Academic literature on the topic 'VT instrument'
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Journal articles on the topic "VT instrument"
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Cook, I. "Pedometer step counting in South Africa: tools or trinkets?" South African Journal of Sports Medicine 18, no. 3 (February 5, 2006): 67. http://dx.doi.org/10.17159/2078-516x/2006/v18i3a238.
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Objectives. This study addressed (i) the accuracy of measuring ambulatory signals and (ii) the susceptibility to nonambulatory signals, of the Discovery Vitality Pedometer (VT) and the Kellogg's Special K Step Counter (KL) compared with three research-grade pedometers (DW: Yamax DigiWalker SW-401, MTI: MTI Actigraph AM-7164-2.2 , NL: New Lifestyles NL 2000). Design. One hundred instruments (20 instruments/brand) were tested at five level walking speeds on a motorised treadmill (3.24, 4.02, 4.80, 5.64, 6.42 km.hr-1) and during motor vehicle travel on tarred roads (62.9 km). Results. The KL was highly variable across all speeds, while the VT tended to be variable at the lowest speed. The DW, NL and VT significantly underestimated steps below 4.80km.hr-1 (41 - 94%, p < 0.02) but accuracy improved at speeds ≥ 4.80 km.hr-1 (98 - 102%). The KL displayed the highest variability (60% inter-instrument variance) followed by the VT (10% inter-instrument variance). The research-grade pedometers were the least variable (0 - 1% inter-instrument variance). At 4.80 km.hr-1, all research- grade pedometers measured within a 10% margin of error compared with the 90% of VT units and 42% of KL units. The VT was significantly more resistant to nonambulatory signals than the DW (p < 0.01). The KL was the most variable in its response to non-ambulatory signals while the NL was the most consistent. The MTI detected the most non-ambulatory signals (p < 0.05). Conclusions. The KL should not be used as a promotional pedometer. The VT achieved the minimum standards required of a promotional pedometer. Further testing is required for longevity, and performance under free-living conditions. South African Journal of Sports Medicine Vol. 18 (3) 2006: pp. 67-78
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Cook, I. "Pedometer step counting in South Africa: tools or trinkets?" South African Journal of Sports Medicine 18, no. 3 (February 5, 2009): 67. http://dx.doi.org/10.17159/2413-3108/2006/v18i3a238.
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Objectives. This study addressed (i) the accuracy of measuring ambulatory signals and (ii) the susceptibility to nonambulatory signals, of the Discovery Vitality Pedometer (VT) and the Kellogg's Special K Step Counter (KL) compared with three research-grade pedometers (DW: Yamax DigiWalker SW-401, MTI: MTI Actigraph AM-7164-2.2 , NL: New Lifestyles NL 2000). Design. One hundred instruments (20 instruments/brand) were tested at five level walking speeds on a motorised treadmill (3.24, 4.02, 4.80, 5.64, 6.42 km.hr-1) and during motor vehicle travel on tarred roads (62.9 km). Results. The KL was highly variable across all speeds, while the VT tended to be variable at the lowest speed. The DW, NL and VT significantly underestimated steps below 4.80km.hr-1 (41 - 94%, p < 0.02) but accuracy improved at speeds ≥ 4.80 km.hr-1 (98 - 102%). The KL displayed the highest variability (60% inter-instrument variance) followed by the VT (10% inter-instrument variance). The research-grade pedometers were the least variable (0 - 1% inter-instrument variance). At 4.80 km.hr-1, all research- grade pedometers measured within a 10% margin of error compared with the 90% of VT units and 42% of KL units. The VT was significantly more resistant to nonambulatory signals than the DW (p < 0.01). The KL was the most variable in its response to non-ambulatory signals while the NL was the most consistent. The MTI detected the most non-ambulatory signals (p < 0.05). Conclusions. The KL should not be used as a promotional pedometer. The VT achieved the minimum standards required of a promotional pedometer. Further testing is required for longevity, and performance under free-living conditions. South African Journal of Sports Medicine Vol. 18 (3) 2006: pp. 67-78
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Acharya, Nisha, Md Riasat Hasan, Dashrath Kafle, Anil Chakradhar, and Takashi Saito. "Effect of Hand and Rotary Instruments on the Fracture Resistance of Teeth: An In Vitro Study." Dentistry Journal 8, no. 2 (April 29, 2020): 38. http://dx.doi.org/10.3390/dj8020038.
