Search results for: gliding arc discharge

Authors: Juliana A. Galhardi, Daniel M. Bonotto

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Coal is an important non-renewable energy source of and can be associated with radioactive elements. In Figueira city, Paraná state, Brazil, it was recorded high uranium activity near the coal mine that supplies a local thermoelectric power plant. In this context, the radon activity (Rn-222, produced by the Ra-226 decay in the U-238 natural series) was evaluated in groundwater, river water and effluents produced from the acid mine drainage in the coal reject dumps. The samples were collected in August 2013 and in February 2014 and analyzed at LABIDRO (Laboratory of Isotope and Hydrochemistry), UNESP, Rio Claro city, Brazil, using an alpha spectrometer (AlphaGuard) adjusted to evaluate the mean radon activity concentration in five cycles of 10 minutes. No radon activity concentration above 100 Bq.L-1, which was a previous critic value established by the World Health Organization. The average radon activity concentration in groundwater was higher than in surface water and in effluent samples, possibly due to the accumulation of uranium and radium in the aquifer layers that favors the radon trapping. The lower value in the river waters can indicate dilution and the intermediate value in the effluents may indicate radon absorption in the coal particles of the reject dumps. The results also indicate that the radon activities in the effluents increase with the sample acidification, possibly due to the higher radium leaching and the subsequent radon transport to the drainage flow. The water samples of Laranjinha River and Ribeirão das Pedras stream, which, respectively, supply Figueira city and receive the mining effluent, exhibited higher pH values upstream the mine, reflecting the acid mine drainage discharge. The radionuclides transport indicates the importance of monitoring their activity concentration in natural waters due to the risks that the radioactivity can represent to human health.

Keywords: radon, radium, acid mine drainage, coal

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Authors: Eki Farlen, Akas

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Condition assessment of oil-paper-insulated power transformers, particularly of water content, is becoming increasingly important for aged transformers. As insulation ages, it can produce water, which reduces its dielectric strength, accelerates the cellulose ageing process, and causes gas bubbles to form at high temperatures. This paper mainly assesses the life condition of oil-paper insulation system of Inter Bus Transformer (IBT) 30 MVA, 150/30 kV in PT PLN-Substation Jelok that has been operating for 41 years, since 1974. Valuable information about the condition of high voltage insulation may be obtained by measuring its dielectric response. This paper describes in detail the interpretation of Dielectric Response Analysis (DIRANA) measurements and the test result compared to other insulation tests to get deep information for diagnostic, such as Tan delta test, oil characteristic test and Dissolve Gas Analysis (DGA) test. This paper mainly discusses the parameter relationship between moisture content, water content, acidity, oil conductivity and dissipation factor. The result and analysis show that IBT 30 MVA Jelok phase U and W had just been ageing due to high acidity level (>0.2 mgKOH/g) which cause high moisture in cellulose/paper (%) are in wet category about 4.7% and 5% and water content in oil (ppm) about 3.13 ppm and 3.33 ppm at temperature 20°C. High acidity level can make oxidation process and produce water in paper and particle which can decrease the value of Interfacial Tension (IFT) below 22 mN/m (poor category) for both phase U and W. Even if paper insulation of transformer are in wet condition, dissipation factor and capacitance at the same frequency (50 Hz) from both measurement DIRANA test and Tangent delta test give the same result (almost), the results are 0.69% and 0.71% (<1%), it may be acceptable and should not be investigated. The DGA results show that TDCG are in level one (1) condition and there are no found a Key Gases, it means that transformers had no failure during operation like arching, partial discharge and thermal in oil or cellulose.

Keywords: diagnostic, inter-bus transformer, oil-paper insulation, moisture, dissipation factor

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Authors: Mohd Amran, Chan Yi Jing, Chong Chien Hwa

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Production of biogas from POME requires anaerobic digestion (AD), thus, anaerobic digester performance in biogas plants is crucial. As POME from different sources have varying characteristics due to different process flows in mills, there is no ideal treatment parameters for POME. Hence, different treatment plants alter different parameters in anaerobic digestion to achieve desired biogas production levels and to meet POME waste discharge limits. The objective of this study is to evaluate the performance of mesophilic anaerobic digestion in four different biogas plants in Malaysia. Aspects of POME pre-treatment efficiency, analysis of treated POME and AD’s bottom sludge characteristics, including several parameters like chemical oxygen demand (COD), biological oxygen demand (BOD), total solid (TS) removal in the effluent, pH and temperature changes, total biogas produced, the composition of biogas including methane (CH₄), carbon dioxide (CO₂), hydrogen sulfide (H₂S) and oxygen (O₂) were investigated. The effect of organic loading rate (OLR) and hydraulic retention time (HRT) on anaerobic digester performance is also evaluated. In pre-treatment, it is observed that BGP B has the lowest average outlet temperature of 40.41°C. All BGP shows a high-temperature fluctuation (36 to 49 0C) and good pH readings (minimum 6.7), leaving the pre-treatment facility before entering the AD.COD removal of POME is considered good, with an average of 78% and maximum removal of 85%. BGP C has the lowest average COD and TS content in treated POME, 13,313 mg/L, and 12,048 mg/L, respectively. However, it is observed that the treated POME leaving all ADs, still contains high-quality organic substances (COD between 12,000 to 19,000 mg/L) that might be able to digest further to produce more biogas. The biogas produced in all four BGPs varies due to different COD loads. BGP B has the highest amount of biogas produced, 378,874.7 Nm³/month, while BGP D has the lowest biogas production of 272,378.5 Nm³/month. Furthermore, the composition of biogas produced in all plants is well within literature values (CH4 between 55 to 65% and CO₂ between 32 to 36%).

Keywords: palm oil mill effluent, in-ground lagoon anaerobic digester, anaerobic digestion, biogas

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Authors: F. Christie, M. Staber

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Malnutrition is a predictor of poor clinical outcome in the elderly. Up to 60% of hip fracture patients are clinically malnourished on admission. This study assessed the perioperative nutritional state of patients admitted with a proximal femoral fracture and examined if adequate nutritional support was achieved. Methods: Prospective, the observational audit of 30 patients, admitted with a proximal femoral fracture, over a one-month period. We recorded: patient demographics; surgical delay; nutritional state on admission; documentation of Malnutrition Universal Screening Tool (MUST) score; dietician input and daily calorie intake through food charts. The nutritional state was re-assessed weekly and at discharge. The outcome was measured by the length of hospital stay and thirty-day mortality. Results: Mean age 87, M:F 1:2 and all patients were ASA three or four. Five patients (17%) had a prolonged ( >24 hours) fasting period. All patients had a MUST score completed on admission, 27% were underweight and 30% were high risk for malnutrition. Twenty-six patients (87%) were appropriately assessed for dietician referral. Thirteen patients had food charts; on average, hospital meals provided 1500kcal daily. No patient achieved > 75% of the provided calories with 69% of patients achieving 50% or less. Only three patients were started on nutritional supplements. Twenty-three patients (77%) lost weight, averaging 6% weight loss during admission. Mean length of stay (LOS) was 23 days and 30-day mortality 9%. Four patients (13%) gained weight, their mean LOS was 17 days and 30-day mortality 0%. Discussion: Malnutrition in the elderly originates in the community. Following major trauma it’s difficult to reverse nutritional deficits in hospitals. It’s therefore concerning that no high-risk patient achieved their recommended calorie intake. Perioperative optimisation needs to include early nutritional intervention, early anaesthetic review and adjusted anaesthetic techniques to support feeding.

