Articoli di riviste: "NVH tests"

1

Chakroun, Ala Eddin, Mattia Battarra e Emiliano Mucchi. "Influence of the Hydraulic Circuit Setup on the Dynamic Performance of an Axial Piston Pump by Numerical and Experimental Analysis". Mathematical Problems in Engineering 2024 (18 aprile 2024): 1–16. http://dx.doi.org/10.1155/2024/2966138.

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The hydraulic circuit in hydraulic mechanisms may be the cause of several vibration anomalies. Flexible pipes, in particular, commonly used in test rigs, may be the source of vibration issues due to their relatively low natural frequencies altering the pump noise, vibration, and harshness (NVH) performance. The purpose of this study is to detail a methodology based on lumped parameter modeling and experiments to analyze the circuit NVH behavior. An experimental study is carried out on two pump designs to determine the outlet pressure fluctuation of various test rig configurations. Numerical simulations are also performed to simulate the actual behavior of the hydraulic system considering these different test configurations. The tests are carried out at a chosen frequency range with a hydraulic circuit configuration representing realistic layouts. In these situations, the hydraulic circuit layout can be the source of NVH anomalies. Realistic design solutions are proposed to modify the test rig NVH behavior in order to achieve a flat response throughout the desired working range.

2

Singh, Rahul, Amogh Nalawade, Manish Pande e Punit Singh. "Vibration and noise characteristics of an inverter for electric vehicle application". Vibroengineering Procedia 50 (21 settembre 2023): 145–51. http://dx.doi.org/10.21595/vp.2023.23563.

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Noise, Vibration & Harshness (NVH) is one of the key parameters associated with comfort of an automobile. An Electric Vehicle (EV) consists of transmission driven by electric motor which ultimately gets its power or current supply from inverter. As per Electric vehicle architecture, motor ranks first followed by transmission and inverter in terms of NVH performance. The function of an inverter is to convert DC current from battery source to 3-phase AC current which goes to electric motor. Torque and speed characteristics of motor is dependent on current and voltage supply from inverter. Hence it is important to assess NVH characteristics of inverter as well. In this paper, vibration and acoustic performance of a standalone EV inverter have been studied by testing it at different vehicle operating conditions. Ideally the output 3 phase AC current from inverter should contain only electrical frequency, but it is observed that AC current contains harmonics in the form of linear combination of electrical frequency and switching frequency. From this study, observations from NVH tests on an EV inverter is highlighted in frequency range where relatively high vibration and noise levels were present.

3

Schweighardt, A., B. Vehovszky e D. Feszty. "The effect of the preload determination process on dynamic mechanical properties". Journal of Physics: Conference Series 2677, n. 1 (1 dicembre 2023): 012007. http://dx.doi.org/10.1088/1742-6596/2677/1/012007.

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Abstract NVH simulation and experimental methods are getting more and more important because of the increased customer needs for reliability and comfort. In order to obtain appropriate NVH simulation results accurate material properties have to be provided as input parameters. In case of the dynamic mechanical property determination of acoustic viscoelastic foams the results may vary greatly depending on the measurement settings and the quality of the measurement. This study evaluates the effect of the preload determination process on dynamic mechanical properties and the repeatability of the dynamic compression tests. Finally, conclusions are drawn and suggestions are made for the settings.

4

Guinebretière, Marie-Hélène, Sandrine Auger, Nathalie Galleron, Matthias Contzen, Benoit De Sarrau, Marie-Laure De Buyser, Gilles Lamberet et al. "Bacillus cytotoxicus sp. nov. is a novel thermotolerant species of the Bacillus cereus Group occasionally associated with food poisoning". International Journal of Systematic and Evolutionary Microbiology 63, Pt_1 (1 gennaio 2013): 31–40. http://dx.doi.org/10.1099/ijs.0.030627-0.

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An aerobic endospore-forming bacillus (NVH 391-98T) was isolated during a severe food poisoning outbreak in France in 1998, and four other similar strains have since been isolated, also mostly from food poisoning cases. Based on 16S rRNA gene sequence similarity, these strains were shown to belong to the Bacillus cereus Group (over 97 % similarity with the current Group species) and phylogenetic distance from other validly described species of the genus Bacillus was less than 95 %. Based on 16S rRNA gene sequence similarity and MLST data, these novel strains were shown to form a robust and well-separated cluster in the B. cereus Group, and constituted the most distant cluster from species of this Group. Major fatty acids (iso-C15 : 0, C16 : 0, iso-C17 : 0, anteiso-C15 : 0, iso-C16 : 0, iso-C13 : 0) supported the affiliation of these strains to the genus Bacillus , and more specifically to the B. cereus Group. NVH 391-98T taxon was more specifically characterized by an abundance of iso-C15 : 0 and low amounts of iso-C13 : 0 compared with other members of the B. cereus Group. Genome similarity together with DNA–DNA hybridization values and physiological and biochemical tests made it possible to genotypically and phenotypically differentiate NVH 391-98T taxon from the six current B. cereus Group species. NVH 391-98T therefore represents a novel species, for which the name Bacillus cytotoxicus sp. nov. is proposed, with the type strain NVH 391-98T ( = DSM 22905T = CIP 110041T).

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Dziechciarz, Arkadiusz, Aron Popp, Claudia Marțiș e Maciej Sułowicz. "Analysis of NVH Behavior of Synchronous Reluctance Machine for EV Applications". Energies 15, n. 8 (11 aprile 2022): 2785. http://dx.doi.org/10.3390/en15082785.

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In this paper, an analysis of noise and vibration of a synchronous reluctance machine for EV applications is performed. The analyzed machine was designed for electric vehicle application. The noise and vibration of a synchronous reluctance machine were first estimated during simulations; next, the obtained results were validated during laboratory tests. The analyzed model of the machine was simplified and included only stator core as it was assumed to be the main source of the machine vibration and generated noise. To simulate the noise and vibration of the machine, multiphysics modeling of the machine was performed. Laboratory tests proved the correctness of performed simulations. The obtained results allowed us to investigate the influence of the machine’s operating point on the generated noise and vibration. The frequency of the magnetic radial forces were proven to be the dominant factor in noise generation. The influence of the load and current angle on the machine’s noise and vibration was proven to be negligible. It was also proven that considering only the stator structure in numerical analysis of the noise and vibration of the machine leads to valuable results.

6

Guo, Han, Jianwu Zhang e Haisheng Yu. "Robust optimisation of dynamic and NVH characteristics for compound power-split hybrid transmission". Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 233, n. 4 (25 giugno 2019): 817–26. http://dx.doi.org/10.1177/1464419319856774.

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In this paper, vibro-acoustic characteristics of a power-split hybrid transmission including a compound planetary gear set are investigated by numerical procedure and refined system dynamics modelling. For validation of the numerical predictions, bench tests are performed for dynamic and acoustic responses of the hybrid transmission, contribution rates of acoustic radiation power induced due to the planetary gears, support bearings, transmission shafts and the gearbox housing are estimated. In improving the noise, vibration and harshness (NVH) performance of the transmission during hybrid vehicle acceleration, traction torques of the motors against the planetary gear parametric resonance are formulated and an optimal control strategy is proposed. By real road NVH test results acquired on board of the midsize hybrid car, it is demonstrated that a significant reduction of the planetary gear whine noise is achieved. As a result, numerical approaches applied to establish relationships between torques of the two traction motors and parametric excitations of the compound planetary gear train are experimentally validated.

