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Sample records for bone thickness measurement

  1. Development of pulser/receiver for measuring the thickness of heel bone

    International Nuclear Information System (INIS)

    Ultrasound has been applied to the diagnosis of osteoporosis. Although several ultrasound devices have already been developed for bone covered with thin skin such as the calcaneus to predict failure risk of other bones, the precision of these ultrasonic methods can be adversely affected by the bone shape and inconsistent positioning. In this study, we developed a specially designed ultrasonic pulser/receiver for visualizing the bone quality and thickness simultaneously. The three dimensional image obtained from the data of quality and shape could allow better assessment of bone. The acrylic and bone specimens were used for evaluating performance of the pulser/receiver in the measurement of material quality and thickness. The results demonstrated that the method used in this study can be applied to the improvement of currently available ultrasound devices.

  2. Palatal bone thickness measured by palatal index method using cone-beam computed tomography in nonorthodontic patients for placement of mini-implants

    Directory of Open Access Journals (Sweden)

    W S Manjula

    2015-01-01

    Full Text Available Introduction: The purpose of this study was to compare the bone thickness of the palatal areas in different palatal index (PI groups. Materials and Methods: Cone-beam computed tomography scans of 10 subjects were selected with a mean age group of 18 years. The measurements of palatal bone thickness were made at 36 sites using CareStream 3D Imaging software. The PI was measured using Korkhaus ratio (palatal height/palatal width. One-way analysis of variance was used to analyze intergroup differences, as well as the PI difference. Results: Bone thickness was higher in the anterior region than in the middle and posterior regions P<0.001. Furthermore, significant differences were found among the midline, medial, and lateral areas of the palate. Conclusions: These findings might be helpful for clinicians to enhance the successful use of temporary anchorage devices in the palate.

  3. Development of a practical ultrasonic approach for simultaneous measurement of the thickness and the sound speed in human skull bones: a laboratory phantom study

    International Nuclear Information System (INIS)

    The availability of a non-invasive express method for the in vivo measurement of both sound velocity and thickness of the human skull bone would be of great benefit to various transcranial ultrasonic imaging and treatment applications. This paper investigates two ultrasonic methods that measure both parameters and are based on the variable focus technique. All the experiments described in this paper were conducted on specially prepared custom skull bone phantoms, including flat and deformed samples, designed and developed in our laboratory. The first method uses a single immersion 2.25 MHz ultrasonic transducer consecutively focused on the front and back surfaces of the sample. The accuracy and precision of this method are demonstrated via single point measurements on flat samples with and without porosity. The measurement results from a specimen with the randomly curved back surface show the possibility of obtaining the inner profile of the skull bone. The second presented method is a practical modification of the variable focus technique for the linear phased array case. The method was tested on flat and curved skull bone phantoms with and without inner porosity showing higher measurement accuracy and simpler practical realization than its scanning counterpart. (paper)

  4. Computed tomography analysis of guinea pig bone: architecture, bone thickness and dimensions throughout development

    Directory of Open Access Journals (Sweden)

    Agata Witkowska

    2014-10-01

    Full Text Available The domestic guinea pig, Cavia aperea f. porcellus, belongs to the Caviidae family of rodents. It is an important species as a pet, a source of food and in medical research. Adult weight is achieved at 8–12 months and life expectancy is ∼5–6 years. Our aim was to map bone local thickness, structure and dimensions across developmental stages in the normal animal. Guinea pigs (n = 23 that had died of natural causes were collected and the bones manually extracted and cleaned. Institutional ethical permission was given under the UK Home Office guidelines and the Veterinary Surgeons Act. X-ray Micro Computed Tomography (microCT was undertaken on the left and right scapula, humerus and femur from each animal to ascertain bone local thickness. Images were also used to undertake manual and automated bone measurements, volumes and surface areas, identify and describe nutrient, supratrochlear and supracondylar foramina. Statistical analysis between groups was carried out using ANOVA with post-hoc testing. Our data mapped a number of dimensions, and mean and maximum bone thickness of the scapula, humerus and femur in guinea pigs aged 0–1 month, 1–3 months, 3–6 months, 6 months–1 year and 1–4 years. Bone dimensions, growth rates and local bone thicknesses differed between ages and between the scapula, humerus and femur. The microCT and imaging software technology showed very distinct differences between the relative local bone thickness across the structure of the bones. Only one bone showed a singular nutrient foramen, every other bone had between 2 and 5, and every nutrient canal ran in an oblique direction. In contrast to other species, a supratrochlear foramen was observed in every humerus whereas the supracondylar foramen was always absent. Our data showed the bone local thickness, bone structure and measurements of guinea pig bones from birth to 4 years old. Importantly it showed that bone development continued after 1 year, the point

  5. WNT16 influences bone mineral density, cortical bone thickness, bone strength, and osteoporotic fracture risk.

    Directory of Open Access Journals (Sweden)

    Hou-Feng Zheng

    2012-07-01

    Full Text Available We aimed to identify genetic variants associated with cortical bone thickness (CBT and bone mineral density (BMD by performing two separate genome-wide association study (GWAS meta-analyses for CBT in 3 cohorts comprising 5,878 European subjects and for BMD in 5 cohorts comprising 5,672 individuals. We then assessed selected single-nucleotide polymorphisms (SNPs for osteoporotic fracture in 2,023 cases and 3,740 controls. Association with CBT and forearm BMD was tested for ∼2.5 million SNPs in each cohort separately, and results were meta-analyzed using fixed effect meta-analysis. We identified a missense SNP (Thr>Ile; rs2707466 located in the WNT16 gene (7q31, associated with CBT (effect size of -0.11 standard deviations [SD] per C allele, P = 6.2 × 10(-9. This SNP, as well as another nonsynonymous SNP rs2908004 (Gly>Arg, also had genome-wide significant association with forearm BMD (-0.14 SD per C allele, P = 2.3 × 10(-12, and -0.16 SD per G allele, P = 1.2 × 10(-15, respectively. Four genome-wide significant SNPs arising from BMD meta-analysis were tested for association with forearm fracture. SNP rs7776725 in FAM3C, a gene adjacent to WNT16, was associated with a genome-wide significant increased risk of forearm fracture (OR = 1.33, P = 7.3 × 10(-9, with genome-wide suggestive signals from the two missense variants in WNT16 (rs2908004: OR = 1.22, P = 4.9 × 10(-6 and rs2707466: OR = 1.22, P = 7.2 × 10(-6. We next generated a homozygous mouse with targeted disruption of Wnt16. Female Wnt16(-/- mice had 27% (P<0.001 thinner cortical bones at the femur midshaft, and bone strength measures were reduced between 43%-61% (6.5 × 10(-13bone strength, and risk of fracture.

  6. Accurate thickness measurement of graphene

    Science.gov (United States)

    Shearer, Cameron J.; Slattery, Ashley D.; Stapleton, Andrew J.; Shapter, Joseph G.; Gibson, Christopher T.

    2016-03-01

    Graphene has emerged as a material with a vast variety of applications. The electronic, optical and mechanical properties of graphene are strongly influenced by the number of layers present in a sample. As a result, the dimensional characterization of graphene films is crucial, especially with the continued development of new synthesis methods and applications. A number of techniques exist to determine the thickness of graphene films including optical contrast, Raman scattering and scanning probe microscopy techniques. Atomic force microscopy (AFM), in particular, is used extensively since it provides three-dimensional images that enable the measurement of the lateral dimensions of graphene films as well as the thickness, and by extension the number of layers present. However, in the literature AFM has proven to be inaccurate with a wide range of measured values for single layer graphene thickness reported (between 0.4 and 1.7 nm). This discrepancy has been attributed to tip-surface interactions, image feedback settings and surface chemistry. In this work, we use standard and carbon nanotube modified AFM probes and a relatively new AFM imaging mode known as PeakForce tapping mode to establish a protocol that will allow users to accurately determine the thickness of graphene films. In particular, the error in measuring the first layer is reduced from 0.1-1.3 nm to 0.1-0.3 nm. Furthermore, in the process we establish that the graphene-substrate adsorbate layer and imaging force, in particular the pressure the tip exerts on the surface, are crucial components in the accurate measurement of graphene using AFM. These findings can be applied to other 2D materials.

  7. An Experimental Study of Radiographic Density of Alveolar Bone and Cortical Thickness of Mandible by Osteoporosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byeong Do [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Wonkwang University, Iksan (Korea, Republic of)

    2000-12-15

    To evaluate the effect of the systemic osteoporosis on radiographic density of alveolar bone and cortical thickness of mandible. The bone mineral density values of lumbar and femur were measured by dual-energy X-ray absorptiometry and T scores of lumbar, femur were obtained respectively. Radiographic densities of alveolar bones and panorama mandibular index (PMI, represents as cortical thickness) were analysed statistically according to age and T score variavles. The radiographic density of alveolar bone of maxillary molar showed significant difference by age and femur T group. That of mandibular molar showed significant difference between femur T group. Panorama mandibular index showed significant difference between age groups. The radiographic density of alvealar bones was more dependent on age femur T than lumbar T. Cortical thickness of mandible was correlated with increasing age.

  8. Assessment of the cortical bone thickness using ultrasonic guided waves: modelling and in vitro study.

    Science.gov (United States)

    Moilanen, Petro; Nicholson, Patrick H F; Kilappa, Vantte; Cheng, Sulin; Timonen, Jussi

    2007-02-01

    Determination of cortical bone thickness is warranted, e.g., for assessing the level of endosteal resorption in osteoporosis or other bone pathologies. We have shown previously that the velocity of the fundamental antisymmetric (or flexural) guided wave, measured for bone phantoms and bones in vitro, correlates with the cortical thickness significantly better than those by other axial ultrasound methods. In addition, we have introduced an inversion scheme based on guided wave theory, group velocity filtering and 2-D fast Fourier transform, for determination of cortical thickness from the measured velocity of guided waves. In this study, the method was validated for tubular structures by using numerical simulations and experimental measurements on tube samples. In addition, 40 fresh human radius specimens were measured. For tubes with a thin wall, plate theory could be used to determine the wall thickness with a precision of 4%. For tubes with a wall thicker than 1/5 of the outer radius, tube theory provided the wall thickness with similar accuracy. For the radius bone specimens, tube theory was used and the ultrasonically-determined cortical thickness was found to be U-Th = 2.47 mm +/- 0.66 mm. It correlated strongly (r(2) = 0.73, p < 0.001) with the average cortical thickness, C-Th = 2.68 +/- 0.53 mm, and the local cortical thickness (r(2) = 0.81, p < 0.001), measured using peripheral quantitative computed tomography. We can conclude that the guided-wave inversion scheme introduced here is a feasible method for assessing cortical bone thickness. PMID:17306696

  9. Computed tomography evaluation of human mandibles with regard to layer thickness and bone density of the cortical bone

    International Nuclear Information System (INIS)

    Application of function-restoring individual implants for the bridging of defects in mandibles with continuity separation requires a stable fixation with special use of the cortical bone stumps. Five section planes each of 100 computed tomographies of poly-traumatized patients' jaws were used for measuring the thickness of the cortical layer and the bone density of the mandible. The CT scans of 28 female and 72 male candidates aged between 12 and 86 years with different dentition of the mandible were available. The computed tomographic evaluations of human mandibles regarding the layer thickness of the cortical bone showed that the edge of the mandible in the area of the horizontal branch possesses the biggest layer thickness of the whole of the lower jaws. The highest medians of the cortical bone layer thickness were found in the area of the molars and premolars at the lower edge of the lower jaws in 6-o'clock position, in the area of the molars in the vestibular cranial 10-o'clock position and in the chin region lingual-caudal in the 4-o'clock position. The measurement of the bone density showed the highest values in the 8-o'clock position (vestibular-caudal) in the molar region in both males and females. The average values available of the bone density and the layer thickness of the cortical bone in the various regions of the lower jaw, taking into consideration age, gender and dentition, are an important aid in practice for determining a safe fixation point for implants in the area of the surface layer of the mandible by means of screws or similar fixation elements. (orig.)

  10. Thickness and uniformity measurements of nuclear targets

    International Nuclear Information System (INIS)

    This paper introduces the methods of target thickness and uniformity measurements including weighing, α-particle thickness gauge, quartz thickness gauge, optical transmittance and Rutherford backscattering. An α-particle gauging which measures target thicknesses up to several μm is metioned. A fast thickness measurements for C, Au and Cu targets by spectrophotometer is given. A high sensitive quartz gauge which can measure minimum deposit of 0.04 μg/cm2 is described. Thickness and impurity determinations by RBS with accuracy better than 5% are summarized

  11. Radiation transmission pipe thickness measurement system

    International Nuclear Information System (INIS)

    Fuji Electric Systems can be measured from the outer insulation of the transmission Characteristics and radiation detection equipment had been developed that can measure pipe wall thinning in plant and running, the recruitment of another three-beam calculation method by pipe thickness measurement system was developed to measure the thickness of the pipe side. This equipment has been possible to measure the thickness of the circumferential profile of the pipe attachment by adopting automatic rotation. (author)

  12. Eddy current thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, Gary J.; Sinclair, Frank; Soskov, Alexander; Buff, James S.

    2015-06-16

    A sheet of a material is disposed in a melt of the material. The sheet is formed using a cooling plate in one instance. An exciting coil and sensing coil are positioned downstream of the cooling plate. The exciting coil and sensing coil use eddy currents to determine a thickness of the solid sheet on top of the melt.

  13. Ultrasonic wall thickness measurement without coupling liquid

    International Nuclear Information System (INIS)

    If the material measured is part of the ultrasonic transducer, then one can do without the usual coupling liquid for ultrasonic measurement of wall thickness. Measuring equipment works on the basis of this electro-dynamic ultrasonic transducer, which has been developed to check the wall thickness (3 to 30 mm) of steel pipes with outside diameters of 25 to 180 mm. Double errors and local changes of wall thickness can be detected. (orig.)

  14. The evaluation of palatal bone thickness for implant insertion with cone beam computed tomography.

    Science.gov (United States)

    Sumer, A P; Caliskan, A; Uzun, C; Karoz, T B; Sumer, M; Cankaya, S

    2016-02-01

    The palate is an alternative anchoring site for orthodontic implants and screws. The use of osseointegrated implants in the intermaxillary suture has recently been described as a fast, effective, and low-cost technique for patients with atrophy of the maxillae. The aim of this study was to use cone beam computed tomography (CBCT) to evaluate the thickness of the bone surrounding the intermaxillary suture in relation to the insertion of osseointegrated implants. CBCT images of 144 patients (72 males, 72 females) aged 35-86 years were evaluated. The vertical bone height of the intermaxillary suture was measured using coronal and sagittal Images 5, 10, 15, 20, and 25 mm posterior to the incisive foramen. The mean bone thicknesses from the anterior to the posterior region were 5.59, 4.38, 3.91, 3.95, and 3.94 mm, respectively. Bone thickness was significantly different among the five anteroposterior areas of the suture, but there were no significant differences between males and females, or among age groups. The highest part of the intermaxillary suture was in the anterior region. Three-dimensional imaging is recommended to accurately identify palate bone thickness for implant placement. PMID:26458537

  15. Effect of Cortical Bone Thickness on Detection of Intraosseous Lesions by Ultrasonography

    International Nuclear Information System (INIS)

    Background. Usefulness of ultrasound (US) in detection of intrabony lesions has been showed. A cortical bone perforation or a very thin and intact cortical bone is prerequisite for this purpose. Objective. The current in vitro study was aimed at measuring the cut-off thickness of the overlying cortical bone which allows ultrasonic assessment of bony defects. Materials and Methods. 20 bovine scapula blocks were obtained. Samples were numbered from 1 to 20. In each sample, 5 artificial lesions were made. The lesions were made in order to increase the overlying bone thickness, from 0.1 mm in the first sample to 2 mm in the last one (with 0.1 mm interval). After that, the samples underwent ultrasound examinations by two practicing radiologists. Results. All five lesions in samples numbered 1 to 11 were detected as hypoechoic area. Cortical bone thickness more than 1.1 mm resulted in a failure in the detection of central lesions. Conclusion. We can conclude that neither bony perforation nor very thin cortical bones are needed to consider US to be an effective imaging technique in the evaluation of bony lesion

  16. Effect of Cortical Bone Thickness on Detection of Intraosseous Lesions by Ultrasonography

    Directory of Open Access Journals (Sweden)

    Sadaf Adibi

    2015-01-01

    Full Text Available Background. Usefulness of ultrasound (US in detection of intrabony lesions has been showed. A cortical bone perforation or a very thin and intact cortical bone is prerequisite for this purpose. Objective. The current in vitro study was aimed at measuring the cut-off thickness of the overlying cortical bone which allows ultrasonic assessment of bony defects. Materials and Methods. 20 bovine scapula blocks were obtained. Samples were numbered from 1 to 20. In each sample, 5 artificial lesions were made. The lesions were made in order to increase the overlying bone thickness, from 0.1 mm in the first sample to 2 mm in the last one (with 0.1 mm interval. After that, the samples underwent ultrasound examinations by two practicing radiologists. Results. All five lesions in samples numbered 1 to 11 were detected as hypoechoic area. Cortical bone thickness more than 1.1 mm resulted in a failure in the detection of central lesions. Conclusion. We can conclude that neither bony perforation nor very thin cortical bones are needed to consider US to be an effective imaging technique in the evaluation of bony lesion.

  17. Ice thickness measurements by Raman scattering

    CERN Document Server

    Pershin, Sergey M; Klinkov, Vladimir K; Yulmetov, Renat N; Bunkin, Alexey F

    2014-01-01

    A compact Raman LIDAR system with a spectrograph was used for express ice thickness measurements. The difference between the Raman spectra of ice and liquid water is employed to locate the ice-water interface while elastic scattering was used for air-ice surface detection. This approach yields an error of only 2 mm for an 80-mm-thick ice sample, indicating that it is promising express noncontact thickness measurements technique in field experiments.

  18. Practical considerations in ultrasonic wall thickness measurement

    International Nuclear Information System (INIS)

    Ultrasonic inspection is widely used by industry for the detection of corrosion and the measurement of material wall thickness. Due to wall thinning and the various forms of corrosion that can be found in pressure piping and pressure vessels the annual cost of corrosion damage and related service failures, is very expensive. The author interest is primarily in the examination of personnel who need to become competent and certificated in the various skills that are required to carry out wall thickness measurement and detection of wall thinning due to corrosion. The various techniques and equipment available for ultrasonic wall thickness measurement and assessment give rise to problems regarding the accuracy of results and detection of corrosion. This paper will discuss some of the corrosion conditions that may occur and also problems that may arise during wall thickness measurement. Methods of improving the wall thickness measurement and the assessment process will also be discussed. (author)

  19. Simultaneous assessment of bone thickness and velocity for ultrasonic computed tomography using transmission-echo method

    OpenAIRE

    Zheng, Rui; Lasaygues, Philippe

    2013-01-01

    The robustness and accuracy of the transmissionecho (TE) method is investigated on simultaneous thickness and velocity estimation of double-layered thin bone samples. Twentytwo pairs of bovine cortical samples were assembled and measured by two pairs of immersion transducers with nominal frequencies of 1MHz and 2.25MHz. For each measurement, the TOF of six pulses contained by one transmission and two echo signals were detected and then used for the calculation. The mean relative errors of eff...

  20. Card controlled beta backscatter thickness measuring instrument

    International Nuclear Information System (INIS)

    An improved beta backscatter instrument for the nondestructive measurement of the thickness of thin coatings on a substrate is described. Included therein is the utilization of a bank of memory stored data representative of isotope, substrate, coating material and thickness range characteristics in association with a control card having predetermined indicia thereon selectively representative of a particular isotope, substrate material, coating material and thickness range for conditioning electronic circuit means by memory stored data selected in accord with the predetermined indicia on a control card for converting backscattered beta particle counts into indicia of coating thickness

  1. Computed tomography analysis of guinea pig bone: architecture, bone thickness and dimensions throughout development.

    OpenAIRE

    Agata Witkowska; Aziza Alibhai; Chloe Hughes; Jennifer Price; Karl Klisch; Sturrock, Craig J.; Rutland, Catrin S.

    2014-01-01

    The domestic guinea pig, Cavia aperea f. porcellus, belongs to the Caviidae family of rodents. It is an important species as a pet, a source of food and in medical research. Adult weight is achieved at 8–12 months and life expectancy is ∼5–6 years. Our aim was to map bone local thickness, structure and dimensions across developmental stages in the normal animal. Guinea pigs (n = 23) that had died of natural causes were collected and the bones manually extracted and cleaned. Institutional ethi...

  2. A cone-beam computed tomography evaluation of buccal bone thickness following maxillary expansion

    International Nuclear Information System (INIS)

    This study was performed to determine the buccal alveolar bone thickness following rapid maxillary expansion (RME) using cone-beam computed tomography (CBCT). Twenty-four individuals (15 females, 9 males; 13.9 years) that underwent RME therapy were included. Each patient had CBCT images available before (T1), after (T2), and 2 to 3 years after (T3) maxillary expansion therapy. Coronal multiplanar reconstruction images were used to measure the linear transverse dimensions, inclinations of teeth, and thickness of the buccal alveolar bone. One-way ANOVA analysis was used to compare the changes between the three times of imaging. Pairwise comparisons were made with the Bonferroni method. The level of significance was established at p<0.05. The mean changes between the points in time yielded significant differences for both molar and premolar transverse measurements between T1 and T2 (p<0.05) and between T1 and T3 (p<0.05). When evaluating the effect of maxillary expansion on the amount of buccal alveolar bone, a decrease between T1 and T2 and an increase between T2 and T3 were found in the buccal bone thickness of both the maxillary first premolars and maxillary first molars. However, these changes were not significant. Similar changes were observed for the angular measurements. RME resulted in non-significant reduction of buccal bone between T1 and T2. These changes were reversible in the long-term with no evident deleterious effects on the alveolar buccal bone.

  3. A cone-beam computed tomography evaluation of buccal bone thickness following maxillary expansion

    Energy Technology Data Exchange (ETDEWEB)

    Akyalcin, Sercan; Englih, Jeryl D.; Stephens, Claude R.; Winkelmann, Sam [Dept. of Orthodontics, School of Dentistry, University of Texas Health Science Center at Houston, Houston (United States); Schaefer, Jeffrey S. [Todd Hughes Orthodontics, Houston (United States)

    2013-06-15

    This study was performed to determine the buccal alveolar bone thickness following rapid maxillary expansion (RME) using cone-beam computed tomography (CBCT). Twenty-four individuals (15 females, 9 males; 13.9 years) that underwent RME therapy were included. Each patient had CBCT images available before (T1), after (T2), and 2 to 3 years after (T3) maxillary expansion therapy. Coronal multiplanar reconstruction images were used to measure the linear transverse dimensions, inclinations of teeth, and thickness of the buccal alveolar bone. One-way ANOVA analysis was used to compare the changes between the three times of imaging. Pairwise comparisons were made with the Bonferroni method. The level of significance was established at p<0.05. The mean changes between the points in time yielded significant differences for both molar and premolar transverse measurements between T1 and T2 (p<0.05) and between T1 and T3 (p<0.05). When evaluating the effect of maxillary expansion on the amount of buccal alveolar bone, a decrease between T1 and T2 and an increase between T2 and T3 were found in the buccal bone thickness of both the maxillary first premolars and maxillary first molars. However, these changes were not significant. Similar changes were observed for the angular measurements. RME resulted in non-significant reduction of buccal bone between T1 and T2. These changes were reversible in the long-term with no evident deleterious effects on the alveolar buccal bone.

  4. Model SH intelligent instrument for thickness measuring

    International Nuclear Information System (INIS)

    The authors introduce Model SH Intelligent Instrument for thickness measuring by using principle of beta back-scattering and its application range, features, principle of operation, system design, calibration and specifications

  5. Greenland Radar Ice Sheet Thickness Measurements

    Data.gov (United States)

    National Aeronautics and Space Administration — Two 150-MHz coherent radar depth sounders were developed and flown over the Greenland ice sheet to obtain ice thickness measurements in support of PARCA...

  6. Vitamin D, carotid intima-media thickness and bone structure in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    K., Winckler; L., Tarnow; L., Lundby-Christensen; T.P., Almdal; N., Wiinberg; Eiken, P; T.W., Boesgaard; S.S., Lund; H., Perrild; T., Krarup; O., Snorgaard; B., Gade-Rasmussen; S., Madsbad; M., Roder; B., Thorsteinsson; E.R., Mathiesen; T., Jensen; H., Vestergaard; O., Pedersen; C., Hedetoft; L., Breum; E., Duun; S.B., Sneppen; B., Hemmingsen; C., Gluud; J., Wetterslev; A., Vaag

    2015-01-01

    Despite aggressive treatment of cardiovascular disease (CVD) risk factors individuals with type 2 diabetes (T2D) still have increased risk of cardiovascular morbidity and mortality. The primary aim of this study was to examine the cross-sectional association between total (25-hydroxy vitamin D (25...... diabetes 12+/-6 years), including 294 patients (71%) treated with insulin. Carotid intima-media thickness (IMT) and arterial stiffness (carotid artery distensibility coefficient (DC) and Young's elastic modulus (YEM)) were measured by ultrasound scan as indicators of CVD. Bone health was assessed by bone...

  7. Laser differential confocal lens thickness measurement

    International Nuclear Information System (INIS)

    Based on the property that the absolute zero of an axial intensity curve exactly corresponds to the focus of the objective in a differential confocal system (DCS), a new laser differential confocal lens thickness measurement is proposed to achieve the high-precision non-contact measurement of lens thickness. The proposed approach uses the absolute zero of DCS axial response curve to precisely identify the vertexes of the test lens, obtains the central optical thickness of the test lens, and then uses the radius of curvature and refractive index of the test lens and the ray tracing facet iterative calculation to obtain the central geometrical thickness of the test lens. The theoretical analyses and preliminary experiments indicate that the measurement accuracy is better than 0.03%. (paper)

  8. Uncertainty estimation of ultrasonic thickness measurement

    International Nuclear Information System (INIS)

    The most important factor that should be taken into consideration when selecting ultrasonic thickness measurement technique is its reliability. Only when the uncertainty of a measurement results is known, it may be judged if the result is adequate for intended purpose. The objective of this study is to model the ultrasonic thickness measurement function, to identify the most contributing input uncertainty components, and to estimate the uncertainty of the ultrasonic thickness measurement results. We assumed that there are five error sources significantly contribute to the final error, these sources are calibration velocity, transit time, zero offset, measurement repeatability and resolution, by applying the propagation of uncertainty law to the model function, a combined uncertainty of the ultrasonic thickness measurement was obtained. In this study the modeling function of ultrasonic thickness measurement was derived. By using this model the estimation of the uncertainty of the final output result was found to be reliable. It was also found that the most contributing input uncertainty components are calibration velocity, transit time linearity and zero offset. (author)

  9. Glue Film Thickness Measurements by Spectral Reflectance

    Energy Technology Data Exchange (ETDEWEB)

    B. R. Marshall

    2010-09-20

    Spectral reflectance was used to determine the thickness of thin glue layers in a study of the effect of the glue on radiance and reflectance measurements of shocked-tin substrates attached to lithium fluoride windows. Measurements based on profilometry of the components were found to be inaccurate due to flatness variations and deformation of the tin substrate under pressure during the gluing process. The accuracy of the spectral reflectance measurements were estimated to be ±0.5 μm, which was sufficient to demonstrate a convincing correlation between glue thickness and shock-generated light.

  10. Glue Film Thickness Measurements by Spectral Reflectance

    International Nuclear Information System (INIS)

    Spectral reflectance was used to determine the thickness of thin glue layers in a study of the effect of the glue on radiance and reflectance measurements of shocked-tin substrates attached to lithium fluoride windows. Measurements based on profilometry of the components were found to be inaccurate due to flatness variations and deformation of the tin substrate under pressure during the gluing process. The accuracy of the spectral reflectance measurements were estimated to be ±0.5 (micro)m, which was sufficient to demonstrate a convincing correlation between glue thickness and shock-generated light.

  11. Bone Mass Measurement: What the Numbers Mean

    Science.gov (United States)

    ... supported by your browser. Home Bone Basics Bone Mass Measurement: What the Numbers Mean Publication available in: ... been one or more osteoporotic fractures. Low Bone Mass Versus Osteoporosis The information provided by a BMD ...

  12. Simultaneous estimation of cortical bone thickness and acoustic wave velocity using a multivariable optimization approach: Bone phantom and in-vitro study.

    Science.gov (United States)

    Tasinkevych, Yuriy; Podhajecki, Jerzy; Falińska, Katarzyna; Litniewski, Jerzy

    2016-02-01

    The paper presents a method that allows the thickness of a compact bone layer and longitudinal wave velocity in the bone to be determined simultaneously with the use of reflected waves, with particular emphasis on the case of layers when the propagation time through the layer is shorter than the time duration of the interrogating pulse. The proposed method estimates simultaneously the thickness of the cortical bone layer and acoustic wave velocity by fitting the temporal spectrum of the simulated reflected wave to the spectrum of the reflected wave measured experimentally. For the purpose of echo-simulations the model of "soft tissue - compact bone layer - cancellous bone" was developed. Next, the cost function was defined as the least square error between the measured and simulated temporal spectra. Minimization of the cost function allowed us to determine the values of the parameters of the cortical bone layer which best fitted the measurements. To solve the optimization problem a simulated annealing algorithm was used. The method was tested using acoustic data obtained at the frequency of 0.6 MHz and 1 MHz respectively for a custom designed bone mimicking phantom and a calf femur. For the cortical shell of the calf femur whose thickness varies from 2.1 mm to 2.4 mm and velocity of 2910 m/s, the relative errors of the thickness estimation ranged from 0.4% to 5.5%. The corresponding error of the acoustic wave velocity estimation in the layer was 3.1%. In the case of artificial bone the thickness of the cortical layer was equal to 1.05 and 1.2 mm and acoustic wave velocity was 2900 m/s. These parameters were determined with the errors ranging from 1.9% to 10.8% and from 3.9% to 4.5% respectively. PMID:26522955

  13. Bone thickness of the infrazygomatic crest area in skeletal Class III growing patients: A computed tomographic study

    International Nuclear Information System (INIS)

    This study was performed to investigate the bone thickness of the infrazygomatic crest area by computed tomography (CT) for placement of a miniplate as skeletal anchorage for maxillary protraction in skeletal Class III children. CT images of skeletal Class III children (7 boys, 9 girls, mean age: 11.4 years) were taken parallel to the Frankfurt horizontal plane. The bone thickness of the infrazygomatic crest area was measured at 35 locations on the right and left sides, perpendicular to the bone surface. The bone was thickest (5.0 mm) in the upper zygomatic bone and thinnest (1.1 mm) in the anterior wall of the maxillary sinus. Generally, there was a tendency for the bone to be thicker at the superior and lateral area of the zygomatic process of the maxilla. There was no clinically significant difference in bone thickness between the right and left sides; however, it was thicker in male than in female subjects. In the infrazygomatic crest area, the superior and lateral area of the zygomatic process of the maxilla had the most appropriate thickness for placement of a miniplate in growing skeletal Class III children with a retruded maxilla.

  14. Bone thickness of the infrazygomatic crest area in skeletal Class III growing patients: A computed tomographic study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyub Soo; Choi, Hang Moon; Choi, Dong Soon; Jang, Insan; Cha, Bong Kuen [College of Dentistry and Research Institute of Oral Science, Gangneung-Wonju National University, Gangneung (Korea, Republic of)

    2013-12-15

    This study was performed to investigate the bone thickness of the infrazygomatic crest area by computed tomography (CT) for placement of a miniplate as skeletal anchorage for maxillary protraction in skeletal Class III children. CT images of skeletal Class III children (7 boys, 9 girls, mean age: 11.4 years) were taken parallel to the Frankfurt horizontal plane. The bone thickness of the infrazygomatic crest area was measured at 35 locations on the right and left sides, perpendicular to the bone surface. The bone was thickest (5.0 mm) in the upper zygomatic bone and thinnest (1.1 mm) in the anterior wall of the maxillary sinus. Generally, there was a tendency for the bone to be thicker at the superior and lateral area of the zygomatic process of the maxilla. There was no clinically significant difference in bone thickness between the right and left sides; however, it was thicker in male than in female subjects. In the infrazygomatic crest area, the superior and lateral area of the zygomatic process of the maxilla had the most appropriate thickness for placement of a miniplate in growing skeletal Class III children with a retruded maxilla.

  15. Measuring Thicknesses With In Situ Ultrasonic Transducers

    Science.gov (United States)

    Dunn, Daniel E.; Cerino, Joseph R.

    1995-01-01

    Several pulsed ultrasonic transducers attached to workpiece for measurement of changes in thicknesses of workpiece at transducer locations during grinding and polishing, according to proposal. Once attached, each transducer remains attached at original position until all grinding and polishing operations complete. In typical application, workpiece glass or ceramic blank destined to become component of optical system.

  16. Assessing the cortical thickness of long bone shafts in children, using two-dimensional ultrasonic diffraction tomography

    OpenAIRE

    Lasaygues, Philippe

    2006-01-01

    Echography is one of the first-line techniques used in clinical practice to diagnose osteoarticular diseases in children. However, this technique involves the use of standard equipment, which is not adapted to the morphology or the acoustical properties of children's bones. In this study, we developed an ultrasonic tomography method for measuring the cortical thickness of children's long bones. Ultrasonic tomography gives cross-sectional images showing the spatial distribution of some of the ...

  17. Visceral fat is more important than peripheral fat for endometrial thickness and bone mass in healthy postmenopausal women

    DEFF Research Database (Denmark)

    Warming, Lise; Ravn, Pernille; Christiansen, Claus

    2003-01-01

    as double-layer thickness. Body composition was measured by dual energy x-ray absorptiometry, which divides the body into fat mass, lean mass, and bone mass, both for the total body and regional body compartments. An abdominal region was inserted manually. Statistics were Pearson correlations and...... analysis of variance. RESULTS: Endometrial thickness and total body bone mass were correlated, respectively, to body mass index (r = 0.14, P <.01; r = 0.35, P <.001), total body fat mass (r = 0.14, P <.01; r = 0.38, P <.001), abdominal fat mass (r = 0.16, P <.001; r = 0.33, P <.001), peripheral fat mass (r...... = 0.10, P <.05; r = 0.41, P <.001), and abdominal/peripheral fat mass (r = 0.12, P <.01; r = 0.11, P <.01). CONCLUSION: High body mass index and abdominal fat distribution correlate with increased endometrial thickness and bone mass....

  18. Evaluation of cortical bone thickness of mandible with cone beam computed tomography for orthodontic mini implant installation

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Moslemzade

    2014-07-01

    Full Text Available Background: Achieving maximum anchorage without movement of the teeth in anchorage unit has been a great challenge in orthodontics and the success of the treatment plan highly depends on it. In this case, using orthodontic mini-implants can make a huge difference. The objective of this retrospective study was to measure thickness of cortical bone at prospective mini-implant placement sites in mandible in order to understand stability aspects of mini-implant placement by using cone-beam computed tomography (CBCT images.Materials and Methods: Initial 3-dimensional images of 40 adult patients were studied. The cortical bone thickness was obtained at the alveolar processes from canine to second molar at 5 different vertical levels from the cementoenamel junction (CEJ. To determine the cortical bone thickness, tangent lines were drawn buccolingually to the roots in axial section and a third line was drawn from the middle of these two lines, and the cortical bone thickness was measured where the third line crossed the buccal cortex. Results: Mandibular and buccal cortical bone thicknesses were 0.79 to 2.49 mm, respectively. There was a statistically significant increase from the CEJ to the apex (P<0.001, while this increase was not statically significant at interdental area of teeth #3 and #4. Comparing the 4 mm section in all sites showed significant increase from anterior to posterior.Conclusion: Based on our results, the cortical bone thickness mostly follows a pattern and depends on the interradicular site rather than individual differences.  Key words: Cone-beam computed tomography; orthodontic anchorage procedures

  19. Examination of thick-section confocal microscopy as a tool for the histomorphometric analysis of bone

    International Nuclear Information System (INIS)

    The authors have examined the potential utility of confocal microscopy as part of an effort to evaluate the deposition patterns of potentially interesting bone-seeking radiopharmaceuticals or toxic radioactive agents in Beagles and to characterize these patterns in a way that the radiation doses or toxic agent dosage delivered to the skeleton might be more easily modeled. In separate studies, they have looked at the deposition of 166Ho-labeled pharmaceuticals and found that their deposition patterns were amendable to description with the same models heretofore used for various bone-seeking radionuclides. In other work, they are examining the relationship in skeletal tissue between the apparent densities that can be obtained from computerized tomographic (CT) scanners and the direct measurement of mass via neutron activation analysis. The CT method has the potential advantage of reducing skeletal dissection effort and the capability of providing a record of macroscopic bone morphology down to a thickness of about 300-400 μm, and at the same time providing an index of surface-to-skeletal tissue mass ratios in bone. In this abstract, they describe efforts to employ a combination of confocal microscopy and ultra-milling technology to efficaciously address the biological issues and the technical difficulties that require acquisition of the multi-megabyte quantities of data and their storage

  20. Influence of Screw Length and Bone Thickness on the Stability of Temporary Implants

    OpenAIRE

    Daniel Jogaib Fernandes; Carlos Nelson Elias; Antônio Carlos de Oliveira Ruellas

    2015-01-01

    The purpose of this work was to study the influence of screw length and bone thickness on the stability of temporary implants. A total of 96 self-drilling temporary screws with two different lengths were inserted into polyurethane blocks (n = 66), bovine femurs (n = 18) and rabbit tibia (n = 12) with different cortical thicknesses (1 to 8 mm). Screws insertion in polyurethane blocks was assisted by a universal testing machine, torque peaks were collected by a digital torquemeter and bone thi...

  1. Orbital Emphysema Causing SyncopeChiari Malformation with Thick Occipital Bone

    OpenAIRE

    Yasuhara, Takao; Miyoshi, Yasuyuki; Date, Isao

    2011-01-01

    A case of a Chiari malformation with an extraordinarily thick occipital bone is described. The thick occipital bone might make the posterior fossa narrow with consequent herniation of the cerebellar tonsils to the foramen magnum and formation of a syrinx. At dural plasty, well-developed marginal and occipital sinuses should be deliberately handled with the preservation of normal venous drainage. This case gives us the essence of the occurrence mechanisms of Chiari malformation and foramen mag...

  2. Influence of Screw Length and Bone Thickness on the Stability of Temporary Implants

    Directory of Open Access Journals (Sweden)

    Daniel Jogaib Fernandes

    2015-09-01

    Full Text Available The purpose of this work was to study the influence of screw length and bone thickness on the stability of temporary implants. A total of 96 self-drilling temporary screws with two different lengths were inserted into polyurethane blocks (n = 66, bovine femurs (n = 18 and rabbit tibia (n = 12 with different cortical thicknesses (1 to 8 mm. Screws insertion in polyurethane blocks was assisted by a universal testing machine, torque peaks were collected by a digital torquemeter and bone thickness was monitored by micro-CT. The results showed that the insertion torque was significantly increased with the thickness of cortical bone from polyurethane (p < 0.0001, bovine (p = 0.0035 and rabbit (p < 0.05 sources. Cancellous bone improved significantly the mechanical implant stability. Insertion torque and insertion strength was successfully moduled by equations, based on the cortical/cancellous bone behavior. Based on the results, insertion torque and bone strength can be estimate in order to prevent failure of the cortical layer during temporary screw placement. The stability provided by a cortical thickness of 2 or 1 mm coupled to cancellous bone was deemed sufficient for temporary implants stability.

  3. New portable pipe wall thickness measuring technique

    Science.gov (United States)

    Pascente, Joseph E.

    1998-03-01

    One of the biggest inspection challenges facing many of the process industries; namely the petrochemical, refining, fossil power, and pulp and paper industries is: How to effectively examine their insulated piping? While there are a number of failure mechanisms involved in various process piping systems, piping degradation through corrosion and erosion are by far the most prevalent. This degradation can be in the form of external corrosion under insulation, internal corrosion through a variety of mechanisms, and internal erosion caused by the flow of the product through the pipe. Refineries, chemical plants and electrical power plants have MANY thousands of miles of pipe that are insulated to prevent heat loss or heat absorption. This insulation is often made up of several materials, with calcium based material being the most dense. The insulating material is usually wrapped with an aluminum or stainless steel outer wrap. Verification of wall thickness of these pipes can be accomplished by removing the insulation and doing an ultrasound inspection or by taking x- rays at a tangent to the edge of the pipe through the insulation. Both of these processes are slow and expensive. The time required to obtain data is measured in hours per meter. The ultrasound method requires that the insulation be plugged after the inspection. The surface needs to be cleaned or the resulting data will not be accurate. The tangent x-ray only shows two thicknesses and requires that the area be roped off because of radiation safety.

  4. The influence of fiber thickness, wall thickness and gap distance on the spiral nanofibrous scaffolds for bone tissue engineering

    International Nuclear Information System (INIS)

    We have developed a 3D nanofibrous spiral scaffold for bone tissue engineering which has shown enhanced cell attachment, proliferation and differentiation compared to traditional cylindrical scaffolds due to the spiral structures and the nanofiber incorporation. Some important parameters of these spiral scaffolds including gap distance, wall thickness and especially fiber thickness are crucial to the performance of the spiral structured scaffolds. In this study, we investigated the fiber thickness, gap distance and wall thickness of the spiral structure on the behavior of osteoblast cells. The human osteoblast cells are seeded on spiral structured scaffolds with various fiber thickness, gap distance and wall thickness and cell attachment, proliferation, differentiation and mineralized matrix deposition on the scaffolds are evaluated. It was found that increasing the thickness of nanofiber layer not only limited the cell infiltration into the scaffolds, but also restrained the osteoblastic cell phenotype development. Moreover, the geometric effect studies indicated that scaffolds with the thinner wall and gap distance 0.2 mm show the best bioactivity for osteoblasts.

  5. Parietal Bone Thickness and Vascular Diameters in Adult Modern Humans: A Survey on Cranial Remains.

    Science.gov (United States)

    Eisová, Stanislava; Rangel de Lázaro, Gizéh; Píšová, Hana; Pereira-Pedro, Sofia; Bruner, Emiliano

    2016-07-01

    Cranial bone thickness varies among modern humans, and many factors influencing this variability remain unclear. Growth hormones and physical activity are thought to influence the vault thickness. Considering that both systemic factors and energy supply influence the vascular system, and taking into account the structural and biomechanical interaction between endocranial vessels and vault bones, in this study we evaluate the correlation between vascular and bone diameters. In particular, we tested the relationship between the thickness of the parietal bone (which is characterized, in modern humans, by a complex vascular network) and the lumen size of the middle meningeal and diploic vessels, in adult modern humans. Our results show no patent correlation between the thickness of parietal bone and the size of the main vascular channels. Values and distributions of the branching patterns, as well as anatomical relationships between vessels and bones, are also described in order to provide information concerning the arrangement of the endocranial vascular morphology. This information is relevant in both evolutionary and medical contexts. Anat Rec, 299:888-896, 2016. © 2016 Wiley Periodicals, Inc. PMID:27072555

  6. Zirconium oxide layer thickness measurement by eddy current testing

    International Nuclear Information System (INIS)

    The oxide layer thickness on Zr-2 base can be measured by eddy current testing using lift-off effect. The value of oxide layer thickness measured by eddy current testing is comparable with that of metallography and weight gain value. The hydride concentration in the samples having different oxide layer thickness is different but the oxide layer thickness value measured by eddy current testing on different coupons was not affected by varying concentration of hydride

  7. Assessment of bone loss with repeated bone mineral measurements: Application to measurements on the individual patient

    International Nuclear Information System (INIS)

    Longitudinal measurements on lumbar spine and mid-radius were made by bone absorptiometry techniques in 139 normal women. Bone mineral was measured every 6 months over an median interval of 2.1 years. The results revealed that bone loss at different skeletal sites is non-uniform with equal bone loss patterns in all patients and relatively small variations in bone loss rate between normal women. For achieving these results there is strong demand on high precision and properly spaced measuring intervals for long-term rate of loss measurements. For exclusion of progressive degenerative disease a radiographic evaluation of the spine in the beginning and at the end of the study is mandatory as compression fractures or trauma reveal bone mineral changes independent from the agerelated bone loss. These repeated bone mineral measurements are useful for monitoring and follow-up studies during different therapeutic regimens. (orig.)

  8. Assessment of Corticotomy Facilitated Tooth Movement and Changes in Alveolar Bone Thickness - A CT Scan Study

    OpenAIRE

    Bhattacharya, Preeti; Bhattacharya, Hirak; Anjum, Arbab; Bhandari, Ravi; Agarwal, D. K.; Gupta, Ankur; Ansar, Juhi

    2014-01-01

    Introduction: Corticotomy is an effective method of accelerating the orthodontic treatment. The aim of this study was to compare the treatment time for the extraction space closure, between corticotomy assisted and conventional orthodontic tooth movement and to check the alveolar bone thickness before and after corticotomy procedure in the corticotomy group.

  9. Measurement Method of the Thickness Uniformity for Polymer Films

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Several methods for investigating the thickness uniformity of polymer thin films are presented as well as their measurement principles. A comparison of these experimental methods is given.The cylindrical lightwave reflection method is found to can obtain the thickness distribution along a certain direction.It is a simple and suitable method to evaluate the film thickness uniformity.

  10. Measuring the Thickness of a Transparent Ring with a Laser

    Science.gov (United States)

    Leung, Alfred F.

    2007-01-01

    There seems to be no reasonable way to measure the thickness of a narrow-mouth glass bottle. One can measure the outer and inner diameters of the mouth with a ruler or a pair of calipers and then calculate the thickness. However, this measurement might be interfered with by the threads at the mouth. Furthermore, it is uncertain whether the…

  11. Pelvic floor muscle thickness measured by perineal ultrasonography

    DEFF Research Database (Denmark)

    Bernstein, Inge Thomsen; Juul, N; Grønvall, S;

    1991-01-01

    Pelvic floor muscle thickness was assessed in nine healthy female physiotherapists by perineal sonography. All measurements were performed as triple-measurements. The aims were to assess the reliability of the measurements and to establish a reference material. The muscle thickness at rest and at...

  12. Pelvic floor muscle thickness measured by perineal ultrasonography

    DEFF Research Database (Denmark)

    Bernstein, Inge Thomsen; Juul, N; Grønvall, S;

    1991-01-01

    Pelvic floor muscle thickness was assessed in nine healthy female physiotherapists by perineal sonography. All measurements were performed as triple-measurements. The aims were to assess the reliability of the measurements and to establish a reference material. The muscle thickness at rest...

  13. Thickness measurement by using cepstrum ultrasonic signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Chul; Yoon, Chan Hoon; Choi, Heui Joo [Radioactive Waste Disposal Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Jong Sun [Chungnam National University, Daejeon (Korea, Republic of)

    2014-08-15

    Ultrasonic thickness measurement is a non-destructive method to measure the local thickness of a solid element, based on the time taken for an ultrasound wave to return to the surface. When an element is very thin, it is difficult to measure thickness with the conventional ultrasonic thickness method. This is because the method measures the time delay by using the peak of a pulse, and the pulses overlap. To solve this problem, we propose a method for measuring thickness by using the power cepstrum and the minimum variance cepstrum. Because the cepstrums processing can divides the ultrasound into an impulse train and transfer function, where the period of the impulse train is the traversal time, the thickness can be measured exactly. To verify the proposed method, we performed experiments with steel and, acrylic plates of variable thickness. The conventional method is not able to estimate the thickness, because of the overlapping pulses. However, the cepstrum ultrasonic signal processing that divides a pulse into an impulse and a transfer function can measure the thickness exactly.

  14. Thickness measurement by using cepstrum ultrasonic signal processing

    International Nuclear Information System (INIS)

    Ultrasonic thickness measurement is a non-destructive method to measure the local thickness of a solid element, based on the time taken for an ultrasound wave to return to the surface. When an element is very thin, it is difficult to measure thickness with the conventional ultrasonic thickness method. This is because the method measures the time delay by using the peak of a pulse, and the pulses overlap. To solve this problem, we propose a method for measuring thickness by using the power cepstrum and the minimum variance cepstrum. Because the cepstrums processing can divides the ultrasound into an impulse train and transfer function, where the period of the impulse train is the traversal time, the thickness can be measured exactly. To verify the proposed method, we performed experiments with steel and, acrylic plates of variable thickness. The conventional method is not able to estimate the thickness, because of the overlapping pulses. However, the cepstrum ultrasonic signal processing that divides a pulse into an impulse and a transfer function can measure the thickness exactly.

  15. The effects of bone density and crestal cortical bone thickness on micromotion and peri-implant bone strain distribution in an immediately loaded implant: a nonlinear finite element analysis

    Science.gov (United States)

    2016-01-01

    Purpose This study investigated the effects of bone density and crestal cortical bone thickness at the implant-placement site on micromotion (relative displacement between the implant and bone) and the peri-implant bone strain distribution under immediate-loading conditions. Methods A three-dimensional finite element model of the posterior mandible with an implant was constructed. Various bone parameters were simulated, including low or high cancellous bone density, low or high crestal cortical bone density, and crestal cortical bone thicknesses ranging from 0.5 to 2.5 mm. Delayed- and immediate-loading conditions were simulated. A buccolingual oblique load of 200 N was applied to the top of the abutment. Results The maximum extent of micromotion was approximately 100 μm in the low-density cancellous bone models, whereas it was under 30 μm in the high-density cancellous bone models. Crestal cortical bone thickness significantly affected the maximum micromotion in the low-density cancellous bone models. The minimum principal strain in the peri-implant cortical bone was affected by the density of the crestal cortical bone and cancellous bone to the same degree for both delayed and immediate loading. In the low-density cancellous bone models under immediate loading, the minimum principal strain in the peri-implant cortical bone decreased with an increase in crestal cortical bone thickness. Conclusions Cancellous bone density may be a critical factor for avoiding excessive micromotion in immediately loaded implants. Crestal cortical bone thickness significantly affected the maximum extent of micromotion and peri-implant bone strain in simulations of low-density cancellous bone under immediate loading. PMID:27382504

  16. Thickness measurement of A-1 reactor caisson tube walls

    International Nuclear Information System (INIS)

    The equipment is described of measuring the thickness of caisson pipes built in the Bohunice A-1 reactor. The pulse-type ultrasonic thickness gauge is based on the reflection method using the double probe. The measurement accuracy is 0.1 mm. (J.B.)

  17. Measurement of bone blood flow in sheep

    International Nuclear Information System (INIS)

    Bone blood flow in sheep tibia has been estimated via the measurement of the perfusion limited clearance of 41Ar from the bone mineral matrix following fast neutron activation of 44Ca. Tibia blood flows were estimated for the intact sheep, and after the installation of an intramedullary pressure tap to elevate bone marrow pressure by saline infusion. The results indicate that normal blood flow in the tibia is in the range of 1.1 to 3.7 ml/100ml-min in the intact animal and at normal marrow pressure. With an elevated intramedullary pressure of approximately 100 mmHg, the bone blood flow measured varied around 0.5 to 1.1 ml/100ml-min. 12 refs., 5 figs., 1 tab

  18. Ultrasonic metal sheet thickness measurement without prior wave speed calibration

    International Nuclear Information System (INIS)

    Conventional ultrasonic mensuration of sample thickness from one side only requires the bulk wave reverberation time and a calibration speed. This speed changes with temperature, stress, and microstructure, limiting thickness measurement accuracy. Often, only one side of a sample is accessible, making in situ calibration impossible. Non-contact ultrasound can generate multiple shear horizontal guided wave modes on one side of a metal plate. Measuring propagation times of each mode at different transducer separations, allows sheet thickness to be calculated to better than 1% accuracy for sheets of at least 1.5 mm thickness, without any calibration. (paper)

  19. Ultrasound settings significantly alter arterial lumen and wall thickness measurements

    OpenAIRE

    Green Daniel J; Reed Christopher J; Potter Kathleen; Hankey Graeme J; Arnolda Leonard F

    2008-01-01

    Abstract Background Flow-mediated dilation (FMD) and carotid intima-medial thickness (CIMT), measured by ultrasound, are widely used to test the efficacy of cardioprotective interventions. Although assessment methods vary, automated edge-detecting image analysis software is routinely used to measure changes in FMD and CIMT. We aimed to quantify the effect that commonly adjusted ultrasound settings have on arterial lumen and wall thickness measurements made with CIMT measurement software. Meth...

  20. Calibration of the ultrasonic lubricant-film thickness measurement technique

    Science.gov (United States)

    Zhang, Jie; Drinkwater, Bruce W.; Dwyer-Joyce, Rob S.

    2005-09-01

    This paper describes an experimental apparatus and procedure for the calibration of the ultrasonic lubricant-film thickness measurement technique. It also presents a study of the accuracy of the technique. The calibration apparatus is demonstrated on a three layer steel-mineral oil-steel system. This was chosen to be representative of a typical bearing system which is the industrial application of the technique. In such bearing systems the lubricant-film thickness typically ranges from 0.1 to 100 µm. The calibration apparatus uses a high precision piezoelectric displacement translator to controllably displace one of the steel surfaces relative to the other and hence alter the lubricant-film thickness by a known amount. Through-thickness resonant frequency measurements are then used to accurately measure a thick lubricant film (h > 10 µm). These resonant frequency measurements form the starting point of the calibration. The displacement translator is then used to reduce the lubricant-film thickness into the, more practically interesting, low micron range. In this range the amplitude of the measured reflection coefficient is used via a spring interface model to calculate the lubricant-film thickness. Issues of ultrasonic beam alignment and frequency of operation are discussed. A detailed study of the effect of reflection-coefficient errors on the resultant thickness measurement is presented. Practical guidelines for use of the calibration are then defined and calibration is demonstrated experimentally over the range 0.5-1.3 µm.

  1. Measurement of facial soft tissues thickness using 3D computed tomographic images

    International Nuclear Information System (INIS)

    To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. There were no statistically significant differences between the direct measurements and those using the 3D images(p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissue thickness more easily in forensic science and anthropology

  2. Foveal thickness after phacoemulsification as measured by optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Gerasimos Th Georgopoulos

    2008-08-01

    Full Text Available Gerasimos Th Georgopoulos, Dimitrios Papaconstantinou, Maria Niskopoulou, Marilita Moschos, Ilias Georgalas, Chrysanthi KoutsandreaGlaucoma Department, Medical School, Athens University, Athens, GreeceBackground: Despite a significant body of research, no consistency on postoperative foveal thickness as measured by optical coherence tomography (OCT, can be recorded. The purpose of our study was to evaluate the effect of uncomplicated cataract surgery in the thickness of the retina in the foveal area during the early postoperative period.Methods: In a prospective study, 79 eyes were assessed by OCT, on day 1, and weeks 2 and 4 after uncomplicated phacoemulsification with intraocular lens implantation in the Athens University Clinic. The outcome measure was the thickness of the retina in the foveal area.Results: The thickness of the retina preoperatively is significantly smaller (150.4 ± 18.8 (p < 0.05 than the thickness of the retina on day 1 (171.8 ± 21 and week 2 (159.7 ± 19 and returned to the initial levels on week 4 (152 ± 17.1. The estimated correlation coefficients between preoperative and postoperative thickness of the retina were significant (p < 0.05. Conversely, no association was found between postoperative visual acuity and thickness of the retina, neither between the phacoemulsification energy and retinal thickness. Operation time, although inversely related with postoperative visual acuity, was not associated with the thickness of the retina.Conclusions: Following phacoemulsification, an increase in the foveal thickness was detected in the early postoperative period, quantified and followed up by OCT. The foveal thickness returned to the preoperative level, 1 month following surgery in our study. No association was shown between intraoperative parameters and increased postoperative retinal thickness.Keywords: optical coherence tomography, phacoemulsification, retinal thickness

  3. Thin film thickness measurements using Scanning White Light Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Maniscalco, B.; Kaminski, P.M.; Walls, J.M., E-mail: J.M.Walls@lboro.ac.uk

    2014-01-01

    Scanning White Light Interferometry is a well-established technique for providing accurate surface roughness measurements and three dimensional topographical images. Here we report on the use of a variant of Scanning White Light Interferometry called coherence correlation interferometry which is now capable of providing accurate thickness measurements from transparent and semi-transparent thin films with thickness below 1 μm. This capability will have many important applications which include measurements on optical coatings, displays, semiconductor devices, transparent conducting oxides and thin film photovoltaics. In this paper we report measurements of thin film thickness made using coherence correlation interferometry on a variety of materials including metal-oxides (Nb{sub 2}O{sub 5} and ZrO{sub 2}), a metal-nitride (SiN{sub x}:H), a carbon-nitride (SiC{sub x}N{sub y}:H) and indium tin oxide, a transparent conducting oxide. The measurements are compared with those obtained using spectroscopic ellipsometry and in all cases excellent correlation is obtained between the techniques. A key advantage of this capability is the combination of thin film thickness and surface roughness and other three-dimensional metrology measurements from the same sample area. - Highlights: • Capability to make thin film measurements with sub-nanometre accuracy • Measurements of thin film thickness made on metal-oxides, nitrides and carbon-nitrides • Excellent correlation with thickness measurements using spectroscopic ellipsometry • Thin film measurement and nanometrology from the same sample area.

  4. Thin film thickness measurements using Scanning White Light Interferometry

    International Nuclear Information System (INIS)

    Scanning White Light Interferometry is a well-established technique for providing accurate surface roughness measurements and three dimensional topographical images. Here we report on the use of a variant of Scanning White Light Interferometry called coherence correlation interferometry which is now capable of providing accurate thickness measurements from transparent and semi-transparent thin films with thickness below 1 μm. This capability will have many important applications which include measurements on optical coatings, displays, semiconductor devices, transparent conducting oxides and thin film photovoltaics. In this paper we report measurements of thin film thickness made using coherence correlation interferometry on a variety of materials including metal-oxides (Nb2O5 and ZrO2), a metal-nitride (SiNx:H), a carbon-nitride (SiCxNy:H) and indium tin oxide, a transparent conducting oxide. The measurements are compared with those obtained using spectroscopic ellipsometry and in all cases excellent correlation is obtained between the techniques. A key advantage of this capability is the combination of thin film thickness and surface roughness and other three-dimensional metrology measurements from the same sample area. - Highlights: • Capability to make thin film measurements with sub-nanometre accuracy • Measurements of thin film thickness made on metal-oxides, nitrides and carbon-nitrides • Excellent correlation with thickness measurements using spectroscopic ellipsometry • Thin film measurement and nanometrology from the same sample area

  5. MRI evaluation of cranial bone marrow signal intensity and thickness in chronic anemia

    International Nuclear Information System (INIS)

    Background and purpose: The aim is to assess the magnetic resonance imaging (MRI) findings for cranial bone marrow (CBM) signal intensity and thickness in patients with chronic anemia and compared these with findings in healthy subjects. We also investigated the relationships between CBM changes and age, type of anemia (hemolytic versus non-hemolytic), and severity of anemia. Methods: We quantitatively evaluated CBM signal intensity and thickness on images from 40 patients with chronic anemia (20 with congenital hemolytic anemia (HA) and 20 with acquired anemia) and compared these to findings in 28 healthy subjects. The intensity of CBM relative to scalp, white matter (WM), gray matter (GM), and muscle intensity was also investigated in patients and subjects in the control group. The sensitivity and specificity of CBM hypointense to GM and CBM hypointense to WM as markers of anemia were evaluated. Relationships between age and CBM thickness/intensity, and between anemia severity (hemoglobin (Hb) level) and CBM thickness/intensity were evaluated. Results: Cranial bone marrow signal intensity was lower in the chronic anemia patients than in the controls (P0.05 for both). There were no correlations between age and CBM intensity or thickness, or between anemia severity and CBM intensity or thickness. Conclusion: Patients with chronic anemia exhibit lower CBM signal intensity on MRI than healthy subjects. Patients with hemolytic anemia have thicker CBM than patients with non-hemolytic anemia or healthy individuals. Decreased CBM intensity may indicate that the patient has anemia, and increased CBM thickness may specifically point to hemolytic anemia. These MRI findings may signal the need for further evaluation for the clinician

  6. Ultrasonic thickness measurement criteria in thinned pipe management program

    International Nuclear Information System (INIS)

    Credibility of thickness data is very important in the thinned pipe management program. This report presents following criteria; thickness measurement for each pipe component type, wear and wear rate calculation, and remaining service life assessment of thinned pipe component. And, the necessary items should be contained in the inspection report are presented

  7. Accurate wall thickness measurement using autointerference of circumferential Lamb wave

    International Nuclear Information System (INIS)

    In this paper, a method of accurately measuring the pipe wall thickness by using noncontact air-coupled ultrasonic transducer (NAUT) was presented. In this method, accurate measurement of angular wave number (AWN) is a key technique because the AWN is changes minutely with the wall thickness. An autointerference of the circumferential (C-) Lamb wave was used for accurate measurements of the AWN. Principle of the method was first explained. Modified method for measuring the wall thickness near a butt weld line was also proposed and its accuracy was evaluated within 6 μm error. It was also shown in the paper that wall thickness measurement was accurately carried out beyond the difference among the sensors by calibrating the frequency response of the sensors. (author)

  8. Measurement of choroidal thickness and macular thickness during and after pregnancy

    Institute of Scientific and Technical Information of China (English)

    D?ndü; Melek; Ulusoy; Necati; Duru; Mustafa; Atas; Hasan; Altιnkaynak; Zeynep; Duru; G?khan; A?maz

    2015-01-01

    AIM: To investigate the effect of pregnancy on subfoveal choroidal thickness(SFCT) and macular thickness in both pregnant and not pregnant healthy women.METHODS: Twenty-nine healthy pregnant women in their third trimester and 36 age-matched healthy women were enrolled in a prospective, cross-sectional study.Foveal and parafoveal thickness in the four quadrants and SFCT were measured by optical coherence tomography(OCT) in the healthy pregnant women(i.e.study group) and healthy women(i.e. control group).OCT measurements were again measured 3mo after delivery in the study group.RESULTS: Mean SFCT measurements in the control group, pregnant women of the study group, and after delivery of the study group were 320.86 ±59.18 μm,387.97 ±59.91 μm, and 332.40 ±26.03 μm, respectively.There was a statistically significant difference in the mean SFCT values between pregnant women of the study group and the control group(P =0.000). Foveal and parafoveal thickness values were not statistically significant in either the study or control group.CONCLUSION: SFCT increases during pregnancy and returns to normal range in the three months after delivery. Macular thickness does not show any change during pregnancy.

