Search results for: precipitation concentration index (PCI)
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8709

Search results for: precipitation concentration index (PCI)

7779 Mercaptopropionic Acid (MPA) Modifying Chitosan-Gold Nano Composite for γ-Aminobutyric Acid Analysis Using Raman Scattering

Authors: Bingjie Wang, Su-Yeon Kwon, Ik-Joong Kang

Abstract:

The goal of this experiment is to develop a sensor that can quickly check the concentration by using the nanoparticles made by chitosan and gold. Using chitosan nanoparticles crosslinking with sodium tripolyphosphate(TPP) is the first step to form the chitosan nanoparticles, which would be covered with the gold sequentially. The size of the fabricated product was around 100nm. Based on the method that the sulfur end of the MPA linked to gold can form the very strong S–Au bond, and the carboxyl group, the other end of the MPA, can easily absorb the GABA. As for the GABA, what is the primary inhibitory neurotransmitter in the mammalian central nervous system in the human body. It plays such significant role in reducing neuronal excitability pass through the nervous system. A Surface-enhanced Raman Scattering (SERS) as the principle for enhancing Raman scattering by molecules adsorbed on rough metal surfaces or by nanostructures is used to detect the concentration change of γ-Aminobutyric Acid (GABA). When the system is formed, it generated SERS, which made a clear difference in the intensity of Raman scattering within the range of GABA concentration. So it is obtained from the experiment that the calibration curve according to the GABA concentration relevant with the SERS scattering. In this study, DLS, SEM, FT-IR, UV, SERS were used to analyze the products to obtain the conclusion.

Keywords: mercaptopropionic acid, chitosan-gold nanoshell, γ-aminobutyric acid, surface-enhanced raman scattering

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7778 Concentrations of Leptin, C-Peptide and Insulin in Cord Blood as Fetal Origins of Insulin Resistance and Their Effect on the Birth Weight of the Newborn

Authors: R. P. Hewawasam, M. H. A. D. de Silva, M. A. G. Iresha

Abstract:

Obesity is associated with an increased risk of developing insulin resistance. Insulin resistance often progresses to type-2 diabetes mellitus and is linked to a wide variety of other pathophysiological features including hypertension, hyperlipidemia, atherosclerosis (metabolic syndrome) and polycystic ovarian syndrome. Macrosomia is common in infants born to not only women with gestational diabetes mellitus but also non-diabetic obese women. During the past two decades, obesity in children and adolescents has risen significantly in Asian populations including Sri Lanka. There is increasing evidence to believe that infants who are born large for gestational age (LGA) are more likely to be obese in childhood. It is also established from previous studies that Asian populations have higher percentage body fat at a lower body mass index compared to Caucasians. High leptin levels in cord blood have been reported to correlate with fetal adiposity at birth. Previous studies have also shown that cord blood C-peptide and insulin levels are significantly and positively correlated with birth weight. Therefore, the objective of this preliminary study was to determine the relationship between parameters of fetal insulin resistance such as leptin, C-peptide and insulin and the birth weight of the newborn in a study population in Southern Sri Lanka. Umbilical cord blood was collected from 90 newborns and the concentration of insulin, leptin, and C-peptide were measured by ELISA technique. Birth weight, length, occipital frontal, chest, hip and calf circumferences of newborns were measured and characteristics of the mother such as age, height, weight before pregnancy and weight gain were collected. The relationship between insulin, leptin, C-peptide, and anthropometrics were assessed by Pearson’s correlation while the Mann-Whitney U test was used to assess the differences in cord blood leptin, C-peptide, and insulin levels between groups. A significant difference (p < 0.001) was observed between the insulin levels of infants born LGA (18.73 ± 0.64 µlU/ml) and AGA (13.08 ± 0.43 µlU/ml). Consistently, A significant increase in concentration (p < 0.001) was observed in C-peptide levels of infants born LGA (9.32 ± 0.77 ng/ml) compared to AGA (5.44 ± 0.19 ng/ml). Cord blood leptin concentration of LGA infants (12.67 ng/mL ± 1.62) was significantly higher (p < 0.001) compared to the AGA infants (7.10 ng/mL ± 0.97). Significant positive correlations (p < 0.05) were observed among cord leptin levels and the birth weight, pre-pregnancy maternal weight and BMI between the infants of AGA and LGA. Consistently, a significant positive correlation (p < 0.05) was observed between the birth weight and the C peptide concentration. Significantly high concentrations of leptin, C-peptide and insulin levels in the cord blood of LGA infants suggest that they may be involved in regulating fetal growth. Although previous studies suggest comparatively high levels of body fat in the Asian population, values obtained in this study are not significantly different from values previously reported from Caucasian populations. According to this preliminary study, maternal pre-pregnancy BMI and weight may contribute as significant indicators of cord blood parameters of insulin resistance and possibly the birth weight of the newborn.

Keywords: large for gestational age, leptin, C-peptide, insulin

Procedia PDF Downloads 147
7777 Effects of Reclamation on Seasonal Dynamic of Carbon, Nitrogen and Phosphorus Stoichiometry in Suaeda salsa

Authors: Yajun Qiao, Yaner Yan, Ning Li, Shuqing An

Abstract:

In order to relieve the pressure on a land resource from a huge population, reclamation has occurred in many coastal wetlands. Plants can maintain their elemental composition within normal limits despite the variations of external conditions. Reclamation may affect carbon (C), nitrogen (N) and phosphorus (P) stoichiometry in the plant to some extent by altering physical and chemical properties of soil in a coastal wetland. We reported the seasonal dynamic of C, N and P stoichiometry in root, stem and leaf of Suaeda salsa (L.) Pall. and in soil between reclamation plots and natural plots. Our results of three-way ANOVA indicated that sampling season always had significant effect on C, N, P concentrations and their ratios; organ had no significant effect on N, P concentration and N:P; plot type had no significant effect on N concentration and C:N. Sampling season explained the most variability of tissue N and P contents, C:N, C:P and N:P, while it’s organ for C using the restricted maximum likelihood (REML) method. By independent sample T-test, we found that reclamation affect more on C, N and P stoichiometry of stem than that of root or leaf on the whole. While there was no difference between reclamation plots and natural plots for soil in four seasons. For three organs, C concentration had peak values in autumn and minimum values in spring while N concentration had peak values in spring and minimum values in autumn. For P concentration, three organs all had peak values in spring; however, the root had minimum value in winter, the stem had that in autumn, and leaf had that in summer. The seasonal dynamic of C, N and P stoichiometry in a leaf of Suaeda salsa were much steadier than that in root or stem under the drive of reclamation.

