Search

Postintubation tracheal stenosis is the most common cause of benign tracheal stenosis. Surgical treatment is more challenging in long-segment stenosis. Suprahyoid release can increase tracheal length resected without anastomotic tension in patients with post-intubation tracheal stenosis. Its effect on swallowing has not been objectively studied and this article aims to explore its virtues and potential complications in a tertiary center for airway surgery. A prospective cohort study was conducted on forty consecutive patients from June 2020 till December 2023. Patients of both genders had tracheal resection anastomosis surgery with routine suprahyoid muscle release for resected tracheal segment of more than 2.5 cm in length aiming to decrease the anastomotic tension. Within two weeks postoperatively, a video naso-laryngoscope was done on all the patients to detect any vocal cord disorders, then they were examined by video fluoroscopy swallowing study VFSS to detect swallowing problems. Follow up was done for 6 months postoperatively. 40 patients were studied. Twenty-five patients (62.5%) were males. 21 patients (52.5%) had a cricotracheal resection. VFSS was performed on 38 patients (two patients excluded for serious morbidity). Six (15.7%) and four (10.5%) patients had residual semisolid and solid food in the vallecula and pyriform fossa respectively during swallowing. Five patients (13%) out of eight patients with abnormal VFSS had aspiration and dysphagia. Video nasolaryngoscopy was done pre- and post-operatively and showed that 7 patients (17.5%) had unilateral vocal cord paralysis, two of them had the same lesion preoperatively. Two patients developed postoperative anastomotic complications. All symptoms of dysphagia improved within 3 weeks of the procedure and improvement persisted for 6 months. Suprahyoid muscle release had a considerable reversible drawback on the process of swallowing. Its routine use in high-risk patients requiring long segment tracheal resections could be considered.

The study of concrete structure strengthening utilizing various ways has recently piqued the interest of researchers. The researchers concluded that strengthening structural concrete parts such as reinforced concrete (RC) columns with a concrete and Fiber-Reinforced Polymer (FRP) jacket can result in a significant increase in the maximum failure load. The aim of this analysis was to evaluate and test the effectiveness of using concrete and FRB as a reinforcing material to reinforce the entire height of downscaled historic RC columns. One identical Group (G1) unstrengthen reference column (C1) with cross sections of 200 × 200 mm and a height of 1500 mm was used in the experiments. In addition, seven monolithically cast columns with identical cross sections of 200 × 200 mm and a height of 1500 mm were fabricated. All the columns were composed of weak concrete. In this paper, the applied strengthened styles were Group (G2), which consisted of four columns cores reinforced by entirely concrete, CFRP, GFRP, and BFRP jackets, and Group3 (G3), which consisted of three columns reinforced by partial striped FRP as a strengthening material. The failure load, failure pattern, and longitudinal axial strain of all produced column specimens were studied in this work by testing them under monotonic uniaxial compression stress. The G1, G2, and G3 specimens provided a significant considerable improvement in ultimate load failure load after strengthening by nearly 1.8 times than the reference column, according to the testing data.

Introducing1-(2-aminoethyl)-1-dodecyl-2-undecyl-4,5-dihydro-1H-imidazol-1-ium chloride (LQI), 1-(2-aminoethyl)-1-dodecyl-2-tridecyl-4,5-dihydro-1H-imidazol-1-ium chloride (MQI) as two organic structures quaternary ammonium salts, which have been made and analyzed by FTIR, 1H NMR spectroscopic methods. (X-65) carbon steel’s corrosion in naturally formed rocks’ oil wells formation water in the nonappearance (Blank) and using a wide range of concentrations (50, 100, 200, 300, 400, 500 ppm) of these cationic surfactants, as inhibition blockers using direct current (DC), alternative current (AC) electrochemical ways. To sum up, the inhibition efficiency grew with up the gradual rise in the inhibitor content till having peaked at (500 ppm) registered (94.83%) for (MQI). Specifically, carbon steel’s morphology was closely inspected with the aid of highly automated scanning electron microscopy, and energy dispersive X-ray facilities. As a matter of fact, quantum chemical calculations enriched the theoretical study of the (LQI, MQI) compounds depend on energy levels’, energy maps, and 3D structures consideration.

The column is the most important structural element were strengthening of columns became a demanding issue. In this paper, the effectiveness of strengthening reinforced concrete (R.C) columns with carbon fiber reinforced polymers (CFRP) wraps has been improved by increasing the contact area between the column’s surface area and CFRP. A new strengthening technique was hired for the purpose of enhancing the efficiency of CFRP jackets in improving the load capacity of R.C columns, especially columns with rectangular sections. The method is based on increasing the contact area between the CFRP jacket and the column's surface area. This was done by adjusting the profile of the col's cross-section to almost ellipsoidal. The experimental program in this research includes testing 13 columns to include all test parameters, the shape of the cross-section, and the cross-section profile. The results include axial stresses and corresponding axial strains, and lateral strains at the mid-height and quarter height of tested specimens. And also, the cracking load and maximum load with crack patterns are determined. The comparison involved the study of the effect of the traditional CFRP jacket wrapping of R.C columns with square, and rectangular sections and the newly developed strengthening technique. A theoretical study was also conducted. Where the capacity of the square and rectangular confined columns with different radius of curvature, R, of the ellipsoidal profile is determined by the predicted and design equations. The study revealed that the strengthening technique is expected to effectively enhance the efficiency of the CFRP strengthening technique, especially for columns with square and rectangular sections as the area of the well-known dead zone of these columns is reduced using the proposed technique. Also, the results proved that the efficiency of strengthening tested columns by CFRP jacket has been enhanced using the strengthening technique by about 80% of original RC columns, which exceeds the traditional method (Jacket) CFRP wrap by 60%.