The effect of grazing intensity and the presence of a forage legume on nitrogen dynamics in Brachiaria pastures in the Atlantic forest region of the south of Bahia, Brazil

It has been shown that with careful grazing management and addition of Pand K, but not N, fertilisers Brachiaria pastures are ableto maintain sustainable live weight gains over many years. However, standardon-farm practice, which generally involves high stocking rates, leads after afew years to pasture decline due mainly to N deficiency for grass regrowth. Togenerate an understanding of the mechanism of pasture decline and possiblemanagement options to mitigate this process, a study was performed in theAtlantic forest region of the south of Bahia state to study the N dynamics inpastures of Brachiaria humidicola subject to threedifferent stocking rates of beef cattle, with and without the presence of theforage legume Desmodium ovalifolium. Despite the fact thatthe C:N ratio of the deposited litter was high (60 to 70) the rate ofdecomposition was very rapid (k –0.07 gg^–1 day^–1) and annual rates of Nturnover through the litter pathway were between 105 and 170 kg Nha^–1 year^–1. In the grass-onlypasturesas stocking rate increased from 2 to 3 head ha^–1, N recycledinthe litter decreased by 11%, but a further increase to 4 headha^–1 decreased N recycling by 30% suggesting thatbeyonda certain critical level higher grazing stocking rates would lead to pasturedecline if there was no N addition. High stocking rates decreased theproportionof the legume in the sward, but at all rates the concentration of N in both thegreen and dead grass in the forage on offer and in the litter was higher in themixed sward. The presence of the legume caused a decrease in the C:N ratio ofthe microbial biomass while both soil N mineralisation and nitrificationincreased. This increased rate of turnover of the microbial biomass and thecontribution of N₂ fixation to the legume resulted in largeincreasesin the N recycled via litter deposition ranging from 42 to 155 kg Nha^–1 year^–1.     

Aligned texture map creation for pose invariant face recognition

In last years, Face recognition based on 3D techniques is an emergent technology which has demonstrated better results than conventional 2D approaches. Using texture (180° multi-view image) and depth maps is supposed to increase the robustness towards the two main challenges in Face Recognition: Pose and illumination. Nevertheless, 3D data should be acquired under highly controlled conditions and in most cases depends on the collaboration of the subject to be recognized. Thus, in applications such as surveillance or control access points, this kind of 3D data may not be available during the recognition process. This leads to a new paradigm using some mixed 2D-3D face recognition systems where 3D data is used in the training but either 2D or 3D information can be used in the recognition depending on the scenario. Following this concept, where only part of the information (partial concept) is used in the recognition, a novel method is presented in this work. This has been called Partial Principal Component Analysis (P²CA) since they fuse the Partial concept with the fundamentals of the well known PCA algorithm. This strategy has been proven to be very robust in pose variation scenarios showing that the 3D training process retains all the spatial information of the face while the 2D picture effectively recovers the face information from the available data. Furthermore, in this work, a novel approach for the automatic creation of 180° aligned cylindrical projected face images using nine different views is presented. These face images are created by using a cylindrical approximation for the real object surface. The alignment is done by applying first a global 2D affine transformation of the image, and afterward a local transformation of the desired face features using a triangle mesh. This local alignment allows a closer look to the feature properties and not the differences. Finally, these aligned face images are used for training a pose invariant face recognition approach (P²CA).     

CMOS-compatible optical rib waveguides defined by local oxidation of silicon

The local oxidation of silicon process is shown to be an effective means of defining optical rib waveguides in silicon on insulator while maintaining the surface planarity required for CMOS integration. Experimental waveguides have shown singlemode operation and losses of less than 1 dB/cm in the telecommunications band around 1550 nm     

松下演示三维等离子蓝光系统

10月初，在CEATEC上，松下公司展示了“世界上第一个三维全高清等离子影院系统”以及世界上最大的150英寸108019的等离子显示器。     

JVC亏损增加关闭电视工厂

JVC美国公司的母公司为日本Victor Co.,后者近日宣布,它将会关闭位于日本和苏格兰的电视机工厂,将制造部分转移到别的领域,以此提高公司利润率。和之前报道情况不一样的是,该公司称它将会削减电视机在日本的销售数量,而且不再销售消费市场的液晶电视机型,因为它     

An investigation of dark current and photocurrent superposition in photovoltaic devices

In the design and analysis of photovoltai cells, a principle of superposition of light and dark currents is usually assumed to apply. This principle states that the current flowing in an illuminated device subject to a bias V is given by the superposition of the short circuit photocurrent and the current that would flow at bias V in the dark. Using a straightforward modification of Shockley's theory of the pn junction diode, the validity of the superposition principle is established here for Si and GaAs homojunction cells exposed to one sun illumination. The argument commences by demonstrating that the quasi-fermi potentials are essentially constant across the depletion region for a device exposed to one sun illumination and biased at a reasonable operating point. Proceeding in this way, it is found that superposition applies even when recombination and photogeneration in the depletion region contribute substantially to both the dark current and the photocurrent. The theoretical argument is confirmed by direct numerical solution of the basic semiconductor equations.     

Optimum germanium profile for SiGe/int

The thermal stability of an SiGe base HBT is closely related to the integrated Ge content in the base. It is therefore appropriate to consider what form the Ge profile should take to minimise the base transit time tau /sub B/ for a given total Ge content. It is shown that a linear increase in Ge content from the base-emitter to the base-collector junction is required to minimise.<>     

Training 'greeble' experts: a framework for studying expert object recognition processes

Twelve participants were trained to be experts at identifying a set of 'Greebles', novel objects that, like faces, all share a common spatial configuration. Tests comparing expert with novice performance revealed: (1) a surprising mix of generalizability and specificity in expert object recognition processes; and (2) that expertise is a multi-faceted phenomenon, neither adequately described by a single term nor adequately assessed by a single task. Greeble recognition by a simple neural-network model is also evaluated, and the model is found to account surprisingly well for both generalization and individuation using a single set of processes and representations.