Factors responsible for the polypropylene consumption growth in the post-crisis period were analyzed, and the world’s largest polypropylene manufacturers and leading polypropylene-producing countries ...were listed. Preferential growth of polypropylene production in Asia and the Middle East and the specific features of development of the raw material base of polypropylene under the Russian market conditions were demonstrated. The key polypropylene consumption areas in North America, Europe, and the Russian Federation were identified as follows: films, packaging materials, components for automotive industry, plastic pipes, fibers and fibrous materials, sheets, plastic furniture, and construction elements.
The Nakagami distribution was proposed recently for modeling the echo from tissue. In vivo breast data collected from patients with lesions were studied using this Nakagami model. Chi-square tests ...showed that the Nakagami distribution is a better fit to the envelope than the Rayleigh distribution. Two parameters, m (effective number) and /spl alpha/ (effective cross section), associated with the Nakagami distribution were used for the classification of breast masses. Data from 52 patients with breast masses/lesions were used in the studies. Receiver operating characteristics were calculated for the classification methods based on these two parameters. The results indicate that these parameters of the Nakagami distribution may be useful in classification of the breast abnormalities. The Nakagami distribution may be a reasonable means to characterize the backscattered echo from breast tissues toward a goal of an automated scheme for separating benign and malignant breast masses.
Present-day rheological theory for the flow of dilute, concentrated, and highly concentrated filled polymeric solutions and its experimental basis are considered. The optimum type of fiber-forming ...polymer and solvent for preparation of spinning compositions is chosen. The advantages and disadvantages of various grades of activated carbon for the formation of filled fibrous sorption-active materials are noted. It was found that the nature of the activated carbon (the method of preparation, type of feedstock, porous structure, etc.) has a significant effect on the stability of the suspensions. The principal factors that determine the rheological characteristics of spinning compositions, such as the viscosity of the dispersion medium, the nature of the fillers, and the volume fraction and dispersibility of the solid phase, were studied. Their optimum values and their quantitative contribution to the change of viscosity were also established.
Various methods for modifying fibrous composite materials for application in respiratory protective devices are discussed. The main advantages and disadvantages of absorptive materials prepared by ...various methods for modifying composites are enumerated. The most effective activated carbons used in respiratory protective devices and samples of absorptive materials filled by them are compared by testing. The effects of the properties of the filler and the structure of the absorptive fibrous composite materials on its characteristics are studied.
Breast cancer diagnosis through ultrasound tissue characterization was studied using receiver operating characteristic (ROC) analysis of combinations of acoustic features, patient age, and ...radiological findings. A feature fusion method was devised that operates even if only partial diagnostic data are available. The ROC methodology uses ordinal dominance theory and bootstrap resampling to evaluate A/sub z/ and confidence intervals in simple as well as paired data analyses. The combined diagnostic feature had an A/sub z/ of 0.96 with a confidence interval of 0.93, 0.99 at a significance level of 0.05. The combined features show statistically significant improvement over prebiopsy radiological findings. These results indicate that ultrasound tissue characterization, in combination with patient record and clinical findings, may greatly reduce the need to perform biopsies of benign breast lesions.
We have studied the influence of the structural parameters of a composite nonwoven material (obtained by introducing a sorption-active filler with different particle size distributions into the ...interior and o the surface of a polyacrylonitrile fiber during aerodynamic spinning from a polymer solution) on its basic performance characteristics. We have established that obtaining filled nonwoven materials from thin fibers will allow us to appreciably improve the sorption and physicomechanical properties of fiber webs. We show that it is possible to control the structure of a composite nonwoven material by controlling the aerodynamic spinning parameters, allowing us to obtain materials with performance properties that are optimally suited for use in the finished products, including personal protective equipment, medicine, and the pharmaceutical industry
The influence of the activity of the filler and also structural factors of composite fibre material (CFM) on its physicochemical and physicomechanical properties was studied. The CFM was obtained by ...introducing sorption-active filler of different particle size into polymer fibre and onto the surface of the fibre in the process of aerodynamic spinning from polymer solution.
The K-distribution had been introduced as a valid model to represent the statistics of the envelope of the backscattered echo from phantom and tissue. This paper investigates the efficacy of the ...parameters of this statistical model; namely, the effective number and the effective cross-section, to characterize breast lesions as benign or malignant. Based on the normalized values of the effective number and the effective scattering cross-section, images containing benign and malignant masses were classified for a data set from 52 patients having breast masses/lesions. The receiver operating characteristic (ROC) curves were then obtained to test the classification based on these two parameters. The results indicate that the parameters of the K-distribution may be useful in classification of the breast lesions as benign and malignant.
Nonwoven material made of polypropylene with a 3-3.5 μm fibre diameter manufactured at the Synthetic Fibre Scientific-Research Institute (VNIISV) experimental plant can be used as the inner layer of ...long-acting protective-filtering clothing. Technology must be developed for manufacturing aerodynamically spun fibre materials (ASFM) with finer fibres (0.5-2.5 μm) by further modernizing of the equipment to ensure the higher sorption capacity of ASFM close to the initial capacity of activated carbon.
