839 research outputs found
Modeling High Power Microwave Engagements Versus Swarming Adversaries
NPS NRP Executive SummaryHigh-power microwave (HPM) weapons use electromagnetic waves to neutralize electronic hardware, making them an ideal candidate to defeat drones. The effectiveness of HPM weapons is determined by their intensity, their spatial effect profile, and the mobility or spatial location of the HPM weapon platforms. NPS researchers have developed modeling approaches to perform mission-level studies of effects of such weapons, including determination of optimal tactics, determination of minimum platform specifications for mission success, and trade-off analysis between parameters.Office of Naval Research (ONR)ASN(RDA) - Research, Development, and AcquisitionThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.
Definition of the stimulated emission threshold in high- nanoscale lasers through phase-space reconstruction
Nanoscale lasers sustain few optical modes so that the fraction of
spontaneous emission funnelled into the useful (lasing) mode is high
(of the order of few 10) and the threshold, which traditionally
corresponds to an abrupt kink in the light in- light out curve, becomes
ill-defined. We propose an alternative definition of the threshold, based on
the dynamical response of the laser, which is valid even for lasers.
The laser dynamics is analyzed through a reconstruction of its phase-space
trajectory for pulsed excitation. Crossing the threshold brings about a change
in the shape of the trajectory and in the area contained in it. An unambiguous
definition of the threshold in terms of this change is shown theoretically and
illustrated experimentally in a photonic crystal laser
Bioetanol dari Limbah Kulit Singkong (Manihot Esculenta Crantz) melalui Proses Fermentasi
Carbohydrates can be obtained from tubers such as cassava. Cassava is a plant from family euphorbiaceae and typical tropical plants. Cassava peel is a major waste that contains carbohydrates. The peel of cassava can be used as an energy source, namely ethanol.The purpose of this study is to determine the contents of ethanol through the fermentation process of cassava peel where obtainable from Malino village, Batu Daka West, Tojo Una-Una. The parameters in this study was content of ethanol that was obtained by fermentation using saccaromyces cerevisiae yeast. The fermentation process was conducted by varying day of fermentation, 4, 6, 8, and 10 days. The results showed the fermentation of ethanol with time variation respectively is 4.50, 5.20, 6.00 and 4.00%. In conclusion, it can be said that the highest ethanol content is 6.00% with the fermentation time of 8 days
Pemanfaatan Biomassa Serbuk Gergaji sebagai Penyerap Logam Timbal
Lead (Pb) is one kind of heavy metal that has high level of toxicity. One way to reduce the level of Pb is by adsorption using cellulose and lignin of sawdust. The aim of this study is to determine the optimum pH, the optimum weight and to determine the adsorption capacity of sawdust when it absorbs Pb in solution of Pb(NO3)2. The adsorption process is carried out by using the various pH of 3, 4, 5, 6, 7, and 8 with a weight of 100 mg, and then the various weight of 100, 200, 300, 400, and 500 mg with the pH optimum. The analysis of Pb content in the solution was conducted by Spectro-direct. The analysis result shows the determination of pH occured at pH 7, Pb absorbed is 14.89 mg/g, and the percentage of Pb absorbed was 96.97%. For the determination of 400 mg of the adsorbent weight of Pb absorbed was 3,83 mg/g, the adsorption percentage of Pb was 99.98%, and the optimum adsorption for optimum weight was 0.15 mg Pb/mg sawdust
Survival of quantum effects for observables after decoherence
When a quantum nonlinear system is linearly coupled to an infinite bath of
harmonic oscillators, quantum coherence of the system is lost on a decoherence
time-scale . Nevertheless, quantum effects for observables may still
survive environment-induced decoherence, and be observed for times much larger
than the decoherence time-scale. In particular, we show that the Ehrenfest
time, which characterizes a departure of quantum dynamics for observables from
the corresponding classical dynamics, can be observed for a quasi-classical
nonlinear oscillator for times . We discuss this observation in
relation to recent experiments on quantum nonlinear systems in the
quasi-classical region of parameters.Comment: submitted to PR
Indicators of the need for ICU admission following suicide bombing attacks
<p>Abstract</p> <p>Introduction</p> <p>Critical hospital resources, especially the demand for ICU beds, are usually limited following mass casualty incidents such as suicide bombing attacks (SBA). Our primary objective was to identify easily diagnosed external signs of injury that will serve as indicators of the need for ICU admission. Our secondary objective was to analyze under- and over-triage following suicidal bombing attacks.</p> <p>Methods</p> <p>A database was collected prospectively from patients who were admitted to Hadassah University Hospital Level I Trauma Centre, Jerusalem, Israel from August 2001-August 2005 following a SBA. One hundred and sixty four victims of 17 suicide bombing attacks were divided into two groups according to ICU and non-ICU admission.</p> <p>Results</p> <p>There were 86 patients in the ICU group (52.4%) and 78 patients in the non-ICU group (47.6%). Patients in the ICU group required significantly more operating room time compared with patients in the non-ICU group (59.3% vs. 25.6%, respectively, <it>p </it>= 0.0003). For the ICU group, median ICU stay was 4 days (IQR 2 to 8.25 days). On multivariable analysis only the presence of facial fractures (<it>p </it>= 0.014), peripheral vascular injury (<it>p </it>= 0.015), injury ≥ 4 body areas (<it>p </it>= 0.002) and skull fractures (<it>p </it>= 0.017) were found to be independent predictors of the need for ICU admission. Sixteen survivors (19.5%) in the ICU group were admitted to the ICU for one day only (ICU-LOS = 1) and were defined as over-triaged. Median ISS for this group was significantly lower compared with patients who were admitted to the ICU for > 1 day (ICU-LOS > 1). This group of over-triaged patients could not be distinguished from the other ICU patients based on external signs of trauma. None of the patients in the non-ICU group were subsequently transferred to the ICU.</p> <p>Conclusions</p> <p>Our results show that following SBA, injury to ≥ 4 areas, and certain types of injuries such as facial and skull fractures, and peripheral vascular injury, can serve as surrogates of severe trauma and the need for ICU admission. Over-triage rates following SBA can be limited by a concerted, focused plan implemented by dedicated personnel and by the liberal utilization of imaging studies.</p
Alternative approach to electromagnetic field quantization in nonlinear and inhomogeneous media
A simple approach is proposed for the quantization of the electromagnetic
field in nonlinear and inhomogeneous media. Given the dielectric function and
nonlinear susceptibilities, the Hamiltonian of the electromagnetic field is
determined completely by this quantization method. From Heisenberg's equations
we derive Maxwell's equations for the field operators. When the nonlinearity
goes to zero, this quantization method returns to the generalized canonical
quantization procedure for linear inhomogeneous media [Phys. Rev. A, 43, 467,
1991]. The explicit Hamiltonians for the second-order and third-order nonlinear
quasi-steady-state processes are obtained based on this quantization procedure.Comment: Corrections in references and introductio
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