Apparatus and method for measuring the Barkhausen signal of a moving magnetic film, ribbon or fiber wherein first and second stationary electromagnet coils are arranged and separated by a distance, d, along the path of movement of the film, ribbon or fiber. The first and second coils are energized in a manner to generate first and second opposing DC magnetic fields through which the moving film, ribbon or fiber passes along its path of movement. As the film, ribbon or fiber moves through the first and second opposing magnetic fields at a velocity, v, it experiences one complete cycle of magnetization in a period of time equal to d/v. A stationary third signal pick-up coil is disposed between the first and second coils to detect the Barkhausen signal from the moving film, ribbon or fiber. The pick-up coil typically is disposed midway between the first and second coils where the Barkhausen signal will be approximately maximum.
A method and apparatus for electronically driving an ultrasonic acoustic transducer. The transducer is operable in two modes; in a first mode, the lock-in frequency of the transducer is determined; in a second mode, the lock-in frequency determined in the first mode is used to modulate a tone-burst pulse to drive the transducer in an efficient manner. Operating in the first mode, the lock-in frequency is determined by exciting the transducer with a series of tone bursts, where each tone burst comprises an electronic pulse modulated by a tone of one frequency selected from a range of frequencies, and measuring the response of the transducer to each tone burst. In an alternative embodiment, the excitation of the transducer in the first mode is provided by a signal whose frequency is swept over a range. The response of the transducer is sampled at various times during the sweep. The lock-in frequency is chosen by examining the responses and choosing the frequency which gives the best response. Operating in the second mode, the transducer is driven with an electronic tone burst generated by modulating said an electronic pulse with a tone of the determined lock-in frequency.
A method and apparatus for enabling analysis of a flowable material enclosed in a transport system having an infrared transparent wall portion. A temperature differential is transiently generated between a thin surface layer portion of the material and a lower or deeper portion of the material sufficient to alter the thermal infrared emission spectrum of the material from the black-body thermal infrared emission spectrum of the material, and the altered thermal infrared emission spectrum is detected through the infrared transparent portion of the transport system while the altered thermal infrared emission spectrum is sufficiently free of self- absorption by the material of emitted infrared radiation. The detection is effected prior to the temperature differential propagating into the lower or deeper portion of the material to an extent such that the altered thermal infrared emission spectrum is no longer sufficiently free of self-absorption by the material of emitted infrared radiation. By such detection, the detected altered thermal infrared emission spectrum is indicative of characteristics relating to molecular composition of the material.
An apparatus, method, and system for distributing gas and/or liquid phase substance from an inlet to multiple outlets with reduced variations and distribution. The apparatus includes a body having an inlet and a plurality of outlets. In one aspect, a rotatable impeller is positioned between inlet and plurality of outlets. The impeller includes a spiral fluid pathway relative to direction of substance through the inlet so that the substance passes through the impeller and is distributed to the outlets through a spinning impeller.
some sections during simulate vacuum preloading me- thod, pre-consolidation (AB), vacuum application (BC), surcharge loading (CDEF). Under vacuum condition, the stress path of soil moves from B to C far from the failure line, while it changes from D to E close to the failure line when surcharge was applied. The behavior of soil speci- men under vacuum preloading method simulated by Tri-axial apparatus is well matched the before studies.
