scholarly journals Impact of Steaming Mode on Chemical Characteristics and Colour of Birch Wood

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 478 ◽  
Author(s):  
Anton Geffert ◽  
Jarmila Geffertová ◽  
Eva Výbohová ◽  
Michal Dudiak
Keyword(s):  
Saturated Steam ◽  
Chemical Components ◽  
Chemical Characteristics ◽  
Birch Wood ◽  
Oxidation Reactions ◽  
Mode Iii ◽  
Dehydration Reactions ◽  
Extractive Substances ◽  
Quantitative Changes ◽  
Guaiacyl Lignin

The aim of this work was to evaluate the changes of the chemical components in birch wood (Betula pendula Roth) caused by steaming with saturated steam at three temperatures—105 °C, 125 °C and 135 °C. In the samples of the original wood and wood after steaming, select chemical characteristics were determined, and wood, isolated holocellulose and Seiferts’s cellulose were analysed by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The greatest changes in the birch wood characteristics were observed in steaming mode III (135 °C). The differential spectra of the birch wood samples indicated that the hemicelluloses were significantly degraded and that the dehydration reactions were able to proceed. A clear increase in both unconjugated and conjugated carbonyls was seen only in mode III. The findings also confirmed the greater sensitivity of the guaiacyl lignin contained in broadleaves to elevated steaming temperatures, as well as the course of the thermal oxidation reactions and the formation of new carboxyls in mode III. The decrease in the ratio of absorbances H 1732/2900 and H 1243/2900 demonstrated the cleavage of acyl (acetyl and formyl) groups from birch wood hemicelluloses. The qualitative and quantitative changes of the hemicelluloses and extractive substances in birch wood during steaming were well-correlated with the measured pH values and wood colour.

scholarly journals Sensorial, Melissopalynological and Physico-Chemical Characteristics of Honey from Babors Kabylia’s Region (Algeria)

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 225
Author(s):  
Asma Ghorab ◽  
María Shantal Rodríguez-Flores ◽  
Rifka Nakib ◽  
Olga Escuredo ◽  
Latifa Haderbache ◽  
...  
Keyword(s):  
Sensory Properties ◽  
Chemical Components ◽  
Chemical Characteristics ◽  
Pollen Spectrum ◽  
Botanical Origin ◽  
Flavonoid Content ◽  
Chemical Parameters ◽  
High Tendency ◽  
Physico Chemical ◽  
Pollen Types

This study aimed to characterize the honeys of Babors Kabylia through sensory, melissopalynological and physico-chemical parameters. Thirty samples of honey produced in this region were collected over a period of two years and analyzed. All the samples presented physico-chemical parameters in conformity with legislation on honey quality, with few exceptions, linked mainly to beekeeping management. The pollen spectrum revealed a great diversity with 96 pollen types. The main pollen types were spontaneous species as Fabaceae (Hedysarum, Trifolium, Genisteae plants), Asteraceae plants, Ericaceae (Erica arborea L.) or Myrtus and Pistacia. The sensory properties of samples showed a high tendency to crystallization, the colors were from white to brown, but most of them had gold color. Smell and odor corresponded mainly to vegetal and fruity families and in taste perceptions besides sweetness highlighted sourness and saltiness notes. Seventeen samples were polyfloral, one was from honeydew and twelve were monofloral from heather, genista plants, sulla, blackberry or Asteraceae. Heather and the honeydew samples showed the darkest color, the highest electrical conductivity and phenol and flavonoid content. A statistical analysis based on the most representative pollen types, sensory properties and some physico-chemical components allowed the differentiation of honey samples in terms of botanical origin.

scholarly journals Heat-Induced Discoloration of Chromophore Structures in Eucalyptus Lignin

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1686 ◽  
Author(s):  
Peng Zhang ◽  
Yanxia Wei ◽  
Yang Liu ◽  
Jianmin Gao ◽  
Yao Chen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photoelectron Spectroscopy ◽  
Eucalyptus Grandis ◽  
Gel Permeation Chromatography ◽  
Magic Angle Spinning ◽  
Saturated Steam ◽  
Magic Angle ◽  
13C Cpmas Nmr ◽  
Eucalyptus Wood ◽  
Dehydration Reactions

The color changes corresponding to chromophore structures in lignin caused by exposure of Eucalyptus (Eucalyptus grandis and E. urophylla) to heat were investigated. Eucalyptus wood powders were heat treated under saturated steam atmospheres for 10 h at 110 °C, 130 °C and 150 °C. The lignin was isolated before and after heat treatment. The physicochemical properties of the lignin and changes in chromophore structures during heat treatment was evaluated through wet chemical analysis, Fourier transform infrared spectroscopy (FTIR), diffuse reflectance ultraviolet-visible spectroscopy (DRUV-Vis), gel permeation chromatography (GPC), X-ray photoelectron spectroscopy (XPS) and 13C Cross polarization magic angle spinning nuclear magnetic resonance (13C CPMAS NMR). Wood color darkened and reddened with the increase in pressure and temperature. Depolymerization and dehydration reactions occurred via demethoxylation with heat treatment in saturated steam at 110 °C or 130 °C. Lignin condensed to form insoluble compounds after heat treatment in saturated steam at 150 °C. G units increased and S units decreased through demethylation during heat treatment, as revealed by FTIR and 13C-NMR analysis.

