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Sample records for abrasive feed tube

  1. Feeding Tubes

    MedlinePlus

    ... administer the TPN. Tubes Used for Enteral Feeds NG (Nasogastric Tube) A flexible tube is placed via ... down through the esophagus into the stomach. The NG tube can be used to empty the stomach ...

  2. 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…

  3. Nasogastric feeding tube

    MedlinePlus

    Feeding - nasogastric tube; NG tube; Bolus feeding; Continuous pump feeding; Gavage tube ... A nasogastric tube (NG tube) is a special tube that carries food and medicine to the stomach through the nose. It can be ...

  4. Tube Feeding Troubleshooting Guide

    MedlinePlus

    ... profile tube also has a stem length). Note: NG and NJ tubes (that go through a person’s ... Immediate Action: • Discontinue feeding. • If you have an NG or NJ tube, and the tube is curled ...

  5. 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…

  6. Gastrostomy feeding tube - pump - child

    MedlinePlus

    ... supplies: Feeding pump (electronic or battery powered) Feeding set that matches the feeding pump (includes a feeding ... drip chamber, roller clamp, and long tube) Extension set, for a Bard Button or MIC-KEY (this ...

  7. Gastrostomy feeding tube - pump - child

    MedlinePlus

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

  8. Clogging of feeding tubes.

    PubMed

    Marcuard, S P; Perkins, A M

    1988-01-01

    This is a report of an in vitro study evaluating clotting ability of some formulas with intact protein and hydrolyzed protein sources in a series of buffers ranging from a pH of 1 thru 10. The following 10 products were tested: Ensure Plus, Ensure, Enrich, Osmolite, Pulmocare, Citrotein, Resource, Vivonex TEN, Vital, and Hepatic Acid II. Protein (10 and 20 g/liter) was added to Citrotein and Ensure Plus. All formulas were tested at full and some at half strength. Clotting occurred only in premixed intact protein formulas (Pulmocare, Ensure Plus, Osmolite, Enrich, Ensure) and in Resource. No clotting was observed for Citrotein (intact protein formula in powder form), Vital, Vivonex TEN, and Hepatic Aid II. Adding protein did not cause or increase clotting. In summary, clotting of some liquid formula diet appears to be an important factor causing possible gastric feeding tube occlusion. The following measures may help in preventing this problem: flushing before and after aspirating for gastric residuals to eliminate acid precipitation of formula in the feeding tube, advance the nasogastric feeding tube into the duodenum if possible, and avoid mixing these products with liquid medications having a pH value of 5.0 or less. PMID:3138452

  9. Feeding tube insertion - gastrostomy

    MedlinePlus

    ... tube insertion; G-tube insertion; PEG tube insertion; Stomach tube insertion; Percutaneous endoscopic gastrostomy tube insertion ... and down the esophagus, which leads to the stomach. After the endoscopy tube is inserted, the skin ...

  10. 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…

  11. 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 ...

  12. 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

  13. Dietitians and small bowel feeding tube placement.

    PubMed

    Marsland, Cheryl

    2010-06-01

    Some advanced practice nutrition support dietitians have added small bowel feeding tube placement to their scope of responsibility. This is due, in part, to the challenges of gaining early enteral access in patients with functioning GI tracts. Emerging literature supports the practice of skilled practitioners placing feeding tubes at bedside. A variety of methods can be used to place tubes at the bedside. The nutrition support dietitian must understand licensure and liability considerations to perform this invasive procedure. This article will review literature reports of dietitians placing feeding tubes and provide information on the methods used, training and competencies required, and legal issues involved. PMID:20581321

  14. Fewer Advanced Alzheimer's Patients on Feeding Tubes

    MedlinePlus

    ... at someone in the advanced stages of a terminal illness, a feeding tube doesn't make a ... of palliative care (keeping a person with a terminal illness as comfortable as possible), Mitchell said. As ...

  15. Advanced Illness: Feeding Tubes and Ventilators

    MedlinePlus

    ... Address, Jewish Lights Publishing, 2000. www.jewishlights.com Bioethics , Thomas Shannon, ed. Paulist Press, 2009 Swallowing Problems , ... 2004 The Feeding Tube Dilemma, The Center for Bioethics and Human Dignity, 1/27/06, cbhd.org ...

  16. American Geriatrics Society feeding tubes in advanced dementia position statement.

    PubMed

    2014-08-01

    When eating difficulties arise, feeding tubes are not recommended for older adults with advanced dementia. Careful hand feeding should be offered because hand feeding has been shown to be as good as tube feeding for the outcomes of death, aspiration pneumonia, functional status, and comfort. Moreover, tube feeding is associated with agitation, greater use of physical and chemical restraints, healthcare use due to tube-related complications, and development of new pressure ulcers. Efforts to enhance oral feeding by altering the environment and creating patient-centered approaches to feeding should be part of usual care for older adults with advanced dementia. Tube feeding is a medical therapy that an individual's surrogate decision-maker can decline or accept in accordance with advance directives, previously stated wishes, or what it is thought the individual would want. It is the responsibility of all members of the healthcare team caring for residents in long-term care settings to understand any previously expressed wishes of the individuals (through review of advance directives and with surrogate caregivers) regarding tube feeding and to incorporate these wishes into the care plan. Institutions such as hospitals, nursing homes, and other care settings should promote choice, endorse shared and informed decision-making, and honor preferences regarding tube feeding. They should not impose obligations or exert pressure on individuals or providers to institute tube feeding. PMID:25039796

  17. Central Venous Access Catheters (CVAC) and Gastrostomy (Feeding) Tubes

    MedlinePlus

    ... Membership Directory (SIR login) Interventional Radiology Central Venous Access Catheters (CVAC) and Gastrostomy (Feeding) Tubes People with ... without surgery by an interventional radiologist. Central Venous Access Catheters (CVAC) A CVAC is a tube that ...

  18. Modification of polyurethane to reduce occlusion of enteral feeding tubes

    SciTech Connect

    Gaither, Kari A.; Tarasevich, Barbara J.; Goheen, Steven C.

    2009-04-27

    Feeding tubes are used to supply nutritional formula to immobilized patients. The most common cause for failure of enteral feeding tubes is their occlusion. The purpose of this study was to examine whether occlusion of enteral feeding tubes could be minimized using an additive. An open, intermittent enteral feeding system was simulated in the laboratory and data was collected over a period ranging from 2 to 6 days. Feeding formula was cycled through a feeding tube in either the presence or absence of simulated gastric acid in an effort to generate a reproducible occlusion. Pressures in the tube were measured frequently throughout these cycles. We observed pressure spikes with each cycle, but never a complete occlusion. Pressure spikes formed only when simulated gastric acid was mixed with the feeding solution. Large amounts of feeding formula adsorbed onto polyurethane surfaces in the presence of gastric acid. The maximum pressure was reduced by about half from 2.0 psi to 0.8 psi when polyvinyl alcohol (PVA) was added. The addition of PVA to polyurethane also reduced the contact angle from 83° (untreated) to approximately 64° in the presence of PVA. Furthermore, when formula was added to polyurethane in the presence of PVA the thickness of the layer that remained on the surface was almost 10 times greater in controls than on PVA-treated surfaces. These results suggest that a treatment that increases the hydrophilicity of the feeding tube may help minimize clogging.

  19. Reduce - and Report - Enteral Feeding Tube Misconnections

    MedlinePlus

    ... patient requiring mechanical ventilation also had a nasogastric (NG) tube in place. After being transported to another ... high-flow oxygen was accidentally connected to the NG tube. The patient subsequently underwent emergency surgery to ...

  20. Percutaneous feeding tube method for use in children.

    PubMed

    Long, B; Rafert, J; Cory, D

    1991-01-01

    Surgical gastrostomy has been a widely accepted method for introducing a percutaneous feeding tube for many years. However, complications are frequent, and many children who need them are not good surgical candidates. This study examines imaging guided percutaneous placement of feeding gastrostomy catheters as a safe and effective alternative to surgery. PMID:1902957

  1. Evaluation of a new method for placing nasojejunal feeding tubes

    PubMed Central

    Qin, Hua; Lu, Xiao-Yun; Zhao, Qiu; Li, De-Min; Li, Pei-Yuan; Liu, Mei; Zhou, Qi; Zhu, Liang; Pang, Hui-Fang; Zhao, Hui-Zhen

    2012-01-01

    AIM: To compare fluoroscopic, endoscopic and guide wire assistance with ultraslim gastroscopy for placement of nasojejunal feeding tubes. METHODS: The information regarding nasojejunal tube placement procedures was retrieved using the gastrointestinal tract database at Tongji Hospital affiliated to Tongji Medical College. Records from 81 patients who underwent nasojejunal tubes placement by different techniques between 2004 and 2011 were reviewed for procedure success and tube-related outcomes. RESULTS: Nasojejunal feeding tubes were successfully placed in 78 (96.3%) of 81 patients. The success rate by fluoroscopy was 92% (23 of 25), by endoscopic technique 96.3% (26 of 27), and by guide wire assistance (whether via transnasal or transoral insertion) 100% (23/23, 6/6). The average time for successful placement was 14.9 ± 2.9 min for fluoroscopic placement, 14.8 ± 4.9 min for endoscopic placement, 11.1 ± 2.2 min for guide wire assistance with transnasal gastroscopic placement, and 14.7 ± 1.2 min for transoral gastroscopic placement. Statistically, the duration for the third method was significantly different (P < 0.05) compared with the other three methods. Transnasal placement over a guidewire was significantly faster (P < 0.05) than any of the other approaches. CONCLUSION: Guide wire assistance with transnasal insertion of nasojejunal feeding tubes represents a safe, quick and effective method for providing enteral nutrition. PMID:23066326

  2. 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…

  3. Evaluation of Tube Wall Thickness of Feed Water Heater

    NASA Astrophysics Data System (ADS)

    Uchikura, Takahisa; Morisaki, Koichi; Hamada, Seiichi

    With regard to the high pressure (HP) feed water heater of thermal power plant at Tokyo Electric Power Company (TEPCO) sites, inspection of feed water (FW) tubes wall thickness are conducted whenever required such that frequent tube leak occurs. As a standard inspection methodology, FW heater is disassembled during planned outage, tube wall thickness is measured by the ultrasonic pulse techique (UT), then plugs are installed at the both ends of FW tube if its measured wall thickness is found below calculated threshold. However, the root causes of wall thinning of FW tube are various such as erosion and corrosion, based on wall thinning condition, the above threshold is not applied but utilizing the other technically well-grounded evaluation method is sometimes more rational. Therefore, TEPCO classified wall-thinning condition based on inspection data and established technically well-grounded and rational evaluation methodologies of FW tube wall thickness to suite each wall thinning condition. Moreover, with recent improvement of inspection technique, technology enabled faster, larger amount, and more accurate data acquisition, TEPCO has developed the systematized evaluation methodology that can transact data acquisition and evaluation simultaneously. This article introduces the logic of evaluation methods and examined algorithms to make them systematized.

  4. Deoxynivalenol removal from barley intended as swine feed through the use of an abrasive pearling procedure.

    PubMed

    House, James D; Nyachoti, Charles Martin; Abramson, David

    2003-08-13

    Samples of naturally contaminated hulled barley, with varying deoxynivalenol concentrations, were subjected to an abrasive type dehulling procedure. The remaining grain fractions were analyzed for weight remaining (%), deoxynivalenol (ppm), crude protein (%CP), neutral detergent fiber (%NDF), ash (%ASH), gross energy (GE; kcal/kg), and calculated digestible energy values (DE; kcal/kg). Following the initial 15 s of pearling, 85% of the grain mass remained. Additional pearling resulted in a linear decline of grain mass. Following 15 s of pearling, the grain contained 34% of the initial deoxynivalenol content, irrespective of the initial level of contamination. Further pearling resulted in continued significant (p < 0.05) reductions in the percent of deoxynivalenol remaining to a level of 7.9% after 120 s but with significant losses in grain mass. Pearling can serve as an effective means of reducing the deoxynivalenol content of barley, with improvements in nutrient levels. However, the need to reduce the deoxynivalenol content of contaminated barley to less than 1 ppm for swine will necessitate the removal of a significant amount of the grain mass for heavily contaminated samples. PMID:12903987

  5. Air Abrasion

    MedlinePlus

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

  6. Maintaining adequate hydration and nutrition in adult enteral tube feeding.

    PubMed

    Dunn, Sasha

    2015-01-01

    Predicting the nutritional and fluid requirements of enterally-fed patients can be challenging and the practicalities of ensuring adequate delivery must be taken into consideration. Patients who are enterally fed can be more reliant on clinicians, family members and carers to meet their nutrition and hydration needs and identify any deficiencies, excesses or problems with delivery. Estimating a patient's requirements can be challenging due to the limitations of using predictive equations in the clinical setting. Close monitoring by all those involved in the patient's care, as well as regular review by a dietitian, is therefore required to balance the delivery of adequate feed and fluids to meet each patient's individual needs and prevent the complications of malnutrition and dehydration. Increasing the awareness of the signs of malnutrition and dehydration in patients receiving enteral tube feeding among those involved in a patient's care will help any deficiencies to be detected early on and rectified before complications occur. PMID:26087203

  7. 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.

  8. Lying behaviour and IgG-levels of newborn calves after feeding colostrum via tube and nipple bottle feeding.

    PubMed

    Bonk, Stephanie; Nadalin, Audrey; Heuwieser, Wolfgang; Veira, Douglas

    2016-08-01

    Oesophageal tube feeding colostrum is used to ensure sufficient colostrum intake in newborn calves but the impact of tube feeding on animal behaviour is unclear. Therefore the objective of this study was to compare lying behaviour of tube-fed or bottle-fed dairy calves. Calves (n = 37) in 3 groups were offered 3·5 l colostrum 2 h after birth. Calves of the bottle group were fed with a nipple bottle. Calves of the placebo tubing group were tubed for 4 min but no colostrum was given and they were then fed with a nipple bottle. Calves of the tubing group received 3·5 l colostrum via tube feeding. Consumed amount of bottle and placebo tubing calves was recorded. If they refused some of the offered 3·5 l the rest was offered in a second feeding 2 h later. Lying behaviour was measured by data loggers fitted to right hind leg for 3 d. Blood samples were taken 24 h after birth for determination of IgG concentration. The voluntary colostrum intake differed significantly between bottle-fed and placebo tubed calves at first feeding. Considering both colostrum feedings, bottle-fed calves consumed 3·44 ± 0·14 l and placebo tubed calves consumed 3·20 ± 0·38 l colostrum. ImmunoglobulinG intake (255·6 ± 77·5 g IgG), serum IgG concentration 24 h after birth (22·8 ± 6·7 g/l) and total serum protein concentration (6·1 ± 0·6 g/dl) did not differ between groups. None of the calves had a failure of passive transfer. There was no effect of tubing on lying behaviour. PMID:27600963

  9. Knot formation in the feeding jejunostomy tube: a case report and review of the literature.

    PubMed

    Liao, Guo-Shiou; Hsieh, Huan-Fa; Wu, Meng-Hang; Chen, Teng-Wei; Yu, Jyh-Cherng; Liu, Yao-Chi

    2007-02-14

    Jejunostomy feeding tubes provide surgeons with an excellent method for providing nutritional support, but there are several complications associated with a tube jejunostomy, including complications resulting from placement of the tube, mechanical problems related to the location or function and development of focally thickened small-bowel folds. A 76-year old man who presented with multiple medical diseases was admitted to our hospital due to aspiration pneumonia with acute respiratory failure and septic shock. He underwent exploratory laparotomy with feeding jejunostomy using a 14-French nasogastric tube for nutritional support. However, occlusion of the feeding tube was found 30 d after operation, and a rare complication of knot formation in the tube occurred after a new tube was replaced. On the following day, the tube was removed and replaced with a similar tube, which was placed into the jejunum for only 15 cm. The patient's feedings were maintained smoothly for two months. Knot formation in the feeding tube seems to be very rare. To our knowledge, this is the third case in the literature review. Its incidence is probably related to the length of the tube inserted into the lumen. PMID:17352035

  10. The Challenges of Home Enteral Tube Feeding: A Global Perspective

    PubMed Central

    Ojo, Omorogieva

    2015-01-01

    The aim of this review is to provide a global perspective of Home Enteral Tube Feeding (HETF) and to outline some of the challenges of home enteral nutrition (HEN) provisions. It is well established that the number of patients on HETF is on the increase worldwide due to advances in technology, development of percutaneous endoscopic gastrostomy techniques, and the shift in care provisions from acute to community settings. While the significance of home enteral nutrition in meeting the nutritional requirements of patients with poor swallowing reflexes and those with poor nutritional status is not in doubt, differences exist in terms of funding, standards, management approaches and the level of infrastructural development across the world. Strategies for alleviating some of the challenges militating against the effective delivery of HETF including the development of national and international standards, guidelines and policies for HETF, increased awareness and funding by government at all levels were discussed. Others, including development of HEN services, which should create the enabling environment for multidisciplinary team work, clinical audit and research, recruitment and retention of specialist staff, and improvement in patient outcomes have been outlined. However, more research is required to fully establish the cost effectiveness of the HEN service especially in developing countries and to compare the organization of HEN service between developing and developed countries. PMID:25856223

  11. The challenges of home enteral tube feeding: a global perspective.

    PubMed

    Ojo, Omorogieva

    2015-04-01

    The aim of this review is to provide a global perspective of Home Enteral Tube Feeding (HETF) and to outline some of the challenges of home enteral nutrition (HEN) provisions. It is well established that the number of patients on HETF is on the increase worldwide due to advances in technology, development of percutaneous endoscopic gastrostomy techniques, and the shift in care provisions from acute to community settings. While the significance of home enteral nutrition in meeting the nutritional requirements of patients with poor swallowing reflexes and those with poor nutritional status is not in doubt, differences exist in terms of funding, standards, management approaches and the level of infrastructural development across the world. Strategies for alleviating some of the challenges militating against the effective delivery of HETF including the development of national and international standards, guidelines and policies for HETF, increased awareness and funding by government at all levels were discussed. Others, including development of HEN services, which should create the enabling environment for multidisciplinary team work, clinical audit and research, recruitment and retention of specialist staff, and improvement in patient outcomes have been outlined. However, more research is required to fully establish the cost effectiveness of the HEN service especially in developing countries and to compare the organization of HEN service between developing and developed countries. PMID:25856223

  12. 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)

  13. Neonatal enteral feeding tubes as loci for colonisation by members of the Enterobacteriaceae

    PubMed Central

    2009-01-01

    Background The objective of this study was to determine whether neonatal nasogastric enteral feeding tubes are colonised by the opportunistic pathogen Cronobacter spp. (Enterobacter sakazakii) and other Enterobacteriaceae, and whether their presence was influenced by the feeding regime. Methods One hundred and twenty-nine tubes were collected from two neonatal intensive care units (NICU). A questionnaire on feeding regime was completed with each sample. Enterobacteriaceae present in the tubes were identified using conventional and molecular methods, and their antibiograms determined. Results The neonates were fed breast milk (16%), fortified breast milk (28%), ready to feed formula (20%), reconstituted powdered infant formula (PIF, 6%), or a mixture of these (21%). Eight percent of tubes were received from neonates who were 'nil by mouth'. Organisms were isolated from 76% of enteral feeding tubes as a biofilm (up to 107 cfu/tube from neonates fed fortified breast milk and reconstituted PIF) and in the residual lumen liquid (up to 107 Enterobacteriaceae cfu/ml, average volume 250 μl). The most common isolates were Enterobacter cancerogenus (41%), Serratia marcescens (36%), E. hormaechei (33%), Escherichia coli (29%), Klebsiella pneumoniae (25%), Raoultella terrigena (10%), and S. liquefaciens (12%). Other organisms isolated included C. sakazakii (2%),Yersinia enterocolitica (1%),Citrobacter freundii (1%), E. vulneris (1%), Pseudomonas fluorescens (1%), and P. luteola (1%). The enteral feeding tubes were in place between < 6 h (22%) to > 48 h (13%). All the S. marcescens isolates from the enteral feeding tubes were resistant to amoxicillin and co-amoxiclav. Of additional importance was that a quarter of E. hormaechei isolates were resistant to the 3rd generation cephalosporins ceftazidime and cefotaxime. During the period of the study, K. pneumoniae and S. marcescens caused infections in the two NICUs. Conclusion This study shows that neonatal enteral feeding tubes

  14. Utilization of Feeding Tubes in the Management of Feline Chronic Kidney Disease.

    PubMed

    Ross, Sheri

    2016-11-01

    Esophagostomy feeding tubes are useful, and in many cases essential, for the comprehensive management of cats with moderate to advanced chronic kidney disease (CKD). They should be considered a lifelong therapeutic appliance to facilitate the global management of cats with CKD thus providing improved therapeutic efficacy and quality-of-life. Esophagostomy tubes facilitate the maintenance of adequate hydration and increase owner compliance by facilitating the administration of medications. Finally, feeding tubes provide a means to deliver a stage-appropriate dietary prescription for cats with CKD and maintain an adequate nutritional plane in a patient that otherwise would be subject to chronic wasting. PMID:27499006

  15. Bedside placement of small-bowel feeding tube in Intensive Care Unit for enteral nutrition

    PubMed Central

    Gokhale, Antara; Kantoor, Sandeep; Prakash, Sadanandan; Manhas, Yogesh; Chandwani, Juhi; Mahmoud, Ashraf Ezzat

    2016-01-01

    Enteral nutrition is the preferred mode of nutrition in critically ill patients whenever feasible as it has a number of advantages over parenteral feeding. Both gastric and small-bowel feeding can effectively deliver calories. In patients with gastroparesis, small-bowel feeding can help avoid parenteral feeding. We carried out a retrospective observational study to assess the ability to insert the Tiger 2 tube into the small bowel at the bedside in 25 patients who failed to tolerate gastric feeds. The time taken, rate of successful insertion, and ability to feed these patients using a standardized feeding protocol were noted. Success rate of insertion was 78% and feeding could be established. This method reduced the delays and risks associated with transportation and dependence on other specialties. PMID:27390461

  16. Bedside placement of small-bowel feeding tube in Intensive Care Unit for enteral nutrition.

    PubMed

    Gokhale, Antara; Kantoor, Sandeep; Prakash, Sadanandan; Manhas, Yogesh; Chandwani, Juhi; Mahmoud, Ashraf Ezzat

    2016-06-01

    Enteral nutrition is the preferred mode of nutrition in critically ill patients whenever feasible as it has a number of advantages over parenteral feeding. Both gastric and small-bowel feeding can effectively deliver calories. In patients with gastroparesis, small-bowel feeding can help avoid parenteral feeding. We carried out a retrospective observational study to assess the ability to insert the Tiger 2 tube into the small bowel at the bedside in 25 patients who failed to tolerate gastric feeds. The time taken, rate of successful insertion, and ability to feed these patients using a standardized feeding protocol were noted. Success rate of insertion was 78% and feeding could be established. This method reduced the delays and risks associated with transportation and dependence on other specialties. PMID:27390461

  17. 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

  18. 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.

  19. The Influence of Nursing Home Culture on the Use of Feeding Tubes

    PubMed Central

    Lopez, Ruth Palan; Amella, Elaine J.; Strumpf, Neville E.; Teno, Joan M.; Mitchell, Susan L.

    2010-01-01

    Background Nationwide, many nursing home (NH) residents with advanced cognitive impairment are tube fed, despite no demonstrable benefits of this intervention in this population. Studies suggest that organizational features of NHs are associated with this practice, but underlying reasons for these associations are poorly understood. Methods We conducted a focused ethnographic study of 2 NHs in South Carolina, 1 with a high tube-feeding rate (41.8%) in patients with advanced dementia, and 1 with a low rate (10.7%). Data were collected about physical environment, mealtime and decision-making processes, and explicit and implicit values using 80 hours of direct observation, semistructured interviews with 30 key facility personnel, and abstraction of publicly available material describing the facilities. Data were analyzed using qualitative methods. Results Striking variations in organizational culture were identified. The low-use NH had a homelike environment centered on food as an important component of daily life, mealtimes staffed with knowledgeable nursing assistants who valued hand feeding, and advance care planning that included family and palliative care options. In contrast, the high-use NH had an institution like environment, poorly staffed mealtimes, and staff attitudes favoring feeding tubes to avoid aspiration and to meet perceived regulatory compliance. Conclusions The NH culture influences the approach to feeding in advanced cognitive impairment, whether by hand or placement of a feeding tube. Key features of NHs with a low rate of tube-feeding use include a physical environment that promotes the enjoyment of food, administrative support, and empowerment of staff to value hand feeding and shared decision-making processes involving family members. PMID:20065203

  20. [Normalization of hypercholesterolemia in a female stroke patient after switching from enteral tube feeding to oral feeding].

    PubMed

    Takahashi, R; Kanemaru, A; Yamanaka, T; Sakurai, Y; Mochizuki, N; Matsukura, T; Fujitomi, A; Ashikawa, S

    1996-02-01

    A 70-year-old female was admitted to a general hospital in a rural area due to left putamenal cerebral hemorrhage in December 1994. She had right hemiplegia and was totally aphasic. In May 1995, she was moved to Tokyo where her son lives, and she was admitted to Tokyo Metropolitan Geriatric Hospital in order to prepare a home care system. her family's support (serving her favorite dishes) allowed enteral tube feeding to be halted. After one month she could absorb enough energy to maintain her serum albumin level. The total calories ingested orally was comparable to that of enteral feeding but the fat composition was 62% of that of enteral feeding (fat was 19.6% and 31.7% of the total calories in the two diets, respectively). Her cholesterol level decreased from 286 mg/dl to 197 mg/dl. Nutrient-balanced tube feeding is useful, but may disturb lipid metabolism in patients used to having vegetable-rich diets. PMID:8656578

  1. 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

  2. A randomised prospective comparison of percutaneous endoscopic gastrostomy and nasogastric tube feeding after acute dysphagic stroke.

    PubMed Central

    Norton, B.; Homer-Ward, M.; Donnelly, M. T.; Long, R. G.; Holmes, G. K.

    1996-01-01

    OBJECTIVE--To compare percutaneous endoscopic gastrostomy and nasogastric tube feeding after acute dysphagic stroke. DESIGN--Randomised prospective study of inpatients with acute stroke requiring enteral nutrition. SETTING--One university hospital (Nottingham) and one district general hospital (Derby). SUBJECTS--30 patients with persisting dysphagia at 14 days after acute stroke: 16 patients were randomised to gastrostomy tube feeding and 14 to nasogastric tube feeding. MAIN OUTCOME MEASURES--Six week mortality; amount of feed administered; change in nutritional state; treatment failure; and length of hospital stay. RESULTS--Mortality at 6 weeks was significantly lower in the gastrostomy group with two deaths (12%) compared with eight deaths (57%) in the nasogastric group (P < 0.05). All gastrostomy fed patients (16) received the total prescribed feed whereas 10/14 (71%) of nasogastric patients lost at least one day's feed. Nasogastric patients received a significantly (P < 0.001) smaller proportion of their prescribed feed (78%; 95% confidence interval 63% to 94%) compared with the gastrostomy group (100%). Patients fed via a gastrostomy tube showed greater improvement in nutritional state, according to several different criteria at six weeks compared with the nasogastric group. In the gastrostomy group the mean albumin concentration increased from 27.1 g/l (24.5 g/l to 29.7 g/l) to 30.1 g/l (28.3 g/l to 31.9 g/l). In contrast, among the nasogastric group there was a reduction from 31.4 g/l (28.6 g/l to 34.2 g/l) to 22.3 g/l (20.7 g/l to 23.9 g/l) (P < 0.003). In addition, there were fewer treatment failures in the gastrostomy group (0/16 versus 3/14). Six patients from the gastrostomy group were discharged from hospital within six weeks of the procedure compared with none from the nasogastric group (P < 0.05). CONCLUSION--This study indicates that early gastrostomy tube feeding is greatly superior to nasogastric tube feeding and should be the nutritional

  3. Tolerance to enteral tube feeding diets in hypoalbuminemic critically ill, geriatric patients.

    PubMed

    Borlase, B C; Bell, S J; Lewis, E J; Swails, W; Bistrian, B R; Forse, R A; Blackburn, G L

    1992-03-01

    Tolerance of elemental (for example, Peptamen [PEP]) or free amino acid (for example, Vivonex TEN [VIV]) tube feeding diets is controversial, especially in the critically ill patient who is hypoalbuminemic. A prospective, randomized trial was conducted to compare differences between feeding PEP (n = 8) or VIV (n = 8) in critically ill, elderly (average age of 66 years) patients. Diets were administered through nasogastric or postpyloric feeding tubes. Eleven patients had diseases of the gastrointestinal tract; all underwent surgical treatment. Patients were fed each diet at full strength, beginning with 20 to 30 milliliters per hour and advancing by 10 to 20 milliliters every day until goal rate was reached, usually on day 4. Assessment was made for ability to comply with rate of tube feeding ordered, compliance with caloric goal and tolerance (as evidenced by abdominal discomfort and diarrhea). Diarrhea was qualitatively defined as more than three stools per day and then quantitatively as the mean number of stools daily. There were no significant differences between the two groups in terms of compliance with prescribed tube feeding order or caloric goal or the presence of diarrhea and abdominal discomfort. There was a significant difference between the two groups in terms of the actual number of stools per day (PEP equals 1.38 versus VIV equals 2.25, p less than 0.02). Serum albumin concentrations upon initiation of the diets were 2.3 grams per deciliter in both groups. We conclude that tolerance to the two diets were similar because it was possible to feed enterally either PEP or VIV in critically ill, hypoalbuminemic patients (serum albumin concentrations of less than 2.5 grams per deciliter) successfully, irrespective of diet. Although there were more stools in the VIV group, this did not reduce compliance with the goals. PMID:1542832

  4. Bendable Extension For Abrasive-Jet Cleaning

    NASA Technical Reports Server (NTRS)

    Mayer, Walter

    1989-01-01

    Hard-to-reach places cleaned more easily. Extension for abrasive-jet apparatus bent to provide controlled abrasive cleaning of walls in deep cavities or other hard-to-reach places. Designed for controlled removal of penetrant inspection dyes from inside castings, extension tube also used for such general grit-blasting work as removal of scratches.

  5. Ciprofloxacin absorption is impaired in patients given enteral feedings orally and via gastrostomy and jejunostomy tubes.

    PubMed Central

    Healy, D P; Brodbeck, M C; Clendening, C E

    1996-01-01

    Twenty-six hospitalized patients participated in a randomized crossover study to evaluate the effect of enteral feedings on ciprofloxacin absorption when given orally or via gastrostomy or jejunostomy tubes. Patients in the oral group received an intact 500-mg ciprofloxacin tablet alone or ciprofloxacin plus three oral doses of Sustacal (240 ml given 8 h before, with, and 4 h after ciprofloxacin administration). Patients with gastrostomy or jejunostomy tubes received 500 mg of crushed ciprofloxacin in 60 ml water via the feeding tube. After a washout period, the patients received ciprofloxacin with a continuous enteral formula (Jevity) given at 60 to 90 ml/h beginning 6 h before drug administration and continuing for 10 h. Serial blood samples were analyzed for ciprofloxacin concentration by high-performance liquid chromatography. The maximum ciprofloxacin concentrations in serum for ciprofloxacin given and for ciprofloxacin plus enteral feeding for the oral, gastrostomy, and jejunostomy groups were (mean +/- standard deviation) 2.59 +/- 1.24 versus 1.43 +/- 0.61 micrograms/ml (P < 0.05), 3.68 +/- 1.36 versus 2.27 +/- 0.67 micrograms/ml (P < 0.05), and 3.78 +/- 1.87 versus 1.45 +/- 0.48 micrograms/ml (P < 0.05), respectively. Corresponding values for area under the concentration-time curve were 13.4 +/- 8.32 versus 9.44 +/- 4.74 micrograms/h/ml (P < 0.05) 15.9 +/- 6.62 versus 7.44 +/- 3.16 (micrograms/h/ml (P < 0.05), and 18.1 +/- 9.37 versus 5.82 +/- 2.63 micrograms.h/ml (P < 0.05). We conclude that enteral feedings given orally or via gastrostomy or jejunostomy tubes resulted in a 27 to 67% reduction in the mean bioavailability of ciprofloxacin in hospitalized patients. The decreased absorption may be clinically important, especially when the enteral feeding is coadministered with ciprofloxacin by the oral and jejunostomy tube routes. Reductions in maximum levels of ciprofloxacin in serum as a result of feedings given via a gastrostomy tube are similar to those

  6. The effect of system design on bacterial contamination of enteral tube feeds.

    PubMed

    McKinlay, J; Wildgoose, A; Wood, W; Gould, I M; Anderton, A

    2001-02-01

    The effect of recent changes in system design on the levels and incidence of bacterial contamination in enteral tube feeds was examined by comparing two different systems. Adult patients who had been identified as requiring enteral tube feeding were allocated to receive sterile, whole protein enteral feed from either 2 x 1000 mL triple foil laminated pouches (Nutrison Standard, Nutrison Pack, Nutricia Ltd, UK) attached to a Flocare 800 pack giving set or from 2 x 1000 mL rigid plastic bottles (Osmolite, Ross Ready-to-Hang, Abbott Laboratories, UK) connected to a Patrol Pump set. Samples of feed from the nutrient containers were sent for microbiological analysis each time the container was changed (12 and 24 h) and samples from the distal ends of giving sets after 24 h.Bacterial contamination was found in a significantly lower number of Nutrison Packs (14/120; 12%) as compared with Ross Ready-to-Hang containers (25/120; 21%) (Fisher's exact test, 1 tailed test, P > or = 0.05). However, both the level and frequency of contamination of the feed samples collected from the distal ends of the giving sets of both types of system were similar to each other but higher than those from the nutrient containers (57/120 contaminated giving sets as compared with 39/240 nutrient containers; P > or = 0.00001). On 32/120 patient days only the giving set samples were contaminated. The results highlight the important role that improvements in system design, such as the use of recessed spikes on giving sets have in reducing the risk of bacterial contamination of enteral tube feeds introduced due to faulty handling procedures, and further implicate retrograde spread of the patients' own flora as a source of contamination in the giving set. PMID:11170778

  7. 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.

  8. Nutritional and behavioural aspects of nasogastric tube feeding in infants receiving chronic peritoneal dialysis.

    PubMed

    Warady, B A; Kriley, M; Belden, B; Hellerstein, S; Alan, U

    1990-01-01

    Eight infants initiated chronic peritoneal dialysis and received nasogastric tube feedings during their first month of life. In each case, the nasogastric tube feedings were initiated because of poor oral intake and the desire to avert the development of an aversive feeding interaction between parent and child. The nutritional regimen was designed to allow normal or catch up weight gain appropriate for height age. The caloric and protein intake of the infants averaged 98.5 +/- 10.2 kcal/kg/day and 2.7 gm/kg/day, respectively, during the first year of life. Between 25% and 100% of the formula intake was provided by the nasogastric route. Group standard deviation score for height was -1.74 +/- 0.7 at one year. Five of the infants received behavioral therapy because of persistent food refusal. Therapy consisted of reinforcing prompted food acceptance and ignoring food refusal. This approach was conducted by a multidisciplinary team and successfully converted the non-oral feeder to a total oral feeding regimen in each case. PMID:1982822

  9. A descriptive study of nasogastric tube feeding among geriatric inpatients in Malaysia: utilization, complications, and caregiver opinions.

    PubMed

    Nordin, Nordiana; Kamaruzzaman, Shahrul Bahyah; Chin, Ai-Vyrn; Poi, Philip J H; Tan, Maw Pin

    2015-01-01

    The strong emphasis on feeding in Asian cultures may influence decisions for nasogastric (NG) tube feeding in geriatric inpatients. We evaluated the utility, complications, and opinions of caregivers toward NG tube feeding in an acute geriatric ward in a teaching hospital in Kuala Lumpur. Consecutive patients aged 65 years and older receiving NG tube feeding were included. Sociodemographic, clinical, and laboratory indices were recorded. Opinion on NG tube feeding were evaluated through face-to-face interviews with caregivers, recruited through convenience sampling. Of 432 patients admitted, 96 (22%), age ± standard deviation = 80.8 ± 7.4 years, received NG tube feeding. The complication and mortality rates were 69% and 38%, respectively. Diabetes (odds ratio [95% confidence interval] = 3.34 [1.07, 10.44], aspiration pneumonia (8.15 [2.43, 27.24]), impaired consciousness (3.13 [1.05, 9.36]), and albumin ≤26 g/dl (4.43 [1.46, 13.44]) were independent predictors of mortality. Other relatives were more likely than spouses (23.5 [3.59, 154.2]) and caregivers with tertiary education more likely than those with no formal education ( 18 [1.23, 262.7]) to agree to NG feeding. Sixty-four percent of caregivers felt NG tube feeding was appropriate at the end of life, mostly due to the fear of starvation. NG tube feeding is widely used in our setting, despite high complication and mortality rates, with likely influences from cultural emphasis on feeding. PMID:25803603

  10. The evolving role of post-ligament of Trietz nasojejunal feeding in enteral nutrition and the need for improved feeding tube design and placement methods.

