Comparison of the modifying effect of rice ashand buckwheat husk in epoxy antifriction coatings

This paper discusses the issue of utilization of rice and buckwheat husks, a comparison of their modifying effect in epoxy antifriction coatings, for this, the elemental composition of these fillers was determined using X-ray fluorescence analysis, their structure was analyzed by scanning electron microscopy, and the acid-base characteristics of the filler surface were determined by the pH method., the surface area of the pores of the ash of rice and buckwheat husks, their oil absorption were calculated, a sol-gel analysis was carried out to assess the density of the spatial network of filled epoxy coatings, and their wear resistance and hardness were determined. In the course of the research, the optimal temperature for obtaining ash from rice and buckwheat husks was established, which contributes to an increase in wear resistance, hardness and a decrease in the static friction coefficient of filled epoxy coatings. It is shown that the optimal temperature for obtaining rice husk ash is 500 C, and buckwheat husk ash 800 C. At the same time, rice husk ash is a more effective filler for epoxy polymers than buckwheat husk ash, since it increases the hardness of materials and provides a greater decrease in their friction coefficient.

ADSORPTION OF OBSOLETE SLUDGE, PEAT, BUCKWHEAT HUSKS AND COMPOSITIONS FROM THEM

The problem of accumulation of obsolete silt deposits at aeration stations is relevant for the whole territory of Ukraine. This can lead to environmental hazards. Therefore, the task of processing silt deposits with the creation of granules based on them with the addition of peat and buckwheat husks. Van Bamelen's tensometric (static) method was used to determine the equilibrium humidity of the experimental samples depending on the relative humidity . As a result of researches kinetic curves of adsorption over obsolete silt deposits, peat, buckwheat husk and the three-component composition created on their basis are received. Kinetic adsorption curves indicate a slow process. The adsorption curves of the three-component composition have the character of curves of obsolete sludge, which have a non-uniform character. The obtained equilibrium humidity does not exceed the standard humidity for fuel pellets. The adsorption isotrams of the three-component composition and its components are determined, from which the equations of experimental and linearized isotrams are obtained. The analysis of experimental isotherms allows to relate them relatively to the isotherms of adsorption IV, which are observed in inorganic oxides and in other porous bodies. For the first time, the adsorption properties of three-component compositions based on peat, sludge and buckwheat husk were studied. The obtained equilibrium humidity of the compositions does not exceed the standard humidity for fuel pellets (is 20%) and is 6 - 7%. Therefore, they can be used for combustion in biomass boilers. The resulting ash can be used for the production of bricks, cement and other building materials. During storage of composite granules in order to prevent loss of their technological properties, it is recommended to maintain humidity at the level of 60 - 70%.

Effect of Ultra-Fine Grinding on the Structure of Plant Raw Materials and the Kinetics of Melanin Extraction

Enhancing the extraction rate is one of the key objectives in optimization of extraction of substances from biogenic raw materials. Ultra-fine grinding of plant raw materials (to achieve particle size less than 300 µm) is a very appealing method for increasing the extraction rate using relatively simple equipment. However, this approach often fails to yield the desired result. This study focuses on the kinetics of melanin extraction from two types of raw materials: fungus Ganoderma applanatum and buckwheat husk. Particle size is shown to be just one of the key factors. The degree of order of plant-based feedstock strongly affects the intraparticle diffusion constants and can be a parameter controlling the diffusion rate. It has been shown that there exist optimal degrees of disorder of the crystal structure of plant raw materials, which have a dome-shaped dependence pattern and allow one to increase the diffusion coefficient by several dozen times. The kinetics of melanin extraction was described by some kinetic models that include the first order equation, the Baker and Lonsdale model, the Axelrud equation, and the Ritger–Peppas model.

A Review on Epidemiological and Clinical Studies on Buckwheat Allergy

Background: Cultivated buckwheat include two species originating from China: common buckwheat (Fagopyrum esculentum) and tartary buckwheat (Fagopyrum tartaricum). Buckwheat can cause IgE-mediated allergy, including severe allergic reactions and anaphylaxis. Exposure can occure when eating buckwheat food (food allergen), when producing or handling buckwheat food (occupational exposure) or when sleeping on buckwheat husk pillows (houeshold environmental exposure). Methods: A search on buckwheat allergy in the medical datbase PubMed from 1970–2020. Result: A number of allergenic proteins have been identified in common buckwheat (e.g., Fag e 1, Fag e 2 and Fag e 3) and in tartary buckwheat (e.g., Fag t 1, Fag t 2, Fag t 3). Clinically relevant cross-reactivity has been described between buckwheat and peanut, latex, coconut, quinoa, and poppy seed. The prevalence of buckwheat allergy in the population can be estimated as 0.1–0.4% in Japan, Korea and buckwheat consuming areas of China. Among patients in allergy clinics in different countries, 2–7% has confirmed buckwheat allergy. School studies from Japan and Korea found 4–60 cases of buckwheat-related anaphylaxis per 100,000 school children. The incidence of severe allergic reactions to buckwheat, including anaphylaxis, can be estimated as 0.1–0.01 cases per 100,000 person-years. Conclusions: Buckwheat allergy is a neglected allegy deserving further attention but severe allergic reactions are rare.

