Evaluation of alternate categorical tumor metrics and cut points for response categorization using the RECIST 1.1 data warehouse.

Science.gov (United States)

Mandrekar, Sumithra J; An, Ming-Wen; Meyers, Jeffrey; Grothey, Axel; Bogaerts, Jan; Sargent, Daniel J

2014-03-10

We sought to test and validate the predictive utility of trichotomous tumor response (TriTR; complete response [CR] or partial response [PR] v stable disease [SD] v progressive disease [PD]), disease control rate (DCR; CR/PR/SD v PD), and dichotomous tumor response (DiTR; CR/PR v others) metrics using alternate cut points for PR and PD. The data warehouse assembled to guide the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 was used. Data from 13 trials (5,480 patients with metastatic breast cancer, non-small-cell lung cancer, or colorectal cancer) were randomly split (60:40) into training and validation data sets. In all, 27 pairs of cut points for PR and PD were considered: PR (10% to 50% decrease by 5% increments) and PD (10% to 20% increase by 5% increments), for which 30% and 20% correspond to the RECIST categorization. Cox proportional hazards models with landmark analyses at 12 and 24 weeks stratified by study and number of lesions (fewer than three v three or more) and adjusted for average baseline tumor size were used to assess the impact of each metric on overall survival (OS). Model discrimination was assessed by using the concordance index (c-index). Standard RECIST cut points demonstrated predictive ability similar to the alternate PR and PD cut points. Regardless of tumor type, the TriTR, DiTR, and DCR metrics had similar predictive performance. The 24-week metrics (albeit with higher c-index point estimate) were not meaningfully better than the 12-week metrics. None of the metrics did particularly well for breast cancer. Alternative cut points to RECIST standards provided no meaningful improvement in OS prediction. Metrics assessed at 12 weeks have good predictive performance.

Optimum BMI cut points to screen asian americans for type 2 diabetes.

Science.gov (United States)

Araneta, Maria Rosario G; Kanaya, Alka M; Hsu, William C; Chang, Healani K; Grandinetti, Andrew; Boyko, Edward J; Hayashi, Tomoshige; Kahn, Steven E; Leonetti, Donna L; McNeely, Marguerite J; Onishi, Yukiko; Sato, Kyoko K; Fujimoto, Wilfred Y

2015-05-01

Asian Americans manifest type 2 diabetes at low BMI levels but may not undergo diagnostic testing for diabetes if the currently recommended BMI screening cut point of ≥25 kg/m(2) is followed. We aimed to ascertain an appropriate lower BMI cut point among Asian-American adults without a prior diabetes diagnosis. We consolidated data from 1,663 participants, ages ≥45 years, without a prior diabetes diagnosis, from population- and community-based studies, including the Mediators of Atherosclerosis in South Asians Living in America study, the North Kohala Study, the Seattle Japanese American Community Diabetes Study, and the University of California San Diego Filipino Health Study. Clinical measures included a 2-h 75-g oral glucose tolerance test, BMI, and glycosylated hemoglobin (HbA1c). Mean age was 59.7 years, mean BMI was 25.4 kg/m(2), 58% were women, and type 2 diabetes prevalence (American Diabetes Association 2010 criteria) was 16.9%. At BMI ≥25 kg/m(2), sensitivity (63.7%), specificity (52.8%), and Youden index (0.16) values were low; limiting screening to BMI ≥25 kg/m(2) would miss 36% of Asian Americans with type 2 diabetes. For screening purposes, higher sensitivity is desirable to minimize missing cases, especially if the diagnostic test is relatively simple and inexpensive. At BMI ≥23 kg/m(2), sensitivity (84.7%) was high in the total sample and by sex and Asian-American subgroup and would miss only ∼15% of Asian Americans with diabetes. The BMI cut point for identifying Asian Americans who should be screened for undiagnosed type 2 diabetes should be <25 kg/m(2), and ≥23 kg/m(2) may be the most practical. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Effect of the cut off frequency on rough point and flat surface contacts

International Nuclear Information System (INIS)

Meng, Fan Ming

2012-01-01

In the past years, contact between two bodies has been studied from various ways that do not consider the cut off frequency effect on the contact mechanism. This paper reports the correlation between rough point contact and flat surface contact at different cut off frequencies of filter. The similarity and difference between the two types of contact mechanisms are presented for materials with linear or elastic perfectly plastic deformation. The conjugate gradient method (CGM) is used for analysing the rough point contact, while the rough flat surface contact is studied with an improved CGM in which the influence coefficient for the elastic deformation of the rough flat surface is obtained with finite element method. Numerical results show that for the above two types of contacts, their von Mises stress and maximum shear stress are greatly affected by the cut-off frequency of a high pass filter. Moreover, a decrease in the cut-off frequency leads to an increase in the contact area and a decrease in the approach for the rough flat surface contact, while the opposite variations is for the point contact between rough bodies with the small radii

Screening for Internet Addiction: An Empirical Study on Cut-off Points for the Chen Internet Addiction Scale

Directory of Open Access Journals (Sweden)

Chih-Hung Ko

2005-12-01

Full Text Available The aim of this study was to establish the optimal cut-off points of the Chen Internet Addiction Scale (CIAS, to screen for and diagnose Internet addiction among adolescents in the community by using the well- established diagnostic criteria of Internet addiction. This survey of 454 adolescents used screening (57/58 and diagnostic (63/64 cut-off points of the CIAS, a self-reported instrument, based on the results of systematic diagnostic interviews by psychiatrists. The area under the curve of the receiver operating characteristic curve revealed that CIAS has good diagnostic accuracy (89.6%. The screening cut-off point had high sensitivity (85.6% and the diagnostic cut-off point had the highest diagnostic accuracy, classifying 87.6% of participants correctly. Accordingly, the screening point of the CIAS could provide a screening function in two-stage diagnosis, and the diagnostic point could serve as a diagnostic criterion in one-stage massive epidemiologic research.

Cutting-Edge Technologies and Social Media Use in Higher Education

Science.gov (United States)

Benson, Vladlena, Ed.; Morgan, Stephanie

2014-01-01

The inclusion of social media in higher education has transformed the way instructors teach and students learn. In order to effectively reach their students in this networked world, teachers must learn to utilize the latest technologies in their classrooms. "Cutting-Edge Technologies and Social Media Use in Higher Education" brings…

Detecting outliers and/or leverage points: a robust two-stage procedure with bootstrap cut-off points

Directory of Open Access Journals (Sweden)

Ettore Marubini

2014-01-01

Full Text Available This paper presents a robust two-stage procedure for identification of outlying observations in regression analysis. The exploratory stage identifies leverage points and vertical outliers through a robust distance estimator based on Minimum Covariance Determinant (MCD. After deletion of these points, the confirmatory stage carries out an Ordinary Least Squares (OLS analysis on the remaining subset of data and investigates the effect of adding back in the previously deleted observations. Cut-off points pertinent to different diagnostics are generated by bootstrapping and the cases are definitely labelled as good-leverage, bad-leverage, vertical outliers and typical cases. The procedure is applied to four examples.

Physical Activity Questionnaire for children and adolescents: English norms and cut-off points.

Science.gov (United States)

Voss, Christine; Ogunleye, Ayodele A; Sandercock, Gavin R H

2013-08-01

The Physical Activity Questionnaire for Children and Adolescents (PAQ-C/-A) provides general estimates of physical activity levels. Following recent expert recommendations for using the PAQ for population surveillance, the aim of this paper was twofold: first, to describe normative PAQ data for English youth; and second, to determine a criterion-referenced PAQ-score cut-off point. Participants (n = 7226, 53% boys, 10-15 years) completed an anglicized version of the PAQ. Peak oxygen uptake (VO2peak ) was predicted from PACER lap count according to latest FITNESSGRAM standards and categorized into "at-risk" and "no-risk" for metabolic syndrome. ROC curves were drawn for each age-sex group to identify PAQ scores, which categorized youth into "sufficiently active" versus "low-active" groups, using cardiorespiratory fitness as the criterion-referenced standard. PAQ scores were higher in boys than in girls and declined with age. Mean PAQ score was a significant, albeit relatively weak (area under the curve PAQ scores of ≥2.9 for boys and ≥2.7 for girls were identified as cut-off points, although it may be more appropriate to use lower, age-specific PAQ scores for girls of 13, 14 and 15 years (2.6, 2.4, 2.3, respectively). The normative and criterion-referenced PAQ values may be used to standardize and categorize PAQ scores in future youth population studies. © 2013 The Authors. Pediatrics International © 2013 Japan Pediatric Society.

Correlation between Body Mass Index, Gender, and Skeletal Muscle Mass Cut off Point in Bandung

OpenAIRE

Richi Hendrik Wattimena; Vitriana; Irma Ruslina Defi

2017-01-01

Objective: To determine the average skeletal muscle mass (SMM) value in young adults as a reference population; to analyze the correlation of gender, and body mass index to the cut off point; and to determine skeletal muscle mass cut off points of population in Bandung, Indonesia. Methods: This was a cross-sectional study involving 199 participants, 122 females and 77 males. The sampling technique used was the multistage random sampling. The participants were those who lived in four ma...

An ultra-precision tool nanoindentation instrument for replication of single point diamond tool cutting edges

Science.gov (United States)

Cai, Yindi; Chen, Yuan-Liu; Xu, Malu; Shimizu, Yuki; Ito, So; Matsukuma, Hiraku; Gao, Wei

2018-05-01

Precision replication of the diamond tool cutting edge is required for non-destructive tool metrology. This paper presents an ultra-precision tool nanoindentation instrument designed and constructed for replication of the cutting edge of a single point diamond tool onto a selected soft metal workpiece by precisely indenting the tool cutting edge into the workpiece surface. The instrument has the ability to control the indentation depth with a nanometric resolution, enabling the replication of tool cutting edges with high precision. The motion of the diamond tool along the indentation direction is controlled by the piezoelectric actuator of a fast tool servo (FTS). An integrated capacitive sensor of the FTS is employed to detect the displacement of the diamond tool. The soft metal workpiece is attached to an aluminum cantilever whose deflection is monitored by another capacitive sensor, referred to as an outside capacitive sensor. The indentation force and depth can be accurately evaluated from the diamond tool displacement, the cantilever deflection and the cantilever spring constant. Experiments were carried out by replicating the cutting edge of a single point diamond tool with a nose radius of 2.0 mm on a copper workpiece surface. The profile of the replicated tool cutting edge was measured using an atomic force microscope (AFM). The effectiveness of the instrument in precision replication of diamond tool cutting edges is well-verified by the experimental results.

Cut-Off Points for Mild, Moderate, and Severe Pain on the Numeric Rating Scale for Pain in Patients with Chronic Musculoskeletal Pain: Variability and Influence of Sex and Catastrophizing.

Science.gov (United States)

Boonstra, Anne M; Stewart, Roy E; Köke, Albère J A; Oosterwijk, René F A; Swaan, Jeannette L; Schreurs, Karlein M G; Schiphorst Preuper, Henrica R

2016-01-01

Objectives: The 0-10 Numeric Rating Scale (NRS) is often used in pain management. The aims of our study were to determine the cut-off points for mild, moderate, and severe pain in terms of pain-related interference with functioning in patients with chronic musculoskeletal pain, to measure the variability of the optimal cut-off points, and to determine the influence of patients' catastrophizing and their sex on these cut-off points. Methods: 2854 patients were included. Pain was assessed by the NRS, functioning by the Pain Disability Index (PDI) and catastrophizing by the Pain Catastrophizing Scale (PCS). Cut-off point schemes were tested using ANOVAs with and without using the PSC scores or sex as co-variates and with the interaction between CP scheme and PCS score and sex, respectively. The variability of the optimal cut-off point schemes was quantified using bootstrapping procedure. Results and conclusion: The study showed that NRS scores ≤ 5 correspond to mild, scores of 6-7 to moderate and scores ≥8 to severe pain in terms of pain-related interference with functioning. Bootstrapping analysis identified this optimal NRS cut-off point scheme in 90% of the bootstrapping samples. The interpretation of the NRS is independent of sex, but seems to depend on catastrophizing. In patients with high catastrophizing tendency, the optimal cut-off point scheme equals that for the total study sample, but in patients with a low catastrophizing tendency, NRS scores ≤ 3 correspond to mild, scores of 4-6 to moderate and scores ≥7 to severe pain in terms of interference with functioning. In these optimal cut-off schemes, NRS scores of 4 and 5 correspond to moderate interference with functioning for patients with low catastrophizing tendency and to mild interference for patients with high catastrophizing tendency. Theoretically one would therefore expect that among the patients with NRS scores 4 and 5 there would be a higher average PDI score for those with low

Waist circumference cut-off points for identification of abdominal obesity among the tunisian adult population.

Science.gov (United States)

Bouguerra, R; Alberti, H; Smida, H; Salem, L B; Rayana, C B; El Atti, J; Achour, A; Gaigi, S; Slama, C B; Zouari, B; Alberti, K G M M

2007-11-01

Waist circumference (WC) is a convenient measure of abdominal adipose tissue. It itself is a cardiovascular disease (CVD) and diabetes-risk factor and is strongly linked to other CVD risk factors. There are, however, ethnic differences in the relationship of WC to the other risk factors. The aim of this study was to determine the optimal cut-off points of WC and body mass index (BMI) at which cardiovascular risk factors can be identified with maximum sensitivity and specificity in a representative sample of the Tunisian adult population and to investigate any correlation between WC and BMI. We used a sample of the Tunisian National Nutrition Survey, a cross-sectional population-based survey, conducted in 1996 on a large nationally representative sample, which included 3435 adults (1244 men and 2191 women) of 20 years or older. WC, BMI, blood pressure and fasting blood measurements (plasma glucose, total cholesterol, triglycerides) were recorded. Receiver operating characteristic (ROC) curve analysis was used to identify optimal cut-off values of WC and BMI to identify with maximum sensitivity and specificity the detection of high blood pressure, hyperglycaemia, high blood cholesterol and hypertriglyceridaemia. ROC curve analysis suggested WC cut-off points of 85 cm in men and 85 cm in women for the optimum detection of high blood pressure, diabetes and dyslipidaemia. The optimum BMI cut-off points for predicting cardiovascular risk factors were 24 kg/m(2) in men and 27 kg/m(2) in women. The cut-off points recommended for the Caucasian population differ from those appropriate for the Tunisian population. The data show a continuous increase in odds ratios of each cardiovascular risk factor, with increasing level of WC and BMI. WC exceeding 85 cm in men and 79 cm in women correctly identified subjects with a BMI of >/=25 kg/m(2), sensitivity of >90% and specificity of >83%. Based on the ROC analysis, we suggest a WC of 85 cm for both men and women as appropriate cut

Comparison of cutting and pencil-point spinal needle in spinal anesthesia regarding postdural puncture headache

Science.gov (United States)

Xu, Hong; Liu, Yang; Song, WenYe; Kan, ShunLi; Liu, FeiFei; Zhang, Di; Ning, GuangZhi; Feng, ShiQing

2017-01-01

Abstract Background: Postdural puncture headache (PDPH), mainly resulting from the loss of cerebral spinal fluid (CSF), is a well-known iatrogenic complication of spinal anesthesia and diagnostic lumbar puncture. Spinal needles have been modified to minimize complications. Modifiable risk factors of PDPH mainly included needle size and needle shape. However, whether the incidence of PDPH is significantly different between cutting-point and pencil-point needles was controversial. Then we did a meta-analysis to assess the incidence of PDPH of cutting spinal needle and pencil-point spinal needle. Methods: We included all randomly designed trials, assessing the clinical outcomes in patients given elective spinal anesthesia or diagnostic lumbar puncture with either cutting or pencil-point spinal needle as eligible studies. All selected studies and the risk of bias of them were assessed by 2 investigators. Clinical outcomes including success rates, frequency of PDPH, reported severe PDPH, and the use of epidural blood patch (EBP) were recorded as primary results. Results were evaluated using risk ratio (RR) with 95% confidence interval (CI) for dichotomous variables. Rev Man software (version 5.3) was used to analyze all appropriate data. Results: Twenty-five randomized controlled trials (RCTs) were included in our study. The analysis result revealed that pencil-point spinal needle would result in lower rate of PDPH (RR 2.50; 95% CI [1.96, 3.19]; P < 0.00001) and severe PDPH (RR 3.27; 95% CI [2.15, 4.96]; P < 0.00001). Furthermore, EBP was less used in pencil-point spine needle group (RR 3.69; 95% CI [1.96, 6.95]; P < 0.0001). Conclusions: Current evidences suggest that pencil-point spinal needle was significantly superior compared with cutting spinal needle regarding the frequency of PDPH, PDPH severity, and the use of EBP. In view of this, we recommend the use of pencil-point spinal needle in spinal anesthesia and lumbar puncture. PMID:28383416

ELISA Cut-off Point for the Diagnosis of Human Brucellosis; a Comparison with Serum Agglutination Test

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Anahita Sanaei Dashti

2012-03-01

Full Text Available Background: Brucellosis is a world-wide disease, which has a diverse clinical manifestation, and its diagnosis has to be proven by laboratory data. Serum agglutination test (SAT is the most-widely used test for diagnosing brucellosis. The enzyme linked immunosorbent assay (ELISA can also determine specific antibody classes against brucella. It is a sensitive, simple and rapid test, which could be an acceptable alternative to SAT with fewer limitations, however, like any other new test it should be further evaluated and standardized for various populations. This study was planned to determine an optimal cut-off point, for ELISA which would offer maximum sensitivity and specificity for the test when compared to SAT.Methods: Four hundred and seven patients with fever and other compatible symptoms of brucellosis were enrolled in the study. Serum agglutination test, 2-Mercaptoethanol test, and ELISA were performed on their sera. Results: The cut-off point of 53 IU/ml of ELISA-IgG yielded the maximal sensitivity and specificity comparing to the other levels of ELISA-IgG, and was considered the best cut off-point of ELISA-IgG to diagnose acute brucellosis. At this cut-off, the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 84.09%, 85.38%, 62.20, 94.90, 5.75, 0.18, respectively.Conclusion: The best cut-off point of ELISA-IgG is 53 IU/ml, which yields the maximal sensitivity and specificity to diagnose acute brucellosis.

Intensity cut-points for the Respiratory Distress Observation Scale

Science.gov (United States)

Campbell, Margaret L; Templin, Thomas N

2015-01-01

Background The Respiratory Distress Observation Scale© is an innovative solution to assessment when a dyspnea report cannot be elicited. The Respiratory Distress Observation Scale has acceptable reliability and validity psychometrics. Aim To identify distress-intensity cut-points of the Respiratory Distress Observation Scale. Design Receiver operating characteristic curve analysis was conducted with inpatients stratified by four levels of respiratory distress—none, mild, moderate, or severe. Patients provided three self-report measures of dyspnea: dichotomous (yes/no); a ranking of none, mild, moderate, or severe; and a numerical rating scale. Respiratory distress was assessed using the Respiratory Distress Observation Scale instrument. Setting/participants Participants were 136 adult inpatients, mean age 61.8 years (standard deviation = 13.18 years), 89.7% African American, and 56.6% female, who were recruited from an urban, tertiary care hospital in the Midwest of the United States. Results In all, 47% (n = 64) self-reported dyspnea (yes/no). Ranking was distributed as follows: none = 36, mild = 35, moderate = 40, and severe = 25. Numerical rating scale scores ranged from 0 to 10, mean = 4.99 (standard deviation = 2.9). Respiratory Distress Observation Scale scores ranged from 0 to 7, median (interquartile range) = 2 (1–3). Receiver operating characteristic curve analysis–determined Respiratory Distress Observation Scale score of 0–2 suggests little or no respiratory distress; score ≥3 signified moderate to severe distress. Conclusion A Respiratory Distress Observation Scale score ≥3 signifies a patient’s need for palliation of respiratory distress. An end-point for identifying responsiveness to treatment, in other words, respiratory comfort, is Respiratory Distress Observation Scale <3. Because patients with imminent respiratory failure, as typified by dying patients, were not represented yielding lower than expected Respiratory Distress

Clinically Relevant Cut-off Points for the Diagnosis of Sarcopenia in Older Korean People.

Science.gov (United States)

Choe, Yu-Ri; Joh, Ju-Youn; Kim, Yeon-Pyo

2017-11-09

The optimal criteria applied to older Korean people have not been defined. We aimed to define clinically relevant cut-off points for older Korean people and to compare the predictive validity with other definitions of sarcopenia. Nine hundred and sixteen older Koreans (≥65 years) were included in this cross-sectional observational study. We used conditional inference tree analysis to determine cut-off points for height-adjusted grip strength (GS) and appendicular skeletal muscle mass (ASM), for use in the diagnosis of sarcopenia. We then compared the Korean sarcopenia criteria with the Foundation for the National Institutes of Health and Asian Working Group for Sarcopenia criteria, using frailty, assessed with the Korean Frailty Index, as an outcome variable. For men, a residual GS (GSre) of ≤ 0.25 was defined as weak, and a residual ASM (ASMre) of ≤ 1.29 was defined as low. Corresponding cut-off points for women were a GSre of ≤ 0.17 and an ASMre of ≤ 0.69. GSre and ASMre values were adjusted for height. In logistic regression analysis with new cut-off points, the adjusted odds ratios for pre-frail or frail status in the sarcopenia group were 3.23 (95% confidence interval [CI] 1.33-7.83) for the men and 1.74 (95% CI 0.91-3.35) for the women. In receiver operating characteristic curve analysis, the unadjusted area under the curve for Korean sarcopenia criteria in men and women were 0.653 and 0.608, respectively (p sarcopenia in older Korean people. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

On the Cut-off Point for Combinatorial Group Testing

DEFF Research Database (Denmark)

Fischer, Paul; Klasner, N.; Wegener, I.

1999-01-01

is answered by 1 if Q contains at least one essential object and by 0 otherwise. In the statistical setting the objects are essential, independently of each other, with a given probability p combinatorial setting the number k ... group testing is equal to p* = 12(3 - 5), i.e., the strategy of testing each object individually minimizes the average number of queries iff p >= p* or n = 1. In the combinatorial setting the worst case number of queries is of interest. It has been conjectured that the cut-off point of combinatorial...

Influence of Fiber Orientation on Single-Point Cutting Fracture Behavior of Carbon-Fiber/Epoxy Prepreg Sheets

OpenAIRE

Wei, Yingying; An, Qinglong; Cai, Xiaojiang; Chen, Ming; Ming, Weiwei

2015-01-01

The purpose of this article is to investigate the influences of carbon fibers on the fracture mechanism of carbon fibers both in macroscopic view and microscopic view by using single-point flying cutting method. Cutting tools with three different materials were used in this research, namely, PCD (polycrystalline diamond) tool, CVD (chemical vapor deposition) diamond thin film coated carbide tool and uncoated carbide tool. The influence of fiber orientation on the cutting force and fracture to...

Forces, surface finish and friction characteristics in surface engineered single- and multiple-point cutting edges

International Nuclear Information System (INIS)

Sarwar, M.; Gillibrand, D.; Bradbury, S.R.

1991-01-01

Advanced surface engineering technologies (physical and chemical vapour deposition) have been successfully applied to high speed steel and carbide cutting tools, and the potential benefits in terms of both performance and longer tool life, are now well established. Although major achievements have been reported by many manufacturers and users, there are a number of applications where surface engineering has been unsuccessful. Considerable attention has been given to the film characteristics and the variables associated with its properties; however, very little attention has been directed towards the benefits to the tool user. In order to apply surface engineering technology effectively to cutting tools, the coater needs to have accurate information relating to cutting conditions, i.e. cutting forces, stress and temperature etc. The present paper describes results obtained with single- and multiple-point cutting tools with examples of failures, which should help the surface coater to appreciate the significance of the cutting conditions, and in particular the magnitude of the forces and stresses present during cutting processes. These results will assist the development of a systems approach to cutting tool technology and surface engineering with a view to developing an improved product. (orig.)

Age-related differences in recommended anthropometric cut-off point validity to identify cardiovascular risk factors in ostensibly healthy women.

Science.gov (United States)

Subramoney, Sreevidya; Björkelund, Cecilia; Guo, Xinxin; Skoog, Ingmar; Bosaeus, Ingvar; Lissner, Lauren

2014-12-01

To investigate validity of widely recommended anthropometric and total fat percentage cut-off points in screening for cardiovascular risk factors in women of different ages. A population-based sample of 1002 Swedish women aged 38, 50, 75 (younger, middle-aged and elderly, respectively) underwent anthropometry, health examinations and blood tests. Total fat was estimated (bioimpedance) in 670 women. Sensitivity, specificity of body mass index (BMI; ≥25 and ≥30), waist circumference (WC; ≥80 cm and ≥88 cm) and total fat percentage (TF; ≥35%) cut-off points for cardiovascular risk factors (dyslipidaemias, hypertension and hyperglycaemia) were calculated for each age. Cut-off points yielding high sensitivity together with modest specificity were considered valid. Women reporting hospital admission for cardiovascular disease were excluded. The sensitivity of WC ≥80 cm for one or more risk factors was ~60% in younger and middle-aged women, and 80% in elderly women. The specificity of WC ≥80 cm for one or more risk factors was 69%, 57% and 40% at the three ages (p < .05 for age trends). WC ≥80 cm yielded ~80% sensitivity for two or more risk factors across all ages. However, specificity decreased with increasing age (p < .0001), being 33% in elderly. WC ≥88 cm provided better specificity in elderly women. BMI and TF % cut-off points were not better than WC. Validity of recommended anthropometric cut-off points in screening asymptomatic women varies with age. In younger and middle-age, WC ≥80 cm yielded high sensitivity and modest specificity for two or more risk factors, however, sensitivity for one or more risk factor was less than optimal. WC ≥88 cm showed better validity than WC ≥80 cm in elderly. Our results support age-specific screening cut-off points for women. © 2014 the Nordic Societies of Public Health.

Influence of Fiber Orientation on Single-Point Cutting Fracture Behavior of Carbon-Fiber/Epoxy Prepreg Sheets

Directory of Open Access Journals (Sweden)

Yingying Wei

2015-10-01

Full Text Available The purpose of this article is to investigate the influences of carbon fibers on the fracture mechanism of carbon fibers both in macroscopic view and microscopic view by using single-point flying cutting method. Cutting tools with three different materials were used in this research, namely, PCD (polycrystalline diamond tool, CVD (chemical vapor deposition diamond thin film coated carbide tool and uncoated carbide tool. The influence of fiber orientation on the cutting force and fracture topography were analyzed and conclusions were drawn that cutting forces are not affected by cutting speeds but significantly influenced by the fiber orientation. Cutting forces presented smaller values in the fiber orientation of 0/180° and 15/165° but the highest one in 30/150°. The fracture mechanism of carbon fibers was studied in different cutting conditions such as 0° orientation angle, 90° orientation angle, orientation angles along fiber direction, and orientation angles inverse to the fiber direction. In addition, a prediction model on the cutting defects of carbon fiber reinforced plastic was established based on acoustic emission (AE signals.

Influence of Fiber Orientation on Single-Point Cutting Fracture Behavior of Carbon-Fiber/Epoxy Prepreg Sheets.

Science.gov (United States)

Wei, Yingying; An, Qinglong; Cai, Xiaojiang; Chen, Ming; Ming, Weiwei

2015-10-02

The purpose of this article is to investigate the influences of carbon fibers on the fracture mechanism of carbon fibers both in macroscopic view and microscopic view by using single-point flying cutting method. Cutting tools with three different materials were used in this research, namely, PCD (polycrystalline diamond) tool, CVD (chemical vapor deposition) diamond thin film coated carbide tool and uncoated carbide tool. The influence of fiber orientation on the cutting force and fracture topography were analyzed and conclusions were drawn that cutting forces are not affected by cutting speeds but significantly influenced by the fiber orientation. Cutting forces presented smaller values in the fiber orientation of 0/180° and 15/165° but the highest one in 30/150°. The fracture mechanism of carbon fibers was studied in different cutting conditions such as 0° orientation angle, 90° orientation angle, orientation angles along fiber direction, and orientation angles inverse to the fiber direction. In addition, a prediction model on the cutting defects of carbon fiber reinforced plastic was established based on acoustic emission (AE) signals.

Association Between Aerobic Fitness And High Blood Pressure in Adolescents in Brazil: Evidence for Criterion-Referenced Cut-Points.

Science.gov (United States)

Silva, Diego Augusto; Tremblay, Mark; Pelegrini, Andreia; Dos Santos Silva, Roberto Jeronimo; Cabral de Oliveira, Antonio Cesar; Petroski, Edio Luiz

2016-05-01

Criterion-referenced cut-points for health-related fitness measures are lacking. This study aimed to determine the associations between aerobic fitness and high blood pressure levels (HBP) to determine the cut-points that best predict HBP among adolescents. This cross-sectional school-based study with sample of 875 adolescents aged 14-19 years was conducted in southern Brazil. Aerobic fitness was assessed using the modified Canadian Aerobic Fitness Test (mCAFT). Systolic and diastolic blood pressure were measured by the oscillometric method with a digital sphygmomanometer. Analyses controlled for sociodemographic variables, physical activity, body mass and biological maturation. Receiver Operating Characteristic (ROC) curves demonstrated that mCAFT measures could discriminate HBP in both sexes (female: AUC = 0.70; male: AUC = 0.63). The cut-points with the best discriminatory power for HBP were 32 mL·kg-1·min-1 for females and 40 mL·kg-1·min-1 for males. Females (OR = 8.4; 95% CI: 2.1, 33.7) and males (OR: 2.5; CI 95%: 1.2, 5.2) with low aerobic fitness levels were more likely to have HBP. mCAFT measures are inversely associated with BP and cut-points from ROC analyses have good discriminatory power for HBP.

Correlation between Body Mass Index, Gender, and Skeletal Muscle Mass Cut off Point in Bandung

Directory of Open Access Journals (Sweden)

Richi Hendrik Wattimena

2017-09-01

Full Text Available Objective: To determine the average skeletal muscle mass (SMM value in young adults as a reference population; to analyze the correlation of gender, and body mass index to the cut off point; and to determine skeletal muscle mass cut off points of population in Bandung, Indonesia. Methods: This was a cross-sectional study involving 199 participants, 122 females and 77 males. The sampling technique used was the multistage random sampling. The participants were those who lived in four major regions in Bandung, Indonesia: Sukajadi, Cicadas, Buah Batu, and Cibaduyut. Results: The average appendicular skeletal mass index (ASMI in females and males based on body mass index (BMI were identified. The average ASMI values for normal BMI in females was 5.982±0.462 kg/m2 while the average ASMI values normal BMI for males was 7.581±0.744 kg/m2 Conclusions: A correlation between BMI and ASMI that was considered statistically significant was found in females (0.7712; p<0.05 and a very significant correlation was seen in males (0.870; p<0.05. The cut off points were defined by the normal BMI, which were 5.059 for females and 6.093 for males.

Refining Game Addiction Questionnairs: Evidence for a natural cut-off point?

OpenAIRE

Nielsen, Rune Kristian

2013-01-01

This paper presents data from a pilot study, which was designed to illuminate critical flaws in the currently used instruments used to measure the prevalence of ‘computer game addiction’. The study found that the prevalence rate could be set anywhere between 23% and 0,6% depending on how the data set is scored. Thus demonstrating how an arbitrarily set of cut-off point in prevalence studies can yield wildly varying prevalence rates. The data further show that making implicit assumptions about...

The Potential of Established Fitness Cut-off Points for Monitoring Women with Fibromyalgia: The al-Ándalus Project.

Science.gov (United States)

Castro-Piñero, José; Aparicio, Virginia A; Estévez-López, Fernando; Álvarez-Gallardo, Inmaculada C; Borges-Cosic, Milkana; Soriano-Maldonado, Alberto; Delgado-Fernández, Manuel; Segura-Jiménez, Víctor

2017-05-01

The aim of the present study was to determinate whether fitness cut-off points discriminate the severity of major fibromyalgia symptoms and health-related quality of life. Additionally, we investigated which American Colleague of Rheumatology (ACR) fibromyalgia criteria (1990 vs. modified 2010) better discriminate fibromyalgia symptomatology. A total of 488 women with fibromyalgia and 200 non-fibromyalgia (control) women participated. All participants underwent both the 1990 and the modified 2010 ACR preliminary criteria (hereinafter 1990c and m-2010c, respectively). We used fitness cut-off points (Senior Fitness Tests Battery plus handgrip strength test) to discriminate between presence and absence of fibromyalgia. Additionally, we employed several instruments to assess fibromyalgia symptoms. Fitness cut-off points discriminated between high and low levels of the main symptoms the disease in all age groups (P from fibromyalgia diagnosis and monitoring. Moreover, the effect size of the differences in symptoms between women with fibromyalgia and controls were overall larger using the m-2010c compared with the 1990c, except for the tender points count, reflecting better the polysymptomatic distress condition of fibromyalgia. © Georg Thieme Verlag KG Stuttgart · New York.

Cut points for identifying clinically significant diabetes distress in adolescents with type 1 diabetes using the PAID-T

DEFF Research Database (Denmark)

Hagger, Virginia; Hendrieckx, Christel; Cameron, Fergus

2017-01-01

OBJECTIVE To establish cut point(s) for the Problem Areas in Diabetes-teen version (PAID-T) scale to identify adolescents with clinically meaningful, elevated diabetes distress. RESEARCH DESIGN AND METHODS Data were available from the Diabetes Management and Impact for Long-term Empowerment...... variables were examined to identify a clinically meaningful threshold for elevated diabetes distress. ANOVA was used to test whether these variables differed by levels of distress. RESULTS Two cut points distinguished none-to-mild (90) diabetes distress.......Moderate distresswas experienced by 18%of adolescents and high distress by 36%. Mean depressive symptoms, self-reported HbA1c, and SMBG differed significantly across the three levels of diabetes distress (all P defined two...

Five-axis Control Processing Using NC Machine Tools : A Tool Posture Decision Using the Tangent Slope at a Cut Point on a Work

OpenAIRE

小島, 龍広; 西田, 知照; 扇谷, 保彦

2003-01-01

This report deals with the way to decide tool posture and the way to analytically calculate tool path for the work shape requiring 5-axis control machining. In the tool path calculation, basic equations are derived using the principle that the tangent slope at a cut point on a work and the one at a cutting point on a tool edge are identical. A tool posture decision procedure using the tangent slope at each cut point on a work is proposed for any shape of tool edge. The valid- ity of the way t...

Filter for underground mining for suction of preferably full cut and part cut machines, to be provided with preheated air, to avoid dropping below the dew point

Energy Technology Data Exchange (ETDEWEB)

Hoelter, H.

1976-10-28

Particularly when cutting hard rock, the cutting room to be provided with suction is wetted with water from nozzles, which, when sucking out air containing dust with high humidity leads to encrustation in the filter cloth. In order to avoid this, it is proposed that the air should be heated, using heat from the motor driving the ventilator, so that one avoids dropping below the dew point in the filter.

Defining Glaucomatous Optic Neuropathy from a Continuous Measure of Optic Nerve Damage - The Optimal Cut-off Point for Risk-factor Analysis in Population-based Epidemiology

NARCIS (Netherlands)

Ramdas, Wishal D.; Rizopoulos, Dimitris; Wolfs, Roger C. W.; Hofman, Albert; de Jong, Paulus T. V. M.; Vingerling, Johannes R.; Jansonius, Nomdo M.

2011-01-01

Purpose: Diseases characterized by a continuous trait can be defined by setting a cut-off point for the disease measure in question, accepting some misclassification. The 97.5th percentile is commonly used as a cut-off point. However, it is unclear whether this percentile is the optimal cut-off

Effects of Varying Epoch Lengths, Wear Time Algorithms, and Activity Cut-Points on Estimates of Child Sedentary Behavior and Physical Activity from Accelerometer Data.

Science.gov (United States)

Banda, Jorge A; Haydel, K Farish; Davila, Tania; Desai, Manisha; Bryson, Susan; Haskell, William L; Matheson, Donna; Robinson, Thomas N

2016-01-01

To examine the effects of accelerometer epoch lengths, wear time (WT) algorithms, and activity cut-points on estimates of WT, sedentary behavior (SB), and physical activity (PA). 268 7-11 year-olds with BMI ≥ 85th percentile for age and sex wore accelerometers on their right hips for 4-7 days. Data were processed and analyzed at epoch lengths of 1-, 5-, 10-, 15-, 30-, and 60-seconds. For each epoch length, WT minutes/day was determined using three common WT algorithms, and minutes/day and percent time spent in SB, light (LPA), moderate (MPA), and vigorous (VPA) PA were determined using five common activity cut-points. ANOVA tested differences in WT, SB, LPA, MPA, VPA, and MVPA when using the different epoch lengths, WT algorithms, and activity cut-points. WT minutes/day varied significantly by epoch length when using the NHANES WT algorithm (p algorithms. Minutes/day and percent time spent in SB, LPA, MPA, VPA, and MVPA varied significantly by epoch length for all sets of activity cut-points tested with all three WT algorithms (all p algorithms (all p algorithms and activity cut-point definitions to match different epoch lengths may introduce significant errors. Estimates of SB and PA from studies that process and analyze data using different epoch lengths, WT algorithms, and/or activity cut-points are not comparable, potentially leading to very different results, interpretations, and conclusions, misleading research and public policy.

Raised BMI cut-off for overweight in Greenland Inuit--a review.

Science.gov (United States)

Andersen, Stig; Fleischer Rex, Karsten; Noahsen, Paneeraq; Sørensen, Hans Christian Florian; Mulvad, Gert; Laurberg, Peter

2013-01-01

Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI), a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population. This led us to reconsider the cut-off point for overweight among Inuit in Greenland. We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time. Defining overweight according to the WHO cut-off of a BMI above 25 kg/m(2) in Greenland Inuit may overestimate the number of individuals with elevated BMI.

Higher-order corrections in the cut vertex theory and the reciprocity relation in (PHI3)6 field theory

International Nuclear Information System (INIS)

Kubota, T.

1980-01-01

Higher-order corrections to deep inelastic and inclusive annihilation processes in the asymptotically free (PHI 3 ) 6 theory are calculated by using the method of cut vertices proposed by Mueller. Renormalization of the cut vertices is carried out up the two-loop level and it is found that, in the minimal subtraction scheme, the equality between the anomalous dimension of the space-like cut vertex and that of the corresponding time-like cut vertex does not hold beyond the leading order. Corrections to the coefficient functions are also calculated to study the Q 2 dependence of the moment up to the next-to-leading order. It is shown that the reciprocity relation suggested by Gribov and Lipatov on the basis of the leading-order calculation does not hold in the higher order. (orig.)

An Evaluation of the Cutting Potential of Different Types of High Power Lasers

DEFF Research Database (Denmark)

Olsen, Flemming Ove

2006-01-01

Laser cutting is a widespread industrial process. The boundaries for the performance of the lasers in terms of cutting capabilities is steadily moving towards higher cutting rates and thicker section cutting. In this paper the potential of different high power laser sources in cutting is evaluated...... based upon the historical development, the available cutting mechanisms understanding and the critical parameters involved in high power laser cutting. From the theoretical point of view, the new laser sources, the Disc-laser and the Fibre laser possess a potential of changing dramatically the limits...... for cutting performance. These theoretical considerations are evaluated against available cutting data....

Chip science: Basic study of the single-point cutting process

International Nuclear Information System (INIS)

Donaldson, R.R.; Riddle, R.A.; Syn, C.K.; Taylor, J.S.

1986-01-01

Wear that diamond tools sustain during the cutting of electroless nickel (eNi) has been measured. Wear was detected at previously unattained levels, down to 100 A, and it was found that the tool wear resulted in a burnishing action after a relatively short cutting distance. To provide a more direct connection between computer-based modeling and experimental measurements, macroscopic cutting tests on a well-characterized aluminum material were also performed. The results showed good agreement between calculated and measured cutting forces

Evaluation of an Optimal Cut-Off Point for the Ki-67 Index as a Prognostic Factor in Primary Breast Cancer: A Retrospective Study.

Directory of Open Access Journals (Sweden)

Rumiko Tashima

Full Text Available The Ki-67 index is an important biomarker for indicating the proliferation of cancer cells and is considered to be an effective prognostic factor for breast cancer. However, a standard cut-off point for the Ki-67 index has not yet been established. Therefore, the aim of this retrospective study was to determine an optimal cut-off point in order to establish it as a more accurate prognostic factor. Immunohistochemical analysis of the Ki-67 index was performed on 4329 patients with primary breast cancer from August 1987 to March 2012. Out of this sample, there were 3186 consecutive cases from September 1997 with simultaneous evaluations of ER, PgR and HER2 status. Cox's proportional hazard model was used to perform univariate and multivariate analyses of the factors related to OS. The hazard ratios (HR and the p values were then compared to determine the optimal cut-off point for the Ki-67 index. The median Ki-67 index value was 20.5% (mean value 26.2%. The univariate analysis revealed that there was a statistically significant negative correlation with DFS and OS and the multivariate analysis revealed that the Ki-67 index value was a significant factor for DFS and OS. The top seven cut-off points were then carefully chosen based on the results of the univariate analysis using the lowest p-values and the highest HR as the main selection criteria. The multivariate analysis of the factors for OS showed that the cut-off point of 20% had the highest HR in all of the cases. However, the cutoff point of 20% was only a significant factor for OS in the Luminal/HER2- subtype. There was no correlation between the Ki-67 index value and OS in any of the other subtypes. These data indicate that the optimal cut-off point of 20% is the most effective prognostic factor for Luminal/HER2- breast cancer.

Development of underwater laser cutting technology

International Nuclear Information System (INIS)

Sato, Seiichi; Inaba, Takanori; Inose, Koutarou; Matsumoto, Naoyuki; Sakakibara, Yuji

2015-01-01

In is desirable to use remote underwater device for the decommissioning work of highly radioactive components such as the nuclear internals from a view point of reducing the ranitidine exposure to the worker. Underwater laser cutting technology has advantages. First advantage in underwater laser cutting technology is that low reaction force during cutting, namely, remote operability is superior. Second point is that underwater laser cutting generates a little amount of secondary waste, because cutting kerf size is very small. Third point is that underwater laser cutting has low risk of the process delay, because device trouble is hard to happen. While underwater laser cutting has many advantages, the careful consideration in the safe treatment of the offgas which underwater laser cutting generates is necessary. This paper describes outline of underwater laser cutting technology developed by IHI Corporation (IHI) and that this technology is effective in various dismantling works in water. (author)

Adiposity cut-off points for cardiovascular disease and diabetes risk in the Portuguese population: The PORMETS study

Science.gov (United States)

Severo, Milton; Santos, Ana Cristina

2018-01-01

Objectives The contribution of adiposity to cardiovascular and diabetes risk justifies the inclusion of an adiposity measure, usually waist circumference, in the definition of metabolic syndrome. However, waist circumference thresholds differ across populations. Our aim was to assess which adiposity measure performs the best in identifying the metabolic syndrome in a sample of Portuguese participants and to estimate cut-off values for these measures. Methods Data were obtained from a cross-sectional study (PORMETS study) conducted in Portugal between 2007 and 2009. A representative sample of non-institutionalized adults, comprising 3,956 participants, aged 18 years and older, was evaluated. A structured questionnaire was administered, collecting information on personal medical history, socio-demographics and behavioral characteristics. Anthropometrics, blood pressure and venous blood samples were also obtained. Metabolic syndrome was defined according to the Joint Interim Statement of the International Diabetes Federation Task Force on Epidemiology recommended criteria. Elevated cardiometabolic risk was considered when two or more of the four criteria of metabolic syndrome were present, excluding the waist circumference component. A receiver operating characteristic curve was used to estimate cut-off points. Results This study found that waist-to-height ratio, waist circumference and body adiposity index performed better than other adiposity measures, such as body mass index. The estimated cut-off points for waist-to-height ratio, waist circumference and body adiposity index in women and men were 0.564 / 89 cm / 27.4 and 0.571 / 93.5 cm / 25.5, respectively. Conclusion As waist circumference is currently used as the adiposity measure in the definition of metabolic syndrome and as no relevant differences were observed between this measure and waist-to-height ratio, it is likely that no modification to the metabolic syndrome definition needs to be proposed. Moreover

Raised BMI cut-off for overweight in Greenland Inuit – a review

Science.gov (United States)

Andersen, Stig; Fleischer Rex, Karsten; Noahsen, Paneeraq; Sørensen, Hans Christian Florian; Mulvad, Gert; Laurberg, Peter

2013-01-01

Background Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI), a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population. Objective This led us to reconsider the cut-off point for overweight among Inuit in Greenland. Design and findings We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time. Conclusion Defining overweight according to the WHO cut-off of a BMI above 25 kg/m2 in Greenland Inuit may overestimate the number of individuals with elevated BMI. PMID:23986904

Raised BMI cut-off for overweight in Greenland Inuit – a review

Directory of Open Access Journals (Sweden)

Stig Andersen

2013-08-01

Full Text Available Background. Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI, a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population. Objective. This led us to reconsider the cut-off point for overweight among Inuit in Greenland. Design and findings. We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time. Conclusion. Defining overweight according to the WHO cut-off of a BMI above 25 kg/m2 in Greenland Inuit may overestimate the number of individuals with elevated BMI.

Combinations of Epoch Durations and Cut-Points to Estimate Sedentary Time and Physical Activity among Adolescents

Science.gov (United States)

Fröberg, Andreas; Berg, Christina; Larsson, Christel; Boldemann, Cecilia; Raustorp, Anders

2017-01-01

The purpose of the current study was to investigate how combinations of different epoch durations and cut-points affect the estimations of sedentary time and physical activity in adolescents. Accelerometer data from 101 adolescents were derived and 30 combinations were used to estimate sedentary time, light, moderate, vigorous, and combined…

An optimal cut-off point for the calving interval may be used as an indicator of bovine abortions.

Science.gov (United States)

Bronner, Anne; Morignat, Eric; Gay, Emilie; Calavas, Didier

2015-10-01

The bovine abortion surveillance system in France aims to detect as early as possible any resurgence of bovine brucellosis, a disease of which the country has been declared free since 2005. It relies on the mandatory notification and testing of each aborting cow, but under-reporting is high. This research uses a new and simple approach which considers the calving interval (CI) as a "diagnostic test" to determine optimal cut-off point c and estimate diagnostic performance of the CI to identify aborting cows, and herds with multiple abortions (i.e. three or more aborting cows per calving season). The period between two artificial inseminations (AI) was considered as a "gold standard". During the 2006-2010 calving seasons, the mean optimal CI cut-off point for identifying aborting cows was 691 days for dairy cows and 703 days for beef cows. Depending on the calving season, production type and scale at which c was computed (individual or herd), the average sensitivity of the CI varied from 42.6% to 64.4%; its average specificity from 96.7% to 99.7%; its average positive predictive value from 27.6% to 65.4%; and its average negative predictive value from 98.7% to 99.8%. When applied to the French bovine population as a whole, this indicator identified 2-3% of cows suspected to have aborted, and 10-15% of herds suspected of multiple abortions. The optimal cut-off point and CI performance were consistent over calving seasons. By applying an optimal CI cut-off point to the cattle demographics database, it becomes possible to identify herds with multiple abortions, carry out retrospective investigations to find the cause of these abortions and monitor a posteriori compliance of farmers with their obligation to report abortions for brucellosis surveillance needs. Therefore, the CI could be used as an indicator of abortions to help improve the current mandatory notification surveillance system. Copyright © 2015 Elsevier B.V. All rights reserved.

The effects of cutting parameters on cutting forces and heat generation when drilling animal bone and biomechanical test materials.

Science.gov (United States)

Cseke, Akos; Heinemann, Robert

2018-01-01

The research presented in this paper investigated the effects of spindle speed and feed rate on the resultant cutting forces (thrust force and torque) and temperatures while drilling SawBones ® biomechanical test materials and cadaveric cortical bone (bovine and porcine femur) specimens. It also investigated cortical bone anisotropy on the cutting forces, when drilling in axial and radial directions. The cutting forces are only affected by the feed rate, whereas the cutting temperature in contrast is affected by both spindle speed and feed rate. The temperature distribution indicates friction as the primary heat source, which is caused by the rubbing of the tool margins and the already cut chips over the borehole wall. Cutting forces were considerably higher when drilling animal cortical bone, in comparison to cortical test material. Drilling direction, and therewith anisotropy, appears to have a negligible effect on the cutting forces. The results suggest that this can be attributed to the osteons being cut at an angle rather than in purely axial or radial direction, as a result of a twist drill's point angle. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Practical side of cutting. Part 3. ; CO2 laser cutting. Setsudan gijutsu no jissai. 3. ; Laser setsudan

Energy Technology Data Exchange (ETDEWEB)

Miyazaki, T.; Shinonaga, H. (Toshiba Corp., Tokyo (Japan))

1993-03-05

The nature peculiar to laser beam makes it difficult to understand the phenomena in laser cutting. Quoting an example of cutting steel materials, practical minimum basic subjects, factors governing the cutting phenomena with points to be considered, and the current state of the technology are outlined. Various kinds of expert systems and automatic programming devices have been placed on the market to make NC input easier in laser cutting. Shape accuracy, cutting quality, cutting speed, applicable plate thickness, etc. are among the subjects required for laser cutting. The factors are the method of scanning, characteristics of laser beam, work, machining conditions, etc. The factors obstructing stable processing are the change in the ambient temperature, humidity, dust, oil mist, vibration, etc. The basic factors which control the laser cutting are the power density and its distribution at the working point. Pulse cutting is employed when continuous laser heat input is not appropriate. Summarized report is made on the focal point and assist gas. 16 refs., 9 figs., 1 tab.

Recessions and Tax-Cuts: Economic Cycles' Impact on Individual Giving, Philanthropy, and Higher Education

Science.gov (United States)

Drezner, Noah D.

2006-01-01

Few researchers have examined how individual giving to higher education is effected by the economy, specifically during downturns and periodic changes in tax laws. Further understanding the relationship between the economy's cycles and philanthropic giving, including the correlation of tax cuts to donations, will help colleges and universities…

Structural vascular disease in Africans: performance of ethnic-specific waist circumference cut points using logistic regression and neural network analyses: the SABPA study

OpenAIRE

Botha, J.; De Ridder, J.H.; Potgieter, J.C.; Steyn, H.S.; Malan, L.

2013-01-01

A recently proposed model for waist circumference cut points (RPWC), driven by increased blood pressure, was demonstrated in an African population. We therefore aimed to validate the RPWC by comparing the RPWC and the Joint Statement Consensus (JSC) models via Logistic Regression (LR) and Neural Networks (NN) analyses. Urban African gender groups (N=171) were stratified according to the JSC and RPWC cut point models. Ultrasound carotid intima media thickness (CIMT), blood pressure (BP) and fa...

