Influence of various parameters on the vegetable raw material pelleting process and pellets quality (review)

Determining the regularities of the process of pelleting vegetable raw materials is relevant for the improvement of technologies and technical equipment in order to reduce energy intensity and improve the quality of pellets. The generalization of the results of the research aimed at studying the influence of various parameters on the process of pelleting vegetable raw materials and the quality of feed and biofuel pellets is the purpose of the research. A selection and systematic review of the scientific literature on the subject of the study for the period of 2007-2022 has been carried out. The analysis has proved that heat pre-treatment and moistening of vegetable raw materials, as well as their composition and particle size are the factors that have the greatest impact on the quality of feed and biofuel pellets. Increasing the pressure in the range of 20...200 MPa results in increasing the pellets durability. A die temperature of around 100°C is optimum for obtaining dense pellets of highquality from vegetable raw materials. The design parameters of the pelletizer play an important role in obtaining high-quality pellets when processing vegetable raw materials. The design of the inlet in the form of a tapering cone helps to reduce energy consumption and pelleting pressure. An increase in the ratio of the die channel length to its diameter exponentially increases the pelleting pressure and its energy intensity. The interplay between the physical processes occurring in the pelletizer makes it difficult to interpret the impact of each parameter on the pelleting process, so different authors have different assessments of the contribution of individual factors in producing high-quality pellets. Therefore, the interaction between the individual pelleting parameters and their influence on the results of the process should be examined more precisely

SARS-CoV-2 mRNA vaccinations fail to elicit humoral and cellular immune responses in patients with multiple sclerosis receiving fingolimod

BACKGROUND: SARS-CoV-2 mRNA vaccination of healthy individuals is highly immunogenic and protective against severe COVID-19. However, there are limited data on how disease-modifying therapies (DMTs) alter SARS-CoV-2 mRNA vaccine immunogenicity in patients with autoimmune diseases. METHODS: As part of a prospective cohort study, we investigated the induction, stability and boosting of vaccine-specific antibodies, B cells and T cells in patients with multiple sclerosis (MS) on different DMTs after homologous primary, secondary and booster SARS-CoV-2 mRNA vaccinations. Of 126 patients with MS analysed, 105 received either anti-CD20-based B cell depletion (aCD20-BCD), fingolimod, interferon-β, dimethyl fumarate, glatiramer acetate, teriflunomide or natalizumab, and 21 were untreated MS patients for comparison. RESULTS: In contrast to all other MS patients, and even after booster, most aCD20-BCD- and fingolimod-treated patients showed no to markedly reduced anti-S1 IgG, serum neutralising activity and a lack of receptor binding domain-specific and S2-specific B cells. Patients receiving fingolimod additionally lacked spike-reactive CD4(+) T cell responses. The duration of fingolimod treatment, rather than peripheral blood B and T cell counts prior to vaccination, determined whether a humoral immune response was elicited. CONCLUSIONS: The lack of immunogenicity under long-term fingolimod treatment demonstrates that functional immune responses require not only immune cells themselves, but also access of these cells to the site of inoculation and their unimpeded movement. The absence of humoral and T cell responses suggests that fingolimod-treated patients with MS are at risk for severe SARS-CoV-2 infections despite booster vaccinations, which is highly relevant for clinical decision-making and adapted protective measures, particularly considering additional recently approved sphingosine-1-phosphate receptor antagonists for MS treatment

Determination of rational number of heat recovery units for the barn for 400 heads

Introduction. Matters of selection and use of units for exhausted air heat utilization in the barn room are considered. The work objective is rationale for choosing the number of heat recovery devices that provide the greatest economic benefit when operating in the room for 400 animals.Materials and Methods. Determination of the number of energy-saving equipment units is due to several factors. The key one is the ever varying amount of air exchange in the barn depending on the outer air parameters. At this, the operating conditions in the southern regions of the country are taken into account. Mathematical models describing dependence of the technical-and-economic indices on the number and operating period of the disposal plants are proposed. The correlationregression analysis of the dependences obtained is made. The technical-and-economic assessment of the use of heat exchangers is carried out on its basis. Contour plots of the objective functions of the electric power consumption and operating costs are presented depending on the operating period and the capacity of energy-saving plants. A comparison method is used to identify the most efficient performance of the heat exchanger with the varying value of air exchange.Research Results. The desired number of heat exchangers, which provide the required air exchange in the livestock house, is determined. New mathematical models are developed for calculating the efficiency of utilization facilities taking into account the capacity and operating period. Dependences of the change in running costs on the performance efficiency of the utilizers are established. The number and type of the heat recovery units is determined. When these utilizers are in use, the greatest net present value is achieved.Discussion and Conclusions. The results obtained can be used to develop energy-saving systems under stock-rearing. The proposed mathematical models for calculating operational costs allow for a pre-feasibility study on the use of plate heat exchanger in livestock buildings

Effect of design and kinematic parameters on energy requirement in inclined screw mixer

