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From 2007–2012, a dramatic upsurge in maritime piracy off the coast of Somalia captivated global attention. Over three hundred merchant vessels and some three thousand seafarers were held hostage with ransom amounts ranging from $200,000 to $10 million being paid to release these ships. Somali piracy operated exclusively on a kidnap-and-ransom model with crew, cargo, and ship held captive until a ransom was secured. Ransom, unlike theft or seizure, requires willing parties and systems of exchange. Ransom economies, therefore, bring together disparate actors and make visible the centrality of protection as a mode of accumulation and jurisdiction. As an analytic, this article proposes an anthropology of protection to undercut divides between legality and illegality, trade and finance, piracy and counter piracy. It argues that protection is key to apprehending processes of mobility and interruption central to global capitalism.
Amorphous Si (a-Si) is used for fabrication of commercial low-cost flat panel image detectors for radiographic applications such as computed tomography (CT) imaging. a-Si photodiodes are known to exhibit a rapid decrease in quantum efficiency near 750nm. While crystalline Si does not suffer from such an early decline, the large-area and low-cost constraints of medical imagers make it challenging and costly to use crystalline Si for such devices. In this work, we report on the development of a sensitive layer for upconversion from 785 nm to green region of the spectrum, which nearly matches the peak quantum efficiency of a-Si detectors. Various host materials have been extensively studied in literature with rare earth ions such as Er3+(emission: green+red), Tm3+(emission: blue), Ho3+(emission: red+green) along with Yb3+ as a sensitizer for upconversion to the visible regime at high incident optical power (∼100 mW) for colloidal solutions. We carried out a thermal decomposition synthesis of NaYF4:Yb(18%),Er(2%),Gd(15%) at moderate temperature (∼320°C), resulting in a nearly pure hexagonal phase material. This is confirmed by powder X-ray diffraction (PXRD) of the unannealed sample with a lattice constant (∼5.17 Å). High-resolution transmission electron microscopy (HRTEM) measurements reveal the formation of nearly spherical nanoparticles. The observed plane () inferred from lattice fringes in TEM data with a visibly estimated interplanar distance (4.4±1.6 Å) is in reasonable agreement with standard data (∼5.17 Å) for comparable NaYF4-based materials. Excitation (785 nm) of the deposited thin films of Gd-doped unannealed material at relatively low incident power (∼0.4 mW) exhibits a PL response in green (539 nm) and red (665 nm) region of the spectrum. Gd-based upconversion material based thin films are thus a feasible photonic material for potential effective extension of high quantum efficiency range in a-Si for flat panel image detectors.
This paper presents performances achieved with InAlGaN/GaN HEMTs with 0.15 µm gate length on SiC substrate. Technology Computer Aided Design simulations were used to optimize the heterostructure. Special attention was paid to the design of the buffer structure. I-V measurements with DC and pulsed bias voltages were performed. CW measurements at millimeter waves were also carried out and are detailed in the following sections. The technology, optimized for power applications up to 45 GHz, demonstrates a current gain cut-off frequency FT of 70 GHz and a maximum available gain cut-off frequency FMAG of 140 GHz. CW Load-pull power measurements at 30 GHz enable to achieve a maximum PAE of 41% associated with an output power density of 3.5 W/mm when biased at VDS = 20 V. These devices, with an improved buffer structure show, reduced recovery time in pulsed operating conditions. These improved characteristics should have a positive impact for pulsed or modulated signal applications.
According to Reinhart and Rogoff (2009), financial crises are essentially triggered by a collapse of investor confidence, especially in the case of highly leveraged financial markets. Economists believe that the introduction of more innovative financial instruments aimed at increasing the depth of the markets along with flexible monetary policy could contain the risk of occurrence of financial crises, as these could tackle the underlying business cycle downturns. However, the ‘subprime financial crisis’ that started in the US in 2007 could not be tamed and led to a recession in the largest economy of the world. Further, it snowballed into a global financial crisis, which had a cascading effect on financial markets around the world in 2008 and triggered the ‘Second Great Contraction’ in many economies.
The global recession was extraordinary due to its massive coverage, extreme severity, long duration and huge repercussion effects.
From Figure 6.1a, we observe that the gross government debt of the US was in the range of 60–70 per cent of the GDP till 2007. However, in a bid to revive the economy post the crisis, the US government resorted to fiscal expansion, which worsened the exchequer as the gross government debt soared to more than 100 per cent in 2012–2013. Current account balance (Figure 6.1b) of the US had been deteriorating till 2006. However, due to a dampening of the demand for exports in the face of a recession in the US economy, the current account balance steadily improved since 2007 and now stands at less than 3 per cent of the GDP. Unemployment rate (Figure 6.1c) peaked in the aftermath of the crisis to about 9.6 per cent in 2010, but stood at about 7 per cent in 2013. Figure 6.1d depicts the growth rate of GDP in the US and shows that the growth rate was negative during 2008–2010 and according to the latest data stands at about 2 per cent in 2013. US being the largest economy of the world, the impact of the global recession of 2008–2009 crisis was widespread with several countries of the world tumbling into a recession. This subsequently strained governments around the world as they had to overstretch in an attempt to tackle the real effects of the crisis on their economies by undertaking fiscal expansion.
