A NDT&E Methodology Based on Magnetic Representation for Surface Topography of Ferromagnetic Materials

Accurate evaluation is the final aim of nondestructive testing (NDT). However, the present electromagnetic NDT methods are commonly used to check the existence of defects, and all the tested targets only consist of concave defects (i.e., section-loss defects), such as holes, cracks, or corrosions, failing to evaluate the tested surface topography, which mainly consists of concave-shaped and bump-shaped features. At present, it is accepted that the commonly observed signals of the defects mainly manifest themselves in a single-/double-peak wave and their up/down directions of the peak wave can be easily changed just by changing the directions of either applied magnetization or pick-up units even for one defect. Unlike the present stylus and optical methods for surface topography inspections, a new electromagnetic NDT and evaluation (NDT&E) methodology is provided based on the accurate magnetic representation of surface topography, in which a concave-shaped feature produces “positive” magnetic flux leakages (MFLs) and therefore forms a “raised” signal wave but a bump-shaped feature generates “negative” magnetic fields and therefore leads to a “sunken” signal wave. In this case, the corresponding relationships between wave features and surface topography are presented and the relevant evaluation system for testing surface topography (concave, bumped, and flat features) is built. The provided methodology was analyzed and verified by finite element and experimental methods. Meanwhile, the different dimension parameters of height/depth and width of surface topography are further studied

A New Method of SHM for Steel Wire Rope and its Apparatus

Steel wire ropes often operate in a high‐speed swing status in practical engineering, and the reliable structural health monitoring (SHM) for them directly relates to human lives; however, they are usually beyond the capability of present portable magnet magnetic flux leakage (MFL) sensors based on yoke magnetic method due to its strong magnetic force and large weight. Unlike the yoke method, a new method of SHM for steel wire rope is proposed by theoretical analyses and also verified by finite element method (FEM) and experiments, which features much weaker magnetic interaction force and similar magnetization capability compared to the traditional yoke method. Meanwhile, the relevant detection apparatus or sensor is designed by simulation optimization. Furthermore, experimental comparisons between the new and yoke sensors for steel wire rope inspection are also conducted, which successfully confirm the characterization of smaller magnetic interaction force, less wear, and damage in contrast with traditional technologies. Finally, methods for SHM of steel wire rope and apparatus are discussed, which demonstrate the good practicability for SHM of steel wire rope under poor working conditions

PICS - a Performance-analysis-based Introspective Control System to steer parallel applications

Parallel programming has always been difficult due to the complexity of hardware and the diversity of applications. Although significant progress has been achieved over the years, attaining high parallel efficiency on large supercomputers for various applications is still quite challenging. As we go beyond the current scale of computers to those with peak capacities of an ExaFLOP/s, it is clear that an introspective and adaptive runtime system (RTS) will be critical to reduce programmers' tuning efforts by automatically handling the complexities of applications and machines. This is the motivation for my research on a Performance-analysis-based Introspective Control System - PICS. PICS intelligently steers parallel applications and runtime system configurations to achieve desired goals by utilizing expert knowledge to analyze performance data and adaptively reconfiguring applications. This thesis designs a holistic introspective control system for automatic performance tuning that combines the real-time performance analysis and performance steering to effectively automate the optimization. A few techniques are explored to make the parallel runtime system and applications more adaptive and controllable. Control points are defined for applications to interact with PICS. Decision tree based automatic performance analysis is implemented to significantly reduce the search space of multiple configurations. Parallel evaluation and sampling techniques are exploited to reduce the overhead of the system and to improve its scalability. In addition, the result of automatic performance analysis can be visualized to help developers manually tune their applications. The utility of PICS is demonstrated with several benchmarks and real- world applications

pH-sensitive polymeric micelles triggered drug release for extracellular and intracellular drug targeting delivery

AbstractMost of the conventional chemotherapeutic agents used for cancer chemotherapy suffer from multidrug resistance of tumor cells and poor antitumor efficacy. Based on physiological differences between the normal tissue and the tumor tissue, one effective approach to improve the efficacy of cancer chemotherapy is to develop pH-sensitive polymeric micellar delivery systems. The copolymers with reversible protonation–deprotonation core units or acid-liable bonds between the therapeutic agents and the micelle-forming copolymers can be used to form pH-sensitive polymeric micelles for extracellular and intracellular drug smart release. These systems can be triggered to release drug in response to the slightly acidic extracellular fluids of tumor tissue after accumulation in tumor tissues via the enhanced permeability and retention effect, or they can be triggered to release drug in endosomes or lysosomes by pH-controlled micelle hydrolysis or dissociation after uptake by cells via the endocytic pathway. The pH-sensitive micelles have been proved the specific tumor cell targeting, enhanced cellular internalization, rapid drug release, and multidrug resistance reversal. The multifunctional polymeric micelles combining extracellular pH-sensitivity with receptor-mediated active targeting strategies are of great interest for enhanced tumor targeting. The micelles with receptor-mediated and intracellular pH targeting functions are internalized via receptor-mediated endocytosis followed by endosomal-pH triggered drug release inside the cells, which reverses multidrug resistance. The pH sensitivity strategy of the polymeric micelles facilitates the specific drug delivery with reduced systemic side effects and improved chemotherapeutical efficacy, and is a novel promising platform for tumor-targeting drug delivery

IJTC2011-61050 MODELING OF EDDY CURRENT LOSS FOR MAGNETIC THRUST BEARINGS

ABSTRACT In this paper, an analytical model for calculating eddy current loss in magnetic thrust bearings (MTBs) is presented. The surface magnetic field intensity, considering the skin effect of eddy current, is varying with the frequency and can be calculated by effective reluctance method. The magnetic field distribution and eddy current loss can be obtained from it. Finally, the validity of the model is verified by the finite element method (FEM) simulation and experimental results. INTRODUCTION With contact-free rotors, active magnetic bearings (AMBs) usually have much lower losses than rolling bearings or oil bearing

