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OBJECTIVES: First, establishment and validation of a novel questionnaire documenting the burden of xerostomia and sialadenitis symptoms, including quality of life. Second, to compare two versions regarding the answering scale (proposed developed answers Q3 vs. 0-10 visual analogue scale Q10) of our newly developed questionnaire, in order to evaluate their comprehension by patients and their reproducibility in time. STUDY DESIGN: The study is a systematic review regarding the evaluation of the existing questionnaire and a cohort study regarding the validation of our new MSGS questionnaire. MATERIALS AND METHODS: A Multidisciplinary Salivary Gland Society (MSGS) questionnaire consisting of 20 questions and two scoring systems was developed to quantify symptoms of dry mouth and sialadenitis. Validation of the questionnaire was carried out on 199 patients with salivary pathologies (digestive, nasal, or age-related xerostomia, post radiation therapy, post radioiodine therapy, Sjögren's syndrome, IgG4 disease, recurrent juvenile parotitis, stones, and strictures) and a control group of 66 healthy volunteers. The coherence of the questionnaire's items, its reliability to distinguish patients from healthy volunteers, its comparison with unstimulated sialometry, and the time to fill both versions were assessed. RESULTS: The novel MSGS questionnaire showed good internal coherence of the items, indicating its pertinence: the scale reliability coefficients amounted to a Cronbach's alpha of 0.92 for Q10 and 0.90 for Q3. The time to complete Q3 and Q10 amounted, respectively, to 5.23 min (±2.3 min) and 5.65 min (±2.64 min) for patients and to 3.94 min (±3.94 min) and 3.75 min (±2.11 min) for healthy volunteers. The difference between Q3 and Q10 was not significant. CONCLUSION: We present a novel self-administered questionnaire quantifying xerostomia and non-tumoral salivary gland pathologies. We recommend the use of the Q10 version, as its scale type is well known in the literature and it translation for international use will be more accurate. Laryngoscope, 132:322-331, 2022. ispartof: LARYNGOSCOPE vol:132 issue:2 pages:322-331 ispartof: location:United States status: published

In the current investigation, an ultrasonic imaging system originally developed for visualization of microstructures in sheet metals, with capabilities of generating plane two-dimensional images at spatial resolutions between 1 and 200 μm, was used to quantitatively evaluate a Fused Filament Fabrication (FFF) processed 3D test part. For the ultrasonic system, a custom software program was written to control all components of the inspection schemes in a continuous scan mode, including the movement of three orthogonal translational stages, as well as display a live ultrasonic image during scanning and provide tools for advanced post-processing of the recorded ultrasonic signals. Prior to collecting ultrasonic data for a selected test specimen, an optical flat reference standard was used to characterize the ultrasonic probes and to quantify the system’s mechanical stability, repeatability, and accuracy when measuring the physical dimensions of features. Ultrasonic data collected at different spatial resolutions were used to characterize a part’s surface flatness, internal defects, and fusion conditions; and to measure the physical dimensions of intended features. To validate the accuracy of the ultrasonic internal characterization, one side panel of the test specimen was removed for visual confirmation, and additional ultrasonic data was collected and compared to the original data. Finally, a suggestion is made for adopting a process to qualify or certify FFF based additive manufacturing machines in the market by applying a reliable NDE validation method to a standardized part with various features of different shapes and physical dimensions.

Most structural health monitoring (SHM) systems require transducers permanently attached to or integrated with the monitored structure to form a type of smart structure. It is difficult to permanently attach traditional ultrasonic transducers for non-destructive testing of structures for health monitoring. However, inter-digital transducers (IDTs) can be considered for on-site SHM because of the small size and economic efficiency of the IDT sensor. In this paper, an alternative sensor approach is proposed using IDT rather than conventional transducers to identify the interaction of surface acoustic waves (SAWs) with a wall-thinning defect. The SAWs generated by IDT sensors are modeled using the finite element analysis method. Acoustic wave propagation behavior in plate and pipe structures was reviewed, and the effect of the curvature of curved plate was investigated. From the interaction behavior observed between SAWs and a wallthinning defect in the pipe, which was determined using numerical simulation and tests, a novel concept is proposed for characterizing wall-thinning defects in pipelines.