Keywords: nitrogen, phosphorus, reclamation, seasonal dynamic, Suaeda salsa

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7776 Nonparametric Truncated Spline Regression Model on the Data of Human Development Index in Indonesia

Authors: Kornelius Ronald Demu, Dewi Retno Sari Saputro, Purnami Widyaningsih

Abstract:

Human Development Index (HDI) is a standard measurement for a country's human development. Several factors may have influenced it, such as life expectancy, gross domestic product (GDP) based on the province's annual expenditure, the number of poor people, and the percentage of an illiterate people. The scatter plot between HDI and the influenced factors show that the plot does not follow a specific pattern or form. Therefore, the HDI's data in Indonesia can be applied with a nonparametric regression model. The estimation of the regression curve in the nonparametric regression model is flexible because it follows the shape of the data pattern. One of the nonparametric regression's method is a truncated spline. Truncated spline regression is one of the nonparametric approach, which is a modification of the segmented polynomial functions. The estimator of a truncated spline regression model was affected by the selection of the optimal knots point. Knot points is a focus point of spline truncated functions. The optimal knots point was determined by the minimum value of generalized cross validation (GCV). In this article were applied the data of Human Development Index with a truncated spline nonparametric regression model. The results of this research were obtained the best-truncated spline regression model to the HDI's data in Indonesia with the combination of optimal knots point 5-5-5-4. Life expectancy and the percentage of an illiterate people were the significant factors depend to the HDI in Indonesia. The coefficient of determination is 94.54%. This means the regression model is good enough to applied on the data of HDI in Indonesia.

Keywords: generalized cross validation (GCV), Human Development Index (HDI), knots point, nonparametric regression, truncated spline

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7775 Hydrological Response of the Glacierised Catchment: Himalayan Perspective

Authors: Sonu Khanal, Mandira Shrestha

Abstract:

Snow and Glaciers are the largest dependable reserved sources of water for the river system originating from the Himalayas so an accurate estimate of the volume of water contained in the snowpack and the rate of release of water from snow and glaciers are, therefore, needed for efficient management of the water resources. This research assess the fusion of energy exchanges between the snowpack, air above and soil below according to mass and energy balance which makes it apposite than the models using simple temperature index for the snow and glacier melt computation. UEBGrid a Distributed energy based model is used to calculate the melt which is then routed by Geo-SFM. The model robustness is maintained by incorporating the albedo generated from the Landsat-7 ETM images on a seasonal basis for the year 2002-2003 and substrate map derived from TM. The Substrate file includes predominantly the 4 major thematic layers viz Snow, clean ice, Glaciers and Barren land. This approach makes use of CPC RFE-2 and MERRA gridded data sets as the source of precipitation and climatic variables. The subsequent model run for the year between 2002-2008 shows a total annual melt of 17.15 meter is generate from the Marshyangdi Basin of which 71% is contributed by the glaciers , 18% by the rain and rest being from the snow melt. The albedo file is decisive in governing the melt dynamics as 30% increase in the generated surface albedo results in the 10% decrease in the simulated discharge. The melt routed with the land cover and soil variables using Geo-SFM shows Nash-Sutcliffe Efficiency of 0.60 with observed discharge for the study period.

Keywords: Glacier, Glacier melt, Snowmelt, Energy balance

Procedia PDF Downloads 444
7774 Effects of Temperature and Enzyme Concentration on Quality of Pineapple and Pawpaw Blended Juice

Authors: Ndidi F. Amulu, Calistus N. Ude, Patrick E. Amulu, Nneka N. Uchegbu

Abstract:

The effects of temperature and enzyme concentration on the quality of mixed pineapple and pawpaw blended fruits juice were studied. Extracts of the two fruit juices were separately treated at 70  for 15 min each so as to inactivate micro-organisms. They were analyzed and blended in different proportions of 70% pawpaw and 30% pineapple, 60% pawpaw and 40% pineapple, 50% pineapple and 50% pawpaw, 40% pawpaw and 60% pineapple. The characterization of the fresh pawpaw and pineapple juice before blending showed that the juices have good quality. The high water content of the product may have affected the viscosity, vitamin C content and total soluble solid of the blended juice to be low. The effects of the process parameters on the quality showed that better quality of the blended juice can be obtained within the optimum temperature range of (50-70 °C) and enzyme concentration range (0.12-0.18 w/v). The ratio of mix 60% pineapple juice: 40% pawpaw juice has better quality. This showed that pawpaw and pineapple juices can blend effectively to produce a quality juice.

Keywords: clarification, pawpaw, pineapple, viscosity, vitamin C

Procedia PDF Downloads 294
7773 Selection of Lead Mobilizing Bacteria from Contaminated Soils and Their Potential in Promoting Plant Growth through Plant Growth Promoting Activity

Authors: Maria Manzoor, Iram Gul, Muhammad Arshad

Abstract:

Bacterial strains were isolated from contaminated soil collected from Rawalpindi and Islamabad. The strains were investigated for lead resistance and their effect on Pb solubility and PGPR activity. Incubation experiments were carried for inoculated and unoculated soil containing different levels of Pb. Results revealed that few stains (BTM-4, BTM-11, BTM-14) were able to tolerate Pb up to 600 mg L-1, whereas five strains (BTM-3, BTM-6, BTM-10, BTM-21 and BTM-24) showed significant increase in solubility of Pb when compared to all other strains and control. The CaCl2 extractable Pb was increased by 13.6, 6.8, 4.4 and 2.4 folds compared to un-inoculated control soil at increased soil Pb concentration (500, 1000, 1500 and 200 mg kg-1, respectively). The selected bacterial strains (11) were further investigated for plant growth promotion activity through PGPR assays including. Germination and root elongation assays were also conducted under elevated metal concentration in controlled conditions to elucidate the effects of microbial strains upon plant growth and development. The results showed that all the strains tested in this study, produced significantly varying concentrations of IAA, siderophores and gibberellic acid along with ability to phosphorus solubilization index (PSI). The results of germination and root elongation assay further confirmed the beneficial role of the microbial strains in elevating metal stress through PGPR activity. Among all tested strains, BTM-10 significantly improved plant growth. 1.3 and 2.7 folds increase in root and shoot length was observed when compared to control. Which may be attributed to presence of important plant growth promoting enzymes (IAA 74.6 μg/ml; GA 19.23 μg/ml; Sidrophore units 49% and PSI 1.3 cm). The outcome of this study indicates that these Pb tolerant and solubilizing strains may have the potential for plant growth promotion under metal stress and can be used as mediator when coupled with heavy metal hyperaccumulator plants for phytoremediation of Pb contaminated soil.