A method and apparatus for enabling analysis of a solid material (16, 42) by applying energy from an energy source (20, 70) top a surface region of the solid material sufficient to cause transient heating in a thin surface layer portion of the solid material (16, 42) so as to enable transient thermal emission of infrared radiation from the thin surface layer portion, and by detecting with a spectrometer/detector (28, 58) substantially only the transient thermal emission of infrared radiation from the thin surface layer portion of the solid material. The detected transient thermal emission of infrared radiation is sufficiently free of self-absorption by the solid material of emitted infrared radiation, so as to be indicative of characteristics relating to molecular
A method and apparatus for enabling analysis of a material (16, 42) by applying a cooling medium (20, 54) to cool a thin surface layer portion of the material and to transiently generate a temperature differential between the thin surface layer portion and the lower portion of the material sufficient to alter the thermal infrared emission spectrum of the material from the black-body thermal infrared emission spectrum of the material. The altered thermal infrared emission spectrum of the material is detected by a spectrometer/detector (28, 50) while the altered thermal infrared emission spectrum is sufficiently free of self-absorption by the material of the emitted infrared radiation. The detection is effected prior to the temperature differential propagating into the lower portion of the material to an extent such that the altered thermal infrared emission spectrum is no longer sufficiently free of self-absorption by the material of emitted infrared radiation, so that the detected altered thermal infrared emission spectrum is indicative of the characteristics relating to the molecular composition of the material.
The invention discloses an improved bone conduction sensor capable of use within a voice sound transmitting apparatus. The bone conduction sensor is adapted for placement in the external auditory canal of the user in a nonocclusive fashion. The bone conduction sensor has a contoured surface adapted-to fit against a wall of the external auditory canal increasing the surface area contact between the bone conduction sensor and the wall of the external auditory canal. The bone conduction sensor may also be associated with one or more contact sensors adjacent the bone conduction sensor for determining contact between the bone conduction sensor and the wall of the external auditory canal. In addition, the invention provides for the bone sensing element to be separated from the circuit portion of the bone conduction sensor so that the circuitry may be removed to the behind the ear portion of the earpiece.
Heat fluxes q were calculated from the temperature gradients in the heated block, which means, that they are based on average temperatures measured by thermocou- ples. Due to possible heat conduction in horizontal di- rection actual reached heat fluxes could be di ff erent from those, that were calculated. It would be useful to compare heat fluxes obtained with this method and those measured for example with wattmeters connected to supply wiring.
Among the absolute methods the guarded hot plate is the most widely used and precise method for determining the thermal conductivity on the range of interest and has been adopted by American Society for Testing and Materials as a Standard Method . The name refers to an arrangement to prevent heat leaving the system through the edges of the sample. The basic guarded hot plate apparatus consists principally of a hot plate and a cold plate. The hot plate consists of a central or metering heater plate surrounded by an outer or guard heater plate with a small air gap in between. Outside of specimen is a metal plate known as cold plate, which maintains a temperature below that of the hot plate by circulating a fluid. The function of the metering heater is to produce the heat flux necessary to maintain a desired temperature gradient across the central measuring area of the specimen. The guard heater maintains a temperature close to the metering area to reduce radial heat flow from metering section of heater plate and specimen . The conductivity of the specimen is calculated from the temperature difference of the central and cold plate, thickness of the specimen and the electrical heat input to the metering section of the central plate. The accuracy of the conductivity measurements in the conventional guarded hot plate apparatus depends on the maintenance of steady uniform temperature conditions (ΔT) and accurate evaluations of the measured quantities (s ). Another important factor is the balancing of temperatures across the gap between sample and hot part . Thus, to design thermal conductivity measurementapparatus, the absolute consideration aspect are how to control heat losses to surrounding and problem related on heat flux because both of this influencing the performance of apparatus.
The surface tension of water under both stable and metastable supercooled state evaluated from equation (2) is shown in figure 8. Preliminary data agree relatively well with the IAPWS correlation (1) extrapolated to subzero temperatures and consequently also to our previous results obtained with the capillary elevation method [9,10]. The estimated standard combined uncertainty of the measured surface tension is approximately 1.5 times higher than for previous measurements (around ± 0.40 mN m -1 at – 4 °C in ) as it increases from ± 0.59 mN m -1 at + 40 °C to ± 0.63 mN m -1 at − ° 7 C . Main reason is rather high uncertainty of the evaluated helium overpressure which shall be improved in future. As can be seen in figure 8, the IAPWS correlation lies within the uncertainty range for most of the measured data points.
