bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experiences in Using Ultrasonic Testing of Bearing Steel for Demanding Applications
Authors: Trojahn W , Janser K , Roesch O 
Published: August 2006

Abstract
The demands on modern machine parts, i.e., bearings, are increasing constantly. To ensure that highly clean steel is used, a number of different test methods are commonly used. In the field of test methods the ultrasonic immersion testing has reached a dominant position. This paper will give a short comparison of the ASTM E 588-03 and the SEP 1927 standards and will point out some experiences the authors have made using ultrasonic testing as a tool to increase steel cleanliness and using ultrasonic testing and blue fracture testing as complementary test methods. To be able to use ultrasonic testing as a powerful tool, a number of side aspects like the geometry of the test piece, the structure of it, or the frequency of the used ultrasonic-probe are important. This will be demonstrated by showing results from testing and incoming inspection.
An Investigation of Specimen Geometry Effects on the Fracture Behavior of a Polytetrafluoroethylene Polymer
Authors: Joyce JA , Joyce PJ 
Published: August 2006

AbstractRecent interest by the U.S. Navy in metal filled polymers for weapons applications has resulted in a desire to characterize interactions between polymer properties associated with strain rate sensitivity, pressure sensitivity, failure mechanisms, damage mechanisms, spall strength, crystalline response to shock loading, and dynamic fracture mechanics as well as the effects of loading the polymer with various metal fillers [1]. Polytetrafluoroethylene (PTFE) is an important structural polymer that in the “7C” derivative is used for gaskets, bearing pads, piston rings, and diaphragms and when 5μm aluminum spheres are added, has important ballistic properties. Prior work [2–4] evaluated the fracture toughness of PTFE and aluminum filled PTFE over a range of temperatures and loading rates using compact tension (C(T)) specimens and the normalization method [5–7] described in Annex A15 of ASTM E 1820. Moreover, prior work [3] has shown that filling the PTFE with 10 to 25 % aluminum 5μm spheres can increase stiffness and strength while the effect on toughness can be either positive or negative depending on the loading rate and test temperature. The overall effect on fracture toughness properties derived from adding the aluminum spheres to the PTFE is small and for that reason the unfilled PTFE material was used here to study the effects of geometry on fracture toughness in this material. The normalization method was initially chosen for this project because of the scarcity and cost of specimen material, especially the filled, reactive material, the many different test conditions to be investigated, and the inadequacy of alternative methods. It was quite fortunate that the normalization method was used initially to characterize this polymer since the fracture toughness resistance curves of this material often contains ductile instabilities or “pop-ins” which would not have been well characterized by multispecimen methods. The objective of this work is to compare the fracture toughness measurements obtained from C(T) and precracked Charpy (SE(B)) specimens tested under similar test conditions. A comparison is also made between J-R curves obtained using the single specimen normalization method and the “Basic” or multispecimen procedure. A limited study of the effects of side grooving on the crack extension and on the resulting J-R curves is included here.
Verification of Analytical Models in a Fracture Mechanics Based Approach to Modeling Fretting Fatigue
Authors: Prost-Domasky SA , Brooks CL , Young N 
Published: August 2006

Abstract
A fracture mechanics-based approach which uses Mode I Stress Intensity Factor (SIFs) to estimate the influence of fretting fatigue loads (which can consist of normal and shear contact loads, as well as bulk or far-field loads) has been proposed by Rooke and Jones (“Stress Intensity Factors in Fretting Fatigue,” Journal of Strain Analysis, Vol. 14, No. 1, 1979, pp. 1–6), who proposed a cracking scenario in which a single edge crack propagates to failure under the influence of the contact and bulk stress damage drivers. A major shortcoming of this approach is that the underlying analytical method and closed form integral equations assume that the single edge crack propagates into a semi-infinite domain or half-space. Significant differences in the stress states for finite width domains have been postulated by Fellows et al. (“Contact Stresses in a Moderately Then Strip (with Particular Reference to Fretting Experiments,” Wear, Vol. 185, 1995, pp. 235–238) among others. SIFs can be roughly correlated with stress; therefore variations in the stress states normally result in variations in the SIFs. Variations in the SIFs due to shear and normal contact loads, and due to finite width effects are quantitatively evaluated with the finite element method (FEM). Results with the finite element approach are compared to those using the Rooke and Jones method, as well as other results from the open literature.
Ignition of Metals at High Temperatures in Oxygen
Authors: Slockers MJ , Robles-Culbreth R 
Published: August 2006

