The article presents data on changes in the protein content of bee pollen due to different storage methods. In May, during the collection of bee pollen by bee colonies, in the conditions of the farm ...located in the Stryi district of the Lviv region, more than 30 types of flower pollen entered the nest. At the same time, for species identification, acetolysis of seven types of flower pollen was carried out, which differed in the maximum amount of arrival: apple (Malus), dandelion (Taráxacum), winter rape (Brassica napus), buckwheat (Fagopyrum esculentum), clover (Trifolium pratense), chestnut (Castánea) and raspberry (Rúbus idáeus). To study the nitrogen content according to the Kjeldahl method, all pollen was divided into three groups according to the storage method. Bee pollen of the first group was considered fresh. In it, the nitrogen content was determined immediately after determining the species. Calculations showed the maximum crude protein content in this group. Of all types of bee pollen that were determined to be fresh, the maximum amount of protein was found in bee pollen collected during the flowering of winter rape (Brassica napus) and apple (Malus). Its average content is 24.9 ± 2.09 and 23.4 ± 1.77 %, respectively. As a result of freezing at a temperature of 18 ºС and its storage for 8–12 months, the protein content practically did not change and decreased by only 0.3–0.9 %. A slight tendency to decrease the amount of nitrogen in bee honey was also found when stored in a dried state. Bee pollen, stored for 8–12 months under different conditions, was fed to newborn honey bees and kept in entomological boxes. It was found that bee pollen storage conditions affect honey bees' food consumption rate. The minor attractiveness of the feed was found in the dried bee pollen. The absence of a connection between the content of crude protein in feed and the rate of its consumption by bees was investigated.
The development of crop and animal husbandry is not possible without bees. Moreover, in beekeeping, emphasis is placed on reproducing honey bees to increase the aerial collection work. To solve the ...tasks, specialists work to improve the honey base, breed and keep bees, etc. Moreover, the main factor that affects the productivity level is the quality of the uterus. There is a need for additional study of factors that positively affect oogenesis in honey bee queens. The work aimed to study the influence of high-protein nutrition on the growth and development of Carpathian queens. The article presents data on the influence of feed quality on the exterior and interior indicators of reared bees and infertile queens. Three groups of families-teachers have been formed. In the families of the control group, all perg frames were removed. However, flying bees had free access to pollinators within the productive flight. The mass of carbohydrate feeds ranged from 8 to 9 kg. The bees of the first experimental group had the opportunity to consume perga from more than 15 types of plants. The most significant mass fraction of feed was perga formed from apple pollen. As protein fodder, families were given two perg honeycombs with a total weight of 1.1–1.3 kg. The protein content in the feed of the first group averaged 19.5 ± 1.2 %, and total lipids – 6.7 ± 0.5 %. The same mass of perga was placed in the nests of the II research group – female tutors. However, 80–90 % of the perg frames were formed from bee pollen of winter rapeseed. The average protein content in the samples taken from the perga combs of the second research group was 26.4 ± 1.4 %, and total lipids – 7.5 ± 0.3 %. As a result of the consumption of these feeds in the first experimental group, the maximum load of the honey bee was 57.3 mg, which is 10.9 % more compared to the control (Р< 0.05). Positive dynamics regarding the mass of nectar in the hive of flying bees were found in the bees of the II research group. The average weight in this group was 15.3 % higher than the control's and was 57.3 ± 1.16 (Р < 0.01). The acini size of the pharyngeal glands was significant (Р < 0.001) in bees that were additionally fed with rapeseed bee pollen. It should be noted that the consumption of feed containing 26.5% protein caused an increase in the size of secretory cells by 21.8 %.
