Effect of Strength Mismatch of Girth Weld on Safety of the West-East Pipeline

2002 ◽  
Author(s):  
Chuanjing Zhuang
Keyword(s):  
Mechanical Test ◽  
Pipeline Steel ◽  
Large Diameter ◽  
Limit Load ◽  
Low Grade ◽  
High Grade ◽  
Test Results ◽  
The West ◽  
Transmission Pipeline ◽  
Grade Steel

The West-East Pipeline is the first of high-pressure, high-grade steel (X70) and large diameter (Φ1016mm) gas transmission pipeline in China. Evidently, Safety of the Pipeline is the most important case that the gas company have to take care of. Previous study showed that strength mismatch of girth weld had great effect on the integrity of the pipeline. Overmatch is preferred for low-grade pipeline (steel grade is usually X60 or lower). As to the high-grade pipeline, in order to reduce the sensitivity of cold crack, hydrogen induced crack (HIC) and stress induced corrosion crack (SCC), etc., under-matched girth weld is recommended somewhere. In this paper, based on a lot of mechanical test results, the effect of different mismatched girth weld on property of the West-East Pipeline is analyzed. The study indicated that mismatch of girth weld has effect on property of the Pipeline, such as limit load, fracture toughness and threshold defect sizes, etc. According to the research results, some advices are presented for design, maintenance and repair of the Pipeline.

Effect of thread pitch on the fatigue strength of steel bolts

1997 ◽  
Vol 211 (8) ◽  
pp. 591-600 ◽  
Author(s):  
E Dragoni
Keyword(s):  
Fatigue Strength ◽  
Stress Concentration ◽  
Load Capacity ◽  
Low Grade ◽  
High Grade ◽  
Thread Pitch ◽  
Steel Grades ◽  
Steel Bolts ◽  
Selection Of ◽  
Grade Steel

The paper explores the effect of the thread pitch on the fatigue strength of ISO steel bolts fitted with standard nuts. By means of boundary element analyses and cross-comparison with theory and photoelasticity, the load capacity of the bolt is ultimately related to a comprehensive notch factor which embodies both stress concentration and notch sensitivity dependencies. The notch factor is conveniently plotted as a function of nominal diameter and thread pitch for a selection of steel grades. The charts show that the endurance load slightly increases as the pitch is decreased for small bolts of low-grade steel. Conversely, the endurance load markedly increases with the pitch (improvements above 40 per cent can be achieved) for large bolts of high-grade steel.

scholarly journals Improved IMU Preintegration with Gravity Change and Earth Rotation for Optimization-Based GNSS/VINS

2020 ◽  
Vol 12 (18) ◽  
pp. 3048
Author(s):  
Junxiang Jiang ◽  
Xiaoji Niu ◽  
Jingnan Liu
Keyword(s):  
Earth Rotation ◽  
Information Matrix ◽  
Limited Range ◽  
Gravity Change ◽  
Low Grade ◽  
High Grade ◽  
Test Results ◽  
Bias Estimation ◽  
The Earth ◽  
Sensor Platform

IMU preintegration technology has been widely used in the optimization-based sensor fusion framework, in order to avoid reintegrating the high-frequency IMU measurements at each iteration and maintain the ability of bias correction when bias estimation changes. Since IMU preintegration technology was first proposed, several improved versions have been designed by changing the attitude parameterization or the numerical integration method in the most current related research. However, all of these versions have failed to take the change of gravity and the earth rotation into consideration. In this paper, we redesign the IMU preintegration algorithm in which the earth rotation and gravity vector are calculated from the geodetic position. Compared with the covariance matrix form, in this paper, the uncertainty of the preintegrated IMU measurements is propagated in the form of a square root information matrix (SRIM) for better numerical stability and easy use in the optimization-based framework. We evaluate the improved IMU preintegration algorithm by using the dataset collected by our sensor platform equipped with two different-grade IMUs. The test results show that the improved IMU preintegration algorithm can cope well with the gravity change and earth rotation. The earth rotation must be taken into consideration for the high-grade IMU that can effectively sense the earth rotation. If the change of gravity is omitted, the root-mean-square error (RMSE) of the horizontal attitude is about 1.38 times greater than the geodetic displacement. Additionally, the positioning RMSE does not increase obviously within a limited range, which means tens of kilometers and several hundred meters for the low-grade and high-grade IMU used in the experiment, respectively.

