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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Computational Applied Mechanics
- نوع مقاله: Journal Article
- کلمات کلیدی: Mathematical Modeling,Fluid coupling,Power transmission,Variable fill coupling,Turbomachinery
- چکیده:
- چکیده انگلیسی: Variable fill fluid couplings are used in the speed control units. Also, variation in coupling oil volume is used in adapting one size of coupling to a wider range of power transmission applications. Available model for the partially filled fluid couplings, has a good performance for couplings with fixed amount of oil but their performance will be degraded if they are used for the variable fill couplings. In this paper, the current model for partially filled fluid couplings is modified to have better performance for variable fill couplings. For this purpose, the circulation loss calculation is modified and also, the effect of oil temperature variations and blade thickness are included in the model. The effect of these modification on the model performance are investigated in couple of simulations. Comparing the simulation results with the available experimental data shows that the suggested modifications can improve the model performance very well.
- انتشار مقاله: 19-11-1396
- نویسندگان: Saeed Bahrami,Ali Keymasi Khalaji
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Computational Applied Mechanics
- نوع مقاله: Journal Article
- کلمات کلیدی: Mathematical Modeling,Fluid coupling,Power transmission,Variable fill coupling,Turbomachinery
- چکیده:
- چکیده انگلیسی: Variable fill fluid couplings are used in the speed control units. Also, variation in coupling oil volume is used in adapting one size of coupling to a wider range of power transmission applications. Available model for the partially filled fluid couplings, has a good performance for couplings with fixed amount of oil but their performance will be degraded if they are used for the variable fill couplings. In this paper, the current model for partially filled fluid couplings is modified to have better performance for variable fill couplings. For this purpose, the circulation loss calculation is modified and also, the effect of oil temperature variations and blade thickness are included in the model. The effect of these modification on the model performance are investigated in couple of simulations. Comparing the simulation results with the available experimental data shows that the suggested modifications can improve the model performance very well.
- انتشار مقاله: 19-11-1396
- نویسندگان: Saeed Bahrami,Ali Keymasi Khalaji
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Medicine
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده: امروزه جراحی های لاپاروسکوپی بطور گسترده ای مورد پذیرش جراحان و بیماران قرار گرفته است. دراین میان برداشت کامل طحال (اسپلنکومی) نیز که در شرایط تومور های طحال، جراحات ضربه ای، چرخش های طحال و دهندگان خون کاربرد دارد به روش لاپاروسکوپی قابل انجام به نظر می رسد. به همین منظورجهت بررسی کارایی، اطمینان و سهولت برداشت طحال به روش لاپاروسکوپی، این عمل جراحی روی مدل حیوانی سگ برای نخستین بار در ایران آزمایش شد. بدین ترتیب سه قلاده سگ نر از نژاد مخلوط پس از آماده سازی های معمول جراحی های شکمی تحت بیهوشی عمومی و در حالت خوابیده به پشت و متمایل به راست با زاویه 45 درجه نسبت به خط افق قرار گرفتند. با قرار دادن سه پورت در ناف ، 3 سانتی متر بالاتر از ناف و ناحیه خلفی-جانبی راست شکم جراحی آغاز شد. پس از ارزیابی موقعیت طحال، انتهای خلفی طحال 90 درجه به سمت جانب و چپ چرخانده شد. سپس اسپلنکتومی با قطع عروق و اتصالات طحال به وسیله الکتروکوتر دو قطبی انجام گردید. پس از جداسازی کلیه اتصالات طحال و ارزیابی پایه باقی مانده از لحاظ خونریزی، طحال در کیسه مخصوص قرار گرفته و از طریق پورت نافی خارج گردید. در نهایت محل پورتها به روش معمول بخیه شدند.میانگین مدت زمان جراحی42 دقیقه ثبت گردید. جراحی در سگها موفقیت آمیز و بدون عارضه بود. بدین ترتیب به نظر می رسد اسپلنکتومی کامل به روش لاپاروسکوپی در سگها روشی قابل انجام با ضریب اطمینان بالا و آسان می باشد.