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Objective: Endodontic treatment should be both conservative and effective. Endodontic instruments with a greater taper are used for coronal flaring, for proper debridement with efficient irrigation. However, increased taper of an instrument can remove a larger amount of pericervical dentin, compromising the strength of the tooth. The aim of this study was to determine the effect of hand files, ProTaper Universal, ProTaper Next, and V Taper rotary instrument systems on the fracture resistance of teeth. Materials and Methods: In total, 60 extracted human maxillary first premolars were divided into four groups—Group I (Hand Files; HF), Group II (ProTaper Universal; PT), group III (ProTaper Next; PTN) and Group IV (V Taper; VT) (N = 15). Each group was instrumented with the respective instrument system, irrigated, obturated, restored, and mounted in cold cure acrylic. A universal load-testing machine (Shimadzu, Japan) was used to apply a vertical compressive load. The maximum force was recorded in Newton. Analysis of variance (ANOVA) and Independent t-tests were applied to compare the maximum mean force required to fracture the tooth. Results: There was a statistically significant difference in fracture resistance between Group I (HF) and Group II (PT) and between Group II (PT) and Group IV (VT) (p < 0.001). Similarly, a significant difference was observed between Group II (PT) and Group III (PTN) (p < 0.01). Furthermore, a significant difference was observed between Group I (HF) and Group III (PTN), and between Group III (PTN) and Group IV (VT) (p < 0.05), too. However, there was no statistically significant difference between Group I (HF) and group IV (VT) (p > 0.05). Conclusion: Rotary files with more taper seem to remove more pericervical dentin than traditional manual and rotary files with less taper, thus altering the strength of the tooth.
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Wu, C., Y. L. Qiu, and H. B. Cai. "SVOM Visible Telescope: Performance and Data Process Scheme." Proceedings of the International Astronomical Union 7, S279 (April 2011): 421–22. http://dx.doi.org/10.1017/s1743921312013646.
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AbstractVT (Visible Telescope) is an instrument onboard SVOM (Space-based multi-band astronomical Variable Objects Monitor) satellite working in the visible band, which will play an important role in follow-up of two categories of GRBs: very distant events at higher redshift and faint/soft nearby events in SVOM mission. To fulfill these primary science requirements, decent sensitivity and wavelength coverage are fundamental for VT design. VT performance and data process strategy were successfully studied on its feasibility in Phase A, which is presented in this poster. Additionally, preliminary VT image simulator is also introduced here.
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Newby, Maxwell D., Habib G. Zalzal, Jad Ramadan, Brian M. Kellermeyer, and Michele M. Carr. "Decision Quality Among Parents Who Are Offered Ventilation Tube Insertion for Their Children." Annals of Otology, Rhinology & Laryngology 129, no. 8 (March 4, 2020): 748–54. http://dx.doi.org/10.1177/0003489420909850.
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Objective: To develop a Decision Quality (DQ) tool to measure parents’ DQ concerning ventilation tube (VT) insertion in their children. Method: Parental survey during 2017 to 2018 in a tertiary care pediatric otolaryngology clinic comparing a validated Decisional Conflict (DC) scale with a DQ instrument including Shared Decision-Making (SDM) scale, parental treatment goals, and knowledge about VT. Results: Of 100 parent participants, 83% were mothers and 14% were fathers. 94% elected VT insertion, 6% elected monitoring or deferred the decision. 44% of the patients were <18 months, 42% were 19 months to 3 years, and the rest were older. The mean DC score was 8.26 out of 100 (95% CI 4.82-11.69), indicating low DC. Mean DQ score was 82.45 out of 100 (95% CI 80.18-84.72), including mean SDM of 87.71 (95% CI 83.53-91.88,), mean knowledge score of 87.5% (95% CI 84.56-91.59) and mean values score of 7.16 (95% CI 6.90-7.41). Comparisons between those who elected VT and those who did not showed that electors had lower DC scores (7.15 vs 24.74, P < .001), higher DQ scores (83.00 vs 72.61, P = .028) with higher SDM scores (88.70 vs 70.22, P = .044) and higher values score (7.20 vs 6.36, P = .034). Cronbach alpha for the DQ scale was 0.76. Spearman’s rho for DQ score versus DC score was −0.458, P < .001. Conclusions: DQ, as measured with this tool, was higher when parents chose to place tubes. Our DQ instrument has potential use for study of why parents may decline VT when their child meets criteria for them.
