Wang, W.
Sokolov, D. A.
Huxley, A. D.
Kamenev, K. V.
Inelastic neutron scattering measurements typically require two orders of magnitude longer data collection times and larger sample sizes than neutron diffraction studies. Inelastic neutron scattering measurements on pressurised samples are particularly challenging since standard high-pressure apparatus restricts sample volume, attenuates the incident and scattered beams, and contributes background scattering. Here, we present the design of a large volume two-layered piston-cylinder pressure cell with optimised transmission for inelastic neutron scattering experiments. The design and the materials selected for the construction of the cell enable its safe use to a pressure of 1.8 GPa with a sample volume in excess of 400 mm(3). The design of the piston seal eliminates the need for a sample container, thus providing a larger sample volume and reduced absorption. The integrated electrical plug with a manganin pressure gauge offers an accurate measurement of pressure over the whole range of operational temperatures. The performance of the cell is demonstrated by an inelastic neutron scattering study of UGe(2). (C) 2011 American Institute of Physics. [doi:10.1063/1.3608112]
Using the finite-difference time-domain (FDTD) method, we make a dosimetry study on the specific absorption rate (SAR) in cells exposed to 1800 MHz standing waves produced by the transverse electromagnetic (TEM) chamber. Two types of cultured cells are used, namely, the cell layer and the cell suspension. Based on the calculated SAR distribution, the exposure is characterized by the SAR intensity and homogeneity. We consider different exposure arrangements, as the combination of the maximum fields of the standing wave and the polarizations of the Petri dish. The maximum E field and maximum H field are used in turn in the exposure volume, where the Petri dish is polarized in the E, H, k and k directions, respectively. The best exposure arrangements are determined by measuring the intensity and homogeneity of the SAR distribution, in cells. For a tight control of the thermal environment, the temperature rise in the cell culture induced by the exposure is calculated by using the finite-difference formulation of the bio-hear: conduction equation. The linear relation between the maximum temperature rise and the absorbed power is determined to quantify the exposure power for the temperature control.
Wang, W.
Kravchenko, A. N.
Smucker, A. J. M.
Liang, W.
Rivers, M. L.
Intra-aggregate pores play an important role in controlling soil processes on a micro-scale. Differences in parent materials, pedogenic processes, land use, and management practices can have a substantial effect on their characteristics. The goal of this study is to examine intra-aggregate pore characteristics using X-ray computed microtomography (mu CT) images in soils of two contrasting parent materials and of contrasting land use and management. In addition, to quantify pore characteristics in aggregate exterior and interior layers we have developed an approach for aggregate boundary delineation in mu CT images. Soil aggregates from a Hapludalf under Long Term Ecological Research conventional tillage treatment (LTER-CT) and native succession vegetation treatment (LTER-NS) in southwest Michigan, and from an Ustochrept under native succession vegetation and bare soil in northeast China were used. The LTER-CT aggregates had significantly greater macro-porosity (>14.6 mu m in diameter) than those of LTER-NS. The LTER-NS aggregates had more large pores (>97.5 mu m) and more small pores (<15 mu m) than LTER-CT aggregates, while more medium size pores (37.5-97.5 mu m) were found in LTER-CT aggregates. Greater abundance of medium sized pores in LTER-CT aggregates could be the cause of their reported lower stability and higher macro-aggregate turnover rate. The differences in pore size distributions between LTER-CT and LTER-NS were more pronounced in the aggregate interiors, as compared to the exterior layers. In aggregates from both studied soils large pores tended to prevail in the aggregate interiors while medium size pores (37.5-97.5 mu m) were more abundant in the aggregate exteriors.
Wang, W.
Matsubara, T.
Takao, Y.
Yasuda, K.
Hayashi, R.
In this paper, short time co-cure of CFRP–steel hybrid laminates using hot pressing and the effects of curing conditions on the interlaminar shear strength (ILSS) of the hybrid laminates are investigated experimentally to explore a cost-effective co-cure process of CFRP–steel hybrid laminates for automotive applications. A new kind of CFRP prepreg which can be cured in several minutes is used. Various curing conditions including those with and without surface treatment of metal layer, those with and without an adhesive film, three kinds of adhesive films, and three curing pressures are investigated. Short beam three-point bending tests for the hybrid laminates are conducted to evaluate the ILSS of the hybrid laminates. A cost-effective co-cure process is proposed based on the experimental results.
Wang, W.
Baladandayuthapani, V.
Morris, J. S.
Broom, B. M.
Manyam, G.
Do, K.-A.
Motivation: Analyzing data from multi-platform genomics experiments combined with patients' clinical outcomes helps us understand the complex biological processes that characterize a disease, as well as how these processes relate to the development of the disease. Current data integration approaches are limited in that they do not consider the fundamental biological relationships that exist among the data obtained from different platforms. Statistical Model: We propose an integrative Bayesian analysis of genomics data (iBAG) framework for identifying important genes/biomarkers that are associated with clinical outcome. This framework uses hierarchical modeling to combine the data obtained from multiple platforms into one model. Results: We assess the performance of our methods using several synthetic and real examples. Simulations show our integrative methods to have higher power to detect disease-related genes than non-integrative methods. Using the Cancer Genome Atlas glioblastoma dataset, we apply the iBAG model to integrate gene expression and methylation data to study their associations with patient survival. Our proposed method discovers multiple methylation-regulated genes that are related to patient survival, most of which have important biological functions in other diseases but have not been previously studied in glioblastoma.
A novel smart sensing unit is developed in this paper for vibration measurement and machinery condition monitoring. The microprocessor-based smart sensor can collect 2-D vibrations and conduct signal analysis. When mounted in proximity of a bearing housing (a general case), it can conduct online fault detection in shafts and bearings. A correlation spectrum method is proposed as a digital encoder to recognize shaft rotation speed. A wavelet energy spectrum technique is adopted for bearing fault detection. A novel strategy is suggested to extract representative features and enhance feature characteristics by integrating the resulting wavelet energy functions over different frequency bands. The effectiveness of the developed smart sensor and the related fault detection techniques is verified by experimental tests corresponding to different bearing conditions. Test results show that the developed smart sensing unit is an effective measurement and condition monitoring tool; the wavelet energy spectrum technique is a robust bearing fault detection method, especially for nonstationary feature extraction and analysis.
Existing workload algorithms based on the Multiple Resources Theory (MRT) provide an effective approach for diagnosing operator overload caused by interference among concurrent tasks, however, their ability to handle overload in single task conditions is limited. We argue a time-based algorithm, developed on the Information Processing (IP) model of workload (Hendy, Liao, & Milgram, 1997), provides a viable solution to address this limitation. In this study, we proposed a new algorithmic implementation of the IP model in the context of task network modeling. The new algorithm was implemented in a JAVA program and tested on an existing model of a Bakan vigilance task. The results obtained from the new algorithm demonstrated the feasibility of this solution. By integrating resource-based and time-based algorithms, analysts will be able to diagnose more accurately system performance breakdowns caused by operator overload.