- چکیده انگلیسی: Cases of minimally-invasive surgery are gaining acceptance among surgeons and animal owners. One type of minimally-invasive surgery is total splenectomy, which is indicated for splenic tumors, trauma, torsions, and for dogs that require blood transfusion. To assess the safety of the technique, experimental laparoscopic splenectomies were performed in dogs for the first time in Iran. Three adult male mixed-breed dogs were placed in dorsal recumbency at a 45° angle in the right lateral position, under aseptic condition and general anesthesia. Three trocars were placed; at the umbilicus, 3 cm cranial to the umbilicus and in the right caudolateral abdomen. The spleen was rotated 90° laterally and thermal coagulation of the blood vessels was performed by bipolar electrocautery. The pedicles were checked to ensure hemostasis. The spleen was morcellated and removed from the umbilical port using a retrieval bag. The mean surgery time was 42 minutes, and all dogs survived the surgery without complications. Laparoscopic splenectomy via three portals was found to be easy and safe.
- انتشار مقاله: 11-10-1348
- نویسندگان: جلال بختیاری,Azin Tavakoli,Alireza Khalaj,Shiva Ghasempoor
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Surgery
- نوع مقاله: Journal Article
- کلمات کلیدی: Laparoscopy,Ovariectomy,queen
- چکیده:
- چکیده انگلیسی: Objective- The purpose of this study was to compare two portal laparoscopy and conventional approach for ovariectomy in queen. Design- Retrospective study. Animals- Adult healthy queens (n=24). Procedures- Queens referred to the small animal hospital, Faculty of Veterinary Medicine, University of Tehran for neutering were randomly assigned for two-portal laparoscopy (n=12) and midline open ovariectomy (conventional approach; n=12). General anesthesia was performed using the combination of ketamin (5.5 mg/kg; i.v.; Ketalar®, Alfasan) and diazepam (0.27 mg/kg; Valium®, Caspian, i.v.) followed by isoflurane in oxygen entubation. Results- Surgical time, length of surgical incisions and recovery time were significantly lower in laparoscopic (11.9±0.95 min, 15.9±0.18 mm, 40.4±4.29 min) compared to conventional ovariectomy (20.7±0.95 min, 27.4±1.27 mm, 58.5±5.58 min; P<0.05). Conclusions- In conclusion, two portals laparoscopy is a simple, safe and suitable approach for elective neutering in queen.
- انتشار مقاله: 15-08-1392
- نویسندگان: Jalal Bakhtiari,Navid Salmanzadeh Zahedani,Alireza Khalaj,Behnam Vafadari,Amir Niasari Naslaji
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Surgery
- نوع مقاله: Journal Article
- کلمات کلیدی: Dog,Gastrectomy,Gastroscopy
- چکیده:
- چکیده انگلیسی: Objective- Comparative endoscopic evaluation of two reconstructive methods (R&Y and jejunal loop interposition) after gastrectomy in dogs. Design- Experimental study. Animals- Ten healthy male dogs. Procedures- The animals were divided randomly in two groups. After a 12 hour food withhold and under general anesthesia laparotomy is performed in all dogs. In group A (R&Y), after dissection and resection of all gastric vessels and ligaments, the stomach was resected cranially close to cardia and caudally close to pylorus. After gastrectomy duodenal end was closed in a two layer inverting suture pattern. Then a loop of jejunum 20 cm distal to Treitz ligament was identified and resected. End to side anastomosis was performed between the distal jejunal end and remained part of the stomach. The proximal jejunal end was end to side anastomosed to the rest of jejunum. In group B (JLI), gastrectomy was done in the same manner. The 20 cm length of jejunum was resected from a 20 cm distance to Treitz ligament. The proximal end of the jejunal loop was end to side anastomosed to the remained part of the stomach and the distal end was anastomosed to the proximal jejunum. Finally jejunojejunostomy was performed between the two Jejunal parts. 1 month after surgery, esophagoscopic and gastroscopic evaluation was performed to rule out the reflux esophagitis or gastritis. Results- Esophagoscopy and gastroscopy thirty days after operation revealed normal appearance at gastroduodenal and duodenojejunal anastomotic junctions. There was no report of enterogastric biliary reflux (EBR) in esophagus or alkaline gastritis. A 2 cm to 2 cm ulcerative mass was observed in the remained part of stomach close to gastrojejunal anastomotic site in one patient in group A. Also regurgitation was noticed in the same patient. A 1 cm to 1 cm ulcer was reported in one patient in group B. Morphology of all anastomotic sites was normal. They were all patent and healed normally without any signs of inflammation. Conclusion and Clinical Relevance- The results of this study showed that the JLI like R&Y technique is a successful method to prevent reflux esophagitis.
