Search results for: elevated temperature
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 7506

Search results for: elevated temperature

4086 Studies on Non-Isothermal Crystallization Kinetics of PP/SEBS-g-MA Blends

Authors: Rishi Sharma, S. N. Maiti

Abstract:

The non-isothermal crystallization kinetics of PP/SEBS-g-MA blends up to 0-50% concentration of copolymer was studied by differential scanning calorimetry at four different cooling rates. Crystallization parameters were analyzed by Avrami and Jeziorny models. Primary and secondary crystallization processes were described by Avrami equation. Avrami model showed that all types of shapes grow from small dimensions during primary crystallization. However, three-dimensional crystal growth was observed during the secondary crystallization process. The crystallization peak and onset temperature decrease, however

Keywords: crystallization kinetics, non-isothermal, polypropylene, SEBS-g-MA

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4085 Theoretical Investigation of Proton-Bore Fusion in Hot Spots

Authors: Morteza Habibi

Abstract:

As an alternative to D–T fuel, one can consider advanced fuels like D3-He and p-11B fuels, which have potential advantages concerning availability and/or environmental impact. Hot spots are micron-sized magnetically self-contained sources observed in pinched plasma devices. In hot spots, fusion power for 120 keV < Ti < 800 keV and 32 keV < Te < 129 keV exceeds bremsstrahlung loss and fraction of fusion power to bremsstrahlung loss reaches to 1.9. In this case, gain factor for a 150 kJ typical pulsed generator as a hot spot source will be 7.8 which is considerable for a commercial pinched plasma device.

Keywords: P-B fuel, hot spot, bremmsstrahlung loss, ion temperature

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4084 Dengue Virus Infection Rate in Mosquitoes Collected in Thailand Related to Environmental Factors

Authors: Chanya Jetsukontorn

Abstract:

Dengue hemorrhagic fever is the most important Mosquito-borne disease and the major public health problem in Thailand. The most important vector is Aedes aegypti. Environmental factors such as temperature, relative humidity, and biting rate affect dengue virus infection. The most effective measure for prevention is controlling of vector mosquitoes. In addition, surveillance of field-caught mosquitoes is imperative for determining the natural vector and can provide an early warning sign at risk of transmission in an area. In this study, Aedes aegypti mosquitoes were collected in Amphur Muang, Phetchabun Province, Thailand. The mosquitoes were collected in the rainy season and the dry season both indoor and outdoor. During mosquito’s collection, the data of environmental factors such as temperature, humidity and breeding sites were observed and recorded. After identified to species, mosquitoes were pooled according to genus/species, and sampling location. Pools consisted of a maximum of 10 Aedes mosquitoes. 70 pools of 675 Aedes aegypti were screened with RT-PCR for flaviviruses. To confirm individual infection for determining True infection rate, individual mosquitoes which gave positive results of flavivirus detection were tested for dengue virus by RT-PCR. The infection rate was 5.93% (4 positive individuals from 675 mosquitoes). The probability to detect dengue virus in mosquitoes at the neighbour’s houses was 1.25 times, especially where distances between neighboring houses and patient’s houses were less than 50 meters. The relative humidity in dengue-infected villages with dengue-infected mosquitoes was significantly higher than villages that free from dengue-infected mosquitoes. Indoor biting rate of Aedes aegypti was 14.87 times higher than outdoor, and biting times of 09.00-10.00, 10.00-11.00, 11.00-12.00 yielded 1.77, 1.46, 0.68mosquitoes/man-hour, respectively. These findings confirm environmental factors were related to Dengue infection in Thailand. Data obtained from this study will be useful for the prevention and control of the diseases.

Keywords: Aedes aegypti, Dengue virus, environmental factors, one health, PCR

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4083 Biosynthesized Selenium Nanoparticles to Rescue Coccidiosis-mediated Oxidative Stress, Apoptosis and Inflammation in the Jejunum Of Mice

Authors: Esam Mohammed Al-shaebi

Abstract:

One of the most crucial approaches for treating human diseases, particularly parasite infections, is nanomedicine. One of the most significant protozoan diseases that impact farm and domestic animals is coccidiosis. While, amprolium is one of the traditional anticoccidial medication, the advent of drug-resistant strains of Eimeria necessitates the development of novel treatments. The goal of the current investigation was to determine whether biosynthesized selenium nanoparticles (Bio-SeNPs) using Azadirachta indica leaves extract might treat mice with Eimeria papillata infection in the jejunal tissue. Five groups of seven mice each were used, as follows: Group 1: Non-infected-non-treated (negative control). Group 2: Non-infected treated group with Bio-SeNPs (0.5 mg/kg of body weight). Groups 3-5 were orally inoculated with 1×103 sporulated oocysts of E. papillata. Group 3: Infected-non-treated (positive control). Group 4: Infected and treated group with Bio-SeNPs (0.5 mg/kg). Group 5: Infected and treated group with the Amprolium. Groups 4 and 5 daily received oral administration (for 5 days) of Bio-SeNPs and anticoccidial medication, respectively, after infection. Bio-SeNPs caused a considerable reduction in oocyst output in mice feces (97.21%). This was also accompanied by a significant reduction in the number of developmental parasitic stages in the jejunal tissues. Glutathione reduced (GSH), glutathione peroxidase (GPx), and superoxide dismutase (SOD) levels were dramatically reduced by the Eimeria parasite, whereas, nitric oxide (NO) and malonaldehyde (MDA) levels were markedly elevated. The amount of goblet cells and MUC2 gene expression were used as apoptotic indicators, and both were considerably downregulated by infection. However, infection markedly increased the expression of inflammatory cytokines (IL-6 and TNF-α) and the apoptotic genes (Caspase-3 and BCL2). Bio-SeNPs were administrated to mice to drastically lower body weight, oxidative stress, and inflammatory and apoptotic indicators in the jejunal tissue. Our research thus showed the involvement of Bio-SeNPs in protecting mice with E. papillata infections against jejunal damage.

