Numerical investigation of sand erosion rate in a horizontal axis wind turbine.

Renewable energy represents an important alternative solution for many energy problems nowadays and a tool for a healthier environment by reducing carbon footprints resulting from burning fossil fuels. However, more work needs to be done towards maximizing the energy produced from renewable energy methods and making sure that the infrastructure used stays in service for a longer duration. Sand erosion phenomena is responsible for the degradation of the wind turbine blades and hence the decrease in their performance and life. In the current research, a numerical study of both performance and sand erosion of a Small-Scale Horizontal Axis Wind Turbine (SS-HAWT) is carried out. This study introduces new sights of instantaneous and forecasted erosion rates within the blade of the wind turbines. Three-dimensional E216 airfoil blades of radius 0.5 m are established according to blade element momentum theory. Sand particles with different mass flow rates of 0.001, 0.002 and 0.003 kg/s and uniform diameters of 50, 100 and 200 µm have been selected as eroding particles under two different average air velocities of 8 m/s and 10 m/s. The results indicate that the performance of wind turbines is enhanced as the flow separation at the suction side is shifted to the trailing edge. Furthermore, the optimum tip speed ratio is about 5 at an air velocity of 8 m/s with a power coefficient of 0.432. In terms of erosion findings, V-shaped scars are reported near the leading edge of the blades. In addition, the instantaneous erosion rate grows exponentially with the tip speed ratio. Therefore, the yearly prediction of maximum erosion depth at the optimum operating conditions is obtained to be 5.7 mm/year in some spots of the turbine blades.

Removal of malachite green from wastewater using date seeds as natural adsorbent; isotherms, kinetics, Thermodynamic, and batch adsorption process design.

This research explores the feasibility of using date seeds (DS), an agricultural waste, for the adsorption of malachite green (MG) dye from synthesized wastewater. The characterization of the DS before and after adsorption was accomplished by FTIR, SEM, BET, and EDX measurements. Batch adsorption experiments were investigated for MG dye adsorption from aqueous solution onto the DS. The effect of different parameters such as solution pH, adsorbent dose, contact time, temperature, and the initial dye concentration were studied. The optimum pH, adsorbent dose, temperature, and contact time for the dye removal were found to be 5, 0.1 g, 25 °C, and 30 min, respectively. The equilibrium studies for the data with Langmuir, Freundlich, and Temkin isotherms showed that Freundlich isotherm is the best model to describe the adsorption of MG onto the DS particles which has a heterogeneous surface. It was found that the adsorption process follows a pseudo-second-order kinetic model which revealed that the intra-particle diffusion stage is the rate-controlling stage for the process. The thermodynamic parameters ΔG, ΔS, and ΔH suggest the possibility of chemisorption and physisorption simultaneously and indicate the exothermic and spontaneous characters of the adsorption of MG dye on DS with negative values of ΔH and ΔG.

This study used agriculture waste (date seeds) which is proved to be an environmentally friendly and low-cost adsorbent. The date seeds were shown to be a promising adsorbent, demonstrating high surface area and well-developed porosity. The prepared adsorbent will have a great impact on wastewater treatment technology and possible applications at a large scale. Thus, widespread and great progress in this area can be expected in the future.

Raw sawdust utilization for the removal of acid red57 and basic fuchsin dyes from aqueous solution: equilibrium, kinetics, and thermodynamic investigation.

The aim of work is the use of a cheap adsorbent; sawdust (SD), for the adsorption of anionic dye, acid red57 (AR57), and cationic dye, basic fuchsin (BF). The adsorption of AR57 and BF on SD increased by increasing contact time and adsorbent dosage, while decreased with the increase of temperature and initial dye concentration. The increase in pH decreased the adsorption of AR57 and increased the adsorption of BF. The effective pH, adsorbent dose, and contact time on the AR57 removal efficiency were found to be 3, 0.1 g and 50 min, respectively. While for BF it was found to be 6, 0.2 g and 50 min, respectively. Fitting equilibrium data to Langmuir, Freundlich and Temkin isotherms showed that Freundlich model is the most suitable to describe the acid red57 and basic fuchsin. The kinetic studies indicate that the adsorption of AR57 and BF follows a pseudo-second-order model. The adsorption of both AR57 and BF is spontaneous (ΔG = -3.97, -3.27 kJ/mol) and exothermic (ΔH = -22.9, -8.3 kJ/mol) with negative values of ΔG and ΔH. The negative values of ΔS of both AR57 and BF (ΔS = -64.6, -16.7 J/mol. K) showed that the randomness decreases through the adsorption process.

