scholarly journals Termite-repellent wood extractives

1969 ◽  
Vol 37 (3) ◽  
pp. 224-227
Author(s):  
George N. Wolcott
Keyword(s):  
Lignin Content ◽  
Chemical Constituent ◽  
Wood Extractives ◽  
Local School ◽  
Specific Chemical ◽  
East Indian ◽  
School Of Medicine ◽  
Termite Attack ◽  
Dry Wood ◽  
High Lignin Content

Neither hardness nor high lignin content of a wood prevent its being eaten by dry-wood termites. Immunity from attack of so-called termite-resistant woods is due to the presence of some specific chemical constituent, such as tectoquinone in East Indian teak, in comparatively small amounts which causes it to be toxic or unpalatable to the insects. This substance extracted from the wood may be used as an insecticide, like commercial Ryania from Ryania speciosa, or for impregnating termite-susceptible woods to make them immune to termite attack. Conrado Asenjo of the local School of Medicine is working on the extractives of West Indian mahogany.

scholarly journals The termite resistance of pinosylvin, stilbene and other new insecticides

1969 ◽  
Vol 34 (4) ◽  
pp. 338-342
Author(s):  
George N. Wolcott
Keyword(s):  
Chemical Constituents ◽  
Tectona Grandis ◽  
Natural Resistance ◽  
Chemical Analyses ◽  
The West ◽  
Specific Chemical ◽  
East Indian ◽  
Termite Attack ◽  
Dry Wood ◽  
Insect Attack

The natural resistance to termite attack of some woods has long been known, but chemical analyses, to determine the specific chemical constituents responsible, have rarely been made. Until very recently almost the only exception seems to have been in the case of East Indian teak, Tectona grandis L. The well-known resistance to weathering, decay and insect attack of teakwood is apparently due to the presence of beta-methylanthraquinone (tectoquinone). A ten minute submersion in a 1% solution in acetone of tectoquinone will indefinitely protect susceptible woods against attack by the West Indian dry-wood termite, Cryptotermes brevis Walker, (Wolcott 1946). The partly-eaten keys of a piano (of which one key had already been replaced with a duplicate made of mahogany), heavily infested with these termites, have thus been successfully protected against further injury, despite the fact that the untreated remainder of the piano is falling to pieces, so rapidly is its oak case being devoured.

scholarly journals Inherent Natural Resistance of Woods to the Attack of the West Indian Dry-Wood Termite, Cryptotermes brevis Walker

1969 ◽  
Vol 41 (4) ◽  
pp. 259-311
Author(s):  
George N. Wolcott
Keyword(s):  
New World ◽  
West Indian ◽  
Chemical Constituent ◽  
Natural Resistance ◽  
Rare Occurrence ◽  
The West ◽  
The World ◽  
Termite Attack ◽  
Dry Wood ◽  
The Tropics

Based on extensive feeding tests with nymphs of the West Indian dry-wood termite, Cryptotermes brevis Walker, on the woods of nearly 300 species of trees from all parts of the world, it would appear that inherent natural resistance to termite attack resulting from the characteristic presence and abundance in the wood of a specific repellent chemical constituent does not occur in any wood of the Temperate Zone of either the Northern or Southern Hemispheres. Such inherent natural resistance is of comparatively rare occurrence in the semi-Tropics, but has developed in a considerable number of trees of the Tropics of both the Old and the New World.

scholarly journals Chemical Variations of Thermally Modified Wild-Grown Bambusa Vulgaris Schrad.Ex J.C. Wendl from Nigeria

2022 ◽  
Vol 9 (2) ◽  
pp. 19-27
Author(s):  
Olajide O B ◽  
Ogunsanwo O Y ◽  
Aguda L O ◽  
Oriire LT
Keyword(s):  
Lignin Content ◽  
Chemical Constituents ◽  
Chemical Properties ◽  
Chemical Constituent ◽  
Chemical Characteristics ◽  
Content Increase ◽  
Bambusa Vulgaris ◽  
Time Regime ◽  
Termite Attack ◽  
C 30

