The challenges involved in concrete works of Marmaray immersed tunnel with service life beyond 100 years

Marmaray immersed tube crossing, located at the entrance of Bosphorus Strait of Istanbul, will be one of the unique infrastructure facility bringing great engineering challenges in immersed tunnel technology. The employer requires a minimum design life of 100 years for the immersed tunnel structure that will be under exposure of the highest saline water pressure at the depth of 58 m that has never been experienced yet in the history of immersed tube systems. Since the structural concrete is to be subjected to extremely aggressive environmental conditions during expected long-term service life, the quality assurance of the immersed tunnel has been ensured by setting a series of effective technical requirements taking into account the potential durability risks and predictive models in design phase, outputs of pre-testing activities and potential difficulties at construction period. The objective of this paper is to present some major steps involved in concrete works of this megaproject by giving the highlights from laboratory scale researches to the execution of the work at construction site.     

A methodological framework for defining ‘typological process’: the transformation of the residential environment in Ankara,Turkey

This paper investigates ‘typological process’, a key term in urban morphology due to its benefit to culturally-responsive urban design and place-making. The empirical identification of typological process is problematic because of researchers’ subjectivity in identifying changes, and the randomness of their selection of spatial characteristics in defining types. The paper demonstrates a method for defining and analyzing typological process in the transformation process of the residential environment in Ankara since the late nineteenth century. Three degrees of transformation are identified: continuity, partial continuity and mutation. The proposed method improves consistency and objectivity in the empirical validation of typological process.     

Enhancing ebXML Registries to Make them OWL Aware

ebXML is a standard from OASIS and UN/CEFACT which specifies an infrastructure to facilitate electronic business. In this paper, we address how ebXML registry semantics support can be further enhanced to make it OWL aware. OWL constructs are represented through ebXML registry information model constructs, and stored procedures are defined in the ebXML registry for processing the OWL semantics. These predefined stored queries provide the necessary means to exploit the enhanced semantics stored in the registry. In this way, an application program does not have to be aware of the details of how this semantics support is achieved in ebXML registry, and does not have to contain additional code to process this semantics.We believe that this approach is quite powerful to associate semantics with registry objects: it becomes possible to retrieve knowledge through queries, the enhancements to the registry are generic and also the registry specification is kept intact. The capabilities provided move the semantics support beyond what is currently available in ebXML registries and it does so by using a standard ontology language.To be able to demonstrate the benefits of the enhancements, we also show how the resulting semantics can be made use of in Web service discovery and composition.Recommended by: Athman Bouguettaya and Boualem BenatallahThis work is supported in part by the European Commission, Project No: IST-1-002104-STP SATINE and the Scientific and Technical Research Council of Turkey (TÜBÍTAK), Project No: EEEAG 104E013 and is realized as a proposal to OASIS ebXML Semantic Content Management subcommittee which is working on possible semantic extensions to the registry.     

Studies on the safety of glucose and paraben-containing neostigmine for intrathecal administration

Oxysterols are biologically active molecules generated during oxidation of LDL. Several of these oxysterols were found in macrophage-derived foam cells from human atherosclerotic tissue (eg, 7-hydroxycholesterol, 7-ketocholesterol, 5-epoxycholesterol, and 25-hydroxycholesterol). A specific stimulation of interleukin-8 (IL-8) production by oxidized LDL (oxLDL) has been shown by other investigators. In foam cells from human atherosclerotic tissue, we found high levels of IL-8 (183.1 pg/10(6) cells) compared with monocytes (23.2 pg/10(6) cells) or monocyte-derived macrophages in culture (1.5 pg/10(6) cells). When monocytes and monocyte-derived macrophages, in vitro, were exposed to a series of different oxysterols, we found that all oxysterols tested had a tendency to stimulate IL-8 production but that 25-hydroxycholesterol was the most potent one. This stimulation of IL-8 production was time and dose dependent and could be blocked by cycloheximide. These results indicate that oxysterols in oxLDL may have a regulatory effect on IL-8 production. IL-8, a potent chemoattractant, may play a role in the recruitment of T lymphocytes and smooth muscle cells into the subendothelial space and may contribute to the formation of atherosclerotic lesions.     

Identification of metabolic correlates of mild cognitive impairment in Parkinson's disease using magnetic resonance spectroscopic imaging and machine learning

Magnetic Resonance Materials in Physics, Biology and Medicine - To investigate metabolic changes of mild cognitive impairment in Parkinson’s disease (PD-MCI) using proton magnetic resonance...     

A Rate-1 Space-Time Diversity Method for Rotated 4-QAM Constellations

We propose a rate-1 space-time transmit diversity technique. We obtained second-order diversity by transmitting the real and imaginary parts of the symbols from two antennas. With four transmit antennas, we can add Alamouti coding to reach fourth-order transmit diversity. There is no need to detect symbols jointly in either of these applications. It is possible to use both Alamouti coding and Hadamard spreading diversity with the proposed method, thereby obtaining eighth-order (or even higher) transmit diversity. However, joint detection of the symbols is again required at this point. The proposed technique is a suitable space-frequency coding method for OFDM systems. We used computer simulations to compare our technique with the Alamouti coding, quasi-orthogonal space-time block coding (QOSTBC), and orthogonal space–time block coding (OSTBC) methods. We also compared its performance to that of Hadamard spreading diversity. Alamouti coding performs better than the proposed technique at the second order of transmit diversity, but is also limited to that order. The proposed technique performs better than OSTBC at the same order of the transmit diversity. QOSTBC performs slightly better than the proposed technique at the same order of transmit diversity. However, when all methods have the same detection complexity, the proposed technique performs better than both QOSTBC and Hadamard spreading diversity.     

Plant-wide hierarchical optimization and control of an industrial hydrocracking process

Hydrocracking is a crucial refinery process in which heavy hydrocarbons are converted to more valuable, low-molecular weight products. Hydrocracking plants operate with large throughputs and varying feedstocks. In addition the product specifications change due to varying economic and market conditions. In such a dynamic operating environment, the potential gains of real-time optimization (RTO) and control are quite high. At the same time, real-time optimization of hydrocracking plants is a challenging task. A complex network of reactions, which are difficult to characterize, takes place in the hydrocracker. The reactor effluent affects the operation of the fractionator downstream and the properties of the final products. In this paper, a lumped first-principles reactor model and an empirical fractionation model are used to predict the product distribution and properties on-line. Both models have been built and validated using industrial data. A cascaded model predictive control (MPC) structure is developed in order to operate both the reactor and fractionation column at maximum profit. In this cascade structure, reactor and fractionation units are controlled by local decentralized MPC controllers whose set-points are manipulated by a supervisory MPC controller. The coordinating action of the supervisory MPC controller accomplishes the transition between different optimum operating conditions and helps to reject disturbances without violating any constraints. Simulations illustrate the applicability of the proposed method on the industrial process.