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The aim of soil mapping is to partition soil bodies using map units, which arc more homogenous for specific soil properties than arc the soil bodies as a whole. Soil properties arc expected to be similar at delineations of a specified soil map unit. Therefore, it is supposed that a model developed to estimate a soil property for one of these delineations could be generalised for the others. This study was conducted to determine the possibility of generalisation (extrapolation) of continuous models of spatial variability to estimate soil physical and chemical properties in similar delineations of a soil map unit. A consociation soil map unit in two different locations of a detailed soil map (1:20 000 scale), as similar delineations, was selected in the north-west of Faradonbch region, Iran. Sixty topsoil samples (0-20 cm) were randomly collected in each delineation (totally 120 samples) with 30-m intervals and the samples were GPS-recordcd. Laboratory studies consisted of bulk density, pH, calcium-carbonate equivalent, organic matter content, percentage of coarse fragments, and particle-size distribution. First, variography was done according to the soil data of each delineation (named areas A and B) and kriged maps were generated based on their own semivariogram parameters. Then, the kriged map of the soil properties for the second similar delineation (area B) was regenerated based on the corresponding models and their parameters obtained from the first similar delineation (area A). Finally, the regenerated kriged map of each variable was compared with its original kriged map. Visual comparison of the kriged maps of area B obtained from two steps of variography showed very high accordance for all of the soil properties. Quantitative comparison of the kriged maps suggests that the accuracy expected by the users of the soil information should be considered before generalisation of the data for similar units. Lower values of accordance obtained by the Kappa index and, especially, the classification success index than overall accuracy indicate that model generalisation should not be used where high precision of soil information is expected. Discrepancies observed for the kriged maps of the same variables in similar delineations could be due to different soil management practices in the past as a result of different historical developments. Additional keywords: continuous models, geostatistics, Kappa index, overall accuracy, soil map delineations., Introduction The idea of generalising (extrapolating) environmental variables was explored early (Prescott 1938), mainly to identify areas in the world with similar climates for crop production. The aim of soil [...]

Fifteen representative bridges throughout the state of Illinois were instrumented with foil strain gages to determine their frequencies of loading and the magnitudes of stresses induced by traffic over a 3- to 8-hour period, depending on traffic volume. Fatigue prone details, such as cover-plated wide flanges, were instrumented. For each stress range increment gathered by the data-acquisition system, the cumulative damage sustained over an extended number of years is compared with the number of available fatigue cycles for that stress range using published S = f(N) data for various details and the Palmgren-Miner linear damage rule. A new equation for factor of safety for welded structures subject to fatigue is proposed, taking dead load, live load, and bridge detail fatigue strengths into account. A new method of assessing future fatigue damage in bridges that takes traffic growth and increased truck weights into account is also proposed.

Various heavy metals have been reported as dangerous agents to the human health and wildlife when they occur in the environment at high concentrations. Cadmium and lead compounds are classified as human carcinogens by several regulatory agencies. Vegetables grown at environmentally contaminated sites could take up and accumulate metals at concentrations that are probably toxic to human health. In this study, concentrations of cadmium and lead in some of vegetables and soil samples were investigated in different areas of a developed industrial city in Isfahan province, Central Iran. One hundred and thirty topsoil samples and fifty samples of vegetables were collected from agricultural lands and analyzed for heavy metals. The concentration of Pb and Cd was more than 5 and 0.5 mg kg−1, respectively. The total of Cd concentration in most of the soil samples exceeded the suggested Swiss thresholds (0.8 mg kg−1). The results showed that 48% and 75% of the vegetables samples had concentrations of Cd and Pb exceeded the FAO-WHO limits, respectively. Results from the present study demonstrate that the most of the plants grown on the soils of this region, contaminated with heavy metals, and pose a major health concern.

