Fir Needles Research Articles

Affordable Production of Antioxidant Aqueous Solutions by Hydrodynamic Cavitation Processing of Silver Fir (Abies alba Mill.) Needles.

Extracts from parts of coniferous trees have received increased interest due to their valuable bioactive compounds and properties, useful for plenty of experimental and consolidated applications, in fields comprising nutraceutics, cosmetics, pharmacology, food preservation, and stimulation of plant growth. However, the variability of the bioactive properties, the complexity of the extraction methods, and the use of potentially harmful synthetic chemicals, still represent an obstacle to the spreading of such valuable natural compounds. Hydrodynamic cavitation is emerging as a promising innovative technique for the extraction of precious food components and by-products from waste raw material of the agro-food production chain, which can improve processing efficiency, reduce resource consumption, and produce healthy, high-quality products. In this study, a process based on controlled hydrodynamic cavitation was applied for the first time to the production of aqueous solutions of silver fir (Abies alba Mill.) needles with enhanced antioxidant activity. The observed levels of the in vitro antioxidant activity, comparable or higher than those found for reference substances, pure extracts, and other water extracts and beverages, highlight the very good potential of the hydrodynamic cavitation (HC) process for the creation of solvent-free, aqueous solutions endowed with bioactive compounds extracted from silver fir needles.

Species identification of European forest pathogens of the genus Milesina (Pucciniales) using urediniospore morphology and molecular barcoding including M.woodwardiana sp. nov.

Species of rust fungi of the genus Milesina (Pucciniastraceae, Pucciniales) are distributed mainly in northern temperate regions. They host-alternate between needles of fir (Abies spp.) and fronds of ferns (species of Polypodiales). Milesina species are distinguished based on host taxonomy and urediniospore morphology. In this study, 12 species of Milesina from Europe were revised. Specimens were examined by light and scanning electron microscopy for urediniospore morphology with a focus on visualising germ pores (number, size and position) and echinulation. In addition, barcode loci (ITS, nad6, 28S) were used for species delimitation and for molecular phylogenetic analyses. Barcodes of 72 Milesina specimens were provided, including 11 of the 12 species.Whereas urediniospore morphology features were sufficient to distinguish all 12 Milesina species except for 2 (M.blechni and M.kriegeriana), ITS sequences separated only 4 of 11 species. Sequencing with 28S and nad6 did not improve species resolution. Phylogenetic analysis, however, revealed four phylogenetic groups within Milesina that also correlate with specific urediniospore characters (germ pore number and position and echinulation). These groups are proposed as new sections within Milesina (sections Milesina, Vogesiacae M. Scholler & Bubner, sect. nov., Scolopendriorum M. Scholler & Bubner, sect. nov. and Carpaticae M. Scholler & Bubner, sect. nov.). In addition, Milesinawoodwardiana Buchheit & M. Scholler, sp. nov. on Woodwardiaradicans, a member of the type section Milesina, is newly described. An identification key for European Milesina species, based on urediniospore features, is provided.

Combined influence of external nitrogen and soil contact on plant residue decomposition and indications from stable isotope signatures.

External nitrogen (N) supply has been testified to exert important impacts on plant residue decomposition. The influence of N may be interactive with soil contact in terrestrial ecosystems. However, the joint mechanisms of decomposition of plant residues driven by soil contact and N addition remain incomplete. Using contrasting residues, including needles of Chinese fir (Cuninghamia lanceolata) (Cl) (relatively hard to degrade) vs. leaves of eucalyptus (Eucalyptus urophylla) (Eu) (relatively easy to degrade), a full factorial experiment was conducted by 360-day experiment to investigate the combined effect of N addition and soil contact on residue decay. As the microbe-manipulated decomposition could leave an imprint on the residue carbon (C) and N stable isotope, variations of the two signatures (δ13C and δ15N) were synchronously monitored. Our results firstly showed that added N sped up initial decomposition, while it played an opposite role in subsequent stage, and soil contact always stimulated decay. Under soil contact condition, we found a markedly more accelerating effect of N addition on decay of Cl than without soil contact. Linking with residue N dynamics, we thought that although N immobilized from soil could not completely meet microbial needs for decay of Cl, this N limitation was just relieved by added N, leading to this synergistic effect. At late decay stage, the N inhibiting influence was partly offset under soil contact condition, and this phenomenon was more dramatic for Eu. Our results lastly revealed that the 13C and 15N signatures mirrored and explained the underlying mechanisms of the above interactions. Overall, we concluded that external N and soil contact could interactively affect decay, depending on plant residue decomposability. These results would be used to accurately predict C sequestration for terrestrial ecosystems under heightened N scenario in the future.

