2D Model of Guide Vane for Low Head Hydraulic Turbine： Analytical and Numerical Solution of Inverse Problem

Low-head hydraulic turbines are the subjects to individual approach of design. This comes from the fact that hydrological conditions are not of a standard character. Therefore, the design method of the hydraulic turbine stage has a great importance for those who may be interested in such an investment. As a first task in a design procedure the guide vane is considered. The proposed method is based on the solution of the inverse problem within the flame of 2D model. By the inverse problem authors mean a design of the blade shapes for given flow conditions. In the paper analytical solution for the simple cylindrical shape of a guide vane is presented. For the more realistic cases numerical solutions according to the axis-symmetrical model of the flow are also presented. The influence of such parameters as the inclination of trailing edge, the blockage factor due to blade thickness, the influence of loss due to dissipation are shown for the chosen simple geometrical example.     

Evaluation of ethanol fermentation parameters for bioethanol production from sugar beet pulp and juice

The aim of this study was to investigate the efficient utilization of sugar beet pulp, as well as raw, concentrated raw and thick sugar beet juice, for bioethanol production. Different fermentation conditions were examined. The influence of raw material pre‐treatment (pasteurization or sterilization), type of batch culture process (stationary or shaken) as well as the type of Saccharomyces cerevisiae yeast preparation on the yields of the process were studied. Moreover, the fermentation process effectiveness was examined in connection with the quality of the obtained distillates. Sterilization, stationary batch culture and Safdistil C‐70 yeast preparation were identified as the most profitable factors for sugar beet pulp fermentation, providing a high fermentation efficiency and ethanol yield (87.7% of theoretical ethanol yield). Concentrated raw beet juice resulted in a value of 94.2% of theoretical yield, and thick juice a 92.6% yield. The results suggest that bioethanol production from sugar beet pulp and sugar beet juice has promise as an alternative fuel. The raw spirits obtained from the sugar beet juice were characterized as having the lowest quantity of volatile by‐products. Copyright © 2014 The Institute of Brewing & Distilling     

Influence of Variety,Moisture Content,Kernel Size and Applied Current Frequency on the Electric Properties of Wheat Grain

The work aimed at determination of electric properties of wheat grain in dependence on its variety, moisture, geometrical features of kernels and applied current frequency. Wheat grain of 4 Polish winter varieties: Korweta, Juma, Mikon and Kobra from harvest 2001 were used as the material for study. Grain was sized into 3 fractions: (1) > 2,8mm, (2) 2,5–2,8mm, and (3) 2,2–2,5mm. Basic geometrical features were determined for not sorted grain (control sample) and its three fractions by the use of digital image analysis. Electric properties of grain (at 11% and 15% moisture content) have been performed with the Hewlett Packard 4263B meter. Measurements of impedance, resistance, admittance, conductance, as well as equivalent parallel capacitance and equivalent series capacitance were made. Obtained results were subjected to statistical analysis with the use of Statistica? programme. Changes in electric properties of grain significantly depended on all of studied factors. Most of all significant correlations appeared between geometrical features and studied electric properties of grain of 15% moisture. Statistical analysis of the results proved significant linear correlations between electric properties of kernels and their length, perimeter and circularity coefficient R_C2 at higher measurement frequencies.     

Photocrosslinking of solvent-based acrylic pressure-sensitive adhesives (PSA) by the use of selected photoinitiators type I

This study investigated the photocrosslinking of solvent-based acrylic pressure-sensitive adhesives (PSA) containing selected photoinitiators type I, known as α-cleavage photoinitiators. Photocrosslinking of PSA, especially of acrylic PSA, is well established crosslinking process using the UV radiation technology. UV-initiated crosslinking of acrylic PSA allows the synthesis of the wide range of UV-crosslinkable PSA with the interesting features. Especially, the important balances of properties such as adhesive and cohesive strength which are typically critical for the application performance can be achieved by this technology. The selection of suitable photoinitiator plays an important role to obtain the optimum properties of acrylic PSA including tack, peel adhesion, and shear strength. In this study, the investigations on different saturated conventional photoinitiators of type I for solvent-based PSA were carried out. The effects of photoinitiator concentration, UV crosslinking time and UV dose on the tack, peel strength, and shear strength were explored in detail for guiding the choice of photoinitiators to fabricate advanced PSA for industrial usage.     

