanning electron microscope study

    PubMed Central

    Ojha, Saroj Kumar; Javdekar, Sadashiv Bhaskar; Dhir, Sangeeta

    2015-01-01

    Context: Plaque control has been shown to be pivotal in maintaining the optimal periodontal health. Mechanical plaque control is the most popular option for establishing the optimal oral health. Toothbrushes have been the novel tool for mechanical cleansing. However, the abrasive potential of the toothbrushes on the enamel surface is an area in gray. Aims: The aim of this in vitro study is to evaluate the abrasivity of the toothbrush versus the velcro fasteners. Materials and Methods: The mounted teeth of both the groups were subjected to abrasion test, and the tooth surfaces were observed for the possible abrasions from the oscillating strokes (toothbrush) and frictional contacts (hook and loop velcro) and examined under the scanning electron microscope. Results: Comparative assessment of both velcro (hook and loop) and toothbrush bristles did not reveal any evidence of abrasion on the tooth specimens. Conclusions: Veclro fasteners are safe and qualitatively at par to the manual toothbrush for their efficacy and efficiency in teeth cleansing PMID:26229264

  15. Air powder abrasive treatment as an implant surface cleaning method: a literature review.

    PubMed

    Tastepe, Ceylin S; van Waas, Rien; Liu, Yuelian; Wismeijer, Daniel

    2012-01-01

    To evaluate the air powder abrasive treatment as an implant surface cleaning method for peri-implantitis based on the existing literature. A PubMed search was conducted to find articles that reported on air powder abrasive treatment as an implant surface cleaning method for peri-implantitis. The studies evaluated cleaning efficiency and surface change as a result of the method. Furthermore, cell response toward the air powder abrasive-treated discs, reosseointegration, and clinical outcome after treatment is also reported. The PubMed search resulted in 27 articles meeting the inclusion criteria. In vitro cleaning efficiency of the method is reported to be high. The method resulted in minor surface changes on titanium specimens. Although the air powder abrasive-treated specimens showed sufficient levels of cell attachment and cell viability, the cell response decreased compared with sterile discs. Considerable reosseointegration between 39% and 46% and improved clinical parameters were reported after treatment when applied in combination with surgical treatment. The results of the treatment are influenced by the powder type used, the application time, and whether powder was applied surgically or nonsurgically. The in vivo data on air powder abrasive treatment as an implant surface cleaning method is not sufficient to draw definitive conclusions. However, in vitro results allow the clinician to consider the method as a promising option for implant surface cleaning in peri-implantitis treatment.

  16. A Study on Postmortem Wound Dating by Gross and Histopathological Examination of Abrasions

    PubMed Central

    Vinay, Javaregowda; Harish, Sathyanarayana; Mangala, Gouri S.R.; Hugar, Basappa S.

    2017-01-01

    Introduction Abrasions are the most common blunt force injuries. The precise dating of injury is extremely important in forensic medicine practice. As we know, the wound healing occurs in well-orchestrated sequence, consisting of inflammation, proliferation, and maturation. A study of occurrence of such phases will help in understanding the sequence of events in wound healing. In this context, this study of wound dating from gross and microscopic level was taken. Materials and Methods Postmortem study of wound dating by gross and histopathological examination of abrasions was carried out in the Department of Forensic Medicine, in M.S. Ramaiah Medical College. A total of 101 abrasions were correlated to time frame the occurrence of different gross changes and microscopic changes that follow the blunt trauma. Abrasions ranging from 0 hour to a maximum of 45 days were studied. Results The gross changes of abrasions were in correlation with the microscopic changes; however, the role of the comorbid conditions is significant because the results showed variations with respect to healing process. Conclusions This study signifies that, if naked eye examination is studied along with histopathological examination, the reliability and accuracy of dating of wound increase. Whenever accurate determination of age is required, the autopsy surgeon can subject the samples for histopathological examination and correlate before opining the age of injury. PMID:28418938

  17. Micro-Abrasion Wear Resistance of Borided 316L Stainless Steel and AISI 1018 Steel

    NASA Astrophysics Data System (ADS)

    Reséndiz-Calderon, C. D.; Rodríguez-Castro, G. A.; Meneses-Amador, A.; Campos-Silva, I. E.; Andraca-Adame, J.; Palomar-Pardavé, M. E.; Gallardo-Hernández, E. A.

    2017-11-01

    The 316L stainless steel has high corrosion resistance but low tribological performance. In different industrial sectors (biomedical, chemical, petrochemical, and nuclear engineering), improvement upon wear resistance of 316L stainless steel components using accessible and inexpensive methods is critical. The AISI 1018 steel is widely used in industry, but its tribological performance is not the best among steels. Therefore, in this study the behavior of the borided 316L stainless steel and 1018 steel is evaluated under micro-abrasion wear. The boriding was carried out at 1223 K over 6 h of exposure time, resulting in a biphase layer composed of FeB/Fe2B phases. In order to evaluate Fe2B phase with no influence from FeB phase, AISI 1018 steel samples were borided at 1273 K for over 20 min and then diffusion annealed at 1273 K over 2 h to obtain a Fe2B mono-phase layer. Micro-abrasion wear resistance was evaluated by a commercial micro-abrasion testing rig using a mix of F-1200 SiC particles with deionized water as abrasive slurry. The obtained wear rates for FeB and Fe2B phases and for the 316L stainless steel were compared. Wear resistance of 316L stainless steel increases after boriding. The wear mechanisms for both phases and for the stainless steel were identified. Also, transient conditions for rolling and grooving abrasion were determined for the FeB and Fe2B phases.

  18. A Study on Postmortem Wound Dating by Gross and Histopathological Examination of Abrasions.

    PubMed

    Vinay, Javaregowda; Harish, Sathyanarayana; Mangala, Gouri S R; Hugar, Basappa S

    2017-06-01

    Abrasions are the most common blunt force injuries. The precise dating of injury is extremely important in forensic medicine practice. As we know, the wound healing occurs in well-orchestrated sequence, consisting of inflammation, proliferation, and maturation.A study of occurrence of such phases will help in understanding the sequence of events in wound healing. In this context, this study of wound dating from gross and microscopic level was taken. Postmortem study of wound dating by gross and histopathological examination of abrasions was carried out in the Department of Forensic Medicine, in M.S. Ramaiah Medical College. A total of 101 abrasions were correlated to time frame the occurrence of different gross changes and microscopic changes that follow the blunt trauma. Abrasions ranging from 0 hour to a maximum of 45 days were studied. The gross changes of abrasions were in correlation with the microscopic changes; however, the role of the comorbid conditions is significant because the results showed variations with respect to healing process. This study signifies that, if naked eye examination is studied along with histopathological examination, the reliability and accuracy of dating of wound increase. Whenever accurate determination of age is required, the autopsy surgeon can subject the samples for histopathological examination and correlate before opining the age of injury.

  19. Computational Fluid Dynamic Simulation of Flow in Abrasive Water Jet Machining

    NASA Astrophysics Data System (ADS)

    Venugopal, S.; Sathish, S.; Jothi Prakash, V. M.; Gopalakrishnan, T.

    2017-03-01

    Abrasive water jet cutting is one of the most recently developed non-traditional manufacturing technologies. In this machining, the abrasives are mixed with suspended liquid to form semi liquid mixture. The general nature of flow through the machining, results in fleeting wear of the nozzle which decrease the cutting performance. The inlet pressure of the abrasive water suspension has main effect on the major destruction characteristics of the inner surface of the nozzle. The aim of the project is to analyze the effect of inlet pressure on wall shear and exit kinetic energy. The analysis could be carried out by changing the taper angle of the nozzle, so as to obtain optimized process parameters for minimum nozzle wear. The two phase flow analysis would be carried by using computational fluid dynamics tool CFX. It is also used to analyze the flow characteristics of abrasive water jet machining on the inner surface of the nozzle. The availability of optimized process parameters of abrasive water jet machining (AWJM) is limited to water and experimental test can be cost prohibitive. In this case, Computational fluid dynamics analysis would provide better results.

  20. Cracking of porcelain surfaces arising from abrasive grinding with a dental air turbine.

    PubMed

    Chang, Chee W; Waddell, J Neil; Lyons, Karl M; Swain, Michael V

    2011-12-01

    The purpose of this in vitro study was to evaluate porcelain cracking induced by abrasive grinding with a conventional dental air turbine and abrasive diamond burs. Four commercially available porcelains were examined-Wieland ALLUX, Wieland ZIROX, IPS e.max Ceram, and IPS Empress Esthetic Veneering porcelain. Sixty discs of each porcelain type were fabricated according to manufacturer instructions, followed by an auto-glaze cycle. Abrasive grinding using fine, extra-fine, and ultra-fine diamond burs was carried out, using a conventional dental air turbine. The grinding parameters were standardized with regard to the magnitude of the force applied, rotational speed of the diamond bur, and flow rate of the water coolant. A testing apparatus was used to control the magnitude of force applied during the grinding procedure. The ground surfaces were then examined under scanning electron microscope. Cracking was seen for all porcelain types when ground with the fine bur. Cracking was not seen for specimens ground with the extra-fine or the ultra-fine bur. Wet abrasive grinding with a conventional dental air turbine and fine grit diamond burs has the potential to cause cracking in the four porcelain types tested. Similar abrasive grinding with smaller grit size particles does not cause similar observable cracking. © 2011 by the American College of Prosthodontists.

  1. Finishing of display glass for mobile electronics using 3M Trizact diamond tile abrasive pads

    NASA Astrophysics Data System (ADS)

    Zheng, Lianbin; Fletcher, Tim; Na, Tee Koon; Sventek, Bruce; Romero, Vince; Lugg, Paul S.; Kim, Don

    2010-10-01

    This paper will describe a new method being used during the finishing of glass displays for mobile electronics including mobile hand held devices and notebook computers. The new method consists of using 3M TrizactTM Diamond Tile Abrasive Pads. TrizactTM Diamond Tile is a structured fixed abrasive grinding technology developed by 3M Company. The TrizactTM Diamond Tile structured abrasive pad consists of an organic (polymeric binder) - inorganic (abrasive mineral, i.e., diamond) composite that is used with a water-based coolant. TrizactTM Diamond Tile technology can be applied in both double and single side grinding applications. A unique advantage of TrizactTM Diamond Tile technology is the combination of high stock removal and low sub-surface damage. Grinding results will be presented for both 9 micron and 20 micron grades of TrizactTM Diamond Tile abrasive pads used to finish several common display glasses including Corning GorillaTM glass and Soda Lime glass.

  2. Dependence of Non-Prestonian Behavior of Ceria Slurry with Anionic Surfactant on Abrasive Concentration and Size in Shallow Trench Isolation Chemical Mechanical Polishing

    NASA Astrophysics Data System (ADS)

    Kang, Hyun‑Goo; Kim, Dae‑Hyeong; Katoh, Takeo; Kim, Sung‑Jun; Paik, Ungyu; Park, Jea‑Gun

    2006-05-01

    The dependencies of the non-Prestonian behavior of ceria slurry with anionic surfactant on the size and concentration of abrasive particles were investigated by performing chemical mechanical polishing (CMP) experiments using blanket wafers. We found that not only the abrasive size but also the abrasive concentration with surfactant addition influences the non-Prestonian behavior. Such behavior is clearly exhibited with small abrasive sizes and a higher concentrations of abrasives with surfactant addition, because the abrasive particles can locally contact the film surface more effectively with applied pressure. We introduce a factor to quantify these relations with the non-Prestonian behavior of a slurry. For ceria slurry, this non-Prestonian factor, βNP, was determined to be almost independent of the abrasive concentration for a larger size and a smaller weight conentration of abrasive particles, but it increased with the surfactant concentration for a smaller size and a higher concentration of abrasives with surfactant addition.

  3. Artificial feeding--solid ground, not a slippery slope.

    PubMed

    Steinbrook, R; Lo, B

    1988-02-04

    Decisions about artificial feeding arouse more controversy than those involving any other life-sustaining treatment. Because food and water are generally considered basic elements of humane care, representing love and concern for the helpless, it is often thought that they must always be provided. In a landmark decision, the Supreme Judicial Court of Massachusetts ruled that a feeding tube could be removed from a patient in a persistent vegetative state if this was consistent with his previously expressed wishes. The case of Paul E. Brophy, Sr., is part of an emerging medical and legal consensus on the withholding of artificial feeding from adult patients. The view is growing that tube and intravenous feeding should be likened to other medical interventions and not to the routine provision of nursing care or comfort. Competent patients have the right to refuse such feeding. Feeding can also be stopped incompetent patients who have earlier stated such a wish.

  4. PEG tube insertion -- discharge

    MedlinePlus

    ... be treated with medicine. Caring for the PEG-tube Site Drainage from around the PEG tube is common for the first 1 or 2 ... cotton swab or gauze. Try to remove any drainage or crusting on the skin and tube. Be gentle. If you used soap, gently clean ...

  5. Microhole Tubing Bending Report

    DOE Data Explorer

    Oglesby, Ken

    2012-01-01

    A downhole tubing bending study was made and is reported herein. IT contains a report and 2 excel spreadsheets to calculate tubing bending and to estimate contact points of the tubing to the drilled hole wall (creating a new support point).

  6. REACTOR COOLANT TUBE SEAL

    DOEpatents

    Morris, W.J.

    1958-12-01

    A plle-flattenlng control element and a fluid seal therefore to permit movement of the element into a liquld contnining region of a neutronlc reactor are described. The device consists of flattened, thin-walled aluminum tubing contalnlng a uniform mixture of thermal neutron absorbing material, and a number of soft rubber closures for the process tubes, having silts capable of passing the flattened elements therethrough, but effectively sealing the process tubes against fluld leaknge by compression of the rubber. The flattened tubing is sufficiently flexible to enable it to conform to the configuratlon of the annular spacing surrounding the fuel elements ln the process tubes.

  7. Telescoping tube assembly

    NASA Technical Reports Server (NTRS)

    Sturm, Albert J. (Inventor); Marrinan, Thomas E. (Inventor)

    1995-01-01

    An extensible and retractable telescoping tube positions test devices that inspect large stationary objects. The tube has three dimensional adjustment capabilities and is vertically suspended from a frame. The tube sections are independently supported with each section comprising U-shaped housing secured to a thicker support plate. Guide mechanisms preferably mounted only to the thicker plates guide each tube section parallel to a reference axis with improved accuracy so that the position of the remote end of the telescoping tube is precisely known.

  8. Pre-polishing on a CNC platform with bound abrasive contour tools

    NASA Astrophysics Data System (ADS)

    Schoeffer, Adrienne E.

    2003-05-01

    Deterministic micorgrinding (DMG) of optical glasses and ceramics is the commercial manufacturing process of choice to shape glass surfaces prior to final finishing. This process employs rigid bound matrix diamond tooling resulting in surface roughness values of 3-51.tm peak to valley and 100-400nm rms, as well as mid-spatial frequency tool marks that require subsequent removal in secondary finishing steps. The ability to pre-polish optical surfaces within the grinding platform would reduce final finishing process times. Bound abrasive contour wheels containing cerium oxide, alumina or zirconia abrasives were constructed with an epoxy matrix. The effects of abrasive type, composition, and erosion promoters were examined for tool hardness (Shore D), and tested with commercial optical glasses in an OptiproTM CNC grinding platform. Metrology protocols were developed to examine tool wear and subsequent surface roughness. Work is directed to demonstrating effective material removal, improved surface roughness and cutter mark removal.

  9. Abrasive wear behavior of in-situ RZ5-10wt%TiC composite

    NASA Astrophysics Data System (ADS)

    Mehra, Deepak; Mahapatra, M. M.; Harsha, S. P.

    2018-05-01

    RZ5 Magnesium alloys containing zinc, rare earth and zirconium are well-known to have high specific strength, good creep resistance widely used in aerospace components. The incorporation of hard ceramic strengthens RZ5 mg alloy. The RZ5-10wt%TiC composite has been fabricated in situ using RZ5 mg alloy as matrix and TiC as reinforcement by self propagating high temperature synthesis (SHS) technique. This paper investigates the abrasive wear behavior of RZ5-10wt%TiC. Tests were performed using pin-on-disc apparatus against 600 grit abrasive paper by varying the sliding distance and applied load. The results showed improvement in the wear resistance of testing composite as compared to the unreinforced RZ5 Mg alloy. The coefficient of friction and weight loss increased linearly as applied load and sliding distance increased. The field emission scanning electron microscopic (FESEM) showed dominate wear mechanisms: abrasion, ploughing grooves.