Keywords: trauma, nutrition, neck of femur fracture

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Authors: Yasir M. Alyazichi, Brian G. Jones, Errol McLean, Hamd N. Altalyan, Ali K. M. Al-Nasrawi

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The main purpose of this study is to assess the sediment quality and potential ecological risk in marine sediments in Gymea Bay located in south Sydney, Australia. A total of 32 surface sediment samples were collected from the bay. Current track trajectories and velocities have also been measured in the bay. The resultant trace elements were compared with the adverse biological effect values Effect Range Low (ERL) and Effect Range Median (ERM) classifications. The results indicate that the average values of chromium, arsenic, copper, zinc, and lead in surface sediments all reveal low pollution levels and are below ERL and ERM values. The highest concentrations of trace elements were found close to discharge points and in the inner bay, and were linked with high percentages of clay minerals, pyrite and organic matter, which can play a significant role in trapping and accumulating these elements. The lowest concentrations of trace elements were found to be on the shoreline of the bay, which contained high percentages of sand fractions. It is postulated that the fine particles and trace elements are disturbed by currents and tides, then transported and deposited in deeper areas. The current track velocities recorded in Gymea Bay had the capability to transport fine particles and trace element pollution within the bay. As a result, hydrodynamic measurements were able to provide useful information and to help explain the distribution of sedimentary particles and geochemical properties. This may lead to knowledge transfer to other bay systems, including those in remote areas. These activities can be conducted at a low cost, and are therefore also transferrable to developing countries. The advent of portable instruments to measure trace elements in the field has also contributed to the development of these lower cost and easily applied methodologies available for use in remote locations and low-cost economies.

Keywords: current track velocities, gymea bay, surface sediments, trace elements

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Authors: Simona Capossela, Ramona Schaniel, Singer Franziska, Aquino Fournier Catharine, Daniel Stekhoven, Jivko Stoyanov

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A spinal cord injury (SCI) is a traumatic life event that often results in ageing associated health conditions such as muscle mass decline, adipose tissue increase, decline in immune function, frailty, systemic chronic inflammation, and psychological distress and depression. Psychological, oxidative, and metabolic stressors may facilitate accelerated ageing in the SCI population with reduced life expectancy. Research designs using biomarkers of aging and stress are needed to elucidate the role of psychological distress in accelerated aging. The aim of this project is a feasibility pilot study to observe changes in stress biomarkers and correlate them with aging markers in SCI patients during their first rehabilitation (longitudinal cohort study). Biological samples were collected in the SwiSCI (Swiss Spinal Cord Injury Cohort Study) Biobank in Nottwil at 4 weeks±12 days after the injury (T1) and at the end of the first rehabilitation (discharge, T4). The "distress thermometer" is used as a selfassessment tool for psychological distress. Stress biomarkers, as cortisol and protein carbonyl content (PCC), and markers of cellular aging, such as telomere lengths, will be measured. 2 Preliminary results showed that SCI patients (N= 129) are still generally distressed at end of rehabilitation, however we found a statistically significant (p< 0.001) median decrease in distress from 6 (T1) to 5 (T4) during the rehabilitation. In addition, an explorative transcriptomics will be conducted on N=50 SCI patients to compare groups of persons with SCI who have different trajectories of selfreported distress at the beginning and end of the first rehabilitation after the trauma. We identified 4 groups: very high chronic stress (stress thermometer values above 7 at T1 and T4; n=14); transient stress (high to low; n=14), low stress (values below 5 at T1 and T4; n=14), increasing stress (low to high; n=8). The study will attempt to identify and address issues that may occur in relation to the design and conceptualization of future study on stress and aging in the SCI population.

Keywords: stress, aging, spinal cord injury, biomarkers

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Authors: Nur-E-Jannat Tinu

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Water is absolutely vital not only for the survival of human beings but also for plants, animals, and all other living organisms. Water bodies, such as lakes, rivers, ponds, and estuaries, are the source of water supply in domestic, industrial, agriculture, and aquaculture purposes. The Buriganga River flows through the south and west of Dhaka city. The water quality of this river has become a matter of concern due to anthropogenic intervention of vital pollutants such as industrial effluents, urban sewage, and solid wastes in this area. Buriganga River is at risk to contamination from untreated municipal wastes, industrial discharges, runoff from organic and inorganic fertilizers, pesticides, insecticides, and oil emission around the river. The residential and commercial establishments along the river discharge wastewater either directly into the river or through drains and canals into the river. However, several regulatory measures and policies have been enforced by the Government to protect the river Buriganga from pollution, in most cases to no affect. Water quality assessment reveals that the water is also not appropriate for irrigation purposes. The physical parameters (pH, TDS, EC, Temperature, DO, COD, BOD) indicated that the water is too poor to be useable for agricultural, drinking, or other purposes. Chemical concentrations showed significant seasonal variations with high-level concentrations during the monsoon season, presumably due to extreme seasonal surface runoff. A comparative study of Electrical Conductivity (EC) and Total Dissolved Solids (TDS) indicated a considerable increase over the last five years A change in trend was observed from 2020 June-July, probably due to monsoon and post-monsoon. EC values decreased from 775 to 665 mmho/cm during this period. DO increased significantly from the mid-post-monsoon months to the early monsoon period. The pH value of river water is strongly alkaline, ranging between 6.5 and 7.79. This indicates that ecological organic compounds cause the water to become alkaline after the monsoon and monsoon seasons. As the water pollution level is very high, an effective remediation and pollution control plan should be considered.

Keywords: precipitation, spatial distribution, effluent, remediation

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Authors: Hacer Sule Gonul, Vedat Uyak

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Intensive use of pesticides in agricultural activity causes mixing of these compounds into water sources with surface flow. Especially after the 1970s, a number of limitations imposed on the use of chlorinated pesticides that have a carcinogenic risk potential and regulatory limit have been established. These chlorinated pesticides discharge to water resources, transport in the water and land environment and accumulation in the human body through the food chain raises serious health concerns. Carbon nanotubes (CNTs) have attracted considerable attention from on all because of their excellent mechanical, electrical, and environmental characteristics. Due to CNT particles' high degree of hydrophobic surfaces, these nanoparticles play critical role in the removal of water contaminants of natural organic matters, pesticides and phenolic compounds in water sources. Health concerns associated with chlorinated pesticides requires the removal of such contaminants from aquatic environment. Although the use of aldrin and atrazine was restricted in our country, repatriation of illegal entry and widespread use of such chemicals in agricultural areas cause increases for the concentration of these chemicals in the water supply. In this study, the compounds of chlorinated pesticides such as aldrin and atrazine compounds would be tried to eliminate from drinking water with carbon nanotube adsorption method. Within this study, 2 different types of CNT would be used including single-wall (SWCNT) and multi-wall (MWCNT) carbon nanotubes. Adsorption isotherms within the scope of work, the parameters affecting the adsorption of chlorinated pesticides in water are considered as pH, contact time, CNT type, CNT dose and initial concentration of pesticides. As a result, under conditions of neutral pH conditions with MWCNT respectively for atrazine and aldrin obtained adsorption capacity of determined as 2.24 µg/mg ve 3.84 µg/mg. On the other hand, the determined adsorption capacity rates for SWCNT for aldrin and atrazine has identified as 3.91 µg/mg ve 3.92 µg/mg. After all, each type of pesticide that provides superior performance in relieving SWCNT particles has emerged.

