Physical characteristics and weight relationship of Gigantochloa scortechinii (Buluh Semantan) 1-,2- and 3-year old natural stand bamboos

Physical characteristics, such as average number of internodes, internode length, culm wall thickness, circumference of internodes, and weight of culm, branch and leaf of 1-, 2- and 3-year old culms were determined. Data were gathered from 47 to 62 of 1-, 2- and 3-year old culms in Kedah, Peninsular Malaysia. Significant linear relationships between weight and solid volume of the bamboo were observed for all the various ages studied. In addition, their corresponding regression equations were also determined. The 3-year old culm had the biggest mean for all the characteristic features, except for the Diameter-breast height (Dbh) and the culm wall thickness at the base. This was followed by the 2-year old culm. Meanwhile, regression of the height and culm weight on the Dbh gave the best regression line for 1 year old culm in terms of its r-squared value of 84 and 86 percent in comparison to the 2 and 3-year old culm

The Influenced of Compression on Properties of Binderless Compressed Veneer Made from Oil Palm Trunk

Binderless compressed veneer panels from oil palm trunk consisted of 5 layers of oil palm trunk veneers were made with 3 different thickness, 7 mm, 10 mm and 15 mm. The panels were pressed at temperature of 180 °C with pressure 5 MPa at duration time of 20 minutes. The veneers were pressed without using any synthetic adhesive in the manufacturing process. Mechanical and physical properties such as flexural test, thickness swelling and water absorption, density and compression ratio were observed and evaluated based on Japanese Agricultural Standard 2003 (JAS). The findings showed that binderless compressed veneer panels that undergo pressing process with thickness bar 7 mm showed the highest value of flexural strength compared to other type of panels. Dimensional stability such as thickness swelling and water absorption showed relationship with compression ratio. Based on the results, the compression ratio did influenced the properties of binderless compressed veneer panel made from oil palm trunk

Characterization of Cellulose Microfibers Isolated from Rubberwood (Hevea brasiliensis)

Cellulose microfibers were isolated by chemical treatment followed by acid hydrolysis using sulphuric acid. The chemical compositions for extractive, holocellulose, cellulose and lignin were determined. The functional group of raw particles and cellulose microfibers of rubberwood were determined using fourier transform infrared spectroscopy (FT-IR). Morphological studies were viewed using Scanning Electron Microscopy (SEM) to investigate physical changes of the fibers after acid hydrolysis. The results show that cellulose content was increased to 63 % from 52 % after hydrolysis was conducted to the raw particles. Particle size distribution of cellulose microfibers falls in the range of below 100 µm. The removal of lignin and other extractives during chemical and acid hydrolysis can be seen by the absence of certain band in the FTIR spectra. The individualization of the fibers can be seen after hydrolysis with sulphuric acid. The removal of the surface impurities along with defibrillation were also shown in the cellulose microfibers. Cellulose microfibers were isolated by chemical treatment followed by acid hydrolysis using sulphuric acid. The chemical compositions for extractive, holocellulose, cellulose and lignin were determined. The functional group of raw particles and cellulose microfibers of rubberwood were determined using fourier transform infrared spectroscopy (FT-IR). Morphological studies were viewed using Scanning Electron Microscopy (SEM) to investigate physical changes of the fibers after acid hydrolysis. The results show that cellulose content was increased to 63 % from 52 % after hydrolysis was conducted to the raw particles. Particle size distribution of cellulose microfibers falls in the range of below 100 µm. The removal of lignin and other extractives during chemical and acid hydrolysis can be seen by the absence of certain band in the FTIR spectra. The individualization of the fibers can be seen after hydrolysis with sulphuric acid. The removal of the surface impurities along with defibrillation were also shown in the cellulose microfibers.