scholarly journals Chemical characteristics of snow in the region along the Sea of Japan

1993 ◽  
Vol 18 ◽  
pp. 227-233 ◽  
Author(s):  
Kazuhide Satow
Keyword(s):  
Spatial Distribution ◽  
Electric Conductivity ◽  
Sea Of Japan ◽  
Ph Value ◽  
Chemical Components ◽  
Chemical Characteristics ◽  
The Sea Of Japan ◽  
Heavy Snowfall ◽  
Asian Continent ◽  
Ph Values

The amount of acidity in precipitation has been measured in heavy-snowfall regions facing the Sea of Japan. The average pH value of precipitation measured throughout the year at Nagaoka was 4.80 during 4.5 years, 1987–92. During winter the pH value is lower and electric conductivity higher. The spatial distribution of chemical components in new-fallen snow was studied along a 55 km-long sampling route. Results from four surveys showed that acidic snows have average pH values of 4.63–4.90. From the distribution of anion and cation concentration in new-fallen snow, it is concluded that strong northwest monsoons during winter bring an abundance of snow with salt components and many non-salt components from the Sea of Japan and also, possibly, from the Asian continent.

scholarly journals Effect of Thermal Treatment of Birch Wood by Saturated Water Vapor on Granulometric Composition of Chips from Sawing and Milling Processes from the Point of View of Its Processing to Composites

2020 ◽  
Vol 10 (21) ◽  
pp. 7545 ◽  
Author(s):  
Richard Kminiak ◽  
Kazimierz A. Orlowski ◽  
Ladislav Dzurenda ◽  
Daniel Chuchala ◽  
Adrián Banski
Keyword(s):  
Composite Materials ◽  
Milling Process ◽  
Point Of View ◽  
Cnc Machining ◽  
Three Dimensions ◽  
Raw Material ◽  
Saturated Steam ◽  
Birch Wood ◽  
Environmental Criteria ◽  
The Impact

The goal of this work is to investigate the impact of thermal modification of birch wood with saturated steam on the particle size distribution of the sawing and milling process. Birch wood (Betula pendula Roth) is an excellent source to produce plywood boards. Wastes from mechanical processing of birch wood are suitable to produce composite materials. Granulometric analyses of chips from sawing processes on the PRW 15M frame saw, as well as on the 5-axis CNC machining centre SCM TECH Z5 and the 5-axis CNC machining centre AX320 Pinnacle, proved that more than 95% of chips are chips of coarse and medium coarse chip fractions with dimensions above 0.125 mm. Depending on the shape, coarse and medium-thick chips belong to the group of fiber chips, the length of which is several times greater than the width and thickness. Fine fractions with dimensions smaller than 125 μm are isometric chips that are approximately the same size in all three dimensions. Thoracic dust fractions below 30 μm were not measured. The performed analyses showed that the heat treatment of birch wood with saturated steam did not affect the grain size of chips formed in sawing and milling processes on CNC machining centre and can be used as a raw material for the production of composite materials. Fabric filters are suitable for separating chips extracted from frame saws, PRW-15M or machining centre. Environmental criteria for the separation of chips from transport air in textile filters are met by filters with a fabric classified in class G4.

scholarly journals Physical and Chemical Characteristics of Oil Palm Plantation Soil: A New Lead in Forensic Investigation

2021 ◽  
Vol 19 (01) ◽  
pp. 97-105
Author(s):  
RUS DINA RUS DIN ◽  
SERI MIRIANTI ISHAR ◽  
HEMANANTHINI NAGANATHAN
Keyword(s):  
Particle Size ◽  
Soil Sample ◽  
Soil Ph ◽  
Oil Palm ◽  
Reference Sample ◽  
Chemical Components ◽  
Chemical Characteristics ◽  
Forensic Investigation ◽  
Physical And Chemical Characteristics ◽  
Physical And Chemical

Soil sample is one of the important evidence that can be found in crime scene. Unknown soil sample can be analysed and compared with reference sample in order to determine the origin as its physical and chemical components possess unique characteristics. The purpose of this study is to determine the physical and chemical characteristics of soil from oil palm plantations in Perak, Malaysia to assist forensic investigation. Total of 97 topsoil samples were collected from three different oil palm plantations in Perak. Particle size distribution was obtained using dry sieving technique and colour of soil sample was examined under three conditions that are dry, moist and ashed. Soil pH was measured using pH meter and percentage of composition of soil organic matter (SOM) was determined by weighing the sample before and after ignition. Result showed that the composition of particle size <0.18mm was within the range of 5.57-21.11% whereas for particle size between 0.18mm - 0.6mm was within 31.62 - 52.96% and 25.78-66.86% for particle size >0.6mm. The color mode of soil after oven dried, moistened and ashed was greyish brown (10YR 5/2), very dark greyish brown (10YR 3/2) and light yellowish brown (10YR 6/4) respectively. Soil pH was in the range of 5.79 – 6.70. The percentage of SOM was between 3.29 - 20.48%. The physical and chemical characteristics of soil analysed in this study from three different locations of oil palm plantations varied and it is possible to discriminate these locations based on the analysis highlighted in this study.

