Research on the Optimal Allocation of Tolerances of CNC Machine Tools Based on Small Deformation of Grinding Wheel

In order to solve the problem of precision optimization design of CNC machine tools, this paper proposes an optimized allocation method of machine tool tolerance parameters that takes into account the slight deformation of the machine tool. First, establish a tolerance-based geometric error prediction model, and establish a spatial motion error model based on the theory of multi-body systems(MBS); Homogeneously, perform finite element analysis(FEA) on the CNC internal cylindrical compound grinding machine to obtain the slight deformation of the machine tool, and apply the result to the optimal tolerance allocation In the constraint conditions, the final optimal allocation plan is obtained; Finally, the genetic algorithm is used to simulate and analyze the plan, and the optimal tolerance allocation result is obtained. The result shows that most of the tolerance parameters have been relaxed, which means that the machine tool’s manufacturing cost. Through experiments, it is verified that the optimized machine tool machining accuracy pass rates are 98.5%, 98.25%, and 97.85%, respectively. Therefore, the optimal allocation method of tolerances that considers small deformations proposed in this paper is effective.

Change of Microstructure and Hardness of Duo-Casted Al3003/Al4004 Clad Material during Extrusion Process

This study was carried out to observe and measure the microstructure, distance between dendrite arms, aspect ratio, and Knoop hardness change of extruded material formed by the hydro co-extrusion of Al3003/Al4004 clad material manufactured by the duo-casting method. The specimen of duo-casted Al3003/Al4004 clad materials was circle shaped; it was composed of Al3003 (outside) and Al4004 (inside) materials. The manufacturing conditions of the hydro co-extruded specimen were 423 K temperature and 6.5 ratio of extrusion. At the interface of the duo-casted Al3003/Al4004 clad material, a non-junction at the interface and non-metallic inclusions of Si- and Mn-based oxides were observed. Al3003 exhibits equiaxed crystals; Al4004 has a casted structure with dendrites before extrusion, showed slight deformation during extrusion, and then finally exhibited completely deformed structures after extrusion. In the cast material, the distance between dendrite arms increased, and the aspect ratio of dendrites tended to decrease from the surface to the center. However, in the case of the extruded material, neither Al3003 nor Al4004 changed significantly from the surface to the inside. As extrusion progressed, the Knoop hardness value at the interface of Al3003/Al4004 increased rapidly compared with those of Al3003 and Al4004 matrixes.

Understanding the Performance of a Novel Direct Compression Excipient Comprising Roller Compacted Chitin

Chitin has been investigated in the context of finding new excipients suitable for direct compression, when subjected to roller compaction. Ball milling was concurrently carried out to compare effects from different energy or stress-inducing techniques. Samples of chitin powders (raw, processed, dried and humidified) were compared for variations in morphology, X-ray diffraction patterns, densities, FT-IR, flowability, compressibility and compactibility. Results confirmed the suitability of roller compaction to convert the fluffy powder of raw chitin to a bulky material with improved flow. X-ray powder diffraction studies showed that, in contrast to the high decrease in crystallinity upon ball milling, roller compaction manifested a slight deformation in the crystal lattice. Moreover, the new excipient showed high resistance to compression, due to the high compactibility of the granules formed. This was correlated to the significant extent of plastic deformation compared to the raw and ball milled forms of chitin. On the other hand, drying and humidification of raw and processed materials presented no added value to the compressibility and compactibility of the directly compressed excipient. Finally, compacted chitin showed direct compression similarity with microcrystalline cellulose when formulated with metronidazole (200 mg) without affecting the immediate drug release action of the drug.

Bi-continuous orthorhombic soft matter phase made of polycatenar molecules

A slight deformation of a double gyroid structure of a cubic Ia3̄d phase results in the formation of a phase with an orthorhombic Pcab symmetry. The phase seems to be an intermediate state towards a columnar phase made of helical pillars.

