The assessment of distribution of GSM signal on the route with the difficult relief and mainly deciduous wood

This article is devoted to assessment of distribution of radio waves for GSM technology in the range of 900 and 1800 MHz. A fading calculation is conducted for a route with difficult relief with the mainly leafy forest. An imitation design was carried out by means of MATLAB environment for comparison of theoretical and practical results.

The paper-forming properties of hemp fire peroxide cellulose in combination with wood sulphate cellulose

Hemp fire (Cannabis sativa) was delignified with the reaction mix “acetic acid - hydrogen peroxide - sulfuric acid catalyst - water” under sulfuric acid concentration of 0.45%, liquid module of 6, and temperature of 85 ° C. The cellulose was ground to 34 … 36°SHR and mixed in different ratios in compliance with the simplex-centroid experimental design with bleached sulfate softwood and hardwood pulp. The influence of the mixed composition formulations on the main strength properties of paper castings has been studied. It has been concluded that technical cellulose obtained from hemp fire applying this method, can be used for paper products manufacturing in combination with sulphate cellulose from coniferous and deciduous wood.

Contamination with microscopic fungi measured by the concentration of ergosterol in dusts of various types of wood with different granulation

Contamination with microscopic fungi measured by the concentration of ergosterol in dusts of various types of wood with different granulation. Dusts are a mixture of compounds generated both in the anthropogenic and natural environment and they are a by-product of combustion and abrasion or crushing of solid materials. Dust generated in wood industry plants as a result of mechanical wood processing is particularly dangerous. Wood dusts - both dispersed in the air inside a production plant and deposited - also contain the work environment's so-called biological agents. This term refers to microorganisms and the structures and substances produced by these organisms, which have an adverse effect on the human organism and may cause numerous diseases. The aim of this study was to determine the level of contamination with microscopic fungi of dusts from various types of wood depending on the granulation. The method of analysis of the chemical ergosterol marker was used here, the concentration of which is correlated with the number of mycoscopic fungi. On the basis of the study, it was found that dusts with finer granulation from deciduous wood are characterized by a higher concentration of ERG, i.e. a higher level of contamination with microscopic fungi. It is important information from the point of view of health and safety at work.

Research of the properties of spent liquor from cooking of hardwood semi-cellulose at different ratio of green and white liquors

Основным полуфабрикатом для производства бумаги для гофрирования (флютинга), используемой в композиции тарного картона, является полуцеллюлоза из лиственных пород древесины. Производство полуцеллюлозы базируется напредварительной химической и последующей механической переработке древесной щепы или однолетних растений. Технология производства полуцеллюлозы с использованием в качестве варочного реагента - зеленого щелока позволяет упростить процесс приготовления варочного раствора и сократить схему регенерации химикатов из отработанных щелоков. Однако сведения о технологических параметрах варки, качестве полуцеллюлозы представлены недостаточно полно, отсутствуют подробные данные об избирательности процесса делигнификации лиственных пород древесины, произрастающих в СЗФО, а также недостаточно информации о составе и свойствах отработанного щелока, влиянии породного сырья на свойства щелоков. Исследование выполнено с целью изучения свойств отработанного (оранжевого) щелока, а именно его плотности, полученного при варке лиственной полуцеллюлозы с различным соотношением зеленого и белого щелоков. Основываясь на результатах исследований свойств отработанного производственного щелока от варки лиственной полуцеллюлозы на смеси белого и зеленого щелоков: 1) не выявлено значительного влияния изменения соотношения зеленого и белого щелоков при варке лиственной полуцеллюлозы на плотность отработанного щелока в диапазоне температуры от 15 до 90 °С и концентрации сухих веществ от 5 до 10%; 2) разработана математическая модель - полином 1 степени, - достоверно характеризующая зависимость плотности отработанного щелока от концентрации и температуры для производства лиственной полуцеллюлозы с различным соотношением зеленого и белого щелоков: ρ = 0,992 + 0,0083 · х - 0,0003 · t - 0,000012 · х · t - 0,00000032 · t 2 - 0,0001158 · х 2. The main semi-finished product for the production of fluting is semi-cellulose from hardwood. Semi-cellulose production is based on preliminary chemical and subsequent mechanical processing of wood chips or annual plants. The technology for the production of semi-cellulose using green liquor makes it possible to simplify the process of preparing the cooking solution and the recovery of chemicals from waste liquors. This method is used abroad, in our country the method of cooking semi-cellulose with green liquor is currently carried out at one of the enterprises in Russia. However, at the moment, information on the technological parameters of cooking and the quality of semi-cellulose is not fully presented, there are no data on the selectivityof the delignification process (removal of lignin) of deciduous wood when cooking with green liquor, as well as information on the composition and properties of the spent liquor. The study was carried out with the aim of studying the properties of waste (orange) liquor, namely its density obtained by cooking hardwood semi-cellulose with different ratios of green and white liquors. Based on the results of studies of the properties of waste industrial liquor from hardwood semi-cellulose cooking on a mixture of white and green liquors: no significant effect of the ratio of green and white liquors during hardwood semi-cellulose cooking on the density of waste liquor in the temperature range from 15 to 90 °С and the concentration of dry substances from 5 to 10%; a mathematical model has been developed - a polynomial of the 1st degree, - reliably characterizing the dependence of the density of the spent liquor on concentration and temperature for the production of hardwood semi-cellulose with different ratios of green and white liquors ρ = 0,992 + 0,0083 · х - 0,0003 · t -- 0,000012 · х · t - 0,00000032 · t 2 - 0,0001158 · х 2.

