Estimates Of Ts Research Articles

Evaluation of “all weather” microwave-derived land surface temperatures with in situ CEOP measurements

[1] Land surface skin temperature Ts plays a key role in meteorological and climatological processes but the availability and the accuracy of Ts measurements over land are still limited, especially under cloudy conditions. Ts estimates from infrared satellite observations can only be derived under clear sky. Passive microwave measurements are much less affected by clouds and can provide Ts regardless of the cloud conditions. A neural network inversion including first guess information has been previously developed to retrieve Ts, along with atmospheric water vapor, cloud liquid water, and surface emissivities over land from Special Sensor Microwave/Imager measurements, with a spatial resolution of 0.25° × 0.25°, at least twice daily. In this study, Ts estimates are evaluated through careful comparisons with in situ measurements in different environments over a full annual cycle. Under clear sky conditions, the quality of our microwave neural network retrieval is equivalent to the infrared International Satellite Cloud Climatology Project products, for most in situ stations, with errors ∼3 K as compared to in situ measurements. The performance of the microwave algorithm is similar under clear and cloudy conditions, confirming the potential of the microwaves under clouds. The Ts accuracy does not depend upon the surface emissivity, as the variability of this parameter is accounted for in the processing. Our microwave Ts have been calculated for more than 15 years (1993 to mid-2008). These “all weather” Ts are a very valuable complement to the IR-derived Ts, for use in atmospheric and surface models.

Radial Qμ structure of the lower mantle from teleseismic body-wave spectra

We have measured 150,000 P and 130,000S wave spectral ratios up to 0.8Hz using recordings of 250 deep (focal depth >200km) earthquakes from 890 global and regional network stations. We have inverted these data to estimate the attenuation parameters tP⁎ and tS⁎ for P and S waves and a radial profile of the quality factor Qμ for the lower mantle. On average, tP⁎ increases by about 0.2s and tS⁎ increases by about 0.7s between epicentral distances of 30° and 97°. The relatively strong increase of tS⁎ (ts≈4tP⁎) suggests that intrinsic shear attenuation is the cause of the overall trend in our data. The increase of tP⁎ and tS⁎ with distance is smaller than predicted by models PREM [12], QL6 [11], and QLM9 [16]. Assuming PREM values for Qμ in the upper mantle, where the data lack resolving power, the P and S wave spectra are explained best if Qμ increases from about 360 at PREM's 670-km discontinuity to 670 in the lowermost mantle. The high values for Qμ can be reconciled with previously determined values by invoking a frequency-dependence of Qμ(ω) that is proportional to ω0.1. Data that are separated in ‘Pacific’ and ‘circum-Pacific’ subsets have slightly different trends. Estimates of tP⁎ and tS⁎ for the Pacific data, which sample the large low shear-velocity province of the Pacific, are higher than the circum-Pacific estimates. Thus, it appears that the Pacific large low shear velocity province has accompanying low Qμ. The difference in Qμ in the lowermost 1000km of the mantle beneath the Pacific and beneath the circum-Pacific is at most 17%. Lateral variations of this magnitude are marginally resolvable given the uncertainties of our measurements.

The acoustic identification and enumeration of scyphozoan jellyfish, prey for leatherback sea turtles (Dermochelys coriacea), off central California

Abstract Graham, T. R., Harvey, J. T., Benson, S. R., Renfree, J. S., and Demer, D. A. 2010. The acoustic identification and enumeration of scyphozoan jellyfish, prey for leatherback sea turtles (Dermochelys coriacea), off central California. – ICES Journal of Marine Science, 67: 1739–1748. Acoustic-sampling techniques were developed to estimate the abundance and distribution of scyphozoan jellyfish, prey for leatherback turtles foraging off central California. Acoustic data were analysed from regions where jellyfish were present or absent from corresponding net tows. Empirical data on bell-diameter distribution (mean 26.2 cm; s.d. 10.6) were used to estimate target strength (TS; dB re 1 m2) at 18, 38, 70, 120, and 200 kHz using a distorted-wave Born approximation scattering model. TS measurements of in situ animals at 38 and 200 kHz averaged −63.9 and −70.5 dB, compared with the model estimates of −54.9 and −64.0 dB, respectively. The model estimates of TS at 18, 70, and 120 kHz were −53.9, −59.9, and −61.8 dB, respectively. Using these TS estimates, an algorithm was developed to extract jellyfish echoes from total acoustic backscatter. Echo-integration methods applied to regions where net catches contained jellyfish resulted in an estimate of mean numerical abundance of 3217 jellyfish (s.d. 2276) with a mean density of 251 522 jellyfish nautical mile−2 (s.d. 57 504) and a mean concentration of 0.003 jellyfish m−3 (s.d. 0.002). The novel methods developed will help characterize prey resources for leatherback turtles off central California.

