365 research outputs found

    Heat flux sensor research and development: The cool film calorimeter

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    The goal was to meet the measurement requirement of the NASP program for a gauge capable of measuring heat flux into a 'typical' structure in a 'typical' hypersonic flight environment. A device is conceptually described that has fast response times and is small enough to fit in leading edge or cowl lip structures. The device relies heavily on thin film technology. The main conclusion is the description of the limitations of thin film technology both in the art of fabrication and in the assumption that thin films have the same material properties as the original bulk material. Three gauges were designed and fabricated. Thin film deposition processes were evaluated. The effect of different thin film materials on the performance and fabrication of the gauge was studied. The gauges were tested in an arcjet facility. Survivability and accuracy were determined under various hostile environment conditions

    Polaradiometric pyrometer in which the parallel and perpendicular components of radiation reflected from an unpolarized light source are equalized with the thermal radiation emitted from a measured object to determine its true temperature

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    A radiation pyrometer for measuring the true temperature of a body is provided by detecting and measuring thermal radiation from the body based on the principle that the effects of angular emission I(sub 1) and reflection I(sub 2) on the polarization states p and s of radiation are complementary such that upon detecting the combined partial polarization state components I(sub p) =I(sub 1p) + I(sub 2p) and I(sub s)=I(sub 1s) + I(sub 2s) and adjusting the intensity of the variable radiation source of the reflected radiation I(sub 2) until the combined partial radiation components I(sub p) and I(sub s) are equal, the effects of emissivity as well as diffusivity of the surface of the body are eliminated, thus obviating the need for any post processing of brightness temperature data

    Method and Apparatus for Polaradiometric Pyrometer

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    A radiation pyrometer for measuring the true temperature of a body is provided by detecting and measuring thermal radiation from the body based on the principle that the effects of angular emission I(sub 1) and reflection I(sub 2) on the polarization states p and s of radiation are complementary such that upon detecting the combined partial polarization state components I(sub p) = I(sub 1p) + I(sub 2p) and I(sub s) = I(sub 1s) + I(sub 2s) and adjusting the intensity of the variable radiation source of the reflected radiation I(sub 2) until the combined partial radiation components I(sub p) and I(sub s) are equal, the effects of emissivity as well as diffusivity of the surface of the body are eliminated, thus obviating the need for any post processing of brightness temperature data

    A Duhamel Integral Based Approach to Identify an Unknown Radiation Term in a Heat Equation with Non-linear Boundary Condition

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    In this paper, we consider the determination of an unknown radiation term in the nonlinear boundary condition of a linear heat equation from an overspecified condition. First we study the existence and uniqueness of the solution via an auxiliary problem. Then a numerical method consisting of zeroth-, first-, and second-order Tikhonov regularization method to the matrix form of Duhamel\u27s principle for solving the inverse heat conduction problem (IHCP) using temperature data containing significant noise is presented. The stability and accuracy of the scheme presented is evaluated by comparison with the Singular Value Decomposition (SVD) method. Some numerical experiments confirm the utility of this algorithm as the results are in good agreement with the exact data

    Estimating growth parameters for Otolithes ruber in waters of Bushehr, Hormozgan and Sistan and Baluchestan Province, Southern Iran

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    Using length frequency of the Otolithes ruber collected in waters of three southern province of Iran, we estimated the fish growth parameters and monthly measured fork length of around 1000 fish caught using gill net with a mesh size of 6.5 centimeters in waters of this study area. The length infinity (L∞) in Bushehr, Hormozgan and Sistan and Baluchistan province was estimated as 58.5, 56, 59.5 centimeters, growth coefficient per year (K) as 0.48, 043, 0.32 and age at zero length (to) as -0.006, -0.002, -0.001 respectively. The relationship between length and weight of the fish in the three provinces determined. The parameters q, b and r (correlation coefficient) were 0.173, 2.868, 0.984 for Bushehr, 0.012, 2.962, 0.932 for Hormozgan and 0.056, 2.604, 0.921 for Sistan and Baluchestan province. We also evaluated the average length for the fish caught in different months and landing places. An ANOVA test showed a significant difference (P≤0.05) between the average lengths of the fish caught in different months

    Individual differences in embodied distance estimation in virtual reality

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    There are important individual differences when experiencing VR setups. We ran a study with 20 participants who got a scale-matched avatar and were asked to blind-walk to a VR target placed 2.5 meters away. In such setups, people typically underestimate distances by approximately 10% when virtual environments are viewed through head mounted displays. Consistent with previous studies we found that the underestimation was significantly reduced the more embodied the participants were. However, not all participants developed the same level of embodiment when exposed to the exact same conditions

    Assessing Pb, Ni and Zn accumulation in the tissues of Liza aurata in the south Caspian Sea

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    The liver, kidney, gill, ovary and muscle tissues of the caught Liza aurata have been sampled in spring 2002 in the southern Caspian Sea to assess their contamination with Pb, Ni and Zn using atomic absorption spectrophotometer method. We found the highest concentration of lead in the liver tissue (17.51 mg/kg), followed by gill (13.95 mg/kg); kidney (5.03 mg/kg) and ovary (4.91 mg/kg). The lowest concentration of lead was seen in muscle tissue (3.01 mg/kg) of Liza aurata. The highest accumulation of Ni and Zn were detected in ovary followed by liver, gill and kidney of the fish with a concentration of 6.23, 6.14, 5.71, and 2.98 mg/kg for Nickel and 647.28, 159.85, 75.71 and 65.42 mg/kg for Zinc. We observed the lowest concentration of Nickel (2.49 mg/kg) and Zinc (20.14 mg/kg) in the muscle tissue and also determined the highest contamination of the fish with these chemicals to be occurring in the southwest followed by south center and southeast Caspian Sea

    Effects of hydrogen peroxide on fungal disinfection, hatch rate and larval deformities of rainbow trout (Oncorhynchus mykiss)

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    The hydrogen peroxide in concentrations of 500, 750 and 1000 mu l/l, malachite green with usual concentration (1.5mg/l) and natural control treatments were examined to evaluate the antifungal effects of the chemicals on Rainbow Trout eggs. Hydrogen peroxide and malachite green treatments were performed after 48 hours after fertilization in every other day, until 4 days before hatch, each time for 15 minutes. During experiments, water parameters were measured which were 8.05±0.55mg/l for dissolved oxygen, 8.8±2.2 ° C for temperature, 7.9±0.05 for pH, 132±20mg/l for total hardness, and E.C was 336±24 mu s/cm. The fungal infection was minimal in malachite green treatment and was significantly different with other treatments (P>0.05). No significant difference in deformities caused by the treatments were observed (P>0.05)
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