Bench Device Research Articles

Linear Cutting Performance Tests and Parameter Optimization of Poplar Branches Based on RSM and NSGA-II

To reduce the cutting force and cutting energy consumption during the operation of tree-climbing pruning machines for poplar trees, a linear cutting test bench device for branches was designed according to the growth characteristics of poplar branches and pruning forestry requirements in this study. Firstly, the cutting mechanical analysis of poplar branches was carried out to explore the significance parameters affecting the cutting force, and then the cutting performance test and parameter optimization of poplar branches was carried out through the response surface method (RSM). The test results indicated that cutting speed, tool edge angle and tool back angle had significant effects on the ultimate shear stress, cutting power consumption per unit area, and the branch damage rate of poplar branches, and the established regression equation demonstrated high goodness of fit. Meanwhile, a second-order regression mathematical model was developed between ultimate shear stress, cutting the power consumption per unit area of the cut and the branch damage rate, and the significance parameter. The non-dominated Sorting Genetic Algorithm II (NSGA-II) was used for multi-objective optimization computation to obtain the optimal combination of cutting parameters as 3.02 m/s for cutting speed, 15° for tool edge angle, and 3° for tool back angle. In this case, the ultimate shear stress, cutting power consumption per unit area, and branch damage rate of poplar branches were small, which were 346.63 kPa, 9.35 mJ/mm2, and 12.36%, respectively. Through the test verification, it can be seen that the relative error between the verification test and the predicted value of model was less than 7%. Moreover, under a cutting tool edge angle of 15°, the ultimate shear stress, cutting power consumption per unit area, and branch damage rate were, respectively, reduced by 17.29%, 14.98%, and 34.21% compared with those under a cutting tool edge angle of 20°, which verifies the validity and reliability of the test results and the research method. This study can provide data support and reference for the research and development of energy-efficient poplar tree-climbing pruning equipment and related branch-cutting performance tests.

Comparison of a new bioprosthetic mitral valve to other commercially available devices under controlled conditions in a porcine model.

Background/AimTo evaluate three mitral bioprostheses (of comparable measured internal diameters) under controlled, stable, hemodynamic and surgical conditions by bench, echocardiographic, computerized tomography and autopsy comparisons pre‐ and postvalve implantation.MethodsFifteen similar‐sized Yorkshire pigs underwent preprocedural computerized tomography anatomic screening. Of these, 12 had consistent anatomic features and underwent implantation of a mitral bioprosthesis via thoracotomy on cardiopulmonary bypass (CPB). Four valves from each of three manufacturers were implanted in randomized fashion: 27‐mm Epic, 27‐mm Mosaic, and 25‐mm Mitris bioprostheses. After CPB, epicardial echocardiographic studies were performed to assess hemodynamic function and define any paravalvular leaks, followed by postoperative gated contrast computerized tomography. After euthanasia, animals underwent necropsy for anatomic evaluation.ResultsAll 12 animals had successful valve implantation with no study deaths. Postoperative echocardiographic trans‐valve gradients varied among bioprosthesis manufacturers. The 25‐mm Mitris (5.1 ± 2.7)/(2.6 ± 1.3 torr) had the lowest peak/mean gradient and the 27‐mm Epic bioprosthesis had the highest (9.2 ± 3.7)/(4.6 ± 1.9 torr). Surgical valve opening area (SOA) varied with the 25‐mm Mitris having the largest SOA (2.4 ± 0.15 cm2) followed by the 27‐mm Mosaic (2.04 ± 0.23 cm2) and the 27‐mm Epic (1.8 ± 0.27 cm2) valve. Bench device orthogonal internal diameter measurements did not match manufacturer device size labeling: 25‐mm Mitris (23 × 23 mm), 27‐mm Mosaic (23 × 22 mm), 27‐mm Epic (21 × 21 mm).ConclusionsCurrent advertisement/packaging of commercial surgical mitral valves is not uniform. This study demonstrates marked variations in hemodynamics, valve opening area and anatomic dimensions between similar sized mitral bioprostheses. These data suggest a critical need for standardization and close scientific evaluation of surgical mitral bioprostheses to ensure optimal clinical outcomes.

