Papers by Keyword: Camphor

Abstract: Investment casting process has been a widely used process for centuries. It is known for its ability to produce components of complex shapes with dimensional accuracy and excellent surface finish. Investment casting has been used to make manufacture weapons, jewellery and art castings during the ancient civilization and today it is used to manufacture engineering components. In Investment casting wax patterns are made by wax injection and then coating of the wax patterns are done by ceramic slurry, made with silica flour and binder. After dewaxing and firing molten metal is poured in the shell and solidified casting can be achieved. Investment casting can be cast any ferrous and non ferrous metal which is difficult in die casting. Finishing operations are negligible and very thin sections as.75mm can also be cast which is not possible in sand casting but there are many challenges in Investment casting. It is relatively slow process because preparation of ceramic shell consumes a lot of time, permeability of shell is very low which causes gas permeability. Incorporation of chills is very difficult. Among all these challenges gas porosity is main problem because of poor permeability, entrapment of gases due to complex geometry of the shell, reuse of scrap metal. In the present work porosity of the shell can be increase by addition of mixture of Camphor and needle coke. After firing of the shell camphor and needle coke will be burnt leaving pores for the escape of entrapped gases. Mechanical properties of the both shell will be compared with each other.

Abstract: This paper deals with the economic and efficient way to generate electicity. Many may think this method will not be feasible. But once this is executed electricity will be generated very easily. When comparing with other fuels the quantity required may be high but it is ecofriendly and economic. Moreover camphor is bio degradable and can be prepared artificially in lab also.

Abstract: Amorphous carbon (a-C) thin films have been prepared by a simple thermal CVD using camphor oil as precursor. The effects of argon gas flow rate on electrical, optical and structural properties of a-C thin films have been investigated. The a-C thin films were characterized by using current-voltage (I-V) measurement, UV-Vis-NIR spectroscopy, Raman and FTIR spectroscopy. The I-V study reveals that the electrical conductivity was increased with increasing argon gas flow rate. It was found that the optical band gap decreased from 0.88 to 0.42 eV as gas flow rate increased which indicates a microstructural disorder at different gas flow rate. Raman and FTIR studies reveal the amorphous structures which consist of a mixture of sp² and sp³ bonded carbon atoms.

Abstract: Natural rubber (NR) has the distinguished film forming and hydrophobic properties. If it could be reformed by an addition of some pore forming agents, the porous topography of this produced material would be interesting for applying in controlled release system. The purpose of this study is to investigate on characterization of film coat and release of propranolol hydrochloride (P) from capsules coated with NR latex. The experimental methods involved the preparation of NR film which was optimally prepared by dipping technique followed by drying onto hard gelatin capsule. The drug release was determined for coated systems fabricated with two different techniques (the dissolving of sodium bicarbonate and the sublimation of ammonium carbonate or camphor). It indicated that ammonium carbonate was incompatible with NR latex. The extent of overall in vitro release of P into HCl buffer pH 1.2 from plain NR film coated capsule at 8 h was approximately 1%. However, the decrease concentration of NR latex or addition of sodium bicarbonate or camphor could enhance the extent of drug release. Scanning electron microscopy (SEM) exhibited the micro porous nature for systems loaded with sodium bicarbonate or camphor. Therefore the hydrophobic nature of NR was proper for sustainable drug release which an incorporation of some poring agent could modulate the release of active compounds.

Abstract: The knowledge of fabrication method plays an important role in the preparation of aligned carbon nanotubes (ACNT) from natural hydrocarbon feedstock. Here ACNT were successfully synthesized by two-stage catalytic chemical vapor deposition method using organic oil (camphor oil) as a precursor. Synthesis was carried out at a fixed growth temperature of 800 °C and in different growth time: 10, 20, 30, 40, 50 and 60 minutes. The optimized condition for the growth of ACNT produced a small amount of by-product amorphous carbon and highly uniform crystal structure. The experimental results demonstrated that formation ACNT is also dependent on the growth time. The nanotubes were characterized by field emission scanning electron microscopy and micro-Raman spectroscopy. Thermal properties were evaluated by thermogravimetric analysis.

Abstract: The liquid eutectic system comprising 1:1 menthol:camphor was selected to use as solvent due to it was lowest viscosity. Both menthol and camphor used in this eutectic system have been reported for their many pharmaceutical used. Various polymers were tested for their solubility in this eutectic system. Eudragit® EPO showed the highest solubility. Eudragit® EPO was the one of biocompatible polymer which could dissolve in this eutectic system up to 40% w/w with no chemical interaction of each compound. Viscosity of this system showed the exponential curve as a function of polymer concentration but all concentration showed the newtonian rheology. The pH and surface tension were slightly affected by type and amount of polymers. The obtained polymeric eutectic mixture should control the drug release for pharmaceutical applications.

Abstract: Eutectic system is a mixture or solution which the ingredients solidify or liquefy simultaneously. A eutectic mixture is therefore that unique composition of two (or more) components that has the lower crystallization temperature or melting point. This aim of this study was to prepare and characterize the eutectic systems containing menthol, borneol, camphor and N-Ethyl-5-methyl-2-(1-methylethyl) cyclohexanecarboxamide (WS-3). Menthol is able to form liquid eutectic at room temperature with camphor in the ratio of 8:2, 7:3, 6:4 and 5:5 whereas menthol and borneol in the ratio of 8:2 and 7:3, menthol and WS-3 in the ratio of 6:4 and 1:1. The rheology behavior of all liquid eutectic systems was Newtonian flow which the surface tension was in the range of 28-29 mN/m. From contact angle measurement, all liquid eutectic systems were categorized as high wettability to the glass plate. The suitable liquid eutectic system for further application as liquid carrier for injectable active compounds was 1:1 menthol:camphor because of its lowest viscosity. IR spectra indicated that there was no chemical interaction of these two materials in the selected liquid eutectic mixture.

Abstract: Crack universally existing underground is an important kind of pores. In order to study the elastic wave propagation in fractured medium through experiment, a new method to make artificial core with certain cracks using oil well cement and camphor sheet or thin steel sheet is put forward. Geometric parameters of the crack, such as shape, size and aspect ratio, are approximately equal to that of camphor sheet or thin steel sheet. Using the thin steel sheet to make crack can be more easy and accurate to control the crack angle than using camphor sheet. The crack opening scales at millimeters. The aspect ratio of cracks formed by camphor sheet ranges from 1.4 to 8, and aspect ratio of cracks formed by thin steel sheet ranges from 2.5 to 70. This method is proved simple and feasible by experiment practice, which can provide artificial cores with certain crack for acoustic wave propagation study.

Abstract: Multi-walled carbon nanotubes (MWCNTs) were synthesized from camphor by a chemical vapor deposition (CVD) method in a range of 750-900
. The catalyst was fed in three ways: (a) a sputtered Fe-film on a quartz substrate (b) vaporized ferrocene in an Ar flow; (c) both of (a) and (b). In the case (c), highly pure, dense and aligned MWCNT arrays formed on the quartz substrate at 850
, whereas nonaligned MWCNTs formed in the cases (a) and (b).