AbstractMaterial flammability is thought to increase with increasing oxygen concentration, increasing pressure, and increasing temperature. Interest in the effects of increasing pressure and increasing sample temperature on the flammability of metals led to an industry-sponsored program for heated promoted combustion testing of metals. In this paper, the results of heated promoted combustion tests from the industry-sponsored 98-1 program are reported. Thirteen materials were tested as heated 3.2-mm (1/8-in.) diameter rods in an enriched oxygen, elevated pressure environment. Tests were performed in 100 % oxygen, and the temperature of the sample rods varied between 260 and 1093°C with test pressures ranging from 0.2 to 2.8 MPa. The test materials were 316 stainless steel, Incology® 800 HT, Hastelloy® C-276, Hastelloy C-22, Inconel® Filler Metal 601, Inconel Filler Metal 617, Haynes® 230, Haynes 214, Hastelloy X, 310 stainless steel, alonized Haynes 230, 304 stainless steel, and alonized Incoloy 800 HT.
Proactive Mitigation of PCTFE-Related Ignition Hazards in Oxygen Systems: II. Testing of Inventoried “At-Risk” PCTFE Parts and Hazard Analyses of Corresponding Ground Service Equipment at the Kennedy Space Center
Authors: Waller JM , Murray KA , Staveland AR , Faughnan PD , Tyre D , Smith SR , Gallus T , Newton BE , Hshieh FY , Beeson HD 
Published: August 2006

AbstractRevelations of excessive property variation in polychlorotrifluoroethylene (PCTFE) semifinished and finished parts led to concerns that leaks or part failure could occur in service, possibly leading to catastrophic component or system failure by flow friction and/or kindling chain mechanisms. Such concerns led to the issuances of an internal Kennedy Space Center (KSC) Problem Advisory and a Government-Industry Data Exchange Program Materials Advisory on PCTFE. The advisories led to an engineering analysis review of PCTFE-containing ground support equipment used in “at-risk” high-pressure oxygen and air systems at KSC Representative PCTFE replacement parts used in “at-risk” systems were removed from inventory and tested. Tests included determination of (1) dimensional stability by thermomechanical analysis and metrology, (2) percent crystallinity by specific gravity, and (3) the effect of annealing on engineering tolerances. While dimensional instability was determined not to be a major issue in existing inventories, establishing traceability back to the semifinished article (starting rod or sheet stock) was often not possible. Percent crystallinity varied widely depending on part origin and thickness. Annealing was found to lead occasionally to out-of-tolerance parts. The pneumatic impact ignition threshold of PCTFE in enriched air was also determined at pressures up to 41.4 MPa. Results show that ignition does not occur at ambient oxygen concentrations. Last, hazard analyses were performed on “at-risk” systems. Two problematic designs were discovered, but based on operational histories, a recommendation was made to redesign or repair and replace on a noninterference basis.
Comparing Patients Seen in Pediatric Resident Continuity Clinics and National Ambulatory Medical Care Survey Practices: A Study From the Continuity Research Network
Authors: Serwint Janet R. , Thoma Kathleen A. , Dabrow Sharon M. , Hunt Lynn E. , Barratt Michelle S. , Shope Timothy R. , Darden Paul M. ,   for the CORNET Investigators
Published: August 2006

OBJECTIVES. The goal was to compare visit data from Continuity Research Network practices with data for a nationally representative sample of pediatric visits in practice settings from the National Ambulatory Medical Care Survey.METHODS. A cross-sectional study comparing data for Continuity Research Network practice visits during a 1-week period in 2002 with data from the 2000 National Ambulatory Medical Care Survey was performed. Continuity Research Network and National Ambulatory Medical Care Survey data were derived from 30 patient visits per practice site for patients &lt;22 years of age, with the primary care providers being residents and practicing pediatricians, respectively.RESULTS. Eighteen Continuity Research Network practices reported on 540 visits, compared with 32 National Ambulatory Medical Care Survey physicians reporting on 792 visits. Continuity Research Network patients were more likely to be black non-Hispanic or Hispanic/Latino and to have public insurance. The top 5 reasons for visits were the same for Continuity Research Network and National Ambulatory Medical Care Survey visits, although the orders varied slightly. These 5 reasons accounted for 58% of Continuity Research Network visits and 49% of National Ambulatory Medical Care Survey visits. Continuity Research Network visits were more likely to result in patient instructions to return at a specific time (78% vs 52%).CONCLUSIONS. Residents in Continuity Research Network practices provide care to more underserved patients but evaluate problems that are similar to those observed in office practices; the Continuity Research Network practices thus provide important training experiences for residents who will serve both minority and nonminority children.
A Staging System for Infantile Krabbe Disease to Predict Outcome After Unrelated Umbilical Cord Blood Transplantation
Authors: Escolar Maria L. , Poe Michele D. , Martin Holly R. , Kurtzberg Joanne 
Published: August 2006