  10. Computational Fluid Dynamics Analysis of Nozzle in Abrasive Water Jet Machining

    NASA Astrophysics Data System (ADS)

    Venugopal, S.; Chandresekaran, M.; Muthuraman, V.; Sathish, S.

    2017-03-01

    Abrasive water jet cutting is one of the most recently developed non-traditional manufacturing technologies. The general nature of flow through the machining, results in rapid wear of the nozzle which decrease the cutting performance. It is well known that the inlet pressure of the abrasive water suspension has main effect on the erosion characteristics of the inner surface of the nozzle. The objective of the project is to analyze the effect of inlet pressure on wall shear and exit kinetic energy. The analysis would be carried out by varying the inlet pressure of the nozzle, so as to obtain optimized process parameters for minimum nozzle wear. The two phase flow analysis would be carried by using computational fluid dynamics tool CFX. The availability of minimized process parameters such as of abrasive water jet machining (AWJM) is limited to water and experimental test can be cost prohibitive.

  11. The rock abrasion record at Gale Crater: Mars Science Laboratory results from Bradbury Landing to Rocknest

    USGS Publications Warehouse

    Bridges, N.T.; Calef, F.J.; Hallett, B.W.; Herkenhoff, Kenneth E.; Lanza, N.L.; Le Mouélic, S.; Newman, C.E.; Blaney, D.L.; de Pablo, M.A.; Kocurek, G.A.; Langevin, Y.; Lewis, K.W.; Mangold, N.; Maurice, S.; Meslin, P.-Y.; Pinet, P.; Renno, N.O.; Rice, CM.S.; Richardson, M.E.; Sautter, V.; Sletten, R.S.; Wiens, R.C.; Yingst, R.A.

    2014-01-01

    Ventifacts, rocks abraded by wind-borne particles, are found in Gale Crater, Mars. In the eastward drive from “Bradbury Landing” to “Rocknest,” they account for about half of the float and outcrop seen by Curiosity's cameras. Many are faceted and exhibit abrasion textures found at a range of scales, from submillimeter lineations to centimeter-scale facets, scallops, flutes, and grooves. The drive path geometry in the first 100 sols of the mission emphasized the identification of abrasion facets and textures formed by westerly flow. This upwind direction is inconsistent with predictions based on models and the orientation of regional dunes, suggesting that these ventifact features formed from very rare high-speed winds. The absence of active sand and evidence for deflation in the area indicates that most of the ventifacts are fossil features experiencing little abrasion today.

  12. Photodetector Development for the Wheel Abrasion Experiment on the Sojourner Microrover of the Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Wilt, David M.; Jenkins, Phillip P.; Scheiman, David A.

    1997-01-01

    On-board the Mars Pathfinder spacecraft, launched in December of 1996, is a small roving vehicle named Sojourner. On Sojourner is an experiment to determine the abrasive characteristics of the Martian surface, called the Wheel Abrasion Experiment (WAE). The experiment works as follows: one of the wheels of the rover has a strip of black anodized aluminum bonded to the tread. The aluminum strip has thin coatings of aluminum, nickel and platinum deposited in patches. There are five (5) patches or samples of each metal, and the patches range in thickness from 200 A to 1000 A. The different metals were chosen for their differing hardness and their environmental stability. As the wheel is spun in the Martian soil, the thin patches of metal are abraded away, exposing the black anodization. The abrasion is monitored by measuring the amount of light reflected off of the samples. A photodetector was developed for this purpose, and that is the subject of this paper.

  13. Abrasion-ablation model for neutron production in heavy ion reactions

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wilson, John W.; Townsend, Lawrence W.

    1995-01-01

    In heavy ion reactions, neutron production at forward angles is observed to occur with a Gaussian shape that is centered near the beam energy and extends to energies well above that of the beam. This paper presents an abrasion-ablation model for making quantitative predictions of the neutron spectrum. To describe neutrons produced from the abrasion step of the reaction where the projectile and target overlap, the authors use the Glauber model and include effects of final-state interactions. They then use the prefragment mass distribution from abrasion with a statistical evaporation model to estimate the neutron spectrum resulting from ablation. Measurements of neutron production from Ne and Nb beams are compared with calculations, and good agreement is found.

  14. Heat tube device

    NASA Technical Reports Server (NTRS)

    Khattar, Mukesh K. (Inventor)

    1990-01-01

    The present invention discloses a heat tube device through which a working fluid can be circulated to transfer heat to air in a conventional air conditioning system. The heat tube device is disposable about a conventional cooling coil of the air conditioning system and includes a plurality of substantially U-shaped tubes connected to a support structure. The support structure includes members for allowing the heat tube device to be readily positioned about the cooling coil. An actuatable adjustment device is connected to the U-shaped tubes for allowing, upon actuation thereof, for the heat tubes to be simultaneously rotated relative to the cooling coil for allowing the heat transfer from the heat tube device to air in the air conditioning system to be selectively varied.

  15. Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits

    NASA Technical Reports Server (NTRS)

    Mitchell, Kathryn

    2009-01-01

    During the Apollo program, the space suit outer layer fabrics were severely abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub-layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, shares the results of the testing, and provides recommendations for future work.

  16. Impact Capacity Reduction in Railway Prestressed Concrete Sleepers with Surface Abrasions

    NASA Astrophysics Data System (ADS)

    Ngamkhanong, Chayut; Li, Dan; Kaewunruen, Sakdirat

    2017-10-01

    Railway sleepers (also called ‘railroad tie’ in North America) embedded in ballasted railway tracks are a main part of railway track structures. Its important role is to transfer the loads evenly from the rails to a wider area of ballast bed and to secure rail gauge and enable safe passages of rolling stocks. By nature, railway infrastructure is nonlinear, evidenced by its behaviours, geometry and alignment, wheel-rail contact and operational parameters such as tractive efforts. Based on our critical review, the dynamic behaviour of railway sleepers has not been fully investigated, especially when the sleepers are deteriorated by excessive wears. In fact, the ballast angularity causes differential abrasions on the soffit or bottom surface of sleepers (especially at railseat zone). Furthermore, in sharp curves and rapid gradient change, longitudinal and lateral dynamics of rails increase the likelihood of railseat abrasions in concrete sleepers due to the unbalanced loading conditions. This paper presents a structural capacity of concrete sleepers under dynamic transient loading. The modified compression field theory for ultimate strength design of concrete sleepers under impact loading will be highlighted in this study. The influences of surface abrasions, including surface abrasion and soffit abrasion, on the dynamic behaviour of prestressed concrete sleepers, are firstly highlighted. The outcome of this study will improve the rail maintenance and inspection criteria in order to establish appropriate and sensible remote track condition monitoring network in practice. Moreover, this study will also improve the understanding of the fundamental dynamic behaviour of prestressed concrete sleepers with surface abrasions. The insight into these behaviours will not only improve safety and reliability of railway infrastructure but will enhance the structural safety of other concrete structures.

  17. Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits

    NASA Technical Reports Server (NTRS)

    Mitchell, Kathryn C.

    2010-01-01

    During the Apollo program, the space suit outer layer fabrics were badly abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub -layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This Paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, and shares the results and conclusions of the testing.

  18. Brushing force of manual and sonic toothbrushes affects dental hard tissue abrasion.

    PubMed

    Wiegand, Annette; Burkhard, John Patrik Matthias; Eggmann, Florin; Attin, Thomas

    2013-04-01

    This study aimed to determine the brushing forces applied during in vivo toothbrushing with manual and sonic toothbrushes and to analyse the effect of these brushing forces on abrasion of sound and eroded enamel and dentin in vitro. Brushing forces of a manual and two sonic toothbrushes (low and high frequency mode) were measured in 27 adults before and after instruction of the respective brushing technique and statistically analysed by repeated measures analysis of variance (ANOVA). In the in vitro experiment, sound and eroded enamel and dentin specimens (each subgroup n = 12) were brushed in an automatic brushing machine with the respective brushing forces using a fluoridated toothpaste slurry. Abrasion was determined by profilometry and statistically analysed by one-way ANOVA. Average brushing force of the manual toothbrush (1.6 ± 0.3 N) was significantly higher than for the sonic toothbrushes (0.9 ± 0.2 N), which were not significantly different from each other. Brushing force prior and after instruction of the brushing technique was not significantly different. The manual toothbrush caused highest abrasion of sound and eroded dentin, but lowest on sound enamel. No significant differences were detected on eroded enamel. Brushing forces of manual and sonic toothbrushes are different and affect their abrasive capacity. Patients with severe tooth wear and exposed and/or eroded dentin surfaces should use sonic toothbrushes to reduce abrasion, while patients without tooth wear or with erosive lesions confining only to enamel do not benefit from sonic toothbrushes with regard to abrasion.

  19. Impact of brushing force on abrasion of acid-softened and sound enamel.

    PubMed

    Wiegand, A; Köwing, L; Attin, T

    2007-11-01

    The study aimed to analyse the effects of different brushing loads on abrasion of acid-softened and sound enamel surfaces. Sound and acid-softened surfaces of each 10 human enamel samples were submitted to brushing abrasion in an automatic brushing machine at 1.5 N (A), 2.5 N (B), 3.5 N (C) or 4.5 N (D) brushing load. Prior to abrasion, demineralisation of half of each enamel surface was performed by storage in hydrochloric acid (pH 2.0) for 60s. Brushing was carried out (1000 strokes) using a manual toothbrush and toothpaste slurry in a ratio of 1:3. Enamel loss was measured after 10, 20, 50, 100, 150, 200, 250, 300, 350 and 1000 brushing strokes (BS). Pre- and post-brushing values of Knoop indentation length (5 indentations each sample) were measured and mean enamel loss was calculated from the change in indentation depth. Within- and between-group comparisons were performed by ANOVA and t-test followed by Bonferroni-correction. Enamel loss of acid-softened surfaces was significantly influenced by the brushing load applied and was mostly significantly higher in group D (10-1000 BS: 225-462 nm) compared to A (10-1000 BS: 164-384), B (10-1000 BS: 175-370 nm) and C (10-1000 BS: 191-396 nm). Abrasion of acid-softened enamel was fourfold higher compared to sound surfaces. Sound enamel was significantly influenced by the brushing force at 20-200 brushing strokes only, but revealed no significant differences between groups A-D. Brushing load influences abrasion of briefly eroded enamel, but might be of minor importance for abrasion of sound enamel surfaces.

  20. Intercostal drainage tube or intracardiac drainage tube?

    PubMed

    Anitha, N; Kamath, S Ganesh; Khymdeit, Edison; Prabhu, Manjunath

    2016-01-01

    Although insertion of chest drain tubes is a common medical practice, there are risks associated with this procedure, especially when inexperienced physicians perform it. Wrong insertion of the tube has been known to cause morbidity and occasional mortality. We report a case where the left ventricle was accidentally punctured leading to near-exsanguination. This report is to highlight the need for experienced physicians to supervise the procedure and train the younger physician in the safe performance of the procedure.

  1. Automatic feed system for ultrasonic machining

    DOEpatents

    Calkins, Noel C.

    1994-01-01

    Method and apparatus for ultrasonic machining in which feeding of a tool assembly holding a machining tool toward a workpiece is accomplished automatically. In ultrasonic machining, a tool located just above a workpiece and vibrating in a vertical direction imparts vertical movement to particles of abrasive material which then remove material from the workpiece. The tool does not contact the workpiece. Apparatus for moving the tool assembly vertically is provided such that it operates with a relatively small amount of friction. Adjustable counterbalance means is provided which allows the tool to be immobilized in its vertical travel. A downward force, termed overbalance force, is applied to the tool assembly. The overbalance force causes the tool to move toward the workpiece as material is removed from the workpiece.

  2. Comparison of laparoscopic jejunostomy tube to percutaneous endoscopic gastrostomy tube with jejunal extension: long-term durability and nutritional outcomes.

    PubMed

    Haskins, Ivy N; Strong, Andrew T; Baginsky, Mary; Sharma, Gautam; Karafa, Matthew; Ponsky, Jeffrey L; Rodriguez, John H; Kroh, Matthew D

    2018-05-01

    Enteral access through the jejunum is indicated when patients cannot tolerate oral intake or gastric feeding. While multiple approaches for feeding jejunal access exist, few studies have compared the efficacy of these techniques. The purpose of this study was to investigate the long-term durability, re-intervention rates, and nutritional outcomes following percutaneous endoscopic gastrostomy tubes with jejunal extension tubes (PEG-JET) versus laparoscopic jejunostomy tubes (j-tubes). Retrospective chart review was performed on all patients who underwent PEG-JET or laparoscopic jejunostomy tube placement from January 2005 through December 2015 at our institution. Thirty-day and long-term outcomes were compared between the two groups. A total of 105 patients underwent PEG-JET and 307 patients underwent laparoscopic j-tube placement during the defined study period. In terms of 30-day outcomes, patients who underwent PEG-JET placement were significantly more likely to experience a tube dislodgement event (p = 0.005) and undergo a re-intervention (p < 0.001). Patients who had a laparoscopic j-tube placed were significantly more likely to meet their enteral feeding goals (p = 0.002) and less likely to require nutritional supplementation with total parenteral nutrition (TPN) (p < 0.001). With regard to long-term outcomes, patients who underwent PEG-JET placement were significantly more likely to experience tube occlusion (p < 0.001) and require an endoscopic or surgical tube re-intervention (p < 0.001). Patients who underwent laparoscopic j-tube placement were significantly more likely to experience a tube site leak (p = 0.015) but were less likely to require nutritional supplementation with TPN (p = 0.001). Laparoscopic jejunostomy tubes provide more durable long-term enteral access compared to PEG-JET. Consideration should be given to laparoscopic jejunostomy tube placement in eligible patients who cannot tolerate oral intake or gastric

  3. Abrasion Resistance and Mechanical Properties of Waste-Glass-Fiber-Reinforced Roller-compacted Concrete

    NASA Astrophysics Data System (ADS)

    Yildizel, S. A.; Timur, O.; Ozturk, A. U.

    2018-05-01

    The potential use of waste glass fibers in roller-compacted concrete (RCC) was investigated with the aim to improve its performance and reduce environmental effects. The research was focused on the abrasion resistance and compressive and flexural strengths of the reinforced concrete relative to those of reference mixes without fibers. The freeze-thaw resistance of RCC mixes was also examined. It was found that the use of waste glass fibers at a rate of 2 % increased the abrasion resistance of the RCC mixes considerably.

  4. Experimental Evidence that Abrasion of Carbonate Sand is a Significant Source of Carbonate Mud

    NASA Astrophysics Data System (ADS)

    Trower, L.; Kivrak, L.; Lamb, M. P.; Fischer, W. W.

    2017-12-01

    Carbonate mud is a major sedimentary component of modern and ancient tropical carbonate environments, yet its enigmatic origin remains debated. Early views on the origin of carbonate mud considered the abrasion of carbonate sand during sediment transport as a possible mechanism. In recent decades, however, prevailing thought has generally settled on a binary explanation: 1) precipitation of aragonite needles within the water column, and 2) post-mortem dispersal of biological aragonite, in particular from algae, and perhaps aided by fish. To test these different hypotheses, we designed a model and a set of laboratory experiments to quantify the rates of mud production associated with sediment transport. We adapted a recent model of ooid abrasion rate to predict the rate of mud production by abrasion of carbonate sand as a function of grain size and sediment transport mode. This model predicts large mud production rates, ranging from 103 to 104 g CaCO3/m2/yr for typical grain sizes and transport conditions. These rate estimates are at least one order of magnitude more rapid than the 102 g CaCO3/m2/yr estimates for other mechanisms like algal biomineralization, indicating that abrasion could produce much larger mud fluxes per area as other mechanisms. We tested these estimates using wet abrasion mill experiments; these experiments generated mud through mechanical abrasion of both ooid and skeletal carbonate sand for grain sizes ranging from 250 µm to >1000 µm over a range of sediment transport modes. Experiments were run in artificial seawater, including a series of controls demonstrating that no mud was produced via homogenous nucleation and precipitation in the absence of sand. Our experimental rates match the model predictions well, although we observed small systematic differences in rates between abrasion ooid sand and skeletal carbonate sand that likely stems from innate differences in grain angularity. Electron microscopy of the experimental products revealed

  5. NK cells are necessary for recovery of corneal CD11c+ dendritic cells after epithelial abrasion injury

    USDA-ARS?s Scientific Manuscript database

    Mechanisms controlling CD11c(+) MHCII(+) DCs during corneal epithelial wound healing were investigated in a murine model of corneal abrasion. Selective depletion of NKp46(+) CD3- NK cells that normally migrate into the cornea after epithelial abrasion resulted in >85% reduction of the epithelial CD1...