Large Chicory aphid (Uroleucon cichorii (Koch, 1855): Sterrnorhyncha: Aphididae) – Invasive Alien Aphid Species in the Fauna of Belarus

Uroleucon cichorii (Insecta: Hemipteroidea: Rhynchota: Sternorrhyncha: Aphididae) is an invasive alien species in the fauna of Belarus. In 1854 the species has been described by C. L. Koch from Germany. For the first time U. cichorii has been noted in Great Britain in 1876, in Estonia – 1894, in Romania – 1896, in Italy – 1900, in Belgium – 1901, in Crimea – 1903, in Latvia – 1924, in Poland –1930, in Netherlands – 1939, in Finland – 1941, in Ukraine – 1945, in France – 1948, in Sweden – 1949, in Norway – 1953, in Denmark – 1954, in Moldavia – 1955, in Austria – 1956, in Czech – 1958, in Hungary – 1959, in Bulgaria – 1960, in European Russia – 1962–1964, in Bosnia and Herzegovina – 1963, in Serbia – 1963, in Lithuania – 1963–1980, in Macedonia – 1964, in Switzerland – 1967, in Spain – 1971, in Sicily –1973, in Corsica – 1973, in Balearic Islands (Mallorca) – 1982, in Belarus – 1986 and Greece – after 1992. It is obvious that this chronological list describes a history of aphidological research rather than spreading of the invider across the European regions. As considered, the species has Mediterranean origin. Outside of Europe the species is known from Near East as well as Central Asia, Korea and North America. As host plants U. cichorii s.str. uses common chicory (Cichorium intibus L.) and related species of Cichorieae (Asteraceae). The species is known as a pest of common chicory (including leaf chicory) and endive. For the first time U. cichorii has been registered in 1986. At present the species is common for C. intibus growing on roadsides and in other ruderal biotopes. During 1986–2018 U. cichorii has been registered in the all regions of the Republic of Belarus. The map of geographic points of registrations is given. It is obvious that the invider’s expansion in the regions of Belarus is finished. The species is holocyclic and monoecious. Feeding on forage plants contributes to the loss of a significant amount of plastic substances, which leads to their dehydration and slow growth, and, as a result, a slight deformation of the stem. U. cichorii does not initiate the deformation of leaf blades and the premature dying off of the inflorescences, and also does not lead to the formation of galls. Perennial data show the appearance of fundatrices from overwintering eggs in the third decade of April – the first decade of May. Further a series of successive parthenogenetic generations and the growth of colonies occur. The winged females are recorded in July–August. The appearance of winged males and normal females occurs in September – the first decade of October. The eggs are deposited in the end of October. The largest peak in the number of U. cichorii registrations occurs in July–August.

Large Chicory aphid (Uroleucon cichorii (Koch, 1855): Sterrnorhyncha: Aphididae) – Invasive Alien Aphid Species in the Fauna of Belarus

Uroleucon cichorii (Insecta: Hemipteroidea: Rhynchota: Sternorrhyncha: Aphididae) is an invasive alien species in the fauna of Belarus. In 1854 the species has been described by C. L. Koch from Germany. For the first time U. cichorii has been noted in Great Britain in 1876, in Estonia – 1894, in Romania – 1896, in Italy – 1900, in Belgium – 1901, in Crimea – 1903, in Latvia – 1924, in Poland –1930, in Netherlands – 1939, in Finland – 1941, in Ukraine – 1945, in France – 1948, in Sweden – 1949, in Norway – 1953, in Denmark – 1954, in Moldavia – 1955, in Austria – 1956, in Czech – 1958, in Hungary – 1959, in Bulgaria – 1960, in European Russia – 1962–1964, in Bosnia and Herzegovina – 1963, in Serbia – 1963, in Lithuania – 1963–1980, in Macedonia – 1964, in Switzerland – 1967, in Spain – 1971, in Sicily –1973, in Corsica – 1973, in Balearic Islands (Mallorca) – 1982, in Belarus – 1986 and Greece – after 1992. It is obvious that this chronological list describes a history of aphidological research rather than spreading of the invider across the European regions. As considered, the species has Mediterranean origin. Outside of Europe the species is known from Near East as well as Central Asia, Korea and North America. As host plants U. cichorii s.str. uses common chicory (Cichorium intibus L.) and related species of Cichorieae (Asteraceae). The species is known as a pest of common chicory (including leaf chicory) and endive. For the first time U. cichorii has been registered in 1986. At present the species is common for C. intibus growing on roadsides and in other ruderal biotopes. During 1986–2018 U. cichorii has been registered in the all regions of the Republic of Belarus. The map of geographic points of registrations is given. It is obvious that the invider’s expansion in the regions of Belarus is finished. The species is holocyclic and monoecious. Feeding on forage plants contributes to the loss of a significant amount of plastic substances, which leads to their dehydration and slow growth, and, as a result, a slight deformation of the stem. U. cichorii does not initiate the deformation of leaf blades and the premature dying off of the inflorescences, and also does not lead to the formation of galls. Perennial data show the appearance of fundatrices from overwintering eggs in the third decade of April – the first decade of May. Further a series of successive parthenogenetic generations and the growth of colonies occur. The winged females are recorded in July–August. The appearance of winged males and normal females occurs in September – the first decade of October. The eggs are deposited in the end of October. The largest peak in the number of U. cichorii registrations occurs in July–August.