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Hastings, R. H., and F. L. Powell. "High-frequency ventilation of ducks and geese." Journal of Applied Physiology 63, no. 1 (July 1, 1987): 413–17. http://dx.doi.org/10.1152/jappl.1987.63.1.413.
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We studied gas exchange in anesthetized ducks and geese artificially ventilated at normal tidal volumes (VT) and respiratory frequencies (fR) with a Harvard respirator (control ventilation, CV) or at low VT-high fR using an oscillating pump across a bias flow with mean airway opening pressure regulated at 0 cmH2O (high-frequency ventilation, HFV). VT was normalized to anatomic plus instrument dead space (VT/VD) for analysis. Arterial PCO2 was maintained at or below CV levels by HFV with VT/VD less than 0.5 and fR = 9 and 12 s-1 but not at fR = 6 s-1. For 0.4 less than or equal to VT/VD less than or equal to 0.85 and 3 s-1. less than or equal to fR less than or equal to 12 s-1, increased VT/VD was twice as effective as increased fR at decreasing arterial PCO2, consistent with oscillatory dispersion in a branching network being an important gas transport mechanism in birds on HFV. Ventilation of proximal exchange units with fresh gas due to laminar flow is not the necessary mechanism supporting gas exchange in HFV, since exchange could be maintained with VT/VD less than 0.5. Interclavicular and posterior thoracic air sac ventilation measured by helium washout did not change as much as expired minute ventilation during HFV. PCO2 was equal in both air sacs during HFV. These results could be explained by alterations in aerodynamic valving and flow patterns with HFV. Ventilation-perfusion distributions measured by the multiple inert gas elimination technique show increased inhomogeneity with HFV. Elimination of soluble gases was also enhanced in HFV as reported for mammals.(ABSTRACT TRUNCATED AT 250 WORDS)
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Török, P., F. Depta, V. Donic, M. Nosál’, S. Imrecze, J. Benová, K. Galková, et al. "Volumetric Сapnography As a Tool for Evaluation of Alveolar Ventilation Effectiveness in Clinical Practice." General Reanimatology 14, no. 5 (October 28, 2018): 16–24. http://dx.doi.org/10.15360/1813-9779-2018-5-16-24.
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The purpose of the study was to compare the relationship between the dead space volume and tidal volume (VD/VT) using volumetric capnography (VCap) during pressure controlled (PCV) and pressure supported (PSV) ventilation mode in the postoperative period.Materials and methods. 30 randomly assigned cardiac surgical patients undergoing CABG (coronary artery bypass grafting) using ECC (extracorporeal circuit) were included in an observational, prospective study. Patients were connected to the ventilator immediately after ICU admission. After that, monitoring VD/VT, CO2 production (VECO2) as well as ventilation parameters was carried out. The parameters during PCV and PSV mode were statistically evaluated using t-test.Results. Expiratory CO2 (ETCO2) concentration were not significantly different in both PCV or PSV (p=NS), although both VECO2 and minute ventilation (MV) increased during PSV mode (p<0.01). VD/VT in PSV mode was lower than in PCV. Gas exchange represented by alveolar ventilation (VA) was better during PSV (p<0.01). VA was also higher during PSV (p<0.05). The calculated VD/VT ratio differed between PCV and PSV mode (p<0.01).Conclusion. VCap represents a tool for monitoring of CO2 exchange effectivness. We registered a decrease in VD/VT with improved alveolar ventilation (VA) in PSV mode. VCap seems to be a suitable instrument for adjustment of protective lung ventilation.
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Elyousfi, Fatima, Amitabh Anand, and Audrey Dalmasso. "Impact of e-leadership and team dynamics on virtual team performance in a public organization." International Journal of Public Sector Management 34, no. 5 (March 26, 2021): 508–28. http://dx.doi.org/10.1108/ijpsm-08-2020-0218.