A proteomic approach to seasonal adjustment in the enzyme complement of Korean fir (Abies koreana Wilson) needles

Korean fir is an endemic ornamental tree species facing population decline in Korea. To further understand the acclimatory adjustments it undergoes in response to seasonal extremes, we characterized some of the needle proteins that are upregulated during winter. Two-dimensional gel electrophoresis (2-DE), followed by MALDI TOF/TOF MS/MS and Mascot analyses, was used to visualize changes in protein profiles during acclimation to winter stress. From the 2-DE protein profiles of Korean fir needles, 226 protein spots were detected, many of which accumulated at higher levels during the winter. Among 17 proteins identified, 12 matched proteins associated with photosynthesis and with biotic and abiotic stresses, and eight were significantly upregulated under winter stress. Upregulated proteins included photosynthetic enzymes sedoheptulose-1,7-bisphosphatase and fructose bisphosphate aldolase of the Calvin–Benson cycle, four proteins related to oxidative stress tolerance, two proteins implicated in biotic defense, one heat-shock protein, and five unknown proteins. However, two other oxidative-stress-related proteins were present at high levels throughout the year, and a chitinase and the small subunit of ribulose-1,5-bisphosphate carboxylase showed no seasonal adjustments. Thus, Korean fir needles exhibited winter upregulation of some photosynthetic enzymes, coupled with increased photo protective thermal energy dissipation, and proteins related to abiotic and biotic stress resistance. Winter stress, which can include both low temperature and reduced water availability, in the subalpine region of Mount Halla led to an altered physiological equilibrium with increases in key Calvin–Benson cycle enzymes and increased enzymatic and non-enzymatic protection against oxidative stress.

Nitrogen Nutrition of European Beech Is Maintained at Sufficient Water Supply in Mixed Beech-Fir Stands

Research highlights: Interaction effects of coniferous on deciduous species have been investigated before the background of climate change. Background and objectives: The cultivation of European beech (Fagus sylvatica L.) in mixed stands has currently received attention, since the future performance of beech in mid-European forest monocultures in a changing climate is under debate. We investigated water relations and nitrogen (N) nutrition of beech in monocultures and mixed with silver-fir (Abies alba Mill.) in the Black Forest at different environmental conditions, and in the Croatian Velebit at the southern distribution limit of beech, over a seasonal course at sufficient water availability. Material and methods: Water relations were analyzed via δ13C signatures, as integrative measures of water supply assuming that photosynthesis processes were not impaired. N nutrition was characterized by N partitioning between soluble N fractions and structural N. Results: In the relatively wet year 2016, water relations of beech leaves, fir needles and roots differed by season, but generally not between beech monocultures and mixed cultivation. At all sites, previous and current year fir needles revealed significantly lower total N contents over the entire season than beech leaves. Fir fine roots exhibited higher or similar amounts of total N compared to needles. Correlation analysis revealed a strong relationship of leaf and root δ13C signatures with soil parameters at the mixed beech stands, but not at pure beech stands. While glutamine (Gln) uptake capacity of beech roots was strongly related to soil N in the monoculture beech stands, arginine (Arg) uptake capacities of beech roots were strongly related to soil N in mixed stands. Conclusions: Leaf N contents indicated a facilitative effect of silver-fir on beech on sites where soil total N concentrations where low, but an indication of competition effect where it was high. This improvement could be partially attributed to protein contents, but not to differences in uptake capacity of an individual N source. From these results it is concluded that despite similar performance of beech trees at the three field sites investigated, the association with silver-fir mediated interactive effects between species association, climate and soil parameters even at sufficient water supply.