Study of Cutting Edge Temperature and Cutting Force of End Mill Tool in High Speed Machining

Directory of Open Access Journals (Sweden)

Kiprawi Mohammad Ashaari

2017-01-01

Full Text Available A wear of cutting tools during machining process is unavoidable due to the presence of frictional forces during removing process of unwanted material of workpiece. It is unavoidable but can be controlled at slower rate if the cutting speed is fixed at certain point in order to achieve optimum cutting conditions. The wear of cutting tools is closely related with the thermal deformations that occurred between the frictional contact point of cutting edge of cutting tool and workpiece. This research paper is focused on determinations of relationship among cutting temperature, cutting speed, cutting forces and radial depth of cutting parameters. The cutting temperature is determined by using the Indium Arsenide (InAs and Indium Antimonide (InSb photocells to measure infrared radiation that are emitted from cutting tools and cutting forces is determined by using dynamometer. The high speed machining process is done by end milling the outer surface of carbon steel. The signal from the photocell is digitally visualized in the digital oscilloscope. Based on the results, the cutting temperature increased as the radial depth and cutting speed increased. The cutting forces increased when radial depth increased but decreased when cutting speed is increased. The setup for calibration and discussion of the experiment will be explained in this paper.

Flexible Laser Metal Cutting

DEFF Research Database (Denmark)

Villumsen, Sigurd; Jørgensen, Steffen Nordahl; Kristiansen, Morten

2014-01-01

This paper describes a new flexible and fast approach to laser cutting called ROBOCUT. Combined with CAD/CAM technology, laser cutting of metal provides the flexibility to perform one-of-a-kind cutting and hereby realises mass production of customised products. Today’s laser cutting techniques...... possess, despite their wide use in industry, limitations regarding speed and geometry. Research trends point towards remote laser cutting techniques which can improve speed and geometrical freedom and hereby the competitiveness of laser cutting compared to fixed-tool-based cutting technology...... such as punching. This paper presents the concepts and preliminary test results of the ROBOCUT laser cutting technology, a technology which potentially can revolutionise laser cutting....

A cut locus for finite graphs and the farthest point mapping

DEFF Research Database (Denmark)

Maddaloni, Alessandro; Zamfirescu, Carol T.

2016-01-01

We reflect upon an analogue of the cut locus, a notion classically studied in Differential Geometry, for finite graphs. The cut locus C(x) of a vertex x shall be the graph induced by the set of all vertices y with the property that no shortest path between x and z, z≠y, contains y. The cut locus ...

Cutting assembly

Science.gov (United States)

Racki, Daniel J.; Swenson, Clark E.; Bencloski, William A.; Wineman, Arthur L.

1984-01-01

A cutting apparatus includes a support table mounted for movement toward and away from a workpiece and carrying a mirror which directs a cutting laser beam onto the workpiece. A carrier is rotatably and pivotally mounted on the support table between the mirror and workpiece and supports a conduit discharging gas toward the point of impingement of the laser beam on the workpiece. Means are provided for rotating the carrier relative to the support table to place the gas discharging conduit in the proper positions for cuts made in different directions on the workpiece.

Refining Game Addiction Questionnairs: Evidence for a natural cut-off point?

DEFF Research Database (Denmark)

Nielsen, Rune Kristian

2013-01-01

This paper presents data from a pilot study, which was designed to illuminate critical flaws in the currently used instruments used to measure the prevalence of ‘computer game addiction’. The study found that the prevalence rate could be set anywhere between 23% and 0,6% depending on how the data...... is unique in the field of prevalence studies of computer game addiction both in its design and its findings. The findings and conclusions need to be addressed by future research in the area.......’ from ‘addicted gamers’ by making implicit assumptions about negative effects explicit will cause prevalence rates to drop even further. Unexpectedly, the data from this modified questionnaire provides preliminary evidence for a natural cut-off point that clearly separates addicted play from normal play...

The cut-off point of dual energy X-ray and laser of calcaneus osteoporosis diagnosis in postmenopausal women

International Nuclear Information System (INIS)

Salimzadeh, A.; Forough, B.; Olia, B.; Alishiri, G. H.; Ghasemzadeh, A.

2005-01-01

Dual X-Ray Absorptiometry is a method which can extensively be used for bone mineral densitometry . Another more recent method is dual energy X-ray and laser, which associate with dual X ray absorptiometry, assisted by laser measure heel thickness. In this study the cut off points for dual energy X-ray and laser of calcaneus in the diagnosis of osteoporosis in different bone regions in postmenopausal women had been determined. Materials and Methods: In 268 postmenopausal women, BMD of the spinal and femoral regions was measured by DM, and the value for the calcaneous was measured by dual energy X-ray and laser. The agreement of the two methods in the diagnosis of osteoporosis and optimal cut-off point for dual energy X-ray and laser in defining osteoporosis was obtained. What obtained was the agreement of the two methods in the diagnosis of osteoporosis, as well as the optimal cut-off point for dual energy X-ray and laser in defining osteoporosis. Results: Dual X-Ray Absorptiometry showed osteoporosis in 40.7% of cases with 35.2% in L2-L4, 16.2% in the femoral neck, and 11.7% for the femoral total region. The dual energy X-ray and laser found osteoporosis, considering -2.5 SD as a threshold, in 26.1% of cases. Agreement of the two methods in the diagnosis of osteoporosis (Kappa score) was 0.443 for the lumbar region, 0.464 for the neck, and, 0.421 for total femur regions (all P values were significant). Using Receiver Operating Characteristic curves, it was found that a T-score of -2.1, -2.6 and -2.4 as the optimal cut-off point of dual energy X-ray and laser in the diagnosis of osteoporosis in the lumbar spine, the neck and total region of femur, respectively. Conclusion: The results of this study showed a moderate agreement between the two methods in the diagnosis of osteoporosis. It seems that the dual energy X-ray and laser cannot be used as a substitute for the DM method, but it can be used as a screening method to find (to diagnose) osteoporosis

A cautionary note about the cross-national and clinical validity of cut-off points for the Maslach Burnout Inventory.

Science.gov (United States)

Schaufeli, W B; Van Dierendonck, D

1995-06-01

In the present study, burnout scores of three samples, as measured with the Maslach Burnout Inventory, were compared: (1) the normative American sample from the test-manual (N = 10,067), (2) the normative Dutch sample (N = 3,892), and (3) a Dutch outpatient sample (N = 142). Generally, the highest burnout scores were found for the outpatient sample, followed by the American and Dutch normative samples, respectively. Slightly different patterns were noted for each of the three components. Probably sampling bias, i.e., the healthy worker effect, or cultural value patterns, i.e., femininity versus masculinity, might be responsible for the results. It is concluded that extreme caution is required when cut-off points are used to classify individuals by burnout scores; only nation-specific and clinically derived cut-off points should be employed.

The Potential of Established Fitness Cut-off Points for Monitoring Women with Fibromyalgia : The al-Ándalus Project

NARCIS (Netherlands)

Castro-Piñero, José; Aparicio, Virginia A; Estévez-López, Fernando; Álvarez-Gallardo, Inmaculada C; Borges-Cosic, Milkana; Soriano-Maldonado, Alberto; Delgado-Fernández, Manuel; Segura-Jiménez, Víctor

2017-01-01

The aim of the present study was to determinate whether fitness cut-off points discriminate the severity of major fibromyalgia symptoms and health-related quality of life. Additionally, we investigated which American Colleague of Rheumatology (ACR) fibromyalgia criteria (1990 vs. modified 2010)

Higher genus correlators for the hermitian matrix model with multiple cuts

International Nuclear Information System (INIS)

Akemann, G.

1996-01-01

An iterative scheme is set up for solving the loop equation of the hermitian one-matrix model with a multi-cut structure. Explicit results are presented for genus one for an arbitrary but finite number of cuts. Due to the complicated form of the boundary conditions, the loop correlators now contain elliptic integrals. This demonstrates the existence of new universality classes for the hermitian matrix model. The two-cut solution is investigated in more detail, including the double scaling limit. It is shown that in special cases it differs from the known continuum solution with one cut. (orig.)

Receiver Operating Characteristic (ROC to Determine Cut-Off Points of Biomarkers in Lung Cancer Patients

Directory of Open Access Journals (Sweden)

Heidi L. Weiss

2004-01-01

Full Text Available The role of biomarkers in disease prognosis continues to be an important investigation in many cancer studies. In order for these biomarkers to have practical application in clinical decision making regarding patient treatment and follow-up, it is common to dichotomize patients into those with low vs. high expression levels. In this study, receiver operating characteristic (ROC curves, area under the curve (AUC of the ROC, sensitivity, specificity, as well as likelihood ratios were calculated to determine levels of growth factor biomarkers that best differentiate lung cancer cases versus control subjects. Selected cut-off points for p185erbB-2 and EGFR membrane appear to have good discriminating power to differentiate control tissues versus uninvolved tissues from patients with lung cancer (AUC = 89% and 90%, respectively; while AUC increased to at least 90% for selected cut-off points for p185erbB-2 membrane, EGFR membrane, and FASE when comparing between control versus carcinoma tissues from lung cancer cases. Using data from control subjects compared to patients with lung cancer, we presented a simple and intuitive approach to determine dichotomized levels of biomarkers and validated the value of these biomarkers as surrogate endpoints for cancer outcome.

SurfCut: Free-Boundary Surface Extraction

KAUST Repository

Algarni, Marei Saeed Mohammed

2016-09-15

We present SurfCut, an algorithm for extracting a smooth simple surface with unknown boundary from a noisy 3D image and a seed point. In contrast to existing approaches that extract smooth simple surfaces with boundary, our method requires less user input, i.e., a seed point, rather than a 3D boundary curve. Our method is built on the novel observation that certain ridge curves of a front propagated using the Fast Marching algorithm are likely to lie on the surface. Using the framework of cubical complexes, we design a novel algorithm to robustly extract such ridge curves and form the surface of interest. Our algorithm automatically cuts these ridge curves to form the surface boundary, and then extracts the surface. Experiments show the robustness of our method to errors in the data, and that we achieve higher accuracy with lower computational cost than comparable methods. © Springer International Publishing AG 2016.

Plasma arc cutting: speed and cut quality

International Nuclear Information System (INIS)

Nemchinsky, V A; Severance, W S

2009-01-01

When cutting metal with plasma arc cutting, the walls of the cut are narrower at the bottom than at the top. This lack of squareness increases as the cutting speed increases. A model of this phenomenon, affecting cut quality, is suggested. A thin liquid layer, which separates the plasma from the solid metal to be melted, plays a key role in the suggested model. This layer decreases heat transfer from the plasma to the solid metal; the decrease is more pronounced the higher the speed and the thicker the liquid metal layer. Since the layer is thicker at the bottom of the cut, the heat transfer effectiveness is lower at the bottom. The decrease in heat transfer effectiveness is compensated by the narrowness of the cut. The suggested model allows one to calculate the profile of the cut. The result of the calculations of the cutting speeds for plates of various thicknesses, at which the squareness of the cut is acceptable, agrees well with the speeds recommended by manufacturers. The second effect considered in the paper is the deflection of the plasma jet from the vertical at a high cutting speed. A qualitative explanation of this phenomenon is given. We believe the considerations of this paper are pertinent to other types of cutting with moving heat sources.

Night-time heart rate cut-off point definition by resting office tachycardia in untreated hypertensive patients: data of the Spanish ABPM registry.

Science.gov (United States)

Vinyoles, Ernest; de la Sierra, Alejandro; Roso, Albert; de la Cruz, Juan J; Gorostidi, Manuel; Segura, Julián; Banegas, José R; Martell-Claros, Nieves; Ruilope, Luís M

2014-05-01

Epidemiological studies have shown that an elevated resting heart rate (HR) is a risk factor for both total and cardiovascular mortality. Our aim was to estimate the night-time HR cut-off point that best predicts cardiovascular risk office tachycardia in hypertensive patients. Untreated hypertensive patients without concomitant cardiovascular diseases were included. Office and ambulatory HRs were measured. Cardiovascular risk office tachycardia was defined by office HR at least 85 beats per minute (bpm). Different night-time HR cut-offs were estimated by receiver operating characteristic curve analyses to predict cardiovascular risk office tachycardia. The best cut-off was selected on the basis of its combined sensitivity and specificity. A total of 32 569 hypertensive patients were included: 46.5% women, mean age (SD) 52 (14) years, office blood pressure 146 (16)/89 (11) mmHg, diabetes 10.3%, smoking 19.2%, BMI 29 (6.8) kg/m, office HR 77 (11.2) bpm, and night-time HR 64.9 (9.3) bpm. A total of 7070 (21.7%) patients were found to have cardiovascular risk office tachycardia. The night-time HR value that better predicted cardiovascular risk office tachycardia was more than 66 bpm. In comparison with patients with night HR below this value, those with night-time tachycardia were predominantly women, younger, with higher ambulatory blood pressure, greater BMI, and higher prevalence of diabetes and smoking. All comparisons were statistically significant (P less than 0.001). A mean night-time HR more than 66 bpm is a good predictor of cardiovascular risk office tachycardia in untreated hypertensive patients and could be considered a variable associated with an increased cardiovascular risk.

A characterization of linearly repetitive cut and project sets

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Haynes, Alan; Koivusalo, Henna; Walton, James

2018-02-01

For the development of a mathematical theory which can be used to rigorously investigate physical properties of quasicrystals, it is necessary to understand regularity of patterns in special classes of aperiodic point sets in Euclidean space. In one dimension, prototypical mathematical models for quasicrystals are provided by Sturmian sequences and by point sets generated by substitution rules. Regularity properties of such sets are well understood, thanks mostly to well known results by Morse and Hedlund, and physicists have used this understanding to study one dimensional random Schrödinger operators and lattice gas models. A key fact which plays an important role in these problems is the existence of a subadditive ergodic theorem, which is guaranteed when the corresponding point set is linearly repetitive. In this paper we extend the one-dimensional model to cut and project sets, which generalize Sturmian sequences in higher dimensions, and which are frequently used in mathematical and physical literature as models for higher dimensional quasicrystals. By using a combination of algebraic, geometric, and dynamical techniques, together with input from higher dimensional Diophantine approximation, we give a complete characterization of all linearly repetitive cut and project sets with cubical windows. We also prove that these are precisely the collection of such sets which satisfy subadditive ergodic theorems. The results are explicit enough to allow us to apply them to known classical models, and to construct linearly repetitive cut and project sets in all pairs of dimensions and codimensions in which they exist. Research supported by EPSRC grants EP/L001462, EP/J00149X, EP/M023540. HK also gratefully acknowledges the support of the Osk. Huttunen foundation.

Operation of the AM-50 cutting head under different cutting conditions

Energy Technology Data Exchange (ETDEWEB)

Sikora, W; Kusz, F; Fels, M

1988-02-01

Presents results of investigations into operation of the AM-50 heading machine. About 50% of headings, i.e. about 800 km/a, are driven by about 400 heading machines. It has been found that energy consumption depends on compression strength of rock and is 6 times higher for sandstone than for clayey shale. Power consumed by cutting heads depends mainly on the web used (30-150 mm depending on rock strength). Wear of cutting tools is 1-30 pieces per meter of heading advance at a working cross-section area of 15 m/sup 2/. The AM-50 machine uses cutting speeds of 1.1-3.5 m/s. Higher speeds negatively affect the resistance to cutting. Nonuniform tool wear on the cutting head circumference is an indication of improper head design that requires remedying.

The estimation of pork carcass primal cuts value based on backfat thickness

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Kamil Duziński

2015-03-01

Full Text Available The aim of the present study was to determine the effect of pork carcass backfat thickness on the dissection efficiency of four primal cuts (ham, loin, shoulder, belly, including correlation coefficients. The research material consisted of 80 pork carcasses. Backfat thickness (mm was measured on cold half-carcasses using a vernier caliper at 6 points: at the first cervical vertebra (atlas, over shoulder at the thickest point, on the back, at the beginning, center, end of the gluteus medius muscle (CI, CII, CIII. On the basis of the average backfat thickness, measurements from 6 points were separated into two experimental groups: I (<25 mm; II (≥25 mm. Detailed dissection of the elements was performed to define mass (g: total, intermuscular fat, bones and lean meat. The significant effect of fat thickness on intermuscular fat content regardless of the cut was noted. Correlations between the average backfat thickness of 6 points and the total weight of the four main elements were calculated. In addition, the correlation coefficients were compared between the dissection elements and the average backfat thickness of 6 and 5 points. Higher backfat thickness determined the increase in the total mass of loin, shoulder and belly. A statistically proven correlation was shown between the average backfat thickness and the total mass of the analysed elements (r=0.293. When comparing the correlation coefficients of a different number of measurements a specific tendency was observed. Positive correlation coefficients were slightly higher for an average of 5 points of backfat thickness and negative correlation coefficients were slightly higher for an average of 6 points. Statistical differences between groups were recorded at the same level for the same parameters (P≤0.001 and 0.01points can be used as an indicator of the amount and quality of pork carcass primal cuts, with no adverse effects compared to

Preoperative diagnosis of breast diseases by dynamic MR mammography. Cut off point establishment for signal intensity ratio

International Nuclear Information System (INIS)

Tsuchiya, Juji; Nagata, Takayasu; Kawagoe, Hajime; Tachibana, Susumu; Kajima, Toshihiko; Hoshino, Mutsuo; Uno, Takashi; Shimokawa, Kuniyasu.

1997-01-01

We have revealed that a dynamic study of the breast using MR imaging technique can estimate objectively benign-malignant differentiative diagnosis. Subjects were 41 cases of breast lesion, including 13 cases of breast cancer, 21 cases of mastopathy, six cases of fibroadenoma and one case of intraductal papillomatosis and the results of them were investigated in comparison with histopathological diagnosis. As so the method, we drew up time-signal intensity ratio curve plotting signal intensity ratio at each 30 second of dynamic MR mammography after Gd-DTPA administration. We found a especially high significant difference between cancer and mastopathy, within 90 second after Gd-DTPA administration (p=0.0000). Still more, we established cut off point concerning with establishment of 95% confidence interval, that is, at 30 second after Gd-DTPA administration of point equivalent 1.53 at 60 second equivalent 2.00, at 90 second equivalent 2.47, and about this estimating maneuver using the cut off point we named Dynamic ratio method. We can estimate preoperatively not only benign-malignant differentiative diagnosis with breast tumor, but also neighboring infiltration and lymph node metastasis of breast cancer using this Dynamic ratio method. Over again, Dynamic ratio method provides fine information to preoperative decision of resecting region for breast conserving surgery. The efficiency of this method is sensitivity=92.3%, specificity=89.3% and positive predictive value=80.0%. (author)

Preoperative diagnosis of breast diseases by dynamic MR mammography. Cut off point establishment for signal intensity ratio

Energy Technology Data Exchange (ETDEWEB)

Tsuchiya, Juji; Nagata, Takayasu; Kawagoe, Hajime; Tachibana, Susumu; Kajima, Toshihiko; Hoshino, Mutsuo [Ibi General Hospital, Gifu (Japan); Uno, Takashi; Shimokawa, Kuniyasu

1997-12-01

We have revealed that a dynamic study of the breast using MR imaging technique can estimate objectively benign-malignant differentiative diagnosis. Subjects were 41 cases of breast lesion, including 13 cases of breast cancer, 21 cases of mastopathy, six cases of fibroadenoma and one case of intraductal papillomatosis and the results of them were investigated in comparison with histopathological diagnosis. As so the method, we drew up time-signal intensity ratio curve plotting signal intensity ratio at each 30 second of dynamic MR mammography after Gd-DTPA administration. We found a especially high significant difference between cancer and mastopathy, within 90 second after Gd-DTPA administration (p=0.0000). Still more, we established cut off point concerning with establishment of 95% confidence interval, that is, at 30 second after Gd-DTPA administration of point equivalent 1.53 at 60 second equivalent 2.00, at 90 second equivalent 2.47, and about this estimating maneuver using the cut off point we named Dynamic ratio method. We can estimate preoperatively not only benign-malignant differentiative diagnosis with breast tumor, but also neighboring infiltration and lymph node metastasis of breast cancer using this Dynamic ratio method. Over again, Dynamic ratio method provides fine information to preoperative decision of resecting region for breast conserving surgery. The efficiency of this method is sensitivity=92.3%, specificity=89.3% and positive predictive value=80.0%. (author)

The CDC and IOTF cut points show inconsistent prevalence of underweight and overweight in chinese, indonesian, and vietnamese children

Science.gov (United States)

No nationally representative data from middle and low-income countries have been analyzed to compare prevalence of underweight and overweight defined by the Centers for Disease Control and Prevention (CDC) and the International Obesity Task Force (IOTF) BMI cut points. We evaluated the consistency i...

Punto de corte óptimo de la concentración de cotinina en saliva para discriminar entre fumadores y no fumadores en la población adulta de Barcelona Optimal cut-point of salivary cotinine concentration to discriminate smoking status in the adult population in Barcelona

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Jose M. Martínez-Sánchez

2009-12-01

specificity according to sex, age, smoking status (daily and occasional, and exposure to second-hand smoke at home. ROC curves and the area under the curve were calculated. Results: The prevalence of smokers (daily and occasional was 27.8% (95% CI: 25.2-30.4%. The optimal cut-point to discriminate smoking status was 9.2ng/ml (sensitivity=88.7% and specificity=89.0%. The area under the ROC curve was 0.952. The optimal cut-point was 12.2ng/ml in men and 7.6ng/ml in women. The optimal cut-point was higher at ages with a greater prevalence of smoking. Daily smokers had a higher cut-point than occasional smokers. Conclusions: The optimal cut-point to discriminate smoking status in the adult population is 9.2ng/ml, with sensitivities and specificities around 90%. The cut-point was higher in men and in younger people. The cut-point increases with higher prevalence of daily smokers.

A Study on Ultrasonic Elliptical Vibration Cutting of Inconel 718

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Zhao Haidong

2016-01-01

Full Text Available Inconel 718 is a kind of nickel-based alloys that are widely used in the aerospace and nuclear industry owing to their high temperature mechanical properties. Cutting of Inconel 718 in conventional cutting (CC is a big challenge in modern industry. Few researches have been studied on cutting of Inconel 718 using single point diamond tool applying the UEVC method. This paper shows an experimental study on UEVC of Inconel 718 by using polycrystalline diamond (PCD coated tools. Firstly, cutting tests have been carried out to study the effect of machining parameters in the UEVC in terms of surface finish and flank wear during machining of Inconel 718. The tests have clearly shown that the PCD coated tools in cutting of Inconel 718 by the UEVC have better performance at 0.1 mm depth of cut as compared to the lower 0.05 mm depth of cut and the higher 0.12 or 0.15 mm depth of cut. Secondly, like CC method, the cutting performance in UEVC increases with the decrease of the feed rate and cutting speed. The CC tests have also been carried out to compare performance of CC with UEVC method.

Dental fear and caries in 6-12 year old children in Greece. Determination of dental fear cut-off points.

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Boka, V; Arapostathis, K; Karagiannis, V; Kotsanos, N; van Loveren, C; Veerkamp, J

2017-03-01

To present: the normative data on dental fear and caries status; the dental fear cut-off points of young children in the city of Thessaloniki, Greece. Study Design: This is a cross-sectional study with two independent study groups. A first representative sample consisted of 1484 children from 15 primary public schools of Thessaloniki. A second sample consisted of 195 randomly selected age-matched children, all patients of the Postgraduate Paediatric Dental Clinic of Aristotle University of Thessaloniki. First sample: In order to select data on dental fear and caries, dental examination took place in the classroom with disposable mirrors and a penlight. All the children completed the Dental Subscale of the Children's Fear Survey Schedule (CFSS-DS). Second sample: In order to define the cut-off points of the CFSS-DS, dental treatment of the 195 children was performed at the University Clinic. Children⁁s dental fear was assessed using the CFSS-DS and their behaviour during dental treatment was observed by one calibrated examiner using the Venham scale. Statistical analysis of the data was performed with IBM SPSS Statistics 20 at a statistical significance level of fear. Mean differences between boys and girls were not significant. Caries was not correlated with dental fear. Second sample: CFSS-DSfear', scores 33-37 as 'borderline' and scores > 37 as 'dental fear'. In the first sample, 84.6% of the children did not suffer from dental fear (CFSS-DSfear was correlated to age and not to caries and gender. The dental fear cut-off point for the CFSS-DS was estimated at 37 for 6-12 year old children (33-37 borderlines).

Influence of cutting parameters on the depth of subsurface deformed layer in nano-cutting process of single crystal copper.

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Wang, Quanlong; Bai, Qingshun; Chen, Jiaxuan; Su, Hao; Wang, Zhiguo; Xie, Wenkun

2015-12-01

Large-scale molecular dynamics simulation is performed to study the nano-cutting process of single crystal copper realized by single-point diamond cutting tool in this paper. The centro-symmetry parameter is adopted to characterize the subsurface deformed layers and the distribution and evolution of the subsurface defect structures. Three-dimensional visualization and measurement technology are used to measure the depth of the subsurface deformed layers. The influence of cutting speed, cutting depth, cutting direction, and crystallographic orientation on the depth of subsurface deformed layers is systematically investigated. The results show that a lot of defect structures are formed in the subsurface of workpiece during nano-cutting process, for instance, stair-rod dislocations, stacking fault tetrahedron, atomic clusters, vacancy defects, point defects. In the process of nano-cutting, the depth of subsurface deformed layers increases with the cutting distance at the beginning, then decreases at stable cutting process, and basically remains unchanged when the cutting distance reaches up to 24 nm. The depth of subsurface deformed layers decreases with the increase in cutting speed between 50 and 300 m/s. The depth of subsurface deformed layer increases with cutting depth, proportionally, and basically remains unchanged when the cutting depth reaches over 6 nm.

Laser cutting system

Science.gov (United States)

Dougherty, Thomas J

2015-03-03

A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

Material Behavior At The Extreme Cutting Edge In Bandsawing

International Nuclear Information System (INIS)

Sarwar, Mohammed; Haider, Julfikar; Persson, Martin; Hellbergh, Haakan

2011-01-01

In recent years, bandsawing has been widely accepted as a favourite option for metal cutting off operations where the accuracy of cut, good surface finish, low kerf loss, long tool life and high material removal rate are required. Material removal by multipoint cutting tools such as bandsaw is a complex mechanism owing to the geometry of the bandsaw tooth (e.g., limited gullet size, tooth setting etc.) and the layer of material removed or undeformed chip thickness or depth of cut (5 μm-50 μm) being smaller than or equal to the cutting edge radius (5 μm-15 μm). This situation can lead to inefficient material removal in bandsawing. Most of the research work are concentrated on the mechanics of material removal by single point cutting tool such as lathe tool. However, such efforts are very limited in multipoint cutting tools such as in bandsaw. This paper presents the fundamental understanding of the material behaviour at the extreme cutting edge of bandsaw tooth, which would help in designing and manufacturing of blades with higher cutting performance and life. ''High Speed Photography'' has been carried out to analyse the material removal process at the extreme cutting edge of bandsaw tooth. Geometric model of chip formation mechanisms based on the evidences found during ''High Speed Photography'' and ''Quick Stop'' process is presented. Wear modes and mechanism in bimetal and carbide tipped bandsaw teeth are also presented.

Optimal Cut-Off Points for the Short-Negative Act Questionnaire and Their Association with Depressive Symptoms and Diagnosis of Depression

DEFF Research Database (Denmark)

Conway, Paul Maurice; Høgh (Hogh), Annie; Nabe-Nielsen, Kirsten

2018-01-01

to depressive symptoms and diagnosis of depression. Methods The study was based on a sample of 4882 participants from the Danish MODENA cohort study (year 2011), which included both the S-NAQ (score range 9–45) and a one-item measure applying the self-labelling method with a definition to assess occasional...... its criterion validity in relation to depressive symptoms (N = 4071) and diagnosis of depression (N = 4844). Results The S-NAQ cut-off points obtained were ≥12 and ≥16 when using occasional and frequent bullying as reference standards, respectively. Both cut-off points showed high classification.......44–1.86) were significantly associated with depressive symptoms. In the adjusted logistic regression analyses, both the first (odds ratio [OR] = 3.55, 95% CI = 1.98–6.38) and the second threshold of exposure (OR = 5.90, 95% CI = 2.93–11.88) were significantly associated with diagnosis of depression. Conclusions...

Validation of Cut-Points for Evaluating the Intensity of Physical Activity with Accelerometry-Based Mean Amplitude Deviation (MAD.

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Henri Vähä-Ypyä

Full Text Available Our recent study of three accelerometer brands in various ambulatory activities showed that the mean amplitude deviation (MAD of the resultant acceleration signal performed best in separating different intensity levels and provided excellent agreement between the three devices. The objective of this study was to derive a regression model that estimates oxygen consumption (VO2 from MAD values and validate the MAD-based cut-points for light, moderate and vigorous locomotion against VO2 within a wide range of speeds.29 participants performed a pace-conducted non-stop test on a 200 m long indoor track. The initial speed was 0.6 m/s and it was increased by 0.4 m/s every 2.5 minutes until volitional exhaustion. The participants could freely decide whether they preferred to walk or run. During the test they carried a hip-mounted tri-axial accelerometer and mobile metabolic analyzer. The MAD was calculated from the raw acceleration data and compared to directly measured incident VO2. Cut-point between light and moderate activity was set to 3.0 metabolic equivalent (MET, 1 MET = 3.5 ml · kg-1 · min-1 and between moderate and vigorous activity to 6.0 MET as per standard use.The MAD and VO2 showed a very strong association. Within individuals, the range of r values was from 0.927 to 0.991 providing the mean r = 0.969. The optimal MAD cut-point for 3.0 MET was 91 mg (milligravity and 414 mg for 6.0 MET.The present study showed that the MAD is a valid method in terms of the VO2 within a wide range of ambulatory activities from slow walking to fast running. Being a device-independent trait, the MAD facilitates directly comparable, accurate results on the intensity of physical activity with all accelerometers providing tri-axial raw data.

Chronic defensiveness and neuroendocrine dysfunction reflect a novel cardiac troponin T cut point: The SABPA study.

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Malan, Leoné; Hamer, Mark; von Känel, Roland; Lambert, Gavin W; Delport, Rhena; Steyn, Hendrik S; Malan, Nicolaas T

2017-11-01

Sympatho-adrenal responses are activated as an innate defense coping (DefS) mechanism during emotional stress. Whether these sympatho-adrenal responses drive cardiac troponin T (cTnT) increases are unknown. Therefore, associations between cTnT and sympatho-adrenal responses were assessed. A prospective bi-ethnic cohort, excluding atrial fibrillation, myocardial infarction and stroke cases, was followed for 3 years (N=342; 45.6±9.0years). We obtained serum high-sensitive cTnT and exposure measures [Coping-Strategy-Indicator, depression/Patient-Health-Questionnarie-9, 24h BP, 24h heart-rate-variability (HRV) and 24h urinary catecholamines]. Blacks showed moderate depression (45% vs. 16%) and 24h hypertension (67% vs. 42%) prevalence compared to Whites. A receiver-operating-characteristics cTnT cut-point 4.2ng/L predicting hypertension in Blacks was used as binary outcome measure in relation to exposure measures [AUC 0.68 (95% CI 0.60-0.76); sensitivity/specificity 63/70%; P≤0.001]. Bi-ethnic cTnT-incidence was similar (Blacks=27%, Whites=25%) with cTnT-recovery better in Blacks (9%) compared to Whites (5%), P=0.001. In cross-sectional analyses, elevated cTnT was related to DefS [OR 1.08 (95% CI 0.99-1.16); P=0.06]; 24h BP [OR 1.03-1.04 (95% CI 1.01-1.08); P≤0.02] and depressed HRV [OR 2.19 (95% CI 1.09-4.41); P=0.03] in Blacks, but not in Whites. At 3year follow-up, elevated cTnT was related to attenuated urine norepinephrine:creatinine ratio in Blacks [OR 1.46 (95% CI 1.01-2.10); P=0.04]. In Whites, a cut point of 5.6ng/L cTnT predicting hypertension was not associated with exposure measures. Central neural control systems exemplified a brain-heart stress pathway. Desensitization of sympatho-adrenal responses occurred with initial neural- (HRV) followed by neuroendocrine dysfunction (norepinephrine:creatinine) in relation to elevated cTnT. Chronic defensiveness may thus drive the desensitization or physiological depression, reflecting ischemic heart disease

Putative Dementia Cases Fluctuate as a Function of Mini-Mental State Examination Cut-Off Points.

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Rosa, Ilka M; Henriques, Ana G; Wiltfang, Jens; da Cruz E Silva, Odete A B

2018-01-01

As the population ages, there is a growing need to quickly and accurately identify putative dementia cases. Many cognitive tests are available; among those commonly used are the Cognitive Dementia Rating (CDR) and the Mini-Mental Status Examination (MMSE). The aim of this work was to compare the validity and reliability of these cognitive tests in a primary care based cohort (pcb-Cohort). The MMSE and the CDR were applied to 568 volunteers in the pcb-Cohort. Distinct cut-off points for the MMSE were considered, namely MMSE 27, MMSE 24, and MMSE PT (adapted for the Portuguese population). The MMSE 27 identified the greatest number of putative dementia cases, and, as determined by the ROC curve, it was the most sensitive and specific of the MMSE cut-offs considered. Putative predictive or risk factors identified included age, literacy, depression, and diabetes mellitus (DM). DM has previously been indicated as a risk factor for dementia and Alzheimer's disease. Comparatively, the MMSE 27 cut-off has the greatest sensibility (94.9%) and specificity (66.3%) when compared to MMSE PT and MMSE 24. Upon comparing MMSE and CDR scores, the latter identified a further 146 putative dementia cases, thus permitting one to propose that in an ideal situation, both tests should be employed. This increases the likelihood of identifying putative dementia cases for subsequent follow up work, thus these cognitive tests represent important tools in patient care. Further, this is a significant study for Portuguese populations, where few of these studies have been carried out.

Identification of the critical depth-of-cut through a 2D image of the cutting region resulting from taper cutting of brittle materials

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Gu, Wen; Zhu, Zhiwei; Zhu, Wu-Le; Lu, Leyao; To, Suet; Xiao, Gaobo

2018-05-01

An automatic identification method for obtaining the critical depth-of-cut (DoC) of brittle materials with nanometric accuracy and sub-nanometric uncertainty is proposed in this paper. With this method, a two-dimensional (2D) microscopic image of the taper cutting region is captured and further processed by image analysis to extract the margin of generated micro-cracks in the imaging plane. Meanwhile, an analytical model is formulated to describe the theoretical curve of the projected cutting points on the imaging plane with respect to a specified DoC during the whole cutting process. By adopting differential evolution algorithm-based minimization, the critical DoC can be identified by minimizing the deviation between the extracted margin and the theoretical curve. The proposed method is demonstrated through both numerical simulation and experimental analysis. Compared with conventional 2D- and 3D-microscopic-image-based methods, determination of the critical DoC in this study uses the envelope profile rather than the onset point of the generated cracks, providing a more objective approach with smaller uncertainty.

Determining the cut-off point of osteoporosis based on the osteoporosis self-assessment tool, body mass index and weight in Taiwanese young adult women.

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Chang, Shu Fang; Yang, Rong Sen

2014-09-01

To examine the cut-off point of the osteoporosis self-assessment tool, age, weight and body mass index for osteoporosis among young adult Taiwanese women, using a large-scale health examination database containing bone mineral density tests. The cut-off points of osteoporosis risk factors identified earlier focus on menopausal or senior Caucasian and Asian women. However, young adult Asian women have seldom been identified. A retrospective historical cohort study. Using the 2009-2011 health examination database of a large-scale medical centre in northern Taiwan, this study investigated young adult Asian women (i.e. range in age from 30-49 years) in Taiwan who had received dual-energy X-ray absorptiometry test. This study also explored the cut-off point, sensitivity, specificity and diagnostic accuracy of receiver operating characteristics of osteoporosis among young adult females in Taiwan. This study collected 2454 young adult Asian women in Taiwan. Cochran-Armitage analysis results indicated that the prevalence of osteoporosis increased with decreasing weight, body mass index and osteoporosis self-assessment method quartiles. According to the results of receiver operating characteristics, weight, body mass index and osteoporosis self-assessment tool approaches can generally be used as indicators to predict osteoporosis among young adult Asian women. Results of this study demonstrate that Taiwanese women contracting osteoporosis tend to be young and underweight, as well as having a low body mass index and osteoporosis self-assessment scores. Those results further suggest that the assessment indicators for cut-off points are appropriately suitable for young adult women in Taiwan. Early detection is the only available means of preventing osteoporosis. Professional nurses should apply convenient and accurate assessment procedures to help young adult women to adopt preventive strategies against osteoporosis early, thus eliminating the probability of osteoporotic

Consumer evaluation of palatability characteristics of a beef value-added cut compared to common retail cuts.

Science.gov (United States)

Lepper-Blilie, A N; Berg, E P; Germolus, A J; Buchanan, D S; Berg, P T

2014-01-01

The objectives of this study were to educate consumers about value-added beef cuts and evaluate their palatability responses of a value cut and three traditional cuts. Three hundred and twenty-two individuals participated in the beef value cut education seminar series presented by trained beef industry educators. Seminar participants evaluated tenderness, juiciness, flavor, and overall like of four samples, bottom round, top sirloin, ribeye, and a value cut (Delmonico or Denver), on a 9-point scale. The ribeye and the value cut were found to be similar in all four attributes and differed from the top sirloin and bottom round. Correlations and regression analysis found that flavor was the largest influencing factor for overall like for the ribeye, value cut, and top sirloin. The value cut is comparable to the ribeye and can be a less expensive replacement. © 2013.

Experimental Investigation on Cutting Characteristics in Nanometric Plunge-Cutting of BK7 and Fused Silica Glasses.

Science.gov (United States)

An, Qinglong; Ming, Weiwei; Chen, Ming

2015-03-27

Ductile cutting are most widely used in fabricating high-quality optical glass components to achieve crack-free surfaces. For ultra-precision machining of brittle glass materials, critical undeformed chip thickness (CUCT) commonly plays a pivotal role in determining the transition point from ductile cutting to brittle cutting. In this research, cutting characteristics in nanometric cutting of BK7 and fused silica glasses, including machined surface morphology, surface roughness, cutting force and specific cutting energy, were investigated with nanometric plunge-cutting experiments. The same cutting speed of 300 mm/min was used in the experiments with single-crystal diamond tool. CUCT was determined according to the mentioned cutting characteristics. The results revealed that 320 nm was found as the CUCT in BK7 cutting and 50 nm was determined as the size effect of undeformed chip thickness. A high-quality machined surface could be obtained with the undeformed chip thickness between 50 and 320 nm at ductile cutting stage. Moreover, no CUCT was identified in fused silica cutting with the current cutting conditions, and brittle-fracture mechanism was confirmed as the predominant chip-separation mode throughout the nanometric cutting operation.

Determinants of self-reported smoking and misclassification during pregnancy, and analysis of optimal cut-off points for urinary cotinine: a cross-sectional study.

Science.gov (United States)

Aurrekoetxea, Juan J; Murcia, Mario; Rebagliato, Marisa; López, María José; Castilla, Ane Miren; Santa-Marina, Loreto; Guxens, Mónica; Fernández-Somoano, Ana; Espada, Mercedes; Lertxundi, Aitana; Tardón, Adonina; Ballester, Ferran

2013-01-24

To estimate the prevalence and factors associated with smoking and misclassification in pregnant women from INMA (INfancia y Medio Ambiente, Environment and Childhood) project, Spain, and to assess the optimal cut-offs for urinary cotinine (UC) that best distinguish daily and occasional smokers with varying levels of second-hand smoke (SHS) exposure. We used logistic regression models to study the relationship between sociodemographic variables and self-reported smoking and misclassification (self-reported non-smokers with UC >50 ng/ml). Receiver operating characteristic (ROC) curves were used to calculate the optimal cut-off point for discriminating smokers. The cut-offs were also calculated after stratification among non-smokers by the number of sources of SHS exposure. The cut-off points used to discriminate smoking status were the level of UC given by Youden's index and for 50 and 100 ng/ml for daily smokers, or 25 and 50 ng/ml for occasional smokers. At the third trimester of pregnancy, 2263 pregnant women of the INMA Project were interviewed between 2004 and 2008 and a urine sample was collected. Prevalence of self-reported smokers at the third trimester of pregnancy was 18.5%, and another 3.9% misreported their smoking status. Variables associated with self-reported smoking and misreporting were similar, including born in Europe, educational level and exposure to SHS. The optimal cut-off was 82 ng/ml (95% CI 42 to 133), sensitivity 95.2% and specificity 96.6%. The area under the ROC curve was 0.986 (95% CI 0.982 to 0.990). The cut-offs varied according to the SHS exposure level being 42 (95% CI 27 to 57), 82 (95% CI 46 to 136) and 106 ng/ml (95% CI 58 to 227) for not being SHS exposed, exposed to one, and to two or more sources of SHS, respectively. The optimal cut-off for discriminating occasional smokers from non-smokers was 27 ng/ml (95% CI 11 to 43). Prevalence of smoking during pregnancy in Spain remains high. UC is a reliable biomarker for classifying

Determinants of self-reported smoking and misclassification during pregnancy, and analysis of optimal cut-off points for urinary cotinine: a cross-sectional study

Science.gov (United States)

Aurrekoetxea, Juan J; Murcia, Mario; Rebagliato, Marisa; López, María José; Castilla, Ane Miren; Santa-Marina, Loreto; Guxens, Mónica; Fernández-Somoano, Ana; Espada, Mercedes; Lertxundi, Aitana; Tardón, Adonina; Ballester, Ferran

2013-01-01

Objectives To estimate the prevalence and factors associated with smoking and misclassification in pregnant women from INMA (INfancia y Medio Ambiente, Environment and Childhood) project, Spain, and to assess the optimal cut-offs for urinary cotinine (UC) that best distinguish daily and occasional smokers with varying levels of second-hand smoke (SHS) exposure. Design We used logistic regression models to study the relationship between sociodemographic variables and self-reported smoking and misclassification (self-reported non-smokers with UC >50 ng/ml). Receiver operating characteristic (ROC) curves were used to calculate the optimal cut-off point for discriminating smokers. The cut-offs were also calculated after stratification among non-smokers by the number of sources of SHS exposure. The cut-off points used to discriminate smoking status were the level of UC given by Youden's index and for 50 and 100 ng/ml for daily smokers, or 25 and 50 ng/ml for occasional smokers. Participants At the third trimester of pregnancy, 2263 pregnant women of the INMA Project were interviewed between 2004 and 2008 and a urine sample was collected. Results Prevalence of self-reported smokers at the third trimester of pregnancy was 18.5%, and another 3.9% misreported their smoking status. Variables associated with self-reported smoking and misreporting were similar, including born in Europe, educational level and exposure to SHS. The optimal cut-off was 82 ng/ml (95% CI 42 to 133), sensitivity 95.2% and specificity 96.6%. The area under the ROC curve was 0.986 (95% CI 0.982 to 0.990). The cut-offs varied according to the SHS exposure level being 42 (95% CI 27 to 57), 82 (95% CI 46 to 136) and 106 ng/ml (95% CI 58 to 227) for not being SHS exposed, exposed to one, and to two or more sources of SHS, respectively. The optimal cut-off for discriminating occasional smokers from non-smokers was 27 ng/ml (95% CI 11 to 43). Conclusions Prevalence of smoking during pregnancy in

Cut Locus Construction using Deformable Simplicial Complexes

DEFF Research Database (Denmark)

Misztal, Marek Krzysztof; Bærentzen, Jakob Andreas; Anton, François

2011-01-01

In this paper we present a method for appproximating cut loci for a given point p on Riemannian 2D manifolds, closely related to the notion of Voronoi diagrams. Our method finds the cut locus by advecting a front of points equally distant from p along the geodesics originating at p and finding...... the domain to have disk topology. We test our method for tori of revolution and compare our results to the benchmark ones from [2]. The method, however, is generic and can be easily adapted to construct cut loci for other manifolds of genera other than 1....

Appropriate neck circumference cut-off points for metabolic syndrome in Turkish patients with type 2 diabetes.

Science.gov (United States)

Ozkaya, Ismail; Yardimci, Bulent; Tunckale, Aydin

2017-12-01

To investigate the association between neck circumference (NC), overweight, and metabolic syndrome (MS) in Turkish patients with type 2 diabetes. A total of 264 diabetic patients (mean age: 52.9±8.1 years) were recruited from two centers in Istanbul to perform anthropometric measurements, including waist and hip circumference, NC, and body mass index. Blood pressure, fasting glucose, and lipid profile (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglyceride levels) were determined. NC correlated with waist circumference, systolic blood pressure, and triglycerides in men, whereas NC only correlated with waist circumference in women. Additionally, NC was shown to negatively correlate with high-density lipoprotein cholesterol in both men and women. Receiver operating characteristic analysis showed that the area under the curve for NC and overweight was 0.95 for both men and women (P<0.001). Moreover, a NC of 38cm for men and 37cm for women was the best cut-off point for determining overweight. The area under the curve for NC and MS was 0.87 for men and 0.83 for women (P<0.001). A NC of 39cm for men and 37cm for women was the best cut-off point to determine participants with MS. Our findings suggest a positive correlation of NC with MetS in Turkish patients with type 2 diabetes, and could be a useful and accurate tool to identify MS. Copyright © 2017 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

Comparison of CO2 Laser Cutting with Different Laser Sources

DEFF Research Database (Denmark)

Ketting, Hans-Ole; Olsen, Flemmming Ove

1996-01-01

This paper contains CO2 laser cutting results in mild and stainless steel with different laser sources. The main factors which affect the cutting speed and quality are the power, the cutting gas and focal point conditions. Keeping the power and cutting gas constant, the focal point conditions have...... size,for the maximum cutting speed. One of the 7 laser sources with different focal length and thus different minimum spot size, was then used to investigate more in details the importance of the focal spot size cutting stainless steel with high pressure nitrogen. It looks as if there is a strong...... connection between the smallest avail-able spot size and cutting speed in mild steel, whereas the conditions in stainless steel, depends strongly on the flow conditions in the cut kerf, and not only on the focal spot size....

Preferences of cut flowers consumers

Directory of Open Access Journals (Sweden)

Sylwia Kierczyńska

2010-01-01

Full Text Available The results of interviews suggest that majority of the cut flowers’ consumers has favourite kind of flower, among which most frequently pointed one was the rose. More than half of the interviewed favour the uniform colour of cut flowers and red colour was the most favourite one. The subtle smell of flowers was the most preferable one but the intensive fragrance was favoured for more consumers than odourless flowers. The data from selected florists’ confirm the information from interviews – in spite of the occasion, roses were the most demanded cut flowers.

Aerodynamic Interactions During Laser Cutting

Science.gov (United States)

Fieret, J.; Terry, M. J.; Ward, B. A.

1986-11-01

Most laser cutting systems utilise a gas jet to remove molten or vaporised material from the kerf. The speed, economy and quality of the cut can be strongly dependent on the aerodynamic conditions created by the nozzle, workpiece proximity and kerf shape. Adverse conditions can be established that may lead to an unwelcome lack of reproducibility of cut quality. Relatively low gas nozzle pressures can result in supersonic flow in the jet with its associated shock fronts. When the nozzle is placed at conventional distances (1-2mm) above the workpiece, the force exerted by the gas on the workpiece and the cut products (the cutting pressure) can be significantly less than the nozzle pressure. Higher cutting pressures can be achieved by increasing the height of the nozzle above the workpiece, to a more damage resistant zone, provided that the shock structure of the jet is taken into account. Conventional conical nozzles with circular exits can be operated with conditions that will result in cutting pressures up to 3 Bar (g) in the more distant zone. At higher pressures in circular tipped nozzles the cutting pressure in this zone decays to inadequate levels. Investigations of a large number of non-circular nozzle tip shapes have resulted in the selection of a few specific shapes that can provide cutting pressures in excess of 6 Bar(g) at distances of 4 to 7mm from the nozzle tip. Since there is a strong correlation between cutting pressure and the speed and quality of laser cutting, the paper describes the aerodynamic requirements for achieving the above effects and reports the cutting results arising from the different nozzle designs and conditions. The results of the work of other investigators, who report anomalous laser cutting results, will be examined and reviewed in the light of the above work.

Ceramic cutting tools materials, development and performance

CERN Document Server

Whitney, E Dow

1994-01-01

Interest in ceramics as a high speed cutting tool material is based primarily on favorable material properties. As a class of materials, ceramics possess high melting points, excellent hardness and good wear resistance. Unlike most metals, hardness levels in ceramics generally remain high at elevated temperatures which means that cutting tip integrity is relatively unaffected at high cutting speeds. Ceramics are also chemically inert against most workmetals.

On the Cutting Performance of Segmented Diamond Blades when Dry-Cutting Concrete.

Science.gov (United States)

Sánchez Egea, A J; Martynenko, V; Martínez Krahmer, D; López de Lacalle, L N; Benítez, A; Genovese, G

2018-02-09

The objective of the present study is to analyze and compare the cutting performance of segmented diamond blades when dry-cutting concrete. A cutting criteria is proposed to characterize the wear of the blades by measuring the variation of the external diameter and the weight loss of the blade. The results exhibit the cutting blade SB-A, which has twice the density of diamonds and large contact area, exhibits less wear even though the material removal rate is higher compared with the other two cutting blades. Additionally, the surface topography of the different blades is evaluated to examine the impact of wear depending on the surface profile and the distribution of the diamonds in the blade's matrix. Large number of diamonds pull-out are found in blades type SB-C, which additionally shows the worst wear resistant capability. As a conclusion, the cutting efficiency of the blade is found to be related to the density of embedded diamonds and the type of the surface profile of the cutting blade after reaching the stop criteria.

To choose the cut-off point of ferritin for differentiation between benign from malignant pleural-peritoneal effusion

International Nuclear Information System (INIS)

Yang Liu; Yang Wenjing; Liu Junfeng; Yu Jiuru

2005-01-01

To explore the level of ferritin for differentiating the benign from malignant pleural and peritoneal effusion, 218 pleural-peritoneal effusion samples from patients with different kinds of diseases were determined for ferritin (P Ft ) by RIA, in the meanwhile serum ferritin (S Ft ) was also determined. According to clinical diagnosis, these samples were divided into two groups: benign and malignant. P Ft and S Ft were compared between these two groups, and the ratio of P Ft to S Ft was counted. The ROC curve was used to choose the best cut-off point P Ft for differentiating benign from malignant pleural and peritoneal effusion. The results showed that in the benign effusion group the P Ft was 142.4±38.6 μg/L, S Ft was 89.7±43.5 μg/L, and P Ft / S Ft was 1.46±0.55, whereas in the group of malignant effusion the corresponding figures were 576.5±239.l μg/L, 189.±81.7 μg/L, and 3.67±1.48, respectively. The cut-off point for differentiating benign from malignant pleural and peritoneal effusion was 400 μg/L. Our differentiation standards are: P Ft ≥400 μg/L,P Ft /S Ft ≥3 for the malignant pleural and peritoneal ef- fusion, and P Ft Ft /S Ft <3 for the benign effusion. The sensitivity is 84.5%, the specificity is 87.5%, and the accuracy is 92.8%. (authors)

Cut points on 0-10 numeric rating scales for symptoms included in the edmonton symptom assessment scale in cancer patients: A systematic review

NARCIS (Netherlands)

W.H. Oldenmenger (Wendy); P.J. de Raaf (Pleun); C. de Klerk (Cora); C.C.D. van der Rijt (Carin)

2013-01-01

textabstractContext: To improve the management of cancer-related symptoms, systematic screening is necessary, often performed by using 0-10 numeric rating scales. Cut points are used to determine if scores represent clinically relevant burden. Objectives: The aim of this systematic review was to

Optimal waist circumference cut-off points and ability of different metabolic syndrome criteria for predicting diabetes in Japanese men and women: Japan Epidemiology Collaboration on Occupational Health Study

Directory of Open Access Journals (Sweden)

Huanhuan Hu

2016-03-01

Full Text Available Abstract Background We sought to establish the optimal waist circumference (WC cut-off point for predicting diabetes mellitus (DM and to compare the predictive ability of the metabolic syndrome (MetS criteria of the Joint Interim Statement (JIS and the Japanese Committee of the Criteria for MetS (JCCMS for DM in Japanese. Methods Participants of the Japan Epidemiology Collaboration on Occupational Health Study, who were aged 20–69 years and free of DM at baseline (n = 54,980, were followed-up for a maximum of 6 years. Time-dependent receiver operating characteristic analysis was used to determine the optimal cut-off points of WC for predicting DM. Time-dependent sensitivity, specificity, and positive and negative predictive values for the prediction of DM were compared between the JIS and JCCMS MetS criteria. Results During 234,926 person-years of follow-up, 3180 individuals developed DM. Receiver operating characteristic analysis suggested that the most suitable cut-off point of WC for predicting incident DM was 85 cm for men and 80 cm for women. MetS was associated with 3–4 times increased hazard for developing DM in men and 7–9 times in women. Of the MetS criteria tested, the JIS criteria using our proposed WC cut-off points (85 cm for men and 80 cm for women had the highest sensitivity (54.5 % for men and 43.5 % for women for predicting DM. The sensitivity and specificity of the JCCMS MetS criteria were ~37.7 and 98.9 %, respectively. Conclusion Data from the present large cohort of workers suggest that WC cut-offs of 85 cm for men and 80 cm for women may be appropriate for predicting DM for Japanese. The JIS criteria can detect more people who later develop DM than does the JCCMS criteria.