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PurposeThis study examines the effect of various attributes of leadership and teams, modeled as perceived e-leadership and perceived team dynamics on virtual team (VT) performance in a public organization.Design/methodology/approachUsing a survey instrument, data were collected from 184 participants involved in a virtual workplace from one of the largest Canadian public organizations. This study uses PLS-SEM software and quantitative methods.FindingsThis research identified that perceived team dynamics, which includes team member behavior, collaboration and support, has a significant medium effect on VT member performance. However, perceived e-leadership, which includes leaders' trust, leader communication/co-ordination and leader behavior, has a significant small effect on VT performance.Originality/valueThis study contribute to literature on VTs and VT's performance specially in public organizations. As the existing literature on employee performance has mainly focused on private organizations, and more so on VTs. However, little is known about VTs in public organizations and specifically about their performance.
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Zhang, Chang Ming, and Xiao Li Su. "Multiple-Instrument Analysis and their Relationship with Process Development." Advanced Materials Research 699 (May 2013): 371–77. http://dx.doi.org/10.4028/www.scientific.net/amr.699.371.
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The waste polymer-polyethylene (PE) was treated in a supercritical water (SCW) system under different operation conditions (such as temperature, heat rate and ratio of water and PE material). The obtained liquid oil products and solid-products were analyzed by conjunct methods including high performance gel penetration chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and gas chromatography (GC). A relationship of the characteristics of the products and the operation conditions in waste treatment was established. The results of FTIR and GC analyses indicated that the liquid oil products contain a large amount of alkanes, which are suitable for using as fuel oil. Through a series of experiments, the optimum operation conditions were defined as follows：The amount of PE sample: 6g, H2O/PE ratio: 6/1, the reaction temperature (Tem): 460° C, heating rate (Vt): 7.66 (°C / second), the yield of products: 86.0%.
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Lei, Ming, Yue Guo, and Xin Zheng. "A Method for Measurement Traceability of Calibrator for Electronic Instrument Transformer Tester." Applied Mechanics and Materials 615 (August 2014): 201–7. http://dx.doi.org/10.4028/www.scientific.net/amm.615.201.
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The bottleneck of the measurement traceability system of electronic instrument transformer is the calibrator, which is based on the digital micro-differential source principle and plays the role as intermediate between digital values in data frames and the analog output of the existing standard current transformer (CT) or voltage transformer (VT). A kind of working mechanism of the calibrator for electronic instrument transformer tester and related calibration method are proposed in this paper. The ratio accuracy can be calibrated by the high-precision multimeter and the phase accuracy can be calibrated by the high-speed oscilloscope, which records the waveforms of analog output and the synchronization signal, and the time offset between them can be traced to the time standard. A calibrator is designed and manufactured according to the mechanism and related experiments are conducted to verify the feasibility of the calibration method.
Dissertations / Theses on the topic "VT instrument"
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Harmon, Kara L. "Stability of a Normal Heterosexual Female Response to Affinity 2.0." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/833.
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The purpose of the current study was to evaluate the temporal stability of a normal heterosexual female response to the Affinity 2.0, a newly standardized viewing time (VT) instrument that purports to measure sexual interest. Participants were 120 female undergraduate and graduate students from a private university (mean age = 21.67 years) who met inclusion criteria of non-pedophilic interest/history, identified as “Exclusively Heterosexual" on the Kinsey Scale, and who took the Affinity 2.0 both at test and at retest (approximately two weeks later). Participants also filled out a questionnaire following the retest composed of demographic questions, a shortened version of the Marlowe-Crowne Desirability Scale-10 [M-C 2(10)], and declared their sexual interest on the Kinsey Scale. Pearson correlation coefficients (PPMCC), Spearman's Rho correlation coefficients, and a Chi-Square Goodness of Fit Test were all utilized to assess the temporal stability of the sample's response to Affinity 2.0. All PPMCC and Spearman's Rho correlations for VT were statistically significant at the p < .01 level; while practical significance for PPMCC could only be considered moderate as best (range of r =.28 - .63), Spearman's Rho correlations (range of r =.41 - .65) were stronger and approached practical significance. The existence of an overall distinct and discernable VT response pattern was apparent as the sample demonstrated identical categorical VT preferences both test and retest. These results were consistent with results from previous VT studies (Quinsey, Rice, Grant & Reid, 1993; Wright & Adams, 1994; Quinsey, Ketsetzis, Earls, & Karamanoukian, 1996). In addition, this VT pattern was found to be stable from test to retest as assessed by a Chi-Square Goodness of Fit Test. An unexpected finding was the presence of elevated VT for adult and juvenile female images. Implications, limitations, and future studies are discussed.