Needle longevity of balsam fir is increased by defoliation by spruce budworm

Retention of 10–16-year-old balsam fir needles increased significantly with cumulative spruce budworm defoliation. Mean needle longevity on defoliated 50-year-old fir was almost double that for undefoliated 25-year-old fir. Conifers experiencing environmental change affecting photosynthetic capacity have been observed to compensate by adjusting foliage longevity and increasing retention of old foliage. Defoliation by spruce budworm [Choristoneura fumiferana (Clem.)] is one such change, therefore, it was hypothesized that conifers, such as balsam fir [Abies balsamea (L.) Mill.] may increase foliage life spans to compensate for losses of photosynthetic capacity to defoliation. Understanding foliage longevity is a key component of predicting foliage complement, which is the main driver of effects of defoliation on forest growth and productivity. Defoliation and needle loss were assessed on 16 age classes of foliage on mid-crown branches sampled from 134 mature balsam fir trees near Amqui and Causapscal, Quebec, and related to needle age and cumulative defoliation (summed annual defoliation from 2012 to 2016). A general linear mixed model fitted to the needle survivorship data accounted for 68% of the total deviance. The model interaction term of cumulative defoliation with foliage age indicated that for foliage ages less than about 9 years, increased cumulative defoliation resulted in lower needle survival, possibly because of backfeeding of spruce budworm on 5+-year-old foliage, while in the older age classes, needle survival increased with increasing cumulative defoliation. For the oldest, 11–16-year-old foliage age classes, 10–16% more foliage per age class was retained under severe defoliation than under light defoliation. As a result, median needle age increased from 9.5 to 10.4 years as cumulative defoliation increased from 0 to 500%. Mean needle longevity of 9.5 years for 50-year-old balsam fir with low defoliation observed in this study was considerably higher than the mean of 5.5 years previously observed for 22- to 27-year-old fir in Cape Breton, Nova Scotia. Such differences in needle longevity and retention would cause considerable differences in predictions of tree growth using foliage-based stand growth models.

Determination of the Volume of Water for Suppressing the Thermal Decomposition of Forest Combustibles

From the results of experimental studies of the processes of suppressing the thermal decomposition of the typical forest combustibles (birch leaves, fir needles, asp twigs, and a mixture of these three materials) by water aerosol, the minimum volumes of the fire-extinguishing liquid have been determined (by varying the volume of samples of the forest combustibles from 0.00002 m3 to 0.0003 m3 and the area of their open surface from 0.0001 m2 to 0.018 m2). The dependences of the minimum volume of water on the area of the open surface of the forest combustible have been established. Approximation expressions for these dependences have been obtained. Forecast has been made of the minimum volume of water for suppressing the process of thermal decomposition of forest combustibles in areas from 1 cm2 to 1 km2, as well as of the characteristic quenching times by varying the water concentration per unit time. It has been shown that the amount of water needed for effective suppression of the process of thermal decomposition of forest combustibles is several times less than is customarily assumed.

Amount of Water Sufficient to Suppress Thermal Decomposition of Forest Fuel

AbstractThis study examines how to stop the pyrolysis of fir needles, birch leaves, aspen twigs and their mixture using the minimum volumes of water. The combustion of forest fuels is suppressed by spraying water on their surface. The temperature of thermal decomposition is monitored throughout the layer of forest fuel by thermocouples. A high-speed camera and optical techniques allow us to study water spraying and its interaction with forest fuels. Finally, the study specifies the ranges of the minimum water volumes and the times of ending of the thermal decomposition of forest fuels. When analyzing the energy balance in the thermally decomposing forest fuel, a mathematical expression is formulated to predict the water volume sufficient to suppress thermal decomposition of forest fuel. This expression takes into account the ratio between the heat energy spent on water evaporation in pores of forest fuel and the heat energy of the reacting layer of forest fuel. The obtained dimensionless factor considers the main parameters of water spraying and the properties of forest fuel. This factor enables us to apply the research findings to forest fuel in various regions of the world.

Sampling design and required sample size for evaluating contamination levels of 137Cs in Japanese fir needles in a mixed deciduous forest stand in Fukushima, Japan

We estimated the sample size (the number of samples) required to evaluate the concentration of radiocesium (137Cs) in Japanese fir (Abies firma Sieb. & Zucc.), 5 years after the outbreak of the Fukushima Daiichi Nuclear Power Plant accident. We investigated the spatial structure of the contamination levels in this species growing in a mixed deciduous broadleaf and evergreen coniferous forest stand. We sampled 40 saplings with a tree height of 150 cm–250 cm in a Fukushima forest community. The results showed that: (1) there was no correlation between the 137Cs concentration in needles and soil, and (2) the difference in the spatial distribution pattern of 137Cs concentration between needles and soil suggest that the contribution of root uptake to 137Cs in new needles of this species may be minor in the 5 years after the radionuclides were released into the atmosphere. The concentration of 137Cs in needles showed a strong positive spatial autocorrelation in the distance class from 0 to 2.5 m, suggesting that the statistical analysis of data should consider spatial autocorrelation in the case of an assessment of the radioactive contamination of forest trees. According to our sample size analysis, a sample size of seven trees was required to determine the mean contamination level within an error in the means of no more than 10%. This required sample size may be feasible for most sites.