  6. Flow rate of nutrient preparations through nasogastric tubes.

    PubMed Central

    Skidmore, F. D.

    1980-01-01

    Experiments have been carried out in vitro to determine the relationships between the internal diameter of fine-bore nasogastric tubes, the viscosity of nutrient solutions, and the flow rate that can be achieved in the enteral feeding of surgical patients. It was found that such tubes are capable of delivering 3-5 l of nutrient solution in 24 h without a pump. The findings are discussed in relation to the supply of nitrogen and energy to the patient. PMID:6772081

  7. Continuous feedings of fortified human milk lead to nutrient losses of fat, calcium, and phosphorous

    USDA-ARS?s Scientific Manuscript database

    Substantial losses of nutrients may occur during tube (gavage) feeding of fortified human milk. Our objective was to compare the losses of key macronutrients and minerals based on method of fortification, and gavage feeding method. We used clinically available gavage feeding systems and measured pre...

  8. Leucine pulses enhance skeletal muscle protein synthesis during continuous feeding in neonatal pigs

    USDA-ARS?s Scientific Manuscript database

    Infants unable to maintain oral feeding can be nourished by orogastric tube. We have shown that orogastric continuous feeding restricts muscle protein synthesis compared with intermittent bolus feeding in neonatal pigs. To determine whether leucine leu infusion can be used to enhance protein synthes...

  9. Pool boiling of nanofluids on rough and porous coated tubes: experimental and correlation

    NASA Astrophysics Data System (ADS)

    Cieśliński, Janusz T.; Kaczmarczyk, Tomasz Z.

    2014-06-01

    The paper deals with pool boiling of water-Al2O3 and water- Cu nanofluids on rough and porous coated horizontal tubes. Commercially available stainless steel tubes having 10 mm outside diameter and 0.6 mm wall thickness were used to fabricate the test heater. The tube surface was roughed with emery paper 360 or polished with abrasive compound. Aluminium porous coatings of 0.15 mm thick with porosity of about 40% were produced by plasma spraying. The experiments were conducted under different absolute operating pressures, i.e., 200, 100, and 10 kPa. Nanoparticles were tested at the concentration of 0.01, 0.1, and 1% by weight. Ultrasonic vibration was used in order to stabilize the dispersion of the nanoparticles. It was observed that independent of operating pressure and roughness of the stainless steel tubes addition of even small amount of nanoparticles augments heat transfer in comparison to boiling of distilled water. Contrary to rough tubes boiling heat transfer coefficient of tested nanofluids on porous coated tubes was lower compared to that for distilled water while boiling on porous coated tubes. A correlation equation for prediction of the average heat transfer coefficient during boiling of nanofluids on smooth, rough and porous coated tubes is proposed. The correlation includes all tested variables in dimensionless form and is valid for low heat flux, i.e., below 100 kW/m2.

  10. Kaumana lava tube

    NASA Technical Reports Server (NTRS)

    Greeley, R.

    1974-01-01

    The entrance to Kaumana Lava Tube is in a picnic ground next to Highway 20 (Kaumana Drive) about 6.5 km southwest of Hilo. The area is passed on the way to the Kona Coast via the Saddle Road and is identified by a Hawaii Visitors Bureau sign. Although it is not the largest lava tube in the islands, Kaumana Lava Tube is an interesting geological formation, displaying many of the features typical of lava tube interiors. It is accessible, relatively easy to walk through, and is in an excellent state of preservation. The tube developed in a historic lava flow (1881, from Mauna Loa), and many aspects of lava tube activity are observed.

  11. Lunar Lava Tube Sensing

    NASA Technical Reports Server (NTRS)

    York, Cheryl Lynn; Walden, Bryce; Billings, Thomas L.; Reeder, P. Douglas

    1992-01-01

    Large (greater than 300 m diameter) lava tube caverns appear to exist on the Moon and could provide substantial safety and cost benefits for lunar bases. Over 40 m of basalt and regolith constitute the lava tube roof and would protect both construction and operations. Constant temperatures of -20 C reduce thermal stress on structures and machines. Base designs need not incorporate heavy shielding, so lightweight materials can be used and construction can be expedited. Identification and characterization of lava tube caverns can be incorporated into current precursor lunar mission plans. Some searches can even be done from Earth. Specific recommendations for lunar lava tube search and exploration are (1) an Earth-based radar interferometer, (2) an Earth-penetrating radar (EPR) orbiter, (3) kinetic penetrators for lunar lava tube confirmation, (4) a 'Moon Bat' hovering rocket vehicle, and (5) the use of other proposed landers and orbiters to help find lunar lava tubes.

  12. [Head and neck cancer patients included at home enteral nutrition by tube].

    PubMed

    Cots Seignot, I; Cárdenas Lagranja, G; Puiggròs Llop, C; Chicharro Serrano, L; Pérez-Portabella Maristany, C; Planas Vilà, M

    2009-01-01

    To know characteristics and the patients' evolution with head and neck cancer who received radiotherapy treatment and they were included at a home enteral nutrition (HEN) by feeding tube programme. To analyse the weight evolution according to the start of HEN before or after radiotherapy. Observational study of tube feeding patients with head and neck cancer who were included in HEN programme in our hospital for two years. Variables analysed: gender, age, Body Mass Index (BMI), Karnofsky Index (KI), reason for nutritional support, type of feeding tube, formula used and prescribed caloric contribution, necessity to change access device and HEN days. 62 patients were studied (77.4% men; 22.6% women). Age 64 +/- 10.1 years (rang: 39-90). The dysphagia was the main cause to begin enteral nutrition by feeding tube in these patients. Naso-gastric tube was prevalence (67.7%). The most used formula was polymeric hypercaloric diet with a mean of caloric contribution of 1,629 +/- 267.09 kcal/day. Overall, there was a weight loss in all patients during the study period time. However, patients who began the HEN by feeding tube before the radiotherapy treatment, the BMI did not decrease. All patients who began feeding tube before oncological treatment didn't lose weight for the period of study.

  13. Design and evaluation of high-volume fly ash (HVFA) concrete mixes, report D : creep, shrinkage, and abrasion resistance of HVFA concrete.

    DOT National Transportation Integrated Search

    2012-10-01

    The main objective of this study was to determine the effect on shrinkage, creep, : and abrasion resistance of high-volume fly ash (HVFA) concrete. The HVFA concrete : test program consisted of comparing the shrinkage, creep, and abrasion performance...

  14. Conduction cooled tube supports

    DOEpatents

    Worley, Arthur C.; Becht, IV, Charles

    1984-01-01

    In boilers, process tubes are suspended by means of support studs that are in thermal contact with and attached to the metal roof casing of the boiler and the upper bend portions of the process tubes. The support studs are sufficiently short that when the boiler is in use, the support studs are cooled by conduction of heat to the process tubes and the roof casing thereby maintaining the temperature of the stud so that it does not exceed 1400.degree. F.

  15. COAXIAL TUBE COUPLING

    DOEpatents

    Niemoth, H.R.

    1963-02-26

    BS>This patent shows a device for quickly coupling coaxial tubes in metal-to-metal fashion, so as to be suitable for use in a nuclear reactor. A threaded coliar urges a tapered metal extension on the outer coaxial tube into a tapered seat in the device and simultaneously exerts pressure through a coaxial helical spring so that a similar extension on the inner tube seats in a similar seat near the other end. (AEC)

  16. TUBE SPLITTING APPARATUS

    DOEpatents

    Frantz, C.E.; Cawley, W.E.

    1961-05-01

    A tool is described for cutting a coolant tube adapted to contain fuel elements to enable the tube to be removed from a graphite moderator mass. The tool splits the tube longitudinally into halves and curls the longitudinal edges of the halves inwardly so that they occupy less space and can be moved radially inwardly away from the walls of the hole in the graphite for easy removal from the graphite.

  17. Wound tube heat exchanger

    DOEpatents

    Ecker, Amir L.

    1983-01-01

    What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

  18. Composite Pulse Tube

    NASA Technical Reports Server (NTRS)

    Martin, Jerry L.; Cloyd, Jason H.

    2007-01-01

    A modification of the design of the pulse tube in a pulse-tube cryocooler reduces axial thermal conductance while preserving radial thermal conductance. It is desirable to minimize axial thermal conductance in the pulse-tube wall to minimize leakage of heat between the warm and cold ends of the pulse tube. At the same time, it is desirable to maximize radial thermal conductance at the cold end of the pulse tube to ensure adequate thermal contact between (1) a heat exchanger in the form of a stack of copper screens inside the pulse tube at the cold end and (2) the remainder of the cold tip, which is the object to which the heat load is applied and from which heat must be removed. The modified design yields a low-heat-leak pulse tube that can be easily integrated with a cold tip. A typical pulse tube of prior design is either a thin-walled metal tube or a metal tube with a nonmetallic lining. It is desirable that the outer surface of a pulse tube be cylindrical (in contradistinction to tapered) to simplify the design of a regenerator that is also part of the cryocooler. Under some conditions, it is desirable to taper the inner surface of the pulse tube to reduce acoustic streaming. The combination of a cylindrical outer surface and a tapered inner surface can lead to unacceptably large axial conduction if the pulse tube is made entirely of metal. Making the pulse-tube wall of a nonmetallic, lowthermal- conductivity material would not solve the problem because the wall would not afford the needed thermal contact for the stack of screens in the cold end. The modified design calls for fabricating the pulse tube in two parts: a longer, nonmetallic part that is tapered on the inside and cylindrical on the outside and a shorter, metallic part that is cylindrical on both the inside and the outside. The nonmetallic part can be made from G-10 fiberglass-reinforced epoxy or other low-thermal-conductivity, cryogenically compatible material. The metallic part must have high

  19. Fuel nozzle tube retention

    SciTech Connect

    Cihlar, David William; Melton, Patrick Benedict

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  20. Sapphire tube pressure vessel

    DOEpatents

    Outwater, John O.

    2000-01-01

    A pressure vessel is provided for observing corrosive fluids at high temperatures and pressures. A transparent Teflon bag contains the corrosive fluid and provides an inert barrier. The Teflon bag is placed within a sapphire tube, which forms a pressure boundary. The tube is received within a pipe including a viewing window. The combination of the Teflon bag, sapphire tube and pipe provides a strong and inert pressure vessel. In an alternative embodiment, tie rods connect together compression fittings at opposite ends of the sapphire tube.

  1. Apical bud toughness tests and tree sway movements to examine crown abrasion: preliminary results

    Treesearch

    Tyler Brannon; Wayne Clatterbuck

    2012-01-01

    Apical bud toughness differences were examined for several species to determine if crown abrasion affects shoot growth of determinate and indeterminate species during stand development. Determinate buds will set and harden after initial shoot elongation in the spring, while the indeterminate shoots form leaves from the apical meristem continuously based on the...

  2. Study of abrasive wear process of lining of grinding chamber of vortex-acoustic disperser

    NASA Astrophysics Data System (ADS)

    Perelygin, D. N.

    2018-03-01

    The theoretical and experimental studies of the process of gas-abrasive wear of the lining of a vortex-acoustic disperser made it possible to establish the conditions and patterns of their occurrence and also to develop proposals for its reduction.

  3. Abrasive wear behavior of heat-treated ABC-silicon carbide

    SciTech Connect

    Zhang, Xiao Feng; Lee, Gun Y.; Chen, Da

    2002-06-17

    Hot-pressed silicon carbide, containing aluminum, boron, and carbon additives (ABC-SiC), was subjected to three-body and two-body wear testing using diamond abrasives over a range of sizes. In general, the wear resistance of ABC-SiC, with suitable heat treatment, was superior to that of commercial SiC.

  4. Spent coffee grounds as air-propelled abrasive grit for weed control

    USDA-ARS?s Scientific Manuscript database

    Spent coffee grounds (SCG) represent a significant food waste residue. Value-added uses for this material would be beneficial. Gritty agricultural residues, such as corncob grit, can be employed as abrasive air-propelled agents for organically-compatible postemergence shredding of weed seedlings sel...

  5. Propelled abrasive grit applications for weed management in transitional corn grain production systems

    USDA-ARS?s Scientific Manuscript database

    Weed control is challenging to farmers who are transitioning from production systems that use synthetic herbicides to organic systems. A two-year field study examined weed control efficacy and corn grain yield of air-propelled corncob grit abrasion for in-row weed control. Grits were applied based o...

  6. Tribological properties of multifunctional coatings with Shape Memory Effect in abrasive wear

    NASA Astrophysics Data System (ADS)

    Blednova, Zh. M.; Dmitrenko, D. V.; Balaev, E. U. O.

    2018-01-01

    The article gives research results of the abrasive wear process on samples made of Steel 1045, U10 and with applied composite surface layer "Nickel-Multicomponent material with Shape Memory Effect (SME) based on TiNi". For the tests we have chosen TiNiZr, which is in the martensite state and TiNiHfCu, which is in the austenitic state at the test temperature. The formation of the surface layer was carried out by high-speed oxygen-fuel deposition in a protective atmosphere of argon. In the wear test, Al2O3 corundum powder was used as an abrasive. It is shown that the wear rate of samples with a composite surface layer of multicomponent materials with SME is significantly reduced in comparison with the base, which is explained by reversible phase transformations of the surface layer with SME. After carrying out the additional surface plastic deformation (SPD), the resistance of the laminated composition to abrasion wear has greatly enhanced, due to the reinforcing effect of the SPD. It is recommended for products working in conditions of abrasive wear and high temperatures to use the complex formation technology of the surface composition "steel-nickel-material with high-temperature SME", including preparation of the substrate surface and the deposited material, high-speed spraying in the protective atmosphere of argon, followed by SPD.

  7. Neural network approximation of tip-abrasion effects in AFM imaging

    NASA Astrophysics Data System (ADS)

    Bakucz, Peter; Yacoot, Andrew; Dziomba, Thorsten; Koenders, Ludger; Krüger-Sehm, Rolf

    2008-06-01

    The abrasion (wear) of tips used in scanning force microscopy (SFM) directly influences SFM image quality and is therefore of great relevance to quantitative SFM measurements. The increasing implementation of automated SFM measurement schemes has become a strong driving force for increasing efforts towards the prediction of tip wear, as it needs to be ensured that the probe is exchanged before a level of tip wear is reached that adversely affects the measurement quality. In this paper, we describe the identification of tip abrasion in a system of SFM measurements. We attempt to model the tip-abrasion process as a concatenation of a mapping from the measured AFM data to a regression vector and a nonlinear mapping from the regressor space to the output space. The mapping is formed as a basis function expansion. Feedforward neural networks are used to approximate this mapping. The one-hidden layer network gave a good quality of fit for the training and test sets for the tip-abrasion system. We illustrate our method with AFM measurements of both fine periodic structures and randomly oriented sharp features and compare our neural network results with those obtained using other methods.

  8. Air-propelled abrasive grit for postemergence in-row weed control in field corn

    USDA-ARS?s Scientific Manuscript database

    Organic growers need additional tools for weed control. A new technique involving abrasive grit propelled by compressed air was tested in field plots. Grit derived from corn cobs was directed at seedlings of summer annual weeds growing at the bases of corn plants when the corn was at differing early...