    PubMed

    Silk, D B A

    2011-05-01

    Nutrition support is an important link in the chain of therapy for intensive care unit patients. The early institution of nutrition support significantly reduces the incidence of septic complications, reduces mortality, and shortens hospital stay. Unfortunately, impaired gastrointestinal function, particularly gastric atony, restricts the use of nasogastric enteral tube feeding, and the use of this route of administration in these patients can lead to regurgitation, aspiration, and the development of pneumonia. Postpyloric enteral feeding was heralded as a means of overcoming many of these problems. Overall, the results of controlled studies do not support a role of postpyloric duodenal feeding in reducing the incidence of aspiration pneumonia. As a consequence, post-ligament of Treitz nasojejunal enteral feeding is proposed as the technique of choice in these patients. Feeding tube design must incorporate a gastric aspiration port to overcome problems of gastroesophageal acid reflux, duodenogastric bile reflux, and increased gastric acid secretion, problems that occur during "downstream" jejunal feeding. Tube placement technique will need to be refined and patients will need to receive a predigested enteral diet. In postoperative surgical patients in the intensive care unit, there is also a need for a newly designed dual-purpose nasogastric tube capable initially of providing a means of undertaking gastric aspiration and decompression and subsequently a means of initiating nasogastric enteral feeding. PMID:21393640

  11. 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. PMID:26948408

  12. Errors of oral medication administration in a patient with enteral feeding tube.

    PubMed

    Emami, Shahram; Hamishehkar, Hadi; Mahmoodpoor, Ata; Mashayekhi, Simin; Asgharian, Parina

    2012-07-01

    Enteral feeding tube is employed for feeding of critically ill patients who are unable to eat. In the cases of oral medication administration to enterally fed patients, some potential errors could happen. We report a 53-year-old man who was admitted to intensive care unit (ICU) of a teaching hospital due to the post-CPR hypoxemic encephalopathy. The patient was intubated and underwent mechanical ventilation. A nasogastric (NG) tube was used as the enteral route for nutrition and administration of oral medications. Oral medications were crushed then dissolved in tap water and were given to the patient through NG tube. In present article we report several medication errors occurred during enterally drug administration, including errors in dosage form selection, methods of oral medication administration and drug interactions and incompatibility with nutrition formula. These errors could reduce the effects of drugs and lead to unsuccessful treatment of patient and also could increase the risk of potential adverse drug reactions. Potential leading causes of these errors include lack of drug knowledge among physicians, inadequate training of nurses and lack of pharmacists participation in medical settings. PMID:24991587

  13. Glutamine-supplemented tube feedings versus total parenteral nutrition in children receiving intensive chemotherapy.

    PubMed

    Ford, C; Whitlock, J A; Pietsch, J B

    1997-04-01

    Although enteral nutrition is generally advocated in the care of children with cancer, those patients receiving intensive chemotherapy alone or in combination with bone marrow transplantation often require total parenteral nutrition (TPN). Two patients are presented illustrating some differences between enteral and parenteral feedings in children receiving intensive chemotherapy. Nasogastric glutamine-supplemented tube feedings were well tolerated both in the hospital and at home. The cost of care for the enterally supported child was less than one third of the TPN-supported child. Although TPN appears to be beneficial in some patients with cancer, it is expensive and is associated with several significant disadvantages. Among these are an increased incidence of both gram-positive and gram-negative infections and an increased incidence of gastrointestinal symptoms. Enteral nutrition is less costly than TPN and maintains the structural and functional integrity of the intestinal mucosa. The addition of certain substrates such as glutamine, arginine and omega-3 fatty acids may improve the body's immune response as well. We hypothesize that early glutamine supplemented tube feedings in children receiving intensive chemotherapy alone or in combination with bone marrow transplantation will result in improved nutrition with fewer infections and lower cost than TPN-supplemented patients. In addition, a shorter hospital stay and improved quality of life are anticipated. PMID:9144976

  14. The measurement of abrasive particles velocities in the process of abrasive water jet generation

    NASA Astrophysics Data System (ADS)

    Zeleňák, Michal; Foldyna, Josef; Říha, Zdeněk

    2014-08-01

    An optimization of the design of the abrasive cutting head using the numerical simulation requires gathering as much information about processes occurring in the cutting head as possible. Detailed knowledge of velocities of abrasive particles in the process of abrasive water jet generation is vital for the verification of the numerical model. A method of measurement of abrasive particles at the exit of focusing tube using the FPIV technique was proposed and preliminary tests are described in the paper. Results of analysis of measured velocity fields are presented in the paper.

  15. Attachment of and Biofilm Formation by Enterobacter sakazakii on Stainless Steel and Enteral Feeding Tubes

    PubMed Central

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

    2006-01-01

    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°C were examined for the extent to which they attach to these materials. Higher populations attached at 25°C than at 12°C. Stainless steel coupons and enteral feeding tubes were immersed for 24 h at 4°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/cm2, respectively, before they were immersed in TSB, IFB, or LJB, followed by incubation at 12 or 25°C for up to 10 days. Biofilms were not produced at 12°C. The number of cells of test strains increased by 1.42 to 1.67 log CFU/cm2 and 1.16 to 1.31 log CFU/cm2 in biofilms formed on stainless steel and feeding tubes, respectively, immersed in IFB at 25°C; biofilms were not formed on TSB and LJB at 25°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. PMID:16957203

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

    PubMed

    Rayyan, Maissa; Rommel, Nathalie; Allegaert, Karel

    2015-08-01

    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

  17. Comparative study of two systems of delivering supplemental protein with standardized tube feedings.

    PubMed

    Luther, Heidi; Barco, Kathy; Chima, Cinda; Yowler, Charles J

    2003-01-01

    Burn patients often require protein supplementation for their nutritional support. Although these are often added to a commercial formula, published standards recommend a 4-hr hang time for manipulated open-system formulas in comparison with 24 hr for unopened closed systems. We hypothesized that use of standard closed-system formulas with the addition of protein flushes via the feeding tube twice daily would reduce nursing time and increase satisfaction. A pilot study included a time study comparing the two methods and a nursing satisfaction questionnaire. Management of an open system consistent with national standards took almost twice as much nursing time daily as the closed system with supplemental protein flushes (36.6 +/- 17.1 min vs 18.6 +/- 3.6 min; P =.051). Sixteen of 17 nurses preferred the closed system with protein flush. The results of this study were used to support expansion of the protocol change throughout the hospital. PMID:12792240

  18. 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; Worswick, Michael; Mayer, Robert

    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 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.

  19. 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.

  20. A Matter of Taste? Quality of Life in Day-to-Day Living with ALS and a Feeding Tube.

    PubMed

    Pols, Jeannette; Limburg, Sarah

    2016-09-01

    Although people often refer to quality of life and there is a respectable research tradition to establish it, the meaning of the term is unclear. In this article we qualitatively study an intervention of which the quantitative effects are documented as indecisive. We do this in order to learn more about what the meaning of the term quality of life means when it is studied in daily life. With the help of these findings we reflect on the intricacies of objectifying and measuring quality of life using quantitative research designs. Our case is the feeding tube for patients suffering from ALS, a severe motor neuron disease that rapidly and progressively incapacitates patients. We studied how these patients, who lived in the Netherlands, anticipated and lived with a feeding tube in the course of their physical deterioration. Our analysis shows that the quality of life related to the feeding tube has to be understood as a process rather than as an outcome. The feeding tube becomes a different thing as patients move through the various phases of their illness, due to changes in their condition, living circumstances, and concerns and values. There are very different appreciations of the way the feeding tube changes the body's appearance and feel. Some patients refuse it because they feel it disfigures their body, whereas others are indifferent to its appearance. Our conclusion is that these differences are difficult to grasp with a quantitative study designs because 'matters of taste' and values are not distributed in a population in the same ways as physiological responses to medication. Effect studies assume physiological responses to be more or less the same for everyone, with only gradual differences. Our analysis of quality in daily life, however, shows that what a treatment comes to be and how it is valued shows shows generalities for subgroups rather than populations. PMID:26547696

  1. [Usefulness of endoscopically guided nasogastric-jejunal feeding tube placement in a case of aspiration pneumonia due to postgastrectomy].

    PubMed

    Tamura, Kosei; Totsuka, Osamu; Tamura, Jun'ichi

    2015-01-01

    A 79-year-old man with a history of gastrectomy with Billroth II reconstruction 27 years previously was admitted to our hospital due to recurrent pneumonia. Because he had dysphagia and had frequently developed pneumonia over the course of a year, enteral nutrition via nasogastric tube was initiated approximately six months before admission. The clinical and computed tomography findings showed that the cause of pneumonia was aspiration of tube feeding nutrients due to gastroesophageal reflux. To prevent gastroesophageal reflux, he was continuously kept in a 30-degree or greater reclining position. However, gastroesophageal reflux was seen at an injection rate of 50 ml/h or greater. After we inserted a nasogastric-jejunal feeding tube guided by endoscopy, gastroesophageal reflux, dumping syndrome and diarrhea were not seen up to an injection rate of 300 ml/h. Endoscopically guided nasogastric-jejunal feeding tube placement is a simple method and may be useful for patients with aspiration pneumonia due to postgastrectomy. Moreover, long-term postgastrectomy patients appear to tolerate the postopyloric injection of enteral nutrition. Because the number of elderly patients who have dysphagia with postgastrectomy is increasing, these findings provide a basis for treatment in elderly medical settings. PMID:26700781

  2. A very feasible alternative in patients with feeding difficulties from gastrostomy: Jejunal tube advanced through the gastrostomy

    PubMed Central

    Karabulut, Ramazan; Turkyilmaz, Zafer; Sonmez, Kaan; Oktar, Suna Ozhan; Kaya, Cem; Kokurcan, Atilla; Oncu, Fatih; Basaklar, Abdullah Can

    2015-01-01

    Background: Our aim is to share our experiences regarding patients who cannot be fed effectively through the gastrostomy tube, but were inserted feeding jejunostomy through the gastrostomy orifice using scopic fluoroscopic techniques utilised by the interventional radiology. Patients and Methods: Between January 2010 and May 2013 the patients that were inserted jejunostomy tube through the gastrostomy orifice using fluoroscopic techniques were retrospectively analysed. Data including primary indication for gastrostomy, sex, concomitant disease and the requirement for gastroesophageal reflux disease (GERD) were all recorded. Results: There were five patients with these criteria. They all received either medical or surgical GERD therapy; nevertheless enteral feeding failed to reach an effective level, they all had vomiting and did not gain any weight. Following conversion, all the patients gained minimum 2 kg in 2-5 months; all the patients tolerated enteral feeding and were discharged in the early period. There were neither procedure related complications such as perforation, bleeding nor sedation related complications. Procedure took no more than 30 min as a whole. There was no need for surgical intervention. However in one patient re-intervention was required due to accidental removal of the catheter. Conclusions: In case of feeding difficulties following the gastrostomy; instead of an invasive surgical intervention; physicians should consider jejunal feeding that is advanced through the gastrostomy, which does not require any anaesthesia. PMID:26168749

  3. Abrasive drill for resilient materials

    NASA Technical Reports Server (NTRS)

    Koch, A. J.

    1981-01-01

    Resilient materials normally present problem in obtaining accurate and uniform hole size and position. Tool is fabricated from stiff metal rod such as tungsten or carbon steel that has diameter slightly smaller than required hole. Piercing/centering point is ground on one end of rod. Rod is then plasma-sprayed (flame-sprayed) with suitable hard abrasive coating. High-speed, slow-feed operation of tool is necessary for accurate holes, and this can be done with drill press, hard drill, or similar machines.

  4. Enteral Feeding Tubes in Patients Undergoing Definitive Chemoradiation Therapy for Head-and-Neck Cancer: A Critical Review

    SciTech Connect

    Koyfman, Shlomo A.; Adelstein, David J.

    2012-11-01

    Definitive chemoradiation therapy has evolved as the preferred organ preservation strategy in the treatment of locally advanced head-and-neck cancer (LA-HNC). Dry mouth and dysphagia are among the most common and most debilitating treatment-related toxicities that frequently necessitate the placement of enteral feeding tubes (FT) in these patients to help them meet their nutritional requirements. The use of either a percutaneous endoscopic gastrostomy tube or a nasogastric tube, the choice of using a prophylactic vs a reactive approach, and the effects of FTs on weight loss, hospitalization, quality of life, and long-term functional outcomes are areas of continued controversy. Considerable variations in practice patterns exist in the United States and abroad. This critical review synthesizes the current data for the use of enteral FTs in this patient population and clarifies the relative advantages of different types of FTs and the timing of their use. Recent developments in the biologic understanding and treatment approaches for LA-HNC appear to be favorably impacting the frequency and severity of treatment-related dysphagia and may reduce the need for enteral tube feeding in the future.

  5. [Comparative biological value of the proteins comprising the products for the tube and regular feeding of patients with mandibular fractures].

    PubMed

    Kholodov, S V; Vitollo, A S; Kalamkarova, O M; Rud'ko, V F; Vysotskiĭ, V G

    1988-01-01

    A comparative clinical evaluation was made of the biological effectiveness of protein components in the composition of three types of diet for patients with fractures of the mandible who had received "Ensure" (USA), a product for complete tube feeding; an experimental sample developed at the Institute of Nutrition, Academy of Medical Sciences of the USSR; and a routine clinical diet. The biological effectiveness of the proteins was estimated by some anthropometric and biochemical parameters as well as on the basis of nitrogenous metabolism in the patients. It has been established that the protein content in the routine clinical diets does not meet the high requirements in amino acids of patients with fracture of the mandible. In this respect the products for tube and dietotherapy have proved to be effective and completely provide the need of such patients in essential amino acids that has been evidenced by the results of the investigations conducted. PMID:3146160

  6. 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. PMID:23966117

  7. Management of an unusual case of iatrogenic parotid sialocele using an infant feeding tube: a novel approach.

    PubMed

    Kulkarni, Ambadas; Chandrasala, Soumithran; Nimbeni, Basavaraj S; Singh, Surendar Pal; Golai, Shruti

    2014-01-01

    Injuries to the parotid duct and parenchyma resulting in swelling in the cheek region commonly present in maxillofacial practice. Sialocele is a discrete collection of saliva in a subcutaneous cavity that can be iatrogenic, idiopathic or the result of post-traumatic injuries to the duct or parenchyma, presenting as a salivary pseudocyst or retention cyst. We present an unusual case of parotid sialocele following surgery for sialolithiasis which presented with progressive painless swelling in the preauricular region of 9 months duration. Treatment included surgical exploration under local anaesthesia and draining the cavity by keeping the opening patent using an infant feeding tube. PMID:25331148

  8. 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. PMID:16933653

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

    SciTech Connect

    Bhaskar Kura; Kalpalatha Kambham; Sivaramakrishnan Sangameswaran; Sandhya Potana

    2006-08-15

    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. 40 refs., 5 figs., 2 tabs.

  10. 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

  11. Synthesis CNTs Particle Based Abrasive Media for Abrasive Flow Machining Process

    NASA Astrophysics Data System (ADS)

    Kumar, Sonu; Murtaza, Q.; Walia, R. S.; Dhull, S.; Tyagi, P. K.

    2016-02-01

    Abrasive flow machining (AFM) is a modem fine finishing process used for intricate and internal finishing of components or parts. It is based on flowing of viscoelastic abrasive media over the surface to be fine finished. The abrasive media is the important parameter in the AFM process because of its ability to accurately abrade the predefined area along it flow path. In this study, an attempt is made to develop a new abrasive, alumina with Carbon non tubes (CNTs) in viscoelastic medium. CNT s in house produced through chemical vapour deposition technique and characterize through TEM. Performance evaluation of the new abrasive media is carried out by increasing content of CNT s with fixed extrusion pressure, viscosity of media and media flow rate as process parameters and surface finish improvement and material removal as process responses in AFM setup. Significantly improvement has been observed in material removal and maximum improvement of 100% has been observed in the surface finish on the inner cylindrical surface of the cast iron work piece.

  12. 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.

  13. 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

  14. A comparative study on the tubes and feeding behaviour of eight species of corophioid Amphipoda and their bearing on phylogenetic relationships within the Corophioidea

    PubMed Central

    Dixon, I. M. T.; Moore, P. G.

    1997-01-01

    Observations are presented on mouthpart functional morphology, and on feeding, grooming and defaecatory behaviour of eight species of corophioid Amphipoda, viz. Corophium bonnellii, Lembos websteri, Aora gracilis, A. spinicornis, Gammaropsis nitida, Ericthonius punctatus, Jassa falcata and J. marmorata. These data are considered in relation to tube structure and amphipod posture in relation to the tube. All these species occupy double-ended cylindreical tubes made from 'amphipod silk' secreted by the third and fourth preraeopods, incorporating sediment and other debris to varying degrees. Uniquely among this set of species, however, E. punctatus has a tube that is architecturally distinct. It tapers along its length and has a distinctive oblique main entrance at its widest end. This end is used preferentially. The other species studied use either opening with equal facility. Such a feature is adaptive in facilitating deployment of the antennae and shielding the head of E. punctatus. Two groupings of species are propose: group A which feed inside their tube using pleopod-induced through-tube currents, and group B which feed outside or at the entrance to their tube using external water currents. Group A includes C. bonnellii, L. websteri and the Aora species. Group B includes E. punctatus and the Jassa species. Gammaropsis nitida exhibits traits from both groups, adding weight to its perceived status as a genus representative of the stem corophioid. The ischyrocerid habit of externalizing food-gathering may be regarded as the first step along an evolutionary line leading to the rod-building podocerid types and ultimately towards the caprellids. All species examined show a degree of flexibility in their feeding habits which helps to explain the success of this taxon, which has radiated into a great diversity of aquatic biotopes.

  15. Abrasion resistant heat pipe

    DOEpatents

    Ernst, Donald M.

    1984-10-23

    A specially constructed heat pipe 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.

  16. 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.

  17. 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…

  18. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube...

  19. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube...

  20. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube...

  1. 21 CFR 876.5980 - Gastrointestinal tube and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5980 Gastrointestinal... intubation, feeding tube, gastroenterostomy tube, Levine tube, nasogastric tube, single lumen tube...

  2. Head and neck cancer patients’ perceptions of quality of life and how it is affected by the disease and enteral tube feeding during treatment

    PubMed Central

    Sundberg, Kay; Laurell, Göran; Langius-Eklöf, Ann

    2015-01-01

    Aim. To explore individual quality of life in patients with head and neck cancer from diagnosis up to 3 months after termination of radiotherapy. Research questions: 1) Which areas in life are important to quality of life, and which are influenced by the disease and by having oral or enteral nutrition; and 2) Which areas in life are influenced by having a nasogastric feeding tube (NGT) or a percutaneous endoscopic gastrostomy (PEG) tube? Material and methods. Data were collected in 36 patients. Semi-structured interviews were conducted using an extended version of the Schedule for the Evaluation of Individual Quality of Life (SEIQoL) and analysed with content analysis. Results. Negative and positive experiences of quality of life in general were about relation to family, own health, and leisure activities. Negative impacts on physical, psychological, existential and social problems, but also positive experiences are described by the patients related to the disease. More than half expressed eating-related problems. Enteral nutrition entailed negative and positive experiences, and no greater variations were described by the patients with NGT or PEG tube. Overall, there were interindividual variations. Conclusions. The patients’ perception of general or disease-related quality of life was not affected by whether they had enteral nutrition or not. From the patients’ perspective neither of the two feeding tubes (NGT or PEG) was clearly in favour. We suggest that more studies are needed on how the choice of enteral feeding tube can be evidence-based, and incorporating the patients’ perspective. PMID:26482657

  3. Abrasion protection in process piping

    SciTech Connect

    Accetta, J.

    1996-07-01

    Process piping often is subjected to failure from abrasion or a combination of abrasion and corrosion. Abrasion is a complex phenomenon, with many factors involved to varying degrees. Hard, mineral based alumina ceramic and basalt materials are used to provide protection against abrasion in many piping systems. Successful life extension examples are presented from many different industries. Lined piping components require special attention with regard to operating conditions as well as design and engineering considerations. Economic justification involves direct cost comparisons and avoided costs.

  4. Abrasion resistant composition

    DOEpatents

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

    2014-05-13

    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 the metal matrix.

  5. Unusual complication of multiple splenic abscesses arising from a feeding jejunostomy tube subsequent to total gastrectomy: A case report and literature review

    PubMed Central

    AN, SHUCHANG; LI, BING; CUI, RONG; YAN, FENG; YANG, GUOSHAN; ZHAO, LI; ZHANG, ZHENYA; WANG, RUIQIN

    2015-01-01

    Splenic abscess is a rare clinical entity. The present study reports a case of a patient that suffered from splenic abscess secondary to septicemia resulting from Klebsiella pneumoniae infection following the removal of the feeding jejunostomy tube that was utilized subsequent to the patient undergoing total gastrectomy as part of the treatment regimen for gastric adenocarcinoma. The early clinical presentation was nonspecific and multiple splenic abscesses were subsequently identified. To reduce the risks of an additional surgical procedure in this particular patient, laparoscopic assisted splenotomy and catheter drainage were performed. Due to the severe complications that occurred in the present patient, no adjuvant chemotherapy was administered. Therefore, the unusual complication of splenic abscess subsequent to total gastrectomy should be noted, and the routine feeding jejunostomy tube placement at the time of total gastrectomy should be discussed and re-assessed. PMID:26137078

  6. Gastrostomy feeding tube - bolus

    MedlinePlus

    ... or MIC-KEY, measuring cup with spout, room temperature food, water, rubber band, clamp, and safety pin). Check that your formula or food is warm or room temperature by putting a few droplets on your wrist. ...

  7. Jejunostomy feeding tube

    MedlinePlus

    ... soapy water and a washcloth Dry, clean towel Plastic bag Ointment or hydrogen peroxide (if your doctor recommends) ... bandages on the skin. Place them in the plastic bag, and throw them away. Check the skin for ...

  8. Abrasion-resistant antireflective coating for polycarbonate

    NASA Technical Reports Server (NTRS)

    Wydeven, T. J.

    1978-01-01

    Following plasma-polymerization technique, treatment in oxygen glow discharge further enhances abrasion resistance and transmission. Improvement in abrasion resistance was shown by measuring percentage of haze resulting from abrasion. Coating samples were analyzed for abrasion using standard fresh rubber eraser. Other tests included spectra measurements and elemental analysis with spectrometers and spectrophotometers.

  9. Abrasives in snuff?

    PubMed

    Dahl, B L; Stølen, S O; Oilo, G

    1989-08-01

    The purpose of this study was to determine and calculate the inorganic contents of four brands of snuff. Visual inspection of wet snuff showed fairly large, yellow crystal-like particles. Scanning electron microscopy and X-ray dispersive (EDX) analyses were used to study both wet snuff and ashes of snuff, whereas light emission spectrography was used to determine elements in the ashes. The crystal-like particles did not dissolve in distilled water or in ethanol heated to 60 degrees C. EDX analyses showed that most elements remained in the particles after washing. The total weight percentage of inorganic material in snuff was calculated after burning dried snuff until constant weight was obtained. The ashes of snuff did not contain any crystal-like particles but consisted of a small-grained amorphous mass. The following elements were detected: Ag, Al, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, P, Pb, Si, Sr, Ti, Va, and Zr. Other elements such as rare earths were not searched for. The weight percentage of inorganic elements ranged between 12.35 +/- 0.69 and 20.95 +/- 0.81. Provided snuff is used in the same manner as chewing tobacco, and some people admit to doing so, there is a risk that its relatively high contents of inorganic material and heavily soluble salts may be conducive to excessive abrasion of teeth and restorations. PMID:2782061

  10. Innovative decontamination technology by abrasion in vibratory vessels

    SciTech Connect

    Fabbri, Silvio; Ilarri, Sergio

    2007-07-01

    Available in abstract form only. Full text of publication follows: The possibility of using conventional vibratory vessel technology as a decontamination technique is the motivation for the development of this project. The objective is to explore the feasibility of applying the vibratory vessel technology for decontamination of radioactively-contaminated materials such as pipes and metal structures. The research and development of this technology was granted by the U.S. Department of Energy (DOE). Abrasion processes in vibratory vessels are widely used in the manufacture of metals, ceramics, and plastics. Samples to be treated, solid abrasive media and liquid media are set up into a vessel. Erosion results from the repeated impact of the abrasive particles on the surface of the body being treated. A liquid media, generally detergents or surfactants aid the abrasive action. The amount of material removed increases with the time of treatment. The design and construction of the machine were provided by Vibro, Argentina private company. Tests with radioactively-contaminated aluminum tubes and a stainless steel bar, were performed at laboratory level. Tests showed that it is possible to clean both the external and the internal surface of contaminated tubes. Results show a decontamination factor around 10 after the first 30 minutes of the cleaning time. (authors)

  11. TRAC PF1/MOD1 calculations and data comparisons for mist feed and bleed and steam generator tube rupture experiments

    SciTech Connect

    Siebe, D.A.; Boyack, B.E.; Steiner, J.L.

    1988-01-01

    Los Alamos National Laboratory is a participant in the Integral System Test (IST) program initiated in June 1983 for the purpose of providing integral system test data on specific issues/phenomena relevant to post-small-break loss-of-coolant accidents, loss of feedwater and other transients in Babcock and Wilcox (BandW) plant designs. The Multi-Loop Integral System Test (MIST) facility is the largest single component in the IST program. MIST is a 2 /times/ 4 (two hot legs and steam generators (SGs), four cold legs and reactor coolant pumps) representation of lowered-loop reactor system of the BandW design. It is a full-height, full-pressure facility with 1/817 power and volume scaling. Two other integral experimental facilities are included in the IST program: test loops at the University of Maryland, College Park, and at SRI International (SRI-2). The objective of the IST tests is to generate high-quality experimental data to be used for assessing thermal-hydraulic safety computer codes. Efforts are under way at Los Alamos to assess TRAC-PF1/MOD1 against data from each of the IST facilities. Calculations and data comparisons for TRAC-PF1/MOD1 assessment are presented for two transients run in the MIST facility. These are MIST Test 330302, a feed and bleed test with delayed high-pressure injection; and Test 3404AA, an SG tube-rupture test with the affected SG isolated. Only MIST assessment results are presented in this paper. The TRAC-PF1/MOD1 calculations completed to date for MIST tests are in reasonable agreement with the data from these tests. Reasonable agreement is defined as meaning that major trends are predicted correctly, although TRAC values are frequently outside the range of data uncertainty. We believe that correct conclusions will be reached if the code is used in similar applications despite minor code/model deficiencies. 7 refs., 5 figs., 2 tabs.

  12. 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.

  13. Abrasion of heavy-duty coated steel pipes by sediment transport

    SciTech Connect

    Kariyazono, Yoshihisa; Miyajima, Yoshihiro; Sato, Koichi; Yamashita, Toshihiko, Yamashita; Saeki, Hiroshi

    1994-12-31

    Heavy-duty coatings are standard treatment for steel pipe piles in coastal zones to prevent corrosion. Large amounts of sand sometimes drift around piles by the action of waves. Coatings undergo abrasion by collision of sand particles. Authors carried out experiments by a large scale U-shaped tube which generated a strong oscillatory flow with sand drift and numerical analysis of collision of the particles. Authors found out the abrasion rate of pile is nearly proportional to the collision energy of the particles. Abrasion rate of polyethylene and elastic polyurethane coatings were lower than those of other materials.

  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. PMID:26395117

  15. Abrasion of restorative materials by toothaste.

    PubMed

    Heath, J R; Wilson, H J

    1976-04-01

    The procedure developed in this investigation is suitable for determining the abrasion resistance of restorative materials to toothbrush/dentifrice abrasion. Ideally, a restoration should have an abrasion resistance similar to that of enamel. Of the materials tested, gold was the only one that wore slightly less than enamel, whilst amalgam wore almost twice as quickly. The silicate material and composites (excluding TD.71) wear away 2-4 times faster than enamel. TD.71 and especially the unfilled resin exhibited very high rates of abrasion. After prolonged toothbrush/dentifrice abrasion, the surfaces of gold and amalgam were considerably smoother than those of the silicate and composite materials. PMID:1066445

  16. Abrasive swivel assembly and method

    DOEpatents

    Hashish, Mohamed; Marvin, Mark

    1990-01-01

    An abrasive swivel assembly for providing a rotating, particle-laden fluid stream and, ultimately, a rotating particle-laden fluid jet is disclosed herein. This assembly includes a tubular arrangement for providing a particle-free stream of fluid, a swivel assembly for rotating a section of the tubular arrangement, and a tubular end section for introducing solid particles into the particle-free fluid stream at a point along the rotating tubular section, whereby to produce a particle-laden fluid stream. This last-mentioned stream can then be used in combination with a cooperating nozzle arrangement for providing a rotating particle-laden fluid jet. In an actual working embodiment, the fluid stream is of sufficiently high pressure so that the abrasive jet can be used as a cutting jet.

  17. Abrasive swivel assembly and method

    DOEpatents

    Hashish, Mohamed; Marvin, Mark

    1989-01-01

    An abrasive swivel assembly for providing a rotating, particle-laden fluid stream and, ultimately, a rotating particle-laden fluid jet is disclosed herein. This assembly includes a tubular arrangement for providing a particle-free stream of fluid, means for rotating a section of the tubular arrangement, and means for introducing solid particles into the particle-free fluid stream at a point along the rotating tubular section, whereby to produce a particle-laden fluid stream. This last-mentioned stream can then be used in combination with a cooperating nozzle arrangement for providing a rotating particle-laden fluid jet. In an actual working embodiment, the fluid stream is of sufficiently high pressure so that the abrasive jet can be used as a cutting jet.

  18. Abrasion-resistant coatings for plastic surfaces

    NASA Technical Reports Server (NTRS)

    Wydeven, T.; Hollahan, J. R.

    1976-01-01

    Optically clear composition of organosilicon compounds insulates plastic surfaces and protects them from abrasion. Plasma polymerization process produces superior uniformity and clarity than previous coating techniques.

  19. 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 current 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.

  20. 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.

  1. 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.

  2. 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.

  3. Corneal abrasions associated with pepper spray exposure.

    PubMed

    Brown, L; Takeuchi, D; Challoner, K

    2000-05-01

    Pepper spray containing oleoresin capsicum is used by law enforcement and the public as a form of nonlethal deterrent. Stimulated by the identification of a case of a corneal abrasion associated with pepper spray exposure, a descriptive retrospective review of a physician-maintained log of patients presenting to a jail ward emergency area over a 3-year period was performed. The objective was to give some quantification to the frequency with which an emergency physician could expect to see corneal abrasions associated with pepper spray exposure. Of 100 cases of pepper spray exposure identified, seven patients had sustained corneal abrasions. We conclude that corneal abrasions are not rare events when patients are exposed to pepper spray and that fluorescein staining and slit lamp or Wood's lamp examination should be performed on all exposed patients in whom corneal abrasions cannot be excluded on clinical grounds. PMID:10830682

  4. A decision aid regarding long-term tube feeding targeting substitute decision makers for cognitively impaired older persons in Japan: A small-scale before-and-after study

    PubMed Central

    2014-01-01

    Background In Japan, there is no decision-making guide regarding long-term tube feeding that specifically targets individuals making decisions on behalf of cognitively impaired older persons (substitute decision makers). The objective of this study was to describe the development and evaluation of such a decision aid. Methods In this before-and-after study, participants comprised substitute decision makers for 13 cognitively impaired inpatients aged 65 years and older who were being considered for placement of a percutaneous endoscopic gastrostomy tube in acute care hospitals and mixed-care hospitals in Japan. Questionnaires were used to compare substitute decision makers’ knowledge, decisional conflict, and predisposition regarding feeding tube placement before and after exposure to a decision aid. The acceptability of the decision aid was also assessed. Paired t-tests were used to compare participants’ knowledge and decisional conflict scores before and after using the decision aid. Results Substitute decision makers showed significantly increased knowledge (P < .001) and decreased decisional conflict (P < .01) regarding long-term tube feeding after using the decision aid. All substitute decision makers found the decision aid helpful and acceptable. Conclusions The decision aid facilitated the decision-making process of substitute decision makers by decreasing decisional conflict and increasing knowledge. PMID:24495735

  5. Evaluation of the educational technology "Caring for dependent people" by family caregivers in changes and transfers of patients and tube feeding 1

    PubMed Central

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

    2016-01-01

    ABSTRACT Objective: 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. Method: 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. Results: 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. Conclusion: 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. PMID:27556879

  6. The abrasion and impact-abrasion behavior of austempered ductile irons

    SciTech Connect

    Hawk, Jeffrey A.; Dogan, Omer N.; Lerner, Y.S.

    1998-01-01

    Austempering of ductile irons has led to a new class of irons, Austempered Ductile Irons (ADIs), with improved mechanical strength and fracture toughness lacking in gray cast irons. Laboratory wear tests have been used to evaluate the abrasive and impact-abrasive wear behavior of a suite of ADIs. The use of high-stress, two-body abrasion, low-stress, three-body abrasion, and impact-abrasion tests provides a clear picture of the abrasive wear behavior of the ADIs and the mechanisms of material removal. When combined with hardness measurements, fracture toughness and a knowledge of the microstructure of the ADIs, the overall performance can be assessed relative to more wear resistant materials such as martensitic steels and high-chromium white cast irons

  7. 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. (a) Identification. An abrasive device and accessories is a device constructed of various abrasives... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Abrasive device and accessories. 872.6010...

  8. 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. (a) Identification. An abrasive device and accessories is a device constructed of various abrasives... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Abrasive device and accessories. 872.6010...

  9. 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. (a) Identification. An abrasive device and accessories is a device constructed of various abrasives... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Abrasive device and accessories. 872.6010...

  10. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  11. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  12. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  13. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  14. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  15. New iron-based SiC spherical composite magnetic abrasive for magnetic abrasive finishing

    NASA Astrophysics Data System (ADS)

    Zhang, Guixiang; Zhao, Yugang; Zhao, Dongbiao; Zuo, Dunwen; Yin, Fengshi

    2013-03-01

    SiC magnetic abrasive is used to polish surfaces of precise, complex parts which are hard, brittle and highly corrosion-resistant in magnetic abrasive finishing(MAF). Various techniques are employed to produce this magnetic abrasive, but few can meet production demands because they are usually time-consuming, complex with high cost, and the magnetic abrasives made by these techniques have irregular shape and low bonding strength that result in low processing efficiency and shorter service life. Therefore, an attempt is made by combining gas atomization and rapid solidification to fabricate a new iron-based SiC spherical composite magnetic abrasive. The experimental system to prepare this new magnetic abrasive is constructed according to the characteristics of gas atomization and rapid solidification process and the performance requirements of magnetic abrasive. The new iron-based SiC spherical composite magnetic abrasive is prepared successfully when the machining parameters and the composition proportion of the raw materials are controlled properly. Its morphology, microstructure, phase composition are characterized by scanning electron microscope(SEM) and X-ray diffraction(XRD) analysis. The MAF tests on plate of mold steel S136 are carried out without grinding lubricant to assess the finishing performance and service life of this new SiC magnetic abrasive. The surface roughness( R a) of the plate worked is rapidly reduced to 0.051 μm from an initial value of 0.372 μm within 5 min. The MAF test is carried on to find that the service life of this new SiC magnetic abrasive reaches to 155 min. The results indicate that this process presented is feasible to prepare the new SiC magnetic abrasive; and compared with previous magnetic abrasives, the new SiC spherical composite magnetic abrasive has excellent finishing performance, high processing efficiency and longer service life. The presented method to fabricate magnetic abrasive through gas atomization and rapid

  16. 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.

  17. PEG tube insertion -- discharge

    MedlinePlus

    ... Search Search MedlinePlus GO GO About MedlinePlus Site ... To use the sharing features on this page, please enable JavaScript. A PEG (percutaneous endoscopic gastrostomy) feeding tube insertion is the placement of ...

