Evaluation of low wing-loading fuel conservative, short-haul transports

Fuel conservation that could be attained with two technology advancements, Q fan propulsion system and active control technology (ACT) was studied. Aircraft incorporating each technology were sized for a Federal Aviation Regulation (FAR) field length of 914 meters (3,000 feet), 148 passengers, and a 926 kilometer (500 nautical mile) mission. The cruise Mach number was .70 at 10100 meter (33,000 foot) altitude. The improvement resulting from application of the Q fan propulsion system was computed relative to an optimized fuel conservative transport design. The performance improvements resulting from application of ACT technology were relative to the optimized Q fan propulsion system configuration

Hydrodynamic motion of guiding elements within a magnetic switchyard in fast ignition conditions

Magnetic collimation via resistivity gradients is an innovative approach to electron beam control for the cone-guided fast ignition variant of inertial confinement fusion. This technique uses a resistivity gradient induced magnetic field to collimate the electron beam produced by the high-intensity laser–plasma interaction within a cone-guided fast ignition cone-tip. A variant of the resistive guiding approach, known as the “magnetic switchyard,” has been proposed which uses shaped guiding elements to direct the electrons toward the compressed fuel. Here, the 1D radiation-hydrodynamics code HYADES is used to investigate and quantify the gross hydrodynamic motion of these magnetic switchyard guiding elements in conditions relevant to their use in fast ignition. Movement of the layers was assessed for a range of two-layer material combinations. Based upon the results of the simulations, a scaling law is found that enables the relative extent of hydrodynamic motion to be predicted based upon the material properties of the switchyard, thereby enabling optimization of material-combination choice on the basis of reducing hydrodynamic motion. A multi-layered configuration, more representative of an actual switchyard, was also simulated in which an outer Au layer is employed to tamp the motion of the outermost guiding element of the switchyard

Electron acceleration by a transient intense-laser-plasma electrode

Rapid strides in the technology of laser plasma-based acceleration of charged particles leading to high brightness, tunable, monochromatic energetic beams of electrons and ions has been driven by potential multidisciplinary applications in cancer therapy, isotope preparation, radiography and thermonuclear fusion. Hitherto laser plasma acceleration schemes were confined to large-scale facilities generating a few tens of terawatt to petawatt laser pulses at repetition rates of 10 Hz or less. However, the need to make viable systems using high-repetition-rate femtosecond lasers has impelled recent research into novel targetry [1,2]. Of contemporary importance is the generation of supra thermal electrons, beyond those predicted by the scaling relation, reflected in both theoretical and computational work [3,4]. In this work we present evidence of generation of relativistic electrons (temperature >200 keV, maximum energies >1 MeV) at intensities that are two orders of magnitude lower than the relativistic intensity threshold. The novel targets [6] are 15 micron sized crystals suspended as aerosols in a gas interacting with a kHz, few-mJ femtosecond laser focussed to intensities of 10 PW/cm2. A pre-pulse with 1-5% of the intensity of the main pulse, arriving 4 ns early, is critical for hot electron generation. In addition to this unprecedented energy enhancement, we also characterize the dependence of X-ray spectra on the background gas of the aerosol. Intriguingly, easier the gas is to ionise, greater is the number of hot electrons observed, while the electron temperature remains the same. 2-D Radiation hydrodynamics and Particle-in-cell (PIC) simulations explain both the experimentally observed electron emission and the role of the low-density plasma in yield enhancement. We observe a two-temperature electron spectrum with about 50 and 240 keV temperatures consistent with the measurements made in the experiments. The simulations show that the following features contribute to the high-energy electron emission. The pre-pulse generates a hemispherical plasma-profile that enhances the coupling of the laser light. Overdense plasma is generated about the hemispherical cavity on the particle due to the main pulse interaction. The gradient in the plasma density in and around the cavity serves as a reservoir of low energy electrons to be injected into the particle potential and enables the hot electron generation observed in the experiments. Higher energy electron emission is dominantly from the edges of the hemispherical cavitation. The increase in total X-ray yield observed in the experiments scales with the number of electrons generated in the low density neighborhood surrounding the particle. In a simple-man picture, the laser interacts with the particle and ejects electrons from the particle. The particle acquires a strong positive potential that can only be brought down by ion expansion that occurs over 10's of picoseconds. The particle with strong positive potential acts as an 'accelerating electrode' for the electrons ionized in the low-density gas neighborhood. These results assume importance in the context of applications such as fast fuel ignition [6] or in medical applications of laser plasmas [7] where high irradiance of energetic electrons is of consequence. 1. D. Gustas et al., Phys. Rev. Accel. Beams, 21, 013401 (2018). 2. S. Feister et al , Opt. Express, 25, 18736 (2017). 3. B. S. Paradkar, S. I. Krasheninnikov, and F. N. Beg, Physics of Plasmas, 19, 060703 (2012). 4. A. P. L. Robinson, A. V. Areev, and D. Neely, Phys. Rev. Lett., 111, 065002 (2013). 5. R. Gopal, et al., Review of Scientific Instruments, 88, 023301 (2017). 6. M. Tabak et al., Physics of Plasmas, 1, 1626 (1994). 7. A. Sjogren, M. Harbst, C.-G. Wahlstrom, S. Svanberg, and C. Olsson, Review of Scientific Instruments, 74, 2300 (2003)

An overview of early investigational drugs for the treatment of human papilloma virus infection and associated dysplasia