Introduction. Rational parameters and modes of an inclined batch screw mixer are validated to achieve the lowest energyintensive feed mixing under observance of the zootechnical requirements for the feed quality on uneven mixing. The establishment of functional dependences between parameters and modes enables to design power-efficient equipment for the on-farm feed production.Materials and Methods. Experimental studies of the feed mixing were implemented on an inclined screw batch feed mixer. The experimental design included variation of four independent factors: mixer shaft speed, filling ratio of the mixing chamber, mixing time, and mixing chamber angle. Mixing irregularity and energy intensity of the process were taken as optimization criteria characterizing the mixing efficiency.Research Results.The optimization criteria versus the variability level factor, which are two-dimensional sections of the second-order response surfaces, are plotted. The rational values at mixing irregularity of less than 5% were as follows: mixer shaft speed was 27.5-36.5 min-1 , filling ratio of the mixing chamber was 0.43–0.51, mixing time was 3.0–4.2 min, mixing chamber angle was 22°–25°. At such parameter values, the mixing irregularity will be minimal, and it will be 4.10– 4.18%, and the process intensity is from 2.08 to 2.16 kW • h/t.Discussion and Conclusions. The dependences obtained as a result of the experimental studies allowed establishing the domain of rational design parameters and modes of an inclined batch screw mixer. The results obtained can be used in further studies under the development of initial requirements for the creation of new technical means with a gravitation effect of intensive mixing

Study on extruding process of grain concentrate mixture with chopped green mass of legumes

The work objective is to study an advanced way of enhancing the nutritive value of the mixed feed by co-extrusion of the grain mixtures with chopped green legumes that differ in high content of vitamins and protein. The task of this investigation is an experimental determination of rational parameters and operating modes of the equipment for the extrusion process. Standard techniques are used to study the extrusion process when the properties of raw materials and modes of the extruder EC-75 (75kg/hr) change: extrudable mixture humidity, weight percentage of the chopped green mass in the mixture, and the extruder screw frequency of rotation at different feed rate of the mixture. The residual content of β-carotene as a quite valuable but impermanent component of the received product is used as a key marker of the process. The restrictive conditions are organoleptical properties of the product, humidity after cooling, and occurrence of the undistorted grain material. Energy efficiency of the process is evaluated by the criteria of the specific energy consumption. The study results of the extrusion process are as follows. Its optimal characteristics are determined: mixture supply is 60 kg / hr, mixture temperature at the matrix outlet is 120-125°C, content of the chopped green mass in the mixture is 14-15%, screw rate speed is 220-240 rpm with the specific energy consumption of 90-95 kW hr/t

7-order enhancement of the Stern-Gerlach effect of neutrons diffracting in a crystal

International audienceWe measured the spatial splitting of a non-polarized neutron beam passed through a crystal under diffraction conditions in heterogeneous magnetic field (analog to the Stern-Gerlach effect) into two polarized components with opposite polarization. The measurements were carried out using Laue diffraction scheme, small gradients of the magnetic field and Bragg angles close to orthogonality θB=(78−82)∘ . After a flight path in crystal of 21.6 cm a splitting of 4.1±0.1 cm was achieved (using a field gradient of ∼3 G/cm and a diffraction angle of 82∘ ). In the absence of a diffraction (crystal) but otherwise the same flight path and field gradient the spatial splitting would be ∼4⋅10−7 cm. From those we deduce an experimental amplification factor in the order of about ∼2⋅105tan2⁡θB due to the use of diffraction in crystals, which agrees with theory

Features of the Phase and Structural Transformations in the Processing of Industrial Waste From the Production of High­alloyed Steels

We have investigated the physical and chemical properties of the alloy obtained by reduction smelting using wastes from the production of highly-alloyed steels and alloys. This is necessary to determine the technological aspects that reduce the loss of doping components when obtaining and using a doping alloy. The study results indicate that at the charge's oxygen-to-carbon ratio of 2.25, the alloy consisted mainly of a solid solution of doping elements in γ-Fe. At the charge's oxygen-to-carbon ratio of 1.67, we also observed Fe3C, followed by an increase in the intensity of carbide manifestation at the oxygen-to-carbon ratio of 1.19. Photographs of the microstructure clearly showed several phases with a different ratio of doping elements. The Ni content in the examined sections of various phases changed within 1.38‒46.38 % by weight, Cr ‒ 3.45‒45.32 % by weight, W ‒ 1.51‒27.32 % by weight, Mo ‒ 0.48‒10.38 % by weight. Mo, W, Nb mostly concentrated in individual particles. The Nb content in some inclusions reached 47.62 % by weight. Analysis of the study results has shown that the most beneficial charge's oxygen-to-carbon ratio is 1.67. At the same time, the phase composition is dominated by a solid solution of doping elements in γ-Fe. The proportion of residual carbon, which was in the form of a carbide component, accepted values in the range of 0.52‒2.32 % by weight while providing the necessary reducing capacity when using the alloy. Our research has identified new technological aspects in the processing of highly-alloyed anthropogenic waste when obtaining an alloy with a relatively low residual carbon content. The resulting parameters of the resource-saving doping material ensure the possibility to replace some of the standard ferroalloys when smelting steels with certain carbon content restrictions