Keywords: coccidiosis, nanoparticles, azadirachta indica, oxidative stress

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4082 Effects of Intracerebroventricular Injection of Ghrelin and Aerobic Exercise on Passive Avoidance Memory and Anxiety in Adult Male Wistar Rats

Authors: Mohaya Farzin, Parvin Babaei, Mohammad Rostampour

Abstract:

Ghrelin plays a considerable role in important neurological effects related to food intake and energy homeostasis. As was found, regular physical activity may make available significant improvements to cognitive functions in various behavioral situations. Anxiety is one of the main concerns of the modern world, affecting millions of individuals’ health. There are contradictory results regarding ghrelin's effects on anxiety-like behavior, and the plasma level of this peptide is increased during physical activity. Here we aimed to evaluate the coincident effects of exogenous ghrelin and aerobic exercise on anxiety-like behavior and passive avoidance memory in Wistar rats. Forty-five male Wistar rats (250 ± 20 g) were divided into 9 groups (n=5) and received intra-hippocampal injections of 3.0 nmol ghrelin and performed aerobic exercise training for 8 weeks. Control groups received the same volume of saline and diazepam as negative and positive control groups, respectively. Learning and memory were estimated using a shuttle box apparatus, and anxiety-like behavior was recorded by an elevated plus-maze test (EPM). Data were analyzed by ANOVA test, and p<0.05 was considered significant. Our findings showed that the combined effect of ghrelin and aerobic exercise improves the acquisition, consolidation, and retrieval of passive avoidance memory in Wistar rats. Furthermore, it is supposed that the ghrelin receiving group spent less time in open arms and fewer open arms entries compared with the control group (p<0.05). However, exercising Wistar rats spent more time in the open arm zone in comparison with the control group (p<0.05). The exercise + Ghrelin administration established reduced anxiety (p<0.05). The results of this study demonstrate that aerobic exercise contributes to an increase in the endogenous production of ghrelin, and physical activity alleviates anxiety-related behaviors induced by intra-hippocampal injection of ghrelin. In general, exercise and ghrelin can reduce anxiety and improve memory.

Keywords: anxiety, ghrelin, aerobic exercise, learning, passive avoidance memory

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4081 Contribution of Hydrogen Peroxide in the Selective Aspect of Prostate Cancer Treatment by Cold Atmospheric Plasma

Authors: Maxime Moreau, Silvère Baron, Jean-Marc Lobaccaro, Karine Charlet, Sébastien Menecier, Frédéric Perisse

Abstract:

Cold Atmospheric Plasma (CAP) is an ionized gas generated at atmospheric pressure with the temperature of heavy particles (molecules, ions, atoms) close to the room temperature. Recent studies have shown that both in-vitro and in-vivo plasma exposition to many cancer cell lines are efficient to induce the apoptotic way of cell death. In some other works, normal cell lines seem to be less impacted by plasma than cancer cell lines. This is called selectivity of plasma. It is highly likely that the generated RNOS (Reactive Nitrogen Oxygen Species) in the plasma jet, but also in the medium, play a key-role in this selectivity. In this study, two CAP devices will be compared to electrical power, chemical species composition and their efficiency to kill cancer cells. A particular focus on the action of hydrogen peroxide will be made. The experiments will take place as described next for both devices: electrical and spectroscopic characterization for different voltages, plasma treatment of normal and cancer cells to compare the CAP efficiency between cell lines and to show that death is induced by an oxidative stress. To enlighten the importance of hydrogen peroxide, an inhibitor of H2O2 will be added in cell culture medium before treatment and a comparison will be made between the results of cell viability in this case and those from a simple plasma exposition. Besides, H2O2 production will be measured by only treating medium with plasma. Cell lines will also be exposed to different concentrations of hydrogen peroxide in order to characterize the cytotoxic threshold for cells and to make a comparison with the quantity of H2O2 produced by CAP devices. Finally, the activity of catalase for different cell lines will be quantified. This enzyme is an important antioxidant agent against hydrogen peroxide. A correlation between cells response to plasma exposition and this activity could be a strong argument in favor of the predominant role of H2O2 to explain the selectivity of plasma cancer treatment by cold atmospheric plasma.

Keywords: cold atmospheric plasma, hydrogen peroxide, prostate cancer, selectivity

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4080 Interstellar Mission to Wolf 359: Possibilities for the Future

Authors: Rajasekar Anand Thiyagarajan

Abstract:

One of the driving forces of mankind is the “le r`eve d'etoiles" or the “dream of stars", which has been the dynamo of our civilization. Since the beginning of the dawn of the civilization, mankind has looked upon the heavens with wonder and he has tried to understand the meaning of those twinkling lights. As human history has progressed, the understanding of those twinkling lights has progressed, as we now know a lot of information about stars. However, the dream of stars or the dream of reaching those stars always remains within the expectations of mankind. In fact, the needs of the civilization constantly drive for better knowledge and the capability of reaching those stars is one such way that knowledge and exultation can be achieved. This paper takes a futuristic case study of an interstellar mission to Wolf 359, which is approximately 8.3 light years away from us. In terms of galactic distances, 8.3 light years is not much, but as far as present space technology capabilities are concerned, it is next to impossible for us to reach those distances. Several studies have been conducted on various missions to Alpha Centauri and other nearby stars such as Barnard's star and Wolf 359. However, taking a more distant star such as Wolf 359 will help test the mankind's drive for interstellar exploration, as exotic means of travel are needed. This paper will take a futuristic case study of the event and various possibilities of space travel will be discussed in detail. Comprehensive tables and graphs will be given, which will depict the amount of time that will pass at each mode of travel and more importantly some idea on the cost in terms of energy as well as money will be discussed within today's context. In addition, prerequisites to an interstellar mission to Wolf 359 will be given in detail as well as a sample mission which will take place to that particular destination. Even though the possibility of such a mission is probably nonexistent for the 21st century, it is essential to do these exercises so that mankind's understanding of the universe will be increased. In addition, this paper hopes to establish some general guidelines for such an interstellar mission.

Keywords: wolf 359, interstellar mission, alpha centauri, core diameter, core length, reflector thickness enrichment, gas temperature, reflector temperature, power density, mass of the space craft, acceleration of the space craft, time expansion

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4079 Optimization of Alkali Assisted Microwave Pretreatments of Sorghum Straw for Efficient Bioethanol Production

Authors: Bahiru Tsegaye, Chandrajit Balomajumder, Partha Roy

Abstract:

The limited supply and related negative environmental consequence of fossil fuels are driving researcher for finding sustainable sources of energy. Lignocellulose biomass like sorghum straw is considered as among cheap, renewable and abundantly available sources of energy. However, lignocellulose biomass conversion to bioenergy like bioethanol is hindered due to the reluctant nature of lignin in the biomass. Therefore, removal of lignin is a vital step for lignocellulose conversion to renewable energy. The aim of this study is to optimize microwave pretreatment conditions using design expert software to remove lignin and to release maximum possible polysaccharides from sorghum straw for efficient hydrolysis and fermentation process. Sodium hydroxide concentration between 0.5-1.5%, v/v, pretreatment time from 5-25 minutes and pretreatment temperature from 120-2000C were considered to depolymerize sorghum straw. The effect of pretreatment was studied by analyzing the compositional changes before and after pretreatments following renewable energy laboratory procedure. Analysis of variance (ANOVA) was used to test the significance of the model used for optimization. About 32.8%-48.27% of hemicellulose solubilization, 53% -82.62% of cellulose release, and 49.25% to 78.29% lignin solubilization were observed during microwave pretreatment. Pretreatment for 10 minutes with alkali concentration of 1.5% and temperature of 1400C released maximum cellulose and lignin. At this optimal condition, maximum of 82.62% of cellulose release and 78.29% of lignin removal was achieved. Sorghum straw at optimal pretreatment condition was subjected to enzymatic hydrolysis and fermentation. The efficiency of hydrolysis was measured by analyzing reducing sugars by 3, 5 dinitrisylicylic acid method. Reducing sugars of about 619 mg/g of sorghum straw were obtained after enzymatic hydrolysis. This study showed a significant amount of lignin removal and cellulose release at optimal condition. This enhances the yield of reducing sugars as well as ethanol yield. The study demonstrates the potential of microwave pretreatments for enhancing bioethanol yield from sorghum straw.

