This study is concerned with the adsorption of Congo red from solution on the surface of Chaff. The adsorption isotherm is of L-curve type according to Giles classification and the experimental data were best fitted to Langmuir isotherm model. The adsorption phenomenon was examined as a function of temperature (25, 40, 55 oC). The extent of adsorption of Congo red on Chaff was found to increase with the increase of temperature (endothermic process). The basic thermodynamic functions have also been calculated. The effect of contact time was investigated and found that the adsorption process of dye on Chaff surface reached complete equilibrium within 90 min. The maximum uptake of Congo red by Chaff was found to be 92.9% at 25oC. The kinetic data were well fitted to the Lagergren, pseudo-second order models. The results indicated that adsorption process followed the second order model. This behavior was discussed depending on the chemical structure of dye and Chaff surface. The kinetics of dye adsorption was also studied in terms of intraparticle diffusion model. The results indicated that intraparticle diffusion plays a significant role in the adsorption mechanism.
In this study, the response of ten composite post-tensioned concrete beams topped by a reinforced concrete deck with adequate reinforcing shear connectors is investigated. Depending on the concrete compressive strength of the deck slab (20, 30, and 40 MPa), beams are grouped into three categories. Seven of these beams are exposed to a fire attack of 700 and 800 °C temperature simultaneously with or without the presence of a uniformly distributed sustained static loading. After cooling back to ambient temperature, these composite beams are loaded up to failure, using a force control module, by monotonic static loading in a four-point-bending setup with two symmetrical concentrated loads applied in
سعي المجتمع العراقي منذ أكثر من نصف قرن مضى لإعادة استثمار عشرات المليارات من الدولارات من الإيرادات النفطية في القطاع الزراعي وهياكله وبنياته التحية، كإنشاء السدود والخزانات المائية واستصلاح الأراضي والمشاريع الإنتاجية الحيوانية والنباتية وبطاقات كادت تقترب او تتجاوز حاجز طلب السكان من الأغذية والمنتوجات الزراعية التي تغذي الصناعة الا ان الزيادة السكانية وتحسن مستوى الدخل النفطي شكلا انتقالا جدي
... Show MoreThe research deals with the impact of the nature of social and political formation in the orientation towards extremism through tracking the institutions and beliefs that the individual is going through. The role of the family, the group, the school, education, and religion has been touched upon in acquiring the trends of extremism, whether publicly or covertly, Focusing on the social and economic contexts that are an incubator environment for extremism supported by the form of the group and the beliefs it espouses, whether direct through religion or indirectly through the nature of education, this study relied on political literature that addressed this The topic, which focused on the phenomenon of extremism that swept the world recentl
... Show MoreMusic and singing are always associated with the movement of society and the emergence of cultural and artistic activities other.
The social and political transformations of the 1930s helped to disseminate the study Music and music in the city of Baghdad and across Iraq This is the beginning of a new era of musical art alongside other arts.
While achieving musical arts A new step was advanced by publishing a technical study among the younger generation they were looking for to contribute to the musical field On the other hand, the city of Baghdad during the period of research many musical and musical performances Egyptian teams have provided many artistic activities and events which have had a significant impact on the development
Oscillation criteria are obtained for all solutions of the first-order linear delay differential equations with positive and negative coefficients where we established some sufficient conditions so that every solution of (1.1) oscillate. This paper generalized the results in [11]. Some examples are considered to illustrate our main results.
Background: Body image is one of the most important psychological factors that affects adolescents’ personality and behavior. Body image can be defined as the person’s perceptions, thoughts, and feelings about his or her body.
Objectives: to identify the prevalence of body image concerns among secondary school students and its relation to different factors.
Subjects and methods: A cross-sectional study conducted in which 796 secondary school students participated and body shape concerns was investigated using the body shape questionnaire (BSQ-34).
Results: The prevalence of moderate/marked concern was (21.6%). Moderate/ marked body shape concern was significantly associated
... Show MoreThe tremendous benefits of using cellular phones, which began to increase and unprecedented spread worldwide last decade, were accompanied by harmful effects on the environment due to the increase in electromagnetic radiation (EMR) which be emitted from mobile phone towers. This effect on humans, animals, and plants, which is considered a form of environmental pollution, was sensed by developed countries and Environmental protection organizations. These countries have established restrictions and enacted laws to reduce their negative impact on living beings. The field survey included six major hospitals and 38 schools were distributed over the central neighbourhoods in Al-Najaf city. The results showed that power density (PD) measurement
... Show MoreThere is no doubt that optical fiber technology is one of the most important stages of the communications revolution at all and it is of utmost importance in our daily life. In this work, five fibers with core radii 2.5, 4.5 and 6.5–8.5 μm were designed. The properties of all guided modes have been calculated at a wavelength of 1550 nm by using RP Fiber Calculator. A single-mode fiber is obtained when the core radius approaches the wavelength. As the core radius is increased, the fiber becomes a multimode. The percentage power in the core increases with increasing core radius. The modes profiles were illustrated and compared with the modern references.