Cubic Phase GaN on Nano‐grooved Si (100) via Maskless Selective Area Epitaxy

A method of forming cubic phase (zinc blende) GaN (referred as c‐GaN) on a CMOS‐compatible on‐axis Si (100) substrate is reported. Conventional GaN materials are hexagonal phase (wurtzite) (referred as h‐GaN) and possess very high polarization fields (～MV/cm) along the common growth direction of <0001>. Such large polarization fields lead to undesired shifts (e.g., wavelength and current) in the performance of photonic and vertical transport electronic devices. The cubic phase of GaN materials is polarization‐free along the common growth direction of <001>, however, this phase is thermodynamically unstable, requiring low‐temperature deposition conditions and unconventional substrates (e.g., GaAs). Here, novel nano‐groove patterning and maskless selective area epitaxy processes are employed to integrate thermodynamically stable, stress‐free, and low‐defectivity c‐GaN on CMOS‐compatible on‐axis Si. These results suggest that epitaxial growth conditions and nano‐groove pattern parameters are critical to obtain such high quality c‐GaN. InGaN/GaN multi‐quantum‐well structures grown on c‐GaN/Si (100) show strong room temperature luminescence in the visible spectrum, promising visible emitter applications for this technology.     

OpenIPTV: a comprehensive SDN-based IPTV service framework

IPTV is an emerging TV content delivery service that should guarantee Quality of Service (QoS) to deliver television contents over IP for their customers. However, providing such QoS regarding service level agreements (SLA) requires frequent service monitoring and adaptive configuration mechanisms. Nowadays, Software Defined Networks (SDNs) provide capabilities to deploy and manage networks dynamically and can maintain QoS. In this paper, a novel IPTV service framework (OpenIPTV) is proposed, which utilizes SDN as an underlying technology for providing QoS for IPTV customers in a shared backbone network. OpenIPTV is implemented in a well-known OpenDayLight controller and strictly followed a modular design for the sake of efficiency. OpenIPTV comprises all service requirements such as resource monitoring, channel changing, multicast group managing and dynamic QoS multicast traffic engineering. The performance of OpenIPTV is evaluated under different scenarios and experimental results confirmed the effectiveness of the proposed framework in terms of QoS metrics. Furthermore, experimental results show that OpenIPTV is a feasible and practical solution to deliver IPTV services with high level of QoS over SDN.     

A microwave-assisted new synthesis of sulfonylidene–sulfonamide via reactions of N-sulfonylketenimine and sodium arylsulfinates

A rapid practical microwave-assisted new synthesis of sulfonylidene–sulfonamide was developed via the one-pot, three-component reaction of sulfonyl azides, terminal alkynes, and sodium arylsulfinates catalyzed by copper(I) iodide in DMF in moderate to good yields.     

Preventing failure in IT-enabled systems for supply chain management

Supply chain management (SCM) emphasises the overall and long-term benefit of all parties on the chain through cooperation and information sharing. This signifies the importance of communication and the application of IT-enabled systems in SCM. A supply chain management information system (SCMIS) is usually user-interfaced and designed to provide information and information processing capability to support the strategy, operations, management analysis, and decision-making functions in an organisation's supply network. SCMIS provides high quality, relevant and timely information flow that effectively supports decision-making for inventory replenishment, capacity activation, and for synchronising material flows at all tiers within the supply chain. In recent years, there have been some efforts on designing efficient information systems for supply chain management; but many of them have led to failure. Using a critical failure factor (CFF) approach and based on a perfect study, we investigate this crucial issue in-depth and put forward feasible solutions regarding failure prevention in such systems throughout this article. Three main purposes of this paper are to: (1) identify SCMIS and its characteristics, (2) introduce and categorise the critical failure factors of SCM and SCMIS, and (3) investigate the explanatory power of these CFFs on the performance of supply channel processes performed through SCMIS.     

Extraction of dyes from Delphinium Zalil flowers and dyeing silk yarns

Delphinium Zalil from the family Ranunculaceae grows naturally in mountainous area of northeast of Iran. It has beautiful yellow flowers which contain flavonoids. In this study, the flowers of D. Zalil were collected, dried, powdered, and extracted with different solvent systems. Quercetin is identified as the main aglycone responsible for the color in these flowers. The flowers were then used for dyeing silk yarns. The color strength values were used to optimize the dyeing process. Pre-mordanting was proved to increase the dye absorption which may lead to an optimum usage of mordant. This would certainly be of special interest to environmentalists. Dyed silk yarns presented good light fastness compared to Blue Scale.     

窄禁带半导体光电二极管的最新进展（下）

隧道电流和R0A乘积主要取决于掺杂浓度.图5表示77 K温度工作、一面突变的HgCdTe、PbSnTe、PbSnSe光电二极管(Eg=0.1 eV)的R0A乘积与掺杂浓度的关系.对于HgCdTe和铅盐探测器来说,要想产生高数值的RoA乘积,就分别需要1016 cm-3和1017 cm-3(或略少些)的掺杂浓度.由于要避免产生隧道效应而所能获得的最大掺杂浓度是Ⅳ族光电二极管比HgCdTe光电二极管要高一个数量级[11].这是由于前者的介电常数εs很高,因为隧道效应对RoA乘积的贡献包含着exp[常数m*εs/N)1/2Egl因子,亦即呈现指数增加的关系.     

Survivability Performance Evaluation of WDM Networks with Wavelength Converters

Network Survivability is defined as the ability of a network to support the committed Quality of Services (QoS) continuously in the presence of different failure scenarios. Both availability and performance degradation of a system in presence of failure are integral components of survivability evaluation. Therefore, a composite model is presented for network survivability that includes system availability analysis to find out the cost due to system downtime, and system failure impact analysis to find out the transient performance degradation when failure occurs. A new analytical technique is presented to evaluate the excess loss due to failure (ELF) as the transient performance degradation when the system is operating in gracefully degraded states. Single and multiple link failures as well as node failures are considered. An algorithm is proposed to carry out the steady state availability analysis of a network even when the available paths between a pair of nodes are non-disjoint. A recursive generalized form of the availability algorithm when there are multiple paths available between a pair of nodes is presented. The availability model and the performance model are combined to construct a hierarchical model to evaluate the network survivability performance. Simulation results are used to validate the proposed model. A WDM network with wavelength conversion is considered as an example for this evaluation.     

A legal licence for an ecological disaster: the inadequacies of the 1973 Helmand/Hirmand water treaty for sustainable transboundary water resources development

This article questions whether the 1973 Helmand/Hirmand water treaty between Afghanistan and Iran is an appropriate institutional tool for sustainable water resources management in the context of transboundary water resources development. It shows that by failing to fulfil the most basic requisites for integrated water resources management and river basin management, the treaty does not ensure the integrity of the downstream agro-ecological system in the Sistan Delta. As a result, the 1973 treaty may not be the most relevant water regime for helping to balance legitimate development in upstream Afghanistan while also limiting harms to downstream Iran.     

BiTE: a dynamic bi-level traffic engineering model for load balancing and energy efficiency in data center networks

Applied Intelligence - With the recent significant growth of virtualization and cloud services, the data center network (DCN) as the underlying infrastructure is more important. The increasing and...