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Sample records for ground glass opacities

  1. Surgery for Pulmonary Multiple Ground Glass Opacities

    Directory of Open Access Journals (Sweden)

    Qun WANG

    2016-06-01

    Full Text Available The incidence of pulmonary ground glass opacity (GGO has been increasing in recent years, with a great number of patients having multiple GGOs. Unfortunately, the management of multiple GGOs is still controversial. Pulmonary GGO is a radiological term, consisting of different pathological types. Some of the GGOs are early-staged lung cancer. GGO is an indolent nodule, only a small proportion of GGOs change during observation, which does not influence the efficacy of surgery. . The timing of surgery for multiple GGOs mainly depends on the predominant nodule and surgery is recommended if the solid component of the predominant nodule >5 mm. Either lobectomy or sub-lobectomy is feasible. GGOs other than the predominant nodule can be left unresected. Multiple GGOs with high risk factors need mediastinal lymph node dissection or sampling.

  2. Ground-glass opacity in lung metastasis from adenocarcinoma of the stomach: a case report

    International Nuclear Information System (INIS)

    Jung, Mi Ran; Kim, Jeong Kon; Lee, Jin Seong; Song, Koun Sik; Lim, Tae Hwan

    2000-01-01

    Ground-glass opacity is a frequent but nonspecific finding seen on high-resolution CT scans of lung parenchyma. Histologically, this appearance is observed when thickening of the alveolar wall and septal interstitium is minimal or the alveolar lumen is partially filled with fluid, macrophage, neutrophils, or amorphous material. It has been shown that ground-glass opacity may be caused not only by an active inflammatory process but also by fibrotic processes. When a focal area of ground-glass opacity persists or increases in size, the possibility of neoplasm-bronchioloalveolar carcinoma or adenoma, or lymphoma, for example, should be considered. Diffuse nonsegmental ground-glass opacity in both lung fields was incidentally found on follow up abdominal CT in a stomach cancer patient and signet-ring cell-type metastatic lung cancer was confirmed by transbronchial lung biopsy. We report a case of diffuse ground-glass opacity seen in metastatic lung cancer from adenocarcinoma of the stomach. (author)

  3. Ground-glass opacity at high resolution CT: an approach for differential diagnosis

    International Nuclear Information System (INIS)

    Spina, Juan C.; Rogondino, Jose; Vidales, Valeria; Rolnik, Maria C.; Montanari, Mariano; Salazar, Santiago N.

    2004-01-01

    Purpose: To evaluate the Ground-Glass Opacity in high resolution computed tomography (HRCT) with its underlying abnormality and anatomic distribution and its correlation with different etiologies. Methods: A 38 patients series, (32 men, 16 women, mean age 54,6 years, range 20-28) was retrospectively analyzed. They were evaluated with high resolution computed tomography, 2 mm thick sections and 10 mm of interval. Contrast intravenous iodinated contrast (no-ionic) was injected in 11 patients. The final diagnosis was made with sputum analysis, bronchioalveolar lavage, trans bronchial biopsy and open lung biopsy. Results: The differential diagnosis of ground glass opacity is based on analyzing their anatomic resolution and the underlying pathology in the lung parenchyma. Centrilobular distribution indicated early air-spaces pathology produced in our series by 21 infections, 4 pulmonary hemorrhages, 1 hypersensitivity pneumonitis and 1 descamative interstitial pneumonitis. Panlobular distribution, alveolar proteinosis (1 case) sarcoidosis (1 case) drug toxicity 1 case and one case of pneumocystis carinii. Peripherical distribution typical of early idiopathic fibrosis (1). Bronchiolitis obliterans with organizing pneumonia (1). Structural alterations of the lung parenchyma with bronchiectasias was seen in 16 cases, cystic lesions in 3 cases, sub pleural linear opacities 4 cases, peribronchovascular interstitial thickening or nodularity and emphysema in 10 cases. Conclusion: HRCT is useful to evaluate ground glass opacities pattern with the anatomic distribution and the underlying structural pathology. These findings under some clinical circumstances can suggest a specific diagnosis in most cases, indicating a potentially treatable disease. (author)

  4. Ground-glass opacity in diffuse lung diseases: high-resolution computed tomography-pathology correlation

    International Nuclear Information System (INIS)

    Santos, Maria Lucia de Oliveira; Vianna, Alberto Domingues; Marchiori, Edson; Souza Junior, Arthur Soares; Moraes, Heleno Pinto de

    2003-01-01

    Ground-glass opacity is a finding frequently seen in high-resolution computed tomography examinations of the chest and is characterized by hazy increased attenuation of lung, however without blurring of bronchial and vascular margins. Due to its un specificity, association with other radiological, clinical and pathological findings must be considered for an accurate diagnostic interpretation. In this paper were reviewed 62 computed tomography examinations of patients with diffuse pulmonary diseases of 14 different etiologies in which ground-glass opacity was the only or the most remarkable finding, and correlated this findings with pathology abnormalities seen on specimens obtained from biopsies or necropsies. In pneumocystosis, ground-glass opacities correlated histologically with alveolar occupation by a foaming material containing parasites, in bronchiole alveolar cell carcinoma with thickening of the alveolar septa and occupation of the lumen by mucus and tumoral cells, in paracoccidioidomycosis with thickening of the alveolar septa, areas of fibrosis and alveolar bronchopneumonia exudate, in sarcoidosis with fibrosis or clustering of granulomas and in idiopathic pulmonary fibrosis with alveolar septa thickening due to fibrosis. Alveolar occupation by blood was found in cases of leptospirosis, idiopathic hemo siderosis, metastatic kidney tumor and invasive aspergillosis whereas oily vacuole were seen in lipoid pneumonia, proteinaceous and lipo proteinaceous material in silico proteinosis and pulmonary alveolar proteinosis, and edematous fluid in cardiac failure. (author)

  5. The relative frequencies of causes of widespread ground-glass opacity: A retrospective cohort

    International Nuclear Information System (INIS)

    Hewitt, Michael G.; Miller, Wallace T.; Reilly, Thomas J.; Simpson, Scott

    2014-01-01

    Highlights: • The most common cause of widespread ground-glass opacities is hydrostatic pulmonary edema. • Associated findings such as air-trapping and centrilobular nodules are highly specific for hypersensitivity pneumonitis. • The clinical setting (outpatient versus inpatient) will alter the order of the differential diagnosis. - Abstract: Purpose: The purpose of our study was to determine the relative frequencies of causes of widespread ground-glass opacity (GGO) in an unselected, consecutive patient population and to identify any associated imaging findings that can narrow or reorganize the differential. Materials and methods: The study was approved by the center's IRB and is HIPPA compliant. Cases with widespread GGO in the radiology report were identified by searching the Radiology Information System. Medical records and CT scan examinations were reviewed for the causes of widespread GGO. Associations between a less dominant imaging finding and a particular diagnosis were analyzed with the chi square test. Our study group consisted of 234 examinations with 124 women and 110 men and a mean age of 53.7 years. Results: A cause was established in 204 (87.2%) cases. Hydrostatic pulmonary edema was most common with 131 cases (56%). Interstitial lung diseases (ILD) were the next most common, most often hypersensitivity pneumonitis (HP) (n = 12, 5%) and connective tissue disease related ILD (n = 7, 3%). Infection accounted for 5% (12 cases). A few miscellaneous diseases accounted for 5 cases (2.1%). The combination of septal thickening and pleural effusions had a specificity of 0.91 for hydrostatic pulmonary edema (P < .001) while centrilobular nodules and air trapping had a specificity of 1.0 for HP. In 24 (10.2%) patients, increased opacification from expiration was incorrectly interpreted as representing widespread ground glass opacity. The relative frequency of disease dramatically changed according to the setting. In the inpatient setting, diffuse

  6. The relative frequencies of causes of widespread ground-glass opacity: A retrospective cohort

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    Hewitt, Michael G., E-mail: Mike_hewitt@me.com; Miller, Wallace T., E-mail: Wallace.miller@uphs.upenn.edu; Reilly, Thomas J., E-mail: thomasjreilly@comcast.net; Simpson, Scott, E-mail: Simpson80@gmail.com

    2014-10-15

    Highlights: • The most common cause of widespread ground-glass opacities is hydrostatic pulmonary edema. • Associated findings such as air-trapping and centrilobular nodules are highly specific for hypersensitivity pneumonitis. • The clinical setting (outpatient versus inpatient) will alter the order of the differential diagnosis. - Abstract: Purpose: The purpose of our study was to determine the relative frequencies of causes of widespread ground-glass opacity (GGO) in an unselected, consecutive patient population and to identify any associated imaging findings that can narrow or reorganize the differential. Materials and methods: The study was approved by the center's IRB and is HIPPA compliant. Cases with widespread GGO in the radiology report were identified by searching the Radiology Information System. Medical records and CT scan examinations were reviewed for the causes of widespread GGO. Associations between a less dominant imaging finding and a particular diagnosis were analyzed with the chi square test. Our study group consisted of 234 examinations with 124 women and 110 men and a mean age of 53.7 years. Results: A cause was established in 204 (87.2%) cases. Hydrostatic pulmonary edema was most common with 131 cases (56%). Interstitial lung diseases (ILD) were the next most common, most often hypersensitivity pneumonitis (HP) (n = 12, 5%) and connective tissue disease related ILD (n = 7, 3%). Infection accounted for 5% (12 cases). A few miscellaneous diseases accounted for 5 cases (2.1%). The combination of septal thickening and pleural effusions had a specificity of 0.91 for hydrostatic pulmonary edema (P < .001) while centrilobular nodules and air trapping had a specificity of 1.0 for HP. In 24 (10.2%) patients, increased opacification from expiration was incorrectly interpreted as representing widespread ground glass opacity. The relative frequency of disease dramatically changed according to the setting. In the inpatient setting, diffuse

  7. Ground-Glass Opacity Lung Nodules in the Era of Lung Cancer CT Screening

    DEFF Research Database (Denmark)

    Pedersen, Jesper Holst; Saghir, Zaigham; Wille, Mathilde Marie Winkler

    2016-01-01

    The advent of computed tomography screening for lung cancer will increase the incidence of ground-glass opacity (GGO) nodules detected and referred for diagnostic evaluation and management. GGO nodules remain a diagnostic challenge; therefore, a more systematic approach is necessary to ensure...... that will yield improvements in both diagnosis and treatment. The standard-of-care surgical treatment of early lung cancer is still minimally invasive lobectomy with systematic lymph node dissection. However, recent research has shown that some GGO lesions may be treated with sublobar resections; these findings......, the National Comprehensive Cancer Network, and the British Thoracic Society. In addition, we discuss the management and follow-up of GGO nodules in the light of experience from screening trials. Minimally invasive tissue biopsies and the marking of GGO nodules for surgery are new and rapidly developing fields...

  8. Ground-glass opacity: High-resolution computed tomography and 64-multi-slice computed tomography findings comparison

    International Nuclear Information System (INIS)

    Sergiacomi, Gianluigi; Ciccio, Carmelo; Boi, Luca; Velari, Luca; Crusco, Sonia; Orlacchio, Antonio; Simonetti, Giovanni

    2010-01-01

    Objective: Comparative evaluation of ground-glass opacity using conventional high-resolution computed tomography technique and volumetric computed tomography by 64-row multi-slice scanner, verifying advantage of volumetric acquisition and post-processing technique allowed by 64-row CT scanner. Methods: Thirty-four patients, in which was assessed ground-glass opacity pattern by previous high-resolution computed tomography during a clinical-radiological follow-up for their lung disease, were studied by means of 64-row multi-slice computed tomography. Comparative evaluation of image quality was done by both CT modalities. Results: It was reported good inter-observer agreement (k value 0.78-0.90) in detection of ground-glass opacity with high-resolution computed tomography technique and volumetric Computed Tomography acquisition with moderate increasing of intra-observer agreement (k value 0.46) using volumetric computed tomography than high-resolution computed tomography. Conclusions: In our experience, volumetric computed tomography with 64-row scanner shows good accuracy in detection of ground-glass opacity, providing a better spatial and temporal resolution and advanced post-processing technique than high-resolution computed tomography.

  9. Multidetector CT features of pulmonary focal ground-glass opacity: differences between benign and malignant

    Science.gov (United States)

    Fan, L; Liu, S-Y; Li, Q-C; Yu, H; Xiao, X-S

    2012-01-01

    Objective To evaluate different features between benign and malignant pulmonary focal ground-glass opacity (fGGO) on multidetector CT (MDCT). Methods 82 pathologically or clinically confirmed fGGOs were retrospectively analysed with regard to demographic data, lesion size and location, attenuation value and MDCT features including shape, margin, interface, internal characteristics and adjacent structure. Differences between benign and malignant fGGOs were analysed using a χ2 test, Fisher's exact test or Mann–Whitney U-test. Morphological characteristics were analysed by binary logistic regression analysis to estimate the likelihood of malignancy. Results There were 21 benign and 61 malignant lesions. No statistical differences were found between benign and malignant fGGOs in terms of demographic data, size, location and attenuation value. The frequency of lobulation (p=0.000), spiculation (p=0.008), spine-like process (p=0.004), well-defined but coarse interface (p=0.000), bronchus cut-off (p=0.003), other air-containing space (p=0.000), pleural indentation (p=0.000) and vascular convergence (p=0.006) was significantly higher in malignant fGGOs than that in benign fGGOs. Binary logistic regression analysis showed that lobulation, interface and pleural indentation were important indicators for malignant diagnosis of fGGO, with the corresponding odds ratios of 8.122, 3.139 and 9.076, respectively. In addition, a well-defined but coarse interface was the most important indicator of malignancy among all interface types. With all three important indicators considered, the diagnostic sensitivity, specificity and accuracy were 93.4%, 66.7% and 86.6%, respectively. Conclusion An fGGO with lobulation, a well-defined but coarse interface and pleural indentation gives a greater than average likelihood of being malignant. PMID:22128130

  10. Percutaneous Radiofrequency Ablation of Lung Cancer Presenting as Ground-Glass Opacity

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    Iguchi, Toshihiro, E-mail: iguchi@ba2.so-net.ne.jp; Hiraki, Takao, E-mail: takaoh@tc4.so-net.ne.jp; Gobara, Hideo, E-mail: gobara@cc.okayama-u.ac.jp; Fujiwara, Hiroyasu, E-mail: hirofujiwar@gmail.com; Matsui, Yusuke, E-mail: wckyh140@yahoo.co.jp [Okayama University Medical School, Department of Radiology (Japan); Soh, Junichi, E-mail: soh-j@cc.okayama-u.ac.jp; Toyooka, Shinichi, E-mail: shintoyooka@gmail.com [Okayama University Medical School, Department of General Thoracic Surgery (Japan); Kiura, Katsuyuki, E-mail: kkiura@md.okayama-u.ac.jp [Okayama University Medical School, Department of Respiratory Medicine (Japan); Kanazawa, Susumu, E-mail: susumu@cc.okayama-u.ac.jp [Okayama University Medical School, Department of Radiology (Japan)

    2015-04-15

    PurposeWe retrospectively evaluated the outcomes of lung cancer patients presenting with ground-glass opacity (GGO) who received radiofrequency ablation (RFA).MethodsSixteen patients (5 men and 11 women; mean age, 72.6 years) with 17 lung cancer lesions showing GGO (mean long axis diameter, 1.6 cm) underwent a total of 20 percutaneous computed tomography (CT) fluoroscopy-guided RFA sessions, including three repeated sessions for local progression. Lung cancer with GGO was defined as a histologically confirmed malignant pulmonary lesion with a GGO component accounting for >50 % of the lesion on high-resolution CT. Procedure outcomes were evaluated.ResultsThere were no major complications. Pneumothorax occurred in 15 of 20 treatment sessions: 14 were asymptomatic, and 1 required chest tube placement but resolved satisfactorily within 48 h. Minor pulmonary hemorrhage occurred in two and mild pneumonitis in one. The median tumor follow-up period was 61.5 (range 6.1–96.6) months. The effectiveness rates of the primary and secondary techniques were 100 and 100 % at 1 year, 93.3 and 100 % at 2 years, and 78.3 and 92.3 % at 3 years, respectively. The median patient follow-up period was 65.6 (range 6.1–96.6) months. One patient died owing to recurrent other cancer 11.7 months after RFA, whereas the other 15 remained alive. Overall survival and disease-specific survival rates were 93.3 and 100 % at 1 year and 93.3 and 100 % at 5 years, respectively.ConclusionsRFA for lung cancer with GGO was safe and effective, and resulted in promising survival rates.

  11. Deep neural network convolution (NNC) for three-class classification of diffuse lung disease opacities in high-resolution CT (HRCT): consolidation, ground-glass opacity (GGO), and normal opacity

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    Hashimoto, Noriaki; Suzuki, Kenji; Liu, Junchi; Hirano, Yasushi; MacMahon, Heber; Kido, Shoji

    2018-02-01

    Consolidation and ground-glass opacity (GGO) are two major types of opacities associated with diffuse lung diseases. Accurate detection and classification of such opacities are crucially important in the diagnosis of lung diseases, but the process is subjective, and suffers from interobserver variability. Our study purpose was to develop a deep neural network convolution (NNC) system for distinguishing among consolidation, GGO, and normal lung tissue in high-resolution CT (HRCT). We developed ensemble of two deep NNC models, each of which was composed of neural network regression (NNR) with an input layer, a convolution layer, a fully-connected hidden layer, and a fully-connected output layer followed by a thresholding layer. The output layer of each NNC provided a map for the likelihood of being each corresponding lung opacity of interest. The two NNC models in the ensemble were connected in a class-selection layer. We trained our NNC ensemble with pairs of input 2D axial slices and "teaching" probability maps for the corresponding lung opacity, which were obtained by combining three radiologists' annotations. We randomly selected 10 and 40 slices from HRCT scans of 172 patients for each class as a training and test set, respectively. Our NNC ensemble achieved an area under the receiver-operating-characteristic (ROC) curve (AUC) of 0.981 and 0.958 in distinction of consolidation and GGO, respectively, from normal opacity, yielding a classification accuracy of 93.3% among 3 classes. Thus, our deep-NNC-based system for classifying diffuse lung diseases achieved high accuracies for classification of consolidation, GGO, and normal opacity.

  12. Advances in intelligent diagnosis methods for pulmonary ground-glass opacity nodules.

    Science.gov (United States)

    Yang, Jing; Wang, Hailin; Geng, Chen; Dai, Yakang; Ji, Jiansong

    2018-02-07

    Pulmonary nodule is one of the important lesions of lung cancer, mainly divided into two categories of solid nodules and ground glass nodules. The improvement of diagnosis of lung cancer has significant clinical significance, which could be realized by machine learning techniques. At present, there have been a lot of researches focusing on solid nodules. But the research on ground glass nodules started late, and lacked research results. This paper summarizes the research progress of the method of intelligent diagnosis for pulmonary nodules since 2014. It is described in details from four aspects: nodular signs, data analysis methods, prediction models and system evaluation. This paper aims to provide the research material for researchers of the clinical diagnosis and intelligent analysis of lung cancer, and further improve the precision of pulmonary ground glass nodule diagnosis.

  13. Clinical, pathological, and radiological characteristics of solitary ground-glass opacity lung nodules on high-resolution computed tomography

    Directory of Open Access Journals (Sweden)

    Qiu ZX

    2016-09-01

    Full Text Available Zhi-Xin Qiu,1 Yue Cheng,1 Dan Liu,1 Wei-Ya Wang,2 Xia Wu,2 Wei-Lu Wu,2 Wei-Min Li1,2 1Department of Respiratory Medicine, 2Department of Pathology, West China Hospital, Sichuan University, Chengdu, People’s Republic of China Background: Lung nodules are being detected at an increasing rate year by year with high-resolution computed tomography (HRCT being widely used. Ground-glass opacity nodule is one of the special types of pulmonary nodules that is confirmed to be closely associated with early stage of lung cancer. Very little is known about solitary ground-glass opacity nodules (SGGNs. In this study, we analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT.Methods: A total of 95 resected SGGNs were evaluated with HRCT scan. The clinical, pathological, and radiological characteristics of these cases were analyzed.Results: Eighty-one adenocarcinoma and 14 benign nodules were observed. The nodules included 12 (15% adenocarcinoma in situ (AIS, 14 (17% minimally invasive adenocarcinoma (MIA, and 55 (68% invasive adenocarcinoma (IA. No patients with recurrence till date have been identified. The positive expression rates of anaplastic lymphoma kinase and ROS-1 (proto-oncogene tyrosine-protein kinase ROS were only 2.5% and 8.6%, respectively. The specificity and accuracy of HRCT of invasive lung adenocarcinoma were 85.2% and 87.4%. The standard uptake values of only two patients determined by 18F-FDG positron emission tomography/computed tomography (PET/CT were above 2.5. The size, density, shape, and pleural tag of nodules were significant factors that differentiated IA from AIS and MIA. Moreover, the size, shape, margin, pleural tag, vascular cluster, bubble-like sign, and air bronchogram of nodules were significant determinants for mixed ground-glass opacity nodules (all P<0.05.Conclusion: We analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT and found that the size, density

  14. Clinical Features of Ground Glass Opacity-Dominant Lung Cancer Exceeding 3.0 cm in the Whole Tumor Size.

    Science.gov (United States)

    Suzuki, Shigeki; Sakurai, Hiroyuki; Yotsukura, Masaya; Masai, Kyohei; Asakura, Keisuke; Nakagawa, Kazuo; Motoi, Noriko; Watanabe, Shun-Ichi

    2018-05-01

    Ground glass opacity (GGO)-dominant lung adenocarcinoma sized 3.0 cm or less in the whole tumor size is widely known to have an excellent prognosis and is regarded as early lung cancer. However, the characteristics and prognosis of lung cancer showing GGO exceeding 3.0 cm remains unclear. From 2002 through 2012, we reviewed 3,735 lung cancers that underwent complete resection at our institution. We identified 160 lung cancers (4.3%) showing GGO exceeding 3.0 cm on thin-section computed tomography and divided them into three types by the consolidation/tumor ratio (CTR) using cutoff values of 0.25 and 0.5. We compared the characteristics and prognosis among these types. Type A (CTR, 0 to ≤0.25), type B (CTR, >0.25 to ≤0.5), and type C (CTR, >0.5 to 3.0 cm can be considered to be in a group of patients with nodal-negative disease and an excellent prognosis. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Imaging-guided thoracoscopic resection of a ground-glass opacity lesion in a hybrid operating room equipped with a robotic C-arm CT system.

    Science.gov (United States)

    Hsieh, Chen-Ping; Hsieh, Ming-Ju; Fang, Hsin-Yueh; Chao, Yin-Kai

    2017-05-01

    The intraoperative identification of small pulmonary nodules through video-assisted thoracoscopic surgery remains challenging. Although preoperative CT-guided nodule localization is commonly used to detect tumors during video-assisted thoracoscopic surgery (VATS), this approach carries inherent risks. We report the case of a patient with stage I lung cancer presenting as an area of ground-glass opacity (GGO) in the right upper pulmonary lobe. He successfully underwent a single-stage, CT-guided localization and removal of the pulmonary nodule within a hybrid operating room (OR) equipped with a robotic C-arm.

  16. Comparison of chest radiography, chest digital tomosynthesis and low dose MDCT to detect small ground-glass opacity nodules: an anthropomorphic chest phantom study

    International Nuclear Information System (INIS)

    Doo, Kyung Won; Kang, Eun-Young; Yong, Hwan Seok; Ham, Soo-Youn; Lee, Ki Yeol; Choo, Ji Yung

    2014-01-01

    The purpose of this study was to evaluate the diagnostic performance of chest radiography (CXR), chest digital tomosynthesis (DT) and low dose multidetector computed tomography (LDCT) for the detection of small pulmonary ground-glass opacity (GGO) nodules, using an anthropomorphic chest phantom. Artificial pulmonary nodules were placed in a phantom and a total of 40 samples of different nodule settings underwent CXR, DT and LDCT. The images were randomly read by three experienced chest radiologists. Free-response receiver-operating characteristics (FROC) were used. The figures of merit for the FROC curves averaged for the three observers were 0.41, 0.37 and 0.76 for CXR, DT and LDCT, respectively. FROC analyses revealed significantly better performance of LDCT over CXR or DT for the detection of GGO nodules (P < 0.05). The difference in detectability between CXR and DT was not statistically significant (P = 0.73). The diagnostic performance of DT for the detection of pulmonary small GGO nodules was not significantly different from that of CXR, but LDCT performed significantly better than both CXR and DT. DT is not a suitable alternative to CT for small GGO nodule detection, and LDCT remains the method of choice for this purpose. (orig.)

  17. Comparison of chest radiography, chest digital tomosynthesis and low dose MDCT to detect small ground-glass opacity nodules: an anthropomorphic chest phantom study

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    Doo, Kyung Won; Kang, Eun-Young; Yong, Hwan Seok [Korea University Guro Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Ham, Soo-Youn [Korea University Anam Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Lee, Ki Yeol; Choo, Ji Yung [Korea University Ansan Hospital, Korea University College of Medicine, Department of Radiology, Ansan (Korea, Republic of)

    2014-12-15

    The purpose of this study was to evaluate the diagnostic performance of chest radiography (CXR), chest digital tomosynthesis (DT) and low dose multidetector computed tomography (LDCT) for the detection of small pulmonary ground-glass opacity (GGO) nodules, using an anthropomorphic chest phantom. Artificial pulmonary nodules were placed in a phantom and a total of 40 samples of different nodule settings underwent CXR, DT and LDCT. The images were randomly read by three experienced chest radiologists. Free-response receiver-operating characteristics (FROC) were used. The figures of merit for the FROC curves averaged for the three observers were 0.41, 0.37 and 0.76 for CXR, DT and LDCT, respectively. FROC analyses revealed significantly better performance of LDCT over CXR or DT for the detection of GGO nodules (P < 0.05). The difference in detectability between CXR and DT was not statistically significant (P = 0.73). The diagnostic performance of DT for the detection of pulmonary small GGO nodules was not significantly different from that of CXR, but LDCT performed significantly better than both CXR and DT. DT is not a suitable alternative to CT for small GGO nodule detection, and LDCT remains the method of choice for this purpose. (orig.)

  18. Loss of cellular viability in areas of ground-glass opacity on computed tomography images immediately after pulmonary radiofrequency ablation in rabbits

    International Nuclear Information System (INIS)

    Kuroki, Masaomi; Nakada, Hiroshi; Yamashita, Atsushi; Sawaguchi, Akira; Uchino, Noriko; Sato, Shinya; Asada, Yujiro; Tamura, Shozo; Asanuma, Taketoshi

    2012-01-01

    The purpose of this study was to determine cellular viability of lung parenchyma and neoplastic cells in areas of ground-glass opacity (GGO) on computed tomography (CT) images immediately after pulmonary radiofrequency ablation (RFA) in rabbits. A LeVeen RFA electrode was placed percutaneously into rabbit lungs with or without metastatic VX2 tumors. Five minutes later, seven isolated lungs were imaged by use of a multi-detector row CT scanner, and the images were compared with histological features. The cellular viability of the lung tissues was assessed by nicotinamide adenine dinucleotide hydrogen (NADH) staining in eight normal lungs and in three lungs with multiple metastatic tumors. All lung lesions appeared as bilayered structures with a central, dense, attenuated area and an outer area of GGO on CT images, and as three-layered structures on macroscopic and microscopic images 5 min after RFA. The GGO areas approximately corresponded to the outer two layers in macroscopic images that were exudative and congestive on microscopic images. Staining for NADH was significantly reduced in the GGO and densely attenuated areas with or without tumor tissue staining compared with the non-ablated area. Our results suggest that an area of GGO that appears on CT immediately after RFA can be effectively treated by RFA. (author)

  19. Comparison of multi-slice CT findings between malignant focal pulmonary ground-glass opacity nodules and solid nodules of 3 cm or less

    International Nuclear Information System (INIS)

    Fan Li; Yu Hong; Liu Shiyuan; Li Qingchu; Jiang Tao; Xiao Xiangsheng

    2010-01-01

    Objective: To compare the MSCT findings of malignant focal pulmonary ground-glass opacity nodules (fGGO) and solid nodules of 3 cm or less, and try to find specific signs in fGGO. Methods: Clinical data (sex ratio, age), size of lesion and MSCT findings (shape, margin, interface, internal characteristics, adjacent structure) of 105 cases pathologically confirmed to have solid lung cancers and 48 cases with fGGO less than 3 cm were retrospectively analyzed. Differences were analyzed by using the Fisher exact test or Mann-Whitney U test. Results: The male and female ratio of solid lung cancer(60:45) were higher than that of fGGO (18:30, X 2 value 5.09, P 2 values were 11.48, 4.07, 29.70 and 22.38 respectively, P 2 values 1.00, 2.20, 0.00, 0.15, 4.43, 1.50, 0.00, P>0.05). Conclusions: Malignant fGGO and solid lung cancer manifest mostly similar MSCT features. The frequency of irregular shape, vacuole sign and air bronchograms was higher in fGGO than in solid lung cancer to some degree, but speculation is more infrequent in fGGO, which may be attribute to thepathological type and basis of tumor. (authors)

  20. CT characteristics and pathological implications of early stage (T1N0M0) lung adenocarcinoma with pure ground-glass opacity

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    Jin, Xin; Zhao, Shao-hong; Wu, Jian; Wu, Chong-chong; Chang, Rui-ping; Ju, Hai-yue [Chinese PLA General Hospital, Department of Radiology, Beijing (China); Gao, Jie; Wang, Dian-jun [Chinese PLA General Hospital, Department of Pathology, Beijing (China)

    2015-09-15

    To analyze the CT characteristics and pathological classification of early lung adenocarcinoma (T1N0M0) with pure ground-glass opacity (pGGO). Ninety-four lesions with pGGO on CT in 88 patients with T1N0M0 lung adenocarcinoma were selected from January 2010 to December 2012. All lesions were confirmed by pathology. CT appearances were analyzed including lesion location, size, density, uniformity, shape, margin, tumour-lung interface, internal and surrounding malignant signs. Lesion size and density were compared using analysis of variance, lesion size also assessed using ROC curves. Gender of patients, lesion location and CT appearances were compared using χ2-test. There were no significant differences in gender, lesion location and density with histological invasiveness (P > 0.05). The ROC curve showed that the possibility of invasive lesion was 88.73 % when diameter of lesion was more than 10.5 mm. There was a significant difference between lesion uniformity and histological invasiveness (P = 0.01). There were significant differences in margin, tumour-lung interface, air bronchogram with histological invasiveness (P = 0.02,P = 0.00,P = 0.048). The correlation index of lesion size and uniformity was r = 0.45 (P = 0.00). The lesion size and uniformity, tumour-lung interface and the air bronchogram can help predict invasive extent of early stage lung adenocarcinoma with pGGO. (orig.)

  1. Ground-glass opacity in diffuse lung diseases: high-resolution computed tomography-pathology correlation; Opacidades em vidro fosco nas doencas pulmonares difusas: correlacao da tomografia computadorizada de alta resolucao com a anatomopatologia

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    Santos, Maria Lucia de Oliveira; Vianna, Alberto Domingues; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Disciplina de Radiologia; Moraes, Heleno Pinto de [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Patologia]. E-mail: edmarchiori@zipmail.com.br

    2003-12-01

    Ground-glass opacity is a finding frequently seen in high-resolution computed tomography examinations of the chest and is characterized by hazy increased attenuation of lung, however without blurring of bronchial and vascular margins. Due to its un specificity, association with other radiological, clinical and pathological findings must be considered for an accurate diagnostic interpretation. In this paper were reviewed 62 computed tomography examinations of patients with diffuse pulmonary diseases of 14 different etiologies in which ground-glass opacity was the only or the most remarkable finding, and correlated this findings with pathology abnormalities seen on specimens obtained from biopsies or necropsies. In pneumocystosis, ground-glass opacities correlated histologically with alveolar occupation by a foaming material containing parasites, in bronchiole alveolar cell carcinoma with thickening of the alveolar septa and occupation of the lumen by mucus and tumoral cells, in paracoccidioidomycosis with thickening of the alveolar septa, areas of fibrosis and alveolar bronchopneumonia exudate, in sarcoidosis with fibrosis or clustering of granulomas and in idiopathic pulmonary fibrosis with alveolar septa thickening due to fibrosis. Alveolar occupation by blood was found in cases of leptospirosis, idiopathic hemo siderosis, metastatic kidney tumor and invasive aspergillosis whereas oily vacuole were seen in lipoid pneumonia, proteinaceous and lipo proteinaceous material in silico proteinosis and pulmonary alveolar proteinosis, and edematous fluid in cardiac failure. (author)

  2. Predictive value of mutant p53 expression index obtained from nonenhanced computed tomography measurements for assessing invasiveness of ground-glass opacity nodules

    Directory of Open Access Journals (Sweden)

    Wang W

    2016-03-01

    Full Text Available Wei Wang,1 Jian Li,2 Ransheng Liu,1 Aixu Zhang,1 Zhiyong Yuan1 1Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, People’s Republic of China; 2Department of Radiology, Tianjin Hospital, Tianjin, People’s Republic of China Purpose: To predict p53 expression index (p53-EI based on measurements from computed tomography (CT for preoperatively assessing pathologies of nodular ground-glass opacities (nGGOs. Methods: Information of 176 cases with nGGOs on high-resolution CT that were pathologically confirmed adenocarcinoma was collected. Diameters, total volumes (TVs, maximum (MAX, average (AVG, and standard deviation (STD of CT attenuations within nGGOs were measured. p53-EI was evaluated through immunohistochemistry with Image-Pro Plus 6.0. A multiple linear stepwise regression model was established to calculate p53-EI prediction from CT measurements. Receiver-operating characteristic curve analysis was performed to compare the diagnostic performance of variables in differentiating preinvasive adenocarcinoma (PIA, minimally invasive adenocarcinoma (MIA, and invasive adenocarcinoma (IAC. Results: Diameters, TVs, MAX, AVG, and STD showed significant differences among PIAs, MIAs, and IACs (all P-values <0.001, with only MAX being incapable to differentiate MIAs from IACs (P=0.106. The mean p53-EIs of PIAs, MIAs, and IACs were 3.4±2.0, 7.2±1.9, and 9.8±2.7, with significant intergroup differences (all P-values <0.001. An equation was established by multiple linear regression as: p53-EI prediction =0.001* TVs +0.012* AVG +0.022* STD +9.345, through which p53-EI predictions were calculated to be 4.4%±1.0%, 6.8%±1.3%, and 8.5%±1.4% for PIAs, MIAs, and IACs (Kruskal–Wallis test P<0.001; Tamhane’s T2 test: PIA vs MIA P<0.001, MIA vs IAC P<0.001, respectively. Although not significant, p53-EI prediction

  3. Investigation of optimal display size for detecting ground-glass opacity on high resolution computed tomography using a new digital contrast-detail phantom

    International Nuclear Information System (INIS)

    Yamaguchi, Michihiro; Fujita, Hideki; Bessho, Yuichi; Inoue, Tatsuro; Asai, Yoshiyuki; Murase, Kenya

    2011-01-01

    The purpose of this study was to clarify the relationship between display sizes of high resolution computed tomography (HRCT) images for detecting ground-glass opacity (GGO) and observer performance using a digital contrast-detail (d-CD) phantom. A structure of the d-CD phantom was determined on the basis of the actual images of GGOs and background noises of 22 patients who were diagnosed as GGO by chest HRCT. The d-CD phantom has a 512 × 512 matrix in size and has total of 100 holes: the diameter of these holes increases stepwise from 2 to 20 pixels with 2 pixels interval in a vertical direction and the CT value varies stepwise from 2 to 200 HU in a horizontal direction. The observer performance study was carried out for three different display sizes (30 cm × 30 cm as an enlarged size, 13 cm × 13 cm as an original size, and 7 cm × 7 cm as a reduced size) using a 2-megapixels LCD monitor, and it was analyzed using Friedman and Wilcoxon statistical tests. As a result, the observer performance for the original display and the reduced display sizes was superior to that for the enlarged size (P = 0.006 and 0.037 for the original display and the reduced display sizes, respectively), whereas there was no significant difference between the original display and reduced display sizes (P = 0.77). The d-CD phantom enables a short-term evaluation of observer performance and is useful in analyzing relationship between display size and observer performance.

  4. Effect of reconstruction algorithm on image quality and identification of ground-glass opacities and partly solid nodules on low-dose thin-section CT: Experimental study using chest phantom

    International Nuclear Information System (INIS)

    Koyama, Hisanobu; Ohno, Yoshiharu; Kono, Atsushi A.; Kusaka, Akiko; Konishi, Minoru; Yoshii, Masaru; Sugimura, Kazuro

    2010-01-01

    Purpose: The purpose of this study was to assess the influence of reconstruction algorithm on identification and image quality of ground-glass opacities (GGOs) and partly solid nodules on low-dose thin-section CT. Materials and methods: A chest CT phantom including simulated GGOs and partly solid nodules was scanned with five different tube currents and reconstructed by using standard (A) and newly developed (B) high-resolution reconstruction algorithms, followed by visually assessment of identification and image quality of GGOs and partly solid nodules by two chest radiologists. Inter-observer agreement, ROC analysis and ANOVA were performed to compare identification and image quality of each data set with those of the standard reference. The standard reference used 120 mA s in conjunction with reconstruction algorithm A. Results: Kappa values (κ) of overall identification and image qualities were substantial or almost perfect (0.60 < κ). Assessment of identification showed that area under the curve of 25 mA reconstructed with reconstruction algorithm A was significantly lower than that of standard reference (p < 0.05), while assessment of image quality indicated that 50 mA s reconstructed with reconstruction algorithm A and 25 mA s reconstructed with both reconstruction algorithms were significantly lower than standard reference (p < 0.05). Conclusion: Reconstruction algorithm may be an important factor for identification and image quality of ground-glass opacities and partly solid nodules on low-dose CT examination.

  5. Evaluation of the extent of ground-glass opacity on high-resolution CT in patients with interstitial pneumonia associated with systemic sclerosis: Comparison between quantitative and qualitative analysis

    International Nuclear Information System (INIS)

    Yabuuchi, H.; Matsuo, Y.; Tsukamoto, H.; Horiuchi, T.; Sunami, S.; Kamitani, T.; Jinnouchi, M.; Nagao, M.; Akashi, K.; Honda, H.

    2014-01-01

    Aim: To verify whether quantitative analysis of the extent of ground-glass opacity (GGO) on high-resolution computed tomography (HRCT) could show a stronger correlation with the therapeutic response of interstitial pneumonia (IP) associated with systemic sclerosis (SSc) compared with qualitative analysis. Materials and methods: Seventeen patients with IP associated with SSc received autologous peripheral blood stem cell transplantation (auto-PBSCT) and were followed up using HRCT and pulmonary function tests. Two thoracic radiologists assessed the extent of GGO on HRCT using a workstation. Therapeutic effect was assessed using the change of vital capacity (VC) and diffusing capacity of the lung for carbon monoxide (DLco) before and 12 months after PBSCT. Interobserver agreement was assessed using Spearman's rank correlation coefficient and the Bland–Altman method. Correlation with the therapeutic response between quantitative and qualitative analysis was assessed with Pearson's correlation coefficients. Results: Spearman's rank correlation coefficient showed good agreement, but Bland–Altman plots showed that proportional error could be suspected. Quantitative analysis showed stronger correlation than the qualitative analysis based on the relationships between the change in extent of GGO and VC, and change in extent of GGO and DLco. Conclusion: Quantitative analysis of the change in extent of GGO showed stronger correlation with the therapeutic response of IP with SSc after auto-PBSCT than with the qualitative analysis. - Highlights: • Quantitative analysis of GGO in IP showed strong correlation with therapeutic effect. • Qualitative analysis might be limited by interobserver variance. • Other parameters including reticular opacities remain in a future investigation

  6. Thin-section computed tomography–histopathologic comparisons of pulmonary focal interstitial fibrosis, atypical adenomatous hyperplasia, adenocarcinoma in situ, and minimally invasive adenocarcinoma with pure ground-glass opacity

    Energy Technology Data Exchange (ETDEWEB)

    Si, Ming-Jue, E-mail: smjsh@hotmail.com [Department of Radiology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, No. 280, Mohe Road, Shanghai 201999 (China); Tao, Xiao-Feng, E-mail: taoxiaofeng1963@hotmail.com [Department of Radiology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, No. 280, Mohe Road, Shanghai 201999 (China); Du, Guang-Ye, E-mail: 715376158@qq.com [Department of Pathology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, No. 280, Mohe Road, Shanghai 201999 (China); Cai, Ling-Ling, E-mail: caill_00@163.com [Department of Radiology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, No. 280, Mohe Road, Shanghai 201999 (China); Han, Hong-Xiu, E-mail: hanhongxiu@hotmail.com [Department of Pathology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, No. 280, Mohe Road, Shanghai 201999 (China); Liang, Xi-Zi, E-mail: liangxizish@hotmail.com [Department of Pathology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, No. 280, Mohe Road, Shanghai 201999 (China); Zhao, Jiang-Min, E-mail: zhaojiangmin1962@hotmail.com [Department of Radiology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, No. 280, Mohe Road, Shanghai 201999 (China)

    2016-10-15

    Objective: To retrospectively compare focal interstitial fibrosis (FIF), atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), and minimally invasive adenocarcinoma (MIA) with pure ground-glass opacity (GGO) using thin-section computed tomography (CT). Materials and methods: Sixty pathologically confirmed cases were reviewed including 7 cases of FIF, 17 of AAH, 23of AIS, and 13 of MIA. All nodules kept pure ground glass appearances before surgical resection and their last time of thin-section CT imaging data before operation were collected. Differences of patient demographics and CT features were compared among these four types of lesions. Results: FIF occurred more frequently in males and smokers while the others occurred more frequently in female nonsmokers. Nodule size was significant larger in MIA (P < 0.001, cut-off value = 7.5 mm). Nodule shape (P = 0.045), margin characteristics (P < 0.001), the presence of pleural indentation (P = 0.032), and vascular ingress (P < 0.001) were significant factors that differentiated the 4 groups. A concave margin was only demonstrated in a high proportion of FIF at 85.7% (P = 0.002). There were no significant differences (all P > 0.05) in age, malignant history, attenuation value, location, and presence of bubble-like lucency. Conclusion: A nodule size >7.5 mm increases the possibility of MIA. A concave margin could be useful for differentiation of FIF from the other malignant or pre-malignant GGO nodules. The presence of spiculation or pleural indentation may preclude the diagnosis of AAH.

  7. TU-H-CAMPUS-JeP2-03: Machine-Learning-Based Delineation Framework of GTV Regions of Solid and Ground Glass Opacity Lung Tumors at Datasets of Planning CT and PET/CT Images

    Energy Technology Data Exchange (ETDEWEB)

    Ikushima, K; Arimura, H; Jin, Z; Yabuuchi, H; Sasaki, T; Honda, H; Sasaki, M [Kyushu University, Fukuoka, Fukuoka (Japan); Kuwazuru, J [Saiseikai Fukuoka General Hospital, Fukuoka, Fukuoka (Japan); Shioyama, Y [Saga Heavy Ion Medical Accelerator in Tosu, Tosu, Saga (Japan)

    2016-06-15

    Purpose: In radiation treatment planning, delineation of gross tumor volume (GTV) is very important, because the GTVs affect the accuracies of radiation therapy procedure. To assist radiation oncologists in the delineation of GTV regions while treatment planning for lung cancer, we have proposed a machine-learning-based delineation framework of GTV regions of solid and ground glass opacity (GGO) lung tumors following by optimum contour selection (OCS) method. Methods: Our basic idea was to feed voxel-based image features around GTV contours determined by radiation oncologists into a machine learning classifier in the training step, after which the classifier produced the degree of GTV for each voxel in the testing step. Ten data sets of planning CT and PET/CT images were selected for this study. The support vector machine (SVM), which learned voxel-based features which include voxel value and magnitudes of image gradient vector that obtained from each voxel in the planning CT and PET/CT images, extracted initial GTV regions. The final GTV regions were determined using the OCS method that was able to select a global optimum object contour based on multiple active delineations with a level set method around the GTV. To evaluate the results of proposed framework for ten cases (solid:6, GGO:4), we used the three-dimensional Dice similarity coefficient (DSC), which denoted the degree of region similarity between the GTVs delineated by radiation oncologists and the proposed framework. Results: The proposed method achieved an average three-dimensional DSC of 0.81 for ten lung cancer patients, while a standardized uptake value-based method segmented GTV regions with the DSC of 0.43. The average DSCs for solid and GGO were 0.84 and 0.76, respectively, obtained by the proposed framework. Conclusion: The proposed framework with the support vector machine may be useful for assisting radiation oncologists in delineating solid and GGO lung tumors.

  8. Opacity

    CERN Document Server

    Huebner, Walter F

    2014-01-01

    The interaction of radiation with matter is a fundamental process in the universe; in particular, the absorption and scattering of radiation by matter (the opacity) govern the formation, evolution, and structure of stars and planets.  But opacity is also important in many terrestrial applications in which radiation is the dominant means of energy transfer, such as controlled nuclear-fusion, laser ablation, atmospheric entry and reentry, and the "greenhouse" effect.  This book covers all aspects of opacity and equations of state for plasmas, gases, vapors, and dust and emphasizes the continuous transformation of phases and molecular compositions with changing density and temperature under conditions of local thermodynamic equilibrium (LTE) while preserving the basic abundances of the chemical elements in a mixture.

  9. Opacity

    International Nuclear Information System (INIS)

    Reina N, Ramon

    2003-01-01

    Their objective is to specify and to clarify many of the terms that are frequently employees and routinely in the description of the discoveries that appear in the x-rays of the thorax and in its complementary studies as it is the case of the computerized tomography; for the previous reason, it is considered important to include the term of opacity this it should be the first term to use when it is an abnormal discovery in the x-ray that causes an increase in the lung density of any etiology

  10. Quantitative CT analysis of pulmonary ground-glass opacity nodules for distinguishing invasive adenocarcinoma from non-invasive or minimally invasive adenocarcinoma: the added value of using iodine mapping

    International Nuclear Information System (INIS)

    Son, Ji Ye; Lee, Ho Yun; Kim, Jae-Hun; Lee, Kyung Soo; Han, Joungho; Jeong, Ji Yun; Kwon, O.J.; Shim, Young Mog

    2016-01-01

    To determine whether quantitative analysis of iodine-enhanced images generated from dual-energy CT (DECT) have added value in distinguishing invasive adenocarcinoma from non-invasive or minimally invasive adenocarcinoma (MIA) showing ground-glass nodule (GGN). Thirty-four patients with 39 GGNs were enrolled in this prospective study and underwent DECT followed by complete tumour resection. Various quantitative imaging parameters were assessed, including virtual non-contrast (VNC) imaging and iodine-enhanced imaging. Of all 39 GGNs, four were adenocarcinoma in situ (AIS) (10 %), nine were MIA (23 %), and 26 were invasive adenocarcinoma (67 %). When assessing only VNC imaging, multivariate analysis revealed that mass, uniformity, and size-zone variability were independent predictors of invasive adenocarcinoma (odds ratio [OR] = 19.92, P = 0.02; OR = 0.70, P = 0.01; OR = 16.16, P = 0.04, respectively). After assessing iodine-enhanced imaging with VNC imaging, both mass on the VNC imaging and uniformity on the iodine-enhanced imaging were independent predictors of invasive adenocarcinoma (OR = 5.51, P = 0.04 and OR = 0.67, P < 0.01). The power of diagnosing invasive adenocarcinoma was improved after adding the iodine-enhanced imaging parameters versus VNC imaging alone, from 0.888 to 0.959, respectively (P = 0.029). Quantitative analysis using iodine-enhanced imaging metrics versus VNC imaging metrics alone generated from DECT have added value in distinguishing invasive adenocarcinoma from AIS or MIA. (orig.)

  11. Quantitative CT analysis of pulmonary ground-glass opacity nodules for distinguishing invasive adenocarcinoma from non-invasive or minimally invasive adenocarcinoma: the added value of using iodine mapping

    Energy Technology Data Exchange (ETDEWEB)

    Son, Ji Ye; Lee, Ho Yun; Kim, Jae-Hun; Lee, Kyung Soo [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, 81 Irwon-Ro, Gangnam-gu, Seoul (Korea, Republic of); Han, Joungho [Sungkyunkwan University School of Medicine, Department of Pathology, Samsung Medical Center, Seoul (Korea, Republic of); Jeong, Ji Yun [Sungkyunkwan University School of Medicine, Department of Pathology, Samsung Medical Center, Seoul (Korea, Republic of); Kyungpook National University Medical Center, Kyungpook National University School of Medicine, Department of Pathology, Daegu (Korea, Republic of); Kwon, O.J. [Sungkyunkwan University School of Medicine, Division of Respiratory and Critical Medicine of the Department of Internal Medicine, Samsung Medical Center, Seoul (Korea, Republic of); Shim, Young Mog [Sungkyunkwan University School of Medicine, Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, 81 Irwon-Ro, Gangnam-gu, Seoul (Korea, Republic of)

    2016-01-15

    To determine whether quantitative analysis of iodine-enhanced images generated from dual-energy CT (DECT) have added value in distinguishing invasive adenocarcinoma from non-invasive or minimally invasive adenocarcinoma (MIA) showing ground-glass nodule (GGN). Thirty-four patients with 39 GGNs were enrolled in this prospective study and underwent DECT followed by complete tumour resection. Various quantitative imaging parameters were assessed, including virtual non-contrast (VNC) imaging and iodine-enhanced imaging. Of all 39 GGNs, four were adenocarcinoma in situ (AIS) (10 %), nine were MIA (23 %), and 26 were invasive adenocarcinoma (67 %). When assessing only VNC imaging, multivariate analysis revealed that mass, uniformity, and size-zone variability were independent predictors of invasive adenocarcinoma (odds ratio [OR] = 19.92, P = 0.02; OR = 0.70, P = 0.01; OR = 16.16, P = 0.04, respectively). After assessing iodine-enhanced imaging with VNC imaging, both mass on the VNC imaging and uniformity on the iodine-enhanced imaging were independent predictors of invasive adenocarcinoma (OR = 5.51, P = 0.04 and OR = 0.67, P < 0.01). The power of diagnosing invasive adenocarcinoma was improved after adding the iodine-enhanced imaging parameters versus VNC imaging alone, from 0.888 to 0.959, respectively (P = 0.029). Quantitative analysis using iodine-enhanced imaging metrics versus VNC imaging metrics alone generated from DECT have added value in distinguishing invasive adenocarcinoma from AIS or MIA. (orig.)

  12. The diagnostic value of grand glass opacity on HRCT of the lung

    International Nuclear Information System (INIS)

    He Wen; Ma Daqing; Feng Jie; He Qing; Hu Zhihai

    2001-01-01

    Objective: To determine the value of ground glass opacity (GGO) as a diagnostic sign of HRCT by means of analyzing a group of 34 cases retrospectively. Methods: Thirty-four cases of lung diseases, in which GGO were found on HRCT, were included in this study. The diagnosis was proven by lung biopsy in 7 cases, by endoscopy and micro-phytology in 7 cases and clinically in 20 cases. The distribution, extent and associated findings of GGO were studied in correlation with the final diagnosis retrospectively. Results: In these 34 cases, 20 cases were interstitial diseases, in which GGO distributed peripherally with an ill-defined margin. In 8 cases of parenchymal diseases, the lesion had a lobar or segmental distribution with a relatively well-defined margin. In 6 cases with chronic obstructive airway diseases, the GGO located centrally or peripherally, and most of them had a mosaic pattern with dilatation of vessels in the center of GGO. Conclusion: GGO is a nonspecific finding on chest HRCT, and may be seen in various diseases including interstitial and parenchymal diseases, or in diseases causing increased capillary blood volume. To analyze the morphological characteristics of GGO and associated CT findings correlating with clinical history can narrow the range of diagnostic possibilities and lead to a correct diagnosis

  13. Opacidades em vidro fosco nas doenças pulmonares difusas: correlação da tomografia computadorizada de alta resolução com a anatomopatologia Ground-glass opacity in diffuse lung diseases: high-resolution computed tomography-pathology correlation

    Directory of Open Access Journals (Sweden)

    Maria Lúcia de Oliveira Santos

    2003-12-01

    Full Text Available Opacidade em vidro fosco é achado freqüentemente visto na tomografia computadorizada de alta resolução do tórax e se traduz pelo aumento do coeficiente de atenuação dos pulmões, mas sem apagar as marcas broncovasculares. Por sua inespecificidade, a associação com outros achados radiológicos, clínicos e anatomopatológicos deve ser considerada para uma interpretação diagnóstica mais correta. Neste trabalho foram analisados 62 exames tomográficos de pacientes com doenças pulmonares difusas, de 14 etiologias diferentes, em que opacidades em vidro fosco foram o achado único ou predominante, e feita correlação anatomopatológica por meio de biópsias ou necropsias. Na pneumocistose as opacidades em vidro fosco corresponderam, histologicamente, à ocupação alveolar por material espumoso contendo parasitos; no carcinoma bronquíolo-alveolar, a espessamento dos septos alveolares e ocupação de sua luz por muco e células tumorais; na paracoccidioidomicose, a espessamento dos septos alveolares, áreas de fibrose e alvéolos contendo exsudato broncopneumônico; na sarcoidose, a fibrose ou a acúmulo de granulomas; na fibrose pulmonar idiopática, a espessamento dos septos alveolares por fibrose; na bronquiolite obliterante com pneumonia em organização, a pneumonia intersticial com áreas de organização intra-alveolar. A ocupação alveolar por sangue foi observada nos casos de leptospirose, hemossiderose idiopática, metástases de tumor renal e na aspergilose invasiva; por vacúolos de gordura na pneumonia lipídica; por material protéico e lipoprotéico na silicoproteinose e na proteinose alveolar; e por líquido de edema na insuficiência cardíaca congestiva.Ground-glass opacity is a finding frequently seen in high-resolution computed tomography examinations of the chest and is characterized by hazy increased attenuation of lung, however without blurring of bronchial and vascular margins. Due to its unspecificity

  14. Quantitative CT analysis of pulmonary ground-glass opacity nodules for distinguishing invasive adenocarcinoma from non-invasive or minimally invasive adenocarcinoma: the added value of using iodine mapping.

    Science.gov (United States)

    Son, Ji Ye; Lee, Ho Yun; Kim, Jae-Hun; Han, Joungho; Jeong, Ji Yun; Lee, Kyung Soo; Kwon, O Jung; Shim, Young Mog

    2016-01-01

    To determine whether quantitative analysis of iodine-enhanced images generated from dual-energy CT (DECT) have added value in distinguishing invasive adenocarcinoma from non-invasive or minimally invasive adenocarcinoma (MIA) showing ground-glass nodule (GGN). Thirty-four patients with 39 GGNs were enrolled in this prospective study and underwent DECT followed by complete tumour resection. Various quantitative imaging parameters were assessed, including virtual non-contrast (VNC) imaging and iodine-enhanced imaging. Of all 39 GGNs, four were adenocarcinoma in situ (AIS) (10 %), nine were MIA (23 %), and 26 were invasive adenocarcinoma (67 %). When assessing only VNC imaging, multivariate analysis revealed that mass, uniformity, and size-zone variability were independent predictors of invasive adenocarcinoma (odds ratio [OR] = 19.92, P = 0.02; OR = 0.70, P = 0.01; OR = 16.16, P = 0.04, respectively). After assessing iodine-enhanced imaging with VNC imaging, both mass on the VNC imaging and uniformity on the iodine-enhanced imaging were independent predictors of invasive adenocarcinoma (OR = 5.51, P = 0.04 and OR = 0.67, P VNC imaging alone, from 0.888 to 0.959, respectively (P = 0.029). Quantitative analysis using iodine-enhanced imaging metrics versus VNC imaging metrics alone generated from DECT have added value in distinguishing invasive adenocarcinoma from AIS or MIA. Quantitative analysis using DECT was used to distinguish invasive adenocarcinoma. Tumour mass and uniformity were independent predictors of invasive adenocarcinoma. Diagnostic performance was improved after adding iodine parameters to VNC parameters.

  15. Nighttime Infrared radiative cooling and opacity inferred by REMS Ground Temperature Sensor Measurements

    Science.gov (United States)

    Martín-Torres, Javier; Paz Zorzano, María; Pla-García, Jorge; Rafkin, Scot; Lepinette, Alain; Sebastián, Eduardo; Gómez-Elvira, Javier; REMS Team

    2013-04-01

    Due to the low density of the Martian atmosphere, the temperature of the surface is controlled primarily by solar heating, and infrared cooling to the atmosphere and space, rather than heat exchange with the atmosphere. In the absence of solar radiation the infrared (IR) cooling, and then the nighttime surface temperatures, are directly controlled by soil termal inertia and atmospheric optical thickness (τ) at infrared wavelengths. Under non-wind conditions, and assuming no processes involving latent heat changes in the surface, for a particular site where the rover stands the main parameter controlling the IR cooling will be τ. The minimal ground temperature values at a fixed position may thus be used to detect local variations in the total dust/aerosols/cloud tickness. The Ground Temperature Sensor (GTS) and Air Temperature Sensor (ATS) in the Rover Environmental Monitoring Station (REMS) on board the Mars Science Laboratory (MSL) Curiosity rover provides hourly ground and air temperature measurements respectively. During the first 100 sols of operation of the rover, within the area of low thermal inertia, the minimal nightime ground temperatures reached values between 180 K and 190 K. For this season the expected frost point temperature is 200 K. Variations of up to 10 K have been observed associated with dust loading at Gale at the onset of the dust season. We will use these measurements together with line-by-line radiative transfer simulations using the Full Transfer By Optimized LINe-by-line (FUTBOLIN) code [Martín-Torres and Mlynczak, 2005] to estimate the IR atmospheric opacity and then dust/cloud coverage over the rover during the course of the MSL mission. Monitoring the dust loading and IR nightime cooling evolution during the dust season will allow for a better understanding of the influence of the atmosphere on the ground temperature and provide ground truth to models and orbiter measurements. References Martín-Torres, F. J. and M. G. Mlynczak

  16. 'Seeing the Dark': Grounding Phenomenal Transparency and Opacity in Precision Estimation for Active Inference.

    Science.gov (United States)

    Limanowski, Jakub; Friston, Karl

    2018-01-01

    One of the central claims of the Self-model Theory of Subjectivity is that the experience of being someone - even in a minimal form - arises through a transparent phenomenal self-model, which itself can in principle be reduced to brain processes. Here, we consider whether it is possible to distinguish between phenomenally transparent and opaque states in terms of active inference. We propose a relationship of phenomenal opacity to expected uncertainty or precision; i.e., the capacity for introspective attention and implicit mental action. Thus we associate introspective attention with the deployment of 'precision' that may render the perceptual evidence (for action) opaque, while treating transparency as a necessary aspect of beliefs about action, i.e., 'what I am' doing. We conclude by proposing how we may have to nuance our conception of minimal phenomenal selfhood and agency in light of this active inference conception of transparency-opacity.

  17. ‘Seeing the Dark’: Grounding Phenomenal Transparency and Opacity in Precision Estimation for Active Inference

    Science.gov (United States)

    Limanowski, Jakub; Friston, Karl

    2018-01-01

    One of the central claims of the Self-model Theory of Subjectivity is that the experience of being someone – even in a minimal form – arises through a transparent phenomenal self-model, which itself can in principle be reduced to brain processes. Here, we consider whether it is possible to distinguish between phenomenally transparent and opaque states in terms of active inference. We propose a relationship of phenomenal opacity to expected uncertainty or precision; i.e., the capacity for introspective attention and implicit mental action. Thus we associate introspective attention with the deployment of ‘precision’ that may render the perceptual evidence (for action) opaque, while treating transparency as a necessary aspect of beliefs about action, i.e., ‘what I am’ doing. We conclude by proposing how we may have to nuance our conception of minimal phenomenal selfhood and agency in light of this active inference conception of transparency-opacity. PMID:29780343

  18. Reuse of ground waste glass as aggregate for mortars.

    Science.gov (United States)

    Corinaldesi, V; Gnappi, G; Moriconi, G; Montenero, A

    2005-01-01

    This work was aimed at studying the possibility of reusing waste glass from crushed containers and building demolition as aggregate for preparing mortars and concrete. At present, this kind of reuse is still not common due to the risk of alkali-silica reaction between the alkalis of cement and silica of the waste glass. This expansive reaction can cause great problems of cracking and, consequently, it can be extremely deleterious for the durability of mortar and concrete. However, data reported in the literature show that if the waste glass is finely ground, under 75mum, this effect does not occur and mortar durability is guaranteed. Therefore, in this work the possible reactivity of waste glass with the cement paste in mortars was verified, by varying the particle size of the finely ground waste glass. No reaction has been detected with particle size up to 100mum thus indicating the feasibility of the waste glass reuse as fine aggregate in mortars and concrete. In addition, waste glass seems to positively contribute to the mortar micro-structural properties resulting in an evident improvement of its mechanical performance.

  19. Pulmonary adenocarcinomas appearing as part-solid ground-glass nodules: Is measuring solid component size a better prognostic indicator?

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Eui Jin; Ryu, Youngjin; Lee, Sang Min [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, 101, Daehangno, Jongno-gu, Seoul (Korea, Republic of); Park, Chang Min; Goo, Jin Mo [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, 101, Daehangno, Jongno-gu, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Kim, Young Tae [Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Thoracic and Cardiovascular Surgery, Seoul (Korea, Republic of); Kim, Young Whan [Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul (Korea, Republic of)

    2014-10-02

    To assess whether measuring the solid portion of adenocarcinomas appearing as part-solid ground-glass nodules (GGNs) can predict a patient's prognosis accurately and how the prognosis corresponds to that of solid nodules. 501 patients (solid nodule group, 304; part-solid GGN group, 197) underwent curative surgery for stage I adenocarcinomas. Maximal diameters of the whole lesion including ground-glass opacities (D{sub whole}) and solid components only (D{sub solid}) were measured on CT. Disease-free survival (DFS) and overall survival (OS) were calculated from the date of surgery. D{sub solid} was a significant prognostic factor in the part-solid GGN group, while D{sub whole} was not. Part-solid GGNs with D{sub solid} ≤2 cm showed significantly better DFS (P = 0.016) and OS (P = 0.004) than solid nodules; however, those with D{sub solid} >2 cm did not show a significant difference. Hazard ratio (HR) for increase in D{sub solid} was significantly greater in part-solid GGNs than in solid nodules (P = 0.009). For OS, HR for increase in D{sub solid} was greater in part-solid GGNs than in solid nodule, which was marginally not significant (P = 0.060). D{sub solid} was better than D{sub whole} for prognosis prediction of adenocarcinomas appearing as part-solid GGNs. In addition, the influence of D{sub solid} on prognosis in the part-solid GGN group was greater than in the solid nodule group. (orig.)

  20. Opacity annotation of diffuse lung diseases using deep convolutional neural network with multi-channel information

    Science.gov (United States)

    Mabu, Shingo; Kido, Shoji; Hashimoto, Noriaki; Hirano, Yasushi; Kuremoto, Takashi

    2018-02-01

    This research proposes a multi-channel deep convolutional neural network (DCNN) for computer-aided diagnosis (CAD) that classifies normal and abnormal opacities of diffuse lung diseases in Computed Tomography (CT) images. Because CT images are gray scale, DCNN usually uses one channel for inputting image data. On the other hand, this research uses multi-channel DCNN where each channel corresponds to the original raw image or the images transformed by some preprocessing techniques. In fact, the information obtained only from raw images is limited and some conventional research suggested that preprocessing of images contributes to improving the classification accuracy. Thus, the combination of the original and preprocessed images is expected to show higher accuracy. The proposed method realizes region of interest (ROI)-based opacity annotation. We used lung CT images taken in Yamaguchi University Hospital, Japan, and they are divided into 32 × 32 ROI images. The ROIs contain six kinds of opacities: consolidation, ground-glass opacity (GGO), emphysema, honeycombing, nodular, and normal. The aim of the proposed method is to classify each ROI into one of the six opacities (classes). The DCNN structure is based on VGG network that secured the first and second places in ImageNet ILSVRC-2014. From the experimental results, the classification accuracy of the proposed method was better than the conventional method with single channel, and there was a significant difference between them.

