338 research outputs found
The Foundation of the Right Bank in Wadi-Zarat Dam
The geotechnical engineering characteristics of a calcareous crust formation are evaluated in order to determine the feasibility of its stability under the right bank of Wadi Zarat Dam. The crust is a rock similar, extremely heterogeneous, material with location of collapsing susceptibility when saturated. The formation is caverned and locally very permeable and can present a risk of losing the reservoir water, dissolution, settlement, and piping. In this case study, several alternatives to treat the crust formation are presented, discussed, and compared. Rational justifications for the adopted solution are given and the predicted performance during operation of the dam is provided in order to be compared with the observed behaviour
Utilization of Synthesized Nano-Zinc Oxide in Yellow Basic Dye Decontamination from Industrial Wastewater
ZnO nanorod has been successfully synthesized through the reduction of Zinc chloride salt with ammonia solution in the presence of triethanolamine (TEA) as surfactant agent via hydrothermal technique. The properties of the produced material were determined using different characterization techniques such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared spectrum (FTIR). The results showed that the asprepared ZnO are rod- like morphologies at pH equal to 10. The synthesized nano rod-zinc oxide was employed asadsorbent agent for basic yellow 28 dye decolorization from polluted industrial wastewater. The synthesized nano-ZnO was achieved 93.26% dye decolorization affinity with in 60minutes. The variation in the different processing parameters on the dye sorption process was elucidated using batch technique. The increment in both the dye solution pH and its temperature was association with decline in the decolourization process. The optimum nano-zinc oxide dosage was recorded to be equal to 10 g/L. The adsorption data at equilibrium were analyzed using Langmuir, Freundlich and Temkin equilibrium isotherms. The experimental results confirmed the applicability of synthesized nano-zinc oxide as adsorbent agent for dye decontamination from polluted wastewater.Keywords: nano-zinc oxide, dye decolourization, sorption parameters
Computation of wave dispersion characteristics in periodic porous materials modeled as equivalent fluids
This paper starts with the presentation of the shift cell technique, which allows the description of the propagation of all existing waves starting from the unit cell through a quadratic eigenvalue problem. Its major advantage is that it allows the implementation of any frequency dependence and damping in the problem: this is a fundamental advantage when computing the dispersion curves of a porous material modeled as an equivalent fluid. The second part of this work concerns the investigation of the link between the dispersion curves and the acoustic properties of the material. Deriving the equivalent acoustic properties of the unit cell from its dispersion characteristics, indeed, could be a very efficient approach for designing the sound packages with a simple a preliminary eigenvalue analysis. Proceedings of ISMA 2018 - International Conference on Noise and Vibration Engineering and USD 2018 - International Conference on Uncertainty in Structural Dynamics. All rights reserved
Utilization of Synthesized Nano-Zinc Oxide in Yellow Basic Dye Decontamination from Industrial Wastewater
ZnO nanorod has been successfully synthesized through the reduction of Zinc chloride salt with ammonia solution in the presence of triethanolamine (TEA) as surfactant agent via hydrothermal technique. The properties of the produced material were determined using different characterization techniques such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared spectrum (FTIR). The results showed that the as prepared ZnO are rod- like morphologies at pH equal to 10. The synthesized nano rod-zinc oxide was employed as adsorbent agent for basic yellow 28 dye decolorization from polluted industrial wastewater. The synthesized nano-ZnO was achieved 93.26% dye decolorization affinity with in 60minutes. The variation in the different processing parameters on the dye sorption process was elucidated using batch technique. The increment in both the dye solution pH and its temperature was association with decline in the decolorization process. The optimum nano-zinc oxide dosage was recorded to be equal to 10 g/L. The adsorption data at equilibrium were analyzed using Langmuir, Freundlich and Temkin equilibrium isotherms. The experimental results confirmed the applicability of synthesized nano-zinc oxide as adsorbent agent for dye decontamination from polluted wastewater
Long-distance soliton transmission through ultralong fiber lasers
We present the first experimental demonstration (to our knowledge) of long-distance unperturbed fundamental optical soliton transmission in conventional single-mode optical fiber. The virtual transparency in the fiber required for soliton transmission, over 15 complete periods, was achieved by using an ultralong Raman fiber laser amplification scheme. Optical soliton pulse duration, pulse bandwidth, and peak intensity are shown to remain constant along the transmission length. Frequency-resolved optical gating spectrograms and numerical simulations confirm the observed optical soliton dynamics