The ultrasonic scattering from microtexture regions within a Ti-6Al-4V titanium alloy are analyzed for mode-converted shear wave interactions. Crystallographic orientation information gathered from electron backscatter diffraction (EBSD) measurements is used to guide the analysis, where critical orientations of the microtexture crystallites were identified and analyzed with respect to misorientation states, grain feature sizes, and shear wave propagation directions. The analysis suggests that large, aligned microtexture features within the titanium alloys can efficiently scatter and reflect the ultrasonic energy in a coherent manner when feature size, grain misorientation states, and grazing-incidence conditions are met for the shear-wave inspection fields. Analysis results are provided for a representative MTR feature which had generated a strong backscatter signal response. The results are expected to be important for NDE polycrystalline material inspections and characterization in titanium material aerospace applications.

South Korea’s suicide rate among OECD countries is a very serious level, the suicide rate among the elderly has been growing constantly have two to three times more emerging as the severity of elderly suicide and social problems than other age groups. In this study, Korean welfare panel data from 2012 (7th) to 2016 (11th) were analyzed. The final analysis included 2983 cases (Urban= 2164 cases, rural = 819 cases). Data were analyzed using Stata 14.0 program. To investigate the demographic characteristics of the subjects, frequency analysis was performed. Chi-test was used to examine differences in suicide ideation. The factors that affect suicidal ideation (personal factors, family factors, and community factors) A panel logit model was performed to see the results. As a result of the chi-square test to confirm the difference of suicidal ideation, the rate of suicide thought of urban elderly people was significantly higher than that of rural elderly people. Panel logit analysis showed that age, chronic illness, depression, public pension receipt, income, family relationship satisfaction, and marital violence affect the suicidal ideation in urban elderly people. In the rural elderly, age, subjective health status, depression, and marital violence were found to affect suicidal ideation. This study is expected to clarify the relationship between urban and rural elderly suicide ideation and influential factors and to provide basic data on policies that can consider regional characteristics in the policies related to suicide of the elderly.

Vasoreactivity to hypercapnia has been used for assessing cerebrovascular tone and control altered by ischemic stroke. Despite the high prognostic potential, traits of hypercapnia-induced hemodynamic changes have not been fully characterized in relation with baseline vascular states and brain tissue damage. To monitor cerebrovascular responses, T2- and T2∗-weighted magnetic resonance imaging (MRI) images were acquired alternatively using spin- and gradient-echo echo plannar imaging (GESE EPI) sequence with 5% CO2gas inhalation in normal ( n = 5) and acute stroke rats ( n = 10). Dynamic relative changes in cerebrovascular volume (CBV), microvascular volume (MVV), and vascular size index (VSI) were assessed from regions of interest (ROIs) delineated by the percent decrease of apparent diffusion coefficient (ADC). The baseline CBV was not affected by middle cerebral artery occlusion (MCAO) whereas the baseline MVV in ischemic areas was significantly lower than that in the rest of the brain and correlated with ADC. Vasoreactivity to hypercapnic challenge was considerably attenuated in the entire ipsilesional hemisphere including normal ADC regions, in which unsolicited, spreading depression-associated increases of CBV and MVV were observed. The lesion-dependent inhomogeneity in baseline MVV indicates the effective perfusion reserve for accurately delineating the true ischemic damage while the cascade of neuronal depolarization is probably responsible for the hemispherically lateralized changes in overall neurovascular physiology.

The purpose of this study was to determine whether the presence of intratumoral fat in hepatocellular carcinoma (HCC) could serve as an imaging biomarker to predict a favorable prognosis.After a search of the radiology and pathology databases from January 2002 to December 2010, a cohort of patients with fat-containing HCC imaged by chemical-shift MRI techniques was matched with a cohort of patients with nonfat-containing HCC for TNM stage and type of subsequent treatment. The number and type of tumor progression, time to tumor progression (TTP), and overall survival (OS) were determined for each cohort.There were 46 patients included in each cohort. Tumor progression was more prevalent in the non-fat-containing HCC cohort (30 patients, 65.2%) compared with the fat-containing HCC cohort (16 patients, 34.7%; p = 0.001). Distant metastasis occurred more commonly in the non-fat-containing HCC cohort (10 patient, 21.7%) compared with the fat-containing HCC cohort (two patients, 4.3%; p = 0.039). The median TTP was significantly longer in the fat-containing HCC group (52 months) compared with the non-fat-containing HCC group (27 months; p = 0.037). The significantly longer TTP was primarily observed in the locoregional treatment subgroup (p = 0.028). No statistical significance in OS and subanalysis by treatment was observed (p = 0.63-0.81).Fat-containing HCC, imaged on an MRI unit, may predict a more favorable prognosis compared with nonfat-containing HCC.