  18. [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. PMID:24684041

  19. Abrasive wear of advanced structural materials

    NASA Astrophysics Data System (ADS)

    Lee, Gun-Young

    Wear of advanced structural materials, namely composites and ceramics, in abrasion has been examined in the present study. A simple physically-based model for the abrasive wear of composite materials is presented based on the mechanics and mechanisms associated with sliding wear in soft (ductile) matrix composites containing hard (brittle) reinforcement particles. The model is based on the assumption that any portion of the reinforcement that is removed as wear debris cannot contribute to the wear resistance of the matrix material. The size of this non-contributing portion of reinforcement is estimated by modeling three primary wear mechanisms, specifically plowing, cracking at the matrix/reinforcement interface or in the reinforcement, and particle removal. Critical variables describing the role of the reinforcement, such as the relative size, fracture toughness, and the nature of the matrix/reinforcement interface, are characterized by a single contribution coefficient, C. Predictions are compared with the results of experimental two-body (pin-on-drum) abrasive wear tests performed on a model aluminum particulate-reinforced epoxy-matrix composite material. In addition, the effects of post heat-treatment on the wear behavior of toughened silicon carbide (ABC-SiC) are investigated by characterizing the role of the microstructures introduced during the post annealing processes. When the annealing temperature is above 1300°C, an aluminum rich secondary phase (nano-precipitate) forms and grows inside the SiC grains. This toughened silicon carbide (ABC-SiC), annealed at temperatures ranging from 0 to 1600°C, is subjected to two- and three-body abrasions with different sizes of abrasives (3˜70 mum). The test results exhibit that the effect of nano-precipitates on wear resistance of post-annealed ABC-SiC is restricted to the abrasion with fine abrasives (3 mum), since nano-precipitates, in the range from 4 nm at 1300°C to 25 nm at 1600°C, are comparable in dimension

  20. Air abrasion: an old technology reborn.

    PubMed

    Berry, E A; Eakle, W S; Summitt, J B

    1999-08-01

    Recently, air abrasion has experienced a rebirth in restorative dentistry. Originally developed in the late 1940s, the principle of air abrasion is the imparting of kinetic energy to tiny aluminum oxide particles that are projected by a stream of compressed air or gas and expelled from a small nozzle. The force generated by the relatively hard particles striking a relatively hard surface is sufficient to cut into that surface. In the last decade, more than a dozen models of air abrasion units have been introduced into the marketplace and more are on the way. Manufacturers have developed air abrasion instruments that offer a broad range of features, from small table-top units to self-contained systems with compressors, vacuums, and curing lights. The costs range dramatically--from $1,000 to $20,000 or more--depending on the complexity of the features and attachments. Manufacturers make a variety of claims to support the value of this technology to the practicing dentist. A term often used to describe one of the benefits of air abrasion is microdentistry. The claim is that smaller, less invasive tooth preparations may be accomplished using air abrasion than with a traditional bur and air turbine. This may be true in some instances, but it would certainly depend on the operator's experience and ability to visually discern fine detail. Other claims about air abrasion are that it can be used to cut into tooth structure without local anesthesia and that it should be used on all stained grooves or fissures to determine if incipient carious lesions are present. Despite the limited number of clinical studies, the popularity of air abrasion continues to grow. To gain additional insight about these claims and to see what might be on the horizon for this technology, I spoke with three highly respected educators who are recognized for their expertise in air abrasion. What they said should give the reader a better understanding of how air abrasion might augment restorative

  1. A rotary-airlock valve resists abrasive mixtures

    SciTech Connect

    Not Available

    1993-03-01

    Hill and Griffith (H and G, Cincinnati, Ohio) is a leading supplier of custom-blended additives to founderies. Thousands of tons of clay and carbon blends such as bentonite, gilsonite and pulverized coal, pass through the company's rotary-airlock feeding system each month. H and G's original rotary valves had cylinders lined with chrome, and closed-end rotors with tips made from nickel-chromium alloys. These valves remained in service for a maximum of only three months each. During that time, the abrasive mixtures passing through the valves virtually eroded them, increasing tolerances and causing significant air leakage. The leaks caused the pneumatic line to plug up, reducing the velocity of the line below the minimum level needed to carry any material. To overcome the leakage, a second blower was added to the system. This unit supplied an additional 40 brake hp to the pneumatic-conveying line. With constant maintenance of the valve and the continuous operation of both blowers, H and G was able to extend the valve's life by nine months. After 20 years of trying valves with various configuration, H and G installed a Smoot Type 6 rotary-airlock valve in September of 1985. The new valve's internals were made from abrasion-resistant grades of NiHard and Stellite. This combination of alloys prolonged the active life of the valve by improving its abrasion resistance. During its first year, the Smoot valve did not break down, leak air or require use of the secondary blower. After its first year of service no wear was found on the valve's internal surfaces. Another mechanical analysis was performed in 1991, after five additional years of valve operation. The valve, which had now handled more than 250,000 tons of product, showed minimal wear. H and G's capital costs had been reduced from 25[cents]/ton to 3[cents]/ton by the new valve.

  2. Abrasion resistance of medical glove materials.

    PubMed

    Walsh, Donna L; Schwerin, Matthew R; Kisielewski, Richard W; Kotz, Richard M; Chaput, Maria P; Varney, George W; To, Theresa M

    2004-01-15

    Due to the increasing demand for nonlatex medical gloves in the health-care community, there is a need to assess the durability of alternative glove materials. This study examines durability characteristics of various glove materials by abrasion resistance testing. Natural rubber latex (latex), polyvinyl chloride (vinyl), acrylonitrile butadiene (nitrile), polychloroprene (neoprene), and a styrene-ethylene/butylene-styrene block copolymer (SEBS) were tested. All test specimens, with the exception of the vinyl, were obtained from surgical gloves. Unaged out-of-the-box specimens as well as those subjected to various degrees of artificial aging were included in the study. After the abrasion sequence, the barrier integrity of the material was assessed through the use of a static leak test. Other traditional tests performed on these materials were viral penetration to validate the abrasion data and tear testing for comparative purposes. The results indicate that specific glove-material performance is dependent upon the particular test under consideration. Most notably, abrasion, even in controlled nonsevere conditions, may compromise to varying degrees the barrier integrity of latex, vinyl, SEBS, nitrile, and neoprene glove materials. However, as evidenced by the results of testing three brands of neoprene gloves, the abrasion resistance of any one glove material may be significantly affected by variations in production processes. PMID:14689500

  3. 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.

  4. Tooth length and incisal wear and growth in guinea pigs (Cavia porcellus) fed diets of different abrasiveness.

    PubMed

    Müller, J; Clauss, M; Codron, D; Schulz, E; Hummel, J; Kircher, P; Hatt, J-M

    2015-06-01

    Dental diseases are among the most important reasons for presenting guinea pigs (Cavia porcellus) and other rodents to veterinary clinics, but the aetiopathology of this disease complex is unclear. Clinicians tend to believe that the ever-growing teeth of rabbits and rodents have a constant growth that needs to be worn down by the mastication of an appropriate diet. In this study, we tested the effect of four different pelleted diets of increasing abrasiveness [due to both internal (phytoliths) and external abrasives (sand)] or whole grass hay fed for 2 weeks each in random order to 16 guinea pigs on incisor growth and wear, and tooth length of incisors and cheek teeth. There was a positive correlation between wear and growth of incisors. Tooth lengths depended both on internal and external abrasives, but only upper incisors were additionally affected by the feeding of whole hay. Diet effects were most prominent in anterior cheek teeth, in particular M1 and m1. Cheek tooth angle did not become shallower with decreasing diet abrasiveness, suggesting that a lack of dietary abrasiveness does not cause the typical 'bridge formation' of anterior cheek teeth frequently observed in guinea pigs. The findings suggest that other factors than diet abrasiveness, such as mineral imbalances and in particular hereditary malocclusion, are more likely causes for dental problems observed in this species. PMID:25041439

  5. Corneal Abrasions and Corneal Foreign Bodies.

    PubMed

    Ahmed, Faheem; House, Robert James; Feldman, Brad Hal

    2015-09-01

    Corneal abrasions and corneal foreign bodies are frequently encountered ophthalmological injuries that are commonly diagnosed and managed by primary care physicians. The clinical course of a corneal epithelial defect can range from a relatively benign self-healing abrasion to a potentially sight-threatening complication such as a corneal ulcer, recurrent erosion, or traumatic iritis. A detailed clinical history regarding risk factors and exposure, along with a thorough slit lamp examination with fluorescein dye are essential for proper diagnosis and treatment, as well as to rule out penetrating globe injuries. Referral to an ophthalmologist is recommended in difficult cases or if other injuries are suspected. PMID:26319343

  6. 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.

  7. Universal scaling relations for pebble abrasion

    NASA Astrophysics Data System (ADS)

    Litwin, K. L.; Jerolmack, D. J.

    2012-12-01

    The process of abrasion of gravel in bed load transport results from particle-to-particle collisions, where the energy involved is sufficient to cause chipping and spallation but not fragmentation of parent grains. The removed rock material is not infinitesimal; daughter products as large as coarse sand can be produced. Although previous work has shown that lithology, grain shape, and energy of collision are contributing factors that control abrasion rates of river-bed material, little is known regarding the relationship between these factors and diminution rates. Here we explicitly isolate and investigate how these three factors influence rates of abrasion and the size distribution of daughter products, with laboratory experiments. The apparatus is a double pendulum (Newton's cradle) that produces well-controlled binary collisions. A high-speed camera precisely measures collision energy, while mass of parent rocks. and the size and shape distributions of daughter products, are measured periodically. We examined abrasion of initially square-cut 'rocks' as they underwent successive collisions in the binary collision apparatus. We have examined mass loss rate for varied lithologies, and observe a similar power-law relationship between impact energy and mass abraded. When normalized by sensible material properties, mass loss curves for all materials collapse onto a single curve, suggesting that the underlying mechanics of abrasion for different materials are the same. The relationship does not display the linear trend expected from pure energetics, and we suggest that this is a shape effect as protruding - and hence easily eroded - corners are worn away. Analysis of daughter-product particle size distributions for different lithology fragments - including natural rocks and also bricks - show the same functional form. Surprisingly, it is the power-law relation expected for brittle materials undergoing fragmentation. This suggests that brittle fracture theory also

  8. Recent progress of abrasion-resistant materials: learning from nature.

    PubMed

    Meng, Jingxin; Zhang, Pengchao; Wang, Shutao

    2016-01-21

    Abrasion-resistant materials have attracted great attention for their broad applications in industry, biomedicine and military. However, the development of abrasion-resistant materials that have with unique features such as being lightweight and flexible remains a great challenge in order to satisfy unmet demands. The outstanding performance of natural abrasion-resistant materials motivates the development of new bio-inspired abrasion-resistant materials. This review summarizes the recent progress in the investigation of natural abrasion-resistant materials to explore their general design principles (i.e., the correlation between chemical components and structural features). Following natural design principles, several artificial abrasion-resistant materials have shown unique abrasion-resistant properties. The potential challenges in the future and possible solutions for designing bio-inspired abrasion-resistant materials are also briefly discussed. PMID:26335377

  9. 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

  10. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... exceeded. (j) All employees using abrasive wheels shall be protected by eye protection equipment in accordance with the requirements of subpart I of this part except when adequate eye protection is afforded by eye shields which are permanently attached to the bench or floor stand....

  11. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  12. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  13. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  14. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  15. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... spindle speed under all conditions of normal grinding. The rated maximum speed of the wheel shall not be...) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with safety guards (protection hoods). The maximum angular exposure of the grinding wheel periphery and sides...

  16. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... spindle speed under all conditions of normal grinding. The rated maximum speed of the wheel shall not be...) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with safety guards (protection hoods). The maximum angular exposure of the grinding wheel periphery and sides...

  17. Evaluation and Treatment of Perioperative Corneal Abrasions

    PubMed Central

    Segal, Kira L.; Fleischut, Peter M.; Kim, Charles; Levine, Ben; Faggiani, Susan L.; Banerjee, Samprit; Gadalla, Farida; Lelli, Gary J.

    2014-01-01

    Purpose. To evaluate perioperative risk factors for corneal abrasion (CA) and to determine current care for perioperative CA in a tertiary care setting. Methods. Hospital-based, cross-sectional study. In Operating Room and Post-Anesthesia Care Units patients, a comparison of cases and controls was evaluated to elucidate risk factors, time to treatment, and most common treatments prescribed for corneal abrasions. Results. 86 cases of corneal abrasion and 89 controls were identified from the 78,542 surgical procedures performed over 2 years. Statistically significant risk factors were age (P = 0.0037), general anesthesia (P < 0.001), greater average estimated blood loss (P < 0.001), eyes taped during surgery (P < 0.001), prone position (P < 0.001), trendelenburg position (P < 0.001), and supplemental oxygen en route to and in the Post-Anesthesia Care Units (P < 0.001). Average time to complaint was 129 minutes. 94% of cases had an inpatient ophthalmology consult, with an average time to consult of 164 minutes. The most common treatment was artificial tears alone (40%), followed by combination treatment of antibiotic ointment and artificial tears (35.3%). Conclusions. Trendelenburg positioning is a novel risk factor for CA. Diagnosis and treatment of perioperative corneal abrasions by an ophthalmologist typically require three hours in the tertiary care setting. PMID:24672709

  18. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  19. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Tools and Related...

  20. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Tools and Related...

  1. Dust transport and abrasion assessment within simulated standing vegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop residues are useful in protecting the top soil from depletion and abrasion due to wind erosion. A wind tunnel study was done to measure sand transport and abrasion energies within the simulated artificial standing vegetation. Wind profiles, relative abrasion energies and rates of sand dischar...

  2. Relationship between abrasive wear and microstructure of composite resins.

    PubMed

    Draughn, R A; Harrison, A

    1978-08-01

    The in vitro abrasion resistance of seven commercial composite resin restorative materials has been measured. Analysis of the composite microstructures shows that abrasion rates are dependent upon the size, hardness, and volume fraction of particles in the material. The most abrasion-resistant composites contain a high volume fraction of large, hard particles. PMID:278840

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Oral cavity abrasive polishing agent. 872.6030... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing agent. (a) Identification. An oral cavity abrasive polishing agent is a device in paste or powder...

  4. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Oral cavity abrasive polishing agent. 872.6030... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing agent. (a) Identification. An oral cavity abrasive polishing agent is a device in paste or powder...

  5. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oral cavity abrasive polishing agent. 872.6030... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing agent. (a) Identification. An oral cavity abrasive polishing agent is a device in paste or powder...

  6. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Oral cavity abrasive polishing agent. 872.6030... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing agent. (a) Identification. An oral cavity abrasive polishing agent is a device in paste or powder...

  7. 21 CFR 872.6030 - Oral cavity abrasive polishing agent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Oral cavity abrasive polishing agent. 872.6030... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing agent. (a) Identification. An oral cavity abrasive polishing agent is a device in paste or powder...

  8. 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.

  9. 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.

  10. Wheel Abrasion Experiment Conducted on Mars

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.

    1998-01-01

    Sojourner rover showing Lewis' wheel abrasion experiment. The Mars Pathfinder spacecraft soft-landed on Mars on July 4, 1997. Among the many experiments on its small Sojourner rover are three technology experiments from the NASA Lewis Research Center, including the Wheel Abrasion Experiment (WAE). The WAE was designed, built, delivered, and operated on Mars by a team of engineers and scientists from Lewis' Photovoltaics and Space Environments Branch. This experiment collected data to assess wheel surface wear on the Sojourner. It used a specially designed rover wheel, with thin films (200 to 1000 angstroms) of aluminum, nickel, and platinum deposited on black, anodized aluminum strips attached to the rover's right center wheel. As the wheel spun in the Martian soil, a photovoltaic sensor monitored changes in film reflectivity. These changes indicated abrasion of the metal films by Martian surface material. Rolling wear data were accumulated by the WAE. Also, at frequent intervals, all the rover wheels, except the WAE test wheel, were locked to hold the rover stationary while the test wheel alone was spun and dug into the Martian regolith. These tests created wear conditions more severe than simple rolling. The WAE will contribute substantially to our knowledge of Martian surface characteristics. Marked abrasion would indicate a surface composed of hard, possibly sharply edged grains, whereas lack of abrasion would suggest a somewhat softer surface. WAE results will be correlated with ground simulations to determine which terrestrial materials behave most like those on Mars. This knowledge will enable a deeper understanding of erosion processes on Mars and the role they play in Martian surface evolution. Preliminary results show that electrostatic charging of the rover wheels sometimes caused dust to accumulate on the WAE wheel, making interpretation of the reflectance data problematic. If electrostatic charging is the mechanism for dust attraction, this indicates

  11. Abrasion resistance of linings in filament wound composite pipe

    SciTech Connect

    Hall, S.C.

    1999-07-01

    Fiberglass filament wound composite pipe has numerous industrial applications including transportation of petroleum and natural gas. Its corrosion resistance is well known but it can be susceptible to abrasion and erosion when it is used to transport slurries or dry gas containing sand particles. However, composite pipe can be manufactured integrally with abrasion resistant linings which protect the pipe from abrasion and erosion and increase its life. Laboratory investigations were performed to determine the effect of abrasive flows through polyurea-lined and unlined glass-reinforced epoxy (GRE) pipe, ultra-high molecular weight (UHMW) polyethylene (PE) pipe, and unlined steel pipe. Results are provided for the abrasion resistance, chemical resistance, adhesion strength, elongation, tensile strength, impact resistance and hardness of selected linings. The abrasion resistance of polyurea-lined composite pipe proved to be almost as resistant to abrasion and erosion as unlined steel pipe without the electrochemical corrosion associated with steel pipe.

  12. Abrasion-Resistant Technology and its Prospect for CFB Boilers

    NASA Astrophysics Data System (ADS)

    Zheng, H.; Li, Y. J.; Wang, L. J.; Liu, S. H.; Dou, Q. R.

    In recent years, CFB boilers (CFBB) have been widely used in the commercial power plants due to its environmental benefits, high combustion efficiency, wide coal flexibility, and some other advantages. At the same time, the abrasion problem, the greatest weakness of this kind of boiler, has been gradually exposed in its application process. The abrasion, particularly on key parts such as the heating surface of water-cooled wall, furnace corners, separator entrance, seriously restricts the long-period operation ability of the CFBB. This article discusses current development status for various abrasion resistant refractory materials used in a CFBB. Some comments are provided for developing new high-performance abrasion resistant refractory materials and rapid-repaired materials according to the abrasion principle and the abrasion on different parts, as well as the economical and environmental requirements for the material. The abrasion solution and operation period of CFBB can be better improved given realization.

  13. Ear Tubes

    MedlinePlus

    ... Meeting Calendar Find an ENT Doctor Near You Ear Tubes Ear Tubes Patient Health Information News media ... and throat specialist) may be considered. What are ear tubes? Ear tubes are tiny cylinders placed through ...

  14. Liquid abrasive pressure pot scoping tests report

    SciTech Connect

    Archibald, K.E.

    1996-01-01

    The primary initiatives of the LITCO Decontamination Development group at the Idaho Chemical Process Plant (ICPP) are the development of methods to eliminate the use of sodium bearing decontamination chemicals and minimization of the amount of secondary waste generated during decontamination activities. In July of 1994, a Commerce Business Daily (CBD) announcement was issued by the INEL to determine commercial interest in the development of an in-situ liquid abrasive grit blasting system. As a result of the CBD announcement, Klieber & Schulz issued an Expression of Interest letter which stated they would be interested in testing a prototype Liquid Abrasive Pressure Pot (LAPP). LITCO`s Decontamination group and Kleiber & Schulz entered into a Cooperative Research and Development Agreement (CRADA) in which the Decontamination Development group tested the prototype LAPP in a non-radioactive hot cell mockup. Test results are provided.

  15. Loose abrasive slurries for optical glass lapping

    SciTech Connect

    Neauport, Jerome; Destribats, Julie; Maunier, Cedric; Ambard, Chrystel; Cormont, Philippe; Pintault, B.; Rondeau, Olivier

    2010-10-20

    Loose abrasive lapping is widely used to prepare optical glass before its final polishing. We carried out a comparison of 20 different slurries from four different vendors. Slurry particle sizes and morphologies were measured. Fused silica samples were lapped with these different slurries on a single side polishing machine and characterized in terms of surface roughness and depth of subsurface damage (SSD). Effects of load, rotation speed, and slurry concentration during lapping on roughness, material removal rate, and SSD were investigated.

  16. 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.

  17. 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.

  18. Predicting abrasive wear with coupled Lagrangian methods

    NASA Astrophysics Data System (ADS)

    Beck, Florian; Eberhard, Peter

    2015-05-01

    In this paper, a mesh-less approach for the simulation of a fluid with particle loading and the prediction of abrasive wear is presented. We are using the smoothed particle hydrodynamics (SPH) method for modeling the fluid and the discrete element method (DEM) for the solid particles, which represent the loading of the fluid. These Lagrangian methods are used to describe heavily sloshing fluids with their free surfaces as well as the interface between the fluid and the solid particles accurately. A Reynolds-averaged Navier-Stokes equations model is applied for handling turbulences. We are predicting abrasive wear on the boundary geometry with two different wear models taking cutting and deformation mechanisms into account. The boundary geometry is discretized with special DEM particles. In doing so, it is possible to use the same particle type for both the calculation of the boundary conditions for the SPH method as well as the DEM and for predicting the abrasive wear. After a brief introduction to the SPH method and the DEM, the handling of the boundary and the coupling of the fluid and the solid particles are discussed. Then, the applied wear models are presented and the simulation scenarios are described. The first numerical experiment is the simulation of a fluid with loading which is sloshing inside a tank. The second numerical experiment is the simulation of the impact of a free jet with loading to a simplified pelton bucket. We are especially investigating the wear patterns inside the tank and the bucket.

  19. Circular Signs of the Rock Abrasion Tool

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image was taken by Mars Exploration Rover Opportunity's front hazard-avoidance camera, providing a circular sign of the success of the rover's first grinding of a rock. The round, shallow hole seen in this image is on a rock dubbed 'McKittrick,' located in the 'El Capitan' area of the larger outcrop near Opportunity's landing site.

    Opportunity used its rock abrasion tool to grind off a patch of rock 45.5 millimeters (1.8 inches) in diameter during the 30th martian day, or sol, of its mission (Feb. 23, 2004). The grinding exposed fresh rock for close inspection by the rover's microscopic imager and two spectrometers located on its robotic arm. The Honeybee Robotics team, which designed and operates the rock abrasion tool, determined the depth of the cut at 'McKittrick' to be 4.4 millimeters (0.17 inches) deep.

    On sol 34 (Feb. 27, 2004), the rover is scheduled to grind into its second target on the 'El Capitan' area, a rock dubbed 'Guadalupe' in the upper middle part of this image. The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y.

  20. Kerf modelling in abrasive waterjet milling using evolutionary computation and ANOVA techniques

    NASA Astrophysics Data System (ADS)

    Alberdi, A.; Rivero, A.; Carrascal, A.; Lamikiz, A.

    2012-04-01

    Many researchers demonstrated the capability of Abrasive Waterjet (AWJ) technology for precision milling operations. However, the concurrence of several input parameters along with the stochastic nature of this technology leads to a complex process control, which requires a work focused in process modelling. This research work introduces a model to predict the kerf shape in AWJ slot milling in Aluminium 7075-T651 in terms of four important process parameters: the pressure, the abrasive flow rate, the stand-off distance and the traverse feed rate. A hybrid evolutionary approach was employed for kerf shape modelling. This technique allowed characterizing the profile through two parameters: the maximum cutting depth and the full width at half maximum. On the other hand, based on ANOVA and regression techniques, these two parameters were also modelled as a function of process parameters. Combination of both models resulted in an adequate strategy to predict the kerf shape for different machining conditions.

  1. A new dimension to conservative dentistry: Air abrasion

    PubMed Central

    Hegde, Vivek S; Khatavkar, Roheet A

    2010-01-01

    Air abrasion dentistry has evolved over a period of time from a new concept of an alternative means of cavity preparation to an essential means of providing a truly conservative preparation for preservation of a maximal sound tooth structure. The development of bonded restorations in combination with air abrasion dentistry provides a truly minimal intervention dentistry. This article reviews the development of air abrasion, its clinical uses, and the essential accessories required for its use. PMID:20582212

  2. Machining human dentin by abrasive water jet drilling.

    PubMed

    Kohorst, Philipp; Tegtmeyer, Sven; Biskup, Christian; Bach, Friedrich-Wilhelm; Stiesch, Meike

    2014-01-01

    The aim of this experimental in-vitro study was to investigate the machining of human dentin using an abrasive water jet and to evaluate the influence of different abrasives and water pressures on the removal rate. Seventy-two human teeth had been collected after extraction and randomly divided into six homogeneous groups (n=12). The teeth were processed in the area of root dentin with an industrial water jet device. Different abrasives (saccharose, sorbitol, xylitol) and water pressures (15 or 25 MPa) were used in each group. Dimensions of dentin removal were analysed using a stripe projection microscope and both drilling depth as well as volume of abrasion were recorded. Morphological analyses of the dentin cavities were performed using scanning electron microscopy (SEM). Both drilling depth and volume of abrasion were significantly influenced by the abrasive and the water pressure. Depending on these parameters, the drilling depth averaged between 142 and 378 μm; the volume of abrasion averaged between 0.07 and 0.15 mm3. Microscopic images revealed that all cavities are spherical and with clearly defined margins. Slight differences between the abrasives were found with respect to the microroughness of the surface of the cavities. The results indicate that abrasive water jet machining is a promising technique for processing human dentin. PMID:24642975

  3. The dollars and sense of selecting abrasion-resistant materials

    SciTech Connect

    Jackson, D.

    1988-05-01

    Sliding abrasion and impact damage affect mine and plant operating costs on a month-to-month, or, in some cases, day-to-day basis. Modern technology has given us the tools necessary to fight abrasion on every front - materials and techniques that are cost-effective, long-lasting, and easy to use. An inspection of abrasion-resistant materials and processes - metals; ceramics; sprayable and trowelable compounds; polyethylene; urethane; rubber; epoxy - may well provide information that could help improve your company's balance sheet. The following is a compilation of product releases, literature, and manuals offered by manufacturers of abrasion-resistant materials.

  4. Pebble Jammed in Rock Abrasion Tool

    NASA Technical Reports Server (NTRS)

    2004-01-01

    After the rock abrasion tool on NASA's Mars Exploration Rover Opportunity stopped working on sol 199 (Aug. 15, 2004), rover operators used the panoramic camera to take this image the next day for help in diagnosing the problem. The tool was closer than the camera could focus on sharply, but the image does show a dark spot just left of center, which engineers have determined is likely to be a pebble jammed between the cutting-blade rotor and the wire-brush rotor. If that diagnosis is confirmed by further analysis, the tool will likely be commanded to turn the rotors in reverse to release the pebble.

  5. 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.

  6. 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.

  7. 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.

  8. Mars Exploration Rovers' Rock Abrasion Tool

    NASA Astrophysics Data System (ADS)

    Gorevan, S.; Myrick, T.; Davis, K.; Ji, J.; Bartlett, P.; Mukherjee, S.; Arafat, T.

    2003-04-01

    Each of the twin 2003 Mars Exploration Rovers will be equipped with a Rock Abrasion Tool (RAT) designed and tested by Honeybee Robotics. The RAT is a robotic grinding tool and science instrument about the size of a soda can and weighing less than 690 grams that is carried by the robotic arm or Instrument Deployment Device (IDD) of the rover. The primary purpose of the RAT is to remove the dust and surface rind from Mars rock targets to reveal the underlying petrographic features. After the RAT is placed and preloaded against the target rock by the IDD, all operations of the RAT are performed autonomously. Using three small motors to drive the rotation, revolve and z-axis subassemblies the RAT removes a 45 mm diameter, 5 mm deep patch of rock. The RAT has a resin-bonded diamond abrasion wheel and two brushes to provide a clean observation surface for the three surface instruments - APXS, Microscopic Imager and Moessbauer Spectrometer. Detailed design and operation descriptions, as well as recent qualification and operational testing results will be presented.

  9. Caring for Tube-Fed Children: A Review of Management, Tube Weaning, and Emotional Considerations.

    PubMed

    Edwards, Sarah; Davis, Ann M; Bruce, Amanda; Mousa, Hayat; Lyman, Beth; Cocjin, Jose; Dean, Kelsey; Ernst, Linda; Almadhoun, Osama; Hyman, Paul

    2016-07-01

    Enteral nutrition is the practice of delivering nutrition to the gut either orally or through a tube or other device. Many children are reliant on enteral feedings to either supplement their nutrition or as a complete source of their nutrition. Managing children on tube feedings requires a team of providers to work through such dilemmas as feeding schedules, weaning from tube feeding, sensory implications of tube feeding, treatment of pain or nausea associated with eating, oral-motor issues, and behavioral issues in the child and family. The purpose of the current review is to summarize the multidisciplinary aspects of enteral feeding. The multidisciplinary team consists of a variable combination of an occupational therapist, speech-language pathologist, gastroenterologist, psychologist, nurse, pharmacist, and dietitian. Children who have minimal oral feeding experience and are fed via a nasogastric or gastrostomy tube often develop oral aversions. Limited data support that children with feeding disorders are more likely to have sensory impairment and that early life pain experiences contribute to feeding refusal. There are inpatient and outpatient programs for weaning patients from tube feeding to eating. The parent-child interaction is an important part of the assessment and treatment of the tube-fed child. This review also points out many information gaps, including data on feeding schedules, blenderized tube feedings, the best methods for weaning children off enteral feedings, the efficacy of chronic pain medications with tube-fed children, and, finally, the necessity of the assessment of parental stress among all parents of children who are tube fed. PMID:25791833

  10. 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.

  11. Soybean seedlings tolerate abrasion from air-propelled grit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New tools for controlling weeds would be useful for soybean production in organic systems. Air-propelled abrasive grit is one such tool that performs well for in-row weed control in corn, but crop safety in soybean is unknown. We examined responses to abrasion by corn-cob grit of soybean seedlings a...

  12. Sand abrasion injury and biomass partitiioning in cotton seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind blown soil particle abrasion negatively impacts millions of hectares of crops annually. The goal of this study was to examine the effects of wind and wind blown sand abrasion damage on cotton (Gossypium hirsutum L.) seedling biomass partitioning to leaves, stems, and roots. Seedlings of three ...

  13. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain...

  14. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Abrasive device and accessories. 872.6010 Section 872.6010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and...

  15. 21 CFR 872.6010 - Abrasive device and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Abrasive device and accessories. 872.6010 Section 872.6010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6010 Abrasive device and...

  16. Abrasion of 6 dentifrices measured by vertical scanning interference microscopy

    PubMed Central

    PASCARETTI-GRIZON, Florence; MABILLEAU, Guillaume; CHAPPARD, Daniel

    2013-01-01

    Objectives The abrasion of dentifrices is well recognized to eliminate the dental plaque. The aims of this study were to characterize the abrasive powders of 6 dentifrices (3 toothpastes and 3 toothpowders) and to measure the abrasion on a test surface by Vertical Scanning Interference microscopy (VSI). Material and Methods Bright field and polarization microscopy were used to identify the abrasive particles on the crude dentifrices and after prolonged washes. Scanning electron microscopy and microanalysis characterized the shape and nature of the particles. Standardized and polished blocks of poly(methylmethacrylate) were brushed with a commercial electric toothbrush with the dentifrices. VSI quantified the mean roughness (Ra) and illustrated in 3D the abraded areas. Results Toothpastes induced a limited abrasion. Toothpowders induced a significantly higher roughness linked to the size of the abrasive particles. One powder (Gencix® produced a high abrasion when used with a standard testing weight. However, the powder is based on pumice particles covered by a plant homogenate that readily dissolves in water. When used in the same volume, or after dispersion in water, Ra was markedly reduced. Conclusion Light and electron microscopy characterize the abrasive particles and VSI is a new tool allowing the analysis of large surface of abraded materials. PMID:24212995

  17. Sand abrasion injury and biomass partitioning in cotton seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind blown soil particle abrasion negatively impacts millions of hectares of crops annually. The goal of this study was to examine the effects of wind and wind blown sand abrasion damage on cotton (Gossypium hirsutum L.) seedling biomass partitioning to leaves, stems, and roots. Seedlings of three ...

  18. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of the American National Standard Safety Code for the Use, Care, and Protection of Abrasive Wheels... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery....

  19. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of the American National Standard Safety Code for the Use, Care, and Protection of Abrasive Wheels... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery....

  20. Cotton seedling abrasion and recovery from wind blown sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of crops are exposed to wind blown sand abrasion each year and in many instances the damage is thought to be severe enough to require replanting. The goal of this study was to determine the effects of wind blown sand abrasion duration on cotton (Gossypium hirsutum L.) seedlings...

  1. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Abrasive wheel machinery. 1910.215 Section 1910.215 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a... wheel in motion. (5) Excluded machinery. Natural sandstone wheels and metal, wooden, cloth, or...

  2. Sand abrasion injury and biomass partitioning in cotton seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of acres of crops are exposed to wind blown sand abrasion injury each year and in many instances the damage is thought to be sufficiently severe to require replanting. The goal of this study was to determine the effects of wind blown sand abrasion duration on cotton seedlings. Seedlings of ...

  3. Microfracture patterns of abrasive wear striations on teeth indicate directionality.

    PubMed

    Gordon, K R

    1984-03-01

    A method is described that will indicate the direction that an abrasive particle was traveling as it scored the surface of a brittle material. Light and scanning electron micrographs of glass, dentine, and enamel abraded by loose and, steel carbide, and diamond indicate that partial Hertzian fracture cones are formed at the margins of wear striations during abrasion. The bases of these fracture cones face in the direction of travel of the abrasive particle and, therefore, indicate directionality. Because this method is based only on the consistent geometry of fracturing of brittle materials, it is independent of the loading of the abrasive particle. The only other method available to determine directionality of striations is unreliable since it uses the width of striations, and, hence, is dependent upon a consistent loading regime of the abrasive particle. This new method has direct application for determining the direction of movement of the jaws during mastication in living or fossil animals. PMID:6731603

  4. Solidification Structure and Abrasion Resistance of High Chromium White Irons

    SciTech Connect

    Dogan, O.N.; Hawk, J.A.; Laird, George, II

    1997-06-01

    Superior abrasive wear resistance, combined with relatively low production costs, makes high Cr white cast irons (WCIs) particularly attractive for applications in the grinding, milling, and pumping apparatus used to process hard materials. Hypoeutectic, eutectic, and hypereutectic cast iron compositions, containing either 15 or 26 wt pct chromium, were studied with respect to the macrostructural transitions of the castings, solidification paths, and resulting microstructures when poured with varying superheats. Completely equiaxed macrostructures were produced in thick section castings with slightly hypereutectic compositions. High-stress abrasive wear tests were then performed on the various alloys to examine the influence of both macrostructure and microstructure on wear resistance. Results indicated that the alloys with a primarily austenitic matrix had a higher abrasion resistance than similar alloys with a pearlitic/bainitic matrix. Improvement in abrasion resistance was partially attributed to the ability of the austenite to transform to martensite at the wear surface during the abrasion process.

  5. Solidification structure and abrasion resistance of high chromium white irons

    SciTech Connect

    Dogan, O.N.; Hawk, J.A.; Laird, G. II

    1997-06-01

    Superior abrasive wear resistance, combined with relatively low production costs, makes high Cr white cast irons (WCIs) particularly attractive for applications in the grinding, milling, and pumping apparatus used to process hard materials. Hypoeutectic, eutectic, and hypereutectic cast iron compositions, containing either 15 or 26 wt pct chromium, were studied with respect to the macrostructural transitions of the castings, solidification paths, and resulting microstructures when poured with varying superheats. Completely equiaxed macrostructures were produced in thick section castings with slightly hypereutectic compositions. High-stress abrasive wear tests were then performed on the various alloys to examine the influence of both macrostructure and microstructure on wear resistance. Results indicated that the alloys with a primarily austenitic matrix had a higher abrasion resistance than similar alloys with a pearlitic/bainitic matrix. Improvement in abrasion resistance was partially attributed to the ability of the austenite to transform to martensite at the wear surface during the abrasion process.

  6. Design of an impact abrasion testing machine

    NASA Astrophysics Data System (ADS)

    Zhang, D.; Beeley, P. R.; Baker, A. J.

    1994-04-01

    By using a cam-flat follower-impact shaft with a crank-flat rotating anvil system, the machine to be described can create various impact abrasion conditions to simulate a large range of industrial situations encountered in this field. The main features of the machine are the long working life of the flat rotating anvil, which works in the same way as that of the disk in a pin-on-disk wear tester, and the accurate control of both the impact energy delivered to the specimen and the total sliding distance of the specimen on the anvil. Statistical analysis of test results on the machine with EN24 steel and cast high manganese steel shows that the uncertainty of the population mean is within +/- 4.7% of the sample mean under a 95% confidence level of student distribution, which indicates a very good accuracy of test.

  7. Feeding gastrostomy. Assistant or assassin?

    PubMed

    Burtch, G D; Shatney, C H

    1985-04-01

    Following several deaths from pulmonary aspiration in severely ill or chronically debilitated patients receiving nasogastric tube feedings, a study was undertaken to determine the incidence of aspiration pneumonitis in patients with feeding gastrostomies. During a 15-month interval, 22 feeding gastrostomies and nine feeding jejunostomies were performed. In the former group, eight patients experienced aspiration pneumonitis, with two deaths. Six patients with Stamm gastrostomies and two patients with permanent mucosal-lined gastrostomies experienced pulmonary aspiration. In contrast, aspiration pneumonia did not occur in our small series of patients with feeding jejunostomies. The high incidence of pulmonary aspiration in patients with feeding gastrostomies strongly suggests that, for chronic enteral nutrition in patients who are unable to protect their airway, a feeding jejunostomy is preferable to a feeding gastrostomy. PMID:3920939

  8. Mechanics, kinematics and geometry of pebble abrasion from binary collisions

    NASA Astrophysics Data System (ADS)

    Miller, K. L.; Jerolmack, D. J.

