A practical method for determining film thickness using X-ray absorption spectroscopy in total electron yield mode

Thin films formed on surfaces have a large impact on the properties of materials and devices. In this study, a method is proposed using X-ray absorption spectroscopy to derive the film thickness of a thin film formed on a substrate using the spectral separation and logarithmic equation, which is a modified version of the formula used in electron spectroscopy. In the equation, the decay length in X-ray absorption spectroscopy is longer than in electron spectroscopy due to a cascade of inelastic scattering of electrons generated in a solid. The modification factor, representing a multiple of the decay length, was experimentally determined using oxidized Si and Cu with films of thickness 19 nm and 39 nm, respectively. The validity of the proposed method was verified, and the results indicated that the method can be used in the analysis of various materials with thin films.

Reproducibility of Skin Temperature Response after Cold Stress Test Using the Game Ready System: Preliminary Study

The objective of this preliminary study was to determine the reproducibility of lower limbs skin temperature after cold stress test using the Game Ready system. Skin temperature of fourteen participants was measured before and after cold stress test using the Game Ready system and it was repeated the protocol in four times: at 9:00, at 11:00, at 19:00, and at 9:00 h of the posterior day. To assess skin temperature recovery after cold stress test, a logarithmic equation for each region was calculated, and constant (β0) and slope (β1) coefficients were obtained. Intraclass correlation coefficient (ICC), standard error (SE), and within-subject coefficient of variation (CV) were determined. No differences were observed between measurement times in any of the regions for the logarithmic coefficients (p > 0.38). Anterior thigh (β0 ICC 0.33–0.47; β1 ICC 0.31–0.43) and posterior knee (β0 ICC 0.42–0.58; β1 ICC 0.28–0.57) were the regions with the lower ICCs, and the other regions presented values with a fair and good reproducibility (ICC > 0.41). Posterior leg was the region with the better reproducibility (β0 ICC 0.68–0.78; β1 ICC 0.59–0.74; SE 3–4%; within-subject CV 7–12%). In conclusion, cold stress test using Game Ready system showed a fair and good reproducibility, especially when the posterior leg was the region assessed.

Hydraulic Characteristics of Concentrated Flow Relative to Angle between Rock Strata and Slope in the Karst Trough Valley Area

<p><strong>A</strong><strong>b</strong><strong>stra</strong><strong>c</strong><strong>t</strong><strong>: </strong>Outcrops of rock strata in the Karst Trough Valley Area often form angles with slopes, thus making micro landforms complicated and altering significantly paths of concentrated flows, and consequently bringing about great changes in characteristics of the flows. So, it’s important to study hydraulic characteristics of the concentrated flows relative to angle between rock strata and slope. To that end, a flume experiment, designed to have combinations of three slope gradients (10°,15° and 20°), three flow rates (5, 7.5 and 10 L·min-1) and six angles between the rock strata and slope (30°, 60°, 90°, 120°, 150° and 180° (0°)), was carried out. Results show that hydraulic characteristics of a concentrated flow varied significantly with the angle between the rock stratum and slope. Reynolds number (Re) of the concentrated flow changed with duration of the scouring in a complicated trend, but exhibited a significant trend of increasing with rising flow rate, and an insignificant one of changing with slope gradient. And it varied in the range of 517~3343 in the experiment. Darcy-Weisbach friction coefficient (f) of the concentrated flow increased with rising slope gradient and with scouring going on, but decreased with rising flow rate. And it varied in the range of 0.62~5.70 in the experiment. The relationship of Re with angles between rock strata and the slope was not significant, but that of f varied with combinations of slope gradient and flow rate. The coupling relationship between f and Re was influenced significantly by the angle between the rock stratum and the slope. It could be better described with a logarithmic equation when the angle between the rock stratum and the slope was narrower than 90°, and with a power function equation when the angle between the rock stratum and the slope was wider than or equal to 90°. In the experiment, when Re<1791, the relationship between f and Re was not apparent, but when Re>1791, it was significantly positive. To sum up, f and Re and their relationship vary with the angle between the rock stratum and the slope. The findings in this experiment may provide strong data support for establishing soil erosion prediction models in the Karst Trough Valley Area.</p>

