64 research outputs found

    The initiation and development of combustion under cold idling conditions using a glow plug in diesel engines

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    Factors determining the success or failure of combustion initiation using a glow plug have been investigated through experimental work on a single cylinder, common rail diesel engine with a geometric compression ratio of 15.5, and a quiescent combustion bomb with optical access. A glow plug was required to avoid engine misfires when bulk gas temperature at the start of injection was less than 413 C. The distance between the glow plug and the spray edge, the glow plug temperature, and the bulk gas temperature were important factors in meeting two requirements for successful ignition: a minimum local temperature of 413 C and a minimum air/fuel vapour equivalence ratio of 0.15–0.35

    Renal clearable catalytic gold nanoclusters for in vivo disease monitoring

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    Ultra-small gold nanoclusters (AuNCs) have emerged as agile probes for in vivo imaging, as they exhibit exceptional tumour accumulation and efficient renal clearance properties. However, their intrinsic catalytic activity, which can enable increased detection sensitivity, has yet to be explored for in vivo sensing. By exploiting the peroxidase-mimicking activity of AuNCs and the precise nanometer size filtration of the kidney, we designed multifunctional protease nanosensors that respond to disease microenvironments to produce a direct colorimetric urinary readout of disease state in less than 1 h. We monitored the catalytic activity of AuNCs in collected urine of a mouse model of colorectal cancer where tumour-bearing mice showed a 13-fold increase in colorimetric signal compared to healthy mice. Nanosensors were eliminated completely through hepatic and renal excretion within 4 weeks after injection with no evidence of toxicity. We envision that this modular approach will enable rapid detection of a diverse range of diseases by exploiting their specific enzymatic signatures

    A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation

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    Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies

    A multilaboratory comparison of calibration accuracy and the performance of external references in analytical ultracentrifugation.

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    Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies

    A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation

    Get PDF
    Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies

    Near IR Absorbing Bodipy-functionalized SPIONs: A Potential Magnetic Nanoplatform for Diagnosis and Therapy

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    Cataloged from PDF version of article.Photodynamic therapy (PDT), especially with the recent advances in photosensitizer (PS) design, has already been established as a noninvasive technique for cancer treatment. Recently, near-IR-based absorbing PSs that have a rising potency to implement light-triggered tumor ablation have attracted much attention since near-IR light in the 650-850 nm range penetrates more deeply in tissues. Up to now, numerous nanomaterials tailored to suitable sizes have been studied for effective delivery of PSs. In this study, four different types of Bodipy-based PSs were covalently attached to magnetic resonance imaging (MRI) active, biocompatible, and nontoxic nanocarriers and generation of singlet oxygen capabilities were evaluated. It was demonstrated that these core-shell nanoparticles are promising delivery vehicles of PSs for use in diagnosis and therapy

    ENOTOURISM AS AN INSTRUMENT FOR PROMOTING RURAL DEVELOPMENT IN THRACE REGION (TURKEY)

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    Anatolia, which has hosted many civilisations for centuries, has great tourism potential with its natural and cultural resource values. Not only as a general destination for tourism but also as an alternative tourism destination, Anatolia is attracting the attention of local and foreign tourists. In recent years enotourism has been developing in Turkey and by popularising new destinations, it has become an important sector for tourism. Turkey is located in the Earth most conducive climate zone for viticulture. The history of viticulture in whole Anatolia goes back to 3500 years B.C. Turkey consists of seven regions which have different geographic and climatic characteristics. In almost every region, various grape species are cultivated and wine production is made. In Turkey, 49% of the land are used for agricultural purposes and 1.2% of agricultural land are used for grape cultivation. According to FAO 2012 database, Turkey is ranked 6th out of all world countries in the grape production but only 2% of grapes are used for wine production. With implementation of wrong policies, prohibitions and obstructions for wine production and consumption, the benefits of enotourism to Anatolia can not be adequately assessed. Within the context of this study, economic contribution of enotourism, the changes in the employment opportunities of local communities and changes in the tourism movements are examined in the Thrace region where 40% of Turkey wine production is carried out

    Robust multivariable feedback control of natural gas-diesel RCCI combustion

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    Advanced combustion concepts such as Reactivity Controlled Compression Ignition (RCCI) demonstrate very high thermal efficiencies combined with ultra low NOx emissions. As RCCI is sensitive for operating conditions, closed-loop control is a crucial enabler for stable and robust combustion. The feedback design is complex due to the coupling between inputs, such as intake manifold temperature, blend ratio (BR), and air-to-fuel ratio (λ), and, on the other hand, combustion parameters. Contrary to earlier, parallel SISO approaches, a multivariable feedback control strategy is applied, which uses a new combination of control parameters. Following the linearisation of a validated multi-zone RCCI combustion model, a MIMO feedback control strategy is designed. This cycle-to-cycle control strategy uses diesel injection timing, diesel fuel quantity, and natural gas (NG) fuel quantity information to track the desired engine load, ignition delay, and a new control parameter: BR. The designed controller is validated with simulation cases for disturbance rejection and simultaneous multivariable reference tracking. Simulation results demonstrate robust performance, effective decoupling action, and fast settling time (within 3 engine cycles) of the designed controller
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