In this study, the kinetics for the reaction of tert-butanol esterification with acetic acid in the presence of Dowex 50Wx8 catalyst was investigated. The reaction kinetic experiments were conducted in 1000 milliliter vessel at temperatures ranged from 50 - 80 oC, catalyst loading 25-50 g/L, and the molar ratios of acetic acid to tert-butanol from 1/3 – 3/1. The reaction rate was found to increase with increasing temperature and catalyst loading. It was also found the conversion of the tert-butanol increases as the molar ratio of acid to alcohol increases from 1/3 – 3/1. The Non-ideality of the liquid phase was taken into account by using activities instead of molar fractions. The activity coefficients were calculated according to th

 Let  be a connected graph with vertices set  and edges set . The ordinary distance between any two vertices of  is a mapping  from  into a nonnegative integer number such that  is the length of a shortest  path. The maximum distance between two subsets  and  of   is the maximum distance between any two vertices  and  such that  belong to  and  belong to . In this paper, we take a special case of maximum distance when  consists of one vertex and  consists of  vertices, . This distance is defined by: where  is the order of  a graph .

     In this paper, we defined  – polynomials based on

The research aims at:

1. Identifying the problems facing kindergarten teachers.
2. Identifying the nature of the problems facing kindergarten teachers.

To achieve the aim of the research, the researcher prepared a questionnaire to identify the problems that face the teachers of kindergartens. The questionnaire was subjected to the consultation of a group of specialized expertise in the educational and psychological sciences to certify the propriety of the items of the questionnaire and it gained a rate of (80%), and the stability of the scale gained (0.91) and it stands for a correlation parameter with a statistical significance and it was calculated by using Person’s R Corre

Background:

بحث لمعرفة رواة السنن والمسانيد للحافظ ابن نقطة

International attention to the fight against the financing of terrorism has been one of the most important systemic transformations of the modern international strategy for the prevention of the crime of terrorism. International attention to the financing of terrorism has gone through multiple periods، considering that funding has not been a priority for the international community. Which led the international community to notice that there are tools that assist terrorists, the most important of which is the financial instrument, namely finance. This has led the Security Council، the General Assembly of the United Nations and regional organizations to issue binding decisions and to develop international conventions that would And to ma

The research aims to identify the level of Agentic thinking among a sample of male and female undergraduate students for both disciplines (scientific, and humanities). The researcher targeted the third and fourth stages for the academic year

(2021-2022). The study sample is (382) male and female students who were selected randomly from the University of Baghdad. To achieve the above-mentioned study aims. The researcher has developed a scale of Agentic thinking consisting of (25) items distributed over three domains. The results showed that the study sample has a high level of Agentic thinking. There are significant differences in agentive thinking in terms of gender in favor of females. There are no statistically significant diff

Unsaturated polyester toughened Epoxy was developed. Epoxy resin had toughened by weight fraction of 10, 20, 30, and 40 wt. % unsaturated polyester. FTIR spectroscopy has been used to investigating the intermolecular hydrogen bonding. Unsaturated polyester–epoxy matrices were characterized for their thermal properties. The FTIR test detected a peak shift of the functional groups which can explain cross-linking occurs between the two resins. The crosslinking between epoxy and unsaturated polyester confirmed via the existence of the stretching asymmetrical C-C band and contraction of the  C-O band. The DSC test demonstrated that glass transition temperature value decreases with epoxy strengthening. The specific heat capacity and the

The ion tail temperature of the comet ISON was calculated by using magneto-hydrodynamic MHD laws. From these equations the focus is concentrating on determine the ion tail temperature from the relations of dynamic and static pressures results.MHD equations are numerically solved using Matlab simulation code using cubic volume element method, based on three dimensionl Cartesian coordinates that devided into equal 15x15x15 equally spaced mesh. The simulation was performed using 3-D Lax explicit method considering normalised physical propreties relative to those of the solar wind at 1 AU. The results explained that it is possible to deduce two types of temperature, the first being the isotropic temperature which is shown to vary slowly with