Airflow Method Research Articles

247高速度カメラとDP法を用いた高速気流の三次元計測

Dynamic programming matching technique, which is used for the voice recognition, has been adopted to the time line images obtained by the spark tracing method for the high speed air flow. As the high voltage sparks between two electrodes trace the air flow very well, we can measure the two or three-dimensional air velocities, if we can quantify the displacement and the time interval between sparks. With the dynamic programming matching technique, the characteristics of the two consecutive spark lines are nicely corresponded and thus the three-dimensional displacement between sparks are quantified. Presently, the high speed air jet has been measured with this technique.

Defrosting of automotive windshields: progress and challenges

Climate control applications are of great interest to the automotive industry. The issue of windshield defrosting has received, and continues to receive, considerable attention from various investigators around the world. This paper presents an up-to-date assessment of our knowledge base on defrosting. It documents a comprehensive literature review covering experimental as well as computational efforts, accompanied by utilisation of electric heating elements, conducting films, and heat storage devices. The paper also presents a list of measurement methods for airflow and thermal patterns pertinent to defrosting. It concludes with an example on quick detection of a defroster system performance, recommends a defroster system development sequence, and addresses relevant future challenges.

Determining fiber fineness in flax using derivative thermogravimetric analysis, scanning electron microscopy, and airflow methods

This study investigates the assessment of fiber fineness by a range of techniques. Conventional airflow and gravimetric methods were compared with derivative thermogravimetric analysis (DTG). The novel use of scanning electron microscopy (SEM) for examining fiber cross-sections has also been deployed. DTG analysis when compared with airflow measurements has shown that differences in fiber fineness can be modeled from the pyrolysis data. The relationship between the two methods was highly significant. The diameter of the fiber cross-sections, measured from SEM micrographs, revealed a significant relationship with both DTG and airflow measurements. Gravimeteric determinations exhibited a poor correlation with the other methods and have shown an inability to distinguish between fibers of similar grades. The use of DTG for predicting fiber fineness was validated using partial least squares regression on a test set of samples. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 508–514, 2000

Review: Assessment and Staging of Nasal Polyposis: Introduction

This paper deals only with “simple” nasal polyposis which is almost always found in both cavities of the nose. A computer-based questionnaire will be described. Objective methods are described, i.e. rhinostereometry, acoustic rhinometry, rhinomanometry, and nasal peak flow, and their value in estimating changes of the size of nasal polyps discussed.To assess means, according to dictionaries, to estimate the value of something as a basis for taxation. The assessment of nasal polyposis may thus include not only aspects such as localization, size or volume, shape, colour, histologic appearance etc., but also aspects such as symptoms and effects of treatments. This review will focus on questionnaires, nasal patency and nasal airflow methods, and on staging, and omit assessment of symptoms and treatment, and furthermore of techniques for nasal lavages or other ways to collect secretion and the evaluation of mediators, markers and cells, the latter having been thoroughly described in a recent review in Acta Oto-Laryngologica (1).

Simulation of Coffee Drying in a Fixed Bed with Periodic Airflow Reversal

The deep-bed drying model developed by Thompson et al. for yellow-dent shelled maize was modified to investigate the drying of natural coffee in a fixed bed with periodic airflow reversal. Simulations were also carried out for the conventional one-direction airflow drying method. Data obtained experimentally by one of the present authors (Berbert) was used to validate the model. Two equilibrium moisture content equations are discussed in view of their relevance to accuracy of coffee drying simulation and equations expressing enthalpy of vaporization, specific heat and bulk density as a function of coffee moisture content are also given.The differences between experimental and predicted values of coffee moisture content and drying air temperature were within limits generally accepted for current validation of drying models. At a drying air temperature of 50°C, the mean value of differences between experimental and predicted moisture contents was 0·020 decimal d.b. The standard deviation of the differences was 0·010 d.b. with a worst-case error of 0·037 d.b. The mean value of differences between predicted and measured temperatures was 2·4°C, with a standard deviation of 1·4°C. The influence of temperature and reversing-time interval on specific energy consumption and final moisture content difference throughout the coffee bed were investigated. Based on simulation results, it was found that the reversing-time interval had a negligible effect on specific energy consumption as compared with the conventional drying method for all drying air temperatures studied. A considerable improvement in uniformity of the final moisture content was achieved by applying the reversed direction airflow drying method. Conventional coffee drying at 50°C produced a final moisture content difference of 0·041, decimal d.b, while the moisture differences associated with the reversed direction airflow method varied from 0·011 d.b. to 0·015d.b., depending on the reversing time interval.