  1. Ground Glass Pozzolan in Conventional, High, and Ultra-High Performance Concrete

    OpenAIRE

    Tagnit-Hamou Arezki; Zidol Ablam; Soliman Nancy; Deschamps Joris; Omran Ahmed

    2018-01-01

    Ground-glass pozzolan (G) obtained by grinding the mixed-waste glass to same fineness of cement can act as a supplementary-cementitious material (SCM), given that it is an amorphous and a pozzolanic material. The G showed promising performances in different concrete types such as conventional concrete (CC), high-performance concrete (HPC), and ultra-high performance concrete (UHPC). The current paper reports on the characteristics and performance of G in these concrete types. The use of G pro...

  2. Asset Opacity and Liquidity

    OpenAIRE

    Stenzel, A.; Wagner, W.B.

    2013-01-01

    Abstract: We consider a model of private information acquisition in which the cost of information depends on an asset's opacity. The model generates a hump-shaped relationship between opacity and the equilibrium amount of private information. In particular, the incentives to acquire information are largest for assets of intermediate opacity; such assets hence display low liquidity in the secondary market due to adverse selection. We also show that costly information acquisition generates ince...

  3. Consistent interactive segmentation of pulmonary ground glass nodules identified in CT studies

    Science.gov (United States)

    Zhang, Li; Fang, Ming; Naidich, David P.; Novak, Carol L.

    2004-05-01

    Ground glass nodules (GGNs) have proved especially problematic in lung cancer diagnosis, as despite frequently being malignant they characteristically have extremely slow rates of growth. This problem is further magnified by the small size of many of these lesions now being routinely detected following the introduction of multislice CT scanners capable of acquiring contiguous high resolution 1 to 1.25 mm sections throughout the thorax in a single breathhold period. Although segmentation of solid nodules can be used clinically to determine volume doubling times quantitatively, reliable methods for segmentation of pure ground glass nodules have yet to be introduced. Our purpose is to evaluate a newly developed computer-based segmentation method for rapid and reproducible measurements of pure ground glass nodules. 23 pure or mixed ground glass nodules were identified in a total of 8 patients by a radiologist and subsequently segmented by our computer-based method using Markov random field and shape analysis. The computer-based segmentation was initialized by a click point. Methodological consistency was assessed using the overlap ratio between 3 segmentations initialized by 3 different click points for each nodule. The 95% confidence interval on the mean of the overlap ratios proved to be [0.984, 0.998]. The computer-based method failed on two nodules that were difficult to segment even manually either due to especially low contrast or markedly irregular margins. While achieving consistent manual segmentation of ground glass nodules has proven problematic most often due to indistinct boundaries and interobserver variability, our proposed method introduces a powerful new tool for obtaining reproducible quantitative measurements of these lesions. It is our intention to further document the value of this approach with a still larger set of ground glass nodules.

  4. Strength on cut edge and ground edge glass beams with the failure analysis method

    Directory of Open Access Journals (Sweden)

    Stefano Agnetti

    2013-10-01

    Full Text Available The aim of this work is the study of the effect of the finishing of the edge of glass when it has a structural function. Experimental investigations carried out for glass specimens are presented. Various series of annealed glass beam were tested, with cut edge and with ground edge. The glass specimens are tested in four-point bending performing flaw detection on the tested specimens after failure, in order to determine glass strength. As a result, bending strength values are obtained for each specimen. Determining some physical parameter as the depth of the flaw and the mirror radius of the fracture, after the failure of a glass element, it could be possible to calculate the failure strength of that.The experimental results were analyzed with the LEFM theory and the glass strength was analyzed with a statistical study using two-parameter Weibull distribution fitting quite well the failure stress data. The results obtained constitute a validation of the theoretical models and show the influence of the edge processing on the failure strength of the glass. Furthermore, series with different sizes were tested in order to evaluate the size effect.

  5. Revitalizing the Library OPAC: Interface, Searching, and Display Challenges

    Directory of Open Access Journals (Sweden)

    Jia Mi

    2008-03-01

    Full Text Available The behavior of academic library users has drastically changed in recent years. Internet search engines have become the preferred tool over the library online public access catalog (OPAC for finding information. Libraries are losing ground to online search engines. In this paper, two aspects of OPAC use are studied: (1 the current OPAC interface and searching capabilities, and (2 the OPAC bibliographic display. The purpose of the study is to find answers to the following questions: Why is the current OPAC ineffective? What can libraries and librarians do to deliver an OPAC that is as good as search engines to better serve our users? Revitalizing the library OPAC is one of the pressing issues that has to be accomplished.

  6. Asset Opacity and Liquidity

    NARCIS (Netherlands)

    Stenzel, A.; Wagner, W.B.

    2013-01-01

    Abstract: We consider a model of private information acquisition in which the cost of information depends on an asset's opacity. The model generates a hump-shaped relationship between opacity and the equilibrium amount of private information. In particular, the incentives to acquire information are

  7. Data on the quantitative assessment pulmonary ground-glass opacification from coronary computed tomography angiography datasets

    DEFF Research Database (Denmark)

    Kühl, J Tobias; Kristensen, Thomas S; Thomsen, Anna F

    2017-01-01

    We assessed the CT attenuation density of the pulmonary tissue adjacent to the heart in patients with acute non-ST segment elevation myocardial infarction (J.T. Kuhl, T.S. Kristensen, A.F. Thomsen et al., 2016) [1]. This data was related to the level of ground-glass opacification evaluated by a r...

  8. Computer-Aided Segmentation and Volumetry of Artificial Ground-Glass Nodules at Chest CT

    NARCIS (Netherlands)

    Scholten, Ernst Th.; Jacobs, Colin; van Ginneken, Bram; Willemink, Martin J.; Kuhnigk, Jan-Martin; van Ooijen, Peter M. A.; Oudkerk, Matthijs; Mali, Willem P. Th. M.; de Jong, Pim A.

    OBJECTIVE. The purpose of this study was to investigate a new software program for semiautomatic measurement of the volume and mass of ground-glass nodules (GGNs) in a chest phantom and to investigate the influence of CT scanner, reconstruction filter, tube voltage, and tube current. MATERIALS AND

  9. Rayleigh approximation to ground state of the Bose and Coulomb glasses

    Science.gov (United States)

    Ryan, S. D.; Mityushev, V.; Vinokur, V. M.; Berlyand, L.

    2015-01-01

    Glasses are rigid systems in which competing interactions prevent simultaneous minimization of local energies. This leads to frustration and highly degenerate ground states the nature and properties of which are still far from being thoroughly understood. We report an analytical approach based on the method of functional equations that allows us to construct the Rayleigh approximation to the ground state of a two-dimensional (2D) random Coulomb system with logarithmic interactions. We realize a model for 2D Coulomb glass as a cylindrical type II superconductor containing randomly located columnar defects (CD) which trap superconducting vortices induced by applied magnetic field. Our findings break ground for analytical studies of glassy systems, marking an important step towards understanding their properties. PMID:25592417

  10. Astrophysical opacity library

    International Nuclear Information System (INIS)

    Huebner, W.F.; Merts, A.L.; Magee, N.H. Jr.; Argo, M.F.

    1977-08-01

    The astrophysical elements opacity library includes equation of state data, various mean opacities, and 2000 values of the frequency-dependent extinction coefficients in equally spaced intervals u identical with hν/kT from 0 to 20 for 41 degeneracy parameters eta from -28 (nondegenerate) to 500 and 46 temperatures kT from 1 eV to 100 keV. Among available auxiliary quantities are the free electron density, mass density, and plasma cutoff frequency. A library-associated program can produce opacities for mixtures with up to 20 astrophysically abundant constituent elements at 4 levels of utility for the user

  11. Simulations of ground state fluctuations in mean-field Ising spin glasses

    International Nuclear Information System (INIS)

    Boettcher, Stefan

    2010-01-01

    The scaling of fluctuations in the distribution of ground state energies or costs with the system size N for Ising spin glasses is considered using an extensive set of simulations with the extremal optimization heuristic across a range of different models on sparse and dense graphs. These models exhibit very diverse behaviors, and an asymptotic extrapolation is often complicated by higher-order corrections in size. The clearest picture, in fact, emerges from the study of graph bipartitioning, a combinatorial optimization problem closely related to spin glasses. Asides from two-spin interactions with discrete bonds, we also consider problems with Gaussian bonds and three-spin interactions, which behave quite differently

  12. Lanthanide/Actinide Opacities

    Science.gov (United States)

    Hungerford, Aimee; Fontes, Christopher J.

    2018-06-01

    Gravitational wave observations benefit from accompanying electromagnetic signals in order to accurately determine the sky positions of the sources. The ejecta of neutron star mergers are expected to produce such electromagnetic transients, called macronovae (e.g. the recent and unprecedented observation of GW170817). Characteristics of the ejecta include large velocity gradients and the presence of heavy r-process elements, which pose significant challenges to the accurate calculation of radiative opacities and radiation transport. Opacities include a dense forest of bound-bound features arising from near-neutral lanthanide and actinide elements. Here we present an overview of current theoretical opacity determinations that are used by neutron star merger light curve modelers. We will touch on atomic physics and plasma modeling codes that are used to generate these opacities, as well as the limited body of laboratory experiments that may serve as points of validation for these complex atomic physics calculations.

  13. Ground Glass Pozzolan in Conventional, High, and Ultra-High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Tagnit-Hamou Arezki

    2018-01-01

    Full Text Available Ground-glass pozzolan (G obtained by grinding the mixed-waste glass to same fineness of cement can act as a supplementary-cementitious material (SCM, given that it is an amorphous and a pozzolanic material. The G showed promising performances in different concrete types such as conventional concrete (CC, high-performance concrete (HPC, and ultra-high performance concrete (UHPC. The current paper reports on the characteristics and performance of G in these concrete types. The use of G provides several advantages (technological, economical, and environmental. It reduces the production cost of concrete and decrease the carbon footprint of a traditional concrete structures. The rheology of fresh concrete can be improved due to the replacement of cement by non-absorptive glass particles. Strength and rigidity improvements in the concrete containing G are due to the fact that glass particles act as inclusions having a very high strength and elastic modulus that have a strengthening effect on the overall hardened matrix.

  14. OPACs in the Clouds

    Science.gov (United States)

    Webb, Paula L.; Nero, Muriel D.

    2009-01-01

    In today's world of instant everything, everyone has been exposed to some form of Web 2.0 technology, and higher education is not exempt from its long reach. Libraries of all types are incorporating Web 2.0 features to attract users as well as to showcase library services. The Online Public Access Catalog (OPAC) has become more user-friendly with…

  15. Thus Spake the OPAC User.

    Science.gov (United States)

    Markey, Karen

    1983-01-01

    Findings of focused-group interviews conducted for OCLC study of library users and online public access catalogs (OPACs) indicate users like OPACs, have problems finding right subject heading, envision features to improve subject access, want access to more than books, and want OPACs to provide new services. Eight references are listed. (EJS)

  16. Fabrication and evaluation of hybrid materials from A-zeolite and ground glass powders for vitrified radioactive waste

    International Nuclear Information System (INIS)

    Kamitani, Masataka; Kondo, Mitsunori; Hiki, Tomonori; Tagami, Toru; Nakahira, Atsushi; Wakihara, Toru

    2014-01-01

    The samples from A-type zeolite and ground soda-lime glass powders were solidified by calcinations at 600 to 800°C in air atmosphere. These hybrid zeolite/glass samples at 700°C were in part insufficiently densified and hybrid samples were fully densified at 800°C, although the densification was not generated at 600°C. A-zeolites were still stable in glass melt at 800°C for hybrid zeolite/glass samples. These hybrid zeolite/glass samples had the ion exchange ability of 20% against Sr 2+ and the high ability over 80% against Cs + as well as A-zeolite. Microstructures of obtained hybrid zeolite/glass samples were evaluated. (author)

  17. Universe opacity and CMB

    Science.gov (United States)

    Vavryčuk, Václav

    2018-04-01

    A cosmological model, in which the cosmic microwave background (CMB) is a thermal radiation of intergalactic dust instead of a relic radiation of the Big Bang, is revived and revisited. The model suggests that a virtually transparent local Universe becomes considerably opaque at redshifts z > 2 - 3. Such opacity is hardly to be detected in the Type Ia supernova data, but confirmed using quasar data. The opacity steeply increases with redshift because of a high proper density of intergalactic dust in the previous epochs. The temperature of intergalactic dust increases as (1 + z) and exactly compensates the change of wavelengths due to redshift, so that the dust radiation looks apparently like the radiation of the blackbody with a single temperature. The predicted dust temperature is TD = 2.776 K, which differs from the CMB temperature by 1.9% only, and the predicted ratio between the total CMB and EBL intensities is 13.4 which is close to 12.5 obtained from observations. The CMB temperature fluctuations are caused by EBL fluctuations produced by galaxy clusters and voids in the Universe. The polarization anomalies of the CMB correlated with temperature anisotropies are caused by the polarized thermal emission of needle-shaped conducting dust grains aligned by large-scale magnetic fields around clusters and voids. A strong decline of the luminosity density for z > 4 is interpreted as the result of high opacity of the Universe rather than of a decline of the global stellar mass density at high redshifts.

  18. Preparation of concrete mixtures with electric arc furnace slag and recycled ground glass

    Science.gov (United States)

    Pérez Rojas, Y.; López, E. Vera; López Rodríguez, M.; Díaz Pita, J.

    2017-12-01

    The present work includes the first advances in the development of investigations that seek to include Ground Grinding Glass (GRR) and the Electric Arc Furnace Slag (EAFS) in the production of mixtures of hydraulic concrete mixing them simultaneously, so that it satisfies the specifications techniques to be used in the construction of rigid pavements. Firstly, we cite the tests carried out on the different materials to obtain their physical, chemical and mechanical characterization and determine their compliance, as well as the measurement of certain characteristics that may be somewhat empirical to standardize their control. Technique such as X-Ray Diffraction (XRD), X-ray Fluorescence Spectrometry (XFR) and Scanning Electron Microscopy (SEM) have been used. Once the results of the characterization tests and their correspondence with the Colombian technical standards have been obtained, it has become possible to select the use of the Transparent Recycled Ground Glass (TRGG) as the most suitable for the replacement of the sand in the dosage of new mixtures modified concrete.

  19. Recent progress on astrophysical opacity

    International Nuclear Information System (INIS)

    Rogers, F.J.; Iglesias, C.A.

    1992-08-01

    Improvements in the calculation of the opacity of astrophysical plasmas has helped to resolve several long-standing puzzles in the modeling of variable stars. The most significant opacity enhancements over the Los Alamos Astrophysical Library (LAOL) are due to improvements in the equation of state and atomic physics. Comparison with experiment has corroborated the predicted large opacity increases due to transitions in M-shell iron. We give a summary of recent developments

  20. Untangling complex networks: risk minimization in financial markets through accessible spin glass ground states.

    Science.gov (United States)

    Lisewski, Andreas Martin; Lichtarge, Olivier

    2010-08-15

    Recurrent international financial crises inflict significant damage to societies and stress the need for mechanisms or strategies to control risk and tamper market uncertainties. Unfortunately, the complex network of market interactions often confounds rational approaches to optimize financial risks. Here we show that investors can overcome this complexity and globally minimize risk in portfolio models for any given expected return, provided the relative margin requirement remains below a critical, empirically measurable value. In practice, for markets with centrally regulated margin requirements, a rational stabilization strategy would be keeping margins small enough. This result follows from ground states of the random field spin glass Ising model that can be calculated exactly through convex optimization when relative spin coupling is limited by the norm of the network's Laplacian matrix. In that regime, this novel approach is robust to noise in empirical data and may be also broadly relevant to complex networks with frustrated interactions that are studied throughout scientific fields.

  1. Cement plate slab production with the incorporation of glass wool waste ground

    Directory of Open Access Journals (Sweden)

    Nathany Angélica dos Santos

    Full Text Available Abstract One of the characteristics of Civil Construction is its ability to absorb a wide range of wastes to produce new products. Therefore, the objective of this study was to evaluate the behavior of cement plates produced with the addition of ground glass wool waste and in natura, in shredded form. The tensile strength tests in bending and permeability were performed, according to ABNT NBR 15498: 2007 as well as environmental ones according to ABNT NBR 10004: 2004. The plates produced in this study were characterized as being impermeable, with a satisfactory tensile strength in bending and being classified as plates for indoor and outdoor use, and as products that do not offer immediate risk to health and to the environment; however, it should be discarded in landfill.

  2. Untangling complex networks: Risk minimization in financial markets through accessible spin glass ground states

    Science.gov (United States)

    Lisewski, Andreas Martin; Lichtarge, Olivier

    2010-08-01

    Recurrent international financial crises inflict significant damage to societies and stress the need for mechanisms or strategies to control risk and tamper market uncertainties. Unfortunately, the complex network of market interactions often confounds rational approaches to optimize financial risks. Here we show that investors can overcome this complexity and globally minimize risk in portfolio models for any given expected return, provided the margin requirement remains below a critical, empirically measurable value. In practice, for markets with centrally regulated margin requirements, a rational stabilization strategy would be keeping margins small enough. This result follows from ground states of the random field spin glass Ising model that can be calculated exactly through convex optimization when relative spin coupling is limited by the norm of the network’s Laplacian matrix. In that regime, this novel approach is robust to noise in empirical data and may be also broadly relevant to complex networks with frustrated interactions that are studied throughout scientific fields.

  3. Glasses

    DEFF Research Database (Denmark)

    Dyre, Jeppe

    2004-01-01

    The temperature dependence of the viscosity of most glassforming liquids is known to depart significantly from the classical Arrhenius behaviour of simple fluids. The discovery of an unexpected correlation between the extent of this departure and the Poisson ratio of the resulting glass could lead...... to new understanding of glass ageing and viscous liquid dynamics....

  4. Web OPAC Interfaces: An Overview.

    Science.gov (United States)

    Babu, B. Ramesh; O'Brien, Ann

    2000-01-01

    Discussion of Web-based online public access catalogs (OPACs) focuses on a review of six Web OPAC interfaces in use in academic libraries in the United Kingdom. Presents a checklist and guidelines of important features and functions that are currently available, including search strategies, access points, display, links, and layout. (Author/LRW)

  5. Helioseismic Tests of Radiative Opacities.

    Energy Technology Data Exchange (ETDEWEB)

    Guzik, J. A. (Joyce Ann); Neuforge, C. M. (Corinne M.); Keady, J. J.; Magee, N. H. (Norman H.); Bradley, P. A. (Paul A.)

    2002-01-01

    During the past fifteen years, thousands of solar acoustic oscillation modes have been measured to remarkable precision, in many cases to within 0.01%. These frequencies have been used to infer the interior structure of the sun and test the physical input to solar models. Here we summarize the procedures, input physics and assumptions for calculating a standard solar evolution model. We compare the observed and calculated sound speed profile and oscillation frequencies of solar models calibrated using the new Los Alamos LEDCOP and Livermore OPAL Rosseland mean opacities for the same element mixture. We show that solar oscillations are extremely sensitive to opacities, with opacity differences of only a few percent producing an easily detectable effect on the sound speed and predicted frequencies. The oscillation data indicate that agreement would be improved by an opacity increase of several percent below the convection zone for both the LEDCOP and OPAL opacities.

  6. Pure ground glass nodular adenocarcinomas: Are preoperative positron emission tomography/computed tomography and brain magnetic resonance imaging useful or necessary?

    Science.gov (United States)

    Cho, Hyoun; Lee, Ho Yun; Kim, Jhingook; Kim, Hong Kwan; Choi, Joon Young; Um, Sang-Won; Lee, Kyung Soo

    2015-09-01

    The utility of (18)F-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scanning and brain magnetic resonance imaging (MRI) as a staging workup for lung adenocarcinoma manifesting as pure ground glass opacity (GGO) is unknown. The purpose of this study was to determine the utility of these 2 tests for preoperative staging of pure GGO nodular lung adenocarcinoma. The study included 164 patients (male:female, 73:91; mean age, 62 years) with pure GGO nodular lung adenocarcinoma who underwent PET/CT (in 136 patients) and/or brain MRI (in 109 patients) before surgery. Pathologic N staging and dedicated standard imaging or follow-up imaging findings for M staging were used as reference standards. The median follow-up time was 47.9 months. On PET/CT scan, abnormal FDG uptake of lymph nodes was found in 2 of 136 patients (1.5%); both were negative on final pathology. Abnormal FDG uptake of the liver was detected in 1 patient, which was also confirmed to be negative by dedicated abdominal CT. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT in detecting metastases were not applicable, 98% (95% confidence interval [CI], 94%-100%), 0% (95% CI, 0%-71%), 100% (95% CI, 97%-100%), and 98% (95% CI, 94%-100%), respectively. No brain metastasis was found in preoperative brain MRI of 109 patients. Of 109 patients, 1 (0.9%) developed brain metastasis 30 months after surgical resection. PET/CT and brain MRI is not necessary in the staging of pure GGO nodular lung adenocarcinoma. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  7. The ground-state energy of the ± J sping glass. A comparison of various biologically motivated algorithms

    Science.gov (United States)

    Gropengiesser, Uwe

    1995-06-01

    We compare various evlutionary strategies to determine the ground-state energy of the ± J spin glass. We show that the choice of different evolution laws is less important than a suitable treatment of the "free spins" of the system At least one combination of these strategies does not give the correct results, but the ground states of the other different strategies coincide. Therefore we are able to extrapolate the infinit-size ground-state energy for the square lattice to -1.401±0.0015 and for the simple cubic lattice to -1.786±0.004.

  8. Preoperative Prediction of Ki-67 Labeling Index By Three-dimensional CT Image Parameters for Differential Diagnosis Of Ground-Glass Opacity (GGO.

    Directory of Open Access Journals (Sweden)

    Mingzheng Peng

    Full Text Available The aim of this study was to predict Ki-67 labeling index (LI preoperatively by three-dimensional (3D CT image parameters for pathologic assessment of GGO nodules. Diameter, total volume (TV, the maximum CT number (MAX, average CT number (AVG and standard deviation of CT number within the whole GGO nodule (STD were measured by 3D CT workstation. By detection of immunohistochemistry and Image Software Pro Plus 6.0, different Ki-67 LI were measured and statistically analyzed among preinvasive adenocarcinoma (PIA, minimally invasive adenocarcinoma (MIA and invasive adenocarcinoma (IAC. Receiver operating characteristic (ROC curve, Spearman correlation analysis and multiple linear regression analysis with cross-validation were performed to further research a quantitative correlation between Ki-67 labeling index and radiological parameters. Diameter, TV, MAX, AVG and STD increased along with PIA, MIA and IAC significantly and consecutively. In the multiple linear regression model by a stepwise way, we obtained an equation: prediction of Ki-67 LI=0.022*STD+0.001* TV+2.137 (R=0.595, R's square=0.354, p<0.001, which can predict Ki-67 LI as a proliferative marker preoperatively. Diameter, TV, MAX, AVG and STD could discriminate pathologic categories of GGO nodules significantly. Ki-67 LI of early lung adenocarcinoma presenting GGO can be predicted by radiologic parameters based on 3D CT for differential diagnosis.

  9. Size effect model for the edge strength of glass with cut and ground edge finishing

    NARCIS (Netherlands)

    Vandebroek, M.; Louter, C.; Caspeele, R.; Ensslen, F.; Belis, J.L.I.F.

    2014-01-01

    The edge strength of glass is influenced by the size of the surface (near the edge) which is subjected to tensile stresses. To quantify this size effect, 8 series of single layer annealed glass beam specimens (as-received glass) were subjected to in-plane four-point bending with linearly increased

  10. Software-based risk stratification of pulmonary adenocarcinomas manifesting as pure ground glass nodules on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, Ursula [Vienna General Hospital, Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Heidinger, Benedikt H.; Bankier, Alexander A. [Harvard Medical School, Radiology, Beth Israel Deaconess Medical Center, Boston, MA (United States); Anderson, Kevin R.; VanderLaan, Paul A. [Harvard Medical School, Pathology, Beth Israel Deaconess Medical Center, Boston, MA (United States); Westmore, Michael S. [Imbio, Delafield, WI (United States)

    2018-01-15

    To assess the performance of the ''Computer-Aided Nodule Assessment and Risk Yield'' (CANARY) software in the differentiation and risk assessment of histological subtypes of lung adenocarcinomas manifesting as pure ground glass nodules on computed tomography (CT). 64 surgically resected and histologically proven adenocarcinomas manifesting as pure ground-glass nodules on CT were assessed using CANARY software, which classifies voxel-densities into three risk components (low, intermediate, and high risk). Differences in risk components between histological adenocarcinoma subtypes were analysed. To determine the optimal threshold reflecting the presence of an invasive focus, sensitivity, specificity, negative predictive value, and positive predictive value were calculated. 28/64 (44%) were adenocarcinomas in situ (AIS); 26/64 (41%) were minimally invasive adenocarcinomas (MIA); and 10/64 (16%) were invasive ACs (IAC). The software showed significant differences in risk components between histological subtypes (P<0.001-0.003). A relative volume of 45% or less of low-risk components was associated with histological invasiveness (specificity 100%, positive predictive value 100%). CANARY-based risk assessment of ACs manifesting as pure ground glass nodules on CT allows the differentiation of their histological subtypes. A threshold of 45% of low-risk components reflects invasiveness in these groups. (orig.)

  11. Software-based risk stratification of pulmonary adenocarcinomas manifesting as pure ground glass nodules on computed tomography

    International Nuclear Information System (INIS)

    Nemec, Ursula; Heidinger, Benedikt H.; Bankier, Alexander A.; Anderson, Kevin R.; VanderLaan, Paul A.; Westmore, Michael S.

    2018-01-01

    To assess the performance of the ''Computer-Aided Nodule Assessment and Risk Yield'' (CANARY) software in the differentiation and risk assessment of histological subtypes of lung adenocarcinomas manifesting as pure ground glass nodules on computed tomography (CT). 64 surgically resected and histologically proven adenocarcinomas manifesting as pure ground-glass nodules on CT were assessed using CANARY software, which classifies voxel-densities into three risk components (low, intermediate, and high risk). Differences in risk components between histological adenocarcinoma subtypes were analysed. To determine the optimal threshold reflecting the presence of an invasive focus, sensitivity, specificity, negative predictive value, and positive predictive value were calculated. 28/64 (44%) were adenocarcinomas in situ (AIS); 26/64 (41%) were minimally invasive adenocarcinomas (MIA); and 10/64 (16%) were invasive ACs (IAC). The software showed significant differences in risk components between histological subtypes (P<0.001-0.003). A relative volume of 45% or less of low-risk components was associated with histological invasiveness (specificity 100%, positive predictive value 100%). CANARY-based risk assessment of ACs manifesting as pure ground glass nodules on CT allows the differentiation of their histological subtypes. A threshold of 45% of low-risk components reflects invasiveness in these groups. (orig.)

  12. Quantitative CT analysis of pulmonary pure ground-glass nodule predicts histological invasiveness

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qiong, E-mail: liqiongsmmu2008@qq.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China); Fan, Li, E-mail: fanli0930@163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China); Cao, En-Tao, E-mail: cet123cs@126.com [Department of Radiology, Suzhou Municipal Hospital (East District), No.16 West Baita Road, Suzhu, Jiangsu Province 215001 (China); Li, Qing-Chu, E-mail: Wudi327@hotmail.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China); Gu, Ya-Feng, E-mail: 2528473557@qq.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China); Liu, Shi−Yuan, E-mail: liusy1186@163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, NO. 415, Fengyang Road, Shanghai 200003 (China)

    2017-04-15

    Objective: To assess whether quantitative computed tomography (CT) can help predict histological invasiveness of pulmonary adenocarcinoma appearing as pure ground glass nodules (pGGNs). Methods: A total of 110 pulmonary pGGNs were retrospectively evaluated, and pathologically classified as pre-invasive lesions, minimally invasive adenocarcinoma (MIA) and invasive pulmonary adenocarcinoma (IPA). Maximum nodule diameters, largest cross-sectional areas, volumes, mean CT values, weights, and CT attenuation values at the 0th,2th,5th, 25th, 50th,75th, 95th, 98th and100th percentiles on histogram, as well as 2th to 98th, 5th to 95th, 25th to 75th,and 0th to 100thslopes, respectively, were compared among the three groups. Results: Of the 110 pGGNs, 50, 28, and 32 were pre-invasive lesions, MIA, and IPA, respectively. Maximum nodule diameters, largest cross-sectional areas, andmass weights were significantly larger in the IPA group than in pre-invasive lesions. The 95th, 98th, 100th percentiles, and 2th to 98th, 25th to 75th, and 0th to 100thslopes were significantly different between pre-invasive lesions and MIA or IPA. Logistic regression analysis showed that the maximum nodule diameter (OR = 1.21, 95%CI: 1.071–1.366, p < 0.01) and 100th percentile on histogram (OR = 1.02, 95%CI: 1.009–1.032, p < 0.001) independently predicted histological invasiveness. Conclusions: Quantitative analysis of CT imaging can predict histological invasiveness of pGGNs, especiallythe maximum nodule diameter and 100th percentile on CT number histogram; this can instruct the long-term follow-up and selective surgical management.

  13. High ion-exchange properties of hybrid materials from X-type zeolite and ground glass powder

    Science.gov (United States)

    Taira, Nobuyuki; Yoshida, Kohei

    2017-10-01

    Zeolites are crystalline aluminosilicates with a homogeneous distribution of micropores with a superior cation-exchange capacity. Because they have especially excellent selective exchange properties, a considerable number of studies have been conducted on treating water containing radioisotopes using the zeolites. When using artificial zeolites, they have inferior sinterability; in addition, it is quite hard for them to remove from polluted liquid since these artificial zeolites are principally synthesized as a form of powder, which is a disadvantage. In this study, hybrid materials were prepared from X-type zeolite and waste glass powder. Their ion-removal effect and mechanical strength were investigated. The zeolite and waste glass were ground in an agate mortar in several ratios. 0.5 g of the mixture was pressure-molded into pellets having a diameter of 7 mm. These pellets were slowly heated at the speed of 240°C/h to 700°C and maintained at 700°C for 2 h. The removal rate of Sr2+ ions increased as the amount of X-type zeolite in the hybrid materials increased; the former increased up to 100% when the content of latter exceeded 50%. The mechanical strength increased by increasing the amount of glass in the hybrid materials. This is attributed to the fact that the glass powder acts as a binder that improves the densification and consequently the mechanical strength of the hybrid materials.

  14. The long-term corrosion of glass by ground-water

    International Nuclear Information System (INIS)

    Cox, G.A.; Ford, B.A.

    1993-01-01

    Specimens of corroded soda and potash glasses, which had been exposed to groundwater for periods of up to about 1650 years, have been physically and chemically analysed. The morphology and compositional profiles of their finely laminated weathering crusts were determined by scanning electron microscopy and electron-probe microanalysis. It is shown that the surface layers on all specimens are depleted, to varying extents, of their principal constituents, with the exception of Si, Al and Fe. X-ray and electron diffraction studies have revealed the (tentative) identities of complex, poorly crystalline silicates and aluminosilicates within the largely amorphous crusts on potash glasses. The mean thickness of the crusts was found to correlate well with the free energy of hydration, ΔG o , of the pristine glasses. The rate of layer formation on the most durable specimens (ΔG o ∼ -15 kJ mol -1 ) was about 4 x 10 -3 μm year -1 . Deposits of calcite, calcium phosphate and manganese rich minerals occurred within the crusts; they were largely of external origin. Thus, in addition to the composition of the glass, the geochemistry of the local groundwater plays a decisive role in determining the identity of the compounds present within the weathering crusts. (author)

  15. LINE BROADENING AND THE SOLAR OPACITY PROBLEM

    Energy Technology Data Exchange (ETDEWEB)

    Krief, M.; Feigel, A.; Gazit, D., E-mail: menahem.krief@mail.huji.ac.il [The Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel)

    2016-06-20

    The calculation of line widths constitutes theoretical and computational challenges in the calculation of opacities of hot, dense plasmas. Opacity models use line broadening approximations that are untested at stellar interior conditions. Moreover, calculations of atomic spectra of the Sun indicate a large discrepancy in the K-shell line widths between several atomic codes and the Opacity-Project (OP). In this work, the atomic code STAR is used to study the sensitivity of solar opacities to line broadening. Variations in the solar opacity profile due to an increase of the Stark widths resulting from discrepancies with OP, are compared, in light of the solar opacity problem, with the required opacity variations of the present day Sun, as imposed by helioseismic and neutrino observations. The resulting variation profile is much larger than the discrepancy between different atomic codes, agrees qualitatively with the missing opacity profile, recovers about half of the missing opacity nearby the convection boundary, and has a little effect in the internal regions. Since it is hard to estimate quantitatively the uncertainty in the Stark widths, we show that an increase of all line widths by a factor of about ∼100 recovers quantitatively the missing opacity. These results emphasize the possibility that photoexcitation processes are not modeled properly, and more specifically, highlight the need for a better theoretical characterization of the line broadening phenomena at stellar interior conditions, and of the uncertainty due to the way it is implemented by atomic codes.

  16. Some investigations about the Carson opacities

    International Nuclear Information System (INIS)

    Cox, A.N.; Kidman, R.B.

    1983-01-01

    Accurate opacities for stellar composition mixtures are needed for all studies of stellar structure, evolution, stability, and pulsation. Three problem areas where increased opacities would be welcome are: the observed broadening of the upper main sequence that can be produced with larger opacities that tend to expand the stars; the existence of the double-mode Cepheids and their anomalously low period ratios which can be predicted to be lower, as observed, if opacities are larger; and the small sensitivity of the low mass population II horizontal branch luminosity to the metal content of their compositions that would be more effective if their opacity were increased. Several other problems that could be solved by larger opacities have been widely discussed, but we feel that they are not justifiably an opacity problem. The conclusion of our considerations are that the Thomas-Fermi method for getting opacities used by Carson and his collaborators does not produce values appreciably different from those obtained without this method at Los Alamos, and that these persistent astrophysical problems must be solved in other ways. We here propose a possible error in the Carson opacities, and, further, we mention another that seems to be the correct reconciliation between these two opacity sets

  17. Ground-state magnetization of the Ising spin glass: A recursive numerical method and Chen-Ma scaling

    Science.gov (United States)

    Sepehrinia, Reza; Chalangari, Fartash

    2018-03-01

    The ground-state properties of quasi-one-dimensional (Q1D) Ising spin glass are investigated using an exact numerical approach and analytical arguments. A set of coupled recursive equations for the ground-state energy are introduced and solved numerically. For various types of coupling distribution, we obtain accurate results for magnetization, particularly in the presence of a weak external magnetic field. We show that in the weak magnetic field limit, similar to the 1D model, magnetization exhibits a singular power-law behavior with divergent susceptibility. Remarkably, the spectrum of magnetic exponents is markedly different from that of the 1D system even in the case of two coupled chains. The magnetic exponent makes a crossover from being dependent on a distribution function to a constant value independent of distribution. We provide an analytic theory for these observations by extending the Chen-Ma argument to the Q1D case. We derive an analytical formula for the exponent which is in perfect agreement with the numerical results.

  18. Through the looking glass: Applications of ground-penetrating radar in archaeology

    Science.gov (United States)

    Stamos, Antonia

    The focus of this dissertation is to present the results of four years' worth of geophysical surveying at four major archaeological sites in Greece and the benefits to the archaeological community. The ground penetrating radar offers an inexpensive, non-destructive solution to the problem of deciding how much of a site is worth excavating and which areas would yield the most promising results. An introduction to the ground penetrating radar, or GPR, the equipment necessary to conduct a geophysical survey in the field, and the methods of data collection and subsequent data processing are all addressed. The benefits to the archeological community are many, and future excavations will incorporate such an important tool for a greater understanding of the site. The history of GPR work in the archaeological field has grown at an astounding rate from its beginnings as a simple tool for petroleum and mining services in the beginning of the twentieth century. By mid-century, the GPR was first applied to archaeological sites rather than its common use by utility companies in locating pipes, cables, tunnels, and shafts. Although the preliminary surveys were little more than a search to locate buried walls, the success of these initial surveys paved the ground for future surveys at other archaeological sites, many testing the radar's efficacy with a myriad of soil conditions and properties. The four sites in which geophysical surveys with a ground penetrating radar were conducted are Azorias on the island of Crete, Kolonna on the island of Aegina, Mochlos Island and Coastal Mochlos on the island of Crete, and Mycenae in the Peloponnese on mainland Greece. These case studies are first presented in terms of their geographical location, their mythology and etymology, where applicable, along with a brief history of excavation and occupation of the site. Additional survey methods were used at Mycenae, including aerial photography and ERDAS Imagine, a silo locating program now

  19. Triviality of the ground-state metastate in long-range Ising spin glasses in one dimension

    Science.gov (United States)

    Read, N.

    2018-01-01

    We consider the one-dimensional model of a spin glass with independent Gaussian-distributed random interactions, which have mean zero and variance 1/|i -j | 2 σ, between the spins at sites i and j for all i ≠j . It is known that, for σ >1 , there is no phase transition at any nonzero temperature in this model. We prove rigorously that, for σ >3 /2 , any translation-covariant Newman-Stein metastate for the ground states (i.e., the frequencies with which distinct ground states are observed in finite-size samples in the limit of infinite size, for given disorder) is trivial and unique. In other words, for given disorder and asymptotically at large sizes, the same ground state, or its global spin flip, is obtained (almost) always. The proof consists of two parts: One is a theorem (based on one by Newman and Stein for short-range two-dimensional models), valid for all σ >1 , that establishes triviality under a convergence hypothesis on something similar to the energies of domain walls and the other (based on older results for the one-dimensional model) establishes that the hypothesis is true for σ >3 /2 . In addition, we derive heuristic scaling arguments and rigorous exponent inequalities which tend to support the validity of the hypothesis under broader conditions. The constructions of various metastates are extended to all values σ >1 /2 . Triviality of the metastate in bond-diluted power-law models for σ >1 is proved directly.

  20. Serendipity and Holism: The Beauty of OPACs.

    Science.gov (United States)

    Rice, James

    1988-01-01

    Identifies factors which may account for user dissatisfaction with online public access catalogs (OPACs) and discusses some advantages of OPACs over card catalogs: (1) design for subject searching; (2) flexibility; (3) browsing capability; (4) precision; (5) availability of status information; and (6) development of microcomputer software to…

  1. Using Web Services for a Mobile OPAC

    Directory of Open Access Journals (Sweden)

    Denis Galvin

    2011-04-01

    Full Text Available The purpose of this paper is to discuss the creation and intended evolution of the Rice University mobile online public access catalog (OPAC. The focus of the article is on how SirsiDynix’s Symphony Web Services can be used to create a mobile OPAC.

  2. Restricted fish feeding reduces cod otolith opacity

    DEFF Research Database (Denmark)

    Høie, H.; Folkvord, A.; Mosegaard, Henrik

    2008-01-01

    The purpose of this work was to examine the effect of reduced feeding and constant temperature on cod otolith opacity. Three groups of juvenile cod were given restricted food rations at different times for 4 months, resulting in depressed somatic growth. Otolith opacity was measured on pictures...... in otolith opacity were found between individual fish both within groups and between groups. In two of the three groups significantly more translucent otolith material was deposited in response to reduced feeding. Our results show that variations in feeding and hence fish growth resulted in variation...... in otolith opacity, but the effect was minor compared to that of variations in ambient temperature. The combined influence of these effects, which both act on fish metabolism, are most likely controlling the seasonal opacity changes observed in wild fish. Our results help explain the variations seen in fish...

  3. Opacity Limit for Supermassive Protostars

    Science.gov (United States)

    Becerra, Fernando; Marinacci, Federico; Inayoshi, Kohei; Bromm, Volker; Hernquist, Lars E.

    2018-04-01

    We present a model for the evolution of supermassive protostars from their formation at {M}\\star ≃ 0.1 {M}ȯ until their growth to {M}\\star ≃ {10}5 {M}ȯ . To calculate the initial properties of the object in the optically thick regime, we follow two approaches: one based on idealized thermodynamic considerations, and another based on a more detailed one-zone model. Both methods derive a similar value of {n}{{F}}≃ 2× {10}17 {cm}}-3 for the density of the object when opacity becomes important, i.e., the opacity limit. The subsequent evolution of the growing protostar is determined by the accretion of gas onto the object and can be described by a mass–radius relation of the form {R}\\star \\propto {M}\\star 1/3 during the early stages, and of the form {R}\\star \\propto {M}\\star 1/2 when internal luminosity becomes important. For the case of a supermassive protostar, this implies that the radius of the star grows from {R}\\star ≃ 0.65 {au} to {R}\\star ≃ 250 {au} during its evolution. Finally, we use this model to construct a subgrid recipe for accreting sink particles in numerical simulations. A prime ingredient thereof is a physically motivated prescription for the accretion radius and the effective temperature of the growing protostar embedded inside it. From the latter, we can conclude that photoionization feedback can be neglected until very late in the assembly process of the supermassive object.

  4. Opacity calculations for laser plasma applications

    International Nuclear Information System (INIS)

    Magee, N.H. Jr.

    1986-01-01

    The Los Alamos LTE light element detailed configuration opacity code (LEDCOP) has been revised to provide more accurate absorption coefficients and group means for modern radiation-hydrodynamic codes. The new group means will be especially useful for computing the transport of thermal radiation from laser deposition. The principal improvement is the inclusion of a complete set of accurate and internally consistent LS term energies and oscillator strengths in both the EOS and absorption coefficients. Selected energies and oscillator strengths were calculated from a Hartree-Fock code, then fitted by a quantum defect method. This allowed transitions at all wavelengths to be treated consistently and accurately instead of being limited to wavelength regions covered by experimental observations or isolated theoretical calculations. A second improvement is the use of more accurate photoionization cross sections for excited as well as ground state configurations. These cross sections are now more consistent with the bound-bound oscillator strengths, leading to a smooth transition across the continuum limit. Results will be presented showing the agreement of the LS term energies and oscillator strengths with observed values. The new absorption coefficients will be compared with previous calculations. 5 refs., 9 figs., 1 tab

  5. CT and histopathologic characteristics of lung adenocarcinoma with pure ground-glass nodules 10 mm or less in diameter

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Fang [Chinese PLA General Hospital, Department of Radiology, Beijing (China); Capital Medical University, Department of Radiology, Xuanwu Hospital, Beijing (China); Tian, Shu-ping [Navy General Hospital, Department of Radiology, Beijing (China); Jin, Xin; Jing, Rui; Yang, Yue-qing; Jin, Mei; Zhao, Shao-hong [Chinese PLA General Hospital, Department of Radiology, Beijing (China)

    2017-10-15

    To evaluate CT and histopathologic features of lung adenocarcinoma with pure ground-glass nodule (pGGN) ≤10 mm in diameter. CT appearances of 148 patients (150 lesions) who underwent curative resection of lung adenocarcinoma with pGGN ≤10 mm (25 atypical adenomatous hyperplasias, 42 adenocarcinoma in situs, 38 minimally invasive adenocarcinomas, and 45 invasive pulmonary adenocarcinomas) were analyzed for lesion size, density, bubble-like sign, air bronchogram, vessel changes, margin, and tumour-lung interface. CT characteristics were compared among different histopathologic subtypes. Univariate and multivariate analysis were used to assess the relationship between CT characteristics of pGGN and lesion invasiveness, respectively. There were statistically significant differences among histopathologic subtypes in lesion size, vessel changes, and tumour-lung interface (P<0.05). Univariate analysis revealed significant differences of vessel changes, margin and tumour-lung interface between preinvasive and invasive lesions (P<0.05). Logistic regression analysis showed that the vessel changes, unsmooth margin and clear tumour-lung interface were significant predictive factors for lesion invasiveness, with odds ratios (95% CI) of 2.57 (1.17-5.62), 1.83 (1.25-2.68) and 4.25 (1.78-10.14), respectively. Invasive lesions are found in 55.3% of subcentimeter pGGNs in our cohort. Vessel changes, unsmooth margin, and clear lung-tumour interface may indicate the invasiveness of lung adenocarcinoma with subcentimeter pGGN. (orig.)

  6. Multi-detector spiral CT study of the relationships between pulmonary ground-glass nodules and blood vessels

    International Nuclear Information System (INIS)

    Gao, Feng; Li, Ming; Ge, Xiaojun; Ren, Qingguo; Hua, Yanqing; Zheng, Xiangpeng; Chen, Yan; Lv, Fangzhen

    2013-01-01

    To investigate the relationships between pulmonary ground-glass nodules (GGN) and blood vessels and their diagnostic values in differentiating GGNs. Multi-detector spiral CT imaging of 108 GGNs was retrospectively reviewed. The spatial relationships between GGNs and supplying blood vessels were categorized into four types: I, vessels passing by GGNs; II, intact vessels passing through GGNs; III, distorted, dilated or tortuous vessels seen within GGNs; IV, more complicated vasculature other than described above. Relationship types were correlated to pathologic and/or clinical findings of GGNs. Of 108 GGNs, 10 were benign, 24 preinvasive nodules and 74 adenocarcinomas that were pathologically proven. Types I, II, III and IV vascular relationships were observed in 9, 58, 21 and 20 GGNs, respectively. Type II relationship was the dominating relationship for each GGN group, but significant differences were shown among them. Correlation analysis showed strong correlation between invasive adenocarcinoma and type III and IV relationships. Subgroup analysis indicated that type III was more commonly seen in IAC with comparison to type IV more likely seen in MIA. Different GGNs have different relationships with vessels. Understanding and recognising characteristic GGN-vessel relationships may help identify which GGNs are more likely to be malignant. (orig.)

  7. Model of opacity and emissivity of non-equilibrium plasma

    International Nuclear Information System (INIS)

    Politov V Y

    2008-01-01

    In this work the model describing absorption and emission properties of the non-equilibrium plasma is presented. It is based on the kinetics equations for populations of the ground, singly and doubly excited states of multi-charged ions. After solving these equations, the states populations together with the spectroscopic data, supplied in the special database for a lot ionization stages, are used for building the spectral distributions of plasma opacity and emissivity in STA approximation. Results of kinetics simulation are performed for such important X-ray converter as gold, which is investigated intensively in ICF-experiments

  8. New Generation of Los Alamos Opacity Tables

    Science.gov (United States)

    Colgan, James; Kilcrease, D. P.; Magee, N. H.; Sherrill, M. E.; Abdallah, J.; Hakel, P.; Fontes, C. J.; Guzik, J. A.; Mussack, K. A.

    2016-05-01

    We present a new generation of Los Alamos OPLIB opacity tables that have been computed using the ATOMIC code. Our tables have been calculated for all 30 elements from hydrogen through zinc and are publicly available through our website. In this poster we discuss the details of the calculations that underpin the new opacity tables. We also show several recent applications of the use of our opacity tables to solar modeling and other astrophysical applications. In particular, we demonstrate that use of the new opacities improves the agreement between solar models and helioseismology, but does not fully resolve the long-standing `solar abundance' problem. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396.

  9. The neutrino opacity of neutron rich matter

    Energy Technology Data Exchange (ETDEWEB)

    Alcain, P.N., E-mail: pabloalcain@gmail.com [Departamento de Física, FCEyN, UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina); IFIBA-CONICET (Argentina); Dorso, C.O. [Departamento de Física, FCEyN, UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina); IFIBA-CONICET (Argentina)

    2017-05-15

    The study of neutron rich matter, present in neutron star, proto-neutron stars and core-collapse supernovae, can lead to further understanding of the behavior of nuclear matter in highly asymmetric nuclei. Heterogeneous structures are expected to exist in these systems, often referred to as nuclear pasta. We have carried out a systematic study of neutrino opacity for different thermodynamic conditions in order to assess the impact that the structure has on it. We studied the dynamics of the neutrino opacity of the heterogeneous matter at different thermodynamic conditions with semiclassical molecular dynamics model already used to study nuclear multifragmentation. For different densities, proton fractions and temperature, we calculate the very long range opacity and the cluster distribution. The neutrino opacity is of crucial importance for the evolution of the core-collapse supernovae and the neutrino scattering.

  10. Update on the opal opacity code

    International Nuclear Information System (INIS)

    Rogers, F.J.; Iglesias, C.A.; Wilson, B.G.

    1990-01-01

    Persisting discrepancies between theory and observation in a number of astrophysical properties has led to the conjecture that opacity databases may be inaccurate. The OPAL opacity code has been developed to address this question. The physical basis of OPAL removes several of the approximations present in past calculations. For example, it utilizes a much larger and more detailed set of atomic data than was used to construct the los Alamos Astrophysical Library. This data is generated online, in LS or intermediate coupling, from prefitted analytic effective potentials and is of similar quality as single configuration, relativistic, self-consistent-field calculations. The OPAL code has been used to calculate opacities for the solar core and for Cepheid variable stars. In both cases, significant increases in the opacity compared to the Los Alamos Astrophysical Library were found

  11. Summary of Fe opacity measurement platform

    Energy Technology Data Exchange (ETDEWEB)

    Nagayama, Taisuke

    2016-05-01

    This powerpoint presentation goes over the Fe opacity measurement platform, including how the experiment works, what can be gathered from the measurements, what can be gathered from the simulations, and the limitations of the experiment.

  12. Electrocardiography-triggered high-resolution CT for reducing cardiac motion artifact. Evaluation of the extent of ground-glass attenuation in patients with idiopathic pulmonary fibrosis

    International Nuclear Information System (INIS)

    Nishiura, Motoko; Johkoh, Takeshi; Yamamoto, Shuji

    2007-01-01

    The aim of this study was to evaluate the decreasing of cardiac motion artifact and whether the extent of ground-glass attenuation of idiopathic pulmonary fibrosis (IPF) was accurately assessed by electrocardiography (ECG)-triggered high-resolution computed tomography (HRCT) by 0.5-s/rotation multidetector-row CT (MDCT). ECG-triggered HRCT were scanned at the end-diastolic phase by a MDCT scanner with the following scan parameters; axial four-slice mode, 0.5 mm collimation, 0.5-s/rotation, 120 kVp, 200 mA/rotation, high-frequency algorithm, and half reconstruction. In 42 patients with IPF, both conventional HRCT (ECG gating (-), full reconstruction) and ECG-triggered HRCT were performed at the same levels (10-mm intervals) with the above scan parameters. The correlation between percent diffusion of carbon monoxide of the lung (%DLCO) and the mean extent of ground-glass attenuation on both conventional HRCT and ECG-triggered HRCT was evaluated with the Spearman rank correlation coefficient test. The correlation between %DLCO and the mean extent of ground-glass attenuation on ECG-triggered HRCT (observer A: r=-0.790, P<0.0001; observer B: r=-0.710, P<0.0001) was superior to that on conventional HRCT (observer A: r=-0.395, P<0.05; observer B: r=-0.577, P=0.002) for both observers. ECG-triggered HRCT by 0.5 s/rotation MDCT can reduce the cardiac motion artifact and is useful for evaluating the extent of ground-glass attenuation of IPF. (author)

  13. Detailed Opacity Calculations for Astrophysical Applications

    Directory of Open Access Journals (Sweden)

    Jean-Christophe Pain

    2017-05-01

    Full Text Available Nowadays, several opacity codes are able to provide data for stellar structure models, but the computed opacities may show significant differences. In this work, we present state-of-the-art precise spectral opacity calculations, illustrated by stellar applications. The essential role of laboratory experiments to check the quality of the computed data is underlined. We review some X-ray and XUV laser and Z-pinch photo-absorption measurements as well as X-ray emission spectroscopy experiments involving hot dense plasmas produced by ultra-high-intensity laser irradiation. The measured spectra are systematically compared with the fine-structure opacity code SCO-RCG. The focus is on iron, due to its crucial role in understanding asteroseismic observations of β Cephei-type and Slowly Pulsating B stars, as well as of the Sun. For instance, in β Cephei-type stars, the iron-group opacity peak excites acoustic modes through the “kappa-mechanism”. Particular attention is paid to the higher-than-predicted iron opacity measured at the Sandia Z-machine at solar interior conditions. We discuss some theoretical aspects such as density effects, photo-ionization, autoionization or the “filling-the-gap” effect of highly excited states.

  14. Seven-microRNA panel for lung adenocarcinoma early diagnosis in patients presenting with ground-glass nodules

    Directory of Open Access Journals (Sweden)

    He Y

    2017-12-01

    Full Text Available Yayi He,1,2,* Yang Yang,3,* Peng Kuang,1 Shengxiang Ren,1 Leslie Rozeboom,2 Christopher J Rivard,2 Xuefei Li,4 Caicun Zhou,1 Fred R Hirsch2 1Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, People’s Republic of China; 2Division of Medical Oncology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; 3Department of Surgery, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, 4Department of Lung Cancer and Immunology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: MicroRNA (miRNA expression is correlated with tumor histology, differentiation, invasiveness and treatment outcome. We aimed to identify miRNAs whose differential expression might enable early diagnosis of lung adenocarcinoma in patients presenting with ground-glass nodules (GGNs.Methods: To identify potential miRNAs of interest, we analyzed the miRNA expression profile of tumor and adjacent non-para-tumor tissue in three participants by next-generation sequencing (NGS. We then assessed the expression levels of the miRNAs of interest in 73 lung adenocarcinomas presenting with GGNs with matched adjacent non-tumor tissue by quantitative real-time polymerase chain reaction (qRT-PCR. We also detected the miRNA panel in 66 lung benign diseases and 66 lung adenocarcinomas presenting with GGN lesion tissues by qRT-PCR. Target genes of our selected miRNA panel were predicted using Miranda with default parameters.Results: Twenty-three miRNAs showed differential expression between tumor and adjacent non-tumor tissue by NGS. Five miRNAs exhibited higher expression in tumor tissue compared to adjacent non-tumor tissue (P

  15. Application of positron emission tomography-computed tomography in the diagnosis of pulmonary ground-glass nodules.

    Science.gov (United States)

    Hu, Lili; Pan, Yuanwei; Zhou, Zhigang; Gao, Jianbo

    2017-11-01

    The aim of the present study was to investigate the value of positron emission tomography-computed tomography (PET-CT) using 18 F-fluorodeoxyglucose in the clinical diagnosis of pulmonary ground-glass nodule. In total, 54 patients with pulmonary GGN that were identified by PET-CT examination were selected and confirmed by pathology and clinical diagnosis in hospital between April 2014 and April 2015. The association between PET-CT findings and pathology, and the value of PET-CT were then evaluated. In the 54 patients, solitary pulmonary GGN with a nodule diameter of between 0.6 and 2.0 cm were detected. Amongst them, the PET-CT examination of 42 patients revealed hyper metabolic nodules, and were all mixed GGN type nodules with a diameter >1 cm. The PET-CT examination of the remaining 12 patients demonstrated no evidence of metabolic abnormalities and the nodules in these patients were pure or mixed GGN with a diameter <1 cm (except 2 cases with a diameter ≥1 cm). Furthermore, the diagnoses for all patients were pathologically confirmed by CT-guided needle biopsy or thoracoscopic surgical resection. Amongst them, there were 41 cases of lung adenocarcinoma, 4 cases of fungal infection, 7 cases of inflammation and 2 cases of adenomatoid hyperplasia. Additionally, PET-CT has a lower detection rate for smaller GGN exhibits no clear advantage for pure GGN, but has a higher detection rate for larger GGN. In conclusion, to a certain extent, PET-CT makes up for the shortcomings of traditional imaging and has some clinical value for the diagnosis of GGN.

  16. Heat transfer performance of the OPAC 106 heat exchanger; Warmte-overdrachtsprestaties van de OPAC106 warmtewisselaar

    Energy Technology Data Exchange (ETDEWEB)

    De Zwart, H.F.; Janssen, H.J.J. [Wageningen UR Glastuinbouw, Wageningen (Netherlands)

    2010-10-15

    The heat transfer performance of a new type compact heat exchanger were studied. It concerns the OPAC106, developed for the horticultural sector. The OPAC 106 combines a compact size with high heat transfer at low consumption of electricity for air circulation. OPAC stands for Oval Pipe Air Conditioner [Dutch] De warmte-overdrachtprestaties van een nieuw type compacte warmtewisselaar zijn bestudeerd. Het betreft de OPAC106, een speciaal voor de tuinbouw ontwikkelde warmtewisselaar. OPAC betekent Ovale Pijpen Air Conditioner.

  17. OPserver: opacities and radiative accelerations on demand

    Science.gov (United States)

    Mendoza, C.; González, J.; Seaton, M. J.; Buerger, P.; Bellorín, A.; Meléndez, M.; Rodríguez, L. S.; Delahaye, F.; Zeippen, C. J.; Palacios, E.; Pradhan, A. K.

    2009-05-01

    We report on developments carried out within the Opacity Project (OP) to upgrade atomic database services to comply with e-infrastructure requirements. We give a detailed description of an interactive, online server for astrophysical opacities, referred to as OPserver, to be used in sophisticated stellar modelling where Rosseland mean opacities and radiative accelerations are computed at every depth point and each evolution cycle. This is crucial, for instance, in chemically peculiar stars and in the exploitation of the new asteroseismological data. OPserver, downloadable with the new OPCD_3.0 release from the Centre de Données Astronomiques de Strasbourg, France, computes mean opacities and radiative data for arbitrary chemical mixtures from the OP monochromatic opacities. It is essentially a client-server network restructuring and optimization of the suite of codes included in the earlier OPCD_2.0 release. The server can be installed locally or, alternatively, accessed remotely from the Ohio Supercomputer Center, Columbus, Ohio, USA. The client is an interactive web page or a subroutine library that can be linked to the user code. The suitability of this scheme in grid computing environments is emphasized, and its extension to other atomic database services for astrophysical purposes is discussed.

  18. Ground glass hepatocytes provide targets for therapy or prevention of hepatitis B virus-related hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Hong-Yi Chang

    2018-03-01

    Full Text Available Ground glass hepatocyte (GGH represents a histologic hallmark of chronic hepatitis B virus (HBV infection and is characterized by the accumulation of pre-S mutant surface antigens in the endoplasmic reticulum (ER. In the past decade, GGHs have been recognized as pre-neoplastic lesions of hepatocellular carcinoma (HCC. The accumulation of pre-S mutant protein in ER may induce a misfolded protein response or ER stress signals with activation of VEGF/Akt/mTOR and COX-2/NF-κB signals, leading to oxidative DNA damage, aneuploidy, and genomic instability. Molecular studies revealed clonal HBV DNA integration in type II GGHs which continue to express and secrete surface antigens, representing the sustained surface antigens in the serum after NA antiviral treatment. The persistence of GGHs in the liver after anti-viral therapy not only constitute the challenge to eliminate HBV infection but also carry the high risk to develop HCC. DNA chip and ELISA kit are designing to detect the pre-S mutants in serum. Novel or second generation anti-HBV drugs are under phase II development and include the combination of anti-virals, immunomodulators, agents for host DNA damage, and siRNA to target at the transcription of HBsAg gene in cccDNA or integrated HBV DNA. In the past years, we explored the possibility to provide drugs or natural agents targeting at ER stress signals in GGHs to prevent HCC development. In a transgenic mice model of pre-S mutant and HBx, a combination of silymarin and resveratrol targeting at mTOR and NF-κB signals could reduce a 80% of HCC development. In a pilot clinical trial, liposomal curcumin (Meriva® combined with anti-virals and immumodulators P1101 have been designed and attempted to eliminate the serum surface antigen and hence the recurrence of HCC after surgical resection. Therefore, the detection of pre-S mutants in serum or GGHs in the liver should provide rational target design for therapy or prevention of HCC in these high

  19. The Rosseland mean opacity of interstellar grain

    International Nuclear Information System (INIS)

    Ali, A.; El Shalaby, M.A.; El-Nawawy, M.S.

    1990-10-01

    We have calculated the opacity of interstellar grains in the temperature range 10 deg. K - 1500 deg. K. Two composite grain models have been considered. One of them consists of silicate coated with ice mantle and the second has a graphite core coated also with ice mantle. These models are compared with isolated grain models. An exact analytical and computational development of Guettler's formulae for composite grain models has been used to calculate the extinction coefficient. It has been found that the thickness of the mantle affects the opacity of the interstellar grains. The opacity of composite models differs from that of the isolated models. The effect of the different species (ice, silicate and graphite) is also clear. (author). 22 refs, 4 figs, 1 tab

  20. Performance audit procedures for opacity monitors

    International Nuclear Information System (INIS)

    Plaisance, S.J.; Peeler, J.W.

    1987-04-01

    This manual contains monitor-specific performance audit procedures and data forms for use in conducting audits of installed opacity continuous emission monitoring systems (CEMS). General auditing procedures and acceptance limits for various audit criteria are discussed. Practical considerations and common problems encountered in conducting audits are delineated, and recommendations are included to optimize the successful completion of performance audits. Performance audit procedures and field-data forms were developed for six common opacity CEMS: (1) Lear Siegler, Inc. Model RM-41; (2) Lear Siegler, Inc. Model RM-4; (3) Dynatron Model 1100; (4) Thermo Electron, Inc. Model 400; (5) Thermo Electron, Inc. Model 1000A; and (6) Enviroplan Model D-R280 AV. Generic audit procedures are included for use in evaluating opacity CEMS with multiple transmissometers and combiner devices. In addition, several approaches for evaluating the zero-alignment or clear-path zero response are described. The zero-alignment procedures are included since the factor is fundamental to the accuracy of opacity monitoring data, even though the zero-alignment checks cannot usually be conducted during a performance audit

  1. Time Patterns in Remote OPAC Use.

    Science.gov (United States)

    Lucas, Thomas A.

    1993-01-01

    Describes a transaction log analysis of the New York Public Library research libraries' OPAC (online public access catalog). Much of the remote searching occurred when the libraries were closed and was more evenly distributed than internal searching, demonstrating that remote searching could expand access and reduce peak system loads. (Contains…

  2. Neutrino opacities and the pasta phase structure

    International Nuclear Information System (INIS)

    Menezes, D.P.; Alloy, M.D.

    2011-01-01

    The diffusion coefficients that are related to the neutrino opacities are calculated in such a way that the formation of nuclear pasta and homogeneous matter at low densities are taken into account. Two methods are developed to build the pasta phase and their differences are outlined. One of them is chosen as part of a complete equation of state used in the calculation of the diffusion coefficients. Our results show that the mean free paths are significantly altered by the presence of nuclear pasta in stellar matter when compared with the results obtained with pure homogeneous matter. These differences in neutrino opacities will have consequences in the calculation of the Kelvin-Helmholtz phase of protoneutron stars. (author)

  3. OPAC systému ALEPH

    OpenAIRE

    Pačísková, Jana

    2010-01-01

    This bachelor thesis presents analysis and evaluation of online catalog of integrated library system ALEPH, which was made after studying Web OPAC manual of this system and gathering information from practical testing of catalogs of National Library of Czech Republic and Regional Library of Karlovy Vary. In the first chapter, there is introduced and defined Online Public Access Catalog and its main principles and also its history is presented. In next chapters, there are described features an...

  4. Extended Opacity Tables with Higher Temperature-Density-Frequency Resolution

    Science.gov (United States)

    Schillaci, Mark; Orban, Chris; Delahaye, Franck; Pinsonneault, Marc; Nahar, Sultana; Pradhan, Anil

    2015-05-01

    Theoretical models for plasma opacities underpin our understanding of radiation transport in many different astrophysical objects. These opacity models are also relevant to HEDP experiments such as ignition scale experiments on NIF. We present a significantly expanded set of opacity data from the widely utilized Opacity Project, and make these higher resolution data publicly available through OSU's portal with dropbox.com. This expanded data set is used to assess how accurate the interpolation of opacity data in temperature-density-frequency dimensions must be in order to adequately model the properties of most stellar types. These efforts are the beginning of a larger project to improve the theoretical opacity models in light of experimental results at the Sandia Z-pinch showing that the measured opacity of Iron disagrees strongly with all current models.