Keywords: cellulose, hydrolysis, lignocellulose, optimization

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4078 LIFirr with an Indicator of Microbial Activity in Paraffinic Oil

Authors: M. P. Casiraghi, C. M. Quintella, P. Almeida

Abstract:

Paraffinic oils were submitted to microbial action. The microorganisms consisted of bacteria of the genera Pseudomonas sp and Bacillus lincheniforms. The alterations in interfacial tension were determined using a tensometer and applying the hanging drop technique at room temperature (299 K ±275 K). The alteration in the constitution of the paraffins was evaluated by means of gas chromatography. The microbial activity was observed to reduce interfacial tension by 54 to 78%, as well as consuming the paraffins C19 to C29 and producing paraffins C36 to C44. The LIFirr technique made it possible to determine the microbial action quickly.

Keywords: paraffins, biosurfactants, LIFirr, microbial activity

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4077 Structural Health Monitoring using Fibre Bragg Grating Sensors in Slab and Beams

Authors: Pierre van Tonder, Dinesh Muthoo, Kim twiname

Abstract:

Many existing and newly built structures are constructed on the design basis of the engineer and the workmanship of the construction company. However, when considering larger structures where more people are exposed to the building, its structural integrity is of great importance considering the safety of its occupants (Raghu, 2013). But how can the structural integrity of a building be monitored efficiently and effectively. This is where the fourth industrial revolution step in, and with minimal human interaction, data can be collected, analysed, and stored, which could also give an indication of any inconsistencies found in the data collected, this is where the Fibre Bragg Grating (FBG) monitoring system is introduced. This paper illustrates how data can be collected and converted to develop stress – strain behaviour and to produce bending moment diagrams for the utilisation and prediction of the structure’s integrity. Embedded fibre optic sensors were used in this study– fibre Bragg grating sensors in particular. The procedure entailed making use of the shift in wavelength demodulation technique and an inscription process of the phase mask technique. The fibre optic sensors considered in this report were photosensitive and embedded in the slab and beams for data collection and analysis. Two sets of fibre cables have been inserted, one purposely to collect temperature recordings and the other to collect strain and temperature. The data was collected over a time period and analysed used to produce bending moment diagrams to make predictions of the structure’s integrity. The data indicated the fibre Bragg grating sensing system proved to be useful and can be used for structural health monitoring in any environment. From the experimental data for the slab and beams, the moments were found to be64.33 kN.m, 64.35 kN.m and 45.20 kN.m (from the experimental bending moment diagram), and as per the idealistic (Ultimate Limit State), the data of 133 kN.m and 226.2 kN.m were obtained. The difference in values gave room for an early warning system, in other words, a reserve capacity of approximately 50% to failure.

Keywords: fibre bragg grating, structural health monitoring, fibre optic sensors, beams

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4076 Learning from Flood: A Case Study of a Frequently Flooded Village in Hubei, China

Authors: Da Kuang

Abstract:

Resilience is a hotly debated topic in many research fields (e.g., engineering, ecology, society, psychology). In flood management studies, we are experiencing the paradigm shift from flood resistance to flood resilience. Flood resilience refers to tolerate flooding through adaptation or transformation. It is increasingly argued that our city as a social-ecological system holds the ability to learn from experience and adapt to flood rather than simply resist it. This research aims to investigate what kinds of adaptation knowledge the frequently flooded village learned from past experience and its advantages and limitations in coping with floods. The study area – Xinnongcun village, located in the west of Wuhan city, is a linear village and continuously suffered from both flash flood and drainage flood during the past 30 years. We have a field trip to the site in June 2017 and conducted semi-structured interviews with local residents. Our research summarizes two types of adaptation knowledge that people learned from the past floods. Firstly, at the village scale, it has formed a collective urban form which could help people live during both flood and dry season. All houses and front yards were elevated about 2m higher than the road. All the front yards in the village are linked and there is no barrier. During flooding time, people walk to neighbors through houses yards and boat to outside village on the lower road. Secondly, at individual scale, local people learned tacit knowledge of preparedness and emergency response to flood. Regarding the advantages and limitations, the adaptation knowledge could effectively help people to live with flood and reduce the chances of getting injuries. However, it cannot reduce local farmers’ losses on their agricultural land. After flood, it is impossible for local people to recover to the pre-disaster state as flood emerges during June and July will result in no harvest. Therefore, we argue that learning from past flood experience could increase people’s adaptive capacity. However, once the adaptive capacity cannot reduce people’s losses, it requires a transformation to a better regime.

Keywords: adaptation, flood resilience, tacit knowledge, transformation

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4075 Effect of Climate Variability on Children Health Outcomes in Rural Uganda

Authors: Emily Injete Amondo, Alisher Mirzabaev, Emmanuel Rukundo

Abstract:

Children in rural farming households are often vulnerable to a multitude of risks, including health risks associated with climate change and variability. Cognizant of this, this study empirically traced the relationship between climate variability and nutritional health outcomes in rural children while identifying the cause-and-effect transmission mechanisms. We combined four waves of the rich Uganda National Panel Survey (UNPS), part of the World Bank Living Standards Measurement Studies (LSMS) for the period 2009-2014, with long-term and high-frequency rainfall and temperature datasets. Self-reported drought and flood shock variables were further used in separate regressions for triangulation purposes and robustness checks. Panel fixed effects regressions were applied in the empirical analysis, accounting for a variety of causal identification issues. The results showed significant negative outcomes for children’s anthropometric measurements due to the impacts of moderate and extreme droughts, extreme wet spells, and heatwaves. On the contrary, moderate wet spells were positively linked with nutritional measures. Agricultural production and child diarrhea were the main transmission channels, with heatwaves, droughts, and high rainfall variability negatively affecting crop output. The probability of diarrhea was positively related to increases in temperature and dry spells. Results further revealed that children in households who engaged in ex-ante or anticipatory risk-reducing strategies such as savings had better health outcomes as opposed to those engaged in ex-post coping such as involuntary change of diet. These results highlight the importance of adaptation in smoothing the harmful effects of climate variability on the health of rural households and children in Uganda.

