A new method for predicting viscosity of pure organic liquids

A new semi-theoretical method based on Enskog's hard sphere theory for dense fluids and the principle of corresponding states is presented for predicting viscosity of pure organic liquids. The viscosities of 75 organic liquids—37 acyclic and 38 cyclic hydrocarbons—were calculated using this method which requires critical properties and normal boiling point as input data. The predictions were compared with empirical data and other prediction methods. Highly satisfactory results were obtained over a wide range of temperatures (0.45 < T_r< 0.80).     

A computer-based system for environmental impact assessment (EIA) applications to energy power stations in Turkey: ÇEDINFO

Environmental impact assessment (EIA) is a tool for decision makers to take into account the possible effects of a proposed project on the environment and is also a process for collecting the data related to a project design and project area. Different techniques are used for the EIA process. In recent years, including the design and development of databases, classification systems, computer models and expert systems have been used extensively in impact assessment studies. Knowledge-based systems referred to as expert systems and different computer-based systems are an emerging technology in information processing and are becoming increasingly useful tools in different applications areas including EIA studies. Their use for EIA has been quite limited in developing countries, because of the constraints on resources, particularly in expertise and data.

In this study, a knowledge-based software—ÇEDINFO—developed by authors was introduced. ÇEDINFO to be used for EIA practices on energy-generating stations was designed based on the legal EIA process in Turkey. According to the EIA Regulation enacted in Turkey in 1993, energy-generating stations (thermal power station, hydraulic station, nuclear station) in different categories require mandatory EIA reports duly approved by The Ministry of Environment and Forestry before their construction. ÇEDINFO primarily aims to provide educational support for EIA practices and decision-makers on energy-generating stations.     

In situ processing of TiCp-Al composites by reacting graphite with AI-Ti melts

Aluminum has been a key material, particularly in the aerospace and automotive industries, owing to its low density, high specific strength, good corrosion resistance and recyclability. Aluminum based metal matrix composites have also become attractive candidates for various applications where monolithic aluminum alloys cannot meet the strict design requirements. Recently, particulate reinforced aluminum composites have attracted a great deal of attention. Among various techniques which have been employed in the synthesis of these composites, incorporation of the reinforcing phase particles directly into the melt is practical and economic; yet it is not trouble-free. In situ processing of particulate reinforced composites, on the other hand, yields superior microstructures and thus better properties. In the present work, such a method to manufacture TiC_p-Al composites and the microstructures obtained thereof will be described.     

Production of Al–Ti–B master alloys from Ti sponge and KBF4

It is of great interest to replace the K₂TiF₆ salt so as to reduce the volume of fluoride-bearing particulate material to be added to the aluminium melt in the popular “halide salt” process. Ti sponge was used in the present work as the source of Ti in the production of an Al–5Ti–1B grain refiner. Addition of Ti granules into molten aluminium, either premixed with or before KBF₄ salt, has produced Al–5Ti–1B alloys where the boride particles were relatively few and predominantly of the AlB₂ type. The grain refining efficiency of these alloys were far from satisfactory. TiB₂ was the dominant boride phase with sufficient number of blocky aluminide particles when Ti, in excess of the TiB₂ stoichiometry was supplied before hand and the balance was reserved for co-addition with KBF₄. Al₃Ti particles were generated soon after the Ti solubility limit was exceeded in the first step while the boride particles were subsequently produced by the reaction between molten aluminium, KBF₄ and K₂TiF₆. The Al–5Ti–1B master alloy thus produced provided an adequate grain refining performance while the amount of particulate material to be added to the aluminium melt was reduced by nearly 30%.     

