Introduction: The aim of the present study was to compare the amount of apical debris extrusion after preparation using hand files, reciprocating files, and full rotary nickel-titanium systems. Methods and Materials: One hundred extracted human mandibular molars with two separated canals in mesial root were divided into five groups and prepared using reciprocating systems (Reciproc file and Safesider endodontic reamers file), full rotary systems (Mtwo and Neoniti A1 files) and hand instrumentation systems. Endodontic access was prepared and a #15 K-file was passed beyond the apex of the mesiobuccal canal by 1 mm to ensure the canal patency. All mesiobuccal canals were prepared 1 mm shorter than the anatomic apex. In each case, extruded debris was collected in an Eppendorf tube and weighed after desiccation. The mean weight of extruded material was calculated in each group. The analysis was carried out using the Kruskal– Wallis test followed by two tailed and Mann-Whitney U test at a significance level of 0. 05. The Bonferroni correction was also applied to correct multiple comparisons. Results: There was a statistically significant difference between the reciprocal and other techniques in debris extrusion (P<0. 05). The order of groups ranked in terms of debris extrusion from the lowest to highest was as follows: 1) Hand instrumentation group (with crown down technique), 2) Mtwo group, 3) Neoniti A1 group, 4) Safesider endodontic reamer group, and 5) Reciproc group. Conclusion: Based on this in vitro study, all systems have some apical debris extrusion; however, using the hand instrumentation system resulted in extrusion of significantly less debris compared to the Reciproc group. It seems that hand and rotary instrumentation systems are better than reciprocating instrumentation systems in terms of the amount of debris extrusion.

One of the old methods of butter production, which is still used in parts of Africa and the West of Asia, is the process of churning in the skin of a goat or deer that is half filled with milk or yogurt and air, which is beaten reciprocating. This type of butter production in the current research is mechanized and is called machine-type reciprocating butter churner (MRBC). This device is composed of chassis, churner, churn carrier, connector or crank, rotating wheel, driving system or power transmission and balance weights. In order to evaluate MRBC, the effect of churning amplitude (40, 60 and 80 cm), churning frequency (50, 61 and 72 cpm) and the churner volume (13.5 and 21.3 liters) on the butter yield was investigated. The results showed that the amplitude, frequency and churner volume had a significant effect on the butter yield at the level of 1%. Regardless of the churner volume, the minimum and maximum butter yield was obtained in the lowest and highest amplitude and frequency, respectively. The present study gives a general overview of the butter yield affected by machine mechanical parameters.

Introduction: Different techniques have been proposed to help achieving apical patency during endodontic treatment and retreatment. The objective of this in vitro study was to compare reestablishment of apical patency in teeth previously subjected to root canal treatment using manual and reciprocating instruments. Methods and Materials: A total of 40 single-rooted extracted human mandibular incisors were selected and prepared using the Hero 642 sequence to 45/0. 02 and obturated using Tagger’ s hybrid technique to 1 mm short of the apex. Teeth were divided into two groups according to the type of instrument used to regain patency: group 1, hand K-files and group 2, reciprocating WaveOne Primary files (25/0. 08). Fisher’ s exact test was used in the statistical analysis. Result: In group1, apical patency was regained in 9 of the 20 teeth tested (46%), compared to 20 teeth (100%) in group 2. The difference between the groups was significant (P<0. 0001). Conclusion: Our study shows that reciprocating instrumentation is more successful in regaining apical patency in single-rooted, previously treated teeth.

There exist various ways to extract water from a well and transfer it to farmland. This work attempts to design a reciprocating pump, which utilizes wind energy to extract and transfer water. Due to its efficiency, in terms of low operating costs, this method, once operational, would be capable of transferring water from a well to the point of consumption on farmland. A complete description of the design features, along with all the relevant documents, will be presented in this article.