Keywords: pesticide, drinking water, carbon nanotube, adsorption

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Authors: L. Shafiq, A. Rigby

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All polyethylene processes are highly exothermic, and the safe removal of the heat of reaction is a fundamental issue in the process design. In slurry and gas processes, the velocity of the polymer particles in the reactor and external coolers can be very high, and under certain conditions, this can lead to static charging of these particles. Such static charged polymer particles may start building up on the reactor wall, limiting heat transfer, and ultimately leading to severe reactor fouling and forced reactor shut down. Statsafe™ is an FDA approved anti-fouling additive currently used around the world for polyolefin production as an anti-fouling additive. The unique polymer chemistry aids static discharge, which prevents the build-up of charged polyolefin particles, which could lead to fouling. Statsafe™ is being used and trailed in gas, slurry, and a combination of these technologies around the world. We will share data to demonstrate how the use of Statsafe™ allows more stable operation at higher solids level by eliminating static, which would otherwise prevent closer packing of particles in the hydrocarbon slurry. Because static charge generation depends also on the concentration of polymer particles in the slurry, the maximum slurry concentration can be higher when using Statsafe™, leading to higher production rates. The elimination of fouling also leads to less downtime. Special focus will be made on the impact anti-static additives have on catalyst performance within the polymerization process and how this has been measured. Lab-scale studies have investigated the effect on the activity of Ziegler Natta catalysts when anti-static additives are used at various concentrations in gas and slurry, polyethylene and polypropylene processes. An in-depth gas phase study investigated the effect of additives on the final polyethylene properties such as particle size, morphology, fines, bulk density, melt flow index, gradient density, and melting point.

Keywords: anti-static additives, catalyst performance, FDA approved anti-fouling additive, polymerisation

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Authors: Yusra Mahfooz, Saleha Mehmood

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With increase in industrialization and urbanization, water contaminating rivers through effluents laden with diverse chemicals in developing countries. The study was based on the waste water quality of the four drains (Outfall, Gulshan -e- Ravi, Hudiara, and Babu Sabu) which enter into river Ravi in Lahore, Pakistan. Different pollution parameters were analyzed including pH, DO, BOD, COD, turbidity, EC, TSS, nitrates, phosphates, sulfates and fecal coliform. Approximately all the water parameters of drains were exceeded the permissible level of wastewater standards. In calculation of pollution load, Hudiara drains showed highest pollution load in terms of COD i.e. 429.86 tons/day while in Babu Sabu drain highest pollution load was calculated in terms of BOD i.e. 162.82 tons/day (due to industrial and sewage discharge in it). Lab scale treatment (oxidation ponds) was designed in order to treat the waste water of Babu Sabu drain, through combination of different algae species i.e. chaetomorphasutoria, sirogoniumsticticum and zygnema sp. Two different sizes of ponds (horizontal and vertical), and three different concentration of algal samples (25g/3L, 50g/3L, and 75g/3L) were selected. After 6 days of treatment, 80 to 97% removal efficiency was found in the pollution parameters. It was observed that in the vertical pond, maximum reduction achieved i.e. turbidity 62.12%, EC 79.3%, BOD 86.6%, COD 79.72%, FC 100%, nitrates 89.6%, sulphates 96.9% and phosphates 85.3%. While in the horizontal pond, the maximum reduction in pollutant parameters, turbidity 69.79%, EC 83%, BOD 88.5%, COD 83.01%, FC 100%, nitrates 89.8%, sulphates 97% and phosphates 86.3% was observed. Overall treatment showed that maximum reduction was carried out in 50g algae setup in the horizontal pond due to large surface area, after 6 days of treatment. Results concluded that algae-based treatment are most energy efficient, which can improve drains water quality in cost effective manners.

Keywords: oxidation pond, ravi pollution, river water quality, wastewater treatment

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Authors: Ahmed El Naggar, Homyan Saleh

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Dams are crucial for flood control, water supply, and the creation of hydroelectric power. Every dam has a water conveyance system, such as a spillway, providing the safe discharge of catastrophic floods when necessary. Spillway design has historically been investigated in laboratory research owing to the absence of suitable full-scale flow monitoring equipment and safety problems. Prototype measurements of aerated flows are urgently needed to quantify projected scale effects and provide missing validation data for design guidelines and numerical simulations. In this work, an image-based investigation of free-surface flows on a tiered spillway was undertaken at the laboratory (fixed camera installation) and prototype size (drone video) (drone footage) (drone footage). The drone videos were generated using data from citizen science. Analyses permitted the measurement of the free-surface aeration inception point, air-water surface velocities, fluctuations, and residual energy at the chute's downstream end from a remote site. The prototype observations offered full-scale proof of concept, while laboratory results were efficiently confirmed against invasive phase-detection probe data. This paper stresses the efficacy of image-based analyses at prototype spillways. It highlights how citizen science data may enable academics better understand real-world air-water flow dynamics and offers a framework for a small collection of long-missing prototype data.

Keywords: remote sensing, aerated flows, large dams, proof of concept, dam spillways, air-water flows, prototype operation, remote sensing, inception point, optical flow, turbulence, residual energy

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Authors: Gulnaz Erkomaishvili

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Introduction. One of the most important issues of state economic policy in the 21st century is the problem of environmental protection. The Georgian government considers the green economy as one of the most important means of sustainable economic development and takes the initiative to implement voluntary measures to promote sustainable development. In this context, it is important to promote the development of ecosystem services, clean production, environmental education and green jobs.The development of the green economy significantly reduces the inefficient use of natural resources, waste generation, emissions into the atmosphere and the discharge of untreated water into bodies of water.It is, therefore, an important instrument in the environmental orientation of sustainable development. Objectives.The aim of the paper is to analyze the current status of the green economy in Georgia and identify effective ways to improve the environmental, economic policy of sustainable development. Methodologies: This paper uses general and specific methods, in particular, analysis, synthesis, induction, deduction, scientific abstraction, comparative and statistical methods, as well as experts’ evaluation. bibliographic research of scientific works and reports of organizations was conducted; Publications of the National Statistics Office of Georgia are used to determine the regularity between analytical and statistical estimations. Also, theoretical and applied research of international organizations and scientist-economists are used. Contributions: The country should implement such an economic policy that ensures the transition to a green economy, in particular, revising water, air and waste laws, strengthening existing environmental management tools and introcing new tools (including economic tools). Perfecting the regulatory legal framework of the environmental impact assessment system, which includes the harmonization of Georgian legislation with the requirements of the European Union. To ensure the protection and rational use of Georgia's forests, emphasis should be placed on sustainable forestry, protection and restoration of forests.