3β-Chloro­cholest-5-en-7-one

The title compound, C27H43ClO, is a steroid derivative composed of a saturated carbon fused-ring framework with an alkyl side chain. The A and C rings have chair conformations and the B and D rings assume half-chair conformations. The cholesterol side chain is fully extended with a gauche, trans conformation of the terminal methyl groups. In the crystal structure, the molecules are aligned in an antiparallel fashion, forming alternate layers. These layers are then linked via C—H⋯O hydrogen bonds, forming a three-dimensional network

Cholest-5-en-3β-yl N-phenyl­carbamate

In the title compound, C34H51NO2, the dihedral angle between the planes of the phenyl ring and the carbonyl group is 9.30 (2)°. No significant inter­molecular inter­actions are observed in the crystal structure. The C5H11 fragment is disordered over two positions with site occupancies of 0.611 (6) and 0.389 (6)

9-(3,4-Dimeth­oxy­phen­yl)-3,4,5,6,7,9-hexa­hydroxanthene-1,8(2H)-dione

In the title compound, C21H22O5, the mean planes of the pyran and dimeth­oxy­phenyl rings are nearly perpendicular to one another, with the dihedral angle between them being 88.21 (8)°. The pyran ring adopts a boat conformation whereas the two fused cyclo­hexane rings adopt envelope conformations. In the crystal, mol­ecules are linked into a three-dimensional network by inter­molecular C—H⋯O hydrogen bonds

The Physical and Mechanical Properties of Compreg Laminated Bamboo Strips Lumber (LBSL) of <em>G. scortechinii</em>

The chapter explores the effect of resin concentration and pre-drying time on the physical and mechanical properties of compreg-laminated bamboo strips lumber (LBSL) from G. scortechinii species. The compreg LBSL panels were manufactured using two concentrations of low-molecular-weight phenol formaldehyde (LMwPF) resin, that is, 100 and 70% at three different pre-drying times (12, 18, and 24 h). Based on the findings, the panel with 70% of LMwPF required a longer time and higher temperature to cure than the panel with 100% LMwPF. The weight percent gain (WPG) and moisture content of the panels increased in line with increasing resin concentration but decreased with increasing pre-drying time. The opposite trend is indicated by density. As for the mechanical properties, the strength of the panel increases along with the increase in resin concentration and pre-drying time. However, for high-concentration resins, prolonging the pre-drying time reduces the strength of the sample. The highest flexural strength and tensile strength were observed in the 100/18 sample with values of 260 and 27 MPa, respectively. The results for formaldehyde emissions show panels with lower resin concentrations: 70% LMwPF and prolonged pre-drying time reduce formaldehyde emission levels

Redetermination of ethyl (3a-cis)-3a,8b-dihydr­oxy-2-methyl-4-oxo-3a,8b-dihydro-4H-indeno[1,2-b]furan-3-carboxyl­ate monohydrate

The crystal structure of the title compound, C15H14O6·H2O, has been redetermined from single-crystal X-ray data. The structure was originally determined by Peet et al. [J. Heterocycl. Chem. (1995), 32, 33–41] but the atomic coordinates were not reported or deposited in the Cambridge Structural Database. The ethyl substituent is disordered over two sites with refined occupancies of 0.815 (6) and 0.185 (6). The indeno group is almost planar [maximum deviation 0.0922 (14) Å] and makes an angle of 68.81 (4)° with the furan ring. The fused ring molecules are assembled in pairs by intermolecular O—H⋯O hydrogen bonds. The resulting dimers are also hydrogen bonded to the water molecules, forming double-stranded chains running along the a axis

SYNTHESIS, CHARACTERIZATIONAND ANTIMICROBIALACTIVITYOF FRIEDELIN [2, 3-d] SElENADIAZOlE

ABSTRACT The new 1, 2, 3, selenadiazole derivative (3) was prepared from friedelin (1) via the co"esponding semicarbazone (2) using Lalezari cyclization. The compounds were prepared, separated and characterized on the basis of microanalysis and spectral studies. The isolated friedelin and its selenadiazole were screened in vitro for their antimicrobial activities against various pathogenic bacterial were found to be highly active against al/ the selected pathogens. Compound 3 showed an inhibition zone of 14 mm and 12 mm respectively against highly resistant S. albus and C. albicans. A general mechanistic scheme for these reactions is also suggested based on current and previous results