- انتشار مقاله: 22-05-1392
- نویسندگان: Mahboobeh Abdi,Jalal Bakhtiari,Shahram Jamshidi,Azin Tavakoli,Alireza Khalaj
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Surgery
- نوع مقاله: Journal Article
- کلمات کلیدی: Laparoscopy,Radiography,Gastrojejunostomy
- چکیده:
- چکیده انگلیسی: Objectives- To evaluate radiographic changes and macroscopic findings in handsewn laparoscopic gastrojejunostomy in dogs. Study Design-Elective experimental study Animals-Eighteen mix-breed healthy male and female dogs. Methods-Animals were divided in two equal groups randomly. Two layers handsewn laparoscopic side to side gastrojejunostomy was performed in the control group and one layer in the treatment group. Cases were monitored for four weeks. Contrast radiographs were taken in the first and last week of the study. Cases were sacrificed after four weeks and macroscopic findings were evaluated at the anastomotic site and it’s diameter was measured. Results-There was no evidence of stricture, stenosis or organ displacement radiographically. No infection, stricture, fistulae formation, abscess, ischemia or gross granulation tissue was seen, but several adhesions were found in the abdominal cavity macroscopically. The most frequent adhesion was between omentum and the anastomotic site which was reported in all cases. There were no statistically significant difference between the anastomotic diameter in both groups (P>0.05). Conclusion and clinical relevance- One layer laparoscopic handsewn gastrojejunostomy is a safe and feasible technique without serious complication with no statistically significant difference with the conventional two-layer technique.
- انتشار مقاله: 09-06-1392
- نویسندگان: Azin Tavakoli,Jalal Bakhtiari,Mohammad Javad Gharagozloo,Alireza Khalaj,Abbas Veshkini,Davood Sharifi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Surgery
- نوع مقاله: Journal Article
- کلمات کلیدی: Laparoscopy,suture pattern,Gastrojejunostomy
- چکیده:
- چکیده انگلیسی: Objectives-To evaluate the clinical safety and feasibility of one layer suture pattern technique in gastrojejunostomy in dog in comparison to two layer suture pattern technique. Study Design-Elective experimental study. Animals-Sixteen mix-breed healthy male and female dogs. Methods-Sixteen healthy male and female dogs were randomly divided in two groups. In the control group the two layer side to side laparoscopic gastrojejunostomy were performed. In the case group the one layer anastomosis between stomach and jejunum were done. Clinical parameters include body temperature, heart rate, respiratory rate, CRT, mean surgical time, blood loss, surgical complications, CBC, total protein, albumin and weight loss were evaluated. Results-There were no significant differences between body temperature, heart rate, respiratory rate, CRT, CBC, total protein and albumin in both groups. There was significance difference between mean surgical time and blood loss and in two groups. Conclusion and Clinical Relevance- Laparoscopic gastrojejunostomy with one layer closure technique based on clinical data revealed several advantages include feasibility, safety and less time consuming in comparison to two layer suture pattern technique.
