Quantum information processing by nuclear magnetic resonance on quadrupolar nuclei

Nuclear magnetic resonance is viewed as an important technique for the implementation of many quantum information algorithms and protocols. Although the most straightforward approach is to use the two-level system composed of spin 1/2 nuclei as qubits, quadrupolar nuclei, which possess a spin greater than 1/2, are being used as an alternative. In this study, we show some unique features of quadrupolar systems for quantum information processing, with an emphasis on the ability to execute efficient quantum state tomography (QST) using only global rotations of the spin system, whose performance is shown in detail. By preparing suitable states and implementing logical operations by numerically optimized pulses together with the QST method, we follow the stepwise execution of Grover's algorithm. We also review some work in the literature concerning the relaxation of pseudo-pure states in spin 3/2 systems as well as its modelling in both the Redfield and Kraus formalisms. These data are used to discuss differences in the behaviour of the quantum correlations observed for two-qubit systems implemented by spin 1/2 and quadrupolar spin 3/2 systems, also presented in the literature. The possibilities and advantages of using nuclear quadrupole resonance experiments for quantum information processing are also discussed.     

Optomechanics with silicon nanowires by harnessing confined electromagnetic modes

The optomechanical coupling that emerges in an optical cavity in which one of the mirrors is a mechanical resonator has allowed sub-Kelvin cooling with the prospect of observing quantum phenomena and self-sustained oscillators with very high spectral purity. Both applications clearly benefit from the use of the smallest possible mechanical resonator. Unfortunately, the optomechanical coupling largely decays when the size of the mechanical system is below the light wavelength. Here, we propose to exploit the optical resonances associated to the light confinement in subwavelength structures to circumvent this limitation, efficiently extending optomechanics to nanoscale objects. We demonstrate this mechanism with suspended silicon nanowires. We are able to optically cool the mechanical vibration of the nanowires from room temperature to 30-40 K or to obtain regenerative mechanical oscillation with a frequency stability of about one part per million. The reported optomechanical phenomena can be exploited for developing cost-optimized mass sensors with sensitivities in the zeptogram range.     

Theoretical study of a membrane reactor for the water gas shift reaction under nonisothermal conditions

A simulation of a membrane reactor for the water gas shift reaction is carried out by means of a 1D pseudo‐homogeneous nonisothermal mathematical model. The composite membrane consists of a dense layer of Pd (selective to H₂) supported over a porous ceramic layer. The effect of temperature, overall heat‐transfer coefficient, and mode of operation on the membrane reactor performance and stability are analyzed, and the results obtained are compared with those corresponding to a reactor with no hydrogen permeation. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Computational Study of the Lipase‐Mediated Desymmetrisation of 2‐Substituted‐Propane‐1,3‐Diamines

The enantioselectivity displayed by the lipase from Pseudomonas cepacia towards a wide range of prochiral 2‐substituted‐propane‐1,3‐diamines was studied by means of molecular dynamics simulations (MDS). In all cases the enzyme allows the recovery of the corresponding amino carbamates of R configuration. However, the enantioselectivity is only synthetically useful if no ortho substituent is present and the aromatic ring is directly bonded to the 2‐carbon of the 1,3‐diamine core. Analysis of the MDS trajectories revealed that the homologation of 2‐aryl substituents by means of a methylene group lowers enantioselectivity by alleviating the conformational tension of the slow‐reacting orientations due to unfavourable intramolecular contacts between the ortho carbons of the aryl group and the nucleophilic nitrogen, as well as between the chiral carbon and the oxyanion. Additionally, the relative solvent accessible surfaces of the atoms of the aryl ring nicely correlate with the effect of the location of the substituent on enantioselectivity.     

Preparation and characterization of silicate nanofilms doped with europium β-diketonate complexes

Films consisting of Eu³⁺ β-diketonate complexes were deposited onto glassy substrates by means of the spin- and dip-coating techniques, using different ion/ligand ratios. Absorption spectroscopy in the infrared region revealed the typical stretching bands of the SiOSi and SiOH bonds of the inorganic matrix as well as bands relative to the CO and CH symmetric vibration of β-diketone (dibenzoylmethane). The films displayed UV-visible absorption band at 350 nm, attributed to the organic ligand. Luminescence properties were studied by photoluminescence spectroscopy. Upon ligand excitation, the emission spectra exhibited the characteristic bands of the Eu³⁺ ion corresponding to the transition from the excited state ⁵D₀ to the ground state ⁷F_J. Scanning electron microscopy confirmed the formation of a film with average thickness ranging from 80 to 100 nm. The sol-gel process and the deposition techniques resulted in the effective formation of nanofilms, which opens up perspectives for their application in photonics.     