Introduction: High-risk HPV (HR-HPV) related invasive cervical cancer (ICC) causes >270,000 deaths per annum world-wide with over 85% of these occurring in low-resource countries. Ablative and excisional treatment modalities are restricted for use with high-grade pre-cancerous cervical disease with HPV infection and low-grade dysplasia mostly managed by a watch-and-wait policy.Areas Covered: Various pharmacological approaches have been investigated as non-destructive alternatives for the treatment of HR-HPV infection and associated dysplasia. These are discussed dealing with efficacy, ease-of-use (physician or self-applied), systemic or locally applied, side-effects, cost and risks. The main focus is the perceived impact on current clinical practice of a self-applied, effective and safe pharmacological anti-HPV treatment.Expert opinion: Current prophylactic HPV vaccines are expensive, HPV type restricted and have little effect in already infected women. Therapeutic vaccines are under development but are also HPV type-restricted. At present, the developed nations use national cytology screening and surgical procedures to treat only women identified with HPV-related high-grade dysplastic disease. However, since HPV testing is rapidly replacing cytology as the test-of-choice, a suitable topically-applied and low-cost antiviral treatment could be an ideal solution for treatment of HPV infection per se with test-of-cure carried out by repeat HPV testing. Cytology would only then be necessary for women who remained HPV positive. Although of significant benefit in the developed countries, combining such a treatment with self-sampled HPV testing could revolutionise the management of this disease in the developing world which lack both the infrastructure and resources to establish national cytology screening programs

Evaluation of fatigue damage in steel structural components by magnetoelastic Barkhausen signal analysis

This paper is concerned with using a magnetic technique for the evaluation of fatigue damage in steel structural components. It is shown that Barkhausen effect measurements can be used to indicate impending failure due to fatigue under certain conditions. The Barkhausen signal amplitude is known to be highly sensitive to changes in density and distribution of dislocations in materials. The sensitivity of Barkhausen signal amplitude to fatigue damage has been studied in the low‐cycle fatigue regime using smooth tensile specimens of a medium strength steel. The Barkhausen measurements were taken at depths of penetration of 0.02, 0.07, and 0.2 mm. It was found that changes in magnetic properties are sensitive to microstructural changes taking place at the surface of the material throughout the fatigue life. The changes in the Barkhausen signals have been attributed to distribution of dislocations in stage I and stage II of fatigue life and the formation of a macrocrack in the final stage of fatigue

A Single-Arm, Proof-Of-Concept Trial of Lopimune (Lopinavir/Ritonavir) as a Treatment for HPV-Related Pre-Invasive Cervical Disease

BACKGROUND: Cervical cancer is the most common female malignancy in the developing nations and the third most common cancer in women globally. An effective, inexpensive and self-applied topical treatment would be an ideal solution for treatment of screen-detected, pre-invasive cervical disease in low resource settings. METHODS: Between 01/03/2013 and 01/08/2013, women attending Kenyatta National Hospital's Family Planning and Gynaecology Outpatients clinics were tested for HIV, HPV (Cervista®) and liquid based cervical cytology (LBC -ThinPrep®). HIV negative women diagnosed as high-risk HPV positive with high grade squamous intraepithelial lesions (HSIL) were examined by colposcopy and given a 2 week course of 1 capsule of Lopimune (CIPLA) twice daily, to be self-applied as a vaginal pessary. Colposcopy, HPV testing and LBC were repeated at 4 and 12 weeks post-start of treatment with a final punch biopsy at 3 months for histology. Primary outcome measures were acceptability of treatment with efficacy as a secondary consideration. RESULTS: A total of 23 women with HSIL were treated with Lopimune during which time no adverse reactions were reported. A maximum concentration of 10 ng/ml of lopinavir was detected in patient plasma 1 week after starting treatment. HPV was no longer detected in 12/23 (52.2%, 95%CI: 30.6-73.2%). Post-treatment cytology at 12 weeks on women with HSIL, showed 14/22 (63.6%, 95%CI: 40.6-82.8%) had no dysplasia and 4/22 (18.2%, 95%CI: 9.9-65.1%) were now low grade demonstrating a combined positive response in 81.8% of women of which 77.8% was confirmed by histology. These data are supported by colposcopic images, which show regression of cervical lesions. CONCLUSIONS: These results demonstrate the potential of Lopimune as a self-applied therapy for HPV infection and related cervical lesions. Since there were no serious adverse events or detectable post-treatment morbidity, this study indicates that further trials are clearly justified to define optimal regimes and the overall benefit of this therapy. TRIAL REGISTRATION: ISRCTN Registry 48776874

Tailored mesoscopic plasma accelerates electrons exploiting parametric instability

Laser plasma electron acceleration from the interaction of an intense femtosecond laser pulse with an isolated microparticle surrounded by a low-density gas is studied here. Experiments presented here show that optimized plasma tailoring by introducing a pre-pulse boosts parametric instabilities to produce MeV electron energies and generates electron temperatures as large as 200 keV with the total charge being as high as 350 fC/shot/sr, even at a laser intensity of a few times 1016 Wcm−2. Corroborated by particle-in-cell simulations, these measurements reveal that two plasmon decay in the vicinity of the microparticle is the main contributor to hot electron generation

Observation of extremely strong shock waves in solids launched by petawatt laser heating

Understanding hydrodynamic phenomena driven by fast electron heating is important for a range of applications including fast electron collimation schemes for fast ignition and the production and study of hot, dense matter. In this work, detailed numerical simulations modelling the heating, hydrodynamic evolution, and extreme ultra-violet (XUV) emission in combination with experimental XUV images indicate shock waves of exceptional strength (200 Mbar) launched due to rapid heating of materials via a petawatt laser. We discuss in detail the production of synthetic XUV images and how they assist us in interpreting experimental XUV images captured at 256 eV using a multi-layer spherical mirror