7

Li, Hui Bin, Awais A.M., Qi Chen Lu e De Quan Jin. "Experimental Study on Durability and NVH of Rear Driving Axle of Minibus". Advanced Materials Research 655-657 (gennaio 2013): 511–14. http://dx.doi.org/10.4028/www.scientific.net/amr.655-657.511.

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Experiments on the durability for the rear driving axle were conducted in bench tests. By using time domain and frequency domain methods, the vibration and noise signals at bearings of driving axle were sampled and then analyzed. On the one hand, we find that the vibration level and noise level change with the wear of gears and bearings. On the other hand, with the development of the wear of gear and bearings, the frequency components of vibration and noise change with time. These experimental results will give help to further study of the durability and NVH characteristic of the rear driving axle.

8

Shi, Hui, Wenku Shi, Liang Sun e Zhiyong Chen. "Improving Camper Comfort by Optimizing the Vibration Isolation of Air-Conditioning Compressor". Mathematical Problems in Engineering 2020 (23 dicembre 2020): 1–14. http://dx.doi.org/10.1155/2020/2958604.

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Compressors are the main excitation source of vibration and noise in camper air-conditioning systems, which directly affects the NVH characteristics in campers. The vibration and noise reduction for camper comfort improvement can be implemented by the optimization method. This paper presents vibration and noise improvement in camper by systematically optimizing the vibration isolation performance of air-conditioning compressor. To analyze the compressor vibration characteristics, operational vibration tests under different conditions and modal identification are implemented. Based on the analysis results, a genetic algorithm is used to optimize the stiffness of the compressor vibration isolation element by the energy decoupling method (EDM). The stiffness, natural frequencies, and energy decoupling rate (EDR) of the compressor vibration isolation system (CVIS) are compared between preoptimization and postoptimization. The stiffness and strength characteristics of the optimized isolation system are verified by the finite element method. Operational vibration and noise tests of a camper are performed to validate the optimization effect. The improvement of camper comfort demonstrates that the proposed optimization procedure of CVIS is effective.

9

Yong, Sukjun, e JangSeok Park. "A study on the new PET composite sound-absorbing material applicable to automotive interior materials". INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, n. 4 (1 febbraio 2023): 3297–302. http://dx.doi.org/10.3397/in_2022_0466.

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Various types of sound-absorbing materials are used in vehicles according to external noise and conditions. As sound-absorbing materials for automobiles, there are fiber-type materials such as PET fiber or glass fiber, and foam-type materials such as polyurethane. Among them, PET fiber materials have excellent advantages in terms of weight reduction and recycling, but urethane foam is applied due to their low NVH performance and compressive stress. Recently, as interest in eco-friendly vehicles increases, development of sound absorbing materials using PET fiber is required. To improve this problem, in this study, research was conducted on improving sound absorption performance and compression performance by changing the composition ratio of PET fibers constituting the sound absorption material. The acoustic properties were measured by ALPHA-CABIN and BUCK tests

10

Kyprianou, A., J. Giacomin, K. Worden, M. Heidrich e J. Bocking. "Differential evolution based identification of automotive hydraulic engine mount model parameters". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 214, n. 3 (1 marzo 2000): 249–64. http://dx.doi.org/10.1243/0954407001527402.

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Hydraulic engine mounts are commonly used in automotive applications, and numerical models exist for performing full-vehicle noise, vibration and harshness (NVH) studies by means of multibody simulation. The parameters of these models are usually determined by the manufacturer from first-principle numerical calculations, or by means of direct testing of the individual components. This paper describes, instead, a four-step identification method developed to determine the parameter values of a specific hydromount numerical model, the Freudenberg hydromount equations, a set of highly non-linear piecewise-continuous differential equations. The identification procedure is based on two concepts, the first being the use of the differential evolution algorithm for determining optimal parameter values, while the second is the use of data obtained from a series of experimental tests of progressively higher displacement amplitude. Identified parameters provide models whose mean square errors between the calculated output force time history and the experimentally measured force time history are typically of the order of 1-2 per cent.

11

Farshidianfar, A., M. Ebrahimi, H. Rahnejat, M. T. Menday e M. Moavenian. "Optimization of the high-frequency torsional vibration of vehicle driveline systems using genetic algorithms". Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 216, n. 3 (1 settembre 2002): 249–62. http://dx.doi.org/10.1177/146441930221600305.

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Vehicle drivelines with manual transmissions are exposed to different dynamic engine torques under driving conditions. Engine torque can dramatically vary with throttle demand from coast to drive condition and, conversely, with throttle release from drive to coast. Abrupt application or release of throttle in slow moving traffic or rapid engagement of the clutch can be followed by an audible response, referred to in industry as the clonk noise. This paper presents a complete dynamic model of a vehicle driveline for the optimization of high-frequency torsional vibration by the distributed-lumped (hybrid) modelling technique (DLMT). The model used is first validated against experimental tests. Parameter sensitivity studies have been carried out using the model to identify the important components affecting clonk. Three key parameters have been chosen from the parameter study. To optimize these key factors, genetic algorithms (GAs) have been used in this multi-parameter optimization problem. The GAs show significant reduction in the driveline noise, vibration and harshness (NVH).

12

Szlichting, Maciej, Dariusz M. Bieliński, Jacek Rogowski, Marcin Kozanecki e Tomasz Dąbrowski. "PHYSICOCHEMICAL ASPECTS OF THE WORK OF PASSENGER CAR BRAKE LININGS. PART II THE EFFECT OF LUBRICATING ADDITIVES". Tribologia 301, n. 3 (30 novembre 2022): 121–36. http://dx.doi.org/10.5604/01.3001.0016.1043.

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The paper presents the influence of various systems of lubricating additives which determine the performance of the friction materials of brake linings. The base hybrid friction material formulation was modified with various types of lubricating additives. These additives are divided into groups containing commonly used lubricating materials: carbons and sulphides, compounded in various proportions, influencing the formation and structure of the so-called third body layer (TBL) on the surface of the brake disc because of braking. Raman Spectroscopy (RS), time of flight Secondary Ion Mass Spectroscopy (ToF-SIMS) and high-resolution scanning electron microscopy with an X-ray analyser (SEM-EDS) equipped with a focus ion beam (FIB) were used for chemical and morphological analysis of the surface layer of brake disc after breaking tests. The results of the physicochemical analysis of TBL were correlated with the results of tribological tests (according to the SAE-J2522 procedure, commonly known as AK-Master) on a brake dynamometer adapted to the measurements of acoustic signals (NVH – noise, vibration, and harshness). The obtained results confirm the important role played by the so-called third body layer, formed on the surface of the brake disc for safety (COF), durability (wear of friction elements) and the acoustic spectrum accompanying braking.

