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1.
Two proprietary biocides were compounded and extruded at three concentrations, respectively, into high density polyethylene-maple wood flour lumber (HDPE-MWL) and evaluated for their efficacy to control fungal colonization and discoloration using the ASTM Standard G 21-96. Although the silver biocide used in this study did not control fungal colonization and discoloration of HDPE-MWL, statistically significant difference was observed between the highest silver biocide concentration and those of the two lower silver biocide concentrations. The latter exhibited no significant difference with the controls. In contrast, the three levels of zinc biocides showed significant difference from each other with respect to their efficacy against fungal colonization and discoloration of HDPE-MWL. Overall, only the zinc biocide was efficacious against fungal colonization and discoloration. The biocide containing zinc as an active biocidal agent was most efficacious at 1% (by weight) concentration. 相似文献
2.
Xiao-Ying Wang Jonathan M. Garibaldi Benjamin Bird Michael W. George 《Applied Intelligence》2007,27(3):237-248
Recently Fourier Transform Infrared (FTIR) spectroscopic imaging has been used as a tool to detect the changes in cellular
composition that may reflect the onset of a disease. This approach has been investigated as a mean of monitoring the change
of the biochemical composition of cells and providing a diagnostic tool for various human cancers and other diseases. The
discrimination between different types of tissue based upon spectroscopic data is often achieved using various multivariate
clustering techniques. However, the number of clusters is a common unknown feature for the clustering methods, such as hierarchical
cluster analysis, k-means and fuzzy c-means. In this study, we apply a FCM based clustering algorithm to obtain the best number
of clusters as given by the minimum validity index value. This often results in an excessive number of clusters being created
due to the complexity of this biochemical system. A novel method to automatically merge clusters was developed to try to address
this problem. Three lymph node tissue sections were examined to evaluate our new method. These results showed that this approach
can merge the clusters which have similar biochemistry. Consequently, the overall algorithm automatically identifies clusters
that accurately match the main tissue types that are independently determined by the clinician. 相似文献
3.
4.
BACKGROUND: The effects of beta 2 adrenergic agonists on chemoreceptors remain controversial. This study was designed to examine whether fenoterol, a beta 2 adrenergic agonist, increases the ventilatory responses to hypercapnia (HCVR) and hypoxia (HVR) in normal subjects. METHODS: HCVR was tested with a rebreathing method and HVR was examined with a progressive isocapnic hypoxic method in 11 normal subjects. Both HCVR and HVR were assessed by the slope of occlusion pressure (P0.1) or ventilation (VE) plotted against end tidal carbon dioxide pressure and arterial oxygen saturation, respectively. Respiratory muscle strength, spirometric values and lung volume were measured. After a single oral administration of 5 mg fenoterol or placebo HCVR and HVR were evaluated. RESULTS: Fenoterol treatment did not change the specific airway conductance or forced expiratory volume in one second. Respiratory muscle strength did not change. Fenoterol increased the slope of the HCVR of both P0.1 (from 0.251 (0.116) to 0.386 (0.206) kPa/kPa, average increase 71%) and VE (from 10.7 (3.4) to 15.1 (4.2) l/min/kPa, average increase 52%), and shifted the response curves to higher values. For the HVR fenoterol increased the slopes of both P0.1 and VE (from -4.06 (2.00) x 10(-3) to -7.99 (4.29) x 10(-3) kPa/%, an average increase of 83%, and from -0.221 (0.070) to -0.313 (0.112) l/min/%, a 44.5% increase, respectively), and shifted the response curves to higher values. CONCLUSION: Acute administration of fenoterol increases the ventilatory responses to both hypercapnia and hypoxia in normal subjects. 相似文献
5.