SD is locally available in Egypt - Damietta, as solid residue and it is very cheap, therefore there is no need for its regeneration and reuse because of its nearly free cost and safe disposable. On the other hand, the treated waste liquids reach satisfied limits for reusing in the agriculture of palm trees.

Safety of nurse-directed triage intranasal fentanyl protocol for acute pain management in a European pediatric emergency department: A retrospective observational analysis.

Background: Nurse-directed pain protocols for intranasal fentanyl administration are not widely implemented in European (EU) pediatric emergency departments (PED). Barriers include perceived safety concerns for intranasal (IN) fentanyl. The aim of this study is to describe our experience with a nurse-directed triage IN fentanyl protocol with a focus on safety in a tertiary EU PED. Methods: We conducted a retrospective analysis of patient records of children aged 0-16 years who received nurse-directed IN fentanyl between January 2019 and December 2021 at the PED of the University Children's Hospital of Bern, Switzerland. Extracted data points included demographics, presenting complaint, pain score, IN fentanyl dosage, concomitant pain medication use, and adverse events. Results: A total of 314 patients were identified with ages ranging from 9 months to 15 years. The main indication for nurse-directed fentanyl administration was musculoskeletal pain due to trauma (n = 284, 90%). Mild adverse events (vertigo) were reported in two patients (0.6%), without a correlation to concomitant pain medication or protocol violation. The only reported severe adverse event of syncope and hypoxia in a 14-year-old adolescent occurred in a setting where the institutional nurse-directed protocol was violated. Conclusion: In accordance with previous studies outside of Europe, our data support the case that when appropriately used, nurse-directed IN fentanyl is a safe potent opioid analgesic for pediatric acute pain management. We strongly encourage the introduction of nurse-directed triage fentanyl protocols Europe-wide in order to provide effective and adequate acute pain management in children.

Prevalence of Eustachian Tube Dysfunction and Its Associated Factors Among the General Public in Al-Madinah, Saudi Arabia.

Objectives To determine the association between patient demographics including gender, age, family history of hearing loss, and eustachian tube dysfunction (ETD) in the Al-Madinah region. Methods This is a cross-sectional observational study that was conducted using an online survey in the Al-Madinah region of Saudi Arabia from March 2022 to August 2022. Data were collected using a self-administered questionnaire (ETDQ-7) that was designed based on previous studies and frameworks. It consists of seven items, each with a score ranging from 1 to 7, for a total score of between 7 and 49 points. A total score of 14.5 or above, or a mean domain score of 2.5 or above, is considered abnormal, with higher scores indicating greater severity of symptoms. The analysis was carried out using SPSS v23. Results About 380 participants were included in the current study. The mean age of the participants was 29.2 ± 8.7 years old. About 13 (3.4%) of the participants had a history of ETD. The prevalence of ETD among the study population was 41.3%. Gender was significantly associated with the prevalence of ETD (p-value=0.004), with females tending to have the condition more frequently than males. Moreover, the history of ETD was also significant (p=0.001) Conclusion A higher prevalence of ETD was found in the current study when compared to international studies, gender and history of ETD were found to be linked with increased prevalence of EDT.

Transformative effect of a Humanitarian Program for individuals affected by rare diseases: building support systems and creating local expertise.