  9. On-Line thickness measurement in pipes by Gamma radiograph

    International Nuclear Information System (INIS)

    Corrosion in the pipes and remaining wall thickness measurements are the major concern in the piping service lifetime. Ultrasonic is the most common tool in measuring the wall thickness of the pipe. Although the test is relatively simple and fast, but this method is a local point determining method which requires removal of insulation and local surface preparation. Radiography methods (tangential and density evaluation ) are other techniques for thickness loss evaluation. In this investigation, the thickness profile of pipes, with 270 mm in diameter and 7.4-28.5 mm in thickness was determined by the radiograph density measurements nd the use of an Ir-192 gamma source. Some formulas were derived and suggested in this respect by considering the optical density of radiographs in different thicknesses and exposures. It was concluded that thickness loss of 10,20 and 50 percent of wall thickness, corrosion area and corrosion type in insulated and non-insulated gas carrying pipes can be detected by this method. Area of corrosion zone and corrosion type can also be shown in this technique

  10. Measurement of liquid crystal film thickness using interferometry

    International Nuclear Information System (INIS)

    Thickness measurements of thin films having thickness less than 1 µm are difficult to obtain by an interferometer. These difficulties arise from the overlap of the fringes from the upper and lower surfaces of the thin films. This paper presents a new methodology that mediates the consequences of this overlap and then implements it with thickness measurements of liquid crystal (LC) thin films. It takes into consideration the properties of light propagation within these films in order to rectify the images obtained from the interferometer. It assumes that the lower fringe pattern is much stronger that the upper one and hence the latter may be ignored. This occurs in situations where thin films are coated on substrates of significantly higher reflectivity, as happens when an LC thin film is coated on a polished iron substrate. The thickness and topography of LC thin films were experimentally measured with this methodology and were compared with measurements taken by an atomic force microscope

  11. Measuring Thicknesses Of Vacuum-Deposited Organic Thin Films

    Science.gov (United States)

    David, Carey E.

    1996-01-01

    Method of measuring thickness of thin organic liquid film deposited in vacuum involves use of quartz-crystal monitor (QCM) calibrated by use of witness plate that has, in turn, calibrated by measurement of absorption of infrared light in deposited material. Present procedure somewhat tedious, but once calibration accomplished, thicknesses of organic liquid deposits monitored in real time and in situ by use of QCM.

  12. Measurement of pipe wall local thickness by combined radiation method

    International Nuclear Information System (INIS)

    Analytical dependences have been studied which describe radiation fluxes registered by the respective detectors during transmission of a collimated beam of penetrating radiation through a tube over its diameter. The dependences are necessary for engineering designs, analysis of accuracy and other characteristics of radioisotope thickness gaUges using the combined method for measurements of tube wall local thickness. Experimental investigations have been carried out with 137Cs and 60Co sources. The dependence, permitting to determine conditions providing with the preset accuracy of tube wall local thickness measurement by the combined method, has been obtained

  13. Stress measurement in thick plates using nonlinear ultrasonics

    International Nuclear Information System (INIS)

    In this paper the interaction between nonlinear ultrasonic characteristics and stress state of complex loaded thick steel plates using fundamental theory of nonlinear ultrasonics is investigated in order to measure the stress state at a given cross section. The measurement concept is based on phased array placement of ultrasonic transmitter-receiver to scan three angles of a given cross section using Rayleigh waves. The change in the ultrasonic data in thick steel plates is influenced by normal and shear stresses; therefore, three measurements are needed to solve the equations simultaneously. Different thickness plates are studied in order to understand the interaction of Rayleigh wave penetration depth and shear stress. The purpose is that as the thickness becomes smaller, the shear stress becomes negligible at the angled measurement. For thicker cross section, shear stress becomes influential if the depth of penetration of Rayleigh wave is greater than the half of the thickness. The influences of plate thickness and ultrasonic frequency on the identification of stress tensor are numerically studied in 3D structural geometry and Murnaghan material model. The experimental component of this study includes uniaxial loading of the plate while measuring ultrasonic wave at three directions (perpendicular, parallel and angled to the loading direction). Instead of rotating transmitter-receiver pair for each test, a device capable of measuring the three angles is designed

  14. Computed tomography evaluation of human mandibles with regard to layer thickness and bone density of the cortical bone; Computertomografische Auswertung von humanen Unterkiefern hinsichtlich der Schichtstaerke und Knochendichte der Kortikalis

    Energy Technology Data Exchange (ETDEWEB)

    Markwardt, Jutta [TU Dresden Universitaetsklinikum (Germany). Klinik und Poliklinik fuer MKG-Chirurgie; Meissner, H.; Weber, A.; Reitemeier, B. [TU Dresden Universitaetsklinikum (Germany). Poliklinik fuer Zahnaerztliche Prothetik; Laniado, M. [TU Dresden Universitaetsklinikum (Germany). Inst. und Poliklinik fuer Radiologische Diagnostik

    2013-01-15

    Application of function-restoring individual implants for the bridging of defects in mandibles with continuity separation requires a stable fixation with special use of the cortical bone stumps. Five section planes each of 100 computed tomographies of poly-traumatized patients' jaws were used for measuring the thickness of the cortical layer and the bone density of the mandible. The CT scans of 28 female and 72 male candidates aged between 12 and 86 years with different dentition of the mandible were available. The computed tomographic evaluations of human mandibles regarding the layer thickness of the cortical bone showed that the edge of the mandible in the area of the horizontal branch possesses the biggest layer thickness of the whole of the lower jaws. The highest medians of the cortical bone layer thickness were found in the area of the molars and premolars at the lower edge of the lower jaws in 6-o'clock position, in the area of the molars in the vestibular cranial 10-o'clock position and in the chin region lingual-caudal in the 4-o'clock position. The measurement of the bone density showed the highest values in the 8-o'clock position (vestibular-caudal) in the molar region in both males and females. The average values available of the bone density and the layer thickness of the cortical bone in the various regions of the lower jaw, taking into consideration age, gender and dentition, are an important aid in practice for determining a safe fixation point for implants in the area of the surface layer of the mandible by means of screws or similar fixation elements. (orig.)

  15. Wide-Band Radar for Measuring Thickness of Sea Ice

    Science.gov (United States)

    Gogineni, Prasad; Kanagaratnam, Pannir; Holt, M.

    2008-01-01

    A wide-band penetrating radar system for measuring the thickness of sea ice is under development. The need for this or a similar system arises as follows: Spatial and temporal variations in the thickness of sea ice are important indicators of heat fluxes between the ocean and atmosphere and, hence, are important indicators of climate change in polar regions. A remote-sensing system that could directly measure the thickness of sea ice over a wide thickness range from aboard an aircraft or satellite would be of great scientific value. Obtaining thickness measurements over a wide region at weekly or monthly time intervals would contribute significantly to understanding of changes in the spatial distribution and of the mass balance of sea ice. A prototype of the system was designed on the basis of computational simulations directed toward understanding what signal frequencies are needed to satisfy partly competing requirements to detect both bottom and top ice surfaces, obtain adequate penetration despite high attenuation in the lossy sea-ice medium, and obtain adequate resolution, all over a wide thickness range. The prototype of the system is of the frequency-modulation, continuous-wave (FM-CW) type. At a given time, the prototype functions in either of two frequency-band/operational-mode combinations that correspond to two thickness ranges: a lower-frequency (50 to 250 MHz) mode for measuring thickness greater than about 1 m, and a higher frequency (300 to 1,300 MHz) mode for measuring thickness less than about 1 m. The bandwidth in the higher-frequency (lesser-thickness) mode is adequate for a thickness resolution of 15 cm; the bandwidth in the lower-frequency (greater-thickness) mode is adequate for a thickness resolution of 75 cm. Although a thickness resolution of no more than 25 cm is desired for scientific purposes, the 75-cm resolution was deemed acceptable for the purpose of demonstrating feasibility. The prototype was constructed as a modified version of a

  16. Using laser to measure stem thickness and cut weed stems

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Andreasen, C.; Christensen, S.

    2002-01-01

    Stem thickness of the weed Solanum nigrum and the crop sugarbeet was determined with a He-Ne laser using a novel non-destructive technique measuring stem shadow. Thereafter, the stems were cut close to the soil surface with a CO2 laser. Treatments were carried out on pot plants, grown in the...... greenhouse, at two different growth stages, and plant dry matter was measured 2-5 weeks after treatment. The relationship between plant dry weight and laser energy was analysed using two different non-linear dose-response regression models; one model included stem thickness as a variable, the other did not....... A binary model was also tested. The non-linear model incorporating stem thickness described the data best, indicating that it would be possible to optimize laser cutting by measuring stem thickness before cutting. The general tendency was that more energy was needed the thicker the stem. Energy uses...

  17. Methods for measuring bone tissue mineral status

    International Nuclear Information System (INIS)

    Advantages and disadvantages of different methods for measuring the bone tissue mineral content are considered. Radiogrammetry and radiographic densitometry (photodensitometry), one-photon absorptiometry, two-photon absorptiometry (TPA), computerized tomography (γ- and X-ray) are discussed. It was shown that computerized tomography was the most sensitive method though its cost and patient radiation doses were high. Two-photon bone densitometers (mainly based on 153Gd source) were most wide practised. Devices based in X-ray TPA supplant them lately. They are more complex in design but permit to reduce the time of examination due to increase in scanning rate and to improve the reproducibility. Moreover, they are ecologically pure

  18. Model-based cartilage thickness measurement in the submillimeter range

    International Nuclear Information System (INIS)

    Current methods of image-based thickness measurement in thin sheet structures utilize second derivative zero crossings to locate the layer boundaries. It is generally acknowledged that the nonzero width of the point spread function (PSF) limits the accuracy of this measurement procedure. We propose a model-based method that strongly reduces PSF-induced bias by incorporating the PSF into the thickness estimation method. We estimated the bias in thickness measurements in simulated thin sheet images as obtained from second derivative zero crossings. To gain insight into the range of sheet thickness where our method is expected to yield improved results, sheet thickness was varied between 0.15 and 1.2 mm with an assumed PSF as present in the high-resolution modes of current computed tomography (CT) scanners [full width at half maximum (FWHM) 0.5-0.8 mm]. Our model-based method was evaluated in practice by measuring layer thickness from CT images of a phantom mimicking two parallel cartilage layers in an arthrography procedure. CT arthrography images of cadaver wrists were also evaluated, and thickness estimates were compared to those obtained from high-resolution anatomical sections that served as a reference. The thickness estimates from the simulated images reveal that the method based on second derivative zero crossings shows considerable bias for layers in the submillimeter range. This bias is negligible for sheet thickness larger than 1 mm, where the size of the sheet is more than twice the FWHM of the PSF but can be as large as 0.2 mm for a 0.5 mm sheet. The results of the phantom experiments show that the bias is effectively reduced by our method. The deviations from the true thickness, due to random fluctuations induced by quantum noise in the CT images, are of the order of 3% for a standard wrist imaging protocol. In the wrist the submillimeter thickness estimates from the CT arthrography images correspond within 10% to those estimated from the anatomical

  19. MRI evaluation of cranial bone marrow signal intensity and thickness in chronic anemia

    Energy Technology Data Exchange (ETDEWEB)

    Yildirim, Tulin E-mail: ytulin@hotmail.com; Agildere, A. Muhtesem; Oguzkurt, Levent; Barutcu, Ozlem; Kizilkilic, Osman; Kocak, Rikkat; Alp Niron, Emin

    2005-01-01

    Background and purpose: The aim is to assess the magnetic resonance imaging (MRI) findings for cranial bone marrow (CBM) signal intensity and thickness in patients with chronic anemia and compared these with findings in healthy subjects. We also investigated the relationships between CBM changes and age, type of anemia (hemolytic versus non-hemolytic), and severity of anemia. Methods: We quantitatively evaluated CBM signal intensity and thickness on images from 40 patients with chronic anemia (20 with congenital hemolytic anemia (HA) and 20 with acquired anemia) and compared these to findings in 28 healthy subjects. The intensity of CBM relative to scalp, white matter (WM), gray matter (GM), and muscle intensity was also investigated in patients and subjects in the control group. The sensitivity and specificity of CBM hypointense to GM and CBM hypointense to WM as markers of anemia were evaluated. Relationships between age and CBM thickness/intensity, and between anemia severity (hemoglobin (Hb) level) and CBM thickness/intensity were evaluated. Results: Cranial bone marrow signal intensity was lower in the chronic anemia patients than in the controls (P<0.001). In the control group, CBM intensity was higher than GM intensity, whereas the opposite was true in the patient group. The finding of CBM hypointense to GM was 85% sensitive and 67% specific as a marker of anemia. The corresponding statistics for CBM hypointense to WM were 90 and 46%. The patients had thicker CBM than the controls (temporal, P<0.05; parietal, P<0.005). The subgroup with hemolytic anemia had thicker parietal CBM than the subgroup with non-hemolytic anemia (NHA) (P<0.05) and exhibited thicker temporal and parietal CBM than the controls (temporal, P<0.05; parietal, P<0.001). The CBM thicknesses in the non-hemolytic anemia subgroup were similar to control values (P>0.05 for both). There were no correlations between age and CBM intensity or thickness, or between anemia severity and CBM intensity

  20. Measurement of subcutaneous adipose tissue thickness by near-infrared

    International Nuclear Information System (INIS)

    Obesity is strongly associated with the risks of diabetes and cardiovascular disease, and there is a need to measure the subcutaneous adipose tissue (SAT) layer thickness and to understand the distribution of body fat. A device was designed to illuminate the body parts by near-infrared (NIR), measure the backscattered light, and predict the SAT layer thickness. The device was controlled by a single-chip microcontroller (SCM), and the thickness value was presented on a liquid crystal display (LCD). There were 30 subjects in this study, and the measurements were performed on 14 body parts for each subject. The paper investigated the impacts of pressure and skin colour on the measurement. Combining with principal component analysis (PCA) and support vector regression (SVR), the measurement accuracy of SAT layer thickness was 89.1 % with a mechanical caliper as reference. The measuring range was 5–11 mm. The study provides a non-invasive and low-cost technique to detect subcutaneous fat thickness, which is more accessible and affordable compared to other conventional techniques. The designed device can be used at home and in community.

  1. On the comparison between MRI and US imaging for human heel pad thickness measurements

    DEFF Research Database (Denmark)

    Matteoli, Sara; Corbin, Nadège Corbin; Wilhjelm, Jens E.; Torp-Pedersen, Søren T.

    2011-01-01

    thickness as they are both ionizing-free radiations. The aim of this paper is to measure the bone to skin distance of nine heel pad phantoms from MRI and US images, and to compare the results with a true value (TV) in order to find the errors. Paired sample t-test was used to compare the measurements......1530 (P-value=0.402). Results confirm the necessity to investigate on the real speed of sound for the heel pad tissues, in order to have realistic measurements when dealing with human heel pads. __________________________________________________________________________________________________________...

  2. Thickness measurement instrument with memory storage of multiple calibrations

    International Nuclear Information System (INIS)

    An improved backscatter instrument for the nondestructive measurement of coatings on a substrate is described. A memory having selectable memory areas, each area having stored intelligence available which is determinative of the shape of a functional plot of coating thickness versus backscatter counts per minute unique for each particular combination of emitting isotope, substrate material, coating material and physical characteristics of the measuring instrument. A memory selector switch connects a selected area of memory to a microprocessor operating under program control whereby the microprocessor reads the intelligence stored at the selected area and converts the backscattered count of the coating being measured into indicia of coating thickness

  3. Refractive index of nanoscale thickness films measured by Brewster refractometry

    CERN Document Server

    Tikhonov, E A; Malyukin, Yu V

    2015-01-01

    It is shown that reflective laser refractometery at Brewster angle can be usefull for precision measurements of refractive indexes (RI) in the transparency band of various films of nanoscale thickness. The RI measurements of nanoscale porous film on the basis of gadolinium orthosilicate and quartz have been carried out as first experience. It is shown that surface light scattering in such films that is connected with clustering of nanoscale pores can decrease the accuracy of the RI measurements at Brewster angle. Estimated physical dependence RI stipulated by the film thickness reduction (3D-2D transition) in the range of (20-160)nm has not been not detected.

  4. Automation of the Tube-Thickness Measurements Using Ultrasonics

    International Nuclear Information System (INIS)

    Two ultrasonic methods for automatically measuring the wall thickness of thin-walled metal tubing are described and compared for accuracy and measurement rate. These methods are: (a) A double-probe method using an ultrasonic plane transmitter crystal to irradiate a small area of tube wall and a separate receiving crystal adjusted to receive energy from this same area; the two probes are mounted close to each other. As the transmitter frequency is varied, the receiver output shows an absorption resonance when the ultrasonic wavelength corresponds to twice the tube thickness. The paper describes the electronic circuits used to automatically adjust the frequency to keep the receiver output at minimum. By measuring this frequency a record in digital form of the thickness of the tube may be obtained. (b) A single-probe method using a focused transmitter probe directing a burst of energy, typically 30 μs duration of 5 MHz frequency, at normal incidence to the tube wall; the same probe acts as a receiver and electronic circuits are used to select the first reflected pulses. The paper describes how the transmitter frequency is varied automatically over a selected range and how the frequency at which a minimum reflected pulse occurs is selected and measured. This minimum occurs at a wavelength of twice the tube wall thickness so that again a direct digital measurement of thickness is achieved. (author)

  5. Direct and tomographic dimensional analysis of the inter-radicular distance and thickness of the vestibular cortical bone in the parasymphyseal region of adult human mandibles.

    Science.gov (United States)

    de Souza Fernandes, Atson Carlos; de Quadros Uzeda-Gonzalez, Sandra; Mascarenhas, Murillo Leita; Machado, Laila Aguiar; de Moraes, Márcio

    2012-06-01

    We calculated the inter-radicular distances between the canine, and first and second premolars, of human mandibles and the thickness of the cortical bone at adjacent sites using computed tomographic (CT) imaging, and assessed the precision of the dimensional assessment made by CT compared with the same measurement made directly with calipers. We examined 100 adult cadaveric dentate human hemimandibles. At the level at which monocortical screws are inserted to place miniplates according to the current technique used to treat mandibular fractures, points A, B, and C referred to the canine, and first and second premolars, and were marked to calculate the level of the CT slice and as the reference for sectioning of the hemimandible. Our findings showed that there was no significant difference in the inter-radicular distance or in the thickness of cortical bone between the sides of the mandible. The vestibular cortical bone was less than 3.0mm thick in 91 of the samples. In 98 of the samples the inter-radicular distance between the canine and the first and second premolars was more than 2mm. There was no significant difference in micrometric precision between the dimensional assessment on CT and direct measurement using a caliper. In the region of the mental foramen the screws have cortical bone less than 3mm thick in which to be anchored. The inter-radicular distance suggests that there is a minimal risk of radicular injury when miniscrews are inserted between the alveolar structures. CT is a reliable tool for measuring the inter-radicular distance and the thickness of mandibular cortical bone. PMID:21636186

  6. Sensor for thickness measurement of a liquid metal film

    International Nuclear Information System (INIS)

    Description, calibration and measuring method of a sensor for the measure of thin liquid metal depths in a temperature range of 0-5000C and for shift frequencies from 0 to 100 Hz; these sensors are based on the principle of induction-coil impedance variation, as a function of the thickness of an electrical conductor matter placed in the coil magnetic field

  7. Measurement of compressed breast thickness by optical stereoscopic photogrammetry

    International Nuclear Information System (INIS)

    The determination of volumetric breast density (VBD) from mammograms requires accurate knowledge of the thickness of the compressed breast. In attempting to accurately determine VBD from images obtained on conventional mammography systems, the authors found that the thickness reported by a number of mammography systems in the field varied by as much as 15 mm when compressing the same breast or phantom. In order to evaluate the behavior of mammographic compression systems and to be able to predict the thickness at different locations in the breast on patients, they have developed a method for measuring the local thickness of the breast at all points of contact with the compression paddle using optical stereoscopic photogrammetry. On both flat (solid) and compressible phantoms, the measurements were accurate to better than 1 mm with a precision of 0.2 mm. In a pilot study, this method was used to measure thickness on 108 volunteers who were undergoing mammography examination. This measurement tool will allow us to characterize paddle surface deformations, deflections and calibration offsets for mammographic units.

  8. Noninvasive thickness measurements of metal films through microwave dielectric resonators

    Science.gov (United States)

    Jung, Ho Sang; Lee, Jae Hun; Han, Hyun Kyung; Lee, Sang Young

    2016-05-01

    Thicknesses of Pt films ranging from 60 to 950 nm are measured noninvasively using a TE 011-mode dielectric resonator with the resonant frequency of 8.5 - 9.8 GHz at temperatures of 77 K and 293 K. A cylindrical rutile rod is used as the dielectric, with a high- T C superconductive YBa2Cu3O7- δ film used as the bottom endplate of the resonator for measurements at 77 K. This method is based on two facts: i) Due to the electromagnetic interferences of incoming and reflected waves at the surface of the metal film surface, the effective surface resistance varies with the film thickness, and ii) the intrinsic surface resistance of normal metals is equal to the intrinsic surface reactance in the local limit. The measured thicknesses using the rutile resonator appear to be comparable with those obtained using a profilometer. [Figure not available: see fulltext.

  9. High-precision thickness measurements using beta backscatter

    International Nuclear Information System (INIS)

    A two-axis, automated fixture for use with a high-intensity Pm-147 source and a photomultiplier-scintillation beta-backscatter probe for making thickness measurements has been designed and built. A custom interface was built to connect the system to a minicomputer, and software was written to position the tables, control the probe, and make the measurements. Measurements can be made in less time with much greater precision than by the method previously used

  10. Ultrasound settings significantly alter arterial lumen and wall thickness measurements

    Directory of Open Access Journals (Sweden)

    Green Daniel J

    2008-01-01

    Full Text Available Abstract Background Flow-mediated dilation (FMD and carotid intima-medial thickness (CIMT, measured by ultrasound, are widely used to test the efficacy of cardioprotective interventions. Although assessment methods vary, automated edge-detecting image analysis software is routinely used to measure changes in FMD and CIMT. We aimed to quantify the effect that commonly adjusted ultrasound settings have on arterial lumen and wall thickness measurements made with CIMT measurement software. Methods We constructed phantom arteries from a tissue-mimicking agar compound and scanned them in a water bath with a 10 MHz multi-frequency linear-array probe attached to a high-resolution ultrasound machine. B-mode images of the phantoms were recorded with dynamic range (DR and gain set at five decibel (dB increments from 40 dB to 60 dB and -10 dB to +10 dB respectively. Lumen diameter and wall-thickness were measured off-line using CIMT measurement software. Results Lumen measurements: there was a strong linear relationship between DR and gain and measured lumen diameter. For a given gain level, a 5 dB increase in DR reduced the measured lumen diameter by 0.02 ± 0.004 mm (p CIMT measurements: For a fixed gain level, a 5 dB increase in DR increased measured wall thickness by 0.003 ± 0.002 mm (p Conclusion DR, gain and probe distance significantly alter lumen diameter and CIMT measurements made using image analysis software. When CIMT and FMD are used to test the efficacy of cardioprotective interventions, the DR, gain and probe position used to record baseline scans should be documented and replicated in post-treatment scans in individual trial subjects. If more than one sonographer or imaging centre is used to collect data, the study protocol should document specific DR and gain settings to be used in all subjects.

  11. Pavement thickness measurement using FM-CW radar

    Science.gov (United States)

    Liu, C. Richard; Li, Jing; Gan, Xinhua; Xing, Huichuan; Chen, Xuemin

    2001-11-01

    Many theoretical studies have been reported on applications of ground penetrating radar (GPR) system to detect the permittivity and thickness of subsurface layers. However, to develop a GPR system that can accurately measure the thickness and the permittivity simultaneously is not a straightforward task. The main difficulty of quantitative thickness measurement is that the reflected wave from the subsurface interface is very weak compared to the directly coupled waves. The reflected signal may be completely submerged into the strong direct waves. Secondly, the inversion computation from measured data is very noise sensitive. In this paper, we present the development of a frequency-modulated-continuous-wave (FMCW) radar for quantitative layer thickness measurement. A new mathematical model for the calculation of depth and permittivity from the measured electromagnetic data is presented. The new model is based on the time delay between the direct wave and the reflected wave recorded by a bistatic radar. The data inversion algorithm considers the influences from air-ground interface. It is found that neglecting the air layer effects as the case applied in seismic analysis, the inversion will not be correct. This is because the electromagnetic rays from the GPR take different propagation path from straight or curved ray in seismic-like analysis. Ray path searching must be included in the calculation algorithm. With the consideration of wave path, the experimental results agree well with the actual values either in field test of in laboratory test.

  12. Infrared film thickness measurement. Comparison with cold neutron imaging

    International Nuclear Information System (INIS)

    Near infiaRed FILM thickness PROfile (NIR-FILMPRO) is a newly developed optical technique for non-intrusive measurement of water film thickness. The technique is based on light absorption. For the case of water, vibrational modes of H-O-H bonds give rise to absorption transitions with overtone and combination bands located in the near infrared spectral range which show an adequate attenuation for film film measurements. A near infrared camera and light projection system assembled in a geometry with reflective lighting offer time resolved measurements of the film thickness distribution on a 2D domain. The CCD detector array with 30 μm pitch InGaAs photosensitive sites provides 0.6 mm spatial resolution when combined with a 50 mm focal length lens and placed at 1 m from the target. The data acquisition electronic allows for a tame rate of 370 fps at full resolution (256 x 320 pixels) and up to 11 kfps for the minimum window size (128 x 8 pixels). For the validation of the technique, the thickness of a failing turbulent water film on a vertical wall was measured with both NIR-FILMPRO and cold neutrons. Cold neutron imaging allow for a comparison of time average measurements with high spatial resolution. An excellent correspondence between the two methods was found. The root mean square of the deviations between the two techniques was found to be 2.3% of the measurement for thicknesses ranging from approximately 100 μm to 500 μm. The strengths of the present technique are the applicability to demineralized water, the ability to see through steam-rich environments, and contactless measurements on prototypal surfaces with the presence of mass and enthalpy fluxes such as condensation and evaporation. (author)

  13. Dynamic-speckle profilometer for online measurements of coating thickness

    Energy Technology Data Exchange (ETDEWEB)

    Kamshilin, A A [Laboratory of Optical Sensor Technology, Department of Physics, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Semenov, D V [Laboratory of Optical Sensor Technology, Department of Physics, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Nippolainen, E [Laboratory of Optical Sensor Technology, Department of Physics, University of Kuopio, PO Box 1627, FIN-70211 Kuopio (Finland); Miridonov, S [Optics Department, CICESE, Carr. Tijuana-Ensenada km 107, C.P. 22860, A.P. 360, Ensenada, B.C. (Mexico)

    2007-10-15

    Online control of thickness of as-deposited coatings is of great importance because it directly affects the quality of protective coatings. We present a novel approach that enables online, real-time and non-contact measurements thickness of thermally sprayed coatings. The proposed technique uses dynamic speckles generated by rapidly deflecting laser beam. Within 10 ms the system can scan 500 times a small area of the deposited layer thus resulting in measurement accuracy of 5 microns irrespectively of the layer roughness. In comparison with traditional optical triangulation technique of distance measurements, our system has following advantages: (i) much simpler optical scheme that includes conventional photodiode to measure the scattered light, (ii) much simpler electronics for real-time data processing, (iii) much higher speed of measurements.

  14. Digital radiography for automated wall thickness measurement at insulated pipes

    International Nuclear Information System (INIS)

    The digital radiography system AMICA-410 enables the measurement of pipe wall thickness as well as pipe cross section at insulated and non-insulated pipework, and on stream processing and analysis of data with the integrated software. The hardware and software of the system and its performance are explained in the context of the scanning tasks. (orig./CB)

  15. Computerised system for measurement of muscle thickness based on ultrasonography.

    Science.gov (United States)

    Wong, Alexander; Gallagher, Kaitlin M; Callaghan, Jack P

    2013-01-01

    In this paper, a computerised system for measuring muscle thicknesses of the transverse abdominus (TrA), internal oblique and external oblique muscles based on ultrasonography is presented. The system is designed to allow for quantitative analysis of changes in muscle recruitment and activity, which facilitates the study of such changes and its relationship with low back pain. The abdominal muscle area was localised and imaged under different standing conditions using B-mode ultrasonography. To account for issues such as misalignments due to probe and subject motion as well as speckle noise inherent to ultrasonography, automatic ensemble registration is performed on the acquired images using a sequential quadratic programming approach based on a novel log-Rayleigh likelihood function. Regions of interest are then automatically identified based on the medial border of the TrA for the purpose of quantitative muscle thickness measurements. Experimental results show that the proposed system achieves registration errors of under 0.4 mm when compared with ground-truth measurements, as well as allow for the measurement of muscle thickness changes in the millimetre range. The proposed system is currently in operational use as an analysis tool for studying the relationship between abdominal muscle thickness changes and postural changes. PMID:22372597

  16. Ultrasonic eggshell thickness measurement for selection of layers.

    Science.gov (United States)

    Kibala, Lucyna; Rozempolska-Rucinska, Iwona; Kasperek, Kornel; Zieba, Grzegorz; Lukaszewicz, Marek

    2015-10-01

    This study aimed to develop a methodology for using ultrasonic technology (USG) to record eggshell thickness for selection of layers. Genetic correlations between eggshell strength and its thickness have been reported to be around 0.8, making shell thickness a selection index candidate element. Applying ultrasonic devices to measure shell thickness leaves an egg intact for further handling. In this study, eggs from 2 purebred populations of Rhode Island White (RIW) and Rhode Island Red (RIR) hens were collected on a single day in the 33rd week of the farm laying calendar from 2,414 RIR and 4,525 RIW hens. Beginning from the large end of the egg, measurements were taken at 5 latitudes: 0º (USG0), 45º (USG45), 90º (USG90), 135º (USG135), and 180º (USG180). To estimate the repeatability of readings, measurements were repeated at each parallel on 3 meridians. Electronic micrometer measurement ( EMM: ) were taken with an electronic micrometer predominantly at the wider end of eggs from 2,397 RIR and 4,447 RIW hens. A multiple-trait statistical model fit the fixed effect of year-of-hatch × hatch-within-year, and random effects due to repeated measurements (except EMM) and an animal's additive genetic component. The shell was thinnest in the region where chicks break it upon hatching (USG0, USG45). Heritabilities of shell thickness in different regions of the shell ranged from 0.09 to 0.19 (EMM) in RIW and from 0.12 to 0.23 (EMM) in RIR and were highest for USG45 and USG0. Because the measurement repeatabilities were all above 0.90, our recommendation for balancing egg strength against hatching ease is to take a single measurement of USG45. Due to high positive genetic correlations between shell thickness in different regions of the shell its thickness in the pointed end region will be modified accordingly, in response to selection for USG45. PMID:26316340

  17. Apparatus for measuring profile thickness of strip material

    International Nuclear Information System (INIS)

    Apparatus for measuring the thickness profile of steel strip comprises a radiation source reciprocally movable in a stepwise fashion (by a belt) across the strip width on one side thereof and a single elongated detector on the other side of the strip aligned with the scanning source. This detector may be a fluorescent scintillator detector or an ionisation chamber. Means are provided for sensing the degree of excitation in the detector in synchronism with the scanning source whereby to provide an output representative of the thickness profile of the strip. (author)

  18. Experimental rig for measuring lubricant film thickness in rolling bearings

    OpenAIRE

    Zhang, Xingnan; Jablonka, Karolina Anna; Glovnea, Romeo

    2014-01-01

    Electrical capacitance has been applied in the past for measuring the lubricant film thickness in rolling element bearings. The main difficulty arises from the fact that the measured capacitance is a combination of the capacitances of many rolling elements, which come in contact with both the inner and outer rings. Besides, the capacitance of the Hertzian contact itself and the surrounding area must also be separated. It results in a complex system which, in order to be solved for the film ...

  19. Noncontact ultrasonic thickness measurements of thin aluminium sheet

    International Nuclear Information System (INIS)

    A method has been described for the noncontact ultrasonic thickness measurements of thin aluminium sheets, using a Q-switched ruby laser generation concentric with an annular electro-magnetic acoustic transducer (EMAT) detection to imitate pulse-echo system. The detected waveforms were analyzed with the cut-off frequences of the higher order lamb modes. The results show in a good egreement with micrometer measurements within 2% discrepancy. (authors). 22 refs, 6 figs

  20. Measurement of camera image sensor depletion thickness with cosmic rays

    CERN Document Server

    Vandenbroucke, J; Bravo, S; Jensen, K; Karn, P; Meehan, M; Peacock, J; Plewa, M; Ruggles, T; Santander, M; Schultz, D; Simons, A L; Tosi, D

    2015-01-01

    Camera image sensors can be used to detect ionizing radiation in addition to optical photons. In particular, cosmic-ray muons are detected as long, straight tracks passing through multiple pixels. The distribution of track lengths can be related to the thickness of the active (depleted) region of the camera image sensor through the known angular distribution of muons at sea level. We use a sample of cosmic-ray muon tracks recorded by the Distributed Electronic Cosmic-ray Observatory to measure the thickness of the depletion region of the camera image sensor in a commercial smart phone, the HTC Wildfire S. The track length distribution prefers a cosmic-ray muon angular distribution over an isotropic distribution. Allowing either distribution, we measure the depletion thickness to be between 13.9~$\\mu$m and 27.7~$\\mu$m. The same method can be applied to additional models of image sensor. Once measured, the thickness can be used to convert track length to incident polar angle on a per-event basis. Combined with ...

  1. Space-resolved Resistive Measurement of Liquid Metal Wall Thickness

    CERN Document Server

    Mirhoseini, S M H

    2016-01-01

    In a fusion reactor internally coated with liquid metal, it will be important to diagnose the thickness of the liquid at various locations in the vessel, as a function of time, and possibly respond to counteract undesired bulging or depletion. The electrical conductance between electrodes immersed in the liquid metal can be used as a simple proxy for the local thickness. Here a matrix of electrodes is shown to provide spatially resolved measurements of liquid metal thickness in the absence of plasma. First a theory is developed for mxn electrodes, and then it is experimentally demonstrated for 3x1 electrodes. The experiments were carried out with Galinstan, but are easily extended to Lithium or other liquid metals.

  2. Criterions of UT thickness measurement on thinned pipe management program

    International Nuclear Information System (INIS)

    Wall thinning of carbon steel pipe components due to flow-accelerated corrosion (FAC) is one of the most serious threats to the integrity of steam cycle piping systems in Nuclear Power Plants (NPP). If the thickness of a pipe component is reduced below the critical level, it cannot sustain stress and consequently results in leakage or rupture. Since the mid-1990s, secondary side piping systems in Korean NPPs have experienced wall thinning, leakages and ruptures caused by FAC. Korea Electric Power Research Institute (KEPRI) and Korea Hydro and Nuclear Power Co., LTD. (KHNP) have conducted a study to develop the methodology for systematic pipe management and as a result, established the Korean thinned pipe management program (TPMP) which is being implemented to all Korean NPPs. TPMP consists of several technical elements such as prediction of the FAC rate for each component based on model analysis, prioritization of pipe components for inspection, thickness measurement, calculation of wear and wear rate for each component. Additionally, decision making associated with replacement or continuous service for thinned pipe components and establishment of long-term strategic management plan based on diagnosis of plant condition regarding overall wall thinning also are essential part of the TPMP. To effectively monitor and manage the thinning pipe components, NDE person as well as FAC engineer should understand the criterions of ultrasonic thickness measurement and there background. This paper describes the technical items of TPMP and the basis of thickness measurement criterions. This paper also shows the initial thickness variations which influence wear and wear rate calculations to obtain the reasonable integrity assessment results. (orig.)

  3. Nano-thick calcium oxide armed titanium: boosts bone cells against methicillin-resistant Staphylococcus aureus

    Science.gov (United States)

    Cao, Huiliang; Qin, Hui; Zhao, Yaochao; Jin, Guodong; Lu, Tao; Meng, Fanhao; Zhang, Xianlong; Liu, Xuanyong

    2016-02-01

    Since the use of systemic antibiotics for preventing acute biomaterial-associated infections (BAIs) may build up bacterial resistance and result in huge medical costs and unpredictable mortality, new precaution strategies are required. Here, it demonstrated that titanium armed with a nano-thick calcium oxide layer was effective on averting methicillin-resistant Staphylococcus aureus (MRSA) infections in rabbits. The calcium oxide layer was constructed by, firstly, injecting of metallic calcium into titanium via a plasma immersion ion implantation process, and then transforming the outer most surface into oxide by exposing to the atmosphere. Although the calcium oxide armed titanium had a relative low reduction rate (~74%) in growth of MRSA in vitro, it could markedly promote the osteogenic differentiation of bone marrow stem cells (BMSCs), restore local bone integration against the challenge of MRSA, and decrease the incidence of MRSA infection with a rate of 100% (compared to the titanium control). This study demonstrated for the first time that calcium, as one of the major elements in a human body, could be engineered to avert MRSA infections, which is promising as a safe precaution of disinfection for implantable biomedical devices.

  4. In situ heat exchanger tube fouling thickness measurements using ultrasonics

    Science.gov (United States)

    Hirshman, J.; Munier, R. S. C.

    1980-09-01

    The feasibility of establishing a practical microacoustic technique to measure fouling film thickness in situ on typical ocean thermal energy conversion (OTEC) heat exchanger tasks was studied. Seven techniques were studied for this application, including velocity measurements, acoustic diffraction, acoustic interferometer, Doppler flow velocity, pulse echo, critical angle, and surface (shear) wave effects. Of these, the latter five were laboratory tested using conventional microacoustic system components in various configurations. Only the pulse echo technique yielded promising results. On fouled aluminum plates, thin film layers of 40 microns and greater were measured using focused 30 MHz ceramic transducer operated at 25 MHz; this represents a resolution of about 2/3 wavelength. Measurements made on the inside of fouled 1 inch aluminum pipes yielded film thickness of 75 to 125 microns. The thinnest layer resolved was approximately 1-1/4 wavelength. The resolution of slime layer thickness in the magnitudes of OTEC interest (5 to 30 microns) using pulse echo microacoustics will require transducer development.

  5. Measurements of angular distributions of degraded protons in thick absorbers

    International Nuclear Information System (INIS)

    This chapter examines the behavior of a proton beam with a kinetic energy corresponding to the lower energy limit of the Low-Energy Antiproton Ring (LEAR), which is degraded by thick absorbers suffering an energy loss comparable to its initial energy. Angular distributions of protons are measured with an initial energy around 3.5 MeV, degraded by thick aluminium, polyethylene, and lead absorbers. Using the Erlangen Tandem accelerator, the measurements indicate that in all cases the variation of the width of the straggling distribution (fwhm) and of their mean energy as a function of the scattering angle was found to be small in the angular region between 00 and 150. It is concluded that degraders with low proton number are superior to those with high proton number, due to their narrower angular distributions

  6. Fuel miniplate thickness measurement system for dispersion fuel swelling evaluation

    International Nuclear Information System (INIS)

    This paper presents the commissioning test results of a system designed for fuel swelling evaluation, and constructed at IPEN-CNEN/SP. The system will be used in the qualification process of U3O8-Al and U3Si2-Al dispersion fuels with 3.0 gU/cm3 and 4.8 gU/cm3, respectively. The determination of the fuel swelling will be performed by means of fuel miniplate thickness measurements along the irradiation time, during the shutdown period between the operational cycles of the IEA-R1 reactor. The system will be located at the reactor pool fuel storage area and it will be operated from the reactor pool border, allowing the measurement of the fuel miniplate thickness along its surface by electronic probes (LVDT). The results will be obtained by the instrumentation connected to the probes. (author)

  7. A Simple Method for Measuring Organotypic Tissue Slice Culture Thickness

    OpenAIRE

    Guy, Yifat; Rupert, Amy; Sandberg, Mats; Weber, Stephen G.

    2011-01-01

    This paper presents a simple method to measure tissue slice thicknesses using an ohmmeter. The circuit described here is composed of a metal probe, an ohmmeter, a counter electrode, culture medium or physiological buffer, and tissue slice. The probe and the electrode are on opposite interfaces of an organotypic hippocampal slice culture. The circuit closes when the metal probe makes contact with the surface of the tissue slice. The probe position is recorded and compared to its position when ...

  8. Thickness measurement using ion beam techniques / Ramasukudu Gabriel Pitsoane

    OpenAIRE

    Pitsoane, Ramasukudu Gabriel

    2003-01-01

    Surface layer coatings, which are thin films in the range of micrometer and nanometer are of utmost importance. These layers have many applications and control processes like corrosion, friction, wearing and adhesion. Therefore the search for layers with satisfactory surface properties for different applications is needed. Thickness measurements were evaluated in this study using PIXE in conjunction with RBS. Different samples were evaluated using both the solid-state chamber and the nucle...

  9. MEASUREMENT OF RNFL THICKNESS USING OCT IMAGES FOR GLAUCOMA DETECTION

    Directory of Open Access Journals (Sweden)

    Dhivyabharathi

    2013-08-01

    Full Text Available The thickness of retinal nerve fiber layer (RNFL is one of the pompous parameters for assessing the disease, Glaucoma. A substantial amount of vision can be lost before the patient becomes aware of any defect. Optical Coherence Tomography (OCT provides enhanced depth and clarity of viewing tissues with high resolution compared with other medical imaging devices. It examines the living tissue non-invasively. This paper presents an automatic method to find the thickness of RNFL using OCT images. The proposed algorithm first extracts all the layers present in the OCT image by texture segmentation using Gabor filter method and an algorithm is then developed to segment the RNFL. The thickness measurement of RNFL is automatically displayed based on pixel calculation. The calculated thickness values are compared with the original values obtained from hospital. The result shows that the proposed algorithm is efficient in segmenting the region of interest without manual intervention. The effectiveness of the proposed method is proved statistically by the performance analysis.

  10. Mammographic calcification cluster detection and threshold gold thickness measurements

    Science.gov (United States)

    Warren, L. M.; Mackenzie, A.; Cooke, J.; Given-Wilson, R.; Wallis, M. G.; Chakraborty, D. P.; Dance, D. R.; Young, K. C.

    2012-03-01

    European Guidelines for quality control in digital mammography specify acceptable and achievable standards of image quality (IQ) in terms of threshold gold thickness using the CDMAM test object. However, there is little evidence relating such measurements to cancer detection. This work investigated the relationship between calcification detection and threshold gold thickness. An observer study was performed using a set of 162 amorphous selenium direct digital (DR) detector images (81 no cancer and 81 with 1-3 inserted calcification clusters). From these images four additional IQs were simulated: different digital detectors (computed radiography (CR) and DR) and dose levels. Seven observers marked and rated the locations of suspicious regions. DBM analysis of variances was performed on the JAFROC figure of merit (FoM) yielding 95% confidence intervals for IQ pairs. Automated threshold gold thickness (Tg) analysis was performed for the 0.25mm gold disc diameter on CDMAM images at the same IQs (16 images per IQ). Tg was plotted against FoM and a power law fitted to the data. There was a significant reduction in FoM for calcification detection for CR images compared with DR; FoM decreased from 0.83 to 0.63 (pIQ. Since the majority of threshold gold thicknesses for the various IQs were above the acceptable standard despite large variations in calcification detection by radiologists, current EU guidelines may need revising.

  11. Plating thickness measurement using x-ray fluorescence

    International Nuclear Information System (INIS)

    Recently, there has been increased demand for the accurate thickness measurement of the plating on small electronic parts. This technology is required for both production and quality control. The coating thickness measurement using X-ray fluorescence is the standard method used because of its accuracy and versatility. Beta-ray backscattering method is also described. The operation of a beta-ray gauge is fairly simple, and the normal measuring time with it is much shorter than that of other methods. It is one of nondestructive methods, and excellent in view of its accuracy, ease of operation and speed. The engineers of Seiko Instruments and Electronics Ltd. have endeavored to eliminate the weak points of beta-ray backscattering while keeping the instrument as inexpensive as possible. The detection system of X-ray fluorescence (XRF) was complicated and expensive, but the recent development of low cost and compact electronic devices brought the cost of XRF instruments down, thus the widely spread use of XRF advances. The data shows the many advantages of XRF over beta-ray backscattering. The on-line XRF coating thickness gauges for reel to reel plating application are at the forefront of this technology. The use of solid state detectors for XRF gauges to expand the application and to increase energy resolution is a possibility. Any strong competition does not seem to develop against XRF. (Kako, I.)

  12. X-ray-fluorescence measurement of thin film thicknesses

    International Nuclear Information System (INIS)

    A method and apparatus were developed for X-ray fluorescence measurement of the thicknesses of thin metal films deposited on top of each other on a substrate. The method is highly accurate and rapid and is especially useful for making microelectronic devices. The system involves exposing the metal films to X-ray radiation, then measuring the intensity of the various fluorescent lines excited by the radiation. The lead-detecting collimator has a conical bore and a very small entrance aperture used to define the surface area of the top film from which excited fluorescence is to be detected. The collimator has an opening in the side to allow some of the incident X-rays from the source to enter the bore to excite fluorescence in the lead. This fluorescence is monitored by a detector as a measure of the intensity of the incident X-rays. The system is first calibrated in a systematic way to specify a set of parameters characteristic of the plated-metal configuration to be measured. The sample is irradiated and the number of counts in each of the selector characteristic lines of the platings and substrate is measured. The thickness of the plating layers are then calculated by an iterative method in accordance with specified relationships between the calibrated parameters and the measured counts. (DN)

  13. Measurements of the combined cortical thickness of humerus and metacarpus in Korean people

    International Nuclear Information System (INIS)

    Measurement of the cortical thickness of the tubular bone has recently been known as a one of the best method diagnosing osteoporosis. It is suggested that the combined cortical thickness of better than other more complicated indices. The authors have attempted to measure the combined cortical thickness of the lower shaft of humerus and mid-shaft of the metacarpal, and review of literatures were carried out. The results are as follows: 1. The mean value of combined cortical thickness (CCT) of metacarpus and humerus of various age groups has been measured and calculated on roentgenograms in 791 patients. In the male, CCT of 2nd metacarpus is 4.7 ± 0.15 mm, 3rd metacarpus is 4.3 ± 0.11 mm, 4th metacarpus is 4.1 ± 0.20 mm. on 30-39 age group, and CCT of humerus is 9.4 ± 0.28 mm. In the female, CCT of 2nd metacarpus is 4.6 ± 0.17 mm, 3rd metacarpus is 4.3 ± 0.12, 4th metacarpus is 4.2 ± 0.41 mm. on 40 49 age group, CCT of humerus is 8.6 ± 0.13 mm. on 30-39 age group 2. Measurement of combined cortical thickness in the humerus demonstrated a gradual decrease of the cortex after 40-49 age groups in both sexes, while in the case of metacarpus, measurement of CCT in the 2nd metacarpus only demonstrated a gradual decrease of cortex with age in female. 3. Reduction rate of CCT is 1.5 ± 0.31 mm./10 yrs between 50-59 age groups and 60-69 age group in the humerus, in male. Mean reduction rate of CCT is 0.6 ± 0.21 mm./10 yrs after 30-39 age group in the female

  14. Auto-calibration of ultrasonic lubricant-film thickness measurements

    International Nuclear Information System (INIS)

    The measurement of oil film thickness in a lubricated component is essential information for performance monitoring and design. It is well established that such measurements can be made ultrasonically if the lubricant film is modelled as a collection of small springs. The ultrasonic method requires that component faces are separated and a reference reflection recorded in order to obtain a reflection coefficient value from which film thickness is calculated. The novel and practically useful approach put forward in this paper and validated experimentally allows reflection coefficient measurement without the requirement for a reference. This involves simultaneously measuring the amplitude and phase of an ultrasonic pulse reflected from a layer. Provided that the acoustic properties of the substrate are known, the theoretical relationship between the two can be fitted to the data in order to yield reflection coefficient amplitude and phase for an infinitely thick layer. This is equivalent to measuring a reference signal directly, but importantly does not require the materials to be separated. The further valuable aspect of this approach, which is demonstrated experimentally, is its ability to be used as a self-calibrating routine, inherently compensating for temperature effects. This is due to the relationship between the amplitude and phase being unaffected by changes in temperature which cause unwanted changes to the incident pulse. Finally, error analysis is performed showing how the accuracy of the results can be optimized. A finding of particular significance is the strong dependence of the accuracy of the technique on the amplitude of reflection coefficient input data used. This places some limitations on the applicability of the technique

  15. Technical aspects and clinical interpretation of bone mineral measurements.

    OpenAIRE

    Wahner, H

    1989-01-01

    Four procedures--single photon absorptiometry, dual photon absorptiometry, dual energy radiography, and quantitative computed tomography--allow nontraumatic measurement of bone mineral, with high accuracy and precision, under conditions generally encountered in patient care situations. By using these procedures, almost any part of the skeleton is accessible to such measurements. Total bone is measured by the absorptiometry procedures, trabecular bone by quantitative computed tomography. Sever...

  16. Bone lead measured by X-ray fluorescence: epidemiologic methods.

    OpenAIRE

    Hu, H; Aro, A; Rotnitzky, A

    1995-01-01

    In vivo X-ray fluorescence (XRF) measurement of bone lead concentration (XRF) has emerged as an important technique for future epidemiological studies of long-term toxicity. Several issues germane to epidemiologic methodology need to be addressed, however. First, sources of variability in measurements of bone lead need to be quantified, including imprecision related to the physical measurement itself and the variability of lead deposition over the two main compartments of bones (cortical vs. ...

  17. Measurement of the thickness of the bronchial epithelium

    International Nuclear Information System (INIS)

    Cancer of the lung in uranium miners is thought to be related to the inhalation of gaseous radon daughters which become attached to molecules of water vapour or to dust particles. Since, the depth of tissue penetration by alpha particles is short, the thickness of the epithelium that lines the bronchial tree may be a critical factor in the development of cancers at specific sites in the lung. The objectives of the present study were: 1) to measure the thickness of human bronchial epithelium; 2) to determine the distribution and depth of the nuclei of basal cells in the bronchial epithelium; and 3) to compare these parameters in groups of smokers and non-smokers. Twenty-nine surgically removed specimens of the lung were examined (26 smokers, 3 non-smokers). The specimens were fixed and prepared for examination by light and electron microscopy. Blocks of tissue were oriented so that the maximum number of bronchi were cut in cross-section; measurements included bronchi of all sizes from bronchial generations (1≥ 9.01 mm) diameter to the smallest bronchioles, generations 7 - 16 (0.26 - 2.0 mm). Comparison of measurements in smokers and non-smokers show no significant differences, so that the 29 cases are considered to represent a homogeneous group. With progressive divisions of the bronchi, the epithelium decreases in thickness. Of more importance are the figures relating to the distance from the cell surface to the underlying nucleus. Here too, with the exception of goblet cells, the measurements are significantly smaller in generations 7 - 16 than in generation 1

  18. Low frequency (5 MHz) impedance measurements of thick YBCO films

    International Nuclear Information System (INIS)

    Two-point low frequency impedance measurements of microstrip transmission lines, fabricated from thick YBCO (+10 wt.% Ag) films on YSZ and sapphire substrates, have provided intrinsic properties for these granular thick films. The variation of the resistance with temperature for all the films studied, with and without an external DC magnetic field, followed that found by the conventional four-point DC technique. However, the temperature variation of the reactance for these granular thick films showed four important features: (1) for temperatures below Tc(R=0) the reactance was purely inductive even when superconductivity had been destroyed by the application of an external magnetic field, but the tail of the resistive transition was still present; (2) high quality, melt textured, thick films had a small double peak (or broad single peak) structure in the inductance for temperatures above Tc which corresponded to changes in the tail of the resistivity transition and these peaks are interpreted in terms of magnetic field penetration into the inter- and intra-granular regions; (3) poor quality films and those intentionally doped with Y2BaCuO5 had a constant inductive value extending from low temperatures to a temperature corresponding to the end of the resistive tail; (4) as the temperature is increased beyond the onset of superconductivity the inductive reactance decreased rapidly, for all films studied, to a negative value (i.e. a capacitive reactance) and then decreased approximately linearly for further increases in temperature. The value of the capacitive reactance appeared to depend on the amount of (211) YBCO present in the film. Analysis of the film conducting path in terms of parallel conductance and susceptance components gives rise to a temperature dependence very similar to the susceptibility curves obtained from bulk YBCO material and their observed structure may be interpreted in terms of a granular model. (orig.)

  19. Comparison of interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns using cone-beam computed tomography

    Science.gov (United States)

    Khumsarn, Nattida; Patanaporn, Virush; Jotikasthira, Dhirawat

    2016-01-01

    Purpose This study evaluated and compared interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns, using cone-beam computed tomography (CBCT). Materials and Methods Pretreatment CBCT images of 24 Thai orthodontic patients with Class I and Class II skeletal patterns were included in the study. Three measurements were chosen for investigation: the mesiodistal distance between the roots, the width of the buccolingual alveolar process, and buccal cortical bone thickness. All distances were recorded at five different levels from the cementoenamel junction (CEJ). Descriptive statistical analysis and t-tests were performed, with the significance level for all tests set at p<0.05. Results Patients with a Class II skeletal pattern showed significantly greater maxillary mesiodistal distances (between the first and second premolars) and widths of the buccolingual alveolar process (between the first and second molars) than Class I skeletal pattern patients at 10 mm above the CEJ. The maxillary buccal cortical bone thicknesses between the second premolar and first molar at 8 mm above the CEJ in Class II patients were likewise significantly greater than in Class I patients. Patients with a Class I skeletal pattern showed significantly wider mandibular buccolingual alveolar processes than did Class II patients (between the first and second molars) at 4, 6, and 8 mm below the CEJ. Conclusion In both the maxilla and mandible, the mesiodistal distances, the width of the buccolingual alveolar process, and buccal cortical bone thickness tended to increase from the CEJ to the apex in both Class I and Class II skeletal patterns. PMID:27358819

  20. Film thickness measurements in liquid–liquid slug flow regimes

    International Nuclear Information System (INIS)

    Highlights: • A direct measure of film thickness in liquid–liquid flows was taken. • A region of constant film thickness is presents in slugs where LD⁎⩾1.86. • Experimental data shows the dependency of film thickness on Capillary number. • Expressions are presented to predict the magnitude of the film. -- Abstract: At present there is significant interest in the development of small scale medical diagnostic equipment. These devices offer faster processing times and require smaller sample volumes than equivalent macro scale systems. Although significant attention has been focused upon their outputs, little attention has been devoted to the detailed fluid mechanics that govern the flow mechanisms within these devices. Conventionally, the samples in these small scale devices are segmented into distinct discrete droplets or slugs which are suspended in an organic carrier phase. Separating these slugs from the channel wall is a very thin film of the organic carrier phase. The magnitude of this film is the focus of the present study and the effects of sample slug length and carrier phase fluidic properties on the film are examined over a range of Capillary numbers. A non-intrusive optical technique was used to capture images of the flow from which the magnitude of the film was determined. The experimental results show that the film is not constant along the length of the slug; however above a threshold value for slug length, a region of constant film thickness exists. When compared with existing correlations in the literature, the experimental data showed reasonable agreement with the Bretherton model when the Capillary number was calculated based on the mean two phase flow velocity. However, significant differences were observed when the Capillary number was redefined to account for the mean velocity at the liquid interface, i.e., the mean slug velocity. Analysis of the experimental data revealed that it fell into two distinct flow regimes; a visco

  1. Measurement of biofilm thickness. An effective Legionella risk assessment tool

    Energy Technology Data Exchange (ETDEWEB)

    Foret, Christophe [BKG France, Arnage (France); Martemianov, Serguei [Poitiers Univ. (FR). Lab. of Thermal Study (LET); Moscow Univ. (Russian Federation). Frumkin Inst. of Physical Chemistry and Electrochemistry; Hater, Wolfgang [BK Giulini GmbH, Duesseldorf (Germany); Merlet, Nicole; Chaussec, Guenole; Tribollet, Bernard

    2010-02-15

    The best way to prevent the risk of bacterial growth in water systems is to monitor and control the microorganisms (biofilm) attached to pipe walls. Three years of laboratory research led two Centre National de Recherche Scientifique (French National Center for Scientific Research) teams (UMR 6008 and UPR 15) to develop a tool designed to determine the average biofilm thickness. The average biofilm thickness measurements carried out on pilot plants fed with natural water were sufficiently accurate and sensitive to monitor the formation and development of biofilm in a water system and to determine the efficiency of the applied treatments. The implementation of appropriate treatments (type and dose of the treatment product) leads to a significant reduction in or even complete removal of the porous layer on the material surface. A reduction of the attached biomass, measured by the sensor, is connected to a decrease in the density of the bacterial attached to the material (viable flora in the plate count agar environment). (orig.)

  2. Flexible ultrasonic array transducer for thickness measurement of curved pipes

    International Nuclear Information System (INIS)

    The feeder pipes in a Pressurized Heavy Water Reactor (PHWR) has a very complicated form with bent pipes. In this study, we have fabricated the Polyvinylidene fluoride (PVDF) array transducer to meet the dimension requirement passing smoothly along the pipe and have evaluated the signals in order to increase the accuracy of measurement. A contact array transducer was fabricated using commercially available PVDF film samples. Each pulse echo signals were acquired and analyzed using the pulser/receiver, The array transducer was demonstrated to show a serviceable performance as a contact transducer. Pulse echo reflections from a back-wall of feeder pipe were shown as a typical wideband signal. Ultrasonic signals were analyzed by considering the center frequency, band width and waveform. PVDF array transducer for thickness measurement can be applied to monitor the integrity of feeder pipes in PHWR.

  3. Central Corneal Thickness Measurement by Ultrasound versus Orbscan II

    Science.gov (United States)

    Faramarzi, Amir; Ziai, Hossein

    2008-01-01

    Purpose To compare Orbscan II and ultrasonic pachymetry for measurement of central corneal thickness (CCT) in eyes scheduled for keratorefractive surgery. Methods CCT was measured using Orbscan II (Bausch & Lomb, USA) and then by ultrasonic pachymetry (Tomey SP-3000, Tomey Ltd, Japan) in 100 eyes of 100 patients with no history of ocular surgery scheduled for excimer laser refractive surgery. Results Mean CCT was 544.7±35.5 (range 453–637) μm by ultrasonic pachymetry versus 546.9±41.6 (range 435–648) μm measured by Orbscan II applying an acoustic factor of 0.92 (P=0.14). The standard deviation of measurements was greater with Orbscan pachymetry but the difference was not statistically significant. Conclusion CCT measurements by Orbscan II (applying an acoustic factor) and by ultrasonic pachymetry are not significantly different; however, when CCT readings by Orbscan II are in the lower range, it is advisable to recheck the measurements using ultrasonic pachymetry. PMID:23479527

  4. Usefulness of bone density measurement in fallers.

    Science.gov (United States)

    Blain, Hubert; Rolland, Yves; Beauchet, Olivier; Annweiler, Cedric; Benhamou, Claude-Laurent; Benetos, Athanase; Berrut, Gilles; Audran, Maurice; Bendavid, Sauveur; Bousson, Valérie; Briot, Karine; Brazier, Michel; Breuil, Véronique; Chapuis, Laure; Chapurlat, Roland; Cohen-Solal, Martine; Cortet, Bernard; Dargent, Patricia; Fardellone, Patrice; Feron, Jean-Marc; Gauvain, Jean-Bernard; Guggenbuhl, Pascal; Hanon, Olivier; Laroche, Michel; Kolta, Sami; Lespessailles, Eric; Letombe, Brigitte; Mallet, Eric; Marcelli, Christian; Orcel, Philippe; Puisieux, François; Seret, Patrick; Souberbielle, Jean-Claude; Sutter, Bruno; Trémollières, Florence; Weryha, Georges; Roux, Christian; Thomas, Thierry

    2014-10-01

    The objective of this systematic literature review is to discuss the latest French recommendation issued in 2012 that a fall within the past year should lead to bone mineral density (BMD) measurement using dual-energy X-ray absorptiometry (DXA). This recommendation rests on four facts. First, osteoporosis and fall risk are the two leading risk factors for nonvertebral fractures in postmenopausal women. Second, BMD measurement using DXA supplies significant information on the fracture risk independently from the fall risk. Thus, when a fall occurs, the fracture risk increases as BMD decreases. Third, osteoporosis drugs have been proven effective in preventing fractures only in populations with osteoporosis defined based on BMD criteria. Finally, the prevalence of osteoporosis is high in patients who fall and increases in the presence of markers for frailty (e.g., recurrent falls, sarcopenia [low muscle mass and strength], limited mobility, and weight loss), which are risk factors for both osteoporosis and falls. Nevertheless, life expectancy should be taken into account when assessing the appropriateness of DXA in fallers, as osteoporosis treatments require at least 12months to decrease the fracture risk. Another relevant factor is the availability of DXA, which may be limited due to geographic factors, patient dependency, or severe cognitive impairments, for instance. Studies are needed to better determine how the fall risk and frailty should be incorporated into the fracture risk evaluation based on BMD and the FRAX® tool. PMID:24703626

  5. Measurement of lumbar spine bone mineral content using dual photon absorptiometry. Usefulness in metabolic bone diseases

    International Nuclear Information System (INIS)

    Measurement of bone density using an accurate, non-invasive method is a crucial step in the clinical investigation of metabolic bone diseases, especially osteoporosis. Among the recently available techniques, measurement of lumbar spine bone mineral content (BMC) using dual photon absorptiometry appears as the primary method because it is simple, inexpensive, and involves low levels of radiation exposure. In this study, we measured the BMC in 168 normal adults and 95 patients. Results confirmed the good reproducibility and sensitivity of this technique for quantifying bone loss in males and females with osteoporosis. Significant bone loss was found in most females with primary hyperparathyroidism. Dual photon absorptiometry can also be used for quantifying increases in bone mass in Paget disease of bone and diffuse osteosclerosis. Osteomalacia is responsible for a dramatic fall in BMC reflecting lack of mineralization of a significant portion of the bone matrix, a characteristic feature in this disease. Furthermore, in addition to being useful for diagnostic purposes and for evaluation of the vertebral fracture risk, lumbar spine absorptiometry can be used for monitoring the effectiveness of bone-specific treatments

  6. Measuring soil layer thickness in land rearrangement with GPR data

    International Nuclear Information System (INIS)

    Accurate measurement of soil layer thickness by GPR (ground penetrating radar) is of great importance for overlay design and quality control/quality assurance for land rearrangement projects. Soil layer detection is complex because of multiple reflections and high attenuation for electromagnetic (EM) waves propagating in the soil media. This paper proposes a novel data processing method based on the reflection and refraction of the EM waves to improve the measurement accuracy. A cross-correlation sequence is introduced to align the traces, and the effects of random noise are reduced by using a forwards and backwards filtering procedure without phase delay. Additionally, the homomorphic deconvolution, namely the power cepstrum, is employed to deconvolve GPR data and, thus, to enhance its interface reflection. The results of the verification test show that the measurement can achieve high accuracy, with an error less than 10%, and the measurement performance is greatly improved by using the new method. Finally, a contour map of the research area is generated automatically for quality detection and quality control guidance. (paper)

  7. Measurement of wall thickness with electrodynamic test heads

    International Nuclear Information System (INIS)

    Starting from the boundary conditions fixed by the physical properties of the electromagnetic/acoustic conversion and the operating limits which result from these for the sensors used, the use of electro-dynamic ultrasonic transducers for measuring wall thickness and double checks in plants for automatic production inspection and production control is shown. The sensor itself is the heart of a test system, but only the equipment and plant concepts surrounding the sensor make economic solution of the test problem possible. The quality of the signals which are supplied by a sensor, determines the quality of a test system. This can only be achieved by optimising all parts of a complex automatic test rig, such as the test head, mechanics, electronics and evaluation for the test problem concerned. (orig./HP)

  8. Bone blood flow measured by 85 Sr microspheres and bone seeker clearances in the rat

    International Nuclear Information System (INIS)

    This paper investigates further the relationship between the initial bone clearance of a bone-seeking radioisotope or labeled substance and the bone blood flow. The bone blood flow of rats was modified over the widest possible range of physiological values by heating and cooling their hindlimbs. Osseous blood flow was measured by the arteriolar trapping of labeled microspheres of 15 micrometer diameter injected into the left ventricle. The plasma clearances of 45Ca and 99m Tc by bone were measured 10 min after the intravenous injection of radiocalcium and of 99m technetium pyrophosphate. The extraction ratio for 45Ca over the 10-min interval (45Ca clearance/bone plasma flow) was 0.60 for low blood flows, 0.40 for blood flows at rest, and 0.25 for high values of flow. The data for 99m Tc were, respectively, 0.68, 0.34, and 0.22. Initial bone clearances of either substance should not be used to measure the increases in bone blood flow over the values at rest

  9. A Study on the Thickness Measurement of Thin Film by Ultrasonic Wave

    International Nuclear Information System (INIS)

    Recently, it is gradually raised necessity that thickness of thin film is measured accurately and managed in industrial circles and medical world. In this study, regarding to the thickness of film which is in opaque object and is beyond distance resolution capacity, thickness measurement was done by MEM-cepstrum analysis of received ultrasonic wave. In measurement results, film thickness which is beyond distance resolution capacity was measured accurately. And within thickness range that don't exist interference, thickness measurement by MEM-ceptrum analysis was impossible

  10. Automatic system for measuring the zirconium liner and Zircaloy-2 thickness of zirconium liner tubes

    International Nuclear Information System (INIS)

    This paper reports on an automatic system to measure the zirconium liner thickness and Zircaloy-2 thickness of Zircaloy tubes with a zirconium liner for nuclear reactors. This system uses an electromagnetic probe connected to a data processing unit for measuring the liner thickness, an ultrasonic inspection system for measuring the wall-thickness, and a computer for calculating the Zircaloy-2 thickness from the liner thickness and wall-thickness. Fully automatic measurements on zirconium liner thickness and Zircaloy-2 thickness are performed with high accuracy to an order of 2 μm. This newly developed system is very useful in assuring the liner layer and Zircaloy-2 thickness in the production of high-quality cladding tubes

  11. The measurement of lubricant-film thickness using ultrasound

    OpenAIRE

    Dwyer-Joyce, R.S.; Drinkwater, B. W.; Donohoe, C.J.

