The screening of particles with different vibration modes was simulated by means of a 3D discrete element method (3D-DEM). The motion and penetration of the particles on the screen deck were analyzed for linear, circu...The screening of particles with different vibration modes was simulated by means of a 3D discrete element method (3D-DEM). The motion and penetration of the particles on the screen deck were analyzed for linear, circular and elliptical vibration of the screen. The results show that the travel velocity of the particles is the fastest, but the screening efficiency is the lowest, for the linear vibration mode. The circular motion resulted in the highest screening efficiency, but the lowest particle travel velocity. In the steady state the screening efficiency for each mode is seen to increase gradually along the longitudinal direction of the deck. The screening efficiency increment of the circular mode is the largest while the linear mode shows the smallest increment. The volume fraction of near-mesh size particles at the underside is larger than that of small size particles all along the screen deck. Linear screening mode has more near-mesh and small size particles on the first three deck sections, and fewer on the last two sections, compared to the circular or elliptical modes.展开更多
The purpose of this study is to improve the surface properties of austenitic stainless steel using the double-folded electrode screen plasma nitriding (SPN) process. In general, the S-phase is well-known for its excel...The purpose of this study is to improve the surface properties of austenitic stainless steel using the double-folded electrode screen plasma nitriding (SPN) process. In general, the S-phase is well-known for its excellent properties such as improved hardness and wear resistance along with sustained corrosion resistance. The concentrated nitrogen via SPN process was injected to form S-phase with time at 713 K. This study was carried out under the conditions of 44 at% of nitrogen injection, which was higher than 25 at% known as the condition of no precipitation of S-phase formed by the SPN process, and 20 K higher than the maximum temperature without precipitation phase. The hardness analysis of stainless steel sample treated by the SPN process at 713 K showed a much higher value than the typical nitriding hardness at a depth of lower nitrogen than the maximum nitrogen concentration. The SPN 20 hr treated specimen showed the average value of 2339 HV while 40 hr showed the average value of 2215 HV. The result is attributed to the concentrated nitrogen formed in the SPN process reacting with the alloying elements contained in the base material to form fine precipitates, thus producing a synergy effect of the extreme hardening effect;that is, the movement of precipitates and dislocations due to the GP-zone (Guinier-Preston zone).展开更多
Moebius syndrome is a rare disorder primarily characterized by congenital facial palsy, frequently accompanied by ocular abduction anomalies and occasionally associated with orofacial, limb and musculoskeletal malform...Moebius syndrome is a rare disorder primarily characterized by congenital facial palsy, frequently accompanied by ocular abduction anomalies and occasionally associated with orofacial, limb and musculoskeletal malformations. Abnormal development of cranial nerves Ⅴ through Ⅻ underlines the disease pathogenesis. Although a genetic etiology for Moebius syndrome was proposed, molecular genetic studies to identify the causative gene（s） are scarce. In this study, we selected two candidate genes. One is BASP1 residing in a human chromosome 5p15.1-p15.2, syntenic to mouse chromosome 15qA2-qB2, to which a mouse model with facial nerve anomalies was mapped. The other is transcribed processed pseudogene TPψg-BASP1, which is located on chromosome 13q flanking the putative locus for Moebius syndrome and might be involved in the regulation of the transcripts encoded by BASP1. Mutation analyses in nineteen patients excluded these genes as being candidates for Moebius syndrome.展开更多
The ideal motion characteristics for the vibrating screen was presented according to the principle of screening process with constant bed thickness.A new vibrating screen with variable elliptical trace was proposed.An...The ideal motion characteristics for the vibrating screen was presented according to the principle of screening process with constant bed thickness.A new vibrating screen with variable elliptical trace was proposed.An accurate mechanical model was constructed according to the required structural motion features.Applying multi-degree-of-freedom vibration theory,characteristics of the vibrating screen was analyzed.Kinematics parameters of the vibrating screen which motion traces were linear,circular or elliptical were obtained.The stable solutions of the dynamic equations gave the motions of the vibrating screen by means of computer simulations.Technological parameters,including amplitude,movement velocity and throwing index,of five specific points along the screen surface were gained by theoretical calculation.The results show that the traces of the new designed vibrating screen follow the ideal screening motion.The screening efficiency and processing capacity may thus be effectively improved.展开更多
