Abstract: Sunflower stalks were analysed for chemical
compositions: pentosan 15.84%, holocellulose 70.69%,
alphacellulose 45.74%, glucose 27.10% and xylose 7.69% based on
dry weight of 100-g raw material. The most optimum condition for
steam explosion pretreatment was as follows. Sunflower stalks were
cut into small pieces and soaked in 0.02 M H2SO4 for overnight.
After that, they were steam exploded at 207 C and 21 kg/cm2 for 3
minutes to fractionate cellulose, hemicellulose and lignin. The
resulting hydrolysate, containing hemicellulose, and cellulose pulp
contained xylose sugar at 2.53% and 7.00%, respectively.The pulp
was further subjected to enzymatic saccharification at 50 C, pH 4.8 citrate buffer) with pulp/buffer 6% (w/w)and Celluclast 1.5L/pulp
2.67% (w/w) to obtain single glucose with maximum yield 11.97%.
After fixed-bed fermentation under optimum condition using
conventional yeast mixtures to produce bioethanol, it indicated
maximum ethanol yield of 0.028 g/100 g sunflower stalk.
Abstract: A macroscopic constitutive equation is developed for a high-density cellulose insulation material with emphasis on the outof- plane stress relaxation behavior. A hypothesis is proposed where the total stress is additively composed by an out-of-plane visco-elastic isotropic contribution and an in-plane elastic orthotropic response. The theory is validated against out-of-plane stress relaxation, compressive experiments and in-plane tensile hysteresis, respectively. For large scale finite element simulations, the presented model provides a balance between simplicity and capturing the materials constitutive behaviour.
Abstract: In this study, single nozzle method used for
electrospinning technique which composite polymer solution with
cellulose nanowiskers (CNW) was treated by ultrasonic sonificator
have been compared with coaxial (double) nozzle method, in terms of
mechanical, thermal and morphological properties of composite
nanofiber. The effect of water content in composite polymer solution
on properties of nanofiber has also been examined. It has been seen
that single nozzle method which polymer solution does not contain
water has better results than that of coaxial method, in terms of
mechanical, thermal and morphological properties of nanofiber.
However, it is necessary to make an optimization study on setting
condition of ultrasonic treatment to get better dispersion of CNW in
composite nanofiber and to get better mechanical and thermal
Abstract: The possibility of using cassava residue containing
49.66% starch, 21.47% cellulose, 12.97% hemicellulose, and 21.86%
lignin as a raw material to produce glucose using enzymatic
hydrolysis was investigated. In the experiment, each reactor
contained the cassava residue, bacteria cells, and production medium.
The effects of particles size (40 mesh and 60 mesh) and strains of
bacteria (A002 and M015) isolated from Thai higher termites,
Microcerotermes sp., on the glucose concentration at 37°C were
focused. High performance liquid chromatography (HPLC) with a
refractive index detector was used to determine the quantity of
glucose. The maximum glucose concentration obtained at 37°C using
strain A002 and 60 mesh of the cassava residue was 1.51 g/L at 10 h.
Abstract: The spiral angle of the elementary cellulose fibril in
the wood cell wall, often called microfibril angle, (MFA). Microfibril
angle in hardwood is one of the key determinants of solid timber
performance due to its strong influence on the stiffness, strength,
shrinkage, swelling, thermal-dynamics mechanical properties and
dimensional stability of wood. Variation of MFA (degree) in the S2
layer of the cell walls among Acacia mangium trees was determined
using small-angle X-ray scattering (SAXS). The length and
orientation of the microfibrils of the cell walls in the irradiated
volume of the thin samples are measured using SAXS and optical
microscope for 3D surface measurement. The undetermined
parameters in the analysis are the MFA, (M) and the standard
deviation (σФ) of the intensity distribution arising from the wandering
of the fibril orientation about the mean value. Nine separate pairs of
values are determined for nine different values of the angle of the
incidence of the X-ray beam relative to the normal to the radial
direction in the sample. The results show good agreement. The
curve distribution of scattered intensity for the real cell wall structure
is compared with that calculated with that assembly of rectangular
cells with the same ratio of transverse to radial cell wall length. It is
demonstrated that for β = 45°, the peaks in the curve intensity
distribution for the real and the rectangular cells coincide. If this
peak position is Ф45, then the MFA can be determined from the
relation M = tan-1 (tan Ф45 / cos 45°), which is precise for rectangular
cells. It was found that 92.93% of the variation of MFA can be
attributed to the distance from pith to bark. Here we shall present our
results of the MFA in the cell wall with respect to its shape, structure
and the distance from pith to park as an important fast check and yet
accurate towards the quality of wood, its uses and application.
Abstract: Over a million tonnes of cigarette butts (CBs) are produced worldwide annually. These CBs accumulate in the environment due to the poor biodegradability of the cellulose acetate filters and pose a serious environmental risk. This paper presents some of the results from a continuing study on recycling CBs into fired clay bricks. Properties including compressive strength, flexural strength, density, water absorption and thermal conductivity of fired clay bricks are reported and discussed. Furthermore, leaching of heavy metals from the manufactured clay bricks was tested. The results show that the density of fired bricks was reduced by about 8 – 30 %, depending on the percentage of CBs incorporated into the raw materials. The compressive strength of bricks tested was 12.57, 5.22 and 3.00 MPa for 2.5, 5.0 and 10 % CB content respectively. Water absorption and initial rate of absorption values increased as density, and hence porosity, of bricks decreased with increasing CB volume. The leaching test results revealed trace amounts of heavy metals.