Anatomical and chemical factors affecting tensile growth stress in Eucalyptus grandis plantations at different latitudes in Brazil

2012 ◽  
Vol 42 (1) ◽  
pp. 134-140 ◽  
Author(s):  
Miho Kojima ◽  
Hiroyuki Yamamoto ◽  
Koichiro Saegusa ◽  
Fabio Minoru Yamaji ◽  
Masato Yoshida ◽  
...  
Keyword(s):  
Lignin Content ◽  
Microfibril Angle ◽  
Eucalyptus Grandis ◽  
Middle Layer ◽  
Growth Stress ◽  
Cellulose Content ◽  
Factors Affecting ◽  
Wide Range ◽  
Chemical Factors ◽  
Processing Defects

The key to using planted Eucalyptus as timber lies in controlling the characteristic high tensile growth stress that often causes serious processing defects in sawn logs and lumber. In the present study, we investigated variations in the longitudinal released strain (RS) of surface growth stress in stems of Eucalyptus grandis W. Hill ex Maiden planted in a wide range of latitudes in Brazil and established relationships between RS measurements and anatomical and chemical factors. Cellulose and lignin content, RS, and the microfibril angle (MFA) of the middle layer of the secondary wall (S2 layer) differed among latitudes. The increase in cellulose content and decrease in MFA were correlated with the contractive value of RS, which explained the higher tensile growth stress in stems from high-latitude plantations where higher cellulose content and lower MFA were observed. To reduce processing defects due to tensile growth stress, the factors controlling MFA values and cellulose content must be identified.

Negative gravitropism of Ginkgo biloba: growth stress and reaction wood formation

Holzforschung ◽  
2016 ◽  
Vol 70 (3) ◽  
pp. 267-274 ◽  
Author(s):  
Tatsuya Shirai ◽  
Hiroyuki Yamamoto ◽  
Miyuki Matsuo ◽  
Mikuri Inatsugu ◽  
Masato Yoshida ◽  
...  
Keyword(s):  
Ginkgo Biloba ◽  
Lignin Content ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Wood Formation ◽  
Growth Stress ◽  
Reaction Wood ◽  
Cellulose Content ◽  
S2 Layer ◽  
Negative Gravitropism

Abstract Ginkgo (Ginkgo biloba L.) forms thick, lignified secondary xylem in the cylindrical stem as in Pinales (commonly called conifers), although it has more phylogenetic affinity to Cycadales than to conifers. Ginkgo forms compression wood-like (CW-like) reaction wood (RW) in its inclined stem as it is the case in conifers. However, the distribution of growth stress is not yet investigated in the RW of ginkgo, and thus this tissue resulting from negative gravitropism is still waiting for closer consideration. The present study intended to fill this gap. It has been demonstrated that, indeed, ginkgo forms RW tissue on the lower side of the inclined stem, where the compressive growth stress (CGS) was generated. In the RW, the micorofibril angle in the S2 layer, the air-dried density, and the lignin content increased, whereas the cellulose content decreased. These data are quite similar to those of conifer CWs. The multiple linear regression analysis revealed that the CGS is significantly correlated by the changes in the aforementioned parameters. It can be safely concluded that the negative gravitropism of ginkgo is very similar to that of conifers.

scholarly journals Characterization of eucalyptus clones subject to wind damage

2017 ◽  
Vol 52 (11) ◽  
pp. 969-976
Author(s):  
Antônio José Vinha Zanuncio ◽  
Amélia Guimarães Carvalho ◽  
Angélica de Cassia Oliveira Carneiro ◽  
Paulina Valenzuela ◽  
William Gacitúa ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Microfibril Angle ◽  
Eucalyptus Grandis ◽  
Basic Density ◽  
Middle Lamella ◽  
Growth Stress ◽  
Wind Damage ◽  
Modulus Of Rupture ◽  
Tree Resistance

Abstract: The objective of this work was to test a new methodology to assess the resistance of trees to wind damage and determine the characteristics that increase clone resistance to winds. Tree resistance to breakage, basic density, ultrastructure, anatomy, mechanical properties, and wood growth stress have been evaluated in seven Eucalyptus grandis × Eucalyptus urophylla clones, collected from a region with a high incidence of wind damage. The Pearson correlation coefficient between the tree resistance to breakage and the ratio between the area damaged by the winds and the total planted area was -0.839, showing the efficiency of the methodology adopted and that high breaking strength results in a smaller area affected by wind damage. Trees with a high basic density, cell wall fraction, modulus of elasticity of the middle lamella and fibers, fiber hardness, modulus of rupture, growth stress and low microfibril angle and height and width of the rays showed greater resistance to wind damage. Therefore, the selection of clones with these features may reduce the incidence of damage by winds in Eucalyptus plantations.