    2014-12-01

    As sediment is transported downstream as bedload, it collides with the bed causing sharp edges to chip and wear away, rounding the rock through the process of abrasion. Previous work has linked abrasion to downstream fining and rounding of grains, however, there has been little attempt to understand the underlying kinematics of abrasion. Furthermore, most studies neglect the fine particle produced during the abrasion process, as the initial grain gets smaller and rounder. In this research, we preform well-controlled laboratory experiments to determine the functional dependence between impact energy and mass lost from abrasion. We use a double-pendulum "Newton's Cradle" set-up to examine the abrasion between two grains and with a high-speed camera, we can quantify the impact energies during collision. Results from experiments verify that mass loss is proportional to kinetic energy. We define a material parameter that incorporates material density, Young's modulus, and tensile stress and show that this parameter is directly related to the proportionality between mass loss and energy. We identify an initial region of the mass loss curves in which abrasion is independent of energy and material properties; results suggest this region is determined by shape. We show that grain size distributions of daughter products are universal and independent of material; they follow a Weibull distribution, which is expected distribution from brittle fracture theory. Finally, scanning electron microscope (SEM) images show a thin damage zone near the surface, suggesting that collision energy is attenuated over some small skin depth. Overall, we find that pebble abrasion by collision can be characterized by two universal scaling relations - the mass loss versus energy curves and the size distribution of daughter products. Results will be useful for estimating expected abrasion rates in the field, and additionally demonstrate that low-energy collisions produce large quantities of sand

  9. The effects of abrasives on electrical submersible pumps

    SciTech Connect

    Wilson, B.L. )

    1990-06-01

    The electrical submersible pump (ESP) is a high-speed rotating device. Its operational life in oil wells can depend on the type and quantities of abrasives present in the produced fluid. This paper reports on a set of experiments performed in a specialized abrasive test loop. In the test, the size and quantity of abrasives were varied along with flow rate through the pump. This paper also examines recent literature on sand production and explores some of the practical problems in sand measurement.

  10. 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.

  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. PMID:27367629

  12. 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.

  13. 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.

  14. Image tubes

    SciTech Connect

    Csorba, I.P.

    1985-01-01

    This text provides a wealth of valuable, hard-to-find data on electron optics, imaging, and image intensification systems. The author explains details of image tube theory, design, construction, and components. He includes material on the design and operation of camera tubes, power components, and secondary electron emitters, as well as data on photomultiplier tubes and electron guns.

  15. Improved wound healing in blue LED treated superficial abrasions

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Tatini, Francesca; Pini, Roberto; Bacci, Stefano; De Siena, Gaetano; Cicchi, Riccardo; Pavone, Francesco; Alfieri, Domenico

    2013-06-01

    A blue-LED photocoagulator device was designed in order to induce a selective photocoagulation effect in superficial bleeding. An in vivo study in rat back skin evidenced an improved healing process in the LED treated abrasions.

  16. Resistance of dentin coating materials against abrasion by toothbrush.

    PubMed

    Gando, Iori; Ariyoshi, Meu; Ikeda, Masaomi; Sadr, Alireza; Nikaido, Toru; Tagami, Junji

    2013-01-01

    Thin-film coating of root dentin surface by all-in-one adhesives has been shown to be an effective option to prevent root surface caries. The purpose of this study was to investigate the wear resistance against toothbrush abrasion of two all-in-one coating materials; Shield Force (SF) and Hybrid Coat (HC). Bovine dentin surfaces were covered with one of the coating materials; SF or HC. After storage in water for 24 h, the testing surface was subjected to the toothbrush abrasion test up to 50,000 cycles either in water or toothpaste slurry. The remaining thickness of the coating material was measured using SEM. Toothpaste slurry significantly increased rate of tooth brush abrasion of the coating materials. While SF and HC wore at a similar pace under toothbrush abrasion, SF had a thicker coat and could protect dentin longer, up to 50,000 cycles. PMID:23370872

  17. Dermoscopy and Onychomycosis: guided nail abrasion for mycological samples*

    PubMed Central

    Bet, Diego Leonardo; dos Reis, Ana Lucia; Chiacchio, Nilton Di; Belda Junior, Walter

    2015-01-01

    Mycological examination is still the cornerstone for the diagnosis of onychomycosis for many dermatologists, but sampling technique interferes on its sensitivity and specificity. Nail abrasion may be used to reach the most proximal part of the lesion and can be easily accomplished with an electric abrasor. We suggest nail plate dermoscopy to identify the best location for localized abrasion to obtain adequate samples for mycological examination. PMID:26734877

  18. Dermoscopy and Onychomycosis: guided nail abrasion for mycological samples.

    PubMed

    Bet, Diego Leonardo; Reis, Ana Lucia dos; Di Chiacchio, Nilton; Belda Junior, Walter

    2015-01-01

    Mycological examination is still the cornerstone for the diagnosis of onychomycosis for many dermatologists, but sampling technique interferes on its sensitivity and specificity. Nail abrasion may be used to reach the most proximal part of the lesion and can be easily accomplished with an electric abrasor. We suggest nail plate dermoscopy to identify the best location for localized abrasion to obtain adequate samples for mycological examination. PMID:26734877

  19. 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. PMID:24993884

  20. Computed tomography to quantify tooth abrasion

    NASA Astrophysics Data System (ADS)

    Kofmehl, Lukas; Schulz, Georg; Deyhle, Hans; Filippi, Andreas; Hotz, Gerhard; Berndt-Dagassan, Dorothea; Kramis, Simon; Beckmann, Felix; Müller, Bert

    2010-09-01

    Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology including root canal, dentin, and enamel volumes.

  1. 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.

  2. 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 process 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.

  3. A modified ASTM G-75 abrasion test helps select candidate alloys for service in a corrosive and abrasive slurry

    SciTech Connect

    Corbett, R.A.; Morrison, W.S.; Jenkins, C.F.; Westinghouse Savannah River Co., Aiken, SC )

    1989-01-01

    The design of a hazardous waste immobilization facility at the Savannah River Site (SRS) set material requirements for both abrasion resistance and corrosion resistance in process equipment. Standard ASTM slurry wear test G75 was modified to permit evaluation and comparison of abrasive resistance of candidate materials of construction in the laboratory. However, corrosion was found to contribute significantly to overall metal loss during the testing. Consequently, the abrasive slurry used for the testing was modified by adjusting its chemistry to include appropriate corrosive species. The Miller numbers obtained in the modified G75 Miller abrasion test are described. Pilot plant observations for Type 304L austenitic stainless steel were available. These data were used to generate a Morrison-Miller Ratio'' in order to determine anticipated field abrasion properties for other alloys. Hardness for many of the alloys fell in a narrow range about Rockwell B90, but performance varied significantly in response to slurry chemistry. This effect if synergistic may often be overlooked in the selection process, and it needs to be addressed. Some pilot plant testing of other alloys is essential to confirm the calculated abrasion rates and the approach of using the Morrison-Miller ratio. 6 refs., 3 figs., 5 tabs.

  4. Variation in Feeding Practices Following the Norwood Procedure

    PubMed Central

    Lambert, Linda M.; Pike, Nancy A.; Medoff-Cooper, Barbara; Zak, Victor; Pemberton, Victoria L.; Young-Borkowski, Lisa; Clabby, Martha L.; Nelson, Kathryn N.; Ohye, Richard G.; Trainor, Bethany; Uzark, Karen; Rudd, Nancy; Bannister, Louise; Korsin, Rosalind; Cooper, David S.; Pizarro, Christian; Zyblewski, Sinai C.; Bartle, Bronwyn H.; Williams, Richard V.

    2013-01-01

    Objectives To assess variation in feeding practice at Norwood discharge, factors associated with tube feeding, and associations between site, feeding mode, and growth prior to stage II. Study design From May 2005 to July 2008, 555 subjects from 15 centers were enrolled in the Pediatric Heart Network Single Ventricle Reconstruction Trial; 432 survivors with Norwood discharge feeding data were analyzed. Results Demographic and clinical variables were compared among 4 feeding modes: oral only (n=140), oral/tube (n=195), nasogastric tube (N-tube) only (n=40), and gastrostomy tube (G-tube) only (n=57). There was significant variation in feeding mode among sites (oral only 0–81% and G-tube only 0–56%, p<0.01). After adjusting for site, multivariable modeling showed G-tube feeding at discharge was associated with longer hospitalization, and N-tube feeding was associated with greater number of discharge medications (R2=0.65, p<0.01). After adjusting for site, mean pre-stage II weight-for-age z-score (WAZ) was significantly higher in the oral only group (−1.4) vs. the N-tube only (−2.2) and G-tube only (−2.1) groups (p=0.04 and 0.02, respectively). Conclusions Feeding mode at Norwood discharge varied among sites. Prolonged hospitalization and greater number of medications at the time of Norwood discharge were associated with tube feeding. Infants exclusively fed orally had a higher WAZ pre-stage II than those fed exclusively by tube. Exploring strategies to prevent morbidities and promote oral feeding in this highest risk population is warranted. PMID:24210923

  5. Weldability of an abrasion-resistant steel

    SciTech Connect

    Adonyi, Y.; Domis, W.F.; Chen, C.C.

    1995-12-31

    The welding performance of a low-carbon-equivalent, abrasion-resistant steel newly developed for the mining industry was studied using a combination of simulative and actual weldability tests. The susceptibility to hydrogen-induced cracking in the weld-metal and heat-affected zones (HAZ), as well as the potential loss of strength and toughness in the HAZ, were evaluated. Simulative testing included the use of the Gleeble 1500 thermomechanical simulator to produce single and multiple-pass weld HAZ microstructures on CVN-size specimens. The effects of heat input, interpass temperature, and post-weld heat treatment (PWHT) on the HAZ microstructure and properties were determined. Additionally, a computer software was used to predict theoretical HAZ hardnesses and volume fraction of phases as a function of cooling rates. The actual welding tests included the Gapped Bead-on-Plate and the Y-groove tests to determine the weld-metal and HAZ susceptibility to hydrogen-induced cracking. Three heat inputs, two diffusible hydrogen and two weld-metal yield-strength levels were used for the actual welding stage. Good correlation was found between microstructure predictions, physical simulations, and actual weld testing results. The new steel was found to be highly weldable because of the low preheat required to avoid HAZ hydrogen induced cracking. All aspects of weld-metal and HAZ cracking behavior had to be addressed for a complete weldability characterization. It was also found that use of excessive heat inputs and PWHT should be avoided when welding this type of steels.

  6. Hybrid endotracheal tubes

    NASA Astrophysics Data System (ADS)

    Sakezles, Christopher Thomas

    Intubation involves the placement of a tube into the tracheal lumen and is prescribed in any setting in which the airway must be stabilized or the patient anesthetized. The purpose of the endotracheal tube in these procedures is to maintain a viable airway, facilitate mechanical ventilation, allow the administration of anesthetics, and prevent the reflux of vomitus into the lungs. In order to satisfy these requirements a nearly airtight seal must be maintained between the tube and the tracheal lining. Most conventional endotracheal tubes provide this seal by employing a cuff that is inflated once the tube is in place. However, the design of this cuff and properties of the material are a source of irritation and injury to the tracheal tissues. In fact, the complication rate for endotracheal intubation is reported to be between 10 and 60%, with manifestations ranging from severe sore throat to erosion through the tracheal wall. These complications are caused by a combination of the materials employed and the forces exerted by the cuff on the tracheal tissues. In particular, the abrasive action of the cuff shears cells from the lining, epithelium adhering to the cuff is removed during extubation, and normal forces exerted on the basement tissues disrupt the blood supply and cause pressure necrosis. The complications associated with tracheal intubation may be reduced or eliminated by employing airway devices constructed from hydrogel materials. Hydrogels are a class of crosslinked polymers which swell in the presence of moisture, and may contain more than 95% water by weight. For the current study, several prototype airway devices were constructed from hydrogel materials including poly(vinyl alcohol), poly(hydroxyethyl methacrylate), and poly(vinyl pyrrolidone). The raw hydrogel materials from this group were subjected to tensile, swelling, and biocompatibility testing, while the finished devices were subjected to extensive mechanical simulation and animal trials

  7. 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. PMID:26016095

  8. 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.

  9. Abrasive tip treatment for use on compressor blades

    NASA Technical Reports Server (NTRS)

    Pedersen, H. C.

    1984-01-01

    A co-spray process was used which simultaneously but separately introduces abrasive grits and metal matrix powder into the plasma stream and entraps the abrasive grits within a molten matrix to form an abrasive coating as the matrix material solidifies on test specimen surfaces. Spray trials were conducted to optimize spray parameter settings for the various matrix/grit combinations before actual spraying of the test specimens. Rub, erosion, and bond adhesion tests were conducted on the coated specimens in the as-sprayed condition as well as on coated specimens that were aged for 100 hours at a temperature of 866K (1100 F). Microscopic examinations were performed to determine the coating abrasive-particle content, the size and shape of the adhesive particles in the coating, and the extent of compositional or morphological changes resulting from the aging process. A nickel chromium/aluminum composite with No. 150 size (0.002 to 0.005 inch) silicon carbide grits was selected as the best matrix/abrasive combination of the candidates surveyed for coating compressor blade tips.

  10. 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.

  11. Review of scratch test studies of abrasion mechanisms

    SciTech Connect

    Kosel, T.H.

    1986-01-01

    The use of scratch tests to simulate the material removal mechanisms which occur during abrasion is reviewed. Although useful studies of the effect of the rake angle on material removal have been carried out using diamond tools, closer simulation of the mechanisms of material removal can be obtained using actual irregular individual abrasive particles as scratch tools. Previous studies are reviewed in which scratch tests have been performed with both conventional scratch test instruments and a specially designed system used for )ital in situ) scratch tests in the scanning electron microscope (SEM). Multiple-pass scratch tests over the same scratch path have been shown to create surface features and wear debris particles which are very similar to those produced by low-stress abrasion. Alumina (Al/sub 2/O/sub 3/) particles have been shown to produce continuous micromachining chips from the hard, brittle carbide phase of Stellite alloys, establishing direct cutting as the important mechanism of material removal for this type of abrasive. An )ital in situ) study of material removal from white cast irons by quartz particles has provided conclusive evidence that carbide removal does not occur by direct cutting but rather always involves microfracture. Previously unpublished work which has compared scratch tests with crushed quartz and alumina particles is included. Also described is a new scratch test system which controls the depth of cut rather than the scratch load in order to simulate high-stress abrasion, in which abrasive particles are constrained to a fixed depth of cut. Preliminary new results show substantially different carbide fracture behavior under fixed-depth conditions. 8 figs., 20 refs.

  12. Aeolian Abrasion, a Dominant Erosion Agent in the Martian Environment

    NASA Astrophysics Data System (ADS)

    Bridges, N.; Cooper, G.; Eddlemon, E.; Greeley, R.; Laity, J.; Phoreman, J.; Razdan, A.; van Note, S.; White, B.; Wilson, G.

    2004-12-01

    Aeolian abrasion is one of the predominant erosion mechanisms on Mars today. Martian ventifacts record the climate under which the rocks were modified (wind direction, wind speeds and particle flux) and therefore tie into the overall climatic regime of the planet. By better understanding the rates at which rocks abrade and the features diagnostic of specific climatic conditions, we can gain insight into past climates. Herein we report on numerical models, wind tunnel experiments, and field work to determine 1) Particle and kinetic fluxes on Earth and Mars, 2) the degree to which these parameters control abrasion, and 3) how, in detail, rocks of various shapes and compositions erode over time. Kinetic energy generally increases with height, whereas flux decreases, and impact angles, which affect energy transfer, and rebound effects are functions of the rock facet angle. This results in a non-linear relationship between abrasion potential and height that is a function of wind speed, planetary environment, and target geometry. We have computed the first three of these parameters numerically using a numerical saltation code, combined with published flux calculations These results have been compared to wind tunnel tests of flux vs. height, abrasion of erodible targets, and high speed video analysis under terrestrial and Martian pressures. We are also using high resolution laser scanning to characterize textures, shapes, and weathering changes for terrestrial and Martian rocks at the 100s of microns scale. We find that facet angle, texture, and rock heterogeneity are of critical importance in determining the rate and style of abrasion. Field and theoretical results demonstrate that high speed winds, not the integrated flux of lower speeds, and sand, not dust, produce most rock abrasion. On Mars, this requires sustained winds above 20-25 m/s at the near surface, a challenge in the current environment.

  13. Dental abrasion pattern in a selected group of Malaysians.

    PubMed

    Yaacob, H B; Park, A W

    1990-09-01

    Among 350 inhabitants of two villages, 31 (8.9%) cleaned their teeth using table salt and charcoal applied to their forefinger or a Melastoma brush. As a result, all had distinct forms of abrasion cavity on the labial surfaces of their teeth. All of the above three agents are highly abrasive and injurious to both the hard and soft oral tissues. This dying practice is only popular among a very small number of persons in the older age group, and should be discouraged. PMID:2230960

  14. 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

  15. 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

  16. Abrasion cross sections for Ne-20 projectiles at 2.1 GeV/nucleon

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.

    1983-01-01

    Utilizing eikonal scattering theory, an optical model potential approximation to the exact nucleus-nucleus multiple scattering series is used in an abrasion-ablation collision formalism to predict abrasion cross sections for relativistic Ne-20 projectile nuclei. Excellent agreement with recent experimental abrasion results is obtained. The sensitivity of the abrasion predictions to Pauli exclusion principle correlation effects and to the assumed shape of the nuclear single-particle density distribution is also demonstrated.

  17. Development of a thermal reclamation system for spent blasting abrasive

    SciTech Connect

    Bryan, B.B.; Mensinger, M.C.; Rehmat, A.G.

    1991-01-01

    Abrasive blasting is the most economical method for paint removal from large surface areas such as the hulls and tanks of oceangoing vessels. Tens of thousands of tons of spent abrasive are generated annually by blasting operations in private and US Navy shipyards. Some of this material is classified as hazardous waste, and nearly all of it is currently being either stockpiled or disposed in landfills. The rapid decline in available landfill space and corresponding rise in landfill tipping fees pose a severe problem for shipyard operators throughout the US. This paper discusses the results of a research and development program initiated by the Institute of Gas Technology and supported by the US Navy to develop and test a fluidized-bed thermal reclamation system for spent abrasive waste minimization. Bench- and pilot-scale reclaimer tests and reclaimed abrasive performance tests are described along with the current status of a program to build and test a 5-ton/hour prototype reclaimer at a US Navy shipyard.

  18. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... wheel in motion. (5) Excluded machinery. Natural sandstone wheels and metal, wooden, cloth, or paper... apply to natural sandstone wheels or metal, wooden, cloth, or paper discs, having a layer of abrasive on... and Type 27A cutting-off wheels. (g) Certain internal wheels. (h) Type 4 tapered wheels. (i)...

  19. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... wheel in motion. (5) Excluded machinery. Natural sandstone wheels and metal, wooden, cloth, or paper... apply to natural sandstone wheels or metal, wooden, cloth, or paper discs, having a layer of abrasive on... and Type 27A cutting-off wheels. (g) Certain internal wheels. (h) Type 4 tapered wheels. (i)...

  20. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... spindle speed at safe levels under all conditions of normal operation. (b) Guarding. (1) Grinding machines.... (1) Floor stand and bench mounted abrasive wheels, used for external grinding, shall be provided with safety guards (protection hoods). The maximum angular exposure of the grinding wheel periphery and...

  1. A nonmineralized approach to abrasion-resistant biomaterials

    PubMed Central

    Pontin, Michael G.; Moses, Dana N.; Waite, J. Herbert; Zok, Frank W.

    2007-01-01

    The tooth-like mouthparts of some animals consist of biomacromolecular scaffolds with few mineral components, making them intriguing paradigms of biostructural materials. In this study, the abrasion resistance of the jaws of one such animal, the bloodworm Glycera dibranchiata, has been evaluated by nanoindentation, nanoscratching, and wear testing. The hardest, stiffest, and most abrasion-resistant materials are found within a thin (<3 μm) surface layer near the jaw tip and a thicker (10–20 μm) subsurface layer, both rich in unmineralized Cu. These results are consistent with the supposition that Cu ions are involved in the formation of intermolecular coordination complexes between proteins, creating a highly cross-linked molecular network. The intervening layer contains aligned atacamite [Cu2(OH)3Cl] fibers and exhibits hardness and stiffness (transverse to the alignment direction) that are only slightly higher than those of the bulk material but lower than those of the two Cu-rich layers. Furthermore, the atacamite-containing layer is the least abrasion-resistant, by a factor of ≈3, even relative to the bulk material. These observations are broadly consistent with the behavior of engineering polymer composites with hard fiber or particulate reinforcements. The alignment of fibers parallel to the jaw surface, and the fiber proximity to the surface, are both suggestive of a natural adaptation to enhance bending stiffness and strength rather than to endow the surface regions with enhanced abrasion resistance. PMID:17702868

  2. Surface carbonization of titanium for abrasion-resistant implant materials.

    PubMed

    Zhu, Yuhe; Watari, Fumio

    2007-03-01

    Carbide layer was formed on the surface of Ti by heating in hydrocarbon atmosphere (benzene C6H6) at 1000-1400 degrees C using a high frequency induction heating method. Physical and mechanical properties of carbide-coated Ti were investigated to examine its potential as an abrasion-resistant implant material. Scanning electron microscopy (SEM) showed that the surface of Ti was covered with fine grains of 1-4 microm diameter, depending on heating conditions. In addition, carbide layer of about 1-25 microm thickness was observed on the cross-section of specimens by SEM and energy dispersive spectroscopy. Vickers hardness of surface carbide was found to be more than 2000. Further, Martens scratch test and ultrasonic scaler abrasion test showed that the indentation depth and width of carbide-coated Ti were much smaller than pure Ti, thereby confirming its high abrasion resistance. These results showed that for Ti implant materials that require high abrasion resistance, such as the abutment for dental implants, surface carbide coatings would be an effective means to improve their wear properties. PMID:17621941

  3. Potential of Air-Propelled Abrasives for Selective Weed Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel forms of selective weed control are needed by many types of growers, but especially organic growers who are restricted from using synthetic herbicides. Abrasive grit made from corn cobs was expelled from a sand blaster at 517 kPa pressure and aimed at seedlings of common lambsquarters and corn...

  4. Abrasive blasting agents: designing studies to evaluate relative risk.

    PubMed

    Hubbs, Ann; Greskevitch, Mark; Kuempel, Eileen; Suarez, Fernando; Toraason, Mark

    Workers exposed to respirable crystalline silica used in abrasive blasting are at increased risk of developing a debilitating and often fatal fibrotic lung disease called silicosis. The National Institute for Occupational Safety and Health (NIOSH) recommends that silica sand be prohibited as abrasive blasting material and that less hazardous materials be used in blasting operations. However, data are needed on the relative risks associated with exposure to abrasive blasting materials other than silica. NIOSH has completed acute studies in rats (Hubbs et al., 2001; Porter et al., 2002). To provide dose-response data applicable to making recommendation for occupational exposure limits, NIOSH has collaborated with the National Toxicology Program (NTP) to design longer term studies with silica substitutes. For risk assessment purposes, selected doses will include concentrations that are relevant to human exposures. Rat lung burdens achieved should be comparable to those estimated in humans with working lifetime exposures, even if this results in "overloading" doses in rats. To quantify both dose and response, retained particle burdens in the lungs and lung-associated lymph nodes will be measured, as well as biochemical and pathological indices of pulmonary response. This design will facilitate assessment of the pulmonary fibrogenic potential of inhaled abrasive blasting agents at occupationally relevant concentrations. PMID:16020188

  5. 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.

  6. Rhinosinusitis; A Potential Hazard of Nasogastric Tube Insertion

    PubMed Central

    Adeyemo, Adebolajo A.; Fasunla, Ayotunde J.; Adeosun, Aderemi A.; Abdullahi, Hamisu

    2007-01-01

    The nasogastric tube has been used frequently for enteral feeding and as an intranasal oxygen catheter. This practice is however associated with complications. We present a case of rhinosinusitis and sepsis in a diabetic patient following the insertion of a nasogastric tube. Physicians should be aware of sinusitis as a possible cause of sepsis in patients with nasogastric tube insertion. PMID:25161433

  7. Ear tube insertion

    MedlinePlus

    Myringotomy; Tympanostomy; Ear tube surgery; Pressure equalization tubes; Ventilating tubes; Ear infection - tubes; Otitis - tubes ... trapped fluid can flow out of the middle ear. This prevents hearing loss and reduces the risk ...

  8. 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.

  9. 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.

  10. 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.

  11. Abrasive Wear Study of NiCrFeSiB Flame Sprayed Coating

    NASA Astrophysics Data System (ADS)

    Sharma, Satpal

    2013-10-01

    In the present study, abrasive wear behavior of NiCrFeSiB alloy coating on carbon steel was investigated. The NiCrFeSiB coating powder was deposited by flame spraying process. The microstructure, porosity and hardness of the coatings were evaluated. Elemental mapping was carried out in order to study the distribution of various elements in the coating. The abrasive wear behavior of these coatings was investigated under three normal loads (5, 10 and 15 N) and two abrasive grit sizes (120 and 320 grit). The abrasive wear rate was found to increase with the increase of load and abrasive size. The abrasive wear resistance of coating was found to be 2-3 times as compared to the substrate. Analysis of the scanning electron microscope images revealed cutting and plowing as the material removal mechanisms in these coatings under abrasive wear conditions used in this investigation.

  12. 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.

  13. Abrasion Testing of Critical Components of Hydrokinetic Devices

    SciTech Connect

    Worthington, Monty; Ali, Muhammad; Ravens, Tom

    2013-12-06

    The objective of the Abrasion Testing of Critical Components of Hydrokinetic Devices (Project) was to test critical components of hydrokinetic devices in waters with high levels of suspended sediment – information that is widely applicable to the hydrokinetic industry. Tidal and river sites in Alaska typically have high suspended sediment concentrations. High suspended sediment also occurs in major rivers and estuaries throughout the world and throughout high latitude locations where glacial inputs introduce silt into water bodies. In assessing the vulnerability of technology components to sediment induced abrasion, one of the greatest concerns is the impact that the sediment may have on device components such as bearings and seals, failures of which could lead to both efficiency loss and catastrophic system failures.

  14. Nanometric Finishing on Biomedical Implants by Abrasive Flow Finishing

    NASA Astrophysics Data System (ADS)

    Subramanian, Kavithaa Thirumalai; Balashanmugam, Natchimuthu; Shashi Kumar, Panaghra Veeraiah

    2016-01-01

    Abrasive flow finishing (AFF) is a non-conventional finishing technique that offers better accuracy, efficiency, consistency, economy in finishing of complex/difficult to machine materials/components and provides the possibility of effective automation as aspired by the manufacturing sector. The present study describes the finishing of a hip joint made of ASTM grade Co-Cr alloy by Abrasive Flow Machining (AFM) process. The major input parameters of the AFF process were optimized for achieving nanometric finishing of the component. The roughness average (Ra) values were recorded during experimentation using surface roughness tester and the results are discussed in detail. The surface finished hip joints were characterized using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and residual stress analysis using X-Ray Diffraction (XRD). The discussion lays emphasis on the significance, efficacy and versatile nature of the AFF process in finishing of bio-medical implants.

  15. Microstructure and abrasive wear in silicon nitride ceramics

    SciTech Connect

    Dogan, Cynthia P.; Hawk, Jeffrey A.

    2001-10-01

    It is well known that abrasive wear resistance is not strictly a materials property, but also depends upon the specific conditions of the wear environment. Nonetheless, characteristics of the ceramic microstructure do influence its hardness and fracture toughness and must, therefore, play an active role in determining howa ceramic will respond to the specific stress states imposed upon it by the wear environment. In this study, the ways in which composition and microstructure influence the abrasive wear behavior of six commercially-produced silicon nitride based ceramics are examined. Results indicate that microstructural parameters, such as matrix grain size and orientation, porosity, and grain boundary microstructure, and thermal expansion mismatch stresses created as the result of second phase formation, influence the wear rate through their effect on wear sheet formation and subsurface fracture. It is also noted that the potential impact of these variables on the wear rate may not be reflected in conventional fracture toughness measurements.

  16. A physically-based abrasive wear model for composite materials

    SciTech Connect

    Lee, Gun Y.; Dharan, C.K.H.; Ritchie, Robert O.

    2001-05-01

    A simple physically-based model for the abrasive wear of composite materials is presented based on the mechanics and mechanisms associated with sliding wear in soft (ductile) matrix composites containing hard (brittle) reinforcement particles. The model is based on the assumption that any portion of the reinforcement that is removed as wear debris cannot contribute to the wear resistance of the matrix material. The size of this non-contributing portion of the reinforcement is estimated by modeling the three primary wear mechanisms, specifically plowing, interfacial cracking and particle removal. Critical variables describing the role of the reinforcement, such as its relative size and the nature of the matrix/reinforcement interface, are characterized by a single contribution coefficient, C. Predictions are compared with the results of experimental two-body (pin-on drum) abrasive wear tests performed on a model aluminum particulate-reinforced epoxy matrix composite material.

  17. 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

  18. Wear and abrasion resistance selection maps of biological materials.

    PubMed

    Amini, Shahrouz; Miserez, Ali

    2013-08-01

    The mechanical design of biological materials has generated widespread interest in recent years, providing many insights into their intriguing structure-property relationships. A critical characteristic of load-bearing materials, which is central to the survival of many species, is their wear and abrasion tolerance. In order to be fully functional, protective armors, dentitious structures and dynamic appendages must be able to tolerate repetitive contact loads without significant loss of materials or internal damage. However, very little is known about this tribological performance. Using a contact mechanics framework, we have constructed materials selection charts that provide general predictions about the wear performance of biological materials as a function of their fundamental mechanical properties. One key assumption in constructing these selection charts is that abrasion tolerance is governed by the first irreversible damage at the contact point. The maps were generated using comprehensive data from the literature and encompass a wide range of materials, from heavily mineralized to fully organic materials. Our analysis shows that the tolerance of biological materials against abrasion depends on contact geometry, which is ultimately correlated to environmental and selective pressures. Comparisons with experimental data from nanoindentation experiments are also drawn in order to verify our predictions. With the increasing amount of data available for biological materials also comes the challenge of selecting relevant model systems for bioinspired materials engineering. We suggest that these maps will be able to guide this selection by providing an overview of biological materials that are predicted to exhibit the best abrasion tolerance, which is of fundamental interest for a wide range of applications, for instance in restorative implants and protective devices. PMID:23643608

  19. Raising the resistance of mainline pump parts to hydraulic abrasion

    SciTech Connect

    Belousov, V.Ya.; Borisenko, V.V.; Zhuravlev, Yu.V.

    1988-01-01

    The authors investigate the diffusion coating of mainline petroleum pump surfaces with boron carbides and the subsequent hardness and abrasion resistance of the working surfaces based on the temperature of the treatment and the depth and concentration of the coating. Industrial testing on an NM 2500 x 230 centrifugal pump demonstrated an increase in service life by a factor of 2 to 2.5. The process has been put into production at an annual savings per pump of 4000 rubles.

  20. Mass flow rate measurement in abrasive jets using acoustic emission

    NASA Astrophysics Data System (ADS)

    Ivantsiv, V.; Spelt, J. K.; Papini, M.

    2009-09-01

    The repeatability of abrasive jet machining operations is presently limited by fluctuations in the mass flow rate due to powder compaction, stratification and humidity effects. It was found that the abrasive mass flow rate for a typical abrasive jet micromachining setup could be determined by using data from the acoustic emission of the abrasive jet impacting a flat plate. Two methods for extracting the mass flow rate from the acoustic emission were developed and compared. In the first method, the number of particle impacts per unit time was determined by a direct count of peaks in the acoustic emission signal. The second method utilizes the power spectrum density of the acoustic emission in a specific frequency range. Both measures were found to correlate strongly with the mass flow rate measured by weighing samples of blasted powder for controlled time periods. It was found that the peak count method permits measurement of the average frequency of the impacts and the mass flow rate, but can only be applied to flow rates in which the impact frequency is approximately one order of magnitude less than the frequency of the target plate ringing. The power spectrum density method of signal processing is applicable to relatively fine powders and to flow rates at which the average impact frequency is of the same order of magnitude as that of the ringing due to the impact. The acoustic emission technique can be used to monitor particle flow variations over a wide range of time periods and provides a straightforward and accurate means of process control.

  1. 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(Registered TradeMark), Vectran(Registered TradeMark), Orthofabric, and Tyvek(Registered TradeMark)) that are candidates for advanced spacesuits. Three of the four new candidate fabrics (all but Vectran(Registered TradeMark)) were effective at keeping the dust from penetrating to layers beneath. In the cases of Kevlar(Registered TradeMark) 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(Registered TradeMark). 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(Registered TradeMark) and Kevlar(Registered TradeMark) suffering considerably more extensive filament breakage.

  2. Abrasion of eroded root dentine brushed with different toothpastes.

    PubMed

    De Menezes, Márcio; Turssi, Cecilia Pedroso; Hara, Anderson Takeo; Messias, Danielle Cristine Furtado; Serra, Mônica Campos

    2004-09-01

    This study evaluated the surface roughness change and wear provided by different dentifrices on root dentine previously exposed to erosive challenges. According to a randomized complete block design, 150 slabs of bovine root dentine (6 x 3 x 2 mm) were ground flat and polished. In an area of 4 x 3 mm on the dentine surface, specimens were submitted to five erosive/abrasive events, each one composed by: exposure to Sprite Diet or distilled water for 5 min, then to a remineralizing solution for 1 min, and simulation of 5,000 brushing strokes. Four dentifrices--regular (RE), baking soda (BS), whitening (WT) and tartar control (TC)--and distilled water (CO), used as control, were compared. Final texture and the wear depth were evaluated using a profilometer. ANOVA did not show significant interaction, indicating that the effect of dentifrices on both surface roughness change and wear did not depend on whether or not the dentine was eroded ( p>0.05). There was no difference between abrasion of eroded and sound dentine. The Tukey's test revealed that WT, BS and TC provided the highest increase in surface roughness differing from RE and CO. TC yielded the deepest wear of root dentine, whereas RE and CO, the shallowest. No significant difference in wear among BS, TC and WT were observed. Within the limitations of this study, the data showed that abrasion of both eroded and sound root dentine was dependent on the dentifrice used. PMID:15146320

  3. Shotcup petal abrasions in close range .410-caliber shotgun injuries.

    PubMed

    Dowling, G P; Dickinson, J A; Cooke, C T

    1988-01-01

    Shotcup petal abrasions centered around a shotgun wound of entrance are generally thought to occur at a range of 30 to 90 cm. A suicidal .410-caliber shotgun injury of the right eye is described in which typical petal abrasions were noted around the entrance wound. However, significant soot deposition around the wound suggested that the range of fire was less than 30 cm and perhaps closer to 15 cm. Test-firing of the weapon and ammunition used by the decedent showed some spread of the shotcup petals at a range of 7.5 cm, progressing to maximum spread at 30 to 52.5 cm. Further testing with other .410 ammunition, containing shotcups, confirmed the spread of shotcup petals at ranges less than 30 cm, irrespective of manufacturer, shotshell length, and birdshot size. When a variety of shotguns were tested, it was found that one weapon with a very short barrel and cylinder bore did not exhibit petal spread until a range of 30 cm was reached. The remaining shotguns, with longer barrels and full choke, all demonstrated definite petal spread at a range of 12.5 cm. The long, narrow configuration of .410 shotcup petals may explain their early spread and the production of petal abrasions at ranges of less than 30 cm. PMID:3351464

  4. Angular glass tubing drawn from round tubing

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Round glass tubing softened in a furnace is drawn over a shaped plug or mandel to form shapes with other than a circular cross section. Irregularly shaped tubing is formed without limitations on tube length or wall thickness.

  5. Comparing the Air Abrasion Cutting Efficacy of Dentine Using a Fluoride-Containing Bioactive Glass versus an Alumina Abrasive: An In Vitro Study.

    PubMed

    Tan, Melissa H X; Hill, Robert G; Anderson, Paul

    2015-01-01

    Air abrasion as a caries removal technique is less aggressive than conventional techniques and is compatible for use with adhesive restorative materials. Alumina, while being currently the most common abrasive used for cutting, has controversial health and safety issues and no remineralisation properties. The alternative, a bioactive glass, 45S5, has the advantage of promoting hard tissue remineralisation. However, 45S5 is slow as a cutting abrasive and lacks fluoride in its formulation. The aim of this study was to compare the cutting efficacy of dentine using a customised fluoride-containing bioactive glass Na0SR (38-80 μm) versus the conventional alumina abrasive (29 μm) in an air abrasion set-up. Fluoride was incorporated into Na0SR to enhance its remineralisation properties while strontium was included to increase its radiopacity. Powder outflow rate was recorded prior to the cutting tests. Principal air abrasion cutting tests were carried out on pristine ivory dentine. The abrasion depths were quantified and compared using X-ray microtomography. Na0SR was found to create deeper cavities than alumina (p < 0.05) despite its lower powder outflow rate and predictably reduced hardness. The sharper edges of the Na0SR glass particles might improve the cutting efficiency. In conclusion, Na0SR was more efficacious than alumina for air abrasion cutting of dentine. PMID:26697067

  6. Comparing the Air Abrasion Cutting Efficacy of Dentine Using a Fluoride-Containing Bioactive Glass versus an Alumina Abrasive: An In Vitro Study

    PubMed Central

    Tan, Melissa H. X.; Hill, Robert G.; Anderson, Paul

    2015-01-01

    Air abrasion as a caries removal technique is less aggressive than conventional techniques and is compatible for use with adhesive restorative materials. Alumina, while being currently the most common abrasive used for cutting, has controversial health and safety issues and no remineralisation properties. The alternative, a bioactive glass, 45S5, has the advantage of promoting hard tissue remineralisation. However, 45S5 is slow as a cutting abrasive and lacks fluoride in its formulation. The aim of this study was to compare the cutting efficacy of dentine using a customised fluoride-containing bioactive glass Na0SR (38–80 μm) versus the conventional alumina abrasive (29 μm) in an air abrasion set-up. Fluoride was incorporated into Na0SR to enhance its remineralisation properties while strontium was included to increase its radiopacity. Powder outflow rate was recorded prior to the cutting tests. Principal air abrasion cutting tests were carried out on pristine ivory dentine. The abrasion depths were quantified and compared using X-ray microtomography. Na0SR was found to create deeper cavities than alumina (p < 0.05) despite its lower powder outflow rate and predictably reduced hardness. The sharper edges of the Na0SR glass particles might improve the cutting efficiency. In conclusion, Na0SR was more efficacious than alumina for air abrasion cutting of dentine. PMID:26697067

  7. Intermittent bolus feeding has a greater stimulatory effect on protein synthesis in skeletal muscle than continuous feeding in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Feeding by orogastric tube, using either continuous or intermittent bolus delivery, is common for infants for whom normal feeding is contraindicated. To determine the impact of different feeding modalities on muscle protein anabolism, neonatal pigs (5–7 day old) received a balanced enteral formula e...

