A review of installed solar photovoltaic and thermal collector capacities in relation to solar potential for the EU-15

This article analyses the energy statistics of 15 European Union countries (EU-15), giving special emphasis to the installed solar photovoltaic and thermal collector capacity. The installed capacities per capita are analysed in relation to the solar radiation income of respective countries with the view to explore the relationship between the solar income and its utilisation as of the year 2006. In terms of the installed solar thermal collector capacity, Austria leads the statistics amongst the countries studied with 223W_th collector capacity per capita, followed by Greece with 207W_th. Except for Greece, it is observed that the countries with high solar radiation income are lacking to realise their solar potential. Regarding the installed photovoltaic power per capita, Luxembourg leads the pack by a wide margin with 47W_p capacity, followed by Germany with 30W_p. Fiscal instruments to invigorate the deployment of solar energy have also been identified in this work.     

Structural changes driven by e-petitioning technology: changing the relationship between the central government and local governments

ABSTRACT

e-Petitioning is a type of information and communication technology for development that can be used by citizens to express their voices in society. Although much work is focused on government-citizen relationships, little is known about whether and, if so, how e-petitions technology might result in structural transformations in public administration. In this study, we investigated the effects of an e-petitioning system in the Turkish public administration from neo-institutional and transaction cost perspectives. In contrast to the expectation of reducing transaction costs due to ICTs use, the transaction costs increased. The changes have further strengthened the central government by transforming the current tutelary relationship into a more hierarchical structure. The change is not driven by lowering transaction costs; instead, the change mirrors the power structures. The use of technology changed the structures in such a way that political power structures are reinforced while empowering the citizens to make their voices heard.     

Mechanical properties of P/M 316L stainless steel materials

In this work, 316L stainless steel (SS) powder was used. The composition of the powder is as follows: 0.015% C, 1.75% Mn, 0.45% Si, 17.24% Cr, 2.79% Mo, 14.65% Ni, and balance iron. Mixed powder was compressed cold using single action press under 800 MPa pressure. Compressed samples were sintered at 1200 °C, 1250 °C, and 1300 °C into the nitrogen gas atmosphere. In order to determine the mechanical properties of the produced specimens, the fatigue tests, tensile test, three-point bending test, impact test and hardness tests were applied to the specimens. Determined mechanical properties in the result of this work were compared to the properties as stated in ASTM F138-G2. Besides that to define the microstructures of the produced specimens in detail, metallographic studies were performed.     

Multilabel associative classification categorization of MEDLINE articles into MeSH keywords.

The specific characteristic of classification of medical documents from the MEDLINE database is that each document is assigned to more than one category, which requires a system for multilabel classification. Another major challenge was to develop a scalable method capable of dealing with hundreds of thousand of documents. We proposed a novel system for automated classification of MEDLINE documents to MeSH keywords based on the recently developed data mining algorithm called ACRI, which was modified to accommodate multilabel classification. Five different classification configurations in conjunction with different methods of measuring classification quality were proposed and tested. The extensive experimental comparison showed superiority of methods based on reoccurrence of words in an article over nonrecurrent-based associative classification. The achieved relatively high value of macro F1 (46%) demonstrates the high quality of the proposed system for this challenging dataset. Accuracy of the proposed classifier, defined as the ratio of the sum of TP and TN examples to the total number of examples, reached 90%. Three scenarios were proposed based on the performed tests and different possible objectives. If a goal is to classify the largest number of documents, a configuration that maximizes micro F1 should be chosen. On the other hand, if a system is to work well for categories with a small number of documents, a configuration that maximizes macro F1 is more suitable. A tradeoff can be obtained by using a configuration that optimizes the average between macro and micro F1.     