Keywords: green economy, environmental protection, environmental protection economic policy, environmental protection policy challanges

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Authors: Sameer A. Pathan, Biswadev Mitra, Zain A. Bhutta, Isma Qureshi, Elle Spencer, Asmaa A. Hameed, Sana Nadeem, Ramsha Tahir, Shahzad Anjum, Peter A. Cameron

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Background: This study aimed to compare epidemiology, clinical presentations, management and outcomes of renal colic presentations in two major academic centers and discuss potential implications of these results for the applicability of current evidence in the management of renal colic. Methods: We undertook a retrospective cohort study of patients with renal colic who presented to the Hamad General Hospital Emergency Department (HGH-ED), Qatar, and The Alfred ED, Melbourne, Australia, during a period of one year from August 1, 2012, to July 3, 2013. Cases were identified using ICD-9-CM codes, and an electronic template was used to record the data on predefined clinical variables. Results: A total of 12,223 from the HGH-ED and 384 from The Alfred ED were identified as renal colic presentations during the study period. The rate of renal colic presentations at the HGH-ED was 27.9 per 1000 ED visits compared to 6.7 per 1000 ED visits at The Alfred ED. Patients presenting to the HGH-ED were significantly younger [34.9 years (29.0- 43.4) than The Alfred ED [48 years (37-60); P < 0.001]. The median stone size was larger in the HGH-ED group [6 (4-8) mm] versus The Alfred ED group [4 (3-6) mm, P < 0.001]. The intervention rate in the stone-positive population was significantly higher in the HGH-ED group as opposed to The Alfred ED group (38.7% versus 11.9%, p<0.001). At the time of discharge, The Alfred ED group received less analgesic prescriptions (55.8% versus 83.5%, P < 0.001) and more tamsulosin prescriptions (25.3% versus 11.7%, P < 0.001). Conclusions: Renal colic presentations to the HGH-ED, Qatar, were younger, with larger stone size, compared to The Alfred ED, whereas, medical expulsion therapy use was higher at the Alfred ED. Differences in epidemiology should be considered while tailoring strategies for effective management of patients with renal colic in the given setting.

Keywords: kidney stones, urolithiasis, nephrolithiasis, renal colic, epidemiology

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Authors: Masbubul Ishtiaque Ahmed

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Food chain contamination by heavy metals has become a critical issue in recent years because of their potential accumulation in bio systems through contaminated water, soil and irrigation water. Industrial discharge, fertilizers, contaminated irrigation water, fossil fuels, sewage sludge and municipality wastes are the major sources of heavy metal contamination in soils and subsequent uptake by crops. The main objectives of this project were to determine the levels of minerals, trace elements and heavy metals in major foods and beverages consumed by the poor and non-poor households of Dhaka city and assess the dietary risk exposure to heavy metal and trace metal contamination and potential health implications as well as recommendations for action. Heavy metals are naturally occurring elements that have a high atomic weight and a density of at least 5 times greater than that of water. Their multiple industrial, domestic, agricultural, medical and technological applications have led to their wide distribution in the environment; raising concerns over their potential effects on human health and the environment. Their toxicity depends on several factors including the dose, route of exposure, and chemical species, as well as the age, gender, genetics, and nutritional status of exposed individuals. Because of their high degree of toxicity, arsenic, cadmium, chromium, lead, and mercury rank among the priority metals that are of public health significance. These metallic elements are considered systemic toxicants that are known to induce multiple organ damage, even at lower levels of exposure. This review provides an analysis of their environmental occurrence, production and use, potential for human exposure, and molecular mechanisms of toxicity, and carcinogenicity.

Keywords: food chain, determine the levels of minerals, trace elements, heavy metals, production and use, human exposure, toxicity, carcinogenicity

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Authors: Umar Rehman, Holly Roy, K. T. Tsang, D. S. Jeyaretna, W Singleton, B. Fisher, P. A. Glew, J. Greig, Peter C. Whitfield

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Introduction: A brain abscess is a life-threatening condition, carrying significant mortality. It requires rapid identification and treatment. Management involves a combination of antibiotics and surgery. The aim of the current study was to identify common bacteria responsible for cerebral abscesses as well as the long term functional and neurological outcomes of patients following treatment in a retrospective series at a single UK neurosurgical centre. Methodology: We analysed patients that had received a diagnosis of 'cerebral abscess' or 'subdural empyema' between June 2002 and June 2018. This was done in the form of a retrospective review. The search resulted in a total of 180 patients; with 37 patients being excluded (spinal abscess, below 18 or non-abscess related admissions). Data were collected from medical case notes including information about demographics, comorbidities, immunosuppression, presentation, size/location of lesions, pathogens, treatment, and outcomes. Results: In total, we analysed 143 patients between the ages of 18-90. Focal neurological deficit and headaches were seen in 84% and 68% of patients respectively. 108 positive brain cultures were seen; with the largest proportion, 59.2% being gram-positive cocci, with strep intermedius being the most common pathogen identified in 13.9% of patients. Of the patients with positive blood cultures (n=11), 72.7% showed the same organism both in the blood and on the brain cultures. Long term outcomes (n=72) revealed that 48% of patients seizure-free without requiring anti-epileptics, 51.3% of patients had full recovery of their neurological symptoms. There was a mortality rate of 13.9% in the series. Conclusion: In conclusion, the largest bacterial cause of abscess within our population was due to gram-positive cocci. The majority of the patient demonstrated full neurological recovery with close to half of patients not requiring anti-epileptics following discharge.

Keywords: bacteria, cerebral abscess, long term outcome, neurological deficit

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Authors: Mariana Mangas, Yaroslava Martins, M. Suárez, Célia Santos, Ana Matos Pires

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Baixo Alentejo is a region of Portugal characterized by an aging population, geographic isolation, social deprivation and a lack of medical staff. It is one of the most problematic regions in regards to mental health, particularly due to the factors mentioned. The aim of this study is a presentation of liaison psychiatry in Hospital José Joaquim Fernandes; a sample of the work done, the current situation and future perspectives. The aim is to present a retrospective study of internal psychiatric emergencies from January 1st, 2016 to August 31st, 2016. Liaison psychiatry of Department of Psychiatry and Mental Health (Psychiatry Service) of ULSBA includes the following activities: internal psychiatry emergencies, HIV consultation (comprised in the general consultation) and liaison psychology (oncology and pain), consisting of a total of 111 internal psychiatry emergencies during the identified period. Gender distribution was uniform. The most prevalent age group was 71-80 years, and 66,6% of patients were 60 years old and over. The majority of the emergency observations was requested by hospital services of medicine (56,8%) and surgery (24,3%). The most frequent reasons for admission were: respiratory disease (18,0%); tumors (15.3%); other surgical and orthopedic pathology (14,5%) and stroke (11,7%). The most frequent psychiatric diagnoses were: neurotic and organic depression (24,3%); delirium (26,1%) and adjustment reaction (14,5%). Major psychiatric pathology (schizophrenia and affective disorders) was found in 10,8%. Antidepressive medication was prescribed in 37,8% patients; antipsychotics in 34,2%. In 9.9% of the cases, no psychotropic drug was prescribed, and 5,4% of patients received psychologic support. Regarding hospital discharge, 42,4% of patients were referred to the general practitioner or to the medical specialist; 22,5% to outpatient gerontopsychiatry; 17,1% to psychiatric outpatient and 14,4% deceased. A future perspective is to start liaison in areas of HIV and psycho oncology in multidisciplinary approach and to improve collaboration with colleagues of other specialties for refining psychiatric referrals.

