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

Tannin- caprolactam and Tannin- PEG formulations as outdoor wood preservatives: Weathering properties

International audienceAbstractKey messageThis article presents the leaching, fire and weathering resistance improvements of samples treated with tannin-based wood preservatives added of caprolactam. PEG-added formulations show limited applicability. The FT-IR and13C-NMR analyses of the caprolactam-added formulations show some evidences of copolymerization.ContextTannin-boron wood preservatives are known for their high resistance against leaching, biological attacks, fire as well as for the good mechanical properties that they impart to wood. These properties promoted these formulations for being a candidate for the protection of green buildings. However, the low elasticity of these polymers and their dark colour implied limited weathering resistances.AimsThe aim of the study is to find suitable additives for tannin-based formulations to overcome their limited weathering resistances, without compromising the other properties.MethodsTreatment, leaching and fire tests, dimensional stability as well as artificial and natural weathering of the timber treated with caprolactam-added and PEG-added formulations were performed. FT-IR and 13C-NMR of the formulations were presented.ResultsThe presence of caprolactam improved the properties of the formulation with particularly significant results in terms of resistance against leaching and dimensional stability. These enhancements were imparted also to the weathering resistance of the tannin-caprolactam formulations. Indeed, the colour changes during the artificial and natural exposures were stable for longer periods. FT-IR and 13C-NMR investigations of the advanced formulations were led, and covalent copolymerization of the caprolactam with the tannin-hexamine polymer was observed.ConclusionThe tannin formulations with caprolactam improved the durability of the wood specimens, while the PEG-tannin presented strong application drawbacks

Acoustic Overexposure Increases the Expression of VGLUT-2 Mediated Projections from the Lateral Vestibular Nucleus to the Dorsal Cochlear Nucleus

The dorsal cochlear nucleus (DCN) is a first relay of the central auditory system as well as a site for integration of multimodal information. Vesicular glutamate transporters VGLUT-1 and VGLUT-2 selectively package glutamate into synaptic vesicles and are found to have different patterns of organization in the DCN. Whereas auditory nerve fibers predominantly co-label with VGLUT-1, somatosensory inputs predominantly co-label with VGLUT-2. Here, we used retrograde and anterograde transport of fluorescent conjugated dextran amine (DA) to demonstrate that the lateral vestibular nucleus (LVN) exhibits ipsilateral projections to both fusiform and deep layers of the rat DCN. Stimulating the LVN induced glutamatergic synaptic currents in fusiform cells and granule cell interneurones. We combined the dextran amine neuronal tracing method with immunohistochemistry and showed that labeled projections from the LVN are co-labeled with VGLUT-2 by contrast to VGLUT-1. Wistar rats were exposed to a loud single tone (15 kHz, 110 dB SPL) for 6 hours. Five days after acoustic overexposure, the level of expression of VGLUT-1 in the DCN was decreased whereas the level of expression of VGLUT-2 in the DCN was increased including terminals originating from the LVN. VGLUT-2 mediated projections from the LVN to the DCN are likely to play a role in the head position in response to sound. Amplification of VGLUT-2 expression after acoustic overexposure could be a compensatory mechanism from vestibular inputs in response to hearing loss and to a decrease of VGLUT-1 expression from auditory nerve fibers

Takayasu arteritis presenting with fever of unknown origin - Two case reports

Two patients with Takayasu arteritis are reported who presented with fever of unknown origin. Takayasu arteritis was diagnosed at the prepulseless period after stenotic lesions of the aorta, and its branches were seen with imaging methods. In the first month of steroid treatment, hypertension developed in both patients that was related to fibrosis in stenotic lesions in renal arteries. Both patients were treated with percutaneous transfemoral renal angioplasty. Takayasu arteritis should be considered in the differential diagnosis of fever of unknown origin, especially in young women. Absence of the physical findings related to vasculitic lesions will not rule out the disease, which can be seen in the prepulseless period