The current industry code and standard fitness-for-service assessment (ICS FFSA) procedures ignore the release of the welding residual stress (WRS) in defect assessment of a crack growing in a WRS field. Doing so can result in overly restrictive results in the ICS FFSA of an engineering component. The current ICS FFSA procedures have produced compendiums of WRS distributions and stress intensity factor (SIF) solutions that are characterized by the joint geometry and welding parameters. It is also known that these distributions are based on extensive numerical analyses and provide upper bound estimates; therefore, these types of solutions do not necessarily satisfy the self-equilibrating state. In this investigation, through-wall WRS distributions from the literature data, including measurements and finite element analysis (FEA) results for girth welded pipes, are compared to the representative ICS FFSA WRS procedures. Also, the WRS and SIF solutions using the proposed procedure are compared to those using the ICS FFSA procedures employing 2D and 3D models. From the investigation, it is observed that the ICS FFSA procedures show discrepancies for certain conditions and the levels of conservatism are dependent on the model geometry, boundary constraint condition, crack size, and crack shape. For some cases, the estimations provided from the ICS FFSA procedures are not conservative compared to the reference solutions from literatures and FEA simulations. As a continuous study of the previous investigation [OMAE 2015-41319], the objective of the present paper is to motivate the industry to improve ICS FFSA procedures by clarifying the ambiguous technical issues of crack-like defect assessment in weld regions.

For fatigue assessment of a welded structure, an important characteristic is the failure location. The fatigue crack begins from the pre-existing crack-like flaw which is an inherent feature of a weld toe or root. Residual stress in the welded joints is another important characteristic. It is also well known that tensile residual stress in welded structures can be as high as the material yield strength level and so the fatigue strength of the welded joint is governed by the applied stress range regardless of the applied load ratio. However, when the presumed conditions with high tensile residual stress in the weld regime are not satisfied, the fatigue behavior in welded structure deviates from the general weld fatigue behavior. In this paper, firstly the applied load ratio effect on fatigue behavior is investigated for two different residual stress levels of welds, i.e., as-welded and stress relieved. It has been observed that stress-relieving effect of welds is apparent when the applied loading introduces stress fluctuations in compressive loading. When the load ratio effect is considered in Battelle structural stress based fatigue parameter, the stress relieved weld fatigue data was consolidated within the master S-N curve. Based on this investigation, the Battelle structural stress based effective load ratio considering both applied loading and detailed residual stress is introduced for the weld fatigue behavior. The two-stage crack growth model is reformulated with the structural stress based effective load ratio, which is a function of crack length. Lastly, a fatigue life prediction procedure incorporating residual stress effect is proposed and validated using the existing fatigue test results. The proposed procedure clearly shows that the compressive residual stress distributions at the weld prone to crack provide great benefits for fatigue life improvement.

To evaluate the usefulness of low-dose CT (LDCT) for the diagnosis of acute lower respiratory infection (ALRI) in elderly patients in the emergency room (ER).A total of 160 consecutive patients (mean age: 75.9 ± 9.2 years; range: 60-97 years), who were diagnosed to have ALRI by LDCT in the ER, were enrolled in this study. Initial chest radiograph (CR) and CT patterns of ALRI were analysed, and clinical courses of patients were assessed.49 patients showed negative CR, in whom the main CT patterns were diffuse bronchial wall thickening (n = 23), ground-glass opacity (n = 6), mixed centrilobular nodules and ground-glass opacity (n = 3), small consolidation (n = 8) or consolidation in the dependent lung (n = 9), while the other 111 patients with the main CT pattern of consolidation demonstrated pulmonary abnormality on CR. Pulmonary oedema (12.5%) and pleural effusion (23.1%) were associated. The rate of hospitalization, care in the intensive care unit, mortality and comorbidity were significantly higher in the CR(+)LDCT(+) group (88.3%, 36.1%, 18.2% and 59.5%) than in the CR(-)LDCT(+) group (55.1%, 8.2%, 2.0% and 38.8%; p ≤ 0.05).LDCT was useful for the early diagnosis of ALRI in elderly patients who showed negative initial CR. The patients with negative initial CR had main CT patterns of diffuse bronchial wall thickening, ground-glass opacity, centrilobular nodules, small consolidation or consolidation in the dependent lung on LDCT.The use of LDCT may be considered for the early diagnosis of ALRI in elderly patients who have high comorbidity.

