144 research outputs found

    Venturi nozzles for desalination brine discharges

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    Seawater desalination is a reliable way to confront the growing challenges of freshwater demands in the world. Brine is the primary by-product of this process and needs to be carefully managed and discharged back into the sea. In coastal desalination plants, the use of submerged outfall as a pipeline laying on the ocean floor is a popular strategy to minimize the environmental impacts of brine discharge. The Venturi nozzle has been proposed as a more efficient method for dispersing brine into the ocean. However, it requires a high exit velocity, which poses limitations for steep nozzle angles in shallow waters. This study aims to investigate the benefits of a lower range of exit velocities in the Venturi nozzles. The 60â—¦ inclined dense jet from a Venturi nozzle was explored, numerically and experimentally, and the results were compared to those of a simple dense jet. Comparisons showed that the Venturi nozzle decreases the flow path and diminishes flow dilution at the critical points. However, this reduction can be compensated by increasing the discharge Froude number to reach the same trajectory as a simple jet. It is important to note that this compensation is intricately linked to the discharge velocity, and it makes the use of Venturi nozzles for brine discharge a challenging proposition in both deep and shallow waters

    Evaluating the development of life and progress of heavy vehicles based on Analytical Hierarchy Process (AHP) in main subsystems

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    The development of automotive products considering product lifecycle is considered as one of the automotive strategic key issues. In this article, Analytical Hierarchy Process (AHP) is used to evaluate the lifetime of heavy vehicles. To do this research, subsystems of weighted Titan heavy vehicle and the position of desired vehicle compared to other vehicles in the various subsystems and in general by the technical standards, new technologies and aesthetic appearance is evaluated. Finally, the curve of progress and technology life of Titan vehicle is provided. The results show that technical standards in automotive technology growth curve has the greatest impact in comparison with other properties. About Titan vehicle according to the technology lifecycle should be considered this issue that the technology of this vehicle because spending their maturity era is in decline. Regarding the investigation of new technologies, we have to think to make changes in vehicle technology or finding alternative technology. According to the first priority, criteria and the weight of analytic hierarchy process, the technical criteria, first the action should be done in technical improvements of the vehicle, and also considering that the sub-criteria of engine performance assigned the highest weight to itself, most of the studies should be placed in order to improve Titan automotive technology in terms of vehicle performance.Keywords: lifecycle, lifecycle of technology, heavy vehicles, subsystems, Analytical Hierarchy Process (AHP

    Simultaneous Localization and Mapping and Tag-Based Navigation for Unmanned Aerial Vehicles

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    This paper presents navigation techniques for an Unmanned Aerial Vehicle (UAV) in a virtual simulation of an indoor environment using Simultaneous Localization and Mapping (SLAM) and April Tag markers to reach a target destination. In many cases, UAVs can access locations that are inaccessible to people or regular vehicles in indoor environments, making them valuable for surveillance purposes. This study employs the Robot Operating System (ROS) to simulate SLAM techniques using LIDAR and GMapping packages for UAV navigation in two different environments. In the Tag-based simulation, the input topic for April Tag in ROS is camera images, and the calibration of position with a tag is done through assigning a message to each ID and its marker image. On the other hand, navigation in SLAM was achieved using a global and local planner algorithm. For localization, an Adaptive Monte-Carlo Localization (AMCL) technique has been used to identify factors contributing to inconsistent mapping results, such as heavy computational load, grid mapping accuracy, and inadequate UAV localization. Furthermore, this study analyzed the April Tag-based navigation algorithm, which showed satisfactory outcomes due to its lighter computing requirements. It can be ascertained that by using ROS packages, the simulation of SLAM and Tag-based UAV navigation inside a building can be achieved. &nbsp

    Simultaneous Localization and Mapping and Tag-Based Navigation for Unmanned Aerial Vehicles