Keywords: extreme weather events, undernutrition, diarrhea, agricultural production, gridded weather data

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4074 Characterization of Ethanol-Air Combustion in a Constant Volume Combustion Bomb Under Cellularity Conditions

Authors: M. Reyes, R. Sastre, P. Gabana, F. V. Tinaut

Abstract:

In this work, an optical characterization of the ethanol-air laminar combustion is presented in order to investigate the origin of the instabilities developed during the combustion, the onset of the cellular structure and the laminar burning velocity. Experimental tests of ethanol-air have been developed in an optical cylindrical constant volume combustion bomb equipped with a Schlieren technique to record the flame development and the flame front surface wrinkling. With this procedure, it is possible to obtain the flame radius and characterize the time when the instabilities are visible through the cell's apparition and the cellular structure development. Ethanol is an aliphatic alcohol with interesting characteristics to be used as a fuel in Internal Combustion Engines and can be biologically synthesized from biomass. Laminar burning velocity is an important parameter used in simulations to obtain the turbulent flame speed, whereas the flame front structure and the instabilities developed during the combustion are important to understand the transition to turbulent combustion and characterize the increment in the flame propagation speed in premixed flames. The cellular structure is spontaneously generated by volume forces, diffusional-thermal and hydrodynamic instabilities. Many authors have studied the combustion of ethanol air and mixtures of ethanol with other fuels. However, there is a lack of works that investigate the instabilities and the development of a cellular structure in ethanol flames, a few works as characterized the ethanol-air combustion instabilities in spherical flames. In the present work, a parametrical study is made by varying the fuel/air equivalence ratio (0.8-1.4), initial pressure (0.15-0.3 MPa) and initial temperature (343-373K), using a design of experiments type I-optimal. In reach mixtures, it is possible to distinguish the cellular structure formed by the hydrodynamic effect and by from the thermo-diffusive. Results show that ethanol-air flames tend to stabilize as the equivalence ratio decreases in lean mixtures and develop a cellular structure with the increment of initial pressure and temperature.

Keywords: ethanol, instabilities, premixed combustion, schlieren technique, cellularity

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4073 Programmable Shields in Space

Authors: Tapas Kumar Sinha, Joseph Mathew

Abstract:

At the moment earth is in grave danger due to threats of global warming. The temperature of the earth has risen by almost 20C. Glaciers in the Arctic have started to melt. It would be foolhardy to think that this is a small effect and in time it would go away. Global warming is caused by a number of factors. However, one sure and simple way to totally eliminate this problem is to put programmable shields in space. Just as an umbrella blocks sunlight, a programmable shield in space will block sun rays from reaching the earth as in a solar eclipse and cause cooling in the penumbral region just as it happens during an eclipse.

Keywords: glaciers, green house, global warming space, satellites

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4072 Impect of Human on Prey of Birds in North West Rajasthan

Authors: Dau Lal Bohra, Sradha Vyas

Abstract:

Bird species are already showing climate-related changes in the dates they migrate and breed, and in the timing of other key life-history events. Treats of feeding managements raptors have performed important ecological, traditional and aesthetic functions throughout the Indian subcontinent. The declines in India result from elevated adult and juvenile mortality, and low breeding success. The widespread and rapid pattern of declines, i.e. in all areas irrespective of habitat or protection status suggest that persecution through shooting or poisoning, whilst important at a local scale, are unlikely to have caused the declines. A mass killing of several species of vultures in the Indian subcontinent over the last two decades is largely blamed on the presence of a drug. Veterinary diclofenac caused an unprecedented decline in South Asia’s Gyps vulture populations, with some species declining by more than 97% between 1992 and 2007. Veterinary diclofenac causes renal failure in vultures, and killed tens of millions of such birds in the Indian sub-continent. The drug was finally banned there for veterinary purposes in 2006. This drug is now ‘a global problem’ threatening many vulnerable birds of prey. Recently, stappe eagles are also susceptible to veterinary diclofenac, effectively increasing the potential threat level, and the risks for European biodiversity. Steppe eagles are closely related with golden eagles (Aquila chrysaetus), imperial eagles (Aquila heliaca) and Spanish imperial eagles (Aquila adalberti), and all these species scavenge opportunistically on carcasses throughout their range. The Spanish imperial eagle, considered Vulnerable at global level, is now particularly at risk, due to the availability of diclofenac in Spain. These findings strengthen the case for banning veterinary diclofenac across. From year 2011 to 2014 more than 300 hundred birds dead in jorbeer, Bikaner. Now, with unequivocal evidence that this veterinary drug can cause a much wider impact on Europe´s biodiversity, it is time for action – please ban diclofenac human brand also in multi-dose vial from market.

Keywords: mortility, prey of birds, diclofenac, Rajasthan

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4071 Investigating Constructions and Operation of Internal Combustion Engine Water Pumps

Authors: Michał Gęca, Konrad Pietrykowski, Grzegorz Barański

Abstract:

The water pump in the compression-ignition internal combustion engine transports a hot coolant along a system of ducts from the engine block to the radiator where coolant temperature is lowered. This part needs to maintain a constant volumetric flow rate. Its power should be regulated to avoid a significant drop in pressure if a coolant flow decreases. The internal combustion engine cooling system uses centrifugal pumps for suction. The paper investigates 4 constructions of engine pumps. The pumps are from diesel engine of a maximum power of 75 kW. Each of them has a different rotor shape, diameter and width. The test stand was created and the geometry inside the all 4 engine blocks was mapped. For a given pump speed on the inverter of the electric engine motor, the valve position was changed and volumetric flow rate, pressure, and power were recorded. Pump speed was regulated from 1200 RPM to 7000 RPM every 300 RPM. The volumetric flow rates and pressure drops for the pump speeds and efficiencies were specified. Accordingly, the operations of each pump were mapped. Our research was to select a pump for the aircraft compression-ignition engine. There was calculated a pressure drop at a given flow on the block and radiator of the designed aircraft engine. The water pump should be lightweight and have a low power demand. This fact shall affect the shape of a rotor and bearings. The pump volumetric flow rate was assumed as 3 kg/s (previous AVL BOOST research model) where the temperature difference was 5°C between the inlet (90°C) and outlet (95°C). Increasing pump speed above the boundary flow power defined by pressure and volumetric flow rate does not increase it but pump efficiency decreases. The maximum total pump efficiency (PCC) is 45-50%. When the pump is driven by low speeds with a 90% closed valve, its overall efficiency drops to 15-20%. Acknowledgement: This work has been realized in the cooperation with The Construction Office of WSK "PZL-KALISZ" S.A." and is part of Grant Agreement No. POIR.01.02.00-00-0002/15 financed by the Polish National Centre for Research and Development.