Determination of moderate-to-severe postoperative pain on the numeric rating scale: a cut-off point analysis applying four different methods.

Science.gov (United States)

Gerbershagen, H J; Rothaug, J; Kalkman, C J; Meissner, W

2011-10-01

Cut-off points (CPs) of the numeric rating scale (NRS 0-10) are regularly used in postoperative pain treatment. However, there is insufficient evidence to identify the optimal CP between mild and moderate pain. A total of 435 patients undergoing general, trauma, or oral and maxillofacial surgery were studied. To determine the optimal CP for pain treatment, four approaches were used: first, patients estimated their tolerable postoperative pain intensity before operation; secondly, 24 h after surgery, they indicated if they would have preferred to receive more analgesics; thirdly, satisfaction with pain treatment was analysed, and fourthly, multivariate analysis was used to calculate the optimal CP for pain intensities in relation to pain-related interference with movement, breathing, sleep, and mood. The estimated tolerable postoperative pain before operation was median (range) NRS 4.0 (0-10). Patients who would have liked more analgesics reported significantly higher average pain since surgery [median NRS 5.0 (0-9)] compared with those without this request [NRS 3.0 (0-8)]. Patients satisfied with pain treatment reported an average pain intensity of median NRS 3.0 (0-8) compared with less satisfied patients with NRS 5.0 (2-9). Analysis of average postoperative pain in relation to pain-related interference with mood and activity indicated pain categories of NRS 0-2, mild; 3-4, moderate; and 5-10, severe pain. Three of the four methods identified a treatment threshold of average pain of NRS≥4. This was considered to identify patients with pain of moderate-to-severe intensity. This cut-off was indentified as the tolerable pain threshold.

Test of remote control cutting equipment by Nd:YAG laser

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Akio [Fuji Electric Corp. Research and Development Ltd., Yokosuka, Kanagawa (Japan); Hosoda, Hiroshi

1997-11-01

Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. This report is described the result of experiment by test equipment, about element technology of remote controlled cutting nuclear equipments. (author)

Test of remote control cutting equipment by Nd:YAG laser

International Nuclear Information System (INIS)

Shimizu, Akio; Hosoda, Hiroshi.

1997-01-01

Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. This report is described the result of experiment by test equipment, about element technology of remote controlled cutting nuclear equipments. (author)

Sharper angle, higher risk? The effect of cutting angle on knee mechanics in invasion sport athletes.

Science.gov (United States)

Schreurs, Mervin J; Benjaminse, Anne; Lemmink, Koen A P M

2017-10-03

Cutting is an important skill in team-sports, but unfortunately is also related to non-contact ACL injuries. The purpose was to examine knee kinetics and kinematics at different cutting angles. 13 males and 16 females performed cuts at different angles (45°, 90°, 135° and 180°) at maximum speed. 3D kinematics and kinetics were collected. To determine differences across cutting angles (45°, 90°, 135° and 180°) and sex (female, male), a 4×2 repeated measures ANOVA was conducted followed by post hoc comparisons (Bonferroni) with alpha level set at α≤0.05a priori. At all cutting angles, males showed greater knee flexion angles than females (pcutting angles with no differences in the amount of knee flexion -42.53°±8.95°, females decreased their knee flexion angle from -40.6°±7.2° when cutting at 45° to -36.81°±9.10° when cutting at 90°, 135° and 180° (pcutting towards sharper angles (pcutting angles and then stabilized compared to the 45° cutting angle (pcutting to sharper angles (pcutting angles demand different knee kinematics and kinetics. Sharper cutting angles place the knee more at risk. However, females and males handle this differently, which has implications for injury prevention. Copyright © 2017 Elsevier Ltd. All rights reserved.

Laser cutting of various materials: Kerf width size analysis and life cycle assessment of cutting process

Science.gov (United States)

Yilbas, Bekir Sami; Shaukat, Mian Mobeen; Ashraf, Farhan

2017-08-01

Laser cutting of various materials including Ti-6Al-4V alloy, steel 304, Inconel 625, and alumina is carried out to assess the kerf width size variation along the cut section. The life cycle assessment is carried out to determine the environmental impact of the laser cutting in terms of the material waste during the cutting process. The kerf width size is formulated and predicted using the lump parameter analysis and it is measured from the experiments. The influence of laser output power and laser cutting speed on the kerf width size variation is analyzed using the analytical tools including scanning electron and optical microscopes. In the experiments, high pressure nitrogen assisting gas is used to prevent oxidation reactions in the cutting section. It is found that the kerf width size predicted from the lump parameter analysis agrees well with the experimental data. The kerf width size variation increases with increasing laser output power. However, this behavior reverses with increasing laser cutting speed. The life cycle assessment reveals that material selection for laser cutting is critical for the environmental protection point of view. Inconel 625 contributes the most to the environmental damages; however, recycling of the waste of the laser cutting reduces this contribution.

Comparison of interferon-γ release assay to two cut-off points of tuberculin skin test to detect latent Mycobacterium tuberculosis infection in primary health care workers.

Directory of Open Access Journals (Sweden)

Fernanda Mattos de Souza

Full Text Available An interferon-γ release assay, QuantiFERON-TB (QFT test, has been introduced an alternative test for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI. Here, we compared the performance of QFT with tuberculin skin test (TST measured at two different cut-off points among primary health care work (HCW in Brazil.A cross-sectional study was carried out among HCWs in four Brazilian cities with a known history of high incidence of TB. Results of the QFT were compared to TST results based on both ≥5 mm and ≥10 mm as cut-off points.We enrolled 632 HCWs. When the cut-off value of ≥10 mm was used, agreement between QFT and TST was 69% (k = 0.31, and when the cut-off of ≥5 mm was chosen, the agreement was 57% (k = 0.22. We investigated possible factors of discordance of TST vs QFT. Compared to the TST-/QFT- group, risk factors for discordance in the TST+/QFT- group with TST cut-off of ≥5 mm included age between 41-45 years [OR = 2.70; CI 95%: 1.32-5.51] and 46-64 years [OR = 2.04; CI 95%: 1.05-3.93], BCG scar [OR = 2.72; CI 95%: 1.40-5.25], and having worked only in primary health care [OR = 2.30; CI 95%: 1.09-4.86]. On the other hand, for the cut-off of ≥10 mm, BCG scar [OR = 2.26; CI 95%: 1.03-4.91], being a household contact of a TB patient [OR = 1.72; CI 95%: 1.01-2.92] and having had a previous TST [OR = 1.66; CI 95%: 1.05-2.62], were significantly associated with the TST+/QFT- group. No statistically significant associations were found among the TST-/QFT+ discordant group with either TST cut-off value.Although we identified BCG vaccination to contribute to the discordance at both TST cut-off measures, the current Brazilian recommendation for the initiation of LTBI treatment, based on information gathered from medical history, TST, chest radiograph and physical examination, should not be changed.

Comparison of interferon-γ release assay to two cut-off points of tuberculin skin test to detect latent Mycobacterium tuberculosis infection in primary health care workers.

Science.gov (United States)

de Souza, Fernanda Mattos; do Prado, Thiago Nascimento; Pinheiro, Jair dos Santos; Peres, Renata Lyrio; Lacerda, Thamy Carvalho; Loureiro, Rafaela Borge; Carvalho, Jose Américo; Fregona, Geisa; Dias, Elias Santos; Cosme, Lorrayne Beliqui; Rodrigues, Rodrigo Ribeiro; Riley, Lee Wood; Maciel, Ethel Leonor Noia

2014-01-01

An interferon-γ release assay, QuantiFERON-TB (QFT) test, has been introduced an alternative test for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI). Here, we compared the performance of QFT with tuberculin skin test (TST) measured at two different cut-off points among primary health care work (HCW) in Brazil. A cross-sectional study was carried out among HCWs in four Brazilian cities with a known history of high incidence of TB. Results of the QFT were compared to TST results based on both ≥5 mm and ≥10 mm as cut-off points. We enrolled 632 HCWs. When the cut-off value of ≥10 mm was used, agreement between QFT and TST was 69% (k = 0.31), and when the cut-off of ≥5 mm was chosen, the agreement was 57% (k = 0.22). We investigated possible factors of discordance of TST vs QFT. Compared to the TST-/QFT- group, risk factors for discordance in the TST+/QFT- group with TST cut-off of ≥5 mm included age between 41-45 years [OR = 2.70; CI 95%: 1.32-5.51] and 46-64 years [OR = 2.04; CI 95%: 1.05-3.93], BCG scar [OR = 2.72; CI 95%: 1.40-5.25], and having worked only in primary health care [OR = 2.30; CI 95%: 1.09-4.86]. On the other hand, for the cut-off of ≥10 mm, BCG scar [OR = 2.26; CI 95%: 1.03-4.91], being a household contact of a TB patient [OR = 1.72; CI 95%: 1.01-2.92] and having had a previous TST [OR = 1.66; CI 95%: 1.05-2.62], were significantly associated with the TST+/QFT- group. No statistically significant associations were found among the TST-/QFT+ discordant group with either TST cut-off value. Although we identified BCG vaccination to contribute to the discordance at both TST cut-off measures, the current Brazilian recommendation for the initiation of LTBI treatment, based on information gathered from medical history, TST, chest radiograph and physical examination, should not be changed.

Correlation between Surface Roughness Characteristics in CO2 Laser Cutting of Mild Steel

Directory of Open Access Journals (Sweden)

M. Radovanović

2012-12-01

Full Text Available CO2 laser oxygen cutting of mild steel is widely used industrial application. Cut surface quality is a very important characteristic of laser cutting that ensures an advantage over other contour cutting processes. In this paper mathematical models for estimating characteristics of surface quality such as average surface roughness and ten-point mean roughness in CO2 laser cutting of mild steel based on laser cutting parameters were developed. Empirical models were developed using artificial neural networks and experimental data collected. Taguchi’s orthogonal array was implemented for experimental plan. From the analysis of the developed mathematical models it was observed that functional dependence between laser cutting parameters, their interactions and surface roughness characteristics is complex and non-linear. It was also observed that there exist region of minimal average surface roughness to ten-point mean roughness ratio. The relationship between average surface roughness and ten-point mean roughness was found to be nonlinear and can be expressed with a second degree polynomial.

Maxwell Strata and Cut Locus in the Sub-Riemannian Problem on the Engel Group

Science.gov (United States)

Ardentov, Andrei A.; Sachkov, Yuri L.

2017-12-01

We consider the nilpotent left-invariant sub-Riemannian structure on the Engel group. This structure gives a fundamental local approximation of a generic rank 2 sub-Riemannian structure on a 4-manifold near a generic point (in particular, of the kinematic models of a car with a trailer). On the other hand, this is the simplest sub-Riemannian structure of step three. We describe the global structure of the cut locus (the set of points where geodesics lose their global optimality), the Maxwell set (the set of points that admit more than one minimizer), and the intersection of the cut locus with the caustic (the set of conjugate points along all geodesics). The group of symmetries of the cut locus is described: it is generated by a one-parameter group of dilations R+ and a discrete group of reflections Z2 × Z2 × Z2. The cut locus admits a stratification with 6 three-dimensional strata, 12 two-dimensional strata, and 2 one-dimensional strata. Three-dimensional strata of the cut locus are Maxwell strata of multiplicity 2 (for each point there are 2 minimizers). Two-dimensional strata of the cut locus consist of conjugate points. Finally, one-dimensional strata are Maxwell strata of infinite multiplicity, they consist of conjugate points as well. Projections of sub-Riemannian geodesics to the 2-dimensional plane of the distribution are Euler elasticae. For each point of the cut locus, we describe the Euler elasticae corresponding to minimizers coming to this point. Finally, we describe the structure of the optimal synthesis, i. e., the set of minimizers for each terminal point in the Engel group.

Age, sex and ethnic differences in the prevalence of underweight and overweight, defined by using the CDC and IOTF cut points in Asian culture

Science.gov (United States)

No nationally representative data from middle- and low-income countries have been analyzed to compare the prevalence of underweight and overweight, defined by using the Centers for Disease Control and Prevention (CDC), and the International Obesity TaskForce (IOTF) body mass index cut points. To exa...

Development of lathe tool dynamometer and finding cutting forces using negative and positive rake angle cutting tool

International Nuclear Information System (INIS)

Zeb, M.A.; Irfan, M.A.

2005-01-01

Most output parameters in machining, such as cutting forces, temperatures, strains and the work-hardening of the chip material, are directly related to the chip formation process. The characteristics of machining processes can be well understood if the forces and strains during chip formation are known. In this research a lathe tool dynamometer was used to measure cutting forces involved in machining of Steel 1045 and Aluminum 2219 T62. High Speed Steel (HSS), cutting tools with positive and negative rake angles were used. It was observed that more cutting forces are experienced by the cutting tool with positive rake angle as compared to the forces experienced by the cutting tool with negative rake angle. For steel 1045 the cutting forces using positive rake angle cutting tool were much higher. This suggested that for harder materials using a negative rake angle is more suitable for cutting. (author)

Radioactive wear measurements of cutting tools made of metal in cutting aluminium alloys

International Nuclear Information System (INIS)

Frevert, E.

1977-01-01

The possibility of making quick checkings of the inhomogeneities of turning materials with radioactive wear measurements has been tested. After activation analysis of the long-lived radioisotopes of cutting tools made of hard metal a method for loss-free collection of the turnings has been developed. The detection limit of the abrasion is about 10 -8 g, the measuring times are 5-10 minutes. Special radiation protection measures are not necessary. An analysis of the abrasion showed that at the beginning of cutting the amount of cobalt is 6 times higher than in the normal composition of the used cutting tools. (author)

Numerical simulation of rock cutting using 2D AUTODYN

International Nuclear Information System (INIS)

Woldemichael, D E; Rani, A M Abdul; Lemma, T A; Altaf, K

2015-01-01

In a drilling process for oil and gas exploration, understanding of the interaction between the cutting tool and the rock is important for optimization of the drilling process using polycrystalline diamond compact (PDC) cutters. In this study the finite element method in ANSYS AUTODYN-2D is used to simulate the dynamics of cutter rock interaction, rock failure, and fragmentation. A two-dimensional single PDC cutter and rock model were used to simulate the orthogonal cutting process and to investigate the effect of different parameters such as depth of cut, and back rake angle on two types of rocks (sandstone and limestone). In the simulation, the cutting tool was dragged against stationary rock at predetermined linear velocity and the depth of cut (1,2, and 3 mm) and the back rake angles(-10°, 0°, and +10°) were varied. The simulation result shows that the +10° back rake angle results in higher rate of penetration (ROP). Increasing depth of cut leads to higher ROP at the cost of higher cutting force. (paper)

Development of laser cutting method for stainless steel liner

International Nuclear Information System (INIS)

Ishihara, Satoshi; Takahata, Masato; Wignarajah, Sivakumaran; Kamata, Hirofumi

2007-01-01

The present work is an attempt to develop a laser cutting method for cutting and removing stainless steel liners from concrete walls and floors in nuclear facilities. The effect of basic laser cutting parameters such as energy, cutting speed, assist gas flow etc. were first studied through cutting experiments on mock-up concrete specimens lined with 3mm thick stainless steel sheets using a 1kW Nd:YAG laser. These initial studies were followed by further studies on the effect of unevenness of the liner surface and on a new method of confining contamination during the cutting process using a sliding evacuation hood attached to the laser cutting head. The results showed that laser cutting is superior to other conventional cutting methods from the point of view of safety from radioactivity and work efficiency when cutting contaminated stainless steel liners. (author)

Development of YAG laser cutting system for decommissioning nuclear equipments

International Nuclear Information System (INIS)

Kasai, Takeshi; Nitta, Kazuhiko; Hosoda, Hiroshi.

1995-01-01

Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. As a result, the stainless steel plate with a thickness of 22mm could be cut by using an optical fiber which can flexibly propagate laser power, and possibility of application of this laser cutting system to decommissioning nuclear equipments was verified. (author)

Development of YAG laser cutting system for decommissioning nuclear equipments

Energy Technology Data Exchange (ETDEWEB)

Kasai, Takeshi [Fuji Electric Co. Research and Development Ltd., Yokosuka, Kanagawa (Japan); Nitta, Kazuhiko; Hosoda, Hiroshi

1995-07-01

Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. As a result, the stainless steel plate with a thickness of 22mm could be cut by using an optical fiber which can flexibly propagate laser power, and possibility of application of this laser cutting system to decommissioning nuclear equipments was verified. (author).

Bronchodilator response cut-off points and FEV 0.75 reference values for spirometry in preschoolers.

Science.gov (United States)

Burity, Edjane Figueiredo; Pereira, Carlos Alberto de Castro; Jones, Marcus Herbert; Sayão, Larissa Bouwman; Andrade, Armèle Dornelas de; Britto, Murilo Carlos Amorim de

2016-01-01

To determine the cut-off points for FEV1, FEV0.75, FEV0.5, and FEF25-75% bronchodilator responses in healthy preschool children and to generate reference values for FEV0.75. This was a cross-sectional community-based study involving children 3-5 years of age. Healthy preschool children were selected by a standardized questionnaire. Spirometry was performed before and after bronchodilator use. The cut-off point of the response was defined as the 95th percentile of the change in each parameter. We recruited 266 children, 160 (60%) of whom were able to perform acceptable, reproducible expiratory maneuvers before and after bronchodilator use. The mean age and height were 57.78 ± 7.86 months and 106.56 ± 6.43 cm, respectively. The success rate for FEV0.5 was 35%, 68%, and 70% in the 3-, 4-, and 5-year-olds, respectively. The 95th percentile of the change in the percentage of the predicted value in response to bronchodilator use was 11.6%, 16.0%, 8.5%, and 35.5% for FEV1, FEV0.75, FEV0.5, and FEF25-75%, respectively. Our results provide cut-off points for bronchodilator responsiveness for FEV1, FEV0.75, FEV0.5, and FEF25-75% in healthy preschool children. In addition, we proposed gender-specific reference equations for FEV0.75. Our findings could improve the physiological assessment of respiratory function in preschool children. Determinar os pontos de corte de resposta ao broncodilatador do VEF1, VEF0,75, VEF0,5 e FEF25-75% em crianças pré-escolares saudáveis e gerar valores de referência para o VEF0,75. Foi realizado um estudo transversal de base comunitária em crianças de 3-5 anos de idade. Pré-escolares saudáveis foram selecionados por um questionário padronizado. Foi realizada espirometria antes e depois do uso de broncodilatador. Foram definidos os pontos de corte dessa resposta como o percentil 95 de variação em cada parâmetro. Foram recrutadas 266 crianças, e 160 (60,0%) foram capazes de gerar manobras expiratórias aceitáveis e reprodut

Sharper angle, higher risk? The effect of cutting angle on knee mechanics in invasion sport athletes

NARCIS (Netherlands)

Schreurs, Mervin J.; Benjaminse, Anne; Lemmink, Koen A. P. M.

2017-01-01

Introduction: Cutting is an important skill in team-sports, but unfortunately is also related to non-contact ACL injuries. The purpose was to examine knee kinetics and kinematics at different cutting angles. Material and methods: 13 males and 16 females performed cuts at different angles (45°, 90°,

SurfCut: Surfaces of Minimal Paths From Topological Structures

KAUST Repository

Algarni, Marei Saeed Mohammed

2018-03-05

We present SurfCut, an algorithm for extracting a smooth, simple surface with an unknown 3D curve boundary from a noisy image and a seed point. Our method is built on the novel observation that certain ridge curves of a function defined on a front propagated using the Fast Marching algorithm lie on the surface. Our method extracts and cuts these ridges to form the surface boundary. Our surface extraction algorithm is built on the novel observation that the surface lies in a valley of the distance from Fast Marching. We show that the resulting surface is a collection of minimal paths. Using the framework of cubical complexes and Morse theory, we design algorithms to extract these critical structures robustly. Experiments on three 3D datasets show the robustness of our method, and that it achieves higher accuracy with lower computational cost than state-of-the-art.

SurfCut: Surfaces of Minimal Paths From Topological Structures

KAUST Repository

Algarni, Marei Saeed Mohammed

2017-04-30

We present SurfCut, an algorithm for extracting a smooth, simple surface with an unknown 3D curve boundary from a noisy 3D image and a seed point. Our method is built on the novel observation that certain ridge curves of a function defined on a front propagated using the Fast Marching algorithm lie on the surface. Our method extracts and cuts these ridges to form the surface boundary. Our surface extraction algorithm is built on the novel observation that the surface lies in a valley of the distance from Fast Marching. We show that the resulting surface is a collection of minimal paths. Using the framework of cubical complexes and Morse theory, we design algorithms to extract these critical structures robustly. Experiments on three 3D datasets show the robustness of our method, and that it achieves higher accuracy with lower computational cost than state-of-the-art.

SurfCut: Surfaces of Minimal Paths From Topological Structures

KAUST Repository

Algarni, Marei Saeed Mohammed; Sundaramoorthi, Ganesh

2018-01-01

We present SurfCut, an algorithm for extracting a smooth, simple surface with an unknown 3D curve boundary from a noisy image and a seed point. Our method is built on the novel observation that certain ridge curves of a function defined on a front propagated using the Fast Marching algorithm lie on the surface. Our method extracts and cuts these ridges to form the surface boundary. Our surface extraction algorithm is built on the novel observation that the surface lies in a valley of the distance from Fast Marching. We show that the resulting surface is a collection of minimal paths. Using the framework of cubical complexes and Morse theory, we design algorithms to extract these critical structures robustly. Experiments on three 3D datasets show the robustness of our method, and that it achieves higher accuracy with lower computational cost than state-of-the-art.

Power-law scaling of extreme dynamics near higher-order exceptional points

Science.gov (United States)

Zhong, Q.; Christodoulides, D. N.; Khajavikhan, M.; Makris, K. G.; El-Ganainy, R.

2018-02-01

We investigate the extreme dynamics of non-Hermitian systems near higher-order exceptional points in photonic networks constructed using the bosonic algebra method. We show that strong power oscillations for certain initial conditions can occur as a result of the peculiar eigenspace geometry and its dimensionality collapse near these singularities. By using complementary numerical and analytical approaches, we show that, in the parity-time (PT ) phase near exceptional points, the logarithm of the maximum optical power amplification scales linearly with the order of the exceptional point. We focus in our discussion on photonic systems, but we note that our results apply to other physical systems as well.

Effects of different cutting centers on LASIK surgery in myopic patients

Directory of Open Access Journals (Sweden)

Yan-Wei Liu

2017-07-01

Full Text Available AIM:To investigate the effect of different cutting centers on the visual acuity, refractive diopter and visual quality of patients undergoing laser assisted in situ keratomileusis(LASIK. METHODS: A total of 80 patients(160 eyeswith myopia treated by elective LASIK were divided into two groups. Thirty-six cases(72 eyeswith visual axis corneal reflection point(VACRPas the cutting center were included into the VACRP group while 44 cases(88 eyeswith pupil center(PCas the cutting center were included into the PC group. The uncorrected visual acuity(UCVA, the best corrected visual acuity(BCVA, refractive diopter, corneal aberration \\〖total corneal and anterior corneal surface higher-order aberrations(HOA, spherical aberration(Z40, vertical coma(Z3-1, horizontal coma(totZ31and offset of cutting centers were determined before surgery and 1mo after surgery. RESULTS: There was no difference in the probability of UCVA ≥ 0.1, BCVA and refractive diopter between the two groups at 1mo after surgery(P>0.05. The astigmatism and cutting center deviation of VACRP group were lower than those of PC group(P40, totZ3-1, totZ31, froHOA, froZ3-1、froZ31 and froZ40 were lower in VACRP group than PC group at 1mo after surgery(PCONCLUSION: The UCVA of patients treated with both cutting centers for LASIK is good but VACRP has more advantages in reducing the offset of cutting center and improving postoperative visual quality.

Laser circular cutting of Kevlar sheets: Analysis of thermal stress filed and assessment of cutting geometry

Science.gov (United States)

Yilbas, B. S.; Akhtar, S. S.; Karatas, C.

2017-11-01

A Kevlar laminate has negative thermal expansion coefficient, which makes it difficult to machine at room temperaures using the conventional cutting tools. Contararily, laser machining of a Kevlar laminate provides advantages over the conventional methods because of the non-mechanical contact between the cutting tool and the workpiece. In the present study, laser circular cutting of Kevlar laminate is considered. The experiment is carried out to examine and evaluate the cutting sections. Temperature and stress fields formed in the cutting section are simulated in line with the experimental study. The influence of hole diameters on temperature and stress fields are investigated incorporating two different hole diameters. It is found that the Kevlar laminate cutting section is free from large size asperities such as large scale sideways burnings and attachemnt of charred residues. The maximum temperature along the cutting circumference remains higher for the large diameter hole than that of the small diameter hole. Temperature decay is sharp around the cutting section in the region where the cutting terminates. This, in turn, results in high temperature gradients and the thermal strain in the cutting region. von Mises stress remains high in the region where temperature gradients are high. von Mises stress follows similar to the trend of temperature decay around the cutting edges.

Determination of sensitivity, specificity and cut off point of visual- Motor Bender Gestalt Test in the diagnosis of traumatic brain injury

Directory of Open Access Journals (Sweden)

tayebeh Rezaie nasab

2013-02-01

Results: In this study, cut-off point was calculated as 6.5%, sensitivity as 55.8%, characteristic as 81.2%, and the area under the Roc curve as 0.69. Moreover, positive predictive value, negative predictive value and efficiency were 95.08%, 22.03%, and 59.17%, respectively. Conclusion: Results of this study revealed that Bender Gestalt Test is relatively weak in diagnosis of mild TBI. Hence, its characteristic is high and it was successful in diagnosing healthy individuals.

Investigation of Physical Phenomena and Cutting Efficiency for Laser Cutting on Anode for Li-Ion Batteries

Directory of Open Access Journals (Sweden)

Dongkyoung Lee

2018-02-01

Full Text Available Lithium-ion batteries have a higher energy density than other secondary batteries. Among the lithium-ion battery manufacturing process, electrode cutting is one of the most important processes since poor cut quality leads to performance degradation, separator protrusion, and local electric stress concentration. This may, eventually, lead to malfunction of lithium-ion batteries or explosion. The current mechanical cutting technology uses a contact process and this may lead to process instability. Furthermore, there are additional costs if the tools and cell design are changed. To solve these issues, laser cutting has been used. Conventional dependent parameters have limitations in investigating and explaining many physical phenomena during the laser cutting of electrodes. Therefore, this study proposes specific widths such as melting, top, and kerf width. Moreover, the relationship between laser parameters and multiphysical phenomena with the proposed widths are investigated. Five types of classification with regard to physical phenomena are presented and explained with SEM images. Cutting efficiency is estimated with the proposed widths. The proposed specific cutting widths, five types of geometrical classification, and cutting efficiency can be used as standardized parameters to evaluate the cutting quality.

Development of liner cutting method for stainless steel liner

International Nuclear Information System (INIS)

Takahata, Masato; Wignarajah, Sivakmaran; Kamata, Hirofumi

2005-01-01

The present work is an attempt to develop a laser cutting method for cutting and removing stainless steel liners from concrete walls and floors in cells and fuel storage pools of nuclear facilities. The effects of basic laser cutting parameters such as cutting speed, assist gas flow etc. were first studied applying a 1 kW Nd:YAG laser to mock up concrete specimens lined with 3 mm thick stainless steel sheets. These initial studies were followed by studies on the effect of unevenness of the liner surface and on methods of confining contamination during the cutting process. The results showed that laser cutting is superior to other conventional cutting methods from the point of view of safety from radioactivity and work efficiency when cutting contaminated stainless steel liners. In addition to the above results, this paper describes the design outline of a laser cutting system for cutting stainless liners at site and evaluates its merit and cost performance. (author)

Estimation of the laser cutting operating cost by support vector regression methodology

Science.gov (United States)

Jović, Srđan; Radović, Aleksandar; Šarkoćević, Živče; Petković, Dalibor; Alizamir, Meysam

2016-09-01

Laser cutting is a popular manufacturing process utilized to cut various types of materials economically. The operating cost is affected by laser power, cutting speed, assist gas pressure, nozzle diameter and focus point position as well as the workpiece material. In this article, the process factors investigated were: laser power, cutting speed, air pressure and focal point position. The aim of this work is to relate the operating cost to the process parameters mentioned above. CO2 laser cutting of stainless steel of medical grade AISI316L has been investigated. The main goal was to analyze the operating cost through the laser power, cutting speed, air pressure, focal point position and material thickness. Since the laser operating cost is a complex, non-linear task, soft computing optimization algorithms can be used. Intelligent soft computing scheme support vector regression (SVR) was implemented. The performance of the proposed estimator was confirmed with the simulation results. The SVR results are then compared with artificial neural network and genetic programing. According to the results, a greater improvement in estimation accuracy can be achieved through the SVR compared to other soft computing methodologies. The new optimization methods benefit from the soft computing capabilities of global optimization and multiobjective optimization rather than choosing a starting point by trial and error and combining multiple criteria into a single criterion.

Three Point Functions in Higher Spin AdS3 Holography with 1/N Corrections

Directory of Open Access Journals (Sweden)

Yasuaki Hikida

2017-10-01

Full Text Available We examine three point functions with two scalar operators and a higher spin current in 2d W N minimal model to the next non-trivial order in 1 / N expansion. The minimal model was proposed to be dual to a 3d higher spin gauge theory, and 1 / N corrections should be interpreted as quantum effects in the dual gravity theory. We develop a simple and systematic method to obtain three point functions by decomposing four point functions of scalar operators with Virasoro conformal blocks. Applying the method, we reproduce known results at the leading order in 1 / N and obtain new ones at the next leading order. As confirmation, we check that our results satisfy relations among three point functions conjectured before.

Biochemical aspects of single-node cuttings of Ricinodendron ...

African Journals Online (AJOL)

NEHEMIE

2013-03-06

Mar 6, 2013 ... changes, basal single-node leafy cuttings were treated with different .... with local material and providing an internal irradiance of 20 to 32%. ..... higher in rooting cutting during the initiation phase). Phenolics ... Chrysanthemum cuttings as affected by nitrogen supply and cold- storage. Ann. Bot. 85:697-701.

The optimization of the cutting process of diamonds with a YAG laser

Directory of Open Access Journals (Sweden)

A. J. Lubbe

1993-07-01

Full Text Available A laser cannot, as generally assumed by the layman, cut right through a diamond with a single cut. A couple of hundred cuts may be necessary to "chip carve" through a diamond. There are several parameters, for example cutting speed, focus point, overlapping of cuts, etc., that influence the cutting process. With a view to optimizing the cutting process, laser cuts in diamonds were studied in a systematic way with the aid of an electron microscope. The method, technique and the results of the research are discussed in this article.

Optical Cutting Interruption Sensor for Fiber Lasers

Directory of Open Access Journals (Sweden)

Benedikt Adelmann

2015-09-01

Full Text Available We report on an optical sensor system attached to a 4 kW fiber laser cutting machine to detect cutting interruptions. The sensor records the thermal radiation from the process zone with a modified ring mirror and optical filter arrangement, which is placed between the cutting head and the collimator. The process radiation is sensed by a Si and InGaAs diode combination with the detected signals being digitalized with 20 kHz. To demonstrate the function of the sensor, signals arising during fusion cutting of 1 mm stainless steel and mild steel with and without cutting interruptions are evaluated and typical signatures derived. In the recorded signals the piercing process, the laser switch on and switch off point and waiting period are clearly resolved. To identify the cutting interruption, the signals of both Si and InGaAs diodes are high pass filtered and the signal fluctuation ranges being subsequently calculated. Introducing a correction factor, we identify that only in case of a cutting interruption the fluctuation range of the Si diode exceeds the InGaAs diode. This characteristic signature was successfully used to detect 80 cutting interruptions of 83 incomplete cuts (alpha error 3.6% and system recorded no cutting interruption from 110 faultless cuts (beta error of 0. This particularly high detection rate in combination with the easy integration of the sensor, highlight its potential for cutting interruption detection in industrial applications.

Cutting Temperature Investigation of AISI H13 in High Speed End Milling

Directory of Open Access Journals (Sweden)

Muhammad Riza

2016-10-01

Full Text Available Heat produced at the tool-chip interface during high speed milling operations have been known as a significant factor that affect to tool life and workpiece geometry or properties. This paper aims to investigate cutting temperature behaviours of AISI H13 (48 HRC under high speed machining circumstances during pocketing. The experiments were conducted on CNC vertical machining centre by using PVD coated carbide insert. Milling processes were done at cutting speeds 150, 200 and 250 m/min and feed rate were 0.05, 0.1 and 0.15 mm/tooth. Depths of cut applied were 0.1, 0.15 and 0.2 mm. Tool path method applied in this experiment was contour in. Results presented in this paper indicate that by increasing cutting speed the cutting temperature is lower than low cutting speed. However, by decreasing feed rate leads to cutting temperature low. Cutting temperature phenomena at the corner of pocket milling were also investigated. The phenomena showed that cutting temperature tends to decrease a moment when cutter comes to the corner of pocket and turning point of tool path and increase extremely a moment before leaving the corner and turning point.

A higher sink competitiveness of the rooting zone and invertases are involved in dark stimulation of adventitious root formation in Petunia hybrida cuttings.

Science.gov (United States)

Klopotek, Yvonne; Franken, Philipp; Klaering, Hans-Peter; Fischer, Kerstin; Hause, Bettina; Hajirezaei, Mohammad-Reza; Druege, Uwe

2016-02-01

The contribution of carbon assimilation and allocation and of invertases to the stimulation of adventitious root formation in response to a dark pre-exposure of petunia cuttings was investigated, considering the rooting zone (stem base) and the shoot apex as competing sinks. Dark exposure had no effect on photosynthesis and dark respiration during the subsequent light period, but promoted dry matter partitioning to the roots. Under darkness, higher activities of cytosolic and vacuolar invertases were maintained in both tissues when compared to cuttings under light. This was partially associated with higher RNA levels of respective genes. However, activity of cell wall invertases and transcript levels of one cell wall invertase isogene increased specifically in the stem base during the first two days after cutting excision under both light and darkness. During five days after excision, RNA accumulation of four invertase genes indicated preferential expression in the stem base compared to the apex. Darkness shifted the balance of expression of one cytosolic and two vacuolar invertase genes towards the stem base. The results indicate that dark exposure before planting enhances the carbon sink competitiveness of the rooting zone and that expression and activity of invertases contribute to the shift in carbon allocation. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Plasma arc cutting: Microstructural modifications of hafnium cathodes during first cycles

Energy Technology Data Exchange (ETDEWEB)

Rotundo, F., E-mail: fabio.rotundo@unibo.it [Dept. of Mechanical Engineering (DIEM), Alma Mater Studiorum, Universita di Bologna, Via Saragozza 8, 40123 Bologna (Italy); Martini, C.; Chiavari, C.; Ceschini, L. [Dept. of Metals Science, Electrochemistry and Chemical Techniques (SMETEC), Alma Mater Studiorum, Universita di Bologna, Viale Risorgimento 4, 40136 Bologna (Italy); Concetti, A.; Ghedini, E.; Colombo, V. [Dept. of Mechanical Engineering (DIEM), Alma Mater Studiorum, Universita di Bologna, Via Saragozza 8, 40123 Bologna (Italy); Dallavalle, S. [Cebora S.p.A., Via Andrea Costa 24, 40057 Cadriano di Granarolo (Italy)

2012-06-15

In the present work, the microstructural modifications of the Hf insert in plasma arc cutting (PAC) electrodes operating at 250 A were experimentally investigated during first cycles, in order to understand those phenomena occurring on and under the Hf emissive surface and involved in the electrode erosion process. Standard electrodes were subjected to an increasing number of cutting cycles (CCs) on mild steel plates in realistic operative conditions, with oxygen/air as plasma/shield gas. Microstructural analysis was performed for each electrode at different erosion stages by means of scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and Raman spectroscopy. Electrodes cross sections were also observed by means of optical microscopy (both in bright field and in reflected polarised light) after chemical etching. In the insert, three typical zones were found after cutting: monoclinic HfO{sub 2} layer; thermally-modified transition zone with O{sub 2}-Hf solid solution; unmodified Hf. The erosion cavity and the oxide layer thickness increase with the number of cutting cycles. Macrocracking was observed in the oxide layer, while microcracking and grain growth were detected in the remelted Hf. Moreover, detachment was found at the Hf/Cu interface. Based on thermodynamics and kinetics of the Hf high temperature oxidation, conclusions can be drawn on the erosion mechanism involved. - Highlights: Black-Right-Pointing-Pointer Hf microstructural modifications in cathodes after plasma arc cutting cycles investigated. Black-Right-Pointing-Pointer 3 zones identified after cutting: HfO{sub 2} layer; remelted zone with O{sub 2}-Hf solid solution; unmodified Hf. Black-Right-Pointing-Pointer Hf-based ejections both in arc-on and arc-off phases; erosion cavity deepens with cutting cycles. Black-Right-Pointing-Pointer Detachment at the Hf/Cu interfaces, worsening heat dissipation and oxidation/erosion phenomena. Black-Right-Pointing-Pointer The use

Correlation methods in cutting arcs

Energy Technology Data Exchange (ETDEWEB)

Prevosto, L; Kelly, H, E-mail: prevosto@waycom.com.ar [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Universidad Tecnologica Nacional, Regional Venado Tuerto, Laprida 651, Venado Tuerto (2600), Santa Fe (Argentina)

2011-05-01

The present work applies similarity theory to the plasma emanating from transferred arc, gas-vortex stabilized plasma cutting torches, to analyze the existing correlation between the arc temperature and the physical parameters of such torches. It has been found that the enthalpy number significantly influence the temperature of the electric arc. The obtained correlation shows an average deviation of 3% from the temperature data points. Such correlation can be used, for instance, to predict changes in the peak value of the arc temperature at the nozzle exit of a geometrically similar cutting torch due to changes in its operation parameters.

Correlation methods in cutting arcs

International Nuclear Information System (INIS)

Prevosto, L; Kelly, H

2011-01-01

The present work applies similarity theory to the plasma emanating from transferred arc, gas-vortex stabilized plasma cutting torches, to analyze the existing correlation between the arc temperature and the physical parameters of such torches. It has been found that the enthalpy number significantly influence the temperature of the electric arc. The obtained correlation shows an average deviation of 3% from the temperature data points. Such correlation can be used, for instance, to predict changes in the peak value of the arc temperature at the nozzle exit of a geometrically similar cutting torch due to changes in its operation parameters.

Multi-cut solutions in Chern-Simons matrix models

Science.gov (United States)

Morita, Takeshi; Sugiyama, Kento

2018-04-01

We elaborate the Chern-Simons (CS) matrix models at large N. The saddle point equations of these matrix models have a curious structure which cannot be seen in the ordinary one matrix models. Thanks to this structure, an infinite number of multi-cut solutions exist in the CS matrix models. Particularly we exactly derive the two-cut solutions at finite 't Hooft coupling in the pure CS matrix model. In the ABJM matrix model, we argue that some of multi-cut solutions might be interpreted as a condensation of the D2-brane instantons.

Percentage of free prostate-specific antigen (PSA) is a useful method in deciding to perform prostate biopsy with higher core numbers in patients with low PSA cut-off values.

Science.gov (United States)

Yilmaz, Hasan; Ciftci, Seyfettin; Yavuz, Ufuk; Ustuner, Murat; Saribacak, Ali; Dillioglugil, Ozdal

2015-06-01

The aim of this study was to evaluate the predictive role of percentage of free prostate-specific antigen (%fPSA) cut-points in prostate cancer (PCa) detection in patients with total PSA (tPSA) levels between 2.5 ng/mL and 10.0 ng/mL. In total, 1321 consecutive initial transrectal ultrasound (TRUS)-guided 12-core biopsies performed between 2005 and 2011 were evaluated retrospectively. Benign pathologies, high-grade prostatic intraepithelial neoplasia, and atypical small acinary proliferations were categorized as noncancerous (benign), and prostate adenocarcinomas were categorized as cancerous (malignant). The patients were categorized according to: Catalona's published %fPSA categories ( 25%); digital rectal examination (DRE) results [benign (negative) or suspicious of malignancy (positive)]. There was a significant relationship between the %fPSA cut-points and detection of PCa in DRE-negative patients. The presence of a 10% cut-point increased the probability of PCa threefold. The %fPSA was significantly more related to PCa than the tPSA value in receiver operating characteristic (ROC) curve analyses (p = 0.001). Based on our findings, a lower %fPSA, especially <10%, is an important parameter when deciding whether to perform a biopsy on patients with a tPSA between 2.5 ng/mL and 10 ng/mL. Copyright © 2015. Published by Elsevier Taiwan.

Investigating the CO2 laser cutting parameters of MDF wood composite material

OpenAIRE

Eltawahni, Hayat; Olabi, Abdul-Ghani; Benyounis, Khaled

2011-01-01

Laser cutting of medium density fibreboard (MDF) is a complicated process and the selection of the process parameters combinations is essential to get the highest quality of the cut section. This paper presents laser cutting of MDF based on design of experiments (DOE). CO2 laser was used to cut three thicknesses 4, 6 and 9 mm of MDF panels. The process factors investigated are: laser power, cutting speed, air pressure and focal point position. In this work, cutting quality was evaluated by me...

An Equipment to Measure the Freezing Point of Soils under Higher Pressure

Science.gov (United States)

Wang, Dayan; Guan, Hui; Wen, Zhi; Ma, Wei

2014-05-01

Soil freezing point is the highest temperature at which ice can be presented in the system and soil can be referred to as frozen. The freezing temperature of soil is an important parameter for solving many practical problems in civil engineering, such as evaluation of soil freezing depth, prediction of soil heaving, force of soil suction, etc. However, as the freezing temperature is always affected by many factors like soil particle size, mineral composition, water content and the external pressure endured by soils, to measure soil freezing point is a rather difficult task until now, not to mention the soil suffering higher pressure. But recently, with the artificial freezing technology widely used in the excavation of deep underground space, the frozen wall thickness is a key factor to impact the security and stability of deep frozen wall. To determine the freeze wall thickness, the location of the freezing front must be determined firstly, which will deal with the determination of the soil freezing temperature. So how to measure the freezing temperature of soil suffering higher pressure is an important problem to be solved. This paper will introduce an equipment which was developed lately by State Key Laboratory of Frozen Soil Engineering to measure the freezing-point of soils under higher pressure. The equipment is consisted of cooling and keeping temperature system, temperature sensor and data collection system. By cooling and keeping temperature system, not only can we make the higher pressure soil sample's temperature drop to a discretionary minus temperature, but also keep it and reduce the heat exchange of soil sample with the outside. The temperature sensor is the key part to our measurement, which is featured by high precision and high sensitivity, what is more important is that the temperature sensor can work in a higher pressure condition. Moreover, the major benefit of this equipment is that the soil specimen's loads can be loaded by any microcomputer

Human variation and body mass index: a review of the universality of BMI cut-offs, gender and urban-rural differences, and secular changes.

Science.gov (United States)

Mascie-Taylor, C G Nicholas; Goto, Rie

2007-03-01

Use of BMI as a surrogate for body fat percentage is debatable and universal BMI cut-off points do not seem appropriate; lower cut-off points than currently recommended by WHO should be used in some populations, especially in Asia. The adult WHO BMI database indicates that, on average, women are more obese than men, while men are more likely to be pre-obese than women. Urban rates of overweight and obesity are generally higher than rural rates in both sexes. The trend in pre-obesity and obesity over time is generally upward, with very marked increases in the USA and UK in both sexes over the last 10 years.

Cutting

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Cutting KidsHealth / For Teens / Cutting What's in this article? ... Getting Help Print en español Cortarse What Is Cutting? Emma's mom first noticed the cuts when Emma ...

Respiration rate and ethylene production of fresh cut lettuce as affected by cutting grade

Directory of Open Access Journals (Sweden)

J. MARTÍNEZ

2008-12-01

Full Text Available For designing optimal polymeric films for modified atmosphere packaging of whole heads as well as for minimally fresh processed (fresh-cut Iceberg lettuce ‘Coolguard’, the effect of several cutting grades on respiration rate (RR and ethylene production at 5ºC was studied. According to common industrial practices cutting grades less than 0.5 cm, between 0.5 and 1 cm, and 2 cm length were selected. Results from four experiments were compared to those obtained for whole heads in which a homogenous range of 6 to 8 ml CO2 kg-1 h-1 in RR was found. Compared to whole heads, in fresh-cut lettuce the RR was 2-fold higher. The lowest cutting grade showed the highest respiration rate, and no significant differences in RR among lettuce pieces of intermediate and the highest grades were found. No ethylene production was detected in whole heads, while in minimally processed lettuce pieces only traces were found. For avoiding risks of anaerobic respiration and excessive CO2 levels within packages containing fresh-cut lettuce pieces lower than 0.5 cm length, films with relatively high O2 permeability like standard polypropylene or low-density polyethylene must be selected.;

Higher-order triangular spectral element method with optimized cubature points for seismic wavefield modeling

Energy Technology Data Exchange (ETDEWEB)

Liu, Youshan, E-mail: ysliu@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029 (China); Teng, Jiwen, E-mail: jwteng@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029 (China); Xu, Tao, E-mail: xutao@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029 (China); CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101 (China); Badal, José, E-mail: badal@unizar.es [Physics of the Earth, Sciences B, University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain)

2017-05-01

The mass-lumped method avoids the cost of inverting the mass matrix and simultaneously maintains spatial accuracy by adopting additional interior integration points, known as cubature points. To date, such points are only known analytically in tensor domains, such as quadrilateral or hexahedral elements. Thus, the diagonal-mass-matrix spectral element method (SEM) in non-tensor domains always relies on numerically computed interpolation points or quadrature points. However, only the cubature points for degrees 1 to 6 are known, which is the reason that we have developed a p-norm-based optimization algorithm to obtain higher-order cubature points. In this way, we obtain and tabulate new cubature points with all positive integration weights for degrees 7 to 9. The dispersion analysis illustrates that the dispersion relation determined from the new optimized cubature points is comparable to that of the mass and stiffness matrices obtained by exact integration. Simultaneously, the Lebesgue constant for the new optimized cubature points indicates its surprisingly good interpolation properties. As a result, such points provide both good interpolation properties and integration accuracy. The Courant–Friedrichs–Lewy (CFL) numbers are tabulated for the conventional Fekete-based triangular spectral element (TSEM), the TSEM with exact integration, and the optimized cubature-based TSEM (OTSEM). A complementary study demonstrates the spectral convergence of the OTSEM. A numerical example conducted on a half-space model demonstrates that the OTSEM improves the accuracy by approximately one order of magnitude compared to the conventional Fekete-based TSEM. In particular, the accuracy of the 7th-order OTSEM is even higher than that of the 14th-order Fekete-based TSEM. Furthermore, the OTSEM produces a result that can compete in accuracy with the quadrilateral SEM (QSEM). The high accuracy of the OTSEM is also tested with a non-flat topography model. In terms of computational

Higher-order triangular spectral element method with optimized cubature points for seismic wavefield modeling

International Nuclear Information System (INIS)

Liu, Youshan; Teng, Jiwen; Xu, Tao; Badal, José

2017-01-01

The mass-lumped method avoids the cost of inverting the mass matrix and simultaneously maintains spatial accuracy by adopting additional interior integration points, known as cubature points. To date, such points are only known analytically in tensor domains, such as quadrilateral or hexahedral elements. Thus, the diagonal-mass-matrix spectral element method (SEM) in non-tensor domains always relies on numerically computed interpolation points or quadrature points. However, only the cubature points for degrees 1 to 6 are known, which is the reason that we have developed a p-norm-based optimization algorithm to obtain higher-order cubature points. In this way, we obtain and tabulate new cubature points with all positive integration weights for degrees 7 to 9. The dispersion analysis illustrates that the dispersion relation determined from the new optimized cubature points is comparable to that of the mass and stiffness matrices obtained by exact integration. Simultaneously, the Lebesgue constant for the new optimized cubature points indicates its surprisingly good interpolation properties. As a result, such points provide both good interpolation properties and integration accuracy. The Courant–Friedrichs–Lewy (CFL) numbers are tabulated for the conventional Fekete-based triangular spectral element (TSEM), the TSEM with exact integration, and the optimized cubature-based TSEM (OTSEM). A complementary study demonstrates the spectral convergence of the OTSEM. A numerical example conducted on a half-space model demonstrates that the OTSEM improves the accuracy by approximately one order of magnitude compared to the conventional Fekete-based TSEM. In particular, the accuracy of the 7th-order OTSEM is even higher than that of the 14th-order Fekete-based TSEM. Furthermore, the OTSEM produces a result that can compete in accuracy with the quadrilateral SEM (QSEM). The high accuracy of the OTSEM is also tested with a non-flat topography model. In terms of computational

Objective assessment of subjective tinnitus through contralateral suppression of otoacoustic emissions by white noise; suggested cut-off points.