  9. Influence of different toothpaste abrasives on the bristle end-rounding quality of toothbrushes.

    PubMed

    de Oliveira, G J P L; de Aveiro, J M; Pavone, C; Marcantonio, R A C

    2015-02-01

    To evaluate the influence of different toothpaste abrasives on the bristle wear and bristle tip morphology of toothbrushes with different degrees of hardness. Ninety samples of bovine incisor teeth were used in this study. The samples were randomly divided into three groups according to the bristle hardness of the toothbrush used: soft bristles (S); extra-soft bristles (ES); hard bristles (H). The toothbrushes of each group were randomly divided into six subgroups with five toothbrushes each, according to the abrasive of the toothpaste used in the simulation: Negative control (distilled water); toothpaste 1 (silica); toothpaste 2 (hydrated silica); toothpaste 3 (calcium carbonate, calcium bicarbonate and silica); toothpaste 4 (tetrapotassium pyrophosphate, silica and titanium dioxide); toothpaste 5 (calcium carbonate). The samples were placed in a toothbrushing simulating machine that simulating three months of brushing. The toothbrush bristles were evaluated by the bristle wear index, and the bristle tips morphology was evaluated by the bristle tip morphology index. The ES brush presented the highest bristle wear among the toothbrushes. Additionally, the S brushes showed better morphology of the bristles followed by ES and H brushes. The type of abrasive only influenced the bristle tip morphology of the ES brushes. The toothpaste 3 induced the worse bristle tip morphology than all the other toothpastes. Different abrasives have influence only on the bristle tip morphology of the ES brushes. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Optical tools for high-throughput screening of abrasion resistance of combinatorial libraries of organic coatings

    NASA Astrophysics Data System (ADS)

    Potyrailo, Radislav A.; Chisholm, Bret J.; Olson, Daniel R.; Brennan, Michael J.; Molaison, Chris A.

    2002-02-01

    Design, validation, and implementation of an optical spectroscopic system for high-throughput analysis of combinatorially developed protective organic coatings are reported. Our approach replaces labor-intensive coating evaluation steps with an automated system that rapidly analyzes 8x6 arrays of coating elements that are deposited on a plastic substrate. Each coating element of the library is 10 mm in diameter and 2 to 5 micrometers thick. Performance of coatings is evaluated with respect to their resistance to wear abrasion because this parameter is one of the primary considerations in end-use applications. Upon testing, the organic coatings undergo changes that are impossible to quantitatively predict using existing knowledge. Coatings are abraded using industry-accepted abrasion test methods at single-or multiple-abrasion conditions, followed by high- throughput analysis of abrasion-induced light scatter. The developed automated system is optimized for the analysis of diffusively scattered light that corresponds to 0 to 30% haze. System precision of 0.1 to 2.5% relative standard deviation provides capability for the reliable ranking of coatings performance. While the system was implemented for high-throughput screening of combinatorially developed organic protective coatings for automotive applications, it can be applied to a variety of other applications where materials ranking can be achieved using optical spectroscopic tools.

  11. ICAM-1 mediates surface contact between neutrophils and keratocytes following corneal epithelial abrasion in the mouse

    USDA-ARS?s Scientific Manuscript database

    Corneal epithelial abrasion elicits an inflammatory response involving neutrophil (PMN) recruitment from the limbal vessels into the corneal stroma. These migrating PMNs make surface contact with collagen and stromal keratocytes. Using mice deficient in PMN integrin CD18, we previously showed that P...

  12. Martian and Terrestrial Rock Abrasion from Wind Tunnel and Field Studies

    NASA Technical Reports Server (NTRS)

    Bridges, N. T.; Greeley, R.; Eddlemon, E.; Laity, J. E.; Meyer, C.; Phoreman, J.; White, B. R.

    2003-01-01

    Earth and Mars exhibit ventifacts, rocks that have been abraded by saltating sand. Previous theoretical and laboratory studies have determined abrasion susceptibilities of rocks as a function of sand type and impact angle and rock material strengths. For the last two years we have been engaged in wind tunnel and field studies to better understand the fundamental factors which control and influence rock abrasion and ventifact formation on Earth and Mars. In particular, we are examining: 1) What types of rocks (composition, texture, and shape) preferentially erode and what are the relative rates of one type vs. another? 2) What are the controlling factors of the aeolian sand cloud (flux, particle speed, surface roughness, etc) which favor rock abrasion?, 3) How do specific ventifact characteristics tie into their mode of formation and rock properties? We find several important factors: 1) Initial rock shape controls the rate of abrasion, with steeper faces abrading faster than shallower ones. The relationship is partly dependent on angle-dependent flux (proportional to sin[theta]) but exhibits additional non-linear effects from momentum transfer efficiency and rebound effects that vary with incidence angle. 2) Irregular targets with pits or grooves abrade at greater rates than targets with smooth surfaces, with indentations generally enlarging with time. Surfaces become rougher with time. 3) Targets also abrade via slope retreat, which is roughly dependent on the slope of the front face. The formation of basal sills is common, as observed on terrestrial and Martian ventifacts.

  13. Erosion of enamel by non-carbonated soft drinks with and without toothbrushing abrasion.

    PubMed

    Hemingway, C A; Parker, D M; Addy, M; Barbour, M E

    2006-10-07

    To investigate how enamel loss due to erosion, and due to cycling of erosion and abrasion, depends on compositional parameters of soft drinks, and particularly whether the thickness of the erosive softened layer is a function of drink composition. University dental hospital research laboratory in the UK, 2004. Six drinks were chosen based on their popularity and composition: apple juice, orange juice, apple drink, orange drink, cranberry drink and 'ToothKind' blackcurrant drink. Group A samples (n = 36) were exposed to soft drinks at 36 degrees C for six consecutive 10 minute periods. Group B samples (n = 36) were subjected to alternating erosion and toothbrushing, repeated six times. Enamel loss was measured using optical profilometry. Group A: significant enamel loss was seen for all drinks (p < 0.001). Erosion was correlated with pH and calcium concentration but not phosphate concentration or titratable acidity. Group B: significant additional material loss due to toothbrush abrasion occurred with all drinks. Abrasive enamel loss differed between the drinks and was positively correlated with drink erosive potential. Enamel loss by erosion is exacerbated by subsequent abrasion. The amount of softened enamel removed by toothbrushing is a function of the chemical composition of the erosive medium.

  14. Scratching technique for the study and analysis of soil surface abrasion mechanism

    NASA Astrophysics Data System (ADS)

    Ta, Wanquan

    2007-11-01

    Aeolian abrasion is the most fundamental and active surface process that takes place in arid and semi-arid environments. Its nature is a wear process for wind blown grains impinging on a soil or sediment surface, which causes particles and aggregates to fracture from the soil surface through a series of plastic and brittle cracking deformation such as cutting, ploughing and brittle fracturing. Using a Universal Micro-Tribometer (UMT), a scratching test was carried out on six soil surfaces (sandy soil, sand loam, silt loam, loam, silt clay loam, and silt clay). The results indicate that traces of normal and tangential force vs. time show a jagged curve, which can reflect the plastic deformation and brittle fracturing of aggregates and particles of various sizes fractured from the soil surfaces. The jagged curve peaks, and the area enclosed underneath, may represent the bonding forces and bonding energies of some aggregates and grains on the soil surface, respectively. Connecting the scratching test with an impact abrasion experiment furthermore demonstrates that soil surface abrasion rates are proportional to the square of speeds of impacting particles and to the 2.6 power of mean soil grain size, and inversely proportional to the 1.5 power of specific surface abrasive energy or to the 1.7 power of specific surface hardness.

  15. Laser abrasion for cosmetic and medical treatment of facial actinic damage

    SciTech Connect

    David, L.M.; Lask, G.P.; Glassberg, E.

    1989-06-01

    Previous studies have shown the carbon dioxide (CO/sub 2/) laser to be effective in the treatment of actinic cheilitis. After CO/sub 2/ laser abrasion, normal skin and marked cosmetic improvement of the lip were noted. In our study, twenty-three patients were treated with CO/sub 2/ laser abrasions for cosmetic improvement of facial lines and actinic changes. Pre- and postoperative histopathologic examinations were made on two patients. Preoperative examination of specimens from actinically damaged skin showed atypical keratinocytes in the basal layer of the epidermis, with overlying dense compact orthokeratosis and parakeratosis. Abundant solar elastosis was seen in the papillary dermis.more » Postoperative histologic specimens showed a normal-appearing epidermis with fibrosis in the papillary dermis and minimal solar elastosis (about four weeks after laser treatment). At present, various modalities are available for the regeneration of the aged skin, including chemical peels and dermabrasion. Significantly fewer complications were noted with CO/sub 2/ laser abrasion than with these methods. Thus, CO/sub 2/ laser abrasion can be useful in the cosmetic and medical treatment of the aged skin. Marked clinical and histologic improvement has been demonstrated.« less

  16. Interfacing superhydrophobic silica nanoparticle films with graphene and thermoplastic polyurethane for wear/abrasion resistance.

    PubMed

    Naderizadeh, Sara; Athanassiou, Athanassia; Bayer, Ilker S

    2018-06-01

    Nanoparticle films are one of the most suitable platforms for obtaining sub-micrometer and nanometer dual-scale surface texture required for liquid repellency. The assembly of superhydrophobic nanoparticles into conformal and strongly adherent films having abrasion-induced wear resistance still poses a significant challenge. Various techniques have been developed over the years to render nanoparticle films with good liquid repellent properties and transparency. However, forming abrasion resistant superhydrophobic nanoparticle films on hard surfaces is challenging. One possibility is to partially embed or weld nanoparticles in thin thermoplastic primers applied over metals. Hexamethyldisilazane-functionalized fumed silica nanoparticle films spray deposited on aluminum surfaces were rendered abrasion resistant by thermally welding them into thermoplastic polyurethane (TPU) primer applied a priori over aluminum. Different solvents, nanoparticle concentrations and annealing temperatures were studied to optimize nanoparticle film morphology and hydrophobicity. Thermal annealing at 150 °C enhanced stability and wear resistance of nanoparticle films. A thin thermal interface layer of graphene nanoplatelets (GnPs) between the primer and the nanoparticle film significantly improved superhydrophobic wear resistance after annealing. As such, superhydrophobic nanocomposite films with the GnPs thermal interface layer displayed superior abrasion-induced wear resistance under 20 kPa compared to films having no GnPs-based thermal interface. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Tribological properties of amorphous alloys and the role of surfaces in abrasive wear of materials

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1982-01-01

    The research approach undertaken by the authors relative to the subject, and examples of results from the authors are reviewed. The studies include programs in adhesion, friction, and various wear mechanisms (adhesive and abrasive wear). The materials which have been studied include such ceramic and metallic materials as silicon carbide, ferrites, diamond, and amorphous alloys.

  18. NK cells modulate the inflammatory response to corneal epithelial abrasion and thereby support wound healing

    USDA-ARS?s Scientific Manuscript database

    Natural killer cells are lymphocytes of the innate immune system that have crucial cytotoxic and regulatory roles in adaptive immunity and inflammation. Herein, we consider a role for these cells in corneal wound healing. After a 2-mm central epithelial abrasion of the mouse cornea, a subset of clas...

  19. Air-Abrasive Disinfection of Implant Surfaces in a Simulated Model of Periimplantitis.

    PubMed

    Quintero, David George; Taylor, Robert Bonnie; Miller, Matthew Braden; Merchant, Keith Roshanali; Pasieta, Scott Anthony

    2017-06-01

    This in vitro study aimed to evaluate the ability of air-powder abrasion to decontaminate dental implants. Twenty-six implants were inoculated with a Streptococcus sanguinis biofilm media in a novel periimplantitis defect model. Six implants served as controls, and 20 implants were disinfected with either the Cavitron JET Plus or the AIR-FLOW PERIO air-powder abrasion units. Residual bacteria were cultured, and colony forming units (CFUs) were totaled at 24 hours. As expected, negative control implant cultures showed no evidence of viable bacteria. Bacterial growth was observed on all positive control cultures, whereas only 15% of the experimental cultures displayed evidence of viable bacteria. The average CFU per streak for the positive control was 104 compared with a maximum of 10 and 4 CFUs for the Cavitron JET Plus and AIR-FLOW PERIO, respectively. There was a 99.9% reduction in bacteria for both air-powder abrasion instruments. Air-powder abrasion is an effective technique for the decontamination of dental implants, and the Cavitron JET Plus and AIR-FLOW PERIO are equally successful at eliminating viable bacteria from implant surfaces.

  20. Platelet recruitment promotes keratocyte repopulation following corneal epithelial abrasion in the mouse

    USDA-ARS?s Scientific Manuscript database

    Corneal abrasion not only damages the epithelium but also induces stromal keratocyte death at the site of injury. While a coordinated cascade of inflammatory cell recruitment facilitates epithelial restoration, it is unclear if this cascade is necessary for keratocyte recovery. Since platelet and ne...

  1. IBPAT/OSHA Health and Safety Education Quiz Book. Painters, Abrasive Blasters, Tapers, Paint Makers, Floorcoverers.

    ERIC Educational Resources Information Center

    International Brotherhood of Painters and Allied Trades, Washington, DC.

    Designed for use by instructors using the "Health and Safety Education Book" (International Brotherhood of Painters and Allied Trades/Occupational Safety and Health Act), this book contains quizzes specifically for painters, abrasive blasters, tapers, paint makers, and floorcoverers. Quizzes included in the book focus on testing areas such as (1)…

  2. The efficacy of a highly concentrated fluoride dentifrice on bovine enamel subjected to erosion and abrasion.

    PubMed

    Rios, Daniela; Magalhães, Ana Carolina; Polo, Renata Ocon Braga; Wiegand, Annette; Attin, Thomas; Buzalaf, Marilia Afonso Rabelo

    2008-12-01

    Researchers have proposed the use of fluoride for the prevention of enamel wear; however, only limited information is available about the impact of fluoridated dentifrices. Because tooth wear is a well-recognized dental problem, the authors conducted an in situ, ex vivo study to assess the efficacy of a highly concentrated fluoride dentifrice on bovine enamel subjected to erosion and abrasion. The authors conducted a double-blind, crossover in situ study consisting of three phases (seven days each). In each phase, the authors tested one of the dentifrices (5,000 parts per million fluoride [F]; 1,100 ppm F; no F). They performed erosive challenges with the use of cola drink (60 seconds, four times per day) and abrasive challenges via toothbrushing (30 seconds, four times per day). The authors determined the enamel loss via profilometry. The authors tested the data by using two-way analysis of variance (P < .05). For the erosion-plus-abrasion condition, the study results showed that enamel wear was significantly higher than that with erosion alone. The findings showed no significant differences between the dentifrices regarding enamel wear. Within the in situ, ex vivo conditions of this study, the authors concluded that the highly concentrated fluoride dentifrice did not have a protective effect on enamel against erosion and erosion plus toothbrushing abrasion. Patients at risk of developing enamel erosion should benefit from preventive measures other than fluoride dentifrice, because even a highly concentrated fluoride dentifrice does not appear to prevent enamel erosion.

  3. Rates of Eolian Rock Abrasion in the Ice-Free Valleys, Antarctica

    NASA Astrophysics Data System (ADS)

    Hallet, B.; Malin, M. C.; Sletten, R. S.

