Incorporation of waste glass and bottom ash in concrete construction

This research investigated the effect of incorporating waste glass powder and raw bottom ash in concrete construction. Laboratory work was designed to identify the performance of concrete mixes using waste glass powder and raw bottom-ash as a partial substitute of cement. The performance of the prepared mixes was obtained in terms of workability, compressive strength. The first series of concrete mixes were prepared with 10%, 20% and 30% glass powder as a replacement of the cement content. The cement content of the second series were replaced with 10%, 15% and 20% raw bottom-ash. Further, a third series were carried out having 20% of cement content replaced by 10% of glass powder and 10% of raw bottom ash

Effect of forta-ferro fibers on fresh and mechanical properties of ultra high performance self compacting concrete

This research presents an experimental study of the effect of polypropylene fiber on Ultra High Performance Self Compacting Concrete (UHPSCC). Local available materials and inclusion of polypropylene fiber with different quantities are investigated to produce UHPSCC. The experimental program comprises investigating four different quantities of polypropylene fiber namely; 4.55, 9.1, 13.65 and 18.2 kg/m3. The current study focuses on the influence of polypropylene fiber on both fresh and hardened properties such as flowability, filling ability, passing ability, compressive strength, splitting strength and flexural strength of UHPSCC. The results revealed that addition of polypropylene fibers improves the compressive strength of UHPSCC in the range of 1% to 7% compared with the non-fibrous UHPSCC. They also enhance the tensile strength in the range of 20% to 30%, and improve the flexural strength within the range of 16% to 26%. Moreover, it is concluded that the optimum polypropylene fiber is 13.65 kg/m3 of concrete with splitting tensile strength of 8MPa and flexural strength of 10MPa

Mechanical Properties of RC Beams with Polypropylene Fibers under High Temperature

The objective of this study is to examine the impact of polypropylene fibers on fire resistance of steel reinforced concrete beams. In order to achieve this, concrete mixtures are prepared by using different contents of polypropylene; 0, 0.45 and 0.67 kg/m3. Simply supported beams are heated in an electric furnace to a temperature of 400 for exposure up to 4.5 hours and tested under a static point load on a universal loading frame. Based on the results of this study, it is concluded that the ultimate residual strengths of RC beams containing polypropylene fibers are higher than those without polypropylene fibers. Furthermore, the researchers find out that RC beams which are prepared using 0.67 kg/m3 of polypropylene fibers can significantly promote the residual ultimate strengths during heating

Evaluation of the stiffness of beam and frame elements using system identification techniques

Traditional methods of~ tructural analysis begin usually by the construction of a mathematical model that best represents the prototype structure. Furthermore, the material and geometric properties of the structure appear in the what is known to be either the stiffness matrix or the flexibility matrix, depending on whether the displacement or the force method is used. The subsequent analysis, ie the determination of the response of the system due to any set of loading condition hinges on the availability of such matrices. However, in situations where such information is absent or cannot be accurately computed, the analysis resorts to approximations which undoubtedly lead to erroneous results or to inaccurate ones at best. This is the case with ageing structures that have been in use for long periods of time or when the construction materials have greatly deteriorated. System identification is a method to improve mathematical modelling. Amethod which overcomes the difficulty resulting from the unknown material and geometric properties through a minimization algorithm is known to some applied science disciplines but not widely known to structural engineers. Helou (1)(2) made his presentation limeted to determinate and indeterminate trusses. The present study is an application of the same principles to beam and framed structures, thus the validity of the derived equations would be established and made general to include any structures. 26

Influence of Several Nano Minerals on The Mechanical Properties of Fresh and hardened Concrete

The current study aims at obtaining the influence of adding several nano-minerals on the mechanical properties of fresh and hardened concrete. Four types of Nano minerals were investigated in this work; namely: Brown Iron Oxide, Barium Sulfate, Titanium Dioxide and Poly Acrylic Acid. Five contents of each nano-minerals were studied. A range of contents starting from 0.5% to 2.5% with an increment of 0.5% by cement content of Brown Iron Oxide and Barium Sulfate was investigated. The Titanium Dioxide and Poly Acrylic Acid were added to concrete in percentages of 1% to 5% with an increment of 1% by cement content. Adding 5% Poly Acrylic Acid to the other three nano-minerals at selected contents separately was also studied. The measured mechanical properties of concrete comprised slump value, 7 and 28 days compressive strength. Some of the results revealed that there was 24% increase in the slump value corresponding to every 1% increase in PAA content. An improvement of 6.9% in the 28 days compressive strength was measured at every 0.5% increase of Brown Iron Oxide. It was also found that by adding 5% Poly Acrylic Acid and 2.5% Brown Iron Oxide to the concrete at the same time, the slump increased from 90 mm to 170 mm (88.9% increase) and the 28 days compressive strength improved from 37.37 kg/cm2 to 49.35 kg/cm2 (32.1% increase)

