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 thermalinfrared emission spectrum of the material from the black-body thermalinfrared emission spectrum of the material, and the altered thermalinfrared emission spectrum is detected through the infrared transparent portion of the transport system while the altered thermalinfrared 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 thermalinfrared emission spectrum is no longer sufficiently free of self-absorption by the material of emitted infrared radiation. By such detection, the detected altered thermalinfrared emission spectrum is indicative of characteristics relating to molecular composition of the material.
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 thermalinfrared emission spectrum of the material from the black-body thermalinfrared emission spectrum of the material. The altered thermalinfrared emission spectrum of the material is detected by a spectrometer/detector (28, 50) while the altered thermalinfrared 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 thermalinfrared emission spectrum is no longer sufficiently free of self-absorption by the material of emitted infrared radiation, so that the detected altered thermalinfrared emission spectrum is indicative of the characteristics relating to the molecular composition of the material.
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 transientthermal emission of infrared radiation from the thin surface layer portion, and by detecting with a spectrometer/detector (28, 58) substantially only the transientthermal emission of infrared radiation from the thin surface layer portion of the solid material. The detected transientthermal 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
In this paper an original solution of a small capacity infrared dryer for home use for drying biological material is given. The dryer is transportable, with small dimensions and is characterized by a cylindrically shaped drying chamber. An infrared heater is placed in the center of the dryer. Five vertical cylinders with perforated walls for placing material in the drying process are positioned around the heater. Due to the construction of the mechanical transporter in the drying process the cylinders rotate around their vertical axis, thus leading to more uniform heating of the material volume and a stage radiation regime. The dryer dimensions are: maximal width 320 mm and height 450 mm. The dryer capacity of moist material is around 2.5 kg. In the paper has defined the mathematical models for analysis of the influence of the material types, shape and dimensions of the surface undergoing on the drying process. Based on analytical equation, defined of the mathematical models, and drying kinetics were defined based on experimental results drying process of apples in infrared and convective dryer small capacity, gives the graphical dependence and corresponding analysis.
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.
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.
From the combination of the analysis of the infrared spectra, which provides insight into the orientation of different functional groups in the thin film, and the XRD pat- tern, which shows a lack of crystallinity in the film, we have obtained a picture that the short axis of the thiophene ring is parallel to the surface, whereas the long axis is nearly disordered.
Abstract. The calibration of uncooled thermalinfrared (IR) cameras to absolute temperature measurement is a time-consuming, complicated process that significantly influences the cost of an IR camera. Temperature- measuring IR cameras display a temperature value for each pixel in the thermal image. Calibration is used to cal- culate a temperature-proportional output signal (IR or thermal image) from the measurement signal (raw image) taking into account all technical and physical properties of the IR camera. The paper will discuss the mathemat- ical and physical principles of calibration, which are based on radiometric camera models. The individual stages of calibration will be presented. After start-up of the IR camera, the non-uniformity of the pixels is first corrected. This is done with a simple two-point correction. If the microbolometer array is not temperature-stabilized, then, in the next step the temperature dependence of the sensor parameters must be corrected. Ambient temperature changes are compensated for by the shutter correction. The final stage involves radiometric calibration, which establishes the relationship between pixel signal and target object temperature. Not all pixels of a microbolome- ter array are functional. There are also a number of defective, so-called “dead” pixels. The discovery of defective pixels is a multistep process that is carried out after each stage of the calibration process.
Additionally, the NLIS system is experimentally demonstrated for target identification using the acquired interferograms directly, without calibrating the interferograms to the spectral domain. This process was implemented using both expectation maximization and neural networks, and the target discrimination performance of each was compared. As a basis for comparison, data from an outdoor scene containing combusting model rocket engines was used. Similar to the previous chapter, the neural network approach provides superior results. Specifically, it is demonstrated that the neural network approach eliminates cross-talk that the expectation maximization approach suffers from. For additional sensor validation, a conventional spectral calibration is performed using expectation maximization. This method is then validated on a laboratory scene.
The analytical radiation impedance expressions of pulsating sphere sound sources in the free field and closed space are derived in this paper. The radiation impedance of a pulsating sphere sound source is calculated using the proposed numerical method. The correctness is verified by the analytical procedure. The research shows that the numerical model of the radiant impedance established by Actran is suitable for the calculation and analysis of the acoustic impedance characteristics of underwater sound sources. The numerical method established in this paper provides a useful numerical method for the analysis the impedance characteristics of underwater sound sources with complex geometric structures.
