scholarly journals Direct Method of Measuring the pH Value of Wood

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 852 ◽  
Author(s):  
Anton Geffert ◽  
Jarmila Geffertova ◽  
Michal Dudiak
Keyword(s):  
Wood Surface ◽  
Cold Water ◽  
Ph Value ◽  
Direct Method ◽  
Water Extract ◽  
Free Water ◽  
Accurate Method ◽  
Hot Water ◽  
Contact Method ◽  
Wood Extraction

A direct method of measuring the pH value of wood substance is proposed in the paper. The achieved results were completed by determining the pH value on the wood surface using the contact method. Moreover, the results were compared to the results achieved using the indirect methods to determine the pH value in cold water, as well as hot water, extract of wood. Using the direct method for measuring the pH value in drilled fresh sawdust, the pH value of beech was 5.11, of birch was 5.29, of alder was 4.88, and of maple was 4.65. Following the achieved results, the possibility to measure the pH value using a fast, accurate method useful in practice complying with the condition of the minimum free water in wood (moisture content of wood above the fibre saturation point) was presented. The results of measurements of the pH value using the contact method on the wood surface showed that this method can be used in the case of coniferous as well as broadleaved trees with heartwood. The value of pH measured on the surface of pine was 4.50, of spruce was 4.79, of the heartwood of oak was 3.46, and of the sapwood of oak 5.04. The measurement of pH values of water extracts confirmed great dependence of measured values on the conditions of wood extraction.

scholarly journals Bonding of Selected Hardwoods with PVAc Adhesive

2020 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Ján Iždinský ◽  
Ladislav Reinprecht ◽  
Ján Sedliačik ◽  
Jozef Kúdela ◽  
Viera Kučerová
Keyword(s):  
Adhesion Strength ◽  
Cold Water ◽  
Ph Value ◽  
Water Extract ◽  
Solid Wood ◽  
Contact Angles ◽  
Water Contact ◽  
Ph Values ◽  
Positive Tendency ◽  
The Impact

The bonding of wood with assembly adhesives is crucial for manufacturing wood composites, such as solid wood panels, glulam, furniture parts, and sport and musical instruments. This work investigates 13 hardwoods—bangkirai, beech, black locust, bubinga, ipé, iroko, maçaranduba, meranti, oak, palisander, sapelli, wengé and zebrano—and analyzes the impact of their selected structural and physical characteristics (e.g., the density, cold water extract, pH value, roughness, and wettability) on the adhesion strength with the polyvinyl acetate (PVAc) adhesive Multibond SK8. The adhesion strength of the bonded hardwoods, determined by the standard EN 205, ranged in the dry state from 9.5 MPa to 17.2 MPa, from 0.6 MPa to 2.6 MPa in the wet state, and from 8.5 MPa to 19.2 MPa in the reconditioned state. The adhesion strength in the dry state of the bonded hardwoods was not influenced by their cold water extracts, pH values, or roughness parallel with the grain. On the contrary, the adhesion strength was significantly with positive tendency influenced by their higher densities, lower roughness parameters perpendicular to the grain, and lower water contact angles.

Comparative Analysis on Chemical Composition and Charcoal Characterization of Two Miscanthus Species

2011 ◽  
Vol 415-417 ◽  
pp. 1265-1272
Author(s):  
Wen Biao Zhang ◽  
Wen Zhu Li ◽  
Bing Song Zheng
Keyword(s):  
Chemical Composition ◽  
Specific Surface ◽  
Water Content ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ph Value ◽  
Perennial Grass ◽  
Water Extract ◽  
Carbonization Temperature ◽  
Hot Water

Miscanthus is a highly productive, rhizomatous, C4 perennial grass that should be considered as an excellent active carbon precursor. This paper compares the charcoal characterization and chemical composition between M. sinensis and M. floridulus. Species differed in water content, hot water extract, 1% NaOH extract, organic solvent extract, cellulose, lignin and ash. Carbonization temperatures have effects on charcoal yields of Miscanthus, which ranged from 23.5% to 48.0% for M. sinensis and 11.3% to 37.2% for M. floridulus. Water content, charcoal density, pH value, and specific surface area of charcoal characterization varied between two species of Miscanthus. The specific surface area increased with the increase of carbonization temperature. The highest specific surface area of M. sinensis and M. floridulus was 351.74 m2g−1and 352.74 m2g−1, respectively, when the carbonization temperature was 800°C.

scholarly journals Antibacterial activity of ginger extracts and its essential oil on some of pathogenic bacteria