Derivation of land surface temperature using measurements of IR radiances from geostationary meteorological satellites

Considered is a new method of remote derivation of the land surface temperature (LST) Ts using data of nonsimultaneous measurements of the SEVIRI/Meteosat-9 instrument in channels of transparency windows of 10.5–12.5 μm in the case of the cloudiness absence in the field of instrument. The method is the combination of two well-known algorithms of the subject processing of satellite data. It enables to derive Ts without the involvement of data on the values of the land emissivity at sounding stations. Experiments on the processing of SEVIRI actual data of some autumn days of 2008, as well as a comparison of the results with independent satellite estimations of Ts, confirm the operability and efficiency of the proposed method. The possibility of detailed description of the diurnal course of LST on the basis of SEVIRI data using the proposed method of Ts estimation is analyzed.

Evaluation of modeling procedure for fitting in situ feed degradation profiles1

In situ degradation of feeds is a common methodology used for describing the digestion rate and potential for many chemical components of ruminant feedstuffs. The inferences involving the parameters of these procedures may be of questionable accuracy and precision because nonlinear regression techniques that are employed to fit these models do not produce unbiased, normally distributed, and minimum variance parameter estimates until the sample size becomes very large. Therefore, the objective of this experiment was to determine the accuracy and precision of parameter estimates determined by a 2-stage approach (TS; in which individual kinetic parameter estimates are obtained in the first stage and population estimates are obtained by arithmetic mean in the second), a 2-stage, geometric mean approach (GEO), and by nonlinear mixed modeling (NLMM) using simulation techniques. An experiment using corn silage NDF was used as a reference for simulating parameter and error structures. For all analyses, 500 experiments were simulated with sampling time points of 1, 2, 4, 8, 16, 24, 48, and 72 h. Increasing levels of animal and bag replication were evaluated at 2 levels of residual variability [residual SD of 2.95 (observed from the data; R(2) = 0.985) and 5.90 (2x observed; R(2) = 0.950)]. Evaluation of the first-order exponential model with discrete lag revealed that median bias of TS and GEO parameter estimates were more sensitive to increased residual variation and degree of replication than NLMM. When residual variation was less, precision of parameter estimates was less affected by estimation procedure; when residual variation was greater, precision of parameter estimates was generally improved by NLMM. From the results of this experiment it is concluded that, in most cases, NLMM is equal or better than TS or GEO from the perspective of minimizing bias and maximizing precision of parameter estimates.

Two-stage estimation of inequality-constrained marginal linear models with longitudinal data

Inequality-constrained regression models have received increased attention in longitudinal analysis during recent years. Regression parameters are usually obtained from iteration algorithms. An analytical formulae of the estimators cannot be provided. Therefore, the asymptotic behavior of estimators has not been fully clarified yet. This paper presents a TS estimation (TS for short) and the asymptotic distribution of the estimators. Simulations are conducted to compare constrained TS estimation, constrained ordinary least squares (OLS) estimation and TS estimation in terms of sample bias, sample mean-square error (MSE) and sample variance of the estimators.

Spatial mapping of growing degree days: an application of MODIS-based surface temperatures and enhanced vegetation index

Growing degree days (GDD) is a simple temperature-based index of biological development. In this paper we evaluated the potential of using 2003-2005 MODIS-based 8-day and 16-day composites of daytime surface temperature (TS) and enhanced vegetation index (EVI) values at 250 m resolution for mapping GDD. The work was applied to the Canadian Atlantic Maritime Ecozone as a demonstration of the methodology. The work proceeded by establishing an empirical relationship between mean tower-based estimates of TS for the MODIS-acquisition period of 10:30 am-12:00 pm and the daily mean TS calculated from half-hourly emitted infrared/longwave radiation measurements taken from four flux sites in southern commercial forests of Canada. The relationship revealed a strong correlation between variables (r2=98.4%) and was central to the calculation of daily mean TS from MODIS-based estimates of TS. Since seasonally-based estimates of GDD and EVI were strongly correlated (r2=87%), data fusion techniques were applied to enhance the GDD map originally produced at 1 km resolution (from infrared emission band data), to 250 m. In general, the MODIS-derived map of GDD showed a positive constant offset of about 511 degree days from calculated long-term averages (1971 2000) based on temperatures collected at 101 Environment Canada climate stations.