    2003-01-01

    Ultrasound is reflected from a liquid layer between two solid bodies. This reflection depends on the ultrasonic frequency, the acoustic properties of the liquid and solid, and the layer thickness. If the wavelength is much greater than the liquid-layer thickness, then the response is governed by the stiffness of the layer. If the wavelength and layer thickness are similar, then the interaction of ultrasound with the layer is controlled by its resonant behaviour. This stiffness governed respon...

  12. Quantitative Evaluation of Factors Influencing the Repeatability of SD-OCT Thickness Measurements in the Rat

    OpenAIRE

    Lozano, Diana C.; Twa, Michael D.

    2012-01-01

    Repeatable retinal thickness measurements from SD-OCT in the rat were acquired by combining manual and automated realignment procedures. Despite these methods, thickness measurements were influenced by image quality and segmentation routines.

  13. Comparison between Carotid Artery Wall Thickness Measured by Multidetector Row Computed Tomography Angiography and Intimae-Media Thickness Measured by Sonography

    OpenAIRE

    Živorad N. Savić; Ivan I. Soldatović; Milan D. Brajović; Aleksandra M. Pavlović; Dušan R. Mladenović; Vesna D. Škodrić-Trifunović

    2011-01-01

    The increased thickness of the carotid wall >1 mm is a significant predictor of coronary and cerebrovascular diseases. The purpose of our study was to assess the agreement between multidetector row computed tomography angiography (MDCTA) in measuring carotid artery wall thickness (CAWT) and color Doppler ultrasound (CD-US) in measuring intimae-media thickness (IMT). Eighty-nine patients (aged 35–81) were prospectively analyzed using a 64-detector MDCTA and a CD-US scanner. Continuous data wer...

  14. Thickness and air gap measurement of assembled IR objectives

    Science.gov (United States)

    Lueerss, B.; Langehanenberg, P.

    2015-10-01

    A growing number of applications like surveillance, thermography, or automotive demand for infrared imaging systems. Their imaging performance is significantly influenced by the alignment of the individual lenses. Besides the lateral orientation of lenses, the air spacing between the lenses is a crucial parameter. Because of restricted mechanical accessibility within an assembled objective, a non-contact technique is required for the testing of these parameters. So far, commercial measurement systems were not available for testing of IR objectives since most materials used for infrared imaging are non-transparent at wavelengths below 2 μm. We herewith present a time-domain low coherent interferometer capable of measuring any kind of infrared material (e.g., Ge, Si, etc.) as well as VIS materials. The set-up is based on a Michelson interferometer in which the light from a broadband superluminescent diode is split into a reference arm with a variable optical delay and a measurement arm where the sample is placed. On a detector, the reflected signals from both arms are superimposed and recorded as a function of the variable optical path. Whenever the group delay difference is zero, a coherence peak occurs and the relative distances of the lens surfaces are derived from the optical delay. In order to penetrate IR materials, the instrument operates at 2.2 μm. Together with an LWIR autocollimator, this technique allows for the determination of centering errors, lens thicknesses and air spacings of assembled IR objective lenses with a micron accuracy. It is therefore a tool for precision manufacturing and quality control.

  15. Measurement of the through-thickness strength of composites

    OpenAIRE

    Taniguchi, Shinro.

    1998-01-01

    This research deals with the mechanical characterisation of thick composite laminates in the through-thickness direction. Three independent glass fibre/epoxy laminate configurations, namely cross, quasi-isotropic, and woven, plies were investigated. Six specimen configurations, of which two were developed herein, were employed in order to determine the strength behaviour of these three laminate configurations when subjected to inte...

  16. Automatic measuring system of zirconium thickness for zirconium liner cladding tubes

    International Nuclear Information System (INIS)

    An automatic measuring system of pure zirconium liner thickness for Zirconium-Zircaloy cladding tubes has been successfully developed. The system consists of three parts. An ultrasonic thickness measuring method for mother tubes before cold rolling; an electromagnetic thickness measuring method for the manufactured tubes, and, an image processing method for the cross sectional view of the manufactured cut tube samples

  17. Analysis on the deviation of feeder pipe ultrasonic thickness-measuring data

    International Nuclear Information System (INIS)

    This paper is an analysis on the large deviation of feeder ultrasonic thickness-measuring data in Qinshan NPP III, through which the influence of the inner surface of thin wall carbon steel pipe on ultrasonic thickness measurement accuracy is verified and a principle for selection of a thickness measuring probe for thin wall carbon steel pipe with rough inner surface is introduced. (author)

  18. Rotary union for use with ultrasonic thickness measuring probe

    International Nuclear Information System (INIS)

    A rotary union for rotatably supporting an ultrasonic probe operable to nondestructively measure the thickness of steam generator tubes to determine the amount of corrosion experienced by the tubes includes a stationary body having a bore therethrough and an outlet drain, and a fitting rotatably mounted within the upper end of the body. The fitting has a bore aligned with the bore of the body. An electrical cable positioned within a water supply tube in an annular arrangement passes through the bore of the body and the bore of the fitting. This annular arrangement, in turn, is positioned within a connector element which extends outwardly from the fitting bore and is connected to the ultrasonic probe. An elastomeric lower bushing seals the annular arrangement to the lower end of the rotary union body and an elastomeric upper bushing seals the connector element to the fitting to permit the connector element and the ultrasonic probe connected thereto to rotate with the fitting relative to the body. The lower and upper bushings permit water to be passed through the annular arrangement and into the ultrasonic probe and thereafter discharged between the annular arrangement and the connector element to the outlet drain of the rotary union body. 5 figs

  19. Bone mineral content measurement in metabolic bone disease

    International Nuclear Information System (INIS)

    Objective determinations of BMC are seldom required for the diagnosis of the metabolic and hormonal disorders which may result in osteoporosis. They are, however, required to document the osteoporosis itself as this is usually subclinical until late in the natural history of the disease process. Measurement of BMC in these disease processes is an important research tool in determining the effect of the disorder on the skeleton at different stages of the natural history and in investigating the effects of therapy and other interventions. Measurements of BMC may be useful in clinical practice in deciding whether to intervene in certain circumstances (e.g. asymptomatic hyperparathyroidism) or to withhold certain therapies (e.g. glucocorticoids) or to alter therapy (e.g. change from glucocorticoids to nonsteroidal immunosuppressives in autoimmune diseases). It may also play a role in monitoring the responses to therapeutic interventions. (orig.)

  20. Thickness measurement of Ni thin film using dispersion characteristics of a surface acoustic wave

    International Nuclear Information System (INIS)

    In this study, we suggest a method to measure the thickness of thin films nondestructively using the dispersion characteristics of a surface acoustic wave propagating along the thin film surface. To measure the thickness of thin films, we deposited thin films with different thicknesses on a Si (100) wafer substrate by controlling the deposit time using the E-beam evaporation method. The thickness of the thin films was measured using a scanning electron microscope. Subsequently, the surface wave velocity of the thin films with different thicknesses was measured using the V(z) curve method of scanning acoustic microscopy. The correlation between the measured thickness and surface acoustic wave velocity was verified. The wave velocity of the film decreased as the film thickness increased. Therefore, thin film thickness can be determined by measuring the dispersion characteristics of the surface acoustic wave velocity.

  1. Development of thickness measurement and thickness trend monitoring technology using high-temperature thin-film UT sensor

    International Nuclear Information System (INIS)

    In order to solve the problems of the thickness measurement, we have developed a thin-film UT sensor having excellent high-temperature durability and conformability in thin film form. In this paper, it was confirmed that the accuracy of thickness measurement for both complex geometries and plates at high-temperature was equivalent to the accuracy of conventional thickness measurement methods. It was also confirmed that the durability at high temperature and for temperature change in the actual equipment was sufficient by continuous heating and cycle heating tests. In addition, it was confirmed that continuous use for long term was possible by lifetime assessment. It is expected that through making the test results publicly known and a field trial in the actual plant, we are aiming to take this technique in to the Japanese standard for periodic inspection in the next step. (author)

  2. Baseline Bone Mineral Density Measurements Key to Future Testing Intervals

    Science.gov (United States)

    ... historical) Baseline Bone Mineral Density Measurements Key to Future Testing Intervals How often a woman should have ... BMD tests of the hip using a standard technology called dual-energy x-ray absorptiometry, or DXA. ...

  3. Ultrasonic measurement of water layer thickness by horizontal flow pattern profile in a KAERI HAWL

    International Nuclear Information System (INIS)

    An ultrasonic measurement technique for determining water layer thickness is presented. The technique can obtain information of the water layer thickness in a tube in the form of a horizontal flow pattern profile through the used of a correct quantitative method. The main objective of the present work is to measure the water layer thickness of the flow using an ultrasonic measurement system. Ultrasonic measurement techniques of water layer thickness are produced to measure the variations in water layer thickness in the horizontal stratified flow and vertical annular flow regimes. (author)

  4. Ultrasound measurements of overlying soft tissue thickness at four skeletal sites suitable for in vivo x-ray fluorescence

    International Nuclear Information System (INIS)

    Due to signal attenuation in overlying soft tissue, development of x-ray fluorescence systems to measure low atomic number elements, such as strontium, in human bone required a search for a skeletal site with thin overlying tissue. This paper reports ultrasound measurements of overlying tissue on 10 subjects, at four anatomical sites. The average tissue thickness at the finger was (2.9±0.7) mm. The average tissue thicknesses were (3.6±0.7) mm, (4.8±2.0) mm, and (8.4±1.7) mm at forehead, tibia and heel, respectively. Additionally, both parametric and nonparametric approaches to the relationship between body mass index (BMI) and tissue thickness suggest that there is a significant linear correlation between the subject's BMI and overlying tissue at the finger and heel bone. These correlations might be used as a criterion to perform XRF measurements, however a larger data set is required to address these correlations more clearly

  5. Quality of life measurement in bone metastases: A literature review

    Directory of Open Access Journals (Sweden)

    Sukirtha Tharmalingam

    2008-12-01

    Full Text Available Sukirtha Tharmalingam, Edward Chow, Kristin Harris, Amanda Hird, Emily SinclairRapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, CanadaAbstract: Quality of life (QOL has become an important consideration in the care of patients with bone metastases as prevalence, incidence and patient survival are on the rise. As a result, more interventional studies now measure patient’s QOL as a meaningful endpoint. However, well-developed bone metastases specific quality of life instruments are lacking. A literature review was conducted to better understand the nature of QOL instruments used in bone metastases trials. A total of 47 articles evaluating QOL in patients with bone metastases were identified. Twenty-five different instruments were used to evaluate QOL with study-designed questionnaires and the EORTC QLQ-C30 being most commonly employed. Many studies used more than one scale or instrument to measure QOL. This makes it difficult to compare QOL in bone metastases patients across studies and come to any formal conclusions. Therefore, this review demonstrates the need to develop a bone module that can be used across countries in future clinical trials.Keywords: bone metastases, quality of life, QOL instrument, review

  6. Bone mineral measurements and the pathogenesis of osteoporosis

    International Nuclear Information System (INIS)

    Low bone mass (osteopenia) is a major factor in the development of osteoporotic fractures in women after the menopause. The pathogenesis of postmenopausal osteoporosis has been pursued by dual lines of investigation: (1) development of a model to describe involutional bone loss, (2) identification of those factors which result in some healthy women having a greater risk for osteoporosis than others. Bone mineral measurements have been made using in vivo neutron activation analysis and whole body counting for the measurement of total body calcium (TBCa), single photon absorptiometry for the measurement of bone mineral content of the distal radius and dual photon absorptiometry for measurement of the bone density of the spine. TBCa is higher in men than women and is lost at a slow linear rate in men. Blacks have a skeletal mass about 8-9% higher than Caucasians. Women have a similar loss of TBCa to men prior to menopause, but then have an accelerated rate of loss after menopause. The change in bone density of the radius and spine with increasing age is also best described by a 2 phase regression in women, with appreciable loss after age 50

  7. How do changes to plate thickness, length, and face-connectivity affect femoral cancellous bone's density and surface area? An investigation using regular cellular models.

    Science.gov (United States)

    Anderson, I A; Carman, J B

    2000-03-01

    Models of regular cellular-solids representing femoral head 'medial group' bone were used to (1) compare thickness data for plate-like and beam-like structures at realistic surface areas and densities; (2) test the validity of a standard formula for trabecular thickness (Tb.Th); and (3) study how systematic changes in cancellous bone thicknesses, spacing, and face-connectivity affect relative density and surface area. Models of different face-connectivities, produced by plate removal from the unit cell, were fitted to bone density and surface area data. The medial group bone was anisotropic: the supero-inferior (SI) direction was the principal direction for bone plate alignment and the plane normal to this had the largest number of bone/void intersections per unit line length (P(I)). A comparison of boundary perimeter per unit area data, in planes normal to SI, with surface area data placed the medial group bone between prismatic structures in which walls are parallel to one principal direction and isotropic structures. Selective removal of plates from a closed-cell model produced a similar result. For the same relative density and surface-area, plate-like models had significantly thinner cross-sections than beam-like models. The formula for Tb.Th produced overestimates of model plate thickness by up to 20% at realistic femoral cancellous densities. Trends in data on surface area to volume ratio and density observed on sampled medial group bone could be simulated by plate thickness changes on models of intermediate face-connectivity (approximately 1.5) or by plate removal from models with relatively thick and short (low aspect-ratio) plates. The latter mechanism is unrealistic for it resulted in beam-like structures at low 'medial group' densities, an architecture unlike the predominantly plate-like bone in the sample. PMID:10673116

  8. Polymer deformation gage measures thickness change in tensile tests

    Science.gov (United States)

    Broyles, H. F.; Broyles, H. H.

    1966-01-01

    Lightweight deformation gage attached to a polymer specimen determines the thickness changes undergone by the specimen during the testing of its tensile and elongation properties. Mechanical noise from outside sources is dampened when the assembly is hung on a light rubber band.

  9. 3D thickness profile measurement of thin films coated on the microscopic area

    International Nuclear Information System (INIS)

    Film thickness profile measurements are crucial in manufacturing processes of thin film–based devices that require precisely controlled thickness and surface morphology. However, film thickness measurement techniques, such as scanning electron microscopy, transmission electron microscopy, and ellipsometry, are limited to 1D or 2D analyses. We propose a new method to measure 3D thickness profiles. The resulting profiles contain not only the thin film surface morphologies but also 3D thickness data. The proposed method includes direct surface measurements and an alignment process utilizing fiducial marks. The top and bottom surface profiles of the film are directly measured using atomic force microscopy before and after a selective etching process. The proposed method based on simple principles including surface measurement and alignment processes is capable of evaluating films that are too thick to be measured using optical methods. (paper)

  10. Central Corneal Thickness Measurement by Ultrasound versus Orbscan II

    Directory of Open Access Journals (Sweden)

    Amir Faramarzi

    2008-12-01

    Full Text Available

    PURPOSE: To compare Orbscan II and ultrasonic pachymetry for measurement of central corneal thickness (CCT in eyes scheduled for keratorefractive surgery. METHODS: CCT was measured using Orbscan II (Bausch & Lomb, USA and then by ultrasonic pachymetry (Tomey SP-3000, Tomey Ltd, Japan in 100 eyes of 100 patients with no history of ocular surgery scheduled for excimer laser refractive surgery. RESULTS: Mean CCT was 544.7±35.5 (range 453-637 µm by ultrasonic pachymetry versus 546.9±41.6 (range 435-648 µm measured by Orbscan II applying an acoustic factor of 0.92 (P=0.14. The standard deviation of measurements was greater with Orbscan pachymetry but the difference was not statistically significant. CONCLUSION: CCT measurements by Orbscan II (applying an acoustic factor and by ultrasonic pachymetry are not significantly different; however, when CCT readings by Orbscan II are in the lower range, it is advisable to recheck the measurements using ultrasonic pachymetry.

  1. Enhanced cortical thickness measurements for rodent brains via Lagrangian-based RK4 streamline computation

    Science.gov (United States)

    Lee, Joohwi; Kim, Sun Hyung; Oguz, Ipek; Styner, Martin

    2016-03-01

    The cortical thickness of the mammalian brain is an important morphological characteristic that can be used to investigate and observe the brain's developmental changes that might be caused by biologically toxic substances such as ethanol or cocaine. Although various cortical thickness analysis methods have been proposed that are applicable for human brain and have developed into well-validated open-source software packages, cortical thickness analysis methods for rodent brains have not yet become as robust and accurate as those designed for human brains. Based on a previously proposed cortical thickness measurement pipeline for rodent brain analysis,1 we present an enhanced cortical thickness pipeline in terms of accuracy and anatomical consistency. First, we propose a Lagrangian-based computational approach in the thickness measurement step in order to minimize local truncation error using the fourth-order Runge-Kutta method. Second, by constructing a line object for each streamline of the thickness measurement, we can visualize the way the thickness is measured and achieve sub-voxel accuracy by performing geometric post-processing. Last, with emphasis on the importance of an anatomically consistent partial differential equation (PDE) boundary map, we propose an automatic PDE boundary map generation algorithm that is specific to rodent brain anatomy, which does not require manual labeling. The results show that the proposed cortical thickness pipeline can produce statistically significant regions that are not observed in the previous cortical thickness analysis pipeline.

  2. Ultrasonic measurement of lubricant film thickness in sliding bearings with thin liners

    International Nuclear Information System (INIS)

    When conducting ultrasonic measurements of the lubricant film thickness in sliding bearings with thin liners, the ultrasonic pulse reflected from the bearing liner–lubricant film interface will superimpose on the pulse reflected from the bearing substrate–liner interface. The thickness information of the lubricant film is contained in the reflected pulse from the liner–lubricant film interface. In this case, the film thickness could not be obtained directly from the superimposed reflected signals. The thin liner indicates that the thickness of the bearing liner is less than half the ultrasonic pulse width. Based on the spectrum analysis method of superimposed signals, a new method is proposed to measure the lubricant film thickness in sliding bearings with thin liners. The frequency-domain amplitude ratio between the echo component containing thickness information and the steady echo component from the bearing substrate–liner interface is extracted from the superimposed signal. The reflection coefficient of the liner–lubricant film interface is obtained by this amplitude ratio to determine the film thickness. The lubricant films of different thicknesses in a thin-liner thrust pad were measured in a high-precision experimental apparatus. The measurement results were compared with the known film thickness set by the experimental apparatus. In the thinner film region, the measurement results agreed well with the set film thickness. In the thicker film region, the mean values of the multiple measurement results represented the film thickness. The experimental results show that the method can be used to measure the lubricant film thickness in sliding bearings with thin liners. (paper)

  3. Bone mineral measurement, experiment M078. [space flight effects on human bone composition

    Science.gov (United States)

    Rambaut, P. C.; Vogel, J. M.; Ullmann, J.; Brown, S.; Kolb, F., III

    1973-01-01

    Measurement tests revealed few deviations from baseline bone mineral measurements after 56 days in a Skylab-type environment. No mineral change was observed in the right radius. One individual, however, showed a possible mineral loss in the left os calcis and another gained mineral in the right ulna. The cause of the gain is unclear but may be attributable to the heavy exercise routines engaged in by the crewmember in question. Equipment problems were identified during the experiment and rectified.

  4. Application of the astigmatic method to the thickness measurement of glass substrates

    Science.gov (United States)

    Zhang, Jingchao; Ding, Rui; Yan, Xi; Li, Li; Han, Zhiping

    2011-06-01

    We developed a high accuracy thickness measurement system for glass substrates based on the optical design of the astigmatic method. Reflective optical measurement systems are the most widely used glass thickness measurement methods in current industrial production practice. The incline of glass in reflective optical measurement system is the main factor of inaccuracy of thickness data. Compared with reflective optical measurement system, we found our design could effectively eliminate errors of glass thickness caused by slightly shifts of glass tilt. The astigmatic optical system includes a laser diode, a cylindrical lens, and a quadrant detector. This method measures the astigmatic focusing error signal induced form the measured glass placed in the astigmatic optical system. The astigmatic focusing error signal is converted into the thickness of the glass substrate. The proposed glass thickness measurement system is verified by using a coordinate measuring machine (CMM). On the validation of our system using tri-ordinate measuring machine, the accuracy of the proposed system is 0.2 μm, with a standard deviation of 0.7μm within the thickness measuring range of 1.2mm.

  5. 3D CT Imaging Method for Measuring Temporal Bone Aeration

    International Nuclear Information System (INIS)

    Objective: 3D volume reconstruction of CT images can be used to measure temporal bene aeration. This study evaluates the technique with respect to reproducibility and acquisition parameters. Material and methods: Helical CT images acquired from patients with radiographically normal temporal bones using standard clinical protocols were retrospectively analyzed. 3D image reconstruction was performed to measure the volume of air within the temporal bone. The appropriate threshold values for air were determined from reconstruction of a phantom with a known air volume imaged using the same clinical protocols. The appropriate air threshold values were applied to the clinical material. Results: Air volume was measured according to an acquisition algorithm. The average volume in the temporal bone CT group was 5.56 ml, compared to 5.19 ml in the head CT group (p = 0.59). The correlation coefficient between examiners was > 0.92. There was a wide range of aeration volumes among individual ears (0.76-18.84 ml); however, paired temporal bones differed by an average of just 1.11 ml. Conclusions: The method of volume measurement from 3D reconstruction reported here is widely available, easy to perform and produces consistent results among examiners. Application of the technique to archival CT data is possible using corrections for air segmentation thresholds according to acquisition parameters

  6. Zirconia thickness measurements for irradiated fuel rods: an approach to better understanding measurement error

    International Nuclear Information System (INIS)

    Non-destructive examinations (NDE) on irradiated PWR fuel rods have been performed since 1992 at the CEA/Cadarache Research Centre. Among the different controls performed, measurement of the zirconia thickness provides useful information on the axial and angular distribution of corrosion down the rod. This is necessary to compare the sensitivity of different cladding types with the creation of zirconia, as well as to detect and measure effects such as local corrosion. A dedicated apparatus based on eddy currents was used to measure the zirconia thicknesses. To verify the accuracy of our measurements, we compared the measurement results with the metallographic measurements of 39 samples. It was observed that the non-destructive measurements always overestimated the thickness of zirconia. The mean value of this systematic error was about 4 μm. We therefore tried to identify the origin of this error. We first observed that the sensor position was crucial. It must be in the exact same position for both the standard (tube section) and the rods. A poorly-positioned sensor on the rod produces overestimated measurement values. Other sources of uncertainty may also explain the difference with the exact values: first, the cladding of the standard was not irradiated. We know that some physical characteristics of cladding change during irradiation, in particular electrical conductivity. We do not know how this affects our measurement. Secondly, the rods still contained some decay heat. Thus, the temperature of the rod cladding could differ from the temperature of the standard. The electrical conductivity of the cladding and thus the eddy current response could be different. The sensor itself could also be affected by the temperature. We have performed several experiments on both heated cladding (not irradiated) and irradiated PWR fuel rods inside the hot cell. Based on the results of these tests and in agreement with our feedback, it was found that the device used in the

  7. Zirconia thickness measurements for irradiated fuel rods: an approach to better understanding measurement error

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, B.; Martella, T.; Pras, M.; Masson-Fauchier, M. [CEA/DEN/CAD/DEC/SA3C/Legend (France); Fayette, L. [CEA/DEN/CAD/DEC/SA3C/LEMCI (France)

    2011-07-01

    Non-destructive examinations (NDE) on irradiated PWR fuel rods have been performed since 1992 at the CEA/Cadarache Research Centre. Among the different controls performed, measurement of the zirconia thickness provides useful information on the axial and angular distribution of corrosion down the rod. This is necessary to compare the sensitivity of different cladding types with the creation of zirconia, as well as to detect and measure effects such as local corrosion. A dedicated apparatus based on eddy currents was used to measure the zirconia thicknesses. To verify the accuracy of our measurements, we compared the measurement results with the metallographic measurements of 39 samples. It was observed that the non-destructive measurements always overestimated the thickness of zirconia. The mean value of this systematic error was about 4 {mu}m. We therefore tried to identify the origin of this error. We first observed that the sensor position was crucial. It must be in the exact same position for both the standard (tube section) and the rods. A poorly-positioned sensor on the rod produces overestimated measurement values. Other sources of uncertainty may also explain the difference with the exact values: first, the cladding of the standard was not irradiated. We know that some physical characteristics of cladding change during irradiation, in particular electrical conductivity. We do not know how this affects our measurement. Secondly, the rods still contained some decay heat. Thus, the temperature of the rod cladding could differ from the temperature of the standard. The electrical conductivity of the cladding and thus the eddy current response could be different. The sensor itself could also be affected by the temperature. We have performed several experiments on both heated cladding (not irradiated) and irradiated PWR fuel rods inside the hot cell. Based on the results of these tests and in agreement with our feedback, it was found that the device used in the

  8. Assessment of Nuclear Fuels using Radiographic Thickness Measurement Method

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad Abir; Fahima Islam; Hyoung Koo Lee; Daniel Wachs

    2014-11-01

    The Convert branch of the National Nuclear Security Administration (NNSA) Global Threat Reduction Initiative (GTRI) focuses on the development of high uranium density fuels for research and test reactors for nonproliferation. This fuel is aimed to convert low density high enriched uranium (HEU) based fuel to high density low enriched uranium (LEU) based fuel for high performance research reactors (HPRR). There are five U.S. reactors that fall under the HPRR category, including: the Massachusetts Institute of Technology Reactor (MITR), the National Bureau of Standards Reactor (NBSR), the Missouri University Research Reactor (UMRR), the Advanced Test Reactor (ATR), and the High Flux Isotope Reactor (HFIR). U-Mo alloy fuel phase in the form of either monolithic or dispersion foil type fuels, such as ATR Full-size In center flux trap Position (AFIP) and Reduced Enrichment for Research and Test Reactor (RERTR), are being designed for this purpose. The fabrication process1 of RERTR is susceptible to introducing a variety of fuel defects. A dependable quality control method is required during fabrication of RERTR miniplates to maintain the allowable design tolerances, therefore evaluating and analytically verifying the fabricated miniplates for maintaining quality standards as well as safety. The purpose of this work is to analyze the thickness of the fabricated RERTR-12 miniplates using non-destructive technique to meet the fuel plate specification for RERTR fuel to be used in the ATR.

  9. Thickness measurements of zircaloy fuel cladding tube having the surface oxide layer by ultrasonic signal processing

    International Nuclear Information System (INIS)

    The purpose of this study is to develop an ultrasonic method for measuring the actual thickness of zircaloy-2 alloy tube with the thin surface oxide layer using a high frequency broadband focused transducer which can produce a short-duration echo. The main algorithm of signal processing technique for thickness measurements deals with the problem for separating of echoes very close to each other and calculating of the propagation time between these two echoes by using the cross-correlation method. A computer-implemented ultrasonic method based on this algorithm was established in this study. The results of thickness measurement in metal-wall of zircaloy tubes which were artificially plasma-sprayed with ZrO2 were presented. The comparison of ultrasonically measured thickness with the metallographically determined ones showed that the proposed method has a reasonable accuracy for the measurements of actual thin metal-wall thickness in the oxided zircaloy tubes. (author)

  10. Ultrasonic Measurement of Water Layer Thickness by Flow Pattern Profile in a Horizontal Air Water Loop

    International Nuclear Information System (INIS)

    Ultrasonic methods have the advantage, compared to other water layer thickness measurement techniques, of applicability to large volume objects, since most radiation techniques are limited by the thickness of the pipe and plate walls. The ultrasonic experiment was performed to do an analysis for cooling performance in a complete test channel by the investigation of the two phase flow that develops in an inclined gap with heating from the top. This ultrasonic technique for measuring water layer thickness measurement employ the higher relative acoustic impedance of air with respect to that of liquids. By this method it is possible to determine both liquid water distance, void fraction in a gas-liquid two-phase flow. Instantaneous measurement of the water layer thickness is useful in understanding heat and mass transfer characteristics in a two-phase separated flow. An ultrasonic measurement technique for determining water layer thickness in the wavy and slug flow regime of horizontal tube flow has been produced

  11. Role of ultrasound and color doppler in diagnosis of periapical lesions of endodontic origin at varying bone thickness

    Science.gov (United States)

    Tikku, Aseem P; Bharti, Ramesh; Sharma, Neha; Chandra, Anil; Kumar, Ashutosh; Kumar, Sunil

    2016-01-01

    Aims: To access the role of ultrasound and color doppler in diagnosing periapical lesions of maxilla and mandible. Settings and Design: This study was conducted in the Department of Conservative Dentistry and Endodontics (Faculty of Dental Sciences), Department of Radiotherapy, and Department of Pathology. Materials and Methods: The study group comprised 30 patients with periapical lesions of endodontic origin in maxilla and mandible requiring endodontic surgery. After thorough clinical and radiographic examination patients were subjected to ultrasound and color doppler examination, where the lesions were assessed for their contents as to cystic or solid. Following which periapical surgery was done and the pathological tissue obtained was subjected to histopathological examination. The results of the ultrasound examination were correlated with histopathological features. The diagnostic validity of ultrasound was assessed by calculating the sensitivity, specificity, positive predictive value, and negative predictive value. Statistical Analysis Used: The statistical analysis was done using statistical package for social sciences (SPSS) version 15.0 statistical analysis software. The values were represented in number (%). Results: Within the limitations of the current study it can be stated that although ultrasound may not establish the definitive diagnosis, it can facilitate the differential diagnosis between cystic and solid granulomatous lesions. However, this technique may have a limited role in detecting periapical lesions present in the region with thick overlying cortical bone. Conclusion: Ultrasound can routinely be recommended as a complimentary method for the diagnosis of periapical lesions of endodontic origin. However, this technique may have a limited role in detecting periapical lesions present in the region with thick overlying cortical bone. PMID:27099421

  12. PSF and MTF measurement methods for thick CCD sensor characterization

    Science.gov (United States)

    Takacs, P. Z.; Kotov, I.; Frank, J.; O'Connor, P.; Radeka, V.; Lawrence, D. M.

    2010-07-01

    Knowledge of the point spread function (PSF) of the sensors to be used in the Large Synoptic Survey Telescope (LSST) camera is essential for optimal extraction of subtle galaxy shape distortions caused by gravitational weak lensing. We have developed a number of techniques for measuring the PSF of candidate CCD sensors to be used in the LSST camera, each with its own strengths and weaknesses. The two main optical PSF measurement techniques that we use are the direct Virtual Knife Edge (VKE) scan as developed by Karcher, et al.1 and the indirect interference fringe method after Andersen and Sorensen2 that measures the modulation transfer function (MTF) directly. The PSF is derived from the MTF by Fourier transform. Other non-optical PSF measurement techniques that we employ include 55Fe x-ray cluster image size measurements and statistical distribution analysis, and cosmic ray muon track size measurements, but are not addressed here. The VKE technique utilizes a diffraction-limited spot produced by a Point-Projection Microscope (PPM) that is scanned across the sensor with sub-pixel resolution. This technique closely simulates the actual operating condition of the sensor in the telescope with the source spot size having an f/# close to the actual telescope design value. The interference fringe method uses a simple equal-optical-path Michelson-type interferometer with a single-mode fiber source that produces interference fringes with 100% contrast over a wide spatial frequency range sufficient to measure the MTF of the sensor directly. The merits of each measurement technique and results from the various measurement techniques on prototype LSST sensors are presented and compared.

  13. PSF and MTF Measurement Methods for Thick CCD Sensor Characterization

    International Nuclear Information System (INIS)

    Knowledge of the point spread function (PSF) of the sensors to be used in the Large Synoptic Survey Telescope (LSST) camera is essential for optimal extraction of subtle galaxy shape distortions caused by gravitational weak lensing. We have developed a number of techniques for measuring the PSF of candidate CCD sensors to be used in the LSST camera, each with its own strengths and weaknesses. The two main optical PSF measurement techniques that we use are the direct Virtual Knife Edge (VKE) scan as developed by Karcher, et al. and the indirect interference fringe method after Andersen and Sorensen that measures the modulation transfer function (MTF) directly. The PSF is derived from the MTF by Fourier transform. Other non-optical PSF measurement techniques that we employ include 55Fe x-ray cluster image size measurements and statistical distribution analysis, and cosmic ray muon track size measurements, but are not addressed here. The VKE technique utilizes a diffraction-limited spot produced by a Point-Projection Microscope (PPM) that is scanned across the sensor with sub-pixel resolution. This technique closely simulates the actual operating condition of the sensor in the telescope with the source spot size having an f/number close to the actual telescope design value. The interference fringe method uses a simple equal-optical-path Michelson-type interferometer with a single-mode fiber source that produces interference fringes with 100% contrast over a wide spatial frequency range sufficient to measure the MTF of the sensor directly. The merits of each measurement technique and results from the various measurement techniques on prototype LSST sensors are presented and compared.

  14. Measurement of stratospheric ozone layer thickness using 0.65 Nm resolution micro spectrometer

    OpenAIRE

    Klaudija Bašić-Palković; Zoran Mijatović

    2005-01-01

    Results of ozone layer thickness measurements are presented. Instead of expensive Dobson or Brewer spectrometers an UV microspectrometer was used. Obtained results are compared to the results from satellite measurements. This comparison showed agreement inside 10 % in average.

  15. Use of B-mode ultrasonography for measuring femoral muscle thickness in dogs

    Science.gov (United States)

    SAKAEDA, Kanako; SHIMIZU, Miki

    2016-01-01

    Assessment of muscle mass is important for evaluating muscle function and rehabilitation outcomes. Ultrasound has recently been successfully used to estimate muscle mass in humans by measuring muscle thickness. This study attempted to standardize procedures for measuring femoral muscle thickness ultrasonographically, as well as quantify the reliability and validity of ultrasound evaluations of muscle thickness compared to measurements made by magnetic resonance imaging (MRI) in dogs. We evaluated the quadriceps femoris (QF), biceps femoris (BF), semitendinosus (ST) and semimembranosus (SM) muscles of 10 clinically healthy Beagle dogs. Scans were taken in 5 different sections divided equally between the greater trochanter and proximal patella. MRI was performed, followed by T1-weighted and contrast-enhanced T1-weighted imaging. Muscle cross-sectional area (CSA) was measured with MRI, and muscle thickness was measured with MRI and ultrasonography. The thickness of the QF, BF and ST muscles as measured by ultrasound at slices 1–3 (from the proximal end to the middle of the femur), 2–4 (middle of the femur) and 2 (more proximal than the middle of the femur), respectively, was correlated with muscle thickness and CSA as measured by MRI. These sites showed a flat interface between muscle and transducer and were situated over belly muscle. No correlation between measurement types was seen in SM muscle. We must confirm this assessment method for various breeds, sizes, ages and muscle pathologies in dogs, thereby confirming that muscle thickness as measured ultrasonographically can reflect muscle function. PMID:26832997

  16. Measurement of epidermal thickness in a patient with psoriasis by computer-supported image analysis

    OpenAIRE

    Alper, M; A. Kavak; A.H. Parlak; R. Demirci; I. Belenli; N. Yesildal

    2004-01-01

    The aim of the present study was to measure full epidermal thickness, stratum corneum thickness, rete length, dermal papilla widening and suprapapillary epidermal thickness in psoriasis patients using a light microscope and computer-supported image analysis. The data obtained were analyzed in terms of patient age, type of psoriasis, total body surface area involvement, scalp and nail involvement, duration of psoriasis, and family history of the disease. The study was conducted on 64 patients ...

  17. Measurement of Nuchal Translucency Thickness for Detection of Chromosomal Abnormalities using First Trimester Ultrasound Fetal Images

    CERN Document Server

    Nirmala, S

    2010-01-01

    The Nuchal Translucency thickness measurement is made to identify the Down Syndrome in screening first trimester fetus and presented in this paper. The mean shift analysis and canny operators are utilized for segmenting the nuchal translucency region and the exact thickness has been estimated using Blob analysis. It is observed from the results that the fetus in the 14th week of Gestation is expected to have a nuchal translucency thickness of 1.87 plus or minus 0.25mm.

  18. Quantitative materials analysis of micro devices using absorption-based thickness measurements

    International Nuclear Information System (INIS)

    Preliminary work in designing an X-ray inspection machine with the capability of providing quantitative thickness analysis based on absorption measurements has been demonstrated. This study attempts to use the gray levels data to investigate the nature and thickness of occluded features and materials within devices. The investigation focused on metallic materials essential to semiconductor and MEMS technologies such as tin, aluminium, copper, silver, iron and zinc. The materials were arranged to simulate different feature thicknesses and sample geometries. The X-ray parameters were varied in-order to modify the X-ray energy spectrum with the aim of optimising the measurement conditions for each sample. The capability of the method to resolve differences in thicknesses was found to be highly dependent on the material. The thickness resolution with aluminium was the poorest due to its low radiographic density. The thickness resolutions achievable for silver and tin were significantly better and of the order of 0.015 mm and 0.025 mm respectively. From the linear relationship between the X-ray attenuation and sample thickness established, the energy dependent linear attenuation coefficient for each material was determined for a series of specific energy spectra. A decrease in the linear attenuation coefficient was observed as the applied voltage and thickness of the material increased. The results provide a platform for the development of a novel absorption-based thickness measurement system that can be optimised for a range of industrial applications

  19. Prophylactic administration of Amifostine protects vessel thickness in the setting of irradiated bone.

    Science.gov (United States)

    Page, Erin E; Deshpande, Sagar S; Nelson, Noah S; Felice, Peter A; Donneys, Alexis; Rodriguez, Jose J; Deshpande, Samir S; Buchman, Steven R

    2015-01-01

    Although often beneficial in the treatment of head and neck cancer (HNC), radiation therapy (XRT) leads to the depletion of vascular supply and eventually decreased perfusion of the tissue. Specifically, previous studies have demonstrated the depletion of vessel volume fraction (VVF) and vessel thickness (VT) associated with XRT. Amifostine (AMF) provides protection from the detrimental effects of radiation damage, allowing for reliable post-irradiation fracture healing in the murine mandible. The purpose of this study is to investigate the prophylactic ability of AMF to protect the vascular network in an irradiated field. Sprague-Dawley rats (n = 17) were divided into 3 groups: control (C, n = 5), radiated (XRT, n = 7), and radiated mandibles treated with Amifostine (AMF XRT, n = 5). Both groups receiving radiation underwent a previously established, human equivalent dose of XRT totaling 35 Gy, equally fractionated over 5 days. The AMF XRT group received a weight dependent (0.5 mg AMF/5 g body weight) subcutaneous injection of AMF 45 min prior to XRT. Following a 56-day recovery period, mandibles were perfused, dissected, and imaged with μCT. ANOVA was used for comparisons between groups and p < 0.05 was considered statistically significant. Stereologic analysis demonstrated a significant and quantifiable restoration of VT in AMF treated mandibles as compared to those treated with radiation alone (0.061 ± 0.011 mm versus 0.042 ± 0.004 mm, p = 0.027). Interestingly, further analysis demonstrated no significant difference in VT between control mandibles and those treated with AMF (0.067 ± 0.016 mm versus 0.061 ± 0.011 mm, p = 0.633). AMF treatment also showed an increase in VVF, however those results were not statistically significant from VVF values demonstrated by the XRT group. Our data support the contention that AMF therapy acts prophylactically to protect vessel thickness. Based on these findings, we support the continued

  20. Reliability of Various Measurement Stations for Determining Plantar Fascia Thickness and Echogenicity.

    Science.gov (United States)

    Bisi-Balogun, Adebisi; Cassel, Michael; Mayer, Frank

    2016-01-01

    This study aimed to determine the relative and absolute reliability of ultrasound (US) measurements of the thickness and echogenicity of the plantar fascia (PF) at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet) were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was performed using Image J, a digital image analysis and viewer software. A sonography evaluation of the thickness and echogenicity of the PF showed a high relative reliability with an Intra class correlation coefficient of ≥0.88 at all measurement stations. However, the measurement stations for both the PF thickness and echogenicity which showed the highest intraclass correlation coefficient (ICCs) did not have the highest absolute reliability. Compared to other measurement stations, measuring the PF thickness at 3 cm distal and the echogenicity at a region of interest 1 cm to 2 cm distal from its insertion at the medial calcaneal tubercle showed the highest absolute reliability with the least systematic bias and random error. Also, the reliability was higher using a mean of three measurements compared to one measurement. To reduce discrepancies in the interpretation of the thickness and echogenicity measurements of the PF, the absolute reliability of the different measurement stations should be considered in clinical practice and research rather than the relative reliability with the ICC. PMID:27089369

  1. Reliability of Various Measurement Stations for Determining Plantar Fascia Thickness and Echogenicity

    Directory of Open Access Journals (Sweden)

    Adebisi Bisi-Balogun

    2016-04-01

    Full Text Available This study aimed to determine the relative and absolute reliability of ultrasound (US measurements of the thickness and echogenicity of the plantar fascia (PF at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was performed using Image J, a digital image analysis and viewer software. A sonography evaluation of the thickness and echogenicity of the PF showed a high relative reliability with an Intra class correlation coefficient of ≥0.88 at all measurement stations. However, the measurement stations for both the PF thickness and echogenicity which showed the highest intraclass correlation coefficient (ICCs did not have the highest absolute reliability. Compared to other measurement stations, measuring the PF thickness at 3 cm distal and the echogenicity at a region of interest 1 cm to 2 cm distal from its insertion at the medial calcaneal tubercle showed the highest absolute reliability with the least systematic bias and random error. Also, the reliability was higher using a mean of three measurements compared to one measurement. To reduce discrepancies in the interpretation of the thickness and echogenicity measurements of the PF, the absolute reliability of the different measurement stations should be considered in clinical practice and research rather than the relative reliability with the ICC.

  2. Simultaneous Measurement of Ultrasonic Velocity and Thickness of Isotropic and Homogeneous Solids Using Two Transducers

    International Nuclear Information System (INIS)

    Ultrasonic pulse-echo methods measuring the transit time through specimens have been widely used in determination of ultrasonic velocity and thickness of specimens. Usually, to determine the velocity of the ultrasonic. Tthe transit time of the ultrasonic pulse through specimen is measured by using the ultrasonic measuring equipment such as the oscilloscope including ultrasonic pulser/receiver and the thickness of the specimen is measured by using the length measuring instrument such as micrometer or vernier calipers etc., i. e. each parameter is measured by using each measuring method. In the case of the measuring the thickness of a specimen by using the ultrasonics. the ultrasonic equipment, which measure the thickness, such as the ultrasonic thickness gauge must be calibrated by using the reference block of which the ultrasonic velocity is known beforehand. In the present work, we proposed a new method for simultaneous measurement of ultrasonic velocity and thickness without reference blocks. Experimental results for several specimens show that proposed method have good agreements with those by traditional ultrasonic method

  3. Optimization of Focal Position of Ultrasonic Beam in Measurement of Small Change in Arterial Wall Thickness

    Science.gov (United States)

    Watanabe, Masaru; Kanai, Hiroshi

    2001-05-01

    We have previously developed a method for measurement of a small change in thickness of the arterial wall during a single cardiac cycle [H. Kanai, M. Sato, Y. Koiwa and N. Chubachi: IEEE Trans. UFFC 43 (1996) 791]. The resultant change in thickness is shown to be useful for the in vivo assessment of the regional elasticity of the arterial wall. Although the accuracy of the measurement of the change in thickness is found to be within 1 μm, it is affected by the interference of ultrasonic pulses. In this study, we simulate the propagation of ultrasonic pulses transmitted and received by a linear probe. In the simulation experiments, the ultrasonic pulses generated by a computer are reflected by a tube, which has a small change in wall thickness of 10 μm. The optimum focal position of the ultrasonic beam is determined by evaluating the root-mean-square (rms) error in the measured change in thickness.

  4. Estimation of Birth Weight Using Sono-graphically Measured Fetal Abdominal Subcutaneous Tissue Thickness

    Directory of Open Access Journals (Sweden)

    A. Forouzmehr

    2004-06-01

    Full Text Available Background/Objectives: Growth retardation and macrosomia are associated with increased fetal morbidity and mortality. We assessed the usefulness of sonographic measurement of abdominal subcuta-neous tissue thickness in estimating birth weight. Materials and Methods: Abdominal subcutaneous tissue thickness was measured sono-graphically in 300 fetuses between 37 and 42 weeks of gestation. The median time between sonographic examination and delivery was 11 days. The weight of newborns was measured immediately after delivery. Results: The mean soft tissue thickness was significantly higher in macrosomic than normal fetuses (12.0±1.4 mm versus 6.6±1.6 mm, respectively; P < 0.001. There was a significant positive correlation between the abdominal subcutaneous tissue thickness and birth weight (r = 0.86, P < 0.001. Conclusion: Sonographic examination of the fetal abdominal subcutaneous tissue thickness is useful for estimating birth weight.

  5. Trabecular bone mineral density measured by quantitative CT of the lumbar spine in children and adolescents: reference values and peak bone mass

    International Nuclear Information System (INIS)

    Purpose: The aim of this study was to assess bone density values in the trabecular substance of the lumbar vertebral column in children and young adults in Germany from infancy to the age of peak bone mass. Materials and Methods: We performed quantiative computed tomography (QCT) on the first lumbar vertebra in 28 children and adolescents without diseases that may influence bone metabolism (15 boys, 13 girls, mean ages 11 and 8 years, respectively). We also measured 17 healthy young adults (9 men, 8 women, mean ages 20 and 21 years). We used a Somatom Balance Scanner (Siemens, Erlangen) and the Siemens Osteo software. Scan parameters: Slice thickness 1 cm, 80 kV, 81 or 114 mAs. We measured the trabecular bone density and the area and height of the vertebra and calculated the volume and content of calcium hydroxyapatite (Ca-HA) in the trabecular substance of the first lumbar vertebra. Results: Prepubertal boys had a mean bone density of 148.5 (median [med] 150.1, standard deviation [SD] 15.4) mg/Ca-HA per ml bone, and prepubertal girls had a mean density of 149.5 (med 150.8, SD 23.5) mg/ml. We did not observe a difference between prepubertal boys and girls. After puberty there was a significant difference (p<0.001) between males and females: Mean density (male) 158.0, med 162.5, SD 24.0 mg/ml, mean density (female) 191.2, med 191.3, SD 17.7 mg/ml. The Ca-HA content in the trabecular bone of the first lumbar vertebra was 1.1 (med 1.1, SD 0.5) g for prepubertal boys and 1.1 (0.9, 0.4) g for prepubertal girls. For post-pubertal males, the mean Ca-HA content was 3.5 g, med 3.5 SD 0.5 g, and for post-pubertal females, the mean content was 2.8, med 2.7, SD 0.4 g. Conclusion: The normal trabecular bone mineral density is 150 mg/ml with a standard deviation of 20 mg/ml independent of age or gender until the beginning of puberty. Peak bone mass (bone mineral content) in the trabecular substance of the lumbar vertebral column is higher in males than in females, and peak bone

  6. Continuous measurement of fiber reinforcement permeability in the thickness direction: Experimental technique and validation

    OpenAIRE

    Ouagne, P.; Ouahbi, Tariq; Park, Chung Hae; Bréard, Joël; Saouab, Abdelghani

    2013-01-01

    International audience It is an important topic to measure the through-thickness permeability of fiber reinforcements as the resin flow in the thickness direction is widely employed in many composites manufacturing techniques. Continuous techniques for the permeability measurement by simultaneous fabric compaction and liquid flow have been recently proposed as an alternative way to the tedious and laborious conventional permeability measurement techniques. In spite of their efficiencies, t...

  7. Extraordinarily thick-boned fish linked to the aridification of the Qaidam Basin (northern Tibetan Plateau).

    Science.gov (United States)

    Chang, Meemann; Wang, Xiaoming; Liu, Huanzhang; Miao, Desui; Zhao, Quanhong; Wu, Guoxuan; Liu, Juan; Li, Qiang; Sun, Zhencheng; Wang, Ning

    2008-09-01

    Scattered with numerous salt lakes and approximately 2,700-3,200 m above sea level, the giant Qaidam inland basin on the northern Tibetan Plateau has experienced continuing aridification since the beginning of the Late Cenozoic as a result of the India-Asia plate collision and associated uplift of the Tibetan Plateau. Previous evidence of aridification comes mainly from evaporite deposits and salinity-tolerant invertebrate fossils. Vertebrate fossils were rare until recent discoveries of abundant fish. Here, we report an unusual cyprinid fish, Hsianwenia wui, gen. et sp. nov., from Pliocene lake deposits of the Qaidam Basin, characterized by an extraordinarily thick skeleton that occupied almost the entire body. Such enormous skeletal thickening, apparently leaving little room for muscles, is unknown among extant fish. However, an almost identical condition occurs in the much smaller cyprinodontid Aphanius crassicaudus (Cyprinodonyiformes), collected from evaporites exposed along the northern margins of the Mediterranean Sea during the Messinian desiccation period. H. wui and A. crassicaudus both occur in similar deposits rich in carbonates (CaCO(3)) and sulfates (CaSO(4)), indicating that both were adapted to the extreme conditions resulting from the aridification in the two areas. The overall skeletal thickening was most likely formed through deposition of the oversaturated calcium and was apparently a normal feature of the biology and growth of these fish. PMID:18757732

  8. Bone microdamage monitoring by nonlinear resonant ultrasound spectroscopy : towards quantitative measurements

    OpenAIRE

    Haupert, Sylvain

    2012-01-01

    Bone microdamage characterization as well as its involvement in bone metabolism or bone fragility remains a challenge, especially because no existing techniques are well suited to its measurement. Non invasive techniques for detecting and monitoring bone microcracks accumulation and propagation are thus highly desirable. The objective of this thesis was to evaluate the sensitivity of nonlinear resonant ultrasound spectroscopy (NRUS) measurements to the accumulation of damage in cortical bone ...

  9. Sonographic Measurement of AP Diameter and Wall Thickness of the Gallbladder

    International Nuclear Information System (INIS)

    Call bladder size and wall thickness are important in the assessment of the pathologic condition. Authors have measured AP diameter of gallbladder and evaluated the change of all thickness between fasting and postprandial state. The results were as follows: 1. The mean of AP diameter was 2.18+0.49cm 2. The wall thickness was 2.7+0.6mm in fasting state and 3.3+0.8mm after meal. 3. The increase of wall thickness after fat meal was significant statistically(p<.001)

  10. Macular thickness and macular volume measurements using spectral domain optical coherence tomography in normal Nepalese eyes

    Science.gov (United States)

    Pokharel, Amrit; Shrestha, Gauri Shankar; Shrestha, Jyoti Baba

    2016-01-01

    Purpose To record the normative values for macular thickness and macular volume in normal Nepalese eyes. Methods In all, 126 eyes of 63 emmetropic subjects (mean age: 21.17±6.76 years; range: 10–37 years) were assessed for macular thickness and macular volume, using spectral domain-optical coherence tomography over 6×6 mm2 in the posterior pole. A fast macular thickness protocol was employed. Statistics such as the mean, median, standard deviation, percentiles, and range were used, while a P-value was set at 0.05 to test significance. Results Average macular thickness and total macular volume were larger in males compared to females. With each year of increasing age, these variables decreased by 0.556 μm and 0.0156 mm3 for average macular thickness and total macular volume, respectively. The macular thickness was greatest in the inner superior section and lowest at the center of the fovea. The volume was greatest in the outer nasal section and thinnest in the fovea. The central subfield thickness (r=−0.243, P=0.055) and foveal volume (r=0.216, P=0.09) did not correlate with age. Conclusion Males and females differ significantly with regard to macular thickness and macular volume measurements. Reports by other studies that the increase in axial length reduced thickness and volume, were negated by this study which found a positive correlation among axial length, thickness, and volume. PMID:27041990

  11. Accuracy of measurement of thickness of a 6061 aluminum sample at 1-mm lift off

    International Nuclear Information System (INIS)

    The accuracy of measurement of a 0.51-mm thick, 6061 aluminum sample under lift-off variations of 0.25 mm at 1.08 is shown to be 5 percent by means of a complex-reluctance plane analysis. The analysis is shown to depend critically on the statistical accuracy of such measurements. Large lift-off measurements of aluminum thickness with large lift-off variations can be important for measurement of samples with radii of curvature such as aluminum cans, for measurements of sheets in rolling mills, and for reducing measurement problems in automatic scanning of aircraft skins where corrosion or spalling may have occurred

  12. Measurement of thickness of austenitic overlays on carbon steel walls using a magnetic method

    International Nuclear Information System (INIS)

    Mechanical and magnetic methods are used for measuring the thickness of austenitic overlays on the walls of carbon steel pressure vessels. Specific problems pertaining to the magnetic methods are briefly discussed. A magnetic thickness gage has been developed for overlays using the principle of ferrite effect suppression. Thickness gaging is done by aligning the gage with the layer to be measured on the overlay side. Basic accuracy of the instrument is 7% for overlays containing 2 to 8% ferrite. For the ferrite content 0 to 2% or 8 to 10%, accuracy reduces to roughly 12%. The method is simple, reliable and versatile during the manufacture of a pressure vessel and after it is finished. The economic benefit is considerable because it allows overlaying of a thickness which practically is without reserve; each millimeter of the austenitic layer thickness on the pressure vessel costs more than a million Czechoslovak crowns. (Z.M.). 7 figs., 5 refs

  13. Reliability assessment for thickness measurements of pipe wall using probability of detection

    International Nuclear Information System (INIS)

    This paper proposes a reliability assessment method for thickness measurements of pipe wall using probability of detection (POD). Thicknesses of pipes are measured by qualified inspectors with ultrasonic thickness gauges. The inspection results are affected by human factors of the inspectors and include some errors, because the inspectors have different experiences and frequency of inspections. In order to ensure reliability for inspection results, first, POD evaluates experimental results of pipe-wall thickness inspection. We verify that the results have differences depending on inspectors including qualified inspectors. Second, two human factors that affect POD are indicated. Finally, it is confirmed that POD can identify the human factors and ensure reliability for pipe-wall thickness inspections. (author)

  14. Analysis of variance on thickness and electrical conductivity measurements of carbon nanotube thin films

    Science.gov (United States)

    Li, Min-Yang; Yang, Mingchia; Vargas, Emily; Neff, Kyle; Vanli, Arda; Liang, Richard

    2016-09-01

    One of the major challenges towards controlling the transfer of electrical and mechanical properties of nanotubes into nanocomposites is the lack of adequate measurement systems to quantify the variations in bulk properties while the nanotubes were used as the reinforcement material. In this study, we conducted one-way analysis of variance (ANOVA) on thickness and conductivity measurements. By analyzing the data collected from both experienced and inexperienced operators, we found some operation details users might overlook that resulted in variations, since conductivity measurements of CNT thin films are very sensitive to thickness measurements. In addition, we demonstrated how issues in measurements damaged samples and limited the number of replications resulting in large variations in the electrical conductivity measurement results. Based on this study, we proposed a faster, more reliable approach to measure the thickness of CNT thin films that operators can follow to make these measurement processes less dependent on operator skills.

  15. Capacitive Extensometer Particularly Suited for Measuring in Vivo Bone Strain

    Science.gov (United States)

    Perusek, Gail P. (Inventor)

    2000-01-01

    The present invention provides for in vivo measurements of the principal strain magnitudes and directions, and maximum shear strain that occurs in a material, such as human bone, when it is loaded (or subjected to a load). In one embodiment the invention includes a capacitive delta extensometer arranged with six sensors in a three piece configuration, with each sensor of each pair spaced apart from each other by 120 degrees.

  16. Retinal nerve fiber layer thickness in normal Indian pediatric population measured with optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Neelam Pawar

    2014-01-01

    Full Text Available Purpose: To measure the peripapillary retinal nerve fiber layer (RNFL thickness in normal Indian pediatric population. Subjects and Methods: 120 normal Indian children ages 5-17 years presenting to the Pediatric Clinic were included in this observational cross-sectional study. RNFL thickness was measured with stratus optical coherence tomography (OCT. Children with strabismus or amblyopia, with neurological, metabolic, vascular, or other disorders and those with abnormal optic discs were excluded. One eye of each subject was randomly selected for statistical analysis. The effect of age, refraction and gender on RNFL thickness was investigated statistically. Result: OCT measurements were obtained in 120 of 130 (92.3% subjects. Mean age was 10.8 ± 3.24 years (range 5-17. Average RNFL thickness was (± SD 106.11 ± 9.5 μm (range 82.26-146.25. The RNFL was thickest inferiorly (134.10 ± 16.16 μm and superiorly (133.44 ± 15.50 μm, thinner nasally (84.26 ± 16.43 μm, and thinnest temporally (70.72 ± 14.80 μm. In univariate regression analysis, age had no statistical significant effect on RNFL thickness (P = 0.7249 and refraction had a significant effect on RNFL thickness (P = 0.0008. Conclusion: OCT can be used to measure RNFL thickness in children. Refraction had an effect on RNFL thickness. In normal children, variation in RNFL thickness is large. The normative data provided by this study may assist in identifying changes in RNFL thickness in Indian children.

  17. Automatic measuring system of zirconium thickness for zirconium liner cladding tubes

    International Nuclear Information System (INIS)

    An automatic system of pure zirconium liner thickness for zirconium-zircaloy cladding tubes has been successfully developed. The system consists of three parts. (1) An ultrasonic thickness measuring method for mother tubes before cold rolling. (2) An electromagnetic thickness measuring method for the manufactured tubes. (3) An image processing method for the cross sectional view of the manufactured cut tube samples. In Japanese nuclear industry, zirconium-zircaloy cladding tubes have been tested in order to realize load following operation in the atomic power plant. In order to provide for the practical use in the near future, Sumitomo Metal Industries, Ltd. has been studied and established the practical manufacturing process of the zirconium liner cladding tubes. The zirconium-liner cladding tube is a duplex tube comprising an inner layer of pure zirconium bonded to zircaloy metallurgically. The thickness of the pure zirconium is about 10 % of the total wall thickness. Several types of the automatic thickness measuring methods have been investigated instead of the usual microscopic viewing method in which the liner thickness is measured by the microscopic cross sectional view of the cut tube samples

  18. Reliability of Various Measurement Stations for Determining Plantar Fascia Thickness and Echogenicity

    OpenAIRE

    Adebisi Bisi-Balogun; Michael Cassel; Frank Mayer

    2016-01-01

    This study aimed to determine the relative and absolute reliability of ultrasound (US) measurements of the thickness and echogenicity of the plantar fascia (PF) at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet) were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was perf...

  19. Acoustic measurement of lubricant-film thickness distribution in ball bearings

    OpenAIRE

    Zhang, J.; Drinkwater, B. W.; Dwyer-Joyce, R.S.

    2006-01-01

    An oil-film thickness monitoring system capable of providing an early warning of lubrication failure in rolling element bearings has been developed. The system is used to measure the lubricant-film thickness in a conventional deep groove ball bearing (shaft diameter 80 mm, ball diameter 12.7 mm). The measurement system comprises a 50 MHz broadband ultrasonic focused transducer mounted on the static outer raceway of the bearing. Typically the lubricant-films in rolling element bearings are bet...

  20. Quantitative CT measures of emphysema and airway wall thickness are related to D(L)CO

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Thorsen, Einar; Dirksen, Asger;

    2011-01-01

    There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness.......There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness....

  1. Effect of image quality on tissue thickness measurements obtained with spectral-domain optical coherence tomography◊

    OpenAIRE

    Balasubramanian, Madhusudhanan; Bowd, Christopher; Vizzeri, Gianmarco; Weinreb, Robert N.; Zangwill, Linda M.

    2009-01-01

    The purpose of this study was to investigate the effect of image quality on retinal nerve fiber layer (RNFL) and retinal thickness measurements obtained using three commercially available spectral-domain optical coherence tomographers (SD-OCT). Subjectively determined good, medium and poor quality images were obtained from four healthy and one glaucoma suspect eyes. RNFL and retinal thickness measurements were compared as a function of image quality. Results indicate that when image quality i...

  2. Ultrasonic oil-film thickness measurement: An angular spectrum approach to assess performance limits

    OpenAIRE

    Zhang, J.; Drinkwater, B. W.; Dwyer-Joyce, R.S.

    2007-01-01

    The performance of ultrasonic oil-film thickness measurement in a ball bearing is quantified. A range of different viscosity oils (Shell T68, VG15, and VG5) are used to explore the lowest reflection coefficient and hence the thinnest oil-film thickness that the system can measure. The results show a minimum reflection coefficient of 0.07 for both oil VG15 and VG5 and 0.09 for oil T68 at 50 MHz. This corresponds to an oil-film thickness of 0.4 μm for T68 oil. An angular spectrum (or Fourier d...