Peak amplitudes of mode converted shear wave signals back scattered from macro-texture regions (MTRs) in an aerospace grade titanium alloy material are measured to be about the same level as corner trapped shear wave signals. In addition to the abnormally high shear wave responses, the time of flight data indicates that the MTR signals are back scattered from a location deep in the sample so that the round trip travel time is close to that of corner trapped signals. In this work, these two ultrasonic properties of an MTR in a test specimen cut from a titanium jet engine disk are closely studied to understand the root cause of abnormally high shear wave responses. Based on the amplitude and time of flight data collected in a laboratory condition, a decision has been made to investigate further experimentally and computationally how surface irregularity of an acoustically reflective surface affects incoming shear waves upon reflection. Attempts are made to correlate the localized back scattered signal response of the MTR in the test specimen to the beam focusing effect of a non-planar surface of an acoustically impedance mismatched boundary layer such as a fatigue crack face. From the current experimental and computational results on the reflection of corner trapped shear waves from a concave shaped section of a non-planar crack face and the time of flight data, it is speculated that the root cause of the abnormally high peak amplitude MTR signal is possibly due to the beam focusing effect caused by the shape of the MTR.

Analytical wave models are inadequate to describe complex metallic microstructure interactions especially for near field anisotropic property effects and through geometric features smaller than the wavelength. In contrast, finite element ultrasound simulations inherently capture microstructure influences due to their reliance on material definitions rather than wave descriptions. To better understand and quantify heterogeneous crystal orientation effects to ultrasonic wave propagation, a finite element modeling case study has been performed with anisotropic titanium grain structures. A parameterized model has been developed utilizing anisotropic spheres within a bulk material. The resulting wave parameters are analyzed as functions of both wavelength and sphere to bulk crystal mismatch angle.

The nondestructive evaluation of polycrystalline materials has been an active area of research for many decades, and continues to be an area of growth in recent years. Titanium alloys in particular have become a critical material system used in modern turbine engine applications, where an evaluation of the local microstructure properties of engine disk/blade components is desired for performance and remaining life assessments. Current NDE methods are often limited to estimating ensemble material properties or detecting localized voids, inclusions, or damage features within a material. Recent advances in computational NDE and material science characterization methods are providing new and unprecedented access to heterogeneous material properties, which permits microstructure-sensing interactions to be studied in detail. In the present research, Integrated Computational Materials Engineering (ICME) methods and tools are being leveraged to gain a comprehensive understanding of root-cause ultrasonic scatterin...

구조물의 대형화와 복잡화로 인한 구조물의 안정성 평가는 재해방지뿐 아니라 경제적 고려가 필수적이다. 특히 용접구조물은 용접부의 기하학적인 불연속으로 인한 응력집중이 피로 수명에 미치는 영향이 크기 때문에 세심한 피로 설계의 고려가 요구된다. 지금까지 주로 사용된 공칭응력이나 hot spot 응력은 각 부재의 용접접합부 형상과 이에 따른 피로시험을 수행하여 피로 수명곡선을 구하여야 하는 번거로움과 유한요소 해석시 요소의 종류, 크기, 형상, 타입 이나 분포에 민감한 결과를 초래하여 실구조물의 피로평가에 어려움이 있어왔다. 이러한 단점을 보완한, 요소에 민감하지 않은 피로 평가 방법을 미국 Battelle 연구소에서 개발하였고, 이 방법을 기존의 방법과 구별하여 Battelle 구조응력법 (Structural stress method, 이하 구조응력법이라 칭함) 이라 부르게 되었다. 이 구조응력은 용접부 토우 근처의 절점에서 계산된 등가 절점력(nodal force)을 바탕으로 역학적 평형조건을 이용하여 구하며, 용접부 토우에서의 균열 진전율 등 일련의 파괴역학적 과정을 적용해 하중 모드, 두께 및 접합부 형상을 고려한 등가구조응력 (equivalent structural stress)이라는 피로 매개변수를 정의하였고, 이를 신뢰할 만한 많은 피로 데이타에 적용시켜 하나의 S-N 선도로 통합하여 용접부 피로 설계 및 평가에 효과적으로 사용할 수 있는 마스터 S-N 피로선도(master S-N curve) 를 개발하게 되었다. 따라서, 구조응력법을 적용하게 되면 CAE, FE 모델링 시간을 줄이고, 피로시험을 최소화 함으로 개발 비용과 시간을 줄일 수 있게 되며, 메쉬 둔감성의 특징을 사용함으로 기존의 피로 평가법의 불확실성과 이로 인한 과도한 보수 설계를 피할 있게 되어 구조물의 경량화 및 품질관리를 가능케 할 수 있는 장점이 있다. 이러한 개발, 적용의 타당성을 인정받음으로, Battelle 구조응력법과 이를 적용한 마스터 S-N 피로선도법이 2007년 ASME B&PV Section VIII Div 2 의 용접부 피로 설계 Codes

