A Comparative Study of the Immscible Density Currents Using the SPH And VOF-LES Methods

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Damage Tracking in Laboratory Reinforced Concrete Bridge Columns Under Reverse-cyclic Loading Using Fusion-based Imaging

Fusion-based imaging using ground-penetrating radar (GPR) and ultrasonic echo array (UEA) was employed to track damage progression in the columns of two full-scale reinforced concrete (RC) bridge column-footing subassembly laboratory specimens. The specimens had different lap-splice detailing and were subjected to reverse-cyclic lateral loading simulating a subduction zone earthquake. GPR and UEA scans were performed on the east and west faces of the columns at select ductility levels. Reconstructed images were obtained using the extended total focusing method (XTFM) and fused using a wavelet-based technique. Composite images of each column\u27s interior were created by merging the images from both sides. A quantitative analysis based on the structural similarity (SSIM) index accurately captured damage progression. A backwall analysis using the amplitude of the backwall reflector was also performed. Changes as early as in the first measurement (μ = 0.5 displacement ductility level) could be detected. Damage variation along the column height was observed, consistent with greater damage at the base. The proposed analyses distinguished the structural behavior differences between the two specimens. In summary, the SSIM metric provides a valuable tool for detecting changes, while the backwall analysis offers simple yet informative insights into damage progression and distribution in full-scale RC members

Assessment of chiton lamyi mollusk as a biological indicator of heavy metals such as Cd, Cu, As and Hg in the coast of Chabahar Bay

Mollusks are remarkably appropriate as a bio-indicator due to their wide geographical distribution, high abundance in benthic environments, selective absorption of certain ions and their motionless nature. Chiton, a mollusk of the phylum of Polyplacophora, and of its lamyi species is abundant in Chabahar Bay coastal rocks. Based on previous studies, this animal can be introduced as a potential indicator of Ecosystem Health; hence Chiton was chosen to be investigated rate of accumulation of metals, Cd, Cu, As and Hg in Chabahar Bay. After sampling four major stations, the samples were prepared and Cold Vapor Atomic Absorption apparatus were used for measurement of mercury and graphite furnace method was used for measuring other metals. Then, using the obtained data, bioaccumulation factor was calculated for each metal separately in the maximum amount of cadmium bioaccumulation factor at station 4 (Great sea) (136.34±0.02) and the lowest mercury at station 2 (Coast of Maritime University) (1.88±0.02), respectively. After statistical analysis of the results, it was found that Chiton can be introduced as a bio-indicator of the mentioned contaminants in the coast of Chabahar Bay

A comparative evaluation of dried activated sludge and mixed dried activated sludge with rice husk silica to remove hydrogen sulfide.

The aim of this study was to investigate the effectiveness of dried activated sludge (DAS) and mixed dried activated sludge with rice husk silica (DAS & RHS) for removal of hydrogen sulfide (H2S). Two laboratory-scale filter columns (packed one litter) were operated. Both systems were operated under different conditions of two parameters, namely different inlet gas concentrations and different inlet flow rates. The DAS & RHS packed filter showed more than 99.96% removal efficiency (RE) with empty bed residence time (EBRT) of 45 to 90 s and 300 mg/L inlet concentration of H2S. However, the RE decreased to 96.87% with the EBRT of 30 s. In the same condition, the DAS packed filter showed 99.37% RE. Nonetheless, the RE was shown to have dropped to 82.09% with the EBRT of 30 s. The maximum elimination capacity (EC) was obtained in the DAS & RHS packed filter up to 52.32 g/m3h, with the RE of 96.87% and H2S mass loading rate of 54 g/m3h. The maximum EC in the DAS packed filter was obtained up to 44.33 g/m3h with the RE of 82.09% and the H2S mass loading rate of 54 g/m3h. After 53 days of operating time and 54 g/m3h of loading rates, the maximum pressure drop reached to 3.0 and 8.0 (mm H2O) for the DAS & RHS packed and DAS packed filters, respectively. Based on the findings of this study, the DAS & RHS could be considered as a more suitable packing material to remove H2S

Use of nanomaterials in the pretreatment of water samples for environmental analysis

The challenge of providing clean drinking water is of enormous relevance in today’s human civilization, being essential for human consumption, but also for agriculture, livestock and several industrial applications. In addition to remediation strategies, the accurate monitoring of pollutants in water sup-plies, which most of the times are present at low concentrations, is a critical challenge. The usual low concentration of target analytes, the presence of in-terferents and the incompatibility of the sample matrix with instrumental techniques and detectors are the main reasons that renders sample preparation a relevant part of environmental monitoring strategies. The discovery and ap-plication of new nanomaterials allowed improvements on the pretreatment of water samples, with benefits in terms of speed, reliability and sensitivity in analysis. In this chapter, the use of nanomaterials in solid-phase extraction (SPE) protocols for water samples pretreatment for environmental monitoring is addressed. The most used nanomaterials, including metallic nanoparticles, metal organic frameworks, molecularly imprinted polymers, carbon-based nanomaterials, silica-based nanoparticles and nanocomposites are described, and their applications and advantages overviewed. Main gaps are identified and new directions on the field are suggested.publishe

