The addition of coconut fiber decreases again the strength of concrete with coconut shell, 46% to 55% of the compressive strength and 60% to 71% of the tensile strength of conventional concrete were only attained. The decrease in the mechanical properties of the concrete was opposed to the expected increase in strength when fiber was included. The decreased may be due to the fixed percentage of 3% that is greater than the optimum percentage of additional fiber of 0.5% to 2.0% that was discussed earlier in the previous
The green line illustrates the sequences of weight change, which indicates that the temperature at which the weight loos begins, and the material starts to decompose or react. The sample stated to decompose and volatilize at around 450 °C and the most polymer content fully decomposed before 600 °C. The blue line shows the number of thermal events taking place in the sample testing and as well indicates the point of greatest rate of change on weight loss curve. The red line indicates the remaining fillers and the percentage of carbon black on material. Many examples of TGA thermograms are displayed in appendix part such as material at constant temperature, multiple transformation peaks and the position of carbon
It is chemically resistant to alkalis, both dilute and concentrated, and to salt solution, although it is more sensitive to acidic materials than are cellulose esters. Ethyl cellulose is subject to oxidative degradation in the presence of sunlight or UV light at elevated temperature. This may be prevented by the use of antioxidant and chemical additives that absorb light in the range 230-340 nm range. Ethyl cellulose should be stored at a temperature not exceeding 320C (900F) in a dry area away from all sources of heat. It should not be stored next to peroxide or other oxidizing
2005a). The increase of sugar yields by proper selection and optimization of the pretreatment operation can also impact the effectiveness and cost of the other process conversion steps. Pretreatment is found to directly affect the amount and types of enzymes required to further saccharify all plant cell wall structural carbohydrates to monomeric sugars, as some pretreatment approaches are able to hydrolyze virtually all of the hemicellulose directly to monomeric xylose while other pretreatment approaches largely leave the hemicellulose intact, or only achieve partial hydrolysis to oligomeric sugars (Mosier et al. 2005a). The type and severity of the pretreatment process can also affect the amount, type and concentration of potential inhibitory compounds that can be released in soluble form directly from the biomass itself (such as acetic acid from acetylated hemicellulose or phenolics or other organic compounds released from lignin) or those produced as products from sugar degradation reactions (such as aldehydes and organic acids most commonly associated with dilute acid pretreatment).
The compound forms colloids when dissolved in water. Although non-toxic, it is combustible and can react vigorously with oxidising agents.  Hypromellose in an aqueous solution, unlike methylcellulose, it does not exhibit thermal gelation property. That is, when the solution heats up to a critical temperature, the solution congeals into a non-flowable but semi-flexible mass. Typically, this critical (congealing) temperature is inversely related to both the solution concentration of HPMC and the concentration of the methoxy group within the HPMC molecule (which in turn depends on both the degree of substitution of the methoxy group and the molar substitution.
Lignocellulose is one of the most important components of plant biomass. It comprises of approximately 50% of plant matter as a result of photosynthesis and is a plentiful resource found in soil. Lignocellulose is comprised of three plant polymers, these are; cellulose, hemicellulose and lignin, all of which are inter-chemically bonded through covalent and non-covalent linkages. Only a small amounts produced as by-products in agricultural practices for example are utilized, the large remainder is waste. Lignocellulosic residues from plants, agricultural, forestry and municipal wastes are abundant in the environment and can be utilized for biomass conversion.
It is the fibrous material found in between the hard shell and the outer covering coconut. There are two types of coconut husks, white husks from immature coconuts and brown husks from matured coconuts. Coconut husk contains cellulose, hemi-cellulose and lignin. (Majid, n.d). Coconut husks are available in large quantities as residue from the coconut production in many area, thus yielding numerous coarse husk fibres, which is seed-hair fibre obtained from the outer shell of the coconut.
The moisture content of coke depends on the quenching process: wet quenching uses water while dry cooling uses cold air. The latter method improves the strength indices (M40 & M10) of coke to some extent and is widely asserted that it is practice in Japan. The moisture makes the small particles adhere to the large lump of cokes, which may falsify the results of sieve analysis and essentially the M10 index. Moisture content is one among the many variables affecting the bulk density of coal blend and thus controlling the coke quality and yield. Increase in moisture reduces coal grindability, coking pressure and
While carbon fibre composites have a high strength to weight ratio, they are highly susceptible to high loads over a small area, such as an impact. Once the integrity of the composite is compromised, the matrix essentially starts to crumble and must be repaired or replaced. Above are two photos that show the construction of Carbon fiber. On the left are cross-linking resins, and on the right are Carbon fiber sheets layered on top of oneanother. Right now the layering is pretty basic, however, there are rumors about other lightweight self-healing materials such as kevlar and polymer.
For native cellulose, the swelling can be take place between or within the cellulose chain. We called it as interfibriling and intercrystalline. Interfibrilling caused by intercrystalline swelling in the crystalline region. Then, Intercrystalline caused by the swelling of intracrystalline in amorphous region. Likewise, alkali is not able to dissolve cellulose but it only can depolymerized into smaller fragments.