  5. SOLAR OPACITY CALCULATIONS USING THE SUPER-TRANSITION-ARRAY METHOD

    International Nuclear Information System (INIS)

    Krief, M.; Feigel, A.; Gazit, D.

    2016-01-01

    A new opacity model has been developed based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of plasmas in local thermodynamic equilibrium. The atomic code, named STAR (STA-Revised), is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried out throughout the solar radiative zone. The relative contributions of different chemical elements and atomic processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge-state distributions are compared with the widely used Opacity Project (OP) code, for several elements near the radiation–convection interface. STAR Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code throughout the radiation zone. Finally, an explicit STA calculation was performed of the full AGSS09 photospheric mixture, including all heavy metals. It was shown that, due to their extremely low abundance, and despite being very good photon absorbers, the heavy elements do not affect the Rosseland opacity

  6. SOLAR OPACITY CALCULATIONS USING THE SUPER-TRANSITION-ARRAY METHOD

    Energy Technology Data Exchange (ETDEWEB)

    Krief, M.; Feigel, A.; Gazit, D., E-mail: menahem.krief@mail.huji.ac.il [The Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel)

    2016-04-10

    A new opacity model has been developed based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of plasmas in local thermodynamic equilibrium. The atomic code, named STAR (STA-Revised), is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried out throughout the solar radiative zone. The relative contributions of different chemical elements and atomic processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge-state distributions are compared with the widely used Opacity Project (OP) code, for several elements near the radiation–convection interface. STAR Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code throughout the radiation zone. Finally, an explicit STA calculation was performed of the full AGSS09 photospheric mixture, including all heavy metals. It was shown that, due to their extremely low abundance, and despite being very good photon absorbers, the heavy elements do not affect the Rosseland opacity.

  7. Radiologic Predictors for Clinical Stage IA Lung Adenocarcinoma with Ground Glass Components: A Multi-Center Study of Long-Term Outcomes.

    Directory of Open Access Journals (Sweden)

    Zhao Li

    Full Text Available This study was to define preoperative predictors from radiologic findings for the pathologic risk groups based on long-term surgical outcomes, in the aim to help guide individualized patient management.We retrospectively reviewed 321 consecutive patients with clinical stage IA lung adenocarcinoma with ground glass component on computed tomography (CT scanning. Pathologic diagnosis for resection specimens was based on the 2011 IASLC/ATS/ERS classification of lung adenocarcinoma. Patients were classified into different pathologic risk grading groups based on their lymph node status, local regional recurrence and overall survival. Radiologic characteristics of the pulmonary nodules were re-evaluated by reconstructed three-dimension CT (3D-CT. Univariate and multivariate analysis identifies independent radiologic predictors from tumor diameter, total volume (TV, average CT value (AVG, and solid-to-tumor (S/T ratio. Receiver operating characteristic curves (ROC studies were carried out to determine the cutoff value(s for the predictor(s. Univariate cox regression model was used to determine the clinical significance of the above findings.A total of 321 patients with clinical stage IA lung adenocarcinoma with ground glass components were included in our study. Patients were classified into two pathologic low- and high- risk groups based on their distinguished surgical outcomes. A total of 134 patients fell into the low-risk group. Univariate and multivariate analyses identified AVG (HR: 32.210, 95% CI: 3.020-79.689, P<0.001 and S/T ratio (HR: 12.212, 95% CI: 5.441-27.408, P<0.001 as independent predictors for pathologic risk grading. ROC curves studies suggested the optimal cut-off values for AVG and S/T ratio were-198 (area under the curve [AUC] 0.921, 2.9 (AUC 0.996 and 54% (AUC 0.907, respectively. The tumor diameter and TV were excluded for the low AUCs (0.778 and 0.767. Both the cutoff values of AVG and S/T ratio were correlated with pathologic

  8. INTERPLAY OF NEUTRINO OPACITIES IN CORE-COLLAPSE SUPERNOVA SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, Eric J. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200 (United States); Mezzacappa, Anthony; Hix, W. Raphael [Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6354 (United States); Messer, O. E. Bronson [National Center for Computational Sciences, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6164 (United States); Bruenn, Stephen W., E-mail: elentz@utk.edu [Department of Physics, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431-0991 (United States)

    2012-11-20

    We have conducted a series of numerical experiments using spherically symmetric, general relativistic, neutrino radiation hydrodynamics with the code Agile-BOLTZTRAN to examine the effects of modern neutrino opacities on the development of supernova simulations. We test the effects of opacities by removing opacities or by undoing opacity improvements for individual opacities and groups of opacities. We find that improvements to electron capture (EC) on nuclei, namely EC on an ensemble of nuclei using modern nuclear structure models rather than the simpler independent-particle approximation (IPA) for EC on a mean nucleus, plays the most important role during core collapse of all tested neutrino opacities. Low-energy neutrinos emitted by modern nuclear EC preferentially escape during collapse without the energy downscattering on electrons required to enhance neutrino escape and deleptonization for the models with IPA nuclear EC. During shock breakout the primary influence on the emergent neutrinos arises from non-isoenergetic scattering (NIS) on electrons. For the accretion phase, NIS on free nucleons and pair emission by e {sup +} e {sup -} annihilation have the largest impact on the neutrino emission and shock evolution. Other opacities evaluated, including nucleon-nucleon bremsstrahlung and especially neutrino-positron scattering, have little measurable impact on neutrino emission or shock dynamics. Modern treatments of nuclear EC, e {sup +} e {sup -}-annihilation pair emission, and NIS on electrons and free nucleons are critical elements of core-collapse simulations of all dimensionality.

  9. IPOPv2 online service for the generation of opacity tables

    International Nuclear Information System (INIS)

    Delahaye, Franck; Zwölf, Carlo Maria; Zeippen, Claude J.; Mendoza, Claudio

    2016-01-01

    In the framework of the present phase – IPOPv2 – of the international Opacity Project (OP), a new web service has been implemented based on the latest release of the OP opacities. The user may construct online opacity tables to be conveniently included in stellar evolution codes in the format most commonly adopted by stellar physicists, namely the OPAL format. This facility encourages the use and comparison of both the OPAL and OP data sets in applications. The present service allows for the calculation of multi-element mixtures containing the 17 species (H, He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and Ni) considered by the OP, and underpins the latest release of OP opacities. This new service provides tables of Rosseland mean opacites using OP atomic data. We provide an alternative to the OPAL opacity services allowing direct comparison as well as study of the effect of uncertainties in stellar modeling due to mean opacities. - Highlights: • A new opacity table service is presented. • This is an alternative to the OPAL service, using The Opacity Project (OP) data. • These tables can directly replace the OPAL data in stellar code without any change in the code.

  10. Dialogue with an OPAC: How Visionary Was Swanson in 1964?

    Science.gov (United States)

    Su, Shiao-Feng

    1994-01-01

    Traces the development of online public access catalogs (OPACs) and compares what has occurred with a 1964 article that outlined recommendations for a future card catalog. Subject access is emphasized, including Library of Congress Subject Headings, expansion of OPACs, user-friendly interfaces, new technologies, and current visions of the future…

  11. An Evaluation of Online Help for the NOTIS OPAC.

    Science.gov (United States)

    White, Frank

    1994-01-01

    Discussion of online help systems in online public access catalogs (OPACs) focuses on a study that evaluated the online help system for the NOTIS (Northwestern Online Total Integrated System) OPAC. Features of the system reviewed include online functions; training features; general interface features; access points; and message content and display…

  12. Calculation of Free-Free Opacities

    Science.gov (United States)

    Bhatia, A. K.; Maiden, D.; Ritchie, A. B., Jr.

    2003-01-01

    Free-free absorption is an important contribution to the opacity for radiation transport through hot materials Temperatures can be as high as several keV, such that it becomes a computational challenge to solve the Schrodinger equation efficiently for rapidly oscillating continuum functions for high angular momenta. Several groups\\footnots, including ours, have studied the phase amplitude solution (PAS) of the Schrodinger equation, in which one solves equations for the wave function amplitude and phase, which are: smooth functions of the electron energy. It is also important to have an accurate Schroudinger benchmark for the development of the PAS method. We present results for dipole matrix elements, Gaunt factors, and cross sections for the absorption of radiation at various energies for Cs XIX at temperature=100 eV and density=0.187 g/cc for our newly developed PAS and Schrodinger benchmark.

  13. An opacity-sampled treatment of water vapor

    Science.gov (United States)

    Alexander, David R.; Augason, Gordon C.; Johnson, Hollis R.

    1989-01-01

    Although the bands of H2O are strong in the spectra of cool stars and calculations have repeatedly demonstrated their significance as opacity sources, only approximate opacities are currently available, due both to the difficulty of accounting for the millions of lines involved and to the inadequacy of laboratory and theoretical data. To overcome these obstacles, a new treatment is presented, based upon a statistical representation of the water vapor spectrum derived from available laboratory data. This statistical spectrum of water vapor employs an exponential distribution of line strengths and random positions of lines whose overall properties are forced to reproduce the mean opacities observed in the laboratory. The resultant data set is then treated by the opacity-sampling method exactly as are all other lines, both molecular and atomic. Significant differences are found between the results of this improved treatment and the results obtained with previous treatments of water-vapor opacity.

  14. High-resolution computed tomography to differentiate chronic diffuse interstitial lung diseases with predominant ground-glass pattern using logical analysis of data

    International Nuclear Information System (INIS)

    Martin, Sophie Grivaud; Brauner, Michel W.; Rety, Frederique; Kronek, Louis-Philippe; Brauner, Nadia; Valeyre, Dominique; Nunes, Hilario; Brillet, Pierre-Yves

    2010-01-01

    We evaluated the performance of high-resolution computed tomography (HRCT) to differentiate chronic diffuse interstitial lung diseases (CDILD) with predominant ground-glass pattern by using logical analysis of data (LAD). A total of 162 patients were classified into seven categories: sarcoidosis (n = 38), connective tissue disease (n = 32), hypersensitivity pneumonitis (n = 18), drug-induced lung disease (n = 15), alveolar proteinosis (n = 12), idiopathic non-specific interstitial pneumonia (n = 10) and miscellaneous (n = 37). First, 40 CT attributes were investigated by the LAD to build up patterns characterising a category. From the association of patterns, LAD determined models specific to each CDILD. Second, data were recomputed by adding eight clinical attributes to the analysis. The 20 x 5 cross-folding method was used for validation. Models could be individualised for sarcoidosis, hypersensitivity pneumonitis, connective tissue disease and alveolar proteinosis. An additional model was individualised for drug-induced lung disease by adding clinical data. No model was demonstrated for idiopathic non-specific interstitial pneumonia and the miscellaneous category. The results showed that HRCT had a good sensitivity (≥64%) and specificity (≥78%) and a high negative predictive value (≥93%) for diseases with a model. Higher sensitivity (≥78%) and specificity (≥89%) were achieved by adding clinical data. The diagnostic performance of HRCT is high and can be increased by adding clinical data. (orig.)

  15. Ground-glass nodule on thin-section CT: Differentiation among adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic predominant invasive adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Man Ho; Ryu, Dae Shick; Kim, Do Young; Ahn, Jae Hong; Choi, Soo Jung; Gang, Gil Hyeon; Yoo, Dong Gon; Shin, Dong Rock [Gangneung Asan Hospital, College of Medicine, University of Ulsan, Gangneung (Korea, Republic of)

    2015-12-15

    To investigate different computed tomography (CT) features among adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and lepidic predominant invasive adenocarcinoma (LPA) that appeared as ground-glass nodules (GGN). We also analyzed different CT findings between Group A (AIS and MIA) and Group B (LPA). We evaluated 19 AIS, 4 MIA, and 9 LPA images that were histologically confirmed and manifested as GGN on thin-section CT scans. CT scans were assessed for lesion characteristics: size, shape, solid portion, internal air density, marginal irregularity and pleural tag. CT findings of Group A and Group B were analyzed using the Kruskal-Wallis test or Fisher's exact test. A significant statistical difference was seen between AIS and LPA for lesion characteristics (p < 0.05). No significant difference was observed between AIS and MIA. Round or polygonal shape with smooth margin was significantly associated with Group A, and complex shape with marginal irregularity was associated with Group B. Group A (AIS and MIA) could be distinguished from Group B (LPA) by smaller lesion size, round or polygonal shape, smaller solid portion and smooth margin.

  16. Ground-glass nodule on thin-section CT: Differentiation among adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic predominant invasive adenocarcinoma

    International Nuclear Information System (INIS)

    Lee, Man Ho; Ryu, Dae Shick; Kim, Do Young; Ahn, Jae Hong; Choi, Soo Jung; Gang, Gil Hyeon; Yoo, Dong Gon; Shin, Dong Rock

    2015-01-01

    To investigate different computed tomography (CT) features among adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and lepidic predominant invasive adenocarcinoma (LPA) that appeared as ground-glass nodules (GGN). We also analyzed different CT findings between Group A (AIS and MIA) and Group B (LPA). We evaluated 19 AIS, 4 MIA, and 9 LPA images that were histologically confirmed and manifested as GGN on thin-section CT scans. CT scans were assessed for lesion characteristics: size, shape, solid portion, internal air density, marginal irregularity and pleural tag. CT findings of Group A and Group B were analyzed using the Kruskal-Wallis test or Fisher's exact test. A significant statistical difference was seen between AIS and LPA for lesion characteristics (p < 0.05). No significant difference was observed between AIS and MIA. Round or polygonal shape with smooth margin was significantly associated with Group A, and complex shape with marginal irregularity was associated with Group B. Group A (AIS and MIA) could be distinguished from Group B (LPA) by smaller lesion size, round or polygonal shape, smaller solid portion and smooth margin

  17. A Comparison of Two Commercial Volumetry Software Programs in the Analysis of Pulmonary Ground-Glass Nodules: Segmentation Capability and Measurement Accuracy

    Science.gov (United States)

    Kim, Hyungjin; Lee, Sang Min; Lee, Hyun-Ju; Goo, Jin Mo

    2013-01-01

    Objective To compare the segmentation capability of the 2 currently available commercial volumetry software programs with specific segmentation algorithms for pulmonary ground-glass nodules (GGNs) and to assess their measurement accuracy. Materials and Methods In this study, 55 patients with 66 GGNs underwent unenhanced low-dose CT. GGN segmentation was performed by using 2 volumetry software programs (LungCARE, Siemens Healthcare; LungVCAR, GE Healthcare). Successful nodule segmentation was assessed visually and morphologic features of GGNs were evaluated to determine factors affecting segmentation by both types of software. In addition, the measurement accuracy of the software programs was investigated by using an anthropomorphic chest phantom containing simulated GGNs. Results The successful nodule segmentation rate was significantly higher in LungCARE (90.9%) than in LungVCAR (72.7%) (p = 0.012). Vascular attachment was a negatively influencing morphologic feature of nodule segmentation for both software programs. As for measurement accuracy, mean relative volume measurement errors in nodules ≥ 10 mm were 14.89% with LungCARE and 19.96% with LungVCAR. The mean relative attenuation measurement errors in nodules ≥ 10 mm were 3.03% with LungCARE and 5.12% with LungVCAR. Conclusion LungCARE shows significantly higher segmentation success rates than LungVCAR. Measurement accuracy of volume and attenuation of GGNs is acceptable in GGNs ≥ 10 mm by both software programs. PMID:23901328

  18. A comparison of two commercial volumetry software programs in the analysis of pulmonary ground-glass nodules: Segmentation capability and measurement accuracy

    International Nuclear Information System (INIS)

    Kim, Hyung Jin; Park, Chang Min; Lee, Sang Min; Lee, Hyun Joo; Goo, Jin Mo

    2013-01-01

    To compare the segmentation capability of the 2 currently available commercial volumetry software programs with specific segmentation algorithms for pulmonary ground-glass nodules (GGNs) and to assess their measurement accuracy. In this study, 55 patients with 66 GGNs underwent unenhanced low-dose CT. GGN segmentation was performed by using 2 volumetry software programs (LungCARE, Siemens Healthcare; LungVCAR, GE Healthcare). Successful nodule segmentation was assessed visually and morphologic features of GGNs were evaluated to determine factors affecting segmentation by both types of software. In addition, the measurement accuracy of the software programs was investigated by using an anthropomorphic chest phantom containing simulated GGNs. The successful nodule segmentation rate was significantly higher in LungCARE (90.9%) than in LungVCAR (72.7%) (p = 0.012). Vascular attachment was a negatively influencing morphologic feature of nodule segmentation for both software programs. As for measurement accuracy, mean relative volume measurement errors in nodules ≥ 10 mm were 14.89% with LungCARE and 19.96% with LungVCAR. The mean relative attenuation measurement errors in nodules ≥ 10 mm were 3.03% with LungCARE and 5.12% with LungVCAR. LungCARE shows significantly higher segmentation success rates than LungVCAR. Measurement accuracy of volume and attenuation of GGNs is acceptable in GGNs ≥ 10 mm by both software programs.

  19. A comparison of two commercial volumetry software programs in the analysis of pulmonary ground-glass nodules: Segmentation capability and measurement accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Jin; Park, Chang Min; Lee, Sang Min; Lee, Hyun Joo; Goo, Jin Mo [Dept. of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul (Korea, Republic of)

    2013-08-15

    To compare the segmentation capability of the 2 currently available commercial volumetry software programs with specific segmentation algorithms for pulmonary ground-glass nodules (GGNs) and to assess their measurement accuracy. In this study, 55 patients with 66 GGNs underwent unenhanced low-dose CT. GGN segmentation was performed by using 2 volumetry software programs (LungCARE, Siemens Healthcare; LungVCAR, GE Healthcare). Successful nodule segmentation was assessed visually and morphologic features of GGNs were evaluated to determine factors affecting segmentation by both types of software. In addition, the measurement accuracy of the software programs was investigated by using an anthropomorphic chest phantom containing simulated GGNs. The successful nodule segmentation rate was significantly higher in LungCARE (90.9%) than in LungVCAR (72.7%) (p = 0.012). Vascular attachment was a negatively influencing morphologic feature of nodule segmentation for both software programs. As for measurement accuracy, mean relative volume measurement errors in nodules ≥ 10 mm were 14.89% with LungCARE and 19.96% with LungVCAR. The mean relative attenuation measurement errors in nodules ≥ 10 mm were 3.03% with LungCARE and 5.12% with LungVCAR. LungCARE shows significantly higher segmentation success rates than LungVCAR. Measurement accuracy of volume and attenuation of GGNs is acceptable in GGNs ≥ 10 mm by both software programs.

  20. Impact of Neutrino Opacities on Core-collapse Supernova Simulations

    Science.gov (United States)

    Kotake, Kei; Takiwaki, Tomoya; Fischer, Tobias; Nakamura, Ko; Martínez-Pinedo, Gabriel

    2018-02-01

    The accurate description of neutrino opacities is central to both the core-collapse supernova (CCSN) phenomenon and the validity of the explosion mechanism itself. In this work, we study in a systematic fashion the role of a variety of well-selected neutrino opacities in CCSN simulations where the multi-energy, three-flavor neutrino transport is solved using the isotropic diffusion source approximation (IDSA) scheme. To verify our code, we first present results from one-dimensional (1D) simulations following the core collapse, bounce, and ∼250 ms postbounce of a 15 {M}ȯ star using a standard set of neutrino opacities by Bruenn. A detailed comparison with published results supports the reliability of our three-flavor IDSA scheme using the standard opacity set. We then investigate in 1D simulations how individual opacity updates lead to differences with the baseline run with the standard opacity set. Through detailed comparisons with previous work, we check the validity of our implementation of each update in a step-by-step manner. Individual neutrino opacities with the largest impact on the overall evolution in 1D simulations are selected for systematic comparisons in our two-dimensional (2D) simulations. Special attention is given to the criterion of explodability in the 2D models. We discuss the implications of these results as well as its limitations and the requirements for future, more elaborate CCSN modeling.

  1. HELIOSEISMIC TESTS OF THE NEW LOS ALAMOS OPACITIES

    Energy Technology Data Exchange (ETDEWEB)

    J. GUZIK; ET AL

    2001-01-01

    We compare the helioseismic properties of two solar models, one calibrated with the OPAL opacities and the other with the recent Los Alamos LEDCOP opacities. We show that, in the radiative interior of the Sun, the small differences between the two sets of opacities (up to 6% near the base of the convection zone) lead to noticeable differences in the solar structure (up to 0.4% in sound speed), with the OPAL model being the closest to the helioseismic data. More than half of the difference between the two opacity sets results from the interpolation scheme and from the relatively widely spaced temperature grids used in the tables. The remaining 3% intrinsic difference between the OPAL and the LEDCOP opacities in the radiative interior of the Sun is well within the error bars on the opacity calculations resulting from the uncertainties on the physics. We conclude that the OPAL and LEDCOP opacity sets do about as well in the radiative interior of the Sun.

  2. The Rosseland Mean Opacity in Dense Plasmas

    Science.gov (United States)

    van Horn, H. M.

    1992-05-01

    In post-main-sequence phases of stellar evolution, densities in the interiors of stars become large enough so that hbar omega_p /kT>1, where omega_p is the electron plasma frequency. The plasma is thus a strongly dispersive medium at frequencies near the peak of the Planck function, and only photons with frequencies omega >omega_p can propagate in the plasma. These effects must be taken into account in computing radiative transfer in stellar interiors. Here I first identify several late evolutionary stages in which these effects may be significant. Then I use the formalism Harris 1965 has developed to treat radiative transfer in a dispersive medium in order to derive the resulting modification of the Rosseland mean opacity kappa_R . The resulting expression is the same as that presented (without a full derivation) by Aharony & Opher 1979, who interpreted the frequency-dependent absorption coefficient kappa_ ω as that in vacuo. However, the absorption coefficient in a plasma scales from that in vacuum according to the relation kappa_ ω=n_ω(-1) kappa_ ω((vac)) (Bekefi 1966, p. 52), where n_ω equiv (kc/omega ) = [1-(omega_p (2/) omega (2)right ](1/2)) is the index of refraction of the plasma. With this correction, we find the Rosseland mean opacity to be given by the expression {1\\over \\kappa_R}={{\\int_{\\omega_p}^{\\infty} {n_{\\omega}^3 \\over \\kappa_{\\omega}^{(vac)}}{partial B_{\\omega} \\over partial T} \\bigg|_{\\omega} d\\omega} \\over{\\int_0^{\\infty}{partial B_{\\omega} \\over partial T} \\bigg|_{\\omega} d\\omega}}. This research has been supported in part by NASA grant NAGW-2444 and in part by NSF grant AST 91-15132. \\centerline{References} Aharony, U., and Opher, R. 1979, A&A, 79, 27. Bekefi, G. 1966, Radiation Processes in Plasmas, (John Wiley & Sons, Inc.: New York). Harris, E. G. 1965, Phys. Rev., 138, B479.

  3. Effective Opacity for Gold-Doped Foam Plasmas

    International Nuclear Information System (INIS)

    Huang Cheng-Wu; Song Tian-Ming; Zhao Yang; Zhu Tuo; Shang Wan-Li; Xiong Gang; Zhang Ji-Yan; Yang Jia-Min; Jiang Shao-En

    2012-01-01

    Radiation flow through gold-doped hydrocarbon foam is investigated and a model is presented to calculate effective opacity for an inhomogeneous, pressure-equilibrated gold/foam mixture based on the Levermore—Pomraning method for binary stochastic media. The effective opacity dependance on the size of the gold particles and the foam temperature are studied. The results suggest that when the mixture temperature is lower than 250 eV, the opacity difference between the 5 μm particle mix case and the atomic mix case is large enough to induce a significant discrepancy in radiation transport, which is confirmed by the hydrodynamic simulation

  4. Computing NLTE Opacities -- Node Level Parallel Calculation

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-11

    Presentation. The goal: to produce a robust library capable of computing reasonably accurate opacities inline with the assumption of LTE relaxed (non-LTE). Near term: demonstrate acceleration of non-LTE opacity computation. Far term (if funded): connect to application codes with in-line capability and compute opacities. Study science problems. Use efficient algorithms that expose many levels of parallelism and utilize good memory access patterns for use on advanced architectures. Portability to multiple types of hardware including multicore processors, manycore processors such as KNL, GPUs, etc. Easily coupled to radiation hydrodynamics and thermal radiative transfer codes.

  5. Research on Spectroscopy, Opacity, and Atmospheres

    Science.gov (United States)

    Kurucz, Robert L.

    2005-01-01

    I propose to continue providing observers with basic data for interpreting spectra from stars, novas, supernovas, clusters, and galaxies. These data will include allowed and forbidden line lists, both laboratory and computed, for the first five to ten ions of all atoms and for all relevant diatomic molecules. I will eventually expand to all ions of the first thirty elements to treat far UV and X-ray spectra, and for envelope opacities. I also include triatomic molecules provided by other researchers. I have also made CDs with Partridge and Schwenke's water data for work on UV stars. The line data also serve as input to my model atmosphere and synthesis programs that generate energy distributions, photometry, limb darkening, and spectra that can be used for planning observations and for fitting observed spectra. The spectrum synthesis programs produce detailed plots with the lines identified. Grids of stellar spectra can be used for radial velocity-, rotation-, or abundance templates and for population synthesis. I am fitting spectra of bright stars to test the data and to produce atlases to guide observers. For each star the whole spectrum is computed from the UV to the far IR. The line data, opacities, models, spectra, and programs are freely distributed on CDs and on my Web site and represent a unique resource for many NASA programs. I am now in full production of new line lists for atoms. I am computing all ions of all elements from H to Zn and the first 5 ions of all the heavier elements, about 800 ions. For each ion I treat as many as 61 even and 61 odd configurations, computing all energy levels and eigenvectors. The Hamiltonian is determined from a scaled-Hartree-Fock starting guess by least squares fitting the observed energy levels. The average energy of each configuration is used in computing scaled-Thomas-Fermi-Dirac wavefunctions for each configuration which in turn are used to compute allowed and forbidden transition integrals. These are multiplied

  6. Exome Array Analysis of Nuclear Lens Opacity.

    Science.gov (United States)

    Loomis, Stephanie J; Klein, Alison P; Lee, Kristine E; Chen, Fei; Bomotti, Samantha; Truitt, Barbara; Iyengar, Sudha K; Klein, Ronald; Klein, Barbara E K; Duggal, Priya

    2018-06-01

    Nuclear cataract is the most common subtype of age-related cataract, the leading cause of blindness worldwide. It results from advanced nuclear sclerosis, or opacity in the center of the optic lens, and is affected by both genetic and environmental risk factors, including smoking. We sought to understand the genetic factors associated with nuclear sclerosis through interrogation of rare and low frequency coding variants using exome array data. We analyzed Illumina Human Exome Array data for 1,488 participants of European ancestry in the Beaver Dam Eye Study who were without cataract surgery for association with nuclear sclerosis grade, controlling for age and sex. We performed single-variant regression analysis for 32,138 variants with minor allele frequency (MAF) ≥0.003. In addition, gene-based analysis of 11,844 genes containing at least two variants with MAF nuclear sclerosis, the possible association with the RNF149 gene highlights a potential candidate gene for future studies that aim to understand the genetic architecture of nuclear sclerosis.

  7. Comparative pulsation calculations with OP and OPAL opacities

    Science.gov (United States)

    Kanbur, Shashi M.; Simon, Norman R.

    1994-01-01

    Comparative linear nonadiabatic pulsation calculations are presented using the OPAL and Opacity Project opacities. The two sets of opacities include effects due to intermediate coupling and fine structure as well as new abundances. We used two mass luminosity (M-L) relations, one standard (BIT), and one employing substantial convective core overshoot (COV). The two sets of opacities cannot be differentiated on the basis of the stellar pulsation calculations presented here. The BIT relation can model the beat and bump Cepheids with masses between 4 and 7 solar mass, while if the overshoot relation is used, masses between 2 and 6 solar mass are required. In the RR Lyrae regime, we find the inferred masses of globular cluster RRd stars to be little influenced by the choice of OPAL or OP. Finally, the limited modeling we have done is not able to constrain the Cepheid M-L relation based upon period ratios observed in the beat and bump stars.

  8. Opacity calculations for extreme physical systems: code RACHEL

    Science.gov (United States)

    Drska, Ladislav; Sinor, Milan

    1996-08-01

    Computer simulations of physical systems under extreme conditions (high density, temperature, etc.) require the availability of extensive sets of atomic data. This paper presents basic information on a self-consistent approach to calculations of radiative opacity, one of the key characteristics of such systems. After a short explanation of general concepts of the atomic physics of extreme systems, the structure of the opacity code RACHEL is discussed and some of its applications are presented.

  9. Nuclear 'pasta phase' and its consequences on neutrino opacities

    International Nuclear Information System (INIS)

    Alloy, M. D.; Menezes, D. P.

    2011-01-01

    In this paper, we calculate the diffusion coefficients that are related to the neutrino opacities considering the formation of nuclear pasta and homogeneous matter at low densities. Our results show that the mean-free paths are significantly altered by the presence of nuclear pasta in stellar matter when compared with the results obtained with homogeneous matter. These differences in neutrino opacities certainly influence the Kelvin-Helmholtz phase of protoneutron stars and consequently the results of supernova explosion simulations.

  10. Solar opacities constrained by solar neutrinos and solar oscillations

    International Nuclear Information System (INIS)

    Cox, A.N.

    1989-01-01

    This review discusses the current situation for opacities at the solar center, the solar surface, and for the few million kelvin temperatures that occur below the convection zone. The solar center conditions are important because they are crucial for the neutrino production, which continues to be predicted about 4 times that observed. The main extinction effects there are free-free photon absorption in the electric fields of the hydrogen, helium and the CNO atoms, free electron scattering of photons, and the bound-free and bound-bound absorption of photons by iron atoms with two electrons in the 1s bound level. An assumption that the iron is condensed-out below the convection zone, and the opacity in the central regions is thereby reduced, results in about a 25 percent reduction in the central opacity but only a 5 percent reduction at the base of the convection zone. Furthermore, the p-mode solar oscillations are changed with this assumption, and do not fit the observed ones as well as for standard models. A discussion of the large effective opacity reduction by weakly interacting massive particles also results in poor agreement with observed p-mode oscillation frequencies. The much larger opacities for the solar surface layers from the Los Alamos Astrophysical Opacity Library instead of the widely used Cox and Tabor values show small improvements in oscillation frequency predictions, but the largest effect is in the discussion of p-mode stability. Solar oscillation frequencies can serve as an opacity experiment for the temperatures and densities, respectively, of a few million kelvin and between 0.1 and 10 g/cm 3 . Current oscillation frequency calculations indicate that possibly the Opacity Library values need an increase of typically 15 percent just at the bottom of the convection zone at 3 x 10 6 K. 41 refs., 15 figs., 1 tab

  11. Investigating the Effect of Cosmic Opacity on Standard Candles

    International Nuclear Information System (INIS)

    Hu, J.; Yu, H.; Wang, F. Y.

    2017-01-01

    Standard candles can probe the evolution of dark energy over a large redshift range. But the cosmic opacity can degrade the quality of standard candles. In this paper, we use the latest observations, including Type Ia supernovae (SNe Ia) from the “joint light-curve analysis” sample and Hubble parameters, to probe the opacity of the universe. A joint fitting of the SNe Ia light-curve parameters, cosmological parameters, and opacity is used in order to avoid the cosmological dependence of SNe Ia luminosity distances. The latest gamma-ray bursts are used in order to explore the cosmic opacity at high redshifts. The cosmic reionization process is considered at high redshifts. We find that the sample supports an almost transparent universe for flat ΛCDM and XCDM models. Meanwhile, free electrons deplete photons from standard candles through (inverse) Compton scattering, which is known as an important component of opacity. This Compton dimming may play an important role in future supernova surveys. From analysis, we find that about a few per cent of the cosmic opacity is caused by Compton dimming in the two models, which can be corrected.

  12. Model-independent Constraints on Cosmic Curvature and Opacity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guo-Jian; Li, Zheng-Xiang; Xia, Jun-Qing; Zhu, Zong-Hong [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Wei, Jun-Jie, E-mail: gjwang@mail.bnu.edu.cn, E-mail: zxli918@bnu.edu.cn, E-mail: xiajq@bnu.edu.cn, E-mail: zhuzh@bnu.edu.cn, E-mail: jjwei@pmo.ac.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2017-09-20

    In this paper, we propose to estimate the spatial curvature of the universe and the cosmic opacity in a model-independent way with expansion rate measurements, H ( z ), and type Ia supernova (SNe Ia). On the one hand, using a nonparametric smoothing method Gaussian process, we reconstruct a function H ( z ) from opacity-free expansion rate measurements. Then, we integrate the H ( z ) to obtain distance modulus μ {sub H}, which is dependent on the cosmic curvature. On the other hand, distances of SNe Ia can be determined by their photometric observations and thus are opacity-dependent. In our analysis, by confronting distance moduli μ {sub H} with those obtained from SNe Ia, we achieve estimations for both the spatial curvature and the cosmic opacity without any assumptions for the cosmological model. Here, it should be noted that light curve fitting parameters, accounting for the distance estimation of SNe Ia, are determined in a global fit together with the cosmic opacity and spatial curvature to get rid of the dependence of these parameters on cosmology. In addition, we also investigate whether the inclusion of different priors for the present expansion rate ( H {sub 0}: global estimation, 67.74 ± 0.46 km s{sup −1} Mpc{sup −1}, and local measurement, 73.24 ± 1.74 km s{sup −1} Mpc{sup −1}) exert influence on the reconstructed H ( z ) and the following estimations of the spatial curvature and cosmic opacity. Results show that, in general, a spatially flat and transparent universe is preferred by the observations. Moreover, it is suggested that priors for H {sub 0} matter a lot. Finally, we find that there is a strong degeneracy between the curvature and the opacity.

  13. Experiment to measure oxygen opacity at high density and temperature

    Science.gov (United States)

    Keiter, Paul; Butler, Hannah; Trantham, Matt; Mussack, Katie; Colgan, James; Fontes, Chris; Guzik, Joyce; Kilcrease, David; Perry, Ted; Orban, Chris; Ducret, Jean-Eric; La Pennec, Maelle; Turck-Chieze, Sylvaine; Mancini, Roberto; Heeter, Robert

    2017-10-01

    In recent years, there has been a debate over the abundances of heavy elements (Z >2) in the solar interior. Recent solar atmosphere models [Asplund 2009] find a significantly lower abundance for C, N, and O compared to models used roughly a decade ago. Recent opacity measurements of iron disagree with opacity model predictions [Bailey et al., 2015]. Repeated scrutiny of the experiment and data has not produced a conclusive reason for the discrepancy. New models have been implemented in the ATOMIC opacity code for low-Z elements [Colgan, 2013, Armstrong 2014], however no data currently exists to test the low-Z material models in the regime relevant to the solar convection zone. We present an experimental design using the opacity platform developed at the National Ignition Facility to study the oxygen opacity at densities and temperatures near the solar convection zone conditions. This work is funded by the U.S. DOE, through the NNSA-DS and SC-OFES Joint Program in HEDLP, Grant Number DE-NA0002956, and the NLUF Program, Grant Number DE-NA0002719, and through the LLE, University of Rochester by the NNSA/OICF under No. DE-NA0001944.

  14. Verification of Opacity and Diagnosability for Pushdown Systems

    Directory of Open Access Journals (Sweden)

    Koichi Kobayashi

    2013-01-01

    Full Text Available In control theory of discrete event systems (DESs, one of the challenging topics is the extension of theory of finite-state DESs to that of infinite-state DESs. In this paper, we discuss verification of opacity and diagnosability for infinite-state DESs modeled by pushdown automata (called here pushdown systems. First, we discuss opacity of pushdown systems and prove that opacity of pushdown systems is in general undecidable. In addition, a decidable class is clarified. Next, in diagnosability, we prove that under a certain assumption, which is different from the assumption in the existing result, diagnosability of pushdown systems is decidable. Furthermore, a necessary condition and a sufficient condition using finite-state approximations are derived. Finally, as one of the applications, we consider data integration using XML (Extensible Markup Language. The obtained result is useful for developing control theory of infinite-state DESs.

  15. Opacity of expanding media: The effect of spectral lines

    International Nuclear Information System (INIS)

    Karp, A.H.; Lasher, G.; Chan, K.L.; Salpeter, E.E.

    1977-01-01

    Spectral lines are more effective in slowing the transport of radiation in expanding (or contracting) objects than in static ones. The velocity gradient associated with the expansion causes the frequency of the photons to be continuously redshifted relative to the rest frame of the gas through which they travel. Those photons which are redshifted to the frequency of a sufficiently strong line will be absorbed by the corresponding bound-bound transition, and the net effect will be to increase the effective opacity of the gas. In certain cases the effect can be taken into account by using an effective opacity, the expansion opacity, which is a function not only of the temperature and density but also of the velocity gradient.Practical formulae for computing the expansion opacity and its Rosseland mean in terms of sums over spectral lines are derived. It is shown that the cumulative effect of many weak lines can be important, implying that a large list of spectral lines is required to obtain results of even modest accuracy. Numerical computations using the 260,000-entry line list of Kurucz and Peytremann have been completed and some samples of the result are given. The general effect may be important in many astronomical objects, but only in some of these will be detailed approach of this paper be appropriate. In optically thick supernova shells, the effect is important both in maintaining the radiation in thermal equilibrium as it diffuses out of the shell and in increasing the value of the total opacity. The enhancement of the opacity ranges from less than 1% to more than an order of magnitude, depending on the temperature, density, and velocity gradient

  16. Measuring the opacity of stellar interior matter in terrestrial laboratories

    Science.gov (United States)

    Bailey, James

    2015-11-01

    How does energy propagate from the core to the surface of the Sun, where it emerges to warm the Earth? Nearly a century ago Eddington recognized that the attenuation of radiation by stellar matter controls the internal structure of stars like the sun. Opacities for high energy density (HED) matter are challenging to calculate because accurate and complete descriptions of the energy levels, populations, and plasma effects such as continuum lowering and line broadening are needed for partially ionized atoms. This requires approximations, in part because billions of bound-bound and bound-free electronic transitions can contribute to the opacity. Opacity calculations, however, have never been benchmarked against laboratory measurements at stellar interior conditions. Laboratory opacity measurements were limited in the past by the challenges of creating and diagnosing sufficiently large and uniform samples at the extreme conditions found inside stars. In research conducted over more than 10 years, we developed an experimental platform on the Z facility and measured wavelength-resolved iron opacity at electron temperatures Te = 156-195 eV and densities ne = 0.7-4.0 x 1022 cm-3 - conditions very similar to the radiation/convection boundary zone within the Sun. The wavelength-dependent opacity in the 975-1775 eV photon energy range is 30-400% higher than models predict. This raises questions about how well we understand the behavior of atoms in HED plasma. These measurements may also help resolve decade-old discrepancies between solar model predictions and helioseismic observations. This talk will provide an overview of the measurements, investigations of possible errors, and ongoing experiments aimed at testing hypotheses to resolve the model-data discrepancy. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

  17. Ultra-dense hot low Z line transition opacity simulations

    International Nuclear Information System (INIS)

    Sauvan, P.; Minguez, E.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Martel, P.; Angelo, P.; Schott, R.; Philippe, F.; Leboucher-Dalimier, E.; Mancini, R.; Calisti, A.

    2002-01-01

    In this work two atomic physics models (the IDEFIX code using the dicenter model and the code based on parametric potentials ANALOP) have been used to calculate the opacities for bound-bound transitions in hot ultra-dense, low Z plasmas. These simulations are in connection with experiments carried out at LULI during the last two years, focused on bound-bound radiation. In this paper H-like opacities for aluminum and fluorine plasmas have been simulated, using both theoretical models, in a wide range of densities and temperatures higher than 200 eV

  18. SOLAR MIXTURE OPACITY CALCULATIONS USING DETAILED CONFIGURATION AND LEVEL ACCOUNTING TREATMENTS

    International Nuclear Information System (INIS)

    Blancard, Christophe; Cossé, Philippe; Faussurier, Gérald

    2012-01-01

    An opacity model (OPAS) combining detailed configuration and level accounting treatments has been developed to calculate radiative opacity of plasmas in local thermodynamic equilibrium. The model is presented and used to compute spectral opacities of a solar mixture. Various density-temperature couples have been considered from the solar center up to the vicinity of the radiative/convective zone interface. For a given solar thermodynamic path, OPAS calculations are compared to Opacity Project (OP) and OPAL data. Rosseland mean opacity values are in very good agreement over all the considered solar thermodynamic path, while OPAS and OP spectral opacities of each element may vary considerably. Main sources of discrepancy are discussed.

  19. FIRST NEW SOLAR MODELS WITH OPAS OPACITY TABLES

    Energy Technology Data Exchange (ETDEWEB)

    Le Pennec, M.; Turck-Chièze, S.; Salmon, S. [CEA/IRFU/Service d’Astrophysique, CE Saclay, F-91191 Gif sur Yvette (France); Blancard, C.; Cossé, P.; Faussurier, G.; Mondet, G. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2015-11-10

    Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However, the particular case of the Sun is still challenging. For about a decade now, the helioseismic sound-speed determination has continued to disagree with the standard solar model (SSM) prediction, questioning the reliability of this model. One of the sources of uncertainty could be in the treatment of the transport of radiation from the solar core to the surface. In this Letter, we use the new OPAS opacity tables, recently available for solar modeling, to address this issue. We discuss first the peculiarities of these tables, then we quantify their impact on the solar sound-speed and density profiles using the reduced OPAS tables taken on the grids of the OPAL ones. We use the two evolution codes, Modules for Experiments in Stellar Astrophysics and Code Liégeois d’Evolution Stellaire, that led to similar conclusions in the solar radiative zone. In comparison to commonly used OPAL opacity tables, the new solar models are computed for the most recent photospheric composition with OPAS tables and present improvements to the location of the base of the convective zone and to the description of the solar radiative zone in comparison to the helioseismic observations, even if the differences in the Rosseland mean opacity do not exceed 6%. We finally carry out a comparison to a solar model computed with the OP opacity tables.

  20. Los Alamos Opacities: Transition from LEDCOP to ATOMIC

    International Nuclear Information System (INIS)

    Magee, N.H.; Abdallah, J.; Colgan, J.; Hakel, P.; Kilcrease, D.P.; Mazevet, S.; Sherrill, M.; Fontes, C.J.; Zhang, H.L.

    2004-01-01

    This paper discusses the development of the ATOMIC code, a new low to mid Z opacity code, which will replace the current Los Alamos low Z opacity code LEDCOP. The ATOMIC code is based on the FINE code, long used by the Los Alamos group for spectral comparisons in local thermodynamic equilibrium (LTE) and for non-LTE calculations, utilizing the extensive databases from the atomic physics suite of codes based on the work of R. D. Cowan. Many of the plasma physics packages in LEDCOP, such as line broadening and free-free absorption, are being transferred to the new ATOMIC code. A new equation of state (EOS) model is being developed to allow higher density calculations than were possible with either the FINE or LEDCOP codes. Extensive modernization for both ATOMIC and the atomic physics code suites, including conversion to Fortran 90 and parallelization, are under way to speed up the calculations and to allow the use of expanded databases for both the LTE opacity tables and the non-LTE calculations. Future plans will be outlined, including considerations for new generation opacity tables

  1. Designing the OPAC User Interface to Improve Access and Retrieval.

    Science.gov (United States)

    Basista, Thomas; And Others

    1991-01-01

    Discussion of problems with retrieval of records in library online public access catalogs (OPACs) focuses on an ongoing research project at the Indiana University of Pennsylvania (IUP) that has been trying to improve subject retrieval vocabulary control using natural and thesaural language and on the design of a good graphical user interface.…

  2. Assessment of subpleural opacities on high-resolution CT

    International Nuclear Information System (INIS)

    Choi, Hee Seok; Kim, Jeung Sook; Kang, Eun Young; Kim, Hak Hee

    2007-01-01

    The purpose of this study was to assess the value of HRCT for determining the cause of subpleural opacities. We evaluated 49 cases of subpleural opacities on HRCT scan, among with the patients with subpleural opacities seen on the conventional chest radiographs. Two 'blinded' reviewers retrospectively analyzed the CT scans by working in consensus. The patients consisted of COP (n = 14), NSIP (n = 13), UIP (n = 10), fibrosis associated with connective tissue disease or drug toxicity (n = 4), CEP (n = 4), Churg-Strauss syndrome (n = 2), DIP (n = 1) and AIP (n = 1). The predominant findings were consolidation (57%) with a peribronchovascular distribution (57%) in the COP patients, GGO (69%) and the associated focal reticular densities (61%) in the NSIP patients, and reticular or reticulonodular densities with a paucity of GGO in the UIP patients (100%). For the diagnosis of COP, NSIP and UIP, the use of HRCT demonstrated a high sensitivity (86%, 85% and 90%, respectively), specificity (97%, 86% and 95%) and accuracy (94%, 86% and 94%). Although an overlap of CT findings is seen for diseases showing subpleural opacities, consolidation with a subpleural and peribronchovascular distribution is highly suggestive for COP, subpleural GGO is highly suggestive of NSIP, subpleural reticular or reticulonodular densities with a paucity of GGO is highly suggestive of UIP and subpleural consolidation accompanied by reticular densities is suggestive of fibrosis

  3. Assessment of subpleural opacities on high-resolution CT

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hee Seok; Kim, Jeung Sook [Dngguk University International Hospital, Goyang (Korea, Republic of); Kang, Eun Young [Korea University Guro Hospital, Seoul (Korea, Republic of); Kim, Hak Hee [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2007-11-15

    The purpose of this study was to assess the value of HRCT for determining the cause of subpleural opacities. We evaluated 49 cases of subpleural opacities on HRCT scan, among with the patients with subpleural opacities seen on the conventional chest radiographs. Two 'blinded' reviewers retrospectively analyzed the CT scans by working in consensus. The patients consisted of COP (n = 14), NSIP (n = 13), UIP (n = 10), fibrosis associated with connective tissue disease or drug toxicity (n = 4), CEP (n = 4), Churg-Strauss syndrome (n = 2), DIP (n = 1) and AIP (n = 1). The predominant findings were consolidation (57%) with a peribronchovascular distribution (57%) in the COP patients, GGO (69%) and the associated focal reticular densities (61%) in the NSIP patients, and reticular or reticulonodular densities with a paucity of GGO in the UIP patients (100%). For the diagnosis of COP, NSIP and UIP, the use of HRCT demonstrated a high sensitivity (86%, 85% and 90%, respectively), specificity (97%, 86% and 95%) and accuracy (94%, 86% and 94%). Although an overlap of CT findings is seen for diseases showing subpleural opacities, consolidation with a subpleural and peribronchovascular distribution is highly suggestive for COP, subpleural GGO is highly suggestive of NSIP, subpleural reticular or reticulonodular densities with a paucity of GGO is highly suggestive of UIP and subpleural consolidation accompanied by reticular densities is suggestive of fibrosis.

  4. Multimedia Visualizer: An Animated, Object-Based OPAC.

    Science.gov (United States)

    Lee, Newton S.

    1991-01-01

    Describes the Multimedia Visualizer, an online public access catalog (OPAC) that uses animated visualizations to make it more user friendly. Pictures of the system are shown that illustrate the interactive objects that patrons can access, including card catalog drawers, librarian desks, and bookshelves; and access to multimedia items is described.…

  5. Library OPACs on the Web: Finding and Describing Directories.

    Science.gov (United States)

    Henry, Marcia

    1997-01-01

    Provides current descriptions of some of the major directories that link to library catalogs on the World Wide Web. Highlights include LibWeb; Hytelnet; WebCats; WWW Library Directory; and techniques for finding new library OPAC (online public access catalog) directories. (LRW)

  6. Web-based OPACs: Between Tradition and Innovation.

    Science.gov (United States)

    Moscoso, Purificacion; Ortiz-Repiso, Virginia

    1999-01-01

    Analyzes the change that Internet-based OPACs (Online Public Access Catalogs) have represented to the structure, administration, and maintenance of the catalogs, retrieval systems, and user interfaces. Examines the structure of databases and traditional principles that have governed systems development. Discusses repercussions of the application…

  7. Terrien's marginal degeneration accompanied by latticed stromal opacities.

    Science.gov (United States)

    Zhang, Yibing; Jia, Hui

    2014-05-01

    We report a case of Terrien's marginal degeneration (TMD) with a unilaterally typical narrow band of peripheral corneal stroma thinning, accompanied by the presence of an unusual network of opacities diffusing throughout the anterior stroma layers. A 43-year-old woman presented with superior nasal peripheral corneal thinning and an unusual network of polygonal stromal opacities in the anterior corneal stroma of the right eye. Latticed corneal changes were unusually extensive and distributed diffusely in the stroma. No abnormalities were found in the corneal epithelium and in the basal epithelial cells. No noticeable changes were found in the left eye. Because of a progressively worse ocular irritation of the right eye, a diagnosis of TMD was made for this patient. This case of TMD accompanied by keratopathy was unusual. The branching stromal lattice pattern of the corneal opacities was difficult to distinguish from lattice corneal dystrophy. In this case, the polygonal stromal opacities were located in the anterior corneal stroma and therefore were distinguished from a similar manifestation in posterior crocodile shagreen.

  8. Terrien’s Marginal Degeneration Accompanied by Latticed Stromal Opacities

    Science.gov (United States)

    Zhang, Yibing; Jia, Hui

    2014-01-01

    ABSTRACT Purpose We report a case of Terrien’s marginal degeneration (TMD) with a unilaterally typical narrow band of peripheral corneal stroma thinning, accompanied by the presence of an unusual network of opacities diffusing throughout the anterior stroma layers. Case Report A 43-year-old woman presented with superior nasal peripheral corneal thinning and an unusual network of polygonal stromal opacities in the anterior corneal stroma of the right eye. Latticed corneal changes were unusually extensive and distributed diffusely in the stroma. No abnormalities were found in the corneal epithelium and in the basal epithelial cells. No noticeable changes were found in the left eye. Because of a progressively worse ocular irritation of the right eye, a diagnosis of TMD was made for this patient. Conclusions This case of TMD accompanied by keratopathy was unusual. The branching stromal lattice pattern of the corneal opacities was difficult to distinguish from lattice corneal dystrophy. In this case, the polygonal stromal opacities were located in the anterior corneal stroma and therefore were distinguished from a similar manifestation in posterior crocodile shagreen. PMID:24681833

  9. An Alternative to EPA Method 9 -- Field Validation of the Digital Opacity Compliance System (DOCS)

    National Research Council Canada - National Science Library

    Rasmussen, Steve L; Stone, Daniel A

    2005-01-01

    The Digital Opacity Compliance System (DOCS) software translates images from a commercial digital camera into visual plume opacity measurements, and is proposed as an alternate reporting method to EPA Method 9...

  10. Glass sealing

    Energy Technology Data Exchange (ETDEWEB)

    Brow, R.K.; Kovacic, L.; Chambers, R.S. [Sandia National Labs., Albuquerque, NM (United States)

    1996-04-01

    Hernetic glass sealing technologies developed for weapons component applications can be utilized for the design and manufacture of fuel cells. Design and processing of of a seal are optimized through an integrated approach based on glass composition research, finite element analysis, and sealing process definition. Glass sealing procedures are selected to accommodate the limits imposed by glass composition and predicted calculations.

  11. Electrochromic Glasses.

    Science.gov (United States)

    1980-07-31

    this glass and that dipole-dipole correlations contribute to the "ferroelectric-like" character of this amorphous system. The TeO2 -W03 glasses can only...shows the dielectric constant and Fig. I(b) glass from pure TeO2 ot pure WO. In addition, glass the tan 8 of the WO glass as a function of temperature... glasses containing WO, in various glass forming nitworks of LifO-B1O0, Na:O-BzO,, and TeO2 were prepared from reagent grade oxides at 800 C - 9SO C in

  12. Grinding Glass Disks On A Belt Sander

    Science.gov (United States)

    Lyons, James J., III

    1995-01-01

    Small machine attached to table-top belt sander makes possible to use belt sander to grind glass disk quickly to specified diameter within tolerance of about plus or minus 0.002 in. Intended to be used in place of production-shop glass grinder. Held on driveshaft by vacuum, glass disk rotated while periphery ground by continuous sanding belt.

  13. Models for the computation of opacity of mixtures

    International Nuclear Information System (INIS)

    Klapisch, Marcel; Busquet, Michel

    2013-01-01

    We compare four models for the partial densities of the components of mixtures. These models yield different opacities as shown on polystyrene, acrylic and polyimide in local thermodynamical equilibrium (LTE). Two of these models, the ‘whole volume partial pressure’ model (M1) and its modification (M2) are not thermodynamically consistent (TC). The other two models are TC and minimize free energy. M3, the ‘partial volume equal pressure’ model, uses equality of chemical potential. M4 uses commonality of free electron density. The latter two give essentially identical results in LTE, but M4’s convergence is slower. M4 is easily generalized to non-LTE conditions. Non-LTE effects are shown by the variation of the Planck mean opacity of the mixtures with temperature and density. (paper)

  14. [Glycosaminoglycans in subepithelial opacity after excimer laser keratectomy].

    Science.gov (United States)

    Nakayasu, K; Gotoh, T; Ishikawa, T; Kanai, A

    1996-05-01

    We evaluated histochemically the characteristics of glycosaminoglycans and proteoglycans in the corneal subepithelial opacity after excimer laser keratectomy on rabbit corneas. We also performed the same evaluations on the cornea after mechanical keratectomy. Twenty days after the operations, the area immediately subjacent to the epithelium showed strong staining with toluidine blue, alcian blue, and colloidal iron. However, after treatment with chondroitinase ABC or chondroitinase AC, alcian blue staining in this area decreased dramatically. Antilarge proteoglycan antibody also reacted strongly in this area. Histochemical and immunohistochemical examination of the cornea where mechanical keratectomy was done showed basically similar findings with the cornea of excimer laser keratectomy. These results suggest that large-molecula proteoglycans with chondroitine sulfate side chains become localized in the subepithelial area after two different kinds of keratectomies. We presume from histochemical and immunohistochemical observations that the subepithelial opacity observed after excimer laser keratectomy is not a special reaction to excimer laser but simply a corneal scar formed after stromal resection.

  15. Nuclear opacity for neutrinos at small Q2

    International Nuclear Information System (INIS)

    Kopeliovich, B.Z.

    1989-01-01

    The causes of nuclear screening of the vector and the weak axial currents are quite different. The hadronic fluctuations of neutrino in the nuclear matter live much longer than in the vacuum, due to interaction with nucleons. Nuclear opacity for neutrinos calculated using Glauber-Gribov theory, differs considerably from that given by the Bell optical model. A good agreement of the theory with the recent BEBC WA59 Collaboration measurements is found. 14 refs.; 4 figs

  16. Studies of the experimental technologies of radiative opacity

    International Nuclear Information System (INIS)

    Zhang Jiyan; Yang Guohong; Ding Yaonan; Yang Jiamin; Li Jun; Zhang Wenhai; He Yingling; Wang Yaomei; Huang Haodong

    2004-12-01

    On the SHENGUANG-II laser facility, integrated experiment for opacity measurement was performed and related physical items were studies. In the experiment, some new-typed diagnosing device were also tested. The experiment includes three contents: (1) Investigation of the measurement technique of absorption spectra in the keV region; (2) Investigation of the measurement technique of dual point projection spectroscopy; (3) Investigation of the temperature and density parameters of the experimental samples. (authors)

  17. Lightweight, high-opacity Bible paper by fiber loading

    Science.gov (United States)

    Klaus Doelle; Oliver Heise; John H. Klungness; Said M. AbuBakr

    2000-01-01

    This paper has been prepared in order to discuss Fiber Loading™ for lightweight, high-opacity bible paper. Incorporating fillers within pulp fibers has been subject to research since 1960 (Green et al. 1962, Scallan et al. 1985, Allen et al. 1992). Fiber Loading™ is a method for manufacturing precipitated calcium carbonate (PCC) directly within the pulp processing...

  18. Analysis of irregular opacities of silicosis using computed tomography

    International Nuclear Information System (INIS)

    Maeda, Atsushi; Shida, Hisao; Chiyotani, Keizo; Saito, Kenichi; Mishina, Michihito

    1983-01-01

    Classification in used to codify Chest CT images of abnormalities of the lung in a simple reproducible manner. Simbols to record CT features of importance are listed. We applied CT to 92 cases of silicosis and roentgenological analysis was performed. Bullae, honeycombing, cavity, emphysema, pleural thickning and calcification were more clearly demonstrated in CT images than routine chest roentgenograms. Irregular opacities were considered to be a combined profusion of small round and streak or strand. (author)

  19. IRAS associations with dark clouds of opacity class 6

    International Nuclear Information System (INIS)

    Parker, N.D.

    1988-01-01

    Accurate positions of the opacity class 6 clouds from the Lynds Catalog of Dark Nebulae have been measured on blue and red prints from the Polomar Observatory Sky Survey (POSS) plates. These revised positions and the dimensions of ellipses fitted to the clouds are listed. The IRAS point source catalog has been searched for sources lying within the boundaries of the 147 clouds in the sample. The distribution and properties of these IRAS sources are discussed briefly. (author)

  20. Controlled opacity in a class of nonlinear dielectric media

    Science.gov (United States)

    Bittencourt, E.; Camargo, G. H. S.; De Lorenci, V. A.; Klippert, R.

    2017-03-01

    Motivated by new technologies for designing and tailoring metamaterials, we seek properties for certain classes of nonlinear optical materials that allow room for a reversibly controlled opacity-to-transparency phase transition through the application of external electromagnetic fields. We examine some mathematically simple models for the dielectric parameters of the medium and compute the relevant geometric quantities that describe the speed and polarization of light rays.

  1. Hohlraum modeling for opacity experiments on the National Ignition Facility

    Science.gov (United States)

    Dodd, E. S.; DeVolder, B. G.; Martin, M. E.; Krasheninnikova, N. S.; Tregillis, I. L.; Perry, T. S.; Heeter, R. F.; Opachich, Y. P.; Moore, A. S.; Kline, J. L.; Johns, H. M.; Liedahl, D. A.; Cardenas, T.; Olson, R. E.; Wilde, B. H.; Urbatsch, T. J.

    2018-06-01

    This paper discusses the modeling of experiments that measure iron opacity in local thermodynamic equilibrium (LTE) using laser-driven hohlraums at the National Ignition Facility (NIF). A previous set of experiments fielded at Sandia's Z facility [Bailey et al., Nature 517, 56 (2015)] have shown up to factors of two discrepancies between the theory and experiment, casting doubt on the validity of the opacity models. The purpose of the new experiments is to make corroborating measurements at the same densities and temperatures, with the initial measurements made at a temperature of 160 eV and an electron density of 0.7 × 1022 cm-3. The X-ray hot spots of a laser-driven hohlraum are not in LTE, and the iron must be shielded from a direct line-of-sight to obtain the data [Perry et al., Phys. Rev. B 54, 5617 (1996)]. This shielding is provided either with the internal structure (e.g., baffles) or external wall shapes that divide the hohlraum into a laser-heated portion and an LTE portion. In contrast, most inertial confinement fusion hohlraums are simple cylinders lacking complex gold walls, and the design codes are not typically applied to targets like those for the opacity experiments. We will discuss the initial basis for the modeling using LASNEX, and the subsequent modeling of five different hohlraum geometries that have been fielded on the NIF to date. This includes a comparison of calculated and measured radiation temperatures.

  2. NASCA Report 2: Longitudinal Study of Relationship of Exposure to Space Radiation and Risk of Lens Opacity

    Science.gov (United States)

    Chylack, Leon T., Jr.; Peterson, Leif E.; Feiveson, Alan H.; Tung, William H.; Wear, Mary L.; Marak, Lisa J.; Hardy, Dale S.; Cucinotta, Francis A.

    2011-01-01

    The NASA Study of Cataract in Astronauts (NASCA) was a five-year longitudinal study of the effect of space radiation exposure on the severity/progression of nuclear (N), cortical (C), and posterior subcapsular (PSC) lens opacities. It began in 2003 and was completed in December, 2009. Participants included 171 consenting astronauts who flew at least one mission in space, and comparison subjects consisted of three groups, a) 53 astronauts who had not flown in space, b) 95 military aircrew personnel, and c) 99 non-aircrew, ground-based subjects.

  3. Glass consistency and glass performance

    International Nuclear Information System (INIS)

    Plodinec, M.J.; Ramsey, W.G.

    1994-01-01

    Glass produced by the Defense Waste Processing Facility (DWPF) will have to consistently be more durable than a benchmark glass (evaluated using a short-term leach test), with high confidence. The DWPF has developed a Glass Product Control Program to comply with this specification. However, it is not clear what relevance product consistency has on long-term glass performance. In this report, the authors show that DWPF glass, produced in compliance with this specification, can be expected to effectively limit the release of soluble radionuclides to natural environments. However, the release of insoluble radionuclides to the environment will be limited by their solubility, and not glass durability

  4. Colloidal glasses

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Colloidal glasses. Glassy state is attained when system fails to reach equilibrium due to crowding of constituent particles. In molecular glasses, glassy state is reached by rapidly lowering the temperature. In colloidal glasses, glassy state is reached by increasing the ...

  5. Opacity broadening and interpretation of suprathermal CO linewidths: Macroscopic turbulence and tangled molecular clouds

    Science.gov (United States)

    Hacar, A.; Alves, J.; Burkert, A.; Goldsmith, P.

    2016-06-01

    Context. Since their first detection in the interestellar medium, (sub-)millimeter line observations of different CO isotopic variants have routinely been employed to characterize the kinematic properties of the gas in molecular clouds. Many of these lines exhibit broad linewidths that greatly exceed the thermal broadening expected for the low temperatures found within these objects. These observed suprathermal CO linewidths are assumed to originate from unresolved supersonic motions inside clouds. Aims: The lowest rotational J transitions of some of the most abundant CO isotopologues, 12CO and 13CO, are found to present large optical depths. In addition to well-known line saturation effects, these large opacities present a non-negligible contribution to their observed linewidths. Typically overlooked in the literature, in this paper we aim to quantify the impact of these opacity broadening effects on the current interpretation of the CO suprathermal line profiles. Methods: Combining large-scale observations and LTE modeling of the ground J = 1-0 transitions of the main 12CO, 13CO, C18O isotopologues, we have investigated the correlation of the observed linewidths as a function of the line opacity in different regions of the Taurus molecular cloud. Results: Without any additional contributions to the gas velocity field, a large fraction of the apparently supersonic (ℳ ~ 2-3) linewidths measured in both 12CO and 13CO (J = 1-0) lines can be explained by the saturation of their corresponding sonic-like, optically thin C18O counterparts assuming standard isotopic fractionation. Combined with the presence of multiple components detected in some of our C18O spectra, these opacity effects also seem to be responsible for most of the highly supersonic linewidths (ℳ > 8-10) detected in some of the broadest 12CO and 13CO spectra in Taurus. Conclusions: Our results demonstrate that most of the suprathermal 12CO and 13CO linewidths reported in nearby clouds like Taurus

  6. Silicate glasses

    International Nuclear Information System (INIS)

    Lutze, W.

    1988-01-01

    Vitrification of liquid high-level radioactive wastes has received the greatest attention, world-wide, compared to any other HLW solidification process. The waste form is a borosilicate-based glass. The production of phosphate-based glass has been abandoned in the western world. Only in the Soviet Union are phosphate-based glasses still being developed. Vitrification techniques, equipment and processes and their remote operation have been developed and studied for almost thirty years and have reached a high degree of technical maturity. Industrial demonstration of the vitrification process has been in progress since 1978. This chapter is a survey of world-wide research and development efforts in nuclear waste glasses and its production technology. The principal glasses considered are silicate glasses which contain boron, i.e., borosilicate glasses

  7. Laboratory testing of LITCO glasses

    International Nuclear Information System (INIS)

    Ellison, A.; Wolf, S.; Buck, E.; Luo, J.S.; Dietz, N.; Bates, J.K.; Ebert, W.L.

