Range Of Power Settings Research Articles

Computational investigation of quiet propeller designs for small unmanned aerial vehicles

The noise produced by the propellers of micro Unmanned Air Vehicles (UAVs) could be counterproductive to their mission, since adversaries can often hear them from a distance. This study investigates new quiet propeller designs that have different twist angle distributions that vary the lift generated along the span of the propeller blade to reduce the thrust loading near the tip. In addition, nine co-rotating dual propellers with different phase angle and spacing are considered. All propellers were tested at the USAFA subsonic wind tunnel at an assumed UAV cruise velocity of 44 ft/s while measuring thrust, torque, sound pressure level, and rotational speed over a range of power settings. These propellers are modeled using the DoD HPCMP CREATETM-AV Kestrel simulation tools. The thrust and torque were extracted from these simulations and compared with experimental data. Pressure tap points were defined one inch behind the propeller. The instantaneous pressure data were measured at these locations for 20 spinning cycles. Sound pressure level values were then estimated from these data. Predictions are then compared with experimental data measured from a traversing microphone.

MP07-17 STONE ABLATION EFFICACY OF A NEW PROTOTYPE HOLMIUM:YAG PULSE-MODULATED LASER AT WORKING DISTANCES OF UP TO 3 mm

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology (MP07)1 Sep 2021MP07-17 STONE ABLATION EFFICACY OF A NEW PROTOTYPE HOLMIUM:YAG PULSE-MODULATED LASER AT WORKING DISTANCES OF UP TO 3 mm Bingyuan Yang, Isha Parab, Jasmine Cancino, Sanwei Liu, Aditi Ray, Thomas Hasenberg, Tim Harrah, and Ben Turney Bingyuan YangBingyuan Yang More articles by this author , Isha ParabIsha Parab More articles by this author , Jasmine CancinoJasmine Cancino More articles by this author , Sanwei LiuSanwei Liu More articles by this author , Aditi RayAditi Ray More articles by this author , Thomas HasenbergThomas Hasenberg More articles by this author , Tim HarrahTim Harrah More articles by this author , and Ben TurneyBen Turney More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001980.17AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Holmium:YAG laser has been the lithotrite of choice for around 30 years in kidney stone surgery. The relatively high absorption in water is clinically useful but also limits the effective range of these lasers. Laser technology has taken advantage of the “Moses effect” to improve energy delivery to the target while reducing heating of the irrigation fluid. We report on a new prototype Holmium laser that fires multiple micro-pulses in pulse packets and present stone phantom ablation rate results at fiber-to-stone working distances of up to 3mm utilizing a bench model. METHODS: Uniform, homogeneous BegoStones (15:3 BegoStone:water) were used. A 242mm core fiber was attached to the prototype laser and the fiber was moved over the surface of the stone in a predetermined pattern using an automated system. A range of pulse packet energy/frequency settings from 20 W to 45 W were investigated. Stone ablation efficiency was measured by dry-weight difference before and after treatment. A range of working distances (WDs) from 0.5 mm to 3 mm were used to investigate the effect of increased distance to the stone. RESULTS: Measurable ablation rates were observed with the prototype pulse-modulated laser up to a working distance of 3 mm, across a range of powers (figure 1). The ablation rate at 3 mm WD was 27.6% of that at 0.5 mm WD (range 12.9-44.4%). Results from a reference holmium laser using the same methodology are also included. CONCLUSIONS: The prototype laser demonstrated an impressive working range in our bench testing across a range of power settings, with measurable ablation even at a WD of 3 mm. This suggests that these micro-pulses produce a significant Moses effect. We feel that pulse-modulation with packets of micro-pulses can synergise well with the Moses effect to increase the effective range and needs to be further tested in a clinical setting. (Disclaimer: Concept device or technology. Not available for sale). Source of Funding: Boston Scientific Corp © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e146-e146 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Bingyuan Yang More articles by this author Isha Parab More articles by this author Jasmine Cancino More articles by this author Sanwei Liu More articles by this author Aditi Ray More articles by this author Thomas Hasenberg More articles by this author Tim Harrah More articles by this author Ben Turney More articles by this author Expand All Advertisement Loading ...