  8. Intermittent bolus feeding has a greater stimulatory effect on protein synthesis in skeletal muscle than continuous feeding in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Orogastric tube feeding, using either continuous or intermittent bolus delivery, is common in infants for whom normal feeding is contraindicated. To compare the impact of different feeding strategies on muscle protein synthesis, after withholding food overnight, neonatal pigs received a complete for...

  9. Electron tube

    DOEpatents

    Suyama, Motohiro; Fukasawa, Atsuhito; Arisaka, Katsushi; Wang, Hanguo

    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.

  10. 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.

  11. Neutron tubes

    DOEpatents

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

    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.

  12. Baleen wear reveals intraoral water flow patterns of mysticete filter feeding.

    PubMed

    Werth, Alexander J; Straley, Janice M; Shadwick, Robert E

    2016-04-01

    A survey of macroscopic and microscopic wear patterns in the baleen of eight whale species (Cetacea: Mysticeti) discloses structural, functional, and life history properties of this neomorphic keratinous tissue, including evidence of intraoral water flow patterns involved in filter feeding. All baleen demonstrates wear, particularly on its medial and ventral edges, as flat outer layers of cortical keratin erode to reveal horn tubes, also of keratin, which emerge as hair-like fringes. This study quantified five additional categories of specific wear: pitting of plates, scratching of plates, scuffing of fringes, shortening of fringes, and reorientation of fringes (including fringes directed between plates to the exterior of the mouth). Blue whale baleen showed the most pitting and sei whale baleen the most scratching; gray whale baleen had the most fringe wear. The location of worn baleen within the mouth suggests that direct contact with the tongue is not responsible for most wear, and that flowing water as well as abrasive prey or sediment carried by the flowing water likely causes pitting and scratching of plates as well as fringe fraying, scuffing, shortening, and reorientation. Baleen also has elevated vertical and horizontal ridges that are unrelated to wear; these are probably related to growth and may allow for age determination. PMID:26825852

  13. Chest tube insertion

    MedlinePlus

    Chest drainage tube insertion; Insertion of tube into chest; Tube thoracostomy; Pericardial drain ... When your chest tube is inserted, you will lie on your side or sit partly upright, with one arm over your ...

  14. Inline evenflow material distributor for pneumatic material feed systems

    DOEpatents

    Thiry, Michael J.

    2007-02-20

    An apparatus for reducing clogs in a pneumatic material feed line, such as employed in abrasive waterjet machining systems, by providing an evenflow feed of material therethrough. The apparatus preferably includes a hollow housing defining a housing volume and having an inlet capable of connecting to an upstream portion of the pneumatic material feed line, an outlet capable of connecting to a downstream portion of the pneumatic material feed line, and an air vent located between the inlet and outlet for venting excess air pressure out from the housing volume. A diverter, i.e. an impingement object, is located at the inlet and in a path of incoming material from the upstream portion of the pneumatic material feed line, to break up clumps of ambient moisture-ridden material impinging on the diverter. And one or more filter screens is also preferably located in the housing volume to further break up clumps and provide filtering.

  15. The effect of hydrogen peroxide on polishing removal rate in CMP with various abrasives

    NASA Astrophysics Data System (ADS)

    Manivannan, R.; Ramanathan, S.

    2009-01-01

    The effect of hydrogen peroxide in chemical mechanical planarization slurries for shallow trench isolation was investigated. The various abrasives used in this study were ceria, silica, alumina, zirconia, titania, silicon carbide, and silicon nitride. Hydrogen peroxide suppresses the polishing of silicon dioxide and silicon nitride surfaces by ceria abrasives. The polishing performances of other abrasives were either unaffected or enhanced slightly with the addition of hydrogen peroxide. The ceria abrasives were treated with hydrogen peroxide, and the polishing of the work surfaces with the treated abrasive shows that the inhibiting action of hydrogen peroxide is reversible. It was found that the effect of hydrogen peroxide as an additive is a strong function of the nature of the abrasive particle.

  16. A Profilometric Study to Assess the Role of Toothbrush and Toothpaste in Abrasion Process

    PubMed Central

    Kumar, Sandeep; Kumar Singh, Siddharth; Gupta, Anjali; Roy, Sayak; Sareen, Mohit; Khajuria, Sarang

    2015-01-01

    Statement of the Problem Despite of many studies conducted on toothbrushes and toothpaste to find out the culprit for abrasion, there is no clear cut evidence to pin point the real cause for abrasion. Purpose An in vitro assessment of the role of different types of toothbrushes (soft/ medium/hard) in abrasion process when used in conjunction with and without a dentifrice. Materials and Method Forty five freshly extracted, sound, human incisor teeth were collected for this study. Enamel specimens of approximately 9 mm2 were prepared by gross trimming of extracted teeth using a lathe machine (Baldor 340 Dental lathe; Ohio, USA). They were mounted on separate acrylic bases. The specimens were divided into three groups, each group containing 15 mounted specimens. Group 1 specimens were brushed with soft toothbrush; Group 2 brushed with medium toothbrush and Group 3 with hard toothbrush. Initially, all the mounted specimens in each group were brushed using dentifrice and then the same procedure was repeated with water as control. Profilometric readings were recorded pre and post to tooth brushing and the differences in readings served as proxy measure to assess surface abrasion. These values were then compared to each other. Kruskal Wallis and Mann-Whitney U test were performed. Results The results showed that brushing, with water alone, caused less abrasion than when toothpaste was added (p< 0.008). When brushed with water, the harder toothbrush caused more abrasion (higher Ra-value), but when toothpaste was added, the softer toothbrush caused more abrasion (p< 0.001). Conclusion Besides supporting the fact that toothpaste is needed to create a significant abrasion, this study also showed that a softer toothbrush can cause more abrasion than harder ones. The flexibility of bristles is only secondary to abrasion process and abrasivity of dentifrice has an important role in abrasion process. PMID:26535407

  17. 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.

  18. Tube furnace

    SciTech Connect

    Foster, K.G.; Frohwein, E.J.; Taylor, R.W.; Bowen, D.W.

    1990-12-31

    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.

  19. Tube furnace

    SciTech Connect

    Foster, K.G.; Frohwein, E.J.; Taylor, R.W.; Bowen, D.W.

    1990-01-01

    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.

  20. Feeding guilt.

    PubMed

    Byrom, Anna

    2013-03-01

    Breastfeeding is increasingly equated to ideologies of the 'good mother' in our society in response to a growing body of evidence identifying its benefits. Women who choose not to or are unable to breastfeed can experience a sense of guilt in response to cultural expectations that 'breast is best'. These negative feelings can impact upon their adaptation to and enjoyment of motherhood. This discussion paper examines the experience of maternal guilt with specific reference to infant feeding. An exploration of the reasons mothers may feel guilty about their feeding experiences is offered. Finally some suggestions are made about how midwives and breastfeeding advocates might improve care for mothers' emotional wellbeing. PMID:23590082

  1. A comparison of the abrasiveness of six ceramic surfaces and gold.

    PubMed

    Jacobi, R; Shillingburg, H T; Duncanson, M G

    1991-09-01

    A type III gold alloy and six different ceramic surfaces were secured in an abrasion machine opposing extracted teeth to determine their relative abrasiveness and resistance to wear. The rankings of restorative materials from least abrasive to most abrasive were: gold alloy, polished; cast ceramic, polished; porcelain, polished; cast ceramic, polished and shaded; porcelain, polished and glazed; cast ceramic, cerammed skin shaded; and cast ceramic, cerammed skin unshaded. The ranking of materials from most wear-resistant to least wear-resistant was: gold alloy, cast ceramic cerammed, cast ceramic cerammed and shaded, porcelain polished, porcelain glazed, cast ceramic polished and shaded, and cast ceramic polished. PMID:1800724

  2. Collapse Tubes

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02154 Collapse Tubes

    The discontinuous channels in this image are collapsed lava tubes.

    Image information: VIS instrument. Latitude -19.7N, Longitude 317.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  3. 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.

  4. Abrasion in pyroclastic density currents: Insights from tumbling experiments

    NASA Astrophysics Data System (ADS)

    Kueppers, Ulrich; Putz, Constanze; Spieler, Oliver; Dingwell, Donald B.

    2012-01-01

    During granular mass movements of any kind, particles may interact with one another. The degree of interaction is a function of several variables including; grain-size distribution, particle concentration, density stratification and degree of fluidisation. The impact of particle interaction is additionally influenced by the relative speed, impact angle and clast temperature. Thus, both source conditions and transport-related processes are expected to influence the flow dynamics of pyroclastic density currents and their subsequent deposition. Here, we use tumbling experiments to shed light on the susceptibility of porous clasts to abrasion. We investigated the abrasion of unaltered volcanic rocks (5.7-80 vol.% porosity) from Unzen (Japan), Bezymianny (Russia) and Santorini (Greece) volcanoes as well as one synthetic analogue material, an insulating material with the trade name Foamglas® (95 vol.% porosity). Each experiment started with angular fragments generated in a jaw crusher from larger clasts. Two experimental series were performed; on samples with narrow and broader grain-size distributions, respectively. The dry samples were subject to rotational movement at constant speed and ambient temperature in a gum rotational tumbler for durations of 15, 30, 45, 60 and 120 min. The amount of volcanic ash (particles <2 mm) generated was evaluated as a function of experimental duration and sample porosity. We term “abrasion” as the ash fraction generated during the experiments. The observed increase of “abrasion” with increasing sample porosity and experimental duration is initially non-linear but becomes linear for experiments of 30 min duration or longer. For any given sample, abrasion appears to be more effective for coarser samples and larger initial mass. The observed range of ash generated in our experiments is between 1 and 35 wt.%. We find that this amount generally increases with increasing initial clast size or increasing breadth of the initial grain

  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. 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…

  7. 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.

  8. CAD/CAM-based Position/Force Control for a Ball-End Abrasive Tool and Its Application to an Industrial Robot

    NASA Astrophysics Data System (ADS)

    Nagata, Fusaomi; Hase, Tetsuo; Haga, Zenku; Omoto, Masaaki; Watanabe, Keigo

    Control of robotic mold polishing is considered in this paper. CAD/CAM-based position/force controller that simultaneously performs stable force control and exact pick feed control along curved surface is presented for articulated-type industrial robots. The force feedback loop controls the polishing force consisting of the contact force and the kinetic friction force. During mold polishing, the position feedback loop has a delicate contribution to the force feedback loop in Cartesian space so that the abrasive tool does not deviate from the desired trajectory but keeps a constant pick feed. When a mold polishing robot runs, cutter location (CL) data with normal vectors are used for not only a desired trajectory of tool translational motion but also desired contact directions given to a mold. The CL data allow the robot to realize a complete non-taught operation of the position and the contact direction. In this paper, a simple experiment is conducted by using an industrial robot with a ball-end abrasive tool in order to evaluate the effectiveness of the proposed method. The target workpiece is an aluminum PET bottle blow mold after NC machining, whose curved surface has small cusp marks with each pick feed of about 0.3 mm height. The results show that the proposed mold polishing robot with the CAD/CAM-based position/force controller can uniformly remove the cusp marks and further achieve mirror-like surface quality without undesirable over-polishing.

  9. Coke from small-diameter tubes analyzed

    SciTech Connect

    Albright, L.F.

    1988-08-29

    The mechanism for coke deposit formation and the nature of the coke itself can vary with the design of the ethylene furnace tube bank. In this article, coke deposits from furnaces with small-diameter pyrolysis tubes are examined. The samples were taken from four furnaces of identical design (Plant B). As in both the first and second installments of the series, the coke deposits were examined using a scanning electron microscope (SEM) and an energy dispersive X-ray analyzer (EDAX). The deposits from the small-diameter tubes are compared with the coke deposits from the furnace discussed in earlier articles. Analysis of the coke in both sets of samples are then used to offer recommendations for improved decoking procedures, operating procedures, better feed selection, and better selection of the metallurgy used in furnace tubes, to extend the operating time of the furnace tubes by reducing the amount and type of coke build up.

  10. Tube-in-tube thermophotovoltaic generator

    SciTech Connect

    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.

  11. 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.

  12. A tube-in-tube thermophotovoltaic generator

    SciTech Connect

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

    1996-12-31

    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.

  13. Effect of mechanical abrasion on the viability, disruption and germination of spores of Bacillus subtilis

    PubMed Central

    Jones, C.A.; Padula, N.L.; Setlow, P.

    2005-01-01

    Aims To elucidate the factors influencing the sensitivity of Bacillus subtilis spores to killing and disruption by mechanical abrasion, and the mechanism of stimulation of spore germination by abrasion. Methods and Results Spores of B. subtilis strains were abraded by shaking with glass beads in liquid or the dry state, and spore killing, disruption and germination were determined. Dormant spores were more resistant to killing and disruption by abrasion than were growing cells or germinated spores. However, dormant spores of the wild-type strain with or without most coat proteins removed, spores of strains with mutations causing spore coat defects, spores lacking their large depot of dipicolinic acid (DPA) and spores with defects in the germination process exhibited essentially identical rates of killing and disruption by abrasion. When spores lacking all nutrient germinant receptors were enumerated by plating directly on nutrient medium, abrasion increased the plating efficiency of these spores before killing them. Spores lacking all nutrient receptors and either of the two redundant cortex-lytic enzymes behaved similarly in this regard, but the plating efficiency of spores lacking both cortex-lytic enzymes was not stimulated by abrasion. Conclusions Dormant spores are more resistant to killing and disruption by abrasion than are growing cells or germinated spores, and neither the complete coats nor DPA are important in spore resistance to such treatments. Germination is not essential for spore killing by abrasion, although abrasion can trigger spore germination by activation of either of the spore’s cortex-lytic enzymes. Significance and Importance This work provides new insight into the mechanisms of the killing, disruption and germination of spores by abrasion and makes the surprising finding that at least much of the spore coat is not important in spore resistance to abrasion. PMID:16313421

  14. 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.

  15. Abrasion Resistant Coating and Method of making the same

    SciTech Connect

    Sordelet, Daniel J.; Besser, Matthew F.

    1999-06-25

    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.

  16. 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.

  17. 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.

  18. 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.

  19. Attrition and abrasion models for oil shale process modeling

    SciTech Connect

    Aldis, D.F.

    1991-10-25

    As oil shale is processed, fine particles, much smaller than the original shale are created. This process is called attrition or more accurately abrasion. In this paper, models of abrasion are presented for oil shale being processed in several unit operations. Two of these unit operations, a fluidized bed and a lift pipe are used in the Lawrence Livermore National Laboratory Hot-Recycle-Solid (HRS) process being developed for the above ground processing of oil shale. In two reports, studies were conducted on the attrition of oil shale in unit operations which are used in the HRS process. Carley reported results for attrition in a lift pipe for oil shale which had been pre-processed either by retorting or by retorting then burning. The second paper, by Taylor and Beavers, reported results for a fluidized bed processing of oil shale. Taylor and Beavers studied raw, retorted, and shale which had been retorted and then burned. In this paper, empirical models are derived, from the experimental studies conducted on oil shale for the process occurring in the HRS process. The derived models are presented along with comparisons with experimental results.

  20. Cotton Seedling Injury and Recovery from Wind Blown Sand Abrasion: I. Duration of Exposure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of acres of crops are exposed to wind blown sand abrasion injury each year and in many instances the damage is thought to be sufficiently severe to require replanting. The goal of this study was to determine the effects of wind blown sand abrasion duration on cotton seedlings. Seedlings of...

  1. Cutting Tools, Files and Abrasives. Pre-Apprenticeship Phase 1 Training.

    ERIC Educational Resources Information Center

    Lane Community Coll., Eugene, OR.

    This self-paced student training module on cutting tools, files, and abrasives is one of a number of modules developed for Pre-apprenticeship Phase 1 Training. Purpose of the module is to enable students to identify and explain the proper use and care of various knives, saws, snips, chisels, and abrasives. The module may contain some or all of the…

  2. 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

  3. Effect of canopy leaf distribution on sand transport and abrasion energy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During times when crop canopies are short or sparse, wind erosion can uncover plant roots, deplete the soil resource, and damage plants by abrasion and desiccation. Few studies have considered the effects of position and number of leaves on sand transport and the distribution of the sand abrasion en...

  4. Potential Use of Abrasive Air-Propelled Agricultural Residues for Weed Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new postemergence weed control tactic is proposed for organic production systems that results in plant abrasion and death upon assault from abrasive grits propelled by compressed air. Grit derived from granulated walnut shells was delivered by a sand blaster at 517 kPa at distances of 30 to 60 cm ...

  5. 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.

  6. 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.

  7. Hybrid organic/inorganic coatings for abrasion resistance on plastic and metal substrates

    SciTech Connect

    Wen, J.; Jordens, K.; Wilkes, G.L.

    1996-12-31

    Novel abrasion resistant coatings have been successfully prepared by the sol-gel method. These materials are spin coated onto bisphenol-A polycarbonate, diallyl diglycol carbonate resin (CR-39) sheet, aluminum, and steel substrates and are thermally cured to obtain a transparent coating of a few microns in thickness. Following the curing, the abrasion resistance is measured and compared with an uncoated control. It was found that these hybrid organic/inorganic networks partially afford excellent abrasion resistance to the polycarbonate substrates investigated. In addition to having excellent abrasion resistance comparable to current commercial coatings, some newly developed systems are also UV resistant. Similar coating formulations applied to metals can greatly improve the abrasion resistance despite the fact that the coatings are lower in density than their substrates.

  8. 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.

  9. A review of engineering control technology for exposures generated during abrasive blasting operations.

    PubMed

    Flynn, Michael R; Susi, Pam

    2004-10-01

    This literature review presents information on measures for controlling worker exposure to toxic airborne contaminants generated during abrasive blasting operations occurring primarily in the construction industry. The exposures of concern include respirable crystalline silica, lead, chromates, and other toxic metals. Unfortunately, silica sand continues to be widely used in the United States as an abrasive blasting medium, resulting in high exposures to operators and surrounding personnel. Recently, several alternative abrasives have emerged as potential substitutes for sand, but they seem to be underused Some of these abrasives may pose additional metal exposure hazards. In addition, several new and improved technologies offer promise for reducing or eliminating exposures; these include wet abrasive blasting, high-pressure water jetting, vacuum blasting, and automated/robotic systems. More research, particularly field studies, is needed to evaluate control interventions in this important and hazardous operation. PMID:15631059

  10. Tracheostomy tube - eating

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000464.htm Tracheostomy tube - eating To use the sharing features on ... when you swallow foods or liquids. Eating and Tracheostomy Tubes When you get your tracheostomy tube, or ...

  11. Design and performance of feed delivery systems for simulated radioactive waste slurries

    SciTech Connect

    Perez, J.M. Jr.

    1983-02-01

    Processes for vitrifying simulated high-level radioactive waste have been developed at the Pacific Northwest Laboratory (PNL) over the last several years. Paralleling this effort, several feed systems used to deliver the simulated waste slurry to the melter have been tested. Because there had been little industrial experience in delivering abrasive slurries at feed rates of less than 10 L/min, early experience helped direct the design of more-dependable systems. Also, as feed delivery requirements changed, the feed system was modified to meet these new requirements. The various feed systems discussed in this document are part of this evolutionary process, so they have not been ranked against each other. The four slurry feed systems discussed are: (1) vertical-cantilevered centrifugal pump system; (2) airlift feed systems; (3) pressurized-loop systems; and (4) positive-displacement pump system. 20 figures, 11 tables.

  12. Tube-shape verifier

    NASA Technical Reports Server (NTRS)

    Anderson, A. N.; Christ, C. R.

    1980-01-01

    Inexpensive apparatus checks accuracy of bent tubes. Assortment of slotted angles and clamps is bolted down to flat aluminum plate outlining shape of standard tube bent to desired configuration. Newly bent tubes are then checked against this outline. Because parts are bolted down, tubes can be checked very rapidly without disturbing outline. One verifier per tube-bending machine can really speed up production in tube-bending shop.

  13. 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)

  14. Feed Formulation and Manufacture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter provides information on feed formulation and manufacture. To formulate and manufacture high quality fish feeds, including tilapia feeds, one should have knowledge of nutrient requirements, nutrient composition, digestibility, and availability of feed ingredients; impacts of manufacturin...

  15. High grade abrasive product development from virtified industrial waste

    SciTech Connect

    Blume, R.D.; Drummond, C.H. III; Sarko, A.

    1996-12-31

    Recent developments in environmental legislation, as well as economic incentives such as the increasing cost of landfilling, have led to a paradigm shift away from encapsulation of hazardous waste. The current focus is recycling and product development utilizing industrial waste as raw materials. Current research has targeted the development of high grade abrasive (Vickers hardness (VHN) > 1000 kgF/mm{sup 2}) for blasting and buffing and polishing applications. In addition to product specific physical properties, the developed formulations must also have processing characteristics necessary for vitrification using a high temperature product burner developed by Seiler Pollution Control Systems, as well as the necessary resistance to leaching of EPA regulated hazardous components. Current work has led to the development of formulations with high VHN (950 kgF/mm{sup 2}), acceptable chemical durability, and high mechanical durability utilizing electric arc furnace dust (KO61) and foundry sand as the major components.

  16. 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.

  17. Fatigue Testing of Abrasive Water Jet Cut Titanium

    SciTech Connect

    Hovanski, Yuri; Dahl, Michael E.; Williford, Ralph E.

    2009-06-08

    Battelle Memorial Institute as part of its U.S. Department of Energy (USDOE) Contract No. DE-AC05-76RL01830 to operate the Pacific Northwest National Laboratory (PNNL) provides technology assistance to qualifying small businesses in association with a Technology Assistance Program (TAP). Qualifying companies are eligible to receive a set quantity of labor associated with specific technical assistance. Having applied for a TAP agreement to assist with fatigue characterization of Abrasive Water Jet (AWJ) cut titanium specimens, the OMAX Corporation was awarded TAP agreement 09-02. This program was specified to cover dynamic testing and analysis of fatigue specimens cut from titanium alloy Ti-6%Al-4%V via AWJ technologies. In association with the TAP agreement, a best effort agreement was made to characterize fatigue specimens based on test conditions supplied by OMAX.

  18. Microstructure and abrasion resistance of plasma sprayed titania coatings

    NASA Astrophysics Data System (ADS)

    Ctibor, P.; Neufuss, K.; Chraska, P.

    2006-12-01

    Agglomerated titania nanopowder and a “classical” titania were sprayed by the high throughput water-stabilized plasma (WSP) and thoroughly compared. Optical microscopy with image analysis as well as mercury intrusion porosimetry were used for quantification of porosity. Results indicate that the “nano” coatings in general exhibit finer pores than coatings of the “conventional” micron-sized powders. Mechanical properties such as Vickers microhardness and slurry abrasion response were measured and linked to the structural investigation. Impact of the variation in the slurry composition on wear resistance of tested coatings and on character of the wear damage is discussed. The overall results, however, suggest that the “nano” coatings properties are better only for carefully selected sets of spraying parameters, which seem to have a very important impact.

  19. Quantitative modeling of facet development in ventifacts by sand abrasion

    NASA Astrophysics Data System (ADS)

    Várkonyi, Péter L.; Laity, Julie E.; Domokos, Gábor

    2016-03-01

    We use a quantitative model to examine rock abrasion by direct impacts of sand grains. Two distinct mechanisms are uncovered (unidirectional and isotropic), which contribute to the macro-scale morphological characters (sharp edges and flat facets) of ventifacts. It is found that facet formation under conditions of a unidirectional wind relies on certain mechanical properties of the rock material, and we confirm the dominant role of this mechanism in the formation of large ventifacts. Nevertheless small ventifacts may also be shaped to polyhedral shapes in a different way (isotropic mechanism), which is not sensitive to wind characteristics nor to rock material properties. The latter mechanism leads to several 'mature' shapes, which are surprisingly analogous to the morphologies of typical small ventifacts. Our model is also able to explain certain quantitative laboratory and field observations, including quick decay of facet angles of ventifacts followed by stabilization in the range 20-30°.

  20. Cover and Erosion Asymmetry in Saltation-Abrasion

    NASA Astrophysics Data System (ADS)

    Stark, C. P.; Parker, G.

    2014-12-01

    Erosion in bedrock-floored rivers is both driven and limited by the amount of sediment transported along the bed. Some sediment boosts wear rates, whereas too much generates a protective cover. This phenomenon determines the shape of river channels in a variety of landscapes and limits how fast they evolve. Here we reevaluate data from a well-known bedrock wear experiment to throw new light on how the saltation-abrasion process. Instead of a symmetric form for erosion versus sediment flux relative to transport capacity, we find the erosion rate peak shifts towards lower sediment fluxes when blocking of oblique saltation trajectories is taken into account. The theoretical context for this reevaluation is a cover-saltation-abrasion model, based on queueing theory (QT), for bedload transport over a planar bedrock bed. The QT approach provides some clarity in the stochastic treatment of granular impacts and cover, and generates closed-form solutions for wear rate in terms of sediment flux and simplified saltation geometry. Applied to the Sklar & Dietrich (2001) experiments in a very small recirculating flume, the two-parameter QT model fits the observed relation between erosion rate and sediment load, infers sediment flux as a function of load, admits non-negligible wear rates for a mean sediment depth of one grain, i.e., for full cover on average, but also suggests that bedrock erosion is blocked at >=50% instantaneous cover. The QT model makes testable predictions for future laboratory experiments and highlights the need for specific improvements in more comprehensive treatments of bedrock erosion and cover.

  1. Tube entrance lens focus control

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

  2. Monitoring emissions from animal feeding operations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The EPA air consent agreement with animal feeding operations (AFO) specifies the use of EPA TO-15 for the speciation of VOCs emitted from these facilities. Sorbent tube sampling may be a more effective technique in the speciation of VOCs from AFOs due to its ability to capture both volatile and hig...

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    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.

  4. Quantitative characterization of agglomerate abrasion in a tumbling blender by using the Stokes number approach.

    PubMed

    Willemsz, Tofan A; Nguyen, Tien Thanh; Hooijmaijers, Ricardo; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees

    2013-03-01

    Removal of microcrystalline cellulose agglomerates in a dry-mixing system (lactose, 100 M) predominantly occurs via abrasion. The agglomerate abrasion rate potential is estimated by the Stokes abrasion (StAbr) number of the system. The StAbr number equals the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. Basically, the StAbr number concept describes the blending condition of the dry-mixing system. The concept has been applied to investigate the relevance of process parameters on agglomerate abrasion in tumbling blenders. Here, process parameters such as blender rotational speed and relative fill volumes were investigated. In this study, the StAbr approach revealed a transition point between abrasion rate behaviors. Below this transition point, a blending condition exists where agglomerate abrasion is dominated by the kinetic energy density of the powder blend. Above this transition point, a blending condition exists where agglomerates show (undesirable) slow abrasion rates. In this situation, the blending condition is mainly determined by the high fill volume of the filler. PMID:23250711

  5. Microstructural effects in abrasive wear. Third annual progress report, August 12, 1983-August 14, 1984

    SciTech Connect

    Kosel, T.H.

    1984-08-14

    The two major goals of the project are to improve our understanding of the mechanisms of carbide removal and of the role of matrix properties in abrasion. In the area of carbide removal mechanisms, progress this year has included completion of the fixed-depth scratch test apparatus and its use to demonstrate the occurrence of gross carbide cracking under fixed-depth conditions; comparable cracking does not occur under fixed-load conditions at a similar mean load. A high-stress abrasion system has been constructed and tested which will facilitate studies of abrasion under conditions similar to those produced by the fixed-depth scratch test system. Analysis of the work on the size effect in abrasion of dual-phase alloys has been completed. The largest single item in this year's proposed work in a study of the abrasion resistance and mechanisms of material removal in model alloys having second-phase particles (SPP's) with varying fracture properties. In the area of the effects of matrix properties on abrasion, the majority of the effort this year has centered on transmission electron microscopy of the subsurface deformation microstructures developed during abrasion.

  6. 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

  7. 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) 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.

  8. Linear abrasion of a titanium superhydrophobic surface prepared by ultrafast laser microtexturing

    NASA Astrophysics Data System (ADS)

    Steele, Adam; Nayak, Barada K.; Davis, Alexander; Gupta, Mool C.; Loth, Eric

    2013-11-01

    A novel method of fabricating titanium superhydrophobic surfaces by ultrafast laser irradiation is reported. The ultrafast laser irradiation creates self-organized microstructure superimposed with nano-scale roughness, after which a fluoropolymer coating is applied to lower the surface energy of the textured surface and achieve superhydrophobicity. The focus of this study is to investigate abrasion effects on this mechanically durable superhydrophobic surface. The mechanical durability is analyzed with linear abrasion testing and microscopy imaging. Linear abrasion tests indicate that these surfaces can resist complete microstructure failure up to 200 abrasion cycles and avoid droplet pinning up to ten abrasion cycles at 108.4 kPa applied pressure, which roughly corresponds to moderate to heavy sanding or rubbing in the presence of abrasive particles. The wear mechanisms are also investigated and the primary mechanism for this system is shown to be abrasive wear with fatigue by repeated plowing. Although these results demonstrate an advancement in mechanical durability over the majority of existing superhydrophobic surfaces, it exemplifies the challenge in creating superhydrophobic surfaces with suitable mechanical durability for harsh applications, even when using titanium.

  9. Influence of Corrosion on the Abrasion of Cutter Steels Used in TBM Tunnelling

    NASA Astrophysics Data System (ADS)

    Espallargas, N.; Jakobsen, P. D.; Langmaack, L.; Macias, F. J.

    2015-01-01

    Abrasion on tunnel boring machine (TBM) cutters may be critical in terms of project duration and costs. Several researchers are currently studying the degradation of TBM cutter tools used for excavating hard rock, soft ground and loose soil. So far, the primary focus of this research has been directed towards abrasive wear. Abrasive wear is a very common process in TBM excavation, but with a view to the environment in which the tools are working, corrosion may also exert an influence. This paper presents a selection of techniques that can be used to evaluate the influence of corrosion on abrasion on TBM excavation tools. It also presents the influence of corrosion on abrasive wear for some initial tests, with constant steel and geomaterial and varying properties of the excavation fluids (soil conditioners, anti-abrasion additives and water). The results indicate that the chloride content in the water media greatly influences the amount of wear, providing evidence of the influence of corrosion on the abrasion of the cutting tools. The presence of conditioning additives tailored to specific rock or soil conditions reduces wear. However, when chloride is present in the water, the additives minimise wear rates but fail to suppress corrosion of the cutting tools.

  10. EC Tube Fits

    SciTech Connect

    Kurita, C.H.; /Fermilab

    1987-03-03

    In the design of the EC, the beam tube, through which the beam line travels, can be found in the IH tube which is centrally located in the IH module. However, also between the beam tube and the IH tube lie both the vacuum and inner tubes of the vacuum and inner vessels. It is the vacuum between these vessels which provides insulation between the ambient beam tube and liquid argon in the cryostat. while the vacuum tube is supported along its length with the inner tube as best as possible, the inner tube will only be supported at the ends. The beam tube will also be end-supported, but it will be allowed to rest directly on the inner surface of the vacuum tube. It is required that the beam tube be able to slide in and out of the vacuum tube with relative ease in order that the EC's can be moved away from the CC when necessary (repair work, etc.). Although the frequency of such a move is not known, it is hoped to be low, and it would therefore be desirable, for cost reasons, to be able to use stock tubing for the vacuum and beam tubes instead of using specially machined tubing.

  11. Characterization and dispersion of pollutant releases from the abrasive blasting of lead paint from steel bridges

    SciTech Connect

    Lee, M.; Rana, B.

    1999-07-01

    The characterization of airborne and spent material for abrasive blasting of steel paint was performed as part of the Environmental Impact Statement for Lead Paint Removal Operations on New York City Department of Transportation Bridges1. Laboratory tests were performed on painted steel components of the Williamsburg Bridge, to determine the sizes of particles typically released into the air as aerosol and onto the ground as bulk material, as a result of accidental releases from abrasive blasting operations. Two of the most commonly used abrasives for paint removal on steel structures, recyclable steel grit and expendable abrasives were subjected to the laboratory tests. The results of the tests were used to determine the percentage of existing paint and abrasive which becomes airborne and the resultant particle size distributions, which were employed in the air quality concentration and deposition modeling for the EIS. Particle size distributions of the airborne material indicated that the profiles of airborne lead and particulate matter have a mean particle size between 15 and 21 microns. Spent abrasives and paint chips that settle on the floor are larger in size with a mean diameter greater than 259 microns, although up to 6% of this material has a mean diameter less than 50 microns. The percentage of paint and expendable abrasives that become airborne as a result of abrasive blasting were estimated to be as high as 9.0 and 12.4%, respectively. Potential release rates were derived for total accumulation (duration of the project), annual, quarterly, 24-hour, and 1-hour time averaging periods for abrasives, lead, and other metals. Pollutant releases were simulated as individual sources at multiple release heights with the Environment Protection Agency's ISC3ST model for six representative bridges near potential places of public exposure.

  12. 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.

  13. 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.

  14. Plasma-polymerized coating for polycarbonate: Single-layer, abrasion resistant, and antireflection

    NASA Technical Reports Server (NTRS)

    Wydeven, Theodore

    1991-01-01

    Plasma-polymerized vinyl trimethoxy silane films were deposited on transparent polycarbonate substrates. The adherent, clear films protected the substrates from abrasion and also served as antireflection coatings. Post-treatment of the vinyl trimethoxy silane films in an oxygen glow discharge further improved their abrasion resistance. The coatings were characterized by elemental analysis of the bulk, ESCA analysis of the surface, transmission, thickness, abrasion resistance, haze, and adhesion. This patented process is currently used by the world's largest manufacturers of non-prescription sunglasses to protect the plastic glasses from scratching and thereby to increase their useful lifetime.

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

    SciTech Connect

    Townsend, L.W.

    1981-07-01

    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.

  16. High Resolution Laser Scanning Techniques for Rock Abrasion and Texture Analyses on Mars and Earth

    NASA Technical Reports Server (NTRS)

    Bridges, N. T.; Razdan, A.; Greeley, R.; Laity, J. E.

    2004-01-01

    Aeolian abrasion is operative in many arid locations on Earth and is probably the dominant rock erosion process in the current Martian environment. Therefore, understanding the controlling parameters and rates of aeolian abrasion provides 1) insight into the stability of rocks on planetary surfaces and the environments under which the rocks abrade, and 2) a link between ventifact (a rock abraded by windblown particles) morphology and: a) abrasion conditions, b) possible ancient environments under which the rocks were abraded, and c) rock properties. promising and we plan further investigations in the wind tunnel and field. Our intent here is to discuss the basic technique, initial results, and upcoming plans.

  17. 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.

  18. 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

  19. Abrasive wear by coal-fueled diesel engine and related particles

    SciTech Connect

    Ives, L.K.

    1992-09-01

    The development of commercially viable diesel engines that operate directly on pulverized coal-fuels will require solution to the problem of severe abrasive wear. The purpose of the work described in this report was to investigate the nature of the abrasive wear problem. Analytical studies were carried out to determine the characteristics of the coal-fuel and associated combustion particles responsible for abrasion. Laboratory pinon-disk wear tests were conducted on oil-particle mixtures to determine the relationship between wear rate and a number of different particle characteristics, contact parameters, specimen materials properties, and other relevant variables.