Researches of Bypass Flows from Cold Plenum to Hot Plenum in HTR-PM by the Flow Network Method

ABSTRACT Many graphite blocks in the core of the HTR-PM serve as the construction material, the neutron reflector and the flow paths of the helium. A small part of helium gas may flow in widely distributed gaps among graphite blocks and enter the hot plenum at low temperature. In our previous paper, a simple flow network combined with CFD simulations of complex flow paths was established to analyze the bypass flow in HTR-PM. In the present paper, the flow network was detailed by assigning more inner nodes and links in the pebble bed. In all kinds of bypass flow paths, only the bypass flow from cold plenum to hot plenum (P-P) was considered. Horizontal flow between the core and the P-P bypass flow path was also added into the flow network in various heights from the top to the bottom. The existence of the horizontal flow enhanced the helium exchange between the core and the bypass flow to different extent in different position, and finally changed the P-P bypass flow ratio. Moreover, gaps in larger sizes had more significant effects on the P-P bypass flows

Solving k

Coverage problem is a critical issue in wireless sensor networks for security applications. The k-barrier coverage is an effective measure to ensure robustness. In this paper, we formulate the k-barrier coverage problem as a constrained optimization problem and introduce the energy constraint of sensor node to prolong the lifetime of the k-barrier coverage. A novel hybrid particle swarm optimization and gravitational search algorithm (PGSA) is proposed to solve this problem. The proposed PGSA adopts a k-barrier coverage generation strategy based on probability and integrates the exploitation ability in particle swarm optimization to update the velocity and enhance the global search capability and introduce the boundary mutation strategy of an agent to increase the population diversity and search accuracy. Extensive simulations are conducted to demonstrate the effectiveness of our proposed algorithm

The role of the neutrophil Fcγ receptor I (CD64) index in diagnosing spontaneous bacterial peritonitis in cirrhotic patients

SummaryObjectiveTo investigate the role of the neutrophil Fcγ receptor I (CD64) index in the diagnosis of spontaneous bacterial peritonitis (SBP) in cirrhotic patients.MethodsA total of 123 cirrhotic patients with ascites who fulfilled the inclusion criteria were enrolled in this study. Ascites and blood samples were collected; the polymorphonuclear neutrophil (PMN) count, bacterial culture, and related laboratory tests were performed. The CD64 index was determined for each sample using flow cytometry.ResultsThe neutrophil CD64 index results were significantly higher in cirrhotic patients with SBP than in those without SBP (p<0.001). There was a positive correlation between the neutrophil CD64 index and the PMN count in ascites. In the receiver operating characteristic curve (ROC) analysis, the area under the curve (AUC) was 0.894 (95% confidence interval 0.823–0.964, p<0.001). The optimal cut-off value for the neutrophil CD64 index was 2.02. The sensitivity and specificity of the neutrophil CD64 index for cirrhotic patients with SBP were 80.49% and 93.90%, respectively. The elevated neutrophil CD64 index was down-regulated by antibiotic therapy (p=0.002).ConclusionsThe neutrophil CD64 index could be used as a sensitive and specific indicator for the diagnosis of SBP in cirrhotic patients with ascites and is also modulated by antibiotic therapy

Perancangan Planogram Berdasarkan Merchandise Hierarchy Dan Category Management Di Ritel X

Penelitian dilakukan di Ritel X yang menjual produk-produk tekstil garmen seperti kemeja batik, blus batik, daster, baju anak laki-laki, baju anak perempuan dan sarung serta produk tekstil rumah tangga seperti sprei, selimut dan bed cover. Berdasarkan observasi yang dilakukan, produk-produk di Ritel X tidak tertata dengan baik dan belum melakukan perancangan tampilan produk yang mengakibatkan sulitnya menemukan produk-produk yang diinginkan konsumen. Peneliti akan membuat rancangan planogram berdasarkan category management dan merchandise hierarchy dari produk-produk yang ada di Ritel X. Pembuatan kategori produk dalam category management digunakan untuk mengetahui keseluruhan stock keeping unit dari produk-produk di Ritel X yang harus dirancang dalam planogram. Penetapan merchandise hierarchy dilakukan dengan cara melakukan wawancara secara langsung dengan para konsumen di Ritel X. Selain category management dan merchandise hierarchy dalam merancang planogram juga mempertimbangkan margin profit produk-produk. Hasil perancangan planogram diharapkan akan memberi dasar dalam menata tampilan produk di Ritel X agar lebih menarik minat kosumen dan meningkatkan profit penjualan

Enabling and scaling biomolecular simulations of 100 million atoms on petascale machines with a multicore-optimized message-driven runtime

A 100-million-atom biomolecular simulation with NAMD is one of the three benchmarks for the NSF-funded sustainable petascale machine. Simulating this large molecular system on a petascale machine presents great challenges, including handling I/O, large memory footprint and getting good strong-scaling results. In this paper, we present parallel I/O techniques to enable the simula-tion. A new SMP model is designed to efficiently utilize ubiquitous wide multicore clusters by extending the CHARM++ asynchronous message-driven runtime. We exploit node-aware techniques to op-timize both the application and the underlying SMP runtime. Hi-erarchical load balancing is further exploited to scale NAMD to the full Jaguar PF Cray XT5 (224,076 cores) at Oak Ridge Na-tional Laboratory, both with and without PME full electrostatics, achieving 93 % parallel efficiency (vs 6720 cores) at 9 ms per step for a simple cutoff calculation. Excellent scaling is also obtained on 65,536 cores of the Intrepid Blue Gene/P at Argonne National Laboratory. 1