Keywords: psychiatry, liaison, internal emergency, psychiatric referral

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Authors: Baba Hassane Ahmed Hisseini, Abdelkrim Bennabi, Rabah Hamzaoui, Lamis Makki, Gaetan Blanck

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Most of the clay soils are known as problematic soils due to their water content, which varies greatly over time. It is observed that they are used to be subject to shrinkage and swelling, thus causing a problem of stability on the structures of civil engineering construction work. They are often excavated and placed in a storage area giving rise to the opening of new quarries. This method has become obsolete today because to protect the environment, we are leading to think differently and opening the way to new research for the improvement of the performance of this type of clay soils to reuse them in the construction field. The solidification and stabilization technique is used to improve the properties of poor quality soils to transform them into materials with a suitable performance for a new use in the civil engineering field rather than to excavate them and store them in the discharge area. In our case, the polymerization method is used for bad clay soils classified as high plasticity soil class A4 according to the French standard NF P11-300, where classical treatment methods with cement or lime are not efficient. Our work concerns clay soil treatment study using raw materials as additives for solidification and stabilization. The geopolymers are synthesized by aluminosilicates materials like fly ash, metakaolin, or blast furnace slag and activated by alkaline solution based on sodium hydroxide (NaOH), sodium silicate (Na2SiO3) or a mixture of both of them. In this study, we present the mechanical properties of the soil clay (A4 type) evolution with geopolymerisation methods treatment. Various mix design of aluminosilicates materials and alkaline solutions were carried at different percentages and different curing times of 1, 7, and 28 days. The compressive strength of the untreated clayey soil could be increased from simple to triple. It is observed that the improvement of compressive strength is associated with a geopolymerization mechanism. The highest compressive strength was found with metakaolin at 28 days.

Keywords: treatment and valorization of clay-soil, solidification and stabilization, alkali-activation of co-product, geopolymerization

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Authors: Umashankar Morya, Somnath Basu

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Metalloids like arsenic are often present as contaminants in industrial effluents. Removal of the same is essential before the safe discharge of the wastewater into the environment. Otherwise, these pollutants tend to percolate into aquifers over a period of time and contaminate drinking water sources. Several adsorbents, including metal powders, carbon nanotubes and zeolites, are being used for this purpose, with varying degrees of success. However, most of these solutions are not only costly but also not always readily available. This restricts their use, especially among financially weaker communities. Slag generated globally from primary steelmaking operations exceeds 200 billion kg every year. Some of it is utilized for applications like road construction, filler in reinforced concrete, railway track ballast and recycled into iron ore agglomeration processes. However, these usually involve low-value addition, and a significant amount of the slag still ends up in a landfill. However, there is a strong possibility that the constituents in the steelmaking slag may immobilize metalloid contaminants present in wastewater through a combination of adsorption and precipitation of insoluble product(s). Preliminary experiments have already indicated that exposure to basic oxygen steelmaking slag does reduce pollutant concentration in wastewater. In addition, the slag is relatively inexpensive and available in large quantities and in several countries across the world. Investigations on the mechanism of interactions at the water-solid interfaces have been in progress for some time. However, at the same time, there are concerns about the possibility of leaching of metal ions from the slag particles in concentrations greater than what exists in the water bodies where the “treated” wastewater would eventually be discharged. The effect of such leached ions on the aquatic flora and fauna is yet uncertain. This has prompted the present investigation, which focuses on the leaching of metal ions from steelmaking slag particles in contact with wastewater, and the influence of these ions on the removal of contaminant species. Experiments were carried out to quantify the leaching behavior of different ionic species upon exposure of the slag particles to simulated wastewater, both with and without specific metalloid contaminants.

Keywords: slag, water, metalloid, heavy metal, wastewater

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Authors: Elisa K. Schoenell, Cristiano De Oliveira, Luiz R. H. Dos Santos, Alexandre Giacobbo, Andréa M. Bernardes, Marco A. S. Rodrigues

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Water is an indispensable natural resource, which must be preserved to human activities as well the ecosystems. However, the sewage discharge has been contaminating water resources. Conventional treatment, such as physicochemical treatment followed by biological processes, has not been efficient to the complete degradation of persistent organic compounds, such as medicines and hormones. Therefore, the use of advanced technologies to sewage treatment has become urgent and necessary. The aim of this study was to apply Reverse Osmosis (RO) on sewage tertiary treatment from a Waste Water Treatment Plant (WWTP) in south Brazil. It was collected 200 L of sewage pre-treated by wetland with aquatic macrophytes. The sewage was treated in a RO pilot plant, using a polyamide membrane BW30-4040 model (DOW FILMTEC), with 7.2 m² membrane area. In order to avoid damage to the equipment, this system contains a pleated polyester filter with 5 µm pore size. It was applied 8 bar until achieve 5 times of concentration, obtaining 80% of recovery of permeate, with 10 L.min-1 of concentrate flow rate. Samples of sewage pre-treated on WWTP, permeate and concentrate generated on RO was analyzed for physicochemical parameters and by gas chromatography (GC) to qualitative analysis of organic compounds. The results proved that the sewage treated on WWTP does not comply with the limit of phosphorus and nitrogen of Brazilian legislation. Besides this, it was found many organic compounds in this sewage, such as benzene, which is carcinogenic. Analyzing permeate results, it was verified that the RO as sewage tertiary treatment was efficient to remove of physicochemical parameters, achieving 100% of iron, copper, zinc and phosphorus removal, 98% of color removal, 91% of BOD and 62% of ammoniacal nitrogen. RO was capable of removing organic compounds, however, it was verified the presence of some organic compounds on de RO permeate, showing that RO did not have the capacity of removal all organic compounds of sewage. It has to be considered that permeate showed lower intensity of peaks in chromatogram in comparison to the sewage of WWTP. It is important to note that the concentrate generate on RO needs a treatment before its disposal in environment.