Qualitative and Quantitative Assessment of Buckwheat Husks as a Material for Use in Therapeutic Mattresses

Buckwheat husks are used in many therapeutic products such as pillows, mattresses, seats, etc. This material is proposed by producers for example for discopathy, back pain and head vasomotor disorders. Our studies evaluated the impact of using cotton mattresses with buckwheat husk fillings on people’s health condition. The main research was carried out on the group of 60 people divided into 3 groups (1—people with skeletal system problems, 2—people spending a lot of time lying with the probability of pressure ulcer formation and 3—healthy people). In addition, different tests have been carried out on the possibility of colonization of mattresses by fungi, bacteria and arthropod pests, and rheological, chemical and flammability tests. The research material in the form of buckwheat husks was tested in a diverse way. All tests indicate high usefulness of husks for therapeutic activity. This material was contaminated with fungi, bacteria and pests at a very low level, related to the natural colonization of buckwheat nuts during harvest and storage. The quality of the husks was also confirmed in rheological, chemical and flammability studies. Finally, this has also been confirmed in surveys conducted on people with health problems. The analyses show that the buckwheat husk is an excellent material that can be used to fill prophylactic mattresses. This has been confirmed by the results of laboratory tests and opinions of respondents using mattresses filled with buckwheat husk.

BUCKWHEAT HUSK AND EPOXY RESIN BASED COMPOSITES FOR NOISE ABATING

The paper discusses promising way of utilization of the buckwheat husks for production of noise abating epoxy based composites for transport infrastructure and buildings industry. Composites of different densities from 400kg/m3 up to 650 kg/m3 have been prepared. The measurements of normal coefficient of sound absorption and sound transmission loss in the range from 500 Hz up to 6400 Нz are carried out. The absorption coefficient posses local maximum depending on the density of composites approaching the value of 0.99 at 3120 Hz for the density 400 kg/m3. The sound transmission loss of composites increases with density from the mean value of 10 dB for 400kg/m3 up to 60 dB for 650 kg/m3 that is comparable with well-developed artificial materials. The pristine buckwheat husks is thermally stable of up to 200-250°С that gives thermogravimetric analysis in the range from 30°С up to 500°С. The husks is suggested as the filler for production of epoxy resin based noise abating composites.

Agricultural waste buckwheat husk derived bifunctional nitrogen, sulfur and oxygen-co-doped porous carbon for symmetric supercapacitor and capacitive deionization

In electric double layer capacitor (EDLC), the capacitance is produced by the electrostatic charge separation at the interface between the electrode and the electrolyte. Capacitive deionization (CDI) is a novel...

Rationale for the use of buckwheat husk for the production of functional food colors

The aim of the work was to substantiate the use of buckwheat husk for obtaining a functional food colorant melanin. The objects of the study were samples of buckwheat husk Fagopýrum esculéntum and isolated water-soluble melanin. The isolation of melanin was carried out by extraction of buckwheat husk with 4% NaOH at a hydraulic modulus of 1:20. The sorption capacity of the melanin extract was determined by its interaction with copper salt solutions in an alkaline medium. It has been established that a distinctive feature of buckwheat hulls is its low ash content, a rather high fiber content – 24.7–26.5%, and a sufficient content of pectin substances – 7.2–7.7% and melanin – 15.7–16.2%. The husk can be used for further processing in order to obtain the food coloring melanin. The experiment proved the ability of a melanin sample to bind copper ions: one gram of a 0.5% solution of buckwheat husk melanin extract bounded 966.6 mg/ml copper, and the antioxidant activity of one gram of melanin extract corresponds to the antioxidant activity of 0.056 g of rutin. Thus, water-soluble samples of melanin isolated from buckwheat hulls can be used as food coloring agents, as well as antioxidants and biosorbents, which makes it possible to recommend them as functional food ingredients in food.