Fabrication of cooled, graphite-lined structures

Improved method of fabricating cooled graphite-lined thrust chamber has been developed. Layer of nickel is electrodeposited onto outer surface of machined and contoured graphite liner. Coolant passages are machined into nickel layer, filled with wax, outer shell electroformed over this, and wax removed. Tests in flox/methane rocket engine were completely successful

Lost Wax Method Bronze Casting

Large scale bronze casting is a work intensive process that requires adequately equipped studio space, time, and a set of highly refined skills to complete the eight stages of the process. My goal was to construct a life sized bronze statue of a traditional Athabascan fisherman. I chose to sculpt a classically proportioned Greek style statue, using similar processes and ratios. I looked over photographs that I took in the Vatican museum and several anatomy books. Wendy Croskrey supported my research in large scale bronze casting a project this size. Through experimentation I discovered the importance of using the correct plaster and reinforcing molds properly. The process provided me with many firsts, such as a mold cracking open, plaster not setting, and having to recast a piece. Through hard work and careful consideration I was successful in completing the project

A Methodology for Three-Dimensional Quantification of Anterior Tooth Width

The use of cone-beam computed tomography (CBCT) technology has been shown to be more accurate in measuring individual incisor tooth widths than the use of wax exemplars. There were fewer differences by investigators using CBCT than others using an F-test in a mixed model of the measurement differences of investigators, wax type, and which tooth was measured. In addition, the frequency of outliers was less in the CBCT method (a total of 5) as compared to the two-dimensional measurements in ether Aluwax (a total of 8) or Coprwax (a total of 12). Both results indicate that CBCT measurements accounted more precisely for tooth width and level of eruption

Weak anion-exchange hypercrosslinked sorbent in on-line solid-phase extraction-liquid chromatography coupling to achieve automated determination with an effective clean-up

A mixed-mode polymeric sorbent was on-line coupled to liquid chromatography (LC) for the first time and applied it to the selective solid-phase extract a group of pharmaceuticals in complex environmental water samples. The mixed-mode polymeric sorbent is a high-specific surface area hypercrosslinked polymer resin (HXLPP) in the form of monodisperse microspheres further modified with 1,2-ethylenediamine (EDA) moieties. These properties allows its application as a weak anion-exchange (WAX) sorbent in the on-line solid-phase extraction (SPE) coupling. The on-line SPE-LC method developed using the HXLPP-WAX sorbent was successfully applied to percolate a large volume of ultrapure (500 ml), river (250 ml) and effluent sewage (100 ml) water samples. In all the cases, the HXLPP-WAX resin provided near total recoveries of the most acidic compounds studied and clean chromatograms. This is because the ion-exchange interactions enable a washing step to be added to the SPE protocol that removes the compounds with weak acidic, neutral and basic properties from the sample matrix

Pengaruh Konsentrasi Malam Putih ( Cera Alba ) Pada Suppositoria Basis Lemak Coklat ( Oleum Cacao ) Terhadap Laju Disolusi Parasetamol

The research about the influence of white wax concentration toward dissolution of parasetamol suppositories in cacao butter base of white wax concentration toward the dissolutions rate of parasetamol suppositories in cacao butter base. In this research by parasetamol suppositories in cacao butter base adding with white wax in parasetamol which was made by melted method and was poured into molds. Then the suppositories were tested physically including melting point, solidification time, hardness, and dissolution test. The results of this research showed that the greater concentration of white wax the smaller of dissolution rate. Keywords : Suppository, white wax, parasetamol, dissolutio

Transfer of Sulfamethazine from Contaminated Beeswax to Honey

A liquid chromatographic tandem mass spectrometric method for the determination of sulfa drugs in beeswax was developed. When performing residue control on beeswax intended for the fabrication of wax foundations, residues of sulfonamides were found. A migration test was set up to study whether sulfonamide-containing beeswax could lead to the contamination of honey. The higher the concentration of sulfamethazine doped in the wax, the higher was the concentration of sulfamethazine found in the honey. The maximum transfer was 15.6, 56.9, and 29.5% of the initial amount spiked in the wax foundation. In a second experiment, the percentage of sulfamethazine migrating from medicated winter feed to beeswax in relation to the concentration in the syrup and the contact time was studied. The maximum transfer of sulfamethazine from medicated sucrose syrup to beeswax was 3.1%

Pengaruh Cetakan Sillicone Rubber dan Temperatur Tuang Lilin terhadap Kualitas Pola Lilin pada Investment Casting

Investment casting method is widely used in the industry, it could produce complex and high precision products.One of the important stage in the investment is the wax pattern production, because the quality of the castproduct depends on the quality of the wax pattern. Sillicone rubber in alternative mold material has goodformability, low thermal conductivity, as well as the low cost of raw materials and the processes compared withmetal. Mold sillicone rubber and pour wax temperature varied 55 ºC, 65 ºC and 75 ºC to investigate the effectof these variables on shrinkage of linear wax patterns and volume wax pattern which expressed as percentage.The lowest average of linear shrinkage is 0.65%, which obtained at temperature 55 ºC. The lowest percentage ofvolumetric shrinkage is 7.59 %, which obtained at temperature 55 ºC

Quality indicators waxlike substances

В статье представлены результаты исследования качественных показателей воскоподобных веществ извлеченных из вторичных продуктов производства растительного масла методом контактной экстракции с использованием в качестве растворителей гексан и сивушное масло. Проанализирован качественный состав исследуемых образцов методом газовой хроматографии. Исследованы основные качественные показатели воскоподобных веществ и проведена сравнительная характеристика с промышленными аналогами.The article presents the results of qualitative research wax-like substances extracted from recycled vegetable oil production by extraction of the contact using hexane as a solvent and fusel oil. The aim of this work is to determine the physical and chemical indicators obtained wax-like substances. To address this goal the study used the method of gas chromatography, differential scanning calorimetry and the traditional chemical analysis methods. We analyzed by gas hramatografii qualitative composition of the test samples, allowing dentify more than 90% of wax esters. Installed temperature melting wax-like substances of the samples by methods of open capillary and differential scanning calorimetry, which amounted to 81ºS and 73,5ºS for hexane and fusel oil, respectively. The basic physical and chemical characteristics of wax-like substances, namely, acid number, saponification number, the essential number and iodine number. The comparative characteristic of physical-chemical indicators of the samples wax-like substance with industry peers. Comparative characteristics showed that the content of related substances in the test samples did not exceed the permissible values in comparison with beeswax and wax derived from the husks of sunflower seed