An Endophytic Trichoderma Strain Promotes Growth of Its Hosts and Defends Against Pathogen Attack

Plants host numerous endophytic microbes which promote plant performance, in particular under stress. A new endophytic fungus was isolated from the leaves of a deciduous wood tree Leucas aspera. Morphological inspection and multilocus phylogeny identified the fungus as a new Trichoderma strain. If applied to Arabidopsis thaliana and Nicotiana attenuata, it mainly colonizes their roots and strongly promotes initial growth of the plants on soil. The fungus grows on high NaCl or mannitol concentrations, and shows predatory capability on the pathogenic fungus Alternaria brassicicola. Colonized Arabidopsis plants tolerate higher salt stress and show lower A. brassicicola spread in roots and shoots, while arbuscular mycorrhiza formation in N. attenuata is not affected by the Trichoderma strain. These beneficial features of the novel Trichoderma strain are important prerequisites for agricultural applications.

Using Biofilter Packed with Different Wood Waste Charges for Purification of Air Contaminated with Benzene

The main aim of this work was the analysis and assessment of benzene removal from air using bio-filter packed with a mixture of wood waste. The results of this work show that the small scale bio-filter with various coniferous and deciduous wood waste charges is capable of efficiently removing benzene from polluted air stream. The analysis of different mixtures of wood waste charge, while pH value was kept at neutral (pH = 7), determined, that the best wood waste mixture is consisted of 70% coniferous wood (45% pine trees, 25% fir trees), 30% deciduous wood (20% maple, 10% hazel) which was consisted of 10–20 mm fraction particles and had porosity value of 46%. This bio-media was best used for benzene removal from contaminated air stream (E = 93.86–74.78%).

Two-wave Laser Method for Monitoring the Species Composition of Forest

Today the monitoring of forests is one of the actual tasks of environmental control. The most important problems of monitoring of forest resources are mapping of forests, determining species and age composition of forests and analysis of sanitary condition of forests.An effective method of monitoring the state of vegetation (including forests) is optical aerospace sensing. The methods of optical sensing of vegetation cover are currently passive, for the most part.However, passive methods are available to use for daylight only. Therefore, laser methods which can be used in wide range of light and atmospheric conditions are of interest.In this article there was carried out the comparative analysis and selection of the most effective sensing wavelengths in atmospheric transparency windows for two-waves laser method for determining forest areas with prevalence of coniferous or deciduous wood species.As an information index (coniferous or deciduous wood species) in this article the ratio of reflection coefficients of parcels of forest at two wavelengths was used. Pairs of wavelengths 1,54μ and 0,532μ; 1,54μ and 0,355μ are the most relevant for detecting forest areas with prevalence of coniferous or deciduous wood species.For quantitative assessment the efficiency of the laser method mathematical modeling was carried out. The results of mathematical modeling show that that the wavelengths of 0.532μm and 1.54μm are the most effective and provide scanning with probability of correct detecting ~ 0.99 and with false-alarm probability ~ 0.04.However, in terms of eye safety it’s better to choose wavelengths of 0.355μm and 1.54μm, because they allow to solve satisfactory the problem of determining forest areas with prevalence of coniferous or deciduous wood species with probability of correct detecting ~ 0.9 and with false-alarm probability ~ 0.14.