  3. A large-scale comparison of cortical thickness and volume methods for measuring Alzheimer's disease severity

    Directory of Open Access Journals (Sweden)

    Christopher G. Schwarz

    2016-01-01

    Full Text Available Alzheimer's disease (AD researchers commonly use MRI as a quantitative measure of disease severity. Historically, hippocampal volume has been favored. Recently, “AD signature” measurements of gray matter (GM volumes or cortical thicknesses have gained attention. Here, we systematically evaluate multiple thickness- and volume-based candidate-methods side-by-side, built using the popular FreeSurfer, SPM, and ANTs packages, according to the following criteria: (a ability to separate clinically normal individuals from those with AD; (b (extent of correlation with head size, a nuisance covariatel (c reliability on repeated scans; and (d correlation with Braak neurofibrillary tangle stage in a group with autopsy. We show that volume- and thickness-based measures generally perform similarly for separating clinically normal from AD populations, and in correlation with Braak neurofibrillary tangle stage at autopsy. Volume-based measures are generally more reliable than thickness measures. As expected, volume measures are highly correlated with head size, while thickness measures are generally not. Because approaches to statistically correcting volumes for head size vary and may be inadequate to deal with this underlying confound, and because our goal is to determine a measure which can be used to examine age and sex effects in a cohort across a large age range, we thus recommend thickness-based measures. Ultimately, based on these criteria and additional practical considerations of run-time and failure rates, we recommend an AD signature measure formed from a composite of thickness measurements in the entorhinal, fusiform, parahippocampal, mid-temporal, inferior-temporal, and angular gyrus ROIs using ANTs with input segmentations from SPM12.

  4. A Computed Tomographic Study on the Size and Bone Wall Thickness of the Maxillary Sinus in Normal, Preoperative and Postoperative Maxillary Sinusitis Patients

    International Nuclear Information System (INIS)

    To compare the size and bone wall thickness of the maxillary sinus in normal, preoperative and postoperative maxillary sinusitis patients. The author analyzed CT images of both left and right maxillary sinuses in 357 patients who visited Chonbuk National University Hospital between January 1997 and December 1998. The size and bone wall thickness of the maxillary sinus of normal, inflammatory and post-Caldwell-Luc groups were compared. The significant differences of transverse, maximum medio-lateral, maximum supero-inferior dimensions and medio-lateral dimension at nasal floor level between normal and post-Caldwell-Luc groups were found (P0.05). The significant differences of postero-lateral, infero-lateral and medial wall thickness between normal and post-Caldwell-Luc groups were found (P<0.05). The results of this study will aid in the diagnosis and treatment of maxillary sinus diseases and post operative treatment planning.

  5. Measurement of bone mineral content by dual photon absorptiometry in patients with metabolic bone diseases

    Energy Technology Data Exchange (ETDEWEB)

    Ohtani, Masami; Hino, Megumu; Ikekubo, Katsuji (Kobe City General Hospital (Japan)) (and others)

    1991-12-01

    Dual photon absorptiometry was used to measure bone mineral content in 225 patients with metabolic bone diseases (84 males and 102 females) and 186 healthy subjects (25 males and 200 females). Mineral content of the lumbar vertebrae tended to rapidly decrease after the age of 40 in healthy female subjects. For males, gradual decrease in mineral content was associated with aging. Bone mineral content showed a correlation with the severity of osteoporosis as shown on X-ray films. Mineral content tended to be decreased in the lumbar vertebrae in patients with vertebral compression fracture, and in the femur in patients with vertebral or femoral fracture. For hyperthyroidism, mineral content of the lumbar vertebrae was decreased in some females, but was within normal limit in males. Hyperparathyroidism and hypoparathyroidism tended to be associated with decrease and increase in mineral content, respectively. Two each patients with osteomalacia or Cushing syndrome had a decreased mineral content. In these patients, it was increased after the treatment. (N.K.).

  6. Evaluation of cortical bone mass, thickness and density by z-scores in osteopenic conditions and in relation to menopause and estrogen treatment

    International Nuclear Information System (INIS)

    Z-scores express, differences from normals in standard deviation units, and are particularly useful for comparison of changes where normal values are age- and sex-dependent. We determined z-scores for bone mineral mass, cortical thickness, and bone mineral density in the radius in various conditions and diseases in both sexes. In the males, z-scores were calculated for age, but in the females z-scores for menopausal status (years postmenopausal exclusive of years on estrogen treatment) were found to be more appropriate. With few exceptions, changes in a disease were of a similar order in both sexes. For bone minerals mass few mean z-scores were significantly increased, but diseases with significantly decreased mean z-scores were numerous. The usefulness of z-scores in diagnosis and study of metabolic bone disease is discussed. (orig.)

  7. In situ non-destructive measurement of biofilm thickness and topology in an interferometric optical microscope.

    Science.gov (United States)

    Larimer, Curtis; Suter, Jonathan D; Bonheyo, George; Addleman, Raymond Shane

    2016-06-01

    Biofilms are ubiquitous and impact the environment, human health, dental hygiene, and a wide range of industrial processes. Biofilms are difficult to characterize when fully hydrated, especially in a non-destructive manner, because of their soft structure and water-like bulk properties. Herein a method of measuring and monitoring the thickness and topology of live biofilms of using white light interferometry is described. Using this technique, surface morphology, surface roughness, and biofilm thickness were measured over time without while the biofilm continued to grow. The thickness and surface topology of a P. putida biofilm were monitored growing from initial colonization to a mature biofilm. Measured thickness followed expected trends for bacterial growth. Surface roughness also increased over time and was a leading indicator of biofilm growth. PMID:26992071

  8. Nighttime measurements of atmospheric optical thickness by star photometry with a digital camera.

    Science.gov (United States)

    Lanciano, Orietta; Fiocco, Giorgio

    2007-08-01

    Nighttime stellar photometric measurements have been carried out with a commercial digital single-lens reflex camera to determine the atmospheric optical thickness on large fields of view (FOV). Specific procedures of image analysis allow to extract an equivalent irradiance for a number of stars and for the sky light background; thus, a measure of the optical thickness in each star direction can be retrieved. A larger FOV is obtained by stitching several photographs shot in quick sequence on adjacent regions of the sky: such measurements provide almost instantaneous maps of optical thickness and skylight background that indicate the degree of homogeneity of the aerosol load. Additional information provided by the combined use of the camera and a lidar is presented. The zenithal optical thickness is used with values of the aerosol backscatter provided by a lidar system to obtain the aerosol extinction-to-backscatter ratio. PMID:17676129

  9. Microscopic image processing system for measuring nonuniform film thickness profiles: Image scanning ellipsometry

    International Nuclear Information System (INIS)

    The long-term objective of this research program is to determine the stability and heat transfer characteristics of evaporating thin films. The current objective is to develop and use a microscopic image-processing system (IPS) which has two parts: an image analyzing interferometer (IAI) and an image scanning ellipsometer (ISE). The primary purpose of this paper is to present the basic concept of ISE, which is a novel technique to measure the two dimensional thickness profile of a non-uniform, thin film, from several nm up to several μm, in a steady state as well as in a transient state. It is a full-field imaging technique which can study every point on the surface simultaneously with high spatial resolution and thickness sensitivity, i.e., it can measure and map the 2-D film thickness profile. The ISE was tested by measuring the thickness profile and the refractive index of a nonuniform solid film

  10. Effects of through-thickness stress assumptions on residual stress measurements in welds

    International Nuclear Information System (INIS)

    Full text: The three normal stresses have been measured by neutron diffraction for girth welded rings cut from linepipe in a number of thicknesses. The welds are manual metal arc cellulosic electrode welds made in X70 linepipe, these were measured at 5 through thickness positions at 19 locations (from the center of the weld up to 35 mm away from the weld) with a spatial resolution of 1 mm3. The assumption of zero through thickness stress is a common one in thin walled tubes such as these, however there may be significant local through-thickness stresses depending on the welding technique. These local effects, and the change in measured stresses if these are included, are discussed. (authors)

  11. Evaluation of Lead Equivalence Thickness Measurement for Radiation Shielding Materials Used in Diagnostic Radiology

    International Nuclear Information System (INIS)

    Verification of lead equivalence thickness of radiation room and shielding material such as personal protective clothing are crucial to ensure that they fulfill their task in protecting patient and personnel as well as the member of public from ionizing radiation. The radiation room or shielding materials need to be verified according to Ministry of Health (MOH) requirements comply with a current standard. The thickness of the shielding materials is determined using direct comparison between the attenuation of X-ray or gamma ray by the shielding materials and high purity lead sheets (99.99 %). Currently Americium-241 is used to measure the thickness of the shielding materials for diagnostic X-ray room due to the gamma energy of 59 keV which is adequate to measure the thickness of 2 mmPb. However, the uncertainties of thickness getting higher for a thicker shielding materials due to so called a build-up factor. Various sizes of collimator and stronger radiation source were used to reduce the build-up factor and improve the accuracy of the lead equivalence thickness. From the measurement the accuracy of the thickness were increased when using a narrow beam and a stronger radiation source. (author)

  12. Absolute Thickness Measurements on Coatings Without Prior Knowledge of Material Properties Using Terahertz Energy

    Science.gov (United States)

    Roth, Don J.; Cosgriff, Laura M.; Harder, Bryan; Zhu, Dongming; Martin, Richard E.

    2013-01-01

    This study investigates the applicability of a novel noncontact single-sided terahertz electromagnetic measurement method for measuring thickness in dielectric coating systems having either dielectric or conductive substrate materials. The method does not require knowledge of the velocity of terahertz waves in the coating material. The dielectric coatings ranged from approximately 300 to 1400 m in thickness. First, the terahertz method was validated on a bulk dielectric sample to determine its ability to precisely measure thickness and density variation. Then, the method was studied on simulated coating systems. One simulated coating consisted of layered thin paper samples of varying thicknesses on a ceramic substrate. Another simulated coating system consisted of adhesive-backed Teflon adhered to conducting and dielectric substrates. Alumina samples that were coated with a ceramic adhesive layer were also investigated. Finally, the method was studied for thickness measurement of actual thermal barrier coatings (TBC) on ceramic substrates. The unique aspects and limitations of this method for thickness measurements are discussed.

  13. Macular thickness and macular volume measurements using spectral domain optical coherence tomography in normal Nepalese eyes

    Directory of Open Access Journals (Sweden)

    Pokharel A

    2016-03-01

    Full Text Available Amrit Pokharel,1 Gauri Shankar Shrestha,2 Jyoti Baba Shrestha2 1Department of Ophthalmology, Kathmandu Medical College Teaching Hospital, 2B P Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine, Kathmandu, Nepal Purpose: To record the normative values for macular thickness and macular volume in normal Nepalese eyes. Methods: In all, 126 eyes of 63 emmetropic subjects (mean age: 21.17±6.76 years; range: 10–37 years were assessed for macular thickness and macular volume, using spectral domain-optical coherence tomography over 6×6 mm2 in the posterior pole. A fast macular thickness protocol was employed. Statistics such as the mean, median, standard deviation, percentiles, and range were used, while a P-value was set at 0.05 to test significance. Results: Average macular thickness and total macular volume were larger in males compared to females. With each year of increasing age, these variables decreased by 0.556 µm and 0.0156 mm3 for average macular thickness and total macular volume, respectively. The macular thickness was greatest in the inner superior section and lowest at the center of the fovea. The volume was greatest in the outer nasal section and thinnest in the fovea. The central subfield thickness (r=-0.243, P=0.055 and foveal volume (r=0.216, P=0.09 did not correlate with age. Conclusion: Males and females differ significantly with regard to macular thickness and macular volume measurements. Reports by other studies that the increase in axial length reduced thickness and volume, were negated by this study which found a positive correlation among axial length, thickness, and volume. Keywords: macular thickness, macular volume, optical coherence tomography, Nepal

  14. Comparison between Carotid Artery Wall Thickness Measured by Multidetector Row Computed Tomography Angiography and Intimae-Media Thickness Measured by Sonography

    Directory of Open Access Journals (Sweden)

    Živorad N. Savić

    2011-01-01

    Full Text Available The increased thickness of the carotid wall >1 mm is a significant predictor of coronary and cerebrovascular diseases. The purpose of our study was to assess the agreement between multidetector row computed tomography angiography (MDCTA in measuring carotid artery wall thickness (CAWT and color Doppler ultrasound (CD-US in measuring intimae-media thickness (IMT. Eighty-nine patients (aged 35–81 were prospectively analyzed using a 64-detector MDCTA and a CD-US scanner. Continuous data were described as the mean value ± standard deviation, and were compared using the Mann–Whitney U test. A p value <0.05 was considered significant. Bland–Altman statistics were employed to measure the agreement between MDCTA and CD-US. CAWT ranged from 0.62 to 1.60 mm, with a mean value of 1.09 mm. IMT ranged from 0.60 to 1.55 mm, with a mean value of 1.06 mm. We observed an excellent agreement between CD-US and MDCTA in the evaluation of the common carotid artery thickness, with a bias between methods of 0.029 mm (which is a highly statistically important difference of absolute values [t = 43.289; p < 0.01] obtained by paired T test, and limits of agreement from 0.04 to 0.104. Pearson correlation coefficient was 0.9997 (95% CI 0.9996–0.9998; p < 0.01. We conclude that there is an excellent correlation between CAWT and IMT measurements obtained with the MDCTA and CD-US.

  15. Remote thickness measurement of oil slicks on water by laser-ultrasonics

    International Nuclear Information System (INIS)

    At the National Research Council of Canada Industrial Materials Institute, research is in progress on the application of laser-ultrasonics to remote measurement of the thickness of oil on water. Laser-ultrasonics is a novel technique developed for the nondestructive inspection of materials. It uses a short pulse laser for the generation of ultrasonic waves in the oil layer and a second laser, coupled to an optical interferometer, for the remote detection of the ultrasonic surface motion. Direct measurement of the time of flight of the ultrasonic wave provides the value of the thickness of the oil layer. Application of this technique to thickness measurement of oil on water has been studied in small and large scale laboratory tests. Small scale tests demonstrate the direct and unambiguous determination of the oil layer thickness. Accuracy is essentially limited by the knowledge of the acoustic properties of the oil. Large scale tests show that a distance of almost 37 meters does not severely impede the method, so air borne application appears possible. Surface motion such as that caused by sea waves does not reduce the accuracy of the thickness determination but does limit the measurement rate. Preliminary airborne tests with a single laser probe confirm that laser-ultrasonics monitoring of the thickness of an oil spill is feasible

  16. Ultrasonic Measurement of Interfacial Layer Thickness of Sub-Quarter-Wavelength

    International Nuclear Information System (INIS)

    This paper describes a new technique for thickness measurement of a very thin layer less than one-quarter of the wavelength of ultrasonic wave used in the ultrasonic pulse-echo measurements. The technique determines the thickness of a thin layer in a tapered medium from constructive interference of multiple reflection waves. The interference characteristics are derived and investigated in theoretical and experimental approaches. Modified total reflection wave g(t) defined as difference between total and first reflection waves increases in amplitude as the interfacial layer thickness decreases down to zero. A layer thickness less than one-tenth of the ultrasonic wavelength is measured using the maximum amplitude of g(t) with a good accuracy and sensitivity. The method also requires no inversion process to extract the thickness information from the waveforms of reflected waves, so that it makes possible to have the on-line thickness measurement of a thin layer such as a lubricating oil film in thrust bearings and journal bearings during manufacturing process

  17. Measurement and clinical implications of choroidal thickness in patients with inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Ibrahim Koral Onal

    2015-10-01

    Full Text Available ABSTRACTPurpose:Ocular inflammation is a frequent extraintestinal manifestation of inflammatory bowel disease (IBD and may parallel disease activity. In this study, we evaluated the utility of a choroidal thickness measurement in assessing IBD activity.Methods:A total of 62 eyes of 31 patients with IBD [Crohn's disease (CD, n=10 and ulcerative colitis (UC, n=21] and 104 eyes of 52 healthy blood donors were included in this study. Choroidal thickness was measured using enhanced depth imaging optical coherence tomography. The Crohn's disease activity index (CDAI and the modified Truelove Witts score were used to assess disease activity in CD and UC, respectively.Results:No significant differences in mean subfoveal, nasal 3000 μm, or temporal 3000 μm choroidal thickness measurements (P>0.05 for all were observed between IBD patients and healthy controls. Age, smoking, CD site of involvement (ileal and ileocolonic involvement, CDAI, CD activity, and UC endoscopic activity index were all found to be significantly correlated with choroidal thickness by univariate analysis (P<0.05. Smoking (P<0.05 and the CD site of involvement (P<0.01 were the only independent parameters associated with increased choroidal thickness at all measurement locations.Conclusions:Choroidal thickness is not a useful marker of disease activity in patients with IBD but may be an indicator of ileal involvement in patients with CD.

  18. Water-side oxide layer thickness measurement of the irradiated PWR fuel rod by NDT method

    International Nuclear Information System (INIS)

    It has been known that water-side corrosion of fuel rods in nuclear reactor is accompanied with the loss of metallic wall thickness and pickup of hydrogen. This corrosion is one of the important limiting factors in the operating life of fuel rods. In connection with the fuel cladding corrosion, a device to measure the water-side oxide layer thickness by means of the eddy-current method without destructing the fuel rod was developed by KAERI. The device was installed on the multi-function testing bench in the nondestructive test hot-cell and its calibration was carried out successfully for the standard rod attached with plastic thin films whose thicknesses are predetermined. It shows good precision within about 10% error. And a PWR fuel rod, one of the J-44 assembly discharged from Kori nuclear power plant Unit-2, has been selected for oxide layer thickness measurements. With the result of data analysis, it appeared that the oxide layer thicknesses of Zircaloy cladding vary with the length of the fuel rod, and their thicknesses were compared with those of the destructive test results to confirm the real thicknesses

  19. Refractive index gradient measurement across the thickness of a dielectric film by the prism coupling method

    International Nuclear Information System (INIS)

    A method is proposed for measuring the refractive index gradient n(z) in nonuniformly thick dielectric films. The method is based on the excitation of waveguide modes in a film using the prism coupling technique and on the calculation of n(z) and film thickness Hf with the help of the angular positions of the TE or TM modes. The method can be used for an arbitrary shape of the index modulation over the film thickness in the limit of a small gradient [Δ n(z)/n(z) || 1]. (laser applications and other topics in quantum electronics)

  20. A new approach to alloy compensation in a thickness measurement of high-tensile steel

    International Nuclear Information System (INIS)

    In on-line manufacturing iron-making process, several kinds of element are mixed in iron in order to meet the required quality for a final product. In this paper, the results show that the alloy compensation method is needed to improve accuracy required at thickness gauge, that is, ±0.5% at the target thickness. In addition, the alloy compensation method in measurement will be proposed in the form of correction function of each element weight percentage to be alloyed using the analyzed result of MCNP simulation program. Finally, an automatic thickness compensation method applied to the high-tensile steel product during manufacturing is introduced. (authors)

  1. Quantification of spatial structure of human proximal tibial bone biopsies using 3D measures of complexity

    DEFF Research Database (Denmark)

    Saparin, Peter I.; Thomsen, Jesper Skovhus; Prohaska, Steffen; Zaikin, Alexei; Kurths, Jürgen; Hege, H.-C.; Gowin, Wolfgang

    3D data sets of human tibia bone biopsies acquired by a micro-CT scanner. In order to justify the newly proposed approach, the measures of complexity of the bone architecture were compared with the results of traditional 2D bone histomorphometry. The proposed technique is able to quantify the......Changes in trabecular bone composition during development of osteoporosis are used as a model for bone loss in microgravity conditions during a space flight. Symbolic dynamics and measures of complexity are proposed and applied to assess quantitatively the structural composition of bone tissue from...

  2. Liquid film thickness measurement in small square pipe using ultrasonic pulse-echo method

    International Nuclear Information System (INIS)

    The ultrasonic pulse-echo method is applied to measure thickness in a liquid film. To prevent a piezoelectric element cracking under high temperature conditions, the maximum frequency of sound is limited. On the other hand, the required thickness resolution is about 0.05mm to detect whether or not dryout has occurred. An ultrasonic transducer frequency of 5MHz is selected to satisfy both frequency and resolution requirements for air-water experiments. The changing liquid film thickness on a stainless steel plate is simultaneously measured with the ultrasonic transducer and a laser displacement sensor. The two types of results show good agreement within the range from 0.06 to 0.22mm. Next, the air-water annular flow in the small vertical square pipe is measured using the pulse-echo method. A liquid film sensor based on the electrical conductance method is also used for results comparison. The most frequently observed thickness measured by the two methods is almost the same based on comparison of the measurement histograms. To estimate the resolution of the pulse-echo method, the pulse intensities of multiple reflections in the liquid film are simulated. The results show that a liquid film thickness of 0.03mm can be measured even if the ultrasonic frequency is less than 5MHz. (author)

  3. Measurement of Mucosal Thickness in Denture-bearing Area of Edentulous Mandible

    Directory of Open Access Journals (Sweden)

    Jian Dong

    2015-01-01

    Full Text Available Background: The thickness of the alveolar mucosa influences the probability of the occurrence of denture-induced irritations. Thick denture-supporting tissues offer relief from mucosal tenderness and ulcers; however, the uniformity of the thickness across the entire mandibular alveolar mucosa cannot be accurately determined in edentulous patients. This study aimed to assess the mucosal thickness of the denture-bearing area in the edentulous mandible. Methods: Twenty-seven edentulous patients underwent cone-beam computed tomography scanning, wherein the patients wore a record base to retract soft tissues away from the alveolar mucosa. The measured regions were the central incisor (IC, lateral incisor (IL, canine (Ca, first premolar (P1, second premolar (P2, first molar (M1, and second molar (M2 regions. The thickness was measured in the alveolar ridge crest (T, buccal (B1-B4, and lingual (L1-L4 alveolar ridge mucosa. The average thickness of the mucosa at buccal sides (B and lingual sides (L were also assessed. Results: The differences in the mucosal thickness between the left and right sides were not significant. In the Ca-M2 regions, T was the thickest, and L3 was the thinnest of all the measured points in the same regions. L was significantly less than B in posterior regions (P < 0.01. On the other hand, M2 at L4 was thinnest of all the measured regions from Ca to M2 (P < 0.01, and was thicker than IC, IL, P1, and P2 at B2. Conclusions: Since the mucosal thickness of denture-bearing area in the edentulous mandible is not uniform; the tissue surface of the denture base or custom tray should be selectively relieved, which may reduce the risk of denture-induced irritations.

  4. Measurement of Mucosal Thickness in Denture-bearing Area of Edentulous Mandible

    Institute of Scientific and Technical Information of China (English)

    Jian Dong; Fei-Yu Zhang; Guang-Hui Wu; Wei Zhang; Jian Yin

    2015-01-01

    Background:The thickness of the alveolar mucosa influences the probability of the occurrence of denture-induced irritations.Thick denture-supporting tissues offer relief from mucosal tenderness and ulcers; however,the uniformity of the thickness across the entire mandibular alveolar mucosa cannot be accurately determined in edentulous patients.This study aimed to assess the mucosal thickness of the denture-bearing area in the edentulous mandible.Methods:Twenty-seven edentulous patients underwent cone-beam computed tomography scanning,wherein the patients wore a record base to retract soft tissues away from the alveolar mucosa.The measured regions were the central incisor (IC),lateral incisor (IL),canine (Ca),first premolar (P 1),second premolar (P2),first molar (M1),and second molar (M2) regions.The thickness was measured in the alveolar ridge crest (T),buccal (B 1-B4),and lingual (L1-L4) alveolar ridge mucosa.The average thickness of the mucosa at buccal sides (B) and lingual sides (L) were also assessed.Results:The differences in the mucosal thickness between the left and right sides were not significant.In the Ca-M2 regions,T was the thickest,and L3 was the thinnest of all the measured points in the same regions.L was significantly less than B in posterior regions (P < 0.01).On the other hand,M2 at L4 was thinnest of all the measured regions from Ca to M2 (P < 0.01),and was thicker than IC,IL,P1,and P2 at B2.Conclusions:Since the mucosal thickness of denture-bearing area in the edentulous mandible is not uniform; the tissue surface of the denture base or custom tray should be selectively relieved,which may reduce the risk of denture-induced irritations.

  5. Operating limits for acoustic measurement of rolling bearing oil film thickness

    OpenAIRE

    Dwyer-Joyce, R.S.; Reddyhoff, T.; Drinkwater, B.

    2004-01-01

    An ultrasonic pulse striking a thin layer of liquid trapped between solid bodies will be partially reflected. The proportion reflected is a function of the layer stiffness, which in turn depends on the film thickness and its bulk modulus. In this work, measurements of reflection have been used to determine the thickness of oil films in elastohydrodynamic lubricated (EHL) contacts. A very thin liquid layer behaves like a spring when struck by an ultrasonic pulse. A simple quasi-static spring m...

  6. Operating Limits for Acoustic Measurement of Rolling Bearing Oil Film Thickness

    OpenAIRE

    Dwyer-Joyce, R.S.; Reddyhoff, T.; Drinkwater, B.

    2004-01-01

    An ultrasonic pulse striking a thin layer of liquid trapped between solid bodies will be partially reflected. The proportion reflected is a function of the layer stiffness, which in turn depends on the film thickness and its bulk modulus. In this work, measurements of reflection have been used to determine the thickness of oil films in elastohydrodynamic lubricated (EHL) contacts. A very thin liquid layer behaves like a spring when struck by an ultrasonic pulse. A simple quasi-static spring m...

  7. Infrared Transmissometer to Measure the Thickness of NbN Thin Films

    CERN Document Server

    Sunter, Kristen A; Lang, Christopher I; Berggren, Karl K

    2015-01-01

    We present an optical setup that can be used to characterize the thicknesses of thin NbN films to screen samples for fabrication and to better model the performance of the resulting superconducting nanowire single photon detectors. The infrared transmissometer reported here is easy to use, gives results within minutes and is non-destructive. Thus, the thickness measurement can be easily integrated into the workflow of deposition and characterization. Comparison to a similar visible-wavelength transmissometer is provided.

  8. Measurements of Sr/Ca in bones to evaluate differences in temperature

    Energy Technology Data Exchange (ETDEWEB)

    Santos, P.R. [IFUSP, Travessa R da rua do Matao 187, Cidade Universitaria, CEP 05508-970, Sao Paulo, SP (Brazil); Added, N. [IFUSP, Travessa R da rua do Matao 187, Cidade Universitaria, CEP 05508-970, Sao Paulo, SP (Brazil)], E-mail: nemitala@dfn.if.usp.br; Aburaya, J.H.; Rizzutto, M.A. [IFUSP, Travessa R da rua do Matao 187, Cidade Universitaria, CEP 05508-970, Sao Paulo, SP (Brazil)

    2008-04-15

    Analysis of aragonite from sea shells and coral skeletons showed a clear correlation between the strontium and calcium concentrations for these crystals (Sr/Ca ratio) and seawater temperature obtained by satellites and ship readings. In this work we present the results of a study that correlates Sr/Ca ratio with formation temperature of another calcium crystal, the hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}), main mineral compound of teeth and bones from vertebrates. These animals, independent of its thermoregulation pattern (endothermic or ectothermic) have variations of internal temperature along the body. One interesting application of this work is to differentiate warm-blooded animals from cold-blooded ones just by measuring Sr/Ca ratio in their bones. Bones from a crocodile from Caiman yacare species and two dogs, a poodle and a non defined race, were analyzed using PIXE technique and thick target correction. A 1.78 (18) MeV external proton beam was used in LAMFI-USP with an accumulated charge of about 10 {mu}C for probing the samples. Emitted X-rays were collected using Si-PIN detectors (140 keV for Fe). As in coral skeletons, the Sr/Ca ratio of animals is lower in the body's warmer parts and higher in colder parts.

  9. Measurements of Sr/Ca in bones to evaluate differences in temperature

    International Nuclear Information System (INIS)

    Analysis of aragonite from sea shells and coral skeletons showed a clear correlation between the strontium and calcium concentrations for these crystals (Sr/Ca ratio) and seawater temperature obtained by satellites and ship readings. In this work we present the results of a study that correlates Sr/Ca ratio with formation temperature of another calcium crystal, the hydroxyapatite (Ca10(PO4)6(OH)2), main mineral compound of teeth and bones from vertebrates. These animals, independent of its thermoregulation pattern (endothermic or ectothermic) have variations of internal temperature along the body. One interesting application of this work is to differentiate warm-blooded animals from cold-blooded ones just by measuring Sr/Ca ratio in their bones. Bones from a crocodile from Caiman yacare species and two dogs, a poodle and a non defined race, were analyzed using PIXE technique and thick target correction. A 1.78 (18) MeV external proton beam was used in LAMFI-USP with an accumulated charge of about 10 μC for probing the samples. Emitted X-rays were collected using Si-PIN detectors (140 keV for Fe). As in coral skeletons, the Sr/Ca ratio of animals is lower in the body's warmer parts and higher in colder parts

  10. Thickness distribution of adolescent palatal bone studied by CBCT%青少年腭部骨质厚度的 CBCT 研究

    Institute of Scientific and Technical Information of China (English)

    陈建明; 苏小元

    2014-01-01

    目的:研究青少年腭部骨质厚度分布,为腭部植入微种植体提供参考。方法:用 NNT Viewer 软件将20例青少年正畸患者的头颅锥形束 CT 扫描数据的腭部情况进行分析,以切牙孔为原点,间隔2 mm,矢状方向分为1~10共10个点,横向分为 A ~F 共6个点,测量统计60个点位的骨厚度,并行统计学分析。结果:B2、B3、C2、C3、D3、E3、E4、F4、F5各点间差异无统计学意义(P >0.05);而 F3点与 B2、B3、C2、C3、D3、E3、E4、F4、F5各点间的差异具有统计学意义(P <0.05);D3与 D4间差异具有统计学意义(P <0.05)。结论:适于微种植体植入的部位在腭中缝左右2~4 mm、离切牙孔4~6 mm 区域,而距腭中缝8~10 mm、离切牙孔6~8 mm 区域较为安全,同时可获得厚度为6 mm 左右的骨组织支持。%Objective:To study the thickness distribution palatal bone in adolescents and provide a clinical reference for implanting mini-screws.Methods:Cone-beam CT head scan data of palate of 20 adolescent orthodontic patients were measured with NNT Viewer software.60 points of the palate bone on one side were designed as 1 -10 in sagittal direction and as A -F in transvers direction with incisive foramen as the point of A and 0,the distance between each 2 adjacent points was 2 mm.The bone thickness of the 60 points were measured and statistically analyzed.Results:There were no significant differences among B2,B3,C2,C3,D3,E3,E4,F4 and F5(P >0.05).Statistically significant difference was found between F3 and B2 or B3,C2,C3,D3,E3,E4,F4 and F5(P <0.05).There was significant difference between D3 and D4(P <0.05).Conclusion:The appropriate areas for implanting mini-screws in palate may be about 2 -4 mm near the palatal suture and 4 -6 mm behind incisor canal,and 8 -10 mm near the palatal su-ture,6 -8 mm behind incisor canal.Those regions are safe for implanting mini-screws and can provide about 6 mm bone

  11. Non-contact thickness measurement for ultra-thin metal foils with differential white light interferometry

    Institute of Scientific and Technical Information of China (English)

    Yanli Du(杜艳丽); Huimin Yan(严惠民); Yong Wu(吴勇); Xiaoqiang Yao(姚晓强); Yongjun Nie(聂永军); Baixuan Shi(施柏煊)

    2004-01-01

    A new differential white light interference technique for the thickness measurements of metal foil is presented. In this work, the differential white light system consists of two Michelson interferometers in tandem,and the measured reflective surfaces are the corresponding surfaces of metal foil. Therefore, the measuring result is only relative to the thickness but not the position of metal foil. The method is non-contact and non-destructive, it has the advantages of high accuracy, fast detection, and compact structure. Theoretical analysis and preliminary experimental verifications have shown that the technique can be used to measure the thickness of foil in the range of 1 to 80 μm with accuracy better than 0.08 μm.

  12. Optimization of Condition of Ultrasonic Beam for Measurement of Small Change in Thickness of Arterial Wall

    Science.gov (United States)

    Watanabe, Masaru; Hasegawa, Hideyuki; Kanai, Hiroshi

    2002-05-01

    We previously developed a method for measuring small changes in thickness of the arterial wall during one cardiac cycle. Knowledge of this change in thickness is useful for in vivo assessment of the regional elasticity of the arterial wall. In this study, from computer simulations, it is found that measurement error depends on the distance of the ultrasonic beam from the center of the artery and it can be reduced by optimally setting the focal position. In basic experiments using a silicone rubber tube and in in vivo experiments with a human carotid artery, it is found that by optimizing the focal position, measurement of the change in thickness becomes more robust against mispositioning of the ultrasonic beam. From these results, it is demonstrated that optimum focal positioning provides more robustness in measurement, even if there is arterial wall motion causing the position of the ultrasonic beam to deviate from the center of the artery.

  13. A Study on the Determination of Concrete Thickness and Effective Measurement Area using Radar

    Energy Technology Data Exchange (ETDEWEB)

    Rhim, Hong Chul; Lee, Ji Hoon; Son, Byung Oh [Yonsei University, Seoul (Korea, Republic of)

    2000-08-15

    Radar is becoming a popular tool for condition assessment of concrete structures. The advancement of radar method to concrete structures requires a systematic approach, which incorporates the fundamentals of radar theory and the characteristics of concrete as a material with electromagnetic properties. The research work presented in this paper deals with the establishment of effective measurement area for radar measurements, the determination of concrete thickness using radar, and the calculation of the dielectric constant of concrete from radar measurements. As results, formulas have been suggested to determine optimum measurement area for concrete, using radar and concrete thickness has been successfully identified for specimens used in this work. In the experiments, five concrete specimens which have the dimensions of 900mm (length) x 600mm (width) with thickness variation from 50mm to 250mm are used

  14. Corrective Change of Retinal Thickness Measured by Optical Coherence Tomography and Histologic Studies

    Institute of Scientific and Technical Information of China (English)

    GeJ; LuoRJ

    1999-01-01

    Purpose:To evaluate the correlation of retinal thickness between optical coherence tomography(OCT)images and histologic slides.Methods:Retinal thickness was measured in 16 rabbit retinal histologic slides.The same eyes has been previously measured by OCT fr the comparison of results between two methods.Retinal thickness of each OCT image section was measured using both the manually assisted(requiring localization of reflectivity peaks by observer)and automated modes of the computer software.Results:Retinal thickness measured by OCT demonstrated a high degree of correlation with retinal histologic study.The automated method(Cc=0.66,P<0.01) was less reliable than the manually assisted one (Cc=0.84,P<0.001).The former had an error in 95% confidence interval,ranged between-0.71 and 11.09μm.The latter had a less error,ranged from -2.99 to 5.13μm.Conclusion:OCT can quantitatively measure the retinal thickness.However,automatical identification of the reflective boundaries by computer may result in errors in some cases.To masure the retinal thickess by manually assisted mode can increase the accuracy.

  15. Bone mineral density measurement over the shoulder region

    DEFF Research Database (Denmark)

    Doetsch, A M; Faber, J; Lynnerup, N; Wätjen, I; Bliddal, H; Danneskiold-Samsøe, B

    2002-01-01

    The purpose of this study was to (1). establish a method for measuring bone mineral density (BMD) over the shoulder region; (2). compare the relationship between shoulder BMD levels with hip BMD and body mass index (BMI); and (3). discuss the relevance of the shoulder scan as an early indicator of...... osteoporosis compared with hip scans, the latter representing a weight-bearing part of the skeleton. We developed a scanning procedure, including a shoulder fixation device, and determined the most appropriate software in order to establish a reference material with the highest possible precision. Duplicate...

  16. Measurement of the thickness of paint coat on concrete by β-reflection method

    International Nuclear Information System (INIS)

    The measurement of the thickness of paint coating on concrete by isotope method is discussed. The influence of pigment in paints and lacquers on the measurement results is considered. The review of pigments used in paints and lacquers is presented. Pigments atomic numbers are also given. (A.S.)

  17. Ultrasonic measurement of enamel thickness : a tool for monitoring dental erosion?

    NARCIS (Netherlands)

    Huysmans, MCDNJM; Thijssen, JM

    2000-01-01

    Objectives: Wear of dental hard tissues, e.g. dental erosion, is reported to be a growing problem. A non-destructive measurement of enamel layer thickness would provide the opportunity for both early diagnosis, and longitudinal measurement of progressive enamel loss. It was the aim of this study to

  18. Manual B-Mode Versus Automated Radio-Frequency Carotid Intima-Media Thickness Measurements

    NARCIS (Netherlands)

    S. Dogan; Y. Plantinga; J.M. Dijk; Y. van der Graaf; D.E. Grobbee; M.L. Bots

    2009-01-01

    Background: Carotid intima-media thickness (CIMT) serves as an indicator of atherosclerosis and cardiovascular risk. Manual measurements of B-mode ultrasound images are the most applied method. Automated measurements with radiofrequency (RF) ultrasound have been suggested as an alternative. The aim

  19. Sea ice thickness measurement in spring season in Bothnian Bay using an electromagnetic induction instrument

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As an important component of the cryosphere, sea ice is very sensitive to the climate change. The study of the sea ice physics needs accurate sea ice thickness. This paper presents an electromagnetic-induction (EM) technique which can be used to measure the sea ice thickness distribution efficiently, and the successful application in Bothnian Bay. Based on the electromagnetic field theory and the electrical properties of sea ice and seawater,EM technique can detect the distance between the instrument and the ice/water interface accurately, than the sea ice thickness is obtained. Contrastive analysis of the apparent conductivity data obtained by EM and the value of drill-hole at same positions allows a construction of a transformable formula of the apparent conductivity to sea ice thickness. The verification of the sea ice thickness calculated by this formula indicates that EM technique is able to get reliable sea ice thickness with average relative error of only 12%. The statistic of all ice thickness profiles shows that the level ice distribution in Bothnian Bay was 0.4 - 0.6 m.

  20. Measured and predicted residual stresses in thick section electron beam welded steels

    International Nuclear Information System (INIS)

    Four steel thick-section components, created by electron beam (EB) welding, were measured to obtain their residual stress distributions. Two components were made from ferritic steel and two components manufactured from stainless steel. All four components were measured in the as-welded state, with one ferritic steel component then subjected to post-weld heat treatment (PWHT) and measured. Distributions of the principal residual stresses were measured, across the EB welds and through the weld centrelines. Finite element models simulated the welding processes and the predicted residual stresses were compared to the measurements. In the ferritic steel components it was found that the peak residual stresses occur either side of the weld outside of the heat affected zone, with magnitudes corresponding to parent material yield strengths. After PWHT the measured peak stresses reduced from about 600 MPa to 90 MPa. Compressive residual stresses were found at the EB weld entrance and exit positions of the ferritic steel. This was not observed in the stainless steel EB welds, where tensile stresses were measured in the as-welded state. Overall the profiles of the residual stresses predicted by FE analyses replicated the measurements, but the FE analyses always predicted higher peak values. It was found that the measured distribution of residual stresses across the ferritic steel components are very similar irrespective of component thickness and weld speed, with the tensile stresses confined to distances of about 40% of the component thickness. In contrast in a stainless steel component the tensile stresses are much more broadly distributed about the weld centreline. - Highlights: • Electron beam welding thick section steel plates and cylinders were created. • Through thickness residual stress distributions were measured and predicted. • There is reasonable agreement between measurement and prediction but not in all cases. • Significant differences in stresses occur

  1. Non-invasive measurement of bone: a review of clinical and research applications in the horse

    International Nuclear Information System (INIS)

    The current methods for non-invasive measurement of bone quality are reviewed. In the horse this has traditionally involved the use of radiography, but there are now two other modalities available for the critical evaluation of cortical bone quality and strength. These utilise single photon absorptiometry and ultrasound velocity. Photon absorptiometry gives a direct measurement of bone mineral content, by using a monoenergetic radionuclide source, and transverse ultrasound velocity in bone gives a measure of bone stiffness or elasticity. They can both be used conveniently on the metacarpus of the conscious horse. Both ultrasound velocity and bone mineral content can be used as accurate indicators of skeletal maturity. In addition, the effects of disuse on bone and certain types of lameness can be monitored accurately. Preliminary data show an association with exercise in young and mature horses. There also appears to be considerable scope for in vivo research of bone changes in horses produced by immobilisation, weightlessness, exercise and nutrition

  2. A new measurement method of coatings thickness based on lock-in thermography

    Science.gov (United States)

    Zhang, Jin-Yu; Meng, Xiang-bin; Ma, Yong-chao

    2016-05-01

    Coatings have been widely used in modern industry and it plays an important role. Coatings thickness is directly related to the performance of the functional coatings, therefore, rapid and accurate coatings thickness inspection has great significance. Existing coatings thickness measurement method is difficult to achieve fast and accurate on-site non-destructive coatings inspection due to cost, accuracy, destruction during inspection and other reasons. This paper starts from the introduction of the principle of lock-in thermography, and then performs an in-depth study on the application of lock-in thermography in coatings inspection through numerical modeling and analysis. The numerical analysis helps explore the relationship between coatings thickness and phase, and the relationship lays the foundation for accurate calculation of coatings thickness. The author sets up a lock-in thermography inspection system and uses thermal barrier coatings specimens to conduct an experiment. The specimen coatings thickness is measured and calibrated to verify the quantitative inspection. Experiment results show that the lock-in thermography method can perform fast coatings inspection and the inspection accuracy is about 95%. Therefore, the method can meet the field testing requirements for engineering projects.

  3. Retinal nerve fibre layer thickness measurements in normal Indian population by optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Ramakrishnan R

    2006-01-01

    Full Text Available Purpose: To obtain retinal nerve fibre layer thickness measurements by optical coherence tomography (OCT in normal Indian population. Materials and Methods: Total of 118 randomly selected eyes of 118 normal Indian subjects of both sex and various age groups underwent retinal nerve fiber layer thickness analysis by Stratus OCT 3000 V 4.0.1. The results were evaluated and compared to determine the normal retinal nerve fiber layer thickness measurements and its variations with sex and age. Results: Mean + standard deviation retinal nerve fiber layer thickness for various quadrants of superior, inferior, nasal, temporal, and along the entire circumference around the optic nerve head were 138.2 + 21.74, 129.1 + 25.67, 85.71 + 21, 66.38 + 17.37, and 104.8 + 38.81 µm, respectively. There was no significant difference in the measurements between males and females, and no significant correlation with respect to age. Conclusion: Our results provide the normal retinal nerve fiber layer thickness measurements and its variations with age and sex in Indian population.

  4. [Investigation of Region of Interest (ROI) for measurement of slice thickness in Computed Tomography (CT)].

    Science.gov (United States)

    Nakamura, Shinobu; Kawata, Hidemichi; Nanbu, Ryosuke; Ohkura, Sunao; Hayashida, Kazuya; Hayabuchi, Naofumi

    2010-03-20

    We evaluated an appropriate region of interest (ROI) size for the measurement of full width at half maximum (FWHM) in the bead method (0.1 mm and 0.5 mm diameter; lead) and the microdisk method (0.05 mm thickness and 1.0 mm diameter; tungsten) using multislice computed tomography (CT). The FWHM of preset slice thicknesses 0.625 mm, 1.25 mm, 5.0 mm and 7.5 mm were measured by varying helical pitch, location of measurement [center and off-center of scan field of view (SFOV)] and ROI size, and they were compared with the tolerance stated in the Japanese Industrial Standards (JIS). It was conlcuded that the appropriate ROI size was influenced by preset slice thickness in this study. At the center of SFOV, measurements of FWHM were enabled within the tolerance of the JIS with small variations in all preset slice thicknesses if the ROI sizes were set between 0.4 times and equal to the size of the bead or microdisk indicating the maximum CT value in the series of CT images. At the off-center of SFOV, the tendency of increasing FWHM was confirmed, but it was shown that variations of the off-center in thicker slice thickness were larger regardless of helical pitch when the orbital synchronized helical scan technique was not used. PMID:20379062

  5. Oxide thickness measurement technique for duplex-layer Zircaloy-4 cladding

    Energy Technology Data Exchange (ETDEWEB)

    McClelland, R.G.; O' Leary, P.M. (Siemens Nuclear Power Corp., Richland, WA (United States))

    1992-01-01

    Siemens Nuclear Power Corporation (SNP) is investigating the use of duplex-layer Zircaloy-4 tubing to improve the waterside corrosion resistance of cladding for high-burnup pressurized water reactor (PWR) fuel designs. Standard SNP PWR cladding is typically 0.762-mm (0.030-in.)-thick Zircaloy-4. The SNP duplex cladding is nominally 0.660-mm (0.026-in.)-thick Zircalloy-4 with an [approximately]0.102-mm (0.004-in.) outer layer of another, more corrosion-resistant, zirconium-based alloy. It is common industry practice to monitor the in-reactor corrosion behavior of Zircaloy cladding by using an eddy-current lift-off' technique to measure the oxide thickness on the outer surface of the fuel cladding. The test program evaluated three different cladding samples, all with the same outer diameter and wall thickness: Zircaloy-4 and duplex clad types D2 and D4.

  6. On-Line Measurement of Lubricant Film Thickness Using Ultrasonic Reflection Coefficients

    International Nuclear Information System (INIS)

    The ultrasonic reflectivity of a lubricant layer between two solid bodies depends on the ultrasonic frequency, the acoustic properties of the liquid and solid, and the layer thickness. In this paper, ultrasonic reflectivity measurements are used as a method for determining the thickness of lubricating films in bearing systems. An ultrasonic transducer is positioned on the outside of a bearing shell such that the wave is focused on the lubricant film layer. For a particular lubricant film the reflected pulse is processed to give a reflection coefficient spectrum. The lubricant film thickness is then obtained from either the layer stiffness or the resonant frequency. The method has been validated using static fluid wedges and the elastohydrodynamic film formed between a ball sliding on a flat. Film thickness values in the range 50-500 nm were recorded which agreed well with theoretical film formation predictions

  7. Tundish Cover Flux Thickness Measurement Method and Instrumentation Based on Computer Vision in Continuous Casting Tundish

    Directory of Open Access Journals (Sweden)

    Meng Lu

    2013-01-01

    Full Text Available Thickness of tundish cover flux (TCF plays an important role in continuous casting (CC steelmaking process. Traditional measurement method of TCF thickness is single/double wire methods, which have several problems such as personal security, easily affected by operators, and poor repeatability. To solve all these problems, in this paper, we specifically designed and built an instrumentation and presented a novel method to measure the TCF thickness. The instrumentation was composed of a measurement bar, a mechanical device, a high-definition industrial camera, a Siemens S7-200 programmable logic controller (PLC, and a computer. Our measurement method was based on the computer vision algorithms, including image denoising method, monocular range measurement method, scale invariant feature transform (SIFT, and image gray gradient detection method. Using the present instrumentation and method, images in the CC tundish can be collected by camera and transferred to computer to do imaging processing. Experiments showed that our instrumentation and method worked well at scene of steel plants, can accurately measure the thickness of TCF, and overcome the disadvantages of traditional measurement methods, or even replace the traditional ones.

  8. CT measurement of normal pericardial thickness in adults on computed tomography

    International Nuclear Information System (INIS)

    The purpose of this study was to establish, using computed tomography, the normal thickness of the pericardium in adults. Materials and Methods: CT scans of 50 patients, including sections through the level of the heart, were reviewed. Patients were excluded if there were any suspicions of pericardial abnormality such as infectious or neoplastic diseases. Twenty-four of the 50 were men and 26 were women; their mean age was 47.0(range,18-76) years. We measured pericardial thickness at the level of the right ventricle, interventricular septum and left ventricle, and also compared pericardial thickness in terms of age and sex. Results: In all patients, the pericardium was observed in the right ventricular region; in 41 (82%) at the interventricular septum; and in 41 (82%) along the left ventricle. The mean thickness of normal pericardium at the level of the right ventricle, interventricular septum, and left ventricle was 1.8 mm ± 0.5 mm, 1.8 mm ± 0.4 mm, and 1.7 mm ± 0.5 mm, respectively. No statistically significant correlation was apparent between pericardial thickness and age group (p > 0.63, ANOVA test). Mean pericardial thickness was 1.9 mm ± 0.6 mm in males and 1.7 mm ± 0.4 mm in females; thus, no statistically significant correlation was apparent between pericardial thickness and sex (p >0.29, Student's t-test). Conclusion: The pericardium was best visualized in sections through the right ventricle.The mean thickness of normal pericardium was 1.8 mm ± 0.5 mm and pericardial thickness did not differ according to age or sex

  9. Measurement of infinitesimal delamination thickness by using echo amplitude of ultrasonic wave

    International Nuclear Information System (INIS)

    If the infinitesimal delamination exists and the two waves can hardly be distinguish from each other on account of being much closer, we cannot measure the infinitesimal delamination thickness by the time difference method. On this study, we calculated the thickness of infinitesimal delamination model by means of measuring echo height according to the deflection of material particles and utilized Newton Ring for optical measurement as a delamination model From the result of Newton Ring expressed in the delamination model, we could calculate the infinitesimal delamination thickness up to 0.2 - 0.3μm according to the difference of acoustic impedance by the rate of echo height related to the total reflection.

  10. Non-contact wafer thickness measurement of capacitance sensor circuit based on CAV424

    Directory of Open Access Journals (Sweden)

    Yan You Jun

    2016-01-01

    Full Text Available Non-contact wafer thickness measurement with the CAV424 capacitance sensor special integrated circuit and arc pole plate capacitor sensor has good stability and linearity under low capacity of the bottom of sensor and low&entity; C condition. This method has a high technical advantages and practical value. Two capacitance sensors Cb, Ca measurement spacing 4mm install at the same axis which constitutes the size condition for measuring thickness. The static capacity of Ca and Cb is a constant value. The capacity of Cb and Ca will change when the silicon wafer is involved. This change is checked by the CAV424 capacitive sensor which has better linearity and higher thickness resolution.

  11. Measurement of Infinitesimal Delaminaton Thickness by Echo Amplitude of Ultrasonic Wave

    International Nuclear Information System (INIS)

    If the infinitesimal delamination exists and the two waves can hardly be distinguished from each other on account of being much closer, we cannot measure the thickness of delamination by the time difference method. On this study, we calculated the thickness of infinitesimal delamination model by means of measuring echo height due to the deflection of material particles and utilized Newton Ring for optical measurement as a delamination model. From the result of Newton Ring expressed in the delamination model, we can calculate the infinitesimal delamination thickness up to 0.2∼0.3μm due to the difference of acoustic impedance by the ratio of the echo height to the total reflection

  12. Role of experimental resolution in measurements of critical layer thickness for strained-layer epitaxy

    International Nuclear Information System (INIS)

    Experimental measurements of critical layer thicknesses (CLT's) in strained-layer epitaxy are considered. Finite experimental resolution can have a major effect on measured CLT's and can easily lead to spurious results. The theoretical approach to critical layer thicknesses of J. W. Matthews [J. Vac. Sci. Technol. 12, 126 (1975)] has been modified in a straightforward way to predict the apparent critical thickness for an experiment with finite resolution in lattice parameter. The theory has also been modified to account for the general empirical result that fewer misfit dislocations are generated than predicted by equilibrium calculation. The resulting expression is fit to recent x-ray diffraction data on InGaAs/GaAs and SiGe/Si. The results suggest that CLT's in these systems may not be significantly larger than predicted by equilibrium theory, in agreement with high-resolution measurements

  13. DXA measurements in rett syndrome reveal small bones with low bone mass

    DEFF Research Database (Denmark)

    Roende, Gitte; Ravn, Kirstine; Fuglsang, Kathrine;

    2011-01-01

    Low bone mass is reported in growth-retarded patients harboring mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene causing Rett syndrome (RTT). We present the first study addressing both bone mineral density (BMD) and bone size in RTT. Our object was to determine whether patients...

  14. Measurement of changes in water thickness in plant materials using very low-energy neutron radiography

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, U. [University of the Ryukyus, Nishihara, Okinawa 903-0213 (Japan)]. E-mail: Uzuki-m@agr.u-ryukyu.ac.jp; Kawabata, Y. [Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan); Hino, M. [Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan); Geltenbort, P. [Institut Laue Langevin, 6, rue Jules Horowitz, BP 156, 38042, Grenoble Cedex 9 (France); Nicolai, B.M. [Katholieke Universiteit Leuven, W De Croylaan, B3001 Heverlee (Belgium)

    2005-04-21

    Low-energy neutron radiographic images of Hedera leaves were obtained using the very cold neutron (VCN) beam at Institut Laue-Langevin, France. A change in hydrogen concentration measured in a short period by means of neutron radiography indicates a change in water concentration in the plant. A regression model was evaluated to estimate changes in water thickness of the leaves and, the resolution of this method was smaller than 5 {mu}m. The method was effective to measure small changes in water thickness of thin plant leaves.

  15. Measurement of changes in water thickness in plant materials using very low-energy neutron radiography

    Science.gov (United States)

    Matsushima, U.; Kawabata, Y.; Hino, M.; Geltenbort, P.; Nicolaï, B. M.

    2005-04-01

    Low-energy neutron radiographic images of Hedera leaves were obtained using the very cold neutron (VCN) beam at Institut Laue-Langevin, France. A change in hydrogen concentration measured in a short period by means of neutron radiography indicates a change in water concentration in the plant. A regression model was evaluated to estimate changes in water thickness of the leaves and, the resolution of this method was smaller than 5 μm. The method was effective to measure small changes in water thickness of thin plant leaves.

  16. Development of ultrasonic heat transfer tube thickness measurement apparatus. Contract research

    International Nuclear Information System (INIS)

    The demonstration test for evaluating reliability of the acid recovery evaporator at Rokkasho Reprocessing Plant has been carried out at JAERI. For the nondestructive measurement of the thickness of heat transfer tubes of the acid recovery evaporator in corrosion test, we have developed thickness measurement apparatus for heat transfer tubes by ultrasonic immersion method with high resolution. The ultrasonic prove in a heat transfer tube can be moved vertically and radially. The results obtained by this apparatus coincident well with those obtained by a destructive method using an optical microscope. (author)

  17. Wavelength Sweep Interferometry for Measuring the Refractive Index and Physical Thickness

    Institute of Scientific and Technical Information of China (English)

    SONG Guiju; WANG Xiangzhao; FANG Zujie

    2001-01-01

    A method combining wavelength sweep interferometry with the Fourior transform technique to perform the separate measurements of the physical thickness and the refractive index is proposed. By converting the optical path difference of the interferometer to the beat frequency of the interference signal we realize the depth scanning without mechanical moving parts. The effect of specimen dispersion is avoided by using a narrow tuning laser diode. For demonstrating this method we measure the physical thickness and the refractive index of an x-cut LiNbO3, BK9 and BK7 glass, and the results consist with the reported values.

  18. Uncertainty in stratiform cloud optical thickness inferred from pyranometer measurements at the sea surface

    Directory of Open Access Journals (Sweden)

    Anna Rozwadowska

    2004-06-01

    Full Text Available The relative "plane-parallel" error in a mean cloud optical thickness retrieved from ground-based pyranometer measurements is estimated. The plane-parallel error is defined as the bias introduced by the assumption in the radiative transfer model used in cloud optical thickness retrievals that the atmosphere, including clouds, is horizontally homogeneous on the scale of an individual retrieval. The error is estimated for the optical thickness averaged over the whole domain, which simulates the mean cloud optical thickness obtained from a time series of irradiance measurements. The study is based on 3D Monte Carlo radiative transfer simulations for non-absorbing, all-liquid, layer clouds. Liquid water path distributions in the clouds are simulated by a bounded cascade fractal model. The sensitivity of the error is studied with respect to the following factors: averaging time of irradiance used in an individual retrieval, mean cloud optical thickness, cloud variability, cloud base height and solar zenith angle. In the simulations presented in this paper, the relative bias in the domain averaged cloud optical thickness retrieved from pyranometer measurements varies from +1% for optically thin clouds to nearly -20%. The highest absolute value of the relative bias is expected for thick and variable clouds with high bases (e.g. 1 km and retrievals based on long-term mean irradiances (averaging time of the order of several tens of minutes or hours. The bias can be diminished by using short-term irradiance averages, e.g. of one minute, and by limiting retrievals to low-level clouds.

  19. Comparison of Central Corneal Thickness Measurements Obtained with Ultrasonic Pachymetry and Spectral Domain Anterior Segment OCT

    OpenAIRE

    Kirikkaya, Esin Tunca; Akyuz Unsal, Ayşe İpek; Dogramaci, Mahmut

    2014-01-01

    Aim: To compare central corneal thickness (CCT) measurements obtained with Ultrasonic Pachymetry (USP) and Anterior Segment Optical Coherence Tomography (AS-OCT).Methods: Seventy eight eyes of thirty nine volunteers between 40-60 ages were recruited in this study. Best corrected visual acuity (BCVA), intraocular pressure (IOP) measurements, anterior and posterior segment biomicroscopic examinations of all volunteers were performed. CCT measurements were evaluated with Nidek  UP and Zeiss Cirr...

  20. Modelling the normal retinal nerve fibre layer thickness as measured by Stratus optical coherence tomography.

    OpenAIRE

    Hougaard, Jesper; Ostenfeld, Carl; Heijl, Anders; Bengtsson, Boel

    2006-01-01

    Background: The variation in retinal nerve fibre layer thickness (RNFLT) as measured by Stratus optical coherence tomography (OCT) in healthy subjects may be reduced when the effect on RNFLT measurements of factors other than disease is corrected for, and this may improve the diagnostic accuracy in glaucoma. With this perspective we evaluated the isolated and combined effects of factors potentially affecting the Stratus OCT RNFLT measurements in healthy subjects. Methods: We included 178 heal...

  1. Manual versus automatic bladder wall thickness measurements: a method comparison study

    OpenAIRE

    Oelke, M.; Mamoulakis, C; Ubbink, D T; Rosette, de la, J.J.M.C.H.; Wijkstra, H.

    2009-01-01

    Purpose To compare repeatability and agreement of conventional ultrasound bladder wall thickness (BWT) measurements with automatically obtained BWT measurements by the BVM 6500 device. Methods Adult patients with lower urinary tract symptoms, urinary incontinence, or postvoid residual urine were urodynamically assessed. During two subsequent cystometry sessions the infusion pump was temporarily stopped at 150 and 250 ml bladder filling to measure BWT with conventional ultrasound and the BVM 6...

  2. Thin-film thickness profile measurement using a Mirau-type low-coherence interferometer

    International Nuclear Information System (INIS)

    White-light interferometry has been spotlighted for years in the field of microelectronics as a 3D profiling tool but its application was limited to only opaque surfaces. Recently many approaches using white-light extended sources have been performed to measure the top and bottom surfaces of a thin-film structure simultaneously. When the film thickness is less than the coherence length of the light source, two waves reflected from the top and bottom surfaces of the film overlap and the interference signal become more complicated than for an opaque surface. Thus, it is an essential issue to cleanly separate the film thickness and surface height information from the complex interferograms. In this paper, we describe a Mirau-type low-coherence interferometer for measurements of the film thickness and top surface height profile with a simple measurement procedure. Our proposed method is verified by simulating the measurement errors according to the film thickness and measuring a SiO2 patterned film structure. (paper)

  3. Real-time dielectric-film thickness measurement system for plasma processing chamber wall monitoring.

    Science.gov (United States)

    Kim, Jin-Yong; Chung, Chin-Wook

    2015-12-01

    An in-situ real-time processing chamber wall monitoring system was developed. In order to measure the thickness of the dielectric film, two frequencies of small sinusoidal voltage (∼1 V) signals were applied to an electrically floated planar type probe, which is positioned at chamber wall surface, and the amplitudes of the currents and the phase differences between the voltage and current were measured. By using an equivalent sheath circuit model including a sheath capacitance, the dielectric thickness can be obtained. Experiments were performed in various plasma condition, and reliable dielectric film thickness was obtained regardless of the plasma properties. In addition, availability in commercial chamber for plasma enhanced chemical vapor deposition was verified. This study is expected to contribute to the control of etching and deposition processes and optimization of periodic maintenance in semiconductor manufacturing process. PMID:26724022

  4. Simultaneous measurement of sound velocity and wall thickness of a tube.

    Science.gov (United States)

    He, P

    2001-10-01

    A method for simultaneously measuring the sound propagation velocity and the thickness of each wall on the opposite sides of a tube is presented. The method uses a pair of ultrasound transducers to produce two reflected pulses from the outer and inner surfaces of the tube wall on the each side, and two transmitted pulses, one with and one without the tube sample between the two transducers. Using the time-domain analysis, sound velocity and wall thickness of the tube are determined from the time delays between the three pairs of ultrasound pulses, whereas using the frequency-domain analysis, phase velocity, group velocity, and wall thickness of the tube are determined from the phase differences between the three pairs of ultrasound pulses. Results of measurements on five tube samples are reported. PMID:11775655

  5. Ultrasonic technique for measuring the thickness of scale on the inner surfaces of pipes

    International Nuclear Information System (INIS)

    At the present time, there are no known commercialized nondestructive techniques for measuring or detecting the scale on the inner surfaces of pipes in situ. The present study aims to develop an ultrasonic technique for measuring the thickness of scale on the inner surfaces of pipes in situ. All experiments were carried out under laboratory conditions by using three pipe samples with scale (HNO3). The pipe samples were made of polypropylene (PP), polyvinyl chloride (PVC), and steel, respectively. The ultrasonic technique developed in the present study was successfully applied to determine the scale thicknesses of the PP and the PVC pipes whereas it was not applicable to the steel pipe. It is expected that a predetermined graph for a particular type of scale, relating the scale thickness to the time of flight of a pulse within the scale, can be used in further testing, thereby eliminating the need for future destructive inspections.

  6. Real-time dielectric-film thickness measurement system for plasma processing chamber wall monitoring

    Science.gov (United States)

    Kim, Jin-Yong; Chung, Chin-Wook

    2015-12-01

    An in-situ real-time processing chamber wall monitoring system was developed. In order to measure the thickness of the dielectric film, two frequencies of small sinusoidal voltage (˜1 V) signals were applied to an electrically floated planar type probe, which is positioned at chamber wall surface, and the amplitudes of the currents and the phase differences between the voltage and current were measured. By using an equivalent sheath circuit model including a sheath capacitance, the dielectric thickness can be obtained. Experiments were performed in various plasma condition, and reliable dielectric film thickness was obtained regardless of the plasma properties. In addition, availability in commercial chamber for plasma enhanced chemical vapor deposition was verified. This study is expected to contribute to the control of etching and deposition processes and optimization of periodic maintenance in semiconductor manufacturing process.

  7. IN SITU NON-DESTRUCTIVE MEASUREMENT OF BIOFILM THICKNESS AND TOPOLOGY IN AN INTERFEROMETRIC OPTICAL MICROSCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Larimer, Curtis J.; Suter, Jonathan D.; Bonheyo, George T.; Addleman, Raymond S.

