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1.
Considering ecological and economical issues in the new generation coating industries, the maximum utilization of naturally occurring materials for polymer synthesis can be an obvious option. In the same line, one of the promising candidates for substituting partially, and to some extent totally, petroleum-based raw materials with an equivalent or even enhanced performance properties, is the Cashew Nut Shell Liquid (CNSL). This dark brown-colored viscous liquid obtained from shells of the cashew nut can be utilized for a number of polymerization reactions due to its reactive phenolic structure and a meta-substituted unsaturated aliphatic chain. Therefore, a wide variety of resins can be synthesized from CNSL, such as polyesters, phenolic resins, epoxy resins, polyurethanes, acrylics, vinyl, alkyds, etc. The present article discusses the potential of CNSL and its derivatives as an environment friendly alternative for petroleum-based raw materials as far as polymer and coating industries are concerned. 相似文献
2.
Sachin Patil Sameer Sharma Anagha Nimbalkar Atmaram Pawar 《Drug development and industrial pharmacy》2013,39(3):315-326
ABSTRACTThe aim of the present study was to obtain cross-linked calcium-gellan beads containing diclofenac sodium as model drug, using full 33 factorial design. Drug quantity, pH of cross-linking solution, and speed of agitation were selected as variables for factorial design. The resultant beads were evaluated by scanning electron microscopy (SEM), percent yield, entrapment efficiency, micromeritic properties, swelling and drug release studies. The drug-loaded beads were spherical with size range of 0.85–1.8 mm. Percent yield and entrapment efficiency of various batches were in the range of 86.48–98.28% w/w and 72.52–92.74% w/w, respectively. Calcium-gellan beads containing diclofenac sodium showed pH-dependent swelling and drug release properties. Swelling and drug release were significantly higher in pH 7.4 phosphate buffer than 0.1N HCl. The swelling ratio for beads was up to 22 and 3 for phosphate buffer and 0.1N HCl, respectively. Cumulative diclofenac sodium release from calcium-gellan beads was 12–35% in 0.1N HCl within 2 h, whereas complete drug release was observed within 3–4 h in pH 7.4 phosphate buffer. 相似文献
3.
Anagha A. Belhekar Subbiah Ayyappan Arumugamangalam V. Ramaswamy 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1994,59(4):395-402
Two samples of Fe–Mo catalysts have been prepared from ferric nitrate and ammonium paramolybdate, one following a conventional procedure and the other by a new precipitation procedure in a buffer medium. The evolution of different Fe–Mo phases, from the fresh precipitate to the aged and then to the calcined state, has been followed by FT-IR spectroscopy. All the spectral vibrations have been related to different coordination spheres of Mo and Fe ions in the samples and a comparison with a commercial catalyst of similar composition has been made. The new preparation procedure leads to small, uniform (0·3 μm size) particles and a homogeneous morphology of phases as seen by scanning electron microscopy. Additionally, a higher surface area (10·3 m2 g?1), lower bulk density (0·66 g cm?3), a methanol conversion efficiency of > 90% and an HCHO selectivity of 95% distinguish this sample from the conventionally prepared one. Better thermal stability of this sample is inferred from the IR spectral and XRD analyses of the heat-treated (up to 800°C) samples and is related to the interaction between Fe2(MoO4)3 and MoO3 phases. 相似文献
4.
Micronization and nanoparticle production of poorly water-soluble drugs was investigated using single wet milling equipment operating in the attritor and stirred media modes. The drug particles in the median size range of 0.2?2??m were prepared by changing the milling mode and operating conditions of a Micros mill with a purpose of elucidating the dynamics of the wet milling process. It was determined that particle breakage due to mechanical stresses and aggregation due to insufficient stabilization are two competing mechanisms which together control the wet milling dynamics of the poorly water-soluble drugs. The study in the attritor mode using four different classes of stabilizers with six drugs indicated that steric stabilization worked better than electrostatic stabilization for the drugs studied. In addition, the existence of different minimum polymer concentrations for the stabilization of microsuspensions and nanosuspensions was indicated. The major role of a non-ionic polymer during the production of fine particles is its stabilization action through steric effects, and no experimental evidence was found to support the so-called Rehbinder effect. Periodic addition of the polymer as opposed to the addition of the polymer at the start of milling process was introduced as a novel processing method. This novel method of polymer addition provided effective stabilization and breakage of drug particles leading to a narrower and finer particle size distribution. Alternatively, it may allow shorter processing time and lower overall power consumption of the milling process for a desired particle size. 相似文献
5.