Origin, transfer and distribution of cantharidin-related compounds in the blister beetle Hycleus scabiosae

Cantharidin provides chemical protection for the coleopteran families Meloidae and Oedemeridae. In the present study, it was observed that cantharidin concentration in Hycleus scabiosae was slightly decreased from mated females (mean = 0.011 mg/mg of dry weight) to males (mean = 0.010 mg/mg) and considerably diminished in relation to virgin females (mean = 0.005 mg/mg). Significant concentrations of palasonin (21.69 ng/mg among virgins and 17.49 ng/mg in mated females) and palasoninimide (14.62 ng/mg in virgins and 9.17 ng/mg in mated females) were found in H. scabiosae. Palasonin, palasoninimide and cantharidinimide content of eggs were measured as 5.61, 7.69 and 7.80 ng/mg respectively. Surprisingly, males showed no trace of cantharidin-related compounds (CRCs); therefore CRCs in H. scabiosae could not be transferred from males to females and based on experiments employing its deuterated form, cantharidin is probably independently synthesized in females from the male nuptial transfer. An inseminated female incorporates about 38.5 ng of cantharidin (0.34% of the maternal content), 196.35 ng of palasonin (91.82% of maternal content) and 269.15 ng of palasoninimide (96.70% maternal content) into each egg mass during oviposition. It seems that eggs of this meloid species exploit a different array of protective chemicals by increasing the ratio of CRCs versus cantharidin. CRCs are less toxic than cantharidin; therefore, such compounds might have been deposited in eggs as a safer substitute for cantharidin to provide effective protection, but does not simultaneously harm the susceptible embryo

Ergonomic assessment of some commonly used tractors in Iran

Introduction: Different models of tractors have been imported from foreign countries or assembled in Iran for many years. Consistency of foreign manufactured products with native specifications and the improvement of locally manufactured tractors are important problems that must be considered. Moreover, tractor dimensions, sitting space and some other important factors such as the ability of Iranian users to operate them must be taken into consideration. In this study, we surveyed the proper proportion of tractors dimension, location of control tools and driver’s work space, with Iranian users’ anthropometric data of drivers from five provinces. Human factors are of paramount importance in developing farm machinery given that these machines will often be operated by persons with minimum skills. Therefore, farm machinery should be made simple to operate and as free from hazards as possible. Materials and methods: Firstly, the anthropometric data for 250 users 20-60 years old was calculated. The drivers were selected randomly. Then the specifications of 4 tractors including: Ferguson 285, Ferguson 399, Valtra and New Holland were compared with the anthropometric data of user in 5th and 95th percentile value and their adaptation was studied. Anthropometric Data of subjects consisted of: standing height, full hand length, popliteal length, seat pan width, seat pan depth, elbow height, seat back support height, hand pan width, hand grip and full-leg length. Getting on the tractor is the first contact of an operator with a tractor. In assessing the suitability of the provision made for getting on the tractor, an experiment was arranged in which operators tried to get on 3 tractors. The mode of getting on the tractors, the agony on the operator’s face, the muscular reactions and individual opinion on the difficulties or comfort while undertaking the task were observed and recorded. The specifications of tractors compared with Anthropometric Data were measured, whiles the tractors were positioned on a level ground for measurements after the tires had been ganged. These specifications were tractor height, steering wheel height, footrest height, foot set height; tractor seat geometry as seat pan width, seat pan depth and seat pan support height; steering geometry as distance of steering wheel from seat reference point, steering wheel radius, steering wheel thickness, steering wheel inclination to the horizontal and seat reach adjustment; levers and pedals distance from seat reference point as gear lever, parking brake lever, hydraulic control lever, clutch pedal, accelerator pedal, brake pedal, front panel, workspace width and workspace length. Results and Discussion: The experiment that was conducted with operators attempting to get on the tractors indicated that tractor steps heights were higher than the desirable limit. Therefore, based on the ideas of the researcher and tractors drivers, getting on all tractors is difficult. With an increase in the number of steps or a decrease in their heights, the desirable condition can be created. Seat depth of new Holland and Valtra tractors were great for drivers in the 5th percentile value. A variable thickness pad can solve this problem. Results of studies indicated that Seat depth of Massey Ferguson 285 and 399 was shorter than driver’s leg length of 95th percentile value. To solve the problem an increase of 10 centimeters to pad height of these tractors was suggested. Seat pad of tractors were short for drivers in the 95th percentile value. Distance of steering wheel from seat reference point (SRP) in Massey Ferguson 285 and Valtra was further than drivers hand length in the 5th percentile value. Therefore, the drivers hand is short for driver’s good operation. Surveys indicated that drivers had problems for gear lever access in Massey Ferguson 399. Therefore, for good access on gear lever we must increase seat stroke range by 5-10 centimeters. The record available from Meteorological Organization indicated that air temperature and rain throughout the year in the study area is between 20 to 40degrees Celsius and 100to 300mm change. Valtra and New Holland tractors having a driver cabs with heating and cooling equipment have the ideal space for the performance of their driver. Massey Ferguson 285 tractor does not have any driver cab and Roll Over Protection Structure (ROPS). Conclusions: This research was conducted in five provinces of Iran to assess ergonomics of some commonly and new used tractors in Iran containing Ferguson 285, Ferguson 399, Valtra and New Holland. As there was no data base with required details, data was collected directly by personal contact with tractor users. A questionnaire was filled out for each person and anthropometric data was calculated in all provinces for 250 users 20-60 year old that were selected at random. Then relevant specifications of 4 tractors were measured and compared with the relevant anthropometric data of users in the 5th and 95th percentile value and their adaptation was studied. The results indicated that tractor steps, Seat depth, distance of steering wheel and distance of some levers and pedals from seat reference point should be amended