Percutaneous drainage of delayed post-cardiac surgery pericardial effusion

Background: Pericardial effusion and tamponade are common following valve surgery. The optimal treatment of symptomatic pericardial effusions remains controversial. The objective of this study was to present our experience in non-surgical management of delayed postoperative pericardial effusion. Methods: This retrospective study was conducted on 64 patients who had delayed pericardial effusion after cardiac surgery from 2016 to 2020. Eight patients were excluded due to the presence of inaccessible posterior or clotted pericardial effusion and were managed surgically, and 56 patients had percutaneous drainage of the pericardial fluid and were included in the analysis. Results: The mean age was 46.84±11.67 years (range: 22- 68 years), and 46.43% were females. The patients had coronary artery bypass grafting (n= 9), Aortic valve replacements  (n= 13), Mitral valve surgery (n= 21), double valve replacements (n= 8) and  combined procedures (n= 5).  All patients complained of varying degrees of exertional dyspnea. There were statistically significant differences between INR in different cardiac surgeries. Mean INR following mitral valve replacement (4.72±0.63) was significantly higher than in aortic valve replacement patients (3.32±0.34; p<0.001) and aortic valve patients (1.76±0.24; p<0.001). Fifteen patients (26.78%) had a large pericardial effusion. Successful drainage was achieved in all cases. Complications were pneumothorax (n= 2, 3.57%), recurrent effusions (n= 4, 7.14%), arrhythmias (n= 7, 12.5%), myocardial punctures (n= 2, 3.57%) and no mortality was reported. Conclusions: percutaneous drainage of postoperative pericardial effusion under radiological guidance is generally safe. Pericardial effusion is common after mitral valve surgery, which could be related to higher INR in these patients

Primary torsion of the greater omentum: An overlooked cause of acute abdomen

Background/purpose Primary torsion of the greater omentum is an uncommon cause of acute abdomen in children. It was estimated to be found in 0.1% of cases operated for acute appendicitis and is almost impossible to be diagnosed preoperatively. Surgical excision of the infarcted omentum is the treatment of choice. In this study, we aimed to highlight the importance of suspecting primary omental torsion when operating upon a child presenting with a picture of acute appendicitis with normal appearing appendix intraoperatively.Patients and methods Through the period from June 2009 to May 2016, medical records of patients who had definite diagnosis of primary omental torsion were retrospectively reviewed. Clinical presentations, laboratory findings, imaging studies results, intraoperative findings, and histopathological findings were reviewed.Results During the specified time period, out of 1344 patients operated upon for acute appendicitis in our department, only four patients proved to have primary torsion of the greater omentum. All the patients were obese with clinical picture mimicking acute appendicitis. The postoperative histopathological examination showed normal appendix and ischemic necrosis of the resected omental segment.Conclusion Inspection of the greater omentum is essential when finding a normal appearing appendix in any case operated for suspicion of acute appendicitis. Keywords: acute abdomen, appendix, greater omentum, omental torsio

AN EXPERIMENTAL SOCIOLINGUISTIC STUDY OF LANGUAGE VARIATION IN JORDANIAN ARABIC

The use of instrumental techniques in studies on the correlation of social variables with consonantal variation is a new trend in linguistic research. This trend is part of a new eclectic research area called socio-phonetics. This technique, to our knowledge, has not been so far utilized in investigating the phonological variations in Arabic. Therefore, the purpose of this study is to examine the social impact of gender and educational setting on patterns of variation in the use of /θ/, / dʒ /and /ð/ by means of instrumental as well as auditory techniques. A pictorial interview was used to elicit data from the speech of 40 male and female respondents from two educational backgrounds. The main results of the study indicate that gender and educational setting differences affect the use of linguistic variants. Auditory examination reveals that men and individuals with high school education have a higher tendency to maintain the use of local variants, whereas women and individuals with university education have a higher tendency to adopt non-local prestigious variants. Furthermore, employment of acoustic measurements uncovered that in the use of local variants female respondents tend to consciously lower the degree of salience of these variants. In conclusion, male and female speech behavior depends on social priority. Men are driven by the concept of masculinity and toughness, while women are driven by prestige and softness