Book chapters on the topic "VT instrument"
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Feuerle, Lois M. "Interpreting for Victims of Violence." In Handbook of Research on Medical Interpreting, 227–59. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-9308-9.ch010.
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Victims of violence and interpreters share one trait: they are susceptible to trauma-related sequelae. Direct victims may develop PTSD while interpreters may develop vicarious trauma. This chapter sets out the legal basis for language access in healthcare, noting the important quality dimension added by the ACA. It then reviews the statistics for various forms of violence and presents some of its enormous societal costs. It also highlights the similarity of some of the symptoms observed in persons suffering from vicarious trauma, PTSD and burnout, but notes the difference in the genesis of these three conditions. This is followed by an introduction to trauma-informed approaches in delivering victim services. Finally, it lays the basis for identifying VT symptoms, mentions two online instruments that might be useful in assessing the likelihood of vicarious trauma, and reviews types of self-care techniques for creating a personal self-care plan.
Conference papers on the topic "VT instrument"
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Glass, S. W., and R. F. Cole. "Inspection and Repair Technology for BMI Penetrations." In 12th International Conference on Nuclear Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/icone12-49478.
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Historically, United States (US) nuclear power plant inspections of the reactor vessel bottom-mounted-instrument (BMI) penetrations have been limited to visual verification via a combination of walk-downs and pressure tests. However in France, more than 18 UT and weld-surface VT campaigns had been performed to inspect the BMI penetration nozzles and welds since 1992 with no observed failures through 2002. In April 2003, South Texas Project Unit 1 discovered apparent leakage from two nozzles during a bare-metal examination. Based on the French inspection experience, Framatome ANP was selected for inspection and repair services to address the leaking nozzles. Inspection activities included ultrasonic examination (UT) of the tube, enhanced visual test (VT) and eddy current testing (ECT) of the J-groove weld, bobbin ECT and profilometry of the tube ID, helium leak test, phased-array UT, borescopic VT, and boat-sample removal with destructive metallurgical analysis. Repair activities included sealing the top portion of the penetration, cutting out the old nozzles, and welding in new nozzles. This presentation discusses BMI inspection and repair technology focused particularly on the South Texas Project experience.
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Mamat, Hazian, Yuzman Yusoff, Ismail Md Yusof, Walid Suradi, and Tan Kong Yew. "Characterization of temperature sensor using VT extractor circuit." In Instruments (ICEMI). IEEE, 2009. http://dx.doi.org/10.1109/icemi.2009.5274452.
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Thornley, David John, Kareena McCrindle, Stephen Rayner, Jonathan Sharpe, Czeslaw Pienkowski, and Carl Phillips. "The Application of Additional, Off-Line, Analysis Techniques to PCM Monitor Results to Aid the Efficient and Cost Effective Repackaging of Legacy PCM Wastes Containing Calcium and Potentially Plutonium Fluoride." In ASME 2009 12th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2009. http://dx.doi.org/10.1115/icem2009-16034.