Science.gov (United States)

Riga, M; Komis, A; Maragkoudakis, P; Korres, G; Danielides, V

2016-12-01

Normative otoacoustic emission (OAE) suppression values are currently lacking and the role of cochlear efferent innervation in tinnitus is controversial. The aim of this study was to investigate the association between tinnitus and medial olivocochlear bundle (MOCB) malfunction. Potential suppression amplitude cut-off criteria that could differentiate participants with tinnitus from those without were sought. Mean suppression amplitudes of transient evoked OAEs and distortion product OAEs by contralateral white noise (50 dBSL) were recorded. Six mean suppression amplitudes criteria were validated as possible cut-off points. The population consisted of normal hearing (n = 78) or presbycusic adults (n = 19) with tinnitus or without (n = 28 and 13, respectively) chronic tinnitus (in total, n = 138 78 females/60males, aged 49 ± 14 years). Participants with mean suppression values lower than 0.5-1 dBSPL seem to present a high probability to report tinnitus (specificity 88-97%). On the other hand, participants with mean suppression values larger than 2-2.5dBSPL seem to present a high probability of the absence of tinnitus (sensitivity 87-99%). Correlations were stronger among participants with bilateral presence or absence of tinnitus. This study seem to confirm an association between tinnitus and low suppression amplitudes (<1 dBSPL), which might evolve into an objective examination tool, supplementary to conventional audiological testing.

MECHANISMS OF CUTTING BLADE WEAR AND THEIR INFLUENCE ON CUTTING ABILITY OF THE TOOL DURING MACHINING OF SPECIAL ALLOYS

Directory of Open Access Journals (Sweden)

Tomáš Zlámal

2016-09-01

Full Text Available With increased requirements for quality and shelf life of machined parts there is also a higher share of the use of material with specific properties that are identified by the term “superalloys”. These materials differ from common steels by mechanical and physical properties that cause their worse machinability. During machining of “superalloys” worse machinability has negative influence primarily on the amount of cutting edge wear, which shortens durability of the cutting tool. The goal of experimental activity shown in this contribution is to determine individual mechanisms of the cutting edge wear and their effects on the cutting ability during high speed machining of nickel superalloy. A specific exchangeable cutting insert made from cubic boric nitride was used for machining of the 625 material according to ASM 5666F. The criteria to evaluate cutting ability and durability of the cutting tool became selected parameters of surface integrity and quality of the machined surface.

Loop equations for multi-cut matrix models

International Nuclear Information System (INIS)

Akemann, G.

1995-03-01

The loop equation for the complex one-matrix model with a multi-cut structure is derived and solved in the planar limit. An iterative scheme for higher genus contributions to the free energy and the multi-loop correlators is presented for the two-cut model, where explicit results are given up to and including genus two. The double-scaling limit is analyzed and the relation to the one-cut solution of the hermitian and complex one-matrix model is discussed. (orig.)

Are the same tapes really the same? Ultrasound study of laser-cut and mechanically cut TVT-O post-operative behavior.

Science.gov (United States)

Rusavy, Zdenek; Masata, Jaromir; Svabik, Kamil; Hubka, Petr; Zvara, Karel; Martan, Alois

2017-11-25

TVT-O production has been modified to laser cutting from mechanical cutting. We compared the behavior of laser and mechanically cut tension-free vaginal tape-obturator (TVT-O) using ultrasound at various time points after surgery. This is a retrospective analysis of clinical and ultrasound data from two previously reported randomized controlled trials with TVT-O. Behavior of mechanically cut TVT-O implanted in January 2007 to November 2009 and laser-cut TVT-O implanted in May 2010 to May 2012 was assessed by ultrasound at day 1, the 2nd week, the 3rd month, and the 1st and 2nd years post-operatively. Bladder neck and tape margins positions were described by coordinates in the orthogonal system calculated from polar coordinates. Tape mobility was measured as a change in the upper and lower tape margin position from rest to maximal Valsalva. Comparison of 2-year subjective and objective surgery outcomes was also performed. In total, 68 mechanically cut and 50 laser-cut TVT-Os were implanted. Follow-up data were available from 49 and 45 women respectively. No differences in any baseline characteristics or bladder neck mobility were observed. Significantly lower tape mobility was observed on day 1 and week 2 after mechanically cut TVT-O, although subsequent mobility was comparable to laser-cut TVT-O. The subjective and objective surgery outcomes were comparable. Although without clinical significance, early postoperative behavior of the mechanically cut and laser-cut TVT-O tapes differs. The less stiff, mechanically-cut TVT-O loosens within 2 weeks of implantation, whereas the stiffer, laser-cut TVT-O keeps its tension.

SurfCut: Free-Boundary Surface Extraction

KAUST Repository

Algarni, Marei Saeed Mohammed; Sundaramoorthi, Ganesh

2016-01-01

We present SurfCut, an algorithm for extracting a smooth simple surface with unknown boundary from a noisy 3D image and a seed point. In contrast to existing approaches that extract smooth simple surfaces with boundary, our method requires less user

Effects of Cutting Edge Microgeometry on Residual Stress in Orthogonal Cutting of Inconel 718 by FEM.

Science.gov (United States)

Shen, Qi; Liu, Zhanqiang; Hua, Yang; Zhao, Jinfu; Lv, Woyun; Mohsan, Aziz Ul Hassan

2018-06-14

Service performance of components such as fatigue life are dramatically influenced by the machined surface and subsurface residual stresses. This paper aims at achieving a better understanding of the influence of cutting edge microgeometry on machined surface residual stresses during orthogonal dry cutting of Inconel 718. Numerical and experimental investigations have been conducted in this research. The cutting edge microgeometry factors of average cutting edge radius S¯, form-factor K , and chamfer were investigated. An increasing trend for the magnitudes of both tensile and compressive residual stresses was observed by using larger S¯ or introducing a chamfer on the cutting edges. The ploughing depth has been predicted based on the stagnation zone. The increase of ploughing depth means that more material was ironed on the workpiece subsurface, which resulted in an increase in the compressive residual stress. The thermal loads were leading factors that affected the surface tensile residual stress. For the unsymmetrical honed cutting edge with K = 2, the friction between tool and workpiece and tensile residual stress tended to be high, while for the unsymmetrical honed cutting edge with K = 0.5, the high ploughing depth led to a higher compressive residual stress. This paper provides guidance for regulating machine-induced residual stress by edge preparation.

The use of cutting temperature to evaluate the machinability of titanium alloys.

Science.gov (United States)

Kikuchi, Masafumi

2009-02-01

This study investigated the machinability of titanium, two commercial titanium alloys (Ti-6Al-4V and Ti-6Al-7Nb) and free-cutting brass using the cutting temperature. The cutting temperature was estimated by measuring the thermal electromotive force of the tool-workpiece thermocouple during cutting. The thermoelectric power of each metal relative to the tool had previously been determined. The metals were slotted using a milling machine and carbide square end mills under four cutting conditions. The cutting temperatures of Ti-6Al-4V and Ti-6Al-7Nb were significantly higher than that of the titanium, while that of the free-cutting brass was lower. This result coincided with the relationship of the magnitude of the cutting forces measured in a previous study. For each metal, the cutting temperature became higher when the depth of cut or the cutting speed and feed increased. The increase in the cutting speed and feed was more influential on the value than the increase in the depth of cut when two cutting conditions with the same removal rates were compared. The results demonstrated that cutting temperature measurement can be utilized to develop a new material for dental CAD/CAM applications and to optimize the cutting conditions.

Determination of cut front position in laser cutting

Science.gov (United States)

Pereira, M.; Thombansen, U.

2016-07-01

Laser cutting has a huge importance to manufacturing industry. Laser cutting machines operate with fixed technological parameters and this does not guarantee the best productivity. The adjustment of the cutting parameters during operation can improve the machine performance. Based on a coaxial measuring device it is possible to identify the cut front position during the cutting process. This paper describes the data analysis approach used to determine the cut front position for different feed rates. The cut front position was determined with good resolution, but improvements are needed to make the whole process more stable.

Implementation of Steiner point of fuzzy set.

Science.gov (United States)

Liang, Jiuzhen; Wang, Dejiang

2014-01-01

This paper deals with the implementation of Steiner point of fuzzy set. Some definitions and properties of Steiner point are investigated and extended to fuzzy set. This paper focuses on establishing efficient methods to compute Steiner point of fuzzy set. Two strategies of computing Steiner point of fuzzy set are proposed. One is called linear combination of Steiner points computed by a series of crisp α-cut sets of the fuzzy set. The other is an approximate method, which is trying to find the optimal α-cut set approaching the fuzzy set. Stability analysis of Steiner point of fuzzy set is also studied. Some experiments on image processing are given, in which the two methods are applied for implementing Steiner point of fuzzy image, and both strategies show their own advantages in computing Steiner point of fuzzy set.

Experimental testing of exchangeable cutting inserts cutting ability

OpenAIRE

Čep, Robert; Janásek, Adam; Čepová, Lenka; Petrů, Jana; Hlavatý, Ivo; Car, Zlatan; Hatala, Michal

2013-01-01

The article deals with experimental testing of the cutting ability of exchangeable cutting inserts. Eleven types of exchangeable cutting inserts from five different manufacturers were tested. The tested cutting inserts were of the same shape and were different especially in material and coating types. The main aim was both to select a suitable test for determination of the cutting ability of exchangeable cutting inserts and to design such testing procedure that could make it possible...

Machinability baja AISI 1040 pada proses bubut dengan variasi cutting speed dan feed rate

Directory of Open Access Journals (Sweden)

AAIA Sri Komaladewi

2012-11-01

Full Text Available In order to obtain desired results of machining process (turning, parameter of process and material characteristic to be machined should be well known. This is due to different machining conditions and material yield different material machinability as well. It is needed to investigate of material machinability (AISI 1040 such as force, power and shear angle under different cutting speed (80, 160 and 240 m/min and feed rate (0.1, 0.2, and 0.3 mm/rev. The results of investigation show that; at the same cutting speed the higher feed rate the higher cutting force needed; the higher cutting speed and feed rate, the higher power needed; at feed rate 0.1 mm./rev and 0.3 mm/rev, the higher cutting speed the shear angles has a trend to incline; at feed rate 0.2 mm/rev, cutting speed from 80 to 160 m/min yield increasing of shear angle, however, from 160 to 240 m/min shear angle declines.

Determination of cut front position in laser cutting

International Nuclear Information System (INIS)

Pereira, M; Thombansen, U

2016-01-01

Laser cutting has a huge importance to manufacturing industry. Laser cutting machines operate with fixed technological parameters and this does not guarantee the best productivity. The adjustment of the cutting parameters during operation can improve the machine performance. Based on a coaxial measuring device it is possible to identify the cut front position during the cutting process. This paper describes the data analysis approach used to determine the cut front position for different feed rates. The cut front position was determined with good resolution, but improvements are needed to make the whole process more stable. (paper)

Effect of cutting medium temperatures on rooting process and root primordium differentiation of hardwood cuttings of tetraploid robinia pseudoacacia cutting medium temperatures of tetraploid robinia pseudoacacia

International Nuclear Information System (INIS)

Ling, W.X.; Jine, Q.; Zhong, Z.

2014-01-01

In this study, to examine the effect of heat treatment on the rooting and root development of hardwood cuttings of the tetraploid Robinia pseudoacacia, cuttings of 1-year-old stems were taken from 3-year-old mother trees and treated with IBA solution (1000 mg/L) for 6 h, with water was as a control. Treated cuttings were rooted in heated or unheated nursery beds. Samples were collected on day ten after planting, and then for every five days. The bases of the cuttings were embedded in paraffin and sectioned before being examined under a microscope to determine whether there had been any morphological changes. We found no root primordia in the tissues of the hardwood cuttings of the tetraploid Robinia pseudoacacia before cutting. In the heated bed, adventitious roots originated from callus tissue and the junction between the pith rays and cortical parenchyma cells, and in the unheated bed, adventitious roots originated only from callus tissue. The rooting process involved callus formation, adventitious root formation and elongation; rooting occurred 5-7 days earlier in the heated cuttings than in the unheated ones, and rooting rates were significantly higher in the former 30 days and 50 days after cutting; the minimum effective accumulated temperatures for these three stages were 109.25 degree C, 211.68 degree C and 301.38 degree C, respectively. Our results revealed that heating the soil can promote adventitious root formation, speed up the rooting rate, and cut the propagation period of the tetraploid Robinia pseudoacacia. (author)

The next 16 higher spin currents and three-point functions in the large N = 4 holography

Energy Technology Data Exchange (ETDEWEB)

Ahn, Changhyun; Kim, Dong-gyu; Kim, Man Hea [Kyungpook National University, Department of Physics, Taegu (Korea, Republic of)

2017-08-15

By using the known operator product expansions (OPEs) between the lowest 16 higher spin currents of spins (1, (3)/(2), (3)/(2), (3)/(2), (3)/(2), 2,2,2,2,2,2, (5)/(2), (5)/(2), (5)/(2), (5)/(2), 3) in an extension of the large N = 4 linear superconformal algebra, one determines the OPEs between the lowest 16 higher spin currents in an extension of the large N = 4 nonlinear superconformal algebra for generic N and k. The Wolf space coset contains the group G = SU(N + 2) and the affine Kac-Moody spin 1 current has the level k. The next 16 higher spin currents of spins (2, (5)/(2), (5)/(2), (5)/(2), (5)/(2), 3,3,3,3,3,3, (7)/(2), (7)/(2), (7)/(2), (7)/(2), 4) arise in the above OPEs. The most general lowest higher spin 2 current in this multiplet can be determined in terms of affine Kac-Moody spin (1)/(2), 1 currents. By careful analysis of the zero mode (higher spin) eigenvalue equations, the three-point functions of bosonic higher spin 2, 3, 4 currents with two scalars are obtained for finite N and k. Furthermore, we also analyze the three-point functions of bosonic higher spin 2, 3, 4 currents in the extension of the large N = 4 linear superconformal algebra. It turns out that the three-point functions of higher spin 2, 3 currents in the two cases are equal to each other at finite N and k. Under the large (N, k) 't Hooft limit, the two descriptions for the three-point functions of higher spin 4 current coincide with each other. The higher spin extension of SO(4) Knizhnik Bershadsky algebra is described. (orig.)

Effect of laser incidence angle on cut quality of 4 mm thick stainless steel sheet using fiber laser

Science.gov (United States)

Mullick, Suvradip; Agrawal, Arpit Kumar; Nath, Ashish Kumar

2016-07-01

Fiber laser has potential to outperform the more traditionally used CO2 lasers in sheet metal cutting applications due to its higher efficiency, better beam quality, reliability and ease of beam delivery through optical fiber. It has been however, reported that the higher focusability and shorter wavelength are advantageous for cutting thin metal sheets up to about 2 mm only. Better focasability results in narrower kerf-width, which leads to an earlier flow separation in the flow of assist gas within the kerf, resulting in uncontrolled material removal and poor cut quality. However, the advarse effect of tight focusability can be taken care by shifting the focal point position towards the bottom surface of work-piece, which results in a wider kerf size. This results in a more stable flow within the kerf for a longer depth, which improves the cut quality. It has also been reported that fiber laser has an unfavourable angle of incidence during cutting of thick sections, resulting in poor absorption at the metal surface. Therefore, the effect of laser incidence angle, along with other process parameters, viz. cutting speed and assist gas pressure on the cut quality of 4 mm thick steel sheet has been investigated. The change in laser incidence angle has been incorporated by inclining the beam towards and away from the cut front, and the quality factors are taken as the ratio of kerf width and the striation depth. Besides the absorption of laser radiation, beam inclination is also expected to influence the gas flow characteristics inside the kerf, shear force phenomena on the molten pool, laser beam coupling and laser power distribution at the inclined cut surface. Design of experiment has been used by implementing response surface methodology (RSM) to study the parametric dependence of cut quality, as well as to find out the optimum cut quality. An improvement in quality has been observed for both the inclination due to the combined effect of multiple phenomena.

Core Cutting Test with Vertical Rock Cutting Rig (VRCR)

Science.gov (United States)

Yasar, Serdar; Osman Yilmaz, Ali

2017-12-01

Roadheaders are frequently used machines in mining and tunnelling, and performance prediction of roadheaders is important for project economics and stability. Several methods were proposed so far for this purpose and, rock cutting tests are the best choice. Rock cutting tests are generally divided into two groups which are namely, full scale rock cutting tests and small scale rock cutting tests. These two tests have some superiorities and deficiencies over themselves. However, in many cases, where rock sampling becomes problematic, small scale rock cutting test (core cutting test) is preferred for performance prediction, since small block samples and core samples can be conducted to rock cutting testing. Common problem for rock cutting tests are that they can be found in very limited research centres. In this study, a new mobile rock cutting testing equipment, vertical rock cutting rig (VRCR) was introduced. Standard testing procedure was conducted on seven rock samples which were the part of a former study on cutting rocks with another small scale rock cutting test. Results showed that core cutting test can be realized successfully with VRCR with the validation of paired samples t-test.

Magnetofluidic testing of rock cutting knives

International Nuclear Information System (INIS)

Buioca, C.D.; Iusan, Vasile; Pirlea, Remus

2002-01-01

The nondestructive testing of cutting knives consists in the determination of nonuniformity of a magnetic fluid layer applied on the horizontally placed surface of the magnetized cutting plate of the knife. A low constant magnetic field was applied perpendicular to the knife surface and a uniform magnetic fluid layer was applied. The defects as nonuniform brass layer, fissures or small cavities between the cutting plate and knife core determine the apparition of magnetic field gradients and therefore magnetic forces acting on the magnetic fluid which migrates to the zones with higher magnetic field intensity. After several minutes, a nonuniform layer of magnetic fluid was directly observed. Quantitative results, concerning the position and dimensions of the defect, were obtained by computer aided processing of the magnetic fluid layer image. Experimental data for several cutting knives are presented in the paper

Improved cutting performance in high power laser cutting

DEFF Research Database (Denmark)

Olsen, Flemming Ove

2003-01-01

Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described.......Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described....

Higher-order triangular spectral element method with optimized cubature points for seismic wavefield modeling

Science.gov (United States)

Liu, Youshan; Teng, Jiwen; Xu, Tao; Badal, José

2017-05-01

The mass-lumped method avoids the cost of inverting the mass matrix and simultaneously maintains spatial accuracy by adopting additional interior integration points, known as cubature points. To date, such points are only known analytically in tensor domains, such as quadrilateral or hexahedral elements. Thus, the diagonal-mass-matrix spectral element method (SEM) in non-tensor domains always relies on numerically computed interpolation points or quadrature points. However, only the cubature points for degrees 1 to 6 are known, which is the reason that we have developed a p-norm-based optimization algorithm to obtain higher-order cubature points. In this way, we obtain and tabulate new cubature points with all positive integration weights for degrees 7 to 9. The dispersion analysis illustrates that the dispersion relation determined from the new optimized cubature points is comparable to that of the mass and stiffness matrices obtained by exact integration. Simultaneously, the Lebesgue constant for the new optimized cubature points indicates its surprisingly good interpolation properties. As a result, such points provide both good interpolation properties and integration accuracy. The Courant-Friedrichs-Lewy (CFL) numbers are tabulated for the conventional Fekete-based triangular spectral element (TSEM), the TSEM with exact integration, and the optimized cubature-based TSEM (OTSEM). A complementary study demonstrates the spectral convergence of the OTSEM. A numerical example conducted on a half-space model demonstrates that the OTSEM improves the accuracy by approximately one order of magnitude compared to the conventional Fekete-based TSEM. In particular, the accuracy of the 7th-order OTSEM is even higher than that of the 14th-order Fekete-based TSEM. Furthermore, the OTSEM produces a result that can compete in accuracy with the quadrilateral SEM (QSEM). The high accuracy of the OTSEM is also tested with a non-flat topography model. In terms of computational

REDUCTION IN CUTS SPEED AT THE BEGINNING OF A SORTING SIDINGS, EQUIPPED WITH QUASI-CONTINUOUS SPEED CONTROL SYSTEM

Directory of Open Access Journals (Sweden)

O. A. Nazarov

2016-08-01

Full Text Available Purpose. Clear and uninterrupted operation of humps depends on the quality of technical equipment and control technology of cuts speed. Technology of interval and purposive regulation of cuts speed is used at most humps. The article discusses ways to reduce the cuts rolling speed to a safe level at the beginning of the sorting sidings equipped with quasi-continuous speed control system. Methodology. It proposed three fundamentally different ways to reduce the cuts rolling speed at the beginning of the sorting siding. The analysis of the ways to reduce cuts rolling speed to a safe level at the beginning of the sorting sidings was conducted using simulation the process of cuts rolling from humps equipped with quasi-continuous speed control. Findings. As a result of analysis, the inappropriateness of opposite elevation using on the roll-out part of the hump after the last separation switch point. Spot regulators of cars speed can be used to reduce the cuts rolling speed at the beginning of the sorting siding, but this leads to a division conditions deterioration on the last separating switch points of long cuts with the following after them short cuts. Reducing the cuts rolling speed at the beginning of the sorting siding can be carried out using the beam on a stationary wagon retarders park brake position. Control Algorithm park brake position is quite simple. All produce should be unhooked from it at a safe speed. If the accuracy of the implementation of the set speed output to unhook from the park brake position is low, it is possible to eliminate the error of point regulators cars speed. Originality. The question where to start location point of wagon retarders zone to reduce speed to cut level requires additional research. Reducing rolling cut the speed at the beginning of the sorting sidings can be carried out using the beam on a stationary wagon retarders park brake position. Practical value. Control Algorithm park brake position is quite

Shaping Cutter Original Profile for Fine-module Ratchet Teeth Cutting

Science.gov (United States)

Sharkov, O. V.; Koryagin, S. I.; Velikanov, N. L.

2018-03-01

The methods for determining geometric characteristics of a theoretical original profile of the cutter for cutting ratchet teeth with a module of 0.3–1.0 mm are considered in the article. Design models describing the shaping process of cutting edges of cutter teeth are developed. Systems of expressions for determining coordinates of the points of front and back edges of cutter teeth; the workpiece angles of rotation during the cutting process; the minimum cutter radius are received. The basic data when using the proposed technique are: radii of circumferences passing through cavities of cutter teeth and external cut teeth; the gradient angle and length of straight section of the front edge of a cut tooth; angles of rotation of the cutter and the workpiece at the moment of shaping.

Secondary emissions during fiber laser cutting of nuclear material

Energy Technology Data Exchange (ETDEWEB)

Lopez, A., E-mail: beatriz.mendes.lopez@gmail.com [IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Assunção, E. [IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); European Federation for Welding, Joining and Cutting, Porto Salvo 2740-120 (Portugal); Pires, I. [IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Quintino, L. [IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); European Federation for Welding, Joining and Cutting, Porto Salvo 2740-120 (Portugal)

2017-04-15

The laser process has been studied for dismantling work for more than 10 years, however there is almost no data available concerning secondary emissions generated during the process. These emissions are inevitable during the laser cutting process and can have detrimental effects in human health and in the equipment. In terms of safety, for nuclear decommissioning, is crucial to point out ways of controlling the emissions of the process. This paper gives indications about the parameters to be used in order to reduce these secondary emissions and about the influence of these parameters on the particles size distribution. In general, for producing minimal dross and fume emissions the beam focus should be placed on the surface of the material. The higher percentage of secondary emissions which present higher diameter, increases approximately linearly with the stand-off distance and with the use of low air pressure.

Twice cutting method reduces tibial cutting error in unicompartmental knee arthroplasty.

Science.gov (United States)

Inui, Hiroshi; Taketomi, Shuji; Yamagami, Ryota; Sanada, Takaki; Tanaka, Sakae

2016-01-01

Bone cutting error can be one of the causes of malalignment in unicompartmental knee arthroplasty (UKA). The amount of cutting error in total knee arthroplasty has been reported. However, none have investigated cutting error in UKA. The purpose of this study was to reveal the amount of cutting error in UKA when open cutting guide was used and clarify whether cutting the tibia horizontally twice using the same cutting guide reduced the cutting errors in UKA. We measured the alignment of the tibial cutting guides, the first-cut cutting surfaces and the second cut cutting surfaces using the navigation system in 50 UKAs. Cutting error was defined as the angular difference between the cutting guide and cutting surface. The mean absolute first-cut cutting error was 1.9° (1.1° varus) in the coronal plane and 1.1° (0.6° anterior slope) in the sagittal plane, whereas the mean absolute second-cut cutting error was 1.1° (0.6° varus) in the coronal plane and 1.1° (0.4° anterior slope) in the sagittal plane. Cutting the tibia horizontally twice reduced the cutting errors in the coronal plane significantly (Pcutting the tibia horizontally twice using the same cutting guide reduced cutting error in the coronal plane. Copyright © 2014 Elsevier B.V. All rights reserved.

Remotely controlled cutting techniques in the field of nuclear decommissioning. Overview of effectively applied thermal and non thermal cutting methods

International Nuclear Information System (INIS)

Bienia, H.

2008-01-01

Remote disassembly of radiologically burdened large components is among the most sophisticated and complex activities in the dismantling of nuclear installations. The required space for the technical equipment during the dismantling operations, especially for the removal of larger components is often an additional problem. Conventional cutting technologies like sawing with a disk saw or band saw require large and heavy frameworks as well as guiding systems with high rigidity. These solutions are expensive and sometimes not applicable. The essential question of all cutting and dismantling tasks is the physiological constitution of the component which will be dismantled. That means size, material and structure of the component. All these points are primarily technological questions. The last question is about the estimated costs of the used dismantling technology. Therefore following questions must be answered. How much are the investments for the cutting equipment itself and how much are the investments for the supporting equipment (e.g. necessary handling equipment)? Can I use this cutting equipment only for one special task or is it applicable for many tasks and therefore saves money because other cutting or dismantling technologies are dispensable? How long is the cutting time and what is the to control this technique required personnel? Four different cutting and dismantling technologies will be introduced and described. These four technologies differ in their principle of operation but all of them are used by cutting and dismantling tasks in nuclear power plants. (author)

Cut-Off Points for Mild, Moderate, and Severe Pain on the Numeric Rating Scale for Pain in Patients with Chronic Musculoskeletal Pain : Variability and Influence of Sex and Catastrophizing

NARCIS (Netherlands)

Boonstra, Anne M; Stewart, Roy E; Köke, Albère J A; Oosterwijk, René F A; Swaan, Jeannette L; Schreurs, Karlein M G; Schiphorst Preuper, Henrica R

2016-01-01

Objectives: The 0-10 Numeric Rating Scale (NRS) is often used in pain management. The aims of our study were to determine the cut-off points for mild, moderate, and severe pain in terms of pain-related interference with functioning in patients with chronic musculoskeletal pain, to measure the

Development of an innovative device for ultrasonic elliptical vibration cutting.

Science.gov (United States)

Zhou, Ming; Hu, Linhua

2015-07-01

An innovative ultrasonic elliptical vibration cutting (UEVC) device with 1st resonant mode of longitudinal vibration and 3rd resonant mode of bending vibration was proposed in this paper, which can deliver higher output power compared to previous UEVC devices. Using finite element method (FEM), resonance frequencies of the longitudinal and bending vibrations were tuned to be as close as possible in order to excite these two vibrations using two-phase driving voltages at a single frequency, while wave nodes of the longitudinal and bending vibrations were also adjusted to be as coincident as possible for mounting the device at a single fixed point. Based on the simulation analysis results a prototype device was fabricated, then its vibration characteristics were evaluated by an impedance analyzer and a laser displacement sensor. With two-phase sinusoidal driving voltages both of 480 V(p-p) at an ultrasonic frequency of 20.1 kHz, the developed prototype device achieved an elliptical vibration with a longitudinal amplitude of 8.9 μm and a bending amplitude of 11.3 μm. The performance of the developed UEVC device is assessed by the cutting tests of hardened steel using single crystal diamond tools. Experimental results indicate that compared to ordinary cutting process, the tool wear is reduced significantly by using the proposed device. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of cutting efficiency with different diamond burs and water flow rates in cutting lithium disilicate glass ceramic.

Science.gov (United States)

Siegel, Sharon C; Patel, Tejas

2016-10-01

This study compared different diamond burs and different water flow rates on the cutting efficiency of sectioning through lithium disilicate glass ceramic. The authors used a standardized cutting regimen with 4 brands of diamond burs to section through lithium disilicate glass ceramic blocks. Twelve diamonds of each brand cut through the blocks in randomized order. In the first part of the study, the authors recorded sectioning rates in millimeters per minute for each diamond bur as a measure of cutting efficiency. In the second part of the study, the authors compared sectioning rates using only 1 brand of diamond bur, with 3 different water flow rates. The authors averaged and compared cutting rates of each brand of diamond bur and the cutting rates for each flow rate using an analysis of variance and determined the differences with a Tukey honest significant difference test. One diamond bur cut significantly slower than the other 3, and one diamond bur cut significantly faster than 2 of the others. The diamond bur cutting efficiency through lithium disilicate glass ceramic with a 20 mL/min water flow rate was significantly higher than 15 mL/min. There are differences in cutting efficiency between diamond burs when sectioning lithium disilicate glass ceramic. Use a minimum of 20 mL/min of water coolant flow when sectioning lithium disilicate glass ceramic with dental diamond burs to maximize cutting efficiency. Recommendations for specific diamond burs with a coarse grit and water flow rate of 20 mL/min can be made when removing or adjusting restorations made from lithium disilicate glass ceramic. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

Ignition delay times of Gasoline Distillation Cuts measured with Ignition Quality Tester

KAUST Repository

Naser, Nimal

2017-04-21

Tailoring fuel properties to maximize the efficiency of internal combustion engines is a way towards achieving cleaner combustion systems. In this work, the ignition properties of various gasoline fuel distillation cuts are analyzed to better understand fuel properties of the full boiling range fuel. An advanced distillation column (ADC) provides a more realistic representation of volatility characteristics, which can be modeled using equilibrium thermodynamic methods. The temperature reported is that of the liquid, as opposed to the vapor temperature in conventional ASTM D86 distillation standard. Various FACE (fuels for advanced combustion engines) gasolines were distilled and various cuts were obtained. The separated fractions were then tested in an ignition quality tester (IQT) to see the effect of chemical composition of different fractions on their ignition delay time. Fuels with lower aromatic content showed decreasing ignition delay time with increasing boiling point (i.e., molecular weight). However, fuels with higher aromatic content showed an initial decrease in ignition delay time with increasing boiling point, followed by drastic increase in ignition delay time due to fractions containing aromatics. This study also provides an understanding on contribution of different fractions to the ignition delay time of the fuel, which provides insights into fuel stratification utilized in gasoline compression ignition (GCI) engines to tailor heat release rates.

Iowa Geologic Sampling Points

Data.gov (United States)

Iowa State University GIS Support and Research Facility — Point locations of geologic samples/files in the IGS repository. Types of samples include well cuttings, outcrop samples, cores, drillers logs, measured sections,...

The correlation function for density perturbations in an expanding universe. III The three-point and predictions of the four-point and higher order correlation functions

Science.gov (United States)

Mcclelland, J.; Silk, J.

1978-01-01

Higher-order correlation functions for the large-scale distribution of galaxies in space are investigated. It is demonstrated that the three-point correlation function observed by Peebles and Groth (1975) is not consistent with a distribution of perturbations that at present are randomly distributed in space. The two-point correlation function is shown to be independent of how the perturbations are distributed spatially, and a model of clustered perturbations is developed which incorporates a nonuniform perturbation distribution and which explains the three-point correlation function. A model with hierarchical perturbations incorporating the same nonuniform distribution is also constructed; it is found that this model also explains the three-point correlation function, but predicts different results for the four-point and higher-order correlation functions than does the model with clustered perturbations. It is suggested that the model of hierarchical perturbations might be explained by the single assumption of having density fluctuations or discrete objects all of the same mass randomly placed at some initial epoch.

Metal transfer and build-up in friction and cutting

CERN Document Server

Kuznetsov, V D

1956-01-01

Metal Transfer and Build-up in Friction and Cutting aims to systematize our knowledge of the metal build-up, to describe some of the investigations past and present carried out in SFTI (Tomsk), and to make an effort to explain a number of the phenomena in cutting, scratching, and sliding from the point of view of metal transfer theory. The book opens with a chapter on the temperature of the rubbing interface of two solids. This temperature is needed in order to elucidate the nature of the formation of a build-up in scratching, cutting, and sliding. Separate chapters follow on the seizure phen

The effect of cutting conditions on power inputs when machining

Science.gov (United States)

Petrushin, S. I.; Gruby, S. V.; Nosirsoda, Sh C.

2016-08-01

Any technological process involving modification of material properties or product form necessitates consumption of a certain power amount. When developing new technologies one should take into account the benefits of their implementation vs. arising power inputs. It is revealed that procedures of edge cutting machining are the most energy-efficient amongst the present day forming procedures such as physical and technical methods including electrochemical, electroerosion, ultrasound, and laser processing, rapid prototyping technologies etc, such as physical and technical methods including electrochemical, electroerosion, ultrasound, and laser processing, rapid prototyping technologies etc. An expanded formula for calculation of power inputs is deduced, which takes into consideration the mode of cutting together with the tip radius, the form of the replaceable multifaceted insert and its wear. Having taken as an example cutting of graphite iron by the assembled cutting tools with replaceable multifaceted inserts the authors point at better power efficiency of high feeding cutting in comparison with high-speed cutting.

Shroud cutting techniques and collection systems for secondary radioactivity release

International Nuclear Information System (INIS)

Yokoi, H.; Watanabe, A.; Uetake, N.; Shimura, T.; Omote, T.; Adachi, H.; Murakami, S.; Kobayashi, H.; Gotoh, M.

2001-01-01

Replacement of in-core shroud has been conducted as part of the preventive maintenance program in Tsuruga-1. The EDM (electric discharged machining) and plasma cutting methods were applied to in-core shroud cutting and secondary cutting in the DSP (dryer/separator pool), respectively. The cutting systems were improved in order to decrease radioactive secondary products. 1) Fundamental EDM cutting tests: fundamental EDM cutting tests were carried out in order to study secondary products. It could be presumed that volatile Co-carbonyl compound was generated by using a carbon electrode. The Ag/W electrode was effective as EDM electrode for in-core shroud cutting to prevent generation of Co-carbonyl compound and to decrease the total amount of secondary products. 2) In-core shroud cutting in RPV (reactor pressure vessel): EDM cutting system with the Ag/W electrode and collection system could keep a good environment during in-core shroud cutting in Tsuruga-1. Activity concentration was lower value than limitation of mask charge level, 4E-6 Bq/cm 3 , even near the water surface. 3) Secondary plasma cutting in DSP: the secondary cutting work was successful in the point of reduction of working period and radiation exposure. The amount of radiation exposure was reduced to 60% of the planned value, because of adequate decontamination of the working environment and reduction of number of torch maintenance tasks by improvements of the underwater cutting device

Cut-Off Points for Mild, Moderate, and Severe Pain on the Numeric Rating Scale for Pain in Patients with Chronic Musculoskeletal Pain: Variability and Influence of Sex and Catastrophizing

NARCIS (Netherlands)

Boonstra, A.M.; Stewart, R.; Koke, A.J.A.; Oosterwijk, R.F.A.; Swaan, J.L.; Schreurs, Karlein Maria Gertrudis; Schiphorst Preuper, H.R.

2016-01-01

Objectives: The 0–10 Numeric Rating Scale (NRS) is often used in pain management. The aims of our study were to determine the cut-off points for mild, moderate, and severe pain in terms of pain-related interference with functioning in patients with chronic musculoskeletal pain, to measure the

Investigating the CO 2 laser cutting parameters of MDF wood composite material

Science.gov (United States)

Eltawahni, H. A.; Olabi, A. G.; Benyounis, K. Y.

2011-04-01

Laser cutting of medium density fibreboard (MDF) is a complicated process and the selection of the process parameters combinations is essential to get the highest quality cut section. This paper presents a means for selecting the process parameters for laser cutting of MDF based on the design of experiments (DOE) approach. A CO 2 laser was used to cut three thicknesses, 4, 6 and 9 mm, of MDF panels. The process factors investigated are: laser power, cutting speed, air pressure and focal point position. In this work, cutting quality was evaluated by measuring the upper kerf width, the lower kerf width, the ratio between the upper kerf width to the lower kerf width, the cut section roughness and the operating cost. The effect of each factor on the quality measures was determined. The optimal cutting combinations were presented in favours of high quality process output and in favours of low cutting cost.

Investigation of tool engagement and cutting performance in machining a pocket

Science.gov (United States)

Adesta, E. Y. T.; Hamidon, R.; Riza, M.; Alrashidi, R. F. F. A.; Alazemi, A. F. F. S.

2018-01-01

This study investigates the variation of tool engagement for different profile of cutting. In addition, behavior of cutting force and cutting temperature for different tool engagements for machining a pocket also been explored. Initially, simple tool engagement models were developed for peripheral and slot cutting for different types of corner. Based on these models, the tool engagements for contour and zig zag tool path strategies for a rectangular shape pocket with dimension 80 mm x 60 mm were analyzed. Experiments were conducted to investigate the effect of tool engagements on cutting force and cutting temperature for the machining of a pocket of AISI H13 material. The cutting parameters used were 150m/min cutting speed, 0.05mm/tooth feed, and 0.1mm depth of cut. Based on the results obtained, the changes of cutting force and cutting temperature performance there exist a relationship between cutting force, cutting temperature and tool engagement. A higher cutting force and cutting temperature is obtained when the cutting tool goes through up milling and when the cutting tool makes a full engagement with the workpiece.

Study of AFM-based nanometric cutting process using molecular dynamics

International Nuclear Information System (INIS)

Zhu Pengzhe; Hu Yuanzhong; Ma Tianbao; Wang Hui

2010-01-01

Three-dimensional molecular dynamics (MD) simulations are conducted to investigate the atomic force microscope (AFM)-based nanometric cutting process of copper using diamond tool. The effects of tool geometry, cutting depth, cutting velocity and bulk temperature are studied. It is found that the tool geometry has a significant effect on the cutting resistance. The friction coefficient (cutting resistance) on the nanoscale decreases with the increase of tool angle as predicted by the macroscale theory. However, the friction coefficients on the nanoscale are bigger than those on the macroscale. The simulation results show that a bigger cutting depth results in more material deformation and larger chip volume, thus leading to bigger cutting force and bigger normal force. It is also observed that a higher cutting velocity results in a larger chip volume in front of the tool and bigger cutting force and normal force. The chip volume in front of the tool increases while the cutting force and normal force decrease with the increase of bulk temperature.

Effects of plant growth promoting rhizobacteria (PGPR on rooting and root growth of kiwifruit (Actinidia deliciosa stem cuttings

Directory of Open Access Journals (Sweden)

YASAR ERTURK

2010-01-01

Full Text Available The effects of plant growth promoting rhizobacteria (PGPR on the rooting and root growth of semi-hardwood and hardwood kiwifruit stem cuttings were investigated. The PGPR used were Bacillus RC23, Paenibacillus polymyxa RC05, Bacillus subtilis OSU142, Bacillus RC03, Comamonas acidovorans RC41, Bacillus megaterium RC01 and Bacillus simplex RC19. All the bacteria showed indole-3-acetic acid (IAA producing capacity. Among the PGPR used, the highest rooting ratios were obtained at 47.50% for semi-hardwood stem cuttings from Bacillus RC03 and Bacillus simplex RC19 treatments and 42.50% for hardwood stem cuttings from Bacillus RC03. As well, Comamonas acidovorans RC41 inoculations indicated higher value than control treatments. The results suggest that these PGPR can be used in organic nursery material production and point to the feasibility of synthetic auxin (IBA replacement by organic management based on PGPR.

Cutting thin glass by femtosecond laser ablation

Science.gov (United States)

Shin, Hyesung; Kim, Dongsik

2018-06-01

The femtosecond laser ablation process for cutting thin aluminoborosilicate glass sheets of thickness 100 μm was investigated with emphasis on effective cutting speed (Veff) and mechanical strength of diced samples. The process parameters including the laser fluence (F), overlap ratio (r) of the laser beam and polarization direction were varied at a fixed pulse repetition rate f = 1 kHz to find the optimal process condition that maximizes Veff and edge strength. A three-point bending test was performed to evaluate the front-side and back-side bending (edge) strength of the laser-cut samples. Veff was proportional to F unless r exceeded a critical value, at which excessive energy began to be delivered at the same spot. The front-side edge strength was bigger than the back-side strength because of the back-side damages such as chipping. Good edge strength, as high as ∼280 MPa (front-side) and ∼230 MPa (back-side), was obtained at F = 19 J/m2, r = 0.99, with laser polarization vertical to the cutting path.

A cutting-edge solution for 1µm laser metal processing

Science.gov (United States)

Baumbach, N.; Kühl, P.; Karam, J.; Jonkers, J.; Villarreal-Saucedo, F.; Reyes, M.

2017-02-01

The recent 1μm-laser cutting market is dominated by fiber and disk lasers due to their excellent beam quality of below 4mm*mrad. Teradiode's 4kW direct diode laser source achieves similar beam quality while having a different beam shape and shorter wavelengths which are known for higher absorption rates at the inclined front of the cutting keyhole. Research projects, such as the HALO Project, have additionally shown that polarized radiation and beams with shapes different from the typical LG00 lead to improved cut quality for ferrous and non-ferrous metals. [1] Diode laser have the inherent property of not being sensitive to back reflection which brings advantages in cutting high-reflective materials. The II-VI HIGHYAG laser cutting head BIMO-FSC offers the unique feature of machine controlled and continuous adjustment of both the focus diameter and the focus position. This feature is proven to be beneficial for cutting and piercing with high speed and small hole diameters. In addition, the optics are designed for lowest focus shift. As a leading laser processing head manufacturer, II-VI HIGHYAG qualified its BIMO-FSC MZ (M=magnification, Z=focus position) cutting head for Teradiode's 4kW direct diode laser source to offer a cutting-edge solution for highpower laser cutting. Combining the magnification ability of the cutting head with this laser source, customers experience strong advantages in cutting metals in broad thickness ranges. Thicknesses up to 25mm mild steel can easily be cut with excellent edge quality. Furthermore, a new optical setup equivalent to an axicon with a variable axicon angle is demonstrated which generates variable sized ring spots. The setup provides new degrees of freedom to tailor the energy distribution for even higher productivity and quality.

Characterisation of debris from laser and mechanical cutting of bone.

Science.gov (United States)

Rachmanis, Nikolaos; McGuinness, Garrett B; McGeough, Joseph A

2014-07-01

Laser cutting of bones has been proposed as a technology in orthopaedic surgery. In this short study, the laser-bone interaction was examined using a pulsed erbium-doped yttrium aluminium garnet laser and compared to a conventional cutting technique. Microscopic analysis revealed the nature of waste debris and showed higher proportions of finer particles for conventional sagittal sawing compared to laser cutting. © IMechE 2014.

Fibre laser cutting stainless steel: Fluid dynamics and cut front morphology

Science.gov (United States)

Pocorni, Jetro; Powell, John; Deichsel, Eckard; Frostevarg, Jan; Kaplan, Alexander F. H.

2017-01-01

In this paper the morphology of the laser cut front generated by fibre lasers was investigated by observation of the 'frozen' cut front, additionally high speed imaging (HSI) was employed to study the fluid dynamics on the cut front while cutting. During laser cutting the morphology and flow properties of the melt film on the cut front affect cut quality parameters such as cut edge roughness and dross (residual melt attached to the bottom of the cut edge). HSI observation of melt flow down a laser cutting front using standard cutting parameters is experimentally problematic because the cut front is narrow and surrounded by the kerf walls. To compensate for this, artificial parameters are usually chosen to obtain wide cut fronts which are unrepresentative of the actual industrial process. This paper presents a new experimental cutting geometry which permits HSI of the laser cut front using standard, commercial parameters. These results suggest that the cut front produced when cutting medium section (10 mm thick) stainless steel with a fibre laser and a nitrogen assist gas is covered in humps which themselves are covered by a thin layer of liquid. HSI observation and theoretical analysis reveal that under these conditions the humps move down the cut front at an average speed of approximately 0.4 m/s while the covering liquid flows at an average speed of approximately 1.1 m/s, with an average melt depth at the bottom of the cut zone of approximately 0.17 mm.

Factors influencing laser cutting of wood

Science.gov (United States)

V.G. Barnekov; C.W. McMillin; H.A. Huber

1986-01-01

Factors influencing the ability of lasers to cut wood may be generally classified into these three areas: 1) characteristics of the laser beam; 2) equipment and processing variables; and 3) properties of the workpiece. Effects of beam power, mode, polarization, and stability are discussed as are aspects of optics, location of focal point, feed speed, gas-jet assist...

Plasma arc and thermal lance techniques for cutting concrete and steel

International Nuclear Information System (INIS)

Bargagliotti, A.; Caprile, L.; Piana, F.; Tolle, E.

1986-01-01

The plasma arc technique is used today in industrial practice for any metal, but mainly for cutting stainless steel, carbon steel and aluminium. In air the maximum thickness that was cut in the performed tests was 150 mm, both with ferritic and austenitic steel. Underwater the maximum thickness cut was 103 mm. The two types of torch used in the tests are those used today: the plasma-shaped electrode torch (WIPC) and the pointed electrode torch (DMC-GRUEN). Two different types of gas were compared: an argon-nitrogen mixture and an argon-hydrogen mixture. The second mixture adopted results in less dust emission. The production of dust and aerosols also depends on the cutting speed, on the kind of steel, but mainly on the environmental conditions; it is reduced up to 500 times under water. Dust and aerosols can, jeopardize the efficiency of the system; moreover, the ambient air can have high-level radiation fields. Indirect and direct protections are needed (shields, remote control, robots, etc.). Tentative procedures for dismantling two types of BWR reactor are examined. Two series of tests demonstrated the feasibility of cutting the most geometrically difficult parts of the reactor internals. The thermal lance technique is used in industrial practice mainly for dismantling large reinforced concrete structures. This technique can be applied to dismantle nuclear facilities, even though it can cause some problems due to the gases, fumes and lapilli produced. In addition, the cost of this technique seems to be generally higher than the cost of other techniques. From the analyses done, the conclusion seems that both the above techniques are feasible for dismantling a nuclear power plant (NPP). The best solution is probably to analyse the different dismantling possibilities and problems and problems of each case

Effect of Cut Quality on Hybrid Laser Arc Welding of Thick Section Steels

Science.gov (United States)

Farrokhi, F.; Nielsen, S. E.; Schmidt, R. H.; Pedersen, S. S.; Kristiansen, M.

From an industrial point of view, in a laser cutting-welding production chain, it is of great importance to know the influence of the attainable laser cut quality on the subsequent hybrid laser arc welding process. Many studies have been carried out in the literature to obtain lower surface roughness values on the laser cut edge. However, in practice, the cost and reliability of the cutting process is crucial and it does not always comply with obtaining the highest surface quality. In this study, a number of experiments on 25 mm steel plates were carried out to evaluate the influence of cut surface quality on the final quality of the subsequent hybrid laser welded joints. The different cut surfaces were obtained by different industrial cutting methods including laser cutting, abrasive water cutting, plasma cutting, and milling. It was found that the mentioned cutting methods could be used as preparation processes for the subsequent hybrid laser arc welding. However, cut quality could determine the choice of process parameters of the following hybrid laser arc welding.

Measurement of batter movements in brown coal open cuts - results of a research project

Energy Technology Data Exchange (ETDEWEB)

Nehring, H

1984-05-01

In the course of a research project sponsored by the State of North Rhine-Westphalia the mine surveying methods used when measuring deformation on open cut batters were further developed, by taking into account the special conditions prevailing in open cuts, to such an extent that the essential monitoring of soil movements can be carried out reliably and promptly. As an integral part of an optimised, accurate geodetic measurement of points, the direct measurement of longitude across the open cut was introduced as a rapid measuring method. The aerophotogrammetric measurement of points is practically as accurate as terrestrial surveying. The author describes the prototype of an automatically operated instrument system for the monitoring of points. In conclusion he also stresses that the first promising advance has already been made as regards the sufficiently accurate monitoring of rock movements in boreholes.

Higher point spin field correlators in D=4 superstring theory

International Nuclear Information System (INIS)

Haertl, D.; Schlotterer, O.; Stieberger, S.

2010-01-01

Calculational tools are provided allowing to determine general tree-level scattering amplitudes for processes involving bosons and fermions in heterotic and superstring theories in four space-time dimensions. We compute higher-point superstring correlators involving massless four-dimensional fermionic and spin fields. In D=4 these correlators boil down to a product of two pure spin field correlators of left- and right-handed spin fields. This observation greatly simplifies the computation of such correlators. The latter are basic ingredients to compute multi-fermion superstring amplitudes in D=4. Their underlying fermionic structure and the fermionic couplings in the effective action are determined by these correlators.

A Surgery Issue: Cutting through the Architectural Fabric

Directory of Open Access Journals (Sweden)

Athina Angelopoulou

2017-12-01

Full Text Available This essay examines the material ontologies of surgical trans-modifications. Focusing on incisions and subsequent scars, the essay argues for the queering of architecture and design as an act of cutting through structures and processes. I start by rereading a topological body plan, used by surgeons as a guide for performing incisions. I suggest that this plan constitutes a variation within topological representations. It is thus reconceptualised as an internally contradictory representation, calling for dis/continuous cutting acts upon the represented body; that is an amphi-topological representation. The notion of the cut is further approached from the point of view of queer theory and ‘agential realism’. This perspective offers affirmative ways of discussing about acts of cutting. When performed into self-organizing fabrics, cuts appear to act as ‘agents of dis/continuity’. Then, the discussion passes through the genealogy of the architectural section and the building cuts of Gordon Matta Clark, so as to show that the production of buildings by ‘cutting through them to come to matter’ is deep-rooted in the architectural discipline. Next, the philosophical origins of the idea of cutting through the material fabric of the world are sought. It is argued that the latter, beginning as a gnosiological tool, was transformed into a fabricating tool and then into a tool of smoothing the striated. The essay concludes with the presentation of SCARchiCAD; a computational design tool which takes the skin’s wound healing process as a model, offering an interpretation of what the ‘cutting through a virtual form’ could suggest for the design of architectural bodies and the queering of architecture.

On Computations of Duct Acoustics with Near Cut-Off Frequency

Science.gov (United States)

Dong, Thomas Z.; Povinelli, Louis A.

1997-01-01

The cut-off is a unique feature associated with duct acoustics due to the presence of duct walls. A study of this cut-off effect on the computations of duct acoustics is performed in the present work. The results show that the computation of duct acoustic modes near cut-off requires higher numerical resolutions than others to avoid being numerically cut off. Duct acoustic problems in Category 2 are solved by the DRP finite difference scheme with the selective artificial damping method and results are presented and compared to reference solutions.

Cutting state identification

International Nuclear Information System (INIS)

Berger, B.S.; Minis, I.; Rokni, M.

1997-01-01

Cutting states associated with the orthogonal cutting of stiff cylinders are identified through an analysis of the singular values of a Toeplitz matrix of third order cumulants of acceleration measurements. The ratio of the two pairs of largest singular values is shown to differentiate between light cutting, medium cutting, pre-chatter and chatter states. Sequences of cutting experiments were performed in which either depth of cut or turning frequency was varied. Two sequences of experiments with variable turning frequency and five with variable depth of cut, 42 cutting experiments in all, provided a database for the calculation of third order cumulants. Ratios of singular values of cumulant matrices find application in the analysis of control of orthogonal cutting

Experimental Research Using of MQL in Metal Cutting

Directory of Open Access Journals (Sweden)

G. Globočki Lakić

2013-12-01

Full Text Available In this paper an effect of using of minimal quantity lubrication (MQL technique in turning operations is presented. Experimental research was performed on carbon steel C45E. Technological parameters: depth of cut, feed rate and cutting speed were adjusted to semi-machining and roughing. Higher values ​​of feed and cutting speed were used, than recommended from literature and different types of cooling and lubrication in turning conditions were applied. As a conventional procedure and technology, lubrication with flooding was applied. As special lubrication the MQL technique was used. During research, monitoring of the cutting force, chip shape, tool wear and surface roughness was performed. Relations between parameters, material machinability and economy of process were analyzed.