Development of integrated hardware-in-the-loop (hil) test bench anti-lock brake system (abs) instrument

Carrying out an Antilock Brake System (ABS) testing performance for ECU-ABS software development validation in real-time by an on-road test drive is challenging. Besides, it requires more time, cost, and effort. This research aims to develop a test bench device for ABS testing performance based on hardware in the loop (HIL). HIL-based ECU-ABS testing performance offers an approach that improves the validation process, and at the same time providing potential cost, time, and energy savings. To achieve this goal, this device is created through experimental development methods and a prototype is built consisting of input/output devices that can be set out and manipulated due to the desired real braking conditions. The result of the study is an ABS test performance device equipped with a data acquisition system (DAQ) hence the parameters which are working during the test can be read, harvested, and further analyzed for the development and improvement of the ABS. The design and prototyping process employ several software (i.e. MatLab, Proteus, Ansys, C++ Compiler, and Visual Basic), hardware (asynchrony motor, speed sensors, hydraulic actuator, PCI-Card LabView, PC, LCD monitor, keyboard, printer), frame structure and flywheel, calibration utility and test space that meets NASVA standards.

Failure analysis of bolts on fatigue test bench for excavator stick

In this study, a new bench device with full-scale fatigue test for excavator stick was designed. The test bench has the function of dynamic load self-balancing, because a part of the load applied to the specimen of stick is directly transferred to the pillars of the test machine through the high-strength bolts connection. Accordingly, the ground under the test machine was not affected by the test load. However, some bolts located on the fatigue test bench failed and fractured during fatigue testing for excavator stick. To determine the failure reasons of bolts, mechanical and scanning electron microscope (SEM) analyses were conducted. The tensile stress of bolt group under ultimate load was evaluated via finite element model (FEM) of test bench according to test load spectrum. Moreover, under the test load spectrum, the stress range of bolt group was obtained and the fatigue life prediction of bolts was conducted by referring to Eurocode 3. It should be noted that the results of numerical simulation of fatigue lives for failure bolts were consistent with the actual lives of failure bolts during test. A fractured surface on one of the failed bolts was examined by SEM observation to determine the failure initiation and failure mode.

Toward a new method to classify the airblast sprayers according to their potential drift reduction: comparison of direct and new indirect measurement methods.

Drift is one of the most important issues to consider for realising sustainable pesticide sprays. This study proposes an alternative indirect methodology for comparative measurements of drift reduction potential (DRP) generated by airblast sprayers, aimed at overcoming the practical inconveniences and drawbacks of standardized ISO 22866:2005. A test bench in the absence of target crop and wind was employed to measure drift potential values (DPVs). A variation to the proposed method that introduced a crop between sprayer and test bench device was considered to study the canopy effect (absence/presence) and to validate the method. In parallel, direct spray drift measurements (ISO 22866) were performed to obtain the drift value (DV). A representative vineyard airblast sprayer was evaluated in four configurations (a combination of two fan airflow rates and two nozzle types). The configurations tested under the three methods (direct and indirects) were classified according to achieved drift reduction percentages (ISO 22369-1:2013) and compared. Indirect methods discriminated DPVs from different nozzles (conventional, air induction) and fan airflow rate (high, low) combinations. Indirect methods also showed that despite crop influence on drift amount, target absence has a negligible effect when used specifically for DRP determination/classification. In fact, identical DRP final classifications were achieved for the two methodologies tested. Alternatively, all tested configurations resulted in lower DR values following the ISO 22866 field method, which caused different final classifications due to the high dependence of results on external factors. The alternative test bench methodology, characterized by the absence of target crop and calm of wind, was considered feasible for comparative measurements of airblast sprayer DRP. © 2019 Society of Chemical Industry.

Development of a Device to Pulping Fruits of Bocaiuva (Acrocomia aculeate sp.): Intended for the Communities that Practice Sustainable Agriculture or Strativism

Bocaiuva (Acrocomia aculeata) fruit pulp has high potential for food, pharmaceutical and cosmetic applications and in the biofuel industry, however, the main hindrance for these applications is the availability of pulp in sufficient quantity. The pulp of this fruit is usually supplied by rural communities where the processors use manual pulping, which is not only time-consuming but yields product of low quality. Therefore, the objective of this work was to design, fabricate and evaluate the efficiency of an experimental bench device for pulping bocaiuva fruits. The bench device was designed to be compact and easy to operate, consisting of three units (processing, secondary, and peripheral) with intermittent operation and pulping performed by shearing. The performance evaluation of the machine was carried out with fruit dehydrated at 70 ºC and different times of dehydration (6, 12 and 24 hours). The pulp weight was evaluated every 15 seconds during the pulping process period (150 seconds). The highest pulping efficiency (96%) was obtained with fruits that were dehydrated for 24 hours, with a 120-second pulping, which resulted in a production rate of 5.5 kg h-1 This high efficiency makes this mechanized prototype effective for pulping bocaiuva fruits and, thus, it can replace manual pulping, especially in rural communities involved with the bocaiuva production chain.