    2016-12-01

    Eolian abrasion is a principal surface process in dry regions of Earth and Mars and there is evidence for wind processes active on Venus and Titan. Rock abrasion also has practical significance in diverse fields ranging from preservation of cultural material (artifacts, monuments) to damage of solar panels and windshields in arid regions. Despite its scientific and practical importance, and there have ben only few studies that define rates of rock abrasion quantitatively under natural conditions. Herein we report abrasion rates that have been exceptionally well characterized through a unique long-term (30+-year) field experiment in the ice-free McMurdo Dry Valleys, Antarctica. In 1983 and 1984, over 5000 rock targets of several lithologies (25.4 mm-diameter and 5 mm-thick disks of dolerite, basalt, tuff and sandstone) were installed at five heights (7,14, 21, 35, and 70 cm) facing the 4 cardinal directions at 10 locations (one additional site contains fewer targets). Sequential collections of rock targets exposed to abrasion enable definition of mass loss after 1, 5, 10, 30 and 31 years of exposure; the latter were retrieved during the 2014-2015 season. The abrasion rates generally show striking consistency for each lithology at any site; the multiple targets permit definition of intrinsic differences in mass loss. The rates vary considerably from site to site owing to differences in availability of transportable sediment, wind regime, and surface roughness, and at each site, owing to target orientation relative to the dominant winds and, secondarily, to height above the ground. For the hardest targets, basalt and dolerite, mass loss in 30+ years ranged from essentially zero at some sites to 1/3 of the deployed mass (2.59 g; equivalent to a rock thickness >1.8 mm) where abrasion was most active (Site 7, Central Wright Valley). The tuff targets showed the greatest mass loss, and in many cases were entirely abraded away by the end of the experiment.Current work is

  4. Effect of etching and airborne particle abrasion on the microstructure of different dental ceramics.

    PubMed

    Borges, Gilberto Antonio; Sophr, Ana Maria; de Goes, Mario Fernando; Sobrinho, Lourenço Correr; Chan, Daniel C N

    2003-05-01

    The ceramic composition and microstructure surface of all-ceramic restorations are important components of an effective bonding substrate. Both hydrofluoric acid etching and airborne aluminum oxide particle abrasion produce irregular surfaces necessary for micromechanical bonding. Although surface treatments of feldspathic and leucite porcelains have been studied previously, the high alumina-containing and lithium disilicate ceramics have not been fully investigated. The purpose of this study was to assess the surface topography of 6 different ceramics after treatment with either hydrofluoric acid etching or airborne aluminum oxide particle abrasion. Five copings each of IPS Empress, IPS Empress 2 (0.8 mm thick), Cergogold (0.7 mm thick), In-Ceram Alumina, In-Ceram Zirconia, and Procera (0.8 mm thick) were fabricated following the manufacturer's instructions. Each coping was longitudinally sectioned into 4 equal parts by a diamond disk. The resulting sections were then randomly divided into 3 groups depending on subsequent surface treatments: Group 1, specimens without additional surface treatments, as received from the laboratory (control); Group 2, specimens treated by use of airborne particle abrasion with 50-microm aluminum oxide; and Group 3, specimens treated with 10% hydrofluoric acid etching (20 seconds for IPS Empress 2; 60 seconds for IPS Empress and Cergogold; and 2 minutes for In-Ceram Alumina, In-Ceram Zirconia, and Procera). Airborne particle abrasion changed the morphologic surface of IPS Empress, IPS Empress 2, and Cergogold ceramics. The surface topography of these ceramics exhibited shallow irregularities not evident in the control group. For Procera, the 50-microm aluminum oxide airborne particle abrasion produced a flattened surface. Airborne particle abrasion of In-Ceram Alumina and In-Ceram Zirconia did not change the morphologic characteristics and the same shallows pits found in the control group remained. For IPS Empress 2, 10% hydrofluoric

  5. The Effect of Pleural Abrasion on the Treatment of Primary Spontaneous Pneumothorax: A Systematic Review of Randomized Controlled Trials

    PubMed Central

    Ming, Mo-yu; Cai, Shuang-qi; Chen, Yi-Qiang

    2015-01-01

    Background Pleural abrasion has been widely used to control the recurrence of primary spontaneous pneumothorax (PSP). However, controversy still exists regarding the advantages and disadvantages of pleural abrasion compared with other interventions in preventing the recurrence of PSP. Methods The PubMed, Embase, and Cochrane Central Register of Controlled Trials databases were searched up to December 15, 2014 to identify randomized controlled trials (RCTs) that compared the effects of pleural abrasion with those of other interventions in the treatment of PSP. The study outcomes included the PSP recurrence rate and the occurrence rate of adverse effects. Results Mechanical pleural abrasion and apical pleurectomy after thoracoscopic stapled bullectomy exhibited similarly persistent postoperative air leak occurrence rates (p = 0.978) and 1-year PSP recurrence rates (p = 0.821), whereas pleural abrasion led to reduced residual chest pain and discomfort (p = 0.001) and a smaller rate of hemothorax (p = 0.036) than did apical pleurectomy. However, the addition of minocycline pleurodesis to pleural abrasion did not reduce the pneumothorax recurrence rate compared with apical pleurectomy (3.8% for both procedures) but was associated with fewer complications. There was no statistical difference in the pneumothorax recurrence rate between mechanical pleural abrasion and chemical pleurodesis with minocycline on either an intention-to-treat basis (4 of 42 versus 0 of 42, p = 0.12; Fisher exact test) or after exclusions (2 of 40 versus 0 of 42, p = 0.24; Fisher exact test). Pleural abrasion plus minocycline pleurodesis also did not reduce the pneumothorax recurrence rate compared with pleural abrasion alone (p = 0.055). Moreover, pleural abrasion plus minocycline pleurodesis was associated with more intense acute chest pain. The postoperative overall recurrence rate in patients who underwent staple line coverage with absorbable cellulose mesh and fibrin glue was similar to that

  6. Aeolian Rat Tails (ARTs): A New Morphological Indicator of Abrasion Direction

    NASA Astrophysics Data System (ADS)

    Favaro, E. A.; Hugenholtz, C.; Barchyn, T.

    2016-12-01

    Aeolian rat tails (ARTs) are a previously undocumented aeolian abrasion feature observed on ignimbrite surfaces in the Puna Plateau of Northwest Argentina and bare morphological similarity to small-scale features on Mars. We describe the terrestrial features and present an evolutionary sequence from inception to demise. ARTs are regionally-ubiquitous and characterized by a windward abrasion-resistant lithic clast and a downwind-tapering tail. The size of ARTs is controlled by the diameter of the windward lithic clast, observed on the sub-decimeter to meter scale. Their distribution throughout the Campo de Piedra Pómez, and adjacent regions is determined by the ignimbrite clast content. ARTs develop under a uni-modal abrasion direction when lithic clasts are eroded out of the ignimbrite matrix, protrude from the surface, and shelter material directly behind the clast. As the surrounding material is eroded away, a downwind-tapered tail develops. Continued erosion of the adjacent surface leads to the undercutting of clasts, liberating them from the feature where, if small enough, the clasts can be transported downwind, leading to the destruction of the tail and ultimately the feature. This evolutionary sequence accounts not only for the morphology of the feature, but also the presence of loose clasts on the ignimbrite surface, which plays a role in the development of other enigmatic landforms in the area, such as periodic bedrock ridges, yardangs, and megaripples. The significance of the identification of ARTs is due to the necessity of uni-modal abrasion direction for their development, thereby making their orientation a diagnostic indicator of long-term aeolian abrasion direction. ARTs are likely analogs of features identified by MSL Curiosity Rover on Mars, possibly providing information on past and present wind regimes.

  7. The importance of measuring toothpaste abrasivity in both a quantitative and qualitative way

    PubMed Central

    Tellefsen, Georg; Johannsen, Annsofi; Liljeborg, Anders

    2013-01-01

    Objective. To evaluate the relative abrasivity of different toothpastes and polishing pastes both qualitatively and quantitatively. Materials and methods. Acrylic plates were exposed to brushing in a brushing machine with a toothpaste/water slurry for 1 and 6 h. Twelve different toothpastes were used and also four different polishing pastes. The results were evaluated using a profilometer after 1 and 6 h of brushing (corresponding to 2000 and 12 000 double strokes, respectively). A surface roughness value (Ra-value) and also a volume loss value were calculated from the profilometer measurements. These values were then correlated to each other. An unpaired t-test for the difference in the abrasion values between the toothpastes and the abrasion values over time was used. Results. The polishing paste RDA® 170 yielded higher Ra-values than RDA 250®, both after 1 and 6 h of brushing (1.01 ± 0.22 and 8.99 ± 1.55 compared to 0.63 ± 0.26 and 7.83 ± 5.89, respectively) as well as volume loss values (3.71 ± 0.17 and 20.20 ± 2.41 compared to 2.15 ± 1.41 and 14.79 ± 11.76, respectively), thus poor correlations between the RDA and Ra and Volume loss values were shown. Among the toothpastes, Apotekets® showed the highest Ra value after 1 h of brushing and Pepsodent® whitening after 6 h of brushing. Pepsodent® whitening also showed the highest volume loss values, both after 1 and 6 h of brushing. Conclusion. This study emphasizes the importance of not only considering the RDA value, but also a roughness value, when describing the abrasivity of a toothpaste. Furthermore, it can be concluded that so called ‘whitening' toothpastes do not necessarily have a higher abrasive effect than other toothpastes. PMID:22746180

  8. Abrasion resistance of direct and indirect resins as a function of a sealant veneer.

    PubMed

    Ferraz Caneppele, Taciana Marco; Rocha, Daniel Maranha; Màximo Araujo, Maria Amelia; Valera, Màrcia Carneiro; Salazar Marocho, Susana MarIa

    2014-01-01

    Abrasive wear is one of the most common type of wear that not only affect teeth, as also dental restorations. Thus to investigate one of the etiological factors as tooth brushing procedure is clinical relevant in order to select the best material combination that may prevent damage of resin dental restoration's abrasion. This study evaluated the influence of tooth brushing on mass loss and surface roughness of direct Venus (Vs) and indirect Signum (Sg) resin composites, with and without a surface sealant, Fortify (F). Twenty-four specimens were prepared with each resin composite, using their proprietary curing units, according to manufacturer's instructions. All the specimens were polished and ultrasonically cleaned in distilled water for 5 minutes. Half of the specimens of each resin (n = 12) were covered with F (Vs F and Sg F ), except for the control (C) specimens (Vs C and Sg C ), which were not sealed. Mass loss (ML) as well as surface roughness (Ra ) was measured for all the specimens. Then, the specimens were subjected to toothbrush-dentifrice abrasion, using a testing machine for 67.000 brushing strokes, in an abrasive slurry. After brushing simulation, the specimens were removed from the holder, rinsed thoroughly and blot dried with soft absorbent paper. The abrasion of the material was quantitatively determined with final measurements of ML and surface roughness, using the method described above. ML data were analyzed by two-way analysis of variance (ANOVA) and the analysis indicated that resin composites were not statistically different; however, the specimens sealed with F showed higher ML. Ra mean values of the groups Vs F and Sg F significantly increased. Tooth brushing affects mainly the roughness of the direct and indirect resin composites veneered with a sealant.

  9. Gingival abrasion and recession in manual and oscillating-rotating power brush users.

    PubMed

    Rosema, N A M; Adam, R; Grender, J M; Van der Sluijs, E; Supranoto, S C; Van der Weijden, G A

    2014-11-01

    To assess gingival recession (GR) in manual and power toothbrush users and evaluate the relationship between GR and gingival abrasion scores (GA). This was an observational (cross-sectional), single-centre, examiner-blind study involving a single-brushing exercise, with 181 young adult participants: 90 manual brush users and 91 oscillating-rotating power brush users. Participants were assessed for GR and GA as primary response variables. Secondary response variables were the level of gingival inflammation, plaque score reduction and brushing duration. Pearson correlation was used to describe the relationship between number of recession sites and number of abrasions. Prebrushing (baseline) and post-brushing GA and plaque scores were assessed and differences analysed using paired tests. Two-sample t-test was used to analyse group differences; ancova was used for analyses of post-brushing changes with baseline as covariate. Overall, 97.8% of the study population had at least one site of ≥1 mm of gingival recession. For the manual group, this percentage was 98.9%, and for the power group, this percentage was 96.7% (P = 0.621). Post-brushing, the power group showed a significantly smaller GA increase than the manual group (P = 0.004); however, there was no significant correlation between number of recession sites and number of abrasions for either group (P ≥ 0.327). Little gingival recession was observed in either toothbrush user group; the observed GR levels were comparable. Lower post-brushing gingival abrasion levels were seen in the power group. There was no correlation between gingival abrasion as a result of brushing and the observed gingival recession following use of either toothbrush. © 2014 The Authors International Journal of Dental Hygiene Published by John Wiley & Sons Ltd.

  10. Gingival abrasion and recession in manual and oscillating–rotating power brush users

    PubMed Central

    Rosema, NAM; Adam, R; Grender, JM; Van der Sluijs, E; Supranoto, SC; Van der Weijden, GA

    2014-01-01

    Objective To assess gingival recession (GR) in manual and power toothbrush users and evaluate the relationship between GR and gingival abrasion scores (GA). Methods This was an observational (cross-sectional), single-centre, examiner-blind study involving a single-brushing exercise, with 181 young adult participants: 90 manual brush users and 91 oscillating–rotating power brush users. Participants were assessed for GR and GA as primary response variables. Secondary response variables were the level of gingival inflammation, plaque score reduction and brushing duration. Pearson correlation was used to describe the relationship between number of recession sites and number of abrasions. Prebrushing (baseline) and post-brushing GA and plaque scores were assessed and differences analysed using paired tests. Two-sample t-test was used to analyse group differences; ancova was used for analyses of post-brushing changes with baseline as covariate. Results Overall, 97.8% of the study population had at least one site of ≥1 mm of gingival recession. For the manual group, this percentage was 98.9%, and for the power group, this percentage was 96.7% (P = 0.621). Post-brushing, the power group showed a significantly smaller GA increase than the manual group (P = 0.004); however, there was no significant correlation between number of recession sites and number of abrasions for either group (P ≥ 0.327). Conclusions Little gingival recession was observed in either toothbrush user group; the observed GR levels were comparable. Lower post-brushing gingival abrasion levels were seen in the power group. There was no correlation between gingival abrasion as a result of brushing and the observed gingival recession following use of either toothbrush. PMID:24871587

  11. The importance of measuring toothpaste abrasivity in both a quantitative and qualitative way.

    PubMed

    Johannsen, Gunnar; Tellefsen, Georg; Johannsen, Annsofi; Liljeborg, Anders

    2013-01-01

    To evaluate the relative abrasivity of different toothpastes and polishing pastes both qualitatively and quantitatively. Acrylic plates were exposed to brushing in a brushing machine with a toothpaste/water slurry for 1 and 6 h. Twelve different toothpastes were used and also four different polishing pastes. The results were evaluated using a profilometer after 1 and 6 h of brushing (corresponding to 2000 and 12 000 double strokes, respectively). A surface roughness value (Ra-value) and also a volume loss value were calculated from the profilometer measurements. These values were then correlated to each other. An unpaired t-test for the difference in the abrasion values between the toothpastes and the abrasion values over time was used. The polishing paste RDA® 170 yielded higher Ra-values than RDA 250®, both after 1 and 6 h of brushing (1.01 ± 0.22 and 8.99 ± 1.55 compared to 0.63 ± 0.26 and 7.83 ± 5.89, respectively) as well as volume loss values (3.71 ± 0.17 and 20.20 ± 2.41 compared to 2.15 ± 1.41 and 14.79 ± 11.76, respectively), thus poor correlations between the RDA and Ra and Volume loss values were shown. Among the toothpastes, Apotekets® showed the highest Ra value after 1 h of brushing and Pepsodent® whitening after 6 h of brushing. Pepsodent® whitening also showed the highest volume loss values, both after 1 and 6 h of brushing. This study emphasizes the importance of not only considering the RDA value, but also a roughness value, when describing the abrasivity of a toothpaste. Furthermore, it can be concluded that so called 'whitening' toothpastes do not necessarily have a higher abrasive effect than other toothpastes.

  12. Feeding outcomes in infants after supraglottoplasty.

    PubMed

    Eustaquio, Marcia; Lee, Erika Nevin; Digoy, G Paul

    2011-11-01

    Review the impact of bilateral supraglottoplasty on feeding and compare the risk of postoperative feeding difficulties between infants with and without additional comorbidities. Case series with chart review. Children's hospital. The medical records of all patients between birth and 12 months of age treated for laryngomalacia with bilateral supraglottoplasty by a single surgeon (GPD) between December 2005 and September 2009 and followed for a minimum of 1 month were reviewed. Infants with significant comorbidities were evaluated separately. Nutritional intake before and after surgery, as well as speech and language pathology reports, was reviewed to qualify any feeding difficulties. Age at the time of surgery, additional surgical interventions, medical comorbidities, and length of follow-up were also noted during chart review. Of 81 infants who underwent bilateral supraglottoplasty, 75 were eligible for this review. In the cohort of infants without comorbidities, 46 of 48 (96%) had no change or an improvement in their oral intake after surgery. Of the 2 patients with initial worsening of feeding, all resumed oral intake within 2 months. In the group of patients with additional medical comorbidities, 22% required further interventions such as nasogastric tube, dietary modification, or gastrostomy tube placement. Supraglottoplasty in infants has a low incidence of persistent postoperative dysphagia. Infants with additional comorbidities are at a higher risk of feeding difficulty than otherwise healthy infants.