    2016-06-01

    Biofilms are ubiquitous and deleteriously impact a wide range of industrial processes, medical and dental health issues, and environmental problems such as transport of invasive species and the fuel efficiency of ocean going vessels. Biofilms are difficult to characterize when fully hydrated, especially in a non-destructive manner, because of their soft structure and water-like bulk properties. Herein we describe a non-destructive high resolution method of measuring and monitoring the thickness and topology of live biofilms of using white light interferometric optical microscopy. Using this technique, surface morphology, surface roughness, and biofilm thickness can be measured non-destructively and with high resolution as a function of time without disruption of the biofilm activity and processes. The thickness and surface topology of a P. putida biofilm were monitored growing from initial colonization to a mature biofilm. Typical bacterial growth curves were observed. Increase in surface roughness was a leading indicator of biofilm growth.

  8. Image scanning ellipsometry for measuring the transient, film thickness profiles of draining liquids

    International Nuclear Information System (INIS)

    Image Scanning Ellipsometry, a technique to measure the two-dimensional thickness profile of a nonuniform, thin, liquid film, from several nanometers up to tens of microns, in the steady and transient states, was developed and tested. The ability of this full-field imaging technique to map every point on the surface simultaneously was demonstrated by measuring the thickness profiles of very thin, draining, liquid films in the interfacial, transition, hydrodynamic, and capillary regions. Depending on the relative size of the intermolecular, gravitational, and capillary forces, four flow regions were identified. Using a simple model for the transient film thickness profiles of a completely wetting, draining film of FC-70, the experimental results were successfully analyzed in the interfacial, transition, and hydrodynamic regions. A diffusion coefficient for the junction line between the interfacial and transition regions was theoretically and experimentally evaluated

  9. Bone

    International Nuclear Information System (INIS)

    Bone scanning provides information on the extent of primary bone tumors, on possible metastatic disease, on the presence of osteomyelitis prior to observation of roentgenographic changes so that earlier therapy is possible, on the presence of collagen diseases, on the presence of fractures not disclosed by x-ray films, and on the evaluation of aseptic necrosis. However, the total effect and contribution of bone scanning to the diagnosis, treatment, and ultimate prognosis of pediatric skeletal diseases is, as yet, unknown. (auth)

  10. Comparing electron tomography and HRTEM slicing methods as tools to measure the thickness of nanoparticles

    International Nuclear Information System (INIS)

    Nanoparticles' morphology is a key parameter in the understanding of their thermodynamical, optical, magnetic and catalytic properties. In general, nanoparticles, observed in transmission electron microscopy (TEM), are viewed in projection so that the determination of their thickness (along the projection direction) with respect to their projected lateral size is highly questionable. To date, the widely used methods to measure nanoparticles thickness in a transmission electron microscope are to use cross-section images or focal series in high-resolution transmission electron microscopy imaging (HRTEM 'slicing'). In this paper, we compare the focal series method with the electron tomography method to show that both techniques yield similar particle thickness in a range of size from 1 to 5 nm, but the electron tomography method provides better statistics since more particles can be analyzed at one time. For this purpose, we have compared, on the same samples, the nanoparticles thickness measurements obtained from focal series with the ones determined from cross-section profiles of tomograms (tomogram slicing) perpendicular to the plane of the substrate supporting the nanoparticles. The methodology is finally applied to the comparison of CoPt nanoparticles annealed ex situ at two different temperatures to illustrate the accuracy of the techniques in detecting small particle thickness changes.

  11. Measurements of central corneal thickness using two immersion ultrasound techniques and optical technique

    International Nuclear Information System (INIS)

    Objective: To compare the accuracy of central corneal thickness measurements using ultrasound biomicroscopy, Orbscan II tomography and an Artemis-2 very high frequency ultrasound scanner. Methods: The prospective study was conducted at Eye World Centre, Riyadh, Saudi Arabia, from September to November 2012. One eye from each of 60 normal subjects was analysed. The central corneal thickness was measured using ultrasound biomicroscopy, Orbscan II tomography and the Artemis-2 very high frequency ultrasound scanner. Results were compared using analysis of variance, repeated-measures analysis of variance and limits of agreement. Results: The mean central corneal thickness was 530.30+-30.75mm, 548.95+-30.33mm and 554.73+-31.97mm for biomicroscopy, tomography and the scanner respectively. The intraobserver repeatability analyses of variance were not significant for the three procedures (p=0.19, 0.23 and 0.41, respectively). A significant difference was noted among the three different methods (p=0.0001). However, comparison among instruments revealed no significant difference between tomography and the scanner (p>0.05), yet significant differences were noted in biomicroscopy vs tomography, and biomicroscopy vs the scanner (p<0.01 and P < 0.001, respectively). The mean differences (and upper/lower limits of agreement) for central corneal thickness measurements were 18.92+-40.71 (60.90/-98.70); 24.7+-13.13 (1.00/-50.40), and -5.8+-38.61 (69.90/-81.40) for biomicroscopy vs tomography, biomicroscopy vs scanner, and tomography vs scanner respectively. Conclusions: The central corneal thickness measurements obtained using Orbscan II tomography and the Artemis-2 very high frequency ultrasound scanner can be used interchangeably. However, Orbscan II tomography and the Artemis-2 scanner measurements cannot be used interchangeably with ultrasound biomicroscopy. (author)

  12. Aluminum hydroxide coating thickness measurements and brushing tests on K West Basin fuel elements

    International Nuclear Information System (INIS)

    Aluminum hydroxide coating thicknesses were measured on fuel elements stored in aluminum canisters in K West Basin using specially developed eddy current probes . The results were used to estimate coating inventories for MCO fuel,loading. Brushing tests successfully demonstrated the ability to remove the coating if deemed necessary prior to MCO loading

  13. Articular cartilage thickness measured with US is not as easy as it appears

    DEFF Research Database (Denmark)

    Torp-Pedersen, S; Bartels, E M; Wilhjelm, Jens E.;

    2011-01-01

    Theoretically, the high spatial resolution of US makes it well suited to monitor the decrease in articular cartilage thickness in osteoarthritis. A requirement is, however, that the borders of the cartilage are correctly identified and that the cartilage is measured under orthogonal insonation. I...

  14. Thin-film thickness measurement using x-ray peak ratioing in the scanning electron microscope

    International Nuclear Information System (INIS)

    The procedure used to measure laser target film thickness using a scanning electron microscope is summarized. This method is generally applicable to any coating on any substrate as long as the electron energy is sufficient to penetrate the coating and the substrate produces an x-ray signal which can pass back through the coating and be detected

  15. Basic investigation on mandibular cortical thickness measurement in dental panoramic radiographs

    International Nuclear Information System (INIS)

    Mandibular cortical thickness (MCT) on dental panoramic radiographs (DPRs) is a new possible feature for screening osteoporosis. We developed an automated scheme for measuring MCT based on mandibular contour. The purpose of this study is to evaluate differences of measurement results by changing the measurement position of MCT. We employed 65 DPRs (44 cases and 21 osteoporotic cases) to evaluate the measurement methods. As a result, there were good correlations between MCTs based on the manual measurement and our scheme. It was concluded that our scheme has a potential to support dentists in screening osteoporosis on DPRs. (author)

  16. Validation of Airborne FMCW Radar Measurements of Snow Thickness Over Sea Ice in Antarctica

    Science.gov (United States)

    Galin, Natalia; Worby, Anthony; Markus, Thorsten; Leuschen, Carl; Gogineni, Prasad

    2012-01-01

    Antarctic sea ice and its snow cover are integral components of the global climate system, yet many aspects of their vertical dimensions are poorly understood, making their representation in global climate models poor. Remote sensing is the key to monitoring the dynamic nature of sea ice and its snow cover. Reliable and accurate snow thickness data are currently a highly sought after data product. Remotely sensed snow thickness measurements can provide an indication of precipitation levels, predicted to increase with effects of climate change in the polar regions. Airborne techniques provide a means for regional-scale estimation of snow depth and distribution. Accurate regional-scale snow thickness data will also facilitate an increase in the accuracy of sea ice thickness retrieval from satellite altimeter freeboard estimates. The airborne data sets are easier to validate with in situ measurements and are better suited to validating satellite algorithms when compared with in situ techniques. This is primarily due to two factors: better chance of getting coincident in situ and airborne data sets and the tractability of comparison between an in situ data set and the airborne data set averaged over the footprint of the antennas. A 28-GHz frequency modulated continuous wave (FMCW) radar loaned by the Center for Remote Sensing of Ice Sheets to the Australian Antarctic Division is used to measure snow thickness over sea ice in East Antarctica. Provided with the radar design parameters, the expected performance parameters of the radar are summarized. The necessary conditions for unambiguous identification of the airsnow and snowice layers for the radar are presented. Roughnesses of the snow and ice surfaces are found to be dominant determinants in the effectiveness of layer identification for this radar. Finally, this paper presents the first in situ validated snow thickness estimates over sea ice in Antarctica derived from an FMCW radar on a helicopterborne platform.

  17. International conference on bone mineral measurement, October 12--13, 1973, Chicago, Illinois

    Energy Technology Data Exchange (ETDEWEB)

    None

    1973-12-31

    From international conference on bone mineral measurement; Chicago, Illinois, USA (12 Oct 1973). Abstracts of papers presented at the international conference on bone mineral measurement are presented. The papers were grouped into two sessions: a physical session including papers on measuring techniques, errors, interpretation and correlations, dual photon techniques, and data handling and exchange; a biomedical session including papers on bone disease, osteoporosis, normative data, non-disease influences, renal, and activity and inactivity. (ERB)

  18. The thickness measurement of Sn-Ag hot dip coatings on LHC superconducting strands by coulometry

    CERN Document Server

    Arnau-Izquierdo, G; Oberli, L R; Scheuerlein, C; Taborelli, M

    2004-01-01

    Amperostatic coulometry is applied for the thickness measurement of Sn-Ag hot dip coatings, which comprise an extended Sn-Cu interdiffusion layer. Complementary measurements, notably weight loss, X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), X-ray fluorescence (XRF) and dynamic secondary ion mass spectroscopy (DSIMS) have been performed in order to obtain a better interpretation of the coulometry results. Based on the experimental results presented in this article the three potential changes that are observed during coulometry measurements are ascribed to (1) the entire dissolution of pure Sn, (2) the formation of a CuCl salt layer and (3) the surface passivation. The measurement of the pure Sn mass is well reproducible despite of strong coating thickness variations that are detected by XRF. Several experimental problems, in particular a coating undercutting, hamper the determination of the Sn mass in the intermetallic Sn-Cu layer.

  19. Transmission Nuclear Resonance Fluorescence Measurements of 238U in Thick Targets

    Energy Technology Data Exchange (ETDEWEB)

    Quiter, Brian J.; Ludewigt, Bernhard A.; Mozin, Vladimir V.; Wilson, Cody; Korbly, Steve

    2010-08-31

    Transmission nuclear resonance fluorescence measurements were made on targets consisting of Pb and depleted U with total areal densities near 86 g/cm2. The 238U content n the targets varied from 0 to 8.5percent (atom fraction). The experiment demonstrates the capability of using transmission measurements as a non-destructive technique to identify and quantify the presence of an isotope in samples with thicknesses comparable to he average thickness of a nuclear fuel assembly. The experimental data also appear to demonstrate the process of notch refilling with a predictable intensity. Comparison of measured spectra to previous backscatter 238U measurements indicates general agreement in observed excited states. Two new 238U excited states and possibly a third state have also been observed.

  20. Computer Simulation of Multiple Reflection Waves for Thickness Measurement by Ultrasonic Spectroscopy

    International Nuclear Information System (INIS)

    Ultrasonic spectroscopy is likely to become a very powerful NDE method for detection of microfects and thickness measurement of thin film below the limit of ultrasonic distance resolution in the opaque materials, provides a useful information that cannot be obtained by a conventional ultrasonic measuring system. In this paper, we considered a thin film below the limit of ultrasonic distance resolution sandwitched between two substances as acoustical analysis model, demonstrated the usefulness of ultrasonic spectroscopic analysis technique using information of ultrasonic frequency for measurements of thin film thickness, regardless of interference phenomenon and phase reversion of ultrasonic waveform. By using frequency intervals(Δf) of periodic minima from the ratio of reference power spectrum of reflective waveform obtained a sample to power spectrum of multiple reflective waves obtained interference phenomenon caused by ultrasonic waves reflected at the upper and lower surfaces of a thin layer, can measured even dimensions of interest are smaller than the ultrasonic wave length with simplicity and accuracy

  1. Measurement of neutron yield by 62 MeV proton beam on a thick Beryllium target

    CERN Document Server

    Alba, R; Boccaccio, P; Celentano, A; Colonna, N; Cosentino, G; Del Zoppo, A; Di Pietro, A; Esposito, J; Figuera, P; Finocchiaro, P; Kostyukov, A; Maiolino, C; Osipenko, M; Ricco, G; Ripani, M; Viberti, C M; Santonocito, D; Schillaci, M

    2012-01-01

    In the framework of research on IVth generation reactors and high intensity neutron sources a low-power prototype neutron amplifier was recently proposed by INFN. It is based on a low-energy, high current proton cyclotron, whose beam, impinging on a thick Beryllium converter, produces a fast neutron spectrum. The world database on the neutron yield from thick Beryllium target in the 70 MeV proton energy domain is rather scarce. The new measurement was performed at LNS, covering a wide angular range from 0 to 150 degrees and an almost complete neutron energy interval. In this contribution the preliminary data are discussed together with the proposed ADS facility.

  2. Measurement of neutron yield by 62 MeV proton beam on a thick Beryllium target

    International Nuclear Information System (INIS)

    In the framework of research on IVth generation reactors and high intensity neutron sources a low-power prototype neutron amplifier was recently proposed by INFN. It is based on a low-energy, high current proton cyclotron, whose beam, impinging on a thick Beryllium converter, produces a fast neutron spectrum. The world database on the neutron yield from thick Beryllium target in the 70 MeV proton energy domain is rather scarce. The new measurement was performed at LNS, covering a wide angular range from 0 to 150 degrees and an almost complete neutron energy interval. In this contribution the preliminary data are discussed together with the proposed ADS facility.

  3. Thickness Measurements from Single X-ray Phase-contrast Speckle Projection

    OpenAIRE

    Xi, Yan; Tang, Rongbiao; Ma, Jingchen; Zhao, Jun

    2015-01-01

    We propose a one-shot thickness measurement method for sponge-like structures using a propagation-based X-ray phase-contrast imaging (P-PCI) method. In P-PCI, the air-material interface refracts the incident X-ray. Refracted many times along their paths by such a structure, incident X-rays propagate randomly within a small divergent angle range, resulting in a speckle pattern in the captured image. We found structure thickness and contrast of a phase-contrast projection are directly related i...

  4. Thin film thickness measurement error reduction by wavelength selection in spectrophotometry

    International Nuclear Information System (INIS)

    Fast and accurate volumetric profilometry of thin film structures is an important problem in the electronic visual display industry. We propose to use spectrophotometry with a limited number of working wavelengths to achieve high-speed control and an approach to selecting the optimal working wavelengths to reduce the thickness measurement error. A simple expression for error estimation is presented and tested using a Monte Carlo simulation. The experimental setup is designed to confirm the stability of film thickness determination using a limited number of wavelengths

  5. Measurement of vertebral bone mineral by CT scanner

    International Nuclear Information System (INIS)

    Value of exp (-rho2l).107 was calculated from the averaged density rho (evaluated from averaged CT value) and mean radius l of the soft tissue surrounding the vertabral body. This value was found to well describe the beam hardening effect on the CT value of the vertebral body. We defined the exp (-rho2l).107 as ''Beam Hardening Index (for abbreviation, BHI)''. BHI's of patients were ranged from 10 to 1000, and the medium was about 100. Calibration curve for BHI of 100 can be satisfactorily used for almost all of the patients. Therefore, it becomes unnecessary to evaluate BHI for individual patient. For a patient whose bone mineral is extremely decreased, it is necessary to measure his BHI for selecting the most adequate calibration curve. (author)

  6. Intima-Media Thickness: Setting a Standard for a Completely Automated Method of Ultrasound Measurement

    OpenAIRE

    Molinari, Filippo

    2010-01-01

    The intima - media thickness (IMT) of the common carotid artery is a widely used clinical marker of severe cardiovascular diseases. IMT is usually manually measured on longitudinal B-Mode ultrasound images. Many computer-based techniques for IMT measurement have been proposed to overcome the limits of manual segmentation. Most of these, however, require a certain degree of user interaction. In this paper we describe a new completely automated layers extraction (CALEXia) technique for the segm...

  7. Measuring the thickness of austenitic weld deposits on carbon steel walls using a magnetic method

    International Nuclear Information System (INIS)

    The theoretical background is described of a magnetic method characterized by a marked compensation of the undesirable effect of δ-ferrite content in the deposit, on the accuracy of measuring deposit thickness. A description is also given of the basic types of sensors and the results are summarized of comparing measurements performed on weld deposits of WWER-type reactor pressure vessels. (author). 7 figs., 5 refs

  8. Process and device for measuring by ultrasonic probes the thickness of deposits

    International Nuclear Information System (INIS)

    At least two connected ultrasonic transducers are inserted and immersed in the water of the steam generator. At a first position the distances between the first transducer and the water surface and between the second transducer and the tube plate surface are measured. Similar measurements are made in various positions where the tube plate is covered with deposit. This allows the thickness of deposit to be determined from the distances

  9. The Observation on Development of Thickness of Cortical Bone in Children of Different Age%不同年龄组小儿骨皮质发育状况观察

    Institute of Scientific and Technical Information of China (English)

    宁刚; 吴康敏; 伍家农; 张光鹏; 杨定焯

    2000-01-01

    【 Objective】 In order to find out the pattern of development in cortical bone, a study of cortical bone in normal in-fants、 children、adolescence and adults were carried out. 【Methods】 The authors measured the transverse and inner diameter inmidpoint of the second metacarpal bone from 1 017 X- ray films of right wrist of normal infants、children、 adolescence and adults inthe urban and of infants in the suburban. The thickness and index of cortical bone in midpoint of the second metacarpal were calculat-ed by Microsoft Excel 97. 【 Results】 The increase of thickness of cortical bone was respectively 3.06 mm、2.89 mm for boys andgirls from 1.0 to 15.0 vr of age ,the average amplitude was respectively 4.0% 、4.3%, the latter was 8.2% 、6.9% for male and fe-male infants , 2.3 %、 2.0 % for infancy and preschool children, 10.7 % for girls at 11~13yr of age ,7.8 % for boys of 13~15yr ofage. Between urban areas and a rural area there were not significant differences between the transverse diameters in the secondmetacarpal of boys and girls at 1.0yr of age, but the average thickness of cortical bone were decreased of 0.39 mm in rural area ( P< 0.001 ). 【Conclusions】 The thickness of cortical bone increased significantly with age in children and adolescence , the in-creased velocity was more rapid during infncy nd puberty , with the pek thickness of corticl bone round puberty.%【目的】通过对正常婴幼儿、青少年及部分成年人骨皮质发育的横向观察,了解小儿骨皮质发育的规律。【方法】市郊农村健康婴儿,城区婴幼儿、青少年及部分成年人,共1 017例摄右手腕正位X光片,测量第二掌骨中点横径及内径,用Microsoft Excel97软件计算出骨皮质厚度、皮质指数并作统计学处理。【结果】从1岁组到15岁组男、女童骨皮质厚度分别增加了3.06mm及2.89mm,平均年增幅分别为4.0%及4.3%;婴儿期平均年增幅分别为8.2

  10. Measurements of liquid film thickness, concentration, and temperature of aqueous urea solution by NIR absorption spectroscopy

    Science.gov (United States)

    Pan, R.; Jeffries, J. B.; Dreier, T.; Schulz, C.

    2016-01-01

    A multi-wavelength near-infrared (NIR) diode laser absorption sensor has been developed and demonstrated for real-time monitoring of the thickness, solute concentration, and temperature of thin films of urea-water solutions. The sensor monitors the transmittance of three near-infrared diode lasers through the thin liquid film. Film thickness, urea mass fraction, and liquid temperature were determined from measured transmittance ratios of suitable combinations of lasers. Available laser wavelengths were selected depending on the variation of the NIR absorption spectrum of the solution with temperature and solute concentration. The spectral database was measured by a Fourier transform infrared spectrometer in the range 5500-8000 cm-1 for urea solutions between 5 and 40 wt% and temperatures between 298 and 338 K. A prototype sensor was constructed, and the sensor concept was first validated with measurements using a calibration cell providing liquid layers of variable thickness (200-1500 µm), urea mass fraction (5-40 wt%) and temperature (298-318 K). Temporal variations of film thickness and urea concentration were captured during the constant-temperature evaporation of a liquid film deposited on an optically polished heated quartz flat.

  11. Measurement of fundamental illite particle thicknesses by X-ray diffraction using PVP-10 intercalation

    Science.gov (United States)

    Eberl, D.D.; Nuesch, R.; Sucha, V.; Tsipursky, S.

    1998-01-01

    The thicknesses of fundamental illite particles that compose mixed-layer illite-smectite (I-S) crystals can be measured by X-ray diffraction (XRD) peak broadening techniques (Bertaut-Warren-Averbach [BWA] method and integral peak-width method) if the effects of swellinf and XRD background noise are eliminated from XRD patterns of the clays. Swelling is eliminated by intercalating Na-saturated I-S with polyvinylpyrrolidone having a molecular weightof 10,000 (PVP-10). Background is minimized by using polished metallic silicon wafers cut perpendicular to (100) as a substrate for XRD specimens, and by using a single-crystal monochromator. XRD measurements of PVP-intercalated diagenetic, hydro-thermal and low-grade metamorphic I-S indicate that there at least 2 type of crystallite thickness distribution shapes for illite fundamental particles, lognormal and asymptotic; that measurements of mean fundamental illite particle thicknesses made by various techniques (Bertaut-Warren-Averbach, integral peak width, fixed cation content, and transmission electron microscopy [TEM]) give comparable results; and that strain (small difference in layer thicknesses) generally has a Gaussian distribution in the lognormal-type illites, but is often absent in the asymptotic-type illites.

  12. Zirconium oxide layer thickness measurement on irradiated PHWR pressure tube by eddy current technique

    International Nuclear Information System (INIS)

    Hydriding is one of the life limiting factors in zircaloy pressure tubes in PHWRs. Hydrogen pick-up in the pressure tube is a direct consequence of the corrosion and oxidation of the internal surface of the pressure tube. Accelerated hydrogen pick-up starts after the oxide layer reaches a critical thickness. Hence development of a non-destructive method for measurement of oxide layer thickness in the pressure tube is very essential in monitoring the condition of the pressure tube in the reactor. Oxide layer thickness can be measured non-destructively using an eddy current technique. The probe contains an eddy current coil driven by a high frequency current which produces a varying magnetic field around the coil. The high frequency electromagnetic field produced by the coil penetrates the non conductive oxide layer and induces eddy currents in the conductive substrate. The eddy currents produce an opposing magnetic field that affects the impedance of the coil. Since the impedance variations are strongly dependent on the distance from the coil to the conducting base metal, the probe produces a voltage signal proportional to the thickness of the non-conductive oxide layer. The results from the development and use of this technique for oxide layer measurement in irradiated pressure tube is presented in this paper. (author)

  13. Development of oxide layer thickness measuring device for irradiated nuclear fuel rods in hot cell

    International Nuclear Information System (INIS)

    It has been known that water side corrosion of fuel rods in nuclear reactor is accompanied with the loss of metallic wall thickness and pickup of hydrogen. This corrosion is one of the important limiting factors in the operating life of fuel rods. In connection with the fuel cladding corrosion, a device to measure the water side oxide layer thickness by means of the eddy current method without destructing the fuel rod was developed by KAERI. The device was installed on the multi function testing bench in the nondestructive test hot cell and its calibration was carried out successfully for the standard rod attached with plastic thin films whose thicknesses are predetermined. It shows good precision within 10% error

  14. Thickness Measurement of a Film on a Substrate by Low-Frequency Ultrasound

    Institute of Scientific and Technical Information of China (English)

    LI Ming-Xuan; WANG Xiao-Min; MAO Jie

    2004-01-01

    @@ We describe a new simple technique for the low-frequency ultrasonic thickness measurement of an air-backed soft thin layer attached on a hard substrate of finite thickness through the frequency-shifts of the substrate resonances by the substrate-side insonification. A plane compressive wave impinging normally on the substrate surface from a liquid is studied. Low frequency here means an interrogating acoustical wave frequency of less than half of coating to the substrate. Equations for the frequency-shifts are derived and solved by the Newton iterative method and the Taylor expansion method, respectively, indicating satisfactory agreement within the range of interest of thickness ratio of the thin layer to the substrate for a polymer-aluminium structure. An experimental setup is constructed to verify the validity of the technique.

  15. Measurement of the dead layer thickness in a p-type point contact germanium detector

    CERN Document Server

    Jiang, H; Li, Y L; Kang, K J; Li, Y J; Li, J; Lin, S T; Liu, S K; Ma, H; Ma, J L; Su, J; Wong, H T; Yang, L T; Zhao, W; Zeng, Z

    2016-01-01

    A 994g mass p-type PCGe detector was deployed by the first phase of the China Dark matter EXperiment aiming at the direct searches of light weakly interacting massive particles. Measuring the thickness of the dead layer of a p-type germanium detector is an issue of major importance since it determines the fiducial mass of the detector. This work reports a method using an uncollimated 133Ba source to determine the dead layer thickness. The experimental design, data analysis and Monte Carlo simulation processes, as well as the statistical and systematic errors are described. An agreement between the experimental data and simulation results was achieved to derive the thickness of the dead layer of 1.02 mm.

  16. Radioactive apparatus for measuring the thickness of hot sheet-metal

    International Nuclear Information System (INIS)

    In order to achieve a high precision of measurement under rolling conditions, a dynamic method of compensation was chosen, by which the comparison parameter moves through all the values in the range of measurement, whereas the zero component designates only the moment when the measured parameter and the comparison parameter are equal. This method eliminates the mechanical return communications and variable displacements of the static-compensation method, and gives an instrument which is both sufficiently accurate and operates with sufficient speed in the complicated process of rolling. The basic design of the instrument, for checking the thickness of the sheet during the rolling process is described and the factors affecting the accuracy of measurement of a sheet (temperature, undulation, superficial moisture, composition of the sheet, and its position on the roller train) are discussed. The construction of an experimental instrument for industrial use over a thickness range of 14-44 mm is also described. The industrial tests carried out with the instrument showed that, with a Cs137 source of activity equivalent to 9.2 g radium, the accuracy of measurement of the thickness of hot sheet within the specified range is ±0.1 mm. The instrument's operating speed is one measurement per second. It works reliably under the conditions of the rolling mill. (author)

  17. Differential Intracochlear Sound Pressure Measurements in Normal Human Temporal Bones

    Science.gov (United States)

    Nakajima, Hideko Heidi; Dong, Wei; Olson, Elizabeth S.; Merchant, Saumil N.; Ravicz, Michael E.; Rosowski, John J.

    2009-02-01

    We present the first simultaneous sound pressure measurements in scala vestibuli and scala tympani of the cochlea in human cadaveric temporal bones. Micro-scale fiberoptic pressure sensors enabled the study of differential sound pressure at the cochlear base. This differential pressure is the input to the cochlear partition, driving cochlear waves and auditory transduction. Results showed that: pressure of scala vestibuli was much greater than scala tympani except at low and high frequencies where scala tympani pressure affects the input to the cochlea; the differential pressure proved to be an excellent measure of normal ossicular transduction of sound (shown to decrease 30-50 dB with ossicular disarticulation, whereas the individual scala pressures were significantly affected by non-ossicular conduction of sound at high frequencies); the middle-ear gain and differential pressure were generally bandpass in frequency dependence; and the middle-ear delay in the human was over twice that of the gerbil. Concurrent stapes velocity measurements allowed determination of the differential impedance across the partition and round-window impedance. The differential impedance was generally resistive, while the round-window impedance was consistent with a compliance in conjunction with distributed inertia and damping. Our techniques can be used to study inner-ear conductive pathologies (e.g., semicircular dehiscence), as well as non-ossicular cochlear stimulation (e.g., round-window stimulation) - situations that cannot be completely quantified by measurements of stapes velocity or scala-vestibuli pressure by themselves.

  18. Effect of in-painting on cortical thickness measurements in multiple sclerosis: A large cohort study.

    Science.gov (United States)

    Govindarajan, Koushik A; Datta, Sushmita; Hasan, Khader M; Choi, Sangbum; Rahbar, Mohammad H; Cofield, Stacey S; Cutter, Gary R; Lublin, Fred D; Wolinsky, Jerry S; Narayana, Ponnada A

    2015-10-01

    A comprehensive analysis of the effect of lesion in-painting on the estimation of cortical thickness using magnetic resonance imaging was performed on a large cohort of 918 relapsing-remitting multiple sclerosis patients who participated in a phase III multicenter clinical trial. An automatic lesion in-painting algorithm was developed and implemented. Cortical thickness was measured using the FreeSurfer pipeline with and without in-painting. The effect of in-painting was evaluated using FreeSurfer's paired analysis pipeline. Multivariate regression analysis was also performed with field strength and lesion load as additional factors. Overall, the estimated cortical thickness was different with in-painting than without. The effect of in-painting was observed to be region dependent, more significant in the left hemisphere compared to the right, was more prominent at 1.5 T relative to 3 T, and was greater at higher lesion volumes. Our results show that even for data acquired at 1.5 T in patients with high lesion load, the mean cortical thickness difference with and without in-painting is ∼2%. Based on these results, it appears that in-painting has only a small effect on the estimated regional and global cortical thickness. Hum Brain Mapp 36:3749-3760, 2015. © 2015 Wiley Periodicals, Inc. PMID:26096844

  19. Non-contact Measurement of Remaining Thickness of Corroding Superheater Tubes. Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Borggreen, Kjeld; Storesund, Jan

    2006-10-15

    Corrosion of superheaters has become a severe problem in many biomass boilers and incineration plants. This new situation calls for frequent tube wall thickness testing of the superheaters during very short shut-downs. To meet this demand Electro Magnetic Acoustic Transducer (EMAT) candidates as substitute for conventional manually operated contact UT-transducers. The EMAT can contactlessly generate an ultrasonic wave in the interphase between the external oxide and the metal. This means that measurements can be undertaken much quicker and with a much higher coverage simultaneously, without preceding blast operations. It is the aim of the project to demonstrate the usefulness of two simple EMAT systems, Panametrics and Sonatest, for fast and reliable tube thickness inspections in difficult-to-access superheater sections. The present Phase 1 of the project involves testing of the performance of the two systems in laboratory with the following results: 1. Both instruments work well on plate, tube, and pipe samples assuming the presence of an external oxide layer formed at a temperature above approximately 400 deg C. 2. Both instruments work well on all types of ferritic and martensitic steels but not on austenitic steels. 3. Both instruments work well independent of the thickness of the active oxide layer. 4. Both instruments work well independent of tube diameter, wall thickness, and sample width. 5. Both instruments work well over a very large range of wall thicknesses. Minimum tube wall thickness is less than 1.8 mm. 6. The tolerable lift-off (free distance between transducer and tube surface) is 2.4 - 3.0 mm for Panametrics system and 3.6 - 4.8 mm for Sonatest's system. The tolerable lift-off is a measure of the thickness of ash deposits, which can be tolerated on the tube surface as well as the misplacement, which can be tolerated in case of remote tube testing. 7. The tolerable off-set between tube axis and probe axis is very large for both instruments (10

  20. The Usefulness of Visceral Fat Thickness Measured by Ultrasonography as an Abdominal Obesity Index

    International Nuclear Information System (INIS)

    Abdominal obesity with visceral fat accumulation have been known to be intimately associated with the development of metabolic syndrome. Therefore, it is important to estimate the precise amount of visceral fat. Ultrasonography has been reported that it is a simple and noninvasive method for visceral fat evaluation. Purpose of this study is to evaluate the association of ultrasonographic visceral fat thickness, anthropometric indexes, and risk factor of metabolic syndrome, and to investigate the cut-off value of abdominal visceral fat thickness leading to increased risk of metabolic syndrome. The subject included 200 men and 200 women who visited D healthcare center in Daejeon from January to April 2008. The subcutaneous fat thickness and visceral fat thickness were measured by ultrasonograph. As anthropometric index, we measured body mass index, waist circumference and waist/height ratio. As for the risk factor of metabolic syndrome, we measured blood pressure, high density lipoprotein cholesterol, triglyceride and fasting serum glucose. VFT was significantly correlated with waist circumference, (r=0.683/M, r=0.604/F), waist to height ratio (r=0.633/M, r=0.593/F) and BMI (r=0.621/M, r=0.534/F) in both men and women. In addition it was significantly correlated with Systolic blood pressure (r=0.229/M, r=0.232/F), Diastolic blood pressure ((r=0.285/M, r=0.254/F), high density cholesterol (r=-0.254/M, r=-0.254/F), Triglyceride (r=0.475/M, r=0.411/F), and Fasting blood sugar (r=0.158/M, r=0.234/F) in both men and women. The cut-off value of visceral fat thickness leading to the increased risk of metabolic syndrome was 4.58 cm (sensitivity 89.2%, specificity 71.2%) in men and 3.50 cm (sensitivity 61.2% specificity 80.8%) in women respectively. The odds ratio of the risk of metabolic syndrome was dramatically increased with the abdominal visceral fat thickness level over 6 cm in men and 5 cm in women. The visceral fat thickness using ultrasonography was significantly

  1. The Usefulness of Visceral Fat Thickness Measured by Ultrasonography as an Abdominal Obesity Index

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Kyun [Dept. of Diagnostic Radiology, Korealife Daejeon Healthcare Center, Daejeon (Korea, Republic of); Han, Man Seok [Dept. of Diagnostic Radiology, Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2008-09-15

    Abdominal obesity with visceral fat accumulation have been known to be intimately associated with the development of metabolic syndrome. Therefore, it is important to estimate the precise amount of visceral fat. Ultrasonography has been reported that it is a simple and noninvasive method for visceral fat evaluation. Purpose of this study is to evaluate the association of ultrasonographic visceral fat thickness, anthropometric indexes, and risk factor of metabolic syndrome, and to investigate the cut-off value of abdominal visceral fat thickness leading to increased risk of metabolic syndrome. The subject included 200 men and 200 women who visited D healthcare center in Daejeon from January to April 2008. The subcutaneous fat thickness and visceral fat thickness were measured by ultrasonograph. As anthropometric index, we measured body mass index, waist circumference and waist/height ratio. As for the risk factor of metabolic syndrome, we measured blood pressure, high density lipoprotein cholesterol, triglyceride and fasting serum glucose. VFT was significantly correlated with waist circumference, (r=0.683/M, r=0.604/F), waist to height ratio (r=0.633/M, r=0.593/F) and BMI (r=0.621/M, r=0.534/F) in both men and women. In addition it was significantly correlated with Systolic blood pressure (r=0.229/M, r=0.232/F), Diastolic blood pressure ((r=0.285/M, r=0.254/F), high density cholesterol (r=-0.254/M, r=-0.254/F), Triglyceride (r=0.475/M, r=0.411/F), and Fasting blood sugar (r=0.158/M, r=0.234/F) in both men and women. The cut-off value of visceral fat thickness leading to the increased risk of metabolic syndrome was 4.58 cm (sensitivity 89.2%, specificity 71.2%) in men and 3.50 cm (sensitivity 61.2% specificity 80.8%) in women respectively. The odds ratio of the risk of metabolic syndrome was dramatically increased with the abdominal visceral fat thickness level over 6 cm in men and 5 cm in women. The visceral fat thickness using ultrasonography was significantly

  2. Development of PVDF Ultrasonic Array Transducer for Thickness Measurement of the PHWR Feeders

    International Nuclear Information System (INIS)

    The feeder pipes in a Pressurized Heavy Water Reactor (PHWR) are installed with a very complicated form in close order. As corrosion and erosion occurs in the bent region of the feeder pipe, inspection of the pipe is required. However, there are two problems for the thickness measurement. One is accessibility and the other is the high radiation environment. In the field, the conventional ultrasonic thickness measurement was applied manually to check the nine points in the bent region. One possible approach under the high radiation environment is to use the special robot for inspection. Furthermore, it is not easy to access because of the narrow gap among the pipes, it is also necessary to move freely on the pipe with the thin transducer. In this study, we have fabricated the PVDF array transducer to meet the dimension requirement passing smoothly along the pipe and have evaluated the signals in order to investigate the accuracy of measurement

  3. Sea ice thickness measurements collected during the LOMROG 2007 and 2009 expeditions

    DEFF Research Database (Denmark)

    Skourup, Henriette; Forsberg, René; Hanson, Susanne;

    2009 we have collected a unique data set of late summer sea ice thickness, freeboard height and snow depth from the high Arctic Ocean during the time of the annual minimum sea ice extent. The data were collected by on-the-ground drilling and EM measurements. Here we give a brief overview of the data......According to scientific measurements, the Arctic sea ice extent has declined dramatically over the past thirty years, with the most extreme decline seen in the summer melt season. Other observations indicate that the sea ice has become thinner and perennial ice less widely distributed. The...... collection, as well as the results including the freeboard-to-sea-ice thickness conversion factor, which is used when interpreting freeboard heights measured by remote sensing....

  4. A setup for simultaneously measureing the thermopower and electrical conductivity of μm-thickness specimens

    Science.gov (United States)

    Chen, Chih-Ting; Lee, P. C.; Chen, Y. Y.; Harutyungyan, Sergey

    2008-03-01

    We report the concept and configuration of our new setup for measurement of thermopower and electrical conductivity for μm-thickness specimens, especially for thermoelectric materials. It is very difficult and tedious to accurately measure the thermopower for specimens with thickness less than ˜100 μm due to the limitations of smallest size ˜25μm of thermocouples. Such are obvious when applied to the measurement of nanowire arrays and multilayer . In order to resolve these difficulties, we developed a new setup with integration of Pt-film thermometers and electrical electrodes on two sapphire chips used to clamp specimens with thickness >40 μm and cross section 2 x 3 mm^2. Use this setup the thermopower and electric conductivity can be measured simultaneously for temperature range 20-400 K. The advantages of the setup are (1) accuracy: the real temperatures of both sides of the sample can be obtained. (2) convenience for loading samples: just assemble the sample between the two microchips and make sure of a good thermal and electrical contacts. A Bi2Te3 nanowire array in AAO template was tested, the thermopower ˜ 50μV/K was measured for diameter ˜ 60 nm of nanowires.

  5. Measurements of the dependence of damage thresholds on laser wavelength, pulse duration and film thickness

    International Nuclear Information System (INIS)

    Results of three experiments will be described. We used 351-nm and 355-nm pulses with durations of 0.6, 1, 5 and 9 ns measure thresholds for a variety of anti-reflectance and high reflectance coatings. The functional form t/sup m/, with t the pulse duration, was used to scale fluence thresholds measured at 0.6 ns to those measured at 9.0 ns. Values of the coefficient m ranged from 0.10 to 0.51. The average value was 0.30. In the second experiment, we measured thresholds at 1064 nm, 527 nm and 355 nm for single-frequency high reflectance ZrO2/SiO2 coatings. Coatings for all three frequencies were deposited simultaneously by use of masks in the coating chamber. Thresholds varied from 2 to 4 J/cm2 at 355 nm to 7 to 10 J/cm2 at 1064 nm. The third experiment measured thresholds at 355 nm for antireflection coatings made with layer thicknesses varying from greater than one wavelength to less than a quarterwavelength. A significant variation of threshold with coating thickness was not observed, but the median thresholds increased slightly as coating thickness increased

  6. Image processing techniques for measuring non-uniform film thickness profiles

    Energy Technology Data Exchange (ETDEWEB)

    Nitta, S.V.; Liu, An-Hong; Plawsky, J.L.; Wayner, P.C. Jr. [Rensselaer Polytechnique Institute, Troy, NY (United States)

    1996-12-31

    The long term objective of this research program is to determine the fluid flow and drying characteristics of thin liquid/solid films using image processing techniques such as Image Analyzing Interferometry (IAI) and Image Scanning Ellipsometry (ISE). The primary purpose of this paper is to present experimental data on the effectiveness of IAI and ISE to measure nonuniform film thickness profiles. Steady-state, non-isothermal profiles of evaporating films were measured using IAI. Transient thickness profiles of a draining film were measured using ISE. The two techniques are then compared and contrasted. The ISE can be used to measure transient as well as steady-state profiles of films with thickness ranging from 1 nm to > 20 {mu}m, whereas IAI can be used to directly measure Steady-state and transient profiles of only films thicker than about 100 nm. An evaluation of the reflected intensity can be used to extend the use of the IAI below 100 nm.

  7. Three-dimensional direct measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections

    Science.gov (United States)

    Bensley, Jonathan Guy; de Matteo, Robert; Harding, Richard; Black, Mary Jane

    2016-04-01

    Quantitative assessment of myocardial development and disease requires accurate measurement of cardiomyocyte volume, nuclearity (nuclei per cell), and ploidy (genome copies per cell). Current methods require enzymatically isolating cells, which excludes the use of archived tissue, or serial sectioning. We describe a method of analysis that permits the direct simultaneous measurement of cardiomyocyte volume, nuclearity, and ploidy in thick histological sections. To demonstrate the utility of our technique, heart tissue was obtained from four species (rat, mouse, rabbit, sheep) at up to three life stages: prenatal, weaning and adulthood. Thick (40 μm) paraffin sections were stained with Wheat Germ Agglutinin-Alexa Fluor 488 to visualise cell membranes, and DAPI (4‧,6-diamidino-2-phenylindole) to visualise nuclei and measure ploidy. Previous methods have been restricted to thin sections (2–10 μm) and offer an incomplete picture of cardiomyocytes. Using confocal microscopy and three-dimensional image analysis software (Imaris Version 8.2, Bitplane AG, Switzerland), cardiomyocyte volume, nuclearity, and ploidy were measured. This method of staining and analysis of cardiomyocytes enables accurate morphometric measurements in thick histological sections, thus unlocking the potential of archived tissue. Our novel time-efficient method permits the entire cardiomyocyte to be visualised directly in 3D, eliminating the need for precise alignment of serial sections.

  8. Non-contact optical measurement of lens capsule thickness during simulated accommodation

    Science.gov (United States)

    Ziebarth, Noel; Manns, Fabrice; Acosta, Ana-Carolina; Parel, Jean-Marie

    2005-04-01

    Purpose: To non-invasively measure the thickness of the anterior and posterior lens capsule, and to determine if it significantly changes during accommodation. Methods: Anterior and posterior capsule thickness was measured on post-mortem lenses using a non-contact optical system using a focus-detection technique. The optical system uses a 670nm laser beam delivered to a single-mode fiber coupler. The output of the fiber coupler is focused on the tissue surface using an aspheric lens (NA=0.68) mounted on a translation stage with a motorized actuator. Light reflected from the sample surface is collected by the fiber coupler and sent to a photoreceiver connected to a computer-controlled data acquisition system. Optical intensity peaks are detected when the aspheric lens is focused on the capsule boundaries. The capsule thickness is equal to the distance traveled between two peaks multiplied by the capsule refractive index. Anterior and posterior lens capsule thickness measurements were performed on 18 cynomolgus (age average: 6+/-1 years, range: 4-7 years) eyes, 1 rhesus (age: 2 years) eye, and 12 human (age average: 65+/-16, range: 47-92) eyes during simulated accommodation. The mounted sample was placed under the focusing objective of the optical system so that the light was incident on the center pole. Measurements were taken of the anterior lens capsule in the unstretched and the stretched 5mm states. The lens was flipped, and the same procedure was performed for the posterior lens capsule. Results: The precision of the optical system was determined to be +/-0.5um. The resolution is 4um and the sensitivity is 52dB. The human anterior lens capsule thickness was 6.0+/-1.2um unstretched and 4.9+/-0.9um stretched (p=0.008). The human posterior lens capsule was 5.7+/-1.2um unstretched and 5.7+/-1.4um stretched (p=0.974). The monkey anterior lens capsule thickness was 5.9+/-1.9um unstretched and 4.8+/-1.0um stretched (p=0.002). The monkey posterior lens capsule was 5

  9. Chest Wall Thickness Measurements and the Dosimetric Implications for Male Radiation Workers at the KAERI

    International Nuclear Information System (INIS)

    Using ultrasound techniques, the Korea Atomic Energy Research Institute has measured chest wall thicknesses of a group of male workers at the Korea Atomic Energy Research Institute. A site-specific biometric equation has been developed for these workers. Chest wall thickness is an important modifier on lung counting efficiency. These data have been put into the perspective of the ICRP recommended dose limits for occupationally exposed workers:100 mSv in a 5-year period with a maximum of 50 mSv in any one year. For measured chest wall thicknesses of 1.9 cm to 4.1 cm and a 30 min counting time, the achievable MDAs for natural uranium in the KAERI lung counter vary from 5.75 mg to 11.28 mg. These values are close to, or even exceed, the predicted amounts of natural uranium that will remain in the lung (absorption type M and S) after an intake equal to the Annual Limit on Intake corresponding to a committed dose of 20 mSv. This paper shows that the KAERI lung counter probably cannot detect an intake of Type S natural uranium in a worker with a chest wall thickness equal to the average value (2.7 cm) under routine counting conditions

  10. The importance of ultrasonographic measurement of peritoneal wall thickness in pediatric chronic peritoneal dialysis patients.

    Science.gov (United States)

    Yavaşcan, Önder; Aksu, Nejat; Alparslan, Caner; Sarıtaş, Serdar; Elmas, Cengiz Han; Eraslan, Ali Nihat; Duman, Soner; Mir, Sevgi

    2015-04-01

    Loss of peritoneal function due to peritoneal fibrosing syndrome (PFS) is a major factor leading to treatment failure in chronic peritoneal dialysis (PD) patients. Although the precise biologic mechanisms responsible for these changes have not been defined, the general assumption is that alterations in peritoneal function are related to structural changes in the peritoneal membrane. Studies of the peritoneal membrane by non-invasive ultrasonography (US) in chronic PD patients are limited. The aim of the present study is to assess the relationship between functional parameters of peritoneum and peritoneal thickness measured by US in children treated by chronic PD. We recruited two groups of patients: 23 subjects (13 females, 10 males) on chronic PD (patient group) and 26 (7 females, 19 males) on predialysis out-patient follow-up (creatinine clearance: 20-60 mL/min/1.73 m(2)) (control group). Age, sex, weight, height, body mass index (BMI), chronic PD duration, episodes of peritonitis and the results of peritoneal equilibration test (PET) were recorded. Hemoglobin (Hb), blood pressure (BP), left ventricular mass index (LVMI) and renal osteodystrophy (ROD) parameters were also obtained. The thickness of the parietal peritoneum was measured by trans-abdominal US in all children. Statistical analyses were performed by using Student's t and Pearson's correlation tests. Mean peritoneal thickness in chronic PD patients (1028.26 ± 157.26 μm) was significantly higher than control patients (786.52 ± 132.33). Mean peritoneal thickness was significantly correlated with mean body height (R(2) = 0.93, p measurement of peritoneal membrane thickness is a simple and non-invasive method in chronic PD children. This diagnostic tool likely enables to assess peritoneal structure and function in these patients. PMID:25594613

  11. Ultrasonographic evaluation of reproductive tract measures and fat thickness traits in pre-pubertal Nellore heifers

    Directory of Open Access Journals (Sweden)

    Fabio Morato Monteiro

    2012-02-01

    Full Text Available The aim of this study was to evaluate the relationship between reproductive tract and fat thickness measures obtained by ultrasound in prepubertal Nellore heifers. A total of 128 Nellore heifers born in 2006 and 2007 were submitted to ultrasound evaluations (13, 16, 19 and 22 months of age of reproductive tract measures and fat thickness traits. These animals were from a selection experiment (NeC: control line, and NeS: selection line for yearling weight started in 1981. Mean values of ovary area, height of the right uterine horn (HU, maximum follicular diameter (FOL, backfat thickness (BF, rump fat thickness (RF, and body condition score were analyzed. Repeated records were modeled using the PROC MIXED procedure (SAS, fitting a model that included the selection line, year of birth, measurement as fixed effects, and interactions. Body weight differed between the selected (281.48 kg and control (210.51 kg lines. Only the least square means of FOL were lower in the NeC line compared to the NeS line (P < 0.05, although the difference in mean HU between the two lines was of only borderline significance (P = 0.06. The rate of growth for the three reproductive traits was similar in the two lines. Simple and residual correlations between the reproductive and subcutaneous fat traits ranged from low to medium. The highest correlations were observed between HU and RF (Pearson correlation = 0.71 and residual correlation = 0.34. The current results are consistent with the literature, indicating that fat thickness traits are not good predictors of prepubertal reproductive traits in heifers. Further studies are necessary to clarify the relationship between reproduction and body fat in Nellore heifers.

  12. Measuring method for thickness of liner of outer surface lined tube

    International Nuclear Information System (INIS)

    The device of the present invention provide a method of measuring the thickness of a liner of a tube lined at the outer surface in which properties of the constitutional materials are similar as in the outer surface lining used for a fuel cladding tube of a PWR type reactor. Namely, the lined tube is lined at the outer surface with a material different from the material of the mother tube. Supersonic waves are injected from the inner surface of the tube. The thickness of the outer surface liner is measured based on the reflected waves. In particular, the measurement is conducted under the conditions that the thickness of the liner is not greater than 3mm, the supersonic wave propagation speed in the mother tube and the liner is not more than 100m/min, and electric resistance is not more than 20μΩcm. In addition, the method is applied in a case of the outer surface lined tube of a PWR nuclear fuel cladding tube comprising an ordinary Zr based alloy containing from 0.4 to 1.6% of Sn on the weight basis, and with an outer surface lined with a low Sn based alloy containing from 0.4 to 0.6% of Sn on the weight basis. According to the present invention, since the property of the constitutional materials of the mother tube and those of the liner are similar to each other, the thickness of the liner of the outer surface lined tube can be measured non-destructively, which could not be measured non-destructively so far. (I.S.)

  13. A reliable control system for measurement on film thickness in copper chemical mechanical planarization system

    International Nuclear Information System (INIS)

    In recent years, a variety of film thickness measurement techniques for copper chemical mechanical planarization (CMP) are subsequently proposed. In this paper, the eddy-current technique is used. In the control system of the CMP tool developed in the State Key Laboratory of Tribology, there are in situ module and off-line module for measurement subsystem. The in situ module can get the thickness of copper film on wafer surface in real time, and accurately judge when the CMP process should stop. This is called end-point detection. The off-line module is used for multi-points measurement after CMP process, in order to know the thickness of remained copper film. The whole control system is structured with two levels, and the physical connection between the upper and the lower is achieved by the industrial Ethernet. The process flow includes calibration and measurement, and there are different algorithms for two modules. In the process of software development, C++ is chosen as the programming language, in combination with Qt OpenSource to design two modules’ GUI and OPC technology to implement the communication between the two levels. In addition, the drawing function is developed relying on Matlab, enriching the software functions of the off-line module. The result shows that the control system is running stably after repeated tests and practical operations for a long time

  14. A reliable control system for measurement on film thickness in copper chemical mechanical planarization system

    Science.gov (United States)

    Li, Hongkai; Qu, Zilian; Zhao, Qian; Tian, Fangxin; Zhao, Dewen; Meng, Yonggang; Lu, Xinchun

    2013-12-01

    In recent years, a variety of film thickness measurement techniques for copper chemical mechanical planarization (CMP) are subsequently proposed. In this paper, the eddy-current technique is used. In the control system of the CMP tool developed in the State Key Laboratory of Tribology, there are in situ module and off-line module for measurement subsystem. The in situ module can get the thickness of copper film on wafer surface in real time, and accurately judge when the CMP process should stop. This is called end-point detection. The off-line module is used for multi-points measurement after CMP process, in order to know the thickness of remained copper film. The whole control system is structured with two levels, and the physical connection between the upper and the lower is achieved by the industrial Ethernet. The process flow includes calibration and measurement, and there are different algorithms for two modules. In the process of software development, C++ is chosen as the programming language, in combination with Qt OpenSource to design two modules' GUI and OPC technology to implement the communication between the two levels. In addition, the drawing function is developed relying on Matlab, enriching the software functions of the off-line module. The result shows that the control system is running stably after repeated tests and practical operations for a long time.

  15. Chest wall thickness measurements and the dosimetric implications for male workers in the uranium industry

    International Nuclear Information System (INIS)

    The Human Monitoring Laboratory has measured the chest wall thickness and adipose mass fraction of a group of workers at three Canadian uranium refinery, conversion plant, and fuel fabrication sites using ultrasound. A site specific biometric equation has been developed for these workers, who seem to be somewhat larger than other workers reported in the literature. The average chest wall thickness of the seated persons measured at the uranium conversion plant and refinery was about 3.8 cm, and at the fuel fabrication facility was 3.4 cm. These values are not statistically different. Persons measured in a seated geometry had a thinner chest wall thickness than persons measured in a supine geometry - the decrease was in the range of 0.3 cm to 0.5 cm. It follows that a seated geometry will give a lower MDA (or decision level) than a supine geometry. Chest wall thickness is a very important modifier for lung counting efficiency and this data has been put into the perspective of the impending Canadian dose limits that will reduce the limit of occupationally exposed workers to essentially 20 mSv per year. Natural uranium must be measured based on the 235U emissions at these type of facilities. The refining and conversion process removes 234Th and the equilibrium is disturbed. This is unfortunate as the MDA values for this nuclide are approximately a factor of three lower than the values quoted below. The sensitivity of the germanium and phoswich based lung counting system has been compared. Achievable MDA's (30 minute counting time) with a four-phoswich-detector array lie in the range of 4.7 mg to 13.5 mg of natural uranium based on the 235U emissions over a range of chest wall thicknesses of 1.6 cm to 6.0 cm. The average achievable MDA is about 8.5 mg which can be reduced to about 6.2 mg by doubling the counting time. Similarly, MDA's (30 minute counting time) obtainable with a germanium lung counting system will lie in the range of 3 mg to 28 mg of natural uranium

  16. Measurement of resonances in 12 C + 4 He through inverse kinematics with thick targets

    International Nuclear Information System (INIS)

    The excitation function of elastic scattering for the system 12 C + 4 He to energy from 0.5 to 3.5 MeV in the center of mass system (c.m.) was measured. We use a gassy thick target and the technique of inverse kinematics which allows to make measurements at 180 degrees in c.m. Using the R matrix theory those was deduced parameters of the resonances and the results were compared with measurements reported in the literature made with other techniques. (Author)

  17. The reliability and representativity of non-dynamic bone histomorphometry in uremic osteodystrophy

    DEFF Research Database (Denmark)

    Heaf, J G; Pødenphant, J; Gammelgaard, Bente

    1993-01-01

    -left correlation coefficients were found for bone volume, osteoid volume, osteoid surface, osteoid thickness, eroded surface, osteoclast surface and aluminium labelling intensity; moderate (0.7-0.8) for trabecular thickness, and low (<0.7) for cortical thickness, porosity and aluminium bone concentration. High...... iliac crest-vertebra correlations were found for trabecular thickness, osteoid volume, osteoid surface, eroded surface, osteoclast surface and aluminium labelling intensity, and low correlations for bone volume, osteoid thickness and bone aluminium concentration. In conclusion, non-dynamic iliac...... trabecular bone indices are reliable variables and, with the possible exception of bone mass determination, indicative of systemic bone disease. Bone aluminium concentration and cortical bone indices are unreliable measures of uremic bone disease. These reservations apply to the diagnostic use of biopsy in...

  18. Oil film thickness measurement using airborne laser-induced water Raman backscatter

    Science.gov (United States)

    Hoge, F. E.; Swift, R. N.

    1980-01-01

    The use of laser-induced water Raman backscatter for remote thin oil film detection and thickness measurement is reported here for the first time. A 337.1-nm nitrogen laser was used to excite the 3400-cm-1 OH stretch band of natural ocean water beneath the oil slick from an altitude of 150 m. The signal strength of the 381-nm water Raman backscatter was always observed to depress when the oil was encountered and then return to its original undepressed value after complete aircraft traversal of the floating slick. After removal of background and oil fluorescence contributions, the ratio of the depressed-to-undepressed airborne water Raman signal intensities, together with laboratory measured oil extinction coefficients, is used to calculate the oil film thickness.

  19. Thickness Measurements from Single X-ray Phase-contrast Speckle Projection

    CERN Document Server

    Xi, Yan; Ma, Jingchen; Zhao, Jun

    2015-01-01

    We propose a one-shot thickness measurement method for sponge-like structures using a propagation-based X-ray phase-contrast imaging (P-PCI) method. In P-PCI, the air-material interface refracts the incident X-ray. Refracted many times along their paths by such a structure, incident X-rays propagate randomly within a small divergent angle range, resulting in a speckle pattern in the captured image. We found structure thickness and contrast of a phase-contrast projection are directly related in images. This relationship can be described by a natural logarithm equation. Thus, from the one phase-contrast view, depth information can be retrieved from its contrast. Our preliminary biological experiments indicate promise in its application to measurements requiring in vivo and ongoing assessment of lung tumor progression.

  20. Highly accurate thickness measurement of multi-layered automotive paints using terahertz technology

    Science.gov (United States)

    Krimi, Soufiene; Klier, Jens; Jonuscheit, Joachim; von Freymann, Georg; Urbansky, Ralph; Beigang, René

    2016-07-01

    In this contribution, we present a highly accurate approach for thickness measurements of multi-layered automotive paints using terahertz time domain spectroscopy in reflection geometry. The proposed method combines the benefits of a model-based material parameters extraction method to calibrate the paint coatings, a generalized Rouard's method to simulate the terahertz radiation behavior within arbitrary thin films, and the robustness of a powerful evolutionary optimization algorithm to increase the sensitivity of the minimum thickness measurement limit. Within the framework of this work, a self-calibration model is introduced, which takes into consideration the real industrial challenges such as the effect of wet-on-wet spray in the painting process.

  1. Computed tomographic measurement of gluteal subcutaneous fat thickness in reference to failure of gluteal intramuscular injections

    Energy Technology Data Exchange (ETDEWEB)

    Burbridge, B.E. [Univ. of Saskatchewan, Royal Univ. Hospital, Academic Dept. of Medical Imaging, Saskatoon, Saskatchewan (Canada)]. E-mail: brent.burbridge@usask.ca

    2007-04-15

    Casual observation of gluteal region fat thickness on computed tomography (CT) of the pelvis leads to the hypothesis that, in some individuals intended intramuscular injections are not properly deposited in the gluteal muscle. We gathered and analyzed data to determine whether this hypothesis was true. CT scans of the pelvis were analyzed over an 18-day period in the tall of 2005. The thickness of gluteal region subcutaneous fat was measured in a standardized manner. Measurement of gluteal region subcutaneous fat thickness was performed for 298 pelvic CT scans. There were 150 male subjects and 148 female subjects. The average gluteal fat thickness for female subjects was 33.2 mm, whereas the average for male subjects was 23.1 mm. Analysis revealed a significant difference in gluteal region fat thickness between male and female subjects. A 37-mm needle, allowing for 6-mm penetration of the gluteal muscle, would not have entered the gluteal muscle fibres in 81 of 148 female subjects (54.7%), in 21 of 150 male subjects (14%), and in 102 of the 298 total sample (34.2%). Analysis revealed a significant difference between male and female subjects with regard to gluteal muscle needle penetration. An overall predicted failure rate of 34% was identified for intended gluteal intramuscular injections when the standard technique was used. This is important information for care providers who inject medications in the gluteal region. In a significant number of patients, the medications will be injected subcutaneously and not into the gluteal musculature, possibly altering the pharmacokinetics of the administered medication. An alternative injection site should probably be chosen to increase the success rate of intramuscular deposition of medications and vaccines in unselected adults. (author)

  2. Computed tomographic measurement of gluteal subcutaneous fat thickness in reference to failure of gluteal intramuscular injections

    International Nuclear Information System (INIS)

    Casual observation of gluteal region fat thickness on computed tomography (CT) of the pelvis leads to the hypothesis that, in some individuals intended intramuscular injections are not properly deposited in the gluteal muscle. We gathered and analyzed data to determine whether this hypothesis was true. CT scans of the pelvis were analyzed over an 18-day period in the tall of 2005. The thickness of gluteal region subcutaneous fat was measured in a standardized manner. Measurement of gluteal region subcutaneous fat thickness was performed for 298 pelvic CT scans. There were 150 male subjects and 148 female subjects. The average gluteal fat thickness for female subjects was 33.2 mm, whereas the average for male subjects was 23.1 mm. Analysis revealed a significant difference in gluteal region fat thickness between male and female subjects. A 37-mm needle, allowing for 6-mm penetration of the gluteal muscle, would not have entered the gluteal muscle fibres in 81 of 148 female subjects (54.7%), in 21 of 150 male subjects (14%), and in 102 of the 298 total sample (34.2%). Analysis revealed a significant difference between male and female subjects with regard to gluteal muscle needle penetration. An overall predicted failure rate of 34% was identified for intended gluteal intramuscular injections when the standard technique was used. This is important information for care providers who inject medications in the gluteal region. In a significant number of patients, the medications will be injected subcutaneously and not into the gluteal musculature, possibly altering the pharmacokinetics of the administered medication. An alternative injection site should probably be chosen to increase the success rate of intramuscular deposition of medications and vaccines in unselected adults. (author)

  3. Adaptive ultrasonic measurement of blood vessel diameter and wall thickness: theory and experimental results.

    Science.gov (United States)

    Rafii, K; Jaffe, J S

    1998-01-01

    An adaptive ultrasonic technique for measuring blood vessel diameter and wall thickness is presented. This technique allows one to use a target-specific transmitted waveform/receiver filter to obtain a larger signal-to-noise ratio (SNR) in the received signal than conventional techniques. Generally, SNR of a received wave increases as the intensity of the transmit wave increases; however, because of the FDA limitations placed on the amount of transmit energy, it is important to be able to make the most efficient use of the energy that is available to obtain the best possible SNR in the received signal. Adaptive ultrasonic measurement makes the most efficient use of the energy that is available by placing the maximum amount of energy in the largest target scattering mode. This results in more energy backscatter from a given target, which leads to a higher SNR in the received waveform. Computer simulations of adaptive ultrasonic measurement of blood vessel diameter show that for a SNR of 0 dB in the transmitted waveform, the standard deviation of the diameter measurements for a custom-designed transmitted waveform is about two orders of magnitude less than the standard deviation of the diameter measurements using more conventional waveforms. Diameter and wall thickness measurement experiments were performed on a latex tube and a bovine blood vessel using both custom-made and conventionally used transmitted waveforms. Results show that the adaptively designed waveform gives a smaller uncertainty in the measurements. The adaptive ultrasonic blood vessel diameter and wall thickness measuring technique has potential applications in examining vessels which are either too deep inside the body or too small for conventional techniques to be used, because of the low SNR in the received signal. PMID:18244211

  4. Spatial resolution and measurement uncertainty of strains in bone and bone-cement interface using digital volume correlation.