Double action horizontal Neuman Esser reciprocating compressors are utilized during three steps of compressing hydrogen in gasoline production section of many refineries including Esfahan refinery. Since application of any lubricant during compression process are not permitted in these compressors, Teflon ridder rings are placed between piston and cylinders to act as a lubricant and prevent any direct contact between pistons and cylinders. The wearing rate of the ridder rings in these three stages are not equal and consequently the time for their maintenance is not the same. In this research it is intended to increase the life of ridders by reducing the weight of pistons. After studying the effects of replacing the cast iron material of pistons by 7075 aluminum alloy, genetic algorithm is implemented to optimize the design of these pistons. Maximum von-Misses stress and minimum allowable thickness of various sections of piston are the constraints considered during optimization process and Abaqus finite element technique using Python script are utilized during optimization. Replacement of the material reduces the piston weight from 780 kg down to 271 kg and by optimizing the piston design, it was further reduced down to 261 kg which totally could considerably reduce the wearing rate of riders by reducing the total normal force on riders.

Vortex rings can maintain their structure during motion and achieve long-distance transport with low energy consumption, which is a fluid transport method with great energy-saving potential. In this paper, a reciprocating vortex ring generator structure is designed, which can generate two vortex rings during the reciprocating motion of one piston, making full use of the thrust in the reciprocating motion period of the piston and improving the vortex ring generation frequency compared with traditional vortex ring generators. For the characteristics of long-distance transport of vortex rings, an experimental platform is designed and built, and 277 sets of experiments are carried out with different geometric parameters. The results show that the effect of generating two vortex rings could be achieved under other parameter conditions, except for some parameter conditions where the diameter ratio D1/D2 = 4. By analyzing the influence of baffle width ratio, length ratio, and diameter ratio on the moving distance of vortex rings, the performance of the vortex ring generator is preliminarily studied. In 277 sets of experiments, the maximum moving distance ratio x1 of vortex ring 1 is 13. 7 when L1/L2 = 2. 4, D1/D2 = 2, and w1 = 0. 2. And the maximum moving distance ratio x2 of vortex ring 2 is 20 when L1/L2 = 2, D1/D2 = 2. 5, and w2 = 0. 2.

Reciprocating compressors are critical equipment in air separation unit plant systems designed to convey fluids from the site to the customer through pipelines. The key point is long component life without compromising reliability and safety systems. Therefore, appropriate maintenance strategies are required to improve system reliability and safety, considered key performance indicators that strongly impact cost, safety, and environmental sustainability. Functionality risks are assessed based on several relevant documents from the original equipment manufacturer's (OEM) best practices regarding international and community standards applied to each component. This paper shows the integration of bibliographical research and vulnerability study assessment; it provides additional information by preventing failure and identifying opportunities for continuous improvement, where the process is carried out using failure mode and effect analysis (FMEA) by issuing recommended action to the planned maintenance routine task list.  The following paper aims to determine reliable and safe maintenance requirements to obtain up to 99.9% availability.

Introduction: This ex vivo study aimed to compare the adaptation of single gutta-percha cone in teeth prepared with the Wave One Gold and Reciproc Blue reciprocating systems through cone-beam computed tomography. Materials and Methods: A total of 40 recently extracted mono radicular premolars were randomly assigned into two groups (n=20) corresponding to Reciproc Blue and Wave One Gold reciprocating systems and adapted to a single cone system. Each group was evaluated by cone-beam computed tomography at 1 mm, 2 mm and 4 mm from the apical foramen. We evaluated the number of walls adapted by the cone, quality of filling and the number of spaces between the filling and the walls of the root canal. The Mann-Whitney U and T-tests were employed to associate and compare both groups (P<0. 05). Results: At 1 mm in the lingual wall the Wave One Gold system did not adapt by 45% compared to 15% with Reciproc Blue (P<0. 05). Likewise, the single-cone filling technique of the Reciproc Blue system showed better sealing quality obtaining an ideal category (75%) compared to Wave One Gold (40%) (P<0. 05). The amount of space (mm) found between the cone and the filling walls was greater with Wave One Gold. However, these values were not statistically significant. Conclusions: Based on this ex vivo study the better adaptation of root canals and ideal filling condition was more frequent with Reciproc Blue than Wave One Gold system, mainly at 1 mm from the radicular apex.