Keywords: Pb resistant bacteria, Pb mobilizing bacteria, Phytoextraction of Pb, PGPR activity of bacteria

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7772 The Influence of Aerobic Physical Exercise with Different Frequency to Concentration of Vascular Endothelial Growth Factor in Brain Tissue of Wistar Rat

Authors: Rostika Flora, Muhammad Zulkarnain, Syokumawena

Abstract:

Background: Aerobic physical exercises are recommended to keep body fit and healthy although physical exercises themselves can increase body metabolism and oxygen and can lead into tissue hypoxia. Oxygen pressure can serve as Vascular Endhothelial Growth Factor (VEGF) regulator. Hypoxia increases gene expression of VEGF through ascendant regulation of HIF-1. VEGF is involved in regulating angiogenesis process. Aerobic physical exercises can increase the concentration of VEGF in brain and enables angiogenesis process. We have investigated the influence of aerobic physical exercise to the VGEF concentration of wistar rat’s brain. Methods: This was experimental study using post test only control group design. Independent t-test was used as statistical test. The samples were twenty four wistar rat (Rattus Norvegicus) which were divided into four groups: group P1 (control group), group P2 (treatment group with once-a-week exercise), group P3 (treatment group with three time-a-week exercise), and group P4 (treatment group with seven time-a-week exercise). Group P2, P3, and P4 were treated with treadmil with speed of 20 m/minute for 30 minutes. The concentration of VEGF was determined by ELISA. Results: There was a significant increase of VEGF in treatment group compared with control one (<0.05). The maximum increase was found in group P2 (129.02±64.49) and the minimum increase was in group P4 (96.98±11.20). Conclusion: The frequency of aerobic physical exercises influenced the concentration of Vascular Endhothelial Growth Factor (VEGF) of brain tissue of Rattus Norvegicus.

Keywords: brain tissue, hypoxia, physical exercises, vascular endhothelial growth factor

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7771 Immune Disregulation in Inflammatory Skin Diseases with Comorbid Metabolic Disorders

Authors: Roman Khanferyan, Levon Gevorkyan, Ivan Radysh

Abstract:

Skin barrier dysfunction induces multiple inflammatory skin diseases. Epidemiological studies clearly support the link between most dermatological pathologies, immune disorders and metabolic disorders. Among them most common are psoriasis (PS) and Atopic dermatitis (AD). Psoriasis is a chronic immune-mediated inflammatory skin disease that affects 1.5 to 3.0% of the world's population. Comorbid metabolic disorders play an important role in the progression of PS and AD, as well. It is well known that PS, AD and overweight/obesity are associated with common pathophysiological mechanisms of mild chronic inflammation. The goal of the study was to study the immune disturbances in patients with PS, AD and comorbid metabolic disorders. To study the prevalence of comorbidity of PS and AD (data from 1406 patient’s histories of diseases) were analyzed. The severity of the disease is assessed using the PASI index (Psoriasis Area and Severity Index). 59 patients with psoriasis of different localizations of lesions and severity, as well as with different body mass index (BMI), were examined. The determination of the concentration of pro-inflammatory cytokines (IL-6, IL-8, IFNγ, IL-17, L-18 and TNFa) and chemokines (RANTES, IP-10, MCP-1 and Eotaxin) in sera and supernatants of 48h-cultivated peripheral blood mononuclear cell (PBMC) of psoriasis patients and healthy volunteers (36 adults) have been carried out by multiplex assay (Luminex Corporation, USA). It has been demonstrated that 42% of PS patients had comorbidity with different types of atopies. The most common was bronchial asthma and allergic rhinitis. At the same time, the prevalence of AD in PS patients was determined in 8.7% of patients. It has been shown that serum levels of all studied cytokines (IL-6, IL-8, IFNγ, IL-17, L-18 and TNF) in most of the studied patients were higher in PS patients than in those with AD and healthy controls (p<0.05). An in vitro synthesis of the IL-6 and IFNγ by PBMC demonstrated similar results to those determined in blood sera. There was a high correlation between BMI, immune mediators and the concentrations of adipokines and chemokines (p<0.05). The concentrations of Leptin and Resistin in obese psoriatic patients were greater by 28.6% and 17%, respectively, compared to non-obese psoriatic patients. In obese patients with psoriasis the serum levels of adiponectin were decreased up to 1.3-fold. The mean serum RANTES, IP-10, MCP-1, EOTAXIN levels in obese psoriatic patients were decreased by up to 13.1%, 21.9%, 40.4% and 28.2%, respectively. Similar results have been demonstrated in AD patients with comorbid overweight and obesity. Thus, the study demonstrated the important role of cytokines and chemokines dysregulation in inflammatory skin diseases, especially in patients with comorbid obesity and overweight. Metabolic disorders promote the severity of PS and AD, highly increase immune dysregulation, and synthesis of adipokines, which correlates with the production of proinflammatory immune mediators in comorbid obesity and overweight.

Keywords: psoriasis, atopic dermatitis, pro-inflammatory cytokines, chemokines, comorbid obesity

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7770 Experimental and Numerical Studies on Hydrogen Behavior in a Small-Scale Container with Passive Autocatalytic Recombiner

Authors: Kazuyuki Takase, Yoshihisa Hiraki, Gaku Takase, Isamu Kudo

Abstract:

One of the most important issue is to ensure the safety of long-term waste storage containers in which fuel debris and radioactive materials are accumulated. In this case, hydrogen generated by water decomposition by radiation is accumulated in the container for a long period of time, so it is necessary to reduce the concentration of hydrogen in the container. In addition, a condition that any power supplies from the outside of the container are unnecessary is requested. Then, radioactive waste storage containers with the passive autocatalytic recombiner (PAR) would be effective. The radioactive waste storage container with PAR was used for moving the fuel debris of the Three Mile Island Unit 2 to the storage location. However, the effect of PAR is not described in detail. Moreover, the reduction of hydrogen concentration during the long-term storage period was performed by the venting system, which was installed on the top of the container. Therefore, development of a long-term storage container with PAR was started with the aim of safely storing fuel debris picked up at the Fukushima Daiichi Nuclear Power Plant for a long period of time. A fundamental experiment for reducing the concentration of hydrogen which generates in a nuclear waste long-term storage container was carried out using a small-scale container with PAR. Moreover, the circulation flow behavior of hydrogen in the small-scale container resulting from the natural convection by the decay heat was clarified. In addition, preliminary numerical analyses were performed to predict the experimental results regarding the circulation flow behavior and the reduction of hydrogen concentration in the small-scale container. From the results of the present study, the validity of the container with PAR was experimentally confirmed on the reduction of hydrogen concentration. In addition, it was predicted numerically that the circulation flow behavior of hydrogen in the small-scale container is blocked by steam which generates by chemical reaction of hydrogen and oxygen.

Keywords: hydrogen behavior, reduction of concentration, long-term storage container, small-scale, PAR, experiment, analysis

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7769 Insecticidal and Repellent Efficacy of Clove and Lemongrass Oils Against Museum Pest, Lepisma Saccharina (Zygentoma: Lepismatidae)

Authors: Suboohi Nasrin, MHD. Shahid, Abduraheem K.

