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71.
Public Private Partnerships (PPPs) are increasingly heralded as an innovative policy intervention in the context of critical urban infrastructure services where outright privatization and loss of control are considered unacceptable. This paper assesses a proposed PPP for the management of water services in the Lebanese capital, Beirut. Although the city of Beirut and its suburbs are considered as the center of social, economic, and political activities in the country, safe drinking water is not accessible to all the population of the city in view of the current economic crisis and the high level of urbanisation. A PPP is viewed as a promising solution to the water supply problem, especially in poor and suburban areas. After introducing PPPs and the rationale behind invoking private sector participation, this paper assesses the potential promise of different forms of PPPs in the context of the economic and institutional framework of water management in the Greater Beirut Area (GBA).  相似文献   
72.
True-time-delay devices could significantly contribute to improving the performance of many optical systems in applications such as sensing, ranging, communication and signal processing. Delay devices based on spiral optical waveguides are of special interest due to their small size and relatively low power attenuation. In this paper, we propose to fabricate spirals on both sides of a wafer, where the coupling between them is through a vertical interconnect. The novel through-wafer interconnect has a level of attenuation that compares competitively with that obtained with a conventional s-shaped interconnect between two interleaved spirals and considerably simplifies the waveguide design and fabrication.  相似文献   
73.
Since the aroma is one of the essential factors for evaluating fruit quality, a headspace–solid-phase microextraction and gas chromatography–mass spectrometry method for the identification and quantification of the aroma volatile constituents in melon fruits has been developed. Two different varieties of Cucumis melo L., reticulatus and inodorus, have been analyzed and 66 volatile compounds have been identified and quantified; among these, the impact aroma compounds are included too. The volatile compounds have been identified by linear retention index, mass spectra, standard injection, and reference data; the quantification has been carried out by the standard addition technique. The method proposed showed good linearity within the concentration range tested; the precision, CV was <15% for all the components identified, and the limits of quantification was very low for most of the components, for example, 1.7 ng/g for ethyl octanoate and 1.5 ng/g for limonene. The results emphasized each fruit variety could be distinguished by a different qualitative and quantitative volatile fraction composition; as example, reticulatus samples were characterized by a high amount of esters (192.8 μg/Kg), which were present as traces in inodorus. Sensory analysis was performed on the samples and quantitative volatile and sensory data were correlated using multivariate analysis. The developed method allowed us to obtain reliable quantitative data of the melon volatile constituents which are necessary for the fruit quality evaluation since the aroma contribution of a particular substance is assessed by knowledge of the ratio between its amount and odor threshold level.  相似文献   
74.
Functional poly(acrylonitrile-co-acrylic acid) imprinted pearls, selective for diosgenin – a steroidal saponin with the ability to reduce cholesterol from blood – were prepared by wet phase inversion. Three copolymers with the monomer ratios AN:AA90:10, 80:20, and 70:30 where used to prepare the corresponding MIPs (molecularly imprinted polymers) and NIPs (non-imprinted polymers).The rheology studies showed that an 8 w% solution of copolymer in dimethylformamide lead fastest to robust, spherical pearls. Affinity centres were generated via non-covalent bonding between diosgenin’s hydroxyl groups and carboxyl moieties of the copolymer matrix. The presence and the quality of the selective binding sites in MIPs were highlighted by optic and electronic microscopy, infrared spectroscopy, thermal analyses, and batch rebinding tests. The imprinting factor (IF) values, ranging from 1.9 to 4.35, decrease with the increasing of the initial concentration of feed solution. When comparing the MIPs concerning the AN:AA ratio, the IF decreases in the order AN:AA80:20 > AN:AA70:30 > AN:AA90:10, suggesting that the 80:20 ratio is the optimum compromise between selectivity (given by AA) and resistance (given by AN). For the best imprinted MIP, 80:20, affinity tests were performed with three competitors, obtaining the average affinity 54%, compared with 31%, 11%, and 4% for the competitors.  相似文献   
75.
The cutting processes with tools that generate “through-winding straight-involute teeth-gears”, tools associated with couples of centrodes-in-rolling (such as the rack-tool), are characterized by a fairly complicated cutting scheme, due to the specific shape of the tools and, at the same time, due to the rolling process of the axodes associated with the tool and the blank. The present solutions are not accorded well enough to the process and lead to significant variations in the detached chip area value regarding the machined wheel teeth number. It is accepted that the main cutting force size depends on the size of the area of the cutting layer (the geometrical area of the once detached chip by the assembly of operative edges of this kind of tools). The geometrical modeling of the generation process proves this and it could be considered a criterion for the reconfiguration of the cutting tool. In this work, there is defined a criterion so as to describe the cutting scheme, and based on this criterion we can compare the variation laws for the chip area size when generating the modeling of the cylindrical straight teethed gears. We propose a modeling of the cutting schemes in order to get new constructive forms of the cutting tools that will lead to cutting schemes adaptable to the number of teeth of the processed gear with the purpose of diminishing the teething cutting force. Also, there is presented a constructive solution for a rack-tool with reconfigurable structure with the purpose of according the teething process with the processed gear number of teeth.  相似文献   
76.