    Science.gov (United States)

    Zhu, Ming-Liang; Zhang, Qing-Hang; Lupton, Colin; Tong, Jie

    2016-04-01

    The measurement uncertainty of strains has been assessed in a bone analogue (sawbone), bovine trabecular bone and bone-cement interface specimens under zero load using the Digital Volume Correlation (DVC) method. The effects of sub-volume size, sample constraint and preload on the measured strain uncertainty have been examined. There is generally a trade-off between the measurement uncertainty and the spatial resolution. Suitable sub-volume sizes have been be selected based on a compromise between the measurement uncertainty and the spatial resolution of the cases considered. A ratio of sub-volume size to a microstructure characteristic (Tb.Sp) was introduced to reflect a suitable spatial resolution, and the measurement uncertainty associated was assessed. Specifically, ratios between 1.6 and 4 appear to give rise to standard deviations in the measured strains between 166 and 620 με in all the cases considered, which would seem to suffice for strain analysis in pre as well as post yield loading regimes. A microscale finite element (μFE) model was built from the CT images of the sawbone, and the results from the μFE model and a continuum FE model were compared with those from the DVC. The strain results were found to differ significantly between the two methods at tissue level, consistent in trend with the results found in human bones, indicating mainly a limitation of the current DVC method in mapping strains at this level. PMID:26741534

  5. Reproducibility of peripapillary retinal nerve fiber layer thickness measurements using Spectral Domain OCT in Brazilian patients

    Directory of Open Access Journals (Sweden)

    Daniela Araújo Toscano

    2012-10-01

    Full Text Available PURPOSE: To evaluate the reproducibility of peripapillary retinal nerve fiber layer (RNFL thickness measurements in normal eyes and eyes with glaucoma using spectral domain optical coherence tomography (SDOCT. METHODS: One eye of 79 normal and 72 glaucoma patients was analyzed. All patients underwent a complete ophthalmological examination, including visual acuity testing; intraocular pressure, slit-lamp examination, indirect ophthalmoscopy; and the glaucoma group underwent achromatic perimetry with the 24-2 SITA Fast Humphrey Field Analyzer. All patients' eyes were scanned using the spectral domain optical coherence tomography - Spectralis® and one of them was chosen randomly. Three consecutive circular B-scan centered at the optic disc were performed in one visit. RESULTS: The intraclass correlation coefficient (ICC, coefficient of variation and test-retest variability for the mean retinal nerve fiber layer thickness were respectively: 0.94, 2.56% and 4.85 µm for the normal group and 0.93, 4.65% and 6.61 µm for the glaucomatous group. The intraclass correlation coefficient for retinal nerve fiber layer thickness in all quadrants were all excellent in both groups, with the superior quadrant having the highest ICCs (0.964 in glaucomatous eyes and nasal quadrant measurements having the lowest (0.800, but still excellent in eyes without glaucoma. The coefficient of variation was between 2.56% - 8.74% and between 4.65% - 11.44% in normal and glaucomatous group respectively. The test-retest variability was between 4.85 µm and 11.51 µm in the normal group and between 6.61 µm and 14.24 µm in the glaucomatous group. The measurements in glaucomatous eyes were more variable than normal eyes. CONCLUSIONS: Spectral domain optical coherence tomography showed excellent reproducibility with regard to retinal nerve fiber layer thickness measurements in normal and glaucomatous eyes.

  6. Wall thickness measurements of pipes in heat exchangers using ultrasonic waves

    International Nuclear Information System (INIS)

    Heat exchangers and reactors used in the chemical industry for heat exchange and conversion are exposed to the influence of corrosion and wear. These defect parts must be identified during operation in order to prevent damage occurring to the plant and to restrict break-down times. By means of manual ultrasonic wall thickness measurement worn parts in piping both on the inner and outer sides can be reliably detected in the assembled state. (orig.)

  7. Colonic wall thickness measured by ultrasound: striking differences in patients with cystic fibrosis versus healthy controls.

    OpenAIRE

    Haber, H P; Benda, N; Fitzke, G; Lang, A.; Langenberg, M; Riethmüller, J; Stern, M.

    1997-01-01

    BACKGROUND: Colonic strictures represent an advanced stage of fibrosing colonopathy in patients with cystic fibrosis. AIMS: To clarify whether ultrasonography can identify patients with an early stage of fibrosing colonopathy and to determine clinical factors that influence bowel wall thickening. PATIENTS: Ninety patients with cystic fibrosis, median age 10 years, and 46 healthy controls, median age 13 years, were investigated. METHODS: Bowel wall thickness was measured by ultrasound in a pro...

  8. Evaluation of Central Corneal Thickness Measurements by Optical Low Coherence Reflectometry and Contact Ultrasonic Pachymeter

    OpenAIRE

    Kocatürk, Tolga; Erkan, Erol; Çakmak, Harun; Kurt Ömürlü, İmran; Dayanır, Volkan

    2015-01-01

    AbstractObjective: The aim is to compare the central corneal thickness measurements by optical low-coherence reflectometry and contact ultrasonic pachymeter in patients with pseudoexfoliation syndrome, pseudoexfoliation glaucoma, primary open-angle glaucoma as well as healthy subjects.Materials and Methods: We have made a survey of the data of the patients with glaucoma who had been followed for ten years at the Department of Ophthalmology. 148 eyes of 76 patients who had central corneal thic...

  9. Central corneal thickness and anterior chamber depth measurement by Sirius® Scheimpflug tomography and ultrasound

    OpenAIRE

    Jorge J; Rosado JL; Díaz-Rey JA; González-Méijome JM

    2013-01-01

    J Jorge,1 JL Rosado,2 JA Díaz-Rey,1 JM González-Méijome11Clinical and Experimental Optometry Research Laboratory, Center of Physics (Optometry), School of Sciences, University of Minho, Braga, 2Opticlinic, Lisboa, PortugalBackground: The purpose of this study was to compare the accuracy of the new Sirius® Scheimpflug anterior segment examination device for measurement of central corneal thickness (CCT) and anterior chamber depth (ACD) with that of CCT ...

  10. Equations of bark thickness and volume profiles at different heights with easy-measurement variables

    OpenAIRE

    Cellini, Juan Manuel; Galarza, Martín; Burns, Sarah Lilian; Martínez Pastur, Guillermo; Lencinas, María Vanessa

    2012-01-01

    The objective of this work was to develop equations of thickness profile and bark volume at different heights with easy-measurement variables, taking as a study case Nothofagus pumilio forests, growing in different site qualities and growth phases in Southern Patagonia. Data was collected from 717 harvested trees. Three models were fitted using multiple, non-lineal regression and generalized linear model, by stepwise methodology, iteratively reweighted least squares method for maximum likelih...

  11. Carotid Artery Segmentation in Ultrasound Images and Measurement of Intima-Media Thickness

    OpenAIRE

    Vaishali Naik; R.S. Gamad; P.P. Bansod

    2013-01-01

    Background. The segmentation of the common carotid artery (CCA) wall is imperative for the determination of the intima-media thickness (IMT) on B-mode ultrasound (US) images. The IMT is considered an important indicator in the evaluation of the risk for the development of atherosclerosis. In this paper, authors have discussed the relevance of measurements in clinical practices and the challenges that one has to face while approaching the segmentation of carotid artery on ultrasound images. Th...

  12. Form, figure, and thickness measurement of freeform and conformal optics with non-contact sensors

    Science.gov (United States)

    DeFisher, Scott; Fess, Edward; Matthews, Greg

    2014-05-01

    Advancements in optical manufacturing technology allow optical designers to implement freeform and conformal shapes in their systems. Metrology of the shapes has traditionally been difficult, especially at the sub-micron level. Contact measuring systems typically lack the accuracy required for optical qualification and can damage the surface. Interferometric systems are unable to handle high spherical departures and may require complicated lateral calibration to generate feedback for deterministic grinding and polishing. OptiPro has developed UltraSurf, a noncontact coordinate measuring machine to determine the form, figure, and thickness of freeform and conformal optics. We integrated several non-contact sensors that acquire surface information through different optical principles. Each probe has strength and weaknesses relative to an optic's material properties, surface finish, and figure error. The measuring probe is scanned over the optical surface while maintaining perpendicularity and a constant focal offset. Measurements of freeform and conformal shapes will be presented. The scanning method of UltraSurf and the non-contact probes will also be shown. The form, figure, and thickness data will highlight the capabilities of UltraSurf to measure freeform surfaces. Comparisons between accuracy and measureable surface departure will be made with current metrology systems such as coordinate measuring machines, interferometers, and profilometers. Additionally, methods for defining a freeform or conformal surface for metrology analysis and manufacturing will be discussed.

  13. An Electrochemical Strategy to Measure the Thickness of Electroactive Microbial Biofilms

    Science.gov (United States)

    Millo, Diego

    2015-01-01

    The study of electroactive microbial biofilms often requires knowledge of the biofilm thickness. Unfortunately, this parameter is, nowadays, only accessible through expensive microscopic techniques. This work overcomes this limitation by presenting a new strategy, exploiting the use of chronoamperometry (CA) alone. A mixed-culture biofilm is exposed to an O2-saturated solution during anode respiration to suppress its catalytic activity. Assuming that inactivation of the electrocatalytic process is caused by O2 diffusion through the biofilm, a simple relation allows the use of the time constant extracted from the fitting of the curve of the CA trace during inactivation for the straightforward and quantitative determination of biofilm thickness. The biofilm thickness obtained with this method obeys the expected trend reported for biofilm growth and is in agreement with optical measurements. Contrary to the techniques usually employed to determine biofilm thickness, this new strategy is very rapid, nondisruptive, inexpensive, and may become a convenient alternative with respect to expensive and time-consuming microscopic techniques.

  14. Neutron diffraction measurements of residual stresses in a 50 mm thick weld

    International Nuclear Information System (INIS)

    Research highlights: → Determined residual stresses through the thickness of the 50 mm thick weld. → Two-dimensional mapping of the longitudinal stress. Observed significant stresses along the heat-affected zone. → Measured the maximum stress of 460 MPa at 40 mm below from the top surface. - Abstract: Residual stresses were determined through the thickness of a 50 mm thick ferrite steel weld plate using neutron diffraction. Whereas the limiting penetration depth for iron-based alloys is about 25 mm in the most typical neutron diffractometers, we significantly enhanced the penetration depth up to 50 mm with 2 mm spatial resolution by using the neutron wavelength of 2.39 A. The selected wavelength minimizes the total neutron cross-section and beam attenuation, thereby, maximizes the neutron fluxes at depth. Two-dimensional mapping of the residual stresses shows that significant amounts of the tensile longitudinal stresses (over 90% of yield strength) were developed along the heat-affected zone of the weld.

  15. Development of a non-invasive LED based device for adipose tissue thickness measurements in vivo

    Science.gov (United States)

    Volceka, K.; Jakovels, D.; Arina, Z.; Zaharans, J.; Kviesis, E.; Strode, A.; Svampe, E.; Ozolina-Moll, L.; Butnere, M. M.

    2012-06-01

    There are a number of techniques for body composition assessment in clinics and in field-surveys, but in all cases the applied methods have advantages and disadvantages. High precision imaging methods are available, though expensive and non-portable, however, the methods devised for the mass population, often suffer from the lack of precision. Therefore, the development of a safe, mobile, non-invasive, optical method that would be easy to perform, precise and low-cost, but also would offer an accurate assessment of subcutaneous adipose tissue (SAT) both in lean and in obese persons is required. Thereof, the diffuse optical spectroscopy is advantageous over the aforementioned techniques. A prototype device using an optical method for measurement of the SAT thickness in vivo has been developed. The probe contained multiple LEDs (660nm) distributed at various distances from the photo-detector which allow different light penetration depths into the subcutaneous tissue. The differences of the reflected light intensities were used to create a non-linear model, and the computed values were compared with the corresponding thicknesses of SAT, assessed by B-mode ultrasonography. The results show that with the optical system used in this study, accurate results of different SAT thicknesses can be obtained, and imply a further potential for development of multispectral optical system to observe changes of SAT thickness as well as to determine the percentage of total body fat.

  16. A portable gamma backscatter gauge for measurement of wall thickness of pipes and boilers

    International Nuclear Information System (INIS)

    A portable instrument for 'in situ' measurement of wall thickness of boilers and tubes, working on the principle of gamma back-scattering, and using a low activity gamma source (30 micro-curies Co60) and a scintillation detector is described. The probe consists of a gamma source and an NaI(tl) scintillation detector coupled to a multiplier phototube. The EHT circuit for the PM tube and the preamplifier are also incorporated inside the probe. The probe is coupled to a measuring part consisting of an amplifier for amplifying the pulses from the probe, a single channel analyser which is set to select pulses corresponding to energy of backscattered gammas and a count-rate meter to count the number of pulses. With prior calibration, count-rate can be correlated to the thickness of the backscatter eg. boiler wall or tube wall. The instrument can measure wall thicknesses upto 2 cm of steel with an accuracy of +- 10%. The unit can also be used for detection of erosion and blocking in pipes carrying process materials. The electronic circuitry is fully transistorised and works on readily available flashlight cells. The complete system is portable and well suited for field use. (author)

  17. 42 CFR 410.31 - Bone mass measurement: Conditions for coverage and frequency standards.

    Science.gov (United States)

    2010-10-01

    ... by the FDA under 21 CFR part 807, or approved for marketing by the FDA for this use under 21 CFR part... 42 Public Health 2 2010-10-01 2010-10-01 false Bone mass measurement: Conditions for coverage and... Medical and Other Health Services § 410.31 Bone mass measurement: Conditions for coverage and...

  18. Normal SUV Values Measured from NaF18- PET/CT Bone Scan Studies

    OpenAIRE

    Aung Zaw Win; Carina Mari Aparici

    2014-01-01

    Objectives Cancer and metabolic bone diseases can alter the SUV. SUV values have never been measured from healthy skeletons in NaF18-PET/CT bone scans. The primary aim of this study was to measure the SUV values from normal skeletons in NaF18-PET/CT bone scans. Methods A retrospective study was carried out involving NaF18- PET/CT bone scans that were done at our institution between January 2010 to May 2012. Our excluding criteria was patients with abnormal real function and patients with past...

  19. Reliability of fetal nasal bone length measurement at 11–14 weeks of gestation

    Directory of Open Access Journals (Sweden)

    Suwanrath Chitkasaem

    2013-01-01

    Full Text Available Abstract Background Nasal bone assessment has been incorporated into Down syndrome screening in first trimester. Several studies have established the normal reference values for fetal nasal bone length in the first trimester, which were found to be varied by population. However, the study on reliability of nasal bone length measurement was limited with contradictory results. This study aimed to investigate the reliability of fetal nasal bone length measurement at 11–14 weeks of gestation in the Thai population. Methods A total of 111 pregnant women at 11–14 weeks of gestation attending for the routine first-trimester ultrasound examination were recruited. Each case was measured separately by two examiners. Examiner 1 performed the first measurement in all cases; any of the other 5 examiners consecutively performed the second measurement. Three independent measurements were performed by each examiner and they were blinded to the results of the others. Intraobserver and interobserver variabilities were evaluated with the intraclass correlation coefficient (ICC. Results Nasal bone measurement was successfully performed in 106/111 cases (95.5% by at least one examiner; 89 cases were performed by two examiners. The intraobserver variability was excellent for all examiners (ICC, 0.840-0.939. The interobserver variability between different pairs of examiners varied from moderate to excellent (ICC, 0.467-0.962. The interobserver variability between examiner 1 and any other examiner was good (ICC, 0.749. The Bland-Altman plot of the interobserver differences of nasal bone length measurements between examiner 1 and any other examiner showed good agreement. Conclusions The reliability of the fetal nasal bone length measurement at 11–14 weeks of gestation was good. The nasal bone length measurement was reproducible. Ethnicity has an effect on fetal nasal bone length, but reliability of nasal bone length measurement is critical to accuracy of

  20. Comparison of central corneal thickness measurements between anterior chamber-optical coherence tomography and ultrasonic pachymeter

    International Nuclear Information System (INIS)

    Objective: To assess the agreement of central corneal thickness (CCT) measured by anterior chamber-optical coherence tomography (AC-OCT) and ultrasonic pachymeter and provide an objective basis for clinical application of AC-OCT. Methods: CCT of 150 college student volunteers (300 eyes) measured by two devices were obtained. The data was analyzed by paired t test and Pearson correlation analysis. Bland-Altman plot and Mountain plot were used to assess the agreement. Results: The mean CCT values were (530.05 ± 33.611) μm measured by AC-OCT and (543.68 ± 35.088) μm measured by ultrasonic pachymeter. Regression analysis showed a high correlation between the values obtained by both devices (r=0.960, P<0.001). Compared with AC-OCT, ultrasonic pachymeter overestimated the CCT by a mean of 13.62 μm. The two modalities had incomparable results. Conclusion: It is important to be noted in clinical practice that the measurements acquired by these two modalities are not directly interchangeable. However, the CCT measurements by the AC-OCT and ultrasonic pachymeter are highly correlated. AC-OCT is an effective method to observe the changes of the corneal thickness in the long term. (authors)

  1. Ultrasonic thickness structural health monitoring photoelastic visualization and measurement accuracy for internal pipe corrosion

    Science.gov (United States)

    Eason, Thomas J.; Bond, Leonard J.; Lozev, Mark G.

    2015-03-01

    Oil refinery production of fuels is becoming more challenging as a result of the changing world supply of crude oil towards properties of higher density, higher sulfur concentration, and higher acidity. One such production challenge is an increased risk of naphthenic acid corrosion that can result in various surface degradation profiles of uniform corrosion, non-uniform corrosion, and localized pitting in piping systems at temperatures between 150°C and 400°C. The irregular internal surface topology and high external surface temperature leads to a challenging in-service monitoring application for accurate pipe wall thickness measurements. Improved measurement technology is needed to continuously profile the local minimum thickness points of a non-uniformly corroding surface. The measurement accuracy and precision must be sufficient to provide a better understanding of the integrity risk associated with refining crude oils of higher acid concentration. This paper discusses potential technologies for measuring localized internal corrosion in high temperature steel piping and describes the approach under investigation to apply flexible ultrasonic thin-film piezoelectric transducer arrays fabricated by the sol-gel manufacturing process. Next, the elastic wave beam profile of a sol-gel transducer is characterized via photoelastic visualization. Finally, the variables that impact measurement accuracy and precision are discussed and a maximum likelihood statistical method is presented and demonstrated to quantify the measurement accuracy and precision of various time-of-flight thickness calculation methods in an ideal environment. The statistical method results in confidence values analogous to the a90 and a90/95 terminology used in Probability-of-Detection (POD) assessments.

  2. Optical instrument for measurement of vaginal coating thickness by drug delivery formulations

    International Nuclear Information System (INIS)

    An optical device has been developed for imaging the human vaginal epithelial surfaces, and quantitatively measuring distributions of coating thickness of drug delivery formulations - such as gels - applied for prophylaxis, contraception or therapy. The device consists of a rigid endoscope contained within a 27-mm-diam hollow, polished-transparent polycarbonate tube (150 mm long) with a hemispherical cap. Illumination is from a xenon arc. The device is inserted into, and remains stationary within the vagina. A custom gearing mechanism moves the endoscope relative to the tube, so that it views epithelial surfaces immediately apposing its outer surface (i.e., 150 mm long by 360 deg. azimuthal angle). Thus, with the tube fixed relative to the vagina, the endoscope sites local regions at distinct and measurable locations that span the vaginal epithelium. The returning light path is split between a video camera and photomultiplier. Excitation and emission filters in the light path enable measurement of fluorescence of the sited region. Thus, the instrument captures video images simultaneously with photometric measurement of fluorescence of each video field [∼10 mm diameter; formulations are labeled with 0.1% w/w United States Pharmacoepia (USP) injectable sodium fluorescein]. Position, time and fluorescence measurements are continuously displayed (on video) and recorded (to a computer database). The photomultiplier output is digitized to quantify fluorescence of the endoscope field of view. Quantification of the thickness of formulation coating of a surface sited by the device is achieved due to the linear relationship between thickness and fluorescence intensity for biologically relevant thin layers (of the order of 0.5 mm). Summary measures of coating have been developed, focusing upon extent, location and uniformity. The device has begun to be applied in human studies of model formulations for prophylaxis against infection with HIV and other sexually transmitted

  3. Bone metabolic activity in hyperostosis cranialis interna measured with {sup 18}F-fluoride PET

    Energy Technology Data Exchange (ETDEWEB)

    Waterval, Jerome J.; Dongen, Thijs M.A. van; Stokroos, Robert J.; Manni, Johannes J. [Maastricht University Medical Center, Department of Otorhinolaryngology and Head and Neck Surgery, Maastricht (Netherlands); Teule, Jaap G.J.; Kemerink, Gerrit J.; Brans, Boudewijn [Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Nieman, Fred H.M. [Maastricht University Medical Center, Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht (Netherlands)

    2011-05-15

    {sup 18}F-Fluoride PET/CT is a relatively undervalued diagnostic test to measure bone metabolism in bone diseases. Hyperostosis cranialis interna (HCI) is a (hereditary) bone disease characterised by endosteal hyperostosis and osteosclerosis of the skull and the skull base. Bone overgrowth causes entrapment and dysfunction of several cranial nerves. The aim of this study is to compare standardised uptake values (SUVs) at different sites in order to quantify bone metabolism in the affected anatomical regions in HCI patients. Nine affected family members, seven non-affected family members and nine non-HCI non-family members underwent {sup 18}F-fluoride PET/CT scans. SUVs were systematically measured in the different regions of interest: frontal bone, sphenoid bone, petrous bone and clivus. Moreover, the average {sup 18}F-fluoride uptake in the entire skull was measured by assessing the uptake in axial slides. Visual assessment of the PET scans of affected individuals was performed to discover the process of disturbed bone metabolism in HCI. {sup 18}F-Fluoride uptake is statistically significantly higher in the sphenoid bone and clivus regions of affected family members. Visual assessment of the scans of HCI patients is relevant in detecting disease severity and the pattern of disturbed bone metabolism throughout life. {sup 18}F-Fluoride PET/CT is useful in quantifying the metabolic activity in HCI and provides information about the process of disturbed bone metabolism in this specific disorder. Limitations are a narrow window between normal and pathological activity and the influence of age. This study emphasises that {sup 18}F-fluoride PET/CT may also be a promising diagnostic tool for other metabolic bone disorders, even those with an indolent course. (orig.)

  4. Bone metabolic activity in hyperostosis cranialis interna measured with 18F-fluoride PET

    International Nuclear Information System (INIS)

    18F-Fluoride PET/CT is a relatively undervalued diagnostic test to measure bone metabolism in bone diseases. Hyperostosis cranialis interna (HCI) is a (hereditary) bone disease characterised by endosteal hyperostosis and osteosclerosis of the skull and the skull base. Bone overgrowth causes entrapment and dysfunction of several cranial nerves. The aim of this study is to compare standardised uptake values (SUVs) at different sites in order to quantify bone metabolism in the affected anatomical regions in HCI patients. Nine affected family members, seven non-affected family members and nine non-HCI non-family members underwent 18F-fluoride PET/CT scans. SUVs were systematically measured in the different regions of interest: frontal bone, sphenoid bone, petrous bone and clivus. Moreover, the average 18F-fluoride uptake in the entire skull was measured by assessing the uptake in axial slides. Visual assessment of the PET scans of affected individuals was performed to discover the process of disturbed bone metabolism in HCI. 18F-Fluoride uptake is statistically significantly higher in the sphenoid bone and clivus regions of affected family members. Visual assessment of the scans of HCI patients is relevant in detecting disease severity and the pattern of disturbed bone metabolism throughout life. 18F-Fluoride PET/CT is useful in quantifying the metabolic activity in HCI and provides information about the process of disturbed bone metabolism in this specific disorder. Limitations are a narrow window between normal and pathological activity and the influence of age. This study emphasises that 18F-fluoride PET/CT may also be a promising diagnostic tool for other metabolic bone disorders, even those with an indolent course. (orig.)

  5. Ultrasonic estimates of fat thickness, C measurement and longissimus dorsi depth in rasa aragonesa ewes with same body condition score

    OpenAIRE

    Delfa, R.; Teixeira, A.; Blasco, I.; COLOMER-ROCHER, F.

    1991-01-01

    Ultrasonic estimates of fat thickness, C measurement and longissimus dorsi depth were assessed in 14 Rasa Aragonesa ewes with same body condition score. The ultrasonic estimates have been used for predicting tota1 carcass fat and muscle. The 76% of the variation in carcass lumbar fat thickness was accounted for by variation in lumbar fat thickness assessed by ultrasonic machine, whereas 53% of the variation in C measurement was accounted. Nevertheless only 5% of variation in m. Longissi...

  6. Wall thickness measurements of tubes by Internal Rotary Inspection System (IRIS)- a comparative study with metallography

    International Nuclear Information System (INIS)

    Internal Rotary Inspection System (IRIS) is a relatively new ultrasonic system of heat exchanger/ steam condenser tubes and pipelines for measurement of wall thinning and pitting due to corrosion. The wall thickness measurements made during a scan around the circumference of the tube are displayed as a stationary rectilinear display of circumferential cross section (Bscan) of the tube. The paper describes the results obtained on tubes of various materials used in process industries having corrosion on inner and outer surfaces of the tube. (author)

  7. Evaluation of Statistical Reliability on Ultrasonic Thickness Measurement Results by Round Robin Test

    International Nuclear Information System (INIS)

    Wall thinning of carbon steel pipe components due to Flow-Accelerated Corrosion (FAC) is one of the most serious problems to the integrity of steam cycle piping system in Nuclear Power Plants (NPP). For this reason, wall thinning by FAC has been inspected in secondary side piping systems in NPPs. The objective of this research is to verify confidence of wall thinning measurement system by conducting Roun Robin Test (RRT). 12 inspectors from 3 companies participated and, 23 specimens by size and shape were used according to standard practice in RRT From this RRT results, confidence intervals of thickness measurement system were obtained

  8. Measurement of neutron yield and angular distribution for thick natLi(p,n+x) reaction

    International Nuclear Information System (INIS)

    The low energy accelerators have been used to produce intense neutron flux for various applications employing lower threshold reactions involving light targets. Among those p+7Li, 9Be, 13C, D+D,T are the popular ones. In the present work the total neutron yield has been measured for thick Lithium target up to 5.5 proton energy using BF3 counter. Angular distribution of the neutrons at 4.5 and 5.5 MeV also measured to investigate the feasibility of a neutron time of flight facility at FOTIA

  9. Water-side oxide layer thickness measurement of the irradiated PWR fuel rod by ECT method

    International Nuclear Information System (INIS)

    It has been known that water-side corrosion of fuel rods in nuclear reactor is accompanied with the metallic loss of wall thickness and hydrogen pickup in the fuel cladding tube. The fuel clad corrosion is one of the major factors to be controlled to maintain the fuel integrity during reactor operation. An oxide layer thickness measuring device equipped with ECT probe system was developed by KAERI, and whose performance test was carried out in NDT(Non-Destructive Test) hot-cell of PIE(Post Irradiation Examination) Facility. At first, the calibration/performance test was executed for the unirradiated standard specimen rod fabricated with several kinds of plastic thin films whose thickness were predetermined, and the result of which showed a good precision within 10% of discrepancy. And then, hot test was performed for the irradiated fuel rod selectively extracted from J44 fuel assembly discharged from Kori Unit-2. The data obtained with this device were compared with the metallographic results obtained from destructive examination in PIEF hot-cell on the same fuel rod to verify the validity of the measurement data. (author)

  10. Thickness measurement approach for plasma sprayed coatings using ultrasonic testing technique

    Institute of Scientific and Technical Information of China (English)

    LIN Li; LI Xi-meng; XU Zhi-hui; LEI Ming-kai

    2004-01-01

    The special ultrasonic testing system has been developed for thickness measurement of plasma sprayed coatings. The ultrasonic immersion method was used to obtain stable coupling condition and avoid other disadvantages of contact method. Spherical acoustic lens were designed to focus ultrasonic beam so as to improve beam directivity and concentrate ultrasonic energy. To increase testing precision and avoid mussy wave signals, moderate pulse width and frequency of the transducer has been selected. The displacement of transducer in X-Y-Z directions was precisely manipulated by step-controlled system to insure the accuracy of focus length and repetition of measurement. Optimized testing conditions (with the transducer of center frequency of 10 MHz and crystal diameter of 8 mm, focus length of 9.5 mm, diameter of focal column of 0. 1 mm and length of focal column of 0.27 mm) were selected to determine the thickness between 285 -414 μm of ZrO2 coatings plasma sprayed on the nickel based superalloy. The frequency interval of the periodic extremums in ultrasonic power spectra decreases with increasing coating thickness. The ultrasonic results accord with those of metallographical method.

  11. Equations of bark thickness and volume profiles at different heights with easy-measurement variables

    Energy Technology Data Exchange (ETDEWEB)

    Cellini, J. M.; Galarza, M.; Burns, S. L.; Martinez-Pastur, G. J.; Lencinas, M. V.

    2012-11-01

    The objective of this work was to develop equations of thickness profile and bark volume at different heights with easy-measurement variables, taking as a study case Nothofagus pumilio forests, growing in different site qualities and growth phases in Southern Patagonia. Data was collected from 717 harvested trees. Three models were fitted using multiple, non-lineal regression and generalized linear model, by stepwise methodology, iteratively reweighted least squares method for maximum likelihood estimation and Marquardt algorithm. The dependent variables were diameter at 1.30 m height (DBH), relative height (RH) and growth phase (GP). The statistic evaluation was made through the adjusted determinant coefficient (r2-adj), standard error of the estimation (SEE), mean absolute error and residual analysis. All models presented good fitness with a significant correlation with the growth phase. A decrease in the thickness was observed when the relative height increase. Moreover, a bark coefficient was made to calculate volume with and without bark of individual trees, where significant differences according to site quality of the stands and DBH class of the trees were observed. It can be concluded that the prediction of bark thickness and bark coefficient is possible using DBH, height, site quality and growth phase, common and easy measurement variables used in forest inventories. (Author) 23 refs.

  12. A comparative investigation of thickness measurements of ultra-thin water films by scanning probe techniques

    International Nuclear Information System (INIS)

    The reliable operation of micro- and nanomechanical devices necessitates a precise knowledge of the water film thickness present on the surfaces of these devices with accuracy in the nanometer range. In this work, the thickness of an ultra-thin water film was measured by distance tunneling spectroscopy and distance dynamic force spectroscopy during desorption in an ultra-high vacuum system, from about 2.5 nm up to complete desorption at 10-8 mbar. The tunneling current and the amplitude of vibration and the normal force were detected as a function of the probe-sample distance. In these experiments, a direct comparison of both methods was possible. It was determined that dynamic force spectroscopy provides the most accurate values. The previously reported tunneling spectroscopy, which requires the application of significantly high voltages generally leads to values that are 25 times higher than values determined by dynamic force spectroscopy

  13. Value of endometrial thickness measurement for diagnosing focal intrauterine pathology in women without abnormal uterine bleeding

    DEFF Research Database (Denmark)

    Dreisler, E; Sorensen, S Stampe; Ibsen, P H;

    2009-01-01

    performed when focal intrauterine pathology was suspected at SCSH. We excluded women with AUB (n = 237), failure of SCSH (n = 50), a scan that was not in the follicular phase (n = 11), hysteroscopy contraindicated (n = 2), and users of sequential hormone therapy (n = 9) or selective estrogen receptor......OBJECTIVE: To assess the diagnostic value of transvaginal sonographic (TVS) measurement of endometrial thickness for diagnosing focal intrauterine pathology in women without abnormal uterine bleeding (AUB). METHODS: A random selection from the Danish Civil Registration System was made: 1660 women...... modulators (n = 2). Thus, 375 women without AUB were included (217 pre- and 158 postmenopausal). Receiver-operating characteristics (ROC) curves for endometrial thickness and focal lesion were analyzed. RESULTS: Focal intrauterine pathology was confirmed in 41 women (35 with polyps, five with submucosal...

  14. Measurement of oil film thickness for application to elastomeric Stirling engine rod seals

    Science.gov (United States)

    Krauter, A. I.

    1981-01-01

    The rod seal in the Stirling engine has the function of separating high pressure gas from low or ambient pressure oil. An experimental apparatus was designed to measure the oil film thickness distribution for an elastomeric seal in a reciprocating application. Tests were conducted on commercial elastomeric seals having a 76 mm rod and a 3.8 mm axial width. Test conditions included 70 and 90 seal durometers, a sliding velocity of 0.8 m/sec, and a zero pressure gradient across the seal. An acrylic cylinder and a typical synthetic base automotive lubricant were used. The experimental results showed that the effect of seal hardness on the oil film thickness is considerable. A comparison between analytical and experimental oil film profiles for an elastomeric seal during relatively high speed reciprocating motion showed an overall qualitative agreement.

  15. Measurement of thickness of thin films by the X-ray diffraction method

    International Nuclear Information System (INIS)

    X-ray diffraction method can be used to measure the thickness of thin films (coatings). The principle and the experimental details of the x-ray diffraction methods are described. The intensities of the diffracted beams are derived assuming a random orientation of the crystallites in the diffracting medium. Consequently, the expressions are not valid when the sample has preferred orientation. To check the performance of the method, thicknesses of nickel deposits on mild steel plates were determined by the x-ray diffraction method and the results compared with those obtained by the weighing method and metallographic examination. The weighing method which gives an accuracy of +- 0.1 micron is taken as the standard. The x-ray diffraction methods and the metallographic examinations give values within +- 1 micron of the value obtained by the weighing method. (author)

  16. Choroidal thickness changes after dynamic exercise as measured by spectral-domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Nihat Sayin

    2015-01-01

    Full Text Available Purpose: To measure the choroidal thickness (CT after dynamic exercise by using enhanced depth imaging optical coherence tomography (EDI-OCT. Materials and Methods: A total of 19 healthy participants performed 10 min of low-impact, moderate-intensity exercise (i.e., riding a bicycle ergometer and were examined with EDI-OCT. Each participant was scanned before exercise and afterward at 5 min and 15 min. CT measurement was taken at the fovea and 1000 μ away from the fovea in the nasal, temporal, superior, and inferior regions. Retinal thickness, intraocular pressure, ocular perfusion pressure (OPP, heart rate, and mean blood pressure (mBP were also measured. Results: A significant increase occurred in OPP and mBP at 5 min and 15 min following exercise (P ˂ 0.05. The mean subfoveal CT at baseline was 344.00 ± 64.71 μm compared to 370.63 ± 66.87 μm at 5 min and 345.31 ± 63.58 μm at 15 min after exercise. CT measurements at all locations significantly increased at 5 min following exercise compared to the baseline (P ˂ 0.001, while measurements at 15 min following exercise did not significant differ compared to the baseline (P ˃ 0.05. There was no significant difference in retinal thickness at any location before and at 5 min and 15 min following exercise (P ˃ 0.05. Conclusion: Findings revealed that dynamic exercise causes a significant increase in CT for at least 5 min following exercise.

  17. Development of liquid film thickness measurement technique by high-density multipoint electrodes method

    International Nuclear Information System (INIS)

    High-density multipoint electrode method was developed to measure a liquid film thickness transient on a curved surface. The devised method allows us to measure spatial distribution of liquid film with its conductance between electrodes. The sensor was designed and fabricated as a multilayer print circuit board, where electrode pairs were distributed in reticular pattern with narrow interval. In order to measure a lot of electrode pairs at a high sampling rate, signal-processing method used by the wire mesh sensor measurement system was applied. An electrochemical impedance spectrometry concludes that the sampling rate of 1000 slices/s is feasible without signal distortion by electric double layer. The method was validated with two experimental campaigns: (1) a droplet impingement on a flat film and (2) a jet impingement on a rod-shape sensor surface. In the former experiment, a water droplet having 4 mm in diameter impinged onto the 1 mm thick film layer. A visual observation study with high-speed video camera shows after the liquid impingement, the water layer thinning process was clearly demonstrated with the sensor. For the latter experiment, the flexible circuit board was bended to form a cylindrical shape to measure water film on a simulated fuel rod in bundle geometry. A water jet having 3 mm in diameter impinged onto the rod-shape sensor surface. The process of wetting area enlargement on the rod surface was demonstrated in the same manner that the video-frames showed. (author)

  18. Microindentation for In Vivo Measurement of Bone Tissue Mechanical Properties in Humans

    OpenAIRE

    Diez-Perez, Adolfo; Güerri, Roberto; Nogues, Xavier; Cáceres, Enric; Peña, Maria Jesus; Mellibovsky, Leonardo; Randall, Connor; Bridges, Daniel; Weaver, James C.; Proctor, Alexander; Brimer, Davis; Koester, Kurt J.; Ritchie, Robert O.; Hansma, Paul K.

    2010-01-01

    Bone tissue mechanical properties are deemed a key component of bone strength, but their assessment requires invasive procedures. Here we validate a new instrument, a reference point indentation (RPI) instrument, for measuring these tissue properties in vivo. The RPI instrument performs bone microindentation testing (BMT) by inserting a probe assembly through the skin covering the tibia and, after displacing periosteum, applying 20 indentation cycles at 2 Hz each with a maximum force of 11 N....

  19. A Novel Portable Apparatus for Noninvasively Measuring Bone Density Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The bone loss associated with extended space missions in astronaut represents a serious health threat, both over the flight period and upon returning to...

  20. Bone mineral content measurement in small infants by single-photon absorptiometry: current methodologic issues

    International Nuclear Information System (INIS)

    Single-photon absorptiometry (SPA), developed in 1963 and adapted for infants by Steichen et al. in 1976, is an important tool to quantitate bone mineralization in infants. Studies of infants in which SPA was used include studies of fetal bone mineralization and postnatal bone mineralization in very low birth weight infants. The SPA technique has also been used as a research tool to investigate longitudinal bone mineralization and to study the effect of nutrition and disease processes such as rickets or osteopenia of prematurity. At present, it has little direct clinical application for diagnosing bone disease in single patients. The bones most often used to measure bone mineral content (BMC) are the radius, the ulna, and, less often, the humerus. The radius appears to be preferred as a suitable bone to measure BMC in infants. It is easily accessible; anatomic reference points are easily palpated and have a constant relationship to the radial mid-shaft site; soft tissue does not affect either palpation of anatomic reference points or BMC quantitation in vivo. The peripheral location of the radius minimizes body radiation exposure. Trabecular and cortical bone can be measured separately. Extensive background studies exist on radial BMC in small infants. Most important, the radius has a relatively long zone of constant BMC. Finally, SPA for BMC in the radius has a high degree of precision and accuracy. 61 references

  1. Prognostic Indicators of Changes in Bone Density Measures in Adolescent Girls with Anorexia Nervosa-II

    Science.gov (United States)

    Misra, Madhusmita; Prabhakaran, Rajani; Miller, Karen K.; Goldstein, Mark A.; Mickley, Diane; Clauss, Laura; Lockhart, Patrice; Cord, Jennalee; Herzog, David B.; Katzman, Debra K.; Klibanski, Anne

    2008-01-01

    Introduction: Adolescents with anorexia nervosa (AN) have low bone mineral density (BMD). Baseline predictors of temporal BMD changes (ΔBMD) in AN, including 1) gastrointestinal peptides regulating food intake and appetite that have been related to bone metabolism and 2) bone turnover markers, have not been well characterized. We hypothesized that baseline levels of nutritionally regulated hormones and of bone turnover markers would predict ΔBMD overall. Methods: In a prospective observational study, lumbar and whole-body BMD was measured at 0, 6, and 12 months in 34 AN girls aged 12–18 yr and 33 controls. Baseline body mass index, lean mass, nutritionally regulated hormones [IGF-I, cortisol, ghrelin, leptin, and peptide YY (PYY)], bone formation, and resorption markers were examined to determine nutritional and hormonal predictors of bone density changes. Results: In a regression model, baseline ghrelin and PYY predicted changes in spine bone measures; and baseline ghrelin, cortisol, and PYY predicted changes in whole-body bone measures independent of baseline nutritional status. Conclusions: Neuroendocrine gastrointestinal-derived peptides regulating food intake are independent predictors of changes in bone mass in AN. PMID:18089697

  2. Automatic thickness measuring system of zirconium and zircaloy-2 layers of zirconium liner cladding tubes for boiling water reactor

    International Nuclear Information System (INIS)

    An automatic measuring system using ultrasonic method and electromagnetic method has been developed to measure the thickness of zirconium and zircaloy-2 layers. The sophisticated mechanism and the unique signal processing for suppression of several types of error enable high accurate measurement. The standard deviation of the liner thickness measurement is 2.2 μm and that of mother layer measurement is 3.0 μm. This system is very useful to assure the thickness of each layer and to produce high quality zirconium liner cladding tubes. (author)

  3. Spatio-temporal variability of satellite derived aerosol optical thickness and ground measurements over East China

    Science.gov (United States)

    Meng, Fei; Shi, Tongguang

    2016-04-01

    Two-year records of Visible Infrared Imaging Radiometer Suite (VIIRS) Intermediate Product (IP) data on the aerosol optical thickness (AOT) at 550 nm were evaluated by comparing them with sun-sky radiometer measurements from the Chinese sun hazemeter network (CSHNET) and the aerosol robotic network (AERONET). The monthly and seasonal variations in the aerosol optical properties over eastern China were then investigated using collocated VIIRS IP data and CSHNET and AERONET measurements.Results show that the performances of the current VIIRS IP AOT retrievals at the provisional stage were consistent with ground measurements. Similar characteristics of seasonal and monthly variations were found among the measurements, though the observational methodologies were different, showing maxima in the summer and spring and minima in the winter and autumn.

  4. Phantom studies of triple photon absorptiometry and bone mineral measurement at a hip prosthesis

    International Nuclear Information System (INIS)

    The feasibility of using triple photon absorptiometry (TPA) for the measurement of bone mineral mass about a hip prosthesis was examined. A theoretical expression describing the variance of TPA measurements was verified using a triple photon source and phantom materials which simulate the soft tissue-bone mineral-metal prosthesis system. The expression for the variance was used to determine an optimized set of photon energies. It was shown that a precision of 3% could be obtained for reasonable measurement times using this optimized set of energies and that TPA should be a feasible approach for measurement of bone mineral about a hip prosthesis. (orig.)

  5. 老年肱骨近端骨折患者皮质骨厚度与骨密度相关性分析%Analysis of the association between proximal humeral cortical bone thickness and bone mineral ;density in elderly proximal humeral fracture patients

    Institute of Scientific and Technical Information of China (English)

    张玺; 胡永成; 耿欣; 陈菲; 李健

    2015-01-01

    Objective To explore the possible association between proximal humeral cortical bone thickness and bone mineral density (BMD) in elderly patients with proximal humeral fractures. Methods We scaned 69 cases of the shoulders in elderly proximal humeral fracture patients and measured the average cortical bone thickness in two different CT layers with picture archiving and communication system (PACS). BMD was measured with dual-energy x-ray absorptiometry (DXA). Spearman correlations were used to assess the relationship between cortical bone thickness and BMD of femoral neck and lumbar vertebra. Results The study group was consisted of 69 cases, including 18 males and 51 females. About 65% of female and 16% of male were complicated by osteoporosis, The BMD of lumber and femoral neck were better in male patients than female patients (P<0.05), and in male osteoporosis patients than female osteoprosis patients (P<0.05). The BMD of lumber and femoral neck in all patients were closely related to average cortical bone thickness, and the same result was found in osteoporosis patients. Conclusion The measurement technique of average cortical bone thickness with CT and PACS is a quick and accurate method, which complements for DXA.%目的探讨老年肱骨近端骨折患者肱骨近端骨皮质厚度与骨密度(bone mineral density,BMD)的相关性。方法使用螺旋CT机对69例老年肱骨近端骨折患者的肩关节进行扫描后在图像工作站影像归档和通信系统处理软件中对两个水平层面图像的皮质骨厚度进行测量并取平均数,BMD值使用双能X线BMD测量仪测量获得,采用Spearman等级相关分析方法对腰椎和股骨颈处BMD与平均皮质骨厚度相关性进行计算。结果69例患者中,男18例、女51例,女性骨质疏松者占全部病例的65%,男性骨质疏松者占全部病例的16%。男性患者腰椎、股骨颈处BMD和平均皮质骨厚度均优于女性(P<0.05),骨质疏松患者

  6. The measurement of conductivity of copper indium disulphide thin films against temperature and thickness

    International Nuclear Information System (INIS)

    Ternary semiconductor copper indium disulphide (CuInS sub 2) thin films have been prepared by thermal evaporation. Three stacked layers of film starting with copper, indium and finally sulphur was deposited on glass substrate in the thickness ratio of 1: 1: I0. The films were then annealed in carbon block by method known as encapsulated sulphurization at 350 degree C for 4 hours. The XRD analysis for four samples of thickness of 449.5, 586, 612 and 654 nm showed that stoichiometric CuInS sub 2, were formed at this annealing condition. The electrical conductivity of CuInS sub 2 thin films were measured against temperature from 150K to 300K. The conductivity values were between 76.6 Sm sup -1 to 631.26 Sm sup -1 and the result showed that it increase exponentially with temperature for the above temperature range. The resulting activation energies were found to be in the range 0.05 to 0.08 eV. This suggested that hopping mechanism predominant to the conducting process. It also found that the conductivity decreased with increasing film thickness

  7. Determination of the optical thickness and effective particle radius of clouds from transmitted solar radiation measurements

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A method is presented for determining the optical thickness (τc) and effective particle radius (γe) of stratiform cloud layers from transmitted solar radiation measurements. A detailed study shows that the cloud optical thickness and effective particle radius of water clouds can be determined from transmission function rneasurements at 0.75 and 2.13 μm, provided that the scaled optical thickness τ'0.75 >1 and γe>5 μm. The wavelengths adopted by our study are similar to the channels of the moderate resolution imaging spectrometer (MODIS). The proposed method is invalid for optically thin clouds since transmission at 2.13 μm is less sensitive to γe. The retrieval errors of τ'γ.75 and γe monotonically decrease with increasing τc. For clouds having τ'0.75≥2, the retrieval errors of τ'0.75 and γe are below 10 % and 20 %, respectively. Transmissions at 0.75 and 1.65 μm can also be used to retrieve τc and γe.

  8. Measurement of torsion angles of long finger bones using computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Berthold, L.D. [Dept. of Pediatric Radiology, Justus Liebig Univ., Giessen (Germany); Univ. of Giessen (Germany). Dept. of Pediatric Radiology; Peter, A. [Dept. of Traumatology, Philipps Univ. Marburg (Germany); Ishaque, N.; Mauermann, F.; Klose, K.J. [Dept. of Diagnostic Radiology, Philipps Univ. Marburg (Germany); Boehringer, G. [Dept. of Traumatology, Justus Liebig Univ., Giessen (Germany)

    2001-10-01

    Objective: Rotational dislocation at the fracture site is a complication of long finger bone fractures of the metacarpals and phalanges. To evaluate such deformities, we performed CT of the articular surfaces of these bones to demonstrate the torsion angles. Design: We evaluated 10 pairs of cadaver hands. These were placed flat, with the bones of interest perpendicular to the gantry to acquire axial images. The torsion of the long bone axes was defined as the angle between a tangent positioned parallel to the proximal articular surface and a tangent parallel to the distal articular surface of individual bones. Results: The maximum difference between repeated measurements was 4 . Intraobserver differences measured between right and left hands are less than 3 . Conclusion: Side differences in torsion angles exceeding 3 are strongly suspicious of a malrotation after fracture. These measurements might help to plan derotational osteotomy and assess the results of therapy. (orig.)

  9. Study on the relationship between the thickness of the anterior cruciate ligament, anthropometric data and anatomical measurements on the knee☆

    Science.gov (United States)

    de Oliveira, Victor Marques; Latorre, Gabriel Carmona; Netto, Alfredo dos Santos; Jorge, Rafael Baches; Filho, Guinel Hernandez; de Paula Leite Cury, Ricardo

    2016-01-01

    Objectives To ascertain thickness measurements on the anterior cruciate ligament (ACL) in its middle third on magnetic resonance imaging (MRI) scans and to assess whether there is any association between variations in ligament thickness and patients’ heights and ages, along with variations in the anatomical measurements on the knee. Methods MRI scans on 48 knees were evaluated. The anteroposterior size of the femoral condyles, interepicondylar distance, intercondylar distance and anteroposterior and mediolateral thicknesses of the ACL were measured. It was assessed whether there was any statistical relationship between ACL thickness and the patients’ age, height or other measurements evaluated. Results The mean thickness of the middle third of the ACL was 4.5 mm in the sagittal plane and 4.3 mm in the frontal plane. The anteroposterior thickness of the ACL in its middle third had a positive relationship with the size of the lateral condyle. The mediolateral thickness of the ACL in its middle third had a positive relationship with the size of the lateral condyle and with the intercondylar distance in the axial plane. There was no relationship between the thickness of the ACL and the patients’ age or height. Conclusion The thickness of the ACL presented positive associations with the size of the lateral femoral condyle and the intercondylar distance. PMID:27069889

  10. Coating thickness measurements on gas-borne nanoparticles by combined mobility and aerodynamic spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Weis, Frederik, E-mail: frederik.weis@kit.edu; Seipenbusch, Martin; Kasper, Gerhard [Karlsruhe Institute of Technology, Institute for Mechanical Process Engineering and Mechanics (Germany)

    2015-01-15

    An on-line method is described and validated to measure the thickness of coatings on gas-borne nanoparticles. The method is essentially a tandem technique which measures the aerodynamic diameter of a particle twice—before and after coating—by a single-stage low-pressure impactor (SS-LPI) for the same mobility equivalent diameter preselected via differential mobility analyzer (DMA). A shell thickness is then derived from the change in effective particle density determined by the SS-LPI. The method requires a difference in mass density between carrier particle and coating material. Its theoretical sensitivity is shown to range between about 0.1 and 1 nm, depending on the density ratio. One advantage of this approach is that both DMA and SS-LPI are situated in series but downstream of the coating step, so as not to interfere with the coating process. The method was validated against transmission electron microscopy (TEM) measurements, using spherical silica–titania particles coated with conformal shells of molybdenum and bismuth oxide by chemical vapor deposition (CVD). For such spherical particles, the agreement with TEM was excellent. The technique was able to provide layer thicknesses for sub-nanometer layers barely or not resolved by TEM. The paper also discusses the impact of ‘non-ideal’ phenomena such as the formation of doublet particles by coagulation, the effect of multiply charged particles, or the onset of homogeneous decomposition of the coating precursor. With supporting experimental data, it is shown that such phenomena can be interpreted reliably from certain features of the impactor penetration curve. The on-line method can thus be used for fast screening of process parameters and reliable process monitoring for gas-phase synthesis of composite nanopowders.

  11. Thickness measurement of steel products with EMAT's (electromagnetic acoustic transducers) at temperatures up to 12000C

    International Nuclear Information System (INIS)

    In ferritic steel specimen the effect of phase transitions can be observed in the sound velocity and in the efficiency of ultrasonic generation in the temperature range up to 10000C. Especially above this temperature the decrease in sound velocity can be reliably compensated to measure the thickness of the specimen from the echo transit time. To reduce the lift-off effect of the EMAT, which deteriorates the signal to noise ratio especially in the region of high ultrasonic damping at temperatures above 10000C, it is proposed to guide the probes independently of the magnet close the surface of the specimen. (orig./HP)

  12. Graphics modelling of non-contact thickness measuring robotics work cell

    Science.gov (United States)

    Warren, Charles W.

    1990-01-01

    A system was developed for measuring, in real time, the thickness of a sprayable insulation during its application. The system was graphically modelled, off-line, using a state-of-the-art graphics workstation and associated software. This model was to contain a 3D color model of a workcell containing a robot and an air bearing turntable. A communication link was established between the graphics workstations and the robot's controller. Sequences of robot motion generated by the computer simulation are transmitted to the robot for execution.

  13. A new approach for the measurement of film thickness in liquid face seals

    OpenAIRE

    Reddyhoff, T.; Dwyer-Joyce, R.S.; Harper, P

    2008-01-01

    Face seals operate by allowing a small volume of the sealed fluid to escape and form a thin film between the contacting parts. The thickness of this film must be optimized to ensure that the faces are separated, yet the leakage is minimized. In this work the liquid film is measured using a novel ultrasonic approach with a view to developing a condition monitoring tool. The trials were performed in two stages. Initially tests were based on a lab simulation, where it was possible to compare the...

  14. Non-Contact Measurement of Density and Thickness Variation in Dielectric Materials

    Science.gov (United States)

    Roth, Ron

    2009-01-01

    This non-contact, single-sided terahertz electromagnetic measurement and imaging method characterizes micro structural (e.g., spatially-lateral density) and thickness variation in dielectric (insulating) materials. This method was demonstrated for space shuttle external tank sprayed-on foam insulation and has been designed for use as an inspection method for current and future NASA thermal protection systems and other dielectric material inspection applications where no contact can be made with the sample due to fragility and it is impractical to use ultrasonic methods

  15. Development of a semi-automatic beta-backscatter thickness-measuring system

    International Nuclear Information System (INIS)

    The semi-automated beta-backscatter system was evaluated to determine the overall system capability. The capability studies performed on the system indicate that the system can measure aluminum nominally 11.33 μm (450 μin.) thick on a Kapton substrate to a precision of better than 0.72 percent (one standard deviation = +- 0.0816 μm) in a time interval of 10 seconds. The report also covers various fail safe devices installed in the positioning fixture, and changes made in the system's software to facilitate operation of the system and storage of data

  16. Improved retrieval of aerosol optical thickness from MODIS measurements through derived surface reflectance over Nanjing, China

    OpenAIRE

    Zha, Yong; Wang, Qiao; Yuan, Jie; Gao, Jay; Jiang, Jianjun; Lu, Heng; Huang, Jiazhu

    2011-01-01

    Determination of surface reflectance in the red and blue channels is a critical step in retrieving aerosol optical thickness (AOT) from Moderate Resolution Imaging Spectroradiometer (MODIS) measurements. The MODIS Collection 005 (C005) aerosol algorithm uses a ratio method to determine the surface reflectance in the red (0.66 μm) and blue (0.47 μm) channels from the surface reflectance in the 2.1 μm channel using global surface reflectance relationships. In this study, we attempted to improve...

  17. On-Line Thickness Measurement for Two-Layer Systems on Polymer Electronic Devices

    Directory of Open Access Journals (Sweden)

    Ana Perez Grassi

    2013-11-01

    Full Text Available During the manufacturing of printed electronic circuits, different layers of coatings are applied successively on a substrate. The correct thickness of such layers is essential for guaranteeing the electronic behavior of the final product and must therefore be controlled thoroughly. This paper presents a model for measuring two-layer systems through thin film reflectometry (TFR. The model considers irregular interfaces and distortions introduced by the setup and the vertical vibration movements caused by the production process. The results show that the introduction of these latter variables is indispensable to obtain correct thickness values. The proposed approach is applied to a typical configuration of polymer electronics on transparent and non-transparent substrates. We compare our results to those obtained using a profilometer. The high degree of agreement between both measurements validates the model and suggests that the proposed measurement method can be used in industrial applications requiring fast and non-contact inspection of two-layer systems. Moreover, this approach can be used for other kinds of materials with known optical parameters.

  18. On-Line Thickness Measurement for Two-Layer Systems on Polymer Electronic Devices

    Science.gov (United States)

    Grassi, Ana Perez; Tremmel, Anton J.; Koch, Alexander W.; El-Khozondar, Hala J.

    2013-01-01

    During the manufacturing of printed electronic circuits, different layers of coatings are applied successively on a substrate. The correct thickness of such layers is essential for guaranteeing the electronic behavior of the final product and must therefore be controlled thoroughly. This paper presents a model for measuring two-layer systems through thin film reflectometry (TFR). The model considers irregular interfaces and distortions introduced by the setup and the vertical vibration movements caused by the production process. The results show that the introduction of these latter variables is indispensable to obtain correct thickness values. The proposed approach is applied to a typical configuration of polymer electronics on transparent and non-transparent substrates. We compare our results to those obtained using a profilometer. The high degree of agreement between both measurements validates the model and suggests that the proposed measurement method can be used in industrial applications requiring fast and non-contact inspection of two-layer systems. Moreover, this approach can be used for other kinds of materials with known optical parameters. PMID:24253192

  19. Ultrasonic superimpose effect and mode conversion on thickness/ diameter measurement of irradiation holes

    International Nuclear Information System (INIS)

    The HANARO (High-flux Advanced Neutron Application Reactor) has been operating since 1994. The irradiation 32 holes were implanted for isotopes production, pneumatic hydraulic transfer system, fuel test loop, neutron hole. It is necessary to measure the inside diameter and thickness of the holes for a good fitting as well as for detecting the corrosion and the structure deformation. Due to an accessibility and a high radiation, a mechanical method is not permitted. The immersion ultrasonic technique is adopted to precisely measure the thickness as well as the diameter. The 4 axes manipulator of the 2 channel of a sensor module is fabricated. The transducer, 10 MHz, results in 0.01 mm of the resolution tolerance. A mode conversion and superimpose effect are observed on the cylindrical shape due to the curvature and surface roughness. The basic data of measurement of the CN hole is referenced not only in the design of a neutron source facility but also in a routine inspection in according to IAEA working ID 35-G7.

  20. Intima-Media Thickness Measurements in the Fetus and Mother During Pregnancy

    DEFF Research Database (Denmark)

    Galjaard, Sander; Pasman, Suzanne A; Ameye, Lieveke;

    2014-01-01

    Fetal intima-media thickness (IMT) has been suggested as a marker of pre-clinical atherosclerosis, and maternal IMT could be altered through dynamic circumstances related to pregnancy. We investigated the feasibility of measurement of IMT at four pre-defined fetal and four pre-defined maternal...... arterial locations to determine vascular changes that could be associated with impaired vascular function. IMT was measured from the first to third trimester (12-34 wk), in 38 low-risk pregnancies. We imaged a 10-mm region of interest using a Mindray (Shenzhen, China) high-resolution ultrasound machine...... pregnancy. There was a significant relation between gestational age and IMT in the umbilical artery (p = 0.03) and a significant relation between body mass index and IMT in the maternal common carotid artery (p = 0.01). IMT measurements are feasible in some maternal and fetal vessels of interest. Further...

  1. Factors affecting measurement of channel thickness in asymmetrical flow field-flow fractionation.

    Science.gov (United States)

    Dou, Haiyang; Jung, Euo Chang; Lee, Seungho

    2015-05-01

    Asymmetrical flow field-flow fractionation (AF4) has been considered to be a useful tool for simultaneous separation and characterization of polydisperse macromolecules or colloidal nanoparticles. AF4 analysis requires the knowledge of the channel thickness (w), which is usually measured by injecting a standard with known diffusion coefficient (D) or hydrodynamic diameter (dh). An accurate w determination is a challenge due to its uncertainties arising from the membrane's compressibility, which may vary with experimental condition. In the present study, influence of factors including the size and type of the standard on the measurement of w was systematically investigated. The results revealed that steric effect and the particles-membrane interaction by van der Waals or electrostatic force may result in an error in w measurement. PMID:25817708

  2. A Narrowband Impedance Measurement Technique for Thickness Shear Mode Resonator Sensors

    International Nuclear Information System (INIS)

    This paper discusses a new technique for measuring the impedance response of thickness shear mode (TSM) resonators used as fluid monitors and chemical sensors. The technique simulates the swept frequency measurements performed by an automatic network analyzer (ANA), determining the complex reflection scattering parameter, S1l, from single port devices. Unlike oscillator circuits most often used with TSM resonators, narrowband spectral measurements are not limited by cable capacitance between resonator and oscillator allowing placement of the sensor in severe environments. Only noise produced by long cable lengths limits performance and sensor sensitivity. This new technique utilizes a simple swept frequency source operating near the crystal resonance, a unique directional coupler to provide the reference and reflected RF signals, an I ampersand Q demodulation circuit that returns two dc voltages, and computational algorithms for determining sensor response parameters. Performance, has been evaluated by comparing TSM resonator responses using this new technique to those from a commercial ANA

  3. Optical in-situ monitoring system for simultaneous measurement of thickness and curvature of thick layer stacks during hydride vapor phase epitaxy growth of GaN

    Science.gov (United States)

    Semmelroth, K.; Berwian, P.; Schröter, C.; Leibiger, G.; Schönleber, M.; Friedrich, J.

    2015-10-01

    For improved real-time process control we integrated a novel optical in-situ monitoring system in a vertical reactor for hydride vapor phase epitaxy (HVPE) growth of gallium nitride (GaN) bulk crystals. The in-situ monitoring system consists of a fiber-optical interferometric sensor in combination with an optimized differential measuring head. The system only needs one small optical path perpendicular to the center of the layer stack typically consisting of sapphire as substrate and GaN. It can handle sample distances up to 1 m without difficulty. The in-situ monitoring system is simultaneously measuring the optical layer thicknesses of the GaN/sapphire layer stack and the absolute change of the distance between the measuring head and the backside of the layer stack. From this data it is possible to calculate the thickness of the growing GaN up to a thickness of about 1000 μm and the absolute change in curvature of the layer stack. The performance of the in-situ monitoring system is shown and discussed based on the measured interference signals recorded during a short-time and a long-time HVPE growth run.

  4. Application of XRF to measure strontium in human bone in vivo

    International Nuclear Information System (INIS)

    As a basis for better understanding the role that Sr fulfills in human body, it is desirable to measure directly the main Sr store in human body. Although strontium is omnipresent in human tissues, 99% is stored inthe mineral portion of the bone. In the present study x-ray fluorescence (XRF) was applied to measure the strontium content of the tibial shaft in vivo. The feasibility studies showed that normal levels of stable strontium in the bone can be measured successfully

  5. Measurement of Ca/sup 2 +/ effluxes from bone

    Energy Technology Data Exchange (ETDEWEB)

    Neuman, W.F.; Brommage, R.; Myers, C.R.

    1977-01-01

    To facilitate the study of membrane function in the control of the flow of ions into and out of bone, it was desirable to develop a system for the direct quantitation of unidirectional effluxes of calcium and phosphate from bones. Based on a mathematical analysis of the problem, a specially designed Ussing chamber was developed which proved successful. Calvaria from 2-day-old rat pups, 3-day chicks and adult mice were evaluated. Calcium influxes which exceeded the corresponding effluxes were observed in the neonatal calvaria but not with those from adult mice. Also, an asymmetry in efflux was observed in rat calvaria, the inner side of the skull showed a higher efflux than did the external side. No such asymmetry was seen with calvaria from chicks or mice. This new technology should permit a further exploration of the role of the bone membrane in electrolyte homeostasis.