    1995-01-01

    The purpose of this program is to measure, the intermediate and long-term durability of glasses developed by Lockheed Idaho Technology Co. (LITCO) for the immobilization of calcined radioactive wastes. The objective is to use accelerated corrosion tests as an aid in developing durable waste form compositions. This is a report of tests performed on two LITCO glass compositions, Formula 127 and Formula 532. The main avenue for release of radionuclides into the environment in a geologic repository is the reaction of a waste glass with ground water, which alters the glass and releases its components into solution. These stages in glass corrosion are analyzed by using accelerated laboratory tests in which the ratio of sample surface area to solution volume, SA/V, is varied. At low SA/V, the solution concentrations of glass corrosion products remain low and the reaction approaches the forward rate. At higher SA/V the solution approaches saturation levels for glass corrosion products. At very high SA/V the solution is rapidly saturated in glass corrosion products and secondary crystalline phases precipitate. Tests at very high SA/V provide information about the composition of the solution at saturation or, when no solution is recovered, the identities and the order of appearance of secondary crystalline phases. Tests were applied to Formula 127 and Formula 532 glasses to provide information about the interim and long-term stages in glass corrosion

  8. Transferability of glass lens molding

    Science.gov (United States)

    Katsuki, Masahide

    2006-02-01

    Sphere lenses have been used for long time. But it is well known that sphere lenses theoretically have spherical aberration, coma and so on. And, aspheric lenses attract attention recently. Plastic lenses are molded easily with injection machines, and are relatively low cost. They are suitable for mass production. On the other hand, glass lenses have several excellent features such as high refractive index, heat resistance and so on. Many aspheric glass lenses came to be used for the latest digital camera and mobile phone camera module. It is very difficult to produce aspheric glass lenses by conventional process of curve generating and polishing. For the solution of this problem, Glass Molding Machine was developed and is spreading through the market. High precision mold is necessary to mold glass lenses with Glass Molding Machine. The mold core is ground or turned by high precision NC aspheric generator. To obtain higher transferability of the mold core, the function of the molding machine and the conditions of molding are very important. But because of high molding temperature, there are factors of thermal expansion and contraction of the mold and glass material. And it is hard to avoid the factors. In this session, I introduce following items. [1] Technology of glass molding and the machine is introduced. [2] The transferability of glass molding is analyzed with some data of glass lenses molded. [3] Compensation of molding shape error is discussed with examples.

  9. The Opacity of Russian-Ukrainian Energy Relations

    International Nuclear Information System (INIS)

    Dubien, A.

    2007-01-01

    Energy issues lie at the heart of Ukraine's economic, political and strategic challenges. A year after the 'orange revolution', the 'gas war' served to highlight the country's vulnerable position, being 80% dependent on imports of gas and having the world's most energy hungry economy. The 2005 crisis also highlighted the extreme opacity of the country's bilateral relations with Russia, which are governed as much by the interests surrounding Gazprom's relations as by those of the state. Yanukovich's return to power in the summer of 2006 coincided with a relative appeasement of relations with Moscow and a new division of spheres of influence in the Ukrainian energy sector. (author)

  10. Recycle Glass in Foam Glass Production

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses...... in foam glass industry and the supply sources and capacity of recycle glass....

  11. USEMS & GLASS: investigator-driven frontier research in earthquake physics. Ground-breaking research in Europe enhances outreach to the general public

    Science.gov (United States)

    Mariano, S.; di Toro, G.; Collettini, C.; Usems Team; Glass Team

    2011-12-01

    USEMS and GLASS are two projects financed by the European Research Council (ERC) as part of the ERC starting grants scheme within the FP7 framework. The rationale behind the funding scheme is to support some of the most promising scientific endeavours in Europe that are being led by young researchers, and to emphasize the excellence of individual ideas rather than specific research areas; in other words, to promote bottom-up frontier research. The general benefits of this rationale are evident in the two ongoing projects that deal with earthquake physics, as these projects are increasingly recognized in their scientific community. We can say that putting excellence at the heart of European Research strongly contributes to the construction of a European knowledge-based society. From a researcher point-of-view one of the most challenging aspects of these projects is to approach and convey the results of the projects to a general public, contributing to the construction of knowledge-based society. Luckily, media interest and the availability of a number of new communication tools facilitate the outreach of scientific achievements. The largest earthquakes during the last ten years (e.g. Sumatra 2004 and Japan 2011) have received widespread attention in the media world (TV, W.W.W., Newspaper and so on) for months, and successful research projects such as those above also become media protagonists, gaining their space in the media bullring. The USEMS principal investigator and his team have participated in several dissemination events in the Mass Media, such as interviews wit Italian and French TV national broadcasts (RAI Due TG2, RAI Uno Unomattina, Rai Tre Geo & Geo, FRANCE 2); interviews in scientific journals: SCIENCE (Sept. 2010), newspapers and web (Corriere della Sera, Il Gazzettino, Il Messagero, La Stampa, Libero, Il Mattino, Yahoo, ANSA, AdnKronos and AGI); radio (RadioRai Uno, RadioRai Tre Scienza); documentary "Die Eroberung der Alpen" produced by Tangram

  12. A fully blanketed early B star LTE model atmosphere using an opacity sampling technique

    International Nuclear Information System (INIS)

    Phillips, A.P.; Wright, S.L.

    1980-01-01

    A fully blanketed LTE model of a stellar atmosphere with Tsub(e) = 21914 K (thetasub(e) = 0.23), log g = 4 is presented. The model includes an explicit representation of the opacity due to the strongest lines, and uses a statistical opacity sampling technique to represent the weaker line opacity. The sampling technique is subjected to several tests and the model is compared with an atmosphere calculated using the line-distribution function method. The limitations of the distribution function method and the particular opacity sampling method used here are discussed in the light of the results obtained. (author)

  13. Systematic measurements of opacity dependence on temperature, density, and atomic number at stellar interior conditions

    Science.gov (United States)

    Nagayama, Taisuke

    2017-10-01

    Model predictions for iron opacity are notably different from measurements performed at matter conditions similar to the boundary between the solar radiation and convection zones. The calculated iron opacities have narrower spectral lines, weaker quasi-continuum at short wavelength, and deeper opacity windows than the measurements. If correct, these measurements help resolve a decade old problem in solar physics. A key question is therefore: What is responsible for the model-data discrepancy? The answer is complex because the experiments are challenging and opacity theories depend on multiple entangled physical processes such as the influence of completeness and accuracy of atomic states, line broadening, contributions from myriad transitions from excited states, and multi-photon absorption processes. To help determine the cause of this discrepancy, a systematic study of opacity variation with temperature, density, and atomic number is underway. Measurements of chromium, iron, and nickel opacities have been performed at two different temperatures and densities. The collection of measured opacities provides constraints on hypotheses to explain the discrepancy. We will discuss implications of measured opacities, experimental errors, and possible opacity model refinements. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  14. Use of Fourier-Domain Optical Coherence Tomography to Evaluate Anterior Stromal Opacities in Donor Corneas

    Directory of Open Access Journals (Sweden)

    Matthew R. Bald

    2013-01-01

    Full Text Available Purpose. To evaluate Fourier-domain optical coherence tomography (FD-OCT as an adjunct to traditional slit lamp examination of donor corneas with suspected Anterior Stromal Opacities. Methods. Seven corneas suspected of having anterior stromal opacities by slit lamp examination were evaluated with FD-OCT. Each cornea was evaluated to confirm the presence of opacity and, if present, the depth of opacity was measured. Results. The opacity depth ranged from 82 μm to 624 μm. The initial slit lamp impressions of five of the seven corneas were confirmed by OCT. In two corneas, the OCT findings were different from the initial slit lamp impressions. Slit lamp examination of the first cornea gave the impression of anterior stromal scarring, but OCT showed that the opacity was limited to the epithelium. Slit lamp examination of the second cornea suggested opacity limited to the epithelium, but OCT identified significant sub-Bowman's scarring. In all cases, the Eye Bank Technicians reported that the location and depth of corneal opacity were more sharply defined by OCT than by slit lamp. Conclusion. The high resolution of OCT makes it easier to determine the location of corneal opacities compared to slit lamp examinations. This enhanced visualization can improve decisions regarding transplant suitability of donor corneas.

  15. Experimental study of self-backlighting method for opacity

    International Nuclear Information System (INIS)

    Ding Yaonan; Yang Jiamin; Li Sanwei; Cao Leifeng; Wang Yaomei; Zhang Wenhai; Chen Bo; Yu Yanning; Wang Hongbin

    2001-01-01

    Self-backlighting method for opacity measurement has been suggested and studied, based on the actual condition of Xingguang II laser facility. An 80 J and 350 nm laser, which has a duration of about 700 ps, irradiates on a newly designed target and creates intense X-ray radiation acting as both heating source and backlighter source. The heated sample has been spatially imaged to obtain X-ray spectra from X-ray source region, transmission region and self-emission region of the sample at the same shot by spatially resolved transmission grating spectrometer in which dispersed X-ray is recorded by X-ray CCD. The samples are low-Z CH foam with density of 0.042 g/cm 3 , thickness of 42 μm and mid-Z Al with density of 2.7 g/cm 3 , thickness of 0.5 μm or 1.0 μm. Mass absorption coefficients of the heated sample as function of the photon energy have been obtained experimentally in the same shot. The spectra line emitted from the heated CH foam has also been measured by OHM crystal spectrometer, which has been used to determine the temperature of the sample. The experimental results for opacity of carbon have been discussed

  16. TIPTOPbase: the Iron Project and the Opacity Project Atomic Database

    Science.gov (United States)

    Mendoza, Claudio; Nahar, Sultana; Pradhan, Anil; Seaton, Micheal; Zeippen, Claude

    2001-05-01

    The Opacity Project, the IRON Project, and the RmaX Network (The Opacity Project Team, Vol.1,2), IOPP, Bristol (1995,1996); Hummer et al., Astron. Astrophys. 279, 298 (1993) are international computational efforts concerned with the production of high quality atomic data for astrophysical applications. Research groups from Canada, France, Germany, UK, USA and Venezuela are involved. Extensive data sets containing accurate energy levels, f-values, A-values, photoionisation cross sections, collision strengths, recombination rates, and opacitites have been computed for cosmically abundant elements using state-of-the-art atomic physics codes. Their volume, completeness and overall accuracy are presently unmatched in the field of laboratory astrophysics. Some of the data sets have been available since 1993 from a public on-line database service referred to as TOPbase (Cunto et al Astron. Astrophys. 275), L5 (1993), ( http://cdsweb.u-strasbg.fr/OP.html at CDS France, and http://heasarc.gsfc.nasa.gov/topbase, at NSAS USA). We are currently involved in a major effort to scale the existing database services to develop a robust platform for the high-profile dissemination of atomic data to the scientific community within the next 12 months. (Partial support from the NSF and NASA is acknowledged.)

  17. Statistical approach for calculating opacities of high-Z plasmas

    International Nuclear Information System (INIS)

    Nishikawa, Takeshi; Nakamura, Shinji; Takabe, Hideaki; Mima, Kunioki

    1992-01-01

    For simulating the X-ray radiation from laser produced high-Z plasma, an appropriate atomic modeling is necessary. Based on the average ion model, we have used a rather simple atomic model for opacity calculation in a hydrodynamic code and obtained a fairly good agreement with the experiment on the X-ray spectra from the laser-produced plasmas. We have investigated the accuracy of the atomic model used in the hydrodynamic code. It is found that transition energies of 4p-4d, 4d-4f, 4p-5d, 4d-5f and 4f-5g, which are important in laser produced high-Z plasma, can be given within an error of 15 % compared to the values by the Hartree-Fock-Slater (HFS) calculation and their oscillator strengths obtained by HFS calculation vary by a factor two according to the difference of charge state. We also propose a statistical method to carry out detail configuration accounting for electronic state by use of the population of bound electrons calculated with the average ion model. The statistical method is relatively simple and provides much improvement in calculating spectral opacities of line radiation, when we use the average ion model to determine electronic state. (author)

  18. Light element opacities of astrophysical interest from ATOMIC

    Energy Technology Data Exchange (ETDEWEB)

    Colgan, J.; Kilcrease, D. P.; Magee, N. H. Jr.; Armstrong, G. S. J.; Abdallah, J. Jr.; Sherrill, M. E. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fontes, C. J.; Zhang, H. L.; Hakel, P. [Computational Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-07-11

    We present new calculations of local-thermodynamic-equilibrium (LTE) light element opacities from the Los Alamos ATOMIC code for systems of astrophysical interest. ATOMIC is a multi-purpose code that can generate LTE or non-LTE quantities of interest at various levels of approximation. Our calculations, which include fine-structure detail, represent a systematic improvement over previous Los Alamos opacity calculations using the LEDCOP legacy code. The ATOMIC code uses ab-initio atomic structure data computed from the CATS code, which is based on Cowan's atomic structure codes, and photoionization cross section data computed from the Los Alamos ionization code GIPPER. ATOMIC also incorporates a new equation-of-state (EOS) model based on the chemical picture. ATOMIC incorporates some physics packages from LEDCOP and also includes additional physical processes, such as improved free-free cross sections and additional scattering mechanisms. Our new calculations are made for elements of astrophysical interest and for a wide range of temperatures and densities.

  19. Effects of Silicone Hydrogel Contact Lens Application on Corneal High-order Aberration and Visual Guality in Patients with Corneal Opacities

    Directory of Open Access Journals (Sweden)

    Sevda Aydın Kurna

    2012-03-01

    Full Text Available Pur po se: Evaluation of the corneal high-order aberrations and visual quality changes after application of silicone hydrogel contact lenses in patients with corneal opacities due to various etiologies. Ma te ri al and Met hod: Fifteen eyes of 13 patients with corneal opacities were included in the study. During the ophthalmologic examination before and after contact lens application, visual acuity was measured with Snellen acuity chart and contrast sensitivity - with Bailey-Lowie Charts in letters. Aberrations were measured with corneal aberrometer (NIDEK Magellan Mapper under a naturally dilated pupil. Spherical aberration, coma, trefoil, irregular astigmatism and total high-order root mean square (RMS values were recorded. Measurements were repeated with balafilcon A lenses (PureVision 2 HD, B&L on all patients. Re sults: Patient age varied between 23 and 50 years. Two eyes had subepithelial infiltrates due to adenoviral keratitis, 1 had nebulae due to previous infections or trauma, and 2 had Salzmann’s nodular degeneration. We observed a mean increase of 1 line in visual acuity and 5 letters in contrast sensitivity with contact lenses versus glasses in the patients. Mean RMS values of spherical aberration, irregular astigmatism and total high-order aberrations decreased significantly with contact lenses. Dis cus si on: Silicone hydrogel soft contact lenses may improve visual quality by decreasing the corneal aberrations in patients with corneal opacities. (Turk J Ophthalmol 2012; 42: 97-102

  20. Cosmos & Glass

    DEFF Research Database (Denmark)

    Beim, Anne

    1996-01-01

    The article unfolds the architectural visions of glass by Bruno Taut. It refers to inspirations by Paul Sheerbart and litterature and the Crystal Chain, also it analyses the tectonic univers that can be found in the glass pavillion for the Werkbund exposition in Cologne....

  1. Glass Glimpsed

    DEFF Research Database (Denmark)

    Lock, Charles

    2015-01-01

    Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology.......Glass in poetry as it reflects the viewer and as its power of reflection are both reduced and enhanced by technology....

  2. Radiation-optical properties of the glasses for the space application

    International Nuclear Information System (INIS)

    Akishin, A.I.; Tseplyaev, L.I.

    2006-01-01

    The data are presented and generalized on variations of optical properties of glass and light guides under simulative cosmic ionizing radiation. It is shown that changes in optical properties (coloration, bleaching, opacity, luminescence) under ionizing radiation are associated with color centers formation and annealing [ru

  3. Spin glasses

    CERN Document Server

    Bovier, Anton

    2007-01-01

    Spin glass theory is going through a stunning period of progress while finding exciting new applications in areas beyond theoretical physics, in particular in combinatorics and computer science. This collection of state-of-the-art review papers written by leading experts in the field covers the topic from a wide variety of angles. The topics covered are mean field spin glasses, including a pedagogical account of Talagrand's proof of the Parisi solution, short range spin glasses, emphasizing the open problem of the relevance of the mean-field theory for lattice models, and the dynamics of spin glasses, in particular the problem of ageing in mean field models. The book will serve as a concise introduction to the state of the art of spin glass theory, usefull to both graduate students and young researchers, as well as to anyone curious to know what is going on in this exciting area of mathematical physics.

  4. An Empirical Determination of the Intergalactic Background Light Using Near-Infrared Deep Galaxy Survey Data Out to 5 Micrometers and the Gamma-Ray Opacity of the Universe

    Science.gov (United States)

    Scully, Sean T.; Malkan, Matthew A.; Stecker, Floyd W.

    2014-01-01

    We extend our previous model-independent determination of the intergalactic background light, based purely on galaxy survey data, out to a wavelength of 5 micrometers. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. We further determine a 68% confidence upper and lower limit on the opacity of the universe to gamma-rays up to energies of 1.6/(1 + z) terraelectron volts. A comparison of our lower limit redshift-dependent opacity curves to the opacity limits derived from the results of both ground-based air Cerenkov telescope and Fermi-LAT observations of PKS 1424+240 allows us to place a new upper limit on the redshift of this source, independent of IBL modeling.

  5. Opacity Build-up in Impulsive Relativistic Sources

    International Nuclear Information System (INIS)

    Granot, Jonathan; Cohen-Tanugi, Johann; Silva, Eduardo do Couto e

    2007-01-01

    Opacity effects in relativistic sources of high-energy gamma-rays, such as gamma-ray bursts (GRBs) or Blazars, can probe the Lorentz factor of the outflow as well as the distance of the emission site from the source, and thus help constrain the composition of the outflow (protons, pairs, magnetic field) and the emission mechanism. Most previous works consider the opacity in steady state. Here we study the effects of the time dependence of the opacity to pair production (γγ → e + e - ) in an impulsive relativistic source, which may be relevant for the prompt gamma-ray emission in GRBs or flares in Blazars. We present a simple, yet rich, semi-analytic model for the time and energy dependence of the optical depth, τγγ, in which a thin spherical shell expands ultra-relativistically and emits isotropically in its own rest frame over a finite range of radii, R 0 (le) R (le) R 0 +ΔR. This is particularly relevant for GRB internal shocks. We find that in an impulsive source (ΔR ∼ 0 ), while the instantaneous spectrum (which is typically hard to measure due to poor photon statistics) has an exponential cutoff above the photon energy (var e psilon)1(T) where tγγ((var e psilon)1) = 1, the time integrated spectrum (which is easier to measure) has a power-law high-energy tail above the photon energy (var e psilon)1* ∼ (var e psilon)1(ΔT) where ΔT is the duration of the emission episode. Furthermore, photons with energies (var e psilon) > (var e psilon)1* are expected to arrive mainly near the onset of the spike in the light curve or flare, which corresponds to the short emission episode. This arises since in such impulsive sources it takes time to build-up the (target) photon field, and thus the optical depth τγγ((var e psilon)) initially increases with time and (var e psilon)1(T) correspondingly decreases with time, so that photons of energy (var e psilon) > (var e psilon)1* are able to escape the source mainly very early on while (var e psilon)1(T) > (var

  6. Co-registration of pre-operative CT with ex vivo surgically excised ground glass nodules to define spatial extent of invasive adenocarcinoma on in vivo imaging: a proof-of-concept study

    Energy Technology Data Exchange (ETDEWEB)

    Rusu, Mirabela [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); GE Global Research, Niskayuna, NY (United States); Rajiah, Prabhakar [UT Southwestern Medical Center, Dallas, TX (United States); Cleveland Medical Center and Case Western Reserve University, University Hospitals, Cleveland, OH (United States); Gilkeson, Robert; Yang, Michael; Donatelli, Christopher; Linden, Philip [Cleveland Medical Center and Case Western Reserve University, University Hospitals, Cleveland, OH (United States); Thawani, Rajat; Madabhushi, Anant [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); Jacono, Frank J. [Cleveland Medical Center and Case Western Reserve University, University Hospitals, Cleveland, OH (United States); Louis Stokes Cleveland VA Medical Center, Cleveland, OH (United States)

    2017-10-15

    To develop an approach for radiology-pathology fusion of ex vivo histology of surgically excised pulmonary nodules with pre-operative CT, to radiologically map spatial extent of the invasive adenocarcinomatous component of the nodule. Six subjects (age: 75 ± 11 years) with pre-operative CT and surgically excised ground-glass nodules (size: 22.5 ± 5.1 mm) with a significant invasive adenocarcinomatous component (>5 mm) were included. The pathologist outlined disease extent on digitized histology specimens; two radiologists and a pulmonary critical care physician delineated the entire nodule on CT (in-plane resolution: <0.8 mm, inter-slice distance: 1-5 mm). We introduced a novel reconstruction approach to localize histology slices in 3D relative to each other while using CT scan as spatial constraint. This enabled the spatial mapping of the extent of tumour invasion from histology onto CT. Good overlap of the 3D reconstructed histology and the nodule outlined on CT was observed (65.9 ± 5.2%). Reduction in 3D misalignment of corresponding anatomical landmarks on histology and CT was observed (1.97 ± 0.42 mm). Moreover, the CT attenuation (HU) distributions were different when comparing invasive and in situ regions. This proof-of-concept study suggests that our fusion method can enable the spatial mapping of the invasive adenocarcinomatous component from 2D histology slices onto in vivo CT. (orig.)

  7. Co-registration of pre-operative CT with ex vivo surgically excised ground glass nodules to define spatial extent of invasive adenocarcinoma on in vivo imaging: a proof-of-concept study

    International Nuclear Information System (INIS)

    Rusu, Mirabela; Rajiah, Prabhakar; Gilkeson, Robert; Yang, Michael; Donatelli, Christopher; Linden, Philip; Thawani, Rajat; Madabhushi, Anant; Jacono, Frank J.

    2017-01-01

    To develop an approach for radiology-pathology fusion of ex vivo histology of surgically excised pulmonary nodules with pre-operative CT, to radiologically map spatial extent of the invasive adenocarcinomatous component of the nodule. Six subjects (age: 75 ± 11 years) with pre-operative CT and surgically excised ground-glass nodules (size: 22.5 ± 5.1 mm) with a significant invasive adenocarcinomatous component (>5 mm) were included. The pathologist outlined disease extent on digitized histology specimens; two radiologists and a pulmonary critical care physician delineated the entire nodule on CT (in-plane resolution: <0.8 mm, inter-slice distance: 1-5 mm). We introduced a novel reconstruction approach to localize histology slices in 3D relative to each other while using CT scan as spatial constraint. This enabled the spatial mapping of the extent of tumour invasion from histology onto CT. Good overlap of the 3D reconstructed histology and the nodule outlined on CT was observed (65.9 ± 5.2%). Reduction in 3D misalignment of corresponding anatomical landmarks on histology and CT was observed (1.97 ± 0.42 mm). Moreover, the CT attenuation (HU) distributions were different when comparing invasive and in situ regions. This proof-of-concept study suggests that our fusion method can enable the spatial mapping of the invasive adenocarcinomatous component from 2D histology slices onto in vivo CT. (orig.)

  8. Experimental investigation of opacity models for stellar interior, inertial fusion, and high energy density plasmas

    International Nuclear Information System (INIS)

    Bailey, J. E.; Rochau, G. A.; Mancini, R. C.; Iglesias, C. A.; MacFarlane, J. J.; Golovkin, I. E.; Blancard, C.; Cosse, Ph.; Faussurier, G.

    2009-01-01

    Theoretical opacities are required for calculating energy transport in plasmas. In particular, understanding stellar interiors, inertial fusion, and Z pinches depends on the opacities of mid-atomic-number elements over a wide range of temperatures. The 150-300 eV temperature range is particularly interesting. The opacity models are complex and experimental validation is crucial. For example, solar models presently disagree with helioseismology and one possible explanation is inadequate theoretical opacities. Testing these opacities requires well-characterized plasmas at temperatures high enough to produce the ion charge states that exist in the sun. Typical opacity experiments heat a sample using x rays and measure the spectrally resolved transmission with a backlight. The difficulty grows as the temperature increases because the heating x-ray source must supply more energy and the backlight must be bright enough to overwhelm the plasma self-emission. These problems can be overcome with the new generation of high energy density (HED) facilities. For example, recent experiments at Sandia's Z facility [M. K. Matzen et al., Phys. Plasmas 12, 055503 (2005)] measured the transmission of a mixed Mg and Fe plasma heated to 156±6 eV. This capability will also advance opacity science for other HED plasmas. This tutorial reviews experimental methods for testing opacity models, including experiment design, transmission measurement methods, accuracy evaluation, and plasma diagnostics. The solar interior serves as a focal problem and Z facility experiments illustrate the techniques.

  9. A Comparison of Keyword Subject Searching on Six British University OPACs Online Public Access Catalogs.

    Science.gov (United States)

    Aanonson, John

    1987-01-01

    Compares features of online public access catalogs (OPACs) at six British universities: (1) Cambridge; (2) Hull; (3) Newcastle; (4) Surrey; (5) Sussex; and (6) York. Results of keyword subject searches on two topics performed on each of the OPACs are reported and compared. Six references are listed. (MES)

  10. Bibliographic Displays in OPACs and Web Catalogs: How Well Do They Comply with Display Guidelines?

    Science.gov (United States)

    Cherry, Joan M.

    1998-01-01

    Evaluation of data from assessments of full bibliographic displays in academic library OPACs (online public access catalogs) and World Wide Web catalogs against a checklist of desirable features found that OPAC displays scored 58% and Web displays scored 60%. Discusses weaknesses, focusing on those found in the majority of the displays…

  11. The Searching Behavior of Remote Users: A Study of One Online Public Access Catalog (OPAC).

    Science.gov (United States)

    Kalin, Sally W.

    1991-01-01

    Describes a study that was conducted to determine whether the searching behavior of remote users of LIAS (Library Information Access System), Pennsylvania State University's online public access catalog (OPAC), differed from those using the OPAC within the library. Differences in search strategies and in user satisfaction are discussed. (eight…

  12. Opacity calculations and Saha's equation for high Z elements

    International Nuclear Information System (INIS)

    Godwal, B.K.; Sikka, S.K.

    1977-01-01

    Opacity calculations are needed for energy transport by radiation for high Z element plasmas as these have been suggested as temper materials in laser, electron beam and heavy ion fusion schemes. The pressure ionised modified form of Saha's ionisation equation has been used to obtain the free electron density, populations of various ionic species and the populations of various energy states for a given ion. Results are presented for two typical elements; tungsten and uranium. The ionisation potential have been evaluated using the Bohr's formula with suitable effective screened charges for ions. The results show that for uranium, even at a temperature of 10 kev, the K shell is intact. The reliability of the Saha's equation solution has been checked by comparing the equation of state (total pressure vs total energy curve) with that given by the Thomas-Fermi-Dirac equation of state. The agreement between the two is good from temperature upwards of 0.2 kev. (author)

  13. Neutrino opacities in kaon condensation and evolution of neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Muto, Takumi [Chiba Institute of Technology, Dept. of Physics, Narashino, Chiba (Japan); Yasuhira, Masatomi [Kyoto Univ., Yukawa Institute for Theoretical Physics, Kyoto (Japan); Tatsumi, Toshitaka [Kyoto Univ., Dept. of Physics, Kyoto (Japan); Iwamoto, Naoki [Kagawa Univ., Faculty of Engineering, Takamatsu, Kagawa (Japan)

    2002-09-01

    The neutrino mean free paths are obtained in kaon condensates realized from hot neutron-star matter. Kaon-induced neutrino absorption processes (KA), {nu}{sub e}N {yields} e{sup -}N (N stands for the nucleon), which are unique in the presence of kaon condensates, are mainly considered in nondegenerate neutrino case. The mean free paths for the KA processes are compared with the neutrino scatterings (S), {nu}{sub e}N {yields} {nu}{sub e}N. It is shown that the mean free paths for KA are shorter than the ordinary two-nucleon processes, {nu}{sub e}nN {yields} e{sup -}pN by several orders of magnitude when the temperature is not very high. However, the scattering processes have a dominant contribution to the neutrino opacities as compared with KA, so that KA has a minor effect on the thermal and dynamical evolution of protoneutron stars. (author)

  14. Opacity measurements in shock-generated argon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D.

    1993-07-01

    Dense plasmas having uniform and constant density and temperature are generated by passage of a planar shock wave through gas. The opacity of the plasma is accurately measured versus wavelength by recording the risetime of emitted light. This technique is applicable to a wide variety of species and plasma conditions. Initial experiments in argon have produced plasmas with 2 eV temperatures, 0.004--0.04 g/cm{sup 3} densities, and coupling parameters {Gamma} {approximately}0.3--0.7. Measurements in visible light are compared with calculations using the HOPE code. An interesting peak in the capacity at 400 nm is observed for the first time and is identified with the 4s-5p transition in excited neutral argon atoms.

  15. Formation of Planetary Populations I: Metallicity & Envelope Opacity Effects

    Science.gov (United States)

    Alessi, Matthew; Pudritz, Ralph E.

    2018-05-01

    We present a comprehensive body of simulations of the formation of exoplanetary populations that incorporate the role of planet traps in slowing planetary migration. The traps we include in our model are the water ice line, the disk heat transition, and the dead zone outer edge. We reduce our model parameter set to two physical parameters: the opacity of the accreting planetary atmospheres (κenv) and a measure of the efficiency of planetary accretion after gap opening (fmax). We perform planet population synthesis calculations based on the initial observed distributions of host star and disk properties - their disk masses, lifetimes, and stellar metallicities. We find the frequency of giant planet formation scales with disk metallicity, in agreement with the observed Jovian planet frequency-metallicity relation. We consider both X-ray and cosmic ray disk ionization models, whose differing ionization rates lead to different dead zone trap locations. In both cases, Jovian planets form in our model out to 2-3 AU, with a distribution at smaller radii dependent on the disk ionization source and the setting of envelope opacity. We find that low values of κenv (0.001-0.002 cm2 g-1) and X-ray disk ionization are necessary to obtain a separation between hot Jupiters near 0.1 AU, and warm Jupiters outside 0.6 AU, a feature present in the data. Our model also produces a large number of super Earths, but the majority are outside of 2 AU. As our model assumes a constant dust to gas ratio, we suggest that radial dust evolution must be taken into account to reproduce the observed super Earth population.

  16. GLASS BOX

    National Research Council Canada - National Science Library

    Curtis, Laura

    2008-01-01

    The goals of this effort were to develop Glass Box capabilities to allow for the capturing of analyst activities and the associated data resources, track and log the results of automated processing...

  17. Study of volume recombination and radiation opacity effects in Alcator C-Mod

    International Nuclear Information System (INIS)

    Terry, J.L.; Lipschultz, B.; Pigarov, A.Y.; Boswell, C.; Krasheninnikov, S.I.; LaBombard, B.; Pappas, D.A.

    1998-01-01

    Observations of significant volume recombination within the Alcator C-Mod divertor plasma and in the edge plasma (MARFE) are described. The recombination occurs in regions where T e approx-lt 1 eV and n e approx-gt 1x10 21 m -3 . The determinations of the recombination rates are made by measuring the D 0 Lyman and/or Balmer spectra and by using a collisional radiative model describing the level populations, ionization and recombination of D 0 . In regions of strong recombination the upper levels (n approx-gt 4) populations are close to those determined by Saha-Boltzmann distribution and are independent of the ground state density. Thus the intensities of lines from these levels are related to the recombination rate, and curves determining the number of open-quote recombinations per photon close-quote are calculated. Ly β line emission is shown to be trapped in some cases, meaning that Ly α can be strongly trapped. Since opacity affects the recombination rates, the effects of the trapping of Ly α,β photons on the open-quote recombinations per photon close-quote curves are calculated and considered in the recombination rate determinations. Total recombination rates in the detached divertor plasma and in MARFEs located at the periphery of the main plasma are determined. Recombination can be a significant sink for ions. copyright 1998 American Institute of Physics

  18. Influence of Some Nuclear Waste on The Durability and Mechanical Properties of Borosilicate glass

    International Nuclear Information System (INIS)

    El-Alaily, N.A.

    2003-01-01

    Various glass systems have been shown to be suitable for producing waste glass forms that are thermally and mechanically stable and exhibit good chemical durability. In this study borosilicate glass containing sodium oxide and aluminum oxide was prepared as a host for high level nuclear waste. The glass durability when the samples were immersed either in distilled water or ground water at 70 degree was studied. The density, porosity and mechanical properties were also investigated. The effects of exposing the samples immersed in groundwater to gamma rays in the glass durability and all other mentioned properties were also studied. The results showed that immersing the glass in ground water causing a decrease in the glass durability. The exposure of the glass immersed in ground water to the gamma rays increases the durability of the glass. The mechanical properties of the prepared glass were good. Although these properties decrease for the corroded glass but they were still good

  19. Detailed-term-accounting approximation calculations of the radiative opacity of aluminum plasmas: A systematic study

    International Nuclear Information System (INIS)

    Zeng Jiaolong; Yuan Jianmin

    2002-01-01

    The spectrally resolved radiative opacity and the Rosseland and Planck mean opacities are calculated by using the detailed-term-accounting approximation for aluminum plasmas with varieties of density and temperature. The results are presented along a 40 eV isothermal sequence, a 0.01 g/cm 3 isodense sequence, and a sequence with average ionization degree Z*∼7.13. Particular attention is given to the influence of the detailed treatment of spectral lines on the Rosseland mean opacity under different thermodynamical conditions. The results show that at densities of 0.004 g/cm 3 and higher, the opacities are not very sensitive to the spectral linewidth within a reasonable range. As examples, the Rosseland mean opacity, which is most sensitive to the detailed linewidth, at 40 eV and 0.004 g/cm 3 changes no more than 15%, when we change the electron impact spectral linewidth artificially by reducing it by 50% or increasing it twice, and at 40 eV and 0.1 g/cm 3 it changes less than 5%. For comparison, we also carried out calculations by using an average atom model. For the Rosseland mean opacities, the two models show quite large differences, in particular at low densities, while for the Planck mean opacities the results of the two models are much closer

  20. Influence of detector collimation and beam pitch for identification and image quality of ground-glass attenuation and nodules on 16- and 64-detector row CT systems: experimental study using chest phantom.

    Science.gov (United States)

    Ohno, Yoshiharu; Koyama, Hisanobu; Kono, Astushi; Terada, Mari; Inokawa, Hiroyasu; Matsumoto, Sumiaki; Sugimura, Kazuro

    2007-12-01

    The purpose of the present study was to determine the influence of detector collimation and beam pitch for identification and image quality of ground-glass attenuation (GGA) and nodules on 16- and 64-detector row CTs, by using a commercially available chest phantom. A chest CT phantom including simulated GGAs and nodules was scanned with different detector collimations, beam pitches and tube currents. The probability and image quality of each simulated abnormality was visually assessed with a five-point scoring system. ROC-analysis and ANOVA were then performed to compare the identification and image quality of either protocol with standard values. Detection rates of low-dose CTs were significantly reduced when tube currents were set at 40mA or less by using detector collimation 16 and 64x0.5mm and 16 and 32mmx1.0mm for low pitch, and at 100mA or less by using detector collimation 16 and 64x0.5mm and 16 and 32mmx1.0mm for high pitch (pdetector collimation 16 and 64x0.5mm and 16 and 32x1.0mm for low pitch, and at 150mA or less by using detector collimation 16 and 64x0.5mm and 16 and 32x1.0mm for high pitch (pDetector collimation and beam pitch were important factors for the image quality and identification of GGA and nodules by 16- and 64-detector row CT.

  1. Characterization study of industrial waste glass as starting material ...

    African Journals Online (AJOL)

    In present study, an industrial waste glass was characterized and the potential to assess as starting material in development of bioactive materials was investigated. A waste glass collected from the two different glass industry was grounded to fine powder. The samples were characterized using X-ray fluorescence (XRF), ...

  2. Perilaku Pemustaka Dalam Temu Kembali Koleksi Dengan Menggunakan OPAC Berbasis SLIMS

    Directory of Open Access Journals (Sweden)

    Mujiati Mujiati

    2014-07-01

    Full Text Available Abstract: An  increase of  library collection and  information explosion causes  problems  on    information  retrieval  for  library  users.  Those explosion will be helpful for users using Online Public Access Catalog (OPAC. This article tries to explore the use of OPAC based SLIMs on STAIN Ponorogo  library. OPAC proves  to help users  on  retrieval  be easier and faster, beside its obstacles

  3. Caecal cancer presenting as leg erythema and a lung opacity.

    Science.gov (United States)

    Das, Archik; Hureibi, Khalid; Tayyab, Muhammad; McCullough, Peter

    2017-09-07

    Necrotising infection of the lower limb is a rare presentation for colorectal malignancy. We report a case of a perforated caecal adenocarcinoma presenting with right leg erythema, pain and swelling in the presence of a right lower lobe lung opacity. Following initial debridement and washout, CT imaging demonstrated a thickened terminal ileum, caecum and appendix, in keeping with primary malignancy. This fed the right-sided lower limb sepsis tracking down from the medial aspect of the psoas muscle to give rise to the multiloculated collection seen in the adductor compartment. The lung lesion measured 16 mm and was metastatic. The patient was successfully managed with a subtotal colectomy and an end ileostomy. The biopsy confirmed an adenocarcinoma (T4N1M1). We highlight the importance of perforated colonic carcinoma as a leading differential for lower limb abscesses. Suspicions should be raised further if accompanied by rounded opacifications on plain film radiography of the lungs. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. Proving Opacity of Transactional Memory with Early Release

    Directory of Open Access Journals (Sweden)

    Siek Konrad

    2015-12-01

    Full Text Available Transactional Memory (TM is an alternative way of synchronizing concurrent accesses to shared memory by adopting the abstraction of transactions in place of low-level mechanisms like locks and barriers. TMs usually apply optimistic concurrency control to provide a universal and easy-to-use method of maintaining correctness. However, this approach performs a high number of aborts in high contention workloads, which can adversely affect performance. Optimistic TMs can cause problems when transactions contain irrevocable operations. Hence, pessimistic TMs were proposed to solve some of these problems. However, an important way of achieving efficiency in pessimistic TMs is to use early release. On the other hand, early release is seemingly at odds with opacity, the gold standard of TM safety properties, which does not allow transactions to make their state visible until they commit. In this paper we propose a proof technique that makes it possible to demonstrate that a TM with early release can be opaque as long as it prevents inconsistent views.

  5. Opacity and noninear effects on theoretical BL Herculis models

    International Nuclear Information System (INIS)

    Hodson, S.W.; Cox, A.N.; King, D.S.

    1982-01-01

    Linear and nonlinear pulsation models for BL Herculis variables have been constructed to investigate the resonance which seems to occur when the ratio of the second overtone (Pi 2 ) to fundamental (Pi 0 ) radial periods is near 0.5. This resonance is shown to affect the shapes of the light and velocity curves and produce bumps on either ascending or descending light just as far classical Cepheids. Linear theory predicts the resonance to occur at periods between 1.7 and 3.0 days for 0.55 M/sub sun/ and between 2.1 and 4.0 days for 0.75 M/sub sun/ stars at the red and blue edges, respectively, of the stability strip. These periods are rather independent of the composition and opacity tables. However, observations show the resonance to be about 1.7 days for all BL Her variables by noticing that the bump phase switches from descending to ascending light as the period increases. Nonlinear calculations indicate that the linear theory predictions of Pi 2 /Pi 0 are not reliable just at Pi 2 /Pi 0 = 0.5, and the predicted resonance occurs always at the proper period as observed

  6. Glass compositions

    Energy Technology Data Exchange (ETDEWEB)

    France, P W

    1985-05-30

    A fluoride glass for use in the production of optical fibres has an enhanced D/H ratio, preferably such that OD:OH is at least 9:1. In the example, such a glass is prepared by treating with D/sub 2/O a melt comprising 51.53 mole per cent ZrF/sub 4/, 20.47 mole per cent BaF/sub 2/, 5.27 mole per cent LaF/sub 3/, 3.24 mole per cent AlF/sub 3/, and 19.49 mole per cent LiF.

  7. Control of radioactive waste-glass melters

    International Nuclear Information System (INIS)

    Bickford, D.F.; Smith, P.K.; Hrma, P.; Bowan, B.W.

    1987-01-01

    Radioactive waste-glass melters require physical control limits and redox control of glass to assure continuous operation, and maximize production rates. Typical waste-glass melter operating conditions, and waste-glass chemical reaction paths are discussed. Glass composition, batching and melter temperature control are used to avoid the information of phases which are disruptive to melting or reduce melter life. The necessity and probable limitations of control for electric melters with complex waste feed compositions are discussed. Preliminary control limits, their bases, and alternative control methods are described for use in the Defense Waste Processing Facility (DWPF) at the US Department of Energy's Savannah River Plant (SRP), and at the West Valley Demonstration Project (WVDP). Slurries of simulated high level radioactive waste and ground glass frit or glass formers have been isothermally reacted and analyzed to identify the sequence of the major chemical reactions in waste vitrification, and their effect on waste-glass production rates. Relatively high melting rates of waste batches containing mixtures of reducing agents (formic acid, sucrose) and nitrates are attributable to exothermic reactions which occur at critical stages in the vitrification process. The effect of foaming on waste glass production rates is analyzed, and limits defined for existing waste-glass melters, based upon measurable thermophysical properties. Through balancing the high nitrate wastes of the WVDP with reducing agents, the high glass melting rates and sustained melting without foaming required for successful WVDP operations have been demonstrated. 65 refs., 4 figs., 15 tabs

  8. Large Enhancement in High-Energy Photoionization of Fe XVII and Missing Continuum Plasma Opacity

    Science.gov (United States)

    Nahar, Sultana N.; Pradhan, Anil K.

    2016-06-01

    Aimed at solving the outstanding problem of solar opacity, and radiation transport plasma models in general, we report substantial photoabsorption in the high-energy regime due to atomic core photoexcitations not heretofore considered. In extensive R -matrix calculations of unprecedented complexity for an important iron ion Fe xvii (Fe16 + ), with a wave function expansion of 99 Fe xviii (Fe17 + ) LS core states from n ≤4 complexes (equivalent to 218 fine structure levels), we find (i) up to orders of magnitude enhancement in background photoionization cross sections, in addition to strongly peaked photo-excitation-of-core resonances not considered in current opacity models, and ii) demonstrate convergence with respect to successive core excitations. The resulting increase in the monochromatic continuum, and 35% in the Rosseland mean opacity, are compared with the "higher-than-predicted" iron opacity measured at the Sandia Z -pinch fusion device at solar interior conditions.

  9. A Rare Form of Corneal Opacity Associated with Spondyloepiphyseal Dysplasia Congenita

    Directory of Open Access Journals (Sweden)

    Yuichiro Ishida

    2018-02-01

    Full Text Available A 13-year-old Japanese female diagnosed with spondyloepiphyseal dysplasia congenita (SEDC was referred for ophthalmologic evaluation. Examination with slit-lamp and optical coherence tomography revealed bilateral thin cornea with diffuse corneal opacity which was localised at the posterior stromal depth in the central cornea. Unlike the two previously reported cases of diffuse and nodular patterns of corneal opacity in SEDC, the current case exhibited a rare form of corneal opacity. SEDC is one of the type II collagenopathies, characterised by dwarfism because the mutations in COL2A1 prevent bone growth. Although the existence of type II collagen has not been reported in the human corneal stroma, the aetiology of the opacity in the corneal stroma in SEDC type II collagenopathy is of interest.

  10. Non-LTE H2+ as the source of missing opacity in the solar atmosphere

    Science.gov (United States)

    Swamy, K. S. K.; Stecher, T. P.

    1974-01-01

    The population of the various vibrational levels of the H2+ molecule has been calculated from the consideration of formation and destruction mechanisms. The resulting population is used in calculating the total absorption due to H2+ and is compared with the other known sources of opacity at several optical depths of the solar atmosphere. It is shown that the absorption due to H2+ can probably account for the missing ultraviolet opacity in the solar atmosphere.

  11. Free-free opacity in dense plasmas with an average atom model

    International Nuclear Information System (INIS)

    Shaffer, Nathaniel R.; Ferris, Natalie G.; Colgan, James Patrick; Kilcrease, David Parker; Starrett, Charles Edward

    2017-01-01

    A model for the free-free opacity of dense plasmas is presented. The model uses a previously developed average atom model, together with the Kubo-Greenwood model for optical conductivity. This, in turn, is used to calculate the opacity with the Kramers-Kronig dispersion relations. Furthermore, comparisons to other methods for dense deuterium results in excellent agreement with DFT-MD simulations, and reasonable agreement with a simple Yukawa screening model corrected to satisfy the conductivity sum rule.

  12. Computational Design of Short Pulse Laser Driven Iron Opacity Measurements at Stellar-Relevant Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Madison E. [Univ. of Florida, Gainesville, FL (United States)

    2017-05-20

    Opacity is a critical parameter in the simulation of radiation transport in systems such as inertial con nement fusion capsules and stars. The resolution of current disagreements between solar models and helioseismological observations would bene t from experimental validation of theoretical opacity models. Overall, short pulse laser heated iron experiments reaching stellar-relevant conditions have been designed with consideration of minimizing tamper emission and optical depth effects while meeting plasma condition and x-ray emission goals.

  13. Epistemic Opacity, Confirmation Holism and Technical Debt: Computer Simulation in the Light of Empirical Software Engineering

    OpenAIRE

    Newman , Julian

    2015-01-01

    Epistemic opacity vis a vis human agents has been presented as an essential, ineliminable characteristic of computer simulation models resulting from the characteristics of the human cognitive agent. This paper argues, on the contrary, that such epistemic opacity as does occur in computer simulations is not a consequence of human limitations but of a failure on the part of model developers to adopt good software engineering practice for managing human error and ensuring the software artefact ...

  14. How the machine ‘thinks’: Understanding opacity in machine learning algorithms

    Directory of Open Access Journals (Sweden)

    Jenna Burrell

    2016-01-01

    Full Text Available This article considers the issue of opacity as a problem for socially consequential mechanisms of classification and ranking, such as spam filters, credit card fraud detection, search engines, news trends, market segmentation and advertising, insurance or loan qualification, and credit scoring. These mechanisms of classification all frequently rely on computational algorithms, and in many cases on machine learning algorithms to do this work. In this article, I draw a distinction between three forms of opacity: (1 opacity as intentional corporate or state secrecy, (2 opacity as technical illiteracy, and (3 an opacity that arises from the characteristics of machine learning algorithms and the scale required to apply them usefully. The analysis in this article gets inside the algorithms themselves. I cite existing literatures in computer science, known industry practices (as they are publicly presented, and do some testing and manipulation of code as a form of lightweight code audit. I argue that recognizing the distinct forms of opacity that may be coming into play in a given application is a key to determining which of a variety of technical and non-technical solutions could help to prevent harm.

  15. The effect of Livermore OPAL opacities on the evolutionary masses of RR Lyrae stars

    Science.gov (United States)

    Yi, Sukyoung; Lee, Young-Wook; Demarque, Pierre

    1993-01-01

    We have investigated the effect of the new Livermore OPAL opacities on the evolution of horizontal-branch (HB) stars. This work was motivated by the recent stellar pulsation calculations using the new Livermore opacities, which suggest that the masses of double-mode RR Lyrae stars are 0.1-0.2 solar mass larger than those based on earlier opacities. Unlike the pulsation calculations, we find that the effect of opacity change on the evolution of HB stars is not significant. In particular, the effect of the mean masses of RR Lyrae stars is very small, showing a decrease of only 0.01-0.02 solar mass compared to the models based on old Cox-Stewart opacities. Consequently, with the new Livermore OPAL opacities, both the stellar pulsation and evolution models now predict approximately the same masses for the RR Lyrae stars. Our evolutionary models suggest that the mean masses of the RR Lyrae stars are about 0.76 and about 0.71 solar mass for M15 (Oosterhoff group II) and M3 (group I), respectively. If (alpha/Fe) = 0.4, these values are decreased by about 0.03 solar mass. Variations of the mean masses of RR Lyrae stars with HB morphology and metallicity are also presented.

  16. Comparison of Fe and Ni opacity calculations for a better understanding of pulsating stellar envelopes

    International Nuclear Information System (INIS)

    Gilles, D.; Turck-Chieze, S.; Loisel, G.; Piau, L.; Ducret, J.E.; Poirier, M.; Blenski, T.; Thais, F.; Blancard, C.; Cosse, P.; Faussurier, G.; Gilleron, F.; Pain, J.C.; Porcherot, Q.; Guzik, J.A.; Kilcrease, D.P.; Magee, N.H.; Harris, J.; Busquet, M.; Delahaye, F.; Zeippen, C.J.; Bastiani-Ceccotti, S.

    2011-01-01

    Opacity is an important ingredient of the evolution of stars. The calculation of opacity coefficients is complicated by the fact that the plasma contains partially ionized heavy ions that contribute to opacity dominated by H and He. Up to now, the astrophysical community has greatly benefited from the work of the contributions of Los Alamos, Livermore and the Opacity Project (OP). However unexplained differences of up to 50% in the radiative forces and Rosseland mean values for Fe have been noticed for conditions corresponding to stellar envelopes. Such uncertainty has a real impact on the understanding of pulsating stellar envelopes, on the excitation of modes, and on the identification of the mode frequencies. Temperature and density conditions equivalent to those found in stars can now be produced in laboratory experiments for various atomic species. Recently the photo-absorption spectra of nickel and iron plasmas have been measured during the LULI 2010 campaign, for temperatures between 15 and 40 eV and densities of similar to 3 mg/cm 3 . A large theoretical collaboration, the 'OPAC', has been formed to prepare these experiments. We present here the set of opacity calculations performed by eight different groups for conditions relevant to the LULI 2010 experiment and to astrophysical stellar envelope conditions. (authors)

  17. Development on the National Ignition Facility of a High Energy Density Opacity Platform

    Energy Technology Data Exchange (ETDEWEB)

    Perry, Theodore Sonne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dodd, Evan S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); DeVolder, Barbara Gloria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Johns, Heather Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cardenas, Tana [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Archuleta, Thomas Nick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kline, John L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Flippo, Kirk Adler [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vinyard, Natalia Sergeevna [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sherrill, Manolo Edgar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilde, Bernhard Heinz [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tregillis, Ian Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Douglas, Melissa Rae [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Heeter, R. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Liedahl, D. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wilson, B. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Iglesias, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schneider, M. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martin, M. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); London, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ahmed, M. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thompson, N. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Emig, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zika, M. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Opachich, Y. P. [Nevada National Security Site (NNSS), NV (United States); King, J. A. [Nevada National Security Site (NNSS), NV (United States); Ross, P. W. [Nevada National Security Site (NNSS), NV (United States); Huffman, E. J. [Nevada National Security Site (NNSS), NV (United States); Knight, R. A. [Nevada National Security Site (NNSS), NV (United States); Koch, J. A. [Nevada National Security Site (NNSS), NV (United States); Pond, T. D. [Nevada National Security Site (NNSS), NV (United States); Craxton, R. S. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Zhang, R. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; McKenty, P. W. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Garcia, E. M. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Bailey, J. E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rochau, G. A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hansen, S. B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-02

    X-ray opacity is a crucial factor in all radiation-hydrodynamics calculations, yet it is one of the least validated of the material properties in simulation codes for high-energy-density plasmas. Recent opacity experiments at the Sandia Z-machine have shown up to factors of two discrepancies between theory and experiment for various mid-Z elements (Fe, Cr, Ni). These discrepancies raise doubts regarding the accuracy of the opacity models which are used in ICF and stewardship as well as in astrophysics. Therefore, a new experimental opacity platform has been developed on the National Ignition Facility (NIF), not only to verify the Z-machine experimental results, but also to extend the experiments to other temperatures and densities. Within the context of the national opacity strategy, the first NIF experiments were directed towards measuring the opacity of iron at a temperature of ~160 eV and an electron density of ~7xl021 cm-3(Anchor 1). The Z data agree with theory at these conditions, providing a reference point for validation of the NIF platform. Development shots on NIF have demonstrated the ability to create a sufficiently bright point backlighter using an imploding plastic capsule, and also a combined hohlraum, sample and laser drive able to produce iron plasmas at the desired conditions. Spectrometer qualification has been completed, albeit with additional improvements planned, and the first iron absorption spectra have now been obtained.

  18. Functional characterization of antibodies against Neisseria gonorrhoeae opacity protein loops.

    Directory of Open Access Journals (Sweden)

    Jessica G Cole

    2009-12-01

    Full Text Available The development of a gonorrhea vaccine is challenged by the lack of correlates of protection. The antigenically variable neisserial opacity (Opa proteins are expressed during infection and have a semivariable (SV and highly conserved (4L loop that could be targeted in a vaccine. Here we compared antibodies to linear (Ab(linear and cyclic (Ab(cyclic peptides that correspond to the SV and 4L loops and selected hypervariable (HV(2 loops for surface-binding and protective activity in vitro and in vivo.Ab(SV cyclic bound a greater number of different Opa variants than Ab(SV linear, including variants that differed by seven amino acids. Antibodies to the 4L peptide did not bind Opa-expressing bacteria. Ab(SV (cyclic and Ab(HV2 (cyclic, but not Ab(SV (linear or Ab(HV2 linear agglutinated homologous Opa variants, and Ab(HV2BD (cyclic but not Ab(HV2BD (linear blocked the association of OpaB variants with human endocervical cells. Only Ab(HV2BD (linear were bactericidal against the serum resistant parent strain. Consistent with host restrictions in the complement cascade, the bactericidal activity of Ab(HV2BD (linear was increased 8-fold when rabbit complement was used. None of the antibodies was protective when administered vaginally to mice. Antibody duration in the vagina was short-lived, however, with <50% of the antibodies recovered 3 hrs post-administration.We conclude that an SV loop-specific cyclic peptide can be used to induce antibodies that recognize a broad spectrum of antigenically distinct Opa variants and have agglutination abilities. HV(2 loop-specific cyclic peptides elicited antibodies with agglutination and adherence blocking abilities. The use of human complement when testing the bactericidal activity of vaccine-induced antibodies against serum resistant gonococci is also important.

  19. Glass: Rotary Electric Glass Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Recca, L.

    1999-01-29

    Compared to conventional gas-fired furnaces, the new rotary electric furnace will increase energy efficiency while significantly reducing air emissions, product turnaround time, and labor costs. As this informative new fact sheet explains, the thousand different types of glass optical blanks produced for the photonics industry are used for lasers, telescopes, cameras, lights, and many other products.

  20. OPACs en Web: entre la tradición y la innovación = OPACs on the Web: Between tradition and innovation

    Directory of Open Access Journals (Sweden)

    Purificación Moscoso

    2002-06-01

    Full Text Available El desarrollo de Internet ha impulsado la implementación de OPACs en este entorno. Se analizan los cambios que estos nuevos OPACs suponen en cuanto a: estructura, gestión y mantenimiento del catálogo; sistemas de recuperación e interfaz del usuario. La pervivencia de prácticas tradicionales en la estructura y organización de la información impide que se les considere una herramienta innovadora. Se estudia la estructura de la base de datos, así como los principios tradicionales que rigen su elaboración. Se analizan las repercusiones que lleva consigo seguir utilizando reglas y formatos diseñados para un entorno manual que nada tiene que ver con el nuevo entorno tecnológico en el que hoy en día nos movemos = Internet development has driven the implementation of OPACs in that environment. Changes of these new OPACs as referred to catalog structure, management, and maintenance, retrieval systems and user interface are analyzed. The survival of traditional practices in the information structure and organization avoids them to be considered an innovative tool. The database structure is studied as well as the traditional principles that govern their elaboration. Effects of keeping using rules and formats designed for a manual environment, which is absolutely different from the present day technological environment are analyzed.

  1. OPACs en Web: entre la tradición y la innovación OPACs on the Web: Between tradition and innovation

    Directory of Open Access Journals (Sweden)

    Purificación Moscoso

    2002-06-01

    Full Text Available El desarrollo de Internet ha impulsado la implementación de OPACs en este entorno. Se analizan los cambios que estos nuevos OPACs suponen en cuanto a: estructura, gestión y mantenimiento del catálogo; sistemas de recuperación e interfaz del usuario. La pervivencia de prácticas tradicionales en la estructura y organización de la información impide que se les considere una herramienta innovadora. Se estudia la estructura de la base de datos, así como los principios tradicionales que rigen su elaboración. Se analizan las repercusiones que lleva consigo seguir utilizando reglas y formatos diseñados para un entorno manual que nada tiene que ver con el nuevo entorno tecnológico en el que hoy en día nos movemos.Internet development has driven the implementation of OPACs in that environment. Changes of these new OPACs as referred to catalog structure, management, and maintenance, retrieval systems and user interface are analyzed. The survival of traditional practices in the information structure and organization avoids them to be considered an innovative tool. The database structure is studied as well as the traditional principles that govern their elaboration. Effects of keeping using rules and formats designed for a manual environment, which is absolutely different from the present day technological environment are analyzed.

  2. Nitrate glass

    International Nuclear Information System (INIS)

    Kirilenko, I.A.; Vinogradov, E.E.

    1977-01-01

    Experimental evidence on behaviour of nitrate glasses is reviewed in terms of relationships between the presence of water in vitrescent nitrate systems and the properties of the systems. The glasses considered belong to systems of Mg(NO 3 ) 2 - Nd(NO 3 ) 3 ; Hg(NO 3 ) 2 -Nd(NO 3 ) 3 ; NaNO 3 -Mg(NO 3 ) 2 -Nd(NO 3 ) 3 ; M-Zn(NO 3 ) 3 , where M is a mixture of 20% mass NaNO 3 and 80% mass Mg(NO 3 ) 2 , and Zn is a rare earth ion. Nitrate glass is shown to be a product of dehydration. Vitrification may be regarded as a resusl of formation of molecular complexes in the chain due to hydrogen bonds of two types, i.e. water-water, or water-nicrate group. Chain formation, along with low melting points of the nitrates, hinder crystallization of nitrate melts. Provided there is enough water, this results in vitrification

  3. IRON OPACITY BUMP CHANGES THE STABILITY AND STRUCTURE OF ACCRETION DISKS IN ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yan-Fei [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Davis, Shane W. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Stone, James M. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2016-08-10

    Accretion disks around supermassive black holes have regions where the Rosseland mean opacity can be larger than the electron scattering opacity due to the large number of bound–bound transitions in iron. We study the effects of this iron opacity “bump” on the thermal stability and vertical structure of radiation-pressure-dominated accretion disks, utilizing three-dimensional radiation magnetohydrodynamic (MHD) simulations in the local shearing box approximation. The simulations self-consistently calculate the heating due to MHD turbulence caused by magneto-rotational instability and radiative cooling by using the radiative transfer module based on a variable Eddington tensor in Athena. For a 5 × 10{sup 8} solar mass black hole with ∼3% of the Eddington luminosity, a model including the iron opacity bump maintains its structure for more than 10 thermal times without showing significant signs of thermal runaway. In contrast, if only electron scattering and free–free opacity are included as in the standard thin disk model, the disk collapses on the thermal timescale. The difference is caused by a combination of (1) an anti-correlation between the total optical depth and the midplane pressure, and (2) enhanced vertical advective energy transport. These results suggest that the iron opacity bump may have a strong impact on the stability and structure of active galactic nucleus (AGN) accretion disks, and may contribute to a dependence of AGN properties on metallicity. Since this opacity is relevant primarily in UV emitting regions of the flow, it may help to explain discrepancies between observation and theory that are unique to AGNs.

  4. The influence of urban area opacity on biologically active UV-B irradiance

    Science.gov (United States)

    Chubarova, Nataly; Rozental', Victor

    2013-04-01

    The study of UV irradiance changes in urban area is an essential problem due to the significant effect of UV irradiance on human health which can be positive (vitamin D synthesis) and negative (erythema, skin cancer, eye damage). According to the results of several experiments within the Moscow megacity we studied the effects of urban area opacity on the different types of biologically active UV-B irradiance on the base of a specially developed mobile photometric complex snd additional measurements of the urban opacity by Nikon Fisheye Converter FC-E8. We analyzed both the level of erythemally-active irradiance and the UV eye damaging radiation using the broadband UVB-1 YES pyranometer calibrated against ultraviolet spectroradiometer Bentham DTM-300 of the Medical University of Innsbruck (courtesy of Dr. M.Blumthaler). In order to estimate the effects of the urban opacity the measurements were normalized on similar measurements at the Meteorological Observatory of Moscow State University with zero opacity. This ratio is defined as an urban radiative transmittance (URT). Different atmospheric conditions were considered. In cloudy conditions the effect of opacity on URT is much less than that in conditions when the sun disk is open from clouds. We revealed some spectral features in transmittance of biologically active UV-B irradiance which is characterized by higher URT variations in overcast cloudy conditions due to more intensive scattering and smaller direct solar radiation component. In the absence of cloudiness the effect of opacity was studied for open and screening solar disk conditions. We obtained much higher URT in UVB spectral region compared with that for total solar irradiance for screening solar disk conditions with a significant URT dependence on the opacity only in UVB spectral region. No URT dependence was obtained for total solar irradiance in these conditions. Some model calculations were fulfilled to match the experimental results.

  5. Natural analogue study of volcanic glass

    International Nuclear Information System (INIS)

    Arai, T.; Yusa, Y.; Sasaki, N.; Tsunoda, N.; Takano, H.

    1989-02-01

    A considerable range in alteration rates of basaltic glasses in various environments has been reported in previous studies. However, these studies paid only cursory attention to the environmental conditions under which the glass had been altered. In this study, the alteration of basaltic glasses was investigated and the environmental conditions and the alteration rate were discussed. Two sample ages were represented: 280 years and 2800 years. Basaltic glasses and their alteration layers were analyzed by electron probe microanalyzer (EMPA) and the thickness of the alteration layers were measured by scanning electron microscope (SEM). The ground water collected near the sampling point of Zunazawa Scoria (2800 years) and the pore water of both samples were analyzed. The alteration temperature and flow rate of water are estimated to be about 13degC and 0.2 l/cm 2 /y respectively on the basis of meteorological data. The alteration layers of young aged basaltic glasses in freshwater conditions are similar to those of leached borosilicate glasses. The alteration rates of these basaltic glasses are estimated to be several μm/1000y. The elemental concentrations in the ground water can be roughly explained as the result of leaching of the glasses. (author)

  6. Presenting a model for display and user interface specifications of web based OPACs on the basis of available universal standards and experts views in order to compare the Iranian library and information centers OPACs

    OpenAIRE

    Zavaraqi, Rasoul

    2005-01-01

    The aim of this study is to present a model for display and user interface specifications of web-based OPACs on the basis of available universal standards and experts’ views in order to compare the present Iranian library and information centers OPACs. Three method were used for data collection in this research: literature review, survey of opinions by means of a checklist, and evaluation of the available web-based OPACs. The community of Iranian experts in OPAC issues and all of 6 available ...

  7. Night and Day: The Opacity of Clouds Measured by the Mars Orbiter Laser Altimeter (MOLA)

    Science.gov (United States)

    Neumann, G. A.; Wilson, R. J.