Abstract:

India is a tropical country, and it is estimated that biological and abiological agents are the major factors in the destruction and deterioration of archival materials like herbarium, paper, cellulose, bookbinding, etc. Silverfish, German Cockroaches, Termites, Booklice, Tobacco beetle and Carpet beetles are the common insect's pests in the museum, which causes deterioration to collections of museum specimens. Among them, silverfish is one of the most notorious pests and primarily responsible for the deterioration of Archival materials. So far, the investigation has been carried to overcome this existing problem as different management strategies such as chemical insecticides, fungicides, herbicides, nematicides, etc., have been applied. Moreover, Synthetic molecules lead to affect the ecological balance, have a detrimental effects on human health, reduce the beneficial microbial flora and fauna, etc. With a view, numbers of chemicals have been banned and advised not to be used due to their long-lasting persistency in soil ecosystem, water and carcinogenic. That’s why the authors used natural products with biocidal activity, cost-effective and eco-friendly approaches. In this study, various concentrations (30, 60 and 90 ml/L) of clove and lemongrass essential oil at different treatment duration (30, 60, 90 and 120-minutes) were investigated to test its properties as a silverfish repellent and insecticidal effect. The result of two ways ANOVA revealed that the mortality was significantly influenced by oil concentration, treatment duration and interaction between two independent factors was also found significant. The mortality rate increased with increasing the oil concentration in clove oil, and 100 % mortality was recorded in 0.9 ml at 120-minute. It was also observed that the treatment duration has the highest effect on the mortality rate of silverfish. The clove oil had the greatest effect on the silverfish in comparison to lemongrass. While in the case of percentage, repellency of adult silverfish was oil concentration and treatment duration-dependent, i.e., increase in concentration and treatment duration resulted in higher repellency percentage. The clove oil was found more effective, showing maximum repellency of 80.00% at 0.9ml/cm2 (highest) concentration, and in lemongrass highest repellency was observed at 33.4% at 0.9 ml/cm2 concentration in the treated area.

Keywords: adult silverfish, oils, oil concentration, treatment duration, mortality (%) and repellency

Procedia PDF Downloads 158
7768 Effect of Acute Ingestion of Ice Water on Blood Pressure in Relation to Body Mass Index

Authors: Savitri Siddanagoudra, Shantala Herlekar, Priya Arjunwadekar

Abstract:

Background: The physiological response to water drinking in healthy subjects is an integrated response with an increase in sympathetic vasoconstrictor activity with induced bradycardia. Obesity is a modern pandemic, implicated in the pathogenesis of cardiovascular disease. In autonomic failure patients, water drinking has been shown the increased high blood pressure and bradycardia. Acute effects of ice water ingestion on blood pressure (BP) in relation to body mass index (BMI) is not addressed in literature. Objectives: Objective of this study is to evaluate BP before and after ingestion of cold water in all the three groups. Methods and Material: 60 healthy subjects between the age group of 18-24 yrs were selected and assigned into 3 groups based on BMI. BMI less than and equal to 25 kg/m2 is selected as Normal BMI group ,between 25- 29 kg/m2 as Overweight and BMI more than and equal to 30 kg/m2 as Obese. Procedure: Basal and after ingestion of 250 ml of cold water (7 0C ± 0.5 0C)BP was recorded in all the 3 groups. Results: Basal and after ice water ingestion BP increased statistically in all 3 groups. Conclusion: On acute ingestion of ice water overweight, obese may have more sympathoexcitaion compared to normal subjects.

Keywords: blood pressure, body mass index, ice water, symathoexcitation

Procedia PDF Downloads 153
7767 Assessment of Trace Metal Concentration of Soils Contaminated with Carbide in Abraka, Delta State, Nigeria

Authors: O.M. Agbogidi, I.M. Onochie

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An investigation was carried out on trace metal concentration of soils contaminated with carbide in Abraka, Delta State, Nigeria in 2014 with a view to providing baseline formation on their status relative to the control plants and to the tolerable limits recommended by World standard bodies including WHO and FAO. The metals were analyzed using the Atomic Absorption Spectrophotometer which showed an elevated level when compared with the control plots. High level of metals including Fe, Pb, Zn, Cu, Cd, Ni, Cr and arsenic were recorded and these values were significantly different (P<0.05) from values obtained from the control plots. These results are indicative of the fact that carbide polluted soil had higher level of trace metals and because these metals are non-biodegradable elements in the ecosystem, a rise to their lethal levels in food chains is envisaged due to the interdependency of plants and animals stemming from soil-water organisms interrelationship.

Keywords: bio-concentration, carbide contaminated soils, heavy metals, trace metals

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7766 Modelling Interactions between Saturated and Unsaturated Zones by Hydrus 1D, Plain of Kairouan, Central Tunisia

Authors: Mariem Saadi, Sabri Kanzari, Adel Zghibi

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In semi-arid areas like the Kairouan region, the constant irrigation with saline water and the overuse of groundwater resources, soils and aquifers salinization has become an increasing concern. In this study, a methodology has been developed to evaluate the groundwater contamination risk based on the unsaturated zone hydraulic properties. Two soil profiles with different ranges of salinity, one located in the north of the plain and another one in the south of plain (each 30 m deep) and both characterized by direct recharge of the aquifer were chosen. Simulations were conducted with Hydrus-1D code using measured precipitation data for the period 1998-2003 and calculated evapotranspiration for both chosen profiles. Four combinations of initial conditions of water content and salt concentration were used for the simulation process in order to find the best match between simulated and measured values. The success of the calibration of Hydrus-1D allowed the investigation of some scenarios in order to assess the contamination risk under different natural conditions. The aquifer risk contamination is related to the natural conditions where it increased while facing climate change and temperature increase and decreased in the presence of a clay layer in the unsaturated zone. Hydrus-1D was a useful tool to predict the groundwater level and quality in the case of a direct recharge and in the absence of any information related to the soil layers except for the texture.

