Agaricus subrufescens growers have faced difficulties in standardizing and maintaining optimal production yield, even when they produce or acquire quality substrate, as cultivation success is also ...related to the quality of the casing layer and the production environment. The production of A. subrufescens was evaluated using different casing layers and methods for primordia induction. Three experiments were carried out: 1) to evaluate the effect of dolomitic limestone in the casing layer; 2) to evaluate the effect of different combinations of mineral and organic materials used as the casing layer; and 3) to evaluate the effect of temperature in primordia induction with two commercial strains. The results demonstrated that an increase in the limestone concentration in the casing resulted in a superior yield (16.7%). Casing layer combinations using organic substrate + sand (proportion 1:1, volume to volume) resulted in a greater yield (19.2%). Temperature did not affect primordia induction.
An experimental methodology for determining the product of the external friction coefficient and the lateral pressure coefficient depending on the compacting pressure is proposed. The results of ...powder materials testing show that the values of the product of the external friction coefficient and the lateral pressure coefficient have strong correlation with the compacting pressure in the pressure range of 30-350 MPa. The hypothesis about the external friction coefficient and the lateral pressure coefficient product constancy (when the compacting pressure changes) has not been experimentally confirmed; however, it can be implemented for some powder materials in a limited compacting pressure range.
To obtain long polymer double-layer products, it is proposed to use an extrusion head having a reinforced contact zone between materials. Numerical experiments were carried out to identify rational ...shapes and sizes of the reinforcing element (tooth). The dependences of the velocity inhomogeneity coefficient in the output section of the head on the relative height of the tooth and its angle are established.
A lo largo de los últimos años las excavaciones arqueológicas llevadas a cabo en el yacimiento de Revenga (Comunero de Revenga, Burgos) han permitido recuperar algunos materiales cerámicos de ...cronologías tardoantiguas y altomedievales. Dado su estado de conservación muy precario, el carácter utilitario de este tipo de producciones y las dificultades que aún hoy existen en el estudio de la cerámica común altomedieval, dichos materiales plantean algunos problemas interpretativos que hemos intentado resolver a partir de una caracterización petrográfica de los mismos. Los resultados obtenidos aportan nuevos datos muy significativos para el conocimiento de las comunidades del Alto Arlanza, permiten precisar las distintas fases de ocupación del asentamiento de Revenga y abren nuevas perspectivas para la investigación futura.
The article discusses the issues of recycling used plastic packaging materials and production waste. A description of the main operations for processing plastic waste in order to produce various ...materials and secondary technical products from them is given. A machine and hardware scheme of a production line for the production of granular polymer semi-finished products is proposed.
Introduction. Geographical location of natural resources is a determinant of localization of tourism. Based on the results of the research conducted, the article studies the theoretical and practical ...aspects of transformation of natural resources into a factor in production and consumption of a tourist product, as well as those of formation of directions for the flow of tourists.
Materials and Methods. Materials of surveys of potential tourists conducted by independent research firms, Russian and foreign scientific publications and expert assessments, as well as the results of research carried out by the author of the article were used as the information base of the study. To assess the role and place of natural resources in the production and consumption of a tourist product, content analysis, as well as structural and functional analysis were employed. Using the methods of logical interpretation, statistical data processing, tabular and graphical methods, a scheme of transformation of natural resources into a factor in production and consumption of a tourist product has been devised and the degree of consumer preference for a tourist destination has been identified.
Results. The study has identified problematic aspects of the use of natural resources in tourism, one of which is the underestimation of such resources as a basic factor in production and consumption of a tourist product, which negatively affects the level of economic feasibility of tourism development programs. The role of natural resources in formation of tourist needs and directions of the flow of tourists has been revealed. Conclusions have been drawn about the growing need for tourism with the predominance of the natural component of the tourist product and about the gradual formation of preconditions for local manifestations of overtourism and tourism phobia, in particular in the resorts in the South of Russia. The author has formulated proposals aimed at improving the economic feasibility of domestic tourism development programs.
Discussion and Conclusion. Availability of natural resources is the primary basic condition for production and consumption of a tourist product. Significant costs for their transformation into tourist goods increase the requirements for the level of reasonableness of managerial decisions. The research results can be applied in strategic and medium-term planning of the development of domestic tourism in Russian regions on the basis of their natural potential.
Possibilities for optimizing the design of self-cooled radiators were investigated. The SIMP method can be used for topologically optimizing the steady-state thermal conductivity of a flat plate with ...the Dirichlet condition on the lateral edge and uniform heat release throughout the volume. A radiator with optimal topology geometry was constructed using wire EDM cutting technology. The results of the heat removal efficiency comparison for topologically optimized radiators and conventional finned radiators are presented in the form of their temperature fields. Studies have demonstrated the high efficiency of a topologically optimized radiator design heat removal in comparison with finned ones. Recommendations for the practical application of the results obtained are formulated.
The process of interaction of a bronze insert placed in a lost foam mold with liquid steel filling this mold and thus producing a bimetallic part is investigated. It has been established that for a ...strong connection of metals, melting of the bronze insert and joint sequential cooling and solidification of the metals are required. Numerical method for determining the filling temperature and the mass of liquid steel for a certain bronze insert has been developed; various filling options have been considered. Experimental research on the production of bimetallic parts (blanks for slide nuts) by lost foam casting has been carried out. The possibility of producing bimetallic bronze-steel parts of sufficient strength (when the design conditions of filling are met) has been confirmed. The connection surface of the alloys is even, no cracks were found.
The technology of melting and secondary processing of electrical silicon steel and the changes in the content of oxide nonmetallic inclusions (NIs) in the metal at the stages of its secondary ...processing and casting is analyzed. Fractional gas analysis and scanning electron microscopy with electron-probe microanalysis are used to study samples of three heats taken at the stages of secondary processing and casting of electrical silicon steel. The total oxygen and nitrogen content and the amount and the main types of oxide NIs (silicates, aluminosilicates, spinels) in the samples are determined. The increase in the amount of spinel NIs in the metal samples is assumed to be related to the influence of deoxidizers, and the increase in the oxygen and nitrogen content in the samples taken in a steel degassing plant and in a tundish during heat I can indicate the influence of secondary oxidation at these processing stages. Commercial heat logs are analyzed and thermodynamic calculations are performed in order to determine the factors affecting the destruction intensity of the steel-teeming ladle lining and the increase in the content of NIs and carbon in the metal samples.
The manufacture of ground stone tools has long been a topic of interest for archaeologists. Ground stone tools made of specific stone types (e.g., limestone, basalt, granite) have been investigated ...with regards to the technology chosen by craftsmen, the manufacturing process, working tools and tool mark analysis. Here, we present the results of an experimental study of the manufacture of a basalt mortar. In particular, the strategy we adopted in designing this study was to present a method for producing a basalt mortar by pecking and abrading with basalt tools. The study was designed and conducted by A. Squitieri and D. Eitam, while the mortar was made by the sculptor D. Yassur. The goals of our experiment were to observe and document the choices made by the sculptor in creating the mortar, starting from the selection of a basalt cobblestone as the raw material, the tools (made from basalt) he used and the ways he used them. We detected practical problems the sculptor had to overcome during the process, the amount of debitage, and the nature of tool marks in the mortar cavity after the manufacturing process. We documented the entirety of the experiment through photographs and videos. Our experimental production using the expertise of a professional sculpture and his thorough knowledge of basalt offers a better understanding of basalt artefact manufacture, the physical properties of the raw material and the interaction between basalt tools and basalt raw material.
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