In recent years a number of intergovernmental initiatives have been activated in order to enhance the capacity of countries to improve access to essential medicines, particularly for mental disorders. In May 2013 the 66th World Health Assembly adopted the World Health Organization (WHO) Comprehensive Mental Health Action Plan 2013–2020, which builds upon the work of WHO's Mental Health Gap Action Programme. Within this programme, evidence-based guidelines for mental disorders were developed, including recommendations on appropriate use of medicines. Subsequently, the 67th World Health Assembly adopted a resolution on access to essential medicines, which urged Member States to improve national policies for the selection of essential medicines and to promote their availability, affordability and appropriate use.
Following the precedent set by these important initiatives, this article presents eleven actions for improving access and appropriate use of psychotropic medicines.
A 4 × 4 framework mapping actions as a function of the four components of access – selection, availability, affordability and appropriate use – and across four different health care levels, three of which belong to the supply side and one to the demand side, was developed. The actions are: developing a medicine selection process; promoting information and education activities for staff and end-users; developing a medicine regulation process; implementing a reliable supply system; implementing a reliable quality-control system; developing a community-based system of mental health care and promoting help-seeking behaviours; developing international agreements on medicine affordability; developing pricing policies and a sustainable financing system; developing or adopting evidence-based guidelines; monitoring the use of psychotropic medicines; promoting training initiatives for staff and end-users on critical appraisal of scientific evidence and appropriate use of psychotropic medicines.
Activating these actions offers an unique opportunity to address the broader issue of increasing access to treatments and care for mental disorders, as current lack of attention to mental disorders is a central barrier across all domains of the 4 × 4 access framework.
This paper presents an original characterization method of trapping phenomena in gallium nitride high electron mobility transistors (GaN HEMTs). This method is based on the frequency dispersion of the output-admittance that is characterized by low-frequency S-parameter measurements. As microwave performances of GaN HEMTs are significantly affected by trapping effects, trap characterization is essential for this power technology. The proposed measurement setup and the trap characterization method allow us to determine the activation energy Ea and the capture cross-section σn of the identified traps. Three original characterizations are presented here to investigate the particular effects of bias, ageing, and light, respectively. These measurements are illustrated through different technologies such as AlGaN/GaN and InAlN/GaN HEMTs with non-intentionally doped or carbon doped GaN buffer layers. The extracted trap signatures are intended to provide an efficient feedback to the technology developments
Mortality-associated burden of disease estimates from the Global Burden of Disease 2010 (GBD 2010) may erroneously lead to the interpretation that premature death in people with mental, neurological and substance use disorders (MNSDs) is inconsequential when evidence shows that people with MNSDs experience a significant reduction in life expectancy. We explore differences between cause-specific and excess mortality of MNSDs estimated by GBD 2010.
GBD 2010 cause-specific death estimates were produced using the International Classification of Diseases death-coding system. Excess mortality (all-cause) was estimated using natural history models. Additional mortality attributed to MNSDs as underlying causes but not captured through GBD 2010 methodology is quantified in the comparative risk assessments.
In GBD 2010, MNSDs were estimated to be directly responsible for 840 000 deaths compared with more than 13 million excess deaths using natural history models.
Numbers of excess deaths and attributable deaths clearly demonstrate the high degree of mortality associated with these disorders. There is substantial evidence pointing to potential causal pathways for this premature mortality with evidence-based interventions available to address this mortality. The life expectancy gap between persons with MNSDs and the general population is high and should be a focus for health systems reform.
This paper presents power results of L-band packaged hybrid amplifiers using InAlN/GaN/SiC HEMT power dies. The high-power densities achieved both in pulsed and continuous wave (cw) modes confirm the interest of such technology for high-frequency, high-power, and high-temperature operation. We present here record RF power measurements for different versions of amplifiers. Up to 260 W, i.e. 3.6 W/mm, in pulsed (10 µs/10%) conditions, and 105 W, i.e. 2.9 W/mm, in cw conditions were achieved. Such results are made possible thanks to the impressive performances of InAlN/GaN transistors, even when operating at high temperatures. Unit cell transistors deliver output powers of 4.3 W/mm at Vds = 40 V in the cw mode of operation at the frequency of 2 GHz. The transistor process is described here, as well as the amplifiers design and measurements, with a particular focus to the thermal management aspects.