Rare diseases affect > 400 million people globally with a disproportionate burden falling on children, resulting in high morbidity and mortality rates. Affected individuals in some under-resourced countries have limited access to expert care or treatments; moreover, they suffer long diagnostic journeys during which debilitating and life-threatening complications occur. Lysosomal storage disorders (LSD) are prototype rare diseases due, in the main, to inherited deficiencies of lysosomal enzymes/transporters that affect up to 1 in 5000 newborns. Recognizing the need to provide treatment access to people with LSDs everywhere, a collaborative partnership was pioneered and set up 30 years ago. Partnering with local authorities, non-government organizations across six continents, local as well as international experts, a robust, sustainable Humanitarian Program emerged that now represents the most enduring charitable access program for LSD treatment. Here we present the history, process, lasting beneficial effect of the program to develop healthcare systems and infrastructures, and the lessons learned from addressing major unmet needs for LSDs.

The pan-immune-inflammation value and systemic immune-inflammation index in advanced melanoma patients under immunotherapy.

PURPOSE: To evaluate the pan-immune-inflammation value (PIV) and systemic immune-inflammation index (SII) in patients with cutaneous melanoma (CM) under immune checkpoint inhibitor (ICI) therapy. METHODS: PIV and SII were calculated before the start of ICI therapy and at time of progression/death in patients with metastatic CM (stage III/IV). Sex-age-matched CM patients in stage I/II and healthy subjects (HC) served as controls. RESULTS: The median PIV of stage III/IV patients was significantly (P = 0.0011) higher than in stage I/II patients and HC. SII was significantly (P = 0.00044) lower in HC than in CM patients. At baseline, PIV and SII did significantly correlate with lactate dehydrogenase (P = 0.045/0.017). However, ROC curve statistics revealed that SII and PIV were not significantly associated with clinical parameters, including best response to ICI treatment (P = 0.87/0.64), progression-free survival (P = 0.73/0.91), and melanoma-specific survival (P = 0.13/0.17). Moreover, there were no significant changes of PIV and SII from baseline to progression/death (P = 0.38/0.52). CONCLUSIONS: Even though both immune-inflammation biomarkers showed some power to differentiate between CM stages and HC, respectively, PIV and SII seem not to be significant predictors for clinical outcome measures of CM patients under ICI therapy.

An Impact study of highway design on casualty and non-casualty traffic accidents.

Background Road Safety has become a worldwide concern due to the alarming repercussions road accidents may bear. This study examined the relationship between different geometric design elements and the accident rates on Rashid Bin Saeed Street, Arabian Gulf Street, and Sultan Bin Zayed Street in Abu Dhabi, United Arab Emirates. Methods The geometric design was collected from the satellite images of google earth in compliance with the standard geometric design manual of Abu Dhabi roads. The recorded geometric data consisted of the number of lanes, lane widths, median length, and width. The traffic volume data was provided by the Integrated Transport Center of Abu Dhabi, which was then converted into Annual Average Daily Traffic (AADT) for analytical purposes. For the studied roads, AADT ranges ranged between 26,509 and 121,890 vehicles per day. The crash data related to the period of 2012-2019 was collected from the online open-access data provided by the United Arab Emirates Ministry of Interior. The data provided had considered variables related to driver gender, age and speed, travel direction, and time of the day amongst other factors. A comprehensive statistical analysis was conducted to study the impact of geometric design elements on road safety through a stable distribution. Stable distributions are generally characterized by four parameters and expressed as X∼S(α,ß,σ,µ). The statistical model included several graphical representations such as accident frequency at two levels of severity, casualty and non-casualty accidents for different road segments, traffic volumes, day of the week, age of the injured person, and the geometric design parameters on the three roads. Variance-based methods of sensitivity analysis are also used that are a class of probabilistic approaches that quantify the input and output uncertainties as probability distributions and decompose the output variance into parts attributable to input variables and combinations of variables. The sensitivity of the output to an input variable is therefore measured by the amount of variance in the output caused by that input. Findings The results showed that the accident profiles differ with varying segments on each road, revealing some segments to be of higher accident rates than others. Also, a higher accident frequency was shown with young adult drivers, and a high majority of accidents had occurred on weekends. Regarding the road's geometric design, which is the focus of this study, a sensitivity analysis was made to determine the most influential geometric design element on accident frequency. Interpretation The number of lanes had the highest sensitivity index followed by the median width, and then came the lane width. Thus, modifying the number of lanes on a highway is anticipated to have the highest impact on accident frequency and road safety than any other geometric parameter.