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There are a small number of legacy, orphan waste, PCM (Plutonium Contaminated Material) drums at Sellafield Site containing calcium metal potentially contaminated by plutonium (Pu), some of which may be in the form of plutonium fluoride (PuF4). These drums were measured on a TRU-D® PCM Drum Monitor to give a Nuclear Safety value for the Pu mass based on Neutron Coincidence Counting (NCC) and the Pu isotopic composition measured for each drum using a germanium detector based High Resolution Gamma Spectrometry system. In some circumstances the presence of Pu in the form of PuF4 can cause a significant overestimate of the measured Pu mass. This is as a result of alphas emitted by the spontaneous decay of Pu isotopes interacting with light elements such as fluorine, resulting in the emission of “random” (alpha, n) neutrons. The potential overestimate may be very large for total neutron counting based systems if the presence of PuF4 is not accounted for in the system calibration. However, significant quantities of PuF4 may also result in overestimates for NCC systems due to potentially large statistical uncertainties in the measurement results caused by accidental coincidences involving the random (alpha, n) neutrons. Therefore in some circumstances, less pessimistic measurements may be obtained from the total neutron count, corrected using the measured “PuF4 ratio”. Standard TRU-D® Drum Monitor measurements of the calcium containing drums were carried out by plant operators. Relevant data was then downloaded from the plant instrument allowing additional off-line techniques to be applied to the high resolution gamma spectra associated with each drum. These spectra are routinely generated as part of the standard TRU-D® PCM Drum Monitor measurement. This analysis was based on the patented PuF4 analysis technique developed by VT Nuclear Services personnel to determine the mass ratio of Pu in the form of PuF4 to total Pu mass using the PuF4 reaction gammas and standard Pu gammas observed in the gamma spectrum. This additional, off-line analysis reduces the potential overestimate in the Pu Nuclear Safety Mass associated with each drum aiding the repackaging of the legacy material into Bull Pit cans. Following this, similar measurements and off-line analysis was carried out for the filled Bull Pit cans using a TRU-D® PCM Piece Monitor set up and commissioned specifically for this task. The further analysis results allowed the Bull Pit cans to be efficiently and cost effectively packed in 200 litre drums. The resulting new 200 litre drums were then measured using a standard, routinely operated TRU-D® PCM Drum Monitor for final sentencing (again taking into account off-line PuF4 analysis) to allow safe and secure storage. This paper describes the work carried out and the additional off-line PuF4 analysis techniques and how they have been applied within the exacting demands of Nuclear Safety in support of legacy material treatment and ultimate safe storage.
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Muñoz, Joshua, Masood Taheri Andani, and Mehdi Ahmadian. "Accuracy Analysis of Car Body-Mounted Doppler LIDAR Technology Used to Measure Track Speed and Curvature." In 2015 Joint Rail Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/jrc2015-5613.
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Modern track inspection technologies contribute to more efficient and reliable identification of track conditions including track geometry and sections requiring maintenance. Records of car body motion and rail conditions are also vital for derailment or track failure investigations. Doppler LIDAR technology is a tool with a vast array of utility in measuring speed of a moving target with a high degree of accuracy and precision, and has been proven by a Virginia Tech (VT) research team to record body motion and track curvature through car body speed characteristics. In the context of track maintenance, high sensitivity to rail surface deviations and signal fidelity at high speeds make LIDAR a desirable tool for collecting information on local curvature deviations and car body dynamic responses to such irregularities. Virginia Tech’s Railway Technologies Laboratory research team has completed extensive analysis on its Doppler LIDAR system’s ability to obtain train speed and track curvature profiles in terms of the system’s accuracy and dependency on car body motion during curve navigation. Due to the LIDAR system’s capability of providing curvature data from the speed profile, it follows that the LIDAR system also serves as a high-accuracy alternative to the geometry car’s IMU which also provides curvature data. Results show the LIDAR system records curves with a high correlation with ground truth measurements. The signal processing techniques used to reveal track curve and car body motion are reviewed to show that, indeed, the LIDAR system detects car body motion in addition to the track’s curvature profile. Results strongly suggest Doppler LIDAR serves as a high-accuracy alternative to multiple rail inspection instruments and provides useful data for the improvement of rail condition localization and mapping.
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Hosseinipour, Milad, Sajjad Z. Meymand, and Mehdi Ahmadian. "Vibration Analysis for Improving Powertrain Design and Contact Measurements of a Roller Rig." In 2015 Joint Rail Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/jrc2015-5622.