Influence of thermal radiation on singular behavior of the Universe

Cosmological models with inhomogeneous viscous fluids with a logarithmic equation of state in the Friedmann-Lemaitre-Robertson-Walker universe are considered. The influence of thermal effects caused by Hawking radiation on the visible horizon of the Universe on the change in the type of singularity of the dark Universe is investigated. It is shown that under the influence of thermal radiation, taking into account the viscosity property of a dark fluid, a qualitative change in the type of the Big Rip singularity is possible, which can lead to the absence of a singularity in the Universe at all.

PENDUGAAN KANDUNGAN KARBON TEGAKAN AKASIA (Acacia mangium WILD) BERBASIS BEF DI PT INHUTANI III SEBUHUR KALIMANTAN SELATAN

The purpose of this research is to estimate the potential of carbon in the standing of Acacia mangium Willd in Areal PT INHUTANI III Sebuhur of South Kalimantan. The research method of using the ALOS satellite imagery is georectification so that the image position corresponds to the actual position in the field and to see the uniformity of the sample in the NDVI, a descriptive statistical test in the respective NDVI and Klas diameter. Based on the NDVI classification on Citra Alos in 2012, the land area of the wooded area of PT INHUTANI III Sebuhur is 8,183.18 ha. Results Biomass Expansion Factor (BEF) based on 4 klas diameter with polynomial equation Y =-0.0057 X2 + 0.014 x + 1.2623; R ² = 0.9621 is a klas 5 – 10 diameter in the total of 1,272, Klas, 10 – 15 diameter in total 1.263, klas, in diameter 15 – 20 in total 1.258 and Klas > diameter 20 totalnya1,226. The result of total carbon potential in wooded areas of PT INHUTANI III Sebuhur is 31,497.11 ton/Ha, so the average carbon potential of 3.8489 Ton/Ha. Meanwhile, the potential carbon (ton/ha) based on NDVI 2-7 according to the logarithmic equation Y = 4.7925 ln (X)-2.0321; R ² = 0.9167, with Y is the potential carbon ton/ha and X is NDVI Klas is Klas NDVI 2 1.0462 tons/ha, Klas NDVI 3 of 3.7918 tons/ha, Klas NDVI 4 of 4.7479 tons/ha, Klas NDVI 5 of 4.7213 tons/ha, Klas NDVI 6 of 7.0632 tons/ha, and Klas NDVI 7 of 5.2875 ton/ha.

Mapping of Seawater Intrusion into Coastal Aquifer: A Case Study of Pekalongan Coastal Area in Central Java

Seawater intrusion promotes the degradation of groundwater quality through excessive pumping activities or natural phenomena such as tidal floods which are popular with coastal areas. Pekalongan city is one of the areas affected by this phenomenon and was analyzed in this study with reference to the 1986 Ad Hoc Sea Water Intrusion (PAHIAA) Decree which classifies water into five based on salinity. This involved using the Integrated Distance Method (IDW) to map and applying the logarithmic equation to determine the dispersion relationship. The results showed seawater intrusion has already affected groundwater quality up to 6.52 km from the coastline for total dissolved solids and electrical conductivity and 7.22 km for chloride ion. The distribution of TDS, EC, and Cl- in the freshwater zone was also recorded to have reached 28.59 km2, 28.36 km2, and 23.95 km2 respectively. It is predicted that in 4 years, there would no longer be freshwater in Padukuhan Kraton Village due to decreasing groundwater quality caused by seawater intrusion. Furthermore, 23.03 km2 Pekalongan area which spread into 4.34 km2 to the West, 0 km2 to the South, 14.39 km2 to the North, and 1.28 km2 to the East of the district has also been affected and was discovered to be caused mainly by tidal flood from Bremi and Tirto rivers.