In this paper, the flow field around a two-dimensional Rectangular cylinder was numerically simulated and the effects of the flow Suction on the separation bubble were investigated. The purpose was to estimate the effect of Suction on the dimensions of the separation bubble. The flow field was assumed incompressible, turbulent, and two-dimensional. Gambit software was used for grid generation and FLUENT for numerical simulation. The problem was analyzed in two states: with and without Suction, and the effect of Suction on the separation bubble was investigated. According to the results, it can be said that the Suction length of the separation bubble is smaller, so that in several different cases this length is reduced by about 50%.

Dear editor, Suction syringes are utilized to produce blisters for epidermal grafts, as well as for treating localized and stable vitiligo with better cosmetic acceptability. However, the Suction process should be fast to save time. The 3-way cannulasyringe can produce blisters within 1 to 2 h (1). Moreover, the failure of this device at-300 to-400mmHg to produce a Suction blister and the incidence of incomplete blisters at the site are seen in about 20 to 30% of cases (2, 3). The success rate is improved by the application of heat, intralesional injection of normal saline and local anesthetic agents over the donor site. Thus, the 3-way cannula-syringe is a little cumbersome and time-consuming device...

In this research, in order to investigate the effect of the piezoelectric patch which is used as a sensor or actuator in rotating flexible structures such as a helicopter blade, the free vibrations of the rotating Rectangular sheet with and without the piezoelectric patch have been presented. First-order shear deformation theory is considered for plate displacement and piezoelectric field. Considering the effect of Coriolis acceleration, centrifugal acceleration and centrifugal in-plane forces, the equations of motion are derived from Hamilton's principle and the electromechanical couple equation is obtained from Maxwell's equation. For piezoelectric, two electrical conditions, open circuit and closed circuit, which are used in sensors and actuators, respectively, have been considered. The equations are discretized with the help of the numerical method of generalized differential squares and the matrices of inertia mass, eccentricity, Coriolis and stiffness matrix are obtained. Natural frequency values for beam and rotating plate have been compared in Abaqus software. Also, the values obtained from the numerical solution in MATLAB have been verified with articles and ABAQUS, which have high accuracy. The effect of parameters such as hub radius, rotation speed, sheet thickness, aspect ratio, piezoelectric patch thickness and applied voltage on the natural frequency of the system has also been investigated.

INTRODUCTION: Blockage of the lacrimal drainage system results in impairment of normal tear channeling into the nose. Dacryocystorhinostomy (DCR) operation, which involves fistulization of the lacrimal sac into the nasal cavity, may alleviate the symptoms. The operative approach to the sac may be external or endoscopic. In endoscopic DCR, laser, rongeur, drill, curette and chisel have been used to remove the nasal mucosa, lacrimal bone and the thick bone of the maxilla forming the anterior lacrimal crest and lacrimal sac to establish lacrimal drainage. In this study we used Suction cautery to remove nasal mucosa in bloodless field. METHODS: Suction cautery-assisted DCR was performed on 43 patients (31 female and 12 male) with chronic epiphora or dacryocystitis who underwent operation during 2002-2003 in Kashani Hospital, Isfahan. The technique involved usage of Suction cautery and true cut forceps for removal of mucosa and bone over the lacrimal sac. The follow-up period was 6-12 months and the patients had a mean age of 38.7 years. RESULTS: The endoscopic DCR was successful in 38 of the 43 cases (88.3%). Four cases of failure in the first operation were reevaluated in the second operation. Complete bony closure and reformed bone was observed in one of these cases. In the other three cases, adhesion of middle turbinate and rhinostoma was the cause of failure and the endoscopic technique was easily performed. DISCUSSION: Excellent patient tolerance was observed, with minimal morbidity and no major complications. As compared to the external approach, endoscopic Suction cautery-assisted DCR is less traumatic, less time-consuming, practical and cosmetically convenient, with minimal preoperative and postoperative complications. It also allows simultaneous correction of any intranasal disease. It requires minimal instrumentation and is a relatively easy and fast technique.