Drying of Coffee (Coffea arabica L.) in a Fixed Bed with a Simulated Periodic Airflow Reversal

Reversing the airflow at regular intervals throughout the drying period of coffee in a fixed bed has been proposed as a feasible method of reducing the final moisture content difference throughout the bed depth. The drying curves of six individual sections and the time-temperature history of the drying air at seven evenly spaced points in a total bed depth of 0·90 m were investigated. Tests were conducted using two levels of reversing-time interval, 3 h and 6 h, two levels of drying air temperature, 50°C and 70°C, and an airflow rate of 15 m3 min-1 m-2. Comparative tests were performed using the conventional one-direction airflow drying method. Reductions in final moisture content difference ranging from 65 to 73% were observed by reversing the airflow direction every 3 or 6 h for drying air temperature of 50°C as compared to the conventional drying method. However, for drying air temperature of 70°C and 3 h reversing-time interval, despite reductions of up to 67% in the final moisture content difference, non-uniformity of the moisture distribution was still quite severe. The reversed direction airflow drying method was used to reduce moisture content from 0·33, decimal d.b. to 0·16 d.b., by increasing the inlet drying air temperature from 50 to 70°C. It was found that the final moisture content difference was reduced on average from 0·044 to 0·013 d.b. versus 0·078 to 0·026 d.b., respectively, when compared to the conventional one-direction airflow method.

New Findings in Observations by Tubo-tympano-aerodynamic Method

We studied Eustachian tube function of healthy adults by two air flow methods, namely tubo-tympano-aerodynamic graphy by Valsalva maneuvre, and Tyonbee maneuvre during swallowing. We observed for the first time the presence of reciprocal features in normal Eustachian tubes. We also compared the tubal function of the same group using an air flow method and sound transmission method. The results of these observations showed that 77.4% of the subjects were positive for TTAG in Valsalva pattern, and 85.4% for sonometry. It can be inferred that data on the tubal opening in response to Valsalva and Toynbee maneuvres is obtained more easily by sonometry than by TTAG. TTAG, which permits examination of minute changes in air flow dynamics even in healthy Eustachian tubes, provides more important information on tubal function than does sonotubometry.

Measurement of resistance to respiration by the interrupted air flow method

1. The interrupting device must be located between the mouthpiece and the pneumotachometric tube.

Relationship of staple strength and other fleece characteristics of Romney wool to fibre length after carding

Abstract The prediction of length-after-carding parameters (especially barbe) by several fleece characteristics was examined with wool from 58 non-pregnant Romney ewes. During the winter, the sheep were housed indoors in five groups which were fed at different levels of nutrition in an attempt to increase the variation in staple strength. However, only the group fed at the lowest level (submaintenance) showed any major effect. Considerable variation in staple strength occurred within the groups. About 61 % of the variation in barbe was explained by a regression equation based on staple length, the staple strength of midside wool, and the mean fibre diameter determined by the air-flow method. Bulk, greasy, and clean fleeceweight, and the position of break in the staple did not improve the prediction. A marginal improvement resulted when air-flow fibre diameter was replaced by minimum diameter determined from monthly midside clippings. No major variations were found in the prediction equation as a result of using different staple strength measurements or using wool from other body positions.

Simulation Model for Reversing Direction Airflow Drying of Rough Rice

ABSTRACT THE Michigan State deep-bed drying model for cereal grains was modified and utilized to investigate rough rice drying in a small fixed-bed dryer. Comparisons were made between reversing direction airflow and one direction airflow drying method. The optimal reversed time interval was found to be approximately 54 percent of the total drying time required for one direction airflow method. The simulation results indicated that the reversing direction airflow significantly reduced the final grain moisture gradient. However, the energy consumption increased up to 10 percent and the drying efficiency was slightly lower for reversing direction airflow as compared to one direction airflow drying.

Determination of Fineness and Maturity of Cotton by Air-Flow Methods

Certain basic relations between the cross-sectional parameters of the cotton fiber have been obtained and their direct application for determining the cotton fineness and maturity explained. These may be used, with advantage, in place of the empirical relations derived from the values of various cross-sectional parameters physically measured on selected cotton types and currently used for estimat ing the fineness and maturity of cotton by air-flow methods.

An alternate method of recording airflow during sleep.

Respiratory activity recordings in polysomnographic recordings are important in the identification of the sleep apnea syndrome. However, simultaneous recordings of both respiratory effort and airflow are necessary to accomplish this identification. We describe a relatively inexpensive and trouble-free face mask that makes use of a linear thermistor in the ventilation tube to accomplish the recording of airflow in a noninvasive manner.

Comparisons of Determinations of Wool Fiber Diameter by Two Airflow Methods

Abstract Sixty scoured wool core samples were measured for fiber diameter by three different methods. Mean diameters of the samples were determined by the projection microscope method and used to place each sample in one of six classes. The interval of each class was 2.5 μm; diameters ranged from 17.5 to 32.5 μm. The specimens, first uncarded and then carded, were next measured on the Port-Ar® and the Wool Industries Research Association Fibre Fineness Meter®. Carding of the samples prior to measurement was concluded to be unnecessary as no significant differences were found (P < 0.05) between results. This was true for both airflow methods. Regression and correlation coefficients of one airflow method versus the other were significant (P < 0.01). Based on the regression analysis, it was concluded that a conversion from one airflow method to the other may be acceptable. Confidence limits at the 99% probability level for such conversions are not greater than ± 1 μm.

