Simulation of Liquid Flow Permeability for Dendritic Structures during Solidification Process

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Investigation on Phytoremediation Capability of Artiplex (Atriplex sp.) and Oleander (Nerium oleander) in Aradkooh Landfill for Cadmium and Lead

Intruduction Increasing industrial activities with the production of pollutants, including heavy metals, is one of the serious problems of modern communities, which has led to their accumulation in the environment. Heavy metals are also one of the important pollutants in landfill leachate. Plants and soil near the landfill may be contaminated by the leachate. Landfilling is the oldest method of solid waste disposal which can be a threat to the environment and health. Due to its easy operation and cost-effective, landfill is the most widely used method of municipal solid waste disposal in the world. Pollution cleaning technologies to reduce the harmful effects in the locations contaminated with heavy metals can be done by physical, chemical and biological methods. Phytoremediation, as a biological method, uses the green plants to extract, sequester, and detoxify pollutants. This method is a low-cost technique, environmentally friendly, and due to the non-production of by-products, is non-destructive for natural ecosystems. Considering the high moisture of wastes in Iran and their potential to produce leachate, as well as the possibility of contamination of water and soil in the landfill, especially with heavy metals, this study was conducted with the aim of evaluating the accumulation of lead (Pb) and cadmium (Cd) heavy metals in the soil, shoots and roots of artiplex (Atriplex sp.) and oleander (Nerium olander) plants in Aradkooh landfill of Tehran.   Materials and Methods This study was conducted in Aradkooh landfill which is located in the south of Tehran in the Kahrizak region. About 5200 tons of municipal solid waste were sent to this landfill every day. A part of the solid waste in Aradkoh was placed in various processes to energy and compost, and about 2500 tons of the solid waste was landfilled. According to previous reports, it is estimated that 250 cubic meters of leachate are produced daily in the Aradkoh landfill. In the studied landfill, there is an atriplex plant in four areas and a hand-planted oleander in one area. Ten samples of soil, root, and shoot, totaling 120 total were randomly selected from each growing area of the atriplex plant. Oleander shoots and soil were also tested from 10 different plants for a total of 40 samples. Then the levels of Cd and Pb in the soil, roots, and shoots were assessed. In this study, the outcomes were analyzed employing four key indices: the bioconcentration factor (BCF), the translocation factor (TF), the pollution index (PI), and PINemerow. The BCF and TF indices were employed to assess the phytoextraction and phytostabilization capabilities of plants, while the PI and PINemerow methods were used to pinpoint the most environmentally hazardous heavy metal in the soil.Results and Discussion  According to the results, the concentration of Pb and Cd in  shoots of atriplex  area 2 (with an average of 19.7 and 5.75 mg/kg, respectively) were significantly higher than in other areas, while the concentration of these metals in root of oleander (with an average of 8.17 and 1.06 for Pb and Cd, respectively) were higher than the shoot. The amount of Pb element in soil of the oleander plant (with an average of 35.13 mg/kg) and Cd in soil of the atriplex area 2 (with an average of 3.78 mg/kg) were significantly higher than other areas. Additionally, the levels of heavy metals in the soil of two plants were higher than the Nemerow index, which indicated high levels of pollution in the sampling areas, but still below the safe levels that was set by national standards (3.9 and 300 mg/kg for Cd and Pb respectively) and the World Health Organization (5 and 40 mg/kg for Cd and Pb, respectively). In addition, bioaccumulation factor of shoot in all growth atriplex areas for Pb and Cd (with an average of 1.44 and 1.3, respectively) were higher than 1.0 while, the root bioaccumulation factors of this plant in any of the growth areas, were not higher than 1.0. In the case of oleander, the shoot and root bioconcentration factors  for Pb and Cd were not reported more than one.   Conclusion In general, it appears that atriplex, a native plant in the Aradkooh landfill, exhibits superior capabilities for absorbing heavy elements compared to oleander. Therefore, atriplex seems well-suited for the extraction of Pb and Cd from the soil, as it can accumulate these metals in its shoots. In contrast, oleander is not well-suited for phytostabilization or phytoextraction of these elements, as it exhibits limited ability to accumulate these heavy metals in its roots and shoots. Consequently, atriplex can be a valuable choice as a resilient species for phytoremediation projects in landfills and areas near mines. It is worth noting that the Pb content in the soil is higher than that of Cd. Although both metals fall within the permissible limits of national and WHO standards, the soil in the Aradkooh landfill is considered to be significantly polluted based on the Nemerow index