Cut-off parameters in the one-dimensional two-fermion model

International Nuclear Information System (INIS)

Apostol, M.

1982-07-01

It is shown that the usual cut-off procedure (α cut-off parameter) employed in the boson representation of the fermion field opepators of the one-djmensional two-fermion model (TFM) is an incorrect one as the computator of the hermitean-conjugate field operators at the same space-point fails to fulfil a certain relationship which was pointed out long ago by Jordan. The complete form of the boson representation (including the zero-mode) of a single fermion field and the correct values of the cut-off parameter α is reviewed following Jordan and generalized to the TFM. The cut-off parameter α corresponds to a bandwidth cut-off and Jordan's boson representation is exact only in the limit α → 0. The additional zero-mode terms make the exact solution of the backscattering and umklapp scattering problem to be valid only if a supplementary condition is imposed on the coupling constants. Using the present bosonization technique all the inconsistencies of the TFM are removed. The one-particle Green's function and response functions of the Tomonaga-Luttinger model (TLM) are calculated and found to be identical with those obtained by direct diagram summation. The energy gap appearing in the spectrum of the TFM with backscattering and umklapp scattering for certain values of the coupling constants is shown to be proportional to the momentum transfer cut-off γ -1 which has to be kept finite while α goes to zero. Under such conditions the anticommunication relations and Jordan's commutator are invariant under the canonical transformation on the boson operators that diagonalizes the Hamiltonian of the TLM. The charge-density response function of the TFM with backscattering is perturbationally calculated up to the first order. The cut-off α -1 applies in the same way to terms which differ only by their spin indices in the expression of this response function. The charge-density response function is also evaluated at low frequencies for the exactly soluble TFM with

Cutting the Cord

Science.gov (United States)

2004-01-01

This animation shows the view from the front hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting off the front lander petal. Before this crucial turn could take place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

Strategic partnerships, alliances used to find ways to cut costs

International Nuclear Information System (INIS)

Bruce, G.; Shermer, R.

1993-01-01

In a commoditized industry like oil and gas, building a sustainable source of competitive advantage is difficult at best. By and large, oil and gas companies are packed in a footrace to cut costs, increase efficiency, and gain market share. It is such a tight race that virtually every contender has reorganized, right-sized, and rationalized to the point that their cost-cutting programs have themselves become a commodity. Facing this problem, many firms are turning to strategic partnership and alliances to find new, more-permanent ways to cut costs. Partnerships and alliances offer many new avenues for cutting costs and significant advantages over more traditional approaches. Those firms that take advantage of these opportunities by bundling operations in new ways to create new organizations will be the industry leaders in years to come

Shaping of Rack Cutter Original Profile for Fine-module Ratchet Teeth Cutting

Science.gov (United States)

Sharkov, O. V.; Koryagin, S. I.; Velikanov, N. L.

2018-05-01

The design models and the process of shaping the cutting edges of the rack cutter for cutting fine-module ratchet teeth are considered in the article. The use of fine-module ratchet teeth can reduce the noise and impact loads during operation of the freewheel mechanisms. Mathematical dependencies for calculating the coordinates determining the geometric position of the points of the front and back edges of the cutting profile of the rack cutter, the workpiece angle of rotation during cutting the ratchet teeth were obtained. When applying the developed method, the initial data are: the radii of the workpiece circumferences passing through the dedendum of the external and internal cut teeth; gradient angles of the front and back edges of the rail.

Plasma cutting or laser cutting. Plasma setsudan ka laser setsudan ka

Energy Technology Data Exchange (ETDEWEB)

Nakamura, A. (Tanaka Engineering Works Ltd., Saitama (Japan))

1991-05-01

Comparisons and discussions were made on the plasma cutting and laser cutting in sheet steel cutting, referring partly to gas cutting. Historically, the cutting has been developed from gas, plasma, and laser in that order, and currently these three methods are used mixedly. Generally, the plasma cutting is superior in cutting speed, but inferior in cut face quality, and it requires measures of dust collection. Due to high accuracy and quality in cut face, the laser cutting has been practically used for quite some time in the thin sheet industry, but medium to thick sheet cutting had a problem of unavailability of high output laser suitable for these ranges. However, the recent technologies have overcome the problem as a result of development at the authors {prime} company of a 2 kW class laser cutter capable of cutting 19 mm thick sheet. The cutter has been proven being particularly excellent in controllability. Choice of whether plasma or laser would depend upon which priority is to be taken, cost or accuracy. 15 figs., 3 tabs.

Effect of Moisture Content of Paper Material on Laser Cutting

Science.gov (United States)

Stepanov, Alexander; Saukkonen, Esa; Piili, Heidi; Salminen, Antti

Laser technology has been used in industrial processes for several decades. The most advanced development and implementation took place in laser welding and cutting of metals in automotive and ship building industries. However, there is high potential to apply laser processing to other materials in various industrial fields. One of these potential fields could be paper industry to fulfill the demand for high quality, fast and reliable cutting technology. Difficulties in industrial application of laser cutting for paper industry are associated to lack of basic information, awareness of technology and its application possibilities. Nowadays possibilities of using laser cutting for paper materials are widened and high automation level of equipment has made this technology more interesting for manufacturing processes. Promising area of laser cutting application at paper making machines is longitudinal cutting of paper web (edge trimming). There are few locations at a paper making machine where edge trimming is usually done: wet press section, calender or rewinder. Paper web is characterized with different moisture content at different points of the paper making machine. The objective of this study was to investigate the effect of moisture content of paper material on laser cutting parameters. Effect of moisture content on cellulose fibers, laser absorption and energy needed for cutting is described as well. Laser cutting tests were carried out using CO2 laser.

Generation Mechanism of Work Hardened Surface Layer in Metal Cutting

Science.gov (United States)

Hikiji, Rikio; Kondo, Eiji; Kawagoishi, Norio; Arai, Minoru

Finish machining used to be carried out in grinding, but it is being replaced by cutting with very small undeformed chip thickness. In ultra precision process, the effects of the cutting conditions and the complicated factors on the machined surface integrity are the serious problems. In this research, work hardened surface layer was dealt with as an evaluation of the machined surface integrity and the effect of the mechanical factors on work hardening was investigated experimentally in orthogonal cutting. As a result, it was found that work hardened surface layer was affected not only by the shear angle varied under the cutting conditions and the thrust force of cutting resistance, but also by the thrust force acting point, the coefficient of the thrust force and the compressive stress equivalent to the bulk hardness. Furthermore, these mechanical factors acting on the depth of the work hardened surface layer were investigated with the calculation model.

Geometry, penetration force, and cutting profile of different 23-gauge trocars systems for pars plana vitrectomy.

Science.gov (United States)

Meyer, Carsten H; Kaymak, Hakan; Liu, Zengping; Saxena, Sandeep; Rodrigues, Eduardo B

2014-11-01

To investigate the geometry, penetration force, and cutting profile of 23-gauge trocar systems for pars plana vitrectomy based on their grinding methods in a standardized laboratory setting. In this experimental study, Eleven different commercially available 23-gauge sclerotomy trocar systems were divided into 4 groups according to their needle grinding and deburring: "back" bevel, "spear" bevel, "lancet" bevel, and "spatula" bevel. The normative geometrical data of the trocar systems were systematically analyzed according to nomenclature ISO 7864 and ISO 9626. Force to penetrate a 0.4-mm thick polyurethane foil was measured by a Penetrometer, when the trocar needle was piercing, cutting, and sliding through the foil at different defined loading phases and plotted as a load-displacement diagram. Magnified images of the consecutive cut were taken under a microscope after the entire penetration through the foil. Three physicians used all trocar systems in a masked fashion on human sclera to evaluate the manual penetration force in 30° and 90°. The mean outer diameter of the trocar systems was 0.630 ± 0.009 mm, and the mean outer diameter of the trocars was 0.750 ± 0.013 mm. The mean point length was 3.11 ± 0.49 mm, and the mean length of the bevel was 1.46 ± 0.23 mm. The primary bevel angle was 10.75 ± 0.41°, and the secondary bevel angle was 65.9 ± 42.56°. The piercing forces of the back bevel and spear-pointed trocars/needles were at the same level (0.087 ± 0.028 N). The lancet-pointed needle had remarkable low piercing and cutting forces with 0.41 N (range, 0.35-0.47 N). The spatula bevel tip showed the highest penetration piercing force with 1.6 N (range, 1.59-1.73 N). The back bevel systems induced frequently triangular-shaped incisions, with two nearly rectangular cuts of short length. The spear bevels produced a regular characteristic linear cut. Especially, the lancet blade created straight cut with a linear wound apposition. Spatula trocar systems

Wedge cutting of mild steel by CO 2 laser and cut-quality assessment in relation to normal cutting

Science.gov (United States)

Yilbas, B. S.; Karatas, C.; Uslan, I.; Keles, O.; Usta, Y.; Yilbas, Z.; Ahsan, M.

2008-10-01

In some applications, laser cutting of wedge surfaces cannot be avoided in sheet metal processing and the quality of the end product defines the applicability of the laser-cutting process in such situations. In the present study, CO 2 laser cutting of the wedge surfaces as well as normal surfaces (normal to laser beam axis) is considered and the end product quality is assessed using the international standards for thermal cutting. The cut surfaces are examined by the optical microscopy and geometric features of the cut edges such as out of flatness and dross height are measured from the micrographs. A neural network is introduced to classify the striation patterns of the cut surfaces. It is found that the dross height and out of flatness are influenced significantly by the laser output power, particularly for wedge-cutting situation. Moreover, the cut quality improves at certain value of the laser power intensity.

Equivalence of two Fixed-Point Semantics for Definitional Higher-Order Logic Programs

Directory of Open Access Journals (Sweden)

Angelos Charalambidis

2015-09-01

Full Text Available Two distinct research approaches have been proposed for assigning a purely extensional semantics to higher-order logic programming. The former approach uses classical domain theoretic tools while the latter builds on a fixed-point construction defined on a syntactic instantiation of the source program. The relationships between these two approaches had not been investigated until now. In this paper we demonstrate that for a very broad class of programs, namely the class of definitional programs introduced by W. W. Wadge, the two approaches coincide (with respect to ground atoms that involve symbols of the program. On the other hand, we argue that if existential higher-order variables are allowed to appear in the bodies of program rules, the two approaches are in general different. The results of the paper contribute to a better understanding of the semantics of higher-order logic programming.

A Novel Haptic Interactive Approach to Simulation of Surgery Cutting Based on Mesh and Meshless Models

Science.gov (United States)

Liu, Peter X.; Lai, Pinhua; Xu, Shaoping; Zou, Yanni

2018-01-01

In the present work, the majority of implemented virtual surgery simulation systems have been based on either a mesh or meshless strategy with regard to soft tissue modelling. To take full advantage of the mesh and meshless models, a novel coupled soft tissue cutting model is proposed. Specifically, the reconstructed virtual soft tissue consists of two essential components. One is associated with surface mesh that is convenient for surface rendering and the other with internal meshless point elements that is used to calculate the force feedback during cutting. To combine two components in a seamless way, virtual points are introduced. During the simulation of cutting, the Bezier curve is used to characterize smooth and vivid incision on the surface mesh. At the same time, the deformation of internal soft tissue caused by cutting operation can be treated as displacements of the internal point elements. Furthermore, we discussed and proved the stability and convergence of the proposed approach theoretically. The real biomechanical tests verified the validity of the introduced model. And the simulation experiments show that the proposed approach offers high computational efficiency and good visual effect, enabling cutting of soft tissue with high stability. PMID:29850006

Submerged cutting of steel by abrasive water jets

International Nuclear Information System (INIS)

Haferkamp, H.; Louis, H.; Meier, G.

1990-01-01

A special cutting head for underwater use was designed and built. Tests were carried out to find out useful parameters for submerged cutting. With regard to the production of secondary waste the abrasive flow rate had to be minimized. This was achieved by using a small water jet nozzle (up to 0.4 mm diameter) and a high pressure (up to 4000 bar) with an optimal abrasive flow rate of about 5 g/s. In the case of a higher ambient pressure a decrease of the cutting performance was measured. But this decrease is not important regarding decommissioning because the ambient pressure is less than 2 bar. An air mantle nozzle was adapted to the cutting head to improve the working distance under water. The air mantle surrounding the abrasive jet lowers the friction between jet and surrounding water and increases the cutting efficiency in the case of greater working distances. (author)

Cutting force model for high speed machining process

International Nuclear Information System (INIS)

Haber, R. E.; Jimenez, J. E.; Jimenez, A.; Lopez-Coronado, J.

2004-01-01

This paper presents cutting force-based models able to describe a high speed machining process. The model considers the cutting force as output variable, essential for the physical processes that are taking place in high speed machining. Moreover, this paper shows the mathematical development to derive the integral-differential equations, and the algorithms implemented in MATLAB to predict the cutting force in real time MATLAB is a software tool for doing numerical computations with matrices and vectors. It can also display information graphically and includes many toolboxes for several research and applications areas. Two end mill shapes are considered (i. e. cylindrical and ball end mill) for real-time implementation of the developed algorithms. the developed models are validated in slot milling operations. The results corroborate the importance of the cutting force variable for predicting tool wear in high speed machining operations. The developed models are the starting point for future work related with vibration analysis, process stability and dimensional surface finish in high speed machining processes. (Author) 19 refs

Exotic quantum holonomy and higher-order exceptional points in quantum kicked tops

OpenAIRE

Tanaka, Atushi; Kim, Sang Wook; Cheon, Taksu

2014-01-01

The correspondence between exotic quantum holonomy that occurs in families of Hermitian cycles, and exceptional points (EPs) for non-Hermitian quantum theory is examined in quantum kicked tops. Under a suitable condition, an explicit expressions of the adiabatic parameter dependencies of quasienergies and stationary states, which exhibit anholonomies, are obtained. It is also shown that the quantum kicked tops with the complexified adiabatic parameter have a higher order EP, which is broken i...

Detection of cut-off point for rapid automized naming test in good readers and dyslexics

Directory of Open Access Journals (Sweden)

Zahra Soleymani

2014-01-01

Full Text Available Background and Aim: Rapid automized naming test is an appropriate tool to diagnose learning disability even before teaching reading. This study aimed to detect the cut-off point of this test for good readers and dyslexics.Methods: The test has 4 parts including: objects, colors, numbers and letters. 5 items are repeated on cards randomly for 10 times. Children were asked to name items rapidly. We studied 18 dyslexic students and 18 age-matched good readers between 7 and 8 years of age at second and third grades of elementary school; they were recruited by non-randomize sampling into 2 groups: children with developmental dyslexia from learning disabilities centers with mean age of 100 months, and normal children with mean age of 107 months from general schools in Tehran. Good readers selected from the same class of dyslexics.Results: The area under the receiver operating characteristic curve was 0.849 for letter naming, 0.892 for color naming, 0.971 for number naming, 0.887 for picture naming, and 0.965 totally. The overall sensitivity and specificity was 1 and was 0.79, respectively. The highest sensitivity and specificity were related to number naming (1 and 0.90, respectively.Conclusion: Findings showed that the rapid automized naming test could diagnose good readers from dyslexics appropriately.

Influence of non-edible vegetable based oil as cutting fluid on chip, surface roughness and cutting force during drilling operation of Mild Steel

Science.gov (United States)

Susmitha, M.; Sharan, P.; Jyothi, P. N.

2016-09-01

Friction between work piece-cutting tool-chip generates heat in the machining zone. The heat generated reduces the tool life, increases surface roughness and decreases the dimensional sensitiveness of work material. This can be overcome by using cutting fluids during machining. They are used to provide lubrication and cooling effects between cutting tool and work piece and cutting tool and chip during machining operation. As a result, important benefits would be achieved such longer tool life, easy chip flow and higher machining quality in the machining processes. Non-edible vegetable oils have received considerable research attention in the last decades owing to their remarkable improved tribological characteristics and due to increasing attention to environmental issues, have driven the lubricant industry toward eco friendly products from renewable sources. In the present work, different non-edible vegetable oils are used as cutting fluid during drilling of Mild steel work piece. Non-edible vegetable oils, used are Karanja oil (Honge), Neem oil and blend of these two oils. The effect of these cutting fluids on chip formation, surface roughness and cutting force are investigated and the results obtained are compared with results obtained with petroleum based cutting fluids and dry conditions.

The prevalence rate of internet addiction among Japanese college students: two cross-sectional studies and reconsideration of cut-off points of Young's internet addiction test in Japan.

Science.gov (United States)

Tateno, Masaru; Teo, Alan R; Shiraishi, Masaki; Tayama, Masaya; Kawanishi, Chiaki; Kato, Takahiro A

2018-05-30

Due to variation in estimates of the prevalence of internet addiction (IA) in prior research, we conducted two cross-sectional studies over two years and investigated the prevalence rate of IA in college students in Japan, and reconsidered appropriate cut-off points of self-rating scale to screen possible IA. This study is composed of two parts: survey I in 2014 and survey II in 2016, which were conducted in the same schools with an interval of two years. The study questionnaire included questions about demographics and internet use, and the Young's Internet Addiction Test (IAT). Additionally, the subjects in survey II were asked about self-reported IA. There were 1,005 respondents in total with a mean age of 18.9±1.3. The mean IAT scores remained stable between 2014 and 2016: 45.2±12.6 in survey I and 45.5±13.1 in survey II (overall mean IAT score of 45.4±13.0). With respect to self-reported IA in survey II, a total of 21.6% agreed (score of 5 or 6 on a 6-point Likert scale). We categorized these subjects as IA, and the remainder as non-IA. The mean IAT score showed significant difference between these two groups (57.8±14.3 vs 42.1±10.7, p<0.001). The severity of symptoms of IA among Japanese college students appears stable in recent years, with a mean IAT scores of over 40. Our results suggest that a screening score cut-off of 40 on the IAT could be reconsidered and that of 50 might be proposed for the cut-off. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

TransCut: interactive rendering of translucent cutouts.

Science.gov (United States)

Li, Dongping; Sun, Xin; Ren, Zhong; Lin, Stephen; Tong, Yiying; Guo, Baining; Zhou, Kun

2013-03-01

We present TransCut, a technique for interactive rendering of translucent objects undergoing fracturing and cutting operations. As the object is fractured or cut open, the user can directly examine and intuitively understand the complex translucent interior, as well as edit material properties through painting on cross sections and recombining the broken pieces—all with immediate and realistic visual feedback. This new mode of interaction with translucent volumes is made possible with two technical contributions. The first is a novel solver for the diffusion equation (DE) over a tetrahedral mesh that produces high-quality results comparable to the state-of-art finite element method (FEM) of Arbree et al. but at substantially higher speeds. This accuracy and efficiency is obtained by computing the discrete divergences of the diffusion equation and constructing the DE matrix using analytic formulas derived for linear finite elements. The second contribution is a multiresolution algorithm to significantly accelerate our DE solver while adapting to the frequent changes in topological structure of dynamic objects. The entire multiresolution DE solver is highly parallel and easily implemented on the GPU. We believe TransCut provides a novel visual effect for heterogeneous translucent objects undergoing fracturing and cutting operations.

Performance of diamond and point attack coal cutter picks

Energy Technology Data Exchange (ETDEWEB)

Liu, Y. [CSIRO, Brisbane, Qld. (Australia). Division of Exploration and Mining

1996-12-31

This paper presents results of laboratory experiments and field trials of PDC (Polycrystalline Diamond Compact) and PA (Point Attack) coal cutter picks. Laboratory cutting tests included linear rock and coal cutting and turning rock cutting. The following parameters were measured to assess performance of PDC and PA cutter picks: cutting force, normal force, specific energy consumption, yield, dust generation and ignitional characteristics (temperature rise). Field trials were conducted on a longwall shearer. Performance of both types of pick interims of pick life and dust generation were assessed. 3 refs., 18 figs., 3 tabs.

Leptogenesis: The other cuts

International Nuclear Information System (INIS)

Garbrecht, Bjoern

2011-01-01

For standard leptogenesis from the decay of singlet right-handed neutrinos, we derive source terms for the lepton asymmetry that are present in a finite density background but absent in the vacuum. These arise from cuts through the vertex correction to the decay asymmetry, where in the loop either the Higgs boson and the right-handed neutrino or the left-handed lepton and the right-handed neutrino are simultaneously on-shell. We evaluate the source terms numerically and use them to calculate the lepton asymmetry for illustrative points in parameter space, where we consider only two right-handed neutrinos for simplicity. Compared to calculations where only the standard cut through the propagators of left-handed lepton and Higgs boson is included, sizable corrections arise when the masses of the right-handed neutrinos are of the same order, but the new sources are found to be most relevant when the decaying right-handed neutrino is heavier than the one in the loop. In that situation, they can yield the dominant contribution to the lepton asymmetry.

Systematic Study of the Content of Phytochemicals in Fresh and Fresh-Cut Vegetables

Directory of Open Access Journals (Sweden)

María Isabel Alarcón-Flores

2015-05-01

Full Text Available Vegetables and fruits have beneficial properties for human health, because of the presence of phytochemicals, but their concentration can fluctuate throughout the year. A systematic study of the phytochemical content in tomato, eggplant, carrot, broccoli and grape (fresh and fresh-cut has been performed at different seasons, using liquid chromatography coupled to triple quadrupole mass spectrometry. It was observed that phenolic acids (the predominant group in carrot, eggplant and tomato were found at higher concentrations in fresh carrot than in fresh-cut carrot. However, in the case of eggplant, they were detected at a higher content in fresh-cut than in fresh samples. Regarding tomato, the differences in the content of phenolic acids between fresh and fresh-cut were lower than in other matrices, except in winter sampling, where this family was detected at the highest concentration in fresh tomato. In grape, the flavonols content (predominant group was higher in fresh grape than in fresh-cut during all samplings. The content of glucosinolates was lower in fresh-cut broccoli than in fresh samples in winter and spring sampling, although this trend changes in summer and autumn. In summary, phytochemical concentration did show significant differences during one-year monitoring, and the families of phytochemicals presented different behaviors depending on the matrix studied.

Effect sizes and cut-off points: a meta-analytical review of burnout in latin American countries.

Science.gov (United States)

García-Arroyo, Jose; Osca Segovia, Amparo

2018-05-02

Burnout is a highly prevalent globalized health issue that causes significant physical and psychological health problems. In Latin America research on this topic has increased in recent years, however there are no studies comparing results across countries, nor normative reference cut-offs. The present meta-analysis examines the intensity of burnout (emotional exhaustion, cynicism and personal accomplishment) in 58 adult nonclinical samples from 8 countries (Argentina, Brazil, Chile, Colombia, Ecuador, Mexico, Peru and Venezuela). We found low intensity of burnout but there are significant differences between countries in emotional exhaustion explained by occupation and language. Social and human service professionals (police officers, social workers, public administration staff) are more exhausted than health professionals (physicians, nurses) or teachers. The samples with Portuguese language score higher in emotional exhaustion than Spanish, supporting the theory of cultural relativism. Demographics (sex, age) and study variables (sample size, instrument), were not found significant to predict burnout. The effect size and confidence intervals found are proposed as a useful baseline for research and medical diagnosis of burnout in Latin American countries.

Cutting forces during turning with variable depth of cut

Directory of Open Access Journals (Sweden)

M. Sadílek

2016-03-01

The proposed research for the paper is an experimental work – measuring cutting forces and monitoring of the tool wear on the cutting edge. It compares the turning where standard roughing cycle is used and the turning where the proposed roughing cycle with variable depth of cut is applied.

Endophytic fungi reduce leaf-cutting ant damage to seedlings

Science.gov (United States)

Bittleston, L. S.; Brockmann, F.; Wcislo, W.; Van Bael, S. A.

2011-01-01

Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (Ehigh) or low (Elow) densities of endophytes. The Ehigh seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the Elow treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from Elow relative to Ehigh seedlings and had a tendency to recruit more ants to Elow plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420

The cutting of metals via plastic buckling

Science.gov (United States)

Udupa, Anirudh; Viswanathan, Koushik; Ho, Yeung; Chandrasekar, Srinivasan

2017-06-01

The cutting of metals has long been described as occurring by laminar plastic flow. Here we show that for metals with large strain-hardening capacity, laminar flow mode is unstable and cutting instead occurs by plastic buckling of a thin surface layer. High speed in situ imaging confirms that the buckling results in a small bump on the surface which then evolves into a fold of large amplitude by rotation and stretching. The repeated occurrence of buckling and folding manifests itself at the mesoscopic scale as a new flow mode with significant vortex-like components-sinuous flow. The buckling model is validated by phenomenological observations of flow at the continuum level and microstructural characteristics of grain deformation and measurements of the folding. In addition to predicting the conditions for surface buckling, the model suggests various geometric flow control strategies that can be effectively implemented to promote laminar flow, and suppress sinuous flow in cutting, with implications for industrial manufacturing processes. The observations impinge on the foundations of metal cutting by pointing to the key role of stability of laminar flow in determining the mechanism of material removal, and the need to re-examine long-held notions of large strain deformation at surfaces.

Optimization of Cutting Parameters of the Haynes 718 Nickel Alloy With Gas CO2 Laser

Directory of Open Access Journals (Sweden)

Jana PETRŮ

2011-06-01

Full Text Available This article deals with the application of laser technology and the optimization of parameters in the area of nickel alloy laser cutting intended for application in the aircraft industry. The main goal is to outline possibilities of use of the laser technology, primarily its application in the area of 3D material cutting. This experiment is focused on the optimization of cutting parameters of the Haynes 718 alloy with a gas CO2 laser. Originating cuts are evaluated primarily from the point of view of cut quality and accompanying undesirable phenomena occurring in the process of cutting. In conclusion the results achieved in the metallographic laboratory are described and analyzed.

Sinuous Flow in Cutting of Metals

Science.gov (United States)

Yeung, Ho; Viswanathan, Koushik; Udupa, Anirudh; Mahato, Anirban; Chandrasekar, Srinivasan

2017-11-01

Using in situ high-speed imaging, we unveil details of a highly unsteady plastic flow mode in the cutting of annealed and highly strain-hardening metals. This mesoscopic flow mode, termed sinuous flow, is characterized by repeated material folding, large rotation, and energy dissipation. Sinuous flow effects a very large shape transformation, with local strains of ten or more, and results in a characteristic mushroomlike surface morphology that is quite distinct from the well-known morphologies of metal-cutting chips. Importantly, the attributes of this unsteady flow are also fundamentally different from other well-established unsteady plastic flows in large-strain deformation, like adiabatic shear bands. The nucleation and development of sinuous flow, its dependence on material properties, and its manifestation across material systems are demonstrated. Plastic buckling and grain-scale heterogeneity are found to play key roles in triggering this flow at surfaces. Implications for modeling and understanding flow stability in large-strain plastic deformation, surface quality, and preparation of near-strain-free surfaces by cutting are discussed. The results point to the inadequacy of the widely used shear-zone models, even for ductile metals.

Leaf processing behaviour in Atta leafcutter ants: 90% of leaf cutting takes place inside the nest, and ants select pieces that require less cutting.

Science.gov (United States)

Garrett, Ryan W; Carlson, Katherine A; Goggans, Matthew Scott; Nesson, Michael H; Shepard, Christopher A; Schofield, Robert M S

2016-01-01

Leafcutter ants cut trimmings from plants, carry them to their underground nests and cut them into smaller pieces before inoculating them with a fungus that serves as a primary food source for the colony. Cutting is energetically costly, so the amount of cutting is important in understanding foraging energetics. Estimates of the cutting density, metres of cutting per square metre of leaf, were made from samples of transported leaf cuttings and of fungal substrate from field colonies of Atta cephalotes and Atta colombica. To investigate cutting inside the nest, we made leaf-processing observations of our laboratory colony, A. cephalotes. We did not observe the commonly reported reduction of the leaf fragments into a pulp, which would greatly increase the energy cost of processing. Video clips of processing behaviours, including behaviours that have not previously been described, are linked. An estimated 2.9 (±0.3) km of cutting with mandibles was required to reduce a square metre of leaf to fungal substrate. Only about 12% (±1%) of this cutting took place outside of the nest. The cutting density and energy cost is lower for leaf material with higher ratios of perimeter to area, so we tested for, and found that the laboratory ants had a preference for leaves that were pre-cut into smaller pieces. Estimates suggest that the energy required to transport and cut up the leaf material is comparable to the metabolic energy available from the fungus grown on the leaves, and so conservation of energy is likely to be a particularly strong selective pressure for leafcutter ants.

Factors influencing laser cutting of wood

Energy Technology Data Exchange (ETDEWEB)

Barnekov, V. G.; McMillin, C. W.; Huber, H. A.

1986-07-01

Factors influencing the ability of lasers to cut wood may be generally classified into these three areas: 1) characteristics of the laser beam; 2) equipment and processing variables; and 3) properties of the work piece. Effects of beam power, mode, polarization, and stability are discussed as are aspects of optics, location of focal point, feed speed, gas-jet assist system and work piece thickness, density, and moisture content. (author)

Urine lipoarabinomannan point-of-care testing in patients affected by pulmonary nontuberculous mycobacteria - experiences from the Danish Cystic Fibrosis cohort study

DEFF Research Database (Denmark)

Qvist, Tavs; Johansen, Isik S.; Pressler, Tania

2014-01-01

had active TB. The TB-LAM test had an overall positive rate of 2.5% applying a grade 2 cut-point as positivity threshold, increasing to 10.6% (21/198) if a grade 1 cut-point was applied. Among patients with NTM infection 2/23 (8.7%) had a positive LAM test result at the grade 2 cut-point and 9/23 (39.......1%) at the grade 1 cut -point. Test specificity for NTM diagnosis was 98.3% and 93.1 for grade 2 and 1 cut-point respectively. Conclusions: This is the first study to assess urine LAM detection in patients with confirmed NTM infection. The study demonstrated low cross-reactivity due to NTM infection when using...... the recommended grade 2 cut-point as positivity threshold. This is reassuring in regards to interpretation of the LAM test for TB diagnosis in a TB prevalent setting. The test was not found suitable for NTM detection among patients with CF....

Collaborating to Cut Costs in Higher Education

Science.gov (United States)

Hassett, Tracy

2017-01-01

Tuition prices at colleges and universities are high. It is also true that salaries and benefits are the single biggest chunk of every higher education institution's (HEI) budget. And one of the largest and most difficult costs to contain is group employee health insurance. The situation is particularly difficult for smaller New England HEIs…

Cutting method and cutting device for spent fuel rod of nuclear reactor

International Nuclear Information System (INIS)

Komatsu, Masahiko; Ose, Toshihiko.

1996-01-01

A control rod transferred under water in a vertically suspended state is postured horizontally at such a water depth that radiations can be shielded, and then it is cut to a dropping speed limiting portion and a cross-like main body. The separated cross-like main body portion is further cut in the longitudinal direction and separated into a pair of cut pieces each having an L-shaped cross section. A disk like metal saw is used as a cutting tool. Alternatively, a plasma jet cutter or a melting-type water jet cutter is used as a cutting tool. Then, since the spent control rod to be cut is postured horizontally under water, the water depth for the cutting position can be reduced. As a result, the cutting state using the cutting tool can be observed by naked eyes from the position above the water surface thereby enabling to perform the cutting operation reliably. (N.H.)

Rooting Platanus (Platanus acerifolia (Aiton Willd. cuttings in Marechal Cândido Rondon - PR, Brazil: Influence of lesions at cutting bases and depth of planting

Directory of Open Access Journals (Sweden)

Danimar Dalla Rosa

2018-01-01

Full Text Available Platanus, an arboreal and deciduous plant, is widely adapted and can be used for several purposes. Despite producing viable seeds, production of platanus seedlings usually occurs through vegetative propagation; cuttings are the best and most efficient source for obtaining seedlings. Although cuttings offer a practical and easy method to obtain seedlings in different vegetable species, they are influenced by several factors, both external and internal. The present study aimed to analyze the behavior of plantain cuttings planted in sand subjected to damage or no damage at the cuttings base, and planted at depths of 20 and 40 cm. Experiment was carried out at the experimental station of horticulture and protected cultivation of UNIOESTE-Brazil, in a randomized 2×2 factorial design, which comprises both, planted at 20 cm and 40 cm depths, with 5 replicates and 5 cuttings per replicate. After 170 days of incubation, injured and non- injured cuttings, were evaluated for rooting percentage and cuttings sprouted, length of roots and medium length of stems, stem diameter, number of leaves per stem, and dry mass of roots and shoots. No significant differences were observed in cutting injury. All variables analyzed presented higher values when cuttings were planted at 20 cm depth. Results indicate that planting of platanus cuttings at 20 cm depth leads to better rooting rates and vegetative development.

Cut-off Grade Optimization for Maximizing the Output Rate

Directory of Open Access Journals (Sweden)

A. Khodayari

2012-12-01

Full Text Available In the open-pit mining, one of the first decisions that must be made in production planning stage, after completing the design of final pit limits, is determining of the processing plant cut-off grade. Since this grade has an essential effect on operations, choosing the optimum cut-off grade is of considerable importance. Different goals may be used for determining optimum cut-off grade. One of these goals may be maximizing the output rate (amount of product per year, which is very important, especially from marketing and market share points of view. Objective of this research is determining the optimum cut-off grade of processing plant in order to maximize output rate. For performing this optimization, an Operations Research (OR model has been developed. The object function of this model is output rate that must be maximized. This model has two operational constraints namely mining and processing restrictions. For solving the model a heuristic method has been developed. Results of research show that the optimum cut-off grade for satisfying pre-stated goal is the balancing grade of mining and processing operations, and maximum production rate is a function of the maximum capacity of processing plant and average grade of ore that according to the above optimum cut-off grade must be sent to the plant.

A review of cutting mechanics and modeling techniques for biological materials.

Science.gov (United States)

Takabi, Behrouz; Tai, Bruce L

2017-07-01

This paper presents a comprehensive survey on the modeling of tissue cutting, including both soft tissue and bone cutting processes. In order to achieve higher accuracy in tissue cutting, as a critical process in surgical operations, the meticulous modeling of such processes is important in particular for surgical tool development and analysis. This review paper is focused on the mechanical concepts and modeling techniques utilized to simulate tissue cutting such as cutting forces and chip morphology. These models are presented in two major categories, namely soft tissue cutting and bone cutting. Fracture toughness is commonly used to describe tissue cutting while Johnson-Cook material model is often adopted for bone cutting in conjunction with finite element analysis (FEA). In each section, the most recent mathematical and computational models are summarized. The differences and similarities among these models, challenges, novel techniques, and recommendations for future work are discussed along with each section. This review is aimed to provide a broad and in-depth vision of the methods suitable for tissue and bone cutting simulations. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Cutting the Cord-2

Science.gov (United States)

2004-01-01

This animation shows the view from the rear hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting from the front lander petal. Before this crucial turn took place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

Multiobjective Optimization of Turning Cutting Parameters for J-Steel Material

Directory of Open Access Journals (Sweden)

Adel T. Abbas

2016-01-01

Full Text Available This paper presents a multiobjective optimization study of cutting parameters in turning operation for a heat-treated alloy steel material (J-Steel with Vickers hardness in the range of HV 365–395 using uncoated, unlubricated Tungsten-Carbide tools. The primary aim is to identify proper settings of the cutting parameters (cutting speed, feed rate, and depth of cut that lead to reasonable compromises between good surface quality and high material removal rate. Thorough exploration of the range of cutting parameters was conducted via a five-level full-factorial experimental matrix of samples and the Pareto trade-off frontier is identified. The trade-off among the objectives was observed to have a “knee” shape, in which certain settings for the cutting parameters can achieve both good surface quality and high material removal rate within certain limits. However, improving one of the objectives beyond these limits can only happen at the expense of a large compromise in the other objective. An alternative approach for identifying the trade-off frontier was also tested via multiobjective implementation of the Efficient Global Optimization (m-EGO algorithm. The m-EGO algorithm was successful in identifying two points within the good range of the trade-off frontier with 36% fewer experimental samples.

Some possibilities for determining cutting data when using laser cutting:

OpenAIRE

Radovanović, Miroslav

2006-01-01

The technological problems faced in the field of the application of laser-cutting machines lie in insufficient knowledge of the laser technique and the absence of both sufficiently reliable practical data and knowledge about the parameters affecting the work process itself. A significant parameter that is necessary to determine and to enter in an NC-program is the cutting speed. Various authors analyze the laser-cutting process and give mathematical models where laser cutting is modeled by us...

Laser Cutting of Thick Diamond Films Using Low-Power Laser

Energy Technology Data Exchange (ETDEWEB)

Park, Y.J.; Baik, Y.J. [Korea Institute of Science and Technology, Seoul (Korea)

2000-02-01

Laser cutting of thick diamond films is studied rising a low-power(10 W) copper vapor laser. Due to the existence of the saturation depth in laser cutting, thick diamond films are not easily cut by low-power lasers. In this study, we have adopted a low thermal- conductivity underlayer of alumina and a heating stage (up to 500 deg. C in air) to prevent the laser energy from consuming-out and, in turn, enhance the cutting efficiency. Aspect ratio increases twice from 3.5 to 7 when the alumina underlayer used. Adopting a heating stage also increases aspect ratio and more than 10 is obtained at higher temperatures than 400 deg. C. These results show that thick diamond films can be cut, with low-power lasers, simply by modifying the thermal property of underlayer. (author). 13 refs., 5 figs.

Assessing normative cut points through differential item functioning analysis: an example from the adaptation of the Middlesex Elderly Assessment of Mental State (MEAMS) for use as a cognitive screening test in Turkey.

Science.gov (United States)

Tennant, Alan; Küçükdeveci, Ayse A; Kutlay, Sehim; Elhan, Atilla H

2006-03-23

The Middlesex Elderly Assessment of Mental State (MEAMS) was developed as a screening test to detect cognitive impairment in the elderly. It includes 12 subtests, each having a 'pass score'. A series of tasks were undertaken to adapt the measure for use in the adult population in Turkey and to determine the validity of existing cut points for passing subtests, given the wide range of educational level in the Turkish population. This study focuses on identifying and validating the scoring system of the MEAMS for Turkish adult population. After the translation procedure, 350 normal subjects and 158 acquired brain injury patients were assessed by the Turkish version of MEAMS. Initially, appropriate pass scores for the normal population were determined through ANOVA post-hoc tests according to age, gender and education. Rasch analysis was then used to test the internal construct validity of the scale and the validity of the cut points for pass scores on the pooled data by using Differential Item Functioning (DIF) analysis within the framework of the Rasch model. Data with the initially modified pass scores were analyzed. DIF was found for certain subtests by age and education, but not for gender. Following this, pass scores were further adjusted and data re-fitted to the model. All subtests were found to fit the Rasch model (mean item fit 0.184, SD 0.319; person fit -0.224, SD 0.557) and DIF was then found to be absent. Thus the final pass scores for all subtests were determined. The MEAMS offers a valid assessment of cognitive state for the adult Turkish population, and the revised cut points accommodate for age and education. Further studies are required to ascertain the validity in different diagnostic groups.

Assessing normative cut points through differential item functioning analysis: An example from the adaptation of the Middlesex Elderly Assessment of Mental State (MEAMS for use as a cognitive screening test in Turkey

Directory of Open Access Journals (Sweden)

Kutlay Sehim

2006-03-01

Full Text Available Abstract Background The Middlesex Elderly Assessment of Mental State (MEAMS was developed as a screening test to detect cognitive impairment in the elderly. It includes 12 subtests, each having a 'pass score'. A series of tasks were undertaken to adapt the measure for use in the adult population in Turkey and to determine the validity of existing cut points for passing subtests, given the wide range of educational level in the Turkish population. This study focuses on identifying and validating the scoring system of the MEAMS for Turkish adult population. Methods After the translation procedure, 350 normal subjects and 158 acquired brain injury patients were assessed by the Turkish version of MEAMS. Initially, appropriate pass scores for the normal population were determined through ANOVA post-hoc tests according to age, gender and education. Rasch analysis was then used to test the internal construct validity of the scale and the validity of the cut points for pass scores on the pooled data by using Differential Item Functioning (DIF analysis within the framework of the Rasch model. Results Data with the initially modified pass scores were analyzed. DIF was found for certain subtests by age and education, but not for gender. Following this, pass scores were further adjusted and data re-fitted to the model. All subtests were found to fit the Rasch model (mean item fit 0.184, SD 0.319; person fit -0.224, SD 0.557 and DIF was then found to be absent. Thus the final pass scores for all subtests were determined. Conclusion The MEAMS offers a valid assessment of cognitive state for the adult Turkish population, and the revised cut points accommodate for age and education. Further studies are required to ascertain the validity in different diagnostic groups.

Remote Laser Cutting of CFRP: Improvements in the Cut Surface

Science.gov (United States)

Stock, Johannes; Zaeh, Michael F.; Conrad, Markus

In the automotive industry carbon fibre reinforced plastics (CFRP) are considered as a future key material to reduce the weight of the vehicle. Therefore, capable production techniques are required to process this material in mass industry. E.g., state of the art methods for cutting are limited by the high tool wear or the feasible feed rate. Laser cutting processes are still under investigation. This paper presents detailed new studies on remote laser cutting of CFRP focusing on the influence of the material properties and the quality of the cut surface. By adding light absorbing soot particles to the resin of the matrix, the cutting process is improved and fewer defects emerge.

Multibeam Fibre Laser Cutting

DEFF Research Database (Denmark)

Olsen, Flemming Ove

The appearance of the high power high brilliance fibre laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO2-laser. However, quality problems in fibre......-laser cutting have until now limited its application in metal cutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with high brightness short wavelength lasers will be presented. In the approach, multi beam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from 2 single mode fibre lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W of single...

Multibeam fiber laser cutting

DEFF Research Database (Denmark)

Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

2009-01-01

The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber......-laser cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

Regeneration of Mature Norway Spruce Stands: Early Effects of Selective Cutting and Clear Cutting on Seepage Water Quality and Soil Fertility

Directory of Open Access Journals (Sweden)

Wendelin Weis

2001-01-01

Full Text Available The cutting of trees influences element turnover in the forest ecosystem. The reduction of plant uptake, as well as an increased mineralization and nitrification due to higher soil temperature and soil moisture, can lead to considerable losses of nutrients from the main rooting zone. This may result in a reduced soil fertility and a decrease in drinking water quality due to high nitrate concentrations in the seepage water. In Bavaria (Germany selective cutting is preferred to clear cutting when initiating the regeneration of Norway spruce stands with European beech. This paper summarizes the early effects of both forest management practices on soil fertility and seepage water quality for three different sites. Shown are the concentrations of nitrogen and base cations in the seepage water as well as the water and ion fluxes during the first year after tree cut. Nutrient inputs decreased on thinned plots and even more at clear-cuts. Nitrate concentrations in the seepage water are hardly affected by moderate thinning; however, on clear-cuts, the nitrate concentration increases significantly, and base cations are lost from the upper mineral soil. This effect is less obvious at sites where a dense ground vegetation, which is able to take up excess nitrogen, exists.

Cutting cleaner

International Nuclear Information System (INIS)

Elsen, R.P.H. van; Smits, M.

1991-01-01

This paper presents the results of a long term field test of the Cutting Cleaner, which is used for the treatment of wet oil contaminated cuttings (WOCC) produced when drilling with Oil Based Mud (OBM). It was concluded that it is possible to reduce the oil content of cuttings to an average of 1 - 2%. The recovered base oil can be reused to make new oil based mud

Exotic quantum holonomy and higher-order exceptional points in quantum kicked tops.

Science.gov (United States)

Tanaka, Atushi; Kim, Sang Wook; Cheon, Taksu

2014-04-01

The correspondence between exotic quantum holonomy, which occurs in families of Hermitian cycles, and exceptional points (EPs) for non-Hermitian quantum theory is examined in quantum kicked tops. Under a suitable condition, an explicit expression of the adiabatic parameter dependencies of quasienergies and stationary states, which exhibit anholonomies, is obtained. It is also shown that the quantum kicked tops with the complexified adiabatic parameter have a higher-order EP, which is broken into lower-order EPs with the application of small perturbations. The stability of exotic holonomy against such bifurcation is demonstrated.

Investigation of active vibration drilling using acoustic emission and cutting size analysis

Directory of Open Access Journals (Sweden)

Yingjian Xiao

2018-04-01

Full Text Available This paper describes an investigation of active bit vibration on the penetration mechanisms and bit-rock interaction for drilling with a diamond impregnated coring bit. A series of drill-off tests (DOTs were conducted where the drilling rate-of-penetration (ROP was measured at a series of step-wise increasing static bit thrusts or weight-on-bits (WOBs. Two active DOTs were conducted by applying 60 Hz axial vibration at the bit-rock interface using an electromagnetic vibrating table mounted underneath the drilling samples, and a passive DOT was conducted where the bit was allowed to vibrate naturally with lower amplitude due to the compliance of the drilling sample mountings. During drilling, an acoustic emission (AE system was used to record the AE signals generated by the diamond cutter penetration and the cuttings were collected for grain size analysis. The instrumented drilling system recorded the dynamic motions of the bit-rock interface using a laser displacement sensor, a load cell, and an LVDT (linear variable differential transformer recorded the dynamic WOB and the ROP, respectively. Calibration with the drilling system showed that rotary speed was approximately the same at any given WOB, facilitating comparison of the results at the same WOB. Analysis of the experimental results shows that the ROP of the bit at any given WOB increased with higher amplitude of axial bit-rock vibration, and the drill cuttings increased in size with a higher ROP. Spectral analysis of the AEs indicated that the higher ROP and larger cutting size were correlated with a higher AE energy and a lower AE frequency. This indicated that larger fractures were being created to generate larger cutting size. Overall, these results indicate that a greater magnitude of axial bit-rock vibration produces larger fractures and generates larger cuttings which, at the same rotary speed, results in a higher ROP. Keywords: Active bit vibration, Diamond coring drilling, Drill

Hairy Slices: Evaluating the Perceptual Effectiveness of Cutting Plane Glyphs for 3D Vector Fields.

Science.gov (United States)

Stevens, Andrew H; Butkiewicz, Thomas; Ware, Colin

2017-01-01

Three-dimensional vector fields are common datasets throughout the sciences. Visualizing these fields is inherently difficult due to issues such as visual clutter and self-occlusion. Cutting planes are often used to overcome these issues by presenting more manageable slices of data. The existing literature provides many techniques for visualizing the flow through these cutting planes; however, there is a lack of empirical studies focused on the underlying perceptual cues that make popular techniques successful. This paper presents a quantitative human factors study that evaluates static monoscopic depth and orientation cues in the context of cutting plane glyph designs for exploring and analyzing 3D flow fields. The goal of the study was to ascertain the relative effectiveness of various techniques for portraying the direction of flow through a cutting plane at a given point, and to identify the visual cues and combinations of cues involved, and how they contribute to accurate performance. It was found that increasing the dimensionality of line-based glyphs into tubular structures enhances their ability to convey orientation through shading, and that increasing their diameter intensifies this effect. These tube-based glyphs were also less sensitive to visual clutter issues at higher densities. Adding shadows to lines was also found to increase perception of flow direction. Implications of the experimental results are discussed and extrapolated into a number of guidelines for designing more perceptually effective glyphs for 3D vector field visualizations.

Prevalensi Sarkopenia pada Lansia di Komunitas (Community Dwelling berdasarkan Dua Nilai Cut-off Parameter Diagnosis

Directory of Open Access Journals (Sweden)

Vitriana

2016-09-01

Full Text Available Sarcopenia, aging muscle mass loss, and function syndromes can lead to decreased quality of life and increased elderly mortality. The availability of various screening methods and operational definitions in different studies has produced different findings of sarcopenia prevalence. The purpose of this study was to discover the prevalence of sarcopenia in Indonesian community-dwelling elderly based on muscle mass measured by bioimpedance analysis, handgrip strength using hand dynamometer, and physical performance based on six minutes walking test with two different cut-off point parameters of sarcopenia, i.e. the cut-off point recommended by Asian Working Group for Sarcopenia (AWGS and the cut-off point based on the reference used in Taiwan elderly population reference due to the lack of references for Indonesian elderly population. A cross-sectional study was conducted to 229 participants (71 men and 158 women from the community-dwelling elderly population between August and December 2014 in Bandung and Jatinangor. The results of the study showed that the sarcopenia prevalence in this study based on AWGS was 9.1% (7.4% in men and 1.7% in women while the prevalence based on the Taiwan reference revealed a prevalence of 40.6% (20.1% in men and 20.5% in women. This highly different prevalences shows the importance of defining a specific cut-off point for elderly population in community-dwelling Indonesia to get a more accurate sarcopenia prevalence.

Science Funding cuts threaten scientific research

CERN Multimedia

2008-01-01

Page 1 of 3 Researchers are in uproar after a recently established quango unveiled a series of cuts and abandoned some projects altogether because of an estimated 80m funding shortfall. Martin Rees, the Astronomer Royal, argues that Britain will pay a far higher price if it scraps vital projects now

Laser cutting or water-jet cutting. Laser setsudan ka water-jet setsudan ka

Energy Technology Data Exchange (ETDEWEB)

Yamada, T. (Shibuya Kogyo Co. Ltd., Ishikawa (Japan))

1991-05-01

The recent spread of carbon oxide laser cutter is so startlingly fast, but at the same time, water jet cutting using ultra high pressure water stream is drawing attention as it has identical characteristics, and opens the way to cutting materials that have been hitherto difficult to cut. The authors, who are fabricators of cutters of both types, gave the comparisons and explanations on several examples referring to materials that can be cut, cutting accuracy, speed, shape and thermal effects to cut face, and running cost in detail. However, simple comparison is difficult. For instance, cutting 6 mm thick SUS sheet costs a running cost of 65 yen per meter in laser cutting, and 535 yen per meter in water jet cutting, but this situation is often reversed when other material or sheet thickness is selected. The actual situation in the sheet metal processing industry at the present time is that it uses by far more laser processing machines, and uses water jet cutters to supplement for cutting materials more difficult to cut. 10 figs., 3 tabs.

Measuring the State-of-the-Art in Laser Cut Quality

OpenAIRE

Pocorni, Jetro; Powell, John; Ilar, Torbjörn; Schwarz, A.; Kaplan, Alexander

2013-01-01

This paper discusses the strategy appropriate to investigating the state of the art of laser cutting from an industrial point of view. The importance of creating the samples in a high quality industrial environment is emphasised and preliminary results are presented.

Effect of Irradiation on the Hygienic, Chemical and Sensory Quality of Minimally Processed Fresh-Cut Carrot

International Nuclear Information System (INIS)

Mansour, F.A.; Hammad, A.A.; SwaiIam, H.M.; Abu EI-Nour, S.A.; Serag, M.S.