Modern agricultural systems involve the use of large monocultures, which significantly limits the variety of flowers for bees. The article presents data on the biochemical composition of monofloral ...bee pollen and its influence on the development of pharyngeal glands in honey bees. The conducted studies give reason to believe that the protein content in bee pollen depends on the species origin and the preservation method. The studied samples for protein content show that its amount ranges from 11.9 to 24.9 %. The maximum amount of protein was found in fresh rapeseed and apple bee pollen. To study the influence of monofloral diets on the growth and development of the pharyngeal gland, 9 groups of analogous bee families were formed, 3 in each, which were fed three types of feed. The first type is fresh bee pollen from the following plants: apple tree, dandelion, winter rapeseed, buckwheat, clover, chestnut, raspberry. The second type is a similar bee pollen, only after a year of deep freezing storage. The ration of the third species consisted of the indicated bee pollen only in the process of harvesting it was dried. Along with this, the formed group of bee families was divided into two more subgroups. Some consumed mixed feed in equal proportions, others did not have any protein feed. The duration of the experiment was 15 days. On the 10th day, the development of acini of the pharyngeal gland was determined. The morphometry of the acini and the dynamics of vesicle filling indicate that the best indicators were found in the group of bees that consumed mixed bee pollen. A highly beneficial increase in the length and width of the acini of the pharyngeal gland was revealed by 36.4 and 34.7 % compared to bees that did not consume pollen at all. A group of bees that received fresh rapeseed and apple seed in their diet fully demonstrated their potential for royal jelly production. The worst development of the pharyngeal gland was found in the group of bees that consumed dried dandelion nectar. In this group of bees, the area of the acini ranged from 15.5 to 16.4 thousand μm2. The relationship between the protein content in the diet and the degree of development of the pharyngeal gland was revealed. Of the researched methods of its preservation, the conditions of deep freezing turned out to be the best. The use of experimental monofloral diets has a negative effect on the internal indicators of the body of honey bees. Key words: Apis mellifera L., pharyngeal gland, nutrition, protein, bee pollen, pollen storage.
Claude Imbert est professeure émérite au Département de philosophie de l’École normale supérieure (Ens) de la rue d’Ulm qu’elle a longtemps dirigé. Ses recherches et ses publications portent sur ...l’histoire et l’anthropologie de la logique, l’histoire de la peinture et des systèmes symboliques, l’épistémologie et la philosophie du langage, la philosophie contemporaine française et anglo-saxonne. La place centrale occupée par l’anthropologie dans sa réflexion explique qu’un À Propos soit propos...
Better student understanding of the dynamic trends in graduate employment requires the development of the author's description of this multidisciplinary social problem.
This educational paper is ...focused on an author-proposed engineering-friendly description of oscillatory dynamics in the employment market for university graduates.
This didactical paper widely uses computational methods of oscillations theory, theory of electrical and hydraulic circuits as well as concepts of physical analogies and similarity.
The generalized character of the employment-related oscillations in the studied social system of employees was didactically enhanced through the original introduction of two technical analogies with similar oscillations in the electrical system of an LC-field-effect transistor oscillator and the mechanical system of a hydraulic ram pump.
The author-proposed triple physics-and-engineering analogy for the periodic oscillations in the socio-economic problem in graduate employment provides a broadening of the cross-disciplinary ideas of engineering students about oscillatory dynamics in the social, electrical and hydraulics systems. It was found in the case of the Donbass State Engineering Academy (Kramatorsk, Ukraine), that this original author's approach provides simultaneous enhancement of the cross-disciplinary undergraduate engineering curriculum in the courses of economics, management, higher education pedagogy, physics, hydraulics and electrical engineering.
