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This paper aims to study the behaviour of lightweight R.C. beams under different loads. Six R.C. beams were cast with dimensions of 200 × 250 mm and a length of 1800 mm. These R.C. beams were divided according to their compressive strength: the first group consisted of three beams with normal compressive strength lightweight concrete, and the second group consisted of three beams with high compressive strength lightweight concrete. Also, these beams were divided according to the type of applied load (pure torsion behaviour, flexural behaviour, or combined flexural and torsion behaviour). The load–deflection curve was recorded for R.C. beams subjected to a flexural load, and the torsional moment-twist angle curves were also recorded for R.C. beams subjected to combined bending and torsion as well as pure torsion. Also, by using the digital image correlation D.I.C to investigate the strain behaviour of R.C. beams. By using the ABAQUS software, the results of the experiment were calibrated. After that, the ABAQUS program is used to model the finite element model and carry out a parametric study. This study produced twelve normal and high-strength ordinary concrete beams to compare them with the practical results of lightweight concrete beams. According to the numerical results, the strength and deformation capacity of the ordinary concrete R.C. beam with both normal/high compared to the lightweight concrete R.C. beams improved by approximately 1.21, 1.28, 1.02, 1.07, 1.158, and 1.06, respectively. Additionally, raising the ratio of flexural reinforcement significantly impacts the beams’ capacity load.

In situ emulsification/solubilization is an oil recovery technique routinely used to mobilize residual oil after the secondary oil production (waterflooding). The oil is produced after a subsequent reduction of interfacial tension between stranded crude oil and water in the reservoir. Herein, a recovery method is presented for heavy crude oils whose scheme consists of injection of a fully solubilized (or emulsified) oil. Theoretically, the fully solubilized oil, referred hereinafter as microemulsion formulation, reduces the viscous forces that keep residual oil stranded. Different microemulsion formulations were prepared ex situ from two heavy oils (API 11.5 and 16.6), micellar slugs (formulated from cationic Gemini surfactant), and low-saline water (0.1 wt % NaCl). Tertiary heavy oil recovery consisted of displacing residual oil from a waterflooded core by a specific microemulsion formulation followed by low-saline water, which acted as buffer solution. Thirty-one percent of initial oil-in-place (IOIP) was recovered from the waterflooded core by microemulsion followed by an incremental oil recovery of about 20% of IOIP with chase water. The oil recovery efficiency by microemulsion and chase water floodings was lowered to 15 and 28%, respectively, in a strong oil-wet core (i.e., non waterflooded core). Despite the promising results presented herein, the performance of the microemulsion formulations and thus the oil recovery efficiency were found to be strongly dependent on (1) the nature of the core, i.e., its mineralogy, (2) the wetting state of plug, and (3) the chemical composition advancing fluid. The microemulsion formulations prompted a series of chemical reactions which subsequently altered their performance as a displacing agent. Ion tracking analysis of the effluent fractions showed that the pH and concentration in divalent and/or monovalent ions were also altered at each stage of production. When the plug was not waterflooded, the oil was produced along with a deposit of sludge and a high emulsion cut. However, the use of preflush enriched with an alkali (Na2CO3) was found to abate both effects. Furthermore, the spectral analysis of effluent fractions revealed the formation of calcium bridges which are thought to alter the efficiency of microemulsion formulations. Also, a series of chemical schemes are proposed in this investigation to support these results. Lastly, this investigation proposes a simplified electrostatic model that explains further the formation of clusters which were promoted by propagation of displacing fluids.

The competitiveness of the global market and availability of multiple outsourcing options have greatly increased the complexity of making ‘good’ outsourcing decisions. Improving the decision-making process when faced with a complex decision situation requires a systematic decision-making framework. We propose such a framework for making strategic manufacturing outsourcing decisions that benefits from prominent decision analysis tools. We envision a multiple factor outsourcing decision model and specifically advocate the use of We have developed a procedure for dividing the outsourcing choices into dominated and non-dominated sets, and rank ordering the elements of non-dominated set to identify the best strategy.

The use of quantum dots (QDs) for different applications such as biomarkers has increased in the past decade. Here we report on the uptake of fluorescent QDs into agricultural soil, and transport following their ingestion by the larvae of some common lepidopteran insects. Some QDs were leached through soil but their emission was quenched due to geo-effect. In contrast, fluorescence was still seen in leafroller larvae fed with these QDs and in their frass. Abbreviations: QD, quantum dot; NPs, Nanoparticles; Cys, cysteine; Gly, glycine; MPA, mercaptopropionic acid; MSA, mercaptosuccinic acid; AM, 2-aminoethanethiol; Na2EDTA, ethylenediaminetetraacetic acid disodium salt; PV, pore volume

To further examine the reliability of categorical loudness scaling (CLS) for individual loudness categories and for the slope of the CLS functions. And, to evaluate the relationship between CLS and audiometric threshold.