Hourly and Daytime Evapotranspiration from Grassland Using Radiometric Surface Temperatures

Determination of evapotranspiration (E) is needed for many applications in agriculture, hydrology, and meteorology. The spatial variability of leaf area index (LAI) and soil water availability makes it impractical to modelEover heterogeneous lands using ground‐based techniques. Remote sensing can be a good source for both LAI and radiometric surface temperature (Ts) estimates. However, remotely sensed soil moisture content is not suitable forEprediction. In this study, we propose a procedure to estimateEusingTs. The method uses a dimensionless temperature ΔT, defined as (Ts–Ta)/(Tmax–Ta), whereTais the air temperature andTmaxis the surface temperature that would occur if all the net radiation (Rn) was converted to sensible heat flux and no evaporation occurred. This approach has been tested on data from two grassland sites in Oklahoma and Kansas. Root mean square differences between hourly predicted and measuredEranged from 30 to 50 W m−2. The slope andr2for the zero‐intercept linear regression between hourly estimated and measuredEranged from 1.01 to 1.37 and 78 to 0.94, respectively. Daytime conservation of evaporative fraction (EF =E/Rn) was used to extrapolate from hourly to daytimeE. The slope andr2of the linear regression between daytime estimated and measuredEranged from 0.89 to 1.07 and 0.69 to 0.9, respectively. These results demonstrate that, for grassland, the model may give good estimates ofEwhenTaandTsare available.

Hourly and Daytime Evapotranspiration from Grassland Using Radiometric Surface Temperatures

Determination of evapotranspiration (E) is needed for many applications in agriculture, hydrology, and meteorology. The spatial variability of leaf area index (LAI) and soil water availability makes it impractical to model E over heterogeneous lands using ground-based techniques. Remote sensing can be a good source for both LAI and radiometric surface temperature (Ts) estimates. However, remotely sensed soil moisture content is not suitable for E prediction. In this study, we propose a procedure to estimate E using Ts. The method uses a dimensionless temperature ΔT, defined as (Ts – Ta)/(Tmax – Ta), where Ta is the air temperature and Tmax is the surface temperature that would occur if all the net radiation (Rn) was converted to sensible heat flux and no evaporation occurred. This approach has been tested on data from two grassland sites in Oklahoma and Kansas. Root mean square differences between hourly predicted and measured E ranged from 30 to 50 W m−2. The slope and r2 for the zero-intercept linear regression between hourly estimated and measured E ranged from 1.01 to 1.37 and 78 to 0.94, respectively. Daytime conservation of evaporative fraction (EF = E/Rn) was used to extrapolate from hourly to daytime E. The slope and r2 of the linear regression between daytime estimated and measured E ranged from 0.89 to 1.07 and 0.69 to 0.9, respectively. These results demonstrate that, for grassland, the model may give good estimates of E when Ta and Ts are available.

Multi‐variable relations for soil effects on seismic ground motion

AbstractSoil effects on peak ground acceleration, velocity and elastic response spectra (5% damping) are expressed by simple approximate relations in terms of five key parameters: (a) the fundamental vibration period of the non‐linear soil, TS, (b) the period of a bedrock site of equal thickness, Tb, (c) the predominant excitation period, Te, (d) the peak seismic acceleration at outcropping bedrock, a, and (e) the number of significant excitation cycles, n. Furthermore, another relation is proposed for the estimation of TS in terms of the soil thickness H, the average shear wave velocity of the soil V̄S,o and a. The aforementioned parameters were first identified through a simplified analytical simulation of the site excitation. The multivariable approximate relations were then formulated via a statistical analysis of relevant data from more than 700 one‐dimensional equivalent‐linear seismic ground response analyses, for actual seismic excitations and natural soil conditions. Use of these relations to back‐calculate the numerical results in the database gives an estimate of their error margin, which is found to be relatively small and unbiased. The proposed relations are also independently verified through a detailed comparison with strong motion recordings from seven well‐documented case studies: (a) two sites in the San Fernando valley during the Northridge earthquake, and (b) five different seismic events recorded at the SMART‐1 accelerometer array in Taiwan. It is deduced that the accuracy of the relations is comparable to that of the equivalent‐linear method. Hence, they can be readily used as a quick alternative for routine applications, as well as for spreadsheet computations (e.g. GIS‐aided seismic microzonation studies) where numerical methods are cumbersome to implement. Copyright © 2003 John Wiley & Sons, Ltd.