Keywords: Hydrus-1D, Kairouan, salinization, semi-arid region, solute transport, unsaturated zone

Procedia PDF Downloads 164
7765 Evaluating the Accuracy of Biologically Relevant Variables Generated by ClimateAP

Authors: Jing Jiang, Wenhuan XU, Lei Zhang, Shiyi Zhang, Tongli Wang

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Climate data quality significantly affects the reliability of ecological modeling. In the Asia Pacific (AP) region, low-quality climate data hinders ecological modeling. ClimateAP, a software developed in 2017, generates high-quality climate data for the AP region, benefiting researchers in forestry and agriculture. However, its adoption remains limited. This study aims to confirm the validity of biologically relevant variable data generated by ClimateAP during the normal climate period through comparison with the currently available gridded data. Climate data from 2,366 weather stations were used to evaluate the prediction accuracy of ClimateAP in comparison with the commonly used gridded data from WorldClim1.4. Univariate regressions were applied to 48 monthly biologically relevant variables, and the relationship between the observational data and the predictions made by ClimateAP and WorldClim was evaluated using Adjusted R-Squared and Root Mean Squared Error (RMSE). Locations were categorized into mountainous and flat landforms, considering elevation, slope, ruggedness, and Topographic Position Index. Univariate regressions were then applied to all biologically relevant variables for each landform category. Random Forest (RF) models were implemented for the climatic niche modeling of Cunninghamia lanceolata. A comparative analysis of the prediction accuracies of RF models constructed with distinct climate data sources was conducted to evaluate their relative effectiveness. Biologically relevant variables were obtained from three unpublished Chinese meteorological datasets. ClimateAPv3.0 and WorldClim predictions were obtained from weather station coordinates and WorldClim1.4 rasters, respectively, for the normal climate period of 1961-1990. Occurrence data for Cunninghamia lanceolata came from integrated biodiversity databases with 3,745 unique points. ClimateAP explains a minimum of 94.74%, 97.77%, 96.89%, and 94.40% of monthly maximum, minimum, average temperature, and precipitation variances, respectively. It outperforms WorldClim in 37 biologically relevant variables with lower RMSE values. ClimateAP achieves higher R-squared values for the 12 monthly minimum temperature variables and consistently higher Adjusted R-squared values across all landforms for precipitation. ClimateAP's temperature data yields lower Adjusted R-squared values than gridded data in high-elevation, rugged, and mountainous areas but achieves higher values in mid-slope drainages, plains, open slopes, and upper slopes. Using ClimateAP improves the prediction accuracy of tree occurrence from 77.90% to 82.77%. The biologically relevant climate data produced by ClimateAP is validated based on evaluations using observations from weather stations. The use of ClimateAP leads to an improvement in data quality, especially in non-mountainous regions. The results also suggest that using biologically relevant variables generated by ClimateAP can slightly enhance climatic niche modeling for tree species, offering a better understanding of tree species adaptation and resilience compared to using gridded data.

Keywords: climate data validation, data quality, Asia pacific climate, climatic niche modeling, random forest models, tree species

Procedia PDF Downloads 55
7764 A Preliminary Survey of Mosses, in Galahitiya, Meneripitiya Grama Niladhari Division in Rathnapura District of Sri Lanka

Authors: B. W. U. Deepashika

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Rathnapura is located in the south-western part of Sri Lanka, the so-called wet zone. This area receives rainfall mainly from south-west monsoons from May to September. During the remaining months of the year, there is also a considerable precipitation due to convective rains. The average annual precipitation is about 4,000 to 5,000 mm. The average temperature varies from 24 to 35 °C, and there are high humidity levels. Mosses are one of the important groups of the flora of this region and they are very sensitive to climatic changes. Proper exploration and systematic studies on mosses in many parts of the country have not yet been carried out. Therefore, launching a study on the bryophyte flora of the country has become very important. The preliminary survey of bryophytes was carried out in Galahitiya, Meneripitiya Grama Niladari Division, located in Ratnapura district, in Sabaragamuwa province which is situated 20 kilometres away from Rathnapura. Its geographical coordinates are 6° 35' North, 80° 35' East. Samples were collected from different habitats including home gardens, near the wells, small forest patch, tea land, near the stream, from non-cemented wall, from cement wall, and from ditches. Two small quadrates (1ˣ 1m2) were used in each study site. Taxa were identified up to the generic level using taxonomic keys produced for different geographic regions of the world. In the present survey, a total of 09 mosses belonging to seven families were identified to their generic level. They are Family-Bryaceae (3) (Bryum sp, Brachymenium sp, Pohlia sp), Fissidentaceae (1) (Fissidens sp), Leucobryaceae (1) (Octoblepharum sp), Calymperaceae (1) (Calymperes sp), Polytrichaceae (1) (Pogonatum sp), Pterobryaceae (1) (Pterobryopsis sp), Sematophyllaceae (1) (Taxithelium sp).

Keywords: mosses, wet zone, Sabaragamuwa province, Sri Lanka

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7763 Evaluation of Phthalates Contents and Their Health Effects in Consumed Sachet Water Brands in Delta State, Nigeria

Authors: Edjere Oghenekohwiroro, Asibor Irabor Godwin, Uwem Bassey

Abstract:

This paper determines the presence and levels of phthalates in sachet and borehole water source in some parts of Delta State, Nigeria. Sachet and borehole water samples were collected from seven different water packaging facilities and level of phthalates determined using GC-MS instrumentation. Phthalates concentration in borehole samples varied from 0.00-0.01 (DMP), 0.06-0.20 (DEP), 0.10-0.98 (DBP), 0.21-0.36 (BEHP), 0.01-0.03 (DnOP) µg/L and (BBP) was not detectable; while sachet water varied from 0.03-0.95 (DMP), 0.16-12.45 (DEP), 0.57-3.38 (DBP), 0.00-0.03 (BBP), 0.08-0.31 (BEHP) and 0-0.03 (DnOP) µg/L. Phthalates concentration in the sachet water was higher than that of the corresponding boreholes sources and also showed significant difference (p < 0.05) between the two. Sources of these phthalate esters were the interaction between water molecules and plastic storage facilities. Although concentration of all phthalate esters analyzed were lower than the threshold limit value(TLV), over time storage of water samples in this medium can lead to substantial increase with negative effects on individuals consuming them.

Keywords: phthalate esters, borehole, sachet water, sample extraction, gas chromatography, GC-MS

Procedia PDF Downloads 236
7762 Pollution Assessment and Potential Ecological Risk of Some Traces Metals in the Surface Sediments of the Gulf of Tunis, North Tunisia

Authors: Haïfa Ben Mna, Ayed Added

Abstract:

To evaluate the trace metals contamination status in the Gulf of Tunis, forty one sediment samples were analyzed using different approaches. According to certain contamination and ecological risk indices (Contamination Factor, Geoaccumulation index and Ecological risk index), Hg has the highest contamination level while pollution by Ni, Pb, Cd and Cr was absent. The highest concentrations of trace metals were found in sediments collected from the offshore and coastal areas located opposite the main exchange points with the gulf particularly, the Mejerda and Meliane Rivers, the Khalij Channel, Ghar El Melh and El Malah lagoons, Tunis Lake and Sebkhat Ariana. However, further ecological indices (Potential ecological risk index, Toxic unit and Mean effect-range median quotient) and comparison with sediment quality guidelines suggest that in addition to Mercury, Cr, Pb and Ni concentrations are detrimental to biota in both the offshore and areas near to the exchange points with the gulf. Moreover, in these areas the results from sequential extraction and individual contamination factor calculation pointed to the mobility and bioavailability of Cr, Pb and Ni.

