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A validating approach for electromagnetic thermal (EMT) conversion of a composite broadband absorbent metamaterials (AMs) is proposed in this paper. The integrated multilayer AMs consisting of top square loop (Q-loops) array layer, middle metal plate-polymer sandwich, bottom Q-loops array layer stacked vertically is analyzed with finite-different time-domain (FDTD) algorithm and fabricated by High Density Interconnector (HDI) process and Micro-electromechanical Systems (MEMS) technology. The implemented composite layered structure with the dielectrics and subsequent multi metal loops has broadband bandwidth over 2.5GHz in X-bands. High absorption performance in various incident waves with different polarizations and incident angles basically maintains a fixed efficient level of the AMs with diverse absorbing states in wide operating band. Electromagnetics and thermal multiphysics analysis validates the EMT conversion of the AMs in induced strong electromagnetic resonance. The integrated thermal conduction device is loaded on the back of AMs to transfer the converted thermal energy in time, which effectively reduces the surface thermal distribution. Finally, absorbent properties tested by free space methods and thermocouple and infrared thermal imaging (ITI) system shows the polarization independent energy transformation in greatly accordance with numerical analysis. This investigation shows the potential application of AMs in stealth systems to achieve both electromagnetic stealth and infrared thermal stealth through EMT energy conversion.

Here we present a novel application of cortical bone trajectory (CBT) fixation utilizing robotic guidance in a previously instrumented spine with a traditional pedicle screw (PS), obviating the need for a larger posterior incision, reducing the risk of infection, muscular dissection, and likely decreasing hospital length of stay. A 60-year-old woman with prior left L3-L4 extreme lateral interbody fusion and unilateral percutaneous PS placed at L3 to L5 presented with progressive bilateral lower-extremity pain and diminished sensation in the S1 dermatome secondary to adjacent segment disease (ASD). The patient underwent an L5-S1 anterior lumbar interbody fusion for indirect decompression and restoration of segmental lordosis. After the first stage was completed, she was turned prone for posterior percutaneous instrumentation. Given prior instrumentation at L3-L5 on the left side, a robot planning software was used to plan a cortical bone screw on the left L5 pedicle. A left S1 PS was then planned with the screw head aligning with the left L5 cortical bone screw. Instrumentation was then placed percutaneously using the robot bilaterally without issue. Intraoperative fluoroscopic imaging demonstrated accurate placement of PS, and postoperative computed tomography demonstrated the excellent positioning of all PSs. This report is the first documented case of a robotically placed CBT screw placed in the same pedicle as a prior traditional PS for ASD. This method expands the surgical options for ASD to include robotic percutaneous placement of posterior instrumentation at the same level as previous instrumentation.

Bionic adaptive camouflage material is a new artificial functional material, whose surface color can change adaptively according to the optical environments. Therefore, how to reduce the visual detectability of this material becomes a research hotspot of digital camouflage stealth technology. In order to clarify the limitations and opportunities of the bionic adaptive camouflage materials in the field of visual stealth, we summarize the applications of current adaptive camouflage materials and carry out a prospect of next-generation photonic crystal infrared camouflage material in this review. It is expected to provide a solution for the demand of digital camouflage adaptive materials in the modern battle field.

Purpose The purpose of this paper is to characterise the effects of mission and performance parameters on the design space of low observable subsonic unmanned combat aerial vehicles (UCAVs) operating in typical Hi-Lo-Hi ground strike missions. Design/methodology/approach Conceptual design methodologies appropriate to low observable, tailless UCAVs have been integrated into a multidisciplinary aircraft design environment, GENUS, developed at Cranfield University’s aircraft design group. A basic Hi-Lo-Hi mission is designed and a baseline configuration is established through the GENUS framework. Subsequently, an evolutionary optimiser and a robust gradient-based optimiser are used to obtain convergent design solutions for various leading edge sweep angles, mission ranges, cruise Mach numbers and other operational constraints. Findings The results indicate that performance constraints, specifically in the form of specific excess power (SEP), have a large influence on the overall sizing of subsonic tailless UCAVs. This requirement drives the engine sizing, which represents a considerable proportion of the empty and gross mass of the vehicle. Cruise Mach number studies show that no significant advantages exist for operating at low speeds while maintaining performance requirements consistent with combat missions. There is a drastic increase in the vehicle’s mass and thrust requirements for flight speeds above Mach 0.8, with low sweep configurations showing a more pronounced effect. Increases in the range are not overly dependent on the leading edge sweep angle. Top-level radar cross section (RCS) results also favour configurations with higher leading edge sweep angles, especially from the nose-on aspect. Finally, research and development costs are shown to be directly linked to engine size. Originality/value This research shows the use of an integrated aircraft design environment that incorporates aerodynamics, performance, packaging and low observability aspects into the optimisation loop. Through this methodology, this study supports the efforts towards characterising and establishing alternate visions of the future of aerial warfare through the use of low cost, survivable unmanned platforms in network-centric cooperative tasks.