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Szlichting, Maciej, Dariusz M. Bieliński, Iwona Jóźwik, Anna Kosińska e Tomasz Dąbrowski. "PHYSICOCHEMICAL ASPECTS OF THE WORK OF PASSENGER CAR BRAKE LININGS. Part I: THE EFFECT OF FRICTIONAL ADDITIVES". Tribologia 300, n. 2 (29 luglio 2022): 89–100. http://dx.doi.org/10.5604/01.3001.0015.9728.

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The paper presents the influence of various systems of abrasive additives which determine the performance of the friction materials of brake pads. A friction material was used for the tests, in which the base recipe was modified with various types of abrasive additives: 1. “low steel” – of low steel content, containing aluminium and chromium oxides; 2. “hybrid” – containing in addition to abrasive components from the low steel family, abrasive components such as zirconium silicate, magnesium oxide or iron oxides, which are characteristic of the family of asbestos-free organic materials (NAO); and 3. “mild hybrid” – containing abrasive components found in the friction materials of the NAO family, on the formation and structure of the so-called third body on the surface of the brake disc as a result of braking. High-resolution scanning electron microscopy with an X-ray analyser (SEM-EDS) equipped with a focus ion beam (FIB) was used to study film thickness, morphology, and chemical composition. The results of the physicochemical analysis of the third body were correlated with the results of tribological tests on a brake dynamometer adapted to the measurements of acoustic signals (NVH – noise, vibration and harshness). The tests were carried out in accordance with the SAE-J2522 procedure, commonly known as AK-Master. The obtained results confirm the important role played by the so-called third body, formed on the surface of the brake disc for safety (COF), durability (wear of friction elements) and the acoustic spectrum accompanying braking.

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Mostafavi Yazdi, Seyed Jamaleddin, Seongchan Pack, Foroogh Rouhollahi e Javad Baqersad. "A Modeling Framework to Develop Materials with Improved Noise and Vibration Performance for Electric Vehicles". Energies 16, n. 9 (3 maggio 2023): 3880. http://dx.doi.org/10.3390/en16093880.

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The automotive and aerospace industries increasingly use lightweight materials to improve performance while reducing fuel consumption. Lightweight materials are frequently used in electric vehicles (EVs). However, using these materials can increase airborne and structure-borne noise. Furthermore, EV noise occurs at high frequencies, and conventional materials have small damping. Thus, there is an increasing need for procedures that help design new materials and coatings to reduce the transferred and radiated noise at desired frequencies. This study pioneered new techniques for microstructure modeling of coated and uncoated materials with improved noise, vibration, and harshness (NVH) performance. This work uses the microstructure of materials to study their vibration-damping capacity. Images from an environmental scanning electron microscope (ESEM) show the microstructure of a sample polymer and its coating. Tensile tests and experimental modal analysis were used to obtain the material properties of the polymer for microstructure modeling. The current work investigates how different microstructure parameters, such as fiberglass volume fraction and orientation, can change the vibration performance of materials. The damping ratio in the study was found to be affected by changes in both the direction and volume ratio of fiberglass. Furthermore, the effects of the coating are investigated in this work. Through modal analysis, it was observed that increasing the thickness of aluminum and aluminum bronze coatings caused a rightward shift in resonance frequency. Coatings with a thickness of 2 mm were found to perform better than those with lower thicknesses. Furthermore, the aluminum coating resulted in a greater shift in frequency than the aluminum bronze coating. Additionally, the coating with a higher damping ratio (i.e., aluminum bronze) significantly reduced the amplitude of surface velocity due to excitation, particularly at higher frequencies. This study provides engineers with an understanding of the effects of layer coating on the NVH performance of components and a modeling approach that can be used to design vehicles with enhanced noise and vibration performance.

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Dowsett, Amy, Dan O’Boy, Stephen Walsh, Ali Abolfathi e Steve Fisher. "The prediction of measurement variability in an automotive application by the use of a coherence formulation". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 232, n. 12 (24 ottobre 2017): 1694–700. http://dx.doi.org/10.1177/0954407017734768.

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Variability between nominally identical vehicles is an ever-present problem in automotive vehicle design. In this paper, it is shown that it is possible to quantify and, therefore, separate the measurement variability arising from a number of tests on an individual vehicle from the vehicle-to-vehicle variability arising from the manufacturing process with a series of controlled experiments. In this paper, coherence data is used to identify the measurement variability and, thus, to separate these two variability sources. In order to illustrate the methodology, a range of nominally identical automotive vehicles have been tested for NVH (noise, vibration and harshness) variability by exciting the engine mount with an impact hammer and measuring the excitation force and corresponding velocity responses at different points on the vehicle. Normalised standard deviations were calculated for the transfer mobility data, giving variability values of 25.3%, 33.5% and 37.3% for the responses taken at the suspension strut, upper A-pillar and B-pillar, respectively. The measurement variability was determined by taking repeat measurements on a single vehicle, and was found to be 2.9%. The measurement variability predicted by the coherence data on the multi-vehicle tests was compared with the directly taken repeat measurements taken on a single vehicle and these were shown to agree well with one another over the frequency range of interest.

16

Kowalski, D., M. D. Rao, J. Blough e S. Gruenberg. "Dynamic testing of shock absorbers under non-sinusoidal conditions". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 216, n. 5 (1 maggio 2002): 373–84. http://dx.doi.org/10.1243/0954407021529183.

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This paper deals with the dynamic characterization of an automotive shock absorber, the continuation of an earlier work [1]. The objective of this ongoing research is to develop a testing and analysis methodology for obtaining dynamic properties of automotive shock absorbers for use in CAE-NVH low-to-mid-frequency chassis models. Stepped sine sweep excitation is currently used in industry to obtain shock absorber parameters along with their frequency and amplitude dependence. Sine-on-sine testing, which involves excitation using two different sine waves, has been done in this study to understand the effects of the presence of multiple sine waves on the estimated dynamic properties. In an effort to obtain all frequency dependent parameters simultaneously, different types of broadband random excitation have also been studied. Results are compared with stepped sine sweep tests. Additionally, actual road data measured on different road profiles have been used as input excitation to obtain the shock absorber parameters for broad frequency bands under realistic amplitude and frequency conditions. These results are compared with both simulated random excitation and stepped sine sweep test results.

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Gräbner, Nils, Dominik Schmid e Utz von Wagner. "On Drum Brake Squeal—Assessment of Damping Measures by Time Series Data Analysis of Dynamometer Tests and Complex Eigenvalue Analyses". Machines 11, n. 12 (24 novembre 2023): 1048. http://dx.doi.org/10.3390/machines11121048.

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Brake squeal—an audible high-frequency noise phenomenon in the range between 1 kHz and 15 kHz resulting from self-excited vibrations—is one of the main cost drivers while developing brake systems. Increasing damping is often a crucial factor in the context of self-excited vibrations. Countermeasures applied for preventing brake squeal have been investigated particularly for disk brakes in the past. However, in recent years, drum brakes have once again become more important, partly because of the issue of particle emissions. Concerning noise problems, drum brakes have a decisive advantage compared to disk brake systems in that the outer drum surface is freely accessible for applying damping devices. This paper focuses on the fundamental proving and evaluation of passive damping measures on a simplex drum brake system. To obtain a detailed understanding of the influence of additional damping on the squealing behavior of drum brakes, extensive experimental investigations are performed on a brake with an intentionally introduced high squealing tendency in the initial configuration. This made it possible to investigate the influence of different types of damping measures on their effectiveness. Techniques from the field of big data analysis and machine learning are tested to detect squeal in measured time series data. These techniques were remarkably reliable and made it possible to detect squeal efficiently even in data that was not generated on a traditional costly NVH brake dynamometer. To investigate whether the simulation method usually used for the simulation of brake squeal is applicable to depicting the influence of additional damping in drum brakes, a complex eigenvalue analysis was performed with Abaqus, and the results were compared with those from the experiments.

