A New Method for Correcting Deviation of Volatiles Content and Chamber Pressure for Single Base Propellant

In this study, special treatment was applied to two production batches of single-base propellant to correct three of the most important properties in the final product. These properties are internal and external volatile content (IV%, EV% respectively) and chamber pressure, the special treatments depend on mixing two batches with different percentages of mixing starting with sieving and ended with blending to guarantee the homogeneity of the final batch. The batches under study (A and B), batch A with (IV% 0.53%) which must be not less than 0.6%, so it deviated from standard requirement and Bach B with (IV =0.88%), the treatment applied for these batches to generate (C and D) batches. Batch C was a mixture composed of (25% of batch A and 0.75% of batch B). batch D was a mixture composed of (50%batchA and 50% of batch B). Six samples were subjected to sieving and blending according to calculations to correct internal and external volatile content and chamber pressure. For all samples lab, ballistics test, and executive calculations were done. After the test observed that no significant difference between the test and the results of calculations for all samples with different mixing ratios either volatiles content or chamber pressure so according to the result achieved the procedure (Method) was dependable for correcting the deviation of volatiles content and chamber pressure. The selectivity of the optimum mixing ratio can be controlled by using the equation used in this study. The importance of this study in reducing material losses due to the non-conformity of the final product with the specification.

Evaluation of Novel Micronized Encapsulated Essential Oil–Containing Phosphate and Lactate Blends for Growth Inhibition of Listeria monocytogenes and Salmonella on Poultry Bologna, Pork Ham, and Roast Beef Ready-to-Eat Deli Loaves

Essential oils and their constituents are reported to possess potent antimicrobial activity, but their use in food processing is limited because of low solubility in aqueous systems and volatilization during processing. Two proprietary noncommercial essential oil–containing phosphate blends were evaluated for antimicrobial activity against Salmonella enterica cocktail (SC)–and Listeria monocytogenes (Lm)–inoculated deli meat products made from pork, poultry, or beef. Four treatments were tested on restructured cured pork ham, emulsified chicken bologna, and restructured beef loaf: nonencapsulated essential oil with phosphate version 1 at 0.45% of final batch (EOV145; chicken and pork, or EEOV245 beef), micronized encapsulated essential oil with phosphate version 2 at 0.60% of final batch (EEOV260), a 2.0% potassium lactate (PL) control, and a negative control (CN) with no applied antimicrobial agent. Compared with the CN, none of the antimicrobial agents (EEOV260, EOV145, PL) successfully limited Lm or SC growth to <2.0 log cycles over 49 days or 35 days of refrigerated storage, respectively. The PL and EEOV260-treated ham loaves did show Lm growth limiting ability of up to 1 log cycle by days 35 and 42. On formed roast beef, the EEOV260 was able to extend the lag phase and inhibited the growth of Lm in the same manner as the PL. For SC-treated samples, the following effects were observed: in poultry bologna treated with EEOV260, a lag-phase extension was observed through 35 days of storage compared with the other samples. For pork deli loaves, the EEOV260 inhibited growth of SC at days 21 and 28 to the same level of efficacy as PL (0.5 log cycle). In roast beef samples, on day 35, the SC growth was inhibited ca. 0.5 log CFU/g by EEOV260 when compared with the CN. In conclusion the EEOV260 can function to replace PL to limit Salmonella and Lm growth in ready-to-eat deli products. Further testing is needed to ensure consumer acceptability.

A Preliminary Evaluation of a Reusable Digital Sterilization Indicator Prototype

ABSTRACT Background Sterilization of critical and semicritical instruments used in patient care must undergo a terminal process of sterilization. Use of chemical and physical indicators are important in providing information on the sterilizer's performance during each cycle. Regular and periodic monitoring of sterilizers using biological indictors is necessary in periodically validating performance of sterilizers. Data loggers or independent digital parametric indicators are innovative devices that provide more information than various classes chemical indicators. In this study we evaluated a prototype of an independent digital parametric indicator's use in autoclaves. Aim The purpose of this study was to evaluate the performance of an independent digital indictor/data logger prototype (DS1922F) that could be used for multiple cycles within an autoclave. MG Materials and methods Three batches of the DS1922F (150 samples) were used in this study that was conducted in a series. The first batch was challenged with 300 sterilization cycles within an autoclave and the data loggers evaluated to study failures and the reason for failure, make corrections and improve the prototype design. After changes made based on studying the first batch, the second batch of the prototype (150 samples) were challenged once again with 300 sterilization cycles within an autoclave and failure studied again in further improvement of the prototype. The final batch (3rd batch) of the prototype (150 samples) was challenged again but with 600 cycles to see how long they would last. Kaplan-Meier survival analysis analyses of all three batches was conducted (α = 0.05) and failed samples qualitatively studied in understanding the variables involved in the failure of the prototype, and in improving quality. Results Each tested batch provided crucial information on device failure and helped in improvement of the prototype. Mean lifetime survival of the final batch (Batch 3) of prototype was 498 (480, 516) sterilization cycles in an autoclave. Conclusion In this study, the final batch of the DS1922F prototype data logger was found to be robust in withstanding the challenge of 600 autoclave cycles, with a mean lifetime of more than 450 cycles, multiple times more than prescribed number of cycles. Clinical significance Instrument reprocessing is among the important aspects of infection control. While stringent procedures are followed in instrument reprocessing within the clinic in assuring patient safety, regular use of sterilization process indicators and periodic biological validation of the sterilizer's performance is necessary. Chemical indicators for use in Autoclaves provide information on whether the particular cycle's parameters were achieved but do not provide at what specific point in time or temperature the failure occurred. Data loggers and associated reader software as the tested prototype in this evaluation (DS1922F), are designed to provide continuous information on time and temperature of the prescribed cycle. Data loggers provide immediate information on the process as opposed to Biological Indicators that take from days to a week in obtaining a confirmatory result. Further, many countries do not have the sterilization monitoring service infrastructure to meet the demands of the end users. In the absence of sterilization monitoring services, use of digital data loggers for each sterilization cycle is more pragmatic. How to cite this article Puttaiah R, Griggs J, D'Onofrio M. A Preliminary Evaluation of a Reusable Digital Sterilization Indicator Prototype. J Contemp Dent Pract 2014;15(5):626-635.