scholarly journals Substrate-Related Factors Affecting Cellulosome-Induced Hydrolysis for Lignocellulose Valorization

2019 ◽  
Vol 20 (13) ◽  
pp. 3354 ◽  
Author(s):  
Ying Wang ◽  
Ling Leng ◽  
Md Khairul Islam ◽  
Fanghua Liu ◽  
Carol Sze Ki Lin ◽  
...  
Keyword(s):  
Lignin Content ◽  
Untreated Wood ◽  
Cellulosic Biomass ◽  
Host Cells ◽  
Lignocellulosic Substrate ◽  
Related Factors ◽  
Factors Affecting ◽  
Lignocellulosic Feedstocks ◽  
Chemical Factors ◽  
Physical And Chemical

Cellulosomes are an extracellular supramolecular multienzyme complex that can efficiently degrade cellulose and hemicelluloses in plant cell walls. The structural and unique subunit arrangement of cellulosomes can promote its adhesion to the insoluble substrates, thus providing individual microbial cells with a direct competence in the utilization of cellulosic biomass. Significant progress has been achieved in revealing the structures and functions of cellulosomes, but a knowledge gap still exists in understanding the interaction between cellulosome and lignocellulosic substrate for those derived from biorefinery pretreatment of agricultural crops. The cellulosomic saccharification of lignocellulose is affected by various substrate-related physical and chemical factors, including native (untreated) wood lignin content, the extent of lignin and xylan removal by pretreatment, lignin structure, substrate size, and of course substrate pore surface area or substrate accessibility to cellulose. Herein, we summarize the cellulosome structure, substrate-related factors, and regulatory mechanisms in the host cells. We discuss the latest advances in specific strategies of cellulosome-induced hydrolysis, which can function in the reaction kinetics and the overall progress of biorefineries based on lignocellulosic feedstocks.

scholarly journals Prediction of loblolly pine wood properties using transmittance near-infrared spectroscopy

2005 ◽  
Vol 35 (10) ◽  
pp. 2423-2431 ◽  
Author(s):  
Robert Sykes ◽  
Bailian Li ◽  
Gary Hodge ◽  
Barry Goldfarb ◽  
John Kadla ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Fiber Length ◽  
Near Infrared ◽  
Lignin Content ◽  
Nir Spectroscopy ◽  
Wood Properties ◽  
Cellulose Content ◽  
Nondestructive Technique ◽  
Wide Range ◽  
Calibration Equations

Near-infrared (NIR) spectroscopy is a rapid nondestructive technique that has been used to characterize chemical and physical properties of a wide range of materials. In this study, transmittance NIR spectra from thin wood wafers cut from increment cores were used to develop calibration models for the estimation of α-cellulose content, average fiber length, fiber coarseness, and lignin content in the laboratory. Eleven-year-old trees from two sites were sampled using 12-mm increment cores. Earlywood and latewood of ring 3 and ring 8 from these samples were analyzed in the laboratory using microanalytical methods for α-cellulose content, average fiber length, fiber coarseness, and lignin content. NIR calibrations and laboratory measurements based on one site were generally reliable, with coefficients of determination (R2) ranging from 0.54 to 0.88 for average fiber length and α-cellulose content, respectively. Predicting ring 8 properties using ring 3 calibration equations showed potential for predicting α-cellulose content and fiber coarseness, with R2 values of approximately 0.60, indicating the potential for early selection. Predicting the wood properties using the calibration equations from one site to predict another showed moderate success for α-cellulose content (R2 = 0.64) and fiber coarseness (R2 = 0.63), but predictions for fiber length were relatively poor (R2 = 0.43). Prediction of lignin content using transmittance NIR spectroscopy was not as reliable in this study, partially because of low variation in lignin content in these wood samples and large errors in measuring lignin content in the laboratory.

