DISPERSION OF KAOLINITE BY WATER EXTRACTS OF DOUGLAS-FIR ASH

1984 ◽  
Vol 64 (3) ◽  
pp. 439-443 ◽  
Author(s):  
PHILIP B. DURGIN ◽  
PHILIP J. VOGELSANG
Keyword(s):  
Key Words ◽  
Chemical Constituents ◽  
Douglas Fir ◽  
Specific Adsorption ◽  
Water Extracts ◽  
Inorganic Constituents

The inorganic constituents of black and gray ash from Douglas-fir slash were analyzed to evaluate the mechanism by which ash extract disperses kaolinite. Chemical constituents promoting kaolinite dispersion were anions that increase alkalinity and are specifically adsorbed, namely orthophosphate, carbonate, hydroxyl, and me-tasilicate. Key words: Fire, specific adsorption, carbonate

Shearing force of alfalfa stems: Effects of genotype and year interactions

1998 ◽  
Vol 78 (4) ◽  
pp. 719-722
Author(s):  
A. D. Iwaasa ◽  
K. A. Beauchemin ◽  
S. N. Acharya ◽  
J. G. Buchanan-Smith
Keyword(s):  
Cell Wall ◽  
Medicago Sativa ◽  
Key Words ◽  
Chemical Constituents ◽  
Stem Segment ◽  
Shearing Force ◽  
Medicago Sativa L ◽  
Genotype Clustering ◽  
Force Characteristics

Shearing force of alfalfa (Medicago sativa L.) stems was measured to evaluate genotype-by-year interactions. Based on mean shearing force for each stem segment and genotype clustering criteria, several genotypes had similarly shearing forces among years. Therefore, selecting genotypes with desirable shearing force characteristics to improve digestibility or intake potential of forages may be possible. Key words: Genotype, environment, shearing force, cell wall chemical constituents

The enhanced performance of split-ring connections through prestressing

1991 ◽  
Vol 18 (5) ◽  
pp. 830-838 ◽  
Author(s):  
J. H. P. Quenneville ◽  
K. Van Dalen
Keyword(s):  
Key Words ◽  
Engineering Design ◽  
Laboratory Study ◽  
Laboratory Tests ◽  
Simple Technique ◽  
Douglas Fir ◽  
Limit States ◽  
Split Ring ◽  
Lap Splices

This paper examines the concept of enhancing the performance of timber connectors in truss joints by the introduction of transverse prestressing. The behaviour of lap splices of Douglas fir, with 63 mm split-ring connectors and end distances of 50, 100, 150, and 210 mm, was examined for various levels of prestress in a laboratory study. As well, the magnitude of the load that can be carried by the connection through friction between faying surfaces was also assessed for various levels of prestress. The simple technique used in the laboratory for introducing prestress is described. Results of the laboratory tests on 20 joint configurations are presented, and the experimentally determined strengths are compared with the calculated resistances using the provisions of CAN\CSA-086.1-M89 "Engineering design in wood (limit states design)." Key words: timber, connector, prestress, truss joint.

scholarly journals Specific adsorption sites and conditions derived by thermal decomposition of activated carbons and adsorbed carbamazepine

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Dittmann ◽  
Paul Eisentraut ◽  
Caroline Goedecke ◽  
Yosri Wiesner ◽  
Martin Jekel ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Evolved Gas Analysis ◽  
Gas Analysis ◽  
Specific Adsorption ◽  
Adsorption Mechanisms ◽  
Adsorption Sites ◽  
Adsorption Processes ◽  
Inorganic Constituents

AbstractThe adsorption of organic micropollutants onto activated carbon is a favourable solution for the treatment of drinking water and wastewater. However, these adsorption processes are not sufficiently understood to allow for the appropriate prediction of removal processes. In this study, thermogravimetric analysis, alongside evolved gas analysis, is proposed for the characterisation of micropollutants adsorbed on activated carbon. Varying amounts of carbamazepine were adsorbed onto three different activated carbons, which were subsequently dried, and their thermal decomposition mechanisms examined. The discovery of 55 different pyrolysis products allowed differentiations to be made between specific adsorption sites and conditions. However, the same adsorption mechanisms were found for all samples, which were enhanced by inorganic constituents and oxygen containing surface groups. Furthermore, increasing the loadings led to the evolution of more hydrated decomposition products, whilst parts of the carbamazepine molecules were also integrated into the carbon structure. It was also found that the chemical composition, especially the degree of dehydration of the activated carbon, plays an important role in the adsorption of carbamazepine. Hence, it is thought that the adsorption sites may have a higher adsorption energy for specific adsorbates, when the activated carbon can then potentially increase its degree of graphitisation.