Electrochemical synthesis of sulfonated polypyrrole in FSO3H/acetonitrile solution

The incorporation of SO₃^? groups into a polypyrrole backbone was successfully carried out using FSO₃H/acetonitrile medium. The degree of sulfonation (sulfonation or sulfur‐to‐nitrogen ratio) of polymer was controlled by varying FSO₃H concentration while the film was being electrodeposited. The cyclic voltammograms of the electrodeposited films were taken between ?1.00 and +2.00 V (versus Ag/AgCl) in blank solution. A substantial effect on the electrical conductivity was observed upon the incorporation of SO₃^? groups in the polypyrrole polymeric chain. The elemental analysis results of the freshly prepared and reduced films give independent evidence that the SO₃^? groups are covalently bound to the structure. FTIR, UV‐Vis, spectroscopy and SEM techniques were used to characterize the electrosynthesized polypyrrole films. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 526–533, 2004     

Determination of conjugated linolenic acid content of selected oil seeds grown in Turkey

Seeds originating from some Turkish sources were analyzed with respect to their characteristics and FA compositions. These seeds represented pomegranate (Punica granatum L.), bitter grourd (Momordica charantia L.), pot marigold (Calendula officinalis L.), catalpa (Catalpa bignonoides), bourdaine (Rhamnus frangula L.), Oregon grape (Mahonia aquifolium), sarsaparilla (Smilax aspera), mahaleb (Prunus mahaleb L.), black-thorn (Prunus spinosa L.), cherry laurel (Prunus laurocerasus L.), and firethorn (Pyracantha coccinea). Bitter gourd and bourdaine seeds contain more than 20% oil. Catalpa, bourdaine, Oregon grape, blackthorn, and cherry laurel seed oil contents ranged from 15 to 20%. In the seeds from plants belonging to the Rosacea family, oil content ranged from 4.5 to 18.5%. Among the seed oils analyzed, pot marigold had one of the lowest oil contents (5.9%). Pomegranate contained the highest amount of total conjugated linolenic acid (CLNA) (86.0%). Seed oils of bitter grourd, pot marigold, mahaleb, and catalpa were rich in CLNA: 60.0, 29.5, 27.6, and 27.5%, respectively. Bourdaine, Oregon grape, and sarsaparilla seeds contained low amounts of CLNA. On the other hand, mahaleb, bourdaine, catalpa, Oregon grape, sarsaparilla, cherry laurel, blackthorn, and firethorn seed oils are basically oleic and linoleic acid-rich oils and therefore have little drying ability (semidrying oil). The results show a potential for the use of endogenous Turkish seeds as a source of CLNA.     

Doppler velocimetry of the uterine arteries after hysteroscopic rollerball endometrial ablation

The aim of this study was to document the Doppler indices [pulsatility index (PI) and resistance index (RI)] of the uterine arteries in 30 patients who underwent hysteroscopic rollerball endometrial ablation for dysfunctional uterine bleeding by transvaginal pulsed Doppler sonography, and to reveal whether treatment failures (persistent menometrorrhagia) can be predicted by the blood flow characteristics of the uterine arteries in advance. On the basis of the outcome of patients at the end of the first postoperative year, the Doppler indices of the uterine arteries were meaningful 1 year after the operation when PI (1.32 +/- 0.11; mean +/- SD) and RI (0.71 +/- 0.04) in six menometrorrhagic patients were statistically different from PI (2.19 +/- 0.28; 1.95 +/- 0.36 and 1.82 +/- 0.37) and RI (0.87 +/- 0.06; 0.82 +/- 0.06 and 0.81 +/- 0.04) in normally menstruating, amenorrhoeic and hypomenorrhoeic patients respectively (P < 0.05). On the other hand, the patients who would be menometrorrhagic one year after the operation had a thicker endometrium in the first post-operative month. These findings suggest that the angiogenetic role of the persistent endometrial islands after endometrial ablation needs at some time to be reflected as changes in the Doppler parameters of the uterine arteries.     