OBJECTIVE. Infantile Krabbe disease, a rare neurodegenerative disorder that leads to rapid demyelination, dysmyelination, and death in the first 2 years of life, is responsive to treatment with umbilical cord blood transplantation provided that the patient is treated in the first weeks of life. At present, family history is the only way to identify patients that are asymptomatic with most patients being diagnosed after onset of symptoms. We hypothesized that a staging system based on clinical indicators and neurophysiological and neuroimaging measures can predict posttreatment variation in patients diagnosed with infantile Krabbe disease.
METHODS. A retrospective review of pretransplant clinical indicators and neurodevelopmental, brain imaging and neurophysiological measures was performed in 42 patients being considered for treatment with umbilical cord blood transplantation. Based on these evaluations, an expert system approach was used to develop a staging system for infantile Krabbe disease. Another set of analyses in the subset of patients who were transplanted (n = 29) evaluated the association between pretransplant stage of disease and posttransplant neurodevelopmental outcomes.
RESULTS. A staging algorithm for infants with infantile Krabbe disease was developed and tested for predicting neurodevelopmental outcome after umbilical cord blood transplantation. Standard neurophysiological and neuroimaging tests were not useful in the staging algorithm. Clinical indicators were found to best classify stage of disease. Pretransplant stage was found to be predictive of neurodevelopmental outcome.
CONCLUSIONS. We conclude that the clinical staging system based solely on signs and symptoms of disease can be used to predict outcomes after umbilical cord blood transplantation. This staging system can be used prospectively to guide physicians unfamiliar with the disorder in evaluating, monitoring, and counseling families about treatment outcomes. The staging will be useful for both patients diagnosed with infantile Krabbe disease because of clinical symptoms and those identified through neonatal screening programs.
Immediately Loaded Blade Implant Retrieved From a Man After a 20-year Loading Period: A Histologic and Histomorphometric Case Report
Authors: Stefano Danilo Di , Iezzi Giovanna , Scarano Antonio , Perrotti Vittoria , Piattelli Adriano 
Published: August 2006

Abstract
Immediate loading of root-form dental implants has shown promising results and offers treatment cost and convenience advantages to patients. Although blade implants have been immediately loaded for over 2 decades, the ability of this implant design to achieve osseointegration has been debated. The aim of the present study was to histologically evaluate the peri-implant tissues of an immediately loaded blade implant retrieved for abutment fracture after a 20-year loading period. Histologic samples were prepared and examined by light microscope. Compact, cortical, mature bone with well-formed osteons was present at the interface of the implant. Bone-to-implant contact was 51% ± 6%. The histologic data showed that osseointegration was obtained in an immediately loaded blade implant inserted into the mandible, and that mineralized tissues were maintained at the interface over a long period (20 years).
Rationale for Choices of Occlusal Schemes for Complete Dentures Supported by Implants
Authors: Nikolopoulou Fotoula , Ktena-Agapitou Pagona 
Published: August 2006

AbstractThis review of occlusal considerations for implant-supported complete dentures reflects the majority opinion of authors according to clinical observations and research-documented evidence. Occlusal concepts are presented for the implant-supported complete dentures regarding analysis of loads applied to dental implants, location and number of implants, occlusal materials, and occlusal scheme.
Preservation of the Gingival Architecture With the Scalloped Implant Design: A Clinical Report
Authors: Khatami Amir H. , Al-Ajmi Mohammed , Kleinman Alejandro 
Published: August 2006

