Background and Aim: Application of varnish and dentin bonding agents can effectively reduce microleakage under amalgam restorations. Also rebonding may show some effects on microleakage and its complications. The aim of this study was to evaluate the effect of liner/ adhesives on microleakage of Class V amalgam restoration with or without rebonding.Materials and Methods: In this in vitro study Class V cavities were prepared on sixty sound human maxillary premolars with the gingival floor 1mm below the CEJ. Cases were divided into six groups of ten teeth each. Specimens in group 1 and 2 were lined with Copalite and Scotchbond Multi-Purpose (SBMP) respectively. In the third group (control) no liner was applied. The teeth were then restored with spherical amalgam. Specimens in group 4 to 6 received the same treatments but after filling, the interfaces of restorations and teeth were etched with 37% phosphoric acid gel, rinsed and dried. Adhesive resin of SBMP was applied over amalgam and tooth margins and polymerized (rebonding). Specimens were thermocycled, exposed to dye and sectioned. Microleakage was graded (0-3) using a stereomicroscope at X40 magnification. Data were analyzed with Kruskal-Wallis, Mann-Whitney and Wilcoxon pair wise statistical tests. P<0.05 was considered as the limit of significance.Results: The groups lined with SBMP showed the lowest and the groups without liner the highest microleakage (p= 0.001). Significant difference was observed in microleakage mean rank of enamel and dentin margins (p=0.048). Rebonding with resin did not improve the seal (p> 0.05).Conclusion: Based on the results of this study, total etch adhesive system had significant effect on microleakage of Class V amalgam restorations especially in cervical margin. Rebonding did not show a significant effect on microleakage.

The shell liner type, rotation speed, and ball filling percent are the key factors influencing the charge behavior inside the SAG mills, and consequently, their performance. In this work, the milling operation of industrial SAG mills is investigated using the Discrete Element Method (DEM). First, an industrial SAG mill with dimensions of 9. 50 m × 4. 42 m that has a Smooth-type liner is simulated. Then by changing the liner types, i. e. Wave, Rib, Ship-lap, Lorain, Osborn, and Step liners, six other independent simulations are performed. In order to investigate the impact mechanism and improve the mill performance, two new parameters called ‘ head height’ and ‘ impact zone length’ are introduced. Then the effects of the mill shell liner type on those parameters at two different mill speeds, i. e. 70% and 80% of its critical speed (CS), are evaluated. Also for validation of the simulation results, a laboratory-scale SAG mill with dimensions of 57. 3 cm × 16. 0 cm is simulated. The results obtained indicate that the Osborn liner, due to the angularity of its lifters and their proper number and thickness, performs best because it increases both parameters more than the other liners. Thus this liner is recommended as the best and optimal liner in this research work and is suggested for installation inside the industrial SAG mills. Also the Wave liner, due to its specific geometrical shape and its wavy lifters as well as their low number and inadequate thickness, provides the lowest charge ‘ head height’ . Therefore, it is not recommended to install this liner inside the industrial SAG mills. Meanwhile, comparison of the simulations related to the laboratory-scale SAG mill with the experimental results demonstrates a good agreement that validates the DEM simulations and the software used.

The mill shell liner type, rotation speed and the amount of its loading are the key factors influencing the charging behavior, consequently the comminution mechanism. In this paper, the milling operation of industrial ball mills using the Discrete Element Method (DEM) is investigated. First, an industrial scale ball mill with a Smooth liner type is simulated. Then, by changing liner type, i. e. Wave, Rib, Ship-lap, Lorain, Osborn, and Step liners, six other independent simulations are performed. Effects of mill shell liner type on charge shoulder, toe, impact, and head points, also on head height and impact zone length as well as on the creation of cascading, cataracting, and centrifuging motions for balls at two different mill speeds, i. e. 70% and 80% of its critical speed (NC) are evaluated. Also, in order to validate simulation results, a laboratory-scale mill is simulated. The results indicate that the charge heads are respectively about 240. 13, 283. 40, 306. 47, 278. 12, 274. 42, 274. 42, and 278. 12 cm at the simulations performed with Smooth, Wave, Rib, Ship-lap, Lorain, Osborn, and Step liners at 70% of NC. The corresponding values at 80% of NC are as follows: 256. 08, 264. 56, 313. 54, 298. 45, 313. 54, 311. 60, and 283. 40 cm. On the other hand, the impact zone lengths are respectively about 33. 14, 22. 11, 38. 63, 35. 86, 38. 63, 38. 63, and 49. 59 cm at the simulations performed with the above-mentioned liners at 70% of NC. The corresponding values for impact zone lengths at 80% of NC are as follows: 35. 86, 27. 63, 49. 59, 38. 63, 33. 14, 52. 32, and 41. 38 cm. Comparison of the simulations related to the laboratory scale mill with experimental results demonstrates a good agreement that validates the DEM simulations and the software used.