Keywords: organic compounds, reverse osmosis, sewage treatment, tertiary treatment

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Authors: Mirian Graciella Dalla Porta, Humberto Jorge José, Danielle de Bem Luiz, Regina de F. P. M.Moreira

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Similar to most processing industries, fish processing produces large volumes of wastewater, which contains especially organic contaminants, salts and oils dispersed therein. Different processes have been used for the treatment of fishery wastewaters, but the most commonly used are chemical coagulation and flotation. These techniques are well known but sometimes the characteristics of the treated effluent do not comply with legal standards for discharge. Electrocoagulation (EC) is an electrochemical process that can be used to treat wastewaters in terms of both organic matter and nutrient removal. The process is based on the use of sacrificial electrodes such as aluminum, iron or zinc, that are oxidized to produce metal ions that can be used to coagulate and react with organic matter and nutrients in the wastewater. While EC processes are effective to treatment of several types of wastewaters, applications have been limited due to the high energy demands and high current densities. Generally, the for EC process can be performed without additional chemicals or pre-treatment, but the costs should be reduced for EC processes to become more applicable. In this work, we studied the treatment of a real wastewater from fishmeal industry by electrocoagulation process. Removal efficiencies for chemical oxygen demand (COD), total organic carbon (TOC) turbidity, phosphorous and nitrogen concentration were determined as a function of the operating conditions, such as pH, current density and operating time. The optimum operating conditions were determined to be operating time of 10 minutes, current density 100 A.m-2, and initial pH 4.0. COD, TOC, phosphorous concentration, and turbidity removal efficiencies at the optimum operating conditions were higher than 90% for aluminum electrode. Operating costs at the optimum conditions were calculated as US$ 0.37/m3 (US$ 0.038/kg COD) for Al electrode. These results demonstrate that the EC process is a promising technology to remove nutrients from fishery wastewaters, as the process has both a high efficiency of nutrient removal, and low energy requirements.

Keywords: electrocoagulation, fish, food industry, wastewater

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Authors: Raj Chavan

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Currently, there are over 14,500 Water Resource Recovery Facilities (WRRFs) in the United States, with ~35% of them having some type of nutrient limits in place. These WRRFs account for about 1% of overall power demand and 2% of total greenhouse gas emissions (GHG) in the United States and contribute for 10 to 15% of the overall nutrient load to surface rivers in the United States. The evolution of densification technologies toward more compact and energy-efficient nutrient removal processes has been impacted by a number of factors. Existing facilities that require capacity expansion or biomass densification for higher treatability within the same footprint are being subjected to more stringent requirements relating to nutrient removal prior to surface water discharge. Densification of activated sludge has received recent widespread interest as a means for achieving process intensification and nutrient removal at WRRFs. At the core of the technology are the aerobic sludge granules where the biological processes occur. There is considerable interest in the prospect of producing granular sludge in continuous (or traditional) activated sludge processes (CAS) or densification of biomass by moving activated sludge flocs to a denser aggregate of biomass as a highly effective technique of intensification. This presentation will provide a fundamental understanding of densification by presenting insights and practical issues. The topics that will be discussed include methods used to generate and retain densified granules; the mechanisms that allow biological flocs to densify; the role that physical selectors play in the densification of biological flocs; some viable ways for managing biological flocs that have become densified; effects of physical selection design parameters on the retention of densified biological flocs and finally some operational solutions for customizing the flocs and granules required to meet performance and capacity targets. In addition, it will present some case studies where biological and physical parameters were used to generate aerobic granular sludge in the continuous flow system.

Keywords: densification, aerobic granular sludge, nutrient removal, intensification

Procedia PDF Downloads 131

Authors: Jeounghee Kim

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Objective: To describe the incidence of complication, according to the stage of Traumatic Spinal Cord Injury (TSCI) which was treated at Asan Medical Center (AMC), Korea. Hereafter, it should be developed in nursing management protocol of traumatic SCI. Methods. Retrospectively reviewed hospital records about the patients who were admitted AMC Patients with traumatic spinal cord injury until January 2005 and December 2016 were analyzed (n=97). AMC is a single institution of 2,700 beds where patients with trauma and severe trauma can be treated. Patients who were admitted to the emergency room due to spinal cord injury and who underwent intensive care unit, general ward, and rehabilitation ward. To identify long-term complications, we excluded patients who were operated on to other hospitals after surgery. Complications such as respiratory(pneumonia, atelectasis, pulmonary embolism, and others), cardiovascular (hypotension), urinary (autonomic dysreflexia, urinary tract infection (UTI), neurogenic bladder, and others), and skin systems (pressure ulcers) from the time of admission were examined through medical records and images. Results: SCI was graded according to ASIA scale. The initial grade was checked at admission. (grade A 55(56.7%), grade B 14(14.4)%, grade C 11(11.3%), grade D 15(15.5%), and grade E 2(2.1%). The grade was rechecked when the patient was discharged after treatment. (grade A 43(44.3%), grade B 15(15.5%), grade C 12(12.4%), grade D 21(21.6%), and grade E 6(6.2%). The most common complication after SCI was UTI 24cases (mean 36.5day), sore 24cases (40.5day), and Pneumonia which was 23 cases after 10days averagely. The other complications after SCI were neuropathic pain 19 cases, surgical site infection 4 cases. 53.6% of patient who had SCI were educated about intermittent catheterization at discharge from hospital. The mean hospital stay of all SCI patients was 61days. Conclusion: The Complications after traumatic SCI were developed at various stages from acute phase to chronic phase. Nurses need to understand fully the time-course of complication in traumatic SCI to provide evidence-based practice.

Keywords: spinal cord injury, complication, nursing, rehabilitation

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Authors: Fanniyah Anis, Bram Kilapong

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Myocardial reperfusion injury is defined as the cellular damage that results from a period of ischemia, followed by the reestablishment of the blood supply to the infarcted tissue. Ventricular tachycardia is one of the most commonly encountered reperfusion arrhythmia as one of the types of myocardial perfusion injury. Prompt and early treatment can reduce mortality, despite limited resources of the hospital in high risk patients with history of triple vessel disease. Case report, Male 53 years old has been diagnosed with NSTEMI with 3VD and comorbid disease of Hypertension and has undergone revascularization management with Percutaneous coronary intervention. Ventricular tachycardia leading to cardiac arrest occurred right after the stent was inserted. Resuscitation was performed for almost 2 hours until spontaneous circulation returned. Patient admitted in ICU with refractory cardiac shock despite using combination of ionotropic and vasopressor agents under standard non-invasive monitoring due to the limitation of the hospital. Angiography was performed again 5 hours later to exclude other possibilities of blockage of coronary arteries and conclude diagnosis of myocardial reperfusion injury. Patient continually managed with combination of antiplatelet agents and maintenance dose of anti-arrhythmia agents. The handling of the patient was to focus more on supportive and preventive from further deteriorating of the condition. Patient showed clinically improvement and regained consciousness within 24 hours. Patient was successfully discharged from ICU within 3 days without any neurological sequela and was discharge from hospital after 3 days observation in general ward. Limited Resource of hospital did not refrain the physician from attaining a good outcome for this myocardial reperfusion injury case and angiography alone can be used to confirm the diagnosis of myocardial reperfusion injury.