  13. Method for shaping polyethylene tubing

    NASA Technical Reports Server (NTRS)

    Kramer, R. C.

    1981-01-01

    Method forms polyethylene plastic tubing into configurations previously only possible with metal tubing. By using polyethylene in place of copper or stain less steel tubing inlow pressure systems, fabrication costs are significantly reduced. Polyethylene tubing can be used whenever low pressure tubing is needed in oil operations, aircraft and space applications, powerplants, and testing laboratories.

  14. Hologram recording tubes

    NASA Technical Reports Server (NTRS)

    Rajchman, J. H.

    1973-01-01

    Optical memories allow extremely large numbers of bits to be stored and recalled in a matter of microseconds. Two recording tubes, similar to conventional image-converting tubes, but having a soft-glass surface on which hologram is recorded, do not degrade under repeated hologram read/write cycles.

  15. Pyrotechnic Tubing Connector

    NASA Technical Reports Server (NTRS)

    Graves, Thomas J.; Yang, Robert A.

    1988-01-01

    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.

  16. Fallopian Tube Catheterization

    PubMed Central

    Thurmond, Amy Suzanne

    2013-01-01

    Fallopian tube catheterization is used for treatment of infertility caused by proximal tubal occlusion, and has replaced surgical treatment for this condition. More recently, fallopian tube catheterization has been used for tubal sterilization. Interventional radiologists tested numerous methods for tubal occlusion using the rabbit as an animal model. As a result, a tubal device has recently been Food and Drug Administration approved for permanent sterilization using hysteroscopic guidance; it can also be placed fluoroscopically by fallopian tube catheterization as an “off-label” procedure. This is a 5-year continuation and update on a procedure that has been done by interventional radiologists for 25 years; history of the development of fallopian tube catheterization in women has been published in detail in this journal. Highlighted in this article will be description of the basic components needed for fallopian tube catheterization. PMID:24436565

  17. Development of feedback-speed-control system of fixed-abrasive tool for mat-surface fabrication

    NASA Astrophysics Data System (ADS)

    Yanagihara, K.; Kita, R.

    2018-01-01

    This study deals with the new method to fabricate a mat-surface by using fixed-abrasive tool. Mat-surface is a surface with microscopic irregularities whose dimensions are close to the wavelengths of visible light (400-700 nanometers). In order to develop the new method to fabricate mat-surface without pre-masking and large scale back up facility, utilization of fixed-abrasive tool is discussed. The discussion clarifies that abrasives in shot blasting are given kinetic energy along to only plunge-direction while excluding traverse-direction. If the relative motion between tool and work in fixed-abrasive process can be realized as that in blasting, mat-surface will be accomplished with fixed-abrasive process. To realize the proposed idea, new surface-fabrication system to which is adopted feedback-speed-control of abrasive wheel has been designed. The system consists of micro-computer unit (MPU), work-speed sensor, fixed-abrasive wheel, and wheel driving unit. The system can control relative speed between work and wheel in optimum range to produce mat-surface. Finally experiment to verify the developed system is carried out. The results of experiments show that the developed system is effective and it can produce the surface from grinding to mat-surface seamlessly.

  18. Validation of Proposed Metrics for Two-Body Abrasion Scratch Test Analysis Standards

    NASA Technical Reports Server (NTRS)

    Street, Kenneth W., Jr.; Kobrick, Ryan L.; Klaus, David M.

    2013-01-01

    Abrasion of mechanical components and fabrics by soil on Earth is typically minimized by the effects of atmosphere and water. Potentially abrasive particles lose sharp and pointed geometrical features through erosion. In environments where such erosion does not exist, such as the vacuum of the Moon, particles retain sharp geometries associated with fracturing of their parent particles by micrometeorite impacts. The relationship between hardness of the abrasive and that of the material being abraded is well understood, such that the abrasive ability of a material can be estimated as a function of the ratio of the hardness of the two interacting materials. Knowing the abrasive nature of an environment (abrasive)/construction material is crucial to designing durable equipment for use in such surroundings. The objective of this work was to evaluate a set of standardized metrics proposed for characterizing a surface that has been scratched from a two-body abrasion test. This is achieved by defining a new abrasion region termed Zone of Interaction (ZOI). The ZOI describes the full surface profile of all peaks and valleys, rather than just measuring a scratch width. The ZOI has been found to be at least twice the size of a standard width measurement; in some cases, considerably greater, indicating that at least half of the disturbed surface area would be neglected without this insight. The ZOI is used to calculate a more robust data set of volume measurements that can be used to computationally reconstruct a resultant profile for de tailed analysis. Documenting additional changes to various surface roughness par ameters also allows key material attributes of importance to ultimate design applications to be quantified, such as depth of penetration and final abraded surface roughness. Further - more, by investigating the use of custom scratch tips for specific needs, the usefulness of having an abrasion metric that can measure the displaced volume in this standardized

  19. Particle shedding from peristaltic pump tubing in biopharmaceutical drug product manufacturing.

    PubMed

    Saller, Verena; Matilainen, Julia; Grauschopf, Ulla; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

    2015-04-01

    In a typical manufacturing setup for biopharmaceutical drug products, the fill and dosing pump is placed after the final sterile filtration unit in order to ensure adequate dispensing accuracy and avoid backpressure peaks. Given the sensitivity of protein molecules, peristaltic pumps are often preferred over piston pumps. However, particles may be shed from the silicone tubing employed. In this study, particle shedding and a potential turbidity increase during peristaltic pumping of water and buffer were investigated using three types of commercially available silicone tubing. In the recirculates, mainly particles of around 200 nm next to a very small fraction of particles in the lower micrometer range were found. Using 3D laser scanning microscopy, surface roughness of the inner tubing surface was found to be a determining factor for particle shedding from silicone tubing. As the propensity toward particle shedding varied between tubing types and also cannot be concluded from manufacturer's specifications, individual testing with the presented methods is recommended during tubing qualification. Choosing low abrasive tubing can help to further minimize the very low particle counts to be expected in pharmaceutical drug products. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  20. Enteral feeding: drug/nutrient interaction.

    PubMed

    Lourenço, R

    2001-04-01

    Enteral nutrition support via a feeding tube is the first choice for artificial nutrition. Most patients also require simultaneous drug therapy, with the potential risk for drug-nutrient interactions which may become relevant in clinical practice. During enteral nutrition, drug-nutrient interactions are more likely to occur than in patients fed orally. However, there is a lack of awareness about its clinical significance, which should be recognised and prevented in order to optimise nutritional and pharmacological therapeutic goals of safety and efficacy. To raise the awareness of potential drug-nutrient interactions and influence on clinical outcomes. To identify factors that can promote drug-nutrient interactions and contribute to nutrition and/or therapeutic failure. To be aware of different types of drug-nutrient interactions. To understand complex underlying mechanisms responsible for drug-nutrient interactions. To learn basic rules for the administration of medications during tube-feeding. Copyright 2001 Harcourt Publishers Ltd.

  1. Assessment of thermal spray coatings for wear and abrasion resistance applications

    NASA Astrophysics Data System (ADS)

    Karode, Ishaan Nitin

    Thermal spray cermet and metallic coatings are extensively used for wear, abrasion and corrosion control in a variety of industries. The first part of the thesis focuses mainly on testing of sand erosion resistance of thermal spray coatings on carbon composites used in the manufacture of helicopter rotor blades. The test set-up employed is a sand blasting machine and is an effort to duplicate the in-flight conditions especially those encountered in hot arid conditions. The technique adopted follows the Department of Defence test method standard. Carbon Composites have excellent stiffness, strength and low weight/density. The strength to weight ratio is high. Hence, these are used in aerospace applications to a large extent. However, the biggest problem encountered with carbon composites is its low abrasion resistance as its surface is very weak. Hence, thermal spray coatings are used to improve the surface properties of CFRP. Zinc bond coats and WC-Co coatings were tested. However, high amount of thermal stresses were developed between the substrate and the coating due to large differences in the CTE's of the both, leading to high mass losses within two minutes and just 130 grams of sand sprayed on to the coatings with the sand blasting machine built; and hence the coatings with CC as a substrate could not qualify for the application. The second part of the thesis focuses on the assessment of different thermal spray coatings used for manufacture of mechanical seals in pumps and analyze the best coating material for the wear resistance application through detail quantification of material loss by block-on-ring test set-up. A machine based on Block-on-ring test set-up following ASTM G77 (Measurement of Adhesive wear resistance of thermal spray coatings) standards was built to duplicate the pump conditions. Thermally sprayed coated materials were tested in different conditions (Load, time, abrasive). WC-Co had the highest wear resistance (lower volume losses) and

  2. EPA OIG's RSS Feed

    EPA Pesticide Factsheets

    EPA OIG's RSS Feed - The EPA OIG offers an XML news feed (RSS) covering all of our publications and news. To use our pre-made feed, click on the link below, copy the URL, then paste it into your prefferred feed reader.

  3. Micro-abrasion-corrosion behaviour of a biomedical Ti-25Nb-3Mo-3Zr-2Sn alloy in simulated physiological fluid.

    PubMed

    Wang, Zhenguo; Li, Yan; Huang, Weijiu; Chen, Xiaoli; He, Haoran

    2016-10-01

    The micro-abrasion-corrosion behaviour of the biomedical Ti-25Nb-3Mo-3Zr-2Sn alloy in Hank׳s solution with protein has been investigated using electrochemical measurements, tribological tests and scanning electron microscope (SEM) observations. The potentiodynamic polarization tests showed that the corrosion potential (Ecorr) exhibits the maximum value at the abrasive concentration of 0.05gcm(-3) despite of the load level. The tribological results indicated that the total material loss of the Ti-25Nb-3Mo-3Zr-2Sn alloy during micro-abrasion increased with the increasing abrasive concentration at a certain applied load. When the abrasive concentration is no more than 0.15gcm(-3), the total material loss increases with increasing load, while the total material loss exhibits the maximum value at a moderate load in case of higher abrasive concentration levels. This was ascribed to the three-body or two-body micro-abrasion-corrosion at different abrasive concentration levels. The wastage map, abrasion mode map and synergy map associated with the applied load and the abrasive concentration were constructed to evaluate the micro-abrasion-corrosion behaviour of the Ti-25Nb-3Mo-3Zr-2Sn alloy in potential biomedical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Miniature Pulse Tube Cooler

    NASA Astrophysics Data System (ADS)

    Tward, E.; Nguyen, T.; Godden, J.; Toma, G.

    2004-06-01

    A high capacity miniature pulse tube cooler for space that is scaled from the High Efficiency Cryocooler (HEC) is being developed. The low mass (1.5 kg) integral pulse tube cryocooler can provide large cooling power over a wide temperature range (e.g., 5 W at 95 K). The cooler is designed to be compatible with the existing HEC flight electronics. A small back-to-back flexure compressor drives a pulse tube cold head which is integrated with the compressor. The cooler has been tested with both linear and coaxial cold heads. A description of the cooler and its performance in both linear and coaxial cold head versions is presented.

  5. Eustachian Tube Function.

    PubMed

    Ars, Bernard; Dirckx, Joris

    2016-10-01

    The fibrocartilaginous eustachian tube is part of a system of contiguous organs including the nose, palate, rhinopharynx, and middle ear cleft. The middle ear cleft consists of the tympanic cavity, which includes the bony eustachian tube (protympanum) and the mastoid gas cells system. The tympanic cavity and mastoid gas cells are interconnected and allow gaseous exchange and pressure regulation. The fibrocartilaginous eustachian tube is a complex organ consisting of a dynamic conduit with its mucosa, cartilage, surrounding soft tissue, peritubal muscles (ie, tensor and levator veli palatine, salpingopharyngeus and tensor tympani), and superior bony support (the sphenoid sulcus). Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Closed-Tube Barcoding.

    PubMed

    Sirianni, Nicky M; Yuan, Huijun; Rice, John E; Kaufman, Ronit S; Deng, John; Fulton, Chandler; Wangh, Lawrence J

    2016-11-01

    Here, we present a new approach for increasing the rate and lowering the cost of identifying, cataloging, and monitoring global biodiversity. These advances, which we call Closed-Tube Barcoding, are one application of a suite of proven PCR-based technologies invented in our laboratory. Closed-Tube Barcoding builds on and aims to enhance the profoundly important efforts of the International Barcode of Life initiative. Closed-Tube Barcoding promises to be particularly useful when large numbers of small or rare specimens need to be screened and characterized at an affordable price. This approach is also well suited for automation and for use in portable devices.

  7. TJC: plan and prepare for the transition to new tubing connectors to minimize the risk of dangerous misconnections, clinician frustration.

    PubMed

    2014-12-01

    To reduce the risk of dangerous tubing misconnections, the ISO is rolling out new tubing connector standards that will eventually make it nearly impossible for tubing associated with one delivery system to be connected to a delivery system that serves a different purpose. Experts welcome the change, noting that tubing misconnections that cause injury and even death have been happening for years. However, TJC has issued a Sentinel Event Alert, warning that health care organizations need to be vigilant in managing the risk posed by these misconnections during the phased-in transition to the new connectors. Experts explain that tubing misconnections occur because many different types of tubing utilize the same Leur connector, making it possible for a clinician to mistakenly connect a tube to the wrong delivery system. The most common type of tubing misconnection reported to the ISMP is when a clinician wants to administer something to a patient through a feeding tube, but accidently administers the substance through an IV tube instead. The first new connector, called the ENFit, is going to be for enteral feeding tubes. It will not connect to IV tubing, making that type of misconnection unlikely. The new connector should be available early next year. Since hospitals will continue to use older tubing until their supplies are exhausted, manufacturers will temporarily provide adapters capable of making new administration sets compatible with older tubing.

  8. To Evaluate Effect of Airborne Particle Abrasion using Different Abrasives Particles and Compare Two Commercial Available Zirconia on Flexural Strength on Heat Treatment.