AIM:To present a content-based image retrieval(CBIR) system that supports the classification of breast tissue density and can be used in the processing chain to adapt parameters for lesion segmentation and classificat...AIM:To present a content-based image retrieval(CBIR) system that supports the classification of breast tissue density and can be used in the processing chain to adapt parameters for lesion segmentation and classification.METHODS:Breast density is characterized by image texture using singular value decomposition(SVD) and histograms.Pattern similarity is computed by a support vector machine(SVM) to separate the four BI-RADS tissue categories.The crucial number of remaining singular values is varied(SVD),and linear,radial,and polynomial kernels are investigated(SVM).The system is supported by a large reference database for training and evaluation.Experiments are based on 5-fold cross validation.RESULTS:Adopted from DDSM,MIAS,LLNL,and RWTH datasets,the reference database is composed of over 10000 various mammograms with unified and reliable ground truth.An average precision of 82.14% is obtained using 25 singular values(SVD),polynomial kernel and the one-against-one(SVM).CONCLUSION:Breast density characterization using SVD allied with SVM for image retrieval enable the development of a CBIR system that can effectively aid radiologists in their diagnosis.展开更多
Objective: To test the feasibility of a fully paperless system, termed “paperlite” in a UK breast screening service. To demonstrate in NHS practice, how workload and workflow could be improved by moving to a paperle...Objective: To test the feasibility of a fully paperless system, termed “paperlite” in a UK breast screening service. To demonstrate in NHS practice, how workload and workflow could be improved by moving to a paperless system and discovering what impact this has upon the complexity within the service. Setting: Warwickshire, Solihull and Coventry Breast Screening Service in the West Midlands of England. Methods: Quality improvement methodologies were employed, including value stream mapping, task analysis and a time-and-motion study. Results: The screening centred screened approximately 50,000 women per year. If they were to implement a paperless system, the administrative workload would decrease. The time saving per batch of screens, which could be achieved by moving to the paperless system ranged from 19 to 56 minutes (mean = 36 minutes). When calculated by batch the mean time saving per woman screened by moving to the paperless system was 42 seconds. This equates to 583 hours of administrative work per year in a centre screening 50,000 women. Conclusions: The paperless system has many benefits compared to the original system in terms of reductions in waste, time and cost. The simplification and standardisation of the process resulted in fewer tasks and interfaces where errors could occur, hence inadvertently improving patient safety. The limitation of the work is the heavy reliance on technology, live interfacing with computer databases and software stability is necessary for a paperless system to be used in NHS practice.展开更多
基金financial support from the National Natural Science Foundation of China (No. 51204181)the Research Fund for the Doctoral Program of Higher Education of China (No.20110095120004)+1 种基金the Fundamental Research Funds for the Central Universities (Nos. 2011QNA10 and 2010QNB17)the China Postdoctoral Science Foundation (No. 20110491485) for this work
文摘The screening of particles with different vibration modes was simulated by means of a 3D discrete element method (3D-DEM). The motion and penetration of the particles on the screen deck were analyzed for linear, circular and elliptical vibration of the screen. The results show that the travel velocity of the particles is the fastest, but the screening efficiency is the lowest, for the linear vibration mode. The circular motion resulted in the highest screening efficiency, but the lowest particle travel velocity. In the steady state the screening efficiency for each mode is seen to increase gradually along the longitudinal direction of the deck. The screening efficiency increment of the circular mode is the largest while the linear mode shows the smallest increment. The volume fraction of near-mesh size particles at the underside is larger than that of small size particles all along the screen deck. Linear screening mode has more near-mesh and small size particles on the first three deck sections, and fewer on the last two sections, compared to the circular or elliptical modes.
文摘The purpose of this study is to improve the surface properties of austenitic stainless steel using the double-folded electrode screen plasma nitriding (SPN) process. In general, the S-phase is well-known for its excellent properties such as improved hardness and wear resistance along with sustained corrosion resistance. The concentrated nitrogen via SPN process was injected to form S-phase with time at 713 K. This study was carried out under the conditions of 44 at% of nitrogen injection, which was higher than 25 at% known as the condition of no precipitation of S-phase formed by the SPN process, and 20 K higher than the maximum temperature without precipitation phase. The hardness analysis of stainless steel sample treated by the SPN process at 713 K showed a much higher value than the typical nitriding hardness at a depth of lower nitrogen than the maximum nitrogen concentration. The SPN 20 hr treated specimen showed the average value of 2339 HV while 40 hr showed the average value of 2215 HV. The result is attributed to the concentrated nitrogen formed in the SPN process reacting with the alloying elements contained in the base material to form fine precipitates, thus producing a synergy effect of the extreme hardening effect;that is, the movement of precipitates and dislocations due to the GP-zone (Guinier-Preston zone).