Musculoskeletal radiology training in the UK: a national survey by the British Society of Skeletal Radiologists.

AIM: To identify the standard of core and subspecialist musculoskeletal (MSK) training across deaneries in the UK. MATERIALS AND METHODS: An online survey of 46 questions with responses in Likert scale or dichotomous formats was distributed to members of the Society of Radiologists in training, British Society of Skeletal Radiologists (BSSR), Training Programme Directors and the Royal College of Radiologists (RCR) Junior Radiology Forum representatives for national training schemes across the country. Responses were analysed descriptively with narrative analysis of free-text comments. RESULTS: One hundred and seventy-eight participants completed the survey. Forty-six percent (81/178) were core trainees (ST1-3), 47% (84/178) were subspecialist trainees, and 7% (13/178) were newly qualified consultants (<2 years in post). All (178/178) of the participants had a dedicated MSK rotation, with a duration of ≥3 months in 76% (136/178). Only one-third received a dedicated period in MSK ultrasound and only 60% (107/178) had been actively involved in interventional procedures during their training. Overall, 21% (37/178) and 42% (75/178) of participants rated the quality of their MSK training as excellent and good, respectively. The majority (93%, 168/178) thought that MSK training could be improved, especially for ultrasound (62%, 110/178) and interventional computed tomography (CT) or fluoroscopy (57%, 101/178). CONCLUSIONS: There are inconsistencies in MSK training offered in the UK. Although the majority of trainees are satisfied, there were gaps and potential threats to the quality of training. MSK training is witnessing substantial demand from trainees and workforce strategists necessitating tactical investments to standardise and enhance its quality.

Development of a Resonant Microwave Sensor for Sediment Density Characterization.

In this study, a sensor based on the development of a planar antenna immersed in sediments dedicated to water content monitoring in this type of material is proposed and experimentally validated. It is produced by a conventional Printed Circuit Board (PCB) manufacturing process on a double-sided metalized FR4 substrate. The sensitivity of the sensor is ensured by the variation of the real part of the complex dielectric permittivity of sediments with water content at around 1 GHz. As shown, in this frequency range, electrode polarization and Maxwell-Wagner polarization effects become negligible, leading to only a bulk water polarization sensitivity. The sensor operates in the reflection mode by monitoring the variation of the resonant frequency as a function of the sediment density through the S11 reflection measurements. An experimental sensitivity of 820   MHz . g - 1 . cm 3 was achieved. Despite the simplification of data interpretation at the considered frequency, the influence of ionic species such as NaCl in sediments on the real part of the relative complex dielectric permittivity is highlighted. This demonstrates the importance of considering a second parameter such as the S11 level at low frequency or the electrical conductivity to extract the density from the frequency measurements.

Experimental study on the adsorption of Cr+6 and Ni+2 from aqueous solution using low-cost natural material.

The adsorption behavior of Chromium (Cr)(VI) and Nickel (Ni)(II) from aqueous solution onto date pits (DPs) was investigated as a function of initial concentration (5-100 mg/L), contact time (0-70 min), adsorbent dose (2-20 g/L), pH (1-9), and temperature (25-95[Formula: see text] Equilibrium took place after 45 and 55 min for Cr(VI) and Ni(II), respectively. The removal efficiency reached 100% and 95% for Cr(VI) and Ni(II), respectively, at optimal conditions. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analyses were performed to characterize the adsorbent. The Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich (D-R) models were applied to describe the equilibrium isotherms. The values of the free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) were 34.599 kJ/mol, 17.5736 kJ/mol K, and -51.58 kJ/mol K, respectively, at pH 3 for Cr(VI) and -25.283 kJ/mol, -14.8525 kJ/mol K, and 31.31 kJ/mol K, respectively, at pH 6 for Ni(II). Kinetics of the adsorption was analyzed. The pseudo-first-order was suitable for Cr(VI) at R2 = 0.9977, and the pseudo-second-order model was suitable for the Ni(II) at R2 = 0.999. The maximum adsorption capacities were 110.02 mg Cr(VI)/g and 10.1 mg Ni(II)/g. A single-stage batch adsorber was designed for the adsorption of Cr(VI) and Ni(II) by DP based on the optimum isotherm.