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    This paper presents navigation techniques for an Unmanned Aerial Vehicle (UAV) in a virtual simulation of an indoor environment using Simultaneous Localization and Mapping (SLAM) and April Tag markers to reach a target destination. In many cases, UAVs can access locations that are inaccessible to people or regular vehicles in indoor environments, making them valuable for surveillance purposes. This study employs the Robot Operating System (ROS) to simulate SLAM techniques using LIDAR and GMapping packages for UAV navigation in two different environments. In the Tag-based simulation, the input topic for April Tag in ROS is camera images, and the calibration of position with a tag is done through assigning a message to each ID and its marker image. On the other hand, navigation in SLAM was achieved using a global and local planner algorithm. For localization, an Adaptive Monte-Carlo Localization (AMCL) technique has been used to identify factors contributing to inconsistent mapping results, such as heavy computational load, grid mapping accuracy, and inadequate UAV localization. Furthermore, this study analyzed the April Tag-based navigation algorithm, which showed satisfactory outcomes due to its lighter computing requirements. It can be ascertained that by using ROS packages, the simulation of SLAM and Tag-based UAV navigation inside a building can be achieved. &nbsp

    Correlation between high-risk pregnancy and developmental delay in children aged 4-60 months

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    Background: The future development of children is considered more than ever now due to the advances in medical knowledge and thus the increase in survival rates of high-risk infants. This study investigated the correlation between high-risk pregnancy and developmental delay in children aged 4- 60 months.Methods: This descriptive study was conducted on 401 mothers and their children (460 months) who visited health service centers affiliated to Isfahan University of Medical Sciences, Iran, in 2011. Sampling was carried out in several stages, and the Ages and Stage Questionnaire was completed by the participants. Data were analyzed with SPSS 18 software and independent t-test; Mann-Whitney and logistic-regression tests were used.Results: The average age of children in the low-risk pregnancy group was 22916 months, and that in the highrisk pregnancy group was 18.9914.8 months. The majority of children were female (53.1%). The prevalence ofhigh-risk pregnancies was 80.5%, and the prevalence of developmental delay was 18.7%. Multiple pregnancies, low birth weight, habitual abortions, maternal medical disorders in pregnancy, and gestational diabetes had significant correlations with developmental delay in children (PB0.04). In the logistic model, male gender, low birth weight, family marriage, and maternal medical disorders during pregnancy showed significant correlations with developmental delay in children (PB0.05). Additionally, abnormal body mass index (BMI) and social and economic status showed probability values close to the significance level (P0.05), whereas other high-risk pregnancy variables had no correlation with developmental delay in children. A correlation between high-risk pregnancy and developmental delay (P0.002) and fine motor delay was observed (P 0.02), but no correlation was observed between high-risk pregnancy and other developmental domains.Conclusion: This study showed that some high-risk pregnancy variables had a significant correlation with developmental delay. Moreover, a significant correlation was observed between high-risk pregnancy and fine motor developmental delay.Keywords: high-risk pregnancy; development delay; Ages and Stages Questionnair

    Gastric Perforation, a Rare Consequence of Unintentional Esophageal Intubation

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    Accidental esophageal intubation is a preventable human error that complicates airway management and continues to occur despite advances in medical devices. Perforation of the stomach has been associated with esophageal intubation in several case reports.This report presents a case of an elderly woman suspected of having COVID-19-related pneumonia. She was intubated due to respiratory dysfunction. In the initial few minutes, the patient became desaturated, leading to a second intubation. An hour later, the patient’s abdomen was distended, and the chest computed tomography (CT) showed a massive pneumoperitoneum. During laparotomy, a 6 cm long rupture was found in the lesser curvature, which was attributed to accidental esophageal intubation. To avoid such a fatal condition, it is imperative for physicians to ensure the correct positioning of the endotracheal tube. To achieve this goal, further investigation into readily available and highl y sensitive techniques is recommended

    Nourodevelopmental follow-up in high-risk infants: Review article

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    Growing and developing are influenced by genetic, social and environmental factors and it's most important and initial phase step is formed of the early life of the fetus and infant. According to the world health organization, the incidence of preterm birth and low birth weight are increasing in most countries that most of it related to developing countries. Low birth weight (LBW) and preterm birth are one the most important causes of death in the world and therefore are considered as one of the major health problems that can affect growing and developing so that it can threaten public health. Advances in medical technology in recent decades at intensive care unit, increased survival of premature infants and high-risk specialist care is needed, but failed, to reduce the complications of premature birth but it couldn’t reduce complications of preterm birth. There is also an increased recognition of the potential disconnect between perinatal outcomes and long-term outcomes. The administration of oxygen and postnatal steroids are prime examples of interventions that may have immediate positive effects but negative long-term effects. Many premature babies will be encounter with mobility problems, cognitive, neurosensory impairments, cerebral palsy, cognitive and language delays, neuromotor developmental delay, blindness and hearing loss, behavioral and psychosocial disorders, learning difficulties and dysfunction in scholastic performances in the future. These disadvantages appear to persist into adulthood and therefore have broad implications for society. Without a doubt, one of the tragedies of the world is people with physical or mental damage caused by premature birth, many of these disorders are not early diagnosed and the prediction of long term complications of infants discharged from the NICU is difficult. Although nourodevelopmental follow-up of these babies is a necessary part of the neonatal assessment but there is no standard process for it. The present review article aims to introduce the care process and tools that is used for following-up these babies, also introduces the application of screening tools for neuro-developmental care