Measurement of thermal neutron cross section and resonance integral for (n,γ) reaction in Sm

This study implies that ⁵⁵Mn(n,γ)⁵⁵Mn monitor reaction may be a convenient alternative comparator for the activation method and thus, it was used for the determination of thermal neutron cross section (TNX) and the resonance integral (RI) of the reaction ¹⁵²Sm(n,γ)¹⁵³Sm. The samples of MnO₂ and Sm₂O₃ diluted with Al₂O₃ powder were irradiated within and without a cylindrical 1 mm-Cd shield case in an isotropic neutron field obtained from the ²⁴¹Am–Be neutron sources. The γ-ray spectra from the irradiated samples were measured by high resolution γ-ray spectrometry with a calibrated n-type Ge detector. The correction factors for γ-ray attenuation, thermal neutron and resonance neutron self-shielding effects and epithermal neutron spectrum shape factor (α) were taken into account in the determinations. The thermal neutron cross section for ¹⁵²Sm(n,γ)¹⁵³Sm reaction has been determined to be 204.8 ± 7.9 b at 0.025 eV. This result has been obtained relative to the reference thermal neutron cross section value of 13.3 ± 0.1 b for the ⁵⁵Mn(n,γ)⁵⁶Mn reaction. For the TNX, most of the experimental data and evaluated one in JEFF-3.1, ENDF/B-VI, JENDL 3.3 and BROND 2.0, in general, agree well with the present result. The RI value for ¹⁵²Sm(n,γ)¹⁵³Sm reaction has also been determined to be 3038 ± 214 b, relative to the reference value of 14.0 ± 0.3 b for the ⁵⁵Mn(n,γ)⁵⁶Mn monitor reaction, using a 1/E^1+α epithermal neutron spectrum and assuming Cd cut-off energy of 0.55 eV. In surveying literature, the existing experimental and evaluated data for the RI values are distributed from 1715 to 3462 b. However, when the Cd cut-off energy is defined as 0.55 eV, the present RI value agrees with some previously reported RI values, 3020 ± 163 b by Simonits et al., 3141 ± 157 by Van Der Linden et al., and 2962 ± 54 b by Kafala et al., within the limits of error.     

Measurement of thermal neutron cross-section and resonance integral for the Yb(n,γ)Yb reaction by the cadmium ratio method

The thermal-neutron cross-section and the resonance integral for the ¹⁷⁴Yb(n,γ)¹⁷⁵Yb reaction were measured by the activation method using a ⁵⁵Mn monitor as single comparator. Analytical grade MnO₂ and Yb₂O₃ powder samples with and without a cylindrical 1 mm Cd shield box were irradiated in an isotropic neutron field obtained from three ²⁴¹Am-Be neutron sources. The gamma-ray spectra from the activated samples were measured with a calibrated n-type high-purity Ge detector. The experimental results were corrected for the correction factors calculated for thermal and epithermal neutron self-shielding effects, epithermal neutron spectrum shape and gamma-ray self attenuation. Thus, the thermal neutron cross-section for the ¹⁷⁴Yb(n,γ)¹⁷⁵Yb reaction is found to be 126.5 ± 6.6 b, relative to that of the ⁵⁵Mn monitor. The resonance integral value for the ¹⁷⁴Yb(n,γ)¹⁷⁵Yb reaction is found to be 59.6 ± 8.5 b, at cadmium cut-off energy of a 0.55 eV. Using the measured cadmium ratios of ⁵⁵Mn and ¹⁷⁴Yb, the result for resonance integral of the ¹⁷⁴Yb(n,γ)¹⁷⁵Yb reaction has also been obtained relative to the reference value of the ⁵⁵Mn monitor. The present results for the ¹⁷⁴Yb(n,γ)¹⁷⁵Yb reaction agree well only with the recent experimental ones obtained by Kafala et al. [1] and De Corte and Simonits [2] within uncertainty limits. However, the previously reported experimental data for the thermal neutron cross-section for this reaction are distributed between 24 and 141 b, and similarly the experimental values for the resonance integral value also show a large scatter in the range of 30-69 b.