  20. Immediate postoperative feeding in urological surgery.

    PubMed

    Seidmon, E J; Pizzimenti, K V; Blumenstock, F A; Huben, R P; Wajsman, Z; Pontes, J E

    1984-06-01

    The value of immediate postoperative enteral hyperalimentation with an elemental diet (high nitrogen Vivonex, full strength) at 125 cc per hour for 4 days was assessed in patients after radical urological surgery. Of 32 patients studied 21 received an elemental diet using a Vivonex Moss tube, which is a 3-lumen tube with esophagogastric decompression and simultaneous duodenal feeding, and the remaining 11 had a nasogastric tube only without nutritional support. We have used a selected group of parameters, including serum albumin, serum transferrin, creatinine height index, weight loss, total lymphocyte count, nitrogen balance and plasma fibronectin. All patients in the Moss tube group approached or achieved positive nitrogen balance by 4 days postoperatively, whereas the nasogastric tube group remained in negative nitrogen balance. Postoperative paralytic ileus was prevented in the majority of patients in the Moss tube group while receiving full nutritional support. We have found that the use of the Moss tube is a reasonable approach for postoperative alimentation. The tube is relatively easy to insert and well tolerated, and its use is a less expensive alternative to parenteral hyperalimentation. PMID:6427479

  1. Intestinal perforation management using T-tube drainage

    PubMed Central

    Wakahara, Tomoyuki; Kaji, Masahide; Harada, Yuko; Tsuchida, Shinobu; Toyokawa, Akihiro

    2016-01-01

    In cases of small bowel perforation with gross contamination, enterostomy has traditionally been the treatment of choice. An 86-year-old woman was diagnosed with perforative peritonitis. Emergency laparotomy revealed a small bowel perforation with gross contamination, and a T-tube enterostomy was performed. The T-tube was used for intestinal decompression for the first few days and was then accompanied by enteral feeding. When oral intake was sufficient, the T-tube was removed. The abdominal wall’s fistula healed within 2 days of removal. Except for wound infection, the patient developed no postoperative complications. Under specific circumstances, a T-tube enterostomy can be an effective alternative for a traditional enterostomy. Its advantages include less or no anastomotic leakage, easier management of fluid and electrolyte levels, postoperative enteral feeding from the tube, a shorter operative time and no need for a second operation to close the stoma. PMID:27177890

  2. 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

  3. Abrasive jet micro-machining of polymeric materials

    NASA Astrophysics Data System (ADS)

    Hailu, Getu

    In the abrasive jet micro-machining (AJM) process, a jet of small particles is directed through an erosion resistant mask opening so that micro-sized features (i.e., micro-channels, holes, etc.) can be machined for the fabrication of micro-devices such as micro-fluidic and micro-electro-mechanical-systems (MEMS). Polymeric materials and elastomers have found applications in a wide variety of micro-devices. This thesis investigates the AJM of such materials, addressing the major challenges that must be overcome in order for the process to gain wider acceptance in industry. The thesis first presents a novel cryogenically assisted abrasive jet micro-machining (CAJM) technique that enables the micro-machining of elastomers such as polydimethylsiloxane (PDMS) that cannot be machined at room temperature. It was found that the erosion rate during CAJM is greatly increased, and the degree of particle embedment greatly decreased, compared to room temperature experiments. A finite element (FE) analysis was used to investigate the relationships between erosion, the heat transfer of the cooling jet and the resulting target temperature during the CAJM of channels in PDMS. The analysis illustrated the asymmetric nature of the cooling with much more cooling occurring towards the trailing edge of the jet. It was found that the predicted shape of the evolving machined surface profiles was improved significantly when a FE model was used to account for thermal distortion occurring during the CAJM process. An unwanted consequence of the AJM of polymeric materials was found to be particle embedding. Criteria leading to the embedding of spherical and angular particles in such materials were identified and modelled using rigid plastic analyses. It was found that the likelihood of embedding was proportional to the static coefficient of friction between the particle and the target for angular particles, and the depth of penetration for spherical particles. Scanning electron microscopy with

  4. 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.

  5. Viscera and muscle protein synthesis in neonatal pigs is increased more by intermittent bolus than by continuous feeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuous and intermittent bolus orogastric feedings are strategies used in infants unable to tolerate normal feeds. To determine the effects of feeding modality on protein synthesis in different tissues, neonatal pigs received a balanced formula by orogastric tube as an intermittent bolus feed eve...

  6. Shark skin: a function in feeding.

    PubMed Central

    Southall, E J; Sims, D W

    2003-01-01

    Dermal denticles are unique tooth-like structures embedded in the skin of sharks and rays that protect them from predators and ectoparasites, reduce mechanical abrasion and possibly minimize swimming-induced drag. Here, we show that juvenile lesser spotted dogfish (Scyliorhinus canicula) also use this body armour to anchor food items near their tail so that bite-sized pieces can be torn away by rapid jaw and head movements. This scale-rasp behaviour is novel among fishes and suggests a new role for skin in the feeding ecology of sharks. Scale rasping may be important ecologically because it could function to increase the dietary breadth and growth potential of juveniles. PMID:12952633

  7. 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.

  8. Dental Abrasion of Incisor caused by a Babies' Dummy Clip: A Case Report.

    PubMed

    Doğramacı, Esma J; Rossi-Fedele, Giampiero

    2015-09-01

    Tooth surface loss (TSL), the non-carious loss of tooth tissue, is considered pathological if the teeth involved experience sensitivity and pain, are functionally compromised or they detract from the patient's appearance. TSL is a common clinical finding in many patient groups, although differences between the primary and permanent dentition contribute to TSL occurring at a faster rate and with worse outcomes in the primary dentition. This case report presents localized abrasion and associated apical periodontitis affecting a single primary tooth in a 2-year-old infant following the misuse of a babies' dummy clip whilst teething. Abrasion is rare in the primary dentition. CPD/CLINICAL RELEVANCE: This article highlights an unusual presentation of dental abrasion affecting the primary dentition caused by a previously unreported foreign object; abrasion in this case was a side-effect of soothing the discomfort of teething. PMID:26630866

  9. Dry Flowing Abrasive Decontamination Technique for Pipe Systems with Swirling Air Flow

    SciTech Connect

    Kameo, Yutaka; Nakashima, Mikio; Hirabayashi, Takakuni

    2003-10-15

    A dry abrasive decontamination method was developed for removing radioactive corrosion products from surfaces of coolant pipe systems in decommissioning of a nuclear power plant. Erosion behavior of inside surfaces of stainless and carbon steel pipes by a swirling air flow containing alumina or cast-iron grit abrasive was studied. Erosion depths of the test pipes were approximately proportional to an abrasive concentration in air and an exponent of flow rate of airstream. The experimental results indicated that the present method could keep satisfactory erosion ability of abrasives even for a large-size pipe. The present method was successfully applied to {sup 60}Co-contaminated specimens sampled from a pipe of the water cleanup system of the Japan Power Demonstration Reactor.

  10. Demonstration experience with an abrasive blasting technique for decontaminating concrete pads

    SciTech Connect

    Devgun, J.S. ); Land, R.R. ); Doane, R.W. )

    1990-01-01

    A demonstration was performed for decontaminating a radioactivity contaminated concrete pad with a portable abrasive blasting system. The system utilizes a rotating blast wheel that scours the concrete surface with metal abrasive. The metal abrasive, pulverized concrete dust, and contaminants rebound into a separator chamber. The reusable metal abrasive is recycled, and the pulverized media are removed to an integral dust collection system. The exhaust is HEPA filtered to minimize release of airborne contaminants. However, the technique had limited success in reducing contamination around the cracks and seams in the concrete where the higher activity levels of contamination were detected during the radiological survey before the cleanup. The technique can be successful and cost-effective in decontaminating large areas of low contamination; however, careful characterization and planning are necessary. 3 refs., 3 figs., 1 tabs.

  11. Abrasion resistance of biaxially oriented polypropylene films coated with nanocomposite hard coatings

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Zhu, Yaofeng; Fu, Yaqin

    2013-11-01

    KMnO4-treated, functionalized, biaxially oriented polypropylene (BOPP) films coated with nano-silica hybrid material were synthesized. The abrasion resistance of the films was examined using a reciprocating fabric abrasion tester. Functional groups were confirmed by Fourier-transform infrared spectroscopy. Contact angle measurements were performed on the BOPP film surface to quantify the effectiveness of the functionalization. Results indicate that the abrasion resistance and roughness of the composite film were significantly affected by the modification of the BOPP film. Water surface contact angle of the modified BOPP films decreased from 90.1° to 71.4°,when KMnO4 concentration increased from 0 M to 0.25 M. Wettability of the BOPP films clearly improved after KMnO4 treatment. Abrasion resistance of the functionalized films coated with hybrid materials improved by 27.4% compared with that of the original film.

  12. 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.

  13. Cracks in glass electrical connector headers removed by dry blasting with fine abrasive

    NASA Technical Reports Server (NTRS)

    Eckert, R. W.

    1967-01-01

    Cracking that causes pressure leakage in glass connector headers can be alleviated by manipulating the pin bridgewire connectors. This initiates the surface and meniscus cracks. Dry blasting the header surface with a fine abrasive then removes the cracks.

  14. Surface roughness and gloss of current CAD/CAM resin composites before and after toothbrush abrasion.

    PubMed

    Koizumi, Hiroyasu; Saiki, Osamu; Nogawa, Hiroshi; Hiraba, Haruto; Okazaki, Tomoyo; Matsumura, Hideo

    2015-01-01

    The purpose of this study was to evaluate the gloss and surface roughness behaviors of newly developed CAD/CAM composite blocks with different filler contents and characteristics. The gloss and surface roughness were quantified before and after a toothbrush dentifrice abrasion test; the results were compared to the gloss and surface roughness of a ceramic CAD/CAM block. Knoop hardness was determined before abrasion test. The results were analyzed by ANOVA, Tukey HSD, and Dunnett t test (p<0.05). The rank order of Knoop hardness was as follows: Vita Mark II>Vita Enamic>Gradia block>Shofu Block HC, Lava Ultimate≥Katana Avencia block≥Cerasmart. After toothbrush abrasion, a significant difference in the gloss unit was detected between the Shofu Block HC material and the ceramic block. The Ra and Rz of the Cerasmart and Shofu Block HC materials were significantly larger than those of the ceramic block after toothbrush abrasion. PMID:26632238

  15. Feeding therapy for children with food refusal.

    PubMed

    Tamura, Fumiyo; Kikutani, Takeshi; Machida, Reiko; Takahashi, Noriaki; Nishiwaki, Keiko; Yaegaki, Ken

    2011-11-01

    Disabled children suffer not only from their primary disease, but also from other complications, including food refusal. The purpose of this study was to elucidate the relationship between these conditions and food refusal in disabled children. The effectiveness of feeding therapy in treating food refusal was also examined. The study subjects were 67 disabled children (35 boys and 32 girls; mean age at initial examination: 6.5 years, SD: 6.0 years) who attended the Nippon Dental University Hospital between April 2004 and August 2008. Of them, the 13 subjects who were diagnosed as those who refused food received feeding therapy combined with desensitization therapy for hypersensitivity. Approximately 20% of the subjects showed food refusal symptoms. Primary disease, respiratory impairment and gastroesophageal reflux were not causes of food refusal in this population. There was a significant relationship between food refusal and hypersensitivity (p = 0.021). After receiving feeding therapy, six of the seven subjects with hypersensitivity but without dysphagia at initial examination recovered from food refusal. Food refusal did not significantly correlate with tube feeding. Hypersensitivity and/or tube feeding may induce food refusal. For subjects with these conditions, feeding therapy combined with desensitization therapy is effective in achieving recovery from food refusal. PMID:22774703

  16. Maternal stress in caring for children with feeding disabilities: implications for health care providers.

    PubMed

    Adams, R A; Gordon, C; Spangler, A A

    1999-08-01

    The purposes of this study were to compare the stress experienced by mothers of children with feeding disorders to the stress experienced by mothers of children with other childhood disabilities, to compare the stress experienced by mothers of children who are tube-fed with that of mothers of children with disabilities who do not require tube feeding, to ascertain the types of stressors that mothers in both groups experience, and to determine their coping resources. Subjects were mothers of children with disabilities who had recently been discharged or were receiving outpatient care from a private rehabilitation facility in a Midwestern city. The Short Form of the Questionnaire on Resources and Stress instrument and open-ended questions developed by the researchers were used. Results were analyzed using analysis of variance. Results indicate that mothers of children requiring tube feeding experienced significantly greater stress than mothers of children with disabilities who do not require tube feedings. Mothers of children requiring tube feeding also receive less support from family and friends. To assist dietitians, other health care professionals, and university instructors in developing family-centered treatment programs, we recommend including fathers, friends, or relatives in the care and feeding process; discovering ways to include the tube-fed child in family mealtime activities; increasing public awareness of tube-feeding issues; organizing support groups; and educating dietetics students about the unique stresses experienced by mothers of children who are tube-fed. PMID:10450312

  17. Plasma polymerized coating for polycarbonate - Single layer, abrasion resistant, and antireflection

    NASA Technical Reports Server (NTRS)

    Wydeven, T.

    1977-01-01

    Plasma polymerized vinyltrimethoxy silane films were deposited on transparent polycarbonate substrates. The adherent, clear films protected the substrates from abrasion and also served as antireflection coatings. Posttreatment of the vinyltrimethoxy silane films in an oxygen glow discharge further improved the abrasion resistance. ESCA (electron spectroscopy for chemical analysis) and IR transmission spectra of some films were recorded, and an elemental analysis of the films was obtained.

  18. Experimental Study on Abrasive Waterjet Polishing of Hydraulic Turbine Blades

    NASA Astrophysics Data System (ADS)

    Khakpour, H.; Birglenl, L.; Tahan, A.; Paquet, F.

    2014-03-01

    In this paper, an experimental investigation is implemented on the abrasive waterjet polishing technique to evaluate its capability in polishing of surfaces and edges of hydraulic turbine blades. For this, the properties of this method are studied and the main parameters affecting its performance are determined. Then, an experimental test-rig is designed, manufactured and tested to be used in this study. This test-rig can be used to polish linear and planar areas on the surface of the desired workpieces. Considering the number of parameters and their levels, the Taguchi method is used to design the preliminary experiments. All experiments are then implemented according to the Taguchi L18 orthogonal array. The signal-to-noise ratios obtained from the results of these experiments are used to determine the importance of the controlled polishing parameters on the final quality of the polished surface. The evaluations on these ratios reveal that the nozzle angle and the nozzle diameter have the most important impact on the results. The outcomes of these experiments can be used as a basis to design a more precise set of experiments in which the optimal values of each parameter can be estimated.

  19. Gingival abrasion and plaque removal with manual versus electric toothbrushing.

    PubMed

    Niemi, M L; Ainamo, J; Etemadzadeh, H

    1986-08-01

    A clinical trial was designed to test the relative numbers of gingival lesions caused during standardized brushing of the teeth of 22 volunteer dental nurse students with a manual soft multitufted, a manual soft V-shaped, and an electric toothbrush. First, the left or the right side of the jaws of each subject was brushed by a dental hygienist using the manual V-shaped or the electric brush, and the other side using the manual multitufted brush. At the 2nd brushing 1 week later, the same hygienist used the multitufted brush for brushing the side contralateral to the one in which it was used the 1st week and the V-shaped manual brush instead of the electric and vice versa. After each brushing, the number of new gingival lesions was recorded and the cleansing effect evaluated by assessment of the amount of remaining plaque. This examiner was unaware of the type of brush used. The V-shaped manual toothbrush was found to have caused more gingival abrasion than the electric toothbrush (P less than 0.005) and a similar difference was found between the multitufted manual and the electric toothbrush (P less than 0.05). There was no clinically significant difference between the plaque removing effects of the 3 brushes tested. PMID:3463575

  20. Biodegradation and abrasive wear of nano restorative materials.

    PubMed

    de Paula, A B; Fucio, S B P; Ambrosano, G M B; Alonso, R C B; Sardi, J C O; Puppin-Rontani, R M

    2011-01-01

    The purpose of this study was to evaluate the biomechanical degradation of two nanofilled restorative materials (a resin-modified glass ionomer, Ketac N100 and a composite, Filtek Z350), compared with conventional materials (Vitremer and TPH Spectrum). Twenty specimens obtained from each material were divided into two storage groups (n=10): relative humidity (control) and Streptococcus mutans biofilm (biodegradation). After 7 days of storage, roughness values (Ra) and micrographs by scanning electron microscopy (SEM) were obtained. In a second experimental phase, the specimens previously subjected to biodegradation were fixed to the tooth-brushing device and abraded via toothbrushes, using dentifrice slurry (mechanical degradation). Next, these specimens were washed, dried, and reassessed by roughness and SEM. The data were submitted to repeated measures three-way analysis of variance (ANOVA) and Tukey tests (p<0.05). There was statistically significant interaction among factors: material, storage (humidity/biofilm), and abrasion (before/after). After biodegradation (S mutans biofilm storage), Ketac N100 presented the highest Ra values. Concerning bio plus mechanical challenge, TPH Spectrum, Ketac N100, and Vitremer presented the undesirable roughening of their surfaces, while the nano composite Filtek Z350 exhibited the best resistance to cumulative challenges proposed. The degraded aspect after biodegradation and the exposure of fillers after mechanical degradation were visualized in micrographs. This study demonstrated that the nanotechnology incorporated in restorative materials, as in composite resin and resin-modified glass ionomer, was important for the superior resistance to biomechanical degradation. PMID:21913859

  1. 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. PMID:27160429

  2. 1999 tubing guide

    SciTech Connect

    1999-06-01

    Petroleum Engineer International`s 1999 Tubing Guide contains performance and metallurgical data, as well as connection dimensions, on tubing from several companies. Parameters listed in each section were selected with the input of buyers and manufacturers of connections and tubing. Connections listings include: nominal tube OD, weight, tensile efficiency, sealing system, standard connection OD, special clearance OD, minimum ID and make-up loss. The grades section lists the tubing OD range, yield strength, tensile strength, hardness and whether the tubing is seamless or welded. An applications index specifies the downhole environments each grade can survive.

  3. Fluoroscopically guided nose tube drainage of mediastinal abscesses in post-operative gastro-oesophageal anastomotic leakage

    PubMed Central

    Xu, Q Y; Yin, G W; Chen, S X; Jiang, F; Bai, X J; Wu, J D

    2012-01-01

    Objective 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). Methods 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. Results 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). Conclusion 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. PMID:22806622

  4. Dressing of diamond grinding wheels by abrasive water jet for freeform optical surface grinding

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Yao, Peng; Li, Chengwu; Huang, Chuanzhen; Wang, Jun; Zhu, Hongtao; Liu, Zengwen

    2014-08-01

    During the ultra-precision grinding of a large aperture mirror made of RB-SiC, the grinding wheel becomes dull rapidly, which will lead to an increase of grinding force and a decrease of grinding ratio. In this paper, diamond grinding sticks were dressed with micro SiC abrasive water jet and water jet. Through single factorial experiments, the influence of jet pressure on the dressing performance was investigated. To analyze and evaluate the effect of dressing quantitatively, the 3D roughness and the wheel topography were measured and compared with laser scanning confocal microscope before and after dressing. The experimental results show that the abrasive grains are well protruded from binder and the distribution of the abrasive grains becomes uniform after dressing by abrasive water jet when the dressing parameters are properly selected. The dressing performance of abrasive water jet is much better than water jet. For dressing ultra-fine grit size wheels, the abrasive size of the jet should be smaller than the wheel grit size to achieve a better result. The jet pressure is an obvious influence factor of the surface topography.

  5. An energetic approach to abrasive wear of a martensitic stainless steel

    SciTech Connect

    Pamuk, U.; Baydogan, M.; Niluefer, B.; Cimenoglu, H.

    2000-04-01

    Abrasive wear is the most common type of wear that causes failure of machine elements. Examinations of abraded surfaces revealed presence of embedded particles and grooves elongated along the sliding direction. This indicates that, there are two sequential stages of an abrasion process. In the first stage, asperities on the hard surface and/or hard abrasive grains penetrate into the soft material surface and then in the second stage, they grind the surface in the sliding direction. Therefore, indentation and scratching of an indenter, which can be realized by hardness and scratch tests, can simulate the damage produced on the abraded surface. On the basis of this simulation, an energetic model is proposed for abrasive wear in the present study. In this study, abrasive wear behavior of a martensitic stainless steel is examined by hardness and scratch tests. The results of tests were evaluated to estimate the work done during abrasion and to find out the dimensional wear coefficient according to the model proposed above.

  6. A correlation between abrasion resistance and other properties of some acrylic resins used in dentistry.

    PubMed

    Harrison, A; Huggett, R; Handley, R W

    1979-01-01

    This investigation studies the relationship of hardness, elastic modulus and scratch width as dependent variables to the abrasion resistance of twenty-three dental acrylic resins. The multiple correlation R, when all three variables are used as predictors, is 0.727. Because of the significant intercorrelations between the variables themselves a stepwise multiple regression analysis showed hardness as a redundant variable. Abrasive wear can be estimated from the following equation Abrasive wear = 806.1 - 0.1498 modulus + 0.681 scratch width (R = 0.725; standard deviation of estimate +/- 50.8) The deletion of scratch width does not appreciably reduce the standard deviation of the estimate: Abrasive wear = 1063.4 - 0.2055 modulus (r = 0.683; standard deviation of estimate +/- 50.3) The method of curing the specimens conformed to the respective manufacturers' instructions. Abrasion and scratch tests were performed using methods developed by the authors and previously described in the literature, whereas the hardness and elastic modulus results were devised from standard test procedures. Further research is currently in progress to improve the predictive power of abrasion resistance with additional new variables. PMID:429382

  7. Two-Phase Abrasion in Eolian Transport of Gypsum Sand, White Sands NM

    NASA Astrophysics Data System (ADS)

    Shaw, S.; Jerolmack, D. J.; Miller, K. L.

    2014-12-01

    Downstream rounding of grains is consistently observed in natural sediment transport settings. A recent theory put forth by Domokos et al. (2014) attributes particle rounding and size reduction to a geometric curvature-driven abrasion process. This process occurs in two phases, in which irregularly shaped or angular particles round to convex shapes with negligible change in axis dimension, then slowly reduce in particle diameter. Miller et al (in review) establish the existence of two-phase abrasion in the natural setting of a fluvial gravel stream. This study examines field samples from White Sands, NM to investigate the presence of two-phase abrasion in a different, non-idealized natural environment - a high-energy, eolian gypsum dunefield. Analysis of grain shapes from White Sands confirms the two-phase abrasion process, dependent upon mode of sediment transport. We find that large sand grains carried in saltation bed load transport exhibit shape change indicative of two-phase abrasion, while smaller particles carried in suspension do not. We observe rapid shape change in bed load particles approaching a convex shape, followed by slower reduction in grain axis dimensions. Confirmation of this process in a natural, non-idealized setting establishes two-phase abrasion as a general application for bed load transport.

  8. A light-scattering study of Al2O3 abrasives of various grit sizes

    NASA Astrophysics Data System (ADS)

    Heinson, Yuli W.; Chakrabarti, Amitabha; Sorensen, Christopher M.

    2016-09-01

    We report light scattering phase function measurements for irregularly shaped Al2O3 abrasive powders of various grit sizes. Q-space analysis is applied to the angular scattering to reveal a forward scattering regime, Guinier regime, power law regime with quantifiable exponents, and an enhanced backscattering regime. The exponents of the power laws for Al2O3 abrasives decrease with increasing internal coupling parameter ρ ‧ , which is in agreement with previous observations for other irregular particles. Unlike other dust particles previously studied showing single power laws under Q-space analysis, the largest three abrasives, for which ρ ‧ ≳ 100 , showed a kink in the power law, which is possibly due to the higher degree of symmetry for the abrasives than for all the particles studied previously. Direct comparison of the 1200, 1000, and 800 grit abrasive scattering to scattering by corresponding spheres shows that the scatterings approximately coincide at the spherical particle qR ≃ ρ ‧ crossover point. Furthermore, the scattering at the maximum qR = 2 kR by the irregularly shaped abrasives is close to the geometric centers of the glories of the spheres.

  9. Leucine pulses enhance skeletal muscle protein synthesis during continuous feeding in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. Continuous feedings of fortified human milk lead to nutrient losses of fat, calcium, and phosphorous

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Skeletal muscle protein synthesis in neonatal pigs is increased more by intermittent bolus than continuous feeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Feeding by orogastric tube, using either continuous or intermittent bolus delivery, is common for infants for whom normal feeding is contraindicated. To determine the impact of different feeding modalities on muscle protein anabolism, neonatal pigs (5-7 day old) received a balanced enteral formula e...

  12. Neural Tube Defects

    MedlinePlus

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the first month ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, ...

  13. Tracheostomy tube - speaking

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000465.htm Tracheostomy tube - speaking To use the sharing features on ... are even speaking devices that can help you. Tracheostomy Tubes and Speaking Air passing through vocal cords ( ...

  14. Tracheostomy tube - speaking

    MedlinePlus

    ... key part of communicating with people. Having a tracheostomy tube can change your ability to talk and ... you can learn how to speak with a tracheostomy tube. It just takes practice. There are even ...

  15. 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).

  16. 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

  17. The Mars Environmental Compatibility Assessment MECA Abrasion Tool

    NASA Astrophysics Data System (ADS)

    Kuhlman, K. R.; Anderson, M. S.; Hinde, B. D.; Hecht, M. H.; Pike, W. T.; Marshall, J.; Meloy, T. P.; Cobbly, T.

    1999-09-01

    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

  18. 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

  19. Fluvial erosion of physically modeled abrasion-dominated slot canyons

    NASA Astrophysics Data System (ADS)

    Carter, Carissa L.; Anderson, Robert S.

    2006-11-01

    Abrasion-dominated fluvial erosion generates slot canyons in massive bedrock with intricately undulating walls. Flows in slot canyons are unusual in that the walls comprise a significant portion of the wetted perimeter of the flow during geomorphically effective floods. In Wire Pass, Utah, the upper Paria River incises through massive, crossbedded Navajo Sandstone. Incision in Wire Pass and related slots occurs only during flash floods; paleoflood debris indicates that the width/depth ratios of these flows are at times as low as 1:1. Submeter resolution field mapping of a 20-m length of Wire Pass shows that the wall morphology is a complicated combination of in-phase (meander-like) and out-of-phase (pinch and swell) undulations. In order to investigate evolution of slot canyons and the influence of their wall shapes on flow dynamics, we recorded the evolution of four distinct canyon wall morphologies in a 2.4 m flume box at the St. Anthony Falls Laboratory. In a substrate consisting of ˜ 3:2 mixtures of F110 sand and Plaster of Paris, we molded canyons with in-phase and out-of-phase undulations, and wide (6.5 cm) and narrow (4 cm) straight initial wall profiles. Discharges ranged from 1.4 L/s to 2.9 L/s, and wall and bed morphology were measured at 5 h intervals at 0.5 cm resolution. Results show efficient back-eddy erosion in the undulating canyon walls and related erosional bedforms in all channels created by vortices in the flow. Maximum filaments of velocity are depressed and asymmetric, and the implied shear stress distribution varied in space and time on the channel beds. Flow width/depth ratios strongly influence the flow structure and distribution of shear stress in a slot and appear to be a factor in dictating whether a bedrock channel widens its walls or incises its bed.

  20. Hydro- abrasive jet machining modeling for computer control and optimization

    NASA Astrophysics Data System (ADS)

    Groppetti, R.; Jovane, F.

    1993-06-01

    Use of hydro-abrasive jet machining (HAJM) for machining a wide variety of materials—metals, poly-mers, ceramics, fiber-reinforced composites, metal-matrix composites, and bonded or hybridized mate-rials—primarily for two- and three-dimensional cutting and also for drilling, turning, milling, and deburring, has been reported. However, the potential of this innovative process has not been explored fully. This article discusses process control, integration, and optimization of HAJM to establish a plat-form for the implementation of real-time adaptive control constraint (ACC), adaptive control optimiza-tion (ACO), and CAD/CAM integration. It presents the approach followed and the main results obtained during the development, implementation, automation, and integration of a HAJM cell and its computer-ized controller. After a critical analysis of the process variables and models reported in the literature to identify process variables and to define a process model suitable for HAJM real-time control and optimi-zation, to correlate process variables and parameters with machining results, and to avoid expensive and time-consuming experiments for determination of the optimal machining conditions, a process predic-tion and optimization model was identified and implemented. Then, the configuration of the HAJM cell, architecture, and multiprogramming operation of the controller in terms of monitoring, control, process result prediction, and process condition optimization were analyzed. This prediction and optimization model for selection of optimal machining conditions using multi-objective programming was analyzed. Based on the definition of an economy function and a productivity function, with suitable constraints relevant to required machining quality, required kerfing depth, and available resources, the model was applied to test cases based on experimental results.

  1. Using frictional power to model LSST removal with conventional abrasives

    NASA Astrophysics Data System (ADS)

    Allen, Richard G.; Hubler, William H.

    2015-08-01

    The stressed lap on the Large Polishing Machine (LPM) at the University of Arizona Richard F. Caris Mirror Lab has recently been used to polish the M1 and M3 surfaces of the 8.4-m mirror for the Large Synoptic Survey Telescope (LSST). Loadcells in the three 4-bar links that connect this lap to the spindle of the machine allow the translational forces and torque on the lap to be measured once a second. These force readings and all other available machine parameters are recorded in history files that can be used to create a 2D removal map from one or more polishing runs. While the Preston equation has been used for many years to predict removal in a conventional polishing process, we have adopted a new equation that assumes that removal is proportional to the energy that is transferred from the lap to the substrate via friction. Specifically, the instantaneous removal rate at any point is defined to be the product of four parameters - an energy conversion factor which we call the Allen coefficient, the coefficient of friction, the lap pressure, and the speed of the lap. The Allen coefficient is the ratio of volumetric removal to frictional energy for a particular combination of pad material, abrasive, and substrate. Because our calculations take into account changes in the coefficient of friction between the lap and mirror, our 2D removal maps usually correlate well with optical data. Removal maps for future polishing strokes are created in simulations that track the position and speed of individual lap pads.

  2. Staple Line Coverage with a Polyglycolic Acid Patch and Fibrin Glue without Pleural Abrasion after Thoracoscopic Bullectomy for Primary Spontaneous Pneumothorax

    PubMed Central

    Hong, Ki Pyo; Kim, Do Kyun; Kang, Kyung Hoon

    2016-01-01

    Background This study was conducted to determine the efficacy of staple line coverage using a polyglycolic acid patch and fibrin glue without pleural abrasion to prevent recurrent postoperative pneumothorax. Methods A retrospective analysis was carried out of 116 operations performed between January 2011 and April 2013. During this period, staple lines were covered with a polyglycolic acid patch and fibrin glue in 58 cases (group A), while 58 cases underwent thoracoscopic bullectomy only (group B). Results The median follow-up period was 33 months (range, 22 to 55 months). The duration of chest tube drainage was shorter in group A (group A 2.7±1.2 day vs. group B 3.9±2.3 day, p=0.001). Prolonged postoperative air leakage occurred more frequently in group B than in group A (43% vs. 19%, p=0.005). The postoperative recurrence rate of pneumothorax was significantly lower in group A (8.6%) than in group B (24.1%) (p=0.043). The total cost of treatment during the follow-up period, including the cost for the treatment of postoperative recurrent pneumothorax, was not significantly different between the two groups (p=0.43). Conclusion Without pleural abrasion, staple line coverage with a medium-sized polyglycolic acid patch and fibrin glue after thoracoscopic bullectomy for primary spontaneous pneumothorax is a useful technique that can reduce the duration of postoperative pleural drainage and the postoperative recurrence rate of pneumothorax. PMID:27066431

  3. Successful treatment of feline pancreatitis using an endoscopically placed gastrojejunostomy tube.

    PubMed

    Jennings, M; Center, S A; Barr, S C; Brandes, D

    2001-01-01

    A cat with pancreatitis, diagnosed using abdominal ultrasonography, fine-needle aspirate cytopathology, and increased concentration of serum trypsin-like immunoreactive substance, was treated successfully using jejunal alimentation provided through a percutaneous gastrojejunostomy tube. This method of jejunal feeding is less technically difficult, less stressful for the patient, and has fewer complications than surgically placed jejunostomy tubes. Nutritional support with jejunal feeding is superior to total parenteral nutrition, as it maintains gut integrity, decreases septic complications, and may reduce exogenous insulin requirements. The methods of tube insertion and maintenance, and the physiological advantages over other feeding methods are described. PMID:11300521

  4. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into...

  5. 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.

  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. Combined effect of end-rounded versus tapered bristles and a dentifrice on plaque removal and gingival abrasion.

    PubMed

    Caporossi, Leonardo Stephan; Dutra, Danilo Antonio Milbradt; Martins, Maritieli Righi; Prochnow, Emilia Pithan; Moreira, Carlos Heitor Cunha; Kantorski, Karla Zanini

    2016-01-01

    Two previous clinical studies evaluated the effect of end-rounded versus tapered bristles of soft manual brushes on the removal of plaque and gingival abrasion. However, the combined effect of an abrasive dentifrice on these outcomes has yet to be understood. The purpose of the present study was to compare the incidence of gingival abrasion and the degree of plaque removal obtained after the use of toothbrushes with tapered or end-rounded bristles in the presence or absence of an abrasive dentifrice. The study involved a randomized, single-blind, crossover model (n = 39) with a split-mouth design. Subjects were instructed to refrain from performing oral hygiene procedures for 72 hours. Quadrants were randomized and subjects brushed with both types of toothbrushes using a dentifrice (relative dentin abrasion = ± 160). Plaque and gingival abrasion were assessed before and after brushing. After 7 days, the experiment was repeated without the dentifrice. The average reduction in plaque scores and the average increase in the number of abrasion sites were assessed by repeated-measures ANOVA and Bonferroni's post-hoc tests. End-rounded bristles removed significantly more plaque than tapered bristles, regardless of the use of a dentifrice. The dentifrice did not improve plaque removal. In the marginal area (cervical free gingiva), no difference in the incidence of gingival abrasion was detected between toothbrush types when used with a dentifrice (p ≥ 0.05). However, the dentifrice increased the incidence of abrasion (p < 0.001), irrespective of the toothbrush type tested. End-rounded bristles therefore removed plaque more effectively without causing a higher incidence of gingival abrasion when compared with tapered bristles. An abrasive dentifrice can increase the incidence of abrasion, and should be used with caution by individuals who are at risk of developing gingival recession. PMID:26981758

  8. Failure of a novel silicone–polyurethane copolymer (Optim™) to prevent implantable cardioverter-defibrillator lead insulation abrasions

    PubMed Central

    Hauser, Robert G.; Abdelhadi, Raed H.; McGriff, Deepa M.; Kallinen Retel, Linda

    2013-01-01

    Aim The purpose of this study was to determine if Optim™, a unique copolymer of silicone and polyurethane, protects Riata ST Optim and Durata implantable cardioverter-defibrillator (ICD) leads (SJM, St Jude Medical Inc., Sylmar, CA, USA) from abrasions that cause lead failure. Methods and results We searched the US Food and Drug Administration's (FDA's) Manufacturers and User Device Experience (MAUDE) database on 13 April 2012 using the simple search terms ‘Riata ST Optim™ abrasion analysis’ and ‘Durata abrasion analysis’. Lead implant time was estimated by subtracting 3 months from the reported lead age. The MAUDE search returned 15 reports for Riata ST Optim™ and 37 reports for Durata leads, which were submitted by SJM based on its analyses of returned leads for clinical events that occurred between December 2007 and January 2012. Riata ST Optim™ leads had been implanted 29.1 ± 11.7 months. Eight of 15 leads had can abrasions and three abrasions were caused by friction with another device, most likely another lead. Four of these abrasions resulted in high-voltage failures and one death. One failure was caused by an internal insulation defect. Durata leads had been implanted 22.2 ± 10.6 months. Twelve Durata leads had can abrasions, and six leads had abrasions caused by friction with another device. Of these 18 can and other device abrasions, 13 (72%) had electrical abnormalities. Low impedances identified three internal insulation abrasions. Conclusions Riata ST Optim™ and Durata ICD leads have failed due to insulation abrasions. Optim™ did not prevent these abrasions, which developed ≤4 years after implant. Studies are needed to determine the incidence of these failures and their clinical implications. PMID:22915789

  9. Corrosion guard tubing nipple

    SciTech Connect

    Guy, W.E.

    1988-09-27

    This patent describes the process of placing a string of tubing in an oil field well; a. the string of tubing when placed extending from the surface of the earth to an oil bearing formation far below the surface, b. the string made from i. a plurality of tubing sections, ii. each section having external threads on each end, and iii. cuffs with internal threads coupling the tubing sections together, c. each of the tubing sections having i. an axis, ii. a wall thickness, and iii. a corrosion resistant coating on its inside bore; wherein the improved method comprises: d. placing a section of tubing into the well with a cuff attached to the upper end at the surface of the earth, e. dropping a corrosion resistant nipple into the cuff, f. the nipple being loose in the cuff, g. attaching an additional section of tubing onto the cuff, and h. screwing the additional section tightly to the cuff.

  10. 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.

  11. Intercostal drainage tube or intracardiac drainage tube?

    PubMed Central

    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. PMID:27397467

  12. The effect of heat treatment on the gouging abrasion resistance of alloy white cast irons

    NASA Astrophysics Data System (ADS)

    Are, I. R. S.; Arnold, B. K.

