646 research outputs found
Non-Invasive Radiofrequency-Induced Targeted Hyperthermia for the Treatment of Hepatocellular Carcinoma
Targeted biological therapies for hepatocellular cancer have shown minimal improvements in median survival. Multiple pathways to oncogenesis leading to rapid development of resistance to such therapies is a concern. Non-invasive radiofrequency field-induced targeted hyperthermia using nanoparticles is a radical departure from conventional modalities. In this paper we underscore the need for innovative strategies for the treatment of hepatocellular cancer, describe the central paradigm of targeted hyperthermia using non-invasive electromagnetic energy, review the process of characterization and modification of nanoparticles for the task, and summarize data from cell-based and animal-based models of hepatocellular cancer treated with non-invasive RF energy. Finally, future strategies and challenges in bringing this modality from bench to clinic are discussed
New cost control techniques in mega construction projects
The construction industry in the U.K. is a vital sector of the country's economy. However, this industry is faced by various types of uncertainties and risks due to their dynamic environment, particularly for megaprojects. The study aimed to determine the modern and effective cost control techniques that are utilized in for mega construction projects in the U.K. A mixed-method approach that involves both qualitative and quantitative approaches were adopted in this research for data collection and analysis. Five semi-structured interviews with construction professionals were conducted first to find out modern and effective techniques used for projects cost control. This is followed by carrying out Delphi survey twice with 42 and 39 construction professionals. Results revealed that the top five techniques that can be utilized for controlling megaproject costs were: Activity-based costing method, Contract Variance – Unit Costing, To-Complete Performance Index (TCPI), Cost-Value Reconciliation and BIM
Значення непрямого державного регулювання та саморегулювання у забезпеченні якості
В сфере регулирования качества во всём мире всё большее значение приобретают средства непрямого государственного регулирования и саморегулирования. Добровольными признаются стандарты и процедуры оценки соответствия (сертификация), расширяются масштабы деятельности саморегулируемых организаций. Статья посвящена исследованию развития этих процессов в Украине.In the whole world the means of the indirect state regulation and self-regulation have more and more significance in the sphere of the quality. The standards and procedures of conformity by assessment are considered to be voluntary, the scales of the self-regulation organization activity, in particular, consumer protection, are increased. The article is devoted to the research of these processes development in Ukraine
Fritz John Type Duality in Nondifferentiable Continuous Programming with Equality and Inequality Constraints
A Fritz John type dual for a nondifferentiable continuous programming problem with equality and inequality constraints which represent many realistic situations is formulated using Fritz John type optimality conditions instead of Karush-Kuhn-Tucker type conditions and thus does not require a regularity condition. Various duality results under suitable generalized convexity assumptions are derived. A pair of Fritz John type dual continuous programming with natural boundary conditions rather than fixed end points is also presented. Finally, it is pointed that our duality results can be considered as dynamic generalizations of those of a nondifferentiable nonlinear programming problem in the presence of equality and inequality constraints recently treated in the literature
TRM versus FRP in flexural strengthening of RC beams: behaviour at high temperatures
The flexural behaviour of RC beams strengthened with TRM and FRP composites was experimentally investigated and compared both at ambient and high temperatures. The investigated parameters were: (a) the strengthening material, namely TRM versus FRP, (b) the number of strengthening layers, (c) the textile surface condition (dry and coated), (d) the textile material (carbon, basalt or glass fibres) and (e) the end-anchorage of the flexural reinforcement. A total of 23 half-scale beams were constructed, strengthened in flexure and tested to assess these parameters and the effectiveness of the TRM versus FRP at high temperatures. TRM exhibited excellent performance as strengthening material in increasing the flexural capacity at high temperature; in fact, TRM maintained an average effectiveness of 55%, compared to its effectiveness at ambient temperature, contrary to FRP which totally lost its effectiveness when subjected to high temperature. In specific, from the high temperature test it was found that by increasing the number of layers, the TRM effectiveness was considerably enhanced and the failure mode was altered; coating enhanced the TRM effectiveness; and the end-anchorage at high temperature improved significantly the FRP and marginally the TRM effectiveness. Finally, the formula proposed by the Fib Model Code 2010 was used to predict the mean debonding stress in the TRM reinforcement, and using the experimental results obtained in this study, a reduction factor to account for the effect of high temperature on the flexural strengthening with TRM was proposed
Safety management in private construction project in Iraq
The construction industry consider one of the most dynamic industries due to the unique features such as the change in the project site and condition. These features make the application of specifications and codes more difficult. Occupational Safety requirements in project is also difficult to be implemented and monitored due to the unique features of this industry. The aim of the study is to propose a new method that will determine the performance and management of the occupational safety in the construction site, in order to increase the safety at work in the private construction sector in Iraq. Another purpose of this evaluation is to establish a fundamental point that can be graded according to the safety index for the Iraqi construction industry. The information has been collected through a checklist and a questionnaire; the study focused on data collection paradigm and framework based on a fuzzy logic approach, which is especially able to evaluate the efficiency and monitoring of management defects of private contractors in the fields of occupational safety management. The results show a high security management performance in the private construction sector in Iraq, and the survey results show that there is a great deficiency in training on job security, also study found out that the top three elements of occupational safety management in Iraq are: First Aid-medical needs, Safety committees, Hazard prevention and control