Toward an Integrated Land–Ocean Surface Skin Temperature Analysis from the Variational Assimilation of Infrared Radiances

Abstract Geostationary Operational Environmental Satellite (GOES)-East and -West window channel radiances are directly assimilated using a 1D variational technique, providing surface skin temperature (Ts) estimates over all surface types (land, water, or ice) from a unique system. This is an important advantage over commonly used regression methods, such as split window. The physical nature of the method allows any combination of channels to be used, and adaptation to new sensors is straightforward. A full month (May 2001) of GOES-8 and -10 data is processed every 6 h; Ts estimates are obtained using radiances from imager channels 4 (11 μm) and 5 (12 μm). Imager channel 2 (3.9 μm) can also be used at night. Surface emissivity maps were constructed from available information based on surface type. The diurnal cycle is studied; its range is on the order of 0.7 K over the ocean. Over land, the diurnal range reaches 30 K for mountainous regions, such as the Rockies or Andes. A full GOES disk image can be proc...

A deep search for 21-cm absorption in high redshift damped Lyman-αsystems

We present deep GMRT 21-cm absorption spectra of 10 damped Lyman- systems (DLAs), of which 8 are at redshifts z> 1:3. HI absorption was detected in only one DLA, the z= 0:5318 absorber toward PKS 1629+12. This absorber has been identified with a luminous spiral galaxy; the spin temperature limit (Ts 310 K) derived from our observations continues the trend of DLAs associated with bright spirals having low spin temperatures. In seven of the remaining 9 systems, the observations place strong lower limits on the spin temperature of the HI gas. We combine this sample with data taken from the literature to study the properties of all known DLAs with 21-cm absorption studies. The sample of DLAs which have been searched for 21-cm absorption now consists of 31 systems, with Ts estimates available in 24 cases; of these, 16 are at z 2, with 11 (all at z 1000 K) have been identified either with LSBs or dwarfs. Further, we find no correlation between impact parameter and spin temperature; it is thus unlikely that the high measured Ts values for DLAs arise from lines of sight passing through the outskirts of large disk galaxies. Instead, the spin temperature of DLAs appears to correlate with the host galaxy type. The trend (noted earlier by Chengalur & Kanekar 2000) that low z DLAs exhibit both high and low Ts values while high redshift (z> 3) DLAs only show high spin temperatures is present in this expanded data set. Based on this dierence in spin temperatures, the Gehan test rules out the hypothesis that DLAs at z> 2 and DLAs at z 3. For local spirals, fCNM 0:5; in contrast, we find that fCNM< 0: 3i n all 7h ighz absorbers, and fCNM< 0: 1i n 5o f the 7c ases.

Simultaneous estimation of TG2M, TS, and Tpot using single sample dynamic tumor data from bivariate DNA‐thymidine analogue cytometry

Background Estimating the duration of S phase (TS ) and the potential doubling time (Tpot ) from a single time measurement of the movement of cells using bivariate cytometry is common. However, these estimates require an assumption of the duration of G2 + M (TG2+M ). Inspection of the measured dynamic quantities, relative movement [RM(t)], fractions of labeled divided and undivided cells (flu(t) and fld(t)) suggests that TG2+M, TS, and Tpot can be determined simultaneously. Methods An equation connecting the growth of the cell population, time, and the dynamic quantities was determined. The equation cannot be solved analytically, but accurate approximations can be used to find Tpot. From this result, the value of TG2+M can be determined from fld(t), and TS can be determined from RM(t). Results Kinetic parameters obtained from single time estimates using the new method compared to those obtained from the analysis of multiple time-point measurements of MCa-K and MCa-4 murine tumors are shown to be in close agreement. Moreover, estimates of TG2+M in MCa-4 tumors, treated with paclitaxel, provide extra information on the changes in TG2+M. When applied to the rat R3327-G prostate tumor model following androgen ablation, a correlation analysis of the Tpot values obtained by the new and previous single time-point methods demonstrates that the rank order from shortest to longest Tpot values are largely preserved. Conclusions The new procedure makes direct estimation of TG2+M possible from single time-dynamic measurements. The results from previous studies on TS and Tpot are largely unchanged, but extra information is now available. Cytometry 41:1–8, 2000 © 2000 Wiley-Liss, Inc.