A circular metal rod of approximately Φ 50mm x 25mm in vertical dimension is machined and lightly polished to achieve flat surfaces. The surfaces other than the top are thermally insulated with low thermal conductivity material (wooden block with Glass wool insulation around the specimen).As maximum diameter used so heat transfer rate is also maximum. Used metals Aluminum alloy, Copper, Brass, Iron, at 27 0 c Atmospheric
which does not fundamentally differ for temperatures re- sulting from initialized model runs. The latter, however, are lower for the entire thermal field and all GST histories used. 0 ◦ C and −3 ◦ C-isotherms of temperature fields ini- tialized with different GST histories are compared to sta- tionary conditions with current GST in Fig. 3: According to the definition of permafrost, the 0 ◦ C isotherm stands for the schematic permafrost boundary in the idealized mountain ridge, whereas the − 3 ◦ C isotherm relates to the temperature distribution inside the schematic permafrost body. The re- sulting temperature depressions from the last Ice Age (1) is in the range of − 0.5 ◦ C for the upper half of the geometry, and in the range of − 2.5 ◦ C for the lower part. When assum- ing colder GST in the last Ice Age (2) these values amount to − 1 ◦ C and − 4 ◦ C, respectively. Simulating the GST vari- ations during the Holocene (4) results in additionally lower temperatures: On the one hand, the LIA (5) is perceivable down to about 250 m depth. On the other hand, deeper parts are modeled colder because (1) and (2) do not consider that present-day GST are somewhat higher than Holocene aver- age. The effect of the HCO (3) is below 0.1 ◦ C for the entire geometry, and results are therefore not displayed in Fig. 3. Results for GST history (6) do not notably differ from (5) and are not shown, either. Based on the results from (1) to (6), we compiled GST history (7), which accounts for the variations for which a significant influence was shown above. Although we use highly idealized conditions in the experiments, it can be assumed that these are the most important variations that influence the subsurface thermal field in high mountains, be- cause thermal properties and size of the major part of Alpine topography does not essentially differ from the geometries used: We considered the cold temperatures during the last Ice Age (1) and the major fluctuations in the past millennium (4). GST history (7) is used for all subsequent calculations in this study and corresponding temperature fields are referred to as “initialized” or “transient”.
For the most part, as thermographers, we know we sometimes need to create a thermal delta to enhance or even obtain a thermal image. We call this Active -IR. It seems that there is a whole industry growing up around us, and maybe through us, that has a whole different concept as to what Active-IR is. 1
By carrying out an analysis and experiments on the piston , and depending on the principle of cooling piston with oil in order to permit the piston to carry more thermal loads without having more damages with increasing the engine speed rate . And there are two types of pistons according to the cooling case , the first type is the piston with the cooling gallery in which the cooling oil is passed , and the second type is the solid piston where the cooling is limited to the under crown surface only.
Finite Element Analysis (FEA) is a computer-based numerical technique for calculating the strength and behavior of engineering structures. It can be used to calculate deflection, stress, vibration, buckling behavior and many other phenomena. It also can be used to analyze either small or large scale deflection under loading or applied displacement. It uses a numerical technique called the finite element method (FEM).
The primary focus of the research is to evaluate the use of static beds of ceramic particles as a thermal energy storage device for power generation applications. Two lab-scale heat exchanger setups were designed based on full-scale CSP plant requirements for running the experimental investigations on the proposed systems. Computational Fluid Dynamic (CFD) simulations are used to complement the experimental data as well as to design and modify proposed systems. Furthermore, a simple lumped analysis was conducted to validate the simulation models as well as to theoretically predict the performance of these particulate systems.
Now a days the synthetic fibre composites are replaced by environment friendly materials such as natural fibre like wood,banana, cotton, coir, sisal, jute etc. because natural fibre composites posses better electrical resistance, good thermal and acoustic insulating properties and higher resistance to fracture. In addition, natural fibres have many advantages over synthetic fibres, for example low weight, low density, low cost, acceptable specific properties, renewable and have relatively high strength and stiffness and cause no skin irritations. A better understanding of their physical properties, mechanical and thermal behaviors will enable engineers to produce optimum design for a structure. The thermal conductivity of a composite depends upon the thermal conductive nature of the fibre, matrix properties as well as their volume fractions, sizes, shapes, thickness, orientations and perfect bonding between the constituents. In
The heat transfers mainly depend on the frequency of grain contacts, size of pores and air – water ratio infilling the porosity. The moisture transfers mainly depend on the connectivity associated to the meso – to – microporosity distribution and especially on the microporosity of the clay matrix in clay dominant materials.
In the present paper we intend to show that a new type of solar chimney technology that we shall heretofore call “Enclosed Solar Chimney Power Plant” (ESCP) technology stands for an effective alternative capablity of combining both low generation cost as well as smooth, uninterrupted operation for 24 hours/day and for all 365 days/year. This is achieved with the introduction of a low cost artificial water storage facility which can always be constructed on ground near the base of the solar chimney structure and protected by external winds.