  6. A Reinforcement Plate for Partially Thinned Pressure Vessel Designed to Measure the Thickness of Vessel Wall Applying Ultrasonic Technique

    International Nuclear Information System (INIS)

    It is very hard to preserve the wall thickness of the vessel because of the erosion or corrosion as time goes by. Therefore, the wall thicknesses of heaters in power plants are periodically measured using ultrasonic test. If the integrity of the wall thickness is estimated not to secure, the reinforcement plate is welled on the thinned area of the vessel. The overlay weld of the reinforcement plate on the thinned vessel is normally the fillet welding. As shown by the references, the reinforcement plate with adequate thickness does its role very well before the vessel wall is perforated due to thinning. However, the integrity of shell cannot insure because the weldment is directly applied by the shell side pressure to after the vessel wall is perforated. Therefore, it is needed to measure the thickness of thinned area under the reinforcement plate continuously for preserving integrity and planning the fabrication of replacement vessel. It is impossible to apply the ultrasonic thickness measurement technique after the reinforcement plate is welded on the shell. In this paper new reinforcement plate, which makes it possible to measure the wall thickness under the reinforcement plate applying the ultrasonic technique, is introduced. A method to evaluate the structural integrity of a fillet weldment for the reinforcement plate welded on a pressure vessel is introduced in this paper. Moreover, new reinforcement plate, which makes it possible to measure the wall thickness of pressure vessels under the reinforcement plate applying the ultrasonic technique, is introduced

  7. Measuring the thickness of the peritoneal membrane in mice with optical coherence tomography

    Science.gov (United States)

    Alwafi, Reem; Dickinson, Mark; Brenchley, Paul; Walkin, Louise

    2011-06-01

    The detection and diagnosis of diseases have improved in recent years. Developments in diagnostic techniques have helped to improve treatment in the early stages and to avoid many risks to patients. One such technique is optical coherence tomography (OCT), which is used in many medical applications to perform internal microstructural imaging of the human body at high resolution (typically 10 μm), at high speed and in real time. OCT is non-invasive and can be used as a contact or non-contact technique to obtain an image. In medicine, there are many applications that involve OCT, such as in ophthalmology, gastroenterology, cardiology and oncology. This work demonstrates the use of an OCT system incorporating a swept laser source with a high sweep rate of 16 kHz over a wide range of wavelengths (1260 nm to 1390 nm) to measure the thickness of the peritoneal membrane in mice of different sizes and weights. The real axial line speed is limited by the source that is used in the OCT system. The optical source has a bandwidth of ▵λ =110 nm, centred at λ0 =1325 nm. The aim of this study is to investigate the thickening of the peritoneal membrane which can occur during prolonged peritoneal dialysis in mice. As part of this preliminary study, healthy mice of different weights were euthanized and the thickness of the peritoneal membrane was measured using OCT. The aim was to gather data on the expected range of thicknesses present in healthy animals for future studies. For this work, two locations on the peritoneal membrane of each of 20 mice were imaged.

  8. Reliability of ultrasound imaging for the measurement of abdominal muscle thickness in typically developing children

    Directory of Open Access Journals (Sweden)

    M. Unger

    2010-02-01

    Full Text Available Introduction: A bdominal muscles are key to both posture andgait in both children with typical development (TD and with disabilities.Ultrasound (US imaging is a potential non-invasive method for investigatingactivity in these muscles. This study therefore aimed to determine the inter-tester and intra-tester reliability of B-mode US for investigating transverseabdominus (TrA , rectus abdominus (RA and external- (EO and internaloblique (IO muscle activity in children with TD. Design: A  prospective cor-relational descriptive study.  Participants:  Eighty six, 6-13year old children from one private and one public mainstream school. Outcome measures: Two sets of B-mode US images where captured per subject during rest and during head-up, resisted head-up and resisted sling activities. Intra-class Correlation Coefficients (ICC and standard error of measurement (SEM were used to analyse the data. Results: Good correlation was found for both test - retest condi-tions for all four muscles tested during rest: 0.91(TrA ; 0.90(IO; 0.91(EO; 0.94(RA for intra-tester reliability and0.74(TrA ; 0.88(IO; 0.74(EO; 0.83(RA for inter-tester reliability. Repeatability of thickness measures during activity however showed variation in recruitment patterns. A  significant correlation was found between age and BMI andresting abdominal muscle thickness (p<0.001. Conclusion: The study supports the reliability of US measurement of resting abdominal muscles and of the RA  under active conditions in children aged six to 13. However the stability o measurement of the other muscles under active conditions still needs to be established.

  9. Depth measurements of drilled holes in bone by laser triangulation for the field of oral implantology

    Science.gov (United States)

    Quest, D.; Gayer, C.; Hering, P.

    2012-01-01

    Laser osteotomy is one possible method of preparing beds for dental implants in the human jaw. A major problem in using this contactless treatment modality is the lack of haptic feedback to control the depth while drilling the implant bed. A contactless measurement system called laser triangulation is presented as a new procedure to overcome this problem. Together with a tomographic picture the actual position of the laser ablation in the bone can be calculated. Furthermore, the laser response is sufficiently fast as to pose little risk to surrounding sensitive areas such as nerves and blood vessels. In the jaw two different bone structures exist, namely the cancellous bone and the compact bone. Samples of both bone structures were examined with test drillings performed either by laser osteotomy or by a conventional rotating drilling tool. The depth of these holes was measured using laser triangulation. The results and the setup are reported in this study.

  10. An electromagnetic noncontacting sensor for thickness measurement in a dispersive medium

    Science.gov (United States)

    Chufo, Robert L.

    1994-01-01

    This paper describes a general purpose imaging technology developed by the U.S. Bureau of Mines (USBM) that, when fully implemented, will solve the general problem of 'seeing into the earth.' A first-generation radar coal thickness sensor, the RCTS-1, has been developed and field-tested in both underground and highwall mines. The noncontacting electromagnetic technique uses spatial modulation created by moving a simple sensor antenna in a direction along each axis to be measured while the complex reflection coefficient is measured at multiple frequencies over a two-to-one bandwidth. The antenna motion imparts spatial modulation to the data that enables signal processing to solve the problems of media, target, and antenna dispersion. Knowledge of the dielectric constant of the media is not necessary because the electrical properties of the media are determined automatically along with the distance to the target and thickness of each layer of the target. The sensor was developed as a navigation guidance sensor to accurately detect the coal/noncoal interface required for the USBM computer-assisted mining machine program. Other mining applications include the location of rock fractures, water-filled voids, and abandoned gas wells. These hazards can be detected in advance of the mining operation. This initiating technology is being expanded into a full three-dimensional (3-D) imaging system that will have applications in both the underground and surface environment.

  11. Computer Vision Based Automatic Extraction and Thickness Measurement of Deep Cervical Flexor from Ultrasonic Images.

    Science.gov (United States)

    Kim, Kwang Baek; Song, Doo Heon; Park, Hyun Jun

    2016-01-01

    Deep Cervical Flexor (DCF) muscles are important in monitoring and controlling neck pain. While ultrasonographic analysis is useful in this area, it has intrinsic subjectivity problem. In this paper, we propose automatic DCF extractor/analyzer software based on computer vision. One of the major difficulties in developing such an automatic analyzer is to detect important organs and their boundaries under very low brightness contrast environment. Our fuzzy sigma binarization process is one of the answers for that problem. Another difficulty is to compensate information loss that happened during such image processing procedures. Many morphologically motivated image processing algorithms are applied for that purpose. The proposed method is verified as successful in extracting DCFs and measuring thicknesses in experiment using two hundred 800 × 600 DICOM ultrasonography images with 98.5% extraction rate. Also, the thickness of DCFs automatically measured by this software has small difference (less than 0.3 cm) for 89.8% of extracted DCFs. PMID:26949411

  12. Central Corneal Thickness Measurements in Nonarteritic Anterior Ischemic Optic Neuropathy Patients: A Controlled Study

    Directory of Open Access Journals (Sweden)

    Haneen Jabaly-Habib

    2014-01-01

    Full Text Available Purpose. To measure central corneal thickness (CCT in patients with history of nonarteritic anterior ischemic optic neuropathy (NAION. Patients and Methods. Patients older than 40 years with a history of NAION (group 1 were prospectively evaluated including full eye examination and central corneal thickness (CCT pachymetry. Patients with a history of intraocular surgery, corneal disease, glaucoma, and contact lens wear were excluded. Measurements were also performed in a gender and age matched control group (group 2. Results. Thirty-one eyes of 31 NAION patients in group 1 were included and 30 eyes of 30 participants in group 2. There were 15 men in group 1 and 9 in group 2 P=0.141, and mean age of the patients was 59±10 years in group 1 versus 61±11 years in group 2 P=0.708. Mean CCT was 539±30 microns in group 1 and 550±33 microns in group 2 P=0.155. Conclusion. Patients with NAION have no special characteristic of CCT in contrast to the crowded optic disc known to be a significant anatomic risk factor for NAION. More studies should be carried out to investigate CCT and other structure related elements in NAION patients.

  13. New developments in the analysis and measurement of thicknesses by β-particle excitation of X fluorescent rays

    International Nuclear Information System (INIS)

    The method of analysing and measuring the thickness of deposits by β-X fluorescence which we previously described has been further developed. Using Pm147 and Kr85 sources, it is possible to reduce the background observed with Sr90. We quote the results obtained for various thickness measurements of metal deposits, an analysis of the solutions, and the continuous measurement of calcium and iron in core samples. We describe experiments made for analysis of the X-radiation by crystal. (author)

  14. Ultrasound Estimated Bladder Weight and Measurement of Bladder Wall Thickness-Useful Noninvasive Methods for Assessing the Lower Urinary Tract?

    NARCIS (Netherlands)

    E. Bright; M. Oelke; A. Tubaro; P. Abrams

    2010-01-01

    Purpose: In the last decade interest has arisen in the use of ultrasound derived measurements of bladder wall thickness, detrusor wall thickness and ultrasound estimated bladder weight as potential diagnostic tools for conditions known to induce detrusor hypertrophy. However, to date such measuremen

  15. Quantifying bone weathering stages using the average roughness parameter Ra measured from 3D data

    Science.gov (United States)

    Vietti, Laura A.

    2016-09-01

    Bone surface texture is known to degrade in a predictable fashion due to subaerial exposure, and can thus act as a relative proxy for estimating temporal information from modern and ancient bone assemblages. To date, the majority of bone weathering data is collected on a categorical scale based on descriptive terms. While this qualitative classification of weathering data is well established, textural analyses of bone surfaces may provide means to quantify weathering stages but have yet to be tested. Here, I examined the suitability of textural analyses for bone weathering studies by first establishing bone surface regions most appropriate for weathering analyses. I then measured and compared the roughness texture of weathered bones at different stages. To establish regions of bone most suitable for textural analyses, Ra was measured from 3D scans of dorsal ribs of four adult ungulate taxa. Results indicate that the rib-shafts from unweathered ungulate skeletons were similar and are likely good candidates because differences in surface texture will not be due to differences in initial bone texture. To test if textural measurements could reliably characterize weathering stages, the average roughness values (Ra) were measured from weathered ungulate rib-shafts assigned to four descriptive weathering stages. Results from analyses indicate that the Ra was statistically distinct for each weathering stage and that roughness positively correlates with the degree of weathering. As such, results suggest that textural analyses may provide the means for quantifying bone-weathering stages. Using Ra and other quantifiable texture parameters may enable more reliable and comparative taphonomic analyses by reducing inter-observer variations and by providing numerical data more compatible for multivariate statistics.

  16. Instrument for thickness measuring of a workpiece with the help of ultrasonic waves

    International Nuclear Information System (INIS)

    The proposed ultrasonic measuring instrument has a generator for pulsed ultrasonic signals, a detector as well as a contact arrangement that connects both with the work piece. The transportation lag of the signals through the contact arrangements amounts to at least five times the transportation lag of the signals due to the thickness of a work piece. Furthermore there is an arrangement for the measurement of the delay between two successive echos from the back of the work piece with the help of a zero passage detector for the generation of a time-reference value on each echo signal. This permits an exact time control of the pulses which range in the field around nano seconds. The instrument is explained with 8 drawings and a detailed description. (RW)

  17. Carotid Artery Segmentation in Ultrasound Images and Measurement of Intima-Media Thickness

    Directory of Open Access Journals (Sweden)

    Vaishali Naik

    2013-01-01

    Full Text Available Background. The segmentation of the common carotid artery (CCA wall is imperative for the determination of the intima-media thickness (IMT on B-mode ultrasound (US images. The IMT is considered an important indicator in the evaluation of the risk for the development of atherosclerosis. In this paper, authors have discussed the relevance of measurements in clinical practices and the challenges that one has to face while approaching the segmentation of carotid artery on ultrasound images. The paper presents an overall review of commonly used methods for the CCA segmentation and IMT measurement along with the different performance metrics that have been proposed and used for performance validation. Summary and future directions are given in the conclusion.

  18. Measuring technique of liner thickness of zirconium-lined zircaloy-2 tube-shell using ultrasonic method

    International Nuclear Information System (INIS)

    In order to control the liner thickness of a Zr-lined Zircaloy fuel cladding tube, it is very important to know accurately the liner thickness of the original tube from which it was rolled. A new technique was developed using an ultrasonic method to measure liner thickness. It measures at every point on the circumference over the 4-meter length of the original tube in only 3 minutes. The error of measurement is less than 50 microns. The technique has been in use on the production line of our Chofu-Kita Plant. (author)

  19. Normal SUV values measured from NaF18- PET/CT bone scan studies.

    Directory of Open Access Journals (Sweden)

    Aung Zaw Win

    Full Text Available Cancer and metabolic bone diseases can alter the SUV. SUV values have never been measured from healthy skeletons in NaF18-PET/CT bone scans. The primary aim of this study was to measure the SUV values from normal skeletons in NaF18-PET/CT bone scans.A retrospective study was carried out involving NaF18- PET/CT bone scans that were done at our institution between January 2010 to May 2012. Our excluding criteria was patients with abnormal real function and patients with past history of cancer and metabolic bone diseases including but not limited to osteoporosis, osteopenia and Paget's disease. Eleven studies met all the criteria.The average normal SUVmax values from 11 patients were: cervical vertebrae 6.84 (range 4.38-8.64, thoracic vertebrae 7.36 (range 6.99-7.66, lumbar vertebrae 7.27 (range 7.04-7.72, femoral head 2.22 (range 1.1-4.3, humeral head 1.82 (range 1.2-2.9, mid sternum 5.51 (range 2.6-8.1, parietal bone 1.71 (range 1.3-2.4.According to our study, various skeletal sites have different normal SUV values. SUV values can be different between the normal bones and bones with tumor or metabolic bone disease. SUV can be used to quantify NaF-18 PET/CT studies. If the SUV values of the normal skeleton are known, they can be used in the characterization of bone lesions and in the assessment of treatment response to bone diseases.

  20. Central corneal thickness and anterior chamber depth measurement by Sirius® Scheimpflug tomography and ultrasound

    Science.gov (United States)

    Jorge, J; Rosado, JL; Díaz-Rey, JA; González-Méijome, JM

    2013-01-01

    Background The purpose of this study was to compare the accuracy of the new Sirius® Scheimpflug anterior segment examination device for measurement of central corneal thickness (CCT) and anterior chamber depth (ACD) with that of CCT measurements obtained by ultrasound pachymetry and ACD measurements obtained by ultrasound biometry, respectively. Methods CCT and ACD was measured in 50 right eyes from 50 healthy subjects using a Sirius Scheimpflug camera, SP100 ultrasound pachymetry, and US800 ultrasound biometry. Results CCT measured with the Sirius was 546 ± 39 μm and 541 ± 35 μm with SP100 ultrasound pachymetry (P = 0.003). The difference was statistically significant (mean difference 4.68 ± 10.5 μm; limits of agreement −15.8 to 25.20 μm). ACD measured with the Sirius was 2.96 ± 0.3 mm compared with 3.36 ± 0.29 mm using US800 ultrasound biometry (P < 0.001). The difference was statistically significant (mean difference −0.40 ± 0.16 mm; limits of agreement −0.72 to 0.07 mm). When the ACD values obtained using ultrasound biometry were corrected according to the values for CCT measured by ultrasound, the agreement increased significantly between both technologies for ACD measurements (mean difference 0.15 ± 0.16 mm; limits of agreement −0.16 to 0.45 mm). Conclusion CCT and ACD measured by Sirius and ultrasound methods showing good agreement between repeated measurements obtained in the same subjects (repeatability) with either instrument. However, CCT and ACD values, even after correcting ultrasound ACD by subtracting the CCT value obtained with either technology should not be used interchangeably. PMID:23467857

  1. New method for measuring the thickness and shape of a thin film simultaneously by combining interferometry and laser triangulation

    Science.gov (United States)

    Zeng, LiJiang; Ohnuki, Takeshi; Matsumoto, Hirokazu; Kawachi, Keiji

    1996-07-01

    A new method has been developed to simultaneously measure the thickness and shape of a thin film, such as a dragonfly wing. The innovation in the method is the combining of a heterodyne interferometer and a laser triangulation displacement sensor into one optical system. We confirmed the accuracy of the method by measuring the displacement of a glass plate and the thickness variation generated by a rotated glass plate. The system has a relative accuracy of 1% in the shape measurement and 1.3% in the thickness variation measurement. The method was then applied to a dragonfly wing. The results indicated that the method is very effective in biomechanics studies, such as evaluating the flight performance of dragonflies. In such evaluations, it is essential to measure the high accuracy the variations in both shape and thickness of the wing simultaneously.

  2. Photoplethysmography for non-invasive in vivo measurement of bone hemodynamics

    International Nuclear Information System (INIS)

    Developments in photoplethysmography (PPG) hardware make this device a promising tool for non-invasive deep-tissue hemodynamic measurements. The aim of this study was to validate the use of PPG as a tool for non-invasive bone hemodynamic measurements. A new PPG device capable of measuring bone hemodynamic responses was designed, tested and validated. Validation experiments included cold exposure, arterial occlusion, skin occlusion and nitroglycerin exposure. Cold exposure resulted in a decrease in skin perfusion (p = 0.011) and bone perfusion (p = 0.005); arterial occlusion also resulted in decreased skin perfusion (p < 0.001) and bone perfusion (p = 0.008), with arterial occlusion resulting in a greater decrease in perfusion than cold exposure. The independence of the skin and bone PPG signals was demonstrated by the ability to independently increase (p = 0.003) and decrease (p = 0.005) the skin signal without significantly affecting the bone signal. Our experiments build upon and expand previous PPG developments and validation studies. Our custom-made PPG hardware represents a state-of-the-art tool for non-invasive monitoring of deep tissues, and our data support the use of PPG as a valid tool for measuring bone hemodynamic responses in vivo. (paper)

  3. Uncertainty quantification in aerosol optical thickness retrieval from Ozone Monitoring Instrument (OMI) measurements

    Science.gov (United States)

    Määttä, A.; Laine, M.; Tamminen, J.; Veefkind, J. P.

    2013-10-01

    The space borne measurements provide global view of atmospheric aerosol distribution. The Ozone Monitoring Instrument (OMI) on board NASAs Earth Observing System (EOS) Aura satellite is a Dutch-Finnish nadir-viewing solar backscatter spectrometer measuring in the ultraviolet and visible wavelengths. OMI measures several trace gases and aerosols that are important in many air quality and climate studies. The OMI aerosol measurements are used, for example, for detecting volcanic ash plumes, wild fires and transportation of desert dust. We present a methodology for improving the uncertainty quantification in the aerosols retrieval algorithm. We have used the OMI measurements in this feasibility study. Our focus is on the uncertainties originating from the pre-calculated aerosol models. These models are never complete descriptions of the reality. This aerosol model uncertainty is estimated using Gaussian processes with computational tools from spatial statistics. Our approach is based on smooth systematic differences between the observed and modelled reflectances. When acknowledging this model inadequacy in the estimation of aerosol optical thickness (AOT), the uncertainty estimates are more realistic. We present here a real world example of applying the methodology.

  4. Measurement of neutron yield by 62 MeV proton beam on a thick beryllium target

    International Nuclear Information System (INIS)

    The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0° to 150° and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their time of flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a 3He detector was used. The obtained data are in good agreement with previous measurements at 0° using 66 MeV proton beam, covering neutron energies >10MeV, as well as with measurements at few selected angles using protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60–70 MeV beam energy range. A comparison of measured yields to MCNP, FLUKA and Geant4 Monte Carlo simulations was performed

  5. Measurement of neutron yield by 62 MeV proton beam on a thick beryllium target

    Energy Technology Data Exchange (ETDEWEB)

    Osipenko, M., E-mail: osipenko@ge.infn.it [INFN, sezione di Genova, 16146 Genova (Italy); Ripani, M. [INFN, sezione di Genova, 16146 Genova (Italy); Alba, R. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Ricco, G. [INFN, sezione di Genova, 16146 Genova (Italy); Schillaci, M. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Barbagallo, M. [INFN, sezione di Bari, 70126 Bari (Italy); Boccaccio, P. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Celentano, A. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy); Colonna, N. [INFN, sezione di Bari, 70126 Bari (Italy); Cosentino, L.; Del Zoppo, A.; Di Pietro, A. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Esposito, J. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Figuera, P.; Finocchiaro, P. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Kostyukov, A. [Moscow State University, Moscow 119992 (Russian Federation); Maiolino, C.; Santonocito, D.; Scuderi, V. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Viberti, C.M. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy)

    2013-09-21

    The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0° to 150° and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their time of flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a {sup 3}He detector was used. The obtained data are in good agreement with previous measurements at 0° using 66 MeV proton beam, covering neutron energies >10MeV, as well as with measurements at few selected angles using protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60–70 MeV beam energy range. A comparison of measured yields to MCNP, FLUKA and Geant4 Monte Carlo simulations was performed.

  6. Aligning and measuring the curvature and thickness of high-precision lens

    Science.gov (United States)

    Wu, Kun-Huan; Chang, Shenq-Tsong; Hsu, Ming-Ying; Huang, Ting-Ming; Hsu, Wei-Yao; Tseng, Shih-Feng

    2015-09-01

    The radius of curvature is one of the most important specifications for spherical optics [1]. There are several methods and devices currently on the market that can be used to measure it, including optical level, non-contact laser interferometer (Interferometer), a probe-contact profiler (Profilometer), the centering machine and three-point contact ball diameter meter (Spherometer). The amount that can be measured with a radius of curvature of the lens aperture range depends on the interferometer standard lens f / number and lens of R / number (radius of curvature divided by the clear aperture of the spherical surface ratio between them). Unfortunately, for lens with diameter greater than 300 mm, the device is limited by the size of the holding fixture lenses or space. This paper aims to provide a novel surface contour detection method and machine, named "CMM spherometry by probe compensation," to measure the radius and thickness of the curvature of the optical surface by a coordinate measurement machine (CMM). In order to obtain more accurate optimization results, we used probe and temperature compensation to discuss the effect. The trace samples and the measurement results of CMM and the centering machine, which has top and bottom autocollimators, are compared.

  7. Exploration Of Activity Measurements And Equilibrium Checks For Sediment Dating Using Thick-Window Germanium Detectors

    Science.gov (United States)

    Warner, Jacob A.; Fitzsimmons, Kathryn E.; Reynolds, Eva M.; Gladkis, Laura G.; Timmers, Heiko

    2011-06-01

    Activity measurements on sediment samples for trapped-charge geological dating using gamma-ray spectroscopy are an important verification of the field-site dose rate determination. Furthermore gamma-ray spectroscopy can check if the natural decay series are in secular equilibrium which is a crucial assumption in such dating. Typically the activities of leading members of the Thorium and Uranium decay series are measured, which requires Germanium detectors with thin windows and good energy resolution in order to effectively detect the associated low energy gamma-rays. Such equipment is not always readily available. The potential of conventional Germanium detectors with thick entrance window has been explored towards routine gamma-ray spectroscopy of sediment samples using higher energy gamma-rays. Alternative isotopes, such as Ac-228 and Pb-212 for the Thorium series, and Pa-234m, Ra-226 and Bi-214 for the Uranium series, have been measured in order to determine the mass-specific activity for the respective series and possibly provide a check of secular equilibrium. In addition to measurements of the K-40 activity, with the alternative approach, the activities of both decay series can be accurately determined. The secular equilibrium condition may be tested for the Thorium series. Measurement accuracy for Pa-234m is, however, not sufficient to permit also a reliable check of equilibrium for the Uranium series.

  8. In-situ Measurement of Low-Z Material Coating Thickness on High Z Substrate for Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, D [PPPL; Roquemore, A L [PPPL; Jaworski, M [PPPL; Skinner, C H [PPPL; Miller, J [PPPL; Creely, A [PPPL; Raman, P [2University of Illinois, Champaign, IL, USA; Ruzic, D [2University of Illinois, Champaign, IL, USA

    2014-07-01

    Rutherford backscattering (RBS) of energetic particles can be used to determine the thickness of a coating of a low-Z material over a heavier substrate. Simulations indicate that 5 MeV alpha particles from an Am source can be used to measure the thickness of a Li coating on Mo tiles between 0.5 and 15 μm thick. Using a 0.1 mCi source, a thickness measurement can be accomplished in 2 hours of counting. This technique could be used to measure any thin, low-Z material coating (up to 1 mg/cm^2 thick) on a high-Z substrate, such as Be on W, B on Mo, or Li on Mo. By inserting a source and detector on a moveable probe, this technique could be used to provide an in situ measurement of the thickness of Li coating on NSTX-U Mo tiles. A test stand with an alpha source and an annular solid-state detector was used to investigate the measurable range of low-Z material thicknesses on Mo tiles.

  9. Determining bilayer hydrocarbon thickness from neutron diffraction measurements using strip-function models

    International Nuclear Information System (INIS)

    Neutron diffraction methods provide information about the distribution of matter in biological and model membrane systems. The information is derived from plots (profiles) of scattering length density along an axis normal to the membrane plane. Without the use of specific deuteration, the generally low resolution of the profiles limits their interpretation in terms of specific chemical constituents (e.g., lipid headgroup, lipid hydrocarbon, protein, and water). A fundamental and useful structural assignment to make is the boundary between the headgroup and hydrocarbon regions of bilayers. We demonstrate here that strip-function model representations of neutron scattering length density profiles of bilayers are sufficient to determine accurately the position of the headgroup-hydrocarbon boundary. The resulting hydrocarbon thickness of the bilayer is useful for determining the area per lipid molecule and consequently the molecular packing arrangements of the membrane constituents. We analyze data obtained from dioleoylphosphatidylcholine (DOPC) bilayers at 66% RH using standard Fourier profile analyses and from DOPC deuterated specifically at the C-2 carbon of the acyl chains using difference Fourier analysis. We demonstrate that strip-function models accurately define the positions of the C-2 carbons and thus the hydrocarbon thickness (dhc) of the bilayer. We then show, using quasi-molecular models, that the strip-model analysis probably provides an accurate measure of dhc because of the exceptionally high scattering length density difference between the carbonyl and methylene groups

  10. The effect of nuchal cord on nuchal fold thickness measured in the second trimester

    International Nuclear Information System (INIS)

    Purpose: To find out whether nuchal cord causes an effect on the nuchal skin fold thickness (NFT) measurements, or not. Patients and methods: A total of 242 fetuses with normal outcomes that had undergone detailed second trimester US scan between 18 and 24 weeks of gestation were included in the study. NFT measurements were made on axial cranial US images passing through the cerebellum and cavum septi pellucidum. To detect nuchal cord, color Doppler imaging was performed on the axial views of the fetal neck. To investigate the differences in NFT measurements of the fetuses with or without nuchal cord, statistical analysis was performed using Mann–Whitney test. P < 0.05 was considered statistically significant. Results: The study group was divided into two groups: nuchal cord (+) (n: 26) and nuchal cord (−) (n: 216) fetuses. Mean NFT measurements were 4.66 ± 0.64 mm and 4.36 ± 0.79 mm for nuchal cord (+) and nuchal cord (−) fetuses, respectively. Median NFT measurement for nuchal cord (+) fetuses was 4.6 mm, whereas it was 4.4 mm for nuchal cord (−) fetuses. Statistically significant difference was denoted between two groups, in terms of NFT measurements (P = 0.049). Conclusion: NFT measurements of fetuses with nuchal cord are higher than the NFT measurements of fetuses without nuchal cord. One can conclude that the nuchal cord (+) fetuses with no other anomalies but increased NFT should be re-scanned to see if the increased NFT resolves in the absence of nuchal cord.

  11. Bone density measurements in the diagnosis of osteoporosis

    International Nuclear Information System (INIS)

    In view of the continuously growing medical and economical importance of osteoporosis an up-dated survey is given of the four major densitometric methods used to visualise bones. In this connection, the technical procedures to be followed in single and dual photon absorptiometry (SPA and DPA), quantitative digital radiography (QDR) and quantitative computed tomography (QCT) are discussed just as well as their practical applications and specific roles in the diagnosis and follow-up observation of patients treated for osteoporosis. (orig.)

  12. Measurement of neutron yield by 62 MeV proton beam on a thick Beryllium target

    CERN Document Server

    Osipenko, M; Alba, R; Ricco, G; Barbagallo, M; Boccaccio, P; Celentano, A; Colonna, N; Cosentino, L; Del Zoppo, A; Di Pietro, A; Esposito, J; Figuera, P; Finocchiaro, P; Kostyukov, A; Maiolino, C; Santonocito, D; Schillaci, M; Scuderi, V; Viberti, C M

    2013-01-01

    The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate called for detailed data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick Beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0 to 150 degrees and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their Time of Flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a $^3$He detector was used. The obtained data are in good agreement with previous measurements at 0 degree with 66 MeV proton beam, covering neutron energies >10 MeV, as well as with measurements at few selected angles with protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60-70 MeV beam energy range. A comparison of measu...

  13. Three-dimensional quantification of structures in trabecular bone using measures of complexity

    DEFF Research Database (Denmark)

    Marwan, Norbert; Kurths, Jürgen; Thomsen, Jesper Skovhus; Felsenberg, Dieter; Saparin, Peter

    2009-01-01

    The study of pathological changes of bone is an important task in diagnostic procedures of patients with metabolic bone diseases such as osteoporosis as well as in monitoring the health state of astronauts during long-term space flights. The recent availability of high-resolution three......-dimensional (3D) imaging of bone challenges the development of data analysis techniques able to assess changes of the 3D microarchitecture of trabecular bone. We introduce an approach based on spatial geometrical properties and define structural measures of complexity for 3D image analysis. These measures...... evaluate different aspects of organization and complexity of 3D structures, such as complexity of its surface or shape variability. We apply these measures to 3D data acquired by high-resolution microcomputed tomography (µCT) from human proximal tibiae and lumbar vertebrae at different stages of...

  14. Comparison of central corneal thickness measured by Lenstar LS900, OrbscanⅡ and ultrasonic pachmetry

    Directory of Open Access Journals (Sweden)

    Hong-Tao Zhang

    2013-09-01

    Full Text Available AIM: To investigate the difference of central corneal thickness(CCTmeasured by Lenstar LS900, OrbscahⅡ system and ultrasonic pachmetry, and to evaluate the correlation and consistency of the results for providing a theoretical basis for clinical application.METHODS: The mean value of CCT in 70 eyes of 35 patients measured three times by Lenstar LS900, OrbscahⅡ system and ultrasonic pachmetry underwent statistical analysis. The difference of CCT was compared, and the correlation and consistency of three measurements were analyzed to provide theoretical basis for clinical application. CCT values measured by different methods were analyzed with randomized block variance analysis. LSD-t test was used for pairwise comparison between groups. The correlation of three measurement methods were analyzed by linear correlation analysis, and Bland-Altman was used to analyze the consistency.RESULTS: The mean CCT values measured by Lenstar LS900, OrbscanⅡ and ultrasonic pachmetry were 542.75±40.06, 528.74±39.59, 538.54±40.93μm, respectively. The mean difference of CCT measurement was 4.21±8.78μm between Lenstar LS900 and ultrasonic pachmetry, 14.01±13.39μm between Lenstar LS900 and Orbscan Ⅱ, 9.8±10.57μm between ultrasonic pachmetry and Orbscan Ⅱ. The difference was statistically significant(PP>0.05: There was positive correlation between CCT with Lenstar LS900 and ultrasonic pachmetry(r=0.977, 0.944; PCONCLUSION: There are excellent correlation among Lenstar LS900, Orbscan Ⅱ and ultrasonic pachmetry. Lenstar LS900 can be used as CCT non-contact measurement tool.

  15. Fluorescence measurements for evaluating the application of multivariate analysis techniques to optically thick environments.

    Energy Technology Data Exchange (ETDEWEB)

    Reichardt, Thomas A.; Timlin, Jerilyn Ann; Jones, Howland D. T.; Sickafoose, Shane M.; Schmitt, Randal L.

    2010-09-01

    Laser-induced fluorescence measurements of cuvette-contained laser dye mixtures are made for evaluation of multivariate analysis techniques to optically thick environments. Nine mixtures of Coumarin 500 and Rhodamine 610 are analyzed, as well as the pure dyes. For each sample, the cuvette is positioned on a two-axis translation stage to allow the interrogation at different spatial locations, allowing the examination of both primary (absorption of the laser light) and secondary (absorption of the fluorescence) inner filter effects. In addition to these expected inner filter effects, we find evidence that a portion of the absorbed fluorescence is re-emitted. A total of 688 spectra are acquired for the evaluation of multivariate analysis approaches to account for nonlinear effects.

  16. Development and manufacturing of a thickness gauge for hot-rolled tubes measuring on Riza tube plant

    International Nuclear Information System (INIS)

    On Riza tube plant (DDR) a gauge for continuous tube wall thickness measurements has been developed and put into operation. The measurements are done both after an expanding mill and after the mill where tubes are taken off the mandrel. The gauge permits quickly eliminate tube wall thickness deviations from the predetermined value, thus the tube quality being improved and metal saved. The gauge is designed so that there is practically no possibility for the staff to get into the zone of radioactive radiation that is used. Technical characteristics of the gauge are as follows: measurements are contactless; measured material temperature, 700-1000 grad.C, measured material velocity, up to 1.5 m/s; outer wall diameter, 60-140 mm; wall thickness, 2.6-20 mm; measurement precision, 3%; resolution, 0.1 mm; measurement result delay, 8 tubes

  17. Ultrasonic measurements on residual stress in autofrettged thick walled petroleum pipes

    International Nuclear Information System (INIS)

    The residual stresses in a component or structure are caused by incompatible permanent deformation and related gradient of plastic/elastic strains. They may be generated or modified at every stage in the components life cycle, from original material production to final disposal. Residual stresses can be measured by non-destructive techniques, including X-ray and neutron diffraction, magnetic and ultrasonic methods. The selection of the optimum measurement technique should take account volumetric resolution, material, geometry and access to the component. For large metallic components neutron diffraction is of prime importance as it provides quantitative information on stresses in relatively large volume of methods disregarding its shape complexity. Residual stresses can play a significant role in explaining or preventing failure of components of industrial installations. One example of residual stresses preventing failure are the ones generated by shot peening, inducing surface compressive stresses that improve the fatigue life. Petroleum refinery piping is generally characterized by large-diameters, operated at elevated temperature and under high pressure. Pipelines of a polyethylene plant working in one of the Polish refineries are subjected to pressures exceeding 300 MPa at temperatures above 200oC. The pipes considered here were pressurized with pressure of 600 MPa. The wall thickness of the pipes is 27 mm and pipe dimensions are 46 x 100 mm. The material is steel with Re=580 MPa. Due to pressurizing, the components retain compressive stresses at the internal surface. These stresses increase resistance to cracking of the pipes. Over the period of exploitation these stresses diminish due to temperature activated relaxation or creep. The purpose of the project is to verify kinetics of such a relaxation process and calibrate alternative methods of their measurements. To avoid stress relaxation, numerical analysis from Finite Element Modelling (FEM)gave an optimal

  18. Measurement of attenuation coefficients for bone, muscle, fat and water at 140, 364 and 662keV γ-ray energies

    International Nuclear Information System (INIS)

    The half-value thicknesses, linear and mass attenuation coefficients of biological samples such as bone, muscle, fat and water have been measured at 140, 364 and 662keV γ-ray energies by using the ATOMLABTM-930 medical spectrometer. The γ-rays were obtained from 99mTc, 131I and 137Cs γ-ray point sources. Also theoretical calculations have been performed in order to obtain the half-value thicknesses and, mass and linear attenuation coefficients at photon energies 0.001keV-20MeV for bone, muscle and water samples. The calculated value and the experimental results of this work and the other results in literature are found to be in good agreement

  19. Effect of the cortex on ultrasonic backscatter measurements of cancellous bone

    International Nuclear Information System (INIS)

    Ultrasonic backscatter techniques offer a promising new approach for detecting changes in bone caused by osteoporosis. However, several challenges impede clinical implementation of backscatter techniques. This study examines how the dense outer surface of bone (the cortex) affects backscatter measurements of interior regions of porous (cancellous) bone tissue. Fifty-two specimens of bone were prepared from 13 human femoral heads so that the same region of cancellous bone could be ultrasonically interrogated through the cortex or along directions that avoided the cortex. Backscatter signals were analyzed over a frequency range of 0.8-3.0 MHz to determine two ultrasonic parameters: apparent integrated backscatter (AIB) and frequency slope of apparent backscatter (FSAB). The term 'apparent' means that the parameters are sensitive to the frequency-dependent effects of diffraction and attenuation. Significant (p < 0.001) changes in AIB and FSAB indicated that measurements through the cortex decreased the apparent backscattered power and increased the frequency dependence of the power. However, the cortex did not affect the correlation of AIB and FSAB with the x-ray bone mineral density of the specimens. This suggests that results from many previous in vitro backscatter studies of specimens of purely cancellous bone may be extrapolated with greater confidence to in vivo conditions.

  20. Morphological and functional relationships with ultrasound measured muscle thickness of the lower extremity: a brief review.

    Science.gov (United States)

    Abe, Takashi; Loenneke, Jeremy P; Thiebaud, Robert S

    2015-08-01

    Ultrasound is a potential method for assessing muscle size of the extremity and trunk. In a large muscle, however, a single image from portable ultrasound measures only muscle thickness (MT), not anatomical muscle cross-sectional area (CSA) or muscle volume (MV). Thus, it is important to know whether MT is related to anatomical CSA and MV in an individual muscle of the extremity and trunk. In this review, we summarize previously published articles in the lower extremity demonstrating the relationships between ultrasound MT and muscle CSA or MV as measured by magnetic resonance imaging and computed tomography scans. The relationship between MT and isometric and isokinetic joint performance is also reviewed. A linear relationship is observed between MT and muscle CSA or MV in the quadriceps, adductor, tibialis anterior, and triceps surae muscles. Intrarater correlation coefficients range from 0.90 to 0.99, except for one study. It would appear that anterior upper-thigh MT, mid-thigh MT and posterior thigh MT are the best predictors for evaluating adductor, quadriceps, and hamstrings muscle size, respectively. Despite a limited number of studies, anterior as well as posterior lower leg MT appear to reflect muscle CSA and MV of the lower leg muscles. Based on previous studies, ultrasound measured anterior thigh MT may be a valuable predictor of knee extension strength. Nevertheless, more studies are needed to clarify the relationship between lower extremity function and MT. PMID:27433253

  1. Measurement of maxillary sinus volume and available alveolar bone height using computed tomography

    International Nuclear Information System (INIS)

    To aid in determining the volume of graft bone required before a maxillary sinus lift procedure and compare the alveolar bone height measurements taken by panoramic radiographs to those by CT images. Data obtained by both panoramic radiographs and CT examination of 25 patients were used in this study. Maxillary sinus volumes from the antral floor to heights of 5 mm, 10 mm, 15 mm, and 20 mm , were calculated. Alveolar bone height was measured on the panoramic images at each maxillary tooth site and corrected by magnification rate (PBH). Available bone height (ABH) and full bone height (FBH) was measured on reconstructed CT images. PBH was compared with ABH and FBH at the maxillary incisors, canines, premolars, and molars. Volumes of the inferior portion of the sinuses were 0.55 ± 0.41 cm3 for 5 mm lifts, 2.11 ± 0.68 cm3 for 10 mm, 4.26 ± 1.32 cm3 for 15 mm, 6.95 ± 2.01 cm3 for 20 mm. For the alveolar bone measurement, measurements by panoramic images were longer than available bone heights determined by CT images at the incisor and canine areas, and shorter than full bone heights on CT images at incisor, premolar, and molar areas (p3 or more is required for a 5 mm - lift, 2.79 cm3 or more for a 10 mm - lift, 5.58 cm3 or more for a 15 mm - lift, and 8.96 cm3 or more for a 20 mm - lift. Maxillary implant length determined using panoramic radiograph alone could result in underestimation or overestimation, according to the site involved.

  2. Through-Thickness Measurements of Residual Stresses in an Overlay Dissimilar Weld Pipe using Neutron Diffraction

    International Nuclear Information System (INIS)

    The distribution of residual stresses in dissimilar material joints has been extensively studied because of the wide applications of the dissimilar welds in many inevitable complex design structures. Especially the cracking of dissimilar welding has been a long standing issue of importance in many components of the power generation industries such as nuclear power plant, boiling pressure system, and steam generators. In particular, several failure analysis and direct observations have shown that critical fractures have frequently occurred in one side of the dissimilar welded parts. For example, the heat-affected zone on the ferrite steel side is known to critical in many dissimilar welding pipes when ferrite (low carbon steel) and austenite (stainless) steels are joined. The main cause of the residual stresses can be attributed to the mismatch in the coefficient of thermal expansion between the dissimilar metals (ferrite and austenite). Additional cladding over circumferential welds is known to reinforce the mechanical property due to the beneficial compressive residual stress imposed on the weld and heat-affected zone. However, science-based quantitative measurement of the through thickness residual stress distribution is very limited in literature. The deep penetration capability of neutrons into most metallic materials makes neutron diffraction a powerful tool to investigate and map the residual stresses of materials throughout the thickness and across the weld. Furthermore, the unique volume averaged bulk characteristic of materials and mapping capability in three dimensions are suitable for the engineering purpose. Thus, the neutron-diffraction measurement method has been selected as the most useful method for the study of the residual stresses in various dissimilar metal welded structures. The purpose of this study is to measure the distribution of the residual stresses in a complex dissimilar joining with overlay in the weld pipe. Specifically, we measured

  3. Central corneal thickness and anterior chamber depth measurement by Sirius® Scheimpflug tomography and ultrasound

    Directory of Open Access Journals (Sweden)

    Jorge J

    2013-02-01

    Full Text Available J Jorge,1 JL Rosado,2 JA Díaz-Rey,1 JM González-Méijome11Clinical and Experimental Optometry Research Laboratory, Center of Physics (Optometry, School of Sciences, University of Minho, Braga, 2Opticlinic, Lisboa, PortugalBackground: The purpose of this study was to compare the accuracy of the new Sirius® Scheimpflug anterior segment examination device for measurement of central corneal thickness (CCT and anterior chamber depth (ACD with that of CCT measurements obtained by ultrasound pachymetry and ACD measurements obtained by ultrasound biometry, respectively.Methods: CCT and ACD was measured in 50 right eyes from 50 healthy subjects using a Sirius Scheimpflug camera, SP100 ultrasound pachymetry, and US800 ultrasound biometry.Results: CCT measured with the Sirius was 546 ± 39 µm and 541 ± 35 µm with SP100 ultrasound pachymetry (P = 0.003. The difference was statistically significant (mean difference 4.68 ± 10.5 µm; limits of agreement −15.8 to 25.20 µm. ACD measured with the Sirius was 2.96 ± 0.3 mm compared with 3.36 ± 0.29 mm using US800 ultrasound biometry (P < 0.001. The difference was statistically significant (mean difference −0.40 ± 0.16 mm; limits of agreement −0.72 to 0.07 mm. When the ACD values obtained using ultrasound biometry were corrected according to the values for CCT measured by ultrasound, the agreement increased significantly between both technologies for ACD measurements (mean difference 0.15 ± 0.16 mm; limits of agreement −0.16 to 0.45 mm.Conclusion: CCT and ACD measured by Sirius and ultrasound methods showing good agreement between repeated measurements obtained in the same subjects (repeatability with either instrument. However, CCT and ACD values, even after correcting ultrasound ACD by subtracting the CCT value obtained with either technology should not be used interchangeably.Keywords: Scheimpflug corneal tomography, ultrasound biometry, ultrasound pachymetry, limits of agreement

  4. Imaging regenerating bone tissue based on neural networks applied to micro-diffraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Campi, G.; Pezzotti, G. [Institute of Crystallography, CNR, via Salaria Km 29.300, I-00015, Monterotondo Roma (Italy); Fratini, M. [Centro Fermi -Museo Storico della Fisica e Centro Studi e Ricerche ' Enrico Fermi' , Roma (Italy); Ricci, A. [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg (Germany); Burghammer, M. [European Synchrotron Radiation Facility, B. P. 220, F-38043 Grenoble Cedex (France); Cancedda, R.; Mastrogiacomo, M. [Istituto Nazionale per la Ricerca sul Cancro, and Dipartimento di Medicina Sperimentale dell' Università di Genova and AUO San Martino Istituto Nazionale per la Ricerca sul Cancro, Largo R. Benzi 10, 16132, Genova (Italy); Bukreeva, I.; Cedola, A. [Institute for Chemical and Physical Process, CNR, c/o Physics Dep. at Sapienza University, P-le A. Moro 5, 00185, Roma (Italy)

    2013-12-16

    We monitored bone regeneration in a tissue engineering approach. To visualize and understand the structural evolution, the samples have been measured by X-ray micro-diffraction. We find that bone tissue regeneration proceeds through a multi-step mechanism, each step providing a specific diffraction signal. The large amount of data have been classified according to their structure and associated to the process they came from combining Neural Networks algorithms with least square pattern analysis. In this way, we obtain spatial maps of the different components of the tissues visualizing the complex kinetic at the base of the bone regeneration.

  5. Standardization of choroidal thickness measurements using enhanced depth imaging optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    Nattapon; Boonarpha; Yalin; Zheng; Alexandros; N.Stangos; Huiqi; Lu; Ankur; Raj; Gabriela; Czanner; Simon; P.Harding; Jayashree; Nair-Sahni

    2015-01-01

    AIM: To describe and evaluate a standardized protocol for measuring the choroidal thickness(Ch T) using enhanced depth imaging optical coherence tomography(EDI OCT).METHODS: Single 9 mm EDI OCT line scans across the fovea were used for this study. The protocol used in this study classified the EDI OCT images into four groups based on the appearance of the choroidal-scleral interface and suprachoroidal space. Two evaluation iterations of experiments were performed: first, the protocol was validated in a pilot study of 12 healthy eyes. Afterwards, the applicability of the protocol was tested in 82 eyes of patients with diabetes. Inter-observer and intra-observer agreements on image classifications were performed using Cohen’s kappa coefficient(κ). Intraclass correlation coefficient(ICC) and Bland-Altman’s methodology were used for the measurement of the Ch T.RESULTS: There was a moderate(κ=0.42) and perfect(κ =1) inter- and intra-observer agreements on image classifications from healthy eyes images and substantial(κ =0.66) and almost perfect(κ =0.86) agreements from diabetic eyes images. The proposed protocol showed excellent inter- and intra-observer agreements for the Ch T measurements on both, healthy eyes and diabetic eyes(ICC >0.90 in all image categories). The Bland-Altman plot showed a relatively large Ch T measurement agreement in the scans that contained less visible choroidal outer boundary. CONCLUSION: A protocol to standardize Ch T measurements in EDI OCT images has been developed;the results obtained using this protocol show that the technique is accurate and reliable for routine clinical practice and research.

  6. Body composition and bone mineral density measurements by using a multi-energy method

    International Nuclear Information System (INIS)

    Dual-energy X-ray absorptiometry is a major technique to evaluate bone mineral density, thus allowing diagnosis of bone decalcification ( osteoporosis). Recently, this method has proved useful to quantify body composition (fat ratio). However, these measurements suffer from artefacts which can lead to diagnosis errors in a number of cases. This work has aimed to improve both the reproducibility and the accuracy of bone mineral density and body composition measurements. To this avail, the acquisition conditions were optimised in order to ameliorate the results reproducibility and we have proposed a new method to correct inaccuracies in the determination of bone mineral density. Experimental validations yield encouraging results on both synthetic phantoms and biological samples. (author)

  7. An in vivo technique for the measurement of bone blood flow in animals

    International Nuclear Information System (INIS)

    A new technique to measure the in vivo clearance of 41Ar from the bone mineral matrix is demonstrated following fast neutron production of 41Ar in bone via the 44Ca(n,α) reaction at 14.1 MeV. At the end of irradiation, the 41Ar activity is assayed with a Ge(Li) detector where sequential gamma-ray spectra are taken. Following full-energy peak integration, background and dead time correction, the activity of 41Ar as a function of time is determined. Results indicated that the Ar washout from bone in rats using this technique was approximately 16 ml (100 ml min)-1 and in agreement with other measurement techniques. For sheep the bone perfusion in the tibia was approximately 1.9+-0.2 ml (100 ml min)-1. (author)

  8. Clinical Factors Associated with Lamina Cribrosa Thickness in Patients with Glaucoma, as Measured with Swept Source Optical Coherence Tomography

    Science.gov (United States)

    Omodaka, Kazuko; Takahashi, Seri; Matsumoto, Akiko; Maekawa, Shigeto; Kikawa, Tsutomu; Himori, Noriko; Takahashi, Hidetoshi; Maruyama, Kazuichi; Kunikata, Hiroshi; Akiba, Masahiro; Nakazawa, Toru

    2016-01-01

    Purpose To investigate the influence of various risk factors on thinning of the lamina cribrosa (LC), as measured with swept-source optical coherence tomography (SS-OCT; Topcon). Methods This retrospective study comprised 150 eyes of 150 patients: 22 normal subjects, 28 preperimetric glaucoma (PPG) patients, and 100 open-angle glaucoma patients. Average LC thickness was determined in a 3 x 3 mm cube scan of the optic disc, over which a 4 x 4 grid of 16 points was superimposed (interpoint distance: 175 μm), centered on the circular Bruch’s membrane opening. The borders of the LC were defined as the visible limits of the LC pores. The correlation of LC thickness with Humphrey field analyzer-measured mean deviation (MD; SITA standard 24–2), circumpapillary retinal nerve fiber layer thickness (cpRNFLT), the vertical cup-to-disc (C/D) ratio, and tissue mean blur rate (MBR) was determined with Spearman's rank correlation coefficient. The relationship of LC thickness with age, axial length, intraocular pressure (IOP), MD, the vertical C/D ratio, central corneal thickness (CCT), and tissue MBR was determined with multiple regression analysis. Average LC thickness and the correlation between LC thickness and MD were compared in patients with the glaucomatous enlargement (GE) optic disc type and those with non-GE disc types, as classified with Nicolela’s method. Results We found that average LC thickness in the 16 grid points was significantly associated with overall LC thickness (r = 0.77, P Glaucoma patients with the GE disc type, who predominantly have large cupping, had lower LC thickness even with similar glaucoma severity. PMID:27100404

  9. Natural Ca Isotope Composition of Urine as a Rapid Measure of Bone Mineral Balance

    Science.gov (United States)

    Skulan, J.; Gordon, G. W.; Morgan, J.; Romaniello, S. J.; Smith, S. M.; Anbar, A. D.

    2011-12-01

    Naturally occurring stable Ca isotope variations in urine are emerging as a powerful tool to detect changes in bone mineral balance. Bone formation depletes soft tissue of light Ca isotopes while bone resorption releases isotopically light Ca into soft tissue. Previously published work found that variations in Ca isotope composition could be detected at 4 weeks of bed rest in a 90-day bed rest study (data collected at 4, 8 and 12 weeks). A new 30-day bed rest study involved 12 patients on a controlled diet, monitored for 7 days prior to bed rest and 7 days post bed rest. Samples of urine, blood and food were collected throughout the study. Four times daily blood samples and per void urine samples were collected to monitor diurnal or high frequency variations. An improved chemical purification protocol, followed by measurement using multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) allowed accurate and precise determinations of mass-dependent Ca isotope variations in these biological samples to better than ±0.2% (δ44/42Ca) on alkaline phosphatase, a bone formation biomarker, is unchanged over this period. Ca isotopes can in principle be used to quantify net changes in bone mass. Using a mass-balance model, our results indicate an average loss of 0.62 ± 0.16 % in bone mass over the course of this 30-day study. This is consistent with the rate of bone loss in longer-term studies as seen by X-ray measurements. This Ca isotope technique should accelerate the pace of discovery of new treatments for bone disease and provide novel insights into the dynamics of bone metabolism.

  10. Design and Validation of Automated Femoral Bone Morphology Measurements in Cerebral Palsy

    OpenAIRE

    Park, Noyeol; Lee, Jehee; Sung, Ki Hyuk; Park, Moon Seok; Koo, Seungbum

    2013-01-01

    Accurate quantification of bone morphology is important for monitoring the progress of bony deformation in patients with cerebral palsy. The purpose of the study was to develop an automatic bone morphology measurement method using one or two radiographs. The study focused on four morphologic measurements—neck-shaft angle, femoral anteversion, shaft bowing angle, and neck length. Fifty-four three-dimensional (3D) geometrical femur models were generated from the computed tomography (CT) of cere...

  11. MODIFIED LAYER REMOVAL METHOD FOR MEASUREMENT OF RESIDUAL STRESS DISTRIBUTION IN THICK PRE-STRETCHED ALUMINUM PLATE

    Institute of Scientific and Technical Information of China (English)

    WANGShu-hong; ZUODun-wen; WANGMin; WANGZong-rong

    2004-01-01

    The integrated structure parts are widely used in aircraft. The distortion caused by residual stresses in thick pre-stretched aluminum plates during machining integrated parts is a common and serious problem. To predict and control the machining distortion, the residual stress distribution in the thick plate must be measured firstly. The modified removal method for measuring residual stress in thick pre-stretched aluminum plates is proposed and the stress-strain relation matrix is deduced by elasticity theory. The residual stress distribution in specimen of 7050T7451 plate is measured by using the method, and measurement results are analyzed and compared with data obtained by other methods. The method is effective to measure the residual stress.

  12. Genetic network properties of the human cortex based on regional thickness and surface area measures

    Directory of Open Access Journals (Sweden)

    Anna R. Docherty

    2015-08-01

    Full Text Available We examined network properties of genetic covariance between average cortical thickness (CT and surface area (SA within genetically-identified cortical parcellations that we previously derived from human cortical genetic maps using vertex-wise fuzzy clustering analysis with high spatial resolution. There were 24 hierarchical parcellations based on vertex-wise CT and 24 based on vertex-wise SA expansion/contraction; in both cases the 12 parcellations per hemisphere were largely symmetrical. We utilized three techniques—biometrical genetic modeling, cluster analysis, and graph theory—to examine genetic relationships and network properties within and between the 48 parcellation measures. Biometrical modeling indicated significant shared genetic covariance between size of several of the genetic parcellations. Cluster analysis suggested small distinct groupings of genetic covariance; networks highlighted several significant negative and positive genetic correlations between bilateral parcellations. Graph theoretical analysis suggested that small world, but not rich club, network properties may characterize the genetic relationships between these regional size measures. These findings suggest that cortical genetic parcellations exhibit short characteristic path lengths across a broad network of connections. This property may be protective against network failure. In contrast, previous research with structural data has observed strong rich club properties with tightly interconnected hub networks. Future studies of these genetic networks might provide powerful phenotypes for genetic studies of normal and pathological brain development, aging, and function.

  13. Validation of UV-visible aerosol optical thickness retrieved from spectroradiometer measurements

    Directory of Open Access Journals (Sweden)

    C. Brogniez

    2008-02-01

    Full Text Available Global and diffuse UV-visible solar irradiances are routinely measured since 2003 with a spectroradiometer operated by the Laboratoire d'Optique Atmosphérique (LOA located in Villeneuve d'Ascq, France. The analysis of the direct irradiance derived by cloudless conditions enables retrieving the aerosol optical thickness (AOT spectrum in the 330–450 nm range. The site hosts also sunphotometers from the AERONET/PHOTONS network performing routinely measurements of the AOT at several wavelengths. On one hand, comparisons between the spectroradiometer and the sunphotometer AOT at 440 nm as well as, when available, at 340 and 380 nm, show good agreement. On the other hand, the AOT's spectral variations have been compared using the Angström exponents derived from AOT data at 340 and 440 nm for both instruments. The comparisons show that this parameter is difficult to retrieve accurately due to the small wavelength range and due to the weak AOT values. Thus, AOT derived at wavelengths outside the spectroradiometer range by means of an extrapolation using the Angström parameter would be of poor value, whereas, spectroradiometer's spectral AOT could be used for direct validation of other AOT, such as those provided by satellite instruments.

  14. Improved retrieval of aerosol optical thickness from MODIS measurements through derived surface reflectance over Nanjing, China

    Energy Technology Data Exchange (ETDEWEB)

    Yong, Zha; Jianjun, Jiang; Heng, Lu; Jiazhu, Huang (Key Laboratory of Virtual Geographic Environment, Ministry of Education, College of Geographic Science, Nanjing Normal Univ., Nanjing (China)), e-mail: yzha@njnu.edu.cn; Qiao, Wang (Satellite Environment Center, Ministry of Environmental Protection, Beijing (China)); Jie, Yuan (Shaanxi Bureau of Surveying and Mapping, Xian (China)); Jay, Gao (School of Geography, Geology and Environmental Science, Univ. of Auckland, Auckland (New Zealand))

    2011-11-15

    Determination of surface reflectance in the red and blue channels is a critical step in retrieving aerosol optical thickness (AOT) from Moderate Resolution Imaging Spectroradiometer (MODIS) measurements. The MODIS Collection 005 (C005) aerosol algorithm uses a ratio method to determine the surface reflectance in the red (0.66 mum) and blue (0.47 mum) channels from the surface reflectance in the 2.1 mum channel using global surface reflectance relationships. In this study, we attempted to improve the retrieval of AOT from MODIS measurements using a new surface parameterization derived using ground-based sunphotometer data and 6S radiative transfer code. The estimated surface reflectance in the red, blue and near-IR channel were used to derive ratio between them for use in the new retrieval from MODIS data. Our results demonstrate that the ratio of surface reflectance in the red and blue channels to the surface reflectance in the 2.1 mum channel varies seasonally in the Xianlin district of Nanjing City, China. These ratios are different from those assumed by the MODIS aerosol algorithm for the retrieval of AOT over land. The use of the appropriate ratio for the study area in a given season significantly improves the accuracy with the absolute error decreased from 0.15 to 0.08 and the relative error reduced from 31% to 17% in retrieving AOT from MODIS data

  15. Genetic network properties of the human cortex based on regional thickness and surface area measures.

    Science.gov (United States)

    Docherty, Anna R; Sawyers, Chelsea K; Panizzon, Matthew S; Neale, Michael C; Eyler, Lisa T; Fennema-Notestine, Christine; Franz, Carol E; Chen, Chi-Hua; McEvoy, Linda K; Verhulst, Brad; Tsuang, Ming T; Kremen, William S

    2015-01-01

    We examined network properties of genetic covariance between average cortical thickness (CT) and surface area (SA) within genetically-identified cortical parcellations that we previously derived from human cortical genetic maps using vertex-wise fuzzy clustering analysis with high spatial resolution. There were 24 hierarchical parcellations based on vertex-wise CT and 24 based on vertex-wise SA expansion/contraction; in both cases the 12 parcellations per hemisphere were largely symmetrical. We utilized three techniques-biometrical genetic modeling, cluster analysis, and graph theory-to examine genetic relationships and network properties within and between the 48 parcellation measures. Biometrical modeling indicated significant shared genetic covariance between size of several of the genetic parcellations. Cluster analysis suggested small distinct groupings of genetic covariance; networks highlighted several significant negative and positive genetic correlations between bilateral parcellations. Graph theoretical analysis suggested that small world, but not rich club, network properties may characterize the genetic relationships between these regional size measures. These findings suggest that cortical genetic parcellations exhibit short characteristic path lengths across a broad network of connections. This property may be protective against network failure. In contrast, previous research with structural data has observed strong rich club properties with tightly interconnected hub networks. Future studies of these genetic networks might provide powerful phenotypes for genetic studies of normal and pathological brain development, aging, and function. PMID:26347632

  16. Subfoveal choroidal thickness measured by Cirrus HD optical coherence tomography in myopia

    Directory of Open Access Journals (Sweden)

    Li-Li Chen

    2014-09-01

    Full Text Available ATM: To measure the subfoveal choroidal thickness(SFCTin myopia using Cirrus HD optical coherence tomography(OCT, and to explore the relationship between the SFCT, axial length and myopic refractive spherical equivalent.METHODS: One-hundred thirty-three eyes of 70 healthy volunteers were recruited, and were divided into emmetropia group, low-degree myopia, middle-degree myopia and high-degree myopia group. SFCT were measured by Cirrus HD OCT, and the relationship between the SFCT, axial length and myopic refractive spherical equivalent were evaluated.RESULTS: 1Average SFCT was(275.91±55.74μm in normals, that in emmetropia group, low-degree myopia, middle-degree myopia and high-degree myopia group were(290.03±34.82μm,(287.64±51.51μm,(274.95±56.83μm,(248.37±67.98μm; 2the SFCT of high-degree myopia group was significant thinner than that of emmetropia group(PPPCONCLUSION: the SFCT is inversely correlated with increasing axial length and myopic refractive error.

  17. Association between Anthropometric Measures and Bone Mineral Density: Population-Based Study

    Directory of Open Access Journals (Sweden)

    HR Aghaei Meybodi

    2011-06-01

    Full Text Available "nBackground: Osteoporosis is a major public health concern around the world. It has been shown that bone mineral den­sity is correlated to anthropometric measures like height and weight, but this association may vary depending on ethnic and environmental factors. The aim of this study was to identify probable relations between anthropometric measures and bone mineral density."nMethods: In this population-based study, we compiled the data collected from Iranian Multicenter Osteoporosis Study to assess the possible associations between different anthropometric indices and bone mineral density at femur and lumbar spine. The gathered data was analyzed using t-test and one way ANOVA."nResults: Data was available for 4445 subjects, consisting 1900 males (42.7% and 2545 females (57.3%. We observed statistically significant correlations between bone mineral density and height, weight, waist circumference, hip circumfer­ence, waist to hip ratio and body mass index (BMI. Based on the result of linear regression modeling studies, BMI could be considered an independent predictor of bone mineral density."nConclusion: Iranian population shows similar measures compared to analogous studies in other populations. Lower weight should be carefully considered as a predisposing factor for bone loss and osteoporosis.