Potential of Using Nanocarbons to Stabilize Weak Soils

Soil stabilization, using a variety of stabilizers, is a common method used by engineers and designers to enhance the properties of soil. The use of nanomaterials for soil stabilization is one of the most active research areas that also encompass a number of disciplines, including civil engineering and construction materials. Soils improved by nanomaterials could provide a novel, smart, and eco- and environment-friendly construction material for sustainability. In this case, carbon nanomaterials (CNMs) have become candidates for numerous applications in civil engineering. The main objective of this paper is to explore improvements in the physical properties of UKM residual soil using small amounts (0.05, 0.075, 0.1, and 0.2%) of nanocarbons, that is, carbon nanotube (multiwall carbon nanotube (MWCNTs)) and carbon nanofibers (CNFs). The parameters investigated in this study include Atterberg’s limits, optimum water content, maximum dry density, specific gravity, pH, and hydraulic conductivity. Nanocarbons increased the pH values from 3.93 to 4.16. Furthermore, the hydraulic conductivity values of the stabilized fine-grained soil samples containing MWCNTs decreased from 2.16E-09 m/s to 9.46E-10 m/s and, in the reinforcement sample by CNFs, the hydraulic conductivity value decreased to 7.44E-10 m/s. Small amount of nanocarbons (MWCNTs and CNFs) decreased the optimum moisture content, increased maximum dry density, reduced the plasticity index, and also had a significant effect on its hydraulic conductivity

Examination of the Behavior of Gravity Quay Wall against Liquefaction under the Effect of Wall Width and Soil Improvement

Deformation of quay walls is one of the main sources of damage to port facility while liquefaction of backfill and base soil of the wall are the main reasons for failures of quay walls. During earthquakes, the most susceptible materials for liquefaction in seashore regions are loose saturated sand. In this study, effects of enhancing the wall width and the soil improvement on the behavior of gravity quay walls are examined in order to obtain the optimum improved region. The FLAC 2D software was used for analyzing and modeling progressed models of soil and loading under difference conditions. Also, the behavior of liquefiable soil is simulated by the use of “Finn” constitutive model in the analysis models. The “Finn” constitutive model is especially created to determine liquefaction phenomena and excess pore pressure generation

Outcomes of Midurethral Slings in Women with Concomitant Preoperative Severe Lower Urinary Tract Voiding Symptoms

BACKGROUND: Women with stress urinary incontinence and concomitant obstructive (voiding) lower urinary tract symptoms (LUTS) represent a challenging patient population. Furthermore, their diagnosis and management remain incompletely studied and controversial. We evaluated the outcomes of midurethral sling procedures in women with severe obstructive LUTS. METHODS: We performed a post hoc analysis of women who were part of an institutional review board-approved study of midurethral sling surgery. Preoperatively and at 4-6 weeks postoperatively, patients completed the American Urological Association Symptom Score (AUASS) questionnaire. A postvoid residual urine test was obtained preoperatively, at the time of the voiding trial, and 4-6 weeks postoperatively. Three groups of patients with severe LUTS were then defined: Group A (AUASS \u3e/=20), Group B (voiding subscale \u3e/=12), and Group C (urodynamic obstruction). Patients could be included in more than one group. AUASS was again obtained at a medium-term follow-up of 31.6 months. RESULTS: Of 106 women completing follow-up, 30, 23, and 11 subjects met the criteria for groups A, B, and C, respectively. All had statistically significant improvements in storage and voiding subscales, as well as their stress urinary incontinence. No subject presented with retention or voiding dysfunction at follow-up. These improvements continued at medium-term follow-up with the exception of Group C that failed to demonstrate persistence of statistical improvement in AUASS subscales. CONCLUSION: Patients with stress urinary incontinence and severe voiding LUTS can be treated safely with midurethral sling procedures. In both the short and medium term, these symptoms improve dramatically in the majority of patients

Extraction and identification of steroids in two species marine algae, Sargassum oligocystum and Nizamudiinia zanardinii in Persian Gulf and Oman Sea

Sargassum oligocystum and Nizamudiinia zanardinii are the most abundant algae distributed in the north of Persian Gulf and Oman Sea. In this study after sampling and preparation of S. oligocystum by Chroform-Etanol (3-1) solvent and N. zanardinii by methanol has been extract. Separation and purification of the compounds was carried out using thin layer, general and inverse column chromatography, Cephadex and high-performance liquid chromatography (HPLC ). Structural elucidation of the constituents was based on the data obtained from HNMR, 13C-NMR, HSQC, HMBC, DEPT and Cephadex LH-20. The steroids compounds separated from above algae were identified as 22-dehydrocholesterol (1) cholesterol (2) fucosterol (3) 29-hydroperoxystigmasta-5,24(28)-dien-3β-ol (4) 24-hydroperoxy-24- vinylcholesterol (5) a mixture of 24(S)-hydroxy-24-vinylcholesterol (6) and 24(R)-hydroxy-24- vinylcholesterol (7) and ostreasterol (8) based on their spectral data and from comparison with those previously reported in the literature