Keywords: sediment, trace metals, contamination assessment, ecological risk, Tunis gulf

Procedia PDF Downloads 72
7761 Estimating Algae Concentration Based on Deep Learning from Satellite Observation in Korea

Authors: Heewon Jeong, Seongpyo Kim, Joon Ha Kim

Abstract:

Over the last few tens of years, the coastal regions of Korea have experienced red tide algal blooms, which are harmful and toxic to both humans and marine organisms due to their potential threat. It was accelerated owing to eutrophication by human activities, certain oceanic processes, and climate change. Previous studies have tried to monitoring and predicting the algae concentration of the ocean with the bio-optical algorithms applied to color images of the satellite. However, the accurate estimation of algal blooms remains problems to challenges because of the complexity of coastal waters. Therefore, this study suggests a new method to identify the concentration of red tide algal bloom from images of geostationary ocean color imager (GOCI) which are representing the water environment of the sea in Korea. The method employed GOCI images, which took the water leaving radiances centered at 443nm, 490nm and 660nm respectively, as well as observed weather data (i.e., humidity, temperature and atmospheric pressure) for the database to apply optical characteristics of algae and train deep learning algorithm. Convolution neural network (CNN) was used to extract the significant features from the images. And then artificial neural network (ANN) was used to estimate the concentration of algae from the extracted features. For training of the deep learning model, backpropagation learning strategy is developed. The established methods were tested and compared with the performances of GOCI data processing system (GDPS), which is based on standard image processing algorithms and optical algorithms. The model had better performance to estimate algae concentration than the GDPS which is impossible to estimate greater than 5mg/m³. Thus, deep learning model trained successfully to assess algae concentration in spite of the complexity of water environment. Furthermore, the results of this system and methodology can be used to improve the performances of remote sensing. Acknowledgement: This work was supported by the 'Climate Technology Development and Application' research project (#K07731) through a grant provided by GIST in 2017.

Keywords: deep learning, algae concentration, remote sensing, satellite

Procedia PDF Downloads 175
7760 The Hydro-Geology and Drinking Water Quality of Ikogosi Warm Spring in South West Nigeria

Authors: Ikudayisi Akinola, Adeyemo Folasade, Adeyemo Josiah

Abstract:

This study focuses on the hydro-geology and chemistry of Ikogosi Warm Spring in South West Nigeria. Ikogosi warm spring is a global tourist attraction because it has both warm and cold spring sources. Water samples from the cold spring, warm spring and the meeting point were collected, analyzed and the result shows close similarity in temperature, hydrogen iron concentration (pH), alkalinity, hardness, Calcium, Magnesium, Sodium, Iron, total dissolved solid and heavy metals. The measured parameters in the water samples are within World Health Organisation standards for fresh water. The study of the geology of the warm spring reveals that the study area is underlain by a group of slightly migmatised to non-migmatised paraschists and meta-igneous rocks. The concentration levels of selected heavy metals, (Copper, Cadmium, Zinc, Arsenic and Cromium) were determined in the water (ppm) samples. Chromium had the highest concentration value of 1.52ppm (an average of 49.67%) and Cadmium had the lowest concentration with value of 0.15ppm (an average of 4.89%). Comparison of these results showed that, their mean levels are within the standard values obtained in Nigeria. It can be concluded that both warm and spring water are safe for drinking.

Keywords: cold spring, Ikogosi, melting point, warm spring, water samples

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7759 Characteristics of Ozone Generated from Dielectric Barrier Discharge Plasma Actuators

Authors: R. Osada, S. Ogata, T. Segawa

Abstract:

Dielectric barrier discharge plasma actuators (DBD-PAs) have been developed for active flow control devices. However, it is necessary to reduce ozone produced by DBD toward practical applications using DBD-PAs. In this study, variations of ozone concentration, flow velocity, power consumption were investigated by changing exposed electrodes of DBD-PAs. Two exposed electrode prototypes were prepared: span-type with exposed electrode width of 0.1 mm, and normal-type with width of 5 mm. It was found that span-type shows lower power consumption and higher flow velocity than that of normal-type at Vp-p = 4.0-6.0 kV. Ozone concentration of span-type higher than normal-type at Vp-p = 4.0-8.0 kV. In addition, it was confirmed that catalyst located in downstream from the exposed electrode can reduce ozone concentration between 18 and 42% without affecting the induced flow.

Keywords: dielectric barrier discharge plasma actuators, ozone diffusion, PIV measurement, power consumption

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7758 Effect of Particles Size and Volume Fraction Concentration on the Thermal Conductivity and Thermal Diffusivity of Al2O3 Nanofluids Measured Using Transient Hot–Wire Laser Beam Deflection Technique

Authors: W. Mahmood Mat Yunus, Faris Mohammed Ali, Zainal Abidin Talib

Abstract:

In this study we present new data for the thermal conductivity enhancement in four nanofluids containing 11, 25, 50, 63 nm diameter aluminum oxide (Al2O3) nanoparticles in distilled water. The nanofluids were prepared using single step method (i.e. by dispersing nanoparticle directly in base fluid) which was gathered in ultrasonic device for approximately 7 hours. The transient hot-wire laser beam displacement technique was used to measure the thermal conductivity and thermal diffusivity of the prepared nanofluids. The thermal conductivity and thermal diffusivity were obtained by fitting the experimental data to the numerical data simulated for aluminum oxide in distilled water. The results show that the thermal conductivity and thermal diffusivity of nanofluids increases in non-linear behavior as the particle size increases. While, the thermal conductivity and thermal diffusivity of Al2O3 nanofluids was observed increasing linearly with concentration as the volume fraction concentration increases. We believe that the interfacial layer between solid/fluid is the main factor for the enhancement of thermal conductivity and thermal diffusivity of Al2O3 nanofluids in the present work.

Keywords: transient hot wire-laser beam technique, Al2O3 nanofluid, particle size, volume fraction concentration

Procedia PDF Downloads 536
7757 Biophysical Modeling of Anisotropic Brain Tumor Growth

Authors: Mutaz Dwairy

Abstract:

Solid tumors have high interstitial fluid pressure (IFP), high mechanical stress, and low oxygen levels. Solid stresses may induce apoptosis, stimulate the invasiveness and metastasis of cancer cells, and lower their proliferation rate, while oxygen concentration may affect the response of cancer cells to treatment. Although tumors grow in a nonhomogeneous environment, many existing theoretical models assume homogeneous growth and tissue has uniform mechanical properties. For example, the brain consists of three primary materials: white matter, gray matter, and cerebrospinal fluid (CSF). Therefore, tissue inhomogeneity should be considered in the analysis. This study established a physical model based on convection-diffusion equations and continuum mechanics principles. The model considers the geometrical inhomogeneity of the brain by including the three different matters in the analysis: white matter, gray matter, and CSF. The model also considers fluid-solid interaction and explicitly describes the effect of mechanical factors, e.g., solid stresses and IFP, chemical factors, e.g., oxygen concentration, and biological factors, e.g., cancer cell concentration, on growing tumors. In this article, we applied the model on a brain tumor positioned within the white matter, considering the brain inhomogeneity to estimate solid stresses, IFP, the cancer cell concentration, oxygen concentration, and the deformation of the tissues within the neoplasm and the surrounding. Tumor size was estimated at different time points. This model might be clinically crucial for cancer detection and treatment planning by measuring mechanical stresses, IFP, and oxygen levels in the tissue.