The ever-changing battlefield environment, as well as the emergence of global command and control architectures currently used by armed forces around the globe, requires the use of robust and adaptive technologies integrated into a reliable platform. Unmanned Combat Aerial Vehicles (UCAVs) aim to integrate such advanced technologies while also increasing the tactical capabilities of combat aircraft. This paper provides a summary of the technical and operational design challenges specific to UCAVs, focusing on high-performance, and stealth designs. After a brief historical overview, the main technology demonstrator programmes currently under development are presented. The key technologies affecting UCAV design are identified and discussed. Finally, this paper briefly presents the main issues related to airworthiness, navigation, and ethical concerns behind UAV/UCAV operations.

A case study approach, based on interviews and document reviews, was used to analyze the systems engineering processes of the SEP (Armored Multirole Vehicle, in Swedish) and the Visby class corvette cases respectively. The focus was on signature management. The result is a thorough investigation of what worked in the cases studied. The main conclusions can be summarized in three points. 1) A preferred workflow from mission analysis to sub system design has been derived from lessons identified; 2) The three main success factors identified were: building technology demonstrators, having an Integrated Product Team approach, and establishing stealth as a key system design goal; 3) Coherence and traceability between military needs on the battlefield and signature requirements need further research.

In this paper, two typical stealth aircraft concepts (wing fuselage blended and flying-wing) were designed. Then three gradually changed surface distribution models with the same planform for each concept were created. Based on the multilevel fast multipole algorithm (MLFMA), the vertical polarization transmitting/vertical polarization receiving (VV) and horizontal polarization transmitting/horizontal polarization receiving (HH) radar cross section (RCS) characteristics were simulated with five frequencies between 0.1 and 1.0 GHz. The influences and mechanisms of aircraft surface distribution on electromagnetic scattering characteristics were investigated. The results show that for the wing fuselage blended concept, the VV RCS of this frequency range is higher than the HH RCS in most cases, while it is just the opposite for the flying-wing concept. As for the two aircraft concepts, the RCS levels of HH and VV both decrease with the frequency increasing, but the HH RCS has a faster downward trend. The surface distribution has little influence on HH RCS characteristics. On the contrary, it has a significant impact on VV RCS characteristics, and the amplitude of the VV RCS increases with the surface thickness.

Rheumatoid arthritis (RA) is the most common inflammatory rheumatic disease, affecting almost 1% of the world population. Although the cause of RA remains unknown, the complex interaction between immune mediators (cytokines and effector cells) is responsible for the joint damage that begins at the synovial membrane. Activated macrophages are critical in the pathogenesis of RA and have been shown to specifically express a receptor for the vitamin folic acid (FA), folate receptor (FR). This particular receptor allows internalization of FA-coupled cargo. In this review we will address the potential of nanoparticles as an effective drug delivery system for therapies that will directly target activated macrophages. Special attention will be given to stealth degree of the nanoparticles as a strategy to avoid clearance by macrophages of the mononuclear phagocytic system (MPS). This review summarizes the application of FA-target nanoparticles as drug delivery systems for RA and proposes prospective future directions., Eugénia Nogueira (SFRH/BD/81269/2011) holds a scholarship from Fundação para a Ciência e a Tecnologia (FCT). This study was funded by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement NMP4-LA-2009-228827 NANOFOL. The authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the Project “BioHealth — Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 — O Novo Norte), QREN, FEDER. This work was also supported by FCT I.P. through the strategic funding UID/BIA/04050/2013. We thank the Centro Hospitalar do Alto Ave (Guimarães, Portugal) for providing radiographic joint images.