Wave propagation in stereo-lithographical (STL) bone replicas at oblique incidence
Comparisons between predictions of a Biot-Allard model allowing for angle-dependent elasticity and
angle-and-porosity dependent tortuosity and transmission data obtained at normal incidence on
water-saturated replica bones are extended to oblique incidence. The model includes two parameters
which are adjusted for best fit at normal incidence. Using the same parameter values, it is found that predictions
of the variation of transmitted waveforms with angle through two types of bone replica are in
reasonable agreement with data despite the fact that scattering is not included in the theory
Long Term Strength and Durability of Clayey Soil Stabilized With Lime
This study deals with durability characteristics and unconfined compressive strength of clayey soil stabilized with lime. The tests comprises of unconfined compressive strength for samples stabilized with the optimum lime percent (4%), and subjected to cycles of the wet-dry, dry-wet and freeze-thaw durability tests as well as, long-term soaking and slake tests. The results indicated that, the efficiency of the lime in the improvement of unconfined compressive strength of clayey soil is of negative effect in the long term durability periods The wetting-drying cycles showed greater reduction in unconfined compressive strength than drying-wetting cycles, while the volume change of samples which subjected to drying at first, was greater than those conducted with wetting. On the other hand, freezing-thawing cycles causes a decreasing in the unconfined compressive strength values, and the reduction ratio was greater than wetting and drying cases. But, during soaking tests it was found that at early soaking periods, the lime stabilized samples continuously gaining strength, but beyond this the strength decreased with increasing soaking period. Finally, the stabilized samples with (4 and 6%) lime becomes more durable against the cycles of wetting and drying
Strength and Consolidation Characteristics of Compacted Clayey Soil Having a Special Case of Standard Compaction Curve
This paper deals with the results of an experimental study carried out on compacted clayey soil, to investigate the strength and consolidation characteristics of this soil. This soil having special case of standard compaction curve contain two values of maximum dry unit weight and two values of optimum moisture content between these point minimum dry unit weight was occurred.The results show that the maximum compressive and tensile strength lies on point near the point of second peak on standard compaction curve. Also the maximum bearing capacity and minimum settlement at the same point on standards compaction curve. Finally the preferred zone to conducted the compaction in field at this point where the dry unit weight at this point was 16.5kN/m3 while the moisture content was 18%
The impact of prior obesity surgery on glucose metabolism after body contouring surgery: A pilot study
Body contouring surgery enhances physical appearance by means of surgical subcutaneous fat removal (SSFR). However, it remains unclear how SSFR may affect glucose metabolism and its broader effects on the endocrine system, especially in individuals who have undergone obesity (bariatric) surgery. This study aimed to evaluate the impact of SSFR on glucose excursion and insulin resistance in such patients, by examining them over three visits (within 1 week before surgery, 1 week after surgery, and 6 weeks after surgery). The independent impact of SSFR and history of obesity surgery on glucose homeostasis was evaluated in 29 participants, of whom ten patients (34%) had a history of obesity surgery. Indices of glucose metabolism were evaluated using cluster robust-error logistic regression. Results indicated that SSFR led to a gross improvement in insulin resistance at 6 weeks after the surgery in all patient’s irrespective of BMI, type 2 diabetes mellitus (T2D) status, or history of obesity surgery (OR 0.22; p = 0.042). However, no effect was observed on glucose excursion except for a transient increase at visit 2 (1 week after surgery) in those without prior obesity surgery. Interestingly, participants with a history of obesity surgery had approximately half the odds being in the upper tertile for HOMA-IR (OR 0.44; p = 0.142) and ten-folds lower odds of having severely abnormal glucose excursion (OR 0.09; p = 0.031), irrespective of their BMI, T2D status, or time post SSFR. In conclusion, this study showed that body contouring surgery through SSFR resulted in (at least) short-term improvement in insulin resistance (independent of the participant’s BMI, T2D status, or history of obesity surgery) without affecting glucose excursion under the GTT. On the contrary, obesity surgery may have a long-term effect on glucose excursion, possibly due to sustained improvement of pancreatic ß-cell function
- …