Keywords: biomechanical model, interstitial fluid pressure, solid stress, tumor microenvironment

Procedia PDF Downloads 30
7756 Seasonal Variation of Polycyclic Aromatic Hydrocarbons Associated with PM10 in Győr, Hungary

Authors: Andrea Szabó Nagy, János Szabó, Zsófia Csanádi, József Erdős

Abstract:

The main objective of this study was to assess the seasonal variation of atmospheric polycyclic aromatic hydrocarbon (PAH) concentrations associated with PM10 in an urban site of Győr, Hungary. A total of 112 PM10 aerosol samples were collected in the years of 2012 and 2013 and analyzed for PAHs by gas chromatography method. The total PAH concentrations (sum of the concentrations of 19 individual PAH compounds) ranged from 0.19 to 70.16 ng/m3 with the mean value of 12.29 ng/m3. Higher concentrations of both total PAHs and benzo[a]pyrene (BaP) were detected in samples collected in the heating seasons. Using BaP-equivalent potency index on the carcinogenic PAH concentration data, the local population appears to be exposed to significantly higher cancer risk in the heating seasons. However, the comparison of the BaP and total PAH concentrations observed for Győr with other cities it was found that the PAH levels in Győr generally corresponded to the EU average.

Keywords: air quality, benzo[a]pyrene, PAHs, polycyclic aromatic hydrocarbons

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7755 Effect of Supplemental Bacterial Phytase at Different Dietary Levels of Phosphorus on Tibial Bone Characteristics and Body Weight Gain in Broilers

Authors: Saqib Saleem Abdullah, Saima Masood, Hafsa Zaneb, Shela Gul Bokhari, Muti Ur Rehman, Jamil Akbar

Abstract:

A 5- weeks feeding trial was carried out to determine the effectiveness of Bacterial Phytase (Phyzyme®) in broilers, at different dietary levels of Phosphorous. 140 d-old broilers (Hubbard) were randomly divided into 4 groups (n=4). Birds were fed corn-based basal diet or the same diet supplemented with 3 different levels of non Phytate Phosphorous (NPP) (0.45 %, 0.30 % and 0.15 %). Furthermore, the diets were supplemented with bacterial Phytase. Birds were fed ad libitum and kept under thermo neutral conditions. The parameters studied were; body weight gain (BWG), tibial bone characteristics (TBC), serum Calcium (Ca), Phosphorus (P) and Alkaline Phosphatase (AP) levels and tibia ash percentage (TAP). BWG of the broilers was calculated at weekly interval and remaining parameters were calculated after slaughtering the birds at 35thday. Results suggested that Phytase supplementation at 0.30% NPP (Non Phytate Phosphorus + Bacterial Phytase) increased (P < 0.05) the BWG, bone length, bone weight, tibiotarsal index, medullary canal diameter and diaphysis diameter however, rubosticity index was reduced to minimum (P < 0.05) at this dietary level of phosphorous when compared with other groups. Maximum (P < 0.05) rubosticity index was observed in control group with 0% Phytase. Furthermore, Phytase addition at 0.30 % NPP also improved (P < 0.05) Ca, P and AP levels in the blood. Phytase supplementation at lower phosphorus level (0.30%NPP) improved BWG and TBC including bone density and bone quality in broilers hence it can be concluded that addition of Phytase at 0.30% NPP may prove beneficial for bone and overall performance in broilers.

Keywords: diaphysis diameter, phytase, rubosticity index, tibia

Procedia PDF Downloads 384
7754 Sources of Precipitation and Hydrograph Components of the Sutri Dhaka Glacier, Western Himalaya

Authors: Ajit Singh, Waliur Rahaman, Parmanand Sharma, Laluraj C. M., Lavkush Patel, Bhanu Pratap, Vinay Kumar Gaddam, Meloth Thamban

Abstract:

The Himalayan glaciers are the potential source of perennial water supply to Asia’s major river systems like the Ganga, Brahmaputra and the Indus. In order to improve our understanding about the source of precipitation and hydrograph components in the interior Himalayan glaciers, it is important to decipher the sources of moisture and their contribution to the glaciers in this river system. In doing so, we conducted an extensive pilot study in a Sutri Dhaka glacier, western Himalaya during 2014-15. To determine the moisture sources, rain, surface snow, ice, and stream meltwater samples were collected and analyzed for stable oxygen (δ¹⁸O) and hydrogen (δD) isotopes. A two-component hydrograph separation was performed for the glacier stream using these isotopes assuming the contribution of rain, groundwater and spring water contribution is negligible based on field studies and available literature. To validate the results obtained from hydrograph separation using above method, snow and ice melt ablation were measured using a network of bamboo stakes and snow pits. The δ¹⁸O and δD in rain samples range from -5.3% to -20.8% and -31.7% to -148.4% respectively. It is noteworthy to observe that the rain samples showed enriched values in the early season (July-August) and progressively get depleted at the end of the season (September). This could be due to the ‘amount effect’. Similarly, old snow samples have shown enriched isotopic values compared to fresh snow. This could because of the sublimation processes operating over the old surface snow. The δ¹⁸O and δD values in glacier ice samples range from -11.6% to -15.7% and -31.7% to -148.4%, whereas in a Sutri Dhaka meltwater stream, it ranges from -12.7% to -16.2% and -82.9% to -112.7% respectively. The mean deuterium excess (d-excess) value in all collected samples exceeds more than 16% which suggests the predominant moisture source of precipitation is from the Western Disturbances. Our detailed estimates of the hydrograph separation of Sutri Dhaka meltwater using isotope hydrograph separation and glaciological field methods agree within their uncertainty; stream meltwater budget is dominated by glaciers ice melt over snowmelt. The present study provides insights into the sources of moisture, controlling mechanism of the isotopic characteristics of Sutri Dhaka glacier water and helps in understanding the snow and ice melt components in Chandra basin, Western Himalaya.