2008-01-01

The Average total bacteria count (TAPC) in the collected 15 samples of fresh-cut carrot ranged from 1.4 x 10 4 to 2.4x10 6 cfu/ g; lactic acid bacteria (LAB) between 5.0xl0 2 and 2.4xl0 5 cfu/ g; total mould and yeast (TM and Y) ranged from 2 cfu/ g indicating high level of microbial load and most of these samples were unacceptable from the view point of microbial load. All examined fresh-cut carrot samples had coliforms at value ranged from 43 to 1100 MPN/g and contained Escherichia coli in the range of 9 to 460 MPN/ g indicating that most of these samples were unsatisfactory due to the presence of E. coli at level higher than 100 MPN/ g. Enterococcus faecalis count was below the detectable level (100 cfu/ g). Staphylococcus aureus was detected in the majority (80 %) of the tested fresh-cut carrot samples, and were present at 1.0x10 2 to 2.3x10 3 cfu/g. Aeromonas hydrophila was detected in only 5 (33.3) samples with average counts 1.0x10 2 to 4.5xl0 2 cfu/g. The presence of E. coli, Staph. aureus and A. hydrophila in some samples of fresh-cut carrots is to be viewed as a health hazard. On the other hand, no Listeria monocytogenes or Salmonella spp. was detected in any of the fifteen fresh-cut carrot samples. Irradiation dose of 2 kGy extended the refrigeration shelf life of fresh-cut carrots to almost 12 days. The shelf-life for unirradiated samples was about 6 days. Irradiation dose of 4 kGy was identified to be the optimum irradiation dose for irradiating fresh-cut carrots. This irradiation dose greatly reduced the T APC (by 99.95 %) and decreased LAB and TM and Y to below the detectable level (<10 cfu/ g). Fresh-cut carrot samples receiving 4 kGy irradiation doses were free from studied indicator microorganisms and from pathogens via

Technology development for cutting a reactor pressure vessel using a mechanical cutting technique

International Nuclear Information System (INIS)

Watanabe, Masaaki; Miyasaka, Yasuhiko; Miyao, Hidehiko; Ooki, Arahiko; Ninomiya, Toshiaki; Koiwai, Masami

2001-01-01

On decommissioning of nuclear facilities, the thermal cutting technique such as an oxygen-acetylene gas cutting and a plasma arc cutting are generally used for cutting massive and thick steel structures in consideration with cutting speed and control performance. These techniques generate dust, smoke, aerosol and a large quantity of secondary waste. Mechanical cutting technique has an advantage of small amount of secondary waste, and the metal chips from the kerf recovered easily compared with these thermal cutting technique. The remote mechanical cutting system for highly activated RPV has been developed with the manner which achieves the safety and cost effectiveness. The development has been performed on consignment to RANDEC from the Science and Technology Agency of Japan. (author)

Automatic MPST-cut for segmentation of carpal bones from MR volumes.

Science.gov (United States)

Gemme, Laura; Nardotto, Sonia; Dellepiane, Silvana G

2017-08-01

In the context of rheumatic diseases, several studies suggest that Magnetic Resonance Imaging (MRI) allows the detection of the three main signs of Rheumatoid Arthritis (RA) at higher sensitivities than available through conventional radiology. The rapid, accurate segmentation of bones is an essential preliminary step for quantitative diagnosis, erosion evaluation, and multi-temporal data fusion. In the present paper, a new, semi-automatic, 3D graph-based segmentation method to extract carpal bone data is proposed. The method is unsupervised, does not employ any a priori model or knowledge, and is adaptive to the individual variability of the acquired data. After selecting one source point inside the Region of Interest (ROI), a segmentation process is initiated, which consists of two automatic stages: a cost-labeling phase and a graph-cutting phase. The algorithm finds optimal paths based on a new cost function by creating a Minimum Path Spanning Tree (MPST). To extract the region, a cut of the obtained tree is necessary. A new criterion of the MPST-cut based on compactness shape factor was conceived and developed. The proposed approach is applied to a large database of 96 T1-weighted MR bone volumes. Performance quality is evaluated by comparing the results with gold-standard bone volumes manually defined by rheumatologists through the computation of metrics extracted from the confusion matrix. Furthermore, comparisons with the existing literature are carried out. The results show that this method is efficient and provides satisfactory performance for bone segmentation on low-field MR volumes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Machining of Some Difficult-to-Cut Materials with Rotary Cutting Tools

OpenAIRE

Stjernstoft, Tero

2004-01-01

Automobile and aero industries have an increasing interestin materials with improved mechanical properties. However, manyof these new materials are classified as difficult-to-cut withconventional tools. It is obvious that tools, cutting processesand cutting models has to be devel-oped parallel to materialsscience. In this thesis rotary cutting tools are tested as analternative toexpensive diamond or cubic bore nitridetools. Metal matrix composites mostly consist of a light metalalloy (such as...

High-speed fiber laser cutting of thick stainless steel for dismantling tasks

Science.gov (United States)

Shin, Jae Sung; Oh, Seong Yong; Park, Hyunmin; Chung, Chin-Man; Seon, Sangwoo; Kim, Taek-Soo; Lee, Lim; Choi, Byung-Seon; Moon, Jei-Kwon

2017-09-01

A high-speed fiber laser cutting technology of thick steels for dismantling tasks was achieved using a 6-kW fiber laser system. At first, a new cutting head for efficient cutting of thick steels was developed, which was composed by a collimator with a focal length of 160 mm and mirror-type focusing objects with a long focal length of 600 mm. The long focal length of the focusing object made it possible for the beam size to be small through the thick cutting material and the cutting efficiency was expected to increase compared with the short focal length. In addition, folding the beam facilitated the compact cutting head with a size of 160 mm (width) × 80 mm (height) × 640 mm (length) and a weight of 6.9 kg. In the cutting experiment, the laser beam was delivered to the cutting head by a 25-m long process fiber with a core diameter of 100 μm. The cutting performances were studied against the thicknesses of stainless steel plates. A maximum cutting speed of 72 mm/min was obtained for the 60-mm thick stainless steel plate cutting and the cut specimen showed an excellent kerf shape and a narrow kerf width. To the best of our knowledge, this cutting speed was higher than other previously reported results when cutting with a 6-kW laser power.

Minimizing waste (off-cuts using cutting stock model: The case of one dimensional cutting stock problem in wood working industry

Directory of Open Access Journals (Sweden)

Gbemileke A. Ogunranti

2016-09-01

Full Text Available Purpose: The main objective of this study is to develop a model for solving the one dimensional cutting stock problem in the wood working industry, and develop a program for its implementation. Design/methodology/approach: This study adopts the pattern oriented approach in the formulation of the cutting stock model. A pattern generation algorithm was developed and coded using Visual basic.NET language. The cutting stock model developed is a Linear Programming (LP Model constrained by numerous feasible patterns. A LP solver was integrated with the pattern generation algorithm program to develop a one - dimensional cutting stock model application named GB Cutting Stock Program. Findings and Originality/value: Applying the model to a real life optimization problem significantly reduces material waste (off-cuts and minimizes the total stock used. The result yielded about 30.7% cost savings for company-I when the total stock materials used is compared with the former cutting plan. Also, to evaluate the efficiency of the application, Case I problem was solved using two top commercial 1D-cutting stock software.  The results show that the GB program performs better when related results were compared. Research limitations/implications: This study round up the linear programming solution for the number of pattern to cut. Practical implications: From Managerial perspective, implementing optimized cutting plans increases productivity by eliminating calculating errors and drastically reducing operator mistakes. Also, financial benefits that can annually amount to millions in cost savings can be achieved through significant material waste reduction. Originality/value: This paper developed a linear programming one dimensional cutting stock model based on a pattern generation algorithm to minimize waste in the wood working industry. To implement the model, the algorithm was coded using VisualBasic.net and linear programming solver called lpsolvedll (dynamic

Aerated drilling cutting transport analysis in geothermal well

Science.gov (United States)

Wakhyudin, Aris; Setiawan, Deni; Dwi Marjuan, Oscar

2017-12-01

Aeratad drilling widely used for geothermal drilling especially when drilled into predicted production zone. Aerated drilling give better performance on preventing lost circulation problem, improving rate of penetration, and avoiding drilling fluid invasion to productive zone. While well is drilled, cutting is produced and should be carried to surface by drilling fluid. Hole problem, especially pipe sticking will occur while the cutting is not lifted properly to surface. The problem will effect on drilling schedule; non-productive time finally result more cost to be spent. Geothermal formation has different characteristic comparing oil and gas formation. Geothermal mainly has igneous rock while oil and gas mostly sedimentary rock. In same depth, formation pressure in geothermal well commonly lower than oil and gas well while formation temperature geothermal well is higher. While aerated drilling is applied in geothermal well, Igneous rock density has higher density than sedimentary rock and aerated drilling fluid is lighter than water based mud hence minimum velocity requirement to transport cutting is larger than in oil/gas well drilling. Temperature and pressure also has impact on drilling fluid (aerated) density. High temperature in geothermal well decrease drilling fluid density hence the effect of pressure and temperature also considered. In this paper, Aerated drilling cutting transport performance on geothermal well will be analysed due to different rock and drilling fluid density. Additionally, temperature and pressure effect on drilling fluid density also presented to merge.

Innovation Study for Laser Cutting of Complex Geometries with Paper Materials

Science.gov (United States)

Happonen, A.; Stepanov, A.; Piili, H.; Salminen, A.

Even though technology for laser cutting of paper materials has existed for over 30 years, it seems that results of applications of this technology and possibilities of laser cutting systems are not easily available. The aim of this study was to analyze the feasibility of the complex geometry laser cutting of paper materials and to analyze the innovation challenges and potential of current laser cutting technologies offer. This research studied the potential and possible challenges in applying CO2 laser cutting technology for cutting of paper materials in current supply chains trying to fulfil the changing needs of customer in respect of shape, fast response during rapid delivery cycle. The study is focused on examining and analyzing the different possibilities of laser cutting of paper material in application area of complex low volume geometry cutting. The goal of this case was to analyze the feasibility of the laser cutting from technical, quality and implementation points of view and to discuss availability of new business opportunities. It was noticed that there are new business models still available within laser technology applications in complex geometry cutting. Application of laser technology, in business-to-consume markets, in synergy with Internet service platforms can widen the customer base and offer new value streams for technology and service companies. Because of this, existing markets and competition has to be identified, and appropriate new and innovative business model needs to be developed. And to be competitive in the markets, models like these need to include the earning logic and the stages from production to delivery as discussed in the paper.

Tailor cutting of crystalline solar cells by laser micro jet

Science.gov (United States)

Bruckert, F.; Pilat, E.; Piron, P.; Torres, P.; Carron, B.; Richerzhagen, B.; Pirot, M.; Monna, R.

2012-03-01

Coupling a laser into a hair thin water micro jet (Laser Micro Jet, LMJ) for cutting applications offers a wide range of processes that are quite unique. As the laser beam is guided by internal reflections inside of a liquid cylinder, the cuts are naturally straight and do not reflect any divergence as otherwise occurs with an unguided laser beam. Furthermore, having a liquid media at the point of contact ensures a fast removal of heat and eventual debris ensuring clean cuts, which are free of any burrs. Many applications have indeed been developed for a large variety of materials, which are as different as e.g. diamond, silicon, aluminum, ceramic and hard metals. The photovoltaic industry has enjoyed in the last decades tremendous growth rates, which are still projected into the future. We focus here on the segment of Building Integrated PV (BIPV), which requests tailored solutions to actual buildings and not-one-fits-it-all standardized modules. Having the option to tailor cut solar cells opens a new field of BIPV applications. For the first time, finished crystalline solar cells have been LMJ cut into predetermined shapes. First results show that the cut is clean and neat. Preliminary solar performance measurements are positive. This opens a new avenue of tailored made modules instead of having to rely on the one-fits-alloy approach used so far.

Slice-push, formation of grooves and the scale effect in cutting.

Science.gov (United States)

Atkins, A G

2016-06-06

Three separate aspects of cutting are investigated which complement other papers on the mechanics of separation processes presented at this interdisciplinary Theo Murphy meeting. They apply in all types of cutting whether blades are sharp or blunt, and whether the material being cut is 'hard, stiff and strong' or 'soft, compliant and weak'. The first topic discusses why it is easier to cut when there is motion along (parallel to) the blade as well motion across (perpendicular to) the cutting edge, and the analysis is applied to optimization of blade geometries to produce minimum cutting forces and hence minimum damage to cut surfaces. The second topic concerns cutting with more than one edge with particular application to the formation of grooves in surfaces by hard pointed tools. The mechanics are investigated and applied to the topic of abrasive wear by hard particles. Traditional analyses say that abrasive wear resistance increases monotonically with the hardness of the workpiece, but we show that the fracture toughness of the surface material is also important, and that behaviour is determined by the toughness-to-hardness ratio rather than hardness alone. Scaling forms the third subject. As cutting is a branch of elasto-plastic fracture mechanics, cube-square energy scaling applies in which the important length scale is (ER/k (2)), where E is Young's modulus, R is the fracture toughness and k is the shear yield strength. Whether, in cutting, material is removed as ductile ribbons, as semi-ductile discontinuous chips, or by brittle 'knocking lumps out' is shown to depend on the depth of cut relative to this characteristic length parameter. Scaling in biology is called allometry and its relationship with engineering scaling is discussed. Some speculative predictions are made in relation to the action of teeth on food.

Cutting efficiency of Reciproc and waveOne reciprocating instruments.

Science.gov (United States)

Plotino, Gianluca; Giansiracusa Rubini, Alessio; Grande, Nicola M; Testarelli, Luca; Gambarini, Gianluca

2014-08-01

The aim of the present study was to evaluate the cutting efficiency of 2 new reciprocating instruments, Reciproc and WaveOne. Twenty-four new Reciproc R25 and 24 new WaveOne Primary files were activated by using a torque-controlled motor (Silver Reciproc) and divided into 4 groups (n = 12): group 1, Reciproc activated by Reciproc ALL program; group 2, Reciproc activated by WaveOne ALL program; group 3, WaveOne activated by Reciproc ALL program; and group 4, WaveOne activated by WaveOne ALL program. The device used for the cutting test consisted of a main frame to which a mobile plastic support for the handpiece is connected and a stainless steel block containing a Plexiglas block (inPlexiglass, Rome, Italy) against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1 mm. Means and standard deviations of each group were calculated, and data were statistically analyzed with 1-way analysis of variance and Bonferroni test (P cutting efficiency than WaveOne Primary for both the movements used (P cutting efficiency than WaveOne instruments used with their proper reciprocating motion (P .05). Reciproc instruments demonstrated statistically higher cutting efficiency than WaveOne instruments. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Numerical modelling of orthogonal cutting: application to woodworking with a bench plane

OpenAIRE

Nairn, John A.

2016-01-01

A numerical model for orthogonal cutting using the material point method was applied to woodcutting using a bench plane. The cutting process was modelled by accounting for surface energy associated with wood fracture toughness for crack growth parallel to the grain. By using damping to deal with dynamic crack propagation and modelling all contact between wood and the plane, simulations could initiate chip formation and proceed into steady-state chip propagation including chip curling. Once st...

Studies of the spectral and spatial characteristics of shock-induced luminescence from x-cut quartz

International Nuclear Information System (INIS)

Brannon, P.J.; Konrad, C.; Morris, R.W.; Jones, E.D.; Asay, J.R.

1983-01-01

Spatial and spectral studies of shock-induced luminescence from x-cut crystalline quartz as a function of stress level revealed the following information: Crystalline x-cut quartz has a threshold for emission near the dynamic yield point (about 6 GPa); the spatial distribution of the luminescence from x-cut quartz changes from an intersecting linear emission pattern to a uniform emission pattern as the stress level increases from 6 to 8 GPa; spectra from x-cut quartz are band-like rather than blackbody; crystalline x-cut quartz has emission peaks near 400 and 600 nm; a change in the 400-nm emission with time can be correlated to wave interaction times. A discussion of the luminous emission in terms of yielding and other physical mechanisms is given

Underwater cutting techniques developments

International Nuclear Information System (INIS)

Bach, F.-W.

1990-01-01

The primary circuit structures of different nuclear powerplants are constructed out of stainless steels, ferritic steels, plated ferritic steels and alloys of aluminium. According to the level of the specific radiation of these structures, it is necessary for dismantling to work with remote controlled cutting techniques. The most successful way to protect the working crew against exposure of radiation is to operate underwater in different depths. The following thermal cutting processes are more or less developed to work under water: For ferritic steels only - flame cutting; For ferritic steels, stainless steels, cladded steels and aluminium alloys - oxy-arc-cutting, arc-waterjet-cutting with a consumable electrode, arc-saw-cutting, plasma-arc-cutting and plasma-arc-saw. The flame cutting is a burning process, all the other processes are melt-cutting processes. This paper explains the different techniques, giving a short introduction of the theory, a discussion of the possibilities with the advantages and disadvantages of these processes giving a view into the further research work in this interesting field. (author)

Examination of optimum test conditions for a 3-point bending and cutting test to evaluate sound emission of wafer during deformation

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Erdem Carsanba

2018-04-01

Full Text Available The purpose of this study was to investigate optimum test conditions of acoustical-mechanical measurement of wafer analysed by Acoustic Envelope Detector attached to the Texture Analyser. Force-displacement and acoustic signals were simultaneously recorded applying two different methods (3-point bending and cutting test. In order to study acoustical-mechanical behaviour of wafers, the parameters “maximum sound pressure”, “total count peaks” and “mean sound value” were used and optimal test conditions of microphone position and test speed were examined. With a microphone position of 45° angle and 1 cm distance and at a low test speed of 0.5 mm/s wafers of different quality could be distinguished best. The angle of microphone did not have significant effect on acoustic results and the number of peaks of the force and acoustic signal decreased with increasing distance and test speed.

Investigation of wear land and rate of locally made HSS cutting tool

Science.gov (United States)

Afolalu, S. A.; Abioye, A. A.; Dirisu, J. O.; Okokpujie, I. P.; Ajayi, O. O.; Adetunji, O. R.

2018-04-01

Production technology and machining are inseparable with cutting operation playing important roles. Investigation of wear land and rate of cutting tool developed locally (C=0.56%) with an HSS cutting tool (C=0.65%) as a control was carried out. Wear rate test was carried out using Rotopol -V and Impact tester. The samples (12) of locally made cutting tools and one (1) sample of a control HSS cutting tool were weighed to get the initial weight and grit was fixed at a point for the sample to revolve at a specific time of 10 mins interval. Approach of macro transfer particles that involved mechanism of abrasion and adhesion which was termed as mechanical wear to handle abrasion adhesion processes was used in developing equation for growth wear at flank. It was observed from the wear test that best minimum wear rate of 1.09 × 10-8 and 2.053 × 10-8 for the tools developed and control were measured. MATLAB was used to simulate the wear land and rate under different conditions. Validated results of both the experimental and modeling showed that cutting speed has effect on wear rate while cutting time has predicted measure on wear land. Both experimental and modeling result showed best performances of tools developed over the control.

Axial and transverse tensile properties Zr-2.5Nb pressure tube off-cuts

International Nuclear Information System (INIS)

Shah, Priti K.; Dubey, J.S.; Shriwastaw, R.S.; Balakrishnan, K.S.; Anantharaman, S.; Chakravartty, J.K.

2011-01-01

Zr-2.5Nb alloys in cold worked and stress relieved (CWSR) condition serves as pressure boundary for hot coolant in Indian Pressurized Heavy Water Reactor (IPHWR). Due to both microstructural and crystallographic anisotropy, the mechanical properties in general and fracture behavior in particular are anisotropic for this material. To understand the anisotropic mechanical behavior of the Zr-2.5Nb pressure tubes of IPHWRs, tension tests were carried out on the RAPS-2 and KAPS-2 pressure tube off-cuts. Off-cuts are the small pieces cut from the two ends of a pressure tube before installing it into the PHWR. Miniature flat tensile specimens (without applying any flattening treatment to the pressure tube) of both longitudinal (or axial) and transverse orientation were fabricated from the off-cuts. Tension tests were carried out both at room temperature and 300 deg C. The transverse specimens showed higher strength and lower elongation than that of the axial ones. The back-end off-cuts showed higher strength compared to front-end off-cuts along axial direction whereas the same is not true for transverse direction specimens. One typical plot obtained in the testing of one of the off-cut is shown. The paper will discuss about the importance of the work carried out, test specimens, test method and results obtained in detail

Cut-Offs and Response Criteria for the Hospital Universitario La Princesa Index (HUPI and Their Comparison to Widely-Used Indices of Disease Activity in Rheumatoid Arthritis.

Directory of Open Access Journals (Sweden)

Isidoro González-Álvaro

Full Text Available To estimate cut-off points and to establish response criteria for the Hospital Universitario La Princesa Index (HUPI in patients with chronic polyarthritis.Two cohorts, one of early arthritis (Princesa Early Arthritis Register Longitudinal [PEARL] study and other of long-term rheumatoid arthritis (Estudio de la Morbilidad y Expresión Clínica de la Artritis Reumatoide [EMECAR] including altogether 1200 patients were used to determine cut-off values for remission, and for low, moderate and high activity through receiver operating curve (ROC analysis. The areas under ROC (AUC were compared to those of validated indexes (SDAI, CDAI, DAS28. ROC analysis was also applied to establish minimal and relevant clinical improvement for HUPI.The best cut-off points for HUPI are 2, 5 and 9, classifying RA activity as remission if ≤2, low disease activity if >2 and ≤5, moderate if >5 and <9 and high if ≥9. HUPI's AUC to discriminate between low-moderate activity was 0.909 and between moderate-high activity 0.887. DAS28's AUCs were 0.887 and 0.846, respectively; both indices had higher accuracy than SDAI (AUCs: 0.832 and 0.756 and CDAI (AUCs: 0.789 and 0.728. HUPI discriminates remission better than DAS28-ESR in early arthritis, but similarly to SDAI. The HUPI cut-off for minimal clinical improvement was established at 2 and for relevant clinical improvement at 4. Response criteria were established based on these cut-off values.The cut-offs proposed for HUPI perform adequately in patients with either early or long term arthritis.

Cut-Offs and Response Criteria for the Hospital Universitario La Princesa Index (HUPI) and Their Comparison to Widely-Used Indices of Disease Activity in Rheumatoid Arthritis.

Science.gov (United States)

González-Álvaro, Isidoro; Castrejón, Isabel; Ortiz, Ana M; Toledano, Esther; Castañeda, Santos; García-Vadillo, Alberto; Carmona, Loreto

2016-01-01

To estimate cut-off points and to establish response criteria for the Hospital Universitario La Princesa Index (HUPI) in patients with chronic polyarthritis. Two cohorts, one of early arthritis (Princesa Early Arthritis Register Longitudinal [PEARL] study) and other of long-term rheumatoid arthritis (Estudio de la Morbilidad y Expresión Clínica de la Artritis Reumatoide [EMECAR]) including altogether 1200 patients were used to determine cut-off values for remission, and for low, moderate and high activity through receiver operating curve (ROC) analysis. The areas under ROC (AUC) were compared to those of validated indexes (SDAI, CDAI, DAS28). ROC analysis was also applied to establish minimal and relevant clinical improvement for HUPI. The best cut-off points for HUPI are 2, 5 and 9, classifying RA activity as remission if ≤2, low disease activity if >2 and ≤5), moderate if >5 and <9 and high if ≥9. HUPI's AUC to discriminate between low-moderate activity was 0.909 and between moderate-high activity 0.887. DAS28's AUCs were 0.887 and 0.846, respectively; both indices had higher accuracy than SDAI (AUCs: 0.832 and 0.756) and CDAI (AUCs: 0.789 and 0.728). HUPI discriminates remission better than DAS28-ESR in early arthritis, but similarly to SDAI. The HUPI cut-off for minimal clinical improvement was established at 2 and for relevant clinical improvement at 4. Response criteria were established based on these cut-off values. The cut-offs proposed for HUPI perform adequately in patients with either early or long term arthritis.

Welding and cutting

International Nuclear Information System (INIS)

Drews, P.; Schulze Frielinghaus, W.

1978-01-01

This is a survey, with 198 literature references, of the papers published in the fields of welding and cutting within the last three years. The subjects dealt with are: weldability of the materials - Welding methods - Thermal cutting - Shaping and calculation of welded joints - Environmental protection in welding and cutting. (orig.) [de

Experimental study of the effect of gas nature on plasma arc cutting of mild steel

International Nuclear Information System (INIS)

Kavka, T; Mašláni, A; Hrabovský, M; Křenek, P; Stehrer, T; Pauser, H

2013-01-01

This paper is devoted to the experimental investigation of arc cutting of mild steel using plasmas generated in gas and liquid media. Due to different chemical compositions, the examined media have different thermophysical properties, which affect the properties of the generated plasma and cutting performance. The experiments are performed on 15 mm mild steel plates using commercial equipment at 60 A to approach real operation conditions in application areas. The studied gases are chosen according to recommendations of the world's leading manufacturers of arc cutting equipment for mild steel. Specific differences between plasma gases are discussed from the point of view of properties of the gas and the generated plasma, amount of removed material, kerf shape and overall energy balance of the cutting process. The paper describes the role of exothermic reaction of iron oxidation for oxygen cutting and explains its neglect for liquid cutting. This paper explains the potential of facilitating the cutting process by modification of the plasma gas chemical composition and flow rate. (paper)

On extracting heavy quark parameters from moments with cuts

International Nuclear Information System (INIS)

Bigi, I.I.; Uraltsev, N.

2004-01-01

We point out that the moments of the photon energy spectrum in B→X s +γ decays have a significant bias compared to the OPE expressions used to evaluate them, when a lower cut on the photon energy is imposed. This typically increases the value extracted for the apparent b quark mass by 70 MeV or more together with an even more dramatic reduction in the apparent value of the kinetic energy expectation value. These nonperturbative effects are exponential in the effective hardness of the transition, which is strongly lowered by high cuts, and do not reflect a breakdown of the 1/m b expansion itself. Similar effects in semileptonic b→c decays are briefly addressed. Accounting for the cut-related shifts brings different measurements into good agreement, when the OPE-based theory employs the 'robust' approach. We stress the utility of the second moment of E γ , once the aforementioned effects have been included

Restraining and neck cutting or stunning and neck cutting of veal calves.

Science.gov (United States)

Lambooij, E; van der Werf, J T N; Reimert, H G M; Hindle, V A

2012-05-01

Brain and heart activities were measured in 31 veal calves during restraining and rotating followed by neck cutting with or without stunning to evaluate welfare. After neck cutting correlation dimension analyses and %power of EEG beta wave fraction decreased gradually to lower values resulting in an induction of unconsciousness lasting on average 80s. Corneal reflex response ceased 135±57s after neck cutting. The CD scores and the %power of beta waves fell immediately after post-cut captive bolt and pre-cut electrical stunning to levels indicating unconsciousness. Heart rate in lairage increased upon entrance to the restrainer and again after rotation, heart rate variability decreased. Rotating the restrainer 90°, 120° or 180° compromised veal calf welfare and should be avoided. It is recommended to use post-cut captive bolt stunning or pre-cut electrical stunning inducing immediate unconsciousness. Copyright © 2011 Elsevier Ltd. All rights reserved.

An improved α-cut approach to transforming fuzzy membership function into basic belief assignment

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Yang Yi

2016-08-01

Full Text Available In practical applications, pieces of evidence originated from different sources might be modeled by different uncertainty theories. To implement the evidence combination under the Dempster–Shafer evidence theory (DST framework, transformations from the other type of uncertainty representation into the basic belief assignment are needed. α-Cut is an important approach to transforming a fuzzy membership function into a basic belief assignment, which provides a bridge between the fuzzy set theory and the DST. Some drawbacks of the traditional α-cut approach caused by its normalization step are pointed out in this paper. An improved α-cut approach is proposed, which can counteract the drawbacks of the traditional α-cut approach and has good properties. Illustrative examples, experiments and related analyses are provided to show the rationality of the improved α-cut approach.

Application of laser spot cutting on spring contact probe for semiconductor package inspection

Science.gov (United States)

Lee, Dongkyoung; Cho, Jungdon; Kim, Chan Ho; Lee, Seung Hwan

2017-12-01

A packaged semiconductor has to be electrically tested to make sure they are free of any manufacturing defects. The test interface, typically employed between a Printed Circuit Board and the semiconductor devices, consists of densely populated Spring Contact Probe (SCP). A standard SCP typically consists of a plunger, a barrel, and an internal spring. Among these components, plungers are manufactured by a stamping process. After stamping, plunger connecting arms need to be cut into pieces. Currently, mechanical cutting has been used. However, it may damage to the body of plungers due to the mechanical force engaged at the cutting point. Therefore, laser spot cutting is considered to solve this problem. The plunger arm is in the shape of a rectangular beam, 50 μm (H) × 90 μm (W). The plunger material used for this research is gold coated beryllium copper. Laser parameters, such as power and elapsed time, have been selected to study laser spot cutting. Laser material interaction characteristics such as a crater size, material removal zone, ablation depth, ablation threshold, and full penetration are observed. Furthermore, a carefully chosen laser parameter (Etotal = 1000mJ) to test feasibility of laser spot cutting are applied. The result show that laser spot cutting can be applied to cut SCP.

Study on Crystallographic Orientation Effect on Surface Generation of Aluminum in Nano-cutting.

Science.gov (United States)

Xu, Feifei; Fang, Fengzhou; Zhu, Yuanqing; Zhang, Xiaodong

2017-12-01

The material characteristics such as size effect are one of the most important factors that could not be neglected in cutting the material at nanoscale. The effects of anisotropic nature of single crystal materials in nano-cutting are investigated employing the molecular dynamics simulation. Results show that the size effect of the plastic deformation is based on different plastic carriers, such as the twin, stacking faults, and dislocations. The minimum uncut chip thickness is dependent on cutting direction, where even a negative value is obtained when the cutting direction is {110}. It also determines the material deformation and removal mechanism (e.g., shearing, extruding, and rubbing mechanism) with a decrease in uncut chip thickness. When material is deformed by shearing, the primary shearing zone expands from the stagnation point or the tip of stagnation zone. When a material is deformed by extruding and rubbing, the primary deformation zone almost parallels to the cutting direction and expands from the bottom of the cutting edge merging with the tertiary deformation zone. The generated surface quality relates to the crystallographic orientation and the minimum uncut chip thickness. The cutting directions of {110}, {110}, and {111}, whose minimum uncut chip thickness is relatively small, have better surface qualities compared to the other cutting direction.

Enhancement of low power CO2 laser cutting process for injection molded polycarbonate

Science.gov (United States)

Moradi, Mahmoud; Mehrabi, Omid; Azdast, Taher; Benyounis, Khaled Y.

2017-11-01

Laser cutting technology is a non-contact process that typically is used for industrial manufacturing applications. Laser cut quality is strongly influenced by the cutting processing parameters. In this research, CO2 laser cutting specifications have been investigated by using design of experiments (DOE) with considering laser cutting speed, laser power and focal plane position as process input parameters and kerf geometry dimensions (i.e. top and bottom kerf width, ratio of the upper kerf to lower kerf, upper heat affected zone (HAZ)) and surface roughness of the kerf wall as process output responses. A 60 Watts CO2 laser cutting machine is used for cutting the injection molded samples of polycarbonate sheet with the thickness of 3.2 mm. Results reveal that by decreasing the laser focal plane position and laser power, the bottom kerf width will be decreased. Also the bottom kerf width decreases by increasing the cutting speed. As a general result, locating the laser spot point in the depth of the workpiece the laser cutting quality increases. Minimum value of the responses (top kerf, heat affected zone, ratio of the upper kerf to lower kerf, and surface roughness) are considered as optimization criteria. Validating the theoretical results using the experimental tests is carried out in order to analyze the results obtained via software.

IMPORTANCE, Minimal Cut Sets and System Availability from Fault Tree Analysis

International Nuclear Information System (INIS)

Lambert, H. W.

1987-01-01

1 - Description of problem or function: IMPORTANCE computes various measures of probabilistic importance of basic events and minimal cut sets to a fault tree or reliability network diagram. The minimal cut sets, the failure rates and the fault duration times (i.e., the repair times) of all basic events contained in the minimal cut sets are supplied as input data. The failure and repair distributions are assumed to be exponential. IMPORTANCE, a quantitative evaluation code, then determines the probability of the top event and computes the importance of minimal cut sets and basic events by a numerical ranking. Two measures are computed. The first describes system behavior at one point in time; the second describes sequences of failures that cause the system to fail in time. All measures are computed assuming statistical independence of basic events. In addition, system unavailability and expected number of system failures are computed by the code. 2 - Method of solution: Seven measures of basic event importance and two measures of cut set importance can be computed. Birnbaum's measure of importance (i.e., the partial derivative) and the probability of the top event are computed using the min cut upper bound. If there are no replicated events in the minimal cut sets, then the min cut upper bound is exact. If basic events are replicated in the minimal cut sets, then based on experience the min cut upper bound is accurate if the probability of the top event is less than 0.1. Simpson's rule is used in computing the time-integrated measures of importance. Newton's method for approximating the roots of an equation is employed in the options where the importance measures are computed as a function of the probability of the top event, and a shell sort puts the output in descending order of importance

MOCUS, Minimal Cut Sets and Minimal Path Sets from Fault Tree Analysis

International Nuclear Information System (INIS)

Fussell, J.B.; Henry, E.B.; Marshall, N.H.

1976-01-01

1 - Description of problem or function: From a description of the Boolean failure logic of a system, called a fault tree, and control parameters specifying the minimal cut set length to be obtained MOCUS determines the system failure modes, or minimal cut sets, and the system success modes, or minimal path sets. 2 - Method of solution: MOCUS uses direct resolution of the fault tree into the cut and path sets. The algorithm used starts with the main failure of interest, the top event, and proceeds to basic independent component failures, called primary events, to resolve the fault tree to obtain the minimal sets. A key point of the algorithm is that an and gate alone always increases the number of path sets; an or gate alone always increases the number of cut sets and increases the size of path sets. Other types of logic gates must be described in terms of and and or logic gates. 3 - Restrictions on the complexity of the problem: Output from MOCUS can include minimal cut and path sets for up to 20 gates

Dynamic characterization of the cutting conditions in dry turning

Energy Technology Data Exchange (ETDEWEB)

Serra, R [ENI Val de Loire, Universite Francois Rabelais de Tours, Laboratoire de Mecanique et Rheologie, E.A. 2640, B.P. 3410, 41034 Blois Cedex (France); Chibane, H [Universite Francois Rabelais, Laboratoire de Mecanique et Rheologie, E.A. 2640, B.P. 3410, 41034 Blois Cedex (France); Leroy, R, E-mail: roger.serra@univ-tours.f [Universite Francois Rabelais, Polytech' Tours, Laboratoire de Mecanique et Rheologie, E.A. 2640, 7 Avenue Marcel Dassault, 37200 Tours (France)

2009-08-01

Machining instability in the form of violent vibrations or chatter is a physical process characterized by extreme cutting force at the cutting point. The process has very negative impact on machine integrity, tool life, surface quality and dimensional accuracy. Thus it could significantly compromise productivity and manufacturing quality. In the present paper, the importance of characterization and identification of dynamic instability in dry turning operation are shown. The stability behaviour of machine vibration or chatter has been examined and the various relevant parameters are studied and discuted. For chatter detection and identification of the transition between stable and unstable states, different methods are used. Results obtained proof the accuracy of these methods.

Trend of CO2 laser cutting; Saikin no CO2 laser setsudan

Energy Technology Data Exchange (ETDEWEB)

Fujii, T.; Sano, Y.; Nagahori, M. [Tanaka Engineering Works Ltd., Saitama (Japan)

1998-08-01

This paper describes CO2 laser cutting of medium thick plates. Carbon dioxide laser is mainly used for laser generators. The generation efficiency of CO2 laser is 5 to 15% which is higher than that of the other lasers. Ninety percent of the usage is for cutting, piercing and welding. Laser cutter having a separated generator with a power from 3 to 6 kW is often used for cutting medium thick plates. The recent trend of new cutting technology is introduced. When power is increased from 3 kW to 6 kW without using oxygen as assist gas, the cutting thickness of stainless steel plate increased into 1.5 times, and the cutting speed increased into 1.5 to 2 times. For the soft steel members with black coating in which the power-up effects have not been obtained, the cutting speed, quality of cutting surface and cutting stability were improved by introducing new technology. Piercing time has been reduced by developing a method by which pulse generation is changed during piercing and a method by which piercing is conducted by irradiating the maximum power of continuous generation. Cutting quality with high accuracy has been realized by developing light weight generator and high performance NC unit. 10 figs.

Paper Cuts.

Science.gov (United States)

Greene, Lisa A.

1990-01-01

Describes how to create paper cuts and suggests the most appropriate materials for young children that give good quality results. Describes the methods the author, a professional artist, uses to assemble her own paper cuts and how these can be adopted by older students. (KM)

Wet cutting

Energy Technology Data Exchange (ETDEWEB)

Hole, B. [IMC Technical Services (United Kingdom)

1999-08-01

Continuous miners create dust and methane problems in underground coal mining. Control has usually been achieved using ventilation techniques as experiments with water based suppression have led to flooding and electrical problems. Recent experience in the US has led to renewed interest in wet head systems. This paper describes tests of the Hydraphase system by IMC Technologies. Ventilation around the cutting zone, quenching of hot ignition sources, dust suppression, the surface trial gallery tests, the performance of the cutting bed, and flow of air and methane around the cutting head are reviewed. 1 ref., 2 figs., 2 photos.

Fundamentals of cutting.

Science.gov (United States)

Williams, J G; Patel, Y

2016-06-06

The process of cutting is analysed in fracture mechanics terms with a view to quantifying the various parameters involved. The model used is that of orthogonal cutting with a wedge removing a layer of material or chip. The behaviour of the chip is governed by its thickness and for large radii of curvature the chip is elastic and smooth cutting occurs. For smaller thicknesses, there is a transition, first to plastic bending and then to plastic shear for small thicknesses and smooth chips are formed. The governing parameters are tool geometry, which is principally the wedge angle, and the material properties of elastic modulus, yield stress and fracture toughness. Friction can also be important. It is demonstrated that the cutting process may be quantified via these parameters, which could be useful in the study of cutting in biology.

Object segmentation using graph cuts and active contours in a pyramidal framework

Science.gov (United States)

Subudhi, Priyambada; Mukhopadhyay, Susanta

2018-03-01

Graph cuts and active contours are two very popular interactive object segmentation techniques in the field of computer vision and image processing. However, both these approaches have their own well-known limitations. Graph cut methods perform efficiently giving global optimal segmentation result for smaller images. However, for larger images, huge graphs need to be constructed which not only takes an unacceptable amount of memory but also increases the time required for segmentation to a great extent. On the other hand, in case of active contours, initial contour selection plays an important role in the accuracy of the segmentation. So a proper selection of initial contour may improve the complexity as well as the accuracy of the result. In this paper, we have tried to combine these two approaches to overcome their above-mentioned drawbacks and develop a fast technique of object segmentation. Here, we have used a pyramidal framework and applied the mincut/maxflow algorithm on the lowest resolution image with the least number of seed points possible which will be very fast due to the smaller size of the image. Then, the obtained segmentation contour is super-sampled and and worked as the initial contour for the next higher resolution image. As the initial contour is very close to the actual contour, so fewer number of iterations will be required for the convergence of the contour. The process is repeated for all the high-resolution images and experimental results show that our approach is faster as well as memory efficient as compare to both graph cut or active contour segmentation alone.

Performance Evaluation of Cutting Fluids Developed from Fixed Oils

Directory of Open Access Journals (Sweden)

Emmanuel Ogo ONCHE

2007-01-01

Full Text Available In this work, different cutting fluid emulsions of about 10% concentration were developed from fixed oils and the performance of each of the developed cutting fluid was evaluated by a direct comparison with as purchased conventional cutting fluid (control sample, using the ability of each sample to effectively perform as coolant and lubricant during machining operation as determinant. In the evaluation process, straight turning operation on lathe machine at various speeds, but equal time intervals of 10 minutes was used with a 2 mm/min feed rate. It was found that cutting fluid developed from groundnut oil (Sample B performed best as coolant at all experimented speeds, with maximum temperature of 60.5° C at the working zone as against 71.39° C observed for the Control (Sample A. The viscosity 10.76 cSt of Sample B was however, higher than those of Samples A (4.79 cSt and C (6.20 cSt. It was recommended that further work be done to synergize Samples B and C and the cooling effectiveness of the hybridized cutting fluid on the tool-chip interphase, as well as its lubricity be evaluated.

Accuracy of the WHO’s body mass index cut-off points to measure gender- and age-specific obesity in middle-aged adults living in the city of Rio de Janeiro, Brazil

Directory of Open Access Journals (Sweden)

Wollner Materko

2017-09-01

Full Text Available Introduction. Obesity is defined by the World Health Organization (WHO as a disease characterized by the excessive accumulation of body fat. Obesity is considered a public health problem, leading to serious social, psychological and physical problems. However, the appropriate cut-off point of body mass index (BMI based on body fat percentage (BF% for classifying an individual as obese in middle-aged adults living in Rio de Janeiro remains unclear. Materials and methods. This was a prospective cross-sectional study comprising of 856 adults (413 men and 443 women living in Rio de Janeiro, Brazil ranging from 30-59 years of age. The data were collected over a two year period (2010-2011, and all participants were underwent anthropometric evaluation. The gold standard was the percentage of body fat estimated by bioelectrical impedance analysis. The optimal sensitivity and specificity were attained by adjusting BMI cut-off values to predict obesity based on the WHO criteria: BF% >25% in men and >35% in women, according to the receiver operating characteristic curve (ROC analysis adjusted for age and for the whole group.Results. The BMI cut-offs for predicting BF% were 29.9 kg/m2 in men and 24.9 kg/m2 in women. Conclusions. The BMI that corresponded to a BF% previously defining obesity was similar to that of other Western populations for men but not for women. Furthermore, gender and age specific cut-off values are recommended in this population.

Influence of leaf retention on cutting propagation of Lavandula dentata L.

Directory of Open Access Journals (Sweden)

Claudine Maria de Bona

2010-08-01

Full Text Available Vegetative propagation of lavender offers several advantages over sexual propagation, among them crop homogeneity and yield of higher quality essential oil. However, Lavandula species have been propagated mostly by seeds and are said to be recalcitrant to rooting when propagated by cuttings. During cutting propagation, one of the important variables that influence the rooting capacity of cuttings is the leaf retention. The objective of this work was to evaluate the influence of leaf retention on rooting of L. dentata cuttings. Apical cuttings of L. dentata of 10 cm in length, keeping approximately 1/3, 1/2 or 2/3 of their leaves were planted in commercial substrate Plantmax HT® under intermittent mist. After two months, averages of root number, length of the longest root, root fresh and dry weights, and the survival percentage were evaluated. Root length and fresh weight were statistically greater with 2/3 of leaf retention and when fewer leaves were kept on the cuttings, lower means of root dry weight was observed. Under the conditions applied in this study, greater leaf retention was better for rooting of L. dentata cuttings.

Device for cutting protrusions

Science.gov (United States)

Bzorgi, Fariborz M [Knoxville, TN

2011-07-05

An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

Experimental research on the durability cutting tools for cutting-off steel profiles

Directory of Open Access Journals (Sweden)

Cristea Alexandru

2017-01-01

Full Text Available The production lines used for manufacturing U-shaped profiles are very complex and they must have high productivity. One of the most important stages of the fabrication process is the cutting-off. This paper presents the experimental research and analysis of the durability of the cutting tools used for cutting-off U-shaped metal steel profiles. The results of this work can be used to predict the durability of the cutting tools.

Subclinical ketosis in post-partum dairy cows fed a predominantly pasture-based diet: defining cut-points for diagnosis using concentrations of beta-hydroxybutyrate in blood and determining prevalence.

Science.gov (United States)

Compton, C W R; Young, L; McDougall, S

2015-09-01

Firstly, to define, in dairy cows in the first 5 weeks post-calving fed a predominantly pasture-based diet, cut-points of concentrations of beta-hydroxybutyrate (BHBA) in blood, above which there were associations with purulent vaginal discharge (PVD), reduced pregnancy rates (PR) and decreased milk production, in order to better define subclinical ketosis (SCK) in such cattle; and secondly, to determine the prevalence, incidence and risk factors for SCK. An observational field study was conducted in 565 cows from 15 spring-calving and predominantly pasture-fed dairy herds in two regions of New Zealand during the 2010- 2011 dairy season. Within each herd, a cohort of randomly selected cows (approximately 40 per herd) was blood sampled to determine concentrations of BHBA on six occasions at weekly intervals starting within 5 days of calving. The key outcome variables were the presence/absence of PVD at 5 weeks post-calving, PR after 6 weeks (6-week PR) and after the completion of the breeding season (final PR), and mean daily milk solids production. Two cut-points for defining SCK were identified: firstly concentration of BHBA in blood≥1.2 mmol/L within 5 days post-calving, which was associated with an increased diagnosis of PVD (24 vs. 8%); and secondly concentration of BHBA in blood≥1.2 mmol/L at any stage within 5 weeks post-calving, which was associated with decreased 6-week PR (78 vs. 85%). The mean herd-level incidence of SCK within 5 weeks post-calving was 68 (min 12; max 100)% and large variations existed between herds in peak prevalence of SCK and the interval post-calving at which such peaks occurred. Cows>8 years of age and cows losing body condition were at increased risk of SCK within 5 weeks of calving. Cows with concentration of BHBA in blood≥1.2 mmol/L in early lactation had a higher risk of PVD and lower 6-week PR. Cow and herd-level prevalence of SCK varied widely in early lactation. Subclinical ketosis is common and is significantly

The membrane may be an important factor in browning of fresh-cut pear.

Science.gov (United States)

Li, Zhenghong; Zhang, Yuxing; Ge, Huibo

2017-09-01

Surface browning is an important cause of deterioration of fresh-cut fruit during postharvest handling. In this paper, four pear cultivars with different extents of natural browning were selected to analyse the factors involved in browning. The main results are as follows: the lipoxygenase (LOX) activity of 'Mantianhong' and 'Yali' pears was higher accompanied by a stronger degree of browning, while the LOX activity in 'Xueqing' and 'Xinli 7' pears was lower, with less browning. A higher unsaturated fatty acid ratio of pear resulted in reduced browning. The cell membranes disappeared 30min after being cut in 'Mantianhong' pear, which browns easily; however, the cell membranes were still intact 30min after being cut in 'Xueqing' pear, which does not brown easily. Therefore, it can be assumed that the stability of the cell membrane plays an important role in inhibiting browning of fresh-cut pears. Copyright © 2017. Published by Elsevier Ltd.

Gradual cut detection using low-level vision for digital video

Science.gov (United States)

Lee, Jae-Hyun; Choi, Yeun-Sung; Jang, Ok-bae

1996-09-01

Digital video computing and organization is one of the important issues in multimedia system, signal compression, or database. Video should be segmented into shots to be used for identification and indexing. This approach requires a suitable method to automatically locate cut points in order to separate shot in a video. Automatic cut detection to isolate shots in a video has received considerable attention due to many practical applications; our video database, browsing, authoring system, retrieval and movie. Previous studies are based on a set of difference mechanisms and they measured the content changes between video frames. But they could not detect more special effects which include dissolve, wipe, fade-in, fade-out, and structured flashing. In this paper, a new cut detection method for gradual transition based on computer vision techniques is proposed. And then, experimental results applied to commercial video are presented and evaluated.

Teaching learning algorithm based optimization of kerf deviations in pulsed Nd:YAG laser cutting of Kevlar-29 composite laminates

Science.gov (United States)

Gautam, Girish Dutt; Pandey, Arun Kumar

2018-03-01

Kevlar is the most popular aramid fiber and most commonly used in different technologically advanced industries for various applications. But the precise cutting of Kevlar composite laminates is a difficult task. The conventional cutting methods face various defects such as delamination, burr formation, fiber pullout with poor surface quality and their mechanical performance is greatly affected by these defects. The laser beam machining may be an alternative of the conventional cutting processes due to its non-contact nature, requirement of low specific energy with higher production rate. But this process also faces some problems that may be minimized by operating the machine at optimum parameters levels. This research paper examines the effective utilization of the Nd:YAG laser cutting system on difficult-to-cut Kevlar-29 composite laminates. The objective of the proposed work is to find the optimum process parameters settings for getting the minimum kerf deviations at both sides. The experiments have been conducted on Kevlar-29 composite laminates having thickness 1.25 mm by using Box-Benkhen design with two center points. The experimental data have been used for the optimization by using the proposed methodology. For the optimization, Teaching learning Algorithm based approach has been employed to obtain the minimum kerf deviation at bottom and top sides. A self coded Matlab program has been developed by using the proposed methodology and this program has been used for the optimization. Finally, the confirmation tests have been performed to compare the experimental and optimum results obtained by the proposed methodology. The comparison results show that the machining performance in the laser beam cutting process has been remarkably improved through proposed approach. Finally, the influence of different laser cutting parameters such as lamp current, pulse frequency, pulse width, compressed air pressure and cutting speed on top kerf deviation and bottom kerf

Comparison of two cut-to-length harvesting systems operating in eastern hardwoods

Science.gov (United States)

Chris B. LeDoux; Niel K. Huyler

2001-01-01

We compared production rates, operating costs, and break-even points (BEP) for small and large cut-to-length (CTL) harvesting systems operating at several machine utilization rates (MUR) in mixed hardwood and softwood stands in Vermont.

The Cutting Process, Chips and Cutting Forces in Machining CFRP

DEFF Research Database (Denmark)

Koplev, A.; Lystrup, Aage; Vorm, T.

1983-01-01

The cutting of unidirectional CFRP, perpendicular as well as parallel to the fibre orientation, is examined. Shaping experiments, ‘quick-stop’ experiments, and a new chip preparation technique are used for the investigation. The formation of the chips, and the quality of the machined surface...... is discussed. The cutting forces parallel and perpendicular to the cutting direction are measured for various parameters, and the results correlated to the formation of chips and the wear of the tool....

Feedback dew-point sensor utilizing optimally cut plastic optical fibres

Science.gov (United States)

Hadjiloucas, S.; Irvine, J.; Keating, D. A.

2000-01-01

A plastic optical fibre reflectance sensor that makes full use of the critical angle of the fibres is implemented to monitor dew formation on a Peltier-cooled reflector surface. The optical configuration permits isolation of optoelectronic components from the sensing head and better light coupling between the reflector and the detecting fibre, giving a better signal of the onset of dew formation on the reflector. Continuous monitoring of the rate of change in reflectance as well as the absolute reflectance signals, the use of a novel polymethyl-methacrylate-coated hydrophobic film reflector on the Peltier element and the application of feedback around the point of dew formation, further reduces the possibility of contamination of the sensor head. Under closed-loop operation, the sensor is capable of cycling around the point of dew formation at a frequency of 2.5 Hz.

Bi-objective branch-and-cut algorithms

DEFF Research Database (Denmark)

Gadegaard, Sune Lauth; Ehrgott, Matthias; Nielsen, Lars Relund

Most real-world optimization problems are of a multi-objective nature, involving objectives which are conflicting and incomparable. Solving a multi-objective optimization problem requires a method which can generate the set of rational compromises between the objectives. In this paper, we propose...... are strengthened by cutting planes. In addition, we suggest an extension of the branching strategy "Pareto branching''. Extensive computational results obtained for the bi-objective single source capacitated facility location problem prove the effectiveness of the algorithms....... and compares it to an upper bound set. The implicit bound set based algorithm, on the other hand, fathoms branching nodes by generating a single point on the lower bound set for each local nadir point. We outline several approaches for fathoming branching nodes and we propose an updating scheme for the lower...