Design of the experimental apparatus allows its modification also for measurement of surface tension for supercooled water on the basis of a method developed by Hacker . In this case, the liquid thread is located inside a short horizontal capillary tube whose one end is connected to the setup allowing pressure variation. The second end of the tube is opened to the ambient. The surface tension of investigated liquid can be evaluated from the pressure required for flattening the liquid meniscus at the opened end of the capillary tube.
The main measuring principle is determination of the ratio of a density of supercooled water U L at temperature T L to density of stable liquid water U H at temperature T H at the same pressure. Water is enclosed in fused-silica capillaries with an internal diameter diameter of about 0.3 mm, sealed at one end. The position of the meniscus is measured with a camera equipped with a telecentric lens. In order that the measurement at high pressure is possible, the glass capillaries are enclosed in a stainless steel tube of outer diameter 6.35 mm. The menisci are located in an optical cell. The observed length of the capillaries is about 20 mm. The temperature of the stainless steel tube containing the capillaries is switched between the “low temperature” T L and the “high temperature” T H with help of a heat transfer fluid (ethanol) flowing along the outer surface of the tube. Because the optical cell is a massive part, its temperature cannot be changed quickly. Therefore, its temperature is maintained at the high temperature T H . In order to eliminate the influence of the transition between the two temperatures, a compensation method using two capillaries of different length was introduced. As shown in Figure 1, the Figure 1: Scheme of measurement with two capillaries of different
abstract: The paper deals with the analysis of the operation of a hen feeding line in the reproduction breeding hall at the floor stabling type combined with the deep bedding on grates. We have measured the hen feeding line operation time in accordance with STN 47 0120, the losses of the fodder spilled by hens during a single feeding and the consumption of electricity of the observed line. As a result of the failure to carry out regular technical maintenance of the line as a preventive measure against the origin of defects, a relatively low value of the productive time use coefficient (0.77) was detected. Based on the analysis of the consumption of electric power, the electric engines driving individual segments of the line were found to be correctly dimensioned. Using the monitored technology, we managed to record excessive losses of the spilled feed mixture from the chain trough. For the whole farm it represents up to 702.8 kg of feedstuff per a day. The detected losses are very negatively projected into the economy of the production of one-day chickens. A negative and statistically highly conclusive correlation coefficient (r = –0.9230**) was recorded between the chickens age and the losses of feed.
Figure 3.12 shows the processing times of the algorithms as a function of the win- dow size. The processing time is the time required for the algorithm to re-calculate capacity. The processing time is seen to be related to N for CEB and NEB, with a complexity of O(N 2 ). This result is in parallel with our expectations. CEB and NEB calculate autocor- relations of measurements falling into the measurement window of size N , and this requires a processing time proportional to N 2 . Whereas, GA uses only the mean and variance of the measurements, whose calculations are fully on-line. As a result, GA has complexity of O(1) and regardless of N, its execution time remains much smaller compared to other algorithms.
Telecom Egypt Company (TE) is the unique fixed telephone line company in Egypt. Due to the huge demand for high data rates for personals and companies, the performance of the copper network needs to be evaluated to assess its capability for transmitting high data rates to meet the increased demand on data transmission. The most commonly used testing and measuring instrument in TE is “Dynatel 965DSP”, which has some drawbacks.
Models which describe the Barkhausen effect over the entire hysteresis loop have been proposed by Sablik and Au- gustymak 2 and Jiles, Sipahi, and Williams 3 共 JSW 兲 and sub- sequently developed further. 4,5 This latter model assumes that the rate of irreversible change in magnetization is pro- portional to the level of Barkhausen activity in a given time interval. While not explicitly stated, this implies that the Barkhausen signal is the result of a linear combination of many individual events occurring at different locations within in the material. In order to account for the random nature of the Barkhausen effect, it was suggested that the number of Barkhausen events in a given time period N(t n ) is related to the to the number of events in the previous time period N(t n ⫺ 1 ) by some random increment. This increment