Effects of electrical and mechanical stunning methods on meat quality in ostriches

The effect of electrical and captive needle air pressure stunning methods on some meat quality parameters was examined in ostriches under practical conditions. One hundred and fifteen ostriches were used in three experiments. The ostriches were stunned either electrically (head only) or by using a captive needle with air pressure. In the first experiment the ostriches were stunned at 90 V (～effectively 52 V), 200 V and by captive needle using air pressure. In the second experiment voltages of 175 and 200 V were applied and a captive needle stunning method using air pressure. In the third experiment the birds were stunned at 175 V with a short stun/stick interval. Experiments 2 and 3 were performed in a different slaughterhouse from experiment 1. Meat quality was assessed by measuring the pH, temperature and colour at 45 min and 18 h post mortem and by determining water binding capacity and haemorrhage score at 18 h post mortem in the big drum, tender loin and triangular filet muscles. The measured stunning parameters in the first experiment were 204±96 mA (～52 V) during 11±1 s and 556±85 mA (～200 V) during 6±0 s. The stun/stick interval was 136±38 s. The rigor mortis value in the tender loin and both pH(1) and pH(2) in the big drum, tender loin and triangular filet muscles were (p<0.05) lower when stunned with air pressure compared with electrical stunning. Moreover internal light scattering remained higher. The measured currents in the second experiment were 561±226 mA (～173 V) during 6±2 s and 518±120 mA (～200 V) during 6 s. The stun/stick interval was 39±12 s. The pH at 45 min and 18 h differed (p<0.05) in the tender loin and triangular filet muscles as did the temperature at 45 min in the three muscles between the different stunning groups. The stunning in the third experiment was carried out with 548±180 mA during 6±2 s. The stun/stick interval was 5±2 s. After the short stun/stick interval the pH(2) was lower (p<0.05) for the tender loin and triangular filet muscles and the wetness of the filter paper of the big drum was (p<0.05) lower compared with the other groups. Our experiments showed that stunning methods affected several meat quality parameters. Using a high electrical stunning current, captive needle stunning or a short stun/stick interval may positively affect some parameters. More research is necessary to examine effects of pre slaughter handling on meat quality.     

Dispersion in finlines on semiconductor and the S-parameters of a step discontinuity

The Transverse Transmission Line method is used for the characterization of bilateral and unilateral finlines on a semiconductor substrate and in conjunction with the modal method, for the calculation of the scattering parameters due to a step discontinuity on a unilateral finline with a lossless dielectric substrate. Numerical results of the effective dielectric constant, attenuation constant and characteristic impedance for the bilateral and unilateral finlines on semiconductor substrates, and results of scattering parameters of a step discontinuity for unilateral finline, are presented.     

基于可调谐式RS-POTDR实现已安装光纤累积PMD分布的测量

本文描述了一种新的偏振敏感OTDR方法,其非常适用于对已安装的光纤链路(可包含多种不同单模光纤类型)的累积PMD进行定量分布测量.通过这种方法,可以确定PMD较高的光纤区域,并且可以在必要的情况下替换该区域光纤,从而以经济有效的方法降低链路PMD.     

Sur l’utilisation des équations intégrales en régime transitoire dans les problèmes d’électromagnétisme

It is possible in many cases by using space-time integral equations to compute the scattering and penetration of electromagnetic fields via explicit time-stepping diagrams. The case of conducting surfaces, thin scatterers, apertures and shieldings of finite conductivity are discussed with emphasis on the simplicity and the validity domain of the relevant equations. Examples concern the field of a far-located dipole incident on a cylinder with infinite conductivity, with an aperture or with resistive walls.     

A Multi-user Receiver for Inter-Cell Interference Reduction in LTE PUCCH Signaling

In 3rd generation partnership project (3GPP) long term evolution (LTE) systems, when no resources has been assigned in the uplink to a given user equipment (UE), the control information associated with layers 1 and 2 in the protocol stack is conveyed back to the base station through the so-called physical uplink control channel (PUCCH). In PUCCH, the data streams transmitted by multiple UEs are multiplexed in the time-domain and in the frequency-domain with the aid of spreading codes. Although the spreading codes associated with UEs within the same cell can be assumed to be orthogonal, the presence of inter-cell interference (ICI) in multi-cell scenarios severely limits receiver performance. In particular, the Format 1 of PUCCH, which is associated with the transmission of hybrid automatic repeat request acknowledgements (ACK/NACK) and scheduling requests, has a major impact on system performance, since an incorrectly decoded ACK/NACK message may introduce significant delay in data transmission. In this contribution, we propose a new multi-user receiver for ICI reduction in PUCCH LTE that operates both in cooperative and non-cooperative multi-cell architectures. The proposed receiver relies on a constrained tensor modeling of the received signal in PUCCH signaling, and affords an iterative joint channel estimation and symbol detection by simultaneously exploiting the energy of the data symbols and the pilot tones present in PUCCH. The formulation of the proposed algebraic receiver model incorporates symbol-basis hopping and slot-basis hopping signaling schemes, which are interference randomization techniques existing in the 3GPP specifications of LTE system. Computer simulation results show the remarkable performance gains of the proposed receiver compared to the conventional time-frequency decorrelator based receiver.     