Emerging tools,enabling technologies,and future opportunities for the bioproduction of aromatic chemicals

Aromatic compounds, which are traditionally derived from petroleum feedstocks, represent a diverse class of molecules with a wide range of industrial and commercial applications. Significant progress has been made to alternatively and sustainably produce many aromatics from renewable substrates using microbial biocatalysts. While the construction of both natural and non-natural pathways has expanded the number and diversity of aromatic bioproducts, pathway modularization in both single- and multi-strain systems continues to support the enhancement of key production metrics towards economically-viable levels. Emerging tools for implementing more precise metabolic control (e.g. CRISPRi, sRNA) as well as the engineering of novel high-throughput screening platforms utilizing in vivo aromatic biosensors, meanwhile, continue to facilitate further optimization of both pathways and hosts. While product toxicity persists as a key challenge limiting the production of many aromatics, various successful strategies have been demonstrated towards improving tolerance, including via membrane and efflux pump engineering as well as by exploiting alternative production hosts. Finally, as a further step towards sustainable and economical aromatic bioproduction, non-model substrates including lignin-derived compounds continue to emerge as viable feedstocks. This review highlights recent and notable achievements related to such efforts while offering future outlooks towards engineering microbial cell factories for aromatic production. © 2018 Society of Chemical Industry     

Experimental investigation and numerical modelling of photocurrent oscillations in lattice matched Ga1?x In x N y As1?y /GaAs quantum well p-i-n photodiodes

Photocurrent oscillations, observed at low temperatures in lattice-matched Ga_1−xIn_xN_yAs_1−y/GaAs multiple quantum well (MQW) p-i-n samples, are investigated as a function of applied bias and excitation wavelength and are modelled with the aid of semiconductor simulation software. The oscillations appear only at low temperatures and have the highest amplitude when the optical excitation energy is in resonance with the GaInNAs bandgap. They are explained in terms of electron accumulation and the formation of high-field domains in the GaInNAs QWs as a result of the disparity between the photoexcited electron and hole escape rates from the QWs. The application of the external bias results in the motion of the high-field domain towards the anode where the excess charge dissipates from the well adjacent to anode via tunnelling.     

Fast surrogate-assisted simulation-driven optimization of compact microwave hybrid couplers

This work presents a robust methodology for expedited simulation-driven design optimization of compact microwave hybrid couplers. The technique relies on problem decomposition, and a bottom–up design strategy, starting from the level of basic building blocks of the coupler, and finishing with a tuning procedure that exploits a fast surrogate model of the entire structure. The latter is constructed by cascading local response surface approximations of coupler elementary elements. The cross-coupling effects within the structure are neglected in the first stage of the design process; however, they are accounted for in the tuning phase by means of space-mapping correction of the surrogate. The proposed approach is demonstrated through the design of a compact rat-race and two branch-line couplers. In all cases, the computational cost of the optimization process is very low and corresponds to just a few high-fidelity electromagnetic simulations of respective structures. Experimental validation is also provided.     

Thermal optical properties of TiO2 films

A fibre optic experimental arrangement was used to determine the thermo-optic coefficient (dn/dT) of electron beam deposited titanium dioxide coatings on the cleaved end faces of multimode optical fibres for a wavelength range between 600 and 1050 nm. The temperature-induced change in the index of refraction (n) and extinction coefficient (k) were successfully determined from reflection spectra. Measurements of n and k at various wavelengths for different temperatures enabled the determination of dn/dT and dk/dT. It was found that dn/dT takes different values at different temperature ranges. For example, at 800 nm, dn/dT was (−1.77±0.7)×10⁻⁴ K⁻¹, between 18°C and 120°C, and took a value of (−3.04±0.7)×10⁻⁴ K⁻¹ between 220°C and 325°C.     

Evaluation the effects of edge banding type and thickness on the strength of corner joints in case-type furniture

Edge banding is used to cover the exposed sides of wood materials such as plywood, particleboard or medium-density fiberboard, giving the appearance of a solid (or more valuable) material. This study was carried out to determine the effects of the edge banding material, namely polyvinyl chloride (PVC), melamine and wood veneer, thickness of edge banding material (0.4, 1, and 2 mm), and wood composite panel type on the diagonal compression and tension strength properties of particleboard surfaced with synthetic resin sheet (LamPb) and MDF surfaced with synthetic resin sheet (LamMDF).