Evaluation Method of Large Inclusions in High-Grade Pipeline Steel

2013 ◽  
Author(s):  
Yan-hua Li ◽  
Hai-tao Wang ◽  
Ling-kang Ji ◽  
Qiang Chi ◽  
Hong-yuan Chen
Keyword(s):  
Evaluation Method ◽  
Oil And Gas ◽  
Pipeline Steel ◽  
Internal Quality ◽  
Pipeline System ◽  
High Grade ◽  
Efficient Operation ◽  
Steel Pipes ◽  
Transmission Pipeline

Good internal quality of steel pipes is a basic guarantee for the safe and efficient operation of pipeline system. While presence of large inclusions has adverse effect on the mechanical properties, weldability and corrosion resistance of the steel pipes, and then it would bring huge risk to the safe operation of oil and gas transmission pipeline. In order to reduce the risk to a minimum extent, it is quite necessary to analysis and study the characteristics of large inclusions in high grade pipeline steel, and then it would provide evidence for the formulation of level-determination standard of large inclusions during steel pipe acceptance. Optimized production technology such as electromagnetic stirring is put forward accordingly to prevent the occurrence of large inclusions in pipeline steel.

scholarly journals Biomarkers in Cervical Cancer Screening

2007 ◽  
Vol 23 (4) ◽  
pp. 315-330 ◽  
Author(s):  
Nicolas Wentzensen ◽  
Magnus von Knebel Doeberitz
Keyword(s):  
Cervical Cancer ◽  
Cancer Screening ◽  
Cervical Cancer Screening ◽  
Cancer Progression ◽  
Substantial Reduction ◽  
Low Grade ◽  
High Grade ◽  
Test Results ◽  
Screening Programs ◽  
Work Up

In industrialized countries, population wide cytological screening programs using the Pap test have led to a substantial reduction of the incidence of cervical cancer. Despite this evident success, screening programs that rely on Pap-stained cytological samples have several limitations. First, a number of equivocal or mildly abnormal test results require costly work up by either repeated retesting or direct colposcopy and biopsy, since a certain percentage of high grade lesions that require immediate treatment hide among these unclear test results. This work up of mildly abnormal or equivocal cytological tests consumes a large amount of the overall costs spent for cervical cancer screening. Improved triage of these samples might substantially reduce the costs. Cervical cancer is induced by persistent infections with oncogenic human papilloma viruses (HPV). While HPV infection is an indispensable factor, it is not sufficient to cause cancer. The majority of acute HPV infections induce low grade precursor lesions that are cleared spontaneously after several months in more than 90% of cases, and less than 10% eventually progress to high grade lesions or invasive cancer. Progression is characterized by the deregulated expression of the viral oncogenes E6 and E7 in infected basal and parabasal cells. Novel biomarkers that allow monitoring these essential molecular events in histological or cytological specimens are likely to improve the detection of lesions that have a high risk of progression in both primary screening and triage settings. In this review, we will discuss potential biomarkers for cervical cancer screening with a focus on the level of clinical evidence that supports their application as novel markers in refined cervical cancer screening programs.

Only a Small Fraction of High-Grade Cervical Lesions Are Discovered After an Interpretation of Atypical Squamous Cells of Undetermined Significance When Using Imager-Assisted, Liquid-Based Papanicolaou Tests and the Bethesda 2001 System

2012 ◽  
Vol 137 (7) ◽  
pp. 936-941 ◽  
Author(s):  
Kelly A. Khan ◽  
Debora A. Smith ◽  
Michael J. Thrall
Keyword(s):  
Low Grade ◽  
High Grade ◽  
Test Results ◽  
Squamous Intraepithelial Lesion ◽  
Squamous Intraepithelial Lesions ◽  
Papanicolaou Test ◽  
Squamous Cells ◽  
Intraepithelial Lesion ◽  
Intraepithelial Lesions ◽  
Undetermined Significance