Keywords: limited resources hospital, myocardial reperfusion injury, prolonged resuscitation, refractory cardiogenic shock, reperfusion arrhythmia, revascularization, triple-vessel disease

Procedia PDF Downloads 273

Authors: Ana Maria Igual-Munoz, Juan Gilabert, Marta Garcia, Alfredo Quijano-Lopez

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Nowadays, several lithium-ion battery technologies are being commercialized. These chemistries present different properties that make them more suitable for different purposes. However, comparative studies showing the advantages and disadvantages of different chemistries are incomplete or scarce. Different non-destructive techniques are currently being employed to detect how ageing affects the active materials of lithium-ion batteries (LIBs). For instance, electrochemical impedance spectroscopy (EIS) is one of the most employed ones. This technique allows the user to identify the variations on the different resistances present in LIBs. On the other hand, differential voltage analysis (DVA) has shown to be a powerful technique to detect the processes affecting the different capacities present in LIBs. This technique shows variations in the state of health (SOH) and the capacities for one or both electrodes depending on their chemistry. Finally, incremental capacity analysis (ICA) is a widely known technique for being capable of detecting phase equilibria. It reminds of the commonly used cyclic voltamperometry, as it allows detecting some reactions taking place in the electrodes. In these studies, a set of ageing procedures have been applied to commercial batteries of different chemistries (NCA, NMC, and LFP). Afterwards, results of EIS, DVA, and ICA have been used to correlate them with the processes affecting each cell. Ciclability, overpotential, and temperature cycling studies envisage how the charge-discharge rates, cut-off voltage, and operation temperatures affect each chemistry. These studies will serve battery pack manufacturers, as for common battery users, as they will determine the different conditions affecting cells for each of the chemistry. Taking this into account, each cell could be adjusted to the final purpose of the battery application. Last but not least, all the degradation parameters observed are focused to be integrated into degradation models in the future. This fact will allow the implementation of the widely known digital twins to the degradation in LIBs.

Keywords: lithium ion batteries, non-destructive analysis, different chemistries, ante-mortem studies, ICA, DVA, EIS

Procedia PDF Downloads 96

Authors: Santimoy Khilari, Debabrata Pradhan

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Ever−increasing energy demand and growing energy crisis along with environmental issues emphasize the research on sustainable energy conversion and storage systems. Recently, supercapacitors or electrochemical capacitors emerge as a promising energy storage technology for future generation. The activity of supercapacitors generally depends on the efficiency of its electrode materials. So, the development of cost−effective efficient electrode materials for supercapacitors is one of the challenges to the scientific community. Transition metal oxides with spinel crystal structure receive much attention for different electrochemical applications in energy storage/conversion devices because of their improved performance as compared to simple oxides. In the present study, we have synthesized polypyrrole (PPy) supported manganese cobaltite nanorods (MnCo2O4 NRs) hybrid electrode material for supercapacitor application. The MnCo2O4 NRs were synthesized by a simple hydrothermal and calcination approach. The MnCo2O4 NRs/PPy hybrid was prepared by in situ impregnation of MnCo2O4 NRs during polymerization of pyrrole. The surface morphology and microstructure of as−synthesized samples was characterized by scanning electron microscopy and transmission electron microscopy, respectively. The crystallographic phase of MnCo2O4 NRs, PPy and hybrid was determined by X-ray diffraction. Electrochemical charge storage activity of MnCo2O4 NRs, PPy and MnCo2O4 NRs/PPy hybrid was evaluated from cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy. Significant improvement of specific capacitance was achieved in MnCo2O4 NRs/PPy hybrid as compared to the individual components. Furthermore, the mechanically mixed MnCo2O4 NRs, and PPy shows lower specific capacitance as compared to MnCo2O4 NRs/PPy hybrid suggesting the importance of in situ hybrid preparation. The stability of as prepared electrode materials was tested by cyclic charge-discharge measurement for 1000 cycles. Maximum 94% capacitance was retained with MnCo2O4 NRs/PPy hybrid electrode. This study suggests that MnCo2O4 NRs/PPy hybrid can be used as a low cost electrode material for charge storage in supercapacitors.

Keywords: supercapacitors, nanorods, spinel, MnCo2O4, polypyrrole

Procedia PDF Downloads 313

Authors: An-Yi Wang, Wei-Fong Kao, Shin-Han Tsai

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Introduction: Information as patient characteristics, resuscitation scene, resuscitation provider perspectives and families wish affects on resuscitation decision-making for out-of-hospital cardiac arrest (OHCA). There is no consistency consensus on how families and emergency physicians approach this decision. The main purpose of our study is to evaluate the characteristics of withholding resuscitation efforts arrival at the hospital. Methods: We retrospectively analyzed patients with OHCA without pre-hospital return-of-spontaneous circulation (ROSC) who was sent to our emergency department (ED) between January 2014 and December 2015. Baseline characteristics, pre-hospital course, and causes of the cardiopulmonary arrest among patients were compared. Results: In 2 years, total 155 arrest patients without pre-hospital ROSC was included. 33(21.3%) patients withhold the resuscitation efforts in ED with mean resuscitation duration 4.45 ± 7.04 minutes after ED arrival. In withholding group, the initial rhythm of arrests was all non-shockable. 9 of them received endotracheal intubation before decision-making. None of the patients in withhold resuscitation group survived to discharge. There was no significant difference among gender, underlying cardiovascular disease, malignancy, chronic renal disease, nor witness collapse between withhold and continue resuscitation groups. Univariate analysis showed there was lower percentage of bystander resuscitation (32.3% vs. 50.4%, p=0.071), and the lower percentage of transport via emergency medical service (EMS) (78.8% vs. 91.8%, p=0.054) in withholding group. Multivariate analysis showed old age (adjusted odds ratio=1.06, 95% C.I.=[1.02-1.11], p<0.05), with underlying respiratory insufficiency (adjusted odds ratio=12.16, 95% C.I.=[3.34-44.29], p<0.05), living at home compared with nursing home (adjusted odds ratio=37.75, 95% C.I.=[1.09-1110.70], p<0.05) were more likely to withhold resuscitation. Transport via EMS was more likely to continue resuscitation (adjusted odds ratio=0.11, 95% C.I.=[0.02-0.71], p<0.05). Conclusion: The decision-making for families and emergency physicians to withhold or continue resuscitation for out-of-hospital cardiac arrest is complex and multi-factorial. Continue resuscitation efforts in nursing home residents is high, and further study among this population is warranted.