Mineral status of plants and soil in silver fir stands of the Silesian and Żywiec Beskidy (Western Carpathians)

For last decades the Silesian and Żywiec Beskidy have been affected by different types of anthropopression. Up to the nineties of the 20th century, forests of the area were affected by a high level of air pollutants transported mainly from the Upper Silesian and Ostrava industrial regions. From 2004 intensive felling and skidding works in declining forest stands combined with their reconstruction have been carried out. Among different species silver fir has been introduced on a large scale. In the paper the results of investigation of plants and soil carried out 7 sites located in Beskidy Mountains (49°41’6”N, 19°1’48”E) are presented. Contents of K, Mg, Ca and N in needles of silver fir (Abies alba Mill.) and leaves of bilberry (Vaccinium myrtillus L.) were determined which was accompanied by a chemical characteristics of forest topsoil from the same sites. Moreover, in both environment compartments, the concentration of S, Pb, Cd, and Zn was also determined to assess the level of anthropopression in individual sites. In general, the obtained results show relatively good mineral status of plants. Some disturbances in the ratios of elements in plants were found in sites located near the Polish and Czech border. In plants and soil in these sites an elevated level of heavy metals was found which testifies the transboundary transport of air pollutants. The bilberry seems to be a better bioindicator of heavy metal pollution than silver fir.

Trace Metal Concentrations in Pine Needles at Varying Elevation in Proximity to Roadways in an Urban Environment

Conifer needles bioaccumulate atmospheric pollutants, including trace metals, and may be used to monitor variations in atmospheric concentration. Needles were analyzed to determine whether a correlation exists between elevations and trace metal concentrations in proximity to roadways and other non-point sources. Composite samples of white spruce (Picea glauca) and balsam fir (Abies balsamea) needles were collected along hillsides in eastern and western Calgary, respectively. A combined total of 11 sites was sampled along two transects of increasing elevation. Qualitative and quantitative analysis of trace metal concentrations was completed using inductively coupled plasma-mass spectrometry (ICP-MS) and synthesized using regression analysis. The concentrations of cobalt, nickel, and calcium in the samples were found to exhibit a significant (P < 0.05) relationship with respect to elevation and proximity to roadways.

Turnover of 137Cs in ‘soil–tree’ system: An experience of measuring the isotope flows in a Siberian conifer forest

Little attention has been paid to the uptake of 137Cs in natural forests under low levels of the isotope fallout when no immediate ecological danger presents. Here we present the extended assessments of the soil-to-plant and canopy-to-litter flows of 137Cs recently evaluated in a native Siberian forested area. The area undergoes a typical after-fire long term succession, with light-conifer upper story being followed by undergrowth of Siberian fir and other dark-conifer species. The one-year-old needles of Siberian fir were found to accumulate the largest concentration of the isotope, 4.10 Bq/kg oven-dry weight during the first growth season, as compared with older needles that accumulated 4.67 Bq/kg oven-dry weight in 2–3 years of growth. Based on these data an approach was developed that, hypothetically, can allow one to estimate the 137Cs activity concentration in soil solutions. Direct activity measurements in the soil solutions were not possible. The isotope activity in soil solutions was estimated to be 0.0061–0.0105 Bq/L. Based on the original data from the litter fall the annual flow of the isotope from the upper canopy to on-ground litter was found to be 0.42–0.84 Bq/m2. The amount of 137Cs that returns yearly back from canopy with falling litter was estimated to be 0.012–0.015% of the total soil isotope content. A combination of the estimations obtained in our study with the values of global 137Cs fallout allowed us to assess the ages (the time of formation) of horizons of the soils in the area.