Determining the variation of chemical properties of thermally treated Bambusa vulgaris is important to provide the information of the responses of the chemical constituents to the bamboo modification against biodegradation. This research was therefore conducted to determine the chemical properties of thermally modified Bambusa vulgaris. Two hundred and seventy (30 x 2 x 0.5 cm) bamboo strips dimension were thermally modified in a heat-chamber at 100, 110, 120, 130 and 140 °C each, for 10, 20 and 30 minutes, under constant pressure (220 N/m2) in factorial arrangement in completely randomised design with 5 replicates. Unmodified strips served as control. Chemical characteristics (cellulose, hemicellulose, lignin and ash contents) were determined using standard procedures. The mean variation range of the control to 140°C/30 minutes of the thermally modified samples is as follows; the cellulose value ranged from 46.46±0.11% to 42.19±0.18%, hemicellulose from 35.59±0.10% to 31.80±0.01%, lignin from 29.11±0.12% to 26.17±0.13%, ash from 0.92±0.02% to 0.63±0.01%; the study also revealed that there were decrease in each chemical constituent value varies from a lower to a higher temperature and time regime proportionally except in the lignin content. Increase in temperature and time of thermal modification reduced the chemical characteristics of Bambusa vulgaris which resulted to reduction in the level of sugar contents (cellulose) of bamboo which enables it to be less attractive to both fungi and termite attack hence extending the service life of bamboo in use.

Characterisation of Drawing Papers for Borko Lazeski’s Cartoons (1951–56)

2018 ◽  
Vol 39 (3) ◽  
pp. 157-183
Author(s):  
Maja Kostadinovska
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Nature ◽  
Lignin Content ◽  
Mural Painting ◽  
Micro Raman Spectroscopy ◽  
Different Types ◽  
Informed Treatment ◽  
Acidic Conditions ◽  
Spot Tests ◽  
High Lignin Content

Abstract This paper presents a study of the drawing papers from Borko Lazeski’s cartoons for a mural painting. The collection is comprised of more than 20 single pieces (170×500 cm) executed in charcoal, pencil, pastel, tempera and ink. The cartoons exhibit different types of damages, such as grease stains, moisture stains, cracks, flaking paint, areas of loss caused by insects and mould stains. The study included spot tests, ATR-FTIR and micro-Raman spectroscopy to characterise the artist’s papers. They were found to be a type of paper composed of partly bleached, neutral sulphite semi-chemical (NSSC) wood pulp originating from coniferous trees (softwood) with the occasional use of abaca fibres. The laboratory tests revealed slightly acidic conditions (pH=5.01–6.52), high lignin content (>5 %) and alum-rosin sizing. Infrared spectroscopy confirmed all findings of the spot tests. Micro-Raman spectroscopy showed the presence of gypsum in the papers. The study addresses conservation issues arising from the chemical nature of the paper support and highlights the need for an extended study in order to be able to make informed treatment choices.

scholarly journals Delignification of Date Palm Fronds using Modified Organosolv Technique

2017 ◽  
Vol 13 (3) ◽  
pp. 1-9
Author(s):  
Yasmeen Salih Mahdi ◽  
Asem Hassan Mohammed ◽  
Alaa Kareem Mohammed
Keyword(s):  
Date Palm ◽  
Lignin Content ◽  
Statistical Experimental Design ◽  
Digestion Time ◽  
Stainless Steel Reactor ◽  
Pre Treatment ◽  
Design Type ◽  
Palm Fronds ◽  
Central Composite ◽  
High Lignin Content

Abstract   In this study, modified organic solvent (organosolv) method was applied to remove high lignin content in the date palm fronds (type Al-Zahdi) which was taken from the Iraqi gardens. In modified organosolv, lignocellulosic material is fractionated into its constituents (lignin, cellulose and hemicellulose). In this process, solvent (organic)-water is brought into contact with the lignocellulosic biomass at high temperature, using stainless steel reactor (digester). Therefor; most of hemicellulose will remove from the biomass, while the solid residue (mainly cellulose) can be used in various industrial fields. Three variables were studied in this process: temperature, ratio of ethanol to water and digestion time. Statistical experimental design type Central Composite Design (CCD) has been used to find a mathematical relationship between the variables and the remaining lignin percent as dependent variable. The results obtained in this study were represented by a polynomial mathematical equation of the second degree.  The results showed that the best digestion time was (80 minutes), which gave the best percent remaining concentration of lignin (3%) at temperature of 185oC and ratio of ethanol: water equal to 50: 50 wt/wt. In order to reduce digesting time, the effect of using different catalysts have been studied such as (NaOH, H2SO4, Ca (OH) 2) at low concentration (0.025, 0.025, 0.05M) respectively. It was found that the best catalyst is sodium hydroxide at concentration (0.025) mol/L which gave the same percent of  lignin 3% but with low digestion time about 30 min. Keywords: Biomass pre-treatment, delignification, lignin, organosolv, date palm fronds.