Experimental Assessment of the Depth of the Deformed Layer in the Roller Burnishing Process

This paper presents the methods of experimental determining the depth of the plastically deformed top layer in the roller burnishing process. Precise determination of the depth of the plastically deformed layer is difficult due to slight deformation at the boundary of the plastic and elastic zone, the lack of visible changes in the microstructure, and minimal changes in microhardness. The article shows the method of original measurement method that consists in determining the thickness of the deformed layer using rings. The method involves the profilographometric measurements of the disconnected rings (samples) which are flat-faced in the package on the mandrel. The rings material deforms plastically in the surface layer causing wrapping of the end face of the ring in the direction of the rolling tool movement. After dismantling the ring pack, measurements were made on the face of each ring along radial directions, and the thickness of the deformed layer was observed on the microscope. The method was verified by microhardness measurements in the cross-section and cross-section of the ring. The results of deformation depth measurements were verified by finite-element-based numerical simulation.

Pathogenicity Of Mycogone Perniciosa Isolates Collected On Polish Mushroom Farms

Mycogone perniciosa is the fungal pathogen causing the wet bubble of white button mushrooms (Agaricus bisporus). The main symptoms of disease are undifferentiated, irregular forms of mushroom tissue, cap spotting and development of amber liquid droplets on the distorted mushrooms. The aim of the research was to assess the pathogenicity of M. perniciosa isolates that were obtained from the infected sporophores. Six isolates from Polish mushroom farms as well reference strain of Hypomyces perniciosus CBS 322.52 were used in this study. The pathogenicity of isolates was assessed on the basis of severity of disease symptoms and crop reduction in the first flush. Mushroom crop was infected with different suspensions containing of M. perniciosa aleuriospores. Significant variability was shown between tested isolates. It was stated that the pathogenicity of isolates and concentration of conidia had a significant influence on the mushroom yield. The isolate of high pathogenicity caused significant yield losses, after inoculation with 1.3 × 104·m−2, whereas the isolate with fairly pathogenicity did not produce symptoms of wet bubble disease or caused slight deformation of single sporophores, even when the casing soil was inoculated with 1.3 × 106·m−2 spores.

Adsorption of Sulfur’s Atoms on the Outer Surface of Carbon Nanotubes

The article is about regularities of structure formation of carbon nanotubes (7,7) in their ground state in the process of the gradually increasing of the concentration of sulfur atoms. The fragment of nanotube is investigated within the framework of the density functional theory with the using of periodic boundary conditions. It contains 112 carbon atoms and n = 1 ÷ 9 sulfur atoms. It is shown that the most energetically favorable configurations of n = 1 ÷ 6 sulfur atoms can be considered as a configuration uncombined sulfur clusters Sn with the slight deformation by tube field. From n = 6, there is a tendency toward the formation of a ribbon structures with 2 sulfur atoms wide, it has a tendency in the moment of increasing n to be guided by transversely to the tube axis. In all considered cases the sulfur atoms are located at a distance from the surface of the tube more than 0.28 nm, it is excluded the possibility of the formation of the strong (covalent) chemical bonds with the carbon nanotube.