GIS applied to geotechnical and environmental risk management in a Brazilian oil pipeline

The paper presents the development of a decision support system for the management of geotechnical and environmental risks in oil pipelines using a geographical information system. The system covers a 48.5 km long section of the São Paulo to Brasília (OSBRA) oil pipeline, which crosses three municipalities in the northeast region of the São Paulo state (Brazil) and represents an area of 205.8 km². The spatial database was created using geo-processing procedures, surface and intrusive investigations and geotechnical reports. The risk assessment was based mainly on qualitative models (relative numeric weights and multicriteria decision analysis) and considered pluvial erosion, slope movements, soil corrosion and third party activities. The maps were produced at a scale of 1:10,000.     

Geometrical Kernel Machine for Prediction and Novelty Detection of Disruptive Events in TOKAMAK Machines

With the wide adoption of internet into our everyday lives, internet security becomes an important issue. Intrusion detection at the network level is an effective way of stopping malicious attacks at the source and preventing viruses and worms from wide spreading. The key component in a successful network intrusion detection system is a high performance pattern matching engine that can uncover the malicious activities in real time. In this paper, we propose a highly parallel, scalable hardware based network intrusion detection system, that can handle variable pattern length efficiently and effectively. Pattern matching for a packet is completed in O(N log M) time where N is the size of the packet and M is the longest pattern length. Implementation is done on a standard off-the-shelf field-programmable gate array. Comparison with the other techniques shows promising results.     

Selenium,iodine, ω-3 PUFA and natural antioxidant from Melissa officinalis L.: A combination of components from healthier dry fermented sausages formulation

A new formulation of dry fermented sausage, including ingredients that improve the nutritional and health benefits of this type of product is presented. Se yeast (2 g/kg), iodized salt (26 g/kg), linseed:algae (3:2) emulsion (62.5 g/kg), and lyophilized water extract of Melissa officinalis L. as a source of natural antioxidants (686 mg/kg), yielded dry fermented sausages with technological and sensory properties similar to traditional ones.     

Identification of key odor volatile compounds in the essential oil of nine peach accessions

BACKGROUND: Volatile compounds, together with sugars and acids, are the main chemical species determining the characteristic aroma and flavor of food. In peach, more than 100 volatiles have been identified. RESULTS: The essential oil of six peach and three nectarine accessions used in Italian breeding programs was obtained by steam distillation, and the volatiles were investigated. A total of 47 known volatiles, two unidentified compounds and nine hydrocarbons were identified, including 12 aldehydes, six alcohols, three acids, three esters, six terpenes, two phenylalanine derivates, two C₁₃ norisoprenoids, one ketone (C₉) and 10 lactones. A wide variation in the number of volatiles and in their concentration was observed among the nine accessions. Twenty‐one compounds presented odor activity values (OAVs) higher than 1 in at least one of the accessions and were therefore putatively considered as key odorants in the peach volatile composition. CONCLUSION: This study reports the identification, quantification and potency, based on the OAVs, of the most important volatile compounds, along with fruit quality characteristics, of nine different peach/nectarine accessions and will help future peach volatile breeding programs for the selection of odor‐rich accessions to be used in the development of new improved cultivars. Copyright © 2010 Society of Chemical Industry     

Myosin heavy chain fibre types and fibre sizes in nuliparous and primiparous ovariectomized Iberian sows: Interaction with two alternative rearing systems during the fattening period

To investigate the effects of the reproductive background (nuliparous/primiparous) on skeletal muscle phenotype and their interaction with two alternative finishing systems (indoors/outdoors) in Iberian sows, 32 contemporary piglets were assigned to four different groups: indoors-nuliparous, indoors-primiparous, outdoors-nuliparous and outdoors-primiparous. Nuliparous sows were ovariectomized at 4 months of age, whereas primiparous were castrated at 14 months of age, after their first lactation. Indoors sows were fattened (2 months prior to slaughter) intensively, whereas outdoors sows were finished in an extensive land with natural resources. Muscle samples (semimembranosus, gluteobiceps) were analyzed for myosin fibre types and fibre sizes. Sows finished out-of-doors had more type I and IIA fibres and smaller fibres than indoor-fattened pigs. Primiparous reared indoors had a significantly lower IIX:IIB fibre ratio and showed a clear tendency for having larger fibres than nuliparous reared indoors. Reproductive background effect interacted with rearing condition effect inducing relevant muscular adaptations. Thus, the influence of reproductive background on muscle characteristics was not significant in sows reared out-of-doors but highly significant in sows finished intensively. This interaction resulted in muscular traits less favourable for meat quality in primiparous vs. nuliparous reared indoors.