Highly directional emission and photon beaming from nanocrystal quantum dots embedded in metallic nanoslit arrays

We demonstrate a directional beaming of photons emitted from nanocrystal quantum dots that are embedded in a subwavelength metallic nanoslit array with a divergence angle of less than 4°. We show that the eigenmodes of the structure result in localized electromagnetic field enhancements at the Bragg cavity resonances, which could be controlled and engineered in both real and momentum space. The photon beaming is achieved using the enhanced resonant coupling of the quantum dots to these Bragg cavity modes, which dominates the emission properties of the quantum dots. We show that the emission probability of a quantum dot into the narrow angular mode is 20 times larger than the emission probability to all other modes. Engineering nanocrystal quantum dots with subwavelength metallic nanostructures is a promising way for a range of new types of active optical devices, where spatial control of the optical properties of nanoemitters is essential, on both the single and many photons level.     

Cellular pathology and histopathology of hypo-salinity exposure on the coral Stylophora pistillata

Coral reefs can experience extreme salinity changes, particularly hypo-salinity, as a result of storms, heavy rainy seasons (e.g., monsoons), and coastal runoff. Field and laboratory observations have documented that corals exposed to hypo-saline conditions can undergo extensive bleaching and mortality. There is controversy in the literature as to whether hypo-saline conditions induce a pathological response in corals, and if there is a relationship between decreasing salinity treatment and pathological responses. To test the hypothesis that hypo-salinity exposure does not have a pathological effect on coral, we used histological and cellular diagnostic methods to characterize the pathology in hypo-salinity-exposed corals. Colonies of Stylophora pistillata were exposed to five salinity concentrations [39 parts per thousand (ppt), 32 ppt, 28 ppt, 24 ppt, and 20 ppt] that may realistically occur on a reef. Histological examination indicated an increasing severity of pathomorphologies associated with decreasing salinity, including increased tissue swelling, degradation and loss of zooxanthellae, and tissue necrosis. Pulse-amplitude modulated chlorophyll fluorimetry kinetics demonstrated a decreasing photosynthetic efficiency with decreasing salinity conditions. Cytochrome P450 levels were affected by even slight changes in salinity concentration suggesting that detoxification pathways, as well as several endocrine pathways, may be adversely affected. Finally, these studies demonstrated that hypo-saline conditions can induce an oxidative-stress response in both the host and in its algal symbiont, and in so doing, may synergistically increase oxidative-stress burdens. As with other types of environmental stresses, exposure to hypo-saline conditions may have long-term consequences on coral physiology.     

An improved algorithm for online coloring of intervals with bandwidth

We present an improved online algorithm for coloring interval graphs with bandwidth. This problem has recently been studied by Adamy and Erlebach and a 195-competitive online strategy has been presented. We improve this by presenting a 10-competitive strategy. To achieve this result, we use variants of an optimal online coloring algorithm due to Kierstead and Trotter.     

Membrane technology for advanced wastewater reclamation for sustainable agriculture production

Treated domestic secondary effluent is a valuable water source that can be reused for diverse purposes. However, in order to minimize health and environmental risks and to maintain adequate levels of sustainable agriculture production on a long range time scale, advanced treatment is required. Advanced effluent quality maintaining minimal risks can be primarily attained by implementing the membrane technology. Field experiments are in progress for secondary wastewater polishing for unrestricted reuse for sustainable agricultural production. The two stage membrane treatment system for the secondary effluent polishing consists of combining two main stages: ultrafiltration (UF) and reverse osmosis (RO) membrane treatment. The UF stage is efficient in the removal of the organic matter and the pathogens while the RO provides the dissolved solids (salinity) removal. Effluent of various qualities is applied for irrigation along with continuous monitoring of the membrane components performance. The experimental data was obtained in the ongoing pilot studies carried out near the City of Arad (Israel) wastewater treatment system (the pilot plant performs in a feed and bleed operation mode). The results indicate the importance of maintaining high quality effluent for sustainable agriculture production. The management modeling gives an idea of the importance in maintaining adequate UF flushing policy in order to minimize expenses due to fouling.     

热的LDI: 满足HDI印刷术的挑战

关于PCB制造商能力的高密度互连技术的定位领域问题。为了达到目前和未来封装技术所需的互连密度的要求,印制电路板工业将持续地移向更小的图形尺寸。当图形尺寸减小和信号传输速度增加时,对于低缺陷密度和高质量的制造工艺之要求将强烈地增加了。这样一来,HDI电路的制造,也就是导线和连接盘的图形生产在制造加工过程中将变成一个重要的舞台。     

Context-based Space Filling Curves

A context-based scanning technique for images is presented. An image is scanned along a context-based space filling curve that is computed so as to exploit inherent coherence in the image. The resulting one-dimensional representation of the image has improved autocorrelation compared with universal scans such as the Peano-Hilbert space filling curve. An efficient algorithm for computing context-based space filling curves is presented. We also discuss the potential of improved autocorrelation of context-based space filling curves for image and video lossless compression.     

The Earth Mover's Distance as a Metric for Image Retrieval

We investigate the properties of a metric between two distributions, the Earth Mover's Distance (EMD), for content-based image retrieval. The EMD is based on the minimal cost that must be paid to transform one distribution into the other, in a precise sense, and was first proposed for certain vision problems by Peleg, Werman, and Rom. For image retrieval, we combine this idea with a representation scheme for distributions that is based on vector quantization. This combination leads to an image comparison framework that often accounts for perceptual similarity better than other previously proposed methods. The EMD is based on a solution to the transportation problem from linear optimization, for which efficient algorithms are available, and also allows naturally for partial matching. It is more robust than histogram matching techniques, in that it can operate on variable-length representations of the distributions that avoid quantization and other binning problems typical of histograms. When used to compare distributions with the same overall mass, the EMD is a true metric. In this paper we focus on applications to color and texture, and we compare the retrieval performance of the EMD with that of other distances.     

A multinomial model for the machine interference problem with different service types and multiple operators

This paper proposes a model for a special case of the machine interference problem (MIP), where each of N identical machines randomly requests several different service types. Each request for a service type is fulfilled by an operator who can provide only one service type. The model allows the calculation of the expected interference (waiting) time in the queue for each service type, according to the multinomial distribution. The uniqueness of the model is that under its assumptions internal service order and queue discipline are not needed for the interference calculations. The model requires as inputs only the machine runtime and the average time of each service type that is needed to produce one unit. These inputs can be obtained by a common work measurement. The model enables practitioners to determine the optimal numbers of operators that are needed for each service type in order to minimize the cost per unit or maximize the profit, or to set other performance measures. To demonstrate the applicability of the model, a theoretical analysis and a case study are presented.