A miniature interdigital transducer (IDT) tuned to resonate at 3.1 MHz of frequency is designed, fabricated, and used to generate narrow band Rayleigh waves on aircraft grade metallic alloys. Electrodes of the IDT are precisely machined by a laser machining technique and its acoustical wave properties are characterized by using a scanning laser interferometry system with a spatial resolution of less than 10 microns. Unlike the conventional contact surface wave generation methods using wedges or combs, the biggest advantage of an IDT are its miniature physical size and its high efficiency in converting electrical signals to mechanical vibrations. Narrow band surface waves with finite amplitudes generated by an IDT are used to investigate the wave interaction with a tightly closed fatigue crack on a metallic test specimen. High-resolution images for the time-resolved ultrasonic field and time-averaged amplitude displacement are generated to understand the interaction of the wave with a surface-breaking fatigue crack. From the amplitude displacement data, three-dimensional surface contour plots of the wave energy are generated to find out how the elastic energy interacts with the tight fatigue crack interfaces. Results show that a tightly closed fatigue crack can transmit Rayleigh waves through the crack due to interfacial contact within the crack, where transmission of elastic energy was found to be more dominant towards the crack tip as expected. The sum of transmitted and reflected energy at the crack interface suggests that there is an additional energy loss mechanism which is proved experimentally by visualizing part of the incident Rayleigh wave energy propagating along the interfacial surfaces of the crack and continues its propagation along the surface of the opposite side of the test specimen.

Single-element interdigital transducers (IDTs) are designed, fabricated, and characterized as a complimentary sensor approach for traditional ultrasonic transducers used in nondestructive testing (NDT). The frequency of interest is in the lower megahertz range, 2–10 MHz. In this paper, a simple five-finger paired IDT is described, where laser micro-machining techniques were used to shape the electrode patterns for an IDT resonance frequency of ∼3 MHz. Detailed characterization of the Rayleigh surface waves generated by the IDT is performed using a scanning laser interferometry system. Wave properties such as beam profile, beam divergence, energy decay, frequency response, and phase dependence are reported.

Current Industry Code and Standard (ICS) Fitness for Service Assessment (FFSA) procedures for crack-like defect in weld area tend to impose high level of conservatism. In addition to the necessity for using conservative Welding Residual Stress (WRS) model due to the uncertainty inherent in the WRS estimation, using the original WRS regardless of crack depth in the crack driving force calculation, like the applied operating load, is the primary reason for this solution conservatism. In addition, current ICS weld area defect assessment procedures involve ambiguities in boundary condition effects on WRS models, as well as in the fracture mode of weld area crack being treated in the context of opening mode only, even though there is no weld area geometric symmetry essential for precluding fracture modes other than mode I. To clarify these technical issues in the ICS FFSA practices rigorous numerical simulation analyses of welding process and crack growth following joint fabrication have been performed, using the finite element analysis procedure. A crack driving force calculation procedure for weld area cracks, which was developed to quantify the crack extension effects on WRS for growing crack, was used for the finite element crack growth simulation analyses. The rigorous finite element analysis results for boundary condition effects on WRS, the fracture mode of weld toe crack, and crack growth effects on crack driving force parameters caused by WRS are compared with those of current ICS solutions. These comparisons demonstrate the need for an improvement of the current ICS FFSA procedures for weld area crack-like defects. The primary objective of the present paper is to motivate the industry to improve ICS FFSA procedures by clarifying these ambiguous technical issues in weld area crack-like defect assessment parameters, as well as considering crack extension effects on WRS properly in calculating the crack driving force of growing crack to reduce undue conservatism in FFSA.

Noncollinear beam mixing is an ultrasonic approach to quantify elastic nonlinearity within a subsurface volume of material. The technique requires interaction between two beams of specific frequency, angle, and vibration mode to generate a third beam propagating from the intersection volume. The subsurface depth to interaction zone is controlled by changing the separation distance between the two input transducers, and the amplitude of the third generated beam is proportional to the elastic nonlinearity within the interaction zone. Therefore, depth profiling is possible if a suitable parameter is established to normalize the detected signal independent of propagation distances and input amplitudes. This foundational effort has been conducted toward developing such a parameter for depth profile measurements in homogeneous aluminum that includes corrective terms for attenuation, beam overlap noise, beam spread, and input amplitudes. Experimental and analytical results are provided, and suggested applications and improvements are discussed toward characterizing subsurface material property profiles.