A cell-free SDKP-conjugated self-assembling peptide hydrogel sufficient for improvement of myocardial infarction

Biomaterials in conjunction with stem cell therapy have recently attracted attention as a new therapeutic approach for myocardial infarction (MI), with the aim to solve the delivery challenges that exist with transplanted cells. Self-assembling peptide (SAP) hydrogels comprise a promising class of synthetic biomaterials with cardiac-compatible properties such as mild gelation, injectability, rehealing ability, and potential for sequence modification. Herein, we developed an SAP hydrogel composed of a self-assembling gel-forming core sequence (RADA) modified with SDKP motif with pro-angiogenic and anti-fibrotic activity to be used as a cardioprotective scaffold. The RADA-SDKP hydrogel was intramyocardially injected into the infarct border zone of a rat model of MI induced by left anterior descending artery (LAD) ligation as a cell-free or a cell-delivering scaffold for bone marrow mesenchymal stem cells (BM-MSCs). The left ventricular ejection fraction (LVEF) was markedly improved after transplantation of either free hydrogel or cell-laden hydrogel. This cardiac functional repair coincided very well with substantially lower fibrotic tissue formation, expanded microvasculature, and lower inflammatory response in the infarct area. Interestingly, BM-MSCs alone or in combination with hydrogel could not surpass the cardiac repair effects of the SDKP-modified SAP hydrogel. Taken together, we suggest that the RADA-SDKP hydrogel can be a promising cell-free construct that has the capability for functional restoration in the instances of acute myocardial infarction (AMI) that might minimize the safety concerns of cardiac cell therapy and facilitate clinical extrapolation. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

System Design and Locomotion of Superball, an Untethered Tensegrity Robot

The Spherical Underactuated Planetary Exploration Robot ball (SUPERball) is an ongoing project within NASA Ames Research Center's Intelligent Robotics Group and the Dynamic Tensegrity Robotics Lab (DTRL). The current SUPERball is the first full prototype of this tensegrity robot platform, eventually destined for space exploration missions. This work, building on prior published discussions of individual components, presents the fully-constructed robot. Various design improvements are discussed, as well as testing results of the sensors and actuators that illustrate system performance. Basic low-level motor position controls are implemented and validated against sensor data, which show SUPERball to be uniquely suited for highly dynamic state trajectory tracking. Finally, SUPERball is shown in a simple example of locomotion. This implementation of a basic motion primitive shows SUPERball in untethered control

Dietary intake of benzo(a)pyrene and risk of esophageal cancer in north of Iran

One etiologic factor for high incidence of esophageal squamous cell carcinoma (ESCC) in Golestan (Northeastern Iran) might be exposure to polycyclic aromatic hydrocarbons. We examined whether food and water are major sources of benzo(a)pyrene (BaP) exposure in this population. We used a dietary questionnaire to assess the daily intake of staple food (rice and bread) and water in 3 groups: 40 ESCC Golestan cases, 40 healthy subjects from the same area, and 40 healthy subjects from a low-risk area in Southern Iran. We measured, by high-performance liquid chromatography combined with fluorescence detection, the BaP concentration of bread, rice, and water in samples obtained from these 3 groups and calculated the daily intake of BaP. Mean BaP concentration of staple foods and water was similar and within standard levels in both areas, but the daily intake of BaP was higher in controls from the high-risk area than in controls from the low-risk area (91.4 vs. 70.6 ng/day, P < 0.01). In the multivariate regression analysis, having ESCC had no independent effect on BaP, whereas residence in the low-risk area was associated with a significant decrease in total BaP intake. Polycyclic aromatic hydrocarbons might, along with other risk factors, contribute to the high risk of ESCC in Golestan. Copyright © 2008, Taylor & Francis Group, LLC

Clinical significance of intraventricular gradient during effort in an adolescent karate player

The authors report the case of a 16-year-old boy who practices karate, who underwent medical evaluation because of atypical chest discomfort, related to strenuous effort. The ECG and echocardiogram findings were normal. The young boy did a treadmill stress test which was positive for myocardial ischemia. Late during the investigation, he underwent treadmill stress echocardiography, during which he developed intraventricular gradient of over 130 mmHg with end-systolic peak and systolic anterior movement (SAM) of the mitral valve. These echocardiographic findings were not present at rest and disappeared shortly after termination of exercise. The authors discuss the significance of this event. This leads us to advise withdrawal from participation in competitive sport according to the recomendations of the European Society of Cardiology. A possible role of exercise stress echo for intraventricular pressure gradient assessment in symptomatic athletes with structurally normal hearts is suggested