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Characterization of Bacterial Cellulose From Oil Palm Shoot Juices and Coconut Juice/Poly(ethylene glycol) Biocomposite
No full textA new biocomposite was preformed between bacterial cellulose (BC) pellicle and polyethylene glycol (PEG) at different concentrations (0%, 5, 10%, 15% and 20%) and different molecular weight (600, 1000 and 2000). The structure and mechanical properties of BC/PEG biocomposite were investigated. The results indicated that the properties of the BC were improved by the addition of PEG. The morphology of the BC and BC/PEG blend was examined by a scanning electron microscope (SEM). These showed that PEG was coated with a large pore size fibril on the BC and the BC/PEG was dense with an even and smooth surface. All the Fourier transform infrared spectroscopy (FT-IR) thermograms of BC/PEG showed the same functional groups as typical BC and PEG. The DSC result showed that the thermal stability improved which might be associated with a weak interaction between BC and PEG, and may be useful for applications
Feasibility of Using Wood Chips to Regulate Relative Humidity Inside a Building: A Numerical Study
No full textThe use of bio-based materials in buildings has become more and more significant last years. In most of the cases, their health properties and natural provenance have made them a great solution to face global climate warming and the new policies to reduce building energy consumption. In many thermal problems, bio-based materials can allow to optimize the building thermal behavior according to its energy consumption and inside comfort conditions. So it is when they are used as an insulation material in the building. However, it is not the case in this paper. In fact, the bio-based matter is rather used as a desiccant wheel to control air conditioning inside the building.
The aim of this paper is to numerically verify if it is possible to use a bed of wood chips as a hygroscopic material (or a desiccant matter) in order to modify the relative humidity inside the building in Reunion Island and so improve thermal comfort. A simple model of heat and mass transfer between a bed of wood chips and building inside air has been set up and implemented into a validated building simulation code named ISOLAB.
Numerical simulations were set up for the four climate zones of the island regulations and a focus has been made on the low altitude one (with high, solar irradiation, temperature and relative humidity).
Simulation results give the thermal behavior of the building particularly the temperature and relative humidity of inside air temperature, and temperature and moisture content of wood chips. The obtained results lead to determine if the wood chips bed is suitable for the reference building and to verify its technical feasibility (wood species, size of the bed, integration to the building, etc.). The results show that the use of a WCB help to decrease the building inside air temperature and water content up to 10°C less and 11.6 g.kg-1 less. These are the ways to improve inside comfort conditions.
Indeed, comfort analysis have shown the possibility to significantly increase building users’ thermal comfort when coupled with a fan and natural ventilation, like the regulation needs for low altitude climate. In this case, a gain of 68% of year time is achieved for a building equipped with WCB system compared to one without it (6308 hours of comfort over a year with the WCB against 350 hours without WCB). So the WCB seems to be able to help reducing cooling loads in tropical climate conditions
Numerical Modelling of the Transient Hygroscopic Behavior of Flax-Epoxy Composite
No full textThis contribution deals with the development of a three-node triangular plane finite element to analyze the transient hygroscopic behavior of 2/2 twill flax fabric-reinforced epoxy composite. Several plates of this material were fabricated using the vacuum infusion process and composite specimens were then cut and aged in tap water at room temperature until saturation. To simplify, a plane modelling of water diffusion in the aged specimens is adopted and Fick’s model is used to describe the water diffusion kinetics. To highlight the heterogeneity of the flax-epoxy samples, the twill flax fabrics waviness is modelled with a sinusoidal undulation. In particular, we show that the proposed finite element formulation allows estimating the flax fiber radial diffusion coefficient by an inverse approach
Non-Aligned Stagnation Point Flow of a Casson Fluid Past a Stretching Sheet in a Doubly Stratified Medium
