Determination of height equivalent projection crossing drum with an odd number of knives

Стаття присвячена теоретичному дослідженню впливу еквівалентної проекції висоти bек на точність визначення сили опору повітря барабану з ножами. Зроблено спробу уточнити площу опору в залежності від кутового положення та кількості ножів барабана котка-подрібнювача. Дослідження впливу еквівалентної проекції висоти на точність опису сили опору повітря барабану з непарною кількістю ножів показали, що відносна похибка зменшується у 1,5 рази, що пояснюється виключенням впливу невизначеності початкового кутового положення барабану. During the last few years Ukraine was filled with nontraditional and in some cases unknown technologies of crop science. The changes started by using imported harvesters which left practically all residues on the field. This practice allowed increasing the productivity of picking processes and to shorten the terms of harvest period but there appeared the problem of further processing of plant residues. The Ukrainian producers chose the simplest way to solve it and used disc equipment for soil cultivation. As a result the structure of surface soil was damaged, valuable agro-technical aggregates were mashed, which led to their transformation into dusty unstructured condition. There was also overtamping of subsoil, disfunction of the processes of aeration and infiltration, decrease of the storage of productive soil water in lower levels. Special machines are usually used in these cases abroad which are debris pulverisers. In Ukraine these machines are not well known, expensive and perceived by agricultural producers as part of the technological process which needs extra costs and not obligatory. Besides, according to the special design of every of these machines they do not provide necessary pulverization in the traditional for Ukraine production technologies. In order to determine the accurate draught of the crimp-roller it is necessary to take into account the force to overcome air resistance. The article presents theoretical research of the influence of introduction of equal-area projection of the height on the accuracy of calculation of the resistance power of the air of the cylinder drum with blades. The effort was made to specify the area of resistance depending on the angle setting and the number of blades of the crimp-roller. Research of introduction of the equal-area projection of the height on the accuracy of description of the power of air resistance of the crimp-roller showed that the fractional error decreases in 1,5 times. This is explained by the absence of the influence of uncertainty of the initial angle setting of the cylinder drum

Textural Characteristics of Resorcinol—Formaldehyde Resin and Temperature Behavior of Bound Water Affected by Co-Adsorbed Trifluoroacetic Acid or Pyridine in Weakly Polar Organic Media

Resorcinol–formaldehyde resin (RFR) was synthesized as a porous material characterized by specific surface area of 140 m 2 /g and pore volume of 0.59 cm 3 /g with major proportions of broad mesopores and macropores. The interfacial behavior of water at low (h = 0.05 g of water/gram of dry RFR) and high (h = 2 g/g) hydration degrees depends on temperature and pore size filled by unfrozen water because its freezing-point depression increases in narrower pores. When water is mixed with co-adsorbates, the effects of such co-adsorbates as non-polar, weakly polar and polar organics depend on the amounts and the pore sizes. Even at a low hydration degree (h = 0.05 g/g), a portion of water can be displaced from pores by organic co-adsorbates because water has a relatively weak interaction with the RFR surface

Magneto-Sensitive Ni/C Adsorbents: Synthesis, Properties and Applications

A series of microporous carbons (chars) containing various amounts of magnetic Ni nanoparticles were prepared using a simple procedure. The resorcinol–formaldehyde polymers containing nickel(II) acetate was carbonized to produce chars (labelled as Ni/C-20, Ni/C-35 and Ni/C-50). All chars were characterized by X-ray diffraction, Raman spectroscopy, nitrogen adsorption and scanning electron microscopy methods. The formation of Ni crystallites (18 nm in size) occurs in carbon spheres measuring 1–2 μm in diameter. The Raman spectra show that the content of Ni influences the carbon structure. Dye-separation performance by Ni/C was investigated using methylene blue. The adsorption capacity was 26.6, 20.8 and 15.1 mg/g for Ni/C-20, Ni/C-35 and Ni/C-50, respectively