Evaluating the cutting efficiency of NiTi instruments with reciprocating motions

Aim: This study tested a setup for in vitro experimental analysis of axial forces and torque during the preparation of artificial canals using nickel-titanium reciprocating endodontic files. Methods: The cutting efficiency of Reciproc (RC) and WaveOne (WO) reciprocating size 25/.08 instruments (n = 10) was evaluated, taking into account their dimensional and geometrical features. Measurements of the diameter at each millimeter from the tip, pitch length, helical angle, and cross-sectional design and area were assessed. Cutting efficiency tests were carried out on a specific bench device by measuring the torque and axial force required during artificial canal shaping. Statistical analysis was performed using one-way ANOVA (α = 0.05). Results: The WO samples showed larger A3 mean values than did the RC instruments (P <.0001), despite having equal diameters at 3mm from the tip (D3) (P = .521). The mean values of pitch length were higher for RC than for WO instruments (P <.0001), with consequently smaller helical angles (P <.0001). For the cutting efficiency tests, the required torque was lower for the RC group when compared to the WO group, but it was significant only in the first stage of insertion in the artificial canals (P = .008). Regarding the apical force, the RC instruments reached higher values when compared to the WO instruments (P = .04) in the second stage of cutting action. Conclusion: Reciproc instruments demonstrated statistically higher cutting efficiency when compared to WaveOne instruments.Uniterms: cutting efficiency; M-Wire; reciprocating motion; Reciproc; WaveOne

Development of a Device to Pulping Fruits of Bocaiuva (Acrocomia aculeate sp.) for the Communities that Practice Sustainable Strativism

Bocaiuva (Acrocomia aculeata) fruit pulp has high potential for food, pharmaceutical and cosmetic applications and in the biofuel industry. The main hindrance for these applications is the availability of pulp in sufficient quantity. The pulp of this fruit is usually supplied by rural communities where the processors use manual pulping, which is not only time-consuming but yields product of low quality. The objective of this work was to design, fabricate and evaluate the efficiency of an experimental bench device for pulping bocaiuva fruits. The bench device was designed to be compact and easy to operate, with intermittent operation and pulping performed by shearing. The performance evaluation of the machine was carried out with fruit dehydrated at 70°C and different times of dehydration (6, 12 and 24 hours). The pulp weight was evaluated every 15 seconds during the pulping process period (150 seconds). The highest pulping efficiency (96%) was obtained with fruits that were dehydrated for 24 hours, with a 120-second pulping, which resulted in a production rate of 5.5 kg h-1 This high efficiency makes this mechanized prototype effective for pulping bocaiuva fruits and, thus, it can replace manual pulping, especially in rural communities involved with the bocaiuva production chain.

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Introduction: Tracheostomy tube manometry allows objective evaluation of intra-tracheal pressures during the use of a speaking valve. The use of tracheal manometry promptly identifies which patients may or may not tolerate the use of a speaking valve or capping when assessing for decannulation. Currently tracheostomy manometry is done with a variety of non-disposable airway pressure measuring devices. With the current devices, clinicians and/or departments using these non-disposable devices must purchase, clean, maintain, and protect them for prolonged use. The disposable manometer is easily assembled using a disposable pressure manometer (Ambu Inc.), a disposable swivel connector (Covidien, Inc.,) and a 15mm ID connector with pressure sample port to simulate commercial manometers. Use of the inexpensive disposable manometer has the potential to eliminate cost and maintenance barriers to routine tracheal manometry. Hypothesis: We hypothesize that a tracheal manometry device constructed using a disposable airway pressure manometer is as accurate as a commercially available non-disposable manometer. Methods: The purpose of our study was to first determine the initial accuracy of 60 AMBU disposable airway manometers. The AMBU disposable airway manometers were compared to a commercially available non-disposable manometer used in respiratory care (Rusch). Then the disposable and non-disposable manometers were compared to a certified calibrating manometer (FlukeCalibrating Manometer). Results: When all samples were compared, there were no differences in either the AMBU disposable airway pressure manometer or the Rusch airway pressure manometer when compared to the Fluke calibrating manometer. A Pearson product-moment correlation coefficient was computed with SPSS Version 12 (Chicago, IL) to assess the relationship between the current assessment tool (Rusch) to the disposable device (Ambu) and the bench device (Fluke) to assess manometry. There was a strong positive correlation between all of the variables (r=.997, n= 178, p =.000). Conclusions: A disposable manometer costing as little as 10% of commercial manometers is clinically accurate and maintains accuracy through up to 50 simulated clinical uses.

