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Simultaneous Heat and Water Model (SHAW) is based on the assimilation rate of melting and/or freezing of the accumulated snow as well as melting of ice in soil. The main objective of this study was to evaluate applicability of SHAW Model in determining maximum depth of frost penetration in soils in some typical climates of Iran. To this end, the daily data of air temperature, soil temperatures at different depths, duration of bright sunshine, and air humidity were collected for the period of 1992-2003 for four meteorological stations of Iran including Shahr-e- Kord, Urumia, Sanandaj, and Yazd. Then, the maximum soil frost penetration depth (SFPD) for each year in the above mentioned stations was determined based on both the measured temperatures at different layers of soil and the calculated values using SHAW Model. Results of the analyses indicated that there was a significant linear relationship between the observed and the calculated values of maximum SFPD. The obtained coefficients of linear correlation between the observed and the calculated values for meteorological stations of Shahr-e-Kord, Urumia, Sanandaj and Yazd were 0.90, 0.77, 0.84 and 0.94, respectively, all being significant at one percent level. According to the results, it was concluded that, with the yearly records of weather parameters and soil conditions, a reliable estimate of the maximum annual depth of soil frost penetration can be made in similar regions of Iran by application of SHAW Model.

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It is necessary to investigate the concrete performance against impact loads due to increasing use of concrete in structure for available materials in many regions in one hand, and war or terroristic events on the other hand. Normal concrete has weakness against projectiles. For example spalling, scabbing and multiple impacts reduce concrete potential to tolerate imposing loads. Hence, improving normal concrete characteristics for better performance against these loads is essential. So, increasing compressive strength is the first alternative. However, numerous investigations reported that increasing compressive strength resulted in brittleness of the concrete. While, improving the performance of concrete against impact loads is contradictory to brittleness. One of the recommended alternatives for enhancing compressive strength of concrete and prevailing of its brittleness is reinforcing high-strength concrete by still fiber. In this study the performance of normal and high strength concrete with and without steel fiber was evaluated against the impact of ogive nose projectile with 7.62 mm caliber diameter, 12.5 gr weight and 830 m/s impact velocity. Concrete targets included 18 semi-infinite thickness cylindrical samples. Results showed that the pressure strength reduced in the SFRHSC samples as compared with NC samples. This is due to air locking in the samples which may be arise from the one: no suitable vibration for decreasing concrete slump, and the second: discontinuity in the concrete aggregates resulting from the steel fibers with improper aspect ratio. Results of the penetration tests showed that increasing compressive strength duo to reduction in water to cementitious materials ratio and partial replacing the cement with silica fume decreased penetration depth, crater diameter and volume as 10, 15 and 23%, respectively. While, adding of 0.5% steel fiber reduced penetration depth, crater diameter and volume as 7, 10 and 58%, respectively. Furthermore, in all no fiber steel samples expanded cracks and then sample collapse were observed. However, there were small cracks in fiber steel samples and damaged region was significantly reduced. In other words, about double increasing in compressive strength of concrete (from 452 to 860 kg/cm2) and 0.5% adding still fibers had a little effect on decreasing penetration depth and crack diameter. However, the effect of still fiber on depressing crack volume resulting from impact projectile was 252% more than increasing compressive strength (Figure 1). Furthermore, reinforced sample by still fiber were more :union: after impact projectile compared with the samples without still fiber which were disturbed completely (Figure 2). Finally, it may be concluded that for improving concrete performnace against impact loads including explosion and projectile impact, it is better to increase the compressive strength of concrete by using stronger aggregate such as cilice and quartz rather than decreasing water:cementitious ratio, increasing cement quantity and using silica-fume. Figure 1. Spalling crater volume in different concrete samples Figure 2. Crack extension in SFRC (left) and NC (right) samples

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Air entrainment in liquids via a fluid jet, is a complex phenomenon that has important applications in industry and the environment. The impact of a vertical laminar water jet translating over the quiescent pool of water at constant velocity was studied empirically, and the penetration depth as well as distribution of the bubbles formed by this jet was measured for both fresh and sea water with two different optical methods. This experiment was conducted at different flow rates (corresponding to different vertical velocities). In each case, the jet was moved at different horizontal velocities relative to the pool surface. As the jet started its horizontal translation, air began entering the pool from the bottom of the point of impact. Bubbles penetration depth was measured through a high-speed imaging technique, and pulse shadowgraphy was used for measuring the bubbles distribution. Increasing the vertical velocity of the jet while simultaneously decreasing the horizontal velocity of the same led to increased bubble penetration depths, and similar results were obtained for fresh water and sea water. This result was obtained in spite of the fact that the number and size of the bubbles formed in sea water were dramatically different from those formed in fresh water. Moreover, the significant role of buoyant forces in the distribution of the bubbles was obvious. The penetration depth and distribution of the bubbles were measured and reported for various jets with different diameters at different vertical and horizontal velocities.

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In recent years, infrared radiation (IR) has been considered as one of the suitable methods for drying and decontamination of different spices. However, the low penetration depth of the IR limits its use for food processing in the industry. Due to the importance of Carum carvi as a spice with medical properties, this research aimed to determine the effect of the sample’s structure (powder and seeds), water activity (0.24, 0.56 and 0.89) and the power of IR emitter (222 to 960W) on the penetration depth of the IR into Carum carvi For this propose, the heat fluxes received by copper black body that placed under samples with different thickness was measured. Afterward, the penetration depth was calculated through a mathematical model. The results indicated while aw of the sample, the IR power, and their interaction had a significant effect on the penetration depth of the IR, the structural properties of the sample had no significant effect on it. Increasing the infrared power to 601W enhanced the penetration depth in all of the samples. The highest penetration depth into the powder and the seeds of Carum carvi with aw 0.24 was achieved at the IR power of 601W, and was recorded 4.07±0.27 and 3.85±0.23mm while the samples with aw 0.89 were shown the highest penetration depth when they were irradiated by IR power of 845W) 4.12±0.18 and 4.09±0.13mm). According to the results, determining of IR penetration depth in the spice can be used to determine of their optimal thickness during the infrared food process.

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