Keywords: D-excess, hydrograph separation, Sutri Dhaka, stable water isotope, western Himalaya

Procedia PDF Downloads 142
7753 Isolation and Characterization of Indigenous Rhizosphere Bacteria Producing Gibberellin Acid from Local Soybeans in Three Different Areas of South Sulawesi

Authors: Asmiaty Sahur, Ambo Ala, Baharuddin Patanjengi, Elkawakib Syam'un

Abstract:

This study aimed to isolate and characterize the indigenous Rhizosphere bacteria producing Gibberellin Acid as plant growth isolated from local soybean of three different areas in South Sulawesi, Indonesia. Several soil samples of soybean plants were collected from the Rhizosphere of local soybeans in three different areas of South Sulawesi such as Soppeng, Bone and Takalar. There were 56 isolates of bacteria were isolated and grouped into gram-positive bacteria and gram negative bacteria .There are 35 isolates produce a thick slime or slimy when cultured on media Natrium Broth and the remaining of those produced spores. The results showed that of potential bacterial isolated produced Gibberellin Acid in high concentration. The best isolate of Rhizosphere bacteria for the production of Gibberellin Acid is with concentration 2%. There are 4 isolates that had higher concentration are AKB 19 (4.67 mg/ml) followed by RKS 17 (3.80 mg/ml), RKS 25 (3.70 mg / ml) and RKS 24 (3.29 mg/ml) respectively.

Keywords: rhizosphere, bacteria, gibberellin acid, soybeans

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7752 The Aspect of Urban Inequality after Urban Redevelopment Projects

Authors: Sungik Kang, Ja-Hoon Koo

Abstract:

Globally, urban environments have become unequal, and cities have been segmented by income class. It is predicted that urban inequality has arisen by urban redevelopment and reconstruction projects that improve the urban environment and innovate cities. This study aims to analyze the occurrence and characteristics of urban inequality by using the housing price and sale price and demonstrating the correlation with the urban redevelopment project. This study measures 14 years of urban inequality index for 25 autonomous districts in Seoul and analyzes the correlation between urban inequality with urban redevelopment projects. As a conclusion of this study, first, the urban inequality index of Seoul has been continuously rising since 2015. Trends from 2006 to 2019 have been in U-curved shape in between 2015. In 2019, Seoul's urban inequality index was 0.420, a level similar to that of the 2007 financial crisis. Second, the correlation between urban redevelopment and urban inequality was not statistically significant. Therefore, we judged that urban redevelopment's scale or project structure has nothing with urban inequality. Third, while district designation of urban reconstruction temporarily alleviates urban inequality, the completion of the project increases urban inequality. When designating a district, urban inequality is likely to decrease due to decreased outdated housing transactions. However, the correlation with urban inequality increases as expensive houses has been placed after project completion.

Keywords: urban inequality, urban redevelopment projects, urban reconstruction projects, housing price inequality, panel analysis

Procedia PDF Downloads 195
7751 Comparing Groundwater Fluoride Level with WHO Guidelines and Classifying At-Risk Age Groups; Based on Health Risk Assessment

Authors: Samaneh Abolli, Kamyar Yaghmaeian, Ali Arab Aradani, Mahmood Alimohammadi

Abstract:

The main route of fluoride uptake is drinking water. Fluoride absorption in the acceptable range (0.5-1.5 mg L-¹) is suitable for the body, but it's too much consumption can have irreversible health effects. To compare fluoride concentration with the WHO guidelines, 112 water samples were taken from groundwater aquifers in 22 villages of Garmsar County, the central part of Iran, during 2018 to 2019.Fluoride concentration was measured by the SPANDS method, and its non-carcinogenic impacts were calculated using EDI and HQ. The statistical population was divided into four categories of infant, children, teenagers, and adults. Linear regression and Spearman rank correlation coefficient tests were used to investigate the relationships between the well's depth and fluoride concentration in the water samples. The annual mean concentrations of fluoride in 2018 and2019 were 0.75 and 0.64 mg -¹ and, the fluoride mean concentration in the samples classifying the cold and hot seasons of the studied years was 0.709 and 0.689 mg L-¹, respectively. The amount of fluoride in 27% of the samples in both years was less than the acceptable minimum (0.5 mg L-¹). Also, 11% of the samples in2018 (6 samples) had fluoride levels higher than 1.5 mg L-¹. The HQ showed that the children were vulnerable; teenagers and adults were in the next ranks, respectively. Statistical tests showed a reverse and significant correlation (R2 = 0.02, < 0.0001) between well depth and fluoride content. The border between the usefulness/harmfulness of fluoride is very narrow and requires extensive studies.

Keywords: fluoride, groundwater, health risk assessment, hazard quotient, Garmsar

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7750 TiO₂ Nanotube Array Based Selective Vapor Sensors for Breath Analysis

Authors: Arnab Hazra

Abstract:

Breath analysis is a quick, noninvasive and inexpensive technique for disease diagnosis can be used on people of all ages without any risk. Only a limited number of volatile organic compounds (VOCs) can be associated with the occurrence of specific diseases. These VOCs can be considered as disease markers or breath markers. Selective detection with specific concentration of breath marker in exhaled human breath is required to detect a particular disease. For example, acetone (C₃H₆O), ethanol (C₂H₅OH), ethane (C₂H₆) etc. are the breath markers and abnormal concentrations of these VOCs in exhaled human breath indicates the diseases like diabetes mellitus, renal failure, breast cancer respectively. Nanomaterial-based vapor sensors are inexpensive, small and potential candidate for the detection of breath markers. In practical measurement, selectivity is the most crucial issue where trace detection of breath marker is needed to identify accurately in the presence of several interfering vapors and gases. Current article concerns a novel technique for selective and lower ppb level detection of breath markers at very low temperature based on TiO₂ nanotube array based vapor sensor devices. Highly ordered and oriented TiO₂ nanotube array was synthesized by electrochemical anodization of high purity tatinium (Ti) foil. 0.5 wt% NH₄F, ethylene glycol and 10 vol% H₂O was used as the electrolyte and anodization was carried out for 90 min with 40 V DC potential. Au/TiO₂ Nanotube/Ti, sandwich type sensor device was fabricated for the selective detection of VOCs in low concentration range. Initially, sensor was characterized where resistive and capacitive change of the sensor was recorded within the valid concentration range for individual breath markers (or organic vapors). Sensor resistance was decreased and sensor capacitance was increased with the increase of vapor concentration. Now, the ratio of resistive slope (mR) and capacitive slope (mC) provided a concentration independent constant term (M) for a particular vapor. For the detection of unknown vapor, ratio of resistive change and capacitive change at any concentration was same to the previously calculated constant term (M). After successful identification of the target vapor, concentration was calculated from the straight line behavior of resistance as a function of concentration. Current technique is suitable for the detection of particular vapor from a mixture of other interfering vapors.

Keywords: breath marker, vapor sensors, selective detection, TiO₂ nanotube array

Procedia PDF Downloads 148