Maritime threat response

This report was prepared by Systems Engineering and Analysis Cohort Nine (SEA-9) Maritime Threat Response, (MTR) team members.Background: The 2006 Naval Postgraduate School (NPS) Cross-Campus Integrated Study, titled “Maritime Threat Response” involved the combined effort of 7 NPS Systems Engineering students, 7 Singaporean Temasek Defense Systems Institute (TDSI) students, 12 students from the Total Ship Systems Engineering (TSSE) curriculum, and numerous NPS faculty members from different NPS departments. After receiving tasking provided by the Wayne E. Meyer Institute of Systems Engineering at NPS in support of the Office of the Assistant Secretary of Defense for Homeland Defense, the study examined ways to validate intelligence and respond to maritime terrorist attacks against United States coastal harbors and ports. Through assessment of likely harbors and waterways to base the study upon, the San Francisco Bay was selected as a representative test-bed for the integrated study. The NPS Systems Engineering and Analysis Cohort 9 (SEA-9) Maritime Threat Response (MTR) team, in conjunction with the TDSI students, used the Systems Engineering Lifecycle Process (SELP) [shown in Figure ES-1, p. xxiii ] as a systems engineering framework to conduct the multi-disciplinary study. While not actually fabricating any hardware, such a process was well-suited for tailoring to the team’s research efforts and project focus. The SELP was an iterative process used to bound and scope the MTR problem, determine needs, requirements, functions, and to design architecture alternatives to satisfy stakeholder needs and desires. The SoS approach taken [shown in Figure ES-2, p. xxiv ]enabled the team to apply a systematic approach to problem definition, needs analysis, requirements, analysis, functional analysis, and then architecture development and assessment.In the twenty-first century, the threat of asymmetric warfare in the form of terrorism is one of the most likely direct threats to the United States homeland. It has been recognized that perhaps the key element in protecting the continental United States from terrorist threats is obtaining intelligence of impending attacks in advance. Enormous amounts of resources are currently allocated to obtaining and parsing such intelligence. However, it remains a difficult problem to deal with such attacks once intelligence is obtained. In this context, the Maritime Threat Response Project has applied Systems Engineering processes to propose different cost-effective System of Systems (SoS) architecture solutions to surface-based terrorist threats emanating from the maritime domain. The project applied a five-year time horizon to provide near-term solutions to the prospective decision makers and take maximum advantage of commercial off-the-shelf (COTS) solutions and emphasize new Concepts of Operations (CONOPS) for existing systems. Results provided insight into requirements for interagency interactions in support of Maritime Security and demonstrated the criticality of timely and accurate intelligence in support of counterterror operations.This report was prepared for the Office of the Assistant Secretary of Defense for Homeland DefenseApproved for public release; distribution is unlimited

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Development of high hydrogen capacity complex and chemical hydrides for hydrogen storage

Ph.DDOCTOR OF PHILOSOPH

Strategies of thermodynamic alternation on organic hydrogen carriers for hydrogen storage application: A review

An explosion of interest has arisen using organic-based materials, specifically cyclic organic hydrogen carriers for hydrogen storage due to their high hydrogen storage capacity, high volumetric energy density, reversibility, and non-toxicity. However, the unfavourable thermodynamic properties and high kinetic barriers of hydrogen desorption from these cyclic organic hydrogen carriers make them to be difficult in large-scale applications. In the past decades, tremendous efforts have been devoted to tailor both thermodynamic and kinetic properties of hydrogen absorption and desorption from such materials. Therefore, in this review, methods of fabrication of new materials in order to modify the dehydrogenation thermodynamic properties are discussed, which include the fusion of multiple organic rings, attachment of electron-donating substituents, incorporation of N/O/S atom into the aromatic rings, and introduction of alkali or alkaline earth metals to replace the protic H atom of O–H or N–H groups. Additionally, demonstrations for potential applications via using organic hydrogen carriers such as toluene, N-ethylcarbazole, and dibenzyl toluene are also described. The challenges and perspectives for the cyclic organic hydrogen storage materials are discussed at the end. It is expected that this review could provide new inspiration to expedite the development of cyclic organic hydrogen carriers with high hydrogen capacity and optimum thermodynamics for hydrogen storage

Ternary amide-hydride system: A study on LiAl(NH2)(4)-LiAlH4 interaction

LiAl(NH2)(4) is a ternary amide that readily decomposes to release ammonia at temperatures as low as similar to 90 degrees C. Owing to such instability as compared to binary amides, we hypothesize that the dehydrogenation mechanism involving ternary amide-hydride interaction would be significantly different from those of binary metal amide-hydride interaction. Therefore, in this study, interaction of LiAl(NH2)(4) and LiAlH4 has been investigated by means of mechanical milling and thermal method. It was found that dehydrogenation occurred spontaneously during the milling process and the rate of dehydrogenation increased with increasing amount of LiAlH4, suggesting an ion migration mediated dehydrogenation. As reaction progressed, the formation of Li3AlH6 as an intermediate was detected and a total of 8 equiv. of H-2 (7.5 wt%) can be released, forming LiH and AlN as the final product. In contrast, heating the homogenously ground LiAl(NH2)(4) and LiAlH4 sample resulted in the release of NH3 at low temperatures, indicating that NH3 mediation would take place in case of dehydrogenation. Further increase in temperature resulted in a rapid release of hydrogen from the interaction of the LiAl(NH)(2) and LiAlH4. It was also found that hydride with higher basicity is required to trigger amide-hydride interaction for dehydrogenation at low temperatures. (C) 2019 Elsevier B.V. All rights reserved

Investigations on the solid state interaction between LiAlH4 and NaNH2

10.1016/j.jssc.2010.07.014Journal of Solid State Chemistry18392040-2044JSSC

Calcium Amidoborane Ammoniate-Synthesis, Structure, and Hydrogen Storage Properties

A new type of hydrogen storage material-namely, calcium amidoborane ammoniate (Ca(NH(2)BH(3))(2)center dot 2NH(3))-is synthesized by reacting calcium amide and ammonia borane in a molar ratio of 1:2. Structural analyses show that this newly developed complex has a orthorhombic structure (space group Pna21) with unit-cell parameters of a = 18.673(3) angstrom, b = 5.2283(8) angstrom, c 8.5748(12) angstrom, and V = 873.16(22) angstrom(3). The presence of NH(3) in the crystal lattice facilitates the formation of dihydrogen bonding between BH center dot center dot center dot HN, which is considerably shorter than that in calcium amidoborane (Ca(NH(2)BH(3))(2)). As a consequence, the bond lengths of B-H and N-H are increased comparatively. Our experimental results show that more than 8 wt % hydrogen can be released from Ca(NH2BH3)(2)center dot 2NH(3) without borazine emission at 150 degrees C