New polyprenyl phosphate based preparation Fortepren® as promising cytokine regulationg antiviral remedy

Fortepren®, a product of the phosphorylation of polyprenols from fir needles (with sodium polyprenyl phosphate being the main active ingredient), belongs to the class of antiviral drugs with immunomodulating activity. Fortepren® may be used as the drug of choice in the treatment of herpes diseases. It was shown that treatment with Fortepren® of patients with a chronic recurrent herpes infection after acute phase termination with acyclovir decreased the recurrence rate, as well as the severity of local symptoms. Fortepren® treatment of patients with a high incidence of recurrent herpes infection led to an increase in the interferon-producing ability of leucocytes stimulated with NDV, as well as in the production of key cytokines (IL-1β, IL-15, MIP-1α, IFN-γ, IL-12 (p40), TNF-α, IFN-α2, IL-12 (p70), IL-6) taking part in the protection against viral infection. Data suggest that the action of the drug is directed, first of all, to the cells responsible for the natural resistance of the organism (macrophages, dendritic cells, etc.). The activation of natural immunity appears to be a leading mechanism of protection from herpesviral infection under the influence of polyprenyl phosphate.

Magnesium Isotope Variations to Trace Liming Input to Terrestrial Ecosystems: A Case Study in the Vosges Mountains.

Liming with Ca and Mg carbonates is commonly used to reduce soil and stream acidity and to improve vegetation growth and nutrition in forests. Ten years ago, dolomite lime was experimentally applied to a forest catchment on granite in the Vosges Mountains (northeast France), which is characterized by acid soils and drained by an acid stream. The average Mg isotope composition of the dolomite lime (-1.75‰) was low compared with that of tree foliage (-0.70‰), granite and deep soil layers (-0.40‰), and stream water (-0.80‰) in the control catchment. After liming, the exchangeable Mg concentrations in surface soil layers, which were initially very low, increased, and the Mg isotope composition decreased (up to -0.60‰). The decrease was smaller in deeper layers but not in proportion to the increase in exchangeable Mg content, suggesting contributions from mineralization of organic matter and/or displacement of exchangeable Mg from surface layers. Before application, Mg concentration in beech and fir leaves was low, and that of 1-yr-old fir needles was lower than that in current needles. Internal Mg translocation within fir needles also resulted in a lower δMg of older needles. Three years after dolomite application, the Mg isotope composition of plant leaves was lower than that in the control catchment; this decrease (up to -1.00‰) was attributed to direct uptake of Mg from dissolving dolomite. Liming doubled the concentration of Mg in the stream, whereas the Mg isotope composition decreased correspondingly from -0.80 to -1.20‰, indicating a fast transfer of dolomite Mg to the stream. Our findings indicate that monitoring of δMg may be a promising tool to study the fate of dolomitic inputs in terrestrial and aquatic ecosystems.

Variation in needle and cone characteristics and seed germination ability of Abies bornmuelleriana and Abies equi-trojani populations from Turkey

Turkish fir (Abies bornmuelleriana Mattf.) and Trojan fir (Abies equi-trojani (Aschers. Et Sint. Ex Boiss) Mattf.) are economically and ecologically important endemic species to Turkey. These species are also becoming increasingly popular in Europe and North America due to their suitable characteristics for use as Christmas trees coupled with their pest resistance. Provenance features, as well as needle and cone characteristics and seed germination ability, of three Turkish fir and two Trojan fir populations were studied. Provenance features (vigor score, crown score, and color) and mother tree characteristics (height class, diameter at breast height, and height) were very similar between species and among populations within species. Needles of Turkish fir were significantly (P < 0.05) longer and wider than those of Trojan fir. Turkish fir also had wider cones and a higher cone width/length ratio than Trojan fir. There were moderate, positive, and significant correlations between needle-cone characteristics and location variables (elevation, latitude, and longitude). Needle size tended to increase northwards, eastwards, and upwards along an altitudinal gradient. Cone width and the cone width/length ratio showed a weak trend of increasing northwards, while the cone width also showed a weak trend of increasing eastwards. Bract and cone length were not significantly correlated with any of the location variables. The overall mean cumulative germination percentage of Turkish fir seed (57%) was significantly higher (P < 0.05) than that of Trojan fir (36%). The natural genetic resources of both species should be conserved and managed sustainably to preserve the variation in their endemic locations because of their valuable benefits to Turkey and other countries.