Quantitative estimation of Thiosphaera pantotropha from aerobic mixed culture

This paper reports the successful modification of a plate count media to selectively enumerate Thiosphaera pantotropha from mixed culture and suppress the growth of Pseudomonas. Fourteen samples were prepared in the laboratory and analysed for standard plate count (SPC) on a selective medium which was slightly modified by increasing the concentration of MgSO 4 from 0.1 to 0.3 g/l to prevent growth of other organisms. The samples were actually contaminated by Pseudomonas, but the results show that the formation of Pseudomonas colonies was prevented, while no inhibition of growth of Thiosphaera pantotropha occurred. This shows that the modified medium can be used for quantitative estimation of Ts. pantotropha. This is important as the aerobic denitrification potential of the organism could prove useful in wastewater treatment.

Performance of a new phase algorithm for discriminating between single and overlapping echoes in a split-beam echosounder

The performance of a new single target detection algorithm (version 5.0) in the Simrad EK500 split-beam echosounder which uses the standard deviation in the sampled phase of received echoes as a detection criteria, was tested under controlled conditions using spheres as targets. Although not infallible, the new algorithm enables the user to achieve improved rejection performance without inducing a bias against weaker single targets, when operating at pulse durations of 1.0 ms at 38 kHz. At a pulse duration of 0.3 ms, however, the phase discrimination was unreliable due to the reduced number of samples falling within the 6 dB limits of the echo peak. The implications of this behaviour on in situ estimation of TS are discussed. ? 1997 International Council for the Exploration of the Sea

Cell kinetic measurements in prostate cancer

Two approaches have been suggested for escalating the total dose in radiotherapy treatment of prostate cancer. One is conformal radiotherapy; the other is hyperfractionation using many small fractions. Both imply some possible prolongation in overall treatment time. To judge whether prolonged treatment schedules would be detrimental, it is necessary to know the proliferation rates in human prostate tumors, specifically, the potential doubling time (Tpot). There is a lack of data on this parameter in the literature. Seven patients with adenocarcinoma of the prostate were studied. A tracer dose of 100 mg/m2 of IUdR was infused intravenously 4-12 h before biopies were taken. Biopsies were fixed in 70% ethanol, stored at 4 degrees C, and later prepared and stained by standard methods for flow cytometry, using the red fluorescence signal for DNA and the green fluorescence signal (fluorescein isothiocyanate) for 5-iodo-2'-deoxyuridine. The duration of DNA synthesis (Ts) was determined by the relative movement (RM) method, knowing the interval between tracer administration and biopsy. Tpot was calculated as the quotient of Ts by labeling index (LI). In two of the seven tumors the LI was too low (<0.6%) for a reliable estimate of RM to be made, so no determination of Tpot was possible for these tumors. The mean LI values in the other five tumors were 2.4%, 1.4%, 1.0%, 3.0%, and 0.9%. The durations of Ts were 13.2, 9.5, 10.0, 11.7, and 12.7 h, respectively. The resulting values of Tpot were 23, 28, 42, 16, and 61 days, respectively. The low labeling indices in prostate tumors, also reported by others, made estimation of Ts by RM impossible in about a third of these tumors. However, five tumors yielded long estimates for Tpot, implying that prolongation from 6 to about 8 weeks should not be detrimental.

Comparison of mathematical formulas used for estimation of DNA synthesis time of bromodeoxyuridine-labelled cell populations with different proliferative characteristics.

