Background: The Streptococcus genus are the predominant bacteria in the mouth and the Streptococcus sanguinis is one of them which performing a primary function for expansion of dental biofilm. Gingival and periodontal disorders are caused by dental biofilm, today, there is a necessity to discover naturally presenting antibacterial compounds from herbs with less side effects as a substitutive to the commonly handled chlorohexidine. Thus, the purpose of this study was to assess the antibacterial activity of thymus vulgaris oil on Streptococcus sanguinis bacteria In vitro. Materials and Methods: Human supragingival plaque samples were taken from 10 subjects, then morphological and microscopical examination, biochemical tests, Optochin test, hemolytic ability test and conventional polymerase chain reaction test was applied to assure coincidence of Streptococcus sanguinis. The sensitivity of bacteria to Thymus vulgaris oil, the minimum concentration that inhibit the growth and killed the test bacteria were identified a partly as comparable to 0.2% chlorhexidine as a positive control and10 % dimethyl sulphoxide as a negative control. Results: Thymus vulgaris oil presented a significant antibacterial property on Streptococcus sanguinis with several grades of inhibition zones. When compared to Chlorohexidine, Thymus vulgaris oil had stronger antibacterial properties. The minimum concentration that inhibited the growth and killed Streptococcus sanguinis was (0.09%). Conclusion: Thymus vulgaris oil displayed higher antibacterial action with each concentration on Streptococcus sanguinis as compared to Chlorohexidine, therefore; it can be used as a natural substitutive oral health care product to Chlorohexidine.
The time spent in drilling ahead is usually a significant portion of total well cost. Drilling is an expensive operation including the cost of equipment and material used during the penetration of rock plus crew efforts in order to finish the well without serious problems. Knowing the rate of penetration should help in speculation of the cost and lead to optimize drilling outgoings. Ten wells in the Nasiriya oil field have been selected based on the availability of the data. Dynamic elastic properties of Mishrif formation in the selected wells were determined by using Interactive Petrophysics (IP V3.5) software based on the las files and log record provided. The average rate of penetration and average dynamic elastic propert
... Show MoreThe current research illustrates experimentally the effect of series and parallel connection (Z-I Configurations) of flat plate water solar collectors array on the thermal performance of closed loop solar heating system. The study includes the effect of changing the water flow rate on the thermal efficiency. The results show that, the collector's efficiency in series connection is higher than the parallel connection within flow rate level less than (100) ℓ/hr. Moreover, the collector efficiency in parallel connection of (I-Configurations) is more than the (Z- Configurations) with increasing the water flow rate .The maximum daily efficiency for parallel (I-Configurations) and (Z- Configurations) are (55%) and (51%) at w
... Show MoreThis work is concerned with a two stages four beds adsorption chiller utilizing activated carbon-methanol adsorption pair that operates on six separated processes. The four beds that act as thermal compressors are powered by a low grade thermal energy in the form of hot water at a temperature range of 65 to 83 °C. As well as, the water pumps and control cycle consume insignificant electrical power. This adsorption chiller consists of three water cycles. The first water cycle is the driven hot water cycle. The second cycle is the cold water cycle to cool the carbon, which adsorbs the methanol. Finally, the chilled water cycle that is used to overcome the building load. The theoretical results showed that average cycle cooling power
... Show MoreSuffer most of the industrial sector companies from high Kperfi magnitude of the costs of industrial indirect, lack of equitable distribution of these costs on the objectives of cost, increased competition, and the lack of proper planning in line and changes faced by the industrial sector (general) and sample (private), as well as the difficulty in re- directing efforts to improve profitability and in-depth analysis of activities, and to identify untapped resource activities, then link these activities to the final products The research aims to apply the technology review and evaluate programs with the method (ABC) through the application stages of planning, scheduling and control and a comparison to get to the products of dev
... Show MoreAbstract
The research aims at the relationship between Servant leadership dimensions test as an independent variable and an organizational trust as a variable dependent. Thus it was necessary to answer the following question: Is there a correlation relationship and impact between Servant leadership dimensions and organizational trust? To investigate the contents of the answer, the researcher selected a group of employees in Oil Products Distribution Company / Baghdad. The researcher adopted the analytical descriptive approach in completing his research which dealt with a random sample of (190) individuals representing the research society out of the total number of (376) person from the middle and high Leaders. Depending
... Show MoreThe fluctuations in oil prices in world markets affect the general budget and the trade balance of the rent countries, because oil is a strategic commodity affected by economic and political factors. The fluctuations in oil prices affect the public budgets of the rent countries through the public revenue side of oil revenues. On the other hand, these fluctuations affect the balance of trade through the volume of oil exports, which lead to imbalance of trade surplus or deficit . &nbs
... Show MoreThis study was conducted with the aim to extract and purify a polyphenolic compound “ Resveratrol†from the skin of black grapes Vitis vinifera cultivated in Iraq. The purified resveratrol is obtained after ethanolic extraction with 80% v/v solution for fresh grape skin, followed by acid hydrolysis with 10% HCl solution then the aglycon moiety was taken with organic solvent
( chloroform). Using silica gel G60 packed glass column chromatography with mobile phase benzene: methanol: acetic acid 20:4:1 a
... Show MoreAn investigation was conducted for the improvement of viscosity index of light lubricating oil fraction (40 stock)
obtained from vacuum distillation unit of lube oil plant of Daura Refinery, using solvent extraction process.
In this study furfural solvent was used to extract the undesirable materials which reduce the viscosity index of raw
lubricating oil fraction.
The studied effecting variables of extraction were extraction temperature range from 70 to 110°C, and solvent to oil
ratio range from 1:1 to 4:1 (wt/wt).
The n-d-M method was used for calculation of carbon distribution and structural group analysis of the raffinate
produced from furfural extraction.
Also the three component phase diagram for a mixed-ba