  18. Extracting accurate strain measurements in bone mechanics: A critical review of current methods.

    Science.gov (United States)

    Grassi, Lorenzo; Isaksson, Hanna

    2015-10-01

    Osteoporosis related fractures are a social burden that advocates for more accurate fracture prediction methods. Mechanistic methods, e.g. finite element models, have been proposed as a tool to better predict bone mechanical behaviour and strength. However, there is little consensus about the optimal constitutive law to describe bone as a material. Extracting reliable and relevant strain data from experimental tests is of fundamental importance to better understand bone mechanical properties, and to validate numerical models. Several techniques have been used to measure strain in experimental mechanics, with substantial differences in terms of accuracy, precision, time- and length-scale. Each technique presents upsides and downsides that must be carefully evaluated when designing the experiment. Moreover, additional complexities are often encountered when applying such strain measurement techniques to bone, due to its complex composite structure. This review of literature examined the four most commonly adopted methods for strain measurements (strain gauges, fibre Bragg grating sensors, digital image correlation, and digital volume correlation), with a focus on studies with bone as a substrate material, at the organ and tissue level. For each of them the working principles, a summary of the main applications to bone mechanics at the organ- and tissue-level, and a list of pros and cons are provided. PMID:26099201

  19. Bone densitometry by gamma ray attenuation measurement. Development of an apparatus for use on medullary casualties

    International Nuclear Information System (INIS)

    We proposed to follow changes in the bone mineral content of medullary damage cases by measuring the attenuation of a monoenergetic gamma ray according to the Cameron and Sorenson technique. Apart from their high cost, existing instruments are not designed for this bedside observation of patients. Our aim was therefore to design and develop an easily portable, inexpensive apparatus. The γ radiation is supplied by a sealed 125I source fitted with a narrow collimator. The battery-operated scintillation detector is that used to detect post-operative phlebites after injection of radio-fibrinogen. The source-detector unit can move to allow a transverse bone mineral content measurement. Data from the detector are processed electronically and the results given: - either graphically on a tracing board which gives an area proportional to the bone mineral content, - or numerically by means of an integrator computing this area and supplying the linear bone density directly. Experiments carried out in vivo showed the apparatus to be sensitive and the measurements reproducible, the results obtained being comparable with those of other authors. Using pieces of embalmed bone moreover an excellent correlation was observed between the bone mineral content obtained after incineration and the results displayed by our apparatus, which can therefore be calibrated

  20. Autoradiography of lyophilized animal sections. Bone density measurement in osteoporosis model rats

    International Nuclear Information System (INIS)

    To gain a better understanding on the β-ray radiography of lyophilized animal sections, the bone densities of the osteoporosis rats were measured using a 147Pm planar radiation source. An imaging plate as a radiation sensor was overlaid on the animal section together with a density calibrator. After exposure, radioactivity recorded on the sensor was quantified using a bio-imaging analyzer. The density calibration curve showed linearity in the wide range with a good correlation coefficient (R2≥0.999). The inter- and intra-plate variability showed CV values less than 3.7%. On the measurement of bone density, bone density differences between the sham group and ovariectomized (OVX) group were statistically significant in the femoral cortical (p=0.001) and trabecular bone (p=0.07), and vertebral trabecular bone (p=0.043). Based on these results, we developed a new and valuable method, which made it possible to measure bone density of axial skeleton of a rat, as an alternative to commonly used methods. (author)

  1. Metamaterial near-field sensor for deep-subwavelength thickness measurements and sensitive refractometry in the terahertz frequency range

    CERN Document Server

    Reinhard, Benjamin; Wollrab, Viktoria; Neu, Jens; Beigang, René; Rahm, Marco

    2012-01-01

    We present a metamaterial-based terahertz (THz) sensor for thickness measurements of subwavelength-thin materials and refractometry of liquids and liquid mixtures. The sensor operates in reflection geometry and exploits the frequency shift of a sharp Fano resonance minimum in the presence of dielectric materials. We obtained a minimum thickness resolution of 12.5 nm (1/16000 times the wavelength of the THz radiation) and a refractive index sensitivity of 0.43 THz per refractive index unit. We support the experimental results by an analytical model that describes the dependence of the resonance frequency on the sample material thickness and the refractive index.

  2. Metamaterial near-field sensor for deep-subwavelength thickness measurements and sensitive refractometry in the terahertz frequency range

    Energy Technology Data Exchange (ETDEWEB)

    Reinhard, Benjamin; Schmitt, Klemens M.; Neu, Jens [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern (Germany); Wollrab, Viktoria; Beigang, Rene; Rahm, Marco [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern (Germany); Fraunhofer Institute for Physical Measurement Techniques IPM, 79110 Freiburg (Germany)

    2012-05-28

    We present a metamaterial-based terahertz (THz) sensor for thickness measurements of subwavelength-thin materials and refractometry of liquids and liquid mixtures. The sensor operates in reflection geometry and exploits the frequency shift of a sharp Fano resonance minimum in the presence of dielectric materials. We obtained a minimum thickness resolution of 12.5 nm (1/16 000 times the wavelength of the THz radiation) and a refractive index sensitivity of 0.43 THz per refractive index unit. We support the experimental results by an analytical model that describes the dependence of the resonance frequency on the sample material thickness and the refractive index.

  3. Skin thickness effects on in vivo LXRF

    International Nuclear Information System (INIS)

    The analysis of lead concentration in bone utilizing LXRF can be adversely effected by overlying issue. A quantitative measure of the attenuation of the 10.5 keV Pb L a x-ray signal by skin and skin equivalent plastic has been conducted. Concentration ranges in plaster of Paris and goat bone from 7 to 90 ppm with attenuators of Lucite reg-sign and pig skin were examined. It is concluded that no quantitative or semi quantitative analysis can be achieved if overlying sue thickness exceeds 3 mm for Ph concentrations of less than 30 porn Ph in bone

  4. Measurement of Specimen Thickness by Using Electron Holography and Electron Dynamic Calculation with a Transmission Electron Microscope

    Institute of Scientific and Technical Information of China (English)

    王岩国; 刘红荣; 杨奇斌; 张泽

    2003-01-01

    A method of transmission-electron microscopy for accurate measurement of specimen thickness has been proposed based on off-axis electron holography along with the dynamic electron diffraction simulation. The phase shift of the exit object wave with respect to the reference wave in vacuum, resulting from the scattering within the specimen, has been simulated versus the specimen thickness by the dynamic electron diffraction formula. Offaxis electron holography in a field emission gun transmission-electron microscope has been used to determine the phase shift of the exit wave. The specimen thickness can be obtained by match of the experimental and simulated phase shift. Based on the measured phase shift of the [110] oriented copper foil, the thickness can be determined at a good level of accuracy with an error less than ~10%.

  5. Measurement of bone mineral density using DEXA and biochemical markers of bone turnover in 5-year survivors after orthotopic liver transplantation

    International Nuclear Information System (INIS)

    Purpose: To observe bone loss and bone metabolism status in 5-year survivors after orthotopic liver transplantation (OLT). Methods: Measurement of bone mineral density (BMD) of the lumbar spine (L2∼L4) and femoral neck using dual energy X-ray absorptiometry (DEXA) and analysis of biochemical markers of bone turnover, such as ostecalcin (OSC), bone alkaline phosphatase (BAP), carboxy-terminal propeptide of type I procollagen (PICP), carboxy-terminal cross-linked telo-peptide of type I collagen (ICTP), PTH and 25-hydroxy-vitamin D (25-OH-D). These markers were measured in 31 5-year survivors after OLT, 34 patients with chronic liver failure (CLF) before OLT and 38 normal subjects. Results: Age-matched Z-score of BMD (Z-score) at L2∼L4 was significantly higher in 5-year survivors than that in patients with CLF before OLT. Incidence of osteoporosis (Z-score<-2.0) in 5-year survivors was significantly lower than that in patients with CLF before OLT. Although serum concentrations of bone formation and bone resorption markers in 5-year survivors were high than those of normal subjects, as compared to patients with CLF before OLT, serum OSC was increased, serum ICTP and BAP were reduced, serum PICP was unchanged. Serum PTH and 25-OH-D level was normal. Conclusions: In 5-year survivors following liver transplantation there was a reduction in bone loss and incidence of osteoporosis and an improvement of bone metabolism

  6. Metamaterial near-field sensor for deep-subwavelength thickness measurements and sensitive refractometry in the terahertz frequency range

    OpenAIRE

    Reinhard, Benjamin; Schmitt, Klemens M.; Wollrab, Viktoria; Neu, Jens; Beigang, René; Rahm, Marco

    2012-01-01

    We present a metamaterial-based terahertz (THz) sensor for thickness measurements of subwavelength-thin materials and refractometry of liquids and liquid mixtures. The sensor operates in reflection geometry and exploits the frequency shift of a sharp Fano resonance minimum in the presence of dielectric materials. We obtained a minimum thickness resolution of 12.5 nm (1/16000 times the wavelength of the THz radiation) and a refractive index sensitivity of 0.43 THz per refractive index unit. We...

  7. Impact of Processing Conditions on Inter-tablet Coating Thickness Variations Measured by Terahertz In-Line Sensing

    OpenAIRE

    Lin, Hungyen; May, Robert K; Evans, Michael J.; Zhong, Shuncong; Gladden, Lynn F; Shen, Yaochun; Zeitler, J Axel

    2015-01-01

    A novel in-line technique utilising pulsed terahertz radiation for direct measurement of the film coating thickness of individual tablets during the coating process was previously developed and demonstrated on a production-scale coater. Here, we use this technique to monitor the evolution of tablet film coating thickness and its inter-tablet variability during the coating process under a number of different process conditions that have been purposefully induced in the production-scale coating...

  8. Effect of micro-computed tomography voxel size and segmentation method on trabecular bone microstructure measures in mice.

    Science.gov (United States)

    Christiansen, Blaine A

    2016-12-01

    Micro-computed tomography (μCT) is currently the gold standard for determining trabecular bone microstructure in small animal models. Numerous parameters associated with scanning and evaluation of μCT scans can strongly affect morphologic results obtained from bone samples. However, the effect of these parameters on specific trabecular bone outcomes is not well understood. This study investigated the effect of μCT scanning with nominal voxel sizes between 6-30 μm on trabecular bone outcomes quantified in mouse vertebral body trabecular bone. Additionally, two methods for determining a global segmentation threshold were compared: based on qualitative assessment of 2D images, or based on quantitative assessment of image histograms. It was found that nominal voxel size had a strong effect on several commonly reported trabecular bone parameters, in particular connectivity density, trabecular thickness, and bone tissue mineral density. Additionally, the two segmentation methods provided similar trabecular bone outcomes for scans with small nominal voxel sizes, but considerably different outcomes for scans with larger voxel sizes. The Qualitatively Selected segmentation method more consistently estimated trabecular bone volume fraction (BV/TV) and trabecular thickness across different voxel sizes, but the Histogram segmentation method more consistently estimated trabecular number, trabecular separation, and structure model index. Altogether, these results suggest that high-resolution scans be used whenever possible to provide the most accurate estimation of trabecular bone microstructure, and that the limitations of accurately determining trabecular bone outcomes should be considered when selecting scan parameters and making conclusions about inter-group variance or between-group differences in studies of trabecular bone microstructure in small animals. PMID:27430011

  9. Measurement of absorbed dose with a bone-equivalent extrapolation chamber

    International Nuclear Information System (INIS)

    A hybrid phantom-embedded extrapolation chamber (PEEC) made of Solid Water trade mark sign and bone-equivalent material was used for determining absorbed dose in a bone-equivalent phantom irradiated with clinical radiation beams (cobalt-60 gamma rays; 6 and 18 MV x rays; and 9 and 15 MeV electrons). The dose was determined with the Spencer-Attix cavity theory, using ionization gradient measurements and an indirect determination of the chamber air-mass through measurements of chamber capacitance. The collected charge was corrected for ionic recombination and diffusion in the chamber air volume following the standard two-voltage technique. Due to the hybrid chamber design, correction factors accounting for scatter deficit and electrode composition were determined and applied in the dose equation to obtain absorbed dose in bone for the equivalent homogeneous bone phantom. Correction factors for graphite electrodes were calculated with Monte Carlo techniques and the calculated results were verified through relative air cavity dose measurements for three different polarizing electrode materials: graphite, steel, and brass in conjunction with a graphite collecting electrode. Scatter deficit, due mainly to loss of lateral scatter in the hybrid chamber, reduces the dose to the air cavity in the hybrid PEEC in comparison with full bone PEEC by 0.7% to ∼2% depending on beam quality and energy. In megavoltage photon and electron beams, graphite electrodes do not affect the dose measurement in the Solid Water trade mark sign PEEC but decrease the cavity dose by up to 5% in the bone-equivalent PEEC even for very thin graphite electrodes (<0.0025 cm). In conjunction with appropriate correction factors determined with Monte Carlo techniques, the uncalibrated hybrid PEEC can be used for measuring absorbed dose in bone material to within 2% for high-energy photon and electron beams

  10. Ultrasonic Water Thickness Measurement at a Gas-Liquid Interface Area in Full-scale Mockup Experiment

    International Nuclear Information System (INIS)

    The ultrasonic pre-examination in the mockup condition was performed to do an analysis for cooling performance in a complete test channel by the investigation of the two-phase flow that will be developed in an inclined gap with heating from the top. This ultrasonic technique for measuring water layer thickness measurement employs the higher relative acoustic impedance of air with respect to that of liquids. By this method it is possible to determine both liquid water distance, void fraction in a gas-liquid two-phase flow. Instantaneous measurement of the water layer thickness is useful in understanding heat and mass transfer characteristics in a two-phase separated flow. An ultrasonic measurement technique for determining water layer thickness in the wavy and slug flow regime of horizontal tube flow has been produced as an A-scan mode and B-scan mode

  11. Validation of K-XRF bone lead measurement in young adults.

    OpenAIRE

    Hoppin, J.A.; Aro, A C; Williams, P L; Hu, H; Ryan, P B

    1995-01-01

    K-X-ray fluorescence (K-XRF) is a useful tool for assessing environmental exposure to lead in occupationally exposed individuals and older adults. This study explores the possibility of using this technique on young adults with low environmental lead exposure. Twenty-three college students, aged 18-21 years, were recruited for 2 hr of bone lead measurement. Bone lead measurements were taken from the mid-shaft tibia for periods of 30 or 60 min. In the analysis, 30-min measurements were combine...

  12. Measurements of RRR and thickness on thin Cu-plating used for input couplers in superconducting cavities

    International Nuclear Information System (INIS)

    Input coupler for superconducting cavities is required high electrical conductivity and low thermal conductivity. To satisfy both of opposite properties, the input coupler made by copper plated stainless steal are under developing. To find the best condition for the Cu plating, we measured RRR (Residual Resistivity Ratio) and thickness of the Cu plating of several samples. From the results of RRR measurement and thickness measurement we found influence of heat treatment for the RRR and how to avoid decreasing of the RRR from the heat treatment. (author)

  13. New developments in the analysis and measurement of thicknesses by excitation of the fluorescent lines by means of β particles

    International Nuclear Information System (INIS)

    The process for analysing and measuring the thickness of deposits by β-X fluorescence which we have already described has undergone further development. The use of promethium-147 and krypton-85 sources makes it possible to reduce the background noise which is observed with strontium-90. We present the results obtained for various measurements of the thickness of metallic coatings and the continuous measurement of calcium and of iron in ore samples. We describe the tests carried out with a view to analysing the X-rays by means of a crystal. (author)

  14. Wall Thickness Measurement Of Insulated Pipe By Tangential Radiography Technique Using Ir 192

    International Nuclear Information System (INIS)

    Insulation pipe wall thickness by tangential radiography technique has been carried out using 41 Curie Iridium 192 source has activity for two carbon steel pipes. The outer diameter of the first pipe is 90 mm, wall thickness is 75.0 mm, source film film distance is 609.5 mm, source tangential point of insulation is 489.5 mm and exposure time 3 minute and 25 second. From the calculation, the first pipe thickness is found to be 12.54 mm and for the second pipe is 8.42 mm. The thickness is due to inaccuracy in reading the pipe thickness on radiography film and the geometry distortion radiation path

  15. Evaluation of MR, CT and ultrasound imaging modalities for estimation of finger soft-tissue thickness: efforts to improve normalization of in vivo strontium X-ray fluorescence measurements

    International Nuclear Information System (INIS)

    Full text: The measuring of strontium content in bone using energy dispersive X-ray fluorescence spectroscopy (EDXRF) is hindered by overlying skin and soft-tissue absorption of the strontium X-rays. Knowing the overlying soft-tissue thickness at the index finger measuring site might allow for normalization of the strontium reading to estimate concentration in bone quantitatively. Previous imaging attempts, using 12 MHz ultrasound, significantly underestimated the true finger tissue thickness. Seven cadaver fingers were imaged using magnetic resonance (MR), computerized tomography (CT) and 12, 25 and 55 MHz ultrasound modalities to compare efficacies of providing an accurate estimate of finger soft-tissue thickness. MR provided high differentiation of soft tissues but had lower resolution at 160 μm to allow for realistically feasible scan time. X-ray CT image acquisition time was quick producing a 50 μm resolution but moderate to low tissue differentiation. Ultrasound produced moderate tissue differentiation with resolution at 100 μm using a 55 MHz transducer, 150 μm using a 25 MHz and 200 μm using a 12 MHz transducer. (Insert soon-to-follow cross-examination results of tissue thickness estimates for each of the 3 modalities. These modalities will be compared against histological cross-sections of the fingers themselves at the measurement site.) Several factors including: image quality, soft tissue information, image acquisition time, modality availability, cost to implement and dose to patient will be considered for prospective implementation of an in-vivo strontium measurement protocol to determine quantitative Sr concentration in bone

  16. Flexible tactile sensor for shear stress measurement using transferred sub-µm-thick Si piezoresistive cantilevers

    International Nuclear Information System (INIS)

    We propose a flexible tactile sensor using sub-µm-thick Si piezoresistive cantilevers for shear stress detection. The thin Si piezoresistive cantilevers were fabricated on the device layer of a silicon on insulator (SOI) wafer. By using an adhesion-based transfer method, only these thin and fragile cantilevers were transferred from the rigid handling layer of the SOI wafer to the polydimethylsiloxane layer without damage. Because the thin Si cantilevers have high durability of bending, the proposed sensor can be attached to a thin rod-type structure serving as the finger of a robotic hand. The cantilevers were arrayed in orthogonal directions to measure the X and Y directional components of applied shear stresses independently. We evaluated the bending durability of our flexible tactile sensor and confirmed that the sensor can be attached to a rod with a radius of 10 mm. The sensitivity of the flexible tactile sensor attached to a curved surface was 1.7 × 10−6 Pa−1 on average for a range of shear stresses from −1.8 × 103 to 1.8 × 103 Pa applied along its surface. It independently detected the X and Y directional components of the applied shear stresses. (paper)

  17. Measurement of sediments thickness by ground penetrating radar; Denjihaho wo mochiita kotei taisekibutsu soatsu no sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Nozawa, E. [Tokyo Electric Power Co. Inc., Tokyo (Japan); Inagaki, M.

    1997-05-27

    An attempt was made to measure thickness of a layer of reservoir bottom sediments by utilizing the electromagnetic reflection method. Because water is a substance difficult for electromagnetic waves to permeate, considerations were given on to suppress attenuation to a minimum, and improve receiving sensitivity. The test used monocycle pulses with a central frequency of 200 MHz. In order to generate stabilized pulses with little unnecessary reflection, an antenna as large as it can be fitted into a rubber boat was employed. In order to acquire referential data, the test was carried out by using simultaneously a sound wave exploration device. The lake at which the test was carried out is a regulating reservoir with a size of about 250 m {times} 150 m, with its bottom made of concrete slab. This means that the lake consists of a three-layer structure comprising water, soil deposits, and concrete bottom from the water surface. According to an example of acquired electromagnetic exploration records, boundary reflection of water and sediments was observed clearly at water depths of 2 to 3 m as a shallow portion and 5 to 6 m as a deep portion. Reflection between the sediments and the bottom plate was also observed sufficiently distinctly. 3 refs., 8 figs.

  18. Quantification of model uncertainty in aerosol optical thickness retrieval from Ozone Monitoring Instrument (OMI measurements

    Directory of Open Access Journals (Sweden)

    A. Määttä

    2013-09-01

    Full Text Available We study uncertainty quantification in remote sensing of aerosols in the atmosphere with top of the atmosphere reflectance measurements from the nadir-viewing Ozone Monitoring Instrument (OMI. Focus is on the uncertainty in aerosol model selection of pre-calculated aerosol models and on the statistical modelling of the model inadequacies. The aim is to apply statistical methodologies that improve the uncertainty estimates of the aerosol optical thickness (AOT retrieval by propagating model selection and model error related uncertainties more realistically. We utilise Bayesian model selection and model averaging methods for the model selection problem and use Gaussian processes to model the smooth systematic discrepancies from the modelled to observed reflectance. The systematic model error is learned from an ensemble of operational retrievals. The operational OMI multi-wavelength aerosol retrieval algorithm OMAERO is used for cloud free, over land pixels of the OMI instrument with the additional Bayesian model selection and model discrepancy techniques. The method is demonstrated with four examples with different aerosol properties: weakly absorbing aerosols, forest fires over Greece and Russia, and Sahara dessert dust. The presented statistical methodology is general; it is not restricted to this particular satellite retrieval application.

  19. Structure model index does not measure rods and plates in trabecular bone

    Directory of Open Access Journals (Sweden)

    Phil L Salmon

    2015-10-01

    Full Text Available Structure model index (SMI is widely used to measure rods and plates in trabecular bone. It exploits the change in surface curvature that occurs as a structure varies from spherical (SMI = 4, to cylindrical (SMI = 3 to planar (SMI = 0. The most important assumption underlying SMI is that the entire bone surface is convex and that the curvature differential is positive at all points on the surface. The intricate connections within the trabecular continuum suggest that a high proportion of the surface could be concave, violating the assumption of convexity and producing regions of negative differential. We implemented SMI in the BoneJ plugin and included the ability to measure the amounts of surface that increased or decreased in area after surface mesh dilation, and the ability to visualize concave and convex regions. We measured SMI and its positive (SMI+ and negative (SMI- components, bone volume fraction (BV/TV, the fraction of the surface that is concave (CF, and mean ellipsoid factor (EF in trabecular bone using 38 X-ray microtomography (XMT images from a rat ovariectomy model of sex steroid rescue of bone loss, and 169 XMT images from a broad selection of 87 species' femora (mammals, birds, and a crocodile. We simulated bone resorption by eroding an image of elephant trabeculae and recording SMI and BV/TV at each erosion step. Up to 70%, and rarely less than 20%, of the trabecular surface is concave (CF 0.155 – 0.700. SMI is unavoidably influenced by aberrations from SMI-, which is strongly correlated with BV/TV and CF. The plate-to-rod transition in bone loss is an erroneous observation resulting from SMI's close and artefactual relationship with BV/TV. SMI cannot discern between the distinctive trabecular geometries typical of mammalian and avian bone, whereas EF clearly detects birds' more plate-like trabeculae. EF is free from confounding relationships with BV/TV and CF. SMI results reported in the literature should be treated with

  20. Validation of UV-visible aerosol optical thickness retrieved from spectroradiometer measurements

    Directory of Open Access Journals (Sweden)

    C. Brogniez

    2008-08-01

    Full Text Available Global and diffuse UV-visible solar irradiances are routinely measured since 2003 with a spectroradiometer operated by the Laboratoire d'Optique Atmosphérique (LOA located in Villeneuve d'Ascq, France. The analysis of the direct irradiance derived by cloudless conditions enables retrieving the aerosol optical thickness (AOT spectrum in the 330–450 nm range. The site hosts also sunphotometers from the AERONET/PHOTONS network performing routinely measurements of the AOT at several wavelengths. On one hand, comparisons between the spectroradiometer and the sunphotometer AOT at 440 nm as well as, when available, at 340 and 380 nm, show good agreement: in 2003–2005 at 440 nm the correlation coefficient, the slope and the intercept of the regression line are [0.97, 0.95, 0.025], and in 2006 at 440, 380 and 340 nm they are [0.97, 1.00, −0.013], [0.97, 0.98, −0.007], and [0.98, 0.98, −0.002] respectively. On the other hand, the AOT's spectral variations have been compared using the Angström exponents derived from AOT data at 340 and 440 nm for both instruments. The comparisons show that this parameter is difficult to retrieve accurately due to the small wavelength range and due to the weak AOT values. Thus, AOT derived at wavelengths outside the spectroradiometer range by means of an extrapolation using the Angström parameter would have large uncertainties, whereas spectroradiometer's spectral AOT could be used for direct validation of other AOT, such as those provided by satellite instruments.

  1. Development of Three-Ring Conductance Meter on Flexible Printed Circuit Board for Liquid Film Thickness Measurement

    International Nuclear Information System (INIS)

    Electrical methods which based on conductance of fluid film have been widely applied for many years. Recently, Damsohn developed a high speed liquid film sensor that has great time and spatial resolution by applying printed circuit board (PCB) and wire-mesh signal processing unit. However, the conductivity of the fluid can be affected by its temperature change and previous electrical methods have limitations of its applicability where a heat transfer is involved. In order to overcome this limitation, Kim proposed three-ring conductance method which can measure the liquid film thickness independent of the liquid temperature variation. In the present work, the three-ring conductance meter is improved by fabricating it on flexible printed circuit board (FPCB). Since the FPCB can be attached on a curved surface and can tolerate temperature up to 180 .deg. C, it is expected to be applied to more diverse experimental conditions of nuclear thermal-hydraulics. This paper introduces the three ring conductance meter on FPCB and a preliminary experimental result in order to show its feasibility for measuring liquid film thickness under temperature varying conditions. From this experimental research, the availability of three-ring conductance meter fabricated on FPCB for measuring film-thickness by using current output signal was proved. Besides, the necessity of customized electrode design depending on film-thickness was found. Also, it was confirmed that the manufactured three-ring conductance meter can measure the film-thickness regardless of temperature change

  2. On-line measurement of texture, thickness and plastic strain ratio on steel sheets using laser-ultrasound resonance spectroscopy

    International Nuclear Information System (INIS)

    Laser-ultrasonics is used as a non-contact technique to determine reliably and rapidly the crystallographic texture, the average plastic strain ratio, and the thickness of sheet metal on the production line. With laser-ultrasonics, a short laser pulse is used to generate a wideband pulse of ultrasound and a laser interferometer is used for detection. In this paper, a large number of echoes are collected and analyzed together to measure the natural resonance frequencies in the thickness of the sheet. From these frequencies, two texture coefficients, W400 and W420 are calculated, as well as a highly accurate measurement of the sheet thickness. Using these texture coefficients and well-known relationships, the average and planar variation of the plastic strain ratio, respectively 'r' and Δr, can be evaluated. Both parameters are indications of the formability of metals sheets. Measurements on 1 mm thick, ultra-low-carbon steel sheets at LTV Steel Company have shown the following measurement accuracies: 'r' to within ±0.04, Δr to within ±0.1, thickness to better than ± 1 μm. (author)

  3. In situ measurement using FBGs of process-induced strains during curing of thick glass/epoxy laminate plate

    DEFF Research Database (Denmark)

    Nielsen, Michael Wenani; Schmidt, Jacob Wittrup; Hattel, Jesper Henri;

    2012-01-01

    For large composite structures, such as wind turbine blades, thick laminates are required to withstand large in-service loads. During the manufacture of thick laminates, one of the challenges met is avoiding process-induced shape distortions and residual stresses. In this paper, embedded fibre...... Bragg grating sensors are used to monitor process-induced strains during vacuum infusion of a thick glass/epoxy laminate. The measured strains are compared with predictions from a cure hardening instantaneous linear elastic (CHILE) thermomechanical numerical model where different mechanical boundary...... conditions are employed. The accuracy of the CHILE model in predicting process-induced internal strains, in what is essentially a viscoelastic boundary value problem, is investigated. A parametric study is furthermore performed to reveal the effect of increasing the laminate thickness. The numerical model...

  4. Carotid intima-media thickness and distensibility measured by MRI at 3 T versus high-resolution ultrasound

    International Nuclear Information System (INIS)

    We evaluated an MRI protocol at 3 T for the assessment of morphological and functional properties of the common carotid artery (CCA) in 32 healthy volunteers and 20 patients with high-grade internal carotid artery stenosis. Wall thickness of the CCA was measured by using multislice 2D T2 dark blood fast spin echo sequences and compared with intima-media thickness (IMT) determined by ultrasound. Carotid distensibility coefficient (DC) quantified by blood pressure and CCA diameter change during the cardiac cycle was measured by ECG gated 3D T1 CINE MRI and M-mode ultrasound. Apart from generally higher values in MRI high agreement was found for wall thickness and compliance in volunteers and patients. Remaining differences between both methods may be attributed to slightly different methods for measuring IMT and DC. Our findings indicate that MRI at 3 T is a feasible and promising tool for the comprehensive assessment of normal carotid geometry and function. (orig.)

  5. Determination of Axial Length Requiring Adjustment of Measured Circumpapillary Retinal Nerve Fiber Layer Thickness for Ocular Magnification

    Science.gov (United States)

    Hirasawa, Kazunori; Shoji, Nobuyuki; Yoshii, Yukako; Haraguchi, Shota

    2014-01-01

    Purpose To determine the axial length requiring adjustment of measured circumpapillary retinal nerve fiber layer (cpRNFL) thickness to account for ocular magnification during spectral-domain optical coherence tomography (SD-OCT). Methods In this prospective study, 148 eyes of 148 healthy student volunteers were imaged by two examiners using three-dimensional SD-OCT. In 54 randomly selected eyes, total cpRNFL thickness was measured with and without adjustment for ocular magnification to establish intra-examiner and inter-examiner measurement error. The 148 eyes were then divided into three groups according to the error values: control group (difference in the corrected and uncorrected total cpRNFL thickness was within the measurement error range), thinner group (the corrected total cpRNFL thickness was less than the uncorrected one), and thicker group (the corrected total cpRNFL thickness was more than the uncorrected one). The cutoff values of axial length between the control and the other groups were calculated by receiver operating characteristic analysis. Results Measurement error ranged from 4.2 to 5.3 µm; the threshold value was defined as 5.3 µm. The cutoff values of axial length between the thinner and the control groups and between the control and the thicker groups were 23.60 (area under the curve [AUC] = 0.959) and 25.55 (AUC = 0.944) mm, respectively. Conclusions Axial lengths shorter than 23.60 mm and longer than 25.55 mm require adjustment of measured cpRNFL thickness to account for ocular magnification during SD-OCT. Clinical Trial Registration UMIN Clinical Trials Registry (http://www.umin.ac.jp/) under unique trial number UMIN000013248 (date of registration: 02/24/2014) PMID:25215521

  6. Relating wave attenuation to pancake ice thickness, using field measurements and model results

    Science.gov (United States)

    Doble, Martin J.; De Carolis, Giacomo; Meylan, Michael H.; Bidlot, Jean-Raymond; Wadhams, Peter

    2015-06-01

    Wave attenuation coefficients (α, m-1) were calculated from in situ data transmitted by custom wave buoys deployed into the advancing pancake ice region of the Weddell Sea. Data cover a 12 day period as the buoy array was first compressed and then dilated under the influence of a passing low-pressure system. Attenuation was found to vary over more than 2 orders of magnitude and to be far higher than that observed in broken-floe marginal ice zones. A clear linear relation between α and ice thickness was demonstrated, using ice thickness from a novel dynamic/thermodynamic model. A simple expression for α in terms of wave period and ice thickness was derived, for application in research and operational models. The variation of α was further investigated with a two-layer viscous model, and a linear relation was found between eddy viscosity in the sub-ice boundary layer and ice thickness.

  7. Macular thickness and macular volume measurements using spectral domain optical coherence tomography in normal Nepalese eyes

    OpenAIRE

    Pokharel A; Shrestha GS; Shrestha JB

    2016-01-01

    Amrit Pokharel,1 Gauri Shankar Shrestha,2 Jyoti Baba Shrestha2 1Department of Ophthalmology, Kathmandu Medical College Teaching Hospital, 2B P Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine, Kathmandu, Nepal Purpose: To record the normative values for macular thickness and macular volume in normal Nepalese eyes. Methods: In all, 126 eyes of 63 emmetropic subjects (mean age: 21.17±6.76 years; range: 10–37 years) were assessed for macular thickness and macular...

  8. Macular thickness and macular volume measurements using spectral domain optical coherence tomography in normal Nepalese eyes

    OpenAIRE

    Pokharel, Amrit

    2016-01-01

    Amrit Pokharel,1 Gauri Shankar Shrestha,2 Jyoti Baba Shrestha2 1Department of Ophthalmology, Kathmandu Medical College Teaching Hospital, 2B P Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine, Kathmandu, Nepal Purpose: To record the normative values for macular thickness and macular volume in normal Nepalese eyes. Methods: In all, 126 eyes of 63 emmetropic subjects (mean age: 21.17±6.76 years; range: 10–37 years) were assessed for macular thickness and...

  9. Measurement of bone mineral contents in Pakistan by dual photon absorptiometry

    International Nuclear Information System (INIS)

    Vertebral bone mineral content (BMC) was measured with dual photon absorptiometry in 144 normal males and 219 females (ages 11-85 years), 118 patients of hyperthyroidism, 7 of chronic renal failure and 5 each of postmenopausal osteoporosis and primary hyperparathyroidism. Generally males had higher BMC than females. Pattern of age related bone gain and diminution was same in both sexes but the rate of bone loss differed significantly, females having higher rate of bone loss. When compared to Western population lower BMC values in our normals were seen. However, rate of bone loss in our population was lower than that reported in the west. BMC values in patients suffering from hyperthyroidism and chronic renal failure were not significantly different that of age matched normals. The small numbers of cases of post menopausal osteoporosis and hyperpara- thyroidism, tough precluding any generalization, did show lower BMC values. Lower BMC values in our normal population could possibly be explained on racial ground. But in spite of less than ideal dietary status in our normal population in general, the lower rate of bone loss and a lower incidence of osteoporosis in hyperthyroid and chronic renal failure cases can raise the possibility of active vitamin D metabolism component, triggered by utraviolet radiation, having an overall beneficiary effect on the calcium cycle. This calls for a more comprehensive workup. (author)

  10. In vivo measurement of bone aluminum in population living in southern Ontario, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Davis, K.; Aslam,; Pejovic-Milic, A.; Chettle, D. R. [Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1 (Canada); Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3, Canada and Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1 (Canada); Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1 (Canada)

    2008-11-15

    The harmful biological effect of excessive aluminum (Al) load in humans has been well documented in the literature. Al stored in bone, for instance due to dialysis treatment or occupational exposure, can interfere with normal bone remodeling leading to osteodystrophy, osteoarthritis, or osteomalacia. On the other hand, the relationship between chronic Al exposure and the risk of Alzheimer's disease remains controversial. In this work, the feasibility of in vivo neutron activation analysis (IVNAA) for measuring Al levels in the human hand bone, using the thermal neutron capture reaction {sup 27}Al(n,{gamma}){sup 28}Al, is reported. This noninvasive diagnostic technique employs a high beam current Tandetron accelerator based neutron source, an irradiation/shielding cavity, a 4{pi} NaI(Tl) detector system, and a new set of hand bone phantoms. The photon spectra of the irradiated phantom closely resemble those collected from the hands of nonexposed healthy subjects. A protocol was developed using the newly developed hand phantoms, which resulted in a minimum detectable limit (MDL) of 0.29 mg Al in the human hand. Using the ratio of Al to Ca as an index of Al levels per unit bone mass, the MDL was determined as 19.5{+-}1.5 {mu}g Al/g Ca, which is within the range of the measured levels of 20-27 {mu}g Al/g Ca[ICRP, Report of the Task Group on Reference Man, Publication 23 (Pergamon, Oxford, 1975)] found in other in vivo and in vitro studies. Following the feasibility studies conducted with phantoms, the diagnostic technique was used to measure Al levels in the hand bones of 20 healthy human subjects. The mean hand bone Al concentration was determined as 27.1{+-}16.1 ({+-}1 SD) {mu}g Al/g Ca. The average standard error (1{sigma}) in the Al/Ca is 14.0 {mu}g Al/g Ca, which corresponds to an average relative error of 50% in the measured levels of Al/Ca. These results were achieved with a dose equivalent of 17.6 mSv to a hand and an effective dose of 14.4 {mu}Sv. This

  11. Thermal Conductivity Measurement of Submicron-Thick Aluminium Oxide Thin Films by a Transient Thermo-Reflectance Technique

    Institute of Scientific and Technical Information of China (English)

    BAI Su-Yuan; TANG Zhen-An; HUANG Zheng-Xing; YU Jun; WANG Jia-Qi

    2008-01-01

    Thermal conductivity of submicron-thick aluminium oxide thin films prepared by middle frequency magnetron sputtering is measured using a transient thermo-reflectance technique.A three-layer model based on transmission line theory and the gentic algorithm optimization method are employed to obtain the thermal conductivity of thin films and the interfacial thermal resistance.The results show that the average thermal conductivity of 3301000nm aluminium oxide thin films is 3.3Wm-1 K-1 at room temperature.No significant thickness dependence is found.The uncertainty of the measurement is less than 10%.

  12. Measurement of 2-dimensional local instantaneous liquid film thickness around simulated nuclear fuel rod by ultrasonic transmission technique

    International Nuclear Information System (INIS)

    An accurate knowledge of hydro-dynamic behavior of a liquid film flow on nuclear fuel rods is indispensable for analysis of the CHF under postulated loss-of-coolant-accidents in boiling water reactors. This work is concerned with a new development of ultrasonic transmission technique for film flow measurements. The technique adopted a rotating reflector, capable of measuring time-dependent spatial distribution of liquid film thickness around a simulated nuclear fuel rod. The scanning time is currently 4 ms for reconstruction of one image of the circumferential film thickness distribution. (orig.)

  13. Ultrasonic measurements of bubble shape and liquid film thickness of a Taylor bubble rising in a stagnant water column

    International Nuclear Information System (INIS)

    The present paper reports a preliminary study of direct measurement of the equilibrium thickness of the falling film around a Taylor bubble in a stagnant water column, using the pulse-echo ultrasonic technique. The experiments were conducted in an acrylic tube of 1.8 m long with inner diameter of 25.21 mm and wall thickness of 6.8 mm. A Taylor bubble was formed by the invertion of the pipe, sealed at the ends and partially filled with water to leave an air pocket of length L0. The rising Taylor bubble was detected by a transducer located 400 mm from the top of the pipe. Ten measurements were made for each of the four channels of the ultrasonic system, using the same settings of the system parameters, totaling 40 measured bubbles. A simplified Brown's model for the thickness around a Taylor bubble was used to calculate a reference value of the parameter being measured. We found that the values directly measured by the ultrasonic technique were in good agreement with the reference value calculated and thus conclude that the pulse-echo ultrasonic technique can be applied to directly measure the thickness of the falling film around the Taylor bubbles in acrylic tubes. The errors between the experimental and the reference values were in the order of 10%. (author)

  14. Cross-Sectional Elasticity Imaging of Arterial Wall by Comparing Measured Change in Thickness with Model Waveform

    Science.gov (United States)

    Tang, Jiang; Hasegawa, Hideyuki; Kanai, Hiroshi

    2005-06-01

    For the assessment of the elasticity of the arterial wall, we have developed the phased tracking method [H. Kanai et al.: IEEE Trans. Ultrason. Ferroelectr. Freq. Control 43 (1996) 791] for measuring the minute change in thickness due to heartbeats and the elasticity of the arterial wall with transcutaneous ultrasound. For various reasons, for example, an extremely small deformation of the wall, the minute change in wall thickness during one heartbeat is largely influenced by noise in these cases and the reliability of the elasticity distribution obtained from the maximum change in thickness deteriorates because the maximum value estimation is largely influenced by noise. To obtain a more reliable cross-sectional image of the elasticity of the arterial wall, in this paper, a matching method is proposed to evaluate the waveform of the measured change in wall thickness by comparing the measured waveform with a template waveform. The maximum deformation, which is used in the calculation of elasticity, was determined from the amplitude of the matched model waveform to reduce the influence of noise. The matched model waveform was obtained by minimizing the difference between the measured and template waveforms. Furthermore, a random error, which was obtained from the reproducibility among the heartbeats of the measured waveform, was considered useful for the evaluation of the reliability of the measured waveform.

  15. Structural health monitoring ultrasonic thickness measurement accuracy and reliability of various time-of-flight calculation methods

    Science.gov (United States)

    Eason, Thomas J.; Bond, Leonard J.; Lozev, Mark G.

    2016-02-01

    The accuracy, precision, and reliability of ultrasonic thickness structural health monitoring systems are discussed in-cluding the influence of systematic and environmental factors. To quantify some of these factors, a compression wave ultrasonic thickness structural health monitoring experiment is conducted on a flat calibration block at ambient temperature with forty four thin-film sol-gel transducers and various time-of-flight thickness calculation methods. As an initial calibration, the voltage response signals from each sensor are used to determine the common material velocity as well as the signal offset unique to each calculation method. Next, the measurement precision of the thickness error of each method is determined with a proposed weighted censored relative maximum likelihood analysis technique incorporating the propagation of asymmetric measurement uncertainty. The results are presented as upper and lower confidence limits analogous to the a90/95 terminology used in industry recognized Probability-of-Detection assessments. Future work is proposed to apply the statistical analysis technique to quantify measurement precision of various thickness calculation methods under different environmental conditions such as high temperature, rough back-wall surface, and system degradation with an intended application to monitor naphthenic acid corrosion in oil refineries.

  16. Microindentation for in vivo measurement of bone tissue mechanical properties in humans.

    Science.gov (United States)

    Diez-Perez, Adolfo; Güerri, Roberto; Nogues, Xavier; Cáceres, Enric; Peña, Maria Jesus; Mellibovsky, Leonardo; Randall, Connor; Bridges, Daniel; Weaver, James C; Proctor, Alexander; Brimer, Davis; Koester, Kurt J; Ritchie, Robert O; Hansma, Paul K

    2010-08-01

    Bone tissue mechanical properties are deemed a key component of bone strength, but their assessment requires invasive procedures. Here we validate a new instrument, a reference point indentation (RPI) instrument, for measuring these tissue properties in vivo. The RPI instrument performs bone microindentation testing (BMT) by inserting a probe assembly through the skin covering the tibia and, after displacing periosteum, applying 20 indentation cycles at 2 Hz each with a maximum force of 11 N. We assessed 27 women with osteoporosis-related fractures and 8 controls of comparable ages. Measured total indentation distance (46.0 +/- 14 versus 31.7 +/- 3.3 microm, p = .008) and indentation distance increase (18.1 +/- 5.6 versus 12.3 +/- 2.9 microm, p = .008) were significantly greater in fracture patients than in controls. Areas under the receiver operating characteristic (ROC) curve for the two measurements were 93.1% (95% confidence interval [CI] 83.1-100) and 90.3% (95% CI 73.2-100), respectively. Interobserver coefficient of variation ranged from 8.7% to 15.5%, and the procedure was well tolerated. In a separate study of cadaveric human bone samples (n = 5), crack growth toughness and indentation distance increase correlated (r = -0.9036, p = .018), and scanning electron microscope images of cracks induced by indentation and by experimental fractures were similar. We conclude that BMT, by inducing microscopic fractures, directly measures bone mechanical properties at the tissue level. The technique is feasible for use in clinics with good reproducibility. It discriminates precisely between patients with and without fragility fracture and may provide clinicians and researchers with a direct in vivo measurement of bone tissue resistance to fracture. PMID:20200991

  17. Study of osteoporosis through the measurement of bone mineral density and trace elements

    International Nuclear Information System (INIS)

    The main purpose of this study was to establish a relation, if any, between bone mineral density, BMD, of the healthy Turkish population of the ages between 15 and 50 with social and demographic information, family history of fractures, personal and inherited characteristic, smoking and alcohol habit, history of fertility, level of physical activity, food consumption especially trace elements and other variables. Most of these relations were discussed in the last RCM in San Diego, CA, October 7-10,1996. Since then we have concentrated our work on more BMD and trace element measurements in bone. To this end, bone mineral density measurements, trace element studies, neutron activation analysis, fluoride analysis and atomic absorption analysis were undertaken and resulting data were analysed

  18. Serial strain gauge measurement of bone healing in hoffmann® external fixation.

    Science.gov (United States)

    Nishimura, N

    1984-04-01

    In order to better assess callus strength for postoperative management of Hoffmann external fixation patients, the author attempted to estimate the amount of strain when bending or compressing the fracture site with a strain gauge glued to the middle of a connecting rod. Calculations in a computer architectural model of a plane beam structure show that the amount of strain on a connecting rod would decrease hyperbolically when the mechanical properties of the callus increased. Strength testing in a cadaveric crural bone confirms the importance of callus volume. The serial strain gauge measurement technique was applied to a series of 23 cases treated with Hoffmann external fixation, 20 of which achieved bone healing. On the basis of the bone healing curve obtained with the strain gauge measurements, the healing process is classified into five types. PMID:24822815

  19. In vivo bone lead measurements: a rapid monitoring method for cumulative lead exposure

    International Nuclear Information System (INIS)

    Lead concentrations (microgram/g wet weight) in human bone (tibia) were measured noninvasively in vivo employing an X-ray fluorescence technique. Forty-five workers who had been subjected to chronic industrial exposure were found to have a mean bone lead content of 52.9 micrograms/g wet weight (0 to 198 micrograms/g). In addition to bone lead content, blood lead, body burden of lead as assessed by urinary lead excretion after EDTA chelation, zinc protoporphyrin, and unstimulated urinary lead excretion were evaluated. The results suggest that the in vivo measurement of tibia lead content may serve as an acceptable indicator of body lead burden and provide a practical technique for lead screening purposes. The correlation coefficient between X-ray fluorescence findings and lead excretion following Ca-EDTA administration is 0.69; p less than 0.001

  20. Non-contact online thickness measurement system for metal films based on eddy current sensing with distance tracking technique

    Science.gov (United States)

    Li, Wei; Wang, Hongbo; Feng, Zhihua

    2016-04-01

    This paper proposes an online, non-contact metal film thickness measurement system based on eddy current sensing. The slope of the lift-off curve (LOC) is used for characterizing target thickness. Theoretical derivation was conducted to prove that the slope is independent of the lift-off variation. In practice, the measurement has some immunity to the lift-off, but not perfect. The slope of LOC is still affected at some extent by the lift-off. Hence, a height tracking system was also proposed, which could stabilize the distance between the sensor and the target and significantly reduce the lift-off effect. The height tracking system contains a specially designed probe, which could vibrate rapidly to obtain a fast measurement speed, and its height can be adjusted up and down continuously to stabilize the lift-off. The sensor coil in the thickness measurement system was also used as the height sensor in the height tracking system. Several experiments were conducted to test the system performances under static and dynamic conditions. This measurement system demonstrated significant advantages, such as simple and clear conversion between the slope of LOC and target thickness, high resolution and stability, and minimized effect of lift-off variation.

  1. Determination of the optical thickness and effective particle radius of clouds from reflected solar radiation measurements. I - Theory

    Science.gov (United States)

    Nakajima, Teruyuki; King, Michael D.

    1990-01-01

    A method is presented for determining the optical thickness and effective particle radius of stratiform cloud layers from reflected solar radiation measurements. A detailed study is presented which shows that the cloud optical thickness (tau c) and effective particle radius (r/e/) of water clouds can be determined solely from reflection function measurements at 0.75 micron and 2.16 microns, provided tau c is not less than 4 and r(e) is not less than 6 microns. For optically thin clouds, the retrieval becomes ambiguous, resulting in two possible solutions for the effective radius and optical thickness. Adding a third channel near 1.65 micron does not improve the situation noticeably, whereas the addition of a channel near 3.70 microns reduces the ambiguity in deriving the effective radius. The effective radius determined by the above procedure corresponds to the droplet radius at some optical depth within the cloud layer.

  2. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... of DXA Bone Densitometry? What is a Bone Density Scan (DXA)? Bone density scanning, also called dual-energy x-ray absorptiometry ( ... is today's established standard for measuring bone mineral density (BMD). An x-ray (radiograph) is a noninvasive ...

  3. Parametric electrical impedance tomography for measuring bone mineral density in the pelvis using a computational model.

    Science.gov (United States)

    Kimel-Naor, Shani; Abboud, Shimon; Arad, Marina

    2016-08-01

    Osteoporosis is defined as bone microstructure deterioration resulting a decrease of bone's strength. Measured bone mineral density (BMD) constitutes the main tool for Osteoporosis diagnosis, management, and defines patient's fracture risk. In the present study, parametric electrical impedance tomography (pEIT) method was examined for monitoring BMD, using a computerized simulation model and preliminary real measurements. A numerical solver was developed to simulate surface potentials measured over a 3D computerized pelvis model. Varying cortical and cancellous BMD were simulated by changing bone conductivity and permittivity. Up to 35% and 16% change was found in the real and imaginary modules of the calculated potential, respectively, while BMD changes from 100% (normal) to 60% (Osteoporosis). Negligible BMD relative error was obtained with SNR>60 [dB]. Position changes errors indicate that for long term monitoring, measurement should be taken at the same geometrical configuration with great accuracy. The numerical simulations were compared to actual measurements that were acquired from a healthy male subject using a five electrodes belt bioimpedance device. The results suggest that pEIT may provide an inexpensive easy to use tool for frequent monitoring BMD in small clinics during pharmacological treatment, as a complementary method to DEXA test. PMID:27185035

  4. Ultrasonic Derivative Measurements of Bone Strain During Exercise Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna Innovations, Inc., in collaboration with the SUNY Stony Brook, proposes to extend ultrasonic pulsed phase locked loop (PPLL) derivative measurements to the...

  5. Diffusion capacity and CT measures of emphysema and airway wall thickness – relation to arterial oxygen tension in COPD patients

    Science.gov (United States)

    Saure, Eirunn Waatevik; Bakke, Per Sigvald; Eagan, Tomas Mikal Lind; Aanerud, Marianne; Jensen, Robert Leroy; Grydeland, Thomas Blix; Johannessen, Ane; Nilsen, Roy Miodini; Thorsen, Einar; Hardie, Jon Andrew

    2016-01-01

    Background Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased arterial oxygen tension (PaO2), but there are limited data on associations between PaO2 and computed tomography (CT) derived measures of emphysema and airway wall thickness. Objective To examine whether CT measures of emphysema and airway wall thickness are associated with level of arterial oxygen tension beyond that provided by measurements of diffusion capacity and spirometry. Methods The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007–2008. Emphysema was assessed as percent of low-attenuation areasCOPD patients. Emphysema score measured by chest CT, is related to decreased PaO2, but cannot replace measurements of diffusion capacity in the clinical evaluation of hypoxaemia. PMID:27178139

  6. Application of non-destructive liner thickness measurement technique for manufacturing and inspection process of zirconium lined cladding tube

    International Nuclear Information System (INIS)

    Recently, in order to meet the difference of electric power demand owing to electric power situation, large scale load following operation has become necessary. Therefore, the development of the cladding tubes which withstand power variation has been carried out, as the result, zirconium-lined zircaloy 2 cladding tubes have been developed. In order to reduce the sensitivity to stress corrosion cracking, these zirconium-lined cladding tubes require uniform liner thickness over the whole surface and whole length. Kobe Steel Ltd. developed the nondestructive liner thickness measuring technique based on ultrasonic flaw detection technique and eddy current flaw detection technique. These equipments were applied to the manufacturing and inspection processes of the zirconium-lined cladding tubes, and have demonstrated superiority in the control and assurance of the liner thickness of products. Zirconium-lined cladding tubes, the development of the measuring technique for guaranteeing the uniform liner thickness and the liner thickness control in the manufacturing and inspection processes are described. (Kako, I.)

  7. Measurement of film thickness up to several hundreds of nanometers using optical waveguide lightmode spectroscopy.

    Science.gov (United States)

    Picart, Catherine; Gergely, Csilla; Arntz, Youri; Voegel, Jean-Claude; Schaaf, Pierre; Cuisinier, Frédéric J G; Senger, Bernard

    2004-10-15

    Up to now, most studies based on optical waveguide lightmode spectroscopy (OWLS) were dedicated to thin adlayers, assumed to be isotropic and homogeneous, for which data analysis was based on an approximation of the mode equations valid when the thickness is small with respect to the wavelength of the laser light. The aim of the present paper is to extend the use of OWLS to thicker deposited layers (up to approximately 400 nm). Both the simplified and extended models are compared in terms of optical parameters, i.e. the refractive index nA, the thickness dA, and the optical mass QA, for experimental data obtained with polyelectrolyte multilayer films. The deviation of these parameters can be quite large when derived using the simplified model instead of the extended model. This observation evidences that OWLS is well suited for the study of "thick" films if the appropriate model is applied to the data analysis. PMID:15494239

  8. Thickness Measurement of V2O5 Nanometric Thin Films Using a Portable XRF

    Directory of Open Access Journals (Sweden)

    Fabio Lopes

    2016-01-01

    Full Text Available Nanometric thin films have always been chiefly used for decoration; however they are now being widely used as the basis of high technology. Among the various physical qualities that characterize them, the thickness strongly influences their properties. Thus, a new procedure is hereby proposed and developed for determining the thickness of V2O5 nanometric thin films deposited on the glass surface using Portable X-Ray Fluorescence (PXRF equipment and the attenuation of the radiation intensity Kα of calcium present in the glass. It is shown through the present paper that the radiation intensity of calcium Kα rays is proportional to film thickness in nanometric films of vanadium deposited on the glass surface.

  9. Measurement of slice thickness and in-plane resolution on radiographic tomosynthesis system using modulation transfer function (MTF)

    Science.gov (United States)

    Li, Baojun; Saunders, Rowland; Uppaluri, Renuka

    2006-03-01

    A novel method to measure in-plane resolution (modulation transfer function, or MTF) and slice thickness (slice sensitivity profile, or SSP) of a digital radiographic tomosynthesis system is presented. With this method, one can measure these two important system IQ characteristics simultaneously without suffering from incontinuous sampling, aliasing, and partial volume effect as do the existing methods. The method is based on imaging a shallow-angled slice ramp phantom. The MTF is measured as the HWHM of the Fourier transformation of the first derivative of edge profiles. The HWHM corresponding to the sharpest of edge profile represents the in-plane resolution of the system, and the slice thickness of the system is determined from the HWHM vs. z-distance curve. The in-plane resolution result has been confirmed by the measurement from an animal skull specimen. The experiment results have shown that, for a typical 40-degree sweep, 61 projections, and using a Specialized Filtered Backprojection (SFBP) algorithm, the in-plane resolution of the measured system is close to 1 lp/mm (as measured by the HWHM of MTF), and effective slice thickness is 1.7 mm and 4.0 mm at HWHM and HW3TM, respectively. It is also observed that, while the in-plane resolution remains constant between planes at 7 cm and 30 cm above the detector plane, SSP has increased (i.e., slice thickness increased) 20% on average with the increase of the plane height. We demonstrate one of the applications of the method to optimize the sweep angle of a tomosynthesis system. The results show that, in a typical angular range from 20 to 60 degrees, the increase in sweep angle can intrinsically reduce slice thickness but less significantly impact in-plane resolution.

  10. Experimental determination of the thickness of aluminum cascade pipes in the presence of UF6 gas during enrichment measurements

    International Nuclear Information System (INIS)

    We present a method of determining the wall thickness of a pipe in a Gas Centrifuge Enrichment Plant (GCEP) when an empty pipe measurement is not feasible. Our method uses an X-ray tube for transmission measurements and a lanthanum bromide (LaBr3) scintillation detector on the opposite side of the pipe. Two filters, molybdenum (K-edge 20.0 keV) and palladium (K-edge 24.35 keV) are used to transform the bremsstrahlung spectra produced by the X-ray tube into more useful, sharply peaked, spectra. The maximum energies of the peaks are determined by the K-edges of the filters. The attenuation properties of the uranium hexafluoride (UF6) gas allow us to determine wall thickness by looking at the ratio of selected regions of interest (ROIs) of the Mo and Pd transmitted spectra. While the attenuation factor at these two transmission energies in the UF6 gas is nearly equal, attenuation in the aluminum pipe wall at these two energies differs by a factor of about 60. This difference allows measurement of attenuation in the pipe independent of attenuation in the UF6 gas. Feasibility studies were performed using analytical calculations, and filter thicknesses were optimized. In order to experimentally validate our attenuation measurement method, a UF6 source with variable enrichment and pipe thickness was built. We describe the experimental procedure used to verify our previous calculations and present recent results.

  11. Limits to the resolution of beam size measurement from fluorescent screens due to the thickness of the phosphor

    International Nuclear Information System (INIS)

    This paper discusses the use of fluorescent screens for the measurement of beam profiles on non-circulating particle beams. An expression for the intensity of the beam profile as a function of phosphor thickness is given. 3 refs., 8 figs

  12. Dual-role plasma absorption probe to study the effects of sheath thickness on the measurement of electron density

    International Nuclear Information System (INIS)

    A sensitive plasma absorption probe (PAP) is reported for measuring electron density in processing plasmas. The sheath formed around the probe tip is important for the resonance of surface waves. For determining the absolute electron density from the absorption frequency of the sensitive PAP, a proper value of sheath thickness relative to the Debye length is required to be assigned in the data processing. In this paper, a dual-role PAP has been proposed to study the effects of sheath thickness on the measurement of electron density. It is used as a Langmuir probe and a sensitive PAP simultaneously. Based on these two functions, the sheath thickness is calibrated before the measurement of electron density. The calibrated value is assigned in the data processing to replace the fitting coefficient used in the previous work. Therefore, the measurement error caused by an inaccurately assigned sheath thickness can be minimized effectively. Because of the bi-functional characteristic, the dual-role PAP is an independent diagnostic tool.

  13. Stabilization of measuring channel of reflective gamma thickness gage by light pulses from additional scintillator

    International Nuclear Information System (INIS)

    Possibility for using a sodium iodide scintillator as a reference signal source is considered. Experimental data on studying the performance of a gamma thickness gage with an additional scintillator are given. Results of experimental investigations of a thickness gage dummy proved practical expediency of the principle being considered. It is established, in particular, that the device is ready to operate without warm-up with a constant sensitivity, the deviation not exceeding 0.5%, in the ambient temperature range of 15-25 deg C

  14. Current socio-economic measures, and not those measured during infancy, affect bone mass in poor urban South african children.

    Science.gov (United States)

    Norris, Shane A; Sheppard, Zoë A; Griffiths, Paula L; Cameron, Noël; Pettifor, John M

    2008-09-01

    Understanding the impact of socio-economic status (SES) on physical development in children is important, especially in developing countries where considerable inequalities persist. This is the first study to examine the association between SES on bone development at the whole body, femoral neck, and lumbar spine in black children living in Soweto and Johannesburg, South Africa. Linear regression models were used to study associations between SES during infancy and current SES, anthropometric, and DXA-derived bone mass in 9/10-yr-old children (n = 309). Findings suggest that current SES measures, rather than SES during infancy, are stronger predictors of current whole body bone area (BA) and whole body BMC after adjusting for body size, pubertal development, physical activity, habitual dietary calcium intake, and body composition. SES had no significant effect on either hip or spine bone mass. Caregiver's marital/cohabiting status (indicator of social support) and whether there was a television in the home (indicator of greater income) at age 9/10 yr were the most important socio-economic determinants of whole body BA and BMC. SES has a significant independent effect on whole body BMC through its impact on BA. This suggests that poverty alleviation policies in South Africa could have a positive effect on bone health. PMID:18442310

  15. Study of osteoporosis through the measurement of bone mineral density and trace elements

    International Nuclear Information System (INIS)

    The main purpose of this study was to establish a relation, if any, between bone mineral density (BMD) of the healthy Turkish population of the ages between 15 and 50 with social and demographic information, family history of fractures, personal and inherited characteristic, smoking and alcohol habit, history of fertility, level of physical activity, food consumption especially trace elements and other variables. Most of these relations were discussed in the last two Research Coordinated Meetings, in San Diego, CA, October 1996 and Sao Paulo, Brazil, August 1998. Since then we have concentrated our work on more BMD and trace element measurements in bone

  16. Thickness measurement of Sn-Ag hot dip coatings on Large Hadron Collider Superconducting strands by coulometry

    CERN Document Server

    Scheuerlein, C; Arnau-Izquierdo, G; Oberli, L R; Taborelli, M; 10.1149/1.1715094

    2004-01-01

    Amperostatic coulometry was applied for the thickness measurement of Sn-Ag hot dip coatings, which comprise an extended Sn-Cu interdiffusion layer. Complementary measurements, notably weight loss, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, X-ray fluorescence (XRF), and dynamic secondary ion mass spectroscopy were performed in order to obtain a better interpretation of the coulometry results. Based on the experimental results presented in this article, the three potential changes observed during coulometry measurements are ascribed to (i) the entire dissolution of pure Sn, (ii) the formation of a CuCl salt layer, and (iii) the surface passivation. The measurement of the pure Sn mass is well reproducible despite strong coating thickness variations detected by XRF. Several experimental problems, in particular, a coating undercutting, hamper the determination of the Sn mass in the intermetallic Sn-Cu layer. (19 refs).

  17. Simplified two media method: A modified approach for measuring linear attenuation coefficient of odd shaped archaeological samples of unknown thickness

    International Nuclear Information System (INIS)

    Linear attenuation coefficients of regular as well as irregular shaped archaeological samples of FaLG (flyash-lime-gypsum) of unknown thickness have been measured employing 'simplified two media' method. Seven different liquid materials plus air have been used as media to measure attenuation coefficient of these samples. Obtained results have been compared with those for regular shaped samples. Experimental values have also been compared with theoretical values calculated from FFAST and XCOM. A good agreement has been observed between experimental and theoretical values. Present measurements employing 'simplified two media' method have been reported for the first time for checking its validation and reliability. - Highlights: → Linear attenuation coefficients were measured. → Irregular shaped FaLG archaeological samples were of unknown thickness. → Use of FaLG bricks as an eco-friendly construction material. → Simplified two media method was used and experimentally tested.

  18. In vivo sweat film layer thickness measured with Fourier-domain optical coherence tomography (FD-OCT)

    Science.gov (United States)

    Jonathan, Enock

    2008-06-01

    While human sweat secretion is accepted as a mechanism by which the body cools off, excessive sweating (hyperhidrosis) is now appreciated as a medical condition and the primary site for diagnosis is the palm of the hand. We propose sweat film layer thickness as a potential clinical diagnostic parameter when screening for excessive sweating. In this preliminary study we demonstrate the usefulness of Fourier-domain optical coherence tomography (FD-OCT) for measurement of sweat film thickness in vivo with micron-scale resolution on the hand of a human volunteer. FD-OCT has a superior image acquisition time and identification of active sweat glands, ducts and pores is also possible.

  19. Measurement of the speed of sound in trabecular bone by using a time reversal acoustics focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Il [Kangwon National University, Chuncheon (Korea, Republic of); Choi, Bok-Kyoung [Maritime Security Research Center, KIOST, Ansan (Korea, Republic of)

    2014-10-15

    A new method for measuring the speed of sound (SOS) in trabecular bone by using a time reversal acoustics (TRA) focusing system was proposed and validated with measurements obtained by using the conventional pulse-transmission technique. The SOS measured in 14 bovine femoral trabecular bone samples by using the two methods was highly correlated each other, although the SOS measured by using the TRA focusing system was slightly lower by an average of 2.2 m/s. The SOS measured by using the two methods showed high correlation coefficients of r = 0.92 with the apparent bone density, consistent with the behavior in human trabecular bone in vitro. These results prove the efficacy of the new method based on the principle of TRA to measure the SOS in trabecular bone.

  20. Articular Cartilage Thickness Measured with US is Not as Easy as It Appears

    DEFF Research Database (Denmark)

    Torp-Pedersen, Søren; Bartels, E. M.; Wilhjelm, Jens E.;

    2011-01-01

    Background: Theoretically, the high spatial resolution of US makes it well suited to monitor the decrease in articular cartilage thickness in osteoarthritis. A requirement is, however, that the borders of the cartilage are correctly identified and that the cartilage ismeasured under orthogonal in...