Keywords: aircraft engine, diesel engine, flow, water pump

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4070 Ecological and Health Risk Assessment of the Heavy Metal Contaminant in Surface Soils around Effurun Market

Authors: A. O. Ogunkeyede, D. Amuchi, A. A. Adebayo

Abstract:

Heavy metal contaminations in soil have received great attention. Anthropogenic activities such as vehicular emission, industrial activities and constructions have resulted in elevated concentration of heavy metals in the surface soils. The metal particles can be free from the surface soil when they are disturbed and re-entrained in air, which necessitated the need to investigate surface soil at market environment where adults and children are present on daily basis. This study assesses concentration of heavy metal pollution, ecological and health risk factors in surface soil at Effurun market. 8 samples were collected at household material (EMH), fish (EMFs), fish and commodities (EMF-C), Abattoir (EMA 1 & 2), fruit sections (EMF 1 & 2) and lastly main road (EMMR). The samples were digested and analyzed in triplicate for contents of Lead (Pb), Nickel (Ni), Cadmium (Cd) and Copper (Cu). The mean concentration of the Pb mg/kg (112.27 ± 1.12) and Cu mg/kg (156.14 ± 1.10) were highest in the abattoir section (EMA 1). The mean concentrations of the heavy metal were then used to calculate the ecological and health risk for people within the market. Pb contamination at EMMR, EMF 2, EMFs were moderately while Pb shows considerable contamination at EMH, EMA 1, EMA 2 and EMF-C sections of the Effurun market. The ecological risk factor varies between low to moderate pollution for Pb and EMA 1 has the highest potential ecological risk that falls within moderate pollution. The hazard quotient results show that dermal exposure pathway is the possible means of heavy metal exposure to the traders while ingestion is the least sources of exposure to adult. The ingestion suggested that children around the EMA 1 have the highest possible exposure to children due to hand-to-mouth and object-to-mouth behaviour. The results further show that adults at the EMA1 will have the highest exposure to Pb due to inhalation during burning of cow with tyre that contained Pb and Cu. The carcinogenic risk values of most sections were higher than acceptable values, while Ni at EMMR, EMF 1 & 2, EMFs and EMF-C sections that were below the acceptable values. The cancer risk for inhalation exposure pathway for Pb (1.01E+17) shows a significant level of contamination than all the other sections of the market. It suggested that the people working at the Abattoir were very prone to cancer risk.

Keywords: carcinogenic, ecological, heavy metal, risk

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4069 Material Concepts and Processing Methods for Electrical Insulation

Authors: R. Sekula

Abstract:

Epoxy composites are broadly used as an electrical insulation for the high voltage applications since only such materials can fulfill particular mechanical, thermal, and dielectric requirements. However, properties of the final product are strongly dependent on proper manufacturing process with minimized material failures, as too large shrinkage, voids and cracks. Therefore, application of proper materials (epoxy, hardener, and filler) and process parameters (mold temperature, filling time, filling velocity, initial temperature of internal parts, gelation time), as well as design and geometric parameters are essential features for final quality of the produced components. In this paper, an approach for three-dimensional modeling of all molding stages, namely filling, curing and post-curing is presented. The reactive molding simulation tool is based on a commercial CFD package, and include dedicated models describing viscosity and reaction kinetics that have been successfully implemented to simulate the reactive nature of the system with exothermic effect. Also a dedicated simulation procedure for stress and shrinkage calculations, as well as simulation results are presented in the paper. Second part of the paper is dedicated to recent developments on formulations of functional composites for electrical insulation applications, focusing on thermally conductive materials. Concepts based on filler modifications for epoxy electrical composites have been presented, including the results of the obtained properties. Finally, having in mind tough environmental regulations, in addition to current process and design aspects, an approach for product re-design has been presented focusing on replacement of epoxy material with the thermoplastic one. Such “design-for-recycling” method is one of new directions associated with development of new material and processing concepts of electrical products and brings a lot of additional research challenges. For that, one of the successful products has been presented to illustrate the presented methodology.

Keywords: curing, epoxy insulation, numerical simulations, recycling

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4068 Improving the Competency of Undergraduate Nursing Students in Addressing a Timely Public Health Issue

Authors: Tsu-Yin Wu, Jenni Hoffman, Lydia McMurrows, Sarah Lally

Abstract:

Recent events of the Flint Water Crisis and elevated lead levels in Detroit public school water have highlighted a specific public health disparity and shown the need for better education of healthcare providers on lead education. Identifying children and pregnant women with a high risk for lead poisoning and ensuring lead testing is completed is critical. The purpose of this study is to explore the impact of an educational intervention on knowledge and confidence levels among nursing students enrolled in the prelicensure Bachelor of Science in Nursing (BSN) and Registered Nurse to BSN program (R2B). The study used both quantitative and qualitative research methods to assess the impact of multi-modal pedagogy on knowledge and confidence of lead screening and prevention among prelicensure and R2B nursing students. The students received lead poisoning and prevention content in addition to completing an e-learning module developed by the Pediatric Environmental Health Specialty Units. A total of 115 students completed the pre-and post-test instrument that consisted of demographic, lead knowledge, and confidence items. Despite the increase of total knowledge, three dimensions of lead poisoning, and confidence from pre- to post-test scores for both groups, there was no statistical significance on the increase between prelicensure and R2B students. Thematic analysis of qualitative data showed five themes from participants' learning experiences: lead exposure, signs and symptoms of lead poisoning, screening and diagnosis, prevention, and policy and statewide issues. The study is limited by a small sample and participants recalling some correct answers from the pretest, thus, scoring higher on the post-test. The results contribute to the minimally existent literature examining a critical public health concern regarding lead health exposure and prevention education of nursing students. Incorporating such content area into the nursing curriculum is essential in ensuring that such public health disparities are mitigated.

Keywords: lead poisoning, emerging public health issue, community health, nursing edducation

Procedia PDF Downloads 194
4067 COX-2 Inhibitor NS398 Counteracts Chemoresistance to Temozolomide in T98G Glioblastoma Cell Line

Authors: Francesca Lombardi, Francesca Rosaria Augello, Benedetta Cinque, Maria Grazia Cifone, Paola Palumbo

Abstract:

