126 research outputs found
Electromechanical wavelength tuning of double-membrane photonic crystal cavities
We present a method for tuning the resonant wavelength of photonic crystal
cavities (PCCs) around 1.55 um. Large tuning of the PCC mode is enabled by
electromechanically controlling the separation between two parallel InGaAsP
membranes. A fabrication method to avoid sticking between the membranes is
discussed. Reversible red/blue shifting of the symmetric/anti-symmetric modes
has been observed, which provides clear evidence of the electromechanical
tuning, and a maximum shift of 10 nm with < 6 V applied bias has been obtained.Comment: 9 pages, 3 figure
Electromechanical tuning of vertically-coupled photonic crystal nanobeams
We present the design, the fabrication and the characterization of a tunable
one-dimensional (1D) photonic crystal cavity (PCC) etched on two
vertically-coupled GaAs nanobeams. A novel fabrication method which prevents
their adhesion under capillary forces is introduced. We discuss a design to
increase the flexibility of the structure and we demonstrate a large reversible
and controllable electromechanical wavelength tuning (> 15 nm) of the cavity
modes.Comment: 11 pages, 4 figure
Livestock Wastes Sustainable Use and Management: Assessment of Raw Sheep Wool Reuse and Valorization
Worldwide, around 998 million tons of agricultural waste are generated yearly, including livestock wastes, which create several critical environmental issues if not properly treated. In this study, a Geographical Information System (GIS)-based model to locate and quantify both the yearly amount of livestock waste, i.e., sheep wool, and the territorial distribution of sheep farms, was carried out and applied within the selected study area. The aim was to identify those territorial areas most suitable for localizing new shared wool collection centers to sustainably manage the reuse of this waste as potential green building material. Data related to both sheep farms and sheep number and the related sheep shared wool (SSW) yearly production were acquired and applied in GIS. By GIS-based model results, two collection centers have been identified within the provinces of Agrigento and Enna. Then, to develop a sustainable reuse in terms of reducing environmental impact due to the SSW logistics and supply phase, a possible third collection center was localized within the territorial area belonging to the province of Ragusa (south area of the Sicily). In this research, for the first time the issue above reported was addressed, by achieving results that contribute at developing an efficient collection chain for recovering and properly reusing SSW to respond adequately to a further industrial scale production
Single-photon nonlinear optics with a quantum dot in a waveguide
Strong nonlinear interactions between photons enable logic operations for
both classical and quantum-information technology. Unfortunately, nonlinear
interactions are usually feeble and therefore all-optical logic gates tend to
be inefficient. A quantum emitter deterministically coupled to a propagating
mode fundamentally changes the situation, since each photon inevitably
interacts with the emitter, and highly correlated many-photon states may be
created . Here we show that a single quantum dot in a photonic-crystal
waveguide can be utilized as a giant nonlinearity sensitive at the
single-photon level. The nonlinear response is revealed from the intensity and
quantum statistics of the scattered photons, and contains contributions from an
entangled photon-photon bound state. The quantum nonlinearity will find
immediate applications for deterministic Bell-state measurements and
single-photon transistors and paves the way to scalable waveguide-based
photonic quantum-computing architectures
From Parental Bonding to Problematic Gaming: The Mediating Role of Adult Attachment Styles
Background: Research has found that parental failures of care during childhood and insecure attachment styles are positively associated with problematic gaming. From a developmental framework, it is possible to hypothesize that attachment styles mediate the relationship between parental bonding and problematic gaming. Methods: This hypothesis was tested in a sample of 598 videogame players (410 males, 68.56%) aged between 18 and 61 years old (M = 26.68, SD = 7.23). Participants were recruited through an online survey. Self-report instruments were administered to assess problematic gaming, parental bonding, and adult attachment styles. Results: Positive paternal care was a direct and negative predictor of problematic gaming, whereas maternal overprotection indirectly predicted problematic gaming through preoccupied attachment. Conclusions: These findings suggest that positive paternal care represents a protective factor for problematic gaming; in contrast, maternal overprotection might foster a negative view of the self in the child, which increases the risk to excessively use videogames, perhaps as a maladaptive coping strategy to regulate negative feelings. Prevention programs might be aimed to improve the responsiveness of parents towards the child’s emotional needs, to prevent the development of problematic gaming. Also, clinical intervention with problematic gamers might foster their feelings of security toward relationships, to promote both a healthier use of videogames and a better quality of life