Investigation of the effect of magnetite iron oxide particles size on cytotoxicity in A549 cell line.

INTRODUCTION: Magnetite as iron oxide is widely used in various industries, in the pharmaceutical industry in particular where it is used for its magnetic properties. The environmental and occupational exposure to airborne nanoparticles and microparticles of iron oxide compounds have been reported. Since authors have reported contradictory results, the objective of this study was to investigate the effect of particles' size in their toxicities. METHODS: The human cell line A549 was exposed with magnetite iron oxide in two size categories of micro (≥5 µm) and nano (<100 nm), with four concentrations of 10, 50, 100, and 250 µg/ml at two time periods of 24 and 72 h. The cell viability, reactive oxygen species (ROS), changes in mitochondrial membrane potential, and incidence of apoptosis were studied. RESULTS: Nano and micro magnetite particles demonstrated diverse toxicity effects on the A549 cell line at the 24- and 72-h exposure periods; however, the effects produced were time- and concentration-dependent. Nano magnetite particles produced greater cellular toxicities in forms of decreased viabilities at concentration exposures greater than 50 µg/ml (p < 0.05), along with increased ROS (p < 0.05), decreased cellular membrane potential (p < 0.05), and reduced rate of apoptosis (p < 0.05). DISCUSSION: The results of this study demonstrated that magnetite iron in nano-range sizes had a greater absorbability for the A549 cell line compared to micro sizes, and at the same time, nanoparticles were more toxic than microparticles, demonstrating higher production of ROS and decreased viabilities. Considering the greater toxicity of nanoparticles of magnetite iron in this study, thorough precautionary control measures must be taken before they can be used in various industries.

The effect of single and combined exposures to magnetite and polymorphous silicon dioxide nanoparticles on the human A549 cell line: in vitro study.

The increasing trend of nanoparticle usage in science and technology has led to significant human exposure. Occupational exposure to iron oxides and silica dust has been reported in mining, manufacturing, construction, and pharmaceutical operations. The combined toxicological effects of nanoparticles and simultaneous exposure to other compounds have given rise to a new concern. Hence, the objective of this study was to investigate the toxicological effects of magnetite and polymorphous silicon dioxide nanoparticles in single and combined exposures. The polymorphous silicon dioxide nanoparticles were obtained from the milled quartz particles under 100 nm in diameter. The milled particles were purified through chloric and nitric acid wash processes. The toxic effects of the magnetite nanoparticles were investigated independently and in combination with quartz using the A549 cell line for durations of 24 and 72 h, and using diverse concentrations of 10, 50, 100, and 250 µg/mL. MTT, ROS, mitochondrial membrane potential, and cell glutathione content assays were used to evaluate the amount of cell damage in this study. The statistical significance level in one-way ANOVA and independent t test was considered to be at the 5% confidence level. The size and purity of polymorphous silicon dioxide nanoparticles were measured by TEM and ICP-OES analysis, respectively. The particles' diameters were under 100 nm and demonstrated a purity of higher than 99%. The toxicity results of this study showed a dependency on concentration and exposure duration in reducing the cell viability, cellular glutathione content, and mitochondrial membrane potential, as well as increasing the ROS generation in single and combined exposures with magnetite and polymorphous silicon dioxide nanoparticles. The toxic effects of combined exposure to these nanoparticles were less than the single exposures, and statistically significant antagonistic interactions were detected. Combined exposure to polymorphous silicon dioxide and magnetite nanoparticles, in comparison with their single exposures, could affect health in an antagonistic manner. Since this study has been the first of its kind, further studies investigating the health effects of single and combined exposures to these compounds are needed to verify our findings. Generally, studies such as this one could contribute to the field of combined toxicity effects.