    PubMed

    Prasad, Hari A; Pasha, Naveed; Hilal, Mohammed; Amarnath, G S; Kundapur, Vinaya; Anand, M; Singh, Sumeet

    2017-06-01

    airborne-particle abrasion using 50 µm Al 2 O 3 particles and 50 µm silica coated Al 2 O 3 are applied to the upper and lower surfaces of the specimens. Each specimen is held under a pressure of 30 psi for 15 seconds at a direction perpendicular to the surface and at a distance of 30mm with an airborne particle abrasion device for the specimens in the airborne particle abraded groups. Heat treatments were performed at a starting temperature of 500°C, heating rate of 100°c/ min, ending at a temperature of 1000°C and 15 minutes holding time without vacuum for the specimens in the group 4, 5, 9 and 10. Airborne-particle abrasion mimicking the preparation for cementation was applied to the lower surfaces with 50 µm alumina and silica coated alumina particles for the specimens in the groups 6, 7, 8, 9 and 10. The specimens were cleaned for 15 minutes in an ultrasonic bath containing distilled water. To determine the fracture strength, a disc of 10 mm diameter was used to place 3 hardened steel balls of 3 mm diameter separated each other by 120 degrees (described in the ISO standard 6872 for dental ceramics). Each specimen was centrally placed on this disc. The lower surface mimicking the internal surface of zirconia was the tension side, facing the supporting device testing, while the upper surface mimicking the external surface of the zirconia core was loaded with a flat punch (1 mm in diameter). A universal testing machine was used to perform the test at a cross head speed of 1mm/min. The failure stress was calculated with the equation listed in ISO 6872. The results were then statistically analyzed. A post hoc test was used for pair wise comparisons. The mean fracture strength of commercially available Zirconia Ceramill (AMANNGIRBACH) showed a significant higher value compared to the ZR-White (UPCERA) Zirconia ( P <0.001), Airborne abrasion treatment to the specimens showed a significant difference between the abraded groups and the control group ( P <0.001); further

  9. To Evaluate Effect of Airborne Particle Abrasion using Different Abrasives Particles and Compare Two Commercial Available Zirconia on Flexural Strength on Heat Treatment

    PubMed Central

    Prasad, Hari A.; Pasha, Naveed; Hilal, Mohammed; Amarnath, G. S.; Kundapur, Vinaya; Anand, M; Singh, Sumeet

    2017-01-01

    specimens each. Heat treatment after airborne-particle abrasion using 50 µm Al2O3 particles and 50 µm silica coated Al2O3 are applied to the upper and lower surfaces of the specimens. Each specimen is held under a pressure of 30 psi for 15 seconds at a direction perpendicular to the surface and at a distance of 30mm with an airborne particle abrasion device for the specimens in the airborne particle abraded groups. Heat treatments were performed at a starting temperature of 500°C, heating rate of 100°c/ min, ending at a temperature of 1000°C and 15 minutes holding time without vacuum for the specimens in the group 4, 5, 9 and 10. Airborne-particle abrasion mimicking the preparation for cementation was applied to the lower surfaces with 50 µm alumina and silica coated alumina particles for the specimens in the groups 6, 7, 8, 9 and 10. The specimens were cleaned for 15 minutes in an ultrasonic bath containing distilled water. To determine the fracture strength, a disc of 10 mm diameter was used to place 3 hardened steel balls of 3 mm diameter separated each other by 120 degrees (described in the ISO standard 6872 for dental ceramics). Each specimen was centrally placed on this disc. The lower surface mimicking the internal surface of zirconia was the tension side, facing the supporting device testing, while the upper surface mimicking the external surface of the zirconia core was loaded with a flat punch (1 mm in diameter). A universal testing machine was used to perform the test at a cross head speed of 1mm/min. The failure stress was calculated with the equation listed in ISO 6872. The results were then statistically analyzed. A post hoc test was used for pair wise comparisons. Result: The mean fracture strength of commercially available Zirconia Ceramill (AMANNGIRBACH) showed a significant higher value compared to the ZR-White (UPCERA) Zirconia (P<0.001), Airborne abrasion treatment to the specimens showed a significant difference between the abraded groups and the

  10. Replacement of Mushroom Cage Gastrostomy Tube Using a Modified Technique to Allow Percutaneous Replacement with an Endoscopic Tube in Patients with Amyotrophic Lateral Sclerosis

    SciTech Connect

    Ammar, Thoraya; Rio, Alan; Ampong, Mary Ann

    2010-06-15

    Radiologic inserted gastrostomy (RIG) is the preferred method in our institution for enteral feeding in amyotrophic lateral sclerosis (ALS). Skin-level primary-placed mushroom cage gastrostomy tubes become tight with weight gain. We describe a minimally invasive radiologic technique for replacing mushroom gastrostomy tubes with endoscopic mushroom cage tubes in ALS. All patients with ALS who underwent replacement of a RIG tube were included. Patients were selected for a modified replacement when the tube length of the primary placed RIG tube was insufficient to allow like-for-like replacement. Replacement was performed under local anesthetic and fluoroscopic guidance according to a preset technique, withmore » modification of an endoscopic mushroom cage gastrostomy tube to allow percutaneous placement. Assessment of the success, safety, and durability of the modified technique was undertaken. Over a 60-month period, 104 primary placement mushroom cage tubes in ALS were performed. A total of 20 (19.2%) of 104 patients had a replacement tube positioned, 10 (9.6%) of 104 with the modified technique (male n = 4, female n = 6, mean age 65.5 years, range 48-85 years). All tubes were successfully replaced using this modified technique, with two minor complications (superficial wound infection and minor hemorrhage). The mean length of time of tube durability was 158.5 days (range 6-471 days), with all but one patient dying with a functional tube in place. We have devised a modification to allow percutaneous replacement of mushroom cage gastrostomy feeding tubes with minimal compromise to ALS patients. This technique allows tube replacement under local anesthetic, without the need for sedation, an important consideration in ALS.« less

  11. Influence of particle shedding from silicone tubing on antibody stability.

    PubMed

    Saller, Verena; Hediger, Constanze; Matilainen, Julia; Grauschopf, Ulla; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

    2018-05-01

    Peristaltic pumps are increasingly employed during fill & finish operations of a biopharmaceutical drug, due to sensitivity of many biological products to rotary piston pump-related stresses. Yet, possibly also unit operations using peristaltic pumps may shed particulates into the final product due to abrasion from the employed tubing. It was the aim of this study to elucidate the potential influence of particles shed from peristaltic pump tubing on the stability of a drug product. Spiking solutions containing shed silicone particles were prepared via peristaltic pumping of placebo under recirculating conditions and subsequently characterized. Two formulated antibodies were spiked with two realistic, but worst-case levels of particles and a 6-month accelerated stability study with storage at 2-8, 25 and 40°C were conducted. Regarding the formation of aggregates and fragments, both mAbs degraded at their typically expected rates and no additional impact of spiked particles was observed. No changes were discerned however in turbidity, subvisible and visible particle assessments. Flow imaging data for one of the mAb formulations with spiked particles suggested limited colloidal stability of shed particles as indicated by a similar increase in spiked placebo. Shed silicone particles from peristaltic pump tubing are assumed to not impair drug product stability. © 2016 Royal Pharmaceutical Society.

  12. A study on practical use of underwater abrasive water jet cutting

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hitoshi; Demura, Kenji

    1993-09-01

    The practicality of underwater abrasive water jet cutting technology was studied in experiments. A study of abrasives in slurried form showed that optimum polymer concentration can be selected to suit underwater conditions. For the long-distance transport of slurry from the ocean surface to the ocean floor, a direct supply system by hose proved to be practical. This system takes advantage of the insolubility of the slurry in water due to a difference in specific gravity. For cutting thick steel plate at great ocean depths, a simulation with a pressurized container revealed the requirements for actual cutting. Confirmation of remote cutting operations will become the most important technology in field applications. Underwater sound vibration characteristics were found to change significantly in direct response to modifications in cutting conditions. This will be important basic data to develop an effective sensoring method.

  13. A Study on 3-Body Abrasive Wear Behaviour of Aluminium 8011 / Graphite Metal Matrix Composite

    NASA Astrophysics Data System (ADS)

    Latha Shankar, B.; Anil, K. C.; Patil, Rahul

    2016-09-01

    Metals and alloys have found their vital role in many applications like structural, corrosive, tribological, etc., in engineering environment. The alloys/composites having high strength to low weight ratio have gained attention of many researchers recently. In this work, graphite reinforced Aluminium 8011 metal matrix composite was prepared by conventional stir casting route, by varying the weight % of reinforcement. Uniform distribution of Graphite in matrix alloy was confirmed by optical micrographs. Prepared composite specimens were subjected to 3-body abrasive testing by varying applied load and time, the silica particles of 400 grit size were used as abrasive particles. It was observed that with the increase of weight% of Graphite the wear resistance of composite was also increasing and on comparison it was found that reinforced composite gives good wear resistance than base alloy.

  14. Influence of Surface Abrasion on Creep and Shrinkage of Railway Prestressed Concrete Sleepers

    NASA Astrophysics Data System (ADS)

    Li, Dan; Ngamkhanong, Chayut; Kaewunruen, Sakdirat

    2017-10-01

    Ballasted railway track is very suitable for heavy-rail networks because of its many superior advantages in design, construction, short- and long-term maintenance, sustainability, and life-cycle cost. The sleeper, which supports rail and distributes loads from rail to ballast, is a very important component of rail track system. Prestressed concrete is very popular used in manufacturing sleepers. Therefore, improved knowledge about design techniques for prestressed concrete (PC) sleepers has been developed. However, the ballast angularity causes differential abrasions on the soffit or bottom surface of sleepers. Furthermore, in sharp curves and rapid gradient change, longitudinal and lateral dynamics of rails increase the likelihood of abrasions in concrete sleepers. This paper presents a comparative investigation using a variety of methods to evaluate creep and shrinkage effects in railway prestressed concrete sleepers. The outcome of this study will improve the material design, which is very critical to the durability of railway track components.

  15. Correlating field and laboratory rates of particle abrasion, Rio Medio, Sangre de Cristo Mountains, New Mexico

    NASA Astrophysics Data System (ADS)

    Polito, P. J.; Sklar, L. S.

    2006-12-01

    River bed sediments commonly fine downstream due to a combination of particle abrasion, selective transport of finer grains, and fining of the local sediment supply from hillslopes and tributaries. Particle abrasion rates can be directly measured in the laboratory using tumbling barrels and annular flumes, however, scaling experimental particle abrasion rates to the field has proven difficult due to the confounding effects of selective transport and local supply variations. Here we attempt to correlate laboratory and field rates of particle abrasion in a field setting where these confounding effects can be controlled. The Rio Medio, which flows westward from the crest of the Sangre de Cristo Mountains in north central New Mexico, is one of several streams studied by John P. Miller in the early 1960's. Several kilometers downstream of its headwaters, the river crosses the Picuris-Pecos fault. Upstream of the fault the river receives quartzite, sandstone and shale clasts from the Ortega Formation, while downstream sediments are supplied by the Embudo Granite. Because the upstream lithologies are not resupplied downstream of the fault, any observed fining of these clasts should be due only to abrasion and selective transport. We hypothesize that we can account for the effects of selective transport by comparing relative fining rates for the different upstream lithologies from both the field and a laboratory tumbler. By correlating laboratory abrasion rates with rock strength, we can predict the relative fining rates due solely to abrasion expected in the field; differences between the predicted and observed fining rates could then be attributed to selective transport. We used point counts to measure bed surface sediment grain size distributions at 15 locations along a 25 kilometer reach of the Rio Medio, beginning just downstream of the fault and ending upstream of a developed area with disturbed channel conditions. We recorded intermediate particle diameter as well

  16. Erosion and abrasion on dental structures undergoing at-home bleaching

    PubMed Central

    Demarco, Flávio Fernando; Meireles, Sônia Saeger; Sarmento, Hugo Ramalho; Dantas, Raquel Venâncio Fernandes; Botero, Tatiana; Tarquinio, Sandra Beatriz Chaves

    2011-01-01

    This review investigates erosion and abrasion in dental structures undergoing at- home bleaching. Dental erosion is a multifactorial condition that may be idiopathic or caused by a known acid source. Some bleaching agents have a pH lower than the critical level, which can cause changes in the enamel mineral content. Investigations have shown that at-home tooth bleaching with low concentrations of hydrogen or carbamide peroxide have no significant damaging effects on enamel and dentin surface properties. Most studies where erosion was observed were in vitro. Even though the treatment may cause side effects like sensitivity and gingival irritation, these usually disappear at the end of treatment. Considering the literature reviewed, we conclude that tooth bleaching agents based on hydrogen or carbamide peroxide have no clinically significant influence on enamel/dentin mineral loss caused by erosion or abrasion. Furthermore, the treatment is tolerable and safe, and any adverse effects can be easily reversed and controlled. PMID:23674914

  17. Self-healing of the superhydrophobicity by ironing for the abrasion durable superhydrophobic cotton fabrics

    PubMed Central

    Wu, Jingxia; Li, Jingye; Deng, Bo; Jiang, Haiqing; Wang, Ziqiang; Yu, Ming; Li, Linfan; Xing, Chenyang; Li, Yongjin

    2013-01-01

    Self-healing of the superhydrophobic cotton fabric (SCF) obtained by the radiation-induced graft polymerization of lauryl methacrylate (LMA) and n-hexyl methacrylate (HMA), can be achieved by ironing. Through the steam ironing process, the superhydrophobicity of the SCFs will be regenerated even after the yarns are ruptured during the abrasion test under a load pressure of 44.8 kPa. SCFs made from LMA grafted cotton fabric can ultimately withstand at least 24,000 cycles of abrasion with periodic steam ironing. The FT-IR microscope results show that the migration of the polymethacrylates graft chains from the interior to the surface is responsible for the self-healing effect. PMID:24135813

  18. Degradation of the Crystalline Structure of ZnS Ceramics under Abrasive Damage

    NASA Astrophysics Data System (ADS)

    Shcherbakov, I. P.; Dunaev, A. A.; Chmel, A. E.

    2018-04-01

    Stability of optical elements based on ZnS ceramics to dust and rain erosion is usually estimated from the loss of material mass in a directional flow of solid particles or atmospheric precipitates. In this case, the mechanism of degradation and fracture of the surface layer of an optical element is not considered. The photoluminescence (PL) method was used for investigating the crystal lattice response to the abrasive action and the formation of cleavage in ZnS ceramics, which differ in manufacturing technology and, accordingly, in the grain size by two orders of magnitude. It is shown that during abrasive treatment of samples, their spectra exhibit changes typical of degradation of the crystal lattice of material grains. The PL spectra of cleavage surfaces reveal almost complete degradation of the structure of crystallite grains with a size from 1-2 to 100-200 μm.

  19. Chest tube insertion

    MedlinePlus

    ... leaks from inside the lung into the chest ( pneumothorax ) Fluid buildup in the chest (called a pleural ... on the reason a chest tube is inserted. Pneumothorax most often improves, but sometimes surgery is needed ...

  20. Tube Alinement for Machining

    NASA Technical Reports Server (NTRS)

    Garcia, J.

    1984-01-01

    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. Eustachian tube patency

    MedlinePlus

    ... to become blocked. Images Ear anatomy Eustachian tube anatomy References Kerschner JE, Preciado D. Otitis media. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016: ...

  2. Tube-Forming Assays.

    PubMed

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

    2016-01-01

    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.

  3. Bull Moose Tube Company

    EPA Pesticide Factsheets

    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,

  4. Integrated structure vacuum tube

    NASA Technical Reports Server (NTRS)

    Dimeff, J.; Kerwin, W. J. (Inventor)

    1976-01-01

    High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Anode and grid members are formed using thin films of refractory metal. Electron flow in the tubes is between grid elements from cathode to anode as in a conventional three-dimensional tube.

  5. Validation of Proposed Metrics for Two-Body Abrasion Scratch Test Analysis Standards

    NASA Technical Reports Server (NTRS)

    Kobrick, Ryan L.; Klaus, David M.; Street, Kenneth W., Jr.

    2011-01-01

    The objective of this work was to evaluate a set of standardized metrics proposed for characterizing a surface that has been scratched from a two-body abrasion test. This is achieved by defining a new abrasion region termed Zone of Interaction (ZOI). The ZOI describes the full surface profile of all peaks and valleys, rather than just measuring a scratch width as currently defined by the ASTM G 171 Standard. The ZOI has been found to be at least twice the size of a standard width measurement, in some cases considerably greater, indicating that at least half of the disturbed surface area would be neglected without this insight. The ZOI is used to calculate a more robust data set of volume measurements that can be used to computationally reconstruct a resultant profile for detailed analysis. Documenting additional changes to various surface roughness parameters also allows key material attributes of importance to ultimate design applications to be quantified, such as depth of penetration and final abraded surface roughness. Data are presented to show that different combinations of scratch tips and abraded materials can actually yield the same scratch width, but result in different volume displacement or removal measurements and therefore, the ZOI method is more discriminating than the ASTM method scratch width. Furthermore, by investigating the use of custom scratch tips for our specific needs, the usefulness of having an abrasion metric that can measure the displaced volume in this standardized manner, and not just by scratch width alone, is reinforced. This benefit is made apparent when a tip creates an intricate contour having multiple peaks and valleys within a single scratch. This work lays the foundation for updating scratch measurement standards to improve modeling and characterization of three-body abrasion test results.