    2006-01-01

    The Mars Orbiter Laser Altimeter (MOLA) [l] on the Mars Global Surveyor spacecraft ranged to clouds over the course of nearly two Mars years [2] using an active laser ranging system. While ranging to the surface, the instrument was also able to measure the product of the surface reflectivity with the two-way atmospheric transmission at 1064 nm. Furthermore, the reflectivity has now been mapped over seasonal cycles using the passive radiometric capability built into MOLA [3]. Combining these measurements, the column opacity may be inferred. MOLA uniquely provides these measurements both night and day. This study examines the pronounced nighttime opacity of the aphelion season tropical water ice clouds, and the indiscernibly low opacity of the southern polar winter clouds. The water ice clouds (Figure 1) do not themselves trigger the altimeter but have measured opacities tau > 1.5 and are temporally and spatially correlated with temperature anomalies predicted by a Mars Global Circulation Model (MGCM) that incorporates cloud radiative effects [4]. The south polar CO2 ice clouds trigger the altimeter with a very high backscatter cross-section over a thickness of 3-9 m and are vertically dispersed over several km, but their total column opacities lie well below the MOLA measurement limit of tau = 0.7. These clouds correspond to regions of supercooled atmosphere that may form either very large specularly reflecting particles [2] or very compact, dense concentrations (>5x10(exp 6)/cu m) of 100-p particles

  8. Iron and Nickel spectral opacity calculations in conditions relevant for pulsating stellar envelopes and experiments

    International Nuclear Information System (INIS)

    Gilles, D.; Turck-Chieze, S.; Busquet, M.; Thais, F.; Loisel, G.; Piau, L.; Ducret, J. E.; Blenski, T.; Blancard, C.; Cosse, P.; Faussurier, G.; Gilleron, F.; Pain, J. C.; Porcherot, Q.; Guzik, J. A.; Kilcrease, D. P.; Magee, N. H.; Harris, J.; Bastiani-Ceccotti, S.; Delahaye, F.; Zeippen, C. J.

    2013-01-01

    Seismology of stars is strongly developing. To address this question we have formed an international collaboration, OPAC, to perform specific experimental measurements, compare opacity calculations, and improve the opacity calculations in stellar codes [1]. We consider the following opacity codes: SCO, CASSANDRA, STA, OPAS, LEDCOP, OP, SCO-RCG. Their comparison has shown large differences for Fe and Ni in equivalent conditions of envelopes of type II supernova precursors, temperatures between 15 and 40 eV and densities of a few mg/cm 3 [2-4]. LEDCOP, OPAS, SCO-RCG structure codes and STA give similar results and differ from OP ones for the lower temperatures and for spectral interval values [3]. In this work we discuss the role of Configuration Interaction (CI) and the influence of the number of used configurations. We present and include in the opacity code comparisons new HULLAC-v9 calculations [5, 6] that include full CI. To illustrate the importance of this effect we compare different CI approximations (modes) available in HULLAC-v9 [7]. These results are compared to previous predictions and to experimental data. Differences with OP results are discussed. (authors)

  9. Recent status and supplementary review of lenticular opacities in proximally exposed A-bomb survivors

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, S [Sugimoto Ophthalmic Hospital, Hiroshima (Japan)

    1978-04-01

    A review was made on the progress of lenticular opacities in proximally exposed A-bomb survivors on the basis of three experimental cases. A-bomb cataract is the first late effect of A-bomb radiation which appeared in A-bomb survivors and is the only disorder which can still be visualized at the present time. We have therefore continued to use this as one major evidence that A-bomb injuries have not been cured in spite of our for a complete ban of nuclear weapons. According to the findings of lenticular opacities of typical A-bomb cataract observed in experimental cases, there was in some cases after a latent period progression of opacities from several years to more than 10 years followed by a gradual decrease in opacities, whereas in some cases there was after a latent period a remarkable progress in opacities for several years followed by a marked decrease in the lesions. At the present time there is no evidence of progression and it appears that the progression has ceased. Incipient senile cataract which developed concurrently has completely no transitional relationship to A-bomb cataract and appears to progress slowly but steadily.

  10. Recent status and supplementary review of lenticular opacities in proximally exposed A-bomb survivors

    International Nuclear Information System (INIS)

    Sugimoto, Shigenori

    1978-01-01

    A review was made on the progress of lenticular opacities in proximally exposed A-bomb survivors on the basis of three experimental cases. A-bomb cataract is the first late effect of A-bomb radiation which appeared in A-bomb survivors and is the only disorder which can still be visualized at the present time. We have therefore continued to use this as one major evidence that A-bomb injuries have not been cured in spite of our for a complete ban of nuclear weapons. According to the findings of lenticular opacities of typical A-bomb cataract observed in experimental cases, there was in some cases after a latent period progression of opacities from several years to more than 10 years followed by a gradual decrease in opacities, whereas in some cases there was after a latent period a remarkable progress in opacities for several years followed by a marked decrease in the lesions. At the present time there is no evidence of progression and it appears that the progression has ceased. Incipient senile cataract which developed concurrently has completely no transitional relationship to A-bomb cataract and appears to progress slowly but steadily. (auth.)

  11. Mid-infrared mapping of Jupiter's temperatures, aerosol opacity and chemical distributions with IRTF/TEXES

    Science.gov (United States)

    Fletcher, Leigh N.; Greathouse, T. K.; Orton, G. S.; Sinclair, J. A.; Giles, R. S.; Irwin, P. G. J.; Encrenaz, T.

    2016-11-01

    Global maps of Jupiter's atmospheric temperatures, gaseous composition and aerosol opacity are derived from a programme of 5-20 μm mid-infrared spectroscopic observations using the Texas Echelon Cross Echelle Spectrograph (TEXES) on NASA's Infrared Telescope Facility (IRTF). Image cubes from December 2014 in eight spectral channels, with spectral resolutions of R ∼2000 - 12 , 000 and spatial resolutions of 2-4° latitude, are inverted to generate 3D maps of tropospheric and stratospheric temperatures, 2D maps of upper tropospheric aerosols, phosphine and ammonia, and 2D maps of stratospheric ethane and acetylene. The results are compared to a re-analysis of Cassini Composite Infrared Spectrometer (CIRS) observations acquired during Cassini's closest approach to Jupiter in December 2000, demonstrating that this new archive of ground-based mapping spectroscopy can match and surpass the quality of previous investigations, and will permit future studies of Jupiter's evolving atmosphere. The visibility of cool zones and warm belts varies from channel to channel, suggesting complex vertical variations from the radiatively-controlled upper troposphere to the convective mid-troposphere. We identify mid-infrared signatures of Jupiter's 5-μm hotspots via simultaneous M, N and Q-band observations, which are interpreted as temperature and ammonia variations in the northern Equatorial Zone and on the edge of the North Equatorial Belt (NEB). Equatorial plumes enriched in NH3 gas are located south-east of NH3-desiccated 'hotspots' on the edge of the NEB. Comparison of the hotspot locations in several channels across the 5-20 μm range indicate that these anomalous regions tilt westward with altitude. Aerosols and PH3 are both enriched at the equator but are not co-located with the NH3 plumes. The equatorial temperature minimum and PH3/aerosol maxima have varied in amplitude over time, possibly as a result of periodic equatorial brightenings and the fresh updrafts of

  12. Portfolios with nonlinear constraints and spin glasses

    Science.gov (United States)

    Gábor, Adrienn; Kondor, I.

    1999-12-01

    In a recent paper Galluccio, Bouchaud and Potters demonstrated that a certain portfolio problem with a nonlinear constraint maps exactly onto finding the ground states of a long-range spin glass, with the concomitant nonuniqueness and instability of the optimal portfolios. Here we put forward geometric arguments that lead to qualitatively similar conclusions, without recourse to the methods of spin glass theory, and give two more examples of portfolio problems with convex nonlinear constraints.

  13. The solar elemental abundances problem: Large enhancements in photoionization and bound-free opacity

    Science.gov (United States)

    Pradhan, A.; Nahar, S.

    2016-05-01

    Aimed at solving the outstanding problem of solar opacity and radiation transport, we report substantial photoabsorption in the high-energy regime due to atomic core photo-excitations not heretofore considered. In an extensive R-Matrix calculations of unprecedented complexity for an important iron ion Fe XVII, with a wave function expansion of 99 Fe XVIII core states from n current opacity models, and ii) demonstrate convergence with respect to successive core excitations. These findings may explain the ``higher-than-predicted'' monochromatic iron opacity measured recently at the Sandia Z-pinch fusion device at solar interior conditions. The findings will also impact the total atomic photoabsorption and radiation transport in laboratory and astrophysical plasmas, such as UV emission from host stars of extra-solar planets. Support: NSF, DOE, Ohio Supercomputer Center, Columbus, OH.

  14. Constraints on cosmic opacity and beyond the standard model physics from cosmological distance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Avgoustidis, Anastasios [Centre for Theoretical Cosmology, DAMTP, CMS, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Burrage, Clare [Deutsches Elektronen Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Redondo, Javier [Max Planck Institut für Physik, Föhringer Ring 6, D-80805, Munich (Germany); Verde, Licia; Jimenez, Raul, E-mail: a.avgoustidis@damtp.cam.ac.uk, E-mail: clare.burrage@desy.de, E-mail: redondo@mppmu.mpg.de, E-mail: liciaverde@icc.ub.edu, E-mail: raul.jimenez@icc.ub.edu [ICREA and Institute for Sciences of the Cosmos (ICC), University of Barcelona, IEEC, Barcelona 08028 (Spain)

    2010-10-01

    We update constraints on cosmic opacity by combining recent SN Type Ia data with the latest measurements of the Hubble expansion at redshifts between 0 and 2. The new constraint on the parameter ε parametrising deviations from the luminosity-angular diameter distance relation (d{sub L} = d{sub A}(1+z){sup 2+ε}), is ε = −0.04{sub −0.07}{sup +0.08} (2-σ). For the redshift range between 0.2 and 0.35 this corresponds to an opacity Δτ < 0.012 (95% C.L.), a factor of 2 stronger than the previous constraint. Various models of beyond the standard model physics that predict violation of photon number conservation contribute to the opacity and can be equally constrained. In this paper we put new limits on axion-like particles, including chameleons, and mini-charged particles.

  15. Constraints on cosmic opacity and beyond the standard model physics from cosmological distance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Avgoustidis, Anastasios [DAMTP, CMS, Cambridge (United Kingdom). Centre for Theoretical Cosmology; Burrage, Clare [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Redondo, Javier [Max-Planck-Institut fuer Physik, Munich (Germany); Verde, Licia; Jimenez, Raul [Barcelona Univ., IEEC (ES). ICREA and Inst. for Sciences of the Cosmos (ICC)

    2010-04-15

    We update constraints on cosmic opacity by combining recent SN Type Ia data compilation with the latest measurements of the Hubble expansion at redshifts between 0 and 2. The new constraint on the parameter {epsilon} parametrising deviations from the luminosity-angular diameter distance relation (d{sub L}=d{sub A}(1+z){sup 2+{epsilon}}), is {epsilon}=-0.04{sub -0.07}{sup +0.08} (2-{sigma}). For the redshift range between 0.2 and 0.35 this corresponds to an opacity {delta}{tau}<0.012 (95% C.L.), a factor of 2 stronger than the previous constraint. Various models of beyond the standard model physics that predict violation of photon number conservation contribute to the opacity and can be equally constrained. In this paper we put new limits on axion-like particles, including chameleons, and minicharged particles. (orig.)

  16. Constraints on cosmic opacity and beyond the standard model physics from cosmological distance measurements

    International Nuclear Information System (INIS)

    Avgoustidis, Anastasios; Redondo, Javier; Verde, Licia; Jimenez, Raul

    2010-04-01

    We update constraints on cosmic opacity by combining recent SN Type Ia data compilation with the latest measurements of the Hubble expansion at redshifts between 0 and 2. The new constraint on the parameter ε parametrising deviations from the luminosity-angular diameter distance relation (d L =d A (1+z) 2+ε ), is ε=-0.04 -0.07 +0.08 (2-σ). For the redshift range between 0.2 and 0.35 this corresponds to an opacity Δτ<0.012 (95% C.L.), a factor of 2 stronger than the previous constraint. Various models of beyond the standard model physics that predict violation of photon number conservation contribute to the opacity and can be equally constrained. In this paper we put new limits on axion-like particles, including chameleons, and minicharged particles. (orig.)

  17. OPAC Design Enhancements and Their Effects on Circulation and Resource Sharing within the Library Consortium Environment

    Directory of Open Access Journals (Sweden)

    Michael J. Bennett

    2007-03-01

    Full Text Available A longitudinal study of three discrete online public access catalog (OPAC design enhancements examined the possible effects such changes may have on circulation and resource sharing within the automated library consortium environment. Statistical comparisons were made of both circulation and interlibrary loan (ILL figures from the year before enhancement to the year after implementation. Data from sixteen libraries covering a seven-year period were studied in order to determine the degree to which patrons may or may not utilize increasingly broader OPAC ILL options over time. Results indicated that while ILL totals increased significantly after each OPAC enhancement, such gains did not result in significant corresponding changes in total circulation.

  18. Opacity measurements of tamped NaBr samples heated by z-pinch X-rays

    International Nuclear Information System (INIS)

    Bailey, J.E.; Arnault, P.; Blenski, T.; Dejonghe, G.; Peyrusse, O.; MacFarlane, J.J.; Mancini, R.C.; Cuneo, M.E.; Nielsen, D.S.; Rochau, G.A.

    2003-01-01

    Laboratory measurements provide benchmark data for wavelength-dependent plasma opacities to assist inertial confinement fusion, astrophysics, and atomic physics research. There are several potential benefits to using z-pinch radiation for opacity measurements, including relatively large cm-scale lateral sample sizes and relatively-long 3-5 ns experiment durations. These features enhance sample uniformity. The spectrally resolved transmission through a CH-tamped NaBr foil was measured. The z-pinch produced the X-rays for both the heating source and backlight source. The (50±4) eV foil electron temperature and (3±1)x10 21 cm -3 foil electron density were determined by analysis of the Na absorption features. LTE and NLTE opacity model calculations of the n=2 to 3, 4 transitions in bromine ionized into the M-shell are in reasonably good agreement with the data

  19. Smoke opacity in agricultural tractor in function of interior and metropolitano diesel mixture in mamona biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Tabile, Rubens Andre [Universidade de Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). Escola de Engenharia; Lopes, Afonso; Camara, Felipe Thomas da; Grotta, Danilo Cesar Checchio; Furlani, Carlos Eduardo Angeli [Universidade Estadual Paulista (DER/UNESP), Jaboticabal, SP (Brazil). Dept. de Engenharia Rural

    2008-07-01

    The great demand for energy sources by production systems allied to scarcity of fossil fuels has motivated the development and production of biodiesel, which is a fuel produced from renewable sources. Given that, the aim of this study was to compare smoke opacity of an agricultural tractor engine, working with metropolitano and interior diesel mixed to mamona biodiesel, in seven proportions. The tests were conducted in the Departamento de Engenharia Rural of UNESP/Jaboticabal - SP. The results showed that the diesel type did influence opacity of smoke, and metropolitano diesel showed best quality. It was also observed that, as biodiesel proportion increased, smoke opacity decreased until B75, turning to increase to B100. (author)

  20. Modelling aqueous corrosion of nuclear waste phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Poluektov, Pavel P.; Schmidt, Olga V.; Kascheev, Vladimir A. [Bochvar All-Russian Scientific Research Institute for Inorganic Materials (VNIINM), Moscow (Russian Federation); Ojovan, Michael I., E-mail: m.ojovan@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)

    2017-02-15

    A model is presented on nuclear sodium alumina phosphate (NAP) glass aqueous corrosion accounting for dissolution of radioactive glass and formation of corrosion products surface layer on the glass contacting ground water of a disposal environment. Modelling is used to process available experimental data demonstrating the generic inhibiting role of corrosion products on the NAP glass surface. - Highlights: • The radionuclides yield is determined by the transport from the glass through the surface corrosion layer. • Formation of the surface layer is due to the dissolution of the glass network and the formation of insoluble compounds. • The model proposed accounts for glass dissolution, formation of corrosion layer, specie diffusion and chemical reactions. • Analytical solutions are found for corrosion layer growth rate and glass components component leaching rates.

  1. Crystallization of Na2O-SiO2 gel and glass

    Science.gov (United States)

    Neilson, G. F.; Weinberg, M. C.

    1984-01-01

    The crystallization behavior of a 19 wt pct soda silica gel and gel-derived glass was compared to that of the ordinary glass of the same composition. Both bulk and ground glass samples were utilized. X-ray diffraction measurements were made to identify the crystalline phases and gauge the extent of crystallization. It was found that the gel crystallized in a distinctive manner, while the gel glass behavior was not qualitatively different from that of the ordinary glass.

  2. Opacity and atomic analysis of double pulse laser ablated Li plasma

    Science.gov (United States)

    Sivakumaran, V.; Joshi, H. C.; Kumar, Ajai

    2014-09-01

    Opacity effects for neutral and ionic emission lines of lithium have been investigated by Atomic Data Analysis Structure (ADAS). Line ratios and opacity corrected photon emissivity coefficients are calculated over a wide range of electron temperatures and densities. The experimentally measured temporal evolution of the line profiles of the over dense Li plasma formed in the double pulse laser ablation experiment have been explained using the ADAS analysis and the plasma parameters of the plasma plume under consideration have been estimated. These results could be projected as a diagnostic tool to estimate plasma parameters of an over dense lithium plasma.

  3. CRYSTALLIZATION IN MULTICOMPONENT GLASSES

    Energy Technology Data Exchange (ETDEWEB)

    KRUGER AA; HRMA PR

    2009-10-08

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  4. Crystallization In Multicomponent Glasses

    International Nuclear Information System (INIS)

    Kruger, A.A.; Hrma, P.R.

    2009-01-01

    In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may settle at the melter bottom. Within the body of cooling glass, multiple phases crystallize in a non-uniform time-dependent temperature field. Self-organizing periodic distribution (the Liesegnang effect) is common. Various crystallization phenomena that occur in glass making are reviewed.

  5. NASA study of cataract in astronauts (NASCA). Report 1: Cross-sectional study of the relationship of exposure to space radiation and risk of lens opacity.

    Science.gov (United States)

    Chylack, Leo T; Peterson, Leif E; Feiveson, Alan H; Wear, Mary L; Manuel, F Keith; Tung, William H; Hardy, Dale S; Marak, Lisa J; Cucinotta, Francis A

    2009-07-01

    The NASA Study of Cataract in Astronauts (NASCA) is a 5-year longitudinal study of the effect of space radiation exposure on the severity/progression of nuclear, cortical and posterior subcapsular (PSC) lens opacities. Here we report on baseline data that will be used over the course of the longitudinal study. Participants include 171 consenting astronauts who flew at least one mission in space and a comparison group made up of three components: (a) 53 astronauts who had not flown in space, (b) 95 military aircrew personnel, and (c) 99 non-aircrew ground-based comparison subjects. Continuous measures of nuclear, cortical and PSC lens opacities were derived from Nidek EAS 1000 digitized images. Age, demographics, general health, nutritional intake and solar ocular exposure were measured at baseline. Astronauts who flew at least one mission were matched to comparison subjects using propensity scores based on demographic characteristics and medical history stratified by gender and smoking (ever/never). The cross-sectional data for matched subjects were analyzed by fitting customized non-normal regression models to examine the effect of space radiation on each measure of opacity. The variability and median of cortical cataracts were significantly higher for exposed astronauts than for nonexposed astronauts and comparison subjects with similar ages (P=0.015). Galactic cosmic space radiation (GCR) may be linked to increased PSC area (P=0.056) and the number of PSC centers (P=0.095). Within the astronaut group, PSC size was greater in subjects with higher space radiation doses (P=0.016). No association was found between space radiation and nuclear cataracts. Cross-sectional data analysis revealed a small deleterious effect of space radiation for cortical cataracts and possibly for PSC cataracts. These results suggest increased cataract risks at smaller radiation doses than have been reported previously.

  6. Recycling of Glass

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Damgaard, Anders

    2011-01-01

    Glass is used for many purposes, but in the waste system glass is predominantly found in terms of beverage and food containers with a relatively short lifetime before ending up in the waste. Furthermore there is a large amount of flat glass used in building materials which also ends up in the waste...... system; this glass though has a long lifetime before ending up in the waste. Altogether these product types add up to 82% of the production of the European glass industry (IPCC, 2001). Recycling of glass in terms of cleaning and refilling of bottles as well as the use of broken glass in the production...... of new glass containers is well established in the glass industry. This chapter describes briefly howglass is produced and howwaste glass is recycled in the industry. Quality requirements and use of recycled products are discussed, as are the resource and environmental issues of glass recycling....

  7. Open-Source Tools for Enhancing Full-Text Searching of OPACs: Use of Koha, Greenstone and Fedora

    Science.gov (United States)

    Anuradha, K. T.; Sivakaminathan, R.; Kumar, P. Arun

    2011-01-01

    Purpose: There are many library automation packages available as open-source software, comprising two modules: staff-client module and online public access catalogue (OPAC). Although the OPAC of these library automation packages provides advanced features of searching and retrieval of bibliographic records, none of them facilitate full-text…

  8. CLAY SOIL STABILISATION USING POWDERED GLASS

    Directory of Open Access Journals (Sweden)

    J. OLUFOWOBI

    2014-10-01

    Full Text Available This paper assesses the stabilizing effect of powdered glass on clay soil. Broken waste glass was collected and ground into powder form suitable for addition to the clay soil in varying proportions namely 1%, 2%, 5%, 10% and 15% along with 15% cement (base by weight of the soil sample throughout. Consequently, the moisture content, specific gravity, particle size distribution and Atterberg limits tests were carried out to classify the soil using the ASSHTO classification system. Based on the results, the soil sample obtained corresponded to Group A-6 soils identified as ‘fair to poor’ soil type in terms of use as drainage and subgrade material. This justified stabilisation of the soil. Thereafter, compaction, California bearing ratio (CBR and direct shear tests were carried out on the soil with and without the addition of the powdered glass. The results showed improvement in the maximum dry density values on addition of the powdered glass and with corresponding gradual increase up to 5% glass powder content after which it started to decrease at 10% and 15% powdered glass content. The highest CBR values of 14.90% and 112.91% were obtained at 5% glass powder content and 5mm penetration for both the unsoaked and soaked treated samples respectively. The maximum cohesion and angle of internal friction values of 17.0 and 15.0 respectively were obtained at 10% glass powder content.

  9. Color and opacity of composites protected with surface sealants and submitted to artificial accelerated aging.

    Science.gov (United States)

    Aguilar, Fabiano Gamero; Roberti Garcia, Lucas da Fonseca; Cruvinel, Diogo Rodrigues; Sousa, Ana Beatriz Silva; de Carvalho Panzeri Pires-de-Souza, Fernanda

    2012-01-01

    To evaluate the color similarity, stability and opacity of composites (TPH, Charisma, and Concept, shade A2) protected with surface sealants (Fortify Plus and Biscover) and cyanoacrylate (Super Bonder). Forty specimens of each composite were made and separated into 4 groups (n=10) according to the surface protection: GI - without sealant; GII - cyanoacrylate; GIII - Fortify Plus; GIV - Biscover. Color and opacity readings were taken before and after Artificial Acelerated Aging (AAA) and the values obtained for color stability were submitted to statistical analysis by 2-way ANOVA and Bonferroni's test (P<.05). The values acquired for color similarity were submitted to 1-way ANOVA and Tukey's test (P<.05). The specimen sufaces were compared before and after AAA using Scanning Electronic Microscopy (SEM). Studied composites did not present the same values for the coordinates L*, a* and b * before AAA, indicating that there was no color similarity among them. All composites presented color alteration after AAA with clinically unacceptable values. Protected groups presented lower opacity variation after AAA, in comparison with the control goup. SEM evaluation demonstrated that AAA increased the surface irregularities in all of the studied groups. Surface sealants were not effective in maintaining composite color, but were able to maintain opacity.

  10. Opportunities for Laboratory Opacity Chemistry Studies to Facilitate Characterization of Young Giant Planets and Brown Dwarfs

    Science.gov (United States)

    Marley, Mark; Freedman, Richard S.

    2015-01-01

    The thermal emission spectra of young giant planets is shaped by the opacity of atoms and molecules residing in their atmospheres. While great strides have been made in improving the opacities of important molecules, particularly NH3 and CH4, at high temperatures, much more work is needed to understand the opacity and chemistry of atomic Na and K. The highly pressure broadened fundamental band of Na and K in the optical stretches into the near-infrared, strongly influencing the shape of the Y and K spectral bands. Since young giant planets are bright in these bands it is important to understand the influences on the spectral shape. Discerning gravity and atmospheric composition is difficult, if not impossible, without both good atomic opacities as well as an excellent understanding of the relevant atmospheric chemistry. Since Na and K condense at temperatures near 500 to 600 K, the chemistry of the condensation process must be well understood as well, particularly any disequilibrium chemical pathways. Comparisons of the current generation of sophisticated atmospheric models and available data, however, reveal important shortcomings in the models. We will review the current state of observations and theory of young giant planets and will discuss these and other specific examples where improved laboratory measurements for alkali compounds have the potential of substantially improving our understanding of these atmospheres.

  11. Important consequences of atomic diffusion inside main-sequence stars: opacities, extra-mixing, oscillations

    Directory of Open Access Journals (Sweden)

    Deal M.

    2017-01-01

    Full Text Available Atomic diffusion, including the effects of radiative accelerations on individual elements, leads to important variations of the chemical composition inside stars. The accumulation of important elements in specific layers leads to a local increase of the average opacity and to hydrodynamic instabilities that modify the internal stellar structure. This can also have important consequences for asteroseismology.

  12. Opacity of financial information, adoption of international standards and legal origins

    Directory of Open Access Journals (Sweden)

    Renata Turola Takamatsu

    2017-10-01

    Full Text Available Purpose – The goal of this study was to investigate the relationship between the level of Earnings Opacity and a company’s informational environment, specifically considering accounting standards and the legal origins of the system. Design/methodology/approach – The sample consisted of publicly traded companies from 20 countries classified as emerging, based on agency Standard & Poor’s index. The sample included data from 2004 to 2013. In order to compare the indicators among the group of countries, taking into account their institutional characteristics, the Mann-Whitney test and the Kruskal-Wallis test were performed. Findings – The assessment of the informational environment measures’ behavior in emerging countries revealed that these measures were correlated, suggesting that, despite different behaviors, opacity proxies share information. The fact that earnings opacity was lower in countries that had already adopted international standards during the analyzed period was also observed. In the same sense, a higher level of income smoothing was detected in countries of French code law origins. Originality/value – This article contributes to the understanding of the relationship between the characteristics of an accounting informational environment and the levels of opacity of the information emitted by accounting. Thus, this article has helped managers, investors and regulators to understand users’ needs and how country-specific characteristics change their perspectives.

  13. Biodegradable X-ray markers of controlled radio-opacity. Temporary position measurements in bone

    NARCIS (Netherlands)

    Stallmann, H.P.; Faber, C.; Plokker, H.M.; Wuisman, P.I.J.M.

    2005-01-01

    In order to analyze X-ray markers for potential use in biodegradable implants or radiostereogrammatic analysis (RSA), we combined iopromide contrast fluid with biodegradable calcium phosphate cement. The radio-opacity of 10 × 10 mm markers containing different iodine concentrations (0,120, 240, 360

  14. The relationship between elastomer opacity, colorimeter beam size, and measured colorimetric response.

    Science.gov (United States)

    Rugh, E H; Johnston, W M; Hesse, N S

    1991-01-01

    The effect of opacity on the colorimetric responses of large-area and small-area colorimeters was determined using an elastomer intended for maxillofacial prosthetics use and containing various pigments at different concentrations. Opacity was determined by calculating the contrast ratio of 2-mm-thick specimens against black and white backings, using Kubelka-Munk analyses to correct for thickness and backing color variations. The measure of comparison of the two colorimeters was the relative difference in tristimulus reflectance, with the tristimulus reflectance of the large-area colorimeter as the basis of the relative difference. A significant quadratic relationship was found between contrast ratio and the relative difference in tristimulus reflectance. This relationship may be used to describe opacity without the need to make optical observations or measurements of a thin layer of material on contrasting backings. The small-area colorimeter produced color parameters that are a measure of the combined effects of both color and opacity. The importance of beam size considerations of optical measuring devices for translucent natural and prosthetic materials was emphasized.

  15. 77 FR 8160 - Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary Sources

    Science.gov (United States)

    2012-02-14

    ... with the opacity measurement/reference beam(s), spectrally selective optical filters, beam splitters... Monitor Manufacturers to Certify Conformance with Design and Performance Specifications, whereas the 2003... my COMS? Necessary components of the routine system checks will depend on the design details of your...

  16. UTILITARIAN OPACITY MODEL FOR AGGREGATE PARTICLES IN PROTOPLANETARY NEBULAE AND EXOPLANET ATMOSPHERES

    International Nuclear Information System (INIS)

    Cuzzi, Jeffrey N.; Davis, Sanford S.; Estrada, Paul R.

    2014-01-01

    As small solid grains grow into larger ones in protoplanetary nebulae, or in the cloudy atmospheres of exoplanets, they generally form porous aggregates rather than solid spheres. A number of previous studies have used highly sophisticated schemes to calculate opacity models for irregular, porous particles with sizes much smaller than a wavelength. However, mere growth itself can affect the opacity of the medium in far more significant ways than the detailed compositional and/or structural differences between grain constituents once aggregate particle sizes exceed the relevant wavelengths. This physics is not new; our goal here is to provide a model that provides physical insight and is simple to use in the increasing number of protoplanetary nebula evolution and exoplanet atmosphere models appearing in recent years, yet quantitatively captures the main radiative properties of mixtures of particles of arbitrary size, porosity, and composition. The model is a simple combination of effective medium theory with small-particle closed-form expressions, combined with suitably chosen transitions to geometric optics behavior. Calculations of wavelength-dependent emission and Rosseland mean opacity are shown and compared with Mie theory. The model's fidelity is very good in all comparisons we have made except in cases involving pure metal particles or monochromatic opacities for solid particles with sizes comparable to the wavelength

  17. Impact of Internet Search Engines on OPAC Users: A Study of Punjabi University, Patiala (India)

    Science.gov (United States)

    Kumar, Shiv

    2012-01-01

    Purpose: The aim of this paper is to study the impact of internet search engine usage with special reference to OPAC searches in the Punjabi University Library, Patiala, Punjab (India). Design/methodology/approach: The primary data were collected from 352 users comprising faculty, research scholars and postgraduate students of the university. A…

  18. A clickstream data analysis of Chinese academic library OPAC users' information behavior

    NARCIS (Netherlands)

    Jiang, Tingting; Chi, Yu; Gao, Huiqin

    2017-01-01

    Chinese academic libraries have been devoting great effort into introducing next-generation online public access catalogs (OPACs) in order to provide a better user experience. However, there is a lack of empirical research on their usage. In this study, a transaction log file from a typical

  19. The Belfast atomic data bank, recommended data, and the opacity project data base

    International Nuclear Information System (INIS)

    Berrington, K.A.; Kingston, A.E.; Sawey, P.M.J.

    1991-01-01

    The Belfast Atomic Data Bank holds data for the excitation and ionisation of atoms and ions by electrons and photons, and provides recommended data; electron excitation data recommended at regular Atomic Data Workshops is summarised. Photoabsorption data for all elements up to Fe have been calculated in the international Opacity Project, and a summary is given of the atomic data expected from the Project

  20. Medical management of bilateral corneal opacity in an Asian elephant (Elephas maximus: A case report

    Directory of Open Access Journals (Sweden)

    Pranab Paul

    2018-03-01

    Full Text Available Objective: This study was aimed at studying efficacy of medical management of corneal opacity in an Asian elephant (Elephas maximus. Material and methods: A 42 years old male Asian elephant was brought to the Teaching Veterinary Hospital (TVH at Chittagong Veterinary and Animal Sciences University (CVASU with a history of chronic lacrimation and impaired vision. On clinical examination, the animal was found apparently healthy. Opthalmological examination tentatively revealed the condition as corneal opacity. The left eye was much more affected as compared to the right one. Medical management was instituted with topical administration of ciprofloxacin, dexamethasone, subconjunctival prednisolone and dexamethasone along with intramuscular ketoprofen (at 1 mg/Kg bwt and vitamin A (at 5000 IU/Kg bwt. Results: The “mahout” (elepenat caretaker of the elephant was kept in close contact over cell phone to follow up the progress of the condition. Clinical examination after 19 days revealed complete recovery of the cornel opacity. There was no sign of lacrimation and the animal regained its normal vision. Conclusion: The treatment protocol successfully eliminated the discomfort along with corneal opacity and lacrimation in an Asian elephant. [J Adv Vet Anim Res 2018; 5(1.000: 98-100

  1. Gray and multigroup radiation transport models for two-dimensional binary stochastic media using effective opacities

    International Nuclear Information System (INIS)

    Olson, Gordon L.

    2016-01-01

    One-dimensional models for the transport of radiation through binary stochastic media do not work in multi-dimensions. Authors have attempted to modify or extend the 1D models to work in multidimensions without success. Analytic one-dimensional models are successful in 1D only when assuming greatly simplified physics. State of the art theories for stochastic media radiation transport do not address multi-dimensions and temperature-dependent physics coefficients. Here, the concept of effective opacities and effective heat capacities is found to well represent the ensemble averaged transport solutions in cases with gray or multigroup temperature-dependent opacities and constant or temperature-dependent heat capacities. In every case analyzed here, effective physics coefficients fit the transport solutions over a useful range of parameter space. The transport equation is solved with the spherical harmonics method with angle orders of n=1 and 5. Although the details depend on what order of solution is used, the general results are similar, independent of angular order. - Highlights: • Gray and multigroup radiation transport is done through 2D stochastic media. • Approximate models for the mean radiation field are found for all test problems. • Effective opacities are adjusted to fit the means of stochastic media transport. • Test problems include temperature dependent opacities and heat capacities • Transport solutions are done with angle orders n=1 and 5.

  2. Lens opacities in children of Belarus affected by the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Arinchin, A.N.; Ospennikova, L.A. [Research Clinical Institute of Radiation Medicine and Endocrinology, Ministry of Health, Republic of Belarus, Aksakovschina, Minsk (Belarus)

    1998-03-01

    Reports about the increase in cataracts among the Ukrainian population living in the region of the Chernobyl Atomic Power Plant have been met with certain skepticism. At the same time, American specialists do not exclude the possibility of radiation genesis of lensopathias revealed among the citizens of Ukraine at the result of complex joint clinic-epidemiological study conducted by American and Ukrainian specialists in 1991. The aim of the investigation was to study the frequency and character of lens opacities in children permanently residing in the contaminated territories of the Republic of Belarus with anomalous high coefficients of {sup 137}Cs radionuclides through the food chain. It is well known that radiation cataract is one of the direct effects of ionizing radiation. Organ of sight is highly radiosensitive. The most radio-vulnerable part of eye is lens in which cataract is developing in response to both external and internal exposure. In children, focal lens opacities are localized in embryonic nucleus, but in elderly people, alongside with embryonic nucleus, they are also localized in adult nucleus and cortical layers. Lens opacity is the result of biochemical changes occurring in it, and it is caused by lens fibers damage. Frequency of occurrence of lensopathias in children from the main group made 82.1% which is by 12.5% more than in the control, mostly due to opacities in both lenses. (J.P.N.)

  3. Lens opacities in children of Belarus affected by the Chernobyl accident

    International Nuclear Information System (INIS)

    Arinchin, A.N.; Ospennikova, L.A.

    1998-01-01

    Reports about the increase in cataracts among the Ukrainian population living in the region of the Chernobyl Atomic Power Plant have been met with certain skepticism. At the same time, American specialists do not exclude the possibility of radiation genesis of lensopathias revealed among the citizens of Ukraine at the result of complex joint clinic-epidemiological study conducted by American and Ukrainian specialists in 1991. The aim of the investigation was to study the frequency and character of lens opacities in children permanently residing in the contaminated territories of the Republic of Belarus with anomalous high coefficients of 137 Cs radionuclides through the food chain. It is well known that radiation cataract is one of the direct effects of ionizing radiation. Organ of sight is highly radiosensitive. The most radio-vulnerable part of eye is lens in which cataract is developing in response to both external and internal exposure. In children, focal lens opacities are localized in embryonic nucleus, but in elderly people, alongside with embryonic nucleus, they are also localized in adult nucleus and cortical layers. Lens opacity is the result of biochemical changes occurring in it, and it is caused by lens fibers damage. Frequency of occurrence of lensopathias in children from the main group made 82.1% which is by 12.5% more than in the control, mostly due to opacities in both lenses. (J.P.N.)

  4. Penerapan Bahasa Alami Sederhana pada Online Public Access Catalog (Opac) Berbasis Web Semantik

    OpenAIRE

    Andri, Andri

    2012-01-01

    Online Public Access Catalog (OPAC) merupakan sistem katalog online yang memanfaatkan teknologi komputer dan internet sebagai media pengaksesan dan penyimpanan datanya. Sebuah katalog biasanya memberikan informasi mengenai koleksi yang disimpan dalam sebuah perpustakaan digital. Dalam penelitian ini akan dibuat sebuah prototipe aplikasi pencarian pada katalog online di perpustakaan Universitas Binadarma Palembang berbasis teknologi web semantik serta menerapkan pengolahan bahasa alami sederha...

  5. A Longitudinal Study of the Effects of OPAC Screen Changes on Searching Behavior and Searcher Success.

    Science.gov (United States)

    Blecic, Deborah D.; Dorsch, Josephine L.; Koenig, Melissa H.; Bangalore, Nimala S.

    1999-01-01

    Describes a longitudinal study of four sets of OPAC (online public access catalog) transaction logs that examined the effects of screen changes in helping searchers improve their search behavior. Results show that while screen changes initially had a positive impact on search behavior, they were not always sustained over time. (Author/LRW)

  6. We Never Have to Say Goodbye: Finding a Place for OPACS in Discovery Environments

    Science.gov (United States)

    Matthews, J. Greg

    2009-01-01

    It is easy to lament the shortcomings of traditional online public access catalogs (OPACs) in the Google Age. Users cannot, for example, usually input a snippet of a long-forgotten pop song's chorus into an online library catalog and almost instantly retrieve a relevant result along with hundreds of other options. On the other hand, should OPACs…

  7. Delivering Electronic Resources with Web OPACs and Other Web-based Tools: Needs of Reference Librarians.

    Science.gov (United States)

    Bordeianu, Sever; Carter, Christina E.; Dennis, Nancy K.

    2000-01-01

    Describes Web-based online public access catalogs (Web OPACs) and other Web-based tools as gateway methods for providing access to library collections. Addresses solutions for overcoming barriers to information, such as through the implementation of proxy servers and other authentication tools for remote users. (Contains 18 references.)…

  8. Calculation of radiative opacity of plasma mixtures using a relativistic screened hydrogenic model

    International Nuclear Information System (INIS)

    Mendoza, M.A.; Rubiano, J.G.; Gil, J.M.; Rodríguez, R.; Florido, R.; Espinosa, G.; Martel, P.; Mínguez, E.

    2014-01-01

    We present the code ATMED based on an average atom model and conceived for fast computing the population distribution and radiative properties of hot and dense single and multicomponent plasmas under LTE conditions. A relativistic screened hydrogenic model (RSHM), built on a new set of universal constants considering j-splitting, is used to calculate the required atomic data. The opacity model includes radiative bound–bound, bound–free, free–free, and scattering processes. Bound–bound line-shape function has contributions from natural, Doppler and electron-impact broadenings. An additional dielectronic broadening to account for fluctuations in the average level populations has been included, which improves substantially the Rosseland mean opacity results. To illustrate the main features of the code and its capabilities, calculations of several fundamental quantities of one-component plasmas and mixtures are presented, and a comparison with previously published data is performed. Results are satisfactorily compared with those predicted by more elaborate codes. - Highlights: • A new opacity code, ATMED, based on the average atom approximation is presented. • Atomic data are computed by means of a relativistic screened hydrogenic model. • An effective bound level degeneracy is included for accounting pressure ionization. • A new dielectronic line broadening is included to improve the mean opacities. • ATMED has the possibility to handle with single element and multicomponent plasmas

  9. Measuring the iron spectral opacity in solar conditions using a double ablation front scheme

    Energy Technology Data Exchange (ETDEWEB)

    Colaitis, A. [Centre Lasers Intenses et Applications, Talence (France); CEA/DRF/IRFU/DAp, CEA Saclay (France); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Ducret, J. E. [Centre Lasers Intenses et Applications, Talence (France); CEA/DRF/IRFU/DAp, CEA Saclay (France); Turck-Chieze, S [CEA/DRF/IRFU/DAp, CEA Saclay (France); Pennec, M L [CEA/DRF/IRFU/DAp, CEA Saclay (France); CEA/DIF, Arpajon (France); Blancard, C [CEA/DIF, Arpajon (France)

    2018-01-22

    We propose a new method to achieve hydrodynamic conditions relevant for the investigation of the radiation transport properties of the plasma at the base of the solar convection zone. The method is designed in the framework of opacity measurements with high-power lasers and exploits the temporal and spatial stability of hydrodynamic parameters in counter-propagating Double Ablation Front (DAF) structures.

  10. Spin glasses

    International Nuclear Information System (INIS)

    Mookerjee, Abhijit

    1976-01-01

    ''Spin glasses'', are entire class of magnetic alloys of moderate dilution, in which the magnetic atoms are far enough apart to be unlike the pure metal, but close enough so that the indirect exchange energy between them (mediated by the s-d interaction between local moments and conduction electrons) dominates all other energies. Characteristic critical phenomena displayed such as freezing of spin orientation at 'Tsub(c)' and spreading of magnetic ordering, are pointed out. Anomalous behaviour, associated with these critical phenomena, as reflected in : (i) Moessbauer spectroscopy giving hyperfine splitting at Tsub(c), (ii) maxima in susceptibility and remanent magnetism, (iii) thermopower maxima and change in slope, (iv) Characteristic cusp in susceptibility and its removal by very small magnetic fields, and (v) conductivity-resistivity measurements, are discussed. Theoretical developments aimed at explaining these phenomena, in particular, the ideas from percolation and localisation theories, and the approach based on the gellations of polymers, are discussed. Finally, a new approach based on renormalisation group in disordered systems is also briefly mentioned. (K.B.)

  11. Autofluorescence imaging of macular pigment: influence and correction of ocular media opacities

    Science.gov (United States)

    Sharifzadeh, Mohsen; Obana, Akira; Gohto, Yuko; Seto, Takahiko; Gellermann, Werner

    2014-09-01

    The healthy adult human retina contains in its macular region a high concentration of blue-light absorbing carotenoid compounds, known as macular pigment (MP). Consisting of the carotenoids lutein, zeaxanthin, and meso-zeaxanthin, the MP is thought to shield the vulnerable tissue layers in the retina from light-induced damage through its function as an optical attenuator and to protect the tissue cells within its immediate vicinity through its function as a potent antioxidant. Autofluorescence imaging (AFI) is emerging as a viable optical method for MP screening of large subject populations, for tracking of MP changes over time, and for monitoring MP uptake in response to dietary supplementation. To investigate the influence of ocular media opacities on AFI-based MP measurements, in particular, the influence of lens cataracts, we conducted a clinical trial with a large subject population (93 subjects) measured before and after cataract surgery. General AFI image contrast, retinal blood vessel contrast, and presurgery lens opacity scores [Lens Opacities Classification System III (LOCS III)] were investigated as potential predictors for image degradation. These clinical results show that lens cataracts can severely degrade the achievable pixel contrasts in the AFI images, which results in nominal MP optical density levels that are artifactually reduced. While LOCS III scores and blood vessel contrast are found to be only a weak predictor for this effect, a strong correlation exists between the reduction factor and the image contrast, which can be quantified via pixel intensity histogram parameters. Choosing the base width of the histogram, the presence or absence of ocular media opacities can be determined and, if needed, the nominal MP levels can be corrected with factors depending on the strength of the opacity.

  12. Dipolar ferromagnets and glasses (invited)

    International Nuclear Information System (INIS)

    Rosenbaum, T.F.; Wu, W.; Ellman, B.; Yang, J.; Aeppli, G.; Reich, D.H.

    1991-01-01

    What is the ground state and what are the dynamics of 10 23 randomly distributed Ising spins? We have attempted to answer these questions through magnetic susceptibility, calorimetric, and neutron scattering studies of the randomly diluted dipolar-coupled Ising magnet LiHo x Y 1-x F 4 . The material is ferromagnetic for dipole concentrations at least as low as x=0.46, with a Curie temperature obeying mean-field scaling relative to that of pure LiHoF 4 . In the dilute spin limit, an x=0.045 crystal shows very unusual glassy properties characterized by decreasing barriers to relaxation as T→0. Its properties are consistent with a single low degeneracy ground state with a large gap for excitations. A slightly more concentrated x=0.167 sample, however, supports a complex ground state with no appreciable gap, in accordance with prevailing theories of spin glasses. The underlying causes of such disparate behavior are discussed in terms of random clusters as probed by neutron studies of the x=0.167 sample. In addition to tracing the evolution of the glassy and ferromagnetic states with dipole concentration, we investigate the effects of a transverse magnetic field on the Ising spin glass, LiHo 0.167 Y 0.833 F 4 . The transverse field mixes the eigenfunctions of the ground-state Ising doublet with the otherwise inaccessible excited-state levels. We observe a rapid decrease in the characteristic relaxation times, large changes in the spectral form of the relaxation, and a depression of the spin-glass transition temperature with the addition of quantum fluctuations

  13. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  14. Arab Libraries’ Web-based OPACs: An evaluative study in the light of IFLA’s Guidelines For Online Public Access Catalogue (OPAC Displays

    Directory of Open Access Journals (Sweden)

    Sherif Kamel Shaheen

    2005-03-01

    Full Text Available The research aims at evaluating Arabic Libraries’ Web-based Catalogues in the light of Principles and Recommendations published in: IFLA’s Guidelines For OPAC Displays (September 30, 2003 Draft For Worldwide Review. The total No. Of Recommendations reached” 38 “were categorized under three main titles, as follows: User Needs (12 recommendations, Content and arrangement Principle (25 recommendations, Standardization Principle (one recommendation However that number increased to reach 88 elements when formulated as evaluative criteria and included in the study’s checklist.

  15. Diagnostic performance of qualitative shear-wave elastography according to different color map opacities for breast masses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hana; Youk, Ji Hyun, E-mail: jhyouk@yuhs.ac; Gweon, Hye Mi; Kim, Jeong-Ah; Son, Eun Ju

    2013-08-15

    Purpose: To compare the diagnostic performance of qualitative shear-wave elastography (SWE) according to three different color map opacities for breast masses Materials and methods: 101 patients aged 21–77 years with 113 breast masses underwent B-mode US and SWE under three different color map opacities (50%, 19% and 100%) before biopsy or surgery. Following SWE features were reviewed: visual pattern classification (pattern 1–4), color homogeneity (E{sub homo}) and six-point color score of maximum elasticity (E{sub col}). Combined with B-mode US and SWE, the likelihood of malignancy (LOM) was also scored. The area under the curve (AUC) was obtained by ROC curve analysis to assess the diagnostic performance under each color opacity. Results: A visual color pattern, E{sub homo}, E{sub col} and LOM scoring were significantly different between benign and malignant lesions under all color opacities (P < 0.001). For 50% opacity, AUCs of visual color pattern, E{sub col}, E{sub homo} and LOM scoring were 0.902, 0.951, 0.835 and 0.975. But, for each SWE feature, there was no significant difference in the AUC among three different color opacities. For all color opacities, visual color pattern and E{sub col} showed significantly higher AUC than E{sub homo}. In addition, a combined set of B-mode US and SWE showed significantly higher AUC than SWE alone for color patterns, E{sub homo}, but no significant difference was found in E{sub col}. Conclusion: Qualitative SWE was useful to differentiate benign from malignant breast lesion under all color opacities. The difference in color map opacity did not significantly influence diagnostic performance of SWE.

  16. Diagnostic performance of qualitative shear-wave elastography according to different color map opacities for breast masses

    International Nuclear Information System (INIS)

    Kim, Hana; Youk, Ji Hyun; Gweon, Hye Mi; Kim, Jeong-Ah; Son, Eun Ju

    2013-01-01

    Purpose: To compare the diagnostic performance of qualitative shear-wave elastography (SWE) according to three different color map opacities for breast masses Materials and methods: 101 patients aged 21–77 years with 113 breast masses underwent B-mode US and SWE under three different color map opacities (50%, 19% and 100%) before biopsy or surgery. Following SWE features were reviewed: visual pattern classification (pattern 1–4), color homogeneity (E homo ) and six-point color score of maximum elasticity (E col ). Combined with B-mode US and SWE, the likelihood of malignancy (LOM) was also scored. The area under the curve (AUC) was obtained by ROC curve analysis to assess the diagnostic performance under each color opacity. Results: A visual color pattern, E homo , E col and LOM scoring were significantly different between benign and malignant lesions under all color opacities (P < 0.001). For 50% opacity, AUCs of visual color pattern, E col , E homo and LOM scoring were 0.902, 0.951, 0.835 and 0.975. But, for each SWE feature, there was no significant difference in the AUC among three different color opacities. For all color opacities, visual color pattern and E col showed significantly higher AUC than E homo . In addition, a combined set of B-mode US and SWE showed significantly higher AUC than SWE alone for color patterns, E homo , but no significant difference was found in E col . Conclusion: Qualitative SWE was useful to differentiate benign from malignant breast lesion under all color opacities. The difference in color map opacity did not significantly influence diagnostic performance of SWE

  17. Optical spectroscopy of rare earth-doped oxyfluoro-tellurite glasses ...

    Indian Academy of Sciences (India)

    2017-08-16

    Aug 16, 2017 ... glass matrix with different RE ions for optical properties is of importance. ... Figure 1. XRD pattern of the tellurite glasses studied. Table 1. Composition and glass transition ... convoluted using Gaussian line shape. Parameters like .... On the other hand, in Er3+ ion, the ground state 4I15/2 itself has manifold.

  18. Can You Get a Sunburn Through Glass? Theory and an Experiment.

    Science.gov (United States)

    Bartels, Richard; Loxsom, Fred

    1995-01-01

    Discusses factors that determine whether or not a sunburn is possible under glass, including the spectral dependence of the skin's sensitivity to sunburn, the ground-level spectrum of solar radiation, and the wavelength dependence of the transmission for the particular piece of glass. Concludes that it is possible to get sunburned through glass.…

  19. Characteristics of interventional cardiologists and their work practices for the study on radiation-induced lens opacities based on the methodology developed by ELDO—preliminary results

    International Nuclear Information System (INIS)

    Domienik, Joanna; Gryglak, Szymon; Jurewicz, Joanna

    2016-01-01

    Preliminary results of the Polish epidemiology study on eye lens opacities among interventional cardiologists (ICs), based on the methodology proposed by ELDO (epidemiological studies of radio-induced cataracts in interventional cardiologists and radiologists: methodology implementation), are presented. The aim of the study is to test the hypothesis concerning the excess risk of cataract in the group of ICs. The first results concern the study population characteristics, including the most important confounding factors for cataract, as well as a detailed description of the work practices in interventional cardiology needed in order to reconstruct the cumulative eye lens dose. The data from 69 ICs and 23 controls collected based on the general medical questionnaire and the occupational questionnaire (for ICs only) were analyzed. The mean age of ICs and of the control group was 41 and 44, respectively, while the mean duration of work for exposed physicians was 9 years. The analysis of the data from the occupational questionnaire concerning the procedures performed, the use of various access routes, as well as radiation protection tools (eye lens glasses, ceiling suspended transparent shield, etc.) are also presented. On the basis of this information and additional assumptions about the doses per procedure (as well as reduction factors for various types of radiation measures), the cumulative doses to the eye lens of ICs were evaluated. They ranged up to 1.55 Sv and 0.4 Sv for left and right eye, respectively; however, the dose to only 3% of ICs exceeded the new threshold for development of eye lens opacities (0.5 Gy) proposed by the ICRP

  20. Radiative properties of stellar envelopes: Comparison of asteroseismic results to opacity calculations and measurements for iron and nickel

    International Nuclear Information System (INIS)

    Turck-Chieze, S.; Gilles, D.; Le Pennec, M.; Blenski, T.; Thais, F.; Bastiani-Ceccotti, S.; Blancard, C.; Caillaud, T.; Cosse, P.; Faussurier, G.; Gilleron, F.; Pain, J.C.; Reverdin, C.; Silvert, V.; Villette, B.; Busquet, M.; Colgan, J.; Guzik, J.; Kilcrease, D.P.; Magee, N.H.; Delahaye, F.; Zeippen, C.J.; Ducreta, J.E.; Fontes, C.J.; Harris, J.W.; Loisel, G.

    2013-01-01

    The international OPAC consortium consists of astrophysicists, plasma physicists and experimentalists who examine opacity calculations used in stellar physics that appear questionable and perform new calculations and laser experiments to understand the differences and improve the calculations. We report on iron and nickel opacities for envelopes of stars from 2 to 14 M and deliver our first conclusions concerning the reliability of the used calculations by illustrating the importance of the configuration interaction and of the completeness of the calculations for temperatures around 15-27 eV. (authors)

  1. An investigation of the opacity of high-Z mixture and implications for inertial confinement fusion hohlraum design

    International Nuclear Information System (INIS)

    Wang, P.; MacFarlane, J.J.; Orzechowski, T.J.

    1997-01-01

    We use an unresolved transition array model to investigate the opacities of high-Z materials and their mixtures which are of interest to indirect-drive inertial confinement fusion hohlraum design. In particular, we report on calculated opacities for pure Au, Gd, and Sm, as well as Au endash Sm and Au endash Gd mixtures. Our results indicate that mixtures of Au endash Gd and Au endash Sm can produce a significant enhancement in the Rosseland mean opacity. Radiation hydrodynamics simulations of Au radiation burnthrough are also presented, and compared with NOVA experimental data. copyright 1997 American Institute of Physics

  2. lead glass brick

    CERN Multimedia

    When you look through the glass at a picture behind, the picture appears raised up because light is slowed down in the dense glass. It is this density (4.06 gcm-3) that makes lead glass attractive to physicists. The refractive index of the glass is 1.708 at 400nm (violet light), meaning that light travels in the glass at about 58% its normal speed. At CERN, the OPAL detector uses some 12000 blocks of glass like this to measure particle energies.

  3. Avaliação das propriedades físicas e mecânicas de concretos produzidos com vidro cominuído como agregado fino Evaluation of physical and mechanical properties of concretes produced with ground waste glass as fine aggregate

    Directory of Open Access Journals (Sweden)

    D. A. R López

    2005-12-01

    Full Text Available O presente trabalho insere-se na proposta da utilização racional dos recursos naturais não renováveis. Ele tem por objetivo, estudar a viabilidade técnica da utilização de vidro não reciclado como material agregado ao concreto, especificamente pela comparação das propriedades mecânicas de concretos fabricados com o novo componente, visando a sua utilização para fins estruturais. A comparação foi realizada por meio do estudo das propriedades mecânicas de concretos produzidos primeiramente com a substituição da areia por vidro moído e, numa segunda parte, pela adição do vidro moído sobre a massa de areia. Os resultados desta pesquisa mostraram que com a substituição de 5% em peso do agregado fino (areia por vidro numa granulometria variando entre 150-300 µm houve um aumento de ~ 60% na resistência à compressão do concreto fabricado, o que seria causado pela diminuição da porosidade do concreto por causa da penetração de vidro fino nos vazios. A utilização de outras faixas granulométricas acarretou aumentos menores, porém todos superiores aos valores apresentados pelo corpo de referência. Por outro lado, a adição de vidro moído na granulometria 150-300 µm em percentagens de até 20% sobre o peso do agregado fino (areia teve um efeito bem diferente sobre o concreto produzido. A maior resistência à compressão, 56,6% superior à do material de referência, foi obtida com a adição de 5% em peso de vidro fino sobre o peso da areia. Acima desta percentagem, houve uma diminuição da resistência à compressão do concreto. Isto estaria influenciado pelo aumento da quantidade de material seco que deveria ser hidratado, uma vez que a relação água/cimento foi constante.This work consists on the proposal of rational utilization of non-renewable natural resources. It has the objective of studying the technical viability of utilization of ground waste glass as material aggregate to concrete specifically by the

  4. Influence of artificial accelerated aging on the color stability and opacity of composites of different shades.

    Science.gov (United States)

    Mundim, F M; Da Fonseca Roberti Garcia, L; Silva Sousa, A B; Cruvinel, D R; De Carvalho Panzeri Pires-De-Souza, F

    2010-10-01

    The aim of this study was to evaluate the influence of artificial accelerated aging on the color stability and opacity of composites of different shades. Four composites for direct use (Heliomolar, 4 Seasons, Tetric EvoCeram; QuiXfil) and one for indirect use (SR Adoro) in two shades were used: light (A2) and dark (C3 for direct, and D4 for indirect composite). QuiXfil was obtained in Universal shade. A Teflon matrix (12 X 2 mm) was used to obtain 54 specimens (N=6), which were submitted to color and opacity analysis (Spectrophotometer PCB 6807, Byk Gardner) before and after artificial accelerated aging for 384 hours. After the statistical analysis (2-way ANOVA - Bonferroni - PArtificial accelerated aging interfered in the optical properties assessed; however, the alterations seemed to be more related to the composites composition than to their shade.

  5. Femtosecond laser-assisted keratoplasty in a child with corneal opacity:case report

    Directory of Open Access Journals (Sweden)

    E. Yu. Markova

    2014-01-01

    Full Text Available Corneal opacities are the fourth cause of blindness world-wide. Over the past two centuries, various corneal transplantation (i.e., keratoplasty methods have been developed and improved. Nowadays, femtolaserssisted keratoplasty is one of most promising techniques. Femtosecond laser have several advantages that provide additional surgical benefits. Among them, no thermal injury, the ability to cut deeply on a single plane and to perform various corneal profiles should be mentioned. In children, corneal disorders are of special importance while femtosecondassisted keraatoplasty case reports are rare. Here, we describe femtosecond laserssisted penetrating keratoplasty in a girl with a rough central corneal opacity.

  6. Primary Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma with a Nodular Opacity: Report of a Case.

    Science.gov (United States)

    Yoshino, Naoyuki; Hirata, Tomomi; Takeuchi, Chie; Usuda, Jitsuo; Hosone, Masaru

    2017-01-01

    Herein, we describe our experience in treating a case of primary pulmonary mucosa-associated lymphoid tissue lymphoma detected as a nodular opacity. A 79-year-old man was referred to our hospital. Computed tomography showed a nodular opacity measuring 20 mm in diameter with regular margins in segment 5 of the right middle lobe of the lung. Although the bronchoscopic brush cytology result was class III, the patient was tentatively diagnosed with suspected mucosa-associated lymphoid tissue lymphoma. A thoracoscopic right middle lobectomy was performed. The pathological findings showed nodular proliferation of small to medium-sized, mature-appearing atypical lymphoid cells, lymphoepithelial lesions, and vague follicles suggesting follicular colonization in some areas. The patient was diagnosed with low-grade small B-cell lymphoma and mucosa-associated lymphoid tissue lymphoma. He has remained well to date, 23 months after surgery, without evidence of recurrence.

  7. Development of an Aerosol Opacity Retrieval Algorithm for Use with Multi-Angle Land Surface Images

    Science.gov (United States)

    Diner, D.; Paradise, S.; Martonchik, J.

    1994-01-01

    In 1998, the Multi-angle Imaging SpectroRadiometer (MISR) will fly aboard the EOS-AM1 spacecraft. MISR will enable unique methods for retrieving the properties of atmospheric aerosols, by providing global imagery of the Earth at nine viewing angles in four visible and near-IR spectral bands. As part of the MISR algorithm development, theoretical methods of analyzing multi-angle, multi-spectral data are being tested using images acquired by the airborne Advanced Solid-State Array Spectroradiometer (ASAS). In this paper we derive a method to be used over land surfaces for retrieving the change in opacity between spectral bands, which can then be used in conjunction with an aerosol model to derive a bound on absolute opacity.

  8. Limb-darkening opacity experiment using a laser-heated plasma

    International Nuclear Information System (INIS)

    Hoffman, N.M.; Miller, L.W.; Mack, J.M.

    1978-10-01

    The limb-darkening technique, a method for measuring monochromatic opacity information, which has had successful astrophysical applications, is reviewed. The application of the technique to laser-produced plasmas in materials and regimes of temperature and density of interest to weapons designers is discussed, and the magnitude of the limb-darkening effect in such situations is estimated. Finally, an experimental study, now in progress, to evaluate the feasibility of this approach is described. 10 figures

  9. Conceptual design of initial opacity experiments on the national ignition facility

    Science.gov (United States)

    Heeter, R. F.; Bailey, J. E.; Craxton, R. S.; Devolder, B. G.; Dodd, E. S.; Garcia, E. M.; Huffman, E. J.; Iglesias, C. A.; King, J. A.; Kline, J. L.; Liedahl, D. A.; McKenty, P. W.; Opachich, Y. P.; Rochau, G. A.; Ross, P. W.; Schneider, M. B.; Sherrill, M. E.; Wilson, B. G.; Zhang, R.; Perry, T. S.

    2017-02-01

    Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative-convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperatures eV and electron densities 21~\\text{cm}-3$ . The iron will be probed using continuum X-rays emitted in a ps, diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design, of the NIF beams deliver 500 kJ to the mm diameter hohlraum, and the remaining directly drive the CH capsule with 200 kJ. Calculations indicate this capsule backlighter should outshine the iron sample, delivering a point-projection transmission opacity measurement to a time-integrated X-ray spectrometer viewing down the hohlraum axis. Preliminary experiments to develop the backlighter and hohlraum are underway, informing simulated measurements to guide the final design.

  10. Glass and nuclear wastes

    International Nuclear Information System (INIS)

    Sombret, C.

    1982-10-01

    Glass shows interesting technical and economical properties for long term storage of solidified radioactive wastes by vitrification or embedding. Glass composition, vitrification processes, stability under irradiation, thermal stability and aqueous corrosion are studied [fr

  11. Microstructuring of glasses

    CERN Document Server

    Hülsenberg, Dagmar; Bismarck, Alexander

    2008-01-01

    As microstructured glass becomes increasingly important for microsystems technology, the main application fields include micro-fluidic systems, micro-analysis systems, sensors, micro-actuators and implants. And, because glass has quite distinct properties from silicon, PMMA and metals, applications exist where only glass devices meet the requirements. The main advantages of glass derive from its amorphous nature, the precondition for its - theoretically - direction-independent geometric structurability. Microstructuring of Glasses deals with the amorphous state, various glass compositions and their properties, the interactions between glasses and the electromagnetic waves used to modify it. Also treated in detail are methods for influencing the geometrical microstructure of glasses by mechanical, chemical, thermal, optical, and electrical treatment, and the methods and equipment required to produce actual microdevices.

  12. Effect of cigarette smoking on the detection of small radiographic opacities in inorganic dust diseases

    International Nuclear Information System (INIS)

    Blanc, P.D.; Gamsu, G.

    1988-01-01

    Whether cigarette smoking can cause radiographic opacities indistinguishable from those due to pneumoconiosis remains controversial. The situation becomes clearer when one limits the abnormalities to those that can be standardized under the International Labour Office (ILO) classification system. The bulk of the evidence indicates that, using the ILO system, cigarette smoking alone is not associated with radiographic opacities that would be mistaken for pneumoconiosis with sufficient frequency to be of any practical importance. The effects of cigarette smoking, as a cofactor, in conjunction with occupational dust exposure depend on the type of dust. No relationship has been convincingly demonstrated for coal dust or silica. Only with asbestos exposure does there appear to be a significant cigarette smoking-associated increase in the frequency of irregular radiographic opacities. This increase does not appear to translate into a restrictive impairment in pulmonary function. The limited information available indicates that the features of asbestosis on high-resolution computed tomography are not similarly related to cigarette smoking. Additional research is needed to substantiate the relationship between smoking and occupational exposure to dust of many types, and also the possible imaging and pathophysiologic significance of their interactions. 47 references

  13. Target simulations with SCROLL non-LTE opacity/emissivity databases.

    Science.gov (United States)

    Klapisch, M.; Colombant, D.; Bar-Shalom, A.