Crystal Size,Morphology, and Growth Mechanism in Bio‐Inspired Apatite Nanocrystals

Bio‐inspired apatite nanoparticles precipitated in the presence of citrate ions at increasing maturation times are characterized in terms of structure, size, morphology, and composition through advanced X‐ray total scattering techniques. The origin of the platy crystal morphology, breaking the hexagonal symmetry, and the role of citrate ions is explored. By cross‐coupling the size and shape information of crystal domains with those obtained by atomic force microscopy on multidomain nanoparticles, a plausible mechanism underlying the amorphous‐to‐crystal transformation is reconstructed. In the present study, citrate plays the distinct roles of inducing the platy morphology of the amorphous precursor and controlling the thickness of the Ca‐deficient apatite nanocrystals. These findings can open new scenarios also in bone mineralization, where citrate might have a broader role to play than has been thought to date.     

SDN-based architecture for providing quality of service to high-performance distributed applications

The specification of quality of service (QoS) requirements in most of the existing networks is still challenging. In part, traditional network environments are limited by their high administrative cost, although software-defined networks (SDNs), a newer network paradigm, simplify the management of the whole network infrastructure. In fact, SDN provides a simple way to effectively develop QoS provisioning mechanisms. In this sense, we explore the SDN model and its flexibility to develop a QoS provisioning architecture. Through the use of our new architecture, network operators are able to specify QoS levels in a simple way. Each individual data flow can be addressed, and the architecture we propose also negotiates the QoS requirements between the network controller and applications. On the other hand, the network controller continuously monitors the network environment. Then, it allocates network elements resources and prioritizes traffic, adjusting the network performance. We evaluate the feasibility of our QoS provisioning mechanism by presenting three experimental setups under realistic scenarios. For example, for a given scenario where we evaluate file transfers, our results indicate that the additional SDN modules present negligible overhead. Moreover, for a given setup, we observe a reduction of up to 82% in the file transfer times.     

Impact of growth rate on the quality of ZNS-MQW InGaAsP/InP laser structures grown by LP-MOVPE

We investigated the influence of the growth rate on the quality of zero-net-strained InGaAsP/InGaAsP/InP multiquantum well structures for 1.55 μm emission grown by low pressure metalorganic vapor phase epitaxy. The samples consisted of fixed compressive strained wells (ɛ=+1%) and tensile strained barriers (ɛ=−0.5%) grown with different quaternary bandgap wavelengths (λ_B=1.1–1.4 μm). Using higher growth rates, we obtained for the first time high quality zero net strained multi quantum well structures, regardless having constant group V composition in the well and barriers. The samples were analyzed by x-ray diffraction, photoluminescence and atomic force microscopy techniques. The amplitude of surface modulation roughness along [011] direction decreased from 20 nm to 0.53 nm with increasing growth rate and/or quaternary compositions grown outside the miscibility gap. A new deep PL broad emission band strongly correlated with the onset of wavy layer growth is also reported. Broad area and ridge waveguide lasers with 10 wells exhibited low losses (34 cm⁻¹) and low threshold current densities at infinite cavity length (1020 A·cm⁻² and 1190 A·cm⁻², respectively).     

Probabilistic linear models for multiresolution estimation in gray-level images

A multiresolution analysis of digital gray-level images is presented. A gray-level multi-scale framework is determined from two main assumptions: the gray scale is binary at the finest spatial resolution, and the gray levels of composed regions are obtained additively. In order to interrelate the gray-level histograms of the same image at different resolutions, probabilistic linear models are developed, which are then applied for estimation. Linear-optimization theory is used as a way of constructing such models. A general procedure for image processing is sketched, based on gray-level estimation. A versatile algorithm for nonlinear filtering is derived. Some examples of prospective applications are given.This work was partially supported by grant TIC91-646 from the DGYCIT of the Spanish Government.     

CMOS inverters based positive type second generation current conveyor

A new versatile class AB low-voltage second generation current conveyor based on CMOS inverters operating in transconductance mode is presented in this letter. Against traditional design based on CCII+, the circuit is able to operate at low supply voltages and offers numerous advantages like class AB operation, large voltage and current swing, synthesis from digital inverters. Simulation results from a typical 0.35 μm CMOS process had demonstrated the circuit capability to operate at high frequency over wide voltage and wide current swings. The proposed circuit operation has been acted from measurements with the HEF4069UBP from Philips semiconductors [1].