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Bhavi, Iresh, Vinay Kuppast e Shivakant Kurbet. "Experimental Setup and Methodology to Carryout Fatigue Testing of Spiral Bevel Gears Used in Differential Gear Box Using NVH Approach". Applied Mechanics and Materials 852 (settembre 2016): 545–50. http://dx.doi.org/10.4028/www.scientific.net/amm.852.545.

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Currently the fatigue testing of bevel gears are being done by using non rotating type of fixtures that applies fatigue load on a single tooth, which does not resemble the actual loading condition in an automotive differential gear box. This paper discusses the experimental setup with the noise and vibration analysis approach to determine the signature of failures of spiral bevel gears. The proposed experimental setup seems promising for further research and development in the fatigue testing of spiral bevel gears. The Crown pinion and wheel assembly is used for the testing. The pinion is connected to the electric 3 phase AC motor of 75HP with a suitable coupling and the crown wheel is mounted on the half axle shaft, which in turn is connected to an electric dynamometer. The speed/torque of electric motor and the load applied by the dynamometer can be varied. The acoustic sensor is mounted near the differential gear box and the accelerometers are mounted on the Pinion bearing, Crown wheel bearing and the half axle bearing. A four channel data acquisition system is used to log data in time domain (raw data) by three accelerometers and an acoustic sensor. The variations of sound pressure(dB) v/s time, sound Pressure(FFT-(RMS)) amplitude v/s Frequency, Acceleration v/s Time, Octave analysis i.e., Band power v/s Frequency, Noise spectrum Power v/s Frequency, Histogram, Power density v/s Time can be obtained. These data are then used to plot vibration and SPP levels in frequency domain to develop the noise and vibration signature of that crown pinion for given cycles of operation. The tests on Bevel pinion and gear set were performed in the BEC, Bagalkot NVH lab facility. The gear set run successfully at double the rated torque for 30 million pinion cycles. And the signature of pinion failure was obtained. The results demonstrated the suitability of using the given bevel crown pinion and gears set for specified speed, high load application in differential gear box of an automobile.

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Sidorova, Valentina Ivanovna, Saule Zhangirovna Asylbekova, Nadezhda Ivanovna Yеnvareva, Saya Kashkinbayevna Koyshibaeva, Nina Sergeevna Badryzlova, Alyona Aleksandrovna Mukhramova e Azis Vasilyevich Shutkarayev. "Extruded starter compound feeds for clarid catfish". Vestnik of Astrakhan State Technical University. Series: Fishing industry 2020, n. 2 (30 giugno 2020): 82–92. http://dx.doi.org/10.24143/2072-9502-2020-2-82-93.

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Industrial fish-breeding is a promising trend for freshwater aquaculture development. The production of clarid catfish in Kazakhstan has advantages over traditionally grown fish species (trout, sturgeon) due to their valuable edible qualities. Clarid catfish grows very quickly even at high seeding densities, is undemanding to the environment, resistant to diseases, and effectively assimilates food. When growing clarid catfish in water recycling systems it is possible to refuse using oxygen equipment, because the fish species can use atmospheric air for breathing. As a result, the construction of such plants can save up to 40% of capital investments. In the course of the research, the physiological nutritional requirements of clarid catfish juveniles were established. Based on the data obtained there have been developed two extruded starter compound feed recipes for clarid catfish juveniles containing protein/fat 53.5 : 11.4 and 61.85 : 5.82 and energy exchange energy value varying within 16.46 - 17.12 MJ/kg. There have been conducted the production tests on assessing the efficiency of the developed compound feed and their intake by larvae and clarid catfish fry in the fish farms of “Kapshagayskoye NVH-1973”, LLP and “HalykBalyk”, LLP. The feed Aller Agua (Denmark) served as a control feed for comparing the nutritional and consumer qualities of the developed feed for trout. The determined feeding ratio of the developed feed did not exceed 0.93 units, it was insignificantly inferior to the import feed. The fry survival rate made 76% when using both the control and developed feed. The compound feeds for clarid catfish juveniles were developed by extruding, which allowed to obtain increased digestibility, water resistance and extended storage life. Introducing these feeds into the fish breeding practice will help to increase the efficiency of clarid catfish fry growth and expand opportunities of aquaculture facilities.

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Walsh, JM. "NIH drug tests". Science 240, n. 4850 (15 aprile 1988): 268.1–268. http://dx.doi.org/10.1126/science.3353719.

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&NA;. "NIH Provides Resource to Clarify Genetic Tests". Nurse Educator 37, n. 4 (2012): 172. http://dx.doi.org/10.1097/nne.0b013e31825a868b.

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Holden, C. "NIH scientists balk at random drug tests". Science 239, n. 4841 (12 febbraio 1988): 724. http://dx.doi.org/10.1126/science.3340853.

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Fordham, J. N. "From the NIH. Magnetic device tests for iron overload". JAMA: The Journal of the American Medical Association 254, n. 8 (23 agosto 1985): 1006–8. http://dx.doi.org/10.1001/jama.254.8.1006.

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Langer, Kailey, Cheshire Hardcastle, Hanna Hausman, Jessica Kraft, Alejandro Albizu, Nicole Evangelista, Emanuel Boutzoukas et al. "28 Factor Structure of Conventional Neuropsychological Tests and NIH-Toolbox in Healthy Older Adults". Journal of the International Neuropsychological Society 29, s1 (novembre 2023): 710. http://dx.doi.org/10.1017/s135561772300886x.

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Objective:The National Institutes of Health-Toolbox cognition battery (NIH-TCB) is widely used in cognitive aging studies and includes measures in cognitive domains evaluated for dimensional structure and psychometric properties in prior research. The present study addresses a current literature gap by demonstrating how NIH-TCB integrates into a battery of traditional clinical neuropsychological measures. The dimensional structure of NIH-TCB measures along with conventional neuropsychological tests is assessed in healthy older adults.Participants and Methods:Baseline cognitive data were obtained from 327 older adults. The following measures were collected: NIH-Toolbox cognitive battery, Controlled Oral Word Association (COWA) letter and animals tests, Wechsler Test of Adult Reading (WTAR), Stroop Color-Word Interference Test, Paced Auditory Serial Addition Test (PASAT), Brief Visuospatial Memory Test (BVMT), Letter-Number Sequencing (LNS), Hopkins Verbal Learning Test (HVLT), Trail Making Test A&B, Digit Span. Hmisc, psych, and GPARotation packages for R were used to conduct exploratory factor analyses (EFA). A 5-factor solution was conducted followed by a 6-factor solution. Promax rotation was used for both EFA models.Results:The 6-factor EFA solution is reported here. Results indicated the following 6 factors: working memory (Digit Span forward, backward, and sequencing, PASAT trials 1 and 2, NIH-Toolbox List Sorting, LNS), speed/executive function (Stroop color naming, word reading, and color-word interference, NIH-Toolbox Flanker, Dimensional Change, and Pattern Comparison, Trail Making Test A&B), verbal fluency (COWA letters F-A-S), crystallized intelligence (WTAR, NIH-Toolbox Oral Recognition and Picture Vocabulary), visual memory (BVMT immediate and delayed), and verbal memory (HVLT immediate and delayed. COWA animals and NIH-Toolbox Picture Sequencing did not adequately load onto any EFA factor and were excluded from the subsequent CFA.Conclusions:Findings indicate that in a sample of healthy older adults, these collected measures and those obtained through the NIH-Toolbox battery represent 6 domains of cognitive function. Results suggest that in this sample, picture sequencing and COWA animals did not load adequately onto the factors created from the rest of the measures collected. These findings should assist in interpreting future research using combined NIH-TCB and neuropsychological batteries to assess cognition in healthy older adults.