The authors examined how visual selection mechanisms may relate to developing cognitive functions in infancy. Twenty-two 3-month-old infants were tested in 2 tasks on the same day: perceptual completion and visual search. In the perceptual completion task, infants were habituated to a partly occluded moving rod and subsequently presented with unoccluded broken and complete rod test stimuli. In the visual search task, infants viewed displays in which single targets of varying levels of salience were cast among homogeneous static vertical distractors. Infants whose posthabituation preference indicated unity perception in the completion task provided evidence of a functional visual selective attention mechanism in the search task. The authors discuss the implications of the efficiency of attentional mechanisms for information processing and learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
77.
Tetrachlorobisphenol A and bis(2,3 dichloropropyl)phosphorochloridite form a polycondensate with the elimination of HCl and 2,3 dichloropropanol. The polyphosphite formed undergoes an Arbuzov transposition leading to a more stable polyphosphonate. I.r. and 1H-n.m.r. spectroscopy give support for the described mechanism. From the 1H-n.m.r. spectral integrals which were registered during the reaction, the separate processes and the rate of consumption of tetrachlorobisphenol A, may be quantitatively determined. The reaction temperature has to be kept below 200°C in order to avoid side reactions.  相似文献   
78.
NIST tools address problems posed by testing 3D graphics. The article explains the test development strategy and design issues in developing and delivering these testing tools. In 1996, NIST staff met with interested members of the VRML community to discuss various approaches to testing the Virtual Reality Modeling Language (VRML) specification. The standard defines requirements for creating VRML worlds, tools that generate VRML worlds (authoring tools), and tools that interpret and properly render VRML worlds (browsers). It was agreed that VRML worlds, whether generated by hand or through an authoring tool, must be fully compliant with the standard. Furthermore, they must be viewable and reasonably similar in a variety of VRML browsers, regardless of the underlying hardware and software platforms. Consequently, NIST developed metrology tools to support testing VRML content, authoring tools, and browsers. VRML content and the associated authoring tools are tested using a locally developed reference parser, Viper. VRML browsers are tested using a test suite of conformant files, called the VRML Test Suite (VTS). The VTS tests the VRML built-in nodes, VRML extensible components, and base execution model. Finally, the true dynamic nature of VRML is tested using automatic test generation techniques built through extension of the Viper source code. We also address using the Web as a vehicle for delivering these metrology tools  相似文献   
79.
Gastric cancer has remained in the top five cancers for over ten years, both in terms of incidence and mortality due to the shortage of biomarkers for disease follow-up and effective therapies. Aiming to fill this gap, we performed a bioinformatics assessment on our data and two additional GEO microarray profiles, followed by a deep analysis of the 40 differentially expressed genes identified. PPI network analysis and MCODE plug-in pointed out nine upregulated hub genes coding for proteins from the collagen family (COL12A1, COL5A2, and COL10A1) or involved in the assembly (BGN) or degradation of collagens (CTHRC1), and also associated with cell adhesion (THBS2 and SPP1) and extracellular matrix degradation (FAP, SULF1). Those genes were highly upregulated at the mRNA and protein level, the increase being correlated with pathological T stages. The high expression of BGN (p = 8 × 10−12), THBS2 (p = 1.2 × 10−6), CTHRC1 (p = 1.1 × 10−4), SULF1 (p = 3.8 × 10−4), COL5A1 (p = 1.3 × 10−4), COL10A1 (p = 5.7 × 10−4), COL12A1 (p = 2 × 10−3) correlated with poor overall survival and an immune infiltrate based especially on immunosuppressive M2 macrophages (p-value range 4.82 × 10−7–1.63 × 10−13). Our results emphasize that these genes could be candidate biomarkers for GC progression and prognosis and new therapeutic targets.  相似文献   
80.
Obstructive sleep apnea (OSA) is characterized by repetitive upper airway collapse, chronic hypoxia and a proinflammatory phenotype. The purpose of our study was to evaluate readily available inflammatory biomarkers (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell count (WBC), red cell distribution width (RDW), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), WBC-to-MPV ratio (WMR) and lymphocyte-to-C-reactive protein ratio (LCR)) before and after CPAP in patients with moderate–severe OSA. We performed a prospective study that included patients with newly-diagnosed moderate–severe OSA. The control groups (patients without OSA and with mild OSA) were selected from the hospital polygraphy database. All subjects underwent routine blood panel, which was repeated in moderate–severe OSA patients after 8 weeks of CPAP. Our final study group included 31 controls, 33 patients with mild, 22 patients with moderate and 37 patients with severe OSA. CRP, ESR, NLR and WMR were correlated with OSA severity. After 8-week CPAP therapy, we documented a decrease in weight status, which remained statistically significant in both CPAP-adherent and non-adherent subgroups. Readily available, inexpensive inflammatory parameters can predict the presence of moderate–severe OSA, but are not influenced by short-term CPAP.  相似文献   
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