2010 ◽  
Vol 7 (3) ◽  
pp. 1159-1165
Author(s):  
Baghdad Science Journal
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Pathogenic Bacteria ◽  
Cold Water ◽  
Water Extract ◽  
Ethanolic Extract ◽  
Hot Water ◽  
Diffusion Method ◽  
Resistant Bacteria

The antimicrobial activity of ginger extracts ( cold-water, hot-water, ethanolic and essential oil ) against some of pathogenic bacteria ( Escherichia coli , Salmonella sp , Klebsiella sp , Serratia marcescens, Vibrio cholerae , Staphylococcus aureus , Streptococcus sp) was investigated using Disc diffusion method , and the results were compared with the antimicrobial activity of 12 antibiotics on the same bacteria . The results showed that the ginger extracts were more effective on gram-positive bacteria than gram-negative . V. cholerae and S. marcescens,were the most resistant bacteria to the extracts used , while highest inhibition was noticed against Streptococcus sp (28 mm) . The ethanolic extract showed the broadest antibacterial activity ( 11 to 28 mm ) , in comparison with moderate activity of essential oil , it was observed that the cold-water extract was more effective on the bacteria than hot-water extract . Ginger ethanolic extract presented higher diameter of inhibition zone for Streptococcus sp than in Ciprofloxacin , Cefotaxime , Cefalotin , Cephalexin and Cephaloridine , also it was found a similarity between the higher inhibition zones of ethanolic extract of ginger and some antibiotics for S. aureus , E. coli , Salmonella sp and Klebsiella sp . V. cholerae and S. marcescens,also highly resistant to antibiotics . Phytochemical analysis of ethanolic extract of ginger revealed the present of glycosides, terpenoids, flavonids and phenolic compounds

Study on the Chemical Properties of Anthocephalus chinensis

2012 ◽  
Vol 518-523 ◽  
pp. 5366-5370
Author(s):  
Jin Sun ◽  
Xiao Bo Wang ◽  
Yuan Zhu ◽  
Xiao Jing Wang ◽  
Zhen Zhong Gao
Keyword(s):  
Chemical Composition ◽  
Sodium Hydroxide ◽  
Cold Water ◽  
Ph Value ◽  
Chemical Properties ◽  
Hot Water ◽  
Interior Decoration ◽  
Alcohol Benzene

In order to provide necessary basis for utilization of Anthocephalus chinensis, its chemical composition was explored in this paper. The results as follow: Cold water extractive is 3.18%. Hot water extractive is 4.58%. 1% sodium hydroxide extractive is 18.78%. Alcohol-benzene extractive is 2.73%. Content of cellulose is 44.09%. Content of acid-insoluble lignin is 23.31%.Content of holocellulose is 74.72%. Content of hemicellulose is 30.67%. pH value of wood is 5.31. Through comparing with other species, the results suggested that A. chinensis is ideal material for wood-based panel, interior decoration and packaging.

Study on the Chemical Properties of Toona Ciliate

2011 ◽  
Vol 94-96 ◽  
pp. 759-763
Author(s):  
Zhen Zhong Gao ◽  
Yuan Zhu ◽  
Xiao Jing Wang ◽  
Yan Lin ◽  
Xiao Bo Wang ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Sodium Hydroxide ◽  
Cold Water ◽  
Ph Value ◽  
Chemical Properties ◽  
Hot Water ◽  
Timber Species ◽  
Subtropical Region ◽  
Fast Growing ◽  
Toona Ciliata

Toona ciliata, fast-growing timber species, located in the tropical and subtropical region. In order to explore how to make better use of Toona ciliate, its chemical composition was investigated in this paper. The results show that: Cold water extractive was 1.02%. Hot water extractive was 3.39%. 1% sodium hydroxide extractive was 15.45%. Ethanol-benzene extractive was 1.53%. Content of cellulose was 48.35%. Content of acid-insoluble lignin was 24.92%. Content of holocellulose was 76.45%. Content of hemicellulose was 28.1%. pH value of wood was 6.33. Through comparing with other species, high content of cellulose and low content of extractive suggested that Toona ciliate was ideal material for pulping and board making.

scholarly journals Assessment of Cosmeceutical Potentials of Selected Mushroom Fruitbody Extracts Through Evaluation of Antioxidant, Anti-Hyaluronidase and Anti-Tyrosinase Activity

J ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 329-342
Author(s):  
Dang Lelamurni Abd Razak ◽  
Anisah Jamaluddin ◽  
Nur Yuhasliza Abd Rashid ◽  
Nor Ajila Sani ◽  
Musaalbakri Abdul Manan
Keyword(s):  
Cold Water ◽  
Schizophyllum Commune ◽  
Radical Scavenging ◽  
Water Extract ◽  
Antioxidant Property ◽  
Tyrosinase Activity ◽  
Hot Water ◽  
Scavenging Activity ◽  
Hyaluronidase Activity ◽  
Hot Water Extract

Cosmeceutical formulations containing naturally derived active ingredients are currently preferred by consumers worldwide. Mushrooms are one of the potential sources for cosmeceutical ingredients but relevant research is still lacking. In this study, hot- and cold-water extractions were performed on four locally-cultivated mushrooms—Pleurotus ostreatus, Ganoderma lucidum, Auricularia polytricha and Schizophyllum commune—with the aim to assess the cosmeceutical potential of these mushroom fruitbody extracts. Total phenolics, polysaccharide and glucan content were determined. Antioxidant property of the mushroom extracts was assessed by determining the DPPH radical scavenging, ferric-reducing (FRAP) and superoxide anion (SOA) scavenging activity. Anti-hyaluronidase activity was used as an indicator for the anti-aging and anti-inflammatory property, while anti-tyrosinase activity was evaluated to assess the anti-pigmentation or whitening property of these extracts. Our results showed that total polysaccharide content of P. ostreatus extracts was the highest (235.8–253.6 mg GE/g extract), while extracts from G. lucidum contained the lowest glucan (10.12–10.67%). Cold-water extract from S. commune exhibited substantial tyrosinase inhibition activity (98.15%) and SOA scavenging activity (94.82%). The greatest hyaluronidase activity was exhibited by G. lucidum hot-water extract, with the value of 72.78%. The findings from the correlation analyses suggest that the cosmeceutical properties of these mushrooms can be attributed mainly to the combination of different types of compound such as polysaccharides and phenolics. Overall, cold-water extract of S. commune and hot-water extract of G. lucidum showed the best results and may be further investigated.

Structural investigation of water-hyacinth (Eichhornia crassipes) polysaccharides. Part I. Water-soluble polysaccharides

1988 ◽  
Vol 66 (11) ◽  
pp. 2777-2781 ◽  
Author(s):  
Mohamady A. Issa
Keyword(s):  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Structural Investigation ◽  
Main Chain ◽  
Cold Water ◽  
Water Extract ◽  
Water Soluble ◽  
Hot Water ◽  
Side Chains ◽  
Hot Water Extract

A galactomannan and a branched (1 → 3)-β-D-glucan were isolated from the water hyacinth plant. The galactomannan, purified from the cold water extract, is composed of D-galactose and D-mannose in a ratio of 1.0:2.8. It has a (1 → 4)-linked D-mannose backbone, one out of three D-mannose residues being substituted with a single α-D-galactosyl unit. The branched (1 → 3)-β-D-glucan isolated from the hot water extract has a main chain composed of β-(1 → 3)-linked D-glucopyranosyl residues, and two single β(1 → 6)-D-glucopyranosyl groups attached as side chains to, on average, every 5 sugar units of the main chain. In addition, the branching of the β-glucan occurs regularly at O-6 of the β-(1 → 3)-linked backbone.

Antioxidant Properties of Glossogyne tenuifolia

2006 ◽  
Vol 34 (04) ◽  
pp. 707-720 ◽  
Author(s):  
Joan-Hwa Yang ◽  
Shu-Yao Tsai ◽  
Ching-Mei Han ◽  
Chun-Chien Shih ◽  
Jeng-Leun Mau
Keyword(s):  
Cold Water ◽  
Antioxidant Properties ◽  
Water Extract ◽  
Hot Water ◽  
Butylated Hydroxyanisole ◽  
Ferrous Ions ◽  
Water Extracts ◽  
Hot Water Extract ◽  
Ethanolic Extracts ◽  
Glossogyne Tenuifolia

Glossogyne tenuifolia (Labill) Cass. (Compositae) is a special medicinal plant in the Pescadores Islands. Ethanolic, cold and hot water extracts were prepared from the dried herb and their antioxidant properties and components were studied. Ascorbic acid, α-tocopherol, butylated hydroxyanisole, citric and ethylenediaminetetraacetic acids were used in assays for comparison. With regard to EC50 values in antioxidant activity, ethanolic and hot water extracts (0.08 and 0.09 mg/ml) were much more effective than the cold water extract (0.76 mg/ml). At 1.0 mg/ml, reducing capacities were 1.57, 0.31 and 1.04 for ethanolic, cold water and hot water extracts, respectively. Scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl radicals were in descending order: ethanolic > cold water > hot water extracts. At 20 mg/ml, the hot water extract chelated all hydroxyl ions (100%) whereas the scavenging ability of the cold water extract was 68.86%. Chelating abilities on ferrous ions were in descending order: cold water > hot water > ethanolic extracts. Phenols were found to be the major antioxidant components. All EC50 values were below 20 mg/ml, and some even below 0.1 mg/ml, indicating that all three extracts from G. tenuifolia were rich in antioxidant properties.