    1995-02-01

    A series of heat treatments was employed to vary the microstructure of four commercially important alloy white cast irons, the wear resistance of which was then assessed by the ASTM jaw-crusher gouging abrasion test. Compared with the as-cast condition, standard austenitizing treatments produced a substantial increase in hardness, a marked decrease in the retained aus-tenite content in the matrix, and, in general, a significant improvement in gouging abrasion resistance. The gouging abrasion resistance tended to decline with increasing austenitizing tem-perature, although the changes in hardness and retained austenite content varied, depending on alloy composition. Subcritical heat treatment at 500 ° following hardening reduced the retained austenite content to values less than 10 pct, and in three of the alloys it caused a significant fall in both hardness and gouging abrasion resistance. The net result of the heat treatments was the development of optimal gouging abrasion resistance at intermediate levels of retained aus-tenite. The differing responses of the alloys to both high-temperature austenitizing treatments and to subcritical heat treatments at 500 ° were related to the effects of the differing carbon and alloying-element concentrations on changes in the M s temperature and secondary carbide precipitation.

  13. Comparative Evaluation of Gingival Depigmentation using Tetrafluoroethane Cryosurgery and Gingival Abrasion Technique: Two Years Follow Up

    PubMed Central

    Kumar, Santhosh; Bhat, G. Subraya; Bhat, K. Mahalinga

    2013-01-01

    Objective: A comparative evaluation of the gingival depigmentation by using Tetrafluoroethane cryosurgery and the gingival abrasion technique – 2 years of follow up. Material and Methods: Ten systemically healthy patients who were aged 18 to 36 years were selected for the study. Tetrafluoroethane was used for the cryosurgical depigmentation and the gingival abrasion technique used a coarse flame shaped bur. The presence or absence of pigmentation was tabulated, based on the GPI (Gingival Pigmentation Index). For the statistical analysis, Freidman’s test was used. Results: The keratinization was completed within a week after the application of the cryogen and about 10 days after the gingival abrasion technique was done. The statistical analysis which was done after 90th, 180th days and 2 years. The p-value which was obtained (p<.001) showed the superiority of cryosurgery over the gingival abrasion. During the follow up period, no side effects were seen for both the techniques and the improved aesthetics was maintained upto 2 years. Conclusion: The use of cryogen Tetrafluoroethane is easy, practical and inexpensive as compared to gingival abrasion, due to its high rate of recurrence. Hence, it is more acceptable to the patients and the operator. Further studies are needed to assess the long term effectiveness of the cryosurgical method of depigmentation. PMID:23543863

  14. A novel cleaner for colloidal silica abrasive removal in post-Cu CMP cleaning

    NASA Astrophysics Data System (ADS)

    Haiwen, Deng; Baimei, Tan; Baohong, Gao; Chenwei, Wang; Zhangbing, Gu; Yan, Zhang

    2015-10-01

    A novel cleaning solution, named FA/O alkaline cleaner, was proposed and demonstrated in the removal of colloidal silica abrasives. In order to remove both the chemical and physical absorbed colloidal silica abrasives, an FA/OII chelating agent and non-ionic surfactant were added into the cleaner. By varying the concentration of chelating agent and non-ionic surfactant, a series of experiments were performed to determine the best cleaning results. This paper discusses the mechanism of the removal of colloidal silica abrasives with a FA/O alkaline cleaner. Based on the experiment results, it is concluded that both the FA/OII chelating and non-ionic surfactant could benefit the removal of colloidal silica abrasives. When the concentration of FA/OII chelating agent and FA/O non-ionic surfactant reached the optima value, it was demonstrated that silica abrasives could be removed efficiently by this novel cleaning solution. Project supported by the Specific Project Items No. 2 in National Long-Term Technology Development Plan (No. 2009zx02308-003) and the Hebei Province Department of Education Fund (No. QN2014208).

  15. Sliding and Abrasive Wear Behavior of WC-CoCr Coatings with Different Carbide Sizes

    NASA Astrophysics Data System (ADS)

    Thakur, Lalit; Arora, Navneet

    2013-02-01

    This study examines the sliding and abrasive wear behaviors of high-velocity oxy-fuel (HVOF)-sprayed WC-CoCr coatings with different WC grain sizes. The HVOF coating deposition was assisted by in-flight particle temperature and velocity measurement system. The powder feedstocks and their corresponding coatings were characterized by means of XRD and Field Emission Scanning Electron Microscope analysis. Hardness, porosity, and indentation fracture toughness of these coatings were calculated and compared with each other. Sliding wear resistance of these coatings was calculated using pin-on-disk tribometer (ASTM G99-90). The two-body abrasion was quantified by sliding the samples over silicon carbide (SiC) abrasive paper bonded to a rotating flat disk of auto-polisher. The mechanism of materials' removal in both the sliding and abrasive wears was studied and discussed on microstructural investigations. It was observed that fine grain WC-CoCr cermet coating exhibits higher sliding and abrasive wear resistances as compared with conventional cermet coating.

  16. 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

  17. Effect of carbonitride precipitates on the abrasive wear behaviour of hardfacing alloy

    NASA Astrophysics Data System (ADS)

    Yang, Ke; Yu, Shengfu; Li, Yingbin; Li, Chenglin

    2008-06-01

    Hardfacing alloy of martensitic stainless steel expect higher abradability to be achieved through the addition of nitrogen being provided by the fine scale precipitation of complex carbonitride particles. Niobium and titanium as the most effective carbonitride alloying elements were added in the Fe-Cr13-Mn-N hardfacing alloy to get carbonitride precipitates. Carbonitride was systematically studied by optical microscopy, scanning electronic microscopy and energy spectrum analysis. Abrasive wear resistance of hardfacing alloy in as-welded and heat-treated conditions was tested by using the belt abrasion test apparatus where the samples slide against the abrasive belt. It is found that carbonitride particles in the hardfacing alloy are complex of Cr, Ti and Nb distributing on the grain boundary or matrix of the hardfacing alloy with different number and size in as-welded and heat-treated conditions. A large number of carbonitrides can be precipitated with very fine size (nanoscale) after heat treatment. As a result, the homogeneous distribution of very fine carbonitride particles can significantly improve the grain-abrasion wear-resisting property of the hardfacing alloy, and the mass loss is plastic deformation with minimum depth of grooving by abrasive particles and fine delamination.

  18. 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. PMID:17338303

  19. [Grinding of titanium. 1. Commercial and experimental wheels made of silicon carbide abrasives].

    PubMed

    Miyakawa, O; Watanabe, K; Okawa, S; Nakano, S; Shiokawa, N; Kobayashi, M; Tamura, H

    1990-01-01

    Cast titanium was ground with commercial and experimental wheels made of silicon carbide abrasives, and their grinding performance was investigated. With the vitrified wheels made of the GC abrasive, at a higher the wheel circumferential speed and heavier the grinding pressure, the cutting rate was greater, accompanied by violent wear of the wheel. Being independent of the wheel speed, the grinding ratio reached about 1 under pressure heavier than 100 gf. The MgO-MgCl2-bonded wheels of the C abrasive exhibited a similar tendency. The manner in which the wheel was moved over the work during grinding proved to be very important, compared with the Ni-Cr alloy as reported previously. Only depression of the wheel against the work resulted in chemical attrition of the abrasive and discoloration of the work surface, or grinding burn, due to oxidation of titanium. Even when the wheel was moved over the work, chip-formation process of the cutting edge was far from ideal, and the work surface was contaminated due to reaction of titanium with the abrasive. At a higher wheel circumferential speed, more chips were loaded or built-up in the wheel and strongly rubbed the work surface, resulting in violent wear of the wheel; loading and dislodging of such chips were repeated. PMID:2134811

  20. The effect of erosion and abrasion on surface properties of composite resin

    NASA Astrophysics Data System (ADS)

    Stoleriu, S.; Andrian, S.; Pancu, G.; Nica, I.; Munteanu, A.; Balan, A.; Iovan, G.

    2016-06-01

    The aim of the study was to evaluate the surface roughness of two commercial composite resins submitted to erosive attack, to abrasive wear and to association of erosive and abrasive challenge. Standardized samples of G-snial anterior (GC Company) and Essentia (GC Company) composite resins were randomly split in 6 groups. In group 1 the samples were maintained in artificial saliva until the evaluation of surface roughness. In group 2 the samples were submitted only to erosive attack, in group 3 only to abrasive challenge and in groups 4,5, and 6 the erosive attack was followed by abrasive challenge immediately (group 4), 30 minutes after the erosive attack (group 5) and one hour after the erosive attack (group 6). The specimens were evaluated using surface roughness measuring tester SJ-210 (Mitutoyo Corporation, Japan) and the mean surface roughness values (Ra, μm) of each specimen were registered. A significantly increase of both composite resins surface roughness was recorded after erosive attack and abrasive challenge. Toothbrushing 60 minutes after acidic contact determined no significant differences in surface roughness of composite resins.

  1. Pulse Tube Refrigerator

    NASA Astrophysics Data System (ADS)

    Matsubara, Yoichi

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

  2. 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.

  3. 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.

  4. Collapse of flux tubes

    NASA Astrophysics Data System (ADS)

    Wilets, L.; Puff, R. D.

    1995-01-01

    The dynamics of an idealized, infinite, MIT-type flux tube is followed in time as the interior evolves from a pure gluon field to a q¯q plasma. We work in color U(1). q¯q pair formation is evaluated according to the Schwinger mechanism using the results of Brink and Pavel. The motion of the quarks toward the tube end caps is calculated by a Boltzmann equation including collisions. The tube undergoes damped radial oscillations until the electric field settles down to zero. The electric field stabilizes the tube against pinch instabilities; when the field vanishes, the tube disintegrates into mesons. There is only one free parameter in the problem, namely the initial flux tube radius, to which the results are very sensitive. Among various quantities calculated is the mean energy of the emitted pions.

  5. Improvement in high stress abrasive wear property of steel by hardfacing

    SciTech Connect

    Kumar, S.; Mondal, D.P.; Khaira, H.K.; Jha, A.K.

    1999-12-01

    High stress abrasive wear behavior of mild steel, medium carbon steel, and hardfacing alloy has been studied to ascertain the extent of improvement in the wear properties after hardfacing of steel. High stress abrasive wear tests were carried out by sliding the specimen against the abrasive media consisting of silicon carbide particles, rigidly bonded on paper base and mounted on disk. Maximum wear was found in the case of mild steel followed by a medium carbon alloy steel and a hardfacing alloy. Different compositions of steels and constituent phases present led to different wear rates of the specimen. The extent of improvement in wear performance of steel due to hardfacing is quite appreciable (twice compared to mild steel). Microstructural examination of the wear surface has been carried out to understand the wear mechanism.

  6. Influence of material characteristics on the abrasive wear response of some hardfacing alloys

    SciTech Connect

    Jha, A.K.; Prasad, B.K.; Dasgupta, R.; Modi, O.P.

    1999-04-01

    This study examines the abrasive wear behavior of two iron-base hardfacing materials with different combinations of carbon and chromium after deposition on a steel substrate. Effects of applied load and sliding distance on the wear behavior of the specimens were studied. Operating material removal mechanisms also were analyzed through the scanning electron microscopy (SEM) examination of typical wear surfaces, subsurface regions, and debris particles. The results suggest a significant improvement in the wear resistance of the hardfaced layers over that of the substrate. Further, the specimens overlaid with the material with low carbon and high chromium contents attained better wear resistance than the one consisting of more carbon but less chromium. The former specimens also attained superior hardness. Smoother abrasion grooves on the wear surfaces and finer debris formation during the abrasion of the hardfaced samples were consistent with wear resistance superior to that of the substrate.

  7. The rock abrasion record at Gale Crater: Mars Science Laboratory results from Bradbury Landing to Rocknest

    NASA Astrophysics Data System (ADS)

    Bridges, N. T.; Calef, F. J.; Hallet, B.; Herkenhoff, K. E.; Lanza, N. L.; Le Mouélic, S.; Newman, C. E.; Blaney, D. L.; Pablo, M. A.; Kocurek, G. A.; Langevin, Y.; Lewis, K. W.; Mangold, N.; Maurice, S.; Meslin, P.-Y.; Pinet, P.; Renno, N. O.; Rice, M. S.; Richardson, M. E.; Sautter, V.; Sletten, R. S.; Wiens, R. C.; Yingst, R. A.

    2014-06-01

    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.

  8. 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. PMID:27410370

  9. 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.

  10. Non-abrasive particulate material for permeability alteration in subsurface formations

    SciTech Connect

    DePriester, C. L.

    1985-02-26

    An improved particulate material is disclosed for use in a method for altering the permeability of a gravity override or relatively high permeability path through a subsurface earth formation resulting from fluid injection into the subsurface formation. The method includes adding selectively sized, finely divided, amorphous non-abrasive particulate material to a fluid and injecting the fluid into the gravity override or relatively high permeability path to deposit the particulate material thus altering the permeability in the override, or relatively high permeability path. The particulate material may include graphite, carbon black, clay suspensions, quartz, or other minerals reduced in size range to behave as non-abrasive amorphous material which will present a non-abrasive characteristic in injection wells and if the particulate material is produced with formation fluids from the treated formation.

  11. Wear of artificial denture teeth by use of toothbrushes. Part 1: Abrasive wear of anterior teeth.

    PubMed

    Satoh, Y; Ohtani, K; Maejima, K; Morikawa, M; Matsuzu, M; Nagai, E; Toyoma, H; Ohwa, M; Ohki, K; Kaketani, M

    1990-12-01

    High-strength denture teeth (HS teeth) were developed in order to improve the hardness and wear resistance of conventional plastic denture teeth (PL teeth), while retaining their feature of easy occlusal adjustment. The objective of this study was to evaluate the abrasive wear resistance of HS teeth. We conducted wear tests and measured surface roughness using six types of anterior artificial teeth, i.e., three types of HS teeth and three types of PL teeth, the latter serving as the control. The results of the toothbrush abrasion test revealed that the HS teeth had about 5 times greater wear resistance than the PL teeth. It was also found that the type of artificial teeth and the number of abrasive wear-testing strokes had a significant (P less than 0.05) influence on the surface roughness of artificial teeth. PMID:2074493

  12. Abrasive wear: The efects of fibres size on oil palm empty fruit bunch polyester composite

    NASA Astrophysics Data System (ADS)

    Kasolang, S.; Kalam, A.; Ahmad, M. A.; Rahman, N. A.; Suhadah, W. N.

    2012-06-01

    This paper presents an experimental investigation carried out to determine the effect of palm oil empty fruit bunch (OPEFB) fibre size in dry sliding testing of polyester composite. These composite samples were produced by mixing raw OPEFB fibre with resin. The samples were prepared at different sizes of fibre (100, 125, 180 and 250μm). Abrasion Resistance Tester (TR-600) was used to carried out abrasive wear tests in dry sliding conditions. These tests were performed at room temperature for two different loads (10 and 30N) and at a constant sliding velocity of 1.4m/s. The specific wear rates of OPEFB polyester composites were obtained. The morphology of composite surface before and after tests was also examined using 3D microscope imaging. Preliminary work on thermal distribution at the abrasive wheel point was also conducted for selected samples.

  13. 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., III; 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.

  14. CFD Based Erosion Modelling of Abrasive Waterjet Nozzle using Discrete Phase Method

    NASA Astrophysics Data System (ADS)

    Hakim Kamarudin, Naqib; Prasada Rao, A. K.; Azhari, Azmir

    2016-02-01

    In Abrasive Waterjet (AWJ) machining, the nozzle is the most critical component that influences the performance, precision and economy. Exposure to a high speed jet and abrasives makes it susceptible to wear erosion which requires for frequent replacement. The present works attempts to simulate the erosion of the nozzle wall using computational fluid dynamics. The erosion rate of the nozzle was simulated under different operating conditions. The simulation was carried out in several steps which is flow modelling, particle tracking and erosion rate calculation. Discrete Phase Method (DPM) and K-ε turbulence model was used for the simulation. Result shows that different operating conditions affect the erosion rate as well as the flow interaction of water, air and abrasives. The simulation results correlates well with past work.

  15. Influence of alumina and titanium dioxide coatings on abrasive wear resistance of AISI 1045 steel

    NASA Astrophysics Data System (ADS)

    Santos, A.; Remolina, A.; Marulanda, J.

    2016-02-01

    This project aims to compare the behaviour of an AISI 1045 steel's abrasive wear resistance when is covered with aluminium oxide (Al2O3) or Titanium dioxide (TiO2), of nanometric size, using the technique of thermal hot spray, which allows to directly project the suspension particles on the used substrate. The tests are performed based on the ASTM G65-04 standard (Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Apparatus). The results show that the amount of, lost material increases linearly with the travelled distance; also determined that the thermal treatment of hardening-tempering and the alumina and titanium dioxide coatings decrease in average a 12.9, 39.6 and 29.3% respectively the volume of released material during abrasive wear test.

  16. 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.

  17. Abrasion, erosion and scuffing resistance of carbide and oxide ceramic thermal sprayed coatings for different applications

    NASA Astrophysics Data System (ADS)

    Barbezat, G.; Nicoll, A. R.; Sickinger, A.

    1993-04-01

    In the area of antiwear coatings, carbide-containing coatings and oxide ceramic coatings are applied using different thermal spray processes in the form of individual layers. In many industries these coatings have become technically significant on components where wear and friction can cause critical damage in the form of abrasion, erosion and scuffing together with corrosion. Carbide-containing and ceramic coatings have been produced with different thermal spray processes for the determination of abrasive, adhesive and erosive wear resistance. Two types of abrasion test, namely an adhesion wear test and an erosion test in water at a high velocity, were used for the characterization of wear resistance under different conditions. The coatings were also characterized with regard to microstructure, composition and fracture toughness. The influence of the thermal spraying process parameters on the microstructure is presented together with the influence of the microstructure on the behavior of the coatings under simulated service conditions.

  18. Considerations on the European Standard EN 14157 Test Methods: Abrasion Resistance of Natural Stones Used for Flooring in Buildings

    NASA Astrophysics Data System (ADS)

    Karaca, Z.; Günes Yılmaz, N.; Goktan, R. M.

    2012-01-01

    In Europe, the Wide Wheel abrasion (WWA) test and the Böhme abrasion (BA) test are among the most widely used standard test methods for determining abrasion resistance of natural stones, the former being the reference test method in EN 14157 Standard. However, it is stated in the Annex-A (Informative) of EN 14157 Standard that very limited data are available to provide correlations between these two test methods. To be able to fill this gap, in this study, 25 different natural stones belonging to sedimentary, metamorphic and igneous groups were tested for their abrasion resistance as well as physico-mechanical properties. Also, for a better interpretation of abrasion resistance characteristics of the tested stone materials, relationships between abrasion resistance and physico-mechanical properties were statistically examined. A statistically significant linear correlation ( R 2 = 0.85; P value = 0.000) was established between the WWA test and the BA test, which could be used in practice for converting the measured abrasion resistance values from one testing method to another. It was also found that the correlation between these two test methods improved significantly ( R 2 = 0.93; P value = 0.001) when relatively high-porosity stone materials (porosity ≥1%) were separately evaluated. Both methods of abrasion resistance employed in the present study showed statistically significant linear correlations with uniaxial compressive strength and Brazilian tensile strength, the former proving to be a more influencing parameter on resistance to abrasion. Also, from the point view of representing actual abrasion mechanism of stone materials in practice, the necessity of simulating multi-directional foot traffic in abrasion testing methods was discussed. In this respect, the reference test method in the EN 14157 Standard was criticized for not fully meeting this requirement. It was also pointed out that the reference method could have some drawbacks when applied to coarse

  19. Misplacements of Enteral Feeding Tubes Increase After Hospitals Switch Brands.

    PubMed

    Wallace, Susan C; Gardner, Lea Anne

    2015-08-01

    The Pennsylvania Patient Safety Reporting System is a confidential, statewide Internet reporting system to which all Pennsylvania hospitals, outpatient-surgery facilities, birthing centers, and abortion facilities must file information on incidents and serious events. Safety Monitor is a column from Pennsylvania's Patient Safety Authority, the authority that informs nurses on issues that can affect patient safety and presents strategies they can easily integrate into practice. For more information on the authority, visit www.patientsafetyauthority.org. For the original article discussed in this column or for other articles on patient safety, click on "Patient Safety Advisories" and then "Advisory Library" in the left-hand navigation menu. PMID:26222470

  20. Ruggedized electronographic tube development

    NASA Technical Reports Server (NTRS)

    Nevin, S.

    1981-01-01

    Because of their glass components and lack of far ultraviolet sensitivity, currently available Spectracons are not suited for rocket launch. Technology developed for second generation image tubes and for magnetically focused image tubes can be applied to improve the optical and mechanical properties of these magnetically focused electronographic tubes whose 40 kilovolt signal electrons exit a 4-micrometer thick mica window and penetrate a photographic recording emulsion.

  1. Tube-welder aids

    NASA Technical Reports Server (NTRS)

    Weaver, J. F.

    1980-01-01

    Simple tools assist in setting up and welding tubes. Welder aids can be easily made to fit given tube diameter. Finished set can be used repeatedly to fix electrode-to-weld gap and mark sleeve and joint positions. Tools are readily made in tube-manufacturing plants and pay for themselves in short time in reduced labor costs and quality control: Conventional measurements are too slow for mass production and are prone to errors.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Brushing abrasion of eroded dentin after application of sodium fluoride solutions.

    PubMed

    Attin, T; Zirkel, C; Hellwig, E

    1998-01-01

    The aim of the present in vitro study was to evaluate the influence of sodium fluoride solutions on brushing abrasion of eroded dentin. Dentin specimens were prepared from 60 bovine incisors. The specimens were embedded in acrylic resin, ground flat, polished and subsequently covered with tape exposing an area of 1.8 mm x 10.0 mm in the center of the exposed dentin. The samples were alternatingly stored in a demineralizing solution (5 min) and a remineralizing solution (1 min) for 5 times. The erosive soft drink Sprite light(R) served as a demineralizing solution and artificial saliva was used as a remineralizing solution. Prior to storage in artificial saliva 15 specimens were each treated for 1 min with 250 and 2,000 ppm fluoride solution, respectively. Fifteen specimens were treated with distilled water instead of the fluoride solution (= eroded controls). The remaining samples were neither eroded with the soft drink nor fluoridated (= uneroded controls). After each immersion in artificial saliva the specimens were submitted to abrasion in a toothbrushing machine. After 5 demineralization-remineralization brushing cycles the total amount of tooth wear due to erosion and subsequent abrasion was profilometrically evaluated. Statistical analysis revealed the significantly lowest wear in the uneroded controls and the highest amount of abrasion in the eroded controls. Application of the fluoride solutions increased the wear resistance of the eroded dentin specimens, showing significantly better protection by the high-concentration compared to the low-concentration solution. The susceptibility to abrasion of the eroded dentin specimens treated with the high-concentration fluoride solution did not differ significantly from the uneroded dentin samples. It is concluded that application of 2,000 ppm sodium fluoride solutions immediately before toothbrushing significantly reduces abrasion of eroded dentin in vitro. PMID:9701659

  7. Microstructural effects in abrasive wear. Quarterly progress report, June 1981-January 1982

    SciTech Connect

    Kosel, T.H.; Rao, C.M.; Fernandes, M.T.; Fiore, N.F.

    1982-02-24

    This report describes research aimed at establishing quantitative relationships between microstructure and wear resistance of highly alloyed materials, including high-Cr white irons and powder metallurgy (PM) alloys now used or potentially to be used in coal mining, handling, and gasification. The specific types of wear under study are low-stress abrasion and gouging wear encountered in mining, coal conversion, and transfer applications. Recent work has concentrated on analysis of results. The many detailed observations obtained in the work on scratch test simulations of abrasive wear mechanisms have been summarized in drafts of three papers. The first, a study of abrasive wear mechanisms using diamond and alumina scratch tests, was included as an appendix to Quarterly Report 16/17 and has been accepted for publication in the journal Wear. Revision of the other two papers is in progress. Two papers representing our analysis of results are included as appendices to this report. The first, abrasion in multiphase alloys, was presented at the NACE conference on corrosion-erosion-wear of materials at Berkeley, California in January 1982, and will be published in the proceedings. The second, on a deformation-induced phase transformation during abrasive wear of Co-base alloys, is being submitted for publication in Metallurgical Transactions. In addition, work on the gouging abrasion resistance of the previously tested high Cr-Mo white cast irons is completed. The abstract of a short paper on the results is included as an appendix. (Note: since the appendices are, or will be, available in the open literature they have been removed from the report.)

  8. Sapphire tube pressure vessel

    SciTech Connect

    Outwater, J.O.

    2000-05-23

    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.

  9. 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.

  10. Flared tube attachment fitting

    NASA Technical Reports Server (NTRS)

    Alkire, I. D.; King, J. P., Jr.

    1980-01-01

    Tubes can be flared first, then attached to valves and other flow line components, with new fitting that can be disassembled and reused. Installed fitting can be disassembled so parts can be inspected. It can be salvaged and reused without damaging flared tube; tube can be coated, tempered, or otherwise treated after it has been flared, rather than before, as was previously required. Fitting consists of threaded male portion with conical seating surface, hexagonal nut with hole larger than other diameter of flared end of tube, and split ferrule.

  11. 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.

  12. 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

  13. Feeding underground: kinematics of feeding in caecilians.

    PubMed

    Herrel, Anthony; Measey, G John

    2012-11-01

    Caecilians are limbless amphibians that have evolved distinct cranial and postcranial specializations associated with a burrowing lifestyle. Observations on feeding behavior are rare and restricted to above-ground feeding in laboratory conditions. Here we report data on feeding in tunnels using both external video and X-ray recordings of caecilians feeding on invertebrate prey. Our data show feeding kinematics similar to those previously reported, including the pronounced neck bending observed during above-ground feeding. Our data illustrate, however, that caecilians may be much faster than previously suspected, with lunge speeds of up to 7 cm sec(-1). Although gape cycles are often slow (0.67 ± 0.29 sec), rapid jaw closure is observed during prey capture, with cycle times and jaw movement velocities similar to those observed in other terrestrial tetrapods. Finally, our data suggest that gape angles may be large (64.8 ± 18°) and that gape profiles are variable, often lacking distinct slow and fast opening and closing phases. These data illustrate the importance of recording naturalistic feeding behavior and shed light on how these animals are capable of capturing and processing prey in constrained underground environments. Additional data on species with divergent cranial morphologies would be needed to better understand the co-evolution between feeding, burrowing, and cranial design in caecilians. PMID:22927194

  14. Subsurface mechanical damage during bound abrasive grinding of fused silica glass

    NASA Astrophysics Data System (ADS)

    Blaineau, P.; André, D.; Laheurte, R.; Darnis, P.; Darbois, N.; Cahuc, O.; Neauport, J.

    2015-10-01

    The subsurface damage (SSD) introduced during bound abrasive grinding of fused silica glass was measured using a wet etch technique. Various process parameters and grinding configurations were studied. The relation between the SSD depth, the process parameters and forces applied by the grinding wheel on the sample was investigated and compared to a simulation using a discrete element method to model the grinding interface. The results reveal a relation between the SSD depth and the grinding forces normalized by the abrasive concentration. Regarding the creation of the SSD, numerical simulations indicate that only a small fraction of the largest particles in the diamond wheel are responsible for the depth of the damaged layer.

  15. Abrasion Resistance of as-Cast High-Chromium Cast Iron

    NASA Astrophysics Data System (ADS)

    Pokusová, Marcela; Berta, Igor; Šooš, Ľubomír

    2014-12-01

    High chromium cast irons are widely used as abrasion resistant materials. Their properties and wear resistance depend on carbides and on the nature of the matrix supporting these carbides. The paper presents test results of irons which contain (in wt.%) 18-22 Cr and 2-5 C, and is alloyed by 1.7 Mo + 5 Ni + 2 Mn to improve the toughness. Tests showed as-cast irons with mostly austenitic matrix achieved hardness 36-53 HRC but their relative abrasion-resistance was higher than the tool steel STN 19436 heat treated on hardness 60 HRC.

  16. Comparison of the abrasive wear resistance between amalgams, hybrid composite material and different dental cements.

    PubMed

    Gil, F J; Espias, A; Sánchez, L A; Planell, J A

    1999-12-01

    This paper reports on the abrasion wear of various restorative dental materials (three amalgams and two dental cements and a hybrid composite material) commonly used in dentistry. The mechanical properties, surface roughness and the volume loss by abrasion were determined for the different materials studied. The results showed a better profile for the amalgams versus the composite materials due to the failure of the polymeric matrix of the latter materials. However, the amalgams exhibited corrosion observed by means of Scanning Electron Microscopy. PMID:10907431

  17. Bench-to-bedside review: Routine postoperative use of the nasogastric tube – utility or futility?

    PubMed Central

    Tanguy, Michèle; Seguin, Philippe; Mallédant, Yannick

    2007-01-01

    This article provides a summary of current information on rational postoperative use of the nasogastric tube, based on a review of literature related to postoperative gastrointestinal discomfort and management with the nasogastric tube. Routine gastric decompression after major surgery neither hastens the return of bowel function nor diminishes the incidence of postoperative nausea and vomiting. The multimodal postoperative rehabilitation programme is a modern and more efficient approach. Omission of nasogastric tube decompression does not increase the incidence of anastomotic leakage or wound dehiscence. Conversely, early enteral feeding is feasible and safe, favours local immunity and gut integrity, and improves nutritional status. With the objective to feeding, nasogastric tube could be used in selected patients. To conclude, use of the nasogastric tube to prevent or limit postoperative gastrointestinal discomfort must be challenged. In contrast to gastric decompression, early gastric feeding must be considered within the new concept of fast track surgery. PMID:17214909

  18. Computer Simulation of Stress-Strain State of Pipeline Section Affected by Abrasion Due to Mechanical Impurities

    NASA Astrophysics Data System (ADS)

    Burkov, P. V.; Afanas’ev, R. G.; Burkova, S. P.

    2016-04-01

    The paper presents the effect of abrasive wear of the pipeline section occurred due to mechanical impurities in the transported gas flow. The approaches to the detection of the maximum specific wear of the pipeline wall and the geometry of abrasion are the main problems of computer simulation described in this paper.

  19. Preparation of Fe-doped colloidal SiO(2) abrasives and their chemical mechanical polishing behavior on sapphire substrates.

    PubMed

    Lei, Hong; Gu, Qian; Chen, Ruling; Wang, Zhanyong

    2015-08-20

    Abrasives are one of key influencing factors on surface quality during chemical mechanical polishing (CMP). Silica sol, a widely used abrasive in CMP slurries for sapphire substrates, often causes lower material removal rate (MRRs). In the present paper, Fe-doped colloidal SiO2 composite abrasives were prepared by a seed-induced growth method in order to improve the MRR of sapphire substrates. The CMP performance of Fe-doped colloidal SiO2 abrasives on sapphire substrates was investigated using UNIPOL-1502 CMP equipment. Experimental results indicate that the Fe-doped colloidal SiO2 composite abrasives exhibit lower surface roughness and higher MRR than pure colloidal SiO2 abrasives for sapphire substrates under the same testing conditions. Furthermore, the acting mechanism of Fe-doped colloidal SiO2 composite abrasives in sapphire CMP was analyzed by x-ray photoelectron spectroscopy. Analytical results show that the Fe in the composite abrasives can react with the sapphire substrates to form aluminum ferrite (AlFeO3) during CMP, which promotes the chemical effect in CMP and leads to improvement of MRR. PMID:26368752

  20. Steam generator tube failures

    SciTech Connect

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

    1996-04-01

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

  1. Breastfeeding vs. Formula Feeding

    MedlinePlus

    ... breastfeed your baby or bottle feed using infant formula . Health experts agree that breastfeeding is the healthiest ... is hungry. You do not need to make formula before feeding, worry about clean water, or carry ...

  2. A critical review of non-carious cervical (wear) lesions and the role of abfraction, erosion, and abrasion.

    PubMed

    Bartlett, D W; Shah, P

    2006-04-01

    The terms 'abfraction' and 'abrasion' describe the cause of lesions found along the cervical margins of teeth. Erosion, abrasion, and attrition have all been associated with their formation. Early research suggested that the cause of the V-shaped lesion was excessive horizontal toothbrushing. Abfraction is another possible etiology and involves occlusal stress, producing cervical cracks that predispose the surface to erosion and abrasion. This article critically reviews the literature on abrasion, erosion, and abrasion, and abfraction. The references were obtained by a MEDLINE search in March, 2005, and from this, hand searches were undertaken. From the literature, there is little evidence, apart from laboratory studies, to indicate that abfraction exists other than as a hypothetical component of cervical wear. PMID:16567549

  3. Welding Tubes In Place

    NASA Technical Reports Server (NTRS)

    Meredith, R.

    1984-01-01

    Special welding equipment joins metal tubes that carry pressurized cyrogenic fluids. Equipment small enough to be used in confined spaces in which such tubes often mounted. Welded joints lighter in weight and more leak-proof than joints made with mechanical fittings.

  4. 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.

  5. 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.

  6. 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

  7. Limited approach to the right flank for placement of a duodenostomy tube.

    PubMed

    Novo, R E; Churchill, J; Faudskar, L; Lipowitz, A J

    2001-01-01

    A new enterostomy tube placement technique is described for provision of nutrients into the duodenum. Placement of the duodenostomy tube (d-tube) is performed through a limited right flank approach under sedation and local anesthesia. Seven client-owned animals (three dogs and four cats) requiring enteral nutritional support were selected for d-tube placement. Patients were fed via the d-tube for two to 28 days. Complications included discomfort when manipulating and exteriorizing the duodenum, discomfort with bolus feedings, local cellulitis, and tube site infection. All complications resolved without further incident. This technique should be considered in patients that are not good candidates for prolonged general anesthesia or esophageal or gastric feeding, or patients being mechanically ventilated. PMID:11300529

  8. Protein deposition in the hindquarters of neonatal pigs is enhanced by intermittent bolus compared to continuous feeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Orogastric tube feeding is indicated in neonates with impaired ability to feed, and can be administered by an intermittent bolus or continuous schedule. The aim of this study was to determine how these feeding modalities affect protein turnover. Neonatal pigs (n=6/group, 9-d-old) were overnight fast...

  9. A review on nozzle wear in abrasive water jet machining application

    NASA Astrophysics Data System (ADS)

    Syazwani, H.; Mebrahitom, G.; Azmir, A.

    2016-02-01

    This paper discusses a review on nozzle wear in abrasive water jet machining application. Wear of the nozzle becomes a major problem since it may affect the water jet machining performance. Design, materials, and life of the nozzle give significance effect to the nozzle wear. There are various parameters that may influence the wear rate of the nozzle such as nozzle length, nozzle inlet angle, nozzle diameter, orifice diameter, abrasive flow rate and water pressure. The wear rate of the nozzle can be minimized by controlling these parameters. The mechanism of wear in the nozzle is similar to other traditional machining processes which uses a cutting tool. The high pressure of the water and hard abrasive particles may erode the nozzle wall. A new nozzle using a tungsten carbide-based material has been developed to reduce the wear rate and improve the nozzle life. Apart from that, prevention of the nozzle wear has been achieved using porous lubricated nozzle. This paper presents a comprehensive review about the wear of abrasive water jet nozzle.

  10. 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.

  11. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

  12. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

  13. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

  14. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

  15. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part...

  16. Microstructural effects in abrasive wear. Quarterly progress report, January 1-June 1, 1980

    SciTech Connect

    Fiore, N.F.; Kosel, T.H.; Channagiri, M.; Desai, V.; Fulcher, J.; Shetty, H.R.

    1980-06-01

    Research aimed at establishing quantitative relationships between microstructure and wear resistance of highly alloyed materials is described including high-Cr white irons and experimental Co-base and Ni-base powder metallurgy (PM) alloys now used or potentially to be used in coal mining, handling and gasification. The specific types of wear under study are low-stress abrasion and gouging wear encountered in mining, coal conversion and transfer applications. Research has concentrated on the investigation of wear in Co-base PM alloys No. 19 and No. 6, which have been sintered to provide different carbide sizes at the same volume fraction in each respective alloy. Low-stress abrasion tests using Al/sub 2/O/sub 3/ abrasive have been completed on Alloy No. 19 and the results show a monotonic decrease in wear rate with increasing size. A series of single-point scratch test simulations of abrasive wear mechanisms has been initiated, and these tests provide valuable insights into material removal processes in the Co-base alloys.

  17. Abrasive Wear Behaviour of COPPER-SiC and COPPER-SiO2 Composites

    NASA Astrophysics Data System (ADS)

    Umale, Tejas; Singh, Amarjit; Reddy, Y.; Khatitrkar, R. K.; Sapate, S. G.

    The present paper reports abrasive wear behaviour of copper matrix composites reinforced with silicon carbide and silica particles. Copper - SiC (12%) and Copper-SiO2 (9%) composites were prepared by powder metallurgical technique. Metallography, image analysis and hardness studies were carried out on copper composites. The abrasive wear experiments were carried out using pin on disc apparatus. The effect of sliding distance and load was studied on Copper - SiC (12%) and Copper-SiO2 (9%) composites. The abrasive wear volume loss increased with sliding distance in both the composites although the magnitude of increase was different in each case. Copper - SiC (12%) composites exhibited relatively better abrasion resistance as compared to and Copper-SiO2 (9%) composites. The abraded surfaces were observed under scanning electron microscope to study the morphology of abraded surfaces and operating wear mechanism. The analysis of wear debris particles was also carried out to substantiate the findings of the investigation.