No full textThis paper investigates the problem of oblique hydro magnetic stagnation point flow of an electrically conducting Casson fluid over stretching sheet embedded in a doubly stratified medium in the presence of thermal radiation and heat source/absorption with first order chemical reaction. It is assumed that the fluid impinges on the wall obliquely. Similarity variables were used to convert the partial differential equations to ordinary differential equations. The transformed ordinary differential equations are solved numerically using Runge-Kutta-Fehlberg method with shooting technique. It is observed that a boundary layer is formed when the stretching velocity of the surface is less than the in viscid free stream velocity at a point decreases with increase in the nonNewtonian rheology parameter. The augmentation of the temperature is observed with the magnetic parameter, heat source parameter and thermal radiation parameter while a reverse effect with thermal stratification number, Prandtl number and the velocity ratio parameter. Influence of Skin friction coefficient, Nusselt number and Sherwood number on the flow configurations for different values of pertinent parameters are portrayed graphically and discussed. Numerical results are compared with the published results and are found to be in good agreement with previously published results as special cases of present problem. The mass concentration is seen to be decrease with Schmidt number, chemical reaction parameter and solutal stratification number
Growth and production characters of elymus cylindricus in different shortening heading time
No full textRamet modules in a certain population differ in terms
of functions, which accounts for different contributions of the same
ramets. Shortening heading time brings about different contributions
of such modules. Ramets heading one after another were treated as a
continuum in respective cohorts of Elymus cylindricus aged two. The
reproductive ramets that head earlier were marked with tags every
four days during the whole heading stage from the beginning to the
end, after which all the labeled ramets at the maturity period were
gathered. The results showed that, the height and biomass of ramets,
the length and biomass of inflorescences, percentage of inflorescence
length to ramet height, percentage of inflorescence biomass to
ramet biomass, the number and biomass of seeds, seed-setting rate,
and percentage of seed biomass to ramet biomass declined with
the increasing intensity of heading time shortening as displayed
with linear or quadratic function. Ramet characteristics weakened
remarkably when shortened heading time added up to 17 days. The
biomass distribution in relation to inflorescence and seed maintain
a stable rate at the early heading stage and dwindled quickly at
the near-end stage, but the biomass of ramets remain constant
throughout the entire heading stage. The ramets with earlier heading
time make greater contribution to the survival of population
than the shortened heading time in this species of bunchgrass
Interaction of IL-22/IL-22R1 promotes cell proliferation and suppresses apoptosis of colorectal cancer via phosphorylation of STAT3
No full textInterleukin-22 (IL-22) is a member of IL-10 cytokine family which is expressed in activated T cells
predominantly and in activated natural killer cells at lower levels. Previous studies have demonstrated the link between
elevated levels of IL-22 and disease severity of psoriasis, Crohn’s disease, rheumatoid arthritis and interstitial lung
diseases. However, the function of IL-22 in the development and progression of colorectal cancer (CRC) remains
elusive. In this study, we first evaluated the IL-22/IL-22R1 level in CRC patients, and found that tumor tissues
have more active expression of IL-22 and IL-22R1 than normal tissues, presenting correlation with the degree of
differentiation of tumor tissues. Subsequently, Caspase and cell viability assays were performed on SW-480 cell line
which expresses high level of IL-22R1 to examine if the supplementation of IL-22 has an impact on apoptosis and
proliferation. In comparison with treatment of 5-FU, supplementation of IL-22 promoted cell proliferation and
ameliorated apoptosis. To unveil signal transduction upon activation of IL-22R, we examined the phosphorylation
of STAT3 in SW-480 cell line following supplementation of IL-22. The treatment of IL-22 also increased the level of
p-Akt, an essential component in PI3K/Akt pathway. Although the link between STAT3 phosphorylation and PI3K/
Akt activation remains to be explored, our study revealed the mechanism underlying the effects of IL-22R activation on
apoptosis as well as tumor differentiation, indicating the prognostic value of IL-22/IL-22R
Utilization of Multi-Tasking Non-Edible Plants for Phytoremediation and Bioenergy Source-A Review