scholarly journals Comparative Efficacy of Aloe vera (Linn) and Aloe schweinfurthii (Baker) Powdered Leaf Extracts in the Control of Some Plant Fungal Pathogens

2019 ◽  
pp. 1-9
Author(s):  
A. O. Alejo ◽  
A. M. Ajayi ◽  
B. O. Akinyele
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Cold Water ◽  
Aloe Vera ◽  
Water Extract ◽  
Antimicrobial Activities ◽  
Hot Water ◽  
Colletotrichum Lindemuthianum ◽  
Leaf Extracts ◽  
Hot Water Extract

Evaluation of the relative efficacy of powdered leaf extracts of Aloe vera (Linn) and Aloe schweinfurthii (Baker) in the control of some plant pathogens was undertaken in this work. Antimicrobial activities of the extracts obtained using cold water, hot water and ethanol were tested against four fungal spp., namely, Alternaria solani, Colletotrichum lindemuthianum, Sclerotium rolfsii and Trichophyton rubrum. The phytochemical screening of the leaf extracts of the two aloe species revealed the presence of bioactive compounds such as alkaloids, tannins, saponins, flavonoids, cardiac glycosides, phytates and oxalates. The extracts were observed to exhibit varying inhibitory effects on the selected fungi. Ethanolic extract of A. vera at 50 mg/ml and 100 mg/ml had the greatest impact on A. solani and C. lindemuthianum respectively. Similarly, cold water extract of A. schweinfurthii at 100 mg/ml was the most effective against S. rolfsii and T. rubrum. However, hot water extract of A. vera was least effective against C. lindemuthianum. Also, the efficacy of cold water extract of A. schweinfurthii at 50 mg/ml was very low against T. rubrum and A. solani. The hot water extract of A. schweinfurthii at 20 mg/ml also showed the least effect against S. rolfsii. Consequently, extracts from both Aloe species can be recommended in the management of the four fungal pathogens evaluated in this study. It is hoped that in no distant future, botanical fungicides would be developed from the two Aloe species.

scholarly journals Annona muricata: Comparative Assessment of the Antibacterial Activities of the Leaf and Stem Extracts against Multiple Antibiotic Resistant Clinical Isolates

2020 ◽  
pp. 12-21
Author(s):  
O. O. Agunloye ◽  
A. K. Onifade
Keyword(s):  
Antibacterial Effect ◽  
Cold Water ◽  
Water Extract ◽  
Antibacterial Activities ◽  
Hot Water ◽  
Annona Muricata ◽  
Antibiotic Resistant ◽  
Crude Extracts ◽  
Hot Water Extract ◽  
Zones Of Inhibition

This study was conducted to determine the antibacterial effect of crude extracts of Annona muricata, comparing the leaf and stem bark extracts using the same extraction solvents. The bacteria isolates were obtained from the hospital. The isolates obtained are Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis and Streptococcus pyogene; they were confirmed using standard techniques. Multiple antibiotic-resistant was confirmed in the isolates after antibiotic susceptibility testing. Extracts were prepared from the leaf and stem of A. muricata using ethanol, chloroform, cold water and hot water. The antibacterial activities of the crude extracts were assayed using the agar well diffusion method. The phytochemical screening revealed the presence of saponins, Tannins and flavonoid especially in the ethanol extracts of both leaf and stem part of the plant. All the extract showed varying degrees of antibacterial activities. Chloroform and Hot water rated best for antibacterial activities in this study. A. muricata stem hot water extract has zones of inhibition that ranges from 16.003 ± 0.009 mm to 1.000± 0.006 mm. A. muricata leaf hot water extract has antibacterial effect with zones ranging from 14.500± 0.009 mm to 1.000± 0.006 mm across the isolates. Cold water extracts recorded the lowest zones of inhibition from this study for the stem and Bark antibacterial activities. The stem of A. muricata has higher inhibitory effect on the test isolates compared to the leaf of      A. muricata.

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