A Pipeline for Enhanced Multimodal 2D Imaging of Concrete Structures

We present an imaging pipeline to achieve enhanced images of the interior of concrete from ground penetrating radar (GPR) and ultrasonic echo array (UEA) measurements. This work lays the foundation for an advanced yet practical imaging tool to assess concrete structures. Specifically, we propose an enhanced two-dimensional (2D) total focusing method (XTFM) to reconstruct images from raw GPR and UEA data. The proposed XTFM algorithm integrates total focusing method (TFM) and synthetic aperture focusing technique (SAFT) concepts to post-process large independent and interelement measurements from both modalities in a computationally efficient way. Furthermore, we introduce a novel 2D image fusion algorithm using wavelet multilevel decomposition and an NDT knowledge-based rule to fuse GPR and UEA images. We then compare our algorithm with conventional fusion algorithms such as averaging, maximum, and product. The results from three laboratory concrete reference specimens are evaluated in detail. The fused images are compared with each other as well as benchmarked with the original GPR and UEA images. The output image obtained from our proposed pipeline is an enhanced 2D image of the interior of concrete structures that eases interpretation by a human inspector as well as it has the potential to improve interpretation by computer vision and image analysis algorithms

Fast Removal of Citalopram Drug from Waste Water Using Magnetic Nanoparticles Modified with Sodium Dodecyl Sulfate Followed by UV-Spectrometry

A simple and sensitive, solid-phase extraction method for the removal of Citalopram drug from waste water has been developed by using magnetic nanoparticles modified with surfactant sodium dodecyl sulfate. These magnetic nanoparticles have shown great adsorptive tendency towards Citalopram drug. The effect of different parameters influencing the extraction efficiency of this drug were investigated and optimized including the pH, amount of the surfactant, contact time and temperature. The extracts were analyzed by ultraviolet spectrophotometry at 239nm. Under these conditions, the related standard deviation (RSD %) of the method at two concentrations (5 and 50µg.mL-1) was in the range of (3.14–3.75) % (n = 8). The calibration curve was linear in the range of 2-100 µg.mL-1 of Citalopram drug with a correlation coefficient of >0.99

Radiation dose in cardiac SPECT/CT: An estimation of SSDE and effective dose

Aims The dose levels for Computed Tomography (CT) localization and attenuation correction of Single Photon Emission Computed Tomography (SPECT) are limited and reported as Volume Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP). This work presents CT dose estimation from Cardiac SPECT/CT based on new American Association of Physicists in Medicine (AAPM) Size Specific Dose Estimation (SSDE) parameter, effective dose, organ doses and also emission dose from nuclear issue. Material and methods Myocardial perfusion SPECT/CT for 509 patients was included in the study. SSDE, effective dose and organ dose were calculated using AAPM guideline and Impact-Dose software. Data were analyzed using R and SPSS statistical software. Spearman-Pearson correlation test and linear regression models were used for finding correlations and relationships among parameters. Results The mean CTDIvol was 1.34 mGy ± 0.19 and the mean SSDE was 1.7 mGy ± 0.16. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The mean ± SD of effective dose from emission, CT and total dose were 11.5 ± 1.4, 0.49 ± 0.11 and 12.67 ± 1.73 (mSv) respectively. The spearman test showed that correlation between body size and organ doses is significant except thyroid and red bone marrow. CTDIvol was strongly dependent on patient size, but SSDE was not. Emission dose was strongly dependent on patient weight, but its dependency was lower to effective diameter. Conclusion The dose parameters including CTDIvol, DLP, SSDE, effective dose values reported here are very low and below the reference level. This data suggest that appropriate CT acquisition parameters in SPECT/CT localization and attenuation correction are very beneficial for patients and lowering cancer risks. © 2016 Elsevier Ireland Lt