Rock engineers widely use the uniaxial compressive strength (UCS) of rocks in designing
surface and underground structures. The procedure for measuring this rock strength has been
standardized by both the International Society for Rock Mechanics (ISRM) and American Society
for Testing and Materials (ASTM), Akram and Bakar(2007).
In this paper, an experimental study was performed to correlate of Point Load Index ( Is(50))
and Pulse Wave Velocity (Vp) to the Unconfined Compressive Strength (UCS) of Rocks. The effect
of several parameters was studied. Point load test, Unconfined Compressive Strength (UCS) and
Pulse Wave Velocity (Vp) were used for testing several rock samples with different diameters.
The predicted empirical correlations based on various test results indicate that the UCS could be
obtained directly from measured (Vp), and then the Index Is(50) can be calculated by back
substitution.
The species of Cr (III), Cr (VI) in biological samples and V(IV), V(V) in foods & plants samples were determined by spectrophotometric methods. Integrated spectral studies of complexes [Cr (III, VI)-DPC], [Cr (VI)-bipy], [VO-SH], [V (V)-8-HQ] which included a study of the optimum conditions for the complexes formation by the investigation of the chemical and physical variables affecting each complex formation, the nature of complexes, the preparation of calibration curves of the complexes and treated the resulted data by modern statistical methods and study the interfering species. Interferences were removed to explain the reactions thermodynamically by determining Ecell, Keq. and ∆G values and includes a study of
... Show MoreChelating agents were used in a chelation therapy to detoxify heavy metals and toxins and convert them to an inactive form which was excreted out of the body. Nickel is one of these toxic heavy metal when presented in a high values over its allowable limit. This work studies the complexation of some amino acid (Glycine, Histidine, and Arginine) with nickel (II) ion and compare the result with complexation of EDTA (the synthesized amino acid) used in the chelation therapy. Our experiment were performed in a phosphate buffer of PH (7.2) and in a different temperature (283, 288,293, 298, 303)K . The results show a high tendency for these amino acid to nickel ion with an equilibrium constant in arrange of [KNi(II)-EDTA(17.2×108) > KNi(II
... Show MoreFUZZY CONTROLLERS F'OR SINGLE POINT CONTROLLER-I (SPC-l) SYSTEMS
This study was conducted to investigate the effects of Al-Rasheed power plant (RPP) effluents at Al-Zafaraniya city on the physical – chemical of the Tigris River by using Canadian Water Quality Index(CCME WQI).Water samples were taken monthly at four positions and 11parameters were analyzed . The results of this study conducted that there was a significant impact of the RPP effluents on increase of water temperature, turbidity and electrical conductivity, and there was an increase in the phosphate concentration and water hardness at station 2 and the model classified water of Tigris river as poor in winter and fair to marginal in rest season for drinking and aquatic life
ABSTRACT Background:Hydrogen absorption and related degradation in the mechanical properties of Ni-Ti based orthodontic wires has been demonstrated following exposure to fluoride prophylactic agents. This study was designed to investigate the effects of three fluoride containing agents on the load deflection characteristics of heat activated nickel titanium arch wires during unloading phase. Material and method: Eighty specimens of heat activated nickel titanium arch wires were obtained from Ortho Technology Company, half of which had a 0.016 inch round and 0.019x0.025 rectangular. Ten specimens from both wire size were immersed in one of the tested fluoride prophylactic agents (neutral sodium fluoride gel, stannous fluoride gel or phos-flu
... Show MoreIn this study two types of extraction solvents were used to extract the undesirable polyaromatics, the first solvent was furfural which was used today in the Iraqi refineries and the second was NMP (N-methyl-2-pyrrolidone).
The studied effecting variables of extraction are extraction temperature ranged from 70 to 110°C and solvent to oil ratio in the range from 1:1 to 4:1.
The results of this investigation show that the viscosity index of mixed-medium lubricating oil fraction increases with increasing extraction temperature and reaches 107.82 for NMP extraction at extraction temperature 110°C and solvent to oil ratio 4:1, while the viscosity index reaches to 101 for furfural extraction at the same extraction temperature and same