    Antiapoptotic and antioxidative effects of cerium oxide nanoparticles on the testicular tissues of streptozotocin-induced diabetic rats: An experimental study

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    Background: Cerium dioxide nanoparticles (CNPs) due to the antidiabetic and antioxidant activities are proposed for the treatment of oxidative stress-associated diseases. Objective: To examine the impact of CNPs on hyperglycemia-induced apoptosis and oxidative stress in the testis of diabetic rats. Materials and Methods: Twenty-four male rats were divided into four groups (n = 6/each) as diabetic rats, CNPs group, diabetic + CNPs rats, and controls. The control group was fed only mouse food and water. Rats became diabetic through receiving streptozotocin (STZ) 60 mg/kg. CNPs were given to the rats at a dose of 30 mg/kg daily for 2 wk. Malondialdehyde and total thiol group (TTG) levels were measured using spectrofluorometer. Expression of b-cell lymphoma protein 2-associated X protein (BAX) and b-cell lymphoma protein 2 (Bcl-2) were investigated using quantitative real-time polymerase chain reaction. Western blot analysis was used to examine caspase 3 protein levels. Results: The content of malondialdehyde significantly increased in the STZ-diabetic rats, while TTG levels demonstrated a remarkable decrease. Caspase-3, BAX, and BAX/Bcl-2 mRNA ratio raised significantly in the STZ-diabetic rats. On the other hand, Bcl-2 mRNA levels reduced in the testis of diabetic rats (p = 0.006). Intervention with CNPs caused a substantial increase in the TTG levels, while the malondialdehyde contents, caspase-3, BAX levels, as well as BAX/Bcl-2 mRNA ratio were considerably decreased following CNPs treatment. Administration of CNPs increased mRNA levels of Bcl-2 (p < 0.0001). Conclusion: CNPs treatment attenuates testicular apoptosis and oxidative stress induced by diabetes. This nanoparticle might be suggested for the treatment of diabetes-associated reproductive disorders. Key words: Apoptosis, Nanoceria, Diabetes, Oxidative stress, Testis

    An Online Calculating Model for Leachate Production in Mazandaran’s Waste Landfills; (Case Study: Babol Municipal Waste Landfill)

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    Leachate production and management is a challenging environmental issue in municipal landfills and depots in Iran. Leachate contains toxic materials, heavy metals, and organic and microbial pollutants on a significant scale. Its uncontrolled entrance into the surface, groundwater, and soils can also substantially inverse impacts on human health and natural habitats. In Mazandaran province, during the last decades, depots and landfilling of municipal and industrial waste have led to environmental degradation in its eco-sensitive natural zones and brought a series of health, social, and security challenges to the region. Due to the region's high precipitation rate and landfills with no cover, these places practically convert into an extensive resource for leachate production. To diminish the environmental impacts, a lot of work has been done in recent years to develop a sort of leakage gathering system and treatment plants in these landfills, based primarily on an overall estimation. In this study, a calculating computer model has been developed for leakage production based on regional climate conditions and the characteristics of municipal waste. This model is different from the HELP model, which is commonly used for sanitary landfills and is specifically developed for the waste depots of the Mazandaran province. In this model, hydrological methods, which are based on the water balance in the landfill sites, were used for the calculation. The developed model was uploaded as an online service for public use. By referring to the internet address provided, the developed model in the landfill part and the leachate section, the amount of produced leachate for the landfill site of Mazandaran province can be calculated. Also, the leachate volume of the Babol Anjilsi landfill has been calculated as a case study. As a result of this study, the lowest and highest amount of the production leachate for hot and dry months of the year (June and July) and for wet and rainy months (October) was about 63.39 and 260.07 cubic meters per day, respectively
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