Glioblastoma multiforme (GBM) is a high-grade primary brain tumor refractory to current forms of treatment. The survival benefits of patients with GBM remain unsatisfactory due to the intrinsic or acquired resistance to temozolomide (TMZ), an alkylating agent, used as the first-line chemotherapeutic drug to treat GBM patients. Its cytotoxic effect is visualized by the induction of O6-methylguanine (O6MeG) within DNA. Cyclooxygenase-2 (COX-2), an inflammation-associated enzyme, has been implicated in tumorigenesis and progression of GBM, its inhibition shows anticancer activities. In the present study, it was verified if the combination of a COX-2 selective inhibitor, NS398, with TMZ could counteract the TMZ resistance. In particular, the effect of NS398 mixed with TMZ was investigated in the GBM TMZ-resistant cell line, T98G. Cells were pretreated with NS398 (100µM, 24 hours) and then exposed to TMZ alone (200µM), NS398 alone, or both for 72 hours, after which cell growth rate and cycle phases, as well as apoptosis level, were evaluated. Coadministration of NS398 and TMZ caused a significant decrease in cell growth and a progressive increase of dead cells detected by trypan blue staining. Moreover, a significant level of apoptotic cell percentage and alteration of cell cycle phases were observed in T98G treated with TMZ-NS398 combination when compared to untreated cells or TMZ-treated cells. TMZ-resistant tumors, as GBM, express elevated levels of DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT). The mixture drastically reduced MGMT expression in the TMZ-resistant cell line T98G, known to express high levels of MGMT basically. Moreover, while TMZ alone did not influence the COX-2 protein expression, the combination successfully reduced it. In conclusion, these results demonstrated that NS398 enhanced the efficacy of TMZ through cell number reduction, apoptosis induction, and decreased MGMT levels, suggesting the ability of drug combination to reduce the chemoresistance. This drug combination deserves attention and could be considered as a promising therapeutic strategy for GBM patients.

Keywords: COX-2, COX-2 inhibitor, glioblastoma, NS398, T98G, temozolomide

Procedia PDF Downloads 147
4066 A Study on Thermal and Flow Characteristics by Solar Radiation for Single-Span Greenhouse by Computational Fluid Dynamics Simulation

Authors: Jonghyuk Yoon, Hyoungwoon Song

Abstract:

Recently, there are lots of increasing interest in a smart farming that represents application of modern Information and Communication Technologies (ICT) into agriculture since it provides a methodology to optimize production efficiencies by managing growing conditions of crops automatically. In order to obtain high performance and stability for smart greenhouse, it is important to identify the effect of various working parameters such as capacity of ventilation fan, vent opening area and etc. In the present study, a 3-dimensional CFD (Computational Fluid Dynamics) simulation for single-span greenhouse was conducted using the commercial program, Ansys CFX 18.0. The numerical simulation for single-span greenhouse was implemented to figure out the internal thermal and flow characteristics. In order to numerically model solar radiation that spread over a wide range of wavelengths, the multiband model that discretizes the spectrum into finite bands of wavelength based on Wien’s law is applied to the simulation. In addition, absorption coefficient of vinyl varied with the wavelength bands is also applied based on Beer-Lambert Law. To validate the numerical method applied herein, the numerical results of the temperature at specific monitoring points were compared with the experimental data. The average error rates (12.2~14.2%) between them was shown and numerical results of temperature distribution are in good agreement with the experimental data. The results of the present study can be useful information for the design of various greenhouses. This work was supported by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries (IPET) through Advanced Production Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA)(315093-03).

Keywords: single-span greenhouse, CFD (computational fluid dynamics), solar radiation, multiband model, absorption coefficient

Procedia PDF Downloads 133
4065 Trehalose Application Increased Membrane Stability and Cell Viability to Affect Growth of Wheat Genotypes under Heat Stress

Authors: S. K. Thind, Aparjot Kaur

Abstract:

Heat stress is one of the major environmental factors drastically reducing wheat production. Crop heat tolerance can be enhanced by preconditioning of plants by exogenous application of osmoprotectants. Presently, the effect of trehalose pretreatment (at 1 mM, and 1.5 nM) under heat stress of 35±2˚C (moderate) and 40±2˚ (severe) for four and eight hour was conducted in wheat (Tricticum aestivum L.) genotypes viz. HD2967, PBW 175, PBW 343, PBW 621, and PBW 590. Heat stress affects wide spectrum of physiological processes within plants that are irreversibly damaged by stress. Membrane thermal stability (MTS) and cell viability was significantly decreased under heat stress for eight hours. Pretreatment with trehalose improved MTS and cell viability under stress and this effect was more promotory with higher concentration. Thermal stability of photosynthetic apparatus differed markedly between genotypes and Hill reaction activity was recorded more in PBW621 followed by C306 as compared with others. In all genotypes photolysis of water showed decline with increase in temperature stress. Trehalose pretreatment helped in sustaining Hill reaction activity probably by stabilizing the photosynthetic apparatus against heat-induced photo inhibition. Both plant growth and development were affected by temperature in both shoot and root under heat stress. The reduction was compensated partially by trehalose (1.5 mM) application. Adaption to heat stress is associated with the metabolic adjustment which led to accumulation of soluble sugars including non-reducing and reducing for their role in adaptive mechanism. Higher acid invertase activity in shoot of tolerant genotypes appeared to be a characteristic for stress tolerance. As sucrose synthase play central role in sink strength and in studied wheat genotype was positively related to dry matter accumulation. The duration of heat stress for eight hours had more severe effect on these parameters and trehalose application at 1.5 mM ameliorated it to certain extent.

Keywords: heat stress, Triticum aestivum, trehalose, membrane thermal stability, triphenyl tetrazolium chloride, reduction test, growth, sugar metabolism

Procedia PDF Downloads 321
4064 Localized Variabilities in Traffic-related Air Pollutant Concentrations Revealed Using Compact Sensor Networks

Authors: Eric A. Morris, Xia Liu, Yee Ka Wong, Greg J. Evans, Jeff R. Brook

Abstract:

Air quality monitoring stations tend to be widely distributed and are often located far from major roadways, thus, determining where, when, and which traffic-related air pollutants (TRAPs) have the greatest impact on public health becomes a matter of extrapolation. Compact, multipollutant sensor systems are an effective solution as they enable several TRAPs to be monitored in a geospatially dense network, thus filling in the gaps between conventional monitoring stations. This work describes two applications of one such system named AirSENCE for gathering actionable air quality data relevant to smart city infrastructures. In the first application, four AirSENCE devices were co-located with traffic monitors around the perimeter of a city block in Oshawa, Ontario. This study, which coincided with the COVID-19 outbreak of 2020 and subsequent lockdown measures, demonstrated a direct relationship between decreased traffic volumes and TRAP concentrations. Conversely, road construction was observed to cause elevated TRAP levels while reducing traffic volumes, illustrating that conventional smart city sensors such as traffic counters provide inadequate data for inferring air quality conditions. The second application used two AirSENCE sensors on opposite sides of a major 2-way commuter road in Toronto. Clear correlations of TRAP concentrations with wind direction were observed, which shows that impacted areas are not necessarily static and may exhibit high day-to-day variability in air quality conditions despite consistent traffic volumes. Both of these applications provide compelling evidence favouring the inclusion of air quality sensors in current and future smart city infrastructure planning. Such sensors provide direct measurements that are useful for public health alerting as well as decision-making for projects involving traffic mitigation, heavy construction, and urban renewal efforts.

