Makale Koleksiyonu

Molecular structure and vibrational spectra of N-mesylhydroxylamin and N-mesyl-0-methylhydroxylamin by density functional theory and ab initio Hartree-Fock calculations

2005-01-01T00:00:00Z

Molecular structure and vibrational spectra of N-mesylhydroxylamin and N-mesyl-0-methylhydroxylamin by density functional theory and ab initio Hartree-Fock calculations Atalay, Yusuf; Avcı, Davut; Başoğlu, Adil; Öztürk, Ali The molecular geometry and vibrational frequencies of N-mesylhydroxylamin (N-MHN) and N-mesyl-O-methylhydroxylamin (N-MMHN) in the ground state have been calculated using the Hartree-Fock and density functional method (B3LYP) with 6-31G(d) basis set. The optimized geometric band lengths and bond angles obtained by using HF and DFT (B3LYP) show the best agreement with the experimental data. Comparison of the observed fundamental vibrational frequencies of N-MHN and N-MMHN and calculated results by density functional B3LYP and Hartree-Fock methods indicate that B3LYP is superior to the scaled Hartree-Fock approach for molecular vibrational problems. (c) 2005 Elsevier B.V. All rights reserved.

The Socio-Economic Problems of The Nagorno Karabakh Emigrants

2009-01-01T00:00:00Z

The Socio-Economic Problems of The Nagorno Karabakh Emigrants Özkul, Osman The aim of this research is to analyze the socio-economic problems of the Nagorno Karabakh community after they became refugees by being coerced into emigration. The topic of the research is the problem of "asylum-seeking" and "forced emigration", which started at the end of the 1980s. This paper first gives an account of the forced emigrations which occurred in the 19th century in order to provide a general framework of the topic. That is why the discussion begins with the refugee problem in Azerbaijan and focuses on and analyzes the effects of the problem on socio-economic life from a historical viewpoint. The paper then attempts to explain how the plans concerning the estrangement of Azerbaijanis from their national identity and the apportionment of Azerbaijani territory were systematized through the Armenian question.

Investigation of critical bus values in electric power system using simulated annealing and Tabu search algorithms

2010-01-01T00:00:00Z

Investigation of critical bus values in electric power system using simulated annealing and Tabu search algorithms Yalçın, Mehmet Ali; Öztürk, Ali The critical values of a power system are the limit values of voltage stability. These are: the values of the highest active power that load busses can take and the values of voltage amplitude and angle of the busses in this condition. In this research, the critical values in electric power systems are defined with Simulated Annealing (SA) and Tabu Search (TS) algorithms. These algorithms are known as heuristic techniques in the literature. The research is executed on a sample of 6-bus power system. At first, as the load value in a selected load bus increased step by step, load flow is executed anytime. This process was kept until an unsolvable condition was reached, so critical bus values which are limited values of voltage stability were obtained. Secondly, using (SA) and (TS) algorithms, without increasing the load on selected bus step by step, the critical value was reached directly. It was seen that the critical bus values can be obtained easier through (SA) and (TS) which are heuristic techniques.

The role of n-butyl-2-cyanoacrylate in the repair of traumatic diaphragmatic injuries

2015-01-01T00:00:00Z

The role of n-butyl-2-cyanoacrylate in the repair of traumatic diaphragmatic injuries Gurhan Bas; Orhan Veli Ozkan; Orhan Alimoglu; Ramazan Eryilmaz; Şahin, Mehmet Murat; Ismail Okan; Ugur Cevikbas Diaphragmatic injuries either by blunt or penetrating trauma require prompt surgical intervention and are often exigent to repair. N-butyl-2-cyanoacrylate (n-butyl-2-CA) is a tissue adhesive which has gained wide application in many areas of surgery including emergency. To repair the extensive injuries of the diaphragm it may be necessary the use of synthetic mesh by fixing it with sutures or staples. The use of tissue adhesives may circumvent the potential problems associated with mesh fixation. This study aimed to evaluate the efficacy and safety of tissue adhesives usage for mesh fixation in diaphragmatic injury repair. Twenty-four rats were divided into 3 groups each of them containing 8 rats. A 1- cm diaphragmatic defect was created in all rats. The defect was repaired by polypropylene suture in Group I, by mesh fixed with sutures in group II and by mesh fixed with n-butyl-2-CA in group III. The rats were sacrificed after 1 month. The episode of hernia and the adhesions were assessed by adhesion density score. Also, the abscess and inflammation in the repaired tissue were evaluated microscopically. The Kruskal-Wallis test was performed for the histopathological analysis. No diaphragmatic hernia was detected in any group. While Group III had higher adhesion density scores than group I (P: 0.027), there were no differences between group III and II (P: 0.317) and group II and I (P = 0.095) regarding adhesion density scores. The inflammation grade was higher in group III than group I and II (P < 0.001) and was higher in group II than group I (P < 0.05). There was no differences between each groups, concerning microabcsess formation (P > 0.05). Repair of traumatic diaphragmatic injury in penetrating wound, with polypropylene mesh fixed by n-butyl-2-CA in rats appears to be as efficacious and safe as conventional methods in early period. However, further experimental and clinical study are needed to compare the long-term results of adhesive mesh repair with those of the traditional sutured techniques.