An experimental of kinetics investigation of the solution free radical polymerization of isopropylacrylamide (IPAM) initiated with potassium persulfate (PPS) was conducted. The reactions were carried out at constant temperature of 60 °C in distilled water under unstirred and inert conditions. Using the well-known conversion vs. time technique, the effects of initiator and monomer concentration on the rate of polymerization (Rp) were investigated over a wide range. Under the conditions of our work, the orders 0.38 and 1.68 were found with respect to initiator and monomer, respectively. However, the rate of polymerization (Rp) is not straight forwardly corresponding monomer concentration. The value 46.11 kJ mol1 was determined as the overall activation energy of polymerization, which is not satisfactory with the value of most thermal initiated monomers. Rp for IPAM in dimethyl formamide, dimethyl sulfoxide, and distilled water using PPS as initiator at 60 oC, was checked. An increase in solvent polarity has slightly increased (Rp) value. The effect of using different concentrations of PPS 0.001, 0.002, 0.003 and 0.004 mol dm-3, on the average degree of polymerization (DPn), was also studied, based on viscosity results obtained using distilled water at 20 oC. The results revealed that an increase in the initiator concentration has an effect in lowering (DP) values.
This study expands the state of the art in studies that assess torsional retrofit of reinforced concrete (RC) multi-cell box girders with carbon fiber reinforced polymer (CFRP) strips. The torsional behavior of non-damaged and pre-damaged RC multi-cell box girder specimens externally retrofitted by CFRP strips was investigated through a series of laboratory experiments. It was found that retrofitting the pre-damaged specimens with CFRP strips increased the ultimate torsional capacity by more than 50% as compared to the un-damaged specimens subjected to equivalent retrofitting. This indicated that the retrofit has been less effective for the girder specimen that did not develop distortion beforehand as a result of pre-loading. From
... Show MoreThis study aims to determine the reasons for the increase in the frequency of sand and dust storms in the Middle East and to identify their sources and mitigate them. A set of climatic data from 60 years (1960–2022) was analyzed. Sand storms in Iraq are a silty sand mature arkose composed of 72.7% sand, 25.1% silt, and 2.19% clay; the clay fraction in dust storms constitutes 70%, with a small amount of silt (20.6%) and sand (9.4%). Dust and sand storms (%) are composed of quartz (49.2, 67.1), feldspar (4.9, 20.9), calcite (38, 5), gypsum (4.8, 0.4), dolomite (0.8, 1.0), and heavy minerals (3.2, 6.6). Increasing temperatures in Iraq, by an average of 2 °C for sixty years, have contributed to an increase in the number of dust storm
... Show MoreIn this study, NAC-capped CdTe/CdS/ZnS core/double shell QDs were synthesized in an aqueous medium to investigate their utility in distinguishing normal DNA from mutated DNA extracted from biological samples. Following the interaction between the synthesized QDs with DNA extracted from leukemia cases (represents damaged DNA) and that of healthy donors (represents undamaged DNA), differential fluorescent emission maxima and intensities were observed. It was found that damaged DNA from leukemic cells DNA-QDs conjugates at 585 nm while intact DNA (from healthy subjects) DNA–QDs conjugates at 574 nm. The obtained results from the optical analyses indicate that the prepared QDs could be utilized as probe for detecting disrupted DNA th
... Show MoreThis study aimed to identify and describe one of the bacterial feeder nematode Acrobeloides varius Kim, Kim and Park, 2017 (Rhabditida, Cephalobidae), which was isolated from soil samples that were collected from Baghdad, central of Iraq, and was classified using both morphological and molecular criteria. All specimens of A. varius were cultured, identified and described using morphometric criteria. Selected specimens (Zah. IRQ3 OR994579.1 isolate) of this species were characterized by having the body length of the male ranging from (184.94 – 221.72 μm), the body length of the female ranging (507.38 – 521.92 μm) and the body length of the juvenile ranging from (355.53 – 490.35 μm). Selected specimens of this species were m
... Show MoreThis study analyses six political cartoons selected based on their relevance to current Iraqi political issues, specifically the period between 2005 and 2015, from American online newspapers (calgecartooms.com). The selection criteria included the cartoons' satirical elements, visual rhetoric, and their ability to engage with themes such as power dynamics, social issues, and public opinion. It sheds light on how these cartoons can function as mediators of meanings between the cartoonists and the readers. The data is examined using multimodal discourse analysis (MDA), which combines language study with the analysis of other visual elements, like colors, gestures, and images, to understand meaning (O’Halloran et al., 2011). The Visual Socia
... Show MoreThe aim of this research is to know the effect of two strategies of active learning, the five fingers and traffic signals, on the first grade intermediate level student's achievement and personal intelligence. The research sample was chosen from the Al- Mansour intermediate school for boys, including (101) students divided into three groups chosen randomly which represented the first experimental group (32) students, the second experimental group (34) students, and the control group (33) students. To achieve the research aims, the research prepared a physics achievement test containing (26) items, and a personal intelligence test containing (20) items. The psychometric characteristics, of the tests were checked up the following results were
... Show More