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Hay, Mark E. "Negating the plant apparency model: rigorous tests are the fuel of progress". New Phytologist 210, n. 3 (13 aprile 2016): 770–71. http://dx.doi.org/10.1111/nph.13953.

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Burnett, Mark G., Seema S. Sonnad e Sherman C. Stein. "Screening tests for normal-pressure hydrocephalus: sensitivity, specificity, and cost". Journal of Neurosurgery 105, n. 6 (dicembre 2006): 823–29. http://dx.doi.org/10.3171/jns.2006.105.6.823.

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Object Many tests have been proposed to help choose candidates for shunt insertion in cases of suspected normal-pressure hydrocephalus (NPH). It is unclear what sensitivity and specificity a prospective test must have to improve outcomes, compared with the results of automatic shunt insertion. Methods The authors adapted the decision analysis model used in a companion article to allow for application of a screening test. Using the reported sensitivities and specificities of several such tests, they evaluated the effects such tests would have on the expected outcome of an average 65-year-old patient with moderate dementia. They also evaluated the cost-effectiveness of a theoretical screening test with superior sensitivity and specificity. Conclusions Although external lumbar drainage comes quite close, none of the screening tests reported to date have sufficient sensitivity and specificity to improve expected outcome in an average candidate, compared with the results of automatic shunt placement in cases of suspected NPH. In addition, even a theoretically improved test would need to be considerably less expensive than prolonged lumbar drainage to be cost-effective in clinical practice.

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Holdnack, James A., Grant L. Iverson, Noah D. Silverberg, David S. Tulsky e Allen W. Heinemann. "NIH toolbox cognition tests following traumatic brain injury: Frequency of low scores." Rehabilitation Psychology 62, n. 4 (novembre 2017): 474–84. http://dx.doi.org/10.1037/rep0000145.

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Chartier, Philippe. "L’apport des tests d’aptitudes dans le recrutement : l’exemple de la NV5-R". Psychologie du Travail et des Organisations 15, n. 2 (2009): 137–50. http://dx.doi.org/10.1016/s1420-2530(16)30179-0.

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Cacho, N. Ivalú, Daniel J. Kliebenstein e Sharon Y. Strauss. "Macroevolutionary patterns of glucosinolate defense and tests of defense-escalation and resource availability hypotheses". New Phytologist 208, n. 3 (20 luglio 2015): 915–27. http://dx.doi.org/10.1111/nph.13561.

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Burns, Jean H., Jennifer E. Murphy e Yu‐Long Zheng. "Tests of alternative evolutionary models are needed to enhance our understanding of biological invasions". New Phytologist 222, n. 2 (29 novembre 2018): 701–7. http://dx.doi.org/10.1111/nph.15584.

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Baer, George M. "Evaluation of an animal rabies vaccine by use of two types of potency tests". American Journal of Veterinary Research 58, n. 8 (1 agosto 1997): 837–40. http://dx.doi.org/10.2460/ajvr.1997.58.08.837.

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Abstract Objective To evaluate the potency of an inactivated animal rabies vaccine for domestic animals by use of 2 types of potency tests after challenge exposure with a laboratory standard virus or 1 of 5 viruses obtained from various wildlife species. Animals 384 mice vaccinated twice intraperitoneally; 384 mice vaccinated once IM. Procedure Mice vaccinated with an inactivated, adjuvanted rabies vaccine for domestic animals were challenge exposed with the common fixed challenge virus or 1 of 5 rabies viruses obtained from wild animal species (street viruses) that most commonly transmit the virus in the United States and Canada. Potency tests included 2 types of antigen extinction tests: the National Institutes of Health (NIH) test and the Centers for Disease Control test. Results Results of both tests indicated that protection was highest against raccoon and bat viruses. Marked differences were detected in the relative potency ratios for the NIH versus the Centers for Disease Control tests, though the relative potencies themselves (against the street viruses) did not differ markedly. Conclusions The markedly reduced potency against the street viruses indicated by the NIH test results was suggestive of an inherent bias associated with double intraperitoneal vaccination and intracerebral challenge exposure, whereas the single IM vaccination and IM challenge exposure reduced that bias. (Am J Vet Res 1997;58:837–840)

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Hušková, Marie, Simos G. Meintanis, Natalie Neumeyer e Charl Pretorius. "Independence tests in semiparametric transformation models". South African Statistical Journal 52, n. 1 (2018): 1–13. http://dx.doi.org/10.37920/sasj.2018.52.1.1.

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Consider an observed response Y which, following a certain transformation T(Y), can be expressed by a homoskedastic nonparametric regression model referenced by a vector X of regressors. If this transformation model is indeed valid then conditionally on X, the values of T(Y) may be viewed as being just location shifts of the regression error, for some value of the transformation parameter. We propose tests for the validity of this model, and establish the limiting distribution of the test statistics under the null hypothesis and under alternatives. Since the null distribution is complicated we also suggest a certain resampling procedure in order to approximate the critical values of the tests, and subsequently use this type of resampling in a Monte Carlo study of the finite-sample properties of the new tests. In estimating the model we rely on the methods proposed by Neumeyer, Noh and Van Keilegom (2016) for the aforementioned transformation model. Our tests however deviate from the tests suggested by Neumeyer et al. (2016) in that we employ an analogue of the test suggested by Hlávka, Hušková and Meintanis (2011) involving characteristic functions, rather than distribution functions.

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Benko, I. S., B. Bhargava e W. N. Rothenbuhler. "Prototype NGH Subsynchronous Resonance Damping Scheme. Part II???Switching and Short Circuit Tests". IEEE Power Engineering Review PER-7, n. 11 (novembre 1987): 48. http://dx.doi.org/10.1109/mper.1987.5526912.

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Rubinstein, Wendy S., Brandi L. Kattman, Adriana J. Malheiro, Jennifer M. Lee, Donna R. Maglott, Vichet Hem, Michael Ovetsky et al. "The NIH genetic testing registry: Hereditary, pharmacogenetic, and somatic tests for oncology practice." Journal of Clinical Oncology 32, n. 15_suppl (20 maggio 2014): 11104. http://dx.doi.org/10.1200/jco.2014.32.15_suppl.11104.