- انتشار مقاله: 28-05-1392
- نویسندگان: Azin Tavakoli,Jalal Bakhtiari,Alireza Khalaj
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Surgery
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: Objectives- To introduce laparoscopic ovariohysterectomy in dog in Iran, Study Design- Elective experimental study design. Animals- Four mix-breed healthy female dogs. Methods- Four healthy female dogs were undergone elective laparoscopic ovaryohysterectomy. Clinical parameters including: body temperature, heart rate, respiratory rate, appetite, surgical time, blood loss, surgical complications, CBC and pain scores were evaluated. Results- CBC of the dogs were not indicator of infection but the stress leuckogram was evident till 48 hours after the surgery. Median pain scores 2 and 4 hours after the surgery were low (pain scores less than 6) and 24 hours post operatively were very low (pain scores less than 2). The blood loss was minimumand the operations had no complications. Appetite, body temperature, respiratory and heart rate returned tonormal values in a short period (48 hours). Conclusions and Clinical Relevance- Laparoscopic ovariohysterectomy is safe and could be performedin a reasonable time with minimal pain in dogs.
- انتشار مقاله: 26-01-1393
- نویسندگان: Jalal Bakhtiari,Sarah Mokaram,Alireza Khalaj,Davood Sharifi,Azin Tavakoli
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Single-crystal X-ray diffraction,four-coordinate,1D copper(I) coordination Polymer,Microparticles
- چکیده:
- چکیده انگلیسی: In this research, 1D four-coordinate copper(I) coordination Polymer [Cu(Clba2-1,2-pn)(NCS)]n (1) with thiocyanate anion as bridging ligand, where Clba2-1,2-pn = N,Nʹ-bis(2,4-chlorobenzylidene)propane-1,2-diamine), was synthesized by slow evaporation of solvent at room temperature and characterized by elemental analysis (CHN) and single-crystal X-ray diffraction. Microparticles of 1 were prepared by an ultrasonic bath assisted synthesis and characterized
by Scanning Electron Microscopy (SEM) and elemental analysis. Thermal stability of 1 was studied by ThermoGravimetry (TG) and Differential Thermal Analysis (DTA). The structure of 1 consists of 1D polymeric chain in which copper(I) ions are bridged by two thiocyanate groups in an end-to-end fashion, with Cu×××Cu separation 5.686(4) Å.- انتشار مقاله: 13-09-1396
- نویسندگان: Aliakbar Dehno Khalaji,Seyyed Javad Peyghoun,Ali Reza Akbari,Nourollah Feizi,MichalMichal Dusek,Vaclav Eigner
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Schiff base,Nanoparticles,XRD,SEM,Copper(II),Nickel(II)
- چکیده:
- چکیده انگلیسی: A new tetradentate N2O2 Schiff base ligand (MeO-bph)2bn = N,N¢-bis(2-hydroxy-4-methoxybenzophenone)-1,4-butanediamine was prepared from the condensation of butane-1,4-diamine with 4-methoxy-2-hydroxybenzophenone and characterized by 1H-NMR spectroscopy and single-crystal X-ray diffraction. Its nickel(II) and copper(II) complexes characterized using elemental analyses (CHN) and IR spectroscopy. Thermogravimetric analysis of the Schiff base ligand and its Ni(II) and Cu(II) complexes revealed their thermal stability and decomposition pattern. Finally, the complexes were used for the preparation of NiO and CuO nanoparticles by solid-state thermal decomposition. The nanoparticles were characterized by FT-IR, XRD, and SEM. FT-IR and XRD confirmed the purity of the formed products NiO and CuO.
- انتشار مقاله: 03-11-1395
- نویسندگان: Aliakbar Dehno Khalaji,Maryam Ghorbani,Michal Dusek,Vaclav Eigner
- مشاهده