Ultrafast nonlocal control of spontaneous emission
Solid-state cavity quantum electrodynamics systems will form scalable nodes
of future quantum networks, allowing the storage, processing and retrieval of
quantum bits, where a real-time control of the radiative interaction in the
cavity is required to achieve high efficiency. We demonstrate here the dynamic
molding of the vacuum field in a coupled-cavity system to achieve the ultrafast
nonlocal modulation of spontaneous emission of quantum dots in photonic crystal
cavities, on a timescale of ~200 ps, much faster than their natural radiative
lifetimes. This opens the way to the ultrafast control of semiconductor-based
cavity quantum electrodynamics systems for application in quantum interfaces
and to a new class of ultrafast lasers based on nano-photonic cavities.Comment: 15 pages, 4 figure
Health technology assessment of pathogen reduction technologies applied to plasma for clinical use
Although existing clinical evidence shows that the transfusion of blood components is becoming increasingly safe, the risk of transmission of known and unknown pathogens, new pathogens or re-emerging pathogens still persists. Pathogen reduction technologies may offer a new approach to increase blood safety. The study is the output of collaboration between the Italian National Blood Centre and the Post-Graduate School of Health Economics and Management, Catholic University of the Sacred Heart, Rome, Italy. A large, multidisciplinary team was created and divided into six groups, each of which addressed one or more HTA domains.Plasma treated with amotosalen + UV light, riboflavin + UV light, methylene blue or a solvent/detergent process was compared to fresh-frozen plasma with regards to current use, technical features, effectiveness, safety, economic and organisational impact, and ethical, social and legal implications. The available evidence is not sufficient to state which of the techniques compared is superior in terms of efficacy, safety and cost-effectiveness. Evidence on efficacy is only available for the solvent/detergent method, which proved to be non-inferior to untreated fresh-frozen plasma in the treatment of a wide range of congenital and acquired bleeding disorders. With regards to safety, the solvent/detergent technique apparently has the most favourable risk-benefit profile. Further research is needed to provide a comprehensive overview of the cost-effectiveness profile of the different pathogen-reduction techniques. The wide heterogeneity of results and the lack of comparative evidence are reasons why more comparative studies need to be performed
A proposal for limited criminal liability in high-accuracy endoscopic sinus surgery
Lo studio ha lo scopo di sollecitare una riforma della responsabilità penale che preveda una riduzione di responsabilità legale per la chirurgia ad alta precisione, per quella ad alto rischio, come per esempio la chirurgia endoscopica sinusale (ESS). Il contributo comprende una revisione della letteratura medica, concentrandosi sullidentificazione e sullesame dei motivi per cui la tecnica di ESS corre un rischio molto elevato di produrre gravi complicazioni dovute a manovre chirurgiche inesatte. Tale contributo, prevede anche una revisione della teoria del diritto e della giurisprudenza britannica e italiana in merito alla negligenza medica, soprattutto con riferimento alla L. italiana n. 189 del 2012 (Decreto Balduzzi). Si è constatato che gravi complicanze dovute a manovre chirurgiche non corrette di ESS possono verificarsi, indipendentemente dalla prudenza/diligenza del chirurgo. La soggettività in termini giuridici risulta essenziale per la negligenza medica, soprattutto con riferimento alla chirurgia ad alta precisione. La legge italiana 189/2012 rappresenta una buona base per la limitazione della responsabilità penale derivante da manovre imprecise in chirurgia ad alta precisione, come appunto lESS. In conclusione, si considera che i chirurghi che eseguono ESS dovrebbero essere esonerati da responsabilità penale in caso di negligenza lieve sopravvenuta nonostante il rispetto delle line guida emanate
A chip-scale integrated cavity-electro-optomechanics platform
We present an integrated optomechanical and electromechanical nanocavity, in
which a common mechanical degree of freedom is coupled to an ultrahigh-Q
photonic crystal defect cavity and an electrical circuit. The sys- tem allows
for wide-range, fast electrical tuning of the optical nanocavity resonances,
and for electrical control of optical radiation pressure back-action effects
such as mechanical amplification (phonon lasing), cooling, and stiffening.
These sort of integrated devices offer a new means to efficiently interconvert
weak microwave and optical signals, and are expected to pave the way for a new
class of micro-sensors utilizing optomechanical back-action for thermal noise
reduction and low-noise optical read-out.Comment: 11 pages, 7 figure
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