Keywords: distributed sensor network, continuous ambient air quality monitoring, Smart city sensors, Internet of Things, traffic-related air pollutants

Procedia PDF Downloads 69
4063 Production of Pre-Reduction of Iron Ore Nuggets with Lesser Sulphur Intake by Devolatisation of Boiler Grade Coal

Authors: Chanchal Biswas, Anrin Bhattacharyya, Gopes Chandra Das, Mahua Ghosh Chaudhuri, Rajib Dey

Abstract:

Boiler coals with low fixed carbon and higher ash content have always challenged the metallurgists to develop a suitable method for their utilization. In the present study, an attempt is made to establish an energy effective method for the reduction of iron ore fines in the form of nuggets by using ‘Syngas’. By devolatisation (expulsion of volatile matter by applying heat) of boiler coal, gaseous product (enriched with reducing agents like CO, CO2, H2, and CH4 gases) is generated. Iron ore nuggets are reduced by this syngas. For that reason, there is no direct contact between iron ore nuggets and coal ash. It helps to control the minimization of the sulphur intake of the reduced nuggets. A laboratory scale devolatisation furnace designed with reduction facility is evaluated after in-depth studies and exhaustive experimentations including thermo-gravimetric (TG-DTA) analysis to find out the volatile fraction present in boiler grade coal, gas chromatography (GC) to find out syngas composition in different temperature and furnace temperature gradient measurements to minimize the furnace cost by applying one heating coil. The nuggets are reduced in the devolatisation furnace at three different temperatures and three different times. The pre-reduced nuggets are subjected to analytical weight loss calculations to evaluate the extent of reduction. The phase and surface morphology analysis of pre-reduced samples are characterized using X-ray diffractometry (XRD), energy dispersive x-ray spectrometry (EDX), scanning electron microscopy (SEM), carbon sulphur analyzer and chemical analysis method. Degree of metallization of the reduced nuggets is 78.9% by using boiler grade coal. The pre-reduced nuggets with lesser sulphur content could be used in the blast furnace as raw materials or coolant which would reduce the high quality of coke rate of the furnace due to its pre-reduced character. These can be used in Basic Oxygen Furnace (BOF) as coolant also.

Keywords: alternative ironmaking, coal gasification, extent of reduction, nugget making, syngas based DRI, solid state reduction

Procedia PDF Downloads 257
4062 Static Relaxation of Glass Fiber Reinforced Pipes

Authors: Mohammed Y. Abdellah, Mohamed K. Hassan, A. F. Mohamed, Shadi M. Munshi, A. M. Hashem

Abstract:

Pips made from glass fiber reinforced polymer has competitive role in petroleum industry. The need of evaluating the mechanical behavior of (GRP) pipes is essential objects. Stress relaxation illustrates how polymers relieve stress under constant strain. Static relaxation test is carried out at room temperature. The material gives poor static relaxation strength, two loading cycles have been observed for the tested specimen.

Keywords: GRP, sandwich composite material, static relaxation, stress relief

Procedia PDF Downloads 621
4061 Effects of Effort and Water Quality on Productivity (CPUE) of Hampal (Hampala macrolepidota) Resources in Jatiluhur Dam, West Java

Authors: Ririn Marinasari, S. Pi

Abstract:

Hampal (Hampala macrolepidota) is one of Citarum river indigenous fishes that still find in Jatiluhur dam. IUCN at 2013 said that hampal listed on redlist species category, this species was rare in Jatiluhur dam. This species more and more decreasing because change of habitats characteristic such as water quality and fishing effort. This study aims to determine and identify the influence of fishing effort and the quality of water on the productivity of fish resources hampal (Hampala macrolepidota) in Jatiluhur. The study was conducted from October to November 2013. Zones of research include lacustrine zone, transition and Riverin. Hampal fish productivity value computed by Hampal’s CPUE values. The results showed that fish MSY hampal obtained from surplus production model of Schaefer is equal to 0.2045 tons / quarterly. In the years 2011-2012 have occurred over fishing in 2013 while still under fishing. Total catches have exceeded the MSY during the year 2011 and the third quarterly of 2012 tons of fish that exceed 0.2045 hampal. The rate of utilization of fish resources hampal is equal to 80% of MSY or equal to the allowable catch (Total Allowable Catch) for fish in Jatiluhur hampal based Schaefer surplus production theory. Fishing effort, water quality parameters such as DO, turbidity and negatively correlated sulfide as H2S, while the temperature and pH positively correlated to productivity or unit catches fish hampal efforts in quarterly time series in the period 2011-2013. Shows that the higher fishing effort, DO, turbidity and sulfide in H2S and diminishing the temperature and pH of the productivity decreases. Variables that affect the productivity of fishing hampal only H2S only factor beta coefficient -0.834 which indicates a negative effect. It can be caused by H2S levels are toxic and have already exceeded the quality standard, while for other water quality parameters are still below the maximum standards allowed in the waters. Result of the study can be a reference of fishing regulation for hampal conservation in Jatiluhur dam.

Keywords: effort, hampal, productivity, water quality

Procedia PDF Downloads 292
4060 Trends in Endoscopic Versus Open Treatment of Carpal Tunnel Syndrome in Rheumatoid Arthritis Patients

Authors: Arman Kishan, Sanjay Kubsad, Steve Li, Mark Haft, Duc Nguyen, Dawn Laporte

Abstract:

Objective: Carpal tunnel syndrome can be managed surgically with endoscopic or open carpal tunnel release (CTR). Rheumatoid arthritis (RA) is a known risk factor for Carpal Tunnel Syndrome (CTS) and is believed to be related to compression of the median nerve secondary to inflammation. We aimed to analyze national trends, outcomes, and patient-specific comorbidities associated with ECTR and OCTR in patients with RA. Methods: A retrospective cohort study was conducted using the PearlDiver database, identifying 683 RA patients undergoing ECTR and 4234 undergoing OCTR between 2010 and 2014. Demographic data, comorbidities, and complication rates were analyzed. Univariate and multivariable analyses assessed differences between the treatment methods. Results:  Patients with RA undergoing ECTR in comparison to OCTR had no significant differences in medical comorbidities such as hypertension, obesity, chronic kidney disease, hypothyroidism and diabetes mellitus. Patients in the ECTR group reported a risk ratio of 1.44 (95%CI: 1.10-1.89, p=0.01) of requiring repeat procedures within 90 days of the initial procedure. Five-year trends in ECTR and OCTR procedures reported a combined annual growth rate of 5.6% and 13.15, respectively. Conclusion: Endoscopic and open approaches to CTR are important considerations in surgical planning. RA and ECTR have previously been identified as independent risk factors for revision CTR. Our study has identified the 90-day risk of repeat procedures to be elevated in the ECTR group in comparison to the OCTR group. Additionally, the growth of OCTR procedures has outpaced the growth of ECTR procedures in the same period, likely in response to the trend of ECTR leading to higher rates of repeat procedures. The need for revision following ECTR in patients with RA could be related to chronic inflammation leading to transverse carpal ligament thickening and concomitant tenosynovitis. Future directions could include further characterization of repeat procedures performed in this subset of patients. 