    2001-10-01

    SCROLL[1], a collisional radiative model and code based on superconfigurations, is able to compute high Z non-LTE opacities and emissivities accurately and efficiently. It was used to create opacity/emissivity databases for Pd, Lu, Au on a 50 temperatures/80 densities grid. Incident radiation field was shown to have no effect on opacities in the case of interest, and was not taken into account. These databases were introduced in the hydrocode FAST1D[2]. SCROLL also gives an ionization temperature Tz which is used in FAST1D to obtain non-LTE corrections to the equation of state. Results will be compared to those of a previous version using Busquet’s algorithm[3]. Work supported by USDOE under a contract with NRL. [1] A. Bar-Shalom, J. Oreg and M. Klapisch, J. Quant. Spectrosc. Radiat. Transfer, 65, 43(2000). [2] J. H. Gardner, A. J. Schmitt, J. P. Dahlburg, C. J. Pawley, S. E. Bodner, S. P. Obenschain, V. Serlin and Y. Aglitskiy, Phys. Plasmas, 5, 1935 (1998). [3] M. Busquet, Phys. Fluids B, 5, 4191 (1993).

  14. Random sampling technique for ultra-fast computations of molecular opacities for exoplanet atmospheres

    Science.gov (United States)

    Min, M.

    2017-10-01

    Context. Opacities of molecules in exoplanet atmospheres rely on increasingly detailed line-lists for these molecules. The line lists available today contain for many species up to several billions of lines. Computation of the spectral line profile created by pressure and temperature broadening, the Voigt profile, of all of these lines is becoming a computational challenge. Aims: We aim to create a method to compute the Voigt profile in a way that automatically focusses the computation time into the strongest lines, while still maintaining the continuum contribution of the high number of weaker lines. Methods: Here, we outline a statistical line sampling technique that samples the Voigt profile quickly and with high accuracy. The number of samples is adjusted to the strength of the line and the local spectral line density. This automatically provides high accuracy line shapes for strong lines or lines that are spectrally isolated. The line sampling technique automatically preserves the integrated line opacity for all lines, thereby also providing the continuum opacity created by the large number of weak lines at very low computational cost. Results: The line sampling technique is tested for accuracy when computing line spectra and correlated-k tables. Extremely fast computations ( 3.5 × 105 lines per second per core on a standard current day desktop computer) with high accuracy (≤1% almost everywhere) are obtained. A detailed recipe on how to perform the computations is given.

  15. An Analysis of Source Tilting and Sub-cell Opacity Sampling for IMC

    Energy Technology Data Exchange (ETDEWEB)

    Wollaeger, Ryan T. [Los Alamos National Laboratory; Urbatsch, Todd J. [Los Alamos National Laboratory; Wollaber, Allan B. [Los Alamos National Laboratory; Densmore, Jeffery D. [Los Alamos National Laboratory

    2012-08-02

    Implicit Monte Carlo (IMC) is a stochastic method for solving the radiative transfer equations for multiphysics application with the material in local thermodynamic equilibrium. The IMC method employs a fictitious scattering term that is computed from an implicit discretization of the material temperature equation. Unfortunately, the original histogram representation of the temperature and opacity with respect to the spatial domain leads to nonphysically fast propagation of radiation waves through optically thick material. In the past, heuristic source tilting schemes have been used to mitigate the numerical teleportation error of the radiation particles in IMC that cause this overly rapid radiation wave propagation. While improving the material temperature profile throughout the time duration, these tilting schemes alone do not generally alleviate the teleportation error to suitable levels. Another means of potentially reducing teleportation error in IMC is implementing continuous sub-cell opacities based on sub-cell temperature profiles. We present here an analysis of source tilting and continuous sub-cell opacity sampling applied to various discretizations of the temperature equation. Through this analysis, we demonstrate that applying both heuristics does not necessarily yield more accurate results if the discretization of the material equation is inconsistent with the Monte Carlo sub-cell transport.

  16. Measurement of optical glasses

    International Nuclear Information System (INIS)

    Nicolau-Rebigan, S.

    1978-11-01

    The possibilities of measurement of the optical glasses parameters needed in building optical devices especially in lasers devices are presented. In the first chapter the general features of the main optical glasses as well as the modalities of obtaining them are given. Chapter two defines the optical glass parameters, and the third chapter describes the measuring methods of the optical glass parameters. Finally, the conclusions which point out the utilization of this paper are presented. (author)

  17. Mechanically reinforced glass beams

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Olesen, John Forbes

    2007-01-01

    laminated float glass beam is constructed and tested in four-point bending. The beam consist of 4 layers of glass laminated together with a slack steel band glued onto the bottom face of the beam. The glass parts of the tested beams are \\SI{1700}{mm} long and \\SI{100}{mm} high, and the total width of one...

  18. Configuration interaction effect on open M shell Fe and Ni LTE spectral opacities, Rosseland and Planck means

    International Nuclear Information System (INIS)

    Gilles, D; Busquet, M; Gilleron, F; Pain, J-C; Klapisch, M

    2016-01-01

    We have recently shown that iron and nickel open M-shell opacity spectra, up to Δn = 2 are very sensitive to Configuration Interaction (CI) treatments at temperature around 15 eV and for various densities. To do so we had compared extensive CI calculations obtained with two opacity codes HULLAC-v9 and SCO-RCG. In this work we extend these comparisons to a first evaluation of CI effects on Rosseland and Planck means. (paper)

  19. GASEOUS MEAN OPACITIES FOR GIANT PLANET AND ULTRACOOL DWARF ATMOSPHERES OVER A RANGE OF METALLICITIES AND TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    Freedman, Richard S. [SETI Institute, Mountain View, CA (United States); Lustig-Yaeger, Jacob [Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Lupu, Roxana E.; Marley, Mark S. [Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, CA (United States); Lodders, Katharina, E-mail: Richard.S.Freedman@nasa.gov [Planetary Chemistry Laboratory, Washington University, St. Louis, MO (United States)

    2014-10-01

    We present new calculations of Rosseland and Planck gaseous mean opacities relevant to the atmospheres of giant planets and ultracool dwarfs. Such calculations are used in modeling the atmospheres, interiors, formation, and evolution of these objects. Our calculations are an expansion of those presented in Freedman et al. to include lower pressures, finer temperature resolution, and also the higher metallicities most relevant for giant planet atmospheres. Calculations span 1 μbar to 300 bar, and 75-4000 K, in a nearly square grid. Opacities at metallicities from solar to 50 times solar abundances are calculated. We also provide an analytic fit to the Rosseland mean opacities over the grid in pressure, temperature, and metallicity. In addition to computing mean opacities at these local temperatures, we also calculate them with weighting functions up to 7000 K, to simulate the mean opacities for incident stellar intensities, rather than locally thermally emitted intensities. The chemical equilibrium calculations account for the settling of condensates in a gravitational field and are applicable to cloud-free giant planet and ultracool dwarf atmospheres, but not circumstellar disks. We provide our extensive opacity tables for public use.

  20. Dependent lung opacity at thin-section CT: evaluation by spirometrically-gated CT of the influence of lung volume

    International Nuclear Information System (INIS)

    Lee, Ki Nam; Yoon, Seong Kuk; Sohn, Choon Hee; Choi, Pil Jo; Webb, W. Richard

    2002-01-01

    To evaluate the influence of lung volume on dependent lung opacity seen at thin-section CT. In thirteen healthy volunteers, thin-section CT scans were performed at three levels (upper, mid, and lower portion of the lung) and at different lung volumes (10, 30, 50, and 100% vital capacity), using spirometric gated CT. Using a three-point scale, two radiologists determined whether dependent opacity was present, and estimated its degree. Regional lung attenuation at a level 2 cm above the diaphragm was determined using semiautomatic segmentation, and the diameter of a branch of the right lower posterior basal segmental artery was measured at each different vital capacity. At all three anatomic levels, dependent opacity occurred significantly more often at lower vital capacities (10, 30%) than at 100% vital capacity (p = 0.001). Visually estimated dependent opacity was significantly related to regional lung attenuation (p < 0.0001), which in dependent areas progressively increased as vital capacity decreased (p < 0.0001). The presence of dependent opacity and regional lung attenuation of a dependent area correlated significantly with increased diameter of a segmental arterial branch (r = 0.493 and p = 0.0002; r = 0.486 and p 0.0003, respectively). Visual estimation and CT measurements of dependent opacity obtained by semiautomatic segmentation are significantly influenced by lung volume and are related to vascular diameter

  1. Diagnostic performance of qualitative shear-wave elastography according to different color map opacities for breast masses.

    Science.gov (United States)

    Kim, Hana; Youk, Ji Hyun; Gweon, Hye Mi; Kim, Jeong-Ah; Son, Eun Ju

    2013-08-01

    To compare the diagnostic performance of qualitative shear-wave elastography (SWE) according to three different color map opacities for breast masses 101 patients aged 21-77 years with 113 breast masses underwent B-mode US and SWE under three different color map opacities (50%, 19% and 100%) before biopsy or surgery. Following SWE features were reviewed: visual pattern classification (pattern 1-4), color homogeneity (Ehomo) and six-point color score of maximum elasticity (Ecol). Combined with B-mode US and SWE, the likelihood of malignancy (LOM) was also scored. The area under the curve (AUC) was obtained by ROC curve analysis to assess the diagnostic performance under each color opacity. A visual color pattern, Ehomo, Ecol and LOM scoring were significantly different between benign and malignant lesions under all color opacities (Pbreast lesion under all color opacities. The difference in color map opacity did not significantly influence diagnostic performance of SWE. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  3. Multiple Glass Ceilings

    OpenAIRE

    Russo, Giovanni; Hassink, Wolter

    2011-01-01

    Both vertical (between job levels) and horizontal (within job levels) mobility can be sources of wage growth. We find that the glass ceiling operates at both margins. The unexplained part of the wage gap grows across job levels (glass ceiling at the vertical margin) and across the deciles of the intra-job-level wage distribution (glass ceiling at the horizontal margin). This implies that women face many glass ceilings, one for each job level above the second, and that the glass ceiling is a p...

  4. Homogeneity of Inorganic Glasses

    DEFF Research Database (Denmark)

    Jensen, Martin; Zhang, L.; Keding, Ralf

    2011-01-01

    Homogeneity of glasses is a key factor determining their physical and chemical properties and overall quality. However, quantification of the homogeneity of a variety of glasses is still a challenge for glass scientists and technologists. Here, we show a simple approach by which the homogeneity...... of different glass products can be quantified and ranked. This approach is based on determination of both the optical intensity and dimension of the striations in glasses. These two characteristic values areobtained using the image processing method established recently. The logarithmic ratio between...

  5. Rational decisions, random matrices and spin glasses

    Science.gov (United States)

    Galluccio, Stefano; Bouchaud, Jean-Philippe; Potters, Marc

    We consider the problem of rational decision making in the presence of nonlinear constraints. By using tools borrowed from spin glass and random matrix theory, we focus on the portfolio optimisation problem. We show that the number of optimal solutions is generally exponentially large, and each of them is fragile: rationality is in this case of limited use. In addition, this problem is related to spin glasses with Lévy-like (long-ranged) couplings, for which we show that the ground state is not exponentially degenerate.

  6. Leaching of glass

    International Nuclear Information System (INIS)

    Hench, L.L.

    1977-01-01

    Understanding surface compositional profiles of glasses over a range of 0-2000 A with a variety of analytical instruments shows that five general types of glass surfaces exist. The surface character of a glass article depends upon bulk composition and environmental history during which surface dealkalization, film formation, and network dissolution can occur. Environmental-surface interactions generally result in complex compositional profiles of all the constituents in a glass. Durable glasses almost always develop a stable surface film which has a higher concentration of network formers than the bulk composition. Compositional effects that are used to improve glass durability usually improve the stability of the surface films. Durability tests or service conditions that lead to film destruction are especially severe for the most silicate glasses. 43 references

  7. Effects of adhesive used as modeling liquid on the stability of the color and opacity of composites.

    Science.gov (United States)

    Araujo, Fernanda Santos; Barros, Mellany Cristie Ramos; Santana, Márcia Luciana Carregosa; de Jesus Oliveira, Ludmila Smith; Silva, Paula Fernanda Damasceno; Lima, Giana da Silveira; Faria-E-Silva, André Luis

    2018-04-01

    This study evaluated the effects of adhesive type used as modeling liquid on the stability of the color and opacity of composites submitted to thermal cycling in staining solutions followed by a bleaching procedure. Thirty cylinder-shaped composite specimens (10 mm diameter × 1.5 mm thickness) were built using or not using (control) an adhesive (Adper Universal or Scotchbond Multipurpose) as the modeling liquid. After polishing procedures, the color and opacity were measured, and the specimens were submitted to 200 thermal cycles with 10 s of dwell time in baths of grape juice at 5°C, water at 37°C, and coffee at 55°C. Changes in opacity and color caused by the staining solutions were measured. Then, the specimens were bleached with 35% hydrogen peroxide for 45 minutes followed by color/opacity measurements. Data were analyzed by ANOVA and Tukey's test (α = 0.05). The use of modeling liquids did not affect the initial color and opacity of composite. Reduced changes to color (E 00  = 3.44) and opacity (+2.67%) were observed for specimens modeled using Adper Universal. Bleaching procedures reduced the color (E 00  = 1.9-3.8) and opacity (-2.3 to 3.1%) alterations caused by staining solutions but were unable to restore the values observed at baseline. The use of universal adhesive as modeling liquid significantly reduced the color and opacity changes caused by staining solutions, and the bleaching procedure partially re-established the opacity and color of the composites. This study evaluates whether using adhesive systems for modeling a composite affects the color and opacity changes caused by staining solutions followed by a bleaching procedure. The findings suggest that the use of a universal adhesive as modeling liquid can reduce the alterations in optical properties caused by staining solutions, and the application of high-concentrated hydrogen peroxide over the composite reduce the color changes without fully recover the initial color. © 2018

  8. 3D printed glass: surface finish and bulk properties as a function of the printing process

    Science.gov (United States)

    Klein, Susanne; Avery, Michael P.; Richardson, Robert; Bartlett, Paul; Frei, Regina; Simske, Steven

    2015-03-01

    It is impossible to print glass directly from a melt, layer by layer. Glass is not only very sensitive to temperature gradients between different layers but also to the cooling process. To achieve a glass state the melt, has to be cooled rapidly to avoid crystallization of the material and then annealed to remove cooling induced stress. In 3D-printing of glass the objects are shaped at room temperature and then fired. The material properties of the final objects are crucially dependent on the frit size of the glass powder used during shaping, the chemical formula of the binder and the firing procedure. For frit sizes below 250 μm, we seem to find a constant volume of pores of less than 5%. Decreasing frit size leads to an increase in the number of pores which then leads to an increase of opacity. The two different binders, 2- hydroxyethyl cellulose and carboxymethylcellulose sodium salt, generate very different porosities. The porosity of samples with 2-hydroxyethyl cellulose is similar to frit-only samples, whereas carboxymethylcellulose sodium salt creates a glass foam. The surface finish is determined by the material the glass comes into contact with during firing.

  9. From stellar plasmas to laboratory plasmas: application to X and XUV opacity measurements

    International Nuclear Information System (INIS)

    Loisel, G.

    2011-01-01

    The general context of this thesis is the one of radiative properties of high energy density matter. Energy densities involved (>10 11 J/cm 3 ) implies that a large part of energy exchange goes through radiation-matter interactions. My studies deal with spectral opacity, a fundamental parameter for modelling stellar interiors and constitute a propitious observable to experimental tests of theoretical descriptions of hot and dense plasmas physics. Although the main application of my work is stellar plasmas it can be useful for plasma diagnostics in inertial confinement fusion. My work activities are centred on the experimental study of opacities of plasmas at local thermodynamic equilibrium for temperature conditions of a few tens eV (a few 100000 K) and a few mg/cm 3 in matter density. Plasmas are obtained in conditions as homogenous as possible using the radiative heating of a laser-irradiated cavity. Heating is provided through a laser beam of high energy (100-300 J) and with relatively long pulse duration of a few nanosecond. For such measurements we could benefit from the LULI lasers configuration coupling the nanosecond beam with a picosecond one used to perform on a short duration the measurement of the plasma transmission. The use of short pulse laser to produce a short time radiography beam was a first achievement for this kind of experience. In the spectral range of keV photons, absorbing transitions 2p-3d or 3d-4f of elements of moderate or high atomic number have been probed. They present absorption structures which shape results mainly of the competition between spin-orbit splitting and statistical broadening effects. It appeared that this competition depends strongly on the atomic number Z. Thus for similar plasma parameters we explored opacities of Iron, Nickel, Copper and Germanium (Z around 30) in a first series of measurement and the one of Barium, Samarium and Gadolinium (Z around 60) in a second campaign

  10. A test of lens opacity as an indicator of preclinical Alzheimer Disease.

    Science.gov (United States)

    Bei, Ling; Shui, Ying-Bo; Bai, Fang; Nelson, Suzanne K; Van Stavern, Gregory P; Beebe, David C

    2015-11-01

    Previous studies reported that characteristic lens opacities were present in Alzheimer Disease (AD) patients postmortem. We therefore determined whether cataract grade or lens opacity is related to the risk of Alzheimer dementia in participants who have biomarkers that predict a high risk of developing the disease. AD biomarker status was determined by positron emission tomography-Pittsburgh compound B (PET-PiB) imaging and cerebrospinal fluid (CSF) levels of Aβ42. Cognitively normal participants with a clinical dementia rating of zero (CDR = 0; N = 40) or with slight evidence of dementia (CDR = 0.5; N = 2) were recruited from longitudinal studies of memory and aging at the Washington University Knight Alzheimer's Disease Research Center. The age, sex, race, cataract type and cataract grade of all participants were recorded and an objective measure of lens light scattering was obtained for each eye using a Scheimpflug camera. Twenty-seven participants had no biomarkers of Alzheimer dementia and were CDR = 0. Fifteen participants had biomarkers indicating increased risk of AD, two of which were CDR = 0.5. Participants who were biomarker positive were older than those who were biomarker negative. Biomarker positive participants had more advanced cataracts and increased cortical light scattering, none of which reached statistical significance after adjustment for age. We conclude that cataract grade or lens opacity is unlikely to provide a non-invasive measure of the risk of developing Alzheimer dementia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Effect of Biodiesel of Spent Cooking Oil Addition at Diesel Fuel to Opacity and Gas Emission Throw Away of CO, CO2 and HC

    International Nuclear Information System (INIS)

    Setyadji, Moch; Endang Susiantini

    2007-01-01

    Investigation of biodiesel spent cooking oil addition effect at diesel fuel to opacity and gas emission throw away on various engine rotation speed has been done. The variables observed were fuel specific used i.e. pure diesel fuel, biodiesel mix 5% (B5), mix 10% (B10), mix 15% (B15), mix 20% (B20) and engine rotation speed. Gas emission throw away observed were CO, CO 2 , HC and opacity. Opacity and gas emission throwaway were observed by Opacity Sagem apparatus and gas analyzer. Result of experiment showed that biodiesel addition at diesel fuel was very decreasing opacity and gas emission throw away. The opacity lowest on B20, gas emission throw away lowest of CO on B10, CO 2 on B10 and HC on B20. (author)

  12. DWPF waste glass Product Composition Control System

    International Nuclear Information System (INIS)

    Brown, K.G.; Postles, R.L.

    1992-01-01

    The Defense Waste Processing Facility (DWPF) will be used to blend aqueous radwaste (PHA) with solid radwaste (Sludge) in a waste receipt vessel (the SRAT). The resulting SRAT material is transferred to the SME an there blended with ground glass (Frit) to produce a batch of melter feed slurry. The SME material is passed to a hold tank (the MFT) which is used to continuously feed the DWPF melter. The melter. The melter produces a molten glass wasteform which is poured into stainless steel canisters for cooling and, ultimately, shipment to and storage in a geologic repository. The Product Composition Control System (PCCS) is the system intended to ensure that the melt will be processible and that the glass wasteform will be acceptable. This document provides a description of this system

  13. Calculation of opacities and emissivities for carbon plasmas under NLTE and LTE conditions

    International Nuclear Information System (INIS)

    Gil, J.M.; Rodriguez, R.; Florido, R.; Rubiano, J.G.; Martel, P.; Sauvan, P.; Minguez, E.

    2006-01-01

    We calculate different optical properties for carbon plasma in a wide range of temperatures and densities by using ATOM3R-OP code which has been recently developed. In this code we have implemented the rate equations, the Saha equation (for local thermodynamic equilibrium) and the coronal equilibrium model. We have calculated average ionizations, level populations, opacities and emissivities and we focus our study on the identification with our code of coronal equilibrium, non-local thermodynamic equilibrium and local thermodynamic equilibrium regions for this kind of plasma. Moreover, we analyse the differences in the optical properties when they are calculated in non-local thermodynamic equilibrium and local thermodynamic equilibrium. (authors)

  14. Study of Opacity Effects on Emission Lines at EXTRAP T2R RFP

    Science.gov (United States)

    Stancalie, Viorica; Rachlew, Elisabeth

    We have investigated the influence of opacity on hydrogen (H-α and Ly-β) and Li-like oxygen emission lines from the EXTRAP T2R reversed field pinch. We used the Atomic Data Analysis System (AzDAS) based on the escape factor approximation for radiative transfer to calculate metastable and excited population densities via a collisional-radiative model. Population escape factor, emergent escape factor and modified line profiles are plotted vs. optical depth. The simulated emission line ratios in the density/temperature plane are in good agreement with experimental data for electron density and temperature measurements.

  15. Relaxing the Small Particle Approximation for Dust-grain opacities in Carbon-star Wind Models

    OpenAIRE

    Mattsson, Lars; Höfner, Susanne

    2010-01-01

    We have computed wind models with time-dependent dust formation and grain-size dependent opacities, where (1) the problem is simplified by assuming a fixed dust-grain size, and where (2) the radiation pressure efficiency is approximated using grain sizes based on various means of the actual grain size distribution. It is shown that in critical cases, the effect of grain sizes can be significant. For well-developed winds, however, the effects on the mass-loss rate and the wind speed are small.

  16. Atomic data base and the U.K.-U.S. opacity project

    Science.gov (United States)

    Pradhan, A. K.

    1988-08-01

    With the primary aim of calculating stellar envelope opacities, a joint international collaboration is under way for the calculation of basic atomic data for radiative processes: oscillator strengths, photoionization cross sections, energy levels, radiative damping constants (including line broadening). Atomic calculations have been completed for the first ten isoelectronic sequences, H-like to Ne-like, going up to iron, and work is in progress on the third and fourth row atoms and isosequences. The close-coupling approximation is employed throughout using a new version of the R-matrix method. Particular emphasis is placed on the detailed resolution of the autoionization structures in the bound-free continuum.

  17. CLINICAL OUTCOME OF PENETRATING KERATOPLASTY IN CORNEAL OPACITIES OF DIFFERENT AETIOLOGY- A CLINICAL STUDY

    Directory of Open Access Journals (Sweden)

    Dipak Bhuyan

    2017-01-01

    Full Text Available BACKGROUND Corneal transplantation or grafting is an operation in which abnormal corneal host tissue is replaced by healthy donor cornea. According to the World Health Organization (WHO, corneal diseases are among the major causes of vision loss and blindness in the world today after cataract and glaucoma. The aim of the study is to- 1. Evaluate the different aetiology of corneal opacity including active infective aetiology as indicated for penetrating keratoplasty. 2. Determine the clinical outcome of penetrating keratoplasty in relation to graft survival, graft rejection and peri-operative complications in different aetiology groups. 3. Determine the final visual outcome. MATERIALS AND METHODS Candidates for keratoplasty were selected from- 1. Eye Bank of Regional Institute of Ophthalmology (R.I.O. 2. R.I.O OPD. The study period was from September 2014 to August 2015. 30 cases were taken in the study. Descriptive statistics were applied to analyse the data wherever necessary. RESULTS 34.6±19.73 yrs. (mean±SD was the mean age at which transplants were done in the study. Out of total 30 cases, 13 (43.33% and 17 (56.66% were male and female, respectively. The different indications for penetrating keratoplasty are- Post ulcer corneal opacity in 14 cases (46.66%, posttraumatic corneal opacity 9 cases (30%, pseudophakic bullous keratopathy 4 cases (13.33%, corneal dystrophy in 2 cases (6.66% and non-healing corneal ulcer in 1 case (3.33%. 16 cases (53.33% showed clear graft till the last follow up while 11 (33.33% cases showed partially clear graft resulting in improved visual outcome while 3 cases (10.00% of the grafts were opaque due to graft failure. CONCLUSION The major indications for penetrating keratoplasty in this part of the world are post ulcer and posttraumatic corneal opacity and majority of them are illiterate agricultural workers who failed to get adequate treatment on time. Graft survival rate is high, which can be attributed to the

  18. Calculation of opacities and emissivities for carbon plasmas under NLTE and LTE conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gil, J.M.; Rodriguez, R.; Florido, R.; Rubiano, J.G.; Martel, P. [Las Palmas de Gran Canaria Univ., Dept. de Fisica (Spain); Sauvan, P. [Universidad Nacional de Educacion a Distancia, Dept. de Ingenieria Energetica, Madrid (Spain); Minguez, E. [Madrid Univ. Politecnica, Instituto de Fusion Nuclear-DENIM (Spain)

    2006-06-15

    We calculate different optical properties for carbon plasma in a wide range of temperatures and densities by using ATOM3R-OP code which has been recently developed. In this code we have implemented the rate equations, the Saha equation (for local thermodynamic equilibrium) and the coronal equilibrium model. We have calculated average ionizations, level populations, opacities and emissivities and we focus our study on the identification with our code of coronal equilibrium, non-local thermodynamic equilibrium and local thermodynamic equilibrium regions for this kind of plasma. Moreover, we analyse the differences in the optical properties when they are calculated in non-local thermodynamic equilibrium and local thermodynamic equilibrium. (authors)

  19. Fractography of glass

    CERN Document Server

    Tressler, Richard

    1994-01-01

    As the first major reference on glass fractography, contributors to this volume offer a comprehensive account of the fracture of glass as well as various fracture surface topography Contributors discuss optical fibers, glass containers, and flatglass fractography In addition, papers explore fracture origins; the growth of the original flaws of defects; and macroscopic fracture patterns from which fracture patterns evolve This volume is complete with photographs and schematics

  20. Diamond turning of glass

    Energy Technology Data Exchange (ETDEWEB)

    Blackley, W.S.; Scattergood, R.O.

    1988-12-01

    A new research initiative will be undertaken to investigate the critical cutting depth concepts for single point diamond turning of brittle, amorphous materials. Inorganic glasses and a brittle, thermoset polymer (organic glass) are the principal candidate materials. Interrupted cutting tests similar to those done in earlier research are Ge and Si crystals will be made to obtain critical depth values as a function of machining parameters. The results will provide systematic data with which to assess machining performance on glasses and amorphous materials

  1. Glass to contain wastes

    International Nuclear Information System (INIS)

    Moncouyoux, M.; Jacquet-Francillon, M.

    1994-01-01

    Here are the tables and figures presented during the conference on the glass to confine high level radioactive wastes: definition, fabrication, storage and disposal. The composition of glasses are detailed, their properties and the vitrification proceeding. The behaviour of these glasses in front of water, irradiation and heat are shown. The characteristics of parcels are given according to the radiation protection rule, ALARA principle, the concept of multi-barriers and the geological stability

  2. Glass microspheres for brachytherapy

    International Nuclear Information System (INIS)

    Prado, Miguel O.; Prastalo, Simon; Blaumann, Herman; Longhino, Juan M.; Repetto Llamazares, A.H.V.

    2007-01-01

    We developed the capacity to produce glass microspheres containing in their structure one or more radioactive isotopes useful for brachytherapy. We studied the various facts related with their production: (Rare earth) alumino silicate glass making, glass characterization, microspheres production, nuclear activation through (n,γ) nuclear reactions, mechanical characterization before and after irradiation. Corrosion tests in simulated human plasma and mechanical properties characterization were done before and after irradiation. (author) [es

  3. Silicate glasses. Chapter 1

    International Nuclear Information System (INIS)

    Lutze, W.

    1988-01-01

    This chapter is a survey of world-wide research and development efforts in nuclear waste glasses and its production technology. The principal glasses considered are silicate glasses which contain boron, i.e. borosilicate glass. A historical overview of waste form development programs in nine countries is followed by a summary of the design criteria for borosilicate glass compositions glass compositions. In the sections on glass properties the waste form is characterized in terms of potential alterations under the influence of heat, thermal gradients, radiation, aqueous solutions and combinations thereof. The topics are phase transformations, mechanical properties, radiation effects and chemical durability. The results from studies of volcanic glasses, as natural analogues for borosilicate nuclear waste glasses in order to verify predictions obtained from short-term tests in the laboratory, have been compiled in a special section on natural analogues. A special section on advanced vitrification techniques summarizes the various actual and potential processing schemes and describes the facilities. The literature has been considered until 1985. (author). 430 refs.; 68 figs.; 29 tabs

  4. Glass and vitrification

    International Nuclear Information System (INIS)

    Barton, J.L.; Vacher, R.; Moncouyoux, J.P.; Vernaz, E.

    1997-01-01

    Most glasses used as materials are oxides glasses that are produced by a quick quench of a liquid. Glasses are characterized by the absence of periodicity in the atomic arrangements, they do not have symmetries and do not present order over a long distance. This series of 4 short articles present: 1) the properties of glass and its industrial story, 2) the glass structure, 3) a forty years long story of glass as dies used to confine wastes and 4) the methodology used to study the behaviour of glass over very long periods of time. This methodology is based on 5 steps: 1) define and specify the material to study (the prediction of long term alteration of a material is nonsense unless you know well its initial properties), 2) identify all the alteration processes that are likely to happen, determine their kinetics and the influence of environmental parameters, 3) develop mathematical models in order to simulate long-term behaviour of glasses, 4) determine the release rates of the radionuclides confined in the glass, and 5) validate data and models, it is not possible to expect a complete validation of a model that will be extrapolated over tens of thousands of years, nevertheless some ways of validation can lead to a satisfactory level of confidence taking into account reasonable uncertainties. (A.C.)

  5. Characterization of glass and glass ceramic nuclear waste forms

    International Nuclear Information System (INIS)

    Lutze, W.; Borchardt, J.; De, A.K.

    1979-01-01

    Characteristics of solidified nuclear waste forms, glass and glass ceramic compositions and the properties (composition, thermal stability, crystallization, phase behavior, chemical stability, mechanical stability, and radiation effects) of glasses and glass ceramics are discussed. The preparation of glass ceramics may be an optional step for proposed vitrification plants if tailored glasses are used. Glass ceramics exhibit some improved properties with respect to glasses. The overall leach resistance is similar to that of glasses. An increased leach resistance may become effective for single radionuclides being hosted in highly insoluble crystal phases mainly when higher melting temperatures are applicable in order to get more leach resistant residual glass phases. The development of glass ceramic is going on. The technological feasibility is still to be demonstrated. The potential gain of stability when using glass ceramics qualifies the material as an alternative nuclear waste form

  6. Ground water

    International Nuclear Information System (INIS)

    Osmond, J.K.; Cowart, J.B.

    1982-01-01

    The subject is discussed under the headings: background and theory (introduction; fractionation in the hydrosphere; mobility factors; radioisotope evolution and aquifer classification; aquifer disequilibria and geochemical fronts); case studies (introduction; (a) conservative, and (b) non-conservative, behaviour); ground water dating applications (general requirements; radon and helium; radium isotopes; uranium isotopes). (U.K.)

  7. Ground water

    International Nuclear Information System (INIS)

    Osmond, J.K.; Cowart, J.B.

    1992-01-01

    The great variations in concentrations and activity ratios of 234 U/ 238 U in ground waters and the features causing elemental and isotopic mobility in the hydrosphere are discussed. Fractionation processes and their application to hydrology and other environmental problems such as earthquake, groundwater and aquifer dating are described. (UK)

  8. Structure change of soda-silicate glass by mechanical milling

    International Nuclear Information System (INIS)

    Iwao, M; Okuno, M

    2010-01-01

    Structure change of ground soda-silicate glass (SiO 2 -Na 2 O binary systems) was investigated using X-ray diffraction (XRD) and infrared spectroscopy. The measurement results were discussed comparison to that of SiO 2 glass. With increasing Na 2 O concentrations, the XRD intensity around 2θ = 22 0 decreased and the intensity around 32 0 increased. The intensity around 22 0 and 32 0 maybe attributed to SiO 2 glass structure unit and soda-silicate glass unit, respectively. The peaks of Na 2 CO 3 crystal for 2SiO 2 -Na 2 O glass were observed with increasing milling time. This crystallization was suggested that Na + ion on 2SiO 2 -Na 2 O glass surface connected CO 2 in air. The intensity around 22 0 and 32 0 decreased and the intensity around 30 0 increased with increasing milling time. These may indicate that SiO 2 glass structure unit and soda-silicate glass structure unit were mixed by milling. In addition, IR absorption band near v = 1100 cm -1 was separated to two bands near 940 cm -1 and 1070 cm -1 with increasing Na 2 O concentrations. The band near 940 cm -1 decreased and the band near 1070 cm -1 increased with increasing milling time. These spectra changes were suggested due to decrease of Na 2 O concentrations in 2SiO 2 -Na 2 O glass with Na 2 CO 3 crystallization.

  9. Digitisation of films and texture analysis for digital classification of pulmonary opacities

    International Nuclear Information System (INIS)

    Desaga, J.F.; Dengler, J.; Wolf, T.; Engelmann, U.; Scheppelmann, D.; Meinzer, H.P.

    1988-01-01

    The study aimed at evaluating the effect of different methods of digitisation of radiographic films on the digital classification of pulmonary opacities. Test sets from the standard of the International Labour Office (ILO) Classification of Radiographs of Pneumoconiosis were prepared by film digitsation using a scanning microdensitometer or a video digitiser based on a personal computer equipped with a real time digitiser board and a vidicon or a Charge Coupled Device (CCD) camera. Seven different algorithms were used for texture analysis resulting in 16 texture parameters for each region. All methods used for texture analysis were independent of the mean grey value level and the size of the image analysed. Classification was performed by discriminant analysis using the classes from the ILO classification. A hit ratio of at least 85% was achieved for a digitisation by scanner digitisation or the vidicon, while the corresponding results of the CCD camera were significantly less good. Classification by texture analysis of opacities of chest X-rays of pneumoconiosis digitised by a personal computer based video digitiser and a vidicon are of equal quality compared to digitisation by a scanning microdensitometer. Correct classification of 90% was achieved via the described statistical approach. (orig.) [de

  10. Design for LTE EOS and opacity experiments using supersonic radiation waves

    Science.gov (United States)

    Tierney, T. E.; Peterson, R. R.; Tierney, H. E.

    2007-11-01

    Opacity and EOS at 100-200 eV are important physical parameters in ICF experiments. We describe an experiment design that uses the supersonic propagation of hohlraum radiation in foams to isochorically heat samples. Laser and Z-pinch experiments frequently use 150 to 220-eV quasi-blackbody emission from hohlraums to drive physics experiments. A foam target encapsulated in a gold-wall cylinder is placed next to the hohlraum. The low density and opacity foam captures some hohlraum emission and generates a supersonically-propagating radiation wave. The material heated by the wave is cooler towards the high-albedo gold wall. Modeling and past measurements show that core regions of the foam have small thermal gradients. We place a small, thin sample (e.g., Al, Si, or Fe) in the thermally-uniform region. X-ray emission of tracers and the sample as well as quasi-continuum x-ray absorption will be measured using time-resolved x-ray spectroscopy. The foam's EOS can be measured to ±5% by blast waves with a well characterized drive. This experiment could use the OMEGA, Z-Beamlet, and/or ZR facilities to explore temperature-dependent conditions.

  11. A Protective Eye Shield for Prevention of Media Opacities during Small Animal Ocular Imaging

    Science.gov (United States)

    Bell, Brent A.; Kaul, Charles; Hollyfield, Joe G.

    2014-01-01

    Optical coherence tomography (OCT), scanning laser ophthalmoscopy (SLO) and other non-invasive imaging techniques are increasingly used in eye research to document disease-related changes in rodent eyes. Corneal dehydration is a major contributor to the formation of ocular opacities that can limit the repeated application of these techniques to individual animals. General anesthesia is usually required for imaging, which is accompanied by the loss of the blink reflex. As a consequence, the tear film cannot be maintained, drying occurs and the cornea becomes dehydrated. Without supplemental hydration, structural damage to the cornea quickly follows. Soon thereafter, anterior lens opacities can also develop. Collectively these changes ultimately compromise image quality, especially for studies involving repeated use of the same animal over several weeks or months. To minimize these changes, a protective shield was designed for mice and rats that prevent ocular dehydration during anesthesia. The eye shield, along with a semi-viscous ophthalmic solution, is placed over the corneas as soon as the anesthesia immobilizes the animal. Eye shields are removed for only the brief periods required for imaging and then reapplied before the fellow eye is examined. As a result, the corneal surface of each eye is exposed only for the time required for imaging. The device and detailed methods described here minimize the corneal and lens changes associated with ocular surface desiccation. When these methods are used consistently, high quality images can be obtained repeatedly from individual animals. PMID:25245081

  12. AKSES JENIS DOKUMEN PADA BASIS DATA TERPADU: SUATU TINJAUAN TERHADAP OPAC DI PDII-LIPI

    Directory of Open Access Journals (Sweden)

    Ade Kohar

    2012-07-01

    Full Text Available Integrated data base is a data base records bibliographic data of several types of document like textbook, periodicals, proceedings, research report, thesis, and article. Purposes of this study were to investigate document type description and searching strategy in integrated data base of online public access catalogs (OPAC in PDII-LIPI, and to know user opinion about that data base existence. It used observation and interviews to 100 data base users to collect data. Result of this study stated that document type description in OPAC was not indexed, so users couldn't do information searching of special type of document directly in the data base. There was only one method could be used to search information of special type of document. User could select it from some information records on the computer screen as the result of document title, author name or subject searching in the data base. This information access method was not efficient. So document type description and indexing was an important factor and should be done in information retrieval system using integrated data base. But respondent majority (84% in PDII-LIPI stated that they liked using separated data base to search information of special type of document.

  13. Constraining the Dust Opacity Law in Three Small and Isolated Molecular Clouds

    Energy Technology Data Exchange (ETDEWEB)

    Webb, K. A.; Thanjavur, K. [Department of Physics and Astronomy, 3800 Finnerty Road, University of Victoria, Victoria, BC, V8P 5C2 (Canada); Di Francesco, J. [National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada); Sadavoy, S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Launhardt, R.; Vicente, J. Abreu; Kainulainen, J. [Max-Planck-Institut für Astronomy, Königstuhl 17, D-69117, Heidelberg (Germany); Shirley, Y. [Steward Observatory, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Stutz, A., E-mail: kawebb@uvic.ca [Departmento de Astronomìa, Facultad Ciencias Físicas y Matemáticas, Universidad de Concepción, Av. Esteban Iturra s/n Barro Universitario, Casilla 160-C, Concepción (Chile)

    2017-11-01

    Density profiles of isolated cores derived from thermal dust continuum emission rely on models of dust properties, such as mass opacity, that are poorly constrained. With complementary measures from near-infrared extinction maps, we can assess the reliability of commonly used dust models. In this work, we compare Herschel -derived maps of the optical depth with equivalent maps derived from CFHT WIRCAM near-infrared observations for three isolated cores: CB 68, L 429, and L 1552. We assess the dust opacities provided from four models: OH1a, OH5a, Orm1, and Orm4. Although the consistency of the models differs between the three sources, the results suggest that the optical properties of dust in the envelopes of the cores are best described by either silicate and bare graphite grains (e.g., Orm1) or carbonaceous grains with some coagulation and either thin or no ice mantles (e.g., OH5a). None of the models, however, individually produced the most consistent optical depth maps for every source. The results suggest that either the dust in the cores is not well-described by any one dust property model, the application of the dust models cannot be extended beyond the very center of the cores, or more complex SED fitting functions are necessary.

  14. Lenticular opacities in proximally exposed A-bomb survivors and their lately significance

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, S [Sugimoto Ophthalmological Clinic, Hiroshima (Japan)

    1978-04-01

    Five cases of lenticular opacities in proximally exposed A-bomb survivors (not published yet) were reported with some slides. From these experiment cases, following items were investigated. Significance of A-bomb radiation cataracts: Because cataract is the first manifistation of delayed hazard to a human body caused by A-bomb radiation and can be observed still now, cataract is regarded to be very important for recognizing A-bomb hazard. The manifestation of these findings of cataract is the reason for strong appeals that A-bomb hazard is still existing. Clinical findings of lenticular opacities was searched with reference to the literature. Several findings in experiment cases were described, and the importance of the study about changes of clinical findings was mentioned. It was pointed out that radiation cataract is closely related to the loss of hair in acute atomic radiation hazard. In case of radiation cataract, some difference between right and left eye was sometimes observed. Studies concerning this difference should be further developed in future. The importance of the factors of shielding was pointed out.

  15. Third dredge-up in cluster AGB stars : observational constraints and improved opacity data for models

    International Nuclear Information System (INIS)

    Lederer, M. T.

    2009-01-01

    evolution calculations with our findings. The second part of the thesis deals with a new set of low-temperature mean opacity coefficients. Until recently, the change in chemistry due to the TDU in the cool layers of the star, where molecules are the dominant opacity source, has been neglected in almost all stellar evolution models. I show that already within a certain chemistry regime (i. e. an oxygen-rich or carbon-rich metal mixture) an alteration of the carbon abundance causes, due to the special role of the CO molecule, considerable changes in the Rosseland opacity which has distinct consequences for the stellar structure and evolution. In the stellar evolution models, the most pronounced effect can be expected when the TDU turns the initially oxygen-rich object into a carbon star. The new opacity database contains (beside a variation of the 12 C mass fraction) also tables with a varied abundance of 14 N. After describing the database as well as the tools and the data used for its computation, I point out the implications of the new opacity data for stellar evolution models. (author) [de

  16. Relaxations in spin glasses: Similarities and differences from ordinary glasses

    International Nuclear Information System (INIS)

    Ngai, K.L.; Rajagopal, A.K.; Huang, C.Y.

    1984-01-01

    Relaxation phenomena have become a major concern in the physics of spin glasses. There are certain resemblances of these relaxation properties to those of ordinary glasses. In this work, we compare the relaxation properties of spin glasses near the freezing temperature with those of glasses near the glass transition temperature. There are similarities between the two types of glasses. Moreover, the relaxation properties of many glasses and spin glasses are in conformity with two coupled ''universality'' relations predicted by a recent model of relaxations in condensed matter

  17. Evaluation of Structural Cellular Glass

    Science.gov (United States)

    Adams, M. A.; Zwissler, J. G.

    1984-01-01

    Preliminary design information presented. First report discusses state of structural-cellular-glass programs as of June 1979. Second report gives further details of program to develop improved cellular glasses and to characterize properties of glasses and commercially available materials.

  18. Performance of a buried radioactive high level waste (HLW) glass after 24 years

    International Nuclear Information System (INIS)

    Jantzen, Carol M.; Kaplan, Daniel I.; Bibler, Ned E.; Peeler, David K.; John Plodinec, M.

    2008-01-01

    A radioactive high level waste glass was made in 1980 with Savannah River Site (SRS) Tank 15 waste. This glass was buried in a lysimeter in the SRS burial ground for 24 years. Lysimeter leachate data was available for the first 8 years. The glass was exhumed in 2004. The glass was predicted to be very durable and laboratory tests confirmed this. Scanning electron microscopy of the glass burial surface showed no significant glass alteration consistent with results of other laboratory and field tests. Radionuclide profiling for alpha, beta, and 137 Cs indicated that Pu was not enriched in the soil while 137 Cs and 9 deg. C Sr were enriched in the first few centimeters surrounding the glass. Lysimeter leachate data indicated that 9 deg. C Sr and 137 Cs leaching from the glass was diffusion controlled

  19. Electric glass capturing markets

    Energy Technology Data Exchange (ETDEWEB)

    Wikman, K.; Wikstroem, T.

    1996-11-01

    Electric glass has found its place on the construction market. In public buildings, electrically heatable windows are becoming the leading option for large glass walls. Studies on detached houses, both new and renovated, show that floor heating combined with electrically heatable windowpanes is the best choice with respect to resident`s comfort. (orig.)

  20. Radioresistance of inorganic glasses

    International Nuclear Information System (INIS)

    Vorob'ev, A.A.; Zavadovskaya, E.K.; Fedorov, B.V.; Starodubtsev, V.A.

    1977-01-01

    Regularities are considered in the variation of properties of glass due to irradiations. On the basis of previous theoretical statements and experimental investigations, it is inferred that the irradiation resistance of glasses of the same type, synthesis conditions, content of impurities and amount of imperfections, is a function of the ''element-oxygen'' bond energy. The irradiation resistance depends on the number and the nature of glass structure imperfections. The averaged level of bonding forces is indicative of the glass formation temperature; the imperfections in glasses are formed in structure elements whose amount predominates as compared to the others. Electric charges which accumulate on the crack surface tend to increase its size, thus lessening even further the electric strength of the dielectric. The greater the irradiation time, the greater the number of irradiation imperfections causing a drop in the electric strength of glass. When choosing a glass for service in a radiation field, it is necessary to select those of a highest temperature of glass formation and with a least amount of imperfections

  1. Nucleation in ZBLAN glasses

    NARCIS (Netherlands)

    de Leede, G.L.A.; Waal, de H.

    1989-01-01

    Nucleation rates were detd. in a ZrF4-BaF2-NaF-LaF3-AlF3 glass (ZBLAN) using an optical method. The results were compared with a similar glass having a slightly different compn. The difference in the nucleation rate is explained by classical nucleation theory using calcd. free-energy differences

  2. Detection of artificial air space opacities with digital radiography. Ex vivo study on enhanced latitude post-processing

    International Nuclear Information System (INIS)

    Biederer, Juergen; Bolte, H.; Schmidt, T.; Charalambous, N.; Both, M.; Hoffmann, B.; Heller, M.; Kopp, U.; Freitag-Wolf, S.; Van Metter, R.

    2010-01-01

    Purpose: To evaluate in a.-p. digital chest radiograms of an ex vivo system if increased latitude and enhanced image detail contrast (EVP) improve the accuracy of detecting artificial air space opacities in parts of the lung that are superimposed by the diaphragm. Materials and Methods: 19 porcine lungs were inflated inside a chest phantom, prepared with 20-50 ml gelatin-stabilized liquid to generate alveolar air space opacities, and examined with direct radiography (3.0 x 2.5 k detector/125 kVp/4 mAs). 276 a.-p. images with and without EVP of 1.0-3.0 were presented to 6 observers. 8 regions were read for opacities, the reference was defined by CT. Statistics included sensitivity/specificity, interobserver variability, and calculation of Az (area under ROC curve). Results: Behind the diaphragm (opacities in 32/92 regions), the median sensitivity increased from 0.35 without EVP to 0.53 - 0.56 at EVP 1.5 - 3.0 (significant in 5/6 observers). The specificity decreased from 0.96 to 0.90 (significant in 6/6), and the Az value and interobserver correlation increased from 0.66 to 0.74 and 0.39 to 0.48, respectively. Above the diaphragm, the median sensitivity for artificial opacities (136/276 regions) increased from 0.71 to 0.77 - 0.82 with EVP (significant in 4/6 observers). The specificity and Az value decreased from 0.76 to 0.62 and 0.74 to 0.70, respectively, (significant in 3/6). Conclusion: In this ex vivo experiment, EVP improved the diagnostic accuracy for artificial air space opacities in the superimposed parts of the lung (area under the ROC curve). Above the diaphragm, the accuracy was not affected due to a tradeoff in sensitivity/specificity. (orig.)

  3. Propuesta metodológica de evaluación de interfaces de OPACs. INNOPAC versus UNICORN.

    Directory of Open Access Journals (Sweden)

    Rodríguez Bravo, Blanca

    2004-03-01

    Full Text Available The aim of this paper is to present a model of academic OPACs evaluation with the objective of sharing a procedure and some parameters and indicators established. There are two fundamental parameters, the interface searching services and the characteristics of the interface: design, ergonomics and user-friendliness. The present work provides also, the main results of the evaluations of ten OPACs implemented with INNOPAC and UNICORN previously accomplished. Now we will contrast both systems. We consider that universities are institutions that demand OPACs with better services to those of other informative units. The present evaluation has considered the users needs in academic libraries.

    Los propósitos de este trabajo son presentar un modelo de evaluación de OPACs universitarios con el objetivo de compartir un procedimiento y unos parámetros e indicadores establecidos a este fin. Dos son los parámetros fundamentales, las prestaciones de búsqueda de la interfaz y las características de la propia interfaz: diseño, ergonomía y amigabilidad. El presente estudio ofrece, asimismo, los principales resultados de las evaluaciones realizadas en trabajos previos sobre diez OPACs implementados con INNOPAC y UNICORN, que nos permiten ahora contrastar ambos sistemas. Partimos de la consideración de que las universidades son instituciones que por su idiosincrasia exigen OPACs con prestaciones superiores a las de otras unidades informativas. En este sentido, la formalización de los criterios evaluativos ha considerado las necesidades de los usuarios de las bibliotecas universitarias.

  4. Corrosion of ancient glass beads found in Southern Thailand

    International Nuclear Information System (INIS)

    Won-in, K; Thongkam, Y; Intarasiri, S; Kamwanna, T; Dararutana, P

    2012-01-01

    Glass has been used as ornaments and decorations in Thailand for several hundred years. The archaeological resources suggested that the ancient glass beads excavated in southern Thailand were made more than 1300 years ago. Initial findings revealed that there were number of difference in shade between the glass beads of difference colors. Energy dispersive X-ray spectrometer (EDS) system attached with scanning electron microscope (SEM) and particle-induced X-ray emission spectroscopy (PIXE) were firstly used to study the surface corrosion of the samples. SEM micrographs showed more corroded and flaked microstructure. These were contributed to the interaction of both the ground water and its dissolved chemical compounds.

  5. Mechanical relaxation in glasses

    International Nuclear Information System (INIS)

    Hiki, Y.

    2004-01-01

    The basic properties of glasses and the characteristics of mechanical relaxation in glasses were briefly reviewed, and then our studies concerned were presented. Experimental methods adopted were viscosity, internal friction, ultrasonic attenuation, and Brillouin scattering measurements. The specimens used were several kinds of inorganic, organic, and metallic glasses. The measurements were mainly carried out from the room temperature up to the glass transition temperature, and the relaxation time was determined as a function of temperature. The 'double relaxation' composed of two Arrhenius-type relaxations was observed in many materials. In both relaxations, the 'compensation effect' showing a correlation of the pre-exponential factor and the activation energy was observed. These results were explained by considering the 'complex relaxation' due to cooperative motions of atoms or group of atoms. Values of activation energy near the glass transition determined by the various experimental methods were compared with each other

  6. Polymorphism in glasses

    International Nuclear Information System (INIS)

    Landa, L.M.; Nikolaeva, I.N.

    1979-01-01

    To defect phase interfaces and spasmodic properties change, the inhomogeneity and the second radiation effects in quartz glass, metamict phase and intermediate states have been investigated. When irradiating with fast neutrons the transformation of quartz glass - metamict phase occurs completely. The transformation is completed at 2x10 20 part./cm 2 dose. Thermal treatment not only increases the number of inhomogeneities but also results in increasing quartz glass density. Annealing transforms the metamict phase into common quartz glass at 1400 K. The fact, that thermal treatment results in the complete transformation of metamict phase into quartz glass, and the inverse transformation occurs only partially, is quite regular, as the metamict phase has a lesser entropy and is a more ordered state. It is shown that different amorphous phases of a chemical composition have different structures and properties, that there are interfaces between them, and the transformation from one state to another in microvolumes is realized spasmodically and requires expenditure of energy

  7. Glass leaching performance

    International Nuclear Information System (INIS)

    Chick, L.A.; Turcotte, R.P.

    1983-05-01

    Current understanding of the leaching performance of high-level nuclear waste (HLW) glass is summarized. The empirical model of waste glass leaching behavior developed shows that at high water flow rates the glass leach rate is kinetically limited to a maximum value. At intermediate water flow rates, leaching is limited by the solution concentration of silica and decreases with decreasing water flow rates. Release of soluble elements is controlled by silica dissolution because silica forms the binding network of the glass. At low water flow rates, mass loss rates reach values controlled by formation rates of alteration minerals, or by diffusion of dissolution products through essentially stagnant water. The parameters reviewed with respect to their quantifiable influence on leaching behavior include temperature, pH, leachant composition, glass composition, thermal history, and radiation. Of these, temperature is most important since the rate of mass loss approximately doubles with each 10 0 C increase in dilute solutions. The pH has small effects within the 4 to 10 range. The chemical composition of the leachant is most important with regard to its influence on alteration product formation. Glass composition exhibits the largest effects at high flow rates where improved glasses leach from ten to thirty times slower than glass 76 to 68. The effects of the thermal history (devitrification) of the glass are not likely to be significant. Radiation effects are important primarily in that radiolysis can potentially drive pH values to less than 4. Radiation damage to the glass causes insignificant changes in leaching performance

  8. Ground Pollution Science

    International Nuclear Information System (INIS)

    Oh, Jong Min; Bae, Jae Geun

    1997-08-01

    This book deals with ground pollution science and soil science, classification of soil and fundamentals, ground pollution and human, ground pollution and organic matter, ground pollution and city environment, environmental problems of the earth and ground pollution, soil pollution and development of geological features of the ground, ground pollution and landfill of waste, case of measurement of ground pollution.

  9. Corrosion phenomena in electron, proton and synchrotron X-ray microprobe analysis of Roman glass from Qumran, Jordan

    Science.gov (United States)

    Janssens, K.; Aerts, A.; Vincze, L.; Adams, F.; Yang, C.; Utui, R.; Malmqvist, K.; Jones, K. W.; Radtke, M.; Garbe, S.; Lechtenberg, F.; Knöchel, A.; Wouters, H.

    1996-04-01

    A series of 89 glass fragments of Roman glass are studied using electron, proton and synchrotron radiation induced X-ray emission from microscopic areas on the sample surface. The glass originates from Qumran, Jordan and was buried for 1900 years. The weathering layers that result from the extended contact with ground water have been studied, next to the trace composition of the original glass of these pieces. The latter information indicates that at Qumran, large quantities of glass objects were being used in Ancient times. Cross-sectional profiles of the glass show a complex migration behaviour of various groups of major and trace elements.

  10. Ground calibration of DREAMS-H relative humidity device

    Science.gov (United States)

    Komu, M.; Genzer, M.; Nikkanen, T.; Schmidt, W.; Haukka, H.; Kemppinen, O.; Harri, A.-M.

    2014-04-01

    DREAMS (Dust Characterization, Risk Assessment and Environmental Analyzer on the Martian Surface) instrument suite is to be launched as part of ESA ExoMars 2016/Entry, Descent and Landing Demonstration Module (EDM). DREAMS consists of an environmental package for monitoring temperature, pressure, relative humidity, winds and dust opacity, as well as atmospheric electricity of Martian atmosphere. DREAMS instruments and scientific goals are described in [1]. Here we describe ground calibration of the relative humidity device, DREAMS-H, provided to DREAMS payload by Finnish Meteorological Institute and based on proprietary technology of Vaisala, Inc. Same kind of device is part of REMS instrument package onboard MSL Curiosity Rover [2][3].

  11. Corrosion of synthesized glasses and glazes as analogs for nuclear waste glass degradation

    International Nuclear Information System (INIS)

    Vandiver, P.B.

    1994-01-01

    Synthesized glasses provide an opportunity to study natural corrosion processes which are intermediate in time span between geological examples of natural glasses, such as obsidians and tektites, and relatively short term laboratory tests lasting a few hours to several decades. In addition, synthesized glasses can usually be tracked to particular archaeological find sites with known dates of production and often burial. Environmental conditions are routinely measured at archaeological sites as a part of the excavation-process, such that information is available on the yearly cycling of temperature and relative humidity, sometimes at the depth at which the artifact was found. Whether the artifacts were excavated in an air enclosure, such as a tomb, or in the soil can also be reconstructed, such that one can determine whether aqueous or atmospheric corrosion was involved in the degradation process. For instance, so-called open-quotes Roman glassclose quotes may span a time period of production of 800 years and a geographical range from Germany to North Africa and from Britain to Afghanistan. One example is the storage during World War II of glass from the British Museum in underground metro stations. Some of these glasses have been in collections for over 100 years. Thus, populations of glasses can be chosen for experimentation which compare variations in bulk composition, dopants, microstructure, heat treatment, ground vs. fire polished surfaces, aqueous vs. atmospheric corrosion, geographic, geological as well as recent storage conditions. Glasses in museums are generally considered to have had their corrosion arrested and be stable because changes in visual appearance are not obvious. However, if we attempt to measure the range of surface water content in these glasses using Fourier transform infrared analysis, a considerable variability is found, as shown

  12. Thermal Conductivity of Foam Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    Due to the increased focus on energy savings and waste recycling foam glass materials have gained increased attention. The production process of foam glass is a potential low-cost recycle option for challenging waste, e.g. CRT glass and industrial waste (fly ash and slags). Foam glass is used...... as thermal insulating material in building and chemical industry. The large volume of gas (porosity 90 – 95%) is the main reason of the low thermal conductivity of the foam glass. If gases with lower thermal conductivity compared to air are entrapped in the glass melt, the derived foam glass will contain...... only closed pores and its overall thermal conductivity will be much lower than that of the foam glass with open pores. In this work we have prepared foam glass using different types of recycled glasses and different kinds of foaming agents. This enabled the formation of foam glasses having gas cells...

  13. Effect of different glasses in glass bonded zeolite

    International Nuclear Information System (INIS)

    Lewis, M.A.; Ackerman, J.P.; Verma, S.

    1995-01-01

    A mineral waste form has been developed for chloride waste salt generated during the pyrochemical treatment of spent nuclear fuel. The waste form consists of salt-occluded zeolite powders bound within a glass matrix. The zeolite contains the salt and immobilizes the fission products. The zeolite powders are hot pressed to form a mechanically stable, durable glass bonded zeolite. Further development of glass bonded zeolite as a waste form requires an understanding of the interaction between the glass and the zeolite. Properties of the glass that enhance binding and durability of the glass bonded zeolite need to be identified. Three types of glass, boroaluminosilicate, soda-lime silicate, and high silica glasses, have a range of properties and are now being investigated. Each glass was hot pressed by itself and with an equal amount of zeolite. MCC-1 leach tests were run on both. Soda-lime silicate and high silica glasses did not give a durable glass bonded zeolite. Boroaluminosilicate glasses rich in alkaline earths did bind the zeolite and gave a durable glass bonded zeolite. Scanning electron micrographs suggest that the boroaluminosilicate glasses wetted the zeolite powders better than the other glasses. Development of the glass bonded zeolite as a waste form for chloride waste salt is continuing

  14. Oxynitride glasses: a review

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, A.R.; Clausell, C.; Barba, A.

    2016-07-01

    Oxynitride glasses are special types of silicates or silicoaluminates which have been the object of many studies over the last forty years. They can be prepared by means of various complex methods, leading to variable levels of nitrogen incorporation, though in all cases giving limited transparency in the visible range. More recently, a new family of oxynitride glasses incorporating fluorine has been investigated. This paper outlines the effect of composition, in particular nitrogen and fluorine content, on properties such as glass transition temperature, hardness, Young's modulus, compactness and molar volume. (Author)

  15. Orbital glass in HTSC

    International Nuclear Information System (INIS)

    Kusmartsev, F.V.

    1992-10-01

    The physical reasons why the orbital glass may exist in granular high-temperature superconductors and the existing experimental data appeared recently are discussed. The orbital glass is characterized by the coexistence of the orbital paramagnetic state with the superconducting state and occurs at small magnetic fields H c0 c1 . The transition in orbital glass arises at the critical field H c0 which is inversely proportional to the surface cross-area S of an average grain. In connection with theoretical predictions the possible experiments are proposed. (author). 10 refs

  16. Bioactive glasses and glass-ceramics

    Directory of Open Access Journals (Sweden)

    de Aza, P. N.

    2007-04-01

    Full Text Available Since the late 1960´s, a great interest in the use of bioceramic materials for biomedical applications has been developed. In a previous paper, the authors reviewed crystalline bioceramic materials “sensus stricto”, it is to say, those ceramic materials, constituted for non-metallic inorganic compounds, crystallines and consolidates by thermal treatment of powders at high temperature. In the present review, the authors deal with those called bioactive glasses and glassceramics. Although all of them are also obtained by thermal treatment at high temperature, the first are amorphous and the second are obtained by devitrification of a glass, although the vitreous phase normally prevails on the crystalline phases. After an introduction to the concept of bioactive materials, a short historical review of the bioactive glasses development is made. Its preparation, reactivity in physiological media, mechanism of bonding to living tissues and mechanical strength of the bone-implant interface is also reported. Next, the concept of glass-ceramic and the way of its preparation are exposed. The composition, physicochemical properties and biological behaviour of the principal types of bioactive glasses and glass-ceramic materials: Bioglass®, Ceravital®, Cerabone®, Ilmaplant® and Bioverit® are also reviewed. Finally, a short review on the bioactive-glass coatings and bioactive-composites and most common uses of bioactive-glasses and glass-ceramics are carried out too.

    Desde finales de los años sesenta, se ha despertado un gran interés por el uso de los materiales biocerámicos para aplicaciones biomédicas. En un trabajo previo, los autores hicieron una revisión de los denominados materiales biocerámicos cristalinos en sentido estricto, es decir, de aquellos materiales, constituidos por compuestos inorgánicos no metálicos, cristalinos y consolidados mediante tratamientos térmicos a altas temperaturas. En el presente trabajo, los autores

  17. Model Stellar Atmospheres and Real Stellar Atmospheres and Status of the ATLAS12 Opacity Sampling Program and of New Programs for Rosseland and for Distribution Function Opacity

    Science.gov (United States)

    Kurucz, Robert L.

    1996-01-01

    I discuss errors in theory and in interpreting observations that are produced by the failure to consider resolution in space, time, and energy. I discuss convection in stellar model atmospheres and in stars. Large errors in abundances are possible such as the factor of ten error in the Li abundance for extreme Population II stars. Finally I discuss the variation of microturbulent velocity with depth, effective temperature, gravity, and abundance. These variations must be dealt with in computing models and grids and in any type of photometric calibration. I have also developed a new opacity-sampling version of my model atmosphere program called ATLAS12. It recognizes more than 1000 atomic and molecular species, each in up to 10 isotopic forms. It can treat all ions of the elements up through Zn and the first 5 ions of heavier elements up through Es. The elemental and isotopic abundances are treated as variables with depth. The fluxes predicted by ATLAS12 are not accurate in intermediate or narrow bandpass intervals because the sample size is too small. A special stripped version of the spectrum synthesis program SYNTHE is used to generate the surface flux for the converged model using the line data on CD-ROMs 1 and 15. ATLAS12 can be used to produce improved models for Am and Ap stars. It should be very useful for investigating diffusion effects in atmospheres. It can be used to model exciting stars for H II regions with abundances consistent with those of the H II region. These programs and line files will be distributed on CD-ROMs.

  18. Communication grounding facility

    International Nuclear Information System (INIS)

    Lee, Gye Seong

    1998-06-01

    It is about communication grounding facility, which is made up twelve chapters. It includes general grounding with purpose, materials thermal insulating material, construction of grounding, super strength grounding method, grounding facility with grounding way and building of insulating, switched grounding with No. 1A and LCR, grounding facility of transmission line, wireless facility grounding, grounding facility in wireless base station, grounding of power facility, grounding low-tenton interior power wire, communication facility of railroad, install of arrester in apartment and house, install of arrester on introduction and earth conductivity and measurement with introduction and grounding resistance.

