Background: The ideal force-delivery system must: provide optimal tooth moving forces that elicit the desired effects, be comfortable and hygienic for the patient, require minimal operator manipulation and patient cooperation and provide rapid tooth movement with minimal mobility during orthodontic therapy, the elastomeric chains have the greatest potential to fulfill these requirements. Materials and Methods: This in vitro study was designed to determine the effect of three different mechanisms for canine retraction : (6-3 , 6-5-3 and chain loop ) on the load relaxation behavior of three types of elastomeric chains : (maximum clear , maximum silver and extreme silver) from the same company (Ortho Technology company) with two different bran

Aspergillus niger is one of the most important filamentous fungi that used in the fermentation industry. Aspergillus niger isolate was cultured on potato-dextrose agar (PDA) for activation, and the optimum conditions for xylanase production from this local isolate were studied by solid state fermentation, using a medium composed of wheat bran moisten with corn steep liquor at ratio 1:0.5 (v:w) at initial pH 5.5, inoc-ulated with 1.6 × 106 spores/ml, and incubated at 30ᵒC for 5 days.

Aspergillus flavus isolates which are considered on conidial shape through microscopic examination and mycelial colour through cultural properties . Primary screening for the ability of A. flavus isolates for aflatoxin production was determined using A.flavus parasiticus agar medium (AFPA) as well , 7 isolates from 11 isolates give a positive result by the presence of bright yellow-orange pigments indicated the presence of aflatoxins. Molecular genetics techniques using DNA polymorphism have been increasingly used to characterize and identify genetic diversity and relationships among eleven A. flavus isolated from different source using the ISSR(inter simple sequence repeats) technique. Three universal primers designed at University of B

The study was conducted to vaccinate chickens against coccidiosis  using alive vaccine contain seven species of chicken Eimeria,  E. tenella, E. brunetti, E. necatrix, E. maxima, E. mevati, E. acervulina  and E. praecox.    A total of 120 chicks were divided into two main groups: broiler group and egg laying group.  The birds of each group were allocated on to three pins, each contains 20 chicks.  The birds of the experiment were vaccinated at day nine of age, with a suspension of mixed Eimeria which contain 50 Oocysts of E. tenella with a different percent of other species, respectively.  The vaccine was given to chicks in the 1st pins of each group with drinking water,  the chicks in th

This paper deals with the modeling of a preventive maintenance strategy applied to a single-unit system subject to random failures.

According to this policy, the system is subjected to imperfect periodic preventive maintenance restoring it to ‘as good as new’ with probability

p and leaving it at state ‘as bad as old’ with probability q. Imperfect repairs are performed following failures occurring between consecutive

preventive maintenance actions, i.e the times between failures follow a decreasing quasi-renewal process with parameter a. Considering the

average durations of the preventive and corrective maintenance actions a

The effect of three ionic liquids viz., 1-hexyl-3-methylimidazolium tetrafluoroborate (ILE), 1-hexyl-3-metylimidazolium hexafluorophosphate (ILF) and 1-octyl-3-methylimidazolium tetrafluoroborate (ILG) when used as surfactants on the performance of dissolved air floatation (DAF) was investigated.

   Experiments were conducted at a temperature of 30-35 ºC, 10ppm ferric chloride as coagulant, 50% recycle ratio, pH 8, and 10 minutes treatment time  to find oil and grease (OG) and turbidity removal efficiencies at saturation pressure (2-6) bar.

ILs were used at concentration of 50 µl/liter of treated water in two positions in DAF system; the saturation vessel and the treatment tank. The performance using ILs

This paper describes the transport of Alkaloids through Rotating Discs Contactor (RDC) using n-decane as a liquid membrane. The transport of Pelletierine Alkaloid from a source phase through bulk liquid membrane to the receiving phase has been investigated. The general behaviour of Pertraction process indicates that% Extraction of pelletierine Alkaloid increased with increase in the number of stages and the agitation speed but high agitation speed was not favoured due to the increased risk of droplet formation during the operation. The pH of source and receiving phases were also investigated. The effect of organic solvent membrane on the extraction of Pelletierine was evaluated using ndecane, n-hexane and methyl cyclohexane. The results sho

This paper focus on study the variations of monthly tropospheric NO₂ concentrations over three Iraqi cities Baghdad (33.3° N, 44.4° E), Basrah (30.56° N, 47.8° E) and Erbil (36.3° N, 44.06° E). Monthly NO₂ retrievals from the Ozone Monitoring Instrument (OMI) onboard Aura satellite during the period from October 2004 to March 2013 have been used.  The results show a high monthly and annual NO₂ concentrations at Baghdad than Basra and Erbil may be attribute to high densely populations and a high economic activity. During the whole period, Baghdad, Basrah and Erbil were exhibited an average of NO₂ (8.1±2.5), (3.7±1.3) and (3.3±1.7) in unit 10¹⁵ molecules