Abstract
Replacing the missing maxillary anterior teeth with dental implants and maintaining the soft tissue structure and alveolar profile is an esthetic challenge for the restorative dentist. This clinical report describes the immediate provisional placement and prosthetic rehabilitation of 2 missing maxillary central incisors with scalloped dental implants.
Histomorphometric Evaluation of Six Dental Implant Surfaces After Early Loading in Augmented Human Sinuses
Authors: Todisco Marzio , Trisi Paolo 
Published: August 2006

AbstractThis study investigated the bone-to-implant contact (BIC) and osteoconductive capacity (OC) of 6 different implant surfaces after early loading in humans. Two implants with different surfaces were placed side-by-side in the grafted (n = 5) and nongrafted (n = 1) sinuses of 3 volunteers. Single-tooth restorations were delivered 60 days later. After 6 months of full occlusal loading, implants were retrieved in block sections for histomorphometric analysis. One implant (acid etched) placed in grafted bone failed when loaded. There were no other complications. In grafted bone, the microtextured surface achieved the highest BIC value (94.08%), followed by the oxidized (77.32%), hydroxyapatite (HA) (74.51%), sandblasted and acid-etched (51.85%), and titanium plasma-sprayed (TPS) (41.48%) surfaces. In native bone, the acid-etched surface achieved a higher BIC value (69.03%) than the HA surface (59.03%). The highest OC value in grafted bone was exhibited by the microtextured surface (34.31%), followed by the HA (28.62%), sandblasted and acid-etched (25.08%), oxidized (17.55%), and TPS (−20.47%) surfaces. The HA surface exhibited a higher OC value (30.39%) in native bone compared with the acid-etched surface (24.0%). As a whole, highest BIC and OC values were exhibited by the microtextured surface, and lowest values were exhibited by the TPS surface. All other surfaces demonstrated excellent BIC (&gt;50%) but varied in OC (range = 17.55%–28.62%). These findings are tempered by the limited scope and sample size of the study and should be considered preliminary. More research is needed to determine the impact of implant surface texture on BIC and OC.
Intracranial Complications of Pediatric Frontal Rhinosinusitis
Authors: Herrmann Brian W. , Chung James C. , Eisenbeis John F. , Forsen James W. 
Published: August 2006

Background The aim of this study was to review the presentation and management of children admitted for intracranial complications arising from frontal rhinosinusitis. We performed a retrospective case series review at two academic tertiary care children's hospitals. Methods This study consisted of children <18 years old who presented with intracranial complications from frontal rhinosinusitis between January 1, 1990 and December 31, 2002. Relevant literature was reviewed with the assistance of Medline. Presentation, type of intracranial complication, radiographic evaluations, response to treatment, and prognosis were evaluated. Results Sixteen patients were identified with intracranial complications due to frontal rhinosinusitis. Patients were usually older (mean age, 14 years and 3 months), of male gender (M/F, 4.3:1.0), and African American (AA/W, 3.0:1.0). Headache, nasal congestion, and visual changes were the most common early symptoms and neurological findings indicated advanced disease. Subdural (56%), epidural (44%), and cerebral abscesses (19%) were the most common complications. Meningitis alone was identified in 13% and was associated with another intracranial complication in 6%. Multiple intracranial complications were noted in 31%. Polymicrobial cultures were obtained in 50% of patients. Although CT was excellent in identifying orbital pathology, MRI was superior for characterization of intracranial disease. Conclusion Intracranial complications of frontal rhinosinusitis are rare in children. Early symptoms often are nonspecific, with neurological findings more commonly seen in advanced disease. Adolescent African American male patients were found to be at highest risk for intracranial complications from frontal rhinosinusitis. Headache and orbital complaints associated with rhinosinusitis in older children failing to respond to initial therapy should prompt an aggressive evaluation including MRI.
Association of Nasopharyngeal and Laryngopharyngeal Reflux with Postnasal Drip Symptomatology in Patients with and without Rhinosinusitis
Authors: Wise Sarah K. , Wise Justin C. , DelGaudio John M. 
Published: August 2006