No full textHeavy metal contamination of land and freshwater resources is a serious concern worldwide. It adversely affects the health of animals, plants and humans. Therefore, remediation of toxic heavy metals must be highly considered. Unlike other techniques, phytoremediation is a holistic technology and can be used in large scale for soil remediation as it is costless, novel, environmentally-safe and solar-driven technology. Utilization of non-edible plants in phytoremediation is an ingenious technique as they are used to generate new bioenergy resources along with the remediation of contaminated soils. Some nonfood bioenergy crops such as Salix species, Miscanthus species, Populus species, Eucalyptus species, and Ricinus communis exhibit high capability to accumulate various metals and to grow in contaminated lands. However, there are still sustainable challenges facing coupling phytoremediation with bioenergy production from polluted lands. Therefore, there has long been a need for developing different strategies to resolve such challenges. In this article review, we will discuss the phytoremediation mechanism, the technique of phytoremediation coupling with bioenergy production, sustainable problems facing linking phytoremediation with energy production as well as possible strategies to enhance the efficiency of bioenergy plants for soil decontamination by improving their characteristics such as metal uptake, transport, accumulation, and tolerance
Down-regulation of Halr1 during induced differentiation of embryonal carcinoma P19 cells
No full textMaintenance of pluripotency depends to diverse regulatory factors. Studies in embryonic stem cells
(ESCs) have indicated that large intergenic non-coding RNAs (lincRNAs) are involved in the regulatory network
of pluripotency. However, the presence and function of pluripotency-associated lincRNAs in cancer cells with
pluripotency features are unknown. In this study, we used embryonal carcinoma (EC) P19 cell lines to investigate the
expression level of Halr1 in pluripotency and retinoic acid (RA)-induced differentiated states. Down-regulation of
pluripotency associated factors such as OCT4, NANOG, SSEA1 and alkaline phosphatase at transcript and protein
levels were used to confirm the differentiated status of P19 cells. Quantitative measurement of Halr1 transcript levels
revealed a 79% decrease during RA-induced differentiation of P19 cells. These results indicate that upon exiting the
pluripotency state the expression level of Halr1 similar to core pluripotency factors is remarkably reduced
Improvement of Flat Surfaces Quality of Aluminum Alloy 6061-O By a Proposed Trajectory of Ball Burnishing Tool
No full textBurnishing is a profitable process of surface finishing due to its ability to be automated, which makes burnishing method more desirable than other finishing methods. To obtain high surface finish, non-stop operation is required for CNC machine and we can attain that by choosing a suitable trajectory of the finishing tool. In other words, burnishing paths should be multidirectional rather than monotonic, in order to cover uniformly the surface. Indeed, the burnishing force is also a key parameter of the burnishing process because it determines the degree of plastic deformation, and that makes determining the optimum burnishing force an essential step of the burnishing process a success. Therefore, we consider the strategy of ball burnishing path and the burnishing force as variable parameters in this study. In this paper, we propose a new strategy of burnishing tool path with trochoid cycles that achieves a multidirectional burnishing of the surface according to various patterns. Taking into consideration the optimum burnishing force, to improve flat surface finish of AL6061-O samples by reducing the surface roughness parameter (Rz). Experiments carried out on 3-axis milling machine show that the proposed trochoidal path is more effective than the conventional one
Texture Feature Extraction Method for Ground Nephogram Based on Contourlet and the Power Spectrum Analysis Algorithm
No full textIt is important to extract texture feature from the ground-base cloud image for cloud type automatic detection. In this paper, a new method is presented to capture the contour edge, texture and geometric structure of cloud images by using Contourlet and the power spectrum analysis algorithm. More abundant texture information is extracted. Cloud images can be obtained a multiscale and multidirection decomposition. The coefficient matrix from Contourlet transform of ground nephogram is calculated. The energy, mean and variance characteristics calculated from coefficient matrix are composed of the feature information. The frequency information of the data series from the feature vector values is obtained by the power spectrum analysis. Then Support Vector Machines (SVM) classifier is used to classify according to the frequency information of the trend graph of data series. It is shown that altocumulus and stratus with different texture frequencies can be effectively recognized and further subdivided the types of clouds