Search results for "Earing"
showing 10 items of 867 documents
Strength and Ductility of Hollow Circular Steel Columns Filled with Fibre Reinforced Concrete
1999
Publisher Summary This chapter investigates the behavior of hollow circular steel cross-sections filled with Fiber Reinforced Concrete (FRC), subjected to monotonic loads. The casting of different types of composite members—steel columns, steel columns filled with Normal Strength Concrete (NSC), and steel columns filled with Fiber Reinforced Concrete (FRC) was employed. The columns were tested in uniaxial compression utilizing a universal testing machine operating in displacement control. The maximum strength of composite members filled with FRC was 20% higher than that recorded for steel pipes filled with FRC. After the peak load was reached, failure was due to the crushing of concrete and…
The role of reading difficulties in the associations between task values, efficacy beliefs, and achievement emotions
2018
The aim of this study was to examine the situational associations of reading-related task values and efficacy beliefs with achievement emotions, and whether these associations are moderated by reading difficulties (RD). The sample comprised 128 Finnish sixth-grade students (66 with no reading difficulties [No RD], 31 with mild reading difficulties [Mild RD], and 31 with severe reading difficulties [Severe RD]) who were randomized to complete either a non-challenging or challenging reading task. Students reported their reading-related task values (attainment and interest) and efficacy beliefs right before and their achievement emotions both before and after performing the reading task. The r…
Training the Vertical Jump to Head the Ball in Soccer
2012
R esearchers involved in the training methodology to improve jump ability proposed a variety of techniques and exercise modalities (22,15,4). Nevertheless, the question on what percentage of training should be dedicated to strength and what to power seems unresolved. First of all, to better understand the matter, we have to stress the difference between strength and power. Generally speaking, in athletics, the rate of force development (RFD) is much more important than strength alone; the average RFD (mRFD) can be estimated as the ratio Fmax/Tmax, where Tmax is the time to reach the peak force, whereas Fmax is the maximum force. This ratio is also named explosive strength, commonly computed…
Diagnosis and therapy of vestibular schwannoma.
2009
MRI studies are of paramount importance for diagnosis and follow-up measurements during conservative and postinterventional management of vestibular schwannomas (VS). MRI findings that convey important information for hearing-preservation VS surgery are: length of tumor-cochlear nerve contact, involvement of the internal auditory canal, incomplete filling of internal auditory canal, tumor size less than 15 mm and the intralabyrinthine signal intensity on 3DFT-CISS gradient-echo images. Functional neuro-otologic studies of facial nerve function, hearing and vestibular/balance function provide a valuable means of assessment of the actual impairment of the functional status of the VS patient. …
Textbook of Vertigo: Diagnosis and Management
2013
Following you will find a brief description of the book done, as accorded with Alessandro De Stefano, to publish in Int Tinnitus J Vertigo: Diagnosis and Management of Jaypee Brother Publisher, is a new book in the field of vestibular disorders. This publication includes several topics ranging from anatomy of vestibular system to the rehabilitation after a vestibular disease. The book, edited by Dr. Francesco Dispenza and Dr. Alessandro De Stefano, had the contribution of about 30 Professors worldwide, experts in the fields of vertigo. The first part of the book includes the information about anatomy, physiology of vestibular system and general approach to the dizzy patients, with a window …
Intralabyrinthine neurinoma: Management, exeresis and auditory restoration with cochlear implant
2021
Abstract Background and objective Vestibular schwannoma is a benign tumour that originates in the eighth cranial nerve. It is termed intralabyrinthine schwannoma (ILS) when it develops in the inner ear, this being a rare origin. We present our experience in the management of three patients with ILS. Materials and methods The results of tumour excision and cochlear implantation were evaluated in three patients with ILS: two intracochlear schwannomas (ICS) and one intravestibular schwannoma (IVS). Results Prior to surgery, all patients presented progressive sensorineural hearing loss and tinnitus. Complete tumour resection and cochlear implantation was possible in all patients, with favourabl…
Rib-Roller Wear in Tapered Rolling Element Bearings: Analysis and Development of Test Rig for Condition Monitoring
2020
Rolling Element Bearings (REBs) are present in virtually all machines with moving or rotating parts, and are vital for proper performance and safe operation. Condition Monitoring (CM) of bearings often receive particular interest, as this component group rarely reach design lifetime and hence is responsible for unplanned machine downtime. Unplanned maintenance can represent a large cost which motivates development of improved CM methods for implementation of advanced maintenance regimes. Based on observations of a used bearing from an offshore drilling machine, wear on roller ends in the rib-roller contact area was identified as an area of interest for future research. A test rig for creati…
Observation and Processing of Instantaneous Frequency Variations During Bearing Tests
2020
Laboratory experiments have been performed on medium sized roller bearings with two levels of artificial damage. Recordings of long time series from accelerometers at a wide range of different radial loads and rotation speeds has been performed. Probably due to non-perfect performance of the control systems for the rotational speed or frequency, significant fluctuations were observed at all rotation speeds. The highest relative variation was observed at the lowest rotational speeds. These variations were recorded using a rotary encoder, which allows order tracking of the vibration signal. In real life condition monitoring, tachometers or rotary encoders are not always present, this can be d…
Detection of Incipient Bearing Fault in a Slowly Rotating Machine Using Spline Wavelet Packets
2018
This chapter describes a successful application of spline-based wavelet packet transforms (WPTs) described in Chap. 4 to a complicated problem of detection of incipient defects in rolling element bearings by the analysis of recorded vibration signals. The methodology presented in this chapter is applied to the analysis of vibration data recorded from large bearings working in real unfavorable operation conditions in presence of strong noise and vibrations from multiple internal and external sources. It relies on properties of discrete spline-based wavelet packets such as orthogonality, near-rectangular spectra, transient oscillating shapes of testing waveforms and fast implementation of tra…
Vitamin A deficiency increases noise susceptibility in guinea pigs.
1990
The effect of vitamin A deficiency in guinea pigs on noise-induced temporary threshold shift (TTS) was evaluated after short (15 min) acoustic overstimulation with a moderate (90 dB) broad-band white noise. Some guinea pigs were fed ad libitum a purified diet deficient in vitamin A (VAD group) until biochemical signs of deficiency occurred. A second, control group (VA group) received the same diet as well as 100 IU vitamin A daily by pharyngeal tube. Cochlear potentials were recorded by special computerized equipment using implanted electrodes. Before acoustic stimulation, a baseline value was determined with a test stimulus [90 dBA (A-filter according to usual DIN instructions)] correspond…