Advantages of two dimensional electronic ultrasonic beam focusing, steering and scanning with the matrix phased array (MPA) technology has been used to visualize the conditions of resistance spot welds in auto vehicle grade advanced high strength steel carbon steels nondestructively. Two of the commonly used joining techniques, resistance spot welding and resistance seam welding, for thin aerospace grade plates made of aluminum, titanium, and stainless steels have also been inspected with the same MPA NDE system. In this study, a detailed discussions of the current MPA based ultrasonic real time imaging methodology has been made followed by some of the NDT results obtained with various welded test coupons.

A three-dimensional MPA probe has been incorporated with a high speed phased array electronic board to visualize nugget images of resistance spot welds. The primary application area of this battery operated portable MPA ultrasonic imaging system is in the automotive industry which a conventional destructive testing process is commonly adopted to check the quality of resistance spot welds in auto bodies. Considering an average of five-thousand spot welds in a medium size passenger vehicle, the amount of time and effort given to popping the welds and measuring nugget size are immeasurable in addition to the millions of dollars' worth of scrap metals recycled per plant per year. This wasteful labor intensive destructive testing process has become less reliable as auto body sheet metal has transitioned from thick and heavy mild steels to thin and light high strength steels. Consequently, the necessity of developing a non-destructive inspection methodology has become inevitable. In this paper, the fundamental aspects of the current 3-D probe design, data acquisition algorithms, and weld nugget imaging process are discussed.

In the Oil and Gas industry, it is very common to make welds on pipes in the field. For straight pipes, most of the time, welds are inspected with an automated ultrasonic testing (AUT) system. However, pipes having non-traditional geometric constraints such as a slanted corrugation feature prohibit the use of an AUT method. As an effort to develop a field deployable in-situ weld inspection system, a high-speed MPA circuit board (purchased from Advanced OEM Solutions) has been used to drive a 32-element MPA probe operating at 3 MHz. The goal of the most recent phase of this development was to achieve a minimum of 200 inches per minute real-time inspection speed to match a welding process developed simultaneously at EWI. In order to meet the speed requirement, it was necessary to maximize the data acquisition rate as close as possible to the data transfer rate the MPA circuit board could support. A customized ultrasonic imaging algorithm developed using the Python programming language proved to be effective...

This study compared the clinical and radiologic outcomes of arthroscopic medial meniscus root refixation using the modified Mason-Allen stitch and simple stitches.The outcomes of 25 patients who underwent arthroscopic meniscus root refixation using the modified Mason-Allen stitch (M group) between June 2010 and January 2012 were compared with those of 25 matched control patients (S group) who underwent meniscus root refixation using simple stitches between March 2004 and August 2007. The Lysholm score, International Knee Documentation Committee Subjective Knee Form score, joint space narrowing, and Kellgren-Lawrence grade were assessed. Medial meniscal extrusion, progression of cartilage degeneration, and healing status of the refixed medial meniscus root were assessed on magnetic resonance images.No between-group difference was found in age, sex, body mass index, or preoperative patient characteristics. The mean follow-up times for the M and S groups were 24.1 and 25.9 months (P = .248), respectively. The Lysholm, International Knee Documentation Committee Subjective Knee Form, and Tegner activity scores improved significantly in both groups. The repaired root tended to heal better in the M group than in the S group (P = .065). Although the postoperative clinical outcomes did not differ between the groups, postoperative medial meniscal extrusion decreased -0.6 ± 0.9 mm in the M group and increased 1 ± 0.6 mm in the S group on magnetic resonance imaging (P.001). The M group did not show significant progression in the Kellgren-Lawrence grade and cartilage degeneration (P = .083 and P = .317, respectively), whereas both measures increased significantly in the S group (P = .008 and P.001, respectively).Compared with simple stitches, the modified Mason-Allen stitch improved the degree of meniscal extrusion, although the 2 different suture techniques showed no difference in clinical outcomes at short-term follow-up.Level III, retrospective comparative study.