Study on Division of Natural Bamboo Fibers by Steam Explosion

2012 ◽  
Vol 476-478 ◽  
pp. 1873-1876
Author(s):  
Yuan Song Zhang ◽  
Ji Xiang Xie ◽  
Yu Chun Jiang
Keyword(s):  
Steam Explosion ◽  
Lignin Content ◽  
Cellulose Content ◽  
Separation Effect ◽  
Factors Affecting ◽  
Explosion Pressure ◽  
Bamboo Fibers ◽  
Better Than

In order to improve the effect of natural bamboo fibers degumming, the factors affecting the natural bamboo fibers separation effect in general alkali boiling conditions after the process of steam explosion were researched. The results showed that the degumming rate increased with the rise of steam explosion pressure and the pressure maintaining time. As the steam explosion was stronger, the degree of the fibers separation and softness were better. After steam explosion and alkali boiling united degumming method, the hemicelluloses and lignin content of the fibers decreased by 41.61% and 31.94%, while the cellulose content rose to 63.59%. The effect of steam explosion and alkali boiling united degumming method was better than single alkali boiling or steam explosion. The morphology of fibers became smooth and the fiber’s diameter reduced obviously.

Factors Affecting Molecular Self-Assembly and Its Mechanism

2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Molecular Engineering ◽  
Molecular Structures ◽  
Polymer Science ◽  
New Approach ◽  
Factors Affecting ◽  
Dna Structures ◽  
Self Assembling ◽  
Wide Range

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.

Uphoff Norman, Priti Ramamurthy, and Roy Steiner. Managing Irrigation: Analysing and Improving the Performance of Bureaucracies. New Delhi/Newbury Park/London: Sage Publications. 1991. Hardbound. Price not given.

1993 ◽  
Vol 32 (2) ◽  
pp. 226-228
Author(s):  
Zakir Hussain
Keyword(s):  
Water Distribution ◽  
Irrigation System ◽  
Irrigation Management ◽  
Performance Criterion ◽  
New Delhi ◽  
Irrigation Performance ◽  
Factors Affecting ◽  
Wide Range ◽  
Resource Mobilisation ◽  
Management Issues

The book; under review provides a valuable account of the issues and factors in managing the irrigation system, and presents a lucid and thorough discussion on the performance of the irrigation bureaucracies. It comprises two parts: the first outlines the factors affecting irrigation performance under a wide range of topics in the first five chapters. In Chapter One, the authors have attempted to assess the performance of the irrigation bureaucracies, conceptualise irrigation management issues, and build an empirical base for analysis while drawing upon the experience of ten country cases in Asia, Africa, and Latin America. The Second Chapter focuses on the variations in the management structures identified and the types of irrigation systems; and it defines the variables of the management structures. The activities and objectives of irrigation management are discussed in Chapter Three. The objectives include: greater production and productivity of irrigation projects; improved water distribution; reduction in conflicts; greater resource mobilisation and a sustained system performance. The authors also highlight the performance criterion in this chapter. They identify about six contextual factors which affect the objectives and the performance of irrigation, which are discussed in detail in Chapter Four. In Chapter Five, some organisational variables, which would lead to improvements in irrigation, are examined.

Analysis of Sound Reduction and Strong Drag Composite Concrete Fibers Gedebok Banana Results Delignification with Sodium Hydroxide Solvent (Naoh)

2018 ◽  
Vol 6 (02) ◽  
pp. 105-120
Author(s):  
Muhammad Rouf Suprayogi ◽  
Annisa Mufida ◽  
Edwin Azwar
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Lignin Content ◽  
Sound Intensity ◽  
Cellulose Fiber ◽  
Cellulose Content ◽  
Cellulose Powder ◽  
Drying Method ◽  
Normal Concrete ◽  
Sound Reduction

In composite science, desirable materials that are lighter but have the power and quality that can match or even exceed the material that has been there before. The purpose of this study was to investigate the effect of cellulose fiber addition from banana gedebok to tensile strength, compressive strength and damping of concrete composite sound. To achieve this objective, mixing of cellulose fibers with K-275 quality concrete mix with variation of 0% and 5% substitution in which the cellulose is varied in powder and wicker form. Delignification of lignin content from banana gedebok was done by soaking and drying method without any variation and yielding powder having cellulose content of 13,0388%, hemicellulose 18,2796% and lignin 0,6684%. This study produces concrete composites that have a tensile strength and a compressive strength lower than that of normal concrete. Normally reinforced concrete tensile strength value 94.5 kg / cm2, 71.4 kg / cm2 cellulose powder concrete and 90.3 kg / cm2 cellulose woven concrete. Normal concrete compressive strength value 334,22 kg / cm2, cellulose powder concrete 215,7 kg / cm2, and cellulose webbing concrete 157,98 kg / cm2. As for the power damping sound of cellulose webbing concrete has the highest damping power compared to other concrete with the absorbed sound intensity that is 52-68 dB