In order to study stealth strike-fighter, an analysis on stealth-aerodynamic integration and conceptual design is conducted. A conceptual 3-D digital model with internal antiship missiles and air-to-air missiles is designed in CATIA software. Based on the physical optics and equivalent electromagnetic current methods, using the self-programmed RCSAnsys software, the Radar Cross Section (RCS) characteristics and characteristics of scattering intensity distribution of the model are numerically simulated. Based on the turbulence theory of standard k-ε equations, using Fluent software, the pressure, velocity and lift-to-drag characteristics of the conceptual aircraft are numerically simulated. The simulation results show that the stealth and aerodynamic characteristics of the conceptual aircraft can be designed through integration analysis process, which can provide technical support to the design of the advanced operational aircrafts.

A structure is discussed for absorbing incident radiation, either electromagnetic (EM) or sound. Such a surface structure is needed, for example, in a highly sensitive high-frequency gravitational wave or HFGW detector such as the Li-Baker. The multi-layer absorber, which is discussed, is constructed with metamaterial [MM] layer or layers on top. This MM is configured for a specific EM or sound radiation frequency band, which absorbs incident EM or sound radiation without reflection. Below these top MM layers is a substrate of conventional EM-radiation absorbing or acoustical absorbing reflective material, such as an array of pyramidal foam absorbers. Incident radiation is partially absorbed by the MM layer or layers, and then it is more absorbed by the lower absorbing and reflecting substrate. The remaining reflected radiation is even further absorbed by the MM layers on its “way out_ so that essentially all of the incident radiation is absorbed _ a nearly perfect black-body absorber. In a HFGW detector a substrate, such as foam absorbers, may outgas into a high vacuum and reduce the capability of the vacuum–producing equipment, however, the layers above this lowest substrate will seal the absorbing and reflecting substrate from any external vacuum. The layers also serve to seal the absorbing material against air or water flow past the surfaces of aircraft, watercraft or submarines. Other applications for such a multiple-level radiation absorber include stealth aircraft, missiles and submarines.

The tactical need for fixed wing aircraft with hovering capably has long been recognized by the military for two reasons: increased safety when landing on aircraft carriers and higher velocities that the ones obtainable with rotary wing aircraft. Thus far, the only concept governing the field of vertical flight was to use thrust either from a lift fan-F35, puffer ducts –Harrier or smaller jet engines-D0 31 or Yak-141, i.e. direct lift thrust. In this paper we will look at the prospect of using a combination of the Coanda effect with the Venturi effect to generate lift by socalled “supercirculation”. This novel approach can yield many advantages to conventional vertical lifting by providing a more stable platform and requiring lower power settings – and thus lower fuel consumption. The aircraft has a fixed, negatively sweped wing that uses circulation control to achieve lift at zero air speed. The fluid used for supercirculation will come from the fan thrust reversers – which, if correctly managed, can give a sufficient flow for lifting the craft and also a negative thrust component to compensate for the positive thrust of the primary flow (not diverted).

This new security development is expected to increase interest fromNorthern European states in supporting the development of conceptually newstealthy ground platforms, incorporating a decade of advances in technology andexperiences from stealth platforms at sea and in the air. The scope of thiscase study is to draw experience from where we left off. At the end of the1990s there was growing interest in stealth for combat vehicles in Sweden. Anambitious technology demonstrator project was launched. One of the outcomes wasa proposed Systems Engineering process tailored for signature managementpresented to SPIE in 2002.(Olsson et.al, A systems approach…, Proc. SPIE 4718 )The process was used for the Swedish/BAE Systems Hägglunds AB development of amultirole armored platform (The Swedish acronym is SEP). Before development wascompleted there was a change of procurement policy in Sweden from domesticdevelopment towards Governmental Off-The-Shelf, preceded by a Swedish ArmedForces change of focus from national defense only, towards expeditionarymissions. Lessons learned, of value for future development, are presented. Theyare deduced from interviews of key-personnel, on the procurer and industrysides respectively, and from document reviews.

