69 research outputs found
A CFD-based design methodology for hydraulic turbines applied to a case study in Turkey
Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Hydraulic turbines are turbo machines which produce
electricity from hydraulic energy. Francis type turbines are the
most common one in use today. The design of these turbines
requires high engineering effort since each turbine is tailor
made due to different head and discharge values. Therefore
each component of the turbine is designed specifically. During
the last decades, Computational Fluid Dynamics (CFD) has
become very useful tool to predict hydraulic machinery
performance and save time and money for designers. This
paper describes a design methodology to optimize a Francis
turbine by integrating theoretical and experimental
fundamentals of hydraulic machines and commercial CFD
codes.dc201
Conceptual design of a hydroelectric power plant for a rehabilitation project
This study presents the conceptual design of a hydroelectric
power plant, as a part of a large scale rehabilitation project for an
existing power plant in Antalya, Turkey. The aim of the
rehabilitation project is to increase the power and efficiency of
the plant and its scope includes CFD aided turbine design, model
production and tests, the design, production and implementation
of the turbine, generator and the SCADA system. This study is
the first attempt, as a preliminary study, to handle the problem
and perform a conceptual design of the hydroelectric power
plant. The existing plant is modeled to estimate the head and flow
rate characteristics at various sections of the system. The net
head and flow rate of the turbine are estimated. Transient
analyses of the system are also performed to evaluate water
hammer characteristics. The results of the transient analyses
provide the inputs for the design of by-pass pipeline and pressure
relief valve. The estimated net head and flow rate from the
simulations are used as inputs for the preliminary design. The
dimensions of the spiral case, the diameter of the stay vanes and
guide vanes, wicket gate heights, runner diameter and rotational
speed, runaway characteristics and preliminary output power are
determined. The best efficiency point and the design point of the
turbine are also obtained as the net head versus the flow rate.
These results provide an idea on the feasibility of the increase in
power.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016
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Whey protein mouth drying influenced by thermal denaturation
Whey proteins are becoming an increasingly popular functional food ingredient. There are, however, sensory properties associated with whey protein beverages that may hinder the consumption of quantities sufficient to gain the desired nutritional benefits. One such property is mouth drying. The influence of protein structure on the mouthfeel properties of milk proteins has been previously reported. This paper investigates the effect of thermal denaturation of whey proteins on physicochemical properties (viscosity, particle size, zeta-potential, pH), and relates this to the observed sensory properties measured by qualitative descriptive analysis and sequential profiling. Mouthcoating, drying and chalky attributes built up over repeated consumption, with higher intensities for samples subjected to longer heating times (p < 0.05). Viscosity, pH, and zeta-potential were found to be similar for all samples, however particle size increased with longer heating times. As the pH of all samples was close to neutral, this implies that neither the precipitation of whey proteins at low pH, nor their acidity, as reported in previous literature, can be the drying mechanisms in this case. The increase in mouth drying with increased heating time suggests that protein denaturation is a contributing factor and a possible mucoadhesive mechanism is discussed
Electrospun fluorescent nanofibers for explosive detection
Development of an instant on-site visual detection method for 2,4,6 trinitrotoluene (TNT) has become a significant requirement of the hour towards a secured society and a greener environment. Despite momentous advances in the respective field, a portable and reliable method for quick and selective detection of TNT still poses a challenge to many reasons attributing to inappropriate usage in subordinate areas and untrained personnel. The recent effort on the fluorescent based detection represents as one of easy method in terms of fast response time and simple on/off detection. Therefore, this chapter provides a consolidation of information relating to recent advances in fluorescence based TNT detection.Further, the main focus will be towards advances in the nanofibers based TNT detection and their reason to improving thesensitivity. © Springer International Publishing Switzerland 2015
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
20-Year Risks of Breast-Cancer Recurrence after Stopping Endocrine Therapy at 5 Years
The administration of endocrine therapy for 5 years substantially reduces recurrence rates during and after treatment in women with early-stage, estrogen-receptor (ER)-positive breast cancer. Extending such therapy beyond 5 years offers further protection but has additional side effects. Obtaining data on the absolute risk of subsequent distant recurrence if therapy stops at 5 years could help determine whether to extend treatment
Determination of alpha fetoprotein and alpha1 antitrypsin in patients with primary liver carcinoma (hepatoma) and cirrhosis
[No abstract available
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