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This paper provides two vibration analyses on a scaled roller rig that is under construction at the Railway Technologies Laboratory of Virginia Tech (VT) for evaluating wheel/rail contact mechanics. The scaled vertical rig includes a wheel that is placed on a roller with similar profile of a U.S. 136 weight rail. Two independent AC servomotors enable controlling the relative speed of the disks to a high degree of precision. Linear actuators allow for adjusting the simulated load, wheel angle of attack, rail cant, and lateral position of the wheel with respect to the rail, including flanging. Rotation of each disk is dominated by internal dynamics of the motors, gearheads, couplers, and flexible shafts. As a result, dynamics of each component has direct effect on the relative speed of the wheel and the roller at the contact patch. On the other hand, it is essential to make sure that the measurements are only caused by the particular subject of study, and not any intermittent source of disturbance such as unbalanced rotation. Electromechanical models of the rig components have been developed in previous works of the authors for studying the overall behavior of the coupled drivelines. This study aims to fulfill the previous studies by analyzing the effect of incorporating compliant joints in the drivelines, as well as unbalanced dynamics in the disks. Appropriate consideration is given to providing an accurate mathematical model of each phenomenon. The mathematical models are solved numerically to carry out parametric studies that represent actual working conditions of the rig. The results of these studies indicate that incorporation of constant velocity joints in sensitive instruments like the roller rig, leads to inevitable axial vibrations that affect both driver and driven sides. This paper also provides a tool for filtering the undesired vibrations from the contact measurements due to unbalanced rotation or other sources of the same nature.
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Arantes, Julia Pimentel, Andressa Leite Ferraz De Melo, Luana Rossato, and Simone Simionatto. "ATIVIDADE ANTIBIOFILME DE NITRATO DE GÁLIO FRENTE A KLEBSIELLA PNEUMONIAE RESISTENTE A POLIMIXINA B." In I Congresso Nacional de Microbiologia Clínica On-Line. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1201.
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Introdução. O Biofilme é um importante fator de virulência que promove proteção da comunidade bacteriana. O gênero Klebsiella pertencente à família Enterobacteriaceae é considerado pela Organização Mundial de Saúde (OMS) um patógeno com prioridade crítica no desenvolvimento de novas estratégias terapêuticas, pois infecções graves são comuns em pacientes internados, com envolvimento de cepas multirresistentes. Dada a importância do ferro na fisiologia bacteriana e na sua patogenicidade, a captação e o metabolismo do ferro tornaram-se alvos atraentes para o desenvolvimento de novos fármacos antibacterianos. Assim, o fármaco nitrato gálio atua interrompendo vias metabólicas dependentes de ferro, tornando-se um inibidor do crescimento microbiano. Objetivo. No presente estudo exploramos o uso de nitrato de gálio frente a isolados de Klebsiella pneumoniae resistentes à polimixina B que apresentam características formadoras de biofilme. Material e Métodos. Foram utilizados dois isolados clínicos de Klebsiella pneumoniae resistentes à polimixina B formadores de biofilme. A inibição da formação de biofilme foi avaliada por método preconizados pelo CLSI. As placas foram incubadas por 24 horas a 37 °C em condições estáticas para permitir o crescimento bacteriano e a maturação do biofilme. O crescimento bacteriano foi quantificado usando um espectrógrafo de Microplato (BioTek Instruments Inc., Winooski, VT, USA) em um comprimento de onda de 600nm. O biofilme foi determinado utilizando a solução de cristal violeta (CV) à 0.1%. A inibição de biofilme foi calculada em relação à quantidade de biofilme cultivada na ausência de nitrato de gálio (definido como 100% biofilme) e ao controle de esterilidade do meio (definido como 0% biofilme). Os resultados foram mediados por duas réplicas biológicas separadas. Resultado. Os biofilmes foram avaliados em diversas concentrações do nitrato de gálio que variaram de 0.5 a 16 μg/mL. O nitrato de gálio apresentou atividade antibiofilme significativa frente à isolados clínicos de K. pneumoniae resistentes a polimixina B revelando sua melhor atividade na concentração de 16 μg/mL. Conclusão: O nitrato de gálio demostrou ser uma promissora abordagem no combate aos biofilmes bacterianos formados por K. pneumoniae resistente a polimixina B, revelando ser um fármaco seguro, pouco tóxico e com baixo potencial para desenvolvimento de resistência.