Design of an Impedance-Controlled Hot Snare Polypectomy Device.

This paper goes through the process of first designing a feedback system that allows for the measuring of impedance while using the hot snare polypectomy method. The electrosurgical unit used in this study was the Olympus PSD-30. After the impedance-controlled feedback system was completed, the device was tested under a range of power settings from 10 W–50 W. The test was performed ex vivo using porcine colon samples. Using the information gathered from these tests, a technique of determining the threshold of perforation and implementing a system to automatically stop the applied current from the PSD-30 was developed. The data showed that after an increase in impedance of 25% from that of the initially measured impedance, perforation ensued in the tissue samples. Using this information, the device was programmed to interrupt the PSD-30 at this threshold point. This final design was tested and proved able to automatically prevent the event of perforation from occurring, resulting in the ability to prevent serious complications.

Adaptive Polynomial Chaos for Gas Turbine Compression Systems Performance Analysis

The design of a gas turbine, or one of its constituentmodules, is generally approachedwith some specific operating condition in mind (its design point). Unfortunately, engine components seldom exactly meet their specifications and do not operate at just one condition, but over a range of power settings. This simplification can then lead to a product that exhibits performance worse than nominal in real-world conditions. The integration of some consideration of robustness as an active part of the design process can allow products less sensitive to the presence of the noise factors commonly found in real-world environments to be obtained. To become routinely used as a design tool, minimization of the time required for robustness analysis is paramount. In this study, a nonintrusive polynomial chaos formulation is used to evaluate the variability in the performance of a genericmodular-core compression system for a three-spool modern gas turbine engine subject to uncertain operating conditions with a defined probability density function. The standard orthogonal polynomials from the Askey scheme are replaced by a set of orthonormal polynomials calculated relative to the specific probability density function, improving the convergence of the method.

Second‐generation argon plasma coagulation: Two‐center experience with 600 patients

Second-generation argon plasma coagulation (APC; APC 2/VIO APC) with its modes 'forced', 'pulsed', and 'precise' is a further development of the ICC/APC 300 system (first-generation APC). Until now, only limited data has existed on the use of APC 2. Fundamental data on the characteristics of the various APC 2 modes and clinical data from more than 600 patients treated in two high-volume endoscopy centers were analyzed. On the basis of these data, recommendations for the use of APC in daily gastroenterological practice were made. In comparison to the ICC system, second-generation APC offers a broadened bandwidth of settings including different APC modes and a range of power settings from 1 to 120 W. Using the various modes of APC 2 in a variety of gastrointestinal diseases, minor complications were observed in 9-21% of patients. Major complications occurred in 1-7% of patients. In a two-center experience treating a large group of patients with a wide variety of gastrointestinal conditions, the different APC 2 modes appeared to be safe and effective. Certain preventive measures before and during clinical application are recommended in order to avoid complications.

Joining characteristics of β-titanium wires with electrical resistance welding

The goal of this research was to investigate the effects of different conditions for electrical resistance welding of beta-titanium orthodontic wires. Three electrode types were used with a range of power settings on an electrical resistance welding machine to join beta-titanium wires (Resolve, GAC International). Forces that caused bond failures for joined specimens were obtained with tensile loading, and the values were compared using one-way ANOVA and the Tukey test (alpha = 0.05). Metallurgical phases in the joint region were determined by micro-X-ray diffraction. Mean tensile forces for bond failure ranged from 5 to 20 kgf for the eight specimen groups and were dependent on electrode type and power setting. All X-ray diffraction peaks in the joint region were indexed to beta-titanium. Superior bond strength was achieved with the use of wide electrodes. The absence of phases other than beta-titanium in the joint area suggests that the electrical resistance welding may not adversely affect clinically important mechanical properties. Scanning microscope observations indicated that the localized permanent deformation and the formation of an undesirable equiaxed grain structure occurred with the use of narrow electrodes.