Assimilatory pigments from subfossil fir needles (Abies alba Mili.)

Assimilatory pigments from subfossil fir needles (Abies alba Mili.)

ГРУППОВОЙ СОСТАВ ЭКСТРАКТОВ ИЗ КРОНЫ ЛИСТВЕННИЦЫ СИБИРСКОЙ ЛЕТНЕГО И ОСЕННЕГО СБОРОВ

The results of extractive compounds contain research in the different parts of the Siberian larch crown (needles, bark, wood part of twigs) collected in summer and autumn and fallen-down needles are presented. The extractive compounds and essential oils contains extracted by organic solvents (petroleum and diethyl ethers, ethyl acetate and isopropyl alcohol) are detected. It is defined that the Siberian larch needles contain less extractive compounds (extracted by petroleum and diethyl ethers) than fir spruce needles, Scotch pine needles and Siberian fir needles, but they may be compared by isopropanol soluble extractives. The main quantity of the essential oils and extractives soluble in petroleum and diethyl ethers, ethyl acetate is detected in twig bark. Autumn collected needles and twigs extractives contain (extracted by all solvent kinds) increase, contain of essential oils is decrease.The group composition of the isopropyl alcohol extractives of all kinds of raw materials and the group composition of petroleum and diethyl ethers extracts are presented. The main part of the isopropanol extract is petroleum ether soluble fraction (lipophilic fraction). The twig bark lipophilic fraction (of the isopropanol extract) consists of free acids for 60%, twig wood part collected in summer and autumn twigs lipophilic fractions consist of free acids for 50%, the lipophilic fractions of summer needles and fallen-down needles consist of neutral compounds for 70%. The main part of diethyl ether extract (obtained from isopropanol extract) of the all kinds of raw materials consists of phenolic acids (substances which may be extracted by aqueous sodium hydrogencarbonate). Summer needles and fallen-down needles diethyl ether extracts consist of substances which may be extracted by aqueous caustic for 28% and 40%.The main content of the diethyl ether neutral compounds is detected in fallen-down needles. It is 25%.

Extraction of Maltol from Fraser Fir: A Comparison of Microwave-Assisted Extraction and Conventional Heating Protocols for the Organic Chemistry Laboratory

Two methods for the extraction of maltol from Fraser fir needles are performed and compared in this two-week experiment. A traditional benchtop extraction using dichloromethane is compared to a microwave-assisted extraction using aqueous ethanol. Students perform both procedures and weigh the merits of each technique. In doing so, students see a trade-off between the ease of working with a highly volatile organic solvent and the selectivity that can be achieved with the greener solvent combination. This experiment combines multiple lab techniques, highlights the connections between chemistry and biology, and provides straightforward 1H NMR spectra to support the introduction of spectroscopy in first-semester organic chemistry.

POLYPRENYL PHOSPHATES AS ADJUVANTS, POLARIZING THE IMMUNE RESPONSE TO Th1

Abstract. The attempts to decrease a toxic action of Freund complete adjuvant have led to development of new emulsion adjuvant compositions. More often they are based on metabolizable oil (squalene) with addition the Tween 80 (Polisorbate 80) as an emulsifier. The third component is an immunomodulator. Adjuvants, intended for prevention of virus infections, should include the immunomodulators polarizing the immune response to Th1. From this point of view adjuvant based on a colloidal solution prepared by means of the Tween 80 from polyprenyl phasphates of fir needles (Phosprenyl) can be rather perspective. The last one, as well as squalene, is constructed by isoprene links, but has them not 6, but 16 that essentially reduces its toxicity. The obtained data shows that Phosprenyl essentially enhances efficiency of vaccination in such virus infections as tick born encephalitis, bird flu, poliomyelitis and polarizes the immune response to Th1.

Heat and Mass Transfer in Quenching the Reaction of Thermal Decomposition of a Forest Combustible Material with a Group of Water Drops

We have carried out computational investigations of the processes of heat and mass transfer in quenching the reaction of thermal decomposition of the typical forest combustible materials (birch leaves and pine and fir needles) with a group of water drops. It has been established that the termination time of pyrolysis is influenced by the integral parameter characterizing the relative position of drops and the temperature of the vapor-gas mixture over the forest combustible material. The thicknesses of layers providing termination of pyrolysis of evaporated liquid materials for a group of drops have been determined.