MG Fehlings T Errico P Cooper V Benjamin T DiBartolo 《Canadian Metallurgical Quarterly》1993,32(2):198-207; discussion 207-8
Although occipitocervical fusion is frequently used for instability of the upper cervical spine and the occipitocervical articulation, most currently used techniques have one or more of the following disadvantages: the necessity for sublaminar wires, the use of occipital screws, a fixed angle of instrumentation, or the necessity for routine postoperative halo immobilization. Moreover, many reported techniques are associated with a high rate of nonunion or instrumentation failure. We present our experience with a technically simple method of obtaining rigid occipitocervical arthrodesis using a 5-mm malleable rod that is fixed to the skull by a pair of wires passed through four suboccipital burr holes. Segmental spinal fixation is achieved with Wisconsin interspinous wires and is occasionally supplemented with sublaminar wires. Supplemental autogenous bone graft is used in all cases. A cervical collar is routinely used for postoperative immobilization. The results of treatment were retrospectively reviewed in 16 patients with an average age of 49.4 years (range, 9-69). Mean follow-up was 24 months (range, 12-36 mo). The indication for fusion was instability of the occiput-C1-C2 complex as a result of Chiari malformation, rheumatoid disease, skull base tumor resection, basilar invagination, ankylosing spondylitis, Down's syndrome, cervical laminectomy, and trauma. The average number of levels fused was 5.4 (range, O-C3 to O-T3). Successful occipitocervical arthrodesis was achieved in all but one of the surviving patients. The single patient with a pseudarthrosis was successfully managed with supplemental bone grafting and halo immobilization. There were two deaths from medical complications in chronically ill patients. Other complications included one postoperative instrumentation loosening, one myocardial infarction, and one superficial occipital decubitus. In conclusion, rodding and segmental interspinous wiring is an effective, technically simple method of obtaining rigid occipitocervical fixation, which obviates the need for bulky orthoses. 相似文献
6.
U. Prakash K. Muraleedharan R. A. Buckley H. Jones P. A. Shenton 《Journal of Materials Science》1996,31(6):1569-1573
Substitutions (0–16 at%) of titanium for iron in Fe3Al-based alloys rapidly solidified by chill-block melt-spinning stabilize the D03 and B2 ordered structures. Rapid solidification results in total suppression of D03 order in binary alloys, whereas alloys containing titanium have D03 structure. D03 and B2 antiphase domain size, lattice parameter and hardness increase with increasing titanium content of the alloy. The deformation mode changes from single (unit) bcc dislocation in binary alloys to two-fold superdislocation configuration in D03Fe3Al-Ti alloys. Mechanical antiphase boundaries are generated by the movement of these imperfect configurations. All the alloys exhibited cleavage tensile failure. The mechanical properties are correlated with the observed structural changes. 相似文献
7.
Chen L.R. Benjamin S.D. Smith P.W.E. Sipe J.E. 《Quantum Electronics, IEEE Journal of》1998,34(11):2117-2129
We discuss theoretical and experimental studies on the propagation of ultrashort pulses through fiber Bragg gratings. We also consider several applications in optical communications to be found by combining ultrashort pulses and fiber Bragg gratings: a multiwavelength source for wavelength-division-multiplexed systems and a means for implementing optical code-division multiple access 相似文献
8.
Low-temperature-grown GaAs (LT-GaAs) is a promising material for all-optical switching devices due to its outstanding optical characteristics. In this paper, we outline a simplified model we have developed to describe the dynamics of the carriers in this material. We also report the results of a series of measurements that we have performed to characterize the optical properties of the material. Specifically, we present the first measurements of the two-photon absorption coefficient and the refractive index changes as a function of the growth and annealing temperatures in LT-GaAs. Finally, we show how our model can be used to optimize the material for applications in all-optical switching 相似文献
9.
The object of this paper is to demonstrate the usefulness of the transalkylation reaction for determining chemical structural features of products derived from coal. For example, the method is applied to derivatized coals, coals modified by thermolysis, and materials physically or chemically separated from coals. Data are presented for the pyridine soluble and insoluble parts of two coals, an O-methylated coal, a Birch reduced coal, a solvent refined coal, and a coke. Similarities and differences in chemical make-up of these materials are discussed. 相似文献
10.
The large-deformation three-dimensional glass-rubber constitutive model for isotropic, amorphous, linear polymers near the glass transition, previously proposed, has been extended to include a spectrum of network relaxations. In addition, an experimental programme of uniaxial tension and compression tests was carried out on high molecular weight cast sheets of poly(methyl methacrylate) (PMMA), with varying strain-rate and temperature across the range from 114 to 190 °C, encompassing the thermoforming range of practical importance. The extended model was found to fit successfully the data for PMMA, provided a doublet network relaxation spectrum was employed. The original model, with only a single network relaxation, was found to be grossly inadequate when there was significant network relaxation by entanglement slippage. Parameters of the model for PMMA, obtained by fitting to the new data, were compared with values obtained by other routes. 相似文献