Relationship of Some Fiber Properties with Yarn-Strength Parameters of Jute

Jute fiber properties commonly determined are strength and fineness. The relationship of these fiber properties with the various yarn-strength parameters are discussed. Though fiber bundle strength is closely associated with yarn tenacity, it does not explain satisfactorily the variation in yarn quality. Fineness measured by the air-flow method does not show significant correlation with yarn tenacity.

The Effect of the Ellipticity of Fibres on Diameter Measurement by the Air-flow Method

The Effect of the Ellipticity of Fibres on Diameter Measurement by the Air-flow Method

Studies on CO<SUB>2</SUB> Uptake and CO<SUB>2</SUB> Evolution in Each Part of Crop Plants : II. Photosynthetic activity in the leaf sheath and ear of rice plant

Leaf sheaths and ears of rice plants have been classified as non-photosynthetic organs on the growth analysis method, but their tissues have chlorophyll as photosynthetic element. The purpose of this paper is to evaluate the activity of CO2 uptake of their parts in more detail on dry matter production. Furthermore, one has to point out the physiological factors related to that photosynthetic activity. Using an open system of gas analysis (air flow method), it was found that CO2 uptake and CO2 evolution in light and in darkness from the upper and lower parts of leaf sheaths and ears for potted rice have a different response to light intensities. I. Maximum rate of net photosynthesis per exposed surface of the leaf sheath and the rear were 3 and 1∼2mgCO2/dm2(100 spikelets)/hr respectively, and the light saturation point was about 40 Klux on vigorous organs. Gross photosynthetic rate and saturation point were decreased along with the discoloring of green on their organs. 2. Changes of the gross photosyntheis of ears with elapsed time showed the trend of a close parallel to that of the respiratory rate in darkness and to that of chrolophyll content in their parts, also the net photosynthetic rate of ears was related to water content in their parts. It is suggested that the ability of photosynthesis of ears may be less contributive to dry matter production, and have a net photosynthesis for a short time from heading to the milky stage. The gross photosynthetic rate of leaf sheaths had an intimate possitive correlation to the respiratory rate and the chrolophyll content in their organs through all growth stages. 3. The leaf sheaths and the ears of rice plats have an ability of net photosynthesis, however, the maximum rate is as small as 10 per cent and below 5 per cent of that of vigorous leaves. It is considered that the leaf sheaths and the ears of rice plants might be classified as non-photosynthetic organs on growth analysis studies, and light penetration within rice plant populations depresses the CO2 evolution from the leaf sheaths at daytime according to the relation of light intensity to photosynthesis of it.

65—THE CSIRO PORTABLE SONIC FINENESS TESTER, MODEL B

A small air-flow fineness tester for wool, which uses the sonic system and gives a direct reading of the fibre diameter, is now available commercially. It Is intended specifically for measurements of fibre diameter in such applications as ram selection and flock-culling. The instrument is accordingly calibrated for full-length hand-carded wool and uses a 2-g test specimen. An account is given of the instrument and trials conducted with it. An accuracy of ±0.5 μm is obtained if corrections for altitude and ambient conditions are made. An interesting feature is that it has been possible to produce commercial instruments with identical calibration characteristics. This has important implications for the future of the air-flow method.

1—THE VARIABILITY OF THE SPECIFIC GRAVITY OF AUSTRALIAN WOOLS AND THE IMPLICATIONS FOR THE AIR-FLOW MEASUREMENT OF DIAMETER

A study of a wide variety of Australian wools shows that their specific gravity varies about a mean of 1.3042, with a standard deviation between wools of 0.0028. This variability has a negligible effect on the accuracy of the air-flow method of measuring the diameter of wool samples.

The Effect of Moisture on Jute-fibre Fineness Determined by an Air-flow Method

Click to increase image sizeClick to decrease image sizeKEY WORDS (SPECIFIC TERMS): FIBRE FINENESSBULK DENSITYLINEAR DENSITYTEXPOROSITYAIR-FLOWREGAINABSORPTION (MATERIAL)DESORPTIONAIR-PERMEABILITY TESTINGGRAVIMETRIC TECHNIQUEJUTEFIBRESFIBRE PLUGKEY WORDS (BROADER TERMS): FIBRE PROPERTIESDENSITYCOUNTSTRUCTURAL PROPERTIESSORPTIONTESTINGBAST FIBRES

31—COMPARISONS OF MICROPROJECTION AND AIR-FLOW DIAMETER MEASUREMENTS FOR SCOURED WOOL

A comparison is reported of fineness results obtained for 27 lots of scoured wool by the projection-microscope and air-flow methods. The sampling of the scoured wool was done by core-boring, and the cores were hand-carded before air-flow tests were made. The sub-samples for projection-microscope measurement were cut into snippets 1 mm long in order to obtain a length-biassed sample. The air-flow apparatus was calibrated with reference tops in five different forms. The results show that there exists a systematic difference between the air-flow and projection-microscope mean diameters of scoured wool when the air-flow instrument is calibrated with reference tops in the original state. A better agreement results by hand-carding the test samples of the reference tops, but the closest agreement is obtained by cutting, washing, and hand-carding these test samples so that their condition is similar to that of the core sample being tested. Provided that this kind of calibration were applied, the mean diameter of ...