  19. The Next Generation Library Catalog: A Comparative Study of the OPACs of Koha, Evergreen, and Voyager

    Directory of Open Access Journals (Sweden)

    Sharon Q. Yang

    2010-09-01

    Full Text Available Open source has been the center of attention in the library world for the past several years. Koha and Evergreen are the two major open-source integrated library systems (ILSs, and they continue to grow in maturity and popularity. The question remains as to how much we have achieved in open-source development toward the next-generation catalog compared to commercial systems. Little has been written in the library literature to answer this question. This paper intends to answer this question by comparing  the next-generation features of the OPACs of two open-source ILSs (Koha and Evergreen and one proprietary ILS (Voyager’s WebVoyage.

  20. Opacity and Transport Measurements Reveal That Dilute Plasma Models of Sonoluminescence Are Not Valid

    Science.gov (United States)

    Khalid, Shahzad; Kappus, Brian; Weninger, Keith; Putterman, Seth

    2012-03-01

    A strong interaction between a nanosecond laser and a 70 μm radius sonoluminescing plasma is achieved. The overall response of the system results in a factor of 2 increase in temperature as determined by its spectrum. Images of the interaction reveal that light energy is absorbed and trapped in a region smaller than the sonoluminescence emitting region of the bubble for over 100 ns. We interpret this opacity and transport measurement as demonstrating that sonoluminescencing bubbles can be 1000 times more opaque than what follows from the Saha equation of statistical mechanics in the ideal plasma limit. To address this discrepancy, we suggest that the effects of strong Coulomb interactions are an essential component of a first principles theory of sonoluminescence.

  1. 1st oPAC Topical Workshop: Grand Challenges in Accelerator Optimisation

    CERN Document Server

    2013-01-01

    Accelerators are key instruments for fundamental research, health and industry applications. International collaboration is very important for their continued optimisation. To address this oPAC is organising this two-day international workshop on Grand Challenges in Accelerator Optimisation. The workshop will provide an overview of the current state of the art in beam physics, numerical simulations and beam instrumentation and highlight existing limitations. It will discuss research and development being undertaken and ambitions to further improve the performance of existing and future facilities. In addition to invited talks, there will be industry displays and a special seminar covering recent LHC discoveries. All participants will have an opportunity to contribute a poster.

  2. Conceptual design of initial opacity experiments on the national ignition facility

    Energy Technology Data Exchange (ETDEWEB)

    Heeter, R.  F.; Bailey, J.  E.; Craxton, R.  S.; DeVolder, B.  G.; Dodd, E.  S.; Garcia, E.  M.; Huffman, E.  J.; Iglesias, C.  A.; King, J.  A.; Kline, J.  L.; Liedahl, D.  A.; McKenty, P.  W.; Opachich, Y.  P.; Rochau, G.  A.; Ross, P.  W.; Schneider, M.  B.; Sherrill, M.  E.; Wilson, B.  G.; Zhang, R.; Perry, T.  S.

    2017-01-09

    Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative–convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperatures${\\geqslant}150$ eV and electron densities${\\geqslant}7\\times 10^{21}~\\text{cm}^{-3}$. The iron will be probed using continuum X-rays emitted in a${\\sim}200$ ps,${\\sim}200~\\unicode[STIX]{x03BC}\\text{m}$diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design

  3. New constraints on Lyman-α opacity using 92 quasar lines of sight

    Science.gov (United States)

    Bosman, Sarah E. I.; Fan, Xiaohui; Jiang, Linhua; Reed, Sophie; Matsuoka, Yoshiki; Becker, George; Rorai, Albert

    2018-05-01

    The large scatter in Lyman-α opacity at z > 5.3 has been an ongoing mystery, prompting a flurry of numerical models. A uniform ultra-violet background has been ruled out at those redshifts, but it is unclear whether any proposed models produce sufficient inhomogeneities. In this paper we provide an update on the measurement which first highlighted the issue: Lyman-α effective optical depth along high-z quasar lines of sight. We nearly triple on the previous sample size in such a study thanks to the cooperation of the DES-VHS, SHELLQs, and SDSS collaborations as well as new reductions and spectra. We find that a uniform UVB model is ruled out at 5.1 < z < 5.3, as well as higher redshifts, which is perplexing. We provide the first such measurements at z ~ 6. None of the numerical models we confronted to this data could reproduce the observed scatter.

  4. The Interplay of Opacities and Rotation in Promoting the Explosion of Core-Collapse Supernovae

    Science.gov (United States)

    Vartanyan, David; Burrows, Adam; Radice, David

    2018-01-01

    For over five decades, the mechanism of explosion in core-collapse supernovae has been a central unsolved problem in astrophysics, challenging both our computational capabilities and our understanding of relevant physics. Current simulations often produce explosions, but they are at times underenergetic. The neutrino mechanism, wherein a fraction of emitted neutrinos is absorbed in the mantle of the star to reignite the stalled shock, remains the dominant model for reviving explosions in massive stars undergoing core collapse. We present here a diverse suite of 2D axisymmetric simulations produced by FORNAX, a highly parallelizable multidimensional supernova simulation code. We explore the effects of various corrections, including the many-body correction, to neutrino-matter opacities and the possible role of rotation in promoting explosion amongst various core-collapse progenitors.

  5. Lethality Index 2008-2014: Less shootings, same lethality, more opacity

    Directory of Open Access Journals (Sweden)

    Carlos Silva Forné

    2017-11-01

    Full Text Available This article evaluates the use of lethal force by Mexican federal security forces during shootings with presumed members of organized crime from 2008-2014. The authors use official data and press reports on deaths and wounded in shootings to construct indicators such as the number of dead civilians over the number of dead officials from the federal security forces and the number of dead civilians over the number of wounded civilians. In a context where certain factors that contribute to an excessive use of force become more common, the results of the study show a growing use of lethal force. This raises questions over the possible excessive use of lethal force as a normal or systematic practice. The study also shows a growing context of opacity in the information available to evaluate the use of lethal force and the general lack of a legal framework to regulate the use of lethal force in Mexico.

  6. Repeatability of pachymetric mapping using fourier domain optical coherence tomography in corneas with opacities.

    Science.gov (United States)

    Samy El Gendy, Nehal M; Li, Yan; Zhang, Xinbo; Huang, David

    2012-04-01

    To evaluate the repeatability of Fourier domain optical coherence tomography (OCT) pachymetric mapping in patients with corneal opacities and to assess the reliability of Fourier domain OCT with 830 nm wavelength as a pachymetric measurement tool in opaque corneas. A Fourier domain OCT system was used to map the corneal thickness of patients with corneal scars or dystrophy. A retrospective study of a consecutive series was conducted. The repeatability was measured using pooled standard deviation of repeated measurements. A slit-scanning tomography device provided pachymetric mapping for comparison. Seventeen eyes of 12 patients with corneal scars (7 trauma and 3 post infection) or dystrophy (2 Reis-Bucklers and 5 granular dystrophy) were included. The posterior corneal boundary was detectable in all cases. The average corneal thickness measured by OCT was 536 ± 89 μm in central 2 mm area, 553 ± 76 μm in pericentral 2- to 5-mm area, and 508 ± 93 μm for the minimum corneal thickness. The slit-scanning tomography central corneal thickness, 433 ± 111 μm, was significantly lower than OCT readings (mean difference -91.1 ± 33.3 μm, P = 0.002). Repeatability of the OCT measurements was 2.1 μm centrally and 1.2 μm pericentrally. Pachymetric mapping with Fourier domain OCT was highly repeatable. Fourier domain OCT is a reliable pachymetric tool in opaque corneas. In comparison, corneal thickness measured by the slit-scanning tomography is significantly thinner than those measured by the Fourier domain OCT in the presence of corneal opacities.

  7. Lens Opacity and Hydrogen Sulfide in a New Zealand Geothermal Area.

    Science.gov (United States)

    Bates, Michael N; Bailey, Ian L; DiMartino, Robert B; Pope, Karl; Crane, Julian; Garrett, Nick

    2017-04-01

    Hydrogen sulfide (H2S) is a highly toxic gas with well-established, acute irritation effects on the eye. The population of Rotorua, New Zealand, sited on an active geothermal field, has some of the highest ambient H2S exposures in the world. Evidence from ecological studies in Rotorua has suggested that H2S is associated with cataract. The purpose of the present study was, using more detailed exposure characterization, clinical examinations, and anterior eye photography, to more directly investigate this previously reported association. Enrolled were 1637 adults, ages 18 to 65, from a comprehensive Rotorua primary care medical register. Patients underwent a comprehensive ophthalmic examination, including pupillary dilation and lens photography to capture evidence of any nuclear opacity, nuclear color, and cortical and posterior subcapsular opacity. Photographs were scored for all four outcomes on the LOCS III scale with decimalized interpolation between the exemplars. H2S exposure for up to the last 30 years was estimated based on networks of passive samplers set out across Rotorua and knowledge of residential, workplace, and school locations over the 30 years. Data analysis using linear and logistic regression examined associations between the degree of opacification and nuclear color or cataract (defined as a LOCS III score ≥2.0) in relation to H2S exposure. No associations were found between estimated H2S exposures and any of the four ophthalmic outcome measures. Overall, results were generally reassuring. They provided no evidence that H2S exposure at the levels found in Rotorua is associated with cataract. The previously found association between cataract and H2S exposure in the Rotorua population seems likely to be attributable to the limitations of the ecological study design. These results cannot rule out the possibility of an association with cataract at higher levels of H2S exposure.

  8. Effect of resin shades on opacity of ceramic veneers and polymerization efficiency through ceramics.

    Science.gov (United States)

    Öztürk, Elif; Chiang, Yu-Chih; Coşgun, Erdal; Bolay, Şükran; Hickel, Reinhard; Ilie, Nicoleta

    2013-11-01

    The aim of this study was to assess the effect of different resin cement shades on the opacity and color difference of ceramics and to determine the polymerization efficiency of the resin cement at different shades after curing through ceramics. Two different ceramics (IPS e.max Press and IPS Empress(®)CAD, Ivoclar Vivadent) were used for this study. A light-cured veneer luting resin (Variolink Veneer, Ivoclar Vivadent) in four different shades of HV+1, HV+3, LV-1, and LV-3 was used for the colorimetric measurements. The color and spectral reflectance of the ceramics were measured according to the CIELab color scale relative to the standard illuminant D65 on a reflection spectrophotometer (ColorEye7000A, USA). Color differences (ΔE values) and the contrast ratios (CR) of the different groups of samples were calculated. In order to analyse the polymerization efficiency of the resin cements, the micromechanical properties of the resins were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). The results were analysed using one-way ANOVA and Tukey's HSD post hoc tests (SPSS 18.0). The one-way ANOVA test showed that the values of ΔE and CR of the different specimen groups were significantly different (p<0.05). Group 1 (20.7 ± 0.5) (IPS-CAD without resin cement) exhibited the highest and group 10 (14.8 ± 0.5) (e.max:HV+3) exhibited the lowest ΔE value. Significant differences in the micromechanical properties were identified among the tested resin cements in different shades (p<0.05). Resin cement shade is an important factor for the opacity of a restoration. Furthermore, the resin shade affects the micromechanical properties of the underlying resin cement. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Low temperature sintering of fluorapatite glass-ceramics

    Science.gov (United States)

    Denry, Isabelle; Holloway, Julie A.

    2014-01-01

    Fluorapatite glass-ceramics have been shown to be excellent candidates as scaffold materials for bone grafts, however, scaffold production by sintering is hindered by concurrent crystallization of the glass. Our goal was to investigate the effect of Ca/Al ratio on the sintering behavior of Nb-doped fluorapatite-based glasses in the SiO2-Al2O3-P2O5-MgO-Na2O-K2O-CaO-CaF2 system. Glass compositions with Ca/Al ratio of 1 (A), 2 (B), 4 (C) and 19 (D) were prepared by twice melting at 1525°C for 3h. Glasses were either cast as cylindrical ingots or ground into powders. Disc-shaped specimens were prepared by either sectioning from the ingots or powder-compacting in a mold, followed by heat treatment at temperatures ranging between 700 and 1050°C for 1h. The density was measured on both sintered specimens and heat treated discs as controls. The degree of sintering was determined from these measurements. XRD showed that fluorapatite crystallized in all glass-ceramics. A high degree of sintering was achieved at 775°C for glass-ceramic D (98.99±0.04%), and 900°C for glass-ceramic C (91.31±0.10). Glass-ceramics A or B were only partially sintered at 1000°C (63.6±0.8% and 74.1±1.5%, respectively). SEM revealed a unique microstructure of micron-sized spherulitic fluorapatite crystals in glass-ceramics C and D. Increasing the Ca/Al ratio promoted low temperature sintering of fluorapatite glass-ceramics, which are traditionally difficult to sinter. PMID:24252652

  10. Low temperature sintering of fluorapatite glass-ceramics.

    Science.gov (United States)

    Denry, Isabelle; Holloway, Julie A

    2014-02-01

    Fluorapatite glass-ceramics have been shown to be excellent candidates as scaffold materials for bone grafts, however, scaffold production by sintering is hindered by concurrent crystallization of the glass. Objective, our goal was to investigate the effect of Ca/Al ratio on the sintering behavior of Nb-doped fluorapatite-based glasses in the SiO2-Al2O3-P2O5-MgO-Na2O-K2O-CaO-CaF2 system. Methods, glass compositions with Ca/Al ratio of 1 (A), 2 (B), 4 (C) and 19 (D) were prepared by twice melting at 1525°C for 3h. Glasses were either cast as cylindrical ingots or ground into powders. Disk-shaped specimens were prepared by either sectioning from the ingots or powder-compacting in a mold, followed by heat treatment at temperatures ranging between 700 and 1050°C for 1h. The density was measured on both sintered specimens and heat treated discs as controls. The degree of sintering was determined from these measurements. Results and Significance XRD showed that fluorapatite crystallized in all glass-ceramics. A high degree of sintering was achieved at 775°C for glass-ceramic D (98.99±0.04%), and 900°C for glass-ceramic C (91.31±0.10). Glass-ceramics A or B were only partially sintered at 1000°C (63.6±0.8% and 74.1±1.5%, respectively). SEM revealed a unique microstructure of micron-sized spherulitic fluorapatite crystals in glass-ceramics C and D. Increasing the Ca/Al ratio promoted low temperature sintering of fluorapatite glass-ceramics, which are traditionally difficult to sinter. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  11. Corneal Opacity in Domestic Ducks Experimentally Infected With H5N1 Highly Pathogenic Avian Influenza Virus.

    Science.gov (United States)

    Yamamoto, Y; Nakamura, K; Yamada, M; Mase, M

    2016-01-01

    Domestic ducks can be a key factor in the regional spread of H5N1 highly pathogenic avian influenza (HPAI) virus in Asia. The authors performed experimental infections to examine the relationship between corneal opacity and H5N1 HPAI virus infection in domestic ducks (Anas platyrhyncha var domestica). A total of 99 domestic ducks, including 3 control birds, were used in the study. In experiment 1, when domestic ducks were inoculated intranasally with 2 H5N1 HPAI viruses, corneal opacity appeared more frequently than neurologic signs and mortality. Corneal ulceration and exophthalmos were rare findings. Histopathologic examinations of the eyes of domestic ducks in experiment 2 revealed that corneal opacity was due to the loss of corneal endothelial cells and subsequent keratitis with edema. Influenza viral antigen was detected in corneal endothelial cells and some other ocular cells by immunohistochemistry. Results suggest that corneal opacity is a characteristic and frequent finding in domestic ducks infected with the H5N1 HPAI virus. Confirming this ocular change may improve the detection rate of infected domestic ducks in the field. © The Author(s) 2015.

  12. 40 CFR 60.1450 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

    Science.gov (United States)

    2010-07-01

    ... curtain incinerators that burn 100 percent yard waste? 60.1450 Section 60.1450 Protection of Environment... Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1450 How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste? (a) Use EPA Reference Method 9 in appendix A of...

  13. 40 CFR 60.1925 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

    Science.gov (United States)

    2010-07-01

    ... curtain incinerators that burn 100 percent yard waste? 60.1925 Section 60.1925 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1925 How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste? (a) Use...

  14. 40 CFR 62.15380 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

    Science.gov (United States)

    2010-07-01

    ... curtain incinerators that burn 100 percent yard waste? 62.15380 Section 62.15380 Protection of Environment... Combustion Units Constructed on or Before August 30, 1999 Air Curtain Incinerators That Burn 100 Percent Yard Waste § 62.15380 How must I monitor opacity for air curtain incinerators that burn 100 percent yard...

  15. Opacplot2: Enabling tabulated EoS and opacity compatibility for HEDLP simulations with the FLASH code

    Science.gov (United States)

    Laune, Jordan; Tzeferacos, Petros; Feister, Scott; Fatenejad, Milad; Yurchak, Roman; Flocke, Norbert; Weide, Klaus; Lamb, Donald

    2017-10-01

    Thermodynamic and opacity properties of materials are necessary to accurately simulate laser-driven laboratory experiments. Such data are compiled in tabular format since the thermodynamic range that needs to be covered cannot be described with one single theoretical model. Moreover, tabulated data can be made available prior to runtime, reducing both compute cost and code complexity. This approach is employed by the FLASH code. Equation of state (EoS) and opacity data comes in various formats, matrix-layouts, and file-structures. We discuss recent developments on opacplot2, an open-source Python module that manipulates tabulated EoS and opacity data. We present software that builds upon opacplot2 and enables easy-to-use conversion of different table formats into the IONMIX format, the native tabular input used by FLASH. Our work enables FLASH users to take advantage of a wider range of accurate EoS and opacity tables in simulating HELP experiments at the National Laser User Facilities.

  16. "Garbage" In, "Refuse and Refuse Disposal" Out: Making the Most of the Subject Authority File in OPAC.

    Science.gov (United States)

    Horn, Marguerite E.

    2002-01-01

    Discusses the difference in subject access in OPACs (online public access catalogs) between subject searching (authority, alphabetic, or controlled vocabulary) versus keyword searching (uncontrolled, free text, natural language vocabulary). Compares a query on the term "garbage" in two online catalogs and discusses results. (Author/LRW)

  17. Fun with Singing Wine Glasses

    Science.gov (United States)

    Boone, Christine; Galloway, Melodie; Ruiz, Michael J.

    2018-01-01

    A fun activity is presented using singing wine glasses for introductory physics students. Students tune a white wine glass and a red wine glass to as many semitones as possible by filling the glasses with the appropriate amounts of water. A smart phone app is used to measure the frequencies of equal-temperament tones. Then plots of frequency…

  18. Waste glass weathering

    International Nuclear Information System (INIS)

    Bates, J.K.; Buck, E.C.

    1994-01-01

    The weathering of glass is reviewed by examining processes that affect the reaction of commercial, historical, natural, and nuclear waste glass under conditions of contact with humid air and slowly dripping water, which may lead to immersion in nearly static solution. Radionuclide release data from weathered glass under conditions that may exist in an unsaturated environment are presented and compared to release under standard leaching conditions. While the comparison between the release under weathering and leaching conditions is not exact, due to variability of reaction in humid air, evidence is presented of radionuclide release under a variety of conditions. These results suggest that both the amount and form of radionuclide release can be affected by the weathering of glass

  19. Super ionic conductive glass

    Science.gov (United States)

    Susman, S.; Volin, K.J.

    Described is an ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A/sub 1 + x/D/sub 2-x/3/Si/sub x/P/sub 3 - x/O/sub 12 - 2x/3/, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

  20. Phosphate glasses, containing nitrogen

    International Nuclear Information System (INIS)

    Lisitsyna, E.A.; Khalilev, V.D.; Koryavin, A.A.; Goncharova, L.N.

    1987-01-01

    Possibilities of nitrogen-containing glass synthesis by the introduction into the charge of ammonium salts, as well as aluminium nitride, are studied. Zinc alumoyttrium phosphate glass (mol. %) Zn(PO 3 ) 2 - 4O, Al(PO 3 ) 3 - 3O, Y(PO 3 ) 3 -3O is suggested as a matrix. It is shown that the effect of amide and imide groups on the properties of the glass is less noticeable than the effect of nitride groups. Direct introduction of nitride constituent was realized using AlN, but aluminium introduction was taken into account so that the oxide was subtracted. The attempt to introduce more than 2.5 mass % of nitrogen into initial matrix by aluminium nitride has failed due to repeated restoration of glass with amorphous phosphorus isolation

  1. Baseline LAW Glass Formulation Testing

    International Nuclear Information System (INIS)

    Kruger, Albert A.; Mooers, Cavin; Bazemore, Gina; Pegg, Ian L.; Hight, Kenneth; Lai, Shan Tao; Buechele, Andrew; Rielley, Elizabeth; Gan, Hao; Muller, Isabelle S.; Cecil, Richard

    2013-01-01

    The major objective of the baseline glass formulation work was to develop and select glass formulations that are compliant with contractual and processing requirements for each of the LAW waste streams. Other objectives of the work included preparation and characterization of glasses with respect to the properties of interest, optimization of sulfate loading in the glasses, evaluation of ability to achieve waste loading limits, testing to demonstrate compatibility of glass melts with melter materials of construction, development of glass formulations to support ILAW qualification activities, and identification of glass formulation issues with respect to contract specifications and processing requirements

  2. High resolution CT findings of pleuropulmonary lnvolvement in systemic lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kun Sik; Kim, Jung Sik; Suh, Soo Jhi; Lee, Sung Moon; Sohn, Seok Ho; Park, Sung Bae; Kim, Hyun Chul [Keimyung University College of Medicine, Deagu (Korea, Republic of)

    1993-09-15

    To evaluate the high resolution computed tomography (HRCT) findings of pleuropulmonary involvement in systemic lupus erythematosus (SLE), we analyzed HRCT findings of 12 patients of clinically confirmed SLE with respiratory symptoms. In four patients, HRCT findings before and after chemotherapy were compared. The common HRCT findings were ground glass opacity (100%), bronchial wall thickening (66%), patch parenchymal opacity (58%), septal or intralobular line thickening (58%), micronodule (58%), central core prominence (41%), small pleural effusion (91%), and pericardial effusion (33%). Follow up HRCT obtained after treatment showed significant improvement of pleural effusion (4/4), pericardial effusion (3/3), pericardial thickening (1/1), patch opacity (2/2), and ground glass opacity (2/4). But bronchial wall thickening (2/2) and micronodule (2/2) were not improved. Although there are no pathognomonic HRCT findings in SLE, bilateral small pleural effusion, ground glass opacity, subpleural patchy opacity, and micronodule are common and suggestive findings in the pleuropulmonary involvement of SLE.

  3. Influence of the sintering temperature in the microstructure of foam glass obtained from waste glass

    International Nuclear Information System (INIS)

    Pokorny, A.; Vicenzi, J.; Bergmann, C.P.

    2012-01-01

    In this work, foam glasses were produced from grounded soda-lime glass and a synthetic carbonate, used as a foaming agent, with a similar composition to a dolomite lime, added with different oxides (SiO 2 , Al 2 O 3 , Fe 2 O 3 , MnO 2 , Na 2 O, K 2 O, TiO 2 and P 2 O 5 ). The objective was to evaluate the influence of sintering temperature on the properties and microstructure of the obtained material. In addition, the effect of addition of the oxides in the expansion of the ceramic bodies was evaluated. The ceramic bodies were formulated with 3 weight percent of synthetic carbonate, uniaxially pressed and fired within the temperature range from 700 deg C to 950 deg C, with a heating rate of 150K/h. The technological characterization of the ceramic bodies involved the determination of the volumetric expansion and their microstructures have been characterized by optical microscopy and scanning electron microscopy. The experimental results have shown foam glass can be obtained from grounded soda-lime glass, using synthetic carbonate, with the introduction of the different oxides, as foaming agent. (author)

  4. Waste glass as partial mineral precursor in alkali-activated slag/fly ash system

    NARCIS (Netherlands)

    Zhang, S.; Keulen, A.; Arbi, K.; Ye, G.

    2017-01-01

    The feasibility of a waste glass powder residue (GP) from glass recycling as partial mineral precursor to produce alkali-activated materials is investigated. GP served as powder coal fly ash (PCFA) replacement within a reference system composed of 50% PCFA and 50% ground granulated blast furnace

  5. Development of aluminosilicate and borosilicate glasses as matrices for CANDU high-level waste

    International Nuclear Information System (INIS)

    Strathdee, G.G.; McIntyre, N.S.; Taylor, P.

    1979-01-01

    This paper covers the results of analyses of two radioactive nepheline syenite glass blocks recovered from in-ground leaching experiments at the Chalk River Nuclear Laboratories. Current research on borosilicate glasses for immobilization of high-level waste is also described

  6. Improvement of chronic corneal opacity in ocular surface disease with prosthetic replacement of the ocular surface ecosystem (PROSE) treatment.

    Science.gov (United States)

    Cressey, Anna; Jacobs, Deborah S; Remington, Crystal; Carrasquillo, Karen G

    2018-06-01

    To demonstrate clearing of chronic corneal opacities and improvement of visual acuity with the use of BostonSight prosthetic replacement of the ocular surface ecosystem (PROSE) treatment in ocular surface disease. We undertook retrospective analysis of the medical records of a series of patients who underwent PROSE treatment from August 2006 to December 2014. Patients were referred for ocular surface disease of various etiologies. Primary inclusion criterion was corneal opacity that improved with PROSE treatment. Patients were excluded if topical steroids or adjuvant therapy used once PROSE treatment was initiated. Underlying disease, prior treatment, clinical presentation, and clinical course were extracted from the medical record. Four patients are included in this series. There were three females and one male; median age at time of treatment initiation was 30 years (range = 0.5-58 years). Median duration of PROSE treatment at time of retrospective analysis was 3.5 years (range = 1-8 years). Two cases had corneal opacification in the context of neurotrophic keratopathy: a unilateral case due to presumed herpes simplex keratitis and a bilateral case due to congenital corneal anesthesia associated with familial dysautonomia. One case had corneal opacity from exposure related to seventh nerve palsy, and one had corneal opacification associated with recurrent surface breakdown, neurotrophic keratopathy, and limbal stem deficiency of uncertain etiology. After consistent wear of prosthetic devices used in PROSE treatment for support of the ocular surface, visual acuity improved and clearing of the opacities was observed, without use of topical steroids or adjuvant therapy. These cases demonstrate clearing of chronic corneal opacity with PROSE treatment for ocular surface disease. This clearing can occur with no adjuvant therapy, suggesting that restoration of ocular surface function and integrity allows for corneal remodeling.

  7. 'Grounded' Politics

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2012-01-01

    play within one particular neighbourhood: Nørrebro in the Danish capital, Copenhagen. The article introduces the concept of grounded politics to analyse how groups of Muslim immigrants in Nørrebro use the space, relationships and history of the neighbourhood for identity political statements....... The article further describes how national political debates over the Muslim presence in Denmark affect identity political manifestations within Nørrebro. By using Duncan Bell’s concept of mythscape (Bell, 2003), the article shows how some political actors idealize Nørrebro’s past to contest the present...... ethnic and religious diversity of the neighbourhood and, further, to frame what they see as the deterioration of genuine Danish identity....

  8. Erbium concentration dependent absorbance in tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Sazali, E. S., E-mail: mdsupar@utm; Rohani, M. S., E-mail: mdsupar@utm; Sahar, M. R., E-mail: mdsupar@utm; Arifin, R., E-mail: mdsupar@utm; Ghoshal, S. K., E-mail: mdsupar@utm; Hamzah, K., E-mail: mdsupar@utm [Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor Bahru, Johor (Malaysia)

    2014-09-25

    Enhancing the optical absorption cross-section in topically important rare earth doped tellurite glasses is challenging for photonic devices. Controlled synthesis and detailed characterizations of the optical properties of these glasses are important for the optimization. The influence of varying concentration of Er{sup 3+} ions on the absorbance characteristics of lead tellurite glasses synthesized via melt-quenching technique are investigated. The UV-Vis absorption spectra exhibits six prominent peaks centered at 490, 526, 652, 800, 982 and 1520 nm ascribed to the transitions in erbium ion from the ground state to the excited states {sup 4}F{sub 7/2}, {sup 2}H{sub 11/2}, {sup 4}F{sub 9/2}, {sup 4}I{sub 9/2}, {sup 2}H{sub 11/2} and {sup 4}I{sub 13/2}, respectively. The results are analyzed by means of optical band gap E{sub g} and Urbach energy E{sub u}. The values of the energy band gap are found decreased from 2.82 to 2.51 eV and the Urbach energy increased from 0.15 to 0.24 eV with the increase of the Er{sub 2}O{sub 3} concentration from 0 to 1.5 mol%. The excellent absorbance of the prepared tellurite glasses makes them suitable for fabricating solid state lasers.

  9. Wastes based glasses and glass-ceramics

    Directory of Open Access Journals (Sweden)

    Barbieri, L.

    2001-12-01

    Full Text Available Actually, the inertization, recovery and valorisation of the wastes coming from municipal and industrial processes are the most important goals from the environmental and economical point of view. An alternative technology capable to overcome the problem of the dishomogeneity of the raw material chemical composition is the vitrification process that is able to increase the homogeneity and the constancy of the chemical composition of the system and to modulate the properties in order to address the reutilization of the waste. Moreover, the glasses obtained subjected to different controlled thermal treatments, can be transformed in semy-cristalline material (named glass-ceramics with improved properties with respect to the parent amorphous materials. In this review the tailoring, preparation and characterization of glasses and glass-ceramics obtained starting from municipal incinerator grate ash, coal and steel fly ashes and glass cullet are described.

    Realmente la inertización, recuperación y valorización de residuos que proceden de los procesos de incineración de residuos municipales y de residuos industriales son metas importantes desde el punto de vista ambiental y económico. Una tecnología alternativa capaz de superar el problema de la heterogeneidad de la composición química de los materiales de partida es el proceso de la vitrificación que es capaz de aumentar la homogeneidad y la constancia de la composición química del sistema y modular las propiedades a fin de la reutilización del residuo. En este artículo se presentan los resultados de vitrificación en que los vidrios fueron sometidos a tratamientos térmicos controlados diferentes, de manera que se transforman en materiales semicristalinos (también denominados vitrocerámicos con mejores propiedades respecto a los materiales amorfos originales. En esta revisión se muestra el diseño, preparación y caracterización de vidrios y vitrocerámicos partiendo de

  10. Performance Characteristics of Waste Glass Powder Substituting Portland Cement in Mortar Mixtures

    Science.gov (United States)

    Kara, P.; Csetényi, L. J.; Borosnyói, A.

    2016-04-01

    In the present work, soda-lime glass cullet (flint, amber, green) and special glass cullet (soda-alkaline earth-silicate glass coming from low pressure mercury-discharge lamp cullet and incandescent light bulb borosilicate glass waste cullet) were ground into fine powders in a laboratory planetary ball mill for 30 minutes. CEM I 42.5N Portland cement was applied in mortar mixtures, substituted with waste glass powder at levels of 20% and 30%. Characterisation and testing of waste glass powders included fineness by laser diffraction particle size analysis, specific surface area by nitrogen adsorption technique, particle density by pycnometry and chemical analysis by X-ray fluorescence spectrophotometry. Compressive strength, early age shrinkage cracking and drying shrinkage tests, heat of hydration of mortars, temperature of hydration, X-ray diffraction analysis and volume stability tests were performed to observe the influence of waste glass powder substitution for Portland cement on physical and engineering properties of mortar mixtures.

  11. Utilization of waste glass in ECO-cement: Strength properties and microstructural observations

    International Nuclear Information System (INIS)

    Sobolev, Konstantin; Tuerker, Pelin; Soboleva, Svetlana; Iscioglu, Gunsel

    2007-01-01

    Waste glass creates a serious environmental problem, mainly because of the inconsistency of the waste glass streams. The use of waste glass as a finely ground mineral additive (FGMA) in cement is a promising direction for recycling. Based on the method of mechano-chemical activation, a new group of ECO-cements was developed. In ECO-cement, relatively large amounts (up to 70%) of portland cement clinker can be replaced with waste glass. This report examines the effect of waste glass on the microstructure and strength of ECO-cement based materials. Scanning electron microscopy (SEM) investigations were used to observe the changes in the cement hydrates and interface between the cement matrix and waste glass particles. According to the research results, the developed ECO-cement with 50% of waste glass possessed compressive strength properties at a level similar to normal portland cement

  12. LSA glass-ceramic tiles made by powder pressing

    International Nuclear Information System (INIS)

    Figueira, F.C.; Bertan, F.M.; Riella, H.G.; Uggioni, E.; Bernardin, A.M.

    2009-01-01

    A low cost alternative for the production of glass-ceramic materials is the pressing of the matrix glass powders and its consolidation simultaneously with crystallization in a single stage of sintering. The main objective of this work was to obtain LSA glass ceramics with low thermal expansion, processed by pressing and sintering a ceramic frit powder. The raw materials were homogenized and melted (1480 deg C, 80min), and the melt was poured in water. The glass was chemically (XRF and AAS) and thermally (DTA, 10 deg C/min, air) characterized, and then ground (60min and 120min). The ground powders were characterized (laser diffraction) and compressed (35MPa and 45MPa), thus forming four systems. The compacts were dried (150 deg C, 24h) and sintered (1175 deg C and 1185 deg C, 10 deg C/min). Finally, the glass-ceramics were characterized by microstructural analysis (SEM and XRD), mechanical behavior (σbending) and thermal analysis (α). The best results for thermal expansion were those for the glass-ceramics processed with smaller particle size and greater compaction pressure. (author)

  13. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D; Bradley Pickenheim, B

    2008-11-24

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  14. Optimized Synthesis of Foam Glass from Recycled CRT Panel Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    Most of the panel glass from cathode ray tubes (CRTs) is landfilled today. Instead of landfilling, the panel glass can be turned into new environment-friendly foam glass. Low density foam glass is an effective heat insulating material and can be produced just by using recycle glass and foaming...... additives. In this work we recycle the CRT panel glass to synthesize the foam glass as a crucial component of building and insulating materials. The synthesis conditions such as foaming temperature, duration, glass particle size, type and concentrations of foaming agents, and so on are optimized...... by performing systematic experiments. In particular, the concentration of foaming agents is an important parameter that influences the size of bubbles and the distribution of bubbles throughout the sample. The foam glasses are characterised regarding density and open/closed porosity. Differential scanning...

  15. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    International Nuclear Information System (INIS)

    Adamson, D.; Pickenheim, Bradley

    2008-01-01

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  16. Green fluorescence of terbium ions in lithium fluoroborate glasses ...

    Indian Academy of Sciences (India)

    tion and solid-state lasers attracted remarkable attention in the last few decades. .... Figure 1. Vis absorption spectrum of 1.0 mol% Tb3+-doped. LBZLFB glass. Figure 2. .... both ions quickly decay non-radiatively to the ground level. The energy ...

  17. Parametric testing of a DWPF glass

    International Nuclear Information System (INIS)

    Bazan, F.; Rego, J.

    1985-03-01

    A series of tests has been performed to characterize the chemical stability of a DWPF borosilicate glass sample as part of the Waste Package Task of the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. This material was prepared at the Savannah River Laboratory for the purpose of testing the 165-frit matrix doped with a simulated nonradioactive waste. All tests were conducted at 90 0 C using deionized water and J-13 water (a tuffaceous formation ground water). In the deionized water tests, both monoliths and crushed glass were tested at various ratios of surface area of the sample to volume of water in order to compare leach rates for different sample geometries or leaching times. Effects on the leach rates as a result of the presence of crushed tuff and stainless steel material were also investigated in the tests with J-13 water. 3 refs., 12 figs., 7 tabs

  18. Measurement of nurses' attitudes and knowledge regarding acute care older patients: Psychometrics of the OPACS-US combined with the KOP-Q.

    Science.gov (United States)

    Dikken, Jeroen; Hoogerduijn, Jita G; Lagerwey, Mary D; Shortridge-Baggett, Lillie; Klaassen, Sharon; Schuurmans, Marieke J

    In clinical practice, identifying positive and negative attitudes toward older patients is very important to improve quality of care provided to them. The Older People in Acute Care Survey - United States (OPACS-US) is an instrument measuring hospital nurses attitudes regarding older patients. However, psychometrics have never been assessed. Furthermore, knowledge being related to attitude and behavior should also be measured complementing the OPACS-US. The purpose of this study was to assess structural validity and reliability of the OPACS-US and assess whether the OPACS-US can be complemented with the Knowledge about Older Patients-Quiz (KOP-Q). A multicenter cross sectional design was conducted. Registered nurses (n = 130, mean age 39,9 years; working experience 14,6 years) working in four general hospitals were included in the study. Nurses completed the OPACS-US section A: practice experiences, B: general opinion and the KOP-Q online. Findings demonstrated that the OPACS-US is a valid and reliable survey instrument that measures practice experiences and general opinion. Furthermore, the OPACS-US can be combined with the KOP-Q adding a knowledge construct, and is ready for use within education and/or quality improvement programs in the USA. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Nuclear waste glass corrosion mechanisms

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1987-04-01

    Dissolution of nuclear waste glass occurs by corrosion mechanisms similar to those of other solids, e.g., metallurgical and mineralogic systems. Metallurgical phenomena such as active corrosion, passivation and immunity have been observed to be a function of the glass composition and the solution pH. Hydration thermodynamics was used to quantify the role of glass composition and its effect on the solution pH during dissolution. A wide compositional range of natural, lunar, medieval, and nuclear waste glasses, as well as some glass-ceramics were investigated. The factors observed to affect dissolution in deionized water are pertinent to the dissolution of glass in natural environments such as the groundwaters anticipated to interact with nuclear waste glass in a geologic repository. The effects of imposed pH and oxidation potential (Eh) conditions existing in natural environments on glass dissolution is described in the context of Pourbaix diagrams, pH potential diagrams, for glass

  20. Characterization of Incorporation the Glass Waste in Adhesive Mortar

    Science.gov (United States)

    Santos, D. P.; Azevedo, A. R. G.; Hespanhol, R. L.; Alexandre, J.

    Ehe search for reuse generated waste in urban centers, intending to preserve natural resources, has remained fairly constant, both in context of preventing exploitation of resources as the emplacement of waste on the environment. Glass waste glass created a serious environmental problem, mainly because of inconsistency of its flows. Ehe use of this product as a mineral additive, finely ground, cement replacement and aggregate is a promising direction for recycling. This work aims to study the influence of glass waste from cutting process in adhesive mortar, replacing part of cement. Ehe glass powder is used replacing Portland cement at 10, 15 and 20% by mass. Ehe produced mortars will be evaluated its performance in fresh and hardened states through tests performed in laboratory. Ehe selected feature is indicated by producers of additive and researchers to present good results when used as adhesive mortar.

  1. Electrical properties of phosphate glasses

    International Nuclear Information System (INIS)

    Mogus-Milankovic, A; Santic, A; Reis, S T; Day, D E

    2009-01-01

    Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized glass (glass-ceramics) by IS are analyzed. A change in the characteristic features of IS follows the changes in glass and crystallized glass network. Using IS, the contribution of glass matrix, crystallized grains and grain boundary to the total electrical conductivity for iron phosphate glasses was analyzed. It was shown that decrease in conductivity is caused by discontinuities in the conduction pathways as a result of the disruption of crystalline network where two or more crystalline phases are formed. Also, phosphate-based glasses offer a unique range of biomaterials, as they form direct chemical bonding with hard/soft tissue. The surface charges of bioactive glasses are recognized to be the most important factors in determining biological responses. The improved bioactivity of the bioactive glasses as a result of the effects of the surface charges generated by electrical polarization is discussed.

  2. Theory of glass

    International Nuclear Information System (INIS)

    Rivier, N.

    1985-01-01

    The physical properties of glass are direct consequences of its non-crystalline structure. The structure is described from a topological point of view, since topology is the only geometry surviving non-crystallinity, i.e. absence of metric and trivial space group. This fact has two main consequences: the overall homogeneity of glass is a gauge symmetry, and the only extended, structurally stable constituents are odd lines (or 2π-disclinations in the elastic continuum limit). A gauge theory of glass, based on odd lines as sources of frozen-in strain, can explain those properties of glasses which are both specific to, and universal in amorphous solids: low-temperature excitations, and relaxation at high temperatures. The methods of statistical mechanics can be applied to give a minimal description of amorphous structures in statistical equilibrium. Criteria for statistical equilibrium of the structure and detailed balance are given, together with structural equations of state, which turn out to be well-known empirically among botanists and metallurgists. This review is based on lectures given in 1984 in Niteroi. It contains five parts: I - Structure, from a topological viewpoint; II - gauge invariance; III - Tunneling modes; IV - Supercooled liquid and the glass transitions; V - Statistical crystallography. (Author) [pt

  3. Sol-Gel Glasses

    Science.gov (United States)

    Mukherjee, S. P.

    1985-01-01

    Multicomponent homogeneous, ultrapure noncrystalline gels/gel derived glasses are promising batch materials for the containerless glass melting experiments in microgravity. Hence, ultrapure, homogeneous gel precursors could be used to: (1) investigate the effect of the container induced nucleation on the glass forming ability of marginally glass forming compositions; and (2) investigate the influence of gravity on the phase separation and coarsening behavior of gel derived glasses in the liquid-liquid immiscibility zone of the nonsilicate systems having a high density phase. The structure and crystallization behavior of gels in the SiO2-GeO2 as a function of gel chemistry and thermal treatment were investigated. As are the chemical principles involved in the distribution of a second network former in silica gel matrix being investigated. The procedures for synthesizing noncrystalline gels/gel-monoliths in the SiO2-GeO2, GeO2-PbO systems were developed. Preliminary investigations on the levitation and thermal treatment of germania silicate gel-monoliths in the Pressure Facility Acoustic Levitator were done.

  4. Defining the Glass Composition Limits for SRS Contaminated Soils

    International Nuclear Information System (INIS)

    Cicero, C.A.; Bickford, D.F.; Crews, W.O.

    1995-01-01

    Contaminated soil resulting from the excavation, repair, and decommissioning of facilities located at the Savannah River Site (SRS) is currently being disposed of by shallow land burial or is being stored when considered only hazardous. Vitrification of this waste is being investigated, since it will bind the hazardous and radioactive species in a stable and durable glass matrix, which will reduce the risk of ground water contamination. However, the composition limits for producing durable glass have to be determined before the technology can be applied. Glass compositions, consisting of SRS soil and glass forming additives, were tested on a crucible-scale in three ternary phase systems. Nine different glass compositions were produced, with waste loadings ranging from 43 to 58 weight percent. These were characterized using varoius chemical methods and tested for durability in both alkaline and acidic environments. All nine performed well in alkaline environments, but only three met the strictest criteria for the acidic environment tests. Although the glasses did not meet all of the limits for the acidic tests, the test was performed on very conservative size samples, so the results were also conservative. Therefore, enough evidence was found to provide proof that SRS soil can be vitrified in a durable glass matrix

  5. Ion exchange for glass strengthening

    International Nuclear Information System (INIS)

    Gy, Rene

    2008-01-01

    This paper presents a short overview of silicate glass strengthening by exchange of alkali ions in a molten salt, below the glass transition temperature (chemical tempering). The physics of alkali inter-diffusion is briefly explained and the main parameters of the process, which control the glass reinforcement, are reviewed. Methods for characterizing the obtained residual stress state and the strengthening are described, along with the simplified modelling of the stress build-up. The fragmentation of chemically tempered glass is discussed. The concept of engineered stress profile glass is presented, and finally, the effect of glass and salt compositions is overviewed

  6. Chemical durability of lead borosilicate glass matrix under simulated geological conditions

    International Nuclear Information System (INIS)

    Yalmali, Vrunda S.; Deshingkar, D.S.; Wattal, P.K.

    2002-03-01

    The lead borosilicate glass has been developed for vitrification of High Level Waste (HLW) stored at Trombay. This waste is contains especially high contents of sodium, uranium sulphate and iron. The glasses containing HLW are to be ultimately disposed into deep geological repositories. Long term leach rates under simulated geological conditions need to be evaluated for glass matrix. Studies were taken up to estimate the lead borosilicate glass WTR-62 matrix for chemical durability in presence of synthetic ground water. The leachant selected was based on composition of ground water sample near proposed repository site. In the first phase of these tests, the experiments were conducted for short duration of one and half month. The leaching experiments were conducted in presence of a) distilled water b) synthetic ground water c) synthetic ground water containing granite, bentonite and ferric oxide and d) synthetic ground water containing humic acid at 100 0 C. The leachate samples were analysed by pHmetry , ion chromatography and UV -VIS spectrophotometry. The normalised leach rates for lead borosilicate WTR- 62 glass matrix based on silica, boron and sulphate analyses of leachates were of the order of 10 -3 to 10 -5 gms/cm 2 /day for 45 days test period in presence of synthetic ground water as well as in presence of other materials likely to be present along with synthetic ground water. These rates are comparable to those of sodium borsilicate glass matrices reported in literature. It is known that the leach rates of glass matrix decrease with longer test durations due to formation of leached layer on its surface. The observed leach rates of lead borosilicate WTR- 62 glass matrix for 45 day tests under simulated geological conditions were found to be sufficiently encouraging to take up long term tests for evaluating its performances under repository conditions. (author)

  7. Perspectives on spin glasses

    CERN Document Server

    Contucci, Pierluigi

    2013-01-01

    Presenting and developing the theory of spin glasses as a prototype for complex systems, this book is a rigorous and up-to-date introduction to their properties. The book combines a mathematical description with a physical insight of spin glass models. Topics covered include the physical origins of those models and their treatment with replica theory; mathematical properties like correlation inequalities and their use in the thermodynamic limit theory; main exact solutions of the mean field models and their probabilistic structures; and the theory of the structural properties of the spin glass phase such as stochastic stability and the overlap identities. Finally, a detailed account is given of the recent numerical simulation results and properties, including overlap equivalence, ultrametricity and decay of correlations. The book is ideal for mathematical physicists and probabilists working in disordered systems.

  8. Waste glass melting stages

    International Nuclear Information System (INIS)

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1994-01-01

    Three simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C to 1000 degrees C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentru Karlsruhe (KfK) in Germany were used. The samples were thin sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. The behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied. 2 refs., 8 tabs

  9. Waste glass melting stages

    International Nuclear Information System (INIS)

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1993-04-01

    Three different simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C--1000 degrees C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentrum Karlsruhe (KfK) in Germany were used. The samples were thin-sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. Behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied

  10. Using physical properties of molten glass to estimate glass composition

    International Nuclear Information System (INIS)

    Choi, Kwan Sik; Yang, Kyoung Hwa; Park, Jong Kil

    1997-01-01

    A vitrification process is under development in KEPRI for the treatment of low-and medium-level radioactive waste. Although the project is for developing and building Vitrification Pilot Plant in Korea, one of KEPRI's concerns is the quality control of the vitrified glass. This paper discusses a methodology for the estimation of glass composition by on-line measurement of molten glass properties, which could be applied to the plant for real-time quality control of the glass product. By remotely measuring viscosity and density of the molten glass, the glass characteristics such as composition can be estimated and eventually controlled. For this purpose, using the database of glass composition vs. physical properties in isothermal three-component system of SiO 2 -Na 2 O-B 2 O 3 , a software TERNARY has been developed which determines the glass composition by using two known physical properties (e.g. density and viscosity)

  11. Superductile bulk metallic glass

    International Nuclear Information System (INIS)

    Yao, K.F.; Ruan, F.; Yang, Y.Q.; Chen, N.

    2006-01-01

    Usually, monolithic bulk metallic glasses undergo inhomogeneous plastic deformation and exhibit poor ductility (<2%) at room temperature. We report a newly developed Pd-Si binary bulk metallic glass, which exhibits a uniform plastic deformation and a large plastic engineering strain of 82% and a plastic true strain of 170%, together with initial strain hardening, slight strain softening and final strain hardening characteristics. The uniform shear deformation and the ultrahigh plasticity are mainly attributed to strain hardening, which results from the nanoscale inhomogeneity due to liquid phase separation. The formed nanoscale inhomogeneity will hinder, deflect, and bifurcate the propagation of shear bands

  12. A consistent multigroup model for radiative transfer and its underlying mean opacities

    International Nuclear Information System (INIS)

    Turpault, Rodolphe

    2005-01-01

    In some regimes, such as in plasma physics or in super orbital atmospheric entry of space objects, the effects of radiation are crucial and can tremendously modify the hydrodynamics of the gas. In such cases, it is therefore important to have a good prediction of the radiative variables. However, full transport solutions of these multi-dimensional, time-dependent problems are too expensive to get to be involved in a coupled configuration. It is hence necessary to develop other models for radiation that are cheap, yet accurate enough to give good predictions of the radiative effects. We will herein introduce the multigroup-M1 model and look at its characteristics and in particular try to separate the angular error from the frequential one since these two approximation play very different roles. The angular behaviour of the model will be tested on a case proposed by Su and Olson and used by Olson et al. to compare various moments and (flux-limited) diffusion models. For the frequency behaviour, we use a simplified flame test-case and show the importance of taking good mean opacities

  13. Rare cause of multiple nodular opacities at chest x-ray: pulmonary hydatid cyst

    International Nuclear Information System (INIS)

    Inan, K.; Hamcan, S.; Gumus, S.; Turhan, U.; Karaman, B.

    2012-01-01

    Full text: Introduction: Hydatid disease is incidentally common in our country. Objectives and tasks: In this study, unlike the classical radiological appearance of hydatid disease of the lung, MDCT appearance of multiple nodules were demonstrated. Materials and methods: The patient who comes our hospital's Pulmonary Clinic with shortness of breath and with membranes that come from his mouth, referred to our clinic for chest radiography and chest HRCT. Results: In the conventional chest x-ray, multiple nodular opacities in both lungs were common. HRCT was performed with 5 mm and 1 mm thick sections of our patient. In both hemithorax, multiple nodular lesions were found in various sizes and configurations, some of them opened to the bronchus which is the largest one is 2 cm in diameter. Nodule in the left hemithorax inferior lingular segment has calcified wall. Patient's Echinococcus granulosus test was evaluated positive for IgG. Conclusion: Hydatid disease is a parasitic infestation created by Echinococcus granulosus. Although seen most frequently in the liver, often seen in the lungs 10-30%.. 30 to 50% of cases are asymptomatic and incidentally diagnosed radiologically. Although we know that the classic radiologic findings of hydatid cyst, different radiographic views (eg nodular mass) should be considered in rare circumstances

  14. Thermonuclear Bursts with Short Recurrence Times from Neutron Stars Explained by Opacity-driven Convection

    Energy Technology Data Exchange (ETDEWEB)

    Keek, L. [X-ray Astrophysics Laboratory, Astrophysics Science Division, NASA/GSFC, Greenbelt, MD 20771 (United States); Heger, A., E-mail: laurens.keek@nasa.gov [Monash Center for Astrophysics, School of Physics and Astronomy, Monash University, Victoria, 3800 (Australia)

    2017-06-20

    Thermonuclear flashes of hydrogen and helium accreted onto neutron stars produce the frequently observed Type I X-ray bursts. It is the current paradigm that almost all material burns in a burst, after which it takes hours to accumulate fresh fuel for the next burst. In rare cases, however, bursts are observed with recurrence times as short as minutes. We present the first one-dimensional multi-zone simulations that reproduce this phenomenon. Bursts that ignite in a relatively hot neutron star envelope leave a substantial fraction of the fuel unburned at shallow depths. In the wake of the burst, convective mixing events driven by opacity bring this fuel down to the ignition depth on the observed timescale of minutes. There, unburned hydrogen mixes with the metal-rich ashes, igniting to produce a subsequent burst. We find burst pairs and triplets, similar to the observed instances. Our simulations reproduce the observed fraction of bursts with short waiting times of ∼30%, and demonstrate that short recurrence time bursts are typically less bright and of shorter duration.

  15. FERMI LARGE AREA TELESCOPE CONSTRAINTS ON THE GAMMA-RAY OPACITY OF THE UNIVERSE

    International Nuclear Information System (INIS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Atwood, W. B.; Baldini, L.; Bellazzini, R.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Baughman, B. M.; Bhat, P. N.; Bonamente, E.

    2010-01-01

    The extragalactic background light (EBL) includes photons with wavelengths from ultraviolet to infrared, which are effective at attenuating gamma rays with energy above ∼10 GeV during propagation from sources at cosmological distances. This results in a redshift- and energy-dependent attenuation of the γ-ray flux of extragalactic sources such as blazars and gamma-ray bursts (GRBs). The Large Area Telescope on board Fermi detects a sample of γ-ray blazars with redshift up to z ∼ 3, and GRBs with redshift up to z ∼ 4.3. Using photons above 10 GeV collected by Fermi over more than one year of observations for these sources, we investigate the effect of γ-ray flux attenuation by the EBL. We place upper limits on the γ-ray opacity of the universe at various energies and redshifts and compare this with predictions from well-known EBL models. We find that an EBL intensity in the optical-ultraviolet wavelengths as great as predicted by the 'baseline' model of Stecker et al. can be ruled out with high confidence.

  16. Opacity and gradients in aluminum wire array z-pinch implosions on the Z pulsed power facility

    Energy Technology Data Exchange (ETDEWEB)

    Ampleford, D. J., E-mail: damplef@sandia.gov; Hansen, S. B.; Jennings, C. A.; Jones, B.; Coverdale, C. A.; Harvey-Thompson, A. J.; Rochau, G. A.; Dunham, G.; Moore, N. W.; Harding, E. C.; Cuneo, M. E. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Chong, Y.-K.; Clark, R. W.; Ouart, N.; Thornhill, J. W.; Giuliani, J.; Apruzese, J. P. [Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-03-15

    Aluminum wire array z pinches imploded on the Z generator are an extremely bright source of 1–2 keV radiation, with close to 400 kJ radiated at photon energies >1 keV and more than 50 kJ radiated in a single line (Al Ly-α). Opacity plays a critical role in the dynamics and K-shell radiation efficiency of these pinches. Where significant structure is present in the stagnated pinch this acts to reduce the effective opacity of the system as demonstrated by direct analysis of spectra. Analysis of time-integrated broadband spectra (0.8–25 keV) indicates electron temperatures ranging from a few 100 eV to a few keV are present, indicative of substantial temperature gradients.

  17. APLIKASI ONLINE PUBLIC ACCESS CATALOQUE (OPAC BERBASIS ANDROID SEBAGAI SARANA TEMU KEMBALI INFORMASI DI PERPUSTAKAAN UNIVERSITAS PENDIDIKAN GANESHA

    Directory of Open Access Journals (Sweden)

    Putu Tika Parmawati

    2016-08-01

    Full Text Available Abstrak Penelitian ini bertujuan untuk mengembangkan perangkat lunak aplikasi Online Public Access Cataloque (OPAC berbasis android. Jenis penelitian ini merupakan Research and Development (R & D dengan metode pengembangan menggunakan model prototyping. Pengembangan sistem informasi layanan audio visual berbasis video streaming dengan enam tahap, yaitu : 1 Tahap pengumpulan kebutuhan dan perbaikan, 2 Tahap perancangan desain cepat (desain awal, 3 Tahap membangun prototipe, 4 Tahap evaluasi prototype, 5 Tahap perbaikan prototype, dan 6 Tahap rekayasa produk. Penentuan tingkat kelayakan aplikasi Online Public Access Cataloque (OPAC berbasis android berdasarkan uji validasi ahli bidang teknologi informasi dan uji coba terbatas pada pengguna. Hasil uji coba sebagai berikut : 1 Pengembangan aplikasi Online Public Access Cataloque (OPAC berbasis android sudah sesuai dengan spesifikasi yang telah ditentukan sebagai aplikasi penelusuran informasi koleksi buku teks umum secara online melalui smartphone. 2 Indikator penilaian dari program ini adalah kebenaran atau ketepatan operasional sistem, ketegaran, keterluasan, keterpakaian ulang, efisiensi atau kinerja, portabilitas, integritas, modularitas, keterbacaan mendapat kualifikasi cukup baik, sedangkan verifikasi mendapat kualifikasi baik. 3 Secara umum dari hasil penilaian tersebut aplikasi OPAC berbasis android ini cukup layak untuk digunakan sebagai alternatif pelengkap pemberian layanan penelusuran informasi koleksi buku teks umum di Perpustakaan Undiksha. Kata Kunci: OPAC, android, dan temu kembali informasi Abstract Aim of this study to develop the software of Online Public Access Cataloque (OPAC based on android. Research and Development (R & D design was applied in this study which was developed through prototyping models. The software was constructed through six stages, namely: 1 needs analysis and repairment, 2 rapid design (preliminary design, 3 prototypes building, 4 prototype evaluation, 5

  18. Crescentic and ring-shaped opacities. CT features in two cases of bronchiolitis obliterans organizing pneumonia (BOOP)

    International Nuclear Information System (INIS)

    Voloudaki, A.E.; Bouros, D.E.; Froudarakis, M.E.; Datseris, G.E.; Apostolaki, E.G.; Gourtsoyiannis, N.C.

    1996-01-01

    Two cases of idiopathic bronchilitis obliterans organizing pneumonia (BOOP) with unusual CT findings are presented. On CT both cases exhibited crescentic and ring-shaped opacities, surrounding areas of groundglass attenuation, and associated with a nodular pattern in one patient and airspace consolidations in the second patient. CT-pathologic correlation dislosed that the central areas of groundglass attenuation corresponded to alveolar septal inflammation, in contrast to the denser periphery where granulomatous tissue in peripheral airspaces predominated. In the broad spectrum of CT findings, BOOP can exhibit specific CT features with regard to the crescentic or ring-shaped opacities with a central groundglass attenuation area. Since these features have not been described in any other disease, they might be characteristic features for the diagnosis of BOOP. (orig.)

  19. Significance of lenticular opacity from the view point of the exposure dose of A-bomb radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, S [Sugimoto Hospital, Hiroshima (Japan)

    1975-04-01

    Two cases of lenticular opacity were discussed from the view point of exposure dose of A-bomb radiation. Case 1: female, 22 year and 5 months old when she was exposured to A-bomb radiation. The presumed exposure dose was 482.0 rad. Cataract due to A-bomb radiation. Case 2: female, 21 years and 6 months old when she was exposured to A-bomb radiation. The presumed exposure dose was more than 1,000 rad. Cataract due to A-bomb radiation and incipient cataract senilis. It was reported here that there was a marked difference in opacity findings of cataract due to A-bomb radiation in accordance with difference in exposure dose of radiation. It was also presumed from the findings of incipient cataract senilis that with increasing exposure dose, the aging phenomenon was promoted.

  20. Aging in a Structural Glass

    OpenAIRE

    Kob, Walter; Barrat, Jean-Louis

    1998-01-01

    We discuss the relaxation dynamics of a simple structural glass which has been quenched below its glass transition temperature. We demonstrate that time correlation functions show strong aging effects and investigate in what way the fluctuation dissipation theorem is violated.

  1. Foam Glass for Construction Materials

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund

    2016-01-01

    Foaming is commonly achieved by adding foaming agents such as metal oxides or metal carbonates to glass powder. At elevated temperature, the glass melt becomes viscous and the foaming agents decompose or react to form gas, causing a foamy glass melt. Subsequent cooling to room temperature, result...... in a solid foam glass. The foam glass industry employs a range of different melt precursors and foaming agents. Recycle glass is key melt precursors. Many parameters influence the foaming process and optimising the foaming conditions is very time consuming. The most challenging and attractive goal is to make...... low density foam glass for thermal insulation applications. In this thesis, it is argued that the use of metal carbonates as foaming agents is not suitable for low density foam glass. A reaction mechanism is proposed to justify this result. Furthermore, an in situ method is developed to optimise...

  2. Excimer laser-assisted anterior lamellar keratoplasty for keratoconus, corneal problems after laser in situ keratomileusis, and corneal stromal opacities.

    Science.gov (United States)

    Bilgihan, Kamil; Ozdek, Sengül C; Sari, Ayça; Hasanreisoğlu, Berati

    2006-08-01

    To evaluate excimer laser-assisted anterior lamellar keratoplasty to augment thin corneas as in keratoconus ( .05). This technique presents a different modality for the treatment of keratoconus, post-LASIK corneal problems, and other corneal stromal opacities with anterior lamellar keratoplasty. Additional studies with more patients and longer follow-up will help determine the role of this technique as a substitute for penetrating keratoplasty in these patients.

  3. Influence of Projection Operator on Oxygen Line Shapes and its effect on Rosseland-Mean Opacity in Stellar Interiors

    Science.gov (United States)

    Gomez, Thomas; Nagayama, Taisukue; Kilcrease, David; Hansen, Stephanie; Montgomery, Mike; Winget, Don

    2018-01-01

    The Rosseland-Mean opacity (RMO) is an important quantity in determining radiation transport through stars. The solar-convection-zone boundary predicted by the standard solar model disagrees with helioseismology measurements by many sigma; a 14% increase in the RMO would resolve this discrepancy. Experiments at Sandia National Laboratories are now measuring iron opacity at solar-interior conditions, and significant discrepancies are already observed. Highly-ionized oxygen is one of the dominant contributions to the RMO. The strongest line, Lyman alpha, is at the peak of the Rosseland weighting function. The accuracy of line-broadening calculations has been called into question due to various experimental results and comparisons between theory. We have developed an ab-initio calculation to explore different physical effects, our current focus is treating penetrating collisions explicitly. The equation of motion used to calculate line shapes within the relaxation and unified theories includes a projection operator, which performs an average over plasma electron states; this is neglected due to past calculations approximate treatment of penetrations. We now include this projection term explicitly, which results in a significant broadening of spectral lines from highly-charged ions (low-Z elements are not much affected). The additional broadening raises the O Ly-alpha wing opacity by a factor of 5; we examine the consequences of this additional broadening on the Rosseland mean.

  4. Glass ceilings of professionalisation.

    Science.gov (United States)

    Stott, Dawn L

    2016-04-01

    The term glass ceiling is a political term often used to describe an unbreakable barrier that isnot visible with the human eye, but it keeps minorities from rising up i.e. it is a barrier to minoritygroups, in the past (and sometimes still) for women, that stops them from achieving theirtrue potential.

  5. What Glass Ceiling?

    Science.gov (United States)

    Lynch, Michael; Post, Katherine

    1996-01-01

    A recent study drawing on data from the Census Bureau and the Bureau of Labor Statistics suggests that the wage gap between men and women has virtually disappeared, and that the so-called "glass ceiling" results more from age and qualifications than from explicit discrimination. (SLD)

  6. Metallic glasses: structural models

    International Nuclear Information System (INIS)

    Nassif, E.

    1984-01-01

    The aim of this work is to give a summary of the attempts made up to the present in order to discribe by structural models the atomic arrangement in metallic glasses, showing also why the structure factors and atomic distribution functions cannot be always experimentally determined with a reasonable accuracy. (M.W.O.) [pt

  7. Microchips on glass

    NARCIS (Netherlands)

    Nanver, L.; De Vreede, L.; Keulemans, M.

    2007-01-01

    Microchips on glass. What about a mobile phone that uses a single microchip to receive all the available frequency bands, plus extras such as television, gps, and Internet access? Or, in due time, see-though implants that will monitor your state of health, and equipment that will let you see through

  8. Glass as matter

    DEFF Research Database (Denmark)

    Beim, Anne

    2000-01-01

    Refraiming the Moderns - Substitute Windows and Glass. In general terms, the seminar has contributed to the growing interest in the problems concerning the restoration of Modern Movement architecture. More particularly, it has of course drawn our attention to modern windows, which are increasingly...

  9. Glass ... current issues

    International Nuclear Information System (INIS)

    Wright, A.F.; Dupuy, J.

    1985-01-01

    The objectives of the School were twofold. Firstly to inform participants of actual and developing technological applications of glassy materials in which fundamental science makes a strong contribution, and secondly to bring together scientists from the widely different backgrounds of glass science and technology to promote mutual understanding and collaboration. (orig.)

  10. Stained Glass and Flu

    Centers for Disease Control (CDC) Podcasts

    2017-02-01

    Dr. Robert Webster, an Emeritus member of the Department of Infectious Diseases at St. Jude Children's Research Hospital, discusses his cover art story on stained glass and influenza.  Created: 2/1/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/1/2017.

