1,164 research outputs found
IMPROVING SUSPENDED STOCK POLICIES AND PROCEDURES AT DEFENSE LOGISTICS AGENCY SAN JOAQUIN
Defense Logistics Agency (DLA) Distribution San Joaquin (DDJC) manages a substantial portion of DLA’s 208.5 million, posing challenges in storage capacity, and operational efficiency. This research aimed to dissect the reasons behind the accumulation of suspended stock and offer actionable recommendations. Through various analysis methodologies, the study sought to enhance DDJC’s suspended stock processing, potentially improving the logistics readiness of all military services.DDJC’s suspended stock accumulation stems from customer returns, quality deficiencies, legal constraints, counterfeit items, and more. These issues strain resources and hinder operational effectiveness within DLA. Through trend analysis, ABC inventory analysis, condition code and depot level repairable classification, a survey, and insights from prior DLA initiatives, this research sought to provide an understanding of suspended stock management at DDJC.Our research did not identify a single issue that specifically led to suspended stock accumulation at DDJC or uncover a specific policy or SOP that DDJC could revise to improve suspended stock processing. Based on our research and to realize the most ROI, we recommend a full review of the training tools and job breakdown sheets DDJC uses to ensure alignment with DLA SOPs, and a focus on clearing parts in category code A, as well as suspended depot level repairable items.Distribution Statement A. Approved for public release: Distribution is unlimited.Lieutenant Commander, United States NavyLieutenant Commander, United States NavyLieutenant Commander, United States Nav
Comparison between the calculated and measured dose distributions for four beams of 6 MeV linac in a human-equivalent phantom
Radiation dose distributions in various parts of the body are of importance in radiotherapy. Also, the percent depth dose at different body depths is an important parameter in radiation therapy applications. Monte Carlo simulation techniques are the most accurate methods for such purposes. Monte Carlo computer calculations of photon spectra and the dose ratios at surfaces and in some internal organs of a human equivalent phantom were performed. In the present paper, dose distributions in different organs during bladder radiotherapy by 6 MeV X-rays were measured using thermoluminescence dosimetry placed at different points in the human-phantom. The phantom was irradiated in exactly the same manner as in actual bladder radiotherapy. Four treatment fields were considered to maximize the dose at the center of the target and minimize it at non-target healthy organs. All experimental setup information was fed to the MCNP-4b code to calculate dose distributions at selected points inside the proposed phantom. Percent depth dose distribution was performed. Also, the absorbed dose as ratios relative to the original beam in the surrounding organs was calculated by MCNP-4b and measured by thermoluminescence dosimetry. Both measured and calculated data were compared. Results indicate good agreement between calculated and measured data inside the phantom. Comparison between MCNP-4b calculations and measurements of depth dose distribution indicated good agreement between both
Diversity of inulinase-producing fungi associated with two Asteraceous plants, Pulicaria crispa (Forssk.) and Pluchea dioscoridis (L.) growing in an extreme arid environment
Inulinases are potentially valuable enzymes catalyze the hydrolysis of plant’s inulin into high fructose syrups as sweetening ingredients for food industry and ethanol production. The high demands for inulinase enzymes have promoted interest in microbial inulinases as the most suitable approach for biosynthesis of fructose syrups from inulin. Arid land ecosystem represents a valuable bioresource for soil microbial diversity with unique biochemical and physiological properties. In the present study, we explored the fungi diversity associated with the rhizosphere and rhizoplane of two desert medicinal plants namely Pluchea dioscoridis and Pulicaria crispa growing in the South-Eastern desert of Aswan, Egypt. A total of 180 fungal isolates were screened based on their ability to grow on potato dextrose agar medium supplemented with 1% inulin. The isolated fungal colonies were morphologically identified according to cultural characteristics and spore-bearing structure. In addition, the inulinase activity of the isolated fungi was examined spectrophotometrically. Among these, Aspergillus terreus var. terreus 233, Botrytis cinerea, Aspergillus aegyptiacus, Cochliobolus australiensis 447 and Cochliobolus australiensis exhibited high inulinase activity ranging from 5.05 to 7.26 U/ml. This study provides a promising source of microbial inulinase, which can be scaled up for industrial applications.