Water entry is an interesting subject but many of its physical aspects have remained unknown so far. Using computational fluid dynamics (CFD), this study investigates the dynamic stability of cylindrical projectiles in the oblique water entry at shallow angles in the presence of three phases of air, water and water vapor. The three-dimensional and transient numerical model has been verified using the former experimental results in the literature. In this study, the effects of projectile length-to-diameter ratio (L/D) and water entry angle on the projectile stability within cavity were investigated. Accordingly, the water entry of six projectiles was simulated with aspect ratios of 2 to 6 at three water entry angles of 6, 9 and 12 degrees with respect to the free surface with an initial velocity of 280 m/s. At each of the aforementioned angles, the critical L/D, where the projectile avoids tumbling inside the cavity at a larger value, was determined. This study showed that in the oblique water entry of a cylindrical projectile at the angles of 6, 9 and 12 degrees, the projectile tumbled within the cavity with a L/D of less than 5, 4 and 3.5, respectively. The simulation results showed that increasing the L/D as well as the water entry angle relative to the free surface resulted in the improvement of the cylindrical projectile motion stability, which is in agreement with the experimental results. By analyzing the details of each simulation, it was found that the projectile stability within the cavity is correlated with the magnitude of the angular momentum which is generated in the projectile by the impact of the cavitator on the free surface and it was shown that the projectile with a specific L/D can withstand destabilizing angular momentum to a certain extent. Considering the fact that the atmospheric ballistics of gyroscopically stabilized projectiles lead to a limit for increasing L/D, this study showed that, for aluminum cylindrical projectiles in which air stability is achieved via the gyroscopic effect, the minimum water entry angle is 6° to attain the gyroscopic stability of the projectile in the air and stable motion inside the cavity. This fact is very important from a practical point of view. [ABSTRACT FROM AUTHOR]

BACKGROUND AND AIM: Traditionally lumpectomy as a part of breast-conserving surgery (BCS) is performed by palpation-guided method leading to positive margins and large excision volumes. There is no evidence suggesting that wide margin excisions decrease intra-breast tumour recurrence. Various perioperative techniques are used for margin assessment. We aimed to compare three commonly used techniques, i.e., ultrasound-guided surgery, palpation-guided surgery and cavity shaving for attaining negative margins and estimating the extent of healthy breast tissue resection. METHOD: A prospective comparative study was performed on 90 patients who underwent breast conservation surgery for early breast cancer between August 2018 and June 2019. Tumour excision with a minimum of 1 cm margin was done either using ultrasound, palpation or cavity shaving. Histopathological evaluation was done to assess the margin status and excess amount of resected normal breast tissue. Calculated resection ratio (CRR) defining the excess amount of the resected breast tissue was achieved by dividing the total resection volume (TRV) by optimal resection volume (ORV). The time taken for excision was also recorded. RESULTS: Histopathology of all 90 patients (30 in each group) revealed a negative resection margin in 93.3% of 30 patients in palpation-guided surgery group and 100% in both ultrasound-guided surgery and cavity shaving groups. Two patients (6.7%) from the cavity shaving group had positive margins on initial lumpectomy but shave margins were negative. TRV was significantly less in the ultrasound-guided surgery group compared to the palpation-guided surgery group and cavity shaving group (76.9 cm3, 94.7 cm3 and 126.3 cm3 respectively; p < 0.0051). CRR was 1.2 in ultrasound group compared to 1.9 in palpation group and 2.1 in cavity shave group which was also statistically significant (p < 0.0001). Excision time was significantly less (p < 0.001) in palpation-guided surgery group (13.8 min) compared to cavity shaving group (15.1 min) and ultrasound-guided group (19.4 min). CONCLUSION: Ultrasound-guided surgery is more accurate in attaining negative margins with the removal of least amount of healthy breast tissue compared to palpation-guided surgery and cavity shaving. [ABSTRACT FROM AUTHOR]

Estimating forest attributes is essential for understanding the condition and function of the forest to be applied in forest planning and management. The purpose of this study was to estimate the structural attributes of conifer-dominated plantations using radio detection and ranging (RADAR) polarimetric data and nonparametric algorithms in the Arabdagh region of Golestan province. Field-based structural attributes were collected from 319 circular plots with 400 m2 areas designed within a random cluster method. Within each plot, diameter at breast height (for all trees) and height (for some trees) were measured. The precise position of plots ere also recorded. Then stand volume, basal area, and the number of stem per ha were calculated. The required preprocessing and processing were conducted on raw RADAR data, followed by the extraction of plot-based values from the derived indices. Model training was done on 75% of plots using random forest, support vector machine, and K nearest neighbor algorithms. Results were validated with the remaining 25% of the plots. The results showed the lowest Root Mean Square Error and Bias for Random Forest algorithm for basal area 50.62% and -1.7%, respectively. Moreover, the support vector machine model achieved 58.82% and -7.94% for volume as well as 52.07% and -5.1% for no. of trees per hectare. As a whole, this study showed that the full polarization PALSAR-2 data has a moderate ability to estimate the quantitative structural attributes due to the high amplitude of changes in the quantitative forest characteristics. [ABSTRACT FROM AUTHOR]