It is a common practice in pressure forming to make an Equal Channel Angular Extrusion (ECAE) of a workpiece through a die with channel intersection angle 2θ = 90° using a standard punch of brick or ...cylindrical shape with 2θ0 = 90°. However Nejadseyfi et al (2015) have applied a beveled 2θ0-punch to the process of ECAE through a standard angular die of Segal geometry with 2θ = 90° and 2θ0 ≠ 2θ. The scope of the article is focused on an alternative numerical study of Nejadseyfi-ECAE-Scheme using techniques of Computational Fluid Dynamics (CFD). A finite-difference method was applied to the numerical solution of the boundary value problem for the Navier-Stokes equations in the form of a vorticity transfer equation. The complex of 2D plots for CFD-derived fields of flow lines and flow velocities and 3D plots for spatial distributions of flow velocities and tangential stresses were firstly derived for Nejadseyfi-ECAE-Scheme during viscous flow of polymer workpiece models through angular die with 2θ = 90° for the different punch inclination angles 30° ≤ 2θ0 ≤ 150°. It was found that Nejadseyfi-ECAE-Scheme provides enhancement of the rotary modes of intensive deformations during ECAE. Results provide visualization of velocity gradients and macroscopic rotation and the illustration of Nejadseyfi et al’s ideas from an alternative CFD-based viewpoint.
The present article is focused on a 2D computational fluid mechanics study of local viscous flow dynamics and the formation character of rotary modes of deformation during Equal Channel Multiple ...Angular Extrusion (ECMAE) of a polymer workpiece fluid model through a U-shaped die with parallel slants in channel intersection zones. The present local flow problem was experimentally analyzed using physical simulation methods and theoretically studied with numerical fluid mechanics techniques. The computational approach has been grounded on the numerical finite difference solution of the boundary value problem for the Navier-Stokes equations in the curl transfer form for the local viscous flow of incompressible Newtonian fluid through a U-shaped rectangular die with parallel slants. The derived research results allow us to draw a conclusion that the implementation of a geometric design of parallel slants within a 2-turn U-shaped die results in localization of the maximum tangential stresses within the workpiece volume to the vicinity of these parallel slants during ECMAE.
The objective of this article is the description of advantages of a slanted die geometry, used for equal channel angular extrusion (ECAE) of materials. The prime novelty statement of the present ...research is an experimental flow pattern, obtained with circular gridlines and a numerical solution of a viscous flow 2D problem for the slanted die, derived with Navier–Stokes equations in curl transfer form. The geometry of the slanted die was chosen for the case of a rectangular die with channel intersection angle 2
θ =
90° and with parallel slants in the channel intersection zone, where the slant width is equal to the inlet and outlet channel widths. Computational material flow kinematics, macroscopic rotation patterns, material flow velocity fields, tangential stresses, and punching pressure fields during viscous materials ECAE have been derived with a numerical finite-difference solution of the curl transfer equation for 2D viscous flow of incompressible continuum during ECAE. Theoretical results have been verified with physical simulation experiments by the introduction of initial circular gridlines. Both theoretical and computational results confirm the suitability and technological advantages of dies with parallel slants over the known Segal and Iwahashi dies for ECAE, as slanted convergent dies enable the reduction of the dead zone size and provide the minimization of dangerous macroscopic rotation during ECAE processing of both metal and polymer materials.
The continuing development of new deformation schemes for material pressure forming resulted in the appearance of new technological process of Expansion Equal Channel Angular Extrusion (Exp-ECAE), ...which was proposed by Sepahi-Boroujeni and Fereshteh-Saniee in 2015. The present original research is a novel approach to an alternative hydrodynamic study of the Exp-ECAE deformation scheme with wide use of the numerical techniques of computational fluid dynamics (CFD). Additional mechanical degrees of freedom (DOFs) for Exp-ECAE die tooling equipment were first introduced by accounting for the dynamic effects of independent translational motion of the external movable walls of an Exp-ECAE angular domain. The proposed novel paper provides the possibility for original engineering-friendly visualisation of dead zone formation in the process of Exp-ECAE pressure forming. Multiple results of CFD-based numerical modelling show new promising ways for engineering minimisation of dead zone areas through alternative triggering of different DOFs of Exp-ECAE die tooling resulting in independent transport motion of the external walls of an Exp-ECAE angular domain.
Abbreviation: SPD is Severe Plastic Deformation; ECAE is Equal Channel Angular Extrusion; Exp-ECAE is Expansion Equal Channel Angular Extrusion; CFD is computational fluid dynamics; DOF is degree of freedom.
PDF