Weapons of both defense and offense have grown steadily in their effectiveness--especially since the industrial revolution. The mass destruction of humanity, by parts or in whole, became reality with the advent of toxic agents founded on chemistry and biology or nuclear weapons derived from physics. The military's new non-combat roles, combined with a quest for non-lethal weapons, may change the picture in regard to conventional defense establishments but are unlikely to deter bellicose tyrants or the new terrorists from using the unlimited potential of today's and tomorrow's arsenals. The author addresses the issues that are raised by this developing situation with the intent of seeking those ethics that will enable us to survive in a future and uncertain world.

Infrared signature management (IRSM) has been a primary aeronautical concern for over 50 years. Most strategies and technologies are limited by the second law of thermodynamics. In this article, IRSM is considered in light of theoretical developments over the last 15 years that have put the absolute status of the second law into doubt and that might open the door to a new class of broadband IR stealth and cloaking techniques. Following a brief overview of IRSM and its current thermodynamic limitations, theoretical and experimental challenges to the second law are reviewed. One proposal is treated in detail: a high power density, solid-state power source to convert thermal energy into electrical or chemical energy. Next, second-law based infrared signature management (SL-IRSM) strategies are considered for two representative military scenarios: an underground installation and a SL-based jet engine. It is found that SL-IRSM could be technologically disruptive across the full spectrum of IRSM modalities, including camouflage, surveillance, night vision, target acquisition, tracking, and homing.

This is a lucid read on a complex virus, cytomegalovirus (CMV), that affects those in all ages of life from the unborn fetus to the elderly pensioner. Griffiths has used one of the many self-publishing, internet-based services to publish and distribute this book via the popular amazon.com and amazon.co.uk websites. All profits from its sale are being donated to the Royal Free Charity, which has supported his research on CMV for many years. The book is arranged chronologically; the 18 chapters are headed by a range of years, starting with 1910 (Chapter 1) and ending in 2012 (Chapter 18). An interesting approach is used in the Prologue (dated 180 million years ago), where the virus speaks to the reader in the first person. The virus’s voice summarizes the most important aspects of its virology and its clinical impact on a largely unsuspecting human population. Several important themes are introduced here: 1) the author’s clear views about the relative irrelevance of experiments on mice to the human situation; 2) the missed opportunities that studying CMV earlier could have created by helping the scientific community to understand and more effectively combat other viruses, such as HIV; and 3) how a vaccine approach would be the best way to control this viral pathogen. The book starts off by discussing other viruses of clinical importance (polio, varicella zoster, rubella, herpes simplex, and HIV), gradually setting the scene for the emergence of CMV. Interspersed between the history of the science and the emerging clinical importance of this virus are patient case histories. At least 1 case is described in each chapter (suitably anonymized with alternative and sometimes memorable names, such as “Stevie Headbanger”), covering the most common clinical CMV scenarios. These include CMV infection and disease in newborns, pregnant women, transplant patients, persons with HIV/AIDS, and other immunocompromised patients. Other cases also demonstrate the virus’ impact on otherwise healthy teenagers studying for exams, retirees caring for their grandchildren, and recovering burn and gunshot victims (in this instance, Pope John Paul II). Such case histories provide clear examples of complications arising from both primary and reactivated CMV infection and disease. Most (if not all) of the relevant major scientific and medical advances related to CMV are noted, including the development of the various anti-CMV drugs, with due credit given to the investigating teams. Most passionately of all, Griffiths carefully charts gradually changing attitudes to the development of a CMV vaccine. Curiously, the author writes about his own role in the CMV story in the third person—perhaps to maintain a scientist’s natural objectivity. Notably, in the latter half of the book, he tends to use more technical jargon, which may cause problems for some readers. Yet, this does not necessarily detract from the book’s value; rather, it may provide reassurance to the readers that they are, indeed, in the hands of a master. The development of a CMV vaccine is now gaining support internationally, thanks in no small part to the efforts of the author. When the vaccine is eventually available, anyone with any doubts about its potential benefits can simply read this little book.