Keywords: endoscopic treatment of carpal tunnel syndrome, open treatment of carpal tunnel syndrome, rheumatoid arthritis, trends analysis, carpal tunnel syndrome

Procedia PDF Downloads 61
4059 Application of Flue Gas Recirculation in Fluidized Bed Combustor for Energy Efficiency Enhancement

Authors: Chien-Song Chyang

Abstract:

For a fluidized-bed combustion system, excess air ratio (EAR) and superficial velocity are major operating parameters affecting combustion behaviors, and these 2 factors are dependent variables since both fluidizing gas and combustion-supporting agent are air. EAR will change when superficial velocity alters, so that the effect of superficial velocity and/or EAR on combustion behaviors cannot be examined under a specific condition. When stage combustion is executed, one can discuss the effect of EAR under a certain specific superficial velocity, but the flow rate of secondary air and EAR are dependent. In order to investigate the effect of excess air ratio on the combustion behavior of a fluidized combustion system, the flue gas recirculation was adapted by the author in 2007. We can maintain a fixed flow rate of primary gas or secondary gas and change excess oxygen as an independent variable by adjusting the recirculated flue gas appropriately. In another word, we can investigate the effect of excess oxygen on the combustion behavior at a certain primary gas flow, or at a certain hydrodynamics conditions. This technique can be used at a lower turndown ratio to maintain the residual oxygen in the flue gas at a certain value. All the experiments were conducted in a pilot scale fluidized bed combustor. The fluidized bed combustor can be divided into four parts, i.e., windbox, distributor, combustion chamber, and freeboard. The combustion chamber with a cross-section of 0.8 m × 0.4 m was constructed of 6 mm carbon steel lined with 150 mm refractory to reduce heat loss. Above the combustion chamber, the freeboard is 0.64 m in inner diameter. A total of 27 tuyeres with orifices of 5 and 3 mm inside diameters mounted on a 6 mm stainless-steel plate were used as the gas distributor with an open-area-ratio of 0.52%. The Primary gas and secondary gas were fixed at 3 Nm3/min and 1 Nm3/min respectively. The bed temperature was controlled by three heat transfer tubes inserted into the bubbling bed zone. The experimental data shows that bed temperature, CO and NO emissions increase with the stoichiometric oxygen of the primary gas. NO emissions decrease with the stoichiometric oxygen of the primary. Compared with part of primary air substituted with nitrogen, a lower NO emission can be obtained while flue gas recirculation applies as part of primary air.

Keywords: fluidized bed combustion, flue gas circulation, NO emission, recycle

Procedia PDF Downloads 178
4058 Biosynthesis of Silver Nanoparticles Using Zataria multiflora Extract, and Study of Antibacterial Effects on UTI Bacteria (MDR)

Authors: Mohammad Hossein Pazandeh, Monir Doudi, Sona Rostampour Yasouri

Abstract:

Irregular consumption of current antibiotic makes increases of antibiotic resistance between urin pathogens on all worlds. This study selected based on this great community problem. The aim of this study was the biosynthesis of silver nanoparticles from Zataria multiflora extract and then to investigate its antibacterial effect on gram-negative bacilli common in Urinary Tract Infections (UTI) and MDR. The plant used in the present research was Zataria multiflora whose extract was prepared through Soxhlet extraction method. Green synthesis condition of silver nanoparticles was investigated in terms of three parameters including the extract amount, concentration of silver nitrate salt, and temperature. The seizes of nanoparticles were determined by Zetasizer. In order to identify synthesized silver nanoparticles Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD) methods were used. For evaluating the antibacterial effects of nanoparticles synthesized through biological method different concentrations of silver nanoparticles were studied on 140 cases of Muliple Drug Resistance (MDR) bacteria strains Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, Proteus vulgaris,Citrobacter freundii, Acinetobacter bumanii and Pseudomonas aeruginosa, (each genus of bacteria, 20 samples), which all were MDR and cause urinary tract infections , for identification of bacteria were used of Polymerase Chain Reaction (PCR) test and laboratory methods (Agar well diffusion and Microdilution methods) to assess their sensitivity to Nanoparticles. The data were analyzed using SPSS software by nonparametric Kruskal-Wallis and Mann-Whitney tests. Significant results were found about the effects of silver nitrate concentration, different amounts of Zataria multiflora extract, and temperature on nanoparticles; that is, by increasing the concentration of silver nitrate, extract amount, and temperature, the sizes of synthesized nanoparticles declined. However, the effect of above mentioned factors on particles diffusion index was not significant. Based on the TEM results, particles were mainly spherical shape with a diameter range of 25 to 50 nm. The results of XRD Analysis indicated the formation of Nanostructures and Nanocrystals of silver.. The obtained results of antibacterial effects of different concentrations of silver nanoparticles on according to agar well diffusion and microdilution method, biologically synthesized nanoparticles showed 1000 mg /ml highest and lowest mean inhibition zone diameter in E.coli , Acinetobacter bumanii 23 and 15mm, respectively. MIC was observed for all of bacteria 125mg/ml and for Acinetobacter bumanii 250mg/ml.Comparing the growth inhibitory effect of chemically synthesized Nanoparticles and biologically synthesized Nanoparticles showed that in the chemical method the highest growth inhibition belonged to the concentration of 62.5 mg /ml. The inhibitory effect on the growth all of bacteria causes of urine infection and MDR was observed and by increasing silver ion concentration in Nanoparticles, antibacterial activity increased. Generally, the biological synthesis can be considered an efficient way not only in making Nanoparticles but also for having anti-bacterial properties. It is more biocompatible and may be possess less toxicity than the Nanoparticles synthesized chemically.

Keywords: biosynthesis, MDR bacteria, silver nanoparticles, UTI

Procedia PDF Downloads 44
4057 Biosorption Kinetics, Isotherms, and Thermodynamic Studies of Copper (II) on Spirogyra sp.

Authors: Diwan Singh

Abstract:

The ability of non-living Spirogyra sp. biomass for biosorption of copper(II) ions from aqueous solutions was explored. The effect of contact time, pH, initial copper ion concentration, biosorbent dosage and temperature were investigated in batch experiments. Both the Freundlich and Langmuir Isotherms were found applicable on the experimental data (R2>0.98). Qmax obtained from the Langmuir Isotherms was found to be 28.7 mg/g of biomass. The values of Gibbs free energy (ΔGº) and enthalpy change (ΔHº) suggest that the sorption is spontaneous and endothermic at 20ºC-40ºC.

Keywords: biosorption, Spirogyra sp., contact time, pH, dose

Procedia PDF Downloads 421