  11. Leach behavior of high-level borosilicate glasses under deep geological environment

    International Nuclear Information System (INIS)

    Kim, Seung Soo; Chun, Kwan Sik; Park, Hyun Soo

    1998-02-01

    This report presents an overview of the activities in high-level radioactive waste glass which is considered as the most practicable form of waste, and also is intended to be used in the disposal of national high-level radioactive waste in future. Leach theory of waste glass and the leach effects of ground water, metal barrier, buffer materials and rocks on the waste glass were reviewed. The leach of waste glass was affected by various factors such as composition, pH and Eh of ground water, temperature, pressure, radiation and humic acid. The crystallization, crack, weathering and the formation of altered phases of waste glass which is expected to occur in real disposal site were reviewed. The results of leaching in laboratory and in-situ were compared. The behaviors of radioactive elements leached from waste glass and the use of basalt glass for the long-term natural analogue of waste glass were also written in this report. The appraisal of durability of borosilicate waste glass as a waste media was performed from the known results of leach test and international in-situ tests were introduced. (author). 134 refs., 15 tabs., 24 figs

  12. Thermal and optical properties of Tm3+ doped tellurite glasses.

    Science.gov (United States)

    Ozen, G; Demirata, B; Oveçoğlu, M L; Genç, A

    2001-02-01

    Ultraviolet, visible (UV/VIS) and differential thermal analysis (DTA) measurements were carried out in order to investigate the optical and thermal properties of various 0.5 mol.% Tm2O3 containing (1 - x)TeO2 + xLiCl glasses in molar ratio. The samples were prepared by fusing the mixture of their respective reagent grade powders in a platinum cricuble at 750 degrees C for 30 min. DTA curves taken in the 23-600 degrees C temperature range with a heating rate of 10 degrees C/min reveal a change in the value of the glass transition temperature, Tg, while melting was not observed for the glasses containing LiCl content less than 50 mol.%. These glasses were found to be moisture-resistant. However, the glasses with LiCl content higher than 50 mol.%, in which a melting peak was observed at Tc = 401 degrees C, were moisture-sensitive. Absorption measurements in the UV/VIS region of the glasses without Tm2O3 content show that the Urbach cutoff occurs at about 320 nm and, is relatively independent of the LiCl content. Six absorption bands were observed in the Tm2O3 doped glasses corresponding to the absorption of the 1G4, 3F2, 3F3 and 3F4, 3H5 and 3H4 levels from the 3H6 ground level of Tm3+ ions. The spectra also show that the integrated absorption cross-section of each band depends on the glass composition. Judd-Ofelt theory was used to determine the Judd-Ofelt parameters as well as the radiative transition probabilities for the metastable levels of Tm3+ ions in (0.3)LiCl + (0.7) TeO2: 0.01 Tm2O3 glass which is moisture-resistant.

  13. Influence of the number of atomic levels on the spectral opacity of low temperature nickel and iron in the spectral range 50-300 eV

    International Nuclear Information System (INIS)

    Busquet, M.; Klapisch, M.; Gilles, D.

    2013-01-01

    Opacity is a fundamental ingredient for the secular evolution of stars. The calculation of the stellar plasma absorption coefficients is complex due to the composition of these plasmas, generally an H /He dominated mixture with a low concentration of partially ionized heavy ions (the iron group). The international collaboration OPAC recently presented extensive comparisons of spectral opacities of iron and nickel for temperatures between 15 and 40 eV and for densities of ∼ 3 mg/cm 3 , relevant to the stellar envelope conditions [1, 2]. The role of Configuration Interaction (CI) and the influence of the number of atomic levels on the opacity using the recently improved version of HULLAC atomic code [3, 4] are illustrated in this article. Comparisons with theoretical predictions already presented in [1] are discussed. (authors)

  14. Glasses and nuclear waste vitrification

    International Nuclear Information System (INIS)

    Ojovan, Michael I.

    2012-01-01

    Glass is an amorphous solid material which behaves like an isotropic crystal. Atomic structure of glass lacks long-range order but possesses short and most probably medium range order. Compared to crystalline materials of the same composition glasses are metastable materials however crystallisation processes are kinetically impeded within times which typically exceed the age of universe. The physical and chemical durability of glasses combined with their high tolerance to compositional changes makes glasses irreplaceable when hazardous waste needs immobilisation for safe long-term storage, transportation and consequent disposal. Immobilisation of radioactive waste in glassy materials using vitrification has been used successfully for several decades. Nuclear waste vitrification is attractive because of its flexibility, the large number of elements which can be incorporated in the glass, its high corrosion durability and the reduced volume of the resulting wasteform. Vitrification involves melting of waste materials with glass-forming additives so that the final vitreous product incorporates the waste contaminants in its macro- and micro-structure. Hazardous waste constituents are immobilised either by direct incorporation into the glass structure or by encapsulation when the final glassy material can be in form of a glass composite material. Both borosilicate and phosphate glasses are currently used to immobilise nuclear wastes. In addition to relatively homogeneous glasses novel glass composite materials are used to immobilise problematic waste streams. (author)

  15. The Column Density Distribution and Continuum Opacity of the Intergalactic and Circumgalactic Medium at Redshift langzrang = 2.4

    Science.gov (United States)

    Rudie, Gwen C.; Steidel, Charles C.; Shapley, Alice E.; Pettini, Max

    2013-06-01

    We present new high-precision measurements of the opacity of the intergalactic and circumgalactic medium (IGM; CGM) at langzrang = 2.4. Using Voigt profile fits to the full Lyα and Lyβ forests in 15 high-resolution high-S/N spectra of hyperluminous QSOs, we make the first statistically robust measurement of the frequency of absorbers with H I column densities 14 \\lesssim log (N_H\\,\\scriptsize{ I}/ {cm}^{-2}) \\lesssim 17.2. We also present the first measurements of the frequency distribution of H I absorbers in the volume surrounding high-z galaxies (the CGM, 300 pkpc), finding that the incidence of absorbers in the CGM is much higher than in the IGM. In agreement with Rudie et al., we find that there are fractionally more high-N H I absorbers than low-N H I absorbers in the CGM compared to the IGM, leading to a shallower power law fit to the CGM frequency distribution. We use these new measurements to calculate the total opacity of the IGM and CGM to hydrogen-ionizing photons, finding significantly higher opacity than most previous studies, especially from absorbers with log (N_H\\,\\scriptsize{ I}/ {cm}^{-2}) law parameterization of the frequency distribution with a break near N H I ≈1015 cm-2. We compute new estimates of the mean free path (λmfp) to hydrogen-ionizing photons at z em = 2.4, finding λmfp = 147 ± 15 Mpc when considering only IGM opacity. If instead, we consider photons emanating from a high-z star-forming galaxy and account for the local excess opacity due to the surrounding CGM of the galaxy itself, the mean free path is reduced to λmfp = 121 ± 15 Mpc. These λmfp measurements are smaller than recent estimates and should inform future studies of the metagalactic UV background and of ionizing sources at z ≈ 2-3. Based on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space

  16. Apollo 12 ropy glasses revisited

    Science.gov (United States)

    Wentworth, S. J.; Mckay, D. S.; Lindstrom, D. J.; Basu, A.; Martinez, R. R.; Bogard, D. D.; Garrison, D. H.

    1994-01-01

    We analyzed ropy glasses from Apollo 12 soils 12032 and 12033 by a variety of techniques including SEM/EDX, electron microprobe analysis, INAA, and Ar-39-Ar-40 age dating. The ropy glasses have potassium rare earth elements phosphorous (KREEP)-like compositions different from those of local Apollo 12 mare soils; it is likely that the ropy glasses are of exotic origin. Mixing calculations indicate that the ropy glasses formed from a liquid enriched in KREEP and that the ropy glass liquid also contained a significant amount of mare material. The presence of solar Ar and a trace of regolith-derived glass within the ropy glasses are evidence that the ropy glasses contain a small regolith component. Anorthosite and crystalline breccia (KREEP) clasts occur in some ropy glasses. We also found within these glasses clasts of felsite (fine-grained granitic fragments) very similar in texture and composition to the larger Apollo 12 felsites, which have a Ar-39-Ar-40 degassing age of 800 +/- 15 Ma. Measurements of 39-Ar-40-Ar in 12032 ropy glass indicate that it was degassed at the same time as the large felsite although the ropy glass was not completely degassed. The ropy glasses and felsites, therefore, probably came from the same source. Most early investigators suggested that the Apollo 12 ropy glasses were part of the ejecta deposited at the Apollo 12 site from the Copernicus impact. Our new data reinforce this model. If these ropy glasses are from Copernicus, they provide new clues to the nature of the target material at the Copernicus site, a part of the Moon that has not been sampled directly.

  17. Glass bead cultivation of fungi

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, H.

    2013-01-01

    Production of bioactive compounds and enzymes from filamentous fungi is highly dependent on cultivation conditions. Here we present an easy way to cultivate filamentous fungi on glass beads that allow complete control of nutrient supply. Secondary metabolite production in Fusarium graminearum...... and Fusarium solani cultivated on agar plates, in shaking liquid culture or on glass beads was compared. Agar plate culture and glass bead cultivation yielded comparable results while liquid culture had lower production of secondary metabolites. RNA extraction from glass beads and liquid cultures was easier...... to specific nutrient factors. •Fungal growth on glass beads eases and improves fungal RNA extraction....

  18. Sodium diffusion in boroaluminosilicate glasses

    DEFF Research Database (Denmark)

    Smedskjaer, Morten M.; Zheng, Qiuju; Mauro, John C.

    2011-01-01

    of isothermal sodium diffusion in BAS glasses by ion exchange, inward diffusion, and tracer diffusion experiments. By varying the [SiO2]/[Al2O3] ratio of the glasses, different structural regimes of sodium behavior are accessed. We show that the mobility of the sodium ions decreases with increasing [SiO2]/[Al2O......Understanding the fundamentals of alkali diffusion in boroaluminosilicate (BAS) glasses is of critical importance for advanced glass applications, e.g., the production of chemically strengthened glass covers for personal electronic devices. Here, we investigate the composition dependence...

  19. The role of opacity and transparency in achieving strategic stability in South Asia.

    Energy Technology Data Exchange (ETDEWEB)

    Rajain, Arpit (New Delhi, India); Ashraf, Tariq Mahmud (Islamabad, Pakistan)

    2005-08-01

    According to international relations theory, deterrence can be used as a tool to achieve stability between potentially hostile nations. India and Pakistan's long history of periodic crises raises the question of how they can achieve deterrence stability. 'Transparency' describes the flow of information between parties and plays a key role in establishing a deterrence relationship. This paper studies the balance needed between opacity and transparency in nuclear topics for the maintenance of deterrence stability between India and Pakistan. States with nuclear weapons are postulated to implement transparency in four categories: potential, capability, intent, and resolve. The study applies these categories to the nuclear components of the ongoing India-Pakistan Composite Dialogue Working Group for Peace and Security including CBMs. To focus our efforts, we defined four scenarios to characterize representative strategic/military/political conditions. The scenarios are combinations of these two sets of opposite poles: competition - cooperation; extremism - moderation (to be understood primarily in a religious/nationalistic sense). We describe each scenario in terms of select focal areas (nuclear doctrine, nuclear command and control, nuclear stockpile, nuclear delivery/defensive systems, and conventional force posture). The scenarios help frame the realm of possibilities, and have been described in terms of expected conditions for the focal areas. We then use the conditions in each scenario to prescribe a range of information-sharing actions that the two countries could take to increase stability. We also highlight the information that should not be shared. These actions can be political (e.g., declarations), procedural (e.g., advance notice of certain military activities), or technologically based (e.g., seismic monitoring of the nuclear test moratorium).

  20. Effect of irradiation times on the polymerization depth of contemporary fissure sealants with different opacities

    Directory of Open Access Journals (Sweden)

    Boniek Castillo Dutra Borges

    2011-04-01

    Full Text Available The aim of this study was to evaluate the depth of curing of 10 contemporary blue light-activated dental flowable materials at several opacities, influenced by different irradiation times using FT-IR spectroscopy. Fifty-five specimens (n = 5 with a 5-mm diameter and 1-mm thickness of translucent (Opallis Flow T, yellowed (Master Flow A2; Opallis Flow A2; Natural Flow A2; Fluroshield Yellowed, and opaque materials (Master Flow OA2; Natural Flow O; Opallis Flow OA3.5; Opallis Flow OP; Fluroshield White were obtained at six curing times (10s, 20s, 30s, 40s, 50s, and 60s using a high-intensity LED (Coltolux, Coltène/Whaledent. The degree of conversion (DC (% was obtained using the Nexus 470 FTIR Spectrometer (Nicolet Instruments, USA. The FTIR-ATR spectra for uncured and cured samples were analyzed using a ZnSe crystal. The top and bottom surfaces of the cured specimens were analyzed to obtain the depth of curing. Two-way ANOVA was used to analyze the data. The highest curing depth was obtained by Natural Flow OA2, while the lowest was shown by Master Flow OA2. The shortest curing time generated similar depths of cure in comparison with the most extensive for Opallis Flow A2 and Fluroshield Yellowed. Therefore, depth of curing, influenced by the irradiation time, was dependent on the materials. Using the Natural Flow OA2 opaque sealant and the 10-s curing time for Opallis Flow A2 and Fluroshield Yellowed may represent alternative approaches to sealing tooth fissures.

  1. Undercooling Limits and Thermophysical Properties in Glass Forming Alloys

    Science.gov (United States)

    Rhim, Won-Kyu; Ohsaka, Kenichi; Spjut, R. Erik

    1999-01-01

    The primary objective of this program is to produce deeply undercooled metallic liquids and to identify factors that limit undercooling and glass formation. The main research objectives are: (1) Investigating undercooling limits in glass-forming alloys and identifying factors that affect undercooling; (2) Measuring thermophysical properties and investigating the validity of the classical nucleation theory and other existing theories in the extreme undercooled states; and (3) To investigate the limits of electrostatic levitation technology in the ground base and to identify thermophysical parameters that might require reduced-g environment.

  2. The opacity of the universe for high and very high energy γ-rays

    International Nuclear Information System (INIS)

    Meyer, Manuel

    2013-08-01

    4σ level. A source intrinsic effect is unlikely to produce such a feature, since the transition to the τ γγ ≥2 regime occurs at different energies for each source. Systematic uncertainties that could mimic the effect are studied but found unlikely as a possible explanation. A similar study is conducted for photons detected with the Fermi-LAT. To this end, the number of expected photons in the optical thick regime is compared to the number of photons observed with the LAT. Above τ γγ ≥2, three photons are associated with AGN with high confidence. Under the assumption of certain EBL models, extrapolating the unattenuated spectrum from low to high energies results in a probability of 1.2 x 10 -4 to observe these photons. However, the probability for detecting the high optical depth photons when all LAT detected AGN with known redshift are considered sensitively depends on the choice of the intrinsic spectral model. The indication for a reduced opacity might be explained by the oscillation of photons into hypothetical axion-like particles (ALPs) in ambient magnetic fields. Such particles propagate unimpeded over cosmological distances, thereby reducing the γ-ray opacity. Photon-ALP conversions are studied in different magnetic field configurations, including intracluster and intergalactic magnetic fields, as well as the field of the Milky Way. Optimistic values of the field strength and coherence length result in lower limits on the photon-ALP coupling, g aγ >or similar 10 -12 GeV -1 . For more realistic magnetic field parameters, couplings above g aγ >or similar 2 x 10 11 GeV -1 are necessary to explain the indication for the reduced opacity. The lower limits are in reach of future dedicated ALP experiments. (orig.)

  3. The opacity of the universe for high and very high energy {gamma}-rays

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Manuel

    2013-08-15

    }{sub {gamma}{gamma}}<1 to {tau}{sub {gamma}{gamma}}{>=}2 is investigated. The absorption-corrected spectra consistently show an upturn at high optical depths, significant at the 4{sigma} level. A source intrinsic effect is unlikely to produce such a feature, since the transition to the {tau}{sub {gamma}{gamma}}{>=}2 regime occurs at different energies for each source. Systematic uncertainties that could mimic the effect are studied but found unlikely as a possible explanation. A similar study is conducted for photons detected with the Fermi-LAT. To this end, the number of expected photons in the optical thick regime is compared to the number of photons observed with the LAT. Above {tau}{sub {gamma}{gamma}}{>=}2, three photons are associated with AGN with high confidence. Under the assumption of certain EBL models, extrapolating the unattenuated spectrum from low to high energies results in a probability of 1.2 x 10{sup -4} to observe these photons. However, the probability for detecting the high optical depth photons when all LAT detected AGN with known redshift are considered sensitively depends on the choice of the intrinsic spectral model. The indication for a reduced opacity might be explained by the oscillation of photons into hypothetical axion-like particles (ALPs) in ambient magnetic fields. Such particles propagate unimpeded over cosmological distances, thereby reducing the {gamma}-ray opacity. Photon-ALP conversions are studied in different magnetic field configurations, including intracluster and intergalactic magnetic fields, as well as the field of the Milky Way. Optimistic values of the field strength and coherence length result in lower limits on the photon-ALP coupling, g{sub a{gamma}}>or similar 10{sup -12} GeV{sup -1}. For more realistic magnetic field parameters, couplings above g{sub a{gamma}}>or similar 2 x 10{sup 11} GeV{sup -1} are necessary to explain the indication for the reduced opacity. The lower limits are in reach of future dedicated ALP

  4. Low thermal expansion glass ceramics

    CERN Document Server

    1995-01-01

    This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...

  5. Fun with singing wine glasses

    Science.gov (United States)

    Boone, Christine; Galloway, Melodie; Ruiz, Michael J.

    2018-05-01

    A fun activity is presented using singing wine glasses for introductory physics students. Students tune a white wine glass and a red wine glass to as many semitones as possible by filling the glasses with the appropriate amounts of water. A smart phone app is used to measure the frequencies of equal-temperament tones. Then plots of frequency against water volume percent are made using a spreadsheet. Students can also play combinations of pitches with several glasses. A video (Ruiz 2018 Video: Singing glasses http://mjtruiz.com/ped/wineglasses/) is provided which includes an excerpt of a beautiful piece written for singing glasses and choir: Stars by Latvian composer Ēriks Ešenvalds.

  6. Bulk metallic glass matrix composites

    International Nuclear Information System (INIS)

    Choi-Yim, H.; Johnson, W.L.

    1997-01-01

    Composites with a bulk metallic glass matrix were synthesized and characterized. This was made possible by the recent development of bulk metallic glasses that exhibit high resistance to crystallization in the undercooled liquid state. In this letter, experimental methods for processing metallic glass composites are introduced. Three different bulk metallic glass forming alloys were used as the matrix materials. Both ceramics and metals were introduced as reinforcement into the metallic glass. The metallic glass matrix remained amorphous after adding up to a 30 vol% fraction of particles or short wires. X-ray diffraction patterns of the composites show only peaks from the second phase particles superimposed on the broad diffuse maxima from the amorphous phase. Optical micrographs reveal uniformly distributed particles in the matrix. The glass transition of the amorphous matrix and the crystallization behavior of the composites were studied by calorimetric methods. copyright 1997 American Institute of Physics

  7. The borosilicate glass for 'PAMELA'

    International Nuclear Information System (INIS)

    Schiewer, E.

    1986-01-01

    The low enriched waste concentrate (LEWC) stored at Mol, Belgium, will be solidified in the vitrification plant 'PAMELA'. An alkali-borosilicate glass was developed by the Hahn-Meitner-Institut, Berlin, which dissolves (11 +- 3)wt% waste oxides while providing sufficient flexibility for changes in the process parameters. The development of the glass labelled SM513LW11 is described. Important properties of the glass melt (viscosity, resistivity, formation of yellow phase) and of the glass (corrosion in aqueous solutions, crystallization) are reported. The corrosion data of this glass are similar to those of other HLW-glasses. Less than five wt% of crystalline material are produced upon cooling of large glass blocks. Crystallization does not affect the chemical durability. (Auth.)

  8. Ground water '89

    International Nuclear Information System (INIS)

    1989-01-01

    The proceedings of the 5th biennial symposium of the Ground Water Division of the Geological Society of South Africa are presented. The theme of the symposium was ground water and mining. Papers were presented on the following topics: ground water resources; ground water contamination; chemical analyses of ground water and mining and its influece on ground water. Separate abstracts were prepared for 5 of the papers presented. The remaining papers were considered outside the subject scope of INIS

  9. Production of glass or glass-ceramic to metal seals with the application of pressure

    Science.gov (United States)

    Kelly, Michael D.; Kramer, Daniel P.

    1987-11-10

    In a process for preparing a glass or glass-ceramic to metal seal comprising contacting the glass with the metal and heat-treating the glass and metal under conditions whereby the glass to metal seal is effected and, optionally, the glass is converted to a glass-ceramic, an improvement comprises carrying out the heat-treating step using hot isostatic pressing.

  10. Glasses for Mali

    CERN Multimedia

    PH Department

    2008-01-01

    We are collecting old pairs of glasses to take out to Mali, where they can be re-used by people there. The price for a pair of glasses can often exceed 3 months salary, so they are prohibitively expensive for many people. If you have any old spectacles you can donate, please put them in the special box in the ATLAS secretariat, Bldg.40-4-D01 before the Christmas closure on 19 December so we can take them with us when we leave for Africa at the end of the month. (more details in ATLAS e-news edition of 29 September 2008: http://atlas-service-enews.web.cern.ch/atlas-service-enews/news/news_mali.php) many thanks! Katharine Leney co-driver of the ATLAS car on the Charity Run to Mali

  11. Glass manufacturing through induction

    International Nuclear Information System (INIS)

    Boen, R.; Paya, B.; Roscini, M.; Fautrelle, Y.; Tuaz, F.; Delage, D.

    1991-01-01

    Oxides and glasses are electrical and thermal insulators, but show the characteristic of being weakly conductors of electricity when they are melt. It is then possible to heat them through HF induction. This interesting property allows the development of a melting process in cold crucible induction furnace. The process is being studied and developed by a consortium made up of CFEI, CEA Marcoule, ELECTRICITE DE FRANCE and MADYLAM laboratory. The studies include 2 parts: a) One experimental part to develop the technology and research for satisfying configurations, through a small size platform (10 to 30 kg/h). The long run continuous pouring melting tests made on different kinds of glass allow to go-on with industrial range units. b) One theoretical part to understand the magneto-thermo-hydraulic phenomenon hardly in relation with the heavy dependence of the physical characteristics (electrical and heat conductivities, viscosity) according to temperature. 6 refs., 4 figs [fr

  12. Glass matrix armor

    International Nuclear Information System (INIS)

    Calkins, N.C.

    1991-01-01

    This patent describes an armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the insides surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material

  13. Breaking the glass ceiling.

    Science.gov (United States)

    Lazarus, A

    1997-03-01

    The glass ceiling is a form of organizational bias and discrimination that prevents qualified professionals from achieving positions of top governance and leadership. This article examines glass ceiling barriers that keep physicians from the upper reaches of management. While these factors apply mainly to women and minority physicians in academia, and are attributable to sexual harassment and discrimination, physicians as a class are frequently denied executive management positions. Such denial results from inadequate preparation for a career in health care administration. Important issues in the professional development of physician executives include mentoring, training and education, administrative experience, and cultural and personality factors. All of those must be considered when making the transition from medicine to management.

  14. HLW immobilization in glass

    International Nuclear Information System (INIS)

    Leroy, P.; Jacquet-Francillon, N.; Runge, S.

    1992-01-01

    The immobilization of High Level Waste in glass in France is a long history which started as early as in the 1950's. More than 30 years of Research and Development have been invested in that field. Two industrial facilities are operating (AVM and R7) and a third one (T7), under cold testing, is planned to start active operation in the mid-92. While vitrification has been demonstrated to be an industrially mastered process, the question of the quality of the final waste product, i.e. the HLW glass, must be addressed. The scope of the present paper is to focus on the latter point from both standpoints of the R and D and of the industrial reality

  15. Nuclear traces in glass

    International Nuclear Information System (INIS)

    Segovia A, M. de N.

    1978-01-01

    The charged particles produce, in dielectric materials, physical and chemical effects which make evident the damaged zone along the trajectory of the particle. This damaged zone is known as the latent trace. The latent traces can be enlarged by an etching of the detector material. This treatment attacks preferently the zones of the material where the charged particles have penetrated, producing concavities which can be observed through a low magnification optical microscope. These concavities are known as developed traces. In this work we describe the glass characteristics as a detector of the fission fragments traces. In the first chapter we present a summary of the existing basic theories to explain the formation of traces in solids. In the second chapter we describe the etching method used for the traces development. In the following chapters we determine some chatacteristics of the traces formed on the glass, such as: the development optimum time; the diameter variation of the traces and their density according to the temperature variation of the detector; the glass response to a radiation more penetrating than that of the fission fragments; the distribution of the developed traces and the existing relation between this ditribution and the fission fragments of 252 Cf energies. The method which has been used is simple and cheap and can be utilized in laboratories whose resources are limited. The commercial glass which has been employed allows the registration of the fission fragments and subsequently the realization of experiments which involve the counting of the traces as well as the identification of particles. (author)

  16. Amorphous gauge glass theory

    International Nuclear Information System (INIS)

    Nielsen, H.B.; Bennett, D.L.

    1987-08-01

    Assuming that a lattice gauge theory describes a fundamental attribute of Nature, it should be pointed out that such a theory in the form of a gauge glass is a weaker assumption than a regular lattice model in as much as it is not constrained by the imposition of translational invariance; translational invariance is, however, recovered approximately in the long wavelength or continuum limit. (orig./WL)

  17. Polyamorphism in metalic glass.

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, H. W.; Liu, H. Z.; Cheng, Y. Q.; Wen, J.; Lee, P.L.; Luo, W.K.; Shastri, S.D.; Ma, E.; X-Ray Science Division; Johns Hopkins Univ.; Chinese Academy of Sciences

    2007-03-01

    A metal, or an alloy, can often exist in more than one crystal structure. The face-centered-cubic and body-centered-cubic forms of iron (or steel) are a familiar example of such polymorphism. When metallic materials are made in the amorphous form, is a parallel 'polyamorphism' possible? So far, polyamorphic phase transitions in the glassy state have been observed only in glasses involving directional and open (such as tetrahedral) coordination environments. Here, we report an in situ X-ray diffraction observation of a pressure-induced transition between two distinct amorphous polymorphs in a Ce{sub 55}Al{sub 45} metallic glass. The large density difference observed between the two polyamorphs is attributed to their different electronic and atomic structures, in particular the bond shortening revealed by ab initio modeling of the effects of f-electron delocalization. This discovery offers a new perspective of the amorphous state of metals, and has implications for understanding the structure, evolution and properties of metallic glasses and related liquids. Our work also opens a new avenue towards technologically useful amorphous alloys that are compositionally identical but with different thermodynamic, functional and rheological properties due to different bonding and structural characteristics.

  18. Diffusion in glass

    Energy Technology Data Exchange (ETDEWEB)

    Mubarak, A S

    1991-12-31

    Rutherford backscattering spectromertry technique (RBS) was used to characterize and investigate the depth distribution profiles of Ca-impurities of Ca-doped soda-time glass. The purposely added Ca-impurities were introduced inti the glass matrix by a normal ion exchange diffusion process. The measurements and analysis were performed using 2 MeV {sup 2}He{sup +} ions supplied from the University of Jordan Van de Graff acceierator (JOVAG). The normalized concetration versus depth profile distributions for the Ca-imourities were determined, both theoretically and experimentally. The theoretical treatment was carried out by setting up and soiving the diffusion equation under the conditions of the experiment. The resulting profiles are characterized by a compiementary error function. the theoretical treeatment was extended to include the various methods of enhancing the diffusion process, e.g. using an electric field. The diffusion coefficient, assumed constant, of the Ca-impurities exchanged in the soda-lime glass was determined to be 1.23 x 10{sup 13} cm{sup 2}/s. A comparison between theoretically and experimentally determined profiles is made and commented at, where several conclusions are drawn and suggestions for future work are mentioned. (author). 38 refs., 21 figs., 10 Tabs.

  19. Radiation shielding glass

    International Nuclear Information System (INIS)

    Kido, Kazuhiro; Ueda, Hajime.

    1997-01-01

    It was found that a glass composition comprising, as essential ingredients, SiO 2 , PbO, Gd 2 O 3 and alkali metal oxides can provide a shielding performance against electromagnetic waves, charged particles and neutrons. The present invention provides radiation shielding glass containing at least from 16 to 46wt% of SiO 2 , from 47 to 75wt% of PbO, from 1 to 10wt% of Gd 2 O 3 , from 0 to 3wt% of Li 2 O, from 0 to 7wt% of Na 2 O, from 0 to 7wt% of K 2 O provided that Li 2 O + Na 2 O + K 2 O is from 1 to 10wt%, B 2 O 3 is from 0 to 10wt%, CeO 2 is from 0 to 3wt%, As 2 O 3 is from 0 to 1wt% and Sb 2 O 3 is from 0 to 1wt%. Since the glass can shield electromagnetic waves, charged particles and neutrons simultaneously, radiation shielding windows can be designed and manufactured at a reduced thickness and by less constitutional numbers in a circumstance where they are present altogether. (T.M.)

  20. Helium behaviour in nuclear glasses

    International Nuclear Information System (INIS)

    Fares, T.

    2011-01-01

    The present thesis focuses on the study of helium behavior in R7T7 nuclear waste glass. Helium is generated by the minor actinides alpha decays incorporated in the glass matrix. Therefore, four types of materials were used in this work. These are non radioactive R7T7 glasses saturated with helium under pressure, glasses implanted with 3 He + ions, glasses doped with curium and glasses irradiated in nuclear reactor. The study of helium solubility in saturated R7T7 glass has shown that helium atoms are inserted in the glass free volume. The results yielded a solubility of about 10 16 at. cm -3 atm. -1 . The incorporation limit of helium in this type of glass has been determined; its value amounted to about 2*10 21 at. cm -3 , corresponding to 2.5 at.%. Diffusion studies have shown that the helium migration is controlled by the single population dissolved in the glass free volume. An ideal diffusion model was used to simulate the helium release data which allowed to determine diffusion coefficients obeying to the following Arrhenius law: D = D 0 exp(-E a /kBT), where D 0 = 2.2*10 -2 and 5.4*10 -3 cm 2 s -1 and E a = 0.61 eV for the helium saturated and the curium doped glass respectively. These results reflect a thermally activated diffusion mechanism which seems to be not influenced by the glass radiation damage and helium concentrations studied in the present work (up to 8*10 19 at. g -1 , corresponding to 0.1 at.%). Characterizations of the macroscopic, structural and microstructural properties of glasses irradiated in nuclear reactor did not reveal any impact associated with the presence of helium at high concentrations. The observed modifications i.e. a swelling of 0.7 %, a decrease in hardness by 38 %, an increase between 8 and 34 % of the fracture toughness and a stabilization of the glass structure under irradiation, were attributed to the glass nuclear damage induced by the irradiation in reactor. Characterizations by SEM and TEM of R7T7 glasses implanted

  1. Glass containing radioactive nuclear waste

    International Nuclear Information System (INIS)

    Boatner, L.A.; Sales, B.C.

    1985-01-01

    Lead-iron phosphate glasses containing a high level of Fe 2 O 3 for use as a storage medium for high-level-radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90 C, with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10 2 to 10 3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe 2 O 3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800 C, since they exhibit very low melt viscosities in the 800 to 1050 C temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550 C and are not adversely affected by large doses of gamma radiation in H 2 O at 135 C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear waste forms. (author)

  2. Analytical Plan for Roman Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, Denis M.; Buck, Edgar C.; Mueller, Karl T.; Schwantes, Jon M.; Olszta, Matthew J.; Thevuthasan, Suntharampillai; Heeren, Ronald M.

    2011-01-01

    Roman glasses that have been in the sea or underground for about 1800 years can serve as the independent “experiment” that is needed for validation of codes and models that are used in performance assessment. Two sets of Roman-era glasses have been obtained for this purpose. One set comes from the sunken vessel the Iulia Felix; the second from recently excavated glasses from a Roman villa in Aquileia, Italy. The specimens contain glass artifacts and attached sediment or soil. In the case of the Iulia Felix glasses quite a lot of analytical work has been completed at the University of Padova, but from an archaeological perspective. The glasses from Aquileia have not been so carefully analyzed, but they are similar to other Roman glasses. Both glass and sediment or soil need to be analyzed and are the subject of this analytical plan. The glasses need to be analyzed with the goal of validating the model used to describe glass dissolution. The sediment and soil need to be analyzed to determine the profile of elements released from the glass. This latter need represents a significant analytical challenge because of the trace quantities that need to be analyzed. Both pieces of information will yield important information useful in the validation of the glass dissolution model and the chemical transport code(s) used to determine the migration of elements once released from the glass. In this plan, we outline the analytical techniques that should be useful in obtaining the needed information and suggest a useful starting point for this analytical effort.

  3. Bioactive glass in tissue engineering

    Science.gov (United States)

    Rahaman, Mohamed N.; Day, Delbert E.; Bal, B. Sonny; Fu, Qiang; Jung, Steven B.; Bonewald, Lynda F.; Tomsia, Antoni P.

    2011-01-01

    This review focuses on recent advances in the development and use of bioactive glass for tissue engineering applications. Despite its inherent brittleness, bioactive glass has several appealing characteristics as a scaffold material for bone tissue engineering. New bioactive glasses based on borate and borosilicate compositions have shown the ability to enhance new bone formation when compared to silicate bioactive glass. Borate-based bioactive glasses also have controllable degradation rates, so the degradation of the bioactive glass implant can be more closely matched to the rate of new bone formation. Bioactive glasses can be doped with trace quantities of elements such as Cu, Zn and Sr, which are known to be beneficial for healthy bone growth. In addition to the new bioactive glasses, recent advances in biomaterials processing have resulted in the creation of scaffold architectures with a range of mechanical properties suitable for the substitution of loaded as well as non-loaded bone. While bioactive glass has been extensively investigated for bone repair, there has been relatively little research on the application of bioactive glass to the repair of soft tissues. However, recent work has shown the ability of bioactive glass to promote angiogenesis, which is critical to numerous applications in tissue regeneration, such as neovascularization for bone regeneration and the healing of soft tissue wounds. Bioactive glass has also been shown to enhance neocartilage formation during in vitro culture of chondrocyte-seeded hydrogels, and to serve as a subchondral substrate for tissue-engineered osteochondral constructs. Methods used to manipulate the structure and performance of bioactive glass in these tissue engineering applications are analyzed. PMID:21421084

  4. NEW ERBIUM DOPED ANTIMONY GLASSES FOR LASER AND GLASS AMPLIFICATION

    Directory of Open Access Journals (Sweden)

    B. Tioua

    2015-07-01

    Full Text Available Because of the special spectroscopic properties of the rare earth ions, rare earth doped glasses are widely used in bulk and fiber lasers or amplifiers. The modelling of lasers and searching for new laser transitions require a precise knowledge of the spectroscopic properties of rare earth ions in different host glasses. In this poster will offer new doped erbium glasses synthesized in silicate crucibles were obtained in the combination Sb2O3-WO3-Na2O. Several properties are measured and correlated with glass compositions. The absorption spectral studies have been performed for erbium doped glasses. The intensities of various absorption bands of the doped glasses are measured and the Judd-Ofelt parameters have been computed. From the theory of Judd-Ofelt, various radiative properties, such as transition probability, branching ratio and radiative life time for various emission levels of these doped glasses have been determined and reported. These results confirm the ability of antimony glasses for glass amplification.

  5. Mechanical failure and glass transition in metallic glasses

    International Nuclear Information System (INIS)

    Egami, T.

    2011-01-01

    Research highlights: → We review the recent results of molecular dynamics simulations on metallic glasses. → They show the equivalence of mechanical failure and glass transition. → We discuss the microscopic mechanism behind this equivalence. → We show that the density of defects in metallic glasses is as high as a quarter. → Our concepts about the defect state in glasses need to be changed. - Abstract: The current majority view on the phenomenon of mechanical failure in metallic glasses appears to be that it is caused by the activity of some structural defects, such as free-volumes or shear transformation zones, and the concentration of such defects is small, only of the order of 1%. However, the recent results compel us to revise this view. Through molecular dynamics simulation it has been shown that mechanical failure is the stress-induced glass transition. According to our theory the concentration of the liquid-like sites (defects) is well over 20% at the glass transition. We suggest that the defect concentration in metallic glasses is actually very high, and percolation of such defects causes atomic avalanche and mechanical failure. In this article we discuss the glass transition, mechanical failure and viscosity from such a point of view.

  6. Influence of Glass Property Restrictions on Hanford HLW Glass Volume

    International Nuclear Information System (INIS)

    Kim, Dong-Sang; Vienna, John D.

    2001-01-01

    A systematic evaluation of Hanford High-Level Waste (HLW) loading in alkali-alumino-borosilicate glasses was performed. The waste feed compositions used were obtained from current tank waste composition estimates, Hanford's baseline retrieval sequence, and pretreatment processes. The waste feeds were sorted into groups of like composition by cluster analysis. Glass composition optimization was performed on each cluster to meet property and composition constraints while maximizing waste loading. Glass properties were estimated using property models developed for Hanford HLW glasses. The impacts of many constraints on the volume of HLW glass to be produced at Hanford were evaluated. The liquidus temperature, melting temperature, chromium concentration, formation of multiple phases on cooling, and product consistency test response requirements for the glass were varied one- or many-at-a-time and the resultant glass volume was calculated. This study shows clearly that the allowance of crystalline phases in the glass melter can significantly decrease the volume of HLW glass to be produced at Hanford.

  7. Globular bodies: a primary cause of the opacity in senile and diabetic posterior cortical subcapsular cataracts?

    Science.gov (United States)

    Creighton, M O; Trevithick, J R; Mousa, G Y; Percy, D H; McKinna, A J; Dyson, C; Maisel, H; Bradley, R

    1978-07-01

    We examined 9 cataracts from maturity onset diabetics and 4 senile posterior subcapsular cataracts by scanning electron microscopy, transmission electron microscopy, immunofluorescence for crystallin proteins and actin, histochemical methods and x-ray diffraction. The cataractous regions contained spherical globules up to 20 mu in diameter, often in a fibrous matrix. Some were extracellular Morgagnian globules, apparently formed by blebbing from the cell surface; others appeared to have been formed intracellularly. The area of globular degeneration was usually 300 mu deep, but had deeper fusiform extensions. Morphological changes in the cell cytoplasm varied according to their depth in the cataract. Electron microscopy showed intracellular and extracellular globules, many of them were bounded by lipid bilayer membranes. Immunofluorescent staining showed that all the globules contained gamma-crystallin; some contained alpha- and beta-crystallins and actin. All the globules contained higher concentrations of cysteine or cystine than the surrounding lens tissue but they did not react to stains for carbohydrate or calcium. X-ray diffraction studies showed that crystalline calcium salts were absent. Globules and cavities averaged 45% of the total area in cross section. Assuming an area of cataract to be 300 micron thick and that globules 1 mu in diameter scattered, while 2--20 mu in diameter reflected light, we calculated that light passing through such a thickness would be reduced by 65%. Thus the globules could account for most of the opacity of the cataractous area. Presumably the fibrous degeneration of the cells causes enough light scattering to account for the remainder of the reduction. Cataract patients complain of decreased visual acuity, a golden halo around objects, and difficulties when driving while facing oncoming traffic at night. These probably result from light scattering. In our previous experiments, globular bodies containing gamma-crystallin were

  8. Abrasive wear of enamel by bioactive glass-based toothpastes.

    Science.gov (United States)

    Mahmood, Asad; Mneimne, Mohammed; Zou, Li Fong; Hill, Robert G; Gillam, David G

    2014-10-01

    To determine the abrasivity of a 45S5 bioactive glass based toothpaste on enamel as a function of the particle size and shape of the glass. 45S5 glass was synthesized ground and sieved to give various particle sized fractions toothpastes and their tooth brush abrasivity measured according to BS EN ISO11609 methodology. Enamel loss increased with increasing particle size. The percussion milled powder exhibited particles that had sharp edges and the pastes were significantly more abrasive than the pastes made with round ball milled powders. One interesting observation made during the present study was that there was preferential wear of the enamel at the dentin-enamel junction (DEJ), particularly with the coarse particle sized pastes.

  9. Analysis of glass fibre sizing

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

    2014-01-01

    Glass fibre reinforced polymer composites are widely used for industrial and engineering applications which include construction, aerospace, automotive and wind energy industry. During the manufacturing glass fibres, they are surface-treated with an aqueous solution. This process and the treated...... surfaces are called sizing. The sizing influences the properties of the interface between fibres and a matrix, and subsequently affects mechanical properties of composites. In this work the sizing of commercially available glass fibres was analysed so as to study the composition and chemical structures....... Soxhlet extraction was used to extract components of the sizing from the glass fibres. The glass fibres, their extracts and coated glass plates were analysed by Thermo-Gravimetric Analysis combined with a mass spectrometer (TGA-MS), and Attenuated Total Reflectance Fourier Transform Infrared (ATR...

  10. Low Thermal Expansion Glass Ceramics

    CERN Document Server

    Bach, Hans

    2005-01-01

    This book appears in the authoritative series reporting the international research and development activities conducted by the Schott group of companies. This series provides an overview of Schott's activities for scientists, engineers, and managers from all branches of industry worldwide in which glasses and glass ceramics are of interest. Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated. This new extended edition describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics. The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions. Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization. Thus g...

  11. Complexity of Curved Glass Structures

    Science.gov (United States)

    Kosić, T.; Svetel, I.; Cekić, Z.

    2017-11-01

    Despite the increasing number of research on the architectural structures of curvilinear forms and technological and practical improvement of the glass production observed over recent years, there is still a lack of comprehensive codes and standards, recommendations and experience data linked to real-life curved glass structures applications regarding design, manufacture, use, performance and economy. However, more and more complex buildings and structures with the large areas of glass envelope geometrically complex shape are built every year. The aim of the presented research is to collect data on the existing design philosophy on curved glass structure cases. The investigation includes a survey about how architects and engineers deal with different design aspects of curved glass structures with a special focus on the design and construction process, glass types and structural and fixing systems. The current paper gives a brief overview of the survey findings.

  12. Ground water and energy

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This national workshop on ground water and energy was conceived by the US Department of Energy's Office of Environmental Assessments. Generally, OEA needed to know what data are available on ground water, what information is still needed, and how DOE can best utilize what has already been learned. The workshop focussed on three areas: (1) ground water supply; (2) conflicts and barriers to ground water use; and (3) alternatives or solutions to the various issues relating to ground water. (ACR)

  13. The opacities of 12C-12C reaction and effect of deformed target nucleus on abrasion and absorption cross sections

    International Nuclear Information System (INIS)

    Ramadan, S.; Metawei, Z.

    1995-01-01

    The values of the opacities for 12 C- 12 C reaction are calculated at different incident ion kinetic energy. The exact multiple scattering series for the scattering of two heavy ions which was derived by wilson is used to calculate the abrasion and absorption cross sections of 16 O- 9 Be and 16 O- 16 O collisions, considering a harmonic oscillator matter density for both target and projectiles as spherical nuclei. The effect of including the pauli correlation is considered. The case of deformed target is also investigated. Our results are compared with other calculations as well as with the experimental results

  14. Experimental study on critical breaking stress of float glass under elevated temperature

    International Nuclear Information System (INIS)

    Wang, Yu; Wang, Qingsong; Shao, Guangzheng; Chen, Haodong; Sun, Jinhua; He, Linghui; Liew, K.M.

    2014-01-01

    Highlights: • Critical breaking stresses of clear, ground and coated glass were measured. • Breaking stress and strain of smooth glass were measured from 25 °C to 400 °C. • At approximately 100 °C, critical stress reached the minimum value. • Surface treatment and ambient temperature have notable effects on glass breaking. - Abstract: Cracking and subsequent fallout of glass may significantly affect fire dynamics in compartments. Moreover, the breaking tensile stress of glass, a crucial parameter for breakage occurrence, is the least well known among mechanical properties. In this work, a series of experiments were conducted, through mechanical tensile tests, to directly measure the breaking stress of float glass using Material Testing System 810 apparatus. Clear, ground and coated glass samples with a thickness of 6 mm were measured under ambient conditions, with a room temperature of 25 °C. The breaking stress of smooth glass samples was also measured at 75 °C, 100 °C, 125 °C, 150 °C, 200 °C, 300 °C and 400 °C, respectively. The results show that surface treatment may decrease the critical tensile stress of glass panes. The average breaking stress also fluctuates considerably, from 26.60 to 35.72 MPa with the temperature variations investigated here. At approximately 100 °C, critical stress reached the minimum value at which glass breakage occurs more easily. In addition, the thermal expansion coefficient was established using a thermal dilatometer, to obtain the maximum temperature difference float glass can withstand. It is intended that these results will provide some practical guidelines for fire safety engineers

  15. Electronic structure of metallic glasses

    International Nuclear Information System (INIS)

    Oelhafen, P.; Lapka, R.; Gubler, U.; Krieg, J.; DasGupta, A.; Guentherodt, H.J.; Mizoguchi, T.; Hague, C.; Kuebler, J.; Nagel, S.R.

    1981-01-01

    This paper is organized in six sections and deals with (1) the glassy transition metal alloys, their d-band structure, the d-band shifts on alloying and their relation to the alloy heat of formation (ΔH) and the glass forming ability, (2) the glass to crystal phase transition viewed by valence band spectroscopy, (3) band structure calculations, (4) metallic glasses prepared by laser glazing, (5) glassy normal metal alloys, and (6) glassy hydrides

  16. PLZT capacitor on glass substrate

    Science.gov (United States)

    Fairchild, M. Ray; Taylor, Ralph S.; Berlin, Carl W.; Wong, Celine W. K.; Ma, Beihai; Balachandran, Uthamalingam

    2016-01-05

    A lead-lanthanum-zirconium-titanate (PLZT) capacitor on a substrate formed of glass. The first metallization layer is deposited on a top side of the substrate to form a first electrode. The dielectric layer of PLZT is deposited over the first metallization layer. The second metallization layer deposited over the dielectric layer to form a second electrode. The glass substrate is advantageous as glass is compatible with an annealing process used to form the capacitor.

  17. Glass corrosion in natural environments

    Science.gov (United States)

    Thorpe, Arthur N.; Barkatt, Aaron

    1992-01-01

    Experiments carried out during the progress period are summarized. Experiments carried out involving glass samples exposed to solutions of Tris have shown the appearance of 'spikes' upon monitoring glass dissolution as a function of time. The periodic 'spikes' observed in Tris-based media were interpreted in terms of cracking due to excessive stress in the surface region of the glass. Studies of the interactions of silicate glasses with metal ions in buffered media were extended to systems containing Al. Caps buffer was used to establish the pH. The procedures used are described and the results are given. Preliminary studies were initiated as to the feasibility of adding a slowly dissolving solid compound of the additive to the glass-water system to maintain a supply of dissolved additive. It appears that several magnesium compounds have a suitable combination of solubility and affinity towards silicate glass surfaces to have a pronounced retarding effect on the extraction of uranium from the glass. These preliminary findings raise the possibility that introducing a magnesium source into geologic repositories for nuclear waste glass in the form of a sparingly soluble Mg-based backfill material may cause a substantial reduction in the extent of long-term glass corrosion. The studies described also provide mechanistic understanding of the roles of various metal solutes in the leachant. Such understanding forms the basis for developing long-term predictions of nuclear waste glass durability under repository conditions. From what is known about natural highly reduced glasses such as tektites, it is clear that iron is dissolved as ferrous iron with little or no ferric iron. The reducing conditions were high enough to cause metallic iron to exsolve out of the glass in the form of submicroscopic spherules. As the nuclear waste glass is much less reduced, a study was initiated on other natural glasses in addition to the nuclear waste glass. Extensive measurements were

  18. Crystallization of copper metaphosphate glass

    Science.gov (United States)

    Bae, Byeong-Soo; Weinberg, Michael C.

    1993-01-01

    The effect of the valence state of copper in copper metaphosphate glass on the crystallization behavior and glass transition temperature has been investigated. The crystallization of copper metaphosphate is initiated from the surface and its main crystalline phase is copper metaphosphate (Cu(PO)3),independent of the (Cu sup 2+)/(Cu(total)). However, the crystal morphology, the relative crystallization rates, and their temperature dependences are affected by the (Cu sup 2+)/(Cu (total)) ratio in the glass. On the other hand, the totally oxidized glass crystallizes from all over the surface. The relative crystallization rate of the reduced glass to the totally oxidized glass is large at low temperature, but small at high temperature. The glass transition temperature of the glass increases as the (Cu sup 2+)/(Cu(total)) ratio is raised. It is also found that the atmosphere used during heat treatment does not influence the crystallization of the reduced glass, except for the formation of a very thin CuO surface layer when heated in air.

  19. Fabrication of Radiation Shielding Glass

    International Nuclear Information System (INIS)

    Tavichai, Nattaya; Pormsean, Suriyont; Dararutana, Pisutti; Sirikulrat, Narin

    2003-06-01

    In this work, lead glass doped with 50%, 55%,60%, 65%, and 70% w/w Pb 3 O 4 . After that, glass mixtures were melt at 1,250οC with 4 hours soaking time. Molten glass was shaped by mould casting technique then annealed at 700οC and cooled down to room temperature. It was found that the glass with 60%w/w Pb 3 O 4 show maximum absorption coefficient of about 0.383 cm -1 with I-131 at energy 364 keV. The observed refractive indices of the samples range between 1.5908 to 1.5922

  20. Compositional threshold for Nuclear Waste Glass Durability

    International Nuclear Information System (INIS)

    Kruger, Albert A.; Farooqi, Rahmatullah; Hrma, Pavel R.

    2013-01-01

    Within the composition space of glasses, a distinct threshold appears to exist that separates 'good' glasses, i.e., those which are sufficiently durable, from 'bad' glasses of a low durability. The objective of our research is to clarify the origin of this threshold by exploring the relationship between glass composition, glass structure and chemical durability around the threshold region

  1. Restorative Glass : Reversible, discreet restoration using structural glass components

    NARCIS (Netherlands)

    Oikonomopoulou, F.; Bristogianni, T.; Barou, L.; van Hees, R.P.J.; Nijsse, R.; Veer, F.A.; Henk, Schellen; van Schijndel, Jos

    2016-01-01

    The application of structural glass as the principal material in restoration and conservation practices is a distinguishable, yet discreet approach. The transparency of glass allows the simultaneous perception of the monument at both its original and present condition, preserving its historical and

  2. New Erbium Doped Antimony Glasses for Laser and Glass ...

    African Journals Online (AJOL)

    Because of the special spectroscopic properties of the rare earth ions, rare earth doped glasses are widely used in bulk and fiber lasers or amplifiers. The modelling of lasers and searching for new laser transitions require a precise knowledge of the spectroscopic properties of rare earth ions in different host glasses.

  3. The glass sphinx: a massive stacked glass structure

    NARCIS (Netherlands)

    Bos, F.P.; Heijden, van der T.; Schreurs, P.; Bos, F.; Louter, C.; Nijsse, R.; Veer, F.

    The refurbishment of the Meuse river boulevard in Venlo instigated Scheuten Glass to donate a giant-sized, 6 metre high version of the stacked glass statue the Sphinx, which had originally been made as a 80 cm sculpture to commemorate the city's 650th anniversary back in 1993. Many hurdles had to be

  4. Structural Glass Beams with Embedded Glass Fibre Reinforcement

    NARCIS (Netherlands)

    Louter, P.C.; Leung, Calvin; Kolstein, M.H.; Vambersky, J.N.J.A.; Bos, Freek; Louter, Pieter Christiaan; Veer, Fred

    2010-01-01

    This paper investigates the possibilities of pultruded glass fibre rods as embedded reinforcement in SentryGlas (SG) laminated glass beams. To do so, a series of pullout tests, to investigate the bond strength of the rods to the laminate, and a series of beam tests, to investigate the post-breakage

  5. Gas and dust in the star-forming region ρ Oph A. The dust opacity exponent β and the gas-to-dust mass ratio g2d

    Science.gov (United States)

    Liseau, R.; Larsson, B.; Lunttila, T.; Olberg, M.; Rydbeck, G.; Bergman, P.; Justtanont, K.; Olofsson, G.; de Vries, B. L.

    2015-06-01

    Aims: We aim at determining the spatial distribution of the gas and dust in star-forming regions and address their relative abundances in quantitative terms. We also examine the dust opacity exponent β for spatial and/or temporal variations. Methods: Using mapping observations of the very dense ρ Oph A core, we examined standard 1D and non-standard 3D methods to analyse data of far-infrared and submillimetre (submm) continuum radiation. The resulting dust surface density distribution can be compared to that of the gas. The latter was derived from the analysis of accompanying molecular line emission, observed with Herschel from space and with APEX from the ground. As a gas tracer we used N2H+, which is believed to be much less sensitive to freeze-out than CO and its isotopologues. Radiative transfer modelling of the N2H+ (J = 3-2) and (J = 6-5) lines with their hyperfine structure explicitly taken into account provides solutions for the spatial distribution of the column density N(H2), hence the surface density distribution of the gas. Results: The gas-to-dust mass ratio is varying across the map, with very low values in the central regions around the core SM 1. The global average, = 88, is not far from the canonical value of 100, however. In ρ Oph A, the exponent β of the power-law description for the dust opacity exhibits a clear dependence on time, with high values of 2 for the envelope-dominated emission in starless Class -1 sources to low values close to 0 for the disk-dominated emission in Class III objects. β assumes intermediate values for evolutionary classes in between. Conclusions: Since β is primarily controlled by grain size, grain growth mostly occurs in circumstellar disks. The spatial segregation of gas and dust, seen in projection toward the core centre, probably implies that, like C18O, also N2H+ is frozen onto the grains. Based on observations with APEX, which is a 12 m diameter submillimetre telescope at 5100 m altitude on Llano Chajnantor

  6. Glass ceramic fibres

    International Nuclear Information System (INIS)

    Blaschek, O.; Paulitsch, P.

    1983-01-01

    As the correlation between mineralogical phase and chemical composition influences the type of application at different high temperatures, we studied the mineralogical phases of nine crystal glass fibres of the temperature ranges 1 150 degrees Celsius (Type 1), 1 400 degrees Celsius (Type 2) and 1 500 degrees Celsius (Type 3) at various high temperatures. The methods used in the study were microscopy, X-ray diffraction, transmission electron microscopy and differential thermal analysis. The investigations showed that mullite forms in glassy fibres of the system Al 2 O 3 . SiO 2 from 850 degrees Celsius to 990 degrees Celsius as 2/1 mullite; 3/2 mullite appeared above 990 degrees Celsius besides the crystallization of cristobalite. Fibres with 95 per cent Al 2 O 3 include the phases delta-Al 2 O 3 and alpha- Al 2 O 3 and mullite. Delta- Al 2 O 3 is stable up to 1 100 degrees Celsius. Alpha-Al 2 O 3 and mullite are only stable phases at 1 400 degrees Celsius. These different crystal phases influence the quality of the technical fibre according to the stability field of glass and crystals. This study has determined that it is possible to identify different fibres from different productions by their mineralogical compositions and to relate them to the high temperature application

  7. Spheroidization of glass powders for glass ionomer cements.

    Science.gov (United States)

    Gu, Y W; Yap, A U J; Cheang, P; Kumar, R

    2004-08-01

    Commercial angular glass powders were spheroidized using both the flame spraying and inductively coupled radio frequency plasma spraying techniques. Spherical powders with different particle size distributions were obtained after spheroidization. The effects of spherical glass powders on the mechanical properties of glass ionomer cements (GICs) were investigated. Results showed that the particle size distribution of the glass powders had a significant influence on the mechanical properties of GICs. Powders with a bimodal particle size distribution ensured a high packing density of glass ionomer cements, giving relatively high mechanical properties of GICs. GICs prepared by flame-spheroidized powders showed low strength values due to the loss of fine particles during flame spraying, leading to a low packing density and few metal ions reacting with polyacrylic acid to form cross-linking. GICs prepared by the nano-sized powders showed low strength because of the low bulk density of the nano-sized powders and hence low powder/liquid ratio of GICs.

  8. CON4EI: Bovine Corneal Opacity and Permeability (BCOP) test for hazard identification and labelling of eye irritating chemicals.

    Science.gov (United States)

    Verstraelen, Sandra; Maglennon, Gareth; Hollanders, Karen; Boonen, Francis; Adriaens, Els; Alépée, Nathalie; Drzewiecka, Agnieszka; Gruszka, Katarzyna; Kandarova, Helena; Willoughby, Jamin A; Guest, Robert; Schofield, Jane; Van Rompay, An R

    2017-10-01

    Assessment of ocular irritation potential is an international regulatory requirement in the safety evaluation of industrial and consumer products. None in vitro ocular irritation assays are capable of fully categorizing chemicals as stand-alone. Therefore, the CEFIC-LRI-AIMT6-VITO CON4EI consortium assessed the reliability of eight in vitro test methods and computational models as well as established a tiered-testing strategy. One of the selected assays was Bovine Corneal Opacity and Permeability (BCOP). In this project, the same corneas were used for measurement of opacity using the OP-KIT, the Laser Light-Based Opacitometer (LLBO) and for histopathological analysis. The results show that the accuracy of the BCOP OP-KIT in identifying Cat 1 chemicals was 73.8% while the accuracy was 86.3% for No Cat chemicals. BCOP OP-KIT false negative results were often related to an in vivo classification driven by conjunctival effects only. For the BCOP LLBO, the accuracy in identifying Cat 1 chemicals was 74.4% versus 88.8% for No Cat chemicals. The BCOP LLBO seems very promising for the identification of No Cat liquids but less so for the identification of solids. Histopathology as an additional endpoint to the BCOP test method does not reduce the false negative rate substantially for in vivo Cat 1 chemicals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Factors controlling crystallization of miserite glass-ceramic.

    Science.gov (United States)

    Muhammed, Fenik K; Moorehead, Robert; van Noort, Richard; Pollington, Sarah

    2015-12-01

    The purpose of this study was to investigate a range of variables affecting the synthesis of a miserite glass-ceramic (GC). Miserite glass was synthesized by the melt quench technique. The crystallization kinetics of the glass were determined using Differential Thermal Analysis (DTA). The glasses were ground with dry ball-milling and then sieved to different particle sizes prior to sintering. These particle sizes were submitted to heat treatment regimes in a high temperature furnace to form the GC. The crystal phases of the GC were analyzed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) was used to examine the microstructure of the cerammed glass. XRD analysis confirmed that the predominant crystalline phase of the GC was miserite along with a minor crystalline phase of cristobalite only when the particle size is <20 μm and the heat treatment at 1000°C was carried out for 4h and slowly cooled at the furnace rate. For larger particle sizes and faster cooling rates, a pseudowollastonite crystalline phase was produced. Short sintering times produced either a pseudowollastonite or xonotolite crystalline phase. The current study has shown that particle size and heat treatment schedules are major factors in controlling the synthesis of miserite GC. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. MERS-CoV: Middle East respiratory syndrome corona virus: Can radiology be of help? Initial single center experience

    Directory of Open Access Journals (Sweden)

    Ahmed Hamimi

    2016-03-01

    Conclusions: MERS CoV virus may have a specific pattern in chest X-ray and CT developing a single or multiple opacities progressing into a widespread multifocal bilateral patches of ground glass opacities or confluent consolidation resembling organizing pneumonia.

  11. Characterization and Morphological Properties of Glass Fiber ...

    African Journals Online (AJOL)

    PROF HORSFALL

    used as the matrix for the glass fibre-epoxy resin formation. E- Glass fibre ... reinforcement of composites, coatings of materials, and other ..... composite for the manufacture of glass-ceramic materials ... reinforced epoxy composites with carbon.

  12. Optical properties of alkaline earth borate glasses

    African Journals Online (AJOL)

    user

    The alkaline earth borate glasses containing heavy metal oxides show good solubility of rare-earth ions. Glasses containing PbO exhibit low glass transition temperature (Tg) and high ..... These oxygen ions carry a partial negative charge and.

  13. Optical properties of alkaline earth borate glasses

    African Journals Online (AJOL)

    user

    ... devices; radiation shields, surgical lasers and their glass ceramic counter ... Alkaline earth oxides improve glass forming capability while heavy metal ... reports on optical properties of MO-B2O3 glasses containing alkaline earth oxides.

  14. Properties of gallium lanthanum sulphide glass

    OpenAIRE

    Bastock, P.; Craig, C.; Khan, K.; Weatherby, E.; Yao, J.; Hewak, D.W.

    2015-01-01

    A series of gallium lanthanum sulphide (GLS) glasses has been studied in order to ascertain properties across the entire glass forming region. This is the first comprehensive study of GLS glass over a wide compositional range.

  15. Who will buy smart glasses?

    DEFF Research Database (Denmark)

    Rauschnabel, Philipp; Brem, Alexander; Ivens, Bjørn S.

    2015-01-01

    Recent market studies reveal that augmented reality (AR) devices, such as smart glasses, will substantially influence the media landscape. Yet, little is known about the intended adoption of smart glasses, particularly: Who are the early adopters of such wearables? We contribute to the growing bo...

  16. Superconductive analogue of spin glasses

    International Nuclear Information System (INIS)

    Feigel'man, M.; Ioffe, L.; Vinokur, V.; Larkin, A.

    1987-07-01

    The properties of granular superconductors in magnetic fields, namely the existence of a new superconductive state analogue of the low-temperature superconductive state in spin glasses are discussed in the frame of the infinite-range model and the finite-range models. Experiments for elucidation of spin-glass superconductive state in real systems are suggested. 30 refs

  17. Zirconium based bulk metallic glasses

    International Nuclear Information System (INIS)

    Dey, G.K.; Neogy, S.; Savalia, R.T.; Tewari, R.; Srivastava, D.; Banerjee, S.

    2006-01-01

    Metallic glasses have come into prominence in recent times because their nanocrystalline atomic arrangement imparts many useful and unusual properties to these metallic solids. In this study, bulk glasses have been obtained in Zr based multicomponent alloy by induction melting these alloys in silica crucibles and casting these in form of rods 3 and 6 mm in diameter in a copper mould

  18. International Congress on Glass XII

    Energy Technology Data Exchange (ETDEWEB)

    Doremus, R H; LaCourse, W C; Mackenzie, J D; Varner, J R; Wolf, W W [eds.

    1980-01-01

    A total of 158 papers are included under nine headings: structure and glass formation; optical properties; electrical and magnetic properties; mechanical properties and relaxation; mass transport; chemical durability and surfaces; nucleation; crystallization; and glass ceramics; processing; and automatic controls. Separate abstracts were prepared for eight papers; four of the remaining papers had been processed previously for the data base. (DLC)

  19. OPAL Various Lead Glass Blocks

    CERN Multimedia

    These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

  20. Lead-iron phosophate glass

    International Nuclear Information System (INIS)

    Sales, B.C.; Boatner, L.A.

    1988-01-01

    The lead-iron phosphate nuclear waste glasses (LIPNWG) are the subject of the present chapter. They were discovered in 1984 while the authors were attempting to find a sintering aid for certain types of crystalline monazite ceramic high-level nuclear waste forms. In the present chapter, the term waste glass is synonymous with nuclear waste glass (NWG), and the acronym LIP is often used for lead-iron phosphate. Lead-iron phosphate glasses, like many of the previously studied phosphate glasses, are corrosion resistant in aqueous solutions at temperatures below 100 degrees C, and they can be melted and poured at temperatures that are relatively low in comparison with the processing temperatures required for current silicate glass compositions. Unlike the phosphate glasses investigated previously, however, LIPNWGs do not suffer from alteration due to devitrification during realistic and readily, achievable cooling periods. Additionally, lead-iron phosphate glass melts are not nearly as corrosive as the sodium phosphate melts investigated during the 1960s; and, therefore, they can be melted and processed using crucibles made from a variety of materials