This paper studies the radar cross section (RCS) of carrier electronic warfare airplanes. Under the typical naval operations section, the mathematical model of the radar wave’s pitch angle incidence range analysis is established. Based on the CATIA software, considering dynamic deflections of duck wing leading edge flaps, flaperons, horizontal tail, and rudder, as well as aircraft with air-to-air missile, anti-radiation missile, electronic jamming pod, and other weapons, the 3D models of carrier electronic warfare airplanes Model A and Model B with weapons were established. Based on the physical optics method and the equivalent electromagnetic flow method, by the use of the RCSAnsys software, the characteristics of carrier electronic warfare airplanes’ RCS under steady and dynamic flights were simulated under the UHF, X, and S radar bands. This paper researches the detection probability of aircraft by radars under the condition of electronic warfare, and completes the mathematical statistical analysis of the simulation results. The results show that: The Model A of carrier electronic warfare airplane is better than Model B on stealth performance and on discover probability by radar detection effectively.

The nature and characteristics of attack unmanned combat aerial vehicle (UCAV) are analyzed. The principles of selecting takeoff thrust-weight ratio and takeoff weight of attack UCAV are presented by analyzing the statistical data of weights for various main combat aircraft. The UCAV airborne weapons are analyzed, followed by the preliminary estimation of the payload weight. Various typical engines are analyzed and one of them is selected. Then the takeoff weight of the UCAV is determined. Based on some basic parameters and assumptions, the qualitative decomposition calculation for takeoff weight is completed. The key factors for obtaining longer endurance of aircraft with small aspect ratio configuration are found to be high lift-drag ratio and internal space. On the basis of the conclusions mentioned above, a highly blended flying-wing plus lifting body concept is proposed. According to this concept, the UCAV configuration is designed and optimized. Finally, the UCAV configuration with small aspect ratio, high lift-drag ratio, and high stealth characteristic is obtained.

In 2005 and in 2012, the SHarp Edge Flight EXperiment SHEFEX I and SHEFEX II of DLR have been established. Low lift-to-drag ratio of them limits active control ability. This paper studies on a sharp-edge stealthy re-entry vehicle with high lift-to-drag ratio. The focus will be laid upon designing and modeling of a sharp-edge stealthy re-entry vehicle by analyzing of lift-to-drag ratio and center of gravity, and also upon stealth performance researches. All aerodynamic performance analysis are based on Modified Newtonian Theory, it's proved to be more precise for a sharp-edge hypersonic re-entry vehicle relative to the Piston Theory and Shock-Expansion Method. A procedure based on physical optics and method of equivalent currents for radar cross section calculation. As result, the configuration and the center of gravity are determined, and a good stealth performance is demonstrated.

Background Frameless stereotactic neuronavigation has proven to be a feasible technology to acquire brain biopsies with good accuracy and little morbidity and mortality. New systems are constantly introduced into the neurosurgical armamentarium, although few studies have actually evaluated and compared the diagnostic yield, morbidity, and mortality of various manufacturer’s frameless neuronavigation systems. The present study reports our experience with brain biopsy procedures performed using both the Medtronic Stealth TreonTM Vertek® and BrainLAB® Varioguide frameless stereotactic brain biopsy systems. Patients and methods All 247 consecutive biopsies from January 2008 until May 2013 were evaluated retrospectively. One hundred two biopsies each were performed using the Medtronic (2008–2009) and BrainLAB® system (2011–2013), respectively. The year 2010 was considered a transition year, in which 43 biopsies were performed with either system. Patient demographics, perioperative characteristics, and histological diagnosis were reviewed, and a comparison was made between the two brain biopsy systems. Results The overall diagnostic yield was 94.6 %, i.e., 11 biopsies were nondiagnostic, 5 (4.9 %) with the Medtronic and 6 (5.9 %) with the BrainLAB® system. No differences besides the operating time (108 vs 120 min) were found between the two biopsy methods. On average, 6.6 tissue samples were taken with either technique. Peri- and postoperative complications were seen in 5.3 % and 12.9 %, consisting of three symptomatic hemorrhages (1.2 %). Biopsy-related mortality occurred in 0.8 % of all biopsies. Conclusions Regarding diagnostic yield, complication rate, and biopsy-related mortality, there seems to be no difference between the frameless biopsy technique from Medtronic and BrainLAB®. In contemporary time, the neurosurgeon has many tools to choose from, all with a relatively fast learning curve and ever improving feasibility. Thus, the issue of choice involves not the results, but the familiarity, end-user friendliness, and overall comfort when operating the system.