Current Philosophy of Sustainability in Civil Engineering

This paper describes the current status of sustainable development in civil engineering. The discussion covers economy along with “global village” needs, and is supported by information about technology standards combined with notions of ethics, environment, aesthetics, and heritage—the philosophical understanding of the cultural landscape of the society. It is recognized that “true development” cannot be limited to purely technical problems; “human ecology” should be taken into account. The concepts of sustainable development require input from all mankind, but civil engineering professionals can play a particular role here; their spiritual motivation can often be a decisive argument for their material handling. This means that “true development,” referred to as the dignity of man, must be based on the priority of spirit versus matter, of person versus object, of ethics versus technology.     

A comparative study of chelating and cationic ion exchange resins for the removal of palladium(II) complexes from acidic chloride media

The increasing demand for palladium for technological application requires the development of ion exchange chromatography. Recently ion exchange chromatography has developed largely as a result of new types of ion exchangers available on the market of which two types are widely applied. One of them are selective (chelating) and modified ion exchangers and the other one are liquid exchangers. Two types of ion exchange resins such as chelating (Lewatit TP 214, Purolite S 920) and cationic (Chelite S, Duolite GT 73) ion exchangers are used for the recovery of palladium(II) complexes from chloride media (0.1-2.0M HCl-1.0M NaCl-0.0011 M Pd(II); 0.1-2.0M HCl-2.0M NaCl-0.0011M Pd(II)). The influence of concentration of hydrochloric acid, sodium chloride as well as the phase contact time on the degree of recovery of palladium(II) complexes was studied. Moreover, the amount of palladium(II) chlorocomplexes sorbed onto ion exchangers, the working ion exchange capacities and the weight and bed distribution coefficients were calculated in order to judge which of two types of resins possesses the best performance towards palladium(II) complexes.     

The influence of distribution of titanium alloyed into carbon ceramics by the intense plasma pulses on their surface wettability with liquid copper

The paper presents an analysis of wettability and structural properties of the near surface layer of carbon ceramics into which titanium atoms were alloyed using a new method based on the use of high intensity pulsed plasma beams. The influence of various parameters of ceramic pre-treatment process on their wettability with liquid copper is presented and discussed. The information obtained can be useful in designing the ceramic–metal joints and composites.     

Surface morphology of steel and titanium induced by ion beam bombardment – Comprehensive analysis

It is well known that ion bombardment of solid surface modifies its physical and chemical properties, among others, surface morphology. In this paper we try to concentrate on four aspects of ion beam induced surface morphology, i.e.: (a) surface topography, (b) surface roughness, (c) rate of profile shape variability, and (d) surface morphology arrangement. Surface topographies (in micro- and nanometre range) were observed by means of scanning electron and near-field microscopes. High quality profilograph and atomic force microscope were utilised to measure surface roughness parameters. To do that, surface profiles must be well known. To detect any profile shape alteration during ion beam bombardment we used fractal analysis, and especially fractal dimension D that can give information about rate of profile shape variability. Surface morphology arrangement, i.e. a question whether it is random or determined, was studied with the use of frequency plots resulting from harmonic analysis of profiles.We studied surface topographies, selected roughness parameters, fractal dimensions and frequency plots relating to stainless steel and polycrystalline 99.5% titanium bombarded with perpendicular low energy (800 eV) broad argon ion beam as well as neutralized narrow argon or krypton ion beam (up to 6 keV).     

Inhomogeneous structure of near-surface layers in the ion-implanted NiTi alloy

This paper reports the application of nitrogen ion implantation for modification of a shape memory alloy. It is known that the problem of creating a protective surface coating for the shape memory alloy is the most acute for potential applications of this material. Thus, the problem of increasing surface protective properties and, at the same time, simultaneous preservation of functional properties of shape memory materials is a subject of research and development [Pelletier H, Muller D, Mille P, Grob J. Surf Coat Technol 2002;158:309.]. The surface characterization of nitrogen implanted (fluence 10¹⁸ cm^?2 and energy 50 keV) equiatomic commercial NiTi alloy samples was performed with the assistance of high resolution transmission electron microscopy (HTEM) techniques and modifications of phase composition before and after irradiation are studied at room and martensitic transformation temperatures by X-ray diffraction methods. Differential scanning calorimetry (DSC, TA Instruments) was used to characterize the transformation sequence and transformation temperatures for the initial and surface-modified materials. Experimental results of an inhomogeneous structure of near-surface layers in the ion-implanted NiTi alloy are discussed in this paper.