Ultrasound-Guided Continuous Radiofrequency Ablation Of Painful Residual Limb Neuroma In Individuals With Limb Amputation-A Retrospective Case Series.

BACKGROUND: Residual limb neuromas are a significant cause of post-amputation pain. There is little knowledge concerning ultrasound-guided (US) radiofrequency ablation (RFA) as treatment. OBJECTIVE: To investigate US-guided RFA for neuroma associated pain in individuals with limb amputation. METHODOLOGY: The notes of nine consecutive patients were retrospectively reviewed. Information obtained included neuroma size and nerve, RFA duration/temperature, pain scores, analgesic requirements and ease/comfort of prosthetic use. Eight patients had lower-limb amputations and one had a trans-radial amputation. All except one, underwent diagnostic US-guided steroid injection to confirm the neuroma as the source of pain, prior to RFA. RESULTS: Six patients reported significant reduction in pain scores (defined as at least 50% reduction) and an improvement in comfort/ease of wearing their prosthetic limb, with no adverse effects. Three of these six patients also reported a reduction in analgesic requirements. Of the three remaining patients - one had a large sciatic nerve neuroma that was eventually surgically excised, another had confounding pain from an adjacent bony spur, whilst the third patient did not receive a routine diagnostic steroid injection prior to RFA. CONCLUSIONS: Our findings suggest that US-guided RFA is safe and effective for small to medium-sized residual limb neuroma associated pain in individuals with limb amputation. It can reduce pain and analgesic requirements, improve comfort/ease of wearing the prosthesis and potentially avoid surgical excision. We recommend patients should undergo a diagnostic steroid injection prior to RFA to confirm that the neuroma is the source of pain.

Occupational Exposure to Respirable Dust, Crystalline Silica and Its Pulmonary Effects among Workers of a Cement Factory in Kermanshah, Iran.

BACKGROUND: Although the main hazard in cement processing is dust, and its effects on pulmonary function constitute the most important group of occupational diseases in this industry, evidence for association between exposure to cement dust and pulmonary function has not been conclusive. This study was performed with the aim to evaluate the impact of cement dust in the workplace on decreasing pulmonary function parameters among the workers. MATERIALS AND METHODS: In this cross-sectional study 283 workers were studied, of which 140 workers were considered as exposed group and 143 workers as non-exposed group. Fifty samples of respirable dust were collected from breathing zone of workers in different sections of cement factory. Visible absorption spectrophotometry was used according to the NIOSH Method 7601 to measure crystalline silica content of reparable dust samples. Spirometry test was also applied to assess workers' pulmonary function parameters. RESULTS: Respirable dust concentration was in the range of 1.77 to 6.12 mg/m3. The concentration of crystalline silica in all units was higher than the Threshold Limit Value (TLV) (0.025 mg / m3). There were a significant difference in the Peak Expiratory Flow (PEF) parameter among workers in the two exposed and non-exposed groups to respirable dust (P= 0.017). In other parameters of pulmonary function (FVC, FEV1, FEF 25-75, FEV1/FVC %), there were no significant differences between the two groups under study (P= 0.45, P= 0.14, P= 0.29 and P= 0.23, respectively). CONCLUSION: The findings of this study have provided an evidence to confirm the hypothesis that exposure to cement dust can cause complication in PEF parameter of cement industry workers.

Comparing laparoscopic and percutaneous renal biopsy for diagnosing native kidney disease: A matched pair analysis.