High frequency matrix phased-array (MPA) probes have been designed and developed for more accurate and repeatable assessment of weld conditions of thin sheet metals commonly used in the auto industry. Unlike the line focused ultrasonic beam generated by a linear phased-array (LPA) probe, a MPA probe can form a circular shaped focused beam in addition to the typical beam steering capabilities of phased-array probes. A CIVA based modeling and simulation method has been used to design the probes in terms of various probe parameters such as number of elements, element size, overall dimensions, frequency etc. Challenges associated with the thicknesses of thin sheet metals have been resolved by optimizing these probe design parameters. A further improvement made on the design of the MPA probe proved that a three-dimensionally shaped matrix element can provide a better performing probe at a much lower probe manufacturing cost by reducing the total number of elements and lowering the operational frequency. This three dimensional probe naturally matches to the indentation shape of the weld on the thin sheet metals and hence a wider inspection area with the same level of spatial resolution obtained by a twodimensional flat MPA probe operating at a higher frequency. The two aspects, a wider inspection area and a lower probe manufacturing cost, make this three-dimensional MPA sensor more attractive to auto manufacturers demanding a quantitative nondestructive inspection method.

Small objects positioned in a high‐frequency ultrasonic beam can be imaged by Bragg diffraction of light. The first order contains one image. Using a light beam with a considerable convergence angle and reducing the ultrasonic frequency, one observes that the second diffraction order contains two adjoining images, the third order three, etc., and that the positive orders are the mirror images of the negative ones. These experimental observations are explained by the present theory and general expressions for the angular distribution of the light in the different diffraction orders are presented in the form of a series expansion. Evidence for the multiple images in the higher diffraction orders is found by analyzing the first term in this expansion. The center‐to‐center separation of the images within the higher orders is found to be proportional to the ultrasonic frequency and the interaction width.

Reliable structural integrity evaluation is a critical part of the design process. Reliable structural integrity evaluation is especially important for large and complex structures such as buildings and offshore/marine installations that have significant implications for human and environmental safety. The design and careful evaluation of welded structures are essential in structural design since the stress concentrations at the welds have significant impact on the overall fatigue lives of the structures. A mesh-insensitive structural stress method has been developed and proven to be highly effective in correlating fatigue behaviors of welded joints by Battelle researchers. The Battelle structural stress method and related weld fatigue master S-N curve approach has been adopted by ASME and API in 2007 [1–2]. The design fatigue master S-N curve has been constructed by incorporating the results of more than 800 fatigue tests, which are clearly categorized as weld toe failure. In addition, a design master S-N curve for weld root failure has been constructed recently [3]. For offshore/marine structures, it is essential to consider weld fatigue damage in corrosive environments as well as that in air, and to understand the effects of techniques commonly applied to improve weld fatigue strength of the structures, e.g., hammer peening, toe grinding, and TIG dressing. In order to meet the industry’s increasing demand for reliably, fatigue resistant structures, design master S-N curves incorporating the effects of corrosive environments and weld improvement techniques have been constructed. These new curves are based on existing weld fatigue data from the literature and class bodies’ fatigue design documents.

Thermal Protection Systems (TPS) can be subjected to impact damage during flight and/or during ground maintenance and/or repair. AFRL/RXLP is developing a reliable and robust on-board sensing/monitoring capability for next generation thermal protection systems to detect and assess impact damage. This study was focused on two classes of metallic thermal protection tiles to determine threshold for impact damage and develop sensing capability of the impacts. Sensors made of PVDF piezoelectric film were employed and tested to evaluate the detectability of impact signals and assess the onset or threshold of impact damage. Testing was performed over a range of impact energy levels, where the sensors were adhered to the back of the specimens. The PVDF signal levels were analyzed and compared to assess damage, where digital microscopy, visual inspection, and white light interferometry were used for damage verification. Based on the impact test results, an assessment of the impact damage thresholds for each type of metallic TPS system was made.

Durable integrated sensor systems are needed for long-term health monitoring evaluations of aerospace systems. For legacy aircraft the primary means of implementing a sensor system will be through surface mounting or bonding of the sensors to the structure. Previous work has shown that the performance of surface-bonded piezo sensors can degrade due to environmental effects such as vibrations, temperature fluctuations, and substrate flexure motions. This performance degradation included sensor cracking, disbonding, and general loss of efficiency over time. In this research effort, the bonding state of a piezo sensor system was systematically studied to understand and improve the long-term durability and survivability of the sensor system. Analytic and computational models were developed and used to understand elastic wave generation and reception performance for various states of sensor disbond. Experimental studies were also conducted using scanning laser vibrometry, pitch-catch ultrasound, and pulse-echo ultrasound methods to understand elastic wave propagation effects in thin plate materials. Significant performance loss was observed for increasing levels of sensor disbond as well as characteristic frequency signatures which may be useful in understanding sensor performance levels for future structural health monitoring systems.