scholarly journals Cost of pruning Douglas-fir in coastal British Columbia

1994 ◽  
Vol 70 (1) ◽  
pp. 80-83
Author(s):  
S. A. Y. Omule ◽  
D. E. Paul ◽  
L. M. Darling
Keyword(s):  
British Columbia ◽  
Key Words ◽  
Travel Time ◽  
Douglas Fir ◽  
Time Study ◽  
Average Spacing ◽  
The Cost ◽  
Coastal British Columbia

Artificial pruning can increase the quantity of high-value clear lumber harvested from Douglas-fir, but the pruning cost per tree is relatively high. To prune a young Douglas-fir to 6 metres in one lift and two lifts took, respectively, 9.5 and 10.1 minutes in 14- and 18-year old stands with average spacing between trees of about 3 metres on flat or 0-30% south-facing slopes in coastal British Columbia. The associated costs were $2.09 and $2.22. This included minor travel time between trees, but excluded the cost of travelling to the site, selecting and marking trees to be pruned, and purchasing and maintaining the pruning equipment. Differences in pruning time between one-lift pruning and two-lift pruning, in one or two passes, were small. A D-handled saw was preferred to the more strenuous snap-cut pruner with ratchet-style pinions, based on observations on a pruning time-study of 5 operators. Key words: pruning saw, snap-cut pruner, pruning time, one-lift pruning, two-lift pruning

DISPERSION OF KAOLINITE BY DISSOLVED ORGANIC MATTER FROM DOUGLAS-FIR ROOTS

1984 ◽  
Vol 64 (3) ◽  
pp. 445-455 ◽  
Author(s):  
PHILIP B. DURGIN ◽  
JESSE G. CHANEY
Keyword(s):  
Organic Matter ◽  
Carboxylic Acid ◽  
Dissolved Organic Matter ◽  
Molecular Size ◽  
Douglas Fir ◽  
Specific Adsorption ◽  
Polycarboxylic Acids ◽  
Molecular Sizes ◽  
Dispersing Ability ◽  
Hydrophobic Acids

The organic constituents of water extracts from Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) roots that cause kaolinite dispersion were investigated. The dissolved organic matter was fractionated according to molecular size and chemical characteristics into acids, neutrals, and bases of the hydrophilic and hydrophobic groups. The dominant fraction causing dispersion included the hydrophobic acids and organics with molecular sizes greater than 104 nominal molecular weight. Partial oxidation of the dissolved organic matter increased its carboxylic acid content and dispersion potential. Organic acids promoting kaolinite dispersion included aliphatic and aromatic carboxylic acids. The dispersing ability of a carboxylic acid was related to its charge and charge density. Kaolinite has a pH-dependent surface charge; specific adsorption of carboxyl groups makes the clay more negative and promotes dispersion. Polycarboxylic acids appear to play the major role in kaolinite dispersion by dissolved organic matter in forests. Key words: Fulvic acid, specific adsorption, carboxylic acid, fractionation

scholarly journals 415 Fertilizer Source and Medium Composition Affect Growth of Moth Orchid

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 515D-515
Author(s):  
Yin-Tung Wang ◽  
Elise A. Konow
Keyword(s):  
Leaf Area ◽  
Douglas Fir ◽  
Medium Composition ◽  
The Other ◽  
Fresh Weight ◽  
Liquid Fertilizer ◽  
Water Extracts ◽  
Moth Orchid ◽  
N Source ◽  
P Concentration

Vegetatively propagated Phalaenopsis Atien Kaala `TSC 22' plants 10 cm in leaf spread were potted in a medium that consisted of either 100% fine grade Douglas fir bark or a mixture of 70% fir bark and 30% sphagnum peat. Plants were fertigated at each irrigation with 10N-13.1P-16.6K (10-30-20), 20N-2.2P-15.8K (20-5-19), 20N-8.6P-16.6K (20-20-20), or a 2N-0.4P-1.7K (2-1-2) liquid fertilizer at a common N rate of 200 mg•L-1. After 1 year in a greenhouse, plants grown in the bark/peat medium produced more leaves and had heavier fresh weights and larger total leaf areas than those in 100% bark. In the bark medium, the 20N-2.2P-15.8K fertilizer resulted in best plants, despite its low P concentration (22 mg•L-1). When grown in bark/peat, the two fertilizers (20N-2.2P-15.8K and 20N-8.6P-16.6K) containing urea as part of their N source (10% and 52%, respectively) resulted in plants with 40% to 50% heavier shoot fresh weight and 40% larger leaf area than the other fertilizers. With any given fertilizer, plants had similar root weights in both media. Media and fertilizers had limited or no effect on the concentrations of minerals in the second mature acropital leaves except P, the concentration of which nearly doubled in leaves of plants grown in 100% bark. Water extracts from the bark/peat medium had lower pH, higher EC, and elevated levels of NH4-N, Ca, Fe, Na, Cl, B, and Al than those from 100% bark. Exacts from the bark medium did not have detectable levels of NO3-N, whereas extracts from the bark/peat medium all had similar levels of NO3-N, regardless of which fertilizer was applied.