Remote Fiber Laser Cutting System for Dismantling Glass Melter - 13071

Energy Technology Data Exchange (ETDEWEB)

Mitsui, Takashi; Miura, Noriaki [IHI Corporation, 1 Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa (Japan); Oowaki, Katsura; Kawaguchi, Isao [IHI Inspection and Instrumentation Co., Ltd, 1 Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa (Japan); Miura, Yasuhiko; Ino, Tooru [Japan Nuclear Fuel Limited, 4-108, Aza Okitsuke, Oaza Obuchi, Rokkasho-Mura, Kamikita-gun, Aomori (Japan)

2013-07-01

Since 2008, the equipment for dismantling the used glass melter has been developed in High-level Liquid Waste (HLW) Vitrification Facility in the Japanese Rokkasho Reprocessing Plant (RRP). Due to the high radioactivity of the glass melter, the equipment requires a fully-remote operation in the vitrification cell. The remote fiber laser cutting system was adopted as one of the major pieces of equipment. An output power of fiber laser is typically higher than other types of laser and so can provide high-cutting performance. The fiber laser can cut thick stainless steel and Inconel, which are parts of the glass melter such as casings, electrodes and nozzles. As a result, it can make the whole of the dismantling work efficiently done for a shorter period. Various conditions of the cutting test have been evaluated in the process of developing the remote fiber cutting system. In addition, the expected remote operations of the power manipulator with the laser torch have been fully verified and optimized using 3D simulations. (authors)

Analysis of changes in paper cutting forces during the cutting cycle in single-knife guillotine

OpenAIRE

Rusin, Agnieszka; Petriaszwili, Georgij

2013-01-01

Paper presents the results of changes in the three components of cutting forces of paper stacks cutting during the cutting cycle in single-knife guillotine. The changes of the three components of cutting force at different stages of cutting cycle were analyzed.

Specific cut-off points for waist circumference and waist-to-height ratio as predictors of cardiometabolic risk in Black subjects: a cross-sectional study in Benin and Haiti

Directory of Open Access Journals (Sweden)

EL Mabchour A

2015-10-01

Full Text Available Asma EL Mabchour,1 Hélène Delisle,1 Colette Vilgrain,2 Philippe Larco,2 Roger Sodjinou,3 Malek Batal1 1Transition Nutritionnelle (TRANSNUT, WHO Collaborating Centre on Nutrition Changes and Development, Department of Nutrition, Faculty of Medicine, University of Montreal, Montreal, QC, Canada; 2Haitian Foundation for Diabetes and Cardiovascular Diseases (FHADIMAC, Port-au-Prince, Haiti; 3West Africa Health Organization (WAHO, Bobo-Dioulasso, Burkina Faso Purpose: Waist circumference (WC and waist-to-height ratio (WHtR are widely used as indicators of abdominal adiposity and the cut-off values have been validated primarily in Caucasians. In this study we identified the WC and WHtR cut-off points that best predicted cardiometabolic risk (CMR in groups of African (Benin and African ancestry (Haiti Black subjects. Methods: This cross-sectional study included 452 apparently healthy subjects from Cotonou (Benin and Port-au-Prince (Haiti, 217 women and 235 men from 25 to 60 years. CMR biomarkers were the metabolic syndrome components. Additional CMR biomarkers were a high atherogenicity index (total serum cholesterol/high density lipoprotein cholesterol ≥4 in women and ≥5 in men; insulin resistance set at the 75th percentile of the calculated Homeostasis Model Assessment index (HOMA-IR; and inflammation defined as high-sensitivity C-reactive protein (hsCRP concentrations between 3 and 10 mg/L. WC and WHtR were tested as predictors of two out of the three most prevalent CMR biomarkers. Receiver operating characteristic (ROC curves, Youden's index, and likelihood ratios were used to assess the performance of specific WC and WHtR cut-offs. Results: High atherogenicity index (59.5%, high blood pressure (23.2%, and insulin resistance (25% by definition were the most prevalent CMR biomarkers in the study groups. WC and WHtR were equally valid as predictors of CMR. Optimal WC cut-offs were 80 cm and 94 cm in men and women, respectively, which is exactly

A PFC3D-based numerical simulation of cutting load for lunar rock simulant and experimental validation

Science.gov (United States)

Li, Peng; Jiang, Shengyuan; Tang, Dewei; Xu, Bo

2017-05-01

For sake of striking a balance between the need of drilling efficiency and the constrains of power budget on the moon, the penetrations per revolution of drill bit are generally limited in the range around 0.1 mm, and besides the geometric angle of the cutting blade need to be well designed. This paper introduces a simulation approach based on PFC3D (particle flow code 3 dimensions) for analyzing the cutting load feature on lunar rock simulant, which is derived from different geometric-angle blades with a small cutting depth. The mean values of the cutting force of five blades in the survey region (four on the boundary points and one on the center point) are selected as the macroscopic responses of model. The method of experimental design which includes Plackett-Burman (PB) design and central composite design (CCD) method is adopted in the matching procedure of microparameters in PFC model. Using the optimization method of enumeration, the optimum set of microparameters is acquired. Then, the experimental validation is implemented by using other twenty-five blades with different geometric angles, and the results from both simulations and laboratory tests give fair agreements. Additionally, the rock breaking process cut by different blades are quantified from simulation analysis. This research provides the theoretical support for the refinement of the rock cutting load prediction and the geometric design of cutting blade on the drill bit.

Bacteriological Evaluation Of Pre-Cut Fruits Sold In Kano Metropolis ...

African Journals Online (AJOL)

One hundred and fifty (150) pre-cut fruit samples comprising of Pineapples (50), Paw-paw (50) and Watermelon (50) at the point of stand retail outlets were tested by standard bacteriological methods to determine bacterial contamination of the fruits. Out of these 150 examined 136 (90.67%) were contaminated with bacteria.

Cutting and Self-Harm

Science.gov (United States)

... Your feelings Feeling sad Cutting and self-harm Cutting and self-harm Self-harm, sometimes called self- ... There are many types of self-injury, and cutting is one type that you may have heard ...

Cooking frozen and thawed roasts: beef, pork, and lamb cuts.

Science.gov (United States)

Fulton, C; Davis, C

1975-09-01

Cooking time, yield, and palatability of paired beef, pork, and lamb roasts cooked from the frozen and thawed states were compared. Cooking time for all roasts averaged from 3 to 22 min. per pound longer for meat cooked from the frozen state. The longer cooking time from the frozen state. The longer cooking time from the frozen state was greater for roasts with a large amount of bone and for cuts cooked by braising than for less bony roasts and cuts cooked by roasting. Except for thawed beef rump roasts, which had a higher yield of cooked lean meat, yield of cooked lean meat from the various cuts of beef, pork, and lamb was not affected by the state at the start of cooking. Collectively, all pork roasts had a higher yield of cooked lean meat when cooked from the frozen state. Juiciness and natural flavor of the roasts were not affected by the state at the start of cooking. Lamb leg and rib roasts were more tender when cooked from the thawed state.

Integration of Small-Diameter Wood Harvesting in Early Thinnings using the Two pile Cutting Method

Energy Technology Data Exchange (ETDEWEB)

Kaerhae, Kalle (Metsaeteho Oy, P.O. Box 101, FI-00171 Helsinki (Finland))

2008-10-15

Metsaeteho Oy studied the integrated harvesting of industrial roundwood (pulpwood) and energy wood based on a two-pile cutting method, i.e. pulpwood and energy wood fractions are stacked into two separate piles when cutting a first-thinning stand. The productivity and cost levels of the integrated, two-pile cutting method were determined, and the harvesting costs of the two-pile method were compared with those of conventional separate wood harvesting methods. In the time study, when the size of removal was 50 dm3, the productivity in conventional whole-tree cutting was 6% higher than in integrated cutting. With a stem size of 100 dm3, the productivity in whole-tree cutting was 7% higher than in integrated cutting. The results indicated, however, that integrated harvesting based on the two-pile method enables harvesting costs to be decreased to below the current cost level of separate pulpwood harvesting in first thinning stands. The greatest cost-saving potential lies in small-sized first thinnings. The results showed that, when integrated wood harvesting based on the two-pile method is applied, the removals of both energy wood and pulpwood should be more than 15-20 m3/ha at the harvesting sites in order to achieve economically viable integrated procurement

Wear mechanism of CBN cutting tool during high-speed machining of mold steel

International Nuclear Information System (INIS)

Farhat, Z.N.

2003-01-01

Wear behavior of cubic boron nitride (CBN) cutting tool when cutting P20 tool steel was investigated. Oblique cutting tests were performed on a CNC lathe using five speeds, namely, 240, 600 and 1000 m min -1 . The CBN cutting tools were found to be superior to tungsten carbide (WC) tools. Fourfold increase in productivity and significant reduction in chipping and cratering was achieved for CBN as compared to WC. Wear, as the width of the wear land (VB), was monitored at selected time intervals; furthermore, topography of worn surfaces was performed, using a profilometer. Wear characterization of the rake and the flank surfaces as well as of the collected chips was conducted using a scanning electron microscopy (SEM), backscattered electron imaging and energy depressive X-ray (EDX). It was found that deformation in the chips occurs by localized shear deformation and the dominant wear mechanism at all speeds used was identified to be diffusive wear. At a 1000 m min -1 cutting speed, a secondary wear mechanism was identified, which is melt wear, i.e., formation of low melting point Cr and Mn compounds with the tool material and the subsequent ejection from the cutting zone

On Permuting Cut with Contraction

OpenAIRE

Borisavljevic, Mirjana; Dosen, Kosta; Petric, Zoran

1999-01-01

The paper presents a cut-elimination procedure for intuitionistic propositional logic in which cut is eliminated directly, without introducing the multiple-cut rule mix, and in which pushing cut above contraction is one of the reduction steps. The presentation of this procedure is preceded by an analysis of Gentzen's mix-elimination procedure, made in the perspective of permuting cut with contraction. It is also shown that in the absence of implication, pushing cut above contraction doesn't p...

Laser cutting: industrial relevance, process optimization, and laser safety

Science.gov (United States)

Haferkamp, Heinz; Goede, Martin; von Busse, Alexander; Thuerk, Oliver

1998-09-01

Compared to other technological relevant laser machining processes, up to now laser cutting is the application most frequently used. With respect to the large amount of possible fields of application and the variety of different materials that can be machined, this technology has reached a stable position within the world market of material processing. Reachable machining quality for laser beam cutting is influenced by various laser and process parameters. Process integrated quality techniques have to be applied to ensure high-quality products and a cost effective use of the laser manufacturing plant. Therefore, rugged and versatile online process monitoring techniques at an affordable price would be desirable. Methods for the characterization of single plant components (e.g. laser source and optical path) have to be substituted by an omnivalent control system, capable of process data acquisition and analysis as well as the automatic adaptation of machining and laser parameters to changes in process and ambient conditions. At the Laser Zentrum Hannover eV, locally highly resolved thermographic measurements of the temperature distribution within the processing zone using cost effective measuring devices are performed. Characteristic values for cutting quality and plunge control as well as for the optimization of the surface roughness at the cutting edges can be deducted from the spatial distribution of the temperature field and the measured temperature gradients. Main influencing parameters on the temperature characteristic within the cutting zone are the laser beam intensity and pulse duration in pulse operation mode. For continuous operation mode, the temperature distribution is mainly determined by the laser output power related to the cutting velocity. With higher cutting velocities temperatures at the cutting front increase, reaching their maximum at the optimum cutting velocity. Here absorption of the incident laser radiation is drastically increased due to

Model for Reggeon-Pomeranchukon cuts

International Nuclear Information System (INIS)

Chia, S.

1977-01-01

A model is presented for calculating Reggeon-Pomeranchukon cuts, making use explicitly of the Mandelstam diagram. External spins are treated in a natural way. Calculation for the general case is outlined and it is shown that in practical application the cut can be calculated in a standard way. Cuts associated with the exchanges of π, rho, B, and A 2 are considered, and characteristics of the RP cuts, as well as the structure functions, are extracted and discussed. It is found that the model differs considerably from the absorption model. Two suppression schemes are operative which control the magnitudes of cut contributions to amplitudes with ''naturality'' opposite to the Reggeon. The πP cut is found to be a unique case because of the smallness of the pion mass. In general, the RP cuts are self-conspiratorial. At very high energies, all cuts, except πP cut, exhibit quasifactorization

Body mass index and waist-to-height ratio cut-offs as predictors of high blood pressure in adolescents

Directory of Open Access Journals (Sweden)

Kurnia Febriana

2015-04-01

Full Text Available Background: Obesity is associated with increased risk for high blood pressure (BP. Although a routine BP measurement is indicated for all children visiting pediatric practice, recognition of children particularly at risk may save times. The aim of this study was to assess the cut-off point for body mass index (BMI and waist-to-height ratio (WHtR to predict high BP in adolescents. Methods: We conducted a cross-sectional study on 928 children aged 11 to 16 years in Yogyakarta. BP were measured using standard technique described by The Fourth Report on The Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. BMI was adjusted for age and sex using the WHO 2007 growth reference. WHtR was ratio of waist circumference related to height in centimeters. Receiver operating characteristic (ROC curves were used to estimate the best cut-offs. Results: The best cut-off point for BMI-for-age Z-score (BMIZ to predict high BP was 0.51 with sensitivity and specificity of 82% (95% CI = 78-86 and 76% (95% CI = 67-78 for systolic BP and sensitivity and specificity of 82% (95% CI = 78-86 and 72% (95% CI = 68-76 for diastolic BP. The best cut-off point for WHtR was 0.45, with sensitivity of 76% (95% CI = 67-78 and specificity of 74% (95% CI = 71-79 for systolic BP and sensitivity of 76% (95% CI = 72-80 and specificity of 70% (95% CI = 61-75 for diastolic BP.Conclusion: BMIZ of 0.51 and WHtR of 0.45 are the best cut-off point to predict high BP in adolescents.

Cutting method for structural component into block like shape, and device used for cutting

International Nuclear Information System (INIS)

Nakazawa, Koichi; Ito, Akira; Tateiwa, Masaaki.

1995-01-01

Two grooves each of a predetermined depth are formed along a surface of a structural component, and a portion between the two grooves is cut in the direction of the depth from the surface of the structural component by using a cutting wire of a wire saw device. Then, the cutting wire is moved in the extending direction of the grooves while optionally changing the position in the direction of the depth to conduct cutting for the back face. Further, the cutting wire is moved in the direction of the depth of the groove toward the surface, to cut a portion between the two grooves. The wire saw device comprises a wire saw main body movable along the surface of the structural component, a pair of wire guide portions extending in the direction of the depth, guide pooleys capable of guiding the cutting wire guides revolvably and rotatably disposed at the top end, and an endless annular cutting wire extending between the wire guide portions. Thus, it is possible to continuously cut out blocks set to optional size and thickness. In addition, remote cutting is possible with no requirement for an operator to access to the vicinity of radioactivated portions. (N.H.)

An FMS Dynamic Production Scheduling Algorithm Considering Cutting Tool Failure and Cutting Tool Life

International Nuclear Information System (INIS)

Setiawan, A; Wangsaputra, R; Halim, A H; Martawirya, Y Y

2016-01-01

This paper deals with Flexible Manufacturing System (FMS) production rescheduling due to unavailability of cutting tools caused either of cutting tool failure or life time limit. The FMS consists of parallel identical machines integrated with an automatic material handling system and it runs fully automatically. Each machine has a same cutting tool configuration that consists of different geometrical cutting tool types on each tool magazine. The job usually takes two stages. Each stage has sequential operations allocated to machines considering the cutting tool life. In the real situation, the cutting tool can fail before the cutting tool life is reached. The objective in this paper is to develop a dynamic scheduling algorithm when a cutting tool is broken during unmanned and a rescheduling needed. The algorithm consists of four steps. The first step is generating initial schedule, the second step is determination the cutting tool failure time, the third step is determination of system status at cutting tool failure time and the fourth step is the rescheduling for unfinished jobs. The approaches to solve the problem are complete-reactive scheduling and robust-proactive scheduling. The new schedules result differences starting time and completion time of each operations from the initial schedule. (paper)

Advanced cutting techniques: laser and fissuration cutting

International Nuclear Information System (INIS)

Migliorati, B.; Gay, P.

1984-01-01

Experimental tests have been performed using CO 2 laser with output power 1 to 15 kW to evaluate the effect of varying the following parameters: material (carbon steel Fe 42 C, stainless steel AISI 304, concrete), laser power, beam characteristics, work piece velocity, gas type and distribution on the laser interaction zone. In the case of concrete, drilling depths of 80 mm were obtained in a few seconds using a 10 kW laser beam. Moreover pieces of 160 mm were cut at 0.01 meters per minute. Results with carbon steel indicated maximum thicknesses of 110 mm, cut at 0.01 meters per minute with 10 kW, depths about 20% lower were obtained with the AISI 304 stainless steel. A parallel investigation was aimed at characterizing particulate emission during the laser cutting process. At the end of the research it was possible to elaborate a preliminary proposal concerning a laser based dismantling system for the application to a typical Nuclear Power Station. (author)

Cutting agents for special metals

International Nuclear Information System (INIS)

Sugito, Seiji; Sakakibara, Fumi

1979-01-01

The quantity of use of special metals has increased year after year in the Plasma Research Institute, Nagoya University, with the development of researches on plasma and nuclear fusion. Most of these special metals are hard to cut, and in order to secure the surface smoothness and dimensional accuracy, considerable efforts are required. The method of experiment is as follows: cutting agents salt water and acetone, rape-seed oil, sulfide and chloride oil and water soluble cutting oil W grade 3; metals to be cut niobium, molybdenum, tantalum, titanium and tungsten; cutting conditions cutting speed 4.7 to 90 m/min, feed 0.07 to 0.2 mm/rev, depth of cut 0.1 to 0.4 mm, tool cemented carbide bit. Chemicals such as tetrachloromethane and trichloroethane give excellent cutting performance, but the toxicity is intense and the stimulative odor exists, accordingly they are hard to use practically. Cutting was easier when the salt water added with acetone was used than the case of rape-seed oil, but salt water is corrosive. Recently, the machining of molybdenum has been often carried out, and the water soluble cutting oil was the best. It is also good for cutting stainless steel, and its lubricating property is improved by adding some additives such as sulfur, chlorine, phosphorus and molybdenum disulfide. However after cutting with it, washing is required. (Kako, I.)

Study on processing parameters of glass cutting by nanosecond 532 nm fiber laser

Science.gov (United States)

Wang, Jin; Gao, Fan; Xiong, Baoxing; Zhang, Xiang; Yuan, Xiao

2018-03-01

The processing parameters of soda-lime glass cutting with several nanosecond 532 nm pulsed fiber laser are studied in order to obtain sufficiently large ablation rate and better processing quality. The influences of laser processing parameters on effective cutting speed and cutting quality of 1 2 mm thick soda-lime glass are studied. The experimental results show that larger laser pulse energy will lead to higher effective cutting speed and larger maximum edge collapse of the front side of the glass samples. Compared with that of 1.1 mm thick glass samples, the 2.0 mm thick glass samples is more difficult to cut. With the pulse energy of 51.2 μJ, the maximum edge collapse is more than 200 μm for the 2.0 mm thick glass samples. In order to achieve the high effective cutting speed and good cutting quality at the same time, the dual energy overlapping method is used to obtain the better cutting performance for the 2.0 mm thick glass samples, and the cutting speed of 194 mm/s and the maximum edge collapse of less than 132 μm are realized.

Segmentation of Synchrotron Radiation micro-Computed Tomography Images using Energy Minimization via Graph Cuts

Energy Technology Data Exchange (ETDEWEB)

Meneses, Anderson A.M. [Federal University of Western Para (Brazil); Physics Institute, Rio de Janeiro State University (Brazil); Giusti, Alessandro [IDSIA (Dalle Molle Institute for Artificial Intelligence), University of Lugano (Switzerland); Almeida, Andre P. de, E-mail: apalmeid@gmail.com [Physics Institute, Rio de Janeiro State University (Brazil); Nuclear Engineering Program, Federal University of Rio de Janeiro (Brazil); Nogueira, Liebert; Braz, Delson [Nuclear Engineering Program, Federal University of Rio de Janeiro (Brazil); Almeida, Carlos E. de [Radiological Sciences Laboratory, Rio de Janeiro State University (Brazil); Barroso, Regina C. [Physics Institute, Rio de Janeiro State University (Brazil)

2012-07-15

The research on applications of segmentation algorithms to Synchrotron Radiation X-Ray micro-Computed Tomography (SR-{mu}CT) is an open problem, due to the interesting and well-known characteristics of SR images, such as the phase contrast effect. The Energy Minimization via Graph Cuts (EMvGC) algorithm represents state-of-art segmentation algorithm, presenting an enormous potential of application in SR-{mu}CT imaging. We describe the application of the algorithm EMvGC with swap move for the segmentation of bone images acquired at the ELETTRA Laboratory (Trieste, Italy). - Highlights: Black-Right-Pointing-Pointer Microstructures of Wistar rats' ribs are investigated with Synchrotron Radiation {mu}CT imaging. Black-Right-Pointing-Pointer The present work is part of a research on the effects of radiotherapy on the thoracic region. Black-Right-Pointing-Pointer Application of the Energy Minimization via Graph Cuts algorithm for segmentation is described.

Performance Testing of Cutting Fluids

DEFF Research Database (Denmark)

Belluco, Walter

The importance of cutting fluid performance testing has increased with documentation requirements of new cutting fluid formulations based on more sustainable products, as well as cutting with minimum quantity of lubrication and dry cutting. Two sub-problems have to be solved: i) which machining...... tests feature repeatability, reproducibility and sensitivity to cutting fluids, and ii) to what extent results of one test ensure relevance to a wider set of machining situations. The present work is aimed at assessing the range of validity of the different testing methods, investigating correlation...... within the whole range of operations, materials, cutting fluids, operating conditions, etc. Cutting fluid performance was evaluated in turning, drilling, reaming and tapping, and with respect to tool life, cutting forces, chip formation and product quality (dimensional accuracy and surface integrity...

Laser beam cutting method. Laser ko ni yoru kaitai koho

Energy Technology Data Exchange (ETDEWEB)

Kutsumizu, A. (Obayashi Corp., Osaka (Japan))

1991-07-01

In this special issue paper concerning the demolition of concrete structures, was introduced a demolition of concrete structures using laser, of which practical application is expected due to the remarkable progress of generating power and efficiency of laser radiator. The characteristics of laser beam which can give a temperature of one million centigrade at the irradiated spot, the laser radiator consisting of laser medium, laser resonator and pumping apparatus, and the laser kinds for working, such as CO{sub 2} laser, YAG laser and CO laser, were described. The basic constitution of laser cutting equipment consisting of large generating power radiator, beam transmitter, beam condenser, and nozzle for working was also illustrated. Furthermore, strong and weak points in the laser cutting for concrete and reinforcement were enumerated. Applications of laser to cutting of reinforced and unreinforced concrete constructions were shown, and the concept and safety measure for application of laser to practical demolition was discussed. 5 refs., 8 figs.

Female genital cutting.

Science.gov (United States)

Perron, Liette; Senikas, Vyta; Burnett, Margaret; Davis, Victoria

2013-11-01

To strengthen the national framework for care of adolescents and women affected by female genital cutting (FGC) in Canada by providing health care professionals with: (1) information intended to strengthen their knowledge and understanding of the practice; (2) directions with regard to the legal issues related to the practice; (3) clinical guidelines for the management of obstetric and gynaecological care, including FGC related complications; and (4) guidance on the provision of culturally competent care to adolescents and women with FGC. Published literature was retrieved through searches of PubMed, CINAHL, and The Cochrane Library in September 2010 using appropriate controlled vocabulary (e.g., Circumcision, Female) and keywords (e.g., female genital mutilation, clitoridectomy, infibulation). We also searched Social Science Abstracts, Sociological Abstracts, Gender Studies Database, and ProQuest Dissertations and Theses in 2010 and 2011. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to December 2011. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Summary Statements 1. Female genital cutting is internationally recognized as a harmful practice and a violation of girls' and women's rights to life, physical integrity, and health. (II-3) 2. The immediate and long-term health risks and complications of female genital cutting can be serious and life threatening. (II-3) 3. Female genital cutting continues to be practised in many countries, particularly in sub-Saharan Africa, Egypt, and Sudan. (II-3) 4. Global migration

Numerical modelling of orthogonal cutting: application to woodworking with a bench plane.

Science.gov (United States)

Nairn, John A

2016-06-06

A numerical model for orthogonal cutting using the material point method was applied to woodcutting using a bench plane. The cutting process was modelled by accounting for surface energy associated with wood fracture toughness for crack growth parallel to the grain. By using damping to deal with dynamic crack propagation and modelling all contact between wood and the plane, simulations could initiate chip formation and proceed into steady-state chip propagation including chip curling. Once steady-state conditions were achieved, the cutting forces became constant and could be determined as a function of various simulation variables. The modelling details included a cutting tool, the tool's rake and grinding angles, a chip breaker, a base plate and a mouth opening between the base plate and the tool. The wood was modelled as an anisotropic elastic-plastic material. The simulations were verified by comparison to an analytical model and then used to conduct virtual experiments on wood planing. The virtual experiments showed interactions between depth of cut, chip breaker location and mouth opening. Additional simulations investigated the role of tool grinding angle, tool sharpness and friction.

Remotely controlled cutting techniques in the field of nuclear decommissioning. Overview of effectively applied thermal cutting methods

International Nuclear Information System (INIS)

Bienia, H.; Klotz, B.

2008-01-01

This article describes 3 thermal cutting technologies that are effectively used in nuclear decommissioning projects: the autonomous flame cutting, the plasma arc cutting and the contact arc metal cutting. The autonomous flame cutting technology is based on a high pressure oxygen jet oxidizing the material in a small kerf. Not all metal types are appropriate for this technology. The plasma arc cutting, in contrast to the previous technology, uses an electronically induced plasma arc to melt a kerf in the material. Inside the plasma arc temperatures up to 30.000 K exist, so in theory, this temperature is sufficient to cut all materials. Contact arc metal cutting is a new thermal cutting technology for under-water cutting works. Here, a carbon blade cuts the components. An electric arc between the cutting blade and component melts a kerf into the material easing the cutting. This technology allows the cutting of complex structures with hollows. The applications in nuclear facility dismantling of these 3 cutting technologies and their limits are reported and their requirements (staff, investment) listed in a table. (A.C.)

Extension without Cut

OpenAIRE

Straßburger , Lutz

2012-01-01

International audience; In proof theory one distinguishes sequent proofs with cut and cut-free sequent proofs, while for proof complexity one distinguishes Frege-systems and extended Frege-systems. In this paper we show how deep inference can provide a uniform treatment for both classifications, such that we can define cut-free systems with extension, which is neither possible with Frege-systems, nor with the sequent calculus. We show that the propositional pigeon-hole principle admits polyno...

Side Flow Effect on Surface Generation in Nano Cutting.

Science.gov (United States)

Xu, Feifei; Fang, Fengzhou; Zhang, Xiaodong

2017-12-01

The side flow of material in nano cutting is one of the most important factors that deteriorate the machined surface quality. The effects of the crystallographic orientation, feed, and the cutting tool geometry, including tool edge radius, rake angle and inclination angle, on the side flow are investigated employing molecular dynamics simulation. The results show that the stagnation region is formed in front of tool edge and it is characterized by the stagnation radius R s and stagnation height h s . The side flow is formed because the material at or under the stagnation region is extruded by the tool edge to flow to the side of the tool edge. Higher stagnation height would increase the size of the side flow. The anisotropic nature of the material which partly determines the stagnation region also influences the side flow due to the different deformation mechanism under the action of the tool edge. At different cutting directions, the size of the side flow has a great difference which would finally affect the machined surface quality. The cutting directions of {100} , {110} , and {110}  are beneficial to obtain a better surface quality with small side flow. Besides that, the side flow could be suppressed by reducing the feed and optimizing the cutting tool geometry. Cutting tool with small edge radius, large positive rake angle, and inclination angle would decrease the side flow and consequently improve the machined surface quality.

Computer-aided analysis of cutting processes for brittle materials

Science.gov (United States)

Ogorodnikov, A. I.; Tikhonov, I. N.

2017-12-01

This paper is focused on 3D computer simulation of cutting processes for brittle materials and silicon wafers. Computer-aided analysis of wafer scribing and dicing is carried out with the use of the ANSYS CAE (computer-aided engineering) software, and a parametric model of the processes is created by means of the internal ANSYS APDL programming language. Different types of tool tip geometry are analyzed to obtain internal stresses, such as a four-sided pyramid with an included angle of 120° and a tool inclination angle to the normal axis of 15°. The quality of the workpieces after cutting is studied by optical microscopy to verify the FE (finite-element) model. The disruption of the material structure during scribing occurs near the scratch and propagates into the wafer or over its surface at a short range. The deformation area along the scratch looks like a ragged band, but the stress width is rather low. The theory of cutting brittle semiconductor and optical materials is developed on the basis of the advanced theory of metal turning. The fall of stress intensity along the normal on the way from the tip point to the scribe line can be predicted using the developed theory and with the verified FE model. The crystal quality and dimensions of defects are determined by the mechanics of scratching, which depends on the shape of the diamond tip, the scratching direction, the velocity of the cutting tool and applied force loads. The disunity is a rate-sensitive process, and it depends on the cutting thickness. The application of numerical techniques, such as FE analysis, to cutting problems enhances understanding and promotes the further development of existing machining technologies.

Leaves Of Cut Rose Flower Convert Exogenously Applied Glucose To Sucrose And Translocate It To Petals

Directory of Open Access Journals (Sweden)

Horibe Takanori

2014-12-01

Full Text Available To understand the role that the leaves play in the translocation of soluble carbohydrates in cut rose flowers, we first evaluated the effect of leaf removal on flower quality and the sugar content in petals. Cut rose flowers with leaves had higher soluble sugar content in petals compared with cut flower without leaves. Next, we treated cut flowers with radioactive glucose to clarify translocation routes of exogenously applied sugar. There was no significant difference between the specific radioactivity of sucrose and glucose in leaves, but specific radioactivity of sucrose in petals was much higher than that of glucose. These results suggested that most of the exogenously applied glucose first moved to the leaves, where it was converted into sucrose and then the synthesised sucrose was translocated to the petals. Our results showed that the leaves of cut rose flowers play an important role in the metabolism and transportation of exogenously applied soluble carbohydrates toward the petals, thus contributing to sustaining the post-harvest quality.

Effect of microstructure and cutting speed on machining behavior of Ti6Al4V alloy

Energy Technology Data Exchange (ETDEWEB)

Telrandhe, Sagar V.; Mishra, Sushil; Saxena, Ashish K. [Indian Institute of Technology Bombay, Mumbai (India)

2017-05-15

Machining of aerospace and biomedical grade titanium alloys has always been a challenge because of their low conductivity and elastic modulus. Different machining methods and parameters have been adopted for high precision machining of titanium alloys. Machining of titanium alloys can be improved by microstructure optimization. The present study focuses on the effect of microstructure on ma- chinability of Ti6Al4V alloys at different cutting speeds. Samples were subjected to different annealing conditions resulting in different grain sizes and local micro-strains (misorientation). Cutting forces were significantly reduced after annealing; consequently, sub-surface residual stresses were reduced. Deformation twinning was also observed on samples annealed at a higher temperature due to larger grain size. Initial strain free grains and deformation twinning during machining reduces the cutting force at higher cutting speed.

Can partial‐cut harvesting be used to manage terrestrial lichen habitat? A review of recent evidence

Directory of Open Access Journals (Sweden)

Susan K. Stevenson

2015-12-01

Full Text Available Recent research suggests that partial-cut harvesting techniques can be used to alter successional trajectories in pine- and spruce-lichen woodlands, allowing forest managers to extend the period of reindeer lichen growth in mid- to late seral boreal forest stands. In Quebec, a fully replicated partial-cutting trial found that terrestrial lichen abundance remained at least as high in the partial cut as in the clearcuts or unlogged stands, and that the partial cut appeared to be on a trajectory to have even more terrestrial lichen due to sustained higher growth rates. In Alberta, a retrospective study found higher terrestrial lichen abundance in an early horse-logged partial cut than in undisturbed adjacent old forests or in clearcuts. Follow-up studies of partial-cut harvesting trials in British Columbia found that group selection plots 10 years after harvesting had lichen cover equivalent to that of undisturbed forest. In contrast, studies on lichen woodlands that have been defoliated by mountain pine beetle showed a major decline in reindeer lichen cover and a corresponding increase in vascular plant cover, similar to the results of previous studies on clear-cut logging impacts. Taken together these studies provide qualified support for the hypothesis that partial-cut harvesting can be used to enhance, or at least maintain, terrestrial lichen mats used as forage by caribou.

Physicochemical, microbial and sensory quality of fresh-cut red beetroots in relation to sanization method and storage duration

Directory of Open Access Journals (Sweden)

Dulal Chandra

2015-06-01

Full Text Available Effects of sanitization and storage on fresh-cut beetroots (Beta vulgaris L. were evaluated following sanitation – peeling - cutting (SPC, peeling – sanitation – cutting (PSC and peeling – cutting – sanitation (PCS methods with (Cl, or without (TW, 100 ppm chlorine solution, then packaged in polyethylene bag and stored at 5°C for up to 14 days. Chroma values of fresh-cut beetroots significantly declined whereas whiteness index and titratable acidity values increased, however, texture and total soluble solid contents showed no significant variation. Betalain contents decreased gradually and total phenol content showed inconsistence trend. PCS-Cl treated samples accounted for higher betalains decline and received lower visual quality scores despite its lower total aerobic bacterial count. Minimum microbial population was observed in PSC-Cl methodsalong with higher levels of betalain contents. Considering pigment retention, microbial and visual qualities, beetroots sanitized with chlorine water following PSC method was the best processingway for fresh-cut beetroots and therefore, PSC-Cl treatment could commercially be used for processing of fresh-cut beetroots.

Bovine Tuberculosis in Cattle in the Highlands of Cameroon: Seroprevalence Estimates and Rates of Tuberculin Skin Test Reactors at Modified Cut-Offs

Directory of Open Access Journals (Sweden)

J. Awah-Ndukum

2012-01-01

Full Text Available The aim of this study was to obtain epidemiological estimates of bovine tuberculosis (TB prevalence in cattle in the highlands of Cameroon using two population-based tuberculin skin test (TST surveys in the years 2009 and 2010. However, prior to the TST survey in 2010, blood was collected from already chosen cattle for serological assay. Anti-bovine TB antibodies was detected in 37.17% of tested animals and bovine TB prevalence estimates were 3.59%–7.48%, 8.92%–13.25%, 11.77%–17.26% and 13.14%–18.35% for comparative TST at ≥4 mm, ≥3 mm and ≥2 mm cut-off points and single TST, respectively. The agreement between TST and lateral flow was generally higher in TST positive than in TST negative subjects. The K coefficients were 0.119, 0.234, 0.251 and 0.254 for comparative TST at ≥4 mm, ≥3 mm and ≥2 mm cut-off points and the single TST groups, respectively. Chi square statistics revealed that strong (P48 associations existed between seroprevalence rates and TST reactors. The study suggested that using lateral flow assay and TST at severe interpretations could improve the perception of bovine TB in Cameroon. The importance of defining TST at modified cut-offs and disease status by post-mortem detection and mycobacterial culture of TB lesions in local environments cannot be overemphasised.

Cutting system for burnable poison rod

International Nuclear Information System (INIS)

Shiina, Atsushi; Toyama, Norihide; Koshino, Yasuo; Fujii, Toshio

1989-01-01

Burnable poison rods attached to spent fuels are contained in a containing box and transported to a receiving pool. The burnable poison rod-containing box is provisionally situated by the operation to a handling device to a provisional setting rack in a cutting pool and attached to a cutting guide of a cutting device upon cutting. The burnable poison rod is cut only in a cutting pool water and tritium generated upon cutting is dissolved into the cutting pool water. Diffusion of tritium is thus restricted. Further, the cutting pool is isolated by a partition device from the receiving pool during cutting of the burnable poison rod. Accordingly, water in which tritium is dissolved is inhibited from moving to the receiving pool and prevail of tritium contamination can be avoided. (T.M.)

Fast and intuitive programming of adaptive laser cutting of lace enabled by machine vision

Science.gov (United States)

Vaamonde, Iago; Souto-López, Álvaro; García-Díaz, Antón

2015-07-01

A machine vision system has been developed, validated, and integrated in a commercial laser robot cell. It permits an offline graphical programming of laser cutting of lace. The user interface allows loading CAD designs and aligning them with images of lace pieces. Different thread widths are discriminated to generate proper cutting program templates. During online operation, the system aligns CAD models of pieces and lace images, pre-checks quality of lace cuts and adapts laser parameters to thread widths. For pieces detected with the required quality, the program template is adjusted by transforming the coordinates of every trajectory point. A low-cost lace feeding system was also developed for demonstration of full process automation.

Grand unified theory precursors and nontrivial fixed points in higher-dimensional gauge theories

International Nuclear Information System (INIS)

Dienes, Keith R.; Dudas, Emilian; Gherghetta, Tony

2003-01-01

Within the context of traditional logarithmic grand unification at M GUT ≅10 16 GeV, we show that it is nevertheless possible to observe certain GUT states such as X and Y gauge bosons at lower scales, perhaps even in the TeV range. We refer to such states as 'GUT precursors'. These states offer an interesting alternative possibility for new physics at the TeV scale, and could be used to directly probe GUT physics even though the scale of gauge coupling unification remains high. Our results also give rise to a Kaluza-Klein realization of nontrivial fixed points in higher-dimensional gauge theories

Heat damage-free laser-microjet cutting achieves highest die fracture strength

Science.gov (United States)

Perrottet, Delphine; Housh, Roy; Richerzhagen, Bernold; Manley, John

2005-04-01

Unlike conventional laser-based technologies, the water jet guided laser does not generate heat damage and contamination is also very low. The negligible heat-affected zone is one reason why die fracture strength is higher than with sawing. This paper first presents the water jet guided laser technology and then explains how it differs from conventional dry laser cutting. Finally, it presents the results obtained by three recent studies conducted to determine die fracture strength after Laser-Microjet cutting.

Effects of electron beam irradiation on cut flowers and mites

International Nuclear Information System (INIS)

Dohino, Toshiyuki; Tanabe, Kazuo

1994-01-01

Two spotted spider mite, Tetranychus urticae KOCH were irradiated with electron beams (2.5MeV) to develop an alternative quarantine treatment for imported cut flowers. The tolerance of eggs increased with age (1-5-day-old). Immature stages (larva-teleiochrysalis) irradiated at 0.4-0.8kGy increased tolerance with their development. Mated mature females irradiated at 0.4kGy or higher did not produce viable eggs, although temporary recovery was observed at 0.2kGy. Adult males were sterilized at 0.4kGy because non-irradiated virgin females mated with yielded female progeny malformed and sterilized. Various effects of electron beam irradiation were observed when nine species of cut flowers were irradiated in 5MeV Dynamitron accelerator. Chrysanthemum and rose were most sensitive among cut flowers. (author)

Ductile cutting of silicon microstructures with surface inclination measurement and compensation by using a force sensor integrated single point diamond tool

International Nuclear Information System (INIS)

Chen, Yuan-Liu; Cai, Yindi; Shimizu, Yuki; Ito, So; Gao, Wei; Ju, Bing-Feng

2016-01-01

This paper presents a measurement and compensation method of surface inclination for ductile cutting of silicon microstructures by using a diamond tool with a force sensor based on a four-axis ultra-precision lathe. The X- and Y-directional inclinations of a single crystal silicon workpiece with respect to the X- and Y-motion axes of the lathe slides were measured respectively by employing the diamond tool as a touch-trigger probe, in which the tool-workpiece contact is sensitively detected by monitoring the force sensor output. Based on the measurement results, fabrication of silicon microstructures can be thus carried out directly along the tilted silicon workpiece by compensating the cutting motion axis to be parallel to the silicon surface without time-consuming pre-adjustment of the surface inclination or turning of a flat surface. A diamond tool with a negative rake angle was used in the experiment for superior ductile cutting performance. The measurement precision by using the diamond tool as a touch-trigger probe was investigated. Experiments of surface inclination measurement and ultra-precision ductile cutting of a micro-pillar array and a micro-pyramid array with inclination compensation were carried out respectively to demonstrate the feasibility of the proposed method. (paper)

Theoretical Models for Orthogonal Cutting

DEFF Research Database (Denmark)

De Chiffre, Leonardo

This review of simple models for orthogonal cutting was extracted from: “L. De Chiffre: Metal Cutting Mechanics and Applications, D.Sc. Thesis, Technical University of Denmark, 1990.”......This review of simple models for orthogonal cutting was extracted from: “L. De Chiffre: Metal Cutting Mechanics and Applications, D.Sc. Thesis, Technical University of Denmark, 1990.”...

IN VITRO FLOW ANALYSIS OF NOVEL DOUBLE-CUTTING, OPEN-PORT, ULTRAHIGH-SPEED VITRECTOMY SYSTEMS.

Science.gov (United States)

Zehetner, Claus; Moelgg, Marion; Bechrakis, Emmanouil; Linhart, Caroline; Bechrakis, Nikolaos E

2017-10-09

To analyze the performance and flow characteristics of novel double-cutting, open-port, 23-, 25-, and 27-gauge ultrahigh-speed vitrectomy systems. In vitro fluidic measurements were performed to assess the volumetric aspiration profiles of several vitrectomy systems in basic salt solution and egg white. Double-cutting open-port vitrectomy probes delivered stable aspiration flow rates that were less prone to flow variation affected by the cutting speed. Increase in cutting frequency to the maximum level resulted in flow reduction of less than 10% (0.0%-9.5%). Commercially available 23-, 25-, and 27-G double-cutting probes exhibited higher egg-white and basic salt solution flow rates at all evaluated cut rates, with aspirational efficiencies being 1.1 to 2.9 times the flow rates of standard single-blade vitrectomy probes of the same caliber at the maximum preset vacuum. The highest relative differences were observed at faster cut rates. The newly introduced double-cutting open-port vitrectomy probes delivered stable aspiration flow rates that were less prone to flow variation affected by the cutting speed. The fluidic principle of constant flow even at the highest cut rates and low vacuum levels might impact surgical strategies, especially when performing manipulations close to the retina.

Cutting characteristics and deformed layer of type 316LN stainless steel

International Nuclear Information System (INIS)

Oh, Sun Sae; Yi, Won

2004-01-01

The cutting characteristics and the deformed layer of Nitrogen(N)-added type 316LN stainless steel were comparatively investigated to type 316L stainless steel. The cutting force, the surface roughness(Ra) and the tool wear in face milling works were measured with cutting conditions, and the deformed layers were obtained from micro-hardness testing method. The cutting resistance of type 316LN was similar to type 316L in spite of its high strength. The surface roughness of type 316LN was superior to type 316L for all the cutting conditions. In particular, in the high cutting speed above 345m/min, the surface roughness of the two stainless steels was closely same. The deformed layer thickness of the two stainless steels was generated in the 150μm-300μm ranges, and its value of type 316LN was lower than that of type 316L. This is due to the high strength properties by nitrogen effect. It was found that type 316LN was higher in the tool wear than that type 316L, and flank wear was dominant to crater wear. In face milling works of type 316LN steel, tool wear is regarded as a important problem

A study of estimating cutting depth for multi-pass nanoscale cutting by using atomic force microscopy

International Nuclear Information System (INIS)

Lin, Zone-Ching; Hsu, Ying-Chih

2012-01-01

This paper studies two models for estimating cutting depth of multi-pass nanoscale cutting by using an atomic force microscopy (AFM) probe. One estimates cutting depth for multi-pass nanoscale cutting by using regression equations of nanoscale contact pressure factor (NCP factor) while the other uses equation of specific down force energy (SDFE). This paper proposes taking a diamond-coated probe of AFM as the cutting tool to carry out multi-pass nanoscale cutting experiments on the surface of sapphire substrate. In the process of experimentation, different down forces are set, and the probe shape of AFM is known, then using each down force to multi-pass cutting the sapphire substrate. From the measured experimental data of a central cutting depth of the machining groove by AFM, this paper calculates the specific down force energy of each down force. The experiment results reveal that the specific down force energy of each case of multi-pass nanoscale cutting for different down forces under a probe of AFM is close to a constant value. This paper also compares the nanoscale cutting results from estimating cutting depths for each pass of multi-pass among the experimental results and the calculating results obtained by the two theories models. It is found that the model of specific down force energy can calculate cutting depths for each nanoscale cutting pass by one equation. It is easier to use than the multi-regression equations of the nanoscale contact pressure factor. Besides, the estimations of cutting depth results obtained by the model of specific down force energy are closer to that of the experiment results. It shows that the proposed specific down force energy model in this paper is an acceptable model.

Kolmogorov and Zabih’s Graph Cuts Stereo Matching Algorithm

Directory of Open Access Journals (Sweden)

Vladimir Kolmogorov

2014-10-01

Full Text Available Binocular stereovision estimates the three-dimensional shape of a scene from two photographs taken from different points of view. In rectified epipolar geometry, this is equivalent to a matching problem. This article describes a method proposed by Kolmogorov and Zabih in 2001, which puts forward an energy-based formulation. The aim is to minimize a four-term-energy. This energy is not convex and cannot be minimized except among a class of perturbations called expansion moves, in which case an exact minimization can be done with graph cuts techniques. One noteworthy feature of this method is that it handles occlusion: The algorithm detects points that cannot be matched with any point in the other image. In this method displacements are pixel accurate (no subpixel refinement.

Performance evaluation of extractor cutting blade configuration in Inulin extraction process from Dahlia sp. L tuber

Science.gov (United States)

Sundari, E.; Praputri, E.; Marthiana, W.; Jaya, M.

2018-03-01

Inulin, a polysaccharide plant-based nutrient, can be isolated from dahlia flower tubers by liquid-solid extraction processes and is generally carried out in an extractor tank equipped with an agitator. To accelerate the diffusion rate of solute from the solid phase (bulk phase) to the external surface (boundary layer) in order to increase yield of inulin, the size reduction of material is required. The purpose of this research was to design the cutting blade needed for dahlia tuber size reduction and investigate the effect of blade types, agitator speed (350, 700, 1050, and 1400 rpm), and configuration of cutting blade to material fineness at 90 minutes of contacting time. The results showed that higher cutting blade speed results in higher cut material fineness rate. The best conditions was achieved by the configuration of two four-blade turbine combined with one three-blade turbine with fineness rate more than 90% in 30 minutes of contacting time at every variation of agitator speed. The cutting blade designed in this study can be used for size reduction purpose of tubers other than dahlia tubers.

A thermo-electro-mechanical simulation model for hot wire cutting of EPS foam

DEFF Research Database (Denmark)

Petkov, Kiril; Hattel, Jesper Henri

2016-01-01

A one-dimensional thermo-electro-mechanical mathematical model describing the effects taking place within a Ni-Cr20% wire used in a hot-wire cutting process for free forming and rapid prototyping of expanded polystyrene (EPS) is investigated and simulated. The model implements and solves three semi...... cutting of EPS in contact with a cutting tool made of an electrically heated metal wire attached to a robot device. The finite difference method is used to solve the coupled equations in the two environments (domains) in which the hot-wire operates, namely air and EPS. The model is calibrated against...... experimentally obtained data. Novel findings are a transient temperature-dependent kerfwidth prediction and a relation between kerfwidth and the cutting angle as measured from the horizontal direction. These are important relations in the aim for higher geometrical accuracy of the hot-wire cutting process. (C...

Flux cutting in superconductors

International Nuclear Information System (INIS)

Campbell, A M

2011-01-01

This paper describes experiments and theories of flux cutting in superconductors. The use of the flux line picture in free space is discussed. In superconductors cutting can either be by means of flux at an angle to other layers of flux, as in longitudinal current experiments, or due to shearing of the vortex lattice as in grain boundaries in YBCO. Experiments on longitudinal currents can be interpreted in terms of flux rings penetrating axial lines. More physical models of flux cutting are discussed but all predict much larger flux cutting forces than are observed. Also, cutting is occurring at angles between vortices of about one millidegree which is hard to explain. The double critical state model and its developments are discussed in relation to experiments on crossed and rotating fields. A new experiment suggested by Clem gives more direct information. It shows that an elliptical yield surface of the critical state works well, but none of the theoretical proposals for determining the direction of E are universally applicable. It appears that, as soon as any flux flow takes place, cutting also occurs. The conclusion is that new theories are required. (perspective)

Statistical characteristics of surface integrity by fiber laser cutting of Nitinol vascular stents

International Nuclear Information System (INIS)

Fu, C.H.; Liu, J.F.; Guo, Andrew

2015-01-01

Graphical abstract: - Highlights: • Precision kerf with tight tolerance of Nitinol stents can be cut by fiber laser. • No HAZ in the subsurface was detected due to large grain size. • Recast layer has lower hardness than the bulk. • Laser cutting speed has a higher influence on surface integrity than laser power. - Abstract: Nitinol alloys have been widely used in manufacturing of vascular stents due to the outstanding properties such as superelasticity, shape memory, and superior biocompatibility. Laser cutting is the dominant process for manufacturing Nitinol stents. Conventional laser cutting usually produces unsatisfactory surface integrity which has a significant detrimental impact on stent performance. Emerging as a competitive process, fiber laser with high beam quality is expected to produce much less thermal damage such as striation, dross, heat affected zone (HAZ), and recast layer. To understand the process capability of fiber laser cutting of Nitinol alloy, a design-of-experiment based laser cutting experiment was performed. The kerf geometry, roughness, topography, microstructure, and hardness were studied to better understand the nature of the HAZ and recast layer in fiber laser cutting. Moreover, effect size analysis was conducted to investigate the relationship between surface integrity and process parameters.

Statistical characteristics of surface integrity by fiber laser cutting of Nitinol vascular stents

Energy Technology Data Exchange (ETDEWEB)

Fu, C.H., E-mail: cfu5@crimson.ua.edu [Dept of Mechanical Engineering, The University of Alabama, Tuscaloosa, AL 35487 (United States); Liu, J.F. [Dept of Mechanical Engineering, The University of Alabama, Tuscaloosa, AL 35487 (United States); Guo, Andrew [Dept of Mechanical Engineering, The University of Alabama, Tuscaloosa, AL 35487 (United States); College of Arts and Science, Vanderbilt University, Nashville, TN 37235 (United States)

2015-10-30

Graphical abstract: - Highlights: • Precision kerf with tight tolerance of Nitinol stents can be cut by fiber laser. • No HAZ in the subsurface was detected due to large grain size. • Recast layer has lower hardness than the bulk. • Laser cutting speed has a higher influence on surface integrity than laser power. - Abstract: Nitinol alloys have been widely used in manufacturing of vascular stents due to the outstanding properties such as superelasticity, shape memory, and superior biocompatibility. Laser cutting is the dominant process for manufacturing Nitinol stents. Conventional laser cutting usually produces unsatisfactory surface integrity which has a significant detrimental impact on stent performance. Emerging as a competitive process, fiber laser with high beam quality is expected to produce much less thermal damage such as striation, dross, heat affected zone (HAZ), and recast layer. To understand the process capability of fiber laser cutting of Nitinol alloy, a design-of-experiment based laser cutting experiment was performed. The kerf geometry, roughness, topography, microstructure, and hardness were studied to better understand the nature of the HAZ and recast layer in fiber laser cutting. Moreover, effect size analysis was conducted to investigate the relationship between surface integrity and process parameters.