Elastic waves generated by foreign materials impacting surfaces of aerospace vehicle can be used to detect and quantify the severity of damage. Passive acoustical emission sensors, made of piezoelectric elements, are typically used as impact signal detection devices. In this study, we have concentrated on characterizing the bonding qualities of piezoelectric sensors in terms of various bonding materials and adhesion conditions such as bond strength, bond stiffness, partial bonding, and disbonding. The experiment has been performed with an automated impact testing setup under controlled bonding and disbonding conditions in an attempt to establish a standardized sensor bond quality inspection methodology.

Background : Finding out the effective ways of teaching and assessing communication skills remain a challenging part of medication education. This study aims at exploring the usefulness and effectiveness of having additional feedback using qualitative analysis in assessment of communication skills in undergraduate medical training. We also determined the possibilities of using qualitative analysis in developing tailored strategies for improvement in communication skills training. Methods : This study was carried out on medical students ( n =87) undergoing their final year clinical performance examination on communication skills using standardized patient by video-recording and transcribing their performances. Video-recordings of 26 students were randomly selected for qualitative analysis, and additional feedback was provided. We assessed the level of acceptance of communication skills scores between the study and nonstudy group and within the study group, before and after receiving feedback based on qualitative analysis. Results : There was a statistically significant increase in the level of acceptance of feedback after delivering additional feedback using qualitative analysis, where the percentage of agreement with feedback increased from 15.4 to 80.8% ( p

OBJECTIVE To establish hazard ratios for risk of urinary stone formation in men with chronic spinal cord injury. PATIENTS AND METHODS In all, 140 men injured before 1987 were eligible for this investigation and were followed yearly from January 1987 and December 2003. RESULTS Over the 17 years, 39 patients (28%) and 21 (15%) were diagnosed with bladder and renal stones for a total of 59 and 25 episodes, respectively. In multivariate analysis, bladder stone was more common in patients injured when aged ≥ 24 years than in those injured when aged

An in-situ technique to measure sound velocity, ultrasonic attenuation and acoustic nonlinear property has been developed for characterization and early detection of fatigue damage in aerospace materials. For this purpose we have developed a computer software and measurement technique including hardware for the automation of the measurement. New transducer holder and special grips are designed. The automation has allowed us to test the long-term stability of the electronics over a period of time and so proof of the linearity of the system. Real-time monitoring of the material nonlinearity has been performed on dog-bone specimens from zero fatigue all the way to the final fracture under low-cycle fatigue test condition (LCF) and high-cycle test condition (HCF). Real-time health monitoring of the material can greatly contribute to the understanding of material behavior under cyclic loading. Interpretation of the results show that correlation exist between the slope of the curve described by the material nonlinearity and the life of the component. This new methodology was developed with an objective to predict the initiation of fatigue microcracks, and to detect, in-situ fatigue crack initiation as well as to quantify early stages of fatigue damage.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

An in-situ technique to measure sound velocity, ultrasonic attenuation and acoustic nonlinear property has been developed for characterization and early detection of fatigue damage in aerospace materials. A previous experiment using the f-2f technique on Ti-6Al-4V dog bone specimen fatigued at different stage of fatigue has shown that the material nonlinearity exhibit large change compared to the other ultrasonic parameter. Real-time monitoring of the nonlinearity may be a future tool to characterize early fatigue damage in the material. For this purpose we have developed a computer software and measurement technique including hardware for the automation of the measurement. New transducer holder and special grips are designed. The automation has allowed us to test the long-term stability of the electronics over a period of time and so proof of the linearity of the system. For the first time, a real-time experiment has been performed on a dog-bone specimen from zero fatigue al the way to the final fracture.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The fundamental cavity mode of a spot-_ size converted Fabry-Perot semiconductor laser is analyzed based on coupled local-mode theory. The analysis gives a new guideline on the design of spot-size converter integrated semiconductor lasers.

The assessment of pre-crack fatigue conditions is a problem of some importance in the nondestructive evaluation of turbine blades. Of particular concern to the electric power industry is the state of fatigue of steam driven stainless steel blades during the latter stages of service life prior to the nucleation of fatigue cracks. We report here measurements of acoustic attenuation, longitudinal velocity, and nonlinearity parameters on 410Cb stainless steel specimens provided by Virginia Power Company. Both virgin specimens and specimens from retired turbine blades were studied. From the virgin material a series of samples were prepared according to ASTM standards and cyclically fatigued from 0 to 10 million cycles at a tensile stress level of 85% of the yield strength of the material with an R value of zero. The results of the measurements are compared to that obtained from the retired turbine blade material.