Several industrial wastewater streams may contain heavy metal ions, which must be effectively removal
before the discharge or reuse of treated waters could take place. In this paper, the removal of copper( II)
by foam flotation from dilute aqueous solutions was investigated at laboratory scale. The effects of
various parameters such as pH, collector and frother concentrations, initial copper concentration, air flow
rate, hole diameter of the gas distributor, and NaCl addition were tested in a bubble column of 6 cm inside
diameter and 120 cm height. Sodium dodecylsulfate (SDS) and Hexadecyl trimethyl ammonium bromide
(HTAB) were used as anionic and cationic surfactant, respectively. Ethanol was used as frothers and the
optimal removal conditions have been established. Successful removals about (98%) and (76%) could be
achieved for copper ions with SDS and HTAB, respectively. Copper removal reached about 80% under
the optimum conditions at low pH; at high pH it became as high as 98% probably due to the contribution
from the flotation of precipitated copper. It was found that the presence of NaCl in the solution reduced
the recoveries. Adding ethanol at 1% concentration increased the removal efficiency. From the results the
rate of flotation was found to be first order.
Optical properties of Rhodamine-B thin film prepared by PLD
technique have been investigated. The absorption spectra using
1064nm and 532 nm laser wavelength of different laser pulse
energies shows that all the curves contain two bands, B band and Q
bands with two branches, Q1 and Q2 band and a small shift in the
peaks location toward the long wavelength with increasing laser
energy. FTIR patterns for Rhodamine-B powder and thin film within
shows that the identified peaks were located in the standard values
that done in the previous researches. X-ray diffraction patterns of
powder and prepared Rhodamine-B thin film was display that the
powder has polycrystalline of tetragonal structure, while the thin film
Background: Sliding mechanics is widely used during orthodontic treatment. One of the disadvantages of this mechanics is the friction generated at the bracket/archwire interface, which may reduce the amount of desired orthodontic movement obtained. The aim of the present in vitro study was to evaluate and compare the static frictional forces produced by two passive self-ligating brackets stainless-steel and hybrid and two conventional brackets stainless-steel and monocrystal ligated with stainless-steel ligature wire at two degrees of torque(zero and twenty) under dry condition. Materials and method: One hundred and sixty brackets were used in this study divided into four groups each group consisted of forty brackets these are: Two self-li
... Show MorePumping a BBO crystal by a violet diode laser with a wavelength of (405 nm) output power of (24 mW) and a line width of (3nm) was employed to generate entangled photons with a wavelength of 810 nm by achieving type II phase matching conditions.The coincidence count rate obtained in this experiment was in the range of (18000) counts/s. Two BBO crystals with different thicknesses of (4 mm and 2 mm) were tested, where maximum count rates of about (18000) counts/s was obtained with a (5*5*2) mm BBO crystal where the short coherence time for the pumping source was tolerated by using shorter BBO crystals. Also, the effect of compensating crystal on the walk-off effect was studied. The coincidence count rates were increased by using these crystal
... Show MoreThis is prospective study began in Jan. 2003 and concluded in April 2004, was undertaken to examine the benefits of 810 nm diode laser in treatment of four patient with bilateral vocal cord paralysis also to compare the results with conventional treatment Material and methods: 810 nm diode laser 15 watts was used in these cases under general anesthesia, and induction of anesthetic drug done through tracheostomy tube in all patients. All patients were decanulated “Tracheostomy tube removed”, the voice of all preserved within normal. Laser surgery in this case has more benefit and advantage than conventional methods even if the patient need more than on session of laser operation because of high success rate, less complication and easy
... Show MorePsychosocial Alienation is a modern concept that arises from the capitalist and materialistic conceptions of individuals. The evergrowing competitive nature of domestic societies crystallised the concept in its modern form. The intensity of the rapid changes in the urbanised societies prevents the individuals from exploring their inner selves. Thus, a new generation is created with an alienation crisis which is reflected inward towards the self and outwards toward society. Alan Ayckbourn (1939), A British playwright, presents Alienated characters inspired by his life on and off stage. He explores their Alienation and their path toward recovery and self-realization. A Brief History of Women (2017) Ayckbourn explores the depth of the individu
... Show MoreThe Sliding Mode Control (SMC) has been among powerful control techniques increasingly. Much attention is paid to both theoretical and practical aspects of disciplines due to their distinctive characteristics such as insensitivity to bounded matched uncertainties, reduction of the order of sliding equations of motion, decoupling mechanical systems design. In the current study, two-link robot performance in the Classical SMC is enhanced via Adaptive Sliding Mode Controller (ASMC) despite uncertainty, external disturbance, and coulomb friction. The key idea is abstracted as follows: switching gains are depressed to the low allowable values, resulting in decreased chattering motion and control's efforts of the two-link robo
... Show MoreThis research deals with the effects of welding variables using MIG/MAG spot by using Argon (Ar) gas and CO2 to show their effect on the mechanical characteristics and microstructure of low alloy steel type DIN15Mo3 and determine the optimum condition for the process of welding ; current & time. The results show the possibility of using CO2 and also Ar in low alloy steel welding with a little decrease in the shear force of not more than 13% for 4mm thickness and time 2sec. The shear force increased when using Ar instead of CO2 to be , The shear force reach 36KN when using Ar at 2mm thickness time of 8 sec and current of 220 Amp. , when used CO2 instead of Ar d
... Show MoreThe change in project cost, or cost growth, occurs from many factors, some of which are related to soil problem conditions that may occurs during construction and/or during site investigation period. This paper described a new soil improvement method with a minimum cost solution by using polymer fiber materials having a length of (3 cm) in both directions and (2.5 mm) in thickness, distributed in uniform medium dense .
sandy soil at different depths (B, 1.5B and 2B) below the footings. Three square footings has been used (5,7.5 and 10 cm) to carry the above investigation by using lever arm loading system design for such purposes.
These fibers were distributed from depth of (0.1B) below the footing base down to the investigated dep
We studied at the morphology, structural setup, and optical characteristics of thin cadmium (CdSe) films a thickness of 250 nm that were created by thermal evaporation over glass, The films exhibited a hexagonal shape were crystalline, and tended to form grains in the (111) crystallographic direction, according to the X-ray diffraction examinations. These characteristics were established using the investigation's findings. Through the use of thin films of CdSe doped with Ag at a concentration of 1.5%, the crystal structure orientations for pure CdSe (25.32, 41.84) and CdSe:Ag (25.39, 41.01) that were both pure as well as those that were doped with silver were both determined. The band gap of the optical spectrum decreased by 1.93–
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