Ultrastructure of the anterior adhesive apparatus of the gill parasite Macrogyrodactylus clarii and skin parasite M. congolensis (Monogenea; Gyrodactylidae) from the catfish Clarias gariepinus

Transmission electron microscopy (TEM) was used for the first time to study the anterior adhesive apparatus of the monogeneans Macrogyrodactylus clarii Gussev, 1961 and M. congolensis (Prudhoe, 1957) Yamaguti, 1963 inhabiting gills and skin respectively of the same catfish Clarias gariepinus. Despite the different microhabitats occupied by these parasites, the present study revealed that they have a similar anterior adhesive system. In both parasites, the anterior adhesive apparatus consists of three types of gland cells: G1 cells that produce rod-shaped bodies (S1), G2 cells manufacture irregularly shaped bodies (S2) and G3 cells form mucoid-like secretions (S3). In the cytoplasm of G1 cells, a single layer of microtubules encloses each developing rod-shaped body. A unique feature of S1 secretory bodies is that some fully developed S1 bodies are attached to each other, forming large condensed globules in the cytoplasm of G1 gland cells and terminal portion of the G1 ducts, but none were detected in the adhesive sacs outside the ducts. In the adhesive sacs, G1 ducts open with multiple apertures whereas each of the G2 and G3 ducts have a single opening. The adhesive sacs are lined with two types of tegument (st1 and st2). A third tegument type (st3) connects the st2 tegument with the general body tegument. Only st1 has microvilli. Each adhesive sac is provided with a spike-like sensillum and single uniciliated sense organ. The possible functions of microvilli in increasing the surface area and assistance in spreading and mixing of the adhesive secretion, and the role of sense organs associated with the adhesive sacs are discussed

Repairing and Strengthening of Damaged RC Columns Using Thin Concrete Jacketing

This research aims to investigate the efficiency of repairing damaged concrete columns using thin concrete jacketing. The experimental program included casting of nine reference 300 mm long reinforced concrete column specimens: three specimens had a cross-sectional dimension of 100 mm × 100 mm, three specimens had a cross-sectional dimension of 150 mm × 150 mm, and three specimens had a cross-sectional dimension of 170 mm × 170 mm. A total of 36 identical column cores were cast with similar cross sections of 100 mm × 100 mm and a height of 300 mm. These cores were damaged by loading them with approximately 90% of their actual ultimate axial load capacities. Then, the columns were repaired and strengthened by applying two jacketing materials, which were 25 and 35 mm thick, on all four sides. Group 1 consisted of 18 column cores jacketed by normal strength concrete with a maximum aggregate size of 4.75 mm and steel reinforcement, whereas Group 2 consisted of 18 column cores jacketed using ultrahigh-performance fibre-reinforced self-compacting concrete with steel reinforcement. The experimental program showed that the Group 1 specimens had ultimate load capacities more than twice those of the unjacketed reference columns and the same axial capacity as the monolithically cast reference columns. The Group 2 specimens showed a significant increase in ultimate load capacity, which was approximately 3 times that of the unjacketed reference column and 1.86 times that of the monolithically cast reference columns. Moreover, using the shear studs was found to be the most effective …This research aims to investigate the efficiency of repairing damaged concrete columns using thin concrete jacketing. The experimental program included casting of nine reference 300 mm long reinforced concrete column specimens: three specimens had a cross-sectional dimension of 100 mm × 100 mm, three specimens had a cross-sectional dimension of 150 mm × 150 mm, and three specimens had a cross-sectional dimension of 170 mm × 170 mm. A total of 36 identical column cores were cast with similar cross sections of 100 mm × 100 mm and a height of 300 mm. These cores were damaged by loading them with approximately 90% of their actual ultimate axial load capacities. Then, the columns were repaired and strengthened by applying two jacketing materials, which were 25 and 35 mm thick, on all four sides. Group 1 consisted of 18 column cores jacketed by normal strength concrete with a maximum aggregate size of 4.75 mm and steel reinforcement, whereas Group 2 consisted of 18 column cores jacketed using ultrahigh-performance fibre-reinforced self-compacting concrete with steel reinforcement. The experimental program showed that the Group 1 specimens had ultimate load capacities more than twice those of the unjacketed reference columns and the same axial capacity as the monolithically cast reference columns. The Group 2 specimens showed a significant increase in ultimate load capacity, which was approximately 3 times that of the unjacketed reference column and 1.86 times that of the monolithically cast reference columns. Moreover, using the shear studs was found to be the most effective