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Benko, I. S., B. Bhargava e W. N. Rothenbuhler. "Prototype NGH Subsynchronous Resonance Damping Scheme Part II - Switching and Short Circuit Tests". IEEE Transactions on Power Systems 2, n. 4 (1987): 1040–47. http://dx.doi.org/10.1109/tpwrs.1987.4335298.

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Gershon, Richard C., Karon F. Cook, Dan Mungas, Jennifer J. Manly, Jerry Slotkin, Jennifer L. Beaumont e Sandra Weintraub. "Language Measures of the NIH Toolbox Cognition Battery". Journal of the International Neuropsychological Society 20, n. 6 (24 giugno 2014): 642–51. http://dx.doi.org/10.1017/s1355617714000411.

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AbstractLanguage facilitates communication and efficient encoding of thought and experience. Because of its essential role in early childhood development, in educational achievement and in subsequent life adaptation, language was included as one of the subdomains in the NIH Toolbox for the Assessment of Neurological and Behavioral Function Cognition Battery (NIHTB-CB). There are many different components of language functioning, including syntactic processing (i.e., morphology and grammar) and lexical semantics. For purposes of the NIHTB-CB, two tests of language—a picture vocabulary test and a reading recognition test—were selected by consensus based on literature reviews, iterative expert input, and a desire to assess in English and Spanish. NIHTB-CB’s picture vocabulary and reading recognition tests are administered using computer adaptive testing and scored using item response theory. Data are presented from the validation of the English versions in a sample of adults ages 20–85 years (Spanish results will be presented in a future publication). Both tests demonstrated high test–retest reliability and good construct validity compared to corresponding gold-standard measures. Scores on the NIH Toolbox measures were consistent with age-related expectations, namely, growth in language during early development, with relative stabilization into late adulthood. (JINS, 2014, 20, 1–10)

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Kodama, Yusuke, Shi Jie Zhu, Yukiko Nakahara, Arimitsu Usuki e Makoto Kato. "Fatigue Fracture of Clay Reinforced Nylon Nanocomposites". Materials Science Forum 750 (marzo 2013): 11–14. http://dx.doi.org/10.4028/www.scientific.net/msf.750.11.

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Nylon 6 clay hybrid (NCH) composite consists of nano-sized Montmorillonite and nylon 6 matrix. The testing materials were nylon 6, NCH-2 (2 wt% clay reinforced composite) and NCH-5 (5 wt% clay reinforced composite). Fatigue tests at the glass transition temperatures (35 °C and 50 °C) were performed with a stress ratio of 0.1 and frequency of 0.1Hz. NCH-2 had the highest fatigue strength at room temperature, but NCH-5 had the highest fatigue strengths at 35 °C and 50 °C. It was found that the fracture origin changed from surfaces to interior of specimens with an increase in temperature in NCH-2 and NCH-5.

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Solana, Elisabeth, Maria Antonia Poca, Juan Sahuquillo, Bessy Benejam, Carme Junqué e Mithilesh Dronavalli. "Cognitive and motor improvement after retesting in normal-pressure hydrocephalus: a real change or merely a learning effect?" Journal of Neurosurgery 112, n. 2 (febbraio 2010): 399–409. http://dx.doi.org/10.3171/2009.4.jns081664.

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Object The test-retest method is commonly used in the management of patients with normal-pressure hydrocephalus (NPH). One of the most widely used techniques in the diagnosis of this condition is evaluation of the patient's response to CSF evacuation by lumbar puncture (a so-called tap test or spinal tap). However, interpretation of improved results in subsequent evaluations is controversial because higher scores could reflect a real change in specific abilities or could be simply the result of a learning effect. Methods To determine the effect of testing-retesting in patients with NPH, the authors analyzed changes documented on 5 neuropsychological tests (the Toulouse-Pieron, Trail Making Test A, Grooved Pegboard, Word Fluency, and Bingley Memory tests) and several motor ability scales (motor performance test, length of step, and walking speed tests) in a series of 32 patients with NPH who underwent the same battery on 4 consecutive days. The same tests were also applied in 30 healthy volunteers. In both groups, the authors used the generalized least-squares regression method with random effects to test for learning effects. To evaluate possible differences in response depending on the degree of cognitive impairment at baseline, the results were adjusted by using the Mini-Mental State Examination scores of patients and controls when these scores were significant in the model. Results In patients with NPH there were no statistically significant differences in any of the neuropsychological or motor tests performed over the 4 consecutive days, except in the results of the Toulouse-Pieron test, which were significantly improved on Day 3. In contrast, healthy volunteers had statistically significant improvement in the results of the Toulouse-Pieron test, Trail Making Test A, and Grooved Pegboard test but not in the remaining neuropsychological tests. Patients in the healthy volunteer group also exhibited statistically significant improvement in the motor performance test but not in step length or walking speed. Conclusions No learning effect was found in patients with NPH on any of the neuropsychological or motor tests. Clinical improvement after retesting in these patients reflects real changes, and this strategy can therefore be used in both the diagnosis and evaluation of surgical outcomes.

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Sergi, Rachele, Devis Bellucci, Roberta Salvatori e Valeria Cannillo. "Chitosan-Based Bioactive Glass Gauze: Microstructural Properties, In Vitro Bioactivity, and Biological Tests". Materials 13, n. 12 (23 giugno 2020): 2819. http://dx.doi.org/10.3390/ma13122819.

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Passive commercial gauzes were turned into interactive wound dressings by impregnating them with a chitosan suspension. To further improve healing, and cell adhesion and proliferation, chitosan/bioactive glass wound dressings were produced with the addition of (i) 45S5, (ii) a Sr- and Mg-containing bioactive glass, and (iii) a Zn-containing bioactive glass to the chitosan suspension. SEM and FTIR analyses evidenced positive results in terms of incorporation of bioactive glass particles. Bioactivity was investigated by soaking chitosan-based bioactive glass wound dressings in simulated body fluid (SBF). Cell viability, proliferation, and morphology were investigated using NIH 3T3 (mouse embryonic fibroblast) cells by neutral red (NR) uptake and MTT assays. Furthermore, the wound-healing rate was evaluated by means of the scratch test, using NIH 3T3. The results showed that bioactive glass particles enhance cell adhesion and proliferation, and wound healing compared to pure chitosan. Therefore, chitosan-based bioactive glass wound dressings combine the properties of the organic matrix with the specific biological characteristics of bioactive glasses to achieve chitosan composites suitable for healing devices.

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Ostendorf, David W., William G. Lukas e Don J. DeGroot. "Partially penetrating slug tests in an unweathered till layer". Hydrology Research 48, n. 1 (1 febbraio 2016): 117–32. http://dx.doi.org/10.2166/nh.2016.159.