Cut-off values of distal forearm bone density for the diagnosis of ...

African Journals Online (AJOL)

Background: The objective of this study was to establish a triage cut-off point or threshold for peripheral bone mineral density (BMD), applicable to black postmenopausal women, and that could be used as a screening method to differentiate between women with normal BMD, and those with possible central osteoporosis.

Metal cutting by radiation from a CO2 laser with a self-filtering cavity

International Nuclear Information System (INIS)

Malikov, A G; Orishich, Anatolii M; Shulyat'ev, Viktor B

2009-01-01

The possibility of quality cutting by radiation from a CO 2 laser with an unstable self-filtering cavity (SFC) is experimentally investigated. The SFC provides the product of the divergence angle by the beam radius close to that for lower modes in a stable cavity (SC), however, at a higher radiation power, which favours faster cutting. In the far-field zone, the SFC beam has a diffraction structure with side maxima, which is usually considered as a negative factor in laser cutting. 25-mm-thick steel slabs have been cut. The comparison of the obtained results with known data on SC lasers shows that the principal characteristics of the cut (the width, edge roughness, specific expenditure of energy) are close in these lasers. A conclusion is made that at the chosen cavity parameters, the specific spatial structure of the SFC laser beam has no significant effect on the cut characteristics. (laser technologies)

Cutting temperature measurement and material machinability

Directory of Open Access Journals (Sweden)

Nedić Bogdan P.

2014-01-01

Full Text Available Cutting temperature is very important parameter of cutting process. Around 90% of heat generated during cutting process is then away by sawdust, and the rest is transferred to the tool and workpiece. In this research cutting temperature was measured with artificial thermocouples and question of investigation of metal machinability from aspect of cutting temperature was analyzed. For investigation of material machinability during turning artificial thermocouple was placed just below the cutting top of insert, and for drilling thermocouples were placed through screw holes on the face surface. In this way was obtained simple, reliable, economic and accurate method for investigation of cutting machinability.

Stresses in ultrasonically assisted bone cutting

International Nuclear Information System (INIS)

Alam, K; Mitrofanov, A V; Silberschmidt, V V; Baeker, M

2009-01-01

Bone cutting is a frequently used procedure in the orthopaedic surgery. Modern cutting techniques, such as ultrasonic assisted drilling, enable surgeons to perform precision operations in facial and spinal surgeries. Advanced understanding of the mechanics of bone cutting assisted by ultrasonic vibration is required to minimise bone fractures and to optimise the technique performance. The paper presents results of finite element simulations on ultrasonic and conventional bone cutting analysing the effects of ultrasonic vibration on cutting forces and stress distribution. The developed model is used to study the effects of cutting and vibration parameters (e.g. amplitude and frequency) on the stress distributions in the cutting region.

Optimisation Of Cutting Parameters Of Composite Material Laser Cutting Process By Taguchi Method

Science.gov (United States)

Lokesh, S.; Niresh, J.; Neelakrishnan, S.; Rahul, S. P. Deepak

2018-03-01

The aim of this work is to develop a laser cutting process model that can predict the relationship between the process input parameters and resultant surface roughness, kerf width characteristics. The research conduct is based on the Design of Experiment (DOE) analysis. Response Surface Methodology (RSM) is used in this work. It is one of the most practical and most effective techniques to develop a process model. Even though RSM has been used for the optimization of the laser process, this research investigates laser cutting of materials like Composite wood (veneer)to be best circumstances of laser cutting using RSM process. The input parameters evaluated are focal length, power supply and cutting speed, the output responses being kerf width, surface roughness, temperature. To efficiently optimize and customize the kerf width and surface roughness characteristics, a machine laser cutting process model using Taguchi L9 orthogonal methodology was proposed.

Selection of Near Optimal Laser Cutting Parameters in CO2 Laser Cutting by the Taguchi Method

Directory of Open Access Journals (Sweden)

Miloš MADIĆ

2013-12-01

Full Text Available Identification of laser cutting conditions that are insensitive to parameter variations and noise is of great importance. This paper demonstrates the application of Taguchi method for optimization of surface roughness in CO2 laser cutting of stainless steel. The laser cutting experiment was planned and conducted according to the Taguchi’s experimental design using the L27 orthogonal array. Four laser cutting parameters such as laser power, cutting speed, assist gas pressure, and focus position were considered in the experiment. Using the analysis of means and analysis of variance, the significant laser cutting parameters were identified, and subsequently the optimal combination of laser cutting parameter levels was determined. The results showed that the cutting speed is the most significant parameter affecting the surface roughness whereas the influence of the assist gas pressure can be neglected. It was observed, however, that interaction effects have predominant influence over the main effects on the surface roughness.

How Can I Stop Cutting?

Science.gov (United States)

... Educators Search English Español How Can I Stop Cutting? KidsHealth / For Teens / How Can I Stop Cutting? ... in a soft, cozy blanket Substitutes for the Cutting Sensation You'll notice that all the tips ...

Rooting of stem cuttings of ixora

Directory of Open Access Journals (Sweden)

Aline De Souza Silva

2015-08-01

Full Text Available The ixora is ornamental plant widely used in landscaping. In order to maximize the propagation of cuts, we evaluated the concentrations of auxin (indolbutiric acid and the presence of leaves on the rooting in cuts of Ixora coccinea L. The experiment was conducted in randomized block design, in factorial design 3x4, with three types of cuts (without leaf, with two or four leaves, four concentrations of indolbutiric acid (0, 1000, 2000 and 4000 mg L-1, with four replications and 10 cuts in each experimental unit. After 53 days of implantation the experiment, evaluated the survival(%, rooting(%, sprouting(%, formation of callus(%, number, length and biomass of roots formed. The interaction of the type of cuts with concentrations of auxin was not significant for any of the variables analyzed. The survival of cuttings was not influenced by the treatments. Cuts with two or four leaves presented rooting and length of roots above the cuttings without leaves. The application of auxin does not substitute the presence of leaf in cuts of ixora in vegetative propagation. The vegetative propagation by cut of ixora can be made without application of auxin, and the leaves must be maintained in the cuttings.

Critical element development of standard components for pipe welding/cutting by CO{sub 2} laser

Energy Technology Data Exchange (ETDEWEB)

Oka, Kiyoshi; Kakudate, Satoshi; Nakahira, Masataka [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

1994-11-01

In D-T burning reactors such as International Thermonuclear Experimental Reactor(ITER), an internal access is inevitable for welding/cutting of cooling pipes of in-vessel components, because of spatial constraint due to a narrow port opening space. An internal-access pipe welding/cutting equipment is being developed in JAERI. Internal access is to approach through inside a pipe to a welding/cutting position, to use 10kW CO{sub 2} laser beam, and to be applicable to both welding and cutting with using a same processing head. A welding/cutting processing head with 10kW CO{sub 2} laser beam has been fabricated and the basic feasibility has been successfully demonstrated for studies of the internal-access pipe welding/cutting concept using 100-A stainless steel pipe with a thickness of 6.3mm. In this study, the optimum focal point of laser beam, laser power and traveling speed of the head have been investigated together with an adjusting mechanism of a relative distance between the head and the pipe wall. In addition, the radiation resistance of critical elements such as optical lens has been investigated. (author).

Cutting efficiency of diamond burs operated with electric high-speed dental handpiece on zirconia.

Science.gov (United States)

Nakamura, Keisuke; Katsuda, Yusuke; Ankyu, Shuhei; Harada, Akio; Tenkumo, Taichi; Kanno, Taro; Niwano, Yoshimi; Egusa, Hiroshi; Milleding, Percy; Örtengren, Ulf

2015-10-01

Zirconia-based dental restorations are becoming used more commonly. However, limited attention has been given to the difficulties experienced, concerning cutting, in removing the restorations when needed. The aim of the present study was to compare the cutting efficiency of diamond burs, operated using an electric high-speed dental handpiece, on zirconia (Zir) with those on lithium disilicate glass-ceramic (LD) and leucite glass-ceramic (L). In addition, evaluation of the cutting efficiency of diamond burs on Zir of different thicknesses was performed. Specimens of Zir were prepared with thicknesses of 0.5, 1.0, 2.0, and 4.0 mm, and specimens of LD and L were prepared with a thickness of 1.0 mm. Cutting tests were performed using diamond burs with super coarse (SC) and coarse (C) grains. The handpiece was operated at 150,000 rpm with a cutting force of 0.9 N. The results demonstrated that cutting of Zir took about 1.5- and 7-fold longer than cutting of LD and L, respectively. The SC grains showed significantly higher cutting efficiency on Zir than the C grains. However, when the thickness of Zir increased, the cutting depth was significantly decreased. As it is suggested that cutting of zirconia is time consuming, this should be taken into consideration in advance when working with zirconia restorations. © 2015 Eur J Oral Sci.

CALCULATION OF LASER CUTTING COSTS

OpenAIRE

Bogdan Nedic; Milan Eric; Marijana Aleksijevic

2016-01-01

The paper presents description methods of metal cutting and calculation of treatment costs based on model that is developed on Faculty of mechanical engineering in Kragujevac. Based on systematization and analysis of large number of calculation models of cutting with unconventional methods, mathematical model is derived, which is used for creating a software for calculation costs of metal cutting. Software solution enables resolving the problem of calculating the cost of laser cutting, compar...

Method of cutting radioactivated metal structures

International Nuclear Information System (INIS)

Takimoto, Yoshinori; Sakota, Kotaro; Hamamoto, Noboru; Harada, Keizo.

1985-01-01

Purpose: To improve the cutting performance to a level as comparable with that in air, as well as prevent the scattering of the radioactive materials upon cutting to the level as that in water cutting. Method: After igniting a gas cutting torch automatically, water spray by the local water sprayer is started by the actuation of a submerged pump, while a gas cutting manipulator is operated to cut the nuclear reactor pressure vessel. In this way, cutting exhaust gases resulted from the gas cutting torch are water-washed by the spray from the local water sprayer and falls within the nuclear rector pressure vessel in the form of water streams or droplets along the inner wall surface of the pressure vessel. Further, water is fed again to the local water sprayer by the submerged pump. (Kawakami, Y.)

Laser Cutting of Thin Nickel Bellows

Science.gov (United States)

Butler, C. L.

1986-01-01

Laser cutting technique produces narrow, precise, fast, and repeatable cuts in thin nickel-allow bellows material. Laser cutting operation uses intense focused beam to melt material and assisting gas to force melted material through part thickness, creating void. When part rotated or moved longitudinally, melting and material removal continuous and creates narrow, fast, precise, and repeatable cut. Technique used to produce cuts of specified depths less than material thickness. Avoids distortion, dents, and nicks produced in delicate materials during lathe trimming operations, which require high cutting-tool pressure and holding-fixture forces.

Towards a safety case for the use of laser cutting in nuclear decommissioning

International Nuclear Information System (INIS)

Hilton, P.A.

2014-01-01

Some of the requirements in nuclear decommissioning include size reduction of contaminated containers, pipework and other structures manufactured from stainless and other steels. Size reduction is generally performed using mechanical saws or shears, with drawbacks of quick wear, significant applied force, difficult remote operation and addition to contaminated waste mass. The use of lasers for cutting within the context of nuclear decommissioning has been recently demonstrated by TWI and others. In this paper, aspects of drawing together a safety case for using laser beams for cutting in a nuclear decommissioning cell are discussed, via analysis of relevant purpose designed experimental data. Data presented includes assessment of the use of different focal length lenses and the power densities anticipated at distances of up to 3 m from the focal point, as well as beam effects on material behind the cutting zone. An assessment of anticipated material damage from stray beams or unintended exposure to laser light of surrounding items is also presented. Finally materials for effective screening against stray beams during the cutting process have been tested for effectiveness. (authors)

Experimental improvement of the technology of cutting of high-pressure hoses with metal braid on hand cutting machine

OpenAIRE

Karpenko, Mykola; Bogdevicius, Marijonas; Prentkovskis, Olegas

2016-01-01

In the article the review of the problem of improvement of technology of high pressure hoses cutting on the hand cutting machines is analyzed. Different methods of cutting of high pressure hoses into the billets are overviewed and the quality of edge cuts of hoses is analyzed. The comparison of treatment on automatic cutting machines and on hand cutting machines is carried out. Different experimental techniques of improvement of the quality of edges cutting of high pressure hoses are prese...

Performance Testing of Thermal Cutting Systems for Sweet Pepper Harvesting Robot in Greenhouse Horticulture

Science.gov (United States)

Bachche, Shivaji; Oka, Koichi

2013-03-01

This paper proposes design of end-effector and prototype of thermal cutting system for harvesting sweet peppers. The design consists of two parallel gripper bars mounted on a frame connected by specially designed notch plate and operated by servo motor. Based on voltage and current, two different types of thermal cutting system prototypes; electric arc and temperature arc respectively were developed and tested for performance. In electric arc, a special electric device was developed to obtain high voltage to perform cutting operation. At higher voltage, electrodes generate thermal arc which helps to cut stem of sweet pepper. In temperature arc, nichrome wire was mounted between two electrodes and current was provided directly to electrodes which results in generation of high temperature arc between two electrodes that help to perform cutting operation. In both prototypes, diameters of basic elements were varied and the effect of this variation on cutting operation was investigated. The temperature arc thermal system was found significantly suitable for cutting operation than electric arc thermal system. In temperature arc thermal cutting system, 0.5 mm nichrome wire shows significant results by accomplishing harvesting operation in 1.5 seconds. Also, thermal cutting system found suitable to increase shelf life of fruits by avoiding virus and fungal transformation during cutting process and sealing the fruit stem. The harvested sweet peppers by thermal cutting system can be preserved at normal room temperature for more than 15 days without any contamination.

Extracting Corresponding Point Based on Texture Synthesis for Nearly Flat Textureless Object Surface

Directory of Open Access Journals (Sweden)

Min Mao

2015-01-01

Full Text Available Since the image feature points are always gathered at the range with significant intensity change, such as textured portions or edges of an image, which can be detected by the state-of-the-art intensity based point-detectors, there is nearly no point in the areas of low textured detected by classical interest-point detectors. In this paper we describe a novel algorithm based on affine transform and graph cut for interest point detecting and matching from wide baseline image pairs with weakly textured object. The detection and matching mechanism can be separated into three steps: firstly, the information on the large textureless areas will be enhanced by adding textures through the proposed texture synthesis algorithm TSIQ. Secondly, the initial interest-point set is detected by classical interest-point detectors. Finally, graph cuts are used to find the globally optimal set of matching points on stereo pairs. The efficacy of the proposed algorithm is verified by three kinds of experiments, that is, the influence of point detecting from synthetic texture with different texture sample, the stability under the different geometric transformations, and the performance to improve the quasi-dense matching algorithm, respectively.

Early lactate clearance in septic patients with elevated lactate levels admitted from the emergency department to intensive care: time to aim higher?

Science.gov (United States)

Walker, Craig A; Griffith, David M; Gray, Alasdair J; Datta, Deepankar; Hay, Alasdair W

2013-10-01

Septic patients with hyperlactatemia have increased mortality rates, irrespective of hemodynamic and oxygen-derived variables. The aims of the study are the following: (1) to ascertain whether lactate clearance (LC) (percentage change in lactate over unit time) predicts mortality in septic patients admitted to intensive care directly from the emergency department and (2) to calculate the optimal "cut-off" value for mortality prediction. Three-year retrospective observational study of consecutive patients with severe sepsis and septic shock admitted to intensive care from the emergency department of a tertiary UK hospital. We calculated 6-hour LC, performed receiver operating characteristic analyses to calculate optimal cut-off values for initial lactate and LC, dichotomized patients according to the LC cut-off, and calculated hazard ratios using a Cox proportional hazards model. One hundred six patients were identified; 78, after exclusions. Lactate clearance was independently associated with 30-day mortality (P<.04); optimal cut-off, 36%. Mortality rates were 61.1% and 10.7% for patients with 6-hour LC 36% or less and greater than 36%, respectively. Hazard ratio for death with LC 36% or less was 7.33 (95% confidence interval, 2.17-24.73; P<.001). Six-hour LC was independently associated with mortality, and the optimal cut-off value was 36%, significantly higher than previously reported. We would support further research investigating this higher LC as a distinct resuscitation end point in patients with severe sepsis and septic shock. Copyright © 2013 Elsevier Inc. All rights reserved.

Characterization of aerosols produced in cutting steel components and concrete structures by means of a laser beam

International Nuclear Information System (INIS)

Tarroni, G.; Melandri, C.; Zaiacomo, T. de; Lombard, C.C.; Formignani, M.

1986-01-01

The technique of cutting based on the use of a laser beam is studied as a possible method in nuclear plant dismantling (OECD, 1982). The technique implies a relevant problem of contamination due to high aerosol production. Tests have been carried out to characterize the aerosol produced in cutting steel and concrete in terms of size spectrum, electric charge and chemical composition in comparison with bulk material composition. The high temperature value locally reached in the cutting zone causes material vaporization with emission of very fine primary particles. In such conditions aerosol coagulation is very fast (it occurs in less than 1s) and leads to aggregates. Research has been aimed at finding the characteristics of the aerosol removable from the cutting zone by ventilation and evaluating the morphology of the particles that diffuse at approximately 50 cm from the generation point, or settle on the cutting-box base. (author)

Cut-Off Value for Pain Sensitivity Questionnaire in Predicting Surgical Success in Patients with Lumbar Disc Herniation.

Directory of Open Access Journals (Sweden)

Parisa Azimi

Full Text Available Various factors related to predict surgical success were studied; however, a standard cut-off point for the Pain Sensitivity Questionnaire (PSQ measure has not yet been established for a favorable surgical outcome for lumbar disc herniation (LDH. This study was to find the optimal cut-off point on the PSQ to distinguish surgical success in patients with LDH. A total of 154 patients with LDH consecutively referred to our clinic were enrolled into this prospective study between February 2011 and January 2014. All participants completed the PSQ. Patients completed the Oswestry Disability Index (ODI score before surgery, and at 2 years after surgery. Surgical success was defined as a 13-point improvement from the baseline ODI scores. The cut-off value for PSQ was determined by the receiver-operating characteristic curve (ROC. The mean age of patients was 49.3±9.6 years, and there were 80 women. The mean time for follow-up assessment was 31±5 months (range 24-35. Post-surgical success was 79.9% (n = 123 at 2 years follow up. The mean score for the total PSQ, PSQ-minor, and PSQ-moderate were 6.0 (SD = 1.6, 5.4 (SD = 1.9 and 6.5 (SD = 1.7, respectively. Total PSQ score was also significantly correlated with the total scores of the ODI. The optimal total PSQ cut-off point was determined as > 5.2 to predict surgical success in LDH patients, with 80.0% sensitivity and 75.6% specificity (AUC-0.814, 95% CI 0.703-0.926. This study showed that the PSQ could be considered a parameter for predicting surgical success in patients with LDH, and can be useful in clinical practice.

Extraction of Trees Stem Diameters at Breast Height by Terrestrial Laser Sensor for Selective Cutting

Directory of Open Access Journals (Sweden)

Yili ZHENG

2014-02-01

Full Text Available In order to assist the operators of the logging harvester automatically and quickly select the appropriate trees for selective cutting, using two-dimensional laser scanner and inertial measurement system, the two-dimensional cloud points of the trunks at breast-height are obtained for several trees. After projection, clustering, linear transformation and fitting for the point clouds data, the parameters of the breast-height-diameters and center locations of the trees are obtained. The calculation is implemented in MATLAB by Polak-Ribiere-Polyak (PRP conjugate gradient algorithm and the result is shown in VC++ environment. Using this method, absolute errors of the breast-height- diameters and center locations are 2.3 cm and (12.4, 11.4 cm respectively, and meet the requirements on the automatically selective cutting of the logging harvester.

ADVANCED CUTTINGS TRANSPORT STUDY

Energy Technology Data Exchange (ETDEWEB)

Stefan Miska; Nicholas Takach; Kaveh Ashenayi

2004-07-31

We have tested the loop elevation system. We raised the mast to approximately 25 to 30 degrees from horizontal. All went well. However, while lowering the mast, it moved laterally a couple of degrees. Upon visual inspection, severe spalling of the concrete on the face of the support pillar, and deformation of the steel support structure was observed. At this time, the facility is ready for testing in the horizontal position. A new air compressor has been received and set in place for the ACTS test loop. A new laboratory has been built near the ACTS test loop Roughened cups and rotors for the viscometer (RS300) were obtained. Rheologies of aqueous foams were measured using three different cup-rotor assemblies that have different surface roughness. The relationship between surface roughness and foam rheology was investigated. Re-calibration of nuclear densitometers has been finished. The re-calibration was also performed with 1% surfactant foam. A new cuttings injection system was installed at the bottom of the injection tower. It replaced the previous injection auger. A mechanistic model for cuttings transport with aerated mud has been developed. Cuttings transport mechanisms with aerated water at various conditions were experimentally investigated. A total of 39 tests were performed. Comparisons between the model predictions and experimental measurements show a satisfactory agreement. Results from the ultrasonic monitoring system indicated that we could distinguish between different sand levels. We also have devised ways to achieve consistency of performance by securing the sensors in the caps in exactly the same manner as long as the sensors are not removed from the caps. A preliminary test was conducted on the main flow loop at 100 gpm flow rate and 20 lb/min cuttings injection rate. The measured bed thickness using the ultrasonic method showed a satisfactory agreement with nuclear densitometer readings. Thirty different data points were collected after the test

ADVANCED CUTTINGS TRANSPORT STUDY

Energy Technology Data Exchange (ETDEWEB)

Stefan Miska; Troy Reed; Ergun Kuru

2004-09-30

The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation system. In parallel with the flow loop construction, hydraulics and cuttings transport studies were preformed using drilling foams and aerated muds. In addition, hydraulics and rheology of synthetic drilling fluids were investigated. The studies were performed under ambient and EPET conditions. The effects of temperature and pressure on the hydraulics and cuttings transport were investigated. Mechanistic models were developed to predict frictional pressure loss and cuttings transport in horizontal and near-horizontal configurations. Model predictions were compared with the measured data. Predominantly, model predictions show satisfactory agreements with the measured data. As a

Impact of Cutting Forces and Chip Microstructure in High Speed Machining of Carbon Fiber – Epoxy Composite Tube

Directory of Open Access Journals (Sweden)

Roy Y. Allwin

2017-09-01

Full Text Available Carbon fiber reinforced polymeric (CFRP composite materials are widely used in aerospace, automobile and biomedical industries due to their high strength to weight ratio, corrosion resistance and durability. High speed machining (HSM of CFRP material is needed to study the impact of cutting parameters on cutting forces and chip microstructure which offer vital inputs to the machinability and deformation characteristics of the material. In this work, the orthogonal machining of CFRP was conducted by varying the cutting parameters such as cutting speed and feed rate at high cutting speed/feed rate ranges up to 346 m/min/ 0.446 mm/rev. The impact of the cutting parameters on cutting forces (principal cutting, feed and thrust forces and chip microstructure were analyzed. A significant impact on thrust forces and chip segmentation pattern was seen at higher feed rates and low cutting speeds.

Cutting Cosmos

DEFF Research Database (Denmark)

Mikkelsen, Henrik Hvenegaard

For the first time in over 30 years, a new ethnographic study emerges on the Bugkalot tribe, more widely known as the Ilongot of the northern Philippines. Exploring the notion of masculinity among the Bugkalot, Cutting Cosmos is not only an experimental, anthropological study of the paradoxes...... around which Bugkalot society revolves, but also a reflection on anthropological theory and writing. Focusing on the transgressive acts through which masculinity is performed, this book explores the idea of the cosmic cut, the ritual act that enables the Bugkalot man to momentarily hold still the chaotic...

Gaussian-2 theory: Use of higher level correlation methods, quadratic configuration interaction geometries, and second-order Moller--Plesset zero-point energies

International Nuclear Information System (INIS)

Curtiss, L.A.; Raghavachari, K.; Pople, J.A.

1995-01-01

The performance of Gaussian-2 theory is investigated when higher level theoretical methods are included for correlation effects, geometries, and zero-point energies. A higher level of correlation treatment is examined using Brueckner doubles [BD(T)] and coupled cluster [CCSD(T)] methods rather than quadratic configuration interaction [QCISD(T)]. The use of geometries optimized at the QCISD level rather than the second-order Moller--Plesset level (MP2) and the use of scaled MP2 zero-point energies rather than scaled Hartree--Fock (HF) zero-point energies have also been examined. The set of 125 energies used for validation of G2 theory [J. Chem. Phys. 94, 7221 (1991)] is used to test out these variations of G2 theory. Inclusion of higher levels of correlation treatment has little effect except in the cases of multiply-bonded systems. In these cases better agreement is obtained in some cases and poorer agreement in others so that there is no improvement in overall performance. The use of QCISD geometries yields significantly better agreement with experiment for several cases including the ionization potentials of CS and O 2 , electron affinity of CN, and dissociation energies of N 2 , O 2 , CN, and SO 2 . This leads to a slightly better agreement with experiment overall. The MP2 zero-point energies gives no overall improvement. These methods may be useful for specific systems

Latest development of laser cutting

OpenAIRE

Wetzig, Andreas; Herwig, Patrick; Hauptmann, Jan; Goppold, Cindy; Baumann, Robert; Fürst, Andreas; Rose, Michael; Pinder, Thomas; Mahrle, Achim; Beyer, Eckhard

2016-01-01

Laser cutting was one of the first applications of laser material processing. Today, laser cutting is the most widespread application among laser material processing besides laser marking. Meanwhile, nearly each material can be cut by means of a laser, in particular since ultra short pulse lasers are available in the power range of up to 100 W. The to be cut material can come with thicknesses from a few microns till tens of millimeters as flat stock or as free form shapes. The paper will conc...

Relative abundance and species richness of cerambycid beetles in partial cut and uncut bottomland hardwood forests

Science.gov (United States)

Newell, P.; King, S.

2009-01-01

Partial cutting techniques are increasingly advocated and used to create habitat for priority wildlife. However, partial cutting may or may not benefit species dependent on deadwood; harvesting can supplement coarse woody debris in the form of logging slash, but standing dead trees may be targeted for removal. We sampled cerambycid beetles during the spring and summer of 2006 and 2007 with canopy malaise traps in 1- and 2-year-old partial cut and uncut bottomland hardwood forests of Louisiana. We captured a total of 4195 cerambycid beetles representing 65 species. Relative abundance was higher in recent partial cuts than in uncut controls and with more dead trees in a plot. Total species richness and species composition were not different between treatments. The results suggest partial cuts with logging slash left on site increase the abundance of cerambycid beetles in the first few years after partial cutting and that both partial cuts and uncut forest should be included in the bottomland hardwood forest landscape.

CALCULATION OF LASER CUTTING COSTS

Directory of Open Access Journals (Sweden)

Bogdan Nedic

2016-09-01

Full Text Available The paper presents description methods of metal cutting and calculation of treatment costs based on model that is developed on Faculty of mechanical engineering in Kragujevac. Based on systematization and analysis of large number of calculation models of cutting with unconventional methods, mathematical model is derived, which is used for creating a software for calculation costs of metal cutting. Software solution enables resolving the problem of calculating the cost of laser cutting, comparison' of costs made by other unconventional methods and provides documentation that consists of reports on estimated costs.

Genetic consequences of selection cutting on sugar maple (Acer saccharum Marshall).

Science.gov (United States)

Graignic, Noémie; Tremblay, Francine; Bergeron, Yves

2016-07-01

Selection cutting is a treatment that emulates tree-by-tree replacement for forests with uneven-age structures. It creates small openings in large areas and often generates a more homogenous forest structure (fewer large leaving trees and defective trees) that differs from old-growth forest. In this study, we evaluated whether this type of harvesting has an impact on genetic diversity of sugar maple (Acer saccharum Marshall). Genetic diversity among seedlings, saplings, and mature trees was compared between selection cut and old-growth forest stands in Québec, Canada. We found higher observed heterozygosity and a lower inbreeding coefficient in mature trees than in younger regeneration cohorts of both forest types. We detected a recent bottleneck in all stands undergoing selection cutting. Other genetic indices of diversity (allelic richness, observed and expected heterozygosity, and rare alleles) were similar between forest types. We concluded that the effect of selection cutting on the genetic diversity of sugar maple was recent and no evidence of genetic erosion was detectable in Québec stands after one harvest. However, the cumulative effect of recurring applications of selection cutting in bottlenecked stands could lead to fixation of deleterious alleles, and this highlights the need for adopting better forest management practices.

Development Potential, in a Greenhouse, of Cuttings of the Hybrid Eucalyptus grandis x Eucalyptus camaldulensis

Directory of Open Access Journals (Sweden)

M. N. Garcia

2013-03-01

Full Text Available Abstract: This study evaluated the potential for development in the greenhouse, cuttings of the hybrid of Eucalyptus grandis x Eucalyptus camaldulensis in Sinop - Mato Grosso and generated equations to estimate the percentage of rooting parameters. Were measured: the percentage of cuttings with some degree of modification, the percentage of cuttings in the percentage of cuttings with roots larger than 10 cm in length. Also measured was the neck diameter, height and leaf area index. The heights and leaf area showed lower development within the greenhouse. The rooting potential is based on curve speed of rooting and was found 12 days after staking. The identification of the optimal point of withdrawal of the shoots of the greenhouse through the intercept curves daily current increase curve (DCI e daily average increase (DAI, being 19 days after staking. The company derives the stakes with 24 days underdoing the potential of the species and structures used.Keywords: Eucalyptus, greenhouse management and rooting

Tubing and cable cutting tool

Science.gov (United States)

Mcsmith, D. D.; Richardson, J. I. (Inventor)

1984-01-01

A hand held hydraulic cutting tool was developed which is particularly useful in deactivating ejection seats in military aircraft rescue operations. The tool consists primarily of a hydraulic system composed of a fluid reservoir, a pumping piston, and an actuator piston. Mechanical cutting jaws are attached to the actuator piston rod. The hydraulic system is controlled by a pump handle. As the pump handle is operated the actuator piston rod is forced outward and thus the cutting jaws are forced together. The frame of the device is a flexible metal tubing which permits easy positioning of the tool cutting jaws in remote and normally inaccessible locations. Bifurcated cutting edges ensure removal of a section of the tubing or cable to thereby reduce the possibility of accidental reactivation of the tubing or cable being severed.

Cutting concrete with abrasion jet

International Nuclear Information System (INIS)

Yie, G.G.

1982-01-01

Fluidyne Corporation has developed a unique process and apparatus that allow selected abrasives to be introduced into high-speed waterjet to produce abrasive-entrained waterjet that has high material-cutting capabilities, which is termed by Fluidyne as the Abrasion Jet. Such Abrasion Jet has demonstrated capability in cutting hard rock and concrete at a modest pressure of less than 1360 bars (20,000 psi) and a power input of less than 45 kW (60 horsepower). Abrasion Jet cutting of concrete is characterized by its high rate of cutting, flexible operation, good cut quality, and relatively low costs. This paper presents a general description of this technology together with discussions of recent test results and how it could be applied to nuclear decontamination and decommissioning work. 8 references

ADVANCED CUTTINGS TRANSPORT STUDY

Energy Technology Data Exchange (ETDEWEB)

Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mengjiao Yu; Ramadan Ahmed; Mark Pickell; Len Volk; Lei Zhou; Zhu Chen; Aimee Washington; Crystal Redden

2003-09-30

The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.

The effects of first-year shoot cut back on willow biomass production during the first and second cutting cycle; Effekter av skottnedklippning efter etableringsaaret paa produktionen under foersta och andra omdrevet i salixodlingar

Energy Technology Data Exchange (ETDEWEB)

Verwijst, Theo; Nordh, Nils-Erik

2010-05-15

During the early phase of commercialisation of willow short rotation forestry in Sweden it was considered to be important to cut down the shoots after the establishment year, and this practice still is maintained today. Several reasons then were put forward for cutting down. The primary goal was to stimulate sprouting of more shoots, thereby obtaining a rapidly closing stand which could compete with weeds. Another reason was that it would enable weed control during the second year. In some of the older clones, which exhibited bow-shaped shoots, cutting down was supposed to lead to more straight growing shoots which rendered less biomass loss at harvest. In the meantime, the practice of cutting down has been abandoned in Denmark, and there are reasons to scrutinise the effects of cutting down on available biomass production figures from Swedish field trials. The main goal with this project was to try to quantify the effects of cutting down on the biomass productivity of willow during the first and later cutting cycles. Thus far, efforts in this research topic have not led to a scientifically documented quantification on the effects, and therefore a scientific basis for hands-on recommendations to willow growers is lacking. The purpose of our work consequently was to generate practical recommendations with regard to the management measure of cutting down, and the audience targeted consisted of willow growers (farmers, land-owners and entrepreneurs) who are deciding about and perform the actual management of willow stands to obtain higher yields. This information also is of large relevance for all extension workers in willow growing. Data have been collected from a field trial which was planted in Flosta, Enkoeping, in 2005. As this was the only experiment on cutting down which ran during the project period, we searched the archives which contained material from another experiment which ran from 1992 to 1996 in Ultuna, Uppsala, and from which some date were collected

Role of Auxin and Microclimate on the Success of Rooted Cuttings of Cocoa

Directory of Open Access Journals (Sweden)

Adi Prawoto

2007-05-01

Full Text Available In Indonesia, cocoa reproduction by cuttings is undeveloped yet because the available technology is more expensive than the other clonal reproduction methods. The success of cocoa cuttings is influenced by genetic and environmental factors. The purpose of this research is to study effect of endogenous auxin content, effects of light intensity and exogenous auxin application, on the rooted cuttings. The 2 nd research purpose is to study effects of PVP (Polyvinylpyrrolidon and IBA (β-indole-butyric acid, clones, and microclimate. The experiment was conducted in Kaliwining Experimental Station of Indonesian Coffee and Cocoa Research Institute in Jember (45 m a.s.l. and D rainfall type according to Schmidt Ferguson. The design for the 1 st experiment was splitsplit plot, replicated three times. The main plot was light intensity inside the roof, i.e.15%, 30%, and 45% to direct sun radiation. The sub plot was cocoa clones, i.e. DR 2 and ICS 13, and the sub-sub plot was IBA concentration, i.e. 0 ppm, 1500 ppm, 3000 ppm and 4500 ppm. The 2 nd experiment was designed factorial 3 x 3 of CRD, replicated 3 times. Clones of KW 163, KW 162 and KW 165, and IBA at 0, 3000, and 6000 ppm were the factors. In the same time, effect of IBA 6000 ppm, PVP 6000 ppm IBA+PVP 6000 ppm, and control were observed using KW 165 clone, and designed in complete randomized design (CRD, replicated 3 times. The result showed that auxin content of ICS 13 was higher than DR 2 (62.67 ppm vs 40.90 ppm so that gave higher rooted cuttings and more root number. Exogenous application of IBA improved auxin content of the cutting materials and promoted root growth. The optimum IBA concentration for root number was 3500 ppm. Light intensity of 45% improved number of rooted cuttings three times compared to 15%, however compared to the 2 nd research, percentage of rooted cuttings was still very low. Cocoa cutting method to gain rooted cuttings 80—90% has been obtained. The method was using

Rebuilding conveyor transfer points to cut fugitive material and improve operations

Energy Technology Data Exchange (ETDEWEB)

Stahura, R P [Martin Engineering Company, Neponset, MA (USA)

1992-10-01

The article describes a three-part programme to control spillage and prevent fugitive material at conveyor transfer points. The three parts are: adequate belt support; the installation of a wear line inside the chute to preserve the rubber seal system; and the maintenance of an effective edge seal. The article also discusses designing for ease of maintenance. 9 figs.

Using internally cooled cutting tools in the machining of difficult-to-cut materials based on Waspaloy

Directory of Open Access Journals (Sweden)

Yahya Isik

2016-05-01

Full Text Available Nickel-based superalloys such as Waspaloy are used for engine components and in the nuclear industry, where considerable strength and corrosion resistance at high operating temperatures are called for. These characteristics of such alloys cause increases in cutting temperature and resultant tool damage, even at low cutting speeds and low feed rates. Thus, they are classified as difficult-to-cut materials. This article presents a cooling method to be used in metal cutting based on a tool holder with a closed internal cooling system with cooling fluid circulating inside. Hence, a green cooling method that does not harm the environment and is efficient in removing heat from the cutting zone was developed. A series of cutting experiments were conducted to investigate the practicality and effectiveness of the internally cooled tool model. The developed system achieved up to 13% better surface quality than with dry machining, and tool life was extended by 12%. The results clearly showed that with the reduced cutting temperature of the internal cooling, it was possible to control the temperature and thus prevent reaching the critical cutting temperature during the turning process, which is vitally important in extending tool life during the processing of Waspaloy.

A Cutting Pattern Recognition Method for Shearers Based on Improved Ensemble Empirical Mode Decomposition and a Probabilistic Neural Network

Directory of Open Access Journals (Sweden)

Jing Xu

2015-10-01

Full Text Available In order to guarantee the stable operation of shearers and promote construction of an automatic coal mining working face, an online cutting pattern recognition method with high accuracy and speed based on Improved Ensemble Empirical Mode Decomposition (IEEMD and Probabilistic Neural Network (PNN is proposed. An industrial microphone is installed on the shearer and the cutting sound is collected as the recognition criterion to overcome the disadvantages of giant size, contact measurement and low identification rate of traditional detectors. To avoid end-point effects and get rid of undesirable intrinsic mode function (IMF components in the initial signal, IEEMD is conducted on the sound. The end-point continuation based on the practical storage data is performed first to overcome the end-point effect. Next the average correlation coefficient, which is calculated by the correlation of the first IMF with others, is introduced to select essential IMFs. Then the energy and standard deviation of the reminder IMFs are extracted as features and PNN is applied to classify the cutting patterns. Finally, a simulation example, with an accuracy of 92.67%, and an industrial application prove the efficiency and correctness of the proposed method.

Laser Cutting, Development Trends

DEFF Research Database (Denmark)

Olsen, Flemming Ove

1999-01-01

In this paper a short review of the development trends in laser cutting will be given.The technology, which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal, as it will expand in heavy industry and in cutting...... of 3-dimensional shapes.The CO2-laser will also in the near future be the dominating laser source in the market, although the new developments in ND-YAG-lasers opens for new possibilities for this laser type....

Water-Cut Sensor System

KAUST Repository

Karimi, Muhammad Akram; Shamim, Atif; Arsalan, Muhammad

2018-01-01

Provided in some embodiments is a method of manufacturing a pipe conformable water-cut sensors system. Provided in some embodiments is method for manufacturing a water-cut sensor system that includes providing a helical T-resonator, a helical ground

Effects of cutting and maturity on antioxidant activity of fresh-cut tomatoes

NARCIS (Netherlands)

Moreira Lana, M.; Tijskens, L.M.M.; Kooten, van O.

2005-01-01

To investigate the changes in total antioxidant activity of fresh-cut tomato during storage, tomato fruits harvested at three different stages of maturity were cut into 7-mm thick slices and stored at 5°C. Intact (control) fruits were stored in the same conditions. The antioxidant activity was

Wear of Cutting Tool with Excel Geometry in Turning Process of Hardened Steel

Science.gov (United States)

Samardžiová, Michaela

2016-09-01

This paper deals with hard turning using a cutting tool with Xcel geometry. This is one of the new geometries, and there is not any information about Xcel wear in comparison to the conventional geometry. It is already known from cutting tools producers that using the Xcel geometry leads to higher quality of machined surface, perticularly surface roughness. It is possible to achieve more than 4 times lower Ra and Rz values after turning than after using conventional geometry with radius. The workpiece material was 100Cr6 hardened steel with hardness of 60 ± 1 HRC. The machine used for the experiment was a lathe with counter spindle DMG CTX alpha 500, which is located in the Centre of Excellence of 5-axis Machining at the Faculty of Materials Science and Technology in Trnava. The cutting tools made by CBN were obtained from Sandvik COROMANT Company. The aim of this paper is to investigate the cutting tool wear in hard turning process by the Xcel cutting tool geometry.

Quality Analysis of Cutting Steel Using Laser

Directory of Open Access Journals (Sweden)

Vladislav Markovič

2013-02-01

Full Text Available The article explores the quality dependence of the edge surface of steel C45 LST EN 10083-1 obtained cutting the material using laser on different cutting regimes and variations in the thickness of trial steel. The paper presents the influence of the main modes of laser cutting equipment Trulaser 3030, including cutting speed, pressure, angle and the thickness of the surface on the quality characteristics of the sample. The quality of the edge after laser cutting is the most important indicator influencing such technological spread in industry worldwide. Laser cutting is the most popular method of material cutting. Therefore, the article focuses on cutting equipment, cutting defects and methods of analysis. Research on microstructure, roughness and micro-toughness has been performed with reference to edge samples. At the end of the publication, conclusions are drawn.Article in Lithuanian

Quality Analysis of Cutting Steel Using Laser

Directory of Open Access Journals (Sweden)

Vladislav Markovič

2012-12-01

Full Text Available The article explores the quality dependence of the edge surface of steel C45 LST EN 10083-1 obtained cutting the material using laser on different cutting regimes and variations in the thickness of trial steel. The paper presents the influence of the main modes of laser cutting equipment Trulaser 3030, including cutting speed, pressure, angle and the thickness of the surface on the quality characteristics of the sample. The quality of the edge after laser cutting is the most important indicator influencing such technological spread in industry worldwide. Laser cutting is the most popular method of material cutting. Therefore, the article focuses on cutting equipment, cutting defects and methods of analysis. Research on microstructure, roughness and micro-toughness has been performed with reference to edge samples. At the end of the publication, conclusions are drawn.Article in Lithuanian

New Modelling Strategies For Metal Cutting

International Nuclear Information System (INIS)

Rosa, Pedro A. R.; Martins, Paulo A. F.; Atkins, Anthony G.

2007-01-01

This paper draws from the 'plasticity and friction only' view of metal cutting to the presentation of new modelling strategies based on the interaction between finite elements and modern ductile fracture mechanics. The overall presentation is supported by specially designed orthogonal metal cutting experiments that were performed on Lead test specimens under laboratory-controlled conditions. Comparisons between theoretical predictions and experimental results comprise a wide range of topics such as material flow, cutting forces and specific cutting pressure. The paper demonstrates that while material flow and chip formation can be successfully modelled by traditional 'plasticity and friction only' analyses, the contribution of the fracture work involved in the formation of new surfaces is essential for obtaining good estimates of cutting forces and of the specific cutting pressure

Cutting method and device underwater

International Nuclear Information System (INIS)

Takano, Genta; Kamei, Hiromasa; Beppu, Seiji

1998-01-01

A place of material to be cut is surrounded by an openable/closable box. The material to be cut is cut underwater, and materials generated in this case are removed from the cut portion by a pressurized water jet. The removed materials are sucked and recovered together with water in the box. Among the materials caused by the cutting underwater, solid materials not floating on water are caused to stay in the midway of a sucking and recovering channel. A large sucking force might be required for the entire region of the sucking and recovering channel when sucking and recovering large sized solid materials not floating on water, but even large sized materials can be recovered easily according to the present invention since they are recovered after being sucked and stayed in the midway of the sucking and recovering channel. (N.H.)

Application of CO2 laser cutting machine to shipbuilding; Zosen no setsudan eno CO2 laser no tekiyo

Energy Technology Data Exchange (ETDEWEB)

Fujimoto, Y. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

1998-11-01

Carbon dioxide laser has been applied to cutting works in shipbuilding. As NC cutter was obsolete, CO2 laser cutting machine with a rated output 3 kW was introduced. According to the specifications of the machinable plate, the maximum thickness is 19 mm, and effective width and length are 5.4 m and 29.1 m, respectively. As the cutting width is wide and the running distance of laser beam is long, the error of light axis is expanded only by a small error of irradiation angle, which results in the inconvenience. Stable operation was realized by improving the fixation of reflecting mirror. Right angle cutting section with a cutting curve below 0.5 mm was obtained, and cutting time was reduced by the one-line cutting by which both sections can be available with a single cutting line. For the cutting of thin plate with a thickness less than 10 mm, strain was not formed, and remedy was not required. Block strain was remarkably reduced during the assembly process. Maintenance-free operation without monitoring can be performed for a long time. This machine is operated at night and lunch time, resulting in the reduced processes. The working environment is appropriate without noise and dust. Facility cost and maintenance cost were also reduced. Lower cutting speed is a weak point, when compared with the plasma cutting machine. The present machine is not applied to aluminum plates with high surface reflectivity. 13 figs.

Cutting zone area and chip morphology in high-speed cutting of titanium alloy Ti-6Al-4V

International Nuclear Information System (INIS)

Ke, Qing Chan; Xu, Daochun; Xiong, Dan Ping

2017-01-01

The titanium alloy Ti-6Al-4V has superior properties but poor machinability, yet is widely used in aerospace and biomedical industries. Chip formation and cutting zone area are important factors that have received limited attention. Thus, we propose a high-speed orthogonal cutting model for serrated chip formation. The high speed orthogonal cutting of Ti-6Al-4V was studied with a cutting speed of 10-160 m/min and a feed of 0.07-0.11 mm/r. Using theoretical models and experimental results, parameters such as chip shape, serration level, slip angle, and shear slip distance were investigated. Cutting zone boundaries (tool-chip contact length, length of shear plane, and critical slip plane) and cutting zone area were obtained. The results showed that discontinuous, long-curling, and continuous chips were formed at low, medium, and high speeds, respectively. Serration level, shear slip distance, and slip angle rose with increasing cutting speed. The length of shear plane, tool-chip contact, and critical slip plane varied subtly with increased cutting speed, and rose noticeably with increased feed. Cutting zone area grew weakly with increased cutting speed, levelling off at high cutting speed; however, it rose noticeably with increased feed. This study furthers our understanding of the shear slip phenomenon and the mechanism of serrated chip formation

Cutting zone area and chip morphology in high-speed cutting of titanium alloy Ti-6Al-4V

Energy Technology Data Exchange (ETDEWEB)

Ke, Qing Chan; Xu, Daochun; Xiong, Dan Ping [School of Technology, Beijing Forestry University, Beijing (China)

2017-01-15

The titanium alloy Ti-6Al-4V has superior properties but poor machinability, yet is widely used in aerospace and biomedical industries. Chip formation and cutting zone area are important factors that have received limited attention. Thus, we propose a high-speed orthogonal cutting model for serrated chip formation. The high speed orthogonal cutting of Ti-6Al-4V was studied with a cutting speed of 10-160 m/min and a feed of 0.07-0.11 mm/r. Using theoretical models and experimental results, parameters such as chip shape, serration level, slip angle, and shear slip distance were investigated. Cutting zone boundaries (tool-chip contact length, length of shear plane, and critical slip plane) and cutting zone area were obtained. The results showed that discontinuous, long-curling, and continuous chips were formed at low, medium, and high speeds, respectively. Serration level, shear slip distance, and slip angle rose with increasing cutting speed. The length of shear plane, tool-chip contact, and critical slip plane varied subtly with increased cutting speed, and rose noticeably with increased feed. Cutting zone area grew weakly with increased cutting speed, levelling off at high cutting speed; however, it rose noticeably with increased feed. This study furthers our understanding of the shear slip phenomenon and the mechanism of serrated chip formation.

Effects of cutting and maturity on antioxidant activity of fresh-cut tomatoes

NARCIS (Netherlands)

Moreira Lana, M.; Tijskens, L.M.M.

2006-01-01

To investigate the changes in total antioxidant activity of fresh-cut tomato during storage, tomato fruits harvested at three different stages of maturity were cut into 7-mm thick slices and stored at 5 °C. Intact fruits were stored in the same conditions as a control. The antioxidant activity was

Fresh weight and doses of IAA on rooting of goldenrod cuttings

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Moisés Alves Muniz

2015-04-01

Full Text Available The objective of this work was to evaluate the influence of indole acetic acid (IAA on fresh weight of cuttings and in the rooting of goldenrod. The first experiment was arranged in randomized blocks in factorial scheme 5 x 3, and 5 doses of IAA at 0, 500, 1000, 2000 and 3000 mg/L and three evaluation periods (7, 14 and 21 days after staking-DAS with six replications. The second experiment was also established in randomized blocks in factorial scheme 4 x 2, with 4 class of fresh weight (0.5-0.7, 0.71-0.9, 0.91-1.10 and greater than 1.10 g in the presence or absence of indol butyric acid (IBA and two evaluation periods (14, 21 days after staking, with six replications. In both experiments, the stakes were standardized to 5 cm. In the first experiment the stakes were 1 cm from its base immersed for 30 seconds in different water-alcohol solutions of IAA, while the second base of the cuttings were immersed in water, and then the powder containing 2000 mg/kg of IBA, and subsequently placed for rooting in trays with 256 cells (45 mL. Number of roots/cutting, rooting and survival of seedlings were determined. The presence or absence of IAA or IBA does not affect the rooting of cuttings and even the survival of seedlings. There was no effect on rooting cycle suggesting that the dosage is 2000 mg/L of IAA, because it provided higher number of roots/cutting, while the increase in fresh weight of cuttings provided to increase the number of roots/cuttings.

Formation of Quenching Structures in the Steel 35 by Deform Cutting

Directory of Open Access Journals (Sweden)

A. G. Degtyareva

2014-01-01

Full Text Available In industry different methods of surface hardening are widely used to increase reliability and durability of friction unit parts. Among these methods are areas of focus based on deformcutting technology (DC i.e. method of chip-free mechanical treatment.It is shown that DC method allows us to produce through- or partial-hardening surface layers of a large thickness (0,4…1.5mm on steel with no additional heat sources. The standard metal-cutting equipment and common tools are used for deform-cutting process.The significant heat generation in the deform-cutting zone and mechanical effect from the tool allow us to heat undercut layers to the phase transformation point to have the hardening structure as a result of heat removal to the cold balk. The hardening structure formation occurs at significant heating and cooling rate (106C/c with large degrees and rates of strain.The deform-cutting modes and working face tool grinding determine the type and properties of the hardening structure. To produce the hardening structure would require the heat transfer and force action augmentation while treatment.These researches deal with through- and partial surface hardening samples produced by turning steel 35 shafts. While through hardening the phase transformation carry among the whole thickness of the undercut layer; while partial hardening the hardening interlayer formed on the side of the cutting tool contact.The depth of hardening zone of samples with through hardening layers is 0,5 mm; the depth of hardening zone of partial hardening samples is 0,8 mm. Micro-hardness of the through hardening layers is 653 HV0,1 and 485 HV0,1 for the partial hardening layers. The metallographic analysis shows that the hardening zone formed while deform cutting has disperse structure; there are ferrite ghosts in it.The tempering at temperatures of 200 – 700C showed that the micro-hardness of the hardening structures formed while deform cutting is larger than the micro

Test tube systems with cutting/recombination operations

Energy Technology Data Exchange (ETDEWEB)