Considerable attention is now being paid to the use of rivers and lakes for such purposes as fishing, aquatic life and esthetical enjoyment.A study of the water quality of the Tigris River in Mosul city, North Iraq, was carried out in order to assess the chemical composition and suitability for fisheries and aquatic life.Laboratory analysis of 9 water samples for three sites within the rivers reach were performed in order to obtain the chemical concentration of Ca, Na, Mg, HCO3, SO4, Cl, NO3, NO2, TDS and pH. Certain ions may be lethal to fish and other aquatic lifeforms when present at levels near or below the limit given by public water supplies. Copper, zinc and aluminum, which are not among the metals for which limits are prescribed for public water supply, are toxic to fish and many other species of aquatic life. Concentration of chemical constituents in water samples vary spatially and temporarily.The chemical analysis of the water samples was compared with the standard guideline values as recommended by the World Health Organization (WHO) for fisheries and aquatic life. Three samples from the right bank of the river fell within the poor quality type for water. While the other samples from the left side and the deepest part of the river fell within the high quality type water.

This work presents the successful noncovalent attachment of ∼5 nm diameter cadmium−sulfur−selenium (CdSSe) quantum dots on strips of anatase TiO2nanobelts. The TiO2nanobelts were hydrothermally synthesized from a strong alkaline solution and subsequently heat-treated to achieve the anatase phase. The self-assembled-monolayer (SAM) technique was employed to attach the quantum dots onto the nanobelts. Due to the hydrophobic nature of the quantum dots, the surface of the nanobelts was first self-assembled with a layer of hydrophobic organic layer before both mixtures were added together. The resulting nanostructure assembly and composition was confirmed via transmission-electron-microscopy (TEM) imaging, Raman spectroscopy, UV−visible absorption spectroscopy (UV−vis), and X-ray photoelectron spectroscopy (XPS). Both Raman and UV−vis spectroscopies indicate evidence of interactions between the quantum dots and nanobelts. The visible-light sensitizing effect of the quantum dots was demonstrated in photocurrent experiments.

The synthesis of several new bismuth porphyrin complexes BiporX containing the tpp or tpClpp (tpClpp 5,10,15,20-tetra-p-chlorophenylporphyrin) porphyrin ligand and anions X NO3, Cl, Br, I are described. Molecular structures reported for BitpClppX for X Cl, Br show that the complexes crystallise as centrosymmetric dimers doubly bridged through Cl or Br. BitpClppNO3 crystallises as a less symmetric dimer in which one NO3ligand bridges the two bismuth centres and the second NO3ligand interacts with only one bismuth atom. In all three structures the bismuth atoms are significantly displaced from the porphyrin N4planes and the Bi–halide or Bi–O distances are very long.

A series of mixed-ligand–titanium complexes is reported which incorporate a tridentate N-methyldiethoxoamine (mdea) ligand in conjunction with chelating diolate ligand. X-ray crystal structures of the complexes [Ti(mdea) (O-O)]2 (where O-O = OC(CH3)2C(CH3)2O (1), OC(C2H5)2C(C2H5)2O (2), OC(CH3)2CH2CH(CH3)O (3), and OC(CH3)2CH2C(CH3)2O (4)) show them to exist as dimers in the solid state, with one arm of the aminodialkoxy ligand μ-bridging two titanium centres. Solution-state 1H and 13C NMR studies concur with the solid-state structures of (1)–(4) at low temperature. The room-temperature spectra of (3) and (4) suggest that bridging bond scission and reformation occurs increasing the apparent symmetry of the complexes. Complexes (3) and (4) dissociate into monomers in the vapour phase. The influence of the diolate ligand on the bridging bond strengths is discussed.