Introduction: In some special situations during the revision total hip arthroplasty with well fixed، well oriented acetabular cementless cup، orthopedic surgeons may prefer to retain the well-fixed cementless cup. The aim of this study was to report the follow-up of some cases treated with such a technique during a 10-year period. Methods: During 2004-2014، all cases of revision total hip surgery performed in Sina Hospital، Tehran، Iran were evaluated. 14 of 82 cases (16. 5%) had cemented polyethylene liner in cementless metal shell. The demographic data، reasons for use of such revision technique result was evaluated by Harris Hip Score. Results: The most common reason was osteolysis (64%)، and the most common cause was impaired locking mechanism (65%). There were few complications (one osteolysis and one infection). In five cases (36%) constrained liner was added and in 10 cases (72%) allograft was needed. The final Harris Hip Scores was good or excellent in 78%. Only one dislocation was seen. Conclusion: Cemented cup in cementless shell can be used in revision hip arthroplasty in well-fixed Acetabular shell situations with acceptable outcom.

Paratuberculosis caused byMycobacterium avium subsp. paratuberculosis (Map) is a progressive, chronic and noncurable granulomatous enteritis. Paratuberculosis affects ruminants worldwide. The earliest reports on paratuberculosis in Iran date back to 1960’s when the disease was diagnosed in imported animals of the Abadan Oil Company’s farm. In the work presented here 13 field MAP isolates including 4 ovine and 3 caprine isolates from Isfahan, 6 bovine isolates from Zanjan and Alborz provinces plus 2 vaccinal strains of 316F and III & V were subjected to PCR-IS900, PCR-F57 for identification and also PCR-Collins for typing. In consequence, while an identical PCR protocol was successfully developed to simultaneously perform all the three experiments, the 15 tested bacteria were all shown to be MAP Type II (cattle type). In epidemiological sense, when the size of national goat, sheep and cattle herds of Iran is taken into account, circulation of MAP Type II is intriguing.

In this paper, the effect of the liner material model on the result of numerical simulation of Explosively Formed Projectile (EFP) is examined. Johnson-Cook, Steinberg, and Zerilli-Armstrong models are used for the simulation. All models are shown that have a good agreement with the experimental results. Zerilli-Armstrong model predicts final EFP shape with more accuracy in comparison with the other models. The results of simulations indicate that Johnson-Cook and Steinberg models predict the projectile length better than Zerilli-Armstrong model. The velocity of projectile predicted by all models agrees well with the experimental measurement.

Marine diesel engines are in the heavy duty diesel engines group with high output power. These engines have wet liner sleeve that cooling water surrounded it. The cooling heat transferred to space water. The engine combustion in one side and cooling water and liner interaction at other side create different physical and chemical phenomena. Liner cracking and fracture is probable phenomenon and have different reasons such as over thermal stresses, cavitation or corrosion. These failures cause to general engine overhaul and liner replacing. This paper presents the study of liner cracking of V12 marine diesel engine. The results have shown that the increasing of the cooling water temperature accelerates the liner fatigue and cracking. Liner corrosion and cavitation have additional effects on this failure.

Aim and Background: Laryngeal mask is an airway control equipment which is replaced by endotracheal tube in general anesthesia in many surgical procedure. This study compares the efficacy and safety of LMAc and SLIPA.Methods and Materials: This study was a single-blind, randomized clinical trial that was conducted on 320 patients between the age of 15-70, ASA I -II, BMI less than 35, in general surgery, orthopedic surgery, urologic and gynecologic surgery. With the operating time less than an hour. Insertion of LMA and SLIPA, insertion time, determining the gastric air insufflation and the easiness difficulty of removing the mask and the severity of sore throat was recorded.Findings: Insertion was straightforward in 74.38% and slightly difficult in 25.62% for SLIPA cases versus straightforward in 66.87% and slightly difficult in 28.75% and obviously difficult in 4.38% for the LMAc cases. Average insertion time was also significantly shorter in SLIPA than LMAc (34.57 seconds vs. 45.56 seconds). Between two groups in the amount of air entering the stomach and difficulty in removing the device Sore throat with a higher intensity of 5 was more in LMAc than SLIPA but cases without sore throat were higher in LMAc group (20% vs. 13%). Blood contamination of the device after its removal was significantly higher in LMAc group.Conclusions: Suitability of the SLIPA in small and short term surgery has been proved, but its effectiveness in longer surgery requiring mechanical ventilation needs more investigation.