BACKGROUND: Percutaneous renal biopsy is a well-established diagnostic procedure in patients with underlying medical renal disease. Aim of this study is to compare the adequacy of the biopsy material, the diagnostic yield, and the complication rates of the trans-peritoneal laparoscopic approach and the image-guided percutaneous approach to renal biopsy in the diagnosis of native kidney disease. METHODS: We performed a matched-pair analysis matching 1:3 40 patients who underwent trans-peritoneal laparoscopic renal biopsy to 120 patients who underwent percutaneous renal biopsy in the same years. Patients were retrospectively analyzed. Differences in adequacy of biopsy material (i.e. number of glomeruli, continuous), diagnostic yield (categorical) and postoperative complications across the two groups were assessed using Wilcoxon Rank sum or χ2 test. RESULTS: Laparoscopic biopsy was associated with a higher number of harbored glomeruli (median 50, IQR 20-77) compared to the percutaneous approach (median 10, IQR 7-15), P<0.001. Adequate biopsies containing at least ten glomeruli were obtained in a significantly higher percentage of patients in the laparoscopic group versus the percutaneous group (92.5% vs. 57.1%, P<0.001). The laparoscopic approach was also associated with a significantly higher diagnostic yield than the percutaneous approach (82.5% vs. 63.5%, P=0.027). Patients who underwent laparoscopic biopsy had no perioperative or postoperative complications, resulting in a significantly lower complication rate than percutaneous biopsy (0% vs. 4%, P<0.001), particularly in the need for transfusion for post-procedure bleeding (0% vs. 1.8%, P<0.001). CONCLUSIONS: In this retrospective matched-pair analysis comparing patients undergoing renal biopsy for medical kidney disease, trans-peritoneal laparoscopic renal biopsy was safer and more effective for the diagnosis of medical renal diseases compared to percutaneous renal biopsy. Prospective trials with a good follow-up are needed to define the best candidate for each approach. LEVEL OF EVIDENCE: 4.

Adsorption of cationic dye from aqueous solutions by date pits: Equilibrium, kinetic, thermodynamic studies, and batch adsorber design.

The retention profile of methylene blue from aqueous solutions onto the solid adsorbent date pits has been investigated in a batch system. The characterization and adsorption efficiency for methylene blue was evaluated using date pits. Fourier Transform Infra-Red, Scanning Electron Microscope, Brunauer-Emmett-Teller analysis were performed to determine the characteristics of the material. The effect of contact time, initial dye concentration, adsorbent dosage, temperature, and solution pH were investigated. The adsorption was found to increase with increasing time, decreasing concentration of dye, decreasing temperature and increasing dosage up to equilibrium values which was 20 min, 25°C, and 0.1 g adsorbent, respectively. The adsorption was favorable at high and low pH (pH 3, pH 7). The adsorption equilibrium data were best fitted by Freundlich isotherm. The adsorption kinetics was found to follow the pseudo second order kinetic model. Thermodynamic parameters such as free energy, enthalpy, and entropy were calculated and found to be -4.6 kJ/mole, -7.9 kJ/mole, and -11.8 kJ/mole, respectively. The thermodynamic parameters of the uptake of methylene blue onto the date pits indicated that, the process is exothermic and proceeds spontaneously at low temperature. A single stage batch adsorber was designed for adsorption of methylene blue by Date Pits based on optimum isotherm.

Public health risk management case concerning the city of Isfahan according to a hypothetical release of HF from a chemical plant.

Accidents have happened in the chemical industries all over the world with serious consequences for the adjacent heavily populated areas. In this study, the impact of the probable hypothetical event, releasing considerable amounts of hydrogen fluoride (HF) as a strong irritant into the atmosphere over the city of Isfahan from a strategic chemical plant, was simulated by computational fluid dynamics (CFD). In this model, the meteorological parameters were integrated into time and space, and dispersion of the pollutants was estimated based on a probable accidental release of HF. According to the hypothetical results of the simulation model in this study, HF clouds reached Isfahan in 20 min and exposed 80% of the general public to HF concentration in the range of 0-34 ppm. Then, they dissipated 240 min after the time of the incident. Supposing the uniform population density within the proximity of the city of Isfahan with the population of 1.75 million, 5% of the population (87,500 people) could be exposed for a few minutes to a HF concentration as high as 34 ppm. This concentration is higher than a very hazardous concentration described as the Immediate Danger to Life and Health (30 ppm). This hypothetical risk evaluation of environmental exposure to HF with the potential of health risks was very instrumental for the general public of Isfahan in terms of risk management. Similar studies based on probable accidental scenarios along with the application of a simulation model for computation of dispersed pollutants are recommended for risk evaluation and management of cities in the developing countries with a fast pace of urbanization around the industrial sites.