  18. 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.

  19. Parametric Study to Correlate the Applied Factors and Abrasive Wear Resistance of HVOF Coating

    NASA Astrophysics Data System (ADS)

    Sharma, Satpal

    2012-12-01

    Co-Ni-base powder was modified with the addition of CeO2 to study the effect of CeO2 addition on microstructure, hardness, and abrasive wear behavior of the unmodified (without CeO2) and modified (with CeO2) HVOF sprayed coatings. To investigate the abrasive wear behavior of coatings statistical response surface methodology (RSM) with four factors such as load, abrasive size, sliding distance, and temperature with three levels of each factor were used. Analysis of variance (ANOVA) was carried out to determine the significant factors and their interactions. Thus abrasive wear model was developed in terms of main factors and their significant interactions. The validity of the model was evaluated by conducting experiments under different wear conditions. A comparison of modeled and experimental results showed 2-8% error. The wear resistance of coatings increased with the addition of CeO2. This is due to increase in hardness with the addition of CeO2 in Co-Ni-base coatings.

  20. Sand abrasion injury and plant survival in cotton seedlings of different ages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of crops are exposed to wind-blown soil abrasion injury each year and in many instances the damage is severe enough to require replanting. Little attention has been given to plant physiological or morphological factors that may lend resistance to, or enhance recovery from, wind-...

  1. ICAM-1 mediates surface contact between neutrophils and keratocytes following corneal epithelial abrasion in the mouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. NK cells modulate the inflammatory response to corneal epithelial abrasion and thereby support wound healing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. Intraoral leukoplakia, abrasion, periodontal breakdown, and tooth loss in a snuff dipper.

    PubMed

    Christen, A G; Armstrong, W R; McDaniel, R K

    1979-04-01

    Dentists should be aware that snuff dipping or chewing is increasing in southern states and perhaps in other sections of the United States. These habits can lead to clinical leukoplakia, gingival recession, tooth abrasion, and periodontal bone destruction. The possibility also exists that a malignant transformation of leukoplakia can develop in persons who use snuff and other forms of tobacco. PMID:285136

  4. Abrasive wear behavior of heat-treated ABC-silicon carbide

    SciTech Connect

    Zhang, Xiao Feng; Lee, Gun Y.; Chen, Da; Ritchie, Robert O.; De Jonghe, Lutgard C.

    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.

  5. Air-propelled abrasive grit for postemergence in-row weed control in field corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Investigation of abrasion in Al–MgO metal matrix composites

    SciTech Connect

    Muharr em Pul; Çalin, Recep; Gül, Ferhat

    2014-12-15

    In this study, the effects of reinforcement volume fractions on abrasive wear behavior were examined in Al–MgO reinforced metal matrix composites of 5%, 10% and 15% reinforcement – volume ratios produced by melt-stirring. Abrasive wear tests were carried out by 60, 80 and 100 mesh sized Al{sub 2}O{sub 3} abrasive papers and pin-on-disc wear test apparatus under 10, 20 and 30 N loads at 0.2 m/s sliding speed. The mechanical properties such as hardness and fracture strength were determined. Subsequent to the wear tests, the microstructures of worn surfaces were examined by scanning electron microscope analyses. While increased MgO reinforcement volume fraction in the composite resulted increased hardness, fracture strength was determined to decrease. Additionally, it was found that increased MgO reinforcement volume fraction in the composite was accompanied with increased wear loss and porosity as well as reinforcement – volume ratio was identified to be significant determinants of abrasive wear behavior.

  7. PAGMan - propelled abrasive grit to manage weeds in soybean and corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New tools for controlling weeds would be useful for soybean and corn production in organic systems or in systems in which weeds developed resistance to multiple herbicides. Here we report on two developments: (i) the safety to soybean seedlings of using air-propelled abrasive grit (PAG) for managing...

  8. Characterization of abrasion-induced nanoparticle release from paints into liquids and air

    NASA Astrophysics Data System (ADS)

    Golanski, L.; Gaborieau, A.; Guiot, A.; Uzu, G.; Chatenet, J.; Tardif, F.

    2011-07-01

    Two standard methods for the characterization of the abrasion nanoparticle release into air and liquid from coatings containing nanoparticles were developed. Details of the abrasion processes and the measurement methods are shown. Paints were formulated in an industrial facility. Standard abrasion conditions in wet environments were simulated. The size distribution of the particles abraded into liquid was analyzed by a laser granulometer: submicrometric and micrometric particles were observed, but no nanometric particles. The nanoparticles released in liquid were deposited on filters for SEM (Scanning Electron Microscopy) analysis. No free or agglomerated nanoparticles were observed by SEM: nanoparticles seem to remain embedded in the paint matrix. The same coatings were abraded in the air using another standard method. The ELPI (Electrical Low Pressure Impactor) was used to determine the number size distribution of the dust generated. Abrasion is found to produce submicrometric and micrometric particles in the air but no nanoparticles. Further characterizations by SEM confirmed that no free or agglomerated nanoparticles were emitted: nanoparticles seem to remain embedded in the paint matrix.

  9. Two waves of neutrophil emigration in response to corneal epithelial abrasion: Distinct adhesion molecule requirements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PURPOSE: Corneal abrasion results in an inflammatory response characterized by leukocyte emigration into the corneal stroma. Adhesion molecules play a critical role in leukocyte emigration to wound sites, but differences are evident in different vascular beds. In this study, the contributions of two...

  10. Laser abrasion for cosmetic and medical treatment of facial actinic damage

    SciTech Connect

    David, L.M.; Lask, G.P.; Glassberg, E.; Jacoby, R.; Abergel, R.P.

    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. 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.

  11. Platelet recruitment promotes keratocyte repopulation following corneal epithelial abrasion in the mouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Platelet response to corneal abrasion is necessary for acute inflammation and efficient re-epithelialization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose: Adhesion molecules play a critical role in leukocyte emigration to wound sites, but differences are evident in different vascular beds. This study investigates the contributions of P-selectin to neutrophil emigration into the cornea following central epithelial abrasion. Methods: Re-epithel...

  13. 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.

  14. 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

  15. Forecasting of operational indicators of grinding tools with the controlled form and orientation of abrasive grains

    NASA Astrophysics Data System (ADS)

    Korotkov, V. A.; Minkin, E. M.

    2015-09-01

    The interconnection of the abrasive grain front angle parameter with the form, orientation and wear out parameters is investigated. The form of the abrasive grains was estimated by means of form coefficient which represents the relation of diameters of the spheres described around contours of grains, to diameters of the spheres entered in them. The spatial orientation angle of the abrasive grains was defined between main (i.e. the biggest) axis of the grains and the cutting plane. It is established that, depending on an orientation angle at increase in a form coefficient of the abrasive grains can be either an increase or a decrease in the values of their front angles. In most cases, with an increase in a form coefficient of the oriented grinding grains (at orientation angles Θ=10°÷125°) the growth of their front angles is fixed. At tangential orientation of grains (Θ=0°) and at the close directions of orientation (Θ=135°÷80°) the return picture is observed. Also established that the longer the abrasive grain wears along the main axis and located in the tool body, the larger is its front angle. Besides that, the front angles of the abrasive grains reach the maximum positive values at orientation angles Θ=22.5°÷45°.Dependence of tension in grains during the work with parameters of their form, orientation and depth of embedment in the bundle is investigated. It was found that for all orientation angles of grains their tension significantly increases with an increase in their form coefficient. Besides that it is confirmed that the deeper the grain is in the bundle, the lower the tension is there. Also found that tension is minimal when the grains are tangential orientated. Further on increase the option of the grains in the direction of action of the cutting force follows. Such option of orientation is the most rational both from the point of view of minimization of tension, and for ensuring rational sizes of front angles of the abrasive grains. The

  16. Robotic Tube-Gap Inspector

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L.; Gutow, David A.; Maslakowski, John E.

    1993-01-01

    Robotic vision system measures small gaps between nearly parallel tubes. Robot-held video camera examines closely spaced tubes while computer determines gaps between tubes. Video monitor simultaneously displays data on gaps.

  17. What Are Neural Tube Defects?

    MedlinePlus

    ... NICHD Research Information Clinical Trials Resources and Publications Neural Tube Defects (NTDs): Condition Information Skip sharing on ... media links Share this: Page Content What are neural tube defects? Neural (pronounced NOOR-uhl ) tube defects ...

  18. Holder for Straightening Bent Tubes

    NASA Technical Reports Server (NTRS)

    Turner, A. R.; Polzien, E. D.

    1985-01-01

    One-piece holder restrains bent metal tube against further bending during straightening operation. Holder consists of handle 16 in. (41 cm) long welded to short, strong tube that fits around tube to be straightened.

  19. 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

  20. Glacial erosion and bedrock properties in NW Scotland: Abrasion and plucking, hardness and joint spacing

    NASA Astrophysics Data System (ADS)

    Krabbendam, Maarten; Glasser, Neil F.

    2011-07-01

    Subglacial erosion beneath glaciers occurs predominantly by abrasion and plucking, producing distinct erosional forms. The controls on the relative importance of abrasion vs. plucking are poorly understood. On the one hand, glacial conditions that favour or suppress cavity formation (ice velocity, ice thickness, and water pressure) are thought to favour plucking or abrasion, respectively. Conversely, bedrock properties are also known to control landforms, but this has rarely been analysed quantitatively. In this study we compare landforms and bedrock properties of sandstone and quartzite at the bed of a palaeo-ice stream near Ullapool in NW Scotland. The boundary between the rock types is at right angles to the westward palaeo-ice flow, and palaeoglacial conditions on both rock types were similar. We report quantitative parameters for bedrock properties (Schmidt hammer hardness and joint spacing) and use morphometric parameters to analyse the landforms. Torridon sandstone is soft but thick-bedded and with a wide joint spacing. Erosional bedforms include roche moutonnées with smoothed tops and concave stoss sides, whalebacks, and elongate p-forms, indicating a high proportion of abrasion over plucking. Cambrian quartzite is hard but thin-bedded with narrow joint spacing. Erosional landforms are angular to subangular with abundant plucked lee faces, suggesting a high proportion of plucking over abrasion. Hardness and joint spacing thus exert a strong control on subglacial erosional landforms and the mechanisms that formed them. Thus glacial conditions (ice velocity, ice thickness) can only be inferred from glacial erosional landforms if the effects of bedrock properties of the substrate are considered.

  1. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Uranium feed; natural uranium feed...) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed. The term uranium feed or natural uranium feed means natural uranium in the form of UF6 suitable for...

  2. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed...) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed. The term uranium feed or natural uranium feed means natural uranium in the form of UF6 suitable for...

  3. 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; Sidhu, Paul S.

    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, with 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.

  4. 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). PMID:27468632

  5. Fluoroscopically Guided Three-Tube Insertion for the Treatment of Postoperative Gastroesophageal Anastomotic Leakage

    PubMed Central

    Yin, Guowen; Chen, Shixi; Bai, Xiangjun; Jiang, Feng; Zhang, Qin; Xu, Lin; Xu, Weidong

    2012-01-01

    Objective To retrospectively evaluate the feasibility and effectiveness of three-tube insertion for the treatment of postoperative gastroesophageal anastomotic leakage (GEAL). Materials and Methods From January 2007 to January 2011, 28 cases of postoperative GEAL after an esophagectomy with intrathoracic esophagogastric anastomotic procedures for esophageal and cardiac carcinoma were treated by the insertion of three tubes under fluoroscopic guidance. The three tubes consisted of a drainage tube through the leak, a nasogastric decompression tube, and a nasojejunum feeding tube. The study population consisted of 28 patients (18 males, 10 females) ranging in their ages from 36 to 72 years (mean: 59 years). We evaluated the feasibility of three-tube insertion to facilitate leakage site closure, and the patients' nutritional benefit by checking their serum albumin levels between pre- and post-enteral feeding via the feeding tube. Results The three tubes were successfully placed under fluoroscopic guidance in all twenty-eight patients (100%). The procedure times for the three tube insertion ranged from 30 to 70 minutes (mean time: 45 minutes). In 27 of 28 patients (96%), leakage site closure after three-tube insertion was achieved, while it was not attained in one patient who received stent implantation as a substitute. All patients showed good tolerance of the three-tube insertion in the nasal cavity. The mean time needed for leakage treatment was 21 ± 3.5 days. The serum albumin level change was significant, increasing from pre-enteral feeding (2.5 ± 0.40 g/dL) to post-enteral feeding (3.7 ± 0.51 g/dL) via the feeding tube (p < 0.001). The duration of follow-up ranged from 7 to 60 months (mean: 28 months). Conclusion Based on the results of this study, the insertion of three tubes under fluoroscopic guidance is safe, and also provides effective relief from postesophagectomy GEAL. Moreover, our findings suggest that three-tube insertion may be used as the primary

  6. WC-Co and Cr3C2-NiCr Coatings in Low- and High-Stress Abrasive Conditions

    NASA Astrophysics Data System (ADS)

    Kašparová, Michaela; Zahálka, František; Houdková, Šárka

    2011-03-01

    The article deals with the evaluation of abrasive wear resistance and adhesive strength of thermally sprayed coatings. The main attention was paid to differences between low- and high-stress abrasive conditions of the measuring. Conclusions include the evaluation of specific properties of the WC-Co and the Cr3C2-NiCr High Velocity Oxygen Fuel coatings and the evaluation of the changes in the behavior of the abrasive media. Mainly, the relationship between the low- and high-stress abrasion conditions and the wear mechanism in the tested materials was described. For the wear test, the abrasive media of Al2O3 and SiO2 sands were chosen. During wear tests, the volume loss of the tested materials and the surface roughness of the wear tracks were measured. The wear tracks on the tested materials and abrasive sands' morphologies were observed using Scanning Electron Microscopy. It was found that high-stress abrasive conditions change the coatings' behavior very significantly, particularly that of the Cr3C2-NiCr coating. Adhesive-cohesive properties of the coatings and relationships among individual structure particles were evaluated using tensile testing. It was found that the weak bond strength among the individual splats, structure particles, and phases plays a role in the poor wear resistance of the coatings.

  7. Building with Tubes.

    ERIC Educational Resources Information Center

    D'Eugenio, Terrance, Ed.

    Text and illustrations show how to assemble furniture and toys out of cardboard tubes and sheets. Basic directions are provided, and the tools and materials necessary to the assembly of specific items are described. (MLF)

  8. Magnetic flux tube tunneling

    SciTech Connect

    Dahlburg, R.B.; Antiochos, S.K.; Norton, D.

    1997-08-01

    We present numerical simulations of the collision and subsequent interaction of {ital orthogonal} magnetic flux tubes. The simulations were carried out using a parallelized spectral algorithm for compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the flux tubes can {open_quotes}tunnel{close_quotes} through each other, a behavior not previously seen in studies of either vortex tube or magnetic flux tube interactions. Two conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch {gt}1, and the Lundquist number must be somewhat large, {ge}2880. An examination of magnetic field lines suggests that tunneling is due to a double-reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections, and {open_quotes}pass{close_quotes} through each other. The implications of these results for solar and space plasmas are discussed. {copyright} {ital 1997} {ital The American Physical Society}

  9. Ear tube insertion - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100045.htm Ear tube insertion - series—Normal anatomy To use the ... 4 Overview The eardrum (tympanic membrane) separates the ear canal from the middle ear. Update Date 8/ ...

  10. 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 usually improves, but sometimes needs minimally invasive surgery. ...

  11. Eustachian Tube Dysfunction

    MedlinePlus

    ... flying (because of altitude changes). Riding in elevators, driving through mountains or diving may also make your symptoms worse. Causes & Risk Factors What causes eustachian tube dysfunction? The most common ...

  12. 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.

  13. Snorkeling and Jones tubes

    PubMed Central

    Lam, Lewis Y. W.; Weatherhead, Robert G.

    2015-01-01

    Summary We report a case of tympanic membrane rupture during snorkeling in a 17-year-old young man who had previously undergone bilateral Jones tubes placed for epiphora. To our knowledge, this phenomenon has not been previously reported.

  14. 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.

  15. Magnetic flux tube tunneling

    NASA Astrophysics Data System (ADS)

    Dahlburg, R. B.; Antiochos, S. K.; Norton, D.

    1997-08-01

    We present numerical simulations of the collision and subsequent interaction of orthogonal magnetic flux tubes. The simulations were carried out using a parallelized spectral algorithm for compressible magnetohydrodynamics. It is found that, under a wide range of conditions, the flux tubes can ``tunnel'' through each other, a behavior not previously seen in studies of either vortex tube or magnetic flux tube interactions. Two conditions must be satisfied for tunneling to occur: the magnetic field must be highly twisted with a field line pitch >>1, and the Lundquist number must be somewhat large, >=2880. An examination of magnetic field lines suggests that tunneling is due to a double-reconnection mechanism. Initially orthogonal field lines reconnect at two specific locations, exchange interacting sections, and ``pass'' through each other. The implications of these results for solar and space plasmas are discussed.

  16. Comparison between PEEK and Ti6Al4V concerning micro-scale abrasion wear on dental applications.

    PubMed

    Sampaio, M; Buciumeanu, M; Henriques, B; Silva, F S; Souza, J C M; Gomes, J R

    2016-07-01

    In the oral cavity, abrasive wear is predictable at exposed tooth or restorative surfaces, during mastication and tooth brushing. Also, wear can occur at contacting surfaces between the Ti-based prosthetic structures and implants in presence of abrasive compounds from food or toothpaste. Thus, the aim of this work was to compare the abrasive wear resistance of PEEK and Ti6Al4V on three-body abrasion related to different hydrated silica content and loads. Surfaces of Ti6Al4V or PEEK cylinders (8mm diameter and 4mm height) were wet ground on SiC papers and then polished with 1µm diamond paste. After that, surfaces were ultrasonically cleaned in propyl alcohol for 15min and then in distilled water for 10min. Micro-scale abrasion tests were performed at 60rpm and on different normal loads (0.4, 0.8 or 1.2N) after 600 ball revolutions using suspensions with different weight contents of hydrated silica. After abrasive tests, wear scars on flat samples were measured to quantify the wear volume and characterized by scanning electron microscope (SEM) to identify the dominant wear mechanisms. Results showed a higher volume loss rate on PEEK than that recorded on Ti6Al4V,, when subjected to three-body abrasion tests involving hydrated silica suspensions. An increase in volume loss was noted on both tested materials when the abrasive content or load was increased. PEEK was characterized by less wear resistance than that on Ti6Al4V after micro-scale abrasion wear in contact with hydrated silica particles, as commonly found in toothpastes. PMID:26849309

  17. Characterization of Friction Stir Welded Tubes by Means of Tube Bulge Test

    SciTech Connect

    D'Urso, G.; Longo, M.; Giardini, C.

    2011-05-04

    Mechanical properties of friction stir welded joints are generally evaluated by means of conventional tensile test. This testing method might provide insufficient information because maximum strain obtained in tensile test before necking is small; moreover, the application of tensile test is limited when the joint path is not linear or even when the welds are executed on curved surfaces. Therefore, in some cases, it would be preferable to obtain the joints properties from other testing methods. Tube bulge test can be a valid solution for testing circumferential or longitudinal welds executed on tubular workpieces. The present work investigates the mechanical properties and the formability of friction stir welded tubes by means of tube bulge tests. The experimental campaign was performed on tubular specimens having a thickness of 3 mm and an external diameter of 40 mm, obtained starting from two semi-tubes longitudinally friction stir welded. The first step, regarding the fabrication of tubes, was performed combining a conventional forming process and friction stir welding. Sheets in Al-Mg-Si-Cu alloy AA6060 T6 were adopted for this purpose. Plates having a dimension of 225x60 mm were bent (with a bending axis parallel to the main dimension) in order to obtain semi-tubes. A particular care was devoted to the fabrication of forming devices (punch and die) in order to minimize the springback effects. Semi-tubes were then friction stir welded by means of a CNC machine tool. Some preliminary tests were carried out by varying the welding parameters, namely feed rate and rotational speed. A very simple tool having flat shoulder and cylindrical pin was used. The second step of the research was based on testing the welded tubes by means of tube bulge test. A specific equipment having axial actuators with a conical shape was adopted for this study. Some analyses were carried out on the tubes bulged up to a certain pressure level. In particular, the burst pressure and the

  18. Characterization of Friction Stir Welded Tubes by Means of Tube Bulge Test

    NASA Astrophysics Data System (ADS)

    D'Urso, G.; Longo, M.; Giardini, C.

    2011-05-01

    Mechanical properties of friction stir welded joints are generally evaluated by means of conventional tensile test. This testing method might provide insufficient information because maximum strain obtained in tensile test before necking is small; moreover, the application of tensile test is limited when the joint path is not linear or even when the welds are executed on curved surfaces. Therefore, in some cases, it would be preferable to obtain the joints properties from other testing methods. Tube bulge test can be a valid solution for testing circumferential or longitudinal welds executed on tubular workpieces. The present work investigates the mechanical properties and the formability of friction stir welded tubes by means of tube bulge tests. The experimental campaign was performed on tubular specimens having a thickness of 3 mm and an external diameter of 40 mm, obtained starting from two semi-tubes longitudinally friction stir welded. The first step, regarding the fabrication of tubes, was performed combining a conventional forming process and friction stir welding. Sheets in Al-Mg-Si-Cu alloy AA6060 T6 were adopted for this purpose. Plates having a dimension of 225×60 mm were bent (with a bending axis parallel to the main dimension) in order to obtain semi-tubes. A particular care was devoted to the fabrication of forming devices (punch and die) in order to minimize the springback effects. Semi-tubes were then friction stir welded by means of a CNC machine tool. Some preliminary tests were carried out by varying the welding parameters, namely feed rate and rotational speed. A very simple tool having flat shoulder and cylindrical pin was used. The second step of the research was based on testing the welded tubes by means of tube bulge test. A specific equipment having axial actuators with a conical shape was adopted for this study. Some analyses were carried out on the tubes bulged up to a certain pressure level. In particular, the burst pressure and the

  19. 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.

  20. Feeding premature infants banked human milk homogenized by ultrasonic treatment.

    PubMed

    Rayol, M R; Martinez, F E; Jorge, S M; Gonçalves, A L; Desai, I D

    1993-12-01

    Premature neonates fed ultrasonically homogenized human milk had better weight gain and triceps skin-fold thickness than did a control group given untreated human milk (p < 0.01) and also had lower fat loss during tube feeding (p < 0.01). Ultrasonic homogenization of human milk appears to minimize loss of fat and thus allows better growth of premature infants. PMID:8229535

  1. Feed-through connector couples RF power into vacuum chamber

    NASA Technical Reports Server (NTRS)

    Grandy, G. L.

    1967-01-01

    Feed-through device connects RF power to an RF coil in a vacuum chamber. The coil and leads are water cooled and vacuum tight seals are provided at the junctions. The device incorporates silver soldered copper tubes, polytetrafluoroethylene electrical insulators, and O-ring vacuum seals.

  2. 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

  3. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section 868.5800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy...

  4. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a surgical opening of the trachea to facilitate ventilation to the lungs. The cuff may be a separate...

  5. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a surgical opening of the trachea to facilitate ventilation to the lungs. The cuff may be a separate...

  6. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a surgical opening of the trachea to facilitate ventilation to the lungs. The cuff may be a separate...

  7. Gastrostomy Tube Use after Transoral Robotic Surgery for Oropharyngeal Cancer

    PubMed Central

    Al-khudari, Samer; Bendix, Scott; Lindholm, Jamie; Simmerman, Erin; Hall, Francis; Ghanem, Tamer

    2013-01-01

    Objective. To evaluate factors that influence gastrostomy tube (g-tube) use after transoral robotic surgery (TORS) for oropharyngeal (OP) cancer. Study Design/Methods. Retrospective review of TORS patients with OP cancer. G-tube presence was recorded before and after surgery at followup. Kaplan-Meier and Cox hazards model evaluated effects of early (T1 and T2) and advanced (T3, T4) disease, adjuvant therapy, and free flap reconstruction on g-tube use. Results. Sixteen patients had tonsillar cancer and 13 tongue base cancer. Of 22 patients who underwent TORS as primary therapy, 17 had T1 T2 stage and five T3 T4 stage. Seven underwent salvage therapy (four T1 T2 and three T3 T4). Nine underwent robotic-assisted inset free flap reconstruction. Seventeen received adjuvant therapy. Four groups were compared: primary early disease (PED) T1 and T2 tumors, primary early disease with adjunctive therapy (PEDAT), primary advanced disease (PAD) T3 and T4 tumors, and salvage therapy. Within the first year of treatment, 0% PED, 44% PEDAT, 40% PAD, and 57% salvage patients required a g-tube. Fourteen patients had a temporary nasoenteric tube (48.3%) postoperatively, and 10 required a g-tube (34.5%) within the first year. Four of 22 (18.2%) with TORS as primary treatment were g-tube dependent at one year and had received adjuvant therapy. Conclusion. PED can be managed without a g-tube after TORS. Similar feeding tube rates were found for PEDAT and PAD patients. Salvage patients have a high rate of g-tube need after TORS. PMID:23936676

  8. Biocompatibility of blood tubings.

    PubMed

    Branger, B; Garreau, M; Baudin, G; Gris, J C

    1990-10-01

    We studied hemocompatibility of various blood tubings with C3a anaphylatoxin measurement and comparative electron scanning microscopy. The following tubing materials were tested: polyvinylchloride (PVC) plasticised with phthalate (PVC), pvc plasticised with phthalate coextruded with polyurethane (PIV), and two phthalate-free lines: pvc plasticised with trimellitate coextruded with polyurethane (TRI) and pvc plasticised with LT 360 (LTP). Results of C3a generation rate showed a significant activation by all blood tubings, with a reduced rate with PIV when compared to all others. Electron scanning microscopy showed marked alterations of PIV surface on tubings stored for 6 months. Protein deposits on internal surfaces after dialysis were similar whatever tubing material was tested, but adhesive cell number was greater with TRI when compared to PVC and LTP. Hemocompatibility is unchanged with phthalate-free tubings when compared to phthalate plasticised ones. In contrast with phthalate plasticised PVC there is no beneficial effect of polyurethane coextrusion with trimellitate plasticised PVC in regard to C3a generation. PMID:2254048

  9. Aeronautical tubes and pipes

    NASA Astrophysics Data System (ADS)

    Beauclair, N.

    1984-12-01

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

  10. Early abrasion of outer silicone insulation after intracardiac lead friction in a patient with cardiac device-related infective endocarditis.

    PubMed

    Ząbek, Andrej; Małecka, Barbara; Kołodzińska, Agnieszka; Maziarz, Andrej; Lelakowski, Jacek; Kutarski, Andrej

    2012-06-01

    We present a case of a 76-year-old woman on a permanent pacing device, with early abrasion of silicone endocardial lead insulations complicated by lead-dependent infective endocarditis 13 months after placement of an implantable pulse generator. The leads were removed using transvenous technique with direct traction, and with no additional tools. In the previous report, a set of additional tools was used, and therefore intraoperative endocardial lead abrasions or mechanical damage of leads could have not been excluded. The present case undoubtedly proves that the friction of leads against each other may result in abrasions of insulation of the intracardiac section of the lead. PMID:21070260

  11. An improved automatic computer aided tube detection and labeling system on chest radiographs

    NASA Astrophysics Data System (ADS)

    Ramakrishna, Bharath; Brown, Matthew; Goldin, Jonathan; Cagnon, Christopher; Enzmann, Dieter

    2012-03-01

    Tubes like Endotracheal (ET) tube used to maintain patient's airway and the Nasogastric (NG) tube used to feed the patient and drain contents of the stomach are very commonly used in Intensive Care Units (ICU). The placement of these tubes is critical for their proper functioning and improper tube placement can even be fatal. Bedside chest radiographs are considered the quickest and safest method to check the placement of these tubes. Tertiary ICU's typically generate over 250 chest radiographs per day to confirm tube placement. This paper develops a new fully automatic prototype computer-aided detection (CAD) system for tube detection on bedside chest radiographs. The core of the CAD system is the randomized algorithm which selects tubes based on their average repeatability from seed points. The CAD algorithm is designed as a 5 stage process: Preprocessing (removing borders, histogram equalization, anisotropic filtering), Anatomy Segmentation (to identify neck, esophagus, abdomen ROI's), Seed Generation, Region Growing and Tube Selection. The preliminary evaluation was carried out on 64 cases. The prototype CAD system was able to detect ET tubes with a True Positive Rate of 0.93 and False Positive Rate of 0.02/image and NG tubes with a True Positive Rate of 0.84 and False Positive Rate of 0.02/image respectively. The results from the prototype system show that it is feasible to automatically detect both tubes on chest radiographs, with the potential to significantly speed the delivery of imaging services while maintaining high accuracy.

  12. Dynamic tube/support interaction in heat exchanger tubes

    SciTech Connect

    Chen, S.S.

    1991-01-01

    The supports for heat exchanger tubes are usually plates with drilled holes; other types of supports also have been used. To facilitate manufacture and to allow for thermal expansion of the tubes, small clearances are used between tubes and tube supports. The dynamics of tube/support interaction in heat exchangers is fairly complicated. Understanding tube dynamics and its effects is important for heat exchangers. This paper summarizes the current state of the art on this subject and to identify future research needs. Specifically, the following topics are discussed: dynamics of loosely supported tubes, tube/support gap dynamics, tube response in flow, tube damage and wear, design considerations, and future research needs. 55 refs., 1 fig.

  13. 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. PMID:27450038

  14. Abrasion and erosion testing of materials used in power production from coal

    SciTech Connect

    Tylczak, Joseph H.; Adler, Thomas A.; Rawers, James C.

    2003-09-01

    The Albany Research Center (ARC) has a long history of studying abrasive wear, related to mineral testing, handling, and processing. The center has also been instrumental in the design and development of wear test procedures and equipment. Research capabilities at ARC include Pin-on-Drum, Pin-on-Disk, and Dry Sand/Rubber Wheel abrasion tests, Jaw Crusher gouging test, Ball-on-Ball Impact test, and Jet erosion tests. Abrasive and erosive wear studies have been used to develop both new alloys and improved heat treatments of commercial alloys. As part of ARC’s newest iteration on wear testing to evaluate materials for use in new and existing pulverized coal combustion and gasifier power systems, the ARC has designed and constructed a new High Temperature Hostile Atmosphere Erosion Wear Test (HAET). This new piece of test apparatus is designed for erosive particle velocities of 10-40 m/sec and temperatures from room temperature (23°C) to 800+°C, with special control over the gas atmosphere. A variable speed whirling arm design is used to vary the impact energy of the gravity fed erosive particles. The specimens are mounted at the edge of a disk and allow a full range of impingement angles to be selected. An electric furnace heats the specimens in an enclosed retort to the selected temperature. Tests include both oxidizing conditions and reducing conditions. A range of gases, including CO, CO2, CH4, H2, H2S, HCl, N2, O2, and SO2 can be mixed and delivered to the retort. During the erosion testing a stream of abrasive powder is delivered in front of the specimens. This apparatus is designed to use low abrasive fluxes, which simulate real operating conditions in commercial power plants. Currently ~270 μm SiO2 particles are being used to simulate the abrasive impurities typically found in coal. Since operators are always striving for longer lifetimes and higher operating temperatures, this apparatus can help elucidate mechanisms of wastage and identify superior

  15. Relationship between Los Angeles attrition test and Nordic abrasion test of volcanic rocks

    NASA Astrophysics Data System (ADS)

    Krutilová, Kateřina; Prikryl, Richard

    2015-04-01

    Various volcanic rocks contribute significantly to the production of crushed stone in the Czech Republic. When used for road surfacing, results of Los Angeles attrition test (LA value below 25 or 30 depending on the mode of use) together with polished stone value are required. In the recent study, we have focused on the search for possible correlation between results obtained by Los Angeles attrition test and Nordic abrasion test, a test widely employed in Scandinavia. For the experimental study, a set of volcanic rocks from 36 active quarries was used. The rocks under study represent range of volcanic rocks from ultrabasic to acid members, formed form Neoproterozoic to Tertiary. The most favourable results of Los Angeles attrition test (i.e. the lowest LA values) were obtained for basalts (range of values 9.4-19.4) and spilites (range of values 8.4-14.9) which are in fact Neoproterozoic to Late Palaeozoic basalts affected by low grade metamorphism. Nordic abrasion test exhibited much broader range of values (6.4 to 36.9) with average value at 15.2 for basalts, resulting in weak coefficient of determination (0.19). . On contrary, narrow range of values from Nordic abrasion test of spilites (7.2-15.9), very similar to the range of LA values, is reflect in higher coefficient of determination (0.56). On contrary, the least favourable properties (LA values 12.3-29.2, Nordic abrasion 16.8-43.3) have been observed for a group of basic to intermediate rocks classified in older literature as melaphyres and diabases (ranging from basalts to trachyndesites and/or trachybasalts) of Palaeozoic age. However, in this specific group of volcanic rocks, the highest coefficient of determination (0.89) between both tests has been achieved. For volcanic rocks exhibiting acid composition (rhyolites and quartz porphyry), coefficient of determination between LA values (15.1-19.3) and Nordic abrasion test (7.3-21.9) is weak (0.42). The weakest relationship between LA values (14

  16. Mixed feed evaporator

    DOEpatents

    Vakil, Himanshu B.; Kosky, Philip G.

    1982-01-01

    In the preparation of the gaseous reactant feed to undergo a chemical reaction requiring the presence of steam, the efficiency of overall power utilization is improved by premixing the gaseous reactant feed with water and then heating to evaporate the water in the presence of the gaseous reactant feed, the heating fluid utilized being at a temperature below the boiling point of water at the pressure in the volume where the evaporation occurs.

  17. Dual-Band Feed for a Microwave Reflector Antenna

    NASA Technical Reports Server (NTRS)

    Hoppe, Daniel; Reilly, Harry

    2005-01-01

    A waveguide feed has been designed to provide specified illumination patterns for a dual-reflector antenna in two wavelength bands: 8 to 9 GHz and 30 to 40 GHz. The feed (see figure) has a coaxial configuration: A wider circular tube surrounds a narrower circular tube that serves as a waveguide for the signals in the 30-to-40-GHz band. The annular space between the narrower and the wider tube serves as a coaxial waveguide for the signals in the 8-to-9-GHz band. The nominal design frequencies of the outer and inner waveguides are 8.45 and 32 GHz, respectively. Each of the two waveguides is terminated in a component that is sized and shaped to help focus the radiation in its respective frequency band into the specified illumination pattern. For the outer waveguide, the beam-shaping termination is a corrugated horn; for the inner waveguide, the beam-shaping termination is a dielectric rod insert.

  18. Infectious waste feed system

    DOEpatents

    Coulthard, E. James

    1994-01-01

    An infectious waste feed system for comminuting infectious waste and feeding the comminuted waste to a combustor automatically without the need for human intervention. The system includes a receptacle for accepting waste materials. Preferably, the receptacle includes a first and second compartment and a means for sealing the first and second compartments from the atmosphere. A shredder is disposed to comminute waste materials accepted in the receptacle to a predetermined size. A trough is disposed to receive the comminuted waste materials from the shredder. A feeding means is disposed within the trough and is movable in a first and second direction for feeding the comminuted waste materials to a combustor.

  19. VLBI2010 Feed Comparison

    NASA Technical Reports Server (NTRS)

    Petrachenko, Bill

    2013-01-01

    VLBI2010 requires a feed that simultaneously has high efficiency over the full 2.2-14 GHz frequency range. The simultaneity requirement implies that the feed must operate at high efficiency over the full frequency range without the need to adjust its focal position to account for frequency dependent phase centre variations. Two feeds meet this specification: The Eleven Feed developed at Chalmers University. (For more information, contact Miroslav Pantaleev, miroslav.pantaleev@chalmers.se. The Eleven Feed, integrated with LNA's in a cryogenic receiver, is available as a product from Omnisys Instruments, info@omnisys.se). The Quadruple Ridged Flared Horn (QRFH) developed at the California Institute of Technology. (For more information please contact Ahmed Akgiray, aakgiray@ieee.org or Sander Weinreb, sweinreb@caltech.edu) Although not VLBI2010 compliant, two triband S/X/Ka feeds are also being developed for the commissioning of VLBI2010 antennas, for S/X observations during the VLBI2010 transition period, and to support X/Ka CRF observations. The two feeds are: The Twin Telescopes Wettzell (TTW) triband feed developed by Mirad Microwave. (For more information please contact Gerhard Kronschnabl, Gerhard.Kronschnabl@bkg.bund.de) The RAEGE (Spain) triband feed developed at Yebes Observatory. (For more information please contact Jose Antonio Lopez Perez, ja.lopezperez@oan.es)

  20. Tool Extracts Smooth, Fragile Tubes

    NASA Technical Reports Server (NTRS)

    Sanders, Fred G.

    1988-01-01

    When laterally compressible tube too slippery to pull, simple tool does job. Consists of three linked sections of steel tube with sticky rubber on inside and handles on outside. Hinged sections encircle tube to be pulled. User pulls on handles to extract tube.