  6. Heat sealable, flame and abrasion resistant coated fabric. [clothing and containers for space exploration

    NASA Technical Reports Server (NTRS)

    Tschirch, R. P.; Sidman, K. R. (Inventor)

    1981-01-01

    Flame retardant, abrasion resistant elastomeric compositions are comprised of thermoplastic polyurethane polymer and flame retarding amounts of a filler selected from decabromodiphenyloxide and antimony oxide in a 3:1 weight ratio, and decabromodiphenyloxide, antimony oxide, and ammonium polyphosphate in a 3:1:3 weight ratio respectively. Coated fabrics employing such elastomeric compositions as coating film are flexible, lightweight, and air impermeable and can be made using heat or dielectric sealing procedures.

  7. Abrasive wear of resin composites as related to finishing and polishing procedures.

    PubMed

    Turssi, Cecilia P; Ferracane, Jack L; Serra, Mônica C

    2005-07-01

    Finishing and polishing procedures may cause topographical changes and introduce subsurface microcracks in dental composite restoratives. Since both of these effects may contribute toward the kinetics of wear, the purpose of this study was to assess and correlate the wear and surface roughness of minifilled and nanofilled composites finished and polished by different methods. Specimens (n=10) made of a minifilled and a nanofilled composite were finished and polished with one of the four sequences: (1) tungsten carbide burs plus Al(2)O(3)-impregnated brush (CbBr) or (2) tungsten carbide burs plus diamond-impregnated cup (CbCp), (3) diamond burs plus brush (DmBr) or (4) diamond burs plus cup (DmCp). As a control, abrasive papers were used. After surface roughness had been quantified, three-body abrasion was simulated using the OHSU wear machine. The wear facets were then scanned to measure wear depth and post-testing roughness. All sets of data were subjected to ANOVA and Tukey's tests (alpha=0.05). Pearson's correlation test was applied to check for the existence of a relationship between pre-testing roughness and wear. Significantly smoother surfaces were attained with the sequences CbBr and CbCp, whereas DmCp yielded the roughest surface. Regardless of the finishing/polishing technique, the nanofilled composite exhibited the lowest pre-testing roughness and wear. There was no correlation between the surface roughness achieved after finishing/polishing procedures and wear (p=0.3899). Nano-sized materials may have improved abrasive wear resistance over minifilled composites. The absence of correlation between wear and surface roughness produced by different finishing/polishing methods suggests that the latter negligibly influences material loss due to three-body abrasion.

  8. Framework for assessing key variable dependencies in loose-abrasive grinding and polishing

    SciTech Connect

    Taylor, J.S.; Aikens, D.M.; Brown, N.J.

    1995-12-01

    This memo describes a framework for identifying all key variables that determine the figuring performance of loose-abrasive lapping and polishing machines. This framework is intended as a tool for prioritizing R&D issues, assessing the completeness of process models and experimental data, and for providing a mechanism to identify any assumptions in analytical models or experimental procedures. Future plans for preparing analytical models or performing experiments can refer to this framework in establishing the context of the work.

  9. Toothbrush abrasion, simulated tongue friction and attrition of eroded bovine enamel in vitro.

    PubMed

    Vieira, A; Overweg, E; Ruben, J L; Huysmans, M C D N J M

    2006-05-01

    Enamel erosion results in the formation of a softened layer that is susceptible to disruption by mechanical factors such as brushing abrasion, tongue friction and attrition. The aim of this study was to investigate the individual contribution of those mechanical insults to the enamel loss caused by dental erosion. Forty two bovine enamel samples were randomly divided into seven groups (n=6 per group) that were submitted to 3cycles of one of the following regimes: erosion and remineralization (er/remin); toothbrush abrasion and remineralization (abr/remin); erosion, toothbrush abrasion and remineralization (er/abr/remin); attrition and remineralization (at/remin); erosion, attrition and remineralization (er/at/remin); simulated tongue friction and remineralization (tg/remin); erosion, simulated tongue friction and remineralization (er/tg/remin). Erosion took place in a demineralization solution (50mM citric acid, pH 3) for 10min under agitation. Brushing abrasion, tongue friction and attrition were simulated for 1min using a home-made wear device. Remineralization was carried out in artificial saliva for 2h. Enamel loss was quantified using optical profilometry. One-way ANOVA indicated a significant difference between the amounts of enamel lost due to the different wear regimes (p

  10. Relating the physical properties of volcanic rocks to the characteristics of ash generated by experimental abrasion

    NASA Astrophysics Data System (ADS)

    Buckland, Hannah M.; Eychenne, Julia; Rust, Alison C.; Cashman, Katharine V.

    2018-01-01

    Interactions between clasts in pyroclastic density currents (PDCs) generate volcanic ash that can be dispersed to the atmosphere in co-PDC plumes, and due to its small size, is far-travelled. We designed a series of experiments to determine the effects of pyroclast vesicularity and crystal content on the efficiency and type of ash generated by abrasion. Two different pyroclastic materials were used: (1) basaltic-andesite pyroclasts from Fuego volcano (Guatemala) with 26-46% vesicularity and high groundmass crystallinity and (2) tephri-phonolite Avellino pumice (Vesuvius, Italy) with 55-75% vesicularity and low groundmass crystallinity. When milled, both clast types produced bimodal grain size distributions with fine ash modes between 4 and 5φ (32-63 μm). Although the vesicular Avellino pumice typically generated more ash than the denser Fuego pyroclasts, the ash-generating potential of a single pyroclast was independent of density, and instead governed by heterogeneous crystal and vesicle textures. One consequence of these heterogeneities was to cause the vesicular Avellino clasts to split in addition to abrading, which further enhanced abrasion efficiency. The matrix characteristics also affected ash shape and componentry, which will influence the elutriation and transport properties of ash in the atmosphere. The experimental abrasion successfully replicated some of the characteristics of natural co-PDC ash samples, as shown by similarities in the Adherence Factor, which measures the proportion of attached matrix on phenocrysts, of both the experimentally generated ash and natural co-PDC ash samples. Our results support previous studies, which have shown that abrasion is an effective mechanism for generating fine ash that is similar in size ( 5φ; 30 μm) to that found in co-PDC deposits. We further show that both the abundance and nature (shape, density, components, size distribution) of those ash particles are strongly controlled by the matrix properties of

  11. Abrasive Wear Resistance of Tool Steels Evaluated by the Pin-on-Disc Testing

    NASA Astrophysics Data System (ADS)

    Bressan, José Divo; Schopf, Roberto Alexandre

    2011-05-01

    Present work examines tool steels abrasion wear resistance and the abrasion mechanisms which are one main contributor to failure of tooling in metal forming industry. Tooling used in cutting and metal forming processes without lubrication fails due to this type of wear. In the workshop and engineering practice, it is common to relate wear resistance as function of material hardness only. However, there are others parameters which influences wear such as: fracture toughness, type of crystalline structure and the occurrence of hard precipitate in the metallic matrix and also its nature. In the present investigation, the wear mechanisms acting in tool steels were analyzed and, by normalized tests, wear resistance performance of nine different types of tool steels were evaluated by pin-on-disc testing. Conventional tool steels commonly used in tooling such as AISI H13 and AISI A2 were compared in relation to tool steels fabricated by sintering process such as Crucible CPM 3V, CPM 9V and M4 steels. Friction and wear testing were carried out in a pin-on-disc automated equipment which pin was tool steel and the counter-face was a abrasive disc of silicon carbide. Normal load of 5 N, sliding velocity of 0.45 m/s, total sliding distance of 3000 m and room temperature were employed. The wear rate was calculated by the Archard's equation and from the plotted graphs of pin cumulated volume loss versus sliding distance. Specimens were appropriately heat treated by quenching and three tempering cycles. Percentage of alloying elements, metallographic analyses of microstructure and Vickers microhardness of specimens were performed, analyzed and correlated with wear rate. The work is concluded by the presentation of a rank of tool steel wear rate, comparing the different tool steel abrasion wear resistance: the best tool steel wear resistance evaluated was the Crucible CPM 9V steel.

  12. Comparison between different interdental stripping methods and evaluation of abrasive strips: SEM analysis.

    PubMed

    Grippaudo, Cristina; Cancellieri, Daniela; Grecolini, Maria E; Deli, Roberto

    2010-01-01

    The aim of this study was to evaluate the morphological effects and the surface irregularities produced by different methods of mechanical stripping (abrasive strips and burs) and chemical stripping (37% orthophosphoric acid) and the surface changes following the finishing procedures (polishing strips) or the subsequent application of sealants, in order to establish the right stripping method that can guarantee the smoothest surface. We have also analysed the level of wear on the different abrasive strips employed, according to their structure. 160 proximal surfaces of 80 sound molar teeth extracted for orthodontic and periodontal reasons, were divided into: 1 control group with non-treated enamel proximal surfaces and 5 different groups according to the stripping method used, were observed with scanning electron microscopy (SEM). Each one of the 5 treated groups was also divided into 3 different subgroups according to the finishing procedures or the subsequent application of sealants. The finishing stage following the manual reduction proves to be fundamental in reducing the number and depth of grooves created by the stripping. After the air rotor stripping method, the use of sealants is advised in order to obtain a smoother surface. The analysis of the combinations of mechanical and chemical stripping showed unsatisfactory results. Concerning the wear of the strips, we have highlighted a different abrasion degree for the different types of strips analysed with SEM. The enamel damages are limited only if the finishing procedure is applied, independently of the type of abrasive strip employed. It would be advisable, though clinically seldom possible, the use of sealants after the air rotor stripping technique. Copyright © 2010 Società Italiana di Ortodonzia SIDO. Published by Elsevier Srl. All rights reserved.

  13. Process for producing a well-adhered durable optical coating on an optical plastic substrate. [abrasion resistant polymethyl methacrylate lenses

    NASA Technical Reports Server (NTRS)

    Kubacki, R. M. (Inventor)

    1978-01-01

    A low temperature plasma polymerization process is described for applying an optical plastic substrate, such as a polymethyl methacrylate lens, with a single layer abrasive resistant coating to improve the durability of the plastic.

  14. Toothbrush abrasion of paint-on resins for shade modification and crown resins: effect of water absorption.

    PubMed

    Fujii, Koichi; Arikawa, Hiroyuki; Kanie, Takahito; Ban, Seiji

    2004-06-01

    In order to investigate the clinical application of paint-on resins, the effect of water absorption on toothbrush abrasion and light transmittance of ten crown resins including three paint-on resins was examined. Water absorption into each material ranged from 0.29 to 0.89 mg/cm2 after storage in distilled-water for 6 weeks and their hardnesses decreased by 3.5-22.3%. Maximum surface roughness (Rmax) of the materials stored in distilled water for 6 weeks increased with an increasing number of toothbrush abrasion cycles and ranged from 1.9 to 10.5 microm after 100,000 cycles. Also, Maximum depth and weight loss as an indicator of the amount of each material lost by abrasion showed similar behaviors similar to Rmax. These results indicated that the abrasion resistance of paint-on resins was located in the middle among all materials examined.

  15. Theoretical study on removal rate and surface roughness in grinding a RB-SiC mirror with a fixed abrasive.

    PubMed

    Wang, Xu; Zhang, Xuejun

    2009-02-10

    This paper is based on a microinteraction principle of fabricating a RB-SiC material with a fixed abrasive. The influence of the depth formed on a RB-SiC workpiece by a diamond abrasive on the material removal rate and the surface roughness of an optical component are quantitatively discussed. A mathematical model of the material removal rate and the simulation results of the surface roughness are achieved. In spite of some small difference between the experimental results and the theoretical anticipation, which is predictable, the actual removal rate matches the theoretical prediction very well. The fixed abrasive technology's characteristic of easy prediction is of great significance in the optical fabrication industry, so this brand-new fixed abrasive technology has wide application possibilities.

  16. Tubing crimping pliers

    DOEpatents

    Lindholm, G.T.

    1981-02-27

    The disclosure relates to pliers and more particularly to pliers for crimping two or more pieces of copper tubing together prior to their being permanently joined by brazing, soldering or the like. A die containing spring-loaded pins rotates within a cammed ring in the head of the pliers. As the die rotates, the pins force a crimp on tubing held within the pliers.

  17. Tube Failure Mechanisms.

    DTIC Science & Technology

    studies will be made: ( a ) An investigation of the factors influencing electrical breakdown in a vacuum and across the surface of a dielectric. (b) An...The purpose of this program is to investigate the nature and the principal causes of failures in microwave tubes. In this context, the following...investigation of the various electrical and surface properties of materials commonly used in microwave tubes, i.e., OFHC copper, alumina ceramic, tungsten

  18. Analysis of Tube Hydroforming by means of an Inverse Approach

    SciTech Connect

    Nguyen, Ba Nghiep; Johnson, Kenneth I.; Khaleel, Mohammad A.

    2003-05-01

    This paper presents a computational tool for the analysis of freely hydroformed tubes by means of an inverse approach. The formulation of the inverse method developed by Guo et al. is adopted and extended to the tube hydrofoming problems in which the initial geometry is a round tube submitted to hydraulic pressure and axial feed at the tube ends (end-feed). A simple criterion based on a forming limit diagram is used to predict the necking regions in the deformed workpiece. Although the developed computational tool is a stand-alone code, it has been linked to the Marc finite element code formore » meshing and visualization of results. The application of the inverse approach to tube hydroforming is illustrated through the analyses of the aluminum alloy AA6061-T4 seamless tubes under free hydroforming conditions. The results obtained are in good agreement with those issued from a direct incremental approach. However, the computational time in the inverse procedure is much less than that in the incremental method.« less

  19. Effect of consolidation on adhesive and abrasive wear of ultra high molecular weight polyethylene.

    PubMed

    Gul, Rizwan M; McGarry, Frederick J; Bragdon, Charles R; Muratoglu, Orhun K; Harris, William H

    2003-08-01

    Total hip replacement (THR) is widely performed to recover hip joint functions lost by trauma or disease and to relieve pain. The major cause of failure in THR is the wear of the ultra high molecular weight polyethylene (UHMWPE) component. The dominant wear mechanism in THR occurs through adhesion and abrasion. While poor consolidation of UHMWPE is known to increase the incidence of a different damage mode, delamination, which is the dominant wear mechanism in tibial inserts but uncommon in THR, the effect of consolidation on adhesive and abrasive wear of UHMWPE is not clear. In this study UHMWPE resin was subjected to hot isostatic pressing under a pressure of 138MPa at different temperatures (210 degrees C, 250 degrees C, and 300 degrees C) to achieve varying degrees of consolidation. The extent of consolidation was determined by optical microscopy using thin sections, and by scanning electron microscopy using cryofractured and solvent etched specimens. Wear behavior of the samples with varying degree of consolidation was determined using a bi-directional pin-on-disc machine simulating conditions in a hip joint. Increasing the processing temperature decreased the incidence of fusion defects and particle boundaries reflecting the powder flakes of the virgin resin, improving the consolidation. However, the bi-directional pin-on-disc wear rate did not change with the processing temperature, indicating that adhesive and abrasive wear is independent of the extent of consolidation in the range of parameters studied here.

  20. Influence of sodium content on the properties of bioactive glasses for use in air abrasion.

    PubMed

    Farooq, Imran; Tylkowski, Maxi; Müller, Steffen; Janicki, Tomasz; Brauer, Delia S; Hill, Robert G

    2013-12-01

    Air abrasion is used in minimally invasive dentistry for preparing cavities, while removing no or little sound dentine or enamel, and the use of bioactive glass (rather than alumina) as an abrasive could aid in tooth remineralization. Melt-derived bioactive glasses (SiO2-P2O5-CaO-CaF2-Na2O) with low sodium content (0 to 10 mol% Na2O in exchange for CaO) for increased hardness, high phosphate content for high bioactivity and fluoride content for release of fluoride and formation of fluorapatite were produced, and particles between 38 and 80 µm in size were used for cutting soda-lime silicate glass microscope slides and human enamel. Vickers hardness increased with decreasing Na2O content, owing to a more compact silicate network in low sodium content glasses, resulting in shorter cutting times. Cutting times using bioactive glass were significantly longer than using the alumina control (29 µm) when tested on microscope slides; however, glasses showed more comparable results when cutting human enamel. The bioactive glasses formed apatite in Tris buffer within 6 h, which was significantly faster than Bioglass® 45S5 (24 h), suggesting that the hardness of the glasses makes them suitable for air abrasion application, while their high bioactivity and fluoride content make them of interest for tooth remineralization.