Background: There are 2 different methods of Suctioning the airway: the open tracheal Suction system (OTSS) and the closed tracheal Suction system (CTSS). The aim of this study was to compare the efficacy of the OTSS and the CTSS in maintaining the stability of hemodynamic and oxygen parameters in patients after cardiac surgery. Methods: This randomized controlled clinical trial was conducted on 60 patients who were under mechanical ventilation after cardiac surgery. The study population was randomly divided into the OTSS and CTSS groups. All the patients were at least 18 years old and hemodynamically stable. Hemodynamic parameters such as systolic and diastolic blood pressures were measured. Oxygen parameters such as the saturation percentage of arterial blood oxygen (SpO2) and the oxygen pressure of arterial blood (PaO2) were measured before, immediately, and also 3 and 5 minutes after Suction. All the parameters were compared between the 2 groups. Results: The mean heart rate, the mean systolic blood pressure, and the mean arterial blood pressure showed a higher increase in the OTSS group (P<0. 05), whereas the mean PaO2 and SpO2 were higher in the CTSS group (P<0. 05). Conclusions: The CTSS caused fewer disturbances in the hemodynamic and oxygen parameters in comparison with the OTSS in our study population. Therefore, disturbances in the aforementioned parameters can be avoided by using the CTSS in patients undergoing cardiac surgery.

Dear Editor, Suction devices are used to produce blisters for epidermal grafting over the vitiliginous patch and achieve a good cosmetic result, but the process takes 1 to 3 hrs11-3. To hasten the Suction process, heat and normal saline intralesional injection can be given over the site,the blister formation takes about 1 hour using a modified disposable syringe with a small disposable syringe cup and a threeway cannula 4, 5. However, the cup Suction device is small and more stable than the syringe device, and it is easier to create negative pressure in the Suction cup. Considering the advantages of the small three-way cannula-cup device over longer Suction devices, a set of small cups of various radii can be used to produce Suction blisters...

Packing Rectangular shapes into a Rectangular space is one of the most important discussions on Cutting & Packing problems (C&P); such as: cutting problem, bin-packing problem and distributors pallet loading problem, etc. Assume a set of Rectangular pieces with specific lengths, widths and utility values. Also assume a Rectangular packing space with specific width and length. The objective function is, to pack the pieces into the space in Order to get the maximum sum of utility value of the packed pieces. To generate the related packing pattern this paper proposes a new formulation metl10dbased on the column generation, approach. In this method one each cycle of the algorithm; a one-dimensional pattern is generated based on the shadow prices 'Of the Simplex method. The set of generated one-dimensional patterns are used: to construct the two-dimensional packing pattern. Also, the proposed model and the present models in the.state-of-1beart have been compared.

Objectives: To report the authors’ experience in Suction and evacuation with cannula followed by maintenance of negative pressure in the uterine cavity by keeping the cannula inside for 20-30 minutes, which was performed for controlling intractable postpartum hemorrhage (PPH) in a tertiary care hospital.Materials and Methods: This is a retrospective observational study carried out from July 2011 to December 2012 at Batra Hospital and Medical Research Centre, New Delhi, India. Nine patients who delivered either vaginally or via caesarian section and developed primary PPH refractory to conventional medical treatment, were included in the study. Suction and evacuation of the uterine cavity was done and then the cannula was kept inside the uterine cavity for 20-30 minutes thereby maintaining negative pressure (400-600 mmHg) in the cavity. Data were retrieved from patients’ hospital records.Results: Intractable primary hemorrhage was encountered in 9 patients of whom 6 had bleeding after caesarian section and 3 after vaginal deliveries. Uterine atony due to prolonged labour was the commonest cause. Hemorrhage was effectively controlled in 8 out of 9 cases (88.9%) and hysterectomy was avoided. In one patient (11.1%) the procedure failed and life saving hysterectomy was done to control the bleeding. This approach not only controls PPH but also preserves the woman’s reproductive functions and avoids hysterectomy and its related complications and consequences.Conclusion: This is a simple conservative surgical method to treat PPH in low resource settings. It requires minimal training, conserves the uterus, and is technically less challenging and associated with less blood loss than hysterectomy.

An extensive experimental study has been performed to investigate the wind tunnel sidewall effect and the boundary layer Suction on a half model pressure distribution. A three-dimensional half wing was made according to its full span model. The wing was tested at angles of attack ranging from a= -5 to 25 degree and at Reynolds numbers of 0.5*106, 1.0*106 and 1.3*106 in a subsonic wind tunnel. Experimental results such as static pressure distribution, lift coefficient, and wake are compared with the corresponding 2-D results from that of similar model. Wind tunnel sidewall boundary layer Suction effects on the surface static pressure distribution have been studied at various conditions has been studied. The results show that the flow over the portion of the model affected by the sidewall pressure separates at an angle of attack which is smaller than the corresponding angle for other portion of the wing. This phenomenon yields an increase in the drag coefficient and a noticeable decrease in the value of the lift coefficient. However, when Suction was applied to the sidewall, separation was delayed to higher angles, and the corresponding aerodynamic loads varied significantly.