Oak contribution to litter nutrient dynamics in an Appalachian forest receiving elevated nitrogen and dolomite

2009 ◽  
Vol 39 (5) ◽  
pp. 936-944 ◽  
Author(s):  
K.B. Piatek ◽  
P. Munasinghe ◽  
W.T. Peterjohn ◽  
M.B. Adams ◽  
J.R. Cumming
Keyword(s):  
Atmospheric Deposition ◽  
Nutrient Dynamics ◽  
Lignin Content ◽  
Nutrient Fluxes ◽  
Mixed Species ◽  
N Dynamics ◽  
P Flux ◽  
P Immobilization ◽  
High Lignin Content ◽  
N Flux

Ecosystem nitrogen (N), phosphorus (P), and calcium (Ca) fluxes are affected by inputs of atmospheric N. Oak litter may additionally affect these fluxes because of its high-lignin content. We analyzed nutrient dynamics in ambient mixed-species litter in an aggrading hardwood stand at the Fernow Experimental Forest in West Virginia. We separated oak from the mix for analysis (oak) and compared it with total litter (all species) to understand how oak affects nutrient fluxes in the litter layer. The study was conducted under ambient atmospheric deposition, under elevated atmospheric deposition, and under elevated deposition plus mitigation with dolomite. N flux between litterfall and 12 months later indicated a net loss in all-species litter of up to 7.3 kg N·ha–1 and a retention of up to 0.6 kg N·ha–1 in oak. P flux included losses in all species in ambient and in dolomite treatments of up to 0.19 kg P·ha–1 and gains of up to 0.12 kg P·ha–1 in oak in all treatments. Oak mineralized Ca at an average across treatments of 4.6 kg Ca·ha–1 compared with 16 kg Ca·ha–1 in all species, with half of that when trees were dormant. Percent immobilization and release over initial litter were greater in oak than in all species, but nutrient fluxes were lower in oak than in all species because of low oak litter mass. Elevated deposition lowered N and increased P immobilization. Dolomite appeared to affect early N dynamics only. With an increase in litterfall mass when forests mature, these effects are also likely to increase.

scholarly journals Precipitate obtained following membrane separation of hydrothermally pretreated rice straw liquid revealed by 2D NMR to have high lignin content

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Kengo Sasaki ◽  
Mami Okamoto ◽  
Tomokazu Shirai ◽  
Yota Tsuge ◽  
Hiroshi Teramura ◽  
...  
Keyword(s):  
Rice Straw ◽  
Membrane Separation ◽  
Lignin Content ◽  
2D Nmr ◽  
High Lignin Content

scholarly journals A Comparative Study of Microcrystalline Cellulose Isolated from the Pod Husk and Stalk of Fluted Pumpkin

2019 ◽  
pp. 1-11
Author(s):  
C. C. Nwajiobi ◽  
J. O. E. Otaigbe ◽  
O. Oriji
Keyword(s):  
Physicochemical Properties ◽  
Microcrystalline Cellulose ◽  
Lignin Content ◽  
Cellulose Derivatives ◽  
Cellulose Content ◽  
Alternative Source ◽  
Fluted Pumpkin ◽  
Hydrolysis Of ◽  
High Lignin Content ◽  
High Cellulose

Microcrystalline celluloses (MCC) were prepared from α-celluloses obtained from fluted pumpkin stalk and pod. The substrates were subjected to treatment with 2% (w/v) NaOH, 3.5% (w/v) NaOCl and 17.5% (w/v) NaOH solutions respectively to obtain alpha celluloses. Acid hydrolysis of the alpha-celluloses using 2.5 N hydrochloric acid were carried out. The study evaluates and compares the physicochemical properties of microcrystalline cellulose obtained from the pod and stalk of fluted pumpkin. Composition of cellulose, hemicellulose and lignin were also determined. Results showed cellulose; hemicellulose and lignin content of the pod husk and stalk were 49%, 26%, 9% and 41%, 24%, 26%, respectively. The morphology of the hydrolyzed MCCs’ were investigated using scanning electron microscopy (SEM) and the results revealed the stalk (FS-MCC) to have an individual rod-like shaped fiber when compared with flat-shaped large aggregated forms of the pod (FP-MCC). The particles sizes were also uneven with FP-MCC (6.689 µm) having larger particle sizes than FS-MCC (5.538 µm). The high cellulose content of the pod husk shows that the applications may be extended in the production of other cellulose derivatives while the high lignin content of the stalk reveals other alternative source of producing lignin in the making of textile dyes, coating and other agricultural chemical. Pod MCC (FP-MCC) had better physicochemical properties than the stalk MCC (FS-MCC).

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