Performance of Ultrasonic Retrograde Systems

The aim of this study was to evaluate variations in power output of different Piezon-Master 400 (Electro Medical Systems, Nyon, Switzerland) ultrasonically driven generators and analytic handpieces at a range of power settings. A scanning laser vibrometer was used to measure the maximum vibration displacement amplitude of a KiS 2D tip. Ten repeat scans were made of the unloaded tip oscillation at six power settings. Data were acquired from four different generators and handpieces. Linear trend lines fitted to all tip data showed that none of the generator/handpiece combinations produced a linear increase in tip displacement amplitude with increasing power setting. A univariate analysis of variance (general linear model) showed that generator, handpiece, and power were all significant variables (p<0.0001). This study showed that there is significant variability in the power output between generators, and not all Analytic handpieces performed consistently when compared with each other.

Contrail Formation and Propulsion Efficiency

The contrail factor is the ratio of water vapor to enthalpy added by combustion to the exhaust plume from an aircraft engine. It is the key parameter determining the highest temperature at which contrails will form behind a particular engine on a particular aircraft. Cycle calculations are used to estimate contrail factors for a range of e ight environments at a range of power settings, for generic low-bypass and high-bypass turbofan gas-turbine engines. It is found that, contrary to assumptions made in current methods of contrail forecasting, the contrail factor is not constant for a given engine type. The contrail factor varies even forthe same engine at different power settings and e ight conditions. Results are shown for a range of conditions, including e ight levels between 25,000 and 50,000 ft in a standard atmosphere, e ight Mach numbers ranging from 0.4 to 0.9, and powersettings from idle (low) to military (high). The computed contrail factors range from 0.030 to 0.053 g¢ kg i 1±± C i 1 for the low-bypass engine and from 0.038 to 0.090 g¢ kg i 1± C i 1 for the high-bypass engine. Changes in contrail factor can be roughly related to changes in the threshold environmental temperature for contrail formation by the relationship that a 10% increase in contrail factor results in a 1 ± C higher threshold temperature in a typical upper tropospheric environment for threshold temperatures near i 50 ±± C. These calculations do not yield precise estimates of contrail factors for specie c engines, but demonstrate that contrail factors for a given engine are generally higher at lower power settings at a given Mach number, higher at higher Mach numbers at a given power setting, and higher at higher altitudes in general.

Ablation of Metastatic Ovarian Carcinoma with the Argon Beam Coagulator: Pathologic Analysis of Tumor Destruction

Objective. The aim of this study was to characterize the histopathologic effects of electrosurgical tumor destruction of metastatic ovarian carcinoma using the argon beam coagulator (ABC) and evaluate the depth of tissue damage produced by a range of power settings and tissue interaction times.Methods. Epithelial ovarian carcinoma tumor specimens (1 cm3) were harvested intraoperatively. Following surgical excision, electrosurgical destruction of tumor was effected using the ABC at three power settings (60, 80, and 100 W) and three tissue interaction time intervals (1, 3, and 5 s), yielding nine experimental groups of 16 samples each (n = 144). Samples were formalin-fixed, cross-sectioned, stained with hematoxylin and eosin, and examined microscopically for histologic characteristics and depth of tissue destruction.Results. Microscopic evaluation revealed that the total depth of destruction (TDD) produced by the ABC was composed of three distinct zones of tissue injury: vaporization, carbonized eschar (ESC), and coagulative necrosis (NEC). For each power setting, the mean TDD increased in a linear fashion as the interaction time interval increased from 1 to 5 s (60 W, 1.71 to 2.43 mm; 80 W, 2.24 to 3.69 mm; 100 W, 3.21 to 5.58 mm). By regression analysis, both power setting and tissue interaction time were independently associated with increasing TDD, with power having the strongest effect. At all power settings and interaction time intervals, the incremental change in TDD was primarily a function of the degree of tissue vaporization, which increased from 0.59 mm at 60 W (1 s) to 3.22 mm at 100 W (5 s). For all experimental groups, the ratio of NEC/ESC was highly consistent, ranging from 1.03 to 1.33 (P > 0.05, Bonferroni multiple comparisons procedure), and demonstrated that for each resulting ESC, an equivalent or greater degree of underlying NEC was also present.Conclusions. The destruction of ovarian carcinoma tumor tissue produced by the ABC is dependent upon both power setting and tissue interaction time. Increasing depth of destruction is due predominantly to a deeper level of tissue vaporization. The NEC/ESC ratio provides a reliable means of estimating the true depth of tumor destruction produced by the ABC and may contribute to increased safety and efficacy of electrosurgical cytoreduction of using this technique.