DOI: http://dx.doi.org/10.5281/zenodo.120564
Effects of Different Substituents on the Crystal Structures and Antimicrobial Activities of Six Ag(I) Quinoline Compounds
The syntheses and single crystal X-ray structures of [Ag(5-nitroquinoline)(2)]NO3 (1), [Ag(8-nitroquinoline)(2)]NO3 center dot H2O (2), [Ag(6-methoxy-8-nitroquinoline)(NO3)](n) (3), [Ag(3-quinolinecarbonitrile)(NO3)](n) (4), [Ag(3-quinolinecarbonitrile)(2)]NO3 (5), and [Ag(6-quinolinecarboxylic acid)(2)]NO3 (6) are described. As an alternative to solution chemistry, solid-state grinding could be used to prepare compounds 1 and 3, but the preparation of 4 and 5 in this way failed. The Ag(I) ions in the monomeric compounds 1, 2, 5, and 6 are coordinated to two ligands via the nitrogen atoms of the quinoline rings, thereby forming a distorted linear coordination geometry with Ag-N bond distances of 2.142(2)-2.336(2) angstrom and N-Ag-N bond angles of 163.62(13)degrees-172.25(13)degrees. The 1D coordination polymers 3 and 4 contain Ag(I) centers coordinating one ligand and two bridging nitrate groups, thereby forming a distorted trigonal planar coordination geometry with Ag-N bond distances of 2.2700(14) and 2.224(5) angstrom, Ag-O bond distances of 2.261(4)-2.536(5) angstrom, and N-Ag-O bond angles of 115.23(5)degrees-155.56(5)degrees. Hirshfeld surface analyses of compounds 1-6 are presented as d(norm) and curvedness maps. The d(norm) maps show different interaction sites around the Ag(I) ions, i.e., Ag center dot center dot center dot Ag interactions and possible O-H center dot center dot center dot O, C-H center dot center dot center dot O, C-H center dot center dot center dot N, and C-H center dot center dot center dot C hydrogen bonds. Curvedness maps are a good way of visualizing pi-pi tacking interactions between molecules. The antimicrobial activities of compounds 1, 2, and 6 were screened against 15 different multidrug-resistant strains of bacteria isolated from diabetic foot ulcers and compared to the antimicrobial activities of the clinically used silver sulfadiazine (SS). Compound 2 showed activity similar to SS against this set of test organisms, being active against all strains and having slightly better average silver efficiency than SS (5 vs 6 mu g Ag/mL). Against the standard nonresistant bacterial strains of Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, and Streptococcus pyogenes, compound 1 performed better than silver nitrate, with an average MIC of 6 mu g Ag/mL versus 18 mu g Ag/mL for the reference AgNO3. Electrospray ionization mass spectrometry (ESI-MS) analyses of compounds 3 and 6 in DMSO/MeOH confirm the two-coordinated Ag+ complexes in solution, and the results of the H-1 NMR titrations of DMSO solutions of 5-nitroquinoline and 8-nitroquinoline with AgNO3 in DMSO suggest that 5-nitroquinoline is more strongly coordinated to the silver ion
A modular multilevel voltage-boosting Marx pulse-waveform generator for electroporation applications
In order to overcome the limitations of the existing classical and solid-state Marx pulse generators, this paper proposes a new modular multilevel voltage-boosting Marx pulse generator (BMPG). The proposed BMPG has hardware features that allow modularity, redundancy, and scalability as well as operational features that alleviate the need of series-connected switches and allows generation of a wide range of pulse waveforms. In the BMPG, a controllable, low-voltage input boost converter supplies, via directing/blocking (D/B) diodes, two arms of a series modular multilevel converter half-bridge sub-modules (HB-SMs). At start up, all the arm's SM capacitors are resonantly charged in parallel from 0 V, simultaneously via directing diodes, to a voltage in excess of the source voltage. After the first pulse delivery, the energy of the SM capacitors decreases due to the generated pulse. Then, for continuous operation without fully discharging the SM capacitors or having a large voltage droop as in the available Marx generators, the SM capacitors are continuously recharged in parallel, to the desired boosted voltage level. Because all SMs are parallelly connected, the boost converter duty ratio is controlled by a single voltage measurement at the output terminals of the boost converter. Due to the proposed SMs structure and the utilization of D/B diodes, each SM capacitor is effectively controlled individually without requiring a voltage sensor across each SM capacitor. Generation of the commonly used pulse waveforms in electroporation applications is possible, while assuring balanced capacitors, hence SM voltages. The proposed BMPG has several topological variations such as utilizing a buck-boost converter at the input stage and replacing the HB-SM with full-bridge SMs. The proposed BMPG topology is assessed by simulation and scaled-down proof-of-concept experimentation to explore its viability for electroporation applications
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