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This research improves field based estimates of aquitard compressibility and permeability. A semianalytical model of partially penetrating, overdamped slug tests achieves this objective. The short term solution is an existing fully penetrating model, the long term solution is the polar residue of an inverse Laplace transform, and an exponential spline function patches the solutions together. Large amplitude slug test data from ten pairs of partially penetrating monitoring wells installed in an unweathered till at Scituate Hill in eastern Massachusetts calibrate the model. The deposit is bound by weathered till and the Dedham Granite fracture zone, and both are far more permeable than the unweathered till. The calibrated till permeability of 8.4 × 10–16 m2 is about 25% less than existing model calibrations that include boundary recharge in permeability values. The calibrated till compressibility of 5.1 × 10–10 Pa–1 reflects the proper inclusion of recharge as a long term source of groundwater, rather than the unrealistically large compressibility calibrations required by fully penetrating models.

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Abram, Katrin, Silvia Bohne, Peter Bublak, Panagiota Karvouniari, Carsten M. Klingner, Otto W. Witte, Orlando Guntinas-Lichius e Hubertus Axer. "The Effect of Spinal Tap Test on Different Sensory Modalities of Postural Stability in Idiopathic Normal Pressure Hydrocephalus". Dementia and Geriatric Cognitive Disorders Extra 6, n. 3 (27 settembre 2016): 447–57. http://dx.doi.org/10.1159/000450602.

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Background/Aims: Postural instability in patients with normal pressure hydrocephalus (NPH) is a most crucial symptom leading to falls with secondary complications. The aim of the current study was to evaluate the therapeutic effect of spinal tap on postural stability in these patients. Methods: Seventeen patients with clinical symptoms of NPH were examined using gait scale, computerized dynamic posturography (CDP), and neuropsychological assessment. Examinations were done before and after spinal tap test. Results: The gait score showed a significant improvement 24 h after spinal tap test in all subtests and in the sum score (p < 0.003), while neuropsychological assessment did not reveal significant differences 72 h after spinal tap test. CDP showed significant improvements after spinal tap test in the Sensory Organization Tests 2 (p = 0.017), 4 (p = 0.001), and 5 (p = 0.009) and the composite score (p = 0.01). Patients showed best performance in somatosensory and worst performance in vestibular dominated tests. Vestibular dominated tests did not improve significantly after spinal tap test, while somatosensory and visual dominated tests did. Conclusion: Postural stability in NPH is predominantly affected by deficient vestibular functions, which did not improve after spinal tap test. Conditions which improved best were mainly independent from visual control and are based on proprioceptive functions.

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McHenry, Megan S., Anna Roose, Emily Abuonji, Mark Nyalumbe, David Ayuku, George Ayodo, Tuan M. Tran e Aaron J. Kaat. "A psychometric evaluation of the NIH Toolbox fluid cognition tests adapted for Swahili and Dholuo languages in Kenyan children and adolescents". Journal of the International Neuropsychological Society 29, n. 10 (22 novembre 2023): 933–42. http://dx.doi.org/10.1017/s1355617723000632.

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AbstractObjective:Our objective was to evaluate the psychometric properties of the culturally adapted NIH Toolbox African Languages® when used in Swahili and Dholuo-speaking children in western Kenya.Method:Swahili-speaking participants were recruited from Eldoret and Dholuo-speaking participants from Ajigo; all were <14 years of age and enrolled in primary school. Participants completed a demographics questionnaire and five fluid cognition tests of the NIH Toolbox® African Languages program, including Flanker, Dimensional Change Card Sort (DCCS), Picture Sequence Memory, Pattern Comparison, and List Sorting tests. Statistical analyses examined aspects of reliability, including internal consistency (in both languages) and test–retest reliability (in Dholuo only).Results:Participants included 479 children (n = 239, Swahili-speaking; n = 240, Dholuo-speaking). Generally, the tests had acceptable psychometric properties for research use within Swahili- and Dholuo-speaking populations (mean age = 10.5; SD = 2.3). Issues related to shape identification and accuracy over speed limited the utility of DCCS for many participants, with approximately 25% of children unable to match based on shape. These cultural differences affected outcomes of reliability testing among the Dholuo-speaking cohort, where accuracy improved across all five tests, including speed.Conclusions:There is preliminary evidence that the NIH Toolbox ® African Languages potentially offers a valid assessment of development and performance using tests of fluid cognition in Swahili and Dholuo among research settings. With piloting underway across other diverse settings, future research should gather additional evidence on the clinical utility and acceptability of these tests, specifically through the establishment of norming data among Kenyan regions and evaluating these psychometric properties.

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Smith, Gabriel R., Roger D. Finlay, Jan Stenlid, Rimvydas Vasaitis e Audrius Menkis. "Growing evidence for facultative biotrophy in saprotrophic fungi: data from microcosm tests with 201 species of wood-decay basidiomycetes". New Phytologist 215, n. 2 (6 aprile 2017): 747–55. http://dx.doi.org/10.1111/nph.14551.

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Skelton, Robert P., Leander D. L. Anderegg e Laurent J. Lamarque. "Examining variation in hydraulic and resource acquisition traits along climatic gradients tests our understanding of plant form and function". New Phytologist 223, n. 2 (24 maggio 2019): 505–7. http://dx.doi.org/10.1111/nph.15893.

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Marmarou, Anthony, Marvin Bergsneider, Petra Klinge, Norman Relkin e Peter McL Black. "The Value of Supplemental Prognostic Tests for the Preoperative Assessment of Idiopathic Normal-pressure Hydrocephalus". Neurosurgery 57, suppl_3 (1 settembre 2005): S2–17—S2–28. http://dx.doi.org/10.1227/01.neu.0000168184.01002.60.

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Abstract OBJECTIVE: The diagnosis and management of idiopathic normal-pressure hydrocephalus (INPH) remains unclear. Moreover, the value of supplementary tests to predict which patients would benefit from placement of a shunt has not been established. This report develops evidence-based guidelines for the use of supplementary tests as an aid in prognosis. METHODS: MEDLINE searches from 1966 to the present were undertaken by use of the query NPH, normal-pressure hydrocephalus, lumbar drain, CSF [cerebrospinal fluid] tap test, and external CSF drainage in humans. This resulted in 242 articles. To provide a scientific, evidence-based review, we have chosen to restrict our analysis to clinically relevant studies usually consisting of large numbers of shunted NPH patients. Studies that did not specify INPH or secondary NPH were considered in a separate evidentiary table. RESULTS: Evidence-based guidelines for use in supplementary tests have been developed. A positive response to a 40- to 50-ml tap test has a higher degree of certainty for a favorable response to shunt placement than can be obtained by clinical examination. However, the tap test cannot be used as an exclusionary test because of its low sensitivity (26–61%). Determination of the CSF outflow resistance via an infusion test carries a higher sensitivity (57–100%) compared with the tap test and a similar positive predictive value of 75 to 92%. Prolonged external lumbar drainage in excess of 300 ml is associated with high sensitivity (50–100%) and high positive predictive value (80–100%). CONCLUSION: To date, a single standard for the prognostic evaluation of INPH patients is lacking. However, supplemental tests can increase predictive accuracy for prognosis to greater than 90%. Additional multicenter prospective randomized clinical trials are needed.

