Breathing motion is a significant source of error in radiotherapy treatment planning for the thorax and upper abdomen. Accounting for breathing motion has a profound effect on the size of conformal radiation portals employed in these sites. Breathing motion also causes artifacts and distortions in treatment planning computed tomography (CT) scans acquired during free breathing and also causes a breakdown of the assumption of the superposition of radiation portals in intensity-modulated radiation therapy, possibly leading to significant dose delivery errors. Proposed voluntary and involuntary breath-hold techniques have the potential for reducing or eliminating the effects of breathing motion, however, they are limited in practice, by the fact that many lung cancer patients cannot tolerate holding their breath. We present an alternative solution to accounting for breathing motion in radiotherapy treatment planning, where multislice CT scans are collected simultaneously with digital spirometry over many free breathing cycles to create a four-dimensional (4-D) image set, where tidal lung volume is the additional dimension. An analysis of this 4-D data leads to methods for digital-spirometry, based elimination or accounting of breathing motion artifacts in radiotherapy treatment planning for free breathing patients. The 4-D image set is generated by sorting free-breathing multislice CT scans according to user-defined tidal-volume bins. A multislice CT scanner is operated in the ciné mode, acquiring 15 scans per couch position, while the patient undergoes simultaneous digital-spirometry measurements. The spirometry is used to retrospectively sort the CT scans by their correlated tidal lung volume within the patient's normal breathing cycle. This method has been prototyped using data from three lung cancer patients. The actual tidal lung volumes agreed with the specified bin volumes within standard deviations ranging between 22 and 33 cm3. An analysis of sagittal and coronal images demonstrated relatively small (<1 cm) motion artifacts along the diaphragm, even for tidal volumes where the rate of breathing motion is greatest. While still under development, this technology has the potential for revolutionizing the radiotherapy treatment planning for the thorax and upper abdomen.

The behavior of colloidal silicon dioxide in a composition with a styrene/butyl acrylate oligomer grafted onto a thermoplastic polyamide adhesive to obtain a branched binder structure with penetration of branches into a capillary-pore system of a reinforcing fiber component is studied. The modifications of disaggregation of SiO 2 using ultrasonic treatment and mechanical activation with the impact of high shear stresses, ultrasound, and cavitation are compared. The methods of dynamic light scattering, IR spectroscopy, thermal analysis, and the textile material science are used in experiments to evaluate the elastic-deformation characteristics of fused packets. The set of complementary results confirms that the combined mechanical activation of an aqueous dispersion of oligoacrylate and silica causes destruction of silica nanospheres and the formation of a hybrid oligolymer-inorganic adduct. In contrast to the short-term effects of ultrasonic dispersion of SiO 2 , consolidated mechanical activation of components solves the problems of preventing aggregation of nanoparticles and providing a uniform distribution of the reinforcing filler in the composite. The efficiency of using the method for regulating the characteristics of the forming units and parts of sewing products has been shown. By selecting oligoacrylate, the separation of the stages of preliminary bonding of the material packets specific to sewing production using a thermoplastic adhesive, the design of a form of a finished product, and its fixing during wet-heat treatment is taken into account. The preparation of a hybrid adduct of mechanical activation provides an optimal ratio of the particle size for the efficient distribution of fractions in interfacial, interfiber, and intrafiber spaces of the textile web. The shift of the peaks of the phase transitions and chemical transformations in a system with nanodispersed SiO 2 controlled on the DSC thermograms is consistent with the temperature conditions of successive stages of the engineering process. The possibilities of a controlled change in the characteristics of the forming composite materials and a decrease in the material consumption of sewing products due to grafting modified oligoacrylate with a variable content of silicon dioxide are demonstrated.

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The article formulates an algorithmic approach to the binarization method and shows the effectiveness of its implementation in relation to the analytical study on the surface density of a nonwoven structure, used as a reinforcing base of a composite materialaccording to the digital image of its surface. This method is considered to be the basis for determining the influence of external factors on the verification parameters of the model output of the average density indicatorsin the structure of the nonwoven material and predicting the structural properties of the composite material obtained on its basis.

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