基金supported by the Research Fund of the Istanbul University, Turkey (No. 480 [2359/2006])
文摘Moebius syndrome is a rare disorder primarily characterized by congenital facial palsy, frequently accompanied by ocular abduction anomalies and occasionally associated with orofacial, limb and musculoskeletal malformations. Abnormal development of cranial nerves Ⅴ through Ⅻ underlines the disease pathogenesis. Although a genetic etiology for Moebius syndrome was proposed, molecular genetic studies to identify the causative gene（s） are scarce. In this study, we selected two candidate genes. One is BASP1 residing in a human chromosome 5p15.1-p15.2, syntenic to mouse chromosome 15qA2-qB2, to which a mouse model with facial nerve anomalies was mapped. The other is transcribed processed pseudogene TPψg-BASP1, which is located on chromosome 13q flanking the putative locus for Moebius syndrome and might be involved in the regulation of the transcripts encoded by BASP1. Mutation analyses in nineteen patients excluded these genes as being candidates for Moebius syndrome.
基金Projects 50574091 and 50774084 supported by the National Natural Science Foundation of China
文摘The ideal motion characteristics for the vibrating screen was presented according to the principle of screening process with constant bed thickness.A new vibrating screen with variable elliptical trace was proposed.An accurate mechanical model was constructed according to the required structural motion features.Applying multi-degree-of-freedom vibration theory,characteristics of the vibrating screen was analyzed.Kinematics parameters of the vibrating screen which motion traces were linear,circular or elliptical were obtained.The stable solutions of the dynamic equations gave the motions of the vibrating screen by means of computer simulations.Technological parameters,including amplitude,movement velocity and throwing index,of five specific points along the screen surface were gained by theoretical calculation.The results show that the traces of the new designed vibrating screen follow the ideal screening motion.The screening efficiency and processing capacity may thus be effectively improved.
基金Supported by CNPq-Brazil,Grants 306193/2007-8,471518/ 2007-7,307373/2006-1 and 484893/2007-6,by FAPEMIG,Grant PPM 347/08,and by CAPESThe IRMA project is funded by the German Research Foundation(DFG),Le 1108/4 and Le 1108/9
文摘AIM:To present a content-based image retrieval(CBIR) system that supports the classification of breast tissue density and can be used in the processing chain to adapt parameters for lesion segmentation and classification.METHODS:Breast density is characterized by image texture using singular value decomposition(SVD) and histograms.Pattern similarity is computed by a support vector machine(SVM) to separate the four BI-RADS tissue categories.The crucial number of remaining singular values is varied(SVD),and linear,radial,and polynomial kernels are investigated(SVM).The system is supported by a large reference database for training and evaluation.Experiments are based on 5-fold cross validation.RESULTS:Adopted from DDSM,MIAS,LLNL,and RWTH datasets,the reference database is composed of over 10000 various mammograms with unified and reliable ground truth.An average precision of 82.14% is obtained using 25 singular values(SVD),polynomial kernel and the one-against-one(SVM).CONCLUSION:Breast density characterization using SVD allied with SVM for image retrieval enable the development of a CBIR system that can effectively aid radiologists in their diagnosis.
文摘Objective: To test the feasibility of a fully paperless system, termed “paperlite” in a UK breast screening service. To demonstrate in NHS practice, how workload and workflow could be improved by moving to a paperless system and discovering what impact this has upon the complexity within the service. Setting: Warwickshire, Solihull and Coventry Breast Screening Service in the West Midlands of England. Methods: Quality improvement methodologies were employed, including value stream mapping, task analysis and a time-and-motion study. Results: The screening centred screened approximately 50,000 women per year. If they were to implement a paperless system, the administrative workload would decrease. The time saving per batch of screens, which could be achieved by moving to the paperless system ranged from 19 to 56 minutes (mean = 36 minutes). When calculated by batch the mean time saving per woman screened by moving to the paperless system was 42 seconds. This equates to 583 hours of administrative work per year in a centre screening 50,000 women. Conclusions: The paperless system has many benefits compared to the original system in terms of reductions in waste, time and cost. The simplification and standardisation of the process resulted in fewer tasks and interfaces where errors could occur, hence inadvertently improving patient safety. The limitation of the work is the heavy reliance on technology, live interfacing with computer databases and software stability is necessary for a paperless system to be used in NHS practice.