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Silva, Vitória Cunha, Mateus de Castro Dourado Torres, Rusllan Ribeiro de Paiva Ferreira, Lohahanne Yasmin Coelho Aguiar Lopes, Julião Jerônimo Leite Junior, Sara Mendonça Chahla, Monizy Eva Dantas Moreira et al. "ANÁLISE DA NEURALGIA PÓS-HERPÉTICA: UMA ABORDAGEM DAS MANIFESTAÇÕES CLÍNICAS E DIAGNÓSTICO". Revista Contemporânea 4, n. 4 (3 aprile 2024): e3590. http://dx.doi.org/10.56083/rcv4n4-009.

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Introdução: Este artigo oferece uma revisão abrangente da Neuralgia Pós-Herpética (NPH), enfatizando suas manifestações clínicas e diagnóstico. Além disso, estabelece a NPH como uma complicação debilitante decorrente da reativação do vírus Varicella-zoster, que persiste após a resolução do herpes zoster, destacando a importância de compreender suas manifestações para melhorar a qualidade de vida dos pacientes. Objetivo: Analisar detalhadamente as características clínicas e as estratégias diagnósticas da NPH, visando aprimorar o manejo e tratamento dessa condição. Metodologia: Essa revisão integrativa da literatura, foi realizada por busca em base de dados de artigos que correspondessem ao tema proposto. Incluiu-se avaliação dos artigos elegíveis na íntegra, excluindo aqueles que não se enquadram nos objetivos do estudo, teses e dissertações, sem contabilizar duplicatas. Resultados e Discussões: Ressaltam a variabilidade das manifestações clínicas da NPH, notadamente a dor em queimação, pruriginosa, aguda ou penetrante, e a presença de alodinia em mais de 90% dos pacientes. A análise revela que o diagnóstico de NPH se baseia primordialmente na persistência da dor por mais de três meses após um episódio de herpes zoster, na mesma distribuição dermatômica. A revisão também sublinha a importância da neuroimagem em casos atípicos e o papel limitado dos testes para anticorpos contra o vírus Varicella-zoster na confirmação diagnóstica. Conclusão: Enfatiza a complexidade da NPH, uma condição que desafia tanto o diagnóstico quanto o tratamento. O estudo destaca a necessidade de uma abordagem multidisciplinar e individualizada para o manejo da NPH, que não se limite apenas à terapia farmacológica, mas inclua também o suporte psicossocial. Além disso, identifica a necessidade de mais pesquisas para desenvolver estratégias de tratamento mais eficazes e menos invasivas, potencialmente melhorando significativamente a qualidade de vida dos pacientes afetados por essa condição crônica e debilitante.

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Nakahara, Yukiko, Yusuke Kodama, Shi Jie Zhu, Arimitsu Usuki e Makoto Kato. "Effect of Thermal Exposure on Tensile and Fatigue Properties of Clay Reinforced Nylon Nanocomposites". Materials Science Forum 833 (novembre 2015): 52–55. http://dx.doi.org/10.4028/www.scientific.net/msf.833.52.

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In this paper, both nylon 6 and 2 wt% clay reinforced nylon 6 matrix nanocomposite were used for thermal exposure tests at temperatures of 80 oC and 120 oC and 150 oC, respectively. Then, the tensile tests and fatigue tests of the exposed specimens were conducted at room temperature. It was shown that the tensile strength in both nylon 6 and NCH-2 decreased with an increase in thermal exposure temperature. The brittle fracture occurred in the specimens exposed at 120 oC and 150 oC. After pre-oxidation treatment at 80 °C for 100 hours, the fatigue strength decreased 14% in nylon 6, and 8% in NCH-2. From this result, it was understood that the addition of clay in nylon 6 could suppress the decrease of fatigue strengths.

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Schwarzschild, Michael, Guy Rordorf, Kaaren Bekken, Ferdinando Buonanno e Jeremy D. Schmahmann. "Normal-Pressure Hydrocephalus with Misleading Features of Irreversible Dementias: A Case Report". Journal of Geriatric Psychiatry and Neurology 10, n. 2 (luglio 1997): 51–54. http://dx.doi.org/10.1177/089198879701000202.

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An 85-year-old man presented with the clinical triad (gait instability, dementia, and bladder and bowel incontinence), the ventriculomegaly, and the normal CSF pressure that characterize normal-pressure hydrocephalus (NPH). Diagnostic uncertainty was raised by an unusually rapid onset and a lack of initial response to CSF tap tests. Additionally, periodic sharp waves on EEG suggested the possibility of Creutzfeldt-Jakob disease, and positron emission tomography (PET) demonstrated a pattern of cerebral hypometabolism typical of Alzheimer's disease. Nevertheless, the diagnosis of NPH was supported by delayed improvement following CSF tap tests, and it was confirmed by a dramatic clinical recovery after CSF shunting, resolution of the EEG and PET abnormalities, and a normal brain biopsy. NPH remains one of the few reversible causes of dementia, and the presence of its core features, regardless of rate of onset or ancillary test results, warrants careful consideration of therapeutic intervention.

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Ufuk Şahin, A. "Simple methods for quick determination of aquifer parameters using slug tests". Hydrology Research 48, n. 2 (11 maggio 2016): 326–39. http://dx.doi.org/10.2166/nh.2016.232.

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The slug test is still one of the simplest and cost-effective methods to interpret the hydraulic parameters for aquifer analysis. This study introduces two new estimation approaches for the slug test, the time shift method (TSM) and arc-length matching method (AMM), to identify aquifer parameters in a reliable and accurate manner, which was established on the idea that any change in the normalized drawdown or arc-length measurements of the data curve at the predefined drawdown levels is linked with the variation of storativity. These approaches remove the need for superimposition of the type curves and the field data. The proposed methods are straightforward to apply and automatize the parameter estimation process. TSM and AMM were tested with a number of numerical experiments including synthetically generated data augmented with random noise, hypothetical slug tests conducted in a heterogeneous rock-fracture system, and well-known real field data. The skin effect was also implemented to evaluate its impact on the estimation performance of the suggested approaches. The results verified that both proposed methods are able to produce estimates of hydraulic parameters more accurately than existing methods. The proposed methods could serve as a viable supplementary interpretation tool for slug test analysis.

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Condy, Emma E., Lindsey Becker, Cristan Farmer, Aaron J. Kaat, Colby Chlebowski, Beth A. Kozel e Audrey Thurm. "NIH Toolbox Cognition Battery Feasibility in Individuals With Williams Syndrome". American Journal on Intellectual and Developmental Disabilities 127, n. 6 (27 ottobre 2022): 473–84. http://dx.doi.org/10.1352/1944-7558-127.6.473.

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Abstract The NIH Toolbox Cognition Battery (NIHTB-CB) was developed for epidemiological and longitudinal studies across a wide age span. Such a tool may be useful for intervention trials in conditions characterized by intellectual disability (ID), such as Williams syndrome (WS). Three NIHTB-CB tasks, including two executive functioning (Flanker, Dimensional Change Card Sort) and one episodic memory (Picture Sequence Memory) task, were given to 47 individuals with WS, ages 4 to 50, to evaluate feasibility (i.e., proportion of valid administrations) in this population. Findings indicated that NIHTB-CB tests showed good feasibility. Flanker and DCCS age-corrected scores were negatively correlated with age and showed floor effects, indicating these scores may not be useful for quantifying performance on these NIHTB-CB tests in ID.

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