Background Patients often report postnasal drip (PND), but objective rhinosinusitis and allergy findings are frequently absent. In this study, we evaluate the association between PND and pharyngeal reflux. Methods Sixty-eight participants underwent 24-hour pH testing, including chronic rhinosinusitis (CRS) patients persistently symptomatic after endoscopic sinus surgery, CRS patients successfully treated by endoscopic sinus surgery, and volunteers without a CRS history. The pH probes contained nasopharyngeal (NP), laryngopharyngeal (LP), and distal esophageal sensors. Participants completed the Sinonasal Outcome Test-20 (SNOT-20) and Modified Reflux Symptom Index (MRSI) questionnaires. Survey items addressing PND symptomatology were compared with NP reflux (NPR) below pH 4 and pH 5 (defined as ≥1 event), and LP reflux (LPR; defined as ≥7 events or reflux area index <6.3). Results Pearson analyses revealed a positive correlation of r = 0.87 between SNOT-20 and MRSI PND items. For NPR < pH 4, no significant difference existed between participants with and without reflux on the SNOT-20 or MRSI (p < 0.05). However, for NPR < pH 5, reflux-positive participants exhibited significantly more PND symptoms on the SNOT-20 (p = 0.030) and the MRSI (p = 0.018) compared with participants without reflux. Finally, participants with LPR had significantly more PND symptomatology on the SNOT-20 (p = 0.010) versus those without LPR. A borderline significant difference existed on the MRSI PND item between participants positive and negative for LPR (p = 0.055). Conclusion Objective evidence of NPR and LPR exists in patients reporting PND. Reflux treatment may reduce PND complaints.
Characteristics of Nasal Inverted Papilloma and Its Malignant Transformation: A Study of Cell Proliferation and Programmed Cell Death
Authors: Fan Guo-Kang , Imanaka Masashi , Yang Beibei , Takenaka Hiroshi 
Published: August 2006

Background In nasal inverted papilloma (IP) and its malignant transformation process, abnormal cell growth has been regarded as an altered proliferation of the epithelial cells, while the role of programmed cell death in this process remains to be determined. Methods An apoptotic index was calculated, and the proliferation ability by using Ki67 as a marker was evaluated in the study subjects, which consisted of 15 cases of nasal chronic sinusitis, 23 cases of nasal IP, 9 cases of nasal IP with dysplasia, 8 cases of nasal IP with squamous cell carcinoma (SCC), and 21 cases of primary SCC. In addition, expressions of apoptosis-related molecules p53, Bcl-2, Bax, and Fas were investigated also. Results The result showed that the Ki67 index increased in IP and IP with dysplasia. The Ki67 value was further enhanced in SCC within IP and primary SCC. The apoptotic index was low in IP with dysplasia, IP with SCC, and primary SCC. Concerning the expression of apoptosis-related proteins, p53 protein accumulated in IP with dysplasia, IP with SCC, and primary SCC. The p53 overexpression was directly correlated with the Ki67 index in IP and primary SCC diseases. No remarkable differences were found regarding expression of Bcl-2 and Fas productions among these diseases, and Bax protein was decreased only in primary SCC. Conclusion We concluded that inhibition of apoptosis could be an early sign of IP undergoing malignant transformation. A high proliferative rate was a characteristic of IP-associated malignant diseases.
Comparison of Norepinephrine Responsiveness of Mucosal Veins in Vivo with that of Isolated Mucosal Tissue in Vitro in Guinea Pig Nasal Mucosa
Authors: Chiba Yoshihiko , Oshita Michiko , Matsuo Kensuke , Sakai Hiroyasu , Misawa Miwa 
Published: August 2006

Background The vascular responsiveness of nasal mucosa has been determined frequently by using isolated mucosal tissues although it is not clear whether the response of the whole tissue truly reflects the response of the vasculature (especially veins) in mucosa. In this study, the in vivo responsiveness of mucosal veins was compared with in vitro responsiveness of isolated mucosal tissue in guinea pig nasal septa. Methods The in vivo venous responsiveness to norepinephrine (NE) of guinea pig nasal septal mucosa was measured by changes in the diameters of mucosal veins, stereomicroscopically. The in vitro responsiveness to NE of isolated nasal septal mucosae from guinea pigs also was determined by standard organ-bath technique. Results Application of NE induced concentration-dependent contractile responses both in vivo and in vitro with the pD2 (negative logarithm for 50% effective concentration [M] of NE) values of 5.23 ± 0.29 and 5.00 ± 0.17, respectively. Conclusion The equal potencies obtained by the in vivo and in vitro experiments suggest that an increase in tension of isolated nasal mucosal tissue might be caused by the contraction of mucosal veins. Both the in vivo and the in vitro methods used in this study might be useful for determining vasoreactivity of nasal mucosa in experimental animals.