OCCURRENCE OF THE RISKS FOR DEVELOPMENT OF RESPIRATORY DISEASES IN CHILDREN EXPOSED TO THE CHEMICAL FACTORS OF THE EXPOSURE OF ALUMINA REFINERY- ASSOCIATED BUSINESS ACTIVITY

2019 ◽  
pp. 42-47 ◽  
Author(s):  
M.A. Zemlianova ◽  
I.V. Tikhonova
Keyword(s):  
Respiratory Tract ◽  
Respiratory Diseases ◽  
Inflammatory Diseases ◽  
Allergic Inflammation ◽  
Respiratory Morbidity ◽  
Upper Respiratory Tract ◽  
Negative Effects ◽  
Wide Range ◽  
Chemical Factors ◽  
Chronic Lymphoproliferative Diseases

Alumina refineries are among the leading sources of atmospheric air pollution with a wide range of pollutants hazardous to human respiratory organs. It is relevant to study and evaluate the occurrence of the risks for development of respiratory diseases in children living in the area affected by the emission components of an alumina refinery. We assessed air quality of the area under observation and comparison according to monitoring observations, risk of non-carcinogenic effects from the respiratory organs. The content of chemicals in the blood and urine adequate to risk factors was quantified. The structure of individual groups of respiratory diseases was analyzed. The causal relationships of violations of laboratory parameters with an increased content of chemicals in biological media were evaluated. It was found that an aerogenic exposure of chemical pollutants is formed on the territory with the production of metallurgical alumina. It determines the risk for development of respiratory diseases, exceeding an acceptable level up to 49.9 times. In the exposed children, the content of manganese, chromium, nickel, copper, xylenes, formaldehyde and aluminum, fluoride ion in the urine was increased to 4.2 times in relation to the indices in the comparison group. A high level of additional respiratory morbidity(1.8 times) was revealed. Chronic lymphoproliferative diseases of the nasopharynx and inflammatory diseases of the upper respiratory tract (up to 6.6 times more often), inflammatory diseases with a predominance of the mechanism of allergic inflammation ( up to 2.1 times more often)are more often detected in the framework of the respiratory diseases. Negative effects on the part of the respiratory system in the form of activation of antioxidant processes, the development of an inflammatory reaction, local, general and specific sensitization of the respiratory tract were established. It confirms the occurrence of the risks for the development of respiratory diseases in children in the exposure area of the chemical factors of alumina refinery-associated economic activity.

Business Aviation in Russia: Specific Features and Prospects of Development

2020 ◽  
Vol 26 (1) ◽  
pp. 86-93
Author(s):  
D. V. Slivinsky ◽  
I. A. Fomina ◽  
D. G. Menshikh
Keyword(s):  
Systems Approach ◽  
National Policy ◽  
Civil Aviation ◽  
Economic Growth Rate ◽  
Factors Affecting ◽  
Organization And Management ◽  
Transport Services ◽  
Business Aviation ◽  
Wide Range

The presented study determines the role of business aviation in the modern economy and examines the specific features of its development in Russia.Aim. The study aims to analyze the development of business aviation in Russia and its correlation with economic development in general.Tasks. The authors determine the benefits of business aviation as a business tool, examine the specific features of the Russian business aviation market and problems of its development, and identify factors that affect the development of business aviation in Russia.Methods. This study uses the methods of comparative and retrospective analysis, cross-country comparison, systems approach, and expert analytics.Results. Business aviation is a new segment of civil aviation for Russia. Therefore, it is advisable to rely on foreign practices in the management of its development. In many countries, business aviation is a separate industry that specializes in providing transport services to a wide range of corporate clients and/or individuals. The development of this industry is associated with the economic growth rate and the development level of the national economy, and also depends on the national institutional specifics. This study describes the specific features of development of business aviation in Russia and problems arising in the organization and management of this type of business.Conclusions. The authors develop a system of factors affecting the development of business aviation in Russia, describe the major problems of this industry, and propose solutions. The results of this study can be used in the development (adjustment) of business aviation development strategies in Russia both at the industrial and corporate level, and in the implementation of the national policy in this field.

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