Live single cell analysis using synchrotron FTIR microspectroscopy: development of a simple dynamic flow system for prolonged sample viability
Synchrotron radiation Fourier transform infrared microspectroscopy (SR-microFTIR) of live biological cells has the potential to provide far greater biochemical and morphological detail than equivalent studies using dehydrated, chemically-fixed single cells. Attempts to measure live cells using microFTIR are complicated by the aqueous environment required and corresponding strong infrared absorbance by water. There is also the additional problem of the limited lifetime of the cells outside of their preferred culture environment. In this work, we outline simple, cost-effective modifications to a commercially available liquid sample holder to perform single live cell analysis under an IR microscope and demonstrate cell viability up to at least 24 hours. A study using this system in which live cells have been measured at increasing temperature has shown spectral changes in protein bands attributed to α-β transition, consistent with other published work, and proves the ability to simultaneously induce and measure biochemical changes. An additional study of deuterated palmitic acid (D31-PA) uptake at different timepoints has made use of over 200 individual IR spectra collected over ∼4 hours, taking advantage of the ability to maintain viable cell samples for longer periods of time in the measurement environment, and therefore acquire greatly increased numbers of spectra without compromising on spectral quality. Further developments of this system are planned to widen the range of possible experiments, and incorporate more complex studies, including drug-cell interaction
Bond between TRM versus FRP composites and concrete at high temperatures
The use of fibre reinforced polymers (FRP) as a means of external reinforcement for strengthening the existing reinforced concrete (RC) structures nowadays is the most common technique. However, the use of epoxy resins limits the effectiveness of FRP technique, and therefore, unless protective (thermal insulation) systems are provided, the bond capacity at the FRP-concrete interface will be extremely low above the glass transition temperature (Tg). To address problems associated with epoxies and to provide cost-effectiveness and durability of the strengthening intervention, a new composite cement- based material, namely textile-reinforced mortar (TRM) has been developed the last decade. This paper for the first time examines the bond performance between the TRM and concrete interfaces at high temperatures and, also compares for the first time the bond of both FRP and TRM systems to concrete at ambient and high temperatures. The key parameters investigated include: (a) the matrix used to impregnate the fibres, namely resin or mortar, resulting in two strengthening systems (TRM or FRP), (b) the level of high temperature to which the specimens are exposed (20, 50, 75, 100, and 150 °C) for FRP-reinforced specimens, and (20, 50, 75, 100, 150, 200, 300, 400, and 500 °C) for TRM-strengthened specimens, (c) the number of FRP/TRM layers (3 and 4), and (d) the loading conditions (steady state and transient conditions). A total of 68 specimens (56 specimens tested in steady state condition, and 12 specimens tested in transient condition) were constructed, strengthened and tested under double- lap direct shear. The result showed that overall TRM exhibited excellent performance at high temperature. In steady state tests, TRM specimens maintained an average of 85% of their ambient bond strength up to 400 °C, whereas the corresponding value for FRP specimens was only 17% at 150 °C. In transient test condition, TRM also outperformed over FRP in terms of both the time they maintained the applied load and the temperature reached before failure
Characterizing the hydraulic properties of paper coating layer using FIB-SEM tomography and 3D pore-scale modeling
AbstractPaper used in the printing industry generally contains a relatively thin porous coating covering a thicker fibrous base layer. The three-dimensional pore structure of coatings has a major effect on fluid flow patterns inside the paper medium. Understanding and quantifying the flow properties of thin coating layers is hence crucial. Pore spaces within the coating have an average size of about 180nm. We used scanning electron microscopy combined with focused ion beam (FIB-SEM) to visualize the nano-scale pore structure of the paper coating layer. Post-processing of the FIB-SEM images allowed us to reconstruct the three-dimensional pore space of the coating. The 3D FIB-SEM images were analyzed in detail to obtain pore size distribution and porosity value. The permeability was estimated using the GeoDict software, based on solutions of the Stokes equation. By determining the porosity and permeability of increasingly larger domain sizes, we estimated the size of a representative elementary volume (REV) for the coating layer to be 60µm3, which is well within the volume analyzed using FIB-SEM. The estimated porosity and permeability of the REV domain were 0.34 and 0.09 mDarcy, respectively. Using the pore morphology method, capillary pressure-saturation (Pc-S) and relative permeability curves of the REV domain could be constructed next. The Pc-S curves showed that the coating had a high air entry suction, which is very favorable for printing in that ink will invade the coating as soon as it is applied to the coating. Our results are essential for macroscale modelling of ink penetration into a coating layer during inkjet printing. Macroscopic models can be valuable tools for optimization of the penetration depth and the spreading of ink on and within paper substrates
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