A laser-based method for measuring thermal nociception of cattle

We describe a method for measuring nociception in cattle using a CO 2 laser aimed at the caudal aspect of the metatarsi. In Experiment 1, infrared thermography showed that calves responded by lifting their legs when skin temperatures reached 45–55°C. In Experiment 2a, the validity of the method was tested by comparing the response latencies of 14 calves to two power settings (2.25 W vs. 4.5 W) with each setting being applied six times. We found that both leg-lift latencies and tail-flick latencies were lower at the higher power setting, and the calves were more likely to respond by kicking than by simply moving the leg. The standard deviations between and within calves were smaller at the higher power setting, and the large within-calf variation means that at least three tests were required to obtain reliable measures that could differentiate between calves. In Experiment 2b, application of the laser at a range of power settings (2.0, 3.0, 4.0, 4.5, 5.0 and 5.5 W) on 16 calves showed that response latencies decreased as power increased up to 4.5 W, after which no further change occurred. In Experiment 3, the repeatability of the method was evaluated on nine measures with the high power setting (4.5 W). The coefficient of variation associated with repetition of the measures was 36%. In general, we found little change in response latencies with repeated use of the laser, except that responses on the second test tended to be shorter. Experiment 4 showed that ambient temperatures between 16°C and 27°C did not affect response latencies, but these were longer at temperatures of 7°C. We suggest that the method is a useful way of measuring cattle's sensitivity to nociception as the animals need not be restrained and the distance to the animal need not be closely controlled. However, to obtain accurate, valid and reliable measures it is necessary to use a high power setting (4.5 W) and take at least three consecutive measures of the response latency.

Cutting ability of an ultrasonic retrograde cavity preparation instrument.

The aim of this study was to investigate the cutting ability of a working ultrasonic instrument designed for surgical endodontic use (Neosonic, Amadent Corp, Cherry Hill, NJ, USA). Three designs of tip, designated CT 1 to CT 3 were calibrated by measuring their displacement amplitudes in air using light microscopy over a range of power settings. Extracted teeth were sectioned longitudinally and polished to produce a smooth dentine surface onto which the tips were applied for 1 minute over the above range of power settings at a load of approximately 20 g. The depth of cut in the dentine surface was measured using a two dimensional surface profilometry technique. Results showed that a raising of the power setting produced an increase in displacement amplitude and cutting ability for all tip designs. This increase was linear, with minimal cutting occurring at lower power settings. In conclusion the ultrasonic tips could be successfully used to remove dentine, and medium to high power settings optimised their efficiency.

Comparative Evaluation of Hyperthermia Heating Modalities: I. Numerical Analysis of Thermal Dosimetry Bracketing Cases

A method for comparing the relative abilities of different hyperthermia heating modalities to properly heat tumors has been developed using solutions of the bio-heat transfer equation. A single measure, the range of absorbed powers that gives acceptable tissue temperature distributions, is used to characterize the ability of a given heating technique to heat a given tumor. An acceptable tissue temperature distribution is one for which (a) the temperatures in the coolest regions of the tumor are above a minimum therapeutic value, (b) the temperatures in the hottest regions of the tumor do not exceed a maximum clinically acceptable value, and (c) the normal tissue temperatures do not exceed maximum clinically acceptable levels. This measure can be interpreted directly in clinical terms as the range of power settings on the power indicator of a heating device for which acceptable tumor heatings will occur. This paper describes the basis of the method and investigates the role of tumor blood perfusion patterns in determining the size of the acceptable power range. Three tumor perfusion patterns are investigated: uniform tumor perfusion, a concentric annulli perfusion model in which the tumor consists of a necrotic core surrounded by two concentric layers of increased perfusion, and a random perfusion distribution model. The results show that, in general, the uniform and annular perfusion models serve as bracketing case patterns. That is, they give acceptable power range values that are upper and lower limits of the acceptable power ranges obtained for the random perfusion patterns. The method is applied to heating patterns that simulate those obtained from a variety of different available heating techniques, and it is found to be valid for all cases studied. The role of normal tissue limiting conditions is also investigated.