Gopalakrishnan Meempat Malur K. Sundareshan 《International Journal of Communication Systems》1994,7(1):49-65
A novel multiplexing scheme for integrated networks characterized by the coexistence of circuitswitched and packet-switched traffic is described in this paper. The new scheme is realized by a reinforcement of the basic movable boundary hybrid-switching technique, by incorporating an adaptive interpolation within the circuit-switched subsystem. The adaptation mechanism is controlled by the level of congestion in the packet queue. A precise queueing model for the multiplexer is developed and an analytical evaluation of the key performance parameters of interest, namely the loss probability and expected delay of the packet-switched subsystem, and the freeze-out fraction of the circuit-switched subsystem, is conducted. The results of several numerical studies are presented to describe the performance of the multiplexer under different conditions. Of particular significance resulting from these studies is the trade-off between the freeze-out fraction of the circuit-switched subsystem and the loss probability of the packet-switched subsystem; this trade-off may be exploited in a systematic design of the interrated multiplexer tailored to specific applications. 相似文献
6.
Do Y Soung Anagha Patade Dania A Khalil Edralin A Lucas Latha Devareddy Kathryn A Greaves Bahram H Arjmandi 《Nutrition journal》2006,5(1):12-6
Background
The health benefits of soy isoflavones have been widely investigated; however, there are some concerns as to whether soy isoflavones, similar to ipriflavone, a synthetic isoflavone, cause lymphocytopenia in postmenopausal women. Hence, the purpose of this study was to investigate the extent to which 12-month supplementation of 25 g soy protein containing 60 mg isoflavones alters lymphocyte counts or other hematological parameters in postmenopausal women who were not on hormone replacement therapy. 相似文献7.
Malur N Srinivasan 《Bulletin of Materials Science》1981,3(1):37-55
Heat conduction equations applicable to the solidification of grey cast iron cast in moulds of the same material were solved
for the cases of plate and cylindrical shaped castings made by pouring the metal at different temperatures into moulds of
different wall thicknesses preheated to different temperatures, when the heat transfer coefficient at the casting-mould interface
was assumed to have different values. An explicit finite difference method was used to solve the equations with the aid of
a digital computer. Local solidification times at different nodal points were determined from the solutions and a relationship
between the local solidification time and the location in a ‘casting’ was established. The application of local solidification
times for predicting the microstructure and estimating the ultimate tensile strength of these “castings” cast in metallic
moulds has been demonstrated. 相似文献
8.
Vandana Jamdar Mukesh Kathalewar Anagha Sabnis 《Journal of Coatings Technology and Research》2018,15(2):259-270
Polyethylene terephthalate (PET) waste recycling has become a worldwide research interest for industries and academic institutes due its inevitable environmental impact. The main objective of current research work is to target efficient recycling of PET waste from mineral water bottles by the glycolysis method and subsequent use of the recycled product for value-added coating application. In the present study, we report on MP-diol (2-methyl-1,3-propanediol) which is not explored much for the chemical recycling of PET, having a branched aliphatic diol with two primary hydroxyls, for glycolysis reaction. The reaction parameters were optimized for microwave-assisted technique by varying the ratio of raw materials, reaction time, temperature, and power. The reaction parameters were optimized, and the recycled oligomeric product (OPETMPD) was separated, purified, and characterized by chemical and spectroscopic methods. Subsequently, dimethacrylated oligoesters of PET oligomer (UV oligomer) were synthesized by methacrylation of the glycolyzed PET product (OPETMPD). The synthesized UV oligomer was evaluated using chemical and spectroscopic methods. Ultraviolet (UV) radiation-curable formulations were prepared using synthesized UV oligomer and applied on wooden panels. The coatings were cured using UV-curing machine and evaluated for their performance properties. The partial replacement of UV oligomer in UV formulations exhibited comparative coating performance properties with respect to conventional UV formulation. 相似文献
9.
The aim of the present study was to obtain cross-linked calcium-gellan beads containing diclofenac sodium as model drug, using full 3(3) factorial design. Drug quantity, pH of cross-linking solution, and speed of agitation were selected as variables for factorial design. The resultant beads were evaluated by scanning electron microscopy (SEM), percent yield, entrapment efficiency, micromeritic properties, swelling and drug release studies. The drug-loaded beads were spherical with size range of 0.85-1.8 mm. Percent yield and entrapment efficiency of various batches were in the range of 86.48-98.28% w/w and 72.52-92.74% w/w, respectively. Calcium-gellan beads containing diclofenac sodium showed pH-dependent swelling and drug release properties. Swelling and drug release were significantly higher in pH 7.4 phosphate buffer than 0.1N HCl. The swelling ratio for beads was up to 22 and 3 for phosphate buffer and 0.1N HCl, respectively. Cumulative diclofenac sodium release from calcium-gellan beads was 12-35% in 0.1N HCl within 2 h, whereas complete drug release was observed within 3-4 h in pH 7.4 phosphate buffer. 相似文献