Keywords: cardiopulmonary resuscitation, out-of-hospital cardiac arrest, termination resuscitation, withhold resuscitation

Procedia PDF Downloads 226

Authors: Xiaowei Zhang, Min Xu, Saeid Habibi, Fengjun Yan, Ryan Ahmed

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Recently, Electric Vehicles (EVs) have received extensive consideration since they offer a more sustainable and greener transportation alternative compared to fossil-fuel propelled vehicles. Lithium-Ion (Li-ion) batteries are increasingly being deployed in EVs because of their high energy density, high cell-level voltage, and low rate of self-discharge. Since Li-ion batteries represent the most expensive component in the EV powertrain, accurate monitoring and control strategies must be executed to ensure their prolonged lifespan. The Battery Management System (BMS) has to accurately estimate parameters such as the battery State-of-Charge (SOC), State-of-Health (SOH), and Remaining Useful Life (RUL). In order for the BMS to estimate these parameters, an accurate and control-oriented battery model has to work collaboratively with a robust state and parameter estimation strategy. Since battery physical parameters, such as the internal resistance and diffusion coefficient change depending on the battery state-of-life (SOL), the BMS has to be adaptive to accommodate for this change. In this paper, an extensive battery aging study has been conducted over 12-months period on 5.4 Ah, 3.7 V Lithium polymer cells. Instead of using fixed charging/discharging aging cycles at fixed C-rate, a set of real-world driving scenarios have been used to age the cells. The test has been interrupted every 5% capacity degradation by a set of reference performance tests to assess the battery degradation and track model parameters. As battery ages, the combined model parameters are optimized and tracked in an offline mode over the entire batteries lifespan. Based on the optimized model, a state and parameter estimation strategy based on the Extended Kalman Filter (EKF) and the relatively new Smooth Variable Structure Filter (SVSF) have been applied to estimate the SOC at various states of life.

Keywords: lithium-ion batteries, genetic algorithm optimization, battery aging test, parameter identification

Procedia PDF Downloads 238

Authors: Anubha Kaushik, Raman Preet

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Distillery wastewater in the form of spent wash is a complex and strong industrial effluent, with high load of organic pollutants that may deplete dissolved oxygen on being discharged into aquatic systems and contaminate groundwater by leaching of pollutants, while untreated spent wash disposed on land acidifies the soil. Stringent legislative measures have therefore been framed in different countries for discharge standards of distillery effluent. Utilising the organic pollutants present in various types of wastes as food by mixed microbial populations is emerging as an eco-friendly approach in the recent years, in which complex organic matter is converted into simpler forms, and simultaneously useful gases are produced as renewable and clean energy sources. In the present study, wastewater from a rice bran based distillery has been used as the substrate in a dark fermenter, and native microbial consortium from the digester sludge has been used as the inoculum to treat the wastewater and produce hydrogen. After optimising the operational conditions in batch reactors, sequential batch mode and continuous flow stirred tank reactors were used to study the best operational conditions for enhanced and sustained hydrogen production and removal of pollutants. Since the rate of hydrogen production by the microbial consortium during dark fermentation is influenced by concentration of organic matter, pH and temperature, these operational conditions were optimised in batch mode studies. Maximum hydrogen production rate (347.87ml/L/d) was attained in 32h dark fermentation while a good proportion of COD also got removed from the wastewater. Slightly acidic initial pH seemed to favor biohydrogen production. In continuous stirred tank reactor, high H₂ production from distillery wastewater was obtained from a relatively shorter substrate retention time (SRT) of 48h and a moderate organic loading rate (OLR) of 172 g/l/d COD.

Keywords: distillery wastewater, hydrogen, microbial consortium, organic pollution, sludge

Procedia PDF Downloads 240

Authors: Boor Singh Lalia, Yarjan Abdul Samad, Raed Hashaikeh

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Three different kinds of solid polymer electrolytes were prepared using polyethylene oxide (PEO) as a base polymer, networked cellulose (NC) as a physical support and LiClO4 as a conductive salt for the electrolytes. Networked cellulose, a modified form of cellulose, is a biodegradable and environmentally friendly additive which provides a strong fibrous networked support for structural stability of the electrolytes. Although the PEO/NC/LiClO4 electrolyte retains its structural integrity and mechanical properties at 100oC as compared to pristine PEO-based polymer electrolytes, it suffers from poor ionic conductivity. To improve the room temperature conductivity of the electrolyte, PEO is replaced by the polyethylene glycol (PEG) which is a liquid phase that provides high mobility for Li+ ions transport in the electrolyte. PEG/NC/LiClO4 shows improvement in ionic conductivity compared to PEO/NC/LiClO4 at room temperature, but it is brittle and tends to form cracks during processing. An advanced solid polymer electrolyte with optimum ionic conductivity and mechanical properties is developed by using a ternary system: TEGDME/PEO/NC+LiClO4. At room temperature, this electrolyte exhibits an ionic conductivity to the order of 10-5 S/cm, which is very high compared to that of the PEO/LiClO4 electrolyte. Pristine PEO electrolytes start melting at 65 °C and completely lose its mechanical strength. Dynamic mechanical analysis of TEGDME: PEO: NC (70:20:10 wt%) showed an improvement of storage modulus as compared to the pristine PEO in the 60–120 °C temperature range. Also, with an addition of NC, the electrolyte retains its mechanical integrity at 100 oC which is beneficial for Li-ion battery operation at high temperatures. Differential scanning calorimetry (DSC) and thermal gravimetry analysis (TGA) studies revealed that the ternary polymer electrolyte is thermally stable in the lithium ion battery operational temperature range. As-prepared polymer electrolyte was used to assemble LiFePO4/ TEGDME/PEO/NC+LiClO4/Li half cells and their electrochemical performance was studied via cyclic voltammetry and charge-discharge cycling.

Keywords: solid polymer electrolyte, ionic conductivity, mechanical properties, lithium ion batteries, cyclic voltammetry

Procedia PDF Downloads 394

Authors: James Kinyua Gitonga, Toshio Fujimi

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Vulnerability assessment and analysis is essential to solving the degree of damage and loss as a result of natural disasters. Urban flooding causes a major economic loss and casualties, at Mathare residential area in Nairobi, Kenya. High population caused by rural-urban migration, Unemployment, and unplanned urban development are among factors that increase flood vulnerability in Mathare area. This study aims to analyse flood risk physical vulnerabilities in Mathare based on scientific data, research data that includes the Rainfall data, River Mathare discharge rate data, Water runoff data, field survey data and questionnaire survey through sampling of the study area have been used to develop the risk curves. Three structural types of building were identified in the study area, vulnerability and risk curves were made for these three structural types by plotting the relationship between flood depth and damage for each structural type. The results indicate that the structural type with mud wall and mud floor is the most vulnerable building to flooding while the structural type with stone walls and concrete floor is least vulnerable. The vulnerability of building contents is mainly determined by the number of floors, where households with two floors are least vulnerable, and households with a one floor are most vulnerable. Therefore more than 80% of the residential buildings including the property in the building are highly vulnerable to floods consequently exposed to high risk. When estimating the potential casualties/injuries we discovered that the structural types of houses were major determinants where the mud/adobe structural type had casualties of 83.7% while the Masonry structural type had casualties of 10.71% of the people living in these houses. This research concludes that flood awareness, warnings and observing the building codes will enable reduce damage to the structural types of building, deaths and reduce damage to the building contents.

Keywords: flood loss, Mathare Nairobi, risk curve analysis, vulnerability

Procedia PDF Downloads 204