Law has been a little slow off the mark in the UK when it comes to the world of mobile applications (apps). In an environment where students spend more time using mobile applications than they do browsing the internet, the authors were keen to take their Learnmore website to the next stage by developing an app for law students. The Learnmore website (part of the Lawbore suite of resources from City University) has received much attention for its quirky visuals, multimedia learning tools and winning marriage of librarian and student generated content. With an ultimate aim of easing the transition between A-levels and degree and making the ‘building blocks’ of legal skills more interesting. Emily and Sanmeet secured substantial funding from JISC after a call for universities to create mobile apps from existing content, teaming up with a colleague in City University's Human Computer Interaction and Design department. The app was to be designed to help students learn essential legal skills in an innovative way, employing more interaction than was possible via the web. The emphasis on video content meant an early decision to fix on iPad rather than iPhone as the tool for mobile learning. The JISC funding paid for the services of a developer to help bring their ideas to life. This paper looks at the transformation from standard wiki to mobile application; focusing on the process of developing the concept for the app and the major milestones, as well as providing an insight into the expected challenges along the way. These included: working in a multidisciplinary team, communication of ideas, recognising the differences required in design for an app as opposed to a website and managing conflicting visions. The team motto was that creating an app cannot be simply a re-skinning process; but a re-working of content to to ensure a truly effective learning resource.
The present paper presents an overview of the AlGaN/GaN-based circuits realized over the years. Two technological processes with 0.25 and 0.7 μm gate length allowed one to address applications from L- to Ku-bands. Depending on the process development and frequency of the operation, results on hybrid or MMIC technology are presented. GaN technology is evaluated through the realization of high-power amplifiers, robust low-noise amplifiers, or power switches to prepare the next generation of Tx-Rx modules.
Titanium nitride (TiN) is a candidate material for hard and wear resistant coatings on metallic substrates such as titanium (Ti), stainless steel and aluminum. Coating processes include chemical vapor deposition, ion implantation, plasma and thermal nitriding under vacuum and controlled environments. The motivation for the present research is to develop a laser plasma process for high rate formation of TiN coatings on Ti substrates at near-atmospheric pressures. Laser induced plasma generated by a pulsed CO2 laser was used to excite a Ti substrate. The species in the vapor plume were characterized by optical emission spectroscopy. Spatially and temporally resolved spectral characterization was performed as a function of laser power, position of the substrate relative to the focal plane, pulse parameters, and shielding gases. These experiments are a first step in understanding laser assisted plasma deposition of nitride/oxy-nitride coatings on titanium metal under atmospheric conditions. Results indicate a window of optimal process parameters for developing titanium nitride coatings.
High power RF device performance
decreases as operation temperature increases (e.g. decreasing electron
mobility affects cut-off frequencies and degrades device reliability).
Therefore determination of device temperature is a key issue for device
topology optimisation. In this work the temperature variation of AlGaN/GaN
high-electron-mobility transistors grown either on silicon or sapphire
substrate under bias operation was measured by micro Raman scattering
spectroscopy. Temperature measurements up to power dissipation of 16 W for
4 mm development devices were carried out and a peak temperature of 650 K was
determined. The difference of thermal resistance for similar devices grown
on the two different substrates was assessed. The thermal resistances of
different device topologies were compared to optimise the component design.
Brain injuries are a serious burden of illness to Canada and the US. Advances in managing head trauma have allowed more patients to emerge from decreased levels of consciousness and helped them cope with neurocognitive, neurobehavioural, and neuropsychiatric deficits. In this article, we review the current (1986-2002) evidence surrounding the pharmacological management of arousal states and the aforementioned neurological sequelae of head injury in either acute or chronic conditions. This article will review the evidence for the use of psychostimulants (methylphenidate), antidepressants (amitriptyline, selective serotonin reuptake inhibitors, and buproprion), Parkinson’s medications (amantadine, bromocriptine, carbidopa/levodopa), anticonvulsants (valproic acid), modafinil (Provigil), lactate, hyperbaric oxygen chamber, electroconvulsive therapy, and transmagnetic stimulation, in patients following a head injury. The review did not include all anticonvulsants, neuroleptics, beta-blockers, benzodiazepines, azospirones or cognitive enhancers. Unfortunately, the quality of the evidence is generally poor, and sometimes conflicting, which in turn results in indecisive guidelines for treating patients. Accepting the inherent flaws in the evidence we feel that this paper may serve as a stepping-stone for future researchers to improve data gathering that targets neurocognitive, neurobehavioural and neuropsychiatric symptoms following a head injury.
We have studied the influence of a deuterium diffusion on the electrical characteristics of the 2D gas present in AlGaN/GaN heterostructures. The deuterium diffusion is performed by exposing the structures to a rf remote deuterium plasma. We find that both the sheet carrier concentration and the electron mobility decrease and that these effects are partly reversible under thermal annealing. These results suggest that deuterium behave as acceptors in the 2D gas region. The negatively charged deuterium act as additional scattering centers for electrons.
The high power RF device performance decreases as the operation
temperature increases (e.g. fall of electron mobility impacting
the cut-off frequencies and degradation of device reliability).
Therefore the determination of device temperature is a key issue
for device topology optimisation. In this work the temperature
variation of AlGaN/GaN high-electron-mobility transistors grown
either on silicon or sapphire substrates under bias operation was
measured by micro Raman scattering spectroscopy. The differences
in thermal resistance for similar devices grown on the two
different substrates were assessed. The thermal resistances of
different device topologies were compared in order to optimise
the component design. The temperature measurement across the gate
and along the component fingers were made to quantify the thermal
gradient of the device. Temperature measurement up to a power
dissipation of 16 W for a 4 mm development device was carried out
and the peak temperature of 650 K was determined.