Growth kinetic data of human tumours, obtained by flow cytometric analysis of cells labelled with bromodeoxyuridine (BrdUrd) might provide prognostic information and allow prediction of response to radio- and chemotherapy. However, the theoretical models applied for calculation of growth kinetic data are not fully evaluated. The purpose of this study was to investigate the dependence of the estimation of DNA synthesis time (Ts) on sampling time after BrdUrd labelling, using four different mathematical formulas (Begg et al., White & Meistrich, White et al. and Johansson et al.) which have been developed for the evaluation of flow cytometry-derived data of BrdUrd-labelled cells. In addition, we have investigated the influence of the growth kinetic properties of the cell populations using two cultured cell lines (one slow and one fast growing), and two hetero-transplanted human tumours. The dependence of the estimation of Ts on sampling time was more or less pronounced, depending on the cell population examined and on the formula used. In the fast growing cell line, the estimates of Ts did not vary significantly with sampling time when using the formulas by White et al., whereas in the slow growing cell line, the estimates of Ts did not show any significant dependence on sampling time when using the formula by Johansson et al. In the tumours, the estimation of Ts depended on sampling time with all formulas used, although to different degrees. In one of the tumours, this was mainly caused by the influence of mouse cells, as we demonstrate. Our results indicate that the proliferative characteristics of a cell population should be taken into consideration when choosing a mathematical formula in order to attain Ts values that are independent of sampling time.

Accuracy of sea ice temperature derived from the advanced very high resolution radiometer

The accuracy of Arctic sea ice surface temperatures Ts derived from advanced very high resolution radiometer (AVHRR) thermal channels is evaluated in the cold seasons by comparing them with surface air temperatures Tair from drifting buoys and ice stations. We use three different estimates of satellite surface temperatures, a direct estimate from AVHRR channel 4 with only correction for the snow surface emissivity but not for the atmosphere, a single‐channel regression of Ts with Tair, and Key and Haefliger's (1992) polar multichannel algorithm. We find no measurable bias in any of these estimates and few differences in their statistics. The similar performance of all three methods indicates that an atmospheric water vapor correction is not important for the dry winter atmosphere in the central Arctic, given the other sources of error that remain in both the satellite and the comparison data. The errors are not reduced by regression with both thermal channels and the satellite scan angle. A record of drifting station data shows winter air temperature to be 1.4°C wanner than the snow surface temperature. “Correcting” air temperatures to skin temperature by subtracting this amount implies that satellite Ts estimates are biased warm with respect to skin temperature by about this amount. A case study with low‐flying aircraft data suggests that ice crystal precipitation can cause satellite estimates of Ts to be several degrees warmer than radiometric measurements taken close to the surface, presumably below the ice crystal precipitation layer. An analysis in which errors are assumed to exist in all measurements, not just the satellite measurements, gives a standard deviation in the satellite estimates of 0.9°C, about half the standard deviation of 1.7°C estimated by assigning all the variation between Ts and Tair to errors in Ts.

Mating system parameters and population genetic structure in pioneer populations of Prosopis velutina (Leguminosae)

This study describes the genetic structure and provides estimates of mating system parameters in three natural populations of Prosopis velutina Woot. in southeastern Arizona. F statistics derived from isozyme data revealed the presence of both interpopulation and intrapopulation genetic differentiation. This population structure is discussed in relation to the ecological history of these populations that invaded the grasslands sites from adjacent riparian areas within the last 90 years, and possible modes of seed dispersal. The multilocus estimation program MLT of Ritland (Journal of Heredity 8: 235–237, 1990) was used to provide estimates of ts, tm, and the fixation index (F) of the maternal parents. Average estimates of ts ranged from 0.591 to 0.912. Estimates of tm ranged from 0.609 to 1.004, and averaged 0.758. The difference between tm and ts, which provides a measure of biparental inbreeding, averaged 0.058. This last result, together with significant heterogeneity found in pollen allele frequencies, suggests that a family structure has developed in the populations. A negative F value for one of the populations suggests selection against homozygotes between the seedling stage and maturity.

Simplified calculation of temperature field in heat treated cylinder using temperature measured at one point

AbstractThe calculation of the temperature field T(r) in a heat treated cylinder requires a knowledge of the heat transfer coefficient h(Ts) which may show a highly non-linear dependence on the surface temperature Ts. Since h(Ts) can very often not be explicitly determined, measurement of a temperature Ti near the surface is employed. As a result the analysis becomes an inverse (‘ill posed’) problem which cannot be handled using standard finite element codes that are applicable only to direct problems. By implementing a procedure for an explicit estimation of the surface temperature Ts the problem can be overcome via two direct calculations. Diagrams are presented for calculation of both the surface temperature Ts and the heat transfer coefficient h(Ts). The method is applied to the investigation of a duplex steel cylinder which is quenched in cold water. The accuracy of the method is discussed and the complex nature of h(Ts) is demonstrated.MST/1497