scholarly journals Water Quality of Major Ponds of Comilla Town

1970 ◽  
Vol 45 (1) ◽  
pp. 57-62
Author(s):  
SZKM Shamsad ◽  
Md Didar-Ul-Alam ◽  
ASM Shamsuddoha ◽  
Mohammad Naushad Alam
Keyword(s):  
Water Quality ◽  
Community Health ◽  
Key Words ◽  
Water Samples ◽  
Chemical Constituents ◽  
Chemical Properties ◽  
Organic Wastes ◽  
Dry Period ◽  
Physico Chemical

Some important physico-chemical properties of water of major ponds of Comilla Town were studied to evaluate the water quality. Eight water samples were collected during the dry period (March 2005) from eight major ponds of Comilla Town (Ranir dighi, Mandir dighi, Nanuar dighi, Fauzdari dighi, Modina dighi, Dargabari dighi, Darma Sagar and Thakurpara). The result revealed that all the chemical constituents, except a few, are beyond the recommended limit for different uses. Higher value of pH (at Dargabari dighi, Darma Sagar dighi), OM (at Thakurpara dighi, Fauzdari dighi and Modina dighi), NH4+ concentration (at Ranir dighi, Mandir Dighi, Fauzdari dighi, Modina dighi and Dargabari dighi), and lower value of DO (at Fauzdari dighi and Modina dighi) may due to continuous disposal of kitchen wastes, organic wastes, sewage running and fall of twigs as well as extensive used for bathing, washing cloths and utensils etc. All indicate eutrophication and affect community health and hygiene and also create aesthetic problem in the locality. Key words: Ponds; Comilla District; Water quality Eutrophication DOI: 10.3329/bjsir.v45i1.5184 Bangladesh J. Sci. Ind. Res. 45(1), 57-62, 2010

scholarly journals Chemical Constituents of Essential Oil from Anethum sowa L. Herb (Leaf and Stem) Growing in Bangladesh

2010 ◽  
Vol 45 (2) ◽  
pp. 173-176 ◽  
Author(s):  
M Moshfekus Saleh-e-In ◽  
Abida Sultana ◽  
Mozaffar Husain ◽  
Sudhangshu Kumar Roy
Keyword(s):  
Essential Oil ◽  
Key Words ◽  
Chemical Constituents ◽  
Distillation Method ◽  
Anethum Sowa

The oil obtained by the hydro-distillation method from the fresh leaves and stems of Anethum sowa L. (Dill) herb was analyzed by GC-MS. Twenty compounds were isolated and identified. The major constituents were apiole (25.39%), o-cymene (15.25%), α-thujene (14.84%), β-phellandrene (7.17%), 6,6-dimethyl-2-(3-oxobutyl) bicyclo(3.1.1) heptan-3-one (6.90%), exo-2-hydroxycineol (5.03%), limonene (4.13%), 3-isopropyl-4-methyl-1-pentyn-3-ol (2.89%), myristicine (2.46%) and dihydroumbellulone (2.14%). Key words: Anethum sowa L.; Essential oil; GC-MS; Apiole DOI: 10.3329/bjsir.v45i2.5721Bangladesh J. Sci. Ind. Res. 45(2), 173-176, 2010

Standards for evaluating taper estimating systems

1993 ◽  
Vol 69 (4) ◽  
pp. 438-444 ◽  
Author(s):  
A. Kozak ◽  
J. H. G. Smith
Keyword(s):  
Key Words ◽  
Forest Inventory ◽  
Variable Exponent ◽  
Douglas Fir ◽  
Variable Form

Four taper-estimating systems were evaluated for coastal Douglas-fir to demonstrate statistical and practical considerations that should be used when selecting a taper-estimating system for forest inventory purposes. The four equations compared were: Max and Burkhart's (1976) segmented polynomial, Newnham's (1988) variable-form, Ormerod's (1986) diameter-point and Kozak's (1988) variable-exponent equation. Key words: Taper, segmented polynomial, variable-form, diameter-point, variable exponent, coastal Douglas-fir

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