scholarly journals Chemical characteristics of Falcataria moluccana wood infested by Boktor stem borer (Xystrocera festiva)

2021 ◽  
Vol 22 (10) ◽  
Author(s):  
NOOR FARIKHAH HANEDA ◽  
ASEP HENDRA SUPRIATNA ◽  
HASYYATI SHABRINA ◽  
Yunik Istikorini ◽  
Ulfah J Siregar ◽  
...  
Keyword(s):  
Digestive System ◽  
Lignin Content ◽  
Early Period ◽  
Stem Borer ◽  
Chemical Components ◽  
Chemical Characteristics ◽  
Healthy Tree ◽  
Age Related ◽  
Standard Procedures ◽  
Old Trees

Abstract. Haneda NF, Supriatna AH, Shabrina H, Istikorini Y, Siregar UJ, Wahyudi I. 2021. Chemical characteristics of Falcataria moluccana wood infested by Boktor stem borer (Xystrocera festiva). Biodiversitas 22: 4203-4208. Boktor (Xystrocera festiva Thoms.) is the most destructive and detrimental pest in Falcata plantations in Indonesia. It attacks the inner bark of sapwood when the tree reaches 3-years-old. This study aimed to analyze the chemical characteristics of Falcata woods, which were infested with Boktor in trees aged 3 and 4 years, compared to the healthy tree at 2 years old. The primary chemical components and type of extractive compounds were analyzed using standard procedures. The results showed a decrease in hemicellulose and an increase in lignin content of infected wood. This condition occurs because Boktor larvae prefer hemicellulose rather than lignin, which is related to the presence of enzymes in the digestive system of the larvae. The decreasing extractive contents as trees grow and undergo age-related shifting metabolism can be alleged as the start of Boktor infestation in 3-years-old trees. Boktor infestation also altering the wood chemical components by degrading the lignin that produced 4-vinyl-syringol. The isoeugenol compound is thought to prevent Boktor infestation in the early period of tree growth.

scholarly journals Chemical characteristics of snow in the region along the Sea of Japan

1993 ◽  
Vol 18 ◽  
pp. 227-233 ◽  
Author(s):  
Kazuhide Satow
Keyword(s):  
Spatial Distribution ◽  
Electric Conductivity ◽  
Sea Of Japan ◽  
Ph Value ◽  
Chemical Components ◽  
Chemical Characteristics ◽  
The Sea Of Japan ◽  
Heavy Snowfall ◽  
Asian Continent ◽  
Ph Values

The amount of acidity in precipitation has been measured in heavy-snowfall regions facing the Sea of Japan. The average pH value of precipitation measured throughout the year at Nagaoka was 4.80 during 4.5 years, 1987–92. During winter the pH value is lower and electric conductivity higher. The spatial distribution of chemical components in new-fallen snow was studied along a 55 km-long sampling route. Results from four surveys showed that acidic snows have average pH values of 4.63–4.90. From the distribution of anion and cation concentration in new-fallen snow, it is concluded that strong northwest monsoons during winter bring an abundance of snow with salt components and many non-salt components from the Sea of Japan and also, possibly, from the Asian continent.

scholarly journals Hardness of Densified Wood in Relation to Changed Chemical Composition

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 506 ◽  
Author(s):  
Przemysław Mania ◽  
Miłosz Wróblewski ◽  
Adam Wójciak ◽  
Edward Roszyk ◽  
Waldemar Moliński
Keyword(s):  
Chemical Composition ◽  
Cell Walls ◽  
Lignin Content ◽  
Densified Wood ◽  
Chemical Components ◽  
Poplar Wood ◽  
Birch Wood ◽  
Partial Reduction ◽  
Structural Components ◽  
Before And After

The aim of this study was to evaluate some of the properties of densified poplar and birch wood earlier subjected to partial delignification of cell walls. The effects of delignification are presented as a comparison of the content of basic structural components in wood before and after chemical modification. In birch wood, the lignin content decreased by 20%, while that of cellulose decreased by 9.7% and that of hemicellulose decreased by 64.9%. In poplar, the lignin content decreased by 34.1%, that of cellulose decreaed by 13.5%, and that of hemicellulose decreased by 58.0%. The hardness of densified birch and poplar wood, after partial reduction of chemical components, was 147 and 111 MPa, respectively, and, compared with natural (non-densified) wood, was almost 4.5 times and 7 times higher, respectively. Poplar wood was more densified (without delignification 238% and after delignification 281%). In the case of birch wood, the density levels were 176% and 188%, respectively.

Sign in / Sign up

Export Citation Format

Share Document