TiO₂ (anatase)-based photocatalyst powders containing up to 20 mol% calcium, strontium or barium ions were prepared from α-titanic acid by calcining gels prepared from triethanolamine-based sols at 600 °C. The powders were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance ultraviolet spectrophotometry, nitrogen sorption porosimetry and in situ infrared spectroscopy to examine surface adsorbed species. Compositions containing greater than 15 mol% alkaline earth ions resulted in largely amorphous materials. The residual anatase showed decreased crystallite sizes and increased crystallographic cell volumes with increasing concentration of alkaline earth ions, while the BET surface areas of the materials increased from around 80 m² g⁻¹ (no additive) to 160 m² g⁻¹ at higher levels of additive. Electronic spectroscopy showed that the band gaps of the materials increased with increasing Ca²⁺ content, due to the decreasing particle sizes. Under the synthesis conditions used, no other crystalline phase was observed, except rutile (< 1% w.r.t. anatase). The photocatalytic decomposition of oxalic acid was used as a model system to determine the relative influences of the additives on the photocatalytic activities. Titania containing 20 mol% alkaline earth ions showed approximately double the photocatalytic activity of similarly prepared anatase without additive. Half of the enhancement occurred for titania samples containing only 2 mol% alkaline earth ions. Comparisons of the physico-chemical properties of the photocatalysts with oxalic acid decomposition rates were carried out to determine the factors influencing the photocatalytic activity.

A method for producing amino alcohol complexes of titanium from hydrated titania (α-titanic acid) is described. Thus hydrated titania was completely converted into triethanolamine and diethanolamine complexes during reaction at 120°C for 6 h. This represents a synthetic method for titanium sol–gel precursors which are free from chlorine-containing impurities. Products were characterized with assistance from 1H and 13C nuclear magnetic resonance spectroscopy, and electrospray mass spectrometry. A single-crystal X-ray structure of titanium bis[2,2´- (methyl-imino)ethanolate], tetragonal, space group P4 – 2 1c, is presented. The titanium centre is coordinated by an N2O4donor set which can be most closely described as a bifacially capped tetrahedral geometry.

AbstractObjective: The aim of the study is to evaluate the DNA image analysis of smears in assessing spermatogenesis and to compare it to routine fine-needle aspiration cytology (FNAC). Methods:A total of 33 testicular needle aspirates from azoospermic infertile patients were blindly studied by 2 different cytologists separately; one studied the FNAC and the other evaluated the DNA contents. DNA image analysis was done on Feulgen-stained cytology smears. The generated DNA histogram was compared to cytology results. Results:Twenty-three (69.7%) testes showed complete agreement between the image analysis and cytology mainly in the presence of sperms, while 10 (30.3%) testes showed discrepancy between the DNA image analysis and cytology, mainly in the syndrome with Sertoli cells only and spermatogenic arrest. Conclusions:DNA image analysis of testicular aspirates is an objective and reliable method in assessing spermatogenesis, while cytology is a relatively subjective method and observer dependent. The discrepancy may be explained by cytologist inter- and intra-observer variability in evaluating spermatogenesis in the FNAC specimens.Copyright © 1999 S. Karger AG, Basel

A highly fluxional dititanium N-methyldiethoxoamine hexaisopropoxide complex was isolated from reactions of N-methyldiethanolamine with Ti(OPri)4. X-ray crystallography identified the solid state compound as the unsymmetrical complex Ti2(μ2-(OCH2CH2)2NCH3)(μ2-OPri)(OPri)5. In solution, the time-averaged structure was shown by NMR to be symmetrical. The amine function coordinates to both titanium atoms alternately, while the isopropoxide ligands exchange to maintain equal coordination numbers on both titaniums. Variable temperature NMR demonstrates that the exchange processes slow on cooling, and a spectrum consistent with the solid-state structure is apparent at –50°C.

In December 1980 a series of moderately strong earthquakes struck the Lesser Zab region in the northeastern part of Iraq. The shocks were recorded at the Baghdad Seismological Observatory (BHD); the two largest earthquakes (events 1 and 2) had observed magnitudes of 5.2 and 5.8 Ms. These earthquakes caused observable field effects as well as resulting in variable degrees of structural damage to semi-engineered buildings within the mesoseismal area. By means of field quastionnaires the observed macroseismic intensity maps of the two largest shocks were compiled and an intensity attenuation relationship—the first of its kind in Iraq—was derived.

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Ti6O6(MDEA)6·2CH2Cl2 (MDEA = N-methyldiethoxoamine) was obtained by the controlled hydrolysis of the Ti(MDEA)2 complex and analysed by X-ray diffraction. The compound consists of a ring of six [TiO5N] octahedra, edge bridged by μ2-oxide and a μ2-alkoxide arm of the aminoalkoxide ligand.

Reaction of the sodium salt of the title ligand with corresponding metal salts yields complexes of the formulations (I) and (II).

Syntheses and spectroscopic (13C NMR) data for some new organyl‐Te ligands are described.

The title compound (VI) is prepared as shown.