Ultrasound findings in subcutaneous plantar vein thrombosis: retrospective analysis of seven patients

Background Several disorders may result in forefoot pain. An uncommon cause of forefoot pain is subcutaneous plantar veins thrombosis (SCPVT) involving veins superficial to the plantar fascia. Purpose To describe the ultrasound (US) appearance of SCPVT, which has been described only once in the radiological literature. Material and Methods We performed a retrospective search of our PACS system from 2016 to 2020 to collect all cases of US-diagnosed SCPVT. We collected data on seven patients. Two radiologists analyzed the US images retrieved. All US examinations were performed with a multifrequency linear probe (frequencies in the range of 5–17 MHz). Results A localized plantar nodule was palpable in 86% of patients. The subcutaneous thrombosed vein appeared in all patients as a round or ovoid nodule located in the subcutaneous tissues that corresponded in four patients (4/5, 80%) to the painful palpable nodule. The size was in the range of 4–7 mm (mean = 5.4 mm). The thrombosed vein presented a connection with adjacent patent veins, appeared enlarged, and almost filled with hypo-isoechoic material, and in two patients (2/7, 29%), a thin peripheral fluid component surrounding the thrombus was detectable. Continuous scanning demonstrated slow blood movements inside the peripheral component due to blood circulation. Failure to compress the lumen of the thrombosed vein during the real-time US was evident in all patients. Conclusion SCPVT is a rare or underreported condition. Sonologists must know the US appearance of SCPVT to exclude other conditions and avoid unnecessary invasive studies.

Structural Strength of Cemented Carbides

The concept “structural strength of tool materials” got further development. The refusals of cemented carbide cutting plates, when heavy machining were analyzed. It was shown that 70…80% of refusals are the microchipping of cutting edges, tool cutting part chipping, cutting plate macrofracture. To assess cutting plate total carrying capacity and the influence of different methods of cemented carbides modification, bending tests were held. Local fracture resistance and damageability of cutting edge were assessed under its continuous scanning.

Numerical Simulation and Microstructure and Properties of 45 Steel by Scanning Electron Beam Bevel Polishing

In order to obtain metal products with good surface quality, it is necessary to develop an efficient bevel polishing method. Therefore, this article Uses continuous scanning electron beam polishing. The surface of the material undergoes rapid melting and solidification and generates a dynamic temperature field. The polishing treatment improves the microstructure of the surface layer of the quenched and tempered 45 steel, and significantly increases the microhardness of the surface layer. The hardness after treatment can reach up to 747.6Hv, which is about 2.4 times higher than the matrix; the structure after hardening is transformed from the mixed phase of coarse acicular martensite and lath martensite to hidden acicular martensite and retained austenite a mixed phase thereof. In addition, after bevels with different inclination angles are subjected to electron beam surface polishing modification treatments with different scanning speeds, under the same parameters, as the inclination angle increases, the hardness value at the same position decreases.

The microstructure and properties of Mo alloying layer after surface alloying treatment induced by continuous scanning electron beam process

Surface alloying by scanning electron beams can improve the microstructure and mechanical properties of steel. In this study. Four electron energy densities were selected during the alloying process: E1 = 1.5J/cm2, E2 = 2.9J/cm2, E3 = 4.5J/cm2 and E4 = 5.9J/cm2. The obtained results show that the sample surface is composed of alloying zone and heat-affected zone. The microstructure of the alloy zone is concealed acicular martensite and molybdenum carbide particles. The microhardness of this area is 1250HV. The sample treated with an energy density of 5.9J/cm2 has the least amount of wear. After alloying treatment, the microhardness and wear amount of the scanned samples are significantly improved.

Scan Mirror Assembly for the Multispectral Scanning Polarimeter of Aerosol-UA Space Mission

In this paper, the scan mirror assembly for the space experiment Aerosol-UA scanning polarimeter (ScanPol) is described. The aim of the Ukrainian space mission Aerosol-UA is to create a database of the optical characteristics of aerosol and cloud particles in the Earth’s atmosphere over a long period of time. The optical characteristics of aerosol and cloud particles are derived from multiangular measurements. Multiangular scanning in ScanPol is provided by scan mirror assembly, which contains a reactive torque compensator electric motor and two scan mirrors, mounted on the shaft of the motor. The control system of the scan mirror assembly enables continuous scanning with a constant speed of the space under investigation. This control system tolerates movements of the orbiting satellite and preserves invariability of its spatial position. The polarimeter ScanPol is designed to acquire spatial, temporal, and spectral-polarimetric measurements simultaneously to minimize instrumental effects and “false” polarizations due to scene movement. Instrumental polarization, introduced by the mirrors of scan assembly, is minimized through the polarization compensated two-mirror scheme which contains two mirrors with orthogonal planes of incidence. In this paper, the polarimetric model of the polarization compensated two scan mirrors is considered. Theoretical calculations are given that substantiate the maximum allowable error of the relative angular position of the mirrors is 15 arcmin (0.25°), and the method of adjustment and control of the angular position of the mirrors is proposed. The polarization properties of mirrors are modelled in the spectral range of 370–1680 nm for bulk oxide-free aluminum. It is obtained that the maximum instrumental polarization of the unadjusted mirror system should be observed at 865 nm, and thus, the polarization characteristics of the scanning system at a given wavelength could be considered as representative for ScanPol in general. The key steps for assembling the unit are illustrated.