Influence of multiple clinical use on fatigue resistance of ProTaper rotary nickel‐titanium instruments

To examine the influence of clinical use on the occurrence of deformation and fracture and on the fatigue resistance of ProTaper rotary instruments. Root canal treatments were performed on patients using the ProTaper rotary system. Ten sets of instruments were used by an experienced endodontist, each set in five molars. Another 10 sets of instruments were used by the same operator, each set in eight molars. In addition, 10 sets of instruments were used, each set in five molars, by undergraduate students with no clinical experience with the system. After clinical use, S1, S2, F1 and F2 instruments were analysed for damage by optical and scanning electron microscopy. The used sets, along with a control group of 12 sets of new instruments, were then tested in a bench device for fatigue resistance. The use of the ProTaper rotary instruments by an experienced endodontist allowed for the cleaning and shaping of the root canal system of up to eight molars without fracture. During the students work, six instruments fractured. Fatigue resistance decreased upon clinical use for all instruments analysed. Fatigue resistance of used instruments was reduced, but no significant change was observed amongst the instruments used for shaping the canals of five and eight molars. Operator experience affected the occurrence of fracture and plastic deformation during shaping.

Radiographic determination of canal length: Direct digital radiography versus conventional radiography

This research compared the length determination images produced by Trophy and Regam direct digital radiographic systems with conventional E-speed radiographs. Size #15 K files were placed in the canals of 19 teeth of cadaver specimens and radiographed in a geometrically standardized bench device. Three evaluators estimated the length adjustment necessary to position the file at the apex. The mean estimated adjustment lengths were compared with the true, anatomically determined adjustment lengths. Statistical analysis with analysis of variance and the Student-Newman-Keuls test indicated no significant difference between direct digital thermal print images and conventional radiographs (p > 0.10). Length adjustment estimates with conventional radiographs were significantly more accurate than Regam high-resolution computer monitor images (p < 0.01). Additionally, it was determined that length adjustment estimates were significantly more accurate when the file was placed short of the apex (p < 0.001). The clinical relevance of these differences is discussed.

1347 STATISTICAL DOCUMENTATION THAT CONTINUOUS OXYGEN MONITORING IMPROVES PATIENT CARE

In a prospective controlled study, we used the Oximetrix(R) catheter oximeter in preterm infants with cardiopulmonary disease to determine if continuous measurement of arterial oxygenation offers any significant clinical advantages over conventional intermittent monitoring. Eleven study and 11 control infants were matched for gestational age, weight, hematocrit and similarity of disease. The mortality rate, need for a ventilator and the time in an FiO2 >.40 or >.70 were similar in both groups. The simultaneous measurement of saturation by the catheter oximeter and the Radiometer OSM2 bench device was compared. The correlation coefficent of 1039 data pairs was .97. In-vivo calibration was required in 60% of catheters in use 40 hours. The time before the first calibration was 18.3 ± 10.6 hours (mean ± S.D.). During the first 72 hours, 51% more blood samples for gas analysis were withdrawn from the control group (p=.012) and the number of blood samples obtained per hour during the catheter's lifetime was greater (p=.026). More blood transfusions were needed in the control group (p=.019). The PaO2 was greater than 100 mmHg 18.6% (control) and 8.4% (study) of the total hours the catheters were used for monitoring (p=.026). This study shows statistically significant evidence that the continuous measurement of arterial oxygenation using the Oximetrix(R) oximeter improves the management of infants with cardiopulmonary disease.