Context.—Previous work has reported that most high-grade cervical neoplasia is seen in patients with preceding Papanicolaou test results of atypical squamous cells of undetermined significance. This information was based on conventional test results and the Bethesda 1991 reporting system and was determined before the current treatment guidelines. Objective.—Our objective was to perform a retrospective review of all histologically confirmed, high-grade cervical neoplasia to determine the diagnosis of the preceding liquid-based Papanicolaou test. Design.—A total of 189 histologically confirmed, high-grade cervical intraepithelial neoplasia (CIN) cases grade 2 and greater were identified for a 1-year period. Results.—Of the 189 cases, 10 (5.3%) had a previous diagnosis of atypical squamous cells of undetermined significance; 55 (29.1%) had low-grade squamous intraepithelial lesions; 31 (16.4%) had low-grade squamous intraepithelial lesions, unable to rule out a high-grade squamous intraepithelial lesion; 21 (11.1%) had atypical squamous cells, unable to rule out a high-grade squamous intraepithelial lesion; 68 (36%) had high-grade squamous intraepithelial lesions; 1 (0.5%) had atypical glandular cells; 1 (0.5%) had adenocarcinoma in situ; and 2 (1%) had invasive carcinoma. Combined “low grade” Papanicolaou test results (atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesion) preceded 51 of 103 cases of CIN 2 (49.5%) and 14 of 103 cases (13.6%) of CIN 3/cancer, whereas “high grade” Papanicolaou test results (atypical squamous cells, unable to rule out a high-grade squamous intraepithelial lesion; low-grade squamous intraepithelial lesions, unable to rule out a high-grade squamous intraepithelial lesion; high-grade squamous intraepithelial lesions; atypical glandular cells; adenocarcinoma in situ; and invasive carcinoma) preceded 52 of 103 CIN 2 cases (50.5%) and 72 of 103 CIN 3/cancer cases (69.9%). Conclusions.—Our data show that we can now more-reliably predict high-grade dysplasia on routine Papanicolaou tests. Only a small fraction of histologically confirmed CIN 2/3 cases are found following a Papanicolaou test diagnosis of atypical squamous cells of undetermined significance.

Klinische Wertigkeit der Positronen-Emissions-Tomographie (PET) bei onkologischen Fragestellungen: Ergebnisse einer interdisziplinären Konsensuskonferenz

1996 ◽  
Vol 35 (02) ◽  
pp. 42-52 ◽  
Author(s):  
R. Bares ◽  
U. Bull ◽  
A. Guhlmann ◽  
E. Moser ◽  
M. F. Wannenmacher ◽  
...  
Keyword(s):  
Low Grade ◽  
High Grade ◽  
Klinische Anwendung ◽  
Wissenschaftliche Studien

Zusammenfassung Ziel: Es ist das Ziel der vorliegenden Arbeit, an Hand bisher publizierter Studienergebnisse eine Beurteilung des klinischen Stellenwertes von PET in der Onkologie zu erarbeiten. Methoden: Im Rahmen einer interdisziplinären Konferenz mit namhaften Experten wurde eine Wertung des gegenwärtigen Stands von PET in der Onkologie an Hand der in der Literatur dokumentierten Studienergebnisse erarbeitet. Angestrebt wurde eine differenzierte Bewertung von PET für die klinische Anwendung in fünf Klassen (1a, 1b, 2a, 2b, 3) von »angemessen« (1a), »akzeptabel« (1b), »hilfreich« (2a), »noch keine Bewertung möglich« (2b), »ohne Nutzen« (3). Ergebnisse: Für den klinischen Einsatz in der Onkologie ist 2-F18-Fluorodeoxyglukose (FDG) das Radiopharmakon der Wahl. PET ist klinisch in der Patientenversorgung zur Rezidivdiagnostik von high-grade Gliomen (FDG), low-grade Gliomen (C-11 Methionin oder F-18 Tyrosin), für die Dignitätsdiagnostik des peripheren Lungenrundherdes bei Risikopatienten sowie für die Diagnostik des Pankreaskarzioms indiziert (Indikation 1a). PET kann in der Patientenversorgung bei folgenden Indikationen (1b) eingesetzt werden: »low-grade« Gliome, Suche nach unbekanntem Primärtumor bei Kopf-Hals-Tumoren, Rezidivdiagnostik des nicht kleinzelligen Bronchialkarzinoms sowie des Rektumkarzinoms, Lymphknotenstaging beim nicht kleinzelligen Bronchial-Karzinom, Pan-kreas-Karzinom, muskelinvasiven Blasen-Karzinom und Hoden-Karzinom. Staging bei M. Hodgkin (Stad. I/II versus III), frühe Therapiekontrolle bei Resttumor und Rezidivdiagnostik bei M. Hodgkin und hochmalignen Non-Hodgkin-Lymphomen, Lymphknoten-Staging und Fern-metastasensuche beim malignen Melanom (Breslow >1,5 mm), Lymphknoten- und Fernmetastasen-Nachweis beim Schilddrüsen-Karzinommit erhöhtem hTg und nicht radiojodspeichernden Metastasen. Zahlreiche weitere Indikationen zeichnen sich bereits jetzt ab, sind jedoch noch weniger gut durch wissenschaftliche Studien belegt. Für die meisten Indikationen außerhalb wissenschaftlicher Studien ist eine individuelle Kosten-Nutzen-Betrachtung durch den verantwortlichen Arzt geboten. Schlußfolgerungen: Die metabolische Bildgebung von PET besitzt für eine Vielzahl onkologischer Fragestellungen prinzipielle Vorteile gegenüber der anatomisch-morphologisch orientierten Schnittbilddiagnostik. Für die klinische Indikationsstellung ist allerdings eine differenzierte Betrachtung der spezifischen Leistungsfähigkeit von PET geboten.

CD133/CD166/Ki-67 Triple Immunouorescence Assessment for Putative Cancer Stem Cells in Colon Carcinoma*

2014 ◽  
Vol 23 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Claudiu Margaritescu ◽  
Daniel Pirici ◽  
Irina Cherciu ◽  
Alexandru Barbalan ◽  
Tatiana Cârtâna ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Stem Cells ◽  
Colon Cancer ◽  
Cancer Stem Cells ◽  
Colon Carcinoma ◽  
Sodium Dodecyl ◽  
High Grade Dysplasia ◽  
Early Event ◽  
Low Grade ◽  
High Grade

Background & Aims: Colorectal cancer represents the third most common malignancy and the fourth most common cause of cancer death worldwide. The existence of drug-resistant colon cancer stem cells is thought to be one of the most important reasons behind treatment failure in colon cancer, their existence putatively leading to metastasis and recurrences. The aim of our study was to investigate the immunoexpression patterns of CD133 and CD166 in colon carcinoma, both individually and in combination, assessing their significance as prognostic markers.Methods. A total of 45 retrospective colon adenocarcinoma cases were investigated by enzymatic and multiple fluorescence immunohistochemistry for their CD133 and CD166 expression and colocalization.Results. Both CD133 and CD166 were expressed to different extents in all cancer specimens, with apredominant cytoplasmic pattern for CD133 and a more obvious membranous-like pattern for CD166.Overall, when comparing their reactivity for the tumoral tissue, CD166 expression areas seemed to be smaller than those of CD133. However, there was a direct correlation between CD133 and CD166 expression levels throughout the entire spectrum of lesions, with higher values for dysplastic lesions. Colocalization of CD133/ CD166 was obvious at the level of cells membranes, with higher coeficients in high grade dysplasia, followed by well and moderate differentiated tumours.Conclusions. CD133/CD166 colocalization is an early event occurring in colon tumorigenesis, with thehighest coeficients recorded for patients with high grade dysplasia, followed by well differentiated tumours. Thus, we consider that the coexpression of these two markers could be useful for further prognostic andtherapeutically stratification of patients with colon cancer.Abbreviations: AJCC - American Joint Committee on Cancer; CCD - charge-coupled device camera sensor; CD133 - prominin-1 (PROM1); CD166 - Activated Leukocyte Cell Adhesion Molecule (ALCAM); CRC - colorectal cancer; CSC - cancer stem cells; DAB - 3,3'-diaminobenzidine chromogen; DAPI - 4',6-diamidino- 2-phenylindole; HE - Hematoxylin and eosin staining; HGD - high grade dysplasia; HRP - horseradish peroxidase; LGD - low grade dysplasia; SDS - sodium